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Title:
METHOD OF MAKING MAN MADE VITREOUS FIBRE PRODUCTS
Document Type and Number:
WIPO Patent Application WO/2021/197627
Kind Code:
A1
Abstract:
The invention relates to a method of making a bonded man-made vitreous fibre product wherein the man-made vitreous fibres are bonded together by supplying a liquid binder composition through a conduit, passing the binder composition through a filter and then applying the binder composition to the fibres, whilst applying silane to the fibres separately from the binder composition. The binder is an aqueous composition which comprises - a component (i) in form of one or more oxidized lignins; - a component (ii) in form of one or more cross-linkers; - a component (iii) in form of one or more plasticizers.

Inventors:
JOHANSSON DORTE BARTNIK (DK)
NIKOLIC MIROSLAV (DK)
FREDERIKSEN SØREN (DK)
Application Number:
PCT/EP2020/059649
Publication Date:
October 07, 2021
Filing Date:
April 03, 2020
Export Citation:
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Assignee:
ROCKWOOL INT AS (DK)
International Classes:
D04H1/4218; D04H1/587; D04H1/64
Domestic Patent References:
WO2018206132A12018-11-15
WO2012172262A12012-12-20
WO1999036368A11999-07-22
WO2001005725A12001-01-25
WO2001096460A22001-12-20
WO2002006178A12002-01-24
WO2004007615A12004-01-22
WO2006061249A12006-06-15
WO2008023032A12008-02-28
WO1996038391A11996-12-05
WO2002032821A22002-04-25
WO2015055758A12015-04-23
Foreign References:
US3285801A1966-11-15
EP0583086A11994-02-16
EP0990727A12000-04-05
EP1741726A12007-01-10
US5318990A1994-06-07
US20070173588A12007-07-26
US6818699B22004-11-16
US6706853B12004-03-16
US20030042344A12003-03-06
Other References:
CHEMICAL ABSTRACTS, Columbus, Ohio, US; abstract no. 9002-89-5
Attorney, Agent or Firm:
GILL JENNINGS & EVERY LLP (GB)
Download PDF:
Claims:
CLAIMS

1. A method of making a bonded man-made vitreous fibre product, the method comprising providing a mineral melt; providing a fiberizing apparatus supplying mineral melt to the fiberizing apparatus and forming the melt into a cloud of fibres entrained in air; supplying liquid binder composition through a conduit and passing the binder composition through a filter and then applying the binder composition to the fibres; applying silane to the fibres separately from the binder composition; collecting the fibres as a web; consolidating the web of fibres; and curing the binder to form a bonded product, and wherein the binder composition is an aqueous binder composition for mineral fibers comprising: a component (i) in form of one or more oxidized lignins; a component (ii) in form of one or more cross-linkers; a component (iii) in form of one or more plasticizers.

2. A method according to claim 1 wherein the binder composition is applied to the fibres whilst the fibres are entrained in air.

3. A method according to claim 1 or claim 2 wherein the fiberizing apparatus comprises a cascade of a plurality of fiberizing rotors, which each rotate about a substantially horizontal axis.

4. A method according to claim 1 or claim 2 additionally comprising applying cooling water to the fibres from the fiberizing apparatus and wherein silane is included in the cooling water. 5. A method according to any preceding claim in which the filter is a mesh having a size less than 250 μm.

6. A method according to any preceding claim in which the silane is an amino functional silane, an epoxysilane or a glycidylether functional silane.

7. The method according to any of the preceding claims, wherein component (i) is in form of one or more ammonia-oxidized lignins (AOL’s).

8. The method according to any of the preceding claims, wherein the component (ii) comprises one or more cross-linkers selected from β-hydroxyalkylamide- cross-linkers and/or oxazoline-cross-linkers.

9. The method according to any of the preceding claims, wherein the component (ii) comprises one or more cross-linkers selected from the group consisting of polyethylene imine, polyvinyl amine, fatty amines; and/or one more cross-linkers in form of fatty amides; and/or one or more cross-linkers selected from the group consisting of dimethoxyethanal, glycolaldehyde, glyoxalic acid; and/or one or more cross-linkers selected from polyester polyols, such as polycaprolactone; and/or - one or more cross-linkers selected from the group consisting of starch, modified starch, CMC; and/or one or more cross-linkers in form of aliphatic multifunctional carbodiimides; and/or one or more cross-linkers selected from melamine based cross- linkers, such as a hexakis(methylmethoxy)melamine (HMMM) based cross-linkers.

10. The method according to any of the preceding claims, wherein the aqueous binder composition comprises component (ii) in an amount of 1 to 40 wt.-%, such as 4 to 20 wt.-%, such as 6 to 12 wt.-%, based on the dry weight of component (i).

11. The method according to any of the preceding claims, wherein component (iii) comprises one or more plasticizers selected from the group consisting of polyethylene glycols, polyethylene glycol ethers, polyethers, hydrogenated sugars, phthalates and/or acids, such as adipic acid, vanillic acid, lactic acid and/or ferullic acid, acrylic polymers, polyvinyl alcohol, polyurethane dispersions, ethylene carbonate, propylene carbonate, lactones, lactams, lactides, acrylic based polymers with free carboxy groups and/or polyurethane dispersions with free carboxy groups.

12. The method according to any of the preceding claims, wherein component (iii) comprises

- one or more plasticizers selected from the group consisting of fatty alcohols, monohydroxy alcohols, such as pentanol, stearyl alcohol; and/or - one or more plasticizers selected from the group consisting of alkoxylates such as ethoxylates, such as butanol ethoxylates, such as butoxytriglycol; and/or

- one or more plasticizers in form of propylene glycols; and/or

- one or more plasticizers in form of glycol esters; and/or - one or more plasticizers selected from the group consisting of adipates, acetates, benzoates, cyclobenzoates, citrates, stearates, sorbates, sebacates, azelates, butyrates, valerates; and/or

- one or more plasticizers selected from the group consisting of phenol derivatives, such as alkyl or aryl substituted phenols; and/or - one or more plasticizers selected from the group consisting of silanols, siloxanes; and/or

- one or more plasticizers selected from the group consisting of sulfates such as alkyl sulfates, sulfonates such as alkyl aryl sulfonates such as alkyl and/or - sulfonates, phosphates such as tripolyphosphates; and/or one or more plasticizers in form of hydroxy acids; and/or one or more plasticizers selected from the group consisting of monomeric amides, such as acetamides, benzamide, fatty acid amides such as tall oil amides; and/or one or more plasticizers selected from the group consisting of quaternary ammonium compounds such as trimethylglycine, distearyldimethylammoniumchloride; and/or one or more plasticizers selected from the group consisting of vegetable oils such as castor oil, palm oil, linseed oil, tall oil, soybean oil; and/or one or more plasticizers selected from the group consisting of hydrogenated oils, acetylated oils; and/or one or more plasticizers selected from acid methyl esters; and/or one or more plasticizers selected from the group consisting of alkyl polyglucosides, gluconamides, aminoglucoseamides, sucrose esters, sorbitan esters; and/or one or more plasticizers selected from the group consisting of polyethylene glycols, polyethylene glycol ethers.

13. The method according to any of the preceding claims, wherein the component (iii) is present in the aqueous binder composition in an amount of 0.5 to 50, preferably 2.5 to 25, more preferably 3 to 15 wt.-%, based on the dry weight of component (i).

14. The method according to any of the preceding claims, wherein the aqueous binder composition comprises a further component (iv) in form of one or more coupling agents, such as organofunctional silanes.

15. The method according to any of the preceding claims, wherein the aqueous binder composition further comprises a component (v) in form of one or more components selected from the group of ammonia, amines or any salts thereof.

16. The method according to any of the preceding claims, wherein the aqueous binder composition comprises a further component in form of urea, in particular in an amount 5 to 40 wt.-%, such as 10 to 30 wt.-%, such as 15 to 25 wt.-%, based on the dry weight of component (i).

17. The method according to any of the preceding claims, wherein the aqueous binder composition consists essentially of - a component (i) in form of one or more oxidized lignins; a component (ii) in form of one or more cross-linkers; a component (iii) in form of one or more plasticizers; a component (iv) in form of one or more coupling agents, such as organofunctional silanes; - optionally a component in form of one or more compounds selected from the group of ammonia, amines or any salts thereof; optionally a component in form of urea; optionally a component in form of a more reactive or nonreactive silicones; - optionally a hydrocarbon oil; optionally one or more surface active agents; water.

Description:
METHOD OF MAKING MAN MADE VITREOUS FIBRE PRODUCTS

The invention relates to methods of making bonded man-made vitreous fibre (MMVF) products containing silane.

It is well-known to make bonded MMVF products by fiberizing a mineral melt to form a cloud of fibres entrained in air, applying binder to the fibres, collecting the fibres as a web, consolidating the web and then curing the binder. The binder is generally supplied as a composition in liquid form via a conduit to spray nozzles and is passed through a filter before application to the fibres. The filtration is intended to remove particulate material that would damage the fiberizing apparatus or otherwise interfere with the process.

It is also well known to apply a silane compound to the fibres as they are being formed. Silane compounds act as coupling agents to enhance bonding of the binder to the fibres. Conventionally, the silane is included as a blend with the binder composition that is supplied via the conduit, passed through the filter and sprayed on to the fibres.

It is common to use phenol-formaldehyde resin as binder for such products. Phenol- formaldehyde binder gives good results and is commonly used in commercial practice.

Phenol-formaldehyde resins can be economically produced and can be extended with urea prior to use as a binder. However, the existing and proposed legislation directed to the lowering or elimination of formaldehyde emissions have led to the development of formaldehyde-free binders such as, for instance, the binder compositions based on polycarboxy polymers and polyols or polyamines, such as disclosed in EP-A-583086, EP-A-990727, EP-A-1741726, US-A-5, 318,990 and US-A-2007/0173588.

Another group of non-phenol-formaldehyde binders are the addition/-elimination reaction products of aliphatic and/or aromatic anhydrides with alkanolamines, e.g., as disclosed in WO 99/36368, WO 01/05725, WO 01/96460, WO 02/06178, WO 2004/007615 and WO 2006/061249. These binder compositions are water soluble and exhibit excellent binding properties in terms of curing speed and curing density. WO 2008/023032 discloses urea-modified binders of that type which provide mineral wool products having reduced moisture take-up.

Some of the starting materials used in the production of these binders are rather expensive chemicals, so there is an ongoing need to provide formaldehyde-free binders which are economically produced.

A further effect in connection with previously known aqueous binder compositions for mineral fibres is that at least the majority of the starting materials used for the productions of these binders stem from fossil fuels. There is an ongoing trend of consumers to prefer products that are fully or at least partly produced from renewable materials and there is therefore a need to provide binders for mineral wool which are, at least partly, produced from renewable materials.

A further effect in connection with previously known aqueous binder compositions for mineral fibres is that they involve components which are corrosive and/or harmful. This requires protective measures for the machinery involved in the production of mineral wool products to prevent corrosion and also requires safety measures for the persons handling this machinery. This leads to increased costs and health issues and there is therefore a need to provide binder compositions with a reduced content of corrosive and/or harmful materials.

In the meantime, a number of binders for mineral fibres have been provided, which are to a large extent based on renewable starting materials. In many cases these binders based to a large extent on renewable resources are also formaldehyde-free.

However, many of these binders are still comparatively expensive because they are based on comparatively expensive basic materials and so their use as binders for MMVF products would be uneconomical.

Accordingly, it is an object of the present invention to provide a binder composition for MMVF which uses renewable materials as starting materials, reduces or eliminates corrosive and/or harmful materials, and is comparatively inexpensive to produce.

We have provided a novel binder composition which addresses these problems. The novel binder is an aqueous composition which comprises

- a component (i) in form of one or more oxidized lignins;

- a component (ii) in form of one or more cross-linkers;

- a component (iii) in form of one or more plasticizers.

However, we have found that when the conventional production process is used, involving supplying binder composition as a blend with silane through a conduit and passing it through a filter before application to the fibres, the filters become blocked in a matter of minutes. This is highly inconvenient for operation of the process, in which it is usual to change filters after a number of hours, ideally only once per day.

Therefore, the invention seeks to provide a means of providing a product having a binder with the advantages of the above-mentioned novel binder.

In particular by the use of this binder it is possible to produce a mineral wool product comprising mineral fibres bound by a binder resulting from the curing of a binder composition, whereby the binder composition can be produced from inexpensive renewable materials to a large degree, does not contain, or contains only to a minor degree, any corrosive and/or harmful agents.

However, the invention seeks to do this whilst reducing the problem of filter blockage.

According to the invention we provide a method of making a bonded man-made vitreous fibre product, the method comprising providing a mineral melt; providing a fiberizing apparatus supplying mineral melt to the fiberizing apparatus and forming the melt into a cloud of fibres entrained in air; supplying liquid binder composition through a conduit and passing the binder composition through a filter and then applying the binder composition to the fibres; applying silane to the fibres separately from the binder composition; collecting the fibres as a web; consolidating the web of fibres; and curing the binder to form a bonded product, and wherein the binder is an aqueous composition which comprises

- a component (i) in form of one or more oxidized lignins;

- a component (ii) in form of one or more cross-linkers;

- a component (iii) in form of one or more plasticizers.

We find that in the case of the particular defined binder used in the invention, application of the silane separately from the binder composition significantly reduces filter blockage. It is then possible to retain a single filter for a matter of hours rather than minutes, as is observed when silane is included in the binder composition.

The method of the invention involves provision of a mineral melt. A mineral melt is provided in a conventional manner by providing mineral materials and melting them in a furnace. This furnace can be any of the types of furnace known for production of mineral melts for MMVF, for instance a shaft furnace such as a cupola furnace, a tank furnace, or a cyclone furnace.

The fiberization can be by a spinning cup process in which melt is centrifugally extruded through orifices in the walls of a rotating cup (spinning cup, also known as internal centrifugation). Alternatively the fiberization can be by centrifugal fiberization by projecting the melt onto and spinning off the outer surface of one fiberizing rotor, or off a cascade of a plurality of fiberizing rotors, which rotate about a substantially horizontal axis (cascade spinner). In particular in a preferred method the fiberizing apparatus comprises: a set of at least three rotors each mounted for rotation about a different substantially horizontal axis; wherein each rotor has a driving means; and the method comprises pouring the melt on to the periphery of the first rotor; wherein melt poured on to the periphery of the first rotor in the set is thrown on to the periphery of the subsequent rotors in turn and fibres are thrown off the rotors.

The fiberization of the fibres is usually promoted by air blasts around the or each rotor and the fibres are entrained by air and carried to a collector. Binder is sprayed on to the fibres, preferably before collection. Methods of this general type are well known and are particularly suitable for rock, stone or slag fibres. WO 96/38391 describes a preferred method of apparatus in detail and refers to extensive literature on fiberization processes which can also be used for making the fibres. Other suitable apparatus and processes are described in WO02/32821 and WO2015/055758.

In the case of a cascade spinner, it is conventional to have an air slot mounted concentrically with the peripheral surface of a spinner wheel and serving to supply air to the peripheral surface. The air stream preferably has both an axial and tangential speed component relative to the spinner wheel. This air stream assists in forming the formed fibres into a cloud entrained in air and carrying it away from the spinner.

In the case of other types of fiberizing apparatus it is also conventional to provide an air stream to the apparatus so as to carry the fibres away from the surface at which they are formed as a cloud entrained in air.

The fibres are collected as a web on a conveyor and carried away from the fiberizing apparatus. The web of fibres is then consolidated, which can involve cross-lapping and/or longitudinal compression and/or vertical compression and/or winding around a mandrel to produce a cylindrical product for pipe insulation. Other consolidation processes may also be performed.

After consolidation the consolidated web of fibres is passed into a curing device to cure the binder.

In one embodiment, the curing is carried out at temperatures from 100 to 300°C, such as 170 to 270°C, such as 180 to 250°C, such as 190 to 230°C.

In a preferred embodiment, the curing takes place in a conventional curing oven for mineral wool production, preferably operating at a temperature of from 150 to 300°C, such as 170 to 270°C, such as 180 to 250°C, such as 190 to 230°C.

In one embodiment, the curing takes place for a time of 30 seconds to 20 minutes, such as 1 to 15 minutes, such as 2 to 10 minutes.

In a typical embodiment, curing takes place at a temperature of 150 to 250 °C for a time of 30 seconds to 20 minutes.

The curing process may commence immediately after application of the binder to the fibres. The curing is defined as a process whereby the binder composition undergoes a physical and/or chemical reaction which in case of a chemical reaction usually increases the molecular weight of the compounds in the binder composition and thereby increases the viscosity of the binder composition, usually until the binder composition reaches a solid state. The cured binder composition binds the fibres to form a structurally coherent matrix of fibres.

In a one embodiment, the curing of the binder in contact with the mineral fibres takes place in a heat press.

The curing of a binder in contact with the mineral fibres in a heat press has the particular advantage that it enables the production of high-density products. In one embodiment the curing process comprises drying by pressure. The pressure may be applied by blowing air or gas through/over the mixture of mineral fibres and binder.

According to the invention the binder is applied in conventional manner.

The binder composition is applied to the fibres preferably when they are a cloud entrained in air. Alternatively it can be applied after collection on the conveyor but this is less preferred.

Most commonly, binder composition is supplied to a set of spray nozzles which are arranged around the spinner wheels of the fiberizing apparatus. Alternatively it can be supplied as part of the air stream that is provided to the apparatus to carry the fibres away from the fiberizing apparatus as a cloud.

Preferably spray nozzles for the binder composition are mounted in such a manner that the binder-composition-containing air streams generated by the nozzles flow parallel with the air streams moving along the circumferential surface of the spinner wheels.

The binder composition, alternatively or additionally, can be supplied via a spray wheel mounted on the front side of at least one spinner wheel in a cascade spinner.

The binder composition is supplied to the spray nozzles or spray wheel or into the air stream via an appropriate conduit and is passed through a filter prior to being applied to the fibres. Various forms of filter are known and can be used in the invention. For instance the filter could be a wire mesh filter, a glass fibre filter or a bag filter. A preferred option is a cartridge filter. For instance cartridge filters are supplied by Heco and their PWL and PW cartridge filters can be used.

Whichever type of filter is used, the mesh size is usually less than 250 microns, for instance around 200 microns. It is filters of this mesh size that tend to lead to problems with blockage, although the mesh size must be small enough that the filter is effective. Mesh size is generally at least 20 microns, preferably at least 100 microns, more preferably at least 150 microns, more preferably at least 180 microns. Application of the binder composition through such a filter without inclusion of silane in the binder composition has the advantage that blockage of the filter is greatly reduced. In the method of the invention is it possible to change the filter less than once per hour, more preferably less than once every 4 hours, in particular less than once every 8 hours.

According to the invention the silane is applied separately from the binder composition and is not supplied through the filter for the binder composition.

The silane can be supplied through separate spray nozzles or in the air stream which is supplied along the periphery of the fiberizing wheel, in similar manner to the binder. However, preferably in the method a stream of cooling water is supplied to the cloud of fibres entrained in air and the silane is supplied in the cooling water.

In the case of a cascade spinner, having rotors with a solid periphery, which rotate about a horizontal axis, it is known to supply cooling water from within the rotors and expel the cooling water from the front face of the rotor so that it comes into contact with the fibres as they are forming. It is preferred to include the silane in this cooling water.

The silane is generally provided in aqueous solution. Preferred silanes are amino functional silanes or glycidyl ether functional silanes. Particularly preferred is gamma- aminopropyltriethoxysilane.

The amount of silane is generally in the range 0.1 to 2 % by weight silane compound based on solid binder content also being applied to the fibres.

The MMVF products generally have a loss on ignition (LOI) within the range of 0.3 to 18.0 %, preferably 0.5 to 8.0 %. The LOI is taken as the binder content, in conventional manner. Binder will normally include minor amounts of oil and other organic binder additives in addition to the main bonding components.

The bonded MMVF product emerging from the curing oven may be cut to a desired format e.g., in the form of a batt. Thus, the mineral fibre products produced, for instance, have the form of woven and nonwoven fabrics, mats, batts, slabs, sheets, plates, strips, rolls, granulates and other shaped articles.

The MMVF product may be used as, for example, thermal or acoustical insulation materials, vibration damping, construction materials, facade insulation, reinforcing materials for roofing or flooring applications, as filter stock and in other applications.

It is also possible to produce composite materials by combining the bonded MMVF product with suitable composite layers or laminate layers such as, e.g., metal, glass surfacing mats and other woven or non-woven materials.

The man-made vitreous fibres (MMVF) can have any suitable oxide composition. The fibres can be glass fibres, ceramic fibres, basalt fibres, slag fibres or rock or stone fibres. The fibres are preferably of the types generally known as rock, stone or slag fibres, most preferably stone fibres.

Stone fibres commonly comprise the following oxides, in percent by weight:

Si0 2 : 30 to 51 CaO: 8 to 30 MgO: 2 to 25

FeO (including Fe 2 0 3 ): 2 to 15 Na 2 0+K 2 0: not more than 10 CaO+MgO: 10 to 30

In preferred embodiments the MMVF have the following levels of elements, calculated as oxides in wt%:

Si0 2 : at least 30, 32, 35 or 37; not more than 51 , 48, 45 or 43

Al 2 0 3 : at least 12, 16 or 17; not more than 30, 27 or 25 CaO: at least 8 or 10; not more than 30, 25 or 20

MgO: at least 2 or 5; not more than 25, 20 or 15

FeO (including Fe203): at least 4 or 5; not more than 15, 12 or 10

FeO+MgO: at least 10, 12 or 15; not more than 30, 25 or 20

Na 2 0+K 2 O: zero or at least 1; not more than 10

CaO+MgO: at least 10 or 15; not more than 30 or 25

Ti02: zero or at least 1 ; not more than 6, 4 or 2

Ti0 2 +FeO: at least 4 or 6; not more than 18 or 12

B 2 Ob: zero or at least 1 ; not more than 5 or 3

P 2 Os: zero or at least 1 ; not more than 8 or 5

Others: zero or at least 1 ; not more than 8 or 5

The MMVF made by the method of the invention preferably have the composition in wt%:

SiO 2 35 to 50 Al 2 O 3 12 to 30

TiO 2 up to 2 Fe 2 O 3 3 to 12 CaO 5 to 30 MgO up to 15 Na 2 O 0 to 15 K2O 0 to 15

P2O5 up to 3

MnO up to 3

B2O3 up to 3

Another preferred composition for the MMVF is as follows in wt%:

SiO 2 39-55% preferably 39-52%

AI 2 O 3 16-27% preferably 16-26%

CaO 6-20% preferably 8-18%

MgO 1-5% preferably 1-4.9%

Na 2 O 0-15% preferably 2-12%

K 2 O 0-15% preferably 2-12%

R2O (Na 2 0 + K 2 0) 10-14.7% preferably 10-13.5%

P2O5 0-3% preferably 0-2%

Fe 2 O 3 (iron total) 3-15% preferably 3.2-8%

B2O3 0-2% preferably 0-1 %

TiO 2 0-2% preferably 0.4-1%

Others 0-2.0%

Glass fibres commonly comprise the following oxides, in percent by weight:

SiO 2 : 50 to 70 AI2O3: 10 to 30 CaO: not more than 27 MgO: not more than 12

Glass fibres can also contain the following oxides, in percent by weight:

Na 2 O+K 2 O: 8 to 18, in particular Na 2 O+K 2 O greater than CaO+MgO B 2 O 3 : 3 to 12

Some glass fibre compositions can contain Al 2 O 3 : less than 2% .

The MMVF generally have average fibre diameter in the range 3 to 8 microns.

The binder composition used according to the present invention is in the form of an aqueous composition. Preferred features are discussed below.

The aqueous binder comprises

- a component (i) in form of one or more oxidized lignins;

- a component (ii) in form of one or more cross-linkers;

- a component (iii) in form of one or more plasticizers.

In a preferred embodiment, the binders used according to the present invention are formaldehyde free.

For the purpose of the present application, the term "formaldehyde free" is defined to characterize a mineral wool product where the emission is below 5 μg/m 2 /h of formaldehyde from the mineral wool product, preferably below 3 μg/m 2 /h. Preferably, the test is carried out in accordance with ISO 16000 for testing aldehyde emissions.

Component (i) Component (i) is in form of one or more oxidized lignins.

Lignin, cellulose and hemicellulose are the three main organic compounds in a plant cell wall. Lignin can be thought of as the glue, that holds the cellulose fibres together. Lignin contains both hydrophilic and hydrophobic groups. It is the second most abundant natural polymer in the world, second only to cellulose, and is estimated to represent as much as 20-30% of the total carbon contained in the biomass, which is more than 1 billion tons globally.

Fig. 1 shows a section from a possible lignin structure.

There are at least four groups of technical lignins available in the market. These four groups are shown in Fig. 3. A possible fifth group, Biorefinery lignin, is a bit different as it is not described by the extraction process, but instead by the process origin, e.g. biorefining and it can thus be similar or different to any of the other groups mentioned. Each group is different from each other and each is suitable for different applications. Lignin is a complex, heterogenous material composed of up to three different phenyl propane monomers, depending on the source. Softwood lignins are made mostly with units of coniferyl alcohol, see fig. 2 and as a result, they are more homogeneous than hardwood lignins, which has a higher content of syringyl alcohol, see fig. 2. The appearance and consistency of lignin are quite variable and highly contingent on process.

A summary of the properties of these technical lignins is shown in Fig. 4.

Lignosulfonate from the sulfite pulping process remains the largest commercial available source of lignin, with capacity of 1.4 million tonnes. But taking these aside, the kraft process is currently the most used pulping process and is gradually replacing the sulfite process. An estimated 78 million tonnes per year of lignin are globally generated by kraft pulp production but most of it is burned for steam and energy. Current capacity for kraft recovery is estimated at 160,000 tonnes, but sources indicate that current recovery is only about 75,000 tonnes. Kraft lignin is developed from black liquour, the spent liquor from the sulfate or kraft process. At the moment, 3 well-known processes are used to produce the kraft lignin: LignoBoost, LignoForce and SLRP. These 3 processes are similar in that they involve the addition of CO2 to reduce the pH to 9-10, followed by acidification to reduce pH further to approximately 2. The final step involves some combination of washing, leaching and filtration to remove ash and other contaminants. The three processes are in various stages of commercialization globally.

The kraft process introduces thiol groups, stilbene while some carbohydrates remain. Sodium sulphate is also present as an impurity due to precipitation of lignin from liquor with sulphuric acid but can potentially be avoided by altering the way lignin is isolated. The kraft process leads to high amount of phenolic hydroxyl groups and this lignin is soluble in water when these groups are ionized (above pH~10).

Commercial kraft lignin is generally higher in purity than lignosulfonates. The molecular weight are 1000-3000 g/mol.s

Soda lignin originates from sodium hydroxide pulping processes, which are mainly used for wheat straw, bagasse and flax. Soda lignin properties are similar to kraft lignins one in terms of solubility and T g . This process does not utilize sulphur and there is no covalently bound sulphur. The ash level is very low. Soda lignin has a low solubility in neutral and acid media but is completely soluble at pH 12 and higher.

The lignosulfonate process introduces large amount of sulphonate groups making the lignin soluble in water but also in acidic water solutions. Lignosulfonates has up to 8% sulfur as sulphonate, whereas kraft lignin has 1-2% sulfur, mostly bonded to the lignin. The molecular weight of lignosulfonate is 15.000-50.000 g/mol. This lignin contains more leftover carbohydrates compared to other types and has a higher average molecular weight. The typical hydrophobic core of lignin together with large number of ionized sulphonate groups make this lignin attractive as a surfactant and it often finds application in dispersing cement etc.

A further group of lignins becoming available is lignins resulting from biorefining processes in which the carbohydrates are separated from the lignin by chemical or biochemical processes to produce a carbohydrate rich fraction. This remaining lignin is referred to as biorefinery lignin. Biorefineries focus on producing energy, and producing substitutes for products obtained from fossil fuels and petrochemicals as well as lignin. The lignin from this process is in general considered a low value product or even a waste product mainly used for thermal combustion or used as low grade fodder or otherwise disposed of.

Organosolv lignin availability is still considered on the pilot scale. The process involves extraction of lignin by using water together with various organic solvents (most often ethanol) and some organic acids. An advantage of this process is the higher purity of the obtained lignin but at a much higher cost compared to other technical lignins and with the solubility in organic solvents and not in water.

Previous attempts to use lignin as a basic compound for binder compositions for mineral fibres failed because it proved difficult to find suitable cross-linkers which would achieve desirable mechanical properties of the cured mineral wool product and at the same time avoid harmful and/or corrosive components. Presently lignin is used to replace oil derived chemicals, such as phenol in phenolic resins in binder applications or in bitumen. It is also used as cement and concrete additives and in some aspects as dispersants.

The cross-linking of a polymer in general should provide improved properties like mechanical, chemical and thermal resistance etc. Lignin is especially abundant in phenolic and aliphatic hydroxyl groups that can be reacted leading to cross-linked structure of lignin. Different lignins will also have other functional groups available that can potentially be used. The existence of these other groups is largely dependent on the way lignin was separated from cellulose and hemicellulose (thiols in kraft lignin, sulfonates in lignosulfonate etc.) depending on the source.

It has been found that by using oxidized lignins, binder compositions for mineral fibres can be prepared which allow excellent properties of the mineral fibre product produced.

In one embodiment, the component (i) is in form of one or more oxidized kraft lignins.

In one embodiment, the component (i) is in form of one or more oxidized soda lignins. In one embodiment, the component (i) is in form of one or more ammonia-oxidized lignins. For the purpose of the present invention, the term “ammonia-oxidized lignins” is to be understood as a lignin that has been oxidized by an oxidation agent in the presence of ammonia. The term “ammonia-oxidized lignin” is abbreviated asAOL.

In an alternative embodiment, the ammonia is partially or fully replaced by an alkali metal hydroxide, in particular sodium hydroxide and/or potassium hydroxide.

A typical oxidation agent used for preparing the oxidized lignins is hydrogen peroxide.

In one embodiment, the ammonia-oxidized lignin comprises one or more of the compounds selected from the group of ammonia, amines, hydroxides or any salts thereof.

In one embodiment, the component (i) is having a carboxylic acid group content of 0.05 to 10 mmol/g, such as 0.1 to 5 mmol/g, such as 0.20 to 1.5 mmol/g, such as 0.40 to 1.2 mmol/g, such as 0.45 to 1.0 mmol/g, based on the dry weight of component (i).

In one embodiment, the component (i) is having an average carboxylic acid group content of more than 1.5 groups per macromolecule of component (i), such as more than 2 groups, such as more than 2.5 groups.

It is believed that the carboxylic acid group content of the oxidized lignins plays an important role in the surprising advantages of the aqueous binder compositions for mineral fibres according to the present invention. In particular, it is believed that the carboxylic acid group of the oxidized lignins improve the cross-linking properties and therefore allow better mechanical properties of the cured mineral fibre products.

Component (ii)

Component (ii) is in form of one or more cross-linkers.

In one embodiment, the component (ii) comprises in one embodiment one or more cross-linkers selected from b-hydroxyalkylamide-cross-linkers and/or oxazoline-cross- linkers. b-hydroxyalkylamide-cross-linkers is a curing agent for the acid-functional macromolecules. It provides a hard, durable, corrosion resistant and solvent resistant cross-linked polymer network. It is believed the b-hydroxyalkylamide cross-linkers cure through esterification reaction to form multiple ester linkages. The hydroxy functionality of the b-hydroxyalkylamide-cross-linkers should be an average of at least 2, preferably greater than 2 and more preferably 2-4 in order to obtain optimum curing response.

Oxazoline group containing cross-linkers are polymers containing one of more oxazoline groups in each molecule and generally, oxazoline containing crosslinkers can easily be obtained by polymerizing an oxazoline derivative. The patent US6818699 B2 provides a disclosure for such a process.

In one embodiment, the component (ii) is an epoxidised oil based on fatty acid triglyceride.

It is noted that epoxidised oils based on fatty acid triglycerides are not considered hazardous and therefore the use of these compounds in the binder compositions according to the present invention do not render these compositions unsafe to handle.

In one embodiment, the component (ii) is a molecule having 3 or more epoxy groups.

In one embodiment, the component (ii) is one or more flexible oligomer or polymer, such as a low Tg acrylic based polymer, such as a low Tg vinyl based polymer, such as low Tg polyether, which contains reactive functional groups such as carbodiimide groups, such as anhydride groups, such as oxazoline groups, such as amino groups, such as epoxy groups.

In one embodiment, component (ii) is selected from the group consisting of cross linkers taking part in a curing reaction, such as hydroxyalkylamide, alkanolamine, a reaction product of an alkanolamine and a polycarboxylic acid. The reaction product of an alkanolamine and a polycarboxylic acid can be found in US6706853B1.

Without wanting to be bound by any particular theory, the present inventors believe it is believed that the very advantageous properties of the aqueous binder compositions according to the present invention are due to the interaction of the oxidized lignins used as component (i) and the cross-linkers mentioned above. It is believed that the presence of carboxylic acid groups in the oxidized lignins enable the very effective cross-linking of the oxidized lignins.

In one embodiment, the component (ii) is one or more cross-linkers selected from the group consisting of multifunctional organic amines such as an alkanolamine, diamines, such as hexamethyldiamine, triamines.

In one embodiment, the component (ii) is one or more cross-linkers selected from the group consisting of polyethylene imine, polyvinyl amine, fatty amines.

In one embodiment, the component (ii) is one or more fatty amides.

In one embodiment, the component (ii) is one or more cross-linkers selected from the group consisting of dimethoxyethanal, glycolaldehyde, glyoxalic acid.

In one embodiment, the component (ii) is one or more cross-linkers selected from polyester polyols, such as polycaprolactone.

In one embodiment, the component (ii) is one or more cross-linkers selected from the group consisting of starch, modified starch, CMC.

In one embodiment, the component (ii) is one or more cross-linkers in form of aliphatic multifunctional carbodiimides.

In one embodiment, the component (ii) is one or more cross-linkers selected from melamine based cross-linkers, such as a hexakis(methylmethoxy)melamine (HMMM) based cross-linkers.

Examples of such compounds are Picassian XL 701 , 702, 725 (Stahl Polymers), such as ZOLDINE® XL-29SE (Angus Chemical Company), such as CX300 (DSM), such as Carbodilite V-02-L2 (Nisshinbo Chemical Inc.).

Component (ii) can also be any mixture of the above mentioned compounds. In one embodiment, the binder composition according to the present invention comprises component (ii) in an amount of 1 to 40 wt.-%, such as 4 to 20 wt.-%, such as 6 to 12 wt.-%, based on the dry weight of component (i).

Component (iii)

Component (iii) is in form of one or more plasticizers.

In one embodiment, component (iii) is in form of one or more plasticizers selected from the group consisting of polyols, such as carbohydrates, hydrogenated sugars, such as sorbitol, erythriol, glycerol, monoethylene glycol, polyethylene glycols, polyethylene glycol ethers, polyethers, phthalates and/or acids, such as adipic acid, vanillic acid, lactic acid and/or ferullic acid, acrylic polymers, polyvinyl alcohol, polyurethane dispersions, ethylene carbonate, propylene carbonate, lactones, lactams, lactides, acrylic based polymers with free carboxy groups and/or polyurethane dispersions with free carboxy groups, polyamides, amides such as carbamide/urea, or any mixtures thereof.

In one embodiment, component (iii) is in form of one or more plasticizers selected from the group consisting of carbonates, such as ethylene carbonate, propylene carbonate, lactones, lactams, lactides, compounds with a structure similar to lignin like vanillin, acetosyringone, solvents used as coalescing agents like alcohol ethers, polyvinyl alcohol.

In one embodiment, component (iii) is in form of one or more non-reactive plasticizer selected from the group consisting of polyethylene glycols, polyethylene glycol ethers, polyethers, hydrogenated sugars, phthalates and/or other esters, solvents used as coalescing agents like alcohol ethers, acrylic polymers, polyvinyl alcohol.

In one embodiment, component (iii) is one or more reactive plasticizers selected from the group consisting of carbonates, such as ethylene carbonate, propylene carbonate, lactones, lactams, lactides, di- or tricarboxylic acids, such as adipic acid, or lactic acid, and/or vanillic acid and/or ferullic acid, polyurethane dispersions, acrylic based polymers with free carboxy groups, compounds with a structure similar to lignin like vanillin, acetosyringone.

In one embodiment, component (iii) is in form of one or more plasticizers selected from the group consisting of fatty alcohols, monohydroxy alcohols such as pentanol, stearyl alcohol.

In one embodiment, component (iii) comprises one or more plasticizers selected from the group consisting of polyethylene glycols, polyethylene glycol ethers.

Another particular surprising aspect of the present invention is that the use of plasticizers having a boiling point of more than 100 °C, in particular 140 to 250 °C, strongly improves the mechanical properties of the mineral fibre products according to the present invention although, in view of their boiling point, it is likely that these plasticizers will at least in part evaporate during the curing of the aqueous binders in contact with the mineral fibres.

In one embodiment, component (iii) comprises one or more plasticizers having a boiling point of more than 100 °C, such as 110 to 280 °C, more preferred 120 to 260 °C, more preferred 140 to 250 °C.

It is believed that the effectiveness of these plasticizers in the aqueous binder composition according to the present invention is associated with the effect of increasing the mobility of the oxidized lignins during the curing process. It is believed that the increased mobility of the lignins or oxidized lignins during the curing process facilitates the effective cross-linking.

In one embodiment, component (iii) comprises one or more polyethylene glycols having an average molecular weight of 150 to 50000 g/mol, in particular 150 to 4000 g/mol, more particular 150 to 1000 g/mol, preferably 150 to 500 g/mol, more preferably 200 to 400 g/mol.

In one embodiment, component (iii) comprises one or more polyethylene glycols having an average molecular weight of 4000 to 25000 g/mol, in particular 4000 to 15000 g/mol, more particular 8000 to 12000 g/mol. In one embodiment component (iii) is capable of forming covalent bonds with component (i) and/or component (ii) during the curing process. Such a component would not evaporate and remain as part of the composition but will be effectively altered to not introduce unwanted side effects e.g. water absorption in the cured product. Non-limiting examples of such a component are caprolactone and acrylic based polymers with free carboxyl groups.

In one embodiment, component (iii) is selected from the group consisting of fatty alcohols, monohydroxy alcohols, such as pentanol, stearyl alcohol.

In one embodiment, component (iii) is selected from one or more plasticizers selected from the group consisting of alkoxylates such as ethoxylates such as butanol ethoxylates, such as butoxytriglycol.

In one embodiment, component (iii) is selected from one or more propylene glycols.

In one embodiment, component (iii) is selected from one or more glycol esters.

In one embodiment, component (iii) is selected from one or more plasticizers selected from the group consisting of adipates, acetates, benzoates, cyclobenzoates, citrates, stearates, sorbates, sebacates, azelates, butyrates, valerates.

In one embodiment, component (iii) is selected from one or more plasticizers selected from the group consisting of phenol derivatives such as alkyl or aryl substituted phenols.

In one embodiment, component (iii) is selected from one or more plasticizers selected from the group consisting of silanols, siloxanes.

In one embodiment, component (iii) is selected from one or more plasticizers selected from the group consisting of sulfates such as alkyl sulfates, sulfonates such as alkyl aryl sulfonates such as alkyl sulfonates, phosphates such as tripolyphosphates; such as tributylphosphates.

In one embodiment, component (iii) is selected from one or more hydroxy acids. In one embodiment, component (iii) is selected from one or more plasticizers selected from the group consisting of monomeric amides such as acetamides, benzamide, fatty acid amides such as tall oil amides.

In one embodiment, component (iii) is selected from one or more plasticizers selected from the group consisting of quaternary ammonium compounds such as trimethylglycine, distearyldimethylammoniumchloride.

In one embodiment, component (iii) is selected from one or more plasticizers selected from the group consisting of vegetable oils such as castor oil, palm oil, linseed oil, tall oil, soybean oil.

In one embodiment, component (iii) is selected from one or more plasticizers selected from the group consisting of hydrogenated oils, acetylated oils.

In one embodiment, component (iii) is selected from one or more fatty acid methyl esters.

In one embodiment, component (iii) is selected from one or more plasticizers selected from the group consisting of alkyl polyglucosides, gluconamides, aminoglucoseamides, sucrose esters, sorbitan esters.

It has surprisingly been found that the inclusion of plasticizers in the aqueous binder compositions according to the present invention strongly improves the mechanical properties of the mineral fibre products according to the present invention.

The term plasticizer refers to a substance that is added to a material in order to make the material softer, more flexible (by decreasing the glass-transition temperature Tg) and easier to process.

Component (iii) can also be any mixture of the above mentioned compounds.

In one embodiment, component (iii) is present in an amount of 0.5 to 50, preferably 2.5 to 25, more preferably 3 to 15 wt.-%, based on the dry weight of component (i).

Aqueous binder composition for mineral fibers comprising components (i) and (iia) In one embodiment the aqueous binder composition for mineral fibers comprises:

- a component (i) in form of one or more oxidized lignins;

- a component (iia) in form of one or more modifiers.

The present inventors have found that the excellent binder properties can also be achieved by a two-component system which comprises component (i) in form of one or more oxidized lignins and a component (iia) in form of one or more modifiers, and optionally any of the other components mentioned above and below.

In one embodiment, component (iia) is a modifier in form of one or more compounds selected from the group consisting of epoxidised oils based on fatty acid triglycerides.

In one embodiment, component (iia) is a modifier in form of one or more compounds selected from molecules having 3 or more epoxy groups.

In one embodiment, component (iia) is a modifier in form of one or more flexible oligomer or polymer, such as a low Tg acrylic based polymer, such as a low Tg vinyl based polymer, such as low Tg polyether, which contains reactive functional groups such as carbodiimide groups, such as anhydride groups, such as oxazoline groups, such as amino groups, such as epoxy groups.

In one embodiment, component (iia) is one or more modifiers selected from the group consisting of polyethylene imine, polyvinyl amine, fatty amines.

In one embodiment, the component (iia) is one or more modifiers selected from aliphatic multifunctional carbodiimides.

Component (iia) can also be any mixture of the above mentioned compounds.

Without wanting to be bound by any particular theory, it is believed that the excellent binder properties achieved by the binder composition for mineral fibers comprising components (i) and (iia), and optional further components, are at least partly due to the effect that the modifiers used as components (iia) at least partly serve the function of a plasticizer and a crosslinker. In one embodiment, the aqueous binder composition comprises component (iia) in an amount of 1 to 40 wt.-%, such as 4 to 20 wt.-%, such as 6 to 12 wt.-%, based on the dry weight of the component (i).

Further Components

In some embodiments, the aqueous binder composition used in the present invention comprises further components.

In one embodiment, the aqueous binder composition used in the present invention comprises a catalyst selected from inorganic acids, such as sulfuric acid, sulfamic acid, nitric acid, boric acid, hypophosphorous acid, and/or phosphoric acid, and/or any salts thereof such as sodium hypophosphite, and/or ammonium salts, such as ammonium salts of sulfuric acid, sulfamic acid, nitric acid, boric acid, hypophosphorous acid, and/or phosphoric acid. The presence of such a catalyst can improve the curing properties of the aqueous binder compositions according to the present invention.

In one embodiment, the aqueous binder composition used in the present invention comprises a catalyst selected from Lewis acids, which can accept an electron pair from a donor compound forming a Lewis adduct, such as ZnCI 2 , Mg (CIO4) 2 , Sn [N(SO 2 -n-C8F17) 2 ]4.

In one embodiment, the aqueous binder composition according to the present invention comprises a catalyst selected from metal chlorides, such as KCI, MgCI 2 , ZnCI 2 , FeCh and SnCI 2 .

In one embodiment, the aqueous binder composition used in the present invention comprises a catalyst selected from organometallic compounds, such as titanate-based catalysts and stannum based catalysts.

In one embodiment, the aqueous binder composition used in the present invention comprises a catalyst selected from chelating agents, such as transition metals, such as iron ions, chromium ions, manganese ions, copper ions. In one embodiment, the aqueous binder composition used in the present invention further comprises a further component (iv) in form of one or more silanes.

In one embodiment, the aqueous binder composition used in the present invention comprises a further component (iv) in form of one or more coupling agents, such as organofunctional silanes.

In one embodiment, component (iv) is selected from group consisting of organofunctional silanes, such as primary or secondary amino functionalized silanes, epoxy functionalized silanes, such as polymeric or oligomeric epoxy functionalized silanes, methacrylate functionalized silanes, alkyl and aryl functionalized silanes, urea funtionalised silanes or vinyl functionalized silanes.

In one embodiment, the aqueous binder composition used in the present invention further comprises a component (v) in form of one or more components selected from the group of ammonia, amines or any salts thereof.

It has been found that the inclusion of ammonia, amines or any salts thereof as a further component can in particular be useful when oxidized lignins are used in component (i), which oxidised lignin have not been oxidized in the presence of ammonia.

In one embodiment, the aqueous binder composition used in the present invention further comprises a further component in form of urea, in particular in an amount of 5 to 40 wt.-%, such as 10 to 30 wt.-%, 15 to 25 wt.-%, based on the dry weight of component (i).

In one embodiment, the aqueous binder composition used in the present invention further comprises a further component in form of one or more carbohydrates selected from the group consisting of sucrose, reducing sugars, in particular dextrose, polycarbohydrates, and mixtures thereof, preferably dextrins and maltodextrins, more preferably glucose syrups, and more preferably glucose syrups with a dextrose equivalent value of DE = 30 to less than 100, such as DE = 60 to less than 100, such as DE = 60-99, such as DE = 85-99, such as DE = 95- 99.

In one embodiment, the aqueous binder composition used in the present invention further comprises a further component in form of one or more carbohydrates selected from the group consisting of sucrose and reducing sugars in an amount of 5 to 50 wt.- %, such as 5 to less than 50 wt.-%, such as 10 to 40 wt.-%, such as 15 to 30 wt.-% based on the dry weight of component (i).

In the context of the present invention, a binder composition having a sugar content of 50 wt.-% or more, based on the total dry weight of the binder components, is considered to be a sugar based binder. In the context of the present invention, a binder composition having a sugar content of less than 50 wt.-%, based on the total dry weight of the binder components, is considered a non-sugar based binder.

In one embodiment, the aqueous adhesive composition used in the present invention further comprises a further component in form of one or more surface active agents that are in the form of non-ionic and/or ionic emulsifiers such as polyoxyethylenes (4) lauryl ether, such as soy lecithin, such as sodium dodecyl sulfate.

In one embodiment, the aqueous binder composition used in the present invention comprises

- a component (i) in form of one or more ammonia-oxidized lignins having a carboxylic acid group content of 0.05 to 10 mmol/g, such as 0.1 to 5 mmol/g, such as 0.20 to 1.5 mmol/g, such as 0.40 to 1.2 mmol/g, such as 0.45 to 1.0 mmol/g, based on the dry weight of component (i);

- a component (ii) in form of one or more cross-linkers selected from b- hydroxyalkylamide-cross-linkers and/or oxazoline-cross-linkers and/or is one or more cross-linkers selected from the group consisting of multifunctional organic amines such as an alkanolamine, diamines, such as hexamethyldiamine, triamines; - a component (iii) in form of one or more polyethylene glycols having an average molecular weight of 150 to 50000 g/mol, in particular 150 to 4000 g/mol, more particular 150 to 1000 g/mol, preferably 150 to 500 g/mol, more preferably 150 to 300 g/mol, or one or more polyethylene glycols having an average molecular weight of 4000 to 25000 g/mol, in particular 4000 to 15000 g/mol, more particular 8000 to 12000 g/mol; wherein preferably the aqueous binder composition comprises component (ii) in an amount of 1 to 40 wt.-%, such as 4 to 20 wt.-%, 6 to 12 wt.-%, based on the dry weight of component (i), and (iii) is present in an amount of 0.5 to 50, preferably 2.5 to 25, more preferably 3 to 15 wt.-%, based on the dry weight of component (i).

In one embodiment, the aqueous binder composition used in the present invention comprises

- a component (i) in form of one or more ammonia-oxidized lignins having a carboxylic acid group content of 0.05 to 10 mmol/g, such as 0.1 to 5 mmol/g, such as 0.20 to 1.5 mmol/g, such as 0.40 to 1.2 mmol/g, such as 0.45 to 1.0 mmol/g, based on the dry weight of component (i);

- a component (iia) in form of one or more modifiers selected from epoxidised oils based on fatty acid triglycerides.

In one embodiment, the aqueous binder composition used in the present invention comprises

- a component (i) in form of one or more ammonia-oxidized lignins having an average carboxylic acid group content of more than 1.5 groups per macromolecule of component (i), such as more than 2 groups, such as more than 2.5 groups;

- a component (ii) in form of one or more cross-linkers selected from b- hydroxyalkylamide-cross-linkers and/or oxazoline-cross-linkers and/or is one or more cross-linkers selected from the group consisting of multifunctional organic amines such as an alkanolamine, diamines, such as hexamethyldiamine, triamines;

- a component (iii) in form of one or more polyethylene glycols having an average molecular weight of 150 to 50000 g/mol, in particular 150 to 4000 g/mol, more particular 150 to 1000 g/mol, preferably 150 to 500 g/mol, more preferably 150 to 300 g/mol, or one or more polyethylene glycols having an average molecular weight of 4000 to 25000 g/mol, in particular 4000 to 15000 g/mol, more particular 8000 to 12000 g/mol; wherein preferably the aqueous binder composition comprises component (ii) in an amount of 1 to 40 wt.-%, such as 4 to 20 wt.-%, 6 to 12 wt.-%, based on the dry weight of component (i), and (iii) is present in an amount of 0.5 to 50, preferably 2.5 to 25, more preferably 3 to 15 wt.-%, based on the dry weight of component (i).

In one embodiment, the aqueous binder composition used in the present invention comprises

- a component (i) in form of one or more ammonia-oxidized lignins having an average carboxylic acid group content of more than 1.5 groups per macromolecule of component (i), such as more than 2 groups, such as more than 2.5 groups;

- a component (iia) in form of one or more modifiers selected from epoxidised oils based on fatty acid triglycerides.

In one embodiment, the aqueous binder composition used in the present invention consists essentially of

- a component (i) in form of one or more oxidized lignins; a component (ii) in form of one or more cross-linkers; a component (iii) in form of one or more plasticizers; - a component (iv) in form of one or more coupling agents, such as organofunctional silanes;

- optionally a component in form of one or more compounds selected from the group of ammonia, amines or any salts thereof;

- optionally a component in form of urea;

- optionally a component in form of a more reactive or non-reactive silicones;

- optionally a hydrocarbon oil;

- optionally one or more surface active agents;

- water.

In one embodiment, the aqueous binder composition used in the present invention consists essentially of a component (i) in form of one or more oxidized lignins;

- a component (iia) in form of one or more modifiers selected from epoxidised oils based on fatty acid triglycerides;

- a component (iv) in form of one or more coupling agents, such as organofunctional silanes;

- optionally a component in form of one or more compounds selected from the group of ammonia, amines or any salts thereof;

- optionally a component in form of urea;

- optionally a component in form of a more reactive or non-reactive silicones; optionally a hydrocarbon oil; - optionally one or more surface active agents;

- water.

Oxidised lignins which can be used as component in the aqueous binder composition for mineral fibres according to the present invention and method for preparing such oxidised lignins

In the following, we describe oxidised lignins which can be used as component of the binder composition and their preparation.

Method I to prepare oxidised lignins

Oxidised lignins, which can be used as component for the binders used in the present invention can be prepared by a method comprising bringing into contact

- a component (a) comprising one or more lignins

- a component (b) comprising ammonia, one or more amine components, and/or any salt thereof.

- a component (c) comprising one or more oxidation agents.

Component (a)

Component (a) comprises one or more lignins.

In one embodiment of the method, component (a) comprises one or more kraft lignins, one or more soda lignins, one or more lignosulfonate lignins, one or more organosolv lignins, one or more lignins from biorefining processess of lignocellulosic feedstocks, or any mixture thereof.

In one embodiment, component (a) comprises one or more kraft lignins.

Component (b) In one embodiment according to the present invention, component (b) comprises ammonia, one or more amino components, and/or any salts thereof. Without wanting to be bound by any particular theory, it is believed that replacement of the alkali hydroxides used in previously known oxidation processes of lignin by ammonia, one or more amino components, and/or any salts thereof, plays an important role in the improved properties of the oxidised lignins prepared according to the present invention.

It has surprisingly been found that the lignins oxidised by an oxidation agent in the presence of ammonia or amines contain significant amounts of nitrogen as a part of the structure of the oxidised lignins. Without wanting to be bound to any particular theory, it is believed that the improved fire resistance properties of the oxidised lignins when used in products where they are comprised in a binder composition, said oxidised lignins prepared according to the present invention, are at least partly due to the nitrogen content of the structure of the oxidised lignins.

In one embodiment, component (b) comprises ammonia and/or any salt thereof.

Without wanting to be bound by any particular theory, it is believed that the improved stability properties of the derivatized lignins prepared according to the present invention are at least partly due to the fact that ammonia is a volatile compound and therefore evaporates from the final product or can be easily removed and reused. In contrast to that, it has proven difficult to remove residual amounts of the alkali hydroxides used in the previously known oxidation process.

Nevertheless, it can be advantageous in the present invention that component (b), besides ammonia, one or more amino components, and/or any salts thereof, also comprises a comparably small amount of an alkali and/or earth alkali metal hydroxide, such as sodium hydroxide and/or potassium hydroxide.

In the embodiments, in which component (b) comprises alkali and/or earth alkali metal hydroxides, such as sodium hydroxide and/or potassium hydroxide, as a component in addition to the ammonia, one or more amino components, and/or any salts thereof, the amount of the alkali and/or earth alkali metal hydroxides is usually small, such as 5 to 70 weight parts, such as 10 to 20 weight parts alkali and/or earth alkali metal hydroxide, based on ammonia.

Component (c)

In the present invention, component (c) comprises one or more oxidation agents.

In one embodiment, component (c) comprises one or more oxidation agents in form of hydrogen peroxide, organic or inorganic peroxides, molecular oxygen, ozone, air, halogen containing oxidation agents, or any mixture thereof.

In the initial steps of the oxidation, active radicals from the oxidant will typically abstract the proton from the phenolic group as that bond has the lowest dissociation energy in lignin. Due to lignin’s potential to stabilize radicals through mesomerism multiple pathways open up to continue (but also terminate) the reaction and various intermediate and final products are obtained. The average molecular weight can both increase and decrease due to this complexity (and chosen conditions) and in their experiments, the inventors have typically seen moderate increase of average molecular weight of around 30%.

In one embodiment, component (c) comprises hydrogen peroxide.

Hydrogen peroxide is perhaps the most commonly employed oxidant due to combination of low price, good efficiency and relatively low environmental impact. When hydrogen peroxide is used without the presence of catalysts, alkaline conditions and temperature are important due to the following reactions leading to radical formation:

It has been found that the derivatized lignins prepared with the method according to the present invention contain increased amounts of carboxylic acid groups as a result of the oxidation process. Without wanting to be bound by any particular theory, it is believed that the carboxylic acid group content of the oxidised lignins prepared in the process according to the present invention plays an important role in the desirable reactivity properties of the derivatized lignins prepared by the method according to the present invention.

Another advantage of the oxidation process is that the oxidised lignin is more hydrophilic. Higher hydrophilicity can enhance solubility in water and facilitate the adhesion to polar substrates such as mineral fibers.

Further Components

In one embodiment, the method according to the present invention comprises further components, in particular a component (d) in form of an oxidation catalyst, such as one or more transition metal catalyst, such as iron sulfate, such as manganese, palladium, selenium, tungsten containing catalysts.

Such oxidation catalysts can increase the rate of the reaction, thereby improving the properties of the oxidised lignins prepared by the method according to the present invention.

Mass Ratios of the Components

The person skilled in the art will use the components (a), (b) and (c) in relative amounts that the desired degree of oxidation of the lignins is achieved.

In one embodiment,

- a component (a) comprises one or more lignins

- a component (b) comprises ammonia

- a component (c) comprises one or more oxidation agents in form of hydrogen peroxide, wherein the mass ratios of lignin, ammonia and hydrogen peroxide are such that the amount of ammonia is 0.01 to 0.5 weight parts, such as 0.1 to 0.3, such as 0.15 to 0.25 weight parts ammonia, based on the dry weight of lignin, and wherein the amount of hydrogen peroxide is 0.025 to 1.0 weight parts, such as 0.05 to 0.2 weight parts, such as 0.075 to 0.125 weight parts hydrogen peroxide, based on the dry weight of lignin.

Process

There is more than one possibility to bring the components (a), (b) and (c) in contact to achieve the desired oxidation reaction.

In one embodiment, the method comprises the steps of:

- a step of providing component (a) in form of an aqueous solution and/or dispersion of one more lignins, the lignin content of the aqueous solution being 1 to 50 weight-%, such as 5 to 25 weight-%, such as 15 to 22 weight-%, such as 18 to 20 weight-%, based on the total weight of the aqueous solution;

- a pH adjusting step by adding component (b) comprising an aqueous solution of ammonia, one or more amine components, and/or any salt thereof;

- an oxidation step by adding component (c) comprising an oxidation agent.

In one embodiment, the pH adjusting step is carried so that the resulting aqueous solution and/or dispersion is having a pH > 9, such as > 10, such as > 10.5.

In one embodiment, the pH adjusting step is carried out so that the resulting aqueous solution and/or dispersion is having a pH in the range of 10.5 to 12. In one embodiment, the pH adjusting step is carried out so that the temperature is allowed to raise to > 25 °C and then controlled in the range of 25 - 50 °C, such as 30 - 45 °C, such as 35 - 40 °C.

In one embodiment, during the oxidation step, the temperature is allowed to raise > 35 °C and is then controlled in the range of 35 - 150 °C, such as 40 - 90 °C, such as 45 - 80 °C.

In one embodiment, the oxidation step is carried out for a time of 1 second to 48 hours, such as 10 seconds to 36 hours, such as 1 minute to 24 hours such as 2 - 5 hours.

Method II to prepare oxidised lignins

Oxidised lignins, which can be used as component for the binders used in the present invention can be prepared by a method comprising bringing into contact

- a component (a) comprising one or more lignins

- a component (b) comprising ammonia and/or one or more amine components, and/or any salt thereof and/or an alkali and/or earth alkali metal hydroxide, such as sodium hydroxide and/or potassium hydroxide

- a component (c) comprising one or more oxidation agents

- a component (d) in form of one or more plasticizers.

Component (a)

Component (a) comprises one or more lignins.

In one embodiment of the method, component (a) comprises one or more kraft lignins, one or more soda lignins, one or more lignosulfonate lignins, one or more organosolv lignins, one or more lignins from biorefining processess of lignocellulosic feedstocks, or any mixture thereof. In one embodiment, component (a) comprises one or more kraft lignins. Component (b)

In one embodiment, component (b) comprises ammonia, one or more amino components, and/or any salts thereof and/or an alkali and/or earth alkali metal hydroxide, such as sodium hydroxide and/or potassium hydroxide.

“Ammonia-oxidized lignins” is to be understood as a lignin that has been oxidized by an oxidation agent in the presence of ammonia. The term “ammonia-oxidized lignin” is abbreviated as AOL.

In one embodiment, component (b) comprises ammonia and/or any salt thereof.

Without wanting to be bound by any particular theory, it is believed that the improved stability properties of the derivatized lignins prepared according to the present invention with component (b) being ammonia and/or any salt thereof are at least partly due to the fact that ammonia is a volatile compound and therefore evaporates from the final product or can be easily removed and reused.

Nevertheless, it can be advantageous in this embodiment of the method that component (b), besides ammonia, one or more amino components, and/or any salts thereof, also comprises a comparably small amount of an alkali and/or earth alkali metal hydroxide, such as sodium hydroxide and/or potassium hydroxide.

In the embodiments, in which component (b) comprises alkali and/or earth alkali metal hydroxides, such as sodium hydroxide and/or potassium hydroxide, as a component in addition to the ammonia, one or more amino components, and/or any salts thereof, the amount of the alkali and/or earth alkali metal hydroxides is usually small, such as 5 to 70 weight parts, such as 10 to 20 weight parts alkali and/or earth alkali metal hydroxide, based on ammonia.

Component (c) In the method according to the present invention, component (c) comprises one or more oxidation agents.

In one embodiment, component (c) comprises one or more oxidation agents in form of hydrogen peroxide, organic or inorganic peroxides, molecular oxygen, ozone, air, halogen containing oxidation agents, or any mixture thereof.

In the initial steps of the oxidation, active radicals from the oxidant will typically abstract the proton from the phenolic group as that bond has the lowest dissociation energy in lignin. Due to lignin’s potential to stabilize radicals through mesomerism, multiple pathways open up to continue (but also terminate) the reaction and various intermediate and final products are obtained. The average molecular weight can both increase and decrease due to this complexity (and chosen conditions) and in their experiments, we have typically seen moderate increase of average molecular weight of around 30%.

In one embodiment, component (c) comprises hydrogen peroxide.

Hydrogen peroxide is perhaps the most commonly employed oxidant due to combination of low price, good efficiency and relatively low environmental impact. When hydrogen peroxide is used without the presence of catalysts, alkaline conditions and temperature are important due to the following reactions leading to radical formation:

It has been found that the derivatized lignins prepared with the method according to the present invention contain increased amounts of carboxylic acid groups as a result of the oxidation process. Without wanting to be bound by any particular theory, it is believed that the carboxylic acid group content of the oxidized lignins prepared in the process plays an important role in the desirable reactivity properties of the derivatized lignins prepared by the method. Another advantage of the oxidation process is that the oxidized lignin is more hydrophilic. Higher hydrophilicity can enhance solubility in water and facilitate the adhesion to polar substrates such as mineral fibres.

Component (d)

Component (d) comprises one or more plasticizers.

In one embodiment, component (d) comprises one or more plasticizers in form of polyols, such as carbohydrates, hydrogenated sugars, such as sorbitol, erythriol, glycerol, monoethylene glycol, polyethylene glycols, polyethylene glycol ethers, polyethers, phthalates and/or acids, such as adipic acid, vanillic acid, lactic acid and/or ferullic acid, acrylic polymers, polyvinyl alcohol, polyurethane dispersions, ethylene carbonate, propylene carbonate, lactones, lactams, lactides, acrylic based polymers with free carboxy groups and/or polyurethane dispersions with free carboxy groups, polyamides, amides such as carbamide/urea., or any mixtures thereof.

It has been found that the inclusion of component (d) in form of one or more plasticizers provides a decrease of the viscosity of the reaction mixture which allows a very efficient method to produce oxidised lignins.

In one embodiment, component (d) comprises one or more plasticizers in form of polyols, such as carbohydrates, hydrogenated sugars, such as sorbitol, erythriol, glycerol, monoethylene glycol, polyethylene glycols, polyvinyl alcohol, acrylic based polymers with free carboxy groups and/or polyurethane dispersions with free carboxy groups, polyamides, amides such as carbamide/urea, or any mixtures thereof.

In one embodiment, component (d) comprises one or more plasticizers selected from the group of polyethylene glycols, polyvinyl alcohol, urea or any mixtures thereof.

Further Components

In one embodiment, the method comprises further components, in particular a component (v) in form of an oxidation catalyst, such as one or more transition metal catalyst, such as iron sulfate, such as manganese, palladium, selenium, tungsten containing catalysts.

Such oxidation catalysts can increase the rate of the reaction, thereby improving the properties of the oxidized lignins prepared by the method.

Mass Ratios of the Components

The person skilled in the art will use the components (a), (b), (c), and (d) in relative amounts that the desired degree of oxidation of the lignins is achieved.

In one embodiment, the method is carried out such that the method comprises

- a component (a) comprises one or more lignins

- a component (b) comprises ammonia

- a component (c) comprises one more oxidation agents in form of hydrogen peroxide,

- a component (d) comprises one or more plasticizers selected from the group of polyethylene glycol, wherein the mass ratios of lignin, ammonia, hydrogen peroxide and polyethylene glycol are such that the amount of ammonia is 0.01 to 0.5 weight parts, such as 0.1 to 0.3, such as 0.15 to 0.25 weight parts ammonia (25 weight% solution in water), based on the dry weight of lignin, and wherein the amount of hydrogen peroxide (30 weight% solution in water) is 0.025 to 1.0 weight parts, such as 0.07 to 0.50 weight parts, such as 0.15 to 0.30 weight parts hydrogen peroxide, based on the dry weight of lignin, and wherein the amount of polyethylene glycol is 0.03 to 0.60 weight parts, such as 0.07 to 0.50 weight parts, such as 0.10 to 0.40 weight parts polyethylene glycol, based on the dry weight of lignin.

For the purpose of the present invention, the "dry weight of lignin" is preferably defined as the weight of the lignin in the supplied form. Process

There is more than one possibility to bring the components (a), (b), (c), and (d) in contact to achieve the desired oxidation reaction.

In one embodiment, the method comprises the steps of:

- a step of providing component (a) in form of an aqueous solution and/or dispersion of one more lignins, the lignin content of the aqueous solution being 5 to 90 weight-%, such as 10 to 85 weight- %, such as 15 to 70 weight-%, based on the total weight of the aqueous solution;

- a pH adjusting step by adding component (b);

- a step of adding component (d);

- an oxidation step by adding component (c) comprising an oxidation agent.

In one embodiment, the pH adjusting step is carried so that the resulting aqueous solution and/or dispersion is having a pH > 9, such as > 10, such as > 10.5.

In one embodiment, the pH adjusting step is carried out so that the resulting aqueous solution and/or dispersion is having a pH in the range of 9.5 to 12.

In one embodiment, the pH adjusting step is carried out so that the temperature is allowed to raise to > 25 °C and then controlled in the range of 25 - 50 °C, such as 30 - 45 °C, such as 35 - 40 °C.

In one embodiment, during the oxidation step, the temperature is allowed to raise to > 35 °C and is then controlled in the range of 35 - 150 °C, such as 40 - 90 °C, such as 45 - 80 °C.

In one embodiment, the oxidation step is carried out for a time of 1 seconds to 24 hours, such as 1 minutes to 12 hours, such as 10 minutes to 8 hours, such as 5 minutes to 1 hour. It has been found that the process allows to produce a high dry matter content of the reaction mixture and therefore a high throughput is possible in the process which allows the reaction product in form of the oxidised lignins to be used as a component in industrial mass production products such as mineral fibre products.

In one embodiment, the method is carried out such that the dry matter content of the reaction mixture is 20 to 80 wt.%, such as 40 to 70 wt.%.

In one embodiment, the method is carried out such that the viscosity of the oxidised lignin has a value of 100 cP to 100.000 cP, such as a value of 500 cP to 50.000 cP, such as a value of 1.000 cP to 25.000 cP.

For the purpose of the present invention, viscosity is dynamic viscosity and is defined as the resistance of the liquid/paste to a change in shape, or movement of neighbouring portions relative to one another. The viscosity is measured in centipoise (cP), which is the equivalent of 1 mPa s (milipascal second). Viscosity is measured at 20°C using a viscometer. For the purpose of the present invention, the dynamic viscosity can be measured at 20°C by a Cone Plate Wells Brookfield Viscometer.

In one embodiment, the method is carried out such that the method comprises a rotator-stator device.

In one embodiment, the method is carried out such that the method is performed as a continuous or semi-continuous process.

Apparatus for performing the method

The present disclosure also includes an apparatus for performing the method described above.

In one embodiment, the apparatus for performing the method comprises:

- a rotor-stator device,

- a premixing device for component (a), (b), (d) - one or more inlets for water, components (a), (b), (c) and (d),

- one or more outlets for an oxidised lignin.

In one embodiment, the apparatus is constructed in such a way that the inlets for the premix of the components (a), (b) and (d) are to the rotor-stator device and the apparatus furthermore comprises a chamber, said chamber having an inlet for component (c) and said chamber having an outlet for an oxidised lignin.

A rotator-stator device is a device for processing materials comprising a stator configured as an inner cone provided with gear rings. The stator cooperates with a rotor having arms projecting from a hub. Each of these arms bears teeth meshing with the teeth of the gear rings of the stator. With each turn of the rotor, the material to be processed is transported farther outward by one stage, while being subjected to an intensive shear effect, mixing and redistribution. The rotor arm and the subjacent container chamber of the upright device allow for a permanent rearrangement of the material from the inside to the outside and provide for a multiple processing of dry and/or highly viscous matter so that the device is of excellent utility for the intensive mixing, kneading, fibrillating, disintegrating and similar processes important in industrial production. The upright arrangement of the housing facilitates the material's falling back from the periphery toward the center of the device.

In one embodiment, the rotator-stator device used in the method comprises a stator with gear rings and a rotor with teeth meshing with the teeth of the stator. In this embodiment, the rotator-stator device has the following features: Between arms of the rotor protrudes a guiding funnel that concentrates the material flow coming in from above to the central area of the container. The outer surface of the guiding funnel defines an annular gap throttling the material flow. At the rotor, a feed screw is provided that feeds towards the working region of the device. The guiding funnel retains the product in the active region of the device and the feed screw generates an increased material pressure in the center. For more details of the rotator-stator device to be used in one embodiment of the method, reference is made to US 2003/0042344 A1 , which is incorporated by reference.

In one embodiment, the method is carried out such that the method uses one rotator- stator device. In this embodiment, the mixing of the components and the reaction of the components is carried out in the same rotator-stator device.

In one embodiment, the method is carried out such that the method uses two or more rotator-stator devices, wherein at least one rotator-stator device is used for the mixing of the components and at least one rotator-stator device is used for reacting the components.

This process can be divided into two steps:

1. Preparation of the Lignin mass (a)+(b)+(d)

2. Oxidization of the lignin mass

Typically, two different types of rotor-/stator machines are used:

1. Open rotor-/stator machine suitable for blending in the lignin powder into water on a very high concentration (30 to 50 wt-%). Less intensive mixing but special auxiliaries (inlet funnel, screw etc.) to handle highly viscous materials. Lower circumferential speed (up to 15 m/s). The machine can be used as batch system or continuous.

2. Inline rotor-/stator machine which has much higher shear forces - circumferential speeds of up to 55 m/s) - and creates beneficial conditions for a very quick chemical reaction. The machine is to be used continuously.

In the open rotor-/stator system the highly concentrated (45 to 50 wt-%) mass of Lignin/water is prepared. The lignin powder is added slowly to the warm water (30 to 60 deg.C) in which the correct amount of watery ammonia and/or alkali base have been added. This can be done in batch mode, or the materials are added intermittently/continuously creating a continuous flow of mass to the next step.

The created mass should be kept at a temperature of about 60 deg. to keep the viscosity as low as possible and hence the material pumpable. The hot mass of lignin/water at a pH of 9 to 12 is then transferred using a suitable pump, e.g. progressive cavity pump or another volumetric pump, to the oxidation step.

In on embodiment the oxidation is done in a closed rotor-/stator system in a continuous inline reaction. A watery solution of ammonia and/or alkali base is dosed with a dosing pump into the rotor-/stator chamber at the point of highest turbulence/shear. This ensures a rapid oxidation reaction. The oxidized material (AOL) leaves the inline-reactor and is collected in suitable tanks.

Reaction Product

It has surprisingly been found, that the oxidized lignins prepared have very desirable reactivity properties and at the same time display improved fire resistance properties when used in products where they are comprised in a binder composition, and improved long term stability over previously known oxidized lignins.

The oxidised lignin also displays improved hydrophilicity.

An important parameter for the reactivity of the oxidized lignins prepared is the carboxylic acid group content of the oxidized lignins.

In one embodiment, the oxidized lignin prepared has a carboxylic acid group content of 0.05 to 10 mmol/g, such as 0.1 to 5 mmol/g, such as 0.20 to 2.0 mmol/g, such as 0.40 to 1.5 mmol/g, such as 0.45 to 1.0 mmol/g, based on the dry weight of component (a).

Another way to describe the carboxylic acid group content is by using average carboxylic acid group content per lignin macromolecule according to the following formula: Average CO OH functionality

In one embodiment, the oxidized lignin prepared has an average carboxylic acid group content of more than 1.5 groups per macromolecule of component (a), such as more than 2 groups, such as more than 2.5 groups.

Method III to prepare oxidised liqnins

Oxidised lignins, which can be used as a component for the binder used in the present invention can be prepared by a method comprising bringing into contact

- a component (a) comprising one or more lignins,

- a component (b) comprising ammonia and/or one or more amine components, and/or any salt thereof and/or an alkali and/or earth alkali metal hydroxide, such as sodium hydroxide and/or potassium hydroxide,

- a component (c) comprising one or more oxidation agents,

- optionally a component (d) in form of one or more plasticizers, and allowing a mixing/oxidation step, wherein an oxidised mixture is produced, followed by an oxidation step, wherein the oxidised mixture is allowed to continue to react for a dwell time of dwell time of 1 second to 10 hours, such as 10 seconds to 6 hours, such as 30 seconds to 2 hours.

Components (a), (b), (c) and (d) are as defined above under Method II to prepare oxidised lignins.

In one embodiment of the invention, the process comprises a premixing step in which components are brought into contact with each other.

In the premixing step the following components can be brought into contact with each other: - component (a) and component (b), or

- component (a) and component (b) and component (c), or

- component (a) and component (b) and component (d), or

- component (a) and component (b) and component (c) and component (d).

In an embodiment of the invention, it is possible that the premixing step is carried out as a separate step and the mixing/oxidation step is carried out subsequently to the premixing step. In such an embodiment of the invention it is particularly advantageous to bring component (a) and component (b) and optionally component (d) into contact with each other in a premixing step. In a subsequent mixing/oxidation step, component (c) is then added to the premixture produced in the premixing step.

In another example of the invention, it is possible that the premixing step corresponds to the mixing/oxidation step. In this embodiment of the invention, the components, for example component (a), component (b) and component (c) are mixed and an oxidation process is started at the same time. It is possible that the subsequent dwell time is performed in the same device as that used to perform the mixing/oxidation step. Such an implementation of the invention is particularly advantageous if component (c) is air.

It has been found out that by allowing a mixing/oxidation step followed by an oxidation step, in which the reaction mixture is preferably not continued to be mixed, the oxidation rate can be controlled in a very efficient manner. At the same time, the costs for performing the method are reduced because the oxidation step subsequent to the mixing/oxidation step requires less complex equipment.

Another advantage is that oxidized lignin, which is produced is particularly stable. Another surprising advantage is that the oxidized lignin produced is very well adjustable in terms of viscosity. Another surprising advantage is that the concentration of the oxidized lignin can be very high. In one embodiment, the dwell time is so chosen that the oxidation reaction is brought to the desired degree of completion, preferably to full completion.

System I for performing the method III

In one embodiment, the system for performing the method comprises:

- at least one rotor-stator device,

- one or more inlets for water and components (a) and (b),

- one or more outlets of the rotor-stator device,

- at least one reaction device, in particular at least one reaction tube, which is arranged downstream in the process flow direction to at least one or more of the outlets.

In one embodiment, the system comprises one or more inlets for component (c) and/or component (d).

In one embodiment, the system comprises a premixing device.

The premixing device can comprise one or more inlets for water and/or component (a) and/or component (b) and/or component (c) and/or component (d).

In one embodiment, the premixing device comprises inlets for water and component (a) and component (b).

It is possible that, in a premixing step, component (c) is also mixed with the three mentioned ingredients (water, component (a) and component (b)). It is then possible that the premixing device has a further inlet for component (c). If component (c) is air, it is possible that the premixing device is formed by an open mixing vessel, so that in this case component (c) is already brought into contact with the other components (water, component (a) and component (b)) through the opening of the vessel. Also in this embodiment of the invention, it is possible that the premixing device optionally comprises an inlet for component (d). In one embodiment, the system is constructed in such a way that the inlets for components (a), (b) and (d) are inlets of a premixing device, in particular of an open rotor-stator device, whereby the system furthermore comprises an additional rotor-stator device, said additional rotor-stator device having an inlet for component (c) and said additional rotor-stator device having an outlet for an oxidized lignin.

It is possible that the premixing step and the mixing/oxidizing step are carried out simultaneously. In this case, the premixing device and the mixing/oxidizing device are a single device, i. e. a rotor-stator device.

In one embodiment, one rotator-stator device used in the method according to the present invention comprises a stator with gear rings and a rotor with teeth meshing with the teeth of the stator. In this embodiment, the rotator-stator device has the following features: Between arms of the rotor protrudes a guiding funnel that concentrates the material flow coming in from above to the central area of the container. The outer surface of the guiding funnel defines an annular gap throttling the material flow. At the rotor, a feed screw is provided that feeds towards the working region of the device. The guiding funnel retains the product in the active region of the device and the feed screw generates an increased material pressure in the center.

System II for performing the method III

In one embodiment, the system for performing the method comprises:

- one or more inlets for water, components (a) and (b),

- at least one mixing and oxidizing apparatus with one or more outlets, and

- at least one mixer/heat-exchanger, which is arranged downstream in the process flow direction to the at least one or more of the outlets, whereby the mixer/heat-exchanger comprises a temperature control device.

In one embodiment, the system comprises additional one or more inlets for component (c) and/or component (d).

In one embodiment, the system comprises a premixing device.

The premixing device can comprise one or more inlets for water and/or component (a) and/or component (b) and/or component (c) and/or component (d).

In one embodiment, the premixing device comprises inlets for water and component (a) and component (b).

It is possible that, in a premixing step, component (c) is also mixed with the three mentioned ingredients (water, component (a) and component (b)). It is then possible that the premixing device has a further inlet for component (c). If component (c) is air, it is possible that the premixing device is formed by an open mixing vessel, so that in this case component (c) is already brought into contact with the other components (water, component (a) and component (b)) through the opening of the vessel. Also in this embodiment of the invention, it is possible that the premixing device optionally comprises an inlet for component (d).

In one embodiment, the system is constructed in such a way that the inlets for components (a), (b) and (d) are inlets of an open rotor-stator device, whereby the system furthermore comprises a mixer/heat-exchanger, having an inlet for component (c) and an outlet for an oxidized lignin.

It is possible that the premixing step and the mixing/oxidizing step are carried out simultaneously. In this case, the premixing device and the mixing/oxidizing device are a single device.

In one embodiment, one rotator-stator device used in the method according to the present invention comprises a stator with gear rings and a rotor with teeth meshing with the teeth of the stator. In this embodiment, the rotator-stator device has the following features: Between arms of the rotor protrudes a guiding funnel that concentrates the material flow coming in from above to the central area of the container. The outer surface of the guiding funnel defines an annular gap throttling the material flow. At the rotor, a feed screw is provided that feeds towards the working region of the device. The guiding funnel retains the product in the active region of the device and the feed screw generates an increased material pressure in the center.

Of course other devices can also be used as premixing devices. Furthermore, it is possible that the premixing step is carried out in the mixing and oxidizing apparatus.

In one embodiment, the mixing and oxidizing apparatus is a static mixer. A static mixer is a device for the continuous mixing of fluid materials, without moving components. One design of static mixer is the plate-type mixer and another common device type consists of mixer elements contained in a cylindrical (tube) or squared housing.

In one embodiment, the mixer/heat-exchanger is constructed as multitube heat exchanger with mixing elements. The mixing element are preferably fixed installations through which the mixture has to flow, whereby mixing is carried out as a result of the flowing through. The mixer/heat-exchanger can be constructed as a plug flow reactor.

Examples I

Example IA- lignin oxidation in ammonia aqueous solution by hydrogen peroxide:

The amounts of ingredients used according to the example IA are provided in table IA 1.1 and IA 1.2.

Although kraft lignin is soluble in water at relatively high pH, it is known that at certain weight percentage the viscosity of the solution will strongly increase. It is typically believed that the reason for the viscosity increase lies in a combination of strong hydrogen bonding and interactions of p-electrons of numerous aromatic rings present in lignin. For kraft lignin an abrupt increase in viscosity around 21-22 wt.-% in water was observed and 19 wt.-% of kraft lignin were used in the example presented. Ammonia aqueous solution was used as base in the pH adjusting step. The amount was fixed at 4 wt.-% based on the total reaction weight. The pH after the pH adjusting step and at the beginning of oxidation was 10.7.

Table IA2 shows the results of CHNS elemental analysis before and after oxidation of kraft lignin. Before the analysis, the samples were heat treated at 160 °C to remove adsorbed ammonia. The analysis showed that a certain amount of nitrogen became a part of the structure of the oxidised lignin during the oxidation process.

During testing in batch experiments, it was determined that it is beneficial for the oxidation to add the entire amount of hydrogen peroxide during small time interval contrary to adding the peroxide in small portions over prolonged time period. In the present example 2.0 wt.-% of H2O2 based on the total reaction weight was used.

The oxidation is an exothermic reaction and increase in temperature is noted upon addition of peroxide. In this example, temperature was kept at 60 °C during three hours of reaction.

After the oxidation, the amount of lignin functional groups per gram of sample increased as determined by 31 P NMR and aqueous titration. Sample preparation for 31 P NMR was performed by using 2-chloro-4,4,5,5-tetramethyl-1 ,3,2- dioxaphospholane (TMDP) as phosphitylation reagent and cholesterol as internal standard. NMR spectra of kraft lignin before and after oxidation were made and the results are summarized in table IA3.

The change in COOH groups was determined by aqueous titration and utilization of the following formula:

Where V2s and Vu are endpoint volumes of a sample while V 2b and Vi b are the volume for the blank. C acid is 0.1M HCI in this case and m s is the weight of the sample. The values obtained from aqueous titration before and after oxidation are shown in table IA4. The average COOH functionality can also be quantified by a saponification value which represents the number of mg of KOH required to saponify 1 g lignin. Such a method can be found in AOCS Official Method Cd 3-25.

Average molecular weight was also determined before and after oxidation with a PSS PolarSil column (9:1 (v/v) dimethyl sulphoxide/water eluent with 0.05 M LiBr) and UV detector at 280nm. Combination of COOH concentration and average molecular weight also allowed calculating average carboxylic acid group content per lignin macromolecule and these results are shown in table IA5.

Example IB - upscaling the lignin oxidation in ammonia by hydrogen peroxide to pilot scale

Lignin oxidation with hydrogen peroxide is an exothermic process and even in lab- scale significant temperature increases were seen upon addition of peroxide. This is a natural concern when scaling up chemical processes since the amount of heat produced is related to dimensions in the 3 rd power (volume) whereas cooling normally only increase with dimension squared (area). In addition, due to the high viscosity of the adhesive intermediates process equipment has to be carefully selected or designed. Thus, the scale up was carefully engineered and performed in several steps.

The first scale up step was done from 1 L (lab scale) to 9 L using a professional mixer in stainless steel with very efficient mechanical mixing The scale-up resulted only in a slightly higher end temperature than obtained in lab scale, which was attributed to efficient air cooling of the reactor and slow addition of hydrogen peroxide

The next scale up step was done in a closed 200 L reactor with efficient water jacket and an efficient propeller stirrer. The scale was this time 180 L and hydrogen peroxide was added in two steps with appr. 30 minute separation. This up-scaling went relatively well, though quite some foaming was an issue partly due to the high degree reactor filling. To control the foaming a small amount of food grade defoamer was sprayed on to the foam. Most importantly the temperature controllable and end temperatures below 70 °C were obtained using external water-cooling. The pilot scale reactions were performed in an 800 L reactor with a water cooling jacket and a twin blade propeller stirring. 158 kg of lignin (UPM LignoBoost TM BioPiva 100) with a dry-matter content of 67 wt.-% was de-lumped and suspended in 224 kg of water and stirred to form a homogenous suspension. With continued stirring 103 kg of 25% ammonia in water was pumped into the reactor and stirred another 2 hours to from a dark viscous solution of lignin.

To the stirred lignin solution 140 kg of 7.5wt.-% at 20-25 °C hydrogen peroxide was added over 15 minutes. Temperature and foam level was carefully monitored during and after the addition of hydrogen peroxide and cooling water was added to the cooling jacket in order to maintain an acceptable foam level and a temperature rise less than 4 °C per minute as well as a final temperature below 70 °C. After the temperature increase had stopped, cooling was turned off and the product mixture was stirred for another 2 hours before transferring to transport container.

Based on the scale up runs it could be concluded that even though the reactions are exothermic a large part of the reaction heat is actually balanced out by the heat capacity of the water going from room temperature to about 60 °C, and only the last part has to be removed by cooling. It should be noted that due to this and due to the short reaction time this process would be ideal for a scale up and process intensification using continuous reactors such as in- line mixers, tubular reactors or CSTR type reactors. This would ensure good temperature control and a more well- defined reaction process.

Tests of the scale up batches indicated the produced oxidised lignin had properties in accordance to the batches produced in the lab. Table IA 1.1

The amounts of materials used in their supplied form: material wt.-%

UPM BioPiva 100, kraft lignin 28

H 2 O 2, 30 wt.-% solution in water 6.6

NH 3, 25wt.-%, aqueous solution 16 water 49.4

Table IA 1.2

The amounts of active material used: material wt.-% kraft lignin 19

H 2 O 2 2

NH 3 4 water 75 Table IA 2

Elemental analysis of kraft lignin before and after oxidation: sample N (wt. -%) C (wt.-%) H (wt.-%) S (wt. -%) kraft lignin 0.1 64.9 5.8 1.7 ammonia oxidised kraft

1.6 65.5 5.7 1.6 lignin

Table IA 3

Kraft lignin functional group distribution before and after oxidation obtained by 31 P- NMR:

Concentration (mmol/g) sample Aliphatic OH Phenolic OH Acid OH kraft lignin 1.60 3.20 0.46 ammonia oxidised kraft lignin 2.11 3.60 0.80

Table IA 4

COOH group content in mmol/g as determined by aqueous titration: sample COOH groups (mmol/g) kraft lignin 0.5 ammonia oxidised kraft

0.9 lignin

Table IA 5

Table IA 5. Number (Mn) and weight (Mw) average molar masses as determined by size exclusion chromatography expressed in g/mol together with average carboxylic acid group content per lignin macromolecule before and after oxidation sample Mn, g/mol Mw, g/mol average COOH functionality kraft lignin 1968 21105 0.9 ammonia oxidised kraft lignin 2503 34503 2.0

Examples II

In the following examples, several oxidised lignins were prepared.

The following properties were determined for the oxidised lignins:

Component solids content:

The content of each of the components in a given oxidised lignin solution is based on the anhydrous mass of the components or as stated below. Kraft lignin was supplier by UPM as BioPivalOO™ as dry powder. NH 4 OH 25% was supplied by Sigma-Aldrich and used in supplied form. H2O2, 30% (Cas no 7722-84-1) was supplied by Sigma-Aldrich and used in supplied form or by dilution with water. PEG 200 was supplied by Sigma-Aldrich and were assumed anhydrous for simplicity and used as such. PVA (Mw 89.000-98.000, Mw 85.000-124.000, Mw 130.000, Mw 146.000-186.000) (Cas no 9002-89-5) were supplied by Sigma-Aldrich and were assumed anhydrous for simplicity and used as such. Urea (Cas no 57-13-6) was supplied by Sigma-Aldrich and used in supplied form or diluted with water. Glycerol (Cas no 56-81-5) was supplied by Sigma-Aldrich and was assumed anhydrous for simplicity and used as such.

Oxidised lignin solids

The content of the oxidised lignin after heating to 200 °C for 1h is termed “Dry solid matter” and stated as a percentage of remaining weight after the heating.

Disc-shaped stone wool samples (diameter: 5 cm; height 1 cm) were cut out of stone wool and heat-treated at 580 °C for at least 30 minutes to remove all organics. The solids of the binder mixture were measured by distributing a sample of the binder mixture (approx. 2 g) onto a heat treated stone wool disc in a tin foil container. The weight of the tin foil container containing the stone wool disc was weighed before and directly after addition of the binder mixture. Two such binder mixture loaded stone wool discs in tin foil containers were produced and they were then heated at 200 °C for 1 hour. After cooling and storing at room temperature for 10 minutes, the samples were weighed and the dry solids matter was calculated as an average of the two results.

COOH group content

The change in COOH group content was also determined by aqueous titration and utilization of the following formula:

Where V 2s and V 1s are endpoint volumes of a sample while V 2b and V 1b are the volume for a blank sample. C acid is 0.1 M HCI in this case and m s,g is the weight of the sample.

Method of producing an oxidised lignin:

1) Water and lignin was mixed in a 3-necked glass bottomed flask at water bath at room temperature (20-25°C) during agitation connected with a condenser and a temperature logging device. Stirred for 1h.

2) Ammonia was added during agitation in 1 portion.

3) Temperature increased to 35°C by heating, if the slightly exothermic reaction with ammonia does not increase the temperature.

4) pH was measured.

5) Plasticizer PEG200 was added and stirred 10 min.

6) After the lignin was completely dissolved after approximately 1 hour, 30% H 2 O 2 was added slowly in one portion.

7) The exothermic reaction by addition of H 2 O 2 increased the temperature in the glass bottomed flask - if the reaction temperature was lower than 60C, the temperature was increased to 60°C and the sample was left at 60°C for 1 hour.

8) The round bottomed flask was then removed from the water bath and cooled to room temperature.

9) Samples were taken out for determination of dry solid matter, COOH, viscosity, density and pH. Oxidised lignin compositions

In the following, the entry numbers of the oxidised lignin example correspond to the entry numbers used in Table II.

Example IIA

71 ,0 g lignin UPM Biopiva 100 was dissolved in 149,0 g water at 20°C and added 13,3 g 25% NH 4 OH and stirred for 1h by magnetic stirrer, where after 16, 8g H 2 O 2 30% was added slowly during agitation. The temperature was increased to 60°C in the water bath. After 1h of oxidation, the water bath was cooled and hence the reaction was stopped. The resulting material was analysed for COOH, dry solid matter, pH, viscosity and density.

Example ME

71 ,0 g lignin UPM Biopiva 100 was dissolved in 88,8 g water at 20°C and added 13,3 g 25% NH 4 OH and stirred for 1h by magnetic stirrer. PEG 200, 22, 8g was added and stirred for 10 min, where after 16,7 g H 2 O 2 30% was added slowly during agitation. The temperature was increased to 60°C in the water bath. After 1h of oxidation, the water bath was cooled and hence the reaction was stopped. The resulting material was analysed for COOH, dry solid matter, pH, viscosity and density.

Example IIC

71 ,0 g lignin UPM Biopiva 100 was dissolved in 57,1 g water at 20°C and added 13,3 g 25% NH 4 OH and stirred for 1h by mechanical stirrer, where after 16,6 g H 2 O 2 30% was added slowly during agitation. The temperature was increased to 60°C in the water bath. After 1h of oxidation, the water bath was cooled and hence the reaction was stopped. The resulting material was analysed for COOH, dry solid matter, pH, viscosity and density.

Example IIF 71 ,0 g lignin UPM Biopiva 100 was dissolved in 57,1 water at 20°C and added 13,3 g 25% NH 4 OH and stirred for 1h by mechanical stirrer. PEG 200, 19,0 g was added and stirred for 10 min, where after 16,6g H 2 O 2 30% was added slowly during agitation. The temperature was increased to 60°C in the water bath. After 1h of oxidation, the water bath was cooled and hence the reaction was stopped. The resulting material was analysed for COOH, dry solid matter, pH, viscosity and density.

TABLE 11 A

Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex. Ex.

Example

IIA MB IIC 11 D ME 11 F IIG 11 H Ill IIJ IIK ML MM IIN MO IIP IIQ MR MS

Materials

, weight in grams:

112, 149,

Lignin 71,0 71,0 71,0 71,0 71,0 71,0 71,0 71,0 71,0 71,0 71,0 71,0 71,0 71,0 71,0 71,0 93,5

3 5

149,

Water 88,8 57,1 17,7 88,8 57,1 17,7 88,8 57,1 17,7 88,8 57,1 17,7 88,8 57,1 17,7 117 90,3 37,3

0

NH4OH

(25 wt%

13,3 13,3 13,3 13,4 13,3 13,3 13,4 13,3 13,3 13,4 13,3 13,3 13,4 13,3 13,3 13,4 17,5 21 28,3 solution in water) H 2 O 2 (30 16,8 16,7 16,6 17,2 16,7 16,6 17,2 16,7 16,6 17,2 16,7 16,6 17,2 16,7 16,6 17,2 22 26,3 36,3 wt%

solution in water)

PEG200 0,0 0,0 0,0 0,0 22,8 19,0 14,2 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0 0,0

PVA 0 0 0 0 0 0 0 5 10 15 0 0 0 0 0 0 0 0 0

Urea (25 wt%

0 0 0 0 0 0 0 0 0 0 3,2 3,8 5,0 0 0 0 0 0 0 solution in water)

Glycerol 0 0 0 0 0 0 0 0 0 0 0 0 0 16,0 21 ,0 30,0 0 0 0

Sorbitol 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 16,0 21 ,0 30,0

Dry solid matter in

%,

18,2 27,1 30,5 40,1 26,5 33 40,3 28,2 34,4 46,3 25,1 30,2 40,2 25,3 29,3 40,3 25,3 30,5 38,8

200°C,

1h

pH 9,5 9,5 9,5 9,5 9,5 9,5 9,5 9,5 9,5 9,5 9,5 9,5 9,5 9,5 9,5 9,5 9,5 9,5 9,5 abov abov

Viscosity, 450, 2500 e e 1500 2500 5000 1500 2500 5000 1500 2500 5000 1500 2500 5000 1500 2500 5000

20°C cP 5 0 1000 1000 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

00 00

Appeara *** * * *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** nee

COOH,

1 ,1 0,9 0,9 0,8 0,8 1 ,9 - - - - - - - - - - - - - mmol/g

Initial lignin cone.

0,32 0,44 0,55 0,80 0,44 0,55 0,80 0,44 0,55 0,80 0,44 0,55 0,80 0,44 0,55 0,80 0,44 0,55 0,80

Weight fraction of aq. sol. r inhomogenous black thick solution; [**] b ack solution; [***] homogenous b ack thick solution.

Example III:

8,5 I hot water (50 °C) and 1,9 I NH 4 OH (24,7%) was mixed, where after 9,0 kg lignin (UPM biopiva 100) was added slowly over 10 minutes at high agitation (660 rpm, 44 Hz). The temperature increased by high shear forces. After 30 minutes, 4 I of hot water was added, and the material was stirred for another 15 minutes before adding the remaining portion of hot water (5 I). Samples were taken out for analyses of un-dissolved lignin by use of a Hegman Scale and pH measurements. This premix was then transferred to a rotor-stator device and a reaction device where the oxidation was made by use of H 2 0 2 (17,5 vol%). The reaction device used in this case has at least partially a reaction tube and a reaction vessel. Dosage of the premixture was 150 l/h and the H 2 0 2 was dosed at 18 l/h.

In the present case, a Cavitron CD1000 rotor-stator device was used to carry out the mixing/oxidation step. The rotor-stator device was run at 250 Hz (55 m/s circumferential speed) with a counter pressure at 2 bar. The dwell time in the reaction tube was 3,2 minutes and in the reaction vessel 2 hours.

Temperature of the premixture was 62 °C, and the oxidation step increased the temperature to 70°C. The final product was analysed for the COOH group content, dry solid matter, pH, viscosity and remaining H 2 0 2 . Table III:

Dry solid matter, COOH,

200C, mmol/g

Example 1 h, % solids pH viscosity

III 22,3 1 ,13 9,6 medium

Example IV:

484 I hot water (70 °C) and 47,0 I NH 4 OH (24,7 %) was mixed, where after 224,0 kg lignin (UPM biopiva 100) was added slowly over 15 minutes at high agitation. Samples were taken out for analyses of un-dissolved lignin by use of a Hegman Scale and pH measurements.

This premixture was then transferred to a static mixer and a mixer/heat- exchanger, where the oxidation was made by use of H 2 O 2 (35 vol%). Dosage of the premixture was 600 l/h and the H 2 O 2 was dosed at 17,2 l/h. The dwell time in the mixer/heat-exchanger was 20 minutes.

The temperature of the mixture increased during the oxidation step up to 95 °C.

The final product was analysed for the COOH group content, dry solid matter, pH, viscosity and remaining H 2 O 2 . A binder was made based on this AOL: 49,3 g AOL (19,0 % solids), 0,8 g primid XL552 (100 % solids) and 2,4 g PEG200 (100 % solids) were mixed with 0,8 g water to yield 19% solids; and then used for test of mechanical properties in bar tests. Primid XL 552 has the structure:

Bar tests The mechanical strength of the binders was tested in a bar test. For each binder, 16 bars were manufactured from a mixture of the binder and stone wool shots from the stone wool spinning production.

A sample of this binder solution having 15% dry solid matter (16.0 g) was mixed well with shots (80.0 g). The resulting mixture was then filled into four slots in a heat resistant silicone form for making small bars (4x5 slots per form; slot top dimension: length = 5.6 cm, width = 2.5 cm; slot bottom dimension: length = 5.3 cm, width = 2.2 cm; slot height = 1.1 cm). The mixtures placed in the slots were then pressed with a suitably sized flat metal bar to generate even bar surfaces. 16 bars from each binder were made in this fashion. The resulting bars were then cured at 200 °C. The curing time was 1 h. After cooling to room temperature, the bars were carefully taken out of the containers. Five of the bars were aged in a water bath at 80 °C for 3 h.

After drying for 1-2 days, the aged bars as well as five unaged bars were broken in a 3 point bending test (test speed: 10.0 mm/min; rupture level: 50%; nominal strength: 30 N/mm 2 ; support distance: 40 mm; max deflection 20 mm; nominal e- module 10000 N/mm 2 ) on a Bent Tram machine to investigate their mechanical strengths. The bars were placed with the “top face” up (i.e. the face with the dimensions length = 5.6 cm, width = 2.5 cm) in the machine.

AOL characteristics Bar tests

COOH Aged strength solids, (mmol/ (kN)

Sample 200C, 9 Viscosit initial strength name 1 h, % solids) y (kN)

Ex IV 17,7 1 ,69 low 0,28 0,11

Description of the Figures

Figure 1 shows a section from a possible lignin structure. Figure 2 shows examples of lignin precursors and common interunit linkages.

Figure 3 shows the at least four groups of technical lignins available in the market.

Figure 4 shows a summary of the properties of some technical lignins.

Figure 5 shows a side view through a spinning apparatus in a spinning chamber. Figure 6 shows a front view of the spinning apparatus.

Figure 7 shows a cross section through a single spinning wheel.

In Figures 5 and 6 the melt flows downwardly in the direction of the arrow on to the surface of the first spinning wheel 4. It is then thrown on to the second wheel 5 and subsequent wheels 6 and 7, from which fibres are formed. Fibres are thrown off the wheels as a cloud and collected as a web on the conveyor 22. Cooling water containing silane is supplied via the second, third and fourth spinning wheels.

A more detailed view is given in Figure 7, which is a cross-section through the third spinning wheel. Fibres 29 are formed at the surfaces of the wheel. An air stream is shown by the arrows 30. This blows the fibres off the surface of the wheel and into a cloud. Cooling water 27 is passed through conduits 28 and through the interior of the spinning wheel and out of an opening in the front face of the wheel so as to cool the fibres as they are forming. The cooling water contains silane. Aqueous binder composition 24 is passed through a conduit (not shown) and through a filter (also not shown) and then into further conduit 25 through the centre of the spinning wheel and out of a binder nozzle 18, so as to contact the fibres as they are forming. Consequently the fibres in the cloud are contacted with silane and binder before they are collected as a web (not shown).

Examples

In the examples below we give the results of tests using the method according to the invention wherein the defined binder is used, with silane added separately. This is compared with equivalent methods using a phenyl urea formaldehyde binder.

MMVF stone wool fibres were produced by melting a mineral charge in a cupola furnace and fiberizing using a cascade spinner having 4 wheels. Various different binders were used. The fibres were collected and consolidated and the consolidated web was passed through a curing oven at 275°C. The rate of production was 15 tonnes wool per hour. Cooling water was supplied as described in Figure 7 above. Gamma-aminopropyltriethoxysilane (Momentive VS-142) was supplied in the cooling water at a level so as to provide 0.5% silane based on the dry solid matter of the binder.

The density and thickness of the samples is given in the table.

The samples were tested for delamination strength, moisture resistance, water absorption and compression strength, both unaged and after ageing in a climate chamber. Results are given below.

Delamination, Thickness Density Unaged Climate Autoclave Ign. loss chamber at aged in % of unaged CIG 70 "

C/95%

7 days 14 days 28 days 15 min

Example mm kg/m3 kPa % % % % %

PUF binder, silane in

1 cooling water 100 142 41.4 84.5 88.3 78.6 62.8 3.78

(comparative)

2 Invention binder 99 138 33.9 89.9 91.5 70.8 73.1 3.97

3 Invention binder 100 145 29.8 90.5 93.9 83.3 72.5 3.55

4 Invention binder 100 145 28.5 90.6 92.8 83.9 78 3.61

5 Invention binder 100 145 27.7 89.5 85.3 77.2 73.8 3.65

PUF binder silane in

6 100 145 38.8 67.8 74.8 75.8 31.5 3.58 cooling water

PUF binder conventional

7 100 145 39 77 64 68 49 3.76 silane dosing

5

Climate chamber at Rl 70 ° C/95% Autoclave

Example

Moisture resistance

7 days 14 days 28 days 15 min

% % % %

1 PUF binder, silane in cooling water (comparative) 0 0 0 0

2 Invention binder 0 0 0.1 0.1

3 Invention binder 0 0 0 0.2

4 Invention binder 0 0.1 0.2 0.4

5 Invention binder 0 0 0.2 0.3

6 PUF binder, silane in cooling water (comparative) 0 0 0 0.7

7 PUF binder conventional silane dosing 0 0 0.1 0.5

24 hours

Oil 24 hours

Example Water absorption Top Bottom

% kg/ m2 kg/ m2 kg/m2

1 PUF binder, silane in cooling water (comparative) 0.12 0.17 0.12 0.22

2 Invention binder 0.08 0.9 0.12 0.06

3 Invention binder 0.1 0.23 0.31 0.14

4 Invention binder 0.1 0.11 0.12 0.09

5 Invention binder 0.1 0.11 0.14 0.08

6 PUF binder, silane in cooling water (comparative) 0.11 0.08 0.11 0.06

7 PUF binder conventional silane dosing 0.1 0.2 0.1 0.11

Sigm Sigm

Example a a

Compression c 0.1

PUF binder, silane in cooling water

1 75 85.7

(comparative)

2 Invention binder 66.1 75.4 ^

3 Invention binder 51.3 58.9

4 Invention binder 54.6 62

5 Invention binder 55.8 63.9

PUF binder, silane in cooling water

6 72.5 82.7

(comparative)

7 PUF binder conventional silane dosing 68 76

These results show that the method according to the invention leads to delamination strength behaviour, moisture resistance, water absorption and compression strength after ageing which are comparable to, and in some cases better than those given by phenol urea formaldehyde binder, despite the fact that silane is not supplied in the conventional manner through the binder composition.

It was not possible to supply silane as a blend with the binder in the cases of Examples 2 to 5 because the filters blocked after a matter of minutes.

In the following examples, several oxidized lignins which can be used to make the binders used in the present invention were prepared.

The following properties were determined for the oxidized lignins according to the present invention:

Component solids content:

The content of each of the components in a given oxidized lignin solution is based on the anhydrous mass of the components or as stated below.

Kraft lignin was supplier by UPM as BioPivalOO™ as dry powder at 67% dry solid matter. NH 4 OH 24.7% was supplied by Univar and used in supplied form. H2O2, 35% (Cas no 7722-84-1) was supplied by Univar and used in supplied form or by dilution with water. PEG 200 was supplied by Univar and were assumed anhydrous for simplicity and used as such. KOH was supplied by Sigma Aldrich and used in the supplied form; assumed to be anhydrous for simplicity.

Oxidized lignin solids

The content of the oxidized lignin after heating to 200 °C for 1h is termed “Dry solid matter” and stated as a percentage of remaining weight after the heating. Disc-shaped stone wool samples (diameter: 5 cm; height 1 cm) were cut out of stone wool and heat-treated at 580 °C for at least 30 minutes to remove all organics. The solids of the binder mixture were measured by distributing a sample of the binder mixture (approx. 2 g) onto a heat treated stone wool disc in a tin foil container. The weight of the tin foil container containing the stone wool disc was weighed before and directly after addition of the binder mixture. Two such binder mixture loaded stone wool discs in tin foil containers were produced and they were then heated at 200 °C for 1 hour. After cooling and storing at room temperature for 10 minutes, the samples were weighed and the dry solids matter was calculated as an average of the two results.

Binder for Example 1 , 6, 7 (comparative example with Phenol-formaldehyde resin modified with urea and dextrose, a PUF-resol):

This binder is a phenol-formaldehyde resin modified with urea, a PUF-resol.

A phenol-formaldehyde resin is prepared by reacting 37% aq. formaldehyde (606 kg) and phenol (189 kg) in the presence of 46% aq. potassium hydroxide (25.5 kg) at a reaction temperature of 84°C preceded by a heating rate of approximately 1°C per minute. The reaction is continued at 84 °C until the acid tolerance of the resin is 4 and most of the phenol is converted. Urea (241 kg) is then added and the mixture is cooled. The acid tolerance (AT) expresses the number of times a given volume of a binder can be diluted with acid without the mixture becoming cloudy (the binder precipitates). Sulfuric acid is used to determine the stop criterion in a binder production and an acid tolerance lower than 4 indicates the end of the binder reaction. To measure the AT, a titrant is produced from diluting 2.5 ml cone, sulfuric acid (>99 %) with 1 L ion exchanged water. 5 ml_ of the binder to be investigated is then titrated at room temperature with this titrant while keeping the binder in motion by manually shaking it; if preferred, use a magnetic stirrer and a magnetic stick. Titration is continued until a slight cloud appears in the binder, which does not disappear when the binder is shaken.

The acid tolerance (AT) is calculated by dividing the amount of acid used for the titration (ml_) with the amount of sample (ml_):

AT = (Used titration volume (ml_)) / (Sample volume (ml_))

Using the urea-modified phenol-formaldehyde resin obtained, a binder is made by addition of 25% aq. ammonia (90 L) and ammonium sulfate (13.2 kg) followed by water (1300 kg). To the above mix is added 18% Dextrose (127.5 kg) based upon the dry matter of the above binder and the dextrose. The binder solids were then measured as described above and the mixture was diluted with the required amount of water and silane (15 % binder solids solution, 0.5% silane of binder solids) for production of an insulation product. Binder for Example 2 and 3 :

3267 kg of water is charged in 6000 I reactor followed by 287 kg of ammonia water (24.7%). Then 1531 kg of Lignin UPM BioPiva 100 is slowly added over a period of 30 min to 45 min. The mixture is heated to 40°C and kept at that temperature for 1 hour. After 1 hour is a check made on insolubilized lignin. This can be made by checking the solution on a glass plate or a Hegman gauge. Insolubilized lignin is seen as small particles in the brown binder. During the dissolution step will the lignin solution change color from brown to shiny black.

After the lignin is completely dissolved, 1 liter of a foam dampening agent (Skumdaemper 11-10 from NCA-Verodan ) is added. Temperature of the batch is maintained at 40°C. Then addition of 307,5 kg 35% hydrogen peroxide is started. The hydrogen peroxide is dosed at a rate of 200-300 liter/hour. First half of the hydrogen peroxide is added at a rate of 200 l/h where after the dosage rate is increased to 300 liter/hour. During the addition of hydrogen peroxide is the temperature in the reaction mixture controlled by heating or cooling in such a way that a final reaction temperature of 65°C is reached.

After 15 min reaction at 65°C is the reaction mixture cooled to a temperature below 50°C. Hereby is a resin obtained having a COOH value of 1.2 mmol/g solids.

Final binder preparation

From the above mentioned AOL resin a binder was formulated by addition of 270 kg polyethylene glycol 200 and 433 kg of a 31% solution of Primid XL-552 in water. Binder for Example 4:

Oxidised lignin as described in Example 2 was used to prepare the final binder. From the above mentioned AOL resin a binder was formulated by addition of 270 kg polyethylene glycol 200 and 359 kg of a 31% solution of Primid XL-552 in water. Binder for Example 5 :

Oxidised lignin as described in Example 2 was used to prepare the final binder. From the above mentioned AOL resin a binder was formulated by addition of 270 kg polyethylene glycol 200 and 281 kg of a 31% solution of Primid XL-552 in water. Amount of undiluted silane dosed: 7,2 L/h (divided on 3 spinners)

Amount of cooling water on each spinner: 600 L/h

Wheels on the spinners to dose the cooling water w. silane: second, third and fourth wheel, as shown with numerals #5, #6 and #7 in Figure 6. Amount of silane: 0,4% based on the total flow of water+silane on the spinners (similar to normal dosage of silane in normal manners).

Test methods

The test methods used in the examples are as follows:

Compression stress at 10% deformation, σ 10% , has been determined according to DS/EN 826:2013 Determination of compression behaviour. At least 3 test specimens in 300 x 300 mm in full product thickness (for one result) has been measured after grinding of the surface.

Delamination strength, σ mt, has been determined according to DS/EN 1607: 2013. At least 3 test specimens in 300 x 300 mm in full product thickness for one result have been measured.

Delamination strength has further been determined for test specimens after exposure to accelerated ageing for evaluation of the ageing persistence, where two different methods have been applied:

Method 1 : Test specimens exposed to heat-moisture action for 7, 14 and 28 days at (70 ± 2) °C and (95 ± 5) % relative humidity in climatic chamber. (Nordtest method NT Build 434: 1995.05)

Method 2: Test specimens exposed to heat-moisture action for 15 minutes at (121 ± 2) °C and (95 ± 5) % relative humidity in pressure boiler.

For testing, five similar test specimens of dimensions 300 x 300 mm with full product thickness are cut out of the same slab, and the tensile strength without pre-treatment is measured for one of the test specimens. The other test specimens are exposed to accelerated ageing, according to method 1. In total, three test specimens are exposed to accelerated ageing: one for 7 days, one for 14 days, one for 28 days of treatment. After the final pre-treatment, the measurements to determine the ageing resistance are performed for each test specimen.

Dimensions of products and test specimens has been performed according to the relevant test methods, DS/EN822:2013, Determination of length and width, and DS/EN823:2013, Determination of thickness.

Short term water absorption has been determined according to DS EN 1609:2013, method A, using 4 individual test specimens in 200 x 200 mm in full product thickness to get one result.

Determination of binder content is performed according to DS/EN 13820:2003 Determination of organic content, where the binder content is defined as the quantity of organic material burnt away at a given temperature, here using (590 ± 20°C) for at least 10 min or more until constant mass. Determination of ignition loss consists of at least 10 g wool corresponding to 8-20 cut-outs (minimum 8 cut-outs) performed evenly distributed over the test specimen using a cork borer ensuring to comprise an entire product thickness.




 
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