Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
COHERENT COMPOSITE
Document Type and Number:
WIPO Patent Application WO/2017/194720
Kind Code:
A1
Abstract:
The invention provides a coherent composite comprising a substrate bound by a binder, wherein the substrate comprises fibres, and wherein the binder results from curing a binder composition that comprises at least one hydrocolloid.

Inventors:
HJELMGAARD, Thomas (Kovangen 119B, 3480 Fredensborg, 3480, DK)
CHAPELLE, Lucie (Øster Søgade 106, 5.th, 2100 København Ø, 2100, DK)
Application Number:
EP2017/061414
Publication Date:
November 16, 2017
Filing Date:
May 11, 2017
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
ROCKWOOL INTERNATIONAL A/S (Hovedgaden 584, Hedehusene, DK-2640, DK)
International Classes:
C03C25/10; C03C25/26; D04H1/64; D04H3/002; D04H3/005; E04B1/74
Attorney, Agent or Firm:
SAMUELS, Lucy Alice (The Broadgate Tower, 20 Primrose Street, London EC2A 2ES, EC2A 2ES, GB)
Download PDF:
Claims:
CLAIMS

1. A coherent composite comprising a substrate bound by a binder,

wherein the substrate comprises fibres, and

wherein the binder results from curing a binder composition that comprises at least one hydrocolloid.

2. A coherent composite according to claim 1 , wherein the binder

composition further comprises at least one phenol and/or quinone containing compound.

3. A coherent composite according to claim 1 or 2, wherein the fibres

comprise natural fibres. 4. A coherent composite according to claim 3, wherein the natural fibres are selected from animal fibres, such as sheep's wool, or plant fibres, such as wood wool, cellulosic fibres, cotton fibres, straw, hemp, flax.

5. A coherent composite according to claim 1 or 2, wherein the fibres

comprise synthetic fibres.

6. A coherent composite according to claim 5, wherein the synthetic fibres comprise inorganic fibres. 7. A coherent composite according to claim 6, wherein the synthetic

inorganic fibres are not mineral wool.

8. A coherent composite according to claim 5, wherein the synthetic fibres comprise organic fibres.

9. A coherent composite according to claim 5, wherein the synthetic fibres are selected from aramid fibres, polyacrylonitrile (PAN) fibres, carbon fibres, polyester fibres and polyamide fibres.

10. A coherent composite according to any one of the preceding claims, wherein the substrate further comprises a particulate material.

11. A coherent composite according to claim 10, wherein the particulate material comprises one or more of aerogel, cellulosic material, microspheres, perlite, zeolite, xonolite and vermiculite.

12. A coherent composite according to any one of the preceding claims, wherein the weight % binder solids in the composite is from 0.1 to 50.0 %, such as 0.3 to 36.0 %, such as 0.5 to 24.0 %, such as 0.7 to 16.0 %, such as 1.4 to 12.0 %, such as 2.0 to 8.0 % based on the weight of the composite.

13. A coherent composite according to any one of the preceding claims, wherein the composite has a density of from 10 to 1200 kg/m3, such as from 15 to 100 kg/m3, from 80 to 150 kg/m3, or above 400 kg/m3, such as 400 to 900 kg/m3.

14. A coherent composite according to any one of the preceding claims, wherein the composite has a thickness of from 5 to 500 mm, such as from 5 to 20 mm, or 40 to 100 mm, or 200 to 400 mm.

15. A coherent composite according to any one of the preceding claims, wherein the composite is in the form of a rigid panel.

16. A coherent composite according to any one of the preceding claims, wherein the composite is in the form of a pipe section.

17. A coherent composite according to any one of the preceding claims, wherein the at least one hydrocolloid is selected from the group consisting of gelatine, pectin, starch, alginate, agar agar, carrageenan, gellan gum, guar gum, gum arabic, locust bean gum, xanthan gum, cellulose derivatives such as carboxymethylcellulose, arabinoxylan, cellulose, curdlan, β-glucan.

18. A coherent composite according to any one of the preceding claims, wherein the at least one hydrocolloid is a polyelectrolytic hydrocolloid. 19. A coherent composite according to any one of the preceding claims, wherein the binder results from the curing of a binder composition in which the at least one hydrocolloid is selected from the group consisting of gelatin, pectin, alginate, carrageenan, gum arabic, xanthan gum, cellulose derivatives such as carboxymethylcellulose.

20. A coherent composite according to any one of the preceding claims, wherein the binder results from the curing of a binder composition comprising at least two hydrocolloids, wherein one hydrocolloid is gelatine and the at least one other hydrocolloid is selected from the group consisting of pectin, starch, alginate, agar agar, carrageenan, gellan gum, guar gum, gum arabic, locust bean gum, xanthan gum, cellulose derivatives such as carboxymethylcellulose, arabinoxylan, cellulose, curdlan, β-glucan. 21. A coherent composite according to any one of the preceding claims, wherein the binder results from the curing of a binder composition in which the gelatine is present in an amount of 10 to 95 wt.-%, such as 20 to 80 wt.-%, such as 30 to 70 wt.-%, such as 40 to 60 wt.-%, based on the weight of the hydrocolloids.

22. A coherent composite according to claim 20 or 21 , wherein the binder results from the curing of a binder composition in which the one hydrocolloid and the at least other hydrocolloid have complementary charges.

23. A coherent composite according to any one of the preceding claims, wherein the binder results from the curing of a binder composition capable of curing at a temperature of less than 95 °C, such as 5-95 °C, such as 10-80 °C, such as 20-60 °C, such as 40-50 °C.

24. A coherent composite according to any one of the preceding claims, wherein the binder results from the curing of a binder composition which is not a thermoset binder composition. 25. A coherent composite according to any one of the preceding claims,

wherein the binder results from a binder composition which does not contain a poly(meth)acrylic acid, a salt of a poly(meth)acrylic acid or an ester of a poly(meth)acrylic acid. 26. A coherent composite according to any one of the preceding claims,

wherein the binder results from the curing of a binder composition comprising at least one hydrocolloid which is a biopolymer or modified biopolymer. 27. A coherent composite according to any one of the preceding claims, wherein the binder results from the curing of a binder composition comprising proteins from animal sources, including collagen, gelatine, and hydrolysed gelatine, and the binder composition further comprises at least one phenol and/or quinone containing compound, such as tannin selected from one or more components from the group consisting of tannic acid, condensed tannins (proanthocyanidins), hydrolysable tannins, gallotannins, ellagitannins, complex tannins, and/or tannin originating from one or more of oak, chestnut, staghorn sumac and fringe cups.

28. A coherent composite according to any one of the preceding claims, wherein the binder results from the curing of a binder composition comprising gelatine, and the binder composition further comprises a tannin selected from one or more components from the group consisting of tannic acid, condensed tannins (proanthocyanidins), hydrolysable tannins, gallotannins, ellagitannins, complex tannins, and/or tannin originating from one or more of oak, chestnut, staghorn sumac and fringe cups, preferably tannic acid.

29. A coherent composite according to any one of the preceding claims, wherein the binder results from the curing of a binder composition comprising proteins from animal sources, including collagen, gelatine, and hydrolysed gelatine, and wherein the binder composition further comprises at least one enzyme selected from the group consisting of transglutaminase (EC 2.3.2.13), protein disulfide isomerase (EC 5.3.4.1 ), thiol oxidase (EC 1 .8.3.2), polyphenol oxidase (EC 1 .14.18.1 ), in particular catechol oxidase, tyrosine oxidase, and phenoloxidase, lysyl oxidase (EC 1.4.3.13), and peroxidase (EC 1 .1 1.1.7).

30. A coherent composite according to any one of the preceding claims, wherein the binder results from the curing of a binder composition comprising gelatine, and wherein the binder composition further comprises an enzyme which is transglutaminase (EC 2.3.2.13.

31 . A coherent composite according to any one of the preceding claims, wherein the binder results from the curing of a binder composition which is formaldehyde-free. 32. A coherent composite according to any one of the preceding claims, wherein the binder results from a binder composition consisting essentially of at least one hydrocolloid; optionally at least one oil; optionally at least one pH-adjuster; - optionally at least one crosslinker; optionally at least one anti-fouling agent; optionally at least one anti-swelling agent; water.

33. A coherent composite according to any one of the preceding claims, wherein the binder is not crosslinked.

34. A coherent composite according to any one of claims 1 to 32, wherein the binder is crosslinked.

35. Use of the coherent composite of any one of claims 1 to 34 as a thermal insulation material, a sound absorption material, or a construction material.

36. A method for producing a coherent composite which comprises the steps of contacting fibers with a binder composition comprising at least one hydrocolloid, and curing the binder composition.

37. A method of producing a coherent composite comprising the steps of blending a substrate with a binder composition to form a mixture, and curing the binder composition to form a binder and thereby forming the coherent composite;

wherein the binder composition comprises at least one hydrocolloid, and wherein the substrate comprises fibres.

38. Method according to claim 37, wherein the step of blending the substrate with a binder composition comprises mixing the substrate with the binder composition to form a homogeneous mixture.

39. Method according to claim 36 or 37, wherein the weight % binder solids in the final composite is from 0.1 to 50.0 %, such as 0.3 to 36.0 %, such as 0.5 to 24.0 %, such as 0.7 to 16.0 %, such as 1.4 to 12.0 %, such as 2.0 to 8.0 % based on the weight of the composite.

40. Method according to claim 36 or 37, wherein the weight % of binder composition in the mixture, prior to curing, is from 0.1 to 50.0 %, such as

0.3 to 36.0 %, such as 0.5 to 24.0 %, such as 0.7 to 16.0 %, such as 1.4 to 12.0 %, such as 2.0 to 8.0 % based on the weight of the mixture.

41. A method according to claim 36 or 37, wherein the curing is carried out at a temperature of from 5 to 95 °C, preferably from 10 to 80 °C, more preferably from 20 to 60 °C, more preferably from 40 to 50 °C.

42. A method according to any of claims 36 to 40, wherein the hydrocolloid has any of the features of claims 17 to 19 and the binder composition has any of the features of claims 20 to 33.

Description:
COHERENT COMPOSITE

FIELD OF THE INVENTION

The invention relates to coherent composites bonded with a binder derived from natural products and methods of making said composites.

BACKGROUND

Known coherent composites comprise, at the most basic formulation, a binder and a filler (non-binder component). In the past, the binder resins of choice have been phenol-formaldehyde resins which 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.

Since some of the starting materials used in the production of these binders are rather expensive chemicals, 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 is that at least the majority of the starting materials used for the productions of these binders stem from fossil fuels. There is an on-going 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 coherent composites which are at least partly produced from renewable materials. A further effect in connection with previously known aqueous binder compositions 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 for coherent composites with a reduced content of corrosive and/or harmful materials.

A yet further effect in connection with previously known aqueous binder compositions is that these binders are conventionally associated with extensive curing equipment for curing the binder. The curing equipment is conventionally an oven operating at temperatures far above 100 °C such as around 200 °C.

The oven, in the case of mineral fibre composites, can be several meters long to accommodate the web that is continuously fed into the oven and to ensure that the web is fully cured when leaving the oven. Such oven equipment is associated with extensive energy consumption.

In addition, the use of oven-cured binders precludes the use of various fillers that melt or otherwise become unsuitable for use at the temperature of the oven.

Some inorganic binders such as waterglass (alkali metal silicate solution) are able to cure at ambient temperature. However, waterglass binder is not suitable for all applications and still uses a considerable amount of energy during manufacture. The reference C. Pena, K. de la Caba, A. Eceiza, R. Ruseckaite, I. Mondragon in Biores. Technol. 2010, 101 , 6836-6842 is concerned with the replacement of nonbiodegradable plastic films by renewable raw materials from plants and wastes of meat industry. In this connection, this reference describes the use of hydrolysable chestnut-tree tannin for modification of a gelatin in order to form films. The reference does not describe binders, in particular not binders for mineral wool or other non- binder components for coherent composites.

WO2010/125163A1 (Dynea Oy) describes a composite material comprising filler and a resin comprising proteinaceous material cross-linked by enzymes. The composite material is described as useful for making foundry moulds or wood panels. These enzymes can be fragile to work with and have limited versatility.

Accordingly, it was an object of the present invention to provide a binder composition which is particularly suitable for bonding the non-binder component of a coherent composite, uses renewable materials as starting materials, reduces or eliminates corrosive and/or harmful materials.

Further, it was an object of the present invention to provide a binder composition which does not require high temperature for curing and therefore eliminates need of high temperature to be applied in the production of a product bonded with the binder composition.

SUMMARY

In a first aspect the invention provides a coherent composite comprising a substrate bound by a binder,

wherein the substrate comprises fibres, and

wherein the binder results from curing a binder composition that comprises a hydrocolloid.

Preferably, the binder composition further comprises at least one phenol and/or quinone containing compound. In a second aspect the invention provides a method of producing a coherent composite comprising the steps of

• blending a substrate with a binder composition, and

• curing the binder composition to form a binder and thereby forming the

coherent composite;

wherein the binder composition comprises a hydrocolloid, and wherein the substrate comprises fibres.

In the method the cured binder composition forms a binder that bonds the substrate fibres to form the composite.

In a third aspect the invention further provides use of the coherent composite of the invention as a thermal insulation material, a sound absorption material, or a

construction material. Compared to composites of WO2010/125163A1 , the coherent composites of the present invention are more versatile and can to a higher degree be tailored for the specific process, due to the different binder used.

The coherent composite according to the present invention has the surprising advantage that it can be produced by using a very simple binder which requires as little as only one component, namely a hydrocolloid. The coherent composite according to the present invention is therefore produced from natural and non-toxic components and is therefore safe to work with. At the same time, the coherent composite according to the present invention is produced from a binder based on renewable resources.

A further advantage is the possibility of curing at ambient temperature or in the vicinity of ambient temperature. This not only leads to savings of energy consumption and less complexity of the machinery required but also decreases the likelihood of uncured binder spots, which can occur during thermal curing of conventional binders.

Yet another advantage is the absence of emissions during curing, in particular the absence of VOC emissions. A surprising advantage of embodiments of coherent composites according to the present invention is that they show self-healing properties. After being exposed to very harsh conditions when some substrates lose a part of their strength, the coherent composites according to the present invention can regain a part of the original strength. This is in contrast to conventional coherent composites for which the loss of strength after being exposed to harsh environmental conditions is irreversible. While not wanting to be bound to any particular theory, the present inventors believe that this surprising property in coherent composites according to the present invention is due to the complex nature of the bonds formed in the network of the protein crosslinked by the phenol and/or quinone containing compound which also includes quaternary structures and hydrogen bonds and allows bonds in the network to be established after returning to normal environmental conditions. For an insulation product, which when e.g. used as a roof insulation can be exposed to very high temperatures in the summer, this is an important advantage for the long term stability of the product.

A further advantage of the coherent composites produced with the binder according to the present invention is that they may be shaped as desired after application of the binder but prior to curing. This opens the possibility for making

tailor-made products, like pipe sections.

DETAILED DESCRIPTION

Substrate

The coherent composite of the invention comprises, in addition to a binder, fibres.

Natural fibres, synthetic fibres, or a combination of natural and synthetic fibres may be used in the invention.

Suitable natural fibres may be selected from animal fibres, such as sheep's wool, and plant fibres, such as wood wool, cellulosic fibres, cotton fibres, straw, hemp, flax. The natural fibres preferably do not include asbestos. Suitable synthetic fibres may be inorganic, organic, or a mixture of organic and inorganic fibres.

Suitable synthetic fibres may be selected from aramid fibres, polyacrylonitrile (PAN) fibres, carbon fibres, polyester fibres and polyamide fibres. In some embodiments, the synthetic inorganic fibres are not mineral wool.

However, the fibres may comprise or consist of mineral fibres. These will normally be man-made vitreous fibres (MMVF) such as, e.g., glass fibres, ceramic fibres, basalt fibres, slag wool, mineral wool and stone wool.

Optionally the composite may comprise a particulate material in addition to fibres. Suitable particulate materials may be one or more selected from aerogel, cellulosic material, microspheres, perlite, zeolite, xonolite and vermiculite.

Some fibres and particulates, especially natural materials and synthetic organic fibres, can be sensitive to heat, for example some of these materials have a relatively low melting temperature compared to inorganic fibres. The coherent composite of the invention has the benefit compared to conventional coherent composites that it is still possible to utilise heat-sensitive components, because the binder does not require heat for curing.

Binder component Preferably, the binder composition is an aqueous composition. Hvdrocolloid

Hydrocolloids are hydrophilic polymers, of vegetable, animal, microbial or synthetic origin, that generally contain many hydroxyl groups and may be polyelectrolytes. They are widely used to control the functional properties of aqueous foodstuffs.

Hydrocolloids may be proteins or polysaccharides and are fully or partially soluble in water and are used principally to increase the viscosity of the continuous phase (aqueous phase) i.e. as gelling agent or thickener. They can also be used as emulsifiers since their stabilizing effect on emulsions derives from an increase in viscosity of the aqueous phase.

A hydrocolloid usually consists of mixtures of similar, but not identical molecules and arising from different sources and methods of preparation. The thermal processing and for example, salt content, pH and temperature all affect the physical properties they exhibit. Descriptions of hydrocolloids often present idealised structures but since they are natural products (or derivatives) with structures determined by for example stochastic enzymatic action, not laid down exactly by the genetic code, the structure may vary from the idealised structure.

Many hydrocolloids are polyelectrolytes (for example alginate, gelatine, carboxymethylcellulose and xanthan gum). Polyelectrolytes are polymers where a significant number of the repeating units bear an electrolyte group. Polycations and polyanions are polyelectrolytes. These groups dissociate in aqueous solutions (water), making the polymers charged. Polyelectrolyte properties are thus similar to both electrolytes (salts) and polymers (high molecular weight compounds) and are sometimes called polysalts.

The charged groups ensure strong hydration, particularly on a per-molecule basis. The presence of counterions and co-ions (ions with the same charge as the polyelectrolyte) introduce complex behavior that is ion-specific. A proportion of the counterions remain tightly associated with the polyelectrolyte, being trapped in its electrostatic field and so reducing their activity and mobility.

In one embodiment the binder composition comprise one or more counter-ion(s) selected from the group of Mg2+, Ca2+, Sr2+, Ba2+.

Another property of a polyelectrolyte is the high linear charge density (number of charged groups per unit length).

Generally neutral hydrocolloids are less soluble whereas polyelectrolytes are more soluble.

Many hydrocolloids also gel. Gels are liquid-water-containing networks showing solidlike behavior with characteristic strength, dependent on their concentration, and hardness and brittleness dependent on the structure of the hydrocolloid(s) present. Hydrogels are hydrophilic crosslinked polymers that are capable of swelling to absorb and hold vast amounts of water. They are particularly known from their use in sanitary products. Commonly used materials make use of polyacrylates, but hydrogels may be made by crosslinking soluble hydrocolloids to make an insoluble but elastic and hydrophilic polymer.

Examples of hydrocolloids comprise: Agar agar, Alginate, Arabinoxylan, Carrageenan, Carboxymethylcellulose, Cellulose, Curdlan, Gelatine, Gellan, β-Glucan, Guar gum, Gum arabic, Locust bean gum, Pectin, Starch, Xanthan gum.

In one embodiment, the at least one hydrocolloid is selected from the group consisting of gelatine, pectin, starch, alginate, agar agar, carrageenan, gellan gum, guar gum, gum arabic, locust bean gum, xanthan gum, cellulose derivatives such as carboxymethylcellulose, arabinoxylan, cellulose, curdlan, β-glucan. In one embodiment, the at least one hydrocolloid is a polyelectrolytic hydrocolloid.

In one embodiment, the at least one hydrocolloid is selected from the group consisting of gelatine, pectin, alginate, carrageenan, gum arabic, xanthan gum, cellulose derivatives such as carboxymethylcellulose.

In one embodiment, the at least one hydrocolloid is a gel former.

In one embodiment, the at least one hydrocolloid is used in form of a salt, such as a salt of Na+, K+, NH4+, Mg2+, Ca2+, Sr2+, Ba2+.

Gelatine

Gelatine is derived from chemical degradation of collagen. Gelatine is water soluble and has a molecular weight of 10.000 to 500.000 g/mol, such as 30.000 to 300.000 g/mol dependent on the grade of hydrolysis. Gelatine is a widely used food product and it is therefore generally accepted that this compound is totally non-toxic and therefore no precautions are to be taken when handling gelatine.

Gelatine is a heterogeneous mixture of single or multi-stranded polypeptides, typically showing helix structures. Specifically, the triple helix of type I collagen extracted from skin and bones, as a source for gelatine, is composed of two a1 (l) and one a2(l) chains.

Gelatine solutions may undergo coil-helix transitions.

A type gelatins are produced by acidic treatment. B type gelatines are produced by basic treatment.

Chemical cross-links may be introduced to gelatine. In one embodiment, transglutaminase is used to link lysine to glutamine residues; in one embodiment, glutaraldehyde is used to link lysine to lysine, in one embodiment, tannins are used to link lysine residues.

The gelatine can also be further hydrolysed to smaller fragments of down to 3000 g/mol.

On cooling a gelatine solution, collagen like helices may be formed.

Other hydrocolloids may also comprise helix structures such as collagen like helices. Gelatine may form helix structures.

In one embodiment, the cured binder comprising hydrocolloid comprises helix structures. In one embodiment, the at least one hydrocolloid is a low strength gelatine, such as a gelatine having a gel strength of 30 to 125 Bloom.

In one embodiment, the at least one hydrocolloid is a medium strength gelatine, such as a gelatine having a gel strength of 125 to 180 Bloom.

In one embodiment, the at least one hydrocolloid is a high strength gelatine, such as a gelatine having a gel strength of 180 to 300 Bloom. In a preferred embodiment, the gelatine is preferably originating from one or more sources from the group consisting of mammal, bird species, such as from cow, pig, horse, fowl, and/or from scales, skin of fish. In one embodiment, urea may be added to the binder compositions according to the present invention. The inventors have found that the addition of even small amounts of urea causes denaturation of the gelatin, which can slow down the gelling, which might be desired in some embodiments. The addition of urea might also lead to a softening of the product.

The inventors have found that the carboxylic acid groups in gelatins interact strongly with trivalent and tetravalent ions, for example aluminium salts. This is especially true for type B gelatines which contain more carboxylic acid groups than type A gelatines. The present inventors have found that in some embodiments, curing/drying of binder compositions according to the present invention including gelatin should not start off at very high temperatures.

The inventors have found that starting the curing at low temperatures has led to stronger products. Without being bound to any particular theory, it is assumed by the inventors that starting curing at high temperatures may lead to an impenetrable outer shell which hinders water from underneath to get out.

Surprisingly, the binders according to the present invention including gelatines are very heat resistant. The present inventors have found that in some embodiments the cured binders can sustain temperatures up to 300°C without degradation.

Pectin Pectin is a heterogeneous grouping of acidic structural polysaccharides, found in fruit and vegetables which form acid-stable gels.

Generally, pectins do not possess exact structures, instead it may contain up to 17 different monosaccharides and over 20 types of different linkages. D-galacturonic acid residues form most of the molecules.

Gel strength increases with increasing Ca2+ concentration but reduces with temperature and acidity increase (pH < 3).

Pectin may form helix structures.

The gelling ability of the di-cations is similar to that found with alginates (Mg2+ is much less than for Ca2+, Sr2+ being less than for Ba2+).

Alginate

Alginates are scaffolding polysaccharides produced by brown seaweeds. Alginates are linear unbranched polymers containing β-(1 ,4)-linked D-mannuronic acid (M) and a-(1 ,4)-linked L-guluronic acid (G) residues. Alginate may also be a bacterial alginate, such as which are additionally O-acetylated. Alginates are not random copolymers but, according to the source algae, consist of blocks of similar and strictly alternating residues (that is, MM MM MM, GGGGGG and GMGMGMGM), each of which have different conformational preferences and behavior. Alginates may be prepared with a wide range of average molecular weights (50 - 100000 residues). The free carboxylic acids have a water molecule H30+ firmly hydrogen bound to carboxylate. Ca2+ ions can replace this hydrogen bonding, zipping guluronate, but not mannuronate, chains together stoichiometrically in a so-called egg-box like conformation. Recombinant epimerases with different specificities may be used to produce designer alginates.

Alginate may form helix structures. Carrageenan

Carrageenan is a collective term for scaffolding polysaccharides prepared by alkaline extraction (and modification) from red seaweed. Carrageenans are linear polymers of about 25,000 galactose derivatives with regular but imprecise structures, dependent on the source and extraction conditions.

K-carrageenan (kappa-carrageenan) is produced by alkaline elimination from μ- carrageenan isolated mostly from the tropical seaweed Kappaphycus alvarezii (also known as Eucheuma cottonii). i-carrageenan (iota-carrageenan) is produced by alkaline elimination from v- carrageenan isolated mostly from the Philippines seaweed Eucheuma denticulatum (also called Spinosum). λ-carrageenan (lambda-carrageenan) (isolated mainly from Gigartina pistillata or Chondrus crispus) is converted into θ-carrageenan (theta-carrageenan) by alkaline elimination, but at a much slower rate than causes the production of i-carrageenan and κ-carrageenan.

The strongest gels of κ-carrageenan are formed with K+ rather than Li+, Na+, Mg2+, Ca2+, or Sr2+. All carrageenans may form helix structures.

Gum arabic

Gum arabic is a complex and variable mixture of arabinogalactan oligosaccharides, polysaccharides and glycoproteins. Gum arabic consists of a mixture of lower relative molecular mass polysaccharide and higher molecular weight hydroxyproline-rich glycoprotein with a wide variability.

Gum arabic has a simultaneous presence of hydrophilic carbohydrate and hydrophobic protein.

Xanthan gum

Xanthan gum is a microbial desiccation-resistant polymer prepared e.g. by aerobic submerged fermentation from Xanthomonas campestris. Xanthan gum is an anionic polyelectrolyte with a 3-(1 ,4)-D-glucopyranose glucan (as cellulose) backbone with side chains of -(3,1 )-a-linked D-mannopyranose-(2,1 )-3-D- glucuronic acid-(4,1 )-3-D-mannopyranose on alternating residues.

Xanthan gums natural state has been proposed to be bimolecular antiparallel double helices. A conversion between the ordered double helical conformation and the single more-flexible extended chain may take place at between 40 °C - 80 °C. Xanthan gums may form helix structures.

Xanthan gums may contain cellulose.

Cellulose derivatives An example of a cellulose derivative is carboxymethylcellulose.

Carboxymethylcellulose (CMC) is a chemically modified derivative of cellulose formed by its reaction with alkali and chloroacetic acid. The CMC structure is based on the β-(1 ,4)-D-glucopyranose polymer of cellulose. Different preparations may have different degrees of substitution, but it is generally in the range 0.6 - 0.95 derivatives per monomer unit.

Agar agar

Agar agar is a scaffolding polysaccharide prepared from the same family of red seaweeds (Rhodophycae) as the carrageenans. It is commercially obtained from species of Gelidium and Gracilariae. Agar agar consists of a mixture of agarose and agaropectin. Agarose is a linear polymer, of relative molecular mass (molecular weight) about 120,000, based on the - (1 ,3)-3-D-galactopyranose-(1 ,4)-3,6-anhydro-a-L-galactopyranose unit.

Agaropectin is a heterogeneous mixture of smaller molecules that occur in lesser amounts. Agar agar may form helix structures.

Arabinoxylan

Arabinoxylans are naturally found in the bran of grasses (Graminiae).

Arabinoxylans consist of a-L-arabinofuranose residues attached as branch-points to β-(1 ,4)-linked D-xylopyranose polymeric backbone chains.

Arabinoxylan may form helix structures. Cellulose Cellulose is a scaffolding polysaccharide found in plants as microfibrils (2-20 nm diameter and 100 - 40 000 nm long). Cellulose is mostly prepared from wood pulp. Cellulose is also produced in a highly hydrated form by some bacteria (for example, Acetobacter xylinum). Cellulose is a linear polymer of β-(1 ,4)-D-glucopyranose units in 4C1 conformation. There are four crystalline forms, Ια, Ιβ, II and III.

Cellulose derivatives may be methyl cellulose, hydroxypropyl methylcellulose, hydroxyethyl methylcellulose, hydroxyethyl cellulose, hydroxypropyl cellulose.

Curdlan

Curdlan is a polymer prepared commercially from a mutant strain of Alcaligenes faecalis var. myxogenes. Curdlan (curdlan gum) is a moderate relative molecular mass, unbranched linear 1 ,3 β-D glucan with no side-chains.

Curdlan may form helix structures.

Curdlan gum is insoluble in cold water but aqueous suspensions plasticize and briefly dissolve before producing reversible gels on heating to around 55 °C. Heating at higher temperatures produces more resilient irreversible gels, which then remain on cooling.

Scleroglucan is also a 1 ,3 β-D glucan but has additional 1 ,6 β-links that confer solubility under ambient conditions.

Gellan

Gellan gum is a linear tetrasaccharide 4)-L-rhamnopyranosyl-(a-1 ,3)-D- glucopyranosyl-(3-1 ,4)-D-glucuronopyranosyl-(3-1 ,4)-D-glucopyranosyl-(3-1 , with 0(2) L-glyceryl and 0(6) acetyl substituents on the 3-linked glucose.

Gellan may form helix structures. B-Glucan β-Glucans occur in the bran of grasses (Gramineae). β-Glucans consist of linear unbranched polysaccharides of linked β-(1 ,3)- and β-(1 ,4)- D-glucopyranose units in a non-repeating but non-random order.

Guar gum

Guar gum (also called guaran) is a reserve polysaccharide (seed flour) extracted from the seed of the leguminous shrub Cyamopsis tetragonoloba.

Guar gum is a galactomannana similar to locust bean gum consisting of a (1 ,4)-linked β-D-mannopyranose backbone with branch points from their 6-positions linked to a-D- galactose (that is, 1 ,6-linked-a-D-galactopyranose).

Guar gum is made up of non-ionic polydisperse rod-shaped polymer.

Unlike locust bean gum, it does not form gels. Locust bean gum Locust bean gum (also called Carob bean gum and Carubin) is a reserve polysaccharide (seed flour) extracted from the seed (kernels) of the carob tree (Ceratonia siliqua).

Locust bean gum is a galactomannana similar to guar gum consisting of a (1 ,4)-linked β-D-mannopyranose backbone with branch points from their 6-positions linked to a-D- galactose (that is, 1 ,6-linked a-D-galactopyranose). Locust bean gum is polydisperse consisting of non-ionic molecules.

Starch

Starch consists of two types of molecules, amylose (normally 20-30%) and amylopectin (normally 70-80%). Both consist of polymers of a-D-glucose units in the 4C1 conformation. In amylose these are linked -(1 ,4)-, with the ring oxygen atoms all on the same side, whereas in amylopectin about one residue in every twenty or so is also linked -(1 ,6)- forming branch-points. The relative proportions of amylose to amylopectin and -(1 ,6)- branch-points both depend on the source of the starch. The starch may derive from the source of corn (maize), wheat, potato, tapioca and rice. Amylopectin (without amylose) can be isolated from 'waxy' maize starch whereas amylose (without amylopectin) is best isolated after specifically hydrolyzing the amylopectin with pullulanase. Amylose may form helix structures.

In one embodiment, the at least one hydrocolloid is a functional derivative of starch such as cross-linked, oxidized, acetylated, hydroxypropylated and partially hydrolyzed starch.

In a preferred embodiment, the binder composition comprises at least two polyelectrolytic hydrocolloids, wherein one hydrocolloid is gelatine and the at least one other hydrocolloid is selected from the group consisting of pectin, alginate, carrageenan, gum arabic, xanthan gum, cellulose derivatives such as carboxymethylcellulose. In one embodiment, the binder composition comprises at least two hydrocolloids, wherein one hydrocolloid is gelatine and the at least other hydrocolloid is pectin. In one embodiment, the binder composition comprises at least two hydrocolloids, wherein one hydrocolloid is gelatine and the at least other hydrocolloid is alginate.

In one embodiment, the binder composition comprises at least two hydrocolloids, wherein one hydrocolloid is gelatine and the at least other hydrocolloid is carboxymethylcellulose.

In a preferred embodiment, the binder composition according to the present invention comprises at least two hydrocolloids, wherein one hydrocolloid is gelatine and wherein the gelatine is present in the aqueous binder composition in an amount of 10 to 95 wt.-%, such as 20 to 80 wt.-%, such as 30 to 70 wt.-%, such as 40 to 60 wt.-%, based on the weight of the hydrocolloids.

In one embodiment, the binder composition comprises at least two hydrocolloids, wherein the one hydrocolloid and the at least other hydrocolloid have complementary charges.

In one embodiment, the one hydrocolloid is one or more of gelatine or gum arabic having complementary charges from one or more hydrocolloid(s) selected from the group of pectin, alginate, carrageenan, xanthan gum or carboxymethylcellulose.

In one embodiment, the binder composition is capable of curing at a temperature of not more than 95 °C, such as 5-95 °C, such as 10-80 °C, such as 20-60 °C, such as 40-50 °C. In one embodiment, the aqueous binder composition according to the present invention is not a thermoset binder.

A thermosetting composition is in a soft solid or viscous liquid state, preferably comprising a prepolymer, preferably comprising a resin, that changes irreversibly into an infusible, insoluble polymer network by curing. Curing is typically induced by the action of heat, whereby typically temperatures above 95°C are needed.

A cured thermosetting resin is called a thermoset or a thermosetting plastic/ polymer - when used as the bulk material in a polymer composite, they are referred to as the thermoset polymer matrix. In one embodiment, the aqueous binder composition according to the present invention does not contain a poly(meth)acrylic acid, a salt of a poly(meth)acrylic acid or an ester of a poly(meth)acrylic acid. In one embodiment, the at least one hydrocolloid is a biopolymer or modified biopolymer.

Biopolymers are polymers produced by living organisms. Biopolymers may contain monomeric units that are covalently bonded to form larger structures.

There are three main classes of biopolymers, classified according to the monomeric units used and the structure of the biopolymer formed: Polynucleotides (RNA and DNA), which are long polymers composed of 13 or more nucleotide monomers; Polypeptides, such as proteins, which are polymers of amino acids; Polysaccharides, such as linearly bonded polymeric carbohydrate structures.

Polysaccharides may be linear or branched; they are typically joined with glycosidic bonds. In addition, many saccharide units can undergo various chemical modifications, and may form parts of other molecules, such as glycoproteins.

In one embodiment, the at least one hydrocolloid is a biopolymer or modified biopolymer with a polydispersity index regarding molecular mass distribution of 1 , such as 0.9 to 1. In one embodiment, the binder composition comprises proteins from animal sources, including collagen, gelatine, and hydrolysed gelatine, and the binder composition further comprises at least one phenol and/or quinone containing compound, such as tannin selected from one or more components from the group consisting of tannic acid, condensed tannins (proanthocyanidins), hydrolysable tannins, gallotannins, ellagitannins, complex tannins, and/or tannin originating from one or more of oak, chestnut, staghorn sumac and fringe cups.

In one embodiment, the binder composition comprises proteins from animal sources, including collagen, gelatine, and hydrolysed gelatine, and wherein the binder composition further comprises at least one enzyme selected from the group consisting of transglutaminase (EC 2.3.2.13), protein disulfide isomerase (EC 5.3.4.1 ), thiol oxidase (EC 1.8.3.2), polyphenol oxidase (EC 1.14.18.1 ), in particular catechol oxidase, tyrosine oxidase, and phenoloxidase, lysyl oxidase (EC 1.4.3.13), and peroxidase (EC 1.1 1.1.7).

In one embodiment, the aqueous binder composition is formaldehyde-free.

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

In one embodiment, the binder composition according to the present invention is consisting essentially of:

at least one hydrocolloid;

optionally at least one oil;

optionally at least one pH-adjuster;

optionally at least one crosslinker;

- optionally at least one anti-fouling agent;

optionally at least one anti-swelling agent;

water.

In one embodiment, the at least one oil is a non-emulsified hydrocarbon oil.

In one embodiment, the at least one oil is an emulsified hydrocarbon oil.

In one embodiment, the at least one oil is a plant-based oil. In one embodiment, the at least one crosslinker is tannin selected from one or more components from the group consisting of tannic acid, condensed tannins (proanthocyanidins), hydrolysable tannins, gallotannins, ellagitannins, complex tannins, and/or tannin originating from one or more of oak, chestnut, staghorn sumac and fringe cups.

In one embodiment, the at least one crosslinker is an enzyme selected from the group consisting of transglutaminase (EC 2.3.2.13), protein disulfide isomerase (EC 5.3.4.1 ), thiol oxidase (EC 1.8.3.2), polyphenol oxidase (EC 1.14.18.1 ), in particular catechol oxidase, tyrosine oxidase, and phenoloxidase, lysyl oxidase (EC 1.4.3.13), and peroxidase (EC 1.1 1.1.7).

In one embodiment, the at least one anti-swelling agent is tannic acid and/or tannins. In one embodiment, the at least one anti-fouling agent is an antimicrobial agent.

Antimicrobial agents may be benzoic acid, propionic acid, sodium benzoate, sorbic acid, and potassium sorbate to inhibit the outgrowth of both bacterial and fungal cells. However, natural biopreservatives may be used. Chitosan is regarded as being antifungal and antibacterial. The most frequently used biopreservatives for antimicrobial are lysozyme and nisin. Common other biopreservatives that may be used are bacteriocins, such as lacticin and pediocin and antimicrobial enzymes, such as chitinase and glucose oxidase. Also, the use of the enzyme lactoperoxidase (LPS) presents antifungal and antiviral activities. Natural antimicrobial agents may also be used, such as tannins, rosemary, and garlic essential oils, oregano, lemon grass, or cinnamon oil at different concentrations.

Coherent composite The present invention is directed to a coherent composite comprising a substrate bound by a binder, wherein the substrate comprises fibres and the binder results from the curing of a binder composition comprising a hydrocolloid.

The cured binder will be dispersed throughout the coherent composite. The binder may be substantially evenly distributed within the substrate. The substrate is bound by the binder, which in this case refers to binding of discrete substrate fibres and optionally particulates, rather than an inter-substrate bond between two separate substrate elements. The substrate may be in various forms, such as a collected web or loose fibres, along with any other components such as particulates and fillers.

In one embodiment, the loss on ignition (LOI) of the coherent composite according to the present invention is within the range of 0.1 to 25.0 %, such as 0.3 to 18.0 %, such as 0.5 to 12.0 %, such as 0.7 to 8.0 % by weight.

In one embodiment, the binder is not crosslinked.

In an alternative embodiment, the binder is crosslinked.

The present invention is also directed to a coherent composite comprising fibers bound by a binder resulting from the curing of a binder composition comprising a hydrocolloid. In one embodiment, the at least one hydrocolloid is selected from the group consisting of gelatine, pectin, starch, alginate, agar agar, carrageenan, gellan gum, guar gum, gum arabic, locust bean gum, xanthan gum, cellulose derivatives such as carboxymethylcellulose, arabinoxylan, cellulose, curdlan, β-glucan. In one embodiment, the at least one hydrocolloid is a polyelectrolytic hydrocolloid.

In one embodiment, the binder results from the curing of a binder composition in which the at least one hydrocolloid is selected from the group consisting of gelatin, pectin, alginate, carrageenan, gum arabic, xanthan gum, cellulose derivatives such as carboxymethylcellulose.

In one embodiment, the binder results from the curing of a binder composition comprising at least two hydrocolloids, wherein one hydrocolloid is gelatine and the at least one other hydrocolloid is selected from the group consisting of pectin, starch, alginate, agar agar, carrageenan, gellan gum, guar gum, gum arabic, locust bean gum, xanthan gum, cellulose derivatives such as carboxymethylcellulose, arabinoxylan, cellulose, curdlan, β-glucan.

In one embodiment, the binder results from the curing of a binder composition in which the gelatine is present in an amount of 10 to 95 wt.-%, such as 20 to 80 wt.-%, such as 30 to 70 wt.-%, such as 40 to 60 wt.-%, based on the weight of the hydrocolloids.

In one embodiment, the binder results from the curing of a binder composition in which the one hydrocolloid and the at least other hydrocolloid have complementary charges.

In one embodiment, the loss on ignition (LOI) is within the range of 0.1 to 25.0 %, such as 0.3 to 18.0 %, such as 0.5 to 12.0 %, such as 0.7 to 8.0 % by weight.

In one embodiment, the binder results from the curing of a binder composition at a temperature of less than 95°C, such as 5-95°C, such as 10-80°C, such as 20-60°C, such as 40-50 °C.

In one embodiment, the binder results from the curing of a binder composition which is not a thermoset binder composition.

In one embodiment, the binder results from a binder composition which does not contain a poly(meth)acrylic acid, a salt of a poly(meth)acrylic acid or an ester of a poly(meth)acrylic acid.

In one embodiment, the binder results from the curing of a binder composition comprising at least one hydrocolloid which is a biopolymer or modified biopolymer.

In one embodiment, the binder results from the curing of a binder composition comprising proteins from animal sources, including collagen, gelatine, and hydrolysed gelatine, and the binder composition further comprises at least one phenol and/or quinone containing compound, such as tannin selected from one or more components from the group consisting of tannic acid, condensed tannins (proanthocyanidins), hydrolysable tannins, gallotannins, ellagitannins, complex tannins, and/or tannin originating from one or more of oak, chestnut, staghorn sumac and fringe cups. In one embodiment, the binder results from the curing of a binder composition comprising proteins from animal sources, including collagen, gelatine, and hydrolysed gelatine, and wherein the binder composition further comprises at least one enzyme selected from the group consisting of transglutaminase (EC 2.3.2.13), protein disulfide isomerase (EC 5.3.4.1 ), thiol oxidase (EC 1.8.3.2), polyphenol oxidase (EC 1.14.18.1 ), in particular catechol oxidase, tyrosine oxidase, and phenoloxidase, lysyl oxidase (EC 1.4.3.13), and peroxidase (EC 1.1 1.1.7). In one embodiment, the binder results from the curing of a binder composition which is formaldehyde-free.

In one embodiment, the binder results from a binder composition consisting essentially of

- at least one hydrocolloid;

optionally at least one oil;

optionally at least one pH-adjuster;

optionally at least one crosslinker;

optionally at least one anti-fouling agent;

- optionally at least one anti-swelling agent;

water.

In one embodiment, the binder is not crosslinked. In one embodiment, the binder is crosslinked. Reaction of the binder components

The present inventors have found that in some embodiments of the coherent composite according to the present invention are best to be produced when the binder is applied to the fibres under acidic conditions. Therefore, in a preferred embodiment, the binder applied to the fibres comprises a pH-adjuster, in particular in form of a pH buffer. In a preferred embodiment, the binder in its uncured state has a pH value of less than 8, such as less than 7, such as less than 6.

The present inventors have found that in some embodiments, the curing of the binder is strongly accelerated under alkaline conditions. Therefore, in one embodiment, the binder composition for fibres comprises a pH-adjuster, preferably in form of a base, such as organic base, such as amine or salts thereof, inorganic bases, such as metal hydroxide, such as KOH or NaOH, ammonia or salts thereof. In a particular preferred embodiment, the pH adjuster is an alkaline metal hydroxide, in particular NaOH.

In a preferred embodiment, the binder composition according to the present invention has a pH of 7 to 10, such as 7.5 to 9.5, such as 8 to 9.

Other additives may be components such as one or more reactive or nonreactive silicones and may be added to the binder. Preferably, the one or more reactive or nonreactive silicone is selected from the group consisting of silicone constituted of a main chain composed of organosiloxane residues, especially diphenylsiloxane residues, alkylsiloxane residues, preferably dimethylsiloxane residues, bearing at least one hydroxyl, acyl, carboxyl or anhydride, amine, epoxy or vinyl functional group capable of reacting with at least one of the constituents of the binder composition and is preferably present in an amount of 0.1 -15 weight-%, preferably from 0.1 -10 weight- %, more preferably 0.3-8 weight-%, based on the total binder mass.

In one embodiment, an oil may be added to the binder composition. In one embodiment, the at least one oil is a non-emulsified hydrocarbon oil. In one embodiment, the at least one oil is an emulsified hydrocarbon oil. In one embodiment, the at least one oil is a plant-based oil.

In one embodiment, the at least one crosslinker is tannin selected from one or more components from the group consisting of tannic acid, condensed tannins (proanthocyanidins), hydrolysable tannins, gallotannins, ellagitannins, complex tannins, and/or tannin originating from one or more of oak, chestnut, staghorn sumac and fringe cups. In one embodiment, the at least one crosslinker is an enzyme selected from the group consisting of transglutaminase (EC 2.3.2.13), protein disulfide isomerase (EC 5.3.4.1 ), thiol oxidase (EC 1.8.3.2), polyphenol oxidase (EC 1.14.18.1 ), in particular catechol oxidase, tyrosine oxidase, and phenoloxidase, lysyl oxidase (EC 1.4.3.13), and peroxidase (EC 1.1 1.1.7).

In one embodiment, the at least one anti-swelling agent is tannic acid and/or tannins. In one embodiment, the at least one anti-fouling agent is an antimicrobial agent. Antimicrobial agents may be benzoic acid, propionic acid, sodium benzoate, sorbic acid, and potassium sorbate to inhibit the outgrowth of both bacterial and fungal cells. However, natural biopreservatives may be used. Chitosan is regarded as being antifungal and antibacterial. The most frequently used biopreservatives for antimicrobial are lysozyme and nisin. Common other biopreservatives that may be used are bacteriocins, such as lacticin and pediocin and antimicrobial enzymes, such as chitinase and glucose oxidase. Also, the use of the enzyme lactoperoxidase (LPS) presents antifungal and antiviral activities. Natural antimicrobial agents may also be used, such as tannins, rosemary, and garlic essential oils, oregano, lemon grass, or cinnamon oil at different concentrations.

In one embodiment, an anti-fouling agent may be added to the binder.

In a preferred embodiment, the anti-fouling agent is a tannin, in particular a tannin selected from one or more components from the group consisting of tannic acid, condensed tannins (proanthocyanidins), hydrolysable tannins, gallotannins, ellagitannins, complex tannins, and/or tannin originating from one or more of oak, chestnut, staghorn sumac and fringe cups.

In one embodiment, an anti-swelling agent may be added to the binder, such as tannic acid and/or tannins. Further additives may be additives containing calcium ions and antioxidants.

In one embodiment, the binder composition according to the present invention contains additives in form of linkers containing acyl groups and/or amine groups and/or thiol groups. These linkers can strengthen and/or modify the network of the cured binder.

In one embodiment, the binder compositions according to the present invention contain further additives in form of additives selected from the group consisting of PEG-type reagents, silanes, and hydroxylapatites.

The coherent composite preferably has a density of from 10 to 1200 kg/m3. In the particular case of use as a construction panel, the coherent composite may have a density above 900 kg/m3.

For use as an acoustic regulation material (e.g. sound absorption), the coherent composite may have a density of from 60 to 150 kg/m3, preferably from 80 to 150 kg/m3.

Sound absorption may be defined as a material with a weighted sound absorption coefficient a w >0.8 (Absorption class A and B - EN ISO 1 1654).

For use as a construction material, the coherent composite may have a density of above 400 kg/m3, such as 400 to 900 kg/m3. Densities above 900 kg/m3 are possible for construction panels.

For use as a thermal insulation material, the coherent composite may have a density of from 10 to 200 kg/m3, preferably from 60 to 150 kg/m3.

Thermal insulation may be defined as a material with a lambda value at 10°C of λ<0.060 W/m K.

The coherent composite may have a thickness of from 5 to 500 mm, such as from 5 to 20 mm, or 40 to 100 mm, or 200 to 400 mm. The invention is particularly beneficial for coherent composites of thicknesses above 150 mm as an alternative to those bonded using conventional thermoset binders. When a coherent composite has a relatively high density and thickness, it can be difficult to cure a thermoset binder in a conventional curing oven because the hot air is not easily able to pass into and through the product. In contrast, coherent composites according to the present invention can be cured at ambient temperature, even at relatively high thicknesses and densities.

The coherent composite may have a weight % binder solids in the composite of from 0.1 to 50.0 %, such as 0.3 to 36.0 %, such as 0.5 to 24.0 %, such as 0.7 to 16.0 %, such as 1.4 to 12.0 %, such as 2.0 to 8.0 %, based on the weight of the composite.

The range of 2.0 to 8.0 wt% binder solids may be particularly useful for low density fibre composites.

Higher wt% amounts of binder solids, such as from 25 to 50 wt% may be particularly useful for wood wool composites.

In one embodiment, the at least one hydrocolloid is present in the aqueous binder composition in an amount of 1 to 50, such as 2.5 to 25 wt.-%, based on the weight of the aqueous binder composition.

In one embodiment, the hydrocolloid comprises gelatine, wherein the gelatine is present in the aqueous binder composition in an amount of 10 to 95 wt.-%, such as 20 to 80 wt.-%, such as 30 to 70 wt.-%, such as 40 to 60 wt.-%, based on the weight of the hydrocolloids.

In the case where the non-binder components are non-combustible, the amount of binder may be calculated based on loss-on-ignition (LOI) testing.

The coherent composite of the invention is useful in various fields. For example, the coherent composite may be produced such that it is in the form of a rigid panel or as a pipe section. In terms of function, the coherent composite of the invention may be implemented as a thermal insulation material or a sound absorption material. In some embodiments, the coherent composite of the invention may be a mineral wool product.

In a preferred embodiment, the mineral wool product according to the present invention is an insulation product, in particular having a density of 10 to 200 kg/m 3 .

In an alternative embodiment, the mineral wool product according to the present invention is a facade panel, in particular having a density of approximately 1200 kg/m 3 .

In a preferred embodiment, the mineral wool product according to the present invention is an insulation product.

In one embodiment the mineral wool product is a mineral wool insulation product, such as a mineral wool thermal or acoustical insulation product.

In one embodiment the mineral wool product is a horticultural growing media.

Method

The invention also provides a method of producing a coherent composite. The method comprises the steps

• blending a substrate with a binder composition, and

• curing the binder composition to form a binder and thereby forming the

coherent composite;

wherein the binder composition comprises a hydrocolloid, and

wherein the substrate comprises a particulate material and/or fibres.

Preferably, the binder composition further comprises at least one phenol and/or quinone containing compound.

The substrate and binder composition are blended to form a mixture and the mixture is usually shaped to form the intended shape for the coherent composite. This shaping may be under pressure, optionally in a mould, or even use vacuum. Generally in the method, the step of blending substrate with a binder composition comprises mixing the substrate with the binder composition to form a homogeneous mixture. If the coherent composite includes mineral fibres, the binder may be supplied in the close vicinity of the fibre forming apparatus, such as a cup spinning apparatus or a cascade spinning apparatus, in either case immediately after the fibre formation. Preferably the fibres with applied binder are thereafter conveyed onto a conveyor belt as a web. The web may be subjected to longitudinal or length compression after the fibre formation and before substantial curing has taken place.

The curing step is preferably carried out a temperature of from 0 to 95 °C, preferably from 10 to 60 °C, more preferably from 20 to 40 °C. The web is cured by a chemical and/or physical reaction of the binder components.

In one embodiment, the curing takes place in a curing device.

In one embodiment the binder composition is capable of curing at a temperature of not more than 95 °C, such as 5-95 °C, such as 10-80 °C, such as 20-60 °C, such as 40- 50 °C.

The curing process may commence immediately after application of the binder to the fibres and optional particulate material. The curing is defined as a process whereby the binder composition undergoes a chemical reaction which 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. In one embodiment the curing process comprises cross-linking and/or water inclusion as crystal water.

In one embodiment the cured binder contains crystal water that may decrease in content and raise in content depending on the prevailing conditions of temperature, pressure and humidity. In one embodiment, the coherent composite comprises mineral fibres and the curing takes place in a conventional curing oven for mineral wool production operating at a temperature of from 5 to 95 °C, such as 10 to 60 °C, such as 20 to 40 °C.

In one embodiment the curing process comprises a drying process.

In one embodiment, the coherent composite comprises mineral fibres and the curing of the binder in contact with the mineral fibers takes place in a heat press. The curing of a binder in contact with the mineral fibers 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 to the mixture of fibrous and optional particulate material and binder. The blowing process may be accompanied by heating or cooling or it may be at ambient temperature.

In one embodiment the curing process takes place in a humid environment. The humid environment may have a relative humidity RH of 60-99%, such as 70-95%, such as 80-92%. The curing in a humid environment may be followed by curing or drying to obtain a state of the prevalent humidity.

The coherent composite can be in any conventional configuration, for instance a mat or slab, and can be cut and/or shaped (e.g. into pipe sections) before, during or after curing of the binder.

A particular advantage of the method of the present invention is that it does not require high temperatures for curing. This does not only save energy, reduces VOC and obviates the need for machinery to be highly temperature resistant, but also allows for a high flexibility in a process for the production of coherent composites with the binders used in the invention. EXAMPLES

The following examples below are of exemplary combinations of substrate and binder component(s). Preferred amounts of each component are also given for illustration purposes. The amounts of the binder composition components are in wt.% based on binder components solids content of the total binder composition. The amounts for the substrate part of the composite are stated in wt.% based on the total weight of the composite.

In one embodiment, a coherent composite according to the invention comprises the following components:

Substrate

Fibres wood wool, 95 %

Binder composition (before curing)

Hydrocolloid gelatine, 100 %

In one embodiment, a coherent composite according to the invention comprises the following components:

Substrate

Fibres wood wool, 95 %

Binder composition (before curing)

Hydrocolloid gelatine, 90 %

Crosslinker tannin, 10 % In one embodiment, a coherent composite according to the invention comprises the following components:

Substrate

Fibres polyester, 93 %

Binder composition (before curing)

Hydrocolloid gelatine, 90 %

Crosslinker tannin, 10 %

In one embodiment, a coherent composite according to the invention comprises the following components:

Substrate Fibres polyacrylonitrile, 93 %

Binder composition (before curing)

Hydrocolloid gelatine, 85 %

Crosslinker tannin, 15 %

In one embodiment, a coherent composite according to the invention comprises the following components:

Substrate

Fibres mineral wool, 97 %

Binder composition (before curing)

Hydrocolloid gelatine, 91 %

Crosslinker tannin, 9 %

In one embodiment, a coherent composite according to the invention comprises the following components:

Substrate

Fibres mineral wool, 46 %

Particulates aerogel, 46 %

Binder composition (before curing)

Hydrocolloid gelatine, 90 %

Crosslinker tannin, 10 %

In one embodiment, a coherent composite according to the invention comprises the following components:

Substrate

Fibres polyester, 35 %

Particulates aerogel, 60 %

Binder composition (before curing)

Hydrocolloid gelatine, 90 %

Crosslinker tannin, 10 %

In one embodiment, a coherent composite according to the invention comprises the following components:

Substrate

Fibres polyacrylonitrile, 35 % Particulates aerogel, 60 %

Binder composition (before curing)

Hydrocolloid gelatine, 91 %

Crosslinker tannin, 9 %

In one embodiment, a coherent composite according to the invention comprises the following components:

Substrate

Fibres mineral wool, 95 %

Binder composition (before curing)

Hydrocolloid pectin, 100 %

In one embodiment, a coherent composite according to the invention comprises the following components:

Substrate

Fibres mineral wool, 95 %

Binder composition (before curing)

Hydrocolloid starch, 100 %

In one embodiment, a coherent composite according to the invention comprises the following components:

Substrate

Fibres mineral wool, 95 %

Binder composition (before curing)

Hydrocolloid agar agar, 100 %

In one embodiment, a coherent composite according to the invention comprises the following components:

Substrate

Fibres mineral wool, 95 %

Binder composition (before curing)

Hydrocolloid alginate, 100 % In one embodiment, a coherent composite according to the invention comprises the following components:

Substrate

Fibres mineral wool, 93 %

Binder composition (before curing)

Hydrocolloid cellulose, 100 %

In one embodiment, a coherent composite according to the invention comprises the following components:

Substrate

Fibres mineral wool, 97 %

Binder composition (before curing)

Hydrocolloid gelatine + pectin, 100 %

In the following examples, several binders which fall under the definition of the present invention were prepared and compared to binders according to the prior art.

Binders according to the prior art

The following properties were determined for the binders according the prior art. Reagents

Silane (Momentive VS-142) was supplied by Momentive and was calculated as 100% for simplicity. All other components were supplied in high purity by Sigma-Aldrich and were assumed anhydrous for simplicity unless stated otherwise.

Binder component solids content - definition The content of each of the components in a given binder solution before curing is based on the anhydrous mass of the components. The following formula can be used:

binder component A solids (g) + binder component B solids (g) +■■■

Binder component solids content (%) = x 100%

total weight of mixture (g) Binder solids - definition and procedure

The content of binder after curing is termed "binder solids".

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 (see below for mixing examples) 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 binder solids were calculated as an average of the two results. A binder with the desired binder solids could then be produced by diluting with the required amount of water and 10% aq. silane (Momentive VS-142). Reaction loss - definition

The reaction loss is defined as the difference between the binder component solids content and the binder solids.

Mechanical strength studies (bar tests) - procedure

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. The shots are particles which have the same melt composition as the stone wool fibers, and the shots are normally considered a waste product from the spinning process. The shots used for the bar composition have a size of 0.25-0.50 mm.

A 15% binder solids binder solution containing 0.5% silane (Momentive VS-142) of binder solids was obtained as described above under "binder solids". A sample of this binder solution (16.0 g) was mixed well with shots (80.0 g). The resulting mixture was then divided evenly 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 hard 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 for 1 h. After cooling to room temperature, the bars were carefully taken out of the containers. Eight of the 16 bars were aged in an autoclave (15 min / 120 °C / 1.2 bar). After drying for 1-2 days, all bars were then 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. Loss of ignition (LOI) of bars

The loss of ignition (LOI) of bars was measured in small tin foil containers by treatment at 580 °C. For each measurement, a tin foil container was first heat-treated at 580 °C for 15 minutes to remove all organics. The tin foil container was allowed to cool to ambient temperature, and was then weighed. Four bars (usually after being broken in the 3 point bending test) were placed into the tin foil container and the ensemble was weighed. The tin foil container containing bars was then heat-treated at 580 °C for 30 minutes, allowed to cool to ambient temperature, and finally weighed again. The LOI was then calculated using the following formula:

Weight of bars before heat treatment (g~)— Weight of bars after heat treatment (g~) LOI ( / o ) Weight of bars before heat treatment (g) X

Reference binders from the prior art prepared as comparative examples

Binder example, reference binder A (phenol-formaldehyde resin modified with urea, a PUF-resol)

A phenol-formaldehyde resin is prepared by reacting 37% aq. formaldehyde (606 g) and phenol (189 g) in the presence of 46% aq. potassium hydroxide (25.5 g) 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 g) 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 mL) and ammonium sulfate (13.2 g) followed by water (1.30 kg). The binder solids were then measured as described above and the mixture was diluted with the required amount of water and silane (Momentive VS-142) for mechanical strength studies (15% binder solids solution, 0.5% silane of binder solids). Binders according to the present invention

The following properties were determined for the binders according the present invention.

Reagents

Gelatines (Speisegelatine, type A, porcine, 120 and 180 bloom; Imagel LB, type B, 122 bloom) were obtained from Gelita AG. Tannorouge chestnut tree tannin was obtained from Brouwiand bvba. Agar agar (05039), gellan gum (P8169), pectin from citrus peel (P9135), sodium alginate from brown algae (A0682), sodium carboxymethyl cellulose (419303), soluble starch (S9765), and sodium hydroxide were obtained from Sigma- Aldrich. For simplicity, these reagents were considered completely pure and anhydrous. Binder component solids content - definition

The content of each of the components in a given binder solution before curing is based on the anhydrous mass of the components. The following formula can be used:

binder component A solids (g) + binder component B solids (g) + ■■■

Binder component solids content (%) = — x 100%

total weight of mixture {g)

Mechanical strength studies (bar tests) - procedure

The mechanical strength of the binders was tested in a bar test. For each binder, 8-16 bars were manufactured from a mixture of the binder and stone wool shots from the stone wool spinning production. The shots are particles which have the same melt composition as the stone wool fibers, and the shots are normally considered a waste product from the spinning process. The shots used for the bar composition have a size of 0.25-0.50 mm.

A binder solution was obtained as described in the examples below. For comparatively slower setting binders, a sample of the binder solution (16.0 g for binders with 10-15% binder component solids; 32.0 g for binders with 5% binder component solids) was mixed well with shots (80.0 g). The resulting mixture was then divided evenly 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). For comparatively faster setting binders, a sample of the binder solution (8.0 g for binders with 10-15% binder component solids and 16.0 g for binders with 5% binder component solids) was mixed well with shots (40.0 g, pre-heated to 35-40 °C before use), and the resulting mixture was then divided evenly into two slots only. During the manufacture of each bar, the mixtures placed in the slots were pressed as required and then evened out with a plastic spatula to generate an even bar surface. 8-16 bars from each binder were made in this fashion. The resulting bars were then cured at room temperature for 1 -2 days or first cured for 15 minutes in an oven at the temperatures listed in the tables followed by curing for 1 -2 days at room temperature. If still not sufficiently cured after that time, the bars were cured for 1 day at 35 °C. The bars were then carefully taken out of the containers, turned upside down and left for a day at room temperature to cure completely. Half of the 8-16 bars were aged in an autoclave (15 min / 120 °C / 1 .2 bar).

After drying for 1-2 days, all bars were then 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.

Loss of ignition (LOI) of bars

The loss of ignition (LOI) of bars was measured in small tin foil containers by treatment at 580 °C. For each measurement, a tin foil container was first heat-treated at 580 °C for 15 minutes to remove all organics. The tin foil container was allowed to cool to ambient temperature, and was then weighed. Four bars (usually after being broken in the 3 point bending test) were placed into the tin foil container and the ensemble was weighed. The tin foil container containing bars was then heat-treated at 580 °C for 30 minutes, allowed to cool to ambient temperature, and finally weighed again. The LOI was then calculated using the following formula:

Weight of bars before heat treatment (g)— Weight of bars after heat treatment (g)

Weight of bars before heat treatment (g)

Binder compositions according to the present invention

Binder example, entry 1

A mixture of gelatine (Speisegelatine, type A, porcine, 120 bloom, 7.5 g) in water (42.5 g) was stirred at 50 °C for approx. 15-30 min until a clear solution was obtained (pH 5.1 ). The resulting solution was then used in the subsequent experiments.

Binder example, entry 3 A mixture of gelatine (Speisegelatine, type A, porcine, 180 bloom, 8.82 g) in water (50.0 g) was stirred at 50 °C for approx. 15-30 min until a clear solution was obtained (pH 5.2). The resulting solution was then used in the subsequent experiments. Binder example, entry 5

A mixture of gelatine (Imagel LB, type B, 122 bloom, 8.82 g) in water (50.0 g) was stirred at 50 °C for approx. 15-30 min until a clear solution was obtained (pH 5.1 ). The resulting solution was then used in the subsequent experiments. Binder example, entry 7

To water (50.0 g) stirred vigorously at 85 °C was added sodium carboxymethyl cellulose (2.63 g) portion-wise over approx. 15 minutes. Stirring was continued for 0.5- 1 h further at 85 °C until a clear solution was obtained (pH 8.4). The resulting solution was then used in the subsequent experiments.

Binder example, entry 8

To water (50.0 g) stirred vigorously at 85 °C was added soluble starch (2.63 g) portion-wise over approx. 15 minutes. Stirring was continued for 0.5-1 h further at 85 °C until a clear solution was obtained (pH 6.4). The resulting solution was then used in the subsequent experiments.

Binder example, entry 9

To water (50.0 g) stirred vigorously at 85 °C was added agar agar (2.63 g) portion- wise over approx. 15 minutes. Stirring was continued for 0.5-1 h further at 85 °C until a clear solution was obtained.

A mixture of gelatine (Speisegelatine, type A, porcine, 120 bloom, 8.82 g) in water (50.0 g) was stirred at 50 °C for approx. 15-30 min until a clear solution was obtained. A portion of the above agar agar solution (19.6 g, thus efficiently 0.98 g agar agar and 18.6 g water) was then added and stirring was continued at 50 °C for 5 min further (pH 5.3). The resulting solution was then used in the subsequent experiments.

Binder example, entry 10 To water (50.0 g) stirred vigorously at 85 °C was added gellan gum (2.63 g) portion- wise over approx. 15 minutes. Stirring was continued for 0.5-1 h further at 85 °C until a clear solution was obtained.

A mixture of gelatine (Speisegelatine, type A, porcine, 120 bloom, 8.82 g) in water (50.0 g) was stirred at 50 °C for approx. 15-30 min until a clear solution was obtained. A portion of the above gellan gum solution (19.6 g, thus efficiently 0.98 g gellan gum and 18.6 g water) was then added and stirring was continued at 50 °C for 5 min further (pH 5.3). The resulting solution was then used in the subsequent experiments.

Binder example, entry 11 To water (50.0 g) stirred vigorously at 85 °C was added pectin (2.63 g) portion-wise over approx. 15 minutes. Stirring was continued for 0.5-1 h further at 85 °C until a clear solution was obtained.

A mixture of gelatine (Speisegelatine, type A, porcine, 120 bloom, 8.82 g) in water (50.0 g) was stirred at 50 °C for approx. 15-30 min until a clear solution was obtained. A portion of the above pectin solution (19.6 g, thus efficiently 0.98 g pectin and 18.6 g water) was then added and stirring was continued at 50 °C for 5 min further (pH 4.8). The resulting solution was then used in the subsequent experiments.

Binder example, entry 12

To water (50.0 g) stirred vigorously at 85 °C was added sodium alginate (2.63 g) portion-wise over approx. 15 minutes. Stirring was continued for 0.5-1 h further at 85 °C until a clear solution was obtained.

A mixture of gelatine (Speisegelatine, type A, porcine, 120 bloom, 8.82 g) in water (50.0 g) was stirred at 50 °C for approx. 15-30 min until a clear solution was obtained. A portion of the above sodium alginate solution (19.6 g, thus efficiently 0.98 g sodium alginate and 18.6 g water) was then added and stirring was continued at 50 °C for 5 min further (pH 5.3). The resulting solution was then used in the subsequent experiments.

Binder example, entry 13 To 1 M NaOH (15.75 g) stirred at room temperature was added chestnut tree tannin (4.50 g). Stirring was continued at room temperature for 5-10 min further, yielding a deep red-brown solution.

A mixture of gelatine (Speisegelatine, type A, porcine, 120 bloom, 8.00 g) in water (72.0 g) was stirred at 50 °C for approx. 15-30 min until a clear solution was obtained (pH 4.8). 1 M NaOH (3.50 g) was then added (pH 9.3) followed by a portion of the above chestnut tree tannin solution (3.60 g; thus efficiently 0.80 g chestnut tree tannin). After stirring for 1 -2 minutes further at 50 °C, the resulting brown mixture (pH 9.2) was used in the subsequent experiments. Binder example, entry 14

To 1 M NaOH (15.75 g) stirred at room temperature was added chestnut tree tannin (4.50 g). Stirring was continued at room temperature for 5-10 min further, yielding a deep red-brown solution.

A mixture of gelatine (Speisegelatine, type A, porcine, 120 bloom, 10.0 g) in water (56.7 g) was stirred at 50 °C for approx. 15-30 min until a clear solution was obtained (pH 4.9). 1 M NaOH (4.00 g) was then added (pH 9.1 ) followed by a portion of the above chestnut tree tannin solution (4.50 g; thus efficiently 1.00 g chestnut tree tannin). After stirring for 1 -2 minutes further at 50 °C, the resulting brown mixture (pH 9.1 ) was used in the subsequent experiments. Binder example, entry 17

To 1 M NaOH (15.75 g) stirred at room temperature was added chestnut tree tannin (4.50 g). Stirring was continued at room temperature for 5-10 min further, yielding a deep red-brown solution.

A mixture of gelatine (Speisegelatine, type A, porcine, 180 bloom, 10.0 g) in water (56.7 g) was stirred at 50 °C for approx. 15-30 min until a clear solution was obtained (pH 4.8). 1 M NaOH (3.50 g) was then added (pH 9.2) followed by a portion of the above chestnut tree tannin solution (4.50 g; thus efficiently 1.00 g chestnut tree tannin). After stirring for 1 -2 minutes further at 50 °C, the resulting brown mixture (pH 9.2) was used in the subsequent experiments.

Binder example, entry 19

To 1 M NaOH (15.75 g) stirred at room temperature was added chestnut tree tannin (4.50 g). Stirring was continued at room temperature for 5-10 min further, yielding a deep red-brown solution.

A mixture of gelatine (Imagel LB, type B, 122 bloom, 10.0 g) in water (56.7 g) was stirred at 50 °C for approx. 15-30 min until a clear solution was obtained (pH 4.7). 1 M NaOH (3.50 g) was then added (pH 9.2) followed by a portion of the above chestnut tree tannin solution (4.50 g; thus efficiently 1.00 g chestnut tree tannin). After stirring for 1 -2 minutes further at 50 °C, the resulting brown mixture (pH 9.2) was used in the subsequent experiments.

Binder example, entry 21

To water (50.0 g) stirred vigorously at 85 °C was added agar agar (2.63 g) portion- wise over approx. 15 minutes. Stirring was continued for 0.5-1 h further at 85 °C until a clear solution was obtained.

To 1 M NaOH (15.75 g) stirred at room temperature was added chestnut tree tannin (4.50 g). Stirring was continued at room temperature for 5-10 min further, yielding a deep red-brown solution. A mixture of gelatine (Speisegelatine, type A, porcine, 120 bloom, 10.0 g) in water (56.7 g) was stirred at 50 °C for approx. 15-30 min until a clear solution was obtained (pH 4.6). 1 M NaOH (4.00 g) was then added (pH 9.1 ) followed by a portion of the above chestnut tree tannin solution (4.50 g; thus efficiently 1.00 g chestnut tree tannin) and then a portion of the above agar agar solution (20.0 g; thus efficiently 1.00 g agar agar). After stirring for 1-2 minutes further at 50 °C, the resulting brown mixture (pH 8.8) was used in the subsequent experiments.

Binder example, entry 22 To water (50.0 g) stirred vigorously at 85 °C was added pectin (2.63 g) portion-wise over approx. 15 minutes. Stirring was continued for 0.5-1 h further at 85 °C until a clear solution was obtained.

To 1 M NaOH (15.75 g) stirred at room temperature was added chestnut tree tannin (4.50 g). Stirring was continued at room temperature for 5-10 min further, yielding a deep red-brown solution.

A mixture of gelatine (Speisegelatine, type A, porcine, 120 bloom, 10.0 g) in water (56.7 g) was stirred at 50 °C for approx. 15-30 min until a clear solution was obtained (pH 4.6). 1 M NaOH (4.50 g) was then added (pH 9.6) followed by a portion of the above chestnut tree tannin solution (4.50 g; thus efficiently 1.00 g chestnut tree tannin) and then a portion of the above pectin solution (20.0 g; thus efficiently 1.00 g pectin). After stirring for 1 -2 minutes further at 50 °C, the resulting brown mixture (pH 8.9) was used in the subsequent experiments.

Binder example, entry 23 To water (50.0 g) stirred vigorously at 85 °C was added sodium alginate (2.63 g) portion-wise over approx. 15 minutes. Stirring was continued for 0.5-1 h further at 85 °C until a clear solution was obtained.

To 1 M NaOH (15.75 g) stirred at room temperature was added chestnut tree tannin (4.50 g). Stirring was continued at room temperature for 5-10 min further, yielding a deep red-brown solution.

A mixture of gelatine (Speisegelatine, type A, porcine, 120 bloom, 10.0 g) in water (56.7 g) was stirred at 50 °C for approx. 15-30 min until a clear solution was obtained (pH 4.6). 1 M NaOH (4.00 g) was then added (pH 9.2) followed by a portion of the above chestnut tree tannin solution (4.50 g; thus efficiently 1.00 g chestnut tree tannin) and then a portion of the above sodium alginate solution (20.0 g; thus efficiently 1.00 g sodium alginate). After stirring for 1 -2 minutes further at 50 °C, the resulting brown mixture (pH 9.0) was used in the subsequent experiments.

Binder example, entry 24 To water (50.0 g) stirred vigorously at 85 °C was added soluble starch (2.63 g) portion-wise over approx. 15 minutes. Stirring was continued for 0.5-1 h further at 85 °C until a clear solution was obtained.

To 1 M NaOH (15.75 g) stirred at room temperature was added chestnut tree tannin (4.50 g). Stirring was continued at room temperature for 5-10 min further, yielding a deep red-brown solution.

A mixture of gelatine (Speisegelatine, type A, porcine, 120 bloom, 10.0 g) in water (56.7 g) was stirred at 50 °C for approx. 15-30 min until a clear solution was obtained (pH 4.8). 1 M NaOH (4.00 g) was then added (pH 9.1 ) followed by a portion of the above chestnut tree tannin solution (4.50 g; thus efficiently 1.00 g chestnut tree tannin) and then a portion of the above soluble starch solution (20.0 g; thus efficiently 1.00 g soluble starch). After stirring for 1 -2 minutes further at 50 °C, the resulting brown mixture (pH 8.8) was used in the subsequent experiments.

TABLE 1 -1 : Reference binder

Example A

Binder properties

Binder solids (%) 15.0

Reaction loss (%) 28.5 pH 9.6

Bar curing conditions

Temperature (°C / 1 h) 200

Bar properties

Mechanical strength, unaged

0.39 (kN)

Mechanical strength, aged

0.28 (kN)

LOI, unaged (%) 2.8

Of hydrocolloid(s). [ J Of hydrocolloid(s) + crosslinker.

content (%)

As can be seen from comparing the results in Table 1.1 with Tables 1.2 and 1.3, the binder compositions used in the present invention require lower temperatures for curing. The reference binder composition requires temperatures of 200 °C for curing, while binder compositions 1 to 24 cure at 55 °C and below, typically at ambient temperature.