The present invention relates to a polymerisable composition, a method for applying a polymerisable composition and a device for applying a polymerisable composition and, more particularly, to the use of a polymerisable adhesive composition in the provision of protective coatings on metal objects, the reinforcement of concrete and the production of a particle/chipboard from sawdust or other waste materials.

The protection of metal objects from the destructive action of the surrounding medium and restoration and repair of metal objects on site has been a long standing problem and, until now, has not yet admitted of a generally acceptable solution owing to the wide variety of construction and operating conditions of the metal objects concerned.

A very common problem is, for example, the rusting and corrosion of metal pipes. A number of materials are known to be useful in protecting the internal surfaces of metal pipes, such as steel pipes, for example, polyvinyl chloride and various pulverulent thermoplastics.

Pure polyvinyl chloride has previously been used to manufacture tubular linings for insertion into pipes to secure and protect pipes from corrosion. Hot air is blown through the pipes until the tubular linings are softened and the tubular linings are then subsequently set by cooling. (See, for example, Dzaire to Purosesy = Curr. Adv. Mater, and Proc - 1990 Vol 3 No. 2, Page 695; Japan) .

With regard to the pulverulent thermoplastics, it is known to prepare such compositions in the form of gaseous suspensions in fluidised-bed apparatus and blow the suspension through heated pipes until polymer layers of a required thickness adhere to the internal surfaces of the pipes. The resultant coatings are stabilised by subsequent cooling. See, for example, French Patent No. 9016220.

A combination of materials varying in composition and state of aggregation, a first polymeric material being applied in powder form as a primer and a second oligomeric material being applied to the layer of primer, has also previously been used to protect the surfaces of metal objects, the primer acting as catalyst for the hardening of the subsequently applied oligomers. See, for example, British Patent No. 2094178.

These types of materials can, however, only give good results under static, controllable, factory conditions, or when the coatings are applied to the clean surfaces of metal objects which have not yet been used.

In the case of, for example, pipes, where these have been used for prolonged periods underground, the pipes will almost invariably have defects in the form of holes and variations in the thicknesses of their walls and their internal surfaces will be encrusted with conglomerates varying in shape, dimensions, solidity and chemical composition. Such encrustations include the products of chemical corrosion caused by the action of water and acids present in the soil, products of electro chemical corrosion caused by chemical agents and stray electrical currents in the soil, particularly where pipes are laid parallel to underground electric cables, mechanical impurities in liquid or gaseous conveying media and encrustations due to chemically combined or free water (it is almost impossible to dry the cavities of underground pipes completely) .

Another problem with underground pipes is that the thermal conductivity of the surrounding ground, particularly moist ground, is fairly high and its temperature at a depth of several metres under the surface is usually low, on average rarely exceeding 10°C. Wetting of metal surfaces with adhesive compositions is difficult at such low temperatures, leading to unsatisfactory adherence of the protective coatings to the underlying surface.

Numerous attempts have been made to find indirect solutions to the above-mentioned problems in the restoration and repair of underground pipe systems. For example, "Fibre Glass Rejuvenates Steel Pipe" (Can, Chem. Process, 1981, Vol. 65, No.3) discloses the use of sleeves manufactured from fibre glass with epoxy binders and provided with annular gaps. These sleeves are placed in corroded pipes and the annular gaps hermetically filled with hydraulically setting solutions e.g. an hydraulic cement.

Although this method is relatively useful for the repair of short straight sections of underground pipes, it also reduces the cross-section and corresponding carrying capacity of the pipes, which is not generally acceptable and, where underground pipes are laid in towns, the pipes will, as a rule, follow eccentric routes and will be laid at varying depths, so that short straight sections of pipes may be difficult to find.

There is, therefore, a pressing need to find an effective solution to the above-mentioned problems and to satisfy a number of requirements including strong adhesion of the cured protective, seal-tight, coatings to the underlying surfaces (usually steel or cast iron in the case

of underground pipes) , the ability to apply the protective coatings to underground pipes having various cross-sections and running in various directions, at varying depths, in a variety of different conditions and with minimum energy expediture, particularly of thermal energy.

One attempt to provide a solution to the above- mentioned problems is disclosed in Japanese Patent No. 57- 184476. In the method disclosed by this patent, a mixture of epoxy resin and curing agent is introduced into the end of a pipe in an isolated section of piping, compressed air is blown through the pipe cavity before preliminary coating of the internal surface of the pipe, the thickness of this "raw" coating is then calibrated by pushing a resilient ball through the pipe, including the curved parts of the pipes, and the "raw" material is then hardened to form a protective coating.

Although this method does satisfy certain requirements, this method has the disadvantage that polymerisable epoxy compositions cannot usually be applied to surfaces until the surfaces have been carefully cleaned, which is practically impossible in the repair of underground pipes. Furthermore, even though epoxy resins have high adhesive activity when liquid at room temperature, they are not always capable of effectively wetting metal surfaces at the low temperatures found in underground pipes.

In the repair of underground pipes, it is not only preferable to use polymerisable compositions having the high adhesive activity of epoxy resins, it is also desirable to be able to wet the surfaces to be coated under varying conditions and to adjust the viscosity of the polymerisable composition within very wide limits so that

the polymer composition may be hardened over a wide range of temperatures without heating. The use of simple equipment to apply such polymerisable composition to the underground pipes is also preferable.

"Raw" coatings can be applied using the method and device known from German Patent No. 3 147 396. The method disclosed by German Patent No. 3 147 396 comprises a preliminarily cleaning step involving mechanical removal of impurities from the metal surface, supplying (pouring) portions of polymerisable composition into a section of piping which has been isolated for repair, calibrating the thickness of the "raw" coating by means of a scraper and curing the polymerisable material until it hardens to form a protective coating. The device for carrying out this method comprises four main parts, connected in succession on a common support element (rod) , including a first control and a first scraper section which is provided with means for applying a layer of polymerisable composition to the metal surface, and a second control and a second scraper section, which serves as the means for calibrating the thickness of the layer of the polymerisable composition.

Each of the above-mentioned control sections comprises U-shaped resilient brackets which lie along the geometrical axis of the rod and which have ends which are radially bent and secured to the rod. The second control section is disposed on the rod and can move axially in reciprocation. The scraper in the first section has a constant diameter, considerably smaller than the narrowest diameter of the pipe to be repaired, whilst the scraper in the second section comprises an outer cone made of resilient material and firmly secured to the rod and an

inner cone made of harder material and secured to the second moveable control section.

The viscosity and working life of the above- mentioned previously disclosed polymerisable compositions can be adjusted within very wide limits and the presence therein of isocyanates and surface-active substances (i.e. polyfluorinated alcohol telomer and the block co-polymer of polyorganosiloxane and polyoxyalkylene) enable these compositions to be used for forming anti-corrosive coatings in moist mediums such as that found in underground pipes.

The disadvantage of these previously known compositions is, however, that isocyanates may undergo uncontrolled reactions with moisture irrespective of the source of moisture, resulting in the undesirable evolution of carbon dioxide and local foaming of the coating material. Isocyanates can react with oligoesters, which always contain residual quantities of water, and free reactive hydroxyl and carboxyl groups in this way, so that use of isocyanates in oligoester compositions significantly reduces the usefulness of such compositions for underground repair work and makes it practically impossible to obtain continuous anti-corrosive and hematic coatings over the entire surfaces of pipes to be repaired.

Wood-chip boards are obtained by pressing wood chips mixed with urea formaldehyde or resol phenol formaldehyde resin at a temperature of 170 - 180°C. The binder makes up 10 - 15% of the weight of the chips. These boards have the serious disadvantages of toxicity, non- resistance to moisture and high consumption of energy for producing the boards, associated with the high pressing temperature and the need to dry the chips to 2% moisture content before pressing.

Thermoplastics (polyethylene, polyvinyl chloride etc) or synthetic resins (epoxides, polyesters, etc) used as binders for producing pressed articles also require careful drying of the wood filler, and also the consumption of binder in this case is 40 - 60%, which greatly increases the cost of the pressed articles (USSR inventor's Certificate No, 1 544 567, Class B27 No. 3/02, 1988; S. V. Gepel', Drevesnye Plastiki v tekhnike, Moscow, 1959; I. L. Yelin, N.V. Zhur and I. L. Sheidin, Plastiki I Dekorativnye Materialy Iz Drevesiny, Ikh Svoistva I Primenenie v Sudostroenii, Leningrad 1961; N. Ya Solechnik, Proizvodstvo drevesno-voloknistykh plit, Moscow-Leningrad, 1959; G. M. Shvartzman, Proizvodstvo drevesno-struzhechnykh plit, Moscow 1959; V.I. Mololetov, Pressovannaya drevesina I primenenie Yeyo v Maschinostroenii, a manual edited by A.G. ftakin, Moscow and Leningrad 1965.

A recently-discovered class of polymerisable compositions based on polyisocyanates can be used in order to reduce the toxicity of the compression-moulded articles and increase their resistance to water.

The method of manufacturing wood-chip boards comprises drying the crushed wood, mixing it first with the inorganic binder component and then with the organic component, shaping a mat and hot compression moulding.

However, the compositions have a disadvantage in that all their components diffuse into the mass of particles of wood filler, which increases the consumption of the compositions. In addition, the compression-moulding temperature is above 100°C and requires careful drying of the crushed wood, which increases the energy consumed in the production of wood-chip board.

Repeated attempts have been made to use polymer compositions for impregnation of soil, concrete, wood and plaster. There are descriptions of use of compositions based on polyepoxides, unsaturated polyester resins, carbamide and phenol-formaldehyde resins, diisocyanates etc.

Over many years, no solution has been found to the problem of impregnating porous materials with polymer compositions to a sufficient depth, since porous materials have a highly extended surface and adsorb the individual components of the composition, resulting in chromatographic separation thereof, so that the composition does not solidify. To prevent this happening, single-component impregnating compositions have been proposed, such as ethyl alpha cyanoacrylate, which solidify under the action of traces of moisture on the surface of the pores. This substance has hitherto been used for expensive work, such as restoration. It is not widely used in practice, owing to its high cost and quick solidification, which makes deep impregnation of material impossible.

Industrial military applications have resulted in a method of impregnation with methyl methacrylate and subsequent solidification or hardening thereof by ionising radiation. The use of radiation, of course, limits the wide use of this method.

If selective sorption of components of the system is reduced, the surface tension of the surface pores can be reduced, and in this connection it has been proposed first to dry the materials with solutions of surface-active substances, or to introduce them directly into the polymer composition. The drawback of this method is that surface- active substances on the surface of a solid body may form

polymolecular adsorption layers, which greatly reduce the adhesion of the polymer to the solid surface, so that the strength of the impregnated material cannot be increased sufficiently.

When wet concrete and other materials are impregnated, the water in the pores prevents the polymer composition penetrating through the concrete. This obstacle is one of the main reasons why wet concrete is impregnated by using water-soluble mixtures of inorganic salts such as "Penetron", which react with the components of the concrete block and are deposited in the pores, when they change into an insoluble state. These mixtures can reduce the porosity of concrete, but polymer compositions are necessary as impregnating liquids for increasing characteristics such as deformability, chemical stability, resistance to abrasion, and strength.

One aim of the present invention is, therefore, to provide a significantly improved polymerisable composition having at least one or more of the following properties: high adhesive and cohesive activity, high resistance to aggressive mediums, an adjustable working life despite medium conditions, an adjustable hardening/curing time despite medium conditions, a viscosity which can be adjusted within a wide range of temperatures without heating, the ability to wet surfaces effectively in a wide range of medium conditions (including the ability to wet moist surfaces and surfaces contaminated with impurities which cannot be mechanically removed) and in which uncontrolled chemical reactions are eliminated. Another aim of the present invention is to provide an improved method for adhering materials, an improved method for applying a polymerisable composition to a surface which enhances the polymerisation process with minimum thermal

energy consumption and a simple device for applying the polymerisable composition to a surface.

It is one object of the "sawdust" aspect of the invention to produce a composition and method of use thereof so as greatly to reduce the cost of manufacturing woodchip board by reducing the consumption of binder and the consumption of energy.

More specifically the invention can provide the following advantages:

Improving the qualitative and quantitative composition, to produce a polyisocyanate-based composition enabling the binder to solidify quickly during the time that woodchip board is pressed at a temperature not exceeding 100°C;

Specifying a method of using the ingredients of the composition, to reduce the diffusion of components of the composition into the mass of particles of wood filler; and

Changing the technological parameters of compression-moulding of woodchip board, to reduce the energy consumption.

An object of one aspect of the invention is to improve the qualitative and quantitative composition by producing a solidifying low-viscosity composition which can additionally physically and chemically activate the surface of the pores in a wet concrete block, so as to ensure that the solidifying composition adheres firmly to the concrete and so as to prevent the components being separated by adsorption during the concrete impregnation process.

According to the present invention, there is provided a polymerisable composition comprising a mixture of an unsaturated oligoester, a cross-linking agent and a complex surface-active agent, wherein the complex surface- active agent comprises at least one of an oxyethylated alkyl phenol ester having the general formula:

^C _n H( _{2n + 1} ) ^C ₆ H<,0 (C ₂ H,,0) _m H, where n = 8 - 10 and m = 6 - 12 and

alkyl polybenzyl pyridinium chloride having the general formula:

[C _n H _{(2n +} C ₆ H ₄ CH ₂ (C ₅ H ₄ CH ₂ ) _m N ⁺ C ₅ H ₅ ]Cl ^" where n = 6 - 8 and m = 1 - 4

The surface-active agent in this polymerisable composition ensures effective wetting of the surface to which the composition is applied in a wide range of conditions (including effective wetting of moist and contaminated surfaces) and also improves adhesive strength.

Preferably, the polymerisable composition further comprises at least one accelerator. The accelerator acts to improve cohesive strength.

More preferably, the polymerisable composition further comprises a filler. The filler acts to improve chemical resistance of the cured product.

Preferably, the filler comprises a dispersed material in the form of flakes having thicknesses of 0.1 to 20nm and diameters of 0.1 to 5.0mm.

More preferably, the polymerisable composition further comprises at least one polymerisation initiator. The polymerisable composition of the present invention may be provided as a one-part mixture, in which the polymerisable composition includes the polymerisation initiator, or a two-part mixture, in which the polymerisation initiator is provided separately to the polymerisable composition and then added to the polymerisable composition at the point of use.

Preferably, the polymerisable composition comprises, per 100 parts by weight of mixture of oligoester and cross-linking agent, the following proportions of ingredients (in parts by weight) :

Polymerisation initiators(s) 0.1 - 5.0

Polymerisation accelerator(s) 0.01 -2.0

Complex surface-active agent 6.02-8.20

Filler 5.0 - 100

This polymerisable composition makes use of two types of additive, one to increase the adhesion effect of the polymer used (the complex surface-active agent) and the other to increase the cohesive effect (the accelerator) .

More preferably, the oxyethylated alkyl phenol ester and alkyl polybenzyl pyridinium chloride are present in the polymerisable composition in the following quantities (in parts by weight) :

Oxyethylated alkyl phenol ester 6.0- 8.0

Alkyl polybenzyl pyridinium chloride 0.02-0.20

Preferably, the oligoester comprises an oligomaleate selected from the group consisting of:

(a) a product of interaction between diethylene glycol and maleic acid and phthalic acid,

(b) a product of interaction between triethylene glycol and maleic acid and adipic acid, and

(c) a product of interaction between oxyalkylated diphenyl and maleic acid and isophthalic acid.

Preferably, the cross-linking agent comprises a monomer selected from the group consisting of styrene, triethylene, glycol dimethacrylate and methyl methacrylate.

According to another aspect of the present invention, there is provided a device for applying a polymerisable composition to a surface of a metal object, which device comprises means for applying a layer of polymerisable composition to the surface of the metal object, the application means having an enclosed space for at least partially filling with the polymerisable composition in use, and means disposed within the enclosed space for exposing, in use, the surface of the metal object to which the layer of polymerisable composition to be applied. This device provides a very simple means for applying a polymerisable composition to a wide range of objects, including the internal surfaces of underground pipes, in situ.

Preferably, the means for exposing the surface of the metal object under the layer of applied polymerisable composition comprises a first micro-scalper or needle mill. This physically activates the surface of the metal object

to improve the strength of adhesion of the cured product to the metal object.

Preferably, a second micro-scalper or needle mill is disposed outside the enclosed space, ahead of the application means. This allows a preliminary cleaning and de-scaling step to be carried out before application of the polymerisable composition, which again adds to improvement of adhesive strength.

Preferably, each micro-scalper or needle mill is connected to a generator of electric pulses for electro- machining the surface of the metal object. Electro- machining of the surface of the metal object creates a free radical status to which a chemically active polymerisable composition may be added, resulting in an adhesive activity of greatly improved strength.

Preferably, each of the micro-scalpers or needle mills comprises a metal brush.

Preferably, the device further comprises means for calibrating the thickness of the layer of applied polymerisable composition.

More preferably, the calibrating means comprises a resilient element for contacting the layer of applied polymerisable composition, the resilient element being secured, in use, to the application means.

According to a further aspect of the present invention, there is provided a method of adhering materials, which method comprises physico-chemically reacting a first active surface having a free radical status with a second active surface having a molecular

15 active centre. Such a method provides a greatly and surprisingly improved adhesive strength.

Preferably, the first active surface comprises a surface of a metal object and the second active surface comprises a polymerisable composition, the first active surface being activated by electro-machining.

Alternatively, the first active surface comprises a concrete surface and the second active surface comprises a polymerisable material, the first active surface being activated by extraction of calcium.

Alternatively, the first active surface comprises sawdust or an agricultural waste product and the second active surface comprises a polymerisable binding composition, the first active surface being activated by compression power and subsequent heating processes.

Preferably, the agricultural waste product comprises rice, straw or husks.

According to a further aspect of the present invention, there is provided a method of applying a polymerisable composition to a metal surface, which method comprises distributing the polymerisable composition over a working area of the metal surface and physically activating the working area of the metal surface until residues of solid impurities are fragmented and the surface of the metal under the layer of applied polymerisable composition is exposed. Such a method greatly enhances the strength of adhesion of the final product to the underlying surface.

Preferably, the method further comprises the step of physically cleaning the working area of the metal surfaces by mechanically removing impurities before distributing the polymerisable composition over the working area.

Preferably, the physical activation and/or physical cleaning of the working area of the metal surfaces carried out by micro-scalping.

Preferably, the physical activation and/or physical cleaning of the working area of the metal surfaces is carried out by electro-machining. Electro-machining of the surface of the metal object creates a free radical status to which addition of a chemically active and polymerisable composition will result in an adhesive activity of greatly improved strength.

More preferably, electro-machining is carried out by supplying electric pulses to the working area of the metal surface via a micro-scalper, needle mill or metal brush.

Preferably, the method further comprises the step of calibrating the thickness of the layer of distributed polymerisable composition.

Preferably, the method further comprises the step of curing the layer of polymerisable composition to form a protective coating.

According to the present invention there is further provided a binding material comprising an organic component comprising a polyisocyanate, a hardening agent and an inorganic salt. The non-organic salt is for binding the

humidity and strengthening of the end product. Such a binding material may be used for binding sawdust and agricultural waste so that the end product is again stronger, non-toxic and economically safe and does not require an additional protective coating for use in open air. Only a reduced amount of binding material is, again, required and sawdust and agricultural wastes having humidity up to 40% can be used.

The present invention further provides a method for mixing a filler with a binder according to the present invention wherein the filler is initially mixed with the hardening agent, subsequently with the inorganic salt and then finally with the organic component.

The present invention further comprises a method of producing compression moulded articles comprising moulding a mat of a filler with a binder according to the present invention and hot compression moulding the mat in a temperature range of 60 - 100°C. It is preferred that the filler is not previously subjected to drying.

One aspect of the invention relates to the art of moulding compressed articles, more specifically to the qualitative and quantitative composition of polymer binders; a method of applying polymer binders to particles of compressed material and parameters of the industrial process of compressed articles.

The invention may most effectively be applied to production of wood-chip boards and pressed articles made from sawdust, waste from hemp, flax, cotton and rice processing and other organic powders and mixtures thereof with inorganic powders.

In one embodiment of the invention an oligomer is introduced into the polyisocyanate composition, the oligomer comprising a polyester with polyoxyethylene fragments in the chain, applied with a dispersion of calcium hydroxide (lime paste) in water, and a solution of sodium silicate (water glass) .

A further aspect of the invention relates to the quantitative and qualitative make-up of polymer compositions for impregnating dry or wet concrete.

According to the present invention there is further provided a composition for reinforcing concrete, comprising phenyl glycidyl ester, having the general formula

C ₆ H ₅ - 0 - CH ₂ - CH - CH 0

pyridine and a solidifying epoxide composition comprising epoxide oligomer and an amine curing agent.

An epoxide oligomer is a substance containing two or more primary amine groups. Pyridine is the aromatic compound C ₆ H ₅ N.

The composition of the aspect of the invention may most effectively be applied to impregnation of concrete constructions or buildings in order to improve their strength, sealing-tightneεs and protection from corrosion, or for impregnating other kinds of porous materials such as soil, wood, asphalt, splint-slab and plaster boards, loose corrosion on the surface of metal articles and the like.

Phenyl glycidyl ester (FGE) and pyridine, adsorbed on the surface of the concrete pores, make them water-

repellent and provide the conditions whereby water is displaced from the interior of the concrete block and replaced by the polymer composition.

The ingredients of a preferred composition are taken in the following proportions (in parts by weight) :

Epoxide oligomer 100

Amine curing agent 5 - 60

FGE 10 - 100

Pyridine 0.6-1.8

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, examples of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows a part cross-sectional plan view of a first device for applying a polymerisable composition to a surface, the device shown being located within a portion of a pipe; and

Figure 2 shows a part cross-sectional front view of a second device for applying a polymerisable composition to a surface, the device shown being located on a curved surface.

Examples of oligoesters and cross-linking agents which may be used in the polymerisable composition of the present invention are set out in Table 1 below, although any other suitable oligoester or cross-linking agent may be used, including any of the numerous monomers and oligomers currently on the market.

TABLE 1

A LIST OF EXAMPLES OF MIXTURES OF OLIGOESTERS AND CROSS-LINKING AGENTS

between triethylene glycol and maleic acid and ad pic acid

1?3 A product of interaction 2.5 Styrene 60:40 PN-10 between oxyalkylated diphenol and maleic ac d and isophthalic acid

The oligomers and cross-linking agents mentioned in Table 1 are relatively inexpensive. The mixtures of the oligomers and cross-linking agents set out in Table 1 can be prepared by standard techniques, for example, metering and agitation and the proportions given in column 3 of Table 1 are, given by way of indication only and any other suitable proportions may be used. Mixture PN-1 is the least expensive to prepare.

Mixture PN-609 yields practically non-toxic coatings and is, therefore, preferable for repair of underground pipes carrying drinking water. Other properties of mixture PN-609 are very similar to those of mixtures PN-69 and PN- 10.

The property of the coating resulting from mixture PN- 1M is equivalent to the mixture of PN-1.

Mixture PN-69 can provide highly resilient coatings and is, therefore, preferred for repair of, for example, ship deck facings.

Mixture PN-10 yields the most chemically stable coatings, particularly against acids in crude oil and is, therefore, preferred for repair of pipes carrying such material.

The polymerisable compositions of the present invention also comprise a complex surface-active agent and, according to one example of the invention, the complex surface-active agent contains the following components in parts by weight per 100 parts by weight of oligomer:

6.02 to 8.0 oxyethylated ester alkyl phenol having the general formula:

C _n H _{(2n + 1)} C ₆ H ₄ 0(C ₂ H,0) _m H _/ where n = 8 to 10 and m = 6 to 12 and

0.02 - 0.20 alkyl polybenzyl pyridinium chloride having the general formula:

[C _n H _{(2n + 1)} C ₆ H,CH ₂ (C ₆ H,CH ₂ ) _m N ⁺ C ₅ H ₅ ]Cl ^" where n = 6 to 8 and m = 1 to 4

This surface-active agent acts to reduce the free energy of the system, thereby improving wettability of low- energy substrates, so as to ensure efficient coating of moist metal surfaces or metal surfaces within the environment of other liquids and penetration of the polymerisable composition into any defects in the surface to be coated.

The surface-active agent also increases the adhesive strength, which is surprising in view of the fact that, in the majority of cases, addition of surfactants to the polymerisable composition results in a decrease of adhesive strength or acts within only a narrow range of surfactant concentrations, this range depending on numerous factors, including adhesive viscosity, cure rate, gluing temperature, etc.

Examples of initiators which may be used to initiate polymerisation of the polymerisable composition of the present invention include peroxide-type or hydro-peroxide- type initiators such as benzyl peroxide, methyl, ethyl, ketone peroxide or isopropyl benzene hydroperoxide. One example of the polymerisable composition of the present invention comprises at least one of these polymerisable initiators in the proportion of 0.1 to 5.0 parts by weight per 100 parts by weight of oligoester, or in any other quantity sufficient to initiate the polymerisation process. The polymerisation initiator can be manufactured and sold separately from the rest of the composition.

Examples of polymerisation accelerators which may be added to the polymerisable composition of the present invention include amine or organic metal enhancers of the polymerisation process, for example, dimethyl aniline, cobalt naphthenate or vanadium pentoxide. One example of the polymerisable composition of the present invention comprises at least one of these accelerators, or other suitable accelerators, in the proportion of 0.01 - 2.0 parts by weight per 100 parts by weight of oligomer or in any other quantity sufficient for adjusting the working life of the composition.

The polymerisable composition of the present invention may also contain a highly dispersed natural mineral (e.g. basalt) or artificial (e.g. glass) filler material in the form of flakes, which preferably have a thickness of 0.1 to 20nm and a diameter of 0.1 to 5.0 mm are preferably provided in the proportion of 5.0 to 100 parts by weight per 100 parts by weight of oligomer and preferably between 80/20 and 50/50 parts by weight of filler to parts by weight of oligomer. The addition of filling agents such as basalt flake to the polymerisable compositions of the present invention helps to increase the chemical resistance of the resulting product, an increased proportion of filler material providing an increased chemical resistance.

Mixtures of the above-mentioned or other suitable materials can be prepared according to standard techniques and two-part packages can be prepared for simplified practical use. For example, a first package may be prepared containing a mixture of unsaturated oligoesters, a cross-linking agent, one or more suitable accelerators or enhancers and a complex surface-active agent and a second package containing polymerisation initiators. The two packages would then need to be mixed in order to initiate the polymerisation process.

Examples 1 - 40

A number of examples of polymerisable compositions according to the present invention were prepared as set out in Table 2 below as well as comparative Example 1.

IS) 1/1 EXAMPLES OF POLYMERISABLE COMPOSITIONS AND MEASUREMENTS OF ADHESIVE STRENGTH

© O

Os PQ O Type of Mixture Surface-Active Agent Adhesive Strength (M a) in: υ

PN-1 PN-609 Oxyethylated Alkyl Air Water Oi 1 alkyl phenol polybenzyl ester pyridinium chloride

4.0 6.0 7.0 8.0 10.0

0 ^• L ooτ 0 '9 ooτ 0' ooτ ooτ

2 -0 0 '01 τ -o o -oτ z ^■ o o ^• /. r τ -o 0 ^• L u

9 "0 o ^• t> τo Ό 0 ^• t7

9 -0 fr ^* 0 2 ^* 0 r -o ςo -o

τ -o 0 -6 ooτ e

2'0 0 ^* 8 ooτ sε ςτ -o 0 "8 ooτ τ Ό 0'8 ooτ 9 vo "0 0 ^• L ooτ ς

20 "0 O'Δ ooτ i-ε r t? -o ooτ εε

2Ό ooτ 2ε τ -o ooτ τε vo ^• o ooτ 62

2o ' o ooτ 82 τo "o ooτ Δ2 o -oτ ooτ 92 τ

For each 100 parts by weight of mixture of oligoester and cross-linking agent, five parts by weight of a filling material was used in all cases, since the experiments were carried out under relatively static laboratory conditions and this was a sufficient amount to evaluate its function as a regulator of viscosity and a means of ensuring a continuous coating.

Initiators and accelerators were also included within the above-mentioned limits, whereas the quantities of oxyethylated alkyl phenol ester and alkyl polybenzyl pyridinium chloride used fell both within and outside the aforementioned limits.

Samples of the polymerisable compositions prepared according to Table 2 were applied in various media (air, under water or under a layer of oil) to the surfaces of specimens of worn steel pipes having defects in small surface areas (not more than 1% of the area of the test piece and not more than 1mm ² each time) or having impurities in the form of loose layers of rust with interspersed solid oxide conglomerates in various media. The resulting cured coatings were visually evaluated with regard to their continuity and the strength of adherence to the underlying material was determined according to standard techniques.

In all cases, without exception, continuity of the coating to form an hematically sealed layer was achieved.

Furthermore, in all cases, the surface active additives ensured sufficiently strong adhesion to the underlying material and, when used within the specified limits, improved the adhesive strength.

Whilst the polymerisable compositions of the present invention are particularly useful in repairing and protecting worn, underground water, gas or oil pipes etc. in situ, without continuous uncovering of pipe runs, the

polymerisable compositions of the present invention may be used to provide protective, anti-corrosive, chemical resistant, hematic coatings on the internal or external surface of any metal object, for example, metal reservoirs for holding liquids or gases, metal tanks, and metal components of ships' holes, deck coverings and hole platings etc.

Examples of a device for applying a polymerisable composition according to the present invention, or any other suitable polymerisable composition, to the surface of a metal object are shown in Figures 1 and 2 of the accompanying drawings.

The device of the present invention may be used to apply a polymerisable composition to the internal or external surface of a metal object, irrespective of the shape of the surface, and certain features of the device greatly enhance the polymerisation process and the adhesive strength of the coating formed.

The devices shown in Figures 1 and 2 of the accompanying drawings each comprise a first support element in the form of a shaft 1 secured to a rotary drive (not shown) . A rubber vessel or plunger 2 for applying a layer of polymerisable composition to the surface of a metal object is connected to the fist shaft 1 and is provided with an enclosed space for at least partly filling with a polymerisable composition. A calibrating device 3 for calibrating the thickness of the layer of applied polymerisable composition is secured to the rubber vessel 2 and is adapted to make contact with the layer of applied polymerised composition. Provided within the rubber vessel 2 is a micro-scalper or needle mill comprising a metal brush 4, for physically activating the metal surface.

In cases where the polymerisable composition is to be applied to a metal surface which is severely contaminated with mechanical impurities other than organic substances such as fats, oil or oil products, the device further comprises a second micro-scalper or needle mill 5 disposed outside the rubber vessel 2, adjacent the rubber vessel 2 and ahead of the normal direction of movement of the rubber vessel 2 for applying the polymerisable composition.

In cases where the polymerisable composition is to be applied to a surface which is severely contaminated with organic substances such as fats, oil or oil products, the first and, if present, second micro-scalpers or needle mills 4 and 5 are connected to generators 6 and 7 respectively, which generators 6, 7 generate electric pulses for the purpose of electro-machining the surface of the metal object.

The device shown in Figure 1 is used for applying coatings to the internal surfaces of pipes. The rubber vessel is formed by two opposed discs 2,3 which are resilient, at least in their peripheral parts, and are disposed in sequence on the first shaft 1. The rear disc in the normal direction of movement, also forms a calibrating device 3 behind the normal direction of movement of the rubber vessel for applying a layer of polymerisable composition to the surface of the metal object. The vessel in Figure 1 has a rectangular cross- section and is adapted to fit within the pipe with the long faces of the rubber vessel contacting the internal surfaces of the pipe.

Each metal brush 4, 5 in Figure 1, comprises a disc with a plurality of needles extending therefrom. The metal brushes 4 , 5 shown in Figure 1 are secured to the same

first shaft 1, with the needles extending radially therefrom so as to contact the inner surfaces of the pipe to which the polymerisable composition is to be applied. The first metal brush 4 is located within the rubber vessel and the second metal brush 5 is located outside the rubber vessel on the end of the shaft 1, at a distance from the rubber vessel and ahead of the normal direction of movement of the rubber vessel 2 for applying a layer of polymerisable composition.

The device shown in Figure 2 is used for applying a polymerisable composition to the external surface of a metal pipe or to any other open surface, which may be curved. The rubber vessel 2' in Figure 2 also has a rectangular cross-section, but here, the calibrating device 3 ^* is in the form of a resilient ring clamped around the periphery of one long face of the rubber vessel 2 ' . Furthermore, the first shaft 1 extends through the opposing long face of the rubber vessel 2 ' and is disposed on bearings (not shown) and a second shaft is provided outside the rubber vessel 2', as explained below.

The metal brushes 4, 5 shown in Figure 2, again comprise discs with a plurality of metal needles extending therefrom and the first metal brush 4 in Figure 2 is secured to one end of the first shaft 1 within the rubber vessel 2 ' , with the metal needles extending outwardly from the metal disc along the axis of the shaft 1. The metal needles of the first metal brush 4 are arranged to contact the metal surface to which the polymerisable composition is to be applied and are adapted for face milling of the metal surface.

The second metal brush 5 of Figure 2 has the same construction as the first metal brush 4, but is located

outside the rubber vessel 2 • and is mounted at one end of the second shaft, which is independently connected to the rotary drive (not shown) .

The devices shown in Figures 1 and 2 may be used to apply a polymerisable composition to the surface of a metal object as follows:

The surface of the metal object may first, optionally, be subjected to preliminary cleaning and de-scaling in order to remove impurities, which may be carried out using any suitable means or by using the second metal brush 5 outside the rubber vessel 2 ' of the device of the present invention. The generator 7 attached to the second metal brush 5 may be used to electro-machine the surface of the metal object so as to burn up any anti-adhesion active impurities and in order to break up only large conglomerates of solid impurities. Preliminary cleaning is particularly advisable for rusty and corroded surfaces of used pipes.

Following the optional preliminary cleaning step, the rubber vessel 2 of the device of the present invention is rotated and moved along the surface (or surfaces) of the metal object so as to supply and distribute the polymerisable composition over the desired working area.

The surface of the metal object below the layer of applied polymerisable composition is then physically activated using the first metal brush 4 until the original surface under the layer of polymerisable material is exposed. The generator 6 connected to the first metal brush 4 may, again, be switched on to electro-machine the surface of the metal object below the layer of applied polymerisable composition in order to destroy the remaining

residues and conglomerates of solid impurities which are resistant to micro-scalping and dispersing the products of final cleaning and de-scaling into the layer of polymerisable material. The dispersed particles of impurities obtained by the physical activation of the underlying surface become additional fillers in the composition of the finished coating and the original surface which is exposed under the layer of polymerisable composition is blocked by the chemically active ingredient of the polymerisable composition, which improves the adhesion of the finished coating to the underlying material. The processing speed of the coating, for example, the coating of an inner surface of a pipe with a protective layer using the polymerisable composition and device of the present invention may be conducted at about lokm per hour and can be conducted at a speed of up to 60km per hour.

Example 41

A polymerisable composition according to the present invention having the following components was prepared:

PN-609 100

Methyl ethyl ketone peroxide 2

Cobalt naphthenate 1

OEAF 7

APBPCh 0.1

Basalt flakes 20

An approximately 0.4mm layer of this polymerisable composition was applied to the surface of a carbon steel plate using a device according to the present invention. After application of the polymerisable composition, the surface of the plate was machined with electric pulses

using the first metal brush 4 and generator 6 of the device of the present invention. The pulse duration was 200 microseconds and the energy was 0.7 joules. 45% of the original surface of the carbon steel plate was machined in this way.

The time taken for the composition to harden at 20°C was three hours. Five days after the coating hardened, a dolly was cemented to the coating and the force needed to separate the coating from the carbon steel plate was measured. The adhesive strength was found to be 38 MPa.

Example 42

The inner surface of a corroded metal pipe, 300mm in diameter and filled with water, was machined with a metal brush, using electric pulses. The pulse duration was 500 microseconds, the energy was 2 joules and 60% of the inner surface of the pipe was electro-machined.

After the surface of the pipe had been electro- machined, a composition according to Example 41 was applied in a thickness of 0.5mm using a device according to the present invention. After the composition had been applied, the metal surface of the pipe was again machined with electric pulses at a pulse duration of 100 microseconds and an energy of 0.01 joules, 60% of the pipe surface was machined in this way. Five days after application of the covering, the adhesive strength of the coating was found to be 28 MPa.

The method of applying a polymerisable composition to the surface of a metal object using a device according to the present invention, greatly enhances the adhesive

activity of the polymerisable composition so that the resulting protective layer is more securely adhered to the surface of the metal object. The principle used to create this improved adhesive coating is the simultaneous provision of two active surfaces, one in a full free radical status (the surface of the metal object) and the other having molecular active centres (the polymerisable composition of the present invention) , the two surfaces being able to react physico-che ically.

Electro-machining of the surface of the metal object by the second metal brush 5 outside the rubber vessel 2 activates the surface of the metal object to which the polymerisable composition is to be applied thereby creating a free radical status. A polymerisable composition according to the present invention is then applied to this activated surface of the metal object and electro-machining by the first metal brush 4 within the rubber vessel 2 acts to eliminate the water layer in contact with the surface of the metal object, which is then replaced by the surface- active agent in the polymerisable composition of the present invention to create a diamond-like ultra-hard adhesive surface.

The ultra-hard gluing surface then becomes flexible as the accelerator in the polymerisable composition reacts to form multiple layers of polymer-accelerator mix and this allows the hardening time of the polymerisable composition to be adjusted, as desired (usually between 5 minutes and 48 hours depending on application purposes) .

Thus, the method of the present invention involves three different procedures which are effected in parallel:

- electro machining to give the surface of the metal object a full free radical status

- hydro-dynamic coating of the surface of the metal object with the polymerisable composition of the present invention

- continuation of electro-machining of the surface of the metal object to accelerate and improve adhesion

The following processes occur:

1. Dirt is removed from the surface of the pipe and the original metal surface is exposed;

2. In the composition, free radicals form at the boundary with the metal and react with the metal surface, forming firm adhesive links;

3. As a result of formation of radicals and the heat evolved during electro-machining of the metal, the composition polymerises at the boundary with the metal; and

4. The composition is polymerised throughout the coating under the action of polymerisation initiators in the composition.

The principle of the present invention to creating a full free radical status on the surface of the material to which a chemically active adhesive composition is to be applied may be extrapolated to other areas and objects to provide an improved adhesive effect.

The way in which a free radical status may be created on the surface of a material to be glued depends on the particular material concerned. In the case of applying an adhesive composition to a metal surface, the free radical

status is created by electro-machining, or electro¬ mechanical brushing of the metallic surface to electrically charge the metallic surface, as described above.

In the case of applying adhesive to, for example, concrete, the free radical status may be obtained by including a particular additive in the adhesive composition which enables calcium to be extracted from the concrete. Use of the principle of the present invention in the case of concrete is particularly useful in the reinforcement of concrete blocks, for example, in roads, tunnels and structural building elements.

According to the present invention there is further provided a composition for reinforcing concrete, comprising phenyl glycidyl ester, having the general formula

C ₆ H ₅ - 0 - CH ₂ - CH - CH,

pyridine and a solidifying epoxide composition comprising epoxide oligomer and an amine curing agent.

An epoxide oligomer is a substance containing two or more primary amine groups. Pyridine is the aromatic compound C ₅ H ₅ N.

Phenyl glycidyl ester (FGE) and pyridine, adsorbed on the surface of the concrete pores, make them water- repellent and provide the conditions whereby water is displaced from the interior of the concrete block and replaced by the polymer composition.

The ingredients of a preferred composition are taken in the following proportions (in parts by weight) :

37

Epoxide oligomer 100

Amine curing agent 5 - 60

FGE 10 - 100

Pyridine 0.6-1.8

The composition is used by applying it to the surface of concrete constructions and buildings. If it is necessary to treat massive buildings, holes are bored in them and the composition is injected through them. The composition is most effectively used for impregnating a layer of corrosion on the reinforcing components of ferroconcrete constructions. In such cases, impregnation prevents further corrosion of the metal, strengthens the already-corroded metal and provides a firm link between the reinforcing components and the concrete body.

Rock is impregnated by injecting the composition through blast holes, whereas wooden articles and buildings are impregnated by applying the compositions to their surface.

When moist concrete is impregnated, the water in the pores of the concrete block prevents diffusion of the polymer composition throughout the concrete. The water- soluble pyridine and pehnyl glycidyl ether in the composition are adsorbed on the surface of particles of the concrete block and waterproof it and thus provide the conditions for selective adsorption of the composition and expulsion of water from the concrete. During the solification of the composition, the pyridine and phenyl glycidyl ether react with the epoxide oligomer and the amine curing agent, resulting in strong adhesion of the composition to the concrete. Consequently, activation of

the concrete surface in the present case is physico- chemical.

During the solidification process, all components of the composition become bonded in a single molecular network, which ensures that the resulting polymer is non¬ toxic even on contact with drinking water.

TABLE 3

LIST OF SPECIFIC INGREDIENTS OF THE COMPOSITION AND THE PROPORTIONS THEREOF IN THE FOLLOWING EXAMPLES

Cotaposltlon Oilgo Curing agen FGE: Pyridin. Niabar ϊyp» Quantity Tjrpa Quantity Quantity Quantity

Epoxlda-dlanll raaln, EV-20. MM 67.7 Pαlyathylana polyaαuna 10 21.3 410, apoxida numbar - 21.II MM - 120. K - 0.49

2 68 3 69 4 67 5 87

6 68 7 47 8 42 9 56 Trlathylana glycol d 10 48 Dlathylana tnaπunomathyl MW - 210. - 1.21

11 42 lαldazollne baaad on cabac c acid. MW - 336. K • 2.OS 12 40 Polyan noaαlda condanaatlon product of polyathylana polyaalne and dlαwr sad tαat yl aatara of fatty acids. MW - 430, K - 2.07

13 SO Dl(cyanosthy1)-dιat ylana 20 20.4 0.6 tria ina MW - 209. K - 1.62

14 1,2-apoxypropoxy-dlphanyl astai IS Polyathylana polyaalna 13.3 26 0.7 of athylana glycol CM ■ 304, apoxid* nu-abar - 24.51, epoxlda-dlanll rasln 30-20 45

15 Diglycyl aatar of raiorclnol 68 14 17

W - 210, apoxlda numb r - 33. Z

16 Trlglyeidyl attar of propylene glycol 14 12.1 0.9 MW - 490, apoxlda number - 14Z Epoxlda-dianll raain ED-20 64

Of course , the proportions of component given in the Table are for guidance only and skilled persons can adapt them to particular conditions under which the compositions are used.

When using the mixtures in Table 3, it should be remembered that:

Epoxide-dianyl resin and the polyethylene polyamine curing agent are very cheap,

Diethylene triaminomethyl phenol greatly increases the chemical stability of the impregnated materials and their resistance to solvents,

The use of 1,2 epoxypropoxy diphenyl ester of ethylene glycol, triglycidyl ester of propylene glycol and polyamine amide results in the maximum increase in the deformability of the impregnated materials, whereas the diglycidyl ester of resorcinol and diethylene triamino methyl phenol increases their strength, and

In the most slowly-solidifying compositions, which are needed for deep impregnation, the resin is 1, 2-epoxypropoxy diphenyl ester of ethylene glycol and the triglycidyl ester of propylene glycol, and the curing agent is polyamino amide.

Testpieces were made in order to determine the efficiency with which concrete was impregnated. To this end, a wet mixture of 4 parts sand and 1 part cement was placed in glass tubes. The mixture was compacted at a pressure of 10-15 kg/cm ² . After 30 days, the mixture in the tube was placed in water for 10 days, after which the excess water was poured off and a layer of composition 5 cm thick was poured on to the end of the testpiece. After 7 days, the testpiece was taken out of the tube and sawn into discs 1 cm thick, which were subjected to compression tests.

Table 4

The effect of impregnation on the strength of concrete

Example Composition Distance of Compressive

Number Number layer under strength, test from end kg/cur of testpiece, cm

1 1 1 1380

2 1 2 1220

3 1 3 1220

4 1 4 1205

5 1 5 1210

6 1 6 1205

7 1 7 1200

8 1 8 1200

9 1 9 1200

10 1 10 1180

11 1 11 1030

12 1 12 830

13 1 13 620

14 1 14 510

15 1 15 510

16 1 20 520

17 2 1 1420

18 2 2 1400

19 2 3 1390

20 2 5 1370

21 2 10 1310

22 2 20 530

23 3 1 1330

24 3 2 1300

25 3 5 1180

26 3 10 830

27 3 20 530

28 4 1 1210

29 4 2 1110

30 4 5 1100

31 4 10 1100

32 4 15 550

33 4 20 540

34 5 1 1200

35 5 2 890

36 5 5 550

37 6 1 930

38 6 2 720

39 6 5 550

40 7 1 940 41 7 2 920 42 7 5 920 43 7 10 900 44 7 15 760 45 7 20 600 46 8 1 620 47 8 2 570

Example 43

Concrete cylinders 15 mm in diameter were placed in water for a period not less than 1 month, and were than taken out of the water and the end of each cylinder was wiped with a wet cloth and a layer of composition number 9 was placed on it. After 1 hour, the composition was removed from the surface of the cylinder, using a dry cloth, and the cylinder was placed in a holder. After one day, the holder was placed in a device for supplying water through the cylinder at a pressure up to 8 atmospheres. Water was supplied from the non-impregnated end of the cylinder for five hours. The experiment showed that there was no observable penetration of water through the impregnated end of the cylinder at the end of the stated time.

Example 44

The bottom of a buried concrete tank containing reagents for disinfecting an accidental discharge of chlorine into a waterworks had become leaky, with the result that the contents of the tank were observed to be running into the ground, and ground water entered the tank during the spring. Experimental work was carried out on sealing the bottom of the tank. To this end, composition number 10 was applied to the wet bottom of the tank, using rollers. After a day, the tank was filled with chemicals.

Observations during a year showed that the bottom of the tank had been sealed by the impregnation.

Example 45

Composition number 12 for impregnating the inner surface was tested on a chamber measuring 6 x 6 x 6 metres, a concrete mock-up of the containment zone of damage to an atomic power station. The composition was applied twice with rollers at an interval of 3 hours. A week after application of the composition, the chamber was tested for sealing-tightness, by creating a vacuum of 0.01 mPa inside the chamber. Tests showed that after one day, the pressure inside the chamber had not increased by more than 0.005 mPa.

Example 46

Composition number 13 was tested by impregnating moulded concrete decorations in a garden and park complex, with the object of preventing them from further damage. To this end, 15% toluene was added to the composition in order to reduce its viscosity. The composition was applied from a sprayer. The air temperature during the work was 24°C.

Observations over the course of a year showed that deterioration of the moulded decorations stopped after they were impregnated.

A control sample or blank was treated by the method described and underwent 100 test cycles (moistening, freezing and drying) without deterioration.

Example 47

Composition number 14 was tested for strengthening damaged brickwork and protecting it from further deterioration. As a control, the composition was applied to pieces of damaged brick, using a sprayer, and they were then placed in water for 1 day and then in a freezer at a temperature of -15C for one day and finally in a drying chamber at 60C for 1 day.

During 100 test cycles there were no visible signs of damage to the bricks.

Example 48

Composition number 15 was tested for use as a material for impregnating the concrete floor of a champagne factory. The mosaic concrete floor quickly lost strength and deteriorated at the places where champagne fell on it. The composition was tested by preparing concrete cubes measuring 10 x 10 x 10 cm. The cubes were wetted and impregnated twice with the composition after an interval of 1 day. Three days after the last impregnation, the cubes were placed in a tank containing champagne. Tests during a month showed that the untreated cubes lost 73% of their strength whereas the treated cubes lost only 4.6%.

Example 49

Composition N16 was used to impregnate splint-slab boards in order to increase their resistance to liquid and gaseous media from cattle-breeding establishments. The composition was applied to one surface of the board by a roller, and after impregnation with the composition a second layer containing pigments was applied.

Three days after application of the coating, an enclosing rib was formed on the surface of the board and pig's urine was poured inside. Observations during a month showed that the urine did not have any destructive effect on the board, whereas the untreated board was destroyed in two days.

Another example where the principle of the present invention may be applied is in the case of applying adhesive to sawdust or other waste materials from agricultural products such as rice, kaoryang husk and straw etc. The adhesive acts as a binding agent to create particle/chipboard. The particle/chipboard can then be used in the manufacture of furniture, shelving and other products. This not only provides the obvious advantage of being able to use woodworking waste/wet waste or agricultural waste in the production of marketable products, but, by following the principle explained above and creating a free radical status to improve adhesive strength, the previously used binding material which was toxic can now be replaced with, for example, non-toxic polymerisable compositions according to the present invention. Furthermore, by using the principle of the present invention, only 2% polymer is needed for 98% sawdust in weight, which can be wet, whereas previously, a minimum of 15% polymer was needed and the sawdust also had to be completely dry.

According to the present invention there is further provided a binding material comprising an organic component comprising a polyisocyanate, a hardening agent and an inorganic salt. The non-organic salt is for binding the humidity and strengthening of the end product. Such a binding material may be used for binding sawdust and agricultural waste so that the end product is again stronger, non-toxic and economically safe and does not

require an additional protective coating for use in open air. Only a reduced amount of binding material is, again, required and sawdust and agricultural wastes having humidity up to 40% can be used.

Preferably the hardening agent comprises water glass. More preferably the inorganic salt is calcium hydroxide. Most preferably the organic component comprises a polyisocyanate and a polyester containing polyethylene oxide monomeric units.

The term "polyisocyanate" includes substances selected from:

Non-purified intermediate from production of 4,4' diphenyl methane diisocyanate;

Bottoms from production of toluylene diisocyanate.

The term "polyester" includes products selected from the group of products of a reaction between di- and triethylene glycol, glycerol, tri ethylol propane, pentaerythritol, castor oil derivatives and other polyols, and adipic, phthalic, maleinic and other dibasic acids.

The term "polyethylene oxide monomeric units" relates to a fragment of a molecule containing at least two oxyethylene groups in its composition.

The present invention further provides a method for mixing a filler with a binder according to the present invention wherein the filler is initially mixed with the hardening agent, subsequently with the inorganic salt and then finally with the organic component.

7 1

47

The present invention further comprises a method of producing compression moulded articles comprising moulding a mat of a filler with a binder according to the present invention and hot compression moulding the mat in a temperature range of 60 - 100°C. It is preferred that the filler is not previously subjected to drying.

In one embodiment of the invention an oligomer is introduced into the polyisocyanate composition, the oligomer comprising a polyester with polyoxyethylene fragments in the chain, applied with a dispersion of calcium hydroxide (lime paste) in water, and a solution of sodium silicate (water glass) .

When the proposed composition is used, a high rate of solidification of the binder is achieved at a temperature of 60 - 100°C due to interaction between the isocyanate groups of polyisocyanate with one another, with water and with the hydroxyl groups of the polyester.

The solidification process is catalysed by anions and cations of calcium and sodium hydroxide.

A high degree of dissociation of bases and salts of calcium and sodium is obtained by means of pseudo-crown ethers - oxyethylated fragments of the polyester chain formed during hydrolysis of ester groups in the oligoester - which forms a loose ion pair. This hydrolysis occurs at high speed on contact of the polyester with particles of calcium hydroxide. Also calcium hydroxide in the system in question is a cross-linking agent which reacts at high speed with the carboxyl groups in the oligomer formed during hydrolysis of ester groups. This is sufficient to ensure that the woodchip board retains its shape even at

very low rates of conversion of isocyanate groups, particularly when branched polyesters are used.

At a temperature below 25°C, on the other hand, the described sequence of chemical reactions in the binder fail or practically fail to occur owing to the low rate of hydrolysis of the ester groups in the polyester. This prolongs the working life (suitability for compression moulding of articles) of the sawdust and the binder applied to it.

Preferably the ingredients are present in the following proportions (parts by weight) per 100 parts by weight of polyisocyanate:

Polyester 20 - 200 Lime paste 20 - 200 Water glass 20 - 200

The wide range of proportions of ingredients of the composition is due to differences in the type of fillers, their moisture content, the selected compression-moulding conditions, and the properties required from the finished articles.

The polyester used may comprise products of a reaction between di- and triethylene glycol, glycerol, trimethylol propane, pentaerythritol, castor oil derivatives and adipic, phthalic and maleinic acid.

In one method of the present invention, the components of the composition water glass, lime paste, polyester and polyisocyanate, are successively applied to the wood filler.

In this method, applying water glass, which reacts with a solution of calcium hydroxide, causes a layer of calcium salt of silic acid to form around the particles of wood filler and prevent the binder components from diffusing throughout the particles of wood binder. At the same time, sodium hydroxide formed during the reaction diffuses deeply into the particles of filler and plasticises the cellulose, so that it can be shaped when the articles are pressed. When the binder solidifies, the isocyanate groups react with water, and carbon hydroxide evolved during the reaction inactivates the sodium and calcium hydroxide.

Compression-moulding is brought about at a temperature of 60 - 100° and the filler is not dried before pressing.

It is desirable to use a filler with a moisture content equal to the equilibrium moisture in the wood under the conditions where the woodchip board is used. This prevents deformation of the compression-moulded articles after prolonged use.

Other features of the proposed group of inter-related inventions will be clear from the detailed description of the method of producing compression-moulded articles.

The press compositions are specified in Table 5 and the physical and mechanical properties of test-pieces are given in Table 6.

BINDER COMPOSITIONS, IN PARTS BY WEIGHT

Composition number

Ingredients

I 3 4 5 6 7 8 9 10 11 12 13 14 15

Polyisocyanate (crude MDI) lOO 100 100 100 100100 100 100100 100100 100 100 100 100 1

- , -dιphenyl methane diisocyanate)

Polyisocyanate - bottoms ι from production of toluylene 100 .diisocyanate

Polydiethylene glycol 25 20 10 50 100200 250 adipate triol, MW = 2200

Polydiethylene glycol 25 adipate diol ^" , MW = 800

Polydiethylene glycol 25 aleinate phthalate, MW 1 00

Table

EXAMPLES OF TECHNOLOGICAL PRODUCTION PARAMETERS OF COMPRESSION-MOULDED ARTICLES A D PiiϊSICAI AND MECHANICAL PROPERTIES

CM CM

I -

M o o o I- O — CM I- _,

: t iM s lO CO m OO CO i ' lO CM

— -' ^• CM CM CM — — < CM c M — - ' CM CO

\

CC CM CM CO O

CD O O O O O O O O O O O O O O O m i.o in 10 m m in m >o in in in m in m

^• t -t -c m in IΛ m 10 m ID m in m in ιo

O O O O O O O O O O O O O O O

CN _t o r- ^■ -"-' < _f M- _H i _p _n _l e _p _o r_- c_o _H o _r _ _< o ₀₁ o _CV J o _{(: 1} ^■ ₍ — _: *<

^• -^ C ^{\) C} 0 -t l0 0 t-- C O O -H (M C -+ lΩ CM CM CM CM CM (M CM CM CM CO CO CO co co CO

When using the component listed in Tables 5 and 6, it is desirable to bear in mind that:

- the water from production of poluylene isocyanate, the sugar industry and paper-board production is very cheap;

the polyester containing ethylene glycol does not serve as a pseudo-crown ester; the fragment of diethylene glycol therein, more particularly tri- and polyethylene glycol, is itself sufficient to form loose ion pairs, resulting in catalysts of isocyanurate structures and consequently improving the physical and mechanical characteristics of the pressed articles.

The physical and mechanical properties of pressed test-pieces were determined by the following methods:

density - to GOST 15139-69; bending strength at break - to GOST 4648-71; elasticity modulus during bending - to GOST 9550-81; compressive strength at break - to GOST 4651/82; impact strength - to GOST 4647/80; water adsorption in 24 hours - to GOST 4650-80.

Known special purpose additives, i.e. paraffin, dyes, pigments, fire-proofing compounds, toxic chemicals, etc. - were introduced into the composition in order to standardise parameters of the pressed articles such as the water adsorption, colour, combustibility and resistance to decay or damage by insects and rodents.

Example 50

Water glass (2 parts by weight) (GOST 13078/81) , silicate liquor ratio 2.8, followed successively by lime paste (1 part by weight), polyethylene glycol adipate triol, MW = 2200 (0.25 parts by weight) and polyisocyanate (crude MDI), (0.75 parts by weight) were applied to the surface of a mixture of birch and poplar sawdust (100 parts by weight) , using an atomiser.

The fineness of the sawdust was 1 - 4 mm and the moisture content was 20%.

To reduce the water adsorption, the sawdust was mixed with paraffin powder in the proportion 90:10.

The resulting crude mixture was compressed to form patterned decorative wall panels. To this end, moist oak veneer was stuck to one surface of the moulding.

The crude mixture was formed into a mat and compressed at a temperature of 90°C for 5 minutes. The resulting article measured 600 x 600 x 5 mm.

The resulting article has the following physical and mechanical properties:

density - 860 kg/m ³ ; - swelling after 24 hours in water - 7.2%; toxicity (presence of isocyanates, formaldehydes, etc) - depends of choice or original wood; maximum strength on static bending - 160 (220) kg/cm ₂ ; elastic modulus when bent - 15 780 (21 300) kg/cm ² ; compressive strength at break - 142 kg/cm ² ; impact strength - 5.6 kJ.

Example 51

Water glass, silicate liquor ratio 3.0 (3 parts by weight) followed successively by lime paste (5 parts by weight), a mixture of a , ω methacryl (bis-triethylene glycol) phthalate (0.5 parts by weight), a 30% solution of bottoms from production of toluylene diisocyanate in fireproofed trichloroethyl phosphate (20 parts by weight) and polyisocyanate based on MDI (10 parts by weight were applied to the surface of waste from hemp production, using an atomiser.

The fineness of the waste was 2 - 5 mm and the moisture content was 5%.

The resulting crude mixture was pressed to form a panel board floor. To the end, a patterned prefabricated veneer of oak, beech, hornbeam and birch was applied to one surface of the moulding. In order to secure the veneer components of the floor to one another and increase the adhesion of the veneer to the compressed waste, an adhesive made by mixing the previously-mentioned binder components was applied to the inner surface of the veneer.

The floor panels were pressed at a temperature of 90°C, at a specific pressure of 50 kg/cm ² and for 10 minutes.

The resulting articles had the following physical and mechanical properties.

density - 920 kg/m ³ ; swelling after 24 hours in water - 5%; toxicity - depends on choice of the original hemp waste;

maximum strength under static bending - 640 kg/cm ² ; elasticity modulus when bent - 68,000 kg/cm ² .

Example 52

Water glass, silicate liquor ratio 2.8 (0.5 parts by weight) followed in succession by lime paste (0.5 parts by weight) , polyethylene glycol adipate triol, molecular weight 2200 (0.3 parts by weight) and polyisocyanates (0.7 parts by weight) were applied to the surface of conifer sawdust (100 parts by weight) using a high-speed agitator.

The fineness of the sawdust was 1 - 10 mm.

The resulting crude mixture was pressed to form multi¬ layer panels for building. Compression-moulding was brought about at a temperature of 90°C, specific pressure 50 kg/cm ² . Duration of pressing - 10 minutes. Thickness of pressed sheet - 200 mm.

The pressed sheets had the following physical and mechanical properties:

density - 820 kg/m ³ ;

water penetratability - 0.5 g/m ² /day;

toxicity - panels permitted for use in residential environment;

breaking strength under compression - 110 kg/cm ² .

In order to manufacture the panels, a strong liquid foam plastic was poured into the gaps between 3 sheets 20

mm thick. After the foam plastic had hardened, the outer sides of hepanel were impregnated with a mixture of polyol and polyisocyanate to a depth of 1 -2 mm. The total thickness of the 3-ply panel was 100 mm.

Example 53

Water glass with a silicate liquor ratio of 3.0 (0.5 parts by weight) followed in succession by lime paste (0.3 parts by weight) , polyethylene glycol adipate triol, molecular weight 2200 (0.3 parts by weight) and polyisocyanate (0.7 parts by weight) were applied to the surface of conifer sawdust (100 parts by weight) using a high-speed agitator.

The fineness of the sawdusts was 2 - 4 mm.

The resulting crude mixture was pressed in a step-by- step press in order to produce a continuous block, cross- section 25.5 x 14.5 cm. Compression-moulding was brought about the cyclic feed of the crude mixture to a heated die which was compressed by a punch equipped with a projecting part for forming a cavity in the block. The size of the cavity was 20 x 8 cm. After the block had been shaped, the cavity was filled with heat-insulating material.

The block was pressed at a temperature of 90°C. The force on the punch was 20 t and the speed of shaping the block was 30 m/h.

When the block was being shaped, a mixture of polyisocyanate (100 parts by weight), trichloroethyl phosphate (30 parts by weight) and pigments (50 parts by weight) was supplied to the gap formed during the production process. The mixture served as a lubricant and,

after hardening, formed a fire-resistant, decorative, strengthening and moisture-resistant layer.

The block had the following physical and mechanical properties:

density - 950 kg/m ³ ;

water permeability - 0.4 g/m ² /day;

- toxicity - use permitted in a residential environment;

breaking strength on compression along axis of block - 43,000 kg/cm ² .

Other applications of the principle of the present invention envisaged include making ply-wood from moist veneer, the manufacture of decorative tiles and plates, reinforcement of the strength of any soft wood materials consolidation of earth, particularly in muddy sites and the gluing of solid fuel to space rockets.

Thus, it can be seen that the polymerisable compositions of the present invention have a very wide range of uses, including, for example:

- metal repair works in situ, whether in the open air, under water, or in an oily environment

- cementing under any weather conditions, without the need for careful preparation of surfaces to be cemented, removal of corrosion, moisture, petroleum stains from surfaces or de-greasing, etc.

- adhesive joining to give high in-service joint strength under variable conditions, including moist and oily environments, wide temperature ranges and exposure to vibratory and impact loads.

sealing underwater main line pipes by coating unsound areas in pipe line walls

- jointing of underwater pipelines

- water proofing and strengthening of underground and underwater pipelines by laminating polymerisable compositions of the present invention on to the pipelines using specially designed equipment

- sealing and anti-corrosive protection of metallic and concrete tanks by applying polymerisable compositions of the present invention to internal and/or external surfaces

- reconditioning housings of pump pressure chambers damaged by cavitation and hydro-abrasive effect of pumps liquid

thermal insulation of tanks and pipelines transporting hot petroleum products

- protection and reinforcement of internal surfaces e.g. oil, gas, aggressive liquid, and drinking water pipes, including application of coatings in situ in plant or field conditions, without removal of the pipelines from operation

- ship repairs, including reconditioning of original strength and stiffness, water leakage stoppages and

anti-corrosive protection of damaged metallic structures and equipment

repair and anti-corrosive protection of ship pipelines

painting of ships and boat bodies while still underwater and in a wide temperature range (e.g. 5 to + 60°C)

- emergency repairs of ship engine housings

Set out below are specific examples of polymerisable adhesives manufactured according to the present invention and some of their properties and preferred uses.