WO2004085509A1

WO2004085509A1 - Process for the manufacture of foams composed of polyurethane or of modified polyurethane

Info

Publication number: WO2004085509A1
Application number: PCT/EP2004/003236
Authority: WO
Inventors: Pierre Dournel; Véronique Mathieu
Original assignee: Solvay (Société Anonyme)
Priority date: 2003-03-24
Filing date: 2004-03-24
Publication date: 2004-10-07

Abstract

Foams composed of polyurethane, in particular of polyisocyanurates, having class B2 flame resistance are obtained via reaction of polyols and of isocyanates in the presence of a catalyst, of a polyepoxide and of a blowing agent other than a chlorofluorocarbon, particularly an HFC and/or a flammable blowing agent, such as n-pentane.

Description

Process for the manufacture of foams composed of polyurethane or of modified polyurethane

The present application claims the benefit of US patent application Ser. No, 60/464,490 filed April 22, 2003- incorporated herein by reference. The present invention relates to a process for the manufacture of foams composed of polyurethane or of modified foams composed of polyurethane, to these foams, and to certain materials suitable for use in the process.

Further to worries concerning the potential harmful effect on the stratospheric ozone layer of the chlorofluorocarbons (CFCs) used previously as blowing agents in the manufacture of polyurethanes, industry is experiencing pressure to use blowing agents other than CFCs.

The change of blowing agent necessitates new formulations permitting cost-effective production of foams composed of polyurethane having satisfactory properties, particularly in relation to dimensional stability, adhesion to supports, thermal conductivity and fire resistance. In particular it should be noted that the chlorofluorocarbons have an intrinsic effect in increasing fire resistance, whereas this is not generally the case for the alternative blowing agents envisaged. ,

The patent application US 2002/0019452 discloses in its example 4 that foams composed of polyisocyanurate having a class B2 fire resistance can be obtained using certain polyalkylene oxide diols with known flame retardants and with CO₂ produced via hydrolysis in situ of the isocyanate as blowing agent.

The object of the invention is to solve the abovementioned problems.

The invention therefore provides a process for the manufacture of foams composed of polyurethane or of modified polyurethane in which at least one polyol is reacted with at least one isocyanate in the presence of a catalyst, of a polyepoxide and of a blowing agent other than a chlorofluorocarbon, in particular an HFC and/or a flammable blowing agent.

Surprisingly, it has been found that the process according to the invention can give foams in accordance with class B2 with a large range of blowing agents, among which are flammable blowing agents. The foam obtained generally has a flame height below 15 cm (foam B2 or E) when it is subjected to the test in the standard DIN 4102 or EN ISO 11925-2. The foam obtained often has a flame height below or equal to about 13 cm. It is even possible to produce a foam having a flame height below or equal to about 10 cm. A flame height below or equal to about 8 cm has also been obtained, even with flammable blowing agents. In particular with hydrofluorocarbon blowing agents or hydrofluorocarbon blowing agent compositions, a flame height below or equal to about 6 cm, sometimes equal to about 5 cm has also been obtained. It is understood that the inventive teaching enables the skilled person to use and adapt the invention also if other flammability standards in particular aiming at similar objectives as the standards explicitly cited herein, were applied. The foams obtained have particularly good adhesion to supports such as metals, walls, e.g. concrete walls, glass and wood. This effect is also present when the support surface is not heated and is found, for example, at a temperature below or equal to about 20°C. The presence of the polyepoxide permits the viscosity of the mixture of reactants to be reduced.

Polyurethane means polymers derived essentially from the reaction of polyols and of isocyanates. These polymers are typically obtained from formulations whose isocyanate index is from 100 to 180.

Modified polyurethane means polymers derived from the reaction of polyols and of isocyanates which contain, besides urethane functions, other types of functions, in particular triisocyanuric rings formed via trimerization of isocyanates. These modified polyurethanes are usually termed polyisocyanurates. These polymers are typically obtained from formulations whose isocyanate index is from 180 to 450.

All the isocyanates traditionally used to manufacture these foams may be used in the process according to the invention. By way of examples, mention may be made of aliphatic isocyanates, such as hexamethylene diisocyanate and aromatic isocyanates, such as tolylene diisocyanate or diphenylmethane diisocyanate.

For the purposes of the present invention, "polyol" means any compound . containing at least two functional groups reacting with isocyanates. These functional groups contain at least one active hydrogen atom as defined by the Zerewittinoff reaction. The active hydrogen atom is generally a hydrogen atom bonded to an oxygen, nitrogen or sulphur atom. The polyols which may be used in the process according to the invention particularly comprise polyether polyols and polyester polyols.

In one preferred embodiment, the structure of the polyol is essentially free from phosphorus. Particular examples of polyether polyols may be obtained via reaction of alkylene oxides with an initiator compound containing at least two functional groups containing at least one active hydrogen atom, as defined above.

By way of example, initiator compounds may be selected among polyalcohols, polyamines, amino alcohols and thiol alcohols. Among the polyalcohols particular mention is made of ethylene glycol, glycerol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 2-butyne-l,4-diol, 2,3 -dibromo-2-butene- 1,4-diol, trimethylolpropane, triethanolamine, pentaerythritol, sorbitol and sucrose.

Among the polyamines particular mention is made of diethanolamme, ethylenediamine, triethylenediamine, tolylenediamine and diaminodiphenylmethane.

Among the amino alcohols particular mention is made of ethanolamine and diethanolamine.

Among the thio alcohols particular mention is made of mercaptoethanol. Particular examples of polyether polyols may be obtained via condensation of polyols, in particular of glycols with an initiator compound containing at least two carboxylic groups or via reaction of this initiator compound with ethylene oxide and/or propylene oxide. Phthalic or terephthalic acid is preferred as carboxylic acid initiator. The structure of the polyols is preferably free from phosphorus. They may optionally contain halogens, for example in particular chlorine and/or bromine. Their structure may also be essentially free from halogens.

In the process according to the invention, the catalyst may comprise a compound catalyzing the formation of the urethane -NH-CO-O- bond, via reaction between a polyol and an isocyanate or activating the reaction between an isocyanate and water, for example tertiary amines and organic compounds of ■ tin, of iron, of mercury or of lead. Tertiary amines which may particularly be mentioned are triethylamine, N,N-dimethylcyclohexylamine (DMCHA), N-methylmorpholine (NMM), N-ethylmorpholine, dimethylethanolamine, diaza[2.2.2]bicylcooctane (triethylenediamine) and substituted benzylamines such as N,N-dimethylbenzylamine (DB). Organic compounds of tin or of lead which may be particularly mentioned are dibutyltin dilaurate, stannous octanoate and lead octanoate.

In particular if the object is the manufacture of foams composed of modified polyurethanes (polyisocyanurates), the catalyst may also comprise a compound catalyzing the trimerization of the isocyanates to give triisocyanurates. Specific examples of these catalysts are selected among sterically hindered amines, such as diazabicyclooctane, and among ammonium salts. Use may be made of a mixture of a plurality of catalysts.

In the process according to the invention, the polyepoxide contains at least two epoxy functions. The polyepoxide generally contains at most 6 epoxy functions. When a foam composed of polyurethane is produced, the polyepoxide preferably contains 5 or 6 epoxy functions. When a foam composed of polyisocyanurate is produced, the polyepoxide preferably contains 2 or 3 epoxy functions.

In the process according to the invention, the polyepoxide generally contains a number of carbon atoms at least equal to 8. The polyepoxide often contains a number of carbon atoms at least equal to 11. The polyepoxide preferably contains a number of carbon atoms at least equal to 13.

In the process according to the invention, the polyepoxide generally contains a number of carbon atoms at most equal to 96. The polyepoxide often contains a number of carbon atoms at most equal to 42. The polyepoxide preferably contains a number of carbon atoms at most equal to 20.

The polyepoxide may contain certain functional groups or substituents, such as in particular halogens, preferably selected among chlorine and bromine, aromatic groups, or triple or double bonds. It is particularly preferable for the polyepoxide to contain bromine or a triple bond.

In one preferred embodiment, the polyepoxide is obtainable via a reaction of epichlorohydrin with an initiator compound as described above containing at least two functional groups, each of the functional groups containing at least one active hydrogen atom. The initiator compounds generally contain 2, 3, 4, 5 or 6 functional groups. The initiator compound is preferably selected among the, optionally brominated, polyalcohols, particularly preferably among the polyalcohols described above. It is still more particularly preferably selected among 1,4- butanediol, 2-butyne-l,4-diol and 2,3-dibromo-2-butene-l,4-diol. The polyalcohol may also be selected among the polyester polyols or the polyether polyols such as those described above. In one particular embodiment, the polyalcohol is a polyester polyol obtainable via a reaction of phthalic acid or of a brominated phtalic acid such as 3,4,5,6-tetrabromophthalic acid with about 2 equivalents of ethylene oxide and about 1 equivalent of propylene oxide. In the preferred embodiment, the polyepoxide is generally obtainable via the reaction of the initiator compound with from 1 to 5 equivalents of epichlorohydrin per functional group of the initiator compound. In a first particularly preferred variant, the polyepoxide is obtainable via the reaction of the initiator compound with about 1 equivalent of epichlorohydrin per functional group.

In a second particularly preferred variant, the polyepoxide is obtainable via the reaction of the initiator compound with at least about 1.2 equivalents, in particular with at least about 1.25 equivalents, of epichlorohydrin per functional group. In this variant, the polyepoxide is obtainable via the reaction of the initiator compound with at most about 3 equivalents, in particular with at most about 2 equivalents, of epichlorohydrin per functional group. Of course, each of these variants may be combined with each of the abovementioned initiator compounds.

By way of example, the polyepoxides may be obtained via the reaction of the initiator compounds with epichlorohydrin in the presence of a Lewis acid, such as BF₃.Et₂O followed by a cyclization in a basic environment, in particular in the presence of a slight excess of a strong base, such as sodium hydroxide.

An alternative way of obtaining in particular the polyepoxide derived from polyester polyol obtainable via a reaction of phthalic, acid with about 2. equivalents of ethylene oxide and about 1 equivalent of propylene oxide as described here before, comprises reacting the polyalcohol with an allylic derivative such as allyl chloride followed by epoxidation of the double bond.

The invention also provides the polyepoxides in accordance with the above description.

It has been found that the polyepoxides according to the invention have particularly good properties for reducing the viscosity of reaction mixtures in the process according to the invention and for increasing the solubility of the blowing agent in these mixtures.

In a further particular embodiment, a monoepoxide derived for example from aromatic, optionally brominated alcohols, such as 2,4,6-tribromophenol or tribromoneopentlyalcohol in particular tris(bromomethyl)ethanol is used. Particular examples of these monoepoxides correspond to the formula

In which Rβ_r - O is a radical corresponding to a brominated alcohol such as described here before. In the process according to the invention, the blowing agent is not a chlorofluorocarbon. Of course, the blowing agent may be a mixture of a plurality of compounds. By way of example, appropriate blowing agents are selected among CO₂, which may be formed in situ via reaction of the isocyanate with water, hydrocarbons, ethers and ketones, optionally fluorinated, for example alkanes, hydrofluo oalkanes, hydrochlorofluoroalkanes, dialkyl ethers, and hydrofluoro ethers. In one particular embodiment, use is made of a blowing agent comprising an HFC and/or a flammable compound. "Flammable blowing agent" means in particular a compound which has a flash point according to the standard ISO 1523.

Surprisingly, it has been found that the process according to the invention can give foams complying with class B2 as described above even when use is made of a flammable blowing agent which increases the flammability of the foam.

The flammable blowing agent preferably comprises at least one compound selected among hydrocarbons, in particular alkanes, alkyl ethers and hydrofluoroalkanes.

As hydrocarbon an alkane, in particular containing 5, 6 or 7 carbon atoms is often used. Particular examples of hydrocarbons are selected among pentanes, hexanes, such as n-hexane or isohexane, and heptanes, such as n-heptane. Preference is given to a pentane selected in particular among n-pentane, isopentane, neopentane and cyclopentane. n-pentane is very particularly preferred.

As hydrofluoroalkane a hydrofluoroalkane comprising a hydrofluoroalkane having a numeric F/H ratio less than or equal to 1 is often used. Specific examples of hydrofluoroalkanes are selected among difluoromethane (HFC-32), 1, 1-difluoroethane (HFC-152a) and 1,1, 1,3,3- pentafluorobutane (HFC-365mfc). 1,1,1,3,3-pentafluorobutane is preferred.

In one variant, the: blowing agent comprises a non-flammable hydrofluoroalkane. Examples of such hydrofluoroalkanes are 1,1,1,2- tetrafluoroethane, 1,1,1,3,3-pentafluoropropane (HFC-245fa), 1,1,1,3,3,3- hexafluoropropane (HFC-236fa) and 1,1, 1,2,3,3, 3-heptafluoropropane (HFC-

227ea). The preferred non-flammable blowing agent is 1,1,1,3,3- pentafluoropropane.

As alkyl ether, a dialkyl ether containing from 1 to 4 carbon atoms in each of the alkyl chains is often used, for example dimethyl ether or diethyl ether. In one particular variant, the blowing agent comprises a composition, preferably azeotropic or pseudoazeotropic, of 1,1,1,3,3-pentafluorobutane with at least one pentane or hexane, these being as described above. Particular compositions of HFC-365mfc with these hydrocarbons which may be used in the process according to the invention -are described in patent US 6,303,668 in the name of the applicant.

In a second particular variant, the flammable blowing agent comprises a composition of 1, 1, 1,3,3-pentafluoropropane with at least one pentane or hexane, these being as described above. The pentane is preferably the pentanes described above.

Other than the polyol, the blowing agent and the catalyst, use may be made in the process according to the invention of various additives conventionally used for preparing foams composed of polyurethane or of modified polyurethane, examples being in particular water, surfactants, antioxidants, flame retardants and/or pigments.

The use of a flame retardant is preferred in the process according to the invention. By way of example, it is possible to use flame retardants comprising bromine or phosphorus. By way of example, brominated flame retardants are selected among brominated polyols, such as in particular IXOL® Ml 25 brominated polyol or IXOL® B251 brominated polyol, these being marketed by the applicant.

The use of a flame retardant containing phosphorus, optionally with a brominated flame retardant as described above is preferred. Specific examples of flame retardants containing phosphorus are selected among triethyl phosphate (TEP), diethyl ethylphosphonate (DEEP), dimethyl methylphosphonate (DMMP), trichloropropyl phosphate (TCPP) and trichloroethyl phosphate (TCEP). Trichloropropyl phosphate (TCPP) is preferred. When use is made of a flame retardant containing phosphorus, the amount used of this material is generally such that the phosphorus content in the foam is at least 0.1% by weight. The amount is often such that this content is at least 0.2% by weight. The amount is preferably such that this content is at least 0.3% by weight. When use is made of a flame retardant containing phosphorus, the amount used of this material is generally such that the phosphorus content in the foam is at most 2% by weight, in particular at most 1% by weight. The amount is often such that this content is at most 0.6% by weight. The amount is preferably such that this content is at most equal to or less than about 0.5% by weight. Use of the retardant in the specified amount gives particularly good results with the flammable blowing agents described above.

The proportions of polyol, of catalyst, of blowing agent and of optional additives in the process according to the invention vary, particularly according to the application, the type of foam prepared, the nature of the polyol and the nature of the catalyst. In practice, the amount of catalyst or of mixture of catalysts used generally varies from about 0.05 to 10 parts by weight per 100 parts by weight of polyol. The amount of blowing agent is generally from 1 to 80 parts by weight per 100 parts by weight of polyol. It is preferably from 10 to 60 parts by weight per 100 parts by weight of polyol. The amounts of water, of surfactants or of plastifiers are those traditionally used for preparing foams composed of polyurethane or of modified polyurethane.

In the process according to the invention, the amount polyepoxide or optionally the monoepoxide which is used is generally at least 1 wt.% relative to the weight of the polyol mixture consisting of polyol and polyepoxide and/or optionally monoepoxide. Often, this amount is at least 15 wt. %. More, often, this amount is more than 17 wt. %. Preferably, this amount is equal to or greater than 20 wt. %. More preferably, this amount is equal to or greater than 25 wt. %. In the process according to the invention, the amount polyepoxide or optionally the monoepoxide which is used is generally at most 90 wt.% relative to the weight of the polyol mixture consisting of polyol and polyepoxide and/or optionally monoepoxide. Often, this amount is at most 80 wt. %. Preferably, this amount is equal to or less than 50 wt. %. More preferably, this amount is equal to or less than 35 wt. %.

Particularly good results for the manufacture of flame resistant foams have been obtained with a combination of a polyepoxide, in particular in the preferred amounts specified here before with a flame retardant as described above, in particular a flame retardant containing phosphorus, preferably in the preferred amounts specified above. A synergistic effect concerning flame height in the B2 test can be obtained, offering extremely good performances especially with flammable blowing agents or HFC-containing blowing agents.

In a particular embodiment of the process according to the invention, a melamine resin may also be used. In this case the amount of melamine resin used is generally less than 15 wt.% relative to the weight of the mixture of melamine resin, polyol, polyepoxide and/or optionally monoepoxide. Often this amount is less than 5 wt%.

In the process according to the invention, it is preferred that melamine resin is substantially or totally absent. The foams obtained are often rigid foams. The process according to the invention is preferably applied to obtain closed-cell foams whose content of closed cells is generally at least 90%. These foams are particularly useful as thermal insulation materials. It is particularly preferable to obtain polyisocyanurate foams.

The foams composed of polyurethane, in particular the polyisocyanurate foams, may be produced by various methods capable of industrial-scale use. Mention may be made particularly of spraying, inj ection into a mould held under pressure, casting to produce slabs according to a batchwise or continuous process, or the twin-belt system with flexible or rigid faces.

The invention also provides the foams composed of polyurethane and obtainable by the process according to the invention. The invention also provides a method of manufacture of a supported foam composed of polyurethane or a supported modified foam composed of polyurethane, according to which

(a) a layer of polyepoxide in accordance with the description above is deposited on at least one part of a solid support; (b) a mixture which comprises reactants and which is appropriate for operating the process according to the invention is deposited at least on the layer of polyepoxide;

(c) the deposited mixture comprising reactants is reacted according to the process according to the invention. By way of example, solid supports are chosen among metals, walls, such as concrete walls, glass and timber.

The examples below are non-limiting illustrations of the invention. Example 1 - Manufacture of a polyepoxide from 2-butyne-l,4-diol One mol of 2-butyne-l,4-diol was condensed with 3 mol of epichlorohydrin in the presence of a Lewis acid (BF₃.etherate). The chlorohydrin obtained was dissolved in a 2: 1 by weight dichloromethane/methanol mixture. 2.2 mol of a 10 N solution of NaOH were added over 30 minutes. After all of the sodium hydroxide had been introduced, the mixture was held at 40°C for a period of 60 minutes, with vigorous stirring. The reaction mixture was cooled and then extracted with water. The polyepoxide was isolated by distillation and had 2 epoxy functions and a degree of epichlorohydrin condensation of 1.5 per hydroxy group.

Example 2 - Manufacture of a polyepoxide based on 2,3-dibromo-2- butene-l,4-diol Method A: The polyepoxide is obtained by a method analogous to example 1, selecting 2,3-dibromo-2-butene-l,4-diol obtained by bromination of 2-butyne-l,4-diol. Method B: An addition reaction was carried out between one equivalent of bromine and the polyepoxide obtained in example 1.

Example 3 : Manufacture of a PIR foam

Use was made of a polyol mixture comprising 97 g of STEPANPOL 2352 polyester polyol, 30 g of polyepoxide obtained according to example 1, 22 g of ARCOL 3758 polyether polyol, 30 g of TCPP, 2.25 g of silicone surfactant, 0.75 g of dimethylcyclohexylamine (DMCHA), 4.5 g of DABCO TMR (diazabicyclo[2.2.2]octane), 1.0 g of water and 32 g of n-pentane. This mixture was then brought into contact with 379 g of polymeric MDI (DESMODUR 44V20) to obtain a foam composed of rigid polyisocyanurate. Evaluation of the fire behaviour of this foam according to the DIN 4102 test gave class B2 with a flame height of 12 cm.

Example 4: Manufacture of a PIR foam

Use was made of a polyol mixture comprising 97 g of STEPANPOL 2352 polyester polyol, 30 g of polyepoxide obtained according to example 2, 22 g of ARCOL 3758 polyether polyol, 30 g of TCPP, 2.25 g of silicone surfactant, 0.75 g of dimethylcyclohexylamine (DMCHA), 4.5 g of DABCO TMR (diazabicyclo[2.2.2]octane), 1.0 g of water and 32 g of n-pentane. This mixture was then brought into contact with 379 g of polymeric MDI (DESMODUR 44N20) to obtain a foam composed of rigid polyisocyanurate. Evaluation of the fire behaviour of this foam according to the DIN 4102 test gave class B2 with a flame height of 12 cm.

Example 5 - Manufacture of a PIR foam with high amount of water

Use was made of a polyol mixture comprising 84 g of TERATE 2541 polyester polyol, 21 g of ALFAPOL FR408S (a Mannich based polyol), 35 g of a polyepoxyde according to the invention, 21 g of TCPP, 2.8 g of a silicone surfactant, 0.56 g of dimethylcyclohexylamine (DMCHA), 5.6 g of DABCO TMR®, 4.9 g of water and 39 g of a mixture HFC-365mfc/HFC-227ea (87/13). This polyol mixture was then brought in contact with 386 g of polymeric MDI (DESMODUR 44V20) to obtain a rigid polyisocyanurate foam.

Evaluation of the fire behavior of this foam according to DIN4102 test gave class B2 with a flame height of 6 cm.

Example 6 (comparison):

In this comparative example, the polyol mixture used comprises 127 g of STEPANPOL 2352 polyester polyol, 22 g of ARCOL 3758 polyether polyol, 30 g of TCPP, 2.25 g of silicone surfactant, 0.75 g of dimethylcyclohexylamine (DMCHA), 4.5 g of DABCO TMR, 1.0 g of water and 32 g of n-pentane. This mixture was then brought into contact with 379 g of polymeric MDI (DESMODUR 44N20) to obtain a foam composed of rigid polyisocyanurate. Evaluation of the fire behaviour of this foam according to the DIN 4102 test gave class B3 with a flame height of 16 cm.

Claims

1 - Process for the manufacture of foams composed of polyurethane or of modified polyurethane in which at least one polyol is reacted with at least one isocyanate in the presence of a catalyst, of a polyepoxide and of a blowing agent other than a chlorofluorocarbon, in particular a blowing agent comprising an HFC and/or a flammable blowing agent.

2 -Process according to Claim 1, in which the polyepoxide contains from 2 to 6 epoxy functions.

3 - Process according to Claim 1 or 2, in which the polyepoxide contains from 8 to 96 carbon atoms.

4 - Process according to any one of Claims 1 to 3, in which the polyepoxide is obtainable via a reaction of epichlorohydrin with an initiator compound containing at least two functional groups, each of the functional groups containing at least one active hydrogen atom.

5 - Process according to Claim 4, in which the polyepoxide is obtainable via the reaction of the initiator compound with from 1 to 5 equivalents of epichlorohydrin per functional group of the initiator compound.

6 - Process according to Claim 4 or 5, in which the initiator compound is an alcohol selected among ^-butyne-l^-diol and 2,3-dibromo-2-butene-l,4- diol.

7 - Process according to any of Claims 1 to 6, in which use is made of a flammable blowing agent.

8 - Process according to Claim 7, in which the blowing agent comprises a hydrocarbon.

9 - Process according to Claim 8 in which the blowing agent comprises a pentane, preferably n-pentane.

10 - Process according to Claim 7, in which the blowing agent comprises 1,1,1,3,3-pentafluorobutane. 11 - Process according to Claim 10, in which the blowing agent comprises a composition of 1,1,1,3,3-pentafluorobutane with at least one pentane or hexane. -

12 - Process according to Claim 7, in which the blowing agent is a composition of 1, 1, 1,3,3-pentafluoropropane with at least one pentane or hexane.

13 - Process according to any one of Claims 1 to 12, in which use is made of an isocyanate whose isocyanate index is at least 250, so as to obtain a polyisocyanurate foam.

14 - Process according to any of Claims 1 to 13, in which the structure of the polyol is essentially free from phosphorus.

.15 - Process according to any of Claims 1 to 14, in which use is made of a flame retardant comprising phosphorus in an amount such that the phosphorus content in the foam is from 0.1 to 1% by weight.

16 - Foam composed of polyurethane obtainable via the process according to any of Claims 1 to 15.

17 - Foam according to Claim 16, having a flame height below 15 cm when it is submitted to the test in the standard EN ISO 11925-2 (foam B2).

18 - Foam according to Claim 17, having a flame height below 13 cm when it is submitted to the test in the standard EN ISO 11925-2 (foam B2).

19 - Polyepoxide in accordance with Claim 5 or 6.

20 - Method of manufacture of a supported foam composed of polyurethane or a supported modified foam composed of polyurethane, according to which

(a) a layer of polyepoxide is deposited on at least one part of a solid support;

(b) a mixture which comprises reactants and which is appropriate for operating the process according to any of Claims 1 to 15 is deposited at least on the layer of polyepoxide; (c) the deposited mixture comprising reactants is reacted according to the process according to any of Claims 1 to 15.