Debondable articles by insertion of a sacrificial layer

Abstract

The present invention relates to a process for preparing a composite comprising a first substrate (P1), a layer (L1), a layer (L12) and a layer (L2), wherein the layer (L1) is at least partially connected with the substrate (P1) and at least partially connected with the layer (L12), and layer (L2) is at least partially connected with the layer (L12), the process comprising a step of providing the substrate (P1); applying a composition (C1) comprising a thermoplastic polymer (PP1) and a solvent composition (S1) comprising water to at least a part of a surface of substrate (P1); at least partially removing solvent composition (S1) to obtain layer (L1); and applying a composition (C2) suitable to form a polyurethane (PU1) to at least a part of the surface of layer (L1) to obtain the composite comprising the substrate (P1), the layer (L1), layer (L12) and the layer (L2); wherein layer (L1) is formed from the thermoplastic polymer (PP1), layer (L12) is formed from the thermoplastic polymer (PP1) and composition (C2) and the layer (L2) is formed from composition (C2). The present invention furthermore relates to the composite obtained or obtainable by said process as well as an article comprising the composite according to the present invention. The present invention also relates to a process for debonding an article comprising a composite according to the invention by using radiation or heat or radiation and heat.

Description

[0001] Debondable articles by insertion of a sacrificial layer

[0002] The present invention relates to a process for preparing a composite comprising a first substrate (P1 ), a layer (L1), a layer (L12) and a layer (L2), wherein the layer (L1) is at least partially connected with the substrate (P1) and at least partially connected with the layer (L12), and layer (L2) is at least partially connected with the layer (L12), the process comprising a step of providing the substrate (P1); applying a composition (C1) comprising a thermoplastic polymer (PP1) and a solvent composition (S1) comprising water to at least a part of a surface of substrate (P1); at least partially removing solvent composition (S1) to obtain layer (L1); and applying a composition (C2) suitable to form a polyurethane (PU1) to at least a part of the surface of layer (L1) to obtain the composite comprising the substrate (P1 ), the layer (L1), layer (L12) and the layer (L2); wherein layer (L1) is formed from the thermoplastic polymer (PP1 ), layer (L12) is formed from the thermoplastic polymer (PP1) and composition (C2) and the layer (L2) is formed from composition (C2). The present invention furthermore relates to the composite obtained or obtainable by said process as well as an article comprising the composite according to the present invention. The present invention also relates to a process for debonding an article comprising a composite according to the invention by using radiation or heat or radiation and heat.

[0003] Many consumer goods are made of multiple components of different materials which are bonded to one another by an adhesive. Such bonded articles are difficult to recycle and it is difficult to re-use the single materials because they have to be de-bonded before re-use. Consumer good manufactures increasingly demand concepts to increase sustainability by increasing recycle rates of used bonded articles. For example, high performance sport shoes are often based on thermoplastic or crosslinked polymers such as thermoplastic polyurethanes and polyurethane foams which are bonded to non-polyurethane materials such as polyester textiles or synthetic leather. The non-polyurethane materials have to be removed after the life cycle of the article by a debonding on demand mechanism before recycling and re-use of the polyurethane.

[0004] Similar needs exist in other technical areas to release bonded components of different materials to be able to separately recycle the different materials, for example car seats, dashboards , meat or cheese food packaging etc. WO 2019 / 175151 for example describes a method for making thermoplastic polyurethanes from recycled polyurethane materials. This method requires debonding non-polyurethane materials from the polyurethane materials.

[0005] WO 2018 / 156689 describes debondable adhesives and uses thereof for making and debonding articles of footwear. Debonding is achieved by use of carboxylic acids and salts thereof and by use of microwave irradiation.

[0006] WO2021 / 249749 describes a method of debonding thermoplastic foam materials by using a dispersion adhesive as sole binding agent.

[0007] There remains a need for improved methods that facilitate the recycling of different components of an article. The problem on which the invention is based is that of providing a composites and articles made of different components,such as for example shoes, which can be prepared in an easy manner and can be debonded under controlled conditions, with comparatively low energy consumption in short cycle-times. The bonded articles should, under normal storage, use and cleaning conditions, exhibit high resistance to premature debonding.

[0008] This object has been solved according to the present invention by a composite comprising a first substrate (P1 ), a layer (L1), a layer (L12) and a layer (L2), wherein the layer (L1) is at least partially connected with the substrate (P1 ) and at least partially connected with the layer (L12) and layer (L2) is at least partially connected with the layer (L12), wherein

[0009] (a) layer (L1) comprises a thermoplastic polymer (PP1 );

[0010] (b) layer (L2) comprises a polyurethane (PU1 );

[0011] (c) layer (L12) comprises the thermoplastic polymer (PP1 ) and the polyurethane (PU1 );

[0012] wherein layer (L1) and (L2) are chemically or physically connected with layer (L12).

[0013] The present invention further relates to a process for preparing a composite comprising a first substrate (P1 ), a layer (L1), a layer (L12) and a layer (L2), wherein the layer (L1) is at least partially connected with the substrate (P1 ) and at least partially connected with the layer (L12), and layer (L2) is at least partially connected with the layer (L12), the process comprising

[0014] (i) providing the substrate (P1);

[0015] (ii) applying a composition (C1 ) comprising a thermoplastic polymer (PP1 ) and a solvent composition (S1 ) comprising water to at least a part of a surface of substrate (P 1);

[0016] (iii) at least partially removing solvent composition (S1 ) to obtain layer (L1);

[0017] (iv) applying a composition (C2) suitable to form a polyurethane (PU1) to at least a part of the surface of layer (L1) to obtain the composite comprising the substrate (P1 ), the layer (L1), layer (L12) and the layer (L2);

[0018] wherein layer (L1) is formed from the thermoplastic polymer (PP1), layer (L12) is formed from the thermoplastic polymer (PP1) and composition (C2), and the layer (L2) is formed from composition (C2).

[0019] It was found that the combination of the layers (L1), (L12), and (L2) according to the present invention leads to high bond strength in the bonded articles under the conditions of the intended use such as dry conditions as well as in humid air or during washing, but can be debonded using controlled conditions such as elevated temperature or treatment with suitable solutions. It has been found that the specific combination of layers improves the bonding strength. This allows to prepare stable articles which nevertheless can be separated in to parts and to reuse or recycle the separate parts.

[0020] The composite according to the present invention comprises a first substrate (P1 ), a layer (L1), a layer (L12) and a layer (L2). Layer (L1) is at least partially connected with the substrate (P1 ) and at least partially connected with the layer (L12) and layer (L2) is at least partially connected with the layer (L12). Both layers (L1) and (L2) are chemicallyor physically connected with layer (L12). According to the present invention, it is also possible that one of the layers is physically connected with layer (L12) and the other layer is chemically connected with layer (L12).

[0021] According to the present invention, layer (L1) comprises a thermoplastic polymer (PP1 ), layer (L2) comprises a polyurethane (PU1) and layer (L12) comprises the thermoplastic polymer (PP1) and the polyurethane (PU1).

[0022] The present invention is also directed to a process for preparing said composite. The process according to the present invention comprises steps (i) to (iv) but may comprise further steps.

[0023] According to step (i), the substrate (P1) is provided. The shape and size of the substrate may vary. According to step (ii), a composition (C1) comprising a thermoplastic polymer (PP1) and a solvent composition (S1) comprising water is applied to at least a part of a surface of substrate (P 1). It has been found that the use of compositions (C1) and (C2) according to the invention allows to prepare the specific layer structure of the composites according to the present invention.

[0024] Composition (C1) comprises the thermoplastic polymer (PP1) and a solvent composition (S1 ). Suitable thermoplastic polymers (PP1) are in principle known to the person skilled in the art. Suitable thermoplastic polymers preferably are selected from group consisting of thermoplastic polyurethane polymers, polyester polymers, acrylic polymers, ethylene-vinyl acetate copolymers, styrene block copolymers, polyvinyl acetols, styrene acrylonitriles, polyolefins, polyacrylonitriles, polyvinylpyrrolidones, ethylene vinyl acetate terpolymers, functional ethylene vinyl acetates, ethylene acrylate copolymers, ethylene acrylate terpolymers, ethylene butadiene copolymers, and block copolymers. Suitable are also thermoplastic polymers with functional groups. According to a further embodiment, the present invention is also directed to a process as disclosed above, wherein the thermoplastic polymer (PP1 ) comprise a polymer with functional groups selected from carboxylic groups, hydroxyl groups, amino groups, phosphonate, C-C- double bond, sulfonate groups and epoxy groups.

[0025] Solvent composition (S1) comprises water and may comprise further solvents or additives such as fillers, thickeners, antifoam agents, etc.. Further solvents which may be present in the solvent composition (S1) may for example be acetone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, ethanol, i-propanol, methyl-ethyl-ketone, dimethylsulfoxide, or N,N-dimethyl lactamide. Preferably, the content of further solvents in the solvent composition is below 5000 ppm, preferably below 2500 ppm, in particular below 1000 ppm. Particular preference is given to water as sole solvent.

[0026] The composition (C1) preferably has a solids content of 10 to 70 % by weight. Typically, the content of the thermoplastic polymer (PP1) in the composition (C1) may vary in broad ranges. The content of the thermoplastic polymer (PP1) in composition (C1) preferably is in the range of from 30 to 70 % by weight.Composition (C1) preferably comprises the thermoplastic polymer (PP1 ) and the solvent composition in an amount of at least 90% by weight of the composition (C1 ), in particular in an amount of at least 95% by weight of the composition (C1 ), more preferable in an amount of at least 98% by weight of the composition (C1). According to a preferred embodiment, composition (C1) consists of the thermoplastic polymer (PP1) and the solvent composition (S1 ).

[0027] According to a further embodiment, the present invention is also directed to a process as disclosed above, wherein the composition (C1) comprises the solvent composition (S1) in an amount of 30 to 70 % by weight.

[0028] The application of composition (C1) preferably occurs by brushing, spraying, doctor blade coating, print or roll coating. The composition can be applied for example using an automated or machine assisted process, e.g. using an automatic sprayer. Typically, the composition (C1) is applied to the surface of the substrate (P1) in an amount sufficient to cover the respective surface.

[0029] The amount of composition (C1) applied to the surface of substrate (P1) is preferably in the range of from 10 g / m2to 400 g / m2(solid), more preferred from 20 to 200 g / m2, particularly preferred from 50 to 150 g / m2.

[0030] Suitable as composition (C1) are in principle also film forming polymer solutions such as for example an aqueous polyvinylpyrrolidone solution. The polyvinylpyrrolidone polymers preferably have Tg from 100°C to 180°C, preferably 105°C to 180°C.

[0031] The aqueous polyvinylpyrrolidone solution comprises at least one polyvinylpyrrolidone (homopolymer of vinylpyrrolidone or copolymer of vinylpyrrolidone with vinylacetate, vinylimidazol and vinylcaprolactame) dissolved in the aqueous phase. The content of polyvinylpyrrolidone is preferably adjusted such that the Brookfield viscosity of the total composition at 23°C is from 0.05 s to 40 Pas, particularly preferably from 1 s to 40 Pas , measured with DIN flow cup no. 4 according to DIN EN ISO 2431:2011.

[0032] The polyvinylpyrrolidone preferably has a K value of 25 to 100, particularly preferably 26 to 98, measured at 25°C as a 1% solution in water.

[0033] Preferably, the composition (C1) is selected from polymer dispersions. Suitable are in particular polymer dispersions from the product classes well known in the art, i.e. acrylic dispersions, sty rene-acry lie dispersions, vinylester dispersions, ethylene vinylester dispersions, styrene butadiene dispersions, which may for example be prepared by free radical emulsion polymerization. Suitable compositions are also the well-known polyurethane dispersions, prepared by polyaddition reaction of isocyanates and polyols and subsequent dispersion in water, as well as the polyurethanepolyacrylate hybrid dispersions and polyurethane-polystyrene-butadiene hybrid dispersions. Preferred compositions (C1) in form of water-based aqueous polymeric dispersions are aqueous polystyrene acrylic dispersions, aqueous acrylic dispersions, aqueous butadiene / styrene dispersions or aqueous polyurethane dispersions. More preferably,the composition (C1) is an aqueous acrylic dispersion or an aqueous polyurethane dispersion. Even more preferably, the composition (C1) is an aqueous polyurethane dispersion.

[0034] The thermoplastic polymer preferably is present in the composition (C1) in the form of particles. Composition (C1) preferably is a dispersion. According to a further embodiment, the present invention is also directed to a process as disclosed above, wherein the thermoplastic polymer (PP1) is present in the composition (C1) in the form of particles.

[0035] According to a further embodiment, the present invention is also directed to a process as disclosed above, wherein composition (C1) is a dispersion selected from the group consisting of aqueous polystyrene acrylic dispersions, aqueous acrylic dispersions, aqueous butadiene / styrene dispersions or aqueous polyurethane dispersions.

[0036] Suitable compositions (C1) are dispersions which have a viscosity of up to 1500mPas. Preferably, the viscosity of composition (C1) allows the application of the composition by spraying. Preferably, the composition has a viscosity of less than 500 mPas at 23°C, more preferable a viscosity of less than 300 mPas at 23 °C, in particular of less than 200 mPas at 23 °C, measured according to DIN EN ISO 3219-2:2021 at 23°C and a shear rate of 250 s1.

[0037] The composition (C1) preferably is selected form aqueous polyurethane dispersion adhesives. Suitable polyurethane adhesives preferably have a K value (measured as 1 wt.% solution in DMF at 25°C) of not more than 100, preferably from 40 to 90, more preferably from 45 to 90.

[0038] The K value is a relative viscosity number, which is determined in analogy to DIN EN ISO 1628-1 2021 at 25 °C. It comprises the flow rate of a 1 weight% strength solution of the polyurethane in DMF, relative to the flow rate of pure DMF, and characterizes the average molecular weight of the polyurethane.

[0039] According to a further embodiment, the present invention is also directed to a process as disclosed above, wherein composition (C1) is an aqueous polyurethane dispersion with a K-value in the range of from 40 to 90.

[0040] The thermoplastic polymer has a hardness that can be measured by a conventional Durometer method (conditions given in the experimental part). Preferably the hardness is from 50 shore A to 90 shore D, very preferably on the shore D scale between 20 shore D and 90 shore D.

[0041] Composition (C1) preferably is an aqueous dispersion of a thermoplastic polymer (PP1), in particular of a polyurethane. Preferably, the thermoplastic polymer (PP1) is characterized

[0042] by a K value of from 40 to 90, preferably from 45 to 90 measured as 1 wt.% solution in DMF at 25 °C;

[0043] by a glass transition temperature of less than 0°C, preferably than -10°C, measured by differential scanning calorimetry as the midpoint temperature of the second heating curve at a heating rate of 20 K / min,

[0044] and the dispersed polyurethane is constructed froma) at least one monomeric diisocyanate,

[0045] b) at least one diol, component (b) comprising at least one diol having a number-average molecular weight in the range from 500 to 5000 g / mol,

[0046] c) at least one monomer, different from the monomers (a) and (b), having at least one isocyanate group or at least one group reactive toward isocyanate groups, and additionally carrying at least one hydrophilic group or potentially hydrophilic group,

[0047] d) optionally at least one further compound, different from the monomers (a) to (c), having at least two reactive groups selected from alcoholic hydroxyl groups, primary or secondary amino groups or isocyanate groups, and

[0048] e) optionally at least one monofunctional compound, different from the monomers (a) to (d), having a reactive group which is an alcoholic hydroxyl group, a primary or secondary amino group or an isocyanate group.

[0049] Component b) is composed preferably of

[0050] b1) 10 to 100 mol%, based on the total amount of component b), of diols having a molecular weight from 500 to 5000 g / mol,

[0051] b2) 0 to 90 mol%, based on the total amount of component b), of diols having a molecular weight of 60 to less than 500 g / mol.

[0052] Particular mention may be made as monomers (a) of diisocyanates X(NCO)2, where X is a noncyclic aliphatic hydrocarbon radical having 4 to 15 carbon atoms, a cycloaliphatic or aromatic hydrocarbon radical having 6 to 15 carbon atoms, or an araliphatic hydrocarbon radical having 7 to 15 carbon atoms. Examples of such diisocyanates include tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1 ,4-diisocyanatocy-clohexane, 1-isocyanato-3,5,5-trimethyl-3-isocyanatomethyl-cyclohexane (IPDI), 2,2-bis(4-isocyanatocyclohexyl)-propane, trimethylhexane diisocyanate, 1,4-diisocyanatobenzene, 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene (TDI), 4,4'-diisocyanato-diphenylmethane, 2,4'-diisocyanatodiphenylmethane, p-xylylene diisocyanate, tetramethylxylylene diisocyanate (TMXDI), the isomers of bis(4-isocyanatocyclohexyl)methane (HMDI) such as the trans / trans, the cis / cis, and the cis / trans isomers, and mixtures of these compounds. Diisocyanates of this kind are available commercially. With particular preference the diisocyanate is selected from the group consisting of hexamethylene diisocyanate, 1-isocyanato-3,5,5-trimethyl-3-isocyanatomethylcyclohexane, 2,6-diisocyanatotoluene, and tetramethylxylylene diisocyanate, or a mixture thereof.

[0053] Particularly important mixtures of these isocyanates are the mixtures of the respective structural isomers of diisocya-natotoluene and diisocyanatodiphenylmethane; the mixture of 80 mol% 2,4-diisocyanatotoluene and 20 mol% 2,6-diisocyanatotoluene is particularly suitable. Also of particular advantage are the mixtures of aromatic isocyanates such as 2,4-diisocyanatotoluene and / or 2,6-diisocyanatotoluene with aliphatic or cycloaliphatic isocyanates such as hexamethylene diisocyanate or IPDI, in which case the preferred mixing ratio of the aliphatic to the aromatic isocyanates is 1:9 to 9:1, more particularly 4:1 to 1:4.The diols (b1) may be polyester polyols, which are known, for example, from Ullmanns Enzyklopadie der tech-nischen Chemie, 4th edition, volume 19, pp. 62 to 65. It is preferred to use polyester polyols which are obtained by reacting dihydric alcohols with dibasic carboxylic acids. Instead of the free polycarboxylic acids it is also possible to use the corresponding polycarboxylic anhydrides or corresponding polycarboxylic esters of lower alcohols or mixtures thereof to prepare the polyester polyols. The polycarboxylic acids can be aliphatic, cyclo aliphatic, araliphatic, aromatic or heterocyclic and can optionally be substituted, by halogen atoms for example, and / or unsaturated. Examples thereof include the following: suberic acid, azelaic acid, phthalic acid, isophthalic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrachlorophthalic anhydride, endomethylene tetrahydrophthalic anhydride, glutaric anhydride, maleic acid, maleic anhydride, fumaric acid, and dimeric fatty acids. Preferred dicarboxylic acids are those of the general formula HOOC-(CH2)y-COOH, where y is a number from 1 to 20, preferably an even number from 2 to 20, examples being succinic acid, adipic acid, sebacic acid, and dodecane dicarboxylic acid. Examples of suitable dihydric alcohols include ethylene glycol, propane-1,2- diol, propane-1, 3-diol, butane-1,3-diol, butene-1,4-diol, butyne-1,4-diol, pentane-1,5-diol, neopentyl glycol, bis(hydroxymethyl) cyclohexanes such as 1,4-bis(hydroxymethyl)cyclohexane, 2-methylpropane-1, 3-diol, methylpentanediols, and also diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, and dibutylene glycol and polybutylene glycols. Preferred alcohols are those of the general formula HO-(CH2)X-OH, where x is a number from 1 to 20, preferably an even number from 2 to 20. Examples of such alcohols are ethylene glycol, butane-1,4-diol, hexane-1 ,6-diol, octane-1, 8-diol, and dodecane-1 ,12-diol. Preference is also given to neopentyl glycol.

[0054] The diols (b1) may also be polycarbonate diols, such as may be obtained, for example, by reacting phosgene with an excess of the low molecular weight alcohols specified as synthesis components for the polyester polyols. The diols (b1) may also be lactone-based polyester diols, which are homopolymers or copolymers of lactones, preferably hy-droxyl-terminated adducts of lactones with suitable difunctional starter molecules. Preferred lactones contemplated are those derived from compounds of the general formula HO-(CH2)Z-COOH, where z is a number from 1 to 20 and where one H atom of a methylene unit may also be substituted by a C1 to C4 alkyl radical.

[0055] Examples are E-caprolactone, B-propiolactone, y-butyrolactone and / or methyl-y-caprolactone, and mixtures thereof. Examples of suitable starter components are the low molecular weight dihydric alcohols specified above as a synthesis component for the polyester polyols. The corresponding polymers of E-caprolactone are particularly preferred. Lower polyester diols or polyether diols as well can be used as starters for preparing the lactone polymers. Instead of the polymers of lactones it is also possible to use the corresponding chemically equivalent polycondensates of the hydroxycarboxylic acids corresponding to the lactones.

[0056] The diols (b1) may also be polyether diols. Polyether diols are obtainable in particular by polymerizing ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide or epichlorohydrin with itself, in the presence of BF3 for example, or by subjecting these compounds, optionally in a mixture or in succession, to addition reaction with starter components containing reactive hydrogen atoms, such as alcohols or amines, examples being water,ethylene glycol, propane-1, 2-diol, propane-1, 3-diol, 2,2-bis(4-hydroxyphenyl)propane, and aniline. Particular preference is given to polyether diols with a molecular weight of 500 to 5000, and in particular 600 to 4500. A particularly preferred polyether diol is polytetrahydrofuran. Suitable polytetrahydrofurans can be prepared by cationic polymerization of tetrahydrofuran in the presence of acidic catalysts, such as sulfuric acid or fluorosulfuric acid, for example. Preparation processes of this kind are known to the skilled person. Other suitable compounds b1) are a,co-diamino-polyethers, which are preparable by aminating polyalkylene oxides with ammonia.

[0057] Compounds subsumed under b1) include only those polyether diols composed to an extent of less than 20% by weight of ethylene oxide, based on their total weight. Polyether diols with at least 20% by weight of incorporated ethylene oxide units are hydrophilic polyether diols, which are counted as monomers c).

[0058] It is also possible to use polyhydroxyolefins, preferably those having 2 terminal hydroxyl groups, e.g., a, co-di hydroxypolybutadiene, a,w- dihydroxypolymethacrylic esters or a, co- dihydroxypolyacrylic esters, as monomers b1). Such compounds are known for example from EP-A 622378. Further suitable polyols are polyacetals, polysiloxanes, and alkyd resins.

[0059] The hardness and the elasticity modulus of the polyurethanes can be increased by using as diols (b) not only the diols (b1) but also low molecular weight diols (b2) having a molecular weight of from about 60 to 500, preferably from 62 to 200 g / mol. Monomers (b2) used are in particular the synthesis components of the short-chain alkane diols specified for preparing polyester polyols, preference being given to the unbranched diols having 2 to 12 C atoms and an even number of C atoms, and also to pentane-1 ,5-diol and neopentyl glycol. Examples of suitable diols b2) include ethylene glycol, propane-1, 2-diol, propane-1, 3-diol, butane-1, 3-diol, butene-1,4-diol, butyne-1,4-diol, pentane-1 ,5-diol, neopentyl glycol, bis-(hydroxymethyl)cyclohexanes such as 1,4-bis(hydroxymethyl)cyclohexane, 2-methylpropane-1, 3-diol, methyl pentane diols, additionally diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene glycol, dibutylene glycol, and polybutylene glycols. Preference is given to alcohols of the general formula HO-(CH2)X-OH, where x is a number from 1 to 20, preferably an even number from 2 to 20. Examples thereof are ethylene glycol, butane-1, 4-diol, hexane-1 ,6-diol, octane-1, 8-diol, and dodec-ane-1,12-diol. Preference is further given to neopentyl glycol.

[0060] In order to make the polyurethanes dispersible in water they comprise as synthesis components monomers (c), which carry at least one isocyanate group or at least one group reactive toward isocyanate groups and, furthermore, at least one hydrophilic group or a group which can be converted into a hydrophilic group. In the text below, the term "hydrophilic groups or potentially hydrophilic groups” is abbreviated to "(potentially) hydrophilic groups”. The (potentially) hydrophilic groups react with isocyanates at a substantially slower rate than do the functional groups of the monomers used to synthesize the polymer main chain. The fraction of the components having (potentially) hydrophilic groups among the total quantity of components (a) to (e) is generally such that the molar amount of the (potentially) hydrophilic groups, based on the amount by weight of all monomers (a) to (e), is from 30 to 1000, preferably 50to 500, and more preferably 80 to 300 mmol / kg. The (potentially) hydrophilic groups can be nonionic or, preferably, (potentially) ionic hydrophilic groups.

[0061] Particularly suitable nonionic hydrophilic groups are polyethylene glycol ethers composed of preferably 5 to 100, more preferably 10 to 80 repeating ethylene oxide units. The amount of polyethylene oxide units is generally 0 to 10%, preferably 0 to 6% by weight, based on the amount by weight of all monomers (a) to (e). Preferred monomers containing nonionic hydrophilic groups are polyethylene oxide diols containing at least 20% by weight of ethylene oxide, polyethylene oxide monools, and the reaction products of a polyethylene glycol and a diisocyanate which carry a terminally etherified polyethylene glycol radical. Diisocyanates of this kind and processes for preparing them are specified in patents US-A 3,905,929 and US-A 3,920,598. Ionic hydrophilic groups are, in particular, anionic groups such as the sulfonate, the carboxylate, and the phosphate groups in the form of their alkali metal salts or ammonium salts, and also cationic groups such as ammonium groups, especially protonated tertiary amino groups or quaternary ammonium groups. Potentially ionic hydrophilic groups are, in particular, those which can be converted into the abovementioned ionic hydrophilic groups by simple neutralization, hydrolysis or quaternization reactions, in other words, for example, carboxylic acid groups or tertiary amino groups. (Potentially) ionic monomers (c) are described at length in, for example, Ullmanns Enzyklopadie der technischen Chemie, 4th edition, volume 19, pp. 311 -313 and in, for example, DE-A 1 495745. Acid groups of the polyurethane are neutralized preferably to an extent of at least 10 mol%, more preferably at least 40 mol%, more preferably at least 70 mol%, very preferably at least 90 mol%, and more particularly completely (100 mol%) with a suitable neutralizing agent, and are therefore present in salt form, with the acid group being the anion and with the neutralizing agent being present as cation. Neutralizing agents are, for example, ammonia, alkali metal hydroxides such as NaOH or KOH, or alkanolamines.

[0062] Of particular practical importance as (potentially) cationic monomers (c) are, in particular, monomers containing tertiary amino groups, examples being tris(hydroxyalkyl)amines, N, N'-bis(hydroxyalkyl)alkylamines, N-hydroxyalkyldial-kylamines, tris(aminoalkyl)amines, N, N'-bis(aminoalkyl)alkylamines, and N-aminoalkyldialkylamines, the alkyl radicals and alkanediyl units of these tertiary amines consisting independently of one another of 1 to 6 carbon atoms.

[0063] Also suitable are polyethers containing tertiary nitrogen atoms and preferably two terminal hydroxyl groups, such as are obtainable in a conventional manner, for example, by alkoxylating amines containing two hydrogen atoms attached to amine nitrogen, such as methylamine, aniline or N, N'-dimethylhydrazine. Polyethers of this kind generally have a molar weight of between 500 and 6000 g / mol. These tertiary amines are converted into the ammonium salts either with acids, preferably strong mineral acids such as phosphoric acid, sulfuric acid, hydrohalic acids, or strong organic acids, or by reaction with suitable quaternizing agents such as C1 to C6 alkyl halides or benzyl halides, e.g., bromides or chlorides. Suitable monomers having (potentially) anionic groups normally include aliphatic cycloaliphatic, araliphatic or aromatic carboxylic acids and sulfonic acids which carry at least one alcoholic hydroxyl group or at least one primary or secondary amino group. Preference is given to dihydroxyalkylcarboxylic acids, especially those having 3 to 10 C atoms, such as are also described in US-A 3,412,054. Particular preference is given to compounds of the general formula (d)R3

[0064] i Q1 r~>2 / -M i

[0065] rlU rC r\ Url

[0066] COOH

[0067]

[0068] (d)

[0069] in which R1 and R2 are a C1 to C4 alkanediyl (unit) and R3 is a C1 to C4 alkyl (unit), and especially to dimethylolpropionic acid (DMPA). Also suitable are corresponding dihydroxysulfonic acids and dihydroxyphosphonic acids such as 2,3-dihydroxypropanephosphonic acid. Otherwise, suitable are dihydroxyl compounds having a molecular weight of more than 500 to 10000 g / mol and at least 2 carboxylate groups, which are known from DE-A 39 11 827. They are obtainable by reacting dihydroxyl compounds with tetracarboxylic dianhydrides such as pyromellitic dianhydride or cyclopentanetetracarboxylic dianhydride in a molar ratio of 2 : 1 to 1.05 : 1 in a polyaddition reaction. Particularly suitable dihydroxyl compounds are the monomers (b2) cited as chain extenders and also the diols (b1).

[0070] Suitable monomers (c) containing amino groups reactive toward isocyanates include aminocarboxylic acids such as lysine, p-alanine or the adducts of aliphatic diprimary diamines with a,p-unsaturated carboxylic or sulfonic acids that are specified in DE-A 2034479. Such compounds obey, for example, the formula (c2)

[0071] H2N-R4-NH-R5-X (C2)

[0072] where R4 and R5 independently of one another are a C1 to C6 alkanediyl unit, preferably ethylene and X is COOH or SO3H. Particularly preferred compounds of the formula (c2) are N-(2-aminoethyl)-2-aminoethanecarboxylic acid and also N-(2-aminoethyl)-2-aminoethanesufonic acid and the corresponding alkali metal salts, with Na being a particularly preferred counterion. Also particularly preferred are the adducts of the abovementioned aliphatic diprimary diamines with 2-acrylamido-2-methylpropanesulfonic acid, as described for example in DE-B 1 954090.

[0073] Where monomers with potentially ionic groups are used, their conversion into the ionic form may take place before, during or, preferably, after the isocyanate polyaddition, since the ionic monomers do not frequently dissolve well in the reaction mixture. Examples of neutralizing agents include ammonia, NaOH, triethanolamine (TEA), triisopropylamine (TIPA) or morpholine, or its derivatives. The sulfonate or carboxylate groups are more preferably in the form of their salts with an alkali metal ion or ammonium ion as counter ion.

[0074] The monomers (d), which are different from the monomers (a) to (c) and which may also be constituents of the polyurethane, may serve for crosslinking or chain extension. They may comprise nonphenolic alcohols with a functionality of more than 2, amines having 2 or more primary and / or secondary amino groups, and compounds which as well as one or more alcoholic hydroxyl groups carry one or more primary and / or secondary amino groups. Alcohols having a functionality of more than 2, which may be used in order to set a certain degree of branching or crosslinking, include for example trimethylolpropane, glycerol, or sugars.Compounds (d) are, for example, also isocyanates which as well as free isocyanate groups carry further, masked isocyanate groups, e.g., uretdione groups or carbodiimide groups. Also suitable are monoalcohols which as well as the hydroxyl group carry a further isocyanatereactive group, such as monoalcohols having one or more primary and / or secondary amino groups, monoethanolamine for example. Polyamines having 2 or more primary and / or secondary amino groups are used especially when the chain extension and / or crosslinking is to take place in the presence of water, since amines generally react more quickly than alcohols or water with isocyanates. This is frequently necessary when the desire is for aqueous dispersions of crosslinked polyurethanes or polyurethanes having a high molar weight. In such cases the approach taken is to prepare prepolymers with isocyanate groups, to disperse them rapidly in water, and then to subject them to chain extension or crosslinking by adding compounds having two or more isocyanate-reactive amino groups.

[0075] Amines suitable for this purpose are generally polyfunctional amines of the molar weight range from 32 to 500 g / mol, preferably from 60 to 300 g / mol, which comprise at least two amino groups selected from the group consisting of primary and secondary amino groups. Examples of such amines are diamines such as diaminoethane, diaminopropanes, diaminobutanes, diaminohexanes, piperazine, 2,5-dimethylpiperazine, amino-3-aminomethyl-3,5,5-trimethyl-cyclohexane (isophoronediamine, IPDA), 4,4'-diaminodicyclohexylmethane, 1,4-diaminocyclohexane, aminoethyl ethanolamine, hydrazine, hydrazine hydrate or triamines such as diethylenetriamine or 1,8-diamino-4-ami-nomethyloctane. The amines can also be used in blocked form, e.g., in the form of the corresponding ketimines (see for example CA-A 1 129 128), ketazines (cf., e.g., US-A 4,269,748) or amine salts (see US-A 4,292,226). Oxazoli-dines as well, as used for example in US-A 4,192,937, represent blocked polyamines which can be used for the preparation of the polyurethanes of the invention, for chain extension of the prepolymers. Where blocked polyamines of this kind are used they are generally mixed with the prepolymers in the absence of water and this mixture is then mixed with the dispersion water or with a portion of the dispersion water, so that the corresponding polyamines are liberated by hydrolysis. It is preferred to use mixtures of diamines and triamines, more preferably mixtures of isophoronediamine (IPDA) and diethylenetriamine (DETA).

[0076] The polyurethanes comprise preferably 1 to 30 mol%, more preferably 4 to 25 mol%, based on the total amount of components (b) and (d), of a polyamine having at least 2 isocyanate-reactive amino groups as monomers (d).

[0077] For the same purpose it is also possible to use, as monomers (d), isocyanates having a functionality of more than two. Examples of standard commercial compounds are the isocyanurate or the biuret of hexamethylene diisocyanate.

[0078] Monomers (e), which are used optionally, are monoisocyanates, monoalcohols, and monoprimary and -secondary amines. Their fraction is generally not more than 10 mol%, based on the total molar amount of the monomers. These monofunctional compounds customarily carry further functional groups such as olefinic groups or carbonyl groups and serve to introduce into the polyurethane functional groups which facilitate the dispersing and / or the crosslinkingor further polymer-analogous reaction of the polyurethane. Monomers suitable for this purpose include those such as ethanol, butylamine, dibutylamine, ethanolamine, diethanolamine ; isopropenyl-a,a’-dimethylbenzyl isocyanate (TMI) and esters of acrylic or methacrylic acid such as hydroxyethyl acrylate or hydroxyethyl methacrylate.

[0079] Within the field of polyurethane chemistry, it is general knowledge how the molecular weight (and thus the K value) of polyurethanes can be adjusted by selecting the proportions of the mutually reactive monomers and also the arithmetic mean of the number of reactive functional groups per molecule. Components (a) to (e) and their respective molar amounts are normally chosen so that the ratio A : B, where

[0080] A) is the molar amount of isocyanate groups and

[0081] B) is the sum of the molar amount of the hydroxyl groups

[0082] and the molar amount of the functional groups which are able to react with isocyanates in an addition reaction, is 0.5:1 to 2:1, preferably 0.8:1 to 1.5:1, more preferably 0.9:1 to 1.2:1. With very particular preference the ratio A:B is as close as possible to 1:1.

[0083] The monomers (a) to (e) employed carry on average usually 1.5 to 2.5, preferably 1.9 to 2.1, more preferably 2.0 isocyanate groups and / or functional groups which are able to react with isocyanates in an addition reaction.

[0084] The polyaddition of components (a) to (e) for preparing the polyurethane takes place preferably at reaction temperatures of up to 180°C, more preferably up to 150°C, for example from 20 to 180°C, preferably from 70 to 150°C, under atmospheric pressure or under autogenous pressure.

[0085] The preparation of polyurethanes, and of aqueous polyurethane dispersions, is known to the skilled person. The polyaddition of the synthesis components for the preparation of the polyurethanes, can be catalyzed using organic or organometallic compounds. Suitable catalysts include dibutyltin dilaurate (DBTL), tin(ll) octoate, tetrabutoxytitanium (TBOT), or diazabicyclo-[2.2.2]octane. Other suitable catalysts are salts of cesium, especially cesium carboxylates such as, for example, the formate, acetate, propionate, hexanoate, or 2-ethylhexanoate of cesium.

[0086] An aqueous polyurethane dispersion for the purposes of the present invention is a dispersion which has an aqueous solvent as a continuous phase. Suitable aqueous solvents are water and mixtures of water with water-miscible solvents, examples being alcohols, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tertbutanol, n-hexanol and cyclo hexanol; glycols, such as ethylene glycol, propylene glycol, and butylene glycol; the methyl or ethyl ethers of the dihydric alcohols, diethylene glycol, triethylene glycol, polyethylene glycols having number-average molecular weights of up to about 3000, glycerol and dioxane and also ketones, such as acetone in particular. Preferably the polyurethane dispersion is substantially free from organic solvents. By "substantially free from organic solvents" here is meant that the fraction of organic solvents is not more than 5% by weight, more preferably not more than 1% by weight, more particularly not more than 0.1% by weight, based on the total weight of the solvent.Preferably the polyurethanes are prepared in the presence of at least one organic solvent. Preferred organic solvents for preparing the polyurethanes are ketones, such as acetone and methyl ethyl ketone, and also N-methylpyr-rolidone. Acetone is used with particular preference. Where an at least partly water-miscible solvent is used for preparing the polyurethanes, the polyurethane dispersion of the invention may comprise, in addition to water, the organic solvent used for the preparation. It will be appreciated that the polyurethane dispersions of the invention can be prepared in the presence of at least one organic solvent which is subsequently replaced in whole or in part by water.

[0087] The polyurethane dispersions may be prepared for example by one of the following processes: According to the "acetone process", an ionic polyurethane is prepared from the synthesis components in a solvent which is miscible with water and which boils below 100°C under atmospheric pressure. Sufficient water is added to form a dispersion in which water represents the coherent phase. The "prepolymer mixing process" differs from the acetone process in that, rather than a fully reacted (potentially) ionic polyurethane, a prepolymer is first of all prepared that carries isocyanate groups. The components in this case are selected such that the as defined ratio A : B is greater than 1.0 and up to 3, preferably from 1.05 to 1.5. The prepolymer is first dispersed in water and then optionally crosslinked by reaction of the isocyanate groups with amines which carry more than 2 isocyanate-reactive amino groups, or chain extended by reaction of the isocyanate groups with amines which carry 2 isocyanate-reactive amino groups.

[0088] Chain extension also takes place when no amine is added. In that case, isocyanate groups are hydrolyzed to amino groups, which are consumed by reaction with remaining isocyanate groups in the prepolymers, with chain extension. Customarily, if a solvent has also been used during the preparation of the polyurethane, the major portion of the solvent is removed from the dispersion, by means of distillation under reduced pressure, for example, The dispersions preferably have a solvent content of less than 10 weight% and with particular preference are free from solvents. Solvents are understood to mean organic solvents.

[0089] According to step (iii) of the process according to the present invention, solvent composition (S1) is at least partially removed to obtain layer (L1). Layer (L1) comprises the thermoplastic polymer (PP1). Preferably, at least 80% by weight of the solvent composition are removed, more preferable at least 90% by weight, more preferably at least 95% by weight, in particular at least 98% by weight. Preferably, the amount of solvent composition (S1) in layer (L1) is less than 5000 ppm, preferably less than 2500 ppm, in particular less than 1000 ppm.

[0090] Suitable methods for removing the solvent composition (S1) are in principle known. It is for example possible to remove the solvent composition by treatment at elevated temperature, preferably a temperature above room temperature and preferably below 50°C, more preferable below 40°C. Preferably, the treatment at elevated temperature is carried out for a suitable time to at least partly remove the solvent composition (S1 ).

[0091] According to step (iv), composition (C2) suitable to form a polyurethane (PU1) is applied to at least a part of the surface of layer (L1) to obtain the composite comprising the substrate (P1 ), the layer (L1), layer (L12) and the layer (L2). According to step (iv), the layer (L12) and the layer (L2) are formed. Layer (L12) is formed from the thermoplasticpolymer (PP1 ) and composition (C2), and the layer (L2) is formed from composition (C2). The composition (C2) is suitable to form a polyurethane (PU1) and form a physical or chemical connection between layers (L1) and (L12), and (L12) and (L2) respectively. It has been found that the use of composition (C1) and the specific structure of the layer formed on the surface of substrate (P1) according to the invention allows for the formation of layers (L12) and (L2) in step (iv).

[0092] Preferably, step (iv) is carried out directly out after step (iii). However, it is also possible that the process comprises a storage step between steps (iii) and (iv).

[0093] Composition (C2) may be any composition suitable to form a polyurethane (PU1). The polyurethane (PU1) may be a compact polyurethane or a foamed polyurethane, such as a rigid polyurethane foam, a flexible polyurethane foam or a foamed thermoplastic polyurethane. Composition (C2) may be a reactive composition, i.e. a composition comprising suitable components to form the polyurethane or a composition comprising a preformed polyurethane and for example a suitable solvent.

[0094] Compositions suitable as composition (C2) are in principle known to the person skilled in the art. Suitable are for example compositions known for the preparation of coatings, adhesives, sealants, cast elastomers or polyurethane foams. Depending on the intended application the chemical structure of polyurethane (PU1) may vary. Composition (C2) may for example comprise isocyanates and isocyanate-reactive compounds. In case composition (C2) comprises components suitable to form a polyurethane, composition (C2) preferably is prepared by mixing the respective components immediately before step (iv).

[0095] Suitable isocyanates include diisocyanates or polyisocyanates which are in principle known to the person skilled in the art. In the context of the present invention, the polyisocyanates also include diisocyanates.

[0096] According to the invention, the polyisocyanate composition may also comprise two or more polyisocyanates. These may be unmodified or modified, wherein by a modification, the reaction of these isocyanates to isocyanate-termi-nated polyisocyanate prepolymer and I or the reaction to biuret, allophanat, uretdione, and I or isocyanurate-contain-ing isocyanates, preferably allophanate and I or isocyanurate containing isocyanates as well as their prepolymers is understood. These isocyanates can be used individually or in mixtures. Isocyanates used with preference are aliphatic, cycloaliphatic, araliphatic and / or aromatic isocyanates, more preferably tri-, tetra-, penta-, hexa-, hepta-and / or octamethylene diisocyanate, 2-methylpentamethylene 1 ,5-diisocyanate, 2-ethylbutylene 1 ,4-diisocyanate, pentamethylene 1 ,5-diisocyanate, butylene 1,4-diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclo-hexane (isophorone diisocyanate, IPDI), 1,4-bis(isocyanatomethyl)cyclohexane and / or 1,3-bis(isocyanatomethyl)cy-clohexane (HXDI), paraphenylene 2,4-diisocyanate (PPDI), tetramethylenexylene 2,4-diisocyanate (TMXDI), dicyclohexylmethane 4,4'-, 2,4'- and 2,2'-diisocyanate (H12 MDI), hexamethylene 1,6-diisocyanate (HDI), cyclohexane 1,4-diisocyanate, 1 -methylcyclohexane 2,4- and / or 2,6-diisocyanate, diphenylmethane 2,2'-, 2,4'- and / or 4,4'-diisocya-nate (MDI), naphthylene 1 ,5-diisocyanate (NDI), tolylene 2,4- and / or 2,6-diisocyanate (TDI), diphenylmethane diisocyanate, 3,3,‘-dimethyl-4,4‘-diisocyanato-diphenyl (TODI), dimethyldiphenyl 3,3'-diisocyanate, diphenylethane 1,2-diisocyanate and / or phenylene diisocyanate or prepolymers of these isocyanates and polyols or isocyanates and iso-cyanate-reactive components.

[0097] Particular preference is given to diphenylmethane 4,4'-diisocyanate (MDI), paraphenylene 2,4-diisocyanate (PPDI), naphthylene 1 ,5-diisocyanate (NDI), 3,3,‘-dimethyl-4,4‘-diisocyanato-diphenyl (TODI) , and linear aliphatic diisocyanates such as for example pentamethylene-1,5-diisocyanate, hexamethylene 1 ,6-diisocyanate.

[0098] Suitable isocyante reactive compounds are in particular polyols. Suitable polyols for the preparation of polyurethanes are in principle known to the person skilled in the art. It is possible to use any of the known compounds having at least two hydrogen atoms reactive toward isocyanates, for example those with functionality from 2 to 8 and with number-average molar mass from 62 to 15000 g / mol. Polyols preferably comprise polymeric compounds with at least two hydrogen atoms reactive towards isocyanate. Polymeric compounds with at least two hydrogen atoms reactive towards isocyanate usually have a functionality from 2 to 8 and number-average molar mass from 200 to

[0099] 15000 g / mol. By way of example, it is possible to use compounds selected from the group of the polyether polyols, fatty acid based polyols, polybutadiene based polyols, polyester polyols, and mixtures thereof as polymeric compounds with at least two hydrogen atoms reactive towards isocyanate.

[0100] Polyether polyols are by way of example produced from epoxides; for example, propylene oxide and / or ethylene oxide, or from tetrahydrofuran, with starter compounds exhibiting hydrogen-activity containing 1 to 8, preferably 2 to 6 and more preferably 2 to 4 reactive hydrogen atoms bound, or a starter molecule mixture which contains 1.5 to 8, preferably 1.8 to 6 and more preferably 1.9 to 3.5 reactive hydrogen atoms bound in the presence of catalysts. As starter molecules for example aliphatic alcohols, phenols, amines, carboxylic acids, water, or compounds based on natural substances, for example sucrose, sorbitol or mannitol can be applied. Preferred starter molecules are aliphatic alcohols having 2 to 6, preferably 2 to 4 alcohol groups, aliphatic amines and water. In a preferred embodiment polyetherols comprise molecules produced from starter molecules selected from the group, consisting of aliphatic alcohols having 2 to 6, preferably 2 to 4 alcohol groups, aliphatic amines and water, more preferred from the group consisting of aliphatic alcohols having 2 to 4 alcohol groups and water. In a preferred embodiment, polyetherols consist of molecules produced from starter molecules selected from the group, consisting of aliphatic alcohols having 2 to 6, preferably 2 to 4 alcohol groups, aliphatic amines and water. According to the present invention aliphatic alcohols are not only compounds where the alcohol group is bound to an aliphatic carbon atom but a compound free of aromatic structures. If mixtures of starter molecules with different functionalities are used, fractional functionalities can be obtained. Influences on the functionality, for example through side reactions, are not considered in the nominal functionality. Examples for suitable catalysts are basic catalysts and double-metal cyanide catalysts, as described by way of example in PCT / EP2005 / 010124, EP 90444, or WO 05 / 090440.Polyester polyols are by way of example produced from aliphatic or aromatic dicarboxylic acids and polyhydric alcohols, polythioether polyols, polyesteramides, hydroxylated polyacetals, and / or hydroxylated aliphatic polycarbonates, preferably in the presence of an esterification catalyst. Other possible polyols are mentioned by way of example in "Polyurethane Handbook, 2ndedition 1993, editor Guether Oertel, Carl HanserVerlag Munich, chapter 3.1.

[0101] Besides polyols with a molecular weight of more than 500 g / l, also chain extenders and / or crosslinking agents may be used.

[0102] Chain extenders used here can be compounds of molar mass less than 200 g / mol, preferably less than 150 g / mol and more preferred 62 to 150 g / mol, which have two groups reactive toward isocyanates as for example -SH or Nogroups and preferably OH-groups. According to the present invention, if chain extenders are used, they are preferably used in an amount of 0.1 to 20 wt.-%, more preferred 1 to 10 wt.-% and especially preferred 1 to 5 wt.-%, each based on the total weight of components. As chain extenders, use may be made of the chain extenders known in the production of polyurethanes. These are preferably low-molecular-weight compounds having two functional groups reactive toward isocyanates, for example monoethylene glycol, diethylene glycol, 1,2-propane diol, 1,3-propane diol, 1,4-butane diol, 1,3-butane diol, 1,5-pentane diol, 1,6-hexane diol, neopentyl glycol, tetraethylene glycol, dipropylene glycol, cyclohexane diol and aliphatic or aromatic amine based chain extenders as aliphatic or aromatic diamines like ethylene diamine, triethylene diamine and / or diethyl toluene diamine. Other possible low-molecular-weight chain extenders are mentioned by way of example in "Polyurethane Handbook”, Carl HanserVerlag, 2ndedition 1994, chapter 3.2 and 3.3.2.

[0103] In addition to chain extenders or instead of chain extenders, crosslinking agents may be added to the mixture. As crosslinking agents used in the invention are compounds of molar mass less than 200 g / mol preferably less than 150 g / mol which have at least three groups reactive toward isocyanates. Examples for crosslinking agents are glycerine, trimethylolpropane, pentaerythritol and triethanolamine, in a preferred embodiment glycerine is used as crosslinking agent. Other possible low-molecular-weight crosslinking agents are mentioned by way of example in "Polyurethane Handbook”, Carl Hanser Verlag, 2ndedition 1994, chapter 3.2 and 3.3.2.

[0104] The composition (C2) according to the present invention may also comprise catalysts for the reaction of the polyols with the polyisocyanates or additives such as for example adhesion promoters, auxiliaries and additions or additives, for example surface-active substances, dyes, pigments, oxidation stabilizers, UV stabilizers, water scavengers, latent heat storage means and hollow microbeads, defoamers, hydrolysis stabilizers. Suitable auxiliaries and additives can be found, for example, in the Kunststoffhandbuch, volume VII, edited by Vieweg and Hbchtlen, Carl Hanser Verlag, Munich 1966 (p. 103-113).

[0105] Typically, composition (C2) is applied in an amount to form layer (L2). Composition (C2) may be applied by known methods, such as for example spraying, brushing or also injection molding. A particularly suitable method is direct injection of the composition in a suitable mold.Depending on the intended use, the thickness of layer (L2) may vary in broad ranges. For example, for consumer goods and shoes, the thickness may be in the range of from 100 m to 500mm for electro mobility adhesives whereas for cushions, the thickness may be in the range of from 1 cm to 50 cm. For applications in the field of insulation, the thickness may be in the range of from 0.5 cm to 100 cm. For applications in the area of electro mobility, the thickness may be in the range of from 0.1 to 5 cm for adhesives and up to 50 cm for potting compact and foamed materials

[0106] It is also possible that further layers are applied to the composite. According to one embodiment of the present invention, a further substrate or layer may for example be applied to layer (L2) or be embedded in layer (L2).

[0107] Depending on the intended use of the composite, the shape and size of the substrate (P1) may vary. The substrate (P1) may for example comprise a material selected from the group consisting of a crepe rubber, a natural leather, a synthetic leather, a polyurethane, such as a polyurethane foam and / or a thermoplastic polyurethane, a thermoplastic rubber, a styrene butadiene rubber, a polyvinyl acetate, a polyamide (PA), a polyvinyl chloride, a polystyrene, an acrylonitrile butadiene styrene, a polyethylene terephthalate (PET), a polybutylene terephthalate, a textile, a metal, a fabric, a thermoplastic polyurethane knit fiber and a combination thereof. According to a further embodiment, the present invention is also directed to a process as disclosed above, wherein the substrate (P1) comprises a material selected from the group consisting of a crepe rubber, a natural leather, a synthetic leather, a polyurethane, such as a polyurethane foam and / or a thermoplastic polyurethane, a thermoplastic rubber, a styrene butadiene rubber, a polyvinyl acetate, a polyamide (PA), a polyvinyl chloride, a polystyrene, an acrylonitrile butadiene styrene, a polyethylene terephthalate (PET), a polybutylene terephthalate, a textile, a metal, a fabric, a thermoplastic polyurethane knit fiber and a combination thereof.

[0108] The composite according to the present invention may be an article or a part of an article. The composite may for example be a sporting good, an article of footwear, a consumer good or a part thereof.

[0109] The article of footwear is preferably selected from the group consisting of a shoe, a boot, and a sandal. Suitable shoes are for example an athletic shoe, a tennis shoe, a cross-trainer shoe, a soccer shoe, a children's shoe, a dress shoe, and a casual shoe.

[0110] According to a further embodiment, the present invention is also directed to a process as disclosed above, wherein the composite is an article or a part of an article selected from the group consisting of shoes, batteries, consumer articles, sports articles, articles for automotive applications, and cushioning elements, insulation elements, articles for electro mobility.

[0111] Preferably, the substrate (P1) is a part of an article of footwear. According to a further embodiment, the present invention is also directed to a process as disclosed above, wherein the substrate (P1) is a shoe part, more preferred ashoe part comprising a polyurethane, a thermoplastic polyurethane, a polyurethane foam, an expanded polyurethane, an expanded thermoplastic polyurethane, expanded thermoplastic polyurethane beads, a synthetic or natural textile or a mixture thereof.

[0112] According to a further aspect, the present invention is also directed to a composite obtained or obtainable by the process according to the invention. The present invention is also directed to an article comprising a composite according to the invention.

[0113] The article according to the present invention can be used for a variety of applications, such as shoes, in furniture, seating, automotive interior, automotive exterior, medical equipment, industrial applications, construction applications (such as insulation panels), appliance such as refrigerators, consumer goods such as consumer electronics, wearable devices, headphones, speakers, packaging, protection equipment, as cushioning, toys, animal toys, saddles, balls and sports equipment, for example sports mats, sport gloves, or as floor covering and wall paneling.

[0114] The article may also be footwear or part of footwear, preferably selected from the group consisting of a shoe, a boot, and a sandal. Suitable shoes are for example an athletic shoe, a tennis shoe, a cross-trainer shoe, a soccer shoe, a children's shoe, a dress shoe, and a casual shoe.

[0115] The substrate (P1) or any other part of the article can be any components commonly found in an article of footwear, and preferably comprise a component selected from the group consisting of an upper, an insole, an outsole, a midsole, a strobel, a vamp, a tip, a foxing, a tongue, an eyestay, and a combination thereof.

[0116] Preferably, the substrate is a shoe part made of a rubber, a natural leather, a synthetic leather, a polyurethane, a thermoplastic polyurethane, a styrene butadiene rubber, a vinyl acetate, a polyamide, a polyvinyl chloride, a polystyrene, an acrylonitrile butadiene styrene, a polyethylene terephthalate, a polybutylene terephthalate, a textile, a fabric, a thermoplastic polyurethane knit fiber, or a combination thereof, in particular polyurethane. Layer (L2) can for example be the shoe outsole or the upper.

[0117] Preferably, the bonded article is resistant to debonding at temperatures up to 70°C (without treatment with water, aqueous surfactant composition or any other washing composition) and resistant to debonding by treatment with aqueous surfactant compositions at temperatures up to 50 °C. Debonding tests with washing compositions are for example done by soaking pieces of bonded objects in aqueous solutions of surfactants at pH 6-10 and at the respective temperature (e.g. 50°C) for up to 60 min, while stirring or shaking.

[0118] According to a further embodiment, the present invention is also directed to the article as disclosed above, wherein the bonded article is

[0119] resistant to debonding at temperatures up to 50 °C with treatment with aqueous surfactant composition in a washing cycle andresistant to debonding by treatment with dry heat at temperatures up to 70 °C.

[0120] The article according to the present invention can be debonded using controlled conditions, for example using heat or radiation or a combination of both.

[0121] It has been found that the articles can be debonded using controlled conditions. The debonding can be conducted by treating the article at elevated temperature, for example in an oven or with a solution. The debonding can be conducted by treating the article at elevated temperature for a time period of 1 second to 60 minutes, preferentially 15 seconds to 30 minutes,

[0122] Typically, debonding could be carried out at a temperature in the range from 50°C to 160°C, preferably in a range of from 60°C to 140°C, more preferable in a range of from 70°C to 120°C. Typically debonding is carried out in air, in water environment at a pH above 9, preferably above 10, more preferable above 11, steam environment, or dry environment. According to the present invention, debonding may be carried out at a temperature in the range from 50°C to 160°C, in air, in water environment, steam environment, or dry environment.

[0123] If necessary, the bonded article is cut into smaller pieces before debonding. Debonding occurs after treatment of the article or of pieces thereof. A preferred method of debonding is a treatment with an aqueous surfactant composition characterized by soaking pieces of the bonded articles in aqueous solutions of surfactants at a pH of above 9, preferably above 10, on particular above 11, and temperatures from 60°C to 100°C for up to 60 min while stirring or shaking.

[0124] According to a further embodiment, the present invention is also directed to a process as disclosed above, wherein the article is separated into its parts by using heat. The heat can be supplied via heating in an oven, treatment with heated air, treatment with microwaves and radiofrequencies, treatment with heated water, heated aqueous solutions including further additives such as for example surfactants, or steam or can be generated using radiation such as for example microwave radiation according to the present invention. According to the present invention, also combinations of these methods can be used.

[0125] According to a further aspect, the present invention is also directed to a process for debonding an article comprising a composite obtained or obtainable by the process according to the present invention, wherein the article is separated into its parts by using radiation or heat or radiation and heat.

[0126] The parts of the article can easily be separated which allows to recycle the parts separately.

[0127] It has been found that the articles according to the present invention can be disassembled using suitable controlled conditions which makes them easier to recycle. According to the present invention, it is possible to disassemble the article and obtain the individual components allowing to separate these components and recycle them. This way,mixing of different components can be reduced or avoided. Furthermore, the individual components obtained may also be reused.

[0128] According to a further embodiment, the present invention is also directed to the article as disclosed above, wherein the article is recyclable. In case the components can be recovered in the recycling process, it is possible that the components can be reused as such.

[0129] Further embodiments of the present invention can be found in the claims and the examples. It will be appreciated that the features of the subject matter / processes / uses according to the invention that are mentioned above and elucidated below are usable not only in the combination specified in each case but also in other combinations without departing from the scope of the invention. For example, the combination of a preferred feature with a particularly preferred feature or of a feature not characterized further with a particularly preferred feature etc. is thus also encompassed implicitly even if this combination is not mentioned explicitly.

[0130] Illustrative embodiments of the present invention are listed below, but these do not restrict the present invention. In particular, the present invention also encompasses those embodiments which result from the dependency references and hence combinations specified hereinafter.

[0131] 1. A composite comprising a first substrate (P1 ), a layer (L1), a layer (L12) and a layer (L2), wherein the layer (L1) is at least partially connected with the substrate (P1 ) and at least partially connected with the layer (L12) and layer (L2) is at least partially connected with the layer (L12), wherein

[0132] (a) layer (L1) comprises a thermoplastic polymer (PP1);

[0133] (b) layer (L2) comprises a polyurethane (PU1);

[0134] (c) layer (L12) comprises the thermoplastic polymer (PP1) and the polyurethane (PU1);

[0135] wherein layer (L1) and (L2) are chemically or physically connected with layer (L12).

[0136] 2. A process for preparing a composite comprising a first substrate (P1 ), a layer (L1), a layer (L12) and a layer (L2), wherein the layer (L1) is at least partially connected with the substrate (P1 ) and at least partially connected with the layer (L12), and layer (L2) is at least partially connected with the layer (L12), the process comprising

[0137] (I) providing the substrate (P1);

[0138] (II) applying a composition (C1 ) comprising a thermoplastic polymer (PP1) and a solvent composition (S1 ) comprising water to at least a part of a surface of substrate (P1 );

[0139] (ill) at least partially removing solvent composition (S1 ) to obtain layer (L1);

[0140] (iv) applying a composition (C2) suitable to form a polyurethane (PU1) to at least a part of the surface of layer (L1) to obtain the composite comprising the substrate (P1 ), the layer (L1), layer (L12) and the layer (L2);wherein a layer (L1) is formed from the thermoplastic polymer (PP1 ), layer (L12) is formed from the thermoplastic polymer (PP1) and composition (C2), and the layer (L2) is formed from composition (C2).

[0141] 3. The process according to embodiment 2, wherein the thermoplastic polymer (PP1) is selected from the group consisting of sty rene-acry lie polymers, vinylesters, ethylene vinylester copolymers, styrene butadiene copolymers, polyvinylpyrrolidones and polyurethanes.

[0142] 4. The process according to embodiment 2, wherein the thermoplastic polymer (PP1) is present in the composition (C1) in the form of particles.

[0143] 5. The process according to any one of embodiments 2 to 4, wherein the composition (C1) comprises the solvent composition in an amount of 30 to 70 % by weight.

[0144] 6. The process according to any one of embodiments 4 or 5, wherein the thermoplastic polymer (PP1 ) comprises a polymer with functional groups selected from carboxylic groups, hydroxyl groups, amino groups, phosphonate, C-C- double bond, sulfonate groups and epoxy groups.

[0145] 7. The process according to any one of embodiments 2 to 6, wherein composition (C1) is a dispersion selected from the group consisting of aqueous polystyrene acrylic dispersions, aqueous acrylic dispersions, aqueous butadiene / styrene dispersions or aqueous polyurethane dispersions.

[0146] 8. The process according to any one of embodiments 2 to 7, wherein composition (C1) is an aqueous polyurethane dispersion with a K-value in the range of from 40 to 90.

[0147] 9. The process according to any one of embodiments 2 to 8, wherein the substrate (P1) comprises a material selected from the group consisting of a crepe rubber, a natural leather, a synthetic leather, a polyurethane, such as a polyurethane foam and / or a thermoplastic polyurethane, a thermoplastic rubber, a styrene butadiene rubber, a polyvinyl acetate, a polyamide (PA), a polyvinyl chloride, a polystyrene, an acrylonitrile butadiene styrene, a polyethylene terephthalate (PET), a polybutylene terephthalate, a textile, a metal, a fabric, a thermoplastic polyurethane knit fiber and a combination thereof.

[0148] 10. The process according to any one of embodiments 2 to 9, wherein the composite is an article or a part of an article selected from the group consisting of shoes, batteries, consumer articles, sports articles, articles for automotive applications, insulating parts and cushioning elements.

[0149] 11. The process according to any one of embodiments 2 to 10, wherein the substrate (P1) is a shoe part, more preferred a shoe part comprising a synthetic or natural textile, polyurethane, a thermoplastic polyurethane, apolyurethane foam, an expanded polyurethane, an expanded thermoplastic polyurethane, expanded thermoplastic polyurethane beads or a mixture thereof.

[0150] A composite comprising a first substrate (P1 ), a layer (L1), a layer (L12) and a layer (L2), wherein the layer (L1) is at least partially connected with the substrate (P1) and at least partially connected with the layer (L12) and layer (L2) is at least partially connected with the layer (L12), wherein

[0151] (a) layer (L1) comprises a thermoplastic polymer (PP1) wherein the thermoplastic polymer (PP1) is present in the composition (C1) in the form of particles;

[0152] (b) layer (L2) comprises a polyurethane (PU1);

[0153] (c) layer (L12) comprises the thermoplastic polymer (PP1) and the polyurethane (PU1);

[0154] wherein layer (L1) and (L2) are chemically or physically connected with layer (L12).

[0155] A process for preparing a composite comprising a first substrate (P1 ), a layer (L1), a layer (L12) and a layer (L2), wherein the layer (L1) is at least partially connected with the substrate (P1) and at least partially connected with the layer (L12), and layer (L2) is at least partially connected with the layer (L12), the process comprising

[0156] (I) providing the substrate (P1);

[0157] (II) applying a composition (C1) comprising a thermoplastic polymer (PP1) and a solvent composition (S1) comprising water to at least a part of a surface of substrate (P1) wherein the thermoplastic polymer (PP1) is present in the composition (C1) in the form of particles;

[0158] (iii) at least partially removing solvent composition (S1) to obtain layer (L1);

[0159] (iv) applying a composition (C2) suitable to form a polyurethane (PU1) to at least a part of the surface of layer (L1) to obtain the composite comprising the substrate (P1 ), the layer (L1), layer (L12) and the layer (L2);

[0160] wherein a layer (L1) is formed from the thermoplastic polymer (PP1), layer (L12) is formed from the thermoplastic polymer (PP1) and composition (C2), and the layer (L2) is formed from composition (C2).

[0161] The process according to embodiment 13, wherein the composition (C1) comprises the solvent composition in an amount of 30 to 70 % by weight.

[0162] The process according to any one of embodiments 13 or 14, wherein the thermoplastic polymer (PP1 ) comprises a polymer with functional groups selected from carboxylic groups, hydroxyl groups, amino groups, phosphonate, C-C- double bond, sulfonate groups and epoxy groups.16. The process according to any one of embodiments 13 to 15, wherein composition (C1) is a dispersion selected from the group consisting of aqueous polystyrene acrylic dispersions, aqueous acrylic dispersions, aqueous butadiene / styrene dispersions or aqueous polyurethane dispersions.

[0163] 17. The process according to any one of embodiments 13 to 16, wherein composition (C1) is an aqueous polyurethane dispersion with a K-value in the range of from 40 to 90.

[0164] 18. The process according to any one of embodiments 13 to 17, wherein the substrate (P1) comprises a material selected from the group consisting of a crepe rubber, a natural leather, a synthetic leather, a polyurethane, such as a polyurethane foam and / or a thermoplastic polyurethane, a thermoplastic rubber, a styrene butadiene rubber, a polyvinyl acetate, a polyamide (PA), a polyvinyl chloride, a polystyrene, an acrylonitrile butadiene styrene, a polyethylene terephthalate (PET), a polybutylene terephthalate, a textile, a metal, a fabric, a thermoplastic polyurethane knit fiber and a combination thereof.

[0165] 19. The process according to any one of embodiments 13 to 18, wherein the composite is an article or a part of an article selected from the group consisting of shoes, batteries, consumer articles, sports articles, articles for automotive applications, insulating parts and cushioning elements.

[0166] 20. The process according to any one of embodiments 13 to 19, wherein the substrate (P1) is a shoe part, more preferred a shoe part comprising a a synthetic or natural textile, polyurethane, a thermoplastic polyurethane, a polyurethane foam, an expanded polyurethane, an expanded thermoplastic polyurethane, expanded thermoplastic polyurethane beads or a mixture thereof.

[0167] 21. A composite obtained or obtainable by the process according to any one of embodiments 2 to 11.

[0168] 22. A composite obtained or obtainable by the process according to any one of embodiments 13 to 20.

[0169] 23. An article comprising a composite according to any one of embodiments 1, 12, 21 or 22.

[0170] 24. The article according to embodiment 23, wherein the bonded article is

[0171] resistant to debonding at temperatures up to 50 °C with treatment with aqueous surfactant composition in a washing cycle and

[0172] resistant to debonding by treatment with dry heat at temperatures up to 70 °C.

[0173] 25. A process for debonding an article comprising a composite according to embodiment 1 or 12 or a composite obtained or obtainable by the process according to any one of embodiments 2 to 11 or 13 to 20, wherein the article is separated into its parts by using radiation or heat or radiation and heat.The following examples illustrate the invention.

[0174] Examples

[0175] 1. Methods

[0176] Viscosity of polymer dispersions is measured according to DIN EN ISO 3219-2:2021 (at 23°C and a shear rate of 250 s1).

[0177] The dispersions (10 g) are dried in a mold (5.5 cm diameter) at 40°C for 3 days and then at 23°C for 7 days. Thermal properties are measured by differential scanning calorimetry.

[0178] Glass-transition temperature (Tg) (as the midpoint temperature of the second heating curve at a heating rate of 20 K / min), melting-points (Tm) are determined according to DIN ISO 11357 (2018) (melting point = peak temperature) by heating with 20 K / min after cooling to -80°C; from a film at its untreated state (drying see above).

[0179] The K-value was determined according to DIN EN ISO 1628-1:2021.

[0180] Film preparation for shore-hardness:

[0181] A siliconized mould (14,514,5cm) is filled with 150 g of the dispersion. The material is dried on a heating plate at 40°C for 3 days. Then further dried to constant weight at 85°C in an oven, then at 23°C for another 7 days.

[0182] Shore hardness is measured according to DIN ISO 48-4:2018; (3 films are stacked to give 6mm thickness); temperature: 23 °C 150 % relative humidity

[0183] Measuring time: 3 seconds

[0184] 2. Used polymer dispersion

[0185] 2.1 Example 1 : amorphous PUD

[0186] 310 g of a polyesterdiol made of adipic acid, 1.6 hexanediol and neopentyl glycol (OH number = 56 mg KOH / g), is reacted with 73 g 1.4-butanediol and 151 g toluylenediisocyanate (80 / 20 mixture of isomers) in 131 g dry acetone starting at 45°C and heating up to 65- 68 °C, keeping there for 30 min. Then 0.08 g tetrabutyl titanate as catalyst is added and the reaction continued for 60 min. Then 27.6 g hexamethylenediisocyanate (HDI) is added and the reaction is continued until the NCO-value is 0.9%. The mixture is diluted with 586 g acetone and cooled to 50°C.The chain extension is done with 32 g of a 40% (weight percentage) aqueous solution of aminoethyl-aminopropi- onic acid sodium salt, fed in 1 min and reacted for 10 min while heating to 55°C. Then 844 g of deionized water is fed over 45 min. The acetone is removed by vacuum distillation, using 0.1 g of defoamer Foamstar PB 2724 (modified polyalkylene glycol, BASF). Solids content is 42.6%

[0187] >

[0188] Example 1

[0189] ___>

[0190] K-value

[0191] > >

[0192] Viscosity : 81 mPas

[0193] >

[0194] Tg1 -19°C

[0195] Hardness i 29 Shore D, 3 seconds

[0196] >

[0197]

[0198] 2.2 Example 2: PUD according to example 1 in WO2012 / 13506 -

[0199] The example 1 in W0201213506 was repeated: solid content is 40%.

[0200] >

[0201] Example 2

[0202] K-value 55 > >

[0203] Viscosity 48 mPas

[0204] >

[0205] Tg -51°C .

[0206] > >

[0207] Tm 47°C >

[0208]

[0209] >

[0210] 2.3 Example 3: PUD with Carbodiimid

[0211] 676 g of a polyesterdiol from adipic acid and 1,4 butanediol (OH number 45) are reacted with 0.11 g titaniumtetrabutylate, 40 g IPDI , 0,77 g NCO-terminated polycarbodiimid Elastostab H02 , BASF) at 60°C in 153 g dry acetone for 60 min. Then 37.8 g HDI is added and the temperature raised to 74°C. The reaction is continued until the NCO-value is lower than 1,25%. The mixture is diluted with 539 g acetone and cooled to 35-40°C. Then 22.4 g of aminoethyl aminoethansulfonate sodium salt (50% in water) diluted with 22 g dem. water is added in 3 min, followed by 4.6 g Isophoronediamine diluted in 23 g dem. water also in 3 min. Before disperga- tion 38.7 g of a 20% aqueous solution of Lutensol AT18 (Ethoxylated (18EO) C16-C18 fatty alcohol) BASF) is added as, followed by dispergation with 463 g demineralized water in 15 min, Immediately after the water feed, 4 g of N-( 2- aminoethyl)-ethanolamine in 30 g water is added in 15 min , with additional amount of 200 g dem. water. The acetone is removed by vacuum distillation with the help of two drops of defoamer (FoamStar PB 2724: modified polyalkylene glycol, BASF) and the solids content adjusted to 50% .Example 3

[0212] K-value 60

[0213] Viscosity 169 mPas

[0214] Tg -55°C

[0215] Tm 51 °C

[0216] Hardness 42 Shore D, 3 seconds

[0217]

[0218] 2.4 Example 4: crystalline PUD

[0219] 663,9g of a polyesterdiol from adipic acid and 1 ,4-butanediol (OH number 46) is reacted with 27.12 g IPDI and 40.4 g HDI at 100°C in 60 g dry acetone until a NCO-value between 1.00% - 0.97% is reached. The mixture is diluted with 804 g acetone and cooled to 40°C. The chains are stopped by adding a mixture of 3.55 g diethanolamine, 0.83g N-(2- aminoethyl)-ethanolamine and 16 g dem. water. Then, 14.1 g of aminoethyl-ami- noethane-sulfonate sodium salt (50% in water) diluted with 17g dem. water is added in 3 min. After 10 min the dispersion is continued in 30 min. with 718 g deionized water. The acetone is removed by vacuum distillation with the help of two drops of defoamer (FoamStar PB 2724, BASF). To stabilize the dispersion, 74 g of a 20%solution of Lutensol AT 18 (BASF) is added and the solids content adjusted to 50 % .

[0220] Example 4

[0221] K-value 55

[0222] Viscosity 62 mPas

[0223] Tg I -55°C

[0224] >

[0225] Tm . 1 47°C .

[0226]

[0227] 2.5 Example 5: 2 Tg Dispersions

[0228] 1039 g of a polyesterdiol from adipic acid and Isophthalic acid (molar 1 : 1 ) and 1.6 hexanediol (molecular weight 2000 g / mol), 104.6 g of dimethylolpropionic acid (DMPA), 186.8 g Butanediol-1,4 were reacted with 900 g IPDI) in 530 g dry acetone in a pressurized reactor; starting at 50°C, increasing the temperature in 30 min to 90°C, then at 90°C for 8 h at 2.9 bar. The mixture was diluted with 1852 g acetone and cooled to 40°C and expanded to atmospheric pressure. The NCO-value was determined to 1.2%. Then 10.2 g of Isophoronediamine were added in a shot, followed by 81 g diethylethanolamine (neutralization agent) in 5 min. After 5 min stirring, the dispersion step was continued with 3567 g deionized water in 37 min at 30°C, followed by an addition of 19.8 diethylenetriamine in 340 g deionized water in 30min. The acetone was removed by vacuum distillation with the help of 0.23 g of defoamer (FoamStar PB 2724, BASF) and the solids content was 37.4%.Example 5

[0229] K-value : 63

[0230] Viscosity 31 mPas

[0231] Tg1 -20°C

[0232] Tg2 69°C

[0233] Hardness : 62 Shore D, 3 seconds

[0234]

[0235] 3 Application of dispersion on substrate and subsequent foaming

[0236] The dispersions were applied by using a pressurized spraying gun from the company SATA (air pressure: 4 bar), equipped with a 1.3 mm nozzle on polyurethane artificial leather fabric to form layer (L1). The amount of dried dispersion on the fabric was measured by weighting the dried coated fabric and is reported in table 1.

[0237] Shoe foam system 1 was infused using a machine from Maingroup Technologies Sri. (Model: Pragma 1 ST) directly on the laminated substrate (direct soling). In this step, layers (L12) and layers (L2) are formed. Layer layer (L12) which is at least partially connected to layer (L1) and at least partially connected to layer (L2) is formed from the thermoplastic polymer and the shoe foam system, and the layer (L2) which is at least partially connected with the layer (L12) is formed from the shoe foam system.

[0238] For shoe foam system 1, the following A and B component were used at a mixing weight ratio: 100 / 115 (polyol to diisocyanate).

[0239] A component:

[0240] Starting material Amount [W%]

[0241] Mono ethylene glycol 9.36

[0242] Tap Water 0. 64

[0243] Polyesterpolyol based on adipic acid, gylcerin, 80.85

[0244] monoethylene glycole and diethylene

[0245] glycole, with functionality :2.3 and Mw: 2300g / mol

[0246] tertiary amine-based catalyst 0.6

[0247] surfactant 0.4

[0248] high-molecular-weight plasticizer 2.5

[0249]

[0250] B Component:

[0251] Polyester based prepolymer, based on 4,4 MDI / 2,4 MDI (available from BASF SE as Lupranat MRS), 4,4 MDI / Carbodiimide of MDI (available from BASF SE as Lupranat MM103), polyester based on adipic acid, monoethylene glycole and 1,4 butandioleand polyester based on adipic acid, monoethylene glycole, diethylgly- coleand glycerine, propylene carbonate and stabilized with diglycol-bischlorformiate, NCO content: 18.2%.

[0252] The NCO content in weight-% was determined via back titration of the corresponding sample with an excess of di-n-butylamine 1M in chlorobenzene with 1 molar hydrochloric acid.

[0253] 4 Bonding between Artificial PU fabric and shoe foam 1

[0254] The adhesion between the artificial leather PU fabric and foam was measured according to ISO 20344:2011,5.2 at 23°C. The adhesion level is reported in table 1. Material breakage (foam surface) was observed.

[0255] Sample number substrate Dispersion Amount in g / m2 Adhesion level in From example Nr: N / mm

[0256] Sample 1 PU artificial leather 3 103 5.4

[0257] Sample 2 PU artificial leather 1 115 4.8

[0258] Sample 3 PU artificial leather 5 100 5.1

[0259] Sample 4 PU artificial leather / / 3.7

[0260]

[0261] Table 1: Adhesion leve on inventive (system 1 o 3) and reference system (sample 4, no dispersion applied)

[0262] 5 Debonding test

[0263] To the bonded specimens as described above, a Shear Adhesion Failure Temperature (SAFT) test was effectuated. The bonded substrates were securely fixed in an oven, with a known weight of 120 g attached to them. The oven temperature was set to 60C and increased every 20 minutes of 10C. The temperature at which the substrates separated from each other was recorded. The resulting values are reported in table 2.

[0264] Sample number substrate Dispersion from example no: SAFT Test / T in °C Sample 1 PU artificial leather 3 105

[0265] Sample 2 PU artificial leather 1 135

[0266] Sample 3 PU artificial leather 5 150

[0267] Sample 4 PU artificial leather / No debonding > 200°C

[0268]

[0269] Table 2: SAFT values6 Washing test

[0270] The bonded materials were washed in a hot water solution containing 3mL / L Persil as detergent.

[0271] The temperature was raised up to from 60°C to 100°C under continuous stirring (400rpm). The temperature was maintained 10 minutes before increasing it to further 10°C. No debonding under the simulated washing conditions was observed.

[0272] Literature cited

[0273] WO 2019 / 175151

[0274] WO 2018 / 156689

[0275] WO2021 / 249749

[0276] Ullmanns Enzyklopadie der technischen Chemie, 4th edition, volume 19, pp. 62 to 65 and pp. 311 -313

[0277] EP-A622378

[0278] US-A 3,905,929

[0279] US-A 3,920,598

[0280] DE-A 1 495745

[0281] US-A 3,412,054

[0282] DE-A 2034479

[0283] CA-A 1 129 128

[0284] US-A 4,269,748

[0285] US-A 4,292,226

[0286] US-A 4, 192,937

[0287] PCT / EP2005 / 010124

[0288] EP 90444

[0289] W005 / 090440

[0290] Polyurethane Handbook, 2ndedition 1993, editor Guether Oertel, Carl HanserVerlag Munich, Chapter chapter 3.1, 3.2 and 3.3.2

[0291] Kunststoffhandbuch, volume VII, edited by Vieweg and Hbchtlen, Carl HanserVerlag, Munich 1966 (p. 103-113)

Claims

Claims1. A composite comprising a first substrate (P1), a layer (L1), a layer (L12) and a layer (L2), wherein the layer (L1) is at least partially connected with the substrate (P1) and at least partially connected with the layer (L12) and layer (L2) is at least partially connected with the layer (L12), wherein(a) layer (L1) comprises a thermoplastic polymer (PP1);(b) layer (L2) comprises a polyurethane (PU1);(c) layer (L12) comprises the thermoplastic polymer (PP1) and the polyurethane (PU1);wherein layer (L1) and (L2) are chemically or physically connected with layer (L12).

2. A process for preparing a composite comprising a first substrate (P1 ), a layer (L1), a layer (L12) and a layer (L2), wherein the layer (L1) is at least partially connected with the substrate (P1) and at least partially connected with the layer (L12), and layer (L2) is at least partially connected with the layer (L12), the process comprising(i) providing the substrate (P1);(ii) applying a composition (C1) comprising a thermoplastic polymer (PP1 ) and a solvent composition (S1) comprising water to at least a part of a surface of substrate (P1);(iii) at least partially removing solvent composition (S1) to obtain layer (L1);(iv) applying a composition (C2) suitable to form a polyurethane (PU1) to at least a part of the surface of layer (L1) to obtain the composite comprising the substrate (P1 ), the layer (L1), layer (L12) and the layer (L2);wherein a layer (L1) is formed from the thermoplastic polymer (PP1), layer (L12) is formed from the thermoplastic polymer (PP1) and composition (C2), and the layer (L2) is formed from composition (C2).

3. The process according to claim 2, wherein the thermoplastic polymer (PP1) is selected from the group consisting of styrene-acrylic polymers, vinylesters, ethylene vinylester copolymers, styrene butadiene copolymers, polyvinylpyrrolidones and polyurethanes.

4. The process according to claim 2, wherein the thermoplastic polymer (PP1 ) is present in the composition (C1) in the form of particles.

5. The process according to any one of claims 2 to 4, wherein the composition (C1) comprises the solvent composition in an amount of 30 to 70 % by weight.

6. The process according to any one of claims 4 or 5, wherein the thermoplastic polymer (PP1 ) comprises a polymer with functional groups selected from carboxylic groups, hydroxyl groups, amino groups, phosphonate, C- C- double bond, sulfonate groups and epoxy groups.

7. The process according to any one of claims 2 to 6, wherein composition (C1) is a dispersion selected from the group consisting of aqueous polystyrene acrylic dispersions, aqueous acrylic dispersions, aqueous butadi- ene / styrene dispersions or aqueous polyurethane dispersions.

8. The process according to any one of claims 2 to 7, wherein composition (C1) is an aqueous polyurethane dispersion with a K-value in the range of from 40 to 90.

9. The process according to any one of claims 2 to 8, wherein the substrate (P1) comprises a material selected from the group consisting of a crepe rubber, a natural leather, a synthetic leather, a polyurethane, such as a polyurethane foam and / or a thermoplastic polyurethane, a thermoplastic rubber, a styrene butadiene rubber, a polyvinyl acetate, a polyamide (PA), a polyvinyl chloride, a polystyrene, an acrylonitrile butadiene styrene, a polyethylene terephthalate (PET), a polybutylene terephthalate, a textile, a metal, a fabric, a thermoplastic polyurethane knit fiber and a combination thereof.

10. The process according to any one of claims 2 to 9, wherein the composite is an article or a part of an article selected from the group consisting of shoes, batteries, consumer articles, sports articles, articles for automotive applications, insulating parts and cushioning elements.

11. The process according to any one of claims 2 to 10, wherein the substrate (P1) is a shoe part, more preferred a shoe part comprising a synthetic or natural textile, polyurethane, a thermoplastic polyurethane, a polyurethane foam, an expanded polyurethane, an expanded thermoplastic polyurethane, expanded thermoplastic polyurethane beads or a mixture thereof.

12. A composite obtained or obtainable by the process according to any one of claims 2 to 11.

13. An article comprising a composite according to any one of claims 1 or 12.

14. The article according to claim 13, wherein the bonded article isresistant to debonding at temperatures up to 50 °C with treatment with aqueous surfactant composition in a washing cycle andresistant to debonding by treatment with dry heat at temperatures up to 70 °C.

15. A process for debonding an article comprising a composite according to claim 1 or a composite obtained or obtainable by the process according to any one of claims 2 to 11 , wherein the article is separated into its parts by using radiation or heat or radiation and heat.

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