Use of waterborne adhesive composition for bonding using coagulation

Abstract

The present invention is directed to the use of a waterborne adhesive composition for the adhesive bonding of one or more substrates after at least partial coagulation of the waterborne adhesive composition and while the at least partially coagulated waterborne adhesive composition is still in a wet state, wherein the waterborne adhesive composition comprises a waterborne dispersion comprising dispersed polymer particles comprising both (i) a polyurethane and (ii) a vinyl polymer, said dispersed particles comprising the polyurethane and the vinyl polymer in a weight ratio of the polyurethane to the vinyl polymer in the range from 25:75 to 90:10, and the polyurethane-vinyl polymer comprises a crystalline phase having a melting temperature in the range from 30 to 80 °C and an enthalpy of fusion of at least 10 J / g, whereby the melting temperature and the enthalpy of fusion are determined by differential scanning calorimetry according to DIN EN ISO 11357-1:2017 (2017-02) at a heating rate of 20 K / min, and wherein the adhesive bonding is effected at a temperature below the melting temperature of the polyurethane-vinyl polymer.

Description

[0001] USE OF WATERBORNE ADHESIVE COMPOSITION FOR BONDING USING COAGULATION

[0002] The present invention relates to the use of waterborne adhesive compositions for bonding substrate(s), especially foam substrate(s), using coagulation.

[0003] Wien adhesively bonding foam substrates to other substrates, for example for the combinations foam-foam, foam-wood and foam-plastic, use is predominantly made of polychloroprene dispersion adhesives in the two-component (20) spray coagulation process. In this process, the adhesive and a coagulant are conveyed separately into a spray gun, mixed in the spray jet and instantaneously coagulated on the substrate. As the mixing does not take place until in the spray jet, no pot life needs to be taken into account. In addition, the coagulated adhesive remains on the substrate surface to be adhesively bonded and only diffuses to a minor extent, if at all, into the pore structure of the foam substrates. High initial strengths and sufficiently long open times are frequently achieved.

[0004] Important fields of application are the production of mattresses and seating furniture. In particular from Scandinavian countries, there is a demand for environmentally benign alternatives to the polychloroprene dispersion adhesives, also for example to prevent discoloration of the adhesive joints or to facilitate recycling of foam by different recycling methods.

[0005] Adhesives based on aqueous polyurethane dispersions have become established worldwide in demanding industrial applications, for example in the case of shoe manufacturing, the bonding of parts for motor vehicle interiors, sheet lamination or the adhesive bonding of textile substrates.

[0006] In the case of the use of such dispersions for bonding substrates, this is usually carried out after the heat-activation process. In this case, the dispersion is applied to the substrate and, after complete evaporation of the water or during evaporation of the water, the adhesive layer is activated by heating, for example using infrared radiation, and is converted into an adhesive state. The temperature at which the adhesive film becomes sticky is referred to as the activation temperature. EP1167454A1 describes aqueous dispersion adhesives containing multiphase particles of polyurethane and a copolymer and / or terpolymer produced by emulsion polymerisation of vinyl- and / or acrylic and / or methacrylic monomeric material(s) in a weight ratio between 50:50 and 10:90 (polyurethane to emulsion polymer) for lamination a PVC foil to Medium Density Fibre (MDF) board after heat activation. Two- component (2K) adhesive systems are applied consisting of a first component comprising the aqueous dispersion and a second component comprising a polyisocyanate crosslinker. The heat activation process is of limited suitability for the adhesive bonding of foam substrates. The slow evaporation of the water, in particular, requires long waiting times between application of the adhesive and the bonding process, or appropriate drying installations. In addition, a not insignificant portion of the adhesive can diffuse into the pores of the foam substrates prior to or during the drying and is then no longer available for the actual bonding.

[0007] The adhesives based on aqueous polyurethane dispersions which are established on the market are generally not suitable for the use of the spray coagulation process since they either do not coagulate sufficiently rapidly or do not have sufficient initial strengths. The open time, that is to say the time period between application of the adhesive until joining together the parts to be joined, during which a sufficiently strongly bonded connection is still obtained, is generally a couple of seconds. For many bonding processes, however, a longer open time is required.

[0008] WO 2013 / 053786 A1 describes aqueous polyurethane dispersions, the polymer of which has a melting temperature in the range from 30°C to 50°C, determined by differential scanning calorimetry in accordance with DIN 65467 at a heating rate of 20 K / min, wherein the polymer is obtainable from two dissimilarly crystallizing polyester polyols in specified quantitative ratios. These polyurethane dispersions are primarily suitable as cold contact adhesives, but can also be employed using spray coagulation processes. However, the initial strengths achievable thereby are insufficient for most foam bonding applications.

[0009] W02020064829A1 teaches dispersion adhesives based on a mixture of semicrystalline polyurethane dispersions with plasticizers and tackifier resins and their use in bonding foam in a 2C spray coagulation process. WO2021043674A1 teaches dispersion adhesives based on a mixture of semicrystalline polyurethane dispersions with plasticizers and optionally tackifier resins and their use in bonding foam in a 2C spray coagulation process The plasticizer applied in W02020064829A1 and WO2021043674A1 are low molecular compounds bearing polar groups such as di(phenoxyethyl)formal and non-volatile esters based on aromatic carboxylic acids such as benzoic acid. The adhesives possess a sufficient open time and bondline softness and bonding of foam can be done immediately after the application of the adhesive to both substrates. However the blending step necessary to make the adhesive is time consuming, since the plasticizers tend to only slowly mix with the aqueous polyurethane dispersion. Also plasticizers are generally seen as unwanted substances in adhesives used in many consumer articles and especially furniture due to their intrinsic tendency to migrate out of the adhesive layer (since it are low molecular weight compounds) where they can lead to staining and potential contact to the skin of humans or animals.

[0010] CN 107779143 describes a two-component (2C) spray glue comprising a component A and a component B, wherein the component A is a waterborne polyurethane-vinyl polymer dispersion and the component B is a curing agent. It has been found that the polyurethane- vinyl polymers described have an insufficient crystallinity and that the adhesives do not coagulate sufficiently rapidly and do not have sufficient initial strengths. In the description of this patent application, it is described to use very highly concentrated solutions of coagulants of at least 5% by weight, which may lead to corrosion on sensitive materials. Also the adhesive compositions are not suitable for the 1C-spray coagulation process.

[0011] The object of the present invention was therefore that of providing waterborne polyurethane adhesive compositions that are suitable for bonding one or more substrates in a still wet state after at least partial coagulation of the waterborne adhesive composition, which does not exhibit the disadvantages of the prior art and which features high initial strengths and a sufficiently long open time.

[0012] Surprisingly, it has now been found that waterborne adhesive compositions comprising multiphase particles comprising polyurethane and vinyl polymer in a weight ratio in the range of from 25:75 to 90:10, are outstandingly suitable for the adhesive bonding of substrates after at least partial coagulation of the waterborne adhesive composition and while the at least partially coagulated waterborne adhesive composition is still in a wet state, while the amount of plasticizer can be reduced or even the plasticizer can be omitted.

[0013] The present invention is directed to the use of a waterborne adhesive composition for the adhesive bonding of one or more substrates after at least partial coagulation of the waterborne adhesive composition and while the at least partially coagulated waterborne adhesive composition is still in a wet state, wherein the waterborne adhesive composition comprises a waterborne dispersion comprising dispersed polymer particles comprising both (i) a polyurethane and (ii) a vinyl polymer, said dispersed particles comprising the polyurethane and the vinyl polymer in a weight ratio of the polyurethane to the vinyl polymer in the range of from 25:75 to 90:10, and the polyurethane-vinyl polymer comprises a crystalline phase having a melting temperature in the range from 30 to 80 °C and an enthalpy of fusion of at least 10 J / g, whereby the melting temperature and the enthalpy of fusion are determined by differential scanning calorimetry according to DIN EN ISO 11357-1:2017 (2017-02), at a heating rate of 20 K / min, and wherein the adhesive bonding is effected at a temperature below the melting temperature of the polyurethane-vinyl polymer.

[0014] It has surprisingly been found that the waterborne dispersions as defined in the present invention are outstandingly suitable for use in cold contact adhesives, i.e. for bonding substrates without having to apply heat-activation, and in particular in a process where the bonding is done with the adhesive being still in a wet state as in a spray coagulation process.

[0015] In the context of the present invention, a polyurethane is a polymer obtained by polymerization of one or more polyols and one or more polyisocyanates, but it also includes those in which also monoamines and / or diamines are used as formation components, possibly as chain extenders. The polyurethanes that can be used in the present invention include polyurethanes as well as polyurethane-ureas. Preferably the polyurethane present in the waterborne adhesive composition used in the present invention is a polyurethane-urea. Methods for preparing polyurethanes are known in the art and are described in for example the Polyurethane Handbook 2nd Edition, a Carl Hanser publication, 1994, by G. Oertel. In the present invention, the adhesively bonding of substrate(s) is effected after at least partial coagulation of the waterborne adhesive composition and while the at least partially coagulated waterborne adhesive composition is still in a wet state. In the present invention, the coagulation can be induced without having to apply heat and the bonding can be effected without having to apply heat. In the process of the present invention for the adhesive bonding of one or more substrates, the bonding is effected at a temperature below the melting temperature of the polyurethane, preferably the bonding is effected at ambient temperature. Coagulation is the process of agglomeration of particles into larger particles, for coagulation substantial amount of water still needs to be present. In the adhesive bonding process according to the present invention substantial amount of water are still present in the adhesive; at the time of bonding, the adhesive applied to the surface to be bonded usually still comprises from 5 to 60 wt.% of water, preferably from 10 to 50 wt.% of water, more preferably from 15 to 50 wt.% of water, relative to the total weight of the adhesive. In the present invention, coagulation of the waterborne adhesive composition takes place at a temperature below the melting temperature of the polyurethane-vinyl polymer, preferably at ambient temperature.

[0016] Inducing coagulation of the waterborne adhesive composition used in the present invention takes place either by contacting of the waterborne adhesive composition with a coagulant (for example calcium chloride) preferably in combination with applying shear forces, such as for example by spraying and mixing both the coagulant and the adhesive composition, or takes place by shearing (which for example takes place when applying the waterborne adhesive composition, to at least a part of the surface of at least one of the to be joined substrates, is effected by spraying, rolling or brushing), if needed in the presence of a compound in the waterborne adhesive composition that reduces the coagulation stability of the dispersion (“destabilizer”, for example sodium chloride). For example, the so called 1C spray coagulation process can be used. In this process, the adhesive formulation is applied by a spray gun and coagulation is effected by shear force in the spray nozzle and fast evaporation of water from the aerosols takes place before they reach the substrate. In a preferred embodiment of the invention, applying the waterborne adhesive composition, to at least a part of the surface of at least one of the to be joined substrates, is effected by rolling. In another preferred embodiment, applying the waterborne adhesive composition, to at least a part of the surface of at least one of the to be joined substrates, is effected by spraying. In this preferred embodiment, coagulation of the waterborne adhesive composition preferably takes place in a two-component (2C) spray coagulation process.

[0017] A polymer is referred to as semicrystalline or crystalline when it exhibits a melting peak in DSC measurement in accordance with DIN EN ISO 11357-1:2017 (2017-02) with a heating rate of 20 K / min. The melting peak is caused by the melting of regular substructures in the polymer. The melting temperature and enthalpy of fusion are determined during the first heating up starting from a starting temperature of -100°C in the DSC measurement according to DIN EN ISO 11357-1 :2017 (2017-02) with a heating rate of 20 K / min. When applying the DIN EN ISO 11357-1:2017 (2017-02) to determine the melting temperature and the enthalpy ef fusion, the standard part DIN EN ISO 11357-3:2018-07 is used. The melting temperature of the polyurethane-vinyl polymers present in the waterborne adhesive composition used in the invention is preferably in the range from 35 °C to 80 °C, more preferably in the range from 40 °C to 70 °C, particularly preferably in the range from 40 °C to 55 °C, very particularly preferably in the range from 42 °C to 55 °C. The enthalpy of fusion of the polyurethane-vinyl polymers present in the waterborne adhesive composition used in the present invention or of the polymer layers obtained from the formulations according to the invention is at least 10 J / g, preferably at least 15 J / g, more preferably at least 17 J / g, more preferably at least 18 J / g, particularly preferably at least 19 J / g. The polyurethane-vinyl polymer preferably has an enthalpy of fusion of at most 100 J / g, more preferably of at most 90 J / g, even more preferably of at most 80 J / g, even more preferably of at most 70 J / g. The first heating is evaluated in order to also detect polymers which crystallize slowly.

[0018] For all upper and / or lower boundaries of any range given herein, the boundary value is included in the range given, unless specifically indicated otherwise. Thus, when saying from x to y, means including x and y and also all intermediate values.

[0019] The waterborne adhesive composition used in the present invention is in the form of an aqueous polymer dispersion comprising dispersed polymer particles comprising at least one polyurethane, usually polyurethane-urea, and at least one vinyl polymer. The polyurethane and the vinyl polymer are present in the dispersed particles in a weight ratio of the polyurethane to the vinyl polymer of at least 25:75, preferably of at least 30:70, more preferably of at least 35:65, even more preferably of at least 40:60, most preferably higher than 50:50. The polyurethane and the vinyl polymer are present in the dispersed particles in a weight ratio of the polyurethane to the vinyl polymer of at most 90:10, preferably of at most 85:15, more preferably of at most 80:20.

[0020] The dispersed particles comprising the polyurethane and the vinyl polymer are advantageously obtained by free radical polymerization of at least one vinyl monomer in the presence of at least one water-dispersed polyurethane thereby obtaining a hybrid of polyurethane and vinyl polymer (polyurethane-vinyl polymer)). Accordingly, the vinyl polymer is advantageously formed in-situ by polymerizing the one or more vinyl monomers in the presence of a preformed aqueous polyurethane dispersion.

[0021] By a polyurethane-vinyl polymer hybrid (also referred herein as polyurethane-vinyl polymer) is meant that a vinyl polymer is prepared by the free-radical polymerization of vinyl monomer(s) in the presence of the polyurethane by forming an aqueous dispersion of said polyurethane resin and polymerising one or more vinyl monomers to form a vinyl polymer such that said vinyl polymer becomes incorporated in-situ into said aqueous dispersion by virtue of polymerising vinyl monomer(s) used to form the vinyl polymer in the presence of the polyurethane resin. Vinyl monomer is added before, during and / or after preparation of the polyurethane and the vinyl monomer is polymerized by adding a free radical yielding initiator to polymerize the vinyl monomer in the presence of the polyurethane. Suitable free radical yielding initiators are well known in the art and include mixtures partitioning between the aqueous and organic phases. Suitable free-radical-yielding initiators include inorganic peroxides such as ammonium persulphate, hydrogen peroxide, organic peroxides, such as benzoyl peroxide, alkyl hydroperoxides such as t-butyl hydroperoxide and cumene hydroperoxide; dialkyl peroxides such as di-t-butyl peroxide; peroxy esters such as t-butyl perbenzoate and the like; mixtures may also be used. The peroxy compounds are in some cases advantageously used in combination with suitable reducing agents (redox systems) such as iso-ascorbic acid. Azo compounds such as azobisisobutyronitrile may also be used. Metal compounds such as Fe.EDTA (EDTA is ethylene diamine tetracetic acid) may also be usefully employed as part of the redox initiator system. The amount of initiator or initiator system to use is conventional, e.g. within the range of 0.05 to 6 wt.% based on the weight of vinyl monomer used.

[0022] The at least one vinyl polymer of the hybrid preferably has a calculated glass transition temperature Tgof at least -60 °C, more preferably of at least -50 °C, even more preferably of at least -40 °C. The at least one vinyl polymer of the hybrid preferably has a calculated glass transition temperature Tgof at most 50 °C, more preferably of at most 45 °C, even more preferably of at most 40 °C, even more preferably of at most 35 °C, even more preferably of at most 30 °C, even more preferably of at most 25 °C, even more preferably of at most 20 °C, even more preferably of at most 15 °C, even more preferably of at most 10 °C, even more preferably of at most 5 °C, most preferably of at most 0 °C. As used herein, the glass transition temperature is determined by calculation by means of the Fox equation. Thus, the Tg in Kelvin, of a copolymer having "n" copolymerised comonomers is given by the weight fractions W of each comonomer type and the Tg’s of the homopolymers (in Kelvin) derived from each comonomer (as listed, for example, in J. Brandrup, E.H. Immergut, Polymer handbook 4th edition p. VI 193) according to the equation: 1 / Tg= S(Wn / Tgn).

[0023] The calculated Tg in Kelvin may be readily converted to °C.

[0024] Preferably at least 80 wt.%, more preferably at least 95 wt.% and most preferably 100 wt.% of the total weight of vinyl monomers used are of a,p-mono-unsaturated vinyl monomers. Examples of vinyl monomers include but are not limited to 1,3- butadiene; isoprene; styrene; a-methyl styrene; (meth)acrylic amides; vinyl ethers; vinyl esters such as vinyl acetate, vinyl propionate, vinyl laurate; vinyl esters of versatic acid such as VeoVa 9 and VeoVa 10 (VeoVa is a trademark of Resolution); heterocyclic vinyl compounds; alkyl esters of mono- olefinically unsaturated dicarboxylic acids such as di-n- butyl maleate and di-n-butyl fumarate; dialkylitaconates such as dimethyltaconate, diethylitaconate, dibutylitaconate and in particular, esters of acrylic acid or of methacrylic acid of formula CH2=CR4-COOR5wherein R4is H or methyl and R5is optionally substituted alkyl of from 1 to 20 carbon atoms (more preferably from 1 to 8 carbon atoms) or cycloalkyl of from 3 to 20 carbon atoms (more preferably from 3 to 6 carbon atoms). Examples of such esters of acrylic acid or of methacrylic acid which are methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate (all isomers), octyl (meth)acrylate (all isomers), 2-ethylhexyl (meth)acrylate, isopropyl (meth)acrylate and n-propyl (meth)acrylate. Preferred monomers of formula CH2=CR4- COOR5include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate (all isomers), octyl (meth)acrylate (all isomers), ethyl hexyl acrylate (all isomers) and isobornyl (meth)acrylate.

[0025] Preferably, at least 30 wt.%, more preferably at least 40 wt.%, more preferably at least 50 wt.%, even more preferably at least 60 wt.%, even more preferably at least 70 wt.% and even more preferably at least 80 wt.% of the total amount of vinyl monomer(s) used to prepare the vinyl polymer is selected from the group consisting of methyl methacrylate, butyl acrylate, butyl methacrylate, ethyl hexyl acrylate, octyl acrylate (preferably 2-octyl acrylate), styrene and any mixture of two or more of said monomers. Preferably, the vinyl monomer(s) used to prepare the vinyl polymer is selected from the group consisting of styrene, methyl methacrylate, ethyl acrylate, butyl acrylate, butyl methacrylate, 2-ethyl hexyl acrylate, 2-octyl acrylate and any mixture of two or more of said monomers. More preferably at least 30 wt.%, preferably at least 50 wt.% and more preferably at least 70 wt.% of the total amount of the vinyl monomer(s) used to prepare the vinyl polymer is styrene, methyl methacrylate, n-butyl acrylate, 2-ethyl hexyl acrylate, 2-octyl acrylate or any mixture of two or more of said monomers. Preferably less than 0.1 wt.% of the total amount of the vinyl monomer(s) used to prepare the vinyl polymer is acrylonitirile, more preferably the vinyl monomer(s) used to prepare the vinyl polymer does not comprise acrylonitrile. Acrylonitrile is under scrutiny due to the hazards that exist from handling the monomer during manufacturing and from residual monomers in the dispersion adhesive. The polyurethane is preferably obtained by the reaction of at least the following components (A1)-(A3) and optionally (A4):

[0026] (A1) At least one polyisocyanate,

[0027] (A2) At least one isocyanate-reactive compound that contains at least one salt group which is capable to render the polyurethane dispersible in water and / or at least one functional group that can be converted into a salt group which is capable to render the polyurethane dispersible in water ,

[0028] (A3) At least one isocyanate-reactive polyol other than (A2), and

[0029] (A4) Optionally at least one amino-functional isocyanate reactive compound other than (A2).

[0030] Component (A1)

[0031] At least one polyisocyanate is used as component (A1). The amount of component (A1) is preferably in the range from 5 to 20 wt.%, more preferably in the range from 6.5 to 16 wt.%, more preferably in the range from 8 to 13 wt.%, relative to the total amounts of components used to prepare the polyurethane from which the building blocks from the polyurethane are emanated. If the polyurethane is obtained by the reaction of (A1), (A2) and (A3) and optionally (A4)), the total amounts of components used to prepare the polyurethane from which the building blocks from the polyurethane are emanated is the sum of the weight amounts of components (A1), (A2) and (A3) and, if applied, (A4). Component (A1) comprises any suitable organic polyisocyanate including aliphatic, cycloaliphatic, araliphatic and / or aromatic polyisocyanates. Examples of suitable polyisocyanates include ethylene diisocyanate, 1,5-pentane diisocyanate, 1,6-hexamethylene diisocyanate (HDI), 2,2,4- trimethyl-1,6-hexamethylene diisocyanate, isophorone diisocyanate (IPDI), cyclohexane- 1 ,4-diisocyanate, dicyclohexylmethane diisocyanate such as 4,4’-dicyclohexylmethane diisocyanate (4,4’-Hi2 MDI), p-xylylene diisocyanate, p-tetramethylxylene diisocyanate (p- TMXDI) (and its meta isomer m-TMXDI), 1,4-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4’-diphenylmethane diisocyanate (4,4’-MDI), polymethylene polyphenyl polyisocyanates, 2,4’-diphenylmethane diisocyanate, 3(4)- isocyanatomethyl-1 -methyl cyclohexyl isocyanate (IMCI) and 1,5-naphthylene diisocyanate.

[0032] Further examples are derivatives based on the afore mentioned diisocyanates having a uretdione, isocyanurate, carbodiimide, allophanate, biuret, iminooxadiazine dione and / or oxadiazine trione structure with two or more isocyanate groups. Mixtures of the polyisocyanates can be used as well. Preferably, the amount of polyisocyanates with more than two isocyanate groups is below 35 wt.%, more preferably below 20 wt.% and especially below 10 wt.% of the component (A1). Component (A1) preferably comprises hexamethylene diisocyanate (CAS number 822-06-0) and / or toluene diisocyanate (CAS number 26471-62-5). Component (A1) preferably consists of 1 ,5-pentane diisocyanate (CAS number 4538-42-5), hexamethylene diisocyanate (CAS number 822-06-0), isophorone diisocyanate (CAS number 4098-71-9), dicyclohexylmethane- 4,4’-diisocyanate H12MDI (CAS number 5124-30-1), 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4’-diphenylmethane diisocyanate (4,4’-MDI), or 2,4’-diphenylmethane diisocyanate or of any mixture of any two or more thereof. More preferably, the at least one polyisocyanate according to (A1) comprises (i) 1,5-pentane diisocyanate and / or hexamethylene diisocyanate and (ii) isophorone diisocyanate and / or dicyclohexylmethane- 4,4’-diisocyanate H12MDI.

[0033] The polyurethane preferably comprises reacted hexamethylene diisocyanate and / or reacted 1 ,5-pentane diisocyanate in an amount of in the range from 3 to 19 wt.%, more preferably in the range from 4 to 15 wt.%, more preferably in the range from 4.5 to 12 wt.%, most preferably in the range from 5 to 10 wt.%, whereby the amount of reacted hexamethylene diisocyanate and / or reacted 1,5-pentane diisocyanate is the amount of hexamethylene diisocyanate and 1,5-pentane diisocyanate used to prepare the polyurethane relative to the total amounts of components used to prepare the polyurethane from which the building blocks from the polyurethane are emanated. The polyurethane preferably comprises (I) reacted hexamethylene diisocyanate and / or reacted 1,5-pentane diisocyanate and (II) reacted isophorone diisocyanate and / or reacted dicyclohexylmethane-4,4’- diisocyanate H12MDI in such an amount that the weight ratio of the summed amount of reacted hexamethylene diisocyanate and reacted 1,5-pentane diisocyanate to the summed amount of reacted isophorone diisocyanate and reacted dicyclohexylmethane-4,4’- diisocyanate H12MDI in the polyurethane is in the range from 0.25 to 20, more preferably in the range from 1 to 15, more preferably in the range from 1 to 10, most preferably in the range from 1.2 to 8 or in the range from 1.2 to 5 or in the range from 1.2 to 3 or in the range from 1.2 to 2, whereby the amount of reacted compound x is the amount of compound x used to prepare the polyurethane relative to the total amounts of components used to prepare the polyurethane from which the building blocks from the polyurethane are emanated.

[0034] Component (A2)

[0035] At least one isocyanate-reactive compound that contains at least one salt group, preferably a salt of an acidic group, which is capable to render the polyurethane dispersible in water and / or at least one functional group, preferably an acidic group, that can be converted, by reaction with a neutralizing agent, into a salt group which is capable to render the polyurethane dispersible in water is used as component (A2).

[0036] In general, the amount of component (A2) is in the range from 0.5 to 3.5 wt.%, preferably in the range from 0.6 to 2.5 wt.%, more preferably in the range from 0.7 to 2.0 wt.%, relative to the total amounts of components used to prepare the polyurethane from which the building blocks from the polyurethane are emanated.

[0037] In case component (A2) contains at least one functional group that can be converted by reaction with a neutralizing agent into a salt group, the neutralizing agent used to deprotonate (neutralize) the functional groups (preferably carboxylic acid groups, sulfonic acid groups and / or phosphoric acid groups, more preferably carboxylic acid groups) is preferably selected from the group consisting of ammonia, a (tertiary) amine, a metal hydroxide and any mixture thereof. Suitable tertiary amines include triethylamine and N,N- dimethylethanolamine. Suitable metal hydroxides include alkali metal hydroxides, for example lithium hydroxide, sodium hydroxide and potassium hydroxide. Preferably, at least 30 mol%, more preferably at least 50 mol% and most preferably at least 70 mol% of the total molar amount of the neutralizing agent is alkali metal hydroxide, preferably selected from the group consisting of lithium hydroxide, sodium hydroxide, potassium hydroxide and any mixture thereof. Preferably the neutralizing agent used to deprotonate (neutralize) the carboxylic acid groups, sulfonic acid groups and / or phosphoric acid groups is an alkali metal hydroxide. As used herein, the neutralizing agent (if any) is not to be considered a component from which the building blocks of the polyurethane are emanated. Thus, the amount of neutralizing agent (if any) used in the preparation of the polyurethane is not taking into account for the calculation of the weight of the polyurethane.

[0038] According to the present invention, the acidic group is preferably selected from a carboxylic acid group, a sulfonic acid group and / or a phosphoric acid group. Preferably, component (A2) is selected from the group consisting of compounds having two hydroxy groups next to the acidic group(s), compounds having two amino groups next to the acidic group(s), compounds having a hydroxy group and an amino group next to the acidic group(s) and any mixture thereof. Preferred dihydroxy alkanoic acids are a,a-dimethylolpropionic acid and / or a,a-dimethylolbutanoic acid. Preferred diamine carboxylate salts are the addition product of ethylenediamine to acrylic acid, mainly Sodium N-(2-aminoethyl)-[3-alaninate (commercially available as sodium salt under the trade name Disponil ® PUD from BASF SE) and lysine. More preferably, the dihydroxy alkanoic acid(s) is a,a-dimethylolpropionic acid. Most preferably the acidic group is a sulfonic acid group. Preferably, component (A2) contains at least one salt group of a sulfonic acid group and an alkali metal ion, which salt group is capable to render the polyurethane dispersible in water. Examples include the adduct of sodium bisulfite onto but-2-ene-1 ,4-diol, so called polyethersulfonate, which is the propoxylated adduct of unsaturated diols like but-2-ene-1,4-diol and an alkali bisulfite component, described, for example, in US 4, 108, 814 formula (I, II and III, with II being preferred, especially preferred as sodium salt) and 2-(2-aminoethylamino)ethanesulfonic acid, also preferably in the form of its sodium salt.

[0039] In an embodiment of the invention, component (A2) comprises or essentially consists of or consists of at least one diamine sulfonate salt. In this embodiment, usually an isocyanate- terminated polyurethane pre-polymer is first formed by the reaction of components (A1) and (A3) which is then further reacted with the diamine sulfonate salt (A2) and optionally component (A4). A preferred diamine sulfonate salt is the sodium salt of 2-[(2- aminoethyl)amino]ethanesulfonic acid (CAS: 34730-59-1).

[0040] Component (A3)

[0041] At least one isocyanate-reactive polyol other than (A2) is used as component (A3). The amount of (A3) is preferably in the range from 74.5 to 94.5 wt.%, more preferably in the range from 80.5 to 92.8 wt.%, more preferably in the range from 84 to 91.2 wt.%, relative to the total amounts of components used to prepare the polyurethane from which the building blocks from the polyurethane are emanated.

[0042] Component (A3) preferably comprises at least 50 wt.%, more preferably at least 60 wt.%, even more preferably at least 70 wt.%, even more preferably at least 80 wt.%, most preferably at least 90 wt.% of an aliphatic polyester polyol with a hydroxy value of at most 112 mg KOH / g, preferably of at most 75 mg KOH / g, more preferably of at most 64 mg KOH / g, most preferably of at most 56 mg KOH / g, wherein the aliphatic polyester polyol is preferably obtained from (i) one or more diacids selected from the group consisting of succinic acid, methylsuccinic acid, glutaric acid, adipic acid and maleic acid, and (ii) one or more diols selected from the group consisting of propane-1 , 3-diol, butane-1,4-diol, hexane- 1 ,6-diol, epsilon-caprolactone and neopentyl glycol, more preferably the aliphatic polyester polyol is obtained from (i) one or more diacids selected from the group consisting of succinic acid, methylsuccinic acid, glutaric acid, adipic acid and maleic acid and (ii) one or more diols selected from the group consisting of propane-1, 3-diol, butane-1,4-diol and hexane-1,6-diol, even more preferably the aliphatic polyester polyol is obtained from (i) adipic acid and (ii) butane-1,4-diol and / or hexane-1,6-diol, even more preferably the aliphatic polyester polyol is obtained from adipic acid and butane-1 ,4-diol. The aliphatic polyester polyol is preferably an aliphatic polyester diol.

[0043] If the crystalline or semi-crystalline polyester polyols with a hydroxy value of at most 112 mg

[0044] KOH / g and a melting temperature of at least 35 °C have an enthalpy of fusion of at least 33 J / g, the polyurethane-vinyl polymer prepared using the same shall normally have an enthalpy of fusion of equal or higher than 15 J / g. If desired, an adjustment of the enthalpy of fusion of the polyurethane-vinyl polymer can be achieved by a slight change in the content of polyester polyol in the composition or by a slight variation in the enthalpy of fusion of the polyester polyol. These measures require only exploratory experiments and are entirely within the practical experience of the average person skilled in the field. The production of polyester polyols is known from the prior art. The melting temperature of crystalline or semicrystalline polyester polyols is usually at least 35 °C, preferably in the range from 40 to 80 °C, especially preferably in the range from 42 to 60 °C.

[0045] Component (A3) may further comprise one or more polyols with a hydroxy value higher than 112 mg KOH / g, such as for example neopentyl glycol, butane diol, and cyclohexanedimethanol.

[0046] The amount of component (A3) is preferably in the range from 65 to 95 wt.%, more preferably in the range from 75 to 92 wt.%, even more preferably in the range from 80 to 90 wt.%, relative to the total amounts of components used to prepare the polyurethane from which the building blocks from the polyurethane are emanated.

[0047] Component (A4)

[0048] Component (A4) is preferably used for preparing the polyurethane. At least one aminofunctional isocyanate reactive compound other than (A2) is used as component (A4). Examples are monoamines, diamines and polyamines.

[0049] Examples of monoamines are aliphatic and / or alicyclic primary and / or secondary monoamines such as ethylamine, diethylamine, the isomeric propyl- and butylamines, higher linear aliphatic monoamines and cycloaliphatic monoamines such as cyclohexylamine.

[0050] Further examples are aminoalcohols, i.e. compounds containing amino and hydroxyl groups in one molecule, such as for example ethanolamine, N-methylethanolamine, diethanolamine or 2-propanolamine.

[0051] Examples of diamines are ethane-1,2-diamine, hexamethylene-1,6-diamine, 1-amino-3,3,5- trimethyl-5-aminomethylcyclohexane (isophoronediamine), piperazine, hydrazine, 1,4- diaminocyclohexane and bis(4-aminocyclohexyl)methane. Further examples are aminoalcohols, i.e. compounds containing amino and hydroxyl groups in one molecule, such as for example 1,3-diamino-2-propanol, N-(2-hydroxyethyl)ethylenediamine or N,N-bis(2- hydroxyethyl)ethylenediamine

[0052] Examples of polyamines are diethylenetriamine and triethylenetetramine.

[0053] In a preferred form of the invention, the polymer according to the invention contains, for adjusting the molar mass, at least one monoamine and / or at least one diamine as aminofunctional isocyanate reactive compound (A4). The amount of component (A4) is in the range from 0 to 2 wt.%, preferably in the range from 0.1 to 1 wt.%, relative to the total amounts of components used to prepare the polyurethane from which the building blocks from the polyurethane are emanated.

[0054] The polyurethane is preferably obtained by the reaction of components (A1), (A2), (A3) and optionally (A4). In a preferred form of the invention, the polyurethane is the reaction product of from 5 to 20 wt.% of component (A1), from 0.5 to 3.5 wt.% of component (A2), from 74.5 to 94.5 wt.% of component (A3), and from 0 to 2 wt.% of component (A4), wherein the amounts of (A1), (A2), (A3) and (A4) add up to 100 wt.%. In a more preferred form of the invention, the polyurethane is the reaction product of from 6.5 to 16 wt.% of component (A1), from 0.6 to 2.5 wt.% of component (A2), from 80.5 to 92.8 wt.% of component (A3), and from 0.1 to 1 wt.% of component (A4), wherein the amounts of (A1), (A2), (A3) and (A4) add up to 100 wt.%. In a particularly preferred form of the invention, the polyurethane is the reaction product of from 8 to 13 wt.% of component (A1), from 0.7 to 2.0 wt.% of component (A2), from 84 to 91.2 wt.% of component (A3), and from 0.1 to 1 wt.% of component (A4), wherein the amounts of (A1), (A2), (A3) and (A4) add up to 100 wt.%.

[0055] The polyurethane-vinyl polymer preferably comprises reacted hexamethylene diisocyanate and / or reacted 1,5-pentamethylene diisocyanate in an amount in the range from 1 to 15 wt.%, preferably in the range from 1 to 12 wt.%, more preferably in the range from 1.5 to 10 wt.%, most preferably in the range from 2 to 8 wt.%, relative to the polyurethane-vinyl polymer.

[0056] The polyurethane-vinyl polymer preferably has an acid value in the range from 0.6 to 20 mg KOH / g, more preferably in the range from 0.6 to 10 mg KOH / g, even more preferably in the range from 0.7 to 7 mg KOH / g, even more preferably in the range from 0.7 to 4 mg KOH / g, most preferably in the range from 0.8 to 3 mg KOH / g, especially preferred in the range from 0.8 to 2.7 mg KOH / g. As used herein, the acid value is calculated.

[0057] The polyurethane-vinyl polymer preferably has a hydroxy value in the range from 0.5 to 20 mg KOH / g, more preferably in the range from 1 to 12 mg KOH / g, even more preferably in the range from 1.5 to 10 mg KOH / g, even more preferably in the range from 2 to 7 mg KOH / g, most preferably in the range from 2 to 5 mg KOH / g.

[0058] As used herein, the hydroxy value of a component is measured by titration a known mass of component according to ASTM D4274 and is expressed as mg KOH / g. The weight average molecular weight Mw of the polyurethane-vinyl polymer is preferably at least 10 kDalton, more preferably at least 20 kDalton, most preferably at least 40 kDalton, preferably at most 800 kDalton, more preferably at most 650 kDalton, most preferably at most 500 kDalton. As used herein, the weight average molecular weight is determined with the method as described further herein.

[0059] The z-average particle size of the dispersed particles present in the waterborne adhesive composition used in the present invention is preferably in the range from 30 to 600 nm, more preferably in the range from 50 to 400 nm, even more preferably in the range from 70 to 350 nm, most preferably in the range from 110 to 275 nm, wherein the z-average particle size is determined with the method as described further herein.

[0060] The polydispersity (Mw / Mn) of the dispersed particles present in the waterborne adhesive composition used in the present invention is preferably in the range from 9 to 50, more preferably in the range from 10 to 40, even more preferably in the range from 10 to 35, wherein the polydispersity is determined with the method as described further herein.

[0061] In a preferred embodiment of the invention, the polyurethane-vinyl polymer comprises from 1 to 15 wt.% of reacted hexamethylene diisocyanate and / or reacted 1 ,5-pentanediisocyanate, whereby the amount of reacted hexamethylene diisocyanate and / or reacted 1 ,5- pentanediisocyanate is given relative to the total amount of components used to prepare the polyurethane-vinyl polymer from which the building blocks from the polyurethane-vinyl polymer are emanated; component A3 comprises at least 50 wt.% of an aliphatic polyester polyol with a hydroxy value of at most 112 mg KOH / g that is preferably obtained from (i) succinic acid, methylsuccinic acid, glutaric acid, adipic acid and / or maleic acid, and (ii) propane-1, 3-diol, butane-1,4-diol, hexane-1 ,6-diol, epsilon-caprolactone and / or neopentyl glycol; the acid value of the polyurethane-vinyl polymer is in the range from 0.6 to 20 mg KOH / g; and the polyurethane-vinyl polymer particles have a z-average particle size in the range from 30 to 600 nm.

[0062] The waterborne adhesive composition used in the present invention optionally comprises plasticizer in an amount of less than 15 wt.%, preferably less than 12 wt.%, more preferably less than 10 wt.%, more preferably less than 8 wt.%, more preferably less than 5 wt.%, more preferably less than 2 wt.%, more preferably less than 1 wt.%, more preferably less than 0.5 wt.%, more preferably less than 0.1 wt.%, relative to the solids content of the waterborne adhesive composition, most preferably the waterborne adhesive composition is free of plasticizer. Suitable plasticizers are non-volatile, low molecular weight compounds bearing polar group(s). If present, the plasticizer is preferably at least one compound selected from the group consisting of di(phenoxyethyl)formal, dialkyl adipate, dialkyl terephthalate, dialkyl phthalate, dialkyl succinate, alkylsulfonic ester of phenol and esters based on benzoic acid, preferably dibenzoate, more preferably dipropylene glycol dibenzoate. More preferably, the plasticizer, if present, comprises, consists essentially of, or consists of dipropylene glycol dibenzoate, commercially available as for example Benzoflex™ 9-88 SG or Benzoflex™ LA- 705.

[0063] The waterborne adhesive composition used in the present invention optionally comprises tackifier resin in an amount of less than 10 wt.%, relative to the solids content of the waterborne adhesive composition. The tackifier resins used, if any, may be natural or synthetic resins, for example aliphatic, aromatically modified, aromatic and hydrogenated hydrocarbon resins, terpene resins, modified terpene resins and terpene-phenol resins, or tree resin derivatives such as rosins, modified rosins such as resin esters based on rosin (rosin esters), balsam resin derivatives (gum rosin) and tall oil derivatives (tall oil rosin). The tackifier resins can be used individually or in mixtures. The tackifier resins used, if any, are preferably rosins and modified rosins. Particular preference is given to using resin esters based on rosin. The tackifiers can be used as 100 percent resins or as a dispersion in the waterborne adhesive compositions used in the present invention, so long as compatibility (e.g. stability against phase separation) is provided.

[0064] The waterborne adhesive composition used in the present invention preferably has a solids content of at least 15 wt.%, more preferably of at least 20 wt.%, more preferably of at least 25 wt.%, more preferably of at least 30 wt.%, more preferably of at least 35 wt.%, more preferably of at least 40 wt.%, most preferably of at least 45 wt.% and preferably of at most 70 wt.%, more preferably of at most 65 wt.%, even more preferably of at most 60 wt.% or of at most 55 wt.%.

[0065] The polyurethane and the vinyl polymer are preferably present in the waterborne adhesive composition in a total amount of at least 65 wt.%, more preferably of at least 70 wt.%, more preferably of at least 75 wt.%, more preferably of at least 80 wt.%, more preferably of at least 85 wt.%, more preferably of at least 90 wt.%, more preferably of at least 95 wt.%, more preferably of at least 99 wt.% or in a total amount of 100 wt.%, relative to the solids content of the waterborne adhesive composition.

[0066] The present invention further relates to a process for preparing the waterborne adhesive composition used in the present invention. The process preferably comprises preparing an aqueous dispersion of the polyurethane; vinyl monomer is added before, during or after preparation of the polyurethane; and a free radical initiator is added to polymerize the vinyl monomer in the presence of the polyurethane.

[0067] In the preferred embodiment of the invention in which component (A2) comprises or essentially consists of or consists of at least one diamine sulfonate salt, the process for preparing the aqueous adhesive composition used in the present invention preferably comprises at least the following steps:

[0068] 1) Preparing a polyurethane pre-polymer by reacting (A1) and (A3).

[0069] 2) Preparing a polyurethane by reacting the polyurethane pre-polymer with (A2) and (A4),

[0070] 3) Preparing an aqueous dispersion of the polyurethane by adding water to the polyurethane obtained in step 2) and / or adding the polyurethane obtained in step 2) to water,

[0071] 4) Adding one or more vinyl monomers during and / or after step 3), and

[0072] 5) Preparing a vinyl polymer by polymerizing the one or more vinyl monomers in the presence of the polyurethane, thereby obtaining the polyurethane-vinyl polymer hybrid.

[0073] Step 1) and / or step 2) is preferably carried out in the presence of a water-miscible organic solvent, preferably acetone and / or methyl ethyl ketone, more preferably acetone. The water- miscible organic solvent is preferably at least partly removed after or during step 3). The vinyl monomer(s) are preferably added after step 3).

[0074] The amount of water-miscible organic solvent added in the process is preferably at least 30 wt.%, preferably at least 40 wt.%, more preferably at least 50 wt.%, relative to the total amounts of components used to prepare the polyurethane from which the building blocks from the polyurethane are emanated.

[0075] The present invention further relates to the use of the waterborne adhesive composition as described herein for the adhesive bonding of one or more substrates after at least partial coagulation of the waterborne adhesive composition and while the at least partially coagulated waterborne adhesive composition is still in a wet state, wherein the waterborne adhesive composition is applied to at least a part of at least one the surfaces of the substrate or of the substrates to be adhesively bonded by rolling, brushing or spraying, more preferably by rolling or spray coagulating, particularly preferably by spray coagulating. The present invention further relates to the use of the waterborne adhesive composition as described herein for the adhesive bonding of one or more substrates after at least partial coagulation of the waterborne adhesive composition and while the at least partially coagulated waterborne adhesive composition is still in a wet state, wherein the adhesive bonding is effected at a temperature below the melting temperature of the polyurethane-vinyl polymer and preferably at ambient temperature (i.e. in the adhesive bonding process, the temperature of the adhesive layer is below the melting temperature of the polyurethane-vinyl polymer and preferably is at ambient temperature), and wherein the waterborne adhesive composition is applied to at least a part of at least one the surfaces of the substrate or of the substrates to be adhesively bonded by rolling, brushing or spraying, more preferably by rolling or spray coagulating, particularly preferably by spray coagulating. A two-component adhesive is preferably used in the coagulating process, wherein one of the components of the two-component adhesive is the waterborne adhesive composition as described herein.

[0076] The present invention further relates to a one-component adhesive composition for the adhesive bonding of one or more substrates, wherein the one-component adhesive composition comprises the waterborne adhesive composition as described herein , wherein the adhesive bonding is effected after at least partial coagulation of the waterborne adhesive composition and while the at least partially coagulated waterborne adhesive composition is still in a wet state. The one-component adhesive composition optionally comprises a destabilizer for the dispersion and / or optionally comprises a plasticizer.

[0077] The present invention also relates to a two-component adhesive composition for the adhesive bonding of one or more substrates, wherein the two-component adhesive composition consists of a first component and a second component, wherein the first component comprises, consists essentially of, or consists of the waterborne adhesive composition as described herein; and the second component comprises a coagulant, and wherein the adhesive bonding is effected after at least partial coagulation of the waterborne adhesive composition and while the at least partially coagulated waterborne adhesive composition is still in a wet state.

[0078] The present invention also relates to a process for adhesive bonding of one or more substrates comprising

[0079] 1) applying and coagulating a waterborne adhesive composition as described herein on at least a part of at least one of the surfaces of the substrate or of the substrates to be adhesively bonded to obtain an at least partially coagulated adhesive film in a still wet state that is ready for bonding, wherein said applying and at least part of the coagulating of the waterborne adhesive composition is preferably effected by rolling, brushing or spraying, 2) disposing the surfaces one on the other,

[0080] 3) optionally contact pressing them together at a temperature below the melting temperature of the polyurethane-vinyl polymer, preferably at ambient temperature, and

[0081] 4) drying the adhesive film to constant weight to obtain a dried adhesive film.

[0082] The waterborne adhesive compositions as described herein are preferably used for adhesive bonding by the spray coagulation process using a two-component adhesive composition. In this process, the waterborne adhesive composition and a coagulant are conveyed separately into a two-component spray gun and mixed in the spray jet. Spraying is typically effected using atomizer air at 0.1-5 bar of pressure; however, it is also possible to deliver at least one of the two components airlessly, as described for example in WO 2015 / 137808. The coagulation of the dispersion takes place in the spray jet on the path to the surface of the substrate to be adhesively bonded; a portion of the water present in the adhesive dispersion already evaporates in the process. On impact, the polymer forms on the surface of the substrate on which it is applied, a film which is immediately tacky in the still-wet state. On account of the tackiness of the polymer film in the wet state, the second surface can be immediately joined, ideally for example with pressure on the substrates towards the adhesive surface. The application of pressure by pressing the two surfaces together is advantageous since it increases the strength of the bond. It is likewise advantageous when the substrate or, in case two substrates are adhesively to be bonded, at least one of the two substrates is porous or permeable to water, in order to allow for the transport of water away out of the solidifying adhesive joint.

[0083] The present invention also relates to a process for adhesive bonding of one or more substrates wherein the process comprises applying an adhesive composition as described herein on at least a part of at least one of the surfaces of the substrate or of the substrates to be adhesively bonded and bonding then takes place at a temperature below the melting temperature of the polyurethane-vinyl polymer, preferably at ambient temperature. Preferably said process comprises

[0084] - spray coagulating the waterborne adhesive composition as described herein in a spray jet onto on at least a part of at least one of the surfaces of the substrate or of the substrates to be adhesively bonded to obtain an adhesive film,

[0085] - disposing the surfaces one on the other,

[0086] - optionally contact pressing them together at a temperature below the melting temperature of the polyurethane-vinyl polymer, preferably at ambient temperature, and

[0087] - drying the adhesive film to constant weight to obtain a dried adhesive film. Preferably said process comprises a) conveying the waterborne adhesive composition as described herein and a coagulant separately into a spray gun, b) mixing the waterborne adhesive composition and the coagulant in a spray jet, b) coagulating the waterborne adhesive composition in the spray jet (on the path to the surface of the substrate) to obtain an at least partially coagulated composition, c) spraying the at least partially coagulated composition onto at least a part of at least one of the surfaces of the substrate or of the substrates to be adhesively bonded to obtain an adhesive film (which is immediately tacky in the still-wet phase), d) disposing the surfaces one on the other, e) optionally contact pressing them together at a temperature below the melting temperature of the polyurethane-vinyl polymer, preferably at ambient temperature, and f) drying the adhesive film to constant weight to obtain a dried adhesive film.

[0088] The process is preferably applied for adhesively bonding of foam in mattress, furniture and / or upholstery manufacturing.

[0089] Suitable coagulants include aqueous solutions of salts, preferably of metals of the first, second and third main group of the Periodic Table, in particular if they exhibit a good water solubility. Salts based on divalent or trivalent cations are preferably used. Particular preference is given to calcium chloride, zinc sulfate or aluminum sulfate. Very particular preference is given to calcium chloride. Mixtures of different salts as per the above description can also be used as the aqueous solution. The concentration of the salts in the aqueous salt solutions suitable as coagulant is generally in the range from 1 to 20 wt.%, preferably in the range from 2 to 10 wt.% and particularly preferably in the range from 3 to 4 wt.%. The proportion of the aqueous solution of the coagulant, based on the sum of adhesive composition plus coagulant solution, is preferably in the range from 0.1 to 50 wt.%, more preferably in the range from 1 to 30 wt.%, particularly preferably in the range from 8 to 20 wt.% and very particularly preferably in the range from 12 to 18 percent wt.%.

[0090] Alternatively, coagulants used may also be aqueous solutions of inorganic or organic acids, preferably citric acid, phosphoric acid or carbonic acid, and mixtures of one or more of the abovementioned salts with one or more of these acids

[0091] The present invention further relates to one or more substrates adhesively bonded with the waterborne adhesive composition as described herein, wherein the substrate(s) are composed of foam, wood, paper, leather, textiles, cork or plastics. Preferably, the substrates comprise a first substrate that is foam or textile, adhesively bonded to a second substrate that is foam, wood or plastic. More preferably, at least one of the first or the second substrate is a foam substrate, preferably polyurethane foam or foam rubber.

[0092] A foam substrate is understood to mean a substrate made of foam, foams generally being synthetically produced substances having a cellular structure and low density. A distinction can be made here between open-cell, closed-cell and mixed-cell foams. Preference is given to adhesively bonding open-cell and mixed-cell foam substrates. In a preferred embodiment of the invention, the foam substrate(s) is / are composed of polyurethane (and / or a rubber, such as for example natural rubber (NR), styrene-butadiene rubber (SBR), ethylene- propylene-diene polymer (EPDM) or butadiene-acrylonitrile rubber (NBR). In a particularly preferred embodiment of the invention, the foam substrate(s) is / are composed of polyurethane

[0093] The present invention further relates to a mattress comprising substrates adhesively bonded with the waterborne adhesive composition as described herein, wherein the substrates are polyurethane foam or foam rubber.

[0094] The present invention is now illustrated by reference to the following examples. Unless otherwise specified, all parts, percentages and ratios are on a weight basis.

[0095] Components and abbreviations used:

[0096] Polyester I: polyester diol formed from butane-1 ,4-diol and adipic acid having an OH number=50 mg KOH / g

[0097] Polyester II: polyester diol formed from neopentyl glycol, adipic acid and hexane diol having an OH number= 66 mg KOH / g

[0098] Polyester III: polyester diol formed from hexane-1,6-diol and phthalic anhydride having an OH number=56 mg KOH / g

[0099] Desmodur® H: hexamethylene-1,6-diisocyanate (Covestro Deutschland AG, Leverkusen / Germany)

[0100] Desmodur® I: isophorone diisocyanate (Covestro Deutschland AG, Leverkusen / Germany) Lucramul® 1820: non-ionic dispersant and emulsifier (Levaco Chemicals). The following methods and test methods were used here:

[0101] 1C-Spray coagulation process:

[0102] The adhesive formulation was evenly applied over the entire surface with a standard spray gun for one-component dispersion adhesives (Walther Pilot GM 1030P). The application weight was determined by weighing the substrates before and immediately after application. The following settings of the spray gun were used:

[0103] Adhesive formulation: Discharge pressure 0.2 bar

[0104] Atomizer air pressure: 3 bar

[0105] Bore (nozzle) for adhesive component 1.0 mm

[0106] Rotation of the material nozzle 0.5 turn

[0107] Application weights: 100 g / m2(wet)

[0108] 2C-Spray coagulation process:

[0109] A standard spray gun for two-component dispersion adhesives, PILOT III 2K from Walther Pilot, was used for application. The adhesive and the coagulant CaCh (3% by weight solution in water) were conveyed separately into the spray gun, mixed in the spray jet and the adhesive was coagulated. A ratio of 86% by weight adhesive dispersion and 14% by weight CaCh solution was chosen.

[0110] The precise settings of the spray gun are known in principle to the person skilled in the art and can be tailored to the specific case without undue burden and determined by simple preliminary experiments. The guantitative ratios and the application weight can be determined by reweighing the reservoir vessel and the substrates.

[0111] The following settings were used: a. Adhesive component: conveying pressure 1.5 bar b. Coagulation component: conveying pressure 0.2 bar c. Atomizer air pressure: 2.8 bar d. Bore diameter (nozzle) for adhesive component: 1.0 mm e. Bore diameter (nozzle) for coagulant component: 0.4 mm f. Application weights: 140 g / m2(wet), 8:1 ratio of adhesive to coagulant by weight

[0112] Brushing test: Separate application of coagulant and adhesive

[0113] As test material, ST 5540 (1) Pll foam test specimens from STN Schaumstoff-Technik- Nurnberg GmbH having the dimensions 10 x 5 x 3 cm and a foam density of 40 kg / m3were used (see Figure 1). On one of the 10 x 5 cm areas of the foam specimen 1 g of a 3 weight% CaCI2 solution in water were evenly applied by brushing. The foam specimen was dried at 23°C / 50% relative humidity for 24h. On top of the CaCI2 coating, the tested formulation was evenly applied by brushing with a coating weight of 160 g / m2. Immediately after application the coated side was brought into full contact with itself by folding the specimen along an axis perpendicular to the long side, yielding a bonding area of 5 cm x 5 cm = 25 cm2. The specimen was compressed by hand pressure to maximal compression for 10 seconds. The initial strength is sufficient (“ok”) if the bond seam does not open more than 5 mm measured from the front end of the seam despite the restoring forces present in the test specimen. The initial strength is not sufficient (“fail”) if the bond seam opens completely.

[0114] Determination of the initial strength

[0115] Pll foam test specimens from STN Schaumstoff-Technik-Nurnberg GmbH having the dimensions 10 x 5 x 3 cm and a foam density of 40 kg / m3were used (see Figure 1 and 2). For assessment of the initial strength, immediately after application of the adhesive to the upper side (2) of the foam bodies (1) by the spray coagulation process (coating weight 130 - 150 g / m2wet), the test specimens were folded (4) in the middle with a wooden rod (3) (D = 7 mm round wood or 7 x 7 mm rectangle) and fed by means of the test apparatus (5) through 2 steel rolls (6) (diameter 40 mm, length 64 mm) the tangential spacing (7) of which was previously set to 10 mm using a threaded spindle (8). The initial strength was rated” excellent” if the test specimen or the bond seam (9) did not open despite the restoring forces present in the test specimen. It was rated “sufficient” if it opened and could be bonded by passing it a second time through the steel rolls, in case it opened a second time, it was rated ’’fail”.

[0116] Determination of the open time

[0117] As test material, Recticel T 20120 polyether foam bodies from Recticel having the dimensions 10 x 5 x 3 cm and a foam density of 20 kg / m3were used. On a sufficient number of test specimens the adhesive was evenly applied by the 2C-spray coagulation or 1C-spray coagulation process (coating weight 130 - 150 g / m2) and the specimens were stored at 23°C and 50% relative humidity for the time indicated below.

[0118] To assess the open time, the test specimens were folded in the middle and joined together with light palm pressure for 10 seconds and checking if the test specimens open again within 15 seconds.

[0119] This test was done with one specimen immediately after application of the formulation and repeated every 60 seconds with a new specimen, or if necessary at time intervals to be defined, after the application of adhesive by means of the spray coagulation process (application rate 130 - 150 g / m2wet). The end of the open time is indicated by the strength no longer sufficing and the test specimen fully opening as a result of the restoring forces. Determination of glass transition temperatures, melting temperatures and melting enthalpies by means of Differential Scanning Calorimetry (DSC):

[0120] The glass transition temperatures, melting temperatures and melting enthalpies were determined using Differential Scanning Calorimetry (DSC) with a DSC Q2000 calorimeter from TA Instruments.

[0121] The determination was carried out in accordance with DIN EN ISO 11357-1 :2017 (2017-02) - Plastics - Dynamic differential thermal analysis (DSC) - Part 1 : General principles (ISO 11357-1 :2016); German version EN ISO 11357-1:2016 and the standard parts

[0122] DIN EN ISO 11357-2:2020-08 - Plastics - Differential scanning calorimetry (DSC) - Part 2: Determination of glass transition temperature and glass transition step height (ISO 11357- 2:2020); German version EN ISO 11357-2:2020

[0123] DIN EN ISO 11357-3:2018-07 - Plastics — Differential dynamic thermal analysis (DSC) — Part 3: Determination of melting and crystallization temperature and enthalpy of melting and crystallization (ISO 11357-3:2018).

[0124] Sample preparation for aqueous dispersions

[0125] A film was prepared by applying the dispersion with 100 pm wet film thickness on a glass plate using a doctor blade, pre-dried for 2 hours at 23°C and 50% relative humidity, the coated glass plate was then transferred to a drying box and stored there for 3 days at 23°C and 0% relative humidity.

[0126] The coated glass plate was removed from the drying box, coating was scraped from the glass plate and approx. 5 mg of this sample material is used for the DSC measurement. The following measurement program was carried out:

[0127] Rapid cooling to the starting temperature -100 °C, then start of three heats from -100 °C to +150 °C with a heating rate of 20 K / min and the maximum cooling rate under nitrogen atmosphere and cooling with liquid nitrogen.

[0128] Determination of glass transition temperatures

[0129] The glass transition temperatures (Tg) were determined in accordance with DIN EN ISO 11357-2:2020-08

[0130] The glass temperature corresponds to the temperature at half the height of the glass transition, whereby the third heating was evaluated. If no glass transition temperature can be determined, the measuring program was changed as follows. Rapid cooling to the starting temperature -140 °C, then start of three heats from -140 °C to +150 °C with a heating rate of 20 K / min and the maximum cooling rate of under nitrogen atmosphere and cooling with liquid nitrogen.

[0131] Determination of melting temperatures The first heating was used to determine the melting temperatures, the specified melting temperatures correspond to the peak crystallization temperatures.

[0132] Determination of the enthalpies of melting

[0133] To determine the enthalpies of melting, the first heating was used. In the case of multiple melt peaks, the melt enthalpies of all melt peaks were added with a peak melting temperature Tp,m in the range of 15 to 80 °C. Peaks with melt fractions of < 0.9 J / g were not considered.

[0134] Hydroxy value

[0135] The hydroxy value of a component was measured by titration a known mass of component according to ASTM D4274 and is expressed as mg KOH / g.

[0136] Acid value of the hybrid

[0137] The acid value of the polyurethane-vinyl polymer hybrid (mg KOH / g hybrid) refers to the amount of acid groups present in the polyurethane-vinyl polymer hybrid and was calculated as follows:

[0138] Molar amount of acid groups present in 1 g solid polyurethane-vinyl polymer x 56100, i.e. the product obtained by multiplying the molar amount of acid groups present in 1 g solid polyurethane-vinyl polymer by 56100.

[0139] Average particle size PS:

[0140] The intensity average particle size, z-average, has been determined by photon correlation spectroscopy using a Malvern Zetasizer Nano ZS. Samples were diluted in demineralized water to a concentration of approximately 0.1 g dispersion / liter. Measurement temperature 25°C. Angle of laser light incidence 173°. Laser wavelength 633 nm.

[0141] £H

[0142] The pH was measured using a Metrohm pH meter.

[0143] Solids

[0144] The solid content of the dispersion was measured on a HB43-S halogen moisture analyzer from Mettler Toledo at a temperature of 75°C.

[0145] Viscosity

[0146] The viscosity was determined with a Brookfield DV-I viscometer (spindle S61 , 60 rpm, 23°C). Size exclusion chromatography in NMP

[0147] The number average molecular weight Mn, weight average molecular weight Mwand molecular weight distribution was determined with Size exclusion chromatography (SEC), using three PLgel 10 pm Mixed-B columns at 70°C on a Waters Alliance e2695 LC system with a Waters 2414 DRI detector. N-Methylpyrrolidone (NMP) and 10 mM lithiumbromide (LiBr) was used as eluent with a flow of 1 mL / min. The samples were dissolved in the eluent using a concentration of 5 mg polymer per mL solvent. The solubility was assessed with a laser pen after 24 hours stabilization at room temperature; if any scattering was visible the samples were filtered first and 100 pl sample solution was injected. The MMD (molecular mass distribution) results were calculated with 12 narrow polystyrene standards from 370 to 1.071.000 Da.

[0148] In general, a series of average molecular weights can be defined by the equation: M= SNiMn+1 / SNiMin, whereby: n=0 gives M= Mn; n = 1 gives M = Mw, n = 2 gives M = Mz.The higher averages are increasingly more sensitive to high molecular weight polymers. Nj is the number of molecules with molecular weight Mj.

[0149] Preparation of aqueous polyurethane dispersion PUD A

[0150] 450 g of polyester I was kept for 1 hour at 110 degrees centigrade and 15 mbar. At 80 degrees centigrade, 30.11 g of Desmodur® H and then 20.14 g of Desmodur® I were added. The mixture was stirred at 80 to 90 degrees centigrade until a constant isocyanate content of 1.15 percent has been reached. The reaction mixture was dissolved in 750 g of acetone and cooled to 48 degrees centigrade. Into the homogeneous solution was added a solution of 5.95 g of the sodium salt of N-(2-aminoethyl)-2-aminoethanesulfonic acid and 2.57 g of diethanolamine in 65 g of water with vigorous stirring. After 30 minutes, the mixture was dispersed by addition of 700 g of water. Distillative removal of the acetone affords an aqueous polyurethane dispersion A having a solids content of 40.0 percent by weight.

[0151] The polymer present was semicrystalline after drying with a glass transition temperature Tg of -54 degrees centigrade, a melting temperature of 48 degrees centigrade and an enthalpy of fusion of 50.4 J / g.

[0152] Preparation of aqueous polyurethane dispersion PUD B 563.5g of polyester I and 57.4g of polyester II were kept at 110° C and 15 mbar for 1 hour. Then, 3.5g of 1,4-butanediol were added and cooled while stirring. 55.7g of Desmodur®H were added at 60°C, then 30.4g of Desmodur® I were added, and stirred at 80°C to 90°C until reaching an isocyanate content of 1.3 %. It was then dissolved in 1121g of acetone and cooled to 50°C to obtain a reaction solution. A solution of 10.9g sodium salt of N-(2- aminoethyl)-2-aminoethanesulfonic acid AAS and 2.9g of diethanolamine in 80g water was added to the reaction solution and stirred vigorously for 30 minutes. Then, 669g of water were added for dispersing. Subsequently, acetone was distilled off. After the acetone content was less than 1%, 38.6 g Lucramul® 1820 solution was added under stirring to obtain the aqueous polyurethane dispersion B with solid content of 50% by weight and enthalpy of fusion of 43.0 J / g.

[0153] Preparation of aqueous polyurethane dispersion PUD C

[0154] 414 g of polyester I and 92 g of polyester III were kept at 120°C under vacuum for 1 hour in a 2,5 liter vessel. 34.62 g of Desmodur® H were added at 80°C, followed by 23.16 g of Desmodur® I. The mixture was stirred at 80°C until a constant isocyanate content of 1.1 to 1.2% was reached. The reaction mixture was dissolved in 862.5 g of acetone and cooled to 50°C. A solution of 6.8 g of sodium salt of N-(2-aminoethyl)-2-aminoethanesulfonic acid (0.036 mol) and 2.95 g of diethanolamine (0.028 mol) in 60 g of water was added to the homogeneous solution whilst stirring. After 7 minutes the mixture was dispersed by adding 759.8 g of water heated to 20°C. After separating off the acetone by distillation a solvent- free, aqueous polyurethane dispersion C was obtained with a solids content of 40 wt.%.

[0155] Preparation of aqueous polyurethane dispersion PUD D

[0156] 310.5 g of polyester I and 184 g of polyester III were kept at 120°C under vacuum for 1 hour in a 2,5 liter vessel. 34.62 g of Desmodur® H were added at 80°C, followed by 23.16 g of Desmodur® I. The mixture was stirred at 80°C until a constant isocyanate content of 1.1 to 1.2% was reached. The reaction mixture was dissolved in 862.5 g of acetone and cooled to 50°C. A solution of 6.8 g of sodium salt of N-(2-aminoethyl)-2-aminoethanesulfonic acid (0.036 mol) and 2.95 g of diethanolamine (0.028 mol) in 60 g of water was added to the homogeneous solution whilst stirring. After 7 minutes the mixture was dispersed by adding

[0157] 742.5 g of water heated to 20°C . After separating off the acetone by distillation a solvent- free, aqueous polyurethane dispersion D was obtained with a solids content of 40 wt.%.

[0158] Preparation of aqueous polyurethane dispersion PUD E

[0159] 1215 g of polyester III were kept for 1 hour at 110 degrees centigrade and 15 mbar. At 80 degrees centigrade, 4.6 g of hexane-1,6-diol and 179.0 g of Desmodur® H were added and the mixture was stirred at 90 degrees centigrade until a constant isocyanate content of 2.28 percent has been reached. The reaction mixture was dissolved in 2490 g of acetone and cooled to 48 degrees centigrade. Into the homogeneous solution was added a solution of 31.9 g of the sodium salt of N-(2-aminoethyl)-2-aminoethanesulfonic acid in 300 g of water with vigorous stirring. After 30 minutes, the mixture was dispersed by addition of 1150 g of water. Distillative removal of the acetone affords an aqueous polyurethane dispersion E having a solids content of 50 percent by weight.

[0160] The polymer present was amorphous after drying (does not have a melting peak in DSC) and has a glass transition at a glass transition temperature Tg of -1 .5 degrees centigrade.

[0161] Examples 1-12 and Comparative Examples C1-C5

[0162] Example 1 : Preparation of polyurethane-vinyl polymer hybrid dispersion

[0163] In a 3 liter flask 1821.7 gram of the polyurethane dispersion PUD A was mixed 69.2 g MMA and 415.4 g BA under nitrogen atmosphere. After 60 minutes a mixture of tBHPO (3.46 g (70% in water)) and FeEDTA (2.42 g (1 % solution in water)) and 11.3 g of deionized water was added. Subsequently, a solution of iAA acid in water (1 %, 146.1 g) neutralized with ammonia just above pH 8, was slowly fed to the PU dispersion via a dropping funnel over a period of 45 minutes. The resulting polyurethane-vinyl polymer hybrid dispersion had a solid content of 48.8 wt% solids and a pH of 7.1.

[0164] The acid value of the polyurethane-vinyl polymer hybrid was calculated as follows:

[0165] 1 . Determining weight % of acid groups present in the polyurethane prepared in PUD A,

[0166] 1.e., weight % of AAS present in the polyurethane prepared in PUD A:

[0167] (5.95x100) / (450+30.11+20.14+5.95+2.57) = 1.17 wt% s / s.

[0168] 2. Determining weight amount (gram) of solid polyurethane-urea-vinyl polymer hybrid prepared in example 1 :

[0169] 2.1 . Determining weight amount of solid PU prepared in PUD A:

[0170] 1821.7 g of the PU dispersion with 40.0% solids content is used in example 1 , i.e., = 0.4 x 1821.7 = 728.7 gram of solid PU.

[0171] 2.2. Determining weight amount of solid polyurethane-urea-vinyl polymer hybrid prepared in example 1 is the sum of the weight amount of solid PU prepared in PUD A and the weight amount of the vinyl monomers added in example 1 , i.e.,

[0172] [728.7 g (solid PU) + 69.2 g (MMA) + 415.4 g (BA)] = 1213.3 g of solid polyurethane-urea- vinyl polymer hybrid.

[0173] 3. Determining amount of acid groups present in the polyurethane prepared in PUD A and used in example 1 : (1.17 / 100) x 728.7 = 8.53 g.

[0174] Thus, the solid PU prepared in PUD A and used in example 1 contains 8.53 grams of acid groups and consequently also the resulting polyurethane-vinyl polymer hybrid prepared in example 1 contains 8.53 grams of acid groups. 4. Determining the acid value of the polyurethane-vinyl polymer hybrid prepared in example 1 :

[0175] Molar mass AAS = 190.2 g / mol,

[0176] [(8.53 / 190.2) / 1213.3] x 56100 = 2.1 mg KOH / g.

[0177] Table 1 specifies the components and its amounts applied for preparing the polyurethane- vinyl polymer hybrid dispersions according to Examples 1 to 12 and Comparative Examples C2 to C5. Unless specified otherwise, the amounts of the different components are expressed in grams.

[0178] Example 3 as described in CN107779143A was reproduced. At 80°C the viscosity of the reaction mixture already was very high and the reaction mixture solidified and gelled upon cooling the reaction mixture to 30°C, before the subsequent process step of adding the neutralizing agent triethylamine.

[0179] Example 3 as described in CN 107779143A was again reproduced, however, with the difference that before cooling the reaction mixture, 35% (w / w) of acetone was added to the reaction mixture. Dissolution of the reaction mixture in acetone took 3 hours, subsequently the triethylamine was added and stirred for 30 minutes, and deionized water was added under stirring. Subsequently the acetone was removed by distillation under reduced pressure and this way it was possible to obtain the water-based polyurethane emulsion (polyurethane dispersion PUD F) with the same chemical composition as described in Example 3 of CN 107779143A with a solid content of 32.1 wt.%. In the next step the corresponding polyurethane-acrylate composite emulsion was reproduced as described in CN 107779143A although due to very high viscosity during synthesis the 60 wt.% solid content could not be achieved, and the solid content had to be decreased substantially for a manageable viscosity. Solid content of the water-based polyurethane-acrylate composite emulsion with the same chemical composition as described in Example 3 of CN 107779143A was 21.7 wt.% only with a viscosity of 1380 mPa.s. Table 1 : Compositions of polyurethane-vinyl polymer hybrid of Ex. 1 to 7

[0180] Table 1 continued: Compositions of polyurethane-vinyl polymer hybrid of Ex. 8 to 12 Table 1 continued: Compositions of polyurethane-vinyl polymer hybrid of Comparative Examples C2 to C7 The specifications of the resulting polyurethane-vinyl polymer hybrids are illustrated in Table 2.

[0181] Table 2: Specifications of UA Ex.1 to 7

[0182] Table 2 continued: Specifications of UA Ex.8 to 12

[0183] Table 2 continued: Specifications of Comparative Examples C1 to C7

[0184] Preparation of adhesive formulations

[0185] Formulations not comprising plasticizer (UA)

[0186] The dispersions were stirred with a spatula before use.

[0187] Formulations comprising plasticizer (FUA)

[0188] The adhesive formulations were produced in a 900 ml polycup with a VISCO JET® stirrer. At the beginning, 190 g of the dispersion was stirred at a stirring speed of approx. 600 rpm for 3 minutes, and then 10 g of Benzoflex™ 9-88 SG (main component is dipropylene glycol dibenzoate (CAS-Nr. 27138-31-4, Eastman) was added while stirring and stirred for 120 minutes. After the addition of the plasticizer and in the course of the mixing process, the viscosity increases sharply. The stirring speed was constantly adjusted to a minimal value that yields a visible vortex around the stirrer.

[0189] Table 3: Brushing test results of the polyurethane-vinyl polymer hybrid dispersions coagulated during UA synthesis

[0190] Table 4: Test results of the polyurethane-vinyl polymer hybrid UA Ex.1 and formulation FUA

[0191] Ex.1 based on UA Ex.1 in a 2C-Spray coagulation test Table 5: Test results of the polyurethane-vinyl polymer hybrid UA Ex.1 and formulation FUA

[0192] Ex.1 based on UA Ex.1 in a 1C-Spray coagulation test

[0193] The invention is further defined by the following exemplary embodiments as listed hereafter. Any one of the embodiments, aspects and preferred features or ranges as disclosed in this application may be combined in any combination, unless otherwise stated herein or if technically not feasible to a skilled person.

[0194] A first aspect of a first embodiment is a waterborne adhesive composition for the adhesive bonding of one or more substrates, wherein the waterborne adhesive composition comprises a waterborne dispersion comprising dispersed polymer particles comprising both (i) a polyurethane and (ii) a vinyl polymer, said dispersed particles comprising the polyurethane and the vinyl polymer in a weight ratio of the polyurethane to the vinyl polymer in the range from 25:75 to 90:10, and the polyurethane-vinyl polymer comprises a crystalline phase having a melting temperature in the range from 30 to 80 °C and an enthalpy of fusion of at least 10 J / g, whereby the melting temperature and the enthalpy of fusion are determined by differential scanning calorimetry according to DIN EN ISO 11357-1 :2017 (2017-02) at a heating rate of 20 K / min.

[0195] A second aspect of the first embodiment is the composition of the first aspect, wherein the adhesive bonding is effected after at least partial coagulation of the waterborne adhesive composition and while the at least partially coagulated waterborne adhesive composition is still in a wet state.

[0196] Another aspect of the first embodiment is the composition of the first or second aspect, wherein the adhesive bonding is effected at a temperature below the melting temperature of the polyurethane-vinyl polymer, preferably at ambient temperature.

[0197] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the polyurethane and the vinyl polymer are present in said dispersed particles in a weight ratio of the polyurethane to the vinyl polymer of at least 30:70, more preferably of at least 35:65, even more preferably of at least 40:60, most preferably higher than 50:50.

[0198] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the polyurethane and the vinyl polymer are present in the dispersed particles in a weight ratio of the polyurethane to the vinyl polymer of at most 90:10, preferably of at most 85:15, more preferably of at most 80:20. Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the polyurethane and the vinyl polymer are present in the dispersed particles in a weight ratio of the polyurethane to the vinyl polymer in the range from 30:70 to 85:15, more preferably in the range from 35:65 to 85:15, even more preferably in the range from 40:60 to 85:15, more preferably higher than 50:50 and lower than or equal to 80:20. Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the at least one vinyl polymer has a glass transition temperature Tgof at least -60 °C, more preferably of at least -50 °C, even more preferably of at least -40 °C, wherein the glass transition temperature is calculated using the Fox equation.

[0199] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the at least one vinyl polymer of the hybrid preferably has a calculated glass transition temperature Tgof at most 50 °C, more preferably of at most 45 °C, even more preferably of at most 40 °C, even more preferably of at most 35 °C, even more preferably of at most 30 °C, even more preferably of at most 25 °C, even more preferably of at most 20 °C, even more preferably of at most 15 °C, even more preferably of at most 10 °C, even more preferably of at most 5 °C, most preferably of at most 0 °C, wherein the glass transition temperature is calculated using the Fox equation.

[0200] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the vinyl polymer has a glass transition temperature Tgin the range from -60 to 50 °C, preferably in the range from -60 to 40 °C, even more preferably in the range from -60 to 35 °C, even more preferably in the range from -60 to 30°C, even more preferably in the range from -60 to 25°C, even more preferably in the range from -60 to 20°C, even more preferably in the range from -60 to 15°C, even more preferably in the range from -60 to 10°C, even more preferably in the range from -60 to 5 °C, even more preferably in the range from -60 to 0°C, wherein the glass transition temperature is calculated using the Fox equation.

[0201] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein at least 30 wt.%, more preferably at least 40 wt.%, more preferably at least 50 wt.%, even more preferably at least 60 wt.%, even more preferably at least 70 wt.% and even more preferably at least 80 wt.% of the total amount of vinyl monomer(s) used to prepare the at least one vinyl polymer is selected from the group consisting of methyl methacrylate, butyl acrylate, butyl methacrylate, ethyl hexyl acrylate, octyl acrylate (preferably 2-octyl acrylate), styrene and mixtures of two or more of said monomers.

[0202] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the at least one vinyl polymer preferably comprises less than 0.1 wt.% of acrylonitirile, more preferably the vinyl polymer does not comprise acrylonitrile. Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein said dispersed particles comprising the polyurethane and the vinyl polymer are obtained by free radical polymerization of at least one vinyl monomer in the presence of at least one water-dispersed polyurethane thereby obtaining a hybrid of polyurethane and vinyl polymer (polyurethane-vinyl polymer)).

[0203] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the polyurethane-vinyl polymer after drying is semicrystalline or crystalline and has a melting temperature of at least 35 °C, preferably of at least 40 °C, and of at most 80 °C, preferably of at most 70 °C, more preferably of at most 55 °C, even more preferably of at most 42 °C.

[0204] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the polyurethane-vinyl polymer has an enthalpy of fusion of at least 15 J / g, preferably of at least 17 J / g, more preferably of at least 18 J / g, most preferably of at least 19 J / g.

[0205] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the polyurethane-vinyl polymer has an enthalpy of fusion of at most 100 J / g, preferably of at most 90 J / g, more preferably of at most 80 J / g, more preferably of at most 70 J / g.

[0206] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the polyurethane is polyurethane-urea.

[0207] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the polyurethane is obtained by the reaction of at least the following components (A1)-(A3) and optionally (A4):

[0208] (A1) At least one polyisocyanate,

[0209] (A2) At least one isocyanate-reactive compound that contains at least one salt group which is capable to render the polyurethane dispersible in water and / or at least one functional group that can be converted into a salt group which is capable to render the polyurethane dispersible in water,

[0210] (A3) At least one isocyanate-reactive polyol other than (A2), and

[0211] (A4) Optionally at least one amino-functional isocyanate reactive compound other than (A2).

[0212] Another aspect of the first embodiment is the composition of the previous aspect of the first embodiment, wherein the polyurethane is the reaction product of: from 5 to 20 wt.%, preferably from 6.5 to 16 wt.%, more preferably from 8 to 13 wt.% of component (A1), from 0.5 to 3.5 wt.%, preferably from 0.6 to 2.5 wt.%, more preferably from 0.7 to 2.0 wt.% of component (A2), from 74.5 to 94.5 wt.%, preferably from 80.5 to 92.8 wt.%, more preferably from 84 to 91.2 wt.% of component (A3), and from 0 to 2 wt.%, preferably from 0.1 to 1 wt.% of component (A4), wherein the amounts of (A1), (A2), (A3) and (A4) add up to 100 wt.%.

[0213] Another aspect of the first embodiment is the composition of the previous aspect of the first embodiment, wherein (A3) comprises at least 50 wt.%, more preferably at least 60 wt.%, even more preferably at least 70 wt.%, even more preferably at least 80 wt.%, most preferably at least 90 wt.% of an aliphatic polyester polyol with a hydroxy value of at most 112 mg KOH / g, preferably of at most 75 mg KOH / g, more preferably of at most 64 mg KOH / g, most preferably of at most 56 mg KOH / g, wherein the aliphatic polyester polyol is preferably obtained from (i) succinic acid, methylsuccinic acid, glutaric acid, adipic acid and / or maleic acid, and (ii) propane-1, 3-diol, butane-1,4-diol, hexane-1,6-diol, epsilon- caprolactone and / or neopentyl glycol, more preferably the aliphatic polyester polyol is obtained from (i) adipic acid and (ii) butane-1 ,4-diol and / or hexane-1,6-diol, even more preferably the aliphatic polyester polyol is obtained from adipic acid and butane-1,4-diol.

[0214] Another aspect of the first embodiment is the composition of the previous aspect of the first embodiment, wherein the aliphatic polyester polyol is an aliphatic polyester diol.

[0215] Another aspect of the first embodiment is the composition of the two previous aspects of the first embodiment, wherein the at least one polyisocyanate according to (A1) comprises hexamethylene diisocyanate and / or toluene diisocyanate, more preferably component (A1) consists of 1,5-pentane diisocyanate (CAS number 4538-42-5), hexamethylene diisocyanate (CAS number 822-06-0), isophorone diisocyanate (CAS number 4098-71-9), dicyclohexylmethane-4,4’-diisocyanate H12MDI (CAS number 5124-30-1), 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4’-diphenylmethane diisocyanate (4,4’-MDI), or 2,4’-diphenylmethane diisocyanate or of any two or more thereof.

[0216] Another aspect of the first embodiment is the composition of any of the four previous aspects of the first embodiment, wherein component (A2) comprises or essentially consists of or consists of at least one diamine sulfonate salt, preferably component (A2) comprises or essentially consists of or consists of the sodium salt of 2-[(2- aminoethyl)amino]ethanesulfonic acid (CAS: 34730-59-1). Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the polyurethane-vinyl polymer comprises reacted hexamethylene diisocyanate and / or reacted 1 ,5-pentamethylene diisocyanate in an amount in the range from 1 to 15 wt.%, preferably in the range from 1 to 12 wt.%, more preferably in the range from 1 .5 to 10 wt.%, most preferably in the range from 2 to 8 wt.%, relative to the polyurethane- vinyl polymer.

[0217] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the polyurethane comprises reacted hexamethylene diisocyanate and / or reacted 1 ,5-pentane diisocyanate in an amount of in the range from 3 to 19 wt.%, more preferably in the range from 4 to 15 wt.%, more preferably in the range from 4.5 to 13 wt.%, most preferably in the range from 5 to 10 wt.%, whereby the amount of reacted hexamethylene diisocyanate and / or reacted 1 ,5-pentane diisocyanate is the amount of hexamethylene diisocyanate and 1 ,5-pentane diisocyanate used to prepare the polyurethane relative to the total amounts of components used to prepare the polyurethane from which the building blocks from the polyurethane are emanated.

[0218] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the polyurethane-vinyl polymer comprises reacted hexamethylene diisocyanate and / or reacted 1 ,5-pentane diisocyanate in an amount of from 1 to 15 wt.%, preferably from 1 to 12 wt.%, more preferably from 1.5 to 10 wt.%, more preferably from 1.8 to 8 wt.%, most preferably from 2 to 5 wt.%, relative to the total amounts of components used to prepare the polyurethane-vinyl polymer from which the building blocks from the polyurethane-vinyl polymer are emanated.

[0219] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the polyurethane comprises reacted hexamethylene diisocyanate and reacted isophorone diisocyanate in such an amount that the weight ratio of hexamethylene diisocyanate to isophorone diisocyanate used to prepare the polyurethane is in the range from 0.25 to 20, more preferably in the range from 0.5 to 10, more preferably in the range from 1 to 5, more preferably in the range from 1.1 to 3, most preferably in the range from 1.2 to 2.

[0220] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the polyurethane-vinyl polymer has a hydroxy value in the range from 0.5 to 20 mg KOH / g, more preferably in the range from 1 to 12 mg KOH / g, even more preferably in the range from 1.5 to 10 mg KOH / g, even more preferably in the range from 2 to 7 mg KOH / g, most preferably in the range from 2 to 5 mg KOH / g.

[0221] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the polyurethane-vinyl polymer has an acid value in the range from 0.6 to 20 mg KOH / g, more preferably in the range from 0.6 to 10 mg KOH / g, even more preferably in the range from 0.7 to 7 mg KOH / g, even more preferably in the range from 0.7 to 4 mg KOH / g, most preferably in the range from 0.8 to 3 mg KOH / g, especially preferred in the range from 0.8 to 2.7 mg KOH / g.

[0222] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the dispersed particles have z-average particle size in the range from 30 to 600 nm, more preferably in the range from 50 to 400 nm, even more preferably in the range from 70 to 350 nm, most preferably in the range from 110 to 275 nm, wherein the z- average particle size is determined with the method as described further herein.

[0223] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the polyurethane is obtained by the reaction of at least the following components (A1)-(A3) and optionally (A4):

[0224] (A1) At least one polyisocyanate,

[0225] (A2) At least one isocyanate-reactive compound that contains at least one salt group which is capable to render the polyurethane dispersible in water and / or at least one functional group that can be converted into a salt group which is capable to render the polyurethane dispersible in water,

[0226] (A3) At least one isocyanate-reactive polyol other than (A2), and

[0227] (A4) Optionally at least one amino-functional isocyanate reactive compound other than (A2); component A3 comprises at least 50 wt.% of an aliphatic polyester polyol with a hydroxy value of at most 112 mg KOH / g that is preferably obtained from (i) succinic acid, methylsuccinic acid, glutaric acid, adipic acid and / or maleic acid, and (ii) propane-1, 3-diol, butane-1,4-diol, hexane-1,6-diol, epsilon-caprolactone and / or neopentyl glycol; the polyurethane-vinyl polymer comprises from 1 to 15 wt.% of reacted hexamethylene diisocyanate and / or reacted 1,5-pentane diisocyanate, whereby the amount of reacted hexamethylene diisocyanate and / or reacted 1 ,5-pentane diisocyanate is given relative to the total amount of components used to prepare the polyurethane-vinyl polymer from which the building blocks from the polyurethane-vinyl polymer are emanated; the acid value of the polyurethane-vinyl polymer is in the range from 0.6 to 20 mg KOH / g; and the polyurethane-vinyl polymer particles have a z-average particle size in the range from 30 to 600 nm.

[0228] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the dispersed particles have a polydispersity (Mw / Mn) in the range from

[0229] 9 to 50, preferably in the range from 10 to 40, more preferably in the range from 10 to 35, wherein the polydispersity is determined with the method according to the description.

[0230] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the waterborne adhesive composition optionally comprises plasticizer in an amount of less than 15 wt.%, preferably less than 12 wt.%, more preferably less than

[0231] 10 wt.%, more preferably less than 8 wt.%, more preferably less than 5 wt.%, more preferably less than 2 wt.%, more preferably less than 1 wt.%, more preferably less than 0.5 wt.%, more preferably less than 0.1 wt.%, relative to the solids content of the waterborne adhesive composition, most preferably the waterborne adhesive composition is free of plasticizer.

[0232] Another aspect of the first embodiment is the composition of the previous aspect of the first embodiment, wherein the plasticizer, if present, is at least one non-volatile, low molecular weight compound bearing polar group(s), preferably the plasticizer, if present, is at least one compound selected from the group consisting of di(phenoxyethyl)formal, dialkyl adipate, dialkyl terephthalate, dialkyl phthalate, dialkyl succinate, alkylsulfonic ester of phenol and esters based on benzoic acid, preferably dibenzoate, more preferably dipropylene glycol dibenzoate.

[0233] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the waterborne adhesive composition optionally comprises tackifier resin in an amount of less than 10 wt.%, relative to the solids content of the waterborne adhesive composition.

[0234] Another aspect of the first embodiment is the composition of the previous aspect of the first embodiment, wherein the tackifier resin, if present, is made of rosins or of modified rosins, preferably is one or more rosin esters.

[0235] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the waterborne adhesive composition has a solids content of at least 15 wt.%, more preferably of at least 20 wt.%, more preferably of at least 25 wt.%, more preferably of at least 30 wt.%, more preferably of at least 35 wt.%, more preferably of at least 40 wt.%, most preferably of at least 45 wt.% and preferably of at most 70 wt.%, more preferably of at most 65 wt.%, even more preferably of at most 60 wt.% or of at most 55 wt.%.

[0236] Another aspect of the first embodiment is the composition of any of the aspects of the first embodiment, wherein the polyurethane and the vinyl polymer are present in the waterborne adhesive composition in a total amount in the range from 65 to 100 wt.%, preferably in the range from 70 to 100 wt.%, more preferably in the range from 75 to 100 wt.%, more preferably in the range from 80 to 100 wt.%, more preferably in the range from 85 to 100 wt.%, more preferably in the range from 90 to 100 wt.%, more preferably in the range from 95 to 100 wt.%, relative to the solids content of the waterborne adhesive composition.

[0237] A second embodiment is a one-component adhesive composition for the adhesive bonding of one or more substrates, wherein the one-component adhesive composition comprises the waterborne adhesive composition according to any one of the aspects of the first embodiment and optionally a destabilizer for the dispersion.

[0238] A third embodiment is a two-component adhesive composition for the adhesive bonding of one or more substrates, wherein the two-component adhesive composition consists of a first component and a second component, wherein the first component comprises, consists essentially of, or consists of the waterborne adhesive composition according to any one of the aspects of the first embodiment; and the second component comprises a coagulant.

[0239] A first aspect of a fourth embodiment is the use of the waterborne adhesive composition according to any one of the aspects of the first, second or third embodiment for the adhesive bonding of one or more substrates after at least partial coagulation of the waterborne adhesive composition and while the at least partially coagulated waterborne adhesive composition is still in a wet state, wherein the waterborne adhesive composition is preferably applied to at least a part of at least one of the surfaces of the substrate or of the substrates to be adhesively bonded by rolling, brushing or spraying, more preferably by rolling or spray coagulating, in particular preferably by spray coagulating.

[0240] Another aspect of the fourth embodiment is the use of the first aspect of the fourth embodiment, wherein a two-component adhesive is used in a spray coagulating process and wherein one of the components of the two-component adhesive is the waterborne adhesive composition according to any one of aspects of the first embodiment.

[0241] Another aspect of the fourth embodiment is the use of the first aspect of the fourth embodiment, wherein a one-component adhesive is used in a spray coagulating process and wherein the one-component adhesive comprises the waterborne adhesive composition according to any one of aspects of the first embodiment.

[0242] Another aspect of the fourth embodiment is the use of any of the aspects of the fourth embodiment for adhesively bonding foams in mattress, furniture and / or upholstery manufacturing.

[0243] A first aspect of a fifth embodiment is a process for adhesive bonding of one or more substrates, wherein the process comprises applying an adhesive composition according to any one of the aspects of the first, second or third embodiment on at least a part of at least one of the surfaces of the substrate or of the substrates to be adhesively bonded and bonding then takes place at a temperature below the melting temperature of the polyurethane-vinyl polymer, preferably at ambient temperature.

[0244] Another aspect of the fifth embodiment is the process of the previous aspect of the fifth embodiment for adhesively bonding of foam in mattress, furniture and / or upholstery manufacturing.

[0245] Another aspect of the fifth embodiment is the process of any of the previous aspects of the fifth embodiment for adhesive bonding of one or more substrates comprising

[0246] 1) applying to and coagulating a waterborne adhesive composition according to any of the aspects of the first embodiment on at least a part of at least one of the surfaces of the substrate or of the substrates to be adhesively bonded to obtain an at least partially coagulated adhesive film in a still wet state that is ready for bonding,

[0247] 2) disposing the surfaces one on the other,

[0248] 3) optionally contact pressing them together at a temperature below the melting temperature of the polyurethane-vinyl polymer, preferably at ambient temperature, and

[0249] 4) drying the adhesive film to constant weight to obtain a dried adhesive film. Another aspect of the fifth embodiment is the process of any of the previous aspects of the fifth embodiment for adhesive bonding of one or more substrates comprising

[0250] - spray coagulating the waterborne adhesive composition according to any of the aspects of the first embodiment in a spray jet onto on at least a part of at least one of the surfaces of the substrate or of the substrates to be adhesively bonded to obtain an adhesive film,

[0251] - disposing the surfaces one on the other,

[0252] - optionally contact pressing them together at a temperature below the melting temperature of the polyurethane-vinyl polymer, preferably at ambient temperature, and

[0253] - drying the adhesive film to constant weight to obtain a dried adhesive film.

[0254] Another aspect of the fifth embodiment is the process of the previous aspect of the fifth embodiment, wherein the process comprises a) conveying the waterborne adhesive composition according to any of the aspects of the first embodiment and a coagulant separately into a spray gun, b) mixing the waterborne adhesive composition and the coagulant in a spray jet, b) coagulating the waterborne adhesive composition in the spray jet (on the path to the surface of the substrate) to obtain an at least partially coagulated composition, c) spraying the at least partially coagulated composition onto at least a part of at least one of the surfaces of the substrate or of the substrates to be adhesively bonded to obtain an adhesive film, d) disposing the surfaces one on the other, e) optionally contact pressing them together at a temperature below the melting temperature of the polyurethane-vinyl polymer, preferably at ambient temperature, and f) drying the adhesive film to constant weight to obtain a dried adhesive film.

[0255] Another aspect of the fifth embodiment is the process of the previous aspect of the fifth embodiment, wherein the process is carried out at a temperature below the melting temperature of the polyurethane-vinyl polymer, preferably at ambient temperature.

[0256] A first aspect of a sixth embodiment are one or more substrates adhesively bonded with the adhesive composition of any of the aspects of the first, second or third embodiment wherein the substrate(s) are composed of foam, wood, paper, leather, textiles, cork or plastics.

[0257] Another aspect of the sixth embodiment are the one or more substrates of the previous aspect of the sixth embodiment, wherein the substrates comprise a first substrate that is foam or textile, adhesively bonded to a second substrate that is foam, wood or plastic. Another aspect of the sixth embodiment are the one or more substrates of the previous aspect of the sixth embodiment, wherein at least one of the first or the second substrate is a foam substrate.

[0258] Another aspect of the sixth embodiment are the one or more substrates of any of the two previous aspects of the sixth embodiment, wherein the first substrate is polyurethane foam or foam rubber.

[0259] A seventh embodiment is a process for adhesive bonding of one or more substrates comprising

[0260] 1) rolling the waterborne adhesive composition according to any of the aspects of the first embodiment or rolling the one-component adhesive composition according to the second embodiment or rolling the two-component adhesive composition according to the third embodiment on at least a part of at least one of the surfaces of the substrate or of the substrates to be adhesively bonded to obtain an at least partially coagulated adhesive film in a still wet state that is ready for bonding,

[0261] 2) disposing the surfaces one on the other,

[0262] 3) optionally contact pressing them together at a temperature below the melting temperature of the polyurethane-vinyl polymer, preferably at ambient temperature, and

[0263] 4) drying the adhesive film to constant weight to obtain a dried adhesive film. A first aspect of an eight embodiment is the process for adhesive bonding of one or more substrates comprising

[0264] - spray coagulating the waterborne adhesive composition according to any of the aspects of the first embodiment in a spray jet onto on at least a part of at least one of the surfaces of the substrate or of the substrates to be adhesively bonded to obtain an adhesive film,

[0265] - disposing the surfaces one on the other,

[0266] - optionally contact pressing them together at a temperature below the melting temperature of the polyurethane-vinyl polymer, preferably at ambient temperature, and

[0267] - drying the adhesive film to constant weight to obtain a dried adhesive film.

[0268] Another aspect of the eight embodiment is the process of the previous aspect of the eight embodiment, wherein the process comprises a) conveying the waterborne adhesive composition according to any of the aspects of the first embodiment and a coagulant separately into a spray gun, b) mixing the waterborne adhesive composition and the coagulant in a spray jet, b) coagulating the waterborne adhesive composition in the spray jet (on the path to the surface of the substrate) to obtain an at least partially coagulated composition, c) spraying the at least partially coagulated composition onto at least a part of at least one of the surfaces of the substrate or of the substrates to be adhesively bonded to obtain an adhesive film, d) disposing the surfaces one on the other, e) optionally contact pressing them together at a temperature below the melting temperature of the polyurethane-vinyl polymer, preferably at ambient temperature, and f) drying the adhesive film to constant weight to obtain a dried adhesive

Claims

Claims1. Use of a waterborne adhesive composition for the adhesive bonding of one or more substrates after at least partial coagulation of the waterborne adhesive composition and while the at least partially coagulated waterborne adhesive composition is still in a wet state, wherein the waterborne adhesive composition comprises a waterborne dispersion comprising dispersed polymer particles comprising both (i) a polyurethane and (ii) a vinyl polymer, said dispersed particles comprising the polyurethane and the vinyl polymer in a weight ratio of the polyurethane to the vinyl polymer in the range from 25:75 to 90:10, and the polyurethane-vinyl polymer comprises a crystalline phase having a melting temperature in the range from 30 to 80 °C and an enthalpy of fusion of at least 10 J / g, whereby the melting temperature and the enthalpy of fusion are determined by differential scanning calorimetry according to DIN EN ISO 11357-1 :2017 (2017-02) at a heating rate of 20 K / min, and wherein the adhesive bonding is effected at a temperature below the melting temperature of the polyurethane-vinyl polymer.

2. Use according to claim 1 , wherein the polyurethane and the vinyl polymer are present in said dispersed particles in a weight ratio of the polyurethane to the vinyl polymer in the range from 30:70 to 85:15, more preferably in the range from 35:65 to 85:15, even more preferably in the range of in the range from 40:60 to 85:15, more preferably higher than 50:50 and lower than or equal to 80:20.

3. Use according to claim 1 or 2, wherein the vinyl polymer has a glass transition temperature Tgof at least -60 °C and of at most 50 °C, preferably at most 40 °C, more preferably at most 35 °C, even more preferably at most 30°C, even more preferably at most 25°C, even more preferably at most 20°C, even more preferably at most 15°C, even more preferably at most 10°C, even more preferably at most 5 °C, even more preferably at most 0°C, wherein the glass transition temperature is calculated using the Fox equation.

4. Use according to any one of the preceding claims, wherein said dispersed particles comprising the polyurethane and the vinyl polymer are obtained by free radical polymerization of at least one vinyl monomer in the presence of at least one water- dispersed polyurethane thereby obtaining a hybrid of polyurethane and vinyl polymer (polyurethane-vinyl polymer).

5. Use according to any one of the preceding claims, wherein the polyurethane-vinyl polymer after drying is semicrystalline or crystalline and has a melting temperature in the range from 35 to 80 °C, more preferably in the range from 40 to 70 °C, even more preferably in the range from 40 to 55 °C and / or an enthalpy of fusion of at least 15 J / g, more preferably at least 17 J / g, more preferably of at least 19 J / g.

6. Use according to any one of the preceding claims, wherein the polyurethane is obtained by the reaction of at least the following components (A1)-(A3) and optionally (A4):(A1) At least one polyisocyanate,(A2) At least one isocyanate-reactive compound that contains at least one salt group which is capable to render the polyurethane dispersible in water and / or at least one functional group that can be converted into a salt group which is capable to render the polyurethane dispersible in water,(A3) At least one isocyanate-reactive polyol other than (A2), and (A4) Optionally at least one amino-functional isocyanate reactive compound other than (A2), wherein the polyurethane is preferably the reaction product of: from 5 to 20 wt.%, preferably from 6.5 to 16 wt.%, more preferably from 8 to 13 wt.% of component (A1), from 0.5 to 3.5 wt.%, preferably from 0.6 to 2.5 wt.%, more preferably from 0.7 to 2.0 wt.% of component (A2), from 74.5 to 94.5 wt.%, preferably from 80.5 to 92.8 wt.%, more preferably from 84 to 91.2 wt.% of component (A3), and from 0 to 2 wt.%, preferably from 0.1 to 1 wt.% of component (A4), wherein the amounts of (A1), (A2), (A3) and (A4) add up to 100 wt.%.

7. Use according to any one of the preceding claims, wherein less than 0.1 wt.% of the total amount of the vinyl monomer(s) used to prepare the vinyl polymer is acrylonitirile, more preferably the vinyl monomer(s) used to prepare the vinyl polymer does not comprise acrylonitrile.

8. Use according to any one of preceding claims, wherein the waterborne adhesive composition optionally comprises plasticizer in an amount of less than 15 wt.%, preferably less than 12 wt.%, more preferably less than 10 wt.%, more preferably less than 8 wt.%, more preferably less than 5 wt.%, more preferably less than 2 wt.%, more preferably less than 1 wt.%, more preferably less than 0.5 wt.%, more preferably less than 0.1 wt.%, relative to the solids content of the waterborne adhesive composition, most preferably the waterborne adhesive composition is free of plasticizer.

9. Use according to any one of the preceding claims, wherein the polyurethane and the vinyl polymer are present in the waterborne adhesive composition in a total amount in the range from 65 to 100 wt.%, preferably in the range from 70 to 100 wt.%, more preferably in the range from 75 to 100 wt.%, more preferably in the range from 80 to 100 wt.%, more preferably in the range from 85 to 100 wt.%, more preferably in the range from 90 to 100 wt.%, more preferably in the range from 95 to 100 wt.%, relative to the solids content of the waterborne adhesive composition.

10. Use according to any one of the preceding claims, wherein the adhesive bonding is effected at ambient temperature.

11. A one-component adhesive composition for the adhesive bonding of one or more substrates, wherein the one-component adhesive composition comprises the waterborne adhesive composition as defined in any one of claims 1 to 9 and optionally a compound that reduces the coagulation stability of the adhesive composition.

12. A two-component adhesive composition for the adhesive bonding of one or more substrates, wherein the two-component adhesive composition consists of a first component and a second component, wherein the first component comprises, consists essentially of, or consists of the waterborne adhesive composition as defined in any one of claims 1 to 9; and the second component comprises a coagulant.13 Use of the adhesive composition as defined in any one of claims 1 to 9 or according to claim 11 or 12 in a spray coagulation process or in a rolling process.

14. Use according to claim 13 for adhesively bonding foams in mattress, furniture and / or upholstery manufacturing.

15. A process for adhesive bonding of one or more substrates, wherein the process comprises(i) applying an adhesive composition as defined in any one of claims 1 to 9 or as claimed in claim 11 or 12 on at least a part of at least one of the surfaces of the substrate or of the substrates to be adhesively bonded, and(ii) bonding at a temperature below the melting temperature of the polyurethane- vinyl polymer, preferably at ambient temperature.

16. The process according to claim 15, wherein the process comprises(i) rolling or spray coagulating an adhesive composition as defined in any one of claims 1 to 9 or as claimed in claim 11 or 12 on at least a part of at least one of the surfaces of the substrate or of the substrates to be adhesively bonded, and(ii) bonding at a temperature below the melting temperature of the polyurethane- vinyl polymer, preferably at ambient temperature.

17. The process according to claim 15 or 16, wherein the process comprises1) applying to and coagulating a waterborne adhesive composition as defined in any one of claims 1 to 9 or as claimed in claim 11 or 12 on at least a part of at least one of the surfaces of the substrate or of the substrates to be adhesively bonded to obtain an at least partially coagulated adhesive film in a still wet state that is ready for bonding,2) disposing the surfaces one on the other,3) optionally contact pressing them together at a temperature below the melting temperature of the polyurethane-vinyl polymer, preferably at ambient temperature, and4) drying the adhesive film to constant weight to obtain a dried adhesive film.

18. The process according to any one of claims 15 to 17 for adhesively bonding of foam in mattress, furniture and / or upholstery manufacturing.

19. An article comprising surfaces bonded with an adhesive layer obtained from the process according to any one of claims 15 to 18, wherein the article is a mattress or a furniture part.

Images