Waterborne polyurethane dispersion

Abstract

The present invention relates to an aqueous polyurethane dispersion and a preparation method thereof, an adhesive containing the same, and an adhesive product obtained by adhesive bonding. The aqueous polyurethane dispersion comprises a polyurethane having an anionic group dispersed therein, wherein the polyurethane has a melting enthalpy of 3 J / g-100 J / g at 20°C-100°C measured by DSC according to DIN 65467 for the first heating curve, and a weight average molecular weight of 31000-95000, and the acid value of the aqueous polyurethane dispersion is 0.5 mgKOH / g-8.5 mgKOH / g. The adhesive containing the aqueous polyurethane dispersion of the present invention has excellent initial bonding force.

Description

Technical Field

[0001] The invention relates to an aqueous polyurethane dispersion and a preparation method thereof, an adhesive containing the aqueous polyurethane dispersion, and an adhesive product obtained by bonding the aqueous polyurethane dispersion with the adhesive. Background Art

[0002] Waterborne polyurethane dispersions can be widely used in coatings, adhesives, sealants and printing inks.

[0003] US2015 / 0037555A1 discloses a self-supporting adhesive film, comprising a solid surface-passivating isocyanate and more than 70% by weight of a first polyurethane, wherein the first polyurethane has a weight average molecular weight of not more than about 90,000 and a melting enthalpy of at least about 25 J / g. The first polyurethane is obtained by reacting a mixture containing a polyester polyol and an aliphatic isocyanate.

[0004] US2013 / 0236719A1 discloses a method for covering a substrate with a multilayer decorative film in a thermoforming method, preferably in a vacuum forming method, characterized in that the method comprises the following steps: (i) providing a multilayer decorative film comprising a hard coating layer (A), a bonding layer (D), a substrate film layer and an optional design layer located between these layers (A) and (D), wherein the bonding layer (D) comprises at least one latent reactive adhesive, (ii) applying the bonding layer (D) of the decorative film to the surface of the substrate, (iii) covering the substrate with the decorative film by heating at 70°C or higher. The adhesive comprises an aqueous dispersion obtained by reacting a mixture comprising a polyisocyanate and an isocyanate-reactive compound and dispersing it in water. The isocyanate-reactive compound is crystalline or semi-crystalline and has a weight average molecular weight of 20,000-250,000.

[0005] US2016 / 0168434A1 discloses an aqueous adhesive composition, which contains: a surface-passivated solid isocyanate, a first polyurethane dispersion, and a second polyurethane dispersion. The first polyurethane dispersion contains functional groups reactive with isocyanate and can be obtained by reacting a mixture of a crystalline polymer polyol and an aliphatic polyisocyanate. The first polyurethane has a weight average molecular weight of not less than about 50,000 and not more than about 125,000.

[0006] US2015 / 0034314A1 discloses a coating coated with a coating containing a crystalline or semi-crystalline polyurethane, wherein the weight average molecular weight of the polyurethane is 20000-250000. The polyurethane is obtained by reacting a mixture containing a diisocyanate or polyisocyanate, a polyester polyol and a compound containing a sulfonate group and / or a carboxylate group, wherein the diisocyanate or polyisocyanate is an aliphatic and / or alicyclic diisocyanate.

[0007] US2012 / 0225302A1 discloses an aqueous composition comprising (a) at least one crystalline or semi-crystalline polyurethane having a weight-average molecular weight of 20,000-250,000, (b) at least one polyisocyanate having aliphatically bonded isocyanate groups which is liquid at a temperature of 20°C to 25°C, (c) at least one compound of one or more elements of groups V and VIB of the periodic table, wherein the elements have a degree of oxidation of at least +4, and (d) optionally other auxiliary substances and additives.

[0008] EP1512705A1 discloses an aqueous polyurethane dispersion containing side chain carboxyl groups, wherein the polyurethane contained therein is obtained by reacting a mixture containing polyester polyol and isophorone diisocyanate, and the weight average molecular weight of the polyurethane is 1000-100000.

[0009] US2013 / 0220543A1 discloses a method for manufacturing a coated article, comprising the steps of: (I) providing a substrate; (II) applying a first polyurethane and / or polyurethane-polyurea polymer to the substrate, the first polyurethane and / or polyurethane-polyurea polymer being capable of reaching an at least partially crystalline state having a final crystallinity, and wherein the first polyurethane and / or polyurethane-polyurea polymer is present in a non-crystalline state during and / or after the application. The method further comprises the steps of: (III) applying a composition comprising a mixture of a second polyurethane and / or polyurethane-polyurea polymer and an additional acrylate polymer to the first polyurethane and / or polyurethane-polyurea polymer of step (II), wherein the application is carried out when the crystallinity of the first polyurethane-polyurea polymer is lower than its final crystallinity; and (IV) cooling the obtained article to a temperature below the glass transition temperature of the acrylate polymer. The weight average molecular weight of the second polyurethane and / or polyurethane-polyurea polymer is 15,000-150,000.

[0010] DE102015213353A1 discloses an aqueous polyurethane dispersion, wherein the polyurethane contained therein is obtained by reacting a mixture containing semi-crystalline polyester polyol, aliphatic diisocyanate and sulfonated diol. The weight average molecular weight of the polyurethane is 15000-25000.

[0011] The above-mentioned water-based polyurethane dispersion cannot be applied to adhesives that require initial adhesion. Therefore, the industry, especially the shoe glue industry, hopes to develop a new water-based polyurethane dispersion that can be applied to the adhesive field to achieve excellent initial adhesion. Summary of the invention

[0012] The object of the present invention is to provide an aqueous polyurethane dispersion and a preparation method thereof, an adhesive containing the aqueous polyurethane dispersion, and an adhesive product obtained by bonding the aqueous polyurethane dispersion.

[0013] The aqueous polyurethane dispersion according to the present invention comprises a polyurethane having an anionic group dispersed therein, wherein the polyurethane has a melting enthalpy of 3 J / g-100 J / g at 20° C.-100° C. measured by DSC according to DIN 65467, a weight average molecular weight of 31000-95000, and an acid value of 0.5 mgKOH / g-8.5 mgKOH / g.

[0014] According to one aspect of the present invention, there is provided a method for preparing an aqueous polyurethane dispersion provided by the present invention, comprising the following steps:

[0015] i. reacting some or all of the polyisocyanate mixture and the mixture containing isocyanate-reactive groups to obtain a prepolymer, the reaction being carried out in the presence of an optional solvent or an optional solvent is added after the reaction to dissolve the prepolymer;

[0016] ii. reacting the prepolymer, an emulsifier, an optional reactive diluent, an optional stabilizer, a polyisocyanate mixture not added in step i, and a mixture containing isocyanate-reactive groups not added in step i to obtain the polyurethane; and

[0017] iii. before, during or after step ii, water and optionally an emulsifier are introduced to obtain the aqueous polyurethane dispersion;

[0018] The aqueous polyurethane dispersion contains a polyurethane having an anionic group dispersed therein, wherein the polyurethane has a melting enthalpy of 3 J / g to 100 J / g at 20° C. to 100° C. measured by DSC according to DIN 65467, a weight average molecular weight of 31000 to 95000, and an acid value of 0.5 mgKOH / g to 8.5 mgKOH / g.

[0019] According to another aspect of the present invention, a composition comprising the aqueous polyurethane dispersion provided by the present invention is provided.

[0020] According to another aspect of the present invention, an adhesive comprising the aqueous polyurethane dispersion provided by the present invention is provided.

[0021] According to another aspect of the present invention, there is provided a bonded product comprising substrates bonded with the adhesive provided according to the present invention.

[0022] According to another aspect of the present invention, there is provided a method for manufacturing an adhesive product, comprising the following steps:

[0023] A. applying the adhesive provided by the present invention to at least one surface of a substrate;

[0024] B. heating and drying the substrate surface to which the adhesive is applied; and

[0025] C. contacting the surface of the substrate treated in step B with the surface of the substrate itself or another substrate to obtain the bonded article.

[0026] According to another aspect of the present invention, there is provided use of the aqueous polyurethane dispersion provided by the present invention in the production of adhesive products.

[0027] The aqueous polyurethane dispersion of the present invention has a certain acid value, and the polyurethane contained therein has a certain melting enthalpy and weight average molecular weight. The adhesive containing the aqueous polyurethane dispersion of the present invention has excellent initial bonding force. DETAILED DESCRIPTION

[0028] The present invention provides an aqueous polyurethane dispersion, comprising polyurethane with anionic groups dispersed therein, wherein the polyurethane has a melting enthalpy of 3 J / g-100 J / g at 20°C-100°C measured by DSC according to DIN 65467, a weight average molecular weight of 31000-95000, and an acid value of 0.5 mgKOH / g-8.5 mgKOH / g. The present invention also provides a method for preparing the aqueous polyurethane dispersion, an adhesive comprising the aqueous polyurethane dispersion, and an adhesive product obtained by bonding the adhesive.

[0029] The aqueous polyurethane dispersion of the present invention includes an aqueous polyurethaneurea dispersion, an aqueous polyurethane-polyurea dispersion and / or an aqueous polyurea dispersion.

[0030] The sulfonate group of the present invention refers to -SO3 - .

[0031] The carboxylate group of the present invention refers to -COO - .

[0032] The carboxyl group of the present invention refers to -COOH.

[0033] Waterborne polyurethane dispersion

[0034] The melting enthalpy of the polyurethane at 20° C. to 100° C. measured by DSC according to DIN 65467 is preferably 25 J / g to 100 J / g, most preferably 30 J / g to 80 J / g.

[0035] The polyurethane contains carboxyl groups, and the carboxyl group content of the polyurethane is preferably 0.1 wt % to 1.5 wt %, based on 100 wt % of the polyurethane.

[0036] The anionic groups are preferably located in the side chains of the polyurethane.

[0037] The anionic group is preferably one or more of the following: a sulfonate group and a carboxylate group.

[0038] The number average molecular weight of the polyurethane is preferably 1000 g / mol-10000 g / mol.

[0039] The aqueous polyurethane dispersion comprises water.

[0040] The solid content of the aqueous polyurethane dispersion is preferably 20-70% by weight, more preferably 30-65% by weight, and most preferably 35-60% by weight, based on 100% by weight of the aqueous polyurethane dispersion.

[0041] The polyurethane is preferably obtained by reacting a system comprising the following components:

[0042] a. a polyisocyanate mixture containing hexamethylene diisocyanate;

[0043] b a mixture containing isocyanate-reactive groups, the mixture containing isocyanate-reactive groups comprising a number average molecular weight of 400g / mol-8000g / mol of a polymer polyol and a carboxyl group-containing isocyanate-reactive compound;

[0044] c. an emulsifier;

[0045] d. an optional solvent;

[0046] e. optionally a reactive diluent; and

[0047] f. an optional stabilizer;

[0048] The melting enthalpy of the polymer polyol at 20°C-100°C measured by DSC according to DIN 65467 is 3 J / g-100 J / g, the amount of the isocyanate-reactive compound containing a carboxyl group is 0.1 wt%-1.5 wt%, based on 100 wt% of the polyurethane, and the degree of neutralization of the carboxyl group of the isocyanate-reactive compound containing a carboxyl group is 0-50%.

[0049] Polyisocyanate mixture

[0050] The isocyanate functionality of the polyisocyanate mixture is preferably 2-4, most preferably 2.

[0051] The amount of the polyisocyanate mixture is preferably 5% to 70% by weight, more preferably 5% to 40% by weight, further preferably 5% to 35% by weight, most preferably 10% to 30% by weight, based on 100% by weight of the system.

[0052] The amount of the hexamethylene diisocyanate is preferably 0.01% by weight to 100% by weight, based on 100% by weight of the polyisocyanate mixture.

[0053] The polyisocyanate mixture may further comprise an isocyanate different from the hexamethylene diisocyanate.

[0054] The isocyanate different from the hexamethylene diisocyanate is preferably one or more of the following: aliphatic isocyanates, alicyclic isocyanates, aromatic isocyanates, and their derivatives having iminooxadiazinedione, isocyanurate, uretdione, carbamate, allophanate, biuret, urea, oxadiazinetriaone, oxazolidinone, acylurea and / or carbodiimide groups.

[0055] The aliphatic isocyanate is preferably one or more of the following: 2,2-dimethylpentane diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, butylene diisocyanate, 1,3-butadiene-1,4-diisocyanate, 2,4,4-trimethyl 1,6-hexamethylene diisocyanate, 1,6,11-undecane triisocyanate, 1,3,6-hexamethylene triisocyanate, 1,8-diisocyanato-4-isocyanate bis(isocyanatoethyl)carbonate, bis(isocyanatoethyl)ether, lysine methyl diisocyanate, lysine triisocyanate, bis(isocyanatomethyl)sulfide, bis(isocyanatoethyl)sulfide, bis(isocyanatopropyl)sulfide, bis(isocyanatohexyl)sulfide, bis(isocyanatomethyl)sulfone, bis(isocyanatomethyl)disulfide, bis(isocyanatoethyl)disulfide, bis(isocyanatopropyl)sulfide 1,2,3-Tris(isocyanatomethylthio)propane, 1,2,3-tris(isocyanatoethylthio)propane, 3,5-dithia-1,2,6, 7-heptane tetraisocyanate, 2,6-diisocyanatomethyl-3,5-dithia-1,7-heptane diisocyanate, 2,5-diisocyanatomethylthiophene, isocyanatoethylthio-2,6-dithia-1,8-octane diisocyanate, thiobis(3-isothiocyanatopropane), thiobis(2-isothiocyanatoethane), dithiobis(2-isothiocyanatoethane), and isophorone diisocyanate.

[0056] The alicyclic isocyanate is preferably one or more of the following: 2,5-bis(isocyanatomethyl)-bicyclo[2.2.1]heptane, 2,6-bis(isocyanatomethyl)-bicyclo[2.2.1]heptane, bis(isocyanatomethyl)cyclohexane, isophorone diisocyanate, 2,5-diisocyanatotetrahydrothiophene, 2,5-diisocyanatomethyltetrahydrothiophene, 3,4-diisocyanatomethyltetrahydrothiophene, 2,5-diisocyanato-1,4-dithiane, 2,5-diisocyanatomethyl-1,4-dithiane, 4,5-diisocyanatomethyl-1,4-dithiane, Ester-1,3-dithiolane, 4,5-bis(isocyanatomethyl)-1,3-dithiolane, 4,5-diisocyanatomethyl-2-methyl-1,3-dithiolane, norbornane diisocyanate (NBDI), xylylene diisocyanate (XDI), hydrogenated xylylene diisocyanate (H6XDI), 1,4-cyclohexyl diisocyanate (H6PPDI), 1,5-pentane diisocyanate (PDI), m-tetramethylxylene diisocyanate (m-TMXDI) and cyclohexane diisothiocyanate.

[0057] The aromatic isocyanate is preferably one or more of the following: 1,2-diisocyanate benzene, 1,3-diisocyanate benzene, 1,4-diisocyanate benzene, 2,4-diisocyanate toluene, ethylphenyl diisocyanate, isopropylphenyl diisocyanate, toluene diisocyanate, diethylphenyl diisocyanate, diisopropylphenyl diisocyanate, trimethylbenzene triisocyanate, benzene triisocyanate, biphenyl diisocyanate, toluidine diisocyanate, 4,4'-methylenebis(phenyl isocyanate), 4,4'-methylenebis(2-methylphenyl isocyanate), bibenzyl-4,4'-diisocyanate Isocyanate, bis(isocyanatophenyl)ethylene, bis(isocyanatomethyl)benzene, bis(isocyanatoethyl)benzene, bis(isocyanatopropyl)benzene, α,α,α',α'-tetramethylxylene diisocyanate, bis(isocyanatobutyl)benzene, bis(isocyanatomethyl)naphthalene, bis(isocyanatomethylphenyl)ether, bis(isocyanatoethyl)phthalate, 2,6-bis(isocyanatomethyl)furan, 2-isocyanatophenyl-4-isocyanatophenyl sulfide, bis(4-isocyanatophenyl)sulfide, bis(4-isocyanatomethylphenyl)sulfide, bis(4-isocyanatophenyl) bis(2-methyl-5-isocyanatophenyl) disulfide, bis(3-methyl-5-isocyanatophenyl) disulfide, bis(3-methyl-6-isocyanatophenyl) disulfide, bis(4-methyl-5-isocyanatophenyl) disulfide, bis(4-methoxy-3-isocyanatophenyl) disulfide, 1,2-diisothiocyanate benzene, 1,3-diisothiocyanate benzene, 1,4-diisothiocyanate benzene, 2,4-diisothiocyanate toluene, 2,5-diisothiocyanate-m-xylene, 4,4'-methylenebis(isothiocyanate phenyl), 4,4' -Methylenebis(2-methylphenylisothiocyanate), 4,4'-methylenebis(3-methylphenylisothiocyanate), 4,4'-diisothiocyanatebenzophenone, 4,4'-diisothiocyanate-3,3'-dimethylbenzophenone, bis(4-isothiocyanatophenyl)ether, 1-isothiocyanate-4-[(2-isothiocyanate)sulfonyl]benzene, thiobis(4-isothiocyanatebenzene), sulfonyl(4-isothiocyanatebenzene), hydrogenated toluene diisocyanate (H6TDI), diphenylmethane diisocyanate and dithiobis(4-isothiocyanatebenzene).

[0058] The isocyanate different from the hexamethylene diisocyanate may also have an isocyanate group and an isothiocyanate group, for example, 1-isocyanate-6-isothiocyanate hexane, 1-isocyanate-4-isothiocyanate cyclohexane, 1-isocyanate-4-isothiocyanate benzene, 4-methyl-3-isocyanate-1-isothiocyanate benzene, 2-isocyanate-4,6-diisothiocyanate-1,3,5-triazine, 4-isocyanatophenyl-4-isothiocyanatephenyl sulfide and 2-isocyanatoethyl-2-isothiocyanateethyl disulfide.

[0059] The isocyanate other than the hexamethylene diisocyanate may also be a halogen-substituted product of the above isocyanate, for example, a chlorine-substituted product, a bromine-substituted product, an alkyl-substituted product, an alkoxy-substituted product, a nitro-substituted product or a silane-substituted product such as isocyanatepropyltriethoxysilane or isocyanatepropyltrimethoxysilane.

[0060] Mixtures containing isocyanate-reactive groups

[0061] The "isocyanate-reactive group" of the present invention refers to a group containing a Zerevitinov-active hydrogen. The definition of a Zerevitinov-active hydrogen is given in Rompp's Chemical Dictionary (Rommp ChemieLexikon), 10 th ed., Georg Thieme Verlag Stuttgart, 1996. In general, a group containing a Zerevitinov-active hydrogen is understood in the art to mean a hydroxyl group (OH), an amino group (NH x ) and thiol groups (SH).

[0062] The amount of the mixture containing isocyanate-reactive groups is preferably 5% by weight to 90% by weight, preferably 10% by weight to 90% by weight, based on 100% by weight of the system.

[0063] The isocyanate-reactive group functionality of the mixture containing isocyanate-reactive groups is preferably 1-3, most preferably 1-2.

[0064] The melting enthalpy of the polymer polyol at 20° C. to 100° C. measured by DSC according to DIN 65467 is preferably 25 J / g to 100 J / g, most preferably 30 J / g to 80 J / g.

[0065] The polymer polyol has a hydroxyl functionality of 1.8-2.4.

[0066] The number average molecular weight of the polymer polyol is preferably 400 g / mol-5000 g / mol, most preferably 900 g / mol-3500 g / mol, and the number average molecular weight is measured at 40° C. by gel permeation chromatography using tetrahydrofuran as a mobile phase and comparing with a polystyrene standard.

[0067] The amount of the polymer polyol is 50 wt % to 99.9 wt %, based on 100 wt % of the mixture containing isocyanate reactive groups.

[0068] The polymer polyol is preferably a polyester polyol.

[0069] The polyester polyol is preferably one or more of the following: linear polyester polyol, slightly branched polyester polyol and homopolymer or mixed polymer of lactone.

[0070] The linear polyester polyols or slightly branched polyester polyols are prepared by comprising the following components: aliphatic, cycloaliphatic or aromatic di- or polycarboxylic acids, for example succinic acid, methylsuccinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, azelaic acid, decanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexanedicarboxylic acid, maleic acid, fumaric acid, malonic acid or trimellitic acid; anhydrides, for example phthalic anhydride, trimellitic anhydride or succinic anhydride or mixtures thereof; and low molecular weight polyols, and optionally higher functional polyols, for example trimethylolpropane, glycerol or pentaerythritol, cycloaliphatic and / or aromatic di- and poly-hydroxy compounds.

[0071] The homopolymers or mixed polymers of the lactones are preferably obtained by adding lactones or lactone mixtures such as butyrolactone, ε-caprolactone and / or methyl-ε-caprolactone to suitable di- and / or higher functional starter molecules. The ε-caprolactone is preferably a polymer of ε-caprolactone.

[0072] The polyester polyol is preferably 1,4-butanediol polyadipate diol.

[0073] The neutralization degree of the carboxyl group of the isocyanate-reactive compound containing a carboxyl group is preferably zero.

[0074] The carboxyl groups can be neutralized using organic or inorganic substances.

[0075] The isocyanate-reactive compound containing a carboxyl group is preferably one or more of the following: 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid and amino acids. The amino acids are preferably one or more of the following: lysine, 6-aminocaproic acid and proline.

[0076] The mixture containing isocyanate-reactive groups preferably further comprises a compound different from the polymer polyol or different from the isocyanate-reactive compound containing carboxyl groups, preferably one or more of the following: hydroxyl-containing compounds, thiol-containing compounds and amino-containing compounds.

[0077] The hydroxyl-containing compound is preferably one or more of the following: polyacrylate polyol, polyurethane polyol, polycarbonate polyol, polyether polyol, polyester polyacrylate polyol, polyurethane polyacrylate polyol, polyurethane polyester polyol, polyurethane polyether polyol, polycarbonate polyether polyol, polyurethane polycarbonate polyol, polyester polycarbonate polyol and a hydroxyl-functional compound having a molecular weight of 32 g / mol-400 g / mol.

[0078] The hydroxy-functional compound having a molecular weight of 32 g / mol to 400 g / mol is preferably one or more of the following: polyols having up to 20 carbon atoms, ester diols and monofunctional or isocyanate-reactive hydroxy-functional compounds.

[0079] The polyol having a maximum of 20 carbon atoms is preferably one or more of the following: ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, cyclohexanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol, neopentyl glycol, hydroquinone dihydroxyethyl ether, bisphenol A (2,2-bis(4-hydroxyphenyl)propane), hydrogenated bisphenol A (2,2-bis(4-hydroxycyclohexyl)propane), trimethylolpropane, glycerol and pentaerythritol.

[0080] The ester diol is preferably one or more of the following: α-hydroxybutyl-ε-hydroxycaproate, ω-hydroxyhexyl-γ-hydroxybutyrate, β-hydroxyethyl adipate and β-hydroxyethyl terephthalate.

[0081] The monofunctional or isocyanate-reactive hydroxyl-functional compound is preferably one or more of the following: ethanol, n-butanol, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monobutyl ether, 2-ethylhexanol, 1-octanol, 1-dodecanol, 1-hexadecanol, 1,6-hexanediol, 1,4-butanediol, neopentyl glycol and trimethylolpropane, and most preferably one or more of the following: 1,6-hexanediol, 1,4-butanediol, neopentyl glycol and trimethylolpropane.

[0082] The thiol group-containing compound is preferably one or more of the following: a compound containing at least one thiol group, a polythiol containing a thioether group, a polyester thiol, and an aromatic thio compound.

[0083] The amino-containing compound is preferably a mono-, di- or trifunctional amine and / or a mono-, di- or trifunctional hydroxylamine, further preferably one or more of the following: aliphatic and / or alicyclic primary and / or secondary monoamines, diamines and triamines, most preferably one or more of the following: 1,2-ethylenediamine, 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane (isophoronediamine), diethylenetriamine, diethanolamine, ethanolamine and N-(2-hydroxyethyl)-ethylenediamine.

[0084] The molar ratio of isocyanate groups to isocyanate-reactive groups of the system is preferably from 1.0 to 3.0.

[0085] Emulsifier

[0086] The anionic groups of the aqueous polyurethane dispersion of the present invention are mainly derived from the emulsifier.

[0087] The emulsifier of the present invention is a compound comprising an emulsifying group or a latent emulsifying group.

[0088] The amount of the emulsifier is preferably 0.1 wt % to 3 wt %, based on 100 wt % of the system.

[0089] The emulsifier preferably comprises at least one isocyanate-reactive group and at least one emulsifying or latent emulsifying group.

[0090] The isocyanate-reactive groups are preferably one or more of the following: hydroxyl, mercapto and amino.

[0091] The emulsifying group or potential emulsifying group is preferably one or more of the following: sulfonic acid group and carboxylic acid group.

[0092] The sulfonic acid group or carboxylic acid group may be used directly in the form of their salts, such as sulfonates or carboxylates.

[0093] The sulfonic acid group or carboxylic acid group can also be obtained by partially or completely adding a neutralizing agent to form a salt during or after the preparation process of the polyurethane polymer.

[0094] The neutralizing agent used for salt formation is preferably one or more of the following: triethylamine, dimethylcyclohexylamine, ethyldiisopropylamine, ammonia, diethanolamine, triethanolamine, dimethylethanolamine, sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, methyldiethanolamine and aminomethylpropanol, and most preferably one or more of the following: triethylamine, dimethylethanolamine, dimethylcyclohexylamine and ethyldiisopropylamine.

[0095] The emulsifier is most preferably one or more of the following: sulfonic acid compounds and carboxylic acid compounds.

[0096] The sulfonic acid compound is preferably one or more of the following: a diamino compound containing a sulfonic acid group and a dihydroxy compound containing a sulfonic acid group, and further preferably one or more of the following: sodium, potassium, lithium, or tertiary amine salts of N-(2-aminoethyl)-2-aminoethanesulfonic acid, N-(3-aminopropyl)-2-aminoethanesulfonic acid, N-(3-aminopropyl)-3-aminopropanesulfonic acid, and N-(2-aminoethyl)-3-aminopropanesulfonic acid, and most preferably N-(2-aminoethyl)-2-aminoethanesulfonic acid salt.

[0097] The carboxylic acid compound is preferably one or more of the following: diamino compounds containing carboxylic acid groups and dihydroxy compounds containing carboxylic acid groups, and is further preferably one or more of the following: sodium, potassium, lithium, tertiary amine salts of dimethylolpropionic acid or dimethylolbutanoic acid, and dimethylolpropionic acid is most preferred.

[0098] Solvents

[0099] The solvent is miscible with water but inert toward isocyanate groups.

[0100] The amount of the solvent is preferably 0.001 wt% to 20 wt%, most preferably 0.001 wt% to 3 wt%, based on 100 wt% of the system.

[0101] The solvent is preferably one or more of the following: acetone, 2-butanone, tetrahydrofuran, N-methylpyrrolidone, N-ethylpyrrolidone, acetonitrile, dipropylene glycol dimethyl ether and a solvent containing an ether or ester unit, and most preferably one or more of the following: acetone and 2-butanone.

[0102] The solvent may be added only at the beginning of the polyurethane preparation, or a portion may be added during the preparation process as required.

[0103] Reactive diluent

[0104] The amount of the reactive diluent is preferably 0.001 wt % to 90 wt %, based on 100 wt % of the system.

[0105] The reactive diluent is preferably one or more of the following: acrylic acid and acrylic ester.

[0106] The acrylate is preferably methacrylate.

[0107] Stabilizer

[0108] The stabilizer is beneficial to reducing the hydrolysis of the waterborne polyurethane dispersion and prolonging the applicable period of the waterborne polyurethane dispersion.

[0109] The applicable period of the present invention refers to the period from the initial reaction of the system to obtain the waterborne polyurethane dispersion to the time when the performance of the obtained waterborne polyurethane dispersion decreases and can no longer meet the use requirements.

[0110] The stabilizer is preferably one or more of the following: carbodiimide compounds, epoxy compounds, oxazoline compounds and aziridine compounds.

[0111] The content of the stabilizer is preferably 0.5 wt % to 10 wt %, most preferably 0.5 wt % to 2 wt %, based on 100 wt % of the system.

[0112] system

[0113] The system may further comprise an external emulsifier.

[0114] The amount of the external emulsifier is preferably 0.001 wt % to 10 wt %, based on 100 wt % of the system.

[0115] The external emulsifier is preferably a fatty alcohol polyether, and most preferably one or more of the following: aliphatic ethylene glycol polyether and aliphatic propylene glycol polyether.

[0116] The system may further comprise an organic antioxidant.

[0117] The amount of the organic antioxidant is preferably 0.06 wt % to 2.0 wt %, based on 100 wt % of the polyurethane.

[0118] The organic antioxidant is preferably one or more of the following: metal carbamate compounds, phenolic antioxidants, amine antioxidants and heterocyclic antioxidants, and phenolic antioxidants are most preferred.

[0119] The metal is preferably one or more of the following: copper, zinc, molybdenum and antimony.

[0120] The phenolic antioxidant is preferably one or more of the following: alkyl hindered phenols, polycyclic hindered phenols and alkylthio hindered phenols.

[0121] The amine antioxidant is preferably one or more of the following: phenylenediamine antioxidants, diphenylamine antioxidants, phenyl-α-naphthylamine antioxidants and phenothiazine antioxidants.

[0122] The heterocyclic antioxidant is preferably one or more of the following: sulfur-containing compounds and nitrogen-containing heterocyclic compounds.

[0123] Preparation method of waterborne polyurethane dispersion

[0124] The aqueous polyurethane dispersion can be prepared in a homogeneous system via one or more steps, or in the case of a multi-step reaction, partly in the dispersed phase. When the reaction of step ii is complete or partially complete, a dispersion, emulsification or dissolution step is performed. Optionally, further addition polymerization or modification is then carried out in the dispersed phase.

[0125] The solvent may be reacted under normal pressure or elevated pressure.

[0126] All processes known in the prior art can be used to prepare the aqueous polyurethane dispersion of the present invention, such as emulsifier / shear force method, acetone method, prepolymer mixing method, melt emulsification method, ketimine method and solid spontaneous dispersion method or its derivative method, preferably melt emulsification method or acetone method, most preferably acetone method. These methods are summarized in Methoden derorganischen Chemie (Houben-Weyl, Erweitenmgs-und zur4.Auflage, Volume E20, H Bartl and J. Falbe, Stuttgart, New York, Thieme 1987, p.1671-1682).

[0127] The acetone method generally first introduces all or part of the polyisocyanate mixture and the mixture containing isocyanate reactive groups to react and prepare the prepolymer, and optionally in the presence of a solvent that is miscible with water but inert to isocyanate groups, preferably without using a solvent, but heating to a higher temperature, preferably 50°C-120°C.

[0128] In order to accelerate the reaction rate of step i, a catalyst commonly used in the preparation of prepolymers may be used, such as triethylamine, 1,4-diazabicyclo-[2,2,2]-octane, tin dioctoate or dibutyltin dilaurate, preferably dibutyltin dilaurate.

[0129] The catalyst can be placed in the reactor simultaneously with the components in step i, or can be added afterwards.

[0130] The degree of conversion of the components in step i can be obtained by testing the NCO content in the components. To this end, the extracted samples can be simultaneously subjected to spectral measurements, such as infrared or near-infrared spectroscopy, and refractive index measurements or chemical analysis, such as titration.

[0131] The prepolymer may be in a solid state or a liquid state.

[0132] Any potentially ionic groups present in the prepolymer are converted to ionic form by partial or complete reaction with the neutralizing agent.

[0133] If the water used for dispersion already contains a neutralizing agent, neutralization can also be carried out simultaneously with dispersion.

[0134] The equivalent ratio of the isocyanate reactive groups of the compound for chain extension in step ii to the free isocyanate groups (NCO) of the prepolymer may be 40 mol % to 100 mol %, preferably 50 mol % to 100 mol %.

[0135] The components of step ii can be used alone or in combination in the form of water dilution or solvent dilution, and the order of addition can be arbitrary.

[0136] The step iii may use strong shearing such as strong stirring.

[0137] The solvent present in the aqueous polyurethaneurea dispersion can be removed by distillation. The solvent can be removed during step ii or step iii.

[0138] The amount of the residual organic solvent in the aqueous polyurethane dispersion is preferably less than 1.0% by weight, based on 100% by weight of the aqueous polyurethane dispersion.

[0139] Composition

[0140] The composition comprising the aqueous polyurethane dispersion is preferably a coating, an adhesive, a sealant or a printing ink.

[0141] The dispersions can be used alone or together with the additives known from coatings, adhesives, sealants or printing ink technology.

[0142] The additives may be one or more of the following: co-binders, lubricants, fillers, anti-settling agents, defoamers, wetting agents, flow regulators, antistatic agents, film-forming aids, plasticizers, neutralizers, catalysts, thickeners, pigments, dyes, tackifiers and matting agents.

[0143] The selection of the additives and the dosage used are known in principle to the person skilled in the art and can be easily determined.

[0144] The aqueous polyurethane dispersions of the invention can also be mixed and used together with other aqueous or solvent-containing oligomers or polymers, for example aqueous or solvent-containing polyesters, polyurethanes, polyurethane-polyacrylates, polyacrylates, polyethers, polyester-polyacrylates, alkyd resins, addition polymers, polyamides / imides or polyepoxides. The compatibility of such mixtures must be tested in each case by simple preliminary tests.

[0145] The aqueous polyurethane dispersion of the present invention may also be mixed with other compounds containing functional groups such as carboxyl groups, hydroxyl groups and / or blocked isocyanate groups and used together.

[0146] The coating, adhesive, sealant or printing ink of the present invention is obtained by processing according to methods known to those skilled in the art.

[0147] Adhesives

[0148] The thermal activation temperature of the adhesive is preferably 35°C-70°C.

[0149] The adhesive preferably further comprises a crosslinking agent containing carboxyl-reactive groups.

[0150] The crosslinking agent is preferably a compound containing a polycarbodiimide group.

[0151] The content of the crosslinking agent is preferably 0.1 wt % to 10 wt %, based on 100 wt % of the binder.

[0152] Adhesive products

[0153] The substrate is preferably one or more of the following: rubber, plastic, paper, cardboard, wood, textile, metal, alloy, fabric, fiber, artificial leather, leather, inorganic material, human or animal hair and human or animal skin, most preferably one or more of the following: rubber and plastic.

[0154] The bonded article is preferably a shoe sole or a shoe shaft.

[0155] The bonded article is preferably a film or wood.

[0156] Method for making bonded article

[0157] The method preferably further comprises a step D between step B and step C: irradiating the surface of the substrate treated in step B with actinic radiation.

[0158] The method for manufacturing the adhesive product preferably comprises the following steps:

[0159] A. applying the adhesive provided by the present invention to at least one surface of a substrate;

[0160] B. heating and drying the substrate surface to which the adhesive is applied;

[0161] D. irradiating the surface of the substrate treated in step B with actinic radiation; and

[0162] C. contacting the surface of the substrate treated in step D with the surface of the substrate itself or another substrate to obtain the bonded article.

[0163] The substrate is preferably one or more of the following: rubber, plastic, paper, cardboard, wood, textile, metal, alloy, fabric, fiber, artificial leather, leather, inorganic material, human or animal hair and human or animal skin, most preferably one or more of the following: rubber and plastic.

[0164] The applying may be applying the adhesive to the entire surface of the substrate or only to one or more portions of the surface of the substrate.

[0165] The application can be by brushing, dipping, spraying, rolling, knife coating, flow coating, pouring, printing or transfer, preferably by brushing, dipping or spraying.

[0166] The heating and drying of the substrate surface to which the adhesive is applied may refer to heating and drying only the substrate surface, or may refer to heating and drying a part of the substrate or the entire substrate including the substrate surface to which the adhesive is applied.

[0167] The heating and drying can remove volatile components. The volatile components can be water.

[0168] The heating and drying is preferably one or more of the following: infrared heat radiation, near infrared heat radiation, microwaves, and convection oven or spray dryer under elevated temperature conditions.

[0169] The heating temperature is as high as possible, but should not be higher than the temperature limit at which the substrate deforms in an uncontrollable manner or suffers other damage.

[0170] The irradiation with actinic radiation is preferably carried out when the surface temperature of the substrate treated in step B is not less than 35°C, and most preferably carried out immediately after the treatment in step B.

[0171] The actinic radiation irradiating the substrate surface treated in step B may refer to irradiating only the substrate surface, or may refer to irradiating a part of the substrate including the substrate surface, or the entire substrate.

[0172] The actinic radiation crystallizes and cures the adhesive.

[0173] The actinic radiation is preferably UV radiation, sunlight radiation, radiation with an inert gas or oxygen-deficient gas under the exclusion of oxygen, or radiation with a medium transparent to the radiation covering the site to be irradiated, most preferably UV radiation or sunlight radiation.

[0174] The inert gas is preferably nitrogen or carbon dioxide. The radiation-transparent medium is preferably a synthetic film, glass or a liquid such as water.

[0175] The UV radiation or sunlight radiation can be applied with medium-pressure or high-pressure mercury vapor lamps, optionally modified by doping with other elements, such as gallium or iron, or with lasers, pulsed lamps, halogen lamps or excimer radiators.

[0176] The actinic radiation is most preferably UV radiation. The UV radiation is most preferably using fixed mounted mercury radiation.

[0177] When the substrate has a three-dimensional surface with a complex shape, it is preferred to use multiple radiation devices for radiation, and the radiation devices are properly arranged so that the surface receives radiation uniformly.

[0178] The wavelength of the actinic radiation is preferably from 200 nm to 750 nm.

[0179] The dose of the actinic radiation is preferably not less than 80 mJ / cm 2 , more preferably 80 mJ / cm 2 -5000 mJ / cm 2 , and preferably 200 mJ / cm 2 -2000 mJ / cm 2 , most preferably 1250 mJ / cm 2 -1950 mJ / cm 2 .

[0180] Within the above range, the dose of actinic radiation may be as high as possible, but should not be higher than the dose limit at which the substrate deforms in an uncontrollable manner or suffers other damage.

[0181] The contact is preferably carried out before the temperature of the substrate surface drops below the bonding temperature of the adhesive, and more preferably before the substrate surface temperature is not less than 60°C.

[0182] The surface of the substrate treated in step D is preferably contacted with the substrate itself or another substrate within one hour, more preferably within 30 minutes, more preferably within 10 minutes, and most preferably within 5 minutes to obtain the bonded product.

[0183] The additional substrate may be any substrate to which bonding is desired.

[0184] The additional substrate may be the same as or different from the base material.

[0185] The additional substrate is preferably coated, heated and treated with actinic radiation in the same manner as the base substrate.

[0186] The additional substrate is preferably not treated with a primer, high energy radiation or ozone prior to contacting the substrate surface.

[0187] The high energy radiation may be ionizing radiation, in particular plasma.

[0188] After the surface of the substrate treated in step B or in step D is brought into contact with the substrate itself or the other substrate, a heat treatment may be further performed.

[0189] After the surface of the substrate treated in step B or in step D is brought into contact with the substrate itself or the other substrate, a cooling treatment may be further performed to reduce the temperature of the bonded product to room temperature.

[0190] The method of introducing heat is preferably one or more of the following: transferring heat at elevated temperature using a convection oven or spray dryer, infrared heat radiation, near infrared heat radiation, microwaves, and an object in contact with the substrate coated with the adhesive of the present invention.

[0191] Preferably, no heat needs to be introduced to the substrate surface prior to contacting the substrate surface after treatment in step B or after treatment in step D with itself or another substrate. Example

[0192] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention belongs. When the definition of a term in this specification conflicts with the meaning commonly understood by those skilled in the art to which the invention belongs, the definition described in this article shall prevail.

[0193] Unless otherwise indicated, all numerical values ​​expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are to be understood as modified by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth herein are approximations that can vary depending upon the desired properties desired to be obtained.

[0194] As used herein, "and / or" means one or all of the mentioned elements.

[0195] As used herein, “including” and “comprising” encompasses the case where only the stated elements are present as well as the case where there are other elements other than the stated elements.

[0196] All percentages in the present invention are by weight, unless otherwise specified.

[0197] The analytical measurements of the present invention were all carried out at 23±2°C unless otherwise stated.

[0198] The solids content of the aqueous polyurethane dispersions was determined using a HS153 moisture analyzer from Mettler Toledo in accordance with DIN-EN ISO 3251.

[0199] The isocyanate group (NCO) content is determined by volume in accordance with DIN-EN ISO 11909. The data determined include both the free and potentially free NCO content.

[0200] The viscosity of the aqueous polyurethane dispersion was measured at 23° C. using a DV-II+Pro. rotational viscometer from Brookfield according to DIN 53019.

[0201] The pH value of the aqueous polyurethane dispersion was measured at 23°C using a PB-10 pH meter from Sartorius, Germany.

[0202] The acid value was determined by acid-base titration.

[0203] The degree of neutralization is calculated based on the molar number of carboxyl groups and neutralizing agent.

[0204] The number average molecular weight and weight average molecular weight of polyurethane were determined by gel permeation chromatography. The aqueous polyurethane dispersion was coated on a polytetrafluoroethylene plate and dried naturally at room temperature to obtain a dry film. An appropriate amount of dry film was weighed and dissolved in tetrahydrofuran at a concentration of 8 mg / mL. The Agilent 1260 was used for testing at a column temperature of 35°C, an injection volume of 60 µL, and a flow rate of 0.7 mL / min. The test results were calculated using a polystyrene standard as a reference, and the molecular weight above 100 was selected for calculation.

[0205] Materials and reagents

[0206] Polyester I: 1,4-butanediol polyadipate diol, OH value 50, melting temperature 49°C, melting enthalpy 91.0 J / g, number average molecular weight 2323 g / mol, can be purchased from Covestro AG, Germany.

[0207] Polyester II: a polyester diol composed of 1,6-hexanediol, neopentyl glycol and adipic acid, with an OH value of 66 and a number average molecular weight of 1691 g / mol, which can be purchased from Covestro AG of Germany.

[0208] Desmodur ® H: 1,6-hexamethylene diisocyanate, purchased from Covestro AG.

[0209] Desmodur ® I: isophorone diisocyanate, purchased from Covestro AG.

[0210] DMPA: 2,2-dihydroxymethylpropionic acid, purchased from Aldrich Chemical Company.

[0211] L-Lysine: 50% L-lysine aqueous solution, available from Xiamen Feihe Chemical.

[0212] AAS: sodium diaminosulfonate NH2-CH2CH2-NH-CH2CH2-SO3Na, 45% concentration in water, purchased from Covestro AG.

[0213] Rubber treatment agent: B powder (trichloroisocyanuric acid) was dissolved in ethyl acetate at a concentration of 2% by weight.

[0214] Waterborne polyurethane dispersion 1

[0215] 450 g of polyester I and 42.5 g of polyester II were dehydrated at 110° C., 100 mbar for 1 hour, 2.25 g of 1,4-butanediol were added and cooled while stirring. 37.84 g of Desmodur ® H and 25g Desmodur ® I, stirred at 80-90°C until the isocyanate group content reached 1.3%. Then dissolved in 840g of acetone and cooled to 50°C to obtain a reaction solution. A solution of 5.6g of AAS, 3.2g of diethanolamine, and 1.8g of 6-aminocaproic acid in 56g of water was added to the reaction mixture solution and stirred vigorously for 30 minutes, then 510g of water was added to disperse the mixture, and then acetone was separated by distillation to obtain an aqueous polyurethane dispersion 1.

[0216] Waterborne polyurethane dispersion 2

[0217] 450 g of polyester I and 42.5 g of polyester II were dehydrated at 110° C., 100 mbar for 1 hour, 1.58 g of 1,4-butanediol and 1.01 g of DMPA were added and cooled while stirring. 37.84 g of Desmodur ® H and 25g Desmodur ® I, stirred at 80-90°C until the isocyanate group content reached 1.3%. Then dissolved in 840g of acetone and cooled to 50°C to obtain a reaction solution. A solution of 5.6g of AAS, 1.7g of diethanolamine, and 1.2g of hydroxyethylethylenediamine in 56g of water was added to the reaction mixture solution and stirred vigorously for 30 minutes, then 510g of water was added to disperse the mixture, and then acetone was separated by distillation to obtain an aqueous polyurethane dispersion 2.

[0218] Waterborne polyurethane dispersion 3

[0219] 450 g of polyester I and 42.5 g of polyester II were dehydrated at 110° C., 100 mbar for 1 hour, 2.25 g of 1,4-butanediol were added and cooled while stirring. 37.84 g of Desmodur ® H and 25g Desmodur ®I, stirred at 80-90°C until the isocyanate group content reached 1.3%. Then dissolved in 840g of acetone and cooled to 50°C to obtain a reaction solution. A solution of 5.6g of AAS, 2.2g of 6-aminocaproic acid and 1.2g of hydroxyethylethylenediamine in 56g of water was added to the reaction mixture solution and stirred vigorously for 30 minutes, then 510g of water was added to disperse the mixture, and then acetone was separated by distillation to obtain an aqueous polyurethane dispersion 3.

[0220] Waterborne polyurethane dispersion 4

[0221] 450 g of polyester I and 42.5 g of polyester II were dehydrated at 110° C., 100 mbar for 1 hour, 3.4 g of DMPA were added and cooled while stirring. 37.84 g of Desmodur ® H and 25g Desmodur ® I, stirred at 80-90°C until the isocyanate group content reached 1.3%. Then dissolved in 840g of acetone and cooled to 50°C to obtain a reaction solution. A solution of 5.6g of AAS, 1.4g of diethanolamine and 1.2g of hydroxyethylethylenediamine in 56g of water was added to the reaction mixture solution and stirred vigorously for 30 minutes, then 510g of water was added to disperse the mixture, and then acetone was separated by distillation to obtain an aqueous polyurethane dispersion 4.

[0222] Waterborne polyurethane dispersion 5

[0223] 360 g of polyester I and 34 g of polyester II were dehydrated at 110° C., 100 mbar for 1 hour, 1.8 g of DMPA was added and cooled while stirring. 30.27 g of Desmodur ® H and 20g Desmodur ® I, stirred at 80-90°C until the isocyanate group content reached 1.4%. Then dissolved in 670g of acetone and cooled to 50°C to obtain a reaction solution. A solution of 4.5g of AAS, 1.9g of diethanolamine and 0.6g of hydroxyethylethylenediamine in 40g of water was added to the reaction mixture solution and stirred vigorously for 30 minutes, then 410g of water was added to disperse the mixture, and then acetone was separated by distillation to obtain an aqueous polyurethane dispersion 5.

[0224] Waterborne polyurethane dispersion 6

[0225] 315 g of polyester I were dehydrated at 110° C., 100 mbar for 1 hour, 6.7 g of DMPA were added and cooled while stirring. 30.77 g of Desmodur ®H and 20.33 g Desmodur ® I, stirred at 80-90°C until the isocyanate group content reached 1.9%. Then dissolved in 260g of acetone and cooled to 50°C to obtain a reaction solution. A solution of 8.3g of 6-aminocaproic acid and 2.0g of hydroxyethylethylenediamine in 40g of water was added to the reaction mixture solution and stirred vigorously for 30 minutes, then 5.1g of triethylamine was added and stirred for 10 minutes, then 350g of water was added to disperse the mixture, and then acetone was separated by distillation to obtain an aqueous polyurethane dispersion 6.

[0226] Waterborne polyurethane dispersion 7

[0227] 450 g of polyester I and 42.5 g of polyester II were dehydrated at 110° C., 100 mbar for 1 hour, 3.4 g of DMPA were added and cooled while stirring. 37.84 g of Desmodur ® H and 25g Desmodur ® I, stirred at 80-90°C until the isocyanate group content reached 1.3%. Then dissolved in 840g of acetone and cooled to 50°C to obtain a reaction solution. A solution of 5.6g of AAS and 2.2g of hydroxyethylethylenediamine in 56g of water was added to the reaction mixture solution and stirred vigorously for 30 minutes, then 510g of water was added to disperse the mixture, and then acetone was separated by distillation to obtain aqueous polyurethane dispersion 7.

[0228] Waterborne polyurethane dispersion 8

[0229] 394 g of polyester I were dehydrated at 110° C., 100 mbar for 1 hour, 13.4 g of DMPA were added and cooled while stirring. 41.5 g of Desmodur ® H and 27.6g Desmodur ® I, stirred at 80-90°C until the isocyanate group content reached 1.7%. Then dissolved in 720g of acetone and cooled to 50°C to obtain a reaction solution. A solution of 1.8g of L-lysine, 8.3g of 6-aminocaproic acid, and 2.3g of hydroxyethylethylenediamine in 50g of water was added to the reaction mixture solution and stirred vigorously for 30 minutes, 10.1g of triethylamine was added and stirring continued for 10 minutes, 510g of water was added to disperse the mixture, and acetone was subsequently distilled off to obtain an aqueous polyurethane dispersion 8.

[0230] Waterborne polyurethane dispersion 9

[0231] 450 g of polyester I and 42.5 g of polyester II were dehydrated at 110° C., 100 mbar for 1 hour, 2.25 g of 1,4-butanediol were added and cooled while stirring. 37.84 g of Desmodur ® H and 25g Desmodur ® I, stirred at 80-90°C until the isocyanate group content reached 1.3%. Then dissolved in 840g of acetone and cooled to 50°C to obtain a reaction solution. A solution of 5.6g of AAS, 0.8h of diethanolamine and 1.7g of hydroxyethylethylenediamine in 56g of water was added to the reaction mixture solution and stirred vigorously for 30 minutes, then 510g of water was added to disperse the mixture, and then acetone was separated by distillation to obtain an aqueous polyurethane dispersion 9.

[0232] Waterborne polyurethane dispersion 10

[0233] 382.5 g of polyester II were dehydrated at 110° C., 100 mbar for 1 hour, 3.4 g of DMPA were added and cooled while stirring. 37.84 g of Desmodur ® H and 25g Desmodur ® I, stirred at 80-90°C until the isocyanate group content reached 1.6%. Then dissolved in 670g of acetone and cooled to 50°C to obtain a reaction solution. A solution of 4.7g of AAS, 0.6g of diethanolamine and 2.1g of hydroxyethylethylenediamine in 56g of water was added to the reaction mixture solution and stirred vigorously for 30 minutes, then 400g of water was added to disperse the mixture, and then acetone was separated by distillation to obtain an aqueous polyurethane dispersion 10.

[0234] Waterborne polyurethane dispersion 11

[0235] 450 g of polyester I and 42.5 g of polyester II were dehydrated at 110° C., 100 mbar for 1 hour, 2.25 g of 1,4-butanediol were added and cooled while stirring. 75 g of Desmodur ® I, stirred at 80-90°C until the isocyanate group content reached 1.3%. Then dissolved in 840g of acetone and cooled to 50°C to obtain a reaction solution. A solution of 5.6g of AAS, 2.7g of 6-aminocaproic acid and 0.9g of hydroxyethylethylenediamine in 56g of water was added to the reaction mixture solution and stirred vigorously for 30 minutes, then 510g of water was added to disperse the mixture, and then acetone was separated by distillation, and the emulsion was broken during the distillation process.

[0236] Initial adhesion test

[0237] After mechanical grinding of black rubber (10cm*2cm), rubber treatment agent was applied. After the rubber treatment agent was dried, the aqueous polyurethane dispersion of the present invention and the comparative example was applied to the pretreated black rubber using a brush. The coating started from one end of the black rubber, and the coating area was 3.5cm*2cm. The black rubber was dried and activated in an oven at 60°C for 3 minutes. The black rubber with the aqueous polyurethane dispersion of the present invention and the comparative example was pasted on one side, and pressed for 5 seconds using the YC-500 hydraulic press of Master Tech Company under a pressure of 4.5kg. The pressure was removed and placed at room temperature (temperature 23±2°C, humidity 50±5%) for 5 minutes, and the debonding length was measured with a ruler. The above method was used to perform secondary tests on each dispersion, and the data are listed in Table 1. The larger the debonding length, the worse the initial bonding force of the aqueous polyurethane dispersion.

[0238] Table 1 shows the parameters and performance test results of the aqueous polyurethane dispersions of the embodiments of the present invention and the comparative embodiments.

[0239]

[0240] As can be seen from Table 1: the debonding length of the black rubber obtained by bonding the aqueous polyurethane dispersions of Examples 1-4 is significantly shorter than that of Comparative Examples 1-6, indicating that the initial bonding force of the aqueous polyurethane dispersion of the present invention is significantly better than that of the comparative example. In Comparative Examples 1-6, when the acid value of the aqueous polyurethane dispersion is less than 0.5 or greater than 8.5, the weight-average molecular weight is less than 31,000 or greater than 95,000, or the polyurethane is non-crystalline, i.e., the melting enthalpy is 0, the debonding length of the black rubber obtained by bonding them is long or even debonded, indicating that the initial bonding force of the aqueous polyurethane dispersion of the comparative example is poor. As can be seen from Comparative Example 7, when the polyisocyanate mixture of the system for preparing the aqueous polyurethane dispersion does not contain hexamethylene diisocyanate, the demulsification during the preparation of the aqueous polyurethane dispersion cannot form a dispersion.

[0241] It is easy for a person skilled in the art to know that the present invention is not limited to the above-mentioned specific details, and the present invention can be implemented in other specific forms without departing from the spirit or main characteristics of the present invention. Therefore, the embodiments described should be regarded as illustrative rather than restrictive from any point of view, so that the scope of the present invention is indicated by the claims rather than the above description; and therefore any changes, as long as they fall within the meaning and scope of the equivalents of the claims, should be regarded as belonging to the present invention.

Claims

1. An aqueous polyurethane dispersion comprising a polyurethane having an anionic group dispersed therein, wherein the polyurethane has a melting enthalpy of 3 J / g-100 J / g at 20° C.-100° C. measured by DSC according to DIN 65467, a weight average molecular weight of 31000-95000, and an acid value of 0.5 mg KOH / g-8.5 mg KOH / g.

2. The aqueous polyurethane dispersion according to claim 1, characterized in that The anionic group is located on the side chain of the polyurethane, and the anionic group is one or more of the following: a sulfonate group and a carboxylate group.

3. The aqueous polyurethane dispersion according to claim 1 or 2, characterized in that The melting enthalpy of the polyurethane at 20° C. to 100° C. measured by DSC according to DIN 65467 is 25 J / g to 100 J / g.

4. The aqueous polyurethane dispersion according to claim 1 or 2, characterized in that The carboxyl group content of the polyurethane is 0.1 wt % to 1.5 wt %, based on 100 wt % of the polyurethane.

5. The aqueous polyurethane dispersion according to claim 1 or 2, characterized in that The polyurethane is obtained by reacting a system comprising the following components: a. a polyisocyanate mixture containing hexamethylene diisocyanate; b. a mixture containing isocyanate-reactive groups, the mixture containing isocyanate-reactive groups comprising a polymer polyol having a number average molecular weight of 400 g / mol-8000 g / mol and an isocyanate-reactive compound containing a carboxyl group; c. an emulsifier; d. an optional solvent; e. optionally a reactive diluent; and f. an optional stabilizer; The melting enthalpy of the polymer polyol at 20°C-100°C measured by DSC according to DIN 65467 is 3 J / g-100 J / g, the amount of the isocyanate-reactive compound containing a carboxyl group is 0.1 wt%-1.5 wt%, based on 100 wt% of the polyurethane, and the degree of neutralization of the carboxyl group of the isocyanate-reactive compound containing a carboxyl group is 0-50%.

6. The aqueous polyurethane dispersion according to claim 5, characterized in that The melting enthalpy of the polymer polyol at 20° C. to 100° C. measured by DSC in accordance with DIN 65467 is 25 J / g to 100 J / g.

7. The aqueous polyurethane dispersion according to claim 5, characterized in that The neutralization degree of the carboxyl group of the isocyanate-reactive compound containing a carboxyl group is 0.

8. The aqueous polyurethane dispersion according to claim 1 or 2, characterized in that The molar ratio of isocyanate groups to isocyanate-reactive groups in the aqueous polyurethane dispersion is 1.0-3.

0.

9. A method for preparing an aqueous polyurethane dispersion according to any one of claims 1 to 8, comprising the following steps: i. reacting some or all of the polyisocyanate mixture and the mixture containing isocyanate-reactive groups to obtain a prepolymer, the reaction being carried out in the presence of an optional solvent or adding an optional solvent after the reaction to dissolve the prepolymer; ii. reacting the prepolymer, the emulsifier, the optional reactive diluent, the optional stabilizer, the polyisocyanate mixture not added in step i, and the mixture containing isocyanate-reactive groups not added in step i to obtain the polyurethane; and iii. before, during or after step ii, introducing water and optionally an emulsifier to obtain the aqueous polyurethane dispersion; The aqueous polyurethane dispersion contains a polyurethane having an anionic group dispersed therein, wherein the polyurethane has a melting enthalpy of 3 J / g to 100 J / g at 20° C. to 100° C. measured by DSC according to DIN 65467, a weight average molecular weight of 31000 to 95000, and an acid value of 0.5 mgKOH / g to 8.5 mgKOH / g.

10. A composition comprising the aqueous polyurethane dispersion according to any one of claims 1 to 8.

11. The composition according to claim 10, characterized in that The composition is a coating, an adhesive, a sealant or a printing ink.

12. An adhesive comprising the aqueous polyurethane dispersion according to any one of claims 1 to 8.

13. The adhesive according to claim 12, characterized in that The thermal activation temperature of the adhesive is 35°C-70°C.

14. The adhesive according to claim 12 or 13, characterized in that The invention further comprises a cross-linking agent containing a carboxyl reactive group.

15. A bonded article comprising substrates bonded with an adhesive according to any one of claims 12 to 14.

16. The adhesive product according to claim 15, characterized in that The substrate is one or more of the following: rubber, plastic, paper, wood, textile, metal, fiber, leather, inorganic material, human or animal hair and human or animal skin.

17. The adhesive product according to claim 15, characterized in that The substrate is one or more of the following: cardboard, alloy, fabric, and artificial leather.

18. The adhesive product according to claim 15 or 16, characterized in that The bonded article is a shoe sole or a shoe shaft.

19. The adhesive product according to claim 15 or 16, characterized in that The bonded article is a film or wood.

20. A method for manufacturing an adhesive product, comprising the steps of: A. applying the adhesive according to any one of claims 12 to 14 to at least one surface of a substrate; B. heating and drying the substrate surface to which the adhesive is applied; and C. contacting the surface of the substrate treated in step B with the surface of the substrate itself or another substrate to obtain the bonded product.

21. The method of claim 20, wherein: The method further comprises a step D between step B and step C: irradiating the surface of the substrate treated in step B with actinic radiation.

22. Use of the aqueous polyurethane dispersion according to any one of claims 1 to 8 in the production of adhesive articles.

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