CN112778487A

CN112778487A - Aqueous dispersion of polyurethane or polyurethane-urea, preparation method and application thereof

Info

Publication number: CN112778487A
Application number: CN201911070180.XA
Authority: CN
Inventors: 宋泽峰; 孙永建; 纪学顺; 黎会亮; 张延成; 王远勇
Original assignee: Wanhua Chemical Group Co Ltd; Wanhua Chemical Ningbo Co Ltd; Wanhua Chemical Guangdong Co Ltd
Current assignee: Wanhua Chemical Group Co Ltd; Wanhua Chemical Ningbo Co Ltd; Wanhua Chemical Guangdong Co Ltd
Priority date: 2019-11-05
Filing date: 2019-11-05
Publication date: 2021-05-11

Abstract

The invention belongs to the technical field of polyurethane aqueous dispersion, and particularly relates to polyurethane or polyurethane-urea aqueous dispersion, a preparation method and application thereof, wherein the polyurethane or polyurethane-urea is prepared by reacting raw materials comprising the following components: a) a compound containing a tertiary amine group and at least one NCO-reactive functional group, b) a polyester polyol having a number average molecular weight of 400 to 5000 and a functionality of 2 to 3, c) an organic compound having at least two isocyanate groups, d) a hydrophilic compound containing one or more of an ionic group, a potentially ionic group and a non-ionic group and containing 2 to 3 NCO-reactive functional groups, e) a monofunctional non-ionic hydrophilic compound containing at least one NCO-reactive functional group. The aqueous dispersion has stable storage and long storage time, improves the hydrolysis resistance of the adhesive prepared from the aqueous dispersion, and can keep better bonding strength and heat resistance.

Description

Aqueous dispersion of polyurethane or polyurethane-urea, preparation method and application thereof

Technical Field

The invention belongs to the technical field of polyurethane aqueous dispersion, and particularly relates to polyurethane or polyurethane-urea aqueous dispersion as well as a preparation method and application thereof.

Background

Aqueous dispersions of polyurethanes or polyurethaneureas have been widely used in the fields of coatings, adhesives and textile coatings, due to their excellent paintability, excellent initial and peel strength and outstanding resistance. When the aqueous dispersion of polyurethane or polyurethane urea is used in an adhesive, in order to improve the performance of the adhesive, polyester polymer polyol is mainly adopted for synthesis, and during the processing, using and storing processes of ester polymer, irreversible hydrolysis reaction can occur due to the action of water vapor and acidic substances existing in the environment. The cracking and breaking of macromolecules caused by hydrolysis directly result in the reduction of tensile strength, modulus and hardness and the increase of elongation at break of the material, so that the bonding strength is reduced, and bonding failure is caused. Therefore, how to efficiently and simply improve the water resistance of the aqueous polyurethane or polyurethane urea becomes a problem to be solved by those skilled in the art.

In patent documents DE19954500, DE4410557 or EP792908 it is proposed to introduce carboxylic acid salts into aqueous dispersions of polyurethanes or polyurethane ureas, which are then formulated with carbodiimides to improve the adhesion properties, mainly by increasing the crosslinking density and increasing the strength of the adhesive by reaction of the carboxylic acids with the carbodiimides. Wherein the carboxylic acid salt is obtained by adding dimethylolpropionic acid to polyurethane or polyurethane urea and then neutralizing with tertiary amine. However, in the formulation scheme of the adhesive, the reactivity of carboxyl and carbodiimide is low, and the finally obtained performance is usually not enough to meet the requirement of the adhesive on normal-temperature hydrolysis resistance.

Patent document EP1272588 describes an adhesive composite containing at least one crystalline polyester-polyurethane dispersion, a polyacrylate copolymer, a polychloroprene dispersion, a heat-curable resin and stabilizers (aminoalcohols, carbodiimides and magnesium oxide), wherein the stabilizers used have the function of inhibiting hydrolysis of the polyester in the system and of keeping the system stable. However, such multi-component systems are expensive and fail quickly, which severely limits their use in real life.

Patent document CN102216359 describes that a water dispersion of polyurethane or polyurethane urea containing carboxyl at the terminal is obtained by adding monoamino and/or monohydroxy carboxylic acid during the synthesis process, and then compounded with carbodiimide to form an adhesive; because of the high activity of the terminal carboxyl, the modified carboxyl can generate rapid crosslinking reaction with carbodiimide, thereby obviously improving the performance of the coating. However, these carboxylic acids can influence the stability of the aqueous polyurethane or polyurethane urea dispersions, and the carbodiimides themselves are not very stable, which is disadvantageous for the storage of such systems.

Patent document CN103980461 describes a synthesis method of an aqueous dispersion containing an epoxy resin crosslinking agent and 1-aminopropyl-2-methylimidazole, which can generate a covalent bond mixed network structure through the reaction of 1-aminopropyl-2-methylimidazole and-NCO groups in a prepolymer, thereby forming a hybrid network structure, and simultaneously introduce epoxy resin to form a crosslinked structure, thereby improving the water resistance of the product. However, the use of a crosslinking agent and the formation of a network structure affect the activation of the product, and further affect the initial tack, strength, etc. of the product.

Patent document CN106634785 describes the preparation of a highly water-resistant aqueous polyurethane adhesive, which uses stearic acid, lipase and hydrogen peroxide to perform epoxy modification on cottonseed oil and castor oil, and then mixes the modified cottonseed oil and castor oil with KH-550 to obtain modified oil; and finally, mixing the modified waterborne polyurethane emulsion with substances such as a water reducing agent, a crosslinking agent and the like to obtain the waterborne polyurethane adhesive with water resistance. The method has complex process steps, uses more raw materials and is not beneficial to industrialized production and control. In addition, the crosslinking agent used in the adhesive is more, so that other performance deviations of the adhesive are caused.

Although the above patent documents can improve hydrolysis resistance to a certain extent, they all use a network structure in which a cross-linking agent cross-links polymer molecules, and this kind of method is not suitable for use in an activating product. The activation means that: after the aqueous dispersion is coated on a substrate, water is removed by heating, and at this temperature, the mobility of the polyurethane segment is increased, and the polyurethane or the polyurethane urea is converted into a viscoelastic state, followed by bonding or the like. In the polyurethane or polyurethane urea aqueous dispersion, the crosslinked structure reduces the mobility of the polyurethane chain segment, so that the activation is insufficient, and the initial viscosity, the strength, the heat resistance and other properties are influenced.

Therefore, it is important to search for a hydrolysis-resistant aqueous polyurethane or polyurethane urea dispersion which does not affect the initial tack, strength, heat resistance and the like of the product during the activation treatment.

Disclosure of Invention

The invention aims to provide a water dispersion of polyurethane or polyurethane-urea with hydrolysis resistance and a preparation method and application thereof aiming at the problem of improving the hydrolysis resistance of the water dispersion of polyurethane or polyurethane-urea prepared by taking polyester polyol as a raw material in the prior art, the side chain or the main chain of the polyurethane or polyurethane-urea contained in the water dispersion contains tertiary amine groups (tertiary amine groups), so that the acid substances in a system can be eliminated due to stronger alkalinity of the tertiary amine groups in the storage process of the water dispersion, further eliminates the catalytic action of acid substances on the ester polymer, greatly reduces the hydrolysis rate of the ester polymer, ensures that the aqueous dispersion is stable in storage and long in storage time, and the hydrolysis resistance of the adhesive prepared from the dispersion can be greatly improved, and the better bonding strength and heat resistance of the adhesive can be maintained.

In order to achieve the purpose, the technical scheme of the invention is as follows:

in one aspect of the present invention, there is provided an aqueous dispersion of a hydrolysis-resistant polyurethane or polyurethane-urea, the polyurethane or polyurethane-urea contained in the aqueous dispersion being prepared by reacting raw materials comprising:

a) a compound containing a tertiary amine group and at least one NCO-reactive functional group,

b) a polyester polyol having a number average molecular weight of 400 to 5000 and a functionality of 2 to 3,

c) an organic compound having at least two isocyanate groups,

d) a hydrophilic compound containing one or more of an ionic group, a potentially ionic group and a non-ionic group and containing 2 to 3 NCO-reactive functional groups,

e) monofunctional nonionically hydrophilicizing compounds having at least one NCO-reactive functional group,

f) optionally, a compound containing 1 to 3 NCO reactive functional groups,

g) optionally, a blocking agent in the isocyanate field or an unsaturated compound containing a polymerization reactive group.

The aqueous dispersions of polyurethanes or polyurethane-ureas provided according to the present invention, in some instances, are based on the total weight of the components (e.g., 100 wt%),

the amount of component a) is 0.02 to 5 wt.% (0.04 wt.%, 0.08 wt.%, 0.1 wt.%, 0.5 wt.%, 1 wt.%, 1.2 wt.%, 1.5 wt.%, 1.8 wt.%, 2 wt.%, 2.5 wt.%, 3.5 wt.%, 4 wt.%, 4.5 wt.%), preferably 0.05 to 3 wt.%;

the amount of component b) is 5 to 94 wt.% (8 wt.%, 15 wt.%, 20 wt.%, 30 wt.%, 40 wt.%, 50 wt.%, 60 wt.%, 65 wt.%, 74 wt.%, 76 wt.%, 80 wt.%, 85 wt.%), preferably 70 to 90 wt.%;

the amount of component c) is 5 to 40 wt.% (6 wt.%, 10 wt.%, 13 wt.%, 15 wt.%, 18 wt.%, 25 wt.%, 30 wt.%, 35 wt.%), preferably 8 to 20 wt.%;

the amount of component d) is 0.2 to 50 wt.% (0.4 wt.%, 0.8 wt.%, 1.5 wt.%, 2 wt.%, 4 wt.%, 8 wt.%, 15 wt.%, 20 wt.%, 30 wt.%, 40 wt.%), preferably 1 to 5 wt.%;

the amount of component e) is 0.01 to 20 wt.% (0.04 wt.%, 0.08 wt.%, 0.1 wt.%, 0.5 wt.%, 0.8 wt.%, 1 wt.%, 1.5 wt.%, 2 wt.%, 3.5 wt.%, 5 wt.%, 10 wt.%, 15 wt.%), preferably 0.5 to 3 wt.%;

the component f) is used in an amount of 0 to 10 wt% (0.01 wt%, 0.1 wt%, 0.4 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3.5 wt%, 5 wt%, 8 wt%), preferably 0.5 to 3 wt%;

component g) is used in an amount of 0 to 15 wt.% (0.01 wt.%, 0.1 wt.%, 1 wt.%, 2 wt.%, 5 wt.%, 7 wt.%, 10 wt.%, 12 wt.%), preferably 0 to 8 wt.%.

Preferably, the polyurethane or polyurethane-urea comprises a structural unit shown as a formula (I):

wherein R is selected from the group consisting of residues of component a) after removal of NCO-reactive functional groups. For example, R may be a residue obtained by removing an NCO-reactive functional group from a compound such as N-aminoethylpiperazine, N-hydroxyethylpiperazine, N-dimethyldiethylenetriamine, N-methyldiethanolamine, N-ethyldiethanolamine, 1, 4-bis (aminopropyl) piperazine, N-methylpiperazine, N-ethylpiperazine or N, N-dimethylethanolamine. That is, these residues contain a tertiary amine group.

Preferably, the NCO-reactive functional group is selected from primary amino groups (-NH)₂) One or more of a secondary amino group (-NH-), and a hydroxyl group (-OH).

Preferably, the component a) is selected from one or more of N-aminoethylpiperazine, N-hydroxyethylpiperazine, N-dimethyldipropylenetriamine, N-methyldiethanolamine, N-ethyldiethanolamine, 1, 4-bis (aminopropyl) piperazine, N-methylpiperazine, N-ethylpiperazine and N, N-dimethylethanolamine, more preferably from one or more of N-aminoethylpiperazine, N-hydroxyethylpiperazine, N-dimethyldipropylenetriamine, N-methyldiethanolamine, N-ethyldiethanolamine and 1, 4-bis (aminopropyl) piperazine.

Suitable polyester polyols in component b) may be linear polyester diols or slightly branched polyester diols (containing small amounts of polyester polyols with a functionality of more than 3), for example, obtainable by dehydration and condensation of carboxylic acids or anhydrides, such as aliphatic dicarboxylic or polycarboxylic acids, cycloaliphatic dicarboxylic or polycarboxylic acids, aromatic dicarboxylic or polycarboxylic acids, or the corresponding anhydrides thereof, and the like, with polyols by known means. Examples of carboxylic acids or anhydrides described herein include, but are not limited to, succinic acid, methylsuccinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexanedicarboxylic acid, maleic acid, fumaric acid, malonic acid, trimellitic acid, phthalic anhydride, trimellitic anhydride, succinic anhydride, or mixtures thereof. Examples of the polyhydric alcohol described herein include, but are not limited to, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1, 2-propanediol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, 1, 3-propanediol, 1, 4-butanediol, 1, 3-butanediol, 2, 3-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 2-dimethyl-1, 3-propanediol, 1, 4-dihydroxycyclohexane, 1, 4-dimethylolcyclohexane, 1, 8-octanediol, 1, 10-decanediol, 1, 12-dodecanediol, or a mixture thereof. Optionally, a polyol having a higher functionality, such as trimethylolpropane, glycerol or pentaerythritol, may be added during the preparation of the polyester polyol.

The polyester polyols may also be homopolymers or copolymers of lactones, which may be obtained by ring-opening reaction of a lactone or a mixture of lactones with suitable diols and/or higher functional low molecular weight polyols. Suitable examples of the lactones described herein include, but are not limited to, butyrolactone, epsilon-caprolactone, methyl-epsilon-caprolactone and mixtures thereof; as the polyhydric alcohol, 1, 4-butanediol, 1, 6-hexanediol, 2-dimethyl-1, 3-propanediol and a mixture thereof are preferably used.

In some examples, the component b) is selected from linear polyester diols having a number average molecular weight of 400 to 5000 and/or slightly branched polyester diols having a number average molecular weight of 400 to 5000.

In some examples, component c) is selected from diisocyanates and/or polyisocyanates, preferably diisocyanates (of the formula Y (NCO)₂). In the structural formula, Y represents a divalent aliphatic hydrocarbon group having 4 to 12 carbon atoms, a divalent alicyclic hydrocarbon group having 6 to 15 carbon atoms, a divalent aromatic hydrocarbon group having 6 to 15 carbon atoms or a divalent araliphatic hydrocarbon group having 7 to 15 carbon atoms.

In addition to these simple diisocyanates, polyisocyanates having a functionality of more than 2 isocyanate groups per molecule are also suitable. For example, a polyisocyanate obtained by modification of a simple aliphatic diisocyanate, alicyclic diisocyanate, araliphatic diisocyanate or aromatic diisocyanate (for example, a polyisocyanate obtained by modification of a carbodiimide group, allophanate group, isocyanurate group, urethane group or biuret group), or a polyisocyanate synthesized from at least two diisocyanates (a synthetic polyisocyanate having a uretdione, isocyanurate, urethane, allophanate, biuret, carbodiimide, iminooxadiazinedione or oxadiazinetrione structure).

The diisocyanate in component c) may be aliphatic and cycloaliphatic diisocyanates, for example hexamethylene diisocyanate, 1, 4-cyclohexane diisocyanate, isophorone diisocyanate, 4 '-dicyclohexylmethane diisocyanate, 4' -dicyclohexylpropane diisocyanate and mixtures thereof. In a preferred embodiment, the diisocyanate is selected from one or more of tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 1, 4-cyclohexane diisocyanate, isophorone diisocyanate, 4' -dicyclohexylmethane diisocyanate, 4' -dicyclohexylpropane diisocyanate, 1, 4-phenylene diisocyanate, 2, 4-toluene diisocyanate, 2, 6-toluene diisocyanate, 4' -diphenylmethane diisocyanate, 2' -diphenylmethane diisocyanate, 2,4' -diphenylmethane diisocyanate, tetramethylxylylene diisocyanate, and p-xylylene diisocyanate; more preferably one or more selected from the group consisting of 1, 4-cyclohexane diisocyanate, isophorone diisocyanate and 4,4' -dicyclohexylmethane diisocyanate.

In some preferred embodiments, the component c) is a mixture of hexamethylene diisocyanate and isophorone diisocyanate, or a mixture of hexamethylene diisocyanate and 4,4' -dicyclohexylmethane diisocyanate. Wherein the mass ratio of hexamethylene diisocyanate to isophorone diisocyanate is 1-50: 1, preferably 3-10: 1; the mass ratio of the hexamethylene diisocyanate to the 4,4' -dicyclohexylmethane diisocyanate is 1-50: 1, preferably 3-10: 1.

In component d) of the present invention, the potentially ionic groups contained are functional groups having covalent bonds. By adding a neutralizing agent to the reaction system, the latent ionic group is easily converted into a corresponding salt as the pH of the solution thereof changes. Preferred potentially ionic groups are acid groups selected from carboxyl-COOH and/or sulfonic-SO₃H。

The ionic groups include carboxylate-COO-and/or sulfonate-SO₃-。

Containing NCO-reactive groups selected from hydroxyl (-COOH) and/or amino (e.g., -NH)₂、-NH-)。

If compounds containing potentially ionic groups are used as component d), the neutralizing agent can be added before, during or after the dispersion of the NCO-terminated polyurethane prepolymers obtained after the end of the prepolymerization, in order to neutralize the potentially ionic groups. The amount of neutralizing agent added is such that some or all of the potentially ionic groups are ionic groups. Suitable neutralizing agents are, for example, one or more of primary amines, secondary amines, tertiary amines, alkali metal compounds and alkaline earth metal compounds; examples of suitable neutralizing agents include, but are not limited to, one or more of ammonia, ethanolamine, diethanolamine, triethanolamine, dimethylethanolamine, 2-amino-2-methyl-1-propanol, morpholine, N-methylmorpholine, dimethylisopropylamine, N-methyldiethanolamine, triethylamine, dimethylcyclohexylamine, ethyldiisopropylamine, sodium hydroxide, potassium hydroxide, lithium hydroxide, and calcium hydroxide. In general, sufficient neutralizing agent is added such that the degree of neutralization is at least 50%, preferably at least 75%, and not more than 150%, based on the acid groups introduced. When the degree of neutralization exceeds 100%, free neutralized amine is present in addition to 100% ionic salt groups. The degree of neutralization is particularly preferably 95 to 110%.

When a hydrophilic compound having a nonionic group is used as the component d), examples of the hydrophilic compound having a nonionic group include, but are not limited to, polyether glycols, such as homopolymers of styrene oxide, copolymers of styrene oxide or graft products of styrene oxide, homopolymers of ethylene oxide, copolymers of ethylene oxide or graft products of ethylene oxide, homopolymers of propylene oxide, copolymers of propylene oxide or graft products of propylene oxide, homopolymers of tetrahydrofuran, copolymers of tetrahydrofuran or graft products of tetrahydrofuran, homopolymers of butylene oxide, copolymers of butylene oxide or graft products of butylene oxide, homopolymers of epichlorohydrin, copolymers of epichlorohydrin or graft products of epichlorohydrin, dehydration condensation products of polyols or mixtures thereof, and polyether diols obtained by alkoxylation of diols, diamines and monoalcohols. Wherein the number of ethylene oxide in each molecule of the hydrophilic compound containing a nonionic group is 4 to 200, preferably 12 to 75.

The hydrophilic compound containing nonionic groups can also be a multifunctional polyethoxy ether, such as pentaerythritol, sugar, or the like, as a starter, and one or both of propylene oxide and ethylene oxide as a polymerization unit, preferably ethylene oxide. Wherein, the number of the ethylene oxide in each molecule is 4-200, preferably 12-75.

In some examples, the component d) is selected from one or more of hydrophilic compounds containing ionic groups and containing 2 to 3 NCO-reactive functional groups, hydrophilic compounds containing potentially ionic groups and containing 2 to 3 NCO-reactive functional groups, and hydrophilic compounds containing nonionic groups and containing 2 to 3 NCO-reactive functional groups.

In a preferred embodiment, the hydrophilic compound containing an ionic group and 2-3 NCO-reactive functional groups and/or the hydrophilic compound containing a potentially ionic group and 2-3 NCO-reactive functional groups is selected from one or more of dihydroxy carboxylic acids and salts thereof, trihydroxy carboxylic acids and salts thereof, dihydroxy sulfonic acids and salts thereof, trihydroxy sulfonic acids and salts thereof, diamino sulfonic acids and salts thereof, triamino sulfonic acids and salts thereof, diamino carboxylic acids and salts thereof, and triamino carboxylic acids and salts thereof; more preferably one or more selected from the group consisting of dimethylolacetic acid and its alkali metal and/or ammonium salts, dimethylolpropionic acid and its alkali metal and/or ammonium salts, dimethylolbutyric acid and its alkali metal and/or ammonium salts, dihydroxysuccinic acid and its alkali metal and/or ammonium salts, N- (2-aminoethyl) -2-aminoethanesulfonic acid and its alkali metal and/or ammonium salts, N- (3-aminopropyl) -3-aminopropanesulfonic acid and its alkali metal and/or ammonium salts and N- (2-aminoethyl) -3-aminopropanesulfonic acid and its alkali metal and/or ammonium salts.

In a preferred embodiment, the hydrophilic compound having a nonionic group and 2 to 3 NCO-reactive functional groups is a polyether diol, more preferably a polyether diol having a number average molecular weight of 200 to 8000 and an ethylene oxide number of 4 to 200.

The component d) is more preferably selected from the group consisting of alkali metal salts of N- (2-aminoethyl) -2-aminoethanesulfonic acid, ammonium dimethylolpropionate and Ymer from Perstop^TMOne or more of N-120. For example, component d) is sodium N- (2-aminoethyl) -2-aminoethanesulfonate.

Component e) of the present invention is a compound containing one hydroxyl group or one amino group (e.g., -NH)₂-NH-). Examples of the initiator of the polyethoxy ether include, but are not limited to, saturated monoalcohols (e.g., methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, the isomeric pentanols, hexanols, octanols, nonanols, n-decanol, n-dodecanol, n-tetradecanol, n-hexadecanol, cyclohexanol, hydroxymethylcyclohexane, and 3-ethyl-3-hydroxymethyloxoheterocycle), unsaturated monoalcoholsAnd alcohols (e.g., allyl alcohol, 1-dimethyl-allyl alcohol or oleyl alcohol; aromatic alcohols such as phenol, isomeric cresols or hydroxymethylphenol; araliphatic alcohols such as benzyl alcohol, anisyl alcohol or cinnamyl alcohol), secondary monoamines (e.g., dimethylamine, diethylamine, dipropylamine, diisopropylamine, di-N-butylamine, diisobutylamine, bis (2-ethylhexyl) -amine, N-methyl-and N-ethylcyclohexylamine or dicyclohexylamine), heterocyclic secondary amines (e.g., morpholine, pyrrolidine, piperidineethylpyrazole), etc.; preferred starters are saturated monoalcohols having up to 4 carbon atoms, methanol being particularly preferred as starter. The polymerized units of the polyethoxy ether are propylene oxide and/or ethylene oxide, preferably ethylene oxide. Wherein the number of ethylene oxide in each polyethoxy ether molecule is 4-200, preferably 12-75.

In some examples, the component e) is selected from monofunctional polyethoxy ethers having a number average molecular weight of 200 to 8000 and an ethylene oxide number of 4 to 200, preferably from polyethylene glycol monomethyl ethers having a number average molecular weight of 500 to 3000 and an ethylene oxide number of 12 to 75.

The structural formula of the polyethylene glycol monomethyl ether with the average molecular weight of 500-3000 and the ethylene oxide number of 12-75 is shown as the formula (II):

wherein n is 12 to 75.

In component f), the NCO-reactive functional groups are selected from hydroxyl, primary amino (-NH)₂) And a secondary amino group (-NH-). In some examples, when component f) is a compound containing 2 to 3 NCO-reactive functional groups, at least one of the NCO-reactive functional groups is a primary or secondary amino group. Component f), for example, may be selected from aliphatic primary or secondary monoamines, cycloaliphatic primary or secondary monoamines (e.g., ethylamine, diethylamine, isopropylamine, butylamine, cyclohexylamine); it may also be an aminoalcohol, i.e., a compound having an amino group and a hydroxyl group in the molecule (e.g., ethanolamine, N-methylethanolamine, diethanolamine, diisopropanolamine, 1, 3-diamino-2-propanol, N- (2-hydroxyethyl) ethylenediamine, N-bis (2-hydroxyethyl) ethylenediamine or 2-propanolamine); also possible are diamines and triamines, for example 1, 2-ethylenediamine, 1, 6-hexamethylenediamine, 1-amino-3, 3, 5-trimethyl-5-aminomethylcyclohexane (isophoronediamine), piperazine, 1, 4-diaminocyclohexane, bis- (4-aminocyclohexyl) methane or diethylenetriamine. Also special amines, such as adipic acid dihydrazide, hydrazine, are possible. Mixtures of the above compounds may also be used. In a preferred embodiment, the component f) is selected from one or more of the group consisting of aliphatic primary monoamines, aliphatic secondary monoamines, cycloaliphatic primary monoamines, cycloaliphatic secondary monoamines, aminoalcohols, aliphatic diamines, cycloaliphatic diamines, aliphatic triamines, cycloaliphatic triamines and hydrazines, preferably from one or more of the group consisting of isophoronediamine, N- (2-hydroxyethyl) ethylenediamine and 1, 6-hexamethylenediamine.

Component f) may act as a chain extender to reach higher molecular weights or as a monofunctional compound to limit molecular weight; or optionally also other reactive groups, such as free hydroxyl groups, are introduced as further crosslinking points.

Component g) may be a blocking agent customary in the isocyanate sector (which can be removed at relatively high temperatures), for example butanone oxime, dimethylpyrazole, caprolactam, malonic esters, triazole, dimethyltriazole, tert-butylbenzylamine, cyclopentanone carboxyethyl ester; and unsaturated compounds containing a polymerization-reactive group, such as hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, pentaerythritol triacrylate. Blocking agents in the isocyanate field are those which are used to block monofunctional active hydrogen-containing reactive isocyanates.

In a preferred embodiment, the component g) is selected from one or more of butanone oxime, dimethylpyrazole, caprolactam, malonic acid esters, triazole, dimethyltriazole, tert-butylbenzylamine, cyclopentanone carboxyethyl ester, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate and pentaerythritol triacrylate.

According to the aqueous polyurethane or polyurethane-urea dispersion provided by the invention, in some examples, the aqueous polyurethane or polyurethane-urea dispersion has a solid content of 15-70 wt%, preferably 30-60 wt%.

In some examples, the aqueous dispersion of polyurethane or polyurethane-urea has an average particle size of 20 to 750nm, preferably 50 to 450 nm.

Preferably, the pH value of the aqueous dispersion of polyurethane or polyurethane-urea is 7.5-11, more preferably 7.5-10, and even more preferably 7.5-8.5. The pH level is in positive correlation with the content of tertiary amine groups in the aqueous dispersion.

In another aspect of the present invention, there is provided a process for the preparation of an aqueous dispersion of a polyurethane or polyurethane-urea as described above, comprising the steps of:

mixing the component b), the component c), the component e) and an optional component g) in proportion, and then carrying out polymerization reaction to form an isocyanate-terminated polyurethane prepolymer; carrying out chain extension reaction on the obtained polyurethane prepolymer and the component d) and optional component f), and then dispersing in water or adding water into a mixture obtained after the chain extension reaction for dispersion to obtain a water dispersion of polyurethane or polyurethane-urea; wherein component d) is a hydrophilic compound containing ionic or non-ionic groups and containing 2 to 3 NCO-reactive functional groups; during the reaction process, the component a) can be added into the reaction system at any stage for reaction;

or, mixing the component b), the component c), the component d), the component e) and the optional component g) according to the proportion, and then carrying out polymerization reaction to form the isocyanate-terminated polyurethane prepolymer; neutralizing the obtained polyurethane prepolymer with a neutralizing agent, dispersing in water or adding water into a mixture obtained after neutralization, and adding the component a) for further reaction before, during or after dispersion to obtain a polyurethane or polyurethane-urea aqueous dispersion; wherein the component d) is a hydrophilic compound containing potentially ionic groups and containing 2 to 3 NCO-reactive functional groups.

In the preparation method of the invention, after the component a) is added into the system, neutralization reaction is not carried out, so that the prepared polyurethane or polyurethane-urea contains tertiary amine groups.

According to the process for the preparation of the aqueous dispersions of polyurethanes or polyurethane-ureas provided by the invention, the system can, in some cases, be diluted by adding a solvent, the solvent being removed partly or completely by a distillation operation during or after the dispersion. For example, a water-miscible solvent inert to isocyanate groups may optionally be added for dilution during the reaction. Suitable solvents may be one or more of acetone, methyl isobutyl ketone, butanone, tetrahydrofuran, dioxane, acetonitrile, dipropylene glycol dimethyl ether, and 1-methyl-2-pyrrolidone; they can be added not only at the beginning of the preparation but also during or after the end of the polymerization. It may also be added batchwise. The solvent is preferably acetone and butanone, more preferably acetone. The solvent optionally used, for example acetone, is distilled off during and/or after the dispersion.

The preparation process can be carried out in one or more stages in homogeneous phase or, in the case of a multistage reaction, partly in dispersed phase. The complete or partial polymerization is followed by a dispersing, emulsifying or dissolving step. Optionally, the subsequent polyaddition or modification can be carried out further in the disperse phase.

In some examples, component b), component c), component e), and optionally component g) are mixed in a one or more step reaction and then polymerized to form an isocyanate-terminated polyurethane prepolymer; the resulting prepolymer is reacted in one or two stages with component a), component d) and optionally component f), and the product obtained is then dispersed with water to give an aqueous polyurethane or polyurethane-urea dispersion.

In some examples, the polymerization is carried out by placing all or part of components b), d), e) and optionally g) into a reactor, optionally diluting with a water-miscible solvent which is inert towards isocyanate groups, and then metering in component c) at a temperature of between room temperature and 120 ℃ for the prepolymerization to give an isocyanate-terminated polyurethane prepolymer. This reaction can be carried out in a single stage or in multiple stages.

The multistage reaction may be, for example: component b), component c), component e) are placed in the reactor beforehand and component g) is added after reaction with a portion of component c), which can then be reacted with a further portion of component c) still present, component a) being added at any stage.

During the course of the reaction, the degree of conversion is generally monitored by tracking the NCO content of the reaction mixture. For this purpose, spectroscopic measurements (for example determination of infrared or near-infrared spectra, refractive index) and chemopotentiometric titrations (for example chemical titrations via removal of a sample) can be used, preference being given to chemopotentiometric titrations.

Optionally, a catalyst may also be added during the reaction. Conventional catalysts may be those known to one of ordinary skill in the art for accelerating the reaction of-NCO with-OH. For example, one or more of triethylamine, 1, 4-diazabicyclo- [2,2,2] -octane, dibutyltin oxide, tin dioctoate, dibutyltin dilaurate, tin bis- (2-ethylhexanoate), bismuth neodecanoate, and bismuth 2-ethylhexanoate. Preferably bismuth neodecanoate or bismuth 2-ethylhexanoate, more preferably bismuth neodecanoate.

In the reaction process, the temperature in the chain extension reaction stage is usually 10-100 ℃, and preferably 25-60 ℃.

In some preferred embodiments, the aqueous polyurethane or polyurethane-urea dispersion is prepared by: the component b), the component c), the component e) and an optional solvent are added in advance according to the proportion, mixed and heated to 50-100 ℃, and stirred simultaneously. The reaction mixture is stirred at 40 to 150 ℃ by means of an exothermic reaction until the theoretical isocyanate content has been reached or slightly below, optional component g) is added and the reaction is continued until the theoretical isocyanate content has been reached or slightly below. Then diluting the mixture to a solid content of 25-95 wt%, preferably 40-80 wt%, by adding a solvent, and then respectively adding the component a), the component d) and optionally the component f) diluted by the solvent at 10-100 ℃, preferably 25-60 ℃, so as to carry out chain extension. After a reaction time of 2 to 60 minutes, the dispersion is carried out by adding distilled water or by transferring the mixture into previously placed distilled water, and during or after the dispersion step, the solvent used is distilled off in whole or in part and then some auxiliaries (for example, the emulsifier Tween 20) are added. The polymerization reaction may optionally be supplemented with a catalyst (e.g., bismuth neodecanoate).

All processes known from the prior art, such as emulsifier shear, acetone, prepolymer mixing, melt emulsification, ketimine and solid spontaneous dispersion processes or their derivations, can be used for the preparation of the aqueous polyurethane or polyurethane-urea dispersions described in the present invention. A review of these methods can be found in Methoden der organischen Chemie (Houben-Weyl, Erweiterung-und)

zur 4. autoflage, volume E20, h.bartl and j.falbe, Stuttgart, New York, Thieme 1987, page 1671-. Preferably, a melt emulsification method, a prepolymer mixing method, and an acetone method are used. The acetone process is particularly preferred.

In a further aspect of the invention there is provided the use of an aqueous polyurethane or polyurethane-urea dispersion as described above or obtained by the process as described above in an adhesive.

The aqueous polyurethane or polyurethane-urea dispersions prepared according to the invention can be used alone or together with known auxiliary substances and additives (in coating and adhesive technology). Customary auxiliary substances and additives, for example emulsifiers, light stabilizers (e.g. UV absorbers and sterically Hindered Amines (HALS)), antioxidants, fillers, antisettling agents, defoamers, wetting agents, flow control agents, reactive diluents, plasticizers, neutralizing agents, catalysts, auxiliary solvents, thickeners, pigments, dyes, matting agents, adhesion promoters (Tackifier) and the like.

Auxiliary substances and additives can be added before or after the polymerization. It is, of course, also possible to add auxiliary substances and additives after dispersion.

The aqueous dispersions of the polyurethanes or polyurethane-ureas prepared can also be used in admixture with other aqueous or solvent-containing oligomers or polymers to improve the storage properties of the blended emulsions. These oligomers or polymers are, for example, polyvinyl esters, polyvinyl ethers, polyvinyl alcohols, polyethylene, polystyrene, polybutadiene, polyvinyl chloride, polyurethanes, polyurethane-polyureas, polyurethane-polyacrylates, polyesters, polyacrylates. The compatibility of such mixtures needs to be tested in each case with simple preliminary tests.

The aqueous dispersions of polyurethanes or polyurethane-ureas prepared and the adhesives or binder compositions based thereon are suitable for bonding any substrates. Such substrates are, for example, all types of metals, alloys, wood-based materials, particle board, MDF board, ceramics, stone, concrete, asphalt, hard fibers, glass fibers, carbon nanotubes, porcelain, leather, textiles, inorganic materials, and the like. They are likewise suitable for bonding rubber materials (e.g. natural rubber and synthetic rubber), various plastics (e.g. polyurethane, polyvinyl acetate, polyvinyl chloride, in particular polyvinyl chloride with plasticizers). They are likewise suitable for bonding thermoplastics, for example ABS (acrylic-butadiene-styrene), PC (polycarbonate), polyolefin plastics and mixtures thereof.

The adhesives of the aqueous dispersions of polyurethanes or polyurethane-ureas prepared are likewise suitable for use in articles made therefrom. Examples of such articles include, but are not limited to, shoe soles, such as those based on polyvinyl chloride (especially polyvinyl chloride with plasticizers), those based on polyethylene vinyl acetate or polyurethane elastomer foams, and the bonding of uppers made of leather or imitation leather. It is also particularly suitable for bonding films based on polyvinyl chloride or polyvinyl chloride containing plasticizers to wood.

Compared with the prior art, the technical scheme of the invention has the following beneficial effects:

in the aqueous dispersions obtained according to the invention, the side chains or the main chain of the polyurethane or polyurethane-urea have segments (i.e.tertiary amine groups) which component a) contains. In the storage process of the aqueous dispersion, the tertiary amine group has stronger alkalinity, so that acidic substances in a system can be eliminated, the catalytic action of the acidic substances on the ester polymer is further eliminated, and the aqueous dispersion can be stably stored. In the storage process, the tertiary amine group can eliminate acid substances in a system, greatly reduce the hydrolysis rate of the ester polymer, obviously improve the hydrolysis resistance of the adhesive prepared from the dispersion and simultaneously keep better bonding strength and heat resistance of the adhesive.

Compared with the existing aqueous polyurethane-polyurea dispersion, the aqueous dispersion of the invention has excellent hydrolysis resistance when being used as an adhesive, the existing aqueous polyurethane-polyurea dispersion resists hydrolysis within 6-10 days (storage at 70 ℃), and the hydrolysis resistance of the aqueous dispersion of the invention can reach 15-20 days (storage at 70 ℃).

The existing waterborne polyurethane-polyurea dispersoid needs to be added with cross-linking agents such as isocyanate or carbodiimide and the like before use, needs to be mixed according to the proportion before construction, has complex operation, needs to use the prepared adhesive within the specified time, has short opening time, and has obvious effect of reducing the initial viscosity of the adhesive by adding the cross-linking agent; the aqueous dispersion can meet the performance requirement without adding crosslinking agents such as isocyanate or carbodiimide, can be used as a single-component adhesive product, is simple to operate and long in opening time, and greatly improves the construction efficiency.

Detailed Description

In order that the technical features and contents of the present invention can be understood in detail, preferred embodiments of the present invention will be described in more detail below. While the preferred embodiments of the present invention have been described in the examples, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein.

< sources of raw materials >

Polyester I: poly (1, 4-butylene adipate) glycol with an OH number of 56mg KOH/g (C

WHP-204, Wanhua chemical),

polyester II: polyester diols composed of 1, 6-hexanediol, neopentyl glycol and adipic acid, with OH numbers of 74mg KOH/g (

WHP-1556, Wanhua chemical),

polyesterIII: poly (1, 4-butylene adipate) glycol with an OH number of 112mg KOH/g (A)

WHP-104, Wanhua chemical),

and (2) polyester IV: 1, 6-hexanediol poly (phthalate), OH 56mg KOH/g (PH-56, Spilan),

polyester V: polycarbonate diol having an OH value of 56mg KOH/g (PCDL T5652, Asahi Kasei Co.);

isocyanate I: hexamethylene diisocyanate (

HDI, wanhua chemistry),

isocyanate II: isophorone diisocyanate (

IPDI, wanhua chemistry);

polyether I: monofunctional polyethoxyethers having an average molecular weight of 1200g/mol (MPEG1200, LOTTE CHEM),

polyether II: monofunctional polyethoxyethers having an average molecular weight of 520g/mol (MPEG520, LOTTE CHEM);

bismuth neodecanoate (

8108，Shepferd)；

Sodium N- (2-aminoethyl) -2-aminoethanesulfonate (Vestamin A95, winning);

n-aminoethyl piperazine (Jinjinle-Hua science),

n, N-dimethyl dipropylenetriamine (constant-landscape chemical industry),

n-ethyldiethanolamine (potentiostatic chemical);

hydroxyethylethylenediamine, i.e. N- (2-hydroxyethyl) ethylenediamine (Yangzobaff),

isophoronediamine (warfarin chemical);

butanone oxime (jinjinjinglehua science);

emulsifier Tween 20 (Shanghai Pont scene industry).

< detection method >

Determination of the average particle diameter of the aqueous dispersion: the test was carried out using a malvern particle sizer Nano S90.

Example 1

210g of dehydrated polyester I, 29g of isocyanate I, 2g of dehydrated polyether I, 24g of acetone and 0.04g of bismuth neodecanoate were placed in a 1L four-necked round-bottomed flask equipped with a nitrogen inlet and outlet, and the mixture was stirred at 80-90 ℃ until the NCO reached 2.09%. The resulting prepolymer was dissolved in 400g of acetone and cooled to 50 ℃.35g of an aqueous solution in which 4.63g N- (2-aminoethyl) -2-aminoethanesulfonic acid sodium salt, 2.47g N-aminoethylpiperazine and 1g of hydroxyethylethylenediamine were dissolved was added to an acetone solution in which the prepolymer was dissolved, and the mixture was vigorously stirred. Stirring was carried out for 20min, and the mixture was then dispersed by adding 250g of water. After separation of the acetone by distillation, 4g of emulsifier Tween 20 were added. That is, a solvent-free aqueous polyurethane-polyurea dispersion was obtained having a solids content of 50% by weight and an average particle diameter of 180nm as determined by laser correlation in the dispersed phase, the pH of which was determined to be 8.0.

Example 2

150g of dehydrated polyester I, 53g of dehydrated polyester II, 29g of isocyanate I, 24g of acetone, 0.04g of bismuth neodecanoate and 2g of dehydrated polyether II are introduced into a 1L four-neck round-bottomed flask equipped with a nitrogen inlet and outlet, and the mixture is stirred at 80 to 90 ℃ until the NCO reaches 1.94%. The prepolymer obtained was dissolved in 380g of acetone and cooled to 50 ℃. 30g of an aqueous solution containing 2g N- (2-aminoethyl) -2-aminoethanesulfonic acid sodium salt, 4g N, N-dimethyldipropylenetriamine and 1g of hydroxyethylethylenediamine dissolved therein was added to an acetone solution containing the prepolymer dissolved therein, and the mixture was vigorously stirred. Stirred for 20min, then the mixture was dispersed by adding 210g of water. After separation of the acetone by distillation, 4g of emulsifier Tween 20 were added. That is, a solvent-free aqueous polyurethane-polyurea dispersion was obtained having a solids content of 55% by weight and an average particle diameter of 220nm as determined by laser correlation in the dispersed phase, the pH of which was determined to be 8.2.

Example 3

80g of dehydrated polyester I, 33g of dehydrated polyester III, 23g of dehydrated polyester IV, 2g of dehydrated polyether I, 22g of isocyanate I, 18g of acetone and 0.04g of bismuth neodecanoate were placed in a 1L four-neck round-bottomed flask equipped with a nitrogen inlet and outlet, and the mixture was stirred at 80-90 ℃ until the NCO reached 2.13%. The resulting prepolymer was dissolved in 309g of acetone and cooled to 50 ℃.35g of an aqueous solution in which 4.6g N- (2-aminoethyl) -2-aminoethanesulfonic acid sodium salt, 1.5g N, N-dimethyldipropylenetriamine and 1g of hydroxyethylethylenediamine were dissolved was added to an acetone solution in which the prepolymer was dissolved, and the mixture was vigorously stirred. Stirred for 20min, then the mixture was dispersed by adding 224g of water. After separation of the acetone by distillation, 4g of emulsifier Tween 20 were added. That is, a solvent-free aqueous polyurethane-polyurea dispersion was obtained having a solids content of 45% by weight and an average particle diameter of 150nm as determined by laser correlation in the dispersed phase, the pH of which was determined to be 7.8.

Example 4

60g of dehydrated polyester I, 77g of dehydrated polyester II, 35g of dehydrated polyester III, 29g of isocyanate I, 2g of dehydrated polyether I, 25g of acetone and 0.04g of bismuth neodecanoate were placed in a 1L four-neck round-bottomed flask equipped with a nitrogen inlet and outlet and the mixture was stirred at 80-90 ℃ until the NCO reached 2.05%. The resulting prepolymer was dissolved in 405g of acetone and cooled to 50 ℃.35g of an aqueous solution in which 4g N- (2-aminoethyl) -2-aminoethanesulfonic acid sodium salt, 1g of isophorone diamine, 1.5g N-aminoethyl piperazine, and 1g of hydroxyethyl ethylenediamine were dissolved was added to an acetone solution in which the prepolymer was dissolved, and the mixture was vigorously stirred. Stirring was carried out for 20min, and then the mixture was dispersed by adding 238g of water. After separation of the acetone by distillation, 4g of emulsifier Tween 20 were added. That is, a solvent-free aqueous polyurethane-polyurea dispersion was obtained having a solids content of 50% by weight and an average particle diameter of 180nm as determined by laser correlation in the dispersed phase, the pH of which was determined to be 7.7.

Example 5

120g of dehydrated polyester I, 72g of dehydrated polyester II, 29g of isocyanate I and 2g of dehydrated polyether I were placed in a 1L four-necked round-bottomed flask equipped with a nitrogen inlet and outlet, and the mixture was stirred at 80 to 90 ℃ until the NCO reached 2.15%. The resulting prepolymer was dissolved in 424g of acetone and cooled to 50 ℃.35g of an aqueous solution in which 5g N- (2-aminoethyl) -2-aminoethanesulfonic acid sodium salt, 2g of isophorone diamine, 1.2g N, N-dimethyldipropylenetriamine and 1g of hydroxyethyl ethylenediamine were dissolved was added to an acetone solution in which the prepolymer was dissolved, and the mixture was vigorously stirred. Stir 20min, then disperse the mixture by adding 558g of water. After separation of the acetone by distillation, 4g of emulsifier Tween 20 were added. That is, a solvent-free aqueous polyurethane-polyurea dispersion was obtained having a solids content of 30% by weight and an average particle diameter of 164nm, determined by laser correlation in the dispersed phase, which was determined to have a pH of 7.7.

Example 6

210g of dehydrated polyester I, 43g of isocyanate I and 2g of dehydrated polyether I were placed in a 1L four-necked round-bottomed flask equipped with a nitrogen inlet and outlet, the mixture was stirred at 80 to 90 ℃ until the NCO reached 4.98%, and then 15.2g of butanone oxime were added at 50 ℃ until the NCO had decreased to 2.20%. The resulting prepolymer was dissolved in 450g of acetone and cooled to 50 ℃. An aqueous solution of 35g in which 5g N- (2-aminoethyl) -2-aminoethanesulfonic acid sodium salt, 4.5g N-aminoethylpiperazine and 1g of hydroxyethylethylenediamine were dissolved was added to an acetone solution in which the prepolymer was dissolved, and the mixture was vigorously stirred. Stirred for 20min, then the mixture was dispersed by adding 253g of water. After separation of the acetone by distillation, 4g of emulsifier Tween 20 were added. That is, a solvent-free aqueous polyurethane-polyurea dispersion was obtained having a solids content of 50% by weight and an average particle diameter of 180nm as determined by laser correlation in the dispersed phase, the pH of which was determined to be 8.3.

Example 7

210g of dehydrated polyester I, 20g of isocyanate I, 11.1g of isocyanate II, 2g of dehydrated polyether I, 24g of acetone and 0.04g of bismuth neodecanoate were placed in a 1L four-necked round-bottomed flask equipped with a nitrogen inlet and outlet and the mixture was stirred at 80-90 ℃ until the NCO reached 1.98%. The resulting prepolymer was dissolved in 405g of acetone and cooled to 50 ℃.35g of an aqueous solution in which 4.8g N- (2-aminoethyl) -2-aminoethanesulfonic acid sodium salt, 3g N-aminoethylpiperazine and 1g of hydroxyethylethylenediamine were dissolved was added to an acetone solution in which the prepolymer was dissolved, and the mixture was vigorously stirred. Stirring was carried out for 20min, and then the mixture was dispersed by adding 241g of water. After separation of the acetone by distillation, 4g of emulsifier Tween 20 were added. That is, a solvent-free aqueous polyurethane-polyurea dispersion was obtained having a solids content of 50% by weight and an average particle diameter of 176nm in the dispersed phase, determined by laser correlation, the pH of which was 8.

Example 8

170g of dehydrated polyester I, 29g of isocyanate I, 4g N-hydroxyethylpiperazine, 2g of dehydrated polyether I, 24g of acetone and 0.02g of bismuth neodecanoate were placed in a 1L four-necked round-bottomed flask equipped with a nitrogen inlet and outlet, and the mixture was stirred at 80 to 90 ℃ until the NCO reached 2.05%. The resulting prepolymer was dissolved in 419g of acetone and cooled to 50 ℃. An aqueous solution of 35g in which 4.5g N- (2-aminoethyl) -2-aminoethanesulfonic acid sodium salt, 2.5g of isophoronediamine, and 1g of hydroxyethylethylenediamine were dissolved was added to an acetone solution in which the prepolymer was dissolved, and the mixture was vigorously stirred. Stirring was carried out for 20min, and then the mixture was dispersed by adding 300g of water. After separation of the acetone by distillation, 4g of emulsifier Tween 20 were added. That is, a solvent-free aqueous polyurethane-polyurea dispersion was obtained having a solids content of 40% by weight and an average particle diameter of 195nm as determined by laser correlation in the dispersed phase, the pH of which was determined to be 7.9.

Example 9

210g of dehydrated polyester I, 32g of isocyanate I, 3g N-ethyldiethanolamine, 2g of dehydrated polyether I, 24g of acetone, 0.04g of bismuth neodecanoate were placed in a 1L four-necked round-bottomed flask equipped with a nitrogen inlet and outlet, and the mixture was stirred at 80-90 ℃ until the NCO reached 1.92%. The resulting prepolymer was dissolved in 413g of acetone and cooled to 50 ℃. An aqueous solution of 35g in which 4.63g N- (2-aminoethyl) -2-aminoethanesulfonic acid sodium salt and 1g of hydroxyethylethylenediamine were dissolved was added to an acetone solution in which the prepolymer was dissolved, and the mixture was vigorously stirred. Stirring was carried out for 20min, and then the mixture was dispersed by adding 300g of water. After separation of the acetone by distillation, 4g of emulsifier Tween 20 were added. That is, a solvent-free aqueous polyurethane-polyurea dispersion was obtained having a solids content of 40% by weight and an average particle diameter of 195nm, determined by laser correlation in the dispersed phase, which was determined to have a pH of 8.

Example 10

190g of dehydrated polyester I, 12g of dehydrated polyester V, 20g of isocyanate I, 11g of isocyanate II, 2g of dehydrated polyether I, 23g of acetone and 0.04g of bismuth neodecanoate were placed in a 1L four-necked round-bottomed flask equipped with a nitrogen inlet and outlet, and the mixture was stirred at 80-90 ℃ until the NCO reached 2.15%. The resulting prepolymer was dissolved in 400g of acetone and cooled to 50 ℃.35g of an aqueous solution in which 4.63g N- (2-aminoethyl) -2-aminoethanesulfonic acid sodium salt, 3.2g N-aminoethylpiperazine and 1g of hydroxyethylethylenediamine were dissolved was added to an acetone solution in which the prepolymer was dissolved, and the mixture was vigorously stirred. Stirring was carried out for 20min, and then the mixture was dispersed by adding 238g of water. After separation of the acetone by distillation, 4g of emulsifier Tween 20 were added. That is, a solvent-free aqueous polyurethane-polyurea dispersion was obtained having a solids content of 50% by weight and an average particle diameter of 165nm in the dispersed phase as determined by laser correlation, the pH value of which was determined to be 8.5.

Example 11

190g of dehydrated polyester I, 20g of dehydrated polyester V, 20g of isocyanate I, 13g of isocyanate II, 2g of dehydrated polyether I, 23g of acetone and 0.04g of bismuth neodecanoate were placed in a 1L four-necked round-bottomed flask equipped with a nitrogen inlet and outlet, and the mixture was stirred at 80-90 ℃ until the NCO reached 2.05%. The resulting prepolymer was dissolved in 400g of acetone and cooled to 50 ℃.35g of an aqueous solution in which 4.63g N- (2-aminoethyl) -2-aminoethanesulfonic acid sodium salt, 3.2g N-aminoethylpiperazine and 1g of hydroxyethylethylenediamine were dissolved was added to an acetone solution in which the prepolymer was dissolved, and the mixture was vigorously stirred. Stirring was carried out for 20min, and then the mixture was dispersed by adding 238g of water. After separation of the acetone by distillation, 4g of emulsifier Tween 20 were added. That is, a solvent-free aqueous polyurethane-polyurea dispersion was obtained having a solids content of 50% by weight and an average particle diameter of 178nm, determined by laser correlation in the dispersed phase, which was determined to have a pH of 8.3.

Example 12

80g of dehydrated polyester I, 120g of dehydrated polyester II, 30g of dehydrated polyester III, 28.35g of isocyanate I, 2g of dehydrated polyether I, 25g of acetone and 0.04g of bismuth neodecanoate were placed in a 1L four-neck round-bottomed flask equipped with a nitrogen inlet and outlet, and the mixture was stirred at 80-90 ℃ until NCO reached 1.92%. The resulting prepolymer was dissolved in 395g of acetone and cooled to 50 ℃.35g of an aqueous solution in which 5g N- (2-aminoethyl) -2-aminoethanesulfonic acid sodium salt, 3g N, N-dimethyldipropylenetriamine and 1g of hydroxyethylethylenediamine were dissolved was added to an acetone solution in which the prepolymer was dissolved, and the mixture was vigorously stirred. Stirring was carried out for 20min, and then the mixture was dispersed by adding 238g of water. After separation of the acetone by distillation, 4g of emulsifier Tween 20 were added. That is, a solvent-free aqueous polyurethane-polyurea dispersion was obtained having a solids content of 50% by weight and an average particle diameter of 185nm, determined by laser correlation in the dispersed phase, which was determined to have a pH of 8.

Example 13

210g of dehydrated polyester I, 20g of isocyanate I, 11.1g of isocyanate II, 2g of dehydrated polyether I, 24g of acetone and 0.04g of bismuth neodecanoate were placed in a 1L four-necked round-bottomed flask equipped with a nitrogen inlet and outlet and the mixture was stirred at 80-90 ℃ until the NCO reached 1.98%. The resulting prepolymer was dissolved in 405g of acetone and cooled to 50 ℃.35g of an aqueous solution in which 4.8g N- (2-aminoethyl) -2-aminoethanesulfonic acid sodium salt, 0.12g N-aminoethylpiperazine and 2.5g of hydroxyethylethylenediamine were dissolved was added to an acetone solution in which the prepolymer was dissolved, and the mixture was vigorously stirred. Stirring was carried out for 20min, and then the mixture was dispersed by adding 241g of water. After separation of the acetone by distillation, 4g of emulsifier Tween 20 were added. That is, a solvent-free aqueous polyurethane-polyurea dispersion was obtained having a solids content of 50% by weight and an average particle diameter of 176nm in the dispersed phase as determined by laser correlation, the pH value of which was determined to be 7.2.

Example 14

180g of dehydrated polyester I, 20g of isocyanate I, 11.1g of isocyanate II, 7g of dehydrated polyether I, 24g of acetone and 0.04g of bismuth neodecanoate were placed in a 1L four-necked round-bottomed flask equipped with a nitrogen inlet and outlet and the mixture was stirred at 80-90 ℃ until the NCO reached 2.5%. The resulting prepolymer was dissolved in 405g of acetone and cooled to 50 ℃.35g of an aqueous solution containing 1g N- (2-aminoethyl) -2-aminoethanesulfonic acid sodium salt and 6.9g N-aminoethylpiperazine dissolved therein was added to an acetone solution containing the prepolymer dissolved therein, and the mixture was vigorously stirred. Stirring was carried out for 20min, and then the mixture was dispersed by adding 241g of water. After separation of the acetone by distillation, 4g of emulsifier Tween 20 were added. That is, a solvent-free aqueous polyurethane-polyurea dispersion was obtained having a solids content of 50% by weight and an average particle diameter of 176nm in the dispersed phase as determined by laser correlation, the pH of which was determined to be 8.9.

Comparative example 1

210g of dehydrated polyester I, 28.35g of isocyanate I, 2g of dehydrated polyether I, 24g of acetone, 0.04g of bismuth neodecanoate were placed in a 1L four-necked round-bottomed flask equipped with a nitrogen inlet and outlet and the mixture was stirred at 80-90 ℃ until the NCO reached 1.72%. The resulting prepolymer was dissolved in 405g of acetone and cooled to 50 ℃. An aqueous solution of 35g in which 5.1g N- (2-aminoethyl) -2-aminoethanesulfonic acid sodium salt, 3.51g of isophoronediamine and 0.86g of hydroxyethylethylenediamine were dissolved was added to an acetone solution in which the prepolymer was dissolved, and the mixture was vigorously stirred. Stirring was carried out for 20min, and then the mixture was dispersed by adding 300g of water. After separation of the acetone by distillation, 4g of emulsifier Tween 20 were added. That is, a solvent-free aqueous polyurethane-polyurea dispersion was obtained having a solids content of 50% by weight and an average particle diameter of 180nm as determined by laser correlation in the dispersed phase, the pH of which was determined to be 7.0.

Comparative example 2

210g of dehydrated polyester I, 20g of isocyanate I, 11.1g of isocyanate II, 2g of dehydrated polyether I, 24g of acetone and 0.04g of bismuth neodecanoate were placed in a 1L four-necked round-bottomed flask equipped with a nitrogen inlet and outlet and the mixture was stirred at 80-90 ℃ until the NCO reached 1.98%. The resulting prepolymer was dissolved in 405g of acetone and cooled to 50 ℃.35g of an aqueous solution in which 4.8g N- (2-aminoethyl) -2-aminoethanesulfonic acid sodium salt, 0.02g N-aminoethylpiperazine and 2.6g of hydroxyethylethylenediamine were dissolved was added to an acetone solution in which the prepolymer was dissolved, and the mixture was vigorously stirred. Stirring was carried out for 20min, and then the mixture was dispersed by adding 241g of water. After separation of the acetone by distillation, 4g of emulsifier Tween 20 were added. That is, a solvent-free aqueous polyurethane-polyurea dispersion was obtained having a solids content of 50% by weight and an average particle diameter of 176nm in the dispersed phase as determined by laser correlation, the pH value of which was determined to be 7.0.

The particle size and pH data of the aqueous polyurethane or polyurethane-urea dispersions obtained in the examples show that we have successfully synthesized PUD dispersions. Since the significant change after the introduction of the segment containing tertiary amine groups in the aqueous polyurethane or polyurethane-urea dispersion is an increase in pH, the pH of the dispersion containing tertiary amine groups being between 7.5 and 8.9, while the pH of the dispersion containing no or very little tertiary amine groups is essentially 7.0.

The content of tertiary amine groups is very low compared to the entire polyurethane system and cannot be characterized by conventional spectroscopy. Since component a) containing tertiary amine groups contains groups capable of reacting with NCO, which are in excess, it is believed that tertiary amine groups can be attached to the polyurethane or polyurethaneurea molecular chain.

Preparation of the adhesive

100g of the aqueous dispersion obtained in each of examples and comparative examples was mixed with 0.05g of BYK024 (Beck chemical), stirred at 500rpm for 5min, then 0.2g of Tego245 (Digao) was added, stirred for 5min, then 0.15g of Vesmody U604 (Van. chemical) was added, and stirred at 600rpm for 10min, to obtain each adhesive corresponding to each of examples and comparative examples.

Preparation and testing of samples for testing

(1) The test specimens were prepared from the composites in table 1:

composite material	Substrate 1	Base material 2
			A	Rubber composition	Rubber composition
B	Canvas	Canvas
			C	PVC	PVC

First, polishing treatment is performed on the base material 1 (rubber) and the base material 2 (rubber). The adhesive thus prepared was then applied thinly using a brush to a 2.5cm wide and 15cm long strip of substrate and dried in an oven at 65 ℃ for 3 minutes, removed and passed through a hot press at 30kg/cm²Pressing for 10 seconds under the condition to obtain the composite material A.

Composite materials B and C were prepared in the same manner as above.

(2) The resulting composite was tested for peel strength

The peel strength was measured with a GOTECH tensile machine at a peel rate of 200 mm/min. Wherein, the initial strength: and after pressing, directly testing the peel strength of the laminated board by a tensile machine. Later strength: after the test piece was left at room temperature for 24 hours, the peel strength was measured. The test results are shown in Table 2.

TABLE 2 Peel Strength of the Adhesives on different substrates

As can be seen from Table 2, the one-component adhesives based on the aqueous polyurethane or polyurethane-urea dispersions obtained according to the invention have comparable initial peel strength and later peel strength, meet the performance requirements, and do not impair normal use, compared to the one-component adhesives obtained from aqueous polyurethane dispersions which do not contain or contain traces (less than 0.02%) of tertiary amine groups (comparative examples 1 and 2).

(3) The resulting composite was tested for heat resistance

Initial heat resistance: the prepared sample was hung with a 500 g weight and placed in an 80 ℃ oven and tested for the length the sample pulled apart in 30 minutes.

And (3) later-stage heat resistance: after the prepared sample was allowed to stand at room temperature for 3 days, a weight of 1 kg was hung and placed in an oven at 70 ℃ to measure the length of the sample pulled apart within 24 hours.

The test results are shown in Table 3.

TABLE 3 Heat resistance of the respective Adhesives on different substrates

As can be seen from Table 3, the one-component adhesives based on the aqueous polyurethane or polyurethane-urea dispersions obtained according to the invention have a significantly improved initial heat resistance and improved later heat resistance compared to the one-component adhesives obtained from polyurethane dispersions which do not contain or contain traces (less than 0.02%) of tertiary amine groups (comparative examples 1 and 2).

(4) Testing of the hydrolysis resistance of the polyurethane dispersions

If a hydrolysis reaction occurs in the system, the molecular weight of the polyurethane or polyurethane urea segment decreases, and the initial heat resistance of the substrate bonded with the aqueous polyurethane or polyurethane urea as an adhesive deteriorates. Therefore, its resistance to hydrolysis is characterized by the initial heat resistance value at high/normal temperature conditions. The lower the initial heat resistance value, the more excellent the hydrolysis resistance.

High temperature (70 ℃) hydrolysis resistance: the aqueous dispersions prepared in each example and comparative example were stored at 70 ℃, sampled after 0 days, 3 days, 6 days, 9 days, 12 days, 15 days, 18 days and 21 days, respectively, and tested for initial heat resistance level of the samples (which were used as adhesives) applied to the rubber substrate. The results of the high temperature hydrolysis resistance test are shown in table 4.

Hydrolysis resistance at ambient temperature (30 ℃): the aqueous dispersions prepared in the present examples and comparative examples were stored at 30 ℃, and sampled after 0 days, 30 days, 60 days, 90 days, 120 days, 150 days, 180 days, and 210 days, respectively, to test the initial heat resistance level of the samples (which were used as an adhesive) coated on the rubber substrate. The results of the room temperature hydrolysis resistance test are shown in Table 5.

TABLE 4 initial heat resistance of the respective adhesives on the rubber substrates after storage at high temperatures

TABLE 5 initial Heat resistance of the respective Adhesives on the rubber substrate after storage at ambient temperature

As is apparent from tables 4 and 5, the one-component adhesives based on the aqueous polyurethane or polyurethane-urea dispersions obtained according to the present invention are significantly higher in both high-temperature (70 ℃ C.) resistance and normal-temperature (e.g., 25 ℃ C.) resistance than the one-component adhesives obtained from the polyurethane dispersions containing no or a trace amount (less than 0.02%) of tertiary amine groups (comparative examples 1 and 2). This is because the side chain or the main chain has a segment (i.e., a segment containing a tertiary amine group) introduced by the component a), which can react with carboxylic acid present in the dispersion system, reducing the concentration of acid in the system, eliminating the catalytic action of carboxylic acid on the hydrolysis of ester groups, and further reducing the hydrolysis of ester bonds in the polyurethane or polyurethane urea polymer; the hydrolysis resistance effect is shown in the initial heat resistance test as follows: the initial heat resistance decreased extremely slowly with the lapse of time. While the polyurethane dispersion obtained in comparative example 1 contains no acid-eliminable structures or groups, irreversible hydrolysis of the ester groups is accelerated by the action of the acidic substances present in the system. The hydrolysis can cause cracking and breaking of macromolecules, and the hydrolysis resistance effect is shown in the aspect of initial heat resistance test as follows: the initial heat resistance rapidly decreases with time. This indicates that the aqueous polyurethane or polyurethane urea dispersion having a segment containing a tertiary amine group in a side chain or a main chain has excellent hydrolysis resistance. In addition, the content of the segment containing a tertiary amine group in the side chain or main chain also affects the hydrolysis resistance, e.g., the adhesive obtained from the polyurethane dispersion of example 10 is optimal in hydrolysis resistance; the polyurethane dispersion of comparative example 2 produced an adhesive with less hydrolysis resistance than the examples.

Having described embodiments of the present invention, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

1. An aqueous dispersion of a hydrolysis-resistant polyurethane or polyurethane-urea, characterized in that the polyurethane or polyurethane-urea contained in the aqueous dispersion is obtained by reacting raw materials comprising:

c) an organic compound having at least two isocyanate groups,

f) optionally, a compound containing 1 to 3 NCO reactive functional groups,

2. The aqueous polyurethane or polyurethane-urea dispersion according to claim 1, wherein the amount of the components is, based on the total weight of the components,

the amount of the component a) is 0.02-5 wt%, preferably 0.05-3 wt%;

the amount of component b) is 5 to 94 wt%, preferably 70 to 90 wt%;

the amount of component c) is 5 to 40 wt%, preferably 8 to 20 wt%;

the amount of component d) is 0.2 to 50 wt%, preferably 1 to 5 wt%;

the amount of the component e) is 0.01 to 20 wt%, preferably 0.5 to 3 wt%;

the amount of the component f) is 0 to 10 wt%, preferably 0.5 to 3 wt%;

the amount of component g) is 0 to 15 wt.%, preferably 0 to 8 wt.%.

3. The aqueous polyurethane or polyurethane-urea dispersion according to claim 1 or 2, wherein the polyurethane or polyurethane-urea comprises structural units according to formula (I):

wherein R is selected from the group consisting of residues of component a) after removal of NCO-reactive functional groups.

4. The aqueous polyurethane or polyurethane-urea dispersion according to any of claims 1-3, characterized in that the NCO-reactive functional groups are selected from one or more of primary amino, secondary amino and hydroxyl groups.

5. The aqueous polyurethane or polyurethane-urea dispersion according to any one of claims 1 to 4,

the component a) is selected from one or more of N-aminoethylpiperazine, N-hydroxyethylpiperazine, N-dimethyldipropylenetriamine, N-methyldiethanolamine, N-ethyldiethanolamine, 1, 4-bis (aminopropyl) piperazine, N-methylpiperazine, N-ethylpiperazine and N, N-dimethylethanolamine, preferably from one or more of N-aminoethylpiperazine, N-hydroxyethylpiperazine, N-dimethyldipropylenetriamine, N-methyldiethanolamine, N-ethyldiethanolamine and 1, 4-bis (aminopropyl) piperazine.

6. The aqueous polyurethane or polyurethane-urea dispersion according to any of claims 1 to 5, wherein component b) is selected from the group consisting of linear polyester diols having a number average molecular weight of 400 to 5000 and/or slightly branched polyester diols having a number average molecular weight of 400 to 5000; and/or

The component c) is selected from diisocyanates and/or polyisocyanates, preferably diisocyanates;

the diisocyanate is preferably selected from one or more of tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 1, 4-cyclohexane diisocyanate, isophorone diisocyanate, 4' -dicyclohexylmethane diisocyanate, 4' -dicyclohexylpropane diisocyanate, 1, 4-phenylene diisocyanate, 2, 4-toluene diisocyanate, 2, 6-toluene diisocyanate, 4' -diphenylmethane diisocyanate, 2' -diphenylmethane diisocyanate, 2,4' -diphenylmethane diisocyanate, tetramethylxylylene diisocyanate, and p-xylylene diisocyanate; more preferably one or more selected from the group consisting of 1, 4-cyclohexane diisocyanate, isophorone diisocyanate and 4,4' -dicyclohexylmethane diisocyanate;

the component c) is more preferably a mixture of hexamethylene diisocyanate and isophorone diisocyanate or a mixture of hexamethylene diisocyanate and 4,4' -dicyclohexylmethane diisocyanate.

7. The aqueous polyurethane or polyurethane-urea dispersion according to any one of claims 1 to 6,

said component d) is selected from one or more of hydrophilic compounds containing ionic groups and containing 2-3 NCO-reactive functional groups, hydrophilic compounds containing potentially ionic groups and containing 2-3 NCO-reactive functional groups, and hydrophilic compounds containing nonionic groups and containing 2-3 NCO-reactive functional groups;

the hydrophilic compound having an ionic group and 2 to 3 NCO-reactive functional groups and/or the hydrophilic compound having a potentially ionic group and 2 to 3 NCO-reactive functional groups is preferably one or more selected from the group consisting of dihydroxy carboxylic acid and salts thereof, trihydroxy carboxylic acid and salts thereof, dihydroxy sulfonic acid and salts thereof, trihydroxy sulfonic acid and salts thereof, diamino sulfonic acid and salts thereof, triamino sulfonic acid and salts thereof, diamino carboxylic acid and salts thereof, triamino carboxylic acid and salts thereof, dimethylol propionic acid and alkali metal and/or ammonium salts thereof, dimethylol butyric acid and alkali metal and/or ammonium salts thereof, dihydroxy succinic acid and alkali metal and/or ammonium salts thereof, N- (2-aminoethyl) -2-aminoethane sulfonic acid and salts, One or more of N- (3-aminopropyl) -2-aminoethanesulfonic acid and alkali metal salts and/or ammonium salts thereof, N- (3-aminopropyl) -3-aminopropanesulfonic acid and alkali metal salts and/or ammonium salts thereof, and N- (2-aminoethyl) -3-aminopropanesulfonic acid and alkali metal salts and/or ammonium salts thereof;

the hydrophilic compound containing the nonionic group and 2-3 NCO reactive functional groups is preferably polyether glycol, and more preferably polyether glycol with the number average molecular weight of 200-8000 and the number of ethylene oxide of 4-200;

the component d) is more preferably selected from the group consisting of alkali metal salts of N- (2-aminoethyl) -2-aminoethanesulfonic acid, ammonium dimethylolpropionate and Ymer from the company Boston^TMOne or more of N-120; and/or

The component e) is selected from monofunctional polyethoxy ether with the number average molecular weight of 200-8000 and the ethylene oxide number of 4-200, and preferably selected from polyethylene glycol monomethyl ether with the number average molecular weight of 500-3000 and the ethylene oxide number of 12-75; and/or

The component f) is selected from one or more of aliphatic primary monoamines, aliphatic secondary monoamines, cycloaliphatic primary monoamines, cycloaliphatic secondary monoamines, amino alcohols, aliphatic diamines, cycloaliphatic diamines, aliphatic triamines, cycloaliphatic triamines and hydrazines, preferably from one or more of isophorone diamine, N- (2-hydroxyethyl) ethylenediamine and 1, 6-hexamethylenediamine; and/or

The component g) is selected from one or more of butanone oxime, dimethylpyrazole, caprolactam, malonic ester, triazole, dimethyl triazole, tert-butylbenzylamine, cyclopentanone carboxyethyl ester, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate and pentaerythritol triacrylate.

8. The aqueous polyurethane or polyurethane-urea dispersion according to any one of claims 1 to 7, characterized in that the aqueous polyurethane or polyurethane-urea dispersion has a solids content of 15 to 70 wt. -%, preferably 30 to 60 wt. -%;

the pH value of the aqueous dispersion of polyurethane or polyurethane-urea is 7.5-11, preferably 7.5-10, and more preferably 7.5-8.5;

the average particle diameter of the polyurethane or polyurethane-urea aqueous dispersion is 20-750 nm, preferably 50-450 nm.

9. A process for the preparation of an aqueous polyurethane or polyurethane-urea dispersion according to any one of claims 1 to 8, characterized in that it comprises the following steps:

10. Use of an aqueous polyurethane or polyurethane-urea dispersion according to any one of claims 1 to 8 or obtained by the process according to claim 9 in an adhesive.