CN114621416A

CN114621416A - Aqueous polyurethane dispersion, preparation method and application thereof in two-component spray glue

Info

Publication number: CN114621416A
Application number: CN202011447387.7A
Authority: CN
Inventors: 王萃萃; 纪学顺; 晋云全; 张斌
Original assignee: Wanhua Chemical Group Co Ltd
Current assignee: Wanhua Chemical Group Co Ltd
Priority date: 2020-12-09
Filing date: 2020-12-09
Publication date: 2022-06-14
Anticipated expiration: 2040-12-09
Also published as: CN114621416B

Abstract

The invention relates to an aqueous polyurethane dispersion, a preparation method and application thereof in two-component spray glue. Wherein the preparation of the aqueous polyurethane dispersion comprises the steps of diluting and dissolving the diisocyanate-terminated prepolymer with acetone, carrying out the shearing dispersion after the amine chain extension reaction, and adding C in the dispersion₁₀‑C₂₅And (3) carrying out post-chain extension reaction on amine of the hydrophobic chain segment to obtain the aqueous polyurethane dispersion. When the adhesive is used for preparing the bi-component spray adhesive, the adhesive can be immediately bonded by spraying the adhesive on a base material, and the prepared adhesive has the characteristics of no toxicity, greenness, environmental protection, bonding at room temperature, high bonding strength, good heat resistance, soft hand feeling, secondary bonding and the like.

Description

Aqueous polyurethane dispersion, preparation method and application thereof in two-component spray glue

Technical Field

The invention belongs to the technical field of adhesives, and particularly relates to an aqueous polyurethane dispersion, a preparation method and application thereof in two-component spray adhesive.

Background

The spray glue is a common adhesive for producing soft furniture and is widely applied to the fields of furniture, cloth art, decoration, light materials and the like. For a long time, neoprene adhesives have been widely favored. In recent years, some large adhesive companies (such as costa) at home and abroad have started to put forward a two-component water-based chloroprene adhesive, that is, a chloroprene latex is used as a main component together with an auxiliary agent such as a tackifying emulsion and a curing agent. When the curing agent and the neoprene latex are in direct contact, the adhesive film is broken and formed, so that the adhesion is generated.

CN103865439A discloses a bi-component water-based neoprene spray adhesive, wherein one component is a mixture of water-based neoprene emulsion, water-based polyurethane emulsion and water-based acrylic emulsion, and the other component is an auxiliary agent such as tackifying resin, a curing agent, an ultraviolet absorbent and the like, and the two components are mixed when in use. The first component is a mixture of three emulsions, and the mixing process is complicated, so that the construction efficiency is influenced. Meanwhile, the pH value of the water-based neoprene latex can be slowly reduced along with the time, the stability of the latex is directly influenced, the latex is demulsified and coagulated, the shelf life of the latex of a common manufacturer is very short, and great risk is caused to a client in use.

CN107857913A discloses a storage-stable aqueous neoprene adhesive, which achieves the purpose of maintaining the pH stability of a system by adding lithium salt and a complex compound into latex to inhibit chloride ions from overflowing from the neoprene adhesive and rapidly absorb decomposed chloride ions, thereby improving the storage stability of the system. However, the aqueous chloroprene has problems of yellowing and halogen residue in use.

CN104531036A discloses a two-component waterborne polyurethane spray adhesive, which takes waterborne polyurethane as a main raw material, a waterborne catalyst as a second component, unsaturated double bonds which can be oxidized and crosslinked at normal temperature are introduced into the molecular structure of the waterborne polyurethane, the waterborne catalyst can enable water in the waterborne polyurethane to be dissociated at normal temperature, generated ions can instantly activate the unsaturated double bonds in the waterborne polyurethane to be opened, and oxygen in air is matched for drying and oxidative crosslinking, so that the base materials can be quickly bonded. However, the polymerization is carried out by matching the drier with oxygen in the air, the efficiency is very low, the aqueous drier contains heavy metal elements, and meanwhile, the preparation of the aqueous polyurethane emulsion adopts a carboxylate system and is neutralized by a dimethylethanolamine solution, so that the VOC of the emulsion is higher, the influence on the body of workers is caused, and the environment is also polluted.

CN103946256A discloses a cold contact adhesive, which can realize bonding without activation, wherein polyols adopted in the polyurethane synthesis process are crystalline and amorphous, but the prepared adhesive has hard hand feeling and short bonding time, can not realize secondary bonding, and limits the application range of the adhesive.

Therefore, the development of a resin which has good stability, soft hand feeling, excellent adhesion performance and green environmental protection has become one of the problems to be solved in the field.

Disclosure of Invention

The present invention addresses the above-described deficiencies in the prior art and aims to provide an aqueous polyurethane dispersion and a method of making. The aqueous polyurethane dispersion and the curing agent are sprayed on a substrate, and bonding can be immediately realized. The adhesive prepared by the method has the characteristics of no toxicity, environmental protection, high bonding strength, good heat resistance, soft hand feeling, secondary bonding realization and the like, can be bonded at room temperature.

The invention also aims to provide the application of the double-component spray glue, which is suitable for bonding furniture such as sofas, mattresses and the like, and soft base materials such as sponges, leather, cloth art and the like.

In order to achieve the above object, the technical solution of the present invention is as follows:

the invention provides an aqueous polyurethane dispersion which is prepared by reacting raw materials comprising the following components:

a) at least one polyester polyol having a melting temperature in the range of 40 to 80 ℃ measured by differential scanning calorimetry according to DIN65467 at a heating rate of 20K/min;

b) at least one low or non-crystalline polyester polyol and/or polyether polyol, said low or non-crystalline polyester polyol having a melting temperature of less than 30 ℃ as measured by differential scanning calorimetry according to DIN65467 at a heating rate of 20K/min;

c) at least one polyisocyanate;

d) at least one hydrophilic compound, wherein the hydrophilic group of the hydrophilic compound comprises one or two of an ionic group and a potential ionic group, and the hydrophilic compound contains 2-3 NCO reactive functional groups;

preferably, the ionic group is selected from carboxylate (-COO)^-) And/or sulfonate (-SO)₃ ^-) (ii) a The potential ionic group refers to a functional group having a covalent bond, preferably a carboxyl group (-COOH) and/or a sulfonic acid group (-SO)₃H) (ii) a The NCO-reactive functional group is an amino group;

e) at least one C-containing compound₁₀～C₂₅An amine compound of a hydrophobic segment;

f) optionally, a compound containing 1 to 3 amino groups.

The aqueous polyurethane dispersion comprises the following components in percentage by mass (namely the sum of the mass of the components a) to f)) of 100 percent of the total mass of solid parts contained in the aqueous polyurethane dispersion:

component a)50 to 74 wt.%, preferably 55 to 73 wt.%;

component b)14 to 39 wt.%, preferably 16 to 32 wt.%;

8.5 to 12 percent of component c), preferably 9.5 to 11 percent;

component d)1.5 to 2.7 wt.%, preferably 1.7 to 2.5 wt.%;

1 to 2.5 wt.%, preferably 1.5 to 2.2 wt.% of component e);

0 to 2.5 wt.%, preferably 0 to 2 wt.%, of component f).

Further, the component a) of the invention has the number average molecular weight of 500-10000; one or more of dihydric alcohol, trihydric alcohol and tetrahydric alcohol with the number average molecular weight of 1000-5000 are preferably selected; further preferably one or more of a polyester polyol of a polyadipic acid series, a polycarbonate polyol and a polycaprolactone polyol, the number average molecular weight of which is 2000 to 4000 and the functionality of which is 2, and more preferably 1, 4-butanediol adipate diol.

Further, the component b) of the present invention is a low-crystallinity or non-crystalline polyester polyol and/or polyether polyol having a number average molecular weight of 500 to 10000, preferably a diol and/or triol having a number average molecular weight of 1000 to 4000, and more preferably a diol and/or triol having a number average molecular weight of 1000 to 3000;

more preferably, the low-crystallinity or non-crystalline polyester polyol is one or more of a polyester polyol of a polyadipic acid series, a polyester polyol of a polybenzoic acid series, and a polyester polyol of a polycarbonate, which have a number average molecular weight of 1000 to 3000 and a melting temperature of less than 35 ℃ as measured by differential scanning calorimetry according to DIN65467 at a heating rate of 20K/min; the polyester polyols of the polyadipic acid series and the polyester polyols of the polybenzoic acid series are particularly preferably one or more of polyhexamethylene glycol neopentyl glycol adipate diol, polyhexamethylene glycol adipate diol and 1, 6-hexanediol phthalate;

further preferably, the low crystallinity or non-crystalline polyester polyol is a linear polyester diol or a slightly branched polyester diol, for example obtainable by dehydration and condensation from a carboxylic acid and/or an anhydride such as an aliphatic, alicyclic, aromatic dicarboxylic or polycarboxylic acid or the corresponding anhydride thereof and the like and a polyhydric alcohol by known means, the carboxylic acid or anhydride including, but not limited to, one or more of succinic acid, methylsuccinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, nonane dicarboxylic acid, decane dicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexane dicarboxylic acid, maleic acid, fumaric acid, malonic acid, trimellitic acid, phthalic anhydride, trimellitic anhydride, succinic anhydride; the polyhydric alcohol includes but is not limited to one or more of ethylene glycol, diethylene glycol, 1, 2-propylene glycol, 1, 3-propylene glycol, 1, 4-butanediol, 1, 3-butanediol, 2, 3-butanediol, 1, 5-pentanediol, neopentyl glycol, 1, 6-hexanediol, 2-dimethyl-1, 3-propanediol, 1, 4-dihydroxycyclohexane, 1, 4-dimethylolcyclohexane, 1, 8-octanediol, 1, 10-decanediol, 1, 12-dodecanediol;

further preferably, the polycarbonate polyol with low crystallinity or non-crystallinity is prepared by the reaction of diol and carbonate, wherein the diol is selected from 1, 4-butanediol, 1, 5-pentanediol and 1, 6-hexanediol, and the carbonate is selected from diaryl carbonate and dialkyl carbonate, wherein the diaryl carbonate is preferably diphenyl carbonate, and the dialkyl carbonate is preferably dimethyl carbonate; more preferably a polycarbonate polyol prepared by reacting 1, 5-pentanediol with dimethyl carbonate;

more preferably, the polyether polyol is a polyaddition product of styrene oxide, or a polyaddition product of ethylene oxide, propylene oxide, tetrahydrofuran, butylene oxide, epichlorohydrin and the like as monomers; or polyether polyols obtained by polycondensation of polyols or mixtures thereof; or a polyether polyol obtained by alkoxylation of a polyol, an amine and an aminoalcohol, more preferably a polyoxyethylene polyol, a polyoxypropylene polyol, and particularly preferably a polyoxypropylene ether glycol.

Optionally, the low-crystallinity or non-crystalline polyester polyol may further be added with a polyol having a higher functional group, such as trimethylolpropane, glycerol or pentaerythritol.

In addition, alicyclic, aromatic dihydroxy and/or polyhydroxy compounds may also be used as the polyol for preparing the polyester polyol having low crystallinity or non-crystallinity, and preferably polyester polyol obtained by dehydrating and condensing one or more of isophthalic acid, terephthalic acid and adipic acid with one or more of neopentyl glycol, ethylene glycol and diethylene glycol.

Further, component c) of the present invention is selected from one or more aromatic, aliphatic or cycloaliphatic polyisocyanates, preferably aromatic, aliphatic or cycloaliphatic isocyanates having two isocyanate groups, more preferably diisocyanate Y (NCO)₂Wherein 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 aliphatic hydrocarbon group having 6 to 15 carbon atomsA divalent aromatic hydrocarbon group of carbon atoms or a divalent araliphatic hydrocarbon group of 7 to 15 carbon atoms;

preferably, 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, tetramethylxylyl diisocyanate, and p-xylylene diisocyanate.

Further preferably, the diisocyanate is a mixture of aliphatic and cycloaliphatic diisocyanates, such as a mixture of hexamethylene diisocyanate and one or more of 1, 4-cyclohexane diisocyanate, isophorone diisocyanate, 4 '-dicyclohexylmethane diisocyanate, and 4,4' -dicyclohexylpropane diisocyanate, and more preferably a mixture of hexamethylene diisocyanate and isophorone diisocyanate.

In some embodiments of the present invention, in addition to the simple diisocyanates described above, polyisocyanates having a functionality of more than 2 isocyanate groups per molecule may be present, such as polyisocyanates prepared by modification of one or more of the simple aliphatic, cycloaliphatic, araliphatic, aromatic diisocyanates or synthesized from at least two diisocyanates (having one or more of the structures uretdione, isocyanurate, urethane, allophanate, biuret, carbodiimide, iminooxadiazinedione, oxadiazinetrione).

The polyisocyanates of the present invention may also include up to 5 wt.% (based on polyurethane solids) of higher functional polyisocyanates or modified polyisocyanates containing, for example, one or more of carbodiimide groups, allophanate groups, isocyanurate groups, urethane groups, biuret groups.

Furthermore, the component d) of the present invention is a hydrophilic compound which simultaneously contains 2 to 3 NCO-reactive groups, and at least one ionic or potentially ionic group is preferably di-or trihydroxy carboxylic acid, di-or trihydroxy sulfonic acid, di-or triamino carboxylic acid or their salts, more preferably dimethylolpropionic acid, dimethylolbutyric acid, dimethylolacetic acid, dihydroxysuccinic acid, N- (2-aminoethyl) -2-aminoethanesulfonic acid, N- (3-aminopropyl) -3-aminopropanesulfonic acid, N- (2-aminoethyl) -B-alanine and the alkali metal or ammonium salts of the above compounds; most preferably one or both of N- (2-aminoethyl) -2-aminoethane sulfonate and/or N- (2-aminoethyl) -B-alaninate.

In some embodiments of the invention, if a potentially ionic compound is used as component d), the neutralizing agent may be added before, during or after dispersion. The amount of neutralizing agent added may be such that some or all of the potentially ionic groups are ionic groups. Suitable neutralizing agents are, for example, one or more of alkali metal compounds, alkaline earth metal compounds, examples of suitable neutralizing agents include, but are not limited to, one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide, or calcium hydroxide, among others. 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. Particularly preferably, the degree of neutralization is 80 to 95%. The person skilled in the art understands that in addition to the acid groups being neutralized to form ionic groups, free neutralizing agents are present in the system, wherein the degree of neutralization is the amount of added neutralizing agent/total amount of acid groups introduced, and in this formula the term "amount" refers to molar amounts.

Further, component e) of the present invention, said composition containing C₁₀～C₂₅The amino compound of the hydrophobic chain segment has a structure shown in a formula I:

wherein R is C₁₀～C₂₅Alkyl groups of (a);

said C is₁₀～C₂₅The amino compound of the hydrophobic chain segment is a product obtained by carrying out Michael addition reaction on diethylenetriamine and esters shown in a formula II, wherein the ester structure shown in the formula II is shown as follows:

wherein R is as defined for formula I, i.e. C₁₀-C₂₅Y is a H atom or-CH₃；

Preferably, the esters represented by formula ii include, but are not limited to, one or more of acrylate compounds and methacrylate compounds, and more preferably, such as lauryl methacrylate and/or cetyl methacrylate.

In some embodiments of the invention, the C-containing compound₁₀-C₂₅The amino compound of the hydrophobic chain segment is prepared by the following method, mixing diethylenetriamine, esters shown in a formula II, alkali and a solvent, and heating to carry out Michael addition reaction;

preferably, the molar ratio of the diethylenetriamine to the ester shown in the formula II is 1: 0.4 to 0.7, preferably 1: 0.5 to 0.66;

the alkali is selected from triethylamine, sodium ethoxide, sodium hydride, sodium amide and the like, and preferably, the use amount of the alkali is 1.5-2.5 times of the mass of diethylenetriamine.

The solvent is selected from dioxane, tetrahydrofuran, methyl tert-butyl ether and the like; preferably, the using amount of the solvent is 50-100 times of the mass of the diethylenetriamine.

The Michael addition reaction temperature is 50-80 ℃, preferably 65-75 ℃, and the time is 2-4 hours, preferably 3-4 hours.

After the reaction is finished, the method also comprises a vacuum distillation post-treatment operation, wherein the vacuum distillation condition is that the vacuum degree is 0.005-0.01Mpa, and the temperature is 80-100 ℃.

Further, the component f) of the present invention is a compound containing 1 to 3 amino groups, wherein the amino groups are primary amino groups and/or secondary amino groups;

preferably, the compound containing 1 to 3 amino groups is a diamine and/or triamine, preferably, for example, one or more of 1, 2-ethylenediamine, hydroxyethylethylenediamine, 1, 6-hexamethylenediamine, 1-amino-3, 3, 5-trimethyl-5-aminomethylcyclohexane (isophoronediamine), N-aminoethylpiperazine, 1, 4-diaminocyclohexane, bis- (4-aminocyclohexyl) methane and diethylenetriamine, adipic acid dihydrazide, and hydrazine hydrate; more preferably one or more of isophoronediamine, hydroxyethylethylenediamine and N-aminoethylpiperazine.

The aqueous polyurethane dispersion comprises 30-70 wt%, preferably 40-50 wt% of solid content, and the balance of water; the average particle diameter is usually 100 to 300nm, preferably 150 to 250 nm.

The pH value of the aqueous polyurethane dispersion is 4-11, preferably 7-9.

The invention also provides a preparation method of the aqueous polyurethane dispersion, which comprises the following steps:

1) mixing the components a), b) and c) with a solvent, and reacting under the protection of inert gas until the reaction mixture reaches the theoretical isocyanate content to obtain an isocyanate-terminated prepolymer;

2) adding a solvent into the isocyanate-terminated prepolymer for dilution, then adding the components d) and f) for chain extension reaction, and adding water for dispersion after the chain extension reaction is finished to obtain an aqueous polyurethane dispersion 1;

3) adding a component e) dissolved by a solvent into the aqueous polyurethane dispersion 1 to carry out chain extension reaction, and then carrying out reduced pressure distillation to remove the solvent to obtain the aqueous polyurethane dispersion.

In the preparation method of the invention, in the steps 1) to 3), the solvent is a solvent which can be partially or completely removed by distillation during or after dispersion, and the solvent is selected from one or more of acetone, methyl isobutyl ketone, butanone, tetrahydrofuran, dioxane, acetonitrile, dipropylene glycol dimethyl ether and 1-methyl-2-pyrrolidone, preferably acetone and/or butanone, more preferably acetone; the solvents in step 1) and step 2) may be the same or different;

preferably, the adding amount of the solvent in the step 1) is 0.05 to 0.3 time, preferably 0.1 to 0.2 time of the total mass (namely the sum of the mass of the components a) to c)) of the solid components added in the step 1); the adding amount of the solvent in the step 2) is 1-3 times, preferably 1.2-2.2 times of the total mass of the solid components added in the step 1); in the step 3), the concentration of the acetone-soluble component e) is 20-30 wt%.

In the preparation method, in the step 1), the reaction temperature is 70-90 ℃, preferably 75-85 ℃; the time is 1 to 3 hours, preferably 1.5 to 2.5 hours; the reaction is carried out under the protection of an inert gas, preferably nitrogen. The conversion is usually 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), preferably chemopotentiometric titrations, can be carried out.

The preparation method of the invention, step 1), is carried out under the action of a catalyst, wherein the catalyst is a catalyst known by a person skilled in the art for accelerating the reaction of NCO and OH, and is selected from triethylamine, 1, 4-diazabicyclo- [2,2,2] -octane, dibutyltin oxide, tin dioctoate or dibutyltin dilaurate, tin bis- (2-ethylhexanoate), bismuth neodecanoate and bismuth 2-ethylhexanoate, preferably bismuth neodecanoate and bismuth 2-ethylhexanoate, and more preferably bismuth neodecanoate;

preferably, the amount of the catalyst is 0.003-0.03 percent of the total mass of the components a), b) and c).

In the preparation method, in the step 2), the chain extension reaction is carried out at the temperature of 30-50 ℃, preferably 35-45 ℃; the time is 1-30 min, preferably 10-15 min.

In the preparation method, in the step 2), after the water is added for dispersion, the solid content of the aqueous polyurethane dispersion 1 is 40-50% (by mass of the water and the solid).

In the preparation method, in the step 3), the chain extension reaction is carried out at room temperature for 1-30 min, preferably 5-10 min.

In the preparation method, in the step 3), the vacuum degree in the reduced pressure distillation process is 0.07-0.1 MPa, and the temperature is 35-55 ℃.

The invention also provides application of the aqueous polyurethane dispersion, and the aqueous polyurethane dispersion can be matched with a curing agent to be used in the fields of adhesives, bonding agents, sealants and the like. According to the application, the invention provides a bi-component spray glue, which comprises the following components in parts by weight:

component A): 100 parts of an aqueous polyurethane dispersion;

component B): 4-10 parts of curing agent, preferably 6-8 parts.

In the spray glue of the invention, the aqueous polyurethane dispersion is the aqueous polyurethane dispersion described in the invention or prepared by the above method of the invention.

In the spray glue, the curing agent is selected from a salt solution containing metal ions, preferably CaCl with the concentration of 2-5 wt%₂Aqueous solution and/or ZnSO₄An aqueous solution.

When the bi-component spray adhesive is used, the component A containing the aqueous polyurethane dispersion is sprayed on a base material, and then the component B is sprayed, or a bi-component spray gun is used for simultaneously spraying the two A, B components on the base material.

The double-component spray glue is suitable for soft material industries such as sponge, leather, cloth and other soft base materials, and can be used for furniture industries such as mattresses, sofas, swivel chairs, pillows and the like; and also widely applied to the manufacturing industries of vehicles such as automobile interiors, aviation, high-speed rail seats and the like.

According to the aqueous polyurethane dispersion, a certain amount of amine compounds with long carbon chain flexible structures are introduced into a polyurethane side chain, the amine compounds have three amino groups, and can react with NCO at the tail end of a polyurethane chain segment to play a role of a chemical cross-linking point, so that the heat resistance of a sample is improved, meanwhile, the introduction of the long carbon chain structures also increases the flexibility of the polyurethane chain segment, so that the chain segment is plasticized, the Tg is reduced, the viscosity maintaining time is prolonged, secondary bonding can be realized, the bonded material is softer in hand feeling, and the problems of accelerator migration, heat resistance reduction and the like caused by the addition of a plasticizer into the existing aqueous polyurethane are solved. Meanwhile, the addition amount of the amine compound needs to be controlled within the range of the invention, too little addition amount has insignificant heat resistance, viscosity and hand feeling improvement of the bonded material, and on the contrary too much addition amount has obvious heat resistance reduction because the increase of the flexible chain segment damages the crystallization type of the polyurethane chain segment.

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

1. after the aqueous dispersion is sprayed on a base material together with a waterborne curing agent, the bonding can be realized immediately, and the bonding strength is high;

2. after the aqueous dispersion is sprayed on a substrate together with an aqueous curing agent, the aqueous dispersion has good viscosity, can be bonded for the second time, has soft hand feeling and good heat resistance, and is particularly suitable for soft substrates such as sponge, leather, cloth and the like;

3. when the aqueous polyurethane dispersion is used, no plasticizer is required to be compounded, so that the influence caused by the migration of the plasticizer is avoided.

Detailed Description

The technical solution of the present invention is further described with reference to the following examples.

The main raw materials of the embodiment of the invention are as follows, and if not specially explained, the main raw materials are all common raw materials purchased from the market:

component a):

polyester polyol I: poly1, 4-butanediol adipate diol, M_n2000g/mol, a melting temperature of 40 to 50 ℃ measured by differential scanning calorimetry according to DIN65467 at a heating rate of 20K/min

Wanhua chemistry);

polyester polyol II: poly1, 4-butanediol adipate diol, M_n3000g/mol, a melting temperature of from 50 to 60 ℃ measured by differential scanning calorimetry according to DIN65467 at a heating rate of 20K/min

Wanhua chemistry);

polyester polyol III: 1, 6-hexanediol polycarbonate, Mn 2000g/mol, a melting temperature of 40 to 50 ℃ measured by differential scanning calorimetry according to DIN65467 at a heating rate of 20K/min

Japan;

polyester polyol IV: polycaprolactone diol, Mn 2000g/mol, with a melting temperature of 40-50 ℃ (PCL 220, xylonite, japan) measured by differential scanning calorimetry according to DIN65467 at a heating rate of 20K/min;

component b):

polyester polyol V: polyethylene glycol adipate diol, M_n2000g/mol, a melting temperature of-50 to-40 ℃ measured by differential scanning calorimetry according to DIN65467 at a heating rate of 20K/min

Wanhua chemistry);

polyester polyol VI: polyhexanediol neopentyl glycol adipate diol, M_n1500g/mol, a melting temperature of 20 to 30 ℃ (CMA654, huada chemical) measured by differential scanning calorimetry according to DIN65467 at a heating rate of 20K/min;

polyester polyol VII: polyneopentyl glycol adipate diol, M_n2000g/mol, a melting temperature of-45 to-35 ℃ measured by differential scanning calorimetry according to DIN65467 at a heating rate of 20K/min (PNA2000, huada chemical);

polyester polyol VIII: 1, 6-hexanediol phthalate, M_n2000g/mol, a melting temperature of-30 to-20 ℃ measured by differential scanning calorimetry according to DIN65467 at a heating rate of 20K/min (PH-56, Stepan, usa);

polyether polyol I: polyoxypropylene ether glycol, M_n2000g/mol, a non-crystalline polyol having a melting temperature, measured by differential scanning calorimetry according to DIN65467 at a heating rate of 20K/min, of from-60 to-50 ℃,

wanhua chemistry);

component c):

polyisocyanate I: hexamethylene diiso-methylCyanate ester

Wanhua chemistry);

polyisocyanate II: isophorone diisocyanate

Wanhua chemistry);

component d):

n- (2-aminoethyl) -2-aminoethane sulfonate salt:

EVONIK, usa);

n- (2-aminoethyl) -B-alanine monosodium salt: (Shanghai-derived leaf Biotech Co., Ltd.); component e):

amine-based compound A: the preparation method comprises the steps of adding 10.3g of diethylenetriamine and 15.4g of lauryl methacrylate into a three-neck flask, adding 520g of 1, 4-dioxane as a solvent, adding 16g of triethylamine as an alkali, heating to 80 ℃, reacting for 4 hours, recovering to room temperature, and distilling under reduced pressure to evaporate required components to obtain the amino compound A, wherein the structural formula of the amino compound A is as follows:

for amino compounds A¹HNMR, various hydrogen bond chemical shifts δ H (300MHZ, CDCl)₃) The attribution of (a) is expressed as follows: a (0.88ppm, t, 3H), b (1.19ppm, d, 3H), c (1.26ppm, m, 6H), d (1.29ppm, m, 8H), e (1.31ppm, m, 2H), f (1.43ppm, m, 2H), g (1.62ppm, m, 2H), H (2.49ppm, m, 1H), i (2.52ppm, m, 2H), j (2.62ppm, m, 2H), k (2.66ppm, m, 4H), l (4.08ppm, t, 1H);

an amine-based compound B: the preparation method comprises the steps of adding 10.3g of diethylenetriamine and 18.7g of hexadecyl methacrylate into a three-neck flask, adding 520g of 1, 4-dioxane as a solvent, adding 16g of triethylamine as an alkali, heating to 80 ℃, reacting for 4 hours, recovering to room temperature, and distilling under reduced pressure to evaporate needed components to obtain an amino compound B, wherein the structural formula of the amino compound B is as follows:

for amino compounds B¹HNMR, various hydrogen bond chemical shifts δ H (300MHZ, CDCl)₃) The attribution of (a) is expressed as follows: a (0.88ppm, t, 3H), b (1.19ppm, d, 3H), c (1.26ppm, m, 14H), d (1.29ppm, m, 8H), e (1.31ppm, m, 2H), f (1.43ppm, m, 2H), g (1.62ppm, m, 2H), H (2.49ppm, m, 1H), i (2.52ppm, m, 2H), j (2.62ppm, m, 2H), k (2.66ppm, m, 4H), l (2.77ppm, t, 1H), m (3.02ppm, d, 1H), n (4.08ppm, t, 2H).

Amine-based compound C: the preparation method comprises the steps of adding 10.3g of diethylenetriamine and 14.7g of butyl methacrylate into a three-neck flask, adding 520g of 1, 4-dioxane as a solvent, adding 16g of triethylamine as an alkali, heating to 80 ℃, reacting for 4 hours, recovering to room temperature, and distilling under reduced pressure to evaporate needed components to obtain an amino compound C, wherein the structural formula of the amino compound C is as follows:

for amino compounds C¹HNMR, various hydrogen bond chemical shifts delta H (300MHZ, CDCl)₃) The attribution of (a) is expressed as follows: a (0.90ppm, t, 3H), b (1.19ppm, d, 3H), c (1.45ppm, m, 2H), d (1.62ppm, m, 2H), e (2.49ppm, m, 1H), f (2.52ppm, m, 2H), g (2.62ppm, m, 2H), H (2.66ppm, m, 4H), i (2.77ppm, t, 2H), j (4.08ppm, t, 2H).

Amino compounds A to C¹HNMR test method: a Bruker AC-400FT nuclear magnetic resonance tester; test conditions were 300MHz using CDCl₃To test the solvent, the 7.26ppm hydrogen spectra were scaled 77.16ppm carbon spectra were scaled.

Component f):

isophorone diamine: (IPDA, wanhua chemistry);

hydroxyethyl ethylenediamine: (AEEA, raisin stone BASF);

n-aminoethylpiperazine: (AEP, Meyer chemical technology, Inc. of Shanghai).

Example 1

Preparing an aqueous polyurethane dispersion comprising the steps of:

1) adding 200g of polyester polyol I, 80g of polyester polyol V, 38g of isocyanate I, 0.019g of bismuth neodecanoate and 38g of acetone into a four-neck flask provided with a reflux condenser, a thermometer and mechanical stirring, reacting at 80 ℃, sampling every 1h to measure NCO%, and stopping the reaction after 3h until the NCO% reaches below the theoretical content of 2.03%, thus obtaining the isocyanate-terminated prepolymer.

2) Cooling the isocyanate-terminated prepolymer to about 60 ℃, adding 471g of acetone, stirring, mixing and dissolving for 5min, then adding 3g of isophorone diamine, 2g of N-aminoethyl piperazine and 5.7g of acetone

Carrying out chain extension reaction on the mixed solution of 43g of deionized water at 45 ℃ for 15min, pouring the mixed solution into a dispersion cup, and adding 407g of water under the high-speed shearing condition of 1500rpm to obtain an aqueous polyurethane dispersion 1;

3) 7.5g of the amino compound A was dissolved in 30g of acetone, added to the aqueous polyurethane dispersion 1 and stirred for 10min, and the acetone was removed therefrom by distillation under reduced pressure to give an aqueous polyurethane dispersion having a solids content of 42% by weight and an average particle diameter of 182nm as determined by laser correlation in the dispersed phase, and a pH of 7.3.

Example 2

Preparing an aqueous polyurethane dispersion comprising the steps of:

1) adding 240g of polyester polyol I, 80g of polyester polyol VII, 38g of isocyanate I, 0.021g of bismuth neodecanoate and 43g of acetone into a four-neck flask provided with a reflux condenser, a thermometer and mechanical stirring, reacting at 80 ℃, sampling every 1h to measure NCO%, and stopping the reaction after 3h until the NCO% reaches below theoretical content of 1.39%, thus obtaining the isocyanate-terminated prepolymer.

2) Cooling the isocyanate-terminated prepolymer to about 60 ℃, adding 530g of acetone, stirring, mixing and dissolving for 5min, and then adding 25g of isophoronediamine, 0.2g of N-aminoethylpiperazine and 5.7g of isophoronediamine

Reacting the mixed solution with 34g of deionized water for 15min at the temperature of 45 ℃, pouring the mixed solution into a dispersion cup, and adding 468g of water under the high-speed shearing condition of 1500rpm to obtain an aqueous polyurethane dispersion 1;

3) 6g of the amine-based compound A was dissolved in 24g of acetone, added to the aqueous polyurethane dispersion 1 and stirred for 10min, and the acetone was removed therefrom by distillation under reduced pressure to give an aqueous polyurethane dispersion having a solids content of 42% by weight and an average particle diameter of 195nm as determined by laser correlation in the dispersed phase, and the pH was 7.7.

Example 3

Preparing an aqueous polyurethane dispersion comprising the steps of:

1) 288g of polyester polyol I, 72g of polyester polyol VI, 35g of isocyanate I, 10g of isocyanate II, 0.024g of bismuth neodecanoate and 65g of acetone are added into a four-neck flask provided with a reflux condenser, a thermometer and a mechanical stirrer, the mixture is reacted at 75 ℃, the NCO% is sampled every 1h for 3h until the NCO% reaches below 1.10% of theoretical content, and the reaction is stopped, thus obtaining the isocyanate-terminated prepolymer.

2) Cooling the isocyanate-terminated prepolymer to about 60 ℃, adding 624g of acetone, stirring, mixing and dissolving for 5min, then adding 0.2g of hydroxyethyl ethylenediamine and 6.8g of acetone

Reacting with 28g of deionized mixed solution for 15min at the temperature of 45 ℃, pouring into a dispersion cup, and adding 471g of water under the high-speed shearing condition of 1500rpm to obtain the waterborne polyurethane dispersion 1.

3) Dissolving 8g of amino compound A by 32g of acetone, adding the amino compound A into the aqueous polyurethane dispersion 1, and stirring for 10 min; the acetone was removed therefrom by distillation under reduced pressure to give an aqueous polyurethane dispersion having a solids content of 45% by weight and an average particle diameter of 222nm, determined by laser correlation in the dispersed phase, and a pH of 7.1.

Example 4

Preparing an aqueous polyurethane dispersion comprising the steps of:

1) 220g of polyester polyol II, 110g of polyester polyol VIII, 23g of isocyanate I, 12g of isocyanate II, 0.022g of bismuth neodecanoate and 62g of acetone are added into a four-neck flask provided with a reflux condenser, a thermometer and mechanical stirring, reaction is carried out at 85 ℃, sampling is carried out every 1h to measure NCO%, and the reaction is stopped after 3h until the NCO% reaches below the theoretical content of 1.23%, so as to obtain the isocyanate-terminated prepolymer.

2) Cooling the isocyanate-terminated prepolymer to about 60 deg.C, adding 668g acetone, stirring, mixing and dissolving for 5min, then adding 1.6g hydroxyethyl ethylenediamine and 6.6g

Reacting with 33g of deionized mixed solution for 15min at the temperature of 45 ℃, pouring into a dispersion cup, and adding 368g of water under the high-speed shearing condition of 1500rpm to obtain the aqueous polyurethane dispersion 1.

3) Dissolving 6.4g of amino compound B by using 25.6g of acetone, adding the dissolved amino compound B into the aqueous polyurethane dispersion 1, and stirring for 10 min; the acetone was removed therefrom by distillation under reduced pressure to give an aqueous polyurethane dispersion having a solids content of 48% by weight and an average particle diameter of 217nm, determined by laser correlation in the dispersed phase, and a pH of 7.4.

Example 5

Preparing an aqueous polyurethane dispersion comprising the steps of:

1) adding 200g of polyester polyol III, 110g of polyether polyol I, 27g of isocyanate I, 12g of isocyanate II, 0.021g of bismuth neodecanoate and 52g of acetone into a four-neck flask provided with a reflux condenser, a thermometer and a mechanical stirrer, reacting at 80 ℃, sampling every 1h to measure NCO%, stopping the reaction until the NCO% reaches below 1.25% of theoretical content after 3h, and obtaining the isocyanate-terminated prepolymer

2) Cooling the isocyanate-terminated prepolymer to about 60 ℃, adding 646g of acetone, stirring, mixing and dissolving for 5min, then adding a mixed solution of 0.5g of hydroxyethyl ethylenediamine, 8.5g N- (2-aminoethyl) -B alanine monosodium salt and 36g of deionized water, reacting for 10min at 45 ℃, pouring into a dispersion cup, and adding 396g of water under the high-speed shearing condition of 1500rpm to obtain the aqueous polyurethane dispersion 1.

3) Dissolving 7g of amino compound B by 28g of acetone, adding the amino compound B into the aqueous polyurethane dispersion 1, and stirring for 10 min; the acetone was removed therefrom by distillation under reduced pressure to give an aqueous polyurethane dispersion having a solids content of 45% by weight and an average particle diameter of 214nm, determined by laser correlation in the dispersed phase, and a pH of 7.4.

Example 6

Preparing an aqueous polyurethane dispersion comprising the steps of:

1) 190g of polyester polyol II, 140g of polyether polyol I, 23g of isocyanate I, 12g of isocyanate II, 0.022g of bismuth neodecanoate and 55g of acetone are added into a four-neck flask provided with a reflux condenser, a thermometer and mechanical stirring, the mixture is reacted at 80 ℃, NCO% is measured by sampling every 1h until the NCO% reaches below 1.15% of theoretical content, and the reaction is stopped, so that the isocyanate-terminated prepolymer is obtained.

2) Cooling the isocyanate-terminated prepolymer to about 60 ℃, adding 675g acetone, stirring, mixing and dissolving for 5min, then adding 2.5g isophorone diamine and 6.6g

Reacting with a mixed solution of 36g of deionized water at 45 ℃ for 15 min; poured into a dispersion cup, and 417g of water was added under high-speed shearing conditions of 1500rpm to obtain an aqueous polyurethane dispersion 1.

3) Dissolving 6g of amino compound B by using 24g of acetone, adding the amino compound B into the aqueous polyurethane dispersion 1, and stirring for 10 min; the acetone was removed therefrom by distillation under reduced pressure to give an aqueous polyurethane dispersion having a solids content of 45% by weight and an average particle diameter of 235nm, determined by laser correlation in the dispersed phase, and a pH of 7.8.

Example 7

Preparing an aqueous polyurethane dispersion comprising the steps of:

1) 300g of polyester polyol IV, 60g of polyether polyol I, 37g of isocyanate I, 4g of isocyanate II, 0.024g of bismuth neodecanoate and 60g of acetone are added into a four-neck flask provided with a reflux condenser, a thermometer and mechanical stirring, the mixture is reacted at 80 ℃, samples are taken every 1 hour to measure NCO% until the NCO% reaches below the theoretical content of 1.06%, and the reaction is stopped to obtain an isocyanate-terminated prepolymer.

2) Cooling the isocyanate-terminated prepolymer to about 60 ℃, adding 742g of acetone, stirring, mixing and dissolving for 5min, adding a mixed solution of 0.6g of N-aminoethyl piperazine, 9g N- (2-aminoethyl) -B alanine monosodium salt and 38g of deionized water, and reacting for 15min at 45 ℃; poured into a dispersion cup, and 458g of water was added under high-speed shearing at 1500rpm to obtain an aqueous polyurethane dispersion 1.

3) Dissolving 5g of amino compound B by using 20g of acetone, adding the amino compound B into the aqueous polyurethane dispersion 1, and stirring for 10 min; the acetone was removed therefrom by distillation under reduced pressure to give an aqueous polyurethane dispersion having a solids content of 45% by weight and an average particle diameter of 214nm, determined by laser correlation in the dispersed phase, and a pH of 7.6.

Example 8

Preparing an aqueous polyurethane dispersion comprising the steps of:

1) 220g of polyester polyol II, 110g of polyester polyol VIII, 23g of isocyanate I, 15g of isocyanate II, 0.022g of bismuth neodecanoate and 63g of acetone are added into a four-neck flask provided with a reflux condenser, a thermometer and mechanical stirring, reaction is carried out at 85 ℃, sampling is carried out every 1h to measure NCO%, and the reaction is stopped after 3h until the NCO% reaches below the theoretical content of 1.49%, so as to obtain the isocyanate-terminated prepolymer.

2) Cooling the isocyanate-terminated prepolymer to about 60 deg.C, adding 673g acetone, stirring, mixing and dissolving for 5min, and adding 5.7g

Reacting with 23g of deionized mixed solution for 15min at the temperature of 45 ℃, pouring into a dispersion cup, and adding 386g of water under the high-speed shearing condition of 1500rpm to obtain the aqueous polyurethane dispersion 1.

3) Dissolving 11g of amino compound A by 44g of acetone, adding the amino compound A into the aqueous polyurethane dispersion 1, and stirring for 10 min; the acetone was removed therefrom by distillation under reduced pressure to give an aqueous polyurethane dispersion having a solids content of 45% by weight and an average particle diameter of 234nm, determined by laser correlation in the dispersed phase, and a pH of 7.3.

Example 9

Preparing an aqueous polyurethane dispersion comprising the steps of:

2) Cooling the isocyanate-terminated prepolymer to about 60 ℃, adding 673g of acetone, stirring, mixing and dissolving for 5min, then adding 5g of isophorone diamine, 1g of N-aminoethyl piperidine and 5.7g of acetone

Reacting with 47g of deionized mixed solution at 45 ℃ for 15min, pouring into a dispersion cup, and adding 404g of water under the high-speed shearing condition of 1500rpm to obtain the aqueous polyurethane dispersion 1.

3) Dissolving 2.5g of amino compound A by 10g of acetone, adding the amino compound A into the aqueous polyurethane dispersion 1, and stirring for 10 min; the acetone was removed therefrom by distillation under reduced pressure to give an aqueous polyurethane dispersion having a solids content of 45% by weight and an average particle diameter of 223nm, determined by laser correlation in the dispersed phase, and a pH of 7.4.

Comparative example 1

An aqueous polyurethane dispersion was prepared, the procedure being as in example 1, except that 200g of polyester polyol I and 80g of polyester polyol V were replaced by 280g of polyester polyol I in step 1) to give an aqueous polyurethane dispersion having a solids content of 42% by weight and an average particle diameter of 193nm as determined by laser correlation in the dispersed phase, and a pH of 7.2, in accordance with example 1.

Comparative example 2

An aqueous polyurethane dispersion was prepared by the procedure of example 2, except that 240g of the polyester polyol I and 80g of the polyester polyol VII were replaced by 320g of the polyester polyol VII in step 1) to obtain an aqueous polyurethane dispersion having a solid content of 42% by weight and an average particle diameter of 207nm as determined by laser correlation in the dispersed phase, and a pH of 7.3, in accordance with example 2.

Comparative example 3

Preparation of an aqueous polyurethane Dispersion, the procedure being as in example 1, except that the aqueous polyurethane dispersion 1 obtained in step 2) was used and acetone was removed therefrom by distillation under reduced pressure to give an aqueous polyurethane dispersion having a solid content of 42% by weight and an average particle diameter of 203nm as determined by laser correlation in the dispersed phase, and the pH was 7.1

Comparative example 4

An aqueous polyurethane dispersion was prepared by the procedure of reference example 1, differing from example 1 only in that the amine-based compound A was replaced with cetyl methacrylate in the procedure of step 3), giving an aqueous polyurethane dispersion having a solid content of 42% by weight and an average particle diameter of 189nm as determined by laser correlation in the dispersed phase, and a pH of 7.1.

Comparative example 5

Preparation of an aqueous polyurethane dispersion, procedure with reference to example 1, differing from example 1 only in that the amine-based compound A was replaced with the amine-based compound C in step 3), an aqueous polyurethane dispersion was obtained having a solids content of 42% by weight and an average particle diameter of 174 as determined by laser correlation in the dispersed phase, and the pH was 7.0.

Adhesive application:

preparing an air compressor, adjusting the pressure to 3Bar, adjusting the diameter of a spray gun to be 1.5mm, and adjusting the size of a sponge to be 10 multiplied by 5 cm; 200g of each of the emulsions prepared in examples 1 to 7 and comparative examples 1 to 5 was placed in a two-component spray gun emulsion tank as component A, and CaCl was used at a concentration of 2.5 wt%₂200g of aqueous solution is placed in a two-component spray gun curing agent tank to be used as a component B, the flow rate of two nozzles is adjusted through a flowmeter, and an emulsion nozzle and CaCl are controlled₂The mass ratio of the water solution sprayed out of the nozzle is 100: 7.

Wet tack testing:

uniformly spraying glue on the surface of the sponge (about 100 g/m)²) Folding the sponge in half, investigating the wet adhesion,the wet tack is classified into A, A +, A + + + +5 grades from low to high in tack, with A being the worst and A + + + + the best;

and (3) secondary bonding test:

uniformly spraying glue on the surface of the sponge (about 100 g/m)²) Folding the sponge in half, tearing the sponge apart, bonding again, standing for 10min, and inspecting the secondary bonding performance according to the bouncing distance of the folded sponge;

bonding strength:

after the prepared sponge sample is placed for 30min, uniformly tearing, judging the bonding strength according to whether the sponge is damaged or not, wherein the 'material breakage' indicates that the base material is damaged when tearing; "tear" means that the substrate is capable of tearing intact without breakage;

and (3) hand feeling test:

placing the prepared sponge sample at normal temperature for 30min, testing hand feeling, and grading according to the hardness degree by 1-5 points, wherein the larger the hand feeling number is, the softer the sponge glue layer is after the sponge sample is attached;

and (3) heat resistance test:

and (3) placing the prepared sponge sample at normal temperature for 30min, then placing the sponge sample in an oven at 80 ℃ for 8h, and judging according to the fact that the sponge is flicked.

TABLE 1 Performance test of examples and comparative examples

Note: "No" means that the bondline does not hold the substrates together.

As shown in Table 1, the examples of the present invention are superior to the comparative examples 1 to 5 in wet tack, secondary adhesion, adhesive strength, touch, and heat resistance, and have a large practical application value.

It will be appreciated by those skilled in the art that, given the benefit of this disclosure, numerous modifications and adaptations to the present invention are possible. Such modifications or adaptations are intended to be within the scope of the present invention as defined in the claims.

Claims

1. An aqueous polyurethane dispersion, characterized by being prepared by reacting raw materials comprising:

c) at least one polyisocyanate;

preferably, the ionic groups are selected from carboxylate and/or sulfonate groups; the latent ionic group refers to a functional group having a covalent bond, preferably a carboxyl group and/or a sulfonic group; the NCO-reactive functional group is an amino group;

f) optionally, a compound comprising 1 to 3 amino groups.

2. The aqueous polyurethane dispersion according to claim 1, wherein the composition of the content of the components comprises, based on 100% by mass of the total solid content contained therein:

component a)50 to 74 wt.%, preferably 55 to 73 wt.%;

component b)14 to 39 wt.%, preferably 16 to 32 wt.%;

8.5 to 12 percent of component c), preferably 9.5 to 11 percent;

component d)1.5 to 2.7 wt.%, preferably 1.7 to 2.5 wt.%;

1 to 2.5 wt.%, preferably 1.5 to 2.2 wt.% of component e);

0 to 2.5 wt.%, preferably 0 to 2 wt.%, of component f).

3. The aqueous polyurethane dispersion according to claim 1 or 2, wherein component a) the polyester polyol has a number average molecular weight of 500 to 10000; one or more of dihydric alcohol, trihydric alcohol and tetrahydric alcohol with the number average molecular weight of 1000-5000 are preferably selected; further preferably one or more of poly adipic acid series polyester polyol, polycarbonate polyol and polycaprolactone polyol with the number average molecular weight of 2000-4000 and the functionality of 2, and more preferably poly adipic acid-1, 4-butanediol glycol; and/or

The component b) is low-crystallinity or non-crystallinity polyester polyol and/or polyether polyol, the number average molecular weight of which is 500-10000, preferably dihydric alcohol and/or trihydric alcohol with the number average molecular weight of 1000-4000, and further preferably dihydric alcohol and/or trihydric alcohol with the number average molecular weight of 1000-3000;

more preferably, the low-crystallinity or non-crystalline polyester polyol is one or more of a polyester polyol of a polyadipic acid series, a polyester polyol of a polybenzoic acid series, and a polyester polyol of a polycarbonate, which have a number average molecular weight of 1000 to 3000 and a melting temperature of less than 30 ℃ as measured by differential scanning calorimetry according to DIN65467 at a heating rate of 20K/min; particularly preferably one or more of polyhexamethylene glycol neopentyl glycol adipate diol, polyhexamethylene glycol adipate diol and 1, 6-hexanediol phthalate;

further preferably, the low-crystallinity or non-crystalline polyester polyol is a linear polyester diol or a slightly branched polyester diol obtained by dehydrating and condensing a carboxylic acid and/or an acid anhydride such as an aliphatic, alicyclic, aromatic dicarboxylic acid or polycarboxylic acid or the corresponding acid anhydride thereof and the like selected from one or more of succinic acid, methylsuccinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, nonane dicarboxylic acid, decane dicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, cyclohexane dicarboxylic acid, maleic acid, fumaric acid, malonic acid, trimellitic acid, phthalic anhydride, trimellitic anhydride, succinic anhydride; the polyhydric alcohol is selected from one or more of ethylene glycol, diethylene glycol, 1, 2-propylene glycol, 1, 3-propylene glycol, 1, 4-butanediol, 1, 3-butanediol, 2, 3-butanediol, 1, 5-pentanediol, neopentyl glycol, 1, 6-hexanediol, 2-dimethyl-1, 3-propanediol, 1, 4-dihydroxycyclohexane, 1, 4-dimethylolcyclohexane, 1, 8-octanediol, 1, 10-decanediol and 1, 12-dodecanediol;

more preferably, the polyether polyol is a polyaddition product of styrene oxide, or a polyaddition product of ethylene oxide, propylene oxide, tetrahydrofuran, butylene oxide, epichlorohydrin and the like as monomers; or polyether polyols obtained by polycondensation of polyols or mixtures thereof; or polyether polyols obtained by alkoxylation of polyols, amines and amino alcohols, more preferably polyoxyethylene polyols, polyoxypropylene polyols; polyoxypropylene ether glycols are particularly preferred.

4. The aqueous polyurethane dispersion according to any one of claims 1 to 3, wherein the polyisocyanate of component c) is selected from aromatic, aliphatic or cycloaliphatic polyisocyanates, preferably one or more of aromatic, aliphatic or cycloaliphatic isocyanates having two isocyanate groups, more preferably diisocyanate Y (NCO)₂Wherein 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;

preferably, 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;

further preferably, the diisocyanate is a mixture of aliphatic and alicyclic diisocyanates, more preferably a mixture of hexamethylene diisocyanate and one or more of 1, 4-cyclohexane diisocyanate, isophorone diisocyanate, 4 '-dicyclohexylmethane diisocyanate and 4,4' -dicyclohexylpropane diisocyanate, and particularly preferably a mixture of hexamethylene diisocyanate and isophorone diisocyanate; and/or

Component d) the hydrophilic compound is a compound containing 2 to 3 NCO reactive groups and at least one ionic or potentially ionic group, preferably di-or trihydroxycarboxylic acid, di-or trihydroxysulfonic acid, di-or triamino sulfonic acid, di-or triamino carboxylic acid or salts thereof, more preferably dimethylolpropionic acid, dimethylolbutyric acid, dimethylolacetic acid, dihydroxysuccinic acid, N- (2-aminoethyl) -2-aminoethanesulfonic acid, N- (3-aminopropyl) -3-aminopropanesulfonic acid, N- (2-aminoethyl) -B-alanine and alkali metal or ammonium salts of the above compounds, most preferably N- (2-aminoethyl) -2-aminoethane sulfonate and/or N- (2-aminoethyl) -B-alaninate;

preferably, when the component d) is a potentially ionic compound, a neutralizing agent is added, wherein the neutralizing agent is selected from one or more of alkali metal compounds and alkaline earth metal compounds, and is preferably selected from one or more of sodium hydroxide, potassium hydroxide, lithium hydroxide or calcium hydroxide; and/or

The component f) is a compound containing 1-3 amino groups, wherein the amino groups are primary amino groups and/or secondary amino groups;

preferably, the compound containing 1 to 3 amino groups is diamine and/or triamine, preferably one or more of 1, 2-ethylenediamine, hydroxyethylethylenediamine, 1, 6-hexamethylenediamine, 1-amino-3, 3, 5-trimethyl-5-aminomethylcyclohexane (isophoronediamine), N-aminoethylpiperazine, 1, 4-diaminocyclohexane, bis- (4-aminocyclohexyl) methane and diethylenetriamine, adipic acid dihydrazide, and hydrazine hydrate; more preferably one or more of isophoronediamine, hydroxyethylethylenediamine and N-aminoethylpiperazine.

5. The aqueous polyurethane dispersion according to any one of claims 1 to 4, wherein component e) is the C-containing polyurethane dispersion₁₀～C₂₅The amino compound of the hydrophobic chain segment has a structure shown in a formula I:

wherein R is C₁₀-C₂₅Alkyl groups of (a);

wherein R is as defined for formula I and Y is H or-CH₃；

6. The aqueous polyurethane dispersion according to claim 5, wherein the C-containing component is a polyol₁₀-C₂₅The preparation method of amino compound with hydrophobic chain segment is characterized by that it uses diethylenetriamine, ester shown in formula II and alkali and solventMixing the reagents, and heating to carry out Michael addition reaction to obtain the catalyst;

preferably, the base is selected from triethylamine, sodium ethoxide, sodium hydride and sodium amide, and the amount of the base is 1.5-2.5 times of the mass of diethylenetriamine;

preferably, the solvent is selected from dioxane, tetrahydrofuran, methyl tert-butyl ether; the using amount of the solvent is 50-100 times of the mass of the diethylenetriamine;

preferably, the Michael addition reaction temperature is 50-80 ℃, preferably 65-75 ℃, and the time is 2-4 hours, preferably 3-4 hours.

7. The aqueous polyurethane dispersion according to any one of claims 1 to 6, characterised in that it comprises a solids content of 30 to 70 wt.%, preferably 40 to 50 wt.%, the remainder being water; the average particle size is 100-300 nm, preferably 150-250 nm;

the pH value of the aqueous polyurethane dispersion is 4-11, preferably 7-9.

8. A method for preparing the aqueous polyurethane dispersion according to any one of claims 1 to 7, comprising the steps of:

3) adding a component e) dissolved by a solvent into the aqueous polyurethane dispersion 1 to carry out chain extension reaction, and then removing the solvent by reduced pressure distillation to obtain the aqueous polyurethane dispersion.

9. The process according to claim 8, wherein in steps 1) to 3), the solvent is a solvent which can be partially or completely removed by distillation during or after dispersion, and is selected from one or more of acetone, methyl isobutyl ketone, butanone, tetrahydrofuran, dioxane, acetonitrile, dipropylene glycol dimethyl ether, 1-methyl-2-pyrrolidone, preferably acetone and/or butanone, more preferably acetone; the solvents in step 1) and step 2) may be the same or different;

preferably, the adding amount of the solvent in the step 1) is 0.05 to 0.3 time, preferably 0.1 to 0.2 time of the total mass of the solid parts added in the step 1); the adding amount of the solvent in the step 2) is 1-3 times, preferably 1.2-2.2 times of the total mass of the solid components added in the step 1); in the step 3), the concentration of the acetone-soluble component e) is 20-30 wt%; and/or

In the step 1), the reaction temperature is 70-90 ℃, preferably 75-85 ℃; the time is 1 to 3 hours, preferably 1.5 to 2.5 hours; the reaction is carried out under the protection of inert gas, and the inert gas is preferably nitrogen;

the reaction is carried out in the presence of a catalyst selected from triethylamine, 1, 4-diazabicyclo- [2,2,2] -octane, dibutyltin oxide, tin dioctoate or dibutyltin dilaurate, tin bis- (2-ethylhexanoate), bismuth neodecanoate, bismuth 2-ethylhexanoate, preferably bismuth neodecanoate, bismuth 2-ethylhexanoate, more preferably bismuth neodecanoate;

preferably, the amount of the catalyst is 0.003-0.03% of the total mass of the components a), b) and c); and/or

In the step 2), the chain extension reaction is carried out at the temperature of 30-50 ℃, preferably 35-45 ℃; the time is 1-30 min, preferably 10-15 min;

after the water is added for dispersion, the solid content of the aqueous polyurethane dispersion 1 is 40-50 wt%; and/or

In the step 3), the chain extension reaction is carried out at room temperature for 1-30 min, preferably 5-10 min;

in the reduced pressure distillation process, the vacuum degree is 0.07-0.1 MPa, and the temperature is 35-55 ℃.

10. The bi-component spray glue is characterized by comprising the following components in parts by weight:

component A): 100 parts of an aqueous polyurethane dispersion;

component B): 4-10 parts of curing agent, preferably 6-8 parts;

the aqueous polyurethane dispersion is the aqueous polyurethane dispersion as described in any one of claims 1 to 7 or the aqueous polyurethane dispersion prepared by the method as described in claim 8 or 9;

preferably, the curing agent is selected from salt solution containing metal ions, preferably CaCl with the concentration of 2-5 wt%₂Aqueous solution and/or ZnSO₄An aqueous solution.