An easily thickened polyurethane or polyurethane-urea aqueous dispersion and its preparation method and application

Abstract

The present invention belongs to the technical field of waterborne polyurethane dispersion, and specifically relates to a polyurethane or polyurethane-urea water dispersion that is easy to thicken, and a preparation method and application thereof, wherein the polyurethane or polyurethane-urea water dispersion is obtained by reacting the following components: (a) polymer polyol; (b) isocyanate; (c) monofunctional polyether, which is a block copolymer obtained by reacting component c1, component c2 and component c2; wherein component c1 is an alcohol; component c2 is an alkylene oxide of C3 and above; component c3 is ethylene oxide; and the three different polymer segments contained in the block copolymer are arranged in the order of c1-c2-c3; (d) a hydrophilic compound containing 2 to 3 NCO reactive groups; (e) a small molecule compound containing amino and / or hydroxyl groups having a functionality of 1 to 3. The polyurethane or polyurethane-urea water dispersion obtained by the present invention can optimize the thickening ability of a water dispersion emulsion without substantially affecting other properties of the emulsion.

Description

Technical Field

[0001] The invention belongs to the technical field of waterborne polyurethane dispersions, and in particular relates to an easily thickened polyurethane or polyurethane-urea water dispersion and a preparation method and application thereof. Background Art

[0002] Waterborne polyurethane dispersions are used in all aspects of life, such as adhesives, industrial paints, synthetic leather, etc., due to their excellent mechanical properties, environmental friendliness, and low price.

[0003] Waterborne polyurethane dispersion is a polyurethane dispersed in water using an emulsifier, but this is not a very stable state. In order to extend the stability time, a large amount of emulsifier is often needed. However, the increase in the amount of emulsifier added will require more thickeners to reach the required viscosity range in the later thickening process of the emulsion, which undoubtedly increases the cost of use.

[0004] Patent document WO 2011 / 128382 discloses that the thickening ability is improved by removing the solvent acetone during the emulsion dispersion process; however, such an operation often results in a wide particle size distribution of the emulsion and difficult phase transition.

[0005] Patent document CN101848952A discloses that the introduction of monofunctional polyether is removed in the preparation of the emulsion. Although such operation improves the thickening ability of the emulsion to a certain extent, it makes the low-temperature storage and anti-skinning properties of the emulsion worse.

[0006] Other researchers have also tried to alleviate the thickening problem by increasing the molecular weight of polyurethane to reduce the proportion of the emulsified section, but this requires more solvent during the dispersion process to compensate for the high dispersion viscosity, which is not a good solution.

[0007] In view of this, how to improve the thickening ability of the emulsion without affecting other properties of the emulsion is a direction worthy of further research. Summary of the invention

[0008] The purpose of the present invention is to provide an easily thickened polyurethane or polyurethane-urea aqueous dispersion and a preparation method and application thereof, in view of the problems existing in the thickening of the existing polyurethane emulsion. By selecting a block copolymer with a specific polymer segment arrangement as a monofunctional polyether component, the thickening ability of the aqueous dispersion emulsion can be optimized without substantially affecting other properties of the emulsion. The preparation method is simple to operate, low in cost, and has a wide range of practical applications.

[0009] In order to achieve the above object, the present invention provides the following technical solutions:

[0010] In a first aspect, a polyurethane or polyurethane-urea aqueous dispersion that is easily thickened is provided, wherein the polyurethane or polyurethane-urea is obtained by reacting the following components:

[0011] (a) polymer polyols having a functionality of 2 to 4 (e.g., 2.5, 3, 3.5);

[0012] (b) isocyanates;

[0013] (c) a monofunctional polyether, which is a block copolymer obtained by reacting component c1, component c2 and component c3; wherein component c1 is an alcohol; component c2 is an alkylene oxide of C3 or above; and component c3 is ethylene oxide;

[0014] And, the three different polymer segments contained in the block copolymer are arranged in the order of c1-c2-c3;

[0015] (d) a hydrophilic compound containing 2 to 3 NCO reactive groups, which further comprises an ionic group and / or a potential ionic group;

[0016] (e) Small molecule compounds containing amino groups and / or hydroxyl groups with a functionality of 1 to 3 (eg, 2).

[0017] Herein, the arrangement order of the three different polymer segments contained in the block copolymer is c1-c2-c3, which can be understood as the arrangement order of the structural units contributed by the components c1-c2-c3.

[0018] According to the polyurethane or polyurethane-urea aqueous dispersion provided by the present invention, in some embodiments, the amount of each component is as follows, based on the total weight of each component:

[0019] The amount of component (a) is 50 to 90 wt% (e.g., 55 wt%, 60 wt%, 70 wt%, 80 wt%, 85 wt%), preferably 75 to 90 wt%;

[0020] The amount of component (b) is 5 to 40 wt% (e.g., 6 wt%, 12 wt%, 15 wt%, 20 wt%, 25 wt%), preferably 10 to 30 wt%;

[0021] The amount of component (c) is 0.5 to 5 wt% (e.g., 0.6 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, 4.0 wt%), preferably 0.8 to 3.0 wt%;

[0022] The amount of component (d) is 0.2 to 20 wt% (e.g., 0.3 wt%, 0.5 wt%, 1.5 wt%, 2.0 wt%, 3.0 wt%, 4.0 wt%, 10 wt%, 15 wt%), preferably 1 to 5 wt%;

[0023] The amount of component (e) is 0.05 to 5 wt% (e.g., 0.1 wt%, 0.4 wt%, 0.8 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, 4.0 wt%), preferably 0.5 to 3 wt%.

[0024] According to the polyurethane or polyurethane-urea aqueous dispersion provided by the present invention, in some embodiments, the polymer polyol is selected from one or more polymer diols with a number average molecular weight of 600-4000 (for example, 650, 700, 1000, 1500, 2000, 2500, 3000, 3500), preferably selected from aliphatic linear or slightly branched polyester polyols or polycarbonate polyols, more preferably selected from polyester diols prepared by reacting one or more of 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and neopentyl glycol with adipic acid.

[0025] In some embodiments, the isocyanate is a diisocyanate, preferably selected from one or more of hexamethylene diisocyanate, dodecamethylene diisocyanate, isophorone diisocyanate, 1,4-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 4,4'-dicyclohexylpropane diisocyanate, 1,4-toluene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, tetramethylxylene diisocyanate and p-xylylene diisocyanate; more preferably selected from one or more of hexamethylene diisocyanate, isophorone diisocyanate and 2,6-toluene diisocyanate.

[0026] In some embodiments, in the block copolymer of component (c):

[0027] Component c1 is selected from one or more of methanol, ethanol, propanol, butanol, pentanol, hexanol, octanol, nonanol, decanol and dodecanol, preferably butanol;

[0028] Component c2 is selected from one or more of propylene oxide, butylene oxide and 1,2-dimethylethylene oxide, preferably propylene oxide;

[0029] Component c3 is ethylene oxide.

[0030] In some embodiments, in the block copolymer of component (c), the mass ratio of component c3 (ethylene oxide) to component c2 (such as propylene oxide, etc.) is (50-100):(50-10), for example, 10:1, 8:1, 6:1, 4:1, 2:1, 1:1, preferably (75-100):(25-10), and more preferably (80-90):(10-20).

[0031] In the block copolymer of component (c), the percentage of ethoxy structural units contributed by ethylene oxide is 50-90wt%, for example, 60wt%, 66wt%, 70wt%, 75wt%, 80wt%, 85wt%.

[0032] In some embodiments, component (c) has a number average molecular weight of 800-3000 (e.g., 900, 1000, 1250, 1400, 1600, 1800, 2000, 2800), preferably 1200-2500.

[0033] In some embodiments, component (c) further includes monofunctional ethylene oxide homopolyether (such as MPEG1200), that is, component (c) can be a compound mixture of monofunctional block copolymer polyether and monofunctional ethylene oxide homopolyether.

[0034] In some embodiments, component (d) is selected from hydrophilic compounds containing ionic groups and 2-3 NCO reactive functional groups and / or hydrophilic compounds containing potential ionic groups and 2-3 NCO reactive functional groups; wherein:

[0035] In some embodiments, the NCO reactive groups are amino groups and / or hydroxyl groups.

[0036] The ionic group can be, for example, a sulfonate and / or a carboxylate; the potential ionic group is a sulfonic acid group and / or a carboxylic acid group. In some embodiments, the ionic group and / or potential ionic group is selected from one or more of dihydroxycarboxylic acids and their salts, trihydroxycarboxylic acids and their salts, dihydroxysulfonic acids and their salts, trihydroxysulfonic acids and their salts, diaminosulfonic acids and their salts, triaminosulfonic acids and their salts, diaminocarboxylic acids and their salts, and triaminocarboxylic acids and their salts, preferably selected from one or more of dihydroxymethylacetic acid and its alkali metal salt and / or ammonium salt, dihydroxymethylpropionic acid and its alkali metal salt and / or ammonium salt, dihydroxymethylbutyric acid and its alkali metal salt and / or ammonium salt, N-(2-aminoethyl)-2-aminoethanesulfonic acid and its alkali metal salt and / or ammonium salt, N-(3-aminopropyl)-2-aminoethanesulfonic acid and its alkali metal salt and / or ammonium salt, N-(2-aminoethyl)-2-aminobutanesulfonic acid and its alkali metal salt and / or ammonium salt, and N-(2-aminoethyl)-3-aminopropanesulfonic acid and its alkali metal salt and / or ammonium salt.

[0037] In some embodiments, component (e) is an aliphatic small molecule compound having a functionality of 1-3 and containing a primary or secondary amino group; preferably one or more selected from isophoronediamine, 1,6-hexamethylenediamine, N-(2-hydroxyethyl)ethylenediamine, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and diethanolamine.

[0038] In some embodiments, the solid content of the polyurethane or polyurethane-urea aqueous dispersion is 10-74wt% (e.g., 15wt%, 30wt%, 50wt%, 65wt%), preferably 40-60wt%; the pH value of the polyurethane or polyurethane-urea aqueous dispersion is 6-9 (e.g., 6.5, 7.5, 8.5), preferably 7-8.

[0039] In a second aspect, a method for preparing the polyurethane or polyurethane-urea aqueous dispersion as described above is provided, comprising the steps of:

[0040] Components (a), (b) and (c) are mixed and polymerized to form a prepolymer with terminal isocyanate; components (d) and (e) are reacted with the prepolymer, and then dispersed with water to finally obtain a polyurethane or polyurethane-urea aqueous dispersion.

[0041] In some examples, the system can be diluted by adding a solvent, and the solvent can be partially or completely removed by distillation during or after the dispersion. For example, a water-miscible solvent that is inert to isocyanate groups can be optionally added during the reaction for dilution. Suitable solvents can 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 polymerization reaction. It can also be added in batches. The solvent is preferably acetone and butanone, more preferably acetone. The optional solvent, such as acetone, is distilled off during and / or after the dispersion.

[0042] During the reaction, the NCO content of the reaction mixture is usually followed to monitor the degree of conversion. This can be accomplished by spectroscopic measurements (e.g., infrared or near infrared spectra, determination of the refractive index) and chemical potentiometric titration (e.g., chemical titration by taking out a sample).

[0043] The reaction temperature in the prepolymerization stage is 50-150°C (e.g., 60°C, 70°C, 80°C, 90°C, 100°C, 120°C). The reaction temperature of the chain extension reaction after the prepolymerization can be, for example, 25-60°C (e.g., 30°C, 40°C, 50°C); the reaction time can be, for example, 20-60 min (e.g., 30 min, 40 min).

[0044] In a third aspect, there is provided a polyurethane or polyurethane-urea aqueous dispersion as described above or a polyurethane or polyurethane-urea aqueous dispersion prepared by the preparation method as described above, and its use in the field of adhesives and synthetic leather.

[0045] The polyurethane or polyurethane-urea aqueous dispersion prepared by the present invention can be used alone or together with known auxiliary substances and additives (in coating and adhesive technology). Commonly used auxiliary substances and additives include, for example, emulsifiers, light stabilizers, antioxidants, fillers, anti-settling agents, defoamers, wetting agents, flow regulators, reactive diluents, plasticizers, neutralizers, catalysts, auxiliary solvents, thickeners, pigments, dyes, matting agents, tackifiers, etc.

[0046] Auxiliary substances and additives can be added before or after polymerization. Of course, auxiliary substances and additives can also be added after dispersion.

[0047] The prepared polyurethane or polyurethane-urea aqueous dispersion and the adhesive or binder composition based thereon are suitable for bonding any substrate. These substrates, for example, all types of metals, alloys, wood, wood-based materials, particle boards, MDF boards, ceramics, stones, concrete, asphalt, hard fibers, glass fibers, carbon fibers, carbon nanotubes, porcelain, leather, textiles and inorganic materials, etc. They are also suitable for bonding rubber materials, various plastics, etc. They are also suitable for bonding thermoplastics.

[0048] The adhesives of the prepared aqueous polyurethane or polyurethane-urea dispersions are likewise suitable for articles produced therefrom.

[0049] The thickening mechanism of waterborne polyurethane emulsion is that the hydrophobic groups of the polyurethane thickener associate with the hydrophobic parts of the surface of the waterborne polyurethane emulsion particles through hydrophobic association, causing the viscosity of the system to increase, thereby achieving the purpose of thickening the waterborne polyurethane dispersion. Although the waterborne polyurethane dispersion prepared by using the traditional monofunctional ethylene oxide homopolymer (such as MPEG1200) as a raw material can increase the ionic stability and freeze-thaw stability of the waterborne polyurethane, the ethoxy structural units contained have good water solubility, resulting in the polyethoxy units being completely dissolved in water. The chain segments are distributed on the surface of the waterborne polyurethane particles, which will reduce the association between the hydrophobic groups of the polyurethane thickener and the hydrophobic parts of the surface of the waterborne polyurethane emulsion particles, thereby reducing the thickening efficiency.

[0050] Compared with the prior art, the present invention modifies component c) in the formula. Compared with the traditional monofunctional ethylene oxide homopolymer polyether without component c2, the introduction of component c2 into the block copolymer monofunctional polyether can reduce the polarity and hydrophilicity of the ethoxy structural units contained therein. At the same time, because component c2 also contains alkoxy groups, the compatibility between the waterborne polyurethane emulsion particles and the polyurethane thickener molecules is improved. In addition, the block copolymerization method is selected and the structural units contributed by the components c1-c2-c3 are arranged in the order of c1-c2-c3, which can reduce the hydrophilicity of the polyethoxy group and increase the interaction between the terminal molecular chain and the thickener molecule; therefore, the modification of the component (c) in the formula can reduce the adverse effect of the polyethoxy unit on the association efficiency of the hydrophobic group of the polyurethane thickener and the hydrophobic part of the surface of the waterborne polyurethane particle, and at the same time, the hydrophobicity of the c2 group contained in the component (c) can also increase the association between the latex particles and the polyurethane thickener molecules. The combination of these two effects can significantly improve the thickening efficiency of the waterborne polyurethane or polyurethane-urea.

[0051] The beneficial effects of the technical solution of the present invention are:

[0052] Under the same thickener dosage, the use of component (c) with a special structure and composition to prepare an aqueous polyurethane dispersion can significantly improve the thickening efficiency of the aqueous polyurethane dispersion, thereby achieving a low initial viscosity of the product, and the thickening efficiency and thickening effect both meet the use requirements, and can also significantly reduce production costs and construction costs, while having no negative impact on other application properties (such as adhesion, heat resistance, etc.). DETAILED DESCRIPTION

[0053] In order to understand the technical features and contents of the present invention in detail, the preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described in the embodiments, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described here.

[0054] <Source of raw materials>

[0055] Polybutylene adipate diol, OH value = 56 mg KOH / g (WHP-204, Wanhua Chemical);

[0056] Polybutylene adipate diol, OH value = 40 mg KOH / g (WHP-104, Wanhua Chemical);

[0057] Hexamethylene diisocyanate (Wannate@R HDI, Wanhua Chemical);

[0058] Isophorone diisocyanate (Wannate@R IPDI, Wanhua Chemical);

[0059] Monofunctional polyethoxy ether, number average molecular weight 1200 (MPEG1200, LOTTE CHEM);

[0060] Monofunctional polyether I, a block copolymer of ethylene oxide and propylene oxide with butanol as the initiator, with a number average molecular weight of 2100 and ethylene oxide accounting for 85% by mass, Cologne Fine Chemicals;

[0061] Monofunctional polyether II, a block copolymer of ethylene oxide and propylene oxide with butanol as the initiator, with a number average molecular weight of 1800 and ethylene oxide accounting for 50% by mass, Cologne Fine Chemicals;

[0062] Monofunctional polyether III, a block copolymer of ethylene oxide and propylene oxide with butanol as the initiator, with a number average molecular weight of 1900 and ethylene oxide accounting for 65% by mass, Cologne Fine Chemicals;

[0063] Monofunctional polyether IV, a block copolymer of ethylene oxide and propylene oxide with butanol as the initiator, with a number average molecular weight of 1800 and ethylene oxide accounting for 95% by mass, Cologne Fine Chemicals;

[0064] Sodium N-(2-aminoethyl)-2-aminoethanesulfonate (Vestamin A95), Evonik;

[0065] Hydroxyethylethylenediamine, namely N-(2-hydroxyethyl)ethylenediamine, BASF-Yangzi;

[0066] Isophorone diamine (IPDA), Wanhua Chemical;

[0067] Defoamer BYK024, BYK Chemical;

[0068] Emulsifier Tween 20, Shanghai Bangjing Industrial.

[0069] Example 1

[0070] 228 g of dehydrated WHP-104, 155 g of WHP-204, 11 g of monofunctional polyether I, 65.7 g of HDI and 1.7 g of IPDI were added to a nitrogen-treated anhydrous four-necked flask, and 80 g of acetone was added and mixed, and the reaction system was gradually heated to 70-80° C. and the mixture was stirred to react until the residual NCO content reached 1.24%, thereby obtaining a prepolymer;

[0071] The prepolymer is dissolved in 700 g of acetone and cooled to about 50° C.; 20 g of an aqueous solution containing 7.93 g of sodium N-(2-aminoethyl)-2-aminoethanesulfonate, 1.4 g of isophorone diamine and 1.8 g of hydroxyethylethylenediamine is added to the prepolymer diluted with the solvent and stirred vigorously; the mixture is stirred for 20 minutes, and then 566 g of dispersion water is added and dispersed by high-speed stirring to obtain an aqueous dispersion; after removing acetone from the system by distillation, 7.4 g of an emulsifier Tween 20 is added; thus, a solvent-free polyurethane or polyurethane-urea aqueous dispersion is obtained, the solid content of which is 48 wt %, and the average particle size of which is 165 nm as measured by a Malvern particle size analyzer.

[0072] Example 2

[0073] 228 g of dehydrated WHP-104, 155 g of WHP-204, 5.5 g of monofunctional polyether I, 65.7 g of HDI and 1.7 g of IPDI were added to a nitrogen-treated anhydrous four-necked flask, and 80 g of acetone was added and mixed, and the reaction system was gradually heated to 70-80° C. and the mixture was stirred to react until the residual NCO content reached 1.24%, thereby obtaining a prepolymer;

[0074] The prepolymer is dissolved in 700 g of acetone and cooled to about 50° C.; 20 g of an aqueous solution containing 11.00 g of sodium N-(2-aminoethyl)-2-aminoethanesulfonate and 1.8 g of hydroxyethylethylenediamine is added to the prepolymer diluted with the solvent and stirred vigorously; the mixture is stirred for 20 minutes, and then 566 g of dispersion water is added and dispersed with high-speed stirring to obtain an aqueous dispersion; after removing acetone from the system by distillation, 7.4 g of an emulsifier Tween 20 is added; thus, a solvent-free polyurethane or polyurethane-urea aqueous dispersion is obtained, the solid content of which is 48 wt %, and the average particle size of which is 166 nm as measured by a Malvern particle size analyzer.

[0075] Example 3

[0076] 228 g of dehydrated WHP-104, 155 g of WHP-204, 4.3 g of MPEG1200, 5.5 g of monofunctional polyether I, 65.7 g of HDI and 1.7 g of IPDI were added to a nitrogen-treated anhydrous four-necked flask, and 80 g of acetone was added and mixed, and the reaction system was gradually heated to 70-80° C. and the mixture was stirred for reaction until the residual NCO content reached 1.24%, thereby obtaining a prepolymer;

[0077] The prepolymer is dissolved in 700 g of acetone and cooled to about 50° C.; 20 g of an aqueous solution containing 7.93 g of sodium N-(2-aminoethyl)-2-aminoethanesulfonate, 1.4 g of isophorone diamine and 1.8 g of hydroxyethylethylenediamine is added to the prepolymer diluted with the solvent and stirred vigorously; the mixture is stirred for 20 minutes, and then 566 g of dispersion water is added and dispersed with high-speed stirring to obtain an aqueous dispersion; after removing acetone from the system by distillation, 7.4 g of an emulsifier Tween 20 is added; thus, a solvent-free polyurethane or polyurethane-urea aqueous dispersion is obtained, the solid content of which is 48 wt %, and the average particle size of which is 176 nm as measured by a Malvern particle size analyzer.

[0078] Example 4

[0079] 228 g of dehydrated WHP-104, 155 g of WHP-204, 8.5 g of monofunctional polyether I, 65.7 g of HDI and 1.7 g of IPDI were added to a nitrogen-treated anhydrous four-necked flask, and 80 g of acetone was added and mixed, and the reaction system was gradually heated to 70-80° C. and the mixture was stirred for reaction until the residual NCO content reached 1.24%, thereby obtaining a prepolymer;

[0080] The prepolymer is dissolved in 700 g of acetone and cooled to about 50° C.; 20 g of an aqueous solution containing 9.5 g of sodium N-(2-aminoethyl)-2-aminoethanesulfonate, 0.7 g of isophorone diamine and 1.8 g of hydroxyethylethylenediamine is added to the prepolymer diluted with the solvent and stirred vigorously; the mixture is stirred for 20 minutes, and then 566 g of dispersion water is added and dispersed with high-speed stirring to obtain an aqueous dispersion; after removing acetone from the system by distillation, 7.4 g of an emulsifier Tween 20 is added; thus, a solvent-free polyurethane or polyurethane-urea aqueous dispersion is obtained, the solid content of which is 48 wt %, and the average particle size of which is 160 nm as measured by a Malvern particle size analyzer.

[0081] Example 5

[0082] 228 g of dehydrated WHP-104, 155 g of WHP-204, 13 g of monofunctional polyether III, 65.7 g of HDI and 1.7 g of IPDI were added to a nitrogen-treated anhydrous four-necked flask, 80 g of acetone was added and mixed, and the mixture was gradually heated to 70-80° C. and stirred to react until the residual NCO content reached 1.24%, thereby obtaining a prepolymer;

[0083] The prepolymer is dissolved in 700 g of acetone and cooled to about 50° C.; 20 g of an aqueous solution containing 7.93 g of sodium N-(2-aminoethyl)-2-aminoethanesulfonate, 1.4 g of isophorone diamine and 1.8 g of hydroxyethylethylenediamine is added to the prepolymer diluted with the solvent and stirred vigorously; the mixture is stirred for 20 minutes, and then 566 g of dispersion water is added and dispersed with high-speed stirring to obtain an aqueous dispersion; after removing acetone from the system by distillation, 7.4 g of an emulsifier Tween 20 is added; thus, a solvent-free polyurethane or polyurethane-urea aqueous dispersion is obtained, the solid content of which is 48 wt %, and the average particle size of which is 159 nm as measured by a Malvern particle size analyzer.

[0084] Example 6

[0085] 228 g of dehydrated WHP-104, 155 g of WHP-204, 15 g of monofunctional polyether II, 65.7 g of HDI and 1.7 g of IPDI were added to a nitrogen-treated anhydrous four-necked flask, and 80 g of acetone was added and mixed, and the reaction system was gradually heated to 70-80° C. and the mixture was stirred to react until the residual NCO content reached 1.24%, thereby obtaining a prepolymer;

[0086] The prepolymer is dissolved in 700 g of acetone and cooled to about 50° C.; 20 g of an aqueous solution containing 7.93 g of sodium N-(2-aminoethyl)-2-aminoethanesulfonate, 1.4 g of isophorone diamine and 1.8 g of hydroxyethylethylenediamine is added to the prepolymer diluted with the solvent and stirred vigorously; the mixture is stirred for 20 minutes, and then 566 g of dispersion water is added and dispersed with high-speed stirring to obtain an aqueous dispersion; after removing acetone from the system by distillation, 7.4 g of an emulsifier Tween 20 is added; thus, a solvent-free polyurethane or polyurethane-urea aqueous dispersion is obtained, the solid content of which is 48 wt %, and the average particle size of which is 163 nm as measured by a Malvern particle size analyzer.

[0087] Comparative Example 1

[0088] 228 g of dehydrated WHP-104, 155 g of WHP-204, 8.6 g of MPEG1200, 65.7 g of HDI and 1.7 g of IPDI were added into a nitrogen-treated anhydrous four-necked flask, and 80 g of acetone was added and mixed, and the reaction system was gradually heated to 70-80° C. and the mixture was stirred for reaction until the residual NCO content reached 1.24%, thereby obtaining a prepolymer;

[0089] The prepolymer is dissolved in 700 g of acetone and cooled to about 50° C.; 20 g of an aqueous solution containing 7.93 g of sodium N-(2-aminoethyl)-2-aminoethanesulfonate, 1.4 g of isophorone diamine and 1.8 g of hydroxyethyl ethylenediamine is added to the prepolymer diluted with the solvent and stirred vigorously; the mixture is stirred for 20 minutes, and then 566 g of dispersion water is added and dispersed with high-speed stirring to obtain an aqueous dispersion; after removing acetone from the system by distillation, 7.4 g of an emulsifier Tween 20 is added; thus, a solvent-free polyurethane or polyurethane-urea aqueous dispersion is obtained, the solid content of which is 48 wt %, and the average particle size of which is 160 nm as measured by a Malvern particle size analyzer.

[0090] Comparative Example 2

[0091] 228 g of dehydrated WHP-104, 155 g of WHP-204, 10 g of monofunctional polyether IV, 65.7 g of HDI and 1.7 g of IPDI were added to a nitrogen-treated anhydrous four-necked flask, and 80 g of acetone was added and mixed, and the reaction system was gradually heated to 70-80° C. and the mixture was stirred to react until the residual NCO content reached 1.24%, thereby obtaining a prepolymer;

[0092] The prepolymer is dissolved in 700 g of acetone and cooled to about 50° C.; 20 g of an aqueous solution containing 7.93 g of sodium N-(2-aminoethyl)-2-aminoethanesulfonate, 1.4 g of isophorone diamine and 1.8 g of hydroxyethyl ethylenediamine is added to the prepolymer diluted with the solvent and stirred vigorously; the mixture is stirred for 20 minutes, and then 566 g of dispersion water is added and dispersed with high-speed stirring to obtain an aqueous dispersion; after removing acetone from the system by distillation, 7.4 g of an emulsifier Tween 20 is added; thus, a solvent-free polyurethane or polyurethane-urea aqueous dispersion is obtained, the solid content of which is 48 wt %, and the average particle size of which is 168 nm as measured by a Malvern particle size analyzer.

[0093] Thickening experiment

[0094] Under stirring, add sodium sulfate aqueous solution to 200g of the aqueous dispersion emulsion prepared in each of the above examples and comparative examples, adjust to make the viscosity of each corresponding mixture similar, and then add 0.4g of Vesmody U604 thickener, stir at a speed of 500rpm for 1-2min, then increase the speed to 2000rpm and stir for 5min; then leave it for a while to obtain each test sample, and perform viscosity test. Viscosity test: Test each sample by a Brooke viscometer (RV), #63 rotor / 12rpm.

[0095] Adhesive preparation

[0096] 100 g of the polyurethane or polyurethane-urea aqueous dispersion prepared in the above embodiments and comparative examples and 0.05 g of BYK024 (BYK Chemical) were mixed, stirred at 500 rpm for 5 min, 0.2 g of Tego245 (Tego) was added, stirred for 5 min, 0.15 g of Vesmody U604 (Wanhua Chemical) was added, and then stirred at 600 rpm for 10 min to obtain the corresponding adhesives.

[0097] Preparation and testing of test specimens

[0098] (1) Preparation of composite materials used for testing:

[0099] First, a PVC substrate strip was selected and polished. Then, each adhesive prepared as above was applied thinly to a 2.5 cm wide and 15 cm long substrate strip using a brush and dried in an oven at 65°C for 3 minutes. Then, the strip was taken out and passed through a hot press at 30 kg / cm 2 The composite materials were pressed for 10 seconds under the above conditions to obtain the corresponding composite materials.

[0100] (2) Peel strength of composite materials

[0101] The peel strength of each corresponding composite material was measured using a GOTECH tensile testing machine at a peeling rate of 200 mm / min.

[0102] Initial strength: After pressing, the peel strength is tested directly on the tensile machine. Later strength: After the specimen is placed at room temperature for 24 hours, the peel strength is tested. The test data are shown in Table 1.

[0103] (3) Heat resistance of composite materials

[0104] Initial heat resistance: Hang a 500-gram weight on each test sample, place it in an 80°C oven, and test the length of the sample that can be pulled apart within 30 minutes.

[0105] Later heat resistance: After the prepared samples are placed at room temperature for 3 days, hang a 1 kg weight on them and place them in a 70°C oven to test the length of the sample pulled apart within 24 hours.

[0106] The test data are shown in Table 1.

[0107] Table 1 Thickening properties of the test samples corresponding to the embodiments and comparative examples

[0108]

[0109]

[0110] Table 2 Performance test results of composite materials samples corresponding to each embodiment and comparative example

[0111]

[0112] From the results in Table 1 and Table 2, we can see that:

[0113] 1) Comparing the examples with the comparative examples, the polyurethane or polyurethane-urea aqueous dispersion prepared by the present invention can significantly improve its thickening efficiency; that is, when mixed with the same amount of thickener, the polyurethane or polyurethane-urea aqueous dispersion prepared by the present invention has a higher thickening efficiency.

[0114] 2) Comparison of Examples 1, 2 and 4 shows that reducing the amount of component (c) within a certain range can also improve the thickening efficiency of the aqueous dispersion, but since a reduction in the amount of component (c) added can affect the initial viscosity and other properties, the amount added must be controlled within an appropriate range;

[0115] 3) Comparison of Comparative Example 1 with Examples 6, 5, and 1 shows that as the content of the ethoxy structural unit in component (c) decreases, the thickening efficiency of the aqueous dispersion increases. However, since the content of the ethoxy group has an effect on the performance of the emulsion ion stability, the content of the ethoxy structural unit in component (c) must be within a suitable range;

[0116] 4) Comparison between Comparative Example 2 and Example 1 shows that when the content of ethoxy structural units in component (c) is increased to 95 wt %, the thickening efficiency is significantly reduced.

[0117] The above describes some embodiments of the present invention, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. An easily thickened polyurethane or polyurethane-urea aqueous dispersion, characterized in that: The polyurethane or polyurethane-urea is obtained by reacting the following components: (a) polymer polyols having a functionality of 2 to 4; (b) isocyanates; (c) a monofunctional polyether, which is a block copolymer prepared by reacting component c1, component c2 and component c3; wherein component c1 is an alcohol; component c2 is an alkylene oxide of C3 or above; component c3 is ethylene oxide; and in the block copolymer, the mass ratio of component c3 to component c2 is (50-100):(50-10); And, the three different polymer segments contained in the block copolymer are arranged in the order of c1-c2-c3; (d) a hydrophilic compound containing 2 to 3 NCO reactive groups, which further comprises an ionic group and / or a potential ionic group; (e) small molecule compounds containing amino groups and / or hydroxyl groups with a functionality of 1 to 3; Based on the total weight of each component, the amount of each component is as follows: The amount of component (a) is 50 to 90 wt %; The amount of component (b) is 5 to 40 wt%; The amount of component (c) is 0.5 to 5 wt%; The amount of component (d) is 0.2 to 20 wt%; The amount of component (e) used is 0.05 to 5 wt%.

2. The polyurethane or polyurethane-urea aqueous dispersion according to claim 1, characterized in that Based on the total weight of each component, the amount of each component is as follows: The amount of component (a) is 75 to 90 wt %; The amount of component (b) is 10 to 30 wt%; The amount of component (c) is 0.8 to 3.0 wt %; The amount of component (d) is 1 to 5 wt%; The amount of component (e) used is 0.5 to 3 wt%.

3. The polyurethane or polyurethane-urea aqueous dispersion according to claim 1, characterized in that The polymer polyol is selected from one or more polymer diols having a number average molecular weight of 600-4000; and / or The isocyanate is diisocyanate.

4. The polyurethane or polyurethane-urea aqueous dispersion according to claim 3, characterized in that The polymer polyol is selected from aliphatic linear or slightly branched polyester polyols or polycarbonate polyols.

5. The polyurethane or polyurethane-urea aqueous dispersion according to claim 3, characterized in that The polymer polyol is selected from polyester diols prepared by reacting one or more of 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol and neopentyl glycol with adipic acid.

6. The polyurethane or polyurethane-urea aqueous dispersion according to claim 3, characterized in that The isocyanate is selected from one or more of hexamethylene diisocyanate, dodecamethylene diisocyanate, isophorone diisocyanate, 1,4-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 4,4'-dicyclohexylpropane diisocyanate, 1,4-toluene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, tetramethylxylene diisocyanate and p-xylylene diisocyanate.

7. The polyurethane or polyurethane-urea aqueous dispersion according to claim 3, characterized in that The isocyanate is selected from one or more of hexamethylene diisocyanate, isophorone diisocyanate and 2,6-toluene diisocyanate.

8. The polyurethane or polyurethane-urea aqueous dispersion according to claim 1, characterized in that In the block copolymer of component (c): Component c1 is selected from one or more of methanol, ethanol, propanol, butanol, pentanol, hexanol, octanol, nonanol, decanol and dodecanol; Component c2 is selected from one or more of propylene oxide, butylene oxide and 1,2-dimethylethylene oxide.

9. The polyurethane or polyurethane-urea aqueous dispersion according to claim 8, characterized in that In the block copolymer of component (c): component c1 is butanol.

10. The polyurethane or polyurethane-urea aqueous dispersion according to claim 8, characterized in that In the block copolymer of component (c): component c2 is propylene oxide.

11. The polyurethane or polyurethane-urea aqueous dispersion according to claim 1, characterized in that In the block copolymer of component (c), the mass ratio of component c3 to component c2 is (75-100):(25-10).

12. The polyurethane or polyurethane-urea aqueous dispersion according to claim 11, characterized in that In the block copolymer of component (c), the mass ratio of component c3 to component c2 is (80-90):(10-20).

13. The polyurethane or polyurethane-urea aqueous dispersion according to claim 1, characterized in that The number average molecular weight of component (c) is 800-3000.

14. The polyurethane or polyurethane-urea aqueous dispersion according to claim 13, characterized in that The number average molecular weight of component (c) is 1200-2500.

15. The polyurethane or polyurethane-urea aqueous dispersion according to claim 1, characterized in that Component (d) is selected from hydrophilic compounds containing ionic groups and 2-3 NCO reactive functional groups and / or hydrophilic compounds containing potential ionic groups and 2-3 NCO reactive functional groups; wherein: The NCO reactive group is an amino group and / or a hydroxyl group; The ionic groups and / or potential ionic groups are selected from one or more of dihydroxycarboxylic acids and salts thereof, trihydroxycarboxylic acids and salts thereof, dihydroxysulfonic acids and salts thereof, trihydroxysulfonic acids and salts thereof, diaminosulfonic acids and salts thereof, triaminosulfonic acids and salts thereof, diaminocarboxylic acids and salts thereof, and triaminocarboxylic acids and salts thereof; and / or Component (e) is an aliphatic small molecule compound having a functionality of 1 to 3 and containing a primary or secondary amino group.

16. The polyurethane or polyurethane-urea aqueous dispersion according to claim 15, characterized in that The ionic groups and / or potential ionic groups in component (d) are selected from one or more of dihydroxymethylacetic acid and its alkali metal salts and / or ammonium salts, dihydroxymethylpropionic acid and its alkali metal salts and / or ammonium salts, dihydroxymethylbutyric acid and its alkali metal salts and / or ammonium salts, N-(2-aminoethyl)-2-aminoethanesulfonic acid and its alkali metal salts and / or ammonium salts, N-(3-aminopropyl)-2-aminoethanesulfonic acid and its alkali metal salts and / or ammonium salts, N-(2-aminoethyl)-2-aminobutanesulfonic acid and its alkali metal salts and / or ammonium salts and N-(2-aminoethyl)-3-aminopropanesulfonic acid and its alkali metal salts and / or ammonium salts.

17. The polyurethane or polyurethane-urea aqueous dispersion according to claim 15, characterized in that Component (e) is selected from one or more of isophoronediamine, 1,6-hexamethylenediamine, N-(2-hydroxyethyl)ethylenediamine, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and diethanolamine.

18. The polyurethane or polyurethane-urea aqueous dispersion according to any one of claims 1 to 17, characterized in that The polyurethane or polyurethane-urea aqueous dispersion has a solid content of 10-74 wt % and a pH value of 6-9.

19. The polyurethane or polyurethane-urea aqueous dispersion according to claim 18, characterized in that The solid content of the polyurethane or polyurethane-urea aqueous dispersion is 40-60wt%; and the pH value is 7-8.

20. The method for preparing a polyurethane or polyurethane-urea aqueous dispersion according to any one of claims 1 to 19, characterized in that: The steps include: Components (a), (b) and (c) are mixed and polymerized to form a prepolymer with terminal isocyanate; components (d) and (e) are reacted with the prepolymer, and then dispersed with water to finally obtain a polyurethane or polyurethane-urea aqueous dispersion.

21. Use of the polyurethane or polyurethane-urea aqueous dispersion according to any one of claims 1 to 19 or the polyurethane or polyurethane-urea aqueous dispersion prepared by the preparation method according to claim 20 in the fields of adhesives and synthetic leather.

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