Aqueous dispersion of polyurethane or polyurethane urea as well as preparation method and application of aqueous dispersion

Abstract

The invention relates to the technical field of adhesives, and provides an aqueous dispersion of polyurethane or polyurethane urea as well as a preparation method and application of the aqueous dispersion, the aqueous dispersion provided by the invention is used as an effective component of an adhesive, can obtain better damp-heat resistance and hydrolysis resistance, and also has good initial adhesion. The aqueous dispersion provided by the invention is prepared by reacting a composition comprising the following components: a) at least one siloxane compound; b) at least one polyol; c) at least one polyisocyanate; d) at least one hydrophilic compound; e) at least one nonionic hydrophilic compound; optionally, component f): at least one compound containing 1-3 amino groups and not containing COOH groups; optionally, the raw materials for preparing the aqueous dispersion also comprise an optional component g): at least one compound containing COOH groups and simultaneously containing 1-3 amino groups or hydroxyl groups; in addition, the acid value of the aqueous dispersion ranges from 0.005 mgKOH / g to 5 mgKOH / g.

Description

Technical Field

[0001] The invention belongs to the technical field of adhesives, and specifically relates to a water dispersion of polyurethane or polyurethane urea and a preparation method and application thereof. Background Art

[0002] In the process of shoe production, adhesives must be used to bond the outsole and midsole, the outsole and the upper, or the upper fabric. Two-component brushing is the mainstream form now. The two-component includes two components, polyurethane glue and curing agent. Before use, the two components are evenly mixed in a certain proportion. Polyurethane glue, as the main component of shoe adhesive, provides appropriate bonding force for various shoe materials. Curing agent can connect two or more polyurethane molecules, play a chemical cross-linking role, and improve the durability of shoe glue.

[0003] US4870129 discloses a polyurethane or polyurethane-urea aqueous dispersion, which introduces hydroxyl groups into the molecular chain and is used in combination with an isocyanate curing agent. The crosslinking density is increased by the reaction between isocyanate and hydroxyl groups, which significantly improves the bonding strength and heat resistance. However, due to the addition of the curing agent, the open time of the finished glue is short. If the glue is adjusted too much, it will cause glue waste and increase production costs. At the same time, the curing agent contains a large number of NCO groups, which are highly toxic and have an impact on the environment and the health of downstream workers.

[0004] CN110016117 discloses a method for preparing and applying a self-crosslinking polyurethane dispersion, which is formed by reacting triphenylmethanol and a polyurethane prepolymer, and can maintain chemical stability for a long time at room temperature. When the temperature rises to 70-80°C, the polyurethane begins to unblock, and the triphenylmethanol falls off from the main chain in a large area, unblocking the polyurethane containing NCO groups at the end, and NCO then reacts chemically with the structure containing active hydrogen in the polyurethane chain to form a stable chemical crosslinking structure, thereby enhancing its adhesive effect. However, since the unblocking temperature of the blocking agent triphenylmethanol is only 70-80°C, and the blocking-unblocking process is a reversible reaction, this puts forward higher requirements for the storage environment of the emulsion and the production and transportation process of the shoe glue. And in the process of use, the triphenylmethanol produced by unblocking has a boiling point of up to 380°C, which will remain in the glue, has the danger of potential toxicity and environmental pollution, and its widespread use is limited.

[0005] Patents such as DE4410557 and DE19954500 propose to introduce carboxylate into the aqueous dispersion of polyurethane or polyurethane urea, and then compound it with carbodiimide, and use the reaction between carboxylic acid and carbodiimide to increase the crosslinking density and improve the strength of the adhesive. Among them, the carboxylate is obtained by adding dimethylol propionic acid to polyurethane or polyurethane urea and then neutralizing it with tertiary amine. However, this type of dispersion contains a large number of carboxyl groups and has poor hydrolysis resistance. After adding another component of carbodiimide, the generation of a large number of crosslinking components usually leads to a decrease in viscosity, and it is easy to debond during bonding.

[0006] CN101381451 describes a self-crosslinkable aqueous polyurethane dispersion obtained by adding a sterically hindered siloxane. Although the addition of a sterically hindered siloxane structure can ensure the stable storage of the self-crosslinking dispersion, it will also cause the crosslinking reaction rate to be too slow during the use of the dispersion and fail to establish the required performance. At the same time, the patent also points out that the dispersion prepared using a non-sterically hindered siloxane crosslinking monomer containing methoxy or ethoxy groups cannot be stored stably and has no self-crosslinking performance.

[0007] CN108250390 describes that a self-crosslinking waterborne polyurethane dispersion can be obtained by adding non-sterically hindered siloxane. However, because the trimethoxy or triethoxy groups are affected by steric hindrance, the silane groups cannot be completely hydrolyzed and crosslinked, or the degree of crosslinking of the dimethoxy or diethoxy groups is insufficient, resulting in a certain gap in resistance compared with a two-component system, which limits the use of high-end shoes with high resistance requirements.

[0008] CN109081897 describes a method for preparing a waterborne polyurethane with excellent moisture and heat resistance, which introduces two silanes to the main chain and side chain of the polyurethane respectively, and the siloxanes are hydrolyzed and cross-linked with each other, thereby establishing moisture and heat resistance. However, the waterborne polyurethane prepared by this method has a large amount of cross-linking, which affects the viscosity, is easy to debond during lamination, increases the rework rate, and greatly reduces the efficiency of shoe production.

[0009] CN112079989 discloses a method for preparing waterborne polyurethane, which introduces a compound containing a COOH group that can react with isocyanate, and then uses it in combination with carbodiimide to improve the initial bonding strength of the adhesive. The acid value content is high, and the use of carboxyl groups leads to a decrease in the hydrolysis resistance of the waterborne polyurethane dispersion and a short shelf life. Summary of the invention

[0010] The present invention provides a polyurethane or polyurethane urea aqueous dispersion and a preparation method and application thereof. The aqueous dispersion provided by the present invention is used as an effective component of an adhesive and can obtain better moisture and heat resistance and hydrolysis resistance without using a curing agent, while also having good initial adhesion.

[0011] To achieve its object, the present invention provides the following technical solutions:

[0012] The present invention provides an aqueous dispersion of polyurethane or polyurethane urea, which is prepared by reacting a composition comprising the following components:

[0013] a) At least one siloxane compound, the general formula of the siloxane compound being

[0014] wherein the group R contains at least one NCO-reactive group, and at least two of the groups R1, R2 and R3 are the same or different alkoxy groups, and the alkoxy groups are selected from methoxy or ethoxy;

[0015] b) At least one polyol having a functionality of 2-4;

[0016] c) At least one polyisocyanate;

[0017] d) At least one hydrophilic compound, and the hydrophilic group of the hydrophilic compound comprises one or more of ionic groups or latent ionic groups, and the hydrophilic compound contains 2-3 NCO-reactive groups;

[0018] e) At least one monofunctional non-ionic hydrophilic compound reactive with NCO;

[0019] Optional component f): At least one compound containing 1-3 amino groups and no COOH group;

[0020] Optionally, the raw materials for preparing the aqueous dispersion further include an optional component g): At least one compound containing a COOH group and simultaneously containing 1-3 amino groups or hydroxyl groups;

[0021] Based on the total mass of the components a)-g), the amounts of each component are as follows: component a) 0.05-1.25 wt%, component b) 75-92 wt%, component c) 7-17 wt%, component d) 0.5-2.5 wt%, component e) 0.02-1.5 wt%, component f) 0-2.5 wt%, component g) 0-3 wt%;

[0022] Moreover, the acid value of the aqueous dispersion is between 0.005 mg KOH / g and 5 mg KOH / g, preferably between 0.01 mg KOH / g and 3 mg KOH / g, and more preferably between 0.02 mg KOH / g and 3 mg KOH / g.

[0023] In some preferred embodiments, during the preparation of the aqueous dispersion, the prepolymer of the terminal isocyanate is prepared in the presence of trace alkali metal ions, and based on the total mass of the prepolymer of the terminal isocyanate being 100%, the content of the alkali metal ions is 0.1 ppm - 30 ppm, preferably 0.1 - 23 ppm, and the alkali metal ions are selected from Na + and / or K + ;

[0024] The prepolymer of the terminal isocyanate is obtained by reacting a raw material containing at least component b), component c) and component e).

[0025] In some embodiments, in component a), the NCO-reactive group in group R is selected from one or more of a hydroxyl group, a primary amino group and a secondary amino group; preferably, component a) has at least one primary amino group or secondary amino group; preferably, group R is a saturated fatty alkyl chain having at least one primary amino group and / or secondary amino group, and optionally has an alkoxy group;

[0026] Preferably, component a) is selected from one or more of bis(3-trimethoxysilylpropyl)amine, bis(3-triethoxysilylpropyl)amine, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane.

[0027] In some embodiments, in component b), the number average molecular weight of the polyol is 500 - 10000, preferably 1000 - 5000, more preferably 1000 - 4000;

[0028] Preferably, the polyol is selected from one or more of a diol, a triol and a tetraol;

[0029] Further preferably, the polyol is selected from one or more of polyadipic acid series polyester polyols, polycaprolactone polyols and polycarbonate polyols;

[0030] More preferably, the polyol is a polyadipic acid series polyester diol having a functionality of 2 and a number average molecular weight of 1000 - 4000.

[0031] In some embodiments, among component c), the polyisocyanate is selected from one or more of tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 1,4-diisocyanato-cyclohexane, isophorone diisocyanate, 4,4'-diisocyanato-dicyclohexyl-methane, 4,4'-diisocyanato-2,2-dicyclohexylpropane, 1,4-diisocyanatobenzene, 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene, 4,4'-diisocyanato-diphenylmethane, 2,2'-diisocyanatodiphenylmethane, 2,4'-diisocyanatodiphenylmethane, tetramethylxylylene diisocyanate, p-xylylene diisocyanate, p-isopropylidene diisocyanate, p-phenylene diisocyanate, and cyclohexane dimethylene diisocyanate; preferably hexamethylene diisocyanate and / or isophorone diisocyanate.

[0032] In some embodiments, among component d), the hydrophilic compound is selected from one or more of N-(2-aminoethyl)-2-aminoethanesulfonic acid, N-(3-aminopropyl)-2-aminoethanesulfonic acid, N-(3-aminopropyl)-3-aminopropanesulfonic acid, N-(2-aminoethyl)-3-aminopropanesulfonic acid, and their alkali metal salts, alkaline earth metal salts, and ammonium salts; preferably N-(2-aminoethyl)-2-aminoethanesulfonate.

[0033] In some embodiments, in component e), the number average molecular weight of the nonionic hydrophilic compound is 200 - 8000, preferably 500 - 3000;

[0034] Preferably, the number of ethylene oxide units of the nonionic hydrophilic compound is 4 - 200, more preferably 12 - 75;

[0035] Preferably, the nonionic hydrophilic compound is a monofunctional polyethoxylated ether with a number average molecular weight of 200 - 8000 and 4 - 200 ethylene oxide units, more preferably poly(ethylene glycol) monomethyl ether with a number average molecular weight of 500 - 3000 and 12 - 75 ethylene oxide units.

[0036] In some embodiments, in component f), the compound containing 1 - 3 amino groups and no COOH groups is one or more of aliphatic amine compounds and alicyclic amine compounds. Preferably, the amino groups contained therein are primary amine groups and / or secondary amine groups. Optionally, the compound containing 1 - 3 amino groups and no COOH groups contains hydroxyl groups;

[0037] Preferably, component f) is selected from one or two of isophorone diamine and N-(2-hydroxyethyl)ethylenediamine.

[0038] In some embodiments, the raw materials for preparing the aqueous dispersion include component g), and component g) is preferably selected from one or more of monohydroxycarboxylic acids, dihydroxycarboxylic acids, dihydroxydicarboxylic acids, trihydroxycarboxylic acids, monoaminocarboxylic acids, diamino-carboxylic acids, and triaminocarboxylic acids;

[0039] Preferably, component g) is selected from one or more of dimethylolpropionic acid, dimethylolbutyric acid, dimethylolacetic acid, dihydroxysuccinic acid, hydroxypivalic acid, glycolic acid, hydroxypropionic acid, lysine, lactic acid, 6-aminohexanoic acid, alanine, N-(2-aminoethyl)-β-alanine, aminoundecanoic acid, 8-aminooctanoic acid, 5-aminopentanoic acid, 4-aminobutyric acid, aminobenzoic acid, 4-aminomethylcyclohexanecarboxylic acid, 2-aminohexanoic acid, 4-aminocyclohexanecarboxylic acid, 12-aminododecanoic acid, and 9-aminononanoic acid, more preferably one or more of dimethylolpropionic acid, lactic acid, and lysine.

[0040] The present invention also provides a method for preparing an aqueous dispersion of the polyurethane or polyurethane urea described above, the method comprising the following steps:

[0041] S1: Reacting component b), component c), and component e) to form a prepolymer having terminal isocyanate groups;

[0042] S2: After dissolution, continuously reacting the prepolymer with component d), component a), and optionally component f), and then dispersing with water;

[0043] In step S1 and / or step S2, a solvent that can be partially or completely removed during dispersion or by distillation after dispersion is optionally used;

[0044] The optional component g) is added at any stage of step S1 and / or step S2;

[0045] Meanwhile, during the preparation of the aqueous dispersion, the acid value of the obtained aqueous dispersion is controlled to be between 0.005 mg KOH / g and 5 mg KOH / g, preferably between 0.01 mg KOH / g and 3 mg KOH / g, more preferably between 0.02 mg KOH / g and 3 mg KOH / g.

[0046] In some embodiments, in step S1, the preparation of the prepolymer having terminal isocyanate groups is carried out in the presence of trace alkali metal ions, and based on the total mass of the prepolymer having terminal isocyanate groups being 100%, the content of the alkali metal ions is 0.1 ppm - 30 ppm, and the alkali metal ions are selected from Na + and / or K + .

[0047] The present invention also provides the use of the aqueous dispersion described above or the aqueous dispersion prepared by the method described above in the preparation of adhesives and sealants.

[0048] The technical solution provided by the present invention has the following beneficial effects:

[0049] For the aqueous dispersion of polyurethane or polyurethane urea provided by the present invention, a non-hindered siloxane functional monomer is introduced into the reaction system, and at the same time, the acid value of the dispersion is controlled to be between 0.005 mg KOH / g and 5 mg KOH / g. As an effective component of the adhesive, it can obtain better heat and humidity resistance and hydrolysis resistance without using a curing agent, and at the same time take into account good initial tack, have an extended shelf life and better storage stability, and its performance can be comparable to that of a two-component system. Detailed Embodiments

[0050] To facilitate the understanding of the present invention, the present invention will be further described below in conjunction with embodiments. It should be understood that the following embodiments are only for better understanding of the present invention and do not mean that the present invention is limited only to the following embodiments.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The term "and / or" as used herein may include any and all combinations of one or more of the related listed items.

[0052] The present invention provides an aqueous dispersion of polyurethane or polyurethane urea, which is prepared by reacting a composition comprising the following components:

[0053] a) At least one siloxane compound, the general formula of the siloxane compound being

[0054] wherein the group R contains at least one NCO-reactive group, and at least two of the groups R1, R2 and R3 are the same or different alkoxy groups, and the alkoxy group is selected from methoxy or ethoxy;

[0055] b) At least one polyol having a functionality of 2-4;

[0056] c) At least one polyisocyanate;

[0057] d) At least one hydrophilic compound, and the hydrophilic group of the hydrophilic compound comprises one or more of ionic groups or latent ionic groups, and the hydrophilic compound contains 2-3 NCO-reactive groups;

[0058] e) At least one monofunctional non-ionic hydrophilic compound that is reactive with NCO;

[0059] Optional component f): at least one compound containing 1 to 3 amino groups and no COOH groups;

[0060] Optionally, the raw materials for preparing the aqueous dispersion further include optional component g): at least one compound containing a COOH group and 1 to 3 amino or hydroxyl groups;

[0061] Based on the total mass of the components a) to g), the amounts of the components are: component a) 0.05-1.25wt%, component b) 75-92wt%, component c) 7-17wt%, component d) 0.5-2.5wt%, component e) 0.02-1.5wt%, component f) 0-2.5wt%, component g) 0-3wt%;

[0062] Furthermore, the acid value of the aqueous dispersion is between 0.005 mgKOH / g and 5 mgKOH / g.

[0063] The present invention provides a self-crosslinkable polyurethane or polyurethane urea aqueous dispersion, wherein a non-sterically hindered siloxane functional monomer is introduced into the reaction system, and the acid value of the dispersion is controlled to be between 0.005 mgKOH / g and 5 mgKOH / g. The aqueous dispersion satisfying the specific acid value requirement obtained by the reaction system of the present invention is used as an effective component of an adhesive, and can obtain better moisture and heat resistance and hydrolysis resistance without using a curing agent, while taking into account good initial adhesion, having a prolonged shelf life and better storage stability, and its performance is comparable to that of a two-component system.

[0064] In the conventional practice in the art, in order to avoid hydrolysis of the aqueous dispersion of polyurethane or polyurethane-urea, and to avoid further reduction in resistance, it is usually desired to control the acid value of the aqueous dispersion as low as possible. However, after long-term research, the present inventors unexpectedly found that by controlling the acid value of the polyurethane or polyurethane-urea dispersion within a certain range, the hydrolysis resistance of the aqueous dispersion of polyurethane or polyurethane-urea does not decrease through the synergistic effect with the above-mentioned component a) siloxane compound, but instead has better performance than the aqueous dispersion with too low acid value or no acid value, which is surprising.

[0065] The side chains of the polyurethanes or polyurethane-ureas of the present invention contain non-hindered siloxane groups, and at the same time, the acid value of the dispersion is controlled within a certain range (0.005 mgKOH / g - 5 mgKOH / g). During the activation drying and curing processes in the application process, as the water volatilizes, the probability of collision of the silane coupling agent increases. The weak acidic condition makes the silane coupling agent more likely to undergo hydrolysis and condensation to generate crosslinking. With a specific acid value, it can provide better substrate adhesion, and without losing tackiness, it has more excellent moisture and heat resistance and better storage stability. However, if the acid value of the dispersion is too low, it cannot form a synergistic effect with the siloxane compound (component a)), and the moisture and heat resistance are insufficient; while if the acid value of the dispersion is too high, the excessive COOH in the system will result in poor hydrolysis resistance of the dispersion. Preferably, the acid value of the aqueous dispersion is controlled within 0.01 mgKOH / g - 3 mgKOH / g, and more preferably controlled between 0.02 mgKOH / g - 3 mgKOH / g, which is beneficial for better mutual synergy with component a) and is beneficial for taking into account better initial tack and moisture and heat resistance.

[0066] In some embodiments, the acid value of the aqueous dispersion is, for example, 0.005 mgKOH / g, 0.008 mgKOH / g, 0.01 mgKOH / g, 0.02 mgKOH / g, 0.05 mgKOH / g, 0.10 mgKOH / g, 0.50 mgKOH / g, 1.00 mgKOH / g, 1.25 mgKOH / g, 1.50 mgKOH / g, 2.00 mgKOH / g, 2.50 mgKOH / g, 3.00 mgKOH / g, etc.

[0067] In some embodiments, based on the total mass of components a) - g), the dosage of component a) is, for example, 0.05 wt%, 0.07 wt%, 0.10 wt%, 0.50 wt%, 0.70 wt%, 1.00 wt%, 1.25 wt%, etc. In some embodiments, the dosage of component b) is, for example, 75 wt%, 78 wt%, 80 wt%, 82 wt%, 85 wt%, 87 wt%, 89 wt%, 92 wt%, etc. In some embodiments, the dosage of component c) is, for example, 7 wt%, 10 wt%, 12 wt%, 15 wt%, 17 wt%, etc. In some embodiments, the dosage of component d) is, for example, 0.5 wt%, 0.7 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, etc. In some embodiments, the dosage of component e) is, for example, 0.02 wt%, 0.10 wt%, 0.50 wt%, 1.0 wt%, 1.5 wt%, etc. In some embodiments, the dosage of component f) is, for example, 0 wt%, 0.01 wt%, 0.05 wt%, 0.07 wt%, 0.10 wt%, 0.50 wt%, 1.00 wt%, 1.50 wt%, 2.00 wt%, 2.50 wt%, etc. In some embodiments, the dosage of component g) is, for example, 0 wt%, 0.005 wt%, 0.01 wt%, 0.02 wt%, 0.05 wt%, 0.07 wt%, 0.10 wt%, 0.50 wt%, 1.00 wt%, 1.50 wt%, 2.00 wt%, 2.50 wt%, 3.00 wt%, etc.

[0068] In a preferred embodiment, during the preparation of the aqueous dispersion, the preparation of the prepolymer of terminal isocyanate is carried out in the presence of trace alkali metal ions, and based on 100% of the total mass of the prepolymer of terminal isocyanate, the content of the alkali metal ions is 0.1 ppm - 30 ppm, such as 0.1 ppm, 1 ppm, 5 ppm, 10 ppm, 15 ppm, 20 ppm, 23 ppm, 25 ppm, 30 ppm, etc., preferably 0.1 - 23 ppm, and the alkali metal ions are selected from Na + and / or K +; The prepolymer of the terminal isocyanate is obtained by reacting a raw material containing at least component b), component c) and component e). Among them, the introduction method of the alkali metal ions is not particularly limited, as long as the reaction process for preparing the prepolymer of the terminal isocyanate can be carried out in the presence of 0.1 ppm - 30 ppm of alkali metal ions. In some examples, the alkali metal ions can come from, for example, but are not limited to, one or more of sodium hydroxide, potassium hydroxide, sodium alkoxide and potassium alkoxide, or the alkali metal ions can also be introduced in other ways, such as introducing the above amount of alkali metal ions together with the raw materials required for the reaction; in some embodiments, the above alkali metal ions are introduced before or during the reaction.

[0069] In some embodiments, in component a), the NCO-reactive group in group R is selected from one or more of a hydroxyl group, a primary amino group and a secondary amino group; preferably, component a) has at least one primary amino group or secondary amino group; more preferably, in component a), group R is a saturated fatty alkyl chain having at least one primary amino group and / or secondary amino group, and optionally has an alkoxy group; preferably, at least two of groups R1, R2, and R3 are alkoxy groups directly substituted by the same or different saturated fatty alkyl chains. Preferably, component a) is selected from one or more of bis(3-trimethoxysilylpropyl)amine, bis(3-triethoxysilylpropyl)amine, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane; more preferably bis(3-methoxysilylpropyl)amine, 3-aminopropyltriethoxysilane and / or N-β-(aminoethyl)-γ-aminopropyltriethoxysilane.

[0070] In some embodiments, in component b), the number-average molecular weight of the polyol is 500 - 10000, preferably 1000 - 5000, more preferably 1000 - 4000; preferably, the polyol is selected from one or more of a diol, a triol and a tetrol, such as one or more of a diol, a triol and a tetrol having a number-average molecular weight of 1000 - 5000; more preferably, the polyol is selected from one or more of a polyadipic acid series polyester polyol, a polycaprolactone polyol and a polycarbonate polyol, such as one or more of a polyadipic acid series polyester polyol, a polycaprolactone polyol and a polycarbonate polyol having a number-average molecular weight of 1000 - 4000; more preferably, the polyol is selected from a polyadipic acid series polyester diol having a functionality of 2 and a number-average molecular weight of 1000 - 4000.

[0071] In some embodiments, in component c), the polyisocyanate is selected from one or more of tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 1,4-diisocyanato-cyclohexane, isophorone diisocyanate, 4,4'-diisocyanato-dicyclohexyl-methane, 4,4'-diisocyanato-2,2-dicyclohexylpropane, 1,4-diisocyanatobenzene, 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene, 4,4'-diisocyanato-diphenylmethane, 2,2'-diisocyanatodiphenylmethane, 2,4'-diisocyanatodiphenylmethane, tetramethylxylylene diisocyanate, p-xylylene diisocyanate, p-isopropylidene diisocyanate, p-phenylene diisocyanate, and cyclohexane dimethylene diisocyanate; preferably hexamethylene diisocyanate and / or isophorone diisocyanate.

[0072] In some embodiments, in component d), the hydrophilic compound is selected from, but not limited to, one or more of N-(2-aminoethyl)-2-aminoethanesulfonic acid, N-(3-aminopropyl)-2-aminoethanesulfonic acid, N-(3-aminopropyl)-3-aminopropanesulfonic acid, N-(2-aminoethyl)-3-aminopropanesulfonic acid, and their alkali metal salts, alkaline earth metal salts, and ammonium salts; preferably N-(2-aminoethyl)-2-aminoethanesulfonate.

[0073] In some embodiments, in component e), the number average molecular weight of the nonionic hydrophilic compound is 200 - 8000, preferably 500 - 3000; preferably, the number of ethylene oxide units in the nonionic hydrophilic compound is 4 - 200, more preferably 12 - 75; preferably, the nonionic hydrophilic compound is a monofunctional polyethoxy ether having a number average molecular weight of 200 - 8000 and 4 - 200 ethylene oxide units, more preferably polyethylene glycol monomethyl ether having a number average molecular weight of 500 - 3000 and 12 - 75 ethylene oxide units.

[0074] In some embodiments, in component f), the compound containing 1 - 3 amino groups and no COOH group is one or more of aliphatic amine compounds and alicyclic amine compounds. Preferably, the amino groups contained therein are primary amine groups and / or secondary amine groups. Optionally, the compound containing 1 - 3 amino groups and no COOH group contains hydroxyl groups; preferably, component f) is selected from one or two of isophorone diamine and N-(2-hydroxyethyl)ethylenediamine.

[0075] The acid value of the aqueous dispersion can be achieved by adding free COOH-containing substances and / or introducing isocyanate-reactive compounds containing COOH groups during the preparation process of the aqueous dispersion, or it can also be achieved by other means to make the acid value of the final obtained aqueous dispersion controlled within the range of 0.005 mg KOH / g - 5 mg KOH / g required by the present invention, preferably 0.01 mg KOH / g - 3 mg KOH / g, more preferably between 0.02 mg KOH / g - 3 mg KOH / g. By controlling the above acid value, it can synergistically act with component a) in the formulation system of the present invention, so that the aqueous dispersion can have better initial tack, moisture and heat resistance, and hydrolysis resistance without using a curing agent. The free COOH-containing substances and the isocyanate-reactive compounds containing COOH groups (i.e., component g)) are preferably selected from one or more of monohydroxycarboxylic acids, dihydroxycarboxylic acids, dihydroxydicarboxylic acids, trihydroxycarboxylic acids, monoaminocarboxylic acids, diamino-carboxylic acids, triaminocarboxylic acids, etc. Preferably, the component g) is selected from one or more of dimethylolpropionic acid, dimethylolbutyric acid, dimethylolacetic acid, dihydroxysuccinic acid, hydroxypivalic acid, glycolic acid, hydroxypropionic acid, lysine, lactic acid, 6-aminohexanoic acid, alanine, N-(2-aminoethyl)-β-alanine, 11-aminoundecanoic acid, 8-aminooctanoic acid, 5-aminopentanoic acid, 4-aminobutyric acid, aminobenzoic acid, 4-aminomethylcyclohexanecarboxylic acid, 2-aminohexanoic acid, 4-aminocyclohexanecarboxylic acid, 12-aminododecanoic acid, and 9-aminononanoic acid, more preferably one or more of dimethylolpropionic acid, lactic acid, and lysine. The above scheme is a preferred scheme, and those skilled in the art can also choose other methods to achieve it.

[0076] In some embodiments, the solid content of the aqueous dispersion of the polyurethane or polyurethane-urea provided by the present invention is 30 - 70 wt%, preferably 45 - 55 wt%, and the remaining part is water. In some preferred embodiments, the average particle size of the aqueous dispersion of the polyurethane or polyurethane-urea provided by the present invention is 100 - 300 nm, preferably 160 - 230 nm; preferably, the pH value of the aqueous dispersion of the polyurethane or polyurethane-urea is 4 - 11, preferably 7 - 9.

[0077] The present invention also provides a method for preparing the aqueous dispersion of the polyurethane or polyurethane-urea described above, and the method includes:

[0078] S1: Reacting the component b), component c) and component e) to form a prepolymer with terminal isocyanate;

[0079] S2: After dissolution, continuously reacting the prepolymer with the component d), component a) and optionally the component f), and then dispersing with water;

[0080] In step S1 and / or step S2, a solvent that can be partially or completely removed during dispersion or by distillation after dispersion is optionally used;

[0081] The optional component g) is added at any stage of the step S1 and / or step S2;

[0082] Meanwhile, during the preparation of the aqueous dispersion, the acid value of the obtained aqueous dispersion is controlled to be between 0.005 mg KOH / g and 5 mg KOH / g, preferably between 0.01 mg KOH / g and 3 mg KOH / g, and more preferably between 0.02 mg KOH / g and 3 mg KOH / g.

[0083] In the preparation process of the present invention, a specific component a) is introduced into the reaction system, and at the same time, the acid value of the dispersion is controlled to be between 0.005 mg KOH / g and 5 mg KOH / g. Taking the aqueous dispersion prepared by this process as an effective component of the adhesive, good heat and humidity resistance and hydrolysis resistance can be obtained without using a curing agent, while taking into account good initial tack.

[0084] The above steps S1 and S2 can each include one or more stages of reaction and can each include one or more sub-steps. For example, in step S1, components b), c) and e) are reacted in one or more steps to form a prepolymer of terminal isocyanate. For example, in step S2, the prepolymer continues to react with components d), a) and the optional component f) in one or two stages of reaction.

[0085] For the preparation method of the aqueous dispersion of polyurethane or polyurethane urea where no special description is made, it can be carried out with reference to the conventional operations and / or processes in the art.

[0086] In some preferred embodiments, by way of example, the method can be specifically carried out according to the following steps:

[0087] S1: First, mix components b), c), e) and an optional solvent, and react at 75 - 85 °C until the theoretical NCO content is reached (for example, reaching 0.8 - 2.1% of the theoretical NCO content) to obtain a prepolymer of terminal isocyanate; preferably, during this reaction, trace alkali metal ions (Na + and / or K +) in the presence of, for example, based on the total mass of the prepolymer of the terminal isocyanate being 100%, the content of the alkali metal ions is 0.1 ppm - 30 ppm. S2: Cool the prepolymer of the terminal isocyanate and dissolve it with a solvent, add component d), optional component f), and component a) at 40 - 50 °C for reaction, and the reaction time is, for example, 15 - 25 min. Add water for dispersion, and during or after the dispersion, remove all or part of the solvent used by distillation. In steps S1 and S2, each component can be added in one stage or in multiple stages. Each component can be pre-dispersed in a solvent or water and then added to the reaction system, or directly added to the reaction system. When using component g), component g) can be added at any stage of step S1 and / or step S2. In some embodiments, the amount of the solvent is, for example, 1 - 2.5 times the total mass of the solid content, and the amount of water is, for example, 0.7 - 1.5 times the total mass of the solid content.

[0088] During the preparation of the aqueous dispersion, the solvent that can be partially or completely removed by distillation during or after the dispersion is, for example, selected from one or more of acetone, methyl isobutyl ketone, methyl ethyl ketone, tetrahydrofuran, dioxane, acetonitrile, dipropylene glycol dimethyl ether, and 1 - methyl - 2 - pyrrolidone, more preferably acetone and / or methyl ethyl ketone, and further preferably acetone.

[0089] The polyurethane or polyurethane - urea provided by the present invention has a non - sterically hindered siloxane chain segment in the side chain and a certain acid value content. The aqueous dispersion provided by the present invention can be stored stably and has excellent hydrolysis resistance. During the activation drying and curing process, as the water volatilizes, the probability of collision of the silane coupling agent increases. The weak acidic condition makes it easier for the silane coupling agent to undergo hydrolysis and condensation to produce cross - linking. Through the combined action of the silane coupling agent and a specific acid value, it can simultaneously provide good substrate adhesion and, at the same time, take into account more excellent heat - humidity resistance and improve storage stability.

[0090] In a preferred embodiment, in step S1, the preparation of the prepolymer of the terminal isocyanate is carried out in the presence of trace alkali metal ions, and based on the total mass of the prepolymer of the terminal isocyanate being 100%, the content of the alkali metal ions is 0.1 ppm - 30 ppm, and the alkali metal ions are selected from Na + and / or K + . By preparing the prepolymer of the terminal isocyanate in the presence of preferably trace alkali metal ions, it is beneficial to improve the application performance of the finally obtained aqueous dispersion and is beneficial to further improving the heat - humidity resistance.

[0091] The present invention also provides the use of the aqueous dispersion described above or the aqueous dispersion prepared by the method described above in the preparation of adhesives and sealants. The aqueous dispersion provided by the present invention and the adhesives and sealants obtained based on this aqueous dispersion can be applied to the adhesion of materials such as rubber, plastic, leather, textiles, wood, ABS (acrylonitrile-butadiene-styrene), etc. This aqueous dispersion can be used alone or can also be mixed with auxiliary substances and / or additives known in the field of adhesive technology, such as emulsifiers, antioxidants, thickeners, leveling agents, defoamers, etc.

[0092] Compared with the prior art, the polyurethane or polyurethane-urea aqueous dispersion provided by the present invention has at least the following beneficial effects:

[0093] 1. The aqueous dispersion provided by the present invention can be used as a one-component adhesive, and no additional curing agents such as isocyanates and carbodiimides need to be used. The operation is simple and there is no requirement for an open time, which greatly improves the construction efficiency;

[0094] 2. In the aqueous dispersion of the present invention, the addition amount of siloxane is small, the acid value is reasonably controlled, and the aqueous dispersion itself has good stability. The compounding system based on it has more excellent stability and a long storage time. It is suitable for the preparation of high-quality sealants, especially adhesives.

[0095] The technical solution of the present invention will be further described by way of example below.

[0096] For the parts not specifying the specific experimental steps or conditions in the examples, the operations or conditions of the corresponding conventional experimental steps in this technical field can be followed.

[0097] The main raw materials used in the following examples are described as follows. If not otherwise specified, they are all common raw materials that can be obtained through the market:

[0098] Sodium methoxide: Leling Chuangli Technology Co., Ltd.;

[0099] Component a):

[0100] Silane coupling agent I:

[0101] N-(β-aminoethyl)-γ-aminopropyltriethoxysilane, Mn = 264 g / mol (KH791, Nanjing Silicon Innovation Materials Co., Ltd.);

[0102] Silane coupling agent II:

[0103] Bis(3-trimethoxysilylpropyl)amine, Mn = 342 g / mol (SCA-A67W, Nanjing Nengde New Materials Technology Co., Ltd.);

[0104] Silane coupling agent III:

[0105] 3-aminopropyltriethoxysilane, Mn = 221 g / mol (KH550, Nanjing Quanxi Chemical Co., Ltd.);

[0106] Component b):

[0107] Polyester polyol I: Poly(1,4-butylene adipate) diol, M n = 2000 g / mol ( WHP-204, Wanhua Chemical);

[0108] Polyester polyol II: Poly(1,4-butylene adipate) diol, M n = 3000 g / mol ( WHP-304, Wanhua Chemical);

[0109] Polycaprolactone polyol III: Polycaprolactone diol, Mn = 2000 g / mol (PCL-220N, Daicel);

[0110] Polycarbonate polyol IV: Polycarbonate diol, Mn = 2000 g / mol (T5652, Asahi Kasei);

[0111] Component c):

[0112] Polyisocyanate I: Hexamethylene diisocyanate ( HDI, Wanhua Chemical);

[0113] Polyisocyanate II: Isophorone diisocyanate ( IPDI, Wanhua Chemical);

[0114] Component d):

[0115] N-(2-aminoethyl)-2-aminoethanesulfonate ( A95, EVONIK, USA);

[0116] Component e):

[0117] Monomethyl polyethylene glycol, Mn = 1200 g / mol, (MPEG1200, LG Chem);

[0118] Component f):

[0119] Isophorone diamine (IPDA, Wanhua Chemical);

[0120] N-(2-hydroxyethyl)ethylenediamine (AEEA, Yangzi Petrochemical BASF);

[0121] Component g):

[0122] Dimethylolpropionic acid (DMPA, Perstorp);

[0123] Lysine: (LA, Yancheng Greenchem Co., Ltd.);

[0124] Lactic acid: Shanghai Aladdin Biochemical Technology Co., Ltd.

[0125] Example 1

[0126] Add 350 g of polyester polyol I (component b), 40 g of isocyanate I (component c), 2 g of isocyanate II (component c), 1.5 g of DMPA (component g), 2.44 g of MPEG1200 (component e), 0.02 g of sodium methoxide (the amount of sodium ion is 22 ppm of the resulting isocyanate-terminated prepolymer) and 59 g of acetone into a four-necked flask equipped with a reflux condenser, a thermometer and mechanical stirring. React at 80 °C, take samples every 1 h to measure NCO%, and stop the reaction after 3 h until the NCO% reaches the theoretical content of 1.1% to obtain an isocyanate-terminated prepolymer; cool down to about 50 °C, add 614 g of acetone and stir, mix and dissolve for 5 min, then add 1 g of AEEA (component f), 8.4 g A mixture of A95 (component d) and 37 g of deionized water, react at 45 °C for 10 min, then add a mixed solution of 1.5 g of silane coupling agent I (component a) and 6 g of acetone, continue to react for 10 min, pour it into a dispersion cup, add 455 g of water under the condition of high-speed shearing at 1500 rpm, and then remove the acetone by vacuum distillation to obtain a water dispersion of polyurethane-urea. The dispersion has a solid content of 49 wt% and an average particle size of 188 nm measured by laser coherence method in the dispersion phase, the pH value is 7.3, and the acid value is 0.47 mg KOH / g.

[0127] Example 2

[0128] Add 350 g of polyester polyol I (component b), 35 g of polyester polyol II (component b), 40 g of isocyanate I (component c), 4 g of isocyanate II (component c), 4.5 g of MPEG1200 (component e), 0.01 g of sodium methoxide (the amount of sodium ion is 10 ppm of the resulting isocyanate-terminated prepolymer) and 65 g of acetone into a four-necked flask equipped with a reflux condenser, a thermometer and mechanical stirring. React at 80 °C, take samples every 1 h to measure NCO%, and stop the reaction after 3 h until the NCO% reaches the theoretical content of 1.14% to obtain an isocyanate-terminated prepolymer; cool down to about 50 °C, add 672 g of acetone and stir, mix and dissolve for 5 min, then add 2 g of AEEA (component f), 0.6 g of lysine (component g), 7.2 g A mixture of 95 (component d)) and 39 g of deionized water was reacted at 45 °C for 10 min, and then a mixed solution of 0.9 g of silane coupling agent II (component a)) and 4 g of acetone was added, and the reaction was continued for 10 min. The mixture was poured into a dispersion cup, and 499 g of water was added under high-speed shearing conditions of 1500 rpm. Then, acetone was removed by vacuum distillation to obtain an aqueous dispersion of polyurethane-urea. The dispersion had a solid content of 49 wt% and an average particle size of 182 nm measured by laser coherence method in the dispersion phase, a pH value of 7.1, and an acid value of 0.22 mg KOH / g.

[0129] Example 3 (compared with Example 2)

[0130] 350 g of polyester polyol I (component b)), 35 g of polyester polyol II (component b)), 40 g of isocyanate I (component c)), 4 g of isocyanate II (component c)), 4.5 g of MPEG1200 (component e)) and 65 g of acetone were added to a four-necked flask equipped with a reflux condenser, a thermometer and mechanical stirring. The reaction was carried out at 80 °C, and samples were taken every 1 h to measure NCO%. After 3 h, when the NCO% reached the theoretical content of 1.14%, the reaction was stopped to obtain a prepolymer with terminal isocyanate groups. The temperature was lowered to about 50 °C, and 672 g of acetone was added and stirred for 5 min to dissolve. Then, 2 g of AEEA (component f)), 0.6 g of lysine (component g)), 7.2 g A mixture of 95 (component d)) and 39 g of deionized water was reacted at 45 °C for 10 min, and then a mixed solution of 0.9 g of silane coupling agent II (component a)) and 4 g of acetone was added, and the reaction was continued for 10 min. The mixture was poured into a dispersion cup, and 499 g of water was added under high-speed shearing conditions of 1500 rpm. Then, acetone was removed by vacuum distillation to obtain an aqueous dispersion of polyurethane-urea. The dispersion had a solid content of 49 wt% and an average particle size of 178 nm measured by laser coherence method in the dispersion phase, a pH value of 7.0, and an acid value of 0.2 mg KOH / g.

[0131] Example 4

[0132] 205 g of polyester polyol I (component b)), 205 g of polyester polyol II (component b)), 30 g of isocyanate I (component c)), 10 g of isocyanate II (component c)), 0.2 g of MPEG1200 (component e)), 90 g of acetone were added to a four-necked flask equipped with a reflux condenser, a thermometer and mechanical stirring. The reaction was carried out at 80 °C, and samples were taken every 1 h to measure NCO%. After 3 h, when the NCO% reached the theoretical content of 0.82%, the reaction was stopped to obtain a prepolymer with terminal isocyanate groups. The temperature was lowered to about 50 °C, and 765 g of acetone was added and stirred for 5 min to dissolve. Then, 2 g of lysine (component g)) and 7.2 g A mixture of 95 (Component d)) and 37 g of deionized water was reacted at 45 °C for 10 min. Then, a mixed solution of 0.3 g of silane coupling agent III (Component a)) and 3 g of acetone was added, and the reaction was continued for 10 min. The mixture was poured into a dispersion cup, and 521 g of water was added under high-speed shearing conditions at 1500 rpm. Then, acetone was removed by vacuum distillation to obtain an aqueous dispersion of polyurethane-urea. The dispersion had a solid content of 49 wt% and an average particle size of 196 nm measured by laser coherence method in the dispersion phase. The pH value was 7.3, and the acid value was 1.4 mg KOH / g.

[0133] Example 5

[0134] Into a four-necked flask equipped with a reflux condenser, a thermometer, and mechanical stirring, 250 g of polyester polyol I (Component b)), 100 g of polycaprolactone polyol III (Component b)), 50 g of isocyanate I (Component c)), 6 g of MPEG1200 (Component e)), 6 g of DMPA (Component g)), and 41 g of acetone were added. The reaction was carried out at 80 °C, and the NCO% was measured by sampling every 1 h. After 3 h, when the NCO% reached the theoretical content of 1.4%, the reaction was stopped to obtain a prepolymer with terminal isocyanate groups. The temperature was lowered to about 50 °C, and 618 g of acetone was added and stirred for 5 min to dissolve. Then, 4 g of IPDA (Component f)) and 4.5 g A mixture of 95 (Component d)) and 34 g of deionized water was reacted at 45 °C for 10 min. Then, a mixed solution of 3 g of silane coupling agent I (Component a)) and 30 g of acetone was added, and the reaction was continued for 10 min. The mixture was poured into a dispersion cup, and 481 g of water was added under high-speed shearing conditions at 1500 rpm. Then, acetone was removed by vacuum distillation to obtain an aqueous dispersion of polyurethane-urea. The dispersion had a solid content of 49 wt% and an average particle size of 177 nm measured by laser coherence method in the dispersion phase. The pH value was 7.0, and the acid value was 2.7 mg KOH / g.

[0135] Example 6

[0136] Into a four-necked flask equipped with a reflux condenser, a thermometer, and mechanical stirring, 390 g of polyester polyol II (Component b)), 34 g of isocyanate I (Component c)), 3 g of isocyanate II (Component c)), 1 g of MPEG1200 (Component e)), 0.5 g of DMPA (Component g)), and 43 g of acetone were added. The reaction was carried out at 80 °C, and the NCO% was measured by sampling every 1 h. After 3 h, when the NCO% reached the theoretical content of 1.46%, the reaction was stopped to obtain a prepolymer with terminal isocyanate groups. The temperature was lowered to about 50 °C, and 728 g of acetone was added and stirred for 5 min to dissolve. Then, 5 g of IPDA (Component f)) and 10 g A mixture of 95 (Component d)) and 60 g of deionized water was reacted at 45 °C for 10 min, then a mixed solution of 2 g of silane coupling agent I (Component a)) and 20 g of acetone was added, and the reaction was continued for 10 min. It was poured into a dispersion cup, and 478 g of water was added under high-speed shearing conditions of 1500 rpm. Then, acetone was removed by vacuum distillation to obtain an aqueous dispersion of polyurethane-urea. The dispersion had a solid content of 49 wt% and an average particle size of 192 nm measured by laser coherence method in the dispersion phase, a pH value of 7.3, and an acid value of 0.008 mg KOH / g.

[0137] Example 7

[0138] 370 g of polyester polyol I (Component b)), 50 g of isocyanate I (Component c)), 20 g of isocyanate II (Component c)), 7 g of MPEG1200 (Component e)), 10 g of DMPA (Component g)) and 46 g of acetone were added to a four-necked flask equipped with a reflux condenser, a thermometer and mechanical stirring. The reaction was carried out at 80 °C, and the NCO% was measured by sampling every 1 h. After 3 h, when the NCO% reached the theoretical content of 2.09%, the reaction was stopped to obtain a prepolymer with terminal isocyanate groups; the temperature was lowered to about 50 °C, 777 g of acetone was added and stirred, and the mixture was dissolved for 5 min. Then, 10 g of IPDA (Component f)) and 4.5 g A mixture of 95 (Component d)) and 58 g of deionized water was reacted at 45 °C for 10 min, then a mixed solution of 5 g of silane coupling agent I (Component a)) and 20 g of acetone was added, and the reaction was continued for 10 min. It was poured into a dispersion cup, and 522 g of water was added under high-speed shearing conditions of 1500 rpm. Then, acetone was removed by vacuum distillation to obtain an aqueous dispersion of polyurethane-urea. The dispersion had a solid content of 49 wt% and an average particle size of 185 nm measured by laser coherence method in the dispersion phase, a pH value of 6.9, and an acid value of 4.5 mg KOH / g.

[0139] Example 8

[0140] 200 g of polyester polyol I (Component b)), 150 g of polycarbonate polyol IV (Component b)), 40 g of isocyanate I (Component c)), 2 g of isocyanate II (Component c)), 2.44 g of MPEG1200 (Component e)) and 59 g of acetone were added to a four-necked flask equipped with a reflux condenser, a thermometer and mechanical stirring. The reaction was carried out at 80 °C, and the NCO% was measured by sampling every 1 h. After 3 h, when the NCO% reached the theoretical content of 1.32%, the reaction was stopped to obtain a prepolymer with terminal isocyanate groups; the temperature was lowered to about 50 °C, 611 g of acetone was added and stirred, and the mixture was dissolved for 5 min. Then, 1 g of AEEA (Component f)), 8.4 g A mixture of 37 g of deionized water and A95 (component d)) was reacted at 45 °C for 10 min. Then, a mixed solution of 1.5 g of silane coupling agent I (component a)) and 6 g of acetone was added, and the reaction was continued for 10 min. The mixture was poured into a dispersion cup, and 455 g of water was added under high-speed shearing conditions at 1500 rpm. Then, acetone was removed by vacuum distillation. A mixed solution of 1.5 g of lactic acid (component g)) and 10 g of water was added to obtain an aqueous dispersion of polyurethane-urea. The dispersion had a solid content of 49 wt% and an average particle size of 188 nm measured by laser coherence method in the dispersion phase. The pH value was 7.3, and the acid value was 0.66 mg KOH / g.

[0141] Comparative Example 1 (compared with Example 3)

[0142] 350 g of polyester polyol I (component b)), 35 g of polyester polyol II (component b)), 40 g of isocyanate I (component c)), 4 g of isocyanate II (component c)), 4.5 g of MPEG1200 (component e)), and 65 g of acetone were added to a four-necked flask equipped with a reflux condenser, a thermometer, and mechanical stirring. The reaction was carried out at 80 °C, and samples were taken every 1 h to measure the NCO%. After 3 h, when the NCO% reached the theoretical content of 1.14%, the reaction was stopped to obtain a prepolymer with terminal isocyanate groups. The temperature was lowered to about 50 °C, and 672 g of acetone was added and stirred for 5 min to dissolve it. Then, 2 g of AEEA (component f)), 0.2 g of lysine (component g)), and 7.2 g A mixture of 39 g of deionized water and A95 (component d)) was reacted at 45 °C for 10 min. Then, a mixed solution of 0.9 g of silane coupling agent II (component a)) and 4 g of acetone was added, and the reaction was continued for 10 min. The mixture was poured into a dispersion cup, and 499 g of water was added under high-speed shearing conditions at 1500 rpm. Then, acetone was removed by vacuum distillation to obtain an aqueous dispersion of polyurethane-urea. The dispersion had a solid content of 49 wt% and an average particle size of 185 nm measured by laser coherence method in the dispersion phase. The pH value was 7.2, and the acid value was 0.004 mg KOH / g.

[0143] Comparative Example 2 (compared with Example 7)

[0144] Add 370 g of polyester polyol I (component b), 50 g of isocyanate I (component c), 20 g of isocyanate II (component c), 7 g of MPEG1200 (component e), 13 g of DMPA (component g), and 46 g of acetone into a four-necked flask equipped with a reflux condenser, a thermometer, and mechanical stirring. React at 80 °C and take samples every 1 h to measure the NCO%. After 3 h until the NCO% reaches the theoretical content of 1.71%, stop the reaction to obtain an isocyanate-terminated prepolymer; cool down to about 50 °C, add 777 g of acetone and stir, mix and dissolve for 5 min, then add a mixture of 6 g of IPDA (component f) and 4.5 g A95 (component d)) and 58 g of deionized water, react at 45 °C for 10 min, then add a mixed solution of 5 g of silane coupling agent I (component a) and 20 g of acetone, continue to react for 10 min, pour it into a dispersion cup, add 522 g of water under the condition of high-speed shearing at 1500 rpm, and then remove the acetone by vacuum distillation to obtain a water dispersion of polyurethane-urea. This dispersion has a solid content of 49 wt% and an average particle size of 177 nm measured by laser coherence method in the dispersion phase, the pH value is 7.0, and the acid value is 5.5 mg KOH / g.

[0145] Comparative Example 3 (compared with Example 3, no silane coupling agent was added)

[0146] Add 350 g of polyester polyol I, 35 g of polyester polyol II, 40 g of isocyanate I, 4 g of isocyanate II, 4.5 g of MPEG1200, and 65 g of acetone into a four-necked flask equipped with a reflux condenser, a thermometer, and mechanical stirring. React at 80 °C and take samples every 1 h to measure the NCO%. After 3 h until the NCO% reaches the theoretical content of 1.14%, stop the reaction to obtain an isocyanate-terminated prepolymer; cool down to about 50 °C, add 672 g of acetone and stir, mix and dissolve for 5 min, then add 2 g of AEEA, 0.6 g of lysine, and 7.2 g A95 and 39 g of deionized water, react at 45 °C for 20 min, pour it into a dispersion cup, add 498 g of water under the condition of high-speed shearing at 1500 rpm, and then remove the acetone by vacuum distillation to obtain a water dispersion of polyurethane-urea. This dispersion has a solid content of 49 wt% and an average particle size of 191 nm measured by laser coherence method in the dispersion phase, the pH value is 7.2, and the acid value is 0.22 mg KOH / g.

[0147] Comparative Example 4 (compared with Example 3, the amount of silane coupling agent used is less)

[0148] Add 350 g of polyester polyol I, 35 g of polyester polyol II, 40 g of isocyanate I, 4 g of isocyanate II, 4.5 g of MPEG1200, 65 g of acetone into a four-necked flask equipped with a reflux condenser, a thermometer and mechanical stirring. React at 80 °C and take samples every 1 h to measure NCO%. After 3 h until the NCO% reaches the theoretical content of 1.14%, stop the reaction to obtain a prepolymer with terminal isocyanate groups; cool down to about 50 °C, add 672 g of acetone and stir, mix and dissolve for 5 min, then add 2 g of AEEA, 0.6 g of lysine and 7.2 g A mixture of A95 and 39 g of deionized water, react at 45 °C for 10 min, then add a mixed solution of 0.1 g of silane coupling agent II and 2 g of acetone, continue to react for 10 min, pour into a dispersion cup, add 498 g of water under the condition of high-speed shearing at 1500 rpm, and then remove the acetone by means of vacuum distillation to obtain a water dispersion of polyurethane-urea. The dispersion has a solid content of 49 wt% and an average particle size of 201 nm measured by laser coherence method in the dispersion phase, the pH value is 7.3, and the acid value is 0.2 mg KOH / g.

[0149] Comparative Example 5 (compared with Example 6, the dosage of silane coupling agent is too high)

[0150] Add 390 g of polyester polyol II (component b)), 34 g of isocyanate I (component c)), 3 g of isocyanate II (component c)), 1 g of MPEG1200 (component e)), 0.5 g of DMPA (component g)) and 43 g of acetone into a four-necked flask equipped with a reflux condenser, a thermometer and mechanical stirring. React at 80 °C and take samples every 1 h to measure NCO%. After 3 h until the NCO% reaches the theoretical content of 1.46%, stop the reaction to obtain a prepolymer with terminal isocyanate groups; cool down to about 50 °C, add 728 g of acetone and stir, mix and dissolve for 5 min, then add 2.4 g of IPDA (component f)) and 10 g A mixture of A95 (component d)) and 60 g of deionized water, react at 45 °C for 10 min, then add a mixed solution of 6.2 g of silane coupling agent I (component a)) and 20 g of acetone, continue to react for 10 min, pour into a dispersion cup, add 478 g of water under the condition of high-speed shearing at 1500 rpm, and then remove the acetone by means of vacuum distillation to obtain a water dispersion of polyurethane-urea. The dispersion has a solid content of 49 wt% and an average particle size of 201 nm measured by laser coherence method in the dispersion phase, the pH value is 7.5, and the acid value is 0.01 mg KOH / g.

[0151] Description of test method:

[0152] (I) Test of initial tack and resistance to heat and humidity:

[0153] (1) Preparation of the sample to be tested for the adhesive:

[0154] Take 100 g of the dispersion samples obtained from each of the examples and Comparative Examples 1-5, add 0.05 g of defoamer (BYK024), 0.2 g of wetting agent (Tego 245), and 0.15 g of thickener (Vesmody U604), and stir evenly for use as the sample to be tested for the adhesive.

[0155] (2) Preparation of test strips:

[0156] Pretreatment of the black rubber strip: Grind the 60 mm × 20 mm black rubber with a grinding machine, wipe it clean with methyl ethyl ketone, then wipe it 4 times with an acetone solution of 2 wt% trichloroisocyanuric acid ester (oily bismuth powder), place it in an oven at 70 °C for 2 min, take it out and let it cool for use;

[0157] Pretreatment of the white rubber strip: Grind the 60 mm × 20 mm white rubber with a grinding machine, wipe it clean with methyl ethyl ketone, then wipe it 4 times with an acetone solution of 2 wt% trichloroisocyanuric acid ester (oily bismuth powder), place it in an oven at 70 °C for 2 min, take it out and let it cool for use;

[0158] Pretreatment of the white canvas: Cut the white canvas into strips of 70 mm × 20 mm, evenly apply the sample to be tested for the adhesive on the canvas, place it in an oven at 65 °C for 6 min, take it out and let it cool for use.

[0159] (3) Performance testing:

[0160] Initial tack: Use a brush to gently brush the samples to be tested for the adhesive prepared from the dispersions of each of the examples and comparative examples on two pretreated black rubber strips respectively, brush back and forth three times respectively, then put the two black rubber strips into an oven at 65 °C at the same time, take them out after drying for 3 minutes, fold the two black rubber strips into arcs respectively, then gently contact and stick them perpendicular to each other and then pull them apart, and score the tack according to the magnitude of the force when pulling apart after sticking. (The tack is scored from low to high as 5 grades: A, A+, A++, A+++, A++++).

[0161] Moisture and heat resistance: Evenly apply the samples to be tested for the adhesive prepared from the dispersions of each of the examples and comparative examples on the pretreated white rubber strips and white canvas respectively, activate them in an oven at 65 °C for 3 min, take them out, stick them and press them together through a press (20 kgf × 3 s), place the bonded strips in a constant temperature and humidity chamber for 24 h. After 24 h, hang the strips in a constant temperature and humidity box at a temperature of 70 °C and a humidity of 95%, load 1 Kg on the side of the white canvas of the bonded strips, and record the time when the white canvas and the white rubber are completely peeled off.

[0162] (2) Moisture and heat resistance performance test at 70 °C for 4 days:

[0163] The test was carried out with reference to the heat and humidity resistance test method in “(1) Test of initial adhesiveness and heat and humidity resistance”. The only difference was that the adhesive sample to be tested was prepared as follows: Take 100 g of the dispersion samples obtained in each example and each comparative example, seal them, place them in an oven at 70 °C for 4 days, take them out, and restore them to room temperature. Then add 0.05 g of defoamer (BYK024), 0.2 g of wetting agent (Tego 245), and 0.15 g of thickener (Vesmody U604), and stir evenly for use as the adhesive sample to be tested.

[0164] Performance comparison between examples and comparative examples

[0165]

[0166]

[0167] It can be seen from the above table that compared with Comparative Examples 1-5, the dispersion obtained in the examples of the present invention has better heat and humidity resistance and hydrolysis resistance when used as the main component as an adhesive, and at the same time can take into account good initial adhesiveness, having great practical application value.

[0168] Compared with Example 1 and Comparative Example 2, the acid value of the dispersion was not controlled between 0.005 mgKOH / g and 5 mgKOH / g, and it was impossible to take into account good heat and humidity resistance and hydrolysis resistance at the same time. Compared with Example 1 and Comparative Example 3, no silane coupling agent was used, and it was impossible to take into account good heat and humidity resistance and hydrolysis resistance at the same time. Compared with Example 1 and Comparative Examples 4 and 5, the dosage of the silane coupling agent did not meet the requirements of the present invention, and it was also impossible to take into account good heat and humidity resistance, hydrolysis resistance and initial adhesiveness at the same time.

[0169] It is easy to understand that the above examples are only examples given clearly and do not mean that the present invention is limited thereto. For those of ordinary skill in the art, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to enumerate all the embodiments here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. An aqueous dispersion of a polyurethane or a polyurethaneurea, characterized in that, Prepared by reacting a composition comprising the following components: a) At least one siloxane compound, the general formula of the siloxane compound being Wherein the group R contains at least one NCO-reactive group, and at least two of the groups R1, R2 and R3 are the same or different alkoxy groups, and the alkoxy group is selected from methoxy or ethoxy; b) At least one polyol with a functionality of 2 - 4; c) At least one polyisocyanate; d) At least one hydrophilic compound, and the hydrophilic group of the hydrophilic compound contains one or more of ionic groups or latent ionic groups, and the hydrophilic compound contains 2 - 3 NCO - reactive groups; e) At least one monofunctional non - ionic hydrophilic compound reactive with NCO; Optional component f): At least one compound containing 1 - 3 amino groups and no COOH group; Optionally, the raw materials for preparing the aqueous dispersion further include optional component g): At least one compound containing a COOH group and simultaneously containing 1 - 3 amino groups or hydroxyl groups; Based on the total mass of components a) - g), the amounts of each component are as follows: component a) 0.05 - 1.25 wt%, component b) 75 - 92 wt%, component c) 7 - 17 wt%, component d) 0.5 - 2.5 wt%, component e) 0.02 - 1.5 wt%, component f) 0 - 2.5 wt%, component g) 0 - 3 wt%; And, the acid value of the aqueous dispersion is between 0.005 mgKOH / g - 5 mgKOH / g, preferably 0.01 mgKOH / g - 3 mgKOH / g, more preferably between 0.02 mgKOH / g - 3 mgKOH / g.

2. The aqueous dispersion according to claim 1, characterized in that, In the process of preparing the aqueous dispersion, the prepolymer of terminal isocyanate is prepared in the presence of trace alkali metal ions, and based on the total mass of the prepolymer of terminal isocyanate being 100%, the content of the alkali metal ions is 0.1 ppm - 30 ppm, preferably 0.1 - 23 ppm, and the alkali metal ions are selected from Na + and / or K + ; The prepolymer of the terminal isocyanate is obtained by reacting raw materials comprising at least component b), component c) and component e).

3. The aqueous dispersion according to any one of claims 1-2, characterized in that, In component a), the NCO - reactive group in the group R is selected from one or more of hydroxyl group, primary amino group and secondary amino group; preferably, component a) has at least one primary amino group or secondary amino group; preferably, the group R is a saturated fatty alkyl chain having at least one primary amino group and / or secondary amino group, and optionally having an alkoxy group; Preferably, component a) is selected from one or more of bis(3 - trimethoxysilylpropyl)amine, bis(3 - triethoxysilylpropyl)amine, N - β-(aminoethyl)-γ - aminopropyltrimethoxysilane, N - β-(aminoethyl)-γ - aminopropyltriethoxysilane, N - β-(aminoethyl)-γ - aminopropylmethyldimethoxysilane, N - β-(aminoethyl)-γ - aminopropyldiethoxysilane, 3 - aminopropyltrimethoxysilane, 3 - aminopropyltriethoxysilane.

4. The aqueous dispersion according to any one of claims 1 to 3, characterized in that, In component b), the number - average molecular weight of the polyol is 500 - 10000, preferably 1000 - 5000, more preferably 1000 - 4000; Preferably, the polyol is selected from one or more of diols, triols and tetraols; Further preferably, the polyol is selected from one or more of polyadipic acid series polyester polyols, polycaprolactone polyols and polycarbonate polyols; More preferably, the polyol is selected from polyadipic acid series polyester diols with a functionality of 2 and a number - average molecular weight of 1000 - 4000.

5. The aqueous dispersion according to any one of claims 1 to 4, characterized in that, In component c), the polyisocyanate is selected from one or more of tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 1,4-diisocyanato-cyclohexane, isophorone diisocyanate, 4,4'-diisocyanato-dicyclohexyl-methane, 4,4'-diisocyanato-2,2-dicyclohexylpropane, 1,4-diisocyanatobenzene, 2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene, 4,4'-diisocyanato-diphenylmethane, 2,2'-diisocyanatodiphenylmethane, 2,4'-diisocyanatodiphenylmethane, tetramethylxylylene diisocyanate, p-xylylene diisocyanate, p-isopropylidene diisocyanate, p-phenylene diisocyanate and cyclohexane dimethylene diisocyanate; preferably hexamethylene diisocyanate and / or isophorone diisocyanate.

6. The aqueous dispersion according to any one of claims 1-5, characterized in that, In component d), the hydrophilic compound is selected from one or more of N-(2-aminoethyl)-2-aminoethanesulfonic acid, N-(3-aminopropyl)-2-aminoethanesulfonic acid, N-(3-aminopropyl)-3-aminopropanesulfonic acid, N-(2-aminoethyl)-3-aminopropanesulfonic acid and their alkali metal salts, alkaline earth metal salts and ammonium salts; preferably N-(2-aminoethyl)-2-aminoethanesulfonate.

7. The aqueous dispersion according to any one of claims 1-6, characterized in that, In component e), the number average molecular weight of the nonionic hydrophilic compound is 200 - 8000, preferably 500 - 3000; Preferably, the number of ethylene oxide units of the nonionic hydrophilic compound is 4 - 200, more preferably 12 - 75; Preferably, the nonionic hydrophilic compound is a monofunctional polyethoxy ether with a number average molecular weight of 200 - 8000 and 4 - 200 ethylene oxide units, more preferably poly(ethylene glycol) monomethyl ether with a number average molecular weight of 500 - 3000 and 12 - 75 ethylene oxide units.

8. The aqueous dispersion according to any one of claims 1-7, characterized in that, In component f), the compound containing 1 - 3 amino groups and no COOH group is one or more of aliphatic amine compounds and alicyclic amine compounds. Preferably, the amino groups contained therein are primary amine groups and / or secondary amine groups. Optionally, the compound containing 1 - 3 amino groups and no COOH group contains hydroxyl groups; Preferably, component f) is selected from one or two of isophorone diamine and N-(2-hydroxyethyl)ethylenediamine.

9. The aqueous dispersion according to any one of claims 1 - 8, characterized in that, The raw materials for preparing the aqueous dispersion include component g), and component g) is preferably selected from one or more of monohydroxycarboxylic acids, dihydroxycarboxylic acids, dihydroxydicarboxylic acids, trihydroxycarboxylic acids, monoaminocarboxylic acids, diamino carboxylic acids, triaminocarboxylic acids; Preferably, the component (g) is selected from one or more of dimethylolpropionic acid, dimethylolbutyric acid, dimethylolacetic acid, dihydroxysuccinic acid, hydroxypivalic acid, glycolic acid, hydroxypropionic acid, lysine, lactic acid, 6 - aminocaproic acid, alanine, N-(2 - aminoethyl)-β - alanine, undecanoic acid, 8 - aminocaprylic acid, 5 - aminovaleric acid, 4 - aminobutyric acid, aminobenzoic acid, 4 - (aminomethyl)cyclohexanecarboxylic acid, 2 - aminohexanoic acid, 4 - aminocyclohexanecarboxylic acid, 12 - aminododecanoic acid and 9 - aminononanoic acid, more preferably one or more of dimethylolpropionic acid, lactic acid and lysine.

10. A method for preparing an aqueous dispersion of a polyurethane or polyurethane urea according to any one of claims 1-9, characterized in that, The method comprises the following steps: S1: Reacting the component (b), the component (c) and the component (e) to form a prepolymer with terminal isocyanate groups; S2: After dissolution, continuously reacting the prepolymer with the component (d), the component (a) and optionally the component (f), and then dispersing with water; In step S1 and / or step S2, a solvent that can be partially or completely removed during the dispersion or by distillation after the dispersion is optionally used; The optional component (g) is added at any stage of step S1 and / or step S2; Meanwhile, during the preparation of the aqueous dispersion, the acid value of the obtained aqueous dispersion is controlled to be between 0.005 mg KOH / g and 5 mg KOH / g, preferably between 0.01 mg KOH / g and 3 mg KOH / g, more preferably between 0.02 mg KOH / g and 3 mg KOH / g.

11. The method according to claim 10, characterized in that, In step S1, the preparation of the prepolymer of the terminal isocyanate is carried out in the presence of trace alkali metal ions. Based on the total mass of the prepolymer of the terminal isocyanate being 100%, the content of the alkali metal ions is 0.1 ppm - 30 ppm, and the alkali metal ions are selected from Na + and / or K + .

12. The aqueous dispersion according to any one of claims 1 - 9 or the aqueous dispersion prepared by the method according to any one of claims 10 - 11 is used in the preparation of adhesives and sealants.

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