Aqueous polyisocyanate, process for its preparation and use, aqueous polyisocyanate two-component system

Abstract

The application discloses a water-based polyisocyanate, a preparation method and application thereof, and a water-based polyisocyanate two-component system. Raw materials of the water-based polyisocyanate include polyisocyanate, butanone oxime, polyether polyol, small-molecule alicyclic polyol, monol, hydroxy alkanoic acid and alkaline neutralizer. The water-based polyisocyanate has high modulus and is closed, has good hydrophilicity, good water dispersion performance, can be dispersed or dissolved in water, has good stability and construction performance, and a resin film prepared by matching the water-based polyisocyanate with water-based polyurethane and hydroxyl acrylic emulsion has high modulus.

Description

Technical Field

[0001] This invention belongs to the technical field of waterborne polyurethane, specifically relating to the preparation method and application of high-modulus blocked waterborne polyisocyanate. Background Technology

[0002] Traditional solvent-based polyurethane coatings generate large amounts of volatile organic compounds (VOCs) during preparation and application, harming the living environment and health of plants and animals. With the urgent need for environmental protection, national laws and regulations have strictly controlled VOC emissions from coatings and other products. Waterborne two-component polyurethane coatings (2K-WPU) have attracted widespread attention due to their low VOC emissions and high performance. The technological level of waterborne two-component polyurethane coatings has become an important indicator of a company's and even a country's coating competitiveness.

[0003] As a component of two-component polyurethane coatings, the waterborne technology of polyisocyanate curing agents is a prerequisite for the waterborne development of polyurethane coatings. Research on their water dispersibility, storage stability, and NCO% content has gradually become a research hotspot for 2K-WPU coatings. Researching and developing key technologies for waterborne polyisocyanate curing agents, a crucial component of 2K-WPU, and preparing high-performance waterborne polyisocyanate curing agents with excellent water dispersibility, long storage time, good resin compatibility, and superior paint formulation performance is of great significance for accelerating the development of waterborne polyurethane coatings in my country both domestically and internationally, and promoting the high-quality industrialization of related waterborne coatings.

[0004] There are two main technical approaches to hydrophilic modification of polyisocyanates: nonionic modification and ionic modification. Nonionic modification mainly uses polyethers containing active hydrogen atoms with isocyanate groups (NCO reaction activity), such as hydroxyl and amino groups. This type of modified water-dispersible polyisocyanate has been widely used, but a large amount of polyether is required to give the polyisocyanate good water dispersibility. This results in permanent hydrophilicity in the final coating film, which reduces the film's weather resistance.

[0005] Ion-modified polyisocyanates effectively address the aforementioned problem of poor water resistance in the films. The main ionic groups used are carboxyl and sulfonic acid groups. Patents CN106459332A and CN1113105814A introduce carboxyl groups into the polyurethane chain using carboxyl polyols and hydroxyalkanoates, followed by neutralization and dispersion to prepare waterborne polyurethane dispersions. However, because the melting points of the carboxyl polyols used, such as dimethylolpropionic acid (DMPA) or dimethylolbutyric acid (DMBA), are greater than 130°C, a co-solvent needs to be added to the system to dissolve them and lower the reaction temperature. Furthermore, due to the relatively small steric hindrance effect of hydroxyalkanoates, the carboxyl groups can react with excess isocyanate groups in the system, resulting in a small amount of hydroxyalkanoates added in the aforementioned patents; the hydrophilicity is mainly provided by the carboxyl polyols. Sulfonic acid compounds used in sulfonic acid modification, such as aminosulfonic acid, have very high melting points, requiring a long time to react completely with the polyisocyanate, even at high temperatures. During prolonged reactions, sulfonic acid groups readily dehydrate and react with each other to form sulfonic anhydrides, which weakens hydrophilicity and emulsifurity. Using a larger amount of aminosulfonic acid compounds to improve hydrophilicity inevitably reduces the NCO group content, affecting the crosslinking properties of the modified polyisocyanate. Patent CN116178672A, to ensure a more complete reaction between aminosulfonic acid and isocyanate, adds a small amount of hydroxycarboxylic acid, such as 12-hydroxystearic acid, to the system. The purpose is that when the hydroxycarboxylic acid and aminosulfonic acid participate in the reaction together, the hydroxycarboxylic acid melts into a liquid, wetting and encapsulating the solid aminosulfonic acid, making it easier for it to enter the polyisocyanate and react. Summary of the Invention

[0006] The present invention aims to provide a high-modulus blocked waterborne polyisocyanate and its preparation method. The high-modulus blocked waterborne polyisocyanate has good water dispersibility, good storage stability, controllable reactivity, good compatibility with polyurethane resin, high modulus after coating and film formation, and the preparation method is simple and easy to operate.

[0007] A second objective of this invention is to provide the application of the aforementioned high-modulus blocked waterborne polyisocyanate in the preparation of waterborne polyurethane coatings.

[0008] To achieve the first objective of the invention, the following technical solution is adopted:

[0009] A high-modulus blocked waterborne polyisocyanate, wherein the high-modulus blocked waterborne polyisocyanate is prepared from the following raw materials in parts by weight:

[0010]

[0011] In this invention, the high-modulus closed-type waterborne polyisocyanate, wherein the polyisocyanate component a) is one or more of aliphatic, alicyclic, aryliphatic and / or aromatic polyisocyanates or modified polyisocyanates with an average isocyanate functionality of 2.0-5.0 and an NCO content of 7.0-32.0 wt%.

[0012] As a preferred embodiment, the polyisocyanate component is a diisocyanate with a molecular weight of 100-500 and having aliphatic, alicyclic, aryl, or aromatic bonds, preferably tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 4,4'-dicyclohexylpropane diisocyanate, 1,4-phenyl diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'- and 2,4'-diphenylmethane diisocyanate, tetramethylxylyl diisocyanate, and terephthalic diisocyanate, or a mixture of these diisocyanates;

[0013] As a preferred embodiment, the polyisocyanate component is a modified polyisocyanate having an isocyanurate group based on one or more of 1,6-hexanediisocyanate, isophorone diisocyanate and 4,4'-dicyclohexylmethane diisocyanate.

[0014] In this invention, the general structural formula of the polyether polyol is as follows:

[0015]

[0016] Wherein, R represents a hydrogen atom or an alkyl group having 1-12 carbon atoms, such as methyl, ethyl, etc., more preferably a hydrogen atom or an alkyl group having 1-4 carbon atoms; A represents a hydrogen atom or methyl; n represents the number of repetitions of vinyl oxide or propylene oxide, n = 8 to 45, preferably 10 to 22.

[0017] The number average molecular weight of the polyether polyol used in this invention is 500-2000, preferably 500-1200.

[0018] In this invention, the single alcohol used as a capping agent is a small molecule single alcohol with 1 hydroxyl group in C4-C12, preferably one or more of n-butanol, isobutanol, sec-butanol, n-hexanol, isooctanol, and isoamyl alcohol, with n-butanol and isooctanol being preferred.

[0019] In this invention, the small molecule alicyclic polyol is one or more of 1,4-cyclohexyldiethanol, 1,2-cyclohexanediol, and 1,4-cyclohexanediol, preferably 1,4-cyclohexanediethanol.

[0020] In this invention, the hydroxyalkanoic acid is a monohydric alcohol containing straight-chain or branched C6-C24 segment fatty acids, preferably one or more of 12-hydroxystearic acid, 6-hydroxydodecanoic acid, 11-hydroxyhexadecanoic acid, and 10-hydroxystearic acid, preferably 12-hydroxystearic acid and 10-hydroxystearic acid.

[0021] In this invention, the alkaline neutralizing agent is an organic alkaline small molecule compound and / or an inorganic alkaline small molecule compound, preferably one or more of sodium hydroxide, potassium hydroxide, triethylamine, N,N-dimethylethanolamine, dimethylcyclohexylamine, triethanolamine, methyldiethanolamine, diisopropanolamine, ethyldiisopropylamine, diisopropylcyclohexylamine, N-methylmorpholine, 2-amino-2-methyl-1-propanol, and ammonia water, preferably one or more of sodium hydroxide, triethylamine, and N,N-dimethylethanolamine, and more preferably sodium hydroxide.

[0022] The preparation method of the high-modulus blocked waterborne polyisocyanate of the present invention includes the following steps: according to the proportion,

[0023] (1) Polyisocyanate, polyether polyol, small molecule alicyclic polyol and monool are prepolymerized in the presence of a catalyst until the NCO in the system reaches the theoretical value, and prepolymer a is generated.

[0024] (2) Add methyl ethyl ketone oxime dropwise to prepolymer a for end-capping reaction. After the addition is complete, keep warm for 0.5-2h to obtain the end-capped product;

[0025] (3) Add hydroxyalkyl acid to the end-capped product of step (2), react until the NCO in the system reaches the theoretical value, and then add an alkaline neutralizing agent and react for 5-10 minutes to obtain prepolymer b;

[0026] (4) Add deionized water droplets to prepolymer b according to the required solid content to disperse and obtain high modulus closed waterborne polyisocyanate.

[0027] In this invention, small molecule alicyclic polyols are used for chain extension. Since alicyclic polyols have a certain rigidity, the prepared closed-type waterborne polyisocyanate, when combined with waterborne hydroxyl acrylic dispersion or waterborne polyurethane containing hydroxyl groups, has a higher modulus than that obtained by chain extension with small molecule alicyclic polyols.

[0028] In this invention, the methyl ethyl ketone (MEK) oxime capping agent is added after the first prepolymerization reaction to allow the polyisocyanate to fully extend the chain with the small-molecule alicyclic polyol before capping. Those skilled in the art understand that the more reactive MEK oxime preferentially reacts with the isocyanate groups. If the capping agent and chain extender are added to the reaction system simultaneously, the prepolymer after capping will have fewer remaining isocyanate groups and steric hindrance, reducing the chain extension degree of the polyol and lowering the molecular weight. Adding the MEK oxime capping agent after the first prepolymerization reaction results in a prepolymer with a larger molecular weight, exhibiting higher stability in water compared to smaller molecular weight prepolymers. Since MEK oxime has high reactivity with isocyanates, the dropwise addition method effectively controls the temperature rise caused by the capping reaction, reducing reaction risk and making the reaction more controllable.

[0029] The hydroxyalkyl acid described in this invention has a low melting point. Compared with other organic acids, choosing hydroxyalkyl acid as the hydrophilic group allows for reactions to be carried out at relatively low temperatures. Hydroxyalkyl acid contains both hydroxyl and carboxyl groups, both of which can react with isocyanate groups, but the hydroxyl group exhibits higher reactivity. In this invention, the hydroxyalkyl acid is added in the third step of the reaction, and the remaining molar number of isocyanate groups after the second-step end-capping reaction is controlled to be the same as the molar number of hydroxyalkyl acid groups. The aim is to reduce the probability of collisions between carboxyl groups and isocyanate groups, significantly reducing the occurrence of side reactions.

[0030] In this invention, the preparation method is preferably carried out in the presence of a catalyst, which is preferably one or a mixture of dibutyltin dilaurate, tin n-octanoate, zinc n-octanoate, tin (II) 2-ethyl-1-hexanoate, dibutyltin dichloride (IV), dibutyltin diacetate (IV), dioctyltin diacetate (IV), molybdenum glycolate, cobalt octoate, or BiCat8108, more preferably BiCat8108. The amount of catalyst added is 0.01-0.05 wt% of the total weight of the components, preferably 0.02-0.03 wt%.

[0031] In the preparation method of the high modulus blocked waterborne polyisocyanate of the present invention, the reaction temperature in step (1) is 65-80℃ and the reaction time is 60min-150min, preferably 90-120min.

[0032] In this invention, the process conditions for the end-capping reaction in step (2) include: a reaction temperature of 65-80°C and a dropping time of 60-90 min.

[0033] In this invention, the reaction conditions of the end-capped product and hydroxyalkyl acid in step (3) include: a reaction temperature of 75-85℃ and a reaction time of 120-300 min, preferably 180-240 min.

[0034] Another objective of this invention is to provide a high-modulus closed-type aqueous polyisocyanate two-component system.

[0035] A high-modulus closed-cell waterborne polyisocyanate two-component system comprising a high-modulus closed-cell waterborne polyisocyanate and a waterborne hydroxyl acrylic dispersion or a waterborne polyurethane containing hydroxyl groups.

[0036] Another object of the present invention is to provide a use of a high-modulus closed-cell waterborne polyisocyanate.

[0037] Use of a high-modulus closed-type waterborne polyisocyanate, wherein the polyisocyanate is used as a curing agent component in a two-component waterborne system, preferably as a resin component in a two-component waterborne glass fiber wetting coating.

[0038] The beneficial effects of this invention are as follows:

[0039] (1) The high modulus closed-type waterborne polyisocyanate of the present invention has good hydrophilicity, good water dispersibility, good stability and workability; at the same time, a macromolecular polyol is introduced into the main chain to ensure good compatibility with polyurethane resin.

[0040] (2) This invention uses small-molecule alicyclic polyols for chain extension, introducing a rigid structure and improving the modulus of the coating film prepared in combination with resin. Furthermore, it innovatively adds hydroxyalkyl acids after prepolymerization and end-capping reactions, reducing the side reactions between carboxyl groups and isocyanates.

[0041] (3) The preparation method of the high modulus blocked polyisocyanate of the present invention is simple, does not contain organic solvents such as acetone, and is easy to operate. Detailed Implementation

[0042] The following specific embodiments further illustrate the technical solution and effects of the present invention. These embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Simple modifications made to the present invention based on the concept of the present invention are all within the scope of protection claimed by the present invention.

[0043] The test methods used in the embodiments or comparative examples are described below:

[0044] The resin film modulus and tensile strength were tested in accordance with ASTM D412, "Rubber and Elastomers - Determination of Tensile Strength".

[0045] Acetone resistance test: Immerse the finished sample in acetone solution for 1 hour, remove and dry it, and observe the condition of the paint film.

[0046] Water resistance test: Immerse the finished sample in 25℃ deionized water for 24 hours, remove it, wipe off the water stains, and observe the condition of the paint film.

[0047] Acetone resistance GB / T 1730 "Determination of Hardness of Paint Film - Pendulum Damping Test";

[0048] Yellowing resistance test: The resin film was baked in an oven at 200℃ for 30 minutes, and the color change before and after was observed.

[0049] 30-day thermal storage stability test: Place the sample to be tested in a 50℃ constant temperature oven and test whether stratification occurs after 30 days.

[0050] The sources of raw materials used in the following examples and comparative examples are shown in Table 1.

[0051] Table 1 Source of Raw Materials

[0052]

[0053]

[0054] Example 1

[0055] Add 240g to the four-necked flask HT-600, 1.5g MPEG1200, 1.5g isooctyl alcohol, 7.5g CHDM, and 0.06g BiCat8108 were reacted at 75℃ for 2.5h to obtain a prepolymer. Maintaining the reaction system at 75℃, 96g of butanone oxime was added dropwise to a four-necked flask using a peristaltic pump over 1h. After the addition was complete, the temperature was maintained for another 1h. Then, 26.2g of 12-hydroxystearic acid was added, and the reaction was carried out at 80℃ for 3h. Next, 2.83g of NaOH (dissolved in ten times its volume of water) was added for neutralization over 5min. After neutralization, the stirring speed was increased to over 500rpm, and 458g of deionized water was added dropwise to the four-necked flask using a peristaltic pump to obtain a high-modulus closed-cell aqueous polyisocyanate A1.

[0056] Example 2

[0057] Add 240g to the four-necked flask HT-100, 4.8g MPEG500, 2.4g n-butanol, 9.6g 1,2-cyclohexanediol, and 0.12g BiCat8108 were reacted at 65℃ for 1.5h to obtain a prepolymer. Maintaining the reaction system at 65℃, 84g of butanone oxime was added dropwise to a four-necked flask using a peristaltic pump over 1.5h. After the addition was complete, the temperature was maintained for another 1h. Then, 36g of 12-hydroxystearic acid was added, and the reaction was carried out at 85℃ for 2h. Next, 4.7g of NaOH (dissolved in ten times its volume of water) was added for neutralization over 10min. After neutralization, the stirring speed was increased to over 500rpm, and 450g of deionized water was added dropwise to the four-necked flask using a peristaltic pump to obtain a high-modulus closed-cell aqueous polyisocyanate A2.

[0058] Example 3

[0059] Add 240g to the four-necked flask HT-600, 1.2g MPEG1200, 0.96g isooctyl alcohol, 4.8g CHDM, and 0.06g BiCat8108 were reacted at 80℃ for 1 hour to obtain a prepolymer. Maintaining the reaction system at 80℃, 108g of butanone oxime was added dropwise to a four-necked flask using a peristaltic pump over 1.5 hours. After the addition was complete, the temperature was maintained for another hour. Then, 18g of 12-hydroxystearic acid was added, and the reaction was carried out at 75℃ for 5 hours. Next, 2.3g of NaOH (dissolved in ten times its volume of water) was added for neutralization over 5 minutes. After neutralization, the stirring speed was increased to over 500 rpm, and 458g of deionized water was added dropwise to the four-necked flask using a peristaltic pump to obtain a high-modulus closed-cell aqueous polyisocyanate A3.

[0060] Example 4

[0061] 240g NZ1, 3g MPEG1200, 4.8g isooctanol, 7.5g CHDM, and 0.06g BiCat8108 were added to a four-necked flask, and the mixture was heated to 75℃ and reacted for 1.5h to obtain a prepolymer. Maintaining the reaction system at 75℃, 90g of butanone oxime was added dropwise to the four-necked flask using a peristaltic pump over 1h. After the addition was complete, the temperature was maintained for another 1h. Then, 30g of 10-hydroxystearic acid was added, and the mixture was reacted at 80℃ for 3h. Then, 3.2g of NaOH (dissolved in ten times its volume of water) was added for neutralization over 5min. After neutralization, the stirring speed was increased to over 500rpm, and 450g of deionized water was added dropwise to the four-necked flask using a peristaltic pump to obtain a high-modulus closed-cell aqueous polyisocyanate A4.

[0062] Comparative Example 1

[0063] Add 240g to the four-necked flask HT-600, 1.5g MPEG1200, 1.5g isooctyl alcohol, 7.5g CHDM, 96g butanone oxime, and 0.06g BiCat8108 were reacted at 75℃ for 3.5h to obtain a prepolymer. Then, 26.2g 12-hydroxystearic acid was added, and the reaction was carried out at 80℃ for 3h. Then, 2.83g NaOH (dissolved in ten times its volume of water) was added for neutralization, and the neutralization time was 5min. After neutralization, the stirring speed was increased to above 500rpm, and 458g deionized water was added dropwise into a four-necked flask using a peristaltic pump to obtain a high-modulus closed-cell aqueous polyisocyanate A1'.

[0064] Comparative Example 2

[0065] Add 240g to the four-necked flask HT-600, 1.5g MPEG1200, 1.5g isooctyl alcohol, 7.5g CHDM, and 0.06g BiCat8108 were reacted at 75℃ for 2.5h to obtain a prepolymer. Then, 26.2g 12-hydroxystearic acid was added, and the reaction was carried out at 80℃ for 3h. The reaction system was cooled to 75℃, and 96g of butanone oxime was added dropwise to a four-necked flask using a peristaltic pump over 1h. After the addition was complete, the mixture was kept at the same temperature for another 1h. Then, 2.83g NaOH (dissolved in ten times its volume of water) was added for neutralization over 5min. After neutralization, the stirring speed was increased to over 500rpm, and 458g of deionized water was added dropwise to the four-necked flask using a peristaltic pump to obtain a high-modulus closed-cell aqueous polyisocyanate A2'.

[0066] Comparative Example 3

[0067] Add 240g to the four-necked flask HT-600, 1.5g MPEG1200, 1.5g isooctanol, 3.96g 1,2-propanediol, and 0.06g BiCat8108 were reacted at 75℃ for 2.5h to obtain a prepolymer. Maintaining the reaction system at 75℃, 96g of butanone oxime was added dropwise to a four-necked flask using a peristaltic pump over 1h. After the addition was complete, the temperature was maintained for another 1h. Then, 26.2g of 12-hydroxystearic acid was added, and the reaction was carried out at 80℃ for 3h. Next, 2.83g of NaOH (dissolved in ten times its volume of water) was added for neutralization over 5min. After neutralization, the stirring speed was increased to over 500rpm, and 458g of deionized water was added dropwise to the four-necked flask using a peristaltic pump to obtain a high-modulus closed-cell aqueous polyisocyanate A3'.

[0068] Comparative Example 4

[0069] Add 240g to the four-necked flask HT-600, 1.5g MPEG1200, 1.5g isooctyl alcohol, 7.5g CHDM, and 0.06g BiCat8108 were reacted at 75℃ for 2.5h to obtain a prepolymer. Maintaining the reaction system at 75℃, 96g of butanone oxime was added dropwise to a four-necked flask using a peristaltic pump over 1h. After the addition was complete, the temperature was maintained for another 1h. Then, 6.5g of dimethylolbutyric acid was added, and the reaction was carried out at 80℃ for 3h. Next, 2.83g of NaOH (dissolved in ten times its volume of water) was added for neutralization over 5min. After neutralization, the stirring speed was increased to over 500rpm, and 458g of deionized water was added dropwise to the four-necked flask using a peristaltic pump to obtain a high-modulus closed-cell aqueous polyisocyanate A4'.

[0070] Performance testing:

[0071] The high-modulus blocked waterborne polyisocyanates A1-4 and A1'-4' prepared in Examples 1-4 and Comparative Examples 1-4 were mixed with Wanhua Chemical's hydroxyl-containing waterborne polyurethane 3238 waterborne epoxy emulsion at a ratio of 1:10. The mixture was then baked in an oven at 50°C for 15 hours, and then baked in an oven at 140°C for 3 hours to prepare resin films. The resin films were numbered Q1-4 and Q1'-4', respectively, and then various tests were performed according to the corresponding test methods.

[0072] The resin film was tested according to the corresponding test methods, and the performance test results are shown in Table 2.

[0073] Table 2 Performance of Resin Films Q1-4 and Q1'-3'

[0074]

[0075]

[0076] All tests were conducted in accordance with the aforementioned standards, as detailed in the aforementioned test methods section. The results of the water resistance, acetone resistance, and yellowing resistance tests were graded from 0 to 5, with 5 being the best and 0 being the worst.

Claims

1. An aqueous polyisocyanate, prepared from the following raw materials in parts by weight: Polyisocyanate 1; Butanone oxime 0.35-0.45; Polyether polyol 0.005-0.02; Small molecule alicyclic polyols, 0.02-0.04; Monools 0.004-0.02; Hydroxyalkyl acids 0.075-0.15; Alkaline neutralizing agent 0.01-0.02; The general structural formula of the polyether polyol is as follows: Formula (II); in, R represents an alkyl group with 1-12 carbon atoms; A represents a hydrogen atom or a methyl group; n represents the repeating number of vinyl oxide or propenyl oxide, n=8~45; The unit alcohol is a small molecule unit alcohol with one hydroxyl group in a C4-C12 structure; The small molecule alicyclic polyol is one or more of 1,4-cyclohexyldiethanol, 1,2-cyclohexanediol, and 1,4-cyclohexanediol; The hydroxyalkyl acid is a monohydric alcohol containing straight-chain or branched C6-C24 segment fatty acids; The method for preparing the aqueous polyisocyanate includes the following steps: according to the proportion, (1) Polyisocyanate, polyether polyol, small molecule alicyclic polyol and monool are prepolymerized in the presence of a catalyst until the NCO in the system reaches the theoretical value, and prepolymer a is generated. (2) Butanone oxime was added dropwise to prepolymer a for end-capping reaction. After the addition was completed, the mixture was kept warm for 0.5-2 h to obtain the end-capped product. (3) Add hydroxyalkyl acid to the end-capped product of step (2), react until the NCO in the system reaches the theoretical value, and then add an alkaline neutralizing agent and react for 5~10 min to obtain prepolymer b; (4) Add deionized water droplets to prepolymer b according to the required solid content to disperse and obtain high modulus blocked waterborne polyisocyanate.

2. The aqueous polyisocyanate according to claim 1, characterized in that, The polyisocyanate component is one or more of aliphatic, alicyclic, aryliphatic, and aromatic polyisocyanates or modified polyisocyanates with an average isocyanate functionality of 2.0-5.0 and an NCO content of 7.0-32.0 wt%.

3. The aqueous polyisocyanate according to claim 2, characterized in that, The polyisocyanate component is a diisocyanate with a molecular weight of 100-500 and exhibiting aliphatic, alicyclic, aryl, or aromatic bonds.

4. The aqueous polyisocyanate according to claim 2, characterized in that, The polyisocyanate component is one or more selected from tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 4,4'-dicyclohexylpropane diisocyanate, 1,4-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'- and 2,4'-diphenylmethane diisocyanate, tetramethylxylyl diisocyanate, terephthalic diisocyanate, and modified polyisocyanates.

5. The aqueous polyisocyanate according to claim 2, characterized in that, The polyisocyanate component is selected from one or more modified polyisocyanates having isocyanurate groups based on 1,6-hexanediisocyanate, isophorone diisocyanate and 4,4'-dicyclohexylmethane diisocyanate.

6. The aqueous polyisocyanate according to claim 1, characterized in that, In formula (II), R represents an alkyl group with 1-4 carbon atoms, and n = 10-22.

7. The aqueous polyisocyanate according to claim 6, characterized in that, In formula (II), R represents methyl or ethyl.

8. The aqueous polyisocyanate according to claim 1, characterized in that, The number average molecular weight of the polyether polyol is 500-2000.

9. The aqueous polyisocyanate according to claim 1, characterized in that, The number average molecular weight of the polyether polyol is 500-1200.

10. The aqueous polyisocyanate according to claim 1, characterized in that, The monool is one or more of n-butanol, isobutanol, sec-butanol, n-hexanol, isooctanol, and isoamyl alcohol.

11. The aqueous polyisocyanate according to claim 1, characterized in that, The hydroxyalkyl acid is one or more of 12-hydroxystearic acid, 6-hydroxydodecanoic acid, 11-hydroxyhexadecanoic acid, and 10-hydroxystearic acid.

12. A waterborne polyisocyanate two-component system comprising the waterborne polyisocyanate of any one of claims 1-11 and a waterborne hydroxyl acrylic dispersion or a waterborne polyurethane containing hydroxyl groups.

13. The use of an aqueous polyisocyanate, characterized in that, The aqueous polyisocyanate according to any one of claims 1-11 is used as a curing agent component in a two-component aqueous system.

14. The use according to claim 13, characterized in that, The aforementioned waterborne polyisocyanate is used as a curing agent for two-component waterborne glass fiber impregnation agents.

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