A polyisocyanate composition and its preparation method and application

Abstract

The present invention relates to a polyisocyanate composition and a preparation method and application thereof, belonging to the technical field of waterborne compositions. The polyisocyanate composition described herein comprises: (1) an isocyanate group; (2) at least one of the groups shown in formulas (1a), (1b), and (1c); (3) a sulfonate group bonded in the form of a urea bond or a carbamate bond, and / or a polyethylene glycol monoalkyl ether group bonded in the form of a carbamate bond; wherein: the content of the isocyanate group is 12.0-26.0wt%; the total molar amount of Si(OR)3 groups, the total molar amount of sulfonate groups and / or polyethylene glycol monoalkyl ether groups in formulas (1a), (1b), and (1c) is 2-30% and 0.7-7% of the total molar amount of isocyanate groups, carbamate groups, and urea groups contained in the polyisocyanate composition, respectively. The waterborne coating prepared by the polyisocyanate composition has excellent water resistance, salt spray resistance, adhesion, and drying speed, and also has good gloss and hardness.

Description

Technical Field

[0001] The present invention relates to the technical field of aqueous compositions, and in particular to a polyisocyanate composition and a preparation method and application thereof. Background Art

[0002] At present, there are more and more restrictions on volatile organic compounds (VOC) in coatings. In this context, water-based coatings with water as the dispersion medium have replaced traditional solvent-based coatings in many fields due to their lower VOC content. Hydrophilic modified isocyanate crosslinkers are often used in water-based coatings. Hydrophilic modified isocyanate crosslinkers can be dispersed and emulsified in the water phase. Combined with water-based hydroxyl resins, high-performance water-based two-component polyurethane coatings comparable to solvent-based coatings can be obtained.

[0003] Patents US4433095 and US4663377 reported that a nonionic hydrophilic isocyanate crosslinking agent was synthesized using a monoalkyl-terminated polyether as a hydrophilic modifier, which can be used in water-based two-component polyurethane coatings. Patent US6767958 reported that a sulfonate-type anionic hydrophilic isocyanate crosslinking agent was synthesized using 3-(cyclohexylamine)-1-propanesulfonic acid or 3-(cyclohexylamine)-1-ethanesulfonic acid as a hydrophilic modifier, which has excellent hardness and chemical resistance. However, the water resistance, salt spray resistance, and adhesion to metal substrates of these hydrophilic isocyanate crosslinking agents are still insufficient.

[0004] In order to further improve the performance of hydrophilic isocyanate crosslinking agents, the introduction of other crosslinking groups besides isocyanate has become a research hotspot for hydrophilic isocyanate crosslinking agents. Patent CN1637106A reports that the hydrophilic isocyanate crosslinking agent is modified with the addition product of aminosilane and maleic acid diester, which can improve the peel strength of canvas and cold-rolled steel laminates. CN111116865B reports a hydrophilic isocyanate crosslinking agent modified with aminosilane with sulfonic acid groups, which can prepare a highly water-resistant water-based two-component polyurethane coating. However, in these hydrophilic isocyanate crosslinking agents, each NCO group modified by aminosilane or its derivatives is only introduced into one silane group, which also means that more NCO groups need to be consumed when more silane groups are introduced, which limits the improvement of crosslinking density, so there is room for further improvement. Summary of the invention

[0005] Based on this, the purpose of the present invention is to overcome the defects or shortcomings of the prior art and provide a polyisocyanate composition and a preparation method and application thereof. The polyisocyanate composition can be dispersed in water and can be widely used as a composition in water-based coatings to improve the performance of water-based coatings; the water-based coating prepared by the polyisocyanate composition has excellent water resistance and salt spray resistance, excellent adhesion and drying speed, and also has good gloss and hardness.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A polyisocyanate composition comprising:

[0008] (1) Isocyanate group;

[0009] (2) at least one of the groups represented by formula (1a), (1b) or (1c);

[0010]

[0011] Wherein, X is a C1-C8 alkylene group, Y is a monovalent C1-C8 alkyl group, and R is a methyl group or an ethyl group;

[0012] (3) Sulfonate groups bonded in the form of urea bonds or carbamate bonds, and / or polyethylene glycol monoalkyl ether groups bonded in the form of carbamate bonds;

[0013] In the polyisocyanate composition: the content of isocyanate groups is 12.0-26.0wt% (i.e., the NCO value is 12.0-26.0%); the total molar amount of Si(OR)3 groups in formula (1a), (1b), and (1c) is 2-30% of the total molar amount of isocyanate groups, carbamate groups, and urea groups contained in the polyisocyanate composition; and the total molar amount of sulfonate groups and polyethylene glycol monoalkyl ether groups is 0.7-7% of the total molar amount of isocyanate groups, carbamate groups, and urea groups contained in the polyisocyanate composition.

[0014] In the polyisocyanate composition of the present invention, it is easy for those skilled in the art to know that the group represented by formula (1a) contains a carbamate group and two Si(OR)3 groups; the group represented by formula (1b) contains a carbamate group and three Si(OR)3 groups; the group represented by formula (1c) contains a urea group and two Si(OR)3 groups; the sulfonate group bonded in the form of a urea bond or a carbamate bond contains a urea group or a carbamate group, and a sulfonate group; the polyethylene glycol monoalkyl ether group bonded in the form of a carbamate bond contains a carbamate group and a polyethylene glycol monoalkyl ether group.

[0015] The polyisocyanate composition of the present invention has a relatively high NCO value (i.e., the NCO value is 12.0-26.0%) and a high-density silane group. The silane group will hydrolyze and crosslink after contacting the aqueous phase, thereby accelerating the curing speed. The silane group will also form a bond with the metal substrate to increase adhesion and water and salt spray resistance.

[0016] The inventors of the present invention have found through repeated studies that the group structures represented by formulas (1a), (1b) and (1c) contain two or three Si(OR)3 groups (silane groups). On the one hand, the density of Si(OR)3 groups in the polyisocyanate composition can be increased. On the other hand, the distances between the Si(OR)3 groups in the group structures represented by formulas (1a), (1b) and (1c) are relatively close. Surprisingly, we found that in the scheme of the present invention, two or three Si(OR)3 groups with relatively close distances in the group structures represented by formulas (1a), (1b) and (1c) have a synergistic effect. Compared with the conventional scheme in which only one Si(OR)3 group is introduced, even if the polyisocyanate composition has the same Si(OR)3 group content, the water-based coating prepared by the polyisocyanate composition of the present invention has better water resistance, salt spray resistance, adhesion and drying speed. In the polyisocyanate composition of the present invention, the total molar amount of Si(OR)3 groups in the group structure shown in formula (1a), (1b) and (1c) is 2-30% of the total molar amount of isocyanate groups, carbamate groups and urea groups contained in the polyisocyanate composition. If the proportion of the total molar amount of Si(OR)3 groups in the formula (1a), (1b) and (1c) is too low, the water resistance, salt spray resistance, adhesion and drying speed of the coating film formed after the polyisocyanate composition is used in the water-based coating are poor. If the proportion of the total molar amount of Si(OR)3 groups in the formula (1a), (1b) and (1c) is too high, the polyisocyanate composition is used in the water-based coating, has poor compatibility with the resin, and the gloss and hardness of the coating film formed are poor.

[0017] In order to ensure good compatibility in aqueous systems, the polyisocyanate composition of the present invention introduces hydrophilic groups, i.e., sulfonate groups bonded in the form of urea bonds or carbamate bonds and / or polyethylene glycol monoalkyl ether groups bonded in the form of carbamate bonds, and utilizes the sulfonate groups and / or polyethylene glycol monoalkyl ether groups therein to increase the compatibility of the polyisocyanate composition in aqueous systems. In the polyisocyanate composition of the present invention, the total molar amount of the sulfonate groups and / or polyethylene glycol monoalkyl ether groups is 0.7-7% of the total molar amount of the isocyanate groups, carbamate groups, and urea groups contained in the polyisocyanate composition. If the proportion of sulfonate groups and / or polyethylene glycol monoalkyl ether groups is too low, the compatibility of the polyisocyanate composition in the aqueous system will deteriorate, affecting the gloss and surface effect of the coating; if the proportion of sulfonate groups and / or polyethylene glycol monoalkyl ether groups is too high, it will also cause too many hydrophilic groups to remain in the coating, thereby affecting the water resistance and salt spray resistance.

[0018] As a preferred embodiment, the polyisocyanate composition of the present invention is a mixture of aliphatic polyisocyanates, and the mixture has the three types of groups (1), (2) and (3) above. That is, among the three types of groups (1), (2) and (3) above, the isocyanate groups are isocyanate groups on aliphatic polyisocyanates; the groups represented by formulas (1a), (1b) and (1c) are derived from isocyanate groups on aliphatic polyisocyanates; the sulfonate groups bonded in the form of urea bonds or carbamate bonds, and / or the polyethylene glycol monoalkyl ether groups bonded in the form of carbamate bonds are derived from isocyanate groups on aliphatic polyisocyanates.

[0019] As a preferred solution, the group represented by formula (1a) is obtained by reacting an isocyanate group on an aliphatic polyisocyanate with a compound represented by formula (2a) for amine esterification, followed by an addition reaction with trimethoxy monohydrogen silicon and / or triethoxy monohydrogen silicon;

[0020]

[0021] In formula (2a), X is a C1-C8 alkylene group, and Y is a monovalent C1-C8 alkyl group.

[0022] The isocyanate group on the aliphatic polyisocyanate undergoes an amine reaction with the hydroxyl group in the compound represented by formula (2a) to generate a reaction product containing a carbamate group; the two olefinic bonds on the reaction product then undergo an addition reaction with trimethoxy monohydrogen silicon and / or triethoxy monohydrogen silicon to obtain a group represented by formula (1a); thereby, the group represented by formula (1a) has a carbamate group and two Si(OR)3 groups.

[0023] As a preferred solution, the group represented by formula (1b) is obtained by reacting an isocyanate group on an aliphatic polyisocyanate with a compound represented by formula (2b) for amine esterification, followed by an addition reaction with trimethoxy monohydrogen silicon and / or triethoxy monohydrogen silicon;

[0024]

[0025] In formula (2b), X is a C1-C8 alkylene group.

[0026] The isocyanate group on the aliphatic polyisocyanate undergoes an amine reaction with the hydroxyl group in the compound represented by formula (2b) to generate a reaction product containing a carbamate group; the three olefinic bonds on the reaction product then undergo an addition reaction with trimethoxymonohydrogen silicon and / or triethoxymonohydrogen silicon to obtain a group represented by formula (1b); thereby, the group represented by formula (1b) has a carbamate group and three Si(OR)3 groups.

[0027] As a preferred solution, the group represented by formula (1c) is obtained by the reaction of the isocyanate group on the aliphatic polyisocyanate with bis(3-trimethoxysilylpropyl)amine and / or bis(3-triethoxysilylpropyl)amine.

[0028] The isocyanate group on the aliphatic polyisocyanate reacts with bis(3-trimethoxysilylpropyl)amine and / or bis(3-triethoxysilylpropyl)amine to obtain a group represented by formula (1c); thereby, the group represented by formula (1c) has a urea group and two Si(OR)3 groups.

[0029] As a preferred solution, the sulfonate group bonded in the form of a urea bond is obtained by reacting the isocyanate group on the aliphatic polyisocyanate with aminosulfonic acid.

[0030] The isocyanate groups on the aliphatic polyisocyanate react with the amino groups on the aminosulfonic acid to obtain a reaction product having a urea group and a sulfonate group, ie, a sulfonate group bonded in the form of a urea bond.

[0031] Preferably, the aminosulfonic acid is at least one of 2-(cyclohexylamino)ethanesulfonic acid, 3-(cyclohexylamino)propanesulfonic acid and 4-(cyclohexylamino)butanesulfonic acid.

[0032] Further, the sulfonate groups bonded in the form of urea bonds are isocyanate groups on aliphatic polyisocyanates reacted with aminosulfonic acid, and then at least one of N, N-dimethylbutylamine, N, N-diethylmethylamine, N, N-diisopropylethylamine, N, N-dimethylcyclohexylamine, N-methylpiperidine, and N-ethylmorpholine is added at a molar amount of 20 mol% or more based on the aminosulfonic acid for neutralization. By adding 20 mol% or more of the above-mentioned amine compounds based on the molar amount of aminosulfonic acid for neutralization, part of the sulfonate groups bonded in the form of urea bonds (more than 20 mol%) exist in the form of neutralized sulfonate groups, which can improve the compatibility of the polyisocyanate composition in the aqueous system. If the degree of neutralization and salt formation is too low, the hydrophilicity will be insufficient, affecting the compatibility of the polyisocyanate composition in the aqueous system. Preferably, at least one of N,N-dimethylbutylamine, N,N-diethylmethylamine, N,N-diisopropylethylamine, N,N-dimethylcyclohexylamine, N-methylpiperidine and N-ethylmorpholine is added in an amount equivalent to the molar amount of aminosulfonic acid for neutralization. That is, among the sulfonate groups bonded in the form of urea bonds, all the sulfonate groups are present in the form of neutralized sulfonate groups, and the water solubility of the polyisocyanate composition is optimal.

[0033] As a preferred solution, the sulfonate group bonded in the form of a carbamate bond is obtained by reacting the isocyanate group on the aliphatic polyisocyanate with hydroxysulfonic acid.

[0034] The isocyanate groups on the aliphatic polyisocyanate react with the hydroxyl groups on the hydroxysulfonic acid to give a reaction product having a carbamate group and a sulfonate group, ie, the sulfonate group is bonded in the form of a carbamate bond.

[0035] Further, the sulfonate groups bonded in the form of carbamate bonds are isocyanate groups on aliphatic polyisocyanates reacted with hydroxysulfonic acid, and then at least one of N, N-dimethylbutylamine, N, N-diethylmethylamine, N, N-diisopropylethylamine, N, N-dimethylcyclohexylamine, N-methylpiperidine, and N-ethylmorpholine is added at a molar amount of 20 mol% or more of hydroxysulfonic acid for neutralization. Similarly, by adding more than 20 mol% of the above-mentioned amine compounds based on the molar amount of hydroxysulfonic acid for neutralization, part of the sulfonate groups bonded in the form of carbamate bonds (more than 20 mol%) exist in the form of neutralized sulfonate groups, which can improve the compatibility of the polyisocyanate composition in the aqueous system. If the degree of neutralization and salt formation is too low, the hydrophilicity will be insufficient, affecting the compatibility of the polyisocyanate composition in the aqueous system. Preferably, at least one of N,N-dimethylbutylamine, N,N-diethylmethylamine, N,N-diisopropylethylamine, N,N-dimethylcyclohexylamine, N-methylpiperidine and N-ethylmorpholine is added in an amount equivalent to the molar amount of hydroxysulfonic acid for neutralization. That is, among the sulfonate groups bonded in the form of carbamate bonds, all the sulfonate groups are present in the form of neutralized sulfonate groups, and the water solubility of the polyisocyanate composition is optimal.

[0036] Preferably, the hydroxysulfonic acid is at least one of 2-hydroxyethanesulfonic acid, 3-hydroxypropanesulfonic acid, 4-hydroxybutanesulfonic acid, 5-hydroxypentanesulfonic acid, 6-hydroxyhexanesulfonic acid, hydroxybenzenesulfonic acid and hydroxy(methyl)benzenesulfonic acid.

[0037] As a preferred solution, the polyethylene glycol monoalkyl ether group bonded in the form of a carbamate bond is obtained by reacting the isocyanate group on an aliphatic polyisocyanate with the polyethylene glycol monoalkyl ether.

[0038] The isocyanate groups on the aliphatic polyisocyanate react with the hydroxyl groups on the polyethylene glycol monoalkyl ether to obtain a reaction product having a urethane group and a polyethylene glycol monoalkyl ether group, that is, a polyethylene glycol monoalkyl ether group bonded in the form of a urethane bond.

[0039] Preferably, the polyethylene glycol monoalkyl ether is at least one of the structures shown in formula (2);

[0040]

[0041] In formula (2), the average value of n is 6-17, and Z is a monovalent C1-C4 alkyl group. If the n value is too low, the hydrophilicity will be insufficient, and after being introduced into the polyisocyanate composition, the compatibility of the polyisocyanate composition in the aqueous system will be affected; if the n value is too high, after being introduced into the polyisocyanate composition, the crystallinity of the polyisocyanate composition will be too strong, and it will be difficult to quickly and evenly disperse in the aqueous system.

[0042] As a preferred embodiment, the aliphatic polyisocyanate is an aliphatic polyisocyanate having at least one of a uretdione structure, an isocyanurate structure, an allophanate structure, a biuret structure, an iminooxadiazinedione structure, and an oxadiazinedione trione structure, which is formed based on at least one of 1,6-hexamethylene diisocyanate, 1,5-pentamethylene diisocyanate, and isophorone diisocyanate as a polymerization monomer.

[0043] The present invention also provides a method for preparing any of the above-mentioned polyisocyanate compositions, comprising the following steps:

[0044] (S1) reacting an aliphatic polyisocyanate with a compound represented by formula (2a) and / or a compound represented by formula (2b) to undergo an amination reaction, followed by a hydrosilylation reaction with trimethoxysilane or triethoxysilane in the presence of a heavy metal catalyst; and / or reacting an aliphatic polyisocyanate with bis(3-trimethoxysilylpropyl)amine and / or bis(3-triethoxysilylpropyl)amine;

[0045]

[0046] In formula (2a), X is a C1-C8 alkylene group, and Y is a monovalent C1-C8 alkyl group;

[0047]

[0048] In formula (2b), X is a C1-C8 alkylene group;

[0049] (S2) reacting the reaction product of step (S1) with aminosulfonic acid and / or hydroxysulfonic acid and / or polyethylene glycol monoalkyl ether to obtain the polyisocyanate composition.

[0050] In the preparation method of the present invention, the isocyanate group of the aliphatic polyisocyanate is mainly divided into three parts, one part is modified into at least one of the groups represented by formula (1a), (1b), and (1c) in step (S1); one part is modified into a sulfonate group bonded in the form of a urea bond or a carbamate bond, and / or a polyethylene glycol monoalkyl ether group bonded in the form of a carbamate bond in step (S2); and the remaining part does not participate in the reaction.

[0051] In step (S1), part of the isocyanate groups on the aliphatic polyisocyanate can undergo an amination reaction with the compound represented by formula (2a) and / or formula (2b), and the product of the amination reaction then undergoes a hydrosilylation reaction with trimethoxysilane or triethoxysilane in the presence of a heavy metal catalyst, thereby generating a group represented by formula (1a) having a carbamate group and two Si(OR)3 groups, and / or a group represented by formula (1b) having a carbamate group and three Si(OR)3 groups; and / or, part of the isocyanate groups on the aliphatic polyisocyanate can react with bis(3-trimethoxysilylpropyl)amine and / or bis(3-triethoxysilylpropyl)amine, thereby generating a group represented by formula (1c) having a urea group and two Si(OR)3 groups.

[0052] In step (S2), part of the isocyanate groups on the aliphatic polyisocyanate can react with aminosulfonic acid to obtain a reaction product having a urea group and a sulfonate group, that is, a sulfonate group bonded in the form of a urea bond; part of the isocyanate groups on the aliphatic polyisocyanate can react with hydroxysulfonic acid to obtain a reaction product having a carbamate group and a sulfonate group, that is, a sulfonate group bonded in the form of a carbamate bond; part of the isocyanate groups on the aliphatic polyisocyanate can react with polyethylene glycol monoalkyl ether to obtain a reaction product having a carbamate group and a polyethylene glycol monoalkyl ether group, that is, a polyethylene glycol monoalkyl ether group bonded in the form of a carbamate bond.

[0053] Therefore, the total molar amount of isocyanate groups, urethane groups and urea groups contained in the polyisocyanate composition is the total molar amount of isocyanate groups of the aliphatic polyisocyanate before the reaction.

[0054] As a preferred solution, the compound represented by formula (2a) is trimethylolpropane diallyl ether, that is, in the compound represented by formula (2a), X is a methylene group and Y is an ethyl group.

[0055] As a preferred solution, the compound represented by formula (2b) is pentaerythritol triallyl ether, that is, X in the compound represented by formula (2b) is methylene.

[0056] In some embodiments, an organic solvent may be added to the preparation method of the polyisocyanate composition. The selected organic solvent is an organic solvent that does not contain active hydrogen that reacts with isocyanate. The organic solvent is preferably aromatic hydrocarbons, ketones, ethers, esters, etc.

[0057] In other embodiments, in the method for preparing the polyisocyanate composition, the organic solvent may not be added. For environmental protection reasons, it is preferred that the organic solvent is not added.

[0058] The present invention further provides the use of any of the above-mentioned polyisocyanate compositions:

[0059] As an application, the present invention provides a cross-linkable composition, comprising any of the above-mentioned polyisocyanate compositions and a hydroxyl-containing aqueous resin.

[0060] As another application, specifically, any of the polyisocyanate compositions described above is used in the preparation of water-based coatings. The water-based coating comprises the crosslinkable composition (i.e., any of the polyisocyanate compositions described above and a hydroxyl-containing water-based resin). During the process of construction and drying to form a coating film, as the water evaporates, the isocyanate groups in the polyisocyanate composition react with the hydroxyl groups in the hydroxyl-containing water-based resin to form a crosslinked network, thereby providing the coating film with better chemical properties. The polyisocyanate composition of the present invention is particularly suitable for water-based two-component polyurethane coatings. The water-based two-component polyurethane coatings prepared with the polyisocyanate composition of the present invention have excellent water resistance, salt spray resistance, adhesion and drying speed, and also have good gloss and hardness.

[0061] As a preferred solution, the water-based coating comprises the following components in parts by weight: 10-20 parts by weight of any of the above-mentioned polyisocyanate compositions and 60 parts by weight of a hydroxyl-containing water-based resin.

[0062] Furthermore, the water-based paint further comprises other additives, and the weight portion of the other additives in the water-based paint is 2-60 parts. By adding other additives, the performance and decorative effect of the water-based paint can be improved. Preferably, the weight portion of the other additives in the water-based paint is 5-40 parts.

[0063] As a preferred solution, the other additives include one or more of a defoamer, a leveling agent, a cosolvent, a color paste or a thickener. The weight portion of the defoamer in the water-based paint is 0.1-1 part; the weight portion of the leveling agent in the water-based paint is 0.1-1 part; the weight portion of the cosolvent in the water-based paint is 1-10 parts; the weight portion of the color paste in the water-based paint is 1-40 parts; the weight portion of the thickener in the water-based paint is 0.1-2 parts. The defoamer eliminates the bubbles generated during the stirring process and the bubbles generated during the reaction process; the leveling agent acts on the interface between the water-based paint liquid and the air to improve the flatness of the paint film surface and prevent defects such as Bénard vortices; the cosolvent improves the film-forming properties of the water-based paint, establishes a volatilization gradient of the water-based paint, and improves the surface effect of the coating; the color paste provides the covering power and color effect required for the coating; the thickener adjusts the rheological properties of the water-based paint to improve the anti-sagging, anti-splashing and other properties of the paint.

[0064] As a preferred solution, the defoamer is at least one of a polysiloxane defoamer and a mineral oil defoamer; the leveling agent is at least one of a polysiloxane leveling agent and an acrylic leveling agent; the cosolvent is at least one of ethylene glycol butyl ether, propylene glycol butyl ether, diethylene glycol butyl ether, dipropylene glycol methyl ether, and dipropylene glycol butyl ether; the color paste is at least one of an inorganic color paste and an organic color paste, and the thickener is at least one of a polyurethane thickener, an alkali swellable acrylic thickener, and bentonite. The above-mentioned defoamer, leveling agent, cosolvent, and thickener do not represent limitations on the present invention, and those skilled in the art may also select other types of defoamers, leveling agents, cosolvents, color pastes, and thickeners according to actual needs.

[0065] The present invention also provides a method for preparing the water-based paint, comprising the following steps: uniformly mixing the components to obtain the water-based paint.

[0066] As another application, the present invention provides a product coated with the water-based coating, which is formed by spraying the water-based coating including the polyisocyanate composition on the surface of a substrate.

[0067] Compared with the prior art, the present invention has the following beneficial effects:

[0068] The polyisocyanate composition of the present invention can be applied to water-based coatings. The coating film formed by the water-based coating has excellent water resistance, salt spray resistance, adhesion and drying speed, and also has good gloss and hardness.

[0069] The inventors of the present invention have repeatedly studied and found that the group structure shown in formula (1a), (1b), and (1c) contains two or three silane groups. Therefore, after the isocyanate group on the aliphatic polyisocyanate is modified into the group shown in formula (1a), (1b), and (1c), two or three silane groups can be introduced, so that the polyisocyanate composition has a higher NCO value and a high density of silane groups. The silane groups will hydrolyze and crosslink after contacting the aqueous phase, accelerating the curing speed. The silane groups will also form bonds with the metal substrate to increase adhesion and water resistance and salt spray resistance. Surprisingly, we found that two or three silane groups in the scheme of the present invention that are close to each other will produce a synergistic effect. Compared with the traditional scheme of introducing only one silane for each isocyanate group modification, even with the same silane content, the technical scheme of the present invention is still significantly more excellent. In order to ensure good compatibility in an aqueous system, the polyisocyanate composition of the present invention increases the compatibility of the polyisocyanate composition in an aqueous system by introducing a sulfonate group and / or a polyethylene glycol monoalkyl ether group. DETAILED DESCRIPTION

[0070] The present invention is further described below in conjunction with examples. These examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. The experimental methods in the following examples that do not specify specific conditions are usually carried out according to conventional conditions in the art or according to the conditions recommended by the manufacturer; the raw materials, reagents, etc. used, unless otherwise specified, are all raw materials and reagents that can be obtained from commercial channels such as conventional markets. Any non-substantial changes and substitutions made by those skilled in the art on the basis of the present invention belong to the scope of protection claimed by the present invention.

[0071] Example 1

[0072] This embodiment provides a polyisocyanate composition A1, comprising:

[0073] (1) Isocyanate group;

[0074] (2) a group represented by formula (1a);

[0075]

[0076] Wherein, X is methylene, Y is ethyl, and R is methyl;

[0077] (3) Sulfonate groups bonded in the form of urea bonds.

[0078] The polyisocyanate composition A1 of this embodiment is prepared by the following process:

[0079] The reaction flask was purged with nitrogen, and 1020.0 g of HDI-based polyisocyanate Wannate HT-100 (Wanhua Chemical, NCO value: 22%) and 51.4 g of trimethylolpropane diallyl ether were added. The temperature was raised to 80°C for reaction for 6 h, and then 0.40 g of Custer catalyst (Pt content 5000 ppm) was added. Then 58.7 g of trimethoxyhydrosilane was added dropwise at 80°C for 1 h, and then the reaction was continued at 80°C for 2 h. 24.0 g of 4-(cyclohexylamino)-1-butanesulfonic acid and 13.0 g of N,N-dimethylcyclohexylamine were added, and then the temperature was raised to 90°C for reaction for 6 h. A light yellow transparent viscous liquid was obtained by filtration, namely, polyisocyanate composition A1.

[0080] During the preparation of the polyisocyanate composition A1 of this embodiment, the isocyanate groups on the polyisocyanate Wannate HT-100 are divided into the following three parts:

[0081] ① A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 undergoes an amination reaction with trimethylolpropane diallyl ether, and the product of the amination reaction undergoes an addition reaction with trimethoxysilane in the presence of a heavy metal catalyst Pt to generate a group shown in formula (1a), wherein X is a methylene group, Y is an ethyl group, and R is a methyl group; the group shown in formula (1a) contains a carbamate group and two Si(OR)3 groups;

[0082] ② A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 reacts with 4-(cyclohexylamino)-1-butanesulfonic acid to generate sulfonate groups bonded in the form of urea bonds; the sulfonate groups bonded in the form of urea bonds contain urea groups and sulfonate groups; in addition, the sulfonic acid groups on the 4-(cyclohexylamino)-1-butanesulfonic acid are neutralized by N,N-dimethylcyclohexylamine and exist in the form of neutralized sulfonate groups;

[0083] ③ Some of the isocyanate groups on the polyisocyanate Wannate HT-100 did not participate in the reaction.

[0084] In the polyisocyanate composition A1 of this embodiment: the NCO value is 17.9%; the molar amount of the Si(OR)3 group in formula (1a) is 9.0% of the total molar amount of the isocyanate group, the carbamate group and the urea group contained in the polyisocyanate composition A1 (i.e. the total molar amount of the NCO group before the reaction); the molar amount of the sulfonate group is 1.9% of the total molar amount of the isocyanate group, the carbamate group and the urea group contained in the polyisocyanate composition A1 (i.e. the total molar amount of the NCO group before the reaction).

[0085] Example 2

[0086] This embodiment provides a polyisocyanate composition A2, comprising:

[0087] (1) Isocyanate group;

[0088] (2) a group represented by formula (1b);

[0089]

[0090] Wherein, X is a methylene group and R is a methyl group;

[0091] (3) Sulfonate groups bonded in the form of urea bonds.

[0092] The polyisocyanate composition A2 of this embodiment is prepared by the following process:

[0093] The reaction flask was purged with nitrogen, and 1020.0 g of HDI-based polyisocyanate Wannate HT-100 (Wanhua Chemical, NCO value: 22%) and 61.5 g of pentaerythritol triallyl ether were added. The temperature was raised to 80°C for reaction for 6 h, and then 0.54 g of Custer catalyst (Pt content 5000 ppm) was added. Then 88.0 g of trimethoxyhydrosilane was added dropwise at 80°C for 1 h, and then the reaction was continued at 80°C for 2 h. 24.0 g of 4-(cyclohexylamino)-1-butanesulfonic acid and 13.0 g of N,N-dimethylcyclohexylamine were added, and the temperature was raised to 90°C for reaction for 6 h. A light yellow transparent viscous liquid was obtained by filtration, namely, polyisocyanate composition A2.

[0094] During the preparation of the polyisocyanate composition A2 of this embodiment, the isocyanate groups on the polyisocyanate Wannate HT-100 are divided into the following three parts:

[0095] ① A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 undergoes an amination reaction with pentaerythritol triallyl ether, and the product of the amination reaction undergoes an addition reaction with trimethoxysilane in the presence of a heavy metal catalyst Pt to generate a group shown in formula (1b), wherein X is a methylene group and R is a methyl group; the group shown in formula (1b) contains a carbamate group and three Si(OR)3 groups;

[0096] ② A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 reacts with 4-(cyclohexylamino)-1-butanesulfonic acid to generate sulfonate groups bonded in the form of urea bonds; the sulfonate groups bonded in the form of urea bonds contain urea groups and sulfonate groups; in addition, the sulfonic acid groups on the 4-(cyclohexylamino)-1-butanesulfonic acid are neutralized by N,N-dimethylcyclohexylamine and exist in the form of neutralized sulfonate groups;

[0097] ③ Some of the isocyanate groups on the polyisocyanate Wannate HT-100 did not participate in the reaction.

[0098] In the polyisocyanate composition A2 of this embodiment: the NCO value is 17.3%; the molar amount of the Si(OR)3 group in formula (1b) is 13.5% of the total molar amount of the isocyanate group, the carbamate group and the urea group contained in the polyisocyanate composition A2 (i.e. the total molar amount of the NCO group before the reaction); and the molar amount of the sulfonate group is 1.9% of the total molar amount of the isocyanate group, the carbamate group and the urea group contained in the polyisocyanate composition A2 (i.e. the total molar amount of the NCO group before the reaction).

[0099] Example 3

[0100] This embodiment provides a polyisocyanate composition A3, comprising:

[0101] (1) Isocyanate group;

[0102] (2) a group represented by formula (1c);

[0103]

[0104] Wherein, R is a methyl group;

[0105] (3) Sulfonate groups bonded in the form of urea bonds.

[0106] The polyisocyanate composition A3 of this embodiment is prepared by the following process:

[0107] The reaction flask was purged with nitrogen, and 1020.0 g of HDI-based polyisocyanate Wannate HT-100 (Wanhua Chemical, NCO value: 22%) and 82.0 g of bis(3-trimethoxysilylpropyl)amine were added, and the temperature was raised to 80°C for reaction for 6 h. 24.0 g of 4-(cyclohexylamino)-1-butanesulfonic acid and 13.0 g of N,N-dimethylcyclohexylamine were added, and the temperature was raised to 90°C for reaction for 6 h. A light yellow transparent viscous liquid was obtained by filtration, namely, polyisocyanate composition A3.

[0108] During the preparation of the polyisocyanate composition A3 of this embodiment, the isocyanate groups on the polyisocyanate Wannate HT-100 are divided into the following three parts:

[0109] ① A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 reacts with bis(3-trimethoxysilylpropyl)amine to generate a group shown in formula (1c), wherein R is a methyl group; the group shown in formula (1c) contains a urea group and two Si(OR)3 groups;

[0110] ② A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 reacts with 4-(cyclohexylamino)-1-butanesulfonic acid to generate sulfonate groups bonded in the form of urea bonds; the sulfonate groups bonded in the form of urea bonds contain urea groups and sulfonate groups; in addition, the sulfonic acid groups on the 4-(cyclohexylamino)-1-butanesulfonic acid are neutralized by N,N-dimethylcyclohexylamine and exist in the form of neutralized sulfonate groups;

[0111] ③ Some of the isocyanate groups on the polyisocyanate Wannate HT-100 did not participate in the reaction.

[0112] In the polyisocyanate composition A3 of this embodiment: the NCO value is 18.3%; the molar amount of the Si(OR)3 group in formula (1c) is 9.0% of the total molar amount of the isocyanate group, the carbamate group (the content is 0), and the urea group contained in the polyisocyanate composition A3 (i.e., the total molar amount of the NCO group before the reaction); and the molar amount of the sulfonate group is 1.9% of the total molar amount of the isocyanate group, the carbamate group (the content is 0), and the urea group contained in the polyisocyanate composition (i.e., the total molar amount of the NCO group before the reaction).

[0113] Example 4

[0114] This embodiment provides a polyisocyanate composition A4, comprising:

[0115] (1) Isocyanate group;

[0116] (2) a group represented by formula (1a);

[0117]

[0118] Wherein, X is methylene, Y is ethyl, and R is methyl;

[0119] (3) Polyethylene glycol monoalkyl ether groups bonded in the form of urethane bonds.

[0120] The polyisocyanate composition A4 of this embodiment is prepared by the following process:

[0121] The reaction flask was purged with nitrogen, and 1020.0 g of HDI-based polyisocyanate Wannate HT-100 (Wanhua Chemical, NCO value: 22%) and 51.4 g of trimethylolpropane diallyl ether were added. The temperature was raised to 80°C for reaction for 6 h, and then 0.40 g of Custer catalyst (Pt content 5000 ppm) was added. Then 58.7 g of trimethoxyhydrosilane was added dropwise at 80°C for 1 h, and then the reaction was continued at 80°C for 2 h. 51.0 g of polyethylene glycol monomethyl ether (molecular weight 500) was added, and the temperature was raised to 90°C for reaction for 8 h. A light yellow transparent viscous liquid was obtained by filtration, namely, polyisocyanate composition A4.

[0122] The structural formula of polyethylene glycol monomethyl ether used in this embodiment is shown in formula (2).

[0123]

[0124] Among them, Z is a methyl group, and the average value of n is 10.6.

[0125] During the preparation of the polyisocyanate composition A4 of this embodiment, the isocyanate groups on the polyisocyanate Wannate HT-100 are divided into the following three parts:

[0126] ① A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 undergoes an amination reaction with trimethylolpropane diallyl ether, and the product of the amination reaction undergoes an addition reaction with trimethoxysilane in the presence of a heavy metal catalyst Pt to generate a group shown in formula (1a), wherein X is a methylene group, Y is an ethyl group, and R is a methyl group; the group shown in formula (1a) contains a carbamate group and two Si(OR)3 groups;

[0127] ② A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 reacts with polyethylene glycol monomethyl ether to generate polyethylene glycol monoalkyl ether groups bonded in the form of carbamate bonds; the polyethylene glycol monoalkyl ether groups bonded in the form of carbamate bonds contain carbamate groups and polyethylene glycol monoalkyl ether groups;

[0128] ③ Some of the isocyanate groups on the polyisocyanate Wannate HT-100 did not participate in the reaction.

[0129] In the polyisocyanate composition A4 of this embodiment: the NCO value is 17.7%; the molar amount of the Si(OR)3 group in formula (1a) is 9.0% of the total molar amount of the isocyanate group, the carbamate group and the urea group contained in the polyisocyanate composition A4 (i.e., the total molar amount of the NCO group before the reaction); and the molar amount of the polyethylene glycol monoalkyl ether group is 1.9% of the total molar amount of the isocyanate group, the carbamate group and the urea group contained in the polyisocyanate composition A4 (i.e., the total molar amount of the NCO group before the reaction).

[0130] Example 5

[0131] This embodiment provides a polyisocyanate composition A5, comprising:

[0132] (1) Isocyanate group;

[0133] (2) a group represented by formula (1a);

[0134]

[0135] Wherein, X is methylene, Y is ethyl, and R is methyl;

[0136] (3) Sulfonate groups bonded in the form of urea bonds.

[0137] The polyisocyanate composition A5 of this embodiment is prepared by the following process:

[0138] The reaction flask was purged with nitrogen, and 1020.0 g of HDI-based polyisocyanate Wannate HT-100 (Wanhua Chemical, NCO value: 22%) and 12.9 g of trimethylolpropane diallyl ether were added. The temperature was raised to 80°C for reaction for 6 h, and then 0.10 g of Custer catalyst (Pt content 5000 ppm) was added. Then 14.7 g of trimethoxyhydrosilane was added dropwise at 80°C for 1 h, and then the reaction was continued at 80°C for 2 h. 24.0 g of 4-(cyclohexylamino)-1-butanesulfonic acid and 13.0 g of N,N-dimethylcyclohexylamine were added, and the temperature was raised to 90°C for reaction for 6 h. A light yellow transparent viscous liquid was obtained by filtration, namely, polyisocyanate composition A5.

[0139] During the preparation of the polyisocyanate composition A5 of this embodiment, the isocyanate groups on the polyisocyanate Wannate HT-100 are divided into the following three parts:

[0140] ① A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 undergoes an amination reaction with trimethylolpropane diallyl ether, and the product of the amination reaction undergoes an addition reaction with trimethoxysilane in the presence of a heavy metal catalyst Pt to generate a group shown in formula (1a), wherein X is a methylene group, Y is an ethyl group, and R is a methyl group; the group shown in formula (1a) contains a carbamate group and two Si(OR)3 groups;

[0141] ② A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 reacts with 4-(cyclohexylamino)-1-butanesulfonic acid to generate sulfonate groups bonded in the form of urea bonds; the sulfonate groups bonded in the form of urea bonds contain urea groups and sulfonate groups; in addition, the sulfonic acid groups on the 4-(cyclohexylamino)-1-butanesulfonic acid are neutralized by N,N-dimethylcyclohexylamine and exist in the form of neutralized sulfonate groups;

[0142] ③ Some of the isocyanate groups on the polyisocyanate Wannate HT-100 did not participate in the reaction.

[0143] In the polyisocyanate composition A5 of this embodiment: the NCO value is 20.0%; the molar amount of the Si(OR)3 group in formula (1a) is 2.2% of the total molar amount of the isocyanate group, the carbamate group and the urea group contained in the polyisocyanate composition A5 (i.e. the total molar amount of the NCO group before the reaction); and the molar amount of the sulfonate group is 1.9% of the total molar amount of the isocyanate group, the carbamate group and the urea group contained in the polyisocyanate composition A5 (i.e. the total molar amount of the NCO group before the reaction).

[0144] Example 6

[0145] This embodiment provides a polyisocyanate composition A6, comprising:

[0146] (1) Isocyanate group;

[0147] (2) a group represented by formula (1a);

[0148]

[0149] Wherein, X is methylene, Y is ethyl, and R is methyl;

[0150] (3) Sulfonate groups bonded in the form of urea bonds.

[0151] The polyisocyanate composition A6 of this embodiment is prepared by the following process:

[0152] The reaction flask was purged with nitrogen, and 1020.0 g of HDI-based polyisocyanate Wannate HT-100 (Wanhua Chemical, NCO value: 22%) and 171.4 g of trimethylolpropane diallyl ether were added. The temperature was raised to 80°C for reaction for 6 h, and then 1.33 g of Custer catalyst (Pt content 5000 ppm) was added. Then 195.5 g of trimethoxyhydrosilane was added dropwise at 80°C for 1 h, and then the reaction was continued at 80°C for 2 h. 24.0 g of 4-(cyclohexylamino)-1-butanesulfonic acid and 13.0 g of N,N-dimethylcyclohexylamine were added, and then the temperature was raised to 90°C for reaction for 6 h. A light yellow transparent viscous liquid was obtained by filtration, namely, polyisocyanate composition A6.

[0153] During the preparation of the polyisocyanate composition A6 of this embodiment, the isocyanate groups on the polyisocyanate Wannate HT-100 are divided into the following three parts:

[0154] ① A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 undergoes an amination reaction with trimethylolpropane diallyl ether, and the product of the amination reaction undergoes an addition reaction with trimethoxysilane in the presence of a heavy metal catalyst Pt to generate a group shown in formula (1a), wherein X is a methylene group, Y is an ethyl group, and R is a methyl group; the group shown in formula (1a) contains a carbamate group and two Si(OR)3 groups;

[0155] ② A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 reacts with 4-(cyclohexylamino)-1-butanesulfonic acid to generate sulfonate groups bonded in the form of urea bonds; the sulfonate groups bonded in the form of urea bonds contain urea groups and sulfonate groups; in addition, the sulfonic acid groups on the 4-(cyclohexylamino)-1-butanesulfonic acid are neutralized by N,N-dimethylcyclohexylamine and exist in the form of neutralized sulfonate groups;

[0156] ③ Some of the isocyanate groups on the polyisocyanate Wannate HT-100 did not participate in the reaction.

[0157] In the polyisocyanate composition A6 of this embodiment: the NCO value is 13.0%; the molar amount of the Si(OR)3 group in formula (1a) is 29.9% of the total molar amount of the isocyanate groups, carbamate groups and urea groups contained in the polyisocyanate composition A6 (i.e. the total molar amount of the NCO groups before the reaction); the molar amount of the sulfonate group in A6 is 1.9% of the total molar amount of the isocyanate groups, carbamate groups and urea groups contained in the polyisocyanate composition A6 (i.e. the total molar amount of the NCO groups before the reaction).

[0158] Example 7

[0159] This embodiment provides a polyisocyanate composition A7, comprising:

[0160] (1) Isocyanate group;

[0161] (2) a group represented by formula (1a);

[0162]

[0163] Wherein, X is methylene, Y is ethyl, and R is methyl;

[0164] (3) Sulfonate groups bonded in the form of urea bonds.

[0165] The polyisocyanate composition A7 of this embodiment is prepared by the following process:

[0166] The reaction flask was purged with nitrogen, and 1020.0 g of HDI-based polyisocyanate Wannate HT-100 (Wanhua Chemical, NCO value: 22%) and 51.4 g of trimethylolpropane diallyl ether were added. The temperature was raised to 80°C for reaction for 6 h, and then 0.40 g of Custer catalyst (Pt content 5000 ppm) was added. Then 58.7 g of trimethoxyhydrosilane was added dropwise at 80°C for 1 h, and then the reaction was continued at 80°C for 2 h. 9.0 g of 4-(cyclohexylamino)-1-butanesulfonic acid and 4.9 g of N,N-dimethylcyclohexylamine were added, and then the temperature was raised to 90°C for reaction for 6 h. A light yellow transparent viscous liquid was obtained by filtration, namely, polyisocyanate composition A7.

[0167] During the preparation of the polyisocyanate composition A7 of this embodiment, the isocyanate groups on the polyisocyanate Wannate HT-100 are divided into the following three parts:

[0168] ① A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 undergoes an amination reaction with trimethylolpropane diallyl ether, and the product of the amination reaction undergoes an addition reaction with trimethoxysilane in the presence of a heavy metal catalyst Pt to generate a group shown in formula (1a), wherein X is a methylene group, Y is an ethyl group, and R is a methyl group; the group shown in formula (1a) contains a carbamate group and two Si(OR)3 groups;

[0169] ② A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 reacts with 4-(cyclohexylamino)-1-butanesulfonic acid to generate sulfonate groups bonded in the form of urea bonds; the sulfonate groups bonded in the form of urea bonds contain urea groups and sulfonate groups; in addition, the sulfonic acid groups on the 4-(cyclohexylamino)-1-butanesulfonic acid are neutralized by N,N-dimethylcyclohexylamine and exist in the form of neutralized sulfonate groups;

[0170] ③ Some of the isocyanate groups on the polyisocyanate Wannate HT-100 did not participate in the reaction.

[0171] In the polyisocyanate composition A7 of this embodiment: the NCO value is 18.5%; the molar amount of the Si(OR)3 group in formula (1a) is 9.0% of the total molar amount of the isocyanate group, the carbamate group, and the urea group contained in the polyisocyanate composition A7 (i.e., the total molar amount of the NCO group before the reaction); and the molar amount of the sulfonate group is 0.72% of the total molar amount of the isocyanate group, the carbamate group, and the urea group contained in the polyisocyanate composition A7 (i.e., the total molar amount of the NCO group before the reaction).

[0172] Example 8

[0173] This embodiment provides a polyisocyanate composition A8, comprising:

[0174] (1) Isocyanate group;

[0175] (2) a group represented by formula (1a);

[0176]

[0177] Wherein, X is methylene, Y is ethyl, and R is methyl;

[0178] (3) Sulfonate groups bonded in the form of urea bonds.

[0179] The polyisocyanate composition A8 of this embodiment is prepared by the following process:

[0180] The reaction flask was purged with nitrogen, and 1020.0 g of HDI-based polyisocyanate Wannate HT-100 (Wanhua Chemical, NCO value: 22%) and 51.4 g of trimethylolpropane diallyl ether were added. The temperature was raised to 80°C for reaction for 6 h, and then 0.40 g of Custer catalyst (Pt content 5000 ppm) was added. Then 58.7 g of trimethoxyhydrosilane was added dropwise at 80°C for 1 h, and then the reaction was continued at 80°C for 2 h. 87.0 g of 4-(cyclohexylamino)-1-butanesulfonic acid and 47.0 g of N,N-dimethylcyclohexylamine were added, and the temperature was raised to 90°C for reaction for 6 h. A light yellow transparent viscous liquid was obtained by filtration, namely, polyisocyanate composition A8.

[0181] During the preparation of the polyisocyanate composition A8 of this embodiment, the isocyanate groups on the polyisocyanate Wannate HT-100 are divided into the following three parts:

[0182] ① A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 undergoes an amination reaction with trimethylolpropane diallyl ether, and the product of the amination reaction undergoes an addition reaction with trimethoxysilane in the presence of a heavy metal catalyst Pt to generate a group shown in formula (1a), wherein X is a methylene group, Y is an ethyl group, and R is a methyl group; the group shown in formula (1a) contains a carbamate group and two Si(OR)3 groups;

[0183] ② A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 reacts with 4-(cyclohexylamino)-1-butanesulfonic acid to generate sulfonate groups bonded in the form of urea bonds; the sulfonate groups bonded in the form of urea bonds contain urea groups and sulfonate groups; in addition, the sulfonic acid groups on the 4-(cyclohexylamino)-1-butanesulfonic acid are neutralized by N,N-dimethylcyclohexylamine and exist in the form of neutralized sulfonate groups;

[0184] ③ Some of the isocyanate groups on the polyisocyanate Wannate HT-100 did not participate in the reaction.

[0185] In the polyisocyanate composition A8 of this embodiment: the NCO value is 15.6%; the molar amount of the Si(OR)3 group in formula (1a) is 9.0% of the total molar amount of the isocyanate group, the carbamate group and the urea group contained in the polyisocyanate composition A8 (i.e., the total molar amount of the NCO group before the reaction); and the molar amount of the sulfonate group is 6.9% of the total molar amount of the isocyanate group, the carbamate group and the urea group contained in the polyisocyanate composition A8 (i.e., the total molar amount of the NCO group before the reaction).

[0186] Example 9

[0187] This embodiment provides a polyisocyanate composition A9, comprising:

[0188] (1) Isocyanate group;

[0189] (2) a group represented by formula (1a);

[0190]

[0191] Wherein, X is methylene, Y is ethyl, and R is methyl;

[0192] (3) Polyethylene glycol monoalkyl ether groups bonded in the form of urethane bonds.

[0193] The polyisocyanate composition A9 of this embodiment is prepared by the following process:

[0194] The reaction flask was vented with nitrogen, and 1020.0 g of HDI-based polyisocyanate Wannate HT-100 (Wanhua Chemical, NCO value: 22%) and 51.4 g of trimethylolpropane diallyl ether were added. The temperature was raised to 80°C for reaction for 6 h, and then 0.40 g of Custer catalyst (Pt content 5000 ppm) was added. Then 58.7 g of trimethoxyhydrosilane was added dropwise at 80°C for 1 h, and then the reaction was continued at 80°C for 2 h. 29.9 g of polyethylene glycol monobutyl ether (molecular weight 750) was added, and then the temperature was raised to 90°C for reaction for 8 h. A light yellow transparent viscous liquid was obtained by filtration, i.e., polyisocyanate composition A9, with an NCO value of 18.2%.

[0195] The structural formula of polyethylene glycol monomethyl ether used in this embodiment is shown in formula (2).

[0196]

[0197] Among them, Z is a methyl group, and the average value of n is 16.3.

[0198] During the preparation of the polyisocyanate composition A9 of this embodiment, the isocyanate groups on the polyisocyanate Wannate HT-100 are divided into the following three parts:

[0199] ① A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 undergoes an amination reaction with trimethylolpropane diallyl ether, and the product of the amination reaction undergoes an addition reaction with trimethoxysilane in the presence of a heavy metal catalyst Pt to generate a group shown in formula (1a), wherein X is a methylene group, Y is an ethyl group, and R is a methyl group; the group shown in formula (1a) contains a carbamate group and two Si(OR)3 groups;

[0200] ② A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 reacts with polyethylene glycol monomethyl ether to generate polyethylene glycol monoalkyl ether groups bonded in the form of carbamate bonds; the polyethylene glycol monoalkyl ether groups bonded in the form of carbamate bonds contain carbamate groups and polyethylene glycol monoalkyl ether groups;

[0201] ③ Some of the isocyanate groups on the polyisocyanate Wannate HT-100 did not participate in the reaction.

[0202] In the polyisocyanate composition A9 of this embodiment: the NCO value is 18.2%; the molar amount of the Si(OR)3 group in formula (1a) is 9.0% of the total molar amount of the isocyanate group, the carbamate group and the urea group contained in the polyisocyanate composition A9 (i.e., the total molar amount of the NCO group before the reaction); and the molar amount of the polyethylene glycol monoalkyl ether group is 0.74% of the total molar amount of the isocyanate group, the carbamate group and the urea group contained in the polyisocyanate composition A9 (i.e., the total molar amount of the NCO group before the reaction).

[0203] Example 10

[0204] This embodiment provides a polyisocyanate composition A10, comprising:

[0205] (1) Isocyanate group;

[0206] (2) a group represented by formula (1a);

[0207]

[0208] Wherein, X is methylene, Y is ethyl, and R is methyl;

[0209] (3) Polyethylene glycol monoalkyl ether groups bonded in the form of urethane bonds.

[0210] The polyisocyanate composition A10 of this embodiment is prepared by the following process:

[0211] The reaction flask was vented with nitrogen, and 1020.0 g of HDI-based polyisocyanate Wannate HT-100 (Wanhua Chemical, NCO value: 22%) and 51.4 g of trimethylolpropane diallyl ether were added. The temperature was raised to 80°C for reaction for 6 h, and then 0.40 g of Custer catalyst (Pt content 5000 ppm) was added. Then 58.7 g of trimethoxyhydrosilane was added dropwise at 80°C for 1 h, and then the reaction was continued at 80°C for 2 h. 129.5 g of polyethylene glycol monobutyl ether (molecular weight 350) was added, and the temperature was raised to 90°C for reaction for 8 h. A light yellow transparent viscous liquid was obtained by filtration, namely, polyisocyanate composition A10.

[0212] The structural formula of polyethylene glycol monomethyl ether used in this embodiment is shown in formula (2).

[0213]

[0214] Among them, Z is a butyl group, and the average value of n is 6.3.

[0215] During the preparation of the polyisocyanate composition A10 of this embodiment, the isocyanate groups on the polyisocyanate Wannate HT-100 are divided into the following three parts:

[0216] ① A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 undergoes an amination reaction with trimethylolpropane diallyl ether, and the product of the amination reaction undergoes an addition reaction with trimethoxysilane in the presence of a heavy metal catalyst Pt to generate a group shown in formula (1a), wherein X is a methylene group, Y is an ethyl group, and R is a methyl group; the group shown in formula (1a) contains a carbamate group and two Si(OR)3 groups;

[0217] ② A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 reacts with polyethylene glycol monomethyl ether to generate polyethylene glycol monoalkyl ether groups bonded in the form of carbamate bonds; the polyethylene glycol monoalkyl ether groups bonded in the form of carbamate bonds contain carbamate groups and polyethylene glycol monoalkyl ether groups;

[0218] ③ Some of the isocyanate groups on the polyisocyanate Wannate HT-100 did not participate in the reaction.

[0219] In the polyisocyanate composition A10 of this embodiment: the NCO value is 15.7%; the molar amount of the Si(OR)3 group in formula (1a) is 9.0% of the total molar amount of the isocyanate group, the carbamate group and the urea group contained in the polyisocyanate composition A10 (i.e., the total molar amount of the NCO group before the reaction); and the molar amount of the polyethylene glycol monoalkyl ether group is 6.9% of the total molar amount of the isocyanate group, the carbamate group and the urea group contained in the polyisocyanate composition A10 (i.e., the total molar amount of the NCO group before the reaction).

[0220] Embodiment 11

[0221] This embodiment provides a polyisocyanate composition A11,

[0222] (1) Isocyanate group;

[0223] (2) a group represented by formula (1a);

[0224]

[0225] Wherein, X is methylene, Y is ethyl, and R is ethyl;

[0226] (3) Sulfonate groups bonded in the form of urea bonds.

[0227] The polyisocyanate composition A11 of this embodiment is prepared by the following process:

[0228] The reaction flask was purged with nitrogen, and 620.0 g of HDI-based polyisocyanate Wannate HT-100 (Wanhua Chemical, NCO value: 22%), 400.0 g of IPDI-based polyisocyanate Wannate IT-100 (Wanhua Chemical, NCO value: 17.4%), 501.1 g of propylene glycol diacetate, and 51.4 g of trimethylolpropane diallyl ether were added, and the temperature was raised to 80°C for reaction for 6 h, and then 0.40 g of Custer catalyst (Pt content 5000 ppm) was added, and then 78.8 g of triethoxyhydrosilane was added dropwise at 80°C for 1 h, and then the reaction was continued at 80°C for 2 h. 24.0 g of 2-(cyclohexylamino)-1-ethanesulfonic acid and 14.7 g of N,N-dimethylcyclohexylamine were added, and then the temperature was raised to 90°C for reaction for 6 h. The light yellow transparent viscous liquid was obtained by filtration, namely the polyisocyanate composition A11.

[0229] In the preparation process of the polyisocyanate composition A11 of this embodiment, propylene glycol diacetate is used as a solvent to reduce the viscosity; the total isocyanate groups on the polyisocyanate Wannate HT-100 and the polyisocyanate Wannate IT-100 are divided into the following three parts:

[0230] ① A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 and / or the polyisocyanate Wannate IT-100 undergo an amination reaction with trimethylolpropane diallyl ether, and the product of the amination reaction undergoes an addition reaction with triethoxyhydrosilane in the presence of a heavy metal catalyst Pt to generate a group shown in formula (1a), wherein X is a methylene group, Y is an ethyl group, and R is an ethyl group; the group shown in formula (1a) contains a carbamate group and two Si(OR)3 groups;

[0231] ② A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 and / or the polyisocyanate Wannate IT-100 react with 2-(cyclohexylamino)-1-ethanesulfonic acid to generate sulfonate groups bonded in the form of urea bonds; the sulfonate groups bonded in the form of urea bonds contain urea groups and sulfonate groups; in addition, the sulfonic acid groups on the 2-(cyclohexylamino)-1-ethanesulfonic acid are neutralized by N,N-dimethylcyclohexylamine and exist in the form of neutralized sulfonate groups;

[0232] ③ A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 and / or the polyisocyanate Wannate IT-100 do not participate in the reaction.

[0233] In the polyisocyanate composition A11 of this embodiment: the NCO value is 11.3%; the molar amount of the Si(OR)3 group in formula (1a) is 9.8% of the total molar amount of the isocyanate groups, carbamate groups and urea groups contained in the polyisocyanate composition A11 (i.e. the total molar amount of the NCO groups before the reaction); and the molar amount of the sulfonate group is 2.4% of the total molar amount of the isocyanate groups, carbamate groups and urea groups contained in the polyisocyanate composition A11 (i.e. the total molar amount of the NCO groups before the reaction).

[0234] Comparative Example 1

[0235] This comparative example provides a polyisocyanate composition B1, which is prepared by the following process:

[0236] The reaction flask was vented with nitrogen, and 1020.0 g of HDI-based polyisocyanate Wannate HT-100 (Wanhua Chemical, NCO value: 22%) and 49.0 g of ethylene glycol monoallyl ether were added. The temperature was raised to 80°C for reaction for 6 h, and then 0.40 g of Custer catalyst (Pt content 5000 ppm) was added. Then 58.7 g of trimethoxyhydrosilane was added dropwise at 80°C for 1 h, and then the reaction was continued at 80°C for 2 h. 24.0 g of 4-(cyclohexylamino)-1-butanesulfonic acid and 13.0 g of N,N-dimethylcyclohexylamine were added, and the temperature was raised to 90°C for reaction for 6 h. A light yellow transparent viscous liquid was obtained by filtration, namely, polyisocyanate composition B1.

[0237] During the preparation of the polyisocyanate composition B1 of this comparative example, the isocyanate groups on the polyisocyanate Wannate HT-100 are divided into the following three parts:

[0238] ① A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 undergo an amination reaction with ethylene glycol monoallyl ether, and the product of the amination reaction then undergoes an addition reaction with trimethoxysilane in the presence of a heavy metal catalyst Pt; the product of the addition reaction contains a carbamate group and a Si(OR)3 group;

[0239] ② A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 reacts with 4-(cyclohexylamino)-1-butanesulfonic acid to generate sulfonate groups bonded in the form of urea bonds; the sulfonate groups bonded in the form of urea bonds contain urea groups and sulfonate groups; in addition, the sulfonic acid groups on the 4-(cyclohexylamino)-1-butanesulfonic acid are neutralized by N,N-dimethylcyclohexylamine and exist in the form of neutralized sulfonate groups;

[0240] ③ Some of the isocyanate groups on the polyisocyanate Wannate HT-100 did not participate in the reaction.

[0241] In the polyisocyanate composition B1 of this comparative example, the NCO value is 17.1%. The polyisocyanate composition B1 does not contain structures of formula (1a), (1b) and (1c). The molar amount of Si(OR)3 groups is 9.0% of the total molar amount of isocyanate groups, carbamate groups and urea groups contained in the polyisocyanate composition B1 (i.e. the total molar amount of NCO groups before the reaction). The molar amount of sulfonate groups is 1.9% of the total molar amount of isocyanate groups, carbamate groups and urea groups contained in the polyisocyanate composition B1 (i.e. the total molar amount of NCO groups before the reaction).

[0242] Comparative Example 2

[0243] This comparative example provides a polyisocyanate composition B2, which is prepared by the following process:

[0244] The reaction flask was purged with nitrogen, and 1020.0 g of HDI-based polyisocyanate Wannate HT-100 (Wanhua Chemical, NCO value: 22%) and 168.7 g of silane-functionalized aspartic acid (synthesized according to Example 1 of patent CN1637106A, obtained by the reaction of diethyl maleate and γ-aminopropyltrimethoxysilane) were added, and the temperature was raised to 80°C for 6 h. 24.0 g of 4-(cyclohexylamino)-1-butanesulfonic acid and 13.0 g of N,N-dimethylcyclohexylamine were added, and the temperature was raised to 90°C for 6 h. A light yellow transparent viscous liquid was obtained by filtration, namely, polyisocyanate composition B2.

[0245] During the preparation of the polyisocyanate composition B2 of this comparative example, the isocyanate groups on the polyisocyanate Wannate HT-100 are divided into the following three parts:

[0246] ① A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 react with silane-functionalized aspartic acid, and the product of the reaction contains a urea group and a Si(OR)3 group;

[0247] ② A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 reacts with 4-(cyclohexylamino)-1-butanesulfonic acid to generate sulfonate groups bonded in the form of urea bonds; the sulfonate groups bonded in the form of urea bonds contain urea groups and sulfonate groups; in addition, the sulfonic acid groups on the 4-(cyclohexylamino)-1-butanesulfonic acid are neutralized by N,N-dimethylcyclohexylamine and exist in the form of neutralized sulfonate groups;

[0248] ③ Some of the isocyanate groups on the polyisocyanate Wannate HT-100 did not participate in the reaction.

[0249] In the polyisocyanate composition B2 of this comparative example: the NCO value is 16.2%; the polyisocyanate composition B2 does not contain the structures of formula (1a), (1b) and (1c); the molar amount of Si(OR)3 groups is 9.0% of the total molar amount of isocyanate groups, carbamate groups and urea groups contained in the polyisocyanate composition B2 (i.e. the total molar amount of NCO groups before the reaction); and the molar amount of sulfonate groups is 1.9% of the total molar amount of isocyanate groups, carbamate groups and urea groups contained in the polyisocyanate composition B2 (i.e. the total molar amount of NCO groups before the reaction).

[0250] Comparative Example 3

[0251] This comparative example provides a polyisocyanate composition B3, comprising:

[0252] (1) Isocyanate group;

[0253] (2) a group represented by formula (1a);

[0254]

[0255] Wherein, X is methylene, Y is ethyl, and R is methyl;

[0256] (3) Sulfonate groups bonded in the form of urea bonds.

[0257] The polyisocyanate composition B3 of this comparative example is prepared by the following process:

[0258] The reaction flask was purged with nitrogen, and 1020.0 g of HDI-based polyisocyanate Wannate HT-100 (Wanhua Chemical, NCO value: 22%) and 6.4 g of trimethylolpropane diallyl ether were added. The temperature was raised to 80°C for reaction for 6 h, and then 0.05 g of Custer catalyst (Pt content 5000 ppm) was added. Then 7.3 g of trimethoxyhydrosilane was added dropwise at 80°C for 1 h, and then the reaction was continued at 80°C for 2 h. 24.0 g of 4-(cyclohexylamino)-1-butanesulfonic acid and 13.0 g of N,N-dimethylcyclohexylamine were added, and then the temperature was raised to 90°C for reaction for 6 h. A light yellow transparent viscous liquid was obtained by filtration, namely, polyisocyanate composition B3.

[0259] During the preparation of the polyisocyanate composition B3 of this comparative example, the isocyanate groups on the polyisocyanate Wannate HT-100 are divided into the following three parts:

[0260] ① A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 undergoes an amination reaction with trimethylolpropane diallyl ether, and the product of the amination reaction undergoes an addition reaction with trimethoxysilane in the presence of a heavy metal catalyst Pt to generate a group shown in formula (1a), wherein X is a methylene group, Y is an ethyl group, and R is a methyl group; the group shown in formula (1a) contains a carbamate group and two Si(OR)3 groups;

[0261] ② A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 reacts with 4-(cyclohexylamino)-1-butanesulfonic acid to generate sulfonate groups bonded in the form of urea bonds; the sulfonate groups bonded in the form of urea bonds contain urea groups and sulfonate groups; in addition, the sulfonic acid groups on the 4-(cyclohexylamino)-1-butanesulfonic acid are neutralized by N,N-dimethylcyclohexylamine and exist in the form of neutralized sulfonate groups;

[0262] ③ Some of the isocyanate groups on the polyisocyanate Wannate HT-100 did not participate in the reaction.

[0263] In the polyisocyanate composition B3 of this comparative example: the NCO value is 20.4%; the molar amount of the Si(OR)3 group in formula (1a) is 1.1% of the total molar amount of the isocyanate group, carbamate group, and urea group contained in the polyisocyanate composition B3 (i.e., the total molar amount of the NCO group before the reaction). The molar amount of the sulfonate group is 1.9% of the total molar amount of the isocyanate group, carbamate group, and urea group contained in the polyisocyanate composition B3 (i.e., the total molar amount of the NCO group before the reaction).

[0264] Comparative Example 4

[0265] This comparative example provides a polyisocyanate composition B4, comprising:

[0266] (1) Isocyanate group;

[0267] (2) a group represented by formula (1a);

[0268]

[0269] Wherein, X is methylene, Y is ethyl, and R is methyl;

[0270] (3) Sulfonate groups bonded in the form of urea bonds.

[0271] The polyisocyanate composition B4 of this comparative example is prepared by the following process:

[0272] The reaction flask was purged with nitrogen, and 1020.0 g of HDI-based polyisocyanate Wannate HT-100 (Wanhua Chemical, NCO value: 22%) and 214.3 g of trimethylolpropane diallyl ether were added. The temperature was raised to 80°C for reaction for 6 h, and then 1.67 g of Custer catalyst (Pt content 5000 ppm) was added. Then 244.4 g of trimethoxyhydrosilane was added dropwise at 80°C for 1 h, and then the reaction was continued at 80°C for 2 h. 24.0 g of 4-(cyclohexylamino)-1-butanesulfonic acid and 13.0 g of N,N-dimethylcyclohexylamine were added, and then the temperature was raised to 90°C for reaction for 6 h. A light yellow transparent viscous liquid was obtained by filtration, namely, polyisocyanate composition B4.

[0273] During the preparation of the polyisocyanate composition B4 of this comparative example, the isocyanate groups on the polyisocyanate Wannate HT-100 are divided into the following three parts:

[0274] ① A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 undergoes an amination reaction with trimethylolpropane diallyl ether, and the product of the amination reaction undergoes an addition reaction with trimethoxysilane in the presence of a heavy metal catalyst Pt to generate a group shown in formula (1a), wherein X is a methylene group, Y is an ethyl group, and R is a methyl group; the group shown in formula (1a) contains a carbamate group and two Si(OR)3 groups;

[0275] ② A portion of the isocyanate groups on the polyisocyanate Wannate HT-100 reacts with 4-(cyclohexylamino)-1-butanesulfonic acid to generate sulfonate groups bonded in the form of urea bonds; the sulfonate groups bonded in the form of urea bonds contain urea groups and sulfonate groups; in addition, the sulfonic acid groups on the 4-(cyclohexylamino)-1-butanesulfonic acid are neutralized by N,N-dimethylcyclohexylamine and exist in the form of neutralized sulfonate groups;

[0276] ③ Some of the isocyanate groups on the polyisocyanate Wannate HT-100 did not participate in the reaction.

[0277] This comparative example provides a polyisocyanate composition B4 in which the NCO value is 11.7%; the molar amount of the Si(OR)3 group in formula (1a) is 37.4% of the total molar amount of the isocyanate groups, carbamate groups and urea groups contained in the polyisocyanate composition B4 (i.e., the total molar amount of the NCO groups before the reaction); and the molar amount of the sulfonate group is 1.9% of the total molar amount of the isocyanate groups, carbamate groups and urea groups contained in the polyisocyanate composition B4 (i.e., the total molar amount of the NCO groups before the reaction).

[0278] Performance Testing

[0279] The properties of the polyisocyanate compositions A1-A11 of Examples 1-11 and the polyisocyanate compositions B1-B4 of Comparative Examples 1-4 were tested respectively. The process is as follows:

[0280] The polyisocyanate compositions A1-A11 of Examples 1-11, the polyisocyanate compositions B1-B4 of Comparative Examples 1-4, and the commercial water-dispersible polyisocyanate crosslinker OS-9018 (Guangzhou Guanzhi New Materials, solid content: 100%, NCO value: 20.1%) were respectively mixed with a commercial water-based hydroxylated acrylic secondary dispersion (trade name PA-3225, Guangzhou Guanzhi New Materials, solid content: 45%, solid hydroxyl content: 2.2%) to prepare water-based coatings 1-16 according to the formula in Table 1.

[0281] Table 1 Water-based coating formula

[0282]

[0283] The following performance tests were conducted on water-based coatings 1-16:

[0284] Water resistance test: dilute the newly prepared water-based paint with water to a suitable viscosity, spray it on the polished carbon steel substrate, with a film thickness of 23±3μm, bake it at 70℃ for 2h, then leave it at room temperature overnight, soak the carbon steel plate in 40℃ water, and observe whether there is blistering or gloss loss.

[0285] Salt spray resistance test: On carbon steel substrate, the test is carried out according to GB / T1771-2007.

[0286] Gloss test: On carbon steel substrate, the test was conducted in accordance with GB / T 9754-2007.

[0287] Pencil hardness test: On glass substrate, test according to GB / T6739-1996.

[0288] Adhesion test: On carbon steel substrate, test according to GB 9286-98, rating 0-5, 0 is the best.

[0289] Drying speed: On carbon steel substrate, spray dry film thickness is 23±3μm, and observe the time of dry to touch at 25℃.

[0290] The test results are shown in the following table:

[0291] Table 2 Test results of water-based coatings

[0292]

[0293] The water-based coating formulas in Table 1 and the performance test results in Table 2 show that the water-based coatings 1-11 added with the polyisocyanate compositions A1-A11 of Examples 1-11 of the present invention have better water resistance, salt spray resistance, adhesion and drying speed, and have comparable gloss and hardness, compared with the water-based coatings 12-15 added with the polyisocyanate compositions B1-B4 of Comparative Examples 1-4 and the water-based coating 16 added with the conventional commercial water-dispersible isocyanate crosslinking agent OS-9018. This is because the formulas (1a) and (1b) in the polyisocyanate compositions A1-A11 are Two or three silane groups with a relatively close distance are introduced into the group structure shown in formula (1a), (1b) and (1c), that is, after the isocyanate group on the aliphatic polyisocyanate is modified into the group shown in formula (1a), (1b) and (1c), two or three silane groups can be introduced. The polyisocyanate compositions A1-A11 have a high NCO value and a high density of silane groups. The silane groups will hydrolyze and cross-link after contacting the aqueous phase, thereby accelerating the curing speed. The silane groups will also form bonds with the metal substrate to increase adhesion and water resistance and salt spray resistance. Two or three silane groups with a relatively close distance will produce a synergistic effect, resulting in excellent results.

[0294] The water-based coatings 12 and 13 prepared from the polyisocyanate compositions B1 and B2 of Comparative Examples 1-2 do not contain the group structures shown in formula (1a), (1b), and (1c), and the isocyanate groups on the aliphatic polyisocyanate are modified by ethylene glycol monoallyl ether and trimethoxysilane successively to introduce only one silane group. For the polyisocyanate compositions of the present invention with the same molar amount of Si(OR)3 groups, the NCO values ​​of the polyisocyanate compositions B1 and B2 of Comparative Examples 1-2 are low due to the large amount of NCO groups consumed by the modification, and the prepared water-based coatings 12 and 13 have poor water resistance, salt spray resistance, adhesion, and drying speed. The water-based coating 14 of the polyisocyanate composition B3 of Comparative Example 3 has poor water resistance, salt spray resistance, adhesion, and drying speed due to the low proportion of the Si(OR)3 groups in the structure of formula (1a) in the polyisocyanate composition B3. In the water-based coating 15 of the polyisocyanate composition B4 of comparative example 4, since the proportion of the Si(OR)3 group in the structure of formula (1a) in the polyisocyanate composition B4 is too high, the gloss and hardness of the water-based coating 15 are poor. This may be because the excessively high proportion of silane groups causes the compatibility of the polyisocyanate composition B4 with the resin to deteriorate.

[0295] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and the present invention is also intended to include these modifications and modifications.

Claims

1. A polyisocyanate composition, characterized in that: Include: (1) Isocyanate group; (2) at least one of the groups represented by formula (1a) and (1b); Wherein, X is a C1-C8 alkylene group, Y is a monovalent C1-C8 alkyl group, and R is a methyl group or an ethyl group; (3) sulfonate groups bonded in the form of urea bonds or carbamate bonds and / or polyethylene glycol monoalkyl ether groups bonded in the form of carbamate bonds; In the polyisocyanate composition: the content of isocyanate groups is 12.0-26.0wt%; the total molar amount of Si(OR)3 groups in formula (1a) and (1b) is 2-30% of the total molar amount of isocyanate groups, carbamate groups and urea groups contained in the polyisocyanate composition; the total molar amount of sulfonate groups and / or polyethylene glycol monoalkyl ether groups is 0.7-7% of the total molar amount of isocyanate groups, carbamate groups and urea groups contained in the polyisocyanate composition.

2. The polyisocyanate composition according to claim 1, characterized in that: The isocyanate groups are isocyanate groups on aliphatic polyisocyanates; the groups represented by formula (1a) and (1b) are derived from isocyanate groups on aliphatic polyisocyanates respectively; the sulfonate groups bonded in the form of urea bonds or carbamate bonds, and / or the polyethylene glycol monoalkyl ether groups bonded in the form of carbamate bonds are derived from isocyanate groups on aliphatic polyisocyanates respectively.

3. The polyisocyanate composition according to claim 2, characterized in that: The group represented by formula (1a) is obtained by reacting the isocyanate group on the aliphatic polyisocyanate with the compound represented by formula (2a) for amine reaction, followed by addition reaction with trimethoxy monohydrogen silicon and / or triethoxy monohydrogen silicon; In formula (2a), X is a C1-C8 alkylene group, and Y is a monovalent C1-C8 alkyl group; The group represented by formula (1b) is obtained by reacting the isocyanate group on the aliphatic polyisocyanate with the compound represented by formula (2b) for amine reaction, followed by addition reaction with trimethoxy monohydrogen silicon and / or triethoxy monohydrogen silicon; In formula (2b), X is a C1-C8 alkylene group.

4. The polyisocyanate composition according to claim 2, characterized in that: The sulfonate group bonded in the form of a urea bond is obtained by reacting the isocyanate group on the aliphatic polyisocyanate with aminosulfonic acid; The sulfonate groups bonded in the form of carbamate bonds are obtained by reacting the isocyanate groups on the aliphatic polyisocyanate with hydroxysulfonic acid; The polyethylene glycol monoalkyl ether group bonded in the form of a carbamate bond is obtained by reacting an isocyanate group on an aliphatic polyisocyanate with a polyethylene glycol monoalkyl ether, wherein the polyethylene glycol monoalkyl ether is at least one of the structures shown in formula (2); In formula (2), the average value of n is 6-17, and Z is a monovalent C1-C4 alkyl group.

5. The polyisocyanate composition according to any one of claims 2 to 4, characterized in that: The aliphatic polyisocyanate is an aliphatic polyisocyanate formed based on at least one of 1,6-hexamethylene diisocyanate, 1,5-pentamethylene diisocyanate and isophorone diisocyanate as a polymerization monomer and having at least one of a uretdione structure, an isocyanurate structure, an allophanate structure, a biuret structure, an iminooxadiazinedione structure and an oxadiazinedione structure.

6. The polyisocyanate composition according to claim 4, characterized in that: The aminosulfonic acid is at least one of 2-(cyclohexylamino)ethanesulfonic acid, 3-(cyclohexylamino)propanesulfonic acid and 4-(cyclohexylamino)butanesulfonic acid; the hydroxysulfonic acid is at least one of 2-hydroxyethanesulfonic acid, 3-hydroxypropanesulfonic acid, 4-hydroxybutanesulfonic acid, 5-hydroxypentanesulfonic acid, 6-hydroxyhexanesulfonic acid, hydroxybenzenesulfonic acid and hydroxymethylbenzenesulfonic acid.

7. The polyisocyanate composition according to claim 4, characterized in that: The isocyanate group on the aliphatic polyisocyanate having a sulfonate group bonded in the form of a urea bond reacts with aminosulfonic acid, and then 20 mol % or more of N,N-dimethylbutylamine, N,N-diethylmethylamine, N,N-diisopropylethylamine, N,N-dimethylcyclohexylamine, N-methylpiperidine, and N-ethylmorpholine are added based on the molar amount of aminosulfonic acid for neutralization; The sulfonate group bonded in the form of a carbamate bond is an isocyanate group on an aliphatic polyisocyanate and reacts with hydroxysulfonic acid, and then at least one of N,N-dimethylbutylamine, N,N-diethylmethylamine, N,N-diisopropylethylamine, N,N-dimethylcyclohexylamine, N-methylpiperidine and N-ethylmorpholine is added in an amount of 20 mol % or more based on the molar amount of hydroxysulfonic acid for neutralization.

8. A method for preparing a polyisocyanate composition according to any one of claims 1 to 7, characterized in that: The following steps are involved: (S1) subjecting an aliphatic polyisocyanate to an amine reaction with a compound represented by formula (2a) and / or a compound represented by formula (2b), and then subjecting the aliphatic polyisocyanate to a hydrosilylation reaction with trimethoxysilane or triethoxysilane in the presence of a heavy metal catalyst; In formula (2a), X is a C1-C8 alkylene group, and Y is a monovalent C1-C8 alkyl group; In formula (2b), X is a C1-C8 alkylene group; (S2) reacting the reaction product of step (S1) with aminosulfonic acid and / or hydroxysulfonic acid and / or polyethylene glycol monoalkyl ether to obtain the polyisocyanate composition.

9. A water-based paint, characterized in that: The invention comprises a polyisocyanate composition as described in any one of claims 1 to 7 and a hydroxyl-containing aqueous resin.

10. An article coated with the water-based coating according to claim 9.

Images