阅读说明：本技术 单组份聚氨酯防水涂料组合物及其制备方法 (Single-component polyurethane waterproof coating composition and preparation method thereof ) 是由 何宏林 陈立义 于 2021-10-14 设计创作，主要内容包括：本申请属于防水涂料技术领域,提供一种单组份聚氨酯防水涂料组合物及其制备方法,单组份聚氨酯防水涂料组合物包括聚氨酯成膜树脂,分散剂和任选的添加剂；聚氨酯成膜树脂包括异氰酸酯封端的聚氨酯预聚物的分子链骨架,异氰酸酯封端的聚氨酯预聚物由端羟基聚丁二烯丙烯腈、聚醚多元醇与异氰酸酯的反应得到,聚氨酯成膜树脂包括与分子链骨架连接式1所示的链段结构,式1,其中R-(1)～R-(4)和n、n～(’)分别如本文所定义。本申请的单组份聚氨酯防水涂料组合物形成的涂膜具有优异的耐水性能。(The application belongs to the technical field of waterproof coatings, and provides a single-component polyurethane waterproof coating composition and a preparation method thereof, wherein the single-component polyurethane waterproof coating composition comprises polyurethane film-forming resin, a dispersing agent and an optional additive; the polyurethane film-forming resin comprises a molecular chain skeleton of isocyanate-terminated polyurethane prepolymer, the isocyanate-terminated polyurethane prepolymer is obtained by the reaction of hydroxyl-terminated polybutadiene acrylonitrile, polyether polyol and isocyanate, the polyurethane film-forming resin comprises a chain segment structure which is connected with the molecular chain skeleton and is shown in a formula 1, in the formula 1, the compound is shown in the specification,wherein R is 1 ~R 4 And n, n ’ Each as defined herein. The coating film formed by the one-component polyurethane waterproof coating composition has excellent water resistance.)

1. A one-component polyurethane waterproof coating composition comprises a polyurethane film-forming resin, a dispersant and optional additives;

wherein the polyurethane film-forming resin comprises a molecular chain skeleton of an isocyanate-terminated polyurethane prepolymer, the isocyanate-terminated polyurethane prepolymer is obtained by the reaction of hydroxyl-terminated polybutadiene acrylonitrile, polyether polyol and isocyanate, the polyurethane film-forming resin comprises a chain segment structure shown in a formula 1 connected with the molecular chain skeleton,

in the formula 1, the compound is shown in the specification,

in formula 1, R₁、R₂、R₃、R₄Each independently selected from、And R is₁、R₂、R₃、R₄One or both of them are，R₅Selected from alkyl or unsaturated alkyl with 3-17 carbon atoms; r^’Selected from alkyl with 1-5 carbon atoms; n, n^’Each independently is an integer of 1 to 25.

2. The one-component polyurethane waterproof coating composition according to claim 1, wherein R is^’Selected from alkyl with 1-3 carbon atoms.

3. The one-component polyurethane waterproof coating composition according to claim 1, wherein the molecular chain skeleton comprises a segment structure represented by formula 2,

in the formula (2), the first and second groups,

in formula 2, x is more than or equal to 1 and less than or equal to 50, and y is more than or equal to 1 and less than or equal to 10.

4. The one-component polyurethane waterproof coating composition of claim 1, wherein the polyurethane film-forming resin accounts for 40-80 wt% of the one-component polyurethane waterproof coating composition.

5. The one-component polyurethane waterproof coating composition of claim 1, wherein the number average molecular weight of the hydroxyl-terminated polybutadiene acrylonitrile is not less than 2500, and the hydroxyl value of the hydroxyl-terminated polybutadiene acrylonitrile is 0.55-0.70 mmol/g; and/or

The polyether polyol is trifunctional polyether polyol; and/or

The isocyanate includes a diisocyanate including at least one of an aromatic diisocyanate and an aliphatic diisocyanate.

6. The one-component polyurethane waterproof coating composition according to claim 5, wherein the isocyanate further comprises L-lysine triisocyanate, and the mass ratio of the L-lysine triisocyanate to the diisocyanate is 0.2 or less.

7. The one-component polyurethane waterproof coating composition according to claim 5, wherein the diisocyanate includes at least one of toluene diisocyanate, diphenylmethane diisocyanate.

8. The one-pack polyurethane waterproofing coating composition according to claim 1, wherein the dispersant is at least one selected from the group consisting of ethyl acetate, propylene glycol methyl ether acetate, butyl acetate, xylene, and trimethylbenzene; the mass ratio of the dispersing agent to the polyurethane film-forming resin is 0.1: 1-0.15: 1.

9. The one-component polyurethane waterproofing coating composition according to any one of claims 1 to 8, wherein the optional additive comprises a first catalyst to hydrolyze siloxane bonds in the polyurethane film-forming resin in the presence of the first catalyst, the mass ratio of the first catalyst to the polyurethane film-forming resin is 0.001:1 to 0.008:1, and the first catalyst is selected from at least one of dibutyltin dilaurate, stannous octoate, and lead isooctanoate.

10. The one-component polyurethane waterproof coating composition of claim 9, wherein the optional additives further comprise a pigment and a filler, the pigment and filler is at least one selected from nano calcium carbonate, fumed silica, heavy calcium carbonate, kaolin, silica micropowder and carbon black, and the mass ratio of the pigment and the filler to the polyurethane film-forming resin is 0.3: 1-0.4: 1; and/or

The optional additive also comprises a plasticizer, the plasticizer is selected from at least one of diisononyl phthalate, trioctyl phosphate, citrate and chlorinated paraffin plasticizer, and the mass ratio of the plasticizer to the polyurethane film-forming resin is 0.05: 1-0.1: 1.

11. The one-component polyurethane waterproof coating composition according to claim 10, wherein the isocyanate terminated polyurethane prepolymer is obtained by reacting 100 parts by weight of hydroxyl terminated polybutadiene acrylonitrile, 45 to 73 parts by weight of polyether polyol and 30 to 75 parts by weight of isocyanate in the presence of 0.2 to 1 part by weight of a second catalyst;

the chain segment structure shown in the formula 1 is obtained by reacting 13-40 parts by weight of a blocking agent with the isocyanate-terminated polyurethane prepolymer, wherein the blocking agent comprises a compound shown in a formula 3,

in the formula 3, the first step is,

in formula 3, R_6、R₇、R₈、R₉Each independently selected from、And R is_6、R₇、R₈、R₉Either or both of them are，R₁₀Selected from alkyl or unsaturated alkyl with 3-17 carbon atoms;

R^’’selected from alkyl with 1-5 carbon atoms; m, m^’Each independently is an integer of 1 to 25.

12. The one-component polyurethane waterproof coating composition according to claim 11, wherein R is^’’Selected from alkyl with 1-3 carbon atoms.

13. The one-component polyurethane waterproofing coating composition according to claim 11, wherein the second catalyst is selected from at least one of dibutyltin dilaurate, stannous octoate, lead isooctanoate; and/or

The isocyanate comprises 30-60 parts by weight of diisocyanate and 0-15 parts by weight of L-lysine triisocyanate.

14. The one-component polyurethane waterproofing coating composition according to claim 1, wherein the optional additives include a first catalyst selected from at least one of dibutyltin dilaurate, stannous octoate, lead isooctanoate, a pigment filler, a plasticizer,

the single-component polyurethane waterproof coating composition comprises, by weight, 40-80% of polyurethane film-forming resin, 4.0-12% of dispersing agent, 0.04-0.64% of first catalyst, 12-36% of pigment and filler, and 2.0-12% of plasticizer, wherein the total weight of the single-component polyurethane waterproof coating composition is 100%.

15. A method for preparing a one-pack polyurethane waterproof coating composition for preparing the one-pack polyurethane waterproof coating composition according to any one of claims 1 to 14, the method comprising:

providing an isocyanate-terminated polyurethane prepolymer, wherein the isocyanate-terminated polyurethane prepolymer comprises a molecular chain obtained by reacting 100 parts by weight of hydroxyl-terminated polybutadiene acrylonitrile, 45-73 parts by weight of polyether polyol and 30-75 parts by weight of isocyanate in the presence of 0.2-1 part by weight of a second catalyst;

a step of performing a capping reaction comprising reacting the isocyanate-terminated polyurethane prepolymer with 13 to 40 parts by weight of a capping agent in 20 to 40 parts by weight of a dispersant at a first temperature to obtain a mixture of the polyurethane film forming resin of any one of claims 1 to 14 and the dispersant, the first temperature being 70 to 100 ℃;

the end-capping reagent comprises a compound shown as a formula 3,

in the formula 3, the first step is,

in formula 3, R_6、R₇、R₈、R₉Each independently selected from、And R is_6、R₇、R₈、R₉Either or both of them are，R₁₀Selected from alkyl or unsaturated alkyl with 3-17 carbon atoms;

R^’’selected from alkyl with 1-5 carbon atoms; m, m^’Each independently is an integer of 1 to 25.

16. The method of claim 15, wherein R^’’Selected from alkyl with 1-3 carbon atoms.

17. The method of claim 15, wherein the amount of-OH to-NCO species in the hydroxyl-terminated polybutadiene acrylonitrile, the polyether polyol, and the isocyanate is from 1:1.9 to 1: 2.3.

18. The method of claim 15, wherein the providing an isocyanate-terminated polyurethane prepolymer comprises:

a step of preparing a slurry comprising uniformly mixing and dehydrating a first raw material comprising the hydroxyl-terminated polybutadiene and the polyether polyol to obtain the slurry;

a step of preparing an isocyanate terminated polyurethane prepolymer, comprising reacting hydroxyl terminated polybutadiene and polyether polyol in the slurry with the isocyanate in the presence of the second catalyst at a second temperature, thereby obtaining the isocyanate terminated polyurethane prepolymer, wherein the second temperature is 70-90 ℃.

19. The method of claim 18, wherein the first raw material further comprises 13 to 26 parts by weight of a plasticizer selected from at least one of diisononyl phthalate, trioctyl phosphate, citrate esters, chlorinated paraffin-based plasticizers; and/or

The first raw material further comprises 65-105 parts by weight of pigment and filler, and the pigment and filler is selected from at least one of nano calcium carbonate, fumed silica, heavy calcium, kaolin, silica micropowder and carbon black.

20. The method of claim 15, further comprising:

adding a first catalyst, wherein the step of adding the first catalyst comprises the steps of adding 0.3-2 parts by weight of the first catalyst into the mixture of the polyurethane film-forming resin and the dispersing agent, and uniformly mixing the mixture of the polyurethane film-forming resin and the dispersing agent with the first catalyst;

the first catalyst is at least one selected from dibutyltin dilaurate, stannous octoate and lead isooctanoate.

Technical Field

The application belongs to the technical field of waterproof coatings, and particularly relates to a single-component polyurethane waterproof coating composition and a preparation method thereof.

Background

The polyurethane coating film has the characteristics of good elasticity and ductility, good cohesiveness, small volume shrinkage, seamless waterproof layer of the film, good base layer stretching deformation resistance, easy construction and the like. The single-component polyurethane waterproof coating is developed vigorously due to the advantages of low viscosity, small construction difficulty, long applicable period, stable performance and the like.

However, a coating film formed by the existing one-component polyurethane waterproof coating can be slowly hydrolyzed under the action of water vapor in the environment or under the condition of soaking, so that the coating film is poorly adhered to a base surface, even bulges, cracks and peels off from the base surface, and the use requirement of an underground high-humidity or soaking environment cannot be met.

Disclosure of Invention

The application provides a one-component polyurethane waterproof coating composition in a first aspect, which comprises a polyurethane film-forming resin, a dispersant and optional additives;

wherein the polyurethane film-forming resin comprises a molecular chain skeleton of an isocyanate-terminated polyurethane prepolymer, the isocyanate-terminated polyurethane prepolymer is obtained by the reaction of hydroxyl-terminated polybutadiene acrylonitrile, polyether polyol and isocyanate, the polyurethane film-forming resin comprises a chain segment structure shown in a formula 1 connected with the molecular chain skeleton,

in the formula 1, the compound is shown in the specification,

in formula 1, R₁、R₂、R₃、R₄Each independently selected from、And R is₁、R₂、R₃、R₄One or both of them are，R₅Selected from alkyl or unsaturated alkyl with 3-17 carbon atoms; r^’Selected from alkyl with 1-5 carbon atoms, preferably from alkyl with 1-3 carbon atoms; n, n^’Each independently is an integer of 1 to 25.

The one-component polyurethane waterproof coating composition according to the first aspect of the present application has a specific molecular chain structure, thereby having excellent adhesion ability and hydrophobic property. The single-component polyurethane waterproof coating composition provided by the application is not easy to generate the phenomena of pinholes and foaming in the process of forming a coating, the formed coating has excellent adhesive property and hydrophobicity, and the hydrolysis or degradation of the coating in the use process can be effectively avoided. A coating film formed by the single-component polyurethane waterproof coating composition has excellent water resistance, and can meet the use requirement of underground high-humidity or water-immersed environment.

In an alternative embodiment of the first aspect of the present application, the molecular chain skeleton comprises a segment structure represented by formula 2,

in the formula (2), the first and second groups,

in formula 2, x is more than or equal to 1 and less than or equal to 50, and y is more than or equal to 1 and less than or equal to 10.

In an optional embodiment of the first aspect of the present application, the polyurethane film-forming resin accounts for 40wt% to 80wt% of the one-component polyurethane waterproof coating composition.

In an alternative embodiment of the first aspect of the present application, the hydroxyl-terminated polybutadiene acrylonitrile has a number average molecular weight of 2500 or more and a hydroxyl value of 0.55 to 0.70 mmol/g.

In an alternative embodiment of the first aspect of the present application, the polyether polyol is a trifunctional polyether polyol.

In an alternative embodiment of the first aspect of the present application, the isocyanate comprises a diisocyanate. Preferably, the isocyanate also comprises L-lysine triisocyanate, and the mass ratio of the L-lysine triisocyanate to the diisocyanate is less than or equal to 0.2.

The diisocyanate includes at least one of aromatic diisocyanate and aliphatic diisocyanate, and preferably includes at least one of toluene diisocyanate and diphenylmethane diisocyanate.

In an alternative embodiment of the first aspect of the present application, the dispersant is at least one selected from the group consisting of ethyl acetate, propylene glycol methyl ether acetate, butyl acetate, xylene, and trimethylbenzene; the mass ratio of the dispersing agent to the polyurethane film-forming resin is 0.1: 1-0.15: 1.

In an alternative embodiment of the first aspect of the present application, the above-mentioned optional additives comprise a first catalyst to hydrolyze siloxane bonds in the polyurethane film-forming resin in the presence of the first catalyst. Specifically, the mass ratio of the first catalyst to the polyurethane film-forming resin is 0.001: 1-0.008: 1. More specifically, the first catalyst is selected from at least one of dibutyltin dilaurate, stannous octoate, lead isooctanoate.

In an alternative embodiment of the first aspect of the present application, the above-mentioned optional additives further comprise a pigment and a filler. Specifically, the pigment and filler is at least one of nano calcium carbonate, fumed silica, heavy calcium, kaolin, silica micropowder and carbon black. The mass ratio of the pigment filler to the polyurethane film-forming resin is 0.3: 1-0.4: 1.

In an alternative embodiment of the first aspect of the present application, the above-mentioned optional additives further comprise a plasticizer, specifically, the plasticizer is at least one of nonyl ester, trioctyl phosphate, citrate ester, chlorinated paraffin-based plasticizer. The mass ratio of the plasticizer to the polyurethane film-forming resin is 0.05: 1-0.1: 1.

In an alternative embodiment of the first aspect of the present application, the isocyanate terminated polyurethane prepolymer is obtained by reacting 100 parts by weight of hydroxyl terminated polybutadiene acrylonitrile, 45 to 73 parts by weight of polyether polyol and 30 to 75 parts by weight of isocyanate in the presence of 0.2 to 1 part by weight of a second catalyst;

the chain segment structure shown in the formula 1 is obtained by reacting 13-40 parts by weight of a blocking agent with the isocyanate-terminated polyurethane prepolymer, wherein the blocking agent comprises a compound shown in a formula 3,

in the formula 3, the first step is,

in formula 3, R₆、R₇、R₈、R₉Each independently selected from、And R is_6、R₇、R₈、R₉Either or both of them are，R₁₀Selected from alkyl or unsaturated alkyl with 3-17 carbon atoms;

R^’’selected from alkyl with 1-5 carbon atoms, preferably from alkyl with 1-3 carbon atoms; m, m^’Each independently is an integer of 1 to 25.

In an alternative embodiment of the first aspect of the present application, the second catalyst is selected from at least one of dibutyltin dilaurate, stannous octoate, lead isooctanoate;

in an alternative embodiment of the first aspect of the present application, the isocyanate comprises 30 to 60 parts by weight of diisocyanate and 0 to 15 parts by weight of L-lysine triisocyanate.

In an alternative embodiment of the first aspect of the present application, the optional additives comprise a first catalyst, a pigment filler, a plasticizer, the first catalyst being selected from at least one of dibutyltin dilaurate, stannous octoate, lead isooctanoate,

the single-component polyurethane waterproof coating composition comprises, by weight, 40-80% of polyurethane film-forming resin, 4.0-12% of a dispersing agent, 0.04-0.64% of a first catalyst, 12-36% of a pigment filler and 2.0-12% of a plasticizer, wherein the total weight of the single-component polyurethane waterproof coating composition is 100%.

The second aspect of the present application provides a method for preparing a one-component polyurethane waterproof coating composition, comprising:

providing an isocyanate-terminated polyurethane prepolymer, wherein the isocyanate-terminated polyurethane prepolymer comprises a molecular chain obtained by reacting 100 parts by weight of hydroxyl-terminated polybutadiene acrylonitrile, 45-73 parts by weight of polyether polyol and 30-75 parts by weight of isocyanate in the presence of 0.2-1 part by weight of a second catalyst;

a step of carrying out a blocking reaction, comprising reacting an isocyanate-terminated polyurethane prepolymer with 13 to 40 parts by weight of a blocking agent in 20 to 40 parts by weight of a dispersant at a first temperature, thereby obtaining a mixture of a polyurethane film-forming resin according to any one of the embodiments of the first aspect of the present application and the dispersant, the first temperature being 70 to 100 ℃;

the end-capping reagent comprises a compound shown in a formula 3,

in the formula 3, the first step is,

in formula 3, R_6、R₇、R₈、R₉Each independently selected from、And R is_6、R₇、R₈、R₉Either or both of them are，R₁₀Selected from alkyl or unsaturated alkyl with 3-17 carbon atoms;

R^’’selected from alkyl with 1-5 carbon atoms, preferably from alkyl with 1-3 carbon atoms; m, m^’Each independently is an integer of 1 to 25.

According to the method for preparing the one-component polyurethane waterproof coating composition of the second aspect of the present application, the obtained one-component polyurethane waterproof coating composition has a specific molecular chain structure, thereby having excellent adhesion ability and hydrophobic property. The single-component polyurethane waterproof coating composition provided by the application is not easy to generate the phenomena of pinholes and foaming in the process of forming a coating, the formed coating has excellent adhesive property and hydrophobicity, and the hydrolysis or degradation of the coating in the use process can be effectively avoided. A coating film formed by the single-component polyurethane waterproof coating composition has excellent water resistance, and can meet the use requirement of underground high-humidity or water-immersed environment.

In an alternative embodiment of the second aspect of the present application, the hydroxyl-terminated polybutadiene acrylonitrile has a number average molecular weight of 2500 or more and a hydroxyl value of 0.55 to 0.70 mmol/g.

In an alternative embodiment of the second aspect of the present application, the polyether polyol is a trifunctional polyether polyol.

In an alternative embodiment of the second aspect of the present application,

the above-mentioned isocyanates include diisocyanates. Preferably, the isocyanate also comprises L-lysine triisocyanate, and the mass ratio of the L-lysine triisocyanate to the diisocyanate is less than or equal to 0.2.

The diisocyanate includes at least one of aromatic diisocyanate and aliphatic diisocyanate, and preferably includes at least one of toluene diisocyanate and diphenylmethane diisocyanate.

In an alternative embodiment of the second aspect of the present application, the dispersant is at least one selected from the group consisting of ethyl acetate, propylene glycol methyl ether acetate, butyl acetate, xylene, and trimethylbenzene.

In an alternative embodiment of the second aspect of the present application, the second catalyst is at least one selected from the group consisting of dibutyltin dilaurate, stannous octoate, lead isooctanoate.

In an alternative embodiment of the second aspect of the present application, the ratio of the amounts of the-OH to-NCO in the hydroxyl-terminated polybutadiene acrylonitrile, polyether polyol and isocyanate is 1:1.9 to 1: 2.3.

In an alternative embodiment of the second aspect of the present application, the above-mentioned isocyanate-terminated polyurethane prepolymer comprises:

a step of preparing a slurry, which comprises uniformly mixing and dehydrating a first raw material to obtain a slurry, wherein the first raw material comprises hydroxyl-terminated polybutadiene and polyether polyol;

and a step of preparing an isocyanate-terminated polyurethane prepolymer, which comprises reacting hydroxyl-terminated polybutadiene and polyether polyol in the slurry with isocyanate in the presence of a second catalyst at a second temperature to obtain the isocyanate-terminated polyurethane prepolymer, wherein the second temperature is 70-90 ℃.

In an alternative embodiment of the second aspect of the present application, the isocyanate is 30 to 60 parts by weight of diisocyanate and 0 to 15 parts by weight of L-lysine triisocyanate.

In an alternative embodiment of the second aspect of the present application, the first raw material further includes 13 to 26 parts by weight of a plasticizer. Specifically, the plasticizer is at least one of nonyl ester, trioctyl phosphate, citrate, and chlorinated paraffin plasticizer.

In an optional embodiment of the second aspect of the present application, the first raw material further comprises 65 to 105 parts by weight of a pigment and a filler. Specifically, the pigment and filler is at least one of nano calcium carbonate, fumed silica, heavy calcium, kaolin, silica micropowder and carbon black.

In an alternative embodiment of the second aspect of the present application, the method further comprises:

and adding a first catalyst, wherein the step of adding the first catalyst comprises the step of adding 0.3-2 parts by weight of the first catalyst into the mixture of the polyurethane film-forming resin and the dispersing agent and uniformly mixing the mixture of the polyurethane film-forming resin and the dispersing agent and the first catalyst. The first catalyst is at least one selected from dibutyltin dilaurate, stannous octoate and lead isooctanoate.

Detailed Description

In order to make the purpose, technical solution and advantageous technical effects of the present invention clearer, the present invention is further described in detail with reference to the following embodiments. It should be understood that the embodiments described in this specification are only for the purpose of explaining the present application and are not intended to limit the present application.

For the sake of brevity, only some numerical ranges are explicitly disclosed herein. However, any lower limit may be combined with any upper limit to form ranges not explicitly recited; and any lower limit may be combined with any other lower limit to form a range not explicitly recited, and similarly any upper limit may be combined with any other upper limit to form a range not explicitly recited. Also, although not explicitly recited, each point or individual value between endpoints of a range is encompassed within the range. Thus, each point or individual value can form a range not explicitly recited as its own lower or upper limit in combination with any other point or individual value or in combination with other lower or upper limits.

In the description herein, when a composition is described as containing, comprising, or including a particular component, or when a process is described as containing, comprising, or including a particular process step, it is contemplated that the composition of the present application also consists essentially of, or consists of, the component, and that the process of the present application also consists essentially of, or consists of, the process step.

The use of the terms "comprising," "including," "containing," and "having" are generally to be construed as open-ended and non-limiting unless otherwise expressly specified.

In the description herein, it is to be noted that, unless otherwise specified, "above" and "below" are inclusive, and "a plurality" of "one or more" means two or more.

The above summary of the present application is not intended to describe each disclosed embodiment or every implementation of the present application. The following description more particularly exemplifies illustrative embodiments. At various points throughout this application, guidance is provided through a list of embodiments that can be used in various combinations. In each instance, the list is merely a representative group and should not be construed as exhaustive.

The polyurethane coating film has the characteristics of good elasticity and ductility, good cohesiveness, small volume shrinkage, seamless waterproof layer of the film, good base layer stretching deformation resistance, easy construction and the like. The single-component polyurethane waterproof coating is developed vigorously due to the advantages of low viscosity, small construction difficulty, long applicable period, stable performance and the like.

However, a coating film formed by the existing one-component polyurethane waterproof coating can be slowly hydrolyzed under the action of water vapor in the environment or under the condition of soaking, so that the coating film is poorly adhered to a base surface, even bulges, cracks and peels off from the base surface, and the use requirement of an underground high-humidity or soaking environment cannot be met.

In view of the above, the application provides a one-component polyurethane waterproof coating composition and a preparation method thereof.

The application provides a one-component polyurethane waterproof coating composition in a first aspect, which comprises a polyurethane film-forming resin, a dispersant and optional additives.

Wherein the polyurethane film-forming resin comprises a molecular chain skeleton of an isocyanate-terminated polyurethane prepolymer. The isocyanate-terminated polyurethane prepolymer is obtained by the reaction of hydroxyl-terminated polybutadiene acrylonitrile, polyether polyol and isocyanate. The polyurethane film-forming resin also comprises a chain segment structure shown in a formula 1 connected with the molecular chain skeleton,

in the formula 1, the compound is shown in the specification,

in formula 1, R₁、R₂、R₃、R₄Each independently selected from、And R is₁、R₂、R₃、R₄One or both of them are。R₅Selected from alkyl or unsaturated alkyl with 3-17 carbon atoms. R^’Selected from alkyl with 1-5 carbon atoms. R^’Preferably selected from alkyl groups having 1 to 3 carbon atoms. n, n^’Each independently is an integer of 1 to 25.

The hydroxyl-terminated polybutadiene acrylonitrile refers to polybutadiene acrylonitrile with two terminal groups of-OH in a molecular chain. Polyether polyol refers to an oligomer which contains ether bonds (-R-O-R-) in the main chain and contains more than 2 hydroxyl groups (-OH) in the terminal group or the side group.

The term "molecular chain skeleton" has the meaning known to the person skilled in the art. The polyurethane film-forming resin includes a molecular chain skeleton of an isocyanate-terminated polyurethane prepolymer, and means that a molecular chain of the polyurethane film-forming resin includes a main chain structure of the polyurethane prepolymer having the above-described specific structure. The polyurethane prepolymer having the above-mentioned specific structure is a polyurethane prepolymer having a urethane group in the middle, which is terminated with isocyanate.

The alkyl group and the unsaturated hydrocarbon group herein may have a straight chain structure, a branched structure, or a cyclic structure.

The inventor finds that the one-component polyurethane waterproof coating cannot meet the use requirement of underground high-humidity or water-soaking environment, the coating film formed by the one-component polyurethane waterproof coating does not have good hydrophobicity, and the coating film is easy to absorb water and is hydrolyzed or degraded due to poor hydrophobicity. The inventor also found that the poor water resistance of the one-component polyurethane waterproof coating is related to the adhesion of the coating film to the surface of the substrate. The insufficient adhesion between the coating film and the base surface causes the coating film to bulge and crack, thereby causing water channeling and further promoting the hydrolysis or degradation of the coating film.

The inventor researches and discovers that the polyurethane film-forming resin of the single-component polyurethane waterproof coating has a chain segment structure shown in formula 1, can release high-activity hydroxyl in the construction process, and the hydroxyl can be subjected to self-condensation reaction to form a three-dimensional reticular elastomer and can also be subjected to coupling reaction with a group on the surface of a substrate. Therefore, the stability and the adhesive property of the coating film can be improved, and the problems of coating film pinholes and foaming in the construction process can be solved. In addition, the epoxy group in the chain segment structure shown in the formula 1 and the nitrile group in the molecular chain skeleton obtained by the reaction of hydroxyl-terminated polybutadiene acrylonitrile, polyether polyol and isocyanate further improve the adhesive property of the coating film.

In addition, the inventor also finds that the molecular chain skeleton obtained by the reaction of hydroxyl-terminated polybutadiene acrylonitrile, polyether polyol and isocyanate and the chain segment structure shown in the formula 1 can also reduce the surface energy of the coating, so that the coating film formed by the one-component polyurethane waterproof coating composition provided by the first aspect of the application has certain hydrophobicity. Therefore, the anti-swelling property of the coating film to water can be improved, so that the coating film is prevented from being hydrolyzed or degraded due to water absorption and swelling in the using process, and the waterproof performance of the coating film is improved.

The one-component polyurethane waterproof coating composition according to the first aspect of the present application has a specific molecular chain structure, thereby having excellent adhesion ability and hydrophobic property. The single-component polyurethane waterproof coating composition provided by the application is not easy to generate the phenomena of pinholes and foaming in the process of forming a coating, the formed coating has excellent adhesive property and hydrophobicity, and the hydrolysis or degradation of the coating in the use process can be effectively avoided. A coating film formed by the single-component polyurethane waterproof coating composition has excellent water resistance, and can meet the use requirement of underground high-humidity or water-immersed environment.

In some embodiments, the molecular chain skeleton may include a segment structure represented by formula 2,

in the formula (2), the first and second groups,

in formula 2, x is more than or equal to 1 and less than or equal to 50, and y is more than or equal to 1 and less than or equal to 10. Formula 2 is a segment structure contained in a product obtained by reacting hydroxyl-terminated polybutadiene acrylonitrile with isocyanate. The chain segment structure contains nitrile groups, so that the single-component polyurethane waterproof coating composition has more excellent bonding performance.

In some embodiments, the mass percentage of the polyurethane film-forming resin may be from 40wt% to 80wt% based on the total mass of the one-component polyurethane waterproof coating composition.

The mass percentage of the polyurethane film-forming resin is in the proper range, so that the single-component polyurethane waterproof coating composition has proper solid content, proper operation period and curing rate are realized, and the construction difficulty is reduced. In addition, the one-component polyurethane waterproof coating composition has a proper curing rate, and can be used for enabling a formed coating film to be tightly combined with the surface of a base material, reducing the possibility of water channeling and further improving the water resistance of the coating film.

In some embodiments, the hydroxyl terminated polybutadiene acrylonitrile may have a number average molecular weight of 2500 or more. The hydroxyl value of the hydroxyl-terminated polybutadiene acrylonitrile can be 0.55-0.70 mmol/g.

The number average molecular weight and the hydroxyl value of the hydroxyl-terminated polybutadiene acrylonitrile are in the proper ranges, so that the molecular chain skeleton of the polyurethane film-forming resin has a proper amount of nitrile groups. Thus, the adhesive property between a coating film formed by the one-component polyurethane waterproof coating composition and the surface of a base material can be improved, and the hydrophobic property of the coating film can be enhanced, so that the water resistance of the coating film is further improved.

In some embodiments, the polyether polyol may be a trifunctional polyether polyol, for example, the eastern bluestar polyether polyol EP330N or polyether polyol MN 1000.

The polyether polyol has proper functionality, so that the molecular chain skeleton of the polyurethane film-forming resin has a proper cross-linking structure, and the single-component polyurethane waterproof coating composition has stability and operability.

In some embodiments, the isocyanate may comprise a diisocyanate. The diisocyanate may include at least one of a diisocyanate and an aliphatic diisocyanate, and for example, may include at least one of 1, 6-Hexamethylene Diisocyanate (HDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), 4' -dicyclohexylmethane diisocyanate (HMDI), tetramethylm-xylylene diisocyanate (TMXDI), p-tetramethylxylylene diisocyanate, trimethylhexamethylene diisocyanate, and Toluene Diisocyanate (TDI). The diisocyanate may preferably include at least one of Toluene Diisocyanate (TDI) and diphenylmethane diisocyanate (MDI).

In some embodiments, the isocyanate may also include L-lysine triisocyanate. In the isocyanate, the mass ratio of L-lysine triisocyanate to the diisocyanate is less than or equal to 0.2.

The isocyanate is selected from the diisocyanate and the L-lysine triisocyanate, and the crosslinking structure and the activity of a molecular chain framework of the polyurethane film-forming resin can be further adjusted, so that the drying time of the waterproof coating film is adjusted, the single-component polyurethane waterproof coating composition is more stable and operable, and the bonding property of the coating film is improved.

In some embodiments, the dispersant may be selected from at least one of ethyl acetate, propylene glycol methyl ether acetate, butyl acetate, xylene, trimethylbenzene. The mass ratio of the dispersing agent to the polyurethane film-forming resin can be 0.1: 1-0.15: 1.

The single-component polyurethane waterproof coating composition has appropriate solid content due to appropriate types and dosage of the dispersant, so that the single-component polyurethane waterproof coating composition has appropriate construction viscosity and wettability, and the permeability and the adhesive property to the surface of a base material are improved.

In some embodiments, the optional additives described above may include a first catalyst to hydrolyze siloxane bonds in the polyurethane film-forming resin in the presence of the first catalyst. Specifically, the mass ratio of the first catalyst to the polyurethane film-forming resin may be 0.001:1 to 0.008: 1. More specifically, the first catalyst may be selected from at least one of dibutyltin dilaurate, stannous octoate, lead isooctanoate.

The single-component polyurethane waterproof coating composition contains the first catalyst, so that the siloxane bond in the polyurethane film-forming resin can be promoted to be fully hydrolyzed, high-activity silicon hydroxyl can be fully released, and the bonding performance of a coating film formed by the single-component polyurethane waterproof coating composition is improved.

In some embodiments, the optional additives described above may also include pigments and fillers. Specifically, the pigment and filler may be at least one of nano calcium carbonate, fumed silica, heavy calcium, kaolin, silica micropowder, and carbon black. The mass ratio of the pigment filler to the polyurethane film-forming resin can be 0.3: 1-0.4: 1.

The variety and the mass ratio of the pigment and the filler are in the proper range, so that a coating film formed by the single-component polyurethane waterproof coating composition has proper cost, strength, good corrosion resistance and durability.

In some embodiments, the optional additives described above may also include a plasticizer. Specifically, the plasticizer may be at least one of diisononyl phthalate, trioctyl phosphate, citrate, chlorinated paraffin-based plasticizers. The mass ratio of the plasticizer to the polyurethane film-forming resin can be 0.05: 1-0.1: 1.

The plasticizer is used in an amount within the above-mentioned suitable range so that the coating film formed from the one-part polyurethane waterproof coating composition has suitable cost, high strength, good displacement resistance or tensile properties.

In some embodiments, the isocyanate terminated polyurethane prepolymer may be obtained by reacting 100 parts by weight of hydroxyl terminated polybutadiene acrylonitrile, 45 to 73 parts by weight of polyether polyol, and 30 to 75 parts by weight of isocyanate in the presence of 0.2 to 1 part by weight of the second catalyst.

The chain segment structure shown in the formula 1 can be obtained by reacting 13-40 parts by weight of a blocking agent with the isocyanate-terminated polyurethane prepolymer, wherein the blocking agent can comprise a compound shown in a formula 3,

in the formula 3, the first step is,

in formula 3, R_6、R₇、R₈、R₉Each independently selected from、And R is_6、R₇、R₈、R₉Either or both of them are，R₁₀Selected from alkyl or unsaturated alkyl with 3-17 carbon atoms;

R^’’selected from alkyl groups having 1 to 5 carbon atoms, preferablySelected from alkyl with 1-3 carbon atoms; m, m^’Each independently is an integer of 1 to 25.

In some embodiments, the second catalyst may be selected from at least one of dibutyltin dilaurate, stannous octoate, lead isooctanoate.

In some embodiments, the isocyanate may include 30 to 60 parts by weight of diisocyanate and 0 to 15 parts by weight of L-lysine triisocyanate.

In some embodiments, the optional additives include a first catalyst selected from at least one of dibutyltin dilaurate, stannous octoate, lead isooctanoate, a pigment filler, a plasticizer.

The single-component polyurethane waterproof coating composition comprises, by weight, 40-80% of polyurethane film-forming resin, 4.0-12% of a dispersing agent, 0.04-0.64% of a first catalyst, 12-36% of a pigment filler and 2.0-12% of a plasticizer, wherein the total weight of the single-component polyurethane waterproof coating composition is 100%.

In a second aspect, the present application provides a method for preparing a one-component polyurethane waterproof coating composition, the method comprising:

step S10, providing an isocyanate-terminated polyurethane prepolymer, wherein the isocyanate-terminated polyurethane prepolymer comprises a molecular chain obtained by reacting 100 parts by weight of hydroxyl-terminated polybutadiene acrylonitrile, 45-73 parts by weight of polyether polyol and 30-75 parts by weight of isocyanate in the presence of 0.2-1 part by weight of a second catalyst.

The method of the present application further comprises a step S20 for performing a blocking reaction comprising reacting the isocyanate-terminated polyurethane prepolymer with 13 to 40 parts by weight of a blocking agent in 20 to 40 parts by weight of a dispersant at a first temperature, the first temperature being 70 to 100 ℃, to obtain a mixture of a polyurethane film forming resin and a dispersant according to any embodiment of the first aspect of the present application.

The end-capping reagent comprises a compound shown in a formula 3,

in the formula 3, the first step is,

in formula 3, R_6、R₇、R₈、R₉Each independently selected from、And R is_6、R₇、R₈、R₉Either or both of them are，R₁₀Selected from alkyl or unsaturated alkyl with 3-17 carbon atoms. R^’’Selected from alkyl groups having 1 to 5 carbon atoms, preferably from alkyl groups having 1 to 3 carbon atoms. m, m^’Each independently is an integer of 1 to 25.

According to the method for preparing the one-component polyurethane waterproof coating composition of the second aspect of the present application, the obtained one-component polyurethane waterproof coating composition has a specific molecular chain structure, thereby having excellent adhesion ability and hydrophobic property. The single-component polyurethane waterproof coating composition provided by the application is not easy to generate the phenomena of pinholes and foaming in the process of forming a coating, the formed coating has excellent adhesive property and hydrophobicity, and the hydrolysis or degradation of the coating in the use process can be effectively avoided. A coating film formed by the single-component polyurethane waterproof coating composition has excellent water resistance, and can meet the use requirement of underground high-humidity or water-immersed environment.

In some embodiments, the hydroxyl terminated polybutadiene acrylonitrile may have a number average molecular weight of 2500 or more. The hydroxyl value of the hydroxyl-terminated polybutadiene acrylonitrile can be 0.55-0.70 mmol/g.

In some embodiments, the polyether polyol may be a trifunctional polyether polyol, for example, the eastern bluestar polyether polyol EP330N or polyether polyol MN 1000.

In some embodiments, the isocyanate may comprise a diisocyanate. The diisocyanate may include at least one of a diisocyanate and an aliphatic diisocyanate, and for example, may include at least one of 1, 6-Hexamethylene Diisocyanate (HDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), 4' -dicyclohexylmethane diisocyanate (HMDI), tetramethylm-xylylene diisocyanate (TMXDI), p-tetramethylxylylene diisocyanate, trimethylhexamethylene diisocyanate, and Toluene Diisocyanate (TDI). The diisocyanate may preferably include at least one of Toluene Diisocyanate (TDI) and diphenylmethane diisocyanate (MDI).

In some embodiments, the isocyanate may also include L-lysine triisocyanate. In the isocyanate, the mass ratio of L-lysine triisocyanate to the diisocyanate is less than or equal to 0.2.

The combination of the diisocyanate and the L-lysine triisocyanate can obtain polyurethane film-forming resin with proper crosslinking density, thereby enhancing the stability of a coating film formed by the one-component polyurethane waterproof coating composition

In some embodiments, the dispersant may be selected from at least one of ethyl acetate, propylene glycol methyl ether acetate, butyl acetate, xylene, trimethylbenzene.

In some embodiments, the second catalyst may be selected from at least one of dibutyltin dilaurate, stannous octoate, lead isooctanoate.

In some embodiments, the ratio of the amount of-OH to-NCO species in the hydroxyl terminated polybutadiene acrylonitrile, polyether polyol, and isocyanate may be from 1:1.9 to 1: 2.3.

The mass ratio of-OH to-NCO is within the above-mentioned suitable range, which ensures that the hydroxyl-terminated polybutadiene acrylonitrile, polyether polyol and isocyanate react to give an isocyanate-terminated polyurethane prepolymer.

In some embodiments, providing the isocyanate-terminated polyurethane prepolymer may specifically include a step of preparing a slurry and a step of preparing the isocyanate-terminated polyurethane prepolymer.

The step of preparing the slurry may include mixing a first raw material, which may include hydroxyl-terminated polybutadiene and polyether polyol, uniformly and dehydrating to obtain the slurry.

In the above step of preparing the slurry, the components in the first raw material may be uniformly mixed by a common mixing means such as a stirrer and a strong dispersing agent. The mixing technique is not particularly limited as long as the components in the first raw material can be uniformly mixed.

In the above step of preparing the slurry, the dehydration means removing a certain amount of water from the components in the first raw material to perform the subsequent reaction. The dehydration can be carried out by a conventional means such as a centrifugal dehydrator, a thickener, a filter, and a dryer. No particular limitation is imposed on the dehydration technique, so long as it allows the components in the first starting material to undergo the subsequent isocyanate-blocking reaction.

The step of preparing the isocyanate terminated polyurethane prepolymer may include reacting the hydroxyl terminated polybutadiene and the polyether polyol in the syrup with the isocyanate in the presence of the first catalyst at a second temperature, which may be 70 to 90 ℃, to obtain the isocyanate terminated polyurethane prepolymer.

In some embodiments, the isocyanate may be 30 to 60 parts by weight of diisocyanate and 0 to 15 parts by weight of L-lysine triisocyanate.

In some embodiments, the first raw material may further include 13 to 26 parts by weight of a plasticizer. The plasticizer may preferably be at least one of nonyl ester, trioctyl phosphate, citrate ester, and chlorinated paraffin-based plasticizer.

In some embodiments, the first raw material may further include 65 to 105 parts by weight of a pigment and filler. The pigment and filler may preferably be at least one of nano calcium carbonate, fumed silica, heavy calcium, kaolin, silica micropowder and carbon black.

In some embodiments, the method for preparing the one-component polyurethane waterproof coating composition may further include:

and a step S30 of adding the first catalyst, including adding 0.3-2 parts by weight of the first catalyst to the mixture of the polyurethane film-forming resin and the dispersant, and uniformly mixing the mixture of the polyurethane film-forming resin and the dispersant with the first catalyst.

In step S30, the first catalyst may be selected from at least one of dibutyltin dilaurate, stannous octoate, lead isooctanoate.

The capping agent represented by formula 3 herein can be obtained by a variety of means.

As an example, the blocking agent may be prepared by a method comprising the steps of:

a step of preparing an organosilicon-modified epoxy resin, which comprises dissolving a bisphenol a-type epoxy resin from which a certain amount of moisture has been removed in acetone, and reacting the bisphenol a-type epoxy resin with dihalomethyltrialkoxysilane at a certain temperature to obtain an organosilicon-modified epoxy resin;

and a step of preparing an end-capping reagent, in which the organosilicon-modified epoxy resin is reacted with an organic acid in the presence of N, N-Dimethylformamide (DMF) at a certain temperature to obtain the end-capping reagent.

In a specific example, the bisphenol a epoxy resin may be bisphenol a epoxy resin E44, the dihalomethyltrialkoxysilane may be dichloromethyltriethoxysilane, the mass ratio of E44 to dichloromethyltriethoxysilane may be 2:1, and acetone accounts for 10% to 20% of the total mass of the raw materials for preparing the silicone-modified epoxy resin. The organic acid can be one or more of n-butyric acid, n-pelargonic acid, n-caprylic acid, lauric acid, stearic acid and oleic acid. The ratio of the amount of the organic silicon-modified epoxy resin to the amount of the organic acid may be 1:1 to 1: 4. The amount of DMF added may be from three to five parts per million of the total mass of the reactants in the step of preparing the capping agent.

It should be noted that, in the preparation of the end-capping reagent, there are various theoretically feasible ways to regulate the structure of the end-capping reagent shown in formula 3, such as adopting a different synthetic route, raw materials or preparation conditions from the above-mentioned methods. It should be understood that the above-mentioned preparation method of the blocking agent is only for explaining the present application and is not intended to limit the present application.

Examples

The present disclosure is more particularly described in the following examples that are intended as illustrations only, since various modifications and changes within the scope of the present disclosure will be apparent to those skilled in the art. Unless otherwise indicated, all parts, percentages, and ratios reported in the following examples are on a weight basis, and all reagents used in the examples are commercially available or synthesized according to conventional methods and can be used directly without further treatment, and the equipment used in the examples is commercially available.

The following examples used the following sources of starting materials:

hydroxyl-terminated polybutadiene acrylonitrile: the molecular weight of type IV of Shandong Zibo Qilong chemical Co., Ltd is not less than 2500, and the hydroxyl value is 0.55-0.7 mmol/g.

Hydroxyl-terminated polybutadiene: the molecular weight of 2000-4300 and the hydroxyl value of 0.54-0.64 mmol/g.

Polyether polyol: dow of Lanxingdong EP330N (functionality of 3, number average molecular weight of 5000), Dow of Lanxingdong MN1000 (functionality of 3, molecular weight of 1000), Dow of Lanxingdong DL-2000D (functionality of 2, molecular weight of 2000), were obtained from Jiangxi Dongdong chemical Co., Ltd.

End-capping agent: self-made, prepared by the following method:

dissolving bisphenol A epoxy resin E44 with a certain amount of water removed in acetone, and stirring until the bisphenol A epoxy resin E44 is dissolved; adding dichloromethyl triethoxysilane into the E44 solution, wherein the mass ratio of E44 to dichloromethyl triethoxysilane is 2: 1; and (3) reacting E44 with dichloromethyl triethoxysilane at 80-95 ℃ for 4-5 h, vacuumizing, and distilling under reduced pressure to obtain the organosilicon modified epoxy resin.

The synthetic route of the above reaction is as follows:

mixing the organosilicon modified epoxy resin and n-butyric acid in a molar ratio of 1:2, and reacting the organosilicon modified epoxy resin and the n-butyric acid in the presence of DMF for 4-5 h at 110-120 ℃ to obtain the end capping agents used in the following examples and comparative examples.

The synthetic route for this reaction is as follows:

other raw materials which are not particularly described are all common commercial products.

Example 1

Adding hydroxyl polybutadiene acrylonitrile, polyether polyol and a plasticizer into a strong dispersing machine, gradually adding the pigment and the filler, and uniformly dispersing;

transferring the dispersed slurry into a reaction kettle, stirring and heating to 100-110 ℃, and dehydrating for 2-3 hours under the relative vacuum degree of-0.08 to-0.1 MPa;

reducing the temperature to 70-80 ℃, adding a dispersing agent, gradually adding isocyanate, stirring, adding a second catalyst, heating to 75-85 ℃, and reacting for 3-4 hours; controlling the dripping speed of isocyanate to be 1-2 parts by weight/s;

keeping the temperature at 75-85 ℃, adding an end-capping agent, and continuously stirring for reaction for 2-3 hours;

cooling to 50-60 ℃, adding a first catalyst, and stirring for 0.5-1 hour;

cooling to below 50 ℃, charging nitrogen for protection, and discharging to obtain the single-component polyurethane waterproof coating composition.

In the preparation process, the used hydroxyl-terminated polybutadiene acrylonitrile is 100 parts by weight, the used polyether polyol is 50 parts by weight of polyether polyol EP330N, the used dispersing agent is 30 parts by weight of toluene, the used plasticizer is 25 parts by weight of diisononyl phthalate, the used pigment and filler is 70 parts by weight of nano calcium carbonate and 25 parts by weight of fumed silica, the used isocyanate is 50 parts by weight of TDI and 10 parts by weight of L-lysine triisocyanate, the used second catalyst is 0.3 part by weight of stannous octoate, the added amount of the used blocking agent is 30 parts by weight, and the used first catalyst is 0.6 part by weight of stannous octoate.

Example 2

The procedure described in example 1 was repeated, with the changes that:

the hydroxyl-terminated polybutadiene acrylonitrile is 100 parts by weight, the polyether polyol is 70 parts by weight of polyether polyol EP330N, the dispersing agent is 40 parts by weight of butyl acetate, the plasticizer is 26 parts by weight of trioctyl phosphate, the pigment and filler is 60 parts by weight of nano calcium carbonate and 30 parts by weight of fumed silica, the isocyanate is 55 parts by weight of TDI and 7 parts by weight of L-lysine triisocyanate, the second catalyst is 0.5 part by weight of stannous octoate, the addition amount of the blocking agent is 40 parts by weight, and the first catalyst is 1 part by weight of stannous octoate.

Example 3

The procedure described in example 1 was repeated, with the changes that:

the hydroxyl-terminated polybutadiene acrylonitrile is 100 parts by weight, the polyether polyol is 50 parts by weight of polyether polyol EP330N, the dispersing agent is 35 parts by weight of butyl acetate, the plasticizer is 25 parts by weight of nonyl ester, the pigment and filler are 65 parts by weight of nano calcium carbonate and 25 parts by weight of fumed silica, the isocyanate is 55 parts by weight of 4,4' -dicyclohexylmethane diisocyanate (HMDI) and 5 parts by weight of L-lysine triisocyanate, the second catalyst is 0.2 part by weight of stannous octoate, the addition amount of the blocking agent is 30 parts by weight, and the first catalyst is 0.5 part by weight of stannous octoate.

Example 4

The procedure described in example 1 was repeated, with the changes that:

the hydroxyl-terminated polybutadiene acrylonitrile is 100 parts by weight, the polyether polyol is 60 parts by weight of polyether polyol MN1000, the dispersing agent is 25 parts by weight of butyl acetate, the plasticizer is 23 parts by weight of trioctyl phosphate, the pigment and filler are 60 parts by weight of nano calcium carbonate and 30 parts by weight of fumed silica, the isocyanate is 58 parts by weight of TDI and 10 parts by weight of L-lysine triisocyanate, the second catalyst is 0.3 part by weight of stannous octoate, the addition amount of the blocking agent is 35 parts by weight, and the first catalyst is 0.9 part by weight of stannous octoate.

Comparative example 1

The procedure described in example 1 was repeated, with the changes that:

no capping agent was used.

Comparative example 2

The procedure described in example 1 was repeated, with the changes that:

100 parts by weight of the hydroxyl-terminated polybutadiene acrylonitrile in example 1 was replaced with 100 parts by weight of the polyether polyol DL-2000D.

Comparative example 3

The procedure described in example 1 was repeated, with the changes that:

the capping agent in example 1 was replaced with 3-hydroxyethyl-1, 3-oxazolidine.

Comparative example 4

The procedure described in example 1 was repeated, with the changes that:

the polyether polyol was 70 parts by weight of polyether polyol DL-2000D and the capping agent in example 1 was replaced with 3-hydroxyethyl-1, 3-oxazolidine.

Comparative example 5

The procedure described in example 1 was repeated, with the changes that:

100 parts by weight of hydroxyl-terminated polybutadiene acrylonitrile in example 1 was replaced with 100 parts by weight of hydroxyl-terminated polybutadiene.

Test section

The performance test of the one-component polyurethane waterproof coating compositions of examples 1-4 and comparative examples 1-5 is carried out by referring to the standards of GB/T19250-.

The method for testing the strength retention rate of the water-soaking adhesion specifically comprises the following steps:

test pieces were prepared according to the method specified in GB/T16777-20087.1 (method A), and the initial adhesive strength of the test pieces was tested by curing under standard test conditions (23. + -. 2 ℃ C., relative humidity 50. + -. 10%) for 7 days. And completely soaking the test piece in water, taking out the test piece according to a preset time, and testing the bonding strength after the test piece is placed for 12 hours under the standard test condition.

Strength retention = (adhesive strength/initial adhesive strength) × 100%.

Table 1: performance test results of examples 1 to 4 and comparative examples 1 to 5

As can be seen from the above table, the one-part polyurethane waterproofing coating compositions of examples 1 to 4 are excellent in various aspects. The water-absorbing paint of the embodiments 1 to 4 still has higher strength retention rate after being soaked in water for 30 days, and the water absorption rate is far smaller than that of the comparative examples 1 to 5. This shows that the system plays a role in resisting swelling in hydrophobicity and crosslinking density, and the failure form of the test piece still maintains cohesive failure, and the bonding effect on the base material maintains good. Therefore, the one-component polyurethane waterproof coating composition provided by the embodiment of the application has a proper crosslinking density, the polyurethane film-forming resin has nitrile groups, epoxy groups and other functional groups, and can release high-activity silicon hydroxyl groups, and a formed coating film has strong adhesive force and hydrophobic property, so that the one-component polyurethane waterproof coating composition has excellent water resistance, and can keep good adhesive property even after being soaked in water. In example 3, HMDI was used instead of TDI, and the tensile strength, adhesive strength, elongation at break and other properties were all improved, but the tack-free time and the tack-free time of the product were increased. As can be seen from Table 1, the water-soaking adhesion performance and water absorption of comparative examples 1, 2, 3, 4 and 5 are all obviously different from those of comparative example 1, the retention rate of the adhesive strength of comparative examples 1,3 and 4 after soaking in water for 7 days is obviously reduced, and the adhesive strength is gradually reduced along with the prolonging of the soaking time, and the failure form is interface failure/partial cohesive failure. This shows that the coating films formed from the one-part polyurethane waterproofing coating compositions of comparative examples 1,3 and 4 have significantly reduced adhesion after soaking in water. Comparative examples 2 and 5 show that the use of hydroxyl-terminated polybutadiene acrylonitrile improves some of the bubble water bonding performance.

Therefore, the hydroxyl-terminated polybutadiene acrylonitrile and the specific end-capping agent are adopted, so that the bonding and water immersion resistance of a coating film formed by the single-component polyurethane waterproof coating composition to a base material can be greatly improved, and the resistance of a product to an underwater environment is improved.

While the invention has been described with reference to specific embodiments, the scope of the invention is not limited thereto, and those skilled in the art can easily conceive various equivalent modifications or substitutions within the technical scope of the invention. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.