Self-crosslinking polyurethane resin and application thereof, single-component solvent-free polyurethane waterproof coating and preparation method thereof

Abstract

The invention discloses self-crosslinking polyurethane resin and application thereof, and a single-component solvent-free polyurethane waterproof coating and a preparation method thereof. The coating comprises the following raw materials in parts by weight: 40-70 parts of polyether glycol; 30 to 50 parts of polyether triol; 70 to 120 parts of a plasticizer; 10 to 20 parts of epoxy resin; 140 to 220 parts of pigment and filler; 0.1 to 0.5 part of a dispersant; 1 to 2.5 parts of a defoaming agent; 20 to 30 parts of diisocyanate; 0.5 to 1.5 parts of a catalyst; and 10-18 parts of modified resin, and the modified resin is prepared by reacting a diamine compound with a hydroxyl-containing aldehyde compound and / or a hydroxyl-containing aldehyde compound. According to the single-component solvent-free polyurethane waterproof coating and the preparation method, the physical performance of a coating film of the coating can be improved, the VOC volatilization amount of the single-component solvent-free polyurethane waterproof coating can be effectively reduced, and air holes can be prevented from being generated in the coating film of the coating.

Description

Technical Field

[0001] The present application belongs to the technical field of polyurethane waterproof coatings, and in particular relates to a self-crosslinking polyurethane resin and its use, a single-component solvent-free polyurethane waterproof coating and its preparation method. Background Art

[0002] Polyurethane waterproof coating is a reaction-cured waterproof coating made by mixing isocyanate, polyether, etc. with prepolymers containing isocyanate groups, catalysts, additives, fillers, etc., and has the characteristics of high strength, high elongation, and good water resistance. Polyurethane waterproof coatings can be divided into solvent-based and solvent-free types according to whether organic solvents are added. Conventional polyurethane waterproof coating products will add a certain amount of organic solvents to the coating formula to reduce the viscosity of the finished coating to facilitate later construction and use. However, the current environmental protection requirements are getting higher and higher, and the content of volatile organic compounds (VOC) in coatings has been restricted one after another, so solvent-free polyurethane waterproof coatings have begun to enter the market.

[0003] Solvent-free polyurethane waterproof coatings generally use small molecule plasticizers such as tributyl acetyl citrate to replace part or all of the conventional macromolecular plasticizers to reduce the viscosity of the product. However, due to the poor plasticizing effect and high cost of small molecule plasticizers, the addition of small molecule plasticizers will reduce the physical properties of the coating such as tensile strength and tear strength, and the resin content in the coating needs to be increased to ensure the physical properties of the coating, but this will significantly increase the cost of the coating. In addition, the -NCO group in the polyurethane waterproof coating will react with water vapor in the air to generate CO2, resulting in pores in the coating film, which will seriously affect the physical properties and waterproof effect of the coating film. To avoid this problem, polyurethane waterproof coatings often use latent curing agents, but latent curing agents will still release aldehyde / ketone organic volatile gases during the hydrolysis process, resulting in the VOC release of solvent-free polyurethane waterproof coatings is still high and affects the health of construction workers. Summary of the invention

[0004] The embodiments of the present application provide a self-crosslinking polyurethane resin and its use, a one-component solvent-free polyurethane waterproof coating and a preparation method, which can improve the physical properties of the coating film, while reducing the VOC volatility of the one-component solvent-free polyurethane waterproof coating and preventing the coating film from generating pores.

[0005] First, an embodiment of the present application provides a modified resin, including a compound shown in the following structural formula:

[0006]

[0007] In formula (1), R1 is selected from C1-C10 alkylene, C6-C10 arylene, C3-C8 cycloalkylene; R2 is selected from H, C1-C6 alkyl, aryl, C1-C6 hydroxyalkyl; R3 is selected from C1-C6 alkylene, arylene, and R3 is connected to a hydroxyl group. It should be noted that the hydroxyl group connected to R3 is the hydroxyl group connected to R3 in formula (1), and the hydroxyl group connected to R3 is located on the carbon chain of R3 or at the end of the carbon chain.

[0008] According to an embodiment of the present application, the compound having the structure shown in formula (1) is prepared by reacting a diamine compound with an aldehyde compound containing a hydroxyl group or a ketone compound containing a hydroxyl group.

[0009] According to an embodiment of the present application, the diamine compound is selected from at least one of ethylenediamine, propylenediamine, hexamethylenediamine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, trans-cyclopropane-1,2-diamine, 1,1-cyclobutanedimethylamine, 1,3-cyclobutanediamine, 1,3-cyclopentanediamine, 1,4-cyclohexyldiamine, and 1,2-cyclohexyldiamine.

[0010] According to an embodiment of the present application, the aldehyde compound or ketone compound containing a hydroxyl group is selected from at least one of p-hydroxybenzaldehyde, 1,3-dihydroxyacetone, butanolaldehyde, hydroxyacetone, 2-hydroxybenzophenone, and hydroxypropiophenone.

[0011] According to an embodiment of the present application, the compound having the structure shown in formula (1) includes at least one of CH3CH(-HO)CH2CH=N-(CH2)2-N=CHCH2CH(-OH)CH3, CH3CH(-HO)CH2CH=N-(CH2)3-N=CHCH2CH(-OH)CH3, (HOCH2)2CH=N-(CH2)2-N=CH(CH2OH)2 and (HOCH2)2CH=N-(CH2)3-N=CH(CH2OH)2.

[0012] According to an embodiment of the present application, the compound of the structure shown in formula (1) includes at least one of CH3CH(-HO)CH2CH=N-Ph-N=CHCH2CH(-OH)CH3, (HOCH2)2C=N-Ph-N=C(CH2OH)2, wherein Ph is a phenylene group.

[0013] Second, the present application provides a method for preparing a modified resin, comprising: providing compounds represented by formula (2) and formula (3):

[0014]

[0015] In formula (2), R1 is selected from C1-C10 alkylene, C6-C10 arylene, C3-C8 cycloalkylene;

[0016]

[0017] In formula (3), R2 is selected from H, C1-C6 alkyl, aryl, C1-C6 hydroxyalkyl; R3 is selected from C1-C6 alkylene, arylene, and R3 is connected to a hydroxyl group;

[0018] The compounds represented by formula (2) and formula (3) are reacted at a molar ratio of (0.45-0.5):1 to obtain a compound represented by formula (1):

[0019]

[0020] In formula (1), R1 is selected from C1-C10 alkylene, C6-C10 arylene, C3-C8 cycloalkyl; R2 is selected from H, C1-C6 alkyl, aryl, C1-C6 hydroxyalkyl; R3 is selected from C1-C6 alkylene and arylene, and R3 is connected to a hydroxyl group. It should be noted that the hydroxyl group connected to R3 is the hydroxyl group connected to R3 in formula (1), and the hydroxyl group connected to R3 is located on the carbon chain of R3 or at the end of the carbon chain.

[0021] According to an embodiment of the second aspect of the present application, the diamine compound of the structure shown in formula (2) is selected from ethylenediamine, propylenediamine, hexamethylenediamine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, trans-cyclopropane-1,2-diamine, 1,1-cyclobutanedimethylamine, 1,3-cyclobutanediamine, 1,3-cyclopentanediamine, 1,4-cyclohexyldiamine, 1,2-cyclohexyldiamine or a combination thereof.

[0022] According to an embodiment of the second aspect of the present application, the aldehyde compound or ketone compound containing a hydroxyl group of the structure shown in formula (3) is selected from p-hydroxybenzaldehyde, 1,3-dihydroxyacetone, butanolaldehyde, hydroxyacetone, 2-hydroxybenzophenone, hydroxypropiophenone or a combination thereof.

[0023] According to an embodiment of the second aspect of the present application, the molar ratio of the structural compounds represented by formula (2) and formula (3) is (0.47-0.49):1.

[0024] Third, an embodiment of the present application provides a self-crosslinking polyurethane resin, which includes a compound having a structure shown in formula (5):

[0025]

[0026] In Formula 5, R1 is selected from C1-C10 alkylene, C6-C10 arylene, C3-C8 cycloalkylene; R2 is selected from H, C1-C6 alkyl, aryl, C1-C6 hydroxyalkyl; R3 is selected from C1-C6 alkylene, arylene, R is a prepolymer group prepared by diisocyanate and polyol and blocked by -NCO group, wherein the prepolymer is prepared by diisocyanate and polyol in a ratio of -NCO to -OH of 1.5-2.5. It should be noted that R is a prepolymer group prepared by diisocyanate and polyol and blocked by -NCO group, wherein -NCO at the end of the molecular chain of Formula (5) is a blocked -NCO group.

[0027] According to an embodiment of the third aspect of the present application, the raw materials for preparing the compound of the structure represented by formula (5) include the compound of the structure represented by formula (1) above, and the compound of the structure represented by formula (4):

[0028]

[0029] In formula (4), R is a prepolymer group terminated by -NCO groups prepared from diisocyanate and polyol; wherein the prepolymer is prepared from diisocyanate and polyol in a ratio of -NCO to -OH of 1.5 to 2.5.

[0030] In an embodiment of the present application, after the polyether polyol is connected with a diisocyanate and terminated with a -NCO group, a prepolymer having a structure shown in formula (4) reacts with a compound having a structure shown in formula (1), wherein the -NCO group at the end of formula (4) reacts with the -OH group in formula (1) to generate a compound having a structure shown in formula (5), i.e., a self-crosslinking polyurethane resin, wherein R is a prepolymer group after removing a -NCO group, i.e., a -NCO group at one end reacts with an anti--OH group.

[0031] In a fourth aspect, the present application provides a method for preparing a self-crosslinking polyurethane resin, comprising reacting a compound having a structure shown in formula (1) and a compound having a structure shown in formula (4) in a molar ratio of 1:(2 to 4.5) to prepare a self-crosslinking polyurethane resin.

[0032] According to an embodiment of the fourth aspect of the present application, the diisocyanate used to prepare the prepolymer represented by R is selected from hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate or a combination thereof; the polyol used to prepare the prepolymer represented by R is selected from polyether diols and / or polyether triols, and the molecular weight of the polyol is 1000 to 5000.

[0033] According to an embodiment of the fourth aspect of the present application, a self-crosslinking polyurethane resin is used to prepare a polyurethane waterproof coating.

[0034] In the fifth aspect, the embodiment of the present application provides a one-component solvent-free polyurethane waterproof coating, which includes, by weight: 40 to 70 parts of polyether diol; 30 to 50 parts of polyether triol; 70 to 120 parts of plasticizer; 10 to 20 parts of epoxy resin; 140 to 220 parts of pigments and fillers; 0.1 to 0.5 parts of dispersant; 1 to 2.5 parts of defoamer; 20 to 30 parts of diisocyanate; 0.5 to 1.5 parts of catalyst; 10 to 18 parts of modified resin, wherein the modified resin is prepared by reacting a diamine compound with a hydroxyl-containing aldehyde compound and / or a hydroxyl-containing aldehyde compound. Further, the modified resin may be the above-mentioned modified resin.

[0035] According to an embodiment of the fifth aspect of the present application, the molecular weight of the polyether diol and the polyether triol is 1000-5000.

[0036] According to an embodiment of the fifth aspect of the present application, the plasticizer is selected from chlorinated paraffins, citrates, phthalates, trioctyl phosphate or a combination thereof.

[0037] According to an embodiment of the fifth aspect of the present application, the epoxy resin is selected from bisphenol A epoxy resin, bisphenol F epoxy resin or a combination thereof.

[0038] According to the embodiment of the fifth aspect of the present application, the chlorinated paraffins can be selected from 52#, 54#, 56#, 58#, 60#, 62#, 68# or a combination thereof.

[0039] According to an embodiment of the fifth aspect of the present application, the citrate ester is selected from tributyl citrate, acetyl tributyl citrate or a combination thereof.

[0040] According to an embodiment of the fifth aspect of the present application, the phthalic acid is selected from phthalic acid esters, di(2-ethylhexyl) phthalate, dibutyl phthalate, dioctyl phthalate or a combination thereof.

[0041] According to an embodiment of the fifth aspect of the present application, the filler is selected from nano calcium carbonate, talc, fumed silica, barium sulfate, heavy calcium carbonate, light calcium carbonate, kaolin, carbon black, red iron oxide, titanium dioxide, yellow iron oxide, composite emerald green or a combination thereof.

[0042] According to the embodiment of the fifth aspect of the present application, the particle size of nano calcium carbonate, talc, fumed silica, barium sulfate, heavy calcium carbonate, light calcium carbonate, and kaolin is 800 mesh to 3000 mesh.

[0043] According to an embodiment of the fifth aspect of the present application, the dispersant is selected from a nonionic dispersant or an anionic dispersant or a combination thereof.

[0044] According to the embodiment of the fifth aspect of the present application, the nonionic dispersant is selected from the group consisting of nano-scale superdispersants DisuperS18, PX4522, PU4020 or a combination thereof.

[0045] According to an embodiment of the fifth aspect of the present application, the anionic dispersant is selected from BYK-110, BYK-052N, FA4644, FA4643, FA464 or a combination thereof.

[0046] According to an embodiment of the fifth aspect of the present application, the defoaming agent is selected from silicone defoaming agents, mineral oil defoaming agents or a combination thereof.

[0047] According to an embodiment of the fifth aspect of the present application, the diisocyanate is selected from one or more of hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, diphenylmethane diisocyanate, and toluene diisocyanate.

[0048] According to an embodiment of the fifth aspect of the present application, the catalyst is selected from dibutyltin dilaurate, stannous octoate, lead isooctanoate, bismuth isooctanoate or a combination thereof.

[0049] In a sixth aspect, the present application provides a method for preparing a one-component solvent-free polyurethane waterproof coating, comprising: dispersing and mixing polyether diol, polyether triol, plasticizer, epoxy resin, pigment, dispersant, and defoamer to obtain a first mixture; adding diisocyanate and a catalyst to the first mixture to obtain a second reaction mixture; adding a modified resin to the second reaction mixture to obtain a one-component solvent-free polyurethane waterproof coating.

[0050] The self-crosslinking polyurethane resin, one-component solvent-free polyurethane waterproof coating and preparation method of the embodiment of the present application, by adding a modified resin containing two hydroxyl groups, make the polyurethane waterproof coating act as the lipid hard segment of the polyurethane resin and be embedded in the polyurethane resin during the reaction and curing process, thereby improving the physical properties of the coating film. At the same time, during the hydrolysis of the modified resin, the aldehyde compound containing hydroxyl groups or the ketone compound containing hydroxyl groups obtained by hydrolysis of the modified resin act as a blocking agent, preferentially react with the -NCO group in the coating, and be embedded in the hard segment of the polyurethane resin, and will not volatilize, thereby reducing the generation of volatile organic matter; at the same time, the -NCO group in the coating preferentially reacts with the hydroxyl group after the hydrolysis of the modified resin, avoiding the reaction with moisture in the air to generate CO2, which can prevent the coating film from generating pores. DETAILED DESCRIPTION

[0051] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0052] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0053] In order to solve the problems of the prior art, the embodiments of the present application provide a self-crosslinking polyurethane resin and a preparation method and use thereof, a one-component solvent-free polyurethane waterproof coating and a preparation method thereof. The modified resin is first introduced below.

[0054] In a first aspect, an embodiment of the present application provides a modified resin, comprising a compound shown in the following structural formula:

[0055]

[0056] In formula (1), R1 is selected from C1-C10 alkylene, C6-C10 arylene, C3-C8 cycloalkylene; R2 is selected from H, C1-C6 alkyl, aryl, C1-C6 hydroxyalkyl; R3 is selected from C1-C6 alkylene, arylene, and R3 is connected to a hydroxyl group.

[0057] In the embodiments of the present application, the modified resin can be embedded in the polyurethane resin as the lipid hard segment of the polyurethane resin to improve the physical properties of the coating film, reduce the influence of small molecule plasticizers on the performance of the coating film, and improve the physical properties of the polyurethane resin coating film including tensile strength and tear strength. At the same time, the product of the modified resin in the hydrolysis process, the diamine, participates in the curing reaction of the coating as a chain extender, and the unblocked hydroxyl-containing aldehyde compound or hydroxyl-containing ketone compound remains in the polyurethane resin as a hard segment, reducing the volatile organic compound (VOC) during the curing reaction. And the -NCO group in the coating preferentially reacts with the hydroxyl group in the hydrolysis product of the modified resin to avoid reacting with water in the air to generate CO2, which can effectively prevent the coating film from generating pores.

[0058] The modified resin of the embodiment of the present application contains a ketimine or aldimine structure, and at least one hydroxyl group is present at each end of the ketimine or aldimine molecular structure, that is, at least two hydroxyl groups are present at both ends, which can react with the diisocyanate or -NCO group in the coating to generate a fat hard segment containing an isocyanate group, thereby improving the physical properties of the coating film. Even if the modified resin as a fat hard segment is hydrolyzed, the diamine released can also be used as a chain extender to participate in the curing reaction of the polyurethane waterproof coating, and the ketone compounds or aldehyde compounds containing hydroxyl groups produced by the hydrolysis can also preferentially react with -NCO groups through active hydroxyl groups, participate in the curing of the polyurethane waterproof coating, reduce the content of volatile organic compounds, avoid the -NCO groups in the coating from reacting with moisture in the air to generate CO2, and effectively prevent the coating film from generating pores.

[0059] In some embodiments, the modified resin, i.e., the compound of the structure shown in formula (1), is prepared by reacting a diamine compound with an aldehyde compound containing a hydroxyl group or a ketone compound containing a hydroxyl group. The diamine compound is selected from at least one of trans-cyclopropane-1,2-diamine, 1,1-cyclobutanedimethylamine, 1,3-cyclobutanediamine, 1,3-cyclopentanediamine, 1,4-cyclohexyldiamine, and 1,2-cyclohexyldiamine. The aldehyde compound or ketone compound containing a hydroxyl group is selected from at least one of p-hydroxybenzaldehyde, 1,3-dihydroxyacetone, butanolaldehyde, hydroxyacetone, 2-hydroxybenzophenone, and hydroxypropiophenone.

[0060] In some embodiments, the compound of the structure shown in formula (1) includes at least one of CH3CH(-HO)CH2CH=N-(CH2)2-N=CHCH2CH(-OH)CH3 and CH3CH(-HO)CH2CH=N-(CH2)3-N=CHCH2CH(-OH)CH3. They are modified resins prepared by reacting ethylenediamine or propylenediamine with 3-hydroxybutyraldehyde.

[0061] In some embodiments, the compound of the structure shown in formula (1) includes at least one of (HOCH2)2CH=N-(CH2)2-N=CH(CH2OH)2 and (HOCH2)2CH=N-(CH2)3-N=CH(CH2OH)2. They are modified resins obtained by reacting ethylenediamine and propylenediamine with 1,3-dihydroxyacetone, respectively.

[0062] In some embodiments of the present application, the compound of the structure shown in formula (1) includes CH3CH(-HO)CH2CH=N-Ph-N=CHCH2CH(-OH)CH3, which is a modified resin obtained by the reaction of phenylenediamine and 3-hydroxybutyraldehyde, wherein Ph is a phenylene group.

[0063] In some embodiments, the compound of the structure shown in formula (1) includes (HOCH2)2C=N-Ph-N=C(CH2OH)2, which is a modified resin obtained by the reaction of phenylenediamine and 1,3-dihydroxyacetone, wherein Ph is a phenylene group.

[0064] It can be understood that the compound having the structure shown in formula (1) can be a combination of several compounds having the above structural formula.

[0065] In a second aspect, the present application provides a method for preparing a modified resin, comprising:

[0066] Provide a compound represented by formula (2):

[0067]

[0068] In formula (2), R1 is selected from C1-C10 alkylene, C6-C10 arylene, C3-C8 cycloalkylene;

[0069] Provide a compound represented by formula (3):

[0070]

[0071] In formula (3), R2 is selected from H, C1-C6 alkyl, aryl, C1-C6 hydroxyalkyl; R3 is selected from C1-C6 alkylene, arylene, and R3 is connected to a hydroxyl group;

[0072] The compounds represented by formula (2) and formula (3) are reacted at a molar ratio of (0.45-0.5):1 to obtain a compound represented by formula (1):

[0073]

[0074] In formula (1), R1 is selected from C1-C10 alkylene, C6-C10 arylene, C3-C8 cycloalkylene; R2 is selected from H, C1-C6 alkyl, aryl, C1-C6 hydroxyalkyl; R3 is selected from C1-C6 alkylene and arylene, and R3 is connected to a hydroxyl group.

[0075] The modified resin of the embodiment of the present application is synthesized from an aldehyde compound containing a hydroxyl group or a ketone compound containing a hydroxyl group and a diamine. In the preparation process of the polyurethane waterproof coating, the modified resin acts as a lipid hard segment of the polyurethane resin and is embedded in the polyurethane resin to improve the performance of the polyurethane coating and reduce the influence of small molecule plasticizers on the film performance of the polyurethane coating. At the same time, in the hydrolysis process of the modified resin, the ketone compound containing a hydroxyl group or the aldehyde compound containing a hydroxyl group used as a sealing agent is embedded in the polyurethane resin as a hard segment and will not volatilize, effectively reducing volatile organic matter.

[0076] In the embodiments of the present application, the compounds represented by formula (2) and formula (3) undergo the following reaction:

[0077]

[0078] In reaction formula (6), R1 is selected from C1-C10 alkylene, C6-C10 arylene, C3-C8 cycloalkylene; R2 is selected from H, C1-C6 alkyl, aryl, C1-C6 hydroxyalkyl; R3 is selected from C1-C6 alkylene, arylene, and R3 is connected to a hydroxyl group.

[0079] In an embodiment of the present application, the compounds of the structures shown in formula (2) and formula (3) are reacted at a molar ratio of (0.45-0.5):1 at 100°C-130°C, and inert gas is charged for protection, and the modified resin of the structure shown in formula (1) is prepared by reflux dehydration. In some embodiments, the compound shown in formula (3) is in excess of the compound shown in formula (2) so that the diamine is fully reacted to obtain the modified resin of the structure shown in formula (1).

[0080] In some embodiments, the diamine compound of the structure shown in formula (2) is selected from ethylenediamine, propylenediamine, hexamethylenediamine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, trans-cyclopropane-1,2-diamine, 1,1-cyclobutanedimethylamine, 1,3-cyclobutanediamine, 1,3-cyclopentanediamine, 1,4-cyclohexyldiamine, 1,2-cyclohexyldiamine or a combination thereof. The hydroxyl-containing aldehyde compound and / or hydroxyl-containing aldehyde compound shown in formula (3) is selected from p-hydroxybenzaldehyde, 1,3-dihydroxyacetone, butanolaldehyde, 2-hydroxybenzophenone, hydroxypropiophenone or a combination thereof.

[0081] In some embodiments, the molar ratio of the structural compounds represented by formula (2) and formula (3) is (0.47-0.49): 1. The hydroxypropiophenone can be selected from 2-hydroxy-1-phenylpropiophenone, 3-hydroxy-1-phenylpropiophenone, or a combination of the two.

[0082] In the embodiments of the present application, since R2 in formula (1) can be a hydroxyalkyl group, the hydroxyalkyl group can react with the prepolymer prepared from diisocyanate and polyether polyol to form a cross-linked structure, thereby improving the mechanical properties of the coating film. In addition, the polyether triol contains one more hydroxyl group than the polyether diol, and can react with diisocyanate to further form a mutually cross-linked network structure in the coating film, thereby improving the mechanical properties of the coating film.

[0083] In a third aspect, an embodiment of the present application provides a self-crosslinking polyurethane resin, which includes a compound having a structure shown in formula (5):

[0084]

[0085] In formula 5, R1 is selected from C1-C10 alkylene, C6-C10 arylene, C3-C8 cycloalkylene; R2 is selected from H, C1-C6 alkyl, aryl, C1-C6 hydroxyalkyl; R3 is selected from C1-C6 alkylene and arylene, and R is a prepolymer group terminated with -NCO group prepared from diisocyanate and polyol, wherein the prepolymer is prepared from diisocyanate and polyol in a ratio of -NCO to -OH with a molar ratio of 1.5 to 2.5.

[0086] In the embodiments of the present application, the raw materials for preparing the compound of the structure shown in formula (5) include the compound of the structure shown in formula (1) above, and the compound of the structure shown in formula (4):

[0087]

[0088] In formula (4), R is a prepolymer group terminated with -NCO groups prepared from diisocyanate and polyol; wherein the ratio of -NCO in formula (4) to -OH in formula (1) is in the range of 1.5 to 2.5.

[0089] For example, the molar ratio of -NCO to -OH in the diisocyanate and polyol used to prepare the prepolymer of formula (4) may be 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, or 2.5.

[0090] The self-crosslinking polyurethane resin of the embodiment of the present application is prepared from a traditional -NCO group-terminated prepolymer and a modified resin, and the modified resin is synthesized by reacting an aldehyde compound containing a hydroxyl group or a ketone compound containing a hydroxyl group and a diamine. Compared with the traditional latent curing agent, the modified resin contains two hydroxyl groups with active hydrogen in the synthesis process of the polyurethane waterproof coating, and acts as a lipid hard segment of the polyurethane resin and is embedded in the polyurethane resin. Improve the performance of the coating and reduce the influence of small molecule plasticizers on the performance of the coating film. At the same time, the -NCO group in the coating preferentially reacts with the hydroxyl group contained in the hydrolyzate of the modified resin, reduces the reaction with moisture in the air, prevents the generation of CO2, and can effectively prevent the coating film from producing pores.

[0091] In a fourth aspect, the present application provides a method for preparing a self-crosslinking polyurethane resin, comprising reacting a compound having a structure shown in formula (1) and a compound having a structure shown in formula (4) in a molar ratio of 1:(2 to 4.5) to prepare a self-crosslinking polyurethane resin.

[0092] Illustratively, the molar ratio of the compound of the structure represented by formula (1) to the compound of the structure represented by formula (4) may be 1:2.1, 1:2.3, 1:2.4, 1:2.5, 1:2.7, 1:2.8, 1:2.9, 1:3.0, 1:3.2, 1:3.3, 1:3.5, 1:3.6, 1:3.8, 1:4.0, 1:4.1, 1:4.2, 1:4.4.

[0093] In some embodiments of the present application, a compound having a structure represented by formula (1) and a compound having a structure represented by formula (4) are reacted at a molar ratio of 2 to 4.5 at 70° C. to 80° C. to prepare a self-crosslinking polyurethane resin having a structure represented by formula (5).

[0094] In the embodiments of the present application, when the compound of the structure represented by formula (4) and the compound of the structure represented by formula (1) react at a molar ratio of 2:1, the compound of the structure represented by formula (4) and the compound of the structure represented by formula (1) undergo the following reaction:

[0095]

[0096] (7)

[0097] In reaction formula (7), R1 is selected from C1-C10 alkylene, C6-C10 arylene, C3-C8 cycloalkylene; R2 is selected from H, C1-C6 alkyl, aryl, C1-C6 hydroxyalkyl; R3 is selected from C1-C6 alkylene and arylene, and R is a -NCO-terminated prepolymer group prepared from diisocyanate and polyol, wherein the prepolymer is prepared from diisocyanate and polyol at a molar ratio of -NCO to -OH of 1.7 to 2.3.

[0098] In the embodiments of the present application, when R2 is a hydroxyalkyl group of C1 to C6, the compound of the structure shown in formula (4) can react with the hydroxyl group contained in R2. The compound of the structure shown in formula (4) can be located on the same side of the R1 group, such as grafted to the left or right side of the R1 group, or grafted to both the left and right sides of the R1 group, so that the prepolymer represented by R and the compound of the structure shown in formula (1) can cross-link to form a self-cross-linking polyurethane resin, thereby improving the physical and mechanical properties of the self-cross-linking polyurethane resin.

[0099] In the embodiments of the present application, the diisocyanate used to prepare the prepolymer represented by R is selected from one or more of hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, diphenylmethane diisocyanate (MDI), and toluene diisocyanate, and the polyol is a polyether diol or a polyether triol, or a mixture of a polyether diol and a polyether triol, and the molecular weight of the polyether diol and the polyether triol are both 1000 to 5000.

[0100] In the embodiments of the present application, the self-crosslinking polyurethane resin of the structure shown in formula (5) can be used to prepare a polyurethane waterproof coating. It can be obtained by pre-mixing polyether diol, polyether triol and diisocyanate as raw materials in the process of forming the coating. It is understood that in order to improve the performance of some polyurethane coatings, the self-crosslinking polyurethane resin can also be added to the polyurethane waterproof coating as a raw material component.

[0101] In the process of using the self-crosslinking polyurethane resin to prepare the polyurethane waterproof coating of the present application, or in the process of preparing other polyurethane waterproof coatings, before adding or forming the self-crosslinking polyurethane resin, the polyether diol, polyether triol, epoxy resin, plasticizer, pigment filler, dispersant, and defoamer components used to prepare the coating must be dehydrated in advance to reduce the impact of moisture on the coating performance.

[0102] In the fifth aspect, the embodiments of the present application provide a one-component solvent-free polyurethane waterproof coating, which is calculated by weight and includes: 40 to 70 parts of polyether diol; 30 to 50 parts of polyether triol; 70 to 120 parts of plasticizer; 10 to 20 parts of epoxy resin; 140 to 220 parts of pigments and fillers; 0.1 to 0.5 parts of dispersant; 1 to 2.5 parts of defoaming agent; 20 to 30 parts of diisocyanate; 0.5 to 1.5 parts of catalyst; and 10 to 18 parts of modified resin, wherein the modified resin is prepared by reacting a diamine compound with a hydroxyl-containing aldehyde compound and / or a hydroxyl-containing aldehyde compound.

[0103] The one-component solvent-free polyurethane waterproof coating of the embodiment of the present application is prepared by introducing a modified resin, a diisocyanate, and a polyether diol and a polyether triol to react to prepare a polyurethane waterproof coating containing a self-crosslinking polyurethane resin, and the modified resin in the self-crosslinking polyurethane resin is used as a lipid hard segment of the polyurethane resin to be embedded in the polyurethane resin to improve the coating performance and reduce the influence of small molecule plasticizers on the coating film performance. At the same time, the hydroxyl-containing aldehyde compound or hydroxyl-containing ketone compound generated during the hydrolysis of the modified resin can be embedded in the polyurethane resin as a hard segment and will not volatilize.

[0104] In some embodiments of the present application, the modified resin may be the aforementioned modified resin.

[0105] In some embodiments, the molecular weight of the polyether diol and the polyether triol is 1,000 to 5,000.

[0106] In some embodiments of the present application, the plasticizer is selected from chlorinated paraffins, citrate esters, phthalates, trioctyl phosphate or a combination thereof.

[0107] In some embodiments of the present application, the epoxy resin is selected from bisphenol A epoxy resin, bisphenol F epoxy resin or a combination thereof. For example, the epoxy resin can be selected from one or more of CYD-128, CYD-134, CYD-127, CYD-115, and bisphenol F diglycidyl ether.

[0108] In some embodiments of the present application, the chlorinated paraffins may be selected from 52#, 54#, 56#, 58#, 60#, 62#, 68# or a combination thereof.

[0109] In some embodiments of the present application, the citrate esters are selected from tributyl citrate, acetyl tributyl citrate or a combination thereof.

[0110] In some embodiments, the phthalates are selected from phthalic acid esters, di(2-ethylhexyl) phthalate, dibutyl phthalate, dioctyl phthalate, or combinations thereof.

[0111] In some embodiments of the present application, the filler is selected from nano calcium carbonate, talc, fumed silica, barium sulfate, heavy calcium, light calcium, kaolin, carbon black, red iron oxide, titanium dioxide, yellow iron oxide, composite emerald green or a combination thereof. The particle size of nano calcium carbonate, talc, fumed silica, barium sulfate, heavy calcium, light calcium and kaolin is 800 mesh to 3000 mesh.

[0112] In some embodiments of the present application, the dispersant is selected from a nonionic dispersant or an anionic dispersant or a combination thereof.

[0113] In some embodiments of the present application, the nonionic dispersant is selected from nano-scale superdispersant Disuper S18, PX4522, PU4020 or a combination thereof. Anionic dispersants are selected from BYK-110, BYK-052N, FA4644, FA4643, FA464 or a combination thereof.

[0114] In some embodiments, the defoamer is selected from a silicone defoamer, a mineral oil defoamer, or a combination thereof. Exemplarily, the defoamer is selected from YRXP-07B, YRXP-02, BYK-1786, BYK-8800, BYK-052N, or a combination thereof. YRXP-07B and YRXP-02 can be purchased from Guangzhou Yourun Synthetic Materials Co., Ltd. BYK-1786, BYK-8800, and BYK-052N can be purchased from BYK Chemical.

[0115] In some embodiments of the present application, the diisocyanate is selected from one or more of hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, diphenylmethane diisocyanate (MDI), and toluene diisocyanate.

[0116] In some embodiments of the present application, the catalyst is selected from dibutyltin dilaurate, stannous octoate, lead isooctanoate, bismuth isooctanoate, or a combination thereof.

[0117] In a sixth aspect, the present application provides a method for preparing a one-component solvent-free polyurethane waterproof coating, comprising: dispersing and mixing polyether diol, polyether triol, plasticizer, epoxy resin, pigment, dispersant, and defoamer to obtain a first mixture; adding diisocyanate and a catalyst to the first mixture to obtain a second reaction mixture; adding a modified resin to the second reaction mixture to obtain a one-component solvent-free polyurethane waterproof coating.

[0118] In some embodiments of the present application, the temperature of the dispersion and mixing of polyether diol, polyether triol, plasticizer, epoxy resin, pigment filler, dispersant and defoamer is controlled at 100°C to 120°C, and a dehydration reaction is carried out under vacuum conditions to obtain a first mixture.

[0119] In some embodiments of the present application, before adding diisocyanate and catalyst to the first mixture to prepare the second reaction mixture, the temperature of the first mixture needs to be cooled to 70° C. to 80° C., so that the diisocyanate and the polyether diol and polyether triol react to form a prepolymer terminated by -NCO groups and having a structure as shown in formula (4).

[0120] In some embodiments of the present application, the step of adding a modified resin to the second reaction mixture requires controlling the temperature of the second reaction mixture at 70°C to 80°C before adding the modified resin and reacting for 2 to 3 hours; then continuing to cool to 50°C to 60°C and discharging under the protection of an inert gas to prepare a one-component solvent-free polyurethane waterproof coating. Adding a modified resin to the second reaction mixture allows the modified resin to react with the prepolymer of the structure shown in formula (4) to obtain a self-crosslinking polyurethane resin of the structure shown in formula (5), thereby improving the physical properties of the coating film, while reducing the VOC volatilization of the one-component solvent-free polyurethane waterproof coating, and preventing the coating film from generating pores. Among them, the inert gas can be selected from helium, argon, and nitrogen. Among them, nitrogen is preferably used as the inert gas.

[0121] Example

[0122] The following are the models / brands of some raw materials used in the examples and comparative examples or their available sources: Polyether polyol: polyether diol, DL-2000D, Shandong Bluestar Dongda Co., Ltd.; trifunctional polyether polyol, EP330N, Shandong Bluestar Dongda Co., Ltd.

[0123] The pigments and fillers include: 800 mesh heavy calcium filler and 1250 mesh talcum powder; the pigment is prepared from 0.2 parts of carbon black and 3 parts of composite emerald green.

[0124] Plasticizer: 52# chlorinated paraffin, acetyl tributyl citrate. Epoxy resin is bisphenol A type epoxy resin: CYD-128, purchased from Baling Petrochemical. Catalyst: T12 organic tin catalyst (dibutyltin dilaurate). Dispersant: DisuperS18, purchased from Guangzhou Core New Material Technology Co., Ltd. Defoamer: BYK-052N.

[0125] Examples 1-3

[0126] Preparation of modified resin 1

[0127] Ethylene diamine and 3-hydroxybutyraldehyde were mixed in a molar ratio of 0.98:2 and added to a reaction container. The temperature was raised to 100° C., nitrogen was introduced for protection, and refluxed for dehydration reaction for 5 hours to obtain a modified resin 1.

[0128] Example 1

[0129] Preparation of solvent-free polyurethane waterproof coating

[0130] A. According to Table 1, add polyether diol DL-2000D, polyether triol DP330N, plasticizer 52# chlorinated paraffin and acetyl tributyl citrate, CYD-128 epoxy resin, pigment filler (a mixture of heavy calcium and talcum powder, carbon black and composite emerald green), dispersant DisuperS18, defoamer BYK-052N into a reaction vessel, stir and heat to 105°C ± 3°C, and dehydrate and react for 2 hours under a vacuum degree of -0.1MPa;

[0131] B. After dehydration, cool the product to 75℃~80℃, add diisocyanate and organic system catalyst T12, and then heat to 80℃±2℃ for 4 hours;

[0132] C. Control the temperature at 75°C ± 2°C, add the homemade modified resin 1, and continue the reaction for 2 hours;

[0133] D. Cool down to 58°C ± 2°C, discharge the material under nitrogen protection, and obtain a one-component solvent-free polyurethane waterproof coating.

[0134] Example 2

[0135] Preparation of solvent-free polyurethane waterproof coating

[0136] The difference between the solvent-free polyurethane waterproof coating of Example 2 and the solvent-free polyurethane waterproof coating of Example 1 is that the amount of the modified resin 1 used in Example 3 is 15 parts by weight.

[0137] Example 3

[0138] Preparation of solvent-free polyurethane waterproof coating

[0139] The difference between the solvent-free polyurethane waterproof coating of Example 3 and the solvent-free polyurethane waterproof coating of Example 1 is that the amount of the modified resin 1 used in Example 3 is 18 parts by weight.

[0140] Embodiment 4-6

[0141] Preparation of modified resin 2

[0142] Ethylene diamine and 1,3-dihydroxyacetone were mixed in a molar ratio of 0.98:2 and added to a reaction container. The temperature was raised to 100° C., nitrogen was introduced for protection, and refluxed for dehydration reaction for 5 hours to obtain modified resin 2.

[0143] Example 4

[0144] Preparation of solvent-free polyurethane waterproof coating

[0145] A. According to Table 1, add polyether diol DL-2000D, polyether triol DP330N, plasticizer 52# chlorinated paraffin and acetyl tributyl citrate, CYD-128 epoxy resin, pigment filler (a mixture of heavy calcium and talcum powder, carbon black and composite emerald green), dispersant DisuperS18, defoamer BYK-052N into a reaction vessel, stir and heat to 105±3°C, and dehydrate and react for 3 hours under a vacuum degree of -0.1MPa;

[0146] B. After dehydration, cool the product to 75℃~80℃, add diisocyanate and organic system catalyst T12, and then heat to 80℃±2℃ for 4 hours;

[0147] C. Control the temperature at 75°C ± 2°C, add the self-made modified resin 2, and continue the reaction for 2 hours;

[0148] D. Cooling to 58° C.±2° C., discharging under nitrogen protection, and obtaining the one-component solvent-free polyurethane waterproof coating of Example 4.

[0149] Example 5

[0150] The difference between the solvent-free polyurethane waterproof coating of Example 5 and the solvent-free polyurethane waterproof coating of Example 4 is that the amount of the modified resin 2 used in Example 5 is 15 parts by weight.

[0151] Example 6

[0152] The difference between the solvent-free polyurethane waterproof coating of Example 6 and the solvent-free polyurethane waterproof coating of Example 4 is that the amount of the modified resin 2 used in Example 6 is 18 parts by weight.

[0153] Comparative Example 1

[0154] The one-component solvent-free polyurethane waterproof coating composition of Comparative Example 1, as shown in Table 1, uses a latent curing agent with a commercial brand number of WL-1031 purchased from Guangzhou Longchi New Material Technology Co., Ltd., and the other components are the same as those in Example 1.

[0155] Comparative Example 2

[0156] The one-component solvent-free polyurethane waterproof coating composition of Comparative Example 2 is shown in Table 1, and is different from Example 1 in that the amount of modified resin 1 used is 7 parts by weight.

[0157] Comparative Example 3

[0158] The one-component solvent-free polyurethane waterproof coating composition of Comparative Example 2 is shown in Table 1, and is different from Example 1 in that the amount of modified resin 1 used is 21 parts by weight.

[0159] Comparative Example 4

[0160] Comparative Example 4 uses a commercially available solvent-free, environment-friendly polyurethane waterproof coating of model KS-900.

[0161]

[0162] Test Section

[0163] The waterproof coatings prepared in Examples 1-6 and Comparative Examples 1-4, as well as commercially available solvent-free polyurethane waterproof coatings were tested for elongation at break, tensile strength, tear strength, and VOC content using the test methods of GB / T 16777-2008, GB / T 19250-2013, and JC 1066-2008. The test results are shown in Table 2 below:

[0164] Table 2

[0165]

[0166] It can be seen from Table 2 above that compared with the traditional commercially available polyurethane waterproof coating product of Comparative Example 1, the solvent-free polyurethane waterproof coating provided by the present application, based on the commercially available polyurethane waterproof coating of Comparative Example 4, has a tensile strength increased by more than 9.89% (calculated based on Example 3), a tear strength increased by more than 14.11% (calculated based on Example 3), and an elongation at break increased by more than 13.92% (calculated based on Example 1). It can be seen that the tensile strength, tear strength, and elongation at break are all improved, and the VOC content is lower, indicating that the modified resin of the embodiment of the present application can make the one-component solvent-free polyurethane waterproof coating have better physical and mechanical properties, and have a lower VOC volatility. At the same time, by comparing the test data of the polyurethane waterproof coatings of Examples 1-3 and Comparative Examples 2 and 3, it can be concluded that excessive or insufficient modified resin affects the physical properties of the coating. If the amount of modified resin is too little, some -NCO groups react with water vapor, affecting the physical properties of the coating. Among them, if the amount of modified resin is too much, the molecular weight of the polyurethane resin after curing is too small, and the tensile strength, elongation at break and tear strength of the coating are all reduced, resulting in reduced coating performance. If the content of modified resin is too much, the coating is easy to solidify, although the elongation at break of the coating film will increase, it will also cause the tensile strength and tear strength of the coating to decrease, both of which refer to the overall reduction of coating performance.

[0167] The above is only a specific implementation method of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application.

Claims

1. A one-component solvent-free polyurethane waterproof coating, characterized in that: According to weight parts, it includes the following raw materials: Polyether diol, 40-70 parts; Polyether triol, 30-50 parts; Plasticizer, 70-120 parts; Epoxy resin, 10-20 parts; Pigments and fillers: 140-220 parts; Dispersant, 0.1-0.5 parts; Defoaming agent, 1 to 2.5 parts; Diisocyanate, 20-30 parts; Catalyst, 0.5-1.5 parts; Modified resin, 10-18 parts; the modified resin is prepared by reacting a diamine compound with an aldehyde compound containing a hydroxyl group and / or an aldehyde compound containing a hydroxyl group.

2. The one-component solvent-free polyurethane waterproof coating according to claim 1, characterized in that: The molar ratio of the diamine compound to the hydroxyl-containing aldehyde compound and / or the hydroxyl-containing aldehyde compound is (0.45-0.5):

1.

3. The one-component solvent-free polyurethane waterproof coating according to claim 1, characterized in that: The modified resin includes a compound shown in the following structural formula: In formula (1), R1 is selected from C1-C10 alkylene, C6-C10 arylene, C3-C8 cycloalkylene; R2 is selected from hydrogen atom, C1-C6 alkyl, aryl, C1-C6 hydroxyalkyl; R3 is selected from C1-C6 alkylene, arylene, and R3 is connected to a hydroxyl group.

4. The one-component solvent-free polyurethane waterproof coating according to claim 3, characterized in that: The modified resin is obtained according to the following preparation steps: Provide a compound represented by formula (2): In formula (2), R1 is selected from C1-C10 alkylene, C6-C10 arylene, C3-C8 cycloalkylene; Provide a compound represented by formula (3): In formula (3), R2 is selected from a hydrogen atom, a C1-C6 alkyl group, an aryl group, and a C1-C6 hydroxyalkyl group; R3 is selected from a C1-C6 alkylene group and an arylene group, and R3 is connected to a hydroxyl group; The compounds represented by formula (2) and formula (3) are reacted at a molar ratio of (0.45-0.5):1 to obtain a compound represented by formula (1): In formula (1), R1 is selected from C1-C10 alkylene, C6-C10 arylene, C3-C8 cycloalkylene; R2 is selected from hydrogen atom, C1-C6 alkyl, aryl, C1-C6 hydroxyalkyl; R3 is selected from C1-C6 alkylene and arylene, and R3 is connected to a hydroxyl group.

5. The one-component solvent-free polyurethane waterproof coating according to claim 4, characterized in that: Meet at least one of the following requirements: The diamine compound of the structure represented by formula (2) is selected from ethylenediamine, propylenediamine, hexamethylenediamine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, trans-cyclopropane-1,2-diamine, 1,1-cyclobutanedimethylamine, 1,3-cyclobutanediamine, 1,3-cyclopentanediamine, 1,4-cyclohexyldiamine, 1,2-cyclohexyldiamine or a combination thereof; The hydroxyl-containing aldehyde compound represented by formula (3) and / or the hydroxyl-containing aldehyde compound is selected from p-hydroxybenzaldehyde, 1,3-dihydroxyacetone, butanolaldehyde, hydroxyacetone, hydroxybenzophenone, hydroxypropiophenone or a combination thereof.

6. The one-component solvent-free polyurethane waterproof coating according to claim 3, characterized in that: The modified resin includes at least one of CH3CH(-HO)CH2CH=N-(CH2)2-N=CHCH2CH(-OH)CH3, CH3CH(-HO)CH2CH=N-(CH2)3-N=CHCH2CH(-OH)CH3, (HOCH2)2CH=N-(CH2)2-N=CH(CH2OH)2, (HOCH2)2CH=N-(CH2)3-N=CH(CH2OH)2, CH3CH(-HO)CH2CH=N-Ph-N=CHCH2CH(-OH)CH3, and (HOCH2)2C=N-Ph-N=C(CH2OH)2, wherein Ph is phenylene.

7. The one-component solvent-free polyurethane waterproof coating according to any one of claims 1 to 6, characterized in that: Meet at least one of the following requirements: (1) The molecular weights of the polyether diol and the polyether triol are both 1000 to 5000; (2) The plasticizer is selected from chlorinated paraffins, citrate esters, phthalates, trioctyl phosphate or a combination thereof; (3) the epoxy resin is selected from bisphenol A epoxy resin, bisphenol F epoxy resin or a combination thereof; (4) The pigment filler is selected from nano calcium carbonate, talc, fumed silica, barium sulfate, heavy calcium, light calcium, kaolin, carbon black, red iron oxide, titanium dioxide, yellow iron oxide, composite emerald green or a combination thereof; (5) The dispersant is selected from a nonionic dispersant or an anionic dispersant or a combination thereof; (6) The defoamer is selected from silicone defoamers, mineral oil defoamers or a combination thereof; (7) The diisocyanate is selected from one or more of hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, diphenylmethane diisocyanate, and toluene diisocyanate; (8) The catalyst is selected from dibutyltin dilaurate, stannous octoate, lead isooctanoate, bismuth isooctanoate or a combination thereof.

8. The one-component solvent-free polyurethane waterproof coating according to claim 7, characterized in that: Meet any one of the following requirements: The particle sizes of the nano calcium carbonate, talcum powder, fumed silica, barium sulfate, heavy calcium carbonate, light calcium carbonate and kaolin are 800-3000 meshes; The nonionic dispersant is selected from nano-scale superdispersant Disuper S18, Ultra PX4522, PU4020 or a combination thereof; The anionic dispersant is selected from BYK-110, BYK-052N, FA4644, FA4643, FA464 or a combination thereof; The defoaming agent is selected from YRXP-07B, YRXP-02, BYK-1786, BYK-8800, BYK-052N or a combination thereof.

9. A method for preparing a one-component solvent-free polyurethane waterproof coating according to any one of claims 1 to 8, characterized in that: include: Dispersing and mixing polyether diol, polyether triol, plasticizer, epoxy resin, pigment, filler, dispersant and defoamer to prepare a first mixture; adding diisocyanate and a catalyst to the first mixture to prepare a second reaction mixture; The modified resin is added to the second reaction mixture to prepare a one-component solvent-free polyurethane waterproof coating.

10. A method for preparing a self-crosslinking polyurethane resin, characterized in that: A modified resin is provided, wherein the modified resin is obtained according to the following preparation steps: Provide a compound represented by formula (2): In formula (2), R1 is selected from C1-C10 alkylene, C6-C10 arylene, C3-C8 cycloalkylene; Provide a compound represented by formula (3): In formula (3), R2 is selected from a hydrogen atom, a C1-C6 alkyl group, an aryl group, and a C1-C6 hydroxyalkyl group; R3 is selected from a C1-C6 alkylene group and an arylene group, and R3 is connected to a hydroxyl group; The compounds represented by formula (2) and formula (3) are reacted at a molar ratio of (0.45-0.5):1 to obtain a compound represented by formula (1): In formula (1), R1 is selected from C1-C10 alkylene, C6-C10 arylene, C3-C8 cycloalkylene; R2 is selected from hydrogen, C1-C6 alkyl, aryl, C1-C6 hydroxyalkyl; R3 is selected from C1-C6 alkylene and arylene, and R3 is connected to a hydroxyl group; and, Provide a compound of the structure shown in formula (4): In formula (4), R is a prepolymer group terminated by -NCO groups prepared from diisocyanate and polyol; wherein the prepolymer is prepared from the diisocyanate and polyol in a ratio of -NCO to -OH of 1.5 to 2.5; The compound with the structure shown in formula (4) is reacted with the compound with the structure shown in formula (1) under the action of a catalyst to prepare a self-crosslinking polyurethane resin.

11. The method for preparing a self-crosslinking polyurethane resin according to claim 10, characterized in that: Meet any of the following requirements: The diisocyanate is selected from hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate or a combination thereof; The polyol is selected from polyether diol and / or polyether triol, and the molecular weight of the polyol is 1000-5000.

12. A self-crosslinking polyurethane resin, characterized in that: The method for preparing a self-crosslinking polyurethane resin according to claim 10 or 11, wherein the self-crosslinking polyurethane resin comprises a structure represented by formula (5): In formula (5), R1 is selected from C1-C10 alkylene, C6-C10 arylene, C3-C8 cycloalkylene; R2 is selected from H, C1-C6 alkyl, aryl, C1-C6 hydroxyalkyl; R3 is selected from C1-C6 alkylene and arylene, and R is a -NCO-terminated prepolymer group prepared from diisocyanate and polyol, wherein the diisocyanate and polyol are prepared in a ratio of -NCO to -OH of 1.5 to 2.5 to prepare the prepolymer.

13. Use of the self-crosslinking polyurethane resin according to claim 12 in preparing a polyurethane waterproof coating.

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