A polyurethane white primer, its preparation method and application

Abstract

The application relates to the paint technology field, and provides a polyurethane white primer, a preparation method and application thereof. The polyurethane white primer comprises an A component and a B component; wherein the A component comprises soybean oil modified alkyd resin, castor oil modified alkyd resin, titanium white, a filler, an auxiliary agent and an A solvent; the B component comprises a B solvent, a dehydrating agent, an aliphatic isocyanate adduct curing agent and a toluene diisocyanate trimer curing agent. The polyurethane white primer provided by the application is compounded by taking the soybean oil modified alkyd resin and the castor oil modified alkyd resin as main film-forming substances, and is matched with the titanium white, the filler and the auxiliary agent, so that the hiding power, the fullness, the hardness and the flexibility of a coating film are further improved, the coating film has excellent coating effect, and the problems of cracking and falling off are not prone to occurring.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of coatings, and particularly relates to a polyurethane white primer and a preparation method and application thereof. BACKGROUND

[0002] With the gradual improvement of people's living standards, people pay more attention to the exquisite and environmental protection of house decoration in house construction, and the coating plate used in decoration in house construction is also more diversified with the improvement of people's living standards. Melamine board is outstanding in home decoration materials and favored by people due to its excellent properties of high acid resistance, alkali resistance, high temperature resistance and water resistance, and low price.

[0003] However, after the conventional white primer is coated on the melamine board, the paint film on the melamine board is prone to cracking and falling off due to the special material and high hardness of the melamine board, the board surface effect is not good enough, and the overall hardness and adhesion of the paint film need to be improved, thereby limiting the application of the melamine board. SUMMARY

[0004] The purpose of the present application is to provide a polyurethane white primer and a preparation method and application thereof, aiming to solve the problems of poor hardness, low adhesion and poor flexibility of the existing primer.

[0005] To achieve the above application purposes, the technical solutions adopted by the present application are as follows:

[0006] In a first aspect, the present application provides a polyurethane white primer, comprising component A and component B; wherein,

[0007] The component A comprises the following components in the following weight percentages, based on 100% of the total weight of the component A:

[0008]

[0009]

[0010] The component B comprises the following components in the following weight percentages, based on 100% of the total weight of the component B:

[0011]

[0012] In a second aspect, the present application provides a preparation method of a polyurethane white primer, comprising the following steps:

[0013] The polyurethane white primer provided in the first aspect of the present application provides component materials;

[0014] The soybean oil modified alkyd resin, castor oil modified alkyd resin, titanium dioxide, filler, auxiliary agent and A solvent are mixed and treated to obtain component A;

[0015] The B solvent, the dehydrating agent, the aliphatic isocyanate adduct curing agent and the toluene diisocyanate trimer curing agent are mixed to obtain a B component.

[0016] In a third aspect, the application provides an application of the polyurethane white primer in the board and wooden furniture.

[0017] The application has the following beneficial effects:

[0018] The polyurethane white primer provided by the first aspect of the application comprises an A component and a B component, wherein the A component is compounded by using a soybean oil modified alkyd resin and a castor oil modified alkyd resin as main film-forming substances. The soybean oil modified alkyd resin can effectively improve the fullness, flexibility and adhesion of the paint film. The use of the soybean oil modified alkyd resin in combination with the castor oil modified alkyd resin is conducive to improving the hardness, flexibility and adhesion of the paint film. The titanium white, fillers and auxiliary agents are used in combination to further improve the hiding power, fullness and hardness of the coating film, so that the coating film has excellent coating effect and is not prone to cracking and falling off. The B component is compounded by using an aliphatic isocyanate adduct curing agent and a toluene diisocyanate trimer curing agent. The B component has good compatibility with the A component, can effectively adjust the surface drying and real drying processes of the paint film, and makes the paint film have suitable drying performance, thereby endowing the paint film with high hardness, high flexibility, high adhesion and other properties.

[0019] The preparation method of the polyurethane white primer provided by the second aspect of the application comprises mixing and processing each raw material in the formula. The method is simple and easy to control, and can be used for the large-scale production of the polyurethane white primer to obtain a primer with good dispersibility and without flocculation.

[0020] The polyurethane white primer provided by the third aspect of the application can be used in the board and wooden furniture. The paint film formed after coating has high hardness, strong adhesion and good flexibility, so that the coating effect of the paint film is excellent and is not prone to cracking, falling off and collapse in the later period. DETAILED DESCRIPTION

[0021] In order to make the technical problems, technical solutions and beneficial effects of the application clearer, the application will be further described in detail below in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the application and not to limit the application.

[0022] In the application, the term "and / or" describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B, which can mean that A exists alone, A and B exist together, and B exists alone. Wherein A and B can be singular or plural. The character " / " generally represents an "or" relationship between the front and rear associated objects.

[0023] In this application, "at least one" means one or more, "multiple" means two or more. "At least one of the following" or similar expressions means any combination of these items, including a single item or any combination of multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can mean a, b, c, a-b (i.e. a and b), a-c, b-c, or a-b-c, where a, b, and c can be single or multiple.

[0024] It should be understood that the size of the sequence number of the above-mentioned processes in various embodiments of the present application does not mean the order of execution, and part or all of the steps can be executed in parallel or in sequence, and the execution order of the processes should be determined according to their functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0025] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0026] The weight of the related components mentioned in the specification of the embodiments of the present application can not only refer to the specific content of each component, but also represent the weight ratio relationship between each component, therefore, as long as the content of the related components in the specification of the embodiments of the present application is enlarged or reduced in proportion, it is within the scope disclosed in the specification of the embodiments of the present application. Specifically, the mass mentioned in the specification of the embodiments of the present application can be μg, mg, g, kg and other mass units commonly known in the chemical field.

[0027] The terms "first", "second" are only for the purpose of description, used to distinguish objects such as substances from each other, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. For example, without departing from the scope of the embodiments of the present application, the first XX can also be called the second XX, and similarly, the second XX can also be called the first XX. Therefore, the features limited by "first" and "second" can explicitly or implicitly include one or more of the features.

[0028] The first aspect of the embodiments of the present application provides a polyurethane white primer, which comprises component A and component B; wherein,

[0029] The component A comprises the following components in the following weight percentage, based on 100% of the total weight of the component A:

[0030]

[0031] The B component comprises the following components in the following weight percentages, based on 100% of the total weight of the B component:

[0032]

[0033] The polyurethane white primer provided in the first aspect of the application comprises an A component and a B component. The A component is compounded with a soybean oil modified alkyd resin and a castor oil modified alkyd resin as the main film-forming material. The soybean oil modified alkyd resin can effectively improve the fullness, flexibility and adhesion of the paint film. The use of the soybean oil modified alkyd resin in combination with the castor oil modified alkyd resin is conducive to improving the hardness, flexibility and adhesion of the paint film. The titanium dioxide, fillers and auxiliary agents are used in combination to further improve the hiding power, fullness and hardness of the coating film, so that the coating film has excellent coating effect and is not prone to cracking and falling off.

[0034] In some embodiments, the polyurethane white primer provided in the above of the application is stored separately when not in use, and the A component and the B component are mixed in proportion to obtain the polyurethane white primer when in use.

[0035] It can be understood that the soybean oil modified alkyd resin refers to a new alkyd resin formed by adding soybean oil to the alkyd resin in addition to fatty acid, polyol and phthalic anhydride (or isophthalic acid) and then performing chemical reaction.

[0036] In an exemplary embodiment, the soybean oil modified alkyd resin can be Guangdong Sanmu Chemical 3738-70 alkyd resin. The soybean oil modified alkyd resin has small particle size and good compatibility, and can effectively improve the fullness, flexibility and polishing performance of the paint film.

[0037] It can be understood that the castor oil modified alkyd resin refers to a new alkyd resin formed by adding castor oil to the alkyd resin in addition to fatty acid, polyol and phthalic anhydride (or isophthalic acid) and then performing chemical reaction.

[0038] In an exemplary embodiment, the castor oil modified alkyd resin can be at least one of Guangdong Jiangmen Paint Resin PJ6487 castor oil resin and Zhanchen Resin JD16-70 castor oil modified resin. These resins have good compatibility and can be uniformly mixed with other components without causing agglomeration, and can effectively improve the drying speed, fullness, leveling property and collapse performance of the paint film.

[0039] In the exemplary embodiment, the titanium white can be at least one of the rutile titanium white of DuPont, and the Longpeng R-996 titanium white. These titanium whites have good hiding power, high whiteness, and low oil absorption, and can effectively improve the hiding power, fullness, and adhesion of the paint film, so that the paint film has high gloss, good color retention, and other coating effects.

[0040] It can be understood that the aliphatic isocyanate adduct is obtained by chemical reaction of a plurality of aliphatic isocyanates.

[0041] In the exemplary embodiment, the toluene diisocyanate trimer curing agent can be at least one of Bayer L1451 and Bogao Chemical BG-450TB. These curing agents have good compatibility, can effectively improve the drying process of the paint film, make the paint film harden quickly, and can also adjust the flexibility and collapse performance of the paint film, and endow the paint film with high hardness, high adhesion, high flexibility, anti-collapse, and other properties.

[0042] In the exemplary embodiment, the mass content of the soybean oil modified alkyd resin can be a typical but non-limiting value of 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, etc.

[0043] In the exemplary embodiment, the mass content of the castor oil modified alkyd resin can be a typical but non-limiting value within 15%, 18%, 20%, 22%, 25%, etc.

[0044] In the exemplary embodiment, the mass content of the titanium white can be a typical but non-limiting value of 15%, 18%, 20%, 22%, 23%, 25%, etc.

[0045] In the exemplary embodiment, the mass content of the filler can be a typical but non-limiting value of 26%, 30%, 32%, 35%, 40%, 42%, 45%, 48%, etc.

[0046] In the exemplary embodiment, the mass content of the auxiliary agent can be a typical but non-limiting value of 1.2%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 5%, etc.

[0047] In the exemplary embodiment, the mass content of the A solvent can be a typical but non-limiting value of 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 8%, etc.

[0048] In the exemplary embodiment, the mass content of the B solvent can be a typical but non-limiting value of 35%, 36%, 37%, 38%, 39%, 40%, etc.

[0049] In the exemplary embodiment, the mass content of the dehydrating agent can be a typical but non-limiting value of 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, etc.

[0050] In the example, the mass content of the aliphatic isocyanate adduct curing agent can be typical but not limiting values ​​such as 40%, 41%, 42%, 43%, 44%, and 45%.

[0051] In the example, the mass content of the toluene diisocyanate trimer curing agent can be a typical but non-limiting value such as 15%, 16%, 17%, 18%, 19%, or 20%.

[0052] In some embodiments, the mass ratio of component A to component B is 100:40 to 50.

[0053] This application embodiment optimizes and controls the mass ratio of component A to component B, so that there are sufficient hydroxyl groups in component A to react with isocyanate groups (NCO) in component B to form a paint film with a three-dimensional cross-linked network structure, thereby giving the paint film high hardness, high adhesion, and high flexibility.

[0054] In the example, the mass ratio of component A to component B can be a typical but non-limiting ratio such as 100:40, 100:42, 100:45, 100:48, 100:50.

[0055] In some embodiments, the polyurethane white primer further includes component C, wherein the mass ratio of component A to component C is 100:10 to 20, and component C comprises the following components by weight percentage, based on 100% of the total weight of component C:

[0056] Propylene glycol methyl ether acetate 40%–45%

[0057] 30%–35% n-butyl acetate

[0058] Xylene 20%–30%.

[0059] In this embodiment, by adding component C, which can act as a diluent, the viscosity of the primer is effectively adjusted, thereby improving the primer's application performance and obtaining a paint film with excellent physicochemical and decorative properties.

[0060] In the examples, the mass ratio of component A to component C is a typical but not limiting ratio such as 100:10, 100:12, 100:51, 100:18, 100:20.

[0061] In the example, the mass content of propylene glycol methyl ether acetate in component C can be typical but not limiting values ​​such as 40%, 41%, 42%, 43%, 44%, and 45%.

[0062] In the example, the mass content of n-butyl acetate in component C can be a typical but non-limiting value such as 30%, 31%, 32%, 33%, 34%, or 35%.

[0063] In exemplary embodiments, the mass content of xylene in the C component can be 20%, 22%, 23%, 25%, 27%, 29%, 30%, etc., which are typical but non-limiting values.

[0064] In some embodiments, the hydroxyl value of the soybean oil modified alkyd resin is 110-130 mg KOH / g.

[0065] It can be understood that the hydroxyl value refers to the milligrams of potassium hydroxide corresponding to the hydroxyl groups in 1 g of sample.

[0066] By controlling the hydroxyl value of the soybean oil modified alkyd resin in the above range, the embodiments of the present application can provide an appropriate amount of hydroxyl active groups, which can be cross-linked and cured with the curing agent in the B component, the cross-linking density is high, and the hardness and adhesion of the paint film are increased.

[0067] In exemplary embodiments, the hydroxyl value of the soybean oil modified alkyd resin can be 110 mg KOH / g, 112 mg KOH / g, 115 mg KOH / g, 118 mg KOH / g, 120 mg KOH / g, 123 mg KOH / g, 125 mg KOH / g, 127 mg KOH / g, 130 mg KOH / g, etc., which are typical but non-limiting values.

[0068] In some embodiments, the solid content of the soybean oil modified alkyd resin is 65%-75%. The soybean oil modified alkyd resin has high solid content, so it can effectively improve the drying performance of the paint film, and after drying, a paint film with a three-dimensional cross-linking structure is formed, which gives the paint film high flexibility, hardness and adhesion.

[0069] In exemplary embodiments, the solid content of the soybean oil modified alkyd resin can be 65%, 68%, 70%, 72%, 75%, etc., which are typical but non-limiting values.

[0070] In some embodiments, the hydroxyl value of the castor oil modified alkyd resin is 130-140 mg KOH / g.

[0071] By controlling the hydroxyl value of the castor oil modified alkyd resin in the above range, the embodiments of the present application mean that the castor oil modified alkyd resin has high reactivity, can better participate in the cross-linking and curing reaction, and obtain a paint film with high cross-linking density, high hardness and strong adhesion. In exemplary embodiments, the hydroxyl value of the castor oil modified alkyd resin can be 130 mg KOH / g, 131 mg KOH / g, 132 mg KOH / g, 133 mg KOH / g, 134 mg KOH / g, 135 mg KOH / g, 136 mg KOH / g, 137 mg KOH / g, 138 mg KOH / g, 139 mg KOH / g, 140 mg KOH / g, etc., which are typical but non-limiting values.

[0072] In some embodiments, the solid content of the castor oil modified alkyd resin is 65% to 75%. The castor oil modified alkyd resin has a high solid content, and thus can effectively improve the drying performance of the paint film, and after drying, a paint film having a three-dimensional crosslinked structure is formed, imparting high flexibility, hardness, and adhesion to the paint film.

[0073] In some embodiments, the auxiliary agent includes at least one of a wetting agent, a defoaming agent, an anti-settling agent, and a leveling agent.

[0074] The embodiments of the present application can effectively improve the dispersion effect between the raw material components in the A component by adding auxiliary agents including wetting agents, defoaming agents, anti-settling agents, leveling agents, and the like, further improving the leveling, drying effect, and adhesion of the paint film.

[0075] In some embodiments, the auxiliary agent includes the following mass percentage components, based on 100% of the total weight of the A component:

[0076]

[0077]

[0078] By controlling the content of each component in the auxiliary agent, the A component has better workability, and further improves the fullness, hardness, adhesion, and collapse performance of the paint film.

[0079] For example, the mass content of the wetting agent in the A component can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, and the like, which are typical but not limiting values.

[0080] For example, the mass content of the defoaming agent in the A component can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, and the like, which are typical but not limiting values.

[0081] For example, the mass content of the anti-settling agent in the A component can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.5%, 1.8%, 2.0%, 2.2%, 2.5%, 2.8%, 3.0%, and the like, which are typical but not limiting values.

[0082] For example, the mass content of the leveling agent in the A component can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, and the like, which are typical but not limiting values.

[0083] In some embodiments, the wetting agent includes a high-molecular block copolymer containing a pigment-affinity group. The wetting agent has a high wetting dispersion effect, promoting uniform dispersion of each component in the A component, particularly facilitating stable dispersion of titanium dioxide in the A component system, while also improving the viscosity of the system and increasing the application performance of the primer. The wetting agent includes, for example but not limited to, BYK 110 from BYK, Germany.

[0084] In some embodiments, the defoaming agent includes a defoaming polysiloxane solution. The defoaming polysiloxane solution has good compatibility and good defoaming and antifoaming effects in the primer system. The defoaming agent includes, for example but not limited to, BYK-066N from BYK, Germany, and the like.

[0085] In some embodiments, the anti-settling agent includes fumed silica. The anti-settling agent can effectively improve the stability of the A component and the primer, particularly effectively improving the dispersion effect of titanium dioxide and fillers in the system, reducing the sedimentation of titanium dioxide and fillers in the system, thereby improving the storage stability of the paint film. The anti-settling agent includes, for example but not limited to, fumed silica R972 from Degussa.

[0086] In some embodiments, the leveling agent includes a fluorocarbon-containing polyacrylate leveling agent. The fluorocarbon-containing polyacrylate leveling agent can reduce the surface tension of the primer, so that the coating can self-level more quickly after being applied on the substrate after wetting, so that the paint film has higher fullness and adhesion. The leveling agent includes, for example but not limited to, BYK 358N from BYK, Germany, EFKA 3777 from Evonik, and the like.

[0087] In some embodiments, the filler includes zinc stearate and talc in a mass ratio of 1-3:25-45. The filler contains zinc stearate and talc in specific weight proportions, wherein the zinc stearate acts as a polishing aid to effectively improve the polishing performance and adhesion of the paint film, so that the paint film has higher hardness, adhesion, and good coating effect; the talc can effectively improve the filling and hiding power of the paint film, so that the paint film has higher fullness and hardness.

[0088] For example, the mass proportion of zinc stearate in the filler can be 1, 1.5, 2, 2.5, 3, and the like, which are typical but not limited values; the mass proportion of talc in the filler can be 25, 28, 30, 32, 35, 38, 40, 42, 45, and the like, which are typical but not limited values.

[0089] For example, the zinc stearate includes but is not limited to BT-1819 from Bolihe, Zhongshan, Guangdong.

[0090] For example, the talc includes but is not limited to AC-310 1250 mesh talc from Lanbiethe, Longsheng, Guangxi.

[0091] In some embodiments, the A solvent includes an ether ester solvent and an ester solvent in a mass ratio of 3-5:1-3. These solvents can effectively promote the uniform dispersion of each raw material component in the A component and form a uniform system, and are not prone to precipitation or flocculation.

[0092] For example, the mass ratio of the ether ester solvent in the A solvent can be 3, 3.5, 4, 4.5, 5, etc. typical but not limited values. The mass ratio of the ester solvent can be 1, 1.5, 2, 2.5, 3, etc. typical but not limited values.

[0093] For example, the ether ester solvent includes but is not limited to propylene glycol methyl ether acetate; the ester solvent includes but is not limited to n-butyl acetate.

[0094] In some embodiments, the B solvent includes n-butyl acetate. This solvent can make each raw material component in the B component uniformly dispersed therein, and is beneficial to improve the compatibility between the A component and the B component.

[0095] In some embodiments, the dehydrating agent includes at least one of Samsung Chemical BLD-100, TI from Bayer, Germany, and BF5 from GAB A, Germany. These dehydrating agents can quickly react with water in the system, thereby improving the storage period of the B component, so that the paint film has excellent coating effect.

[0096] The second aspect of the embodiments of the present application provides a preparation method of a polyurethane white primer, including the following steps:

[0097] Step S10, the polyurethane white primer according to the first aspect of the embodiments of the present application provides each component material;

[0098] Step S20, the soybean oil modified alkyd resin, the castor oil modified alkyd resin, the titanium dioxide, the filler, the auxiliary agent and the A solvent are mixed and treated to obtain the A component;

[0099] Step S30, the B solvent, the dehydrating agent, the aliphatic isocyanate adduct curing agent and the toluene diisocyanate trimer curing agent are mixed and treated to obtain the B component.

[0100] The preparation method of the polyurethane white primer provided by the second aspect of the embodiments of the present application mixes and processes each raw material in the formula, which is simple and easy to control, and can be used for the large-scale production of the polyurethane white primer to obtain a primer with good dispersibility and no flocculation.

[0101] In some embodiments, in step S10, the types and addition amounts of each component material of the polyurethane white primer are as described above, and are not repeated here in order to save space.

[0102] In some embodiments, the process of mixing the soybean oil modified alkyd resin, the castor oil modified alkyd resin, the titanium white, the filler, the auxiliary agent, and the A solvent in step S20 to obtain the A component comprises:

[0103] Step S21, the first mixing treatment of the soybean oil modified alkyd resin, the castor oil modified alkyd resin, the ether ester solvent, and the wetting agent to obtain a first mixture;

[0104] Step S22, the second mixing treatment of the first mixture with the defoaming agent, the titanium white, the anti-settling agent, the zinc stearate, and the talc to obtain a second mixture;

[0105] Step S23, the third mixing treatment of the second mixture with the leveling agent and the ester solvent to obtain the A component.

[0106] In some embodiments, in step S21, the first mixing treatment has a rotation speed of 600 rpm to 800 rpm and a time of 5 min to 8 min. Exemplarily, the rotation speed of the first mixing treatment can be 600 rpm, 650 rpm, 700 rpm, 750 rpm, 800 rpm, or the like typical but non-limiting value, and the time can be 5 min, 6 min, 7 min, 8 min, or the like typical but non-limiting value.

[0107] In some embodiments, in step S22, the second mixing treatment has a rotation speed of 1500 rpm to 2500 rpm and a time of 15 min to 25 min. Exemplarily, the rotation speed of the second mixing treatment can be 1500 rpm, 1600 rpm, 1800 rpm, 2000 rpm, 2200 rpm, 2500 rpm, or the like typical but non-limiting value, and the time can be 15 min, 18 min, 20 min, 22 min, 25 min, or the like typical but non-limiting value.

[0108] In some embodiments, in step S23, the third mixing treatment has a rotation speed of 600 rpm to 800 rpm and a time of 5 min to 10 min. Exemplarily, the rotation speed of the third mixing treatment can be 600 rpm, 650 rpm, 700 rpm, 750 rpm, 800 rpm, or the like typical but non-limiting value, and the time can be 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, or the like typical but non-limiting value.

[0109] In some embodiments, the process of mixing the B solvent, the dehydrating agent, the aliphatic isocyanate adduct curing agent, and the toluene diisocyanate trimer curing agent in step S30 to obtain the B component comprises:

[0110] Step S31, dispersing the dehydrating agent into the B solvent for dehydration treatment to obtain a third mixture;

[0111] Step S32, the third mixture is subjected to fourth mixing treatment with the aliphatic isocyanate adduct curing agent and the toluene diisocyanate trimer curing agent to obtain the B component.

[0112] In some embodiments, in step S31, the dehydration treatment is performed for 22-26 hours. For example, the dehydration treatment can be performed for 22 hours, 23 hours, 24 hours, 25 hours, 26 hours, or the like.

[0113] In some embodiments, in step S32, the fourth mixing treatment is performed at a speed of 600-800 rpm for 5-10 minutes. For example, the fourth mixing treatment can be performed at a speed of 600 rpm, 650 rpm, 700 rpm, 750 rpm, 800 rpm, or the like, and for 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, or the like.

[0114] In some embodiments, the polyurethane white primer provided in the above description is stored separately as the A component and the B component when not in use, and is mixed according to a ratio to obtain the polyurethane white primer when in use.

[0115] In some embodiments, the method for preparing the polyurethane white primer further comprises:

[0116] Step S40, the propylene glycol methyl ether acetate and the n-butyl acetate are subjected to fifth mixing treatment with the xylene to obtain the C component.

[0117] In some embodiments, in step S40, the fifth mixing treatment is performed at a speed of 300-500 rpm for 5-10 minutes. For example, the fifth mixing treatment can be performed at a speed of 300 rpm, 350 rpm, 400 rpm, 450 rpm, 500 rpm, or the like, and for 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, or the like.

[0118] In some embodiments, the polyurethane white primer provided in the above description is stored separately as the A component, the B component, and the C component when not in use, and is mixed according to a ratio to obtain the polyurethane white primer when in use.

[0119] The third aspect of the embodiments of the present application provides an application of the polyurethane white primer described above to a board and wooden furniture.

[0120] The polyurethane white primer provided in the third aspect of the embodiments of the present application can be used for board and wooden furniture, and the paint film formed after coating has high hardness, strong adhesion, good flexibility and other properties, so that the coating effect of the paint film is excellent, and problems such as cracking, peeling and collapse are less likely to occur in the later period.

[0121] Exemplarily, the board includes but is not limited to melamine board.

[0122] The following will be described in combination with specific embodiments.

[0123] The components and mass percentage contents of the A component are shown in Table 1.

[0124] Table 1 Components and weight percentage contents of the A component

[0125] The preparation method of the A component 1 includes the following steps:

[0126] Step S1, the ingredients and their weight percentage contents in Table 1 above are weighed respectively;

[0127] Step S2, the soybean oil modified alkyd resin, castor oil modified alkyd resin, ether ester solvent and wetting agent are added to the dispersion cylinder, and stirred at a speed of 700 rpm for 7 min to obtain a first mixture;

[0128] Step S3, the defoaming agent, titanium white, anti-settling agent, zinc stearate and talc are added to the first mixture, and stirred at a speed of 2000 rpm until the fineness is ≤60 μm to obtain a second mixture;

[0129] Step S4, the leveling agent and ester solvent are added to the second mixture, and stirred at a speed of 700 rpm for 8 min to obtain the A component 1.

[0130] The preparation method of the A component 2 is the same as that of the A component 1.

[0131] The preparation method of the A component 3 is the same as that of the A component 1.

[0132] The preparation method of the A component 3 is the same as that of the A component 1.

[0133] The components and weight percentage contents of the B component are shown in Table 2.

[0134] Table 2 Weight percentage contents of the B component

[0135]

[0136] The preparation method of the B component 1 includes the following steps:

[0137] Step S1, mix B solvent with dehydrating agent, and place for 24 h for dehydration treatment to obtain a third mixture;

[0138] Step S2, add the aliphatic isocyanate adduct curing agent and the toluene diisocyanate trimer curing agent into the third mixture, and stir at a speed of 600 rpm for 5 min to obtain B component 1.

[0139] The preparation method of B component 2 is the same as that of B component 1.

[0140] The preparation method of B component 3 is the same as that of B component 1.

[0141] The preparation method of B component 4 is the same as that of B component 1.

[0142] III. Components and weight percentage of D-B are shown in Table 3.

[0143] Table 3 Weight percentage of components of D-B

[0144]

[0145] The preparation method of D-B component 1 is the same as that of B component 1.

[0146] The preparation method of D-B component 2 is the same as that of B component 1.

[0147] The preparation method of D-B component 3 is the same as that of B component 1.

[0148] The preparation method of D-B component 4 is the same as that of B component 1.

[0149] IV. Components and weight percentage of C component are shown in Table 4.

[0150] Table 4 Weight percentage of components of C

[0151] Material C Component mass percentage content (%) Propylene glycol methyl ether acetate 40 n-Butyl acetate 35 Xylene 25 Total 100

[0152] The preparation method of C component comprises the following steps:

[0153] Step S1, add propylene glycol methyl ether acetate, n-butyl acetate and xylene into a dispersion cylinder, and treat at a speed of 500 rpm for 5 min to obtain C component, which is also called diluent.

[0154] Examples 1-7

[0155] The combination of A component and B component of polyurethane white primer examples is shown in Table 5.

[0156] Table 5 Polyurethane white primer examples

[0157]

[0158]

[0159] An appropriate amount of C component was added to the polyurethane white primer prepared in Examples 1-7, respectively, to adjust to the application viscosity, and the viscosity was 10-14 s.

[0160] Comparative Examples 1-5

[0161] The combination of A component and D-B component of the polyurethane white primer examples provided in the comparative examples is shown in Table 6 below.

[0162] Table 6 Polyurethane White Primer Comparative Examples

[0163]

[0164] An appropriate amount of C component was added to the polyurethane white primer prepared in Comparative Examples 1-4, respectively, to adjust to the application viscosity, and the viscosity was 10-14 s.

[0165] The primer provided in Examples 1-7 and Comparative Examples 1-5 was applied by spraying method, and the performance of the coating film was measured, and the measurement results are shown in Tables 7-10.

[0166] Table 7

[0167]

[0168]

[0169] Table 8

[0170]

[0171] Table 9

[0172]

[0173]

[0174] Table 10

[0175]

[0176] The performance tests in Tables 7-10 were detected according to the standards of GB 18581-2009 and GB / T 23997-2009.

[0177] In the cold and hot cycle test in Tables 9-10, one cycle included: -20℃ / 2h, 60℃ / 2h.

[0178] As can be seen from Tables 7-10, the polyurethane white primer prepared in the embodiments of the present application meets the limited requirements of harmful substances in the paint film after spraying, and the hardness, polishing property, workability, adhesion and heat storage performance of the paint film all meet the use requirements, the paint film has high fullness and good coating effect, and there is no problem of cracking, peeling and collapse. In combination with Example 1 and Comparative Examples 1-4, it can be seen that the compounding ratio of the aliphatic isocyanate adduct curing agent and the toluene diisocyanate trimer curing agent is adjusted, thereby affecting the crosslinking effect of the film-forming material and the curing agent, and the obtained paint film has the problem of cracking and peeling after cold and hot cycle test.

[0179] In summary, the polyurethane white primer provided by the embodiments of the present application uses two components, the A component is compounded with soybean oil modified alkyd resin and castor oil modified alkyd resin as the main film-forming material, and the B component is compounded with aliphatic isocyanate adduct curing agent and toluene diisocyanate trimer curing agent, the compounding of the two adjusts the crosslinking reaction speed and crosslinking structure between the soybean oil modified alkyd resin, the castor oil modified alkyd resin and the curing agent, so that the paint film formed after coating has fast drying, high hardness, good flexibility, strong adhesion and good wear resistance.

[0180] The above only describes the preferred embodiments of the present application and is not intended to limit the present application, and any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A polyurethane white primer, characterized in that, It includes component A and component B; the mass ratio of component A to component B is 100:40~50, wherein, Based on the total weight of component A as 100%, component A comprises the following components in the following weight percentages: Soybean oil modified alkyd resin 10%~30% Castor oil modified alkyd resin 15%~25% Titanium dioxide 15%~25% Filler content 26%~48% Excipients: 1.2%~5% Solvent A: 4%~8%; The hydroxyl value of the soybean oil-modified alkyd resin is 110~130 mgKOH / g; The hydroxyl value of the castor oil-modified alkyd resin is 130~140 mgKOH / g; Based on the total weight of component B as 100%, component B comprises the following components in the following weight percentages: Solvent B: 35%~40% Dehydrating agent 0.1%~0.5% Aliphatic isocyanate adduct curing agent 40%~45% Toluene diisocyanate trimer curing agent 15%~20%.

2. The polyurethane white primer as described in claim 1, characterized in that, The polyurethane white primer further includes component C, wherein the mass ratio of component A to component C is 100:10~20. Based on the total weight of component C as 100%, component C comprises the following components in the following weight percentages: Propylene glycol methyl ether acetate 40%~45% 30%~35% n-butyl acetate Xylene 20%~30%.

3. The polyurethane white primer as described in any one of claims 1 to 2, characterized in that, The soybean oil-modified alkyd resin has a solid content of 65% to 75%; and / or the castor oil-modified alkyd resin has a solid content of 65% to 75%.

4. The polyurethane white primer as described in any one of claims 1 to 2, characterized in that, The auxiliary agent includes at least one of wetting agent, defoamer, anti-settling agent and leveling agent.

5. The polyurethane white primer as described in claim 4, characterized in that, Based on the total weight of component A as 100%, the auxiliary agent comprises the following components in mass percentage: Wetting agent 0.5%~1% Defoamer 0.1%~0.5% Anti-settling agent 0.5%~3% Leveling agent 0.1%~0.5%.

6. The polyurethane white primer as described in claim 5, characterized in that, The wetting agent comprises a polymeric block copolymer containing pigment-affinity groups; and / or The defoamer includes a defoaming polysiloxane solution; and / or The anti-settling agent includes fumed silica; and / or The leveling agent includes a fluorocarbon polyacrylate leveling agent.

7. The polyurethane white primer as described in any one of claims 1 to 2, characterized in that, The filler comprises zinc stearate and talc in a mass ratio of 1~3:25~45; and / or Solvent A includes ether ester solvents and ester solvents in a mass ratio of 3~5:1~3.

8. The polyurethane white primer as described in any one of claims 1 to 2, characterized in that, The solvent B includes n-butyl acetate; and / or The dehydrating agent includes at least one of TI from Bayer (Germany) and BF5 from Airba (Germany).

9. A method for preparing a polyurethane white primer, characterized in that, Includes the following steps: The polyurethane white primer according to any one of claims 1 to 8 provides the component materials; The soybean oil-modified alkyd resin, the castor oil-modified alkyd resin, the titanium dioxide, the filler, the auxiliary agent, and solvent A are mixed and treated to obtain component A; The B component is obtained by mixing the solvent B, the dehydrating agent, the aliphatic isocyanate adduct curing agent, and the toluene diisocyanate trimer curing agent.

10. The application of the polyurethane white primer as described in any one of claims 1 to 8 in wood panels and wooden furniture.

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