Wear-resistant and sweat-resistant acrylic coating as well as preparation method and application thereof

Abstract

The invention provides a wear-resistant and sweat-resistant acrylic coating as well as a preparation method and application thereof, and belongs to the technical field of coatings. The wear-resistant and sweat-resistant acrylic coating is prepared from the following raw materials in parts by weight: 30 to 50 parts of waterborne acrylic resin, 15 to 20 parts of cardanol-based polyurethane resin, 0.8 to 1.5 parts of an adhesion promoter, 3 to 5 parts of a titanate coupling agent, 3 to 15 parts of filler, 0.5 to 1.8 parts of a thickening agent, 0.5 to 2.0 parts of a flatting agent, 0.5 to 1.0 part of a wetting agent, 0.5 to 1.5 parts of a de-foaming agent, 0.5 to 2 parts of a cosolvent and 5 to 15 parts of water. Wherein the water-based acrylic resin is prepared from the following components: an acrylic monomer, dithioglycolic acid, tri-n-butyl borane and an aziridine cross-linking agent; the invention also provides a preparation method of the acrylic coating. A coating layer obtained by curing the acrylic coating provided by the invention is excellent in mechanical property, good in adhesive force, excellent in water resistance, scratch resistance, wear resistance, chemical resistance, perspiration resistance, corrosion resistance and the like, and can be applied to 3C product and glasses industries, and the service life of the product is prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings, and particularly relates to a wear-resistant and sweat-resistant acrylic coating, a preparation method thereof, and an application thereof in the 3C product and glasses industries. Background Art

[0002] As people's lives become more intelligent and mobile Internet-based, the usage of electronic products such as mobile phones and computers (collectively referred to as 3C products) and glasses by people is increasing. Therefore, people's requirements for the quality of these products are also getting higher and higher. However, electronic products or glasses are touched, knocked, and rubbed by hands for a long time, which affects the appearance, comfort, and durability of the products. At the same time, the sweat on the human hand contains salts, acid-base components, and other chemical substances, which may erode the surface of the products. Therefore, in addition to properties such as lightness, good adhesion, solvent resistance, and water resistance, the coating applied to the product surface also needs to have excellent wear resistance and sweat resistance to ensure the service life and appearance of the product.

[0003] Acrylic coatings are coatings with acrylic resin as the main film-forming substance, and appropriate pigments, solvents, and additives are added according to requirements. They form a hard paint film through chemical reactions, have good gloss, weather resistance, chemical resistance, etc., and are inexpensive. However, traditional acrylic coatings are generally solvent-based, and a large amount of organic matter will be volatilized after coating. The ozone generated by this organic volatile matter under the action of light will have a certain impact on human health. Compared with solvent-based acrylic coatings, waterborne acrylic coatings use water instead of organic solvents, reducing the release of VOCs. They are an environmentally friendly type of coating and are also the focus of research by R & D personnel in various countries. Existing waterborne acrylic coatings not only have excellent gloss and adhesion but also have excellent weather resistance and chemical resistance. However, their physical properties are poor, and their properties such as hardness, wear resistance, scratch resistance, water resistance, and sweat resistance are not good. Therefore, it is necessary to develop an acrylic coating with excellent properties such as wear resistance, sweat resistance, water resistance, good adhesion, and scratch resistance to meet the usage requirements of 3C products and glasses, and thus extend the service life of the products.

[0004] The invention patent CN201911068870.1 discloses a sweat-resistant water-soluble acrylic resin coating. The components of the coating include a fluorinated acrylic resin, a butyl etherified amino resin, a dispersant, an antifoaming agent, a leveling agent, and water. The fluorinated acrylic resin is composed of components such as fluorinated acrylic monomers, acrylic acid, methyl methacrylate, and isooctyl methacrylate, and has the characteristics of sweat resistance and high abrasion resistance. However, the coating has poor solvent resistance, general anti-corrosion performance, and a high cost. The invention patent CN202310106193.8 discloses an aqueous acrylic coating. The components of the coating include 50-60 parts of an aqueous acrylic emulsion, 5-10 parts of a brominated alkyd resin, 5-10 parts of a silane coupling agent, 10-15 parts of a pigment, and 1-5 parts of polyaniline. The coating obtained by curing the aqueous acrylic coating has good weather resistance, corrosion resistance, and adhesion. However, the coating has poor water resistance, and its sweat resistance and abrasion resistance are both average, and it cannot be applied to electronic products or glasses. Summary of the Invention

[0005] The object of the present invention is to provide an acrylic coating with wear resistance and sweat resistance. The coating obtained by curing the acrylic coating has excellent mechanical properties, good adhesion, and excellent water resistance, scratch resistance, abrasion resistance, chemical resistance, sweat resistance, and corrosion resistance, etc., and can be applied to the 3C product and glasses industries, extending the service life of the products.

[0006] To achieve the object of the present invention, the present invention provides an acrylic coating with wear resistance and sweat resistance, which is composed of the following raw materials in parts by weight: 30-50 parts of an aqueous acrylic resin, 15-20 parts of a cardanol-based polyurethane resin, 0.8-1.5 parts of an adhesion promoter, 3-5 parts of a titanate coupling agent, 3-15 parts of a filler, 0.5-1.8 parts of a thickener, 0.5-2.0 parts of a leveling agent, 0.5-1.0 parts of a wetting agent, 0.5-1.5 parts of an antifoaming agent, 0.5-2 parts of a cosolvent, and 5-15 parts of water.

[0007] Preferably, the titanate coupling agent is isopropyl dioleoyl oxy (dioctyl phosphatooxy) titanate, that is, titanate coupling agent 101. The addition of the titanate coupling agent enables each component to be evenly dispersed in the coating, thereby improving the adhesion of the coating and enhancing the water resistance, weather resistance, and corrosion resistance of the aqueous acrylic coating.

[0008] Preferably, the thickener is selected from any one of hydroxyethyl cellulose, organic bentonite, and associative polyurethane thickener. The addition of the thickener improves the rheology and storage stability of the coating, prevents the coating from sagging during construction, has good leveling properties, and thus makes the coating film smooth and has a high gloss.

[0009] Preferably, the leveling agent is selected from silicone rheology agents, which improves the dispersibility of the coating, enhances the rapid leveling performance during coating construction, and thus improves the coating effect and quality.

[0010] Preferably, the wetting agent is alkyl polyoxyethylene ether, which improves the dispersibility and wettability of the coating system, can effectively reduce the surface tension of the coating, and thus enhances the adhesion of the coating film.

[0011] Preferably, the defoaming agent is any one of phenethyl alcohol oleate, dimethyl silicone oil or polyoxypropylene glycerol ester, which is used to reduce the surface tension of the foam, achieve the effects of rapid defoaming and long-term foam suppression, improve the powder coating rate and spraying effect of the coating, ensure the abrasion resistance and durability of the coating, and thus ensure the smoothness and beauty of the coating surface.

[0012] Preferably, the cosolvent is ethanol or 1-methoxy-2-propanol, which can adjust the viscosity of the coating, play a balancing role, make the coating of the present invention have high stability, can be stored stably for a long time, and extends the storage life of the coating.

[0013] The preparation method of the waterborne acrylic resin specifically includes the following steps:

[0014] S1. First, add 1 / 2 of the mass of tri-n-butyl borane to an appropriate amount of ethylene glycol monobutyl ether and dissolve it completely, then add it to the reaction kettle, and heat up to 60-70 °C;

[0015] S2. Weigh the acrylic monomers, 1 / 3 of the mass of aziridine crosslinking agent and the remaining tri-n-butyl borane according to the formula, mix them evenly, and then drop them into the reaction kettle at a constant speed within 2-3 h, control the reaction temperature at 70-80 °C, keep warm for 1-1.5 h, then drop in dithiodiglycolic acid and the remaining aziridine crosslinking agent, control the dropping time within 30 min, and react for 2-3 h;

[0016] S3. After the reaction is completed, lower the temperature of the reaction kettle to 40 °C, add ammonia water for neutralization while stirring, stir and react for 15-25 min, and cool to room temperature to obtain acrylic resin;

[0017] S4. Mix the above acrylic resin, absolute ethanol and deionized water thoroughly and stir evenly to prepare the waterborne acrylic resin.

[0018] Furthermore, the waterborne acrylic resin is composed of the following raw materials in parts by weight: 82-90 parts of acrylic monomers, 3-7 parts of dithiodiglycolic acid, 2-4 parts of tri-n-butyl borane and 2-5 parts of aziridine crosslinking agent;

[0019] In the step S4, the mass of the absolute ethanol is 20-25% of the mass of the acrylic resin; the mass of the deionized water is 30-35% of the mass of the acrylic resin.

[0020] Further, the acrylic monomer is composed of monomers in the following parts by weight: 45 - 55 parts of methyl methacrylate, 20 - 30 parts of tert-butyl methacrylate, 3 - 6 parts of acrylamide, 14 - 18 parts of pentaerythritol triacrylate, and 4 - 6 parts of vinyl acrylic acid.

[0021] The coating of the present invention uses waterborne acrylic resin as the main film-forming matrix. Through the polymerization reaction of acrylic monomers under the action of aziridine crosslinking agent and tri-n-butyl borane, a prepolymer is prepared, and then dithioglycolic acid is introduced for reaction. The acrylic monomers in the present invention are composed of methyl methacrylate, tert-butyl methacrylate, acrylamide, pentaerythritol triacrylate, and vinyl acrylic acid in specific proportions. By using acrylic monomers with different characteristics in combination, the polymerized structure contains chain segments with specific groups, while ensuring high hardness, high toughness, and high strength of the acrylic resin, it also improves the adhesion, weather resistance, sweat resistance, and corrosion resistance of the acrylic resin; by optimizing the types and ratios of monomers, it is beneficial to increase the crosslinking density of the coating, thereby increasing the hardness and wear resistance of the coating; the use of aziridine crosslinking agent and pentaerythritol triacrylate both improves the sweat resistance and water resistance of the present invention, but if the use temperature is relatively high, the water resistance and sweat resistance are not good; the addition of vinyl acrylic acid ensures better toughness of the coating of the present invention, while also having relatively high hardness and good wear resistance. The introduction of dithioglycolic acid improves the wear resistance of the present invention and does not affect other characteristics of the coating.

[0022] Further, the preparation method of the cardanol-based polyurethane resin specifically includes the following steps:

[0023] P1. Add cardanol-based polyol and polypropylene glycol into a container, evacuate under vacuum at 100 - 120 °C for 1.0 - 2.0 h, then relieve the vacuum and introduce nitrogen, cool down to 40 - 50 °C, add dibutyltin dilaurate and hexamethylene diisocyanate, and raise the temperature to 70 - 80 °C for reaction for 1 - 2 h to obtain a prepolymer;

[0024] P2. Add polytetrahydrofuran glycol to the above prepolymer, continue the reaction at 70 - 80 °C for 3 - 4 h, then cool down to 50 - 60 °C, add hydroxyethyl methacrylate, keep warm for 2 - 4 h, until the -NCO content is measured ≤ 0.1%, then cool naturally and evacuate under vacuum for 5 - 10 min to obtain the cardanol-based polyurethane resin.

[0025] Further, the mass ratio of the hexamethylene diisocyanate to the cardanol-based polyol is (40 - 60) : 100;

[0026] The addition amount of the polypropylene glycol is 15-30% of the total mass of the hexamethylene diisocyanate and the cardanol-based polyol;

[0027] The addition amount of the dibutyltin dilaurate is 0.06-0.10% of the total mass of the hexamethylene diisocyanate and the cardanol-based polyol;

[0028] The addition amount of the polytetrahydrofuran diol is 2.0-2.8% of the total mass of the hexamethylene diisocyanate and the cardanol-based polyol;

[0029] The mass ratio of the hydroxyethyl methacrylate to the hexamethylene diisocyanate is 1:(0.5-0.65).

[0030] Further, the hydroxy value of the cardanol-based polyol is 175 mg KOH / g, and the functionality is 3.8.

[0031] By adding the cardanol-based polyurethane resin, the present invention significantly improves the mechanical strength, adhesion and water resistance of the acrylic coating, and also improves the high-temperature resistance, sweat resistance, abrasion resistance and chemical corrosion resistance of the acrylic coating. The cardanol-based polyurethane resin of the present invention is prepared by reacting cardanol-based polyol and hexamethylene diisocyanate under the action of dibutyltin dilaurate to obtain a polyurethane prepolymer containing cardanol groups, then adding polytetrahydrofuran diol for reaction, and finally adding hydroxyethyl methacrylate for end-capping. Compared with conventional polyether polyols, the use of cardanol-based polyol to prepare polyurethane in the present invention significantly improves the adhesion, abrasion resistance, water resistance, chemical resistance and sweat resistance of the coating of the present invention; the addition of polytetrahydrofuran diol not only increases the strength and toughness of the aqueous polyurethane resin, but also improves the viscosity, water resistance, abrasion resistance and weather resistance of the coating of the present invention; the use of hydroxyethyl methacrylate for end-capping improves the stability of the cardanol-based polyurethane resin in the acrylic coating, and at the same time increases the compatibility with other components in the coating of the present invention, improving the adhesion, water resistance and sweat resistance of the coating of the present invention.

[0032] Further, the adhesion promoter is composed of a silane compound containing an oxazole, a hyperbranched unsaturated resin and polyvinylpyrrolidone in a mass ratio of (1.2-1.5):(2.0-2.5):1.

[0033] The adhesion promoter prepared by compounding a specific proportion of azole-containing silane compounds, hyperbranched unsaturated resins, and polyvinylpyrrolidone not only improves the adhesion between the coating and the substrate, but also significantly improves the sweat resistance, abrasion resistance, chemical corrosion resistance, weather resistance, etc. of the coating of the present invention. The addition of polyvinylpyrrolidone improves the compatibility between the azole-containing silane compounds and the hyperbranched unsaturated resins, and also enables the adhesion promoter to be uniformly dispersed in the acrylic coating system, thereby increasing the adhesion of the coating; the addition of the azole-containing silane compounds not only improves the adhesion of the coating of the present invention, but also improves the water resistance, sweat resistance, and corrosion resistance of the present invention; when combined with the hyperbranched unsaturated resin, the present invention still has excellent sweat resistance and abrasion resistance in a high-temperature environment.

[0034] Further, the azole-containing silane compound is a triazole silane compound.

[0035] The present invention also provides a method for preparing a wear-resistant and sweat-resistant acrylic coating, which specifically includes the following steps:

[0036] (1) Mix the aqueous acrylic resin, cardanol-based polyurethane resin, adhesion promoter, and water evenly to obtain a first mixture;

[0037] (2) Mix the titanate coupling agent, filler, and cosolvent evenly to obtain a second mixture;

[0038] (3) Mix the first mixture and the second mixture evenly, then add a leveling agent, a wetting agent, and an antifoaming agent and stir evenly, and finally add a thickener and disperse evenly at a rate of 1200 - 1500 rpm to obtain the acrylic coating.

[0039] The present invention has achieved the following beneficial effects:

[0040] 1. The coating of the present invention uses an aqueous acrylic resin as the main film-forming matrix, and through the combination of different acrylic monomers with appropriate ratios, while ensuring that the obtained coating has excellent mechanical strength, adhesion, weather resistance, and corrosion resistance, it also improves the water resistance and abrasion resistance of the coating; by adding a cardanol-based polyurethane resin for compounding, the adhesion, water resistance, abrasion resistance, and corrosion resistance of the present invention are improved, the film-forming time is shortened, and the present invention has excellent sweat resistance and chemical solvent resistance; the addition of the adhesion promoter not only enhances the adhesion between the coating and the substrate, but also improves the sweat resistance, abrasion resistance, and chemical corrosion resistance of the present invention; the addition of components such as titanate coupling agent, filler, thickener, leveling agent, wetting agent, and antifoaming agent obtains a more stable organizational structure, improves the stability of the present invention, and further ensures that the present invention has better comprehensive performance to extend the service life of the coating in electronic products.

[0041] 2. The raw materials selected in the present invention are environmentally friendly, with low costs, simple preparation processes, low energy consumption, and do not contain volatile toxic substances, meeting the requirements of the national environmental protection law.

[0042] 3. The coating of the present invention has a low viscosity, and processes such as curtain coating and spraying can be adopted. The operation is simple, the film-forming time is short, the production efficiency is high, the cost is low, and automated operation can be achieved.

[0043] 4. The coating prepared from the coating of the present invention is dense, with high adhesion, hardness, and mechanical strength, and has excellent chemical corrosion resistance, flame retardancy, weather resistance, sweat resistance, and abrasion resistance. It can be applied to the 3C product and glasses industries, extending the service life of the products. Detailed implementation manners

[0044] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0045] The wear-resistant and sweat-resistant acrylic coating and its preparation method of the present invention will be described below in conjunction with specific embodiments.

[0046] Example 1

[0047] The preparation method of the wear-resistant and sweat-resistant acrylic coating in Example 1 is as follows by mass parts:

[0048] (1) 30 parts of waterborne acrylic resin, 15 parts of cardanol-based polyurethane resin, 0.8 part of adhesion promoter, and 10 parts of water are mixed evenly to obtain a first mixture;

[0049] (2) 3.2 parts of titanate coupling agent 101 (i.e., isopropyl dioleate acyloxy (dioctyl phosphate acyloxy)), 8.5 parts of filler, and 1.1 part of ethanol are mixed evenly to obtain a second mixture;

[0050] (3) The first mixture and the second mixture are mixed evenly, then 0.5 part of BYK 7305 rheology agent, 0.5 part of alkyl polyoxyethylene ether HY-352, and 0.6 part of dimethyl silicone oil are added and stirred evenly. Finally, 0.8 part of non-ionic polyurethane thickener is added and dispersed evenly at a rate of 1200 rpm to obtain the wear-resistant and sweat-resistant acrylic coating.

[0051] By mass parts, the preparation process of the above aqueous acrylic resin is as follows: First, add 1 part of tri-n-butyl borane to an appropriate amount of ethylene glycol monobutyl ether and dissolve it completely, then add it to the reaction kettle and heat up to 60 °C; then weigh 82 parts of acrylic monomers, 0.8 part of aziridine crosslinking agent and 1 part of tri-n-butyl borane, mix them evenly, and drop them into the reaction kettle at a uniform speed, which needs to be completed within 2.5 h. During the dropping process, raise the temperature to 80 °C. After the dropping is completed, keep the temperature at this temperature for another 1.5 h, then drop 4.2 parts of dithioglycolic acid and 1.6 parts of aziridine crosslinking agent, and control the dropping time within 30 min, and react for 3 h; after the reaction is completed, lower the temperature of the reaction kettle to 40 °C, add ammonia water for neutralization while stirring, stir and react for 20 min, and cool to room temperature to obtain acrylic resin; fully stir 100 parts of the prepared acrylic resin, 24 parts of absolute ethanol and 32 parts of deionized water to obtain the aqueous acrylic resin.

[0052] The components of the above acrylic monomers are: 45 parts of methyl methacrylate, 30 parts of tert-butyl methacrylate, 6 parts of acrylamide, 14 parts of pentaerythritol triacrylate and 5 parts of vinyl acrylic acid.

[0053] The preparation process of the above cardanol-based polyurethane resin is as follows: Add 100 parts of cardanol-based polyol (hydroxyl value is 175 mgKOH / g, functionality is 3.8) and 33.6 parts of polypropylene glycol 2000 to a container, evacuate at 110 °C for 2.0 h, then relieve the vacuum and introduce nitrogen, cool down to 40 °C, add 0.12 part of dibutyltin dilaurate and 52.6 parts of hexamethylene diisocyanate, and raise the temperature to 75 °C and react for 2 h to obtain a prepolymer; add 3.8 parts of polytetrahydrofuran diol to the prepared prepolymer, continue to react at 75 °C for 3 h, then cool down to 60 °C, add 94 parts of 2-hydroxyethyl methacrylate, keep warm for 4 h until the measured -NCO content ≤ 0.1%, then cool naturally and evacuate simultaneously for 10 min to obtain the cardanol-based polyurethane resin.

[0054] The above adhesion promoter is composed of a triazole silane compound, a hyperbranched unsaturated resin Hyper U102 and polyvinylpyrrolidone with a mass ratio of 1.5:2:1, that is, first mix the triazole silane compound and polyvinylpyrrolidone evenly, and then add the hyperbranched unsaturated resin Hyper U102 for mixing.

[0055] The preparation process of the above triazole silane compound is as follows: Add 20% sodium carbonate solution to a mixed solution of 3-amino-5-ethyl-1,2,4-triazole and 100 mL of N-methylpyrrolidone at room temperature, heat to 60 °C and stir for 1 h, then add 3-chloropropyltriethoxysilane, stir at 80 °C for 6 h. After the reaction is completed, cool to room temperature, filter, and wash the filter cake with 2% NaHCO 3Wash with solution and deionized water until neutral, then dry to obtain the triazolesilane compound; the molar ratio of 3-amino-5-ethyl-1,2,4-triazole, sodium carbonate solution and 3-chloropropyltriethoxysilane is 1:1:1. (The triazolesilane compounds used in the following examples and comparative examples are the same as those here and will not be elaborated below.)

[0056] The above filler is composed of titanium dioxide and talcum powder with a mass ratio of 1:1.

[0057] Example 2

[0058] The preparation method of the wear-resistant and sweat-resistant acrylic coating in this Example 2 is as follows by mass parts:[[]]END]]

[0059] (1) Mix 50 parts of waterborne acrylic resin, 20 parts of cardanol-based polyurethane resin, 1.5 parts of adhesion promoter and 15 parts of water evenly to obtain the first mixture;

[0060] (2) Mix 4.3 parts of titanate coupling agent 101, 14.6 parts of filler and 1.8 parts of 1-methoxy-2-propanol evenly to obtain the second mixture;

[0061] (3) Mix the first mixture and the second mixture evenly, then add 1.2 parts of BYK 7305 rheology agent, 0.9 part of alkyl polyoxyethylene ether HY-352 and 1.2 parts of dimethyl silicone oil and stir evenly. Finally, add 1.8 parts of non-ionic polyurethane thickener and disperse evenly at a rate of 1500 rpm to obtain the wear-resistant and sweat-resistant acrylic coating.

[0062] The preparation process of the above waterborne acrylic resin by mass parts is as follows: First, add 2 parts of tri-n-butyl borane to an appropriate amount of ethylene glycol monobutyl ether and dissolve it completely, then add it to the reaction kettle and heat up to 60 °C; then weigh 90 parts of acrylic monomers, 1.6 parts of aziridine crosslinking agent and 2 parts of tri-n-butyl borane and mix evenly, and slowly drip them into the reaction kettle, which needs to be controlled to finish dripping within 3 h. During the dripping process, raise the temperature to 80 °C. After the dripping is completed, keep the temperature at this temperature for another 1.5 h, then drip 7 parts of dithioglycolic acid and 3.2 parts of aziridine crosslinking agent, and control the dripping time within 30 min and react for 3 h; after the reaction is completed, lower the temperature of the reaction kettle to 40 °C, add ammonia water for neutralization while stirring, stir and react for 20 min, and cool to room temperature to obtain acrylic resin; fully stir 100 parts of the prepared acrylic resin, 24 parts of absolute ethanol and 32 parts of deionized water evenly to prepare the waterborne acrylic resin.

[0063] The components of the above acrylic monomers are: 55 parts of methyl methacrylate, 20 parts of tert-butyl methacrylate, 3 parts of acrylamide, 18 parts of pentaerythritol triacrylate and 4 parts of vinyl acrylic acid.

[0064] The sources of the above aziridine crosslinking agent and dithioglycolic acid are the same as those in Example 1.

[0065] The preparation process of the above cardanol-based polyurethane resin is the same as that in Example 1, and specifically refer to Example 1.

[0066] The above adhesion promoter is composed of a triazole silane compound, a hyperbranched unsaturated resin Hyper U102, and polyvinylpyrrolidone with a mass ratio of 1.5:2.5:1. That is, first mix the azole-containing silane compound and polyvinylpyrrolidone evenly, and then add the hyperbranched unsaturated resin Hyper U102 for mixing evenly.

[0067] The above filler is composed of titanium dioxide and talcum powder with a mass ratio of 1:1.

[0068] Example 3

[0069] By mass, the preparation method of the wear-resistant and sweat-resistant acrylic paint in this Example 3 is as follows:

[0070] (1) Mix 44 parts of waterborne acrylic resin, 18 parts of cardanol-based polyurethane resin, 1.2 parts of adhesion promoter, and 15 parts of water evenly to obtain a first mixture;

[0071] (2) Mix 3.2 parts of titanate coupling agent 101, 12.9 parts of filler, and 1.5 parts of ethanol evenly to obtain a second mixture;

[0072] (3) Mix the first mixture and the second mixture evenly, then add 1.0 part of BYK 7305 rheology agent, 0.6 part of alkyl polyoxyethylene ether HY-352, and 0.9 part of dimethyl silicone oil and stir evenly. Finally, add 1.4 parts of non-ionic polyurethane for thickening and disperse evenly at a rate of 1500 rpm to obtain the wear-resistant and sweat-resistant acrylic paint.

[0073] By mass, the preparation process of the above waterborne acrylic resin is as follows: First, add 1.6 parts of tri-n-butyl borane to an appropriate amount of ethylene glycol monobutyl ether and dissolve it completely, then add it to the reaction kettle and heat up to 60 °C; then weigh 86 parts of acrylic monomers, 1.2 parts of aziridine crosslinking agent, and 1.6 parts of tri-n-butyl borane and mix them evenly, and slowly drip them into the reaction kettle, which needs to be controlled to finish dripping within 3 h. During the dripping process, raise the temperature to 80 °C. After the dripping is completed, keep the temperature at this temperature for 1.5 h, then drip 5.4 parts of dithioglycolic acid and 2.4 parts of aziridine crosslinking agent, and control the dripping time within 30 min and react for 3 h; after the reaction is completed, lower the temperature of the reaction kettle to 40 °C, add ammonia water for neutralization while stirring, stir and react for 20 min, and cool to room temperature to obtain acrylic resin; fully stir 100 parts of the prepared acrylic resin, 24 parts of absolute ethanol, and 32 parts of deionized water evenly to prepare the waterborne acrylic resin.

[0074] The components of the above acrylic monomer are: 48 parts of methyl methacrylate, 25 parts of tert-butyl methacrylate, 5 parts of acrylamide, 16 parts of pentaerythritol triacrylate, and 6 parts of vinyl acrylic acid.

[0075] The preparation process of the above cardanol-based polyurethane resin is the same as that in Example 1, and for details, please refer to Example 1.

[0076] The above adhesion promoter is composed of a triazole silane compound, a hyperbranched unsaturated resin Hyper U102, and polyvinylpyrrolidone with a mass ratio of 1.5:2.0:1. That is, first, the azole-containing silane compound and polyvinylpyrrolidone are fully mixed evenly, and then the hyperbranched unsaturated resin Hyper U102 is added for mixing evenly.

[0077] The above filler is composed of titanium dioxide and talcum powder with a mass ratio of 1:1.

[0078] Comparative Example 1

[0079] The components and preparation method of the acrylic coating in this comparative example are the same as those in Example 3. The difference is that dithioglycolic acid is not added during the preparation process of the waterborne acrylic resin in this Comparative Example 1.

[0080] Comparative Example 2

[0081] The components and preparation method of the acrylic coating in this comparative example are the same as those in Example 3. The difference is that the acrylic monomer in this Comparative Example 2 is composed of 48 parts of methyl methacrylate, 25 parts of tert-butyl methacrylate, 5 parts of acrylamide, 16 parts of pentaerythritol tetraacrylate, and 6 parts of vinyl acrylic acid.

[0082] Comparative Example 3

[0083] The components and preparation method of the acrylic coating in this comparative example are the same as those in Example 3. The difference is that trimethylolpropane trimethacrylate is used to replace the aziridine crosslinker in this Comparative Example 3.

[0084] Comparative Example 4

[0085] The components and preparation method of the acrylic coating in this comparative example are the same as those in Example 3. The difference is that polycaprolactone diol is used to replace the cardanol-based polyol in this Comparative Example 4.

[0086] Comparative Example 5

[0087] The components and preparation method of the acrylic coating in this comparative example are the same as those in Example 3. The difference is that ethylenediamine is used to replace polytetrahydrofuran diol in this Comparative Example 5.

[0088] Comparative Example 6

[0089] The components and preparation method of the acrylic paint in this comparative example are the same as those in Example 3. The difference is that the adhesion promoter in this Comparative Example 6 is composed of hyperbranched unsaturated resin Hyper U102 and polyvinylpyrrolidone with a mass ratio of 2:1.

[0090] Comparative Example 7

[0091] The components and preparation method of the acrylic paint in this comparative example are the same as those in Example 3. The difference is that the adhesion promoter in this Comparative Example 7 is composed of a triazole silane compound and polyvinylpyrrolidone with a mass ratio of 1.5:1.

[0092] The acrylic paints prepared in the above Examples 1-3 and Comparative Examples 1-7 were applied to PC substrates, and the properties of the formed paint films were tested respectively, such as adhesion, abrasion resistance, sweat resistance, damp heat resistance, salt spray resistance, etc. The test results are shown in Table 1 below.

[0093] Adhesion test: Detection was carried out according to GB / T 9286-1998 "Cross-cut test for paints and varnishes films".

[0094] Abrasion resistance: Referring to ISO7784-2:2016, the test was carried out at a temperature of (23±2)°C and a relative humidity of (50±5)%, and the abrasion resistance of the paint (750g / 500r) was measured.

[0095] Sweat resistance: Detection was carried out according to the EU standard I5012870.

[0096] Damp heat resistance: The samples were treated according to GB / T2423.50-2012, at 85°C, 85% rh, for 1000h. After the double 85 test, the adhesion and abrasion resistance of the samples were detected.

[0097] Salt spray resistance: Detection was carried out according to GB / T1771-2007.

[0098] Table 1 Performance test results of acrylic paints

[0099]

[0100] It can be seen from the test results in Table 1 that the acrylic paint of the present invention has excellent adhesion, abrasion resistance, sweat resistance, damp heat resistance, salt spray resistance, etc.; by using the waterborne acrylic resin of the present invention, the abrasion resistance and damp heat resistance of the present invention are significantly improved; by using the cardanol-based polyurethane resin of the present invention, the adhesion, sweat resistance, abrasion resistance, damp heat resistance and salt spray resistance of the present invention are significantly improved; by using the adhesion promoter of the present invention, the adhesion, sweat resistance and abrasion resistance of the present invention are significantly improved.

[0101] It should be noted that in the embodiments of the present invention, only one specific component is selected for analysis for each component. In fact, other components or models not mentioned in the present invention can also be selected.

[0102] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0103] The above-described embodiments only represent several implementation manners of the present invention, and the description thereof is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A wear-resistant and sweat-resistant acrylic paint, characterized in that: The invention is composed of the following raw materials in parts by weight: 30-50 parts of water-based acrylic resin, 15-20 parts of cardanol-based polyurethane resin, 0.8-1.5 parts of adhesion promoter, 3-5 parts of titanate coupling agent, 3-15 parts of filler, 0.5-1.8 parts of thickener, 0.5-2.0 parts of leveling agent, 0.5-1.0 parts of wetting agent, 0.5-1.5 parts of defoamer, 0.5-2 parts of cosolvent and 5-15 parts of water; The preparation method of the water-based acrylic resin specifically comprises the following steps: S1. First, add 1 / 2 mass of tri-n-butyl borane to an appropriate amount of ethylene glycol butyl ether to dissolve completely, then add it to the reactor and heat it to 60-70°C; S2. According to the formula, the acrylic monomer, 1 / 3 of the mass of the aziridine crosslinker and the remaining tri-n-butylborane were weighed, mixed evenly, and then added dropwise to the reactor at a uniform rate within 2-3 hours, the reaction temperature was controlled at 70-80 ° C, and the temperature was kept for 1-1.5 hours, and then dithioglycolic acid and the remaining aziridine crosslinker were added dropwise, the addition time was controlled within 30 minutes, and the reaction was allowed to proceed for 2-3 hours; S3. After the reaction, the reactor temperature was lowered to 40 ° C, aqueous ammonia was added while stirring for neutralization, the reaction was stirred for 15-25 min, and cooled to room temperature to obtain an acrylic resin; S4. The acrylic resin, anhydrous ethanol and deionized water are fully stirred to obtain a water-based acrylic resin.

2. The wear-resistant and sweat-resistant acrylic paint according to claim 1, characterized in that: The water-based acrylic resin is composed of the following raw materials in parts by weight: 82-90 parts of acrylic monomer, 3-7 parts of dithioglycolic acid, 2-4 parts of tri-n-butylborane and 2-5 parts of aziridine crosslinking agent; In the step S4, the mass of the anhydrous ethanol is 20-25% of the mass of the acrylic resin; the mass of the deionized water is 30-35% of the mass of the acrylic resin.

3. The wear-resistant and sweat-resistant acrylic paint according to claim 2, characterized in that: The acrylic monomer is composed of the following monomers in parts by weight: 45-55 parts of methyl methacrylate, 20-30 parts of tert-butyl methacrylate, 3-6 parts of acrylamide, 14-18 parts of pentaerythritol triacrylate and 4-6 parts of vinyl acrylic acid.

4. The wear-resistant and sweat-resistant acrylic paint according to claim 1, characterized in that: The preparation method of the cardanol-based polyurethane resin specifically comprises the following steps: P1. Add cardanol polyol and polypropylene glycol to a container, evacuate at 100-120°C for 1.0-2.0h, then release the vacuum and introduce nitrogen, cool to 40-50°C, add dibutyltin dilaurate and hexamethylene diisocyanate, and heat to 70-80°C for reaction for 1-2h to obtain a prepolymer; P2. Add polytetrahydrofuran diol to the above prepolymer, continue to react at 70-80°C for 3-4h, then cool to 50-60°C, add ammonium hydroxyethyl methacrylate, keep warm for 2-4h, until the -NCO content is measured to be ≤0.1%, cool naturally and evacuate for 5-10min to obtain cardanol-based polyurethane resin.

5. The wear-resistant and sweat-resistant acrylic paint according to claim 4, characterized in that: The mass ratio of hexamethylene diisocyanate to cardanol polyol is (40-60):100; The amount of the polypropylene glycol added is 15-30% of the total mass of the hexamethylene diisocyanate and the cardanol-based polyol; The amount of dibutyltin dilaurate added is 0.06-0.10% of the total mass of the hexamethylene diisocyanate and the cardanol-based polyol; The amount of the polytetrahydrofuran diol added is 2.0-2.8% of the total mass of the hexamethylene diisocyanate and the cardanol-based polyol; The mass ratio of the ammonium hydroxyethyl methacrylate to the hexamethylene diisocyanate is 1:(0.5-0.65).

6. The wear-resistant and sweat-resistant acrylic paint according to claim 4, characterized in that: The cardanol-based polyol has a hydroxyl value of 175 mg KOH / g and a functionality of 3.

8.

7. The wear-resistant and sweat-resistant acrylic paint according to claim 1, characterized in that: The adhesion promoter is composed of an azole-containing silane compound, a hyperbranched unsaturated resin and polyvinyl pyrrolidone in a mass ratio of (1.2-1.5):(2.0-2.5):

1.

8. The wear-resistant and sweat-resistant acrylic paint according to claim 7, characterized in that: The azole silane compound is a triazole silane compound.

9. A method for preparing a wear-resistant and sweat-resistant acrylic coating as claimed in any one of claims 1 to 8, characterized in that: The specific steps include: (1) uniformly mixing a water-based acrylic resin, a cardanol-based polyurethane resin, an adhesion promoter and water to obtain a first mixture; (2) uniformly mixing the titanate coupling agent, the filler and the co-solvent to obtain a second mixture; (3) The first mixture and the second mixture are mixed uniformly, and then a leveling agent, a wetting agent and a defoaming agent are added and stirred uniformly, and finally a thickener is added and dispersed uniformly at a speed of 1200-1500 rpm to obtain the acrylic paint.

10. Application of the wear-resistant and sweat-resistant acrylic paint according to any one of claims 1 to 8 in 3C products and eyewear industries.

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