High-gloss acrylic coating varnish and preparation method thereof

Abstract

The application belongs to the technical field of varnish and specifically relates to high-gloss acrylic coating varnish and a preparation method thereof. The high-gloss acrylic coating varnish comprises a main agent, a curing agent and a diluent in a mass ratio of 2-4:1:2-4. The main agent comprises the following raw materials in parts by mass: 40-60 parts of hydroxyl acrylic resin, 5-15 parts of synthetic fatty acid resin, 5-15 parts of functional resin, 0.5-3 parts of ultraviolet absorber, 0.5-2 parts of light stabilizer, 0.2-1 part of leveling agent, 0.2-1 part of adhesion promoter and 20-40 parts of solvent A. The curing agent comprises the following raw materials in parts by mass: 60-80 parts of isocyanate and 20-40 parts of solvent B. The functional resin is YQ528A toughness resin. The high-gloss acrylic coating varnish provided by the application has the characteristics of high gloss, high adhesion, high hardness, high wear resistance, high corrosion resistance and high weather resistance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of varnish, and particularly relates to a high-gloss acrylic coating varnish and a preparation method thereof. BACKGROUND

[0002] PC (polycarbonate) / ABS (polyacrylonitrile) material has been widely used in automobile exterior manufacturing and handicraft manufacturing due to its light weight and impact resistance. In order to improve its decorative properties, a vacuum metal coating is usually applied to the surface of the PC / ABS material, and then a varnish is applied to make it have a metallic luster. The use of the varnish is crucial, and affects the gloss and service life of the PC / ABS material product with a metal coating.

[0003] In addition to high gloss, good adhesion to the coating layer and high hardness, the varnish for the automobile door handle also needs to have good wear resistance, corrosion resistance and weather resistance.

[0004] There are few reports on the varnish for the automobile door handle of PC / ABS material in the prior art. The Chinese patent with the authorization publication number CN115926556B discloses a protective varnish for a selectively electroplated part of an automobile air intake grille, a preparation method and a use method. The varnish includes a base coating varnish and a top coating varnish. The base coating varnish takes amino acrylic resin as the main body resin, which provides excellent adhesion to different substrates and interlayer adhesion to the top coating layer. The top coating varnish takes fluororesin as the main body resin, which provides high weather resistance and various conventional physical property resistance. The performance of the composite coating layer of the base coating and the top coating is combined, thereby improving the corrosion resistance and meeting the performance detection requirements of the automobile body coating of the main machine factory. However, the base coating varnish and the top coating varnish of the technical solution are different components, and the scheme is relatively complex.

[0005] Therefore, it is of great significance to provide a coating varnish with high gloss, high adhesion, high hardness, high wear resistance, high corrosion resistance and high weather resistance for the automobile door handle of PC / ABS material. SUMMARY

[0006] The present application aims to solve at least one of the above technical problems in the prior art. To this end, the purpose of the present application is to provide a high-gloss acrylic coating varnish with the characteristics of high gloss, high adhesion, high hardness, high wear resistance, high corrosion resistance and high weather resistance.

[0007] The present application provides a preparation method of the high-gloss acrylic coating varnish.

[0008] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows:

[0009] The first aspect of this invention provides a high-gloss acrylic coating varnish, comprising a main agent, a curing agent, and a diluent in a mass ratio of 2-4:1:2-4; the main agent comprises the following raw materials in parts by mass: 40-60 parts of hydroxyl acrylic resin, 5-15 parts of synthetic fatty acid resin, 5-15 parts of functional resin, 0.5-3 parts of ultraviolet absorber, 0.5-2 parts of light stabilizer, 0.2-1 parts of leveling agent, 0.2-1 parts of adhesion promoter, and 20-40 parts of solvent A;

[0010] The curing agent comprises the following raw materials in parts by weight: 60-80 parts isocyanate and 20-40 parts solvent B;

[0011] The functional resin is YQ528A toughness resin.

[0012] Considering the application scenarios of the acrylic coating clear varnish of the present invention, for automotive door handles made of PC / ABS materials, in addition to aesthetic requirements (good gloss), door handles also need to have good wear resistance due to frequent use to avoid wear. During the experiment, the inventors unexpectedly discovered that by adding a specific YQ528A toughening resin, which works together with hydroxyl acrylic resin and synthetic fatty acid resin, the resulting acrylic coating clear varnish has better overall performance than organosilicon hydroxyl acrylate and high-grade saturated polyester resin. It has good gloss as well as good hardness, adhesion, corrosion resistance, weather resistance and wear resistance.

[0013] Furthermore, the mass ratio of the hydroxyl acrylic resin, synthetic fatty acid resin, and functional resin is 5-7:1:1-2.

[0014] In this invention, different resins are present in the main agent, and the ratio between them is crucial to the overall performance of the acrylic coating varnish. After extensive experimental research, the inventors found that when the mass ratio of hydroxyl acrylic resin, synthetic fatty acid resin and functional resin is controlled at 5-7:1:1-2, the overall performance of the acrylic coating varnish is better. Otherwise, the gloss, corrosion resistance and weather resistance of the coating film will be significantly reduced.

[0015] Furthermore, the main agent comprises the following raw materials in parts by weight: 50 parts hydroxy acrylic resin, 12 parts synthetic fatty acid resin, 12 parts functional resin, 1 part ultraviolet absorber, 0.5 parts light stabilizer, 0.5 parts leveling agent, 0.5 parts adhesion promoter, and 30 parts solvent A.

[0016] Furthermore, the hydroxyl acrylic resin is selected from at least one of PAR-1153-75, PAR-1132-70, PAR-1137-75, and PAR-1139-80 produced by Guangdong Jiayuan New Materials Co., Ltd.

[0017] Furthermore, the hydroxy acrylic resin is a mixture of PAR-1153-75 and PAR-1137-75 in a mass ratio of 1:3-5.

[0018] The hydroxyl acrylic resin used in this invention is from Guangdong Jiayuan New Materials Co., Ltd. Through exploration and experimentation, it was found that PAR-1153-75 and PAR-1137-75 have good effects. In particular, when the two are used together, the hardness can reach 2H and the gloss retention rate is greater than 95% after weathering test.

[0019] Furthermore, the synthetic fatty acid resin is selected from at least one of KN8120P, KN3885P and KN3880P produced by Guangdong Kelisen Resin Co., Ltd.

[0020] Furthermore, the synthetic fatty acid resin is KN3880P.

[0021] The YQ528A toughness resin described in this invention is sourced from Foshan Hongyuan Chemical Co., Ltd.

[0022] Furthermore, the ultraviolet absorber is selected from at least one of the ultraviolet absorbers UV-400, UV384-2, UV-571, and UV-1130 produced by Nanjing Milan Chemical Co., Ltd.

[0023] Furthermore, the ultraviolet absorber is ultraviolet absorber UV-1130.

[0024] Furthermore, the light stabilizer is selected from at least one of the light stabilizers UV5151, UV123, UV292 and UV1130 produced by Nanjing Milan Chemical Co., Ltd.

[0025] Furthermore, the light stabilizer is light stabilizer UV5151.

[0026] Furthermore, the leveling agent is a polyether-modified silicone oil.

[0027] Furthermore, the polyether-modified silicone oil is an ABA-type block polyether-modified silicone oil.

[0028] Furthermore, the polyether-modified silicone oil is selected from XIAMETER. TM OFX-3667 silicone oil and DOWSIL TM At least one of the following: Q4-3669 silicone oil.

[0029] In the main agent of this invention, besides the synthetic fatty acid resin, functional resin, and hydroxyl acrylic resin affecting the gloss and weather resistance of the acrylic coating varnish, the inventors unexpectedly discovered that when using ABA-type block polyether modified silicone oil, especially XIAMETER... TM OFX-3667 silicone oil or DOWSIL TM When using Q4-3669 silicone oil, the gloss and weather resistance of the resulting acrylic coating varnish are significantly improved.

[0030] Furthermore, the adhesion promoter is selected from at least one of Tech-74510, Tech-7300 and Tech-7205N produced by Shanghai Tiger Polymer Technology Co., Ltd.

[0031] Furthermore, the adhesion promoter is Tech-74510.

[0032] Further, solvent A is a mixture of ethylene glycol ethyl ether acetate and propylene glycol methyl ether acetate in a mass ratio of 1:2-4.

[0033] Furthermore, solvent A is a mixture of ethylene glycol ethyl ether acetate and propylene glycol methyl ether acetate in a mass ratio of 1:3.

[0034] Furthermore, the isocyanate is an aliphatic isocyanate.

[0035] Furthermore, the aliphatic isocyanate is selected from at least one of aliphatic isocyanate monomers and aliphatic isocyanate polymers.

[0036] Furthermore, the aliphatic isocyanate monomer is selected from at least one of tetramethylene 1,4-diisocyanate and hexamethylene 1,6-diisocyanate.

[0037] Furthermore, the aliphatic isocyanate polymer is selected from at least one of aliphatic isocyanate dimers and aliphatic isocyanate trimers.

[0038] Furthermore, the isocyanate is an aliphatic isocyanate trimer.

[0039] Furthermore, the aliphatic isocyanate trimer is selected from at least one of Covestro Desmodur N3390 and Covestro Desmodur N3600.

[0040] Furthermore, the aliphatic isocyanate trimer is Covestro Desmodur N3390.

[0041] Furthermore, the solvent B is selected from at least one of ethyl acetate, butyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

[0042] Furthermore, the solvent B is ethyl acetate.

[0043] Further, the diluent is a mixture of xylene, ethylene glycol ethyl ether acetate, butyl acetate and propylene glycol methyl ether acetate in a mass ratio of 1-2:1-2:2-3:3-6.

[0044] Furthermore, the diluent is a mixture of xylene, ethylene glycol ethyl ether acetate, butyl acetate, and propylene glycol methyl ether acetate in a mass ratio of 1.5:1.5:2:5.

[0045] A second aspect of this invention provides a method for preparing a high-gloss acrylic coating varnish, comprising the following steps:

[0046] (1) The hydroxyl acrylic resin, synthetic fatty acid resin, functional resin, ultraviolet absorber, light stabilizer, leveling agent, adhesion promoter and solvent A are stirred and mixed evenly to obtain the main agent;

[0047] (2) Mix isocyanate and solvent B evenly to obtain a curing agent;

[0048] (3) When using, stir the main agent, curing agent and diluent evenly.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] This invention utilizes a combination of specific hydroxyl acrylic resin, synthetic fatty acid resin, functional resin, and leveling agent to produce an acrylic coating varnish. When applied to PC / ABS parts electroplated with bright chrome, the varnish film exhibits a gloss level of 91-95 at 60°, a hardness of H-2H, adhesion grade of 0, a defect size rating of 0 after 840 hours of cyclic corrosion testing, a gloss retention rate of 92.6-95.7% after 2000 hours of weathering testing, and a mass loss of less than 10mg after 1000 abrasion tests. Detailed Implementation

[0051] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0052] In the context of illustrating and explaining the purpose of the present invention through the following examples, the components of the compositions are explained using parts by mass as a general standard. Unless otherwise specified, for the sake of brevity, "parts" and "parts by mass" are used interchangeably in the embodiments of the present invention.

[0053] Exemplary sources of raw materials in the following embodiments and comparative examples are shown in Table 1:

[0054] Table 1

[0055]

[0056] Examples 1-3 provide a high-gloss acrylic coating varnish, the composition of which is shown in Table 2:

[0057] Table 2

[0058]

[0059] The preparation method of the high-gloss acrylic coating varnish described in Examples 1-3 is as follows: (1) Hydroxy acrylic resin, synthetic fatty acid resin, functional resin, ultraviolet absorber, light stabilizer, leveling agent, adhesion promoter and solvent A are stirred and mixed evenly to obtain the main agent;

[0060] (2) Mix isocyanate and solvent B evenly to obtain a curing agent;

[0061] (3) When using, stir the main agent, curing agent and diluent evenly.

[0062] Comparative Examples 1-5 provide a high-gloss acrylic coating varnish, the composition of which is shown in Table 3:

[0063] Table 3

[0064]

[0065]

[0066] The preparation method of the high-gloss acrylic coating varnishes described in Comparative Examples 1-5 is as follows:

[0067] (1) Mix hydroxy acrylic resin, synthetic fatty acid resin, organosilicon modified acrylic resin or functional resin, ultraviolet absorber, light stabilizer, leveling agent, adhesion promoter and solvent A evenly to obtain the main agent;

[0068] (2) Mix isocyanate and solvent B evenly to obtain a curing agent;

[0069] (3) When using, stir the main agent, curing agent and diluent evenly.

[0070] Test case

[0071] High-gloss acrylic varnishes of Examples 1-3 and Comparative Examples 1-5, with a thickness of 15 μm, were sprayed onto the surface of electroplated bright chrome PC / ABS parts. The parts were then baked at 70°C for 60 min, and performance tests were conducted. The test items, methods / standards are as follows:

[0072] 1. Gloss: GB / T 9754-2007;

[0073] 2. Hardness: GB / T 6739-2022;

[0074] 3. Adhesion: GB / T 9286-2021;

[0075] 4. Corrosion resistance: GB / T 31588.1-2015, cycle B, total 840h;

[0076] 5. Weather resistance: GB / T 1865-2009, Method 1, for a total of 2000h, evaluate its gloss retention rate;

[0077] 6. Wear resistance: GB / T 1768-2006, CS-10 wheel, 1000 cycles in total.

[0078] The test results are shown in Table 4:

[0079] Table 4

[0080]

[0081] As can be seen from the test data in Table 4, the combined use of PAR-1153-75 and PAR-1137-75 yields the best results in the selection of hydroxyl acrylic resins; replacing PAR-1153-75 and PAR-1137-75 with... The acrylic coating varnish obtained using 1907BA-75 exhibits reduced gloss, hardness, adhesion, corrosion resistance, weather resistance, and abrasion resistance.

[0082] In the process of selecting functional resins, replacing YQ528A with silicone-modified acrylic resin resulted in a decrease in the hardness and adhesion of the resulting acrylic coating varnish; replacing it with YQ206B resulted in a decrease in the hardness, adhesion, corrosion resistance, weather resistance, and abrasion resistance of the resulting acrylic coating varnish.

[0083] Comparative Example 4 shows that hydroxyl acrylic resin, synthetic fatty acid resin and functional resin affect the gloss, hardness, adhesion, corrosion resistance, weather resistance and abrasion resistance of acrylic coating varnish.

[0084] In the selection of leveling agents, XIAMETER will be used. TMReplacing OFX-3667 silicone oil with KF96-350cs silicone oil resulted in a decrease in the gloss, hardness, corrosion resistance, and weather resistance of the resulting acrylic coating varnish.

[0085] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A high-gloss acrylic coating varnish, characterized in that, It includes a main agent, a curing agent, and a diluent in a mass ratio of 10:6-7:10; the main agent comprises the following raw materials in parts by mass: 40-60 parts hydroxy acrylic resin, 5-15 parts synthetic fatty acid resin, 5-15 parts functional resin, 0.5-3 parts ultraviolet absorber, 0.5-2 parts light stabilizer, 0.2-1 parts leveling agent, 0.2-1 parts adhesion promoter, and 20-40 parts solvent A; The curing agent comprises the following raw materials in parts by weight: 60-80 parts isocyanate and 20-40 parts solvent B; The hydroxy acrylic resin is selected from at least one of PAR-1153-75 and PAR-1137-75; The functional resin is YQ528A toughness resin; The mass ratio of the hydroxyl acrylic resin, synthetic fatty acid resin and functional resin is 5-7:1:1-2; The leveling agent is a polyether-modified silicone oil; the polyether-modified silicone oil is an ABA-type block polyether-modified silicone oil.

2. The high-gloss acrylic coating varnish according to claim 1, characterized in that, The hydroxy acrylic resin is a mixture of PAR-1153-75 and PAR-1137-75 in a mass ratio of 1:3-5.

3. The high-gloss acrylic coating varnish according to claim 1, characterized in that, The synthetic fatty acid resin is selected from at least one of KN8120P, KN3885P and KN3880P.

4. The high-gloss acrylic coating varnish according to claim 1, characterized in that, The ultraviolet absorber is selected from at least one of ultraviolet absorber UV-400, ultraviolet absorber UV384-2, ultraviolet absorber UV-571 and ultraviolet absorber UV-1130; the light stabilizer is selected from at least one of light stabilizer UV5151, light stabilizer UV123, light stabilizer UV292 and light stabilizer UV1130.

5. The high-gloss acrylic coating varnish according to claim 1, characterized in that, The polyether-modified silicone oil is selected from at least one of XIAMETER™ OFX-3667 silicone oil and DOWSIL™ Q4-3669 silicone oil.

6. The high-gloss acrylic coating varnish according to claim 1, characterized in that, The adhesion promoter is selected from at least one of Tech-74510, Tech-7300 and Tech-7205N.

7. The method for preparing the high-gloss acrylic coating varnish according to any one of claims 1-6, characterized in that, Includes the following steps: (1) Stir and mix hydroxy acrylic resin, synthetic fatty acid resin, functional resin, ultraviolet absorber, light stabilizer, leveling agent, adhesion promoter and solvent A evenly to obtain the main agent; (2) Mix isocyanate and solvent B evenly to obtain a curing agent; (3) When using, stir the main agent, curing agent and diluent evenly.

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