High-gloss acrylic acid coating varnish and preparation method thereof

Abstract

The invention belongs to the technical field of varnish, and particularly relates to high-gloss acrylic acid coating varnish and a preparation method thereof. The high-gloss acrylic acid 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 is prepared from the following raw materials in parts by mass: 40 to 60 parts of hydroxy acrylic resin, 5 to 15 parts of synthetic fatty acid resin, 5 to 15 parts of functional resin, 0.5 to 3 parts of ultraviolet light absorber, 0.5 to 2 parts of light stabilizer, 0.2 to 1 part of flatting agent, 0.2 to 1 part of adhesion promoter and 20 to 40 parts of solvent A; the curing agent is prepared from the following raw materials in parts by mass: 60 to 80 parts of isocyanate and 20 to 40 parts of solvent B; and the functional resin is YQ528A toughness resin. The high-gloss acrylic acid coating varnish provided by the invention has the characteristics of high gloss, high adhesive force, high hardness, high wear resistance, high corrosion resistance and high weather resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of varnishes, and in particular relates to a high-gloss acrylic coating varnish and a preparation method thereof. Background Art

[0002] PC (polycarbonate) / ABS (polyacrylonitrile) materials have been widely used in automotive exterior manufacturing and handicraft manufacturing due to their excellent properties such as light weight and impact resistance. To improve their decorative properties, they are usually vacuum metallized on their surfaces and then varnished to give them a metallic luster. The use of varnish is crucial, affecting the gloss and service life of metal-coated PC / ABS material products.

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

[0004] There are few reports on varnishes for PC / ABS automotive exterior door handles in the prior art. A closely related prior art, Chinese Patent Publication No. CN 115926556 B, discloses a protective varnish for selective electroplating of automotive grilles, as well as its preparation and use methods. The varnish comprises a basecoat and a topcoat. The basecoat's primary resin is amino acrylic resin, providing excellent adhesion to various substrates and interlayer adhesion with the topcoat. The topcoat's primary resin is fluororesin, providing high weather resistance and a variety of conventional physical resistance properties. The combined properties of the basecoat and topcoat enhance corrosion resistance, meeting the performance testing requirements of automotive body coatings from OEMs. However, this technical solution utilizes separate basecoat and topcoat varnish components, making the design relatively complex.

[0005] In view of this, 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 that can be used for PC / ABS material automobile door exterior handles. Summary of the Invention

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

[0007] A second aspect of the present invention provides a method for preparing a high-gloss acrylic coating varnish.

[0008] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] A first aspect of the present 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 a hydroxy acrylic resin, 5-15 parts of a synthetic fatty acid resin, 5-15 parts of a functional resin, 0.5-3 parts of a UV absorber, 0.5-2 parts of a light stabilizer, 0.2-1 parts of a leveling agent, 0.2-1 parts of an adhesion promoter, and 20-40 parts of a solvent A;

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

[0011] The functional resin is YQ528A tough resin.

[0012] Taking into account the application scenarios of the acrylic coating varnish of the present invention, the exterior door handles of automobiles made of PC / ABS materials, in addition to the aesthetic requirements (good gloss), also need to have good wear resistance to avoid wear due to the frequent use of the exterior door handles. During the experiment, the inventor unexpectedly discovered that by adding a specific YQ528A tough resin, which works together with a hydroxy acrylic resin and a synthetic fatty acid resin, the resulting acrylic coating varnish has better comprehensive performance than silicone hydroxy acrylates and high-grade saturated polyester resins. While having good gloss, it also has good hardness, adhesion, corrosion resistance, weather resistance and wear resistance.

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

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

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

[0016] Furthermore, the hydroxy 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 hydroxylated acrylic resin is a mixture of PAR-1153-75 and PAR-1137-75 in a mass ratio of 1:3-5.

[0018] The hydroxy acrylic resin used in the present invention comes from Guangdong Jiayuan New Materials Co., Ltd. After trial and error, 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 after weathering test is greater than 95%.

[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 tough resin described in the present invention is sourced from Foshan Hongyuan Chemical Co., Ltd.

[0022] Furthermore, 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 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 light stabilizer UV5151, light stabilizer UV123, light stabilizer UV292 and light stabilizer UV1130 produced by Nanjing Milan Chemical Co., Ltd.

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

[0026] Furthermore, the leveling agent is 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 Q4-3669 silicone oils.

[0029] In addition to the synthetic fatty acid resin, functional resin and hydroxy acrylic resin in the main agent of the present invention, which affect the glossiness and weather resistance of acrylic coating varnish, the inventors unexpectedly found that when ABA type block polyether modified silicone oil, especially XIAMETER TM OFX-3667 silicone oil or DOWSIL TM When Q4-3669 silicone oil is added, the glossiness and weather resistance of the obtained 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] Furthermore, the 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, the 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 an aliphatic isocyanate monomer and an aliphatic isocyanate polymer.

[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 an aliphatic isocyanate dimer and an aliphatic isocyanate trimer.

[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] 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 1-2:1-2:2-3:3-6.

[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 the present invention provides a method for preparing a high-gloss acrylic coating varnish, comprising the following steps:

[0046] (1) mixing hydroxy acrylic resin, synthetic fatty acid resin, functional resin, ultraviolet absorber, light stabilizer, leveling agent, adhesion promoter and solvent A to obtain a main agent;

[0047] (2) stirring and mixing the isocyanate and solvent B to obtain a curing agent;

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

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

[0050] The acrylic coating varnish obtained by the present invention is prepared by combining a specific hydroxy acrylic resin, a synthetic fatty acid resin, a functional resin and a leveling agent. When applied to PC / ABS parts electroplated with bright chrome, the paint film has a glossiness of 91-95 at 60°, a hardness of H-2H, and an adhesion level of 0. After a cyclic corrosion test for 840 hours, the defect size rating reaches level 0. After a weathering test for 2000 hours, the gloss retention rate reaches 92.6-95.7%. After an abrasion resistance test for 1000 times, the mass loss is less than 10 mg. DETAILED DESCRIPTION

[0051] To more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments. It should be understood that the embodiments described are only a portion of the present invention, not all of the embodiments. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0052] In the following examples, the components of the composition are generally described in parts by mass. Unless otherwise specified, for the sake of simplicity, the "parts" in the examples of the present invention have the same meaning as parts by mass.

[0053] The exemplary sources of the raw materials in the following examples 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 to obtain a main agent;

[0060] (2) stirring and mixing the isocyanate and solvent B to obtain a curing agent;

[0061] (3) When using, mix 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 varnish described in Comparative Examples 1-5 is as follows:

[0067] (1) mixing 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 to obtain a main agent;

[0068] (2) stirring and mixing the isocyanate and solvent B to obtain a curing agent;

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

[0070] Test Case

[0071] The high-gloss acrylic coating varnish described in Examples 1-3 and Comparative Examples 1-5 was sprayed on the surface of a PC / ABS part electroplated with bright chrome to a thickness of 15 μm, and baked at 70° C. for 60 min. Performance tests were then conducted. The test items, methods, and 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, 2000h in total, evaluate gloss retention;

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

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

[0079] Table 4

[0080]

[0081] From the test data in Table 4, it can be seen that in the selection process of hydroxylated acrylic resin, the best effect is achieved when PAR-1153-75 and PAR-1137-75 are used together; 1907BA-75, the gloss, hardness, adhesion, corrosion resistance, weather resistance and abrasion resistance of the obtained acrylic coating varnish are reduced.

[0082] In the process of selecting functional resins, when YQ528A is replaced with silicone-modified acrylic resin, the hardness and adhesion of the obtained acrylic coating varnish decrease; when it is replaced with YQ206B, the hardness, adhesion, corrosion resistance, weather resistance and wear resistance of the obtained acrylic coating varnish decrease.

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

[0084] When selecting a leveling agent, consider XIAMETER TMWhen OFX-3667 silicone oil was replaced with KF96-350cs silicone oil, the gloss, hardness, corrosion resistance and weather resistance of the obtained acrylic coating varnish decreased.

[0085] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A high gloss acrylic coating varnish, characterized in that: The invention comprises 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 of hydroxy 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; 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 tough resin.

2. The high-gloss acrylic coating varnish according to claim 1, characterized in that: The hydroxy acrylic resin is selected from at least one of PAR-1153-75, PAR-1132-70, PAR-1137-75, and PAR-1139-80.

3. The high-gloss acrylic coating varnish according to claim 2, 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.

4. 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.

5. The high-gloss acrylic coating varnish according to claim 1, characterized in that: The mass ratio of the hydroxy acrylic resin, the synthetic fatty acid resin and the functional resin is 5-7:1:1-2.

6. 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.

7. The high-gloss acrylic coating varnish according to claim 1, characterized in that: The leveling agent is polyether modified silicone oil; the polyether modified silicone oil is ABA type block polyether modified silicone oil.

8. The high-gloss acrylic coating varnish according to claim 7, characterized in that: The polyether modified silicone oil is selected from XIAMETER TM OFX-3667 silicone oil and DOWSIL TM At least one of Q4-3669 silicone oils.

9. 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.

10. The method for preparing the high-gloss acrylic coating varnish according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) mixing hydroxy acrylic resin, synthetic fatty acid resin, functional resin, ultraviolet absorber, light stabilizer, leveling agent, adhesion promoter and solvent A to obtain a main agent; (2) stirring and mixing the isocyanate and solvent B to obtain a curing agent; (3) When using, mix the main agent, curing agent and diluent evenly.

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