High-hardness anti-scraping water-based two-component black finish paint as well as preparation method and application thereof

Abstract

The invention relates to the technical field of coatings, in particular to the field of IPC C09D175, and more particularly relates to a high-hardness anti-scraping water-based two-component black finish paint as well as a preparation method and application thereof. Comprising a component A and a component B. The component A comprises, by weight, 60-90% of a hydroxyl acrylic emulsion, 1-5% of matting powder, 1-5% of an anti-scratch auxiliary agent, 1-5% of a rheological agent and the balance auxiliary agents. And the component B comprises a water dispersible isocyanate curing agent. The hardness of the paint film can reach 2H (Chinese pencil), and the paint film also has excellent physical stability.

Description

Technical Field

[0001] The present invention relates to the field of coating technology, in particular to the field of IPC C09D175, and more specifically to a high-hardness, scratch-resistant water-based two-component black topcoat and a preparation method and use thereof. Background Art

[0002] Matte coatings are usually easier to hide stains and scratches than glossy paints due to their surface treatment, because their surface reflects less light, and scratches and stains will not be as obvious as glossy paints. In addition, matte coatings are usually more resistant to staining because their surface treatment can reduce the appearance of stains and scratches. Pure black matte coatings are widely used, especially in the fields of high-end automobiles and electronic products. It can not only enhance the appearance and texture of items, but also meet consumers' needs for low-key, luxurious and personalized. However, pure black matte coatings do tend to leave obvious visual marks when slightly scratched, and it is urgent to solve the technical difficulties of low hardness and scratch resistance of water-based two-component black topcoat.

[0003] Chinese invention patent CN 109467994A discloses a two-component high-hardness scratch-resistant water-based matte topcoat and its preparation method, wherein component B is water-based polyisocyanate, and component A is composed of cross-linked acrylic resin, polysiloxane defoamer, silicone leveling and slip agent, polyether modified wetting agent, polymer dispersant, silica matting agent, dipropylene glycol methyl ether, dipropylene glycol butyl ether, polyurethane associative rheological additive and water, which effectively improves the water resistance and chemical resistance of water-based wood paint, and improves the hardness, fullness, feel and anti-adhesion performance of the paint film. However, this invention is only applicable to wood, and the hardness does not reach 2H. Summary of the invention

[0004] The first aspect of the present invention provides a high-hardness, scratch-resistant, water-based two-component black topcoat, comprising a component A and a component B. The component A comprises, by weight percentage: 60-90% of a hydroxylated acrylic emulsion, 1-5% of a matting powder, 1-5% of an anti-scratch additive, 1-5% of a rheological agent, and the balance is made up of additives; the component B comprises a water-dispersible isocyanate curing agent.

[0005] Preferably, the curing agent is purchased from Guangdong Top, model: 817.

[0006] Preferably, the component A comprises, by weight percentage: 60-80% hydroxy acrylic emulsion, 1-4% matting powder, 1-4% anti-scratch additive, 1-4% rheological agent, and the balance is made up of additives; and the component B comprises a water-dispersible isocyanate curing agent.

[0007] The auxiliary agent in the component A includes at least one of a pH regulator, a wetting and dispersing agent, a leveling agent, a defoaming agent, a film-forming agent, deionized water, a humectant, a bactericide, a thickener, and a color paste, and the component B includes a solvent and / or a water absorbent.

[0008] Preferably, the auxiliary agents in the component A include a pH regulator, a wetting and dispersing agent, a leveling agent, a defoaming agent, a film-forming agent, deionized water, a humectant, a bactericide, a thickener, and a color paste; and the component B includes a solvent and a water absorbent.

[0009] The film-forming aid includes at least one of dipropylene glycol butyl ether DPnB, propylene glycol n-butyl ether PNB, dipropylene glycol methyl ether DPM, and propylene glycol phenyl ether PPH.

[0010] Preferably, the film-forming aid includes at least one of dipropylene glycol butyl ether DPnB, propylene glycol n-butyl ether PNB, and dipropylene glycol methyl ether DPM.

[0011] The matting powder includes at least one of ultrafine silicon dioxide, micro powder wax and wax slurry.

[0012] Preferably, the matting powder comprises ultrafine silica, and more preferably, the amorphous ultrafine silica of model SY7000.

[0013] Preferably, the moisturizing agent includes JY-WEPO (Jingyang).

[0014] The pH adjuster includes at least one of tris(hydroxymethyl)aminomethane (TRISAMINO), 2-amino-2-methyl-1,3-propanediol (AMPD), 2-amino-2-ethyl-1,3-propanediol (AEPD VOX 1000); 2-amino-2-methyl-1-propanol (AMP-95), 3-amino-4-octanol (CORRGUARD EXT), dimethylamino-2-methyl-1-propanol (DMAMP 80), diisopropanolamine (DIPA) and TIPA (triisopropanolamine).

[0015] Preferably, the wetting and dispersing agent includes at least one of the following models: BYK190, BYK2055, NOPCALL-5180, DISPERS-755W, SN-1710, and SN-1729.

[0016] Further preferably, the wetting and dispersing agent includes at least one of the following types: SN-1710, SN-1729.

[0017] Preferably, the leveling agent includes at least one of the following types: BYK-346, BYK-345, TEGO270, TEGO4100, SURFYNOL465, SURFYNOL104E.

[0018] Further preferably, the leveling agent includes at least one of the following types: BYK-346, BYK-345, TEGO270, TEGO4100.

[0019] Preferably, the pH adjuster includes at least one of tris(hydroxymethyl)aminomethane (TRISAMINO), 2-amino-2-methyl-1,3-propanediol (AMPD), 2-amino-2-ethyl-1,3-propanediol (AEPD VOX 1000); and 2-amino-2-methyl-1-propanol (AMP-95).

[0020] The defoaming agent includes an organic silicone polyether copolymer, preferably at least one of the following models: Tego902W, Tego825, and Tego904W.

[0021] The anti-scratch additive includes a wax emulsion, and the wax emulsion includes at least one of the following models: Michem Guard 1350, Michem Emulsion 64422, and Jingzhijie W-801A.

[0022] Preferably, the anti-scratch additive also includes Yunchu New Material TD138.

[0023] Preferably, the bactericide comprises an organic titanate complex, preferably at least one of the following models of Hoffmann: AA, GBA, GBO, AA-75, AA-65, AA-105, DC, BEAT, BTP, TE, TnBT, KTM, TOT, TPT.

[0024] The hydroxyl acrylic emulsion comprises a first hydroxyl acrylic emulsion and a second hydroxyl acrylic emulsion, wherein the hydroxyl content of the first hydroxyl acrylic emulsion is 1-3 wt %, and the hydroxyl content of the second hydroxyl acrylic emulsion is 2.5-4.2 wt %.

[0025] The hydroxyl content of the first hydroxylated acrylic emulsion is 1.2-2 wt %, and the hydroxyl content of the second hydroxylated acrylic emulsion is 3-4 wt %.

[0026] The weight ratio of the first hydroxylated acrylic emulsion to the second hydroxylated acrylic emulsion is (1.5-3.8):1.

[0027] The weight ratio of the first hydroxylated acrylic emulsion to the second hydroxylated acrylic emulsion is (2.5-3.8):1.

[0028] The applicant has found that by compounding two acrylic emulsions with different hydroxyl contents, the hardness of the paint film can be increased to H (Chinese pencil) while maintaining the dispersion of the color paste in the system. It may be that the acrylic segments with different hydroxyl contents form a denser cross-interpenetrating network during the curing process. Further research found that when the weight ratio of the first hydroxyl acrylic emulsion to the second hydroxyl acrylic emulsion is (1.5-3.8): 1, the hardness of the paint film can be further increased to 2H (Chinese pencil). It may be that the specific ratio reduces the differential phase of the two segment polymers in the system, thereby promoting the dispersion of the matting agent in the system.

[0029] The thickener includes a first thickener and a second thickener, wherein the first thickener includes a polyether polyol thickener, and the second thickener includes a polyurethane thickener.

[0030] Preferably, the first thickener includes at least one of the following models: Deqian 50D, Deqian 299, and Haimings 350D.

[0031] Preferably, the second thickener includes at least one of the following models: JETHOUS 76 from Yuansheng New Materials and Haimings 299.

[0032] The color paste includes water-based color paste.

[0033] The solvent includes at least one of PMA (ethyl 3-ethoxypropionate), EPMA (propylene glycol methyl ether acetate), and PCE (polyoxymethylene dimethyl ether).

[0034] Preferably, the solvent comprises PMA (ethyl 3-ethoxypropionate).

[0035] Preferably, the color paste includes at least one of water-based iron yellow paste, water-based iron red paste, and water-based black paste.

[0036] Further preferably, the color paste includes at least one of the following models: Clariant E844-1, Clariant R131-01-CNYEL, Clariant B130-01-CN RED, Clariant N131-CN.

[0037] The rheological agent includes a modified sheet-like magnesium aluminum silicate.

[0038] Preferably, the rheological agent includes BYK-S482 produced by BYK of Germany.

[0039] A second aspect of the present invention provides a method for preparing a high-hardness, scratch-resistant, water-based two-component black topcoat, comprising the following steps:

[0040] S1, uniformly mixing the first hydroxy acrylic emulsion, the second hydroxy acrylic emulsion, a pH adjuster, a wetting and dispersing agent, a leveling agent, a defoaming agent, and a matting powder, which account for 40-70 wt % of the total amount of the first hydroxy acrylic emulsion;

[0041] S2, adding 80-95wt% of the total amount of the film-forming agent, deionized water, a moisturizer, a bactericide, and a first thickener and mixing them evenly;

[0042] S3, adding the remaining first hydroxy acrylic emulsion, anti-scratch additive, rheological agent, and color paste, and mixing evenly;

[0043] S4, adding the second thickener and the remaining film-forming agent, mixing evenly, to obtain component A;

[0044] S5, mixing the raw materials of component B uniformly to obtain component B.

[0045] Preferably, the method comprises the following steps:

[0046] S1, uniformly mixing the first hydroxy acrylic emulsion, the second hydroxy acrylic emulsion, a pH adjuster, a wetting and dispersing agent, a leveling agent, a defoaming agent, and a matting powder, which account for 50-70 wt% of the total amount of the first hydroxy acrylic emulsion;

[0047] S2, adding 90-95wt% of the total amount of the film-forming agent, deionized water, a moisturizer, a bactericide, and a first thickener and mixing them evenly;

[0048] S3, adding the remaining first hydroxy acrylic emulsion, anti-scratch additive, rheological agent, and color paste, and mixing evenly;

[0049] S4, adding the second thickener and the remaining film-forming agent, mixing evenly, to obtain component A;

[0050] S5, mixing the raw materials of component B uniformly to obtain component B.

[0051] Preferably, the water absorbent is G-180 (Shanghai Baiyin Chemical).

[0052] The viscosity of the A component at 25° C. is 50-100 KU.

[0053] Preferably, the viscosity of component A at 25° C. is 50-80 KU.

[0054] Further preferably, the viscosity of the component A at 25° C. is 70 KU.

[0055] The weight ratio of the first hydroxylated acrylic emulsion to the second hydroxylated acrylic emulsion in S1 is 3:(1-3).

[0056] Preferably, the weight ratio of the first hydroxylated acrylic emulsion to the second hydroxylated acrylic emulsion in S1 is 3:(1.5-3).

[0057] Further preferably, the weight ratio of the first hydroxylated acrylic emulsion to the second hydroxylated acrylic emulsion in S1 is 3:2.

[0058] The third aspect of the present invention provides a method for using a high-hardness, scratch-resistant water-based two-component black topcoat, comprising the following steps: configuring component A, component B, and deionized water into a coating in a weight ratio of 100:(10-30):(15-40), and spraying the coating.

[0059] Preferably, the method comprises the following steps: preparing a coating by mixing component A, component B and deionized water in a weight ratio of 100:20:25, and spraying the coating.

[0060] Preferably, the spraying is performed by manual spraying or reciprocating spraying.

[0061] Beneficial Effects

[0062] 1. By compounding two acrylic emulsions with different hydroxyl contents, the dispersion of the color paste in the system can be maintained while the hardness of the paint film can be increased to H (Chinese pencil).

[0063] 2. When the weight ratio of the first hydroxy acrylic emulsion to the second hydroxy acrylic emulsion is (1.5-3.8):1, the hardness of the paint film can be further improved to 2H (Chinese pencil).

[0064] 3. The thickener includes a first thickener and a second thickener, and the first thickener includes a polyether polyol thickener, and the second thickener includes a polyurethane thickener, which can improve the physical stability of the system.

[0065] 4. Rheological agents include modified flaky magnesium aluminum silicate, which can improve the anti-cracking, anti-adhesion and impact resistance of the paint film.

[0066] 5. In the preparation step S1, the weight ratio of the first hydroxylated acrylic emulsion to the second hydroxylated acrylic emulsion is limited to 3:(1.5-3), which can improve the preparation efficiency and the leveling performance. DETAILED DESCRIPTION

[0067] Example 1, Comparative Examples 1-2

[0068] A high-hardness, scratch-resistant, water-based two-component black topcoat, consisting of component A and component B. By weight percentage, the formula of component A is shown in Table 1, and the formula of component B is shown in Table 2:

[0069] Table 1

[0070]

[0071]

[0072] Table 2

[0073] Components Model(Manufacturer) Example 1 Comparative Example 1 Comparative Example 2 Solvents PMA (Jiangsu Sanmu Chemical) 12.2 12.2 12.2 Water absorbent G-180 (Shanghai Baiyin Chemical) 0.3 0.3 0.3 Curing agent 817 (Guangdong Top) 87.5 87.5 87.5

[0074] A high-hardness, scratch-resistant water-based two-component black topcoat, wherein the preparation methods of Example 1 and Comparative Example 1 are as follows:

[0075] S1, add the first hydroxy acrylic emulsion, which accounts for 54.5wt% of the total amount of the first hydroxy acrylic emulsion, the second hydroxy acrylic emulsion, and the dispersing machine speed to 500 rpm, and add pH adjuster, wetting dispersant, leveling agent, defoaming agent, and matting powder in sequence. After the addition is completed, wash the cylinder wall with an appropriate amount of deionized water, increase the speed to 1000 rpm and disperse for about 25 minutes. At the end of this stage, use a fineness plate to confirm that the fineness is ≤30μm;

[0076] S2, adding 93.3wt% of the total amount of the film-forming agent, deionized water, humectant, bactericide, and the first thickener, after the addition is completed, increasing the speed of the disperser to 1000 rpm, and the dispersion time is 5 minutes;

[0077] S3, keep the speed of the disperser at 1000 rpm, slowly add the remaining first hydroxy acrylic emulsion filtered by a 300-mesh filter, then add the anti-scratch additive, rheological agent, and black slurry in sequence. After the addition is completed, maintain the speed of the disperser at 1000 rpm and disperse for 10 minutes. At the end of this stage, use a fineness plate to confirm that the fineness is ≤30μm;

[0078] S4, reducing the speed of the disperser to 500 rpm, adding the second thickener and the remaining film-forming agent, mixing evenly, and adjusting the viscosity to 70 KU to obtain component A;

[0079] S5, add the solvent filtered by a 300-mesh filter in a static state, increase the speed of the disperser to 500 rpm, add the water absorbent, slowly add the curing agent, increase the speed to 900 rpm, and disperse for 15 minutes until it is uniform, thereby completing the preparation of component B.

[0080] The preparation method of comparative example 2 is the same as that of example 1, except that: S1, the first hydroxy acrylic emulsion, which accounts for 58.3wt% of the total amount of the first hydroxy acrylic emulsion, the second hydroxy acrylic emulsion, the speed of the disperser is increased to 500 rpm, and the pH regulator, wetting dispersant, leveling agent, defoaming agent, and matting powder are added in sequence. After the addition is completed, the cylinder wall is cleaned with an appropriate amount of deionized water, the speed is increased to 1000 rpm and dispersed for about 25 minutes. At the end of this stage, the fineness is confirmed to be ≤30μm using a fineness plate;

[0081] A method for using a high-hardness, scratch-resistant water-based two-component black topcoat comprises the following steps: preparing a coating with a weight ratio of 100:20:25 among a component A, a component B and deionized water, and spraying the coating manually.

[0082] Performance testing methods and data

[0083] The water-based two-component black topcoat prepared in the embodiment and the comparative example was subjected to performance testing, and the test items and data are listed in Table 3.

[0084] Table 3

[0085]

[0086]

[0087] It can be seen from Table 1 that after the construction of Example 1 is completed, it is baked at 40°C for 4h, then taken out and placed at room temperature, and cured for 7 days according to the national standard. The paint film hardness can reach 2H (China Pencil). For Comparative Example 1, the high hydroxyl emulsion uses Huaguoshan 4002L, and the paint film hardness can only reach H (China Pencil). For Comparative Example 2, the content of high hydroxyl emulsion A2270 is reduced by 5%, and the paint film hardness can only reach H (China Pencil).

Claims

1. A high-hardness, scratch-resistant water-based two-component black topcoat, characterized in that: The invention comprises component A and component B. Component A comprises, by weight percentage, 60-90% of hydroxy acrylic emulsion, 1-5% of matting powder, 1-5% of anti-scratch additive, 1-5% of rheological agent, and the balance is made up of additives; and component B comprises a water-dispersible isocyanate curing agent.

2. The high-hardness, scratch-resistant water-based two-component black topcoat according to claim 1, characterized in that: The auxiliary agent in the component A includes at least one of a pH regulator, a wetting and dispersing agent, a leveling agent, a defoaming agent, a film-forming agent, deionized water, a humectant, a bactericide, a thickener, and a color paste, and the component B includes a solvent and / or a water absorbent.

3. The high-hardness, scratch-resistant water-based two-component black topcoat according to claim 2, characterized in that: The hydroxyl acrylic emulsion comprises a first hydroxyl acrylic emulsion and a second hydroxyl acrylic emulsion, wherein the hydroxyl content of the first hydroxyl acrylic emulsion is 1-3 wt %, and the hydroxyl content of the second hydroxyl acrylic emulsion is 2.5-4.2 wt %.

4. The high-hardness, scratch-resistant water-based two-component black topcoat according to claim 3, characterized in that: The weight ratio of the first hydroxylated acrylic emulsion to the second hydroxylated acrylic emulsion is (1.5-3.8):

1.

5. The high-hardness, scratch-resistant water-based two-component black topcoat according to claim 4, characterized in that: The thickener includes a first thickener and a second thickener, wherein the first thickener includes a polyether polyol thickener, and the second thickener includes a polyurethane thickener.

6. The high-hardness, scratch-resistant water-based two-component black topcoat according to claim 5, characterized in that: The rheological agent includes a modified sheet-like magnesium aluminum silicate.

7. A method for preparing the high-hardness, scratch-resistant water-based two-component black topcoat according to claim 6, characterized in that: The following steps are involved: S1, uniformly mixing the first hydroxy acrylic emulsion, the second hydroxy acrylic emulsion, a pH adjuster, a wetting and dispersing agent, a leveling agent, a defoaming agent, and a matting powder, which account for 40-70 wt % of the total amount of the first hydroxy acrylic emulsion; S2, adding 80-95wt% of the total amount of the film-forming agent, deionized water, a moisturizer, a bactericide, and a first thickener and mixing them evenly; S3, adding the remaining first hydroxy acrylic emulsion, anti-scratch additive, rheological agent, and color paste, and mixing evenly; S4, adding the second thickener and the remaining film-forming agent, mixing evenly, to obtain component A; S5, mixing the raw materials of component B uniformly to obtain component B.

8. The method for preparing the high-hardness, scratch-resistant water-based two-component black topcoat according to claim 7, characterized in that: The viscosity of the A component at 25° C. is 50-100 KU.

9. The method for preparing the high-hardness, scratch-resistant water-based two-component black topcoat according to claim 7 or 8, characterized in that: The weight ratio of the first hydroxylated acrylic emulsion to the second hydroxylated acrylic emulsion in S1 is 3:(1-3).

10. A method for using the high-hardness, scratch-resistant water-based two-component black topcoat according to claim 6, characterized in that: The following steps are involved: Mix component A, component B and deionized water in the ratio of 100:(10-30): The weight ratio of (15-40) is prepared into a coating and sprayed.

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