High-performance environment-friendly water-based paint, preparation method and application thereof

Abstract

The application discloses a kind of high-performance environment-friendly water-based paint and preparation method and application thereof, and is related to the technical field of coating.A kind of high-performance environment-friendly water-based paint, including the following mass parts of component: water-based resin 59-74 parts;Powder 10-20 parts;Crosslinking agent 0.1-0.5 parts;Functional adjuvant 0.5-0.9 parts;Solvent 15-20 parts;Powder includes bentonite and alumina, and the D50 particle size of bentonite is 25-30nm, the D50 particle size of alumina is 10-15nm.The water-based paint described in the application has excellent weather resistance, scratch resistance and mechanical properties, which is beneficial to low VOC emission, high weather resistance, strong scratch resistance and excellent decoration of the coating.

Description

Technical Field

[0001] This invention relates to the technical field of coatings, and in particular to a high-performance, environmentally friendly water-based coating, its preparation method, and its application. Background Technology

[0002] With increasing global awareness of environmental protection and increasingly stringent environmental regulations, the automotive coatings industry is gradually shifting from solvent-based to water-based coatings. However, current water-based automotive coatings on the market still have many shortcomings in terms of preparation processes and film performance, such as low film hardness, poor weather resistance, and difficulty in application.

[0003] Therefore, developing a high-performance, environmentally friendly water-based coating is of great significance. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a high-performance, environmentally friendly water-based coating, its preparation method, and its application. The water-based coating of this invention possesses excellent weather resistance, scratch resistance, and mechanical properties, which contributes to low VOC emissions, high weather resistance, strong scratch resistance, and excellent decorative properties, providing a green and efficient solution for the automotive coating industry.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect, the present invention provides a high-performance, environmentally friendly water-based coating, comprising the following components in parts by weight:

[0007] Waterborne resin 59-74 parts; powder 10-20 parts; crosslinking agent 0.1-0.5 parts; functional additives 0.5-0.9 parts; solvent 15-20 parts;

[0008] The powder comprises bentonite and alumina, wherein the D50 particle size of the bentonite is 25-30 nm and the D50 particle size of the alumina is 10-15 nm.

[0009] This invention uses water-based resin as the film-forming substrate for the coating. By adding powder, the small size and surface effects of nanoparticles are utilized to enhance the mechanical properties and weather resistance of the coating. Furthermore, the use of bentonite and alumina with specific particle sizes further enhances the coating's hardness, abrasion resistance, and scratch resistance. The addition of a crosslinking agent improves the coating's scratch resistance and adhesion, ensuring the stability and durability of the coating in complex environments. The addition of functional additives improves the coating's processing performance and film quality. Therefore, this invention, by adding powder, crosslinking agent, and functional additives to the water-based resin, effectively improves the coating's weather resistance, scratch resistance, and mechanical properties.

[0010] Preferably, the crosslinking agent includes hexamethoxyhydroxymethyl melamine and butylated melamine.

[0011] Preferably, the mass ratio of hexamethoxyhydroxymethyl melamine to butylated melamine is 1:(2-5).

[0012] This invention uses hexamethoxyhydroxymethyl melamine and butylated melamine as crosslinking agents, which can crosslink with water-based resins through chemical reaction to form a tight and stable three-dimensional (stereoscopic) network structure, which is beneficial to improving the hardness, scratch resistance, weather resistance and wear resistance of the coating.

[0013] Preferably, the high-performance environmentally friendly water-based coating comprises the following components in parts by weight:

[0014] 60-70 parts of water-based resin; 12-15 parts of powder; 0.2-0.4 parts of crosslinking agent; 0.6-0.8 parts of functional additives; 17-19 parts of solvent.

[0015] Preferably, the waterborne resin includes a waterborne acrylic resin or a polyurethane resin.

[0016] Preferably, the solvent is water.

[0017] This invention uses water as a solvent, resulting in extremely low VOC emissions, and the coating meets environmental protection requirements.

[0018] Preferably, the functional additives include at least one of thickeners, dispersants, defoamers, and film-forming aids.

[0019] More preferably, the thickener includes a cellulose-based thickener or a polyacrylic acid thickener; the dispersant includes dispersant TENLO70 or dispersant SDJ8005; the defoamer includes polydimethylsiloxane; and the film-forming aid includes at least one of Texanol ester, Coasol, and Nexcoat795.

[0020] Secondly, the present invention also provides a method for preparing a high-performance environmentally friendly water-based coating, comprising the following steps:

[0021] (1) Mix the powder with water-based resin, half of the solvent and functional additives evenly to obtain a pre-dispersion;

[0022] (2) Mix the pre-dispersed liquid with the other half of the solvent and crosslinking agent evenly to obtain a high-performance environmentally friendly water-based coating.

[0023] Thirdly, the present invention also provides an application of a high-performance, environmentally friendly water-based coating in automobiles.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] The high-performance, environmentally friendly water-based coating described in this invention can not only meet the automotive coating industry's demand for environmentally friendly, high-performance coatings, but also promote the green transformation and sustainable development of the coating industry, and gradually replace traditional solvent-based coatings, becoming the mainstream product in the automotive coating market. Detailed Implementation

[0026] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments, but the scope of protection and implementation of the present invention are not limited thereto.

[0027] Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0028] Examples 1-11

[0029] The embodiments of the high-performance environmentally friendly water-based coating and its preparation method described in this invention are shown in Table 1.

[0030] The preparation method of the high-performance environmentally friendly water-based coating includes the following steps:

[0031] (1) Put the powder into a container, then add the dispersant, half of the defoamer and half of the solvent, disperse it in a high-speed mixer for 10 minutes, and then shake it in a high-speed shaker for 1 hour to obtain a pre-dispersion liquid.

[0032] (2) Add the pre-dispersed liquid to the aqueous resin, then add the thickener, film-forming aid and the remaining half of the defoamer and mix. Then disperse for 30 minutes with a high-speed mixer to obtain the nanocomposite emulsion.

[0033] (3) Add the crosslinking agent to the nanocomposite emulsion. The mass ratio of the crosslinking agent to the nanocomposite emulsion is 0.5:1. Stir and mix at 30°C, and add the remaining half of the solvent at any time to adjust the viscosity to 25S to obtain a high-performance environmentally friendly water-based coating.

[0034] Comparative Examples 1-6

[0035] The only difference between the comparative examples and the embodiments is the type and ratio of components, as shown in Table 2.

[0036] In the components described in each embodiment and comparative example:

[0037] The waterborne resin 1 is a waterborne acrylic resin, model LB-1015, manufactured by Shenzhen Lanbo Environmental Protection Technology Co., Ltd.

[0038] The water-based resin 2 is a polyurethane resin, model LB-80, manufactured by Shenzhen Lanbo Environmental Protection Technology Co., Ltd.

[0039] The powder 1 includes bentonite and alumina, and the D50 particle size of bentonite is 25nm and the D50 particle size of alumina is 10nm.

[0040] The powder 2 includes bentonite and alumina, and the D50 particle size of bentonite is 25nm and the D50 particle size of alumina is 15nm.

[0041] The powder 3 includes bentonite and alumina, and the D50 particle size of bentonite is 30nm and the D50 particle size of alumina is 10nm.

[0042] The powder 4 includes bentonite and alumina, and the D50 particle size of bentonite is 30nm and the D50 particle size of alumina is 15nm.

[0043] The powder 5 includes bentonite and alumina, and the D50 particle size of bentonite is 15nm and the D50 particle size of alumina is 10nm.

[0044] The powder 6 includes bentonite and alumina, and the D50 particle size of the bentonite is 25 nm and the D50 particle size of the alumina is 25 nm.

[0045] The powder 7 includes bentonite;

[0046] The powder 8 includes aluminum oxide;

[0047] The powder 9 comprises bentonite and silicon dioxide;

[0048] The powder 10 comprises silicon dioxide and aluminum oxide.

[0049] The crosslinking agent 1 is hexamethoxyhydroxymethyl melamine;

[0050] The crosslinking agent 2 includes hexamethoxyhydroxymethyl melamine and butylated melamine, and the mass ratio of hexamethoxyhydroxymethyl melamine to butylated melamine is 1:2;

[0051] The crosslinking agent 3 includes hexamethoxyhydroxymethyl melamine and butylated melamine, and the mass ratio of hexamethoxyhydroxymethyl melamine to butylated melamine is 1:3;

[0052] The crosslinking agent 4 includes hexamethoxyhydroxymethyl melamine and butylated melamine, and the mass ratio of hexamethoxyhydroxymethyl melamine to butylated melamine is 1:4;

[0053] The crosslinking agent 5 includes hexamethoxyhydroxymethyl melamine and butylated melamine, and the mass ratio of hexamethoxyhydroxymethyl melamine to butylated melamine is 1:5.

[0054] The functional additives include thickeners, dispersants, defoamers, and film-forming aids, with a mass ratio of 1:1:1:1;

[0055] The thickener is hydroxyethyl cellulose, model 250HBR, manufactured by Mairui New Materials; the dispersant is dispersant SDJ8005, manufactured by Guangdong Dingjia New Materials Technology Co., Ltd.; the defoamer is polydimethylsiloxane, manufactured by Foshan Sirunbao Biotechnology Co., Ltd.; and the film-forming aid is Texanol ester, manufactured by Eastman.

[0056] The solvent is deionized water.

[0057] Unless otherwise specified, all components and raw materials used in the embodiments and comparative examples of this invention are commercially available, and the same type of components and raw materials are used in each parallel experiment.

[0058] Table 1

[0059]

[0060]

[0061] Table 2

[0062]

[0063]

[0064] To verify the performance of the high-performance environmentally friendly water-based coating described in this invention, the high-performance environmentally friendly water-based coatings prepared in each embodiment and comparative example were sprayed onto tinplate with a coating thickness of 25±um and baked at 60℃ for 30min to obtain pre-coated plate samples, which were used as performance evaluation tests.

[0065] Performance testing methods:

[0066] 1. Gloss: Tested according to GB / T9754-2007 standard.

[0067] 2. Hardness: Tested according to GB / T6739-2006 standard. The higher the hardness grade, the greater the hardness.

[0068] 3. Adhesion: Tested according to GB / T9286-1998 standard. The lower the adhesion grade, the better the adhesion.

[0069] 4. Scratch resistance: Tested by Nano Indenter XP (MTS Inc., USA) with a load of 1mN.

[0070] 5. Salt spray resistance: Tested according to ISO9227-2012 standard.

[0071] 6. VOC: Tested in accordance with GB / T23985-2009 standard.

[0072] 7. Abrasion resistance: The surface of the coating is abraded using RCA paper tape, manufactured by Norman Tool.

[0073] The performance parameters obtained from the above tests are shown in Tables 3 and 4.

[0074] Table 3

[0075]

[0076] Table 4

[0077]

[0078]

[0079] As shown in Table 3, the gloss of the high-performance environmentally friendly water-based coating of the present invention is greater than 92%, indicating that the coating has a good decorative effect. Furthermore, the coating has a hardness grade of 2H or higher, an adhesion grade of 0, a scratch resistance of 8.42-9.81 GPa, and an abrasion resistance of more than 1200 cycles, indicating that the high-performance environmentally friendly water-based coating of the present invention has excellent hardness, adhesion, scratch resistance, abrasion resistance, and weather resistance.

[0080] Comparing Comparative Examples 1-6 with Example 2, it can be seen that in Comparative Examples 3-4, where bentonite or alumina was used alone as the powder, the hardness, scratch resistance, and abrasion resistance of the coatings were all inferior to those of Example 2. However, Example 2, using a combination of bentonite and alumina, not only enhanced the hardness, abrasion resistance, and scratch resistance of the coatings but also improved their adhesion and weather resistance. In Comparative Examples 5-6, where bentonite or alumina was combined with silica, the weather resistance, scratch resistance, and abrasion resistance of the coatings were all lower than those of Example 2, indicating that the effects of this invention cannot be achieved by using any powder combination. In Comparative Examples 1-2, where the particle size of the bentonite or alumina was outside the range defined by this invention, the adhesion, scratch resistance, and abrasion resistance of the coatings were all lower than those of Example 2, indicating that only by using bentonite and alumina with specific particle sizes in this invention can the coating simultaneously possess excellent weather resistance, scratch resistance, decorative properties, and abrasion resistance.

[0081] A comparison of Examples 6-9 with Example 2 reveals that the crosslinking agent in Example 2 was hexamethoxyhydroxymethyl melamine, while in Example 6, the crosslinking agent was a mixture of hexamethoxyhydroxymethyl melamine and butylated melamine. The hardness, scratch resistance, and abrasion resistance of the coatings in Example 6 were all greater than those in Example 2. This indicates that using a mixture of hexamethoxyhydroxymethyl melamine and butylated melamine improves the weather resistance, scratch resistance, and abrasion resistance of the coatings. In Examples 6-9, as the mass ratio of hexamethoxyhydroxymethyl melamine to butylated melamine gradually increased, the gloss and scratch resistance of the coatings first increased and then decreased. This demonstrates that by controlling the mass ratio of hexamethoxyhydroxymethyl melamine to butylated melamine to 1:(2-5), the present invention can achieve optimal coating performance.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A high-performance, environmentally friendly water-based coating, characterized in that, The components include the following parts by weight: Waterborne resin 59-74 parts; powder 10-20 parts; crosslinking agent 0.1-0.5 parts; functional additives 0.5-0.9 parts; solvent 15-20 parts; The powder comprises bentonite and alumina, wherein the D50 particle size of the bentonite is 25-30 nm and the D50 particle size of the alumina is 10-15 nm.

2. The high-performance environmentally friendly water-based coating as described in claim 1, characterized in that, The crosslinking agent includes hexamethoxyhydroxymethyl melamine and butylated melamine.

3. The high-performance environmentally friendly water-based coating as described in claim 2, characterized in that, The mass ratio of hexamethoxyhydroxymethyl melamine to butylated melamine is 1:(2-5).

4. The high-performance environmentally friendly water-based coating as described in claim 1, characterized in that, The waterborne resin includes waterborne acrylic resin or polyurethane resin.

5. The high-performance environmentally friendly water-based coating as described in claim 1, characterized in that, The solvent is water.

6. The high-performance environmentally friendly water-based coating as described in claim 1, characterized in that, The functional additives include at least one of thickeners, dispersants, defoamers, and film-forming aids.

7. The high-performance environmentally friendly water-based coating as described in claim 6, characterized in that, The thickener includes cellulose-based thickeners or polyacrylic acid thickeners; the defoamer includes polydimethylsiloxane.

8. The high-performance environmentally friendly water-based coating as described in claim 6, characterized in that, The film-forming aid includes at least one of Texanol ester, Coasol, and Nexcoat 795.

9. The method for preparing the high-performance environmentally friendly water-based coating as described in any one of claims 1-8, characterized in that, Includes the following steps: (1) Mix the powder with water-based resin, half of the solvent and functional additives evenly to obtain a pre-dispersion; (2) Mix the pre-dispersed liquid with the other half of the solvent and crosslinking agent evenly to obtain a high-performance environmentally friendly water-based coating.

10. The application of the high-performance environmentally friendly waterborne coating as described in any one of claims 1-8 in automobiles.

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