阅读说明：本技术 烤漆用环氧大豆油改性聚酯树脂、制备方法及烤漆制备 (Epoxy soybean oil modified polyester resin for baking varnish, preparation method and baking varnish preparation ) 是由 荆凡 陈安强 刘洋 徐涛 陈昱声 王娅丽 于 2021-08-10 设计创作，主要内容包括：本发明公开了一种烤漆用环氧大豆油改性聚酯树脂、制备方法及烤漆制备,将10-25份二元醇、10-20份多元醇和30-45份二元酸在搅拌下两次升温,控制冷凝温度,待酸值反应至设定值降温,加入2-4份顺丁烯二酸酐、2-5份二甲苯、5-10份环氧大豆油和0.1-1份引发剂后,升温至回流反应至终点；冷却,加入15-25份助溶剂和3-5份中和剂中和后,加入40-50份水乳化,即得到环氧大豆油改性聚酯树脂。利用本发明环氧大豆油改性聚酯树脂制备得到水性透明烤漆喷涂到金属门上,可有效改善底层油墨烤漆面渗色问题,同时烤漆面的光泽和机械性能也得到提高。(The invention discloses epoxy soybean oil modified polyester resin for baking varnish, a preparation method and baking varnish preparation, wherein 10-25 parts of dihydric alcohol, 10-20 parts of polyhydric alcohol and 30-45 parts of dibasic acid are heated twice under stirring, the condensation temperature is controlled, after the acid value reaction reaches a set value and is cooled, 2-4 parts of maleic anhydride, 2-5 parts of dimethylbenzene, 5-10 parts of epoxy soybean oil and 0.1-1 part of initiator are added, the temperature is heated until the reflux reaction reaches the end point; cooling, adding 15-25 parts of cosolvent and 3-5 parts of neutralizer for neutralization, and adding 40-50 parts of water for emulsification to obtain the epoxy soybean oil modified polyester resin. The waterborne transparent baking varnish prepared by the epoxy soybean oil modified polyester resin is sprayed on a metal door, so that the problem of color bleeding of the surface of the bottom ink baking varnish can be effectively solved, and meanwhile, the gloss and the mechanical property of the surface of the baking varnish are improved.)

1. A preparation method of epoxy soybean oil modified polyester resin for baking varnish is characterized by comprising the following steps:

heating 10-25 parts of dihydric alcohol, 10-20 parts of polyhydric alcohol and 30-45 parts of dibasic acid twice under stirring, controlling the condensation temperature, cooling after the acid value is reacted to a set value, adding 2-4 parts of maleic anhydride, 2-5 parts of dimethylbenzene, 5-10 parts of epoxidized soybean oil and 0.1-1 part of initiator, and heating until the reflux reaction is finished; cooling, adding 15-25 parts of cosolvent and 3-5 parts of neutralizer for neutralization, and adding 40-50 parts of water for emulsification to obtain the epoxy soybean oil modified polyester resin.

2. The preparation method of the epoxy soybean oil modified polyester resin for baking varnish as claimed in claim 1, wherein the temperature is raised to 160 ℃, then raised to 200 ℃ by 3-4h, the condensation temperature is controlled not to exceed 105 ℃, and the temperature is reduced to below 100 ℃ after the acid value is reacted to 35-40 mgKOH/g; heating to reflux and reacting at 200-205 ℃ to the end point; cooled to 90 ℃ and added with co-solvent and neutralizing agent.

3. The method for preparing epoxy soybean oil modified polyester resin for baking varnish as claimed in claim 1, wherein the diol is one or more of ethylene glycol, neopentyl glycol, hexanediol, dimethylolpropionic acid, 1, 4-cyclohexanedimethanol and neopentyl glycol hydroxypivalate;

the polyalcohol is one or more of trimethylolpropane, trimethylolethane and pentaerythritol.

4. The method for preparing epoxy soybean oil modified polyester resin for baking varnish as claimed in claim 1, wherein the dibasic acid is one or more of adipic acid, isophthalic acid, terephthalic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride and 1, 4-cyclohexanedicarboxylic acid.

5. The method for preparing epoxidized soybean oil modified polyester resin for baking varnish according to claim 1, wherein the epoxidized soybean oil has an epoxy value of more than 6.3%.

6. The method for preparing epoxy soybean oil modified polyester resin for baking varnish as claimed in claim 1, wherein the initiator is one or more of zinc oxide, zinc naphthenate and zinc acetate.

7. The method for preparing the epoxy soybean oil modified polyester resin for the baking varnish as claimed in claim 1, wherein the cosolvent is one or more of ethylene glycol monobutyl ether, ethylene glycol tertiary butyl ether, propylene glycol methyl ether, n-butyl alcohol and isopropanol.

8. The method for preparing epoxy soybean oil modified polyester resin for baking varnish as claimed in claim 1, wherein the neutralizing agent is AMP-95 or N, N-dimethylethanolamine.

9. An epoxy soybean oil modified polyester resin for baking varnish prepared by the method of claims 1 to 8.

10. The method for preparing the baking varnish by using the epoxidized soybean oil modified polyester resin for the baking varnish as claimed in claim 9, wherein 50-60 parts of the epoxidized soybean oil modified polyester resin, 0.1-1 part of a neutralizing agent, 8-12 parts of a water-based amino resin and 3-5 parts of a cosolvent are uniformly mixed according to the mass ratio, then 0.1-1 part of a defoaming agent TEGO 901W, 0.1-1 part of a leveling agent BYK 333 and 0.1-2 parts of a wetting agent TEGO 270 are sequentially added, and after uniform stirring, 20-40 parts of deionized water is continuously added and uniformly stirred to obtain the water-based transparent baking varnish;

the waterborne amino resin is a Zhanxin CYMEL 325 methyl etherified high imino melamine resin.

Technical Field

The invention belongs to the technical field of coatings, and particularly relates to an epoxidized soybean oil modified polyester resin for water-based transparent baking varnish, a preparation method thereof and baking varnish preparation.

Background

At present, a family decorative door mainly comprises a wooden door and a metal door, wherein the metal door mostly adopts two decorative processes, the first decorative process is made of metal silver flashing baking paint or color baking paint, and the generated effect is single; and secondly, printing by adopting ink transfer printing, printing colorful ink printing patterns on the surface of the metal door in a transfer printing mode, and then spraying water-based transparent baking varnish for protection. However, in the prior art, after the metal door is coated with the water-based transparent baking varnish, the metal door is baked at a high temperature, and the bottom ink can seep out of the baking varnish layer, so that the plastic film coated on the metal door has obvious ink marks, and the use experience of a user is influenced.

At present, water-based alkyd resin, water-based polyester resin, water-based acrylic resin or water-based acrylic modified polyester resin is generally selected as the main film-forming resin of the water-based transparent baking paint in the market, but most of the resins have long-chain molecular structures, and the compactness of a paint film formed after high-temperature baking is insufficient. The epoxidized soybean oil is a renewable raw material with rich resources, low price, no toxicity, environmental friendliness, good thermal stability and good solvent resistance, the molecule of the epoxidized soybean oil contains 3-4 epoxy groups, the epoxidized soybean oil is used for modifying the waterborne polyester resin, the crosslinking degree of the polyester resin can be improved, the prepared waterborne transparent baking varnish is sprayed on a metal door, the ink printed patterns printed on the door can be protected in a sealing way, the problem that the bottom layer ink permeates from the surface of the baking varnish after being baked at high temperature can be effectively solved, the ink marks of a plastic film coated on the metal door can be avoided, and meanwhile, the gloss and the mechanical property of the surface of the baking varnish can be improved.

Disclosure of Invention

In order to solve the defects in the prior art, the invention aims to provide the epoxidized soybean oil modified polyester resin for the water-based transparent baking varnish, the preparation method and the baking varnish preparation method thereof, and the epoxidized soybean oil modified polyester resin can be used for improving the industrial problem that the surface of the water-based transparent baking varnish is subjected to color bleeding after the ink printing on the metal door is baked at high temperature.

The invention is realized by the following technical scheme.

The invention provides a preparation method of epoxy soybean oil modified polyester resin for baking varnish, which comprises the following steps:

heating 10-25 parts of dihydric alcohol, 10-20 parts of polyhydric alcohol and 30-45 parts of dibasic acid twice under stirring, controlling the condensation temperature, cooling after the acid value is reacted to a set value, adding 2-4 parts of maleic anhydride, 2-5 parts of dimethylbenzene, 5-10 parts of epoxidized soybean oil and 0.1-1 part of initiator, and heating until the reflux reaction is finished; cooling, adding 15-25 parts of cosolvent and 3-5 parts of neutralizer for neutralization, and adding 40-50 parts of water for emulsification to obtain the epoxy soybean oil modified polyester resin.

Preferably, the temperature is firstly raised to 160 ℃, then raised to 200 ℃ in 3-4h, the condensation temperature is controlled not to exceed 105 ℃, and the temperature is reduced to below 100 ℃ after the acid value is reacted to 35-40 mgKOH/g; heating to reflux and reacting at 200-205 ℃ to the end point; cooled to 90 ℃ and added with co-solvent and neutralizing agent.

Preferably, the dihydric alcohol is one or more of ethylene glycol, neopentyl glycol, hexanediol, dimethylolpropionic acid, 1, 4-cyclohexanedimethanol and neopentyl glycol hydroxypivalate.

Preferably, the polyhydric alcohol is one or more of trimethylolpropane, trimethylolethane and pentaerythritol.

Preferably, the dibasic acid is one or more of adipic acid, isophthalic acid, terephthalic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride and 1, 4-cyclohexanedicarboxylic acid.

Preferably, the epoxidized soybean oil has an epoxy value greater than 6.3%.

Preferably, the initiator is one or more of zinc oxide, zinc naphthenate and zinc acetate.

Preferably, the cosolvent is one or more of ethylene glycol monobutyl ether, ethylene glycol tertiary butyl ether, propylene glycol methyl ether, n-butyl alcohol and isopropanol.

Preferably, the neutralizing agent is AMP-95 or N, N-dimethylethanolamine.

In another aspect of the invention, the epoxy soybean oil modified polyester resin for baking varnish prepared by the method is provided.

According to the other aspect of the invention, 50-60 parts of epoxidized soybean oil modified polyester resin, 0.1-1 part of neutralizing agent, 8-12 parts of water-based amino resin and 3-5 parts of cosolvent are uniformly mixed according to the mass ratio, then 0.1-1 part of defoaming agent TEGO 901W, 0.1-1 part of flatting agent BYK 333 and 0.1-2 parts of wetting agent TEGO 270 are sequentially added, and after uniform stirring, 20-40 parts of deionized water is continuously added and uniformly stirred to obtain the water-based transparent baking paint;

the waterborne amino resin is a Zhanxin CYMEL 325 methyl etherified high imino melamine resin.

Due to the adoption of the technical scheme, the device has the following beneficial effects:

the epoxy soybean oil modified polyester resin for preparing the waterborne transparent baking varnish has the advantages that the crosslinking degree of the polyester resin is improved through the ring-opening reaction of the epoxy groups in the epoxy soybean oil molecules and the carboxyl groups in the polyester resin molecules, the modified polyester resin has excellent flexibility and gloss retention, meanwhile, the introduction of the epoxy soybean oil enables the paint film to have excellent solvent resistance and thermal stability, and the hardness and the water resistance of the paint film are greatly improved due to the improvement of the crosslinking degree of the modified resin. The modified resin prepared by the invention has simple process and lower cost, and can effectively improve the industry difficult problem that the ink printing on the metal door is bleedown from the surface of the water-based transparent baking varnish after being baked at high temperature.

The invention is characterized in that:

1) the epoxidized soybean oil is a renewable raw material with rich resources, low price, no toxicity, environmental friendliness, good thermal stability and good solvent resistance, the epoxidized soybean oil is used as a modifier of the polyester resin, the advantages of good thermal stability and good solvent resistance of the epoxidized soybean oil can be fully exerted, and the raw material is easy to obtain, low in cost and high in environmental protection property.

2) The invention adopts a production process combining a melting method and a solvent method, the polyester resin component is conventional polyester resin, firstly, the melting method is adopted, when the resin reacts to a certain acid value, epoxidized soybean oil and a reflux solvent are added, and the solvent method is adopted to react until the acid value is qualified. The production process does not need to change the existing production device, and is simple and controllable.

3) The pH value of the epoxidized soybean oil modified polyester resin prepared by the invention is 7.5-9.0, and the epoxidized soybean oil has good protection effect on ester bonds in polyester components under alkaline conditions, so that hydrolysis of the ester bonds can be reduced, and the storage stability of the water-based transparent baking varnish is greatly improved.

Detailed Description

The present invention will be described in detail with reference to specific embodiments, which are illustrative of the invention and are not to be construed as limiting the invention.

In one embodiment of the present invention, a method for preparing an epoxy soybean oil modified polyester resin for water-based transparent baking varnish is provided, which comprises:

stirring and heating 10-25 parts of dihydric alcohol (one or more of ethylene glycol, neopentyl glycol, hexanediol, dimethylolpropionic acid, 1, 4-cyclohexanedimethanol and neopentyl glycol hydroxypivalate), 10-20 parts of polyhydric alcohol (one or more of trimethylolpropane, trimethylolethane and pentaerythritol) and 30-45 parts of dibasic acid (one or more of adipic acid, isophthalic acid, terephthalic acid, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride and 1, 4-cyclohexanedicarboxylic acid) to 160 ℃, then heating to 200 ℃ for 3-4h, and controlling the condensation temperature not to exceed 105 ℃; after the acid value is reacted to 35-40mgKOH/g, the temperature is reduced to be lower than 100 ℃, 2-4 parts of maleic anhydride, 2-5 parts of xylene, 5-10 parts of epoxidized soybean oil with the epoxy value of more than 6.3 percent and 0.1-1 part of initiator (one or more of zinc oxide, zinc naphthenate and zinc acetate) are added, and then the temperature is raised to reflux and the reaction is carried out at the temperature of 200-; cooling to 90 ℃, adding 15-25 parts of cosolvent (one or more of ethylene glycol monobutyl ether, ethylene glycol tertiary butyl ether, propylene glycol methyl ether, N-butyl alcohol and isopropanol) and 3-5 parts of neutralizer (AMP-95 or N, N-dimethylethanolamine) for neutralization, adding 40-50 parts of water for emulsification to obtain the epoxy soybean oil modified polyester resin, filtering, cooling and packaging.

The preparation of epoxidized soybean oil modified polyester resin of the present invention is further illustrated by the following specific examples.

Example 1

Adding 10g of neopentyl glycol, 19g of trimethylolpropane, 10g of trimethylolethane, 12.8g of phthalic anhydride, 18.4g of hexahydrophthalic anhydride and 7g of adipic acid into a container with a stirrer and a thermometer, heating to 160 ℃ while stirring, heating to 200 ℃ for 3h, reacting to an acid value of 35mgKOH/g, cooling to below 100 ℃, adding 2g of maleic anhydride, 3g of xylene, 6g of epoxidized soybean oil and 0.1g of zinc oxide, heating to reflux, and reacting to an end point at 205 ℃; cooling to 90 ℃, adding 15g of ethylene glycol tert-butyl ether and 5g of N-butanol, stirring uniformly, adding 4g of N, N-dimethylethanolamine for neutralization, adding 45g of water for emulsification, and obtaining the epoxy soybean oil modified polyester resin.

Example 2

Adding 9.6g of ethylene glycol, 2g of 1, 4-cyclohexanedimethanol, 4g of dimethylolpropionic acid, 19.8g of pentaerythritol, 9g of phthalic anhydride, 21.6g of tetrahydrophthalic anhydride and 11g of adipic acid into a container with a stirrer and a thermometer, heating to 160 ℃ while stirring, heating to 200 ℃ for 4 hours until the acid value is 38mgKOH/g, cooling to below 100 ℃, adding 2g of maleic anhydride, 5g of xylene, 8g of epoxidized soybean oil and 0.2g of zinc naphthenate, heating to reflux, and reacting to the end point at 200 ℃; cooling to 90 ℃, adding 20g of ethylene glycol monobutyl ether and 5g of isopropanol, stirring uniformly, adding 5g of AMP-95 for neutralization, and adding 45g of water for emulsification to obtain the epoxy soybean oil modified polyester resin.

Example 3

Adding 17.4g of neopentyl glycol, 4g of dimethylolpropionic acid, 10.8g of pentaerythritol, 11g of isophthalic acid, 19.6g of hexahydrophthalic anhydride and 10.4g of adipic acid into a container with a stirrer and a thermometer, heating to 160 ℃ while stirring, heating to 200 ℃ within 3.5h, cooling to below 100 ℃ after the acid value reacts to 40mgKOH/g, adding 3g of maleic anhydride, 4g of xylene, 7g of epoxidized soybean oil and 0.5g of zinc acetate, heating to reflux, and reacting to the end point at 200 ℃; cooling to 90 ℃, adding 15g of propylene glycol methyl ether and 4g of N-butanol, stirring uniformly, adding 3g of N, N-dimethylethanolamine for neutralization, and adding 50g of water for emulsification to obtain the epoxy soybean oil modified polyester resin.

Example 4

Adding 8.6g of ethylene glycol, 6g of dimethylolpropionic acid, 13.8g of trimethylolpropane, 9.8g of phthalic anhydride, 19.6g of hexahydrophthalic anhydride and 9g of adipic acid into a container with a stirrer and a thermometer, heating to 160 ℃ while stirring, heating to 200 ℃ for 4 hours until the acid value reacts to 35-40mgKOH/g, cooling to below 100 ℃, adding 2g of maleic anhydride, 3g of xylene, 5g of epoxidized soybean oil and 0.8g of zinc acetate, heating to reflux, and reacting to the end point at 205 ℃; cooling to 90 ℃, adding 18g of ethylene glycol monobutyl ether and 5g of isopropanol, stirring uniformly, adding 4g of N, N-dimethylethanolamine for neutralization, and adding 48g of water for emulsification to obtain the epoxy soybean oil modified polyester resin.

Example 5

Adding 17.8g of hexanediol, 7.2g of neopentyl glycol hydroxypivalate, 19.6g of pentaerythritol, 11g of terephthalic acid, 10.6g of tetrahydrophthalic anhydride and 9g of 1, 4-cyclohexanedicarboxylic acid into a container with a stirrer and a thermometer, heating to 160 ℃ while stirring, heating to 200 ℃ for 4 hours, cooling to below 100 ℃ after the acid value is reacted to 36mgKOH/g, adding 4g of maleic anhydride, 3g of xylene, 10g of epoxidized soybean oil and 1.0g of zinc oxide, heating to reflux, and reacting to the end point at 200 ℃; cooling to 90 ℃, adding 22g of ethylene glycol tert-butyl ether and 5g of n-butyl alcohol, stirring uniformly, adding 4g of AMP-95 for neutralization, and adding 50g of water for emulsification to obtain the epoxy soybean oil modified polyester resin.

The epoxidized soybean oil modified polyester resin prepared by the invention meets the following technical indexes:

solid content: 45.0% -55.0%; viscosity: 500-; pH value: 7.0-9.0; storage stability: the phenomena of cloudiness, water diversion and precipitation do not occur in 6 months.

In still another embodiment of the present invention, there is provided a method for preparing an aqueous transparent baking varnish using a modified polyester resin, comprising the steps of:

uniformly mixing 50-60 parts of epoxidized soybean oil modified polyester resin, 0.1-1 part of neutralizing agent (AMP-95 or N, N-dimethylethanolamine), 8-12 parts of waterborne amino resin (Zhanxin CYMEL 325 methyl etherified high imino melamine resin), 3-5 parts of cosolvent (one or more of ethylene glycol monobutyl ether, ethylene glycol tert-butyl ether, propylene glycol methyl ether, N-butyl alcohol and isopropanol), sequentially adding 0.1-1 part of defoamer TEGO 901W, 0.1-1 part of flatting agent BYK 333 and 0.1-2 parts of wetting agent TEGO 270, uniformly stirring, continuously adding 20-40 parts of deionized water, and uniformly stirring to obtain the water-based transparent baking paint.

The epoxidized soybean oil modified polyester resins produced according to examples 1 to 5 of the present invention were used as experimental groups, and a commercially available aqueous acrylic acid modified polyester resin was used as a control group, and the preparation of the epoxidized soybean oil modified polyester resin of the present invention is further described below by way of specific examples.

Example 6

Uniformly mixing 50 parts of epoxy soybean oil modified polyester resin, 0.7 part of neutralizing agent AMP-95, 8 parts of waterborne amino resin (Zhanxin CYMEL 325 methyl etherified high imino melamine resin), 4 parts of cosolvent n-butyl alcohol and isopropanol according to the mass ratio, then sequentially adding 0.5 part of defoaming agent TEGO 901W, 1 part of flatting agent BYK 333 and 1 part of wetting agent TEGO 270, uniformly stirring, and then continuously adding 40 parts of deionized water and uniformly stirring to obtain the waterborne transparent baking paint.

Example 7

Uniformly mixing 60 parts of epoxidized soybean oil modified polyester resin, 0.1 part of neutralizer N, N-dimethylethanolamine, 12 parts of waterborne amino resin (Zhanxin CYMEL 325 methyl etherified high imino melamine resin) and 5 parts of cosolvent propylene glycol methyl ether according to a mass ratio, then sequentially adding 0.1 part of defoamer TEGO 901W, 0.1 part of flatting agent BYK 333 and 2 parts of wetting agent TEGO 270, uniformly stirring, and continuously adding 20 parts of deionized water and uniformly stirring to obtain the waterborne transparent baking paint.

Example 8

Uniformly mixing 55 parts of epoxidized soybean oil modified polyester resin, 1 part of neutralizing agent AMP-95, 10 parts of waterborne amino resin (Zhanxin CYMEL 325 methyl etherified high imino melamine resin), 4 parts of cosolvent ethylene glycol monobutyl ether and ethylene glycol tertiary butyl ether according to the mass ratio, then sequentially adding 1 part of defoamer TEGO 901W, 0.8 part of flatting agent BYK 333 and 1.2 parts of wetting agent TEGO 270, uniformly stirring, and then continuously adding 30 parts of deionized water and uniformly stirring to obtain the waterborne transparent baking paint.

Example 9

Uniformly mixing 60 parts of epoxidized soybean oil modified polyester resin, 0.5 part of neutralizing agent AMP-95, 12 parts of waterborne amino resin (Zhanxin CYMEL 325 methyl etherified high imino melamine resin) and 5 parts of cosolvent ethylene glycol monobutyl ether according to the mass ratio, then sequentially adding 1 part of defoamer TEGO 901W, 0.5 part of flatting agent BYK 333 and 1 part of wetting agent TEGO 270, uniformly stirring, and then continuously adding 30 parts of deionized water and uniformly stirring to obtain the waterborne transparent baking paint.

Example 10

Uniformly mixing 50 parts of epoxidized soybean oil modified polyester resin, 1 part of neutralizing agent AMP-95, 8 parts of water-based amino resin (Zhanxin CYMEL 325 methyl etherified high imino melamine resin) and 3 parts of cosolvent ethylene glycol tertiary butyl ether according to the mass ratio, then sequentially adding 1 part of defoaming agent TEGO 901W, 0.5 part of flatting agent BYK 333 and 1 part of wetting agent TEGO 270, uniformly stirring, and then continuously adding 30 parts of deionized water and uniformly stirring to obtain the water-based transparent baking paint.

Comparative example 1

Uniformly mixing 55 parts of waterborne acrylic modified polyester resin, 1 part of neutralizing agent AMP-95, 10 parts of waterborne amino resin (Zhanxin CYMEL 325 methyl etherified high imino melamine resin), 5 parts of cosolvent ethylene glycol monobutyl ether and ethylene glycol tertiary butyl ether according to the mass ratio, then sequentially adding 1 part of defoamer TEGO 901W, 0.8 part of flatting agent BYK 333 and 1.2 parts of wetting agent TEGO 270, uniformly stirring, and then continuously adding 30 parts of deionized water and uniformly stirring to obtain the waterborne transparent baking paint.

The aqueous transparent baking paints prepared according to examples 6 to 10 were respectively subjected to performance tests on the hardness, impact resistance, flexibility, adhesion, intercoat adhesion, bleeding resistance and xenon lamp-resistant artificial aging of the paint films, and the test results are shown in table 1.

TABLE 1 test results of the preparation of aqueous clear baking varnish for the experimental and control groups

According to the detection results, the water-based transparent baking varnish prepared by the embodiment of the invention has the pencil hardness of more than or equal to 3H, the impact resistance of more than or equal to 50cm, the flexibility of less than or equal to 1mm, the adhesive force of the single coating and the multiple coating is less than or equal to 1 grade, the paint film does not seep after being baked for 12 hours at 50 ℃, the xenon lamp artificial aging resistance is 800 hours, the paint film does not bubble, fall off or crack, the color change grade is less than or equal to 1 grade, the light loss grade is less than or equal to 1 grade, and all performance indexes are superior to those of a comparative example. Therefore, the invention has great economic value and environmental protection value, and is more suitable for popularization and application.

Finally, it should be noted that the above-mentioned embodiments are only preferred embodiments of the present invention, and not intended to limit the present invention, and although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications and equivalents can be made in the technical solutions described in the above-mentioned embodiments, or some technical features can be replaced. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.