Fingerprint-resistant paint vehicle for color plate and color plate production process

Abstract

The invention discloses a fingerprint-resistant paint vehicle for a color plate and a color plate production process, and belongs to the technical field of color plate production, the fingerprint-resistant paint vehicle comprises the following raw materials by weight: 30-40 parts of waterborne polyester resin, 1.2-1.5 parts of diethanol amine, 3-5 parts of polypyrrole modified titanium dioxide, 20 parts of deionized water, 0.2 part of an antifoaming agent, 0.3 part of a wetting leveling agent, 7-14 parts of amino resin, and 0.2 part of a thickening agent; polypyrrole modified titanium dioxide and alkyl long-chain dithiodihydric alcohol are introduced into the paint vehicle, a paint film is endowed with good fingerprint resistance and mechanical properties, the color plate prepared by using the fingerprint-resistant paint vehicle as finish paint is simple in preparation method and has good decoration performance, and the color plate can be widely applied to the field of color plates. The characteristics of fingerprint resistance, self-cleaning and self-repairing further expand the application scene.

Description

Technical Field

[0001] The invention belongs to the technical field of color plate production, and particularly relates to a fingerprint-resistant paint for color plates and a color plate production process. Background Art

[0002] Colored steel plate, also known as color coated steel plate, is a product made of cold rolled steel plate, electrogalvanized steel plate, hot dip galvanized steel plate or aluminum zinc plate as the substrate, after surface degreasing and passivation treatment, coated with organic coating and baked. Colored steel plate has both the strength of steel plate and good corrosion resistance. Organic coating can be formulated into various colors, and can be made into various patterns such as wood grain, cloth grain and leather grain with the help of printing and embossing technology, giving the steel plate a beautiful appearance.

[0003] Based on aesthetic requirements, people have higher and higher requirements for the anti-fouling performance of color plates, especially the anti-fingerprint performance. For example, Chinese patent CN 105462460B discloses an anti-fouling and anti-fingerprint water-based coating for stainless steel plates and a preparation method thereof. The coating is specifically composed of 55-70% by weight of hydroxyl-modified water-based polyester resin, 8-15% by weight of methyl etherified amino resin, 3-5% by weight of modified silica sol, 2-4% by weight of neutralizer, 0.1-0.3% by weight of wetting agent, etc. The prepared coating has anti-fingerprint imprinting performance, but does not have self-repairing performance. It is easy to be rubbed during transportation or installation, resulting in a decrease in the decorative and protective performance of the coating. Summary of the invention

[0004] The object of the present invention is to provide a fingerprint-resistant paint for color plates and a color plate production process, so as to solve the problem that the existing fingerprint-resistant paint for color plate production does not have self-repairing performance.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A fingerprint-resistant paint for color plates, comprising the following raw materials in parts by weight:

[0007] 30-40 parts of water-based polyester resin

[0008] 1.2-1.5 parts of diethanolamine

[0009]

[0010] The preparation process of the above-mentioned fingerprint-resistant paint for color plates is as follows:

[0011] Add water-based polyester resin, polypyrrole-modified titanium dioxide, diethanolamine and deionized water into a stirring tank, add defoamer and wetting and leveling agent while stirring, add amino resin after stirring for 30 minutes, continue stirring for 30 minutes, add thickener, and continue stirring for 10 minutes to obtain fingerprint-resistant paint for color plates.

[0012] Further, the water-based polyester resin is prepared by the following steps:

[0013] Trihydroxypropane, alkyl long-chain disulfide glycol, phthalic anhydride, isophthalic acid, adipic acid and trimellitic anhydride are added into a reaction kettle, stirred at 120° C. for 10-20 min under nitrogen protection, a catalyst is added, and the reaction is kept at 220-250° C. until the acid value is less than 5 mgKOH / g, the temperature is reduced to 210° C. and vacuum is applied, the temperature is then reduced to 160° C. and trimellitic anhydride is added, the reaction is carried out at 170-175° C. until the acid value is 26-30 mgKOH / g, and then ethylene glycol butyl ether is added to obtain an aqueous polyester resin.

[0014] Furthermore, the mass ratio of trihydroxypropane, alkyl long-chain disulfide glycol, phthalic anhydride, isophthalic acid, adipic acid, trimellitic anhydride, catalyst and ethylene glycol butyl ether is 8-10:23-30:3-5:10-18:6-13:7-10:0.08-0.15:25-30, and the mass ratio of trimellitic anhydride added successively is 1:2.

[0015] Furthermore, the catalyst is Tyzor 428 titanate chelate.

[0016] Furthermore, the alkyl long-chain dithiodiol is obtained by a ring-opening reaction of 3,3'-dithiobispropylamine and a long-chain alkyl glycidyl ether.

[0017] Furthermore, the long-chain alkyl glycidyl ether is at least one of dodecyl glycidyl ether, glycidyl hexadecyl ether and octadecyl glycidyl ether.

[0018] Further, the preparation process of alkyl long-chain disulfide diol is as follows:

[0019] Add 3,3'-dithiobispropylamine and long-chain alkyl glycidyl ether into tetrahydrofuran, stir and react at 40°C for 30-60 minutes, then remove the tetrahydrofuran by rotary evaporation. The molar ratio of 3,3'-dithiobispropylamine and long-chain alkyl glycidyl ether is 1:2. Through the ring-opening reaction between the amino group and the epoxy group, a diol containing a disulfide bond and a long alkyl chain is obtained.

[0020] Further, the preparation process of polypyrrole-modified titanium dioxide is as follows:

[0021] Mix nano titanium dioxide, sodium dodecylbenzene sulfonate, deionized water and pyrrole evenly, then add ferric chloride solution dropwise, stir and react at room temperature for 12 hours, and after the reaction is completed, filter and wash the filter cake with deionized water and dry;

[0022] The dosage ratio of nano titanium dioxide, sodium dodecylbenzene sulfonate, deionized water, pyrrole and ferric chloride is 10g: 1.2-1.8g: 100mL: 0.6-0.9g: 14.1g: 1000mL, the mass fraction of ferric chloride in the ferric chloride solution is 10-15%, nano titanium dioxide is a commonly used inorganic filler in paints, but it is easy to agglomerate, the present invention introduces a polypyrrole coating layer on the surface of nano titanium dioxide by chemical means, on the one hand, improves its dispersibility in the paint, on the other hand, with the help of poly The conductive property of pyrrole can reduce the recombination probability of photogenerated electrons and holes and improve the photocatalytic activity of nano-titanium dioxide. However, the ratio between nano-titanium dioxide and pyrrole should be strictly controlled. When the amount of pyrrole is small, the amount of polypyrrole coated with nano-titanium dioxide is small, and the amount of electrons injected into nano-titanium dioxide by polypyrrole per unit time is small, which does not significantly improve the photocatalytic activity of nano-titanium dioxide. When the amount of pyrrole is too large, the surface of nano-titanium dioxide is over-coated, which blocks its absorption of light and also leads to reduced photocatalytic activity.

[0023] Furthermore, the defoaming agent is one or a mixture of BYK-028, BYK-022, BYK-024 and BYK-094.

[0024] Furthermore, the wetting and leveling agent is one or a mixture of TEGO-270, TEGO-410, TEGO-450 and TEGO-482.

[0025] Furthermore, the amino resin is CYMEL 325 amino resin.

[0026] Furthermore, the thickener is polyurethane thickener RM-8W and / or polyurethane thickener RM-2020.

[0027] A color plate production process comprises the following steps:

[0028] S1, placing the metal substrate in a degreasing solution for degreasing treatment, and then washing with water and drying to obtain a pre-treated plate;

[0029] S2, immersing the pre-treated plate in a passivation solution, performing passivation treatment, and obtaining a passivated plate;

[0030] S3. The anti-fingerprint paint for color plates is coated on the surface of the passivation plate to a thickness of 20-25 μm, and then baked at 140-160° C. for 30 min to obtain a color plate.

[0031] Furthermore, the metal substrate is one of a cold-rolled steel sheet, an electro-galvanized steel sheet, a hot-dip galvanized steel sheet and an galvanized steel sheet.

[0032] Beneficial effects of the present invention:

[0033] 1. The present invention provides a fingerprint-resistant paint for color plates, which uses water-based polyester resin and amino resin as main film-forming substances. The water-based polyester resin is obtained by esterification reaction of dibasic acid and its derivatives with polyols. The molecule is a linear structure and plays a plasticizing role in the paint film. The methoxy group and amine group in the amino resin are cross-linked and cured with the hydroxyl group in the water-based polyester resin to form a strong three-dimensional structure, which has excellent light and color retention performance. In addition, in the production process of the water-based polyester resin, the present invention uses alkyl long-chain disulfide diols to replace the existing diols (neopentyl glycol and / or diethylene glycol), which can not only participate in the esterification reaction, but also carry hydrophobic alkyl long chains and disulfide bonds. The hydrophobic alkyl long chains give the paint film a lower surface tension, making it difficult for liquids such as water and oil to stay on its surface, reducing the attachment of fingerprints and other stains. The disulfide bonds give the paint film good self-repairing properties, so that when the paint film is destroyed or damaged, it can automatically restore or partially restore its original structure and function through the internal self-repairing mechanism, thereby improving the durability and service life of the paint film.

[0034] 2. The present invention introduces polypyrrole-modified titanium dioxide as filler particles in the fingerprint-resistant paint, which has good dispersibility in the paint, is beneficial to the transmission of stress loads, absorbs impact energy, and improves the impact resistance of the paint film; and compared with titanium dioxide, the polypyrrole-modified titanium dioxide has a larger specific surface area, enhanced light absorption in the visible light region, and significantly improved photocatalytic activity, giving the paint film good self-cleaning properties. In addition, based on the good light-to-heat conversion effect and thermal conductivity of polypyrrole, it also helps to improve the self-repair efficiency of the paint film.

[0035] 3. The present invention strictly limits the content of polypyrrole-modified titanium dioxide in the paint film. The introduction of polypyrrole-modified titanium dioxide with a lower content is difficult to play a good gain effect. The introduction of polypyrrole-modified titanium dioxide with a higher content has a poor dispersion effect, resulting in partial agglomeration between particles, making the coating homogeneous and causing poor mechanical properties.

[0036] 4. The present invention also provides a color plate prepared using the above-mentioned fingerprint-resistant paint as a topcoat. The preparation method is simple and has good decorative properties. The characteristics of fingerprint resistance, self-cleaning and self-repairing further expand its application scenarios. DETAILED DESCRIPTION

[0037] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Preparation Example 1

[0039] Polypyrrole modified titanium dioxide is prepared as follows:

[0040] Mix 10g of nano titanium dioxide, 1.2g of sodium dodecylbenzene sulfonate, 100mL of deionized water and 0.6g of pyrrole evenly, then add 1000mL of ferric chloride solution, the mass fraction of ferric chloride in the ferric chloride solution is 10%. After the addition is completed, stir the reaction at room temperature for 12h. After the reaction is completed, filter, wash the filter cake with deionized water and dry it.

[0041] Preparation Example 2

[0042] Polypyrrole modified titanium dioxide is prepared as follows:

[0043] Mix 10g of nano titanium dioxide, 1.8g of sodium dodecylbenzene sulfonate, 100mL of deionized water and 0.9g of pyrrole evenly, then add 1000mL of ferric chloride solution, the mass fraction of ferric chloride in the ferric chloride solution is 15%. After the addition is completed, stir the reaction at room temperature for 12h. After the reaction is completed, filter, wash the filter cake with deionized water and dry it.

[0044] Comparative Example 1

[0045] The preparation of polypyrrole-modified titanium dioxide is different from that of Preparation Example 1, except that the amount of pyrrole in Preparation Example 1 is adjusted from "0.6 g" to "0.5 g".

[0046] Comparative Example 2

[0047] The preparation of polypyrrole-modified titanium dioxide is different from that of Preparation Example 2, except that the amount of pyrrole in Preparation Example 2 is adjusted from "0.9 g" to "1.0 g".

[0048] Example 1

[0049] A fingerprint-resistant paint for color plates, comprising the following raw materials in parts by weight:

[0050]

[0051] The preparation process of the above-mentioned fingerprint-resistant paint for color plates is as follows:

[0052] Add water-based polyester resin, polypyrrole-modified titanium dioxide, diethanolamine and deionized water into a stirring tank, add defoamer and wetting and leveling agent while stirring at a speed of 1000 r / min, add amino resin after stirring for 30 minutes, continue stirring for 30 minutes, add thickener, and continue stirring for 10 minutes to obtain fingerprint-resistant paint for color plates.

[0053] Waterborne polyester resin is made by the following steps:

[0054] 8 g of trihydroxypropane, 23 g of alkyl long-chain disulfide glycol, 3 g of phthalic anhydride, 10 g of isophthalic acid, 6 g of adipic acid and 2.3 g of trimellitic anhydride were added into a reactor, stirred at 120° C. for 10 min under nitrogen protection, 0.08 g of Tyzor 428 titanate chelate was added, and the reaction was kept at 220° C. until the acid value was less than 5 mgKOH / g. The temperature was lowered to 210° C. and vacuum was applied. The temperature was then lowered to 160° C. and 4.7 g of trimellitic anhydride was added. The reaction was continued at 170° C. until the acid value was 26 mgKOH / g. Then 25 g of ethylene glycol butyl ether was added to obtain an aqueous polyester resin.

[0055] The preparation process of alkyl long-chain disulfide diols is as follows:

[0056] Add 0.1 mol 3,3'-dithiobispropylamine and 0.2 mol dodecyl glycidyl ether into 500 mL tetrahydrofuran, stir and react at 40°C for 30 min, and then remove the tetrahydrofuran by rotary evaporation.

[0057] The defoamer is BYK-028, the wetting and leveling agent is TEGO-270, the amino resin is CYMEL325 amino resin, and the thickener is polyurethane thickener RM-8W.

[0058] Example 2

[0059] A fingerprint-resistant paint for color plates, comprising the following raw materials in parts by weight:

[0060]

[0061] The preparation of the fingerprint-resistant paint for the color plate is the same as that in Example 1.

[0062] Waterborne polyester resin is made by the following steps:

[0063] 9 g of trihydroxypropane, 25 g of alkyl long-chain disulfide glycol, 4 g of phthalic anhydride, 16 g of isophthalic acid, 10 g of adipic acid and 3 g of trimellitic anhydride were added into a reactor, stirred at 120° C. for 15 min under nitrogen protection, 0.1 g of Tyzor 428 titanate chelate was added, the reaction was kept at 240° C. until the acid value was less than 5 mgKOH / g, the temperature was lowered to 210° C. for evacuation, the temperature was lowered to 160° C., 7 g of trimellitic anhydride was added, the reaction was continued at 173° C. until the acid value was 28 mgKOH / g, and 28 g of ethylene glycol butyl ether was added to obtain an aqueous polyester resin.

[0064] The preparation process of alkyl long-chain disulfide diols is as follows:

[0065] Add 0.1 mol 3,3'-dithiobispropylamine and 0.2 mol glycidyl hexadecyl ether into 500 mL tetrahydrofuran, stir and react at 40°C for 60 min, and then remove the tetrahydrofuran by rotary evaporation.

[0066] The defoamer is BYK-022, the wetting and leveling agent is TEGO-410, the amino resin is CYMEL325 amino resin, and the thickener is polyurethane thickener RM-2020.

[0067] Example 3

[0068] A fingerprint-resistant paint for color plates, comprising the following raw materials in parts by weight:

[0069]

[0070] The preparation of the fingerprint-resistant paint for the color plate is the same as that in Example 1.

[0071] Waterborne polyester resin is made by the following steps:

[0072] 10 g of trihydroxypropane, 30 g of alkyl long-chain disulfide glycol, 5 g of phthalic anhydride, 18 g of isophthalic acid, 13 g of adipic acid and 3.3 g of trimellitic anhydride were added into a reactor, stirred at 120° C. for 20 min under nitrogen protection, 0.15 g of Tyzor 428 titanate chelate was added, and the reaction was carried out at 250° C. until the acid value was less than 5 mgKOH / g. The temperature was reduced to 210° C. for evacuation, and then the temperature was reduced to 160° C., 7.7 g of trimellitic anhydride was added, and the reaction was carried out at 175° C. until the acid value was 30 mgKOH / g. Then 30 g of ethylene glycol butyl ether was added to obtain an aqueous polyester resin.

[0073] The preparation process of alkyl long-chain disulfide diols is as follows:

[0074] Add 0.1 mol 3,3'-dithiobispropylamine and 0.2 mol octadecyl glycidyl ether into 500 mL tetrahydrofuran, stir and react at 40°C for 60 min, and then remove the tetrahydrofuran by rotary evaporation.

[0075] The defoamer is BYK-024, the wetting and leveling agent is TEGO-270, the amino resin is CYMEL325 amino resin, and the thickener is polyurethane thickener RM-8W.

[0076] Comparative Example 1

[0077] A fingerprint-resistant paint for color plates, compared with Example 1, the only difference is that the polypyrrole-modified titanium dioxide in Example 1 is replaced by an equal weight portion of the product prepared in Control Example 1.

[0078] Comparative Example 2

[0079] A fingerprint-resistant paint for color plates, compared with Example 2, the only difference is that the polypyrrole-modified titanium dioxide in Example 1 is replaced by an equal weight portion of the product prepared in Control Example 2.

[0080] Comparative Example 3

[0081] A fingerprint-resistant paint for color plates, compared with Example 1, the only difference is that the amount of polypyrrole-modified titanium dioxide in Example 1 is adjusted from "3 parts by weight" to "2 parts by weight".

[0082] Comparative Example 4

[0083] A fingerprint-resistant paint for color plates, compared with Example 3, the only difference is that the amount of polypyrrole-modified titanium dioxide in Example 3 is adjusted from "5 parts by weight" to "6 parts by weight".

[0084] Comparative Example 5

[0085] A fingerprint-resistant paint for color plates, compared with Example 1, the only difference is that the polypyrrole-modified titanium dioxide in Example 1 is replaced by an equal weight portion of nano-titanium dioxide.

[0086] Comparative Example 6

[0087] A fingerprint-resistant paint for color plates, compared with Example 1, the only difference is that the alkyl long-chain disulfide glycol in Example 1 is replaced by a mixture of neopentyl glycol and diethylene glycol in a mass ratio of 1:5.

[0088] Test Case

[0089] (i) The anti-fingerprint paint prepared in the above Examples 1-3 and Comparative Examples 1-6 was coated on a tinplate test plate, and the paint film was naturally dried at room temperature for 1 hour, then baked and cured at 140° C. for 30 minutes, and cooled to room temperature to obtain a paint film with a thickness of 35 μm;

[0090] The impact resistance of these paint films was tested with reference to standard GB / T 1732-1993;

[0091] The photocatalytic self-cleaning performance was evaluated using 20 mg / L methyl orange solution as the target degradation product; the specific operation is as follows:

[0092] 50 mL of the target degradation product solution was measured in a petri dish, the paint film was immersed in the target solution, and the petri dish was placed in a photocatalytic reaction device. The light source was a 300W xenon lamp, the sample was 20 cm away from the light source, and the absorbance of the target degradation product was measured using a 722 visible spectrophotometer. The maximum absorption wavelength of the methyl orange solution at 465 nm was used as the reference position, and the absorbance of each sample after 10 minutes of xenon lamp irradiation was measured regularly to calculate the residual concentration percentage of the methyl orange solution.

[0093] (II) The fingerprint-resistant paints prepared in the above-mentioned Examples 1-3 and Comparative Examples 1-6 are applied to the production of color plates, and the specific process flow is as follows:

[0094] S1. The hot-dip galvanized steel sheet was placed in a degreasing solution at 50°C for 5 minutes for degreasing treatment. The degreasing solution was composed of FKES-0622 water-based degreasing agent (purchased from Shanghai Yinxi Industrial Co., Ltd.) and water in a mass ratio of 1:10. Then, the steel sheet was rinsed with water and dried to obtain a pre-treated sheet.

[0095] S2, immersing the pre-treated board in a passivation solution, treating at 60°C for 4 seconds, taking it out, and drying it at 170°C for 15 seconds, wherein the passivation solution is composed of a passivation agent and deionized water in a ratio of 1:5, to obtain a passivated board;

[0096] S3. The anti-fingerprint paint for color plates is coated on the surface of the passivation plate with a coating thickness of 20 μm, and then baked at 150° C. for 30 min to obtain a color plate.

[0097] The preparation process of the passivator is as follows:

[0098] In parts by weight, take 50 parts of water-based polyurethane resin, 140 parts of water, 15 parts of vinyl triacetoxy silane, 10 parts of filler, 10 parts of fluorozirconic acid, 13 parts of sodium tripolyphosphate, 3 parts of propyl trimethoxy silane, and 2 parts of sodium dodecyl sulfate, add the above raw materials into a mixer, and stir and mix at a speed of 300 r / min for 30 minutes.

[0099] The filler is composed of flake mica powder (325-400 meshes) and nano silicon dioxide in a mass ratio of 1:1.

[0100] The waterborne polyurethane resin is milky white, has a solid content (non-volatile content) of 49-51 wt %, and a viscosity (25° C.) of 500-2000 mPa·s, and was purchased from Yantai Wanhua Polyurethane Co., Ltd.

[0101] The color plates prepared by using the anti-fingerprint paints prepared in the above Examples 1-3 and Comparative Examples 1-6 were tested for self-repairing performance and anti-fingerprint performance;

[0102] Self-repair ability evaluation: Use a brass brush to brush the surface of the color plate back and forth 10 times at 25°C until obvious scratches appear. Then place the sample at 60°C for 5 minutes before evaluation. The scratches that are repaired by more than 80% are rated as excellent, those that are repaired by 50-80% are rated as medium, and those that are repaired by less than 50% are rated as poor.

[0103] Fingerprint resistance evaluation: Apply Vaseline to your finger and touch the surface of the color board to see if there are fingerprints left;

[0104] The results are shown in Table 1:

[0105] Table 1

[0106]

[0107] It can be seen from the data recorded in Table 1 that the paints obtained in Examples 1-3 have good mechanical properties, self-cleaning properties, self-repairing properties and fingerprint resistance. Specifically, it can be seen from the test results in Example 1 and Comparative Example 1, Example 2 and Comparative Example 2 that too high or too low a dosage of pyrrole in the preparation process of polypyrrole-modified titanium dioxide will have an adverse effect on the photocatalytic degradation performance. It can be seen from the test results in Example 1 and Comparative Example 3, Example 3 and Comparative Example 4 that too high or too low a dosage of polypyrrole-modified titanium dioxide will affect the mechanical properties of the coating. It can be seen from the test results in Example 1 and Comparative Example 5 that, compared with directly using titanium dioxide as a filler, the paint film prepared by polypyrrole-modified titanium dioxide has better mechanical properties, self-repairing properties and photocatalytic properties. It can be seen from the test results in Example 1 and Comparative Example 6 that the use of existing diols instead of the alkyl long-chain disulfide diols in this application will cause the paint film to lose its self-repairing properties and fingerprint resistance.

[0108] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0109] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A fingerprint-resistant paint for color plates, characterized in that: It includes the following raw materials in parts by weight:

2. The anti-fingerprint paint for color plates according to claim 1, characterized in that: Waterborne polyester resin is made by the following steps: Trihydroxypropane, alkyl long-chain disulfide glycol, phthalic anhydride, isophthalic acid, adipic acid and trimellitic anhydride are added into a reaction kettle, stirred at 120° C. for 10-20 min under nitrogen protection, a catalyst is added, and the reaction is kept at 220-250° C. until the acid value is less than 5 mgKOH / g, the temperature is reduced to 210° C. and vacuum is applied, the temperature is then reduced to 160° C. and trimellitic anhydride is added, the reaction is carried out at 170-175° C. until the acid value is 26-30 mgKOH / g, and then ethylene glycol butyl ether is added to obtain an aqueous polyester resin.

3. The anti-fingerprint paint for color plates according to claim 2, characterized in that: The mass ratio of trihydroxypropane, alkyl long-chain disulfide glycol, phthalic anhydride, isophthalic acid, adipic acid, trimellitic anhydride, catalyst and ethylene glycol butyl ether is 8-10:23-30:3-5:10-18:6-13:7-10:0.08-0.15:25-30, and the mass ratio of trimellitic anhydride added successively is 1:

2.

4. The anti-fingerprint paint for color plates according to claim 2, characterized in that: Alkyl long-chain dithiodiols are prepared from 3,3'-dithiobispropylamine and long-chain alkyl glycidyl ether by a ring-opening reaction.

5. The anti-fingerprint paint for color plates according to claim 4, characterized in that: The long-chain alkyl glycidyl ether is at least one of dodecyl glycidyl ether, glycidyl hexadecyl ether and octadecyl glycidyl ether.

6. The anti-fingerprint paint for color plates according to claim 1, characterized in that: The preparation process of the fingerprint-resistant paint for the color plate is as follows: Add water-based polyester resin, polypyrrole-modified titanium dioxide, diethanolamine and deionized water into a stirring tank, add defoamer and wetting and leveling agent while stirring, add amino resin after stirring for 30 minutes, continue stirring for 30 minutes, add thickener, and continue stirring for 10 minutes to obtain fingerprint-resistant paint for color plates.

7. A color plate production process, characterized in that: The following steps are involved: S1, placing the metal substrate in a degreasing solution for degreasing treatment, and then washing with water and drying to obtain a pre-treated plate; S2, immersing the pre-treated plate in a passivation solution, performing passivation treatment, and obtaining a passivated plate; S3. Coat the surface of the passivation plate with the anti-fingerprint paint for color plates as described in any one of claims 1 to 6, with a coating thickness of 20 to 25 μm, and then bake at 140 to 160° C. for 30 min to obtain a color plate.

8. A color plate production process according to claim 7, characterized in that: The metal substrate is one of a cold-rolled steel sheet, an electro-galvanized steel sheet, a hot-dip galvanized steel sheet and an galvanized steel sheet.

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