A UV coating for plastic flat plate vacuum coating and its preparation and application

Abstract

The application belongs to the field of vacuum coating UV paint, and particularly relates to a UV paint for plastic flat plate vacuum coating and preparation and application thereof. The UV paint comprises a solvent, component A, component B and component C. The solvent is ethanol, the component A is a sulfur-containing end-vinyl polyurethane macromolecule, the component B is a silicon-containing end-vinyl polyurea macromolecule, and the component C is a mixture of 2-methoxy-4-vinyl phenol and dipropylene glycol diacrylate. The application uses non-toxic and harmless ethanol as a solvent, uses a polyurea macromolecule containing a vinyl group and an organic silicon segment and a sulfur-containing end-vinyl polyurethane macromolecule as main components, and uses a mixture of 2-methoxy-4-vinyl phenol and dipropylene glycol diacrylate as a comonomer to prepare a high-molecular coating on the surface of a plastic flat plate, the coating hardness is greater than 5H, the coating does not peel at a temperature above 450 DEG C, has strong bonding performance, and can resist high-temperature water boiling for hundreds of hours.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of vacuum coating UV paint, and particularly relates to a UV paint for vacuum coating of plastic flat plate and preparation and application thereof. BACKGROUND

[0002] With the development of plastic decorative coating and the continuous development of plastic metal products, vacuum coating technology is more and more applied to plastic metalized products, such as automobile spotlight reflector, automobile decorative parts, mobile phone shell, lamp parts, cosmetic box and daily small commodity fields, which has been widely recognized and applied. The metalized decoration of plastic not only can form good decoration and protection effect, but also can save a large amount of precious metal materials, and greatly reduce the product quality.

[0003] The polyurethane UV coating is currently widely used in vacuum coating, which has the characteristics of fast curing speed, energy saving and environmental protection. Most of the existing polyurethane UV coatings use dihydric alcohol or polyhydric alcohol as the main chain growth reactant, and small molecule alcohol as the chain extender. For example, patent CN201510895880.8 discloses a UV vacuum coating crack paint and a preparation method thereof. After the paint is cured by ultraviolet irradiation, the surface part of the painted part does not show a monotonous mirror effect, but shows a complex ice flower pattern effect. The adhesion of the paint is the same as that of conventional paint, and it also has water boiling resistance and artificial sweat resistance. Patent CN201510926887.1 provides a high solid content UV vacuum coating paint. The special monomer and resin are skillfully matched, and a unique preparation method is used to provide good wettability and leveling property. Even if a large area is sprayed on the metal surface, the mirror effect can also be achieved, and the paint is not easy to sag, and has good fullness.

[0004] Such products with polyurethane as the main coating component generally have the advantages of good coating film flexibility and low price, but most of the products have poor high temperature resistance and are difficult to withstand high temperature of more than 400 DEG C and long time high temperature boiling. And most of the UV coating products add leveling agents, wetting agents, defoaming agents and other additional additives, which increase the cost and reduce the coating film quality. SUMMARY

[0005] In view of the problems in the prior art, the present application provides a UV paint for vacuum coating of plastic flat plate, which is prepared by using polyurea macromolecules containing vinyl and organic silicon segments and vinyl polyurethane macromolecules with bis(2-aminophenyl) disulfide as a chain extender as main components. For the coating demand of plastic flat plate, the UV paint is coated by spin coating without adding leveling agents, wetting agents, defoaming agents and the like in the paint.

[0006] To achieve the above technical purposes, the technical scheme of the present application is as follows:

[0007] A UV coating for vacuum coating of plastic flat panels, the UV coating comprising a solvent, component A, component B, and component C; wherein the solvent is ethanol, component A is a sulfur-containing vinyl-terminated polyurethane macromolecule, component B is a silicon-containing vinyl-terminated polyurea macromolecule, and component C is a mixture of 2-methoxy-4-vinylphenol and tripropylene glycol diacrylate.

[0008] The mass ratio of the UV coating includes: component A 5-20%, component B 30-50%, component C 20-30%, with the balance being solvent, and the viscosity of the coating is 300-1000 mPa·s.

[0009] The preparation method of component A includes the following:

[0010] Weigh out the biomass diol, add a small amount of triethylenediamine catalyst until completely dissolved, then gradually add isophorone diisocyanate at 75°C until the hydroxyl groups react completely, then add the chain extender, and finally add the end-capping agent pentaerythritol triacrylate until the hydroxyl groups react completely to obtain component A;

[0011] Furthermore, the mass ratio of component A is: 20-25% isophorone diisocyanate, 65-68% biomass diol, 3-5% chain extender, and 4-10% pentaerythritol triacrylate.

[0012] In component A, IPDI undergoes a condensation reaction with cashew nutshell oil bio-based diol to form a short polyurethane chain. This chain is then extended using bis(2-aminophenyl)disulfide as a chain extender. Finally, a long chain is capped with pentaerythritol triacrylate containing three vinyl groups, resulting in a polyurethane long chain with six vinyl functional groups at both ends. The chain extender, bis(2-aminophenyl)disulfide, utilizes the bis(2-aminophenyl)disulfide bond as a chain extender, exhibiting stronger reactivity compared to traditional small-molecule diols. Furthermore, the SH bond forms hydrogen bonds during subsequent film formation, resulting in stronger crosslinking ability and improved coating film hardness, high-temperature resistance, and water resistance.

[0013] The biomass diol adopts cashew nut shell oil bio-based diol, specifically adopts the product of FX-9201 brand produced by Guangzhou Haoyi New Material Science and Technology Co., Ltd., and the hydroxyl value is 80 mgKOH / g. Due to the long aliphatic chain of cardanol, the cashew nut shell oil diol has strong hydrophobicity. This hydrophobic property provides excellent water resistance and lower water sensitivity in the isocyanate curing process, thereby improving the durability of the final polyurethane system. In addition, the cashew nut shell oil diol exhibits fast curing after curing with isocyanate, minimizes the amount of catalyst required, and achieves the purpose of short construction period. Unlike the polyols of soybean and castor oil, the cashew nut shell oil polyol has an aromatic structure, which can be converted into excellent heat resistance and acid and alkali resistance.

[0014] The preparation method of the component B comprises the following steps:

[0015] A certain amount of aminopropyl-terminated polydimethylsiloxane is weighed, a small amount of catalyst triethylenediamine is added for complete dissolution, toluene diisocyanate (TDI) is gradually added at 75°C until the amino group is completely reacted, then a chain extender is added until the hydroxyl group is completely reacted, and finally a blocking agent pentaerythritol triacrylate is added until the isocyanate group is completely reacted to obtain the component B;

[0016] Further, the mass ratio of the component B comprises toluene diisocyanate 30-35%, aminopropyl-terminated polydimethylsiloxane 55-58%, chain extender 4-5%, and pentaerythritol triacrylate 4-10%.

[0017] The isocyanate groups in TDI in the component B and the amino groups of the aminopropyl-terminated polydimethylsiloxane undergo condensation reaction to form a polyurea short chain, then the chain extender 1,4-butanediol is used for chain extension, and the pentaerythritol triacrylate with three vinyl groups is used for long-chain blocking, so that both ends of the polyurea are connected with the pentaerythritol triacrylate, and finally there are six vinyl functional groups on the polyurea long chain.

[0018] The chain extender is 1,4-butanediol.

[0019] The number average molecular weight of the aminopropyl-terminated polydimethylsiloxane is 1000-3000. The high-temperature resistance and boiling water resistance of the siloxane segment of the aminopropyl-terminated polydimethylsiloxane are much better than those of the alkane segment, and using the polyurea macromolecule containing vinyl and silicone segments as the main component of the coating can greatly improve the heat resistance and boiling water resistance.

[0020] The component C is a mixture of 2-methoxy-4-vinylphenol and tripropyleneglycol dipropylene acrylate, which mainly functions to improve the hardness and high-temperature resistance of the film material.

[0021] The UV coating is coated on the surface of the flat plate material by spin coating, and the flat plate material is one of polypropylene, polyvinyl chloride, polystyrene and polymethyl methacrylate. The spin coating rate is 1000-2000 r / min, and the spin coating time is 5-10 s.

[0022] The flat plate material is pretreated before spin coating, and the pretreatment is to spray a (triphenylphosphine) palladium acetate-DMF solution with a concentration of one thousandth on the surface of the flat plate material. This substance can greatly enhance the bonding force of the polymer coating and the plastic flat plate.

[0023] The curing process of the UV coating is to add 3-5% of the mass of the coating of a photoinitiator 1173 before use, to dry at 60-70℃ for 5-10 min after spin coating, and then to irradiate under a 500kw ultraviolet lamp for 4-5 min.

[0024] As can be seen from the above description, the present application has the following advantages:

[0025] 1. The UV coating prepared by the present application uses polyurea macromolecules containing vinyl and silicone segments and end-vinyl polyurethane macromolecules using bis(2-aminophenyl) disulfide as a chain extender as main components, and is coated on the surface of the flat plate material by spin coating, without the need to add leveling agents, wetting agents, defoaming agents, etc. in the coating.

[0026] 2. The present application uses a mixture of 2-methoxy-4-vinylphenol and tripropyleneglycol dipropylene acrylate as a UV copolymer, which can significantly increase the hardness and high temperature resistance of the polymer film.

[0027] 3. The present application prepares a high molecular coating on the surface of the plastic flat plate by spin coating, and the coating hardness is >5H, does not peel at 450℃ or above, has strong adhesion, and can withstand hundreds of hours of high temperature boiling.

[0028] 4. The present application uses a (triphenylphosphine) palladium acetate-DMF solution to spray the surface of the flat plate material, which effectively enhances the bonding force of the polymer coating and the plastic.

[0029] 5. The present application uses ethanol as a solvent, which is less toxic, low in cost, and friendly to the processing environment. DETAILED DESCRIPTION

[0030] The present application is described in detail in combination with the examples, but does not limit the claims of the present application.

[0031] The catalyst addition amount in the technical solution is not calculated in the ratio, and the catalyst addition amount is 0.5% of the total mass of the raw materials.

[0032] Example 1

[0033] A UV coating for plastic flat plate vacuum coating

[0034] Preparation of component A: according to the mass fraction, 65% biomass diol was weighed, a small amount of catalyst triethylenediamine was added until completely dissolved, 20% isophorone diisocyanate (IPDI) was gradually added at 75°C until the hydroxyl reaction was complete, then 5% chain extender bis(2-aminophenyl) disulfide was added, and finally 10% end-capping agent pentaerythritol triacrylate (PTEA) was added until the isocyanate group reaction was complete to obtain component A. Among them, the biomass diol uses the product of FX-9201 brand produced by Guangzhou Haoyi New Material Technology Co., Ltd., and the hydroxyl value of the cashew nut shell oil-based diol is 80 mgKOH / g.

[0035] Preparation of component B: 55% of aminopropyl-terminated polydimethylsiloxane was weighed, a small amount of catalyst triethylenediamine was added until completely dissolved, 30% toluene diisocyanate (TDI) was gradually added at 75°C until the amino reaction was complete, then 5% chain extender 1,4-butanediol was added until the hydroxyl reaction was complete, and finally 10% end-capping agent pentaerythritol triacrylate (PTEA) was added until the isocyanate group reaction was complete to obtain component B.

[0036] The UV coating is mixed and stirred with 5% component A, 30% component B, 10% 2-methoxy-4-vinylphenol, and 10% tripropyleneglycol dipropylene glycol diacrylate, and 45% ethanol until uniform, and the coating viscosity is 300-1000 mPa·s.

[0037] The polypropylene flat plate type material was pretreated by spraying a DMF solution of palladium acetate with a concentration of one thousandth of bis(triphenylphosphine) until the surface was completely wetted.

[0038] After dissolving, 3% of the UV coating mass of photoinitiator 1173 was added, and was coated on the surface of the polypropylene flat plate type material by spin coating at a spin coating rate of 1000 r / min and a spin coating time of 5 s. After spin coating, it was dried at 60°C for 5 min, and then irradiated under a 500 kw ultraviolet lamp for 4 min.

[0039] Example 2

[0040] A UV coating for plastic flat plate vacuum coating

[0041] Preparation of component A: 68% biomass diol was weighed according to the mass fraction, a small amount of catalyst triethylenediamine was added until completely dissolved, 25% isophorone diisocyanate (IPDI) was gradually added at 75°C until the hydroxyl reaction was complete, then 3% chain extender bis(2-aminophenyl) disulfide was added, and finally 4% end-capping agent pentaerythritol triacrylate (PTEA) was added until the isocyanate group reaction was complete to obtain component A. Among them, the biomass diol uses the product of FX-9201 brand produced by Guangzhou Haoyi New Material Technology Co., Ltd., and the hydroxyl value of the cashew nut shell oil bio-based diol is 80 mgKOH / g.

[0042] Preparation of component B: 55% aminopropyl-terminated polydimethylsiloxane was weighed, a small amount of catalyst triethylenediamine was added until completely dissolved, 30% toluene diisocyanate (TDI) was gradually added at 75°C until the amino reaction was complete, then 5% chain extender 1,4-butanediol was added until the hydroxyl reaction was complete, and finally 10% end-capping agent pentaerythritol triacrylate (PTEA) was added until the isocyanate group reaction was complete to obtain component B.

[0043] The UV coating is mixed and stirred until uniform, and the coating viscosity is 300-1000 mPa·s, with 20% component A, 40% component B, 15% 2-methoxy-4-vinylphenol, and 15% dipentaerythritol tripropylene glycol diacrylate, and 10% ethanol.

[0044] The polyvinyl chloride flat panel material is pretreated by spraying a DMF solution of palladium acetate bis(triphenylphosphine) with a concentration of one thousandth until the surface is completely wetted.

[0045] After the UV coating is dissolved, 3% photoinitiator 1173 by mass is added to the surface of the polyvinyl chloride flat panel material by spin coating at a speed of 2000 r / min for 10 s. After spin coating, it is dried at 70°C for 10 min, and then irradiated under a 500 kw ultraviolet lamp for 5 min.

[0046] Example 3

[0047] A UV coating for vacuum coating of plastic flat panels

[0048] Preparation of component A: 68% biomass diol was weighed according to the mass fraction, a small amount of catalyst triethylenediamine was added until completely dissolved, 25% isophorone diisocyanate (IPDI) was gradually added at 75°C until the hydroxyl reaction was complete, then 3% chain extender bis(2-aminophenyl) disulfide was added, and finally 4% end-capping agent pentaerythritol triacrylate (PTEA) was added until the isocyanate group reaction was complete to obtain component A. Among them, the biomass diol uses the product of FX-9201 brand produced by Guangzhou Haoyi New Material Technology Co., Ltd., and the hydroxyl value of the cashew nut shell oil-based diol is 80 mgKOH / g.

[0049] Preparation of component B: 58% aminopropyl-terminated polydimethylsiloxane was weighed, a small amount of catalyst triethylenediamine was added until completely dissolved, 30% toluene diisocyanate (TDI) was gradually added at 75°C until the amino reaction was complete, then 4% chain extender 1,4-butanediol was added until the hydroxyl reaction was complete, and finally 8% end-capping agent pentaerythritol triacrylate (PTEA) was added until the isocyanate group reaction was complete to obtain component B.

[0050] The UV coating was mixed and stirred with 10% component A, 50% component B, 10% 2-methoxy-4-vinylphenol, and 10% tripropyleneglycol dipropylene glycol diacrylate, and 20% ethanol until uniform.

[0051] The polystyrene flat panel material was pretreated by spraying a DMF solution of palladium acetate bis(triphenylphosphine) with a concentration of one thousandth until the surface was completely wetted.

[0052] After the UV coating was dissolved, 3% photoinitiator 1173 was added, and then it was coated on the surface of the polystyrene flat panel material by spin coating at a speed of 2000 r / min for 10 s. After spin coating, it was dried at 70°C for 10 min, and then irradiated under a 500kw ultraviolet lamp for 5 min.

[0053] Example 4

[0054] A UV coating for vacuum coating of plastic flat panels

[0055] Preparation of component A: 65% biomass diol was weighed according to the mass fraction, a small amount of catalyst triethylenediamine was added until completely dissolved, 20% isophorone diisocyanate (IPDI) was gradually added at 75°C until the hydroxyl reaction was complete, then 5% chain extender bis(2-aminophenyl) disulfide was added, and finally 10% end-capping agent pentaerythritol triacrylate (PTEA) was added until the isocyanate group reaction was complete to obtain component A. Among them, the biomass diol uses the product of FX-9201 brand produced by Guangzhou Haoyi New Material Technology Co., Ltd., and the hydroxyl value of the cashew nut shell oil-based diol is 80 mgKOH / g.

[0056] Preparation of component B: 55% aminopropyl-terminated polydimethylsiloxane was weighed, a small amount of catalyst triethylenediamine was added until completely dissolved, 30% toluene diisocyanate (TDI) was gradually added at 75°C until the amino reaction was complete, then 5% chain extender 1,4-butanediol was added until the hydroxyl reaction was complete, and finally 10% end-capping agent pentaerythritol triacrylate (PTEA) was added until the isocyanate group reaction was complete to obtain component B.

[0057] The UV coating was mixed and stirred with 10% component A, 50% component B, 10% 2-methoxy-4-vinylphenol, and 10% tripropyleneglycol dipropylene glycol diacrylate, and 20% ethanol until uniform.

[0058] The polymethyl methacrylate flat panel material was pretreated by spraying a DMF solution of palladium acetate bis(triphenylphosphine) with a concentration of one thousandth until the surface was completely wetted.

[0059] After dissolution, 3% photoinitiator 1173 of the UV coating was added to the surface of the polymethyl methacrylate flat panel material by spin coating at a speed of 2000 r / min for 10 s. After spin coating, it was dried at 70°C for 10 min, and then irradiated under a 500 kw ultraviolet lamp for 5 min.

[0060] Comparative Example 1

[0061] A UV coating for vacuum coating of plastic flat panels

[0062] Preparation of component A: 65% biomass diol was weighed according to the mass fraction, a small amount of catalyst triethylenediamine was added until completely dissolved, 20% isophorone diisocyanate (IPDI) was gradually added at 75°C until the hydroxyl reaction was complete, then 5% chain extender bis(2-aminophenyl)disulfide was added, and finally 10% end-capping agent pentaerythritol triacrylate (PTEA) was added until the isocyanate group reaction was complete to obtain component A. Among them, the biomass diol uses the product of FX-9201 brand produced by Guangzhou Haoyi New Material Technology Co., Ltd., and the hydroxyl value of the cashew nut shell oil-based diol is 80 mgKOH / g.

[0063] The UV coating was mixed and stirred with 35% component A, 10% 2-methoxy-4-vinyl phenol and 10% tripropylene glycol diacrylate, and 45% ethanol until uniform.

[0064] After the UV coating was dissolved, 3% photoinitiator 1173 was added, and then it was coated on the surface of the polypropylene flat panel material by spin coating at a speed of 1000 r / min and a time of 5 s. After spin coating, it was dried at 60°C for 5 min, and then irradiated under a 500 kw ultraviolet lamp for 4 min.

[0065] Comparative example 2

[0066] A UV coating for vacuum coating of plastic flat panels

[0067] Preparation of component A: 65% biomass diol was weighed according to the mass fraction, a small amount of catalyst triethylenediamine was added until completely dissolved, 20% isophorone diisocyanate (IPDI) was gradually added at 75°C until the hydroxyl reaction was complete, then 5% chain extender 1,4-butanediol was added until the hydroxyl reaction was complete, and finally 10% end-capping agent pentaerythritol triacrylate (PTEA) was added until the isocyanate group reaction was complete to obtain component A. Among them, the biomass diol uses the product of FX-9201 brand produced by Guangzhou Haoyi New Material Technology Co., Ltd., and the hydroxyl value of the cashew nut shell oil-based diol is 80 mgKOH / g.

[0068] Preparation of component B: 55% aminopropyl-terminated polydimethylsiloxane was weighed, a small amount of catalyst triethylenediamine was added until completely dissolved, 30% toluene diisocyanate (TDI) was gradually added at 75°C until the amino reaction was complete, then 5% chain extender 1,4-butanediol was added until the hydroxyl reaction was complete, and finally 10% end-capping agent pentaerythritol triacrylate (PTEA) was added until the isocyanate group reaction was complete to obtain component B.

[0069] The UV coating is mixed and stirred according to 5% component A, 30% component B, 10% 2-methoxy-4-vinylphenol and 10% tripropyleneglycol diacrylate, 45% ethanol until uniform.

[0070] The polyvinyl chloride flat panel type material is pretreated by spraying a DMF solution of bis (triphenylphosphine) palladium acetate with a concentration of one thousandth until the surface is completely wetted.

[0071] After dissolving, 3% of the UV coating by mass of the photoinitiator 1173 is added to the surface of the polypropylene flat panel type material by spin coating at a speed of 1000 r / min for 5 s. After spin coating, the material is dried at 60°C for 5 min and then irradiated under a 500 kw ultraviolet lamp for 4 min.

[0072] Comparative Example 3

[0073] A UV coating for vacuum coating of plastic flat panels

[0074] Preparation of component A: 65% biomass diol is weighed according to mass fraction, a small amount of catalyst triethylenediamine is added until completely dissolved, 20% isophorone diisocyanate (IPDI) is gradually added at 75°C until the hydroxyl reaction is complete, then 5% chain extender 1, 4-butanediol is added until the hydroxyl reaction is complete, and finally 10% end-capping agent pentaerythritol triacrylate (PTEA) is added until the isocyanate group reaction is complete to obtain component A. The biomass diol is FX-9201 produced by Guangzhou Haoyi New Material Technology Co., Ltd., and the hydroxyl value of the cashew nut shell oil bio-based diol is 80 mgKOH / g.

[0075] Preparation of component B: 55% aminopropyl-terminated polydimethylsiloxane is weighed, a small amount of catalyst triethylenediamine is added until completely dissolved, 30% toluene diisocyanate (TDI) is gradually added at 75°C until the amino reaction is complete, then 5% chain extender 1, 4-butanediol is added until the hydroxyl reaction is complete, and finally 10% end-capping agent pentaerythritol triacrylate (PTEA) is added until the isocyanate group reaction is complete to obtain component B.

[0076] The UV coating is mixed and stirred according to 5% component A, 30% component B, 10% 2-methoxy-4-vinylphenol and 10% tripropyleneglycol diacrylate, 45% ethanol until uniform.

[0077] The polyvinyl chloride flat panel type material is pretreated by spraying a DMF solution of bis (triphenylphosphine) palladium acetate with a concentration of one thousandth until the surface is completely wetted.

[0078] The UV coating with 3% of the photoinitiator 1173 by mass was added after dissolution, and was coated on the surface of the polypropylene flat panel material by spin coating at a spin coating rate of 1000 r / min and a spin coating time of 5 s. After spin coating, drying was performed at 60°C for 5 min, and then irradiation was performed under a 500 kw ultraviolet lamp for 4 min.

[0079] Comparative Example 4

[0080] A UV coating for vacuum coating of a plastic flat panel

[0081] Preparation of Component A: 65% of biomass diol was weighed according to the mass fraction, a small amount of catalyst triethylenediamine was added until complete dissolution, 20% of isophorone diisocyanate (IPDI) was gradually added dropwise at 75°C until the hydroxyl reaction was complete, then 5% of chain extender 1, 4-butanediol was added until the hydroxyl reaction was complete, and finally 10% of end-capping agent pentaerythritol triacrylate (PTEA) was added until the isocyanate group reaction was complete to obtain Component A. Among them, the biomass diol uses the product of FX-9201 brand produced by Guangzhou Haoyi New Material Technology Co., Ltd., and the hydroxyl value of the cashew nut shell oil bio-based diol is 80 mgKOH / g.

[0082] Preparation of Component B: 55% of aminopropyl-terminated polydimethylsiloxane was weighed, a small amount of catalyst triethylenediamine was added until complete dissolution, 30% of toluene diisocyanate (TDI) was gradually added dropwise at 75°C until the amino reaction was complete, then 5% of chain extender 1, 4-butanediol was added until the hydroxyl reaction was complete, and finally 10% of end-capping agent pentaerythritol triacrylate (PTEA) was added until the isocyanate group reaction was complete to obtain Component B.

[0083] The UV coating was mixed and stirred with 5% of Component A, 30% of Component B, 20% of tripropylene glycol dipropylene acrylate as Component C, and 45% of ethanol until uniform.

[0084] The UV coating with 3% of the photoinitiator 1173 by mass was added after dissolution, and was coated on the surface of the polypropylene flat panel material by spin coating at a spin coating rate of 1000 r / min and a spin coating time of 5 s. After spin coating, drying was performed at 60°C for 5 min, and then irradiation was performed under a 500 kw ultraviolet lamp for 4 min.

[0085] Examples 1-4 and Comparative Examples 1-4 were tested and compared, and the data are as follows:

[0086]

[0087]

[0088] Among them:

[0089] Pencil hardness: The test piece is placed upward and fixed, a pencil is forced to scratch the test piece at an angle of 45°, without breaking the lead, and moves forward at a constant speed of about 1 cm. The scratching speed is 1 mm / s, after scratching once, the tip of the lead should be re-ground, the test is repeated 5 times with the same hardness of the pencil. 2) The damage of the coating film is observed to evaluate, when only 2 or less than 2 tests of 5 tests can see the substrate or the primer coating film, a pencil with a hardness mark of one bit larger should be used to perform the same test, when the damage of the coating film reaches more than 2 times (per 5 tests), the hardness mark of the pencil can be read, and the next hardness mark of the pencil hardness mark is recorded.

[0090] 450℃ high temperature resistance test: the plastic plate with the cured coating film is placed in an oven at 450℃ for 30 min, and the film properties are observed.

[0091] High temperature boiling test: the plastic plate with the cured coating film is placed in water and heated to 90℃ for 300 h, and the film properties are observed.

[0092] It can be understood that the above specific description of the present application is only used to illustrate the present application and is not limited to the technical solutions described in the embodiments of the present application. Those skilled in the art should understand that the present application can still be modified or replaced equivalently to achieve the same technical effect; as long as it meets the use needs, it is within the protection scope of the present application.

Claims

1. A UV coating for vacuum coating of plastic flat panels, characterized in that: The UV coating is composed of a solvent, component A, component B and component C; wherein the solvent is ethanol, the component A is a sulfur-containing end-vinyl polyurethane macromolecule, the component B is a silicon-containing end-vinyl polyurea macromolecule, and the component C is a mixture of 2-methoxy-4-vinyl phenol and tripropyleneglycol dipropenylate.

2. The UV coating for vacuum coating of plastic flat panels according to claim 1, characterized in that: The mass ratio of the UV coating is: component A 5-20%, component B 30-50%, component C 20-30%, and the rest is solvent, and the viscosity of the coating is 300-1000 mPa·s.

3. The UV coating for vacuum coating of plastic flat panels according to claim 1, characterized in that: The preparation method of the component A comprises the following steps: After a small amount of catalyst triethylenediamine is added to completely dissolve the biomass dihydric alcohol, isophorone diisocyanate (IPDI) is gradually added dropwise at 75℃ until the hydroxyl reaction is complete, then a chain extender is added, and finally a capping agent pentaerythritol triacrylate is added until the isocyanate group reaction is complete to obtain the component A; The mass ratio of the component A is: isophorone diisocyanate 20-25%, biomass dihydric alcohol 65-68%, chain extender 3-5%, and pentaerythritol triacrylate 4-10%; The chain extender uses bis(2-aminophenyl)disulfide; and the biomass dihydric alcohol uses cashew nut shell oil bio-based dihydric alcohol.

4. The UV coating for vacuum coating of plastic flat panels according to claim 1, characterized in that: The preparation method of the component B comprises the following steps: After a small amount of catalyst triethylenediamine is added to completely dissolve the amino propyl capped polydimethylsiloxane, toluene diisocyanate (TDI) is gradually added dropwise at 75℃ until the amino reaction is complete, then a chain extender is added until the hydroxyl reaction is complete, and finally a capping agent pentaerythritol triacrylate is added until the isocyanate group reaction is complete to obtain the component B; The mass ratio of the component B comprises: toluene diisocyanate 30-35%, amino propyl capped polydimethylsiloxane 55-58%, chain extender 4-5%, and pentaerythritol triacrylate 4-10%.

5. The UV coating for vacuum coating of plastic flat panels according to claim 4, characterized in that: The number average molecular weight of the amino propyl capped polydimethylsiloxane is 1000-3000.

6. The UV coating for vacuum coating of plastic flat panels according to claim 1, characterized in that: The mass ratio of 2-methoxy-4-vinyl phenol and tripropyleneglycol dipropenylate in the component C is 1:

1.

7. The method for applying UV coating to plastic flat panels for vacuum coating, according to claim 1, characterized in that: The UV coating is coated on the surface of a planar panel material in a spin coating manner, and the planar panel material is one of polypropylene, polyvinyl chloride, polystyrene and polymethyl methacrylate, the spin coating rate is 1000-2000 r / min, and the spin coating time is 5-10 s.

8. The method for applying UV paint to a plastic flat panel for vacuum coating according to claim 7, wherein: The planar panel material needs to be pretreated before spin coating, and the pretreatment is to spray a (triphenylphosphine) palladium acetate-DMF solution with a concentration of one thousandth on the surface of the planar panel material.

9. The UV coating for vacuum coating of plastic flat panels according to claim 1, characterized in that: The curing process of the UV coating is to add 3-5% of a photo initiator 1173 by mass of the coating before use, to dry at 60-70℃ for 5-10 min after spin coating, and then to irradiate under a 500 kw ultraviolet lamp for 4-5 min.

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