Ultraviolet-cured anti-fingerprint coating as well as preparation method and application thereof

Abstract

The invention relates to the field of coatings, and discloses an ultraviolet curing anti-fingerprint coating as well as a preparation method and application thereof. The ultraviolet curing anti-fingerprint coating is prepared from 90 to 99 parts of photocuring coating mother liquor and 1 to 10 parts of double-bond fluorine-containing silicon-containing anti-fingerprint acrylic resin. The coating obtained by curing the coating has excellent wear resistance and scratch resistance while ensuring the flexibility, and the long-acting fingerprint resistance of the coating can be greatly improved; and meanwhile, the coating has excellent transparency. In addition, the coating can be cured in an ultraviolet curing mode, and the curing speed is high; no heat is generated in the purple light external curing process, so that the ultraviolet curing agent is particularly suitable for temperature-sensitive substances; in addition, ultraviolet curing does not contain solvents or volatile organic compounds, and is safer and more environment-friendly.

Description

Technical Field

[0001] The invention relates to the field of coatings, and in particular to an ultraviolet light-cured anti-fingerprint coating and a preparation method and application thereof. Background Art

[0002] During the use of 3C electronic products, the touch panel is easily contaminated by pollutants such as grease and sweat on the surface of human finger skin when it is exposed, thus leaving fingerprints on the surface of the touch panel, seriously affecting the appearance. Fingerprints are different from general pollutants and have complex chemical compositions, so the coating on the surface of the touch panel needs to have higher anti-fouling properties. Moreover, electronic products such as mobile phones are used frequently in daily life, so the coating surface is required to have not only hydrophobic and oleophobic anti-fouling and anti-fingerprint properties, but also to be able to withstand long-term external wiping damage and maintain long-term easy-to-clean anti-fingerprint properties.

[0003] In view of this, some researchers have used the sol-gel method to introduce silica structure into the coating. They have used the low surface energy characteristics of silica and its high wear resistance and hardness to improve the coating's long-lasting anti-fingerprint properties. However, 3C products such as mobile phones are made of heat-sensitive substrates, and high-temperature thermal curing will damage the heat-sensitive substrates.

[0004] On the other hand, for touch screens, since they need to display images, the anti-fingerprint coating is required to have excellent transparency so as not to affect the user experience of the product. However, in the prior art, many anti-fingerprint coatings have good anti-fingerprint effects due to the addition of different anti-fingerprint functional fillers, but at the same time, the transparency of the coating is also affected, so further improvement is needed. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a UV-curable anti-fingerprint coating and its preparation method and application. The present invention realizes the hydrophobic and oleophobic properties of the coating by simultaneously introducing fluorine segments and silicon segments into the acrylic resin molecular chain, so that the coating can reduce fingerprints and other grease residues; at the same time, the anti-fingerprint acrylic resin of the present invention contains double bonds, which can participate in the photocrosslinking reaction, and can firmly fix the functional groups on the coating, while ensuring the flexibility of the coating, providing excellent wear resistance and scratch resistance, greatly improving the long-term anti-fingerprint performance of the coating; the double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin of the present invention can significantly improve the transparency of the coating. The coating of the present invention is cured by UV curing, and the curing speed is fast; and the UV curing process does not generate heat, which is particularly suitable for temperature-sensitive substances; in addition, UV curing does not contain solvents or volatile organic compounds, and is safe and environmentally friendly.

[0006] The specific technical scheme of the present invention is: In a first aspect, the present invention provides an ultraviolet light-curing anti-fingerprint coating, which comprises the following raw materials in parts by weight (total amount is 100 parts): 90-99 parts of a photocuring coating mother solution and 1-10 parts of a double-bond, fluorine-containing, and silicon-containing anti-fingerprint acrylic resin.

[0007] In the present invention, the double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin is used as the main structure of the coating, which has many advantages such as anti-fingerprint, high strength, wear resistance, corrosion resistance, etc. Specifically, the present invention realizes the hydrophobic and oleophobic properties of the coating by simultaneously introducing fluorine segments and silicon segments into the acrylic resin molecular chain, so that the coating can reduce fingerprints and other grease residues and is easy to clean. At the same time, through the special design of the monomers and proportions of the double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin, it is possible to provide excellent wear resistance and scratch resistance while ensuring the flexibility of the coating, which is crucial for anti-fingerprint coatings because it needs to remain intact in an environment of frequent touch and use.

[0008] On the other hand, the double-bond-containing, fluorine-containing, and silicon-containing anti-fingerprint acrylic resin of the present invention can significantly improve the transparency of the coating compared with the conventional fluorine hyperbranched polymer in the prior art. The reason is that the conventional fluorine hyperbranched polymer is very easy to form aggregation in the resin matrix, forming an optically heterogeneous region between the two phases, thereby reducing the light transmittance.

[0009] In addition, the coating of the present invention contains a photocurable coating mother liquor, so it can be cured by ultraviolet light curing. The ultraviolet light curing speed is fast and can be quickly cured in a short time. It is suitable for high-speed production lines and application scenarios that require immediate curing. At the same time, the ultraviolet light curing process does not generate heat, so it will not cause thermal deformation of the coating and the substrate, which makes it particularly suitable for temperature-sensitive materials such as plastic films. In addition, ultraviolet light curing does not require the use of solvents or volatile organic compounds, which can reduce pollution to the environment and is beneficial to human health and safety.

[0010] Preferably, the synthetic monomers of the double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin include: 18-23 parts of methyl methacrylate, 25-30 parts of hydroxyethyl methacrylate, 15-35 parts of anti-fingerprint functional monomers, and 28-35 parts of ethyl isocyanate acrylate.

[0011] The invention uses methyl methacrylate, hydroxyethyl methacrylate and anti-fingerprint functional monomer as raw materials, and obtains double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin by free radical random copolymerization under the action of an initiator, and then utilizes the hydroxyl group contained in hydroxyethyl methacrylate to add isocyanate acrylate, a double-bond monomer, and the isocyanate group and the hydroxyl group of the two undergo acylation reaction, successfully introducing the double-bond functional group into the anti-fingerprint acrylic resin system, and then preparing the double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin. Since the anti-fingerprint acrylic resin contains double bonds, it can participate in the photocrosslinking reaction together when the coating is ultraviolet light cured, so that the functional group is firmly fixed on the coating, and the long-term anti-fingerprint performance of the coating can be greatly improved.

[0012] Further preferably, the raw materials of the double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin include: 18-23 parts of methyl methacrylate, 25-30 parts of hydroxyethyl methacrylate, 15-35 parts of anti-fingerprint functional monomer, 28-35 parts of isocyanate ethyl acrylate, 2-5 parts of initiator, 0.5-1 part of catalyst, and the remainder of solvent.

[0013] Preferably, the anti-fingerprint functional monomers are silicone methacrylate and tridecafluorooctyl methacrylate.

[0014] The short-chain tridecafluorooctyl methacrylate selected in the present invention is more easily degraded than the long-chain fluorinated acrylate compound. The silicon-containing polymer itself has low toxicity and can also replace the long-chain fluorinated polymer with poor biodegradability, which is more environmentally friendly.

[0015] More preferably, the anti-fingerprint functional monomer contains 40-80 mol% methacrylate.

[0016] The present invention finds that the ratio of fluorine-containing monomers and silicon-containing monomers in the anti-fingerprint functional monomer has a significant effect on the anti-fingerprint effect of the final coating under long-term external wiping damage. Specifically: Compared with a single fluorine-containing coating and a single silicon-containing coating, the anti-fouling property of the silicon-containing fluorine-containing coating is better, because when the two components are doped, the interface layer has both the excellent lubricity of siloxane and the excellent hydrophobic and oleophobic properties of the fluorine segment, which plays a synergistic effect. In the process of optimizing the ratio of the two, the present invention tried the molar fractions of silicon-containing monomers to be 80%, 60% and 40%, respectively. It was found that the anti-fouling performance first increased and then decreased, and the silicon monomer accounted for 60% when it was optimal. The reason for this may be that with the excess of fluorine segments, the creep properties of the silicon segments in the anti-fingerprint acrylic resin are affected. The fluoroalcohol segments, due to their high rigidity and strong hydrophobicity, limit the free rotation and displacement between molecules, resulting in a decrease in the dynamic creep recovery performance of the entire material system. Therefore, in the face of repeated smearing or wiping of external loads, the restoring force of the resin coating is weakened, which is manifested as impaired durability, that is, a decrease in the number of graffiti resistance. On this basis, the content of double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin in the coating was increased. The results showed that the anti-graffiti property of the coating was not significantly improved. This may be because the siloxane segments and fluorine segments on the surface of the coating have reached a fully enriched state, and their distribution density is close to the saturation threshold. It is difficult for the newly added segments to find enough free space to embed. Therefore, the improvement in anti-graffiti property is minimal, and the overall cost of the coating will increase instead.

[0017] Preferably, in the double-bond, fluorine-containing, and silicon-containing anti-fingerprint acrylic resin, the solvent is selected from ethyl acetate and butyl acetate; the initiator is selected from tert-butyl perbenzoate, di-tert-amyl peroxide, and di-tert-butyl peroxide; and the catalyst is selected from dibutyltin dilaurate and dibutyltin sulfide.

[0018] Preferably, the raw materials of the photocurable coating mother solution include: 40-60 parts of trimethylolpropane triacrylate, 20-30 parts of epoxy resin, 15-27 parts of solvent, and 1-5 parts of photoinitiator.

[0019] Preferably, in the photocurable coating mother liquor, the epoxy resin is selected from bisphenol A epoxy acrylate resin and bisphenol epoxy acrylate; the solvent is selected from ethyl acetate and butyl acetate; the photoinitiator is selected from 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholine-1-propanone and 2-hydroxy-2-methyl-1-phenyl-1-propanone.

[0020] In a second aspect, the present invention provides a method for preparing a UV-curable anti-fingerprint coating, which specifically comprises the following steps: 1) Preparation of photocurable coating mother solution: Bisphenol A epoxy acrylic resin, trimethylolpropane triacrylate, photoinitiator and solvent are uniformly mixed to obtain photocurable coating mother solution.

[0021] 2) Preparation of double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin: add methyl methacrylate, hydroxyethyl methacrylate and an initiator to a solvent and mix well, heat to react, add an anti-fingerprint functional monomer and a catalyst to continue the reaction, concentrate, add the concentrated solution to a purified solution for precipitation, and dry; mix the obtained product with a solvent, heat, add isocyanate ethyl acrylate dropwise, add a catalyst to react, concentrate, add the concentrated solution to a purified solution for precipitation, and dry.

[0022] The double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin of the present invention is prepared by a free radical random copolymerization reaction: methyl methacrylate, hydroxyethyl methacrylate and an anti-fingerprint functional monomer are dissolved in a solvent to form a uniform mixture, and then under the action of an initiator, the double bonds in the monomers are attacked by free radicals, thereby generating free radical intermediates. These free radical intermediates then continuously react with monomer molecules to generate longer and longer polymer chains to obtain a fluorine-containing and silicon-containing anti-fingerprint acrylic resin, and then isocyanate ethyl acrylate is selected as a double-bond monomer, and an acylation reaction between a hydroxyl group and an isocyanate group is used to synthesize a double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin, so that the anti-fingerprint acrylic resin participates in a photocrosslinking reaction when the coating is ultraviolet-cured, and the anti-fouling chain segment is more firmly fixed on the coating surface. The preparation method of the double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin of the present invention is completed in two steps, the process is simple and easy, the synthesis conversion rate is high, and it has a broad industrialization prospect.

[0023] Preferably, in step 2), the concentration and precipitation are repeated multiple times.

[0024] Preferably, in step 2), the purified liquid is selected from n-hexane, n-pentane, n-heptane and n-octane.

[0025] In a third aspect, the present invention provides an application of the above-mentioned UV-curable anti-fingerprint coating in the preparation of a UV-curable anti-fingerprint coating, which comprises: mixing a double-bond, fluorine-containing, and silicon-containing anti-fingerprint acrylic resin with a photocurable coating mother liquor, coating the resin on the surface of a substrate, drying the resin, and then curing the resin by UV light to obtain a UV-curable anti-fingerprint coating.

[0026] Preferably, the drying time is 50-70°C and the time is 1-5mmin.

[0027] Compared with the prior art, the beneficial effects of the present invention are: (1) The present invention realizes the hydrophobic and oleophobic properties of the coating by simultaneously introducing fluorine segments and silicon segments into the acrylic resin molecular chain, so that the coating can reduce fingerprints and other grease residues and is easy to clean. At the same time, the anti-fingerprint acrylic resin of the present invention introduces double bonds through acylation reaction, so that they can participate in the photocrosslinking reaction together, firmly fix the functional groups on the coating, and can provide excellent wear resistance and scratch resistance while ensuring the flexibility of the coating, thereby greatly improving the long-term anti-fingerprint performance of the coating.

[0028] (2) Compared with conventional fluorine-containing hyperbranched polymers, the double-bond-containing, fluorine-containing, and silicon-containing anti-fingerprint acrylic resin of the present invention can significantly improve the transparency of the coating.

[0029] (3) The coating of the present invention can be cured by ultraviolet light curing, which has a fast ultraviolet light curing speed and is suitable for high-speed production lines and application scenarios that require instant curing. At the same time, the ultraviolet light curing process does not generate heat, so it will not cause thermal deformation of the coating and the substrate, and is particularly suitable for temperature-sensitive materials. In addition, ultraviolet light curing does not require the use of solvents or volatile organic compounds, which can reduce pollution to the environment and is beneficial to human health and safety.

[0030] (4) The present invention uses acrylic resin as the material matrix, and the prepared coating has high light transmittance and low haze, and has strong yellowing resistance and aging resistance, which can meet the daily needs of 3C products. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the embodiments.

[0032] Overall embodiment First, a UV-curable anti-fingerprint coating comprises the following raw materials in parts by weight (total amount is 100 parts): 90-99 parts of a photocurable coating mother solution, 1-10 parts of a double-bond, fluorine-containing, and silicon-containing anti-fingerprint acrylic resin. The synthetic monomers of the double-bond, fluorine-containing, and silicon-containing anti-fingerprint acrylic resin comprise: 18-23 parts of methyl methacrylate, 25-30 parts of hydroxyethyl methacrylate, 15-35 parts of an anti-fingerprint functional monomer, and 28-35 parts of ethyl isocyanate acrylate; the anti-fingerprint functional monomers are methacrylate silicone and methacrylate tridecafluorooctyl ester.

[0033] In some preferred implementation cases, the proportion of methacrylate silicone in the anti-fingerprint functional monomer is 40-80 mol%.

[0034] In some preferred implementation cases, the raw materials of the double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin include: 18-23 parts of methyl methacrylate, 25-30 parts of hydroxyethyl methacrylate, 15-35 parts of anti-fingerprint functional monomer, 28-35 parts of ethyl isocyanate acrylate, 2-5 parts of initiator, 0.5-1 part of catalyst, and the remainder of solvent.

[0035] In some more preferred implementation cases, the double-bond-containing, fluorine-containing, and silicon-containing anti-fingerprint acrylic resin, the solvent is selected from ethyl acetate and butyl acetate; the initiator is selected from tert-butyl perbenzoate, di-tert-amyl peroxide, and di-tert-butyl peroxide; and the catalyst is selected from dibutyltin dilaurate and dibutyltin sulfide.

[0036] In some preferred implementation cases, the raw materials of the photocurable coating mother solution include: 40-60 parts of trimethylolpropane triacrylate, 20-30 parts of epoxy resin, 15-27 parts of solvent, and 1-5 parts of photoinitiator.

[0037] In some more preferred implementation cases, in the photocurable coating mother liquor, the epoxy resin is selected from bisphenol A type epoxy acrylate resin and bisphenol epoxy acrylate; the solvent is selected from ethyl acetate and butyl acetate; the photoinitiator is selected from 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholine-1-propanone and 2-hydroxy-2-methyl-1-phenyl-1-propanone.

[0038] Secondly, a method for preparing a UV-curable anti-fingerprint coating comprises the following steps: 1) Preparation of photocurable coating mother solution: Bisphenol A epoxy acrylic resin, trimethylolpropane triacrylate, photoinitiator and solvent are uniformly mixed to obtain photocurable coating mother solution.

[0039] 2) Preparation of double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin: Pour the solvent into a four-necked round-bottom flask, continuously introduce nitrogen and heat the system to the specified temperature and reflux; Mix 18-23 parts by weight of methyl methacrylate, 25-30 parts by weight of hydroxyethyl methacrylate and 2-5 parts by weight of initiator and slowly drip into the four-necked flask through a constant pressure tetrafluoroethylene funnel, and control the dripping time to be 2.5-3h; After the mixture is dripped, keep it warm for 8-10h, and add the initiator every 2-4h during the insulation period. After the reaction is completed, cool the resin and discharge the material; Add 15-35 parts by weight of anti-fingerprint functional monomers to the synthesized resin. Drop 0.5-1 parts by weight of catalyst at 70-90℃; Then concentrate the synthesized anti-fingerprint acrylic resin by rotary evaporation, slowly pour the concentrate into the purified solution for precipitation, repeat the precipitation and dissolution several times to obtain the purified product, and put it into a vacuum oven at 70-90℃ for drying. Add anti-fingerprint acrylic resin and solvent mixture to a four-necked round-bottom flask, start stirring and heating, heat to a constant temperature of 70-90°C, then slowly drip 28-35 parts by weight of isocyanate ethyl acrylate monomer solution, and control the dripping time within 30 minutes. After the dripping is completed, add 0.5-1 parts by weight of catalyst, keep warm for 8-10 hours, and after the reaction is completed, wait for the resin to cool down before discharging. Then, concentrate the synthesized double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin by rotary evaporation, slowly pour the concentrated solution into the purified solution for precipitation, repeat the precipitation and dissolution several times to obtain the purified product, and put it into a 70-90°C vacuum oven for drying to obtain a double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin.

[0040] In some preferred implementation cases, in step 2), the purified liquid is selected from n-hexane, n-pentane, n-heptane and n-octane.

[0041] Finally, a preparation method of a UV-curable anti-fingerprint coating comprises: mixing a double-bond, fluorine-containing, and silicon-containing anti-fingerprint acrylic resin with a photocurable coating mother liquor, coating the resin on the surface of a substrate, drying the resin, and curing the resin by UV irradiation to obtain a UV-curable anti-fingerprint coating.

[0042] In some preferred implementation cases, the drying time is 50-70° C. and the time is 1-5 min.

[0043] Specific Examples and Comparative Examples Preparation example of anti-fingerprint acrylic resin: Comparative Example 1 (anti-fingerprint acrylic resin containing double bonds and silicon) Pour 20g of butyl acetate into a four-necked round-bottom flask, continue to introduce nitrogen, and heat the system to the specified temperature and reflux; mix 20g of methyl methacrylate, 35.75g of hydroxyethyl methacrylate and 2g of tert-butyl perbenzoate and slowly drip into the four-necked flask through a constant pressure tetrafluoroethylene funnel for 3h; keep the mixture warm for 9h after dripping, add 0.5g of tert-butyl perbenzoate every 3h during the insulation period, twice in total, cool the resin after the reaction is completed, and discharge the material; add 23.7g of methyl methacrylate silicone to the synthesized resin. Drop 0.5g of dibutyltin dilaurate at 80℃; then concentrate the synthesized silicon-containing anti-fingerprint acrylic resin by rotary evaporation, slowly pour the concentrate into n-hexane for precipitation, repeat the precipitation and dissolution 3 times to obtain the purified product, and put it into a vacuum oven at 80℃ for drying. Add 20g of silicon-containing anti-fingerprint acrylic resin and 80g of butyl acetate mixture to a four-necked round-bottom flask, start stirring and heating, the speed is 100rpm, and the temperature is heated to 80℃. Then slowly drop 31g of ethyl isocyanate acrylate solution with a monomer concentration of 15%, and the drop time is 30min. After the drop is completed, add 0.5g of dibutyltin dilaurate, keep warm for 9h, and after the reaction is completed, wait for the resin to cool down before discharging. Then concentrate the synthesized double-bond silicon-containing anti-fingerprint acrylic resin by rotary evaporation, slowly pour the concentrated solution into n-hexane for precipitation, repeat precipitation and dissolution several times to obtain a purified product, put it into a vacuum oven at 80℃ for drying, and obtain a double-bond silicon-containing anti-fingerprint acrylic resin.

[0044] Comparative Example 2 (double bond-containing fluorine-containing anti-fingerprint acrylic resin) 20g of butyl acetate was poured into a four-necked round-bottomed flask, nitrogen was continuously introduced, and the system was heated to the specified temperature and reflux occurred; 20g of methyl methacrylate, 35.75g of hydroxyethyl methacrylate and 2g of tert-butyl perbenzoate were mixed and slowly added to the four-necked flask through a constant pressure tetrafluoroethylene funnel for 3h; the mixture was kept warm for 9h after the addition was completed, and 0.5g of tert-butyl perbenzoate was added every 3h during the insulation period, for a total of two additions, and the reaction was completed and the resin was cooled and discharged; 41.7g of 13-fluorooctyl methacrylate was added to the synthesized resin. 0.5g of dibutyltin dilaurate was dropped at 80℃; the synthesized fluorine-containing anti-fingerprint acrylic resin was then concentrated by rotary evaporation, and the concentrate was slowly poured into n-hexane for precipitation. The purified product was obtained by repeated precipitation and dissolution 3 times, and then placed in a vacuum oven at 80℃ for drying. Add 20g of fluorine-containing anti-fingerprint acrylic resin and 80g of butyl acetate mixture to a four-necked round-bottom flask, start stirring and heating, the speed is 100rpm, and the temperature is heated to 80℃. Then slowly drop 31g of ethyl isocyanate acrylate solution with a monomer concentration of 15%, and the drop time is 30min. After the drop addition is completed, add 0.5g of dibutyltin dilaurate, keep warm for 9h, and after the reaction is completed, wait for the resin to cool down before discharging. Then concentrate the synthesized double-bond fluorine-containing anti-fingerprint acrylic resin by rotary evaporation, slowly pour the concentrated solution into n-hexane for precipitation, repeat precipitation and dissolution several times to obtain a purified product, put it into a vacuum oven at 80℃ for drying, and obtain a double-bond fluorine-containing anti-fingerprint acrylic resin.

[0045] Example 1 (double bond-containing, fluorine-containing, and silicon-containing anti-fingerprint acrylic resin, 40 mol% silicon) 20g of butyl acetate was poured into a four-necked round-bottomed flask, nitrogen was continuously introduced, and the system was heated to the specified temperature and reflux occurred; 20g of methyl methacrylate, 35.75g of hydroxyethyl methacrylate and 2g of tert-butyl perbenzoate were mixed and slowly added to the four-necked flask through a constant pressure tetrafluoroethylene funnel for 3h; the mixture was kept warm for 9h after the addition was completed, and 0.5g of tert-butyl perbenzoate was added every 3h during the insulation period, for a total of two additions, and the reaction was completed and the resin was cooled and discharged; 25.02g of 13-fluorooctyl methacrylate and 9.48g of methacrylate silicone were added to the synthesized resin. 0.5g of dibutyltin dilaurate was added at 80℃; the synthesized fluorine-containing and silicon-containing anti-fingerprint acrylic resin was then concentrated by rotary evaporation, and the concentrate was slowly poured into n-hexane for precipitation. The purified product was obtained by repeated precipitation and dissolution 3 times, and then placed in a vacuum oven at 80℃ for drying. Add 20g of fluorine-containing silicon-containing anti-fingerprint acrylic resin and 80g of butyl acetate mixture to a four-necked round-bottom flask, start stirring and heating, the speed is 100rpm, and the temperature is heated to 80℃. Then slowly drop 31g of isocyanate ethyl acrylate solution with a monomer concentration of 15%, and the dropping time is 30min. After the dropwise addition is completed, add 0.5g of dibutyltin dilaurate, keep warm for 9h, and after the reaction is completed, wait for the resin to cool down before discharging. Then concentrate the synthesized double-bond-containing fluorine-containing silicon-containing anti-fingerprint acrylic resin by rotary evaporation, slowly pour the concentrated solution into n-hexane for precipitation, repeat the precipitation and dissolution several times to obtain the purified product, put it into a vacuum oven at 80℃ for drying, and obtain the double-bond-containing fluorine-containing silicon-containing anti-fingerprint acrylic resin (40mol% silicon).

[0046] Example 2 (double bond-containing, fluorine-containing, and silicon-containing anti-fingerprint acrylic resin, 60 mol% silicon) 20g of butyl acetate was poured into a four-necked round-bottomed flask, nitrogen was continuously introduced, and the system was heated to the specified temperature and reflux occurred; 20g of methyl methacrylate, 35.75g of hydroxyethyl methacrylate and 2g of tert-butyl perbenzoate were mixed and slowly added to the four-necked flask through a constant pressure tetrafluoroethylene funnel for 3h; the mixture was kept warm for 9h after the addition was completed, and 0.5g of tert-butyl perbenzoate was added every 3h during the insulation period, for a total of two additions, and the reaction was completed and the resin was cooled and discharged; 16.68g of 13-fluorooctyl methacrylate and 14.22g of methacrylate silicone were added to the synthesized resin. 0.5g of dibutyltin dilaurate was dropped at 80℃; the synthesized fluorine-containing and silicon-containing anti-fingerprint acrylic resin was then concentrated by rotary evaporation, and the concentrate was slowly poured into n-hexane for precipitation. The precipitation and dissolution were repeated 3 times to obtain the purified product, which was placed in a vacuum oven at 80℃ for drying. Add 20g of fluorine-containing silicon-containing anti-fingerprint acrylic resin and 80g of butyl acetate mixture to a four-necked round-bottom flask, start stirring and heating, the speed is 100rpm, and the temperature is heated to 80℃. Then slowly drop 31g of isocyanate ethyl acrylate solution with a monomer concentration of 15%, and the dropping time is 30min. After the dropwise addition is completed, add 0.5g of dibutyltin dilaurate, keep warm for 9h, and after the reaction is completed, wait for the resin to cool down before discharging. Then concentrate the synthesized double-bond-containing fluorine-containing silicon-containing anti-fingerprint acrylic resin by rotary evaporation, slowly pour the concentrated solution into n-hexane for precipitation, repeat precipitation and dissolution several times to obtain a purified product, put it into a vacuum oven at 80℃ for drying, and obtain a double-bond-containing fluorine-containing silicon-containing anti-fingerprint acrylic resin (60mol% silicon).

[0047] Example 3 (double bond-containing, fluorine-containing, and silicon-containing anti-fingerprint acrylic resin, 80 mol% silicon) 20g of butyl acetate was poured into a four-necked round-bottomed flask, nitrogen was continuously introduced, and the system was heated to the specified temperature and reflux occurred; 20g of methyl methacrylate, 35.75g of hydroxyethyl methacrylate and 2g of tert-butyl perbenzoate were mixed and slowly added to the four-necked flask through a constant pressure tetrafluoroethylene funnel for 3h; the mixture was kept warm for 9h after the addition was completed, and 0.5g of tert-butyl perbenzoate was added every 3h during the insulation period, for a total of two additions, and the reaction was completed and the resin was cooled and discharged; 8.34g of 13-fluorooctyl methacrylate and 18.96g of methacrylate silicone were added to the synthesized resin. 0.5g of dibutyltin dilaurate was dropped at 80℃; the synthesized fluorine-containing and silicon-containing anti-fingerprint acrylic resin was then concentrated by rotary evaporation, and the concentrate was slowly poured into n-hexane for precipitation. The purified product was obtained by repeated precipitation and dissolution 3 times, and then placed in a vacuum oven at 80℃ for drying. Add 20g of fluorine-containing silicon-containing anti-fingerprint acrylic resin and 80g of butyl acetate mixture to a four-necked round-bottom flask, start stirring and heating, the speed is 100rpm, and the temperature is heated to 80℃. Then slowly drop 31g of isocyanate ethyl acrylate solution with a monomer concentration of 15%, and the dropping time is 30min. After the dropwise addition is completed, add 0.5g of dibutyltin dilaurate, keep warm for 9h, and after the reaction is completed, wait for the resin to cool down before discharging. Then concentrate the synthesized double-bond-containing fluorine-containing silicon-containing anti-fingerprint acrylic resin by rotary evaporation, slowly pour the concentrated solution into n-hexane for precipitation, repeat precipitation and dissolution several times to obtain a purified product, put it into a vacuum oven at 80℃ for drying, and obtain a double-bond-containing fluorine-containing silicon-containing anti-fingerprint acrylic resin (80mo1% silicon).

[0048] Coating preparation example: Comparative Example 3 (1) 35 g of trimethylolpropane triacrylate, 25 g of bisphenol A epoxy acrylic resin, 17 g of ethyl acetate, 20 g of butyl acetate and 3 g of 2-hydroxy-2-methyl-1-phenyl-1-propanone were mixed, placed in a beaker and stirred at 180 rpm for 10 min to uniformly mix to obtain a photocurable coating masterbatch.

[0049] (2) 95 g of the photocurable coating mother liquid was taken, and 5 g of the double-bond-containing silicon-containing anti-fingerprint acrylic resin prepared in Comparative Example 1 was added thereto. The mixture was stirred at 180 rpm for 10 min and then placed in a 60° C. oven for 5 min to remove the solvent. After the baking, the mixture was placed in a photocuring machine and cured using a mercury lamp as a light source to obtain a silicon-containing UV-curable anti-fingerprint coating.

[0050] Comparative Example 4 The only difference from Comparative Example 3 is that in step (2), 5 g of the double-bond-containing fluorine-containing anti-fingerprint acrylic resin prepared in Comparative Example 2 is used to replace 5 g of the double-bond-containing silicon-containing anti-fingerprint acrylic resin prepared in Comparative Example 1, and a photocurable coating mother liquor is added. The remaining steps, materials and compositions are the same as those of Comparative Example 3.

[0051] The only difference between Example 4 and Comparative Example 3 is that in step (2), 5 g of the double-bond, fluorine-containing, silicon-containing anti-fingerprint acrylic resin (40 mol% silicon) prepared in Example 1 is used to replace 5 g of the double-bond, silicon-containing anti-fingerprint acrylic resin prepared in Comparative Example 1, and the photocurable coating mother liquor is added. The remaining steps, materials and composition are the same as those of Comparative Example 3.

[0052] The only difference between Example 5 and Comparative Example 3 is that in step (2), 5 g of the double-bond, fluorine-containing, silicon-containing anti-fingerprint acrylic resin (60 mol% silicon) prepared in Example 2 is used to replace 5 g of the double-bond, silicon-containing anti-fingerprint acrylic resin prepared in Comparative Example 1, and the photocurable coating mother liquor is added. The remaining steps, materials and composition are the same as those of Comparative Example 3.

[0053] The only difference between Example 6 and Comparative Example 3 is that in step (2), 5 g of the double-bond, fluorine-containing, silicon-containing anti-fingerprint acrylic resin (80 mol% silicon) prepared in Example 3 is used to replace 5 g of the double-bond, silicon-containing anti-fingerprint acrylic resin prepared in Comparative Example 1, and the photocurable coating mother liquor is added. The remaining steps, materials and composition are the same as those of Comparative Example 3.

[0054] Comparative Example 5 The only difference from Comparative Example 3 is that in step (2), 10 g of double-bond, fluorine-containing, and silicon-containing anti-fingerprint acrylic resin (60 mol% silicon) is added to 95 g of photocurable coating mother liquor, and the remaining steps, materials, and composition are consistent with Comparative Example 3.

[0055] Comparative Example 6 The only difference from Comparative Example 3 is that in step (2), 5 g of fluorine hyperbranched polymer is added to 95 g of photocurable coating mother liquor, and the remaining steps, materials and composition are the same as those of Comparative Example 3.

[0056] Performance Testing The UV-curable anti-fingerprint coatings prepared in each embodiment and the coatings prepared in each comparative example were tested for hardness, adhesion, anti-graffiti, water contact angle and other properties, wherein the hardness test was carried out in accordance with GB / T 6739, and the results were evaluated as follows: the paint film was scratched; the adhesion test was carried out in accordance with GB / T 9286, with a spacing of 1mm; the anti-graffiti test was carried out by writing and wiping with an oil pen on the coating surface. Two points at a certain distance were selected on the coating surface, and then three straight lines were drawn between the two points. Finally, the surface was wiped with a dust-free cloth, and the writing and wiping were repeated until the ink could not be erased, and the number of times was recorded. The water contact angle test was obtained by testing with a DSA 10-MK2 droplet analyzer (Kruss, Germany), and the droplet volume used in the experiment was 5μL. The transmittance was determined in accordance with GB / T2410-2008; the test environment temperature was 25°C; the relative humidity was 70%RH.

[0057] Table 1: Performance test results of each embodiment and each comparative example product: From the comparison of the data in the above table, we can see that: Comparative Example 4 uses a double-bond-containing fluorine-containing anti-fingerprint acrylic resin to replace the double-bond-containing silicon-containing anti-fingerprint acrylic resin in Comparative Example 3. Since the harder structure such as silicone in the system is replaced by a softer structure such as fluorine, the hardness of the coating is reduced, but the anti-graffiti property of the coating is improved and the water contact angle is increased, indicating that the fluorine-containing structure of the coating with the same material mass is better resistant to dirt than the silicon-containing structure.

[0058] Examples 4-6 use double-bond, fluorine-containing, and silicon-containing anti-fingerprint acrylic resins with different proportions of silicon components to replace the double-bond, silicon-containing anti-fingerprint acrylic resins in Comparative Example 3, and dope the organic silicon structure with the fluorine structure in the system. Compared with the coating containing only silicon structure, the hardness is reduced, but the anti-fouling property of the coating first increases with the increase of the fluorine ratio, and then decreases. Among them, the double-bond, fluorine-containing, and silicon-containing anti-fingerprint acrylic resin (60 mol% silicon) prepared in Example 2 has the best effect. The reason may be that when the two are doped, the interface layer has both the excellent lubricity of siloxane and the excellent hydrophobic and oleophobic properties of the fluorine segment, which plays a synergistic effect until the best effect. With the excess of fluorine segments, the microstructure and dynamic behavior of the anti-fingerprint acrylic resin are affected, especially its unique creep properties. The fluorine segment limits the free rotation and displacement between molecules due to its high rigidity and strong hydrophobicity. When the fluorine content gradually increases, these special segments begin to occupy a larger proportion in the molecular structure, enhancing the local rigidity and reducing the flexibility and creep ability of the silicon segment. Similar to mixing hard wires into a soft rubber belt, the originally smooth deformation process is hindered, resulting in a decrease in the dynamic creep recovery performance of the entire material system. This will be directly reflected in the number of graffiti resistance. Faced with repeated smearing or wiping external loads, the resin coating's restoring force is weakened, which is manifested as impaired durability, that is, a decrease in the number of graffiti resistance.

[0059] In comparative example 5, the amount of double-bond, fluorine-containing, and silicon-containing anti-fingerprint acrylic resin (60 mol% silicon) added was increased from 5% to 10%, but from the test results, the anti-graffiti property and water contact angle of the coating were not greatly improved. This is because when the silanol and fluoroalcohol are grafted to a certain critical value, the siloxane segments and fluorine segments on the surface of the coating have reached a fully enriched state, and their distribution density is close to the saturation threshold. It is difficult for the newly added segments to find enough free space to embed. In this case, even if the doping ratio of silanol and fluoroalcohol is further increased, the contribution to the comprehensive performance of the coating surface is negligible. However, since the amount of anti-fingerprint acrylic resin added is doubled, the cost of the coating will increase.

[0060] In Comparative Example 6, a fluorine-hyperbranched polymer is used to replace the homemade functional acrylic resin of the same mass. From the test results, it can be seen that its transmittance is significantly reduced. This is because the compatibility of the fluorine-hyperbranched polymer is lower than that of the homemade functional acrylic resin, and it will be unevenly distributed in the resin matrix and form aggregates, forming an optically heterogeneous region between the two phases, thereby reducing the transmittance.

[0061] The raw materials and equipment used in the present invention, unless otherwise specified, are all commonly used raw materials and equipment in the art; the methods used in the present invention, unless otherwise specified, are all conventional methods in the art.

[0062] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A UV-curable anti-fingerprint coating, characterized in that The invention comprises the following raw materials in parts by weight: 90-99 parts of photocuring coating masterbatch; 1-10 parts of double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin, whose synthetic monomers include: 18-23 parts of methyl methacrylate, 25-30 parts of hydroxyethyl methacrylate, 15-35 parts of anti-fingerprint functional monomer, and 28-35 parts of ethyl isocyanate acrylate; The anti-fingerprint functional monomers are silicone methacrylate and tridecafluorooctyl methacrylate.

2. The UV-curable anti-fingerprint coating according to claim 1, characterized in that: The anti-fingerprint functional monomer contains 40-80 mol% of methacrylate silicone.

3. The UV-curable anti-fingerprint coating according to claim 1 or 2, characterized in that: The raw materials of the double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin include: 18-23 parts of methyl methacrylate, 25-30 parts of hydroxyethyl methacrylate, 15-35 parts of anti-fingerprint functional monomer, 28-35 parts of isocyanate ethyl acrylate, 2-5 parts of initiator, 0.5-1 part of catalyst and solvent.

4. The UV-curable anti-fingerprint coating according to claim 3, characterized in that: The solvent is selected from ethyl acetate and butyl acetate; The initiator is selected from tert-butyl perbenzoate, di-tert-amyl peroxide and di-tert-butyl peroxide; The catalyst is selected from dibutyltin dilaurate and dibutyltin sulfide.

5. The UV-curable anti-fingerprint coating according to claim 1, characterized in that: The raw materials of the photocurable coating mother solution include: 40-60 parts of trimethylolpropane triacrylate, 20-30 parts of epoxy resin, 15-27 parts of solvent and 1-5 parts of photoinitiator.

6. The UV-curable anti-fingerprint coating according to claim 5, characterized in that: The epoxy resin is selected from bisphenol A epoxy acrylic resin and bisphenol epoxy acrylate; The solvent is selected from ethyl acetate and butyl acetate; The photoinitiator is selected from 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-(4-methylthiophenyl)-2-morpholine-1-propanone and 2-hydroxy-2-methyl-1-phenyl-1-propanone.

7. A method for preparing the UV-curable anti-fingerprint coating according to any one of claims 1 to 6, characterized in that include: 1) Preparation of photocurable coating mother solution: bisphenol A epoxy acrylic resin, trimethylolpropane triacrylate, photoinitiator and solvent are uniformly mixed to obtain photocurable coating mother solution; 2) Preparation of double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin: add methyl methacrylate, hydroxyethyl methacrylate and initiator to the solvent and mix well, heat to react, add anti-fingerprint functional monomer and catalyst to continue the reaction, concentrate, add the concentrated solution to the purified solution for precipitation, and dry; mix the obtained product with the solvent, heat, add isocyanate ethyl acrylate dropwise, add the catalyst to react, concentrate, add the concentrated solution to the purified solution for precipitation, and dry.

8. The preparation method according to claim 7, characterized in that: In step 2): The concentration and precipitation are repeated multiple times; The purified liquid is selected from n-hexane, n-pentane, n-heptane and n-octane.

9. Use of the UV-curable anti-fingerprint coating according to any one of claims 1 to 6 or the UV-curable anti-fingerprint coating obtained by the preparation method according to claim 7 or 8 in the preparation of UV-curable anti-fingerprint coatings, characterized in that include: The double-bond, fluorine-containing and silicon-containing anti-fingerprint acrylic resin is mixed with a photocurable coating mother solution, coated on the surface of a substrate, dried, and then cured by ultraviolet light to obtain an ultraviolet-cured anti-fingerprint coating.

10. The use according to claim 9, characterized in that: The drying time is 50-70° C. and the time is 1-5 min.

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