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CN-122011468-A - Scratch-resistant PET protective film and preparation method thereof

CN122011468ACN 122011468 ACN122011468 ACN 122011468ACN-122011468-A

Abstract

The application relates to the technical field of high-molecular functional film materials, and particularly discloses a scratch-resistant PET (polyethylene terephthalate) protective film and a preparation method thereof. The scratch-resistant PET protective film comprises a PET base film layer, a bottom layer and a surface layer, wherein the bottom layer is obtained by coating a bottom layer coating liquid on the PET base film layer, the surface layer is obtained by coating a surface layer coating liquid on the bottom layer, the bottom layer coating liquid comprises the following raw materials in parts by weight, namely, modified polyurethane acrylic ester, a silane coupling agent, a first photoinitiator and ethyl acetate, and the surface layer coating liquid comprises the following raw materials in parts by weight, namely, aliphatic polyurethane acrylic ester, glycidyl methacrylate, modified nano silicon dioxide, a second photoinitiator, a leveling agent and ethyl acetate. The PET protective film can effectively enhance the adhesive force and the scratch resistance of the PET protective film.

Inventors

  • WANG ZHUOLING
  • YANG YUEHONG
  • HUANG ZHIWEI
  • WANG PEIQING

Assignees

  • 佛山市奥川顺新材料实业有限公司

Dates

Publication Date
20260512
Application Date
20260313

Claims (10)

  1. 1. The scratch-resistant PET protective film is characterized by comprising a PET base film layer, a bottom layer and a surface layer, wherein the bottom layer is obtained by coating a bottom layer coating liquid on the PET base film layer, and the surface layer is obtained by coating a surface layer coating liquid on the bottom layer; The bottom coating liquid comprises the following raw materials, by weight, 35-45 parts of modified polyurethane acrylic ester, 3-5 parts of a silane coupling agent, 1-3 parts of a first photoinitiator and 40-50 parts of ethyl acetate; the surface layer coating liquid comprises, by weight, 40-50 parts of aliphatic polyurethane acrylic ester, 6-10 parts of glycidyl methacrylate, 4-6 parts of modified nano silicon dioxide, 1-3 parts of a second photoinitiator, 1-2 parts of a leveling agent and 45-55 parts of ethyl acetate.
  2. 2. The scratch-resistant PET protective film of claim 1 wherein the modified urethane acrylate is prepared by a process comprising: mixing diisocyanate, a catalyst, a diluent and a polymerization inhibitor, stirring uniformly, heating, adding polycaprolactone triol, stirring uniformly, heating to react to obtain polyurethane prepolymer, cooling, adding 6-hydroxycaproic acid 2-acryloyloxyethyl ester, stirring uniformly, heating to react to obtain polyurethane acrylate prepolymer, cooling, adding saturated fatty alcohol, heating to react, and obtaining modified polyurethane acrylate after the reaction is finished.
  3. 3. The scratch-resistant PET protective film according to claim 2, wherein the molar ratio of polycaprolactone triol, diisocyanate, 2-acryloyloxyethyl 6-hydroxycaproate and saturated fatty alcohol is 1 (2.6-3.2): 1.5-2): 1.2-1.6.
  4. 4. A scratch-resistant PET protective film as in claim 2 wherein said saturated fatty alcohol comprises one or more of lauryl alcohol, cetostearyl alcohol, stearyl alcohol.
  5. 5. The scratch-resistant PET protective film according to claim 1, wherein the preparation method of the modified nano-silica comprises the following steps: Mixing nano silicon dioxide with a dispersion solvent, fully stirring and heating, adding vinyl silane, carrying out heat preservation reaction, filtering, washing and drying after the reaction is completed, and obtaining the modified nano silicon dioxide.
  6. 6. The scratch-resistant PET protective film according to claim 5, wherein the mass ratio of the nano silicon dioxide to the vinyl silane is 1 (0.1-0.2).
  7. 7. The scratch-resistant PET protective film of claim 1 wherein the leveling agent comprises one or more of BYK-3481, BYK-381, and BYK-333.
  8. 8. The scratch-resistant PET protective film according to claim 1, wherein the first photoinitiator comprises one or more of alpha-hydroxy ketones, acetophenones and derivatives thereof, and acyl phosphine oxides, and the second photoinitiator comprises one or more of alpha-hydroxy ketones, acetophenones and derivatives thereof, and acyl phosphine oxides.
  9. 9. A process for the preparation of a scratch-resistant PET protective film according to any one of claims 1 to 8, characterized in that it comprises the following steps: S1, stirring and mixing modified polyurethane acrylic ester, a silane coupling agent, a first photoinitiator and ethyl acetate according to parts by weight under a light-shielding condition, and storing the mixture in a light-shielding manner after the mixing is completed to obtain a bottom coating liquid; s2, carrying out corona treatment on the cleaned PET base film layer; S3, coating the bottom coating liquid on the PET base film layer, and forming a solid bottom layer after preliminary curing; S4, coating the surface layer coating liquid on the bottom layer, and forming the surface layer after gradient curing to obtain the scratch-resistant PET protective film.
  10. 10. The method for producing a scratch-resistant PET protective film according to claim 9, wherein the PET base film layer has a thickness of 50 μm to 188 μm, the base layer has a thickness of 1 μm to 5 μm, and the top layer has a thickness of 2 μm to 8 μm.

Description

Scratch-resistant PET protective film and preparation method thereof Technical Field The invention relates to the technical field of high-molecular functional film materials, in particular to a scratch-resistant PET protective film and a preparation method thereof. Background PET protective films are widely used as surface protective materials, such as off-screen protection of high-end electronics, precision instrument panels, automotive interior surfaces, and temporary protection of architectural glass, due to their excellent transparency, mechanical strength, dimensional stability, and cost advantages. However, the conventional PET film has limited surface hardness (pencil hardness is usually less than or equal to 2H) and scratch resistance, is easily scratched by hard objects (such as keys and grits) or cleaning cloth during use and transportation, and leaves permanent scratches, which not only affect the appearance beauty, but also seriously reduce the display definition or optical performance of the protected product below. In order to solve the problem of insufficient surface hardness of the traditional PET film, the prior art generally coats a hard coating on the PET base film, and improves the surface scratch resistance of the PET protective film by means of the hardness characteristic of the hard coating. However, because the adhesion between the hard coating and the PET substrate is poor, cracking or peeling is likely to occur after bending or temperature difference change, and simply increasing the hardness of the coating tends to result in increased brittleness and decreased flexibility. Disclosure of Invention The application provides a scratch-resistant PET protective film and a preparation method thereof in order to enhance the adhesive force and scratch-resistant performance of the PET protective film. In a first aspect, the application provides a scratch-resistant PET protective film, which adopts the following technical scheme: The scratch-resistant PET protective film comprises a PET base film layer, a bottom layer and a surface layer, wherein the bottom layer is obtained by coating a bottom layer coating liquid on the PET base film layer, and the surface layer is obtained by coating a surface layer coating liquid on the bottom layer; The bottom coating liquid comprises the following raw materials, by weight, 35-45 parts of modified polyurethane acrylic ester, 3-5 parts of a silane coupling agent, 1-3 parts of a first photoinitiator and 40-50 parts of ethyl acetate; the surface layer coating liquid comprises, by weight, 40-50 parts of aliphatic polyurethane acrylic ester, 6-10 parts of glycidyl methacrylate, 4-6 parts of modified nano silicon dioxide, 1-3 parts of a second photoinitiator, 1-2 parts of a leveling agent and 45-55 parts of ethyl acetate. By adopting the technical scheme, the modified polyurethane acrylic ester in the bottom coating liquid has good flexibility and reactivity, and the silane coupling agent contains groups capable of reacting with inorganic materials and organic materials. One end of the silane coupling agent can be chemically reacted with the modified polyurethane acrylic ester to form chemical bond connection, and the other end of the silane coupling agent can be reacted with hydroxyl groups and other groups on the surface of the PET base film layer, so that the adhesive force between the bottom layer and the PET base film layer is enhanced, and the problems that the adhesive force between the traditional PET film hard coating and the PET base material is poor, and cracks and flaking are easy to occur after bending or temperature difference change are solved. In the surface layer coating liquid, glycidyl methacrylate contains epoxy groups, has higher reactivity, can react with active groups of aliphatic polyurethane acrylate to form a crosslinked structure, and improves the hardness and strength of the coating. Meanwhile, the nano silicon dioxide surface is modified, has good dispersibility and reactivity, can be uniformly dispersed in resin, has firm interface combination, and has physical or chemical action with polyurethane acrylic ester and glycidyl methacrylate, so that the hardness and scratch resistance of the coating are further enhanced. The PET protective film adopts a structure with the bottom layer strongly adhered and the surface layer reinforced by nano particles, can effectively resist the scraping of daily sharp objects, and is suitable for scenes requiring high surface durability. Preferably, the modified urethane acrylate is prepared by the following preparation method: mixing diisocyanate, a catalyst, a diluent and a polymerization inhibitor, stirring uniformly, heating, adding polycaprolactone triol, stirring uniformly, heating to react to obtain polyurethane prepolymer, cooling, adding 6-hydroxycaproic acid 2-acryloyloxyethyl ester, stirring uniformly, heating to react to obtain polyurethane acrylate prepolymer, cooling, adding saturated