CN-122011467-A - Anti-aging PET protective film and preparation method thereof

Abstract

The application relates to the technical field of functional polymer films, and particularly discloses an aging-resistant PET (polyethylene terephthalate) protective film and a preparation method thereof. The anti-aging PET protective film comprises a PET base film layer and a weather-resistant coating, wherein the weather-resistant coating is obtained by coating a coating liquid on the surface of the PET base film layer, the PET base film layer comprises the following raw materials in parts by weight, namely, a first PET resin, an anti-aging PET master batch, the raw materials for preparing the anti-aging PET master batch comprise a second PET resin, a shielding agent, an ultraviolet absorber, a stabilizer and an antioxidant, the mass ratio of the second PET resin, the shielding agent, the ultraviolet absorber, the stabilizer and the antioxidant is (55-65): 2-4): 0.7-1): 1-2: (0.1-0.2, and the coating liquid comprises the following raw materials in parts by weight, namely, a fluorosilicone modified acrylic resin, a modified filler, a composite cross-linking agent, a leveling agent and a solvent. The application can realize the lasting and stable ageing 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 anti-aging PET protective film is characterized by comprising a PET base film layer and a weather-resistant coating, wherein the weather-resistant coating is obtained by coating the surface of the PET base film layer with coating liquid; the PET base film layer comprises the following raw materials, by weight, 70-80 parts of first PET resin and 20-30 parts of ageing-resistant PET master batch; The preparation raw materials of the aging-resistant PET master batch comprise (by mass) a second PET resin, a shielding agent, an ultraviolet absorber, a stabilizer and an antioxidant, wherein the mass ratio of the second PET resin to the shielding agent to the ultraviolet absorber to the stabilizer to the antioxidant is (55-65): 2-4): 0.7-1): 1-2: (0.1-0.2); the coating liquid comprises 40-50 parts of fluorosilicone modified acrylic resin, 3-5 parts of modified filler, 4-6 parts of composite cross-linking agent, 1-2 parts of flatting agent and 45-55 parts of solvent.
2. 2. The anti-aging PET protective film according to claim 1, wherein the composite cross-linking agent comprises diisocyanate and etherified melamine formaldehyde resin in a mass ratio of 1 (0.3-0.6).
3. 3. The anti-aging PET protective film according to claim 1, wherein the etherified melamine formaldehyde resin comprises one or two of methylated hexamethylol melamine resin and isobutylated melamine formaldehyde resin, and the diisocyanate comprises one or more of toluene diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate.
4. 4. The aging-resistant PET protective film according to claim 1, wherein the preparation method of the modified filler comprises the following steps: (1) Dispersing nano filler in water, adding long-chain alkyl ammonium salt, heating for reaction, filtering, collecting precipitate after the reaction is completed, washing, and drying to obtain intercalation modified filler, wherein the mass ratio of the nano filler to the long-chain alkyl ammonium salt is (0.6-0.8); (2) Adding absolute ethyl alcohol and mercaptosilane into the intercalation modified filler, heating and stirring, filtering to remove filtrate, washing and drying to obtain the surface modified filler, wherein the mass ratio of the intercalation modified filler to the mercaptosilane is (2-4) (4-6); (3) And adding absolute ethyl alcohol, cardanol and a photoinitiator into the surface modified filler, stirring under ultraviolet irradiation, filtering to remove filtrate, washing and drying to obtain the modified filler, wherein the mass ratio of the surface modified filler to the cardanol to the photoinitiator is (5-6) to (2-3) to (0.3-0.5).
5. 5. The anti-aging PET protective film according to claim 4, wherein the nano filler comprises one or two of nano mica powder and graphene nano sheets.
6. 6. The anti-aging PET protective film according to claim 1, wherein the ultraviolet absorber comprises one or two of benzotriazole ultraviolet absorber and triazine ultraviolet absorber.
7. 7. An anti-aging PET protective film according to claim 1, wherein the stabilizer is a hindered amine light stabilizer.
8. 8. The anti-aging PET protective film according to claim 1, wherein the shielding agent comprises one or two of nano cerium oxide and zinc oxide, and the antioxidant comprises one or more of antioxidant 1010, antioxidant 1076 and antioxidant 168.
9. 9. The anti-aging PET protective film according to claim 1, wherein the leveling agent comprises one or more of BYK-3481, BYK-381, and BYK-333.
10. 10. A method for producing an aging-resistant PET protective film according to any one of claims 1 to 9, characterized by comprising the steps of: S1, fully mixing a second PET resin with a shielding agent, an ultraviolet absorber, a stabilizer and an antioxidant, extruding and granulating to obtain an aging-resistant PET master batch, mixing the aging-resistant PET master batch with a first PET resin, and drying, melt-extruding, sheet casting, longitudinal stretching, transverse stretching, heat setting and rolling to obtain a PET base film layer; s2, stirring and mixing the fluorosilicone modified acrylic resin, the modified filler, the composite cross-linking agent, the leveling agent and the solvent according to parts by weight, and preserving the mixture in a dark place after the mixing is completed to obtain a coating liquid; S3, carrying out corona treatment on the PET base film layer, uniformly coating the coating liquid on the surface of the PET base film layer, and forming a weather-proof coating after gradient curing to obtain the ageing-resistant PET protective film.

Description

Anti-aging PET protective film and preparation method thereof Technical Field The invention relates to the technical field of functional polymer films, in particular to an aging-resistant PET protective film and a preparation method thereof. Background PET protective film is used as a functional polymer film material, and is widely applied to the long-term protection field in the outdoor or strong light environment, such as solar cell panel backboard, outdoor advertising lamp box, building outer wall decorative film, automobile body paste, electronic equipment screen protection and the like by virtue of excellent mechanical strength, transparency and chemical stability. However, under the environment stress of ultraviolet rays, high temperature, oxygen, moisture and the like, the common PET material is easy to undergo photooxidation degradation and thermo-oxidative aging of molecular chains, so that the material has the problems of yellowing, embrittlement, obvious reduction of mechanical properties such as tensile strength, elongation at break and the like, surface chalking and the like. In order to improve the ageing resistance of PET materials, the prior art generally adopts a method of adding an ageing resistance auxiliary agent. For example, by incorporating small molecule aids such as ultraviolet absorbers, antioxidants, etc. into PET substrates, photooxidation and thermo-oxidative aging processes are inhibited, thereby extending the useful life of the material. However, due to the small molecular weight, the aging-resistant auxiliary agents are easy to migrate, volatilize or precipitate during film processing and long-term use, so that the stabilizing effect is rapidly attenuated with time, long-term protection cannot be realized, and the precipitated auxiliary agents can pollute the contacted substrate or the surrounding environment. Disclosure of Invention The application provides an aging-resistant PET protective film and a preparation method thereof in order to realize lasting and stable aging resistance of the PET protective film. In a first aspect, the application provides an aging-resistant PET protective film, which adopts the following technical scheme: The anti-aging PET protective film comprises a PET base film layer and a weather-resistant coating, wherein the weather-resistant coating is obtained by coating the surface of the PET base film layer with coating liquid; the PET base film layer comprises the following raw materials, by weight, 70-80 parts of first PET resin and 20-30 parts of ageing-resistant PET master batch; The preparation raw materials of the aging-resistant PET master batch comprise (by mass) a second PET resin, a shielding agent, an ultraviolet absorber, a stabilizer and an antioxidant, wherein the mass ratio of the second PET resin to the shielding agent to the ultraviolet absorber to the stabilizer to the antioxidant is (55-65): 2-4): 0.7-1): 1-2: (0.1-0.2); the coating liquid comprises 40-50 parts of fluorosilicone modified acrylic resin, 3-5 parts of modified filler, 4-6 parts of composite cross-linking agent, 1-2 parts of flatting agent and 45-55 parts of solvent. By adopting the technical scheme, the anti-aging PET master batch is added into the PET base film layer, and the photo-oxidation and thermo-oxidative aging processes of the PET material can be inhibited by the shielding agent, the ultraviolet absorber, the stabilizer and the antioxidant contained in the master batch, so that the anti-aging capability of the PET base film layer is improved. The coating liquid takes the fluorosilicone modified acrylic resin as a film forming material, has extremely strong UV resistance and chemical stability, can effectively improve the ageing property of the coating, avoids hot adhesion and cold brittleness of the coating, improves the weather resistance, and simultaneously ensures that the coating has better mechanical property. The fluorine-silicon modified acrylic resin molecular chain contains Si-O bond and C-F bond, has very high bond energy, and the C-F bond can form shielding protection on the main chain of C-C, so the stability is good. The filler in the coating liquid is uniformly dispersed in a resin system after modification treatment, and is tightly combined with a resin molecular chain under the action of a composite cross-linking agent to form a labyrinth effect in the coating, so that the permeation path of ultraviolet rays, oxygen and water vapor is greatly prolonged, and the ageing resistance of the coating is further improved. In addition, the composite cross-linking agent reacts with carboxyl and hydroxyl in the resin molecules to change the linear molecular chains into a molecular network structure, and meanwhile, the composite cross-linking agent is combined with the gradient curing process, so that the concentration of internal stress of the coating caused by the over-fast curing speed can be avoided, the generation of microcracks is reduced, the cros