Acrylate adhesive film with high weather resistance as well as preparation method and application thereof

Abstract

The invention relates to the technical field of adhesive films, in particular to a high-weather-resistance acrylate adhesive film which comprises acrylate resin A, a photoinitiator B, a cross-linking agent C and a coupling agent D, and the glass transition temperature Tg of the high-weatherability acrylate adhesive film is-50 DEG C to-30 DEG C. The acrylate adhesive film provided by the invention has high stripping force to a base material and meets the strict 105 DEG C amp; therefore, the liquid crystal display can be applied to the field of vehicle-mounted displays.

Description

Technical Field

[0001] The present invention relates to the technical field of highly weather-resistant acrylic films, and in particular to a highly weather-resistant acrylic film, a preparation method thereof, and applications thereof. Background Art

[0002] With the rapid development of intelligent vehicles, the automotive touch display industry chain is actively developing. Car cockpits are evolving from "smart cockpits" to "smart passenger cabins," with designs increasingly centered around the interaction between people and vehicles. In-vehicle displays are trending toward larger, multi-screen, and multi-format displays. Touch is redefining the human-machine interaction experience in cars.

[0003] Currently, automotive OCAs on the market are primarily synthesized using a solution process. However, this traditional solution process struggles to produce high molecular weight and high-thickness products. The coating process also requires the use of large amounts of solvents, which is not in compliance with environmental regulations. Some automotive OCA products require UV post-curing during use, reducing production efficiency. The use of low-pressure mercury lamps in UV curing can also lead to mercury pollution.

[0004] Patent CN119662144A uses isooctyl acrylate and acrylamide monomers to increase the overall storage modulus of the optical film. However, the isooctyl acrylate monomer has numerous side chains, making it difficult to increase the storage modulus. The low proportion of acrylamide monomer added results in insufficient film rigidity and high-temperature resistance. The use of acrylamide monomer also resulted in reddening of the polarizer after high-temperature reliability testing.

[0005] Patent CN117820976A uses oligomeric silicone to modify acrylic prepolymers, synthesizing oligomers that combine the advantages of silicone and acrylic resins through bulk polymerization to produce high-performance automotive optical adhesives. However, silicone oligomers have poor compatibility with adhesives, and the addition of oligomers reduces the cohesive properties of the adhesive film, resulting in decreased heat resistance.

[0006] With the development of automotive optical adhesives, higher performance requirements are placed on products. Acid-free colloid design is required to ensure that no acidic substances are released during the curing process and under outdoor use conditions, effectively preventing corrosion of electronic components. Excellent adhesion and step-filling capabilities are required to form strong bonds between different materials (such as glass, plastic and metal). Automotive-level reliability tests are required, such as high temperature of 105°C for 1000 hours, 85°C and 85% RH for 1000 hours, etc.

[0007] In response to the shortcomings of the existing technology, the present invention provides a highly weather-resistant acrylic film, which meets green environmental protection requirements during the production process, exhibits high cohesive performance, good high-temperature exhaust performance, high adhesion to the substrate, meets strict durability tests, and meets the development needs of vehicle-mounted displays. Summary of the Invention

[0008] In view of the above-mentioned shortcomings of the prior art, the present invention provides a highly weather-resistant acrylic film and a preparation method and application thereof, which can effectively solve the above-mentioned problems of the prior art.

[0009] Technical Solution

[0010] To achieve the above objectives, the present invention is implemented through the following technical solutions: The present invention provides a highly weather-resistant acrylic film, which comprises an acrylic resin A, a photoinitiator B, a crosslinking agent C, and a coupling agent D; The glass transition temperature Tg of the highly weather-resistant acrylic film is -50°C to -30°C; The acrylic resin A has a solid content of 7-25%, a weight average molecular weight Mw of 800,000-1.2 million, a molecular weight distribution PDI of 1-3, and a viscosity of 1500-5000 cps.

[0011] Furthermore, it includes 100 parts of acrylate resin A, 0.01-1 part of photoinitiator B, 0.01-1 part of crosslinking agent C, and 0.01-1 part of coupling agent D, in parts by weight.

[0012] Furthermore, the acrylic resin A comprises, by weight, 30-75 parts of an acrylic acid ester monomer having 2-8 carbon atoms, 3-35 parts of a hydroxyl-containing acrylic acid ester monomer, 5-30 parts of a cyclic acrylic acid ester monomer, 0.01-0.1 parts of a chain transfer agent, and 0.01-1 parts of a polymerizable photoinitiator; The acrylate monomer with 2-8 carbon atoms is at least one or more of butyl acrylate, isobutyl acrylate, n-hexyl acrylate, n-octyl acrylate, and isooctyl acrylate. These monomers have a low Tg, which can increase the peel strength from the substrate. The acrylate monomer with 2-8 carbon atoms preferably contains a linear acrylate monomer, preferably at least one of butyl acrylate and n-octyl acrylate. The addition of a short linear monomer can increase the overall storage modulus of the film. The proportion of the acrylate monomer with 2-8 carbon atoms relative to the total mass of the acrylic resin A is preferably 30%-75%, more preferably 40-60%.

[0013] The hydroxyl-containing acrylate monomer is at least one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate. Considering the cohesive properties of the film, the hydroxyl-containing acrylate monomer is more preferably at least one of hydroxyethyl acrylate and hydroxybutyl acrylate. The proportion of the hydroxyl-containing acrylate monomer is preferably 3%-35% (relative to the total mass of the high molecular weight acrylate resin A), more preferably 20%-35%. During high-temperature and high-humidity testing, the film must exhibit good hygroscopic properties, so the addition of a hydrophilic hydroxyl monomer improves this performance. The film must also exhibit good air-desorption properties. Excessive hygroscopicity can lead to decreased air-desorption properties and the formation of bubbles after exposure to high temperatures and humidity. Hydroxyethyl acrylate monomer has a relatively high glass transition temperature, so controlling the addition ratio can improve the release strength from the substrate. However, adding too much hydroxyethyl acrylate can significantly increase the storage modulus at room temperature (25°C), reducing the release strength from the substrate. Hydroxybutyl acrylate has a lower glass transition temperature and excellent hydrophilicity. By controlling the ratio of hydroxyethyl acrylate to hydroxybutyl acrylate, properties such as storage modulus and release strength can be balanced.

[0014] The hydroxyl-containing acrylic ester monomer consists of hydroxyethyl acrylate and hydroxybutyl acrylate, and the proportion of hydroxybutyl acrylate is not less than 10 parts relative to the total proportion of the high molecular weight acrylic ester resin A and the total proportion of the acrylic ester resin A monomer.

[0015] The cyclic acrylate monomer is at least one or more of N-vinyl pyrrolidone (NVP), acryloylmorpholine, isobornyl acrylate, cyclohexyl acrylate, 4-tert-butylcyclohexyl acrylate (TBHCA), 3,3,5-trimethylcyclohexyl acrylate, and dicyclopentenyl acrylate. The addition of the cyclic acrylate monomer can increase the gas exhaust performance and storage modulus of the film, meeting strict reliability tests.

[0016] Preferably, the cyclic acrylate monomer is at least one of N-vinyl pyrrolidone, isobornyl acrylate, cyclohexyl acrylate, and 4-tert-butyl cyclohexyl acrylate; More preferably, the cyclic acrylate monomer is at least one of N-vinyl pyrrolidone and 4-tert-butyl cyclohexyl acrylate; the glass transition temperature Tg of the cyclic acrylate monomer is preferably 3°C-150°C, more preferably 10°C-110°C.

[0017] Relative to the total mass of the high molecular weight acrylate resin A, the ratio of the cyclic acrylate monomer may be 5-30%, more preferably 10-20%.

[0018] A chain transfer agent is used in the high molecular weight acrylic resin A to control the reaction process. The chain transfer agent includes any one of n-dodecyl mercaptan, n-octadecyl mercaptan, or pentaerythritol tetrakis(3-mercaptobutyrate), or a combination of at least two thereof. To adjust the weight-average molecular weight of the acrylic resin A, the chain transfer agent content is preferably 0.01-0.1%, more preferably 0.01-0.05%, relative to the total mass of the acrylic resin A.

[0019] The high molecular weight acrylic resin A further comprises a polymeric photoinitiator. The polymeric photoinitiator is at least one of 1-hydroxycyclohexyl phenyl ketone (184 photoinitiator), 2,4,6-trimethylbenzoyldiphenoxyphosphine (TPO photoinitiator), 2-hydroxy-2-methyl-1-phenyl-1-propanone, benzophenone, 4-acryloyloxybenzophenone, and α,α-dimethoxy-α-phenylacetophenone. Relative to the total mass of the acrylate resin A, the ratio of the polymerizable photoinitiator to the photoinitiator B is preferably 0.01-1 part, more preferably 0.05-1 part.

[0020] Furthermore, the acrylic resin A comprises, by weight, 40-60 parts of an acrylic ester monomer having 2-8 carbon atoms, 10-35 parts of a hydroxyl-containing acrylic ester monomer, 10-20 parts of a cyclic acrylic ester monomer, 0.01-0.05 parts of a chain transfer agent, and 0.05-1 parts of a polymerizable photoinitiator.

[0021] Preferably, the acrylic resin A comprises, by weight, 55-60 parts of an acrylic ester monomer having 2-8 carbon atoms, 25-30 parts of a hydroxyl-containing acrylic ester monomer, 15 parts of a cyclic acrylic ester monomer, 0.01-0.05 parts of a chain transfer agent, and 0.05-1 parts of a polymerizable photoinitiator.

[0022] Furthermore, the acrylate resin A is obtained by partial polymerization reaction of a polymerizable photoinitiator under ultraviolet light; The polymerization reaction is partially polymerized under ultraviolet irradiation in an inert gas; preferably, the inert gas is at least one of helium and nitrogen; The wavelength of the ultraviolet irradiation is 300-400 nm; the light intensity of the ultraviolet irradiation is 0.1-10 mW / cm 2 .

[0023] Preferably, the high molecular weight acrylate resin A is prepared by a UV polymerization process, wherein 30-75 parts by weight of an acrylate monomer having 2-8 carbon atoms, 3-35 parts by weight of a hydroxy acrylate monomer, 5-30 parts by weight of a cyclic acrylate monomer, 0.01-0.5 parts by weight of a chain transfer agent, and 0.01-0.5 parts by weight of a polymerization-type photoinitiator are partially polymerized under UV light.

[0024] Preferably, the wavelength of the ultraviolet irradiation is 280-420 nm, preferably 365 nm.

[0025] Preferably, the intensity of the ultraviolet irradiation is 1-20 mW / cm 2 , preferably the light intensity is 0.1-10 mW / cm 2 .

[0026] High molecular weight acrylate resin A undergoes partial polymerization under a certain UV intensity. The solid content reflects the degree of polymerization. The solid content (%) calculation formula is as follows: Solid content (%) = (M1-M2) / M1*100; Wherein, M2 is the mass of acrylate resin A after drying at 150° C. for 2 hours, and M1 is the mass of the initial high molecular weight acrylate resin A. Preferably, the solid content of the acrylate resin A is 7-25%, more preferably 7-20%.

[0027] The weight-average molecular weight (Mw) of the high molecular weight acrylate resin A is preferably 500,000-2,000,000, more preferably 800,000-1,500,000, and even more preferably 800,000-1,200,000. The PDI is preferably 1-3, more preferably 1.1-2, and even more preferably 1.1-1.5. The weight-average molecular weight (Mw) and PDI of the high molecular weight acrylate resin A can be measured using a gel permeation chromatography instrument in tetrahydrofuran at 40°C.

[0028] The viscosity of the high molecular weight acrylate resin A can be measured by a viscometer at room temperature of 25° C. The viscosity of the high molecular weight acrylate resin A at 25° C. is 1500-10000 cps, preferably 1500-5000 cps, and more preferably 1500-3500 cps. The viscosity of the acrylate resin A is measured by using a rotational viscometer.

[0029] Furthermore, the photoinitiator B may be at least one of 1-hydroxycyclohexyl phenyl ketone (184 photoinitiator), 2,4,6-trimethylbenzoyldiphenoxyphosphine (TPO photoinitiator), 2-hydroxy-2-methyl-1-phenyl-1-propanone, benzophenone, 4-acryloyloxybenzophenone, and α, α-dimethoxy-α-phenylacetophenone; Relative to 100 parts by weight of the high molecular weight acrylate resin A, the ratio of the photoinitiator B is preferably 0.1-2 parts, more preferably 0.4-1 part.

[0030] Furthermore, the crosslinking agent C is at least one or more of 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, polyethylene glycol diacrylate, and bifunctional aliphatic polyurethane acrylate; The amount of crosslinking agent C used is generally about 0.01 to 1 part, preferably 0.01 to 0.5 part by weight, relative to 100 parts by weight of high molecular weight acrylate resin A; The coupling agent D is at least one or more of γ-glycidoxypropyltrimethoxysilane and γ-methacryloxypropyltrimethoxysilane. The addition of coupling agent D can enhance adhesion to the glass substrate. The amount of coupling agent D used is typically about 0.01 to 1 part by weight, preferably 0.01 to 0.5 parts by weight, relative to 100 parts by weight of the high molecular weight acrylate resin A.

[0031] A method for preparing a highly weather-resistant acrylic film comprises: mixing a high molecular weight acrylic resin A, a photoinitiator B, a crosslinking agent C, and a coupling agent D, degassing the mixture, coating the mixture on a release film, and UV curing the mixture to obtain the acrylic film.

[0032] The curing includes curing under ultraviolet light, low pressure or high pressure mercury lamp; Preferably, the curing light intensity is 1-50 mW / cm 2 Preferably, the intensity of the ultraviolet irradiation is 1-10mW / cm 2 , the preferred wavelength of the curing light source is 365nm; preferably, the total radiation energy of the curing is 800-10000 mJ, preferably 800-5000mj.

[0033] Preferably, the release film comprises a polyethylene terephthalate release film.

[0034] Application of the above-mentioned highly weather-resistant acrylic film and the highly weather-resistant acrylic film prepared by the above-mentioned preparation method in the field of vehicle-mounted displays.

[0035] Beneficial effects

[0036] Compared with the known public technologies, the technical solution provided by the present invention has the following beneficial effects: (1) The acrylic film prepared by the present invention has high heat resistance, an acid-free formula structure design, and does not use amide-containing monomers in the formula, which alleviates the redness problem of polarizers after high temperature and high humidity, and has high adhesion to the substrate. The traditional solution method for synthesizing automotive OCA uses a large amount of solvent during the synthesis process, which does not meet the requirements of environmental protection regulations. To obtain a film with a thickness of more than 250um by the solution method, a large amount of solvent needs to be dried, which wastes a lot of resources. The UV polymerization process has a narrow molecular weight distribution and high molecular weight, and can produce products with high cohesive performance. The present invention adopts a solvent-free UV light curing process for production, and no harmful solvents are volatilized during the process. The curing process uses a high-efficiency UV LED light source. The curing speed and energy efficiency are both better than those of traditional mercury lamps, meeting the characteristics of green chemical products such as high energy efficiency, non-toxicity, and environmental friendliness.

[0037] (2) The acrylic film prepared by the present invention has a thickness of 150-300 μm, a storage modulus greater than 80 kPa at room temperature (25°C), a peeling force greater than 1300 gf on a steel plate at room temperature for 20 minutes, and a peeling force greater than 600 gf on a steel plate at a high temperature of 110°C. It has good exhaust performance and can pass performance tests such as automotive-grade high temperature (105°C & 1000 h) and high temperature and high humidity (85°C & 85% RH). BRIEF DESCRIPTION OF THE DRAWINGS

[0038] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0039] Figure 1 This is the appearance of Example 1 of the present invention after passing high temperature resistance of 105°C for 1000 hours.

[0040] It can be seen that the film has high cohesive properties, no bubbles on the film surface after high temperature resistance of 105℃&1000h, and good exhaust performance. DETAILED DESCRIPTION

[0041] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0042] The present invention will be further described below with reference to the embodiments.

[0043] (1) The experimental materials used in the examples and comparative examples of the present invention are as follows:

[0044] (1) Raw material manufacturers IOA, n-octyl acrylate (Osaka Organic Chemical); BA, butyl acrylate (Yongzheng Chemical); HBA, hydroxybutyl acrylate (Osaka Organic Chemical); HEA, hydroxyethyl acrylate (Yongzheng Chemical); NVP, N-vinylpyrrolidone (Yongzheng Chemical); IBOA, isobornyl acrylate (Yongzheng Chemical); TBCHA, 4-tert-butylcyclohexyl acrylate (Changxing Chemical); HDDA, 1,6-hexanediol diacrylate (Yongzheng Chemical); KBM-403, γ-glycidyloxypropyltrimethoxysilane (Yongzheng Chemical); NDM, n-dodecyl mercaptan (Aladdin); Photoinitiator 184, 1-hydroxycyclohexylphenyl ketone (IGM); Photoinitiator TPO, 2,4,6-trimethylbenzoyldiphenoxyphosphine (IGM).

[0045] (2) Preparation of acrylate resin A1 The raw materials for preparation include: 55 parts of BA, 10 parts of HEA, 20 parts of HBA, 15 parts of TBCHA, 0.05 parts of 184 initiator, and 0.02 parts of NDM chain transfer agent.

[0046] The preparation method of the acrylic resin A1 comprises: adding BA, HEA, HBA, TBCHA, 184, and NDM into a 500 mL four-necked flask, introducing nitrogen for 20 minutes, stirring evenly, irradiating under a 365 nm wavelength LED ultraviolet lamp for 3 minutes, and then introducing air to inhibit polymerization. The ultraviolet light intensity is 5 mw / cm 2 , the acrylic resin A1 was obtained, having a viscosity of 2100 cps at 25° C. and a solid content of 12%.

[0047] (3) Preparation of acrylate resin A2 The raw materials for the preparation include: 35 parts of IOA, 20 parts of BA, 10 parts of HEA, 20 parts of HBA, 15 parts of TBCHA, 0.05 parts of 184 initiator, and 0.02 parts of NDM chain transfer agent.

[0048] The preparation method of the acrylic resin A2 comprises: adding IOA, BA, HEA, HBA, TBCHA, 184, and NDM into a 500 mL four-necked flask, introducing nitrogen for 20 minutes, stirring evenly, irradiating under a 365 nm wavelength LED ultraviolet lamp for 2 minutes, and then introducing air to inhibit polymerization. The ultraviolet light intensity is 5 mw / cm 2 , the acrylic resin A2 was obtained, having a viscosity of 1500 cps at 25° C. and a solid content of 8%.

[0049] (4) Preparation of acrylic resin A3 The raw materials for the preparation include: 60 parts of BA, 5 parts of HEA, 20 parts of HBA, 5 parts of NVP, 10 parts of TBCHA, 0.05 parts of 184 initiator, and 0.01 parts of NDM chain transfer agent.

[0050] The preparation method of the acrylic resin A3 comprises: adding BA, HEA, HBA, NVP, TBCHA, 184, and NDM into a 500 mL four-necked flask, introducing nitrogen for 20 minutes, stirring evenly, irradiating under a 365 nm wavelength LED ultraviolet lamp for 5 minutes, and then introducing air to inhibit polymerization. The ultraviolet light intensity is 5 mw / cm 2 , the acrylic resin A3 is obtained, having a viscosity of 3000 cps at 25° C. and a solid content of 15%.

[0051] (5) Preparation of acrylate resin A4 The raw materials for preparation include: 70 parts of BA, 5 parts of HEA, 20 parts of HBA, 5 parts of TBCHA, 0.05 parts of 184 initiator, and 0.01 parts of NDM chain transfer agent.

[0052] The preparation method of the acrylic resin A4 comprises: adding BA, HEA, HBA, TBHCA, 184, and NDM into a 500 mL four-necked flask, introducing nitrogen for 20 minutes, stirring evenly, irradiating under a 365 nm wavelength LED ultraviolet lamp for 5 minutes, and then introducing air to inhibit polymerization. The ultraviolet light intensity is 5 mw / cm 2 , the acrylic resin A4 was obtained, having a viscosity of 2000 cps at 25° C. and a solid content of 12%.

[0053] (6) Preparation of acrylate resin A5 The raw materials for the preparation include: 70 parts of BA, 15 parts of HEA, 10 parts of HBA, 5 parts of NVP, 0.05 parts of 184 initiator, and 0.01 parts of NDM chain transfer agent.

[0054] The preparation method of the acrylic resin A5 comprises: adding BA, HEA, HBA, NVP, 184, and NDM into a 500 mL four-necked flask, introducing nitrogen for 20 minutes, stirring evenly, irradiating under a 365 nm wavelength LED ultraviolet lamp for 5 minutes, and then introducing air to inhibit polymerization. The ultraviolet light intensity is 5 mw / cm 2 , the acrylic resin A5 was obtained, having a viscosity of 2300 cps at 25° C. and a solid content of 12%.

[0055] (7) Preparation of acrylate resin A6 The raw materials for preparation include: 60 parts of BA, 5 parts of HEA, 10 parts of HBA, 15 parts of TBCHA, 0.05 parts of 184 initiator, and 0.02 parts of NDM chain transfer agent.

[0056] The preparation method of the acrylic resin A6 comprises: adding BA, HEA, HBA, TBCHA, 184, and NDM into a 500 mL four-necked flask, introducing nitrogen for 20 minutes, stirring evenly, irradiating under a 365 nm wavelength LED ultraviolet lamp for 5 minutes, and then introducing air to inhibit polymerization. The ultraviolet light intensity is 5 mw / cm 2 , the acrylic resin A6 was obtained, having a viscosity of 2300 cps at 25° C. and a solid content of 12%.

[0057] (2) Examples Example 1

[0058] 100 parts of acrylate resin A1, 0.25 parts of photoinitiator 184, 0.25 parts of TPO, 0.1 parts of HDDA, and 0.3 parts of KBM-403 were mixed and coated on a 75 μm heavy release film, and then attached to a 50 μm light release film. LED curing was performed with an LED curing wavelength of 365 nm and a curing light intensity of 5 mW / cm 2 The total curing energy is 2000mj, and an OCA product with a thickness of 250um is obtained.

[0059] The difference between Examples 2-3 and Comparative Examples 1-3 and Example 1 is only the components, as shown in Table 1. The preparation methods of Examples 2-3 and Comparative Examples 1-3 are the same as that of Example 1. The test data are shown in Table 2.

[0060]

[0061] (3) Performance testing ① Transmittance and haze: Using a transmittance and haze meter, the prepared OCA pressure-sensitive adhesive film was cut into strips with a length of 40 mm and a width of 10 mm, and the haze was measured using the transmittance and haze meter.

[0062] ②180° Peel Test: Cut the specimen into 2.5cm wide strips and conduct the test according to the international standard ASTM D3330, "Peel Strength Test Method for Pressure-Sensitive Tapes." The test panel is SUS304 steel. Test Method: Before testing, allow the test specimen to stand at room temperature for 20 minutes. The average adhesion force required to remove the strip from the test panel is recorded, expressed in gf / 25mm.

[0063] ③ High-Temperature 110°C Peel Strength Test: Cut the specimen into 2.5cm wide strips and conduct the test according to the international standard ASTM D3330, "Peel Strength Test Standard for Pressure-Sensitive Tapes." The test panel is SUS304 steel. Test Method: Before testing, place the test specimen in a tensile testing machine at 110°C. After the temperature stabilizes for 20 minutes, record the average adhesion force required to remove the strip from the test panel, expressed in gf / 25mm.

[0064] ④ Storage modulus test: Take the PET release film on both sides of the prepared sample, overlap multiple layers of film, and obtain a sample with a thickness of approximately 0.8-1 mm. Cut it into a disc with a diameter of 20 mm. Use a rotational rheometer to measure the shear modulus at different temperatures. The measurement frequency is 1 Hz, and the measured shear modulus values ​​are recorded in kPa.

[0065] ⑤ Reliability Test: The A4-sized OCA sample prepared above was removed from the light release surface and applied to alkali-free glass. The heavy release surface of the film was then removed and applied to a polarizer. The sample was pre-treated in a 90°C oven for 2 hours, then autoclaved at 50°C and 0.5 MPa for 15 minutes. The sample was then tested in a high-temperature (105°C), high-temperature and high-humidity (85°C and 85% RH), high-temperature and high-humidity (65°C and 90% RH), and thermal shock (-40°C and 85°C). The high-temperature (105°C), high-temperature and high-humidity (85°C and 85% RH), and high-temperature and high-humidity (65°C and 90% RH) tests lasted for 1000 hours, and the thermal shock (-40°C and 85°C) test was repeated for 1000 cycles. After the test, the sample was returned to room temperature (25°C) and evaluated. The heat resistance test was visually evaluated according to the following criteria. The test was considered passed if there was no floating or peeling between the polarizer and the film, and no bubbles were generated. If floating or peeling occurs between the polarizer and the film, or a small or large amount of bubbles are generated, the test will fail.

[0066]

[0067] In Examples 1-3, the transmittance exceeded 92% and the haze was less than 0.5%, demonstrating excellent optical properties. Due to the use of a high proportion of cyclic acrylate monomers and hydroxyl monomers in the primary adhesive, the storage modulus at room temperature (25°C) exceeded 80 kPa, indicating high overall cohesiveness and passing rigorous reliability testing. However, in Comparative Examples 1 and 2, the low proportion of cyclic monomers used resulted in a lower overall modulus and low peel strength at high temperatures. Furthermore, numerous bubbles were easily generated during sample preparation, resulting in failure to pass reliability testing.

[0068] In Comparative Example 3, a larger proportion of cyclic monomers was added, but the proportion of hydroxyl monomers used was less than 20 parts, resulting in a decrease in the storage modulus of the film at room temperature, a decrease in the overall cohesive performance of the film, insufficient hydrophilicity, and a decrease in high temperature and high humidity resistance, making it difficult to pass the reliability test.

[0069] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A highly weather-resistant acrylic film, characterized in that: It includes acrylate resin A, photoinitiator B, crosslinking agent C, coupling agent D; The glass transition temperature Tg of the highly weather-resistant acrylic film is -50°C to -30°C; The acrylic resin A has a solid content of 7-25%, a weight average molecular weight Mw of 800,000-1.2 million, a molecular weight distribution PDI of 1-3, and a viscosity of 1500-5000 cps.

2. The highly weather-resistant acrylic film according to claim 1, characterized in that: In parts by weight, it includes 100 parts of acrylate resin A, 0.01-1 parts of photoinitiator B, 0.01-1 parts of crosslinking agent C, and 0.01-1 parts of coupling agent D.

3. The highly weather-resistant acrylic film according to claim 1, characterized in that: In parts by weight, the acrylic resin A comprises 30-75 parts of an acrylic ester monomer having 2-8 carbon atoms, 3-35 parts of a hydroxyl-containing acrylic ester monomer, 5-30 parts of a cyclic acrylic ester monomer, 0.01-0.1 parts of a chain transfer agent, and 0.01-1 parts of a polymerizable photoinitiator; The acrylic acid ester monomer having 2 to 8 carbon atoms is at least one or more of butyl acrylate, isobutyl acrylate, n-octyl acrylate, and isooctyl acrylate; The hydroxyl-containing acrylate monomer is at least one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxybutyl acrylate; The cyclic acrylate monomer is at least one or more of N-vinylpyrrolidone, acryloylmorpholine, isobornyl acrylate, cyclohexyl acrylate, 4-tert-butylcyclohexyl acrylate, 3,3,5-trimethylcyclohexyl acrylate, and dicyclopentenyl acrylate; The glass transition temperature Tg of the cyclic acrylate monomer is 10°C-110°C.

4. The highly weather-resistant acrylic film according to claim 1, characterized in that: In parts by weight, the acrylic resin A comprises 40-60 parts of an acrylic ester monomer having 2-8 carbon atoms, 20-35 parts of a hydroxyl-containing acrylic ester monomer, 10-20 parts of a cyclic acrylic ester monomer, 0.01-0.05 parts of a chain transfer agent and 0.05-1 parts of a polymerizable photoinitiator.

5. The highly weather-resistant acrylic film according to claim 1, characterized in that: The acrylate resin A is obtained by partial polymerization reaction of a polymerizable photoinitiator under ultraviolet light; The polymerization reaction is partially polymerized under ultraviolet irradiation in an inert gas environment; the inert gas is at least one of helium and nitrogen; The wavelength of the ultraviolet irradiation is 300-400 nm; the light intensity of the ultraviolet irradiation is 0.1-10 mW / cm 2 .

6. The highly weather-resistant acrylic film according to claim 5, characterized in that: The polymeric photoinitiator and the photoinitiator B are at least one of 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyldiphenoxyphosphine, 2-hydroxy-2-methyl-1-phenyl-1-propanone, benzophenone, 4-acryloyloxybenzophenone, and a, a-dimethoxy-a-phenylacetophenone; The chain transfer agent includes at least one or more of n-dodecyl mercaptan, n-octadecyl mercaptan, or pentaerythritol tetrakis(3-mercaptobutyrate).

7. The highly weather-resistant acrylic film according to claim 1, characterized in that: The crosslinking agent C is at least one or more of 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, polyethylene glycol diacrylate, and bifunctional aliphatic polyurethane acrylate; The amount of crosslinking agent C used is 0.01 to 1 part by weight relative to 100 parts by weight of high molecular weight acrylate resin A; The coupling agent D is at least one or more of γ-glycidyloxypropyltrimethoxysilane and γ-methacryloxypropyltrimethoxysilane; The amount of coupling agent D used is 0.01 to 1 part by weight relative to 100 parts by weight of high molecular weight acrylic resin A.

8. A method for preparing the highly weather-resistant acrylic film according to any one of claims 1 to 7, characterized in that: The preparation method comprises: mixing a high molecular weight acrylic resin A, a photoinitiator B, a crosslinking agent C, and a coupling agent D, degassing the mixture, coating the mixture on a release film, and performing ultraviolet curing to obtain the acrylic film.

9. The method for preparing a highly weather-resistant acrylic film according to claim 8, wherein: The curing includes curing under ultraviolet light, low-pressure or high-pressure mercury lamp, the wavelength of the curing light source is 300-400nm; the curing light intensity is 1-50 mW / cm 2 ; The total radiation energy of the curing is 800-10000mJ.

10. A highly weather-resistant acrylic film according to any one of claims 1 to 7 and a highly weather-resistant acrylic film prepared by the preparation method according to any one of claims 8 to 9, wherein the application of the highly weather-resistant acrylic film in the field of vehicle-mounted displays satisfies strict high-temperature resistance requirements.

Images