Highly transparent and super weather-resistant protective film, and preparation method and application thereof

Abstract

The application discloses a high-transparency and high-weather-resistance protective film as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials. The self-adhesive layer composition provided by the application is prepared by optimizing the components in the self-adhesive layer and the formula of the components and limiting the parameters of the components, so that the obtained self-adhesive layer composition can be applied in the preparation of a subsequent protective film, and the self-adhesive layer composition has appropriate peeling force, excellent light transmittance and weather resistance, and in particular, excellent ultraviolet resistance and high-temperature and high-humidity resistance.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a high-transparency, ultra-weather-resistant protective film, its preparation method, and its application. Background Technology

[0002] In recent years, with economic and social development, people have not only pursued high-quality products but also placed new demands on their quality of life. Consequently, the number of elevators has been gradually increasing. Furthermore, during elevator transportation and use, external forces such as friction necessitate the protection of material surfaces for aesthetic reasons, preventing damage from dust and corrosive gases. This is especially important since many elevators are directly exposed to the outdoor environment. Self-adhesive film is a protective film developed to address this need. It adheres tightly to the surface of objects through its self-adhesive layer and can be removed during assembly or use, effectively protecting the material surface.

[0003] Existing self-adhesive films are produced by adding white and black masterbatches to the intermediate and surface layers through multi-layer co-extrusion to provide a masking effect and protect the adhesive layer. However, this affects the aesthetics and wastes manpower and resources during the manufacturing process. Patent CN 109367146 A discloses an ultra-weather-resistant solar cell protective film and its preparation method. It uses PVDF as a barrier layer, adds a portion of the barrier layer, and adds ultraviolet absorbers and mineral fillers as light absorbers to prepare a weather-resistant film. However, the addition of mineral ultraviolet absorbers reduces the light transmittance of the material, affecting its overall light transmittance. Summary of the Invention

[0004] Based on the deficiencies of existing technologies, the purpose of this invention is to provide a high-transmittance, ultra-weather-resistant protective film with excellent light transmittance, good weather resistance, and suitable self-adhesion, as well as its preparation method and application.

[0005] To achieve the above objectives, in a first aspect of the present invention, the present invention provides a self-adhesive layer composition comprising the following components in parts by weight: 53-82 parts of styrene-based thermoplastic elastomers (SBCs), 13-37 parts of tackifying resin, 2-9 parts of maleic anhydride-grafted polypropylene, and 0.1-1 parts of weather-resistant additives.

[0006] The weather-resistant additives include light absorbers and light stabilizers, and the mass ratio of the light absorbers to the light stabilizers is light absorber:light stabilizer = (1-1.5):1;

[0007] The light absorber includes at least one of 2-hydroxy-4-n-octyloxybenzophenone and 2-(5-chloro-2-benzyltriazolyl)-6-tert-butyl-p-cresol;

[0008] The light stabilizer includes at least one of polymerizable hindered amine light stabilizers and 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane, wherein the average molecular weight of the light stabilizer is 2000-3000.

[0009] The present invention provides a self-adhesive layer composition, which, by optimizing the components and their formulation in the self-adhesive layer and defining the parameters of the components, enables the obtained self-adhesive layer composition to have suitable peel strength, excellent light transmittance and weather resistance when applied to the preparation of subsequent protective films. Specifically, it has excellent resistance to ultraviolet radiation and resistance to high temperature and high humidity.

[0010] Specifically, under the synergistic effect of specific types of light absorbers and specific types of light stabilizers with specific average molecular weight ranges, maleic anhydride-grafted polypropylene can achieve excellent compounding effects, thereby obtaining good UV resistance and high temperature and humidity resistance of the product, while avoiding the problem of white spots caused by precipitation on the material surface; and also ensuring that the product has excellent light transmittance.

[0011] The average molecular weight of the light stabilizer was characterized using gel permeation chromatography (GPC).

[0012] For example, the styrene-based elastomer can be any point value or any two-point range value between 53 and 82 parts, such as 55-80 parts, or 53, 55, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82 parts, etc.; the tackifying resin can be any point value or any two-point range value between 13 and 37 parts, such as 15-35 parts, or 13, 15, 18, 20, 22, 24, 26, 28 parts. The amounts can be 30 parts, 32 parts, 34 parts, 36 parts, 37 parts, etc.; the maleic anhydride-grafted polypropylene can be any point value or any two-point range value between 2 and 9 parts, for example, it can be 3-8 parts, or it can be 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, etc.; the weather-resistant additive can be any point value or any two-point range value between 0.1 and 1 part, for example, it can be 0.2-0.9 parts, or it can be 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1.0 parts, etc.

[0013] For example, the mass ratio of the light absorber to the light stabilizer can be any point value or any two points between (1-1.5):1, such as 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, etc.

[0014] For example, the average molecular weight of the light stabilizer can be any point value or any two points between 2000 and 3000, such as 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, etc.

[0015] Preferably, in the self-adhesive layer composition, the mass percentage of weather-resistant additives is 0.07-1.5%, and the mass percentage of maleic anhydride-grafted polypropylene is 1.5-12%.

[0016] As a preferred embodiment of the self-adhesive layer composition of the present invention, the self-adhesive layer composition comprises the following components in parts by weight: 5-6 parts of maleic anhydride-grafted polypropylene and 0.4-0.6 parts of weather-resistant additives.

[0017] This invention has found that maleic anhydride-grafted polypropylene can have a good compounding effect with weather-resistant additives. In particular, when the mass fractions of both are further selected within the above-mentioned range, the overall effect of the resulting product is even better.

[0018] In a preferred embodiment of the self-adhesive layer composition of the present invention, the grafting rate of the maleic anhydride-grafted polypropylene is 0.4-1.5%.

[0019] The grafting rate of maleic anhydride-grafted polypropylene was tested using acid-base titration, with reference to the grafting rate of MAH.

[0020] For example, the grafting rate of the maleic anhydride-grafted polypropylene can be any point value or any two points between 0.4% and 1.5%, such as 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, etc.

[0021] Preferably, the grafting rate of the maleic anhydride-grafted polypropylene is 0.8-1.2%.

[0022] This invention has found that the grafting rate of maleic anhydride-grafted polypropylene can increase the compatibility between weather-resistant additives and matrix resins within a certain range, thereby improving the weather resistance of the product and ensuring its high light transmittance.

[0023] In a preferred embodiment of the self-adhesive layer composition of the present invention, the mass ratio of 2-hydroxy-4-n-octyloxybenzophenone (UV-531) to 2-(5-chloro-2-benzyltriazolyl)-6-tert-butyl-p-cresol (UV-326) in the light absorber is (0-1.5):1.

[0024] Preferably, in the light absorber, the mass ratio of 2-hydroxy-4-n-octyloxybenzophenone (UV-531) to 2-(5-chloro-2-benzyltriazolyl)-6-tert-butyl-p-cresol (UV-326) is (0.1-1.5):1.

[0025] For example, the mass ratio of 2-hydroxy-4-n-octyloxybenzophenone to 2-(5-chloro-2-benzyltriazolyl)-6-tert-butyl-p-cresol can be any point value or any two points within the range of (0.1-1.5):1, such as 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, etc.

[0026] In a preferred embodiment of the self-adhesive layer composition of the present invention, the mass ratio of the polymerizable hindered amine light stabilizer and 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane (UV-119) is (0-8):1.

[0027] Preferably, the mass ratio of the polymeric hindered amine light stabilizer to 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane is (0.5-8):1.

[0028] For example, the mass ratio of the polymerizable hindered amine light stabilizer to 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane can be any point value or any two points within the range of (0.5-8):1, such as 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, etc.

[0029] Preferably, the polymeric hindered amine light stabilizer includes UV-944.

[0030] In a preferred embodiment of the self-adhesive layer composition of the present invention, the styrene-based thermoplastic elastomer has a number-average molecular weight of 30,000-90,000 and a styrene content of 8-33%.

[0031] The styrene content in styrene-based thermoplastic elastomers was determined by Fourier transform attenuated total reflectance infrared spectroscopy (FTIR-ATR). The total styrene content at different concentrations was measured, and the number-average molecular weight was characterized by gel permeation chromatography (GPC).

[0032] For example, the number-average molecular weight of the styrene-based thermoplastic elastomer can be any value between 30,000 and 90,000, or any two values ​​between these values. For instance, it can be 50,000-60,000, 50,000-90,000, or 30,000, 40,000, 50,000, 60,000, 70,000, 80,000, 90,000, etc. Within the range of 30,000-90,000 given in this invention, the technical effects of this invention can be achieved. In the styrene-based thermoplastic elastomer, the styrene content can be any value between 8% and 33%, or any two values ​​between these values. For instance, the styrene content can be 13-15%, 8-15%, 15-33%, etc., or 8%, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 25%, 28%, 30%, 33%, etc. Within the range of 8%-33% given in this invention, the technical effects of this invention can be achieved.

[0033] Preferably, the styrene-based thermoplastic elastomer has a number-average molecular weight of 50,000-60,000 and a styrene content of 12-15%.

[0034] As a preferred embodiment of the self-adhesive layer composition of the present invention, the styrene-based thermoplastic elastomer includes at least one of SBS, SEBS, SIS, and SEPS.

[0035] In a preferred embodiment of the self-adhesive layer composition of the present invention, the number-average molecular weight of the tackifying resin is 400-2000 g / mol.

[0036] The number-average molecular weight of the tackifying resin was tested according to GB / T21863-2008.

[0037] For example, the number-average molecular weight of the tackifying resin can be any point value or any two points between 400-2000 g / mol, such as 500-1000 g / mol, 500-1200 g / mol, 1200-2000 g / mol, or 400 g / mol, 600 g / mol, 800 g / mol, 1000 g / mol, 1200 g / mol, 1400 g / mol, 1600 g / mol, 1800 g / mol, 2000 g / mol, etc.

[0038] Preferably, the number-average molecular weight of the tackifying resin is 1000-1200 g / mol.

[0039] In a preferred embodiment of the self-adhesive layer composition of the present invention, the tackifying resin is at least one of hydrogenated petroleum resin, terpene resin, and rosin ester.

[0040] In a second aspect, the present invention provides a high-transparency, ultra-weather-resistant protective film comprising, from bottom to top, a self-adhesive layer, a core layer, and a surface layer, wherein the self-adhesive layer comprises the self-adhesive layer composition described in the present invention.

[0041] In a preferred embodiment of the high-transparency and ultra-weather-resistant protective film of the present invention, the thickness of the self-adhesive layer is 5-15 μm, and the thickness ratio of the self-adhesive layer, the core layer and the surface layer is 1:(2-12):1.

[0042] Preferably, the thickness ratio of the adhesive layer, core layer and surface layer is 1:(3-5):1.

[0043] The inventors discovered that when the thickness ratio of the self-adhesive layer, core layer, and surface layer is within the above range, the resulting product exhibits superior performance.

[0044] As a preferred embodiment of the high-transparency and ultra-weather-resistant protective film of the present invention, the core layer comprises the following components in parts by weight: 99-100 parts of matrix resin A and 0-1 parts of additive A.

[0045] As a preferred embodiment of the high-transparency and ultra-weather-resistant protective film of the present invention, the surface layer comprises the following components in parts by weight: 99-100 parts of matrix resin B and 0-1 parts of additive B.

[0046] Preferably, the matrix resin A and matrix resin B are each independently selected from polypropylene or polyethylene, and the additives A and B are each independently selected from at least one of antioxidants, weathering agents, opening agents, and slip agents.

[0047] More preferably, the melt index of the polypropylene or polyethylene is 3-15 g / 10 min. The test conditions for the melt index of the polypropylene are 230°C and 2.16 kg, and the test conditions for the melt index of the polyethylene are 190°C and 2.16 kg.

[0048] The effects of the present invention can be achieved within the range of the melt index of polypropylene or polyethylene given in the present invention; for example, the melt index of the polypropylene or polyethylene can be 3g / 10min, 5g / 10min, 7g / 10min, 9g / 10min, 11g / 10min, 12g / 10min, or 15g / 10min.

[0049] In a third aspect, the present invention provides a method for preparing the high-transparency, ultra-weather-resistant protective film, the method comprising the following steps:

[0050] (1) Mix the components of the self-adhesive layer, core layer and surface layer separately to obtain self-adhesive layer premix, core layer premix and surface layer premix;

[0051] (2) Extrude and granulate the self-adhesive layer premix to obtain the self-adhesive layer material;

[0052] (3) The self-adhesive layer material, core layer premix and surface layer premix are co-blown into a film to obtain the high-transparency and ultra-weather-resistant protective film.

[0053] The method for preparing the high-transparency and ultra-weather-resistant protective film described in this invention is simple and can produce products with different layer thicknesses and different overall thicknesses according to actual use needs, resulting in high efficiency for industrial-scale production.

[0054] As a preferred embodiment of the preparation method of the present invention, in step (3), the core layer premix, the surface layer premix and the self-adhesive layer material are respectively fed into the core layer material tank, the surface layer material tank and the self-adhesive layer material tank of the blown film machine, and then co-blown into a film.

[0055] In a preferred embodiment of the preparation method of the present invention, the extrusion granulation temperature in step (2) is 160-190°C.

[0056] In a fourth aspect, the present invention provides the application of the high-transparency, ultra-weather-resistant protective film in the preparation of electrical appliance protective films.

[0057] For example, the application of the high-transparency, ultra-weather-resistant protective film in the preparation of elevator protective films.

[0058] The beneficial effects of this invention are:

[0059] This invention provides a high-transparency, ultra-weather-resistant protective film with basic peel strength, as well as good light transmittance and weather resistance. Specifically, the peel strength of the obtained high-transparency, ultra-weather-resistant protective film is between 2.9-4.2 N / 25 mm, the light transmittance is above 89.2%, and after 1000 hours of ultraviolet irradiation, the white adhesive area is 2.7 mm². 2 / m 2 The number of white spots that appeared after 15 days of testing at 85℃ and 85% humidity was 9 per square meter. 2 the following. Detailed Implementation

[0060] To better illustrate the purpose, technical solution, and advantages of this invention, the invention will be further described below with reference to specific embodiments and comparative examples. The purpose of this description is to provide a detailed understanding of the invention, not to limit its scope. All other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of this invention. Unless otherwise specified, the experimental reagents and instruments designed in the embodiments and comparative examples of this invention are commonly used reagents and instruments; and the raw materials used in the parallel experiments of the embodiments and comparative examples of this invention are consistent.

[0061] The raw materials used in the various embodiments, comparative examples, and effect examples of this invention are as follows:

[0062] SBCs1: SEBS, SEBS G1645, number average molecular weight of 50,000, styrene content of 13%, Kraton, USA;

[0063] SBCs2: SIS, SIS 4113N, number average molecular weight of 50,000, styrene content of 15%, Taiwan Synthetic Rubber Co., Ltd.;

[0064] SBCs3: SEBS, SEBS G1651, number average molecular weight of 90,000, styrene content of 33%, Kraton, USA;

[0065] Maleic anhydride-grafted polypropylene 1:WP128, grafting rate 0.8%, Ningbo Nengzhiguang;

[0066] Maleic anhydride-grafted polypropylene 2: Fine-Blend FB122, grafting rate 1.2%, Shanghai Jiayirong;

[0067] Maleic anhydride-grafted polypropylene 3: YBL-1172, grafting rate 0.4%, Kingfa Science & Technology Co., Ltd.

[0068] Maleic anhydride-grafted polypropylene 4: PC-1-1, grafting rate 1.5%, Nanhai Baichen Polymer Materials Co., Ltd.

[0069] Maleic anhydride-grafted POE: PC-8C, grafting rate 0.8%, Nanhai Baichen Polymer Materials Co., Ltd.;

[0070] Tackifying resin 1: Hydrogenated petroleum resin, HH140, molecular weight 1200 g / mol, Guangdong Xinhua Yue Resin Technology Co., Ltd.

[0071] Tackifying resin 2: Terpene resin, SYLVARES TR7125, molecular weight 1030 g / mol, Kraton, USA;

[0072] Tackifying resin 3: Hydrogenated petroleum resin, Impera P1504, molecular weight 560 g / mol, Eastman Chemical Company, USA;

[0073] Polyethylene 1: Melt index is 3.5 g / 10 mol, type is LLDPE 3518CA, manufacturer is ExxonMobil, USA;

[0074] Polyethylene 2: Melt index is 15g / 10mol, model is LLDPE 5815, manufacturer is Dow Chemical (USA);

[0075] Light absorber 1: 2-hydroxy-4-n-octyloxybenzophenone, UV-531, commercially available;

[0076] Light absorber 2: 2-(5-chloro-2-benztriazolyl)-6-tert-butyl-p-cresol, UV-326, Tianjin Lianlong New Material Co., Ltd.;

[0077] Light absorber 3: 2,2'-methylenebis[6-(2H-benzodiyl)-4-(1,1,3,3-tetramethylbutyl)phenol, UV-360, commercially available;

[0078] Light stabilizer 1: Polymerized hindered amine light stabilizer, UV-944, CAS number 71878-19-8, molecular formula is (C 35 H 66 N8) n With an average molecular weight of 2100-3000, Nanjing Milan Chemical Co., Ltd.

[0079] Light stabilizer 2: 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane, UV-119, average molecular weight 2286, Tianjin Lianlong New Materials Co., Ltd.;

[0080] Light stabilizer 3: UV-770, CAS number 52829-07-9, molecular formula is C 28 H 52 O4N2, with an average molecular weight of 481, is produced by Tianjin Lianlong New Materials Co., Ltd.

[0081] Light stabilizer 4: UV-622, CAS number 65447-77-0, molecular formula H[C 15 H 25 O4N] n OCH3, with an average molecular weight of 3100-4000, Hubei Henglvyuan Technology Co., Ltd.

[0082] Antioxidant: A mixture of antioxidant 1010 and antioxidant 168 in a 1:1 mass ratio, commercially available;

[0083] Weather resistant agent: 2-hydroxy-4-n-octyloxybenzophenone, UV-531, commercially available;

[0084] Opening agent: Diatomaceous earth, commercially available;

[0085] Slip agent: Erucamide, commercially available.

[0086] Examples 1-18 and Comparative Examples 1-8

[0087] The present invention provides a high-transparency, ultra-weather-resistant protective film in embodiments and comparative examples, wherein the core layer comprises the following components in parts by weight: 89.8 parts of polyethylene 1, 10 parts of polyethylene 2, 0.1 parts of antioxidant and 0.1 parts of weather-resistant agent;

[0088] The surface layer comprises the following components in parts by weight: 100 parts polyethylene 1, 0.1 parts antioxidant, 0.1 parts weather resistant agent, 0.5 parts opening agent, and 0.3 parts slip agent;

[0089] The self-adhesive layer comprises the components (parts by weight) shown in Table 1-3:

[0090] Table 1

[0091]

[0092] Table 2

[0093]

[0094]

[0095] Table 3

[0096]

[0097]

[0098] The preparation methods of the embodiments and comparative examples of this invention are as follows:

[0099] (1) Mix the components of the self-adhesive layer, core layer and surface layer separately to obtain self-adhesive layer premix, core layer premix and surface layer premix;

[0100] (2) Extrude and granulate the self-adhesive layer premix to obtain the self-adhesive layer material;

[0101] (3) The core layer premix, surface layer premix and self-adhesive layer material are respectively fed into the core layer material tank, surface material tank and self-adhesive layer material tank of the blown film machine, and then co-blown into a film to obtain a high-transparency and ultra-weather-resistant protective film.

[0102] In Examples 1-18 and Comparative Examples 1-8, the thickness of the self-adhesive layer is 10 μm, and the thickness ratio of the self-adhesive layer, core layer, and surface layer is 1:5:1.

[0103] Example 19

[0104] This embodiment provides a high-transparency, ultra-weather-resistant protective film. The only difference between the high-transparency, ultra-weather-resistant protective film and that of Embodiment 1 is that the core layer includes the following components in parts by weight: 80 parts polyethylene 1, 19 parts polyethylene 2, 0.1 parts antioxidant, and 0.1 parts weather-resistant agent; the surface layer includes the following components in parts by weight: 99 parts polyethylene 1, 0.1 parts antioxidant, 0.1 parts weather-resistant agent, 0.5 parts opening agent, and 0.3 parts slip agent.

[0105] Example 20

[0106] This embodiment provides a high-transparency, ultra-weather-resistant protective film. The only difference between the high-transparency, ultra-weather-resistant protective film and that of Embodiment 1 is that the thickness of the self-adhesive layer is 14 μm, and the thickness ratio of the self-adhesive layer, core layer, and surface layer is 1:3:1.

[0107] Example 21

[0108] This embodiment provides a high-transparency, ultra-weather-resistant protective film. The only difference between the high-transparency, ultra-weather-resistant protective film and that of Embodiment 1 is that the thickness of the self-adhesive layer is 17.5 μm, and the thickness ratio of the self-adhesive layer, core layer, and surface layer is 1:2:1.

[0109] Example 22

[0110] This embodiment provides a high-transparency, ultra-weather-resistant protective film. The only difference between the high-transparency, ultra-weather-resistant protective film and that of Embodiment 1 is that the thickness of the self-adhesive layer is 5 μm, and the thickness ratio of the self-adhesive layer, core layer, and surface layer is 1:12:1.

[0111] Example of effect

[0112] The effectiveness examples of this invention verify the performance of the high-transparency, ultra-weather-resistant protective films prepared in Examples 1-22 and Comparative Examples 1-8, including the following aspects:

[0113] 1. Peel strength: Tested according to GB / T2792-2014;

[0114] 2. Light transmittance: Tested according to GB / T 2410-2008;

[0115] 3. Weather resistance: Steel plates were selected and pretreated according to the methods in GB / T2792-2014. The prepared protective film was then rolled onto the steel plate. After UVB-313 (Type 2) filtration at 310nm, the film showed a weathering resistance of 0.48 W / (m²). 2After 1000 hours of UV irradiation (nm), the iron plate was continuously peeled off using a tensile testing machine at a rate of 5 mm / s, following the method in GB / T2792-2014. After peeling, the surface of the iron plate was observed to see if there was any residual adhesive. If there was residual adhesive, the area of ​​the residual adhesive was recorded.

[0116] 4. Precipitation test: The prepared protective film was placed in an aging chamber at 85℃ and 85% humidity for precipitation test for 15 days. The presence of white spots on the surface of the protective film was observed. If white spots were present, the number of white spots was recorded.

[0117] The results are shown in Table 4 (industry standard: weather-resistant residual adhesive area less than 3 mm²). 2 / m 2 The number of white spots precipitated is less than 10 / m² 2 );

[0118] Table 4

[0119]

[0120]

[0121] As shown in Table 4, the product obtained using the technical solution of this invention has a suitable peel force, ranging from 2.9 to 4.2 N / 25 mm. Simultaneously, the obtained product exhibits good light transmittance and weather resistance, with a light transmittance exceeding 89.2%, and a residual adhesive area of ​​2.7 mm² after 1000 hours of ultraviolet irradiation. 2 / m 2 The number of white spots observed after the double 85 test was 9 / m². 2 the following;

[0122] As can be seen from Examples 1, 6-11 and Comparative Examples 1-2, the mass ratio of light absorber to light stabilizer in weathering additives will affect the performance of the product. When the mass ratio of light absorber to light stabilizer in Comparative Examples 1-2 is not within the given range, the weather resistance of the obtained product material cannot meet the requirements, and the light transmittance of the material also decreases to a certain extent.

[0123] As can be seen from Examples 1 and Comparative Examples 3-4, both light absorbers and light stabilizers are indispensable. When no light stabilizer is added in Comparative Example 3, the residual adhesive area of ​​the obtained product is >3mm². 2 / m 2 The product's performance did not meet the requirements, and its resistance to high temperature and humidity was also poor; when no light absorber was added in Comparative Example 4, the residual adhesive area of ​​the obtained product was >3mm². 2 / m 2 Furthermore, the product's resistance to high temperature and high humidity does not meet the requirements;

[0124] As can be seen from Examples 1 and Comparative Examples 5-7, the selection of light absorbers and light stabilizers also affects the performance of the product. When the light absorbers or light stabilizers in Comparative Examples 5-7 are not within the range given in this invention, the weather resistance of the obtained product material cannot meet the requirements, and its residual adhesive area is >3mm². 2 / m 2 At the same time, the light transmittance of the material also decreases to a certain extent, and the precipitation of the material increases.

[0125] As can be seen from Examples 1, 16-18 and Comparative Example 8, maleic anhydride-grafted polypropylene also affects the performance of the product. When maleic anhydride-grafted polypropylene was not used in Comparative Example 8, the precipitation of the obtained product material increased significantly, far exceeding the product performance requirements, and the light transmittance of the product also decreased significantly.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A self-adhesive layer composition, characterized in that, The self-adhesive layer composition comprises the following components in parts by weight: 53-82 parts of styrene-based thermoplastic elastomer, 13-37 parts of tackifying resin, 2-9 parts of maleic anhydride-grafted polypropylene, and 0.1-1 parts of weather-resistant additives; The weather-resistant additives include light absorbers and light stabilizers, and the mass ratio of the light absorbers to the light stabilizers is light absorber:light stabilizer = (1-1.4):1; The light absorber includes at least one of 2-hydroxy-4-n-octyloxybenzophenone and 2-(5-chloro-2-benzyltriazolyl)-6-tert-butyl-p-cresol; The light stabilizer includes at least one of polymerizable hindered amine light stabilizers and 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane, wherein the average molecular weight of the light stabilizer is 2000-3000.

2. The self-adhesive layer composition according to claim 1, characterized in that, The self-adhesive layer composition comprises the following components in parts by weight: 5-6 parts maleic anhydride-grafted polypropylene and 0.4-0.6 parts weather-resistant additives.

3. The self-adhesive layer composition according to claim 1, characterized in that, The grafting rate of the maleic anhydride-grafted polypropylene is 0.4-1.5%.

4. The self-adhesive layer composition according to claim 1, characterized in that, Satisfy at least one of the following: a. In the light absorber, the mass ratio of 2-hydroxy-4-n-octyloxybenzophenone to 2-(5-chloro-2-benzyltriazolyl)-6-tert-butyl-p-cresol is (0-1.5):1; b. In the light stabilizer, the mass ratio of the polymeric hindered amine light stabilizer and 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane is (0-8):

1.

5. The self-adhesive layer composition according to claim 4, characterized in that, In the light absorber, the mass ratio of 2-hydroxy-4-n-octyloxybenzophenone to 2-(5-chloro-2-benzyltriazolyl)-6-tert-butyl-p-cresol is (0.1-1.5):1; And / or, in the light stabilizer, the mass ratio of the polymerizable hindered amine light stabilizer to 1,5,8,12-tetra[4,6-bis(N-butyl-N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane is (0.5-8):

1.

6. The self-adhesive layer composition according to claim 1, characterized in that, Satisfy at least one of the following: c. The styrene-based thermoplastic elastomer has a number-average molecular weight of 30,000-90,000 and a styrene content of 8-33%; d. The styrene-based thermoplastic elastomer includes at least one of SBS, SEBS, SIS, and SEPS; e. The number-average molecular weight of the tackifying resin is 400-2000 g / mol; f. The tackifying resin is at least one of hydrogenated petroleum resin, terpene resin, and rosin ester.

7. A high-transparency, ultra-weather-resistant protective film, characterized in that, The layers, from bottom to top, include a self-adhesive layer, a core layer, and a surface layer, wherein the self-adhesive layer comprises the self-adhesive layer composition as described in any one of claims 1-6.

8. The high-transparency, ultra-weather-resistant protective film according to claim 7, characterized in that, The thickness of the self-adhesive layer is 5-15 μm, and the thickness ratio of the self-adhesive layer, the core layer and the surface layer is 1:(2-12):

1.

9. The high-transparency, ultra-weather-resistant protective film according to claim 7, characterized in that, The core layer comprises the following components in parts by weight: matrix resin A 99-100 parts, additive A 0-1 part; And / or, the surface layer comprises the following components in parts by weight: 99-100 parts of matrix resin B and 0-1 parts of additive B.

10. The method for preparing the high-transparency, ultra-weather-resistant protective film according to any one of claims 7-9, characterized in that, Includes the following steps: (1) Mix the components of the self-adhesive layer, core layer and surface layer separately to obtain self-adhesive layer premix, core layer premix and surface layer premix; (2) Extrude and granulate the self-adhesive layer premix to obtain the self-adhesive layer material; (3) The self-adhesive layer material, core layer premix and surface layer premix are co-blown into a film to obtain the high-transparency and ultra-weather-resistant protective film.

11. The application of the high-transparency, ultra-weather-resistant protective film as described in any one of claims 7-9 in the preparation of electrical appliance protective films.

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