A high-temperature resistant low-shrinkage silicone protective film and preparation method thereof

Abstract

The present invention relates to the field of protective films, and specifically to a high-temperature resistant, low-shrinkage silicone protective film and a preparation method thereof. The silicone protective film of the present invention comprises a silicone film layer, a silicone pressure-sensitive adhesive layer, and an isolation film layer, wherein the silicone pressure-sensitive adhesive layer is located on at least one surface of the silicone film layer, and the isolation film layer is located on the surface of the silicone pressure-sensitive adhesive layer away from the silicone film layer; the silicone film layer comprises a first MQ resin, silicone rubber, and a first silicone oil. The high-temperature resistant, low-shrinkage silicone protective film of the present invention has good dimensional stability at high temperatures, can well fit the surface of the curved object to be adhered, and the production process is simple and energy-saving. The performance of the silicone protective film is fundamentally improved, and the scope of application of the silicone protective film is expanded.

Description

Technical Field

[0001] The present invention relates to the field of protective films, and in particular to a high-temperature resistant and low-shrinkage silicone protective film and a preparation method thereof. Background Art

[0002] Conventional silicone protective films are primarily made of a PET or PI substrate coated with a silicone pressure-sensitive adhesive, which is then cured at high temperatures and then bonded to a release film. These films are mature in terms of structure and manufacturing process. They are primarily used for protection during the processing and production of electronic components, as well as for support and transfer during die-cutting. These include protective films used in the production of glass components for electronic displays and for shipping complete devices. Conventional protective films lack high-temperature stability, primarily exhibiting performance and dimensional instability, and can even cause curved surfaces to bounce off.

[0003] Therefore, the market is in great need of discovering a new type of protective film that can effectively avoid the above problems. Summary of the Invention

[0004] The present invention aims to overcome the aforementioned problems of the prior art by providing a high-temperature-resistant, low-shrinkage silicone protective film and a method for preparing the same. The present invention exhibits excellent dimensional stability at high temperatures, can conform well to curved surfaces, and features a simple and energy-efficient production process. This fundamentally improves the performance of the silicone protective film and expands its application range.

[0005] A first aspect of the present invention provides a silicone protective film, comprising a silicone film layer, an organosilicon pressure-sensitive adhesive layer, and an isolation film layer, wherein the organosilicon pressure-sensitive adhesive layer is located on at least one surface of the silicone film layer, and the isolation film layer is located on a surface of the organosilicon pressure-sensitive adhesive layer away from the silicone film layer;

[0006] The silicone film layer includes a first MQ resin, silicone rubber and a first silicone oil.

[0007] In one embodiment, the mass ratio of the first MQ resin, the silicone rubber, and the first silicone oil in the silicone film layer is (4-7): (1-5): (1-5).

[0008] In one example, the organic silicone pressure-sensitive adhesive layer includes a second MQ resin, a second silicone oil, and a modified silicone resin.

[0009] In one embodiment, the mass ratio of the second MQ resin, the second silicone oil, and the modified silicone resin in the organic silicone pressure-sensitive adhesive layer is (0.05-4):(6-8):(0.01-0.2).

[0010] In one example, the first MQ resin and the second MQ resin are each independently selected from one or more of vinyl MQ resin, phenyl MQ resin, phenyl vinyl MQ resin, hydroxy MQ resin, methyl vinyl MQ resin, and methyl MQ resin.

[0011] In one example, the first silicone oil and the second silicone oil are each independently selected from one or more of methylphenyl silicone oil, methylphenylvinyl silicone oil, vinyl silicone oil and phenylvinyl silicone oil;

[0012] Preferably, the first silicone oil and the second silicone oil are each independently selected from phenyl vinyl silicone oil;

[0013] Preferably, the viscosity of the phenyl vinyl silicone oil is 500-1000 mPas, the relative molar content of phenyl groups in the phenyl vinyl silicone oil is 6-10%, and the relative molar content of vinyl groups in the phenyl vinyl silicone oil is 0.2-0.5%.

[0014] In one example, the silicone rubber includes one or more of methyl silicone rubber, methyl vinyl silicone rubber, methyl phenyl vinyl silicone rubber, fluorosilicone rubber, vinyl silicone rubber and liquid silicone rubber;

[0015] Preferably, the molecular weight of the silicone rubber is 300,000-700,000;

[0016] Preferably, the silicone rubber is vinyl silicone rubber.

[0017] In one embodiment, the modified silicone resin is one or more of epoxy-modified silicone resin, alkyd-modified silicone resin, alkyl-modified silicone resin and acrylic-modified silicone resin;

[0018] Preferably, the modified silicone resin is acrylic modified silicone resin.

[0019] In one embodiment, in the silica gel film layer, the ratio of M:Q in the first MQ resin is (1-1.4):1; and / or,

[0020] In the organic silicone pressure-sensitive adhesive layer, the ratio of M:Q in the second MQ resin is (0.6-0.9):1.

[0021] The second aspect of the present invention provides a method for preparing the silicone protective film according to the first aspect of the present invention, comprising the following steps:

[0022] providing a carrier film layer;

[0023] A silicone film layer is provided on the surface of the carrier film layer and is cured;

[0024] Arranging an organic silicon pressure-sensitive adhesive layer on the surface of the silicone film layer and performing a curing treatment;

[0025] An isolation film is arranged on the surface of the organic silicone pressure-sensitive adhesive layer, and the supporting film layer is removed and rolled up.

[0026] Through the above technical solution, the present invention has at least the following advantages compared with the prior art:

[0027] (1) The high temperature resistant and low shrinkage silicone protective film of the present invention has good dimensional stability at high temperatures;

[0028] (2) The high temperature resistant and low shrinkage silicone protective film of the present invention can well fit the surface of the curved surface to be adhered;

[0029] (3) The high temperature resistant and low shrinkage silicone protective film of the present invention fundamentally improves the performance of the silicone protective film and expands the scope of application of the silicone protective film;

[0030] (4) The preparation method of the high-temperature resistant and low-shrinkage silicone protective film of the present invention is simple and energy-saving. Compared with the traditional coating method, it has the advantages of fewer coating steps, low process loss, and saved production costs. It will also be the future development direction of the coating industry.

[0031] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The figure shows the structure of the high temperature resistant low shrinkage silicone protective film provided by the present invention;

[0033] Figure 2 、 Figure 3 、 Figure 4 Shown is a schematic diagram of the preparation process of the high-temperature resistant and low-shrinkage silicone protective film provided by the present invention.

[0034] Description of Reference Numerals

[0035] 0-1, carrier film layer; 1-1, silicone film layer; 1-2, silicone pressure-sensitive adhesive layer; 1-3, isolation film layer. DETAILED DESCRIPTION

[0036] The following is a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0037] In the existing technology, conventional PET silicone protective films have poor stability at high temperatures, mainly due to unstable chemical properties and dimensional instability. First, the performance instability is manifested in the glass production process or the shipping protection process, where the protective film often causes contamination on the glass surface, such as transfer, residual glue, and degumming. Among them, when PET is exposed to high temperatures, some fillers precipitate and some small molecular groups in the adhesive layer precipitate, resulting in abnormal appearance or abnormal glass surface energy, which in turn leads to abnormal subsequent processing, especially during the processing in high-temperature environments. In addition, its dimensional instability is manifested in the protective film being prone to shrinkage and bubble formation when it encounters a high-temperature environment during use. Although PI-based silicone protective films can overcome this defect, due to its low surface energy, the silicone formula also needs to add an adhesion promoter containing a large amount of small molecular components, resulting in significant precipitation of small molecular components under high-temperature conditions. At the same time, the high cost of PI film makes the product less cost-effective.

[0038] In addition, due to the high film weight of the existing conventional silicone protective film, when applied to curved surfaces, the curved surface may bounce off after long-term adhesion, making the adhered object susceptible to damage. In addition, the low-film-weight base film has poor temperature resistance under tension, making it impossible to coat the silicone protective film on a flexible substrate, thus limiting its use in curved surface protection.

[0039] In response to the above problems, the inventors of the present invention have made improvements in product structure and formula design, forming a silicone film layer and an organic silicone pressure-sensitive adhesive layer, which effectively solves the above problems.

[0040] The first aspect of the present invention provides a silicone protective film, such as Figure 1 As shown, it includes a silicone film layer 1-1, a silicone pressure-sensitive adhesive layer 1-2 and an isolation film layer 1-3, the silicone pressure-sensitive adhesive layer 1-2 is located on at least one surface of the silicone film layer 1-1, and the isolation film layer 1-3 is located on the surface of the silicone pressure-sensitive adhesive layer 1-2 away from the silicone film layer 1-1; the silicone film layer 1-1 includes a first MQ resin, silicone rubber and a first silicone oil.

[0041] In one embodiment, the organic silicone pressure-sensitive adhesive layer 1-2 is located on one surface of the silicone film layer 1-1.

[0042] MQ resin is composed of monofunctional chain segments (R3SiO 1 / 2 M unit (abbreviated as "mono") and tetrafunctional chain segment (SiO 4 / 2 It is an organic / inorganic hybrid polysiloxane composed of Q units (abbreviated as "quad") with a special structure.

[0043] The inventors of the present invention have found that by adjusting the contents of the first MQ resin, silicone rubber and first silicone oil in the silicone film layer, a flexible protective film suitable for objects with different curved surfaces can be obtained, and its surface has excellent tensile strength and thermal stability.

[0044] In one embodiment, the mass ratio of the first MQ resin, the silicone rubber, and the first silicone oil in the silicone film layer is (4-7): (1-5): (1-5).

[0045] In one example, the first MQ resin includes one or more of vinyl MQ resin, phenyl MQ resin, phenyl vinyl MQ resin, hydroxy MQ resin, methyl vinyl MQ resin, and methyl MQ resin.

[0046] In one example, the first MQ resin is a methyl vinyl MQ resin.

[0047] The inventors of the present invention have discovered that by adjusting the amount of methyl vinyl MQ resin added, silicone layers with different film weights can be obtained, thereby controlling the flexibility of the product so that it is suitable for objects with different curved surfaces.

[0048] In one example, the first silicone oil includes one or more of methylphenyl silicone oil, methylphenylvinyl silicone oil, vinyl silicone oil, and phenylvinyl silicone oil.

[0049] Preferably, the first silicone oil is phenyl vinyl silicone oil.

[0050] Preferably, the viscosity of the phenyl vinyl silicone oil is 500-1000 mPas, the relative molar content of phenyl groups in the phenyl vinyl silicone oil is 6-10%, and the relative molar content of vinyl groups in the phenyl vinyl silicone oil is 0.2-0.5%.

[0051] The inventors of the present invention have discovered that the addition of phenyl vinyl silicone oil can solve the problem of poor dimensional stability of silicone membranes during high-temperature use. Furthermore, compared to conventional silicone membrane formulations, the omission of silane coupling agents can reduce high-temperature precipitation.

[0052] In one example, the silicone rubber includes one or more of methyl silicone rubber, methyl vinyl silicone rubber, methyl phenyl vinyl silicone rubber, fluorosilicone rubber, vinyl silicone rubber, and liquid silicone rubber.

[0053] Preferably, the molecular weight of the silicone rubber is 300,000-700,000.

[0054] Preferably, the silicone rubber is vinyl silicone rubber.

[0055] In one example, in the silicone film layer, the ratio of M:Q in the first MQ resin is (1-1.4):1.

[0056] In one embodiment, the composition of the silicone membrane layer further includes the following additives, including a cross-linking agent, an inhibitor, and a catalyst.

[0057] In one example, the crosslinking agent is one or more of phenyl hydrogen-containing silicone oil, methyl hydrogen-containing silicone oil, and terminal hydroxyl hydrogen-containing silicone oil.

[0058] In one embodiment, the inhibitor is an alkynol compound.

[0059] In one example, the alkynol compound includes one or more of methylbutynol, acetylene cyclohexanol, tert-butyl cyclohexanol, phenylbutynol, 3,5-dimethyl-1-hexyn-3-ol, and 3,6-dimethyl-1-heptyn-3-3,7,11-trimethyldodecyn-3-ol (TMDO).

[0060] In one embodiment, the catalyst is a Custer platinum catalyst.

[0061] This high-performance platinum catalyst, also known as platinum water or Karst catalyst, catalyzes hydrosilylation reactions and inhibits side reactions associated with Si-Vi and Si-H reactions, overcoming the yellowing or blackening of products associated with other catalysts. This results in rapid vulcanization, high efficiency, and reduced dosage; it can also produce highly transparent, colorless products. It can be used as a catalyst for liquid addition silicone rubber, silicone gel, high-temperature addition silicone rubber, and silicone ink addition-type rubber adhesives.

[0062] In one embodiment, the thickness of the silicone film layer is 5-200 μm.

[0063] In one embodiment, the specific content of each component in the silicone membrane layer is: the content of the methyl vinyl MQ resin is 40-70 parts by weight, the content of the vinyl silicone rubber is 10-50 parts by weight, the content of the phenyl vinyl silicone oil is 10-50 parts by weight, the content of the cross-linking agent is 1-2.5 parts by weight, the content of the inhibitor is 0.5-1 part by weight, and the content of the catalyst is 1-2.5 parts by weight.

[0064] The main components of the silicone film layer in the present invention are methyl vinyl MQ resin, vinyl silicone rubber and phenyl vinyl silicone oil. By adding a crosslinking agent, an inhibitor and a Custer platinum catalyst to form a film at high temperature, the surface of the silicone protective film has excellent tensile strength and thermal stability.

[0065] By adjusting the amount of phenyl vinyl silicone oil added to the silicone film layer, the silicone protective film can have dimensional stability during high-temperature use.

[0066] In one example, the organic silicone pressure-sensitive adhesive layer includes a second MQ resin, a second silicone oil, and a modified silicone resin.

[0067] The inventors of the present invention have discovered that the protective film can have good stability by adjusting the contents of the second MQ resin, the second silicone oil and the modified silicone resin in the organic silicone pressure-sensitive adhesive layer.

[0068] In one embodiment, the mass ratio of the second MQ resin, the second silicone oil, and the modified silicone resin in the organic silicone pressure-sensitive adhesive layer is (0.05-4):(6-8):(0.01-0.2).

[0069] In one example, the second MQ resin includes one or more of vinyl MQ resin, phenyl MQ resin, phenyl vinyl MQ resin, hydroxyl MQ resin, methyl vinyl MQ resin, and methyl MQ resin.

[0070] In one example, the second MQ resin is a methyl MQ resin.

[0071] In one example, the second silicone oil includes one or more of methylphenyl silicone oil, methylphenylvinyl silicone oil, vinyl silicone oil, and phenylvinyl silicone oil.

[0072] Preferably, the second silicone oil is phenyl vinyl silicone oil.

[0073] Preferably, the viscosity of the phenyl vinyl silicone oil is 500-1000 mPas, the relative molar content of phenyl groups in the phenyl vinyl silicone oil is 6-10%, and the relative molar content of vinyl groups in the phenyl vinyl silicone oil is 0.2-0.5%.

[0074] In the organic silicon pressure-sensitive adhesive layer, different peeling force performance requirements are achieved by adjusting the amount of phenyl vinyl silicone oil used, wherein the phenyl vinyl silicone oil contains a large number of phenyl groups and has high temperature stability.

[0075] In one example, the modified silicone resin is one or more of epoxy-modified silicone resin, alkyd-modified silicone resin, alkyl-modified silicone resin, and acrylic-modified silicone resin.

[0076] Preferably, the modified silicone resin is acrylic modified silicone resin.

[0077] In the silicone pressure-sensitive adhesive layer, acrylic modified silicone resin is mainly used as a light-curing prepolymer, which has the function of light-curing shrinkage and is mainly added when protecting the surface of the object being attached.

[0078] In one embodiment, in the organic silicone pressure-sensitive adhesive layer, the ratio of M:Q in the second MQ resin is (0.6-0.9):1.

[0079] The composition of the organic silicone pressure-sensitive adhesive layer includes the following additives, including a photoinitiator, a cross-linking agent, an inhibitor, and a catalyst.

[0080] The photoinitiator includes one or more of benzophenone (BP), thioxanthone (ITX), anthracene aldehyde (2-EA) and aromatic ketone compounds thereof.

[0081] In one embodiment, the organic silicone pressure-sensitive adhesive layer is mainly composed of methyl MQ resin and phenyl vinyl silicone oil, and acrylic modified silicone resin is added. By adding a photoinitiator, a crosslinking agent, an inhibitor and a catalyst, the organic silicone pressure-sensitive adhesive layer is formed through high-temperature curing.

[0082] In one embodiment, the specific content of each component in the silicone pressure-sensitive adhesive layer is: the content of the methyl MQ resin is 0.5-40 parts by weight, the content of the phenyl vinyl silicone oil is 60-80 parts by weight, the content of the acrylic modified silicone resin is 0.1-2 parts by weight, the content of the photoinitiator is 0.1-1 parts by weight, the content of the cross-linking agent is 1-2 parts by weight, the content of the inhibitor is 0.5-1 parts by weight, and the content of the catalyst is 1-2.5 parts by weight.

[0083] The isolation film layer can be any one of PET, PP, PE, PI, PC, PMMA and PET fluoroplastic release film according to actual customer needs.

[0084] The PET, PP, PE, PI, PC, PMMA and PET fluoroplastic release films in the present invention can all be obtained commercially.

[0085] The second aspect of the present invention provides a method for preparing the silicone protective film described in the first aspect of the present invention, comprising the following steps: providing a carrier film layer 0-1; arranging a silicone film layer 1-1 on the surface of the carrier film layer 0-1 and performing a curing treatment; arranging a silicone pressure-sensitive adhesive layer 1-2 on the surface of the silicone film layer 1-1 and performing a curing treatment; arranging an isolation film 1-3 on the surface of the silicone pressure-sensitive adhesive layer 1-2, removing the carrier film layer 0-1 and winding it up.

[0086] The surface of the carrier film layer can be made into different shapes according to the customer's requirements for product surface performance, such as a textured, concave-convex, or frosted surface, and can also be made into an appearance with a transfer pattern function.

[0087] The material of the carrier film layer in the present invention may be the same as or different from the material of the isolation film layer in the present invention.

[0088] In one example, the carrier film layer is made of the same material as the isolation film layer.

[0089] In one embodiment, the carrier film layer is a PET fluoroplastic release film.

[0090] In one embodiment, in the preparation of the silicone membrane layer, the preparation method of the silicone membrane layer liquid is: first, phenyl vinyl silicone oil and vinyl silicone rubber are mixed in proportion, and a dual planetary power mixer is used to mix for 15-25 minutes, with a dispersion speed of 600-800 r / min, time 8-12 minutes, 1400-1600 r / min, time 8-12 minutes, and at the same time, cooling water is passed through the mixer container to maintain the temperature at 40-60°C. Then, add methyl vinyl MQ resin in proportion and slowly introduce it into the above mixed glue, maintaining the dispersion speed at 400-600 r / min. After the addition, adjust the mixer speed to 1000-1400 r / min and maintain it for 15-25 minutes. Finally, let it stand and cool to below 30°C, add the crosslinker in proportion at 300-700 r / min for 3-5 minutes, add the inhibitor at 300-700 r / min for 5-10 minutes, and add the catalyst at 300-700 r / min for 15-25 minutes. Let it stand and defoam for 5-10 minutes before use.

[0091] In one embodiment, in preparing the silicone pressure-sensitive adhesive layer, the preparation method of the silicone pressure-sensitive adhesive layer liquid is as follows: first, phenyl vinyl silicone oil and methyl MQ resin are mixed in a certain proportion using a dual planetary power mixer at a dispersion speed of 800-1200 r / min for 10-20 minutes, while warm water is passed through the mixer container to maintain the temperature at 40-60°C. Then, acrylic modified silicone resin is added in proportion to the above-mentioned mixture, and the mixture is dispersed for 8-10 minutes at a dispersion speed of 800-1200 r / min. Finally, the mixture is allowed to cool to below 30°C, and a crosslinker is added in proportion at 300-700 r / min for 3-5 minutes, an inhibitor is added at 300-700 r / min for 5-10 minutes, a catalyst is added at 300-700 r / min for 15-25 minutes, and finally, a photoinitiator is added at 300-700 r / min for 15-25 minutes. The mixture is allowed to stand for defoaming for 5-10 minutes before use.

[0092] The silicone film layer and the organosilicon pressure-sensitive adhesive layer in the present invention may be provided by coating or by other commonly used spraying methods in the art.

[0093] The coating method can be selected from a segmented coating method and a multi-layer co-extrusion coating method. Among them, the segmented coating method has a relatively simple coating head design, is relatively sufficient in curing, is relatively fast in speed, and has relatively high production efficiency, but the equipment takes up a relatively large space, has more operating stations, and requires a relatively large number of personnel. The multi-layer co-extrusion coating method has a relatively complex coating head, requires a large equipment investment, affects the coating accuracy, and has a relatively slow curing speed and relatively low production efficiency. Its advantages and disadvantages are basically opposite to those of the segmented trial coating method.

[0094] In one example, the specific operating steps when using the segmented coating method are as follows: a silicone film layer liquid is coated on the 20-100 μm PET release surface, and after the first high-temperature curing at a temperature of 130-150°C for 0.5-3 minutes, a silicone pressure-sensitive adhesive layer liquid is coated on the surface through a second coating head, and after another high-temperature curing at a temperature of 140-160°C for 1-3 minutes, an isolation film is attached, the first layer of carrier release film is removed, and the finished product is rolled up at the same time.

[0095] In one example, the specific operating steps when using a multi-layer co-extrusion coating method are as follows: on the release surface of a 20-100 μm PET fluoroplastic release film, a multiple co-extrusion coating head is used, the first layer is coated with a silicone film layer liquid, and the second layer is coated with a silicone pressure-sensitive adhesive layer liquid. After high-temperature curing at a temperature of 140-170°C for 1.5-5 minutes, the first layer of the carrier release film is removed and the finished product is rolled up at the same time.

[0096] The present invention tests the performance of the high temperature resistant low shrinkage silicone protective film according to the following test method:

[0097] The total thickness of the silicone film layer and the protective film is tested using a thousandths display thickness gauge in accordance with GB / T7125-1999.

[0098] The hardness test method is to use a Shore hardness tester to test, referring to GB / T 2411-2008.

[0099] The transparency test method refers to ASTM D1003.

[0100] The tensile strength and elongation at break were tested using a universal material testing machine in accordance with GB / T30776-2014.

[0101] The steel plate peeling force test is carried out using a peeling force tester, referring to GB / T 2792-2014.

[0102] The high-temperature dimensional stability test method is to cut the product into L×W=100×100mm size and laminate it to plain glass at 200℃ for 2h, put it into the oven, take it out after 2h, and let it stand at room temperature for 30 minutes to observe the appearance changes. At the same time, the change rate of length and width is tested.

[0103] Test the haze change of the adhered glass. Test the pollution performance of the adhered object under high and low temperature conditions: adhere to plain glass, place it in high and low temperature environment for 72 hours, and test the change rate of light transmittance and haze of the adhered glass.

[0104] Pollution performance test: stick to plain glass, let it stand at room temperature for 72 hours, use a standard light box D65 light source, and check whether there is obvious foreign matter precipitation on the surface of the object.

[0105] Aging resistance test, aging resistance test under D85 / 72H conditions: stick plain glass, place it in the environment for 72 hours, remove the protective cover and observe whether there is any residual glue or debonding on the glass surface, and whether the force of removing it is obviously increased.

[0106] The protective film of the present invention can be applied to the following fields: metal product surfaces, coated metal product surfaces, plastic product surfaces, automotive product surfaces, electronic product surfaces, sign product surfaces, profile product surfaces and other product surfaces.

[0107] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0108] Example 1

[0109] (1) Prepare raw materials

[0110] (1-1) Silicone film formula:

[0111] Methyl vinyl MQ resin: 50 parts by weight; M / Q = 1 / 1;

[0112] Vinyl silicone rubber: 25 parts by weight, molecular weight 500,000;

[0113] Phenyl vinyl silicone oil: 20 parts by weight, viscosity 600 mPas, phenyl relative molar content 8%, vinyl content 0.3%;

[0114] Crosslinking agent: Dow Corning 7028, 2 parts by weight;

[0115] Inhibitor: methylbutynol, 0.7 parts by weight;

[0116] Catalyst: Dow Corning 4000, 2.3 parts by weight.

[0117] Preparation of silicone membrane material: First, mix phenyl vinyl silicone oil and vinyl silicone rubber in the above proportions, using a dual planetary power mixer for 20 minutes, with a dispersion speed of 700 r / min for 10 minutes and 1500 r / min for 10 minutes. At the same time, cool water is passed through the mixer container to maintain the temperature at 50°C. Then, slowly introduce the above-mentioned parts by weight of methyl vinyl MQ resin into the above-mentioned mixed rubber, maintaining a dispersion speed of 500 r / min. After addition, adjust the mixer speed to 1200 r / min and maintain it for 20 minutes. Finally, let it cool to below 30°C, add the crosslinker in proportion at 500 r / min for 4 minutes, add the inhibitor at 400 r / min for 8 minutes, and add the catalyst at 500 r / min for 20 minutes. Let it stand for 8 minutes to defoam before coating.

[0118] (1-2) Silicone pressure-sensitive adhesive layer formula:

[0119] Methyl MQ resin: 25 parts by weight, M:Q=0.8 / 1;

[0120] Phenyl vinyl silicone oil: 70 parts by weight, viscosity 600 mPas, phenyl relative molar content 8%, vinyl content 0.3%;

[0121] Acrylic modified silicone resin: 1 part by weight;

[0122] Photoinitiator: benzophenone (BP), 0.5 parts by weight;

[0123] Crosslinking agent: Dow Corning 7028, 1.5 parts by weight;

[0124] Inhibitor: methylbutynol, 0.8 parts by weight;

[0125] Catalyst: Dow Corning 4000, 1.2 parts by weight.

[0126] Prepare the silicone pressure-sensitive adhesive layer: First, mix phenyl vinyl silicone oil and methyl MQ resin in a certain proportion using a dual planetary power mixer for 15 minutes at a dispersion speed of 1000 r / min. Simultaneously, flow warm water through the mixer container to maintain the temperature at 50°C. Then, add acrylic modified silicone resin in proportion to the above mixture and disperse it for 9 minutes at a dispersion speed of 1000 r / min. Finally, let it cool to below 30°C. Then, add the crosslinker in proportion at 500 r / min for 4 minutes, add the inhibitor at 500 r / min for 8 minutes, add the catalyst at 500 r / min for 20 minutes, and finally add the photoinitiator at 500 r / min for 20 minutes. Let it stand for 8 minutes to defoam before coating.

[0127] (2) Preparation of protective film

[0128] The specific steps of the segmented coating method are to use 50μm PET fluorine plastic release film to coat 30μm silicone film layer, and then cure it at 140℃ for 1min (to obtain Figure 2 The structure shown in FIG) is then coated with a silicone pressure-sensitive adhesive layer on its surface by a second coating head, and then cured at 100°C / 1min and 150°C / 2min (to obtain Figure 3 The structure shown) is attached to the isolation film (obtained Figure 4 The structure shown in FIG), peel off the coating carrier release film and then roll up the finished product (obtain Figure 1 structure shown).

[0129] Example 2

[0130] The preparation method of the silicone membrane layer liquid, the organosilicon pressure-sensitive adhesive layer liquid and the protective film in Example 2 is the same as that in Example 1, except for the formula of the silicone membrane layer and the organosilicon pressure-sensitive adhesive layer.

[0131] (1) Silicone film formula:

[0132] Methyl vinyl MQ resin: 55 parts by weight, M / Q = 1 / 1;

[0133] Vinyl silicone rubber: 22 parts by weight, molecular weight 500,000;

[0134] Phenyl vinyl silicone oil: 18 parts by weight, viscosity 600 mPas, phenyl relative molar content 8%, vinyl content 0.3%;

[0135] Crosslinking agent: Dow Corning 7028, 2.2 parts by weight;

[0136] Inhibitor: methylbutynol, 0.8 parts by weight;

[0137] Catalyst: Dow Corning 4000, 2 parts by weight.

[0138] (2) Silicone pressure-sensitive adhesive layer formula:

[0139] Methyl MQ resin: 20 parts by weight, M:Q=0.8 / 1;

[0140] Phenyl vinyl silicone oil: 75 parts by weight, viscosity 600 mPas, phenyl relative molar content 8%, vinyl content 0.3%;

[0141] Acrylic modified silicone resin: 1.5 parts by weight;

[0142] Photoinitiator: benzophenone (BP), 0.3 parts by weight;

[0143] Crosslinking agent: Dow Corning 7028, 1.2 parts by weight;

[0144] Inhibitor: methylbutynol, 0.6 parts by weight;

[0145] Catalyst: Dow Corning 4000, 1.4 parts by weight.

[0146] Example 3

[0147] The preparation method of the silicone membrane layer liquid, the silicone pressure-sensitive adhesive layer liquid and the protective film in Example 3 is the same as that in Example 1, except for the formula of the silicone membrane layer and the silicone pressure-sensitive adhesive layer.

[0148] (1) Silicone film formula:

[0149] Methyl vinyl MQ resin: 45 parts by weight, M / Q=1 / 1;

[0150] Vinyl silicone rubber: 30 parts by weight, molecular weight 500,000;

[0151] Phenyl vinyl silicone oil: 20 parts by weight, viscosity 600 mPas, phenyl relative molar content 8%, vinyl content 0.3%;

[0152] Crosslinking agent: Dow Corning 7028, 1.6 parts by weight;

[0153] Inhibitor: methylbutynol, 0.9 parts by weight;

[0154] Catalyst: Dow Corning 4000, 2.5 parts by weight.

[0155] (2) Silicone pressure-sensitive adhesive layer formula:

[0156] Methyl MQ resin: 27 parts by weight, M:Q=0.8 / 1;

[0157] Phenyl vinyl silicone oil: 68 parts by weight, viscosity 600 mPas, phenyl relative molar content 8%, vinyl content 0.3%;

[0158] Acrylic modified silicone resin: 0.5 parts by weight;

[0159] Photoinitiator: benzophenone (BP), 0.6 parts by weight;

[0160] Crosslinking agent: Dow Corning 7028, 1.6 parts by weight;

[0161] Inhibitor: methylbutynol, 0.5 parts by weight;

[0162] Catalyst: Dow Corning 4000, 1.8 parts by weight.

[0163] Example 4

[0164] Example 4 is used to illustrate the effect of changing the composition of the silicone membrane layer.

[0165] Example 4a

[0166] The method is basically the same as Example 1, except that the MQ resin of the silicone membrane layer is vinyl MQ resin.

[0167] Example 4b

[0168] The method is basically the same as Example 1, except that the first silicone oil in the silicone film layer is vinyl silicone oil.

[0169] Example 4c

[0170] The method is basically the same as Example 1, except that the silicone rubber is methyl silicone rubber.

[0171] Example 5

[0172] Example 5 is used to illustrate the effect of changing the components in the silicone pressure-sensitive adhesive layer.

[0173] Example 5a

[0174] The method is basically the same as Example 1, except that the MQ resin of the silicone pressure-sensitive adhesive layer is phenyl MQ resin.

[0175] Example 5b

[0176] The method is basically the same as Example 1, except that the second silicone oil in the organic silicone pressure-sensitive adhesive layer is vinyl silicone oil.

[0177] Example 5c

[0178] It is basically the same as Example 1, except that the modified silicone resin is epoxy modified silicone resin.

[0179] Example 6

[0180] Example 6 is used to illustrate the effect of changing the M:Q ratio in MQ resin.

[0181] Example 6a

[0182] The method is basically the same as Example 1, except that the ratio of M:Q in the first MQ silicone resin is 2:1.

[0183] Example 6b

[0184] The method is basically the same as Example 1, except that the ratio of M:Q in the second MQ silicone resin is 0.3:1.

[0185] Comparative Example 1

[0186] Comparative Example 1: A silicone protective film is prepared using a conventional formula in the art. The silicone film layer is replaced with a PI film with a thickness of 25 μm. A primer is first applied to the PI film and then a conventional silicone layer is applied. The specific component contents in the primer formula are: Dow Corning 7499: 95.69 parts by weight; Dow Corning 7028: 1.91 parts by weight; Dow Corning 9250: 0.96 parts by weight; Dow Corning 4000: 1.44 parts by weight; the specific component contents in the conventional silicone layer are: Dow Corning 7657: 48.54 parts by weight, Dow Corning 7647: 48.54 parts by weight, Dow Corning 7028: 1.46 parts by weight, and Dow Corning 4000: 1.46 parts by weight.

[0187] Comparative Example 2

[0188] Comparative Example 2: A silicone protective film was prepared using a conventional formulation in the art. The silicone film layer was replaced with a 25 μm thick PI film, and a conventional silicone layer was directly coated on the PI film. The specific contents of the conventional silicone film were: Dow Corning 7657: 48.08 parts by weight, Dow Corning 7647: 48.08 parts by weight, Dow Corning 7028: 1.44 parts by weight, Dow Corning 297: 0.96 parts by weight, and Dow Corning 4000: 1.44 parts by weight.

[0189] Comparative Example 3

[0190] Comparative Example 3 is basically the same as Comparative Example 1, except that the PI film is replaced by a PET film having a thickness of 25 μm.

[0191] Comparative Example 4

[0192] Comparative Example 4 is basically the same as Comparative Example 2, except that the PI film is replaced by a PET film having a thickness of 25 μm.

[0193] Test example:

[0194] The silicone protective films prepared in the examples and comparative examples were tested according to the following standards:

[0195] The total thickness of the silicone film layer and the protective film is tested using a thousandths display thickness gauge in accordance with GB / T7125-1999.

[0196] The hardness test method is to use a Shore hardness tester to test, referring to GB / T 2411-2008.

[0197] The transparency test method refers to ASTM D1003.

[0198] The tensile strength and elongation at break were tested using a universal material testing machine in accordance with GB / T30776-2014.

[0199] The steel plate peeling force test is carried out using a peeling force tester, referring to GB / T 2792-2014.

[0200] The high-temperature dimensional stability test method is to cut the product into L×W=100×100mm size and laminate it to plain glass at 200℃ for 2h, put it into the oven, take it out after 2h, and let it stand at room temperature for 30 minutes to observe the appearance changes. At the same time, the change rate of length and width is tested.

[0201] Test the haze change of the adhered glass. Test the pollution performance of the adhered object under high and low temperature conditions: adhere to plain glass, place it in high and low temperature environment for 72 hours, and test the change rate of light transmittance and haze of the adhered glass.

[0202] Pollution performance test: stick to plain glass, let it stand at room temperature for 72 hours, use a standard light box D65 light source, and check whether there is obvious foreign matter precipitation on the surface of the object.

[0203] Aging resistance test, aging resistance test under D85 / 72H conditions: stick plain glass, place it in the environment for 72 hours, remove the protective cover and observe whether there is any residual glue or debonding on the glass surface, and whether the force of removing it is obviously increased.

[0204] The performance test results of the protective films prepared in Examples 1-6 of the present invention and Comparative Examples 1-4 are shown in Table 1.

[0205] Table 1

[0206]

[0207]

[0208] As can be seen from Table 1, the protective film prepared in the embodiment of the present invention improves the performance of the silicone protective film and has good dimensional stability at high temperatures.

[0209] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A high temperature resistant and low shrinkage silicone protective film, characterized in that: It comprises a silicone film layer, an organic silicone pressure-sensitive adhesive layer and an isolation film layer, wherein the organic silicone pressure-sensitive adhesive layer is located on at least one surface of the silicone film layer, and the isolation film layer is located on the surface of the organic silicone pressure-sensitive adhesive layer away from the silicone film layer; The silicone membrane layer is composed of the following components: 40-70 parts by weight of methyl vinyl MQ resin, 10-50 parts by weight of vinyl silicone rubber, 10-50 parts by weight of phenyl vinyl silicone oil, 1-2.5 parts by weight of a cross-linking agent, 0.5-1 parts by weight of an inhibitor, and 1-2.5 parts by weight of a catalyst, wherein the ratio of M:Q in the methyl vinyl MQ resin is (1-1.4):1; The organic silicone pressure-sensitive adhesive layer is composed of the following components: 0.5-40 parts by weight of methyl MQ resin, 60-80 parts by weight of phenyl vinyl silicone oil, 0.1-2 parts by weight of acrylic modified silicone resin, 0.1-1 parts by weight of photoinitiator, 1-2 parts by weight of crosslinking agent, 0.5-1 parts by weight of inhibitor and 1-2.5 parts by weight of catalyst. The M:Q ratio in the methyl MQ resin is (0.6-0.9):

1.

2. The silicone protective film according to claim 1, wherein: The viscosity of the phenyl vinyl silicone oil is 500-1000 mPas, the relative molar content of phenyl in the phenyl vinyl silicone oil is 6-10%, and the relative molar content of vinyl in the phenyl vinyl silicone oil is 0.2-0.5%.

3. The silicone protective film according to claim 1, wherein: The molecular weight of the vinyl silicone rubber is 300,000-700,000.

4. The silicone protective film according to claim 1, wherein: The thickness of the silica gel film layer is 5-200 μm.

5. The silicone protective film according to claim 1, wherein: The cross-linking agent is one or more of phenyl hydrogen-containing silicone oil, methyl hydrogen-containing silicone oil, and terminal hydroxyl hydrogen-containing silicone oil.

6. The silicone protective film according to claim 1, wherein: The inhibitor is an alkynol compound.

7. The silicone protective film according to claim 6, wherein: The alkynol compound includes one or more of methylbutynol, acetylene cyclohexanol, phenylbutynol, and 3,5-dimethyl-1-hexyn-3-ol.

8. The silicone protective film according to claim 1, wherein: The catalyst is a Custer platinum catalyst.

9. The silicone protective film according to claim 1, characterized in that: The photoinitiator includes one or more of benzophenone, thioxanthone, anthraquinone and aromatic ketone compounds derivatives thereof.

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