Organic silicon pressure-sensitive adhesive as well as preparation method and application thereof

Abstract

The invention relates to an organic silicon pressure-sensitive adhesive as well as a preparation method and application thereof, and belongs to the field of pressure-sensitive adhesive materials. The organic silicon pressure-sensitive adhesive component comprises a main agent component, a cross-linking agent component, an anchoring agent component and a catalyst component; the main agent component comprises vinyl polysiloxane, high-temperature glue, MQ resin, an auxiliary agent I, an auxiliary agent II, a solvent I and an inhibitor; the auxiliary agent I is at least one of triethyl borate, tributyl borate, n-butyl borate, n-butyl zirconate and butyl titanate; the structural formula of the auxiliary agent II is shown as a formula 1, the general formula of a # imgabs0 # link structure in the structural formula 1 is shown as a formula 2, R1 is methyl, R2 is vinyl, and the ratio of n to m to q is (5-15): (10-30): (30-60); a protective film prepared from the organic silicon pressure-sensitive adhesive disclosed by the invention has relatively good aging stability and low mobility, the aging climbing of steel plate stripping force and film tearing force for attaching a hardened film is small, and the influence on the dynamic friction coefficient of the hardened film is small. # imgabs1 #

Description

Technical Field

[0001] The invention specifically relates to an organosilicon pressure-sensitive adhesive and a preparation method and application thereof, belonging to the field of pressure-sensitive adhesive materials. Background Art

[0002] In recent years, with the rapid development of domestic display technology, more and more electronic products have gradually entered the touch screen era, such as smart phones, tablet computers, car displays, etc. The touch screens of these products are in frequent contact with users, and are very prone to scratches, wear and stains after long-term use, which affects the display and touch effects. Replacing the screen is not only troublesome but also expensive.

[0003] To solve this problem, various screen protective films have emerged. These protective films are attached to the touch screen to prevent the touch screen from direct contact with the user, and have the effects of anti-scratch, anti-wear, and anti-stain, and basically do not affect the display and touch effects. When the protective film is scratched or worn, you only need to replace the protective film, which is convenient and cheap.

[0004] This type of screen protection film is generally a multi-layer composite structure, generally composed of a hardened layer upper protective film, a hardened layer, a base layer, a pressure-sensitive adhesive layer, etc. The hardened layer is in long-term contact with the user. The hardened layer provides high hardness and smoothness, making it scratch-resistant, wear-resistant, and stain-resistant. The silicone upper protective layer is mainly used to protect the hardened layer to prevent contamination and damage to the hardened layer during the production and transportation process.

[0005] There are two main problems with the existing silicone pressure-sensitive adhesive for the hardened layer and the upper protective film. One is that the tearing force between the upper protective layer and the hardened layer may be difficult to control and increase greatly after aging; the other is that silicon migration occurs after the upper protective layer and the hardened layer are bonded together, affecting the smoothness of the hardened film surface. Summary of the invention

[0006] In view of the above problems, the purpose of the present invention is to provide a low migration and low climb organosilicon pressure-sensitive adhesive for special films and a preparation method thereof, and to solve the above-mentioned problems by improving the vinyl content and structure of the high-temperature adhesive in the formula, the selection of low migration aid I, the synthesis of low climb aid II, and the structural design of the end-side hydrogen-containing silicone oil. The protective film prepared by the obtained organosilicon pressure-sensitive adhesive has a tearing force of 0.5-4g / 25mm on the hardened film, and the climb is less than 20% after aging at 150℃ for 3min; the 180° peeling force on the steel plate is 0.5-5g / 25mm, and the climb is less than 10% after aging at 150℃ for 3min; after the hardened film is bonded, aging at 150℃ for 3min has no effect on the dynamic friction coefficient of the hardened film (that is, no effect on the smooth effect).

[0007] In order to solve the above technical problems, the present invention adopts the following technical scheme: an organic silicone pressure-sensitive adhesive, the components include a main agent component, a cross-linking agent component, an anchoring agent component and a catalyst component; the main agent component includes: 60 to 140 parts by weight of vinyl polysiloxane, 5 to 40 parts by weight of high-temperature glue, 0 to 10 parts by weight of MQ resin, 0.5 to 2 parts by weight of auxiliary agent I, 1 to 4 parts by weight of auxiliary agent II, 40 to 80 parts by weight of solvent I and 0.5 to 1 part by weight of inhibitor;

[0008] The auxiliary agent I is at least one of triethyl borate, tributyl borate, n-butyl borate, n-butyl zirconate, and butyl titanate;

[0009] The structural formula of the auxiliary agent II is shown in Formula 1. The general formula of the linking structure is shown in Formula 2, wherein R1 is a methyl group, R2 is a vinyl group, and n:m:q=5-15:10-30:30-60;

[0010]

[0011] In one embodiment, the vinyl polysiloxane is a vinyl-terminated polysiloxane; preferably, the vinyl content is 0.05-0.2%, and the viscosity is 10000-100000 mPa·s. More preferably, the vinyl content is 0.06-0.12%, and the viscosity is 20000-80000 mPa·s.

[0012] In one embodiment: the high temperature adhesive is methyl vinyl silicone rubber; preferably, the methyl vinyl silicone rubber is methyl vinyl silicone rubber containing terminal vinyl groups, and the molecular weight of the high temperature adhesive is 500,000 to 650,000; more preferably, the high temperature adhesive is composed of 0.5 to 5wt% of a high temperature adhesive having a vinyl content of 0.5 to 3.5wt% and 95 to 99.5wt% of a high temperature adhesive having a vinyl content of 0.03 to 0.2wt%.

[0013] In one embodiment: the MQ resin is a methyl MQ resin; preferably, the M / Q ratio of the MQ resin is 0.7 to 1.1, and the weight average molecular weight is 3000 to 8000;

[0014] The solvent I is at least one of toluene, ethyl acetate, xylene, butanone or solvent gasoline;

[0015] The inhibitor is at least one of methyl butynol, ethynyl cyclohexanol, dimethyl hexynol, dimethyl heptynol, diphenyl propynol or methyl dodecynol.

[0016] In one embodiment: the preparation of the main agent comprises the following steps: mixing vinyl polysiloxane, high temperature glue, MQ resin, and solvent I at 70-110° C. for 3-4 hours, cooling to below 50° C., adding auxiliary agent I, auxiliary agent II, and inhibitor, and mixing for 2-3 hours to obtain the main agent.

[0017] In one embodiment: the proportion of each component in the organic silicone pressure-sensitive adhesive is: 100 parts by weight of the main agent, 0.8 to 1.5 parts by weight of the cross-linking agent, 0.8 to 1.2 parts by weight of the anchoring agent, and 1.0 to 2.0 parts by weight of the catalyst;

[0018] Preferably, the anchoring agent component is at least one of a siloxane containing a hydrogen group and an epoxy functional group and a siloxane containing a hydrogen group and an ether functional group; more preferably: the anchoring agent component is selected from the substances represented by the following structural formula:

[0019] Wherein R1, R2 are methyl or epoxy or epoxy-containing groups, R3 is epoxy or epoxy-containing groups, 2≤x≤6, 4≤y≤24, 2≤z≤8;

[0020] Preferably, the catalyst component is a platinum catalyst with a platinum content of 4000 to 6000 ppm.

[0021] In one embodiment: the cross-linking agent is a terminal hydrogen-based polysiloxane with a hydrogen content of 1.1 to 1.6 wt%; preferably, the terminal hydrogen-based polysiloxane is prepared by a balancing reaction between a terminal hydrogen-based polysiloxane with a hydrogen content of 1.0 to 1.6 wt% and a side hydrogen-based polysiloxane with a hydrogen content of 1.3 to 1.6 wt%; more preferably, the preparation method of the cross-linking agent is: by weight ratio, 40 to 90 parts by weight of a side hydrogen-based polysiloxane with a hydrogen content of 1.3 to 1.6 wt%, 5 to 10 parts by weight of a terminal hydrogen-based polysiloxane with a hydrogen content of 1.0 to 1.6 wt%, and 5 to 10 parts by weight of a cationic resin are mixed, balanced at 50 to 70° C. for 3 to 4 hours, and filtered to obtain the desired cross-linking agent.

[0022] The second technical problem solved by the present invention is to provide a method for preparing an organosilicon pressure-sensitive adhesive.

[0023] The preparation method of an organic silicon pressure-sensitive adhesive comprises the following steps: taking 100 parts by weight of a main agent, adding 100 to 300 parts by weight of a solvent II for dilution, then adding 0.8 to 1.5 parts by weight of a cross-linking agent component, and mixing for 5 to 10 minutes; then adding 0.8 to 1.2 parts by weight of an anchoring agent component, and mixing for 5 to 10 minutes; finally adding 1.0 to 2.0 parts by weight of a catalyst component, and mixing for 10 to 30 minutes, so as to obtain the organic silicon pressure-sensitive adhesive; preferably, the solvent II is at least one of ethyl acetate, toluene, xylene, butanone, and solvent gasoline.

[0024] The third technical problem solved by the present invention is to provide an application of an organic silicone pressure-sensitive adhesive.

[0025] The application of the organosilicon pressure-sensitive adhesive in a protective film; preferably, the protective film is a protective film on the upper layer of a hardening film or a protective film on the upper layer of a self-repairing layer.

[0026] In a specific application, a protective film on the upper layer of a hardened film, the preparation method of the protective film comprises the following steps: uniformly coating the silicone pressure-sensitive adhesive described in any one of claims 1 to 7 or the silicone pressure-sensitive adhesive prepared by the preparation method described in claim 8 on a substrate, and then curing the substrate coated with the silicone pressure-sensitive adhesive at 130 to 160°C for 2 to 3 minutes, taking it out and attaching it to the upper layer of the hardened film to form the protective film on the upper layer of the hardened film; preferably, the substrate is a PET film; preferably, the dry adhesive thickness after the pressure-sensitive adhesive layer is coated and cured on the substrate is 5 to 20 μm.

[0027] Compared with conventional addition-type organosilicon pressure-sensitive adhesive, the present invention has the following beneficial effects:

[0028] 1. This method selects the vinyl content and structure of the high-temperature adhesive. A high-temperature adhesive with a high vinyl content and an end-side vinyl structure is used in the system. The low vinyl content helps to improve the peeling force and adsorption of the protective film and the hardening film, while the high vinyl content can effectively reduce the tearing force of the protective film and the hardening film after high-temperature aging and improve the aging stability.

[0029] 2. This method has specially designed the structure of hydrogen-containing polysiloxane as the crosslinking agent component, and uses high-hydrogen-content terminal hydrogen-containing polysiloxane and high-hydrogen-content side hydrogen-containing polysiloxane for equilibrium reaction, and obtains terminal and side hydrogen-containing polysiloxanes with different structures by controlling the ratio of the two. The terminal and side hydrogen-containing polysiloxane synthesized by this method has the advantages of high reaction speed and high reaction degree. Using it as a crosslinking agent can not only increase the curing speed of the system, but also help control the aging climb, thereby solving the aging climb problem of protective film attached to hardened film and protective film attached to steel plate.

[0030] 3. This method specially introduces the additive I, the main function of which is to prevent the silicon migration phenomenon from occurring after the protective film and the hardened film are bonded together, which affects the smoothness of the hardened film surface. Specifically, after the protective film produced by conventional pressure-sensitive adhesive is bonded to the hardened film and aged, the dynamic friction coefficient of the hardened film surface increases from 0.1 to 0.3-0.5; after the protective film produced by this method is bonded to the hardened film and aged, the dynamic friction coefficient of the hardened film surface is still less than 0.1.

[0031] 4. This method designs and synthesizes auxiliary agent II, which effectively improves the high-temperature aging stability of film tearing force and steel plate peeling force through unique T-link structure design and control of phenyl and vinyl content, and reduces the aging climb of film tearing force and steel plate peeling force. DETAILED DESCRIPTION

[0032] The silicone pressure-sensitive adhesive comprises a main agent component, a cross-linking agent component, an anchoring agent component and a catalyst component; the main agent component comprises: 60 to 140 parts by weight of vinyl polysiloxane, 5 to 40 parts by weight of high-temperature adhesive, 0 to 10 parts by weight of MQ resin, 0.5 to 2 parts by weight of auxiliary agent I, 1 to 4 parts by weight of auxiliary agent II, 40 to 80 parts by weight of solvent I and 0.5 to 1 part by weight of inhibitor;

[0033] The auxiliary agent I is at least one of triethyl borate, tributyl borate, n-butyl borate, n-butyl zirconate, and butyl titanate;

[0034] The structural formula of the auxiliary agent II is shown in Formula 1. The general formula of the linking structure is shown in Formula 2, wherein R1 is a methyl group, R2 is a vinyl group, and n:m:q=5-15:10-30:30-60;

[0035]

[0036] After a large number of experiments, it was found that Additive II can effectively reduce the aging increase of film tearing force and steel plate peeling force through its unique T-link structure design and control of methyl and vinyl content. Additive I can maintain the smoothness of the hardened film surface and avoid an increase in the dynamic friction coefficient of the hardened film.

[0037] The preparation method of the auxiliary agent II of the present invention is as follows: 10 to 30 parts of phenyl polytrimethylsiloxane, 10 to 30 parts of methylphenyl mixed ring body, 5 to 15 parts of tetramethyl tetravinyl cyclotetrasiloxane and 25 to 45 parts of octamethyl cyclotetrasiloxane are added into a reaction kettle, heated and stirred until the temperature reaches 80 to 90° C., 1.8 to 4 parts of ammonium hydroxide silicon alkoxide catalyst are added, the temperature is continuously raised to 105 to 115° C., and constant temperature balance is performed for 6 to 7 hours; after the balance is completed, the stirring is stopped, the temperature is raised to 150° C. and the medium is broken for 30 to 40 minutes; after the medium is broken, the temperature is raised to 170 to 180° C. and vacuum degassing is performed for 4 to 8 hours to remove small molecular substances, and the obtained product is the auxiliary agent II.

[0038] Preferably, the vinyl polysiloxane is a vinyl-terminated polysiloxane; preferably, the vinyl content is 0.05 to 0.2%, and the viscosity is 10,000 to 100,000 mPa·s.

[0039] Preferably, the high temperature adhesive is methyl vinyl silicone rubber; preferably, the methyl vinyl silicone rubber is methyl vinyl silicone rubber containing terminal vinyl groups, and the molecular weight of the high temperature adhesive is 500,000 to 650,000; preferably, the high temperature adhesive is composed of 0.5 to 5wt% of a high temperature adhesive having a vinyl content of 0.5 to 3.5wt% and 95 to 99.5wt% of a high temperature adhesive having a vinyl content of 0.03 to 0.2wt%.

[0040] Preferably, the MQ resin is a methyl MQ resin; preferably, the M / Q ratio of the MQ resin is 0.7 to 1.1, and the weight average molecular weight is 3000 to 8000;

[0041] The solvent I is at least one of toluene, ethyl acetate, xylene, butanone and solvent gasoline;

[0042] The inhibitor is at least one of methyl butynol, ethynyl cyclohexanol, dimethyl hexynol, dimethyl heptynol, diphenyl propynol and methyl dodecynol.

[0043] Preferably, the preparation of the main agent comprises the following steps: mixing vinyl polysiloxane, high temperature glue, MQ resin, and solvent I at 70-110° C. for 3-4 hours, cooling to below 50° C., adding auxiliary agent I, auxiliary agent II, and inhibitor, and mixing for 2-3 hours to obtain the main agent.

[0044] Preferably, the proportions of the components in the organic silicone pressure-sensitive adhesive are: 100 parts by weight of the main agent, 0.8 to 1.5 parts by weight of the cross-linking agent, 0.8 to 1.2 parts by weight of the anchoring agent, and 1.0 to 2.0 parts by weight of the catalyst;

[0045] Preferably, the anchoring agent component is a siloxane containing a hydrogen group and an epoxy functional group, or a siloxane containing a hydrogen group and an ether functional group; more preferably: the anchoring agent component is selected from the substances represented by the following structural formula:

[0046] Wherein R1, R2 are methyl or epoxy or epoxy-containing groups, R3 is epoxy or epoxy-containing groups, 2≤x≤6, 4≤y≤24, 2≤z≤8;

[0047] Preferably, the catalyst component is a platinum catalyst with a platinum content of 4000 to 6000 ppm.

[0048] Preferably, the crosslinking agent is a terminal hydrogen-based polysiloxane having a hydrogen content of 1.1 to 1.6 wt%; preferably, the terminal hydrogen-based polysiloxane is prepared by a balancing reaction between a terminal hydrogen-based polysiloxane having a hydrogen content of 1.0 to 1.6 wt% and a side hydrogen-based polysiloxane having a hydrogen content of 1.3 to 1.6 wt%; more preferably, the preparation method of the crosslinking agent is as follows: by weight ratio, 40 to 90 parts by weight of a side hydrogen-based polysiloxane having a hydrogen content of 1.3 to 1.6 wt%, 5 to 10 parts by weight of a terminal hydrogen-based polysiloxane having a hydrogen content of 1.0 to 1.6 wt%, and 5 to 10 parts by weight of a cationic resin are mixed, balanced at 50 to 70° C. for 3 to 4 hours, and filtered to obtain the desired crosslinking agent.

[0049] The preparation method of an organic silicon pressure-sensitive adhesive comprises the following steps: taking 100 parts by weight of a main agent, adding 100 to 300 parts by weight of a solvent II for dilution, then adding 0.8 to 1.5 parts by weight of a cross-linking agent component, and mixing for 5 to 10 minutes; then adding 0.8 to 1.2 parts by weight of an anchoring agent component, and mixing for 5 to 10 minutes; finally adding 1.0 to 2.0 parts by weight of a catalyst component, and mixing for 10 to 30 minutes, so as to obtain the organic silicon pressure-sensitive adhesive; preferably, the solvent II is at least one of ethyl acetate, toluene, xylene, butanone, and solvent gasoline.

[0050] The organic silicon pressure-sensitive adhesive prepared by the invention is used in the upper protective film of the hardening film and the upper protective film of the self-repairing layer.

[0051] The invention also provides a method for preparing a protective film on the upper layer of the hardening film.

[0052] A protective film on a hardened film, wherein the preparation method of the protective film comprises the following steps:

[0053] (1) Preparation of the main agent: 60-140 parts by weight of vinyl polysiloxane, 5-40 parts by weight of high temperature glue, 0-10 parts by weight of MQ resin, and 40-80 parts by weight of solvent are placed in a reaction kettle, stirred for 3-4 hours at 70-110° C. to mix evenly, cooled to below 50° C., added with 0.5-2 parts by weight of auxiliary agent I, 1-4 parts by weight of auxiliary agent II, and 0.5-1 parts by weight of inhibitor, and stirred for 2-3 hours to mix evenly.

[0054] (2) Preparation of a crosslinking agent: 40 to 90 parts by weight of a pendant hydrogen polysiloxane having a hydrogen content of 1.3 to 1.6 wt%, 5 to 10 parts by weight of a terminal hydrogen polysiloxane having a hydrogen content of 1.0 to 1.6 wt%, and 5 to 10 parts by weight of a cationic resin are mixed uniformly, balanced at 50 to 70° C. for 3 to 4 hours, and filtered to obtain the desired crosslinking agent.

[0055] (3) Preparing a pressure-sensitive adhesive: Take 100 parts by weight of a main agent, add 100 to 300 parts by weight of a solvent to dilute, stir evenly, add 0.8 to 1.5 parts by weight of a cross-linking agent component under slow stirring, stir for 5 to 10 minutes; then add 0.8 to 1.2 parts by weight of an anchoring agent component, stir for 5 to 10 minutes; finally, add 1.0 to 2.0 parts by weight of a catalyst component, stir for 10 to 30 minutes, and the pressure-sensitive adhesive is obtained.

[0056] (4) Pressure-sensitive adhesive coating and curing: The pressure-sensitive adhesive liquid obtained above is uniformly coated on the substrate, and then the substrate coated with the adhesive liquid is cured at 130-160° C. for 2-3 minutes. After being taken out, it is attached to the upper layer of the hardened film to form a protective film on the hardened film.

[0057] Furthermore, the solvent in the above step (2) is at least one of ethyl acetate, toluene, xylene, and solvent gasoline;

[0058] Further, the substrate is a PET film;

[0059] Furthermore, the thickness of the dry adhesive after the pressure-sensitive adhesive layer is coated and cured on the substrate is 5 to 20 μm;

[0060] Furthermore, the upper layer of the hardened film is the hardened coating surface of the uppermost layer of the screen protection film.

[0061] Furthermore, the tearing force of the protective film on the hardened film is 0.5-4 g / 25 mm, and the tearing force after aging at 150° C. for 3 min increases by less than 20%;

[0062] Furthermore, the 180° peeling force of the upper protective film of the hardened film to the steel plate is 0.5-5 g / 25 mm, and the peeling force after aging at 150° C. for 3 minutes increases by less than 10%.

[0063] Furthermore, the low mobility is measured by a dynamic friction coefficient instrument to characterize the effect of the protective film on the slippery effect of the hardening film;

[0064] Furthermore, the dynamic friction coefficient of the hardened film before being attached to the protective film is measured to be less than 0.1;

[0065] Furthermore, after the hardened film was attached to the protective film, it was aged at 150°C for 3 minutes, the protective film was torn off, and the dynamic friction coefficient of the hardened film was tested to be still less than 0.1.

[0066] The above contents of the present invention are further described in detail below through the specific implementation methods of the embodiments. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples. Various substitutions or changes made according to common technical knowledge and customary means in the art without departing from the above technical concept of the present invention should be included in the scope of the present invention.

[0067] The low migration property of the present invention is measured by a dynamic friction coefficient meter to characterize the influence of the protective film on the smooth effect of the hardened film.

[0068] The preparation and application methods of the organosilicon pressure-sensitive adhesive in the present invention are described in detail below through specific examples. Each example is described by taking the organosilicon pressure-sensitive adhesive including a main agent component, a crosslinking agent component, an anchoring agent component and a catalyst component as an example. In each example, unless otherwise specified, all parts are by weight. Among them, the high-temperature adhesive is 110-0, 110-2, 110-6, 110-7, etc. produced by Dongjue Silicone, the vinyl polysiloxane is the terminal vinyl polysiloxane produced by Tuoli Technology, the anchoring agent is TB-303 produced by Tuoli Technology, and the catalyst is Heraeus Pt-5000, all of which are commercially available products.

[0069] Example 1

[0070] (1) Preparation of auxiliary agent II: 25.4 parts of phenyl polytrimethylsiloxane, 20.7 parts of methylphenyl mixed ring, 10 parts of tetramethyltetravinylcyclotetrasiloxane, and 41.5 parts of octamethylcyclotetrasiloxane were added to a reaction kettle, heated and stirred until the temperature reached 85°C, 1.8 parts of ammonium hydroxide silicon alkoxide catalyst were added, and the temperature was continued to be raised to 110°C and kept at a constant temperature for 6 hours; after the balance was completed, stirring was stopped, the temperature was raised to 150°C for 30 minutes to break the catalyst; after the catalyst was broken, the temperature was raised to 175°C for 6 hours to remove small molecules, and auxiliary agent II was obtained.

[0071] (2) Preparation of the main agent: Add 130 parts of vinyl polysiloxane with a vinyl content of 0.08wt% and a viscosity of 43000mPa·s, 30 parts of high-temperature glue (including 1.5 parts of 110-7 high-temperature glue with a vinyl content of 3.3wt% and 29 parts of 110-2 high-temperature glue with a vinyl content of 0.16wt%), 6 parts of MQ resin, and 60 parts of toluene into a reactor, stir at 90°C for 4h, cool to below 50°C, add 2 parts of n-butyl borate, 2 parts of auxiliary agent II and 0.5 parts of ethynyl cyclohexanol, and stir for another 2h to mix evenly.

[0072] (3) Preparation of a crosslinking agent: 50 parts of a pendant hydrogen polysiloxane having a hydrogen content of 1.6 wt%, 10 parts of a terminal hydrogen polysiloxane having a hydrogen content of 1.0 wt%, and 6 parts of a cationic resin are mixed evenly, balanced at 65° C. for 4 h, and filtered to obtain the desired crosslinking agent.

[0073] (4) Preparation of pressure-sensitive adhesive: Take 100 parts of the main agent, add 200 parts of ethyl acetate to dilute, stir evenly, add 1.0 part of the cross-linking agent component under slow stirring, stir for 10 minutes; then add 1.0 part of the anchoring agent component TB-303, stir for 10 minutes; finally, add 1.5 parts of the catalyst component Heraeus Pt-5000, stir for 20 minutes, and the pressure-sensitive adhesive is obtained.

[0074] (5) Pressure-sensitive adhesive coating and curing: The prepared pressure-sensitive adhesive liquid is evenly coated on the PET film with a coating thickness of 10 μm. The substrate coated with the adhesive liquid is then cured in an oven at 150°C for 2 minutes. After being taken out, it is attached to the upper layer of the hardened film to form a protective film on the hardened film.

[0075] (6) Performance test: Test the peeling force of the steel plate before and after the protective film is aged, the tearing force of the hardened film, and the change in the dynamic friction coefficient of the hardened film. The specific performance parameters are shown in Table 1.

[0076] Example 2

[0077] (1) Preparation of auxiliary agent II: same as in Example 1;

[0078] (2) Preparation of the main agent: Add 140 parts of vinyl polysiloxane with a vinyl content of 0.09wt% and a viscosity of 35000mPa·s, 20 parts of high-temperature glue (including 0.5 parts of 110-6 high-temperature glue with a vinyl content of 1.1wt% and 19.5 parts of 110-2 high-temperature glue with a vinyl content of 0.16wt%), 4 parts of MQ resin, and 50 parts of toluene into a reactor, stir at 110°C for 3h, cool to below 50°C, add 1.2 parts of butyl titanate, 1 part of auxiliary agent II and 1 part of methyl butynol, and stir for another 2h to mix evenly.

[0079] (3) Preparation of a crosslinking agent: 80 parts of a pendant hydrogen polysiloxane having a hydrogen content of 1.6 wt%, 5 parts of a terminal hydrogen polysiloxane having a hydrogen content of 1.3 wt%, and 8 parts of a cationic resin are mixed evenly, balanced at 60° C. for 4 h, and filtered to obtain the desired crosslinking agent.

[0080] (4) Preparation of pressure-sensitive adhesive: Take 100 parts of the main agent, add 150 parts of toluene to dilute, stir evenly, add 1.2 parts of the cross-linking agent component under slow stirring, stir for 10 minutes; then add 1.2 parts of the anchoring agent component TB-303, stir for 10 minutes; finally, add 1.5 parts of the catalyst component Heraeus Pt-5000, stir for 20 minutes, and the pressure-sensitive adhesive is obtained.

[0081] (5) Pressure-sensitive adhesive coating and curing: The prepared pressure-sensitive adhesive liquid is evenly coated on the PET film with a coating thickness of 15 μm. The substrate coated with the adhesive liquid is then cured in an oven at 160° C. for 2 minutes. After being taken out, it is attached to the upper layer of the hardened film to form a protective film on the hardened film.

[0082] (6) Performance test: Test the peeling force of the steel plate before and after the protective film is aged, the tearing force of the hardened film, and the change in the dynamic friction coefficient of the hardened film. The specific performance parameters are shown in Table 1.

[0083] Example 3

[0084] (1) Preparation of auxiliary agent II: same as in Example 1;

[0085] (2) Preparation of the main agent: Add 120 parts of vinyl polysiloxane with a vinyl content of 0.06wt% and a viscosity of 80000mPa·s, 40 parts of high-temperature glue (including 2 parts of 110-7 high-temperature glue with a vinyl content of 3.3wt% and 38 parts of 110-2 high-temperature glue with a vinyl content of 0.16wt%), 5 parts of MQ resin, and 40 parts of toluene into a reactor, stir at 100°C for 3h, cool to below 50°C, add 0.8 parts of n-butyl zirconate, 1.5 parts of auxiliary agent II and 0.5 parts of diphenylpropynol, and stir for another 2h to mix evenly.

[0086] (3) Preparation of a crosslinking agent: 90 parts of a pendant hydrogen polysiloxane having a hydrogen content of 1.5 wt%, 5 parts of a terminal hydrogen polysiloxane having a hydrogen content of 1.6 wt%, and 10 parts of a cationic resin are mixed evenly, balanced at 55° C. for 4 h, and filtered to obtain the desired crosslinking agent.

[0087] (4) Preparation of pressure-sensitive adhesive: Take 100 parts of the main agent, add 200 parts of xylene to dilute, stir evenly, add 0.9 parts of the cross-linking agent component under slow stirring, stir for 10 minutes; then add 1.0 parts of the anchoring agent component TB-303, stir for 10 minutes; finally, add 1.2 parts of the catalyst component Heraeus Pt-5000, stir for 20 minutes, and the pressure-sensitive adhesive is obtained.

[0088] (5) Pressure-sensitive adhesive coating and curing: The prepared pressure-sensitive adhesive liquid is evenly coated on the PET film with a coating thickness of 10 μm. The substrate coated with the adhesive liquid is then cured in an oven at 140°C for 2 minutes. After being taken out, it is attached to the upper layer of the hardened film to form a protective film on the hardened film.

[0089] (6) Performance test: Test the peeling force of the steel plate before and after the protective film is aged, the tearing force of the hardened film, and the change in the dynamic friction coefficient of the hardened film. The specific performance parameters are shown in Table 1.

[0090] Example 4

[0091] (1) Preparation of auxiliary agent II: same as in Example 1;

[0092] (2) Preparation of the main agent: Add 120 parts of vinyl polysiloxane with a vinyl content of 0.12wt% and a viscosity of 20000mPa·s, 40 parts of high temperature glue (including 2 parts of 110-7 high temperature glue with a vinyl content of 3.3wt% and 38 parts of 110-0 high temperature glue with a vinyl content of 0.04wt%), 3 parts of MQ resin, and 40 parts of toluene into a reactor, stir at 90°C for 3h, cool to below 50°C, add 0.6 parts of tributyl borate, 2.5 parts of auxiliary agent II and 1 part of dimethylheptynol, and stir for 2h to mix evenly.

[0093] (3) Preparation of a crosslinking agent: 90 parts of a pendant hydrogen polysiloxane having a hydrogen content of 1.4 wt%, 10 parts of a terminal hydrogen polysiloxane having a hydrogen content of 1.6 wt%, and 8 parts of a cationic resin are mixed evenly, balanced at 65° C. for 4 h, and filtered to obtain the desired crosslinking agent.

[0094] (4) Preparation of pressure-sensitive adhesive: Take 100 parts of the main agent, add 200 parts of ethyl acetate to dilute, stir evenly, add 1.2 parts of the cross-linking agent component under slow stirring, stir for 10 minutes; then add 1.0 parts of the anchoring agent component TB-303, stir for 10 minutes; finally, add 2.0 parts of the catalyst component Heraeus Pt-5000, stir for 20 minutes, and the pressure-sensitive adhesive is obtained.

[0095] (5) Pressure-sensitive adhesive coating and curing: The prepared pressure-sensitive adhesive liquid is evenly coated on the PET film with a coating thickness of 10 μm. The substrate coated with the adhesive liquid is then cured in an oven at 150°C for 2 minutes. After being taken out, it is attached to the upper layer of the hardened film to form a protective film on the hardened film.

[0096] (6) Performance test: Test the peeling force of the steel plate before and after the protective film is aged, the tearing force of the hardened film, and the change in the dynamic friction coefficient of the hardened film. The specific performance parameters are shown in Table 1.

[0097] Example 5 (without MQ resin)

[0098] (1) Preparation of auxiliary agent II: same as in Example 1;

[0099] (2) Preparation of the main agent: 120 parts of vinyl polysiloxane with a vinyl content of 0.12 wt% and a viscosity of 20,000 mPa·s, 40 parts of high-temperature glue (including 2 parts of 110-7 high-temperature glue with a vinyl content of 3.3 wt% and 38 parts of 110-0 high-temperature glue with a vinyl content of 0.04 wt%), and 40 parts of toluene were added into a reactor, stirred at 90° C. for 3 h, cooled to below 50° C., 0.6 parts of tributyl borate, 2.5 parts of auxiliary agent II, and 1 part of dimethylheptynol were added, and stirred for another 2 h to mix evenly.

[0100] (3) Preparation of a crosslinking agent: 90 parts of a pendant hydrogen polysiloxane having a hydrogen content of 1.6 wt%, 10 parts of a terminal hydrogen polysiloxane having a hydrogen content of 1.3 wt%, and 8 parts of a cationic resin are mixed evenly, balanced at 65° C. for 4 h, and filtered to obtain the desired crosslinking agent.

[0101] (4) Preparation of pressure-sensitive adhesive: Take 100 parts of the main agent, add 200 parts of ethyl acetate to dilute, stir evenly, add 1.2 parts of the cross-linking agent component under slow stirring, stir for 10 minutes; then add 1.0 parts of the anchoring agent component TB-303, stir for 10 minutes; finally, add 2.0 parts of the catalyst component Heraeus Pt-5000, stir for 20 minutes, and the pressure-sensitive adhesive is obtained.

[0102] (5) Pressure-sensitive adhesive coating and curing: The prepared pressure-sensitive adhesive liquid is evenly coated on the PET film with a coating thickness of 10 μm. The substrate coated with the adhesive liquid is then cured in an oven at 150°C for 2 minutes. After being taken out, it is attached to the upper layer of the hardened film to form a protective film on the hardened film.

[0103] (6) Performance test: Test the peeling force of the steel plate before and after the protective film is aged, the tearing force of the hardened film, and the change in the dynamic friction coefficient of the hardened film. The specific performance parameters are shown in Table 1.

[0104] Comparative Example 1

[0105] (1) Preparation of the main agent: 120 parts of vinyl polysiloxane with a vinyl content of 0.12 wt% and a viscosity of 20,000 mPa·s, 40 parts of high temperature glue (including 2 parts of 110-7 high temperature glue with a vinyl content of 3.3 wt% and 38 parts of 110-0 high temperature glue with a vinyl content of 0.04 wt%), 3 parts of MQ resin, and 40 parts of toluene were added into a reactor, stirred at 90° C. for 3 h, cooled to below 50° C., 0.6 parts of tributyl borate and 1 part of dimethylheptynol were added, and stirred for another 2 h to mix evenly.

[0106] (2) Preparation of cross-linking agent: same as in Example 4

[0107] (3) Pressure-sensitive adhesive: same as in Example 4

[0108] (4) Pressure-sensitive adhesive coating and curing: same as in Example 4

[0109] (5) Performance test: Same as Example 4

[0110] Comparative Example 2

[0111] (1) Preparation of auxiliary agent II: same as in Example 1;

[0112] (2) Preparation of the main agent: Add 120 parts of vinyl polysiloxane with a vinyl content of 0.12wt% and a viscosity of 20000mPa·s, 40 parts of high-temperature glue (including 2 parts of 110-7 high-temperature glue with a vinyl content of 3.3wt% and 38 parts of 110-0 high-temperature glue with a vinyl content of 0.04wt%), 3 parts of MQ resin, and 40 parts of toluene into a reactor, stir at 90°C for 3h, cool to below 50°C, add 2.5 parts of auxiliary agent II and 1 part of dimethylheptynol, and stir for another 2h to mix evenly.

[0113] (3) Preparation of cross-linking agent: same as Example 4.

[0114] (4) Preparing pressure-sensitive adhesive: Same as in Example 4.

[0115] (5) Pressure-sensitive adhesive coating and curing: same as Example 4.

[0116] (6) Performance test: Same as Example 4.

[0117] Comparative Example 3

[0118] (1) Preparation of auxiliary agent II: same as in Example 1;

[0119] (2) Preparation of main agent: same as Example 4.

[0120] (3) Preparation of a crosslinking agent: 100 parts of pendant hydrogen polysiloxane with a hydrogen content of 1.6 wt% and 8 parts of a cationic resin were mixed evenly, reacted at 65° C. for 4 h, and filtered to obtain the desired crosslinking agent.

[0121] (4) Preparation of pressure-sensitive adhesive: same as the preparation method in Example 4.

[0122] (5) Pressure-sensitive adhesive coating and curing: same as Example 4.

[0123] (6) Performance test: Same as Example 4.

[0124] Comparative Example 4

[0125] (1) Preparation of auxiliary agent II: same as in Example 1;

[0126] (2) Preparation of main agent: same as Example 4.

[0127] (3) Preparation of a crosslinking agent: 100 parts of hydrogen-terminated polysiloxane having a hydrogen content of 1.6 wt% and 8 parts of a cationic resin are mixed evenly, reacted at 65° C. for 4 h, and filtered to obtain the desired crosslinking agent.

[0128] (4) Preparation of pressure-sensitive adhesive: same as the preparation method in Example 4.

[0129] (5) Pressure-sensitive adhesive coating and curing: same as Example 4.

[0130] (6) Performance test: Same as Example 4.

[0131] Comparative Example 5

[0132] (1) Preparation of auxiliary agent II: same as in Example 1;

[0133] (2) Preparation of the main agent: 120 parts of vinyl polysiloxane with a vinyl content of 0.12 wt% and a viscosity of 20,000 mPa·s, 40 parts of high-temperature glue (110-7 with a vinyl content of 3.3 wt%), 3 parts of MQ resin, and 40 parts of toluene were added into a reactor, stirred at 90°C for 3 h, cooled to below 50°C, 0.6 parts of tributyl borate, 2.5 parts of auxiliary agent II, and 1 part of dimethylheptynol were added, and stirred for another 2 h to mix evenly.

[0134] (3) Preparation of cross-linking agent: same as in Example 4

[0135] (4) Preparation of pressure-sensitive adhesive: same as the preparation method in Example 4.

[0136] (5) Pressure-sensitive adhesive coating and curing: same as Example 4.

[0137] (6) Performance test: Same as Example 4.

[0138] Comparative Example 6

[0139] (1) Preparation of auxiliary agent II: same as in Example 1;

[0140] (2) Preparation of the main agent: 120 parts of vinyl polysiloxane with a vinyl content of 0.12 wt% and a viscosity of 20,000 mPa·s, 40 parts of high-temperature glue (110-0 with a vinyl content of 0.04 wt%), 3 parts of MQ resin, and 40 parts of toluene were added into a reactor, stirred at 90° C. for 3 h, cooled to below 50° C., 0.6 parts of tributyl borate, 2.5 parts of auxiliary agent II, and 1 part of dimethylheptynol were added, and stirred for another 2 h to mix evenly.

[0141] (3) Preparation of cross-linking agent: same as in Example 4

[0142] (4) Preparation of pressure-sensitive adhesive: same as the preparation method in Example 4.

[0143] (5) Pressure-sensitive adhesive coating and curing: same as Example 4.

[0144] (6) Performance test: Same as Example 4.

[0145] Table 1 Example Comparative Examples Performance Test Results

[0146]

[0147] The performance test standards and methods of the above-mentioned silicone pressure-sensitive adhesive are as follows:

[0148] Steel plate peeling force: refer to the test method of 180° peeling strength in GB / T2792, and select mirror steel plate as the test plate.

[0149] Tear force of hardened film: According to GB / T2792, a mirror steel plate is selected as the test plate, double-sided tape is pasted on the mirror steel plate, and the isolation layer on the double-sided tape is torn off. According to GB / T2792, a sample is prepared, and the back of the hardened film of the sample is pasted on the mirror steel plate with double-sided tape. According to the 180° peel strength test method in GB / T2792, the protective film on the surface of the hardened film is torn off. The force obtained is the tear force of the hardened film.

[0150] Dynamic friction coefficient of hardened film: refer to the determination method of dynamic friction coefficient in GB / T10006.

[0151] Aging test method: After the protective film and the hardening film are bonded together, place them in a 150°C oven for aging for 3 minutes, and then test the steel plate peeling force, the hardening film tearing force, the hardening film dynamic friction coefficient and other indicators.

[0152] Aging stability calculation method: (data after aging - data before aging) / data before aging * 100%.

[0153] It can be seen from the data of Examples 1 to 5 in the table that within the specified range of the present invention, the steel plate peeling force, the hardened film tearing force and the hardened film dynamic friction coefficient can all meet the index requirements, the aging performance is stable, the steel plate peeling force increases by less than 10%, the hardened film tearing force increases by less than 20%, the hardened film dynamic friction coefficient is less than 0.1, and the hardened film surface smoothness effect is not affected.

[0154] It can be seen from the data of the embodiments and comparative examples in the table that, compared with Example 4, only the cross-linking agent component was replaced in Comparative Examples 3 and 4, and the aging performance stability was significantly deteriorated, and the steel plate peeling force and the hardened film tearing force both increased significantly. Compared with Example 4, only the auxiliary agent II was cancelled in Comparative Example 1, and the steel plate peeling force and the hardened film tearing force increased significantly after aging, and the aging stability was poor. Compared with Example 4, only the auxiliary agent I was cancelled in Comparative Example 2, and the dynamic friction coefficient of the hardened film increased significantly, which had a serious impact on the smoothness of the hardened film surface. Compared with Example 4, the high-temperature adhesive in Comparative Examples 5 and 6 used a single structure, and the initial tearing force and peeling force changed greatly, and the aging stability deteriorated.

Claims

1. Organic silicon pressure-sensitive adhesive, characterized in that: The components include a main agent component, a cross-linking agent component, an anchoring agent component and a catalyst component; The main agent components include: 60-140 parts by weight of vinyl polysiloxane, 5-40 parts by weight of high temperature glue, 0-10 parts by weight of MQ resin, 0.5-2 parts by weight of auxiliary agent I, 1-4 parts by weight of auxiliary agent II, 40-80 parts by weight of solvent I and 0.5-1 part by weight of inhibitor; The auxiliary agent I is at least one of triethyl borate, tributyl borate, n-butyl borate, n-butyl zirconate or butyl titanate; The structural formula of the auxiliary agent II is shown in Formula 1. The general formula of the linking structure is shown in Formula 2, wherein R1 is a methyl group, R2 is a vinyl group, and n:m:q=5-15:10-30:30-60; 2. The organic silicone pressure-sensitive adhesive according to claim 1, characterized in that: The vinyl polysiloxane is a vinyl-terminated polysiloxane; preferably, the vinyl content is 0.05-0.2%, and the viscosity is 10000-100000 mPa·s; more preferably, the vinyl content is 0.06-0.12%, and the viscosity is 20000-80000 mPa·s.

3. The organic silicone pressure-sensitive adhesive according to claim 1, characterized in that: The high temperature adhesive is methyl vinyl silicone rubber; preferably, the methyl vinyl silicone rubber is methyl vinyl silicone rubber containing terminal vinyl groups, and the molecular weight of the high temperature adhesive is 500,000 to 650,000; more preferably, the high temperature adhesive is composed of 0.5 to 5wt% of a high temperature adhesive having a vinyl content of 0.5 to 3.5wt% and 95 to 99.5wt% of a high temperature adhesive having a vinyl content of 0.03 to 0.2wt%.

4. The organic silicone pressure-sensitive adhesive according to claim 1, characterized in that: The MQ resin is a methyl MQ resin; preferably, the M / Q ratio of the MQ resin is 0.7 to 1.1, and the weight average molecular weight is 3000 to 8000; The solvent I is at least one of toluene, ethyl acetate, xylene, butanone or solvent gasoline; The inhibitor is at least one of methyl butynol, ethynyl cyclohexanol, dimethyl hexynol, dimethyl heptynol, diphenyl propynol or methyl dodecynol.

5. The organic silicone pressure-sensitive adhesive according to any one of claims 1 to 4, characterized in that: The preparation of the main agent comprises the following steps: mixing vinyl polysiloxane, high temperature glue, MQ resin and solvent I at 70-110° C. for 3-4 hours, cooling to below 50° C., adding auxiliary agent I, auxiliary agent II and inhibitor, and mixing for 2-3 hours to obtain the main agent.

6. The organic silicone pressure-sensitive adhesive according to any one of claims 1 to 5, characterized in that: The proportions of the components in the organic silicone pressure-sensitive adhesive are: 100 parts by weight of the main agent, 0.8 to 1.5 parts by weight of the cross-linking agent, 0.8 to 1.2 parts by weight of the anchoring agent, and 1.0 to 2.0 parts by weight of the catalyst; Preferably, the anchoring agent component is at least one of a siloxane containing a hydrogen group and an epoxy functional group and a siloxane containing a hydrogen group and an ether functional group; more preferably: the anchoring agent component is selected from the substances represented by the following structural formula: Wherein R1, R2 are methyl or epoxy or epoxy-containing groups, R3 is epoxy or epoxy-containing groups, 2≤x≤6, 4≤y≤24, 2≤z≤8; Preferably, the catalyst component is a platinum catalyst with a platinum content of 4000 to 6000 ppm.

7. The organic silicone pressure-sensitive adhesive according to any one of claims 1 to 6, characterized in that: The cross-linking agent is a terminal hydrogen-based polysiloxane with a hydrogen content of 1.1 to 1.6 wt %; preferably, the terminal hydrogen-based polysiloxane is prepared by a balancing reaction between a terminal hydrogen-based polysiloxane with a hydrogen content of 1.0 to 1.6 wt % and a side hydrogen-based polysiloxane with a hydrogen content of 1.3 to 1.6 wt %; more preferably, the preparation method of the cross-linking agent is as follows: by weight ratio, 40 to 90 parts by weight of a side hydrogen-based polysiloxane with a hydrogen content of 1.3 to 1.6 wt %, 5 to 10 parts by weight of a terminal hydrogen-based polysiloxane with a hydrogen content of 1.0 to 1.6 wt %, and 5 to 10 parts by weight of a cationic resin are mixed, balanced at 50 to 70° C. for 3 to 4 hours, and filtered to obtain the desired cross-linking agent.

8. A method for preparing a silicone pressure-sensitive adhesive, characterized in that: The method comprises the following steps: taking 100 parts by weight of a main agent, adding 100 to 300 parts by weight of a solvent II for dilution, then adding 0.8 to 1.5 parts by weight of a crosslinking agent component, and mixing for 5 to 10 minutes; then adding 0.8 to 1.2 parts by weight of an anchoring agent component, and mixing for 5 to 10 minutes; and finally adding 1.0 to 2.0 parts by weight of a catalyst component, and mixing for 10 to 30 minutes, so as to prepare an organosilicon pressure-sensitive adhesive; preferably, the solvent II is at least one of ethyl acetate, toluene, xylene, butanone, and solvent gasoline.

9. Use of the organosilicon pressure-sensitive adhesive according to any one of claims 1 to 7 in a protective film; preferably, the protective film is a protective film on a hardened film or a protective film on a self-repairing layer.

10. A protective film on a hardened film, characterized in that: The preparation method of the protective film comprises the following steps: uniformly coating the organic silicone pressure-sensitive adhesive described in any one of claims 1 to 7 or the organic silicone pressure-sensitive adhesive prepared by the preparation method described in claim 8 on a substrate, curing the substrate coated with the organic silicone pressure-sensitive adhesive at 130 to 160° C. for 2 to 3 minutes, taking it out and attaching it to the upper layer of the hardened film to prepare a protective film on the upper layer of the hardened film; preferably, the substrate is a PET film; preferably, the thickness of the dry adhesive after the pressure-sensitive adhesive layer is coated and cured on the substrate is 5 to 20 μm.

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