Antistatic TAC high-transparency silicone protective film and preparation method thereof

Abstract

The present invention belongs to the technical field of protective films for electronic products, and specifically relates to an antistatic TAC high-transmittance silicone protective film and a preparation method thereof. The preparation method comprises the following steps: (1) adding TAC and an organic antistatic agent to an organic solvent to dissolve and degas to obtain a glue solution, and then forming the solution by casting and drying to obtain an antistatic TAC film; (2) coating the surface of the antistatic TAC film in step (1) with an organic silicone pressure-sensitive adhesive solution, and heating and drying and curing to obtain an organic silicone pressure-sensitive adhesive layer; (3) coating the surface of the organic silicone pressure-sensitive adhesive layer in step (2) with a release film layer to obtain an antistatic TAC high-transmittance silicone protective film. The antistatic TAC high-transmittance silicone protective film of the present invention is compounded with an antistatic TAC film and an organic silicone pressure-sensitive adhesive layer, and the obtained protective film has good transparency, antistatic performance, bonding performance and moisture and heat resistance stability.

Description

Technical Field

[0001] The invention belongs to the technical field of electronic product protective films, and specifically relates to an antistatic TAC high-transmittance silica gel protective film and a preparation method thereof. Background Art

[0002] With the rapid development of electronic products, supporting products related to electronic products have also been developed, including electronic product screens and related protective film products.

[0003] TAC (triacetate) film is a protective film material with excellent optical properties. It has the advantages of high transmittance and low refractive index and is widely used in the field of protective films for electronic products. However, TAC film is prone to static electricity, thermal deformation, high brittleness and poor bonding properties, which limits its application.

[0004] Patent application document CN 116102793 A discloses a cellulose triacetate film, whose raw materials include, by weight: 80-100 parts of cellulose acylate, 5-20 parts of plasticizer, 1-10 parts of toughening agent, 100-300 parts of solvent, 10-50 parts of alcohol with 1-4 carbon atoms, 0.1-3 parts of ultraviolet absorber, and 0.1-2 parts of matting agent. The cellulose triacetate film has excellent water resistance, durability and dimensional stability. The plasticizer and toughening agent have good compatibility with cellulose triacetate, which can greatly reduce precipitation, improve the appearance quality of the product, and its optical properties are more excellent. However, it does not solve the defects of TAC film that it is easy to generate static electricity and has poor bonding performance. Summary of the invention

[0005] In view of the shortcomings and deficiencies of the above prior art, the primary purpose of the present invention is to provide a method for preparing an antistatic TAC high-transmittance silicone protective film.

[0006] Another object of the present invention is to provide an antistatic TAC high-transmittance silicone protective film prepared by the above method.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] A method for preparing an antistatic TAC high-transmittance silicone protective film comprises the following preparation steps:

[0009] (1) adding triacetyl cellulose (TAC) and an organic antistatic agent into an organic solvent to dissolve and degas to obtain a glue solution, and then forming the solution by casting and drying to obtain an antistatic TAC film;

[0010] (2) coating the surface of the antistatic TAC film in step (1) with an organic silicone pressure-sensitive adhesive solution, and heating, drying and curing the solution to obtain an organic silicone pressure-sensitive adhesive layer;

[0011] (3) A release film layer is coated on the surface of the organic silicone pressure-sensitive adhesive layer in step (2) to obtain an antistatic TAC high-transmittance silicone protective film.

[0012] Furthermore, the organic antistatic agent in step (1) is preferably sodium cellulose sulfate, and the amount of the organic antistatic agent added is 0.5% to 3% of the mass of TAC. The use of sodium cellulose sulfate as an antistatic agent in the present invention has the advantages of good compatibility with TAC and high stability, and has little effect on the light transmittance of the TAC film.

[0013] Furthermore, the organic solvent in step (1) is preferably one or a mixed solvent of two or more selected from the group consisting of N-methylpyrrolidone (NMP), dimethylformamide (DMF), acetone and dichloromethane.

[0014] Furthermore, the antistatic TAC film in step (1) has a thickness of 10 to 100 μm.

[0015] Furthermore, the organic silicone pressure-sensitive adhesive solution in step (2) comprises vinyl polysiloxane, hydrogen-containing polysiloxane, vinyl silane coupling agent, isocyanate silane coupling agent, platinum catalyst, inhibitor and diluent solvent.

[0016] Further preferably, the molecular weight of the vinyl polysiloxane is 50,000 to 500,000, and the vinyl content is 0.2% to 10% (wt.%); the molecular weight of the hydrogen-containing polysiloxane is 5,000 to 50,000, and the hydrogen content is 0.2% to 1% (wt.%); the added amount of the hydrogen-containing polysiloxane is 5% to 50% of the mass of the vinyl polysiloxane.

[0017] Further preferably, the vinyl silane coupling agent is vinyl trimethoxy silane or vinyl triethoxy silane, and the amount of the vinyl silane coupling agent added is 1% to 5% of the mass of the vinyl polysiloxane; the isocyanate silane coupling agent is 3-isocyanate propyl trimethoxy silane or 3-isocyanate propyl triethoxy silane, and the amount of the isocyanate silane coupling agent added is 1% to 5% of the mass of the vinyl polysiloxane.

[0018] The present invention uses the synergistic effect of a vinyl silane coupling agent and an isocyanate silane coupling agent. The vinyl group contained in the vinyl silane coupling agent can participate in the addition crosslinking reaction of the vinyl polysiloxane and the hydrogen-containing polysiloxane. At the same time, the coupling group contained in the vinyl silane coupling agent can undergo a dealcoholization crosslinking reaction with the isocyanate silane coupling agent. Each component can form a good chemical connection to ensure that the organic silicon pressure-sensitive adhesive layer has good uniform performance. In addition, the isocyanate group introduced by the isocyanate silane coupling agent and the remaining coupling group can form a good chemical connection with the hydroxyl group on the surface of the TAC film, thereby significantly improving the bonding force between the organic silicon pressure-sensitive adhesive layer and the TAC film, and significantly improving its bonding composite stability.

[0019] Further preferably, the platinum catalyst is a polyvinylsiloxane-platinum complex, and the added amount of the platinum catalyst is 0.005% to 0.02% of the mass of the vinyl polysiloxane; the inhibitor is methyl butynol, acetylene cyclohexanol or 3,7,11-trimethyldodecene-3-ol, and the added amount of the inhibitor is 0.05% to 0.2% of the mass of the vinyl polysiloxane.

[0020] Further preferably, the dilution solvent is toluene, xylene, ethyl acetate, solvent gasoline or petroleum ether, and the added amount of the dilution solvent is 20% to 100% of the mass of the vinyl polysiloxane.

[0021] Furthermore, the thickness of the organic silicone pressure-sensitive adhesive layer in step (2) is 1 to 10 μm.

[0022] An antistatic TAC high-transmittance silica gel protective film is prepared by the method.

[0023] Furthermore, the light transmittance of the antistatic TAC high-transmittance silicone protective film is greater than 92%.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The antistatic TAC high-transmittance silicone protective film of the present invention is compounded by an antistatic TAC film and an organic silicone pressure-sensitive adhesive layer, and the resulting protective film has good transparency, antistatic performance, bonding performance and moisture and heat resistance stability.

[0026] (2) The present invention can significantly improve the bonding force between the silicone pressure-sensitive adhesive layer and the TAC film and enhance its bonding performance by rationally designing the composition of the silicone pressure-sensitive adhesive liquid. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0028] Example 1

[0029] A method for preparing an antistatic TAC high-transmittance silicone protective film comprises the following preparation steps:

[0030] (1) TAC and 2% (relative to the mass percentage of TAC) of sodium cellulose sulfate antistatic agent were added to DMF solvent for dissolution and degassing to obtain a glue solution with a solid content of 33%, which was then formed by casting and drying to obtain an antistatic TAC film with a thickness of 45 μm.

[0031] (2) coating the surface of the antistatic TAC film in step (1) with an organic silicone pressure-sensitive adhesive (the adhesive comprises, by weight, 100 parts of a vinyl polysiloxane having a molecular weight of 100,000 and a vinyl content of 4.0% (wt.%), 20 parts of a hydrogen-containing polysiloxane having a molecular weight of 10,000 and a hydrogen content of 0.5% (wt.%), 2 parts of vinyl trimethoxy silane, 3 parts of 3-isocyanate propyl triethoxy silane, 0.01 parts of a polyvinyl siloxane-platinum complex catalyst, 0.1 parts of an acetylene cyclohexanol inhibitor and 50 parts of a diluent solvent, toluene), heating to 80-90° C. and drying and curing for 2 hours to obtain an organic silicone pressure-sensitive adhesive layer having a thickness of 5 μm.

[0032] (3) A release film layer is coated on the surface of the organic silicone pressure-sensitive adhesive layer in step (2) to obtain an antistatic TAC high-transmittance silicone protective film.

[0033] The light transmittance of the obtained antistatic TAC high-transmittance silicone protective film was measured to be 93.2% (the measured data after removing the release film, the same below); the surface resistivity of the TAC film layer was 6.2×10 8 Ω; no debonding or cracking after being treated in a hot and humid environment of 80°C and 90% humidity for 48 hours; the peel strength value to the glass substrate is 8.3N / 25mm.

[0034] Example 2

[0035] A method for preparing an antistatic TAC high-transmittance silicone protective film comprises the following preparation steps:

[0036] (1) TAC and 0.5% (relative to the mass percentage of TAC) of sodium cellulose sulfate antistatic agent were added to DMF solvent for dissolution and degassing to obtain a glue solution with a solid content of 30%, which was then formed by casting and drying to obtain an antistatic TAC film with a thickness of 10 μm.

[0037] (2) coating the surface of the antistatic TAC film in step (1) with an organic silicone pressure-sensitive adhesive (the adhesive comprises, by weight, 100 parts of a vinyl polysiloxane having a molecular weight of 100,000 and a vinyl content of 4.0% (wt.%), 20 parts of a hydrogen-containing polysiloxane having a molecular weight of 10,000 and a hydrogen content of 0.5% (wt.%), 2 parts of vinyl trimethoxy silane, 3 parts of 3-isocyanate propyl triethoxy silane, 0.01 parts of a polyvinylsiloxane-platinum complex catalyst, 0.1 parts of an acetylene cyclohexanol inhibitor and 50 parts of a diluent solvent, toluene), heating to 80-90° C. and drying and curing for 2 hours to obtain an organic silicone pressure-sensitive adhesive layer having a thickness of 1 μm.

[0038] (3) A release film layer is coated on the surface of the organic silicone pressure-sensitive adhesive layer in step (2) to obtain an antistatic TAC high-transmittance silicone protective film.

[0039] The obtained antistatic TAC high-transmittance silicone protective film has a light transmittance of 94.1% and a surface resistivity of 5.4×10 9 Ω; no debonding or cracking after being treated in a hot and humid environment of 80°C and 90% humidity for 48 hours; the peel strength value to the glass substrate is 7.9N / 25mm.

[0040] Example 3

[0041] A method for preparing an antistatic TAC high-transmittance silicone protective film comprises the following preparation steps:

[0042] (1) TAC and 3% (relative to the mass percentage of TAC) of sodium cellulose sulfate antistatic agent were added to DMF solvent for dissolution and degassing to obtain a glue solution with a solid content of 36%, which was then formed by casting and drying to obtain an antistatic TAC film with a thickness of 100 μm.

[0043] (2) coating the surface of the antistatic TAC film in step (1) with an organic silicone pressure-sensitive adhesive (the adhesive comprises, by weight, 100 parts of a vinyl polysiloxane having a molecular weight of 100,000 and a vinyl content of 4.0% (wt.%), 20 parts of a hydrogen-containing polysiloxane having a molecular weight of 10,000 and a hydrogen content of 0.5% (wt.%), 2 parts of vinyl trimethoxy silane, 3 parts of 3-isocyanate propyl triethoxy silane, 0.01 parts of a polyvinyl siloxane-platinum complex catalyst, 0.1 parts of an acetylene cyclohexanol inhibitor and 50 parts of a diluent solvent, toluene), heating to 80-90° C. and drying and curing for 2 hours to obtain an organic silicone pressure-sensitive adhesive layer having a thickness of 10 μm.

[0044] (3) A release film layer is coated on the surface of the organic silicone pressure-sensitive adhesive layer in step (2) to obtain an antistatic TAC high-transmittance silicone protective film.

[0045] The light transmittance of the obtained antistatic TAC high-transmittance silicone protective film was measured to be 92.4%; the surface resistivity of the TAC film layer was 3.8×10 7 Ω; no debonding or cracking after being treated in a hot and humid environment of 80°C and 90% humidity for 48 hours; the peel strength value to the glass substrate is 8.2N / 25mm.

[0046] Example 4

[0047] A method for preparing an antistatic TAC high-transmittance silicone protective film, compared with Example 1, uses stearamidopropyl hydroxyethyl quaternary ammonium nitrate antistatic agent instead of cellulose sodium sulfate antistatic agent, and the rest is the same.

[0048] The obtained antistatic TAC high-transmittance silicone protective film was measured to have a light transmittance of 92.5%; the surface resistivity of the TAC film layer was 8.0×10 8 Ω.

[0049] By comparing the results with those of Example 1, it can be seen that the present invention uses specific sodium cellulose sulfate as an antistatic agent, which has better compatibility with TAC, and the resulting antistatic TAC film has a higher light transmittance.

[0050] Comparative Example 1

[0051] A method for preparing an antistatic TAC high-transmittance silica gel protective film, compared with Example 1, uses inorganic antistatic agent aluminum oxide to replace the sodium cellulose sulfate antistatic agent, and the rest is the same.

[0052] The obtained antistatic TAC high-transmittance silicone protective film was measured to have a light transmittance of 91.7%; the surface resistivity of the TAC film layer was 5.5×10 8 Ω.

[0053] By comparing the results with those of Examples 1 and 4, it can be seen that the use of inorganic antistatic agents has an adverse effect on the light transmittance of the TAC film.

[0054] Comparative Example 2

[0055] A method for preparing an antistatic TAC high-transmittance silicone protective film. Compared with Example 1, 3-isocyanate propyltriethoxysilane is not added to the silicone pressure-sensitive adhesive solution, the content of vinyltrimethoxysilane is increased to 5 parts, and the rest is the same.

[0056] The obtained antistatic TAC high-transmittance silica gel protective film was partially debonded after being treated in a hot and humid environment of 80° C. and 90% humidity for 48 hours; the peel strength value to the glass substrate was 7.8N / 25mm.

[0057] By comparing the results with those of Example 1, it can be seen that the bonding composite stability of the silicone pressure-sensitive adhesive using vinyltrimethoxysilane alone to the antistatic TAC film is significantly reduced, and the bonding performance to the glass substrate is also reduced to a certain extent.

[0058] Comparative Example 3

[0059] A method for preparing an antistatic TAC high-transmittance silicone protective film. Compared with Example 1, no vinyl trimethoxy silane is added to the silicone pressure-sensitive adhesive solution, the content of 3-isocyanate propyl triethoxy silane is increased to 5 parts, and the rest is the same.

[0060] The obtained antistatic TAC high-transmittance silica gel protective film was partially debonded after being treated in a hot and humid environment of 80° C. and 90% humidity for 48 hours; the peel strength value to the glass substrate was 7.2N / 25mm.

[0061] By comparing the results with those of Example 1, it can be seen that the bonding composite stability of the antistatic TAC film and the bonding performance to the glass substrate of the silicone pressure-sensitive adhesive using 3-isocyanatepropyltriethoxysilane alone are significantly reduced.

[0062] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention shall be equivalent replacement methods and shall be included in the protection scope of the present invention.

Claims

1. A method for preparing an antistatic TAC high-transmittance silica gel protective film, characterized in that: The method comprises the following preparation steps: (1) adding TAC and an organic antistatic agent into an organic solvent to dissolve and degas to obtain a glue solution, and then forming the solution by casting and drying to obtain an antistatic TAC film; (2) coating the surface of the antistatic TAC film in step (1) with an organic silicone pressure-sensitive adhesive solution, and heating, drying and curing the solution to obtain an organic silicone pressure-sensitive adhesive layer; (3) A release film layer is coated on the surface of the organic silicone pressure-sensitive adhesive layer in step (2) to obtain an antistatic TAC high-transmittance silicone protective film.

2. The method for preparing an antistatic TAC high-transmittance silica gel protective film according to claim 1, characterized in that: The organic antistatic agent in step (1) is sodium cellulose sulfate, and the amount of the organic antistatic agent added is 0.5% to 3% of the mass of TAC.

3. The method for preparing an antistatic TAC high-transmittance silica gel protective film according to claim 1, characterized in that: The organic solvent in step (1) is one or a mixed solvent of two or more selected from the group consisting of N-methylpyrrolidone, dimethylformamide, acetone and dichloromethane.

4. The method for preparing an antistatic TAC high-transmittance silica gel protective film according to claim 1, characterized in that: The thickness of the antistatic TAC film in step (1) is 10 to 100 μm.

5. The method for preparing an antistatic TAC high-transmittance silica gel protective film according to claim 1, characterized in that: The organic silicon pressure-sensitive adhesive solution in step (2) comprises vinyl polysiloxane, hydrogen-containing polysiloxane, vinyl silane coupling agent, isocyanate silane coupling agent, platinum catalyst, inhibitor and diluent solvent.

6. The method for preparing an antistatic TAC high-transmittance silica gel protective film according to claim 5, characterized in that: The molecular weight of the vinyl polysiloxane is 50,000 to 500,000, and the vinyl content is 0.2% to 10%; the molecular weight of the hydrogen-containing polysiloxane is 5,000 to 50,000, and the hydrogen content is 0.2% to 1%; the addition amount of the hydrogen-containing polysiloxane is 5% to 50% of the mass of the vinyl polysiloxane.

7. The method for preparing an antistatic TAC high-transmittance silica gel protective film according to claim 5, characterized in that: The vinyl silane coupling agent is vinyl trimethoxy silane or vinyl triethoxy silane, and the added amount of the vinyl silane coupling agent is 1% to 5% of the mass of the vinyl polysiloxane; the isocyanate silane coupling agent is 3-isocyanate propyl trimethoxy silane or 3-isocyanate propyl triethoxy silane, and the added amount of the isocyanate silane coupling agent is 1% to 5% of the mass of the vinyl polysiloxane.

8. The method for preparing an antistatic TAC high-transmittance silica gel protective film according to claim 5, characterized in that: The platinum catalyst is a polyvinylsiloxane-platinum complex, and the added amount of the platinum catalyst is 0.005% to 0.02% of the mass of the vinyl polysiloxane; the inhibitor is methyl butynol, acetylene cyclohexanol or 3,7,11-trimethyldodecene-3-ol, and the added amount of the inhibitor is 0.05% to 0.2% of the mass of the vinyl polysiloxane; the dilution solvent is toluene, xylene, ethyl acetate, solvent gasoline or petroleum ether, and the added amount of the dilution solvent is 20% to 100% of the mass of the vinyl polysiloxane.

9. The method for preparing an antistatic TAC high-transmittance silica gel protective film according to claim 1, characterized in that: The thickness of the organic silicone pressure-sensitive adhesive layer in step (2) is 1 to 10 μm.

10. An antistatic TAC high-transmittance silicone protective film, characterized in that: The antistatic TAC high-transmittance silica gel protective film is prepared by the method according to any one of claims 1 to 9, and the light transmittance of the antistatic TAC high-transmittance silica gel protective film is greater than 92%.