Antistatic agent long-acting attached silica gel protective film and preparation method and application thereof

Abstract

This invention discloses a silicone protective film with long-lasting antistatic agent adhesion, its preparation method, and its application, belonging to the field of protective film technology. The silicone protective film sequentially comprises a release layer, a silicone adhesive layer, and an antistatic base layer; the antistatic base layer comprises an antistatic polymer layer and a PET substrate layer; using a silane coupling agent as a bridge, the hydrolyzed groups of the silane coupling agent are chemically bonded to the surface of the PET substrate, and the organic ends are combined with the MBA crosslinking network, thereby fixing the antistatic agent PEDOT:PSS onto the PET substrate to form the antistatic polymer layer. This invention discloses a silicone protective film with long-lasting antistatic agent adhesion, where the antistatic agent adheres firmly, the protective film withstands more than 5000 abrasion cycles, and the surface resistance remains at 10 Ω. 7 With an Ω rating of around 100 ohms, the performance is durable and stable; the overall light transmittance of the protective film is ≥93%, and the haze is ≤0.6%, meeting the requirements for use in optical-grade products and suitable for surface protection of precision electronic equipment and optical components.

Description

Technical Field

[0001] This invention relates to the field of protective film technology, specifically to a silicone protective film with long-lasting antistatic agent adhesion, its preparation method, and its application. Background Technology

[0002] Silicone protective films are widely used for surface protection of precision electronic equipment and optical components due to their good adhesion and no residue after peeling. Antistatic performance is one of the core indicators of this type of protective film, which can effectively prevent problems such as static electricity attracting dust and damaging electronic components.

[0003] Traditional antistatic silicone protective films typically employ a surface coating method to attach the antistatic agent to the substrate surface. The bond between the antistatic agent and the substrate is limited to physical adsorption or weak van der Waals forces. For example, the antistatic agent, such as the polymer 3,4-ethylenedioxythiophene:polystyrene sulfonate (PEDOT:PSS), composed of poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate (PSS), has weak adhesion to flexible substrates like polyethylene terephthalate (PET). To mitigate this issue, appropriate film-forming resins and various additives are usually added to improve the adhesion between PEDOT:PSS and PET. However, this still cannot prevent the antistatic agent from detaching during use, leading to a rapid decline in antistatic performance.

[0004] Therefore, developing a silicone protective film that has antistatic agents that are not easily detached and has stable antistatic properties has become a technical challenge that the industry urgently needs to solve. Summary of the Invention

[0005] The purpose of this invention is to provide a silicone protective film with long-lasting antistatic agent adhesion, its preparation method and application. Without compromising the light transmittance, adhesion and structural stability of the protective film, it can alleviate the problems of easy wear and fall-off of antistatic agents and rapid performance degradation in traditional products.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a silicone protective film with long-lasting antistatic agent adhesion, wherein the silicone protective film comprises, in sequence, a release layer, a silicone adhesive layer, and an antistatic base layer; the antistatic base layer comprises an antistatic polymer layer and a PET substrate layer; the antistatic polymer layer is formed by in-situ polymerization after coating the PET substrate layer with an antistatic polymer solution containing PEDOT:PSS, a silane coupling agent, a polymerization initiator, N,N'-methylenebisacrylamide, and a mixed solvent; the thickness of the antistatic polymer layer is 2~5μm.

[0008] The antistatic polymer layer is only 2~5μm thick, and when combined with a high-transmittance silicone adhesive layer, the overall light transmittance of the protective film is ≥93%, and the haze is ≤0.6%, meeting the requirements for use in optical-grade products.

[0009] Furthermore, the release layer is a PET release film or a biodegradable polylactic acid release film; the thickness of the release layer is 30~50μm.

[0010] Furthermore, the thickness of the silicone adhesive layer is 8~15μm.

[0011] Furthermore, the thickness of the antistatic base layer is 20~40μm.

[0012] Secondly, the present invention provides a method for preparing a silicone protective film with long-lasting antistatic agent adhesion, comprising the following steps:

[0013] Step S1: Apply the antistatic polymer liquid to the cleaned and dried PET substrate, and react to obtain the antistatic base layer;

[0014] Step S2: Apply silicone adhesive to the antistatic base layer and react to form a silicone adhesive layer on the antistatic base layer;

[0015] Step S3: Attach the release layer to the silicone adhesive layer to obtain a silicone protective film with long-lasting antistatic agent adhesion.

[0016] Furthermore, the mass ratio of PEDOT:PSS, silane coupling agent, polymerization initiator, N,N'-methylenebisacrylamide and mixed solvent in the antistatic polymerization liquid is (12~18):(4~6):(0.8~1.2):(2.5~4):(45~55).

[0017] Furthermore, the silane coupling agent includes γ-methacryloxypropyltrimethoxysilane (KH570) or γ-aminopropyltriethoxysilane (KH550).

[0018] Furthermore, the polymerization initiator is azobisisobutyronitrile (AIBN) or benzoyl peroxide (BPO).

[0019] Furthermore, the mixed solvent is a mixture of anhydrous ethanol, ethyl acetate, and deionized water.

[0020] PEDOT itself is insoluble in water. By combining with PSS, which has good water dispersibility, a core-shell structure is formed where PSS molecular chains encapsulate PEDOT, thereby improving the water dispersibility of PEDOT. Since PSS itself has weak antistatic properties, conventional PEDOT:PSS aqueous solutions are difficult to achieve ideal antistatic effects. Using anhydrous ethanol, ethyl acetate, and water as solvents, the moderate polarity of ethyl acetate bridges the hydrophilic PSS / aqueous phase and the hydrophobic KH570 / organic phase, forming a uniform and stable coating solution and preventing component aggregation or phase separation before coating. After coating, ethyl acetate evaporates first, and the proportion of ethanol and water in the remaining solvent increases significantly. The hydroxyl groups in the ethanol molecules can form strong hydrogen bonds with the sulfonate groups in PSS, thereby inducing phase separation of PEDOT:PSS, attracting PSS segments to accumulate on the PET substrate surface, while PEDOT undergoes π-π stacking, forming a crystalline network of interwoven PEDOT molecular chains with good antistatic properties.

[0021] Furthermore, the volume ratio of anhydrous ethanol, ethyl acetate, and deionized water is 3:2:1.

[0022] Further, in step S1, the coating amount of the electrostatic polymer liquid is 5~7 g / m²; the reaction temperature is 105~115℃; and the reaction time is 35~40 min.

[0023] MBA forms a cross-linked network under the action of AIBN or BPO, encapsulating the antistatic component and preventing the antistatic agent from falling off. The double bond structure at the organic end of KH570 can directly polymerize with MBA. The organic end of KH570 is embedded in the MBA cross-linked network to form a two-component cross-linked network, thereby fixing the antistatic component encapsulated in MBA onto the PET substrate. KH550 can fix the MBA cross-linked network containing the antistatic component onto the PET substrate through the hydrogen bonding between the terminal primary amine and the MBA cross-linked network.

[0024] Furthermore, in step S2, the silicone adhesive includes silicone liquid and additives.

[0025] Furthermore, the silicone adhesive comprises vinyl-terminated dimethylsiloxane, hydrogen-containing MQ silicone resin, and nano-silica.

[0026] Furthermore, the additives include platinum(0)-1,3-diethylene-1,1,3,3-tetramethyldisiloxane (Karstedt catalyst) and 1-ethynylcyclohexanol.

[0027] Furthermore, the mass ratio of the vinyl-terminated dimethylsiloxane, hydrogen-containing MQ silicone resin, nano-silica, Karstedt catalyst, and 1-ethynylcyclohexanol is (55~65):(18~22):(6~10):(0.4~0.6):(0.15~0.25).

[0028] Furthermore, in step S2, the coating amount of the silicone adhesive is 12~14 g / m²; the reaction temperature is 125~135℃, and the reaction time is 18~20 min.

[0029] The preparation process is simple and controllable, and industrial production can be achieved using conventional coating and curing equipment. The production cost is comparable to that of traditional protective films, and it has a wide range of applications.

[0030] Thirdly, the present invention provides an application of the silicone protective film with long-lasting antistatic agent adhesion as described in the first aspect in the surface protection of precision electronic equipment or optical components.

[0031] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0032] This invention provides a silicone protective film with long-lasting antistatic agent adhesion. The antistatic agent coated on this protective film is not easily detached, and the antistatic performance of the film is durable and stable, making it suitable for surface protection of precision electronic equipment and optical components. Using PET as the substrate, an antistatic polymer solution is coated onto the PET substrate, triggering a polymerization reaction to construct an antistatic polymer layer, forming an antistatic base layer. The antistatic polymer layer forms a chemical bond with the PET substrate through a silane coupling agent, fixing one end of the silane coupling agent to the PET substrate. The other end of the silane coupling agent can form a three-dimensional cross-linked network with MBA, and PEDOOT:PSS is locked in situ within the network. The entire cross-linked network is connected to the surface of the PET substrate through the silane coupling agent, ensuring that the resistivity of the protective film remains stable at 6 × 10⁻⁶ after 5000 cycles of friction. 7 Ω or higher, compared to the original initial surface resistance (2×10). 7 (Above Ω) has an extremely low attenuation rate.

[0033] The silicone adhesive incorporates nano-silica, which enhances the wear resistance and adhesion of the adhesive layer. After bonding, there is no edge lifting or residue. Even after being placed in a high temperature and high humidity environment (85℃ / 85%RH) for 72 hours, the interlayer peel strength is still ≥1.0N / 25mm, demonstrating good structural stability. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the structure of a silane protective film with long-lasting adhesion of antistatic agents.

[0035] Explanation of reference numerals in the attached drawings: 1. Release layer; 2. Silicone adhesive layer; 3. Antistatic base layer; 31. Antistatic polymer layer; 32. PET substrate layer. Detailed Implementation

[0036] The technical solution of the present invention will be described in detail below through specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations on the technical solution of the present invention. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0037] The term "and / or" simply describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0038] Example 1

[0039] like Figure 1 As shown, a silicone protective film with long-lasting antistatic agent adhesion and its preparation method are disclosed. The silicone protective film comprises a release layer 1, a silicone adhesive layer 2, and an antistatic base layer 3. The antistatic base layer 3 comprises an antistatic polymer layer 31 and a PET substrate layer 32. The thickness of the antistatic base layer 3 is 30 μm, the thickness of the antistatic polymer layer 31 is 4 μm, the thickness of the silicone adhesive layer 2 is 12 μm, and the release layer 1 is a PET release film with a thickness of 40 μm.

[0040] A method for preparing a silicone protective film with long-lasting antistatic agent adhesion includes the following steps:

[0041] S1. The PET substrate is ultrasonically cleaned for 12 minutes and dried at 70°C. The antistatic polymer solution is stirred at 350 r / min for 25 minutes and coated on the PET substrate layer 32 at a coating amount of 6 g / m². The mixture is then reacted at 110°C for 40 minutes to obtain the antistatic base layer 3.

[0042] The antistatic polymerization solution comprises PEDOT:PSS, KH570, AIBN, N,N'-methylenebisacrylamide, and a mixed solvent; the mass ratio of PEDOT:PSS, KH570, AIBN, N,N'-methylenebisacrylamide, and the mixed solvent is 15:5:1:3:50; the volume ratio of anhydrous ethanol, ethyl acetate, and deionized water in the mixed solvent is 3:2:1. During the preparation process, each material is weighed according to the mass ratio and mixed thoroughly.

[0043] S2. The silicone adhesive is dispersed at 1200r / min for 18min, and the additive is added and stirred for 8min. It is then applied to the antistatic base layer 3 at a coating amount of 12g / m² and reacted at 130℃ for 18min to form a silicone adhesive layer 2 on the antistatic base layer 3.

[0044] The silicone adhesive comprises: vinyl-terminated dimethylsiloxane, hydrogen-containing MQ silicone resin, and nano-silica; the additives comprise Karstedt catalyst and 1-ethynylcyclohexanol; the mass ratio of vinyl-terminated dimethylsiloxane, hydrogen-containing MQ silicone resin, nano-silica, Karstedt catalyst, and 1-ethynylcyclohexanol is 60:20:8:0.5:0.2. During preparation, each material is weighed according to the mass ratio and mixed thoroughly.

[0045] S3. The release layer 1 is bonded to the silicone adhesive layer 2 at a pressure of 0.3 MPa and at a temperature of 45°C for 1.5 min. The release layer 1 is a PET release film. The silicone protective film with long-lasting antistatic agent adhesion is obtained by cutting and rolling.

[0046] Performance testing: Initial surface resistivity is 3×10⁻⁶ 7 Ω, after 5000 friction cycles, becomes 8×10 7 Ω; light transmittance 93.8%, haze 0.5%; after being placed at 85℃ / 85%RH for 72h, the interlayer peel strength is 1.2N / 25mm.

[0047] Example 2

[0048] like Figure 1 As shown, a silicone protective film with long-lasting antistatic agent adhesion and its preparation method are disclosed. The silicone protective film comprises a release layer 1, a silicone adhesive layer 2, and an antistatic base layer 3. The antistatic base layer 3 comprises an antistatic polymer layer 31 and a PET substrate layer 32. The thickness of the antistatic base layer 3 is 25 μm, the thickness of the antistatic polymer layer 31 is 2 μm, the thickness of the silicone adhesive layer 2 is 10 μm, and the release layer 1 is a polylactic acid release film with a thickness of 35 μm.

[0049] A method for preparing a silicone protective film with long-lasting antistatic agent adhesion includes the following steps:

[0050] S1. The PET substrate is ultrasonically cleaned for 12 minutes and dried at 70°C. The antistatic polymer solution is stirred at 350 r / min for 25 minutes and coated on the PET substrate layer 32 at a coating amount of 5 g / m². The mixture is then reacted at 105°C for 35 minutes to obtain the antistatic base layer 3.

[0051] The antistatic polymerization solution comprises PEDOT:PSS, KH550, BPO, N,N'-methylenebisacrylamide, and a mixed solvent; the mass ratio of PEDOT:PSS, KH550, BPO, N,N'-methylenebisacrylamide, and the mixed solvent is 12:4:0.8:2.5:45; the volume ratio of anhydrous ethanol, ethyl acetate, and deionized water in the mixed solvent is 3:2:1. During preparation, each material is weighed according to the mass ratio and mixed thoroughly.

[0052] S2. The silicone adhesive is dispersed at 1200r / min for 18min, and the additive is added and stirred for 8min. It is then applied to the antistatic base layer 3 at a coating amount of 13g / m² and reacted at 125℃ for 20min to form a silicone adhesive layer 2 on the antistatic base layer 3.

[0053] The silicone adhesive comprises: vinyl-terminated dimethylsiloxane, hydrogen-containing MQ silicone resin, and nano-silica; the additives comprise Karstedt catalyst and 1-ethynylcyclohexanol; the mass ratio of vinyl-terminated dimethylsiloxane, hydrogen-containing MQ silicone resin, nano-silica, Karstedt catalyst, and 1-ethynylcyclohexanol is 55:18:6:0.4:0.15. During preparation, each material is weighed according to the mass ratio and mixed thoroughly.

[0054] S3. The release layer 1 is bonded to the silicone adhesive layer 2 at a pressure of 0.3 MPa for 1.5 min at 45°C. The release layer 1 is a biodegradable polylactic acid release film. The film is cut and rolled up to obtain a silicone protective film with long-lasting antistatic agent adhesion.

[0055] Performance testing: Initial surface resistivity value is 5×10⁻⁶ 7 Ω, after 5000 friction cycles, becomes 1×10 8 Ω; light transmittance 93.2%, haze 0.6%; interlayer peel strength 1.0N / 25mm.

[0056] Example 3

[0057] like Figure 1 As shown, a silicone protective film with long-lasting antistatic agent adhesion and its preparation method are disclosed. The silicone protective film comprises a release layer 1, a silicone adhesive layer 2, and an antistatic base layer 3. The antistatic base layer 3 comprises an antistatic polymer layer 31 and a PET substrate layer 32. The thickness of the antistatic base layer 3 is 35 μm, the thickness of the antistatic polymer layer 31 is 5 μm, the thickness of the silicone adhesive layer 2 is 14 μm, and the release layer 1 is a polylactic acid release film with a thickness of 45 μm.

[0058] A method for preparing a silicone protective film with long-lasting antistatic agent adhesion includes the following steps:

[0059] S1. The PET substrate is ultrasonically cleaned for 12 minutes and dried at 70°C. The antistatic polymer solution is stirred at 350 r / min for 25 minutes and coated on the PET substrate layer 32 at a coating amount of 7 g / m². The mixture is then reacted at 115°C for 35 minutes to obtain the antistatic base layer 3.

[0060] The antistatic polymerization solution comprises PEDOT:PSS, KH570, AIBN, N,N'-methylenebisacrylamide, and a mixed solvent; the mass ratio of PEDOT:PSS, KH570, AIBN, N,N'-methylenebisacrylamide, and the mixed solvent is 18:6:1.2:4:55; the volume ratio of anhydrous ethanol, ethyl acetate, and deionized water in the mixed solvent is 3:2:1. During the preparation process, each material is weighed according to the mass ratio and mixed thoroughly.

[0061] S2. The silicone adhesive is dispersed at 1200r / min for 18min, and the additive is added and stirred for 8min. It is then applied to the antistatic base layer 3 at a coating amount of 14g / m² and reacted at 135℃ for 20min to form a silicone adhesive layer 2 on the antistatic base layer 3.

[0062] The silicone adhesive comprises: vinyl-terminated dimethylsiloxane, hydrogen-containing MQ silicone resin, and nano-silica; the additives comprise Karstedt catalyst and 1-ethynylcyclohexanol; the mass ratio of vinyl-terminated dimethylsiloxane, hydrogen-containing MQ silicone resin, nano-silica, Karstedt catalyst, and 1-ethynylcyclohexanol is 65:22:10:0.6:0.25. During preparation, each material is weighed according to the mass ratio and mixed thoroughly.

[0063] S3. The release layer 1 is bonded to the silicone adhesive layer 2 at a pressure of 0.3 MPa and at a temperature of 45°C for 1.5 min. The release layer 1 is a PET release film. The silicone protective film with long-lasting antistatic agent adhesion is obtained by cutting and rolling.

[0064] Performance testing: Initial surface resistivity is 2×10⁻⁶ 7 Ω, after 5000 friction cycles, becomes 6×10 7 Ω; transmittance 94.1%, haze 0.4%; interlayer peel strength 1.3N / 25mm.

[0065] Comparative Example 1

[0066] A silicone protective film with long-lasting antistatic agent adhesion and its preparation method are disclosed. The antistatic base layer 3 has a thickness of 30 μm, the antistatic coating has a thickness of 4 μm, the silicone adhesive layer 2 has a thickness of 12 μm, and the release layer is a PET release film with a thickness of 40 μm. The difference from Example 1 is that no antistatic polymerization solution is used; instead, PEDOT:PSS is directly dispersed in deionized water and coated onto a PET substrate. All other operations and process parameters are the same as in Example 1.

[0067] Performance testing: Initial surface resistivity is 3×10⁻⁶ 7 Ω, after 5000 friction cycles, is >1×10 11 Ω; transmittance 87.3%, haze 1.8%; interlayer peel strength 0.4N / 25mm. Although the initial surface resistivity was low, it increased significantly after 5000 rubs, indicating that the antistatic agent was only physically adsorbed on the PET substrate surface and lacked the locking effect of the polymer cross-linking network. A large amount of it fell off during the rubbing process, and the antistatic performance quickly failed. At the same time, the interlayer peel strength was much lower than that of Examples 1 to 3, and the peel failure interface was located between the PET substrate and the antistatic coating, indicating that the interfacial adhesion between the simple PEDOT:PSS coating and PET was seriously insufficient.

[0068] The embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A silicone protective film with long-term attachment of an antistatic agent, characterized in that, The silicone protective film comprises a release layer (1), a silicone adhesive layer (2), and an antistatic base layer (3) in sequence; the antistatic base layer (3) comprises an antistatic polymer layer (31) and a PET substrate layer (32); the antistatic polymer layer (31) is formed by in-situ polymerization after coating the PET substrate layer (32) with an antistatic polymer solution containing PEDOT:PSS, silane coupling agent, polymerization initiator, N,N'-methylenebisacrylamide and a mixed solvent; the thickness of the antistatic polymer layer (31) is 2~5μm.

2. The silicone protective film for long-lasting adhesion of antistatic agent according to claim 1, characterized in that, The release layer (1) is a PET release film or a biodegradable polylactic acid release film; the thickness of the release layer (1) is 30~50μm.

3. The silicone protective film for long-lasting adhesion of antistatic agent according to claim 1, characterized in that, The thickness of the silicone adhesive layer (2) is 8~15μm.

4. The silicone protective film for long-lasting adhesion of antistatic agent according to claim 1, characterized in that, The thickness of the antistatic base layer (3) is 20~40μm.

5. A method for preparing a silicone protective film with long-lasting antistatic agent adhesion as described in any one of claims 1-4, characterized in that, Includes the following steps: S1. Apply the antistatic polymer liquid onto the cleaned and dried PET substrate layer (32), and react to obtain the antistatic base layer (3). S2. Apply silicone adhesive to the antistatic base layer (3) and react to form a silicone adhesive layer (2) on the antistatic base layer (3). S3. The release layer (1) is attached to the silicone adhesive layer (2) to obtain a silicone protective film with long-lasting antistatic agent adhesion.

6. The method for preparing a silicone protective film with long-lasting antistatic agent adhesion according to claim 5, characterized in that, In step S1, the mass ratio of PEDOT:PSS, silane coupling agent, polymerization initiator, N.N'-methylenebisacrylamide, and mixed solvent in the antistatic polymerization liquid is (12~18):(4~6):(0.8~1.2):(2.5~4):(45~55); the silane coupling agent is KH570 or KH550; the polymerization initiator is AIBN or BPO; the mixed solvent is a mixture of anhydrous ethanol, ethyl acetate, and deionized water, and the volume ratio of anhydrous ethanol, ethyl acetate, and deionized water is 3:2:

1.

7. The method for preparing a silicone protective film with long-lasting antistatic agent adhesion according to claim 5, characterized in that, In step S1, the coating amount of the electrostatic polymer liquid is 5~7 g / m²; the reaction temperature is 105~115℃; and the reaction time is 35~40 min.

8. The method for preparing a silicone protective film with long-lasting antistatic agent adhesion according to claim 5, characterized in that, In step S2, the silicone adhesive comprises silicone liquid and additives; the silicone liquid comprises vinyl-terminated dimethylsiloxane, hydrogen-containing MQ silicone resin, and nano-silica; the additives comprise Karstedt catalyst and 1-ethynylcyclohexanol; the mass ratio of vinyl-terminated dimethylsiloxane, hydrogen-containing MQ silicone resin, nano-silica, Karstedt catalyst, and 1-ethynylcyclohexanol is (55~65):(18~22):(6~10):(0.4~0.6):(0.15~0.25).

9. The method for preparing a silicone protective film with long-lasting antistatic agent adhesion according to claim 5, characterized in that, In step S2, the coating amount of the silicone adhesive is 12~14 g / m²; the reaction temperature is 125~135℃, and the reaction time is 18~20 min.

10. The application of a silicone protective film with long-lasting antistatic agent adhesion as described in any one of claims 1 to 4 in the surface protection of precision electronic equipment or optical components.

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