Antistatic release film and preparation method thereof

Abstract

The invention discloses an antistatic release film and a preparation method thereof, and belongs to the technical field of screen protection films for large-screen mobile phones. The antistatic release film comprises a protective film, a release coating and a base film which are sequentially arranged from top to bottom, the protective film is a light release protective film, the base film is made of a PET material, and the release coating comprises a release agent, a curing agent, an antistatic agent, a catalyst and a solvent. According to the preparation method of the ultra-light release film, the preparation process is simple, the crosslinking density of a product is remarkably improved through an efficient curing process, the material is endowed with excellent mechanical strength, weather resistance and long-term stability, and layering or deformation in the using process is avoided; by changing the type and the adding proportion of the release agent and then thermosetting in a precise coating mode, on the basis of ensuring complete curing of the release coating, the uniformity and consistency control of the coating is realized, and the product yield is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of large-screen mobile phone screen protectors, and particularly relates to an antistatic release film and a preparation method thereof. Background Art

[0002] The ultra-light release film is a protective film designed specifically for adhesive materials such as silicone. It usually uses polyethylene terephthalate (PET) as the base material, with a silicone oil or other release agent coated on the surface, and realizes lightweight design through precision coating technology. Its main function is to provide a controllable release force, protect the adhesive layer from contamination or damage, and facilitate die-cutting, laminating, and peeling during the processing.

[0003] Although the ultra-thin design has achieved lightweight, its mechanical strength is low, and it is prone to tearing or breakage during processing or use. Secondly, the stability of the release force is difficult to precisely control, and there may be phenomena such as uneven release force or decay over time, affecting the use effect. In high-temperature or high-humidity environments, the weather resistance and chemical stability of some release films are insufficient, and the performance is prone to decline. In terms of environmental protection, the traditional solvent-based system has problems with the emission of volatile organic compounds (VOCs), which does not meet the requirements of green manufacturing. Finally, the development of functional release films (such as antistatic and high-temperature resistant) still faces technical bottlenecks and is difficult to meet the needs of high-end applications. These problems limit the further promotion and application of ultra-light release films. For example, the patent application with the publication number CN118853019 A discloses an ultra-light release film for optical adhesive and its preparation process, which uses polyethylene wax, vinyl MQ silicone resin, and epoxy-modified silicone resin as the main components, prepares silicone oil through a three-stage heat preservation process, and combines functional additives (such as bauxite powder and cerium oxide) to improve the gloss and mechanical properties of the release film; however, the toughening agent (nitrile / butadiene rubber) in its formula may reduce the crosslinking density of the release layer, and the release force is prone to decay after long-term use. In addition, the functional additives of nano-level bauxite powder and cerium oxide may face problems of difficult dispersion. Therefore, it is an urgent problem in this field to prepare an antistatic release film. Summary of the Invention

[0004] The purpose of the present invention is to provide an antistatic release film and a preparation method thereof, so as to reduce the tearing force of the release film while improving the antistatic performance of the release film and increasing the yield rate.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] An antistatic release film, comprising, from top to bottom in sequence: a protective film, a release coating, and a base film;

[0007] The protective film is a light release protective film, the base film is made of PET material, and the release coating includes a release agent, a curing agent, an antistatic agent, a catalyst, and a solvent.

[0008] Furthermore, the dosage ratios of the release agent, curing agent, antistatic agent, catalyst and solvent are (0.001 - 4):(0.001 - 2):(0.1 - 1):(0.001 - 2):(20 - 80).

[0009] Furthermore, the model of the release agent is one or a combination of several of release agent 7755, release agent 7765 and release agent 7775.

[0010] Furthermore, the model of the curing agent is curing agent 7570.

[0011] Furthermore, the model of the antistatic agent is antistatic agent YX - 120.

[0012] Furthermore, the model of the catalyst is one or a combination of several of catalyst 4000, catalyst 4200 and catalyst 4500.

[0013] Furthermore, the model of the solvent is one or a combination of several of solvent DT, solvent 2T, solvent 120#.

[0014] Among them, the release coating is a special coating applied on the surface of the substrate, mainly used to provide the property of easy peeling, and is widely used in fields such as tapes, labels, composite materials, etc. Its main function is to prevent the materials from sticking during storage or transportation, and at the same time, it can be easily peeled off during use. The core component of the release coating is the release agent, and common ones include silicone release agents and non - silicone release agents. Silicone release agents are the most widely used due to their excellent high - temperature resistance, stability and release effect; non - silicone release agents are suitable for scenarios with special requirements for surface energy or adhesion.

[0015] The preparation of ultra-light release films suitable for silicone mainly focuses on material formulation, coating process, and function optimization. The core lies in using high-purity silicone resin as the base material and enhancing the film's performance by adding curing agents (such as platinum catalysts or peroxides) and functional additives (such as antistatic agents and antioxidants). In the coating process, precise coating technology is used to evenly coat the silicone solution on substrates such as PET, and the silicone is crosslinked through thermal curing or UV curing to form an ultra-thin and uniform release layer, usually with a thickness controlled below 10 microns to achieve lightweight design. The selection and coating of the release agent are crucial. Commonly used fluorine-based or silicone-based release agents are used to control the release force by adjusting the coating amount to meet different application requirements. In addition, surface treatment technologies (such as corona treatment and antistatic coatings) further enhance the functionality of the release film. Detection technologies (such as on-line thickness detection and release force testing) ensure the consistency and reliability of the product. In terms of environmental protection, the development of water-based silicone systems and solvent-free formulations reduces VOC emissions, conforming to the trend of green manufacturing. These technologies enable silicone ultra-light release films to be widely used in fields such as electronics, medical, and new energy, combining the advantages of high performance, lightweight, and environmental protection.

[0016] A preparation method of an antistatic release film includes the following steps:

[0017] S1. Add the release agent and solvent into a reaction vessel and stir. After slowly adding the antistatic agent and curing agent, add the catalyst and continue stirring to ensure that all raw materials are fully and evenly mixed;

[0018] S2. Place the evenly mixed raw materials in the reaction vessel and heat them for reaction to generate a release coating;

[0019] S3. Coating the prepared release coating on the base film through precision coating. After the coating is completed, under the coverage of the protective film, make the release coating closely adhere to the base film by means of roll pressing and compact it into shape to obtain an ultra-light release film suitable for silicone.

[0020] Further, the stirring speed is 300 - 500 r / min; the stirring time is 1 - 1.5 h.

[0021] Further, the heating reaction is to heat to 50 - 80 °C and react at this temperature for 3 - 4 h.

[0022] Further, the precision coating is slit coating or microgravure coating.

[0023] Further, the thickness of the ultra-light release film is 5 - 10 μm.

[0024] The beneficial effects of the present invention:

[0025] (1) A preparation method of an ultra-light release film provided by the present invention has a simple preparation process. Through an efficient curing process, the cross-linking density of the product is significantly increased, endowing the material with excellent mechanical strength, weather resistance and long-term stability, and avoiding delamination or deformation during use. By changing the type and addition ratio of the release agent, and then through a precise coating method and heat curing, on the basis of ensuring complete curing of the release coating, the uniformity and consistency of the coating are simultaneously controlled, and the product yield is improved.

[0026] (2) The release agent used in the present invention is coated on the surface of the release film (such as a PET substrate). By regulating the peeling force, it is ensured that the adhesive layer and the release film can be stably adhered and can be controllably peeled during the process. The antistatic agent used migrates to the surface of the coating to form a conductive layer, reducing the surface resistance and reducing the microcracks or bubbles in the adhesive layer caused by static electricity when the protective film is peeled. In addition, it has good compatibility with the release agent system. When used simultaneously, the prepared release film has a lower tearing force and a better antistatic agent effect. In addition, it can inhibit the ion migration between the release film and the coating in a high-temperature and high-humidity environment, prevent the coating from yellowing or the viscosity from decreasing, and enhance the stability of the ultra-light release film. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below with reference to the accompanying drawings.

[0028] Figure 1 is a schematic structural diagram of the ultra-light release film prepared by the present invention; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The specific embodiments of the present invention will be described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0030] Example 1

[0031] This example provides an antistatic release film, which is prepared by the following steps:

[0032] S1. Add 2 parts of release agent 7755 and 60 parts of solvent DT into a reaction vessel, stir at a speed of 400 r / min, slowly add 0.5 part of antistatic agent YX-120 and 1 part of curing agent 7570, and then add 1 part of catalyst 4000 and continue stirring. The total stirring time is 1.5 h to ensure that all raw materials are fully and evenly mixed;

[0033] S2. Place the uniformly mixed raw materials in a reaction vessel, heat to 80 °C and react for 3.5 h to form a release coating;

[0034] S3. Uniformly coat the prepared release coating on the PET base film by precision coating (slot coating method), precisely control the coating thickness to be 5 μm. After coating, under the cover of a light release protective film, make the release coating closely adhere to the base film by rolling, and compact and form it to obtain an ultra-light release film suitable for silicone.

[0035] The structure of the prepared ultra-light release film is as Figure 1 shown.

[0036] Example 2

[0037] Compared with Example 1, the difference in this example is that "release agent 7755" is changed to "release agent 7765". The specific implementation steps are as follows:

[0038] S1. Add 2 parts of release agent 7765 and 60 parts of solvent DT into the reaction vessel, stir at a speed of 400 r / min. After slowly adding 0.5 part of antistatic agent YX-120 and 1 part of curing agent 7570, add 1 part of catalyst 4000 and continue stirring. The total stirring time is 1.5 h to ensure that all raw materials are fully and evenly mixed;

[0039] S2. Place the uniformly mixed raw materials in the reaction vessel, heat to 80 °C and react for 3.5 h to generate a release coating;

[0040] S3. Uniformly coat the prepared release coating on the PET base film by precision coating (slot coating method), precisely control the coating thickness to be 5 μm. After coating, under the cover of a light release protective film, make the release coating closely adhere to the base film by rolling, and compact and form it to obtain an ultra-light release film suitable for silicone.

[0041] The remaining raw materials and the preparation process are the same as those in Example 1.

[0042] Example 3

[0043] Compared with Example 1, the difference in this example is that "release agent 7755" is changed to "release agent 7775". The specific implementation steps are as follows:

[0044] S1. Add 2 parts of release agent 7775 and 60 parts of solvent DT into the reaction vessel, stir at a speed of 400 r / min. After slowly adding 0.5 part of antistatic agent YX-120 and 1 part of curing agent 7570, add 1 part of catalyst 4000 and continue stirring. The total stirring time is 1.5 h to ensure that all raw materials are fully and evenly mixed;

[0045] S2. Place the uniformly mixed raw materials in the reaction vessel, heat to 80 °C and react for 3.5 h to generate a release coating;

[0046] S3. Uniformly coat the prepared release coating on the PET base film by precision coating (slot coating method), precisely control the coating thickness to be 5 μm. After coating, under the cover of a light release protective film, make the release coating closely adhere to the base film by rolling, and compact it into shape to obtain an ultra-light release film suitable for silicone.

[0047] The remaining raw materials and the preparation process are the same as those in Example 1.

[0048] Example 4

[0049] Compared with Example 1, the difference in this example is that the dosage of the release agent is increased. The specific implementation steps are as follows:

[0050] S1. Add 4 parts of release agent 7755 and 60 parts of solvent DT into the reaction vessel, stir at a speed of 400 r / min, slowly add 0.4 part of antistatic agent YX-120 and 0.8 part of curing agent 7570, then add 0.8 part of catalyst 4000 and continue stirring. The total stirring time is 1.5 h to ensure that all raw materials are fully and evenly mixed;

[0051] S2. Place the evenly mixed raw materials in the reaction vessel, heat to 80 °C and react for 3.5 h to generate a release coating;

[0052] S3. Uniformly coat the prepared release coating on the PET base film by precision coating (slot coating method), precisely control the coating thickness to be 5 μm. After coating, under the cover of a light release protective film, make the release coating closely adhere to the base film by rolling, and compact it into shape to obtain an ultra-light release film suitable for silicone.

[0053] The remaining raw materials and the preparation process are the same as those in Example 1.

[0054] Example 5

[0055] Compared with Example 1, the difference in this example is that the dosage of the release agent is reduced. The specific implementation steps are as follows:

[0056] S1. Add 1.5 parts of release agent 7755 and 60 parts of solvent DT into the reaction vessel, stir at a speed of 400 r / min, slowly add 1 part of antistatic agent YX-120 and 2 parts of curing agent 7570, then add 2 parts of catalyst 4000 and continue stirring. The total stirring time is 1.5 h to ensure that all raw materials are fully and evenly mixed;

[0057] S2. Place the evenly mixed raw materials in the reaction vessel, heat to 80 °C and react for 3.5 h to generate a release coating;

[0058] S3. Uniformly coat the prepared release coating on the PET base film by precision coating (slot coating method), precisely control the coating thickness to be 5 μm. After coating, under the cover of a light release protective film, make the release coating closely adhere to the base film by rolling and compact it into shape to obtain an ultra-light release film suitable for silicone.

[0059] The remaining raw materials and the preparation process are the same as those in Example 1.

[0060] Example 6

[0061] Compared with Example 1, the difference in this example is that "solvent DT, catalyst 4000" is changed to "solvent 2T, catalyst 4200". The specific implementation steps are as follows:

[0062] S1. Add 2 parts of release agent 7755 and 60 parts of solvent 2T into the reaction vessel, stir at a speed of 400 r / min, slowly add 0.5 part of antistatic agent YX - 120 and 1 part of curing agent 7570, then add 1 part of catalyst 4200 and continue stirring. The total stirring time is 1.5 h to ensure that all raw materials are fully and evenly mixed.

[0063] S2. Place the evenly mixed raw materials in the reaction vessel, heat to 80 °C and react for 3.5 h to generate a release coating.

[0064] S3. Uniformly coat the prepared release coating on the PET base film by precision coating (slot coating method), precisely control the coating thickness to be 5 μm. After coating, under the cover of a light release protective film, make the release coating closely adhere to the base film by rolling and compact it into shape to obtain an ultra-light release film suitable for silicone.

[0065] The remaining raw materials and the preparation process are the same as those in Example 1.

[0066] Comparative Example 1

[0067] Compared with Example 1, the difference in this comparative example is that the amount of raw materials is further increased. The specific implementation steps are as follows:

[0068] S1. Add 8 parts of release agent 7755 and 60 parts of solvent DT into the reaction vessel, stir at a speed of 400 r / min, slowly add 1 part of antistatic agent YX - 120 and 2 parts of curing agent 7570, then add 2 parts of catalyst 4000 and continue stirring. The total stirring time is 1.5 h to ensure that all raw materials are fully and evenly mixed.

[0069] S2. Place the evenly mixed raw materials in the reaction vessel, heat to 80 °C and react for 3.5 h to generate a release coating.

[0070] S3. Uniformly coat the prepared release coating on the PET base film by precision coating (slot coating method), precisely control the coating thickness to 5 μm. After coating, under the cover of a light release protective film, make the release coating closely adhere to the base film by rolling and compact it into shape to obtain an ultra-light release film suitable for silicone.

[0071] The other raw materials and the preparation process are the same as those in Example 1.

[0072] Comparative Example 2

[0073] Compared with Example 1, the difference in this comparative example is that no antistatic agent is added. The specific implementation steps are as follows:

[0074] S1. Add 2 parts of release agent 7755 and 60 parts of solvent DT into the reaction vessel, stir at a speed of 400 r / min, slowly add 1 part of curing agent 7570, and then add 1 part of catalyst 4000 and continue stirring. The total stirring time is 1.5 h to ensure that all raw materials are fully and evenly mixed.

[0075] S2. Place the evenly mixed raw materials in the reaction vessel, heat to 80 °C and react for 3.5 h to generate a release coating.

[0076] S3. Uniformly coat the prepared release coating on the PET base film by precision coating (slot coating method), precisely control the coating thickness to 5 μm. After coating, under the cover of a light release protective film, make the release coating closely adhere to the base film by rolling and compact it into shape to obtain an ultra-light release film suitable for silicone.

[0077] The other raw materials and the preparation process are the same as those in Example 1.

[0078] Performance Test

[0079] Perform performance tests on the ultra-light release films prepared in Examples 1 - 6 and Comparative Examples 1 - 2 as follows:

[0080] Initial tearing force (g / in): Stick the release film to the surface of silicone with a viscosity lower than 200 g / in, cut the adhered sample into strips about 25 mm wide and 10 cm long, and use a tensile testing machine with a testing speed of 600 mm / min to test the initial tearing force of the release film.

[0081] Cured tearing force (g / in): After curing the release film at 40 °C for 72 h, stick it to the surface of silicone with a viscosity lower than 200 g / in, cut the adhered sample into strips about 25 mm wide and 10 cm long, and use a tensile testing machine with a testing speed of 600 mm / min to test the cured tearing force of the release film.

[0082] Surface resistance (Ω·m): The resistance of the release film was tested according to the standard of ASTM D257-2014 "Standard Test Method for DC Resistance or Conductance of Insulating Materials".

[0083] Elongation at break (%): The elongation at break of the release film was tested according to the standard of GB / T10654-2001 "Determination of Tensile Strength and Elongation at Break of Porous Elastomeric Materials of High Polymers".

[0084] The results are shown in Table 1:

[0085] Table 1

[0086]

[0087]

[0088] It can be seen from Table 1 that compared with Example 1, Examples 2-6 only differ in the raw material ratio and the change of replaceable raw materials. The test results show that the prepared ultra-light release film has a lower tearing force and good thermal stability (the tearing force is still lower after curing), excellent antistatic performance (surface resistance ≥ 10 7 , up to 10 9 ), and high mechanical strength.

[0089] Compared with Example 1, in Comparative Example 1, after further increasing the dosage of the release agent 7755, the performance of the release film shows a downward trend; compared with Example 1, in Comparative Example 2, after not adding the antistatic agent, the results not only show that the surface resistance decreases, but also the tearing force shows an upward trend. This is because the antistatic agent has good compatibility with the release agent system. When used simultaneously, the prepared release film not only has a good antistatic effect, but also can inhibit the ion migration between the release film and the coating in a high-temperature and high-humidity environment, enhancing the stability of the ultra-light release film.

[0090] In summary, an antistatic release film and its preparation method provided by the present invention have good application prospects in the technical field of screen protection films.

[0091] The above-disclosed are only several specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any changes that can be thought of by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. An antistatic release film, characterized in that, It includes, arranged successively from top to bottom: a protective film, a release coating, and a base film; The protective film is a light release protective film, the base film is made of PET material, and the release coating includes a release agent, a curing agent, an antistatic agent, a catalyst, and a solvent.

2. The antistatic release film according to claim 1, characterized in that, The dosage ratio of the release agent, the curing agent, the antistatic agent, the catalyst, and the solvent is (0.001 - 4):(0.001 - 2):(0.1 - 1):(0.001 - 2):(20 - 80).

3. An antistatic release film according to claim 1, characterized in that, The model of the release agent is one or a combination of several of release agent 7755, release agent 7765, and release agent 7775.

4. An antistatic release film according to claim 1, characterized in that, The model of the curing agent is curing agent 7570.

5. An antistatic release film according to claim 1, wherein The model of the antistatic agent is antistatic agent YX - 120.

6. The antistatic release film according to claim 1, wherein, The model of the catalyst is one or a combination of several of catalyst 4000, catalyst 4200, and catalyst 4500.

7. An antistatic release film according to claim 1, characterized in that, The model of the solvent is one or a combination of several of solvent DT, solvent 2T, and solvent 120#.

8. A method for preparing an antistatic release film according to any one of claims 1-7, characterized in that, It includes the following steps: S1. Add the release agent and the solvent into a reaction vessel and stir. After slowly adding the antistatic agent and the curing agent, add the catalyst and continue stirring to ensure that all raw materials are fully and evenly mixed; S2. Place the evenly mixed raw materials in a reaction vessel and heat them for reaction to generate a release coating; S3. Apply the prepared release coating onto the base film by precision coating. After the coating is completed, under the coverage of the protective film, make the release coating closely adhere to the base film by means of roll pressing and compact it into shape to obtain an ultra - light release film applicable to silicone.

9. The preparation method of an antistatic release film according to claim 8, wherein The stirring speed is 300 - 500 r / min; the stirring time is 1 - 1.5 h; the heating reaction is to heat to 50 - 80 °C and react at this temperature for 3 - 4 h.

10. The preparation method of an antistatic release film according to claim 8, wherein, The precision coating is slit coating or micro - gravure coating; the thickness of the ultra - light release film is 5 - 10 μm.

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