Antistatic light release film for OCA optical adhesive coating and preparation method thereof

Abstract

The invention provides an antistatic light release film for coating OCA optical adhesive, comprising polysiloxane, a curing agent, an anchoring agent, a catalyst, a leveling agent, a defoaming agent, silicon micropowder and an organic mixed solvent. A coating release coating liquid prepared by mixing the above raw materials is coated on an electrostatic coating, thereby overcoming the defects of large release force and low residual bonding rate in the prior art. Polysiloxane, an anchoring agent, a leveling agent and a defoaming agent that cooperate with silicon micropowder are used in the release agent to provide a more uniform release force for the release film, effectively improve the adsorption caused by an increase in the light release coating amount, and on the other hand, enhance the wear resistance of the release layer, reduce the appearance defects such as uneven coating of the OCA optical adhesive and glue residue caused by surface scratches, and effectively improve the yield of the product.

Description

Technical Field

[0001] The present invention relates to the technical field of release films, and in particular to an antistatic light release film for coating an OCA optical adhesive and a preparation method thereof. Background Art

[0002] The main function of OCA release film is to provide release effect during the production and use of OCA optical adhesive, protect OCA optical adhesive from damage, and ensure that the needs of high-speed production are met. It is usually used in die-cutting processing, gluing, waterproof material isolation, silicone products and other fields. In the production process of OCA optical adhesive, release film plays a key role. OCA optical adhesive is a high-transparency double-sided laminating tape without substrate. It has a layer of release film on the upper and lower bottom layers. These release films not only protect OCA optical adhesive from damage during the production process, but also ensure that the needs of high-speed production are met. In addition, the use of OCA release film also improves the cleanliness of OCA optical adhesive, making it an ideal material in the manufacture of electronic devices such as touch screens. In general, OCA release film ensures the stability and quality of OCA optical adhesive during high-speed production through its release effect and protective effect, and is one of the indispensable materials in the modern electronic manufacturing industry.

[0003] Invention patent CN117924775A provides a solid OCA coated release film and a preparation method thereof. The addition of nano titanium dioxide solves the problems of low light transmittance and high haze of the release film. Moist water vapor is easily condensed on the surface of the release film, resulting in a mist-like appearance defect. However, the release force of the release film is less than 20g / 25mm, and the residual adhesion rate is greater than 80%. For the OCA coating process, there is a risk of glue pulling and silicon transfer.

[0004] Invention patent CN115124749A provides an antistatic optical release film for OCA optical adhesive and a preparation method thereof. By setting an antistatic layer and an antistatic release layer with conductive particles, it has a dual antistatic effect and reduces the film tearing voltage. However, the conductive particles added to the antistatic release film are conductive silver powder, which is costly and not suitable for industrial production.

[0005] Therefore, the present invention aims to provide an antistatic light release film for OCA optical adhesive coating and a preparation method thereof, so as to solve the problems raised in the above-mentioned background technology. Summary of the invention

[0006] In order to overcome the shortcomings of the prior art, an object of the present invention is to provide an antistatic light release film for OCA optical adhesive coating, comprising a substrate layer, an antistatic coating, and a release coating; the antistatic coating is coated with a solution containing an antistatic agent; the release coating comprises the following raw materials calculated in parts by mass: 15-30 parts of polysiloxane; 0.1-0.5 parts of a curing agent; 0.1-0.3 parts of an anchoring agent; 0.2-0.5 parts of a catalyst; 0.01-0.05 parts of a leveling agent; 0.01-0.05 parts of a defoaming agent; 0.1-0.5 parts of silicon micropowder; and 80-100 parts of an organic mixed solvent.

[0007] The polysiloxane is one or more of hydrogen-containing polysiloxane, hydroxy polysiloxane, polydimethylsiloxane, polyvinylsiloxane, and organically modified polysiloxane.

[0008] The organic modified polysiloxane is polyether modified polysiloxane, polyether modified polydimethylsiloxane, polyether modified trisiloxane, or epoxy modified polysiloxane.

[0009] The anchoring agent is an organic silicon compound, including a functionalized organic siloxane compound containing vinyl and epoxy groups; or the anchoring agent is a polymeric anchoring agent, including oligomeric alkenyl siloxane and / or high molecular weight epoxy polysiloxane. The anchoring agent can react with the crosslinking agent in the release agent and interact with the substrate to improve the adhesion without affecting the release force and stability.

[0010] The catalyst is one of a platinum catalyst and an organic tin catalyst.

[0011] The silicon powder is one or more of crystalline silicon powder and molten silicon powder.

[0012] The organic mixed solvent is a mixed solvent of two or more of toluene, ethyl acetate, n-butyl acetate, acetone, isoheptane and n-hexane.

[0013] The leveling agent is BYK-348 or BYK-349.

[0014] The defoaming agent is methyl fluorosilicone oil and / or amino silicone oil.

[0015] A second object of the present invention is to provide a method for preparing an ultra-light release film for coating an OCA optical adhesive, comprising the following steps: Step 101: coating a layer of antistatic coating on the corona surface of the single-sided corona-treated PET substrate to form a single-sided antistatic PET film; Step 102: Weigh polysiloxane, silicon powder and organic mixed solvent, mix and stir for 20 minutes, disperse the mixed solution at 1200 r / min for 4 hours to obtain a uniformly dispersed mixed solution A; Step 103: weigh an anchoring agent, a curing agent, a leveling agent, a defoaming agent, and a catalyst, add them to the mixed solution A, and stir at 300 r / min for 30 minutes to obtain a release coating solution B; Step 104: Apply the coating release coating liquid B prepared in step 103 to the antistatic surface of the single-sided antistatic PET film prepared in step 101, and bake the release film at 130-150° C. for 5-10 minutes to completely evaporate the organic solvent, thereby finally obtaining an antistatic release film.

[0016] The coating amount of the release coating liquid B in step 104 is 0.5-1.5 g / m 2 .

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: the antistatic light release film for OCA optical adhesive coating of the present invention overcomes the defects of the prior art that the release force is too large and the residual bonding rate is low. Silicon micropowder with a smooth surface is added to the release agent. SiO2 silicon micropowder is highly dispersed and compatible in the coating liquid, and interacts with polysiloxane to form a very stable structure, which helps to improve the microstructure of the release coating, reduce the defects on the coating surface, provide a more uniform release force for the release coating, and improve the adhesion of the release; in addition, the addition of SiO2 silicon micropowder helps to improve the antistatic performance of the release film, and effectively improves the adsorption caused by the increase in the light release coating amount. Silicon micropowder provides a more uniform release force for the release film. On the one hand, it can effectively improve the adsorption caused by the increase in the light release coating amount. On the other hand, it can enhance the wear resistance of the release layer, reduce the appearance defects such as uneven coating of OCA optical adhesive and glue residue caused by surface scratches, and effectively improve the yield of the product. Ultra-high molecular weight polysiloxane can promote the formation of a continuous PEI-rich phase by blending polyether-modified polydimethylsiloxane and hydrogen-containing polysiloxane, and synergistically significantly improve the heat resistance, weather resistance and chemical stability of the coating, meeting the requirements for relatively stable mechanical properties of the coating. When used in combination with BYK-348, methyl fluorosilicone oil and amino silicone oil, and combined with silicon micropowder, it can further reduce the microscopic unevenness on the coating surface, improve the smoothness and glossiness of the coating, and help improve the transmittance, haze and appearance, meeting the release performance requirements of the light release film, while maintaining stable, wear-resistant mechanical properties and stable light peeling performance under high or low temperature fluctuations.

[0018] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, some embodiments are described in detail below. The specific implementation of the present invention is given in detail by the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 This is a schematic diagram of the structure of an antistatic light release film for OCA optical adhesive coating of the present invention: Among them, 1-substrate layer, 2-antistatic coating, 3-release coating. DETAILED DESCRIPTION

[0020] The present invention is further described in detail below in conjunction with the accompanying drawings, and the aforementioned and other purposes, features, aspects and advantages of the present invention will become more obvious, so that those skilled in the art can implement it with reference to the text of the specification. In the accompanying drawings, for the sake of clarity, the shapes and sizes can be enlarged, and the same reference numerals will be used in all figures to indicate the same or similar parts. In the following description, words such as center, thickness, height, length, front, back, rear, left, right, top, bottom, upper, lower, etc. are based on the orientation or position relationship shown in the accompanying drawings. In particular, "height" is equivalent to the size from top to bottom, "width" is equivalent to the size from left to right, and "depth" is equivalent to the size from front to back. These relative terms are for the convenience of explanation and are generally not intended to require specific orientation. Terms related to attachment, connection, etc. (for example, "connection" and "attachment") refer to the relationship between these structures directly or indirectly fixed or attached to each other through intermediate structures, and movable or rigid attachment or relationship, unless otherwise explicitly stated.

[0021] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0022] like Figure 1 As shown, an antistatic light release film for coating OCA optical adhesive comprises a substrate layer 1, an antistatic coating 2, and a release coating 3. Among them, the substrate layer 1 has a thickness of 50 um, the antistatic coating 2 has a thickness of 10 um, the antistatic coating adopts the coating of the antistatic layer of the applicant's prior application 202010031645.7, and the release coating 3 has a coating thickness of 15 um. The release coating 2 comprises the following raw materials calculated by mass: 15-30 mass parts of polysiloxane; 0.1-0.5 mass parts of curing agent; 0.1-0.3 mass parts of anchoring agent; 0.2-0.5 mass parts of catalyst; 0.01-0.05 mass parts of leveling agent; 0.01-0.05 mass parts of defoaming agent; 0.1-0.5 mass parts of silicon powder; 80-100 mass parts of organic mixed solvent.

[0023] In some embodiments, the polysiloxane is one or more of hydrogen-containing polysiloxane, hydroxyl polysiloxane, polydimethylsiloxane, polyvinylsiloxane, and organically modified polysiloxane; preferably, the organically modified polysiloxane is polyether-modified polysiloxane, polyether-modified polydimethylsiloxane, polyether-modified trisiloxane, or epoxy-modified polysiloxane.

[0024] In some embodiments, the anchoring agent is an organosilicon compound, including a functionalized organosiloxane compound containing vinyl and epoxy groups; preferably, a polymeric anchoring agent is used, including oligomeric alkenyl siloxane and / or high molecular weight epoxy polysiloxane. The anchoring agent can react with the crosslinking agent in the release agent and interact with the substrate to improve adhesion without affecting the release force and stability.

[0025] In some embodiments, the catalyst is a platinum catalyst or an organic tin catalyst.

[0026] In some embodiments, the silicon powder is one or more of crystalline silicon powder and fused silicon powder.

[0027] In some embodiments, the organic mixed solvent is a mixed solvent of two or more of toluene, ethyl acetate, n-butyl acetate, acetone, isoheptane, and n-hexane. The leveling agent is BYK-348 or BYK-349. The defoaming agent is methyl fluorosilicone oil and / or amino silicone oil. A second object of the present invention is to provide a method for preparing an ultra-light release film for coating an OCA optical adhesive, comprising the following steps: Step 101: coating a layer of antistatic coating on the corona surface of the single-sided corona-treated PET substrate to form a single-sided antistatic PET film; Step 102: Weigh polysiloxane, silicon powder and an organic mixed solvent, mix and stir for 20 minutes, and disperse the mixed solution at 1200 r / min for 4 hours to obtain a uniformly dispersed mixed solution A; Step 103: weigh an anchoring agent, a curing agent, a leveling agent, a defoaming agent, and a catalyst, add them to the mixed solution A, and stir at 300 r / min for 30 minutes to obtain a release coating solution B; Step 104: Apply the coating release coating liquid B prepared in step 103 to the antistatic surface of the single-sided antistatic PET film prepared in step 101, and bake the release film at 130-150° C. for 5-10 minutes to completely evaporate the organic solvent, thereby finally obtaining an antistatic release film.

[0028] The coating amount of the release agent in step 104 is 0.5-1.5 g / m 2 .

[0029] The relevant test methods are as follows: The test method of the antistatic light release film for OCA optical adhesive coating of the present invention is as follows: Release force test / residual adhesion rate: Tested in accordance with the national standard GB / T25256-2010 "Test method for 180° peeling force and residual adhesion rate of optical functional film release film"; Resistance value test: measured in accordance with the national standard GB / T 33375-2016 "Test method for electrostatic properties of adhesive tapes"; Adhesion test: Cut the prepared release film into samples with a size of 10cm*10cm, put them into boiling water for 2 hours, take out the samples, cool them to room temperature, and observe whether the release layer peels off, falls off, or bubbles. Light transmittance / haze test: Tested in accordance with the national standard GB / T 2410-2008 "Determination of light transmittance and haze of transparent plastics"; The following table shows the release layer component data of different embodiments and comparative examples.

[0030]

[0031] The following table lists the test items and data of the release films of the above embodiments and comparative examples.

[0032]

[0033] The above is a preferred embodiment of the present invention. The ultra-light release film for OCA optical adhesive coating obtained by the same or similar steps as the above embodiments of the present invention is within the scope of patent protection of the present invention.

[0034] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the embodiments shown here.

Claims

1. An antistatic light release film for coating OCA optical adhesive, comprising a substrate layer, an antistatic coating, and a release coating; the antistatic coating is coated with a solution containing an antistatic agent; the release coating comprises the following raw materials calculated by mass: 15-30 parts of polysiloxane; 0.1-0.5 parts of a curing agent; 0.1-0.3 parts of an anchoring agent; 0.2-0.5 parts of a catalyst; 0.01-0.05 parts of a leveling agent; 0.01-0.05 parts of a defoaming agent; 0.1-0.5 parts of silicon powder; and 80-100 parts of an organic mixed solvent.

2. The antistatic light release film for coating OCA optical adhesive according to claim 1, characterized in that: The polysiloxane is one or more of hydrogen-containing polysiloxane, hydroxy polysiloxane, polydimethylsiloxane, polyvinylsiloxane, and organically modified polysiloxane.

3. The antistatic light release film for coating OCA optical adhesive according to claim 2, characterized in that: The organic modified polysiloxane is one or more of polyether modified polysiloxane, polyether modified polydimethylsiloxane, polyether modified trisiloxane and epoxy modified polysiloxane.

4. The antistatic light release film for coating OCA optical adhesive according to claim 1, characterized in that: The anchoring agent is an organic silicon compound, including a functionalized organic siloxane compound containing vinyl and epoxy groups; or the anchoring agent is a polymeric anchoring agent, including one of oligomeric alkenyl siloxane and / or high molecular weight epoxy polysiloxane.

5. The antistatic light release film for coating OCA optical adhesive according to claim 1, characterized in that: The catalyst is one of a platinum catalyst and an organic tin catalyst.

6. The antistatic light release film for coating OCA optical adhesive according to claim 1, characterized in that: The silicon powder is one or more of crystalline silicon powder and molten silicon powder.

7. The antistatic light release film for coating OCA optical adhesive according to claim 1, characterized in that: The organic mixed solvent is a mixed solvent of two or more of toluene, ethyl acetate, n-butyl acetate, acetone, isoheptane and n-hexane; the leveling agent is BYK-348 or BYK-349; and the defoaming agent is methyl fluorosilicone oil and / or amino silicone oil.

8. A method for preparing an antistatic light release film for coating OCA optical adhesive, characterized in that: The following steps are involved: Step 101: coating a layer of antistatic coating on the corona surface of the single-sided corona-treated PET substrate to form a single-sided antistatic PET film; Step 102: Weigh polysiloxane, silicon powder and an organic mixed solvent, mix and stir for 20 minutes, and disperse the mixed solution at 1200 r / min for 4 hours to obtain a uniformly dispersed mixed solution A; Step 103: weigh an anchoring agent, a curing agent, a leveling agent, a defoaming agent, and a catalyst, add them to the mixed solution A, and stir at 300 r / min for 30 minutes to obtain a release coating solution B; Step 104: Apply the coating release coating liquid B prepared in step 103 to the antistatic surface of the single-sided antistatic PET film prepared in step 101, and bake the release film at 130-150°C for 5-10 minutes to completely evaporate the organic solvent, and finally obtain an antistatic light release film for OCA optical adhesive coating.

9. The method for preparing the antistatic light release film for coating OCA optical adhesive according to claim 8, characterized in that: The coating amount of the release coating liquid B in step 104 is 0.5-1.5 g / m 2 .

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