Release agent, release film and preparation method

Abstract

The invention provides a release agent, a release film and a preparation method, and relates to the technical field of release liners.According to the release agent, an organic silicon pressure-sensitive adhesive B with high viscosity and an organic silicon pressure-sensitive adhesive A with low viscosity in a specific proportion are adopted as main components of the release agent; according to the present invention, by introducing the specific ratio of the diamino silicone oil into the release agent, the release film prepared by using the release agent can provide the relatively high adhesion to the graphite sheet, and further introducing the specific ratio of the diamino silicone oil into the release agent, such that the release film prepared by using the release agent can provide the suitable adhesion to the graphite sheet, and the graphite sheet can be subjected to the graphite sheet rolling treatment while the graphite sheet rolling treatment is performed so as to achieve the good graphite sheet rolling effect; and the phenomena of powder falling and tablet falling can be effectively avoided. Meanwhile, the introduction of the diamino silicone oil with a specific ratio is beneficial to reducing the surface energy of the release layer in the release film, so that the release film and the graphite flake can be prevented from generating bubbles in the calendering process. In addition, the release film provided by the invention can be suitable for calendering treatment of graphite flakes with different thicknesses.

Description

Technical Field

[0001] The present invention relates to the technical field of release films, and in particular to a release agent, a release film and a preparation method thereof. Background Art

[0002] In practical applications, graphite sheets are made by high-temperature firing of polyimide film (PI film) materials. During the carbonization process, PI materials need to be fired at high temperatures. During the high-temperature process, the PI film will have certain irregular foaming, making the surface rough. In order to achieve the purpose of use, the graphite sheet needs to be calendered. In this process, a release film with a self-adhesive structure is required. The release film needs to be effectively pressed along with the supported object to make the surface of the artificially fired graphite sheet smoother and more uniform in thickness. Then, the release film follows the graphite sheet into the client, and is cut into different shapes according to the needs of different customers. When in use, the release film is torn off and the graphite sheet is used.

[0003] At present, the bonding force between the release film and the graphite sheet used on the market is not appropriate (too large or too small). When the bonding force is too large, after the graphite sheet is calendered, when the release film is torn off the graphite sheet, the graphite sheet will fall off or even break. When the bonding force is too small, the release film cannot stick to the graphite sheet and the sheet will fall off. In addition, in order to ensure the effect of the calendering treatment, it is necessary that no bubbles are generated between the release film and the graphite sheet during the calendering process. Summary of the invention

[0004] The problem solved by the invention is: how to simultaneously ensure that the release film and the graphite sheet have appropriate bonding force and that no bubbles are generated between the release film and the graphite sheet during the calendering process.

[0005] In order to solve the above problems, the present invention provides a release agent, which comprises, by weight, 30-50 parts of an organic silicone pressure-sensitive adhesive A, 50-70 parts of an organic silicone pressure-sensitive adhesive B, 850-1050 parts of an organic solvent, 0.4-0.6 parts of a diamino silicone oil, 0.9-1.1 parts of an adhesive, 0.9-1.1 parts of a hydrogenated silicone oil, and 1.5-1.7 parts of a catalyst; wherein the viscosity of the organic silicone pressure-sensitive adhesive A is 25000-40000 mPa·s, and the viscosity of the organic silicone pressure-sensitive adhesive B is 45000-65000 mPa·s.

[0006] Optionally, the components include, by weight: 50 parts of organic silicone pressure-sensitive adhesive A, 50 parts of organic silicone pressure-sensitive adhesive B, 850-1050 parts of organic solvent, 0.4-0.6 parts of diamino silicone oil, 1 part of adhesive, 1 part of hydrogenated silicone oil, and 1.6 parts of catalyst.

[0007] Optionally, the organic solvent is composed of ethyl acetate and 120# gasoline in a mass ratio of 4:1.

[0008] The present invention also provides a method for preparing a release film, comprising:

[0009] Step S1, coating the release agent as described above on a substrate to obtain a wet release layer;

[0010] Step S2: drying the wet release layer to form a release layer on the substrate to obtain a release film.

[0011] Optionally, in step S2, the drying treatment of the wet release layer includes: passing the wet release layer through six ovens with temperatures of 110°C, 135°C, 155°C, 155°C, 155°C, and 135°C in sequence at a speed of 60-70m / min, and the length of each oven is 6-8m.

[0012] Optionally, in step S1, the surface density of the wet release layer is 0.35-0.45 g / m 2 .

[0013] Optionally, the substrate has a thickness of 50-150 μm.

[0014] Optionally, the substrate is made of PET.

[0015] Optionally, in step S2, the release layer has a thickness of 1-2 μm.

[0016] The present invention also provides a release film, which is prepared by the above-mentioned method for preparing the release film.

[0017] Compared with the prior art, the release agent provided by the present invention adopts a specific ratio of a silicone pressure-sensitive adhesive B with a higher viscosity and a silicone pressure-sensitive adhesive A with a lower viscosity as the main components of the release agent, so as to ensure that the release film prepared by the release agent has a relatively high adhesion to the graphite sheet, and further introduces a specific ratio of bisamino silicone oil into the release agent, so that the release film prepared by the release agent has a more suitable adhesion to the graphite sheet, and when the release film is used for calendering of the graphite sheet, the occurrence of powder and sheet falling can be effectively avoided. At the same time, the introduction of the specific ratio of bisamino silicone oil is conducive to reducing the surface energy of the release layer in the release film, so that the wettability between the release layer and the graphite sheet is higher, thereby avoiding the generation of bubbles between the release film and the graphite sheet during the calendering process. In addition, the release film provided by the present invention can be applied to the calendering of graphite sheets of different thicknesses. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the process for preparing a release film in an embodiment of the present invention. DETAILED DESCRIPTION

[0019] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be interpreted as being limited to the embodiments described herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0020] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by those skilled in the art to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific implementation methods and are not intended to limit this application;

[0021] The term "including" and its variations used herein are open inclusions, i.e., "including but not limited to"; the term "based on" is "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first" and "second" mentioned in the present invention are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, the meaning of "multiple" is two or more. The viscosity of various substances in the present invention is the viscosity of the substance at 25°C.

[0022] In response to the problems existing in the above-mentioned related technologies, the present embodiment provides a release agent provided by the present invention, wherein the components thereof include, by weight: 30-50 parts of silicone pressure-sensitive adhesive A, 50-70 parts of silicone pressure-sensitive adhesive B, 850-1050 parts of organic solvent, 0.4-0.6 parts of diamino silicone oil, 0.9-1.1 parts of adhesive, 0.9-1.1 parts of hydrogen-containing silicone oil, and 1.5-1.7 parts of catalyst; wherein the viscosity of the silicone pressure-sensitive adhesive A is 25000-40000 mPa·s, and the viscosity of the silicone pressure-sensitive adhesive B is 45000-65000 mPa·s.

[0023] The release agent provided in the embodiment of the present invention adopts a specific ratio of a silicone pressure-sensitive adhesive B with a higher viscosity and a silicone pressure-sensitive adhesive A with a lower viscosity as the main components of the release agent, so as to ensure that the release film prepared by the release agent has a relatively high adhesive force on the graphite sheet, and further introduces a specific ratio of bisamino silicone oil into the release agent, so that the release film prepared by the release agent has a more suitable adhesive force on the graphite sheet, and when the release film is used for calendering of the graphite sheet, the occurrence of powder and sheet falling can be effectively avoided. At the same time, the introduction of the specific ratio of bisamino silicone oil is conducive to reducing the surface energy of the release layer in the release film, so that the wettability between the release layer and the graphite sheet is higher, thereby avoiding the generation of bubbles between the release film and the graphite sheet during the calendering process. In addition, graphite sheets of different thicknesses often have large differences, and a release film often cannot be well matched, resulting in the need to stop the production to adjust parameters or replace the release film, which greatly reduces the yield. The release film provided in the embodiment of the present invention can be applied to the calendering of graphite sheets of different thicknesses.

[0024] In some embodiments of the present invention, preferably, the components include, by weight: 50 parts of silicone pressure-sensitive adhesive A, 50 parts of silicone pressure-sensitive adhesive B, 850-1050 parts of organic solvent, 0.4-0.6 parts of diamino silicone oil, 1 part of adhesive, 1 part of hydrogenated silicone oil, and 1.6 parts of catalyst.

[0025] In some embodiments of the present invention, the catalyst is a platinum catalyst.

[0026] In some embodiments of the present invention, the organic solvent is composed of ethyl acetate and 120# gasoline in a mass ratio of 4:1.

[0027] like Figure 1 As shown, an embodiment of the present invention further provides a method for preparing a release film, comprising:

[0028] Step S1, coating the release agent as described above on a substrate to obtain a wet release layer;

[0029] Step S2: drying the wet release layer to form a release layer on the substrate to obtain a release film.

[0030] In some embodiments of the present invention, in step S2, the drying treatment of the wet release layer includes: passing the wet release layer through six ovens with temperatures of 110°C, 135°C, 155°C, 155°C, 155°C, and 135°C in sequence at a speed of 60-70m / min, and the length of each oven is 6-8m.

[0031] In some embodiments of the present invention, in step S1, the surface density of the wet release layer is 0.35-0.45 g / m 2 .

[0032] In some embodiments of the present invention, the thickness of the substrate is 50-150 μm.

[0033] In some embodiments of the present invention, the substrate is made of PET.

[0034] In some embodiments of the present invention, in step S2, the thickness of the release layer is 1-2 μm.

[0035] The embodiment of the present invention further provides a release film, which is prepared by the method for preparing the release film as described above.

[0036] The present invention is further described below in conjunction with specific examples. It should be noted that, in the examples of the present invention, the silicone pressure-sensitive adhesive A is a product of ELKEM PSA3060 produced by Elkem Silicones (Shanghai) Co., Ltd., and its viscosity is 32000mpa·s; the silicone pressure-sensitive adhesive B is a product of ELKEM PSA1057 produced by Elkem Silicones (Shanghai) Co., Ltd., and its viscosity is 55000mpa·s; the bisamino silicone oil is a product of OFX-8040 produced by Dow Corning; the hydrogen-containing silicone oil is a product of CAT-7211 produced by Elkem Silicones (Shanghai) Co., Ltd.; the adhesive is a product of AD-28 produced by Elkem Silicones (Shanghai) Co., Ltd.; and the platinum catalyst is a product of CAT-PL-85 produced by Elkem Silicones (Shanghai) Co., Ltd.

[0037] Example 1

[0038] A1. Mix 50 parts of silicone pressure-sensitive adhesive A, 50 parts of silicone pressure-sensitive adhesive B and 950 parts of organic solvent in parts by weight, then add 0.6 parts of diamino silicone oil, 1 part of hydrogen-containing silicone oil, 1 part of adhesive and 1.6 parts of platinum catalyst in sequence, mix well, and obtain a release agent; wherein the organic solvent is composed of ethyl acetate and 120# gasoline in a mass ratio of 4:1.

[0039] A2. Coat the release agent on a PET substrate to obtain a wet release layer; pass the wet release layer through six ovens with temperatures of 110° C., 135° C., 155° C., 155° C., 155° C., and 135° C. at a speed of 60 m / min to form a release layer on the PET substrate to obtain a release film; wherein the length of each oven section is 6 m, the thickness of the PET substrate is 100 μm, and the thickness of the release layer is 1.5 μm.

[0040] Example 2

[0041] The difference from Example 1 is that step A1 is: in parts by weight, 50 parts of silicone pressure-sensitive adhesive A, 50 parts of silicone pressure-sensitive adhesive B and 950 parts of organic solvent are mixed evenly, and then 0.5 parts of diamino silicone oil, 1 part of hydrogen-containing silicone oil, 1 part of adhesive and 1.6 parts of platinum catalyst are added in sequence, mixed evenly, and a release agent is obtained; wherein the organic solvent is composed of ethyl acetate and 120# gasoline in a mass ratio of 4:1.

[0042] Example 3

[0043] The difference from Example 1 is that step A1 is: by weight, 50 parts of silicone pressure-sensitive adhesive A, 50 parts of silicone pressure-sensitive adhesive B and 950 parts of organic solvent are mixed evenly, and then 0.4 parts of diamino silicone oil, 1 part of hydrogen-containing silicone oil, 1 part of adhesive and 1.6 parts of platinum catalyst are added in sequence, mixed evenly, and a release agent is obtained; wherein the organic solvent is composed of ethyl acetate and 120# gasoline in a mass ratio of 4:1.

[0044] Comparative Example 1

[0045] The difference from Example 1 is that step A1 is: by weight, 50 parts of silicone pressure-sensitive adhesive A, 50 parts of silicone pressure-sensitive adhesive B and 950 parts of organic solvent are mixed evenly, and then 1 part of hydrogenated silicone oil, 1 part of adhesive and 1.6 parts of platinum catalyst are added in sequence, mixed evenly, and a release agent is obtained; wherein the organic solvent is composed of ethyl acetate and 120# gasoline in a mass ratio of 4:1.

[0046] Comparative Example 2

[0047] The difference from Example 1 is that step A1 is: in parts by weight, 50 parts of silicone pressure-sensitive adhesive A, 50 parts of silicone pressure-sensitive adhesive B and 950 parts of organic solvent are mixed evenly, and then 1.0 part of diamino silicone oil, 1 part of hydrogen-containing silicone oil, 1 part of adhesive and 1.6 parts of platinum catalyst are added in sequence, mixed evenly, and a release agent is obtained; wherein the organic solvent is composed of ethyl acetate and 120# gasoline in a mass ratio of 4:1.

[0048] Comparative Example 3

[0049] The difference from Example 1 is that step A1 is: in parts by weight, 50 parts of silicone pressure-sensitive adhesive A, 50 parts of silicone pressure-sensitive adhesive B and 950 parts of organic solvent are mixed evenly, and then 1.2 parts of diamino silicone oil, 1 part of hydrogen-containing silicone oil, 1 part of adhesive and 1.6 parts of platinum catalyst are added in sequence, mixed evenly, and a release agent is obtained; wherein the organic solvent is composed of ethyl acetate and 120# gasoline in a mass ratio of 4:1.

[0050] Experimental example

[0051] The release films prepared in Examples 1-3 and Comparative Examples 1-3 were tested for 24H release force, 24H release force of a 17μm thick graphite sheet, appearance of a 17μm thick graphite sheet, 24H release force of a 25μm thick graphite sheet, and appearance of a 25μm thick graphite sheet. The results are shown in Table 1. As can be seen from Table 1, compared with Comparative Examples 1-3, the release films prepared in Examples 1-3 have a better effect when calendering graphite sheets, and no abnormal conditions such as powder loss, sheet loss, bubbles, and wrinkles during rolling occur. This indicates that the release films prepared in Examples 1-3 have a suitable adhesive force with the graphite sheets, and no bubbles are generated between the release films and the graphite sheets during the calendering process. In addition, the release films prepared in Examples 1-3 can be used for calendering graphite sheets of two different specifications, 17μm and 25μm in thickness.

[0052] Table 1

[0053]

[0054]

[0055] It should be noted that in Table 1, "24H release force (17μm)" refers to the 24H release force of the release film attached to a 17μm thick graphite sheet, "calendering apparent condition (17μm)" refers to the apparent condition of the release film calendering a 17μm thick graphite sheet, "24H release force (25μm)" refers to the 24H release force of the release film attached to a 25μm thick graphite sheet, and "calendering apparent condition (25μm)" refers to the apparent condition of the release film calendering a 25μm thick graphite sheet. The units of the release forces involved in Table 1 are all gf / 25mm.

[0056] The relevant performance testing methods involved in the present invention are as follows:

[0057] (1) 24H release force test method of release film: First, tesa TM The 7475 tape is attached to the release surface of the release film to be tested, and after being rolled back and forth three times with a 2KG pressure roller, it is cut to obtain a 25mm*130mm specimen; the specimen is placed at room temperature for 24 hours and then attached to a steel plate with adhesive. The 7475 tape is peeled off at an angle of 180° and a peeling speed of 300mm / min using a tensile testing machine. The reading of the tensile testing machine is the 24H release force.

[0058] (2) 24-hour release force test method of release film attached to 17 μm thick graphite sheet: first, attach the release film to be tested to the 17 μm thick graphite sheet, roll it back and forth three times with a 2KG roller, and then cut it into 25mm*130mm specification specimens; place the specimens at room temperature for 24 hours and then attach them to a steel plate with glue. Use a tensile testing machine to peel off the release film at an angle of 180° and a peeling speed of 300mm / min. The reading of the tensile testing machine is the 24-hour release force of the release film attached to the 17 μm thick graphite sheet.

[0059] (3) 24-hour release force test method of release film attached to 25 μm thick graphite sheet: first, attach the release film to be tested to the 25 μm thick graphite sheet, roll it back and forth three times with a 2KG roller, and then cut it into 25mm*130mm specification specimens; place the specimens at room temperature for 24 hours and then attach them to a steel plate with glue. Use a tensile testing machine to peel off the release film at an angle of 180° and a peeling speed of 300mm / min. The reading of the tensile testing machine is the 24-hour release force of the release film attached to the 25 μm thick graphite sheet.

[0060] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A release agent, characterized in that: The components include, by weight: 30-50 parts of organic silicone pressure-sensitive adhesive A, 50-70 parts of organic silicone pressure-sensitive adhesive B, 850-1050 parts of organic solvent, 0.4-0.6 parts of diamino silicone oil, 0.9-1.1 parts of adhesive, 0.9-1.1 parts of hydrogen-containing silicone oil, and 1.5-1.7 parts of catalyst; wherein the viscosity of the organic silicone pressure-sensitive adhesive A is 25000-40000 mpa·s, and the viscosity of the organic silicone pressure-sensitive adhesive B is 45000-65000 mpa·s.

2. The release agent according to claim 1, characterized in that The components include, by weight: 50 parts of organic silicone pressure-sensitive adhesive A, 50 parts of organic silicone pressure-sensitive adhesive B, 850-1050 parts of organic solvent, 0.4-0.6 parts of diamino silicone oil, 1 part of adhesive, 1 part of hydrogen-containing silicone oil, and 1.6 parts of catalyst.

3. The release agent according to claim 1, characterized in that The organic solvent is composed of ethyl acetate and 120# gasoline in a mass ratio of 4:

1.

4. A method for preparing a release film, characterized in that: include: Step S1, coating the release agent according to any one of claims 1 to 3 on a substrate to obtain a wet release layer; Step S2: drying the wet release layer to form a release layer on the substrate to obtain a release film.

5. The method for preparing a release film according to claim 4, characterized in that: In the step S2, the drying treatment of the wet release layer includes: passing the wet release layer through six ovens with temperatures of 110°C, 135°C, 155°C, 155°C, 155°C, and 135°C in sequence at a speed of 60-70 m / min, and the length of each oven is 6-8 m.

6. The method for preparing a release film according to claim 4, characterized in that: In step S1, the surface density of the wet release layer is 0.35-0.45 g / m 2 .

7. The method for preparing a release film according to claim 4, characterized in that: The thickness of the substrate is 50-150 μm.

8. The method for preparing a release film according to claim 4, characterized in that: The material of the substrate is PET.

9. The method for preparing a release film according to claim 4, characterized in that: In the step S2, the thickness of the release layer is 1-2 μm.

10. A release film, characterized in that: The release film is prepared by the method for preparing the release film according to any one of claims 4 to 9.

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