PET double-layer antistatic release film

Abstract

The invention discloses a PET (polyethylene terephthalate) double-layer antistatic release film, which belongs to the technical field of antistatic release films and comprises a PET base material layer, two antistatic coatings and a release coating, the antistatic coatings are respectively laminated on two side surfaces of the PET base material layer, and the release coating is laminated on the other side surface of one antistatic coating; the antistatic coating comprises the following components: polyethylene, carbon nanotubes, toluene and a dispersing agent; and the release coating comprises the following components: organic silicon resin, methylbenzene and a platinum catalyst. The PET double-layer antistatic release film can still keep good antistatic performance after being stored for 4 months; therefore, the PET double-layer antistatic release film provided by the invention solves the technical problem of how to improve the problem of poor antistatic effect durability of the existing antistatic release film.

Description

Technical Field

[0001] The present invention relates to the technical field of antistatic release films, and particularly to a PET double-layer antistatic release film. Background Art

[0002] Release film materials refer to films that do not have adhesiveness or have slight adhesiveness when contacted with certain special materials under certain conditions. The release film of polyethylene terephthalate, namely Polyethylene terephthalate, abbreviated as PET, is a release film with a PET original film as the supporting substrate. The surface of the substrate is treated to make it have an ultra-low surface energy, and has advantages such as high light transmittance, low haze, strong tensile resistance, stability, and easy peeling. Therefore, it has a wide range of applications in industries such as electronics, die-cutting and stamping processing, printed circuit boards, packaging materials, adhesive products, and waterproof materials.

[0003] Furthermore, due to the interactions such as peeling, mutual friction, and extrusion that occur during the actual application process of the release film material, charges with different characteristics will accumulate on its surface. The electrostatic insulation property of the substrate leads to electrostatic accumulation, which will cause problems such as the failure of the release film to peel from the adhesive layer or the contamination of the product surface. A feasible approach is to make the release film material have antistatic characteristics by adding antistatic materials.

[0004] Based on this, the Chinese patent document with the publication number CN111716832A discloses an antistatic silicone release film, which provides excellent antistatic characteristics without generating static side effects when the film is removed from the adhesive, obtains excellent adhesion between the cured layer and the substrate, and the cured layer has a high degree of crosslinking, thus realizing stable release characteristics. This antistatic silicone release film includes: a base film; and a cured layer of an antistatic silicone release composition provided at least on one surface of the base film, wherein the cured layer includes an antistatic region and a silicone release region, and the strength ratio (Si- / S-) between the sulfide ions showing antistatic characteristics and the silicon ions showing silicone release characteristics in the antistatic region is less than 1, and the strength ratio in the silicone release region is greater than 10.

[0005] However, the antistatic release films disclosed in the prior art still have the technical problem of poor persistence of the antistatic effect. Specifically, the existing antistatic methods usually include: internally adding anionic compounds, depositing metal compounds, coating conductive inorganic particles, coating low-molecular ionic compounds, coating conductive polymers, etc. Based on these antistatic technologies, producing an antistatic release film by using metal in a silicone composition is a common method. However, during the use process in a long-term lamination occasion, the silicon-containing component is likely to migrate from the release film to the surface of the adhered article, thereby causing product surface contamination or affecting the later antistatic persistence. Summary of the Invention

[0006] Based on this, it is necessary to provide a PET double-layer antistatic release film to address the technical problem of the poor persistence of the antistatic effect in the antistatic release film disclosed in the prior art.

[0007] A PET double-layer antistatic release film includes: a PET substrate layer, two antistatic coatings, and a release coating; one antistatic coating is laminated on each of the two side surfaces of the PET substrate layer, and the release coating is laminated on the other side surface of one of the antistatic coatings; the components of the antistatic coating include: polyethylene, carbon nanotubes, toluene, and a dispersant.

[0008] Specifically, by mass, the components of the antistatic coating include: the feeding amount of low-density polyethylene LDPE is 6 - 8 parts, the feeding amount of single-walled carbon nanotubes SWCNTs is 3 - 4 parts, toluene is 300 - 400 parts, the dispersant BYK-2155 is 3 - 4 parts, and the dispersant BYK-9076 is 0.4 - 0.6 parts.

[0009] Specifically, by mass, the components of the antistatic coating include: the feeding amount of low-density polyethylene LDPE is 8 parts, the feeding amount of single-walled carbon nanotubes SWCNTs is 4 parts, toluene is 400 parts, the dispersant BYK-2155 is 4 parts, and the dispersant BYK-9076 is 0.6 parts.

[0010] Specifically, in the components of the antistatic coating, the carbon nanotubes used are modified carbon nanotubes, which are oxidized with concentrated nitric acid, sulfuric acid, or potassium permanganate to introduce carboxyl functional groups on the surface of the carbon nanotubes.

[0011] Specifically, in the components of the antistatic coating, polyethylene and carbon nanotubes are first processed into a polyethylene-carbon nanotube composite material, and then mixed with toluene and a dispersant to form the antistatic coating.

[0012] Specifically, in the components of the release coating, by mass, each component is: silicone resin 5 - 8 parts, toluene 5 - 8 parts, and platinum catalyst 0.1 - 0.15 parts.

[0013] Specifically, in the components of the release coating, by mass, each component is: silicone resin 5 parts, toluene 5 parts, and platinum catalyst 0.1 part.

[0014] In summary, the present invention provides a PET double-layer antistatic release film, which includes: a PET base material layer 1, two antistatic coating layers 2, and a release coating layer 3; one antistatic coating layer 2 is laminated on each of the two side surfaces of the PET base material layer 1, and the release coating layer 3 is laminated on the other side surface of one of the antistatic coating layers 2; the components of the antistatic coating layer 2 include: polyethylene, carbon nanotubes, toluene, and a dispersant; the components of the release coating layer 3 include: silicone resin, toluene, and a platinum catalyst. This PET double-layer antistatic release film can still maintain good antistatic performance after being stored for 4 months; thus, the PET double-layer antistatic release film of the present invention solves the technical problem of how to improve the poor durability of the antistatic effect existing in the existing antistatic release film. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic structural diagram of a PET double-layer antistatic release film of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be made with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0017] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

[0018] 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 the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0019] In the present invention, unless otherwise clearly specified or limited, the terms "installed", "connected", "connected to", "fixed", etc. shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] In the present invention, unless otherwise clearly specified or limited, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or simply means that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower horizontal height than the second feature.

[0021] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation.

[0022] Please refer to Figure 1 , a PET double-layer antistatic release film of the present invention, which comprises: a PET substrate layer 1, two antistatic coatings 2 and a release coating 3; one antistatic coating 2 is laminated on each of the two side surfaces of the PET substrate layer 1, and a release coating 3 is laminated on the other side surface of one of the antistatic coatings 2; the components of the antistatic coating 2 include: polyethylene, carbon nanotubes, toluene and a dispersant.

[0023] Specifically, in a PET double-layer antistatic release film of the present invention, an antistatic coating 2 is disposed on each of the two side surfaces of a PET substrate layer 1, thereby forming a double-layer antistatic structure to improve the electrostatic accumulation on the two side surfaces of the PET film layer due to its insulating property. When in use, due to interactions such as peeling, mutual friction, and extrusion, different characteristics of charges will accumulate on its surface, causing static electricity. And, a release coating 3 is further disposed on the side surface of one of the antistatic coatings 2 to facilitate the release function of the release coating 3.

[0024] Further, in the technical solution of a PET double-layer antistatic release film of the present invention, the components of the antistatic coating 2 include: polyethylene, carbon nanotubes, toluene, and a dispersant, and its preparation method is as follows: S1: Prepare low-density polyethylene LDPE in advance as the matrix material, single-walled carbon nanotubes SWCNTs as the reinforcing phase, toluene as the solvent, dispersant BYK-2155, and dispersant BYK-9076; S2: Modify the single-walled carbon nanotubes SWCNTs to introduce carboxyl functional groups, thereby improving its dispersibility in toluene and compatibility with polyethylene; or directly use single-walled carbon nanotubes SWCNTs; S3: Add the pretreated single-walled carbon nanotubes SWCNTs to toluene, and disperse it for 30 minutes by ultrasonic wave at 40 kHz; S4: Take another container and add polyethylene to toluene, heat it to 100°C ± 5°C to completely dissolve the low-density polyethylene LDPE in the solvent to form a polyethylene solution; during the heating and dissolving process, mechanically stir the solution to promote the dissolution of polyethylene and the uniformity of the solution; S5: Slowly add the dispersed carbon nanotube solution to the polyethylene solution, stir while adding, and at the same time, add dispersant BYK-2155 and dispersant BYK-9076 respectively; make the mixed solution fully mixed and uniform; then, treat the mixed solution with ultrasonic wave at 60 kHz for 30 minutes; S6: Centrifuge the ultrasonically treated mixed solution in a centrifuge at a speed of 8000 / min for 5 minutes, take the supernatant to obtain a polyethylene-carbon nanotube dispersion; S7: Take a PET film with a thickness of 75 μm and corona-treat both sides thereof, and coat the polyethylene-carbon nanotube dispersion on both sides of the PET film with a coater, and after coating, place it in an oven at 80°C and dry it for 90 seconds; thus, two said antistatic coatings 2 can be laminated on both sides of the PET substrate layer 1.

[0025] Further, in the preparation method of the foregoing antistatic coating 2, by mass, the feeding amount of low-density polyethylene LDPE is 6-8 parts, the feeding amount of single-walled carbon nanotubes SWCNTs is 3-4 parts, toluene is 300-400 parts, dispersant BYK-2155 is 3-4 parts, and dispersant BYK-9076 is 0.4-0.6 part.

[0026] Further, in the preparation method of the antistatic coating 2 described above, in terms of parts by mass, a preferred embodiment is as follows: the feeding amount of low-density polyethylene LDPE is 8 parts, the feeding amount of single-walled carbon nanotubes SWCNTs is 4 parts, toluene is 400 parts, dispersant BYK-2155 is 4 parts, and dispersant BYK-9076 is 0.6 part.

[0027] Further, in step S2 described above, the method for modifying single-walled carbon nanotubes SWCNTs to introduce carboxyl functional groups can use strong oxidants such as concentrated nitric acid, sulfuric acid, or potassium permanganate to oxidize the carbon nanotubes, thereby introducing functional groups such as hydroxyl and carboxyl groups on the surface of the carbon nanotubes; specifically: dissolve concentrated nitric acid in deionized water at room temperature to form an oxidation solvent, then disperse the carbon nanotubes in the aforementioned solvent, slowly stir for 30 minutes, then filter it repeatedly and wash it with deionized water, and finally dry the carbon nanotubes to obtain the modified carbon nanotubes.

[0028] Further, the aforementioned PET substrate layer 1 is a conventional PET film substrate, and the components of the release coating 3 include: silicone resin such as SB 7458, toluene, and platinum catalyst; the specific preparation method is as follows: S11: Weigh silicone resin SB 7458, toluene, and platinum catalyst 4000 according to the preset ratio. S12: Take a container and add toluene solvent, then put the silicone resin into the container and stir it for 15 min. S13: After the solution in the container is evenly dispersed, continue to add the platinum catalyst into the container and stir for another 5 min to obtain the release coating. S14: Use a glass rod to coat the release coating from top to bottom on one side of the aforementioned semi-finished product with the antistatic coating laminated on the PET film. S15: After coating, place it in an oven at 95 °C for drying, control the total air volume in the oven to be 25000 m 3 / h, and the drying time is 90 seconds, then the release coating 3 can be laminated on one side of the antistatic coating 2.

[0029] Specifically, in the components of the aforementioned release coating 3, in terms of parts by mass, the ratio of each material is: silicone resin 5 - 8 parts, toluene 5 - 8 parts, and platinum catalyst 0.1 - 0.15 part.

[0030] Among them, in a preferred embodiment of the release coating 3, the ratio of each material is: silicone resin 5 parts, toluene 5 parts, and platinum catalyst 0.1 part.

[0031] Further, in order to verify the durability of the antistatic effect of a PET double-layer antistatic release film of the present invention, the foregoing material ratios are all optimal examples. That is, in the antistatic coating 2: the feeding amount of low-density polyethylene LDPE is 8 parts, the feeding amount of single-walled carbon nanotubes SWCNTs is 4 parts, toluene is 400 parts, the dispersant BYK-2155 is 4 parts, and the dispersant BYK-9076 is 0.6 part; in the release coating 3: silicone resin 5 parts, toluene 5 parts, and platinum catalyst 0.1 part. They are respectively laminated on the PET substrate layer 1 according to the foregoing method; they are placed in a warehouse with an ambient temperature of 18 - 28 °C and a relative humidity of 30% - 60% for 4 months. Then, taking a commercially available ordinary PET antistatic release film as a comparative example, a four-point probe is used to measure the surface resistance of the antistatic release film; three groups of comparative data are measured respectively and their average values are taken, and the results are shown in Table 1 below.

[0032] Table 1: Comparative data on the durability of the antistatic effect

[0033] It can be seen from the comparative data in Table 1 that for a PET double-layer antistatic release film of the present invention, the change amount of the surface resistance of its coating is very small after being stored for 4 months, and there is no change in the order of magnitude, while the surface resistance of the comparative example has a significant decline. Therefore, it can be seen that a PET double-layer antistatic release film of the present invention can have better durability of the antistatic effect.

[0034] In summary, the present invention provides a PET double-layer antistatic release film, including: a PET substrate layer 1, two antistatic coatings 2, and a release coating 3; one antistatic coating 2 is laminated on each of the two side surfaces of the PET substrate layer 1, and a release coating 3 is laminated on the other side surface of one of the antistatic coatings 2; the components of the antistatic coating 2 include: polyethylene, carbon nanotubes, toluene, and a dispersant; the components of the release coating 3 include: silicone resin, toluene, and a platinum catalyst. This PET double-layer antistatic release film can still maintain good antistatic performance after being stored for 4 months; thus, a PET double-layer antistatic release film of the present invention solves the technical problem of how to improve the poor durability of the antistatic effect existing in the existing antistatic release film.

[0035] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0036] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A PET double-layer antistatic release film, characterized in that: It includes: a PET substrate layer, two antistatic coatings and a release coating; the two sides of the PET substrate layer are respectively stacked with an antistatic coating, and the other side of the antistatic coating is stacked with a release coating; the components of the antistatic coating include: polyethylene, carbon nanotubes, toluene and a dispersant.

2. A PET double-layer antistatic release film according to claim 1, characterized in that: By weight, the components of the antistatic coating include: 6-8 parts of low-density polyethylene LDPE, 3-4 parts of single-walled carbon nanotubes SWCNTs, 300-400 parts of toluene, 3-4 parts of dispersant BYK-2155 and 0.4-0.6 parts of dispersant BYK-9076.

3. A PET double-layer antistatic release film according to claim 2, characterized in that: In parts by mass, the components of the antistatic coating include: 8 parts of low-density polyethylene LDPE, 4 parts of single-walled carbon nanotubes SWCNTs, 400 parts of toluene, 4 parts of dispersant BYK-2155 and 0.6 parts of dispersant BYK-9076.

4. The PET double-layer antistatic release film according to claim 1, characterized in that: Among the components of the antistatic coating, the carbon nanotubes used are modified carbon nanotubes, which are oxidized by concentrated nitric acid, sulfuric acid or potassium permanganate to introduce carboxyl functional groups on the surface of the carbon nanotubes.

5. The PET double-layer antistatic release film according to claim 1, characterized in that: Among the components of the antistatic coating, polyethylene and carbon nanotubes are first processed into a polyethylene-carbon nanotube composite material, and then mixed with toluene and a dispersant to form the antistatic coating.

6. The PET double-layer antistatic release film according to claim 1, characterized in that: The components of the release coating are, by weight, 5-8 parts of silicone resin, 5-8 parts of toluene and 0.1-0.15 parts of platinum catalyst.

7. A PET double-layer antistatic release film according to claim 6, characterized in that: The components of the release coating are, by weight, 5 parts of silicone resin, 5 parts of toluene and 0.1 parts of platinum catalyst.

Images