Printing antistatic polyester release film and preparation method thereof

Abstract

The invention discloses a printing antistatic polyester release film and a preparation method thereof, the release film is composed of a PET base film and a release agent layer firmly combined with the PET base film, the PET base film is formed by blending, melting, extruding and stretching PET particles added with a composite additive, and the release agent layer is formed by curing a release agent; wherein the composite additive is prepared from polyvinylpyrrolidone, graphene oxide, 3-aminopropyl triethoxy silane and polyvinyl butyral. The release agent is prepared from a polydimethylsiloxane-amino siloxane copolymer, fluorosiloxane resin, a quaternary ammonium salt type antistatic agent, isocyanate silane and a mixture of butyl acetate and methylbenzene. The composite additive provided by the invention not only can provide stable antistatic performance when being added, but also can further enhance the printing performance and the surface activity of the PET base film in the subsequent plasma treatment process, so that the composite additive is suitable for applications such as electronic product packaging, labels and the like which have high requirements on static electricity and printing performance.

Description

Technical Field

[0001] The present invention relates to the technical field of release films, in particular to a release film with printing and antistatic functions, and more particularly to a printed antistatic polyester release film and a preparation method thereof. Background Art

[0002] Release films are widely used in the electronics, packaging, automotive, and pharmaceutical and medical industries. They are usually used as protective films, circuit board labels, decorative protective films, and adhesive layer protective films and transfer films in the manufacturing processes of various industries. Release films are usually composed of a base film and a release agent layer firmly bonded to the base film. In recent years, in emerging precision application fields such as electronics, it is sometimes necessary to print patterns or logos on the side of the base film away from the release agent layer for easy identification. When the finished release film is wound into a roll for packaging, the release agent layer will come into contact with the side printed with the pattern after winding. When used, the release agent layer needs to be able to be smoothly separated from the pattern side without any release agent residue, and at the same time, it is necessary to avoid adverse effects caused by static electricity during the peeling operation. Therefore, in practical applications, release films with both printing and anti-static functions need to consider the compatibility of the base film with the printing process (such as screen printing, inkjet printing, etc.) to ensure that the pattern is clear and wear-resistant. The release agent will not corrode or damage the printed layer. The release agent must have good adhesion to the base film and strong release properties after curing, ensuring no adhesive residue remains after peeling. It must also effectively prevent static electricity accumulation, prevent malfunctions or damage caused by static electricity, and avoid the adhesion of dust and particulate matter.

[0003] In the prior art, no product or application has been found that simultaneously addresses the printability and antistatic properties of release films, nor has any mention been found of the problems and solutions that require simultaneous consideration of the printing function, antistatic function, and release function.

[0004] For example, CN 110211483 B discloses a printable double-antistatic label material with adhesive surface and a preparation method thereof, wherein the label comprises, from top to bottom, a polymer GMS antistatic coating, a transparent PET film, a polythiophene coating, a lithium sulfonate antistatic adhesive, and a glassine base paper. The printable double-antistatic label with adhesive surface of the prior art requires a polymer GMS antistatic coating to be provided on one side of the PET film, and a polythiophene coating and a lithium sulfonate antistatic adhesive to be provided on the other side, and the structure and preparation process are very complicated. In particular, the firmness of the bond between the antistatic adhesive and the polythiophene coating is difficult to ensure, and the antistatic adhesive must also be protected by glassine release paper. In addition, since the prior art proposes a label, it does not involve a series of issues such as the bond between the release film packaging and the release agent and the base film during use, the impact on the printed pattern, and the release property, and therefore cannot provide technical inspiration for reference.

[0005] CN 111572148 B discloses a BOPP / PE film suitable for double-sided printing and a processing method thereof. The film utilizes a three-layer co-extrusion process comprising an outer layer, an intermediate layer, and an outer layer. The outer layer comprises a polypropylene copolymer, a polyethylene copolymer, and a printing agent, while the intermediate layer comprises a polypropylene homopolymer, a reinforcing agent, and an antistatic agent. This prior art also has a complex multilayer structure and preparation process. The antistatic agent in the intermediate layer has difficulty effectively affecting the outer structure, which is prone to static electricity. The prior art also does not address the technical issues related to release film technology or provide any reference technical inspiration.

[0006] Similarly, CN 106928483 B discloses a printed film-type printing material and preparation method. The top and bottom surfaces of a PET film are sequentially provided with an antistatic coating and a printed coating. This prior art, in which the antistatic coating and printed coating are disposed on opposite sides of the PET film and do not interact with each other, does not address technical issues related to printing and release properties, and thus cannot serve as a reference for the field. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a printed antistatic polyester release film and a preparation method thereof, so as to reduce or avoid the above-mentioned problems.

[0008] To solve the above technical problems, the present invention proposes a printed antistatic polyester release film, which is composed of a PET base film and a release agent layer firmly bonded to the PET base film. The PET base film is formed by blending PET particles added with a composite additive, melt-extruded, and then stretched, and the release agent layer is formed by curing the release agent; wherein the composite additive is composed of polyvinyl pyrrolidone, graphene oxide, 3-aminopropyltriethoxysilane, and polyvinyl butyral.

[0009] Preferably, the weight parts of the components in the composite additive are: 50-70 parts by weight of polyvinyl pyrrolidone, 10-20 parts by weight of graphene oxide, 5-10 parts by weight of 3-aminopropyltriethoxysilane, and 10-15 parts by weight of polyvinyl butyral.

[0010] Preferably, the addition amount of the composite additive is 5-10% of the total mass.

[0011] Preferably, the release agent is composed of a mixture of polydimethylsiloxane-aminosiloxane copolymer, fluorosilicone resin, quaternary ammonium salt antistatic agent, isocyanate silane, butyl acetate and toluene.

[0012] Preferably, the contents of the components in the release agent are: polydimethylsiloxane-aminosiloxane copolymer: 50-60wt%, fluorosilicone resin: 15-20wt%, quaternary ammonium salt antistatic agent: 7-9wt%, isocyanate silane: 5-7wt%, butyl acetate and toluene mixed solvent: 23-25wt%.

[0013] Preferably, the thickness of the release agent layer is 1-3 μm.

[0014] The present invention also proposes a method for preparing the above-mentioned printed antistatic polyester release film, comprising the following steps: surface-modifying graphene oxide using 3-aminopropyltriethoxysilane; mixing the surface-modified graphene oxide with polyvinyl pyrrolidone and polyvinyl butyral to prepare a composite additive; blending the prepared composite additive with PET particles, melt-extruding, and then biaxially stretching to prepare a film; and plasma-treating the biaxially stretched film.

[0015] Preferably, the surface modification treatment of graphene oxide further includes the following steps: adding graphene oxide powder to anhydrous ethanol to form a graphene oxide suspension with a concentration of 1-2wt%; treating the suspension with an ultrasonic disperser for 30-60 minutes; adding 3-aminopropyltriethoxysilane to the graphene oxide suspension, stirring and reacting at 40-60°C for 1-4 hours; separating the modified graphene oxide from the solution by a centrifuge, and then washing with anhydrous ethanol multiple times to remove unreacted 3-aminopropyltriethoxysilane; and drying the washed graphene oxide at 50-70°C to obtain surface-modified graphene oxide powder.

[0016] Preferably, the preparation method further comprises the following steps: adding a polydimethylsiloxane-aminosiloxane copolymer and a fluorosilicone resin into a stirred reactor in proportion and stirring and mixing; adding a quaternary ammonium salt antistatic agent and stirring evenly; slowly adding a mixture of butyl acetate and toluene, stirring until the system is uniform, and adjusting the viscosity to 20-30 seconds; finally, adding an isocyanate silane crosslinker and stirring until it is evenly distributed; filtering the mixed release agent through a 200-mesh sieve to remove insoluble particles; performing vacuum degassing after filtration to remove residual bubbles in the solution; and evenly coating the release agent on the surface of the plasma-treated PET base film.

[0017] Preferably, the preparation method further comprises the following steps: after coating, drying by hot air at a drying temperature of 80-120° C.; and curing at a curing temperature of 150-180° C. for 2-5 minutes.

[0018] The composite additive of the present invention can not only provide stable antistatic performance when added internally, but also further enhance the printing performance and surface activity of the PET base film during the subsequent plasma treatment process. The PET base film prepared by the preparation method of the present invention can give full play to the advantages of the composite additive, not only effectively improve the antistatic performance, but also generate a large number of active groups through plasma treatment, significantly improve the printing performance, and has high innovation and application potential. It is particularly suitable for use in fields such as high-end electronic product packaging, display protective films, electronic labels, flexible circuit board substrates, etc. that have high requirements for static electricity and printing performance. By adding this composite additive internally, the PET release film can achieve antistatic, dustproof, and anti-static damage while having excellent printing performance to meet high-precision printing requirements. The present invention also specifically designs a release agent formula and preparation method suitable for this base film surface and treatment process, which has excellent release effect, antistatic performance and compatibility with the base film surface. DETAILED DESCRIPTION

[0019] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific embodiments of the present invention are now described in detail.

[0020] As described in the background, due to the unique structure and limited usage of release films, the printability and release properties of release films require consideration of a range of issues, including the bonding of the release agent with the base film, the impact on the printed pattern, release properties, and antistatic properties. Therefore, the present invention provides a printable antistatic polyester release film and a method for its preparation.

[0021] Specifically, the printed antistatic polyester release film of the present invention is composed of a PET base film and a release agent layer firmly bonded to the PET base film, wherein the PET base film is formed by blending and melt-extruding PET particles with composite additives and then stretching them, and the release agent layer is formed by curing the release agent of the present invention.

[0022] Wherein, the composite additive is composed of polyvinyl pyrrolidone (PVP), graphene oxide (GO), 3-aminopropyltriethoxysilane (APTES) and polyvinyl butyral (PVB). In the composite additive of the present invention, PVP has good electrical conductivity and good compatibility with PET materials. In addition, the conductive polymer is evenly distributed in PET, which can provide stable antistatic properties while maintaining the mechanical properties of the film. Graphene oxide has a high surface area and unique surface activity, and can be introduced to enhance the functionality of the antistatic agent. APTES can generate a large number of active group materials (such as amino, hydroxyl, carboxyl, etc.) during the subsequent plasma treatment of the PET base film, thereby enhancing the hydrophilicity and printing performance of the PET base film. PVB can improve the adhesion of ink on the PET surface and is suitable for high-quality printing.

[0023] The present invention adds a composite additive to the PET base film so that the conductive polymer PVP and graphene oxide work synergistically to ensure antistatic properties without negatively affecting the transparency and mechanical properties of the film. At the same time, in addition to synergistically conducting electricity with PVP, graphene oxide can also provide a slightly rough surface, which is conducive to the physical adsorption of ink. The surface of graphene oxide contains polar groups, and these groups can be further excited during plasma treatment of the PET base film to generate more active groups such as hydroxyl and carboxyl groups, increasing the polarity of the PET surface and improving ink adhesion. APTES can also generate active groups such as amino and carboxyl groups during plasma treatment, significantly improving the hydrophilicity of the PET film, thereby improving printing performance. The composite additive of the present invention can not only provide stable antistatic properties when added internally, but can also further enhance the printing performance and surface activity of the PET base film during subsequent plasma treatment, making it suitable for applications such as electronic product packaging and labels that have high requirements for static electricity and printing performance. In addition, the present invention significantly improves the functionality of the release film at different process stages through the composite design of the additives, and has a high industrial application prospect.

[0024] In a specific embodiment, the weight proportions of the components in the composite additive are: 50-70 parts by weight of PVP, 10-20 parts by weight of graphene oxide, 5-10 parts by weight of APTES, and 10-15 parts by weight of PVB.

[0025] The PET base film for the release film of the present invention can be prepared by the following method.

[0026] 1. Surface modification of graphene oxide

[0027] The surface of graphene oxide was modified by 3-aminopropyltriethoxysilane in order to introduce active groups such as amino groups on the surface of graphene oxide to enhance its dispersibility in polymers and compatibility with other materials.

[0028] The specific steps are as follows: 10-20 parts by weight of graphene oxide powder is added to anhydrous ethanol to form a GO suspension with a concentration of 1-2 wt%.

[0029] The suspension was treated with an ultrasonic disperser (ultrasonic treatment time was 30-60 min) to ensure that the graphene oxide was fully dispersed and to avoid agglomeration.

[0030] 5-10 parts by weight of APTES are added to the graphene oxide suspension.

[0031] The reaction is stirred at 40-60°C for 1-4 hours, allowing APTES to react with polar groups such as carboxyl and hydroxyl groups on the graphene oxide surface to form silane bonds. The terminal amino groups of APTES will be modified on the graphene oxide surface, providing more reactive groups.

[0032] After the reaction is completed, the modified graphene oxide is separated from the solution by a centrifuge, and then anhydrous ethanol is added to the centrifuge and washed with anhydrous ethanol several times to remove unreacted APTES.

[0033] The cleaned graphene oxide is dried at 50-70° C. to obtain surface-modified graphene oxide powder.

[0034] 2. Preparation of composite additives

[0035] The surface-modified graphene oxide is mixed with PVP and PVB to prepare a composite additive.

[0036] The specific steps are: adding 50-70 parts by weight of PVP to ethanol, stirring and dissolving, to form a PVP solution with a concentration of 10-15wt%.

[0037] 10-15 parts by weight of PVB are dissolved in toluene to form a PVB solution with a concentration of 10-15 wt%.

[0038] According to the formula ratio (PVP: 50-70%, PVB: 10-15%), the two solutions are mixed and stirred evenly to form a PVP-PVB composite solution.

[0039] The surface-modified graphene oxide powder was added into the PVP-PVB composite solution.

[0040] A stirring reaction vessel may be used for stirring for 30-60 minutes to ensure that the graphene oxide is evenly dispersed in the solution and to avoid agglomeration.

[0041] The solvent in the dispersed mixed solution is evaporated and dried to obtain a solid composite additive powder. For example, the solid composite additive powder can be dried in a vacuum drying oven at 50-70°C to ensure that the solvent is completely evaporated to obtain the final composite additive.

[0042] 3. Mixing of composite additives into PET matrix

[0043] The prepared composite additive is blended with PET particles through a twin-screw extruder to obtain a functional PET material that is antistatic and easy to print. The amount of the composite additive added is 5-10% of the total weight. For example, the composite additive (containing PVP, PVB, and surface-modified graphene oxide) is uniformly mixed with the PET particles according to the formula ratio (5-10%).

[0044] The specific steps are:

[0045] Use a twin-screw extruder to perform melt extrusion at a temperature of 270-280°C to ensure that the composite additives are evenly dispersed in the PET matrix.

[0046] The extruded sheet is then processed into a film through casting and biaxial stretching. Biaxial stretching enhances the film's mechanical properties and surface smoothness. It also optimizes the film's surface structure, helping to improve ink adhesion. The stretching process also promotes the migration of antistatic agents to the film surface, thereby enhancing the antistatic effect.

[0047] 4. Plasma surface treatment

[0048] The biaxially oriented film is further plasma treated to increase the density of active groups on the surface and enhance the adhesion of the ink. Plasma treatment can stimulate the surface polar groups of the composite additives, generating a large number of active groups, further enhancing printability.

[0049] Process summary:

[0050] Surface modification of graphene oxide: APTES reacts with the carboxyl and hydroxyl groups on the surface of graphene oxide to introduce active groups such as amino groups, thereby improving its dispersibility in PVP and PVB.

[0051] Solution mixing and drying: The modified graphene oxide is mixed with PVP and PVB solutions, and uniform distribution is ensured by high-speed stirring and ultrasonic dispersion, and then dried to obtain a composite additive.

[0052] Blending of composite additives: The composite additives are blended and melted with PET to prepare a functional PET film with antistatic and easy-printing properties.

[0053] Through this process, the uniform dispersion of the composite additives in PET can be ensured, and the surface modification of graphene oxide greatly reduces its agglomeration phenomenon, while giving the material excellent antistatic, printing properties and surface activity.

[0054] Biaxial stretching and cooling: The resulting thick film is subjected to a biaxial stretching process to further improve its mechanical properties and surface smoothness, optimize the film's surface structure, and enhance ink adhesion. The stretching process also promotes the migration of antistatic agents to the film surface, thereby enhancing the antistatic effect.

[0055] Plasma surface treatment: The prepared PET base film is subjected to plasma treatment to stimulate the surface polar groups of the composite additives, generate a large number of active groups, and further enhance the printability.

[0056] The PET base film prepared by the preparation method of the present invention fully utilizes the advantages of the composite additive, not only effectively improving antistatic properties but also generating a large number of active groups through plasma treatment, significantly improving printing performance, showing high innovation and application potential. It is particularly suitable for use in fields with high requirements for static and printing performance, such as high-end electronic product packaging, display protective films, electronic labels, and flexible circuit board substrates. By adding this composite additive, the PET release film can achieve antistatic, dustproof, and anti-static damage while also possessing excellent printing performance, meeting the needs of high-precision printing.

[0057] The following table lists the weight parameters for preparing a PET base film, and measuring the performance parameters of the PET base film.

[0058] The names of some raw materials in the examples and subsequent comparative examples are represented by the following abbreviations or codes.

[0059] Graphene oxide: GO 3-aminopropyltriethoxysilane: APTES

[0060] Polyvinyl pyrrolidone: PVP Polyvinyl butyral: PVB

[0061]

[0062] Surface resistance was measured using ASTM D257. Surface tension was measured using ASTM D5946. Ink adhesion was measured using ISO 2409. Furthermore, when comparing adhesion after scrubbing using ASTM D2486, Examples 1-3 all demonstrated superior long-term stability in ink adhesion compared to Comparative Examples 1-4.

[0063] The surface resistances of Examples 1-3 are 2.0×108Ω / square, 1.0×109Ω / square, and 3.5×108Ω / square, respectively, showing excellent antistatic properties, which are significantly better than the resistance values ​​of Comparative Examples 1-4 (for example, Comparative Example 1 is 4.3×1012Ω / square).

[0064] In addition, after testing, the inks of Examples 1-3 can be completely dried within 3-5 seconds after printing without diffusion, and after a tape peeling test, the printed inks do not fall off.

[0065] In contrast, the inks of Comparative Examples 1-4 could not be completely dried within 3-5 seconds after printing. After the inks were completely dried, the printed inks all fell off after a tape peeling test.

[0066] In addition, when the plasma surface treatment step was omitted when preparing the base films of Examples 1-3, the surface resistance, surface tension and ink adhesion levels all decreased by about 20%-30%, indicating that the plasma surface treatment step is difficult to replace in the base film preparation process of the present invention.

[0067] Furthermore, to ensure that the PET base film with the composite additives is better compatible with the release agent applied after plasma treatment, the present invention also specifically designs a release agent formulation and preparation method suitable for this base film surface and treatment process. The following is a detailed release agent design scheme and process flow.

[0068] In a specific embodiment, the release agent of the present invention is composed of a mixture of polydimethylsiloxane-aminosiloxane copolymer, fluorosilicone resin, quaternary ammonium salt antistatic agent, isocyanate silane, butyl acetate and toluene.

[0069] In release agent of the present invention, described polydimethylsiloxane-aminosiloxane copolymer can be selected the DC-1107 of Dow Corning (Dow Corning) company, DC-1107 is amino-modified polydimethylsiloxane, possesses excellent release properties, simultaneously owing to containing amino functional group, can form better sticking force with the polar group on the PET surface after plasma treatment, improve the stability of release coating.Described fluorosilicone resin can be selected the SIFEL 611 of Shin-Etsu Chemical (Shin-EtsuChemical), SIFEL 611 is fluorosilicone resin, possesses ultra-low surface energy and good chemical resistance and anti-pollution property, can significantly promote the durability and the antistatic property of release agent, keep excellent release effect simultaneously.Described quaternary ammonium salt type antistatic agent can be selected the Varistat 3700 of Sabo company (SABO SpA), Varistat 3700 quaternary ammonium salt type antistatic agent, can effectively reduce the surface resistance of coating, prevents static accumulation and dust absorption, is particularly useful for smooth release film surface. The isocyanate silane can be selected from Evonik's Dynasylan 1189, an isocyanate-functionalized silane that crosslinks with reactive groups on the substrate surface and in the release agent, enhancing adhesion between the coating and the substrate, particularly to plasma-treated PET surfaces. The butyl acetate and toluene mixture, with a mass ratio of butyl acetate to toluene of 3:1, exhibits excellent volatility, promoting uniform coating of the release agent on the PET surface and providing suitable coating viscosity and fluidity. Butyl acetate evaporates quickly and leaves no residue, while toluene facilitates uniform dispersion of the release agent.

[0070] In a specific embodiment, the weight proportions of the components in the release agent of the present invention are: polydimethylsiloxane-aminosiloxane copolymer (DC-1107): 50-60 wt %, fluorosilicone resin (SIFEL 611): 15-20 wt %, quaternary ammonium salt antistatic agent (Varistat 3700): 7-9 wt %, isocyanate silane (Dynasylan 1189): 5-7 wt %, butyl acetate and toluene (3:1) mixed solvent: 23-25 ​​wt %.

[0071] Preparation method

[0072] 1. Mixing and dissolving

[0073] Polydimethylsiloxane-aminosiloxane copolymer (DC-1107) and fluorosilicone resin (SIFEL 611) were added into a stirred reactor according to the proportion and stirred and mixed.

[0074] Add quaternary ammonium salt antistatic agent (Varistat 3700) and stir evenly.

[0075] Slowly add the solvent (a mixture of butyl acetate and toluene) and stir until the system is uniform. Adjust the viscosity to 20-30 seconds (apply to a 4# cup).

[0076] Finally, add isocyanate silane crosslinker ( 1189), stirring until evenly distributed.

[0077] 2. Filtration and degassing

[0078] Filter the mixed release agent through a 200-mesh sieve to remove any insoluble particles.

[0079] After filtration, vacuum degassing was performed to remove the bubbles remaining in the solution.

[0080] 3. Coating

[0081] Use the blade coating method to evenly coat the release agent on the surface of the plasma-treated PET base film, and the coating thickness is controlled at 1-3 μm.

[0082] 4. Drying and curing

[0083] After coating, it is dried by hot air drying equipment at a drying temperature of 80-120°C to ensure that the solvent is completely evaporated.

[0084] Perform curing treatment at a temperature of 150-180°C for 2-5 minutes to ensure that the cross-linking reaction in the release agent occurs fully and a stable coating is formed.

[0085] The release agent of the present invention utilizes a polydimethylsiloxane-aminosiloxane copolymer, a fluorosilicone resin, and a quaternary ammonium salt antistatic agent to produce a high-performance release agent specifically designed for composite additive-containing base films and plasma-treated surfaces. The release agent exhibits excellent release properties, antistatic performance, and compatibility with base film surfaces. This release agent is not only suitable for PET release films but is also particularly well-suited for plasma-treated substrates, enhancing surface adhesion and overall stability.

[0086] The following table lists the weight percentages of the following release films to prepare release films, and measure the performance parameters of the release films.

[0087] The names of some raw materials in the examples and subsequent comparative examples are represented by the following abbreviations or codes.

[0088] Polydimethylsiloxane-Aminosiloxane Copolymer: A Fluorosilicone Resin: B

[0089] Quaternary ammonium salt antistatic agent: C Isocyanate silane: D

[0090] Butyl acetate and toluene (3:1) mixed solvent: E

[0091] Release force was measured using ASTM D3330 (180-degree peel strength), and surface energy was measured using ASTM D2578. The release forces in Examples 4-6 were 0.06 N / 10 mm, 0.04 N / 10 mm, and 0.05 N / 10 mm, respectively, demonstrating excellent release performance. In contrast, the release forces in the comparative examples were as high as 0.3-0.5 N / 10 mm, indicating poor release performance.

[0092] Further testing showed that the inks of Examples 4-6 were printed on top of the release agent layer, and none of the printed inks were separated from the release agent layer. In contrast, the inks of Comparative Examples 5-7 were separated from the release agent layer.

[0093] In summary, through the analysis of the test data of the embodiments of the present invention and the comparative examples, the following conclusions can be obtained:

[0094] 1. Polyvinylpyrrolidone (PVP) has good electrical conductivity and compatibility with PET materials. Its main function is to provide stable antistatic properties and be evenly distributed in the PET material, thereby improving the overall performance of the material. The conductivity of PVP can effectively prevent the accumulation of static electricity. In Comparative Example 3, the absence of PVP resulted in a significant decrease in antistatic performance, with the surface resistance reaching 6.7×1011Ω / square, while the surface resistance in Example 2 was only 1.0×109Ω / square. This significant difference indicates that the absence of PVP makes it difficult to release static electricity, resulting in static electricity accumulation, which is very unfavorable for electrostatically sensitive fields such as electronic products.

[0095] While PVP's primary function is antistatic, it also indirectly affects ink adhesion. The uniform distribution of PVP within the PET film provides a better foundation for surface treatment, while its polarity also helps improve ink adhesion. The absence of PVP can lead to reduced ink adhesion on the surface. For example, the ink in Comparative Example 3 only has an adhesion of 3B, while the inks in the Examples all have an adhesion of 5B.

[0096] 2. The role of graphene oxide (GO) in the present invention is to provide antistatic properties and increase surface roughness through its high surface area and surface activity, thereby improving the physical adsorption of the ink. GO can synergize with PVP to provide a more efficient antistatic effect. The polar groups of GO (such as carboxyl, hydroxyl, etc.) can not only enhance the antistatic properties, but also stimulate more active groups after plasma treatment, thereby improving surface conductivity. In Comparative Example 1, GO is completely absent, resulting in a surface resistance increase of 4.3×1012Ω / square, which is much higher than the 2.0×108Ω / square in Example 1, indicating that the absence of GO significantly weakens the antistatic ability. In addition to providing antistatic function, GO's slightly rough surface structure also helps to improve the physical adsorption of the ink. The polar groups contained in GO help to interact with the polar components in the ink, improving the adhesion of the ink. In Comparative Example 1 lacking GO, the ink adhesion is only 2B. In contrast, the ink adhesion in Example 1 with a higher GO content is 5B, indicating the significant role of GO in improving ink adhesion.

[0097] The main function of 3.3-aminopropyltriethoxysilane (APTES) is to introduce active groups, such as amino groups and carboxyl groups, during the plasma treatment of the PET base film, further enhancing the hydrophilicity and ink adhesion of the PET base film. Although the main function of APTES is not antistatic, it can introduce polar groups through plasma treatment to enhance surface conductivity. In Comparative Example 2, which lacks APTES, the surface resistance is 1.5×1012Ω / square, which is much higher than the 1.0×109Ω / square in Example 2, indicating that APTES plays an important role in improving the surface polarity and antistatic properties of the PET film. The large number of polar groups (such as amino groups and hydroxyl groups) generated by APTES after plasma treatment can significantly improve the adhesion of the ink. The lack of APTES will lead to a decrease in surface activity, resulting in insufficient adhesion of the ink. In Comparative Example 2, APTES is missing and the ink adhesion drops to 2B, which is significantly lower than the 5B in Example 2. This shows that APTES plays an important role in promoting the binding force between the ink and the PET surface.

[0098] 4. Polyvinyl butyral (PVB) is part of the composite additive, mainly to improve the adhesion of ink on the PET surface and increase the printability of the material. The polarity of PVB helps to form a strong bond between the ink and the base film surface. PVB does not directly affect the antistatic properties, but it works synergistically with other components (such as PVP and GO) to ensure the balance between the antistatic properties and ink adhesion of the material. PVB plays a key role in improving ink adhesion. In Comparative Example 4, the lack of PVB results in an ink adhesion of only 3B, while in Example 3 it is 5B. The polar groups of PVB can interact with the components in the ink, allowing the ink to adhere more firmly to the surface of the PET base film. The lack of PVB will significantly reduce the adhesion of the ink, resulting in easy shedding of the ink during the printing process.

[0099] 5. Quaternary ammonium salt antistatic agents are important components of release agents. They can reduce the surface resistance of the material, prevent static electricity accumulation, and reduce dust adsorption. In Comparative Example 5, the quaternary ammonium salt antistatic agent is missing, and the surface resistance is as high as 5.6×1011Ω / square, while the surface resistance in Example 4 is 3.3×108Ω / square. This shows that the absence of the antistatic agent in the release agent significantly reduces the antistatic properties of the material, leading to static electricity accumulation. Although the antistatic agent does not directly affect the adhesion of the ink, its absence leads to an increase in surface resistance. Static electricity accumulation may cause adverse effects on the ink during the printing process, such as ink diffusion or uneven printing.

[0100] In short, each component of the composite additive and release agent plays a significant role in antistatic performance and ink adhesion. The absence of any key component can lead to the following performance degradations: Lack of PVP, GO, or antistatic agents directly increases surface resistance, making the material susceptible to static electricity accumulation. This can cause electrostatic damage, particularly in sensitive applications such as electronics packaging. Lack of GO, PVB, or APTES significantly reduces ink adhesion, causing printed patterns to easily fall off or become unclear, making it impossible to meet the requirements of high-precision printing.

[0101] Therefore, the optimized design of the composite additive and release agent components is the key to ensuring that the present invention has excellent antistatic properties and ink adhesion.

[0102] Those skilled in the art should understand that although the present invention is described in terms of multiple embodiments, not each embodiment contains only one independent technical solution. This description is provided for clarity only. Those skilled in the art should understand the description as a whole and consider the technical solutions involved in each embodiment as being combinable into different embodiments to understand the scope of protection of the present invention.

[0103] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes, modifications and combinations made by those skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A printed antistatic polyester release film, comprising a PET base film and a release agent layer firmly bonded to the PET base film, characterized in that: The PET base film is formed by blending PET particles added with a composite additive, melt-extruding, and then stretching, and the release agent layer is formed by curing the release agent; wherein the composite additive is composed of polyvinyl pyrrolidone, graphene oxide, 3-aminopropyltriethoxysilane, and polyvinyl butyral.

2. The release film according to claim 1, wherein The weight proportions of the components in the composite additive are: 50-70 parts by weight of polyvinyl pyrrolidone, 10-20 parts by weight of graphene oxide, 5-10 parts by weight of 3-aminopropyltriethoxysilane, and 10-15 parts by weight of polyvinyl butyral.

3. The release film according to claim 1 or 2, wherein: The addition amount of the composite additive is 5-10% of the total mass.

4. The release film according to claim 1, wherein The release agent consists of a mixture of polydimethylsiloxane-aminosiloxane copolymer, fluorosilicone resin, quaternary ammonium salt antistatic agent, isocyanate silane, butyl acetate and toluene.

5. The release film according to claim 4, wherein The contents of the components in the release agent are: polydimethylsiloxane-aminosiloxane copolymer: 50-60wt%, fluorosilicone resin: 15-20wt%, quaternary ammonium salt antistatic agent: 7-9wt%, isocyanate silane: 5-7wt%, butyl acetate and toluene mixed solvent: 23-25wt%.

6. The release film according to claim 4 or 5, wherein: The thickness of the release agent layer is 1-3 μm.

7. The method for preparing a printable antistatic polyester release film according to any one of claims 1 to 6, comprising the following steps: surface-modifying graphene oxide with 3-aminopropyltriethoxysilane; mixing the surface-modified graphene oxide with polyvinyl pyrrolidone and polyvinyl butyral to prepare a composite additive; blending the prepared composite additive with PET particles, melt-extruding, and biaxially stretching to prepare a film; and plasma-treating the biaxially stretched film.

8. The preparation method according to claim 7, wherein The surface modification treatment of graphene oxide further includes the following steps: adding graphene oxide powder to anhydrous ethanol to form a graphene oxide suspension with a concentration of 1-2wt%; treating the suspension with an ultrasonic disperser for 30-60 minutes; adding 3-aminopropyltriethoxysilane to the graphene oxide suspension, stirring and reacting at 40-60°C for 1-4 hours; separating the modified graphene oxide from the solution by a centrifuge, and then washing with anhydrous ethanol multiple times to remove unreacted 3-aminopropyltriethoxysilane; and drying the washed graphene oxide at 50-70°C to obtain surface-modified graphene oxide powder.

9. The preparation method as claimed in claim 8, further comprising the steps of: adding a polydimethylsiloxane-aminosiloxane copolymer and a fluorosilicone resin to a stirred reactor in proportion and stirring and mixing; adding a quaternary ammonium salt antistatic agent and stirring evenly; slowly adding a mixture of butyl acetate and toluene, and stirring until the system is uniform, adjusting the viscosity to 20-30 seconds; finally adding an isocyanate silane crosslinking agent, and stirring until it is evenly distributed; filtering the mixed release agent through a 200 mesh sieve to remove insoluble particles; performing vacuum degassing after filtration to remove residual bubbles in the solution; and uniformly coating the release agent on the surface of the plasma-treated PET base film.

10. The preparation method according to claim 9, further comprising the following steps: after coating, drying by hot air at a drying temperature of 80-120°C; and curing at a curing temperature of 150-180°C for 2-5 minutes.

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