Platinum-cured release agent, release film and preparation method thereof

Abstract

The present invention discloses a platinum-cured release agent, a release film, and a preparation method thereof, belonging to the technical field of release materials. The platinum-cured release agent comprises the following raw materials in parts by weight: 85 parts of siloxane, of which hexenyl polydimethylsiloxane accounts for at least 80 wt%, with the remainder being hydrogen-containing siloxane; 0.8–8 parts of a sulfonic acid acrylic monomer; 0.05–2 parts of a precatalyst; 0.1–2 parts of a catalyst carrier; and 0.1–3 parts of an initiator. The catalyst carrier is a multi-walled carbon nanotube; the multi-walled carbon nanotubes are any of hydroxylated, carboxylated, amino, and graphitized multi-walled carbon nanotubes, and the precatalyst is a platinum compound. The release film prepared by the present invention exhibits good chemical stability and uniformity, low peel force, and excellent antistatic and conductive properties.

Description

Technical Field

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

[0002] Release agents are a type of chemical coating material with special functions. They have important applications in self-cleaning, decorative protection of electronic devices, adhesives, medical care, optics, electronic devices, flexible circuits, and other fields. Silicone release agents are cross-linked polymers with a silicon-oxygen chain as the backbone. Their surface groups are easily exposed, and they have low polarity, low surface energy, and excellent weather resistance and aging resistance. At the same time, silicone polymers have good solubility in commonly used aromatic and aliphatic solvents, low viscous flow activation energy, and good coating properties. They can be applied to substrates as extremely thin release coatings. The release effect of silicone coatings can also be adjusted within a certain range by changing the cross-linking density of the silicone polymer and the molecular weight and composition of the copolymer. Therefore, silicone release agents can adapt to different product requirements and are currently widely used release agents.

[0003] The hydrosilylation reaction is one of the most important reactions in the preparation of silicone release coatings. This reaction primarily occurs through the addition of unsaturated carbon-carbon bonds (C=C, C≡C) or carbon-nitrogen bonds (C=N, C≡N) to Si–H bonds. Hydrosilylation reactions typically proceed under ultraviolet light, high temperatures, and in the presence of peroxides or catalysts. Platinum-based catalysts are commonly used for hydrosilylation reactions. However, existing methods for preparing platinum catalysts suffer from high reaction temperatures, high catalyst dosages, easy agglomeration, poor stability, low conversion rates, and low catalytic selectivity. Carbon black, a commonly used catalyst support, has a weak interaction with platinum, which can lead to uneven distribution of catalyst particles, thus compromising catalytic activity. High-temperature thermal curing produces byproducts, slows the cure rate, and results in uneven crosslinking. Furthermore, the use of ultraviolet light or peroxides can easily lead to self-polymerization of unsaturated hydrocarbon compounds, reducing the selectivity and yield of the hydrogenation reaction. Furthermore, UV light has limited penetration, making it less effective in curing thick coatings or systems containing fillers. Compared with the above-mentioned curing methods, visible light curing is highly efficient, energy-saving, environmentally friendly, and economical. However, during the curing process, light intensity decays across the thickness. Furthermore, continued visible light exposure can break some molecular bonds in already cured areas. Excessive radiation can lead to excessive crosslinking, causing internal cracks. Furthermore, the different curing levels of the inner and outer layers create an insulating layer that makes it difficult to dissipate the heat and gas products released during the reaction. All of these factors can lead to peeling of the release layer, deteriorating release performance, and reducing stability.

[0004] Release films, as important functional materials, are widely used in electronics, optical devices, food processing, the chemical and pharmaceutical industries, and other fields. Currently, stricter requirements are being placed on release films in terms of strength, peel strength, high-temperature resistance, conductivity, and acid and alkali resistance. However, existing release films tend to lose their antistatic properties in high-humidity environments, limiting their application in high-precision and high-cleanliness environments. Existing technologies improve antistatic properties by adding conductive polymers to the coating. However, existing antistatic materials, such as polyaniline, have poor stability at high temperatures, resulting in insufficient adhesion between the antistatic coating and the substrate, which can easily cause the coating to fall off after prolonged use or in high-humidity environments. Summary of the Invention

[0005] In order to solve the problems of easy agglomeration, poor stability, high loading amount for catalysts such as Pt, complex loading method caused by the use of traditional catalyst carriers in the existing silane addition method, and low chemical stability of the existing release film due to the high curing temperature, the present invention provides a platinum-cured release agent, a release film and a preparation method thereof.

[0006] The technical solution adopted in the present invention is:

[0007] A platinum-curing release agent comprising the following raw materials in parts by weight:

[0008] Siloxane, 85 parts; of which hexenyl polydimethylsiloxane accounts for more than 80 wt%, and the rest is hydrogen-containing siloxane;

[0009] Sulfonic acid acrylic monomer, (0.8 – 8) parts;

[0010] Precatalyst, (0.05 – 2) parts;

[0011] Catalyst support, (0.1 – 2) parts;

[0012] Initiator, (0.1 – 3) parts;

[0013] The catalyst carrier is a multi-walled carbon nanotube, and the pre-catalyst is a platinum compound;

[0014] The multi-walled carbon nanotubes are any one of hydroxylated multi-walled carbon nanotubes, carboxylated multi-walled carbon nanotubes, amino multi-walled carbon nanotubes and graphitized multi-walled carbon nanotubes.

[0015] The structural formula of hexenyl polydimethylsiloxane is:

[0016]

[0017] The structural formula of hydrogen siloxane is:

[0018]

[0019] Furthermore, the number average molecular weight of the siloxane is 200,000-800,000.

[0020] Furthermore, the sulfonic acid acrylic monomer is at least one of 2-acrylamido-2-methyl-1-propanesulfonic acid, ethyl methacrylate sulfonate and sodium allyloxybenzenesulfonate.

[0021] Furthermore, the platinum compound is any one of K2PtCl4, H2PtCl6·6H2O, K2PtCl6, Pt (NH3)2Cl2 and K2[Pt(CN)4]·3H2O.

[0022] Furthermore, the initiator is any one of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, benzophenone and 2-hydroxy-2-methyl-1-phenyl-1-propanone.

[0023] Furthermore, the molecular structure of the catalyst carrier is as follows:

[0024] .

[0025] A release film comprises a substrate and any one of the above-mentioned platinum-curing release agents coated on one side of the substrate.

[0026] Furthermore, the material of the substrate is PET, and the thickness of the release agent layer is 20-48 μ m.

[0027] The method for preparing any of the above release films comprises the following steps:

[0028] (1) Siloxane, precatalyst, and catalyst carrier are mixed according to the ratio and stirred under visible light for a certain time, and then sulfonic acid acrylic monomer and initiator are added and mixed again to obtain a release agent;

[0029] (2) The release agent prepared in step (1) is evenly coated on the substrate with a certain thickness, and cured at a certain temperature to obtain a release film.

[0030] The reaction principle of curing is as follows:

[0031] .

[0032] The advantages of the structure of sulfonic acid acrylic monomers are: (1) Due to the introduction of rigid large side groups (the main side groups are –CONHC(CH3)2CH2SO3 – ) connection, so that the thermal stability of the release film is improved; (2) the –SO3 –From the charge theory, the two π bonds between S and O and the three strongly electronegative O atoms share a negative charge, which makes the charge density around the group accumulate, thereby making its hydration stronger and not sensitive to cations in the external environment. Therefore, the release film has excellent salt resistance. (3) The sulfonic acid group is a strong anionic group with strong hydrophilicity and electrostatic repulsion and can effectively hinder the curling of the molecular chain and improve the viscosity of the release agent. (4) The sulfonic acid group can effectively inhibit the hydrolysis of the polymer at high temperature, protect the amide group, and thus improve the temperature resistance of the release film. (5) The amount of siloxane in the release agent is reduced. By controlling the ratio of the two siloxanes to the sulfonic acid acrylic monomer, that is, adjusting the ratio of x / y / z, the performance of the release film can be controlled.

[0033] Further preferably, in step (1), the wavelength of visible light is ≥420 nm, and the stirring reaction time is 0.5-2 hours. The purpose of stirring the reaction under the irradiation of visible light with a wavelength ≥420 nm is to ensure the formation of the catalyst. The irradiation time is generally not less than 0.5 hour and not more than 2 hours. Excessive irradiation time will result in energy waste.

[0034] To ensure that the curing reaction is complete, it is further preferred that in step (2), the ambient temperature of the curing reaction is 25-45°C and the reaction time is 1.3-8 hours.

[0035] Beneficial effects of the present invention:

[0036] 1. The functional groups on the surface of surface-functionalized multi-walled carbon nanotubes strengthen their interaction with Pt, which can improve the dispersion of the catalyst and its compatibility with other materials, thereby avoiding catalyst agglomeration and reducing the catalyst loading; and multi-walled carbon nanotubes have a large specific surface area, good stability and conjugated structure, which can effectively adsorb and stabilize the catalyst, thereby improving the catalytic efficiency; multi-walled carbon nanotubes have excellent electrical conductivity and mechanical properties. The conductive properties of carbon nanotubes can prevent the generation and accumulation of static electricity on the surface of the release film, thereby improving the conductivity of the release film.

[0037] 2. The present invention utilizes a mild room-temperature curing method to in-situ form a Pt-based catalyst on multi-walled carbon nanotubes. The formed Pt catalyst has the advantages of low loading, low curing temperature, high catalytic activity, and high selectivity. At the same time, the Pt catalyst can also be combined with other active components to optimize the comprehensive performance of the release film.

[0038] 3. The present invention introduces a sulfonic acid acrylic monomer, which, on the one hand, can reduce the amount of silicone used, adjust the hydrophilicity of the release agent, adjust the viscosity of the release agent, and utilize its charge to reduce the catalyst repulsion in the reaction, thereby making the reaction more complete and reducing the generation of by-products. On the other hand, after the sulfonic acid acrylic monomer is introduced, the thermal stability of the release film is improved due to the interaction between van der Waals forces and hydrogen bonds, and it has a certain contribution to the surface smoothness of the release film, making it well adaptable to use in special environments.

[0039] 4. In-situ photodeposition is used to deposit Pt onto the carrier. Unlike chemical reduction and hydrothermal reduction techniques, this process requires no external energy (no reducing agent or heat consumption). Photoexcitation of the pre-catalyst material yields micro-nanofunctional materials, effectively reducing material contamination and production costs while ensuring the catalyst material is intact and stable. Furthermore, the curing process is unaffected by light, enabling rapid curing, low cost, and controllable process for release film preparation. This results in a stable, non-flaking release layer, improved release performance, and enhanced stability.

[0040] In general, the present invention utilizes a room temperature curing method to in situ photodeposit a Pt-based catalyst on multi-walled carbon nanotubes, and prepares a release film by low-loading room temperature curing. This method has the advantages of simple operation, strong selectivity, and a safe and environmentally friendly process. It can produce a release film with excellent performance in a more economical manner, and the produced release film has the characteristics of uniform surface, low peeling force, adjustable release force, and good conductivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a scanning electron microscope image of the functionalized multi-walled CNT used in Example 1.

[0042] Figure 2 This is a scanning electron microscope image of the CNT-Pt prepared in Example 1.

[0043] Figure 3 This is a 3D height map of the cured release film A prepared in Example 1.

[0044] Figure 4 The hydrogen nuclear magnetic resonance spectra of the curable release films prepared in Example 1 and Comparative Examples 1-5 before and after curing are shown.

[0045] Figure 5 The infrared spectra of the curable release films prepared in Example 1 and Comparative Examples 1-5 before and after curing are shown.

[0046] Figure 6 Thermal analysis diagrams of the cured release films prepared in Example 1 and Comparative Example 1.

[0047] Figure 7These are hydrogen nuclear magnetic resonance spectra of the curable release film A prepared in Example 1 before and after acid and alkali treatment.

[0048] Figure 8 These are infrared spectra of the curable release film A prepared in Example 1 before and after acid and alkali treatment. DETAILED DESCRIPTION

[0049] The technical solution of the present invention is described in detail below through specific embodiments, but the protection scope of the present invention is not limited to the embodiments.

[0050] The raw materials used in the following examples and comparative examples are all commercially available.

[0051] Hexenyl polydimethylsiloxane was purchased from Dow Corning (PC183) and was used after removing the solvent.

[0052] Hydrogenated siloxane was purchased from Dow Corning (HH127) and was used after removing the solvent.

[0053] The vector was purchased from Beijing Yinuokai Co., Ltd. (A57667).

[0054] The precatalyst was purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd.

[0055] Sulfonic acid acrylic monomers: 2-acrylamido-2-methyl-1-propanesulfonic acid (A800508), ethyl methacrylate sulfonate (E808775) and / or sodium allyloxybenzenesulfonate (S818450) were purchased from MacLean.

[0056] Initiators: Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (511447), benzophenone (8018010005), and 2-hydroxy-2-methyl-1-phenyl-1-propanone (405655) were purchased from MacLean. Example 1

[0057] The preparation method of the curable release film A is as follows:

[0058] (1) 3.0 g of hexenyl polydimethylsiloxane with a number average molecular weight of about 250,000, 0.5 g of hydrogenated siloxane, 0.028 g of K2PtCl4, and 0.05 g of graphitized multi-walled CNT were mixed evenly and stirred under visible light (wavelength ≥ 420 nm) for 1 hour. Then, 0.2 g of 2-acrylamido-2-methyl-1-propanesulfonic acid and 0.12 g of initiator phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide were added and the above components were mixed evenly to obtain release agent A;

[0059] (2) The release agent A is evenly coated on the surface of the PET substrate layer and the reaction time is 2.5 hours at a temperature of 40 ° C to obtain a cured release film A, the thickness of which is 20 ± 2 μ m.

[0060] The scanning electron microscope image of the graphitized multi-walled CNT used in this example is shown in Figure 1 .from Figure 1 It can be seen that the raw material multi-walled graphitized CNT has no obvious agglomeration, has a large specific surface area, exposes more active sites, and is more conducive to the loading of the catalyst.

[0061] In order to test the supporting effect of multi-walled CNT, 0.028 g K2PtCl4 and 0.05 g graphitized multi-walled CNT were mixed evenly and stirred under visible light (wavelength ≥ 420 nm) for 1 hour to obtain the carrier-catalyst CNT-Pt. The scanning electron microscopy image of the obtained carrier-catalyst is shown in Figure 2 .from Figure 2 It can be seen that Pt can be successfully loaded on carbon nanotubes using this method, and there is no agglomeration and uniform dispersion after the reaction.

[0062] The prepared curable release film A was subjected to EDS spectrum test analysis, and the amount of the supported catalyst Pt obtained by in-situ photodeposition was 26 wt % relative to the added carbon nanotube carrier.

[0063] The surface morphology of the prepared curing release film A was analyzed, and the results are shown in Figure 3 ;from Figure 3 It can be found that the surface thickness of the prepared cured release film A is uniform and there is no obvious protrusion.

[0064] The prepared light-curable release film A was subjected to an acid-base stability test. The test method was as follows: the film was immersed in a 0.1M hydrochloric acid solution and a 0.1M sodium hydroxide solution for 12 hours, then washed with deionized water, and then subjected to nuclear magnetic resonance and infrared tests. The test results are shown in FIG. Figure 7 and Figure 8 .from Figure 7 and Figure 8 It can be found that after being soaked in acid and alkali, the characteristic peaks of the release film have no obvious changes, indicating that the release film prepared in Example 1 has good acid and alkali stability. Example 2

[0065] The preparation method of the curable release film B is as follows:

[0066] (1) 7.6 g of hexenyl polydimethylsiloxane with a number average molecular weight of about 350,000, 1.3 g of hydrogenated siloxane, 0.046 g of K2PtCl6, and 0.02 g of carboxylated multi-walled CNT were mixed evenly and stirred under visible light (wavelength ≥ 420 nm) for 1 hour. Then, 0.21 g of sodium allyloxybenzenesulfonate and 0.268 g of initiator benzophenone were added and mixed evenly to obtain release agent B.

[0067] (2) The release agent B is evenly coated on the surface of the PET substrate layer and reacted at a temperature of 25 ° C for 8 hours to obtain a cured release film B. The thickness of the release agent layer is 20 ± 2 μ m. Example 3

[0068] The preparation method of the curable release film C is as follows:

[0069] (1) 9.8 g of hexenyl polydimethylsiloxane with a number average molecular weight of about 500,000, 2.1 g of hydrogen-containing siloxane, 0.069 g of H2PtCl6·6H2O, and 0.035 g of carboxylated multi-walled CNT were mixed evenly and stirred under visible light (wavelength ≥ 420 nm) for 1 hour. Then, 0.78 g of 2-acrylamido-2-methyl-1-propanesulfonic acid was added. μ L initiator 2-hydroxy-2-methyl-1-phenyl-1-propanone, and the above components are mixed evenly to obtain release agent C;

[0070] (2) The release agent C was evenly coated on the surface of the PET substrate layer and the reaction time was 6.5 hours at a temperature of 28 ° C to obtain a cured release film C. The thickness of the release agent layer was 36 ± 2 μ m. Example 4

[0071] The preparation method of the curable release film D is as follows:

[0072] (1) 8.6 g of hexenyl polydimethylsiloxane with a number average molecular weight of about 750,000, 3.4 g of hydrogenated siloxane, 0.033 g of Pt (NH3)2Cl2, and 0.054 g of hydroxylated multi-walled CNT were mixed evenly and stirred under visible light (wavelength ≥ 420 nm) for 1 hour. 0.13 g of ethyl methyl propylene sulfonate and 0.11 g of 2-acrylamido-2-methyl-1-propane sulfonic acid and 0.236 g of initiator benzophenone were added and the above components were mixed evenly to obtain release agent D.

[0073] (2) The release agent D was evenly coated on the surface of the PET substrate layer and the reaction time was 5.2 hours at a temperature of 32 ° C to obtain a cured release film D. The thickness of the release agent layer was 32 ± 2 μ m. Example 5

[0074] The preparation method of the curable release film E is as follows:

[0075] (1) 7.5 g of hexenyl polydimethylsiloxane with a number average molecular weight of about 800,000, 2.9 g of hydrogenated siloxane, 0.033 g of K2[Pt(CN)4]·3H2O, and 0.025 g of amino-modified multi-walled CNT were mixed evenly and stirred under visible light (wavelength ≥ 420 nm) for 1 hour. 0.47 g of ethyl methyl propylene sulfonate, 0.165 g of initiator phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, and 0.125 g of benzophenone were added and mixed evenly to obtain release agent E.

[0076] (2) The release agent E was evenly coated on the surface of the PET substrate layer and the reaction time was 3.8 hours at a temperature of 35 ° C to obtain a cured release film E. The thickness of the release agent layer was 38 ± 2 μ m. Example 6

[0077] The preparation method of the curable release film F is as follows:

[0078] (1) 6.8 g of hexenyl polydimethylsiloxane with a number average molecular weight of about 750,000, 0.26 g of hydrogenated siloxane, 0.021 g of H2PtCl6·6H2O, and 0.03 g of carboxylated multi-walled CNT were mixed evenly and stirred under visible light (wavelength ≥ 420 nm) for 1 hour. 0.35 g of ethyl methyl propylene sulfonate and 126 μ L initiator 2-hydroxy-2-methyl-1-phenyl-1-propanone, the above components are mixed evenly to obtain release agent F;

[0079] (2) The release agent F was evenly coated on the surface of the PET substrate layer and the reaction time was 3.2 hours at a temperature of 38 ° C to obtain a cured release film F. The thickness of the release agent layer was 41 ± 2 μ m. Example 7

[0080] The preparation method of the curable release film G is as follows:

[0081] (1) 5.4 g of hexenyl polydimethylsiloxane with a number average molecular weight of about 720,000, 0.13 g of hydrogenated siloxane, 0.015 g of H2PtCl6·6H2O, and 0.025 g of amino-modified multi-walled CNT were mixed evenly and stirred under visible light (wavelength ≥ 420 nm) for 1 hour. 0.16 g of 2-acrylamido-2-methyl-1-propanesulfonic acid and 0.09 g of sodium allyloxybenzenesulfonate and 0.135 g of initiator phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide were added and the above components were mixed evenly to obtain release agent G.

[0082] (2) The release agent G is evenly coated on the surface of the PET substrate layer and reacted at a temperature of 42 ° C for 2 hours to obtain a cured release film F. The thickness of the release agent layer is 35 ± 2 μ m. Example 8

[0083] The preparation method of the curable release film H is as follows:

[0084] (1) 6.5 g of hexenyl polydimethylsiloxane with a number average molecular weight of about 600,000, 0.21 g of hydrogenated siloxane, 0.021 g of K2PtCl4, and 0.15 g of graphitized multi-walled CNT were mixed uniformly and stirred under visible light (wavelength ≥ 420 nm) for 1 hour. Then, 0.32 g of sodium allyloxybenzenesulfonate and 158 μ L initiator olefin 2-hydroxy-2-methyl-1-phenyl-1-propanone, and the above components are mixed evenly to obtain the release agent H;

[0085] (2) The release agent H is evenly coated on the surface of the PET substrate layer, and the reaction time is 1.3 hours at a temperature of 45 ° C to obtain a cured release film H, the thickness of which is 36 ± 2 μ m.

[0086] Comparative Example 1

[0087] (1) 3.0 g of hexenyl polydimethylsiloxane with a number average molecular weight of about 250,000, 0.5 g of hydrogenated siloxane, 0.028 g of K2PtCl4, and 0.05 g of graphitized multi-walled CNT were mixed evenly, and stirred under visible light (wavelength ≥ 420 nm) for 1 hour. Then, 0.12 g of initiator phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide was added, and the above components were mixed evenly to obtain comparative release agent 1;

[0088] (2) The comparative release agent 1 was evenly coated on the surface of the PET substrate layer, and the reaction time was 2.5 hours at a temperature of 40°C to obtain a comparative curable release film 1.

[0089] The release films prepared in Example 1 and Comparative Example 1 were subjected to thermogravimetric analysis tests, and the results are shown in Figure 6 . Figure 6 It shows that the addition of sulfonic acid acrylic monomer can effectively increase the thermal decomposition temperature of the release film, and the residual mass after high-temperature heating is the highest, indicating that the stability of the release film of the present application is significantly improved.

[0090] Comparative Example 2

[0091] (1) 3.0 g of hexenyl polydimethylsiloxane with a number average molecular weight of approximately 250,000, 0.5 g of hydrogenated siloxane, 0.028 g of K2PtCl4, and 0.05 g of graphitized multi-walled CNT were mixed uniformly and stirred under visible light (wavelength ≥ 420 nm) for 1 hour. Then, 0.2 g of 2-acrylamido-2-methyl-1-propanesulfonic acid was added and the above components were mixed uniformly to obtain comparative release agent 2;

[0092] (2) The comparative release agent 2 was evenly coated on the surface of the PET substrate layer, and the reaction time was 2.5 hours at a temperature of 40°C to obtain a comparative curable release film 2.

[0093] Comparative Example 3

[0094] (1) 3.0 g of hexenyl polydimethylsiloxane with a number average molecular weight of about 250,000, 0.5 g of hydrogenated siloxane, and 0.05 g of graphitized multi-walled CNT were mixed evenly and stirred under visible light (wavelength ≥ 420 nm) for 1 hour. Then, 0.2 g of 2-acrylamido-2-methyl-1-propanesulfonic acid and 0.12 g of initiator phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide were added and the above components were mixed evenly to obtain comparative release agent 3;

[0095] (2) The comparative release agent 3 was evenly coated on the surface of the PET substrate layer, and the reaction time was 2.5 hours at a temperature of 40°C to obtain a comparative curable release film 3.

[0096] Comparative Example 4

[0097] (1) 3.0 g of hexenyl polydimethylsiloxane with a number average molecular weight of about 250,000, 0.5 g of hydrogenated siloxane, and 0.028 g of K2PtCl4 were mixed evenly and stirred under visible light (wavelength ≥ 420 nm) for 1 hour. Then, 0.2 g of 2-acrylamido-2-methyl-1-propanesulfonic acid and 0.12 g of initiator phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide were added and the above components were mixed evenly to obtain comparative release agent 4;

[0098] (2) The comparative release agent 4 was evenly coated on the surface of the PET substrate layer, and the reaction time was 2.5 hours at a temperature of 40°C to obtain a comparative curable release film 4.

[0099] Comparative Example 5

[0100] (1) 3.0 g of hexenyl polydimethylsiloxane with a number average molecular weight of about 250,000, 0.5 g of hydrogenated siloxane, 0.028 g of K2PtCl4, and 0.05 g of graphitized multi-walled CNT were mixed evenly and stirred at 150°C for 3 hours. Then, 0.2 g of 2-acrylamido-2-methyl-1-propanesulfonic acid and 0.12 g of initiator phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide were added and the above components were mixed evenly to obtain comparative release agent 5.

[0101] (2) The comparative release agent 5 was evenly coated on the surface of the PET substrate layer and reacted at a temperature of 40°C for 2.5 hours to obtain a comparative cured release film 5, the thickness of which was 20 ± 2 μ m.

[0102] The curable release films prepared in Example 1 and Comparative Examples 1-5 were characterized, and the H NMR spectra showed Figure 4 , the results of infrared test are shown in Figure 5 .

[0103] from Figure 4 It can be found that since no monomer is added in Comparative Example 1, almost no curing reaction occurs. After curing, for Example 1, the signal at δ4.50 ppm is significantly weakened, corresponding to the methylene proton signal at the chain end, and the signal at δ1.55 ppm is significantly weakened, corresponding to the breakage of -CH=CH-, indicating that the curing reaction is proceeding. The signal at δ2.23 ppm is significantly enhanced compared to Comparative Examples 3 and 4, indicating that the addition of pre-catalyst and catalyst support can effectively promote the forward progress of the curing reaction.

[0104] from Figure 5 It can be found that after the release film of Example 1 is subjected to addition reaction with platinum catalyst, the 2167 cm-1 peculiar to the –Si-H bond in the raw siloxane is -1 The infrared absorption band at 1631 cm-1 is significantly weakened, and the 1631 cm-1 absorption band unique to olefins in the hexenyl group is significantly weakened. -1 The infrared absorption band at 400 nm disappears, indicating that the curing reaction occurs.

[0105] The resistivity of the cured release films obtained in Examples 1-8 and Comparative Examples 1-5 was tested using a thin film square resistance four-probe method. The results are shown in Table 1.

[0106]

[0107] From the resistivity data in Table 1, it can be seen that compared with Comparative Example 4 without the addition of a carbon nanotube carrier, the resistivity of Examples 1-8, Comparative Examples 1-3 and Comparative Example 5 is significantly reduced, indicating that the addition of the carbon nanotube carrier can make the release film have good conductivity.

[0108] The cured release films obtained in Examples 1-8 and Comparative Examples 1-5 were tested for peel force, roughness, contact angle, and thickness. The results are shown in Table 2. The peel force test was conducted according to GB / T 25256-2010, and the thickness test was conducted according to ASTM D882-18-2018.

[0109] The curing conditions of the release films prepared in Examples 1-8 and Comparative Examples 1-5 are shown in Table 3.

[0110]

[0111]

[0112] From the results of the extreme differences in roughness and thickness in Table 2, it can be seen that the surface of the release film provided by the present invention is smooth, and the roughness and thickness are evenly distributed.

[0113] Comparing the results of Examples 1-8, combined with the results of Comparative Example 1, shows that the presence of a sulfonic acid acrylic monomer significantly affects the release strength, but the type of sulfonic acid acrylic monomer has little effect on the release strength performance. Furthermore, using different ratios of silicone also affects the release strength of the release film.

[0114] Comparison of the water contact angles of the release films obtained in Examples 1-8 and Comparative Example 1 shows that the sulfonic acid acrylic monomer introduced in the present invention can improve the hydrophilicity of the release film.

[0115] Comparison of the results of Examples 1-8 and Comparative Example 2 shows that the absence of an initiator has a significant impact on the peeling force, roughness, and conductivity.

[0116] Comparison of the results of Examples 1-8 and Comparative Example 3 shows that the absence of the pre-catalyst has a significant impact on the peeling force and roughness.

[0117] Comparison of the results of Examples 1-8 and Comparative Example 4 shows that the absence of a carrier has a significant impact on the peeling force, roughness, and conductivity.

[0118] Comparison of the results of Examples 1-8 and Comparative Example 5 shows that the traditional method of loading the platinum catalyst has a significant impact on the peeling force, roughness, and conductivity.

[0119] As can be seen from Table 3, the comparison results of Comparative Examples 1-8 and Comparative Examples 1-5 show that during the curing process, as the temperature changes in the range of 25-45°C, the curing time fluctuates in the range of 1.3-8 h, and the overall curing time shortens with increasing curing temperature.

[0120] The above analysis demonstrates that the ratio of siloxane to sulfonic acid acrylic monomer and carrier, among other factors, influences the performance of the release film, resulting in a comprehensive and systematic impact. Overall, the release film provided by the present invention exhibits controllable and low peel force, good antistatic and electrical conductivity, and excellent chemical stability, meeting the requirements of applications in electronics, optical devices, food processing, the chemical, and pharmaceutical industries.

[0121] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A platinum-curing release agent, characterized in that: Including the following raw materials by weight: Siloxane, 85 parts; of which hexenyl polydimethylsiloxane accounts for more than 80wt% and the rest is hydrogen-containing siloxane; Sulfonic acid acrylic monomer, (0.8–8) parts; precatalyst, (0.05–2) parts; catalyst support, (0.1–2) parts; initiator, (0.1–3) parts; The catalyst carrier is a multi-walled carbon nanotube, and the pre-catalyst is a platinum compound; the multi-walled carbon nanotube is any one of hydroxylated multi-walled carbon nanotube, carboxylated multi-walled carbon nanotube, amino multi-walled carbon nanotube and graphitized multi-walled carbon nanotube; The platinum compound is any one of K2PtCl4, H2PtCl6·6H2O, K2PtCl6, Pt (NH3)2Cl2 and K2[Pt(CN)4]·3H2O; The preparation method of the platinum-curing release agent comprises: mixing siloxane, a precatalyst, and a catalyst carrier according to a ratio, stirring and reacting them under visible light for a certain time, then adding a sulfonic acid acrylic monomer and an initiator, and mixing them again to obtain the release agent.

2. A platinum-curing release agent according to claim 1, characterized in that: The number average molecular weight of the siloxane is 200,000-800,000.

3. A platinum-curing release agent according to claim 1, characterized in that: The sulfonic acid acrylic monomer is at least one of 2-acrylamido-2-methyl-1-propanesulfonic acid, ethyl methacrylate sulfonate and sodium allyloxybenzenesulfonate.

4. A platinum-curing release agent according to claim 1, characterized in that: The initiator is at least one of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, benzophenone and 2-hydroxy-2-methyl-1-phenyl-1-propanone.

5. A platinum-curing release agent according to claim 1, characterized in that: The molecular structural formula of the catalyst carrier is as follows: 。 6. A release film, characterized in that: The invention comprises a substrate and a platinum-curing release agent according to any one of claims 1 to 5 coated on one side of the substrate.

7. The release film according to claim 6, characterized in that The substrate material is PET, and the thickness of the release agent layer is 20–48 μm.

8. The method for preparing the release film according to claim 6 or 7, characterized in that: The preparation method is: (1) Siloxane, precatalyst, and catalyst carrier are mixed according to the ratio and stirred under visible light for a certain time, and then sulfonic acid acrylic monomer and initiator are added and mixed again to obtain a release agent; (2) The release agent prepared in step (1) is evenly coated on the substrate with a certain thickness, and cured at a certain temperature to obtain a release film.

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