Release agent preparation method and release agent

Abstract

The invention relates to the technical field of organic silicon materials. The preparation method comprises the following steps: weighing main body organic silicon resin, a cross-linking agent, a catalyst, an adhesion promoter, a flatting agent, a heat-resistant stabilizer and a mixed solvent according to the weight percentage, adding the main body organic silicon resin and part of the mixed solvent into a reaction kettle, and stirring to obtain a premixed solution; adding a cross-linking agent and an adhesion promoter into the premixed liquid, heating and stirring, adding a catalyst, stirring to form a modified organic silicon prepolymer, adding a flatting agent and a heat-resistant stabilizer into the prepolymer, carrying out ultrasonic dispersion, heating and pre-curing the mixed system in stages, adding the residual mixed solvent, adjusting the solid content, and filtering to obtain a release agent finished product. According to the release agent disclosed by the invention, the modified polysiloxane main body is matched with the compound auxiliary agent, so that the interface bonding force with the PET base film, the heat-resistant stability and the coating uniformity are improved. The preparation process is adaptive to conventional equipment, and segmented pre-curing and ultrasonic dispersion ensure that the product batch is stable.

Description

Technical Field

[0001] This invention relates to the field of organosilicon materials technology, and in particular to a method for preparing a release agent and a release agent. Background Technology

[0002] Release agents are functional materials coated on the surface of a base film, widely used in hot stamping foil, self-adhesive labels, flexible circuit boards, and many other fields. Release agents for polyester base films, in particular, require high levels of interfacial adhesion, heat resistance, and coating uniformity due to the need to adapt to special processes such as high-temperature hot stamping. Currently, most commercially available release agents use ordinary unmodified polysiloxanes as the main raw material. In practical applications, these release agents often exhibit insufficient bonding strength with the polyester base film, leading to coating peeling and decomposition under high-temperature conditions. This directly results in incomplete transfer of the hot stamping pattern, reducing the yield rate of the final product.

[0003] Existing release agent formulations have several shortcomings. Crosslinking agents and adhesion promoters are often single-component blends, making it difficult to form a stable three-dimensional crosslinked network structure, resulting in poor coating mechanical strength and wear resistance. Some release agents fail to properly control the proportions of additives during preparation, failing to fully leverage the synergistic effect of leveling agents and heat stabilizers, easily leading to defects such as pinholes and sagging, and significant batch-to-batch performance fluctuations. Traditional preparation processes suffer from imprecise parameter settings, and the pre-curing treatment lacks segmented temperature control steps, further exacerbating the instability of release agent performance and failing to meet the large-scale application requirements of high-end hot stamping foil production. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention discloses a method for preparing a release agent that provides stable performance and meets the requirements for large-scale application in the production of high-end hot stamping foil, as well as a release agent itself.

[0005] This invention discloses a method for preparing a release agent, which includes the following steps:

[0006] Raw material weighing: Weigh the main organosilicon resin, crosslinking agent, catalyst, adhesion promoter, leveling agent, heat stabilizer and mixed solvent by weight percentage;

[0007] Premixed dispersion: The main organosilicon resin and part of the mixed solvent are added to the reaction vessel and stirred to obtain a premixed solution;

[0008] Construction of modified crosslinking system: Add crosslinking agent and adhesion promoter to premixed liquid, heat and stir, then add catalyst and continue stirring to form modified organosilicon prepolymer;

[0009] Functional additive compounding: Add leveling agent and heat-resistant stabilizer to modified organosilicon prepolymer and disperse by ultrasonication;

[0010] Pre-curing treatment: The obtained mixture is pre-treated by segmented heating, then the remaining mixed solvent is added to adjust the solid content, and the product is obtained after filtration.

[0011] Furthermore, the main organosilicon resin is a modified polysiloxane containing vinyl and phenyl groups, with a molecular weight of 5000-15000, a phenyl molar content of 10-30%, a viscosity of 500-2000 mPa·s at 25°C, and a vinyl mass content of 0.5-2 wt%.

[0012] Furthermore, based on the total weight of the raw materials, the weight percentage of each component is as follows:

[0013] Main organosilicon resin: 40-58 wt%

[0014] Mixed solvent: 28-45 wt%

[0015] Crosslinking agent: 2-8 wt%

[0016] Adhesion promoter: 1-6 wt%;

[0017] Heat stabilizer: 0.5-3 wt%;

[0018] Leveling agent: 0.1-3 wt%;

[0019] Catalyst: 0.1-2 wt%

[0020] The sum of the contents of each component is 100 wt%.

[0021] Furthermore, the crosslinking agent is at least one of hydrogen-containing silicone oil, tetraethyl orthosilicate, and methyltrimethoxysilane;

[0022] When the crosslinking agent is hydrogen-containing silicone oil, its hydrogen content is 0.5-1.5wt% and its viscosity at 25℃ is 100-500mPa·s.

[0023] Furthermore, the catalyst is a platinum catalyst or an organotin compound;

[0024] When the catalyst is platinum, the platinum content is 500-2000 ppm and the addition amount is 0.1-0.5 wt%; when the catalyst is an organotin compound, it is selected from at least one of dibutyltin dilaurate and stannous octoate and the addition amount is 0.5-2 wt%.

[0025] Furthermore, the adhesion promoter is a compound of epoxy silane coupling agent and amino silane coupling agent, with a mass ratio of 1:1 to 3:1;

[0026] The leveling agent is a polyether-modified polysiloxane.

[0027] Furthermore, the heat stabilizer is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and phosphite antioxidants, with a mass ratio of 1:1 to 2:1.

[0028] Furthermore, the process parameters for premixing and dispersing are as follows: add 50-70% of the mixed solvent, stir at a speed of 300-600 r / min, at a temperature of 40-60℃, and for a stirring time of 20-40 min;

[0029] The ultrasonic dispersion power is 200-400W, the frequency is 20-40kHz, and the ultrasonic time is 15-25min;

[0030] The pre-cooking process is as follows: first, treat at 40-50℃ for 1-2 hours, then raise the temperature to 50-60℃ and treat for 1-4 hours;

[0031] The filtration accuracy is ≤5μm;

[0032] The solid content of the finished release agent is 15-30%, and the viscosity at 25℃ is 80-150 mPa·s.

[0033] This invention discloses a release agent, which comprises a product prepared by any of the methods described above.

[0034] Furthermore, after the release agent forms a dry film on the PET base film, its interfacial bonding strength with the base film is ≥1.5N / 25mm.

[0035] The beneficial effects of this invention are:

[0036] This invention improves the performance of release agents by controlling the raw material formulation and component ratio. Modified polysiloxanes containing vinyl and phenyl groups serve as the main resin, forming a dense and stable three-dimensional cross-linked network structure. Combined with an adhesion promoter formulated with epoxy and aminosilane coupling agents, it enhances the interfacial bonding between the release agent and the PET base film, completely solving the problem of traditional release agents easily detaching under high-temperature conditions. The formulated heat-resistant stabilizer blocks the thermo-oxidative aging process through multiple pathways, while the polyether-modified polysiloxane leveling agent optimizes coating smoothness and reduces coating defects such as pinholes and sagging, giving the release agent both excellent heat resistance and coating performance.

[0037] The preparation process of this invention is compatible with conventional chemical production equipment, requiring no additional specialized equipment and effectively reducing equipment investment costs for large-scale production. Segmented pre-curing treatment enhances the chemical stability of the modified organosilicon prepolymer, avoiding performance fluctuations caused by temperature changes during subsequent drying. Ultrasonic dispersion disperses functional additives to the micron level, ensuring uniform distribution of all components. Combined with controllable stirring speed, temperature, and other process parameters, it guarantees batch-to-batch performance consistency, reduces scrap rates during production, and achieves stable and efficient mass production.

[0038] The release agent prepared by this invention exhibits significant advantages in practical applications, particularly suited to high-temperature hot stamping processes. The release agent coating does not decompose, yellow, or crack under 200°C conditions, ensuring complete and clear transfer of the hot stamping pattern, with a pattern transfer rate exceeding 99%. Simultaneously, the optimized formula and process endow the release agent with excellent weather resistance and mechanical strength, extending product lifespan and meeting the application requirements of high-end hot stamping foil, flexible circuit boards, and other fields, thus contributing to the improvement of end-product quality and market competitiveness. Attached Figure Description

[0039] Figure 1 This is a flowchart of a release agent preparation method according to an embodiment of this application. Detailed Implementation

[0040] To enable those skilled in the art to better understand the present invention, the technical solutions in the specific embodiments of the present invention will be clearly and completely described below.

[0041] This invention discloses a method for preparing a release agent, which includes the following steps:

[0042] Raw material weighing: Weigh the main organosilicon resin, crosslinking agent, catalyst, adhesion promoter, leveling agent, heat stabilizer and mixed solvent by weight percentage;

[0043] Premixed dispersion: The main organosilicon resin and part of the mixed solvent are added to the reaction vessel and stirred to obtain a premixed solution;

[0044] Construction of modified crosslinking system: Add crosslinking agent and adhesion promoter to premixed liquid, heat and stir, then add catalyst and continue stirring to form modified organosilicon prepolymer;

[0045] Functional additive compounding: Add leveling agent and heat-resistant stabilizer to modified organosilicon prepolymer and disperse by ultrasonication;

[0046] Pre-curing treatment: The obtained mixture is pre-treated by segmented heating, then the remaining mixed solvent is added to adjust the solid content, and the product is obtained after filtration.

[0047] Release agent preparation can be achieved using conventional chemical production equipment. The main silicone resin and a portion of the mixed solvent are added in a standard reactor according to a specified ratio and premixed and dispersed using a mechanical stirrer to form a homogeneous premixed liquid. Then, a crosslinking agent and adhesion promoter are added, and the temperature is controlled at 80-100℃ with stirring. After sufficient reaction, a catalyst is added and stirring continues to form a stable modified silicone prepolymer. Next, a leveling agent and a heat-resistant stabilizer are added to the prepolymer and dispersed using an ultrasonic dispersion device to ensure uniform distribution of the additives. The resulting mixture is then subjected to staged heating pretreatment, followed by the addition of the remaining mixed solvent to adjust the solid content. After filtration, the final release agent product is obtained.

[0048] The silicone-based formulation ensures excellent release properties. The synergistic effect of the crosslinking agent and adhesion promoter enhances the adhesion between the release agent and the PET base film, avoiding the problem of easy peeling of traditional release agents. The addition of a leveling agent makes the release agent coating more uniform, reducing pinholes and unevenness; the heat stabilizer improves the stability of the release agent during multi-stage temperature gradient drying. Pre-curing treatment ensures the chemical stability of the release agent, avoiding performance fluctuations caused by temperature changes during subsequent drying. The final release agent coating is uniform and stable, ensuring the complete transfer of patterns during hot stamping, while avoiding solvent residue and coating peeling, significantly improving the overall quality and production stability of the hot stamping foil.

[0049] As one implementation method, the main organosilicon resin is a modified polysiloxane containing vinyl and phenyl groups, with a molecular weight of 5000-15000, a phenyl molar content of 10-30%, a viscosity of 500-2000 mPa·s at 25°C, and a vinyl mass content of 0.5-2 wt%.

[0050] The main organosilicon resin can be prepared using conventional equipment in existing organosilicon chemical production lines, without the need for additional specialized equipment. During production, vinyl-containing siloxane monomers and phenyl-containing siloxane monomers are first added to a polymerization reactor in a preset ratio. After adding a suitable catalyst, the temperature and stirring rate within the reactor are adjusted to initiate the copolymerization reaction. During the reaction, the degree of polymerization is monitored in real time, and the reaction time is controlled to ensure the product molecular weight remains stable between 5000 and 15000. After the reaction, the product is transferred to a vacuum distillation unit for purification to remove unreacted monomers and impurities. Subsequently, the monomer ratio is adjusted based on the test results to ensure that the final product has a phenyl molar content of 10% to 30% and a vinyl content of 0.5% to 2 wt%. Finally, the purified resin is placed in a constant temperature environment at 25°C, and its viscosity is measured using a rotational viscometer. By fine-tuning the solid content of the system, the viscosity value is ensured to remain stable between 500 and 2000 mPa·s. The entire preparation process can be seamlessly integrated with the subsequent release agent production process. Each step, including feeding, reaction, purification, and testing, follows standardized operating procedures, which can effectively ensure that the performance parameters of each batch of resin are consistent and meet the needs of large-scale production.

[0051] The vinyl groups in the resin provide ample active sites for subsequent cross-linking reactions, ensuring a thorough and uniform cross-linking process. This helps form a dense and stable three-dimensional network structure, preventing pinholes and shrinkage defects in the release agent coating due to insufficient cross-linking, or brittleness and easy peeling due to excessive cross-linking. The introduction of phenyl groups enhances the resin's thermal stability and weather resistance, allowing the release agent to withstand temperature shocks during high-temperature hot stamping processes without decomposition or deformation, effectively extending its service life. The controlled molecular weight and viscosity parameters balance the resin's flexibility and mechanical strength, preventing cracking and damage during repeated peeling, while also adapting to PET base film coating processes. This allows the resin solution to spread quickly and evenly on the base film surface during coating, reducing coating defects such as bubbles and sagging, and enhancing the initial adhesion between the coating and the base film. In practical applications, this resin can lay a good foundation for the construction of subsequent modified crosslinking systems, help the prepared release agent to ensure the complete and clear transfer of patterns in the hot stamping process, reduce the scrap rate caused by poor coating performance, and improve the batch stability of products.

[0052] As one implementation method, based on the total weight of the raw materials, the weight percentage of each component is as follows: main organosilicon resin: 40-58wt%; mixed solvent: 28-45wt%; crosslinking agent: 2-8wt%; adhesion promoter: 1-6wt%; heat stabilizer: 0.5-3wt%; leveling agent: 0.1-3wt%; catalyst: 0.1-2wt%; and the sum of the contents of each component is 100wt%.

[0053] The feeding process utilizes the standard reactors of existing chemical production lines, requiring no additional specialized equipment and perfectly adapting to conventional production processes. During operation, the main silicone resin is first added to the reactor, followed by the mixed solvent, crosslinking agent, and adhesion promoter in sequence. Mechanical stirring is then activated for initial mixing. Once the materials are uniformly mixed, heat stabilizer, leveling agent, and catalyst are added sequentially, maintaining stirring throughout the process. The entire process can be controlled by the production line's automated control system, adjusting the amount and timing of each component addition to avoid human error, ensuring consistency in raw material ratios for each batch, and seamlessly integrating with subsequent premixing, dispersion, modification, and crosslinking processes without adding any extra production steps.

[0054] A 40-58 wt% ratio ensures the basic release properties of the release agent, laying the foundation for the complete transfer of patterns in subsequent hot stamping processes. A 28-45 wt% mixed solvent ratio completely dissolves the main resin and various additives while controlling the viscosity of the release agent to suit the coating process, avoiding issues of excessively thick or thin coatings. The proportions of crosslinking agents and adhesion promoters are controlled within a reasonable range; their synergistic effect effectively enhances the interfacial bonding between the release agent and the PET base film, solving the problem of easy coating peeling in traditional release agents. The proportions of heat stabilizers, leveling agents, and other additives are controlled in a low range, allowing the leveling agent to optimize coating smoothness and reduce pinhole defects, while the heat stabilizer enhances the high-temperature resistance of the release agent without interfering with the core function of the main components. Simultaneously, the scientifically proportioned components ensure high raw material utilization, reduce waste, lower production costs, and suitability for large-scale mass production, improving batch stability. Those skilled in the art can select solvents with good compatibility with the main silicone resin and various additives as the mixed solvent based on the characteristics of the release agent system. Optional solvents include two or more combinations of organic solvents such as toluene, xylene, ethyl acetate, n-heptane, and white spirit. Selection principles: The solvent must be completely miscible with the main silicone resin, have an evaporation rate suitable for the coating process, and leave no residual odor.

[0055] In one embodiment, the crosslinking agent is at least one of hydrogen-containing silicone oil, tetraethyl orthosilicate, and methyltrimethoxysilane; when the crosslinking agent is hydrogen-containing silicone oil, its hydrogen content is 0.5-1.5wt% and its viscosity at 25°C is 100-500 mPa·s.

[0056] The selection and feeding of crosslinking agents can be completed using existing release agent production lines, without the need for additional specialized equipment. During production, one or more of the following can be selected based on actual requirements: hydrogen-containing silicone oil, tetraethyl orthosilicate, and methyltrimethoxysilane. If hydrogen-containing silicone oil is selected, its hydrogen content must be tested beforehand using a gas chromatograph to ensure the value is within the range of 0.5 to 1.5 wt%, and the viscosity must be tested using a rotational viscometer at a constant temperature of 25°C to ensure the value is within the range of 100 to 500 mPa·s. The feeding process takes place during the modified crosslinking system construction stage. The selected crosslinking agent and adhesion promoter are added to the reactor according to the specified ratio and thoroughly mixed with the premixed liquid. The entire process can be completed using conventional metering pumps and stirring equipment. The feeding speed and stirring rate can be flexibly adjusted according to the automated control system of the production line to ensure that the crosslinking agent is uniformly dispersed in the system and in full contact with the main organosilicon resin.

[0057] Hydrogen-containing silicone oil, tetraethyl orthosilicate, and methyltrimethoxysilane are all mature organosilicon crosslinking agents with good compatibility with the host organosilicon resin, high crosslinking efficiency, and the ability to quickly form a stable three-dimensional network structure, enhancing the mechanical strength and wear resistance of the release agent coating. When using hydrogen-containing silicone oil, the controlled hydrogen content and viscosity parameters ensure sufficient crosslinking reaction without causing brittleness due to excessively rapid crosslinking. It also adapts to the stirring process of the reaction vessel, avoiding uneven local crosslinking. The design with multiple crosslinking agents can meet the needs of different application scenarios; for example, tetraethyl orthosilicate can improve the hardness of the coating, while methyltrimethoxysilane can enhance the water resistance of the coating. The final release agent coating is tightly bonded to the PET base film, making it less prone to peeling off during high-temperature hot stamping processes, ensuring complete pattern transfer, improving batch consistency, and reducing the scrap rate in the production process.

[0058] In one embodiment, the catalyst is a platinum catalyst or an organotin compound; when it is a platinum catalyst, the platinum content is 500-2000 ppm and the addition amount is 0.1-0.5 wt%; when it is an organotin compound, it is selected from at least one of dibutyltin dilaurate and stannous octoate and the addition amount is 0.5-2 wt%.

[0059] The selection and feeding of catalysts can be completed using existing release agent production lines, without the need for additional specialized equipment. During production, platinum catalysts or organotin compounds are selected based on actual production needs. If platinum catalysts are used, their platinum content must be tested in advance using an atomic absorption spectrometer to ensure the value is stable within the range of 500 to 2000 ppm, and then the addition amount is determined according to a ratio of 0.1 to 0.5 wt%. If organotin compounds are used, one or a mixture of dibutyltin dilaurate or stannous octoate is selected directly, and the dosage is prepared at a ratio of 0.5 to 2 wt%. The feeding process takes place during the construction stage of the modified crosslinking system. After the crosslinking agent, adhesion promoter, and premix have fully reacted, a metered amount of catalyst is added to the reactor through the metering pump of the production line. The stirring equipment is started to maintain the original speed, allowing the catalyst to be evenly dispersed in the system and fully contacted with the modified organosilicon prepolymer, triggering and regulating the crosslinking reaction process. The entire operation process can be seamlessly integrated with existing production steps. The timing and amount of feeding are controlled by an automated control system to avoid human error and ensure consistent reaction conditions for each batch.

[0060] Platinum catalysts possess ultra-high activity, efficiently triggering cross-linking reactions with extremely low addition amounts. The reaction process is gentle and controllable, preventing coating brittleness or pinhole defects caused by excessively rapid local reactions. The resulting release agent coating is dense and uniform, making it particularly suitable for the refined production of high-end hot stamping foil. Organotin compounds offer advantages such as low cost and strong reaction stability. Slightly higher addition amounts ensure complete cross-linking reactions, and they have relatively relaxed production environment requirements, making them more suitable for large-scale mass production. Both catalysts are perfectly compatible with the host silicone resin and cross-linking agent, ensuring stable formation of the cross-linked network structure and significantly improving the mechanical strength of the release agent coating and its interfacial adhesion to the PET base film. In subsequent high-temperature hot stamping processes, the cross-linked structure formed with the participation of the catalyst resists temperature shocks, preventing coating peeling or decomposition, reducing production scrap rates, and improving batch consistency.

[0061] In one implementation method, the adhesion promoter is a compound of epoxy silane coupling agent and amino silane coupling agent, with a mass ratio of 1:1 to 3:1; the leveling agent is polyether modified polysiloxane.

[0062] The compounding of adhesion accelerators and leveling agents can be completed using existing release agent production lines, without the need for additional specialized equipment. During production, epoxy-based silane coupling agents and amino-based silane coupling agents are weighed at a mass ratio of 1:1 to 3:1 using a high-precision electronic scale and added to a mixing tank. Mechanical stirring is then activated to thoroughly mix them, resulting in a uniform adhesion accelerator compound. The leveling agent is directly selected from finished polyether-modified polysiloxane products, requiring no additional processing. The feeding process is divided into two steps. During the modified crosslinking system construction stage, the adhesion accelerator compound is added to the premixed liquid along with the crosslinking agent, maintaining the original stirring speed of the reactor to ensure uniform dispersion. The leveling agent is added during the functional additive compounding stage, along with the heat-resistant stabilizer, to the modified organosilicon prepolymer. Subsequently, ultrasonic dispersion equipment is activated, and dispersion is completed according to a predetermined power and frequency. The entire operation process seamlessly integrates with existing production steps. An automated control system controls the material ratio and feeding timing, avoiding human error and ensuring stable product performance.

[0063] The adhesion promoter employs a compound of two silane coupling agents. The synergistic effect of epoxy and amino groups allows them to simultaneously form stable chemical bonds with both the main silicone resin and the surface groups of the PET base film, enhancing the interfacial adhesion between the release agent coating and the base film. This completely solves the problem of traditional release agents easily detaching during high-temperature hot stamping. The polyether-modified polysiloxane leveling agent possesses excellent surface activity, effectively reducing the surface tension of the release agent solution, allowing the coating to spread rapidly on the PET base film surface, reducing coating defects such as pinholes, craters, and runs, and forming a uniform and smooth dry film. Simultaneously, this leveling agent exhibits good compatibility with the silicone resin system, does not interfere with the crosslinking reaction process, and also improves the weather resistance of the coating. The resulting release agent ensures complete and clear pattern transfer during the hot stamping process, extends product lifespan, improves batch consistency, and reduces production scrap rates.

[0064] As one implementation method, the heat stabilizer is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and a phosphite antioxidant, with a mass ratio of 1:1 to 2:1.

[0065] The compounding and feeding of heat stabilizers can be completed using existing release agent production lines, without the need for additional specialized equipment. During production, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and phosphite antioxidants are weighed separately at a mass ratio of 1:1 to 2:1 using a high-precision electronic scale. The two raw materials are added to a mixing tank, and a mechanical stirrer is started, maintaining a stirring speed of 300 to 500 rpm for 15 to 20 minutes to obtain a homogeneous heat stabilizer compound. The feeding process takes place during the functional additive compounding stage. The compounded heat stabilizer and leveling agent are added together to the modified silicone prepolymer, and then an ultrasonic dispersion device is activated to complete the dispersion process at a predetermined power and frequency. The entire operation seamlessly integrates with existing production steps. An automated control system controls the material ratio and feeding timing, avoiding human error and ensuring stable product performance.

[0066] Pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] effectively captures free radicals and inhibits oxidative chain reactions, while phosphite antioxidants decompose hydroperoxides. The combination of these two agents blocks the thermo-oxidative aging process through different pathways. In high-temperature hot stamping processes, this compound stabilizer prevents the release agent coating from decomposing, yellowing, or cracking due to high temperatures, maintaining the stability of the coating structure. Simultaneously, this stabilizer exhibits excellent compatibility with silicone resin systems, does not interfere with crosslinking reactions, and does not affect the adhesion between the release agent and the PET base film. The resulting release agent maintains stable performance during multi-stage temperature gradient drying, effectively extending product lifespan and reducing the scrap rate under high-temperature conditions.

[0067] As one implementation method, the premixed dispersion process parameters are as follows: add 50-70% of the mixed solvent, stir at a speed of 300-600 r / min, a temperature of 40-60℃, and a stirring time of 20-40 min; the ultrasonic dispersion power is 200-400 W, the frequency is 20-40 kHz, and the ultrasonic time is 15-25 min; the pre-curing treatment process is as follows: first treat at 40-50℃ for 1-2 h, then raise the temperature to 50-60℃ for 1-4 h; the filtration accuracy is ≤5 μm; the solid content of the release agent is 15-30%, and the viscosity at 25℃ is 80-150 mPa·s.

[0068] In the premixing and dispersion stage, the main silicone resin and 50-70% of the total mixed solvent are added to a standard reactor. A mechanical stirrer is used at a speed of 300-600 rpm, and the temperature is raised to 40-60°C. Stirring is continued for 20-40 minutes to obtain a homogeneous premix. In the ultrasonic dispersion stage, leveling agent and heat stabilizer are added to the prepolymer, and an ultrasonic dispersion device with a power of 200-400W and a frequency of 20-40kHz is started for 15-25 minutes. The pre-curing treatment utilizes the reactor's segmented temperature control function. The temperature is first maintained at 40-50°C for 1-2 hours, then raised to 50-60°C for another 1-4 hours. The subsequent filtration stage uses a precision filter with a filtration accuracy of ≤5μm. Finally, the remaining mixed solvent is added to adjust the solid content of the finished product to 15-30%. The viscosity is tested at 25°C, ensuring it is between 80-150 mPa·s. The entire process is controlled by the production line's automated control system, which manages the parameters of each stage.

[0069] Premixing and dispersion parameters ensure thorough integration of the main resin and solvent, preventing localized defects in subsequent crosslinking reactions due to uneven mixing. Optimized ultrasonic dispersion power and frequency disperse functional additives to the micron level, ensuring uniform coating performance. Segmented pre-curing treatment allows for complete prepolymer reaction, enhancing chemical stability and preventing performance fluctuations due to temperature changes during subsequent drying. High-precision filtration effectively removes impurities from the system, preventing pinholes or defects during coating. The finished product's solids content and viscosity parameters are optimized for PET film coating processes, ensuring uniform coating thickness and improving coating efficiency. The resulting release agent exhibits stable overall performance, demonstrating excellent performance in high-temperature hot stamping processes and reducing production scrap rates.

[0070] Example 1

[0071] Weigh the raw materials (by weight percentage, total 1000g).

[0072] Main organosilicon resin: 40wt%, modified polysiloxane containing vinyl and phenyl, molecular weight 5000, phenyl molar content 10%, viscosity at 25℃ 500mPa・s, vinyl mass content 0.5wt%.

[0073] Mixed solvent: 38wt%

[0074] Crosslinking agent: 8wt%, hydrogen-containing silicone oil, hydrogen content 0.5wt%, viscosity at 25℃ 100mPa・s.

[0075] Adhesion promoter: 6wt%, epoxy silane coupling agent: amino silane coupling agent = 1:1.

[0076] Heat stabilizer: 3wt%, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]: phosphite antioxidant = 1:1.

[0077] Leveling agent: 3wt%, polyether-modified polysiloxane.

[0078] Catalyst: 2wt%, dibutyltin dilaurate.

[0079] Process parameters

[0080] Premixed dispersion: Add 50% mixed solvent, stir at 300 r / min, temperature 40℃, time 40 min.

[0081] Ultrasonic dispersion: power 200W, frequency 20kHz, time 25min.

[0082] Pre-cooking treatment: 40℃ for 2 hours, then heated to 50℃ for 4 hours.

[0083] Filtration: Filtration accuracy 5μm.

[0084] Finished product adjustment: Add the remaining mixed solvent, solid content 15%, viscosity 80 mPa·s at 25℃.

[0085] Finished product performance: PET base film interfacial bonding strength 1.8N / 25mm.

[0086] Example 2

[0087] Weigh the raw materials (by weight percentage, total 1000g).

[0088] Main silicone resin: 40wt%, molecular weight 15000, phenyl molar content 30%, viscosity at 25℃ 2000mPa・s, vinyl content 2wt%.

[0089] Mixed solvent: 45.4 wt%.

[0090] Crosslinking agent: 2wt%, tetraethyl orthosilicate.

[0091] Adhesion promoter: 1 wt%, epoxy silane coupling agent: amino silane coupling agent = 3:1.

[0092] Heat stabilizer: 0.5wt%, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]: phosphite antioxidant = 2:1.

[0093] Leveling agent: 0.1 wt%, polyether modified polysiloxane.

[0094] Catalyst: 0.1 wt%, platinum catalyst, platinum content 2000 ppm.

[0095] Process parameters

[0096] Premixed dispersion: Add 70% mixed solvent, stir at 600 r / min, at 60℃, for 20 min.

[0097] Ultrasonic dispersion: power 400W, frequency 40kHz, time 15min.

[0098] Pre-cooking treatment: Treat at 50℃ for 1 hour, then raise the temperature to 60℃ and treat for 1 hour.

[0099] Filtration: Filtration accuracy 3μm.

[0100] Finished product conditioning: solid content 30%, viscosity at 25℃ 150mPa・s.

[0101] Finished product performance: PET base film interfacial bonding strength 2.5N / 25mm.

[0102] Example 3

[0103] Weigh the raw materials (by weight percentage, total 1000g).

[0104] Main silicone resin: 48wt%, molecular weight 10000, phenyl molar content 20%, viscosity at 25℃ 1200mPa・s, vinyl content 1.2wt%.

[0105] Mixed solvent: 37.4 wt%

[0106] Crosslinking agent: 5 wt%, methyltrimethoxysilane.

[0107] Adhesion promoter: 3.5wt%, epoxy silane coupling agent: amino silane coupling agent = 2:1.

[0108] Heat stabilizer: 1.8 wt%, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]: phosphite antioxidant = 1.5:1.

[0109] Leveling agent: 1.5wt%, polyether-modified polysiloxane.

[0110] Catalyst: 0.8 wt%, stannous octoate.

[0111] Process parameters

[0112] Premixed dispersion: Add 60% mixed solvent, stir at 450 r / min, at 50℃, for 30 min.

[0113] Ultrasonic dispersion: power 300W, frequency 30kHz, time 20min.

[0114] Pre-cooking treatment: 45℃ for 1.5h, then heated to 55℃ for 2.5h.

[0115] Filtration: Filtration accuracy 4μm.

[0116] Finished product conditioning: solid content 22%, viscosity at 25℃ 110 mPa·s.

[0117] Finished product performance: PET base film interfacial bonding strength 2.2N / 25mm.

[0118] Example 4

[0119] Weigh the raw materials (by weight percentage, total 1000g).

[0120] Main silicone resin: 52wt%, molecular weight 8000, phenyl molar content 25%, viscosity at 25℃ 1800mPa・s, vinyl content 1.8wt%.

[0121] Mixed solvent: 34wt%

[0122] Crosslinking agent: 4wt%, hydrogen-containing silicone oil + tetraethyl orthosilicate = 1:1, hydrogen content of hydrogen-containing silicone oil is 1.0wt%, viscosity at 25℃ is 300mPa・s.

[0123] Adhesion promoter: 4wt%, epoxy silane coupling agent: amino silane coupling agent = 1.2:1.

[0124] Heat stabilizer: 2.5wt%, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]: phosphite antioxidant = 1.8:1.

[0125] Leveling agent: 2.2 wt%, polyether modified polysiloxane.

[0126] Catalyst: 1.3wt%, platinum catalyst + dibutyltin dilaurate = 1:2, platinum content 1000ppm.

[0127] Process parameters

[0128] Premixed dispersion: Add 55% mixed solvent, stir at 500 r / min, temperature 48℃, time 25 min.

[0129] Ultrasonic dispersion: power 280W, frequency 25kHz, time 22min.

[0130] Pre-cooking treatment: 42℃ for 1.8h, then heated to 52℃ for 3h.

[0131] Filtration: Filtration accuracy 2μm.

[0132] Finished product conditioning: solid content 20%, viscosity at 25℃ 95mPa・s.

[0133] Finished product performance: PET base film interfacial bonding strength 2.3N / 25mm.

[0134] Example 5

[0135] Weigh the raw materials, by weight percentage, totaling 1000g.

[0136] Main silicone resin: 45wt%, molecular weight 12000, phenyl molar content 15%, viscosity at 25℃ 800mPa・s, vinyl content 0.8wt%.

[0137] Mixed solvent: 38wt%

[0138] Crosslinking agent: 6wt%, hydrogen-containing silicone oil + methyltrimethoxysilane = 2:1, hydrogen content of hydrogen-containing silicone oil is 1.5wt%, viscosity at 25℃ is 500mPa・s.

[0139] Adhesion promoter: 5wt%, epoxy silane coupling agent: amino silane coupling agent = 2.5:1.

[0140] Heat stabilizer: 3wt%, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]: phosphite antioxidant = 1.2:1.

[0141] Leveling agent: 2.5wt%, polyether-modified polysiloxane.

[0142] Catalyst: 0.5wt%, platinum catalyst, platinum content 500ppm.

[0143] Process parameters

[0144] Premixed dispersion: Add 65% mixed solvent, stir at 380 r / min, temperature 55℃, time 35 min.

[0145] Ultrasonic dispersion: power 350W, frequency 35kHz, time 18min.

[0146] Pre-cooking treatment: 48℃ for 1.2h, then heated to 58℃ for 1.8h.

[0147] Filtration: Filtration accuracy 5μm.

[0148] Finished product conditioning: solid content 28%, viscosity at 25℃ 130mPa・s.

[0149] Finished product performance: PET base film interfacial bonding strength 2.0N / 25mm.

[0150] Comparative Example 1

[0151] Weigh the raw materials (by weight percentage, total 1000g).

[0152] Main silicone resin: 65wt%, ordinary unmodified polysiloxane, molecular weight 3000, viscosity at 25℃ 300mPa・s.

[0153] Mixed solvent: 20wt%.

[0154] Crosslinking agent: 10wt%, single hydrogen-containing silicone oil, hydrogen content 0.3wt%, viscosity at 25℃ 80mPa・s.

[0155] Adhesion promoter: 2wt%, monoepoxysilane coupling agent.

[0156] Heat stabilizer: 1 wt%, a single phosphite antioxidant.

[0157] Leveling agent: 1 wt%, ordinary silicone oil.

[0158] Catalyst: 1 wt%, stannous octoate.

[0159] Process parameters

[0160] Premixed dispersion: Add 40% mixed solvent, stir at 200 r / min, temperature 30℃, time 15 min.

[0161] Ultrasonic dispersion: power 150W, frequency 15kHz, time 10min.

[0162] Pre-cooking treatment: Treat at 30℃ for 1 hour, then heat to 70℃ for 1 hour.

[0163] Filtration: Filtration accuracy 10μm.

[0164] Finished product conditioning: solid content 35%, viscosity 200 mPa·s at 25℃.

[0165] Finished product performance: PET base film interfacial bonding strength 0.8N / 25mm.

[0166] Comparative Example 2

[0167] Weigh the raw materials (by weight percentage, total 1000g).

[0168] Main organosilicon resin: 30wt%, containing vinyl-modified polysiloxane, molecular weight 20000, phenyl molar content 5%, vinyl content 0.3wt%.

[0169] Mixed solvent: 52.95 wt%.

[0170] Crosslinking agent: 1 wt%, monoethyl orthosilicate.

[0171] Adhesion promoter: 8wt%, epoxy silane coupling agent: amino silane coupling agent = 4:1.

[0172] Heat stabilizer: 4wt%, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]: phosphite antioxidant = 3:1.

[0173] Leveling agent: 4wt%, polyether-modified polysiloxane.

[0174] Catalyst: 0.05wt%, platinum catalyst, platinum content 300ppm.

[0175] Process parameters

[0176] Premixed dispersion: Add 80% mixed solvent, stir at 700 r / min, temperature 70℃, time 50 min.

[0177] Ultrasonic dispersion: power 500W, frequency 50kHz, time 30min.

[0178] Pre-cooking treatment: 60℃ for 3 hours, then heated to 80℃ for 5 hours.

[0179] Filtration: Filtration accuracy 8μm.

[0180] Finished product conditioning: solid content 10%, viscosity at 25℃ 60mPa・s.

[0181] Finished product performance: PET base film interfacial bonding strength 1.0N / 25mm.

[0182] Comparative Example 3

[0183] Weigh the raw materials, by weight percentage, totaling 1000g.

[0184] Main silicone resin: 50wt%, containing phenyl-modified polysiloxane, molecular weight 4000, phenyl molar content 8%, no vinyl groups.

[0185] Mixed solvent: 38.5 wt%.

[0186] Crosslinking agent: 5wt%, hydrogen-containing silicone oil, hydrogen content 2.0wt%, viscosity at 25℃ 600mPa・s.

[0187] Adhesion promoter: 3 wt%, single aminosilane coupling agent.

[0188] Heat stabilizer: 0.3 wt%, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid].

[0189] Leveling agent: 0.2wt%, ordinary acrylic leveling agent.

[0190] Catalyst: 3wt%, dibutyltin dilaurate.

[0191] Process parameters

[0192] Premixed dispersion: Add 50% mixed solvent, stir at 300 r / min, at 40℃, for 20 min.

[0193] No ultrasonic dispersion step, only mechanical stirring.

[0194] Pre-cooking treatment: directly heat to 60℃ and treat for 3 hours, without segmented heating.

[0195] Filtration: Filtration accuracy 15μm.

[0196] Finished product conditioning: solid content 25%, viscosity at 25℃ 120 mPa·s.

[0197] Finished product performance: PET base film interfacial bonding strength 0.9N / 25mm.

[0198] Performance Comparison

[0199]

[0200] Examples 1-5 were prepared using the raw material ratios and process parameters defined in the claims, and their overall performance was significantly better than that of Comparative Examples 1-3, which were prepared using conventional methods of the prior art.

[0201] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for preparing a release agent, characterized in that, Includes the following steps: Raw material weighing: Weigh the main organosilicon resin, crosslinking agent, catalyst, adhesion promoter, leveling agent, heat stabilizer and mixed solvent by weight percentage; Premixed dispersion: The main organosilicon resin and part of the mixed solvent are added to the reaction vessel and stirred to obtain a premixed solution; Construction of modified crosslinking system: Add crosslinking agent and adhesion promoter to premixed liquid, heat and stir, then add catalyst and continue stirring to form modified organosilicon prepolymer; Functional additive compounding: Add leveling agent and heat-resistant stabilizer to modified organosilicon prepolymer and disperse by ultrasonication; Pre-curing treatment: The obtained mixture is pre-treated by segmented heating, then the remaining mixed solvent is added to adjust the solid content, and the product is obtained after filtration.

2. The method for preparing a release agent according to claim 1, characterized in that: The main organosilicon resin is a modified polysiloxane containing vinyl and phenyl groups, with a molecular weight of 5000-15000, a phenyl molar content of 10-30%, a viscosity of 500-2000 mPa·s at 25℃, and a vinyl mass content of 0.5-2wt%.

3. The method for preparing a release agent according to claim 2, characterized in that: Based on the total weight of the raw materials, the weight percentage of each component is as follows: Main organosilicon resin: 40-58 wt% Mixed solvent: 28-45 wt% Crosslinking agent: 2-8 wt% Adhesion promoter: 1-6 wt%; Heat stabilizer: 0.5-3 wt%; Leveling agent: 0.1-3 wt%; Catalyst: 0.1-2 wt% The sum of the contents of each component is 100 wt%.

4. The method for preparing a release agent according to claim 1, characterized in that: The crosslinking agent is at least one of hydrogen-containing silicone oil, tetraethyl orthosilicate, and methyltrimethoxysilane; When the crosslinking agent is hydrogen-containing silicone oil, its hydrogen content is 0.5-1.5wt% and its viscosity at 25℃ is 100-500mPa·s.

5. The method for preparing a release agent according to claim 1, characterized in that: The catalyst is a platinum catalyst or an organotin compound; When the catalyst is platinum, the platinum content is 500-2000 ppm and the addition amount is 0.1-0.5 wt%; when the catalyst is an organotin compound, it is selected from at least one of dibutyltin dilaurate and stannous octoate and the addition amount is 0.5-2 wt%.

6. The method for preparing a release agent according to claim 1, characterized in that: The adhesion promoter is a compound of epoxy silane coupling agent and amino silane coupling agent, with a mass ratio of 1:1 to 3:

1. The leveling agent is a polyether-modified polysiloxane.

7. The method for preparing a release agent according to claim 1, characterized in that: The heat stabilizer is a compound of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] and phosphite antioxidants, with a mass ratio of 1:1 to 2:

1.

8. The method for preparing a release agent according to claim 1, characterized in that: The premixed dispersion process parameters are as follows: add 50-70% of the mixed solvent, stir at a speed of 300-600 r / min, at a temperature of 40-60℃, and for a stirring time of 20-40 min; The ultrasonic dispersion power is 200-400W, the frequency is 20-40kHz, and the ultrasonic time is 15-25min; The pre-cooking process is as follows: first, treat at 40-50℃ for 1-2 hours, then raise the temperature to 50-60℃ and treat for 1-4 hours; The filtration accuracy is ≤5μm; The solid content of the finished release agent is 15-30%, and the viscosity at 25℃ is 80-150 mPa·s.

9. A release agent, characterized in that, include: It is prepared by any one of the methods of claims 1 to 8.

10. A release agent according to claim 9, characterized in that: After the release agent forms a dry film on the PET base film, its interfacial bonding strength with the base film is ≥1.5N / 25mm.

Images