High performance polyester masterbatch for release films and process for the preparation thereof

Abstract

The application discloses polyester master batches for high-performance release films and a preparation method thereof, and the master batches are prepared by esterification and polycondensation of raw materials including terephthalic acid, ethylene glycol, micro-nano opening agents and stabilizers; the micro-nano opening agents are prepared by the following methods: S1, preparing sub-micron hollow mesoporous silica; S2, preparing nano-silica sol; S3, preparing mesoporous silica supported catalyst; and S4, preparing micro-nano opening agents. The polyester master batches for high-performance release films are in-situ synthesized by adding the micro-nano opening agents, the process is simpler than coating, the particle dispersion resistance is smaller than co-extrusion, and the dispersibility is better; the opening performance of the film is ensured by adding sub-micron particles (sub-micron hollow mesoporous silica), the spherulite growth is inhibited by adding nano-particles (nano-silica sol), the small crystal generation is promoted, and the optical performance of the film is enhanced.

Description

Technical Field

[0001] This invention relates to the field of polyester masterbatch materials, and in particular to a high-performance polyester masterbatch for release films and its preparation method. Background Technology

[0002] PET, or polyethylene terephthalate, is a high-performance thermoplastic polyester widely used in aerospace, food and medical, textile, packaging, electronics, and machinery industries. In 2024, my country's polyester production capacity reached 80 million tons per year. Currently, most PET polyester is used in the textile industry, resulting in relatively low added value. In recent years, with the increasing market share of electronic and electrical products, there has been a significant shortage of mid-to-high-end optical films in the domestic market. Therefore, developing polyester masterbatches for high-end optical films can improve the added value of PET products and has broad market prospects.

[0003] PET release film, also known as peeling film, release film, anti-stick film, separation film, etc., is now widely used in packaging, printing, flexible circuits, insulation products, adhesive products, die-cutting and punching processing and other industries. It is closely related to our lives. Optical release film is mostly used in electronic display screens, optical instruments and other fields. Compared with ordinary release film, optical release film has the characteristics of low haze, high transmittance and high definition.

[0004] PET release film consists of a polyester film and an anti-stick release layer. The anti-stick release layer is a release agent coating, mainly used for surface treatment of the PET substrate, including coating with silicone release agents, fluorinated release agents, or plasma treatment, to ensure stable release force on different substrates depending on the application. In addition to the surface release coating, the PET polyester base film must have anti-stick properties. This is usually achieved by adding anti-stick particles during the film-making process to increase the surface roughness of the film, thereby giving the polyester good slip and winding properties. In existing technologies, anti-stick particles are usually directly coated onto the base film; alternatively, chips and particles are co-extruded to prepare anti-stick masterbatch or synthesized by in-situ polymerization.

[0005] Patent CN 113978086 B uses an online coating method to obtain an easy-to-peel MLCC release film. This patent uses plasma to treat the film surface, which makes the adhesion between silicone oil and film better and the peelability of ceramic better. However, the stability of the MLCC release film obtained by the coating method is relatively poor, the distribution of silicone oil is not uniform, and the process steps are more complicated and the cost is higher.

[0006] Patent CN 114103360 A uses nano-graphite as an opening agent to prepare a masterbatch for preparing MLCC release film base film through melt extrusion. The process is simple, but the polyester system has a high viscosity during co-extrusion, making it difficult for particles to flow, migrate, and disperse. The poor uniformity makes it easy for particles to agglomerate and accumulate into large particles, resulting in a large surface roughness of the obtained release film.

[0007] Patent CN 113956448 A describes a method of hydrolyzing silica sol under weakly alkaline conditions to obtain larger particle sizes. After esterification, the silica sol is added to the reaction system, and in-situ polymerization yields a masterbatch. After granulation, casting, and stretching, the resulting film exhibits significantly improved anti-blocking properties. The submicron-sized silicon particles synthesized in this patent have low surface activity, making them less prone to aggregation. Furthermore, modification with a coupling agent achieves a uniform distribution of particles within the masterbatch, resulting in a film with good anti-blocking properties. However, the presence of numerous large-particle-size particles does not improve the polyester crystallinity, fails to reduce the spherulite ratio, and decreases the film's transmittance, increasing its haze and affecting its optical properties, thus limiting its application in optical display fields.

[0008] Patent CN 115894982 A describes the preparation of a nano-silica sol using a particle exchange method. The sol has a small particle size and good dispersibility. It is added to the reaction system during the esterification stage and then polymerized in situ to obtain a masterbatch. The nanoparticles can promote the formation of crystal nuclei and inhibit the growth of spherulites. The prepared film has good light transmittance, low haze, and low surface roughness. However, the gaps between the films are small, making them prone to adhesion. The film has poor anti-adhesion properties, which will affect winding and slitting.

[0009] As can be seen from the existing technologies above, both online coating and blending extrusion methods have certain limitations, while the nano and micro opening agents added separately in in-situ polymerization methods each have their own advantages and disadvantages. Summary of the Invention

[0010] The technical problem to be solved by this invention is to address the shortcomings of the prior art by providing a high-performance polyester masterbatch for release films and its preparation method: First, a micro / nano opening agent is prepared, using nanoparticles (nano-silica sol) to promote crystallization, inhibit spherulite growth, and improve optical performance; micron-sized mesoporous particles (submicron-sized hollow mesoporous silicon) are used to increase the inter-film porosity and improve the film opening performance; and nano-catalysts are in-situ loaded in the micron-sized mesoporous particles to carry out chain growth reactions within the pores, inhibiting the aggregation of nano-catalysts, improving the silicon particle end-capping efficiency, and further reducing film adhesion; then, the functional masterbatch is directly synthesized through in-situ polymerization, which is simpler than the coating method and has better particle dispersion than blending extrusion.

[0011] To achieve the above objectives, the technical solution adopted by the present invention is: a high-performance polyester masterbatch for release films, characterized in that it is prepared by esterification and polycondensation processes of raw materials including terephthalic acid, ethylene glycol, micro-nano opening agents, and stabilizers;

[0012] The micro / nano opening agent is prepared by the following method:

[0013] S1. Preparation of submicron hollow mesoporous silicon;

[0014] S2. Preparation of nano-silica sol;

[0015] S3. TiO2 and ZnO were loaded onto submicron hollow mesoporous silica to prepare a mesoporous silica-supported catalyst.

[0016] S4. Mix the nano-silica sol prepared in step S2 with the mesoporous silica-supported catalyst prepared in step S3 to prepare a micro / nano opening agent.

[0017] Preferably, the micro / nano opening agent is prepared by the following method:

[0018] S1. Preparation of submicron hollow mesoporous silicon:

[0019] Under stirring conditions, deionized water, ethanol, template agent, and ammonia were mixed evenly and stirred. An ethanol solution of silicon source was added dropwise, and the mixture was reacted, centrifuged, washed with water and alcohol, and then added to an acidic ethanol solution. The mixture was heated to reflux and dried to obtain submicron hollow mesoporous silicon.

[0020] S2. Preparation of nano-silica sol:

[0021] Add deionized water to an ethylene glycol solution of tetraethyl orthosilicate, then add acidic solution dropwise to adjust the pH to 3-4, heat and stir, add dispersant, continue stirring, raise the temperature, remove water from the system, and obtain nano silica sol;

[0022] S3. TiO2 and ZnO were loaded onto submicron hollow mesoporous silica to prepare a mesoporous silica-supported catalyst.

[0023] The submicron hollow mesoporous silica prepared in step S1 was added to an ethanol solution of Ti source and Zn source, and the reaction was refluxed under heating and stirring. After the reaction was completed, the mixture was centrifuged, water vapor was introduced into a closed environment, the temperature was raised, and after cooling to room temperature, it was maintained. Finally, it was supercritically dried to obtain a mesoporous silica supported catalyst.

[0024] S4. The nano-silica sol prepared in step S2 is mixed with the mesoporous silica-supported catalyst prepared in step S3 and ball-milled to prepare a micro / nano opening agent.

[0025] Preferably, step S1 specifically includes:

[0026] Under stirring conditions at 35-45℃, deionized water, ethanol, template agent, and ammonia water with a mass dispersion of 20-25% are mixed evenly and stirred for 15-60 min. An ethanol solution of silicon source is added dropwise, and the reaction is carried out for 18-30 h. After centrifugation, the mixture is washed with water and alcohol, and then added to an acidic ethanol solution. The mixture is refluxed at 70-90℃ for 8-12 h and dried to obtain submicron hollow mesoporous silicon.

[0027] Preferably, in step S1:

[0028] The mass ratio of deionized water to ethanol is 9:1 to 1:9.

[0029] The volume ratio of the sum of the volumes of deionized water and ethanol to that of ammonia is 150:1 to 50:1.

[0030] In the ethanol solution containing silicon, the mass fraction of silicon is 10-50%; the amount of silicon added accounts for 1-20% of the total mass of water and ethanol.

[0031] The silicon source includes a silicate ester and a silane coupling agent, with a molar ratio of silicate ester to silane coupling agent of 9:1 to 20:1; the silicate ester is tetraethyl orthosilicate, the silane coupling agent is at least one of bis(3-triethoxysilylpropyl)amine, bis-(γ-trimethoxysilylpropyl)amine, and N-phenylaminomethyltriethoxysilane, and the mercapto coupling agent is at least one of γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane;

[0032] The template agent is a cationic surfactant, and the molar ratio of silicon source to template agent is 10:1 to 60:1.

[0033] Preferably, the submicron-sized hollow mesoporous silicon particles have a particle size of 0.5–1 μm and a pore size of 5–15 nm.

[0034] Preferably, step S2 specifically includes:

[0035] At 30℃, deionized water was added to an ethylene glycol solution of tetraethyl orthosilicate, and then an acidic solution with a concentration of 0.1-0.8 mol / L was added dropwise to adjust the pH to 3-4. The mixture was heated and stirred, and then stirred at 50-80℃ for 1.5-6 hours. After that, a dispersant was added, and stirring was continued for 1-3 hours. The temperature was then raised to 110-130℃ to remove water from the system, thus obtaining nano-silica sol.

[0036] The ethylene glycol solution of tetraethyl orthosilicate contains 10–50 wt% tetraethyl orthosilicate, and the molar ratio of tetraethyl orthosilicate to added deionized water is ≥4.

[0037] The acidic solution is a deionized aqueous solution of at least one of HCl, HNO3, H2SO4, HClO4, HBr, and HI;

[0038] The dispersant is at least one of polyethylene glycol 200, polyethylene glycol 400, and polyethylene glycol 600.

[0039] Preferably, step S3 specifically includes:

[0040] The submicron hollow mesoporous silica prepared in step S1 was added to an ethanol solution of Ti and Zn sources. The mixture was heated to 70-90℃ with stirring and refluxed for 2-4 hours. After centrifugation and drying until the Ti source loading was 40-60 wt%, the mixture was placed in a sealed environment and steam was introduced. The pressure of the sealed environment was kept higher than atmospheric pressure. The temperature was raised to 110-130℃ and held for 15-60 minutes. The temperature was then lowered to room temperature and held for 15-60 minutes. Finally, the mixture was supercritically dried to obtain a mesoporous silica supported catalyst.

[0041] Preferably, in step S3, the Ti source is a titanate ester, specifically selected from at least one of tetramethyl titanate, tetraethyl titanate, n-butyl titanate, isopropyl titanate, and tetraisopropyl titanate; the Zn source is Zn(OH)2; the molar ratio of titanate ester to Zn(OH)2 is 1:2 to 1:6; and the mass ratio of the sum of the Ti source and Zn source to the mass of ethanol is 1:20 to 1:10.

[0042] Preferably, step S4 specifically includes:

[0043] The nano-silica sol prepared in step S2 is mixed with the mesoporous silica supported catalyst prepared in step S3, and ball-milled at 500-2000 rpm / min for 0.5-2 h to prepare a micro-nano opening agent.

[0044] Preferably, the molar ratio of terephthalic acid to ethylene glycol is 1.1:1 to 1.4:1, and the content of micro / nano opening agent in the raw material is 3000 to 10000 ppm.

[0045] Preferably, the stabilizer is one or more of phosphoric acid, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, triphenyl phosphite, phosphorous acid, and polyphosphoric acid, and the amount of stabilizer added is controlled according to the content of P in the raw material being 10-50 ppm.

[0046] This invention also provides a method for preparing high-performance polyester masterbatch for release films, comprising the following steps:

[0047] Terephthalic acid, ethylene glycol, and micro / nano opening agent are stirred evenly and added to a reaction vessel. After replacing the air with nitrogen, the temperature is raised to 220–245°C, and the esterification reaction is carried out under a pressure of 300–350 kPa. The progress of the esterification reaction is measured by the yield of water in the esterification product. When the esterification rate reaches 94%, the esterification is completed. A stabilizer is added to the vessel, and within 1 hour, the pressure inside the reaction vessel is gradually reduced from atmospheric pressure to 20–50 Pa using a vacuum pump. The temperature is raised to 270–285°C to carry out the polycondensation chain growth reaction. When the product in the vessel reaches the target viscosity, it is discharged, cooled, and pelletized to obtain high-performance polyester masterbatch for release film.

[0048] Preferably, the target viscosity is 0.6 to 0.65 dL / g.

[0049] The beneficial effects of this invention are:

[0050] 1. In the preparation of submicron hollow mesoporous silicon, this invention introduces a macromolecular silane coupling agent with polar groups. One end serves as the silicon source, generating spheres and channels, while the other polar group appears in the channels and surface. This can firmly bond the polar polyester molecular chains, making the silicon spheres firmly anchored to the polyester surface, making them less likely to fall off. Furthermore, longer molecular chains are less likely to undergo chain growth and participate in the reaction.

[0051] 2. This invention loads catalyst precursors onto the surface and within the pores of submicron hollow mesoporous silicon and generates catalysts in situ, enabling polymerized monomers or small molecular chains to undergo chain growth reactions within the pores. This reduces the number of small molecular chains, improves end-capping efficiency, reduces exposed molecular chains, and further reduces film adhesion. In-situ loading also inhibits the aggregation of nanocatalysts, broadens the molecular chain distribution, and improves masterbatch performance.

[0052] 3. In a high-temperature, sealed environment, Zn(OH)2 is dehydrated to produce ZnO. Because the pore size is small and there is capillary action, the water removed from Zn(OH)2 is not easily discharged. The water vapor is then liquefied by cooling and reacted with titanate. After the reaction, supercritical drying is performed to avoid damaging the pore structure and remove excess water and reaction residues from the pores.

[0053] 4. This invention synthesizes high-performance polyester masterbatch for release films in situ by adding micro-nano opening agents. The process is simpler than coating, the particle dispersion resistance is lower than co-extrusion, and the dispersibility is better. The opening performance of the film is guaranteed by adding submicron particles (submicron hollow mesoporous silicon), and the addition of nanoparticles (nano silica sol) can inhibit spherulite growth, promote the formation of small crystals, and enhance the optical properties of the film. Attached Figure Description

[0054] Figure 1 This is an SEM image of the brittle fracture section of the high-performance release film polyester masterbatch obtained in Example 2. Detailed Implementation

[0055] The present invention will be further described in detail below with reference to embodiments, so that those skilled in the art can implement it based on the description.

[0056] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0057] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials and reagents used in the following examples are commercially available. For examples where specific conditions are not specified, conventional conditions or conditions recommended by the manufacturer are followed. For reagents or instruments whose manufacturers are not specified, they are all commercially available products.

[0058] This invention provides a high-performance polyester masterbatch for release films, which is prepared by esterification and polycondensation processes of raw materials including terephthalic acid, ethylene glycol, micro / nano opening agents, and stabilizers.

[0059] The micro / nano opening agent is prepared by the following method:

[0060] S1. Preparation of submicron hollow mesoporous silicon;

[0061] S2. Preparation of nano-silica sol;

[0062] S3. TiO2 and ZnO were loaded onto submicron hollow mesoporous silica to prepare a mesoporous silica-supported catalyst.

[0063] S4. Mix the nano-silica sol prepared in step S2 with the mesoporous silica-supported catalyst prepared in step S3 to prepare a micro / nano opening agent.

[0064] In a preferred embodiment, the micro / nano opening agent is prepared by the following method:

[0065] S1. Preparation of submicron hollow mesoporous silicon:

[0066] Under stirring conditions, deionized water, ethanol, template agent, and ammonia were mixed evenly and stirred. An ethanol solution of silicon source was added dropwise, and the mixture was reacted, centrifuged, washed with water and alcohol, and then added to an acidic ethanol solution. The mixture was heated to reflux and dried to obtain submicron hollow mesoporous silicon.

[0067] Principle Explanation: In this step, a submicron hollow mesoporous silicon with grafted groups on the surface and in the pores is prepared by template method. During silicon preparation, a macromolecular silane coupling agent with polar groups is introduced. One end serves as the silicon source, generating spheres and pores, while the other polar group appears in the pores and on the surface. This can firmly bond the polar polyester molecular chains, making the silicon spheres firmly anchored to the polyester surface, not easy to fall off, and the longer molecular chains are less likely to undergo chain growth and participate in the reaction.

[0068] Step S1 allows adjustment of the pore size by adjusting the alcohol-to-water ratio; a lower alcohol-to-water ratio will generate a more abundant pore structure.

[0069] S2. Preparation of nano-silica sol:

[0070] Add deionized water to an ethylene glycol solution of tetraethyl orthosilicate, then add acidic solution dropwise to adjust the pH to 3-4, heat and stir, add dispersant, continue stirring, raise the temperature, remove water from the system, and obtain nano silica sol;

[0071] Explanation of principle: In this step, the silica obtained by hydrolyzing tetraethyl orthosilicate under acidic conditions is more stable and has a more controllable particle size than that obtained under alkaline conditions, and can be stored effectively.

[0072] S3. TiO2 and ZnO were loaded onto submicron hollow mesoporous silica to prepare a mesoporous silica-supported catalyst.

[0073] The submicron hollow mesoporous silica prepared in step S1 was added to an ethanol solution of Ti source and Zn source, and the reaction was refluxed under heating and stirring. After the reaction was completed, the mixture was centrifuged, water vapor was introduced into a closed environment, the temperature was raised, and after cooling to room temperature, it was maintained. Finally, it was supercritically dried to obtain a mesoporous silica supported catalyst.

[0074] Principle explanation: This step involves loading catalyst precursors onto the surface and within the pores of submicron silicon spheres and generating catalysts in situ. This allows polymerized monomers or small molecular chains to undergo chain growth reactions within the pores, reducing the number of small molecular chains, improving end-capping efficiency, reducing exposed molecular chains, and further reducing film adhesion. In-situ loading also inhibits the aggregation of nanocatalysts, broadens the molecular chain distribution, and improves masterbatch performance.

[0075] TiO2 is the main catalyst, but its activity is too high and difficult to control, resulting in poor reaction stability. The obtained polyester masterbatch is prone to yellowing, which affects the color value of the masterbatch. ZnO is used as a co-catalyst to regulate its catalytic activity and carry out synergistic catalysis.

[0076] In a high-temperature, enclosed environment, Zn(OH)2 dehydrates to form ZnO. Due to the small pore size and capillary action, the water removed by Zn(OH)2 is not easily discharged. The water vapor is then liquefied by cooling and reacts with titanate. After the reaction, supercritical drying is performed to avoid damaging the pore structure and remove excess water and reaction residues from the pores.

[0077] S4. The nano-silica sol prepared in step S2 is mixed with the mesoporous silica-supported catalyst prepared in step S3 and ball-milled to prepare a micro / nano opening agent.

[0078] In a preferred embodiment, step S1 specifically involves:

[0079] Under stirring conditions at 35-45℃, deionized water, ethanol, template agent, and ammonia water with a mass dispersion of 20-25% are mixed evenly and stirred for 15-60 min. An ethanol solution of silicon source is added dropwise, and the reaction is carried out for 18-30 h. After centrifugation, the mixture is washed with water and alcohol, and then added to an acidic ethanol solution. The mixture is refluxed at 70-90℃ for 8-12 h and dried to obtain submicron hollow mesoporous silicon.

[0080] In a preferred embodiment, in step S1:

[0081] The mass ratio of deionized water to ethanol is 9:1 to 1:9, more preferably 6:4;

[0082] The volume ratio of the sum of the volumes of deionized water and ethanol to that of ammonia is 150:1 to 50:1.

[0083] In the ethanol solution containing silicon, the mass fraction of silicon is 10-50%; the amount of silicon added accounts for 1-20% of the total mass of water and ethanol; more preferably 30%.

[0084] The silicon source includes a silicate ester and a silane coupling agent, with a molar ratio of silicate ester to silane coupling agent of 9:1 to 20:1; the silicate ester is tetraethyl orthosilicate, the silane coupling agent is at least one of bis(3-triethoxysilylpropyl)amine, bis-(γ-trimethoxysilylpropyl)amine, and N-phenylaminomethyltriethoxysilane, and the mercapto coupling agent is at least one of γ-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane;

[0085] The template agent is a cationic surfactant, and the molar ratio of silicon source to template agent is 10:1 to 60:1, more preferably 20:1 to 40:1.

[0086] In a preferred embodiment, the submicron-sized hollow mesoporous silicon particles have a diameter of 0.5–1 μm and a pore size between 5–15 nm.

[0087] In a preferred embodiment, step S2 specifically involves:

[0088] At 30℃, deionized water was added to an ethylene glycol solution of tetraethyl orthosilicate, and then an acidic solution with a concentration of 0.1-0.8 mol / L was added dropwise to adjust the pH to 3-4. The mixture was heated and stirred, and then stirred at 50-80℃ for 1.5-6 hours. A dispersant was added, and stirring was continued for 1-3 hours. The temperature was then raised to 110-130℃ to remove water from the system, thus obtaining nano-silica sol.

[0089] In a preferred embodiment, in step S2:

[0090] The tetraethyl orthosilicate content in the ethylene glycol solution of tetraethyl orthosilicate is 10–50 wt%.

[0091] The molar ratio of tetraethyl orthosilicate to added deionized water is ≥4;

[0092] The acidic solution is a deionized aqueous solution of at least one of HCl, HNO3, H2SO4, HClO4, HBr, and HI; more preferably HCl, and the concentration of the acidic solution is preferably 0.4 mol / L.

[0093] The dispersant is at least one of polyethylene glycol 200, polyethylene glycol 400, and polyethylene glycol 600. The mass ratio of nano-silicon to dispersant is 5:1 to 15:1, more preferably 10:1.

[0094] In a preferred embodiment, the particle size of the nano-silicon prepared in step S2 is 20–60 nm.

[0095] In a preferred embodiment, the temperature for heat preservation and stirring in step S2 is 60°C.

[0096] In a preferred embodiment, step S3 specifically involves:

[0097] The submicron hollow mesoporous silica prepared in step S1 was added to an ethanol solution of the catalyst precursors (Ti source and Zn source). The mixture was heated to 70-90℃ with stirring and refluxed for 2-4 hours. After centrifugation and drying until the Ti source loading was 40-60 wt%, the mixture was placed in a sealed environment and steam was introduced. The pressure of the sealed environment was kept higher than atmospheric pressure. The temperature was raised to 110-130℃ and held for 15-60 minutes. The temperature was then lowered to room temperature and held for 15-60 minutes. Finally, the mixture was supercritically dried to obtain the mesoporous silica supported catalyst.

[0098] In a preferred embodiment, in step S3:

[0099] The molar ratio of submicron hollow mesoporous silica to catalyst precursor is 12:1 to 20:1;

[0100] The Ti source is a titanate ester, specifically selected from at least one of tetramethyl titanate, tetraethyl titanate, n-butyl titanate, isopropyl titanate, and tetraisopropyl titanate. The Zn source is Zn(OH)2, and the molar ratio of titanate ester to Zn(OH)2 is 1:2 to 1:6. The mass ratio of the sum of the Ti source and Zn source to the mass of ethanol is 1:20 to 1:10.

[0101] In a preferred embodiment, step S4 specifically involves:

[0102] The nano-silica sol prepared in step S2 is mixed with the mesoporous silica supported catalyst prepared in step S3, and ball-milled at 500-2000 rpm / min for 0.5-2 h to prepare a micro-nano opening agent.

[0103] In a preferred embodiment, the molar ratio of terephthalic acid to ethylene glycol is 1.1:1 to 1.4:1, and the content of the micro / nano opening agent in the raw material is 3000 to 10000 ppm.

[0104] In a preferred embodiment, the stabilizer is one or more of phosphoric acid, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, triphenyl phosphite, phosphorous acid, and polyphosphoric acid, and the amount of stabilizer added is controlled according to the content of P in the raw material being 10-50 ppm.

[0105] In a preferred embodiment, the polyterephthalic acid is selected from China Hengli Petrochemical Co., Ltd., and the ethylene glycol is selected from imports from Saudi Arabia.

[0106] This invention also provides a method for preparing high-performance polyester masterbatch for release films, comprising the following steps:

[0107] Terephthalic acid, ethylene glycol, and micro / nano opening agent are stirred evenly and added to a reaction vessel. After replacing the air with nitrogen, the temperature is raised to 220–245°C, and the esterification reaction is carried out under a pressure of 300–350 kPa. The progress of the esterification reaction is measured by the yield of water in the esterification product. When the esterification rate reaches 94%, the esterification is completed. A stabilizer is added to the vessel, and within 1 hour, the pressure inside the reaction vessel is gradually reduced from atmospheric pressure to 20–50 Pa using a vacuum pump. The temperature is raised to 270–285°C to carry out the polycondensation chain growth reaction. When the product in the vessel reaches the target viscosity, it is discharged, cooled, and pelletized to obtain high-performance polyester masterbatch for release film.

[0108] In a preferred embodiment, the target viscosity is 0.6–0.65 dL / g.

[0109] The above is the general concept of the present invention. Based on this, detailed embodiments and comparative examples are provided below to further illustrate the present invention.

[0110] Example 1

[0111] S1. Preparation of submicron hollow mesoporous silicon:

[0112] Under stirring conditions at 40℃, 530.0g of deionized water, 434.0g of ethanol, 0.92g of hexadecyltrimethylammonium bromide, and 7ml of ammonia were mixed evenly and stirred for 0.5h. Then, a mixed solution of 9.5g of tetraethyl orthosilicate, 1.1g of bis(3-triethoxysilylpropyl)amine, and 96.0g of ethanol was added titrated. After reacting for 18h, the mixture was centrifuged, washed with water and alcohol, and then added to an acidic ethanol solution. The mixture was refluxed at 80℃ for 8h and dried to obtain submicron hollow mesoporous silica spheres.

[0113] S2. Preparation of nano-silica sol:

[0114] Prepare a 936.0 g solution of 10% tetraethyl orthosilicate in ethylene glycol. At 30°C, first add 32.4 g of deionized water, then add dropwise a 0.1 mol / L HCl solution until the pH of the solution is 3. After stirring at 50°C for 3 h, add 5.4 g of polyethylene glycol 200 and continue stirring for 1 h. Then raise the temperature to 120°C to remove water from the system, and obtain nano-silica sol.

[0115] S3. Preparation of mesoporous silica supported catalysts:

[0116] 3.0g of the submicron hollow mesoporous silica spheres obtained in step 1 were immersed in a mixed solution of 0.90g tetramethyl titanate, 1.23g Zn(OH)2 and 25.0g ethanol. The solution was heated to 80℃ under gentle stirring and refluxed for 2h. After centrifugation, the solution was dried until the theoretical loading of tetramethyl titanate reached 50% (by weighing). The solution was then placed in a closed environment, and water vapor was introduced to maintain the pressure of the closed environment slightly higher than atmospheric pressure. The solution was heated to 120℃ for about 0.5h, then cooled to room temperature and maintained for 0.5h. Finally, supercritical drying was performed to obtain the mesoporous silica supported catalyst.

[0117] S4. Preparation of micro / nano opening agents:

[0118] The mesoporous silica-supported catalyst obtained in step S3 was added to the nano-silica sol obtained in step S2, and ball-milled at 1000 rpm / min for 1 h to obtain a micro-nano opening agent.

[0119] S5. Polyester masterbatch for synthesizing high-performance release films:

[0120] 8.6 kg of terephthalic acid, 2.65 kg of ethylene glycol, and 945.0 g of micro / nano opening agent were stirred evenly and added to a 20 L batch reactor. After replacing the air with nitrogen, the temperature was raised to 240 °C and the esterification reaction was carried out under a pressure of 325 kPa. The progress of the esterification reaction was measured by the yield of water in the esterification product. When the esterification rate reached 94%, the esterification was completed. 0.26% trimethyl phosphate was added to the reactor. Within 1 hour, the pressure in the reactor was gradually reduced from atmospheric pressure to 35 Pa using a vacuum pump, and the temperature was raised to 280 °C to carry out the polycondensation chain growth reaction. When the product in the reactor reached 0.6 dL / g, the product was discharged, cooled, and pelletized to obtain high-performance polyester masterbatch for release film.

[0121] Example 2

[0122] S1. Preparation of submicron hollow mesoporous silicon:

[0123] Under stirring conditions at 40℃, 203.1g of deionized water, 182.0g of ethanol, 1.21g of hexadecyltrimethylammonium bromide, and 4.7ml of ammonia were mixed evenly and stirred for 0.5h. Then, a mixed solution of 19g of tetraethyl orthosilicate, 2.38g of γ-mercaptopropyltriethoxysilane, and 50.0g of ethanol was added titrated. After reacting at 100℃ for 24h, the mixture was centrifuged, washed with water and alcohol, and then added to an acidic ethanol solution. The mixture was refluxed at 80℃ for 10h and dried to obtain submicron hollow mesoporous silica spheres.

[0124] S2. Preparation of nano-silica sol:

[0125] Prepare a 624.0 g solution of 30% tetraethyl orthosilicate in ethylene glycol. At 30°C, first add 85.5 g of deionized water, then add dropwise a 0.4 mol / L HCl solution until the pH of the solution is 3-4. After stirring at 65°C for 3 h, add 18.7 g of polyethylene glycol 400 and continue stirring for 1 h. Then raise the temperature to 120°C to remove water from the system, and obtain nano-silica sol.

[0126] S3. Preparation of mesoporous silica supported catalysts:

[0127] 6.0g of the submicron hollow mesoporous silica spheres prepared in step 1 were immersed in a mixed solution of 1.06g of tetrabutyl titanate, 1.32g of Zn(OH)2 and 35.7g of ethanol. The solution was heated to 80℃ under gentle stirring and refluxed for 2h. After centrifugation, the solution was dried until the theoretical loading of tetramethyl titanate reached 50% (by weighing). The solution was then placed in a closed environment, and water vapor was introduced to maintain the pressure of the closed environment slightly higher than atmospheric pressure. The solution was heated to 120℃ for about 0.5h, then cooled to room temperature and maintained for 0.5h. Finally, supercritical drying was performed to obtain the silicon-based titanium catalyst.

[0128] S4. Preparation of micro / nano opening agents:

[0129] The mesoporous silica-supported catalyst obtained in step S3 was added to the nano-silica sol prepared in step 2, and ball-milled at 1000 rpm / min for 1 h to obtain a micro-nano opening agent.

[0130] S5. Polyester masterbatch for synthesizing high-performance release films:

[0131] 8.6 kg of terephthalic acid, 3.44 kg of ethylene glycol, and 650.0 g of micro-nano opening agent dispersion were stirred evenly and added to a 20 L batch reactor. After replacing the air with nitrogen, the temperature was raised to 240 °C and the esterification reaction was carried out under a pressure of 325 kPa. The progress of the esterification reaction was measured by the yield of water in the esterification product. When the esterification rate reached 94%, the esterification was completed. 2.0 g of triphenyl phosphite was added to the reactor. Within 1 hour, the pressure in the reactor was gradually reduced from atmospheric pressure to 35 Pa using a vacuum pump, and the temperature was raised to 280 °C to carry out the polycondensation chain growth reaction. When the product in the reactor reached a certain viscosity, it was discharged, cooled, and pelletized to obtain high-performance polyester masterbatch for release film.

[0132] Reference Figure 1 The image shown is an SEM image of the brittle fracture section of the high-performance release film polyester masterbatch obtained in Example 2.

[0133] Example 3

[0134] S1. Preparation of submicron hollow mesoporous silicon:

[0135] Under stirring conditions at 40℃, 153.5g of deionized water, 73.5g of ethanol, 1.52g of hexadecyltrimethylammonium bromide, and 6.13ml of ammonia were mixed evenly and stirred for 0.5h. Then, a mixed solution of 31.2g of tetraethyl orthosilicate, 2.9g of bis-(γ-trimethoxysilylpropyl)amine, and 80.0g of ethanol was added titrated. After reacting at 80℃ for 30h, the mixture was centrifuged, washed with water and alcohol, and then added to an acidic ethanol solution. The mixture was refluxed at 80℃ for 12h and dried to obtain submicron hollow mesoporous silica spheres.

[0136] S2. Preparation of nano-silica sol:

[0137] Prepare a 624.0 g solution of 50% tetraethyl orthosilicate in ethylene glycol. At 30°C, first add 162.0 g of deionized water, then add dropwise a 0.8 mol / L HCl solution until the pH of the solution is 3-4. After stirring at 50°C for 3 h, add 31.2 g of polyethylene glycol 600 and continue stirring for 1 h. Raise the temperature to 120°C to remove water from the system and obtain nano-silica sol.

[0138] S3. Preparation of mesoporous silica supported catalysts:

[0139] 9.0g of the submicron hollow mesoporous silica spheres prepared in step 1 were immersed in a mixed solution of 2.37g tetraisopropyl titanate, 3.72g Zn(OH)2 and 61.0g ethanol. The solution was heated to 80℃ under gentle stirring and refluxed for 2h. After centrifugation, the solution was dried until the theoretical loading of tetramethyl titanate reached 50% (by weighing). The solution was then placed in a closed environment, and water vapor was introduced to maintain the pressure of the closed environment slightly higher than atmospheric pressure. The solution was heated to 120℃ for about 0.5h, then cooled to room temperature and maintained for 0.5h. Finally, supercritical drying was performed to obtain the mesoporous silica supported catalyst.

[0140] S4. Preparation of micro / nano opening agents:

[0141] The mesoporous silica-supported catalyst obtained in step S3 was added to the nano-silica sol obtained in step S2, and ball-milled at 1000 rpm / min for 1 h to obtain a micro-nano opening agent.

[0142] S5. Polyester masterbatch for synthesizing high-performance release films:

[0143] 8.6 kg of terephthalic acid, 4.17 kg of ethylene glycol, and 660.6 g of micro / nano opening agent dispersion were stirred evenly and added to a 20 L batch reactor. After replacing the air with nitrogen, the temperature was raised to 240 °C and the esterification reaction was carried out under a pressure of 325 kPa. The progress of the esterification reaction was measured by the yield of water in the esterification product. When the esterification rate reached 94%, the esterification was completed. 3.0 g of triphenyl phosphate was added to the reactor. Within 1 hour, the pressure in the reactor was gradually reduced from atmospheric pressure to 35 Pa using a vacuum pump, and the temperature was raised to 280 °C to carry out the polycondensation chain growth reaction. When the product in the reactor reached 0.65 dL / g, the product was discharged, cooled, and pelletized to obtain high-performance polyester masterbatch for release film.

[0144] Comparative Example 1

[0145] S1. Preparation of submicron hollow mesoporous silicon:

[0146] Under stirring conditions at 40℃, 203.1g of deionized water, 182.0g of ethanol, 1.21g of hexadecyltrimethylammonium bromide, and 4.7ml of ammonia were mixed evenly and stirred for 0.5h. Then, a mixed solution of 19g of tetraethyl orthosilicate, 2.38g of γ-mercaptopropyltriethoxysilane, and 50.0g of ethanol was added titrated. After reacting at 100℃ for 24h, the mixture was centrifuged, washed with water and alcohol, and then added to an acidic ethanol solution. The mixture was refluxed at 80℃ for 10h and dried to obtain submicron hollow mesoporous silica spheres.

[0147] S2. Preparation of mesoporous silica supported catalysts:

[0148] 6.0g of the submicron hollow mesoporous silica spheres prepared in step 1 were immersed in a mixed solution of 1.06g of tetrabutyl titanate, 1.32g of Zn(OH)2 and 35.7g of ethanol. The solution was heated to 80℃ under gentle stirring and refluxed for 2h. After centrifugation, the solution was dried until the theoretical loading of tetramethyl titanate reached 50% (by weighing). The solution was then placed in a closed environment, and water vapor was introduced to maintain the pressure of the closed environment slightly higher than atmospheric pressure. The solution was heated to 120℃ for about 0.5h, then cooled to room temperature and maintained for 0.5h. Finally, supercritical drying was performed to obtain the mesoporous silica supported catalyst.

[0149] S3. Polyester masterbatch for synthesizing high-performance release films:

[0150] 8.6 kg of terephthalic acid, 3.82 kg of ethylene glycol, and 9.2 g of mesoporous silica-supported catalyst were stirred evenly and added to a 20 L batch reactor. After replacing the air with nitrogen, the temperature was raised to 240 °C, and the esterification reaction was carried out under a pressure of 325 kPa. The progress of the esterification reaction was measured by the yield of water in the esterification product. When the esterification rate reached 94%, the esterification was completed. 2.0 g of triphenyl phosphite was added to the reactor. Within 1 hour, the pressure in the reactor was gradually reduced from atmospheric pressure to 35 Pa using a vacuum pump, and the temperature was raised to 280 °C to carry out the polycondensation chain growth reaction. When the product in the reactor reached a certain viscosity, it was discharged, cooled, and pelletized to obtain high-performance polyester masterbatch for release films.

[0151] Comparative Example 2

[0152] S1. Preparation of nano-silica sol:

[0153] Prepare a 624.0 g solution of 30% tetraethyl orthosilicate in ethylene glycol. At 30°C, first add 85.5 g of deionized water, then add dropwise a 0.4 mol / L HCl solution until the pH of the solution is 3-4. After stirring at 65°C for 3 h, add 18.7 g of polyethylene glycol 400 and continue stirring for 1 h. Then raise the temperature to 120°C to remove water from the system, and obtain nano-silica sol.

[0154] S2. Polyester masterbatch for synthesizing high-performance release films:

[0155] 8.6 kg of terephthalic acid, 3.44 kg of ethylene glycol, 624.0 g of nano-silica sol, 35 ppm of n-butyl titanate, and 24 ppm of zinc oxide were stirred evenly and then added to a 20 L batch reactor. After replacing the air with nitrogen, the temperature was raised to 240 °C and the esterification reaction was carried out under a pressure of 325 kPa. The progress of the esterification reaction was measured by the yield of water in the esterification product. When the esterification rate reached 94%, the esterification was completed. 2.0 g of triphenyl phosphite was added to the reactor. Within 1 hour, the pressure in the reactor was gradually reduced from atmospheric pressure to 35 Pa using a vacuum pump, and the temperature was raised to 280 °C to carry out the polycondensation chain growth reaction. When the product in the reactor reached a certain viscosity, it was discharged, cooled, and pelletized to obtain high-performance polyester masterbatch for release film.

[0156] Comparative Example 3

[0157] S1. Preparation of submicron hollow mesoporous silicon:

[0158] Under stirring conditions at 40℃, 203.1g of deionized water, 182.0g of ethanol, 1.21g of hexadecyltrimethylammonium bromide, and 4.7ml of ammonia were mixed evenly and stirred for 0.5h. Then, a mixed solution of 19g of tetraethyl orthosilicate, 2.38g of γ-mercaptopropyltriethoxysilane, and 50.0g of ethanol was added titrated. After reacting at 100℃ for 24h, the mixture was centrifuged, washed with water and alcohol, and then added to an acidic ethanol solution. The mixture was refluxed at 80℃ for 10h and dried to obtain submicron hollow mesoporous silica spheres.

[0159] S12, Preparation of nano-silica sol

[0160] Prepare a 624.0 g solution of 30% tetraethyl orthosilicate in ethylene glycol. At 30°C, first add 85.5 g of deionized water, then add dropwise a 0.4 mol / L HCl solution until the pH of the solution is 3-4. After stirring at 65°C for 3 h, add 18.7 g of polyethylene glycol 400 and continue stirring for 1 h. Then raise the temperature to 120°C to remove water from the system, and obtain nano-silica sol.

[0161] S3. Polyester masterbatch for synthesizing high-performance release films:

[0162] 8.6 kg of terephthalic acid, 3.44 kg of ethylene glycol, 642.7 g of nano-silica sol, 6.0 g of submicron hollow mesoporous silica, 35 ppm of n-butyl titanate, and 24 ppm of zinc oxide were stirred evenly and then added to a 20 L batch reactor. After replacing the air with nitrogen, the temperature was raised to 240 °C and the esterification reaction was carried out under a pressure of 325 kPa. The progress of the esterification reaction was measured by the yield of water in the esterification product. When the esterification rate reached 94%, the esterification was completed. 2.0 g of triphenyl phosphite was added to the reactor. Within 1 hour, the pressure in the reactor was gradually reduced from atmospheric pressure to 35 Pa using a vacuum pump, and the temperature was raised to 280 °C to carry out the polycondensation chain growth reaction. When the product in the reactor reached a certain viscosity, it was discharged, cooled, and pelletized to obtain high-performance polyester masterbatch for release films.

[0163] Performance testing

[0164] The performance parameters of the high-performance release film polyester masterbatch obtained in Examples 1-3, the PET masterbatch obtained in Comparative Examples 1-3, and the chips were tested according to the national standard GB / T 14190-2017, and the results are shown in Table 1.

[0165] The high-performance release film polyester masterbatch obtained in Examples 1-3, the PET masterbatch obtained in Comparative Examples 1-3, and the chips were granulated, then cast, multilayer co-extruded, and bi-stretched. The resulting films were tested according to the standards ASTM D1003, ISO 4287, and ASTM D882. The data are shown in Table 2.

[0166] Table 1 Performance parameters of polyester masterbatch for high-performance release film

[0167]

[0168] Table 2 Performance parameters of MLCC release films prepared from polyester masterbatch

[0169]

[0170] As shown in Tables 1 and 2, compared to Example 2:

[0171] Compared to Example 2, which did not include nano-silica sol, Comparative Example 1 showed poorer crystallization properties in the masterbatch, with larger spherulites, resulting in a film with high haze, poor tensile strength, and low elongation at break.

[0172] Compared to Example 2, Comparative Example 2 did not include submicron hollow mesoporous silicon spheres, and the catalyst was not loaded onto the submicron hollow mesoporous silicon spheres, resulting in a film with poorer opening performance.

[0173] Compared to Example 2, Comparative Example 3 did not have a catalyst loaded on the surface of submicron hollow mesoporous silicon spheres. The catalyst agglomeration was more severe, the content of small molecules in the masterbatch was higher, the prepared film was easy to break, and the tensile strength was poor.

[0174] In summary, the high-performance polyester masterbatch for release film synthesized in Examples 1-3 of this invention has excellent performance, strong crystallization properties, and the film obtained by biaxial stretching has superior optical properties and excellent opening performance.

[0175] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details.

Claims

1. A high-performance polyester masterbatch for release films, characterized in that, It is prepared by esterification and polycondensation of raw materials including terephthalic acid, ethylene glycol, micro-nano opening agents, and stabilizers. The micro / nano opening agent is prepared by the following method: S1. Preparation of submicron hollow mesoporous silicon: Under stirring conditions, deionized water, ethanol, template agent, and ammonia were mixed evenly and stirred. An ethanol solution of silicon source was added dropwise, and the mixture was reacted, centrifuged, washed with water and alcohol, and then added to an acidic ethanol solution. The mixture was heated to reflux and dried to obtain submicron hollow mesoporous silicon. In step S1: The mass ratio of deionized water to ethanol is 9:1 to 1:9; the volume ratio of the sum of the volumes of deionized water and ethanol to that of ammonia is 150:1 to 50:

1. In the ethanol solution of the silicon source, the mass fraction of the silicon source is 10-50%; the amount of silicon source added accounts for 1-20% of the total mass of water and ethanol; the silicon source includes a silicate ester and a silane coupling agent, and the molar ratio of the silicate ester to the silane coupling agent is 9:1-20:1; the silicate ester is tetraethyl orthosilicate, and the silane coupling agent is at least one of bis(3-triethoxysilylpropyl)amine, bis-(γ-trimethoxysilylpropyl)amine, N-phenylaminomethyltriethoxysilane, and γ-mercaptopropyltriethoxysilane; The template agent is a cationic surfactant, and the molar ratio of silicon source to template agent is 10:1 to 60:1; S2. Preparation of nano-silica sol: Add deionized water to an ethylene glycol solution of tetraethyl orthosilicate, then add acidic solution dropwise to adjust the pH to 3-4, heat and stir, add dispersant, continue stirring, raise the temperature, remove water from the system, and obtain nano silica sol; In step S2, the tetraethyl orthosilicate content in the ethylene glycol solution of tetraethyl orthosilicate is 10~50wt%, and the dispersant is at least one of polyethylene glycol 200, polyethylene glycol 400, and polyethylene glycol 600. S3. TiO2 and ZnO were loaded onto submicron hollow mesoporous silica to prepare a mesoporous silica-supported catalyst: The submicron hollow mesoporous silica prepared in step S1 was added to an ethanol solution of Ti source and Zn source. The mixture was heated to 70-90℃ with stirring and refluxed for 2-4 hours. After centrifugation and drying until the Ti source loading was 40-60 wt%, the mixture was placed in a sealed environment and steam was introduced. The pressure of the sealed environment was kept higher than atmospheric pressure. The temperature was raised to 110-130℃ and held for 15-60 minutes. Then the temperature was lowered to room temperature and held for 15-60 minutes. Finally, the mixture was supercritically dried to obtain a mesoporous silica supported catalyst. In step S3, the Ti source is a titanate ester, specifically selected from at least one of tetramethyl titanate, tetraethyl titanate, n-butyl titanate, isopropyl titanate, and tetraisopropyl titanate; the Zn source is Zn(OH)2; the molar ratio of titanate ester to Zn(OH)2 is 1:2 to 1:6; and the mass ratio of the sum of the Ti source and Zn source to the mass of ethanol is 1:20 to 1:

10. S4. The nano-silica sol prepared in step S2 is mixed with the mesoporous silica-supported catalyst prepared in step S3 and ball-milled to prepare a micro / nano opening agent.

2. The high-performance release film polyester masterbatch according to claim 1, characterized in that, Step S1 is as follows: Under stirring conditions at 35-45℃, deionized water, ethanol, template agent, and ammonia water with a mass dispersion of 20-25% are mixed evenly and stirred for 15-60 min. An ethanol solution of silicon source is added dropwise, and the reaction is carried out for 18-30 h. After centrifugation, the mixture is washed with water and alcohol, and then added to an acidic ethanol solution. The mixture is refluxed at 70-90℃ for 8-12 h and dried to obtain submicron hollow mesoporous silicon.

3. The high-performance release film polyester masterbatch according to claim 1, characterized in that, Step S2 is as follows: At 30℃, deionized water was added to an ethylene glycol solution of tetraethyl orthosilicate, and then an acidic solution with a concentration of 0.1~0.8 mol / L was added dropwise to adjust the pH to 3~4. The mixture was heated and stirred, and then stirred at 50~80℃ for 1.5~6 h. After that, a dispersant was added, and stirring was continued for 1~3 h. The temperature was then raised to 110~130℃ to remove water from the system, and nano-silica sol was obtained. The acidic solution is a deionized aqueous solution of at least one of HCl, HNO3, H2SO4, HClO4, HBr, and HI.

4. The high-performance release film polyester masterbatch according to claim 1, characterized in that, The molar ratio of terephthalic acid to ethylene glycol is 1.1:1 to 1.4:1, and the content of micro / nano opening agent in the raw material is 3000 to 10000 ppm.

5. The high-performance release film polyester masterbatch according to claim 1, characterized in that, The stabilizer is one or more of phosphoric acid, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, triphenyl phosphite, phosphorous acid, and polyphosphoric acid. The amount of stabilizer added is controlled according to the P content in the raw material being 10~50 ppm.

6. A method for preparing a high-performance polyester masterbatch for release films as described in any one of claims 1-5, characterized in that, Includes the following steps: Terephthalic acid, ethylene glycol, and micro / nano opening agent are stirred evenly and added to a reaction vessel. After replacing the air with nitrogen, the temperature is raised to 220-245℃ and esterification reaction is carried out under a pressure of 300-350 kPa. The progress of the esterification reaction is measured by the yield of water in the esterification product. When the esterification rate reaches 94%, the esterification is completed. A stabilizer is added to the vessel, and within 1 hour, the pressure in the reaction vessel is gradually reduced from atmospheric pressure to 20-50 Pa using a vacuum pump. The temperature is raised to 270-285℃ to carry out polycondensation chain growth reaction. When the product in the vessel reaches the target viscosity, it is discharged, cooled, and pelletized to obtain high-performance polyester masterbatch for release film.

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