CN117887222A - Special masterbatch for ABA structure MLCC release film base film, preparation method thereof and release film base film - Google Patents

Abstract

The invention discloses a master batch special for an ABA structure MLCC release film base film, a preparation method thereof and the release film base film, wherein the preparation raw materials of the special master batch comprise: modifying the opening agent dispersion slurry, terephthalic acid, ethylene glycol, a catalyst and a heat stabilizer; the modified opening agent dispersion slurry is obtained by adding a modified opening agent into a dispersion solvent and uniformly mixing, and the modified opening agent is prepared by the following method: and mixing the opening agent and the modifying agent, stirring, washing, centrifuging, and drying a solid product to obtain the modified opening agent. The release film base film provided by the invention has the advantages of low roughness, good smoothness, excellent mechanical property and good market application prospect; the modified opening agent added in the master batch can improve the uniform dispersibility of the opening agent particles in the PET matrix by modifying the opening agent particles, can solve the problems of uneven dispersion, poor compatibility with the matrix and precipitation of the opening agent in the master batch, and can improve the comprehensive performance of the prepared release film base film.

Description

Special masterbatch for ABA structure MLCC release film base film, preparation method thereof and release film base film

Technical Field

The present invention relates to the field of release materials, and in particular to a masterbatch dedicated to a MLCC release film base film with an ABA structure, a preparation method thereof, and a release film base film.

Background technique

Multi-layer ceramic capacitors (MLCC) are one of the main passive chip components in electronic equipment. They are called chip capacitors for short. They are made of ceramic dielectric diaphragms with printed electrodes (inner electrodes) stacked in a dislocated manner, and then sintered at high temperature to form ceramic chips. Then, metal layers (outer electrodes) are sealed at both ends of the chip to form a monolithic structure, so they are also called monolithic capacitors. MLCC is one of the world's largest and fastest-growing chip components and is widely used in various electronic products. Among them, the fastest-growing downstream applications include smartphones, automotive electronics, wearable devices, and 5G communication base stations. A large amount of MLCC release film is consumed in the MLCC production process. MLCC usually requires 300 to 1,000 layers of ceramic dielectrics to be stacked. The formation of each layer of ceramic dielectric requires the same release film, and the release film uses polyethylene terephthalate (PET) base film as the base material. High-capacity and miniaturized MLCCs have higher and higher requirements for the number of stacked layers of ceramic materials, and the thickness of their diaphragms is required to be thinner and thinner. Therefore, the main challenge for MLCC matching PET release film is how to achieve low roughness and good smoothness.

At present, most methods for preparing MLCC release films are corona coating methods. For example, patent CN114456428A invented an online preparation method for MLCC release films, which includes the following steps: (1) melt extrusion, cold drum cooling to form PET castings; (2) longitudinally stretching the obtained PET castings; (3) the longitudinally stretched film is first subjected to corona treatment, and then the release agent coating liquid is coated on the corona treated surface of the film through an online coating device. The release agent coating liquid includes the following components according to weight percentage: 20% to 35% release agent emulsion, 3% to 5% curing agent, 1% to 2% catalyst solution, 0.5% to 1% adhesion additive, 0.5% to 2% defoaming agent, 55% to 75% deionized water, and the release agent emulsion includes water-based silicone resin and siloxane polymer; (4) the film coated with the coating liquid is transversely stretched and finally pulled and rolled. The release film coating prepared by the present invention is firmly bonded to the film and evenly distributed, and has a strong tensile strength.

Patent CN116179074A invented a method for preparing MLCC release film by applying a special release emulsion by online coating. The components of the special release emulsion include: 10-50 parts of conductive polymer polythiophene and/or single-arm carbon nanotube aqueous solution; 10-40 parts of modified amino resin; 10-20 parts of nano-silicon dioxide aqueous sol modified by carbamate and acrylate composite; 0.5-5 parts of acid catalyst; 1-5 parts of surfactant; 20-50 parts of water. The release emulsion can be coated on a substrate, especially a PET film, by spraying, roller coating and other coating methods.

Patent CN114407468A invented a MLCC release film with corona coating on an ABA-type structural base film, wherein the A layer is formed by in-situ polymerization of terephthalic acid, isophthalic acid, ethylene glycol, tetrabutyl titanate and silica particles, the B layer PET polyester base material is PET, and the B layer modified polyester masterbatch is polyethylene naphthalate. Then, the surface smoothness is provided by the coating liquid on the A layer nanoparticles and the leveling property of the coating liquid on the online coating surface, and the low roughness is provided by the good dispersion of the in-situ copolymerization of nano-silica on the non-coated surface. However, in general, the masterbatch used in the MLCC base film generally contains anti-adhesion components, such as silicon oxide, barium sulfate, polystyrene, etc., which exist on the surface of the base film in the form of nano- or micron-sized protrusions. However, for MLCC, when the coating is attached to an uneven surface, it will be accompanied by unevenness, resulting in poor peelability and low smoothness. In addition, the MLCC release film can also be obtained by using a masterbatch dedicated to the MLCC release film.

Patent CN110239185B provides a method for preparing a functional masterbatch for MLCC release film. The release film is composed of a three-layer structure of A, B, and C that is formed into an integral whole. Layer A and layer C are surface layers, and layer B is a core layer. Layer A: 0-10% PET, 90%-100% functional masterbatch; layer B: 100% PET; layer C: 0-10% PET, 90%-100% functional masterbatch. The functional masterbatch is composed of 90%-99.5% PET, 0.1%-0.4% nanographite, and 0.1%-9.9% inorganic filler. However, the particle size distribution of the inorganic filler is wide and the particle size is large. The surface roughness Ra of layer A and layer C reaches 17.2μm-17.4μm, which cannot meet the needs of high-end MLCC release films.

Therefore, it is necessary to improve the existing technology to provide a more reliable solution.

Summary of the invention

The technical problem to be solved by the present invention is to provide a special masterbatch for MLCC release film base film with an ABA structure, a preparation method thereof and a release film base film in view of the deficiencies in the above-mentioned prior art.

In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: In the first aspect of the present invention, a masterbatch dedicated to the base film of the MLCC release film with an ABA structure is provided, and the raw materials for preparing the masterbatch include: a modified antiblocking agent dispersion slurry, terephthalic acid, ethylene glycol, a catalyst and a thermal stabilizer;

The modified opening agent dispersion slurry is obtained by adding the modified opening agent to a dispersion solvent and mixing them uniformly. The modified opening agent is prepared by the following method: mixing the opening agent and the modifier, stirring, washing, centrifuging, and drying the solid product to obtain the modified opening agent;

In the preparation raw material, the molar ratio of ethylene glycol to terephthalic acid is 1:1.1-1.6;

The contents of the modified opening agent, catalyst and thermal stabilizer are 2500-10000ppm, 85-340ppm and 150-600ppm respectively.

Preferably, the opening agent is selected from at least one of silicon dioxide (SiO ₂ ), barium sulfate (BaSO ₄ ), and calcium carbonate (CaCO ₃ );

The catalyst is at least one selected from titanium glycolate (Ti(EG) ₂ ), titanium dioxide (TiO ₂ ), antimony glycolate (Sb ₂ (EG) ₃ ), antimony oxide (Sb ₂ O ₃ ), germanium oxide (GeO ₂ ), sodium metaaluminate (NaAlO ₂ ), and sodium aluminosilicate (AlNaO ₆ Si ₂ );

The heat stabilizer is selected from at least one of phosphoric acid, trimethyl phosphate, triphenyl phosphate, and triethyl phosphoacetate.

Preferably, the modifier includes at least one of a coupling agent modifier, a polymer modifier, and an inorganic modifier;

The coupling agent modifier is at least one of dodecyltrimethoxysilane (DTMS), trimethylchlorosilane (TMCS), and γ-methacryloxypropyltrimethoxysilane (KH570); the polymer modifier is at least one of PEG-200, PEG-400, and PEG-800; and the inorganic modifier is at least one of sodium hydroxide (NaOH), potassium hydroxide (KOH), and calcium hydroxide (Ca(OH) ₂ ).

Preferably, the dispersing solvent is at least one of polyethylene glycol, ethylene glycol, butylene glycol, and propylene glycol;

The detergent used for washing during the preparation of the modified opening agent is at least one of N,N-dimethylformamide (DMF), toluene, methanol, ethanol, and deionized water.

Preferably, the opening agent is silicon dioxide, and the modified opening agent is prepared by the following method:

According to the weight percentage, 0.65-2.6% _SiO2 powder, 2.6-10.4% PEG and the rest solvent benzene are mixed, stirred, reacted at 100-120°C for 12-48h under _N2 protection, and then washed with toluene, ethanol and deionized water in turn, centrifuged 2-6 times, and the obtained solid product is vacuum dried at 20-30°C for 12-48h to obtain a modified opening agent;

The modified anti-blocking agent dispersion slurry is prepared by the following method: according to weight percentage, 12.5-50% of modified _SiO2 powder and the remaining amount of ethylene glycol solvent are put into a sand milling tank, and sand milled at 400-1600r/min for 3-12h to obtain the modified anti-blocking agent dispersion slurry.

Preferably, the opening agent is silicon dioxide, and the modified opening agent is prepared by the following method:

_SiO2 powder, NaOH and deionized water are prepared into a slurry with w( _SiO2 )=0.65-2.6%, c(OH ^- )=0.05-0.2mol/L, and etched at 20-40°C for 12-48h, washed with deionized water until neutral and the solution conductivity is ≤50μS/m, and the obtained solid product is vacuum dried at 20-30°C for 12-48h to obtain a modified opening agent;

The modified anti-blocking agent dispersion slurry is prepared by the following method: according to weight percentage, 12.5-50% of modified _SiO2 powder and the remaining amount of ethylene glycol solvent are put into a sand milling tank, and sand milled at 400-1600r/min for 3-12h to obtain the modified anti-blocking agent dispersion slurry.

Preferably, the raw materials for preparing the modified opening agent also include a modifying agent co-agent, and the modifying agent co-agent is at least one of lauric acid, n-hexane, ammonia water, ethanol, methanol, benzene, and toluene.

Preferably, the opening agent is silicon dioxide, and the modified opening agent is prepared by the following method:

According to the weight percentage, 1-4% _SiO2 powder, 0.5-2% KH570 coupling agent, 0.1-0.4% ammonia water and the rest ethanol are mixed, stirred, refluxed at 70-90°C for 6-24h, and then washed with DMF, ethanol and deionized water in turn, centrifuged 2-6 times, and the obtained solid product is vacuum dried at 20-30°C for 12-48h to obtain a modified opening agent;

The modified anti-blocking agent dispersion slurry is prepared by the following method: according to weight percentage, 12.5-50% of modified _SiO2 powder and the remaining amount of ethylene glycol solvent are put into a sand milling tank, and sand milled at 400-1600r/min for 3-12h to obtain the modified anti-blocking agent dispersion slurry.

The second aspect of the present invention provides a method for preparing a masterbatch for a MLCC release film base film with an ABA structure as described above, comprising the following steps:

The terephthalic acid, ethylene glycol, catalyst, heat stabilizer and modified opening agent dispersion are mixed evenly and added into the reactor, and the esterification reaction is carried out at 220-240°C, _N2 atmosphere and 300-330kPa. When the esterification rate reaches more than 95%, the esterification valve is closed; then the temperature is raised to 260-270°C, vacuum is drawn, and a pre-polycondensation reaction is carried out; when the vacuum degree of the system reaches 20-50Pa, the temperature is raised to 270-280°C, and a high vacuum polycondensation is carried out. After the reaction time is 130-170min, the material is discharged, cooled, pelletized and dried to obtain a masterbatch for the base film of the ABA structure MLCC release film.

In a third aspect of the present invention, an ABA structure MLCC release film base film is provided, which is prepared by the following method:

The above-mentioned ABA structure MLCC release film base film dedicated masterbatch and polyester chips are evenly mixed in a mass ratio of 1:3-1:1 as the A layer raw material, and the pure polyester chips are added as the B layer raw material to the corresponding melt extrusion system respectively, and after melting at 270-290°C, ABA three-layer co-extruded is carried out, and after cooling, an ABA three-layer co-extruded structure cast sheet is obtained; the cast sheet is biaxially stretched to obtain an ABA structure MLCC release film base film.

The beneficial effects of the present invention are:

The present invention provides a masterbatch dedicated to an ABA structure MLCC release film base film, a preparation method thereof, and a release film base film based on the masterbatch. The release film base film provided by the present invention has low roughness, good smoothness, and excellent mechanical properties, and has a good market application prospect;

The modified opening agent added to the masterbatch of the present invention can improve its uniform dispersibility in the PET matrix by modifying the opening agent particles, can solve the problems of uneven dispersion of the opening agent in the masterbatch, poor compatibility with the matrix, and precipitation, and can improve the comprehensive performance of the prepared release film base film;

In some preferred embodiments of the present invention, PEG-modified _SiO2 is used as a modified opening agent. By grafting polymers on the surface of SiO2 particles to replace a large number of hydroxyl groups and unsaturated bonds on the surface, the surface energy of the particles is reduced, the disadvantage of easy agglomeration can be overcome, and cross-linking is generated between the grafted polymers and the PET macromolecules, which can improve the dispersibility and compatibility of the nano-silicon dioxide in the PET matrix, which is beneficial to the uniform distribution of particles on the surface of the MLCC film and their stable presence in the PET matrix, achieving the goals of low roughness, excellent smoothness and good opening; the grafted oligomer _SiO2 promotes the crystallization performance of the melt, and increases the entanglement points with the macromolecules, which helps to improve the mechanical properties; the PEG oligomers grafted on the surface of the inorganic particles will interact with the low molecular weight PET matrix, increase the entanglement points with the macromolecules, form a cross-linked network and entanglement structure in the composite material, increase the difficulty of movement of the PET molecular chain, and thus increase the viscosity of PET and improve brittleness.

Detailed ways

The present invention is further described in detail below in conjunction with embodiments so that those skilled in the art can implement the invention with reference to the description.

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

The test methods used in the following examples are conventional methods unless otherwise specified. The materials and reagents used in the following examples are all commercially available unless otherwise specified. In the following examples, if no specific conditions are specified, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used, if the manufacturer is not specified, are all conventional products that can be purchased commercially.

The present invention provides a masterbatch dedicated to a base film of an ABA structure MLCC release film, and the raw materials for preparing the masterbatch include: a modified opening agent dispersion slurry, terephthalic acid, ethylene glycol, a catalyst and a heat stabilizer;

The modified opening agent dispersion slurry is obtained by adding the modified opening agent to a dispersion solvent and mixing them uniformly. The modified opening agent is prepared by the following method: mixing the opening agent and the modifier, stirring, washing, centrifuging, and drying the solid product to obtain the modified opening agent;

In the preparation raw material, the molar ratio of ethylene glycol to terephthalic acid is 1:1.1-1.6. As the alcohol-acid ratio increases, the concentration of free ethylene glycol in the system increases, the esterification rate accelerates, and the side reaction of hydroxyl dehydration condensation of ethylene glycol itself into ether is also accelerated, resulting in an increase in the content of byproduct diethylene glycol in the product, affecting the melting point and color of the product; in addition, too small an alcohol-acid ratio will lead to a decrease in the esterification rate, resulting in low product viscosity and excessive terminal carboxyl content and hydrolysis; so the above ratio is preferred in the present invention.

The contents of the modified opening agent, catalyst and thermal stabilizer are 2500-10000ppm, 85-340ppm and 150-600ppm respectively.

In a preferred embodiment, the opening agent is selected from at least one of silicon dioxide (SiO ₂ ), barium sulfate (BaSO ₄ ), and calcium carbonate (CaCO ₃ );

In a preferred embodiment, the catalyst is selected from at least one of titanium glycolate (Ti(EG) ₂ ), titanium dioxide (TiO ₂ ), antimony glycolate (Sb ₂ (EG) ₃ ), antimony oxide (Sb ₂ O ₃ ), germanium oxide (GeO ₂ ), sodium metaaluminate (NaAlO ₂ ), and sodium aluminosilicate (AlNaO ₆ Si ₂ );

In a preferred embodiment, the heat stabilizer is selected from at least one of phosphoric acid, trimethyl phosphate, triphenyl phosphate, and triethyl phosphoacetate.

In a preferred embodiment, the modifier includes at least one of a coupling agent modifier, a polymer modifier, and an inorganic modifier;

Further preferably, the coupling agent modifier is at least one of dodecyltrimethoxysilane (DTMS), trimethylchlorosilane (TMCS), and γ-methacryloxypropyltrimethoxysilane (KH570); the polymer modifier is at least one of PEG-200, PEG-400, and PEG-800; and the inorganic modifier is at least one of sodium hydroxide (NaOH), potassium hydroxide (KOH), and calcium hydroxide (Ca(OH) ₂ ).

In a preferred embodiment, the dispersion solvent is at least one of polyethylene glycol, ethylene glycol, butylene glycol, and propylene glycol.

In a preferred embodiment, the detergent used for washing during the preparation of the modified opening agent is at least one of N,N-dimethylformamide (DMF), toluene, methanol, ethanol, and deionized water.

In a preferred embodiment, the opening agent is silicon dioxide, and the modified opening agent is prepared by the following method:

According to the weight percentage, 0.65-2.6% _SiO2 powder, 2.6-10.4% PEG and the rest solvent benzene are mixed, stirred, reacted at 100-120°C for 12-48h under _N2 protection, and then washed with toluene, ethanol and deionized water in turn, centrifuged 2-6 times, and the obtained solid product is vacuum dried at 20-30°C for 12-48h to obtain a modified opening agent;

The modified anti-blocking agent dispersion slurry is prepared by the following method: according to weight percentage, 12.5-50% of modified _SiO2 powder and the remaining amount of ethylene glycol solvent are put into a sand milling tank, and sand milled at 400-1600r/min for 3-12h to obtain the modified anti-blocking agent dispersion slurry.

In a preferred embodiment, the opening agent is silicon dioxide, and the modified opening agent is prepared by the following method:

_SiO2 powder, NaOH and deionized water are prepared into a slurry with w( _SiO2 )=0.65-2.6%, c(OH ^- )=0.05-0.2mol/L, and etched at 20-40°C for 12-48h, washed with deionized water until neutral and the solution conductivity is ≤50μS/m, and the obtained solid product is vacuum dried at 20-30°C for 12-48h to obtain a modified opening agent;

The modified anti-blocking agent dispersion slurry is prepared by the following method: according to weight percentage, 12.5-50% of modified _SiO2 powder and the remaining amount of ethylene glycol solvent are put into a sand milling tank, and sand milled at 400-1600r/min for 3-12h to obtain the modified anti-blocking agent dispersion slurry.

In a preferred embodiment, the raw materials for preparing the modified opening agent also include a modifying agent combination agent, and the modifying agent combination agent is at least one of lauric acid, n-hexane, ammonia water, ethanol, methanol, benzene, and toluene.

In a preferred embodiment, the opening agent is silicon dioxide, and the modified opening agent is prepared by the following method:

According to the weight percentage, 1-4% _SiO2 powder, 0.5-2% KH570 coupling agent, 0.1-0.4% ammonia water and the rest ethanol are mixed, stirred, refluxed at 70-90°C for 6-24h, and then washed with DMF, ethanol and deionized water in turn, centrifuged 2-6 times, and the obtained solid product is vacuum dried at 20-30°C for 12-48h to obtain a modified opening agent;

The modified anti-blocking agent dispersion slurry is prepared by the following method: according to weight percentage, 12.5-50% of modified _SiO2 powder and the remaining amount of ethylene glycol solvent are put into a sand milling tank, and sand milled at 400-1600r/min for 3-12h to obtain the modified anti-blocking agent dispersion slurry.

In a preferred embodiment, terephthalic acid is selected from products provided by Hengli Petrochemical Co., Ltd., Zhejiang Yisheng Petrochemical Co., Ltd., Guangzhou Haoyi New Materials Technology Co., Ltd. or Rongsheng Petrochemical Co., Ltd.

In a preferred embodiment, ethylene glycol is selected from products provided by Sinopec Yangzi Petrochemical Co., Ltd., Shanghai Hongzhuang Chemical Technology Co., Ltd., Danhua Chemical Technology Co., Ltd., and Guangzhou Haoyi New Materials Technology Co., Ltd.

The present invention also provides a method for preparing a masterbatch for a base film of an ABA-structured MLCC release film, comprising the following steps:

The terephthalic acid, ethylene glycol, catalyst, heat stabilizer and modified opening agent dispersion are mixed evenly and added into the reactor, and the esterification reaction is carried out at 220-240°C, _N2 atmosphere and 300-330kPa. When the esterification rate reaches more than 95%, the esterification valve is closed; then the temperature is raised to 260-270°C, vacuum is drawn, and a pre-polycondensation reaction is carried out; when the vacuum degree of the system reaches 20-50Pa, the temperature is raised to 270-280°C, and a high vacuum polycondensation is carried out. After the reaction time is 130-170min, the material is discharged, cooled, pelletized and dried to obtain a masterbatch for the base film of the ABA structure MLCC release film.

The present invention also provides an ABA structure MLCC release film base film, which is prepared by the following method:

The above-mentioned ABA structure MLCC release film base film dedicated masterbatch and polyester chips are evenly mixed in a mass ratio of 1:3-1:1 as the A layer raw material, and the pure polyester chips are added as the B layer raw material to the corresponding melt extrusion system respectively, and after melting at 270-290°C, ABA three-layer co-extruded is carried out, and after cooling, an ABA three-layer co-extruded structure cast sheet is obtained; the cast sheet is biaxially stretched to obtain an ABA structure MLCC release film base film.

In a preferred embodiment, the polyester chips are selected from at least one of FG600 base material polyester chips provided by Sinopec Yizheng Chemical Fiber Co., Ltd., CZ-5011 polyester chips provided by Jiangsu Sanfangxiang Group Co., Ltd., and polyester chips provided by Teijin Limited of Japan.

The above is the overall concept of the present invention, and detailed embodiments and comparative examples are provided below on the basis of the overall concept of the present invention to further illustrate the present invention.

In the following examples and comparative examples, the polyester chips were selected from FG600 base polyester chips provided by Sinopec Yizheng Chemical Fiber Co., Ltd., terephthalic acid was purchased from Hengli Petrochemical Co., Ltd., and ethylene glycol was purchased from Sinopec Yangzi Petrochemical Co., Ltd.

Example 1

S1. Preparation of modified anti-blocking agent:

According to the weight percentage, 2% _SiO2 powder, 1% KH570 coupling agent, 0.2% ammonia water and the rest ethanol were mixed in a three-necked flask, and stirred, refluxed at 80°C for 12h, and then washed with DMF, ethanol and deionized water in turn, centrifuged 3 times, and the obtained solid product was vacuum dried at 25°C for 24h to obtain a modified opening agent;

S2. Preparation of modified antiblocking agent dispersion slurry:

According to the weight percentage, 25% of the modified _SiO2 powder and 75% of the ethylene glycol solvent were put into a sand mill, and sand milled at 800 r/min for 6 hours to obtain a modified anti-blocking agent dispersion slurry.

S3. Preparation of special masterbatch:

S3-1. Before feeding, N ₂ was passed to confirm that the esterification reactor and the polycondensation reactor were unobstructed, and then the reactors were preheated to 60°C.

S3-2, terephthalic acid, ethylene glycol, catalyst, heat stabilizer and dispersion slurry are mixed evenly and added into the reactor, the raw material ratio is as follows: the molar ratio of ethylene glycol to terephthalic acid is 1:1.3, the contents of modified opening agent, _{catalyst Sb2O3} and heat stabilizer trimethyl phosphate are 5000ppm, 170ppm and 300ppm respectively;

S3-3, after the feeding is completed, nitrogen is passed to replace the air, and then the reactor is closed and the nitrogen is continued to be passed to pressurize to 120kPa; then the temperature is raised, and the esterification temperature in the kettle is set to 230°C (the actual temperature is between 220 and 240°C), and the stirring power of the agitator is 50Hz, until the pressure is increased to 315kPa, the tower top temperature is increased from room temperature to about 150°C, and the esterification reaction begins to produce water. Since the pressure in the kettle will decrease during the water production process, the needle valve needs to be adjusted to maintain the pressure in the kettle between 300 and 330kPa. After the water output is about 90%, stop adjusting the needle valve;

S3-4. After the water output reaches 95%, the pressure in the kettle is reduced to 120 kPa, the esterification valve is turned off, and the pressure relief valve is opened to make the pressure in the kettle reach atmospheric pressure, and then the temperature is adjusted to 265 ° C, and vacuum is started from normal pressure conditions, and the pressure of the polymerization system is slowly reduced to start the pre-polycondensation reaction; when the vacuum degree of the system reaches 20 Pa, the temperature is raised to 275 ° C, and high vacuum polycondensation is started. After about 150 minutes, the material is discharged, and the gantry pelletizer system is used for cooling, pelletizing and drying to obtain special masterbatch.

S4. Preparation of ABA structure MLCC release film base film:

The special masterbatch and FG600 polyester chips were evenly mixed in a mass ratio of 2:3 as the raw material of layer A, and the pure FG600 polyester chips were added to the corresponding melt extrusion system as the raw material of layer B. After melting at 280°C, ABA three-layer co-extruded was carried out, and the extrusion amount of layer A: layer B: layer A was controlled to be 1:8:1. After cooling on a cold roller at 50°C, an ABA three-layer co-extruded structure cast sheet with a thickness of 450um was obtained; the cast sheet was biaxially stretched 3.0 times to obtain an ABA structure MLCC release film base film with a thickness of 150um.

Example 2

S1. Preparation of modified anti-blocking agent:

According to the weight percentage, 1.3% _SiO2 powder, 5.2% PEG-400 and the rest solvent benzene were mixed in a three-necked flask, and stirred. Under the protection of _N2 , the mixture was reacted at 110°C for 24 hours, and then washed with toluene, ethanol and deionized water in turn, and centrifuged for 3 times. The obtained solid product was vacuum dried at 25°C for 24 hours to obtain a modified opening agent;

S2. Preparation of modified antiblocking agent dispersion slurry:

According to the weight percentage, 25% of the modified _SiO2 powder and 75% of the ethylene glycol solvent were put into a sand mill, and sand milled at 800r/min for 6 hours to obtain a modified anti-blocking agent dispersion slurry.

S3. Preparation of special masterbatch:

S3-1. Before feeding, N ₂ was passed to confirm that the esterification reactor and the polycondensation reactor were unobstructed, and then the reactors were preheated to 60°C.

S3-2, terephthalic acid, ethylene glycol, catalyst, heat stabilizer and dispersion slurry are mixed evenly and added into the reactor, the raw material ratio is as follows: the molar ratio of ethylene glycol to terephthalic acid is 1:1.3, the contents of modified opening agent, _{catalyst Sb2O3} and heat stabilizer trimethyl phosphate are 5000ppm, 170ppm and 300ppm respectively;

S3-3, after the feeding is completed, nitrogen is passed to replace the air, and then the reactor is closed and the nitrogen is continued to be passed to pressurize to 120kPa; then the temperature is raised, and the esterification temperature in the kettle is set to 230°C (the actual temperature is between 220 and 240°C), and the stirring power of the agitator is 50Hz, until the pressure is increased to 315kPa, the tower top temperature is increased from room temperature to about 150°C, and the esterification reaction begins to produce water. Since the pressure in the kettle will decrease during the water production process, the needle valve needs to be adjusted to maintain the pressure in the kettle between 300 and 330kPa. After the water output is about 90%, stop adjusting the needle valve;

S3-4. After the water output reaches 95%, the pressure in the kettle is reduced to 120 kPa, the esterification valve is turned off, and the pressure relief valve is opened to make the pressure in the kettle reach atmospheric pressure, and then the temperature is adjusted to 265 ° C, and vacuum is started from normal pressure conditions, and the pressure of the polymerization system is slowly reduced to start the pre-polycondensation reaction; when the vacuum degree of the system reaches 20 Pa, the temperature is raised to 275 ° C, and high vacuum polycondensation is started. After about 150 minutes, the material is discharged, and the gantry pelletizer system is used for cooling, pelletizing and drying to obtain special masterbatch.

S4. Preparation of ABA structure MLCC release film base film:

The special masterbatch and FG600 polyester chips were evenly mixed in a mass ratio of 2:3 as the raw material of layer A, and the pure FG600 polyester chips were added to the corresponding melt extrusion system as the raw material of layer B. After melting at 280°C, ABA three-layer co-extruded was carried out, and the extrusion amount of layer A: layer B: layer A was controlled to be 1:8:1. After cooling on a cold roller at 50°C, an ABA three-layer co-extruded structure cast sheet with a thickness of 450um was obtained; the cast sheet was biaxially stretched 3.0 times to obtain an ABA structure MLCC release film base film with a thickness of 150um.

Example 3

S1. Preparation of modified anti-blocking agent:

SiO ₂ powder, NaOH and deionized water were prepared into a slurry with w(SiO ₂ )=1.3%, c(OH ^- )=0.1 mol/L, etched at 30°C for 24 hours, washed with deionized water until neutral and the solution conductivity was ≤50μS/m, and the obtained solid product was vacuum dried at 25°C for 24 hours to obtain a modified opening agent;

S2. Preparation of modified antiblocking agent dispersion slurry:

According to the weight percentage, 25% of the modified _SiO2 powder and 75% of the ethylene glycol solvent were put into a sand mill, and sand milled at 800 r/min for 6 hours to obtain a modified anti-blocking agent dispersion slurry.

S3. Preparation of special masterbatch:

S3-1. Before feeding, N ₂ was passed to confirm that the esterification reactor and the polycondensation reactor were unobstructed, and then the reactors were preheated to 60°C.

S3-2, terephthalic acid, ethylene glycol, catalyst, heat stabilizer and dispersion slurry are mixed evenly and added into the reactor, the raw material ratio is as follows: the molar ratio of ethylene glycol to terephthalic acid is 1:1.3, the contents of modified opening agent, _{catalyst Sb2O3} and heat stabilizer trimethyl phosphate are 5000ppm, 170ppm and 300ppm respectively;

S3-3, after the feeding is completed, nitrogen is passed to replace the air, and then the reactor is closed and the nitrogen is continued to be passed to pressurize to 120kPa; then the temperature is raised, and the esterification temperature in the kettle is set to 230°C (the actual temperature is between 220 and 240°C), and the stirring power of the agitator is 50Hz, until the pressure is increased to 315kPa, the tower top temperature is increased from room temperature to about 150°C, and the esterification reaction begins to produce water. Since the pressure in the kettle will decrease during the water production process, the needle valve needs to be adjusted to maintain the pressure in the kettle between 300 and 330kPa. After the water output is about 90%, stop adjusting the needle valve;

S3-4. After the water output reaches 95%, the pressure in the kettle is reduced to 120 kPa, the esterification valve is turned off, and the pressure relief valve is opened to make the pressure in the kettle reach atmospheric pressure, and then the temperature is adjusted to 265 ° C, and vacuum is started from normal pressure conditions, and the pressure of the polymerization system is slowly reduced to start the pre-polycondensation reaction; when the vacuum degree of the system reaches 20 Pa, the temperature is raised to 275 ° C, and high vacuum polycondensation is started. After about 150 minutes, the material is discharged, and the gantry pelletizer system is used for cooling, pelletizing and drying to obtain special masterbatch.

S4. Preparation of ABA structure MLCC release film base film:

The special masterbatch and FG600 polyester chips were evenly mixed in a mass ratio of 2:3 as the raw material of layer A, and the pure FG600 polyester chips were added to the corresponding melt extrusion system as the raw material of layer B. After melting at 280°C, ABA three-layer co-extruded was carried out, and the extrusion amount of layer A: layer B: layer A was controlled to be 1:8:1. After cooling on a cold roller at 50°C, an ABA three-layer co-extruded structure cast sheet with a thickness of 450um was obtained; the cast sheet was biaxially stretched 3.0 times to obtain an ABA structure MLCC release film base film with a thickness of 150um.

Comparative Example 1

S1. Preparation of antiblocking agent dispersion slurry:

According to weight percentage, 25% _SiO2 powder and 75% ethylene glycol solvent were put into a sand mill and sand milled at 800 r/min for 6 hours to obtain an anti-blocking agent dispersion slurry.

S2. Preparation of special masterbatch:

S2-1. Before feeding, N ₂ was passed to confirm that the esterification reactor and the polycondensation reactor were unobstructed, and then the reactors were preheated to 60°C.

S2-2, terephthalic acid, ethylene glycol, catalyst, heat stabilizer, and opening agent dispersion slurry are mixed evenly and added into the reactor, and the raw material ratio satisfies: the molar ratio of ethylene glycol to terephthalic acid is 1:1.3, and the contents of modified opening agent, _{catalyst Sb2O3} and heat stabilizer trimethyl phosphate are 5000ppm, 170ppm and 300ppm respectively;

S2-3, after the feeding is completed, nitrogen is passed to replace the air, and then the reactor is closed and the nitrogen is continued to be passed to pressurize to 120kPa; then the temperature is raised, and the esterification temperature in the kettle is set to 230°C (the actual temperature is between 220 and 240°C), and the stirring power of the agitator is 50Hz, until the pressure is raised to 315kPa, the tower top temperature is raised from room temperature to about 150°C, and the esterification reaction begins to produce water. Since the pressure in the kettle will decrease during the water production process, the needle valve needs to be adjusted to maintain the pressure in the kettle between 300 and 330kPa. After the water output is about 90%, stop adjusting the needle valve;

S2-4. After the water output reaches 95%, the pressure in the kettle is reduced to 120 kPa, the esterification valve is turned off, and the pressure relief valve is opened to make the pressure in the kettle reach atmospheric pressure, and then the temperature is adjusted to 265 ° C, and vacuum is started from normal pressure conditions, and the pressure of the polymerization system is slowly reduced to start the pre-polycondensation reaction; when the vacuum degree of the system reaches 20 Pa, the temperature is raised to 275 ° C, and high vacuum polycondensation is started. After about 150 minutes, the material is discharged, and the gantry pelletizer system is used for cooling, pelletizing and drying to obtain special masterbatch.

S3. Preparation of ABA structure MLCC release film base film:

The special masterbatch and FG600 polyester chips were evenly mixed in a mass ratio of 2:3 as the raw material of layer A, and the pure FG600 polyester chips were added to the corresponding melt extrusion system as the raw material of layer B. After melting at 280°C, ABA three-layer co-extruded was carried out, and the extrusion amount of layer A: layer B: layer A was controlled to be 1:8:1. After cooling on a cold roller at 50°C, an ABA three-layer co-extruded structure cast sheet with a thickness of 450um was obtained; the cast sheet was biaxially stretched 3.0 times to obtain an ABA structure MLCC release film base film with a thickness of 150um.

The special masterbatch and ABA structure MLCC release film base film prepared in Examples 1-3 and Comparative Example 1 were subjected to relevant performance tests, and the test results are shown in Table 1 below:

Table 1

In the table:

Melting point and crystallinity test: using Mettler-Toledo differential scanning calorimeter, model: DSC 3;

Ash content: tested according to the method of standard GB/T 14190-2017;

Surface roughness: Use Olympus polarizing microscope, model: BX51TRF;

Colorimetry: Use PerkinElmer spectrophotometer, model: Lambda 950;

Transmittance and haze test: Use the haze transmittance meter from Triumph, model: YS6002-M;

Tensile strength and elongation at break: tested according to the method of standard GB/T 1040-2018.

According to the test results in Table 1, the intrinsic viscosity of the MLCC masterbatch according to Example 2 is increased to 0.652dL/g, the crystallinity is 11.91%, and the ash content of the masterbatch after randomly taking three groups of mixed uniformly is 0.520, 0.537, and 0.531, respectively, indicating that the opening agent particles are evenly distributed in the masterbatch. Further, in Example 2, the crystallinity of the MLCC film is increased to 33.95%, and then the tensile strength in the MD and TD directions is increased to 251.66MPa and 247.79MPa, respectively, and the elongation at break in the MD and TD directions is increased to 178.90% and 171.17%, respectively, indicating that the modified SiO particles can promote crystallization and are well integrated into the PET matrix, without large-area accumulation to cause film breakage; the surface roughness Ra and Rz are reduced to 0.014 and 0.185, respectively, the corresponding chromaticity value b is 0.184, the optical transmittance is 89.21, and the haze is 3.87. Good dispersion and fusion reduce the roughness and haze, and maintain the opening characteristics.

In Example 2, polymers are grafted onto the surface of SiO particles to replace a large number of hydroxyl groups and unsaturated bonds on the surface, thereby reducing the surface energy of the SiO particles and overcoming the disadvantage of easy agglomeration. Crosslinking occurs between the grafted polymer and the PET macromolecules, which can improve the dispersibility and compatibility of the nano-silicon dioxide in the PET matrix, and is beneficial to the uniform distribution of particles on the surface of the MLCC film and their stable presence in the PET matrix, achieving the goals of low roughness, excellent smoothness, and good opening. The _SiO2 grafted oligomer promotes the crystallization properties of the melt and increases the entanglement points with the macromolecules, which helps to improve the mechanical properties.

The products of Example 1 and Example 3 also achieved good comprehensive performance and were significantly better than Comparative Example 1.

Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to specific details.

Claims (10)

1. A masterbatch for ABA structure MLCC release film base film, characterized in that the raw materials for its preparation include: modified opening agent dispersion slurry, terephthalic acid, ethylene glycol, a catalyst and a thermal stabilizer; The modified opening agent dispersion slurry is obtained by adding the modified opening agent to a dispersion solvent and mixing them uniformly. The modified opening agent is prepared by the following method: mixing the opening agent and the modifier, stirring, washing, centrifuging, and drying the solid product to obtain the modified opening agent; In the preparation raw material, the molar ratio of ethylene glycol to terephthalic acid is 1:1.1-1.6, and the contents of the modified opening agent, the catalyst and the heat stabilizer are 2500-10000ppm, 85-340ppm and 150-600ppm respectively. 2. The ABA structure MLCC release film base film dedicated masterbatch according to claim 1, characterized in that the opening agent is selected from at least one of silicon dioxide, barium sulfate and calcium carbonate; The catalyst is selected from at least one of titanium glycolate, titanium dioxide, antimony glycolate, antimony oxide, germanium oxide, sodium metaaluminate, and sodium aluminosilicate; The heat stabilizer is selected from at least one of phosphoric acid, trimethyl phosphate, triphenyl phosphate, and triethyl phosphoacetate. 3. The ABA structure MLCC release film base film dedicated masterbatch according to claim 2, characterized in that the modifier includes at least one of a coupling agent modifier, a polymer modifier, and an inorganic modifier; The coupling agent modifier is at least one of dodecyltrimethoxysilane, trimethylchlorosilane, and γ-methacryloxypropyltrimethoxysilane; the polymer modifier is at least one of PEG-200, PEG-400, and PEG-800; and the inorganic modifier is at least one of sodium hydroxide, potassium hydroxide, and calcium hydroxide. 4. The ABA structure MLCC release film base film dedicated masterbatch according to claim 1, characterized in that the dispersion solvent is at least one of polyethylene glycol, ethylene glycol, butanediol, and propylene glycol; The detergent used for washing during the preparation of the modified opening agent is at least one of N,N-dimethylformamide, toluene, methanol, ethanol and deionized water. 5. The ABA structure MLCC release film base film dedicated masterbatch according to claim 3, characterized in that the opening agent is silicon dioxide, and the modified opening agent is prepared by the following method: According to the weight percentage, 0.65-2.6% _SiO2 powder, 2.6-10.4% PEG and the rest solvent benzene are mixed, stirred, reacted at 100-120°C for 12-48h under _N2 protection, and then washed with toluene, ethanol and deionized water in turn, centrifuged 2-6 times, and the obtained solid product is vacuum dried at 20-30°C for 12-48h to obtain a modified opening agent; The modified anti-blocking agent dispersion slurry is prepared by the following method: according to weight percentage, 12.5-50% of modified _SiO2 powder and the remaining amount of ethylene glycol solvent are put into a sand milling tank, and sand milled at 400-1600r/min for 3-12h to obtain the modified anti-blocking agent dispersion slurry. 6. The ABA structure MLCC release film base film dedicated masterbatch according to claim 3, characterized in that the opening agent is silicon dioxide, and the modified opening agent is prepared by the following method: _SiO2 powder, NaOH and deionized water are prepared into a slurry with w( _SiO2 )=0.65-2.6%, c(OH ^- )=0.05-0.2mol/L, and etched at 20-40°C for 12-48h, washed with deionized water until neutral and the solution conductivity is ≤50μS/m, and the obtained solid product is vacuum dried at 20-30°C for 12-48h to obtain a modified opening agent; The modified anti-blocking agent dispersion slurry is prepared by the following method: according to weight percentage, 12.5-50% of modified _SiO2 powder and the remaining amount of ethylene glycol solvent are put into a sand milling tank, and sand milled at 400-1600r/min for 3-12h to obtain the modified anti-blocking agent dispersion slurry. 7. The ABA structure MLCC release film base film dedicated masterbatch according to claim 3 is characterized in that the preparation raw materials of the modified opening agent also include a modifier coupling agent, and the modifier coupling agent is at least one of lauric acid, n-hexane, ammonia water, ethanol, methanol, benzene, and toluene. 8. The ABA structure MLCC release film base film dedicated masterbatch according to claim 7, characterized in that the opening agent is silicon dioxide, and the modified opening agent is prepared by the following method: According to the weight percentage, 1-4% _SiO2 powder, 0.5-2% KH570 coupling agent, 0.1-0.4% ammonia water and the rest ethanol are mixed, stirred, refluxed at 70-90°C for 6-24h, and then washed with DMF, ethanol and deionized water in turn, centrifuged 2-6 times, and the obtained solid product is vacuum dried at 20-30°C for 12-48h to obtain a modified opening agent; The modified anti-blocking agent dispersion slurry is prepared by the following method: according to weight percentage, 12.5-50% of modified _SiO2 powder and the remaining amount of ethylene glycol solvent are put into a sand milling tank, and sand milled at 400-1600r/min for 3-12h to obtain the modified anti-blocking agent dispersion slurry. 9. A method for preparing a masterbatch for a base film of an ABA structured MLCC release film as claimed in any one of claims 1 to 8, characterized in that it comprises the following steps: The terephthalic acid, ethylene glycol, catalyst, heat stabilizer and modified opening agent dispersion are mixed evenly and added into the reactor, and the esterification reaction is carried out at 220-240°C, _N2 atmosphere and 300-330kPa. When the esterification rate reaches more than 95%, the esterification valve is closed; then the temperature is raised to 260-270°C, vacuum is drawn, and a pre-polycondensation reaction is carried out; when the vacuum degree of the system reaches 20-50Pa, the temperature is raised to 270-280°C, and a high vacuum polycondensation is carried out. After the reaction time is 130-170min, the material is discharged, cooled, pelletized and dried to obtain a masterbatch for the base film of the ABA structure MLCC release film. 10. An ABA structure MLCC release film base film, characterized in that it is prepared by the following method: The ABA structure MLCC release film base film dedicated masterbatch according to any one of claims 1 to 8 and polyester chips are evenly mixed in a mass ratio of 1:3-1:1 as the A layer raw material, and the pure polyester chips are added as the B layer raw material to the corresponding melt extrusion system respectively, and after melting at 270-290°C, ABA three-layer co-extruded is carried out, and after cooling, an ABA three-layer co-extruded structure cast sheet is obtained; the cast sheet is biaxially stretched to obtain an ABA structure MLCC release film base film.