MLCC release film base film and preparation method thereof

Abstract

The invention discloses an MLCC release film base film and a preparation method thereof, and relates to the technical field of release films, the MLCC release film base film comprises a core layer and a functional coating layer arranged on the outer surface of the core layer; the core layer is prepared from the following raw materials: PET (Polyethylene Terephthalate) resin, functional polyester containing triazolyl tetrafluorophenyl, a coupling agent, reinforced fibers, an antioxidant and a lubricant; the functional coating layer is prepared from the following components: hydroxyl-terminated hyperbranched polyester, isocyano ethyl methacrylate, vinyl trimethoxy silane, nano filler, 3, 3 '-diamino-4, 4'-difluorodiphenyl sulfone, 2, 2 '-bis (trifluoromethyl) diaminobiphenyl, a photoinitiator, a catalyst A and a diluent. The base film is low in surface roughness and warping degree, good in high temperature resistance, high in flatness and appropriate in stiffness.

Description

Technical Field

[0001] The present invention relates to the technical field of release films, and in particular to an MLCC release film base film and a preparation method thereof. Background Art

[0002] MLCC (chip multilayer ceramic capacitor) is known as the "rice of the electronics industry". It is one of the world's most widely used and fastest-growing chip components and is widely used in various electronic products. The fastest-growing downstream applications include smartphones, automotive electronics, wearable devices, and 5G communication base stations. In the manufacturing process of MLCC, the indispensable core material is the release film. As a high-consumption auxiliary material in the manufacturing process of MLCC, the MLCC release film changes in conjunction with the production quantity of MLCC, and the market is showing a clear expansion trend.

[0003] MLCC release film is composed of a release layer and a base film. As the base material of the release film, the base film directly affects the formability of the release layer and is one of the key materials of the release film. At present, the base film of MLCC release film often uses polyester as the main raw material, and is cast by extrusion, and then made into a polyester film by longitudinal and transverse biaxial stretching. However, the existing ordinary polyester base film has poor high temperature resistance and flatness stability, the surface release agent adhesion rate needs to be further improved, the roughness needs to be further reduced, and the release film using this type of base film has to be further improved in terms of peelability and smoothness.

[0004] In order to solve the above problems, the Chinese invention patent with the authorization announcement number CN113334809B discloses a production process of a release film base film for MLCC, including the following steps: S1: preparing a base film casting sheet with a surface layer, a core layer and a surface structure; S2: preheating, heating and longitudinally stretching and cooling the base film casting sheet; S3: coating a coating liquid on one surface of the base film casting sheet; S4: the casting sheet with an uncured coating liquid coating is sequentially preheated, heated and transversely stretched, and the coating is cured, heat-set, annealed and cooled to obtain a base film; annealing includes a first annealing section and a second annealing section in sequence, and the temperature of the first annealing section is lower than the temperature of the second annealing section. The invention reduces the internal stress of the base film material through the process of the first annealing section and the second annealing section, achieves better temperature resistance, and then improves the stability of the flatness of the base film. The invention also discloses a base film for a release film for MLCC. However, the surface roughness and warpage of the base film of the release film for MLCC need to be further reduced, and the stiffness needs to be further improved.

[0005] It can be seen that the development of an MLCC release film base film with low surface roughness and warping, good high temperature resistance, high flatness and appropriate stiffness and its preparation method meets the market demand, has broad market value and application prospects, and is of great significance to promoting the development of the MLCC release film field. Summary of the invention

[0006] The object of the present invention is to provide an MLCC release film base film with low surface roughness and warpage, excellent high-temperature resistance, high flatness, and appropriate stiffness, and a preparation method thereof, in order to overcome the deficiencies of the prior art.

[0007] To achieve the above object, the technical solution adopted by the present invention is: an MLCC release film base film, comprising a core layer and a functional coating layer provided on the outer surface of the core layer; the core layer is made of the following raw materials by weight: 100 parts of PET resin, 15 - 25 parts of a functional polyester containing a triazolyl tetrafluorophenyl group, 3 - 5 parts of a coupling agent, 5 - 8 parts of reinforcing fiber, 1 - 2 parts of an antioxidant, 0.8 - 1.2 parts of a lubricant; the functional polyester containing a triazolyl tetrafluorophenyl group includes structural units introduced by the following monomers: N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluoroterephthalyl alcohol; the functional coating layer is made of the following components by weight: 20 - 30 parts of a hydroxyl-terminated hyperbranched polyester, 8 - 10 parts of isocyanatoethyl methacrylate, 1 - 3 parts of vinyltrimethoxysilane, 3 - 5 parts of a nano filler, 1 - 2 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone, 1 - 3 parts of 2,2'-bis(trifluoromethyl)diaminobiphenyl, 0.5 - 0.8 parts of a photoinitiator, 0.3 - 0.6 parts of a catalyst A, 15 - 25 parts of a diluent.

[0008] Preferably, the PET resin has the brand of PET CZ-333 and is provided by Jiangyin Xingye.

[0009] Preferably, the preparation method of the functional polyester containing a triazolyl tetrafluorophenyl group comprises the following steps: adding N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluoroterephthalyl alcohol, and a catalyst B into a high-boiling solvent, stirring at 115 - 130 °C for 1 - 3 hours to obtain a reaction solution, then adding the reaction solution into a high-pressure reaction kettle, closing the feeding port after the feeding is completed, purging the air in the reaction kettle with an inert gas, then stirring and reacting at 130 - 150 °C under normal pressure for 3 - 5 hours, then reducing the pressure to 10 - 60 Pa, raising the temperature to 250 - 270 °C, and carrying out a heat-insulating and pressure-holding stirring reaction for 8 - 13 hours. After the reaction is completed, it is cooled to room temperature, precipitated in water, and then the precipitated polymer is washed with ethanol 3 - 6 times, and finally dried in a vacuum dryer at 85 - 95 °C to constant weight to obtain the functional polyester containing a triazolyl tetrafluorophenyl group.

[0010] Preferably, the molar ratio of N-(4H-1,2,4-triazol-4-yl) diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluoroterephthalyl alcohol, catalyst B, and high-boiling solvent is 1:1:(0.8 - 1.2):(10 - 15); the high-boiling solvent is dimethyl sulfoxide; catalyst B is a mixture formed by mixing antimony glycolate, tetrabutyl titanate, and p-toluenesulfonic acid in a molar ratio of 1:(0.8 - 1.2):(0.3 - 0.6); the inert gas is any one of nitrogen, helium, neon, and argon.

[0011] Preferably, the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570; the reinforcing fiber is at least one of nano boron fiber and carbon nanofiber; the average diameter of the reinforcing fiber is 10 - 100 nm, and the average aspect ratio is (25 - 40):1.

[0012] Preferably, the antioxidant is at least one of antioxidant 1010 and antioxidant 168; the lubricant is at least one of pentaerythritol stearate and ethylene bisstearamide.

[0013] Preferably, the hydroxyl-terminated hyperbranched polyester is hydroxyl-terminated hyperbranched polyester Hyper H203, provided by Wuhan Hyperbranched Resin Technology Co., Ltd.

[0014] Preferably, the nano filler is at least one of nano silica and nano calcium carbonate; the particle size of the nano filler is 20 - 80 nm.

[0015] Preferably, the photoinitiator is benzoin ethyl ether; catalyst A is at least one of dibutyltin dilaurate DY-12 and organobismuth DY-20.

[0016] Preferably, the diluent is a mixture of methyl methacrylate, butyl methacrylate, and hydroxypropyl methacrylate in a mass ratio of 1:(1 - 2):(0.8 - 1.2).

[0017] Another object of the present invention is to provide a method for preparing the MLCC release film base film, comprising the following steps:

[0018] Step S1: Mix the raw materials for the core layer evenly by weight to obtain a mixed material, then successively perform melt extrusion, casting, and calendaring to form a sheet; then perform biaxial stretching to obtain the core layer film material;

[0019] Step S2: Mix the components of the functional coating layer evenly, perform vacuum degassing, then coat on the outer surface of the core layer, and after curing and drying, obtain the MLCC release film base film.

[0020] Preferably, the temperature for melt extrusion in step S1 is 240 - 260 °C; the temperature for casting is 260 - 280 °C; the temperature of the casting roller for sheet casting is 25 - 30 °C.

[0021] Preferably, the stretching temperature for biaxial stretching in step S1 is 110 - 120 °C, the stretching rate is 90 - 120 mm / s, the heat setting temperature is 230 - 250 °C, and the stretching ratio is 3 - 5.

[0022] Preferably, the coating method in step S2 is micro gravure coating.

[0023] Preferably, the curing is carried out under ultraviolet light with a wavelength of 220 - 250 nm for 25 - 35 min; the drying is carried out at 80 - 90 °C for 3 - 5 min.

[0024] Preferably, the thickness of the core layer is 20 - 25 μm, and the thickness of the functional coating layer is 100 nm.

[0025] Due to the application of the above technical solutions, the present invention has the following beneficial effects:

[0026] (1) The preparation method of the MLCC release film base film disclosed by the present invention does not require special equipment, has low capital investment, a simple process flow, easy control of production conditions, strong operability, low energy consumption, is suitable for large-scale production, and has high popularization and application value.

[0027] (2) The base film of the MLCC release film disclosed by the present invention includes a core layer and a functional coating layer provided on the outer surface of the core layer; the core layer is made of the following raw materials by weight: 100 parts of PET resin, 15 - 25 parts of a functional polyester containing a triazolyl tetrafluorophenyl group, 3 - 5 parts of a coupling agent, 5 - 8 parts of reinforcing fibers, 1 - 2 parts of an antioxidant, 0.8 - 1.2 parts of a lubricant; the functional coating layer is made of the following components by weight: 20 - 30 parts of a hydroxyl - terminated hyperbranched polyester, 8 - 10 parts of isocyanatoethyl methacrylate, 1 - 3 parts of vinyltrimethoxysilane, 3 - 5 parts of nano - fillers, 1 - 2 parts of 3,3'-diamino - 4,4'-difluorodiphenyl sulfone, 1 - 3 parts of 2,2'-bis(trifluoromethyl)benzidine, 0.5 - 0.8 parts of a photoinitiator, 0.3 - 0.6 parts of catalyst A, 15 - 25 parts of a diluent. Through the design of the above - mentioned structure, the flatness and stability of the base film can be effectively improved; through the reasonable selection of the raw materials and components of the functional coating layer and the core layer, the compatibility between the two layers is good, and delamination is not likely to occur; the various raw materials and components cooperate with each other and act together, making the surface roughness and warpage of the manufactured product low, with good high - temperature resistance, high flatness, and appropriate stiffness; the functional polyester containing a triazolyl tetrafluorophenyl group includes structural units introduced by the following monomers: N-(4H - 1,2,4 - triazol - 4 - yl)diphenylamine - 4,4'-dicarboxylic acid, 2,3,5,6 - tetrafluoroterephthalyl alcohol; by introducing a triazolyl group, a tetrafluorophenyl group, and an ester group into the molecular structure simultaneously, under the multiple effects of electronic effects, steric effects, and conjugation effects, etc., the comprehensive performance and performance stability of the base film can be further improved, thereby effectively improving the service life and shelf life of the base film; and this functional polyester and PET both belong to polyester materials, with good compatibility and not likely to have phase separation.

[0028] (3) For the base film of the MLCC release film disclosed by the present invention, the setting of the functional coating layer can further improve the surface flatness of the base film and reduce its roughness, and the nano - fillers therein can fill the unevenness or slopes on the surface of the core layer; the introduction of rigid structures such as fluorinated diphenyl sulfone and fluorinated biphenyl can further improve the high - temperature resistance under the multiple effects of electronic effects, steric effects, and conjugation effects, etc., and cooperate with other components and raw materials to effectively reduce the warpage, making the stiffness of the base film more appropriate.

[0029] (4) For the base film of the MLCC release film disclosed by the present invention, through the reasonable selection of the preparation process parameters, the surface roughness and warpage of the manufactured base film are lower, the high - temperature resistance is better, the flatness is higher, and the stiffness is more appropriate. Detailed implementation manners

[0030] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations.

[0031] Example 1: An MLCC release film base film, comprising a core layer and a functional coating layer provided on the outer surface of the core layer; the core layer is made of the following raw materials by weight: 100 parts of PET resin, 15 parts of a functional polyester containing triazolyl tetrafluorophenyl, 3 parts of a coupling agent, 5 parts of reinforcing fiber, 1 part of antioxidant, 0.8 part of lubricant; the functional polyester containing triazolyl tetrafluorophenyl includes structural units introduced by the following monomers: N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluoroterephthalyl alcohol; the functional coating layer is made of the following components by weight: 20 parts of a hydroxyl-terminated hyperbranched polyester, 8 parts of isocyanatoethyl methacrylate, 1 part of vinyltrimethoxysilane, 3 parts of nano filler, 1 part of 3,3'-diamino-4,4'-difluorodiphenylsulfone, 1 part of 2,2'-bis(trifluoromethyl)diaminobiphenyl, 0.5 part of photoinitiator, 0.3 part of catalyst A, 15 parts of diluent.

[0032] The PET resin has the trade name PET CZ-333 and is provided by Jiangyin Xingye.

[0033] The preparation method of the functional polyester containing triazolyl tetrafluorophenyl includes the following steps: adding N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluoroterephthalyl alcohol, and catalyst B into a high-boiling solvent, stirring at 115 °C for 1 hour to obtain a reaction solution, then adding the reaction solution into a high-pressure reaction kettle, closing the feeding port after feeding, purging the air in the reaction kettle with an inert gas, then stirring and reacting at 130 °C under normal pressure for 3 hours, then reducing the pressure to 10 Pa, raising the temperature to 250 °C, maintaining the temperature and pressure and stirring and reacting for 8 hours, cooling to room temperature after the reaction, precipitating in water, then washing the precipitated polymer with ethanol 3 times, and finally drying in a vacuum dryer at 85 °C to constant weight to obtain the functional polyester containing triazolyl tetrafluorophenyl; the molar ratio of N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluoroterephthalyl alcohol, catalyst B, and high-boiling solvent is 1:1:0.8:10; the high-boiling solvent is dimethyl sulfoxide; the catalyst B is a mixture formed by mixing ethylene glycol antimonate, tetrabutyl titanate, and p-toluenesulfonic acid in a molar ratio of 1:0.8:0.3; the inert gas is nitrogen. Through GPC testing, the M of the obtained functional polyester containing triazolyl tetrafluorophenyl was measured. n = 16820 g / mol, M W / M n= 1.348; Through elemental analysis and calculation, the molar ratio of the structural units introduced by N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid and 2,3,5,6-tetrafluoroterephthalyl alcohol in the functional polyester containing triazolyl tetrafluorophenyl is the same as the theoretical value.

[0034] The coupling agent is silane coupling agent KH550; the reinforcing fiber is nano boron fiber; the average diameter of the reinforcing fiber is 10 nm, and the average aspect ratio is 25:1; the antioxidant is antioxidant 1010; the lubricant is pentaerythritol stearate; the hyperbranched polyester with terminal hydroxyl groups is hyperbranched polyester Hyper H203 provided by Wuhan Hyperbranched Resin Technology Co., Ltd.; the nano filler is nano silica; the particle size of the nano filler is 20 nm; the photoinitiator is benzoin ethyl ether; the catalyst A is dibutyltin dilaurate DY-12; the diluent is a mixture of methyl methacrylate, butyl methacrylate, and hydroxypropyl methacrylate in a mass ratio of 1:1:0.8.

[0035] A preparation method of the MLCC release film base film includes the following steps:

[0036] Step S1: After mixing the raw materials for the core layer evenly by weight, a mixed material is obtained, and then through melt extrusion, casting, and sheet casting in sequence to form a sheet; then it is biaxially stretched to obtain the core layer film material;

[0037] Step S2: Mix the components of the functional coating layer evenly, remove bubbles under vacuum, coat them on the outer surface of the core layer, and after curing and drying, obtain the MLCC release film base film.

[0038] In step S1, the temperature of the melt extrusion is 240 °C; the temperature of the casting is 260 °C; the temperature of the casting roller for sheet casting is 25 °C; in step S1, the stretching temperature for the biaxial stretching is 110 °C, the stretching rate is 90 mm / s, the heat setting temperature is 230 °C, and the stretching ratio is 4.

[0039] In step S2, the coating method is micro gravure coating; the curing is carried out under ultraviolet light with a wavelength of 220 nm for 25 min; the drying is carried out at 80 °C for 3 min; the thickness of the core layer is 25 μm, and the thickness of the functional coating layer is 100 nm.

[0040] Example 2: An MLCC release film base film, comprising a core layer and a functional coating layer provided on the outer surface of the core layer; the core layer is made of the following raw materials by weight: 100 parts of PET resin, 17 parts of a functional polyester containing a triazolyl tetrafluorophenyl group, 3.5 parts of a coupling agent, 6 parts of reinforcing fiber, 1.2 parts of an antioxidant, and 0.9 part of a lubricant; the functional polyester containing a triazolyl tetrafluorophenyl group includes structural units introduced by the following monomers: N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluoroterephthalyl alcohol; the functional coating layer is made of the following components by weight: 23 parts of a hydroxyl-terminated hyperbranched polyester, 8.5 parts of isocyanatoethyl methacrylate, 1.5 parts of vinyltrimethoxysilane, 3.5 parts of nano-fillers, 1.2 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone, 1.5 parts of 2,2'-bis(trifluoromethyl)diaminobiphenyl, 0.6 part of a photoinitiator, 0.4 part of catalyst A, and 17 parts of a diluent.

[0041] The PET resin has the brand name PET CZ-333 and is provided by Jiangyin Xingye.

[0042] The preparation method of the functional polyester containing a triazolyl tetrafluorophenyl group comprises the following steps: adding N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluoroterephthalyl alcohol, and catalyst B into a high-boiling solvent, stirring at 120 °C for 1.5 hours to obtain a reaction solution, then adding the reaction solution into a high-pressure reaction kettle, closing the feeding port after the feeding is completed, purging the air in the reaction kettle with an inert gas, then stirring and reacting at 135 °C under normal pressure for 3.5 hours, then reducing the pressure to 20 Pa, raising the temperature to 255 °C, and stirring and reacting under constant temperature and pressure for 9 hours. After the reaction is completed, it is cooled to room temperature, precipitated in water, and the precipitated polymer is washed 4 times with ethanol, and finally dried to constant weight at 87 °C in a vacuum dryer to obtain the functional polyester containing a triazolyl tetrafluorophenyl group; the molar ratio of N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluoroterephthalyl alcohol, catalyst B, and high-boiling solvent is 1:1:0.9:11; the high-boiling solvent is dimethyl sulfoxide; the catalyst B is a mixture formed by mixing ethylene glycol antimonate, tetrabutyl titanate, and p-toluenesulfonic acid in a molar ratio of 1:0.9:0.4; the inert gas is helium.

[0043] The coupling agent is silane coupling agent KH560; the reinforcing fiber is carbon nanofiber; the average diameter of the reinforcing fiber is 30 nm, and the average aspect ratio is 30:1; the antioxidant is antioxidant 168; the lubricant is ethylene bisstearamide; the hydroxyl-terminated hyperbranched polyester is hydroxyl-terminated hyperbranched polyester Hyper H203, provided by Wuhan Hyperbranched Resin Technology Co., Ltd.; the nano filler is nano calcium carbonate; the particle size of the nano filler is 40 nm; the photoinitiator is benzoin ethyl ether; the catalyst A is organic bismuth DY-20; the diluent is a mixture of methyl methacrylate, butyl methacrylate, and hydroxypropyl methacrylate in a mass ratio of 1:1.2:0.9.

[0044] A method for preparing the base film of the MLCC release film includes the following steps:

[0045] Step S1: After uniformly mixing the raw materials for preparing the core layer by weight, a mixed material is obtained, and then it is successively subjected to melt extrusion, casting, and calendaring to form a sheet; and then a core layer film material is obtained through biaxial stretching.

[0046] Step S2: The components of the functional coating layer are uniformly mixed, degassed under vacuum, coated on the outer surface of the core layer, and after curing and drying, the base film of the MLCC release film is obtained.

[0047] In step S1, the temperature of the melt extrusion is 245 °C; the temperature of the casting is 265 °C; the temperature of the calendaring roll for calendaring is 27 °C; in step S1, the stretching temperature for biaxial stretching is 113 °C, the stretching rate is 100 mm / s, the heat setting temperature is 235 °C, and the stretching ratio is 4.

[0048] In step S2, the coating method is micro gravure coating; the curing is carried out under ultraviolet light with a wavelength of 230 nm for 27 min; the drying is carried out at 83 °C for 3.5 min; the thickness of the core layer is 25 μm, and the thickness of the functional coating layer is 100 nm.

[0049] Example 3: An MLCC release film base film, comprising a core layer and a functional coating layer provided on the outer surface of the core layer; the core layer is made of the following raw materials by weight: 100 parts of PET resin, 20 parts of a functional polyester containing triazolyl tetrafluorophenyl, 4 parts of a coupling agent, 6.5 parts of reinforcing fiber, 1.5 parts of antioxidant, and 1 part of lubricant; the functional polyester containing triazolyl tetrafluorophenyl includes structural units introduced by the following monomers: N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluoroterephthalyl alcohol; the functional coating layer is made of the following components by weight: 25 parts of a hydroxyl-terminated hyperbranched polyester, 9 parts of isocyanatoethyl methacrylate, 2 parts of vinyltrimethoxysilane, 4 parts of nano filler, 1.5 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone, 2 parts of 2,2'-bis(trifluoromethyl)diaminobiphenyl, 0.65 part of photoinitiator, 0.45 part of catalyst A, and 20 parts of diluent.

[0050] The PET resin has the brand name PET CZ-333 and is provided by Jiangyin Xingye.

[0051] The preparation method of the functional polyester containing triazolyl tetrafluorophenyl includes the following steps: adding N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluoroterephthalyl alcohol, and catalyst B into a high-boiling solvent, stirring at 123 °C for 2 hours to obtain a reaction solution, then adding the reaction solution into a high-pressure reaction kettle, closing the feeding port after feeding, purging the air in the reaction kettle with an inert gas, then stirring and reacting at 140 °C under normal pressure for 4 hours, then reducing the pressure to 40 Pa, raising the temperature to 260 °C, maintaining the temperature and pressure and stirring and reacting for 11 hours, cooling to room temperature after the reaction, precipitating in water, then washing the precipitated polymer with ethanol 5 times, and finally drying in a vacuum dryer at 90 °C to constant weight to obtain the functional polyester containing triazolyl tetrafluorophenyl; the molar ratio of N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluoroterephthalyl alcohol, catalyst B, and high-boiling solvent is 1:1:1:13; the high-boiling solvent is dimethyl sulfoxide; the catalyst B is a mixture formed by mixing ethylene glycol antimonate, tetrabutyl titanate, and p-toluenesulfonic acid in a molar ratio of 1:1:0.45; the inert gas is neon.

[0052] The coupling agent is a silane coupling agent KH570; the reinforcing fiber is a nano boron fiber; the average diameter of the reinforcing fiber is 70 nm, and the average aspect ratio is 33:1; the antioxidant is antioxidant 1010; the lubricant is ethylene bisstearamide.

[0053] The hydroxyl-terminated hyperbranched polyester is hydroxyl-terminated hyperbranched polyester Hyper H203, provided by Wuhan Hyperbranched Resin Technology Co., Ltd.; the nano-filler is nano-silica; the particle size of the nano-filler is 60 nm; the photoinitiator is benzoin ethyl ether; the catalyst A is dibutyltin dilaurate DY-12; the diluent is a mixture of methyl methacrylate, butyl methacrylate, and hydroxypropyl methacrylate in a mass ratio of 1:1.5:1.

[0054] A method for preparing the MLCC release film base film includes the following steps:

[0055] Step S1: Mix the raw materials for the core layer evenly by weight to obtain a mixed material, and then form a sheet through melt extrusion, casting, and film casting in sequence; then obtain the core layer film material through biaxial stretching.

[0056] Step S2: Mix the components of the functional coating layer evenly, degas under vacuum, coat on the outer surface of the core layer, and obtain the MLCC release film base film after curing and drying.

[0057] In step S1, the temperature of the melt extrusion is 250 °C; the temperature of the casting is 270 °C; the temperature of the film casting roll for film casting is 28 °C; in step S1, the stretching temperature for biaxial stretching is 115 °C, the stretching rate is 105 mm / s, the heat setting temperature is 240 °C, and the stretching ratio is 4.

[0058] In step S2, the coating method is micro gravure coating; the curing is carried out under ultraviolet light with a wavelength of 235 nm for 30 min; the drying is carried out at 85 °C for 4 min; the thickness of the core layer is 25 μm, and the thickness of the functional coating layer is 100 nm.

[0059] Example 4: An MLCC release film base film, comprising a core layer and a functional coating layer provided on the outer surface of the core layer; the core layer is made of the following raw materials by weight: 100 parts of PET resin, 23 parts of a functional polyester containing a triazolyl tetrafluorophenyl group, 4.5 parts of a coupling agent, 7.5 parts of reinforcing fiber, 1.8 parts of an antioxidant, and 1.1 parts of a lubricant; the functional polyester containing a triazolyl tetrafluorophenyl group includes structural units introduced by the following monomers: N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluoroterephthalyl alcohol; the functional coating layer is made of the following components by weight: 28 parts of a hydroxyl-terminated hyperbranched polyester, 9.5 parts of isocyanatoethyl methacrylate, 2.5 parts of vinyltrimethoxysilane, 4.5 parts of nano filler, 1.8 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone, 2.5 parts of 2,2'-bis(trifluoromethyl)diaminobiphenyl, 0.75 part of a photoinitiator, 0.55 part of catalyst A, and 23 parts of a diluent.

[0060] The PET resin has the brand name PET CZ-333 and is provided by Jiangyin Xingye.

[0061] The preparation method of the functional polyester containing a triazolyl tetrafluorophenyl group comprises the following steps: adding N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluoroterephthalyl alcohol, and catalyst B into a high-boiling solvent, stirring at 128 °C for 2.5 hours to obtain a reaction solution, then adding the reaction solution into a high-pressure reaction kettle, closing the feeding port after the feeding is completed, purging the air in the reaction kettle with an inert gas, then stirring and reacting at 145 °C under normal pressure for 4.5 hours, then reducing the pressure to 50 Pa, raising the temperature to 265 °C, maintaining the temperature and pressure and stirring and reacting for 12 hours, cooling to room temperature after the reaction is completed, precipitating in water, then washing the precipitated polymer with ethanol 6 times, and finally drying to constant weight at 93 °C in a vacuum dryer to obtain the functional polyester containing a triazolyl tetrafluorophenyl group; the molar ratio of N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluoroterephthalyl alcohol, catalyst B, and high-boiling solvent is 1:1:1.1:14; the high-boiling solvent is dimethyl sulfoxide; the catalyst B is a mixture formed by mixing ethylene glycol antimonate, tetrabutyl titanate, and p-toluenesulfonic acid in a molar ratio of 1:1.1:0.55; the inert gas is argon.

[0062] The coupling agent is silane coupling agent KH550; the reinforcing fiber is carbon nanofiber; the average diameter of the reinforcing fiber is 90 nm, and the average aspect ratio is 38:1; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:2; the lubricant is a mixture of pentaerythritol stearate and ethylene bisstearamide in a mass ratio of 3:5; the hydroxyl-terminated hyperbranched polyester is hydroxyl-terminated hyperbranched polyester Hyper H203 provided by Wuhan Hyperbranched Resin Technology Co., Ltd.; the nano filler is a mixture of nano silica and nano calcium carbonate in a mass ratio of 2:3; the particle size of the nano filler is 70 nm; the photoinitiator is benzoin ethyl ether; the catalyst A is a mixture of dibutyltin dilaurate DY-12 and organobismuth DY-20 in a mass ratio of 3:5; the diluent is a mixture of methyl methacrylate, butyl methacrylate, and hydroxypropyl methacrylate in a mass ratio of 1:1.8:1.1.

[0063] A preparation method of the MLCC release film base film comprises the following steps:

[0064] Step S1: After uniformly mixing the raw materials for preparing the core layer according to parts by weight, a mixed material is obtained, and then it is successively subjected to melt extrusion, casting, and sheet casting to form a sheet; and then a core layer film material is obtained through biaxial stretching.

[0065] Step S2: The components of the functional coating layer are uniformly mixed, and after vacuum degassing, it is coated on the outer surface of the core layer, and after curing and drying, the MLCC release film base film is obtained.

[0066] In step S1, the temperature of the melt extrusion is 255 °C; the temperature of the casting is 275 °C; the temperature of the casting roll for sheet casting is 29 °C; in step S1, the stretching temperature of the biaxial stretching is 118 °C, the stretching rate is 115 mm / s, the heat setting temperature is 245 °C, and the stretching ratio is 4.

[0067] In step S2, the coating method is micro gravure coating; the curing is carried out under ultraviolet light with a wavelength of 245 nm for 33 min; the drying is carried out at 88 °C for 4.5 min; the thickness of the core layer is 25 μm, and the thickness of the functional coating layer is 100 nm.

[0068] Example 5: An MLCC release film base film, comprising a core layer and a functional coating layer provided on the outer surface of the core layer; the core layer is made of the following raw materials by weight: 100 parts of PET resin, 25 parts of a functional polyester containing a triazolyl tetrafluorophenyl group, 5 parts of a coupling agent, 8 parts of reinforcing fibers, 2 parts of an antioxidant, and 1.2 parts of a lubricant; the functional polyester containing a triazolyl tetrafluorophenyl group includes structural units introduced by the following monomers: N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluoroterephthalyl alcohol; the functional coating layer is made of the following components by weight: 30 parts of a hydroxyl-terminated hyperbranched polyester, 10 parts of isocyanatoethyl methacrylate, 3 parts of vinyltrimethoxysilane, 5 parts of a nano filler, 2 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone, 3 parts of 2,2'-bis(trifluoromethyl)diaminobiphenyl, 0.8 part of a photoinitiator, 0.6 part of catalyst A, and 25 parts of a diluent.

[0069] The PET resin has the brand name PET CZ-333 and is provided by Jiangyin Xingye.

[0070] The preparation method of the functional polyester containing a triazolyl tetrafluorophenyl group comprises the following steps: adding N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluoroterephthalyl alcohol, and catalyst B into a high-boiling solvent, stirring at 130°C for 3 hours to obtain a reaction solution, then adding the reaction solution into a high-pressure reaction kettle, closing the feeding port after the feeding is completed, purging the air in the reaction kettle with an inert gas, then stirring and reacting at 150°C under normal pressure for 5 hours, then reducing the pressure to 60 Pa, raising the temperature to 270°C, maintaining the temperature and pressure and stirring and reacting for 13 hours, cooling to room temperature after the reaction is completed, precipitating in water, then washing the precipitated polymer with ethanol 6 times, and finally drying in a vacuum dryer at 95°C to constant weight to obtain the functional polyester containing a triazolyl tetrafluorophenyl group; the molar ratio of N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluoroterephthalyl alcohol, catalyst B, and the high-boiling solvent is 1:1:1.2:15; the high-boiling solvent is dimethyl sulfoxide; the catalyst B is a mixture formed by mixing ethylene glycol antimonate, tetrabutyl titanate, and p-toluenesulfonic acid in a molar ratio of 1:1.2:0.6; the inert gas is nitrogen.

[0071] The coupling agent is silane coupling agent KH550; the reinforcing fiber is nano boron fiber; the average diameter of the reinforcing fiber is 100 nm, and the average aspect ratio is 40:1; the antioxidant is antioxidant 1010; the lubricant is ethylene bisstearamide; the hydroxyl-terminated hyperbranched polyester is hydroxyl-terminated hyperbranched polyester Hyper H203 provided by Wuhan Hyperbranched Resin Technology Co., Ltd.; the nano filler is nano silica; the particle size of the nano filler is 80 nm; the photoinitiator is benzoin ethyl ether; the catalyst A is organic bismuth DY-20; the diluent is a mixture of methyl methacrylate, butyl methacrylate, and hydroxypropyl methacrylate in a mass ratio of 1:2:1.2.

[0072] A preparation method of the MLCC release film base film includes the following steps:

[0073] Step S1: After uniformly mixing the raw materials for the core layer by weight, a mixed material is obtained, and then through melt extrusion, casting, and sheet casting in sequence to form a sheet; then a core layer film material is obtained through biaxial stretching.

[0074] Step S2: Mix the components of the functional coating layer evenly, perform vacuum degassing, then coat on the outer surface of the core layer, and after curing and drying, obtain the MLCC release film base film.

[0075] In step S1, the temperature of the melt extrusion is 260 °C; the temperature of the casting is 280 °C; the temperature of the casting roll for sheet casting is 30 °C; in step S1, the stretching temperature for the biaxial stretching is 120 °C, the stretching rate is 120 mm / s, the heat setting temperature is 250 °C, and the stretching ratio is 4.

[0076] In step S2, the coating method is micro gravure coating; the curing is carried out under ultraviolet light with a wavelength of 250 nm for 35 min; the drying is carried out at 90 °C for 5 min; the thickness of the core layer is 25 μm, and the thickness of the functional coating layer is 100 nm.

[0077] Comparative example 1: An MLCC release film base film and its preparation method are basically the same as those in Example 1, except that 3,3'-diamino-4,4'-difluorodiphenyl sulfone is not added, and terephthalic acid is used to replace N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid.

[0078] Comparative example 2: An MLCC release film base film and its preparation method are basically the same as those in Example 1, except that 2,2'-bis(trifluoromethyl)diaminobiphenyl is not added, and ethylene glycol is used to replace 2,3,5,6-tetrafluoroterephthalyl alcohol.

[0079] To further illustrate the beneficial technical effects of the MLCC release film base films involved in the embodiments of the present invention, relevant performance tests were conducted on the MLCC release film base films involved in Embodiments 1-5 and Comparative Examples 1-2; the test methods are as follows:

[0080] (1) Roughness detection standard: ISO 25178, instrument: Keyence VK-X1000 shape measurement laser microscopy system from Japan;

[0081] (2) Heat resistance: On the base film, 5 A3 (297 mm × 420 mm) size samples were evenly taken horizontally and laid flat on a flat black marble slab. Use a feeler gauge to measure the gaps between the four corners and the four edges of the samples and the marble slab, and record H1; then place them in a constant temperature oven at 150 °C for heat treatment for 2 seconds; after the treated samples are laid flat on a flat black marble slab, use a feeler gauge to measure the gaps between the four corners and the four edges of the samples and the marble slab, and record H2; take the average value of H1 and H2. Rating is carried out according to the following method:

[0082] △: H1 = 0, H2 ≤ 0.15 mm;

[0083] ▲: H1 ≤ 0.15 mm, H2 ≤ 0.2 mm;

[0084] ■: H1 > 0.15 mm, H2 > 0.2 mm;

[0085] Among them, △ and ▲ are qualified, and ■ is unqualified.

[0086] (3) Flatness: After the base film is heat-treated in a constant temperature oven at 150 °C, visually observe: if the film surface is not warped, without concave-convex points, stripes and other defects, it is a good product, and the rest are unqualified products.

[0087] (4) Warpage test method: Make the sample to be tested into A4 size, then lay it flat and put it into the oven at 170 °C for 30 min. After the temperature is 23 °C ± 2 °C and the relative humidity is 45% - 55%, place it for 30 min, then lay it flat on the glass substrate and use a steel ruler (accuracy 0.1 mm) to test the warpage, and the detection standard of GB / T25257-2010 can be referred to.

[0088] (5) Stiffness test method: Make the sample to be tested into 70 mm × 38 mm, use a stiffness tester, with an angle of 15°, test the stiffness, and conduct parallel tests 5 times and take the average value.

[0089] As can be seen from Table 1, compared with the products of the comparative examples, the MLCC release film base films involved in the embodiments of the present invention have lower roughness and warpage, better high-temperature resistance and flatness, and more suitable stiffness; the combined use of 3,3'-diamino-4,4'-difluorodiphenyl sulfone, N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,2'-bis(trifluoromethyl)diaminobiphenyl and 2,3,5,6-tetrafluoroterephthalyl alcohol is beneficial to improving the above properties.

[0090]

[0091] The above embodiments are only used to illustrate the technical concept and characteristics of the present invention, and their purpose is to enable those familiar with this technology to understand the content of the present invention and implement it accordingly, and it cannot be used to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A MLCC release film base film, characterized in that: The invention comprises a core layer and a functional coating layer arranged on the outer surface of the core layer; the core layer is made of the following raw materials in parts by weight: 100 parts of PET resin, 15-25 parts of functional polyester containing triazolyl tetrafluorophenyl, 3-5 parts of coupling agent, 5-8 parts of reinforcing fiber, 1-2 parts of antioxidant, and 0.8-1.2 parts of lubricant; the functional polyester containing triazolyl tetrafluorophenyl comprises a structural unit introduced by the following monomers: N-(4H-1,2,4-triazol-4-yl) diphenylamine-4 ,4'-dicarboxylic acid, 2,3,5,6-tetrafluorophenylene glycol; the functional coating layer includes the following components in parts by weight: 20-30 parts of terminal hydroxyl hyperbranched polyester, 8-10 parts of isocyanatoethyl methacrylate, 1-3 parts of vinyltrimethoxysilane, 3-5 parts of nanofiller, 1-2 parts of 3,3'-diamino-4,4'-difluorodiphenyl sulfone, 1-3 parts of 2,2'-bis(trifluoromethyl)diaminobiphenyl, 0.5-0.8 parts of photoinitiator, 0.3-0.6 parts of catalyst A, and 15-25 parts of diluent.

2. The MLCC release film base film according to claim 1, characterized in that: The grade of the PET resin is PET CZ-333.

3. The MLCC release film base film according to claim 1, characterized in that: The preparation method of the functional polyester containing triazolyl tetrafluorophenyl comprises the following steps: adding N-(4H-1,2,4-triazol-4-yl) diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluorophenylene glycol and catalyst B into a high boiling point solvent, stirring for 1-3 hours at 115-130 DEG C to obtain a reaction solution, then adding the reaction solution into a high pressure reactor, closing the feeding port after the addition, replacing the air in the reactor with an inert gas, then stirring and reacting for 3-5 hours at 130-150 DEG C under normal pressure, then reducing the pressure to 10-60 Pa, heating to 250-270 DEG C, stirring and reacting for 8-13 hours while maintaining the temperature and pressure, cooling to room temperature after the reaction, precipitating in water, washing the precipitated polymer with ethanol for 3-6 times, and finally drying in a vacuum dryer at 85-95 DEG C to constant weight to obtain the functional polyester containing triazolyl tetrafluorophenyl.

4. The MLCC release film base film according to claim 3, characterized in that: The molar ratio of N-(4H-1,2,4-triazole-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3,5,6-tetrafluorophenylenedimethanol, catalyst B, and high boiling point solvent is 1:1:(0.8-1.2):(10-15); the high boiling point solvent is dimethyl sulfoxide; the catalyst B is a mixture of ethylene glycol antimony, tetrabutyl titanate, and p-toluenesulfonic acid in a molar ratio of 1:(0.8-1.2):(0.3-0.6); the inert gas is any one of nitrogen, helium, neon, and argon.

5. The MLCC release film base film according to claim 1, characterized in that: The coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570; the reinforcing fiber is at least one of nano-boron fiber and carbon nano-fiber; the average diameter of the reinforcing fiber is 10-100nm, and the average aspect ratio is (25-40):

1.

6. The MLCC release film base film according to claim 1, characterized in that: The antioxidant is at least one of antioxidant 1010 and antioxidant 168; the lubricant is at least one of pentaerythritol stearate and ethylene bisstearamide.

7. The MLCC release film base film according to claim 1, characterized in that: The terminal hydroxyl hyperbranched polyester is terminal hydroxyl hyperbranched polyester Hyper H203; the nanofiller is at least one of nano silicon dioxide and nano calcium carbonate; the particle size of the nanofiller is 20-80nm; the photoinitiator is benzoin ethyl ether; the catalyst A is at least one of dibutyltin dilaurate DY-12 and organic bismuth DY-20; the diluent is methyl methacrylate, butyl methacrylate, and hydroxypropyl methacrylate mixed in a mass ratio of 1:(1-2):(0.8-1.2).

8. A method for preparing an MLCC release film base film, applicable to the MLCC release film base film according to any one of claims 1 to 7, characterized in that: The steps include: Step S1, after the raw materials for the core layer are uniformly mixed by weight, a mixed material is obtained, and then a sheet is formed by melt extrusion, casting and sheet casting in sequence; and then a core layer film material is obtained by biaxial stretching; Step S2, mix the components of the functional coating layer evenly, apply them on the outer surface of the core layer after vacuum degassing, and obtain the MLCC release film base film after curing and drying.

9. The method for preparing the MLCC release film base film according to claim 8, characterized in that: The temperature of the melt extrusion in step S1 is 240-260°C; the temperature of the casting is 260-280°C; the temperature of the casting roller of the cast sheet is 25-30°C; the stretching temperature of the biaxial stretching in step S1 is 110-120°C, the stretching rate is 90-120mm / s, the heat setting temperature is 230-250°C, and the stretching ratio is 3-5.

10. The method for preparing the MLCC release film base film according to claim 8, characterized in that: The coating method in step S2 is micro-gravure coating; the curing is performed under ultraviolet light with a wavelength of 220-250nm for 25-35min; the drying is performed at 80-90°C for 3-5min; the thickness of the core layer is 20-25μm, and the thickness of the functional coating layer is 100nm.

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