Functional masterbatch for MLCC film and preparation method for functional masterbatch

Abstract

Disclosed in the present invention are a functional masterbatch for an MLCC film and a preparation method for the functional masterbatch. The method comprises the following steps: S1. carrying out a surface etching treatment on nano SiO2 using an alkali to obtain a thick nano SiO2 slurry; S2. mixing the thick nano SiO2 slurry with ethylene glycol, then adding a dispersing agent, and sand milling the mixture to obtain a nano SiO2 dispersion; and S3. uniformly mixing the nano SiO2 dispersion, terephthalic acid, ethylene glycol, and a catalyst, and heating the mixture for an esterification reaction; and when the esterification reaction is completed, adding a stabilizer, heating the mixture for a polycondensation reaction, and when the reaction is completed, cooling and granulating the reaction product to obtain the functional masterbatch for an MLCC film. In the present invention, a masterbatch for an MLCC release film is synthesized in one step by using a direct esterification method, and the film is directly prepared. Compared with a coating method, the process is simpler, more stable, more controllable, and easier to achieve mass production; moreover, the nano SiO2 dispersion prepared in the present invention has better dispersity, and the obtained release film has a high surface flatness and is easy to peel.

Description

Functional masterbatch for MLCC film and preparation method thereof Technical Field

[0001] The present invention relates to the field of release film materials, and in particular to a functional masterbatch for MLCC films and a preparation method thereof. Background Art

[0002] MLCCs, also known as chip multilayer ceramic capacitors, offer advantages such as high capacitance, small size, low cost, and high stability. They are widely used in communications, electrical appliances, aerospace, and other fields, and are the world's most widely used chip electronic component with the highest market share. In recent years, with the breakthroughs and developments in industries such as smartphones, new energy vehicles, and 5G communications, MLCCs have shown a trend towards miniaturization, thinning, and higher capacity to achieve higher capacitance efficiency. The thickness of the ceramic dielectric layer continues to decrease, and the number of stacked layers increases, making them susceptible to damage. This places high demands on the surface properties of the release film that supports the ceramic dielectric layer, namely, high surface flatness and good anti-adhesion properties, while ensuring that the surface roughness of the release film is minimized while ensuring easy peeling.

[0003] Currently, the main method for preparing MLCC release film is surface coating, which involves surface treatment of the PET base film, including coating with silicone release agents, fluorine release agents, or plasma treatment, to promote the bonding of silicone oil to the base film surface and improve the peeling effect on the ceramic dielectric layer, thereby increasing the base film's release force and residual adhesion. In addition, some researchers have added inorganic particles to form functional masterbatches through in-situ copolymerization. The masterbatches are then pelletized, cast, and stretched to directly produce MLCC release film. This method has a short process, is simpler to operate, and effectively improves the flatness and smoothness of the release film surface, promising promising applications.

[0004] Patent CN 117106220 A uses a surface coating method to produce a low-roughness MLCC release film. This involves stretching a cast sheet to obtain a thick PET film. The surface of the PET film is then plasma-treated and coated with modified silicone oil to promote bonding between the oil and the film. UV light pre-curing is then followed by a secondary coating. After secondary stretching, heat setting, and deep curing, the low-roughness MLCC release film is obtained. However, this method uses multiple layers of coating, resulting in poor release layer stability. The processing steps are complex and require strict process control, which limits the mass production of release films.

[0005] Patent CN110239185 B synthesizes a functional masterbatch for MLCC release film. The inorganic particles added to the masterbatch have a large particle size and a wide dispersion. Although this improves the peelability of the release film, it results in a high surface roughness and poor flatness of the release film, limiting its application in high-end fields.

[0006] Patent CN115322533 A synthesizes a masterbatch specifically for MLCC release film. It uses a nano-SiO2 solution in ethylene glycol, adds a dispersant, and sand-mills the resulting dispersion. After the esterification stage, the dispersion is added to a polycondensation system for in-situ polymerization to synthesize the functional masterbatch. The MLCC release film is then obtained through granulation, sheet casting, and stretching. This method is simpler than the coating method, but the addition of ethylene glycol during the polycondensation stage promotes the formation of diethylene glycol, resulting in a high diethylene glycol content in the PET masterbatch, which affects the thermal stability of the release film. Furthermore, the resulting masterbatch has a high end carboxyl group count, which affects the processability of the release film.

[0007] It can be seen from the above solutions that both online coating and synthetic functional masterbatch have certain limitations, so it is necessary to improve the existing technology to provide a more reliable solution. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a functional masterbatch for MLCC film and a preparation method thereof in view of the deficiencies in the above-mentioned prior art.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for preparing a functional masterbatch for MLCC film, comprising the following steps:

[0010] S1, using alkali to etch the surface of nano-SiO2 to obtain nano-SiO2 concentrated slurry;

[0011] S2, mixing the nano-SiO2 slurry obtained in step S1 with ethylene glycol, adding a dispersant, and sand-milling to obtain a nano-SiO2 dispersion;

[0012] S3. Evenly mix the nano-SiO2 dispersion obtained in step S2, terephthalic acid, ethylene glycol, and a catalyst, and heat to carry out an esterification reaction. After the esterification reaction is completed, add a stabilizer, heat to carry out a polycondensation reaction, cool after the reaction is completed, and pelletize to obtain a functional masterbatch for MLCC film.

[0013] Preferably, step S1 is specifically:

[0014] Add nano-SiO2 into the alkaline solution to prepare a solid content of 5-25%, c(OH - )=0.001~1 mol / L, stirring at a temperature of 20~50 ℃ for 1~24h, filtering the obtained slurry under stirring, washing, when the pH value of the filtrate is 7.5-8.5 and the conductivity is lower than 60μS / cm, washing is completed, heating at 80~120 ℃ to remove part of the water, and obtaining a nano-SiO2 concentrated slurry with a solid content of 40~70%.

[0015] Preferably, the particle size of nano-SiO2 is 30 to 100 nm.

[0016] Preferably, the alkaline solution is a solution made of at least one of NaOH, KOH, Ca(OH)2, and Ba(OH)2.

[0017] Preferably, step S2 is specifically:

[0018] Add ethylene glycol to the nano-SiO2 concentrated slurry obtained in step S1, heat to remove moisture, place in a sand mill, add a dispersant, and sand mill at a speed of 600-5000 r / min for 0.5-6 hours to obtain a nano-SiO2 dispersion with a solid content of 5-30%.

[0019] Preferably, the dispersant is polyethylene glycol, wherein the polyethylene glycol is at least one of polyethylene glycol 200, polyethylene glycol 400, and polyethylene glycol 600.

[0020] Preferably, step S3 is specifically:

[0021] The nano-SiO2 dispersion obtained in step S2, terephthalic acid, ethylene glycol, and catalyst are mixed and added to the reactor, and an esterification reaction is carried out at a temperature of 220-240°C, a pressure of 0.3-0.35 MPa, an N2 atmosphere, and stirring. The reaction progress is measured by the esterification water output, the reactor temperature, and the distillation tower top temperature. After the esterification reaction is completed, a stabilizer is added, and the reactor pressure is slowly pumped from 100 kPa to a vacuum degree of ≤40 Pa within 30-50 minutes at a temperature of 245-265°C, and then the temperature is raised to 265-280°C for a condensation reaction. When the reactants reach the set viscosity, the reaction is stopped, cooled, and pelletized to obtain functional masterbatch for MLCC release film.

[0022] Preferably, the molar ratio of the amount of terephthalic acid added in step S3 to the total amount of ethylene glycol in the reaction system is 1:1.05 to 1:1.6.

[0023] Preferably, the catalyst is an antimony-based catalyst, specifically at least one of Sb2(EG)3, Sb(Ac)3, and Sb2O3, wherein the Sb content is 100 to 300 ppm;

[0024] The stabilizer is at least one of phosphoric acid, phosphorous acid, polyphosphoric acid, phosphite, trimethyl phosphate, triethyl phosphate, and triphenyl phosphate, wherein the phosphorus content is 5 to 50 ppm;

[0025] The present invention also provides a functional masterbatch for MLCC film, which is prepared by the method as described above. The components of the functional masterbatch for MLCC film include, by mass fraction: 98.5-99.8% polyethylene terephthalate, 0.1-1% nano-SiO2, 0.02-0.07% catalyst, 0.002-0.03% dispersant, and 0.01-0.03% stabilizer.

[0026] The beneficial effects of the present invention are:

[0027] The present invention provides a functional masterbatch for MLCC release film and a preparation method thereof. The present invention adopts a direct esterification method to synthesize the masterbatch for MLCC release film in one step, and directly prepares the film. Compared with the coating method, the process is simpler, more stable, more controllable, and easier to achieve mass production. The nano-SiO2 dispersion prepared by the present invention has better dispersibility, and the obtained release film has a high surface smoothness and is easy to peel off.

[0028] The present invention etches the surface of nano-SiO2 to increase the surface potential value of SiO2, improve dispersion in the polymerization system, and inhibit agglomeration; secondly, -OH is grafted on the SiO2 surface to enhance the surface polarity of SiO2, and the formed pores increase the specific surface area of ​​nano-SiO2, thereby promoting the compatibility of SiO2 with PET molecules; and the process of esterification reaction can be promoted in an alkaline environment, thereby inhibiting the formation of diethylene glycol, effectively inhibiting side reactions in esterification and polycondensation reactions, and enhancing the thermal stability of PET; finally, compared with organic modification, the cost of alkaline etching is lower, the -OH on the SiO2 surface and the free OH- in the esterification system have substantially no catalytic activity on side reactions, and the obtained PET has better stability and better color value.

[0029] Compared with micron SiO2, the nano-SiO2 selected as the opening agent in the present invention has less influence on the optical properties of the release film, and is easy to disperse on the surface, so the obtained release film has lower roughness and a smoother surface.

[0030] The present invention selects polyethylene glycol as a dispersant, which improves the dispersion effect of SiO2 in the polymerization system without introducing active ingredients, and is more conducive to the stable progress of the reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG1 is a SEM image of the brittle fracture cross section of the masterbatch obtained in Example 2. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below with reference to the embodiments so that those skilled in the art can implement the invention with reference to the description.

[0033] It should be understood that terms such as “having”, “including” and “comprising” used herein do not preclude the existence or addition of one or more other elements or combinations thereof.

[0034] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Materials and reagents used in the following examples are commercially available unless otherwise specified. In the following examples, where specific conditions are not specified, the experiments were conducted under conventional conditions or those recommended by the manufacturer. Reagents and instruments used, where the manufacturer is not specified, are commercially available conventional products.

[0035] The present invention provides a functional masterbatch for MLCC film. The components thereof include, by mass fraction, 98.5-99.8% of polyethylene terephthalate, 0.1-1% of nano-SiO2, 0.02-0.07% of a catalyst, 0.002-0.03% of a dispersant, and 0.01-0.03% of a stabilizer.

[0036] The preparation method of the functional masterbatch for MLCC film comprises the following steps:

[0037] S1. Use alkali to etch the surface of nano-SiO2 to obtain nano-SiO2 concentrated slurry:

[0038] Add nano-SiO2 into the alkaline solution to prepare a solid content of 5-25%, c(OH - )=0.001~1 mol / L, stirring at a temperature of 20~50 ℃ for 1~24h, filtering the obtained slurry under stirring, washing, when the pH value of the filtrate is 7.5-8.5 and the conductivity is lower than 60μS / cm, washing is completed, heating at 80~120 ℃ to remove part of the water, and obtaining a nano-SiO2 concentrated slurry with a solid content of 40~70%.

[0039] S2. Add ethylene glycol to the nano-SiO2 slurry obtained in step S1, heat to remove moisture, place in a sand mill, add a dispersant, and sand mill at a speed of 600-5000 r / min for 0.5-6 hours to obtain a nano-SiO2 dispersion with a solid content of 5-30%.

[0040] S3. Mix the nano-SiO2 dispersion obtained in step S2, terephthalic acid, ethylene glycol, and catalyst and add them to the reactor. Perform esterification reaction at a temperature of 220-240°C, a pressure of 0.3-0.35 MPa, an N2 atmosphere, and stirring. The reaction progress is measured by the esterification water output, the reactor temperature, and the distillation tower top temperature. After the esterification reaction is completed, add a stabilizer, and at a temperature of 245-265°C, slowly pump the reactor pressure from 100 kPa to a vacuum degree of ≤40 Pa within 30-50 minutes. Then raise the temperature to 265-280°C and perform polycondensation reaction. When the reactants reach the set viscosity, stop the reaction, cool, and pelletize to obtain functional masterbatch for MLCC release film.

[0041] In a preferred embodiment, the particle size of nano-SiO2 is 30-100 nm.

[0042] In a preferred embodiment, the alkaline solution is a solution made of at least one of NaOH, KOH, Ca(OH)2, and Ba(OH)2.

[0043] In the present invention, a strong base is added to etch the surface of nano-SiO2, thereby increasing the surface potential value of SiO2, improving its dispersibility in the polymerization system, and inhibiting the nano-agglomeration effect; secondly, hydroxyl groups are grafted on the surface of SiO2, which can enhance the surface polarity of SiO2, and the formed pores increase the specific surface area of ​​nano-SiO2, thereby promoting the compatibility of SiO2 with PET molecules; and the alkaline environment can promote the progress of esterification reaction, inhibit etherification reaction to a certain extent, inhibit the formation of diethylene glycol, thereby enhancing the thermal stability of PET; finally, compared with organic modification, the cost of alkaline etching is lower, and the -OH group on the surface of SiO2 and the free OH group in the esterification system are reduced. - It has basically no catalytic activity for side reactions, and the obtained PET has better stability and better color value.

[0044] In addition, compared with the traditional high-temperature drying and grinding process, the SiO2 concentrated slurry prepared in step 1 of the present invention can retain the -OH group on the SiO2 surface as much as possible and inhibit the shrinkage and epoxidation of -OH group.

[0045] In a preferred embodiment, the dispersant is polyethylene glycol, wherein the polyethylene glycol is at least one of polyethylene glycol 200, polyethylene glycol 400, and polyethylene glycol 600.

[0046] Polyethylene glycol can form hydrogen bonds with the surface of nano-SiO2, reducing its surface tension and further inhibiting SiO2 agglomeration. Compared with organic modifiers such as silane coupling agents and surfactants, the addition of polyethylene glycol does not introduce new active functional groups and active sites, nor does it catalyze side reactions during the polymerization stage. It has better stability and better color value of PET masterbatch.

[0047] In the traditional method, nano-SiO2 dispersion is usually added after the esterification reaction in step S3 is completed. This solution is equivalent to adding additional ethylene glycol, which will etherify to form DEG (diethylene glycol) at the subsequent high temperature (during the final polycondensation reaction), destroying the PET chain structure and affecting the thermal stability of PET. The addition of nano-SiO2 dispersion during the esterification stage of the present invention can avoid this problem.

[0048] In step S3 of the present invention, a direct esterification method is used to synthesize the masterbatch for MLCC release film in one step, and the film is directly prepared. Compared with the coating method, the process is simpler, more stable, more controllable, and easier to achieve quantitative production.

[0049] In a preferred embodiment, the molar ratio of the amount of terephthalic acid added in step S3 to the total amount of ethylene glycol in the reaction system (i.e., the sum of the amounts of ethylene glycol added in steps S2 and S3) is 1:1.05 to 1:1.6.

[0050] In a preferred embodiment, the catalyst is an antimony-based catalyst, specifically at least one of Sb2(EG)3, Sb(Ac)3, and Sb2O3, wherein the Sb content is 100 to 300 ppm.

[0051] In a preferred embodiment, the stabilizer is at least one of phosphoric acid, phosphorous acid, polyphosphoric acid, phosphite, trimethyl phosphate, triethyl phosphate, and triphenyl phosphate, wherein the phosphorus content is 5 to 50 ppm.

[0052] In a preferred embodiment, in step S3, the esterification reaction is controlled to end when the esterification water output reaches 50-90 mL, the reactor temperature reaches 220-240° C., and the distillation tower top temperature is lower than 100° C.

[0053] In a preferred embodiment, when the viscosity of the reactants in step S3 is 0.6 dL / g, the reaction is stopped and the material is discharged.

[0054] The above is the overall concept of the present invention. Detailed embodiments and comparative examples are provided below to further illustrate the present invention.

[0055] Example 1

[0056] A functional masterbatch for MLCC film, the preparation method of which comprises the following steps:

[0057] S1. Use alkali to etch the surface of nano-SiO2 to obtain nano-SiO2 concentrated slurry:

[0058] 70g of nano-SiO2 was added to the NaOH solution to prepare a solid content of 5%, c(OH - )=0.001mol / L, stirred at 20℃ for 24h, the obtained slurry was filtered and washed under stirring. When the pH value of the filtrate was 8 and the conductivity was lower than 60μS / cm, the washing was completed, and part of the water was removed by heating at 80℃ to obtain a nano-SiO2 concentrated slurry with a solid content of 70%.

[0059] S2. Add 155g of ethylene glycol to 100g of the nano-SiO2 slurry obtained in step S1, heat at 100°C to remove moisture, and place in a sand mill jar. Add 10g of polyethylene glycol 200 and sand mill at a speed of 600r / min for 6h to obtain a nano-SiO2 dispersion with a solid content of 30%.

[0060] S3. Mix 14g of the nano-SiO2 dispersion obtained in step S2, 350g of terephthalic acid, 134g of ethylene glycol, and 0.3g of Sb2(EG)3 and add them to the reactor. Carry out esterification reaction at a temperature of 220-240°C, a pressure of 0.3-0.35MPa, an N2 atmosphere, and stirring. When the esterification water output reaches 70ml, the reactor temperature reaches 240°C, and the temperature at the top of the distillation tower is lower than 100°C, the esterification reaction is terminated. 0.13g of triethyl phosphate is added, and at a temperature of 245-265°C, the reactor pressure is slowly evacuated from 100kPa to a vacuum degree of 40Pa within 30min, and then the temperature is raised to 265-280°C for polycondensation reaction. When the viscosity of the reactant reaches about 0.6dL / g, the reaction is stopped, cooled, and pelletized to obtain functional masterbatch for MLCC release film.

[0061] The components of the prepared functional masterbatch for MLCC release film include, by mass fraction: nano-SiO2 1%, Sb2(EG)3 0.07% (Sb mass proportion is about 0.03%), dispersant (polyethylene glycol 200) 0.16%, triethyl phosphate 0.03% (P mass proportion is about 0.005%), and the rest is polyethylene terephthalate.

[0062] Example 2

[0063] A functional masterbatch for MLCC film, the preparation method of which comprises the following steps:

[0064] S1. Use alkali to etch the surface of nano-SiO2 to obtain nano-SiO2 concentrated slurry:

[0065] 60g of nano-SiO2 was added to the NaOH solution to prepare a solution with a solid content of 10%, c(OH - )=0.01mol / L, stirred at 30℃ for 16h, the obtained slurry was filtered and washed under stirring. When the pH value of the filtrate was 8 and the conductivity was lower than 60μS / cm, the washing was completed, and part of the water was removed by heating at 90℃ to obtain a nano-SiO2 concentrated slurry with a solid content of 60%.

[0066] S2. Add 230 g of ethylene glycol to 100 g of the nano-SiO2 slurry obtained in step S1, heat at 100°C to remove moisture, and place in a sand mill jar. Add 10 g of polyethylene glycol 400 and sand mill at a speed of 1500 r / min for 4 h to obtain a nano-SiO2 dispersion with a solid content of 20%.

[0067] S3. Mix 15g of the nano-SiO2 dispersion obtained in step S2, 350g of terephthalic acid, 151g of ethylene glycol, and 0.26g of Sb(Ac)3 and add them to the reactor. Carry out esterification reaction at a temperature of 220-240°C, a pressure of 0.3-0.35MPa, an N2 atmosphere, and stirring. When the esterification water output reaches 70ml, the reactor temperature reaches 240°C, and the temperature at the top of the distillation tower is lower than 100°C, the esterification reaction is terminated. 0.084g of trimethyl phosphate is added, and at a temperature of 245-265°C, the reactor pressure is slowly evacuated from 100kPa to a vacuum degree of 40Pa within 40min, and then the temperature is raised to 265-280°C for polycondensation reaction. When the viscosity of the reactant reaches about 0.6dL / g, the reaction is stopped, cooled, and pelletized to obtain functional masterbatch for MLCC release film.

[0068] The components of the prepared functional masterbatch for MLCC release film include, by mass fraction: nano-SiO2 0.7%, Sb(Ac)3 0.06% (Sb mass proportion is about 0.025%), dispersant (polyethylene glycol 400) 0.1%, trimethyl phosphate 0.02% (P mass proportion is about 0.0044%), and the rest is polyethylene terephthalate.

[0069] Example 3

[0070] A functional masterbatch for MLCC film, the preparation method of which comprises the following steps:

[0071] S1. Use alkali to etch the surface of nano-SiO2 to obtain nano-SiO2 concentrated slurry:

[0072] 50g of nano-SiO2 was added to the NaOH solution to prepare a solution with a solid content of 15%, c(OH - )=0.1mol / L, stirred at 40℃ for 8h, the obtained slurry was filtered and washed under stirring. When the pH value of the filtrate was 8 and the conductivity was lower than 60μS / cm, the washing was completed, and part of the water was removed by heating at 110℃ to obtain a nano-SiO2 concentrated slurry with a solid content of 50%.

[0073] S2. Add 440 g of ethylene glycol to 100 g of the nano-SiO2 slurry obtained in step S1, heat at 100°C to remove moisture, and place in a sand mill jar. Add 10 g of polyethylene glycol 600 and sand mill at a speed of 4000 r / min for 2 h to obtain a nano-SiO2 dispersion with a solid content of 10%.

[0074] S3. Mix 16.8g of the nano-SiO2 dispersion obtained in step S2, 350g of terephthalic acid, 173g of ethylene glycol, and 0.26g of Sb2O3 and add them to the reactor. Carry out esterification reaction at a temperature of 220-240°C, a pressure of 0.3-0.35MPa, an N2 atmosphere, and stirring. When the esterification water output reaches 70ml, the reactor temperature reaches 240°C, and the distillation tower top temperature is lower than 100°C, the esterification reaction is terminated. 0.126g of triphenyl phosphate is added, and at a temperature of 245-265°C, the reactor pressure is slowly evacuated from 100kPa to a vacuum degree of 40Pa within 50min, and then the temperature is raised to 265-280°C for polycondensation reaction. When the viscosity of the reactant reaches about 0.6dL / g, the reaction is stopped, cooled, and pelletized to obtain functional masterbatch for MLCC release film.

[0075] The components of the prepared functional masterbatch for MLCC release film include, by mass fraction: nano-SiO2 0.4%, Sb2O3 0.025% (Sb mass proportion is about 0.02%), dispersant (polyethylene glycol 600) 0.08%, trimethyl phosphate 0.03% (P mass proportion is about 0.003%), and the rest is polyethylene terephthalate.

[0076] Example 4

[0077] A functional masterbatch for MLCC film, the preparation method of which comprises the following steps:

[0078] S1. Use alkali to etch the surface of nano-SiO2 to obtain nano-SiO2 concentrated slurry:

[0079] 40g of nano-SiO2 was added to the NaOH solution to prepare a solution with a solid content of 25%, c(OH - )=1mol / L slurry, stirred at a temperature of 50℃ for 1h, the obtained slurry was filtered and washed under stirring. When the pH of the filtrate was 8 and the conductivity was lower than 60μS / cm, the washing was completed, and part of the water was removed by heating at 120℃ to obtain a nano-SiO2 concentrated slurry with a solid content of 40%.

[0080] S2. Add 752 g of ethylene glycol to 100 g of the nano-SiO2 slurry obtained in step S1, heat at 100°C to remove moisture, and place in a sand mill jar. Add 8 g of polyethylene glycol 200 and sand mill at a speed of 5000 r / min for 0.5 h to obtain a nano-SiO2 dispersion with a solid content of 5%.

[0081] S3. Mix 8.4 g of the nano-SiO2 dispersion obtained in step S2, 350 g of terephthalic acid, 203 g of ethylene glycol, and 0.26 g of Sb2O3 and add them to the reactor. Carry out esterification reaction at a temperature of 220-240 ° C, a pressure of 0.3-0.35 MPa, an N2 atmosphere, and stirring. When the esterification water output reaches 70 ml, the reactor temperature reaches 240 ° C, and the distillation tower top temperature is lower than 100 ° C, the esterification reaction is terminated. 0.042 g of triphenyl phosphate is added, and at a temperature of 245-265 ° C, the reactor pressure is slowly evacuated from 100 kPa to a vacuum degree of 40 Pa within 50 minutes, and then the temperature is raised to 265-280 ° C for polycondensation reaction. When the viscosity of the reactant reaches about 0.6 dL / g, the reaction is stopped, cooled, and pelletized to obtain functional masterbatch for MLCC release film.

[0082] The components of the prepared functional masterbatch for MLCC release film include, by mass fraction: nano-SiO2 0.1%, Sb2O3 0.013% (Sb mass proportion is about 0.01%), dispersant (polyethylene glycol 200) 0.082%, triphenyl phosphate 0.01% (P mass proportion is about 0.001%), and the rest is polyethylene terephthalate.

[0083] Comparative Example 1

[0084] A PET masterbatch, the preparation method of which comprises the following steps:

[0085] S1. Add 60g of nano-SiO2, 230g of ethylene glycol, and 10g of polyethylene glycol 400 into a sand mill, and sand mill at a speed of 1500r / min for 4h to obtain a nano-SiO2 dispersion with a solid content of 20%.

[0086] S2. 350 g of terephthalic acid, 151 g of ethylene glycol, 15 g of SiO2 dispersion, and 0.26 g of Sb(Ac)3 were configured into a homogenous slurry and added to a reactor. An esterification reaction was carried out at a temperature of 220-240 ° C., a pressure of 0.3-0.35 MPa, an N2 atmosphere, and stirring. The esterification reaction was terminated when the esterification water output reached 70 ml, the reactor temperature reached 240 ° C., and the temperature of the distillation tower top was lower than 100 ° C. 0.084 g of trimethyl phosphate was added. At a temperature of 245-260 ° C., the reactor pressure was slowly evacuated from 100 kPa to a vacuum degree of less than or equal to 40 Pa within 40 minutes, and then the temperature was raised to 265-280 ° C. for final polycondensation. When the reactant reached about 0.6 dL / g, the reaction was stopped, cooled, and pelletized to obtain PET masterbatch.

[0087] Comparative Example 2

[0088] A PET masterbatch, the preparation method of which comprises the following steps:

[0089] S1. Use alkali to etch the surface of nano-SiO2 to obtain nano-SiO2 concentrated slurry:

[0090] 60g of nano-SiO2 with a particle size of 700nm was added to the NaOH solution to prepare a solution with a solid content of 10%, c(OH - )=0.01mol / L, stirred at 30℃ for 16h, the obtained slurry was filtered and washed under stirring. When the pH value of the filtrate was 8 and the conductivity was lower than 60μS / cm, the washing was completed, and part of the water was removed by heating at 90℃ to obtain a nano-SiO2 concentrated slurry with a solid content of 60%.

[0091] S2. Add 230 g of ethylene glycol to 100 g of the nano-SiO2 slurry obtained in step S1, heat at 100°C to remove moisture, and place in a sand mill jar. Add 10 g of polyethylene glycol 400 and sand mill at a speed of 1500 r / min for 4 h to obtain a nano-SiO2 dispersion with a solid content of 20%.

[0092] S3. Mix 15g of the nano-SiO2 dispersion obtained in step S2, 350g of terephthalic acid, 151g of ethylene glycol, and 0.26g of Sb(Ac)3 and add them to the reactor. Carry out esterification reaction at a temperature of 220-240°C, a pressure of 0.3-0.35MPa, an N2 atmosphere, and stirring. When the esterification water output reaches 70ml, the reactor temperature reaches 240°C, and the temperature at the top of the distillation tower is lower than 100°C, the esterification reaction is terminated. 0.084g of trimethyl phosphate is added, and at a temperature of 245-265°C, the reactor pressure is slowly evacuated from 100kPa to a vacuum degree of 40Pa within 40min, and then the temperature is raised to 265-280°C for polycondensation reaction. When the viscosity of the reactant reaches about 0.6dL / g, the reaction is stopped, cooled, and pelletized to obtain functional masterbatch for MLCC release film.

[0093] Comparative Example 3

[0094] A PET masterbatch, the preparation method of which comprises the following steps:

[0095] S1. Use alkali to etch the surface of nano-SiO2 to obtain nano-SiO2 concentrated slurry:

[0096] 60g of nano-SiO2 was added to the NaOH solution to prepare a solution with a solid content of 10%, c(OH - )=0.01mol / L, stirred at 30℃ for 16h, the obtained slurry was filtered and washed under stirring. When the pH value of the filtrate was 8 and the conductivity was lower than 60μS / cm, the washing was completed, and part of the water was removed by heating at 90℃ to obtain a nano-SiO2 concentrated slurry with a solid content of 60%.

[0097] S2. Add 230 g of ethylene glycol to 100 g of the nano-SiO2 slurry obtained in step S1, heat at 100°C to remove moisture, and place in a sand mill jar. Add 10 g of silane coupling agent KH-560 and sand mill at a speed of 1500 r / min for 4 h to obtain a nano-SiO2 dispersion with a solid content of 20%.

[0098] S3. Mix 15g of the nano-SiO2 dispersion obtained in step S2, 350g of terephthalic acid, 151g of ethylene glycol, and 0.26g of Sb(Ac)3 and add them to the reactor. Carry out esterification reaction at a temperature of 220-240°C, a pressure of 0.3-0.35MPa, an N2 atmosphere, and stirring. When the esterification water output reaches 70ml, the reactor temperature reaches 240°C, and the temperature at the top of the distillation tower is lower than 100°C, the esterification reaction is terminated. 0.084g of trimethyl phosphate is added, and at a temperature of 245-265°C, the reactor pressure is slowly evacuated from 100kPa to a vacuum degree of 40Pa within 40min, and then the temperature is raised to 265-280°C for polycondensation reaction. When the viscosity of the reactant reaches about 0.6dL / g, the reaction is stopped, cooled, and pelletized to obtain functional masterbatch for MLCC release film.

[0099] Comparative Example 4

[0100] A PET masterbatch, the preparation method of which comprises the following steps:

[0101] 350g of terephthalic acid, 151g of ethylene glycol, and 0.26g of Sb(Ac)3 were prepared into a homogenous slurry and added to a reactor. The esterification reaction was carried out at a temperature of 220-240°C, a pressure of 0.3-0.35MPa, an N2 atmosphere, and stirring. The esterification reaction was terminated when the esterification water output reached 70ml, the reactor temperature reached 240°C, and the temperature at the top of the distillation tower was lower than 100°C. 0.084g of trimethyl phosphate was added, and the reactor pressure was slowly evacuated from 100kPa to a vacuum degree of less than or equal to 40Pa at a temperature of 245-260°C within 40min. The temperature was then raised to 265-280°C for final polycondensation. When the reactant reached about 0.6dL / g, the reaction was stopped, cooled, and pelletized to obtain PET masterbatch.

[0102] The particle sizes of the nano-SiO2 in Examples 1-4 and Comparative Examples 1 and 3 are as follows:

[0103] Example 1: 30nm, Example 2: 60nm, Example 3: 80nm, Example 4: 120nm, Comparative Example 1: 60nm, Comparative Example 3: 60nm.

[0104] 1 , which is a SEM image of the brittle fracture cross-section of the masterbatch obtained in Example 2.

[0105] The functional masterbatch for MLCC release film obtained in Examples 1 to 4, the PET masterbatch obtained in Comparative Examples 1 to 4, and the performance parameters of the slices were tested according to the national standard "GB / T 14190-2017". The test results are shown in Table 1.

[0106] Table 1

[0107] The functional masterbatch for MLCC release film obtained in Examples 1 to 4, the PET masterbatch obtained in Comparative Examples 1 to 4, and the slices were granulated, then cast into sheets, extruded and stretched into films. The obtained films were tested in accordance with the standards "ASTM D1003", "ISO 4287" and "ASTM D882". The test results are shown in Table 2.

[0108] Table 2

[0109] According to the test results of Table 1 and Table 2, compared with Example 2:

[0110] In Comparative Example 1, the nano-SiO2 was not subjected to alkaline etching treatment, and the masterbatch dispersion was worse than that of Example 2. The agglomeration during the synthesis process was more serious, and the particle distribution was uneven; the surface haze and roughness of the release film were high, and the flatness was poor.

[0111] In comparative example 2, micron-sized SiO2 was added to perform in-situ synthesis of masterbatch. The surface roughness of the obtained release film was much higher than that of the masterbatch synthesized from nano-SiO2, and the flatness was poor. The particle size increased the haze of the release film, and the transmittance was low.

[0112] In Comparative Example 3, KH550 was added during the sand-milling stage to organically modify and disperse the nano-SiO2, and the resulting masterbatch had a worse color value. This was because the addition of KH560 provided additional active functional groups and active sites, which promoted the side reaction process, resulting in higher values ​​of diethylene glycol and terminal carboxyl groups, more short chains, irregular PET molecular segments, and a lower melting point. This also resulted in the release film exhibiting lower tensile strength and elongation at break.

[0113] In Comparative Example 4, no anti-blocking agent was added, and the release film showed lower haze and higher transmittance, but was too smooth and not resistant to sticking, and had poor mechanical properties.

[0114] In summary, the masterbatch for MLCC release film synthesized by the present invention has excellent performance parameters, the addition of nano-SiO2 enhances the crystallization ability of the masterbatch, and the obtained release film has excellent optical properties, a smooth surface and low roughness.

[0115] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. 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

1. A preparation method of a functional masterbatch for MLCC film, characterized in that, It includes the following steps: S1. Surface etching treatment of nano-SiO2 with alkali to obtain nano-SiO2 thick slurry; S2. Mix the nano-SiO2 thick slurry obtained in step S1 with ethylene glycol, then add a dispersant and grind it to obtain a nano-SiO2 dispersion; S3. Mix the nano-SiO2 dispersion, terephthalic acid, ethylene glycol and a catalyst obtained in step S2, heat for esterification reaction. After the esterification reaction is completed, add a stabilizer, heat for polycondensation reaction. After the reaction is completed, cool and pelletize to obtain a functional masterbatch for MLCC film.

2. The preparation method of the functional masterbatch for MLCC film according to claim 1, characterized in that, Step S1 is specifically: Add nano-SiO₂ to an alkaline solution to prepare a slurry with a solid content of 5-25% and c(OH - ) = 0.001-1 mol / L. Stir the slurry at a temperature of 20-50 °C for 1-24 h. Filter and wash the obtained slurry under stirring. When the pH of the filtrate is 7.5-8.5 and the conductivity is lower than 60 μS / cm, the washing is completed. Heat to remove part of the water at 80-120 °C to obtain a nano-SiO₂ thick slurry with a solid content of 40-70%.

3. The preparation method of the functional masterbatch for MLCC film according to claim 2, characterized in that, The particle size of the nano-SiO2 is 30 - 100 nm.

4. The preparation method of the functional masterbatch for MLCC film according to claim 2, characterized in that, The alkali solution is a solution made of at least one of NaOH, KOH, Ca(OH)2, Ba(OH)2.

5. The preparation method of the functional masterbatch for MLCC film according to claim 1, characterized in that, Step S2 is specifically: Add ethylene glycol to the nano-SiO2 thick slurry obtained in step S1, heat to remove water, then place it in a sand mill tank, add a dispersant, and grind at a rotation speed of 600 - 5000 r / min for 0.5 - 6 h to obtain a nano-SiO2 dispersion with a solid content of 5 - 30%.

6. The preparation method of the functional masterbatch for MLCC film according to claim 5, characterized in that, The dispersant is polyethylene glycol, and the polyethylene glycol is at least one of polyethylene glycol 200, polyethylene glycol 400, polyethylene glycol 600.

7. The preparation method of the functional masterbatch for MLCC film according to claim 1, wherein, Step S3 is specifically: Mix the nano-SiO2 dispersion, terephthalic acid, ethylene glycol and a catalyst obtained in step S2 and add them to a reaction kettle. Carry out esterification reaction under the conditions of a temperature of 220 - 240 °C, a pressure of 0.3 - 0.35 MPa, an N2 atmosphere and stirring. Measure the reaction process by the amount of water esterified, the temperature of the reaction kettle and the temperature at the top of the rectifying column. After the esterification reaction is completed, add a stabilizer. At a temperature of 245 - 265 °C, slowly pump the pressure of the reaction kettle from 100 kPa to a vacuum degree ≤ 40 Pa within 30 - 50 min, then raise the temperature to 265 - 280 °C for polycondensation reaction. When the reactant reaches the set viscosity, stop the reaction, cool and pelletize to obtain a functional masterbatch for MLCC release film.

8. The preparation method of the functional masterbatch for MLCC film according to claim 7, characterized in that, The molar ratio of the amount of terephthalic acid added in step S3 to the total amount of ethylene glycol in the reaction system is 1:1.05 - 1:1.

6.

9. The preparation method of the functional masterbatch for MLCC film according to claim 7, characterized in that, The catalyst is an antimony-based catalyst, specifically at least one of Sb2(EG)3, Sb(Ac)3, Sb2O3, and the content of Sb is 100 - 300 ppm; The stabilizer is at least one of phosphoric acid, phosphorous acid, polyphosphoric acid, phosphite, trimethyl phosphate, triethyl phosphate, triphenyl phosphate, and the content of phosphorus is 5 - 50 ppm; 10. A functional masterbatch for MLCC film, characterized in that, It is prepared by the method described in any one of claims 1 - 9. The components of this functional masterbatch for MLCC film include, by mass fraction: polyethylene terephthalate 98.5 - 99.8%, nano-SiO2 0.1 - 1%, catalyst 0.02 - 0.07%, dispersant 0.002 - 0.03%, stabilizer 0.01 - 0.03%.

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