MLCC release film base film and method for manufacturing the same

Abstract

The application provides an MLCC release film base film and a preparation method thereof, relates to the technical field of polyester films, and the MLCC release film base film is an ABC three-layer co-extrusion structure, wherein the A and C layers are face layers, and the B layer is a core layer; the material of the A layer comprises the following components: special polyester chips; modified master batch; the material of the B layer comprises the following components: special polyester chips; high-speed material; the material of the C layer comprises the following components: special polyester chips; special master batch; the MLCC release film base film provided by the application uses special polyester chips as the base material of the polyester film, and through the combination with the modified master batch and the synergistic effect between the components, the prepared MLCC release film base film has excellent stiffness, flatness and dimensional stability, and also has lower roughness, and meets the requirements of the MLCC thin-layer release film base film.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyester film, in particular to a MLCC release film base film and a preparation method thereof. BACKGROUND

[0002] MLCC, the abbreviation of Multilayer Ceramic Capacitor, is a kind of basic passive electronic components. With the rapid development of 5G communication and new energy vehicles, the consumption of MLCC has increased dramatically. The manufacturing process of MLCC is to uniformly coat ceramic slurry on the release film, print electrodes on the surface of the ceramic layer after drying, and then remove the release film after the ceramic layer, and go through the processes of lamination, cover making, lamination, degassing, sintering, chamfering, termination, end burning, end processing, appearance selection, testing, packaging, etc. to complete the production. As a high-consumption auxiliary material in the manufacturing process of MLCC, the market of MLCC release film is expanding significantly with the production quantity of MLCC.

[0003] With the development of MLCC towards thin layer and multi-layer, the performance requirements of the release film base film are also increasing. The ideal MLCC release film base film should have high flatness and low roughness to ensure that the MLCC release film has uniform release force, which is crucial to ensure the stacking quality of ceramic medium and the electrical performance of MLCC. At the same time, in order to withstand the mechanical and thermal stress in the production process, the MLCC release film base film also needs to have high stiffness to maintain its stability in the processes of coating, drying, printing electrodes, etc.

[0004] However, the MLCC release film base film in the prior art often cannot meet the above requirements at the same time. On the one hand, in order to improve the flatness of the film, fine raw materials and complex surface treatment processes are usually needed, which not only increases the production cost, but also sacrifices the stiffness of the material. On the other hand, increasing the thickness of the material or using higher strength raw materials to improve the stiffness will also lead to a decrease in flatness.

[0005] Therefore, how to prepare a polyester film with excellent stiffness and flatness is a key technical difficulty. SUMMARY

[0006] In order to solve the problem that the polyester film in the prior art cannot have excellent flatness while also having excellent stiffness, the present application discloses a MLCC release film base film, which introduces a special polyester chip prepared by a specific method and a modified master batch, so that the prepared MLCC release film base film has excellent stiffness, flatness and dimensional stability. In addition, the present application introduces a nucleating agent in the synthesis process of the special polyester chip, which not only enhances the mechanical properties of the film, but also ensures its stability in high temperature environment, meeting the requirements of high-end MLCC release film.

[0007] The technical scheme adopted by the present application to solve its technical problems is:

[0008] An MLCC release film base film, which is an ABC three-layer co-extrusion structure, wherein the A and C layers are surface layers, and the B layer is a core layer;

[0009] The material of the A layer comprises the following components in parts by weight:

[0010] Special polyester chips 70-95 parts;

[0011] Modified masterbatch 5-30 parts;

[0012] The material of the B layer comprises the following components in parts by weight:

[0013] Special polyester chips 90-98 parts;

[0014] High-speed material 2-10 parts;

[0015] The material of the C layer comprises the following components in parts by weight:

[0016] Special polyester chips 50-80 parts;

[0017] Special masterbatch 20-50 parts;

[0018] The special polyester chips are prepared by esterification, polycondensation of a mixture of polyethylene terephthalate and polyethylene naphthalate and polyols, and adding a nucleating agent for extrusion granulation.

[0019] Optionally, the special polyester chips are prepared by the following method:

[0020] (1) Mix terephthalic acid and 2,6-naphthalene dicarboxylic acid in a container to obtain a mixture, then add ethylene glycol, a catalyst and a stabilizer, and react at 90-120°C for 2-4h under the protection of inert gas, then increase the temperature to 190-250°C and continue to react for 4-6h to complete the esterification reaction;

[0021] (2) Reduce the pressure to 10-60Pa while increasing the temperature to 240-265°C, and continue to react for 5-12h for polycondensation reaction, mix the obtained polycondensate and a nucleating agent, and prepare the special polyester chips by melt extrusion granulation.

[0022] Optionally, the mass ratio of the terephthalic acid and 2,6-naphthalene dicarboxylic acid is (1.5-9):1.

[0023] Optionally, the molar mass ratio of the mixture to ethylene glycol is 1:(1-1.1).

[0024] Optionally, the catalyst is added in an amount of (0.1-0.3)% of the total mass of the mixture; and the stabilizer is added in an amount of (0.02-0.2)% of the total mass of the mixture.

[0025] Optionally, the nucleating agent is an ethylene acrylic acid ionomer.

[0026] Optionally, the modified masterbatch is prepared by blending the opening agent filler and the special polyester chip, a dispersing agent, and then extruding and granulating by a double screw extruder.

[0027] Optionally, the particle size of the opening agent filler is 0.3-2.2 μm.

[0028] Optionally, the opening agent filler is added in an amount of (0.6-3)% of the mass of the special polyester chip.

[0029] Another object of the present application is to provide a preparation method of the MLCC release film base film as described above, characterized by comprising the following steps:

[0030] S1: according to the formula amount, sending the A layer, the B layer and the C layer to the extruder for melt extrusion;

[0031] S2: after passing through the die, the melt is cast on the chill roll to form a thick sheet, and after longitudinal stretching, transverse stretching, setting, cooling, traction and winding, the MLCC release film base film is obtained.

[0032] The present application has the following beneficial effects:

[0033] The MLCC release film base film provided by the present application uses special polyester chips as the polyester film base material, and combines with the modified masterbatch and the synergistic effect between the components, so that the prepared MLCC release film base film has excellent stiffness, flatness and dimensional stability, and also has lower roughness, meeting the requirements of the MLCC thinning release film base film; in addition, the nucleating agent is introduced in the synthesis process of the special polyester chip, which not only promotes the crystallization of the polyester, but also effectively prevents the degradation of the polyester at high temperature, so as to ensure the excellent mechanical properties of the polyester film, and also ensures the stability of the polyester film in high temperature environment. DETAILED DESCRIPTION

[0034] The present application will now be further described in detail. The examples described below are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application. Based on the examples of the present application, all other examples obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0035] In order to solve the problem that the polyester film in the prior art cannot realize excellent flatness while having excellent stiffness, the application provides an MLCC release film base film, and the MLCC release film base film is an ABC three-layer co-extrusion structure, wherein the A and C layers are face layers, and the B layer is a core layer.

[0036] The material of the A layer comprises the following components in parts by weight:

[0037] 70-95 parts of special polyester chips;

[0038] 5-30 parts of modified masterbatch;

[0039] The material of the B layer comprises the following components in parts by weight:

[0040] 90-98 parts of special polyester chips;

[0041] 2-10 parts of high-speed material;

[0042] The material of the C layer comprises the following components in parts by weight:

[0043] 50-80 parts of special polyester chips;

[0044] 20-50 parts of special masterbatch;

[0045] The special polyester chips are prepared by mixing polyethylene terephthalate and polyethylene naphthalate with polyols, esterification, polycondensation, and then adding a nucleating agent for extrusion granulation.

[0046] The MLCC release film base film provided by the application uses special polyester chips as the polyester film base material, and through the combination with modified masterbatch and the synergistic effect between the components, the prepared MLCC release film base film has excellent stiffness, flatness and dimensional stability, and also has lower roughness, meeting the requirements of the MLCC thin-layer release film base film; in addition, the nucleating agent is introduced in the synthesis process of the special polyester chips, which not only promotes the crystallization of the polyester, but also effectively prevents the degradation of the polyester at high temperature, so as to ensure the excellent mechanical properties of the polyester film and also ensure its stability in a high-temperature environment.

[0047] Specifically, in order to further improve the processing stability of the film during high-speed production, the high-speed material is preferably at least one selected from the group consisting of Yizheng Chemical Fiber FG6200 and Zhuben Oil S-626.

[0048] In order to improve the optical performance and opening property of the film, the special masterbatch is preferably at least one selected from the group consisting of Yizheng Chemical Fiber FG611, Yizheng Chemical Fiber FG616, Zhuben Oil X-006 and Fushu 171-2.

[0049] The special polyester chip is preferably prepared according to the following method.

[0050] (1) mixing terephthalic acid and 2,6-naphthalene dicarboxylic acid in a container to obtain a mixture, then adding ethylene glycol, a catalyst and a stabilizer, and reacting under the protection of inert gas at 90-120 DEG C for 2-4 h, increasing the temperature to 190-250 DEG C, and continuing to react for 4-6 h to complete the esterification reaction;

[0051] (2) reducing the pressure to 10-60 Pa, increasing the temperature to 240-265 DEG C, and continuing to react for 5-12 h to complete the polycondensation reaction, mixing the obtained polycondensate and a nucleating agent, and granulating by melt extrusion to obtain the special polyester chip.

[0052] The special polyester chip is prepared by adding 2,6-naphthalene dicarboxylic acid which is similar in structure to terephthalic acid in the synthesis process, and the obtained special polyester chip has greater rigidity, and the addition of the ionomer nucleating agent can promote the crystallization of the polyester, avoid the degradation of the polyester at high temperature, ensure the mechanical properties of the polyester, and make the polyester film prepared from the special polyester chip have better stiffness, flatness and dimensional stability.

[0053] In order to further improve the comprehensive performance of the product, the mass ratio of terephthalic acid to 2,6-naphthalene dicarboxylic acid is preferably (1.5-9):1, wherein the content of 2,6-naphthalene dicarboxylic acid in the mixture is 10-40%.

[0054] The molar mass ratio of the mixture to ethylene glycol is preferably 1:(1-1.1), so as to ensure the balance and completeness of the reaction in the synthesis process of the polyester chip.

[0055] The catalyst is preferably prepared by mixing ethylene glycol antimony, butyl titanate and p-toluene sulfonic acid in a mass ratio of 1:1:(1.5-1.8); and the addition amount of the catalyst is preferably (0.1-0.3)% of the total mass of the mixture.

[0056] The stabilizer is preferably phosphite triphenyl ester; and the addition amount of the stabilizer is preferably (0.02-0.2)% of the total mass of the mixture.

[0057] The nucleating agent is preferably ethylene acrylic acid ionomer; further, the nucleating agent is preferably at least one selected from Surlyn resin of DuPont company and AClyn of Honeywell company.

[0058] Since the nucleating agent is wasted and unstable in excess, and the effect is not obvious in deficiency, the addition of the nucleating agent in proper proportion can greatly increase the crystal nucleus density, thereby effectively improving the optical performance of the film.

[0059] Preferably, the modified masterbatch is prepared by blending the opening agent filler and the special polyester chip and the dispersant, and then extruding and granulating by a double screw extruder.

[0060] Preferably, the opening agent filler is selected from at least one of silica, calcium carbonate, montmorillonite and barium sulfate.

[0061] Preferably, the particle size of the opening agent filler is 0.3-2.2 microns.

[0062] Preferably, the addition amount of the opening agent filler is (0.6-3)% of the mass of the special polyester chip.

[0063] Preferably, the dispersant is polyethylene glycol-20000; and preferably, the addition amount of the dispersant is (0.8-4.2)% of the mass of the special polyester chip.

[0064] The modified masterbatch prepared by the present application can avoid the uneven dispersion and aggregation of the opening filler by adding small particle size opening filler and uniformly dispersing the dispersant in the system, so that the polyester film prepared by using the modified masterbatch has lower roughness, and meets the requirements of the MLCC thin film separation film base film.

[0065] Another object of the present application is to provide a preparation method of the MLCC separation film base film as described above, comprising the following steps:

[0066] S1: according to the formula amount, the A layer, the B layer and the C layer are respectively dried in a drying tower at 170-185 DEG C for 3-5 hours, and then sent to a surface layer 1 extruder, a core layer extruder and a surface layer 2 extruder respectively after vacuumizing for melt extrusion;

[0067] S2: after passing through a three-layer co-extrusion die head, the melt is cast onto a casting roll at 18-40 DEG C to form a casting sheet; the casting sheet is preheated to 78-90 DEG C by a longitudinal preheating roller, and then instantaneously heated to 100-120 DEG C by an infrared lamp tube, and then stretched by 2.8-4.3 times in the longitudinal direction, and then rapidly cooled by a cooling roller at 25-35 DEG C to form a unidirectional sheet; the unidirectional sheet is preheated to 100-120 DEG C, stretched by 3.8-4.7 times in the transverse direction at 125-135 DEG C, and then cooled at 50-180 DEG C after being shaped at 235-245 DEG C for 10-30 seconds, and then wound by traction to obtain the MLCC separation film base film.

[0068] The application provides a preparation method of an MLCC release film base film.

[0069] In order to make the above-mentioned purposes, features and advantages of the application more obvious and easy to understand, the specific embodiments of the application are described in detail below.

[0070] Unless otherwise specified, the high-speed material in each embodiment and the comparative example of the application is FG6200 of Yizheng Chemical Fibre; the special masterbatch is FG611 of Yizheng Chemical Fibre; the stabilizer is triphenyl phosphite; the catalyst is a mixture of ethylene glycol antimony, butyl titanate and p-toluene sulfonic acid in a mass ratio of 1:1:1.8; the nucleating agent is Surlyn resin of DuPont; the opening agent filler is silicon dioxide with a particle size of 0.3-2.2 microns; the dispersing agent is polyethylene glycol-20000; and the amount of the material in each embodiment and the comparative example is calculated by weight fraction.

[0071] An MLCC release film base film has an ABC three-layer co-extrusion structure, wherein the A and C layers are face layers, and the B layer is a core layer.

[0072] The material of the A layer comprises the following components by weight fraction:

[0073] 70 parts of special polyester chips;

[0074] 30 parts of modified masterbatch;

[0075] The material of the B layer comprises the following components by weight fraction:

[0076] 90 parts of special polyester chips;

[0077] 10 parts of high-speed material;

[0078] The material of the C layer comprises the following components by weight fraction:

[0079] 50 parts of special polyester chips;

[0080] 50 parts of special masterbatch;

[0081] The special polyester chips are prepared by the following method:

[0082] (1) terephthalic acid and 2,6-naphthalene dicarboxylic acid are mixed in a container to obtain a mixture, then ethylene glycol, a catalyst and a stabilizer are added, and the mixture is reacted at 90℃ for 2h under inert gas protection, the temperature is increased to 190℃, and the reaction is continued for 4h to complete the esterification reaction;

[0083] (2) the pressure is reduced to 10Pa, and the temperature is increased to 240℃, and the polycondensation reaction is continued for 5h, then the obtained polycondensate and a nucleating agent are mixed, and the mixture is granulated by melt extrusion to obtain the special polyester chip.

[0084] Specifically, the mass ratio of terephthalic acid to 2,6-naphthalene dicarboxylic acid is 1.5:1; the molar mass ratio of the mixture to ethylene glycol is 1:1; the addition amount of the catalyst is 0.1% of the total mass of the mixture; the addition amount of the stabilizer is 0.02% of the total mass of the mixture; and the addition amount of the nucleating agent is 0.5% of the mass of the polycondensate.

[0085] The modified masterbatch is prepared by the following method:

[0086] (1) the opening agent filler, the dispersing agent and the special polyester chip are added into a high-speed mixer for preliminary mixing, the rotation speed of the high-speed mixer is set to 900rpm, and the mixing is performed for 20min to obtain a preliminary mixed material;

[0087] (2) the preliminary mixed material is transferred to the feeding port of a twin-screw melt extruder, and is melt-extruded at 150℃, and then is granulated after cooling to obtain the modified masterbatch.

[0088] Specifically, the addition amount of the opening agent filler is 0.6% of the mass of the special polyester chip; and the addition amount of the dispersing agent is 0.8% of the mass of the special polyester chip.

[0089] The preparation method of the MLCC release film base film comprises the following steps:

[0090] S1: according to the formula amount, the A layer, the B layer and the C layer are dried in a drying tower at 170℃ for 3 hours, and then are sent to a surface layer 1 extruder, a core layer extruder and a surface layer 2 extruder respectively for melt extrusion after vacuumizing;

[0091] S2: the melt passes through a three-layer co-extrusion die head and is cast onto a casting roll at 18℃ to form a casting sheet; the casting sheet is preheated to 78℃ by a longitudinal preheating roller, is instantaneously heated to 100℃ by an infrared lamp tube, and then is stretched in the longitudinal direction by 2.8 times, and is rapidly cooled by a cooling roller at 25℃ after stretching to form a unidirectional sheet; the unidirectional sheet is preheated to 100℃, is stretched in the transverse direction by 3.8 times at 125℃, and is cooled at 50℃ after being shaped at 235℃ for 10 seconds, and is obtained by traction and winding to obtain the MLCC release film base film.

[0092] The MLCC release film base film is an ABC three-layer co-extrusion structure, wherein A and C layers are surface layers, and B layer is a core layer;

[0093] The material of the A layer comprises the following components in parts by weight:

[0094] Special polyester chips 95 parts;

[0095] Modified masterbatch 5 parts;

[0096] The material of the B layer comprises the following components in parts by weight:

[0097] Special polyester chips 98 parts;

[0098] High-speed material 2 parts;

[0099] The material of the C layer comprises the following components in parts by weight:

[0100] Special polyester chips 80 parts;

[0101] Special masterbatch 20 parts;

[0102] The special polyester chips are prepared by the following method:

[0103] (1) In a container, terephthalic acid and 2,6-naphthalene dicarboxylic acid are mixed to obtain a mixture, then ethylene glycol, a catalyst and a stabilizer are added, and under the protection of inert gas, the reaction is carried out at 120℃ for 4h, the temperature is increased to 250℃, and the reaction is continued for 6h to complete the esterification reaction;

[0104] (2) The pressure is reduced to 160Pa, and at the same time, the temperature is increased to 265℃, and the polycondensation reaction is continued for 12h, then the obtained polycondensate and a nucleating agent are mixed, and the mixture is granulated by melt extrusion to obtain the special polyester chips.

[0105] Specifically, the mass ratio of terephthalic acid to 2,6-naphthalene dicarboxylic acid is 9:1; the molar mass ratio of the mixture to ethylene glycol is 1:1.1; the addition amount of the catalyst is 0.3% of the total mass of the mixture; the addition amount of the stabilizer is 0.2% of the total mass of the mixture; and the addition amount of the nucleating agent is 1.8% of the mass of the polycondensate.

[0106] The modified masterbatch is prepared by the following method:

[0107] (1) The opening agent filler, the dispersant and the special polyester chips are added into a high-speed mixer for preliminary mixing, the rotation speed of the high-speed mixer is set to 1000rpm, and the mixing is carried out for 30min to obtain a preliminary mixed material;

[0108] (2) The preliminary mixed material is transferred to the feeding port of a twin-screw melt extruder, and is melt-extruded at 270℃, and then is granulated after cooling to obtain the modified masterbatch.

[0109] Specifically, the additive amount of the opening agent filler is 3% of the mass of the special polyester chip; and the additive amount of the dispersant is 4.2% of the mass of the special polyester chip.

[0110] The preparation method of the MLCC release film base film comprises the following steps:

[0111] S1: According to the formula amount, the A layer, the B layer and the C layer are dried in a drying tower at 185℃ for 5 hours, and then sent to a surface layer 1 extruder, a core layer extruder and a surface layer 2 extruder respectively after vacuumizing for melt extrusion;

[0112] S2: After passing through a three-layer co-extrusion die head, the melt is cast onto a 40℃ casting roll to form a casting sheet; the casting sheet is preheated to 90℃ by a longitudinal preheating roller, instantaneously heated to 120℃ by an infrared lamp tube, and then stretched by 4.3 times in the longitudinal direction, and then rapidly cooled by a 35℃ cooling roller to form a unidirectional sheet; the unidirectional sheet is preheated to 120℃, stretched by 4.7 times in the transverse direction at 135℃, and then cooled at 180℃ after being shaped at 245℃ for 30 seconds, and then wound by traction to obtain the MLCC release film base film.

[0113] The MLCC release film base film is of an ABC three-layer co-extrusion structure, wherein the A layer and the C layer are surface layers, and the B layer is a core layer.

[0114] The material of the A layer comprises the following components in parts by weight:

[0115] Special polyester chip 80 parts;

[0116] Modified masterbatch 20 parts;

[0117] The material of the B layer comprises the following components in parts by weight:

[0118] Special polyester chip 95 parts;

[0119] High-speed material 5 parts;

[0120] The material of the C layer comprises the following components in parts by weight:

[0121] Special polyester chip 60 parts;

[0122] Special masterbatch 40 parts;

[0123] The special polyester chip is prepared by the following method:

[0124] (1) In a container, terephthalic acid and 2,6-naphthalene dicarboxylic acid are mixed to obtain a mixture, and then ethylene glycol, a catalyst and a stabilizer are added, and under the protection of inert gas, the reaction is carried out at 100℃ for 3h, and then the temperature is increased to 230℃, and the reaction is continued for 5h to complete the esterification reaction;

[0125] (2) The pressure was reduced to 30 Pa, and the temperature was increased to 250°C. The polycondensation reaction was continued for 8 hours. The obtained polycondensate was mixed with a nucleating agent, and granulated by melt extrusion to obtain special polyester chips.

[0126] Specifically, the mass ratio of terephthalic acid to 2,6-naphthalene dicarboxylic acid is 5:1; the molar mass ratio of the mixture to ethylene glycol is 1:1; the amount of catalyst added is 0.2% of the total mass of the mixture; the amount of stabilizer added is 0.1% of the total mass of the mixture; and the amount of nucleating agent added is 1% of the mass of the polycondensate.

[0127] The modified masterbatch was prepared as follows:

[0128] (1) Add the anti-blocking agent filler, dispersant and special polyester chips into a high-speed mixer for preliminary mixing. The speed of the high-speed mixer is set to 950 rpm and mixed for 25 minutes to obtain a preliminary mixture;

[0129] (2) The preliminary mixed material is transferred to the feeding port of a twin-screw melt extruder, melted and extruded at 200°C, and granulated after cooling to obtain a modified masterbatch.

[0130] Specifically, the addition amount of the anti-blocking agent filler is 2% of the mass of the special polyester chips; the addition amount of the dispersant is 3% of the mass of the special polyester chips.

[0131] The method for preparing the MLCC release film base film comprises the following steps:

[0132] S1: According to the formula, layer A, layer B, and layer C are dried in a drying tower at 180°C for 4 hours, and then vacuumed and sent to the surface layer 1 extruder, core layer extruder, and surface layer 2 extruder for melt extrusion;

[0133] S2: After passing through the three-layer co-extrusion die, the melt is cast onto a casting roll at 30°C to form a casting sheet; the casting sheet is preheated to 85°C by a longitudinal preheating roll, instantly heated to 110°C by an infrared lamp, and then stretched 3.5 times longitudinally. After stretching, it is quickly cooled by a cooling roll at 30°C to form a unidirectional sheet; the unidirectional sheet is preheated at 110°C, stretched 4.2 times transversely at 130°C, and fixed at 240°C for 20 seconds and then cooled at 100°C. After traction and winding, the MLCC release film base film is obtained.

[0134] An MLCC release film base film, which is an ABC three-layer co-extrusion structure, wherein layers A and C are surface layers, and layer B is a core layer;

[0135] The materials of layer A include the following components in parts by weight:

[0136] 85 portions of special polyester chips;

[0137] Modified masterbatch 15 parts;

[0138] The material of B layer includes the following components in parts by weight:

[0139] Special polyester chip 96 parts;

[0140] High-speed material 4 parts;

[0141] The material of C layer includes the following components in parts by weight:

[0142] Special polyester chip 70 parts;

[0143] Special masterbatch 30 parts;

[0144] The special polyester chip is prepared by the following method:

[0145] (1) In a container, terephthalic acid and 2,6-naphthalene dicarboxylic acid are mixed to obtain a mixture, then ethylene glycol, a catalyst and a stabilizer are added, and under the protection of inert gas, the reaction is carried out at 110℃ for 2h, the temperature is increased to 190℃, and the reaction is continued for 5h to complete the esterification reaction;

[0146] (2) The pressure is reduced to 40Pa, and at the same time the temperature is increased to 240℃, and the polycondensation reaction is continued for 10h, then the obtained polycondensate and nucleating agent are mixed, and the special polyester chip is prepared by melt extrusion granulation.

[0147] Specifically, the mass ratio of terephthalic acid to 2,6-naphthalene dicarboxylic acid is 8:1; the molar mass ratio of the mixture to ethylene glycol is 1:1; the addition amount of the catalyst is 0.3% of the total mass of the mixture; the addition amount of the stabilizer is 0.2% of the total mass of the mixture; and the addition amount of the nucleating agent is 1.5% of the mass of the polycondensate.

[0148] The modified masterbatch is prepared by the following method:

[0149] (1) The opening agent filler, dispersant and special polyester chip are added to a high-speed mixer for preliminary mixing, the rotation speed of the high-speed mixer is set to 900rpm, and the mixing is carried out for 30min to obtain a preliminary mixed material;

[0150] (2) The preliminary mixed material is transferred to the feeding port of a twin-screw melt extruder and is fed in, and is melt extruded at 270℃, and is granulated after cooling to obtain the modified masterbatch.

[0151] The modified masterbatch is prepared by the following method: The opening agent filler and the special polyester chip, dispersant are blended, and are extruded and granulated by a twin-screw extruder.

[0152] Specifically, the addition amount of the opening agent filler is 1% of the mass of the special polyester chip; and the addition amount of the dispersant is 1% of the mass of the special polyester chip.

[0153] The preparation method of the MLCC release film base film comprises the following steps:

[0154] S1: According to the formula amount, the A layer, the B layer and the C layer are dried in a drying tower at 170-185℃ for 3 hours, and then sent to a surface layer 1 extruder, a core layer extruder and a surface layer 2 extruder respectively after vacuumizing for melt extrusion;

[0155] S2: After passing through a three-layer co-extrusion die head, the melt is cast onto a 18℃ casting roll to form a casting sheet; the casting sheet is preheated to 90℃ by a longitudinal preheating roller, instantaneously heated to 110℃ by an infrared lamp tube, and then subjected to 3 times longitudinal stretching, and after stretching, it is rapidly cooled by a 30℃ cooling roller to form a unidirectional sheet; the unidirectional sheet is preheated to 120℃, stretched in the transverse direction by 3.8 times at 135℃, and then cooled at 50℃ after being shaped at 235℃ for 30 seconds, and finally wound up by traction to obtain the MLCC release film base film.

[0156] Comparative Example 1

[0157] The MLCC release film base film is a three-layer co-extrusion structure, wherein the A layer and the C layer are surface layers, and the B layer is a core layer.

[0158] The material of the A layer comprises the following components by weight fraction:

[0159] FG600 base film grade polyester chip 70 parts;

[0160] Nucleating agent 2 parts;

[0161] Modified masterbatch 30 parts;

[0162] The material of the B layer comprises the following components by weight fraction:

[0163] FG600 base film grade polyester chip 90 parts;

[0164] High-speed material 10 parts;

[0165] The material of the C layer comprises the following components by weight fraction:

[0166] FG600 base film grade polyester chip 50 parts;

[0167] Special masterbatch 50 parts;

[0168] The modified masterbatch is prepared as follows:

[0169] (1) The opening agent filler, dispersant and special polyester chip are added to a high-speed mixer for preliminary mixing, the speed of the high-speed mixer is set to 900 rpm, and the mixing time is 20 min to obtain a preliminary mixed material;

[0170] (2) The preliminary mixture is transferred to the feeding port of a twin-screw melting extruder, melted and extruded at 150 DEG C, and granulated after cooling to obtain the modified masterbatch.

[0171] Specifically, the addition amount of the opening agent filler is 0.6% of the mass of the FG600 base film-grade polyester chip, and the addition amount of the dispersant is 0.8% of the mass of the FG600 base film-grade polyester chip.

[0172] The preparation method of the MLCC release film base film includes the following steps:

[0173] S1: According to the formula amount, the A layer, the B layer and the C layer are dried in a drying tower at 170 DEG C for 3 hours, and then sent to a surface layer 1 extruder, a core layer extruder and a surface layer 2 extruder respectively after vacuumizing for melting extrusion;

[0174] S2: After passing through a three-layer co-extrusion die head, the melt is cast onto a 18 DEG C casting roll to form a casting sheet; the casting sheet is preheated to 78 DEG C by a longitudinal preheating roller, instantaneously heated to 100 DEG C by an infrared lamp tube, and then stretched by 2.8 times in the longitudinal direction, and then rapidly cooled by a 25 DEG C cooling roller to form a unidirectional sheet; the unidirectional sheet is preheated to 100 DEG C, stretched by 3.8 times in the transverse direction at 125 DEG C, and then cooled at 50 DEG C after being shaped at 235 DEG C for 10 seconds, and then wound by traction to obtain the MLCC release film base film.

[0175] Comparative Example 2

[0176] The comparative example is the same as example 1, except that the material of the A layer in the comparative example 2 comprises the following components by weight fraction:

[0177] Special polyester chip 60 parts;

[0178] Modified masterbatch 30 parts.

[0179] Comparative Example 3

[0180] The comparative example is the same as example 1, except that the material of the A layer in the comparative example 3 comprises the following components by weight fraction:

[0181] Special polyester chip 98 parts;

[0182] Modified masterbatch 30 parts.

[0183] Comparative Example 4

[0184] The comparative example is the same as example 1, except that the mass ratio of terephthalic acid to 2,6-naphthalene dicarboxylic acid in the preparation process of the special polyester chip in the comparative example 4 is 19:1, i.e. 2,6-naphthalene dicarboxylic acid accounts for 5% of the mass of the mixture.

[0185] Comparative Example 5

[0186] The comparative example is the same as example 1, except that the mass ratio of terephthalic acid and 2,6-naphthalene dicarboxylic acid in the preparation process of the special polyester chip in comparative example 5 is 1.5:0, i.e. no 2,6-naphthalene dicarboxylic acid is added.

[0187] Comparative example 6

[0188] The comparative example is the same as example 1, except that the material of the A layer in comparative example 6 is not modified masterbatch.

[0189] Comparative example 7

[0190] The comparative example is the same as example 1, except that the material of the A layer in comparative example 7 includes the following components in terms of weight fraction:

[0191] Special polyester chip 70 parts;

[0192] Modified masterbatch 3 parts.

[0193] Comparative example 8

[0194] The comparative example is the same as example 1, except that the material of the A layer in comparative example 8 includes the following components in terms of weight fraction:

[0195] Special polyester chip 70 parts;

[0196] Modified masterbatch 35 parts.

[0197] Comparative example 9

[0198] The comparative example is the same as example 1, except that the modified masterbatch in comparative example 9 is prepared as follows:

[0199] (1) Add 1820 parts of terephthalic acid, 30 parts of nano inorganic dispersion liquid, 680 parts of ethylene glycol, 1 part of stabilizer, and 1 part of catalyst into a reactor, and raise the temperature of the reactor to 235°C under nitrogen protection, melt for 100 min at constant temperature;

[0200] (2) After the materials in step (1) are melted, raise the temperature in the reactor to 290°C, and react for 60 min at constant temperature; then reduce the pressure in the reactor to 10 Pa, raise the temperature in the reactor to 340°C, and react for 120 min at constant temperature. After the reaction is completed, remove small molecular impurities by distillation during the reaction, and finally obtain the modified masterbatch by melt extrusion and granulation.

[0201] Among them, the inorganic dispersion liquid is prepared according to the following steps in terms of weight fraction:

[0202] Disperse 100 parts of the opening agent filler, 2 parts of dispersant, 700 parts of ethylene glycol in a high-speed mixer at a speed of 1200 rpm for 60 minutes to obtain an inorganic dispersion liquid.

[0203] Comparative Example 10

[0204] This comparative example is the same as Example 1, except that the nucleating agent is Surlyn 8920 from DuPont.

[0205] Comparative Example 11

[0206] This comparative example is the same as Example 1, except that the opening agent filler is silica with a particle size of 20-100 nm.

[0207] The measured values shown in the various examples and comparative examples of the present application were measured according to the following methods.

[0208] Stiffness: After slitting, take a 2.5 cm wide and 20 cm long sample from each station, place the sample on a horizontal marble table in an environment of 23±2℃ and 50±5% relative humidity, with the sample extending 10 cm out of the table, measure the vertical height of the sample hanging down with a measuring ruler, the smaller the vertical height of the sample hanging down, the higher the stiffness of the sample. Measure the vertical height of all samples in turn, in units of 1 mm, and take the average value as the stiffness value.

[0209] Warpage height: After slitting, take a 100 cm long film sample from each station, place it on a horizontal marble table in an environment of 23±2℃ and 50±5% relative humidity, observe the most severe warpage position and cut a 60 cm*60 cm warpage sample, place the sample with the warpage surface facing up on the test platform, measure the height of the warpage of the four edges of the sample with a measuring ruler, the height is the highest height of the edge, in units of 1 mm, measure the warpage data of all samples in turn, and take the maximum value as the warpage value.

[0210] Heat crimping: After slitting, take a 100 cm long film sample from each station, place it on a horizontal marble table in an environment of 23±2℃ and 50±5% relative humidity, and observe whether the film surface has a wavy concave-convex shape.

[0211] Heat shrinkage: Use VMC322 secondary dimensional shrinkage tester from Nantong Taizhen Precision Instrument Co., Ltd. to test according to the method specified in GB / T13542.2.

[0212] Roughness: Use SE800 surface roughness meter from Japan Kosaka Research Institute to test according to the method specified in GB / T 1031-2009.

[0213] Friction coefficient: The MXD-02 friction coefficient instrument of Jinan Languang Mechanical and Electrical Technology Co., Ltd. was used to test according to the method specified in GB / T 10006-2021.

[0214] Mechanical properties: The elongation at break and elastic modulus were tested using the C610M intelligent electronic tensile testing machine of Jinan Languang Mechanical and Electrical Technology Co., Ltd. according to the method specified in ASTM D882-18.

[0215] The properties of the MLCC release film base film in the embodiments and the comparative examples of the present application are shown in Table 1.

[0216]

[0217] The difference between Comparative Example 1 and Example 1 is that the special polyester chip in Example 1 is replaced by FG600 base film grade polyester chip. Although a nucleating agent is also added, the stiffness and dimensional stability of the prepared MLCC release film base film are poor, the film surface is warped and heat wrinkled, and the elastic modulus is greatly reduced.

[0218] The difference between Comparative Example 2, Comparative Example 3 and Example 1 is that the addition amount of the special polyester chip is reduced in Comparative Example 2, the stiffness and dimensional stability of the prepared MLCC release film base film are poor, the film surface is warped, and the elastic modulus is reduced; the addition amount of the special polyester chip is increased in Comparative Example 3, the elongation at break of the prepared MLCC release film base film is significantly reduced, the film is easy to break, and the production film-forming property and subsequent processing stability are affected.

[0219] The difference between Comparative Example 4 and Example 1 is that the mass ratio of terephthalic acid to 2,6-naphthalene dicarboxylic acid in the preparation process of the special polyester chip in Comparative Example 4 is 19:1, i.e. 2,6-naphthalene dicarboxylic acid accounts for 5% of the total mass, the stiffness and dimensional stability of the prepared MLCC release film base film are poor, the film surface is warped and heat wrinkled, and the elastic modulus is greatly reduced.

[0220] The difference between Comparative Example 5 and Example 1 is that 2,6-naphthalene dicarboxylic acid is not added in the preparation process of the special polyester chip in Comparative Example 5, the stiffness and dimensional stability of the prepared MLCC release film base film are poor, the film surface is warped and heat wrinkled, and the elastic modulus is greatly reduced.

[0221] The difference between Comparative Example 6 and Example 1 is that the material of layer A in Comparative Example 6 does not have a modified master batch, the friction coefficient of the prepared MLCC release film base film is too large, which causes the film to stick together during production, and normal production cannot be carried out.

[0222] The difference between Comparative Example 7, Comparative Example 8 and Example 1 is that the addition amount of the modified masterbatch is reduced in Comparative Example 7, the friction coefficient of the MLCC release film base film prepared is large, the film is adhered in the production process, and the production stability is affected; the addition amount of the modified masterbatch is increased in Comparative Example 8, the roughness of the MLCC release film base film prepared is large, and the use requirement of the MLCC release film base film cannot be met.

[0223] The difference between Comparative Example 9 and Example 1 is that the preparation method of the modified masterbatch is changed, the roughness of the MLCC release film base film prepared is large, the use requirement of the MLCC release film base film cannot be met, and the friction coefficient is large, and the production stability is affected.

[0224] The difference between Comparative Example 10 and Example 1 is that the nucleating agent is Surlyn 8920 of DuPont Company, the MLCC release film base film prepared has warping and thermal wrinkling on the film surface, the stiffness and the dimensional stability are reduced, and the mechanical properties are poor.

[0225] The difference between Comparative Example 11 and Example 1 is that the opening agent filler is silica with a particle size of 20-100 nm, the friction coefficient of the MLCC release film base film prepared is too large, the film is adhered in the production process, and normal production cannot be carried out.

[0226] From the above data, it can be seen that, by using the special polyester chip as the polyester film base material, and through the combination with the modified masterbatch and the synergistic effect between the components, the MLCC release film base film prepared has excellent stiffness, flatness and dimensional stability, and also has lower roughness, and meets the requirements of the MLCC thin-layer release film base film.

[0227] Based on the above ideal embodiments according to the application, through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the application. The technical scope of the application is not limited to the content in the specification, and the technical scope must be determined according to the scope of claims.

Claims

1. An MLCC release film base film, characterized in that: The MLCC release film base film is an ABC three-layer co-extrusion structure, wherein layers A and C are surface layers, and layer B is the core layer; The materials of the A layer include the following components in parts by weight: Special polyester chips 70-95 parts; 5-30 parts of modified masterbatch; The materials of the B layer include the following components in parts by weight: 90-98 pieces of special polyester chips; 2-10 servings of high-speed material; The materials of the C layer include the following components in parts by weight: 50-80 pieces of special polyester chips; Special masterbatch 20-50 parts; The high-speed material is selected from at least one of Yizheng Chemical Fiber FG6200 and Takemoto Grease S-626; the special masterbatch is selected from at least one of Yizheng Chemical Fiber FG611, Yizheng Chemical Fiber FG616, Takemoto Grease X-006, and Fosu 171-2; The special polyester chips are prepared as follows: (1) Terephthalic acid and 2,6-naphthalenedicarboxylic acid are mixed in a container to obtain a mixture, and then ethylene glycol, a catalyst, and a stabilizer are added. Under the protection of an inert gas, the mixture is reacted at 90-120°C for 2-4 hours, and the temperature is raised to 190-250°C and the reaction is continued for 4-6 hours to complete the esterification reaction; (2) reducing the pressure to 10-60 Pa and simultaneously increasing the temperature to 240-265°C, continuing the polycondensation reaction for 5-12 hours, mixing the obtained polycondensate with a nucleating agent, and granulating the mixture by melt extrusion to obtain special polyester chips; The mass ratio of terephthalic acid to 2,6-naphthalene dicarboxylic acid is (1.5-9):1; The catalyst is prepared by mixing antimony ethylene glycol, butyl titanate, and p-toluenesulfonic acid in a mass ratio of 1:1:(1.5-1.8); the amount of the catalyst added is (0.1-0.3)% of the total mass of the mixture; the stabilizer is triphenyl phosphite; the amount of the stabilizer added is (0.02-0.2)% of the total mass of the mixture; the nucleating agent is ethylene acrylic acid ionomer, and the nucleating agent is AClyn from Honeywell; The modified masterbatch is prepared by the following method: blending the anti-blocking agent filler with special polyester chips and dispersant, and then granulating the mixture by twin-screw extrusion; The opener filler is selected from at least one of silicon dioxide, calcium carbonate, montmorillonite, and barium sulfate; the particle size of the opener filler is 0.3-2.2 μm; the addition amount of the opener filler is (0.6-3)% of the mass of the special polyester chips; and the dispersant is polyethylene glycol-20000.

2. The MLCC release film base film according to claim 1, characterized in that The molar mass ratio of the mixture to ethylene glycol is 1:(1-1.1).

3. A method for preparing an MLCC release film base film according to claim 1 or 2, characterized in that: The following steps are involved: S1: According to the formula, layer A, layer B and layer C are sent to the extruder for melt extrusion; S2: After passing through the die head, the melt is cast behind the chilled roller to form a thick sheet. After longitudinal stretching, transverse stretching, shaping, cooling, pulling and winding, the MLCC release film base film is obtained.

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