Release film for ceramic capacitor and method for manufacturing the same

Abstract

The application discloses a release film for ceramic capacitors and a preparation method thereof, which comprises the following steps: 1) preparing a base material; 2) preparing raw materials; 3) preparing a mixed liquid; 4) coating; 5) removing bubbles; 6) solidifying; 7) preparing an oily release liquid; and 8) coating: coating the oily release liquid on the film product to form an oily release layer, thereby obtaining the release film for ceramic capacitors. The release film for ceramic capacitors adopts polytetrafluoroethylene glass varnished cloth or polytetrafluoroethylene high-temperature cloth as a base material layer and has the oily release layer, so that the product's temperature resistance can be effectively enhanced, the size stability is good, the shrinkage performance is low, the anti-adhesion performance and heat resistance are excellent, the flatness is good, the peeling effect is good, the problem that the release film cannot be torn after being adhered to the MLCC is avoided, and the production cost is low and the method is easy to implement.

Description

Technical Field

[0001] This invention relates to the field of release film technology, and in particular to a release film for ceramic capacitors and its preparation method. Background Technology

[0002] Multilayer ceramic chip capacitors (MLCCs) are commonly used electronic components and are widely applied in various circuits of electronic devices, such as oscillation, coupling, and filtering circuits. With the rapid development of electronic products in recent years, the application scenarios and usage of MLCCs have increased significantly, thus placing higher demands on their stability. Conventional multilayer ceramic chip capacitors typically employ a three-layer structure for their external electrodes: an external electrode coating layer, an electroplated layer, and a tin-plated layer. The Cu external electrode layer in this three-layer structure has relatively poor adhesion; to ensure adhesion, a certain amount of glass component needs to be added to the Cu paste.

[0003] In the release film market, most products use silicone oil as the release coating. However, with the expansion of market competition and the rise in the price of silicone oil raw materials, the release coating is becoming thinner and thinner, which increases the risk of uneven coating.

[0004] If the release coating has uneven application, after the outer electrode coating layer of the ceramic capacitor is bonded to the release film, under high temperature and pressure, the unevenly coated release film will adhere to the outer electrode coating layer. Forcibly tearing it apart can easily damage or crack the outer electrode coating layer. Increasing the thickness of the silicone oil coating on the release film to solve the adhesion problem leads to insufficient curing of the release film coating and increased costs. Furthermore, traditional PET or PVC films used as the base material for the release film have poor thermal stability; thermal shrinkage can cause localized unevenness, resulting in an uneven surface on the ceramic capacitor during the casting process. Summary of the Invention

[0005] To address the above shortcomings, the present invention aims to provide a low-cost, easy-to-peel, and stable release film for ceramic capacitors and its preparation method.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for preparing a release film for a ceramic capacitor includes the following steps:

[0008] (1) Prepare the substrate: Prepare polytetrafluoroethylene glass cloth or polytetrafluoroethylene high temperature cloth as the substrate layer, with a thickness of 40-250 μm preferred.

[0009] (2) Raw materials: The raw materials include the following components in the following weight ratios: 90-150 parts of fluorosilane compound, 900-1300 parts of organic solvent, 2-5 parts of coupling agent, 6-9 parts of metal catalyst, 10-30 parts of oily release agent, and 10-30 parts of paraffin wax.

[0010] (3) Preparation of mixed liquid: Fluorosilane compound and organic solvent are added to the reactor and stirred at a speed of 780-1000 rpm / min for 4-10 min; then a coupling agent is added and argon gas is introduced into the reactor to control the pressure at 2.0-2.8 MPa, and then the temperature is raised to 40-55℃ for 3-8 min; then a metal catalyst is added and argon gas is introduced into the reactor to control the pressure at 3.0-4.0 MPa, and the temperature is raised to 70-75℃ for 5-15 min to obtain mixed liquid;

[0011] (4) Coating 1: The mixed liquid is coated on the substrate layer, preferably by a micro-grooved roller, at a coating speed of 40-60m / min, to obtain a semi-finished product;

[0012] (5) Defoaming: The semi-finished product is transferred to a vacuum chamber for vacuuming. The vacuuming pressure is 80-90 kPa to promote the volatilization of organic solvents and prevent some solvents from not volatilizing in time during curing in a high-temperature oven, thus forming bubbles and improving smoothness.

[0013] (6) Curing: The semi-finished product after step (5) is transferred to an oven for drying and curing. The drying and curing temperature is 100-130 degrees Celsius and the curing time is 1-1.5 minutes to obtain a film product.

[0014] (7) Preparation of oily release liquid: Mix oily release agent and paraffin wax to obtain oily release liquid;

[0015] (8) Coating 2: Place the oily release liquid in a constant temperature bath, and set the temperature of the constant temperature bath to 50-70°C. Preferably, the oily release liquid is coated on the film product by a doctor blade coating method to form an oily release layer and obtain a release film for ceramic capacitors. The thickness of the oily release layer is preferably 1-5 μm.

[0016] Steps (1) and (2) have no order of priority, and steps (3) and (8) have no order of priority.

[0017] In a preferred embodiment of the present invention, the fluorosilane compound is one or a mixture of methyldifluorosilane, triethylfluorosilane, triphenylmethylfluorosilane, diphenyldifluorosilane, and di-tert-butyldifluorosilane. The organic solvent is propylene oxide, xylene, methyl ethyl ketone, or D30 organic solvent oil. The coupling agent is silane coupling agent NQ-62 or DL-102, or silane coupling agent SG-SI996. The metal catalyst is antimony glycolate or platinum catalyst.

[0018] A release film for ceramic capacitors is prepared using the above-mentioned method for preparing release films for ceramic capacitors.

[0019] The beneficial effects of this invention are as follows: This invention uses polytetrafluoroethylene (PTFE) glass cloth or PTFE high-temperature cloth as the substrate layer, replacing the original PET, PVC, or PE films, which effectively enhances the product's temperature resistance, dimensional stability, shrinkage, and anti-sticking properties. The use of paraffin wax and oil-based release agents has a synergistic effect, reducing the occurrence of adhesive film when bonded to ceramic capacitor composite materials. Simultaneously, during heating, it can separate the ceramic capacitors quickly without damaging the glass-containing outer electrode coating layer in the ceramic capacitor composite layer. The release film for ceramic capacitors prepared using the method of this invention has low shrinkage, excellent anti-adhesion properties and heat resistance, good flatness, and excellent peeling effect, effectively avoiding the problem of the release film being unable to be torn apart after adhesion to MLCCs. It has low production costs and is easy to implement. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the method steps of the present invention. Detailed Implementation

[0021] Example 1: See Figure 1 This invention provides a method for preparing a release film for ceramic capacitors, which includes the following steps:

[0022] (1) Prepare the substrate: Prepare polytetrafluoroethylene glass cloth as the substrate layer;

[0023] (2) Preparation of raw materials: The raw materials include the following components in the following weight ratios: 100 parts of fluorosilane compound, 950 parts of organic solvent, 2.5 parts of coupling agent, 7 parts of metal catalyst, 10 parts of oily release agent, and 20 parts of paraffin wax.

[0024] The fluorosilane compound is preferably a mixture of triphenylmethylfluorosilane and diphenyldifluorosilane in a 1:1 ratio. The organic solvent is preferably a mixture of propylene oxide, xylene, methyl ethyl ketone, and D30 organic solvent oil in a 2:1:3:1 ratio. The coupling agent is preferably silane coupling agent NQ-62. The metal catalyst is preferably antimony glycolate. The paraffin wax is preferably chlorinated wax.

[0025] (3) Preparation of mixed liquid: Fluorosilane compound and organic solvent are added to the reactor and stirred at a speed of 800 rpm / min for 6 min; then a coupling agent is added and argon gas is introduced into the reactor to control the pressure at 2.5 MPa. The temperature is then raised to 50°C and the reaction is carried out for 5 min; then a metal catalyst is added and argon gas is introduced into the reactor to control the pressure at 3.6 MPa. The temperature is then raised to 75°C and the reaction is carried out for 8 min to obtain the mixed liquid;

[0026] (4) Coating 1: The mixed liquid is coated onto the substrate layer by a micro-grooved roller at a speed of 50 m / min. At the same time, in order to prevent the local concentration of the liquid from being too high during the coating process, the mixed liquid needs to be continuously stirred at a speed of 550 rpm / min to obtain a semi-finished product.

[0027] (5) Defoaming: The semi-finished product is transferred to a vacuum chamber for vacuuming. The vacuuming pressure is 80-90 kPa to promote the volatilization of organic solvents and prevent some solvents from not volatilizing in time during curing in a high-temperature oven, thus forming bubbles and improving smoothness.

[0028] (6) Curing: The semi-finished product after step (5) is transferred to an oven for drying and curing. The drying and curing temperature is 100-130 degrees Celsius and the curing time is 1-1.5 minutes to obtain a film product.

[0029] (7) Preparation of oily release liquid: Mix oily release agent and paraffin wax to obtain oily release liquid;

[0030] (8) Coating 2: Place the oily release liquid in a constant temperature bath, and set the temperature of the constant temperature bath to 65°C. Preferably, use a scraper coating method to coat the oily release liquid onto the film product to form an oily release layer and obtain a release film for ceramic capacitors.

[0031] Example 2: This embodiment of the invention provides a method for preparing a release film for ceramic capacitors, which includes the following steps:

[0032] (1) Prepare the substrate: Prepare polytetrafluoroethylene high-temperature cloth as the substrate layer;

[0033] (2) Preparation of raw materials: The raw materials include the following components in the following weight ratios: 110 parts of fluorosilane compound, 900 parts of organic solvent, 2.4 parts of coupling agent, 6 parts of metal catalyst, 11 parts of oily release agent, and 19 parts of paraffin wax.

[0034] The fluorosilane compound is preferably a mixture of triphenylmethylfluorosilane and di-tert-butyldifluorosilane in a 1:1 ratio. The organic solvent is preferably a mixture of propylene oxide and xylene in a 2:1 ratio. The coupling agent is preferably DL-102 silane coupling agent. The metal catalyst is preferably a platinum catalyst. The paraffin wax is preferably an oxidized wax.

[0035] (3) Preparation of mixed liquid: Fluorosilane compound and organic solvent are added to the reactor and stirred at a speed of 900 rpm / min for 5 min; then a coupling agent is added and argon gas is introduced into the reactor to control the pressure at 2.6 MPa. The temperature is then raised to 52°C and the reaction is carried out for 4 min; then a metal catalyst is added and argon gas is introduced into the reactor to control the pressure at 3.5 MPa. The temperature is then raised to 72°C and the reaction is carried out for 9 min to obtain the mixed liquid;

[0036] (4) Coating 1: The mixed liquid is coated onto the substrate layer by a micro-grooved roller at a coating speed of 48m / min to obtain a semi-finished product;

[0037] (5) Defoaming: The semi-finished product is transferred to a vacuum chamber for vacuuming. The vacuuming pressure is 80-90 kPa.

[0038] (6) Curing: The semi-finished product after step (5) is transferred to an oven for drying and curing. The drying and curing temperature is 100-130 degrees Celsius and the curing time is 1-1.5 minutes to obtain a film product.

[0039] (7) Preparation of oily release liquid: Mix oily release agent and paraffin wax to obtain oily release liquid;

[0040] (8) Coating 2: Place the oily release liquid in a constant temperature bath. The temperature of the constant temperature bath is set to 64°C. Preferably, the oily release liquid is coated on the film product by a scraper coating method to form an oily release layer and obtain a release film for ceramic capacitors.

[0041] Example 3: This embodiment of the invention provides a method for preparing a release film for ceramic capacitors, which includes the following steps:

[0042] (1) Prepare the substrate: Prepare polytetrafluoroethylene high-temperature cloth as the substrate layer;

[0043] (2) Preparation of raw materials: The raw materials include the following components in the following weight ratios: 120 parts of fluorosilane compound, 1000 parts of organic solvent, 4 parts of coupling agent, 7 parts of metal catalyst, 15 parts of oily release agent, and 25 parts of paraffin wax.

[0044] The fluorosilane compound is preferably methyldifluorosilane. The organic solvent is preferably methyl butyl ketone. The coupling agent is preferably silane coupling agent SG-SI996. The metal catalyst is preferably antimony glycolate. The paraffin wax is preferably maleic anhydride wax.

[0045] (3) Preparation of mixed liquid: Fluorosilane compound and organic solvent are added to the reactor and stirred at a speed of 850 rpm / min for 9 min; then a coupling agent is added and argon gas is introduced into the reactor to control the pressure at 2.8 MPa. The temperature is then raised to 55°C and the reaction is carried out for 6 min; then a metal catalyst is added and argon gas is introduced into the reactor to control the pressure at 4.0 MPa. The temperature is then raised to 75°C and the reaction is carried out for 10 min to obtain the mixed liquid;

[0046] (4) Coating 1: The mixed liquid is coated onto the substrate layer by a micro-grooved roller at a coating speed of 60m / min to obtain a semi-finished product;

[0047] (5) Defoaming: The semi-finished product is transferred to a vacuum chamber for vacuuming. The vacuuming pressure is 80-90 kPa.

[0048] (6) Curing: The semi-finished product after step (5) is transferred to an oven for drying and curing. The drying and curing temperature is 100-130 degrees Celsius and the curing time is 1-1.5 minutes to obtain a film product.

[0049] (7) Preparation of oily release liquid: Mix oily release agent and paraffin wax to obtain oily release liquid;

[0050] (8) Coating 2: Place the oily release liquid in a constant temperature bath. The temperature of the constant temperature bath is set to 70°C. Preferably, the oily release liquid is coated on the film product by a scraper coating method to form an oily release layer and obtain a release film for ceramic capacitors.

[0051] Example 4: This embodiment of the invention provides a method for preparing a release film for ceramic capacitors, which includes the following steps:

[0052] (1) Prepare the substrate: Prepare polytetrafluoroethylene glass cloth as the substrate layer;

[0053] (2) Preparation of raw materials: The raw materials include the following components in the following weight ratios: 150 parts of fluorosilane compound, 1300 parts of organic solvent, 5 parts of coupling agent, 9 parts of metal catalyst, 28 parts of oily release agent, and 30 parts of paraffin wax.

[0054] The fluorosilane compound is preferably triethylfluorosilane. The organic solvent is preferably D30 solvent oil. The coupling agent is preferably silane coupling agent NQ-62. The metal catalyst is preferably a platinum catalyst. The paraffin wax is preferably chlorinated wax.

[0055] (3) Preparation of mixed liquid: Fluorosilane compound and organic solvent are added to the reactor and stirred at a speed of 1000 rpm / min for 8 min; then the coupling agent is added and argon gas is introduced into the reactor to control the pressure at 2.7 MPa. The temperature is then raised to 52°C and the reaction is carried out for 5 min; then the metal catalyst is added and argon gas is introduced into the reactor to control the pressure at 3.2 MPa. The temperature is then raised to 70°C and the reaction is carried out for 8 min to obtain the mixed liquid;

[0056] (4) Coating 1: The mixed liquid is coated onto the substrate layer by a micro-grooved roller at a coating speed of 50m / min to obtain a semi-finished product;

[0057] (5) Defoaming: The semi-finished product is transferred to a vacuum chamber for vacuuming. The vacuuming pressure is 80-90 kPa.

[0058] (6) Curing: The semi-finished product after step (5) is transferred to an oven for drying and curing. The drying and curing temperature is 100-130 degrees Celsius and the curing time is 1-1.5 minutes to obtain a film product.

[0059] (7) Preparation of oily release liquid: Mix oily release agent and paraffin wax to obtain oily release liquid;

[0060] (8) Coating 2: Place the oily release liquid in a constant temperature bath, and set the temperature of the constant temperature bath to 68°C. Preferably, use a scraper coating method to coat the oily release liquid onto the film product to form an oily release layer and obtain a release film for ceramic capacitors.

[0061] Example 5: This embodiment of the invention provides a method for preparing a release film for ceramic capacitors, which includes the following steps:

[0062] (1) Prepare the substrate: Prepare polytetrafluoroethylene glass cloth as the substrate layer;

[0063] (2) Preparation of raw materials: The raw materials include the following components in the following weight ratios: 140 parts of fluorosilane compound, 1200 parts of organic solvent, 4 parts of coupling agent, 8 parts of metal catalyst, 30 parts of oily release agent, and 25 parts of paraffin wax.

[0064] The fluorosilane compound is preferably di-tert-butyldifluorosilane. The organic solvent is preferably methyl methyl ethyl ketone. The coupling agent is preferably DL-102 silane coupling agent. The metal catalyst is preferably antimony glycolate. The paraffin wax is preferably oxidized wax.

[0065] (3) Preparation of mixed liquid: Fluorosilane compound and organic solvent are added to the reactor and stirred at a speed of 780 rpm / min for 7 min; then a coupling agent is added and argon gas is introduced into the reactor to control the pressure at 2.6 MPa. The temperature is then raised to 50 °C and the reaction is carried out for 4 min; then a metal catalyst is added and argon gas is introduced into the reactor to control the pressure at 3.1 MPa. The temperature is then raised to 72 °C and the reaction is carried out for 9 min to obtain the mixed liquid;

[0066] (4) Coating 1: The mixed liquid is coated onto the substrate layer by a micro-grooved roller at a coating speed of 52m / min to obtain a semi-finished product;

[0067] (5) Defoaming: The semi-finished product is transferred to a vacuum chamber for vacuuming. The vacuuming pressure is 80-90 kPa.

[0068] (6) Curing: The semi-finished product after step (5) is transferred to an oven for drying and curing. The drying and curing temperature is 100-130 degrees Celsius and the curing time is 1-1.5 minutes to obtain a film product.

[0069] (7) Preparation of oily release liquid: Mix oily release agent and paraffin wax to obtain oily release liquid;

[0070] (8) Coating 2: Place the oily release liquid in a constant temperature bath, and set the temperature of the constant temperature bath to 60°C. Preferably, use a scraper coating method to coat the oily release liquid onto the film product to form an oily release layer and obtain a release film for ceramic capacitors.

[0071] Example 6: This embodiment of the invention provides a method for preparing a release film for ceramic capacitors, which includes the following steps:

[0072] (1) Prepare the substrate: Prepare polytetrafluoroethylene high-temperature cloth as the substrate layer;

[0073] (2) Preparation of raw materials: The raw materials include the following components in the following weight ratios: 90 parts of fluorosilane compound, 900 parts of organic solvent, 2 parts of coupling agent, 6 parts of metal catalyst, 10 parts of oily release agent, and 10 parts of paraffin wax.

[0074] The fluorosilane compound is preferably a mixture of triphenylmethylfluorosilane and di-tert-butyldifluorosilane in a 1:1 ratio. The organic solvent is preferably a mixture of propylene oxide, xylene, methyl ethyl ketone, and D30 solvent oil in a 3:2:3:1 ratio. The coupling agent is preferably silane coupling agent NQ-62. The metal catalyst is preferably a platinum catalyst. The paraffin wax is preferably chlorinated wax.

[0075] (3) Preparation of mixed liquid: Fluorosilane compound and organic solvent are added to the reactor and stirred at a speed of 790 rpm / min for 5 min; then a coupling agent is added and argon gas is introduced into the reactor to control the pressure at 2.0 MPa. The temperature is then raised to 40°C and the reaction is carried out for 4 min; then a metal catalyst is added and argon gas is introduced into the reactor to control the pressure at 3.8 MPa. The temperature is then raised to 70°C and the reaction is carried out for 10 min to obtain the mixed liquid;

[0076] (4) Coating 1: The mixed liquid is coated onto the substrate layer by a micro-grooved roller at a coating speed of 40m / min to obtain a semi-finished product;

[0077] (5) Defoaming: The semi-finished product is transferred to a vacuum chamber for vacuuming. The vacuuming pressure is 80-90 kPa.

[0078] (6) Curing: The semi-finished product after step (5) is transferred to an oven for drying and curing. The drying and curing temperature is 100-130 degrees Celsius and the curing time is 1-1.5 minutes to obtain a film product.

[0079] (7) Preparation of oily release liquid: Mix oily release agent and paraffin wax to obtain oily release liquid;

[0080] (8) Coating 2: Place the oily release liquid in a constant temperature bath and set the temperature of the constant temperature bath to 50°C. Preferably, use a scraper coating method to coat the oily release liquid onto the film product to form an oily release layer and obtain a release film for ceramic capacitors.

[0081] The above embodiments are merely preferred embodiments of the present invention. The present invention cannot list all embodiments. Any technical solution that adopts one of the above embodiments, or any equivalent changes made based on the above embodiments, are within the protection scope of the present invention.

[0082] The following is a comparative test of the adhesive film used in the ceramic capacitor prepared in Example 1.

[0083] Principle: By bonding the release film of the ceramic capacitor of the present invention and the ordinary release film on the market to the ceramic capacitor composite film layer respectively, and then heating the defective products with sticky film to 50-60 degrees, it is observed whether the two can be separated.

[0084] S1: Take a release film sample (labeled A) of the present invention for ceramic capacitors with the same A4 size, release force, and thickness, and a commercially available release film sample (labeled B). To improve the accuracy of the test data, select three sets of samples for each, and label them A1, A2, A3 and B1, B2, B3 respectively.

[0085] S2: Under high temperature and certain pressure, samples A1, A2, A3 and samples B1, B2, B3 are respectively bonded to the ceramic capacitor composite film layer. After cooling, observe whether there is any adhesion. Place the composite samples with adhesion in an oven and heat to 50-60 degrees for 2 minutes.

[0086] S3: Observe whether the samples can be separated. Test the data of each group according to the above steps. See Table 1 for the data results.

[0087] Table 1

[0088]

[0089] As shown in Table 1, samples A1, A2, and A3 were easier to peel off after being bonded to the ceramic capacitor composite film layer compared to samples B1, B2, and B3. Specifically, after heating to 50°C, samples A1, A2, and A3 were able to separate naturally from the ceramic capacitor composite film layer, while samples B1, B2, and B3, after being bonded to the ceramic capacitor composite film layer, showed no significant change after heating to 50°C and remained difficult to peel off. Therefore, the release film product for ceramic capacitors of this invention represents a significant improvement in handling the adhesion problem, exhibiting excellent peeling performance.

[0090] Next, the temperature resistance and shrinkage performance of the release film for ceramic capacitors prepared in Example 1 were compared and tested:

[0091] ① Do not take the release film sample (marked as C) of the ceramic capacitor of this invention with the same A4 size, release force, and thickness as ordinary release film samples on the market (marked as D).

[0092] ② Divide the above samples into 3 groups, labeled C1, C2, C3 and D1, D2, D3 respectively. Use a standard measuring tape to measure their original width as 210mm and length as 297mm respectively.

[0093] ③ Divide the above samples into 3 groups and place them in a blower oven at a constant temperature of 160 degrees Celsius for 30 min, 1 h, and 2 h respectively. After baking, place them at room temperature and cool for 1 h. Then, use a standard measuring tape to measure the changes in their width and length. The widths are marked as C1W, C2W, C3W and D1W, D2W, D3W respectively, and the lengths are marked as C1L, C2L, C3L and D1L, D2L, D3L respectively.

[0094] ④ The shrinkage rate is calculated as follows: (original width or length - width or length changed during constant temperature baking) / original width or length * 100%. See Table 2 for specific data results.

[0095] Table 2

[0096]

[0097] As can be seen from the data in Table 2, samples C1, C2, and C3 were placed in a forced-air oven and baked at a constant temperature of 160 degrees Celsius for 30 minutes, 1 hour, and 2 hours respectively. After being placed at room temperature and cooled for 1 hour, their widths were measured using a standard measuring tape: C1W = 209.5 mm, C2W = 209.5 mm, and C3W = 209 mm. Their lengths were measured using a standard measuring tape: C1L = 297 mm, C2L = 297.3 mm, and C3L = 297.5 mm.

[0098] Samples D1, D2, and D3 were placed in a forced-air oven and baked at a constant temperature of 160 degrees Celsius for 30 minutes, 1 hour, and 2 hours respectively. After being placed at room temperature and cooled for 1 hour, their widths were measured using a standard measuring tape: D1W = 209 mm, D2W = 208.6 mm, and D3W = 208 mm. Their lengths were measured using a standard measuring tape: D1L = 298 mm, D2L = 298.5 mm, and D3L = 299 mm.

[0099] As shown in Table 2, with the increase in baking time at a constant temperature of 160 degrees Celsius, both width and length exhibited varying degrees of shrinkage or stretching. However, after 2 hours of baking at 160 degrees Celsius, the shrinkage rate of the width C3W of sample C3 was 0.4762%, while the shrinkage rate of the width D3W of sample D3 was 0.9524%, indicating that D3W shrank more severely than C3W. Simultaneously, after 2 hours of baking at 160 degrees Celsius, the shrinkage rate of the width C3L of sample C3 was -0.1684%, while the shrinkage rate of the width D3L of sample D3 was -0.6734%, indicating that D3L stretched more severely than C3L due to heat. Therefore, the release film for ceramic capacitors of this invention represents a significant improvement in product temperature resistance and shrinkage performance.

[0100] Based on the disclosure and teachings of the above specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on the present invention. Other membranes and preparation methods that are the same as or similar to those used are all within the protection scope of the present invention.

Claims

1. A method for preparing a release film for ceramic capacitors, comprising the following steps: (1) Prepare the substrate: Prepare polytetrafluoroethylene glass cloth or polytetrafluoroethylene high temperature cloth as the substrate layer; (2) Raw materials: The raw materials include the following components in the following weight ratios: 90-150 parts of fluorosilane compound, 900-1300 parts of organic solvent, 2-5 parts of coupling agent, 6-9 parts of metal catalyst, 10-30 parts of oily release agent, and 10-30 parts of paraffin wax. (3) Preparation of mixed liquid: Fluorosilane compound and organic solvent are added to the reactor and stirred; then a coupling agent is added, and argon gas is introduced into the reactor to control the pressure at 2.0-2.8 MPa, and then the temperature is raised to 40-55℃ to carry out the reaction; then a metal catalyst is added, and argon gas is introduced into the reactor to control the pressure at 3.0-4.0 MPa, and the temperature is raised to 70-75℃ to carry out the reaction to obtain a mixed liquid; (4) Coating 1: The mixed liquid is coated onto the substrate layer to obtain a semi-finished product; (5) Defoaming: The semi-finished product is transferred to a vacuum chamber for vacuuming to promote the volatilization of organic solvents; (6) Curing: The semi-finished product after step (5) is transferred to an oven for drying and curing to obtain a film product; (7) Preparation of oily release liquid: Mix oily release agent and paraffin wax to obtain oily release liquid; (8) Coating 2: Apply oily release liquid to the thin film product to form an oily release layer and obtain a release film for ceramic capacitors; Steps (1) and (2) have no specific order; The fluorosilane compound is one or a mixture of methyldifluorosilane, triethylfluorosilane, triphenylmethylfluorosilane, diphenyldifluorosilane, and di-tert-butyldifluorosilane; The organic solvent is propylene oxide, xylene, methyl ethyl ketone, or D30 organic solvent oil; The coupling agent is silane coupling agent NQ-62 or DL-102 silane coupling agent or silane coupling agent SG-SI996; The metal catalyst is either antimony glycolate or platinum catalyst.

2. The method for preparing a release film for ceramic capacitors according to claim 1, characterized in that, In step (3), fluorosilane compounds and organic solvents are added to the reaction vessel and stirred at a speed of 780-1000 rpm / min for 4-10 min. The reaction time after adding the coupling agent is 3-8 min, and the reaction time after adding the metal catalyst is 5-15 min.

3. The method for preparing a release film for ceramic capacitors according to claim 1, characterized in that, Step (4) The mixed liquid is coated onto the substrate layer using a micro-grooved roller at a speed of 40-60 m / min.

4. The method for preparing a release film for ceramic capacitors according to claim 1, characterized in that, The vacuum pressure in step (5) is 80-90 kPa; the drying and curing temperature in step (6) is 100-130 degrees Celsius, and the curing time is 1-1.5 min.

5. The method for preparing a release film for ceramic capacitors according to claim 1, characterized in that, In step (8), the oily release liquid is placed in a constant temperature bath, the temperature of which is set to 50-70°C. The oily release liquid is then applied to the film product using a scraper coating method.

6. A release film for ceramic capacitors, characterized in that, It is prepared by the method for preparing release film for ceramic capacitors as described in any one of claims 1-5.

Images