Multilayer ceramic capacitor (MLCC) release film based on a general substrate and a method of manufacturing the same

Abstract

The application discloses a kind of ordinary substrate MLCC release film based on, comprising: substrate layer, for un-electron ray PET substrate;Antistatic smoothing layer, at least one surface of substrate layer is arranged;Release layer, is arranged at the surface of antistatic smoothing layer away from substrate layer;The smoothing coating solution of antistatic smoothing layer includes epoxy resin, siloxane antistatic agent, first catalyst and first solvent, and the mass ratio of epoxy resin and siloxane antistatic agent is 1: (1-3) ;The release coating solution of release layer includes main agent silicone oil, crosslinking agent, anchor agent, second catalyst, hydroxyl modified silicone oil and second solvent.The ordinary substrate MLCC release film based on, the surface roughness of substrate is reduced by the antistatic smoothing layer of epoxy resin and siloxane antistatic agent compound, and the adhesion of release layer and substrate is improved;Release layer is optimized by hydroxyl modified silicone oil the release force stability and adhesion of the layer.

Description

Technical Field

[0001] This invention relates to the field of release film technology, specifically to a release film based on a common substrate MLCC and its preparation method. Background Technology

[0002] MLCC release film is a consumable that must be used in the production process of MLCC (multilayer ceramic capacitor). In the production process of MLCC, ceramic slurry needs to be coated on MLCC release film. After the product is dried and slit, it needs to be stacked in multiple layers. MLCC release film plays the role of supporting and protecting the surface in the whole production process.

[0003] The difference between MLCC release films and ordinary release films lies in the extremely high requirements for surface flatness. The surface height difference must be controlled within 500nm. Only release film products that meet this requirement can be used in MLCCs for electronic products. Electronic product MLCCs require small size and large capacitance, which requires the MLCC to be able to be stacked hundreds of times inside, which places extremely high demands on the surface flatness of the MLCC release film.

[0004] High-flatness MLCC-grade substrates are not only expensive but also require import. The low surface roughness of MLCC-grade substrates makes it difficult for the release coating to adhere and level, leading to adhesion issues after cutting and winding. Furthermore, damage to the release layer occurs during unwinding, resulting in unstable release force of the release film.

[0005] Therefore, how to produce high-flatness MLCC release films using ordinary grade PET substrates (i.e., surface roughness Ra > 40nm) is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0006] One of the objectives of this invention is to overcome the deficiencies in the prior art and provide a release film based on a common substrate MLCC, which reduces the surface roughness of the substrate and improves the adhesion between the release layer and the substrate by using an antistatic smoothing layer composed of epoxy resin and siloxane antistatic agent; the release layer optimizes the release force stability and adhesion of the layer by using hydroxyl-modified silicone oil.

[0007] To achieve the above-mentioned process effects, the technical solution of the present invention is: a release film based on a common substrate MLCC, comprising:

[0008] The substrate layer is a non-corona-treated PET substrate;

[0009] An antistatic smoothing layer is disposed on at least one surface of the substrate layer;

[0010] A release layer is disposed on the surface of the antistatic smooth layer away from the substrate layer;

[0011] The smoothing coating liquid of the antistatic smoothing layer includes epoxy resin, siloxane antistatic agent, first catalyst and first solvent, wherein the mass ratio of epoxy resin to siloxane antistatic agent is 1:(1-3).

[0012] The release coating liquid of the release layer includes a main silicone oil, a crosslinking agent, an anchoring agent, a second catalyst, hydroxyl-modified silicone oil, and a second solvent.

[0013] A preferred technical solution is as follows: The smoothing coating liquid comprises, by weight, 10 parts epoxy resin, 10-25 parts siloxane antistatic agent, 0.3-1 parts first catalyst, and 20-40 parts first solvent. Further, the smoothing coating liquid comprises 10 parts epoxy resin, 15-22 parts siloxane antistatic agent, 0.3-0.8 parts first catalyst, and 25-35 parts first solvent.

[0014] A preferred technical solution is as follows: the first solvent comprises toluene, methyl ethyl ketone (MEK), and cyclohexanone, wherein the mass ratio of toluene, MEK, and cyclohexanone is 1:1:(0.2–0.25). Further, the mass ratio of toluene, MEK, and cyclohexanone is 1:1:(0.2–0.24).

[0015] The preferred technical solution is: the siloxane antistatic agent is...

[0016] COLCOAT-N-103X, wherein the epoxy resin is Mitsubishi Bisphenol F type epoxy resin JER807.

[0017] A preferred technical solution is as follows: The release coating liquid of the release layer comprises, by weight, 100 parts of main silicone oil, 0.1-0.5 parts of crosslinking agent, 0.3-0.8 parts of anchoring agent, 1-2 parts of second catalyst, 0.1-0.5 parts of hydroxyl-modified silicone oil, and 2000-3000 parts of second solvent. Further, the release coating liquid of the release layer comprises 100 parts of main silicone oil, 0.1-0.3 parts of crosslinking agent, 0.3-0.6 parts of anchoring agent, 1-1.5 parts of second catalyst, 0.1-0.3 parts of hydroxyl-modified silicone oil, and 2300-2800 parts of second solvent.

[0018] The preferred technical solution is as follows: the main silicone oil is Dow Corning LTC-752, and the hydroxyl-modified silicone oil is Shin-Etsu X-22-343.

[0019] The preferred technical solution is that the second solvent includes toluene, butanone and n-heptane, and the mass ratio of toluene, butanone and n-heptane is (3-4):(8-10):(1-2).

[0020] A preferred technical solution is that the thickness of the antistatic smoothing layer is 0.4–0.8 μm. Further, the thickness of the antistatic smoothing layer is 0.4–0.6 μm.

[0021] The second objective of this invention is to overcome the deficiencies in the prior art and provide a method for preparing an MLCC release film, comprising the following steps:

[0022] S1: Prepare a smoothing coating solution and a release coating solution;

[0023] S2: The smoothing coating liquid is applied to at least one surface of the substrate layer and cured and dried for the first time. The continuous drying temperature is set to 90±5℃, 110±5℃, 110±5℃, 110±5℃, 110±5℃, 95±5℃ in sequence to obtain a blank film with an antistatic smoothing layer.

[0024] S3: The release coating liquid is applied to the surface of the antistatic smooth layer, and then cured and dried for the second time. The continuous drying temperature is set to 90±5℃, 115±5℃, 120±5℃, 120±5℃, 125±5℃, and 110±5℃ in sequence to obtain a film with a release layer.

[0025] S4: Curing the film to obtain an MLCC release film.

[0026] A preferred technical solution is that the curing temperature is 50–60°C. Further, the curing temperature is 53–57°C.

[0027] The advantages and beneficial effects of this invention are as follows:

[0028] This release film, based on ordinary substrate MLCC, reduces the surface roughness of the substrate and improves the adhesion between the release layer and the substrate through an antistatic smoothing layer.

[0029] The combination of epoxy resin and siloxane antistatic agent not only improves the smoothness of the substrate surface, but also facilitates the uniform distribution of the antistatic agent, thereby improving the antistatic stability and antistatic properties of the release film, while also improving the adhesion of the release layer.

[0030] The release coating solution optimizes the release force stability of the release film and improves the adhesion between the ceramic slurry and the release film in subsequent processes by using hydroxyl-modified silicone oil. Detailed Implementation

[0031] The specific embodiments of the present invention will be further described below with reference to examples. These examples are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0032] MLCC release film

[0033] The structure of MLCC release film consists of, from bottom to top, a stacked substrate layer, an antistatic smoothing layer, and a release layer.

[0034] Structure 2 of MLCC release film: Antistatic smoothing layers are provided on both sides of the substrate layer, and a release layer is provided on one surface of the antistatic smoothing layer. MLCC release film is a double-sided antistatic release film.

[0035] The structure of MLCC release film consists of three layers: from the inside out, a substrate layer, an antistatic smoothing layer, and a release layer. The antistatic smoothing layer and the release layer are symmetrically distributed on the two surfaces of the substrate layer. MLCC release film is an antistatic double-sided release film.

[0036] Substrate layer

[0037] The PET substrate is non-corona-treated, and further, the surface roughness of the PET substrate is 40 nm. The layer thickness of the PET substrate is 30 μm.

[0038] Antistatic smoothing layer

[0039] It is prepared by coating at least one surface of a substrate layer with a smoothing coating liquid, followed by curing and drying.

[0040] The smoothing coating liquid comprises epoxy resin, a siloxane antistatic agent, a first catalyst, and a first solvent. The epoxy resin accelerates the curing speed of the antistatic smoothing layer, shortens production time, improves efficiency, optimizes the leveling properties of the siloxane antistatic agent, and improves the surface roughness of the substrate. Excessive addition of epoxy resin to the smoothing coating liquid increases resistance, while insufficient addition leads to poor leveling properties and unsatisfactory surface roughness improvement in the resulting release film. Furthermore, the siloxane antistatic agent is COLCOAT-N-103X; the material contains water-absorbing substances, imparting antistatic properties to the material under 50% humidity. The material contains modified silica, resulting in good adhesion between the coated antistatic thin layer and the silicon-containing release layer; however, the leveling properties are poor when used alone. The siloxane antistatic agent contains Si-O bonds, further improving the toughness of the antistatic smoothing layer. Adding too much of the first solvent will result in poor leveling of the smoothing coating liquid, causing pinholes in the resulting antistatic smooth layer; adding too little will result in excessive viscosity of the smoothing coating liquid, producing coating lines. The first catalyst is a benzenesulfonic acid catalyst. Adding too much will shorten the life of the smoothing coating liquid, while adding too little will result in poor curing reaction of the smoothing coating liquid, with insufficient and uneven reaction.

[0041] First solvent

[0042] The first solvent includes toluene, methyl ethyl ketone (MEK), and cyclohexanone. Cyclohexanone, a high-boiling-point solvent, combined with toluene and MEK, not only promotes the miscibility of epoxy resin and siloxane antistatic agents during the formulation process, improving their solubility and thus the leveling properties of the smoothing coating solution; it also improves the compatibility between epoxy resin and siloxane antistatic agents during rapid reaction in the curing and drying process, thereby enhancing the smoothness of the PET substrate. Excessive addition of toluene to the first solvent results in rainbow-like patterns on the surface of the antistatic smoothing layer, affecting the appearance of the release film; insufficient addition of toluene leads to poor dissolution of the raw materials in the smoothing coating solution. Similarly, excessive addition of MEK results in rainbow-like patterns on the surface of the antistatic smoothing layer, affecting the appearance of the release film; insufficient addition of MEK leads to poor dissolution of the raw materials in the smoothing coating solution. Excessive addition of cyclohexanone will result in coating streaks; insufficient addition of cyclohexanone will not only produce rainbow patterns on the surface of the antistatic smoothing layer, but also result in poor compatibility between the uncured epoxy resin and the siloxane antistatic agent during the curing process, which will negatively affect the smoothness of the film surface.

[0043] Release coating liquid

[0044] The formulation includes main silicone oil, crosslinking agent, anchoring agent, secondary catalyst, hydroxyl-modified silicone oil, and secondary solvent. Main silicone oil is the most important raw material in the formulation, affecting the release force performance, stability, and smoothness of the release layer. Good adhesion between main silicone oil and the antistatic smoothing layer not only allows for low-temperature curing, effectively avoiding defects such as release film shrinkage after heat curing, but also facilitates the coating of ceramic slurry to produce high-smoothness laminated ceramic capacitors. Furthermore, it allows for rapid reaction and curing, meeting the requirements of ultra-high-speed production, thus improving production efficiency and profits. Excessive crosslinking agent leads to a large increase in release force during release film aging; insufficient crosslinking agent results in incomplete curing of the release film, rendering it unusable. Excessive anchoring agent reduces the reaction rate, or even prevents normal curing; insufficient anchoring agent reduces the adhesion between the release layer and the antistatic layer, and also lowers the residual adhesion rate. The second catalyst is a platinum catalyst. Excessive platinum catalyst increases the cost of the release film, causes the release coating solution to react too quickly, shortens its lifespan, easily produces a gel-like consistency that makes processing impossible, and accelerates the aging of the resulting release film. Insufficient platinum catalyst leads to inadequate curing. Excessive hydroxyl-modified silicone oil reduces the residual adhesion rate of the release film; insufficient hydroxyl-modified silicone oil results in poor peel smoothness, with peaks and troughs, indicating poor peeling smoothness and hindering the adhesion of subsequent ceramic slurry to the release film. Excessive second solvent easily leads to pinholes on the release layer surface; insufficient solvent results in poor leveling properties of the release coating solution and coating streaks.

[0045] Second solvent

[0046] The release liner includes toluene, methyl ethyl ketone (MEK), and n-heptane. Insufficient toluene addition hinders the dissolution of the silicone oil, while excessive toluene can cause pinholes in the release liner before curing, resulting in pinholes when applied to the antistatic smoothing layer. Excessive MEK addition can also lead to pinholes on the release film surface; insufficient MEK addition slows evaporation and hinders low-temperature curing of the release layer. Excessive n-heptane addition can cause rainbow-like patterns on the release film surface; insufficient n-heptane addition results in poor leveling properties of the release liner, making it prone to pinholes when applied to the antistatic layer.

[0047] The method for preparing MLCC release film includes the following steps:

[0048] S1: Prepare a smoothing coating solution and a release coating solution;

[0049] S2: Apply a smoothing coating liquid to at least one surface of the substrate layer using an M400 micro-grooved roller at a coating speed of 55–65 m / min; cure in an oven with 6 sections, each 4 meters long, and perform a first curing and drying process. The continuous drying temperatures are set sequentially as follows: 90±5℃, 110±5℃, 110±5℃, 110±5℃, 110±5℃, 95±5℃, to obtain a preform with an antistatic smoothing layer; the thickness of the antistatic smoothing layer is 0.4–0.8 μm.

[0050] S3: Apply the release coating liquid to the surface of the antistatic smooth layer using an M200 or M250 closed gravure roller at a coating speed of 95–105 m / min; cure in an oven with 6 sections, each 4 meters long; perform a second curing and drying, with the continuous drying temperatures set sequentially as follows: 90±5℃, 115±5℃, 120±5℃, 120±5℃, 125±5℃, 110±5℃, to obtain a film with a release layer; the thickness of the release layer is 0.1–0.2 μm.

[0051] S4: Curing film to obtain MLCC release film. The curing temperature is 50-60℃ and the curing time is more than 48 hours.

[0052] The curing process in S4 effectively reduces the internal stress of the substrate layer and the main silicone oil, which helps to improve the adhesion between the silicone oil and the antistatic layer, and between the antistatic layer and the substrate layer.

[0053] Example 1

[0054] Based on Yingkou Kanghui's PL030NV00M PET substrate.

[0055] The method for preparing MLCC release film includes the following steps:

[0056] S1: Prepare a smoothing coating solution and a release coating solution;

[0057] The smoothing coating liquid includes 10 parts of Mitsubishi bisphenol F type JER807 epoxy resin, 20 parts of COLCOAT-N-103X siloxane antistatic agent, 0.5 parts of RA2000 first catalyst, and 30 parts of first solvent; in the first solvent, the mass ratio of toluene, butanone and cyclohexanone is 1:1:0.22.

[0058] The release coating solution includes 100 parts of Dow Corning LTC-752 main silicone oil, 0.18 parts of Dow Corning 7672 crosslinking agent, 0.46 parts of Dow Corning 9176 anchoring agent, 1.2 parts of Dow Corning 4000 second catalyst, 0.23 parts of Shin-Etsu X-22-343 hydroxyl-modified silicone oil, and 2500 parts of a second solvent; the second solvent includes toluene, methyl ethyl ketone, and n-heptane in a mass ratio of 1:3:0.5.

[0059] S2: Apply a smoothing coating liquid to one surface of the substrate layer using an M400 micro-grooved roller at a speed of 60 m / min; cure in an oven with 6 sections, each 4 meters long, and perform a first curing and drying process. The continuous drying temperatures are set sequentially as follows: 90℃, 110℃, 110℃, 110℃, 110℃, 95℃, to obtain a preform with an antistatic smoothing layer; the thickness of the antistatic smoothing layer is 0.6 μm.

[0060] S3: Apply the release coating liquid to the surface of the antistatic smooth layer using an M200 or M250 closed gravure roller at a coating speed of 100 m / min; cure in an oven with 6 sections, each 4 meters long; perform a second curing and drying, with the continuous drying temperatures set sequentially as follows: 90℃, 115℃, 120℃, 120℃, 125℃, 110℃, to obtain a film with a release layer; the thickness of the release layer is 0.1 μm.

[0061] S4: Curing film to obtain MLCC release film. The curing temperature is 55℃ and the curing time is 48℃ or more.

[0062] Example 2

[0063] Example 2 is based on Example 1, except that the mass ratio of toluene, butanone and cyclohexanone in the first solvent is 1:1:0.18.

[0064] Example 3

[0065] Example 3 is based on Example 1, except that the first solvent consists only of toluene and methyl ethyl ketone (MEK), with a mass ratio of 1:1.

[0066] Example 4

[0067] Example 4 is based on Example 1, except that the mass ratio of toluene, butanone and cyclohexanone in the first solvent is 1:1:0.5.

[0068] Example 5

[0069] Example 5 is based on Example 1, except that the thickness of the antistatic smoothing layer is 0.1 μm.

[0070] Example 6

[0071] Example 6 is based on Example 1, except that the thickness of the antistatic smoothing layer is 1 μm.

[0072] Example 7

[0073] Example 7 is based on Example 1, except that the release coating liquid includes 100 parts of Dow Corning LTC-752 main silicone oil, 0.18 parts of Dow Corning 7672 crosslinking agent, 0.46 parts of Dow Corning 9176 anchoring agent, 1.2 parts of Dow Corning 4000 second catalyst, 1 part of Shin-Etsu X-22-343 hydroxyl-modified silicone oil, and 2500 parts of a second solvent. The composition of other layers remains unchanged, as does the preparation method.

[0074] Comparative Example 1

[0075] Comparative Example 1 is based on Example 1, except that the antistatic agent is polythiophene, which is used instead of siloxane antistatic agents and mixed with epoxy resin.

[0076] Comparative Example 2

[0077] Comparative Example 2 is based on Example 1, except that the smoothing coating liquid includes 25 parts of Mitsubishi bisphenol F type JER807 epoxy resin, 20 parts of COLCOAT-N-103X siloxane antistatic agent, 0.5 parts of RA2000 first catalyst, and 30 parts of first solvent; in the first solvent, the mass ratio of toluene, butanone, and cyclohexanone is 1:1:0.22. The composition of other layers and the preparation method remain unchanged.

[0078] Comparative Example 3

[0079] Comparative Example 3 is based on Example 1, except that no hydroxyl-modified silicone oil was added to the release coating liquid.

[0080] Testing methods for MLCC release film samples:

[0081] 1. Release force test tool: Nitto 31B tape, bonded for 20 minutes, method: peel at 300mm / min and 180°.

[0082] 2. Residual adhesion rate test tool: Nitto 31B tape;

[0083] 3. Resistance standard: ASTM D257; Instrument: American TREK 152-1 surface resistivity tester;

[0084] 4. Release film surface roughness: The KEYENCE non-contact roughness tester was used.

[0085] The measurement results of the examples and comparative examples are shown in the table below:

[0086]

[0087] In Comparative Example 1, when polythiophene and epoxy resin were mixed, the smoothing coating liquid showed agglomeration, indicating that the two were incompatible.

[0088] In Comparative Example 3, the release coating solution did not contain modified silicone oil, resulting in poor adhesion between the slurry and the release film during subsequent processing, as well as poor coatability of the slurry on the release film.

[0089] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A release film based on a common substrate MLCC, comprising: The substrate layer is a non-corona-treated PET substrate; An antistatic smoothing layer is disposed on at least one surface of the substrate layer; A release layer is disposed on the surface of the antistatic smooth layer away from the substrate layer; The feature is that, by mass parts, the smoothing coating liquid of the antistatic smoothing layer comprises 10 parts epoxy resin, 10-25 parts siloxane antistatic agent, 0.3-1 parts first catalyst, and 20-40 parts first solvent; The first solvent includes toluene, butanone, and cyclohexanone, wherein the mass ratio of toluene, butanone, and cyclohexanone is 1:1:(0.2~0.25). By weight, the release coating liquid of the release layer comprises 100 parts of main agent silicone oil, 0.1-0.5 parts of crosslinking agent, 0.3-0.8 parts of anchoring agent, 1-2 parts of second catalyst, 0.1-0.5 parts of hydroxyl-modified silicone oil, and 2000-3000 parts of second solvent; The second solvent comprises toluene, butanone, and n-heptane, wherein the mass ratio of toluene, butanone, and n-heptane is (3~4):(8~10):(1~2). The hydroxyl-modified silicone oil is Shin-Etsu X-22-343; The thickness of the antistatic smoothing layer is 0.4~0.8μm.

2. The release film based on a common substrate MLCC according to claim 1, characterized in that, The siloxane antistatic agent is COLCOAT-N-103X, and the epoxy resin is Mitsubishi bisphenol F type epoxy resin JER807.

3. The release film based on a common substrate MLCC according to claim 1, characterized in that, The main silicone oil is Dow Corning LTC-752.

4. A method for preparing a release film based on a common substrate MLCC as described in any one of claims 1 to 3, characterized in that, Includes the following steps: S1: Prepare a smoothing coating solution and a release coating solution; S2: The smoothing coating liquid is applied to at least one surface of the substrate layer and cured and dried for the first time. The continuous drying temperature is set to 90±5℃, 110±5℃, 110±5℃, 110±5℃, 110±5℃, 95±5℃ in sequence to obtain a blank film with an antistatic smoothing layer. S3: The release coating liquid is applied to the surface of the antistatic smooth layer, and then cured and dried for the second time. The continuous drying temperature is set to 90±5℃, 115±5℃, 120±5℃, 120±5℃, 125±5℃, and 110±5℃ in sequence to obtain a film with a release layer. S4: Curing the film to obtain an MLCC release film.

5. The method for preparing the MLCC release film according to claim 4, characterized in that, The ripening temperature is 50~60℃.

Images