TWI773887B - Release film for ceramic green sheet manufacturing process - Google Patents

Abstract

The present invention relates to a release film for a ceramic green sheet manufacturing process, comprising a base material and a release agent layer disposed on one side of the base material, wherein the release agent layer is made of melamine resin, polyorganosiloxane, poly It is formed from the release agent composition of alkylene glycol and dispersant. The release film for a ceramic green sheet manufacturing process has excellent slurry coatability and has a release surface that maintains an excellent surface state.

Description

Release film for ceramic green sheet manufacturing process

The present invention relates to release films for use in the manufacture of ceramic green sheets.

Conventionally, in the manufacture of multilayer ceramic products such as multilayer ceramic capacitors and multilayer ceramic substrates, ceramic green sheets are formed, and the obtained ceramic green sheets are laminated and fired.

The ceramic green sheet is formed by applying a ceramic slurry containing a ceramic material such as barium titanate and titanium oxide on a release film. The peeling film is required to have a peelability that can be peeled off with a moderate peeling force from a thin ceramic green sheet formed on the peeling film so that the peeling film does not generate cracks, fractures, or the like.

As an example of the above-mentioned release film, Patent Document 1 discloses a release film comprising a base material and a release agent layer provided on one side of the base material, and the release agent layer is a release agent containing a melamine resin and a polyorganosiloxane The composition is hardened. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2017-105092

(The problem to be solved by the invention)

For the release film used in the production of ceramic green sheets, it is required that when the ceramic slurry is applied to the surface opposite to the release agent layer and the base material (hereinafter sometimes referred to as the "release surface"), no slurry formation occurs. Shrinkage crater and good coating. However, when the release agent layer is formed from a release agent composition containing a polyorganosiloxane, shrinkage cavities of the slurry are likely to occur, and coating may become difficult.

Moreover, the said peeling film requires that the surface state of the peeling surface can be maintained favorably. When the surface condition of the peeled surface is not good, defects such as pinholes and uneven thickness are likely to occur in the shaped ceramic green sheets.

The present invention has been made in view of such a situation, and an object of the present invention is to provide a release film for a ceramic green sheet manufacturing process which is excellent in slurry coatability and has a release surface that maintains an excellent surface state. (the way to solve the problem)

In order to achieve the above object, first, the present invention provides a release film for a ceramic green sheet manufacturing process, which is a release film for a ceramic green sheet manufacturing process comprising a base material and a release agent layer disposed on one side of the base material. , which is characterized in that: the aforementioned release agent layer is formed of a release agent composition containing melamine resin, polyorganosiloxane, polyalkylene glycol, and dispersant (Invention 1).

According to the above invention (Invention 1), the release agent layer is formed of the release agent composition containing the polyalkylene glycol, whereby the generation of shrinkage cavities of the slurry applied to the release surface can be suppressed, and an excellent slurry can be achieved Coatability. In addition, the release agent layer is formed of a release agent composition containing a dispersant, whereby the compatibility between the polyorganosiloxane and the polyalkylene glycol is improved, and the surface of the release surface is maintained in an excellent state.

In the above invention (Invention 1), the aforementioned dispersing agent is preferably a wet dispersing agent (Invention 2).

In the above inventions (Inventions 1 and 2), the content of the dispersant in the release agent composition is 1 mass with respect to 100 parts by mass of the total of the content of the melamine resin and the content of the polyalkylene glycol. Parts or more and 10 parts by mass or less are preferred (Invention 3).

In the above inventions (Inventions 1 to 3), the weight average molecular weight of the polyalkylene glycol is preferably 106 or more and 600 or less (Invention 4).

In the above inventions (Inventions 1 to 4), the content of the polyalkylene glycol in the release agent composition is preferably 10 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the melamine resin (Invention 5).

In the above inventions (Inventions 1 to 5), it is preferable that the polyorganosiloxane has at least one hydroxyl group in one molecule (Invention 6).

In the above inventions (Inventions 1 to 6), the weight average molecular weight of the polyorganosiloxane is preferably 1,000 or more and 10,000 or less (Invention 7).

In the above inventions (Inventions 1 to 7), the content of the aforementioned polyorganosiloxane in the aforementioned release agent composition is 100 parts by mass relative to the total value of the aforementioned content of the melamine resin and the aforementioned content of the polyalkylene glycol, It is preferably 0.5 parts by mass or more and 30 parts by mass or less (Invention 8).

式中，X表示-H、-CH₂ -OH、或-CH₂ -O-R，可各自相同也可不同。R表示碳數1~8個之烷基，可各自相同也可不同。至少1個X為-CH₂ -OH。In the above inventions (Inventions 1 to 8), the melamine resin preferably contains a compound represented by the following general formula (a), or a polynuclear body formed by condensing two or more of the foregoing compounds (Invention 9) [Chemical 1]

In the formula, X represents -H, -CH ₂ -OH, or -CH ₂ -OR, which may be the same or different from each other. R represents an alkyl group having 1 to 8 carbon atoms, and each may be the same or different. At least one X is _-CH2 -OH.

In the above inventions (Inventions 1 to 9), the weight average molecular weight of the melamine resin is preferably 100 or more and 1000 or less (Invention 10).

In the above inventions (Inventions 1 to 10), it is preferable that the release agent composition contains a catalyst (Invention 11). (effect of invention)

The release film for a ceramic green sheet manufacturing process of the present invention is excellent in slurry coatability and has a release surface that maintains an excellent surface state.

Embodiments of the present invention will be described below. The release film for a ceramic green sheet manufacturing process of the present embodiment (hereinafter, abbreviated as "release film" in some cases) includes a base material and a release agent layer provided on one side of the base material. In addition, the release agent layer may be directly laminated on one side of the base material, or may be laminated on one side of the base material via other layers.

1. Components constituting the release film for the manufacturing process of ceramic green sheets (1) Substrate The base material in this embodiment is not particularly limited as long as the release agent layer can be laminated thereon. Examples of the substrate include polyesters such as polyethylene terephthalate and polyethylene naphthalate, polypropylene, polyolefins such as polymethylpentene, polycarbonate, and polyvinyl acetate. The film composed of plastics such as the ethylene oxide can be a single layer or a multi-layer of two or more layers of the same or different types. Among them, polyester films are preferred, polyethylene terephthalate films are particularly preferred, and biaxially stretched polyethylene terephthalate films are more preferred. The polyethylene terephthalate film is less likely to generate dust and the like during processing, use, and the like, and thus can effectively prevent, for example, defects in ceramic slurry coating due to dust and the like. Furthermore, by applying antistatic treatment to the polyethylene terephthalate film, the effect of preventing ignition or poor coating due to static electricity when coating the ceramic slurry using an organic solvent can be enhanced.

In addition, in order to improve the adhesion between the base material and the release agent layer provided on the surface, a surface treatment by an oxidation method, a concavo-convex method, etc., or a primer may be performed on one or both sides of the substrate as necessary. deal with. Examples of the above-mentioned oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet type), flame treatment, hot air treatment, ozone, ultraviolet irradiation treatment, and the like; and as the unevenness method, for example, sandblasting can be used. method, spray treatment method, etc. These surface treatment methods can be appropriately selected according to the type of the base film, and generally, the corona discharge treatment method is preferably used in consideration of effects and workability.

The thickness of the substrate is preferably 10 μm or more, especially 15 μm or more, and even more preferably 20 μm or more. In addition, the thickness of the base material is preferably 300 μm or less, particularly preferably 200 μm or less, and even more preferably 125 μm or less.

(2) Release agent layer The release agent layer in this embodiment is formed of a release agent composition containing melamine resin, polyorganosiloxane, polyalkylene glycol, and dispersant.

In the release film of the present embodiment, since the release agent composition for forming the release agent layer contains polyorganosiloxane, the surface free energy of the release surface of the release agent layer is moderately decreased. Furthermore, since the release agent composition contains a melamine resin, the release agent composition can be sufficiently cured by heating, and the formed release agent layer has sufficient elasticity. Thereby, the peeling force at the time of peeling off the peeling film from the ceramic green sheet formed on the peeling surface of the peeling film is moderately decreased, and favorable peelability can be achieved.

Here, in general, if the surface free energy of the peeling surface is excessively lowered due to the action of polyorganosiloxane, shrinkage cavities are likely to occur when the slurry is applied on the peeling surface. However, the release agent composition in this embodiment contains both polyorganosiloxane and polyalkylene glycol, and the polyalkylene glycol has the effect of increasing the surface free energy of the peeling surface. Therefore, due to the balance between the action of polyorganosiloxane and the action of polyalkylene glycol, the surface free energy of the peeling surface can be suppressed from being excessively lowered. As a result, shrinkage cratering of the slurry applied to the peeling surface can be suppressed, and excellent slurry coatability can be achieved. That is, the release film in this embodiment can achieve both excellent releasability and excellent slurry coatability.

On the other hand, the present inventors have confirmed that the compatibility between polyorganosiloxane and polyalkylene glycol is poor. For example, it was confirmed that even if melamine resin, polyorganosiloxane, and polyalkylene glycol were mixed in a solvent to prepare a coating liquid of the release agent composition, the mixture could not be sufficiently uniformly mixed. Furthermore, when the release agent layer is formed using the coating liquid that is not uniformly mixed as described above, large protrusions frequently appear on the release surface of the formed release agent layer, and a release film having high smoothness cannot be produced.

Compared with this, in the release film of this embodiment, the release agent composition further contains a dispersant, and the compatibility between the polyorganosiloxane and the polyalkylene glycol is improved by the action of the dispersant, and there is no As described above, there is a problem that the surface roughness of the release surface of the release agent layer increases. Therefore, in the release film of the present embodiment, the surface state of the release surface of the release agent layer can be maintained favorably, thereby enabling the formation of ceramic green sheets in which the occurrence of defects such as pinholes and thickness unevenness is suppressed.

In addition, in general, "melamine resin" refers to a mixture containing a plurality of melamine compounds and/or polynuclear bodies obtained by condensing the melamine compounds. In this specification, the term "melamine resin" refers to the above-mentioned mixture or an aggregate of one melamine compound. In addition, in this specification, what hardened this melamine resin is called "melamine hardened|cured material".

(2-1) Melamine resin The melamine resin is not particularly limited as long as it can form a hardened melamine product. In particular, the melamine resin preferably contains a compound represented by the following general formula (a). [hua 2]

In formula (a), X represents -H, -CH ₂ -OH, or -CH ₂ -OR. These groups constitute reactive groups in the condensation reaction of the melamine compounds and the condensation reaction of the hydroxyl groups of polyorganosiloxane and polyalkylene glycol. Specifically, the -NH group formed by X becoming H can undergo a condensation reaction between the -N-CH ₂ -OH group and the -N-CH ₂ -R group. In addition, the -N-CH ₂ -OH group formed by X becoming -CH ₂ -OH and the -N-CH ₂ -R group formed by X becoming -CH ₂ -R may be in the -NH group, -N- A condensation reaction proceeds between the CH ₂ -OH group and the -N-CH ₂ -R group. In addition, the groups represented by -CH ₂ -OH and -CH ₂ -OR constitute a reactive group contributing to the condensation reaction between the hydroxyl group of polyorganosiloxane and polyalkylene glycol and the melamine compound. In formula (a), it is preferable that all X are not all -H, and specifically, at least one X is preferably -CH ₂ -OH or -CH ₂ -OR.

In the group represented by the above -CH ₂ -OR, R represents an alkyl group having 1 to 8 carbon atoms. The number of carbon atoms is preferably 1 to 4, particularly preferably 1 to 2. Alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, etc., especially methyl is preferred.

The above X may be the same or different. In addition, the above R may be the same or different.

From the viewpoint of excellent efficiency of the above condensation reaction, in the formula (a), the number of X that becomes -H is preferably 2 or less, particularly preferably 1 or less, and even more preferably 0. As an example of the melamine compound in which the number of X in -H is 0, a preferable example is hexamethoxymethyl melamine in which X is all -CH ₂ -O-CH ₃ .

The above-mentioned melamine resin may contain 2 to 50 polynuclear bodies formed by condensation of the compound represented by the above formula (a), or may contain polynuclear bodies formed by condensation of 2 to 30 polynuclear bodies, especially 2 to 10 polynuclear bodies. The resulting polynuclear body may further contain 2 to 5 condensed polynuclear bodies.

The weight average molecular weight of the melamine resin is preferably below 1000, especially preferably below 900, and even more preferably below 800. When the weight average molecular weight of the melamine resin is 1000 or less, the sclerosing property of the release agent composition is more excellent, and it becomes easy to form a release agent layer having sufficient coating film strength. As a result, more excellent peelability can be achieved. On the other hand, the weight average molecular weight of the melamine resin is preferably 100 or more, especially 200 or more, and more preferably 300 or more. When the weight-average molecular weight of the melamine resin is 100 or more, the reaction rate of the condensation reaction is stable, and it is easy to form a peeling surface with an excellent surface state. In addition, the weight average molecular weight in this specification is the standard polystyrene conversion value measured by gel permeation chromatography (GPC).

(2-2) Polyorganosiloxane The polyorganosiloxane is not particularly limited as long as it can impart desired releasability to the release agent layer. In the release film of the present embodiment, it is preferable that the polyorganosiloxane has at least one hydroxyl group in one molecule. Since the polyorganosiloxane has a hydroxyl group, the polyorganosiloxane can be fixed to the melamine cured product by the condensation reaction with the melamine resin. As a result, it is easy to inhibit the polyorganosiloxane from the release agent layer to the ceramic green body. slice moves.

The structures other than the above-mentioned hydroxyl groups in the polyorganosiloxane are not particularly limited as long as they do not hinder the above-mentioned peelability and the condensation reaction between the melamine compounds contained in the melamine resin. As the polyorganosiloxane, a polymer of a silicon-containing compound represented by the following general formula (b) can be used. [hua 3]

In formula (b), m is an integer of 1 or more. Moreover, R ¹ to R ⁸ are each independently a hydroxyl group, an organic group (including an organic group having a hydroxyl group), or a group other than these groups. Here, when at least one of R ¹ to R ⁸ is a hydroxyl group or an organic group having a hydroxyl group, at least one of R ³ to R ⁸ is preferably such a group. That is, when the polyorganosiloxane is an organic group having a hydroxyl group or a hydroxyl group, the group preferably exists at the end of the polyorganosiloxane. Due to the presence of hydroxyl groups at the terminal, the condensation reaction between the polyorganosiloxane and the melamine resin is easily carried out, which can effectively inhibit the movement of the polyorganosiloxane.

The above-mentioned organic groups include, for example, polyester groups and polyether groups, and it is particularly preferable that the polyorganosiloxane in this embodiment has at least one of polyester groups and polyether groups. Since the polyorganosiloxane has at least one of a polyester group and a polyether group, the polyorganosiloxane and the melamine resin in the release agent composition are easily and well mixed, and extreme phase separation can be suppressed during curing. Thereby, the condensation reaction of the aforementioned polyorganosiloxane and the melamine resin can proceed well, and the migration of the polyorganosiloxane can also be effectively suppressed. In addition, in this specification, "organic group" does not include the alkyl group mentioned later.

As a group other than a hydroxyl group and an organic group (including an organic group having a hydroxyl group), for example, an alkyl group having 1 to 12 carbon atoms is used. The alkyl group having 1 to 12 carbon atoms such as methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, etc., especially methyl is preferred.

R ¹ to R ⁸ may be the same or different. In addition, when a plurality of R ¹ and R ² are present, R ¹ and R ² may be the same or different from each other.

The weight-average molecular weight of the polyorganosiloxane is preferably below 10,000, particularly preferably below 9,000, and even more preferably below 8,000. When the weight average molecular weight of the polyorganosiloxane is 10,000 or less, the compatibility between the polyorganosiloxane, the melamine resin and the polyalkylene glycol is better, and it is easy to form a release agent layer with an excellent surface state. On the other hand, the weight-average molecular weight of the polyorganosiloxane is preferably 1,000 or more, especially 2,000 or more, and even more preferably 3,000 or more. When the weight average molecular weight of the polyorganosiloxane is 1000 or more, the surface free energy of the polyorganosiloxane on the peeling surface of the release agent layer is easily reduced, and the surface free energy of the polyalkylene glycol is increased. Complementary to each other, it is easy to adjust the surface free energy of the peeling surface to an appropriate range. As a result, it is easy to achieve both the excellent releasability and the excellent slurry coatability of the release film of the present embodiment.

The content of polyorganosiloxane in the release agent composition is preferably 0.5 parts by mass or more, especially 1.0 parts by mass or more, relative to the total value of 100 parts by mass of the content of melamine resin and the content of polyalkylene glycol. good, more preferably 2.0 parts by mass or more. In addition, the content of polyorganosiloxane is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and 10 parts by mass or less with respect to 100 parts by mass of the total of the content of melamine resin and the content of polyalkylene glycol. Better yet. When the content of the polyorganosiloxane is 0.5 parts by mass or more, the peeling film of the present embodiment can easily achieve the desired peelability with respect to the ceramic green sheet. On the other hand, when the content of the polyorganosiloxane is 30 parts by mass or less, the movement of the polyorganosiloxane from the release agent layer to the ceramic green sheet can be effectively suppressed, and the surface free energy of the release surface can be easily adjusted to an appropriate level value, it is easy to achieve excellent slurry coatability.

(2-3) Polyalkylene glycol

The polyalkylene glycol is not particularly limited as long as the surface free energy of the release agent layer on the release surface can be adjusted to an appropriate value by combining the action with polyorganosiloxane. In addition, the polyalkylene glycol can undergo a condensation reaction with the aforementioned reactive group possessed by the melamine resin through the hydroxyl group present at the terminal. Therefore, in the release film of the present embodiment, the release agent layer is hardened by the melamine resin interposed by the polyalkylene glycol. Therefore, compared with the case where the melamine resins are directly bonded to each other, the surface hardness of the release agent layer can be appropriately Under pressure, it is easy to adjust the peeling force of the ceramic green sheet. Moreover, when ethylene glycol is used instead of polyalkylene glycol, when the release agent composition is hardened to form a release agent layer, ethylene glycol volatilizes and it is difficult to form a hardened release agent layer stably. In contrast, the release sheet of the present embodiment can form a well-hardened release agent layer by using polyalkylene glycol to suppress volatilization, and can achieve stable slurry coatability and stable ceramic green embryos peelability of the sheet.

The polyalkylene glycol is preferably 2 to 4 in terms of carbon number of the alkylene group in the alkylene glycol as its constituent unit. Specific examples of the polyalkylene glycol include polyethylene glycol, polypropylene glycol, polybutylene glycol, and polyglycerol. Among these, the surface free energy of the release surface in the release agent layer can be easily adjusted to an appropriate level. From the viewpoint of scope, polyethylene glycol is preferred.

The weight average molecular weight of the polyalkylene glycol is preferably below 600, especially preferably below 500, and even more preferably below 400. When the weight average molecular weight of the polyalkylene glycol is 600 or less, the sclerosing property of the release agent composition is more excellent, and it becomes easy to form a release agent layer having sufficient coating film strength. On the other hand, the weight average molecular weight of the polyalkylene glycol is preferably 106 or more, especially 150 or more, and even more preferably 200 or more. Since the weight average molecular weight of the polyalkylene glycol is 106 or more, the polyalkylene glycol can easily increase the surface free energy of the peeling surface of the release agent layer, and reduce the surface free energy caused by the polyorganosiloxane. The functions complement each other, and the surface free energy of the peeling surface can be easily adjusted to an appropriate range. As a result, the release film of the present embodiment is more excellent in releasability with respect to ceramic green sheets, and at the same time, it is more excellent in slurry coatability.

The content of the polyalkylene glycol in the release agent composition is preferably 10 parts by mass or more relative to 100 parts by mass of the melamine resin, particularly preferably 50 parts by mass or more, and even more preferably 75 parts by mass or more. In addition, the content of the polyalkylene glycol is preferably 150 parts by mass or less, particularly preferably 125 parts by mass or less, and even more preferably 100 parts by mass or less, relative to 100 parts by mass of the melamine resin. When the content of the polyalkylene glycol is 10 parts by mass or more, it is easy to adjust the surface free energy of the peeling surface to an appropriate range. As a result, the peeling film of this embodiment is more excellent in peelability to the ceramic green sheet, and at the same time. Slurry coatability is more excellent. On the other hand, when the content of polyalkylene glycol is 150 parts by mass or less, the compatibility with polyorganosiloxane is more excellent, and it is easy to form a release agent layer with an excellent surface state. Furthermore, the release agent composition is more excellent in curability, and it is easy to form a release agent layer having sufficient coating film strength.

(2-4) Dispersant The dispersant is not particularly limited as long as the compatibility between the polyorganosiloxane and the polyalkylene glycol can be sufficiently improved. The dispersing agent in this embodiment is preferably a wetting dispersing agent that also has a wetting effect on the object to be dispersed, especially a dispersing agent containing a base having an affinity for pigments, considering the viewpoint of effectively improving such compatibility. agent is better.

The dispersing agent in this embodiment, such as fatty acid salt (soap), α-sulfonic acid fatty acid ester salt (MES), alkyl benzene sulfonate (ABS), linear alkyl benzene sulfonate (LAS), Alkyl sulfate (AS), alkyl ether sulfate (AES), low molecular weight anionic (anionic) compounds such as alkyl sulfate triethanol, fatty acid glycolamide, polyoxyethylene alkyl ether (AE), polyoxyethylene Low molecular weight nonionic compounds such as alkyl phenyl ether (APE), sorbitol and sorbitan anhydride, low molecular weight such as alkyl trimethyl ammonium salt, dialkyl dimethyl ammonium chloride, and alkyl pyridine chloride Cationic compounds, alkyl carboxybetaines, sulfobetaines, low molecular amphoteric compounds such as lecithin, formalin condensates of naphthalene sulfonates, polystyrene sulfonates, polyacrylates, Copolymer salts of vinyl compounds and carboxylic acid monomers, polymer water-based dispersants represented by carboxymethyl cellulose, polyvinyl alcohol, etc., modified acrylic block copolymers, block copolymers with affinity for pigments Segmented copolymers, polyacrylic acid partial alkyl esters, polyalkylene polyamines such as polymer non-aqueous dispersants, polyethyleneimine, aminoalkyl methacrylate copolymers such as polymer cationic dispersants, etc. . Among them, as for the dispersing agent in this embodiment, considering the viewpoint of effectively improving the above-mentioned compatibility, the polymer and non-ionic ones are preferred, especially the polymer water-based dispersion in accordance with both of them. At least one of an agent and a polymer non-aqueous dispersant is preferred. Among them, the dispersant in this embodiment is preferably at least one of a modified acrylic block copolymer and a block copolymer having affinity for pigments.

The content of the dispersant in the release agent composition is preferably 1 part by mass or more, especially preferably more than 2 parts by mass, relative to the total value of 100 parts by mass of the content of melamine resin and the content of polyalkylene glycol, and 3 parts by mass or more. Parts by mass or more are also preferred. In addition, the content of the dispersant is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 5 parts by mass or less, relative to 100 parts by mass of the total value of the content of the melamine resin and the content of the polyalkylene glycol. good. When the content of the dispersant is 1 part by mass or more, the compatibility between the polyorganosiloxane and the polyalkylene glycol can be effectively improved, and a release agent layer with an excellent surface state can be easily formed. On the other hand, when the content of the dispersant is 10 parts by mass or less, it is easy to adjust the peelability of the release film of the present embodiment to be within a desired range.

(2-5) Catalyst The release agent composition in the present embodiment preferably contains a catalyst from the viewpoint of enabling the aforementioned condensation reaction performed by the melamine resin to proceed efficiently. Such catalysts, such as acid catalysts, are preferred, specifically, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, phosphorous acid, p-toluenesulfonic acid, etc. are preferred, and p-toluenesulfonic acid is particularly preferred.

The content of the catalyst in the release agent composition is preferably 0.1 part by mass or more, particularly preferably 0.5 part by mass or more, more preferably 1 part by mass or more, relative to 100 parts by mass of the melamine resin. Moreover, the content is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less.

(2-6) Other ingredients In addition to the above-mentioned components, the release agent composition may contain a crosslinking agent, a reaction inhibitor, an adhesion promoter, a lubricant, and the like.

(2-7) Physical properties of the release agent layer In the release film of this embodiment, the surface free energy of the release surface of the release agent layer is preferably 25.0mJ/ ^m2 or more, especially 25.5mJ/ ^m2 or more, 26.0mJ /m ² or more is more preferable. In addition, the surface free energy is preferably 30.0 mJ/m ² or less, particularly preferably 28.0 mJ/m ² or less, and more preferably 27.0 mJ/m ² or less. In the release film of the present embodiment, the release agent layer is formed by using a release agent composition containing polyorganosiloxane and polyalkylene glycol, so that the surface free energy of the release surface can be easily adjusted to be within the above-mentioned range. In addition, when the surface free energy is within the above-mentioned range, the release film of the present embodiment can exhibit good releasability with respect to the molded ceramic green sheet, and is excellent in coatability when the slurry is applied on the release surface. In addition, the measurement method of surface free energy is shown in the test example mentioned later.

The thickness of the release agent layer is preferably 0.01 μm or more, more preferably 0.03 μm or more, particularly preferably 0.05 μm or more, and more preferably 0.1 μm or more. In addition, the thickness is preferably 2.0 μm or less, particularly preferably 1.0 μm or less, and more preferably 0.5 μm or less. When the thickness of the release agent layer is 0.01 μm or more, the release film exhibits sufficient releasability. Moreover, when the thickness of a release agent layer is 2.0 micrometers or less, when a release film is wound in a roll shape, it can suppress that blocking occurs.

2. The physical properties of the peeling film used in the manufacturing process of ceramic green sheets In the peeling film of the present embodiment, the proportion of the area occupied by protrusions having a height of 50 nm or more in the peeling surface is preferably less than 10%, more preferably less than 5%, more preferably less than 2%. In the release film of the present embodiment, by forming the release agent layer with the release agent composition containing the dispersant, the compatibility between the polyorganosiloxane and the polyalkylene glycol contained in the release agent composition is improved , the results are easily in line with the above ratios. In addition, when the above ratio is less than 10%, the surface of the peeling surface is easily maintained in an excellent state without large-scale protrusions, and the peeling film of the present embodiment can be easily used to form a ceramic in which the occurrence of defects such as pinholes and thickness unevenness is suppressed. Embryos. In addition, the details of the measuring method of the said ratio are described in the test example mentioned later.

In the peeling film of the present embodiment, the peeling force required for peeling the peeling film from the ceramic green sheet formed on the peeling surface can be appropriately set, but for example, it is preferably 10 mN/40 mm or more, especially 15 mN/ 40mm or more is preferred, and 20mN/40mm or more is even more preferred. In addition, the peeling force is preferably, for example, 50 mN/40 mm or less, particularly 40 mN/40 mm or less, and still more preferably 30 mN/40 mm or less. In the release film of the present embodiment, since the release agent layer is formed of a release agent composition containing a melamine resin and a polyorganosiloxane, the above-mentioned release force can be easily set. In addition, the details of the measurement method of the said peeling force are described in the test example mentioned later.

3. Manufacturing method of peeling film for ceramic green sheet manufacturing process The method for producing the release film of the present embodiment is not particularly limited as long as it includes forming a release agent layer from the release agent composition. For example, after applying a coating liquid containing the aforementioned release agent composition and an optional organic solvent to one side of the substrate, the obtained coating film is dried and heated to harden the release agent composition to form a release agent layer , it is better to obtain a release film.

Specific methods of the above-mentioned coating include, for example, gravure coating, rod coating, spray coating, spin coating, knife coating, roll coating, die coating, and the like.

The above-mentioned organic solvents are not particularly limited, and various ones can be used. For example, hydrocarbon compounds such as toluene, hexane, heptane, isopropanol, isobutanol, acetone, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and mixtures thereof, etc. In particular, a mixture of methyl ethyl ketone and isopropanol is preferred.

The above-mentioned coated release agent composition is preferably thermally hardened. In this case, the heating temperature is preferably 120°C or higher, especially 125°C or higher. In addition, the heating temperature is preferably 140°C or lower, particularly preferably 135°C or lower. The heating time for thermal hardening is preferably 30 seconds or more, especially 50 seconds or more. In addition, the heating time is preferably 120 seconds or less, particularly preferably 90 seconds or less.

4. How to use the peeling film for the manufacturing process of ceramic green sheets The peeling film in this embodiment is preferably used in the production of ceramic green sheets. In this case, first, a ceramic slurry containing ceramic materials such as barium titanate and titanium oxide is applied to the release surface of the release agent layer. Here, in the release film of the present embodiment, the release agent layer is formed of a release agent composition containing a polyalkylene glycol, whereby an excessive decrease in the surface free energy of the release surface of the release agent layer can be suppressed. As a result, when the slurry is applied to the peeling surface, it is possible to suppress the occurrence of shrinkage holes in the slurry and achieve excellent slurry coatability.

The above-mentioned coating can be performed using, for example, a slot die coating method, a doctor blade method, or the like. Moreover, as a binder component contained in a ceramic slurry, for example, a butyral resin, an acrylic resin, etc. are mentioned. The solvent contained in the ceramic slurry is, for example, an organic solvent, an aqueous solvent, and the like.

After coating the release surface with the slurry, the ceramic green sheet can be shaped by drying the coated ceramic slurry. Here, in the release film of this embodiment, the release agent composition contains a dispersant to improve the compatibility between the polyorganosiloxane and the polyalkylene glycol in the release agent composition, and the release agent is formed. The smoothness of the peeling surface of the layer is high. Thereby, a ceramic green sheet in which the occurrence of defects such as pinholes and uneven thicknesses can be suppressed can be formed.

After the ceramic green sheet is formed, the ceramic green sheet is separated from the release film. At this time, in the release film of the present embodiment, the release agent layer is formed of a release agent composition containing melamine resin and polyorganosiloxane, and the release film has excellent releasability to ceramic green sheets. Therefore, the ceramic green sheet can be peeled off with a moderate peeling force without cracking, breaking, or the like.

The embodiments described above are described in order to facilitate understanding of the present invention, and are not intended to limit the present invention. Therefore, each element disclosed in the above-described embodiment also includes all design changes and equivalents that belong to the technical scope of the present invention.

For example, other layers such as an antistatic layer may be provided on the surface on the opposite side of the base material and the release agent layer, or between the base material and the release agent layer. [Example]

Hereinafter, the present invention will be specifically described with reference to Examples and the like, but the scope of the present invention is not limited to these Examples and the like.

[Example 1] As a melamine resin, methylated melamine resin (manufactured by Sanwa Chemical Co., Ltd., product name "MW-30MLF", weight average molecular weight: 714) 90 mass parts (solid content conversion value, the same below), as polyalkylene dialkylene Alcohol polyethylene glycol (manufactured by Sanyo Chemical Industry Co., Ltd., product name "PEG-400", weight average molecular weight: 401) 10 parts by mass, as polyether modified polydimethylsiloxane containing hydroxyl group Methylsiloxane (manufactured by BYK Chemie Japan, product name "BYK-377", number average molecular weight (Mn) 5078, weight average molecular weight (Mw) 5993, molecular weight distribution (Mw/Mn) 1.18) 5 parts by mass, as Dispersant modified acrylic block copolymer (manufactured by BYK Corporation, product name "DISPERBYK-2025", wetting dispersant) 5.0 parts by mass, and 5 parts by mass of p-toluenesulfonic acid as a catalyst in isopropanol It mixed with the mixed solvent (mass ratio 5:5) of methyl ethyl ketone, and obtained the coating liquid of the release agent composition with a solid content of 3 mass %.

The obtained coating liquid was uniformly coated on one side of a biaxially stretched polyethylene terephthalate film (thickness: 38 μm) as a base material using a coating bar. Then, the obtained coating film was heat-dried at 135 degreeC for 1 minute, it was hardened, and the release film which laminated|stacked the release agent layer of thickness 1.0 micrometers on the base material was obtained.

In addition, the thickness of the release agent layer was measured using an ellipsometry (manufactured by JA Woollam Japan, product name "M-2000").

[Example 2] Except having changed the content of melamine resin and polyalkylene glycol as shown in Table 1, it carried out similarly to Example 1, and obtained the peeling film.

[Example 3] The contents of melamine resin and polyalkylene glycol were changed as shown in Table 1, and a block copolymer having affinity for pigments (manufactured by BYK Corporation, product name "DISPERBYK-2155", wetting dispersant) was used as A release film was obtained in the same manner as in Example 1 except that the dispersant was used.

[Example 4] Except having changed the content of melamine resin and polyalkylene glycol as shown in Table 1, it carried out similarly to Example 1, and obtained the peeling film.

[Comparative Examples 1 and 2] A release film was obtained in the same manner as in Example 1, except that the contents of the melamine resin, polyalkylene glycol, and dispersant were changed as shown in Table 1.

[Test Example 1] (Evaluation of peelability)

In 100 parts by mass of barium titanate (BaTiO ₃ ; manufactured by Sakai Chemical Co., Ltd., product name "BT-03"), and 10 mass parts of butyral-based binder resin (manufactured by Sekisui Chemical Co., Ltd., product name "BM-2") parts, and 120 parts by mass of a mixed solution of toluene and ethanol (mass ratio 5:5) to 5 parts by mass of dioctyl phthalate (manufactured by Kanto Chemical Co., Ltd., product name "Dioctyl phthalate deer grade 1") to obtain A ball mill is used to mix and disperse it to prepare a ceramic slurry.

The above-mentioned ceramic slurry was uniformly coated on the release surface of the release agent layer in the release film stored at room temperature for 48 hours after the production of Examples and Comparative Examples, and then dried with a dryer. Thereby, a ceramic green sheet having a thickness of 3 μm was formed on the release film. The release film with the ceramic green sheet obtained in this way was cut into a width of 40 mm and used as a measurement sample.

The base material side of the measurement sample was fixed to a rigid plate, and a tensile tester (manufactured by Shimadzu Corporation, product name "AG-IS500N") was used to test the ceramics at a peeling angle of 90° and a peeling speed of 0.3 m/min. The green sheet was peeled off from the peeling film, and the force required for peeling (peeling force; mN/40 mm) was measured. The results are shown in Table 1.

Furthermore, based on the peeling force measured as described above, the peelability of the peeling film was evaluated according to the following criteria. The results are shown in Table 1.

○: The peeling force is 10 mN/40 mm or more and less than 30 mN/40 mm.

△: The peeling force is 30 mN/40 mm or more and less than 40 mN/40 mm.

×: The peeling force was less than 10 mN/40 mm or more than 40 mN/40 mm.

[Test Example 2] (Evaluation of the state of the release surface of the release film)

For the peeling surfaces of the peeling films produced in Examples and Comparative Examples, an optical interferometric surface roughness meter (manufactured by Japan Veeco Co., Ltd., product name "NT1100", magnification: 50 times, PSI mode, measurement area: 91.2 μm×119.8 μm ), and the ratio of the occupied area of the protrusions with a corresponding height of 50 nm or more existing per unit measurement area was calculated. The results are shown in Table 1. In addition, the state of the peeling surface was evaluated according to the following criteria. The results are also shown in Table 1. ○: The above ratio is less than 10%. ╳: The above ratio is more than 10%.

[Test Example 3] (Measurement of the surface free energy of the peeling surface of the peeling film) For the peeling films produced in Examples and Comparative Examples, the contact angles of various droplets to the peeling surface of the peeling agent layer were measured, and according to this value, the ‧Bata theory to calculate surface free energy (mJ/m ² ). The contact angle was measured by a static drop method according to JIS R3257:1999 using a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., product name "DM-701"). For the droplets, diiodomethane was used as a "dispersion component", 1-bromonaphthalene was used as a "bipolar component", and distilled water was used as a "hydrogen bond component". The results are shown in Table 1.

[Test Example 4] (Evaluation of coating properties of ceramic slurry) In 100 parts by mass of barium titanate (BaTiO ₃ ; manufactured by Sakai Chemical Industry Co., Ltd., product name "BT-03"), polyvinyl butyral (Sekisui Chemical Industry Co., Ltd.) manufactured, product name "ESLEC B·KBM-2") 10 mass parts, and dioctyl phthalate (manufactured by Kanto Chemical Co., Ltd., product name "dioctyl phthalate deer grade 1") 69 mass parts of toluene was added parts and 46 parts by mass of ethanol, mixed and dispersed with a ball mill to prepare a ceramic slurry.

After the production of Examples and Comparative Examples, the release surface of the release agent layer in the release film stored at room temperature for 48 hours was uniformly coated with the ceramic slurry using a spreader, and then dried at 80° C. for 1 minute with a dryer. Thereby, a ceramic green sheet having a thickness of 3 μm was obtained on the release film.

The state of the ceramic green sheet in the release film with the ceramic green sheet obtained in this way was confirmed, and the applicability of the ceramic slurry was evaluated according to the following criteria. The results are shown in Table 1. ○: Flange did not occur at the coating end of the slurry. ╳: Fringe occurs at the coated end of the slurry.

In addition, the details of the abbreviations etc. described in Table 1 are as follows.

[Dispersant]

D1: Modified acrylic block copolymer (manufactured by BYK Corporation, product name "DISPERBYK-2025", wetting dispersant)

D2: Block copolymer with affinity for pigments (manufactured by BYK Corporation, product name "DISPERBYK-2155", wetting dispersant)

As can be seen from Table 1, in the release films obtained in Examples, it was found that a release surface with an excellent surface state was formed. Moreover, it turned out that the surface free energy was moderately high in the peeling film obtained in the Example, and it was excellent in the slurry coatability. In addition, it was found that the peeling films obtained in Examples could be peeled off with a moderate peeling force when peeled from the ceramic green sheet.

[industrial availability]

The peeling film for the manufacturing process of the ceramic green sheet of the present invention is suitable for forming the ceramic green sheet.

none.

Claims (11)

A release film for a ceramic green sheet manufacturing process, which is a release film for a ceramic green sheet manufacturing process comprising a base material and a release agent layer disposed on one side of the base material, The release agent layer is formed of a release agent composition containing melamine resin, polyorganosiloxane, polyalkylene glycol, and dispersant. The release film for a ceramic green sheet manufacturing process according to claim 1, wherein the dispersant is a wetting dispersant. For the release film used in the manufacturing process of ceramic green sheets as described in item 1 of the claimed scope, the content of the dispersant in the release agent composition is relative to the content of the melamine resin and the content of the polyalkylene glycol The total value of 100 parts by mass is 1 part by mass or more and 10 parts by mass or less. The release film for a ceramic green sheet manufacturing process according to claim 1, wherein the polyalkylene glycol has a weight-average molecular weight of 106 or more and 600 or less. The release film for a ceramic green sheet manufacturing process as described in claim 1, wherein the content of the polyalkylene glycol in the release agent composition is 10 parts by mass relative to 100 parts by mass of the melamine resin part by mass or more and less than or equal to 150 parts by mass. The peeling film for a ceramic green sheet manufacturing process according to claim 1, wherein the polyorganosiloxane has at least one hydroxyl group in one molecule. The release film for a ceramic green sheet manufacturing process as described in claim 1, wherein the polyorganosiloxane has a weight-average molecular weight of 1,000 or more and 10,000 or less. The release film for a ceramic green sheet manufacturing process as described in claim 1, wherein the content of the polyorganosiloxane in the release agent composition is relative to the content of the melamine resin and the polyalkylene The total value of the content of the base diol is 0.5 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass. The release film for a ceramic green sheet manufacturing process as described in claim 1, wherein the melamine resin contains a compound represented by the following general formula (a), or a polynuclear body formed by condensation of two or more of the compounds;

In the formula, X represents -H, -CH ₂ -OH, or -CH ₂ -OR, which can be the same or different from each other; R represents an alkyl group with 1 to 8 carbon atoms, which can be the same or different from each other; at least one X is -CH ₂ -OH. The release film for a ceramic green sheet manufacturing process described in claim 1, wherein the weight average molecular weight of the melamine resin is 100 or more and 1000 or less. The release film for a ceramic green sheet manufacturing process according to claim 1, wherein the release agent composition contains a catalyst.