KR102093769B1 - Release film for green sheet production - Google Patents

Abstract

The release film for producing a green sheet of the present invention includes a base material and a release agent layer, and the release agent layer has at least one reactive functional group selected from the group consisting of (meth) acryloyl group, alkenyl group, and maleimide group, and is active energy ray-curable. It is formed by irradiating an active energy ray to a coating layer formed by applying a material for forming a release agent layer containing the compound (A), polyorganosiloxane (B), and carbon nanomaterial (C) on the first surface. It is characterized in that the arithmetic mean roughness Ra ₁ of the outer surface of the release agent layer is 8 nm or less, and the maximum protrusion height Rp ₁ of the outer surface of the release agent layer is 50 nm or less. ADVANTAGE OF THE INVENTION According to this invention, the peeling film for green sheet manufacture which can prevent the occurrence of pinholes or partial thickness variation on the surface of a green sheet, and can manufacture a highly reliable green sheet can be provided.

Description

Release film for green sheet production {RELEASE FILM FOR GREEN SHEET PRODUCTION}

The present invention relates to a release film for producing a green sheet.

In the manufacture of a ceramic capacitor, a release film for producing a green sheet is used to form a green sheet.

The release film is generally composed of a base material and a release agent layer. The green sheet is produced by applying a ceramic slurry on which a ceramic particle and a binder resin are dispersed and dissolved in an organic solvent on such a release film, and drying it. In addition, the produced green sheet is peeled from the release film, and is used for the production of ceramic capacitors.

In the production of a green sheet using a conventional release film, there has been a problem such that pinholes are generated on the surface of the green sheet by transferring irregularities on the surface of the release film to the green sheet.

Therefore, attempts have been made to reduce the influence of the unevenness on the green sheet by suppressing the unevenness of the release film surface as much as possible (see, for example, Patent Document 1).

However, with the recent miniaturization and high density of ceramic capacitors, further thinning of the green sheet is required, and the conventional release film cannot cope with the thinning. That is, if a thin green sheet is to be formed, it has been difficult to prevent the occurrence of pinholes or the like caused by unevenness of the surface of the release film transferred to the green sheet in the conventional release film.

In addition, the release film is generally stored and transported in a rolled state, and when a green sheet is formed, it is used after being unwound from the rolled state. Conventionally, when releasing this wound release film, there was a problem that static electricity is generated on the surface of the release film, and foreign matter such as dust adheres to the release film by the generated static electricity. For this reason, if a green sheet is to be produced using a release film, there is a problem that pinholes are generated in the green sheet due to the attached foreign matter or the like. In particular, the smaller the irregularities on the surface of the release film, the more the generation of static electricity as described above was remarkable.

Patent Document 1: Japanese Patent Publication No. 2003-203822

An object of the present invention is to provide a peeling film for producing a green sheet, which can prevent pinholes, partial thickness variations, etc. from occurring on the surface of the green sheet, and can produce a highly reliable green sheet.

This object is achieved by the present invention of the following (1) to (5).

(1) It is a peeling film for green sheet manufacture used for manufacture of a green sheet,

A substrate having a first surface and a second surface; And

And a release agent layer formed on the first surface of the substrate,

The release agent layer is an active energy ray-curable compound (A) having at least one reactive functional group selected from the group consisting of (meth) acryloyl group, alkenyl group, and maleimide group, polyorganosiloxane (B), and carbon It is formed by irradiating active energy rays to the coating layer formed by applying the material for forming the release agent layer containing the nanomaterial (C) to the first surface side,

The release film for green sheet production, characterized in that the arithmetic average roughness Ra ₁ of the outer surface of the release agent layer is 8 nm or less, and the maximum protrusion height Rp ₁ of the outer surface of the release agent layer is 50 nm or less.

(2) The release film for producing a green sheet according to (1), wherein the release agent layer has an average thickness of 0.2 to 2 μm.

(3) The release film for producing the green sheet according to (1) or (2), wherein the content of the polyorganosiloxane (B) in terms of solid content in the material for forming the release agent layer is 0.5 to 5% by mass.

(4) The polyorganosiloxane (B) is a polyorganosiloxane having a linear or branched molecular chain, and at the terminal and / or side chains of the molecular chain, (meth) acryloyl group, alkenyl group and maleimide Peeling for the production of the green sheet according to any one of (1) to (3), wherein the reactive functional group having at least one member selected from the group consisting of groups is bonded to a silicon atom in the molecular chain, either directly or through a divalent linking group. film.

(5) The release film for producing a green sheet according to any one of (1) to (4), wherein the content of the carbon nanomaterial (C) in terms of solid content in the material for forming the release agent layer is 0.05 to 10% by mass.

ADVANTAGE OF THE INVENTION According to this invention, the peeling film for green sheet manufacture which is excellent in the smoothness of the outer surface of a release agent layer, and has excellent antistatic property and peelability can be provided. Thereby, it is possible to prevent the unevenness of the surface of the release film for producing the green sheet from being transferred to the green sheet. As a result, it is possible to prevent the occurrence of pinholes or partial thickness variations on the surface of the green sheet.

Moreover, the release film for green sheet manufacture of this invention has moderate electroconductivity. For this reason, the resistance value of the surface of the release film for green sheet manufacture can be made low. Thereby, when unwinding the peeling film for manufacture of a wound green sheet, generation | occurrence | production of static electricity can be suppressed. As a result, it is possible to prevent foreign matter such as dust from adhering to the surface of the release film for producing a green sheet, so that it is possible to prevent the formation of pinholes on the surface of the manufactured green sheet or the splashing of the slurry when applying the ceramic slurry. have. In addition, when peeling off the green sheet, it is possible to prevent peeling defects due to charging and the like, and to prevent damage or wrinkles from occurring on the green sheet.

1 is a cross-sectional view of a release film for producing a green sheet of the present invention.

Hereinafter, the present invention will be described in detail based on preferred embodiments.

≪ Peeling film for green sheet production ≫

The release film for producing a green sheet of the present invention is used for the production of a green sheet. And the produced green sheet is used for manufacture of, for example, a ceramic capacitor.

1 is a cross-sectional view of a release film for producing a green sheet of the present invention. In addition, in the following description, the upper side in FIG. 1 is called "above", and the lower side is called "below".

As shown in FIG. 1, the release film 1 for producing a green sheet includes a substrate 11 having a first surface 111 and a second surface 112; And a release agent layer 12 formed on the first surface 111 of the substrate 11. That is, as shown in FIG. 1, the release film 1 for producing a green sheet forms a two-layer structure laminated so that the substrate 11 and the release agent layer 12 are bonded to each other in this order.

In addition, in the present specification, when a green sheet is manufactured using the release film 1 for producing a green sheet, the green sheet is, for example, by applying a dissolved ceramic slurry on the outer surface 121 of the release agent layer 12. Is formed.

In the present invention, the release film 1 for producing a green sheet includes a base 11 and a release agent layer 12. In the release film 1 for producing a green sheet, the release agent layer 12 contains an active energy ray-curable compound (A) having a predetermined reactive functional group, polyorganosiloxane (B), and carbon nanomaterial (C). The material for forming the release agent layer to be formed is formed by applying to the first surface 111 side of the substrate 11 and irradiating thereon with an active energy ray, and arithmetic mean of the outer surface 121 of the release agent layer 12 It is characterized in that the roughness Ra ₁ is 8 nm or less, and the maximum protrusion height Rp ₁ of the outer surface 121 is 50 nm or less.

By having such characteristics, it is possible to obtain a release film 1 for producing a green sheet having excellent anti-static properties and peeling properties as well as excellent smoothness of the outer surface 121 of the release agent layer 12. Then, when the green sheet is produced using the release film 1 for producing the green sheet, it is possible to prevent occurrence of pinholes, partial thickness variations, and the like on the surface of the green sheet.

In particular, the release agent layer 12 has suitable conductivity by the action of the carbon nanomaterial (C). For this reason, the resistance value of the surface of the release film 1 for green sheet manufacture can be made low. Thereby, generation | occurrence | production of static electricity can be suppressed when unwinding the peeling film 1 for manufacture of the wound green sheet. As a result, it is possible to prevent foreign matter such as dust from adhering to the surface of the release film 1 for producing a green sheet, and to prevent the occurrence of pinholes due to the foreign matter attached.

Further, the release agent layer 12 exhibits excellent release properties by the action of the polyorganosiloxane (B). For this reason, the release agent layer 12 is a release film for producing a green sheet by using the synergistic effect of anti-static property by the action of the polyorganosiloxane (B) and the anti-static property by the action of the carbon nanomaterial (C) ( When peeling in 1), it is possible to prevent damage or wrinkles from occurring on the green sheet.

Further, the material for forming the release agent layer containing the active energy ray-curable compound (A) having a predetermined reactive functional group has moderate fluidity and shape retention. For this reason, when the release agent layer 12 made of such a release agent layer forming material is used, the unevenness of the surface of the substrate 11 can be easily filled (cancelled). In addition, it is possible to reliably maintain the buried state. As a result, the outer surface 121 of the release agent layer 12 becomes excellent in smoothness. For this reason, it is possible to prevent the occurrence of pinholes or the like caused by the uneven shape of the outer surface 121 of the release agent layer 12 transferred to the formed green sheet.

In addition, since the arithmetic mean roughness Ra ₁ and the maximum protrusion height Rp ₁ of the outer surface 121 of the release agent layer 12 are the above, even if, for example, a green sheet of thin film having a thickness of less than 1 μm is produced, the release agent It is possible to prevent the unevenness of the outer surface 121 of the layer 12 from being transferred to the green sheet. Accordingly, it is possible to obtain a highly reliable green sheet in which occurrence of pinholes or the like is prevented on the surface of the green sheet.

Hereinafter, each layer constituting the release film 1 for producing a green sheet according to the present embodiment will be sequentially described.

<Substrate (11)>

The base material 11 has a function of imparting physical strength such as stiffness and flexibility to the release film 1 for producing a green sheet (hereinafter, simply referred to as “release film 1”).

The substrate 11 includes a first surface 111 and a second surface 112, as shown in FIG. 1.

The material constituting the base 11 is not particularly limited, and for example, polyester resins such as polybutylene terephthalate resin, polyethylene terephthalate resin, and polyethylene naphthalate resin, polypropylene resin and polymethylpentene resin, etc. And films made of plastics such as polyolefin resins and polycarbonates. The base material 11 may be a single-layer film or a multilayer film of two or more layers of the same kind or different kinds. Among these, it is preferable that it is a polyester film especially, and a biaxially stretched polyethylene terephthalate film is more preferable. In particular, the polyester film is difficult to generate dust or the like during processing or use. For this reason, for example, in the case of producing a green sheet using the release film 1 produced using a polyester film, it is possible to effectively prevent a ceramic slurry coating failure due to dust or the like. As a result, a green sheet with fewer pinholes or the like can be produced.

Further, in addition to the above-described materials, the base material 11 may contain a filler or the like. Examples of the filler include silica, titanium oxide, calcium carbonate, kaolin, and aluminum oxide, and one or two or more of them can be used in combination. By including such a filler, while giving mechanical strength to the base material 11, the slipperiness of the front and back surfaces of the base material 11 improves, and blocking can be suppressed.

In addition, the base material 11 is more preferably the first surface 111 is the arithmetic mean roughness Ra ₀ preferably from 2 ~ 80nm, and the arithmetic average roughness Ra ₀ of the first surface 111 of 5 ~ 50nm of. Accordingly, as described later, a smoothing release agent layer 12 is formed on the first surface 111 of the substrate 11 by burying the unevenness of the first surface 111. For this reason, if the arithmetic mean roughness Ra ₀ is within the above range, the smoothing action becomes particularly remarkable.

In addition, when the arithmetic average roughness Ra ₀ of the first surface 111 exceeds the above upper limit, in order to sufficiently fill the unevenness of the first surface 111 depending on the constituent materials of the material for forming the release agent layer, the release agent layer 12 It may be necessary to make the thickness of the film relatively thick.

In addition, the maximum protrusion height Rp ₀ of the first surface 111 is preferably 10 to 700 nm, and the maximum protrusion height Rp ₀ of the first surface 111 is more preferably 20 to 500 nm. Accordingly, as described later, since the unevenness of the first surface 111 is buried on the first surface 111 of the substrate 11 to form a smoothed release agent layer 12, the maximum protrusion height Rp ₀ is the above. When within the range of, the smoothing action becomes particularly remarkable.

In addition, the base 11 is a second arithmetic average roughness Ra ₂ of the surfaces 112 and preferably from 5 ~ 40nm, the second escape is more preferable that the arithmetic average roughness Ra ₂ of 112 of 10 ~ 30nm. In addition, the maximum protrusion height Rp ₂ of the second surface 112 of the substrate 11 is preferably 60 to 500 nm. Accordingly, when the release film 1 having the high smoothness of the outer surface 121 of the release agent layer 12 is wound into a core material such as paper, plastic, or metal, in a roll shape, air discharge is satisfactory. It becomes possible to suppress winding shift effectively. For this reason, it is not necessary to increase the winding tension, and it becomes possible to suppress deformation of the winding core due to the winding tension. In addition, when the roll-shaped release film 1 is released, blocking can be prevented from occurring at the front and rear of the wound release film 1. Furthermore, when the release film 1 on which the green sheet is formed is wound up and stored, the surface shape of the second surface 112 of the substrate 11 in contact with the green sheet can be prevented from being transferred to the green sheet, and Pinholes or partial thickness variations can be prevented. As a result, a highly reliable green sheet can be formed.

On the other hand, if the maximum projection height Rp ₂ is less than the above lower limit, when the release film 1 before the green sheet formation is wound up during storage of the release film 1 before the green sheet (thin film) formation, air is drawn in. It is easy, and winding misalignment is easy to occur. For this reason, handling of the peeling film 1 becomes difficult. Moreover, the base material 11 and the release agent layer 12 come into close contact, and it becomes difficult to sufficiently prevent blocking. On the other hand, when the maximum protrusion height Rp ₂ exceeds the above upper limit, when the release film 1 after forming the green sheet is wound, the protrusion shape of the second surface 112 of the substrate 11 in contact with the green sheet is transferred to the green sheet. Will be. For this reason, there is a possibility that variations in pinholes or partial thickness occur in the green sheet, and it becomes difficult to sufficiently maintain the smoothness of the green sheet.

As described above, the maximum protrusion height Rp ₂ of the second surface 112 of the substrate 11 is preferably 60 to 500 nm, more preferably 80 to 400 nm, and even more preferably 100 to 300 nm. Thereby, the above-mentioned effect becomes more remarkable.

In addition, in this specification, the arithmetic mean roughness Ra ₀ and the maximum protrusion height Rp ₀ of the first surface 111 of the substrate 11, the arithmetic mean roughness Ra ₂ and the maximum protrusion height Rp of the second surface 112 of the substrate 11 ₂ is a value which can be obtained by measuring with the surface roughness measuring instrument SV3000S4 (probe type) manufactured by Mitsutoyo Corporation in accordance with JIS B0601-1994. In addition, unless otherwise specified in this specification, "arithmetic mean roughness and maximum protrusion height" refers to the value obtained by measuring as described above.

In addition, the average thickness of the substrate 11 is not particularly limited, but is preferably 10 to 300 μm, and more preferably 15 to 200 μm. Thereby, while making the flexibility of the release film 1 moderate, it is possible to make the resistance to tearing or breaking particularly excellent.

<Peeling layer (12)>

The release agent layer 12 is formed on the first surface 111 of the substrate 11.

The release agent layer 12 has a function of imparting release property and antistatic property to the release film 1.

The release agent layer 12 is a layer formed by irradiating an active energy ray with a material for forming the release agent layer to cure.

Further, the release agent layer 12 is made of a material for forming the release agent layer. The material for forming the release agent layer is (meth) an active energy ray-curable compound (A) and a polyorganosiloxane (B) having at least one reactive functional group selected from the group consisting of acryloyl groups, alkenyl groups, and maleimide groups, and Carbon nanomaterial (C).

The release agent layer 12 having such a structure has suitable conductivity. For this reason, the resistance value of the outer surface 121 of the release agent layer 12 can be lowered. Thereby, when unwinding the peeling film for manufacture of a wound green sheet, generation | occurrence | production of static electricity can be suppressed. As a result, it is possible to prevent foreign matters from adhering to the outer surface 121 of the release agent layer 12, so that pinholes or the like can be generated in the green sheet. Moreover, since generation | occurrence | production of the wave or frying of a ceramic slurry by charging of the surface of the release agent layer 12 can be prevented, a green sheet of more uniform thickness can be formed. In addition, the release agent layer 12 having such a structure has peelability in addition to appropriate conductivity. For this reason, when peeling a green sheet, generation | occurrence | production of the peeling defect by electrostatic charge can be prevented. As a result, it is possible to prevent damage or wrinkles from occurring on the green sheet.

Hereinafter, each component of the material for forming a release agent layer will be described in detail.

In addition, the material for forming a release agent layer before irradiating active energy rays exists in an uncured state or a semi-cured state at room temperature.

In addition, the material for forming such a release agent layer has adequate fluidity when applied on the first surface 111 of the substrate 11. Therefore, when such a release agent layer forming material is used, the unevenness of the first surface 111 of the base material 11 can be easily embedded and the buried state can be reliably maintained. As a result, it is possible to prevent the unevenness of the substrate 11 from affecting the outer surface 121 side of the release agent layer 12 opposite to the substrate 11, and the outer surface 121 of the release agent layer 12 can be prevented. Can be smoothed.

[Active energy ray-curable compound (A)]

The active energy ray-curable compound (A) is a component that contributes to the formation of the release agent layer 12 by curing. Thereby, the mechanical strength of the release agent layer 12 can be made more suitable.

The active energy ray-curable compound (A) has at least one reactive functional group selected from the group consisting of (meth) acryloyl group, alkenyl group, and maleimide group. Moreover, as said alkenyl group, a C2-C10 alkenyl group, such as a vinyl group, an allyl group, a propenyl group, and a hexenyl group, is illustrated. In particular, it is preferable to have two or more of these reactive functional groups in one molecule, and more preferably to have three or more in one molecule. Accordingly, the release agent layer 12 can obtain excellent curability, solvent resistance, and release properties. Further, the active energy ray-curable compound (A) has moderate fluidity and shape retention. For this reason, when the material for forming a release agent layer containing such an active energy ray-curable compound (A) is applied on the first surface 111 of the substrate 11, the first of the substrate 11 is formed by the release agent layer forming material. The unevenness of the surface 111 can be accurately embedded, and the buried state can be reliably maintained. As a result, the outer surface 121 of the release agent layer 12 can be smoothed.

Moreover, it is preferable that content of the said reactive functional group in active energy ray-curable compound (A) is 10 equivalent or more per kg of active energy ray-curable compound (A). Accordingly, even when applied as a thin film on the first surface 111 of the substrate 11, the curability of the active energy ray-curable compound (A) can be made particularly excellent.

As the active energy ray-curable compound (A), specifically, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylic And polyfunctional (meth) acrylates such as rate, pentaerythritol tri (meth) acrylate, and pentaerythritol tetra (meth) acrylate. Among these, at least 1 selected from the group consisting of dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, pentaerythritol triacrylate, and pentaerythritol tetraacrylate It is preferred to use polyfunctional acrylates of the species. Accordingly, even when applied as a thin film on the first surface 111 of the substrate 11, the curability of the active energy ray-curable compound (A) can be made particularly excellent.

The content of the active energy ray-curable compound (A) in terms of solid content in the release agent layer-forming material (the content ratio in all solid content excluding the solvent) is preferably 65 to 98.5 mass%, and 71 to 94.3 mass% It is more preferable.

[Polyorganosiloxane (B)]

Polyorganosiloxane (B) is a component that exhibits peelability in the release agent layer 12.

As polyorganosiloxane (B), polyorganosiloxane which has a molecular chain of linear or branched is mentioned, for example. In particular, a reactive functional group having at least one member selected from the group consisting of (meth) acryloyl group, vinyl group and maleimide group, wherein a silicon atom is included in the terminal and / or side chain of the molecular chain, is a direct or divalent linking group. Through this, it is preferable that it is bonded to a silicon atom in the molecular chain. The reactive functional group may have at least one in one molecule.

Further, examples of the divalent linking group include an alkylene group, an alkylene oxy group, an oxy group, an imino group, a carbonyl group, and a divalent linking group combining these.

The divalent linking group preferably has 1 to 30 carbon atoms, and more preferably 1 to 10 carbon atoms.

Moreover, polyorganosiloxane (B) can be used in combination of 2 or more type as needed.

The modified polyorganosiloxane substituted with such a reactive functional group is assembled and fixed to the crosslinked structure of the cured product of the active energy ray-curable compound (A) when the active energy ray-curable compound (A) is cured by irradiation with active energy rays. . Thereby, the polyorganosiloxane which is a component of the release agent layer migrates to the green sheet formed on the outer surface 121 side of the release agent layer 12, and it can suppress that electrodeposition.

In addition, examples of the organic group other than the reactive functional group constituting the polyorganosiloxane (B) include a monovalent hydrocarbon group having no aliphatically unsaturated bond. The organic groups may be a plurality of monovalent hydrocarbon groups, or they may be the same or different from each other.

The hydrocarbon group preferably has 1 to 12 carbon atoms, and more preferably 1 to 10 carbon atoms.

Specific examples of the hydrocarbon group include alkyl groups such as methyl group, ethyl group and propyl group, and aryl groups such as phenyl group and tolyl group.

As an organic group other than the reactive functional group having such a structure, it is preferable that 80 mol% or more of the organic group is a methyl group. Thereby, the peelability of the release agent layer 12 can be made especially excellent.

The content of the polyorganosiloxane (B) in terms of solid content in the release agent layer forming material is preferably 0.5 to 5% by mass, more preferably 0.7 to 4% by mass. This makes it possible to apply the ceramic slurry on the substrate 11 without frying, and to make the peeling property of the release film 1 for producing a green sheet particularly excellent.

On the other hand, if the content of the polyorganosiloxane (B) in terms of solid content in the release agent layer forming material is less than the above lower limit, the release agent layer 12 formed depending on the type of the substrate or the like cannot exhibit sufficient peelability. I have a concern. On the other hand, when the content of the polyorganosiloxane in terms of solid content in the release agent layer forming material exceeds the above upper limit, when the ceramic slurry is applied to the surface of the release agent layer 12 to be formed, depending on the constituent materials of the ceramic slurry, etc. There is a possibility that the ceramic slurry is easily fried.

Moreover, when the content of the active energy ray-curable compound (A) is A part by mass and the blending amount of polyorganosiloxane (B) is B part by mass, it is more preferable that the mass ratio B / A is in the range of 0.7 / 99.3 to 5/95. It is preferable, and it is especially preferable that it is 1 / 99-4.5 / 95.5. Thereby, the said effect becomes more remarkable.

[Carbon nanomaterial (C)]

The carbon nanomaterial (C) has a function of imparting antistatic property to the release agent layer 12.

Examples of the carbon nanomaterial (C) include fullerene, carbon nanotubes, carbon nanofibers, and carbon nanohorns, and one or two or more of them can be used in combination. Among these, carbon nanotubes are particularly preferable. Thereby, more suitable conductivity can be provided to the release agent layer 12, and the surface resistance value of the outer surface 121 of the release agent layer 12 can be lowered. For this reason, it is possible to prevent foreign matters from adhering to the outer surface 121 of the release agent layer 12. As a result, it becomes possible to prevent pinholes from being generated in the green sheet formed on the release agent layer 12.

In particular, among the carbon nanomaterials (C) as described above, the carbon nanotubes form a fiber shape having a high aspect ratio (longitudinal degree). For this reason, the carbon nanotube can be easily oriented so that the fiber length thereof follows the plane direction of the release agent layer 12. For this reason, when the carbon nanotube is used, a release agent layer 12 having a moderate conductivity and a smoother outer surface 121 can be obtained.

Moreover, the average diameter (fiber diameter) of the carbon nanomaterial (C) is preferably 1 to 1000 nm, more preferably 3 to 500 nm, and even more preferably 5 to 100 nm.

The average length (fiber diameter) of the carbon nanomaterial (C) is 10 nm to 200 μm, and is not particularly limited, but is preferably 50 nm to 100 μm, and more preferably 100 nm to 50 μm, for example.

In addition, the aspect ratio of the carbon nanomaterial (C) is, for example, preferably 10 to 10000, more preferably 200 to 5000, and even more preferably 400 to 2000. In addition, the aspect ratio of the carbon nanomaterial (C) is a value measured by observing the carbon nanotubes using a scanning electron microscope (manufactured by Hitachi High Technologies, product name “S-4700”).

The content of the carbon nanomaterial (C) in the release agent layer-forming material is, for example, preferably 0.05 to 10% by mass, more preferably 0.1 to 5% by mass, and even more preferably 0.2 to 1% by mass. desirable. When the content of the carbon nanomaterial (C) is less than the above lower limit, the surface resistivity of the release agent layer 12 may not be sufficiently reduced. When the content of the carbon nanomaterial (C) exceeds the above upper limit, the strength of the release agent layer 12 decreases, and there is a concern that solvent resistance may deteriorate.

[Photopolymerization initiator (D)]

In order to cure the material for forming a release agent layer, the material for forming a release agent layer may contain a photopolymerization initiator (D). In particular, in the case of using ultraviolet light as the active energy ray, the material for forming the release agent layer can be more easily and surely cured by using the photopolymerization initiator (D).

Although it does not specifically limit as a photoinitiator (D), For example, it is more preferable to use the alpha-amino alkyl phenone type photoinitiator. Such an α-aminoalkylphenone-based photopolymerization initiator is a compound that is less susceptible to oxygen inhibition when curing the release agent layer-forming material. For this reason, even in the manufacture of the release film 1 under atmospheric atmosphere, particularly excellent curability can be obtained.

Examples of the α-aminoalkylphenone-based photopolymerization initiator include 2-methyl-1 [4- (methyl thio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone 1,2- (dimethylamino)-2-[(4-methylphenyl) methyl]-1- [4- (4-morpholinyl) phenyl]-1-butanone, etc. Can be mentioned. Thereby, especially excellent hardenability, solvent resistance, and peelability can be obtained.

The content of the photopolymerization initiator (D) in terms of solid content in the release agent layer forming material is preferably 1 to 20% by mass, and more preferably 3 to 15% by mass. Thereby, even if the thickness of the release agent layer 12 is a thickness in a range in which it is difficult to obtain curability due to oxygen inhibition, particularly excellent curability, solvent resistance, and peelability can be obtained.

In addition, in such release film 1, the component derived from polyorganosiloxane (B) is segregated in the vicinity of the outer surface 121 of the release agent layer 12. The reasons for such segregation are as follows. By using the polyorganosiloxane (B) having a different molecular structure, polarity, molecular weight, etc. from the active energy ray-curable compound (A), the polyorganosiloxane (B) is applied while the coating layer of the release agent layer-forming material is cured This is because it is pushed up near the surface of the layer.

In addition, the material for forming a release agent layer may contain other components in addition to the components described above. For example, other components such as a sensitizer, an antistatic agent, and a curing agent may be included.

As a sensitizer, 2,4-diethylthioxanthone, isopropylthioxanthone, etc. are mentioned, for example. Thereby, reactivity can be improved more.

In addition, in the material for forming a release agent layer, the content of the other components in terms of solid content is preferably 0 to 10% by mass.

In addition, as described above, the arithmetic mean roughness Ra ₁ of the outer surface 121 of the release agent layer 12 is 8 nm or less, and the maximum protrusion height Rp ₁ is 50 nm or less. Accordingly, when the green sheet is molded on the outer surface 121 side of the release agent layer 12, it is possible to more reliably prevent generation of pinholes or partial thickness variations in the green sheet, and make the surface of the green sheet more visible. You can do it with a smooth object.

The average thickness of the release agent layer 12 is preferably 0.2 to 2 μm, and more preferably 0.3 to 1.5 μm. When the thickness of the release agent layer 12 is less than the above lower limit, the smoothness of the outer surface 121 of the release agent layer 12 becomes insufficient. As a result, when the green sheet is molded on the outer surface 121 side of the release agent layer 12, there is a fear that pinholes, partial thickness variations, and the like occur in the green sheet. On the other hand, when the thickness of the release agent layer 12 exceeds the above upper limit, curling tends to occur in the release film 1 by curing shrinkage of the release agent layer 12. In addition, by winding the release film 1, blocking is liable to occur on the second surface 112 of the substrate 11 and the outer surface 121 of the release agent layer 12. For this reason, there is a possibility that the unwinding of the release film 1 may occur, or the charge amount at the time of unwinding the release film 1 may increase.

In addition, the surface resistivity of the outer surface 121 of the release agent layer 12 is preferably 1.0 × 10 ¹² Pa / □ or less, and more preferably 1.0 × 10 ¹¹ Pa / □ or less. If the surface resistivity is within the above range, it is possible to more reliably reduce the adhesion of the foreign material or the like due to the generation of static electricity to the outer surface 121 of the release agent layer 12.

In addition, surface resistivity means the resistance per unit surface area in this specification. Incidentally, the unit of surface resistivity is Ω / □ in this specification.

Note that the surface resistivity can be measured in accordance with JIS K6911 (1995).

≪ Manufacturing method of release film for green sheet production ≫

Next, a preferred embodiment of the production method of the release film 1 for producing a green sheet as described above will be described.

The manufacturing method of the peeling film 1 of this embodiment is a base material preparation process which prepares the base material 11; A coating layer forming step of applying a material for forming a release agent layer containing a predetermined component to the first surface 111 of the substrate 11 and drying it to form a coating layer; And a release agent layer forming step of forming the release agent layer 12 by irradiating and curing the applied layer with activating energy rays.

Hereinafter, each process is explained in full detail.

<Material preparation process>

First, the base 11 is prepared.

The first surface 111 of the substrate 11 can be subjected to surface treatment by an oxidation method or the like. Thereby, adhesiveness between the base material 11 and the release agent layer 12 provided in the 1st surface 111 side of the base material 11 can be made especially excellent.

Further, examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone, and ultraviolet irradiation treatment. Such a surface treatment method is appropriately selected according to the type of the substrate 11. In general, the corona discharge treatment method is preferably used in terms of effect and operability.

<Coating layer formation process>

In this step, first, a material for forming a release agent layer is prepared.

A material for forming a release agent layer containing components such as the active energy ray-curable compound (A), polyorganosiloxane (B), and carbon nanomaterial (C) as described above is prepared. The material for forming a release agent layer is obtained by dissolving or dispersing this in a solvent.

Moreover, as a solvent, methanol, ethanol, toluene, ethyl acetate, xylene, methyl ethyl ketone, methyl butyl ketone, isopropyl alcohol, etc. can be used, for example.

Subsequently, on the first surface 111 of the substrate 11, a material for forming a release agent layer forming a liquid phase is applied and dried. Thereby, a coating layer is obtained.

When the material for forming the release agent layer containing the components as described above is used, the unevenness of the first surface 111 of the substrate 11 can be embedded. As a result, the outer surface 121 of the release agent layer 12 can be smoothed.

As a method of applying the material for forming the release agent layer, for example, gravure coating method, bar coating method, spray coating method, spin coating method, air knife coating method, roll coating method, blade coating method, gate roll coating method, die coating And law.

Moreover, although it does not specifically limit as a method of drying the material for forming a release agent layer, For example, the method of drying in a hot air drying furnace etc. are mentioned.

Moreover, it does not specifically limit as drying conditions. The drying temperature is preferably 50 to 100 ° C, and the drying time is preferably 5 seconds to 1 minute. Accordingly, it is possible to prevent undesired deterioration of the coating layer, and also to form the coating layer particularly efficiently. As a result, productivity of the release film 1 finally obtained can be improved. In addition, if the drying temperature is within the above range, when the material for forming the release agent layer contains a solvent or the like, the occurrence of warpage or cracking of the coating layer accompanying evaporation of the solvent or the like during drying is particularly prevented. can do.

<Peeling layer forming process>

Next, the release layer 12 is formed on the coating layer obtained in the coating layer forming step by irradiating and curing an active energy ray.

In this step, in the step of forming the coating layer, the coating layer in which the unevenness of the first surface 111 of the substrate 11 is accurately embedded is cured while maintaining the smoothness of the outer surface 121. As a result, it is possible to obtain the release agent layer 12 whose outer surface 121 is sufficiently smooth. In addition, the release agent layer 12 having a suitable conductivity can be obtained when the material for forming the release agent layer contains the constituent components as described above.

Examples of the active energy ray include infrared rays, visible rays, ultraviolet rays, electromagnetic waves such as X rays, electron beams, ion beams, particle beams such as neutron rays and α rays. Among these, it is preferable to use ultraviolet rays or visible rays, and it is more preferable to be ultraviolet rays. Thereby, the release agent layer 12 can be formed more easily and reliably.

The wavelength of the activated energy ray (ultraviolet ray or visible ray) is not particularly limited, but is preferably 200 to 600 nm, for example, and more preferably 250 to 450 nm. If the wavelength of the activation energy ray is within the above range, the coating layer can be uniformly cured while sufficiently shortening the curing time for curing the coating layer. Further, the means for irradiating the activating energy ray is not particularly limited, and various general means can be used. For example, a light source lamp such as a high pressure mercury lamp, a metal halide lamp, or an excimer lamp can be used as the light source.

In addition, when irradiating an activating energy ray (ultraviolet ray or visible light), the irradiation amount of the activating energy ray is preferably 50 to 400 mJ / cm ² and more preferably 100 to 300 mJ / cm ² . If the irradiation amount of ultraviolet light is within the above range, the coating layer can be cured more uniformly and reliably.

Moreover, although it does not specifically limit as time which irradiates an activating energy ray, It is preferable that it is for 5 second-1 minute. Accordingly, the release agent layer 12 can be formed particularly efficiently. As a result, productivity of the release film 1 finally obtained can be improved.

According to the above process, the highly reliable release film 1 excellent in smoothness and excellent in antistatic properties can be easily and reliably produced.

In addition, when the green sheet is manufactured using the release film 1, pinholes or the like can be prevented from occurring on the surface of the green sheet.

In addition, as a method of manufacturing a ceramic capacitor using the release film 1, for example, a ceramic powder dispersion slurry is applied to the surface of the release agent layer of the release film, dried to form a green sheet, and then peeled from the release film. A method of forming an electrode on a ceramic sheet obtained by laminating a green sheet to obtain a laminate and firing the laminate is exemplified. As described above, when the ceramic capacitor is formed of the green sheet formed by using the release film 1, a highly reliable ceramic capacitor that prevents the occurrence of problems due to short circuit can be obtained.

In the above, although this invention was demonstrated in detail based on preferable embodiment, this invention is not limited to this.

For example, in the above-described embodiment, the release film 1 for producing a green sheet in which the release agent layer 12 is formed on the first surface 111 of the substrate 11 has been described. However, the release film 1 for producing a green sheet is not limited to this, and an intermediate layer may be formed between the substrate 11 and the release agent layer 12. Such an intermediate layer may improve adhesion between the base material 11 and the release agent layer 12.

The composition of the release film for producing a green sheet of the present invention can be replaced with any configuration capable of exerting similar functions, or an arbitrary configuration may be added.

For example, in the above-described embodiment, although the substrate is described as having a single-layer structure, the present invention is not limited to this, and the substrate may have a multilayer structure of two or more layers of the same or different types. In addition, although the release agent layer was similarly described as having a single-layer structure, the present invention is not limited to this, and the release agent layer may have a multilayer structure of two or more layers of the same or different types.

In addition, for example, in the above-described embodiment, the release film for producing a green sheet having a release agent layer formed on the first surface of the substrate was described. However, the release film for producing a green sheet is not limited to this, and a release agent layer may be formed on the second side of the substrate.

In addition, the manufacturing method of the release film for green sheet manufacture of this invention is not limited to the method mentioned above, and arbitrary processes may be added as needed.

Example

Next, specific examples of the release film for producing a green sheet of the present invention will be described, but the present invention is not limited to these examples.

[1] Preparation of release film for green sheet production

(Example 1)

First, a biaxially stretched polyethylene terephthalate film as a substrate (thickness: 31 µm, arithmetic mean roughness Ra ₀ : 29 nm on the first side, maximum projection height Rp ₀ : 257 nm on the first side, arithmetic mean roughness Ra _{2 on} the second side _: 29 nm, maximum projection height Rp ₂ : 257 nm of the second side) was prepared.

Next, 94.05 mass% of dipentaerythritol hexaacrylate (100 mass% of solid content) as the active energy ray-curable compound (A), and polydimethylsiloxane containing polyether-modified acryloyl group as polyorganosiloxane (B) (BYK BICCHEMI CORPORATION, product name “BYK-3500”, solid content 100 mass%) 0.95 mass%, and carbon nanomaterial (C), multi-layer carbon nanotubes (Pilsen Corporation, product name “FM-ML-1 / 25”) , Fiber diameter of about 10nm, aspect ratio 500 to 1500) 0.24% by mass, and α-aminoalkylphenone-based photopolymerization initiator as photopolymerization initiator (D) (manufactured by BASF, trade name “IRGACURE907”, 2-methyl-1 [4- (methyl) Thio) Phenyl] -2-morpholinopropan-1-one, solid content 100 mass%) Diluted 4.76 mass% with isopropyl alcohol / methyl ethyl ketone mixed solvent (mass ratio 3/1) to remove solid content of 20 mass% A layer forming material was obtained.

The obtained release agent layer forming material was applied to the first surface of the substrate with a bar coater. The material for forming the release agent layer was dried at 80 ° C. for 1 minute, and then irradiated with ultraviolet rays (integrated light amount: 250 mJ / cm ² ) to form a release agent layer (thickness: 0.97 μm) to obtain a release film for green sheet production.

(Examples 2 and 3)

A release film for producing a green sheet was produced in the same manner as in Example 1 except that the thickness of the release agent layer was changed as shown in Table 1.

(Example 4)

A release film was produced in the same manner as in Example 1 except that the mass ratios of the active energy ray-curable compound (A) and the polyorganosiloxane (B) in the release agent layer-forming material were changed as shown in Table 1.

(Examples 5 and 6)

A release film was produced in the same manner as in Example 1 except that the mass ratios of the active energy ray-curable compound (A) and the carbon nanomaterial (C) were changed as shown in Table 1.

(Example 7)

The substrate was biaxially stretched polyethylene terephthalate film (thickness: 38 µm, arithmetic mean roughness Ra ₀ : 15 nm on the first side, maximum projection height Rp ₀ : 98 nm on the first side, arithmetic mean roughness Ra _{2 on} the second side): A peeling film was produced in the same manner as in Example 1 except that 15 nm, the maximum protrusion height of the second surface Rp ₂ : 98 nm) was changed.

(Example 8)

A release film was produced in the same manner as in Example 1 except that the thickness of the release agent layer was changed as shown in Table 1.

(Example 9)

The substrate was biaxially stretched polyethylene terephthalate film (thickness: 31 µm, arithmetic mean roughness Ra ₀ : 7 nm on the first side, maximum projection height Rp ₀ : 43 nm on the first side, arithmetic mean roughness Ra _{2 on} the second side): A peeling film was produced in the same manner as in Example 1, except that it was changed to 34 nm and the maximum projection height Rp ₂ : 250 nm of the second surface.

(Comparative Example 1)

A release film was produced in the same manner as in Example 1 except that the mass ratios of the active energy ray-curable compound (A) and the polyorganosiloxane (B) with respect to the release agent layer-forming material were changed as shown in Table 1.

(Comparative Examples 2 and 3)

A release film was produced in the same manner as in Example 1 except that the thickness of the release agent layer was changed as shown in Table 1.

(Comparative Example 4)

A release film was produced in the same manner as in Example 1 except that the mass ratios of the active energy ray-curable compound (A) and the carbon nanomaterial (C) were changed as shown in Table 1.

(Comparative Example 5)

As a release agent, thermosetting silicone (Shin-Etsu Chemical Co., KS-847 H, 30% by mass solid content) was 99.72% by mass as a solid content, and as a carbon nanomaterial (C), a multi-layered carbon nanotube (Pilsen, product name “FM-ML-1 / 25 ”, fiber diameter of about 10 nm, aspect ratio 500 to 1500) 0.24 mass% was diluted with toluene to obtain a diluent. A platinum catalyst (manufactured by Shin-Etsu Chemical Co., CAT-PL-50T, 2% by mass solid content) was mixed as 0.04% by mass as a solid content, and a release agent solution having a solid content of 5.0% by mass was prepared.

The obtained release agent solution was uniformly applied to one surface (first surface) of the same substrate as in Example 1 so that the thickness of the release agent layer formed after drying was 0.3 µm. The release agent solution was dried at 140 ° C for 1 minute to form a release agent layer, which was used as a release film.

(Comparative Examples 6 and 7)

A release film was produced in the same manner as in Comparative Example 5, except that the thickness of the release agent layer was changed as shown in Table 1.

(Comparative Example 8)

A release film for producing a green sheet was produced in the same manner as in Example 1 except that the following materials were used as the release agent layer forming material.

94.05% by mass of dipentaerythritol hexaacrylate (100% by mass of solid content) as the active energy ray-curable compound (A), and polydimethylsiloxane containing polyether-modified acryloyl group as polyorganosiloxane (B) (manufactured by BYK BICCHEMI , Product name “BYK-3500”, solid content 100 mass%) 0.95 mass%, needle antimony dope tin oxide (manufactured by Ishihara Industries, product name “FS-10P”, fiber diameter 10 to 20 nm, aspect ratio : 20 to 30) 0.24 mass% and α-aminoalkylphenone-based photopolymerization initiator as photopolymerization initiator (D) (manufactured by BASF, trade name “IRGACURE907”, 2-methyl-1 [4- (methylthio) phenyl] -2- Morpholinopropane-1-one, solid content 100 mass%) 4.76 mass% was diluted with a mixed solvent of isopropyl alcohol / methyl ethyl ketone (mass ratio 3/1) to obtain a material for forming a release agent layer having a solid content of 20 mass%.

(Comparative Example 9)

A release film for producing a green sheet was produced in the same manner as in Example 1 except that the following materials were used as the release agent layer forming material.

94.05% by mass of dipentaerythritol hexaacrylate (100% by mass of solid content) as the active energy ray-curable compound (A), and polydimethylsiloxane containing polyether-modified acryloyl group as polyorganosiloxane (B) (manufactured by BYK BICCHEMI , Product name “BYK-3500”, solid content 100% by mass) 0.95% by mass, and a needle-like conductive material coated with rutile type titanium oxide with antimony dope tin oxide (manufactured by Ishihara Industries, product name “FT-1000”, fiber About 130 nm in diameter, aspect ratio: 10 to 20) 0.24% by mass, and α-aminoalkylphenone-based photopolymerization initiator as photopolymerization initiator (D) (manufactured by BASF, trade name “IRGACURE907”, 2-methyl-1 [4- (methyl thio) ) Phenyl] -2-morpholinopropan-1-one, solid content 100 mass%) Diluted 4.76 mass% with a mixed solvent of isopropyl alcohol / methyl ethyl ketone (mass ratio 3/1), and a release agent layer having a solid content of 20 mass% The forming material was obtained.

Table 1 summarizes the configuration of the release film for producing the green sheet of each example and each comparative example.

Also in the table, dipentaerythritol hexaacrylate (100% by mass of solid content) as the active energy ray-curable compound (A) is "A", polydimethyl-modified acryloyl group-containing polydimethyl siloxane as polyorganosiloxane (B) (BYK BIC Chemical, product name “BYK-3500”, solid content 100 mass%) is “B”, multilayer carbon nano tube as carbon nano material (C) (product name “FM-ML-1 / 25” manufactured by Pilsen Industries, Ltd.), Fiber diameter of about 10 nm, aspect ratio 500 to 1500) is “C”, α-aminoalkylphenone-based photopolymerization initiator as photopolymerization initiator (D) (trade name, “IRGACURE907” manufactured by BASF, 2-methyl-1 [4- (methylthio) ) Phenyl] -2-morpholinopropan-1-one, solid content 100% by mass) “D”, thermosetting silicone (Shin-Etsu Chemical Co., KS-847H, solid content 30% by mass) “X1”, platinum catalyst (Shin-Etsu) Chemical Industry Co., Ltd., CAT-PL-50 T, solid content 2% by mass) “Y1”, needle antimony dope tin oxide (Ishi) D Industrial Co., Ltd., product name “FS-10 P”, fiber diameter 10 ~ 20nm, aspect ratio: 20 ~ 30) “Z1”, acicular conductive material coated with rutile type needle titanium oxide with antimony dope tin oxide ( Ishihara Industries Co., Ltd., product name "FT-1000", fiber diameter of about 130nm, aspect ratio: 10-20) is indicated as "Z2".

In addition, the thickness of the base material and release agent layer of each Example and each comparative example was measured using the reflective thickness measuring system "F20" (made by Philmetrics Co., Ltd.), respectively. Specifically, the release film for producing the green sheet obtained in each of Examples and Comparative Examples was cut to a size of 100 × 100 mm. Then, the release film for green sheet manufacture was installed in the thickness measuring system so that the surface opposite to the surface on the side where the thickness is measured is the suction stage side. The thickness was measured for 10 sites on the surface of the release agent layer, and the average value was calculated. The average value was taken as the thickness of the release agent layer.

In addition, the arithmetic mean roughness Ra ₀ of the first side of the substrate and the maximum projection height Rp ₀ , the arithmetic mean roughness Ra ₂ of the second side of the substrate And maximum protrusion height Rp ₂ , arithmetic mean roughness Ra ₁ of the outer surface of the release agent layer And the maximum projection height Rp ₁ was measured as follows, respectively. First, a double-sided tape was attached to the glass plate. Next, on the double-sided tape, the surface for measuring the arithmetic mean roughness and maximum protrusion was placed on the top, and the release film for producing the green sheet obtained in each of the Examples and Comparative Examples was fixed. In this way, the arithmetic mean roughness Ra ₀ , Ra ₂ , Ra ₁ , and the maximum protrusion heights Rp ₀ , Rp ₂ , and Rp ₁ are measured by Mitsutoyo surface roughness measuring instrument SV3000S4 (tactile type) according to JIS B0601-1994. did.

[2] Evaluation

The following evaluation was performed about the release film for green sheet manufacture obtained as mentioned above.

[2.1] Surface resistivity

The release film for producing the green sheet obtained in each of the Examples and Comparative Examples was cut to 100 mm × 100 mm, and this was used as a sample. The sample was controlled for 24 hours under conditions of 23 ° C and 50% humidity. Thereafter, “R12704 resistance chamber” manufactured by Advantest and “Digital Electrometer R8252” manufactured by Advantest were used, and the surface resistivity of the release agent layer side was measured according to JIS K6911 (1995).

[2.2] Evaluation of curability of the release agent layer

With respect to the release film for producing the green sheet obtained in each of the Examples and Comparative Examples, the surface of the release agent layer was loaded with a weight of 1 kg / cm ² by a Wes (BEMCOT AP-2, manufactured by Oz Industry Co., Ltd.) containing 3 ml of methyl ethyl ketone. It was polished 10 times in a round trip. Then, the surface of the release agent layer was visually observed, and the curability of the release agent layer was evaluated based on the following judgment criteria.

A: There is no dissolution or dropping of the release agent layer.

B: Dissolution was observed in a part of the release agent layer.

C: The release agent layer was completely dissolved and detached from the substrate.

[2.3] Curl evaluation

The release film for producing the green sheet obtained in each example and each comparative example was cut to 200 × 200 mm. Thereafter, a release film for producing a green sheet was placed on a flat glass plate so that the substrate was on the glass plate side. Subsequently, a 100 × 100 mm glass plate was placed in the center on the release agent layer of the release film for green sheet production. Then, the height from the upper surface of the lower glass plate to the apex of each corner of the release film was measured, and curl was evaluated according to the following criteria.

A: The total sum of the heights of each corner is less than 50 mm.

B: The total sum of the heights of each corner is 50 mm or more and less than 100 mm.

C: The total sum of the heights of each corner is 100 mm or more.

[2.4] Blocking property evaluation

The peeling film for green sheet manufacture obtained in each Example and each comparative example was wound up to 400 mm in width and 5000 m in length to obtain a peeling film roll. This release film roll was stored for 30 days in an environment of 40 ° C and a humidity of 50% or less. Thereafter, the appearance in the state of the release film roll was visually observed, and the blocking property was evaluated according to the following judgment criteria.

A: Compared to the appearance of the release film roll before storage obtained by rolling up the release film for producing a green sheet in a roll shape, the release film roll after storage There was no change in appearance (no blocking).

B: In the area of less than half in the width direction of the release film roll for producing a green sheet, a change in color tone due to adhesion between the films was observed (with some blocking).

C: A change in the color tone due to adhesion between the films was observed over a majority area in the width direction of the release film roll for green sheet production (with blocking).

[2.5] Unloading charge amount

The release film for green sheet production obtained in each example and each comparative example was wound up in a roll shape of 400 mm in width and 5000 m in length to obtain a release film roll. This release film roll was stored for 30 days in an environment of 40 ° C and a humidity of 50% or less. Thereafter, the charge amount when rewinding the release film at 50 m / min was measured using “KSD-0103” manufactured by Kasuga Electric Corporation. The charge amount was measured every 500 M of unwinding length for a 100 mm portion immediately after unwinding of the release film.

A: The charge amount is ± 5 kV or less.

B: The charge amount is ± 5 to 10 kV.

C: The charge amount is more than ± 10 kV.

[2.6] Slurry coatability evaluation

Barium titanate powder (BaTiO ₃ ; manufactured by Sakai Chemical Industry Co., BT-03) 100 parts by mass, 8 parts by mass of polyvinyl butyral (Sekisui Chemical Industry Co., Ltd., Srek BK KM-2), and phthalic acid as a plasticizer To 4 parts by mass of dioctyl (manufactured by Kanto Chemical, dioctyl phthalate purity grade 1), 135 parts by mass of a mixed solution of toluene and ethanol (mass ratio 6: 4) was added. A ceramic slurry was prepared by mixing and dispersing such a substance in a ball mill.

On the surface of the release agent layer of the release film for green sheet production obtained in each of the Examples and Comparative Examples, the ceramic slurry was coated with a die coater so that the thickness after drying was 1 µm, width of 250 mm, and length of 10 m, and the coating layer was applied. Got. Thereafter, the coating layer was dried at 80 ° C for 1 minute in a dryer to obtain a release film for producing a green sheet in which a ceramic green sheet was molded. The fluorescent lamp was irradiated from the release film side for green sheet manufacture with respect to the release film for green sheet manufacture in which the ceramic green sheet was molded. In this way, all the coated ceramic green sheet surfaces were visually observed. The slurry coating property was evaluated on the following judgment criteria. Table 2 shows the results.

A: There was no pinhole in the ceramic green sheet.

B: 1 to 5 pinholes were generated in the ceramic green sheet.

C: Six or more pinholes were generated in the ceramic green sheet.

[2.7] Peelability evaluation

The ceramic green sheet molded on the surface of the release agent layer of the release film for green sheet production in the same manner as in [2.6] above was punched to a size of 200 mm × 200 mm so as not to punch the release film for green sheet production. Subsequently, the punched ceramic green sheet was adsorbed to a vacuum suction stage using the sheet peeling mechanism of the green sheet laminator, and peeled from the release film for green sheet production. The peelability of the ceramic green sheet at this time was evaluated based on the following judgment criteria.

A: The ceramic green sheet is not torn, and it can be gently peeled from the release agent layer, and no ceramic green sheet remains on the release agent layer.

B: The ceramic green sheet is not torn, and it lacks a little smoothness, but can be peeled off the release agent layer, and no ceramic green sheet remains on the release agent layer.

C: The ceramic green sheet was torn or could not be peeled off the release agent layer.

[2.8] Defect evaluation on the surface of the release agent layer (evaluation of iron parts)

The coating solution obtained by dissolving the polyvinyl butyral resin in a mixed solution of toluene and ethanol (mass ratio 6: 4) was placed on the release agent layer of the release film for green sheet production obtained in each example and each comparative example so that the thickness after drying was 1 µm. , And applied to obtain a coating layer. The coating layer was dried at 80 ° C for 1 minute, and a polyvinyl butyral resin layer was molded. Then, a polyester tape was applied to the surface of the polyvinyl butyral resin layer.

Next, using a polyester tape, the release film for green sheet production was peeled off from the polyvinyl butyral resin layer, and the recessed portion on the surface of the polyvinyl butyral resin layer in contact with the release agent layer of the green sheet production release film was removed. Counted. Specifically, the surface of the polyvinyl butyral resin layer was observed at 50 magnification in PSI mode using an optical interference type surface shape observation device (WYKO-1100 manufactured by Veeco). Based on the surface shape image in the range of 91.2 x 119.8 µm of the surface of the polyvinyl butyral resin layer, the number of recesses was counted. The concave portion had a depth of 150 nm or more. The number of concave portions was evaluated according to the following judgment criteria, and defect evaluation on the surface of the release agent layer was performed. In addition, in the above-mentioned peelability evaluation, this evaluation was not performed because the release film for producing a green sheet having a criterion of “C” was not a release film for producing a green sheet satisfactory in performing this evaluation.

A: The number of recesses is 0.

B: The number of recesses is 1-5.

C: The number of recesses is 6 or more.

In addition, when the capacitor is manufactured using the polyvinyl butyral resin layer (ceramic green sheet) in which the above-described concave portion is present, the resulting capacitor is prone to short circuit due to a withstand voltage drop.

Table 2 shows the results.

As is evident from Table 2, the release film for producing the green sheet of the present invention had excellent smoothness on the other surface. In addition, in the release film for producing a green sheet of the present invention, the charge amount was relatively low and the blocking property was excellent. Moreover, the release film for green sheet manufacture of this invention was excellent in the peelability with respect to a green sheet. In addition, no pinholes were observed in the green sheet formed using the release film for producing a green sheet of the present invention. On the other hand, satisfactory results were not obtained in the comparative example.

1: release film for green sheet production
11: description
111: first side of the substrate
112: second side of the substrate
12: release agent layer
121: outer surface of the release agent layer

Claims (5)

It is a release film for green sheet production,
A substrate having a first surface and a second surface; And
And a release agent layer formed on the first surface of the substrate,
The release agent layer is for forming a release agent layer containing an active energy ray-curable compound (A) having three or more (meth) acryloyl groups in one molecule, a polyorganosiloxane (B), and a carbon nanomaterial (C). The coating layer formed by applying the material to the first surface is formed by irradiating active energy rays,
The release film for green sheet production, characterized in that the arithmetic average roughness Ra ₁ of the outer surface of the release agent layer is 8 nm or less, and the maximum protrusion height Rp ₁ of the outer surface of the release agent layer is 50 nm or less. According to claim 1,
The release film for green sheet production, characterized in that the average thickness of the release agent layer is 0.2 to 2㎛. According to claim 1,
A release film for producing a green sheet, wherein the content of the polyorganosiloxane (B) in terms of solid content in the material for forming the release agent layer is 0.5 to 5% by mass. According to claim 1,
The polyorganosiloxane (B) is a polyorganosiloxane having a linear or branched molecular chain, and the terminal and / or side chains of the molecular chain contain silicon atoms, and (meth) acryloyl groups, alkenyl groups, and Malay A release film for producing a green sheet, wherein the reactive functional group having at least one member selected from the group consisting of a mid group is bonded to the silicon atom in the molecular chain through a direct or divalent linking group. The method according to any one of claims 1 to 4,
The release film for green sheet production, characterized in that the content of the carbon nanomaterial (C) in terms of solid content in the release agent layer forming material is 0.05 to 10% by mass.

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