JP2014189007A - Release film for green sheet production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a release film for green sheet production which prevents occurrence of pinholes and partial scattering of thickness on the green sheet surface and can produce a green sheet of high reliability; and to provide a method for producing the same.SOLUTION: A release film for gree sheet production comprises: a substrate; and a release agent layer. The release layer is formed by irradiating a coating layer with active energy rays, the coating layer being formed by coating on a first surface side a release agent layer-forming material containing an active energy ray-curable compound (A) having at least one reactive functional group selected from a (meth)acryloyl group, an alkenyl group, and a maleimide group, a polyorganosiloxane (B), and a carbon nano material (C). An arithmetic average roughness Ra of the outer surface of the release agent layer is 8 nm or less and a maximum protrusion height Ppis 50 nm or less.

Description

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

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

  The release film is generally composed of a substrate and a release agent layer. The green sheet is manufactured by applying and drying a ceramic slurry in which ceramic particles and a binder resin are dispersed and dissolved in an organic solvent on such a release film. Moreover, the manufactured green sheet peels from a peeling film, and is used for manufacture of a ceramic capacitor.

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

  Then, the trial which reduces the influence of the unevenness | corrugation with respect to a green sheet by suppressing the unevenness | corrugation of the peeling film surface as much as possible has been performed (for example, refer patent document 1).

  However, with the recent miniaturization and higher density of ceramic capacitors, further reduction in the thickness of green sheets has been demanded, and conventional release films have not been able to cope with the reduction in thickness. That is, when trying to form a thin green sheet, it has been difficult for the conventional release film to prevent the occurrence of pinholes and the like caused by the unevenness on the surface of the release film being transferred to the green sheet.

  Further, the release film is generally stored and transported in a roll-shaped state, and is used by being unrolled from the roll-shaped state when forming a green sheet. Conventionally, when unwinding the wound release film, static electricity is generated on the surface of the release film, and there is a problem that foreign matters such as dust adhere to the generated static electricity. For this reason, when it tried to manufacture a green sheet using a peeling film, there existed a problem that a pinhole would generate | occur | produce in a green sheet by this adhering foreign material. In particular, the smaller the unevenness on the surface of the release film, the more remarkable the generation of static electricity as described above.

JP 2003-203822 A

  An object of the present invention is to provide a release film for producing a green sheet that can prevent the occurrence of pinholes and partial thickness variations on the surface of the green sheet and can produce a highly reliable green sheet. There is to do.

Such an object is achieved by the present inventions (1) to (5) below.
(1) A release film for producing a green sheet used for producing a green sheet,
A substrate having a first surface and a second surface;
A release agent layer provided on the first surface of the substrate;
The release agent layer comprises an active energy ray-curable compound (A) having at least one reactive functional group selected from the group consisting of a (meth) acryloyl group, an alkenyl group and a maleimide group, and a polyorganosiloxane (B ) And a carbon nanomaterial (C) is applied to the coating layer formed by applying a release agent layer forming material on the first surface side and irradiated with active energy rays. ,
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. Release film.

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

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

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

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

  ADVANTAGE OF THE INVENTION According to this invention, while being excellent in the smoothness of the outer surface of a releasing agent layer, the peeling film for green sheet manufacture provided with the outstanding antistatic property and peelability can be provided. Thereby, it can prevent that the unevenness | corrugation of the peeling film surface for green sheet manufacture transfers to a green sheet. As a result, it is possible to prevent the occurrence of pinholes and partial thickness variations on the surface of the green sheet.

  Moreover, the release film for producing the green sheet of the present invention has appropriate conductivity. For this reason, the resistance value of the surface of the release film for producing a green sheet can be lowered. Thereby, it can suppress that static electricity generate | occur | produces when unwinding the peeling film for green sheet manufacture wound up. As a result, it is possible to prevent foreign matters such as dust from adhering to the surface of the release film for manufacturing the green sheet, so that the slurry repels when the ceramic slurry is applied, and there is a pinhole on the surface of the manufactured green sheet. Can be prevented from occurring. In addition, when the green sheet is peeled off, it is possible to prevent a peeling failure due to charging and the like from occurring, and it is possible to prevent the green sheet from being damaged or wrinkled.

It 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 manufacturing≫
The release film for producing a green sheet of the present invention is used for producing a green sheet. And the manufactured green sheet is used for manufacture of a ceramic capacitor etc., for example.

  FIG. 1 is a cross-sectional view of a release film for producing a green sheet of the present invention. In the following description, the upper side in FIG. 1 is referred to as “upper” and the lower side is referred to as “lower”.

  As shown in FIG. 1, the release film 1 for producing a green sheet includes a base material 11 having a first surface 111 and a second surface 112, and a release provided on the first surface 111 of the base material 11. And an agent layer 12. That is, as shown in FIG. 1, the release film 1 for producing a green sheet has a two-layer structure in which a base material 11 and a release agent layer 12 are laminated so as to be joined to each other in this order.

  In addition, in this specification, when manufacturing a green sheet using the release film for manufacturing a green sheet, the green sheet is applied with, for example, a ceramic slurry dissolved on the outer surface 121 of the release agent layer 12. Formed with.

In the present invention, the release film for producing a green sheet has a substrate and a release agent layer. The release film for producing a green sheet comprises an active energy ray-curable compound (A) having a predetermined reactive functional group, a polyorganosiloxane (B), and a carbon nanomaterial (C). It is formed by applying the release agent layer forming material contained on the first surface side of the substrate and irradiating active energy rays, and the arithmetic average roughness Ra ₁ of the outer surface of the release agent layer is 8 nm. And the maximum protrusion height Rp ₁ on the outer surface is 50 nm or less.

  By having such characteristics, it is possible to obtain a release film for producing a green sheet that is excellent in the smoothness of the outer surface of the release agent layer and has antistatic properties and releasability. And if a green sheet is manufactured using this release film for green sheet manufacture, it can prevent that the pinhole, the dispersion | variation in partial thickness, etc. generate | occur | produce on the surface of a green sheet.

  In particular, the release agent layer has moderate conductivity due to the action of the carbon nanomaterial (C). For this reason, the resistance value of the surface of the release film for producing a green sheet can be lowered. Thereby, it can suppress that static electricity generate | occur | produces when unwinding the peeling film for green sheet manufacture wound up. As a result, it is possible to prevent foreign matters such as dust from adhering to the surface of the release film for producing a green sheet, and it is possible to prevent the occurrence of pinholes due to the attached foreign matter.

  Further, the release agent layer exhibits excellent peelability due to the action of the polyorganosiloxane (B). For this reason, the release agent layer peels the green sheet from the release film for producing the green sheet by the synergistic effect of the release property by the action of the polyorganosiloxane (B) and the antistatic property by the action of the carbon nanomaterial (C). In this case, it is possible to prevent the green sheet from being damaged or wrinkled.

  Moreover, the release agent layer forming material containing the active energy ray-curable compound (A) having a predetermined reactive functional group has appropriate fluidity and shape retention. For this reason, if the release agent layer comprised with this release agent layer forming material is used, the unevenness | corrugation of a base material can be embedded easily. Moreover, the embedded state can be reliably held. As a result, the outer surface of the release agent layer is excellent in smoothness. For this reason, generation | occurrence | production of the pinhole etc. which arise by transferring the uneven | corrugated shape of the outer surface of a releasing agent layer to the formed green sheet can be prevented.

Further, since the arithmetic average roughness Ra ₁ and the maximum protrusion height Rp ₁ of the outer surface of the release agent layer are as described above, for example, even when a thin green sheet of less than 1 μm is manufactured, the release agent It is possible to prevent the irregularities on the outer surface of the layer from being transferred to the green sheet. Thereby, it is possible to obtain a highly reliable green sheet in which the occurrence of pinholes or the like is prevented on the surface of the green sheet.

  Hereinafter, each layer which comprises the peeling film 1 for green sheet manufacture which concerns on this embodiment is demonstrated one by one.

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

As shown in FIG. 1, the base material 11 has a first surface 111 and a second surface 112.
The material constituting the substrate 11 is not particularly limited, and examples thereof include polyester resins such as polybutylene terephthalate resin, polyethylene terephthalate resin and polyethylene naphthalate resin, polyolefin resins such as polypropylene resin and polymethylpentene resin, and polycarbonate. Examples thereof include a film made of plastic, and may be a single layer film or a multilayer film of two or more layers of the same type or different types. Among these, a polyester film is particularly preferable, and a biaxially stretched polyethylene terephthalate film is more preferable. In particular, the polyester film is less prone to dust and the like during its processing and use. Therefore, for example, when a green sheet is manufactured using the release film 1 manufactured 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 and the like can be manufactured.

  In addition to the above materials, the base material 11 may contain a filler or the like. Examples of the filler include silica, titanium oxide, calcium carbonate, kaolin, aluminum oxide, and the like, and one or more of these can be used in combination. By including such a filler, the mechanical strength of the base material 11 can be imparted, the slipperiness of the front and back surfaces can be improved, and blocking can be suppressed.

Further, the substrate 11 is preferably an arithmetic mean roughness Ra ₀ of the first surface 111 is 2 to 80 nm, the arithmetic mean roughness Ra ₀ of the first surface 111, that is 5~50nm More preferred. Thereby, as will be described later, since the release agent layer 12 smoothed by filling the unevenness of the first surface 111 is formed on the first surface 111 of the base material 11, the arithmetic average roughness Ra. _{If 0} is within the above range, the smoothing action is particularly remarkable.

Further, when the arithmetic average roughness Ra ₀ of the first surface 111 exceeds the upper limit value, depending on the constituent material of the release agent layer forming material and the like, peeling may occur in order to sufficiently fill the unevenness of the first surface 111. It may be necessary to make the film thickness of the agent layer 12 relatively large.

The maximum projection height Rp ₀ of the first surface 111 is preferably an 10～700Nm, maximum projection height Rp ₀ of the first surface 111 is preferably more and 20 to 500 nm. Thereby, as will be described later, since the release agent layer 12 smoothed by filling the unevenness of the first surface 111 is formed on the first surface 111 of the substrate 11, the maximum protrusion height Rp is formed. _{If 0} is within the above range, the smoothing action is particularly remarkable.

Further, the substrate 11 is preferably an arithmetic average roughness Ra ₂ of the second surface 112 is 5 to 40 nm, the arithmetic mean roughness Ra ₂ of the second surface 112 is more in the range of 10~30nm preferable. The maximum projection height Rp ₂ of the second surface 112 of the substrate 11 is preferably 60～500Nm. Thus, when the release film 1 having a highly smooth outer surface 121 of the release agent layer 12 is wound around a core material made of paper, plastic, metal, or the like in a roll shape, air escape is improved, Since the shift can be effectively suppressed, there is no need to increase the winding tension, and deformation of the winding core portion due to the winding tension can be suppressed. Further, when the roll-shaped release film 1 is fed out, blocking can be prevented from occurring on the front and back of the rolled 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. It is possible to prevent the occurrence of pinholes and partial thickness variations. As a result, a highly reliable green sheet can be formed.

In contrast, if the maximum projection height Rp ₂ is less than the lower limit value, during storage of the green sheet (thin film) formed before the peeling film 1, when winding the release film 1 before the green sheet formation, Since it is easy to entrain air and miswinding easily occurs, handling becomes difficult. Moreover, the base material 11 and the release agent layer 12 are in close contact with each other, and it is difficult to sufficiently prevent blocking. On the other hand, if the maximum projection height Rp ₂ exceeds the upper limit, when winding the release film 1 after the green sheet formation, the projection shape of the second surface 112 of the substrate 11 in contact with the green sheet on the green sheet As a result, the green sheet may have pinholes and partial thickness variations, which makes it difficult to sufficiently maintain the smoothness of the green sheet.

Thus, 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 this specification, the arithmetic average roughness Ra ₀ and the maximum protrusion height Rp ₀ of the first surface 111 of the base material 11, the arithmetic average roughness Ra ₂ and the maximum protrusion of the second surface 112 of the base material 11. height Rp ₂ is a value determined by measuring by Mitutoyo surface roughness tester SV3000S4 in compliance with JIS B0601-1994 (stylus). In the present specification, unless otherwise specified, the “arithmetic average roughness and maximum protrusion height” refer to values obtained by measurement as described above.

  Moreover, although the average film thickness of the base material 11 is not specifically limited, It is preferable that it is 10-300 micrometers, and it is more preferable that it is 15-200 micrometers. Thereby, it is possible to make the release film 1 particularly excellent in resistance to tearing, breaking, etc. while making the flexibility of the release film 1 moderate.

<Release layer 12>
The release agent layer 12 is provided on the first surface 111 of the substrate 11.

The release agent layer 12 has a function of imparting peelability and antistatic property to the release film 1.
The release agent layer 12 is a layer formed by irradiating the release agent layer forming material with an active energy ray and curing.

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

  The release agent layer 12 having such a configuration has moderate conductivity. For this reason, the surface resistance value of the outer surface 121 of the release agent layer 12 can be lowered. Thereby, it can suppress that static electricity generate | occur | produces when unwinding the peeling film for green sheet manufacture wound up. As a result, it is possible to prevent foreign matters from adhering to the outer surface 121 of the release agent layer 12, and thus it is possible to prevent pinholes and the like from being generated in the green sheet. In addition, since the ceramic slurry can be prevented from fluctuating or repelling due to charging of the surface of the release agent layer 12, a green sheet with a more uniform film thickness can be formed. Moreover, the release agent layer 12 having such a configuration has releasability in addition to appropriate conductivity. For this reason, when peeling a green sheet, generation | occurrence | production of the peeling defect by charging, etc. can be prevented. As a result, it is possible to prevent the green sheet from being damaged or wrinkled.

Hereinafter, each component of the release agent layer forming material will be described in detail.
In addition, the release agent layer forming material before irradiating the active energy ray exists in an uncured state or a semi-cured state at room temperature.

  Further, such a release agent layer forming material has appropriate fluidity when applied onto the first surface 111 of the substrate 11. Therefore, if such a release agent layer forming material is used, the unevenness of the first surface 111 of the substrate 11 can be easily embedded, and the embedded state can be reliably maintained. As a result, it is possible to prevent the unevenness of the base material 11 from affecting the outer surface 121 side of the release agent layer 12 opposite to the base material 11 and to smooth the outer surface 121 of the release agent layer 12. .

[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 being cured. Thereby, the mechanical strength of the release agent layer 12 can be made more appropriate.

  The active energy ray-curable compound (A) has at least one reactive functional group selected from the group consisting of a (meth) acryloyl group, an alkenyl group, and a maleimide group. In addition, as said alkenyl group, a C2-C10 thing, such as a vinyl group, an allyl group, a propenyl group, a hexenyl group, is illustrated. In particular, it is preferable to have two or more such reactive functional groups in one molecule, and more preferably three or more in one molecule. Thereby, the release agent layer 12 can obtain excellent curability, solvent resistance, and peelability. Moreover, this active energy ray hardening compound (A) has moderate fluidity | liquidity and shape retainability. For this reason, when the release agent layer forming material containing the active energy ray-curable compound (A) is applied on the first surface 111 of the base material 11, the first of the base material 11 is formed by the release agent layer forming material. The unevenness of the surface 111 can be accurately embedded, and the embedded 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 an active energy ray-curable compound (A) is 10 equivalent or more per kg of active energy ray-curable compound (A). Thereby, even when applied as a thin film, the curability can be made particularly excellent.

  Specific examples of the active energy ray-curable compound (A) include dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth). ) Acrylate, pentaerythritol tri (meth) acrylate, and polyfunctional (meth) acrylate such as pentaerythritol tetra (meth) acrylate. Among these, at least one polyfunctional selected from the group consisting of dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, pentaerythritol triacrylate, and pentaerythritol tetraacrylate. It is preferable to use acrylate. Thereby, even when applied as a thin film, the curability can be made particularly excellent.

  The content in terms of solid content of the active energy ray-curable compound (A) in the release agent layer forming material (content ratio in the total solid content excluding the solvent) is preferably 65 to 98.5% by mass, and 71 to 71%. It is more preferable that it is 96.3 mass%.

[Polyorganosiloxane (B)]
The polyorganosiloxane (B) is a component that causes the release agent layer 12 to exhibit release properties.

  The polyorganosiloxane (B) is, for example, a polyorganosiloxane having a linear or branched molecular chain, and a (meth) acryloyl group, a vinyl group and a maleimide are present at the terminal and / or side chain of the molecular chain. It is preferable that the reactive functional group having at least one selected from the group consisting of a group is bonded to the silicon atom in the molecular chain directly or via a divalent linking group. What is necessary is just to have at least one said reactive functional group in 1 molecule.

  Examples of the divalent linking group include an alkylene group, an alkyleneoxy group, an oxy group, an imino group, a carbonyl group, and a divalent linking group obtained by combining them.

  The divalent linking group preferably has 1 to 30 carbon atoms, 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 incorporated and fixed in the cross-linked structure when the active energy ray-curable compound (A) is cured by irradiation with active energy. The transfer transfer of polyorganosiloxane, which is a component of the release agent layer 12, to the green sheet formed on the outer surface 121 side of 12 can be suppressed.

  Moreover, as organic groups other than the reactive functional group which comprises polyorganosiloxane (B), the same or different monovalent hydrocarbon group which does not have an aliphatic unsaturated bond, etc. are mentioned.

  As said hydrocarbon group, a C1-C12 thing is preferable and a C1-C10 thing is more preferable.

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

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

  The content in terms of solid content of the polyorganosiloxane (B) in the release agent layer forming material is preferably 0.5 to 5% by mass, and more preferably 0.7 to 4% by mass. Thereby, it becomes possible to apply without repelling the ceramic slurry, and the peelability of the release film 1 for producing a green sheet can be made particularly excellent.

  In contrast, if the content of the polyorganosiloxane (B) in the release agent layer forming material in terms of solid content is less than the lower limit, depending on the type of the substrate, the formed release agent layer 12 may be There is a possibility that sufficient peelability cannot be exhibited. On the other hand, when the content in terms of solid content of the polyorganosiloxane in the release agent layer forming material exceeds the upper limit, when the ceramic slurry is applied to the surface of the release agent layer 12 to be formed, the constituent material of the ceramic slurry For example, the ceramic slurry may be easily repelled.

  Furthermore, when the content of the active energy ray-curable compound (A) is A part by mass and the amount of the polyorganosiloxane (B) is B part by mass, the mass ratio B / A is 0.7 / 99. A range of 3 to 5/95 is more preferable, and a range of 1/99 to 4.5 / 95.5 is particularly preferable. Thereby, the effect becomes more remarkable.

[Carbon nanomaterial (C)]
The carbon nanomaterial (C) has a function of imparting antistatic properties to the release agent layer 12.

  Examples of the carbon nanomaterial (C) include fullerene, carbon nanotube, carbon nanofiber, carbon nanohorn, and the like, and one or more of these can be used in combination. Among these, carbon nanotubes are particularly preferable. Thereby, more moderate electroconductivity 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 is possible to prevent pinholes from occurring in the green sheet formed on the release agent layer 12.

  In particular, among the carbon nanomaterials (C) as described above, carbon nanotubes are in the form of fibers having a high aspect ratio (long and short). For this reason, the carbon nanotube can be easily oriented so that the fiber length is along the surface direction of the release agent layer 12. Therefore, if carbon nanotubes are used, it is possible to obtain the release agent layer 12 having an appropriate charging property and a smoother outer surface 121.

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

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

  Further, the aspect ratio of the carbon nanomaterial (C) is, for example, preferably 10 to 10,000, more preferably 200 to 5000, and further preferably 400 to 2000. The aspect ratio of the carbon nanomaterial (C) is a value measured by observing the carbon nanotube using a scanning electron microscope (manufactured by Hitachi High-Technologies Corporation, 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 0.2 More preferably, it is ˜1% by mass. When the content of the carbon nanomaterial (C) is less than the lower limit, the surface resistivity of the release agent layer 12 may not be sufficiently reduced. When content of carbon nanomaterial (C) exceeds the said upper limit, the intensity | strength of the releasing agent layer 12 falls and there exists a possibility that solvent resistance may deteriorate.

[Photoinitiator (D)]
In order to cure the release agent layer forming material, the release agent layer forming material may contain a photopolymerization initiator (D). In particular, when ultraviolet rays are used as the active energy rays, the release agent layer forming material can be cured more easily and reliably 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) -aminoalkylphenone type thing. Such an α-aminoalkylphenone-based photopolymerization initiator is a compound that is less susceptible to oxygen inhibition during curing. Therefore, particularly excellent curability can also be obtained in the production of the release film 1 in an air atmosphere.

  Examples of α-aminoalkylphenone-based photopolymerization initiators include 2-methyl-1 [4- (methylthio) 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. Is mentioned. Thereby, especially excellent curability, solvent resistance, and peelability can be obtained.

  The content in terms of solid content of the photopolymerization initiator (D) 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 in a range where it is difficult to obtain curability due to oxygen inhibition, particularly excellent curability, solvent resistance, and peelability can be obtained.

  Further, in such a release film 1, a component derived from the polyorganosiloxane (B) is segregated near the outer surface 121 of the release agent layer 12. Such segregation occurs while the coating layer of the release agent layer forming material is cured by using a polyorganosiloxane (B) having a different molecular structure, polarity, molecular weight and the like from the active energy ray-curable compound (A). It is considered that the polyorganosiloxane (B) is pushed up to the vicinity of the surface.

  Further, the release agent layer forming material may contain other components in addition to the components as previously described. For example, it may contain other components such as a sensitizer, an antistatic agent and a curing agent.

  Examples of the sensitizer include 2,4-diethylthioxanthone and isopropylthioxanthone. Thereby, reactivity can be improved more.

  Moreover, it is preferable that content in solid content conversion of the said other component in the release agent layer forming material is 0-10 mass%.

Further, as described above, the outer surface 121 of the release agent layer 12 is an arithmetic mean roughness Ra ₁ is 8nm or less and a maximum projection height Rp ₁ is 50nm or less. As a result, 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 the green sheet from causing pinholes and partial thickness variations, thereby making the surface of the green sheet more High smoothness can be achieved.

  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 lower limit, the smoothness of the outer surface 121 of the release agent layer 12 becomes insufficient, and when the green sheet is molded on the outer surface 121 side of the release agent layer 12, There is a risk of pinholes and partial thickness variations in the green sheet. On the other hand, when the thickness of the release agent layer 12 exceeds the upper limit, the release film 1 is likely to curl due to cure shrinkage of the release agent layer 12, or the base material 11 in contact with the release film 1 is wound up. Since the second surface 112 and the outer surface 121 of the release agent layer 12 are likely to be blocked, there is a concern that winding failure may occur or the amount of charge during unwinding may increase.

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

  In this specification, the surface resistivity indicates the resistance per unit surface area. The unit of surface resistivity is Ω / □ in this specification.

  The surface resistivity can be measured in accordance with JIS K6911 (1995).

≪Method for producing release film for green sheet production≫
Next, a preferred embodiment of the method for producing 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 coating layer which forms the coating layer by apply | coating and drying the base material preparation process which prepares the base material 11, and the release agent layer forming material containing a predetermined component. A forming step and a release agent layer forming step of forming the release agent layer 12 by irradiating the application layer with an activation energy ray and curing it.

Hereinafter, each step will be described in detail.
<Base material preparation process>
First, the base material 11 is prepared.
The first surface 111 of the substrate 11 can be subjected to a surface treatment by an oxidation method or the like. Thereby, the adhesiveness of 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.

  Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone, ultraviolet irradiation treatment, and the like. The corona discharge treatment method is generally preferably used from the viewpoints of effects and operability.

<Coating layer formation process>
In this step, first, a release agent layer forming material is prepared.

  Prepare a release agent layer forming material containing components such as the active energy ray-curable compound (A), polyorganosiloxane (B), and carbon nanomaterial (C) as described above, and dissolve it in a solvent. Alternatively, a release agent layer forming material is obtained by dispersing.

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

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

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

  Examples of methods for applying the release agent layer forming material include gravure coating, bar coating, spray coating, spin coating, air knife coating, roll coating, blade coating, gate roll coating, and die coating. Law.

  The method for drying the release agent layer forming material is not particularly limited, and examples thereof include a method of drying in a hot air drying furnace.

  Moreover, it is although it does not specifically limit as drying conditions, It is preferable that drying temperature is 50-100 degreeC, and it is preferable that drying time is 5 second-1 minute. Thereby, unintentional alteration of the coating layer can be prevented, and the coating layer can be formed particularly efficiently. As a result, productivity of the finally obtained release film 1 can be improved. In addition, when the drying temperature is within the above range, particularly when the release agent layer forming material contains a solvent or the like, the occurrence of warping or cracking of the coating layer accompanied by evaporation of the solvent or the like during drying is particularly caused. Can be prevented.

<Release agent layer forming step>
Next, the release agent layer 12 is formed by irradiating the application layer obtained in the application layer forming step with an activation energy ray and curing it.

  In this step, the coating layer in which the unevenness of the first surface 111 of the substrate 11 is appropriately embedded in the coating layer forming step is cured while maintaining the smoothness of the outer surface 121. As a result, the release agent layer 12 having a sufficiently smooth outer surface 121 can be obtained. Moreover, when the release agent layer forming material contains the constituent components as described above, the release agent layer 12 having appropriate conductivity can be obtained.

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

  Although it does not specifically limit as a wavelength of an activation energy ray (an ultraviolet ray or visible light), For example, it is preferable that it is 200-600 nm, and it is more preferable that it is 250-450 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. Moreover, it does not specifically limit as a means to irradiate an activation energy ray, A various general means can be utilized. For example, a light source lamp such as a pressure mercury lamp, a metal halide lamp, or an excimer lamp can be used as the light source.

Moreover, when irradiating activation energy rays (ultraviolet rays or visible rays), the irradiation amount of the activation energy rays is preferably 50 to 400 mJ / cm ² , and preferably 100 to 300 mJ / cm ² . More preferably. When the irradiation amount of ultraviolet rays is a value within the above range, the coating layer can be cured more uniformly and reliably.

  The time for irradiating the activation energy ray is not particularly limited, but is preferably 5 seconds to 1 minute. Thereby, the release agent layer 12 can be formed particularly efficiently. As a result, productivity of the finally obtained release film 1 can be improved.

  According to the above process, the reliable peeling film 1 which was excellent in smoothness and excellent in antistatic property can be manufactured easily and reliably.

  Moreover, if a green sheet is manufactured using such a peeling film 1, it can prevent that a pinhole etc. arise on the surface of a 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 and dried to form a green sheet, and then released from the release film. The method of forming the electrode on the ceramic sheet obtained by laminating and firing the obtained green sheets is mentioned. Thus, if a ceramic capacitor is formed with a green sheet formed using the release film 1, a highly reliable ceramic capacitor in which the occurrence of defects due to a short circuit is prevented can be obtained.

  As mentioned above, although this invention was demonstrated in detail based on preferred 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 provided on the first surface 111 of the base material 11 has been described. An intermediate layer may be provided between the two. Such an intermediate layer may improve the adhesion between the substrate 11 and the release agent layer 12.

  The structure of the release film for producing a green sheet of the present invention can be replaced with any film that can exhibit the same function, or can have any structure.

  For example, in the above-described embodiment, the base material has been described as having a single layer structure, but the present invention is not limited to this, and the base material may have a multilayer structure of two or more layers of the same type or different types. Similarly, the release agent layer has been described as having a single layer structure. However, 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 type or different types. .

  In addition, for example, in the above-described embodiment, the release film for producing a green sheet in which the release agent layer is provided on the first surface of the base material has been described. However, the embodiment is not limited thereto, and the second surface side of the base material is provided. A release agent layer may be provided.

  Moreover, the manufacturing method of the peeling film for green sheet manufacture of this invention is not limited to the method mentioned above, Arbitrary processes may be added as needed.

  Next, although the specific Example of the peeling film for green sheet manufacture of this invention is described, this invention is not limited only 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 average roughness Ra ₀ of the first surface: 29 nm, maximum protrusion height Rp _{0 of} 257 nm of the first surface, Arithmetic average roughness Ra ₂ : 29 nm, maximum protrusion height Rp ₂ : 257 nm of the second surface) was prepared.

  Next, 94.05% by mass of dipentaerythritol hexaacrylate (solid content: 100% by mass) as the active energy ray-curable compound (A) and polyether-modified acryloyl group-containing polydimethyl as the polyorganosiloxane (B) 0.95% by mass of siloxane (manufactured by Big Chemie, product name “BYK-3500”, solid content 100% by mass), and carbon nanomaterial (C), multi-walled carbon nanotubes (manufactured by Philgen Co., Ltd., product name “F- M-ML-1 / 25 ", fiber diameter about 10 nm, aspect ratio 500-1500) 0.24 parts by mass, and α-aminoalkylphenone photopolymerization initiator (manufactured by BASF) as a photopolymerization initiator (D) , Trade name “IRGACURE907”, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinop Pan-1-one, solid content 100% by mass) 4.76% by mass diluted with isopropyl alcohol / methyl ethyl ketone mixed solvent (mass ratio 3/1) to give a release agent layer forming material having a solid content of 20% by mass Got.

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

(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 prepared in the same manner as in Example 1 except that the mass ratio of the active energy ray-curable compound (A) and the polyorganosiloxane (B) in the release agent layer forming material was 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 ratio of the active energy ray-curable compound (A) and the carbon nanomaterial (C) was changed as shown in Table 1.

(Example 7)
Biaxially stretched polyethylene terephthalate film (thickness: 38 μm, arithmetic average roughness Ra ₀ of the first surface: 15 nm, maximum protrusion height Rp _{0 of} the first surface: 98 nm, arithmetic average of the second surface A release film was produced in the same manner as in Example 1 except that the roughness Ra _{2 was} 15 nm and the maximum protrusion height Rp _{2 of} the second surface was 98 nm.

(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
Biaxially stretched polyethylene terephthalate film (thickness: 31 μm, first surface arithmetic average roughness Ra ₀ : 7 nm, first surface maximum protrusion height Rp ₀ : 43 nm, second surface arithmetic average A release film was produced in the same manner as in Example 1 except that the roughness Ra _{2 was} 34 nm and the maximum protrusion height Rp _{2 of} the second surface was 250 nm.

(Comparative Example 1)
A release film was prepared in the same manner as in Example 1 except that the mass ratio of the active energy ray-curable compound (A) and the polyorganosiloxane (B) in the release agent layer forming material was 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 ratio of the active energy ray-curable compound (A) and the carbon nanomaterial (C) was changed as shown in Table 1.

(Comparative Example 5)
Thermosetting silicone as release agent (manufactured by Shin-Etsu Chemical Co., Ltd., KS-847H, solid content 30% by mass) as solid content 99.72% by mass, and carbon nanomaterial (C) as multi-walled carbon nanotube (manufactured by Philgen) The product name “F-M-ML-1 / 25”, fiber diameter of about 10 nm, aspect ratio 500-1500) 0.24% by mass was diluted with toluene, and platinum catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., CAT) -PL-50T, solid content 2% by mass) was mixed with 0.04% by mass as a solid content to prepare a release agent solution having a solid content of 5.0% by mass.

  Uniformly apply the obtained release agent solution to one surface (first surface) of the same substrate as in Example 1 so that the thickness of the formed release agent layer after drying is 0.3 μm. And it was made to dry at 140 degreeC for 1 minute, the release agent layer was formed, and this was made into the peeling 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 (solid content: 100% by mass) as the active energy ray-curable compound (A), and polydimethylsiloxane having a polyether-modified acryloyl group as the polyorganosiloxane (B) (Big Chemie) Product name “BYK-3500”, solid content 100% by mass) 0.95% by mass, acicular antimony-doped tin oxide (Ishihara Sangyo Co., Ltd., product name “FS-10P”, fiber diameter 10-20 nm) , Aspect ratio: 20 to 30) 0.24 parts by mass, and α-aminoalkylphenone photopolymerization initiator (trade name “IRGACURE907”, 2-methyl-1 as a photopolymerization initiator (D)) [4- (methylthio) phenyl] -2-morpholinopropan-1-one, solid content 100% by mass) 4.76% by mass , Diluted with isopropyl alcohol / methyl ethyl ketone mixed solvent (weight ratio 3/1), to give a solid content of 20% by weight of the release agent layer forming material.

(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 (solid content: 100% by mass) as the active energy ray-curable compound (A), and polydimethylsiloxane having a polyether-modified acryloyl group as the polyorganosiloxane (B) (Big Chemie) 0.95% by mass, product name “BYK-3500”, solid content 100% by mass), and acicular conductive material in which rutile acicular titanium oxide is coated with antimony-doped tin oxide (product made by Ishihara Sangyo Co., Ltd., product) Name “FT-1000”, fiber diameter of about 130 nm, aspect ratio: 10 to 20) 0.24 parts by mass, α-aminoalkylphenone photopolymerization initiator (manufactured by BASF, as photopolymerization initiator (D), Trade name “IRGACURE907”, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropane-1- Down, and a solid content of 100 mass%) 4.76 mass%, was diluted with isopropyl alcohol / methyl ethyl ketone mixed solvent (weight ratio 3/1), to give a solid content of 20% by weight of the release agent layer forming material.

  Table 1 summarizes the configurations and the like of the release films for producing green sheets of each Example and each Comparative Example.

  In the table, dipentaerythritol hexaacrylate (solid content: 100% by mass) as active energy ray-curable compound (A) is “A”, and polyether-modified acryloyl group-containing polydimethylsiloxane as polyorganosiloxane (B). Multi-walled carbon nanotubes (manufactured by Philgen Corporation, product name “F-M-ML”, product name “BYK-3500”, solid content 100% by mass) (“B”), carbon nanomaterial (C) -1/25 ", fiber diameter of about 10 nm, aspect ratio 500 to 1.500)" C ", α-aminoalkylphenone photopolymerization initiator (trade name, manufactured by BASF) as photopolymerization initiator (D) “IRGACURE907”, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one, solids 00 mass%) “D”, thermosetting silicone (manufactured by Shin-Etsu Chemical Co., Ltd., KS-847H, solid content 30 mass%) is “X1”, platinum catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., CAT-PL-50T, “Y1” for solid content (2% by mass), acicular antimony-doped tin oxide (manufactured by Ishihara Sangyo Co., Ltd., product name “FS-10P”, fiber diameter 10-20 nm, aspect ratio: 20-30) “Z1”, Needle-like conductive material (made by Ishihara Sangyo Co., Ltd., product name “FT-1000”, fiber diameter of about 130 nm, aspect ratio: 10 to 20) coated with antimony-doped tin oxide on rutile needle-like titanium oxide is “Z2”. Indicated.

  In addition, the film thicknesses of the base material and the release agent layer in each Example and each Comparative Example were measured using a reflective film thickness meter “F20” [manufactured by Filmetrics Co., Ltd.]. Specifically, after the green film manufacturing release film obtained in each Example and each Comparative Example was cut to 100 × 100 mm, the green sheet was manufactured so that the surface opposite to the surface to be measured was on the suction stage side The film for release was placed on a film thickness meter, the film thickness was measured at 10 locations on the surface of the release agent layer, and the average value was taken as the thickness of the release agent layer.

Further, the arithmetic average roughness Ra ₀ and the maximum protrusion height Rp ₀ of the first surface of the base material, the arithmetic average roughness Ra ₂ and the maximum protrusion height Rp ₂ of the second surface of the base material, and the release agent layer Arithmetic mean roughness Ra ₁ and maximum protrusion height Rp ₁ of the outer surface are each fixed to JIS B0601-1994 by applying a double-sided tape to a glass plate and fixing the measurement surface on the double-sided tape. The surface roughness was measured with a Mitutoyo surface roughness measuring instrument SV3000S4 (stylus type).

[2] Evaluation Regarding the release film for producing a green sheet obtained as described above, the following evaluation was performed.

[2.1] Surface resistivity The release film for producing a green sheet obtained in each Example and each Comparative Example was cut into 100 mm × 100 mm, and this was used as a sample. After conditioning the sample for 24 hours under the conditions of 23 ° C. and 50% humidity, using “R12704 Resistivity Chamber” manufactured by Advantest and “Digital Electrometer R8252” manufactured by Advantest and complying with JIS K6911 (1995) Then, the resistivity of the surface on the release agent layer side was measured.

[2.2] Curability evaluation of release agent layer About the release film for green sheet production obtained in each Example and each Comparative Example, a waste containing 3 ml of methyl ethyl ketone (BEMCOT AP-2, manufactured by Ozu Sangyo Co., Ltd.) After polishing the surface of the release agent layer 10 times with a load of 1 kg / cm ² , the surface of the release agent layer was visually observed, and the curability of the release agent layer was evaluated according to the following criteria.

A: No release / dissolution of the release agent layer B: Partial dissolution of the release agent layer was observed C: The release agent layer was completely dissolved and dropped from the substrate

[2.3] Curl Evaluation The release film for green sheet production obtained in each Example and each Comparative Example was cut into 200 × 200 mm, and then the release film for green sheet production was so that the substrate was on the glass plate side. Was placed on a flat glass plate. Next, after placing a 100 × 100 mm glass plate at the center on the release agent layer of the release film for green sheet production, the height from the upper surface of the lower glass plate to the corners of the release film was measured. The curl was evaluated according to the following criteria.

A: The sum of the heights of the corners is less than 50 mm B: The sum of the heights of the corners is less than 50 mm and less than 100 mm C: The sum of the heights of the corners is 100 mm or more

[2.4] Evaluation of blocking property The release film for producing green sheets obtained in each Example and each Comparative Example was wound up into a roll having a width of 400 mm and a length of 5000 m 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. The appearance of the release film roll as it was was visually observed, and the blocking property was evaluated according to the following criteria.

A: There was no change from when it was rolled up (no blocking)
B: Change in color due to adhesion between films was observed in an area of less than half in the width direction (some blocking)
C: Over the majority region in the width direction, a change in color due to adhesion between films was observed (with blocking)

[2.5] Unwinding charge amount The release film for producing a green sheet obtained in each example and each comparative example was wound up into a roll having a width of 400 mm and a length of 5000 m to obtain a release film roll. The release film roll was stored in an environment of 40 ° C. and a humidity of 50% or less for 30 days, and the amount of charge when it was rewound at 50 m / min was measured using “KSD-0103” manufactured by Kasuga Denki. The amount of charge was measured every 100 M of unwinding length at a location of 100 mm immediately after unwinding.

A: ± 5 kV or less B: ± 5 to 10 kV
C: Over ± 10kV

[2.6] Slurry coating property evaluation 100 parts by mass of barium titanate powder (BaTiO ₃ ; manufactured by Sakai Chemical Industry Co., Ltd., BT-03), polyvinyl butyral as a binder (manufactured by Sekisui Chemical Co., Ltd., ESREC B · K BM- 2) To 8 parts by mass and 4 parts by mass of dioctyl phthalate (manufactured by Kanto Chemical Co., Inc., dioctyl phthalate deer grade 1) as a plasticizer, 135 parts by mass of a mixed solution of toluene and ethanol (mass ratio 6: 4) was added. The ceramic slurry was prepared by mixing and dispersing in a ball mill.

  250 mm in width and 10 m in length so that the film thickness after drying the ceramic slurry with a die coater is 1 μm on the surface of the release agent layer of the release film for green sheet production obtained in each Example and each Comparative Example. Then, it was dried at 80 ° C. for 1 minute in a dryer. For the green film manufacturing release film on which the ceramic green sheet was molded, illuminate the fluorescent lamp from the green sheet manufacturing release film side, visually inspect all coated ceramic green sheet surfaces, and slurry according to the following criteria The coatability was evaluated. The results are shown in Table 1.

A: There were no pinholes in the ceramic green sheet B: 1-5 pinholes occurred in the ceramic green sheet C: Six or more pinholes occurred in the ceramic green sheet

[2.7] Evaluation of releasability Ceramic green sheets formed on the surface of the release agent layer of the release film for green sheet production by the same procedure as in [2.6] above were not cut out of the release film for green sheet production. Punched to × 200 mm. Next, using the sheet peeling mechanism of the green sheet laminator, the punched ceramic green sheet was adsorbed on a vacuum suction stage and peeled from the release film for green sheet production. The peelability of the ceramic green sheet at this time was evaluated according to the following criteria.

A: The ceramic green sheet can be peeled off smoothly without tearing, and the ceramic green sheet did not remain on the release agent layer. B: The ceramic green sheet could be peeled off slightly without being broken, and on the release agent layer. There was no ceramic green sheet left on the surface. C ... The ceramic green sheet was torn or could not be peeled off.

[2.8] Evaluation of Defect on Surface of Release Agent Layer A coating solution prepared by dissolving polyvinyl butyral resin in a mixed solution of toluene and ethanol (mass ratio 6: 4) was obtained in each Example and each Comparative Example. On the release agent layer of the release film for sheet production, it was applied so that the thickness after drying was 1 μm, and dried at 80 ° C. for 1 minute to form a polyvinyl butyral resin layer. And the polyester tape was stuck on the surface of the polyvinyl butyral resin layer.

  Next, using a polyester tape, the release film for green sheet production was peeled from the polyvinyl butyral resin layer, and the depressions on the surface of the polyvinyl butyral resin layer that had been in contact with the release agent layer of the release film for green sheet production were counted. . Specifically, using a light interference type surface shape observation device (Veeco, WYKO-1100), the surface in the range of 91.2 × 119.8 μm obtained by observing at 50 magnifications in the PSI mode. Based on the shape image, dents with a depth of 150 nm or more were counted, and defects on the surface of the release agent layer were evaluated according to the following criteria. In addition, in the above-described peelability evaluation test, for the case where the evaluation was “C”, a satisfactory sample for performing this test could not be obtained, so this test was not performed.

A: Number of dents is 0 B: Number of dents is 1-5 C: Number of dents is 6 or more

In addition, when a capacitor | condenser is manufactured with the ceramic green sheet in which the above dents exist, the capacitor | condenser obtained becomes what becomes easy to generate | occur | produce a short circuit by a withstand voltage fall.
These results are shown in Table 2.

  As is clear from Table 2, the release film for producing a green sheet of the present invention was excellent in the smoothness of the outer surface. The release film for producing a green sheet of the present invention has a relatively low charge amount and is excellent in blocking properties. In addition, the release film for producing a green sheet of the present invention was excellent in peelability from the green sheet. In addition, no pinholes were observed on the green sheet formed using the release film for producing the green sheet of the present invention. On the other hand, satisfactory results were not obtained in the comparative example.

DESCRIPTION OF SYMBOLS 1 ... Release film 11 for green sheet manufacture ... Base material 111 ... First surface 112 of base material ... Second surface of base material 12 ... Release agent layer 121 ... Release External surface of the agent layer

Claims (5)

A release film for producing a green sheet used for producing a green sheet,
A substrate having a first surface and a second surface;
A release agent layer provided on the first surface of the substrate;
The release agent layer comprises an active energy ray-curable compound (A) having at least one reactive functional group selected from the group consisting of a (meth) acryloyl group, an alkenyl group and a maleimide group, and a polyorganosiloxane (B ) And a carbon nanomaterial (C) is applied to the coating layer formed by applying a release agent layer forming material on the first surface side and irradiated with active energy rays. ,
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. Release film.   The release film for producing a green sheet according to claim 1, wherein an average film thickness of the release agent layer is 0.2 to 2 μm.   The release film for producing a green sheet according to claim 1 or 2, wherein the content of the polyorganosiloxane (B) in the release agent layer forming material in terms of solid content is 0.5 to 5% by mass.   The polyorganosiloxane (B) is a polyorganosiloxane having a linear or branched molecular chain, and has a (meth) acryloyl group, an alkenyl group, and a maleimide group at the terminal and / or side chain of the molecular chain. The reactive functional group having at least one selected from the group consisting of those bonded to a silicon atom in the molecular chain directly or via a divalent linking group. A release film for producing a green sheet according to item.   5. The green sheet manufacturing method according to claim 1, wherein the carbon nanomaterial (C) in the release agent layer forming material has a solid content conversion content of 0.05 to 10% by mass. Release film.

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