JP2009226894A - Release film, and method for manufacturing green sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a release film capable of preventing charging and blocking, and to provide a method for manufacturing a green sheet by which the charging and blocking of the release film can be prevented. <P>SOLUTION: The release film is provided with a belt-like base material, and a release layer mainly containing a release agent. In the vicinity of at least one end of the release film in a width direction, a discharge layer is provided in the longitudinal direction of the release film to remove electricity from the release film. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  Ceramic green sheets (green sheets) used in the manufacture of electronic circuit boards are generally coated on a release film with a green slurry in which ceramic particles and binder resin are dispersed and dissolved in an organic solvent, and the coated product is dried. It is manufactured by doing. In such a method, a green sheet having a uniform thickness can be efficiently produced. Moreover, the green sheet manufactured in this way peels from a peeling film, and is used for manufacture of an electronic circuit board.

  In the method for producing a green sheet as described above, the release film usually has a strip shape. For this reason, at the time of manufacturing the green sheet, the release sheet and the green sheet are stored and transported in a state of being wound in a roll as appropriate. However, the conventional method for producing a green sheet using a release sheet has the following problems.

  That is, static electricity is generated when the release film is unwound from the winding of the release film. Moreover, static electricity is generated when the green sheet is peeled off from the release film after the green slurry is applied on the release film and the green sheet is formed. In such a case, dust adheres to the green sheet or the release film. As a result, the manufactured green sheet has a defect based on this dust. In addition, when such static electricity is generated, there is a problem that feeding of the release film from the winding is not stable.

  Therefore, there has been an attempt to use a release film in which an antistatic layer for removing generated static electricity is provided on the surface opposite to the coated surface of the substrate (for example, see Patent Document 1). However, there is a problem that the green sheet is contaminated by the components contained in the antistatic layer adhering to and permeating the green sheet. Such an antistatic layer is provided on the entire main surface of the substrate. Moreover, the conventional antistatic layer is relatively easy to cause blocking with an adjacent layer. For this reason, when unwinding the release film from the winding of the release film on which the green sheet is formed, there is a problem that it is difficult to stably unwind the release film.

JP 2003-203821 A

  An object of the present invention is to provide a release film that can prevent charging and blocking, and a method for producing a green sheet that can prevent charging and blocking of the release film.

Such an object is achieved by the present inventions (1) to (13) below.
(1) a band-shaped substrate;
A release film provided on the substrate and having a release layer mainly composed of a release agent,
A release film comprising a charge removal layer for removing electricity from the release film provided along the longitudinal direction of the release film in the vicinity of at least one end in the width direction of the release film.

  (2) The release film according to (1), wherein the release film is one that is neutralized by contact between the charge removal layer and an external charge removal unit.

  (3) The release film according to (1) or (2), wherein the charge removal layer is provided on the same side of the substrate as the release layer.

  (4) The release film according to any one of the above (1) to (3), wherein the ratio of the area of the charge removal layer to the area of the release film in a plan view of the release film is 3 to 30%.

  (5) The release film according to any one of (1) to (4), wherein the charge removal layer includes conductive particles.

  (6) The release film according to (5), wherein the conductive particles are carbon nanofibers.

  (7) The release film according to any one of (1) to (6), wherein the charge removal layer includes a conductive polymer material.

  (8) The release film according to any one of (1) to (7), wherein the release film is used by being bonded to a green sheet.

  (9) The release film according to (8), wherein the charge removal layer is provided in a region in contact with the green sheet formed on the release layer.

(10) A green sheet material application step of applying a green sheet material containing ceramic particles and a binder on the release film to form a green sheet precursor;
Solidifying step of solidifying the green sheet precursor,
The release film is a strip-shaped substrate, a release layer provided on the substrate and mainly composed of a release agent, and the longitudinal direction of the release film near at least one end in the width direction of the release film. A method for producing a green sheet, comprising: a neutralization layer that neutralizes the release film provided along the surface.

  (11) The method for producing a green sheet according to (10), wherein the release film is neutralized by contact between the static elimination layer and an external static elimination means.

  (12) The method for producing a green sheet according to (10) or (11), wherein in the green sheet material application step, the release film is neutralized when the green sheet material is applied to the release film.

  (13) The green sheet manufacturing method according to any one of (10) to (12), wherein, in the green sheet applying step, the green sheet precursor is formed so as to be in contact with the charge removal layer.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the peeling film which can prevent charging and blocking, and the green sheet which can prevent charging and blocking of a peeling film can be provided.

The present invention will be described below with reference to the drawings.
[First Embodiment]
≪Release film≫
The release film is used for the production of a green sheet. Generally, a green sheet is formed by applying a coating liquid (green slurry) containing a material for a green sheet on the release film and solidifying it.

  FIG. 1 is a cross-sectional view of a release film according to the first embodiment of the present invention, and FIG. 2 is a plan view of the release film shown in FIG. 3 is a cross-sectional view showing a part of the winding in a state where the release film shown in FIG. 1 is rolled, FIG. 4 is a longitudinal sectional view when the release film is unwound from the winding of FIG. 3, and FIG. FIG. 6 is a cross-sectional view showing a part of a roll in a state where the release film shown in FIG. 1 on which a green sheet is formed is rolled up, and FIG. 6 is a longitudinal cross-sectional view when the release film is unwound from the winding of FIG. is there.

  As shown in FIG. 1 and FIG. 2, the release film 1 is provided on the base material 11, the release layer 12 provided on the base material 11, and the release layer 12, both in the width direction of the release film 1. It has the static elimination layer 13 provided along the longitudinal direction of the peeling film 1 in the edge part. In the green sheet manufacturing method as described later, the green sheet material is applied to the green sheet forming region 14 on the release layer 12, and the green sheet 20 is formed on the release layer 12.

By providing the charge removal layer in this way, the following effects can be obtained.
As shown in FIG. 3, in the winding 30 which wound the peeling film 1 in roll shape, each peeling film 1 is laminated | stacked so that the static elimination layer 13 of the peeling film adjacent to the base material 11 may contact | connect.

  For this reason, as shown in FIG. 4, when the release film 1 is unwound from the winding 30, the static elimination layer 13 can exist in a portion where the winding 30 and the release film 1 are separated (a portion to be peeled off). The generated electricity (especially static electricity) can be suitably eliminated.

  Further, as shown in FIG. 5, in the winding 40 in which the release film 1 on which the green sheet 20 is formed is wound in a roll shape, the central portion of the green sheet 20 is the release layer 12 and the base material 11 of the adjacent release film 1. In contact with. For this reason, most of the green sheet 20 does not come into contact with the charge removal layer 13, and contamination of the green sheet 20 due to contact between the charge removal layer 13 and the green sheet 20 is prevented. Further, when the release film 1 and the green sheet 20 are unwound from the winding 40 as shown in FIG. 6, it is possible to prevent blocking between the green sheet 20 and the winding 40.

  On the other hand, the end of the green sheet 20 on the release film 1 is in contact with the charge removal layer 13. For this reason, as shown in FIG. 6, when the green sheet 20 is peeled from the release film 1, the static elimination layer 13 can be present at a site where the green sheet 20 and the release film 1 are separated (site to be peeled off). Electricity (especially static electricity) generated in the portion can be suitably eliminated.

Hereinafter, each layer which comprises the peeling film 1 which concerns on this embodiment is demonstrated in detail.
<Base material>
The substrate 11 is a belt-like sheet and has a function of imparting physical strength such as rigidity and flexibility to the release film 1.

  The substrate 11 may be composed of any material, but is preferably composed mainly of a resin material. Thereby, the base material 11 has sufficient resistance to tearing and breaking, and can have sufficient flexibility.

  Although it does not specifically limit as a resin material which can be used for the base material 11, For example, polyesters, such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene -Vinyl acetate copolymer, polystyrene, polycarbonate, polymethylpentene, polysulfone, polyether ether ketone, polyether sulfone, polyphenylene sulfide, polyether imide, polyimide, fluororesin, polyamide, acrylic resin, norbornene resin, cycloolefin resin Etc., and one or more of these can be used in combination.

  Among these, it is preferable to use polyester as the resin material, and it is particularly preferable to use polyethylene terephthalate.

  Although the thickness of this base material 11 is not specifically limited, It is preferable that it is 10-150 micrometers, and it is more preferable that it is 20-120 micrometers. Thereby, while making the softness | flexibility of the peeling film 1 moderate, the tolerance with respect to tearing and a fracture | rupture of a peeling film can be made especially excellent.

<Peeling layer>
The release layer 12 is provided on the substrate 11.
The release layer 12 has a function of improving the peelability of the release film 1.

  Further, in the method for producing a green sheet as will be described later, the green sheet is provided on the release layer 12 of the release film 1.

The release layer 12 is mainly composed of a release agent.
The release agent that can be used for the release layer 12 is not particularly limited, but is composed of a silicone release agent composed of a silicone resin; a compound containing a long-chain alkyl group such as polyvinyl carbamate or an alkyl urea derivative. Long-chain alkyl group-containing compound-based release agent; alkyd resin-based release agent composed of alkyd resin such as non-convertible alkyd resin and convertible alkyd resin; high-density polyethylene, low-density polyethylene, linear low-concentration polyethylene Olefin resin-based release agent composed of an olefin resin such as polyethylene, isopropylene homopolymer having an isotactic structure or syndiotactic structure, and crystalline polypropylene resin such as propylene-α-olefin copolymer; Rubber, butadiene rubber, isoprene rubber, styrene-butadiene Rubber-based release agent composed of rubber such as synthetic rubber such as methyl methacrylate-butadiene rubber and acrylonitrile-butadiene rubber; Acrylic resin-based release composed of acrylic resin such as (meth) acrylate copolymer Various release agents such as an agent can be mentioned, and these can be used alone or in combination of two or more.

  Among those described above, when a silicone release agent is used as the release agent constituting the release layer 12, the peelability of the green sheet from the release layer 12 can be made particularly excellent. For this reason, it is possible to reliably prevent blocking when the green sheet is peeled from the release layer 12, and static electricity is hardly generated between the release layer 12 and the green sheet. Further, when a plurality of release films 1 are laminated, adjacent release films 1 can be particularly easily peeled off. For this reason, when the release film 1 is unwound from the winding of the release film 1, blocking is reliably prevented and static electricity is hardly generated.

  The silicone release agent is obtained by curing a silicone release agent composition mainly containing a silicone resin.

  The silicone resin that can be used for the silicone-based release agent composition is not particularly limited as long as it can form the release layer 12. For example, addition reaction type and condensation reaction type silicone resins can be used. Such a silicone resin can undergo a polymerization reaction when energy such as heat and light is applied when the release layer 12 is formed. As a result, the silicone release agent composition is suitably cured to form the release layer 12. Among them, it is preferable to use an addition reaction type silicone resin.

  The addition reaction type silicone resin is not particularly limited as long as it is a silicone resin that can undergo an addition reaction when the silicone release agent composition is cured. For example, polydimethylsiloxane having a vinyl group, polydimethylsiloxane having a hexenyl group. Polyorganosiloxane having an alkenyl group such as siloxane can be used.

  Further, the silicone resin may include a silicone resin that does not contribute to the polymerization reaction in addition to the addition reaction type or condensation reaction type silicone resin as described above. By including such a silicone resin, the release layer 12 is particularly excellent in peelability. In particular, by simultaneously using the silicone resin that contributes to the polymerization reaction and the silicone resin that does not contribute to the polymerization reaction, the silicone resin is prevented from flowing out from the release layer 12, and the surface strength of the release layer 12 is particularly excellent. Meanwhile, the peelability of the release layer 12 can be made particularly excellent.

  Examples of silicone resins that do not contribute to the polymerization reaction include polyorganosiloxanes that do not have alkenyl groups and hydrogen atoms bonded to silicon atoms in the molecule, specifically, trimethylsiloxy group end-capped polydimethylsiloxane, dimethyl Examples thereof include silicone resins such as phenylsiloxy group-end-capped polydimethylsiloxane.

  Moreover, it is preferable that a silicone type release agent composition contains a crosslinking agent. By crosslinking the silicone resin with such a crosslinking agent, the silicone resin is prevented from penetrating from the release layer 12 to the green sheet, and the green sheet is reliably prevented from being contaminated. In addition, the surface strength of the release layer 12 can be made particularly excellent, and the adhesion between the substrate 11 and the release layer 12 becomes particularly excellent.

  Examples of the crosslinking agent include polyorganosiloxane having a Si—H bond in the monomer, specifically, dimethylhydrogensiloxy group end-capped dimethylsiloxane-methylhydrogensiloxane copolymer, trimethylsiloxy group endcapped. Examples thereof include dimethylsiloxane-methylhydrogensiloxane copolymer, trimethylsiloxy group end-capped poly (methylhydrogensiloxane), poly (hydrogensilsesquioxane) and the like, and one or a combination of two or more types may be used. it can.

  The crosslinking agent in the silicone release agent composition is preferably contained in an amount of 0.1 to 100 parts by weight, and more preferably 0.3 to 50 parts by weight with respect to 100 parts by weight of the silicone resin.

  The silicone release agent composition may contain other components in addition to the components as described above. For example, the silicone release agent composition may contain an adhesion improver, a polymerization initiator, a stabilizer, silica, a dye, a pigment, and the like.

  The adhesion improver is a component that improves the adhesion between the release layer 12 and the adjacent layers (base material 11 and charge removal layer 13). Examples of such adhesion improvers include vinyltriacetoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and 3-methacryloxypropyltrimethoxysilane. Is mentioned.

  The stabilizer is a component for preventing the polymerization reaction (curing) of the silicone resin during storage of the silicone release agent composition. Examples of such a stabilizer include 3,5-dimethyl-1-hexen-3-ol, 3-methyl-1-penten-3-ol, 3-methyl-3-penten-1-yne, 3, 5-dimethyl-3-hexen-1-in, tetravinylsiloxane cyclic, benzotriazole and the like can be mentioned.

  Examples of the polymerization initiator include benzoins, benzophenones, acetophenones, α-hydroxy ketones, α-amino ketones, α-diketones, α-diketone dialkyl acetals, anthraquinones, thioxanthones, and the like.

  Although the thickness of this peeling layer 12 is not specifically limited, It is preferable that it is 0.01-3 micrometers, and it is more preferable that it is 0.03-1 micrometer.

<Static elimination layer>
The charge removal layer 13 is a layer having conductivity and a function of removing electricity generated in the release film 1.

  In the present embodiment, the charge removal layer 13 is provided at both ends in the width direction of the release film 1 on the release layer 12. Further, the charge removal layer 13 is provided along the longitudinal direction of the release film 1. In other words, the release film 1 is provided with the charge removal layer 13 so that the release layer 12 is exposed near the center in the width direction. Moreover, on the exposed peeling layer 12, it becomes the green sheet formation area 14 in which the green sheet 20 is formed.

  Thus, by providing the static elimination layer 13 in the edge part of the peeling film 1, the part which the green sheet 20 provided on the peeling film 1 contacts with the static elimination layer 13 becomes a sufficiently small thing. As a result, the conductive component contained in the charge removal layer 13 is prevented from adhering to the green sheet 20.

  Further, the charge removal layer 13 is provided in a region in contact with the green sheet 20 formed on the release layer 12. In this way, the electricity generated in the green sheet 20 can be more reliably removed by the contact between the formed green sheet 20 and the charge removal layer 13.

  The green sheet 20 may be cut off from the green sheet 20 after the green sheet 20 is peeled off from the release film 1. Thereby, the component of the static elimination layer 13 will not adhere more reliably.

  In particular, in the present embodiment, the charge removal layer 13 is provided on the release layer 12. For this reason, the formed green sheet 20 and the charge removal layer 13 are always in contact until the green sheet 20 is peeled from the release film 1. Thereby, the green sheet 20 becomes more difficult to be charged, and dirt such as dust adheres to the green sheet 20 more reliably.

  The ratio of the area of the static elimination layer 13 to the area of the release film 1 in a plan view of the release film 1 is preferably 3 to 30%, and more preferably 5 to 20%. Thereby, while being able to remove the electricity which arises in the peeling film 1 more reliably, the green sheet 20 can be formed in a comparatively wide area | region.

  Moreover, when the peeling film 1 is planarly viewed, the width of the charge removal layer 13 is preferably 3 to 150 mm, and more preferably 10 to 100 mm. Thereby, external static elimination means 50A and 50B which will be described later can more easily come into contact with the static elimination layer 13, and electricity generated in the release film 1 and the green sheet 20 can be more efficiently removed.

  Further, the thickness of the charge removal layer 13 is preferably 0.01 to 3.0 μm, more preferably 0.03 to 1.0 μm, and further preferably 0.05 to 0.30 μm. . Thus, the static elimination performance of the static elimination layer 13 can be made high by setting it as thickness more than predetermined. Moreover, the convex part formed by the static elimination layer 13 can be made not conspicuous by making the thickness of the static elimination layer 13 comparatively thin as mentioned above. For this reason, wrinkles and sagging are prevented from occurring in the winding 30. As a result, when the green sheet 20 is manufactured, there is a problem in the feeding of the release film 1 due to wrinkles and sagging that exist in the winding 30, or the external static elimination means 50A and 50B and the static elimination layer 13 as described later contact each other. It is more reliably prevented that it becomes difficult.

The surface resistivity of the charge removal layer 13 is preferably 10 ¹³ Ω / □ or less, and more preferably 10 ¹⁰ Ω / □ or less.

  Moreover, in this embodiment, the static elimination layer 13 is comprised by curable resin and the electroconductive particle which has the electroconductivity disperse | distributed in curable resin. By using conductive particles in this way, the charge removal layer 13 is reliably imparted with high conductivity. In addition, when such a material is used in a manufacturing method as described later, the static elimination layer 13 can be efficiently formed in a desired shape.

  Although it does not specifically limit as electroconductive particle which can be used for the static elimination layer 13, For example, metal type electroconductive particles, such as metals, such as gold | metal | money, silver, copper, nickel, titanium, and a metal oxide; Carbon nanofibers that are laminated to form fibers, carbon nanofibers such as carbon nanotubes that have a cylindrical shape by winding one sheet of graphite, and carbon-based conductivity such as carbon black, carbon fibers, graphite, and fullerene Particle | grains etc. are mentioned, These can be used 1 type or in combination of 2 or more types.

  Among these, carbon-based conductive particles are preferably used as the conductive particles, more preferably carbon nanofibers, and still more preferably carbon nanotubes. The carbon-based conductive particles can exhibit excellent conductivity even in a relatively small amount. For this reason, when such a carbon type electroconductive particle is used, even if it is a case where the static elimination layer 13 is made comparatively thin, the static elimination layer 13 can have electroconductivity suitably. For this reason, wrinkles and sagging are prevented when the release film 1 is wound.

  In particular, the carbon nanofiber is a fine particle and a particularly highly conductive particle. For this reason, when carbon nanofibers are used as conductive particles, the above-described effects can be obtained more remarkably. In particular, among carbon nanofibers, carbon nanotubes are components that can contribute to improvements in tensile strength, tear strength, and the like. For this reason, when carbon nanotubes are used as the conductive particles, the charge removal layer 13 has less cracks, wear, and the like, and can stably maintain excellent conductivity. Further, the thickness of the charge removal layer 13 can be made sufficiently thin.

  As described above, the carbon nanotube has a cylindrical shape formed by winding a graphite layer. Carbon nanotubes have a huge conjugated double bond system, and conductivity is generated by π electrons in the conjugated double bond system. Further, since the cylindrical fibers are formed only by carbon bonds, the physical strength is excellent.

  As the carbon nanotube, a single-walled carbon nanotube having a structure in which one graphite layer forms a cylinder, and a multilayer having a structure in which two or more graphite layers each form a cylinder and these cylinders are laminated. Although carbon nanotubes can be used, it is preferable to use multi-walled carbon nanotubes. By giving different functions to the outer layer and the inner layer, the multi-walled carbon nanotube can have other functions as well as conductivity. For example, the outer layer of the multi-walled carbon nanotube is surface-treated to have an excellent affinity with the resin material, and the inner layer is made carbon nanotube by maintaining the crystalline arrangement of graphite to have conductivity. Can make the dispersibility in the resin material particularly excellent while making the conductivity particularly excellent.

  In addition, the carbon nanotubes may be open at the ends or closed, but are preferably open. When the end of the carbon nanotube is closed, the end can be opened by treatment with nitric acid or the like.

  Moreover, the terminal shape of the carbon nanotube is not particularly limited, and can be various shapes such as a cylindrical shape and a conical shape.

  Moreover, the average outer diameter of the carbon nanotube is preferably 0.5 to 120 nm, and more preferably 1.0 to 80 nm. As a result, the carbon nanotubes can be uniformly dispersed in the charge removal layer 13, and the conductivity of the carbon nanotubes themselves can be made sufficiently high. Further, when the carbon nanotube having such an average outer shape is used, the static elimination layer 13 becomes sufficiently smooth.

  Moreover, the average length of the carbon nanotubes is preferably 0.5 to 20 μm, and more preferably 0.8 to 15 μm. As a result, the carbon nanotubes can be uniformly dispersed in the charge removal layer 13, and the conductivity of the carbon nanotubes themselves can be made sufficiently high.

  Carbon nanotubes as described above can be produced by catalytic chemical vapor deposition method (CCVD method), vapor phase growth method (CVD method), laser ablation method, carbon rod, It can be manufactured by an arc discharge method using carbon fiber or the like.

  Moreover, it is preferable that the amorphous carbon particle in a carbon nanotube is 20 wt% or less.

  Moreover, it is preferable that it is 0.1-30 wt%, and, as for content of the electroconductive particle in the static elimination layer 13, it is more preferable that it is 0.3-10 wt%. Thereby, the electrical conductivity of the static elimination layer 13 becomes especially excellent. Further, the conductive particles can be suitably dispersed in the static elimination layer 13, and the smoothness and surface strength of the static elimination layer 13 can be made particularly excellent.

Moreover, in this embodiment, the static elimination layer 13 contains curable resin.
The curable resin functions as a binder that disperses the conductive particles as described above in the static elimination layer 13 and maintains the shape of the static elimination layer 13 to impart physical strength to the static elimination layer 13. .

  It does not specifically limit as curable resin which can be used for the static elimination layer 13, For example, a photocurable resin can be used.

  The photocurable resin can be obtained by polymerizing and curing a photocurable resin composition mainly composed of various photoreactive monofunctional monomers, polyfunctional monomers, polyfunctional oligomers, and mixtures thereof. it can.

  The polyfunctional monomer contained in the photocurable resin composition is not particularly limited. For example, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol Di (meth) acrylate, polyethylene glycol di (meth) acrylate, neopentyl glycol adipate di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclo Pentenyl di (meth) acrylate, ethylene oxide modified phosphoric acid di (meth) acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) ) Acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, propionic acid modified dipentaerythritol Polyfunctional acrylates such as penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and caprolactone-modified dipentaerythritol hexa (meth) acrylate may be mentioned. Among these, one or a combination of two or more may be used. it can.

  On the other hand, the polyfunctional oligomer is not particularly limited, and examples thereof include radically polymerizable oligomers such as polyester acrylate, epoxy acrylate, urethane acrylate, and polyol acrylate, and cations such as epoxy, oxetane resin, and vinyl ether resin. A polymerizable oligomer etc. are mentioned, Among these, it can be used 1 type or in combination of 2 or more types.

  Here, as the epoxy resin, for example, a compound obtained by epoxidizing polyphenols such as bisphenol resin or novolac resin with epichlorohydrin, a linear olefin compound or a cyclic olefin compound with a peroxide or the like is obtained. Among these, one or a combination of two or more can be used.

  Examples of the photoreactive monofunctional monomer include cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) acrylate, N-vinylpyrrolidone, and the like. Among these, one or a combination of two or more can be used.

  Moreover, the photocurable resin composition may contain a photopolymerization initiator. Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2 , 2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, α-hydroxycyclohexyl phenylmethanone, 2-methyl-1- [4 -(Methylthio) phenyl] -2-morpholino-propan-1-one, 4- (2-hydroxyethoxy) phenyl-2 (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophene 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylamine benzoate, and the like can be used. Among these, one or a combination of two or more can be used. it can. Examples of photopolymerization initiators for cationic polymerizable monomers and oligomers include oniums such as aromatic sulfonium ions, aromatic oxosulfonium ions and aromatic iodonium ions, tetrafluoroborate, hexafluorophosphate, hexafluoroantimony. Examples thereof include compounds composed of anions, hexafluoroarsenates and the like, and among these, one kind or two or more kinds can be used in combination.

  Moreover, in a photocurable resin composition, it is preferable that a photoinitiator is contained 0.2-10 weight part with respect to the total amount: 100 weight part of various photoreactive monomers and oligomers.

  Further, the charge removal layer 13 may contain a conductive polymer material. When the charge removal layer 13 includes a conductive polymer material, the charge removal layer 13 is particularly excellent in conductivity. Further, even if the conductive particles are not sufficiently dispersed, the static elimination layer 13 has conductivity because such a conductive polymer material exists between these conductive particles. Can do.

  Examples of the conductive polymer material include polyacetylenes such as trans-type polyacetylene, cis-type polyacetylene, and polydiacetylene; poly (phenylene) -type such as poly (p-phenylene) and poly (m-phenylene); polythiophene, poly ( 3-alkylthiophene), poly (3-thiophene-β-ethanesulfonic acid), polythiophene systems such as a mixture of polyalkylenedioxythiophene and polystyrene sulfonate; polyaniline systems such as polyaniline, polymethylaniline, polymethoxyaniline; polypyrrole Polypyrrole systems such as poly (3-methylpyrrole) and poly-3-octylpyrrole; poly (phenylene vinylene) systems such as poly (p-phenylene vinylene); poly (vinylene sulfide) systems; poly (p-phenylene sulfide) systems; Thienirenbi Include such alkylene) compounds can be used singly or in combination of two or more of them.

  Among the above, when the polyacetylene-based, polythiophene-based, polyaniline-based, polypyrrole-based, and poly (phenylene vinylene) -based compounds are used, the charge removal layer 13 has particularly excellent conductivity.

  The content of the conductive polymer material in the charge removal layer 13 is preferably 0.01 to 10% by mass, more preferably 0.01 to 5% by mass, and 0.1 to 3% by mass. % Is more preferable. Thereby, the electrical conductivity of the static elimination layer 13 can be made particularly excellent, and the physical strength of the static elimination layer 13 can be made sufficiently high.

≪Method for producing release film≫
Next, a method for producing the release film as described above will be described.

First, the base material 11 is prepared.
The base material 11 may be subjected to a surface treatment such as an oxidation method, a concavo-convex method, or a primer treatment on each surface. In such a case, for example, the adhesion between the base material 11 and the formed release layer 12 can be improved.

  Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromic acid treatment (wet), flame treatment, hot air treatment, and ozone / ultraviolet irradiation treatment. Examples of the unevenness method include a sand blast method and a solvent treatment method. These surface treatment methods are appropriately selected according to the type of the base film, but generally, the corona discharge treatment method is preferably used from the viewpoints of effects and operability.

Next, the release layer 12 is formed on one surface of the substrate 11.
The release layer 12 can be formed by preparing a release layer coating liquid containing the release agent as described above or a precursor thereof, and applying and curing it on the substrate 11.

  For example, when a silicone release agent is used as the release agent, the release layer coating solution can be obtained by dispersing and dissolving the above-described silicone release agent composition in a solvent or the like.

  Examples of such a solvent include water, toluene, hexane, ethyl acetate, methyl ethyl ketone, heptane and the like, and these can be used alone or in combination of two or more.

  The release layer coating solution is not particularly limited as long as it can be applied onto the substrate 11 and may be in an emulsion state or may not contain a solvent.

  In addition, when the silicone release agent is cured by a reaction such as polymerization, a catalyst may be used. As the catalyst, for example, a platinum group catalyst is used. Examples of the platinum group catalyst include fine platinum, fine platinum adsorbed on a carbon powder carrier, chloroplatinic acid, alcohol-modified chloroplatinic acid, olefin complexes of chloroplatinic acid, palladium, rhodium catalyst, and the like. It is done. It is preferable that the usage-amount of a catalyst is 1-1000 ppm with respect to the total amount of a silicone resin and a crosslinking agent.

  The release layer coating solution thus obtained is applied to one surface of the substrate 11. The peeling layer coating liquid can be applied (coated) to the substrate 11 by, for example, a gravure coating method, a bar coating method, a multi-roll coating method, or the like.

As for the coating liquid for peeling layers provided to the base material 11, it is preferable that the application amount (coating amount) is 0.01-3 g / m < ² > in conversion of solid content, and 0.03-1 g / m. ² is more preferable.

  Curing of the release layer coating solution applied on the substrate 11 can be performed by, for example, heat treatment or light irradiation treatment such as ultraviolet irradiation treatment.

Next, the charge removal layer 13 is formed on the release layer 12.
The charge removal layer 13 is formed by applying a charge removal layer coating liquid containing the above-described conductive particles, curable resin composition, and the like onto the release layer 12 and curing.

  The coating solution for the charge removal layer can be obtained by dissolving or dispersing the above materials in a solvent.

  Examples of the solvent that can be used in the coating solution for the static elimination layer include aliphatic hydrocarbons such as hexane and heptane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and ethylene chloride, methanol, Alcohols such as ethanol, propanol, isopropanol and butanol; ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone and cyclohexanone; esters such as ethyl acetate and butyl acetate; ether solvents such as ethyl cellosolve; ethylene glycol monoethyl ether Examples include glycol ether solvents.

  The neutralizing layer coating solution thus obtained is applied to a necessary portion on the release layer 12. The neutralizing layer coating liquid can be applied (pattern coating) to a necessary portion on the release layer 12 by, for example, a gravure coating method, a die coating method, a multi-roll coating method, or the like.

  When the curable resin is a photocurable resin, the coating liquid for the charge removal layer applied on the release layer 12 is cured by, for example, irradiating light such as ultraviolet rays or visible light, so that the charge removal layer 13 is formed. Is done. Thereby, the peeling film 1 is obtained.

  For example, in the case of ultraviolet rays, the light beam applied to the neutralizing layer coating solution can be irradiated using a high-pressure mercury lamp, a fusion H lamp, a xenon lamp, or the like.

  Further, when the curable resin of the charge removal layer is a thermosetting resin, the charge removal layer coating liquid may be cured by heat treatment to form the charge removal layer 13.

≪Green sheet manufacturing method≫
Next, the manufacturing method of a green sheet is demonstrated.

  The manufacturing method of the green sheet of this embodiment manufactures the green sheet 20 using the peeling film 1 as mentioned above.

  The green sheet manufacturing method of the present embodiment includes a green sheet material applying step of forming a green sheet precursor by applying a green sheet material containing ceramic particles and a binder on the release film 1, and a green sheet precursor. A solidifying step for solidifying.

<Green sheet material application process>
In this step, a green sheet material containing ceramic particles and a binder is applied on the release film 1 to form a green sheet precursor.

  The green sheet material is applied to the release film 1 in a slurry (green slurry) in which ceramic particles and a binder are dispersed and dissolved by a solvent.

The ceramic particles that can be used for the green sheet material are not particularly limited, and known ceramic particles used for the production of green sheets can be used, and examples thereof include barium titanate (BaTiO ₃ ).

  Moreover, it does not specifically limit as a binder which can be used for green sheet material, The well-known binder used for manufacture of a green sheet can be used, For example, an acrylic resin, polyvinyl butyral, polyvinyl alcohol, ethyl cellulose etc. are mentioned. It is done.

  Moreover, it does not specifically limit as a solvent which can be used for a green slurry, For example, methanol, ethanol, toluene, ethyl acetate, xylene, methyl ethyl ketone, methyl butyl ketone etc. are mentioned, It combines 1 type (s) or 2 or more types. Can be used.

The green slurry as described above is applied onto the release film 1.
The green slurry can be applied onto the release film 1 by unwinding the release film 1 from the winding of the release film 1 and coating the green slurry on the unfolded release film 1.

The green slurry can be applied by an existing coating method such as a doctor blade method, a lip coating method, a roll coating method, or a die coating method.
In this step, when the green slurry is applied to the release film 1, the release film 1 is neutralized.

  As shown in FIG. 4, the charge removal of the release film 1 is performed by bringing an external charge removal means 50 </ b> A into contact with the charge removal layer 13 of the released release film 1. The neutralization unit 50A may be any one that is conductive and grounded. In the present embodiment, the neutralization unit 50A is a grounded roller.

  For this reason, by performing static elimination in this way, the static elimination layer 13 can suitably remove the generated static electricity, and the fed release film 1 is prevented from being charged. As a result, the release film 1 can be stably fed out from the winding. Further, by preventing the release layer 12 from being charged, dust is prevented from adhering to the release layer 12. For this reason, it is suitably prevented that pinholes, cracks, and coating unevenness occur in the coated green slurry.

  The green slurry is preferably applied so as to be in contact with the charge removal layer 13. That is, the green sheet precursor is preferably formed so as to be in contact with the charge removal layer 13. Thereby, in the process mentioned later, the formed green sheet 20 and the static elimination layer 13 become closely_contact | adhered. Therefore, even when the formed green sheet 20 is peeled off from the release film 1, the green sheet 20 is peeled off while being neutralized. For this reason, it can prevent more reliably that dust adheres to the green sheet 20 manufactured.

<Solidification process>
Next, the green sheet material applied on the release film 1 is solidified.
Thereby, the green sheet 20 is obtained.

  The green sheet material can be solidified by removing the solvent from the green slurry.

  The removal of the solvent from the green slurry can be performed, for example, by heating or drying under reduced pressure.

  The green sheet 20 thus obtained is usually used by printing a paste-like internal electrode on its surface, peeling it from the release film 1, and cutting it into a predetermined shape and size.

  When the green sheet 20 is peeled from the release film 1, as shown in FIG. 6, after the release film 1 is unwound from the winding 40 of the release film 1 on which the green sheet 20 is carried, the green sheet 20 is peeled off. 1 is peeled off. At this time, it is preferable that at least a part of the static elimination layer 13 and the external static elimination means 50B come into contact with each other. Thereby, electricity generated at the time of peeling can be suitably removed, and the green sheet 20 becomes difficult to be attached with dust or the like.

  Further, the green sheet 20 is particularly preferably prevented from being contaminated by the charge removal layer 13 of the release film 1 by cutting the end in the width direction.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. However, differences from the above-described embodiment will be mainly described, and description of similar matters will be omitted.

  FIG. 7 is a cross-sectional view of the release film according to the second embodiment of the present invention, FIG. 8 is a cross-sectional view showing a part of the winding of the release film shown in FIG. These are the cross-sectional views which show a part of winding of the state which wound the peeling film shown in FIG. 7 in which the green sheet was formed in roll shape.

  1 A of peeling films have the base material 11, the peeling layer 12 provided in the one surface of the base material 11, and the static elimination layer 13a provided in the surface on the opposite side to the peeling layer 12 of the base material 11. ing. The green sheet 20 is provided in the green sheet forming region 14 on the release layer 12.

  In the present embodiment, the charge removal layer 13 a is provided on the surface opposite to the green sheet forming region 14. For this reason, at the time of manufacturing a green sheet, when the green slurry is applied to the green sheet forming region 14 to form the green sheet precursor, the green sheet precursor and the charge removal layer 13a do not come into contact with each other. For this reason, it is reliably prevented that the components of the charge removal layer 13a are eluted into the green sheet precursor, and the formed green sheet 20 is more reliably prevented from being contaminated by the charge removal layer 13a.

  Further, as shown in FIG. 8, in the winding 30A in which the release film 1A is wound in a roll shape, each release film 1A is in contact with the charge removal layer 13a of the adjacent release film 1A. For this reason, when the release film 1A is unwound from the winding 30A, the static elimination layer 13a can be present in the peeling portion between the winding 30A and the release film 1A, and electricity generated at the time of peeling can be suitably removed. it can.

  Moreover, as shown in FIG. 9, in the winding 40A obtained by winding the release film 1A on which the green sheet 20 is formed in a roll shape, each green sheet 20 is in contact with the charge removal layer 13a of the adjacent release film 1A. For this reason, when the release film 1A is unwound from the winding 40A, the static elimination layer 13a can be present at the peeling portion between the winding 30A and the green sheet 20, and electricity generated at the time of peeling can be suitably removed. it can.

  As mentioned above, although this invention was demonstrated about embodiment of illustration, this invention is not limited to this.

  For example, as shown in FIG. 10, the release film 1 </ b> B may be one in which the charge removal layer 13 b is embedded in the release layer 12 a. In such a case, the release film 1B has particularly few unevenness in the width direction, and the sheet feeding and unwinding of the release film 1B are particularly easy.

  Further, for example, as shown in FIG. 11, the release film 1 </ b> C is peeled off on the surface of the base 11 opposite to the release layer 12 in addition to the release layer 12 provided on the surface on which the green sheet 20 is formed. The layer 12b may be provided. In such a case, peeling between the green sheet 20 and the release film 1C is particularly easy, and generation of static electricity at the time of peeling is particularly suppressed. In particular, when the release layer 12 and the release layer 12b are made of the same material, static electricity is hardly generated when the laminated release films 1C are released.

  For example, as shown in FIG. 12, the release film 1 </ b> D may be provided so that the charge removal layer 13 c is intermittently in contact with the green sheet 20 along the longitudinal direction of the release film 1. Thereby, the peeling film 1 and the green sheet 20 can be prevented from being charged while making the contact of the green sheet 20 with the charge removal layer 13c particularly small. Further, the formed green sheet 20 can be efficiently used for manufacturing an electronic circuit board over a wider area.

  Moreover, although the static elimination layer demonstrated as what was provided in the both ends of the width direction of one surface of a peeling film in embodiment mentioned above, it is not limited to this. For example, the charge removal layer may be provided only at one end in the width direction. For example, the charge removal layer may be provided on both surfaces of the release film.

  In the above-described embodiment, the static elimination layer has been described as being composed of conductive particles and a curable resin, but is not limited thereto. For example, the charge removal layer may be configured by a thin film of a conductive material such as metal.

Moreover, the intermediate | middle layer may be provided between each layer of a peeling film.
Further, the charge removal layer may be bonded to the green sheet and have a function of fixing the green sheet. Thereby, it is possible to effectively prevent the green sheet from being lifted or peeled off during conveyance.

  Further, in the above-described embodiment, the roller is used as the charge eliminating unit, but the present invention is not limited to this. There is no particular limitation as long as it can contact the charge removal layer and is grounded. For example, an installed blade or the like can be used. Further, the winding shaft may function as a static elimination means.

Next, specific examples of the present invention will be described.
1. Production of release film (Example 1)
First, a release layer coating solution was prepared.

The release layer coating solution is addition-reactive silicone, manufactured by Shin-Etsu Chemical Co., Ltd., trade name “KS-847H”): 100 parts by mass, platinum catalyst, manufactured by Shin-Etsu Chemical Co., Ltd., trade name “CAT-PL-50T”): It was prepared by dissolving 1 part by weight in toluene as a solvent so that the solid content was 1.1% by mass.
Next, this release layer coating solution was used as a base material for a polyethylene terephthalate (PET) film (thickness: 38 μm, width: 200 mm, manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., trade name “T-100”). The surface was uniformly coated by gravure coating so that the thickness after drying was 0.1 μm, and dried for 1 minute with a dryer at 130 ° C. to form a release layer.

Next, a coating solution for the charge removal layer was prepared.
Acrylic monomer containing dipentaerythritol hexaacrylate, pentaerythritol hexaacrylate, and N-vinylpyrrolidone as a photocurable resin in a weight ratio of 45:20:10: 75 parts by mass, and butyl acetate as a solvent: 20 A curable resin solution containing 30 parts by mass of isopropanol was prepared.

  In addition, a conductive polymer aqueous solution containing 1.3% by mass of polyethylene dioxythiophene / polystyrene sulfonate (PEDT / PSS) as a conductive polymer material was prepared.

  Curable resin solution as described above: 125 parts by mass, conductive polymer aqueous solution: 15.5 parts by mass, and α-hydroxycyclohexylphenylmethanone as a photoinitiator: 0.2 parts by mass are mixed. The mixture was diluted with isopropanol so that the total amount of the acrylic monomer and the conductive polymer material was 1% by mass to obtain a mixed solution.

  To this mixed solution, a 3.0 mass% isopropanol dispersion of carbon nanotubes (average diameter: 15 nm, average length: 1 μm, tubular, manufactured by Gemco, trade name “CNF-T”) Layer) was added so that the content in the layer was 1.0% by mass, to prepare a coating solution for the charge removal layer.

Next, apply this neutralizing layer coating solution uniformly by gravure coating method so that the thickness after drying is 0.05 μm at both ends in the width direction on the release layer of the PET film: 10 mm did. Next, the coating is heated for 1 minute in a dryer at 55 ° C., and immediately irradiated with UV light at a conveyor speed: 10 m / min with a fusion H bulb: 240 W / cm, and a conveyor type UV irradiator attached to one lamp. The neutralization layer coating solution thus formed was cured to form a neutralization layer.
Thereby, a release film was obtained.

(Examples 2 to 4)
A release film was produced in the same manner as in Example 1 except that the type, content, thickness, and width of the charge removal layer contained in the charge removal layer were changed as shown in Table 1.

(Example 5)
In the preparation of the coating solution for the charge removal layer, the carbon nanotubes were used so that the content in the total solid content (charge removal layer) was 5.0 mass% without using the conductive polymer aqueous solution. A release film was produced in the same manner as in Example 1.

(Example 6)
Mixture of stearyl-modified alkyd resin and methylated melamine (manufactured by Hitachi Chemical Co., Ltd., trade name “Tesfine 303”): 100 parts by weight and p-toluenesulfonic acid: 3 parts by weight are dissolved in toluene, and the solid content concentration is A 2 wt% release layer coating solution was prepared.

  A release film was produced in the same manner as in Example 1 except that this release layer coating solution was used for forming the release layer, and the drying conditions for forming the release layer were 140 ° C. for 1 minute.

(Example 7)
Example 1 except that the charge-removing layer was not provided on the release layer, and both sides in the width direction: 10 mm were provided on the opposite side of the PET film from which the release layer was provided. A release film was produced in the same manner.

(Examples 8 and 9)
A release film was produced in the same manner as in Example 7 except that the type and content of the material contained in the charge removal layer, the thickness and width of the charge removal layer were changed as shown in Table 1.

(Comparative Example 1)
A release film was produced in the same manner as in Example 1 except that the charge removal layer was not formed.

(Comparative Example 2)
A release film was produced in the same manner as in Example 1 except that the charge removal layer was not provided on the release layer, but was provided on the entire surface of the substrate opposite to the release layer.

  In Table 1, about the peeling film of each Example and each comparative example, the structure of a peeling layer and a static elimination layer is shown. In the table, “CNT” is a carbon nanotube, “CNP” is a carbon nanofiber formed by laminating plate-like carbon (trade name “CNF-P” manufactured by Gemco), and “PEDT” is , Polyethylene dioxythiophene, and “PSS” represent polystyrene sulfonate, respectively.

2. 2. Evaluation of release film 2.1 Charge amount during unwinding The release film obtained in each Example and each Comparative Example was wound in a roll shape and stored for 30 days under conditions of 23 ° C. and 50% RH. The amount of charge on the release layer when it was fed out at 100 m / min was measured using a static electricity meter (SIMX: FMX-002) and evaluated according to the following evaluation criteria. Further, at the time of unwinding, static elimination was performed by bringing a grounded roller (static elimination means) into contact with the static elimination layer of the release film.

A: Charge amount is less than 5.0 kV.
○: Charge amount is 5.0 kV or more and less than 8.0 kV.
Δ: Charge amount is 8.0 kV or more and less than 10.0 kV.
X: Charge amount is 10.0 kV or more.

2.2 Evaluation of blocking resistance In the state where the release film obtained in each Example and each Comparative Example was wound up in a roll shape, the film was stored for 30 days at 40 ° C., and then visually checked for roll appearance and unwinded. The state was confirmed and evaluated according to the following evaluation criteria.

(Double-circle): Generation | occurrence | production of blocking is not seen at all.
○: Slight blocking is observed, but there is no practical problem.
X: Blocking is noticeable and the release film cannot be normally peeled off.

3. Production of ceramic green sheet Barium titanate (BaTiO ₃ ) powder: 100 parts by weight, polyvinyl butyral: 8 parts by weight, dioctyl phthalate: 4 parts by weight, mixed liquid of toluene and ethanol (weight ratio 1: 1): 80 Part by weight was added and mixed and dispersed in a ball mill to prepare a green slurry.

  The slurry is uniformly applied by a doctor blade method on the release film obtained in each of the above Examples and Comparative Examples so that the thickness after drying becomes 5 μm, thereby forming a green sheet precursor (coating film). did. (Green sheet material application process). At this time, the release film fed out from the roll was subjected to static elimination by bringing a grounded roller (static elimination means) into contact with the static elimination layer of the release film immediately before the slurry was applied on the release film.

  The green sheet precursor formed on the release film was dried to produce a green sheet (ceramic green sheet) on the release film (solidification step).

4). Evaluation of Release Film Carrying Green Sheet 4.1 Charge Amount at Feeding out The release film of each example and each comparative example carrying a green sheet was rolled up in a roll shape at 23 ° C. and 50% RH. After storing for 30 days under the conditions, the amount of charge on the green sheet when fed out at 100 m / min with a slitter was measured using a static electricity meter (SIMX: FMX-002) and evaluated according to the following evaluation criteria. did. Further, at the time of feeding, the release film was neutralized by bringing a grounded roller (static elimination means) into contact with the neutralization layer of the release film.

A: Charge amount is less than 8.0 kV.
○: Charge amount is 8.0 kV or more and less than 10.0 kV.
Δ: Charge amount is 10.0 kV or more and less than 15.0 kV.
X: Charge amount is 15.0 kV or more.

4.2 Charge amount at the time of green sheet peeling About the release film carrying the green sheet of each example and each comparative example that was fed out in 2.1, an adhesive tape (manufactured by Nitto Denko Corporation, The product surface “31B tape”) was bonded. This green sheet with an adhesive tape was conditioned at 23 ° C. and 50% humidity for 24 hours, and then cut to 60 mm × 70 mm to prepare a sample for measuring the peel charge amount. Using a tensile tester, the release film was pulled in the direction of 180 ° at a speed of 100 m / min, and the amount of charge on the green sheet surface at this time was measured using a static electricity measuring device (manufactured by SIMCO: FMX-002). did. The peel charge amount on the release film surface was peeled off the green sheet side under the same conditions as described above, the charge amount on the release film surface was measured, and evaluated according to the following evaluation criteria. Further, at the time of peeling, the release film was neutralized by bringing a grounded roller (static elimination means) into contact with the neutralization layer of the release film immediately after green sheet peeling.

A: Charge amount is less than 8.0 kV.
○: Charge amount is 8.0 kV or more and less than 10.0 kV.
Δ: Charge amount is 10.0 kV or more and less than 15.0 kV.
X: Charge amount is 15.0 kV or more.

4.3 Evaluation of blocking resistance About each of the release sheets of each Example and each Comparative Example on which a green sheet was supported, two test pieces were prepared by cutting the sheet in a width direction of 25 mm. Two test pieces were overlapped so that the green sheet surface of one test piece and the release film of the other test piece were in contact with each other. Next, a load of 1 kg / cm ² was applied to the ^two test pieces that were overlapped, and the test piece was left in an environment of 40 ° C. for 24 hours.

  Thereafter, one of the two test pieces was peeled off, visually confirmed, and evaluated according to the following evaluation criteria.

(Double-circle): Generation | occurrence | production of blocking is not seen at all.
○: Slight blocking is observed, but there is no practical problem.
X: Blocking is noticeable and the green sheet cannot be normally peeled off.

  As is apparent from Table 2, the release film of the present invention was prevented from being charged and blocked during feeding, and was easy to feed. In addition, the release film of the present invention was not easily charged when the green sheet was peeled off. On the other hand, satisfactory results were not obtained in the comparative example.

It is a cross-sectional view of the peeling film which concerns on 1st Embodiment of this invention. FIG. 2 is a plan view of the release film shown in FIG. FIG. 3 is a cross-sectional view showing a part of the winding in a state where the release film shown in FIG. 1 is rolled. FIG. 4 is a longitudinal sectional view when the release film is drawn out from the winding of FIG. It is a cross-sectional view which shows a part of winding of the state which wound the peeling film shown in FIG. 1 in which the green sheet was formed in roll shape. It is a longitudinal cross-sectional view when paying out a peeling film from the winding of FIG. It is a cross-sectional view of a release film according to a second embodiment of the present invention. It is a cross-sectional view which shows a part of winding of the state which wound the peeling film shown in FIG. 7 in roll shape. It is a cross-sectional view which shows a part of winding of the state which wound the peeling film shown in FIG. 7 in which the green sheet was formed in roll shape. It is a cross-sectional view which shows other embodiment of the peeling film of this invention. It is a cross-sectional view which shows other embodiment of the peeling film of this invention. It is a top view which shows other embodiment of the peeling film of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1A, 1B, 1C, 1D ... Release film 11 ... Base material 12, 12a, 12b ... Release layer 13, 13a, 13b, 13c ... Static elimination layer 14 ... Green sheet formation area 20 ... Green sheets 30, 30A, 40, 40A ... Winding 50A, 50B ... Static elimination means

Claims (13)

A strip-shaped substrate;
A release film provided on the substrate and having a release layer mainly composed of a release agent,
A release film comprising a charge removal layer for removing electricity from the release film provided along the longitudinal direction of the release film in the vicinity of at least one end in the width direction of the release film.   The release film according to claim 1, wherein the release film is one that is neutralized by contact between the charge removal layer and an external charge removal means.   The release film according to claim 1 or 2, wherein the charge removal layer is provided on the same side of the substrate as the release layer.   The release film according to any one of claims 1 to 3, wherein a ratio of the area of the charge removal layer to the area of the release film in a plan view of the release film is 3 to 30%.   The release film according to claim 1, wherein the charge removal layer contains conductive particles.   The release film according to claim 5, wherein the conductive particles are carbon nanofibers.   The release film according to claim 1, wherein the charge removal layer includes a conductive polymer material.   The release film according to any one of claims 1 to 7, wherein the release film is used by being bonded to a green sheet.   The release film according to claim 8, wherein the charge removal layer is provided in a region in contact with the green sheet formed on the release layer. A green sheet material application step of applying a green sheet material containing ceramic particles and a binder on the release film to form a green sheet precursor;
Solidifying step of solidifying the green sheet precursor,
The release film is a strip-shaped substrate, a release layer provided on the substrate and mainly composed of a release agent, and the longitudinal direction of the release film near at least one end in the width direction of the release film. A method for producing a green sheet, comprising: a neutralization layer that neutralizes the release film provided along the surface.   The manufacturing method of the green sheet of Claim 10 which neutralizes the said peeling film by the said static elimination layer and external static elimination means contacting.   The method for producing a green sheet according to claim 10 or 11, wherein in the green sheet material application step, the release film is neutralized when the green sheet material is applied to the release film.   The method for producing a green sheet according to any one of claims 10 to 12, wherein in the green sheet applying step, the green sheet precursor is formed in contact with the charge removal layer.

Images