JP2022079524A - Release film for ceramic green sheet production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a release film for ceramic green sheet production that is capable of molding a ceramic green sheet having reduced defects even in an ultrathin layer product with a thickness of 1 μm or lower by providing a release layer having low and uniform release strength and having excellent solvent resistance, while maintaining the high flatness of the release layer surface in the release film.

SOLUTION: A release film for ceramic green sheet production has a release layer placed on at least one side of a polyester film directly or through another layer. The release layer comprises a cured composition containing a binder component (a) and a silsesquioxane component (b). The binder component (a) is a radical curable substance. The silsesquioxane component (b) has, in each molecule, at least one reactive functional group selected from an acryloyl group, a methacryloyl group, an alkenyl group and a thiol group.

SELECTED DRAWING: None

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a release film for manufacturing a ceramic green sheet, and more specifically, suppresses the occurrence of green sheet defects such as pinholes and uneven thickness and process defects such as peeling defects during the production of ultrathin ceramic green sheets. It relates to a release film for manufacturing a possible ceramic green sheet.

Conventionally, a release film having a polyester film as a base material and a release layer laminated on the polyester film has been used for molding ceramic green sheets such as laminated ceramic capacitors and ceramic substrates. In recent years, as the size and capacity of multilayer ceramic capacitors have increased, the thickness of ceramic green sheets has also tended to decrease. The ceramic green sheet is molded by applying a slurry containing a ceramic component such as barium titanate and a binder resin such as polyvinyl acetal resin onto a release film and drying it. A laminated ceramic capacitor is manufactured by printing an electrode on a molded ceramic green sheet, peeling it from a release film, laminating and pressing the ceramic green sheet, firing, and applying an external electrode. Until now, when a ceramic green sheet is molded on the surface of the release layer of a polyester film, minute protrusions on the surface of the release layer affect the molded ceramic green sheet, and defects such as cissing and pinholes are likely to occur. There was a problem such as. Therefore, a method for realizing a release layer surface having excellent flatness has been developed (see, for example, Patent Document 1).

However, in recent years, further thinning of the ceramic green sheet has progressed, and a ceramic green sheet having a thickness of 1.0 μm or less, more specifically 0.2 μm to 1.0 μm, has been required. Therefore, a release film having a smoother release layer surface is desired. In addition, since the strength of the ceramic green sheet decreases as the film becomes thinner, it is also desired that the peeling force when the ceramic green sheet is peeled from the release film is low and uniform. That is, it is becoming more important to minimize the force applied to the ceramic green sheet when peeling the ceramic green sheet from the release film so as not to damage the ceramic green sheet.

In recent years, by using a composition containing a radical curable substance as a main component, which reacts under irradiation with active energy rays, as a release layer cured by ultraviolet rays, the surface of the release layer is excellent in smoothness and peelability. Was found (see, for example, Patent Documents 2 and 3). More specifically, by curing the radical curable substance with ultraviolet rays, the elastic modulus of the release layer is increased, and the release layer is less likely to be deformed when peeled off (it is difficult for the release layer to follow the ceramic green sheet). It can be a release layer having excellent peelability. At the same time, the release agent (additive added to impart releasability) contained in the composition segregates on the surface of the release layer during drying, so that it has excellent smoothness and further exfoliation. It can be an excellent release layer.

However, according to the descriptions of Patent Documents 2 and 3, a silicone component typified by polydimethylsiloxane is used as a mold release agent. Therefore, the elastic modulus of the release layer surface, which is considered to have segregated silicone components, decreases due to the flexibility derived from the silicone skeleton, which may cause peeling failure when peeling the ultrathin ceramic green sheet. was there. In addition, the solvent resistance of the silicone component may be a problem. More specifically, since the surface of the release layer is eroded by the organic solvent used during the molding of the ceramic green sheet and the printing of the internal electrodes, there is a possibility that the smoothness and peelability of the ceramic green sheet may be problematic. Further, the silicone component is transferred to the ceramic green sheet, which may cause process defects such as poor adhesion and deterioration of reliability due to contamination with the product.

Japanese Unexamined Patent Publication No. 2000-117899 International Publication No. 2013/145864 International Publication No. 2013/145865

The present invention has been made in the background of the problems of the prior art. That is, an object of the present invention is to provide a release layer having a low peeling force, a uniform release force, and excellent solvent resistance while maintaining high smoothness on the surface of the release layer of the release film, thereby increasing the thickness. It is an object of the present invention to provide a release film for manufacturing a ceramic green sheet capable of molding a ceramic green sheet having few defects even in an ultrathin layer product of 1 μm or less.

That is, the present invention has the following configuration.
1. 1. A release film in which a release layer is provided on at least one surface of a polyester film directly or via another layer, wherein the release layer contains a binder component (a) and a ceramic oxane component (b). A mold release film for manufacturing ceramic green sheets, which is made by curing an object.
2. 2. The release film for producing a ceramic green sheet according to the first aspect, wherein the content of the silsesquioxane component (b) with respect to the total solid content of the composition is 0.01% by mass to 60% by mass.
3. 3. The release film for producing a ceramic green sheet according to the first or second above, wherein the silsesquioxane component (b) has a polyorganosiloxane group in the molecule.
4. The release film for producing a ceramic green sheet according to any one of the above 1 to 3, wherein the region surface average roughness (Sa) of the surface of the release layer is 7 nm or less.
5. The binder component (a) is a radical curable substance, and the silsesquioxane component (b) has at least one reactive functional group selected from an acryloyl group, a methacryloyl group, an alkenyl group and a thiol group in the molecule. The release film for producing a ceramic green sheet according to any one of the above 1st to 4th having.
6. The binder component (a) is a cationically curable substance, and the silsesquioxane component (b) has at least one reactive functional group selected from an epoxy group, an alicyclic epoxy group and an oxetanyl group in the molecule. The release film for producing a ceramic green sheet according to any one of the above 1st to 4th having.
7. The binder component (a) is a melamine-based substance, and the silsesquioxane component (b) has at least one reactive functional group selected from a hydroxyl group, a carboxyl group, an amino group and a hydrosilyl group in the molecule. The release film for producing a ceramic green sheet according to any one of the first to fourth.
8. The polyester film has a surface layer A that does not substantially contain inorganic particles and a surface layer B on the opposite side that contains inorganic particles, and a release layer is provided on the surface layer A. The ceramic green sheet according to any one of 1 to 7 above, wherein the inorganic particles contained in B are silica particles and / or calcium carbonate particles, and the total amount of the inorganic particles is contained in the surface layer B at 5000 to 15000 ppm. Release film for manufacturing.
9. A method for producing a ceramic green sheet having a thickness of 0.2 μm to 1.0 μm, wherein the ceramic green sheet is produced by using the release film for producing the ceramic green sheet according to any one of the above 1 to 8. .. A method for manufacturing a ceramic capacitor, which employs the method for manufacturing a ceramic green sheet according to the ninth item.

The release film for manufacturing a ceramic green sheet of the present invention has higher hardness and solvent resistance on the surface of the release layer than the release layer of the conventional release film, so that it has excellent peelability and transfer of Si-containing components. Can be suppressed. Therefore, it is possible to provide a release film for manufacturing a ceramic green sheet in which there is no risk of defects in the ceramic green sheet and process defects such as peeling defects and adhesive defects even during the production of an ultrathin layer ceramic green sheet.

In the present invention, a release layer is provided on at least one surface of a polyester film directly or via another layer, and a composition in which the release layer contains a binder component (a) and a silsesquioxane component (b) is cured. It is preferable that the film is made of. Hereinafter, the present invention will be described in detail.

(Polyester film)
The polyester constituting the polyester film used as the base material of the present invention is not particularly limited, and a film-molded polyester usually generally used as a base material for a release film can be used, but it is preferable. It is preferable to use a crystalline linear saturated polyester composed of an aromatic dibasic acid component and a diol component, for example, polyethylene terephthalate, polyethylene-2,6-naphthalate, polybutylene terephthalate, polytrimethylene terephthalate or resins thereof. A copolymer containing a constituent component as a main component is more preferable, and a polyester film formed from polyethylene terephthalate is particularly preferable. The repeating unit of ethylene terephthalate is preferably 90 mol% or more, more preferably 95 mol% or more, and other dicarboxylic acid components and diol components may be copolymerized in a small amount, but from the viewpoint of cost. , Preferably made only from terephthalic acid and ethylene glycol. Further, known additives such as antioxidants, light stabilizers, ultraviolet absorbers, crystallization agents and the like may be added as long as the effects of the film of the present invention are not impaired. The polyester film is preferably a biaxially oriented polyester film because of its high bidirectional elastic modulus and the like.

The intrinsic viscosity of the polyethylene terephthalate film is preferably 0.50 to 0.70 dl / g, more preferably 0.52 to 0.62 dl / g. When the intrinsic viscosity is 0.50 dl / g or more, it is preferable because many breaks do not occur in the stretching step. On the contrary, when it is 0.70 dl / g or less, it is preferable because the cutability when cutting to a predetermined product width is good and dimensional defects do not occur. Further, it is preferable that the raw material is sufficiently vacuum dried.

The method for producing a polyester film in the present invention is not particularly limited, and a method generally used in the past can be used. For example, the polyester can be obtained by melting the polyester with an extruder, extruding it into a film, cooling it with a rotary cooling drum to obtain an unstretched film, and biaxially stretching the unstretched film. The biaxially stretched film can be obtained by a method of sequentially biaxially stretching a uniaxially stretched film in a vertical or horizontal direction in a horizontal or vertical direction, or a method of simultaneously biaxially stretching an unstretched film in the vertical and horizontal directions. I can.

In the present invention, the stretching temperature at the time of stretching the polyester film is preferably set to be equal to or higher than the secondary transition point (Tg) of the polyester. It is preferable to stretch 1 to 8 times, particularly 2 to 6 times in each of the vertical and horizontal directions.

The thickness of the polyester film is preferably 12 to 50 μm, more preferably 15 to 38 μm, and even more preferably 19 to 33 μm. When the thickness of the film is 12 μm or more, it is preferable because there is no possibility of deformation due to heat during film production, processing process, and molding. On the other hand, when the thickness of the film is 50 μm or less, the amount of the film discarded after use does not become extremely large, which is preferable in reducing the environmental load.

The polyester film base material may be a single layer or a multilayer of two or more layers, but is preferably a laminated film having a surface layer A substantially free of inorganic particles on at least one surface. .. In the case of a laminated polyester film having a multilayer structure of two or more layers, it is preferable to have a surface layer B capable of containing inorganic particles or the like on the opposite surface of the surface layer A which does not substantially contain inorganic particles. As for the laminated structure, if the layer on the side to which the release layer is applied is the A layer, the layer on the opposite surface thereof is the B layer, and the core layer other than these is the C layer, the layer structure in the thickness direction is the release layer / A /. B, or a laminated structure such as a release layer / A / C / B can be mentioned. As a matter of course, the C layer may have a plurality of layer configurations. Further, the surface layer B may not contain inorganic particles. In that case, it is preferable to provide a coat layer containing at least inorganic particles and a binder on the surface layer B in order to impart slipperiness for winding the film into a roll.

In the polyester film base material of the present invention, it is preferable that the surface layer A forming the surface to which the release layer is applied does not substantially contain inorganic particles. At this time, the region surface average roughness (Sa) of the surface layer A is preferably 7 nm or less. When Sa is 7 nm or less, pinholes and the like are less likely to occur during molding of the ultrathin layer ceramic green sheet to be laminated, which is preferable. It can be said that the smaller the region surface average roughness (Sa) of the surface layer A is, the more preferable it is, but it may be 0.1 nm or more. Here, when an anchor coat layer or the like described later is provided on the surface layer A, it is preferable that the coat layer does not substantially contain inorganic particles, and the region surface average roughness (Sa) after laminating the coat layer is in the above range. It is preferable to enter. In the present invention, "substantially free of inorganic particles" means that the inorganic particles are 50 ppm or less, preferably 10 ppm or less, and most preferably the detection limit or less when the inorganic elements are quantified by the optical X-ray analysis. It means the content. This means that even if inorganic particles are not actively added to the film, contamination components derived from foreign substances and stains attached to raw material resins or lines and devices in the film manufacturing process are peeled off and mixed into the film. This is because there are cases.

In the polyester film base material of the present invention, the surface layer B forming the opposite surface to the surface to which the release layer is applied preferably contains inorganic particles from the viewpoint of the slipperiness of the film and the ease with which air can escape. In particular, it is preferable to use silica particles and / or calcium carbonate particles. The content of the inorganic particles contained is preferably 5000 to 15000 ppm in total of the inorganic particles in the surface layer B. At this time, the region surface average roughness (Sa) of the film of the surface layer B is preferably in the range of 1 to 40 nm. More preferably, it is in the range of 5 to 35 nm. When the total amount of silica particles and / or calcium carbonate particles is 5000 ppm or more and Sa is 1 nm or more, air can be uniformly released when the film is wound into a roll shape, and the winding shape is good and the flatness is good. , Suitable for the production of ultra-thin layer ceramic green sheet. Further, when the total amount of silica particles and / or calcium carbonate particles is 15,000 ppm or less and Sa is 40 nm or less, the lubricant is less likely to aggregate and coarse protrusions cannot be formed, so that the quality is stable during the production of an ultrathin ceramic green sheet. It is preferable.

As the particles contained in the B layer, inactive inorganic particles and / or heat-resistant organic particles other than silica and / or calcium carbonate can also be used, but from the viewpoint of transparency and cost, silica particles and / or It is more preferable to use calcium carbonate particles. Further, examples of the inorganic particles that can be used include alumina-silica composite oxide particles and hydroxyapatite particles. Examples of the heat-resistant organic particles include crosslinked polyacrylic particles, crosslinked polystyrene particles, and benzoguanamine particles. When silica particles are used, porous colloidal silica is preferable, and when calcium carbonate particles are used, light calcium carbonate surface-treated with a polyacrylic acid-based polymer compound is preferable from the viewpoint of preventing the lubricant from falling off. ..

The average particle size of the inorganic particles added to the surface layer B is preferably 0.1 μm or more and 2.0 μm or less, and particularly preferably 0.5 μm or more and 1.0 μm or less. When the average particle size of the inorganic particles is 0.1 μm or more, the slipperiness of the release film is good, which is preferable. Further, when the average particle diameter is 2.0 μm or less, there is no possibility that pinholes are generated in the ceramic green sheet due to the coarse particles on the surface of the release layer, which is preferable.

The surface layer B may contain two or more types of particles having different materials. Further, particles of the same type having different average particle sizes may be contained.

When the surface layer B does not contain particles, it is preferable to provide slipperiness with a coat layer containing particles on the surface layer B. The coating layer is not particularly limited, but is preferably provided by an in-line coating applied during the formation of the polyester film. When the surface layer B does not contain particles and has a coat layer containing particles on the surface layer B, the surface of the coat layer has a region for the same reason as the above-mentioned region surface average roughness (Sa) of the surface layer B. The surface average roughness (Sa) is preferably in the range of 1 to 40 nm. More preferably, it is in the range of 5 to 35 nm.

From the viewpoint of reducing pinholes, it is preferable not to use a recycled raw material or the like in the surface layer A, which is the layer on which the release layer is provided, in order to prevent the mixing of inorganic particles such as lubricant.

The thickness ratio of the surface layer A, which is the layer on which the release layer is provided, is preferably 20% or more and 50% or less of the total thickness of the base film. When it is 20% or more, it is not easily affected by the particles contained in the surface layer B or the like from the inside of the film, and it is easy for the region surface average roughness Sa to satisfy the above range, which is preferable. When it is 50% or less of the thickness of the entire layer of the base film, the ratio of the recycled raw material used in the surface layer B can be increased, and the environmental load is small, which is preferable.

Further, from the viewpoint of economic efficiency, 50 to 90% by mass of film scraps or recycled raw materials for PET bottles can be used for the layers other than the surface layer A (surface layer B or the above-mentioned intermediate layer C). Even in this case, it is preferable that the type and amount of the lubricant contained in the B layer, the particle size, and the region surface average roughness (Sa) satisfy the above ranges.

Further, a film before or after uniaxial stretching in the film forming process on the surface of the surface layer A and / or the surface layer B in order to improve the adhesion of the release layer to be applied later and prevent charging. A coat layer may be provided on the surface, or a corona treatment or the like may be applied.

(Release layer)
The release layer in the present invention is preferably formed by curing a composition containing a binder component (a) and a silsesquioxane component (b). Here, in the present invention, the binder component (a) and the silsesquioxane component (b) are considered to have changed the structure of the compound in the state after being cured in the coating layer, but the changed structure. Since it is extremely difficult to accurately express and describe the composition itself, as described above, the composition in which the release layer contains the binder component (a) and the silsesquioxane component (b) is cured. It is expressed as.

(Binder component (a))
The binder component (a) is preferably a component that can be cured under heat or irradiation with active energy rays to form a coating film having a high elastic modulus. Examples of the thermosetting binder component include an epoxy-based substance and a melamine-based substance, but it is preferable to use a melamine-based substance from the viewpoint of reactivity. As the active energy ray-curable binder component, a radical curable substance and a cationic curable substance are preferable, and each can be preferably used.

The radical curable substance in the present invention is preferably a substance having at least one reactive functional group selected from an acryloyl group, a methacryloyl group, an alkenyl group and a thiol group and curable under ultraviolet irradiation. The cationically curable substance preferably has at least one reactive functional group selected from an epoxy group, a vinyl ether group, an alicyclic epoxy group, and an oxetanyl group, and is cured under ultraviolet irradiation. The alkenyl group in the present invention refers to a group having 2 to 10 carbon atoms such as a vinyl group, an allyl group, a propenyl group and a hexenyl group.

The melamine-based substance used as the binder component (a) can be a general substance and is not particularly limited, but is obtained by condensing melamine and formaldehyde, and has a triazine ring and a methylol group and / or an alkoxymethyl group in one molecule. It is preferable to have one or more of each. Specifically, a compound obtained by dehydrating and condensing a methylalcohol melamine derivative obtained by condensing melamine and formaldehyde with methyl alcohol, ethyl alcohol, isopropyl alcohol, butyl alcohol and the like as lower alcohols to etherify them is preferable. Examples of the methylolated melamine derivative include monomethylol melamine, dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, and hexamethylol melamine. One type may be used or two or more types may be used.

The release layer in the present invention preferably has a high crosslink density and a high elastic modulus in order to suppress deformation of the release layer. Therefore, as the melamine-based substance used for the release layer, it is preferable to use hexamethylol melamine having many cross-linking points in one molecule, which can increase the cross-linking density of the release layer.

When an ether compound obtained by dehydration condensation reaction using alcohol as a methylol melamine derivative is used as the melamine-based substance used for the release layer of the present invention, hexamethoxy obtained by dehydration condensation with methyl alcohol from the viewpoint of reactivity. Methylmelamine is particularly preferred.

When a melamine-based substance is used for the release layer of the present invention, it is preferable to add a catalyst in order to promote the cross-linking reaction of the melamine-based substance. The catalyst to be used is not particularly limited, but an existing acid catalyst can be used, and it is preferable to use a carboxylic acid-based catalyst. Metal salt-based, phosphoric acid ester-based, and sulfonic acid-based ones can be preferably used. Further, a block type catalyst in which the acid moiety is blocked can also be used.

As the carboxylic acid-based catalyst, for example, benzoic acid, acetic acid, formic acid, oxalic acid, propionic acid and derivatives thereof can be used. It is preferable to use a carboxylic acid-based catalyst because the curl of the release film due to an excessive increase in the cross-linking density can be suppressed by appropriate reactivity. In particular, 4-methylbenzoic acid is inexpensive, easily available, and easy to use.

The radical curable substance used as the binder component (a) may be a monomer, an oligomer, or a polymer, but examples thereof include acrylates, methacrylates, urethane acrylates, acrylamides, allyl compounds, metalryl compounds, and maleimide compounds from the viewpoint of reactivity. Acrylate, methacrylate, urethane acrylate, allyl compound, and metallic compound are preferable, and acrylate, methacrylate, and urethane acrylate are particularly preferable.

The radical curable substance used as the binder component (a) may be a monomer, an oligomer or a polymer, but it is preferable to use a monomer or an oligomer from the viewpoint of solubility in an organic solvent and handleability. These may be used alone or in combination of two or more.

When a monomer is used as the (meth) acrylate, for example, trimethylolpropantri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol. Examples thereof include tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ethoxylated isocyanuric acid tri (meth) acrylate, and caprolactone-modified dipentaerythritol hexa (meth) acrylate.

When an oligomer is used as the (meth) acrylate, examples thereof include a polyfunctional (meth) acrylate oligomer, a polyester acrylate-based oligomer, an epoxy acrylate-based oligomer, a polyether acrylate-based oligomer, a polybutadiene acrylate-based oligomer, and a silicone acrylate-based oligomer. ..

The urethane acrylate used in the present invention refers to a urethane acrylate having a urethane bond in the molecular chain and one or more radical curable functional groups selected from an acryloyl group and a methacryloyl group. The synthesis method is not particularly limited, but it can be obtained, for example, by reacting a polyhydric alcohol or an organic polyisocyanate with a hydroxy acrylate.

Examples of the polyhydric alcohol include neopentyl glycol, 3-methyl-1,5-pentanediol, ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, trimethylolpropane, and pentaerythritol. , Tricyclodecanedimethylol, bis- [hydroxymethyl] -cyclohexane, etc .; Polyester polyol obtained by reaction with (phthalic acid, etc.); Polycaprolactone polyol obtained by reaction of the above polyhydric alcohol with ε-caprolactone; Obtained by reaction of polycarbonate polyol (for example, 1,6-hexanediol and diphenyl carbonate). Polyester diols and the like); and polyether polyols. Examples of the polyether polyol include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide-modified bisphenol A and the like.

Examples of the organic polyisocyanate include isocyanate compounds such as isophorone diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, xylene diisocyanate, diphenylmethane-4,4'-diisocyanate, and dicyclopentanyl isocyanate, adducts of these isocyanate compounds, or these. Examples thereof include a multimer of isocyanate.

Examples of the hydroxy (meth) acrylate compound include pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and hydroxyethyl (meth). ) Acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, dimethylolcyclohexylmono (meth) acrylate, hydroxycaprolactone (meth) acrylate and the like can be mentioned. Of these, pentaerythritol tri (meth) acrylate and dipentaerythritol penta (meth) acrylate are preferable from the viewpoint of hardness.

As the urethane acrylate used in the present invention, commercially available ones can also be used. Examples of commercially available products are: UV1700B (10 functionals), UV7620EA (9 functionals), UV7610B (9 functionals), UV7600B (6 functionals), UV7650B (5 functionals), manufactured by Nippon Kayaku Co., Ltd .: DPHA40H (10 functionals), UX5003 (6 functionals), Arakawa Chemical Industry Co., Ltd .: Beam set 577 (6 functionals), Taisei Fine Chemicals Co., Ltd .: 8UX-015A (15 functionals), and Shin Nakamura Chemical Industry Co., Ltd .: U15HA (15) Sensory) and the like.

The compound having an alkenyl group used for the release layer of the present invention is not particularly limited, and a general compound can be preferably used. Examples of commercially available products are: TAIC (registered trademark) triallyl isocyanurate (trifunctional) manufactured by Nihon Kasei, LDAIC (bifunctional), TA-G (4 functional), DD-1 manufactured by Shikoku Kasei. (4 sensuality) and the like.

When a radical curable substance is used for the release layer of the present invention, it is preferable to use a radical initiator in order to proceed the reaction. As the radical initiator, both a thermal radical initiator and a photoradical initiator can be preferably used, but it is preferable to use a photoradical initiator because the amount of heat during processing can be suppressed. The initiator to be used may be one type or two or more types, and a photoradical initiator and a thermal radical initiator may be used at the same time.

The radical initiator is not particularly limited and a general one can be used. Specific examples include benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, methyl benzoin benzoate, benzoin dimethyl ketal, 2,4-diethylthioxanthone. , 1-Hydroxycyclohexylphenyl ketone, benzyldiphenylsulfide, tetramethylthium monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, β-chloranthraquinone, (2,4,6-trimethylbenzyldiphenyl) phosphine Examples thereof include oxide, 2-benzothiazole-N, N-diethyldithiocarbamate and the like.

As the radical initiator, α-hydroxyalkylphenone and α-aminoalkylphenone, which are said to be particularly excellent in surface curability, can be suitably used for suppressing oxygen inhibition. Examples of α-hydroxyalkylphenone are 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl}-. 2-Methyl Propane-1-one, 2-Hydroxy-2-Methyl-1-phenyl-Propane-1-one, 1- [4- (2-Hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl- 1-Propane-1-one and the like can be mentioned. Examples of α-aminoalkylphenone are 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopro. Examples thereof include pan-1-one, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholyl) phenyl] -1-butanone and the like.

When a photoradical initiator is used, the addition of a sensitizer can promote the absorption of active energy rays and further improve the curability. The sensitizer is not particularly limited and a general one is used, but an anthracene derivative and a naphthalene derivative are preferable. One kind or two or more kinds of sensitizers may be used.

The amount of the radical initiator added is preferably 0.1% by mass or more and 20% by mass or less, preferably 0.5% by mass or more and 10% by mass or less, based on the total solid content in the release layer. It is more preferable, and it is most preferable that it is 1% by mass or more and 8% by mass or less. When it is 0.1% by mass or more, the amount of radicals generated is insufficient and there is no possibility of insufficient curing, which is preferable. When the content is 20 parts by mass or less, the amount of the radical initiator residue contained in the release layer is reduced, and it is possible to suppress deterioration of peelability and transfer to the ceramic green sheet to be molded, which is preferable.

The amount of the sensitizer added is preferably 0.1 to 5 times the mass of the photoradical initiator. More preferably, it is 0.1 to 2 times. When it is larger than 0.1 times, a sufficient sensitizing effect can be obtained, which is preferable. When it is smaller than 5 times, it is preferable because there is no possibility that the absorption of active energy rays of the photo-radical initiator is hindered and the amount of generated radicals is insufficient.

The cationically curable substance used as the binder component (a) can be a general substance and is not particularly limited, but is preferably a vinyl ether compound or a cyclic ether compound, and among them, an oxetane compound or a compound having an epoxy group is used. Is preferable. Examples of oxetane compounds include aliphatic, aromatic and alicyclic compounds. Examples of the compound having an epoxy group include glycidyl ether type, glycidyl amine type, and glycidyl ester type epoxies, and alicyclic epoxies. In particular, glycidyl ether type epoxies and alicyclic epoxies are preferable. From the viewpoint of sex, it is most preferable to use an alicyclic epoxy. Examples of the glycidyl ether type epoxy compound include aromatic glycidyl ether represented by bisphenol type epoxy resin and cresol novolac type epoxy resin, and aliphatic glycidyl ether represented by hydrogenated A type glycidyl ether and butyl glycidyl ether. Be done. Examples of the alicyclic epoxy include those having an ester skeleton, a dicyclopentadiene skeleton, a fluorene skeleton, an ε-caprolactone skeleton, and the like, and may have other skeletons.

As the alicyclic epoxy compound, a commercially available one can also be used. Examples of commercially available products include Cyclomer (registered trademark) M100, Celoxide (registered trademark) 2000 (above, Daicel, monofunctional), Celoxide (registered trademark) 2021P, 2081 (above, Daicel, bifunctional). , Epolyde (registered trademark) GT401 (manufactured by Daicel, 4-functional), EHPE (registered trademark) 3150 (manufactured by Daicel, polyfunctional) and the like.

As the oxetane compound, a commercially available compound can also be used. Examples of commercially available products include Aron Oxetane (registered trademark) OXT-101, 212 (above, Toagosei Co., Ltd., monofunctional) OXT221, OXT-121 (above, Toagosei Co., Ltd., bifunctional), ETERNCOL (registered trademark). ) EHO, OXMA (above, manufactured by Ube Kosan Co., Ltd., 1 sensory) OXTP, OXBP (above, manufactured by Ube Kosan Co., Ltd., 2 sensory) and the like.

The release layer in the present invention preferably has an increased crosslink density in order to suppress erosion of the release layer by an organic solvent. Therefore, any of a polymer, an oligomer, and a monomer may be used as the cationically curable substance, but it is particularly preferable to use a monomer because the number of cross-linking points per constant mass increases and the cross-linking density can be increased.

When a cationically curable substance is used for the release layer in the present invention, it is preferable to use an acid generator in order to promote the cationic polymerization reaction. The acid generator to be used is not particularly limited and a general one is used, but it is preferable to use a photoacid generator that generates an acid under irradiation with active energy rays because the amount of heat during processing can be suppressed. .. By using a general acid such as a sulfonic acid type or a carboxylic acid type, it is possible to obtain a release layer having a high crosslink density that can suppress the erosion of the organic solvent, but since a high processing temperature is required, a high processing temperature is required. The surface of the release layer may be roughened due to heat shrinkage of the raw material and deterioration of smoothness. In addition, metal salt-based, phosphoric acid ester-based, and block-type acid generators in which the acid moiety is blocked can also be used. Most preferred from.

As the photoacid generator, it is preferable to use a salt composed of onium ions and non-nucleophilic anions from the viewpoint of reactivity. Further, an organic metal complex typified by an iron arene complex, a carbocation salt typified by tropylium may be used, and phenols substituted with an anthracene derivative or an electron-withdrawing group, for example, pentafluorophenol may be used. ..

When the salt composed of the onium ion and the non-nucleophilic anion is used as the photoacid generator, for example, iodonium, sulfonium, and ammonium can be used as the onium ion. As the organic group of the onium ion, triaryl, diaryl (monoalkyl), monoaryl (dialkyl), or trialkyl may be used, and benzophenone, 9-fluorene may be introduced, or other organic groups may be used. good. As the non-nucleophilic anion, hexafluorophosphorate, hexafluoroantimonate, hexafluoroborate, and tetra (pentafluorophenyl) borate are preferably used. Further, a tetra (pentafluorophenyl) gallium ion or an anion in which some of the fluorine anions are replaced with a perfluoroalkyl group or an organic group may be used, or other anion components may be used.

When the photoacid generator is used, by adding a sensitizer, the reactivity of the polymerization reaction can be enhanced and the erosion of the release layer by the organic solvent can be further suppressed. The sensitizer is not particularly limited and a general one is used, but an anthracene derivative and a naphthalene derivative are preferable. One kind or two or more kinds of sensitizers may be used.

The amount of the photoacid generator added to the coating liquid containing the release layer forming composition is 0.1 to 10% by mass, more preferably 0.5, based on the total solid content in the release layer. ~ 8% by mass. More preferably, it is 1 to 5% by mass. When it is 0.1% by mass or more, the amount of generated acid is insufficient and there is no possibility of insufficient curing, which is preferable. Further, when the content is 10% by mass or less, the amount of generated acid becomes appropriate, and the amount of acid transferred to the ceramic green sheet to be molded can be suppressed, which is preferable.

(Silsesquioxane component (b))
The present inventors show excellent peelability to an ultrathin ceramic green sheet by forming a release layer containing a binder component (a) and a certain amount of silsesquioxane component (b). I found that. The content of the silsesquioxane component (b) contained in the release layer is 0.01% by mass or more when the mass of the total solid content constituting the release layer forming composition is 100% by mass. It is preferably 60% by mass, more preferably 0.01% by mass to 30% by mass, further preferably 0.01% by mass to 25% by mass, and 0.01% by mass to 20% by mass. Is the most preferable. It is preferable that the content of the silsesquioxane component (b) is 0.01% by mass or more because it is excellent in peelability. When it is 60% by mass or less, there is no possibility that the crosslink density is lowered, and it is preferable because it is excellent in hardness and peelability.

The silsesquioxane component (b) in the present invention refers to silsesquioxane having a unit composition formula of [(RSiO _3/2 ) _n ]. At this time, R refers to an organic functional group and is not particularly limited, and is a non-reactive functional group such as a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a polyorganosiloxane group, a hydroxyl group, a carboxyl group or an amino group. Examples thereof include reactive functional groups such as thiol group, epoxy group, alicyclic epoxy group, oxetanyl group, vinyl ether group, acryloyl group, methacryloyl group and alkenyl group. R is not limited to one type, and may have two or more types of organic functional groups per molecule.

The silsesquioxane component (b) is chemically stable and excellent in solvent resistance as compared with a silicone-based mold release additive typified by polyorganosiloxane. Therefore, there is no possibility that the release layer is eroded by the organic solvent used at the time of molding the ceramic green sheet or printing the internal electrode, and the release layer having excellent peelability can be obtained.

Further, the silsesquioxane component (b) has a rigid skeleton as compared with a silicone-based mold release agent typified by polyorganosiloxane, and has characteristics similar to those of an inorganic material. Therefore, compared to the silicone-based mold release agent, the hardness of the release layer surface can be increased, the release layer is less likely to be deformed when the ultrathin ceramic green sheet is peeled off, and excellent peelability is exhibited.

Examples of the skeletal structure of silsesquioxane include a random structure, a complete cage structure, a ladder structure, and an incomplete cage structure. The silsesquioxane component (b) in the present invention may be only one type of silsesquioxane having a skeletal structure or a mixture of two or more kinds of silsesquioxane having a skeletal structure. From the viewpoint of ease of handling, ease of handling, and cost, a mixture of silsesquioxane having two or more types of skeletal structures is preferable.

The method for synthesizing the silsesquioxane component (b) is not particularly limited, but has a hydrolyzable group such as a hydrogen atom, a hydroxyl group, an alkoxy group, a cycloalkoxy group, an aralkyloxy group, an aryloxy group, a chloro group and a bromo group. An example is a method of hydrolyzing and condensing a trifunctional silane in the presence of an acidic or basic catalyst. For the hydrolysis / condensation reaction, two or more kinds of trifunctional silanes may be used, or four or more kinds of tetrafunctional silanes having hydrolyzable groups may be used. The trifunctional silane preferably has the above-mentioned organic functional group R.

The weight average molecular weight (Mw) of the silsesquioxane component (b) used in the present invention is preferably 1000 to 100,000, more preferably 1000 to 50,000. A weight average molecular weight of 1000 or more is preferable because it has excellent solvent resistance. When the molecular weight is 100,000 or less, there is no possibility of an extreme increase in viscosity or crystallization, and handling is easy, which is preferable.

In the present invention, by using the silsesquioxane component (b), excellent peelability to the ultrathin ceramic green sheet can be obtained, but the silsesquioxane component having a polyorganosiloxane group in the molecule is used. As a result, even better peelability can be obtained. It is most preferable to use a polydimethylsiloxane group as the polyorganosiloxane group. The silsesquioxane component (b) having a polyorganosiloxane group in the molecule described in the present specification includes the case where the polyorganosiloxane is present at the end of the molecule and the case where the polyorganosiloxane is present in the molecular skeleton. There is.

The silsesquioxane component (b) preferably has a reactive functional group capable of cross-linking with the binder (a). By using the silsesquioxane component (b) having a crosslinkable reactive group with the binder (a), it is incorporated into the crosslinked structure of the binder (a) at the time of curing to form a release layer having a higher surface hardness. It is preferable because it can be used. Further, it is preferable because the Si-containing component such as the silsesquioxane component (b) is less likely to be transferred to the ceramic green sheet and the reliability of the ceramic capacitor is not deteriorated.

When a melamine-based substance is used as the binder component (a), the silsesquioxane component (b) is one or more reactive functional groups selected from a hydroxyl group, a carboxyl group, an amino group, a hydrosilyl group, an alkoxyl group, an epoxy group and the like. Having a group is more preferable from the viewpoint of reactivity with a melamine-based substance, and it is particularly preferable to have at least one reactive functional group selected from a hydroxyl group, a carboxyl group, an amino group and a hydrosilyl group.

When a radical curable substance is used as the binder component (a), the silsesquioxane component (b) contains at least one reactive functional group selected from an acryloyl group, a methacryloyl group, an alkenyl group, a thiol group and a maleimide group. It is preferable to have at least one reactive functional group selected from an acryloyl group, a methacryloyl group, an alkenyl group and a thiol group from the viewpoint of reactivity with a radical curable substance.

When a cationically curable substance is used as the binder component (a), the silsesquioxane component (b) has at least one reactive functional group selected from an epoxy group, an alicyclic epoxy group, an oxetanyl group and a vinyl ether group. Is preferable from the viewpoint of reactivity with a cationically curable substance, and it is particularly preferable to have at least one reactive functional group selected from an epoxy group, an alicyclic epoxy group and an oxetanyl group.

As the silsesquioxane component (b), commercially available ones can also be preferably used. Examples of commercially available products include composelan (registered trademark) SQ106, 107, 109 (above, manufactured by Arakawa Chemical Industry Co., Ltd., containing thiol group), composelan (registered trademark) SQ506, 508, 510, 511 (above, Arakawa Chemical). Industrial Co., Ltd., containing epoxy group), AC-SQ TA100 (manufactured by Toa Synthetic Co., Ltd., containing acryloyl group), MAC-SQ TM-100 (manufactured by Toa Synthetic Co., Ltd., containing methacryloyl group), AC-SQ SI-20 (Toa Synthetic) , Polydimethylsiloxane group, containing acryloyl group), MAC-SQ SI-20 (manufactured by Toa Synthetic Co., Ltd., containing polydimethylsiloxane group, methacryloyl group), OX-SQ TX100 (manufactured by Toa Synthetic Co., Ltd., containing oxetanyl group), OX-SQ SI-20 (manufactured by Toa Synthetic Co., Ltd., containing polydimethylsiloxane group and oxetanyl group), PSS-octa [(1,2-epoxide-4-ethylcyclohexyl) dimethylsiloxy] substituent (manufactured by SIGMA-ALDRICH), (Contains an alicyclic epoxy group), PSS-octavinyl substituent (manufactured by SIGMA-ALDRICH, containing a vinyl group) and the like.

(Other ingredients)
The release layer in the present invention may contain particles having a particle size of 1 μm or less, but it is preferable not to contain particles or the like that form protrusions from the viewpoint of pinhole generation.

An adhesion improver, an additive such as an antistatic agent, or the like may be added to the release layer in the present invention as long as the effect of the present invention is not impaired. Further, in order to improve the adhesion to the substrate, it is also preferable to perform pretreatment such as anchor coating, corona treatment, plasma treatment, and atmospheric pressure plasma treatment on the surface of the polyester film before providing the release coating layer.

(Other matters related to the release layer)
In the present invention, the thickness of the release layer may be set according to the purpose of use, and is not particularly limited, but preferably, the release coating layer after curing is preferably in the range of 0.01 to 2.0 μm. , More preferably 0.01 to 1.5 μm, and more preferably 0.01 to 1.0 μm. In particular, when a release layer is provided on the surface layer A of a polyester film having a surface layer A that does not substantially contain inorganic particles, the thinner the release layer, the lower the coating cost. It is preferable because it is economical and curl generation can be suppressed. Specifically, it is preferably 0.8 μm or less, and more preferably 0.5 μm or less. It is preferable that the thickness of the release layer is thicker than 0.01 μm because sufficient peeling performance can be obtained. If it is thinner than 2.0 μm, curling of the release film due to curing shrinkage is unlikely to occur, so that there is no risk of causing uneven thickness of the ceramic green sheet and deterioration of electrode printing accuracy, which is preferable.

The surface of the release layer of the release film of the present invention is preferably flat so as not to cause defects in the ceramic green sheet coated and molded on the release layer, and the region surface average roughness (Sa) is 7 nm or less. It is preferable to have. Further, it is more preferable that the Sa is satisfied and the maximum protrusion height (P) on the surface of the release layer is 100 nm or less. It is particularly preferable that the region surface average roughness (Sa) is 5 nm or less, and most preferably the region surface average roughness (Sa) is 80 nm or less on the above-mentioned area and the maximum protrusion height (P) is 80 nm or less. When the region surface roughness is 7 nm or less, defects such as pinholes do not occur when the ceramic green sheet is formed, and the yield is good, which is preferable. It can be said that the smaller the region surface average roughness (Sa) is, the more preferable it is, but it may be 0.1 nm or more, or 0.3 nm or more. It can be said that the smaller the maximum protrusion height (P) is, the more preferable it is, but it may be 1 nm or more, or 3 nm or more.

The release film of the present invention preferably has a peeling force of 0.3 mN / mm or more and 4.0 mN / mm or less, 0.5 mN / mm or more, and 3.0 mN / mm when peeling the ceramic green sheet. It is more preferably 0.5 mN / mm or more, and further preferably 2.0 mN / mm or less. When the peeling force is 0.3 mN / mm or more, the peeling force is too light and there is no possibility that the ceramic green sheet will float during transportation, which is preferable. When the peeling force is 4.0 mN / mm or less, the ceramic green sheet is not damaged at the time of peeling and there is no possibility of causing defects, which is preferable.

The release film of the present invention is preferable because the higher the solvent resistance, the more the erosion of the release layer by an organic solvent such as toluene during ceramic sheet processing and electrode printing can be suppressed. The solvent resistance can be confirmed by evaluating the difference in the surface state of the release layer before and after the release film is immersed in the organic solvent. As the organic solvent, it is preferable to use toluene, which is used for a general ceramic slurry or a conductive paste, assuming ceramic green sheet processing or electrode printing. An example of a method for evaluating the surface state of the release layer is evaluation based on the contact angle, and it is preferable that the change in the contact angle on the surface of the release layer before and after immersion in toluene is small.

The type of liquid plucking used when measuring the contact angle is not particularly limited, and water, bromonaphthalene, ethylene glycol, etc. can be preferably used, but the difference in the surface state of the release layer can be seen more prominently. It is most preferable to use diiodomethane which can be used.

When diiodomethane was used as the liquid picker used to measure the contact angle, the diiodomethane contact angle θ ₁ on the surface of the release layer and the contact angle θ on the surface of the release layer after the release film was immersed in toluene at room temperature for 5 minutes. The smaller the value of the difference between ₂ (θ ₁ − θ ₂ ), the better the solvent resistance of the release layer surface, which is preferable. Specifically, the absolute value is preferably 3.0 ° or less, more preferably 2.0 ° or less, and most preferably 1.0 ° or less. When the temperature is 3.0 ° or less, erosion of the release layer by the organic solvent during ceramic green sheet processing or electrode printing is suppressed, and there is no possibility that the peeling force is increased or the peeling uniformity is impaired, which is preferable. The difference (θ ₁ − θ ₂ ) between the diiodomethane contact angle θ ₁ on the surface of the release layer and the contact angle θ ₂ on the surface of the release layer after the release film is immersed in toluene at room temperature for 5 minutes is most preferably 0 °. The absolute value may be 0.05 ° or more, or 0.1 ° or more.

In the release film of the present invention, the higher the hardness of the release layer surface, the less likely the release layer is deformed when the ultrathin ceramic green sheet is peeled off, and the release layer can be peeled off with a low and uniform force. preferable. Further, the higher the hardness, the less likely it is that the release layer will be scratched during roll transport, and there is no risk of partial increase in peeling force or uneven thickness of the ceramic green sheet, which is preferable. The hardness of the release layer surface can be evaluated by the degree of scratches (scratch resistance) when the release layer surface is rubbed with steel wool. The degree of scratches (scratch resistance) can be evaluated by the number of scratches formed when the release layer is rubbed with steel wool, and the smaller the number of scratches, the higher the hardness of the release layer surface, which is preferable.

In the release film of the present invention, it is preferable that the amount of the release agent component transferred to the ceramic green sheet after peeling is small. For the transfer amount of the release agent component, PVB, which is one of the binder components contained in the ceramic green sheet, is pseudo-applied and molded on the release film, and the Si strength of the release layer before and after peeling is fluorescent X. It can be evaluated by measuring with a line. More specifically, when the Si strength of the release layer surface is Si (front) and the Si strength of the release surface of the release film after coating / peeling the PVB sheet is Si (rear), Si (rear). The value of front) -Si (rear) was used as the transfer amount. The transfer amount at this time is preferably 0.20 Kcps or less, and more preferably 0.10 or less. When the transfer amount is 0.20 Kcps or less, there is no possibility of deteriorating the reliability of the ceramic capacitor, which is preferable.

(Method of forming the release layer)
In the present invention, the method for forming the release layer is not particularly limited, and a coating liquid in which a composition containing a releaseable substance or the like is dissolved or dispersed is applied to one surface of a polyester film as a base material to develop the coating solution. Then, a method is used in which a solvent or the like is removed by drying, heat-dried, and then cured by irradiation with active energy rays or heat.

When a thermosetting substance is used as the binder component (a), the drying temperatures during solvent drying and thermosetting are preferably 100 ° C. or higher and 180 ° C. or lower, and 100 ° C. or higher and 160 ° C. or lower. More preferably, it is 100 ° C. or higher and 140 ° C. or lower is most preferable. The heating time is preferably 30 seconds or less, more preferably 20 seconds or less. When the temperature is 180 ° C. or lower, the flatness of the film is maintained and the possibility of causing uneven thickness of the ceramic green sheet is small, which is preferable. When the temperature is 140 ° C. or lower, the film can be processed without impairing the flatness of the film, and the possibility of causing uneven thickness of the ceramic green sheet is further reduced, which is particularly preferable. If the temperature is higher than 100 ° C., the curing reaction does not proceed sufficiently and the elastic modulus of the release layer does not decrease, which is preferable.

When an active energy ray-curable substance (that is, a radical curable substance or a cationic curable substance) is used as the binder component (a), the drying temperature for solvent drying is preferably 50 ° C. or higher and 100 ° C. or lower. It is more preferable that the temperature is 60 ° C. or higher and 95 ° C. or lower. The heating time is preferably 30 seconds or less, more preferably 20 seconds or less. When the temperature is 100 ° C. or lower, the thermal load on the film is suppressed, appearance defects due to heat shrinkage of the film are less likely to occur, and there is less risk of causing uneven thickness of the ceramic green sheet, which is preferable. When the temperature is 95 ° C. or lower, the thermal load on the film is further reduced, processing can be performed without impairing the flatness of the film, and the possibility of causing uneven thickness of the ceramic green sheet is further reduced, which is particularly preferable. If the temperature is higher than 50 ° C., the diluting solvent used for coating will not be sufficiently dried, and there is no possibility of process contamination and the like, which is preferable.

Active energy rays As the active energy rays used for curing the curable substance, ultraviolet rays, electron beams, X-rays and the like can be used, but ultraviolet rays are preferable because they are easy to use. The amount of ultraviolet rays to be irradiated is preferably 30 to 300 mJ / cm ² in terms of integrated light amount, and more preferably 30 to 200 mJ / cm ² . It is preferable that the setting is 30 mJ / cm ² or more because the curing of the active energy ray-curable substance proceeds sufficiently. It is preferable that the speed is 300 mJ / cm ² or less because the speed at the time of processing can be improved and the release film can be economically produced.

In the present invention, the surface tension of the coating liquid when the release layer is applied is not particularly limited, but is preferably 30 mN / m or less. By setting the surface tension as described above, the coatability after coating can be improved, and the unevenness of the coating film surface after drying can be reduced.

In the present invention, the coating liquid for applying the release coating layer is not particularly limited, but it is preferable to add a solvent having a boiling point of 90 ° C. or higher. By adding a solvent having a boiling point of 90 ° C. or higher, bumping during drying can be prevented, the coating film can be leveled, and the smoothness of the coating film surface after drying can be improved. The amount to be added is preferably about 10 to 80% by mass with respect to the entire coating liquid.

Any known coating method can be applied as the coating method, for example, a roll coating method such as a gravure coating method or a reverse coating method, a bar coating method such as a wire bar, a die coating method, a spray coating method, or an air knife. Conventionally known methods such as the coat method can be used.

(Ceramic green sheet and ceramic capacitor)
Generally, a monolithic ceramic capacitor has a rectangular parallelepiped ceramic prime field. Inside the ceramic prime field, first internal electrodes and second internal electrodes are alternately provided along the thickness direction. The first internal electrode is exposed on the first end face of the ceramic prime field. A first external electrode is provided on the first end face. The first internal electrode is electrically connected to the first external electrode at the first end face. The second internal electrode is exposed on the second end face of the ceramic prime field. A second external electrode is provided on the second end face. The second internal electrode is electrically connected to the second external electrode at the second end face.

The release film for manufacturing a ceramic green sheet of the present invention is used for manufacturing such a multilayer ceramic capacitor. For example, it is manufactured as follows. First, the release film of the present invention is used as a carrier film, and a ceramic slurry for forming a ceramic prime field is applied and dried. An ultra-thin product having a thickness of 0.2 to 1.0 μm is required for the ceramic green sheet. A conductive layer for forming the first or second internal electrode is printed on the coated and dried ceramic green sheet. A ceramic green sheet, a ceramic green sheet on which a conductive layer for forming a first internal electrode is printed, and a ceramic green sheet on which a conductive layer for forming a second internal electrode is printed are appropriately laminated and pressed. Thereby, a mother laminated body is obtained. The mother laminate is divided into a plurality of pieces to prepare a raw ceramic prime field. A ceramic prime is obtained by firing a raw ceramic prime. After that, the multilayer ceramic capacitor can be completed by forming the first and second external electrodes.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. The characteristic values used in the present invention were evaluated using the following method.

(Intrinsic viscosity of polyester resin (dl / g))
According to JIS K 7637-5, a mixed solvent of phenol (60% by mass) and 1,1,2,2-tetrachloroethane (40% by mass) was used as a solvent, and the measurement was carried out at 30 ° C.

(Base film thickness)
Using a millitron (electron micro-indicator), four 5 cm square samples were cut from any four points of the film to be measured, and each five points (20 points in total) were measured and the average value was taken as the thickness.

(Release layer thickness)
The cut release film was embedded in a resin and ultrathin sectioned using an ultramicrotome. Then, using a JEM2100 transmission electron microscope manufactured by JEOL Ltd., observation was performed directly at a magnification of 20,000 times, and the film thickness of the release layer was measured from the observed TEM image.

(Region surface roughness Sa, maximum protrusion height P)
It is a value measured under the following conditions using a non-contact surface shape measurement system (VertScan R550H-M100 manufactured by Ryoka System Co., Ltd.). For the region surface average roughness (Sa), the average value of 5 measurements was adopted, and for the maximum protrusion height (P), the maximum value of 5 times excluding the maximum value and the minimum value was used after measuring 7 times.
(Measurement condition)
・ Measurement mode: WAVE mode ・ Objective lens: 10x ・ 0.5 × Tube lens ・ Measurement area 936μm × 702μm
(Analysis conditions)
・ Surface correction: 4th correction ・ Interpolation processing: Complete interpolation

(Pinhole evaluation of ceramic green sheet)
The composition composed of the following materials was stirred and mixed, and dispersed with zirconia beads having a diameter of 0.5 mm for 30 minutes using a bead mill to obtain a ceramic slurry.
Toluene 76.3 parts by mass Ethanol 76.3 parts by mass Barium titanate (HPBT-1 manufactured by Fuji Titanium Industry Co., Ltd.) 35.0 parts by mass Polyvinyl butyral (Eslek (registered trademark) BM-S manufactured by Sekisui Chemical Co., Ltd.) 3.5 parts by mass DOP (dioctyl phthalate) 1.8 parts by mass Next, apply an applicator to the release surface of the obtained release film sample so that the dried ceramic green sheet has a thickness of 0.8 μm, and at 90 ° C, 2 After drying for a minute, the release film was peeled off to obtain a ceramic green sheet. In the central region of the obtained ceramic green sheet in the film width direction, shine light from the opposite surface of the coated surface of the ceramic slurry within a range of 25 cm ² , observe the occurrence of pinholes through which light can be seen, and use the following criteria. It was judged visually. The measurement was carried out 5 times, and the average value was adopted.
⊚: No pinholes ○: Almost no pinholes (approximate: 2 or less pinholes per measured area)
Δ: Pinholes may occur (approximate: 3 or more and 5 or less pinholes per measurement area)
×: There are many pinholes

(Evaluation of peelability of ceramic green sheet)
The composition composed of the following materials was stirred and mixed, and dispersed with zirconia beads having a diameter of 0.5 mm for 60 minutes using a bead mill to obtain a ceramic slurry.
Toluene 38.3 parts by mass Ethanol 38.3 parts by mass Barium titanate (HPBT-1 manufactured by Fuji Titanium) 64.8 parts by mass Polyvinyl butyral 6.5 parts by mass (Sekisui Chemical Co., Ltd. Eslek (registered trademark) BM-S )
DOP (Dioctyl phthalate) 3.3 parts by mass Next, apply the dried ceramic green sheet to the release surface of the release film sample to a thickness of 1 μm using an applicator, and dry at 90 ° C for 2 minutes to make the ceramic green. The sheet was molded on a release film. The obtained release film with a ceramic green sheet was cut into a width of 30 mm and a length of 80 mm to prepare a sample for measuring the peeling force. After static elimination using an electric eliminator (Keyence, SJ-F020), a peeling tester (VPA-3, Kyowa Interface Science) is used to peel off at an angle of 90 degrees, a peeling temperature of 25 ° C, and a peeling speed of 10 m /. It peeled off at min. As for the direction of peeling, a double-sided adhesive tape (Nitto Denko Co., Ltd., No. 535A) is attached on the SUS plate attached to the peeling tester, and the ceramic green sheet side is bonded to the double-sided tape on the release film. Was fixed and peeled off by pulling the release film side. Among the obtained measured values, the average value of the peeling force having a peeling distance of 20 mm to 70 mm was calculated, and the value was used as the peeling force. The measurement was carried out a total of 5 times, and the value of the average value of the peeling force was adopted and evaluated. Judgment was made according to the following criteria from the obtained numerical values of the peeling force.
⊚: The peeling force was 2.0 mN / mm or less, and the peeling force was very light.
◯: The peeling force was larger than 2.0 mN / mm, and peeling was possible with a relatively light force of 3.0 mN / mm or less.
Δ: The peeling force was larger than 3.0 mN / mm, and peeling was possible with a light force of 4.0 mN / mm or less.
X: A force having a peeling force greater than 4.0 mN / mm was required.

(Contact angle)
Diiodomethane (droplet amount) was used on the release surface of the release film that had been allowed to stand using a contact angle meter (fully automatic contact angle meter DM-701 manufactured by Kyowa Interface Science Co., Ltd.) under the conditions of 25 ° C and 50% RH. A droplet of 0.9 μL) was prepared and the contact angle thereof was measured. As the contact angle, the contact angle 30 seconds after dropping on the release film was adopted, and the average value of the values measured 5 times was adopted.

(Contact angle after immersion in toluene)
The release film used for the measurement was cut into a size of 5 cm × 5 cm and immersed in a glass tray containing 30 mL of toluene at a liquid temperature of 25 ° C. for 5 minutes with the release side facing down. The soaked release film was taken out, air-dried for 15 minutes with the release side facing up, and then vacuum-dried at 25 ° C. overnight. The release film after immersion in toluene thus obtained was measured by the same method as the method for measuring the contact angle.

(Evaluation of contact angle change)
When the diiodomethane contact angle of the initial release layer surface before toluene immersion measured by the above method is θ ₁ and the diiodomethane contact angle of the release layer surface after toluene immersion is θ ₂ , θ ₁ − θ ₂ The absolute value was taken as the value of the contact angle change before and after immersion in toluene. The change in contact angle was evaluated based on the following criteria.
⊚: ｜ θ ₁ ― θ ₂ ｜ <1.0 °
◯: 1.0 ° ≦ ｜ θ ₁ ―θ ₂ ｜ <2.0 °
Δ: 2.0 ° ≦ ｜ θ ₁ ―θ ₂ ｜ ≦ 3.0 °
×: ｜ θ ₁ ― θ ₂ ｜ ＞ 3.0 °

(Evaluation of scratch resistance)
Steel wool (manufactured by Nippon Steel Wool Co., Ltd., Bonster (registered trademark) No. 0000) was attached to a metal pedestal weighing 200 g and having a size of 700 mm ² to create a steel wool evaluation jig. Using this jig, 10 reciprocating mold release surface sides were rubbed while applying a load of 200 g so that the release surface side of the release film and steel wool were in contact with each other. A 2 × 2 cm area in the center of the rubbed surface was observed under fluorescent light reflection, and the number of scratches visible visually was evaluated. The number of scratches was judged and evaluated according to the following criteria.
⊚: Number of scratches ≤ 1 ○: 1 <Number of scratches ≤ 10 △: 10 <Number of scratches ≤ 20 ×: 20 <Number of scratches

(Evaluation of Si transfer amount)
The composition consisting of the following materials was stirred and mixed to obtain a PVB solution.
Toluene 45.0 parts by mass Ethanol 45.0 parts by mass Polyvinyl butyral (Eslek BM-S manufactured by Sekisui Chemical Industry Co., Ltd.) 10.0 parts by mass Next, the PVB sheet after drying using an applicator on the release surface of the release film sample After coating to 10 μm and drying at 90 ° C. for 1 minute, the release film is peeled off, and the surface (release layer) of the peeled PVB sheet in contact with the release film and the PVB sheet are coated. The Si intensity of the release layer of the previous release film was measured with a fluorescent X-ray apparatus (ZSX Primus 2 manufactured by Rigaku), and the amount of Si transferred was quantified. The measurement conditions of the fluorescent X-ray apparatus were as follows.
Analysis line: Si-KA, Target: Rh4.0kW
Tube voltage: 50kV, tube current: 60mA
Filter: OUT, Attenuator: 1/1, Slit: S4, Spectral crystal: PET
Detector: PC, PHA condition: 100 (lower limit) -300 (upper limit)
Measurement diameter: 30 mm, atmosphere: Vacuum The amount of silicone transferred is the Si strength of the release surface of the release film before coating the PVB sheet to Si (front), and the release film after coating and peeling the PVB sheet. The Si strength of the mold release surface was defined as Si (rear), and the value obtained by subtracting Si (rear) from Si (front) was defined as the Si transfer amount. Judgment was made based on the following criteria from the obtained numerical values of the Si transfer amount.
⊚: 0.04 kcps or less ◯: Greater than 0.04 kcps and smaller than 0.10 kcps.
Δ: Greater than 0.10 kcps and smaller than 0.20 kcps.
X: 0.20 kcps or more

(Preparation of polyethylene terephthalate pellets (PET (I)))
As the esterification reaction device, a continuous esterification reaction device consisting of a stirrer, a splitter, a raw material charging port, and a three-stage complete mixing tank having a raw material charging port and a product outlet was used. TPA (terephthalic acid) was set to 2 tons / hour, EG (ethylene glycol) was set to 2 mol per 1 mol of TPA, antimony trioxide was set to an amount of 160 ppm of Sb atoms with respect to the PET produced, and these slurrys were esterified. It was continuously supplied to the first esterification reaction can of the chemical reaction apparatus, and reacted at normal pressure with an average residence time of 4 hours and 255 ° C. Next, the reaction product in the first esterification reaction can is continuously taken out of the system and supplied to the second esterification reaction can, and distilled off from the first esterification reaction can in the second esterification reaction can. EG is supplied in an amount of 8% by mass with respect to the produced PET, and an EG solution containing an amount of magnesium acetate tetrahydrate having an amount of Mg atoms of 65 ppm with respect to the produced PET and 40 ppm of P atoms with respect to the produced PET. An EG solution containing a certain amount of TMPA (trimethyl phosphate) was added, and the reaction was carried out at normal pressure for an average residence time of 1 hour and 260 ° C. Next, the reaction product of the second esterification reaction can was continuously taken out of the system and supplied to the third esterification reaction can, and 39 MPa (400 kg / cm ² ) was used using a high-pressure disperser (manufactured by Nippon Seiki Co., Ltd.). 0.2% by mass of porous colloidal silica having an average particle size of 0.9 μm and 1% by mass of an ammonium salt of polyacrylic acid attached per calcium carbonate after dispersion treatment with an average number of treatments of 5 passes under the pressure of 0.4% by mass of synthetic calcium carbonate having a diameter of 0.6 μm was added as an EG slurry of 10% each, and the reaction was carried out at normal pressure for an average residence time of 0.5 hours and at 260 ° C. The esterification reaction product produced in the third esterification reaction can was continuously supplied to a three-stage continuous polycondensation reaction apparatus to perform polycondensation, and a stainless steel fiber having a 95% cut diameter of 20 μm was sintered. After filtering with a filter, it was subjected to ultrafiltration and extruded into water, and after cooling, it was cut into chips to obtain PET chips with an intrinsic viscosity of 0.60 dl / g (hereinafter abbreviated as PET (I)). .. The lubricant content in the PET chip was 0.6% by mass.

(Preparation of polyethylene terephthalate pellets (PET (II)))
On the other hand, in the production of the PET chip, a PET chip having an intrinsic viscosity of 0.62 dl / g containing no inorganic particles such as calcium carbonate and silica was obtained (hereinafter abbreviated as PET (II)).

(Manufacturing method of laminated film X1)
As the laminated film X1, E5101 (Toyobo ester (registered trademark) film, manufactured by Toyobo Co., Ltd.) having a thickness of 25 μm was used. E5101 has a structure in which inorganic particles are contained in the film. The Sa of the surface layer A of the laminated film X1 was 24 nm, and the Sa of the surface layer B was 24 nm.

(Manufacturing of laminated film X2)
After the PET chips are dried, they are melted at 285 ° C., melted at 290 ° C. by a separate melt extruder extruder, and a filter obtained by sintering stainless steel fibers with a 95% cut diameter of 15 μm and a filter with a 95% cut diameter of 15 μm. A filter obtained by sintering stainless steel particles is filtered in two stages and merged in the feed block, and PET (I) is used as surface layer B (extruded surface side layer) and PET (II) is used as surface layer A. Laminated so as to form a (separation surface side layer), extruded (casting) into a sheet at a speed of 45 m / min, electrostatically adhered and cooled on a casting drum at 30 ° C by the electrostatic adhesion method, and has an inherent viscosity. Obtained an unstretched polyethylene terephthalate sheet of 0.59 dl / g. The layer ratio was adjusted so that PET (I) / PET (II) = 60% / 40% in the discharge amount calculation of each extruder. Next, the unstretched sheet was heated with an infrared heater and then stretched 3.5 times in the vertical direction at a roll temperature of 80 ° C. due to the speed difference between the rolls. Then, it was guided to a tenter and stretched 4.2 times in the lateral direction at 140 ° C. Then, in the heat fixing zone, heat treatment was performed at 210 ° C. Then, a 2.3% relaxation treatment was carried out laterally at 170 ° C. to obtain a biaxially stretched polyethylene terephthalate film X2 having a thickness of 25 μm. The Sa of the surface layer A of the obtained film X2 was 2 nm, and the Sa of the surface layer B was 29 nm.

(Example 1)
A coating liquid having the composition shown below was applied onto the surface layer A of the laminated film X1 using a wire bar so that the thickness of the release layer after drying was 1.0 μm, and dried at 90 ° C. for 15 seconds. After that, a release film for manufacturing an ultrathin ceramic green sheet was obtained by irradiating with ultraviolet rays (manufactured by Heraeus, LC6B, H bulb) having an integrated light amount of 50 mJ / cm ² . A ceramic slurry was applied to the obtained release film, and the release layer surface roughness, peelability, pinhole, scratch resistance, Si transferability, and solvent resistance were evaluated. As a result, good evaluation results were obtained. Was done.
Methyl ethyl ketone 45.00 parts by mass Isopropyl alcohol 45.00 parts by mass Binder component (a): 10-functional urethane acrylate 9.50 parts by mass (Product name: Shikou (registered trademark) UV-1700B, manufactured by Nippon Synthetic Chemical Co., Ltd., solid content 100 mass%)
Silsesquioxane component (b): PDMS, acryloyl group-containing silsesquioxane
0.10 parts by mass
(Product name: AC-SQ SI-20, manufactured by Toagosei Co., Ltd., solid content 100% by mass)
Radical initiator: 2-hirodoxy-1-{4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one 0.40 parts by mass (product name) : Omnirad127, manufactured by IGM Resins, solid content 100% by mass)

(Example 2)
The same as in Example 1 except that the silsesquioxane component (b) was changed to PDMS and silsesquioxane containing a methacryloyl group (MAC-SQ SI-20, manufactured by Toagosei Co., Ltd., solid content 100% by mass). A release film for manufacturing an ultrathin ceramic green sheet was obtained.

(Example 3)
Ultra-thin as in Example 1 except that the silsesquioxane component (b) was changed to acryloyl group-containing silsesquioxane (AC-SQ TA-100, manufactured by Toagosei Co., Ltd., solid content 100% by mass). A release film for manufacturing a layered ceramic green sheet was obtained.

(Example 4)
Ultra-thin as in Example 1 except that the silsesquioxane component (b) was changed to silsesquioxane containing a methacryloyl group (MAC-SQ TM-100, manufactured by Toagosei Co., Ltd., solid content 100% by mass). A release film for manufacturing a layered ceramic green sheet was obtained.

(Example 5)
Examples except that the silsesquioxane component (b) was changed to a thiol group-containing silsesquioxane (Composelan (registered trademark) SQ107, manufactured by Arakawa Chemical Industry Co., Ltd., solid content 72% by mass) to adjust the blending amount. A release film for manufacturing an ultrathin ceramic green sheet was obtained in the same manner as in 1.

(Example 6)
Ultra-thin layer ceramic in the same manner as in Example 1 except that the binder component (a) was changed to a hexafunctional urethane acrylate (Shikou (registered trademark) UV-7600B, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., solid content 100% by mass). A release film for manufacturing a green sheet was obtained.

(Example 7)
Mold release for manufacturing ultra-thin ceramic green sheet in the same manner as in Example 1 except that the binder component (a) was changed to a hexafunctional acrylate (A-DPH, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., solid content 100% by mass). I got a film.

(Example 8)
Ultra-thin layer ceramic green in the same manner as in Example 1 except that the binder component (a) was changed to a trifunctional allyl compound (Tyke (registered trademark), triisocyanurate, manufactured by Nihon Kasei Co., Ltd., solid content 100% by mass). A release film for sheet production was obtained.

(Example 9)
A release film for producing an ultrathin ceramic green sheet was obtained in the same manner as in Example 1 except that the coating liquid had the composition shown below.
Methyl ethyl ketone 45.00 parts by mass Isopropyl alcohol 45.00 parts by mass Binder component (a): 10-functional urethane acrylate 7.60 parts by mass (Product name: Shikou (registered trademark) UV-1700B, manufactured by Nippon Synthetic Chemical Co., Ltd., solid content 100 mass%)
Silsesquioxane component (b): PDMS, acryloyl group-containing silsesquioxane
2.00 parts by mass
(Product name: AC-SQ SI-20, manufactured by Toagosei Co., Ltd., solid content 100% by mass)
Radical initiator: 2-hirodoxy-1-{4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one 0.40 parts by mass (product name) : Omnirad127, manufactured by IGM Resins, solid content 100% by mass)

(Example 10)
A release film for producing an ultrathin ceramic green sheet was obtained in the same manner as in Example 1 except that the coating liquid had the composition shown below.
Methyl ethyl ketone 45.00 parts by mass Isopropyl alcohol 45.00 parts by mass Binder component (a): 10-functional urethane acrylate 5.60 parts by mass (Product name: Shikou (registered trademark) UV-1700B, manufactured by Nippon Synthetic Chemical Co., Ltd., solid content 100 mass%)
Silsesquioxane component (b): PDMS, acryloyl group-containing silsesquioxane
4.00 parts by mass
(Product name: AC-SQ SI-20, manufactured by Toagosei Co., Ltd., solid content 100% by mass)
Radical initiator: 2-hirodoxy-1-{4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one 0.40 parts by mass (product name) : Omnirad127, manufactured by IGM Resins, solid content 100% by mass)

(Example 11)
A release film for producing an ultrathin ceramic green sheet was obtained in the same manner as in Example 1 except that the coating liquid had the composition shown below.
Methyl ethyl ketone 45.00 parts by mass Isopropyl alcohol 45.00 parts by mass Binder component (a): 10-functional urethane acrylate 3.60 parts by mass (Product name: Shikou (registered trademark) UV-1700B, manufactured by Nippon Synthetic Chemical Co., Ltd., solid content 100 mass%)
Silsesquioxane component (b): PDMS, acryloyl group-containing silsesquioxane
6.00 parts by mass
(Product name: AC-SQ SI-20, manufactured by Toagosei Co., Ltd., solid content 100% by mass)
Radical initiator: 2-hirodoxy-1-{4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one 0.40 parts by mass (product name) : Omnirad127, manufactured by IGM Resins, solid content 100% by mass)

(Example 12)
A release film for producing an ultrathin ceramic green sheet was obtained in the same manner as in Example 1 except that the coating liquid had the composition shown below.
Methyl ethyl ketone 44.80 parts by mass Toluene 44.80 parts by mass Binder component (a): Bifunctional alicyclic epoxy monomer 9.50 parts by mass (Product name: Celoxide (registered trademark) 2021P, manufactured by Daicel, solid content 100% by mass )
Silsesquioxane component (b): PDMS, oxetanyl group-containing silsesquioxane
0.10 parts by mass
(Product name: AC-SQ SI-20, manufactured by Toagosei Co., Ltd., solid content 100% by mass)
Photoacid generator: Diphenyl [4- (Phenylthio) phenyl] Sulfonium hexafluoroantimonate 0.80 parts by mass (Product name: CPI (registered trademark) -101A, manufactured by San-Apro, solid content 50% by mass)

(Example 13)
Ultra-thin as in Example 12 except that the silsesquioxane component (b) was changed to silsesquioxane containing an oxetanyl group (OX-SQ TX-100, manufactured by Toagosei Co., Ltd., solid content 100% by mass). A release film for manufacturing a layered ceramic green sheet was obtained.

(Example 14)
A release film for producing an ultrathin ceramic green sheet was obtained in the same manner as in Example 12 except that the alicyclic epoxy group-containing silsesquioxane component (b) was changed to an alicyclic epoxy group-containing silsesquioxane.

(Example 15)
Ultra-thin layer ceramic in the same manner as in Example 12 except that the binder component (a) was changed to a tetrafunctional alicyclic epoxy monomer (Epolide (registered trademark) GT-401, manufactured by Daicel Corporation, solid content 100% by mass). A release film for manufacturing a green sheet was obtained.

(Example 16)
Ultra-thin layer ceramic green in the same manner as in Example 12 except that the binder component (a) was changed to a bifunctional oxetane compound (Aron oxetane (registered trademark) OX-221, manufactured by Toagosei Co., Ltd., solid content 100% by mass). A release film for sheet production was obtained.

(Example 17)
A release film for producing an ultrathin ceramic green sheet was obtained in the same manner as in Example 1 except that the coating liquid had the composition shown below.
Methyl ethyl ketone 44.80 parts by mass Toluene 44.80 parts by mass Binder component (a): Bifunctional alicyclic epoxy monomer 7.60 parts by mass (Product name: Celoxide (registered trademark) 2021P, manufactured by Daicel, solid content 100% by mass )
Silsesquioxane component (b): PDMS, oxetanyl group-containing silsesquioxane
2.00 parts by mass
(Product name: OX-SQ SI-20, manufactured by Toagosei Co., Ltd., solid content 100% by mass)
Photoacid generator: Diphenyl [4- (Phenylthio) phenyl] Sulfonium hexafluoroantimonate 0.80 parts by mass (Product name: CPI (registered trademark) -101A, manufactured by San-Apro, solid content 50% by mass)

(Example 18)
A release film for producing an ultrathin ceramic green sheet was obtained in the same manner as in Example 1 except that the coating liquid had the composition shown below.
Methyl ethyl ketone 44.80 parts by mass Toluene 44.80 parts by mass Binder component (a): Bifunctional alicyclic epoxy monomer 5.60 parts by mass (Product name: Celoxide (registered trademark) 2021P, manufactured by Daicel, solid content 100% by mass )
Silsesquioxane component (b): PDMS, oxetanyl group-containing silsesquioxane
4.00 parts by mass
(Product name: OX-SQ SI-20, manufactured by Toagosei Co., Ltd., solid content 100% by mass)
Photoacid generator: Diphenyl [4- (Phenylthio) phenyl] Sulfonium hexafluoroantimonate 0.80 parts by mass (Product name: CPI (registered trademark) -101A, manufactured by San-Apro, solid content 50% by mass)

(Example 19)
A release film for producing an ultrathin ceramic green sheet was obtained in the same manner as in Example 1 except that the coating liquid had the composition shown below.
Methyl ethyl ketone 44.80 parts by mass Toluene 44.80 parts by mass Binder component (a): Bifunctional alicyclic epoxy monomer 3.60 parts by mass (Product name: Celoxide (registered trademark) 2021P, manufactured by Daicel, solid content 100% by mass )
Silsesquioxane component (b): PDMS, oxetanyl group-containing silsesquioxane
6.00 parts by mass
(Product name: OX-SQ SI-20, manufactured by Toagosei Co., Ltd., solid content 100% by mass)
Photoacid generator: Diphenyl [4- (Phenylthio) phenyl] Sulfonium hexafluoroantimonate 0.80 parts by mass (Product name: CPI (registered trademark) -101A, manufactured by San-Apro, solid content 50% by mass)

(Example 20)
A coating liquid having the composition shown below is applied onto the surface layer A of the laminated film X1 using a wire bar so that the release layer thickness after drying is 1.0 μm, and the film is dried at 120 ° C. for 15 seconds. A release film for manufacturing an ultra-thin ceramic green sheet was obtained.
Methyl ethyl ketone 45.00 parts by mass Toluene 45.00 parts by mass Binder (a): Hexamethoxymethylmelamine 9.50 parts by mass (Product names: N, N, N', N', N'', N''-hexakis ( Methyl) melamine, manufactured by Tokyo Chemical Industry Co., Ltd., 100% solid content)
Silsesquioxane component (b): PDMS, OH-containing silsesquioxane
0.10 parts by mass Acid catalyst (4-methylbenzoic acid) 0.40 parts by mass

(Example 21)
A release film for manufacturing an ultrathin ceramic green sheet was obtained in the same manner as in Example 1 except that the release layer was coated on the surface layer A of the laminated film X2 so that the film thickness was 0.8 μm. ..

(Example 22)
A release film for producing an ultrathin ceramic green sheet was obtained in the same manner as in Example 12 except that the release layer was coated on the surface layer A of the laminated film X2 so that the film thickness was 0.5 μm. ..

(Example 23)
A release film for producing an ultrathin ceramic green sheet was obtained in the same manner as in Example 12 except that the release layer was coated on the surface layer A of the laminated film X2 so that the film thickness was 0.2 μm. ..

(Comparative Example 1)
A release film for producing an ultrathin ceramic green sheet was obtained in the same manner as in Example 1 except that the coating liquid had the composition shown below.
Methyl ethyl ketone 45.00 parts by mass Isopropyl alcohol 45.00 parts by mass Binder component (a): 10-functional urethane acrylate 9.50 parts by mass (Product name: Shikou (registered trademark) UV-1700B, manufactured by Nippon Synthetic Chemical Co., Ltd., solid content 100 mass%)
0.10 parts by mass of polyether-modified PDMS (Product name: BYK UV-3510, manufactured by Big Chemie Japan, 100% by mass of solid content)
Radical initiator: 2-hirodoxy-1-{4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one 0.40 parts by mass (product name) : Omnirad127, manufactured by IGM Resins, solid content 100% by mass)

(Comparative Example 2)
A release film for producing an ultrathin ceramic green sheet was obtained by the same method as in Example 1 except that the coating liquid had the composition shown below.
Methyl ethyl ketone 45.00 parts by mass Isopropyl alcohol 45.00 parts by mass Binder component (a): Hexofunctional acrylate 9.50 parts by mass (Product name: A-DPH, manufactured by Shin Nakamura Chemical Industry Co., Ltd., solid content 100% by mass)
Acryloyl group-containing polyether-modified PDMS 0.10 parts by mass (Product name: BYK UV-3500, manufactured by Big Chemie Japan, solid content 100% by mass)
Radical initiator: 2-hirodoxy-1-{4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one 0.40 parts by mass (product name) : Omnirad127, manufactured by IGM Resins, solid content 100% by mass)

(Comparative Example 3)
A release film for producing an ultrathin ceramic green sheet was obtained by the same method as in Example 1 except that the coating liquid had the composition shown below.
Methyl ethyl ketone 44.80 parts by mass Toluene 44.80 parts by mass Binder component (a): Bifunctional alicyclic epoxy monomer 9.50 parts by mass (Product name: Celoxide (registered trademark) 2021P, manufactured by Daicel, solid content 100% by mass )
Epoxy-modified PDMS 0.10 parts by mass (Product name: X-22-173DX, manufactured by Shinetsu Silicone Co., Ltd., solid content 100% by mass)
Photoacid generator: Diphenyl [4- (Phenylthio) phenyl] Sulfonium hexafluoroantimonate 0.80 parts by mass (Product name: CPI (registered trademark) -101A, manufactured by San-Apro, solid content 50% by mass)

(Comparative Example 4)
A release film for producing an ultrathin ceramic green sheet was obtained by the same method as in Example 20 except that the coating liquid had the composition shown below.
Methyl ethyl ketone 45.00 parts by mass Toluene 45.00 parts by mass Binder (a): Hexamethoxymethylmelamine 9.50 parts by mass (Product names: N, N, N', N', N'', N''-hexakis ( Methyl) melamine, manufactured by Tokyo Chemical Industry Co., Ltd., 100% solid content)
Epoxy-modified PDMS 0.10 parts by mass (Product name: X-22-173DX, manufactured by Shinetsu Silicone Co., Ltd., solid content 100% by mass)
Acid catalyst (4-methylbenzoic acid) 0.40 parts by mass

(Comparative Example 5)
A release film for producing an ultrathin ceramic green sheet was obtained by the same method as in Example 1 except that the coating liquid had the composition shown below.
Methyl ethyl ketone 45.00 parts by mass Isopropyl alcohol 45.00 parts by mass Binder component (a): Hexofunctional acrylate 9.60 parts by mass (Product name: A-DPH, manufactured by Shin Nakamura Chemical Industry Co., Ltd., solid content 100% by mass)
Radical initiator: 2-hirodoxy-1-{4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one 0.40 parts by mass (product name) : Omnirad127, manufactured by IGM Resins, solid content 100% by mass)

(Comparative Example 6)
A release film for producing an ultrathin ceramic green sheet was obtained by the same method as in Example 1 except that the coating liquid had the composition shown below.
Methyl ethyl ketone 44.80 parts by mass Toluene 44.80 parts by mass Binder component (a): Bifunctional alicyclic epoxy monomer 9.60 parts by mass (Product name: Celoxide (registered trademark) 2021P, manufactured by Daicel, solid content 100% by mass )
Photoacid generator: Diphenyl [4- (Phenylthio) phenyl] Sulfonium hexafluoroantimonate 0.80 parts by mass (Product name: CPI (registered trademark) -101A, manufactured by San-Apro, solid content 50% by mass)

The release film for producing a ceramic green sheet of the present invention has a highly smooth release layer surface, a high hardness on the release layer surface, and excellent solvent resistance. Therefore, the release layer is not eroded during ceramic green sheet processing or electrode printing, and even when peeling an ultrathin ceramic green sheet with a thickness of 1 μm or less, the peeling force is low and uniform, resulting in defects such as pinholes. It is possible to mold a ceramic green sheet with less.

Claims (8)

A release film in which a release layer is provided on at least one side of a polyester film directly or via another layer.
The composition in which the release layer contains the binder component (a) and the silsesquioxane component (b) is cured, and the release layer is formed .
The binder component (a) is a radical curable substance,
The silsesquioxane component (b) has at least one reactive functional group selected from an acryloyl group, a methacryloyl group, an alkenyl group and a thiol group in the molecule.
Release film for manufacturing ceramic green sheets. The release film for producing a ceramic green sheet according to claim 1, wherein the content of the silsesquioxane component (b) with respect to the total solid content of the composition is 0.01% by mass to 60% by mass. The release film for producing a ceramic green sheet according to claim 1 or 2, wherein the silsesquioxane component (b) has a polyorganosiloxane group in the molecule. The release film for producing a ceramic green sheet according to claim 1, wherein the region surface average roughness (Sa) of the surface of the release layer is 7 nm or less. The release film for producing a ceramic green sheet according to claim 1, wherein the binder component (a) contains a compound having 6 or more functionalities . The polyester film has a surface layer A that does not substantially contain inorganic particles and a surface layer B on the opposite side that contains inorganic particles, and a release layer is provided on the surface layer A. The release film for producing a ceramic green sheet according to claim 1, wherein the inorganic particles contained in B are silica particles and / or calcium carbonate particles, and the total amount of the inorganic particles is contained in the surface layer B at 5000 to 15000 ppm. A method for manufacturing a ceramic green sheet having a thickness of 0.2 μm to 1.0 μm, wherein the ceramic green sheet is manufactured by using the release film for manufacturing the ceramic green sheet according to claim 1. A method for manufacturing a ceramic capacitor, which employs the method for manufacturing a ceramic green sheet according to claim 7.