JP2020114670A - Release film for manufacturing ceramic green sheet - Google Patents

Abstract

To provide a release film for manufacturing a ceramic green sheet, which can be peeled with a small uniform force even from an ultra-thin ceramic green sheet having a thickness of 1 μm or less, has no risk of generating defects such as pinholes, and suppresses transfer of a silicone component to the ceramic green sheet.SOLUTION: A release film for manufacturing a ceramic green sheet contains a biaxially oriented polyester film as a base material. The base material has, on at least one surface thereof, a surface layer A containing essentially no inorganic particles. A release layer is laminated directly or across another layer over a surface of the surface layer A on the at least one surface. The release layer is obtained by curing a composition including at least a release agent and a melamine-based compound. The release agent is a polyorganosiloxane comprising a carboxyl group. The content ratio of the melamine-based compound is at least 80 mass% based on the solid content of the composition forming the release layer.SELECTED DRAWING: None

Description

The present invention relates to a release film for producing a ceramic green sheet, and more specifically, it is possible to suppress the occurrence of process defects due to pinholes and uneven thickness during the production of an ultrathin layer ceramic green sheet, and the silicone component in the release layer. The present invention relates to an ultrathin layer release film for producing a ceramic green sheet, which is capable of suppressing the shift to the ceramic green sheet produced.

Conventionally, a release film having a polyester film as a base material and a release layer laminated thereon has been used for molding a ceramic green sheet such as a laminated ceramic capacitor or a ceramic substrate. In recent years, along with the miniaturization and large capacity of monolithic ceramic capacitors, the thickness of ceramic green sheets tends to be reduced. The ceramic green sheet is formed by coating a release film with a slurry containing a ceramic component such as barium titanate and a binder resin and drying the slurry. An electrode is printed on the molded ceramic green sheet and peeled off from the release film, and then the ceramic green sheet is laminated, pressed, fired, and coated with an external electrode to manufacture a laminated ceramic capacitor. When molding the ceramic green sheet on the surface of the release layer of the polyester film, there is a problem that 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 were. Therefore, various methods have been developed to realize a release layer surface having excellent flatness (see, for example, Patent Documents 1 and 2).

However, in recent years, the thickness of the ceramic green sheet has been further reduced, and a ceramic green sheet having a thickness of 1.0 μm or less, particularly 0.2 μm to 1.0 μm has been required. Since the strength of the ceramic green sheet decreases as the film becomes thinner, it is required not only to smooth the surface of the release layer but also to make the release force of the ceramic green sheet low and uniform when peeling it from the release film. Is coming. 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 addition, the silicone component in the release layer may easily transfer to the surface of the manufactured ceramic green sheet that is in contact with the release layer. The surface to which the silicone is transferred becomes slippery and the adhesiveness is reduced. When a ceramic green sheet is manufactured from a release film in which a silicone component is easily transferred, and a laminated ceramic product is manufactured using the ceramic green sheet, when pressure is applied to the laminated ceramic green sheets, In some cases, a deviation in the surface direction may occur between the layers of the laminated ceramic product. When such a deviation occurs, the positional accuracy of the electrodes and the like in the obtained laminated ceramic product deteriorates, and the product performance of the laminated ceramic product cannot be obtained. For this reason, there is a demand for a release film with less silicone component transfer to the ceramic green sheet.

Therefore, by using a polyorganosiloxane having at least one hydroxyl group in one molecule and a melamine-based resin that reacts with the hydroxyl group, a release film having a small amount of transferred silicone has been proposed (for example, See Patent Document 3). However, although the transfer amount is small, since the hydroxyl group of the polyorganosiloxane has a strong interaction with the melamine-based resin in the drying step, it is difficult for silicone to appear on the surface of the release layer, which is finally formed. In some cases, the peeling force was increased and the ceramic green sheet was damaged.

JP 2000-117899 A International Publication No. 2013/145864 JP, 2017-007227, A

The present invention has been made against the background of the problems of the related art. That is, since the surface of the release layer of the release film maintains high smoothness, and the peeling force is low and uniform, even an ultrathin layer product having a thickness of 1 μm or less can be formed into a ceramic green sheet with few defects, and the ceramic green sheet can be formed. An object of the present invention is to provide a release film for producing a ceramic green sheet in which migration of a silicone component to the is suppressed.

As a result of intensive studies to solve the above problems, the present inventors have used a polyester film and provided a release layer on at least one side, and the release layer contains a polyorganosiloxane containing at least a melamine compound and a carboxyl group. It has been found that a cured composition of the composition can suppress the migration of the silicone component to the ceramic green sheet and can provide a release film for producing a ceramic green sheet having excellent releasability.

That is, the present invention has the following configurations.
1. A biaxially oriented polyester film is used as a base material, and the base material has a surface layer A which does not substantially contain inorganic particles on at least one surface thereof, and at least one surface of the surface layer A is provided directly or with another layer. The release layer is laminated via, the release layer is obtained by curing a composition containing at least a release agent and a melamine compound, the release agent is a polyorganosiloxane containing a carboxyl group. And a release film for producing a ceramic green sheet, in which the content of the melamine compound is 80% by mass or more based on the solid content of the composition for forming the release layer.
2. The surface layer A having substantially no inorganic particles on one surface of the base material, the surface layer B on the opposite side of the base material from the surface layer A, and the surface layer B containing particles, At least a part of the particles are silica particles and/or calcium carbonate particles, and the total content of the particles with respect to the mass of the surface layer B is 5000 to 15000 ppm.
3. 3. The ceramic green sheet production according to the above 1 or 2, wherein the release surface of the release film has a surface area average roughness (Sa) of 7 nm or less and a maximum protrusion height (P) of 100 nm or less. Release film for.
4. A ceramic green sheet manufacturing method for molding a ceramic green sheet using the release film for manufacturing a ceramic green sheet according to any one of the first to third aspects, wherein the molded ceramic green sheet is 0.2 μm A method for manufacturing a ceramic green sheet having a thickness of 1.0 μm.
5. A method of manufacturing a ceramic capacitor, which employs the method of manufacturing a ceramic green sheet according to the fourth aspect.

The release film for producing a ceramic green sheet of the ultra-thin layer of the present invention has a smooth release layer surface, and has a pinhole and a thickness at the time of producing a ceramic green sheet as compared with a release film for producing a conventional ceramic green sheet. It is possible to suitably produce an ultra-thin ceramic green sheet having a thickness of 0.2 to 1.0 μm, which is capable of suppressing the occurrence of process defects due to unevenness and has less migration of the silicone component in the release layer to the ceramic green sheet. It is possible.

Hereinafter, the present invention will be described in detail.

The release film for producing an ultrathin layer ceramic green sheet of the present invention has a surface layer A containing substantially no inorganic particles on at least one surface of a biaxially oriented polyester film, and the surface layer A is directly attached to the surface layer A. Alternatively, it is preferable that a release layer formed by curing a composition containing at least a melamine compound and a polyorganosiloxane containing a carboxyl group is laminated via another layer.

(Polyester film)
The polyester constituting the biaxially oriented polyester film used as the substrate in the present invention is not particularly limited, and it is possible to use a film-molded polyester that is generally commonly used as a release film substrate. A crystalline linear saturated polyester composed of an aromatic dibasic acid component and a diol component is preferable, and examples thereof include polyethylene terephthalate, polyethylene-2,6-naphthalate, polybutylene terephthalate, polytrimethylene terephthalate, and these. A copolymer containing the resin component as a main component is more preferable, and a polyester film formed of polyethylene terephthalate is particularly preferable. Polyethylene terephthalate has a repeating unit of ethylene terephthalate of preferably 90 mol% or more, more preferably 95 mol% or more, and a small amount of other dicarboxylic acid component and diol component may be copolymerized, but from the viewpoint of cost. Those produced only from terephthalic acid and ethylene glycol are preferable. Further, known additives such as antioxidants, light stabilizers, ultraviolet absorbers and crystallization agents may be added within the range that does not impair the effects of the film of the present invention. The polyester film is preferably a biaxially oriented polyester film for reasons such as high bidirectional elastic modulus.

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, many breaks do not occur in the stretching step, which is preferable. On the contrary, when it is 0.70 dl/g or less, the cutting property when cutting to a predetermined product width is good, and dimensional defects do not occur, which is preferable. Further, it is preferable that the raw material pellets be sufficiently vacuum dried.

The method for producing the biaxially oriented polyester film in the present invention is not particularly limited, and a method generally used conventionally 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 longitudinally or transversely uniaxially stretched film in the transverse direction or the longitudinal direction, or a method of simultaneously biaxially stretching an unstretched film in the longitudinal and transverse directions. I can.

In the present invention, the stretching temperature at the time of stretching the polyester film is preferably at least the second-order transition point (Tg) of the polyester. It is preferable to stretch 1 to 8 times, particularly 2 to 6 times in each of the longitudinal and transverse directions.

The polyester film preferably has a thickness of 12 to 50 μm, more preferably 15 to 38 μm, and still more preferably 19 μm to 33 μm. When the thickness of the film is 12 μm or more, there is no fear of being deformed by heat during the film production, the release layer processing step, or the molding of the ceramic green sheet, which is preferable. On the other hand, when the thickness of the film is 50 μm or less, the amount of the film discarded after use is not extremely large, which is preferable in reducing the environmental load.

The biaxially oriented polyester film substrate may be a single layer or a multilayer having two or more layers, but it is preferable that at least one surface thereof has a surface layer A substantially containing no inorganic particles. 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 particles or the like on the opposite surface of the surface layer A substantially containing no inorganic particles. As for the laminated structure, when the layer on the side where the release layer is applied is the surface layer A, the layer on the opposite side is the surface layer B, and the core layer other than these is the layer C, the layer structure in the thickness direction is a release layer/ A layered structure of A/B or release layer/A/C/B may be used. Of course, the layer C may have a plurality of layer configurations. Further, the surface layer B may not contain particles. In that case, it is preferable to provide a coat layer containing particles and a binder on the surface layer B in order to impart a slip property for winding the film into a roll.

In the biaxially oriented polyester film substrate of the present invention, it is preferable that the surface layer A forming the surface on which the release layer is applied does not substantially contain inorganic particles. At this time, the area 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 the formation of the super thin ceramic green sheets to be laminated, which is preferable. It can be said that the smaller the area surface average roughness (Sa) of the surface layer A, the more preferable, but it may be 0.1 nm or more. Here, when an anchor coat layer described below is provided on the surface layer A, it is preferable that the coat layer does not substantially contain inorganic particles, and the area surface average roughness (Sa) after laminating the coat layer is within the above range. It is preferable to enter. In the present invention, “substantially free of inorganic particles” means a content of 50 ppm or less, preferably 10 ppm or less, most preferably the detection limit or less when the inorganic element is quantified by fluorescent X-ray analysis. To do. This is because contaminants derived from foreign substances and stains adhering to the raw material resin or the line or equipment in the manufacturing process of the film are peeled off and mixed into the film without actively adding inorganic particles to the film. This is because there are cases.

In the biaxially oriented polyester film substrate of the present invention, the surface layer B forming the surface opposite to the surface on which the release layer is applied may contain particles from the viewpoint of the slipperiness of the film and the ease of air escape. It is preferable to use silica particles and/or calcium carbonate particles. The content of particles contained in the surface layer B is preferably 5000 to 15000 ppm in total. At this time, the area average surface 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, when the film is wound into a roll, air can be uniformly released, and the winding shape is good and the flatness is good. , Which is suitable for manufacturing an ultra thin ceramic green sheet. Further, when the total amount of silica particles and/or calcium carbonate particles is 15000 ppm or less and Sa is 40 nm or less, aggregation of the lubricant is difficult to occur and coarse protrusions cannot be formed, so that the quality of the ceramic green sheet of an ultra-thin layer is stable. Is preferable.

As the particles contained in the surface layer B, inert inorganic particles and/or heat resistant organic particles other than silica and/or calcium carbonate can be used. It is more preferable to use silica particles and/or calcium carbonate particles from the viewpoint of transparency and cost, but examples of other 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. Further, 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 slipping of the lubricant. ..

The average particle diameter of the 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 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 kinds of particles made of different materials. Further, particles of the same kind but different in average particle diameter may be contained.

When the surface layer B does not contain particles, it is preferable that the surface layer B has a coat layer containing particles to provide slipperiness. The present coating layer is not particularly limited, but it is preferable to provide it by in-line coating which is applied during the formation of the polyester film. In the case where the surface layer B does not contain particles and the surface layer B has a coat layer containing particles, the surface of the coat layer has the same area surface roughness (Sa) of the surface layer B as described above. 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 pinhole reduction, it is preferable not to use recycled raw materials or the like in the surface layer A, which is the layer on the side where the release layer is provided, in order to prevent particles such as a lubricant from being mixed.

The thickness ratio of the surface layer A, which is the layer on the side where the release layer is provided, is preferably 20% or more and 50% or less of the total layer thickness of the base film. When it is 20% or more, the influence of the particles contained in the surface layer B or the like is not easily received from the inside of the film, and the area surface average roughness Sa easily satisfies the above range, which is preferable. When the thickness is 50% or less of the total thickness of the base film, the use ratio of the recycled raw material in the surface layer B can be increased, and the environmental load is reduced, which is preferable.

Further, from the viewpoint of economic efficiency, 50 to 90% by mass of film scraps and recycled materials of 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 surface layer B, the particle size, and the area surface average roughness (Sa) satisfy the above ranges.

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

(Structure of release layer)
The release layer in the present invention is preferably formed by curing a composition containing at least a melamine compound and a polyorganosiloxane containing a carboxyl group. Other components can be added in addition to the resin and the additive as long as the effects of the present invention are not impaired.

As the melamine-based compound used in the release layer in the present invention, general compounds can be used and are not particularly limited, but are obtained by condensing melamine and formaldehyde, and are obtained in one molecule by a triazine ring, and a methylol group and/or an alkoxy. It is preferable to have one or more methyl groups each. Specifically, a compound obtained by etherifying a methylolmelamine derivative obtained by condensing melamine and formaldehyde with a lower alcohol such as methyl alcohol, ethyl alcohol, isopropyl alcohol or butyl alcohol by dehydration condensation reaction is preferable. Examples of the methylolated melamine derivative include monomethylolmelamine, dimethylolmelamine, trimethylolmelamine, tetramethylolmelamine, pentamethylolmelamine, and hexamethylolmelamine. One kind may be used or two or more kinds 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 that occurs during peeling and to make the peeling force low and uniform. Therefore, it is preferable to use hexamethylolmelamine or hexaalkoxymethylmelamine having more cross-linking points in one molecule, but hexaalkoxymethylmelamine which is more excellent in reactivity is more preferable, and hexamethoxymethylmelamine is particularly preferable. At this time, the hexamethylolmelamine is one in which X is a methylol group (—CH ₂ —OH) in the following formula (a). The hexa-alkoxymethyl melamine, which was allowed to dehydration condensation reaction with an alcohol to methylol melamine derivative, X is (-CH 2 _{-OR, R} is an alkyl group having 1 to 4 carbon atoms) are those wherein. The hexamethoxymethylmelamine are those wherein X is _(-CH 2 -OMe).

The X's in (a) above may be the same or different. Further, the above Rs may be the same or different. Further, X may be (-H).

The weight average molecular weight of the melamine compound used in the release layer of the present invention is preferably 250 or more and 1000 or less. The weight average molecular weight is more preferably 250 or more and 900 or less, still more preferably 300 or more and 800 or less. When the weight average molecular weight is 1,000 or less, the crosslinking reaction easily proceeds, a film having a higher crosslinking density can be formed, and the peeling force can be reduced, which is preferable. When the weight average molecular weight is 250 or more, the crosslinking density becomes excessively high and the curl does not deteriorate, which is preferable. In addition, the weight average molecular weight in this specification is the value of standard polystyrene conversion measured by the gel permeation chromatography (GPC) method.

The weight average molecular weight of the melamine-based compound being 250 to 1000 means that the melamine-based compound used in the present invention contains a large amount of mononuclear bodies. Since the mononuclear body has more crosslinking points and is more reactive than the polynuclear body formed by condensing two or more melamine derivatives, it can be a release layer having a high crosslinking density and excellent releasability. The higher the content of the mononuclear body, the more preferable, and it is most preferable to use the melamine compound consisting of the mononuclear body alone.

The weight average molecular weight can also be represented by the weight average polymerization degree. The weight average degree of polymerization of the melamine-based compound used is preferably 2.0 or less, more preferably 1.5 or less, and the smaller the value, the more preferable it is. When the weight average degree of polymerization is 2.0 or less, the content of the mononuclear body contained in the melamine-based compound is increased, and the release layer having excellent reactivity and excellent releasability can be obtained, which is preferable. The weight average degree of polymerization in the present specification is a value calculated based on the weight average molecular weight obtained by gel permeation chromatography in terms of standard polystyrene.

The melamine compound may contain an imino group (—NH ₂ —) or a polynuclear body in the course of its synthesis. Even if these melamine derivatives are mixed, if the weight average polymerization degree of the melamine-based compound is within the above range, the reactivity is excellent and they can be suitably used.

The release layer in the present invention preferably contains a melamine compound in an amount of 80% by mass or more and 99.9% by mass or less, and more preferably 90% by mass or more, based on the solid content of the composition for forming a releasing layer. It is 99.9 mass% or less, and more preferably 95 mass% or more and 99.9 mass% or less. By containing 80% by mass or more of the melamine-based compound, the release layer can obtain a high crosslinking density due to self-crosslinking of the melamine-based compound and can suppress the deformation of the release layer at the time of peeling. At this time, the solid content of the release layer-forming composition means that the solvent and the acid catalyst are evaporated in a considerable amount in the drying process, so that the solid content of the melamine-based compound and the solid content of the release agent are substantially the same. You can regard it as the value that you did.

In the release layer of the present invention, it is preferable to add an acid catalyst in order to accelerate the crosslinking reaction of the melamine-based compound, and it is possible to add the acid catalyst to the composition for forming the release layer and apply it to cure it. preferable. The acid catalyst used is not particularly limited, and an existing acid catalyst can be used, but it is preferable to use a sulfonic acid catalyst.

As the sulfonic acid catalyst, for example, p-toluene sulfonic acid, xylene sulfonic acid, cumene sulfonic acid, dodecylbenzene sulfonic acid, dinonylnaphthalene sulfonic acid, trifluoromethane sulfonic acid and the like can be preferably used. From the viewpoint of properties, p-toluenesulfonic acid can be particularly preferably used.

The sulfonic acid catalyst used in the present invention may be a commercially available one. Examples of commercially available products include a dryer (registered trademark) 900 (p-toluenesulfonic acid, manufactured by Hitachi Chemical Co., Ltd.), NACURE (registered trademark) DNNDSA series (dinonylnaphthalenedisulfonic acid, manufactured by Kusumoto Kasei Co., Ltd.), and DNNSA series ( Examples include dinonylnaphthalene (mono) sulfonic acid, manufactured by Kusumoto Kasei Co., Ltd., DDBSA series (dodecylbenzene sulfonic acid, manufactured by Kusumoto Kasei Co., Ltd.), p-TSA series (p-toluene sulfonic acid, manufactured by Kusumoto Kasei Co., Ltd.) and the like. To be

Since the sulfonic acid-based catalyst has higher acidity and higher reactivity than other acid catalysts such as carboxylic acid-based catalysts, the release layer can be processed at a lower temperature. Therefore, the flatness of the film and the deterioration of the winding appearance due to heat during processing can be suppressed, which is preferable.

The addition amount of the acid catalyst is preferably 0.1 to 10 mass% with respect to the melamine-based compound contained in the release layer. More preferably, it is 0.5 to 8 mass %. More preferably, it is 0.5 to 5 mass %. When the content is 0.1% by mass or more, the curing reaction easily proceeds, which is preferable. On the other hand, when the content is 10% by mass or less, there is no possibility that the acid catalyst will migrate to the ceramic green sheet to be molded, and there is no risk of adverse effects, which is preferable.

As the release agent used in the release layer of the present invention (additive for improving the release property of the release layer), it is preferable to use a polyorganosiloxane containing a carboxyl group from the viewpoints of both release property and suppression of transfer amount. preferable. Among the polyorganosiloxane structures, a polyorganosiloxane containing a carboxyl group having a polydimethylsiloxane structure (abbreviation: PDMS) can be preferably used.

Since the polyorganosiloxane that is the release agent contains a carboxyl group, the release agent does not show a strong interaction with the melamine-based compound in the drying step, is easily aligned on the surface of the release layer, and has good release properties. can get. Therefore, it is preferable to use a polyorganosiloxane containing a carboxyl group because the releasability can be satisfied even if the amount of the release agent added is small. Further, it is preferable that the polyorganosiloxane, which is a release agent, contains a carboxyl group, since it shows weak interaction with the melamine compound, and thus it is difficult to migrate to the ceramic green sheet.

The carboxyl group may be introduced at one end of the polyorganosiloxane, or may be at both ends or a side chain, but the one introduced at one end is preferable because of excellent releasability. Further, the introduction position may be one or plural.

The carboxyl group-modified polyorganosiloxane may be one in which a carboxyl group is directly bonded to the silicon atom of the polyorganosiloxane, or one in which a carboxyl group is bonded to the polyorganosiloxane through an alkyl group or an aryl group. It may be. However, those in which a carboxyl group is bonded to a polyorganosiloxane through an organic group having a repeating structure such as polyether, polyester, and polyurethane are not very preferable.

The functional group to be introduced into the polyorganosiloxane as the release agent may have another functional group other than the carboxyl group in one molecule, but the carboxyl group alone is preferable. When a functional group other than the carboxyl group is contained, the intermolecular interaction with the melamine-based compound increases more than necessary and the orientation on the surface of the release layer becomes difficult, which is not preferable.

When a polyorganosiloxane modified with a hydroxyl group that has a strong interaction with a melamine-based compound reacts rapidly with the melamine-based compound in the drying process, it is difficult to be oriented on the surface of the release layer and the releasability is difficult to develop. There is. Therefore, it is necessary to increase the addition amount in order to have sufficient release properties, but in that case the elastic modulus of the release layer decreases and deformation of the release layer during peeling tends to occur, and the peeling force may increase. is there. In addition, when the amount of polyorganosiloxane added is increased, the amount transferred to the ceramic green sheet tends to increase, which is not preferable.

The polyorganosiloxane containing a carboxyl group used in the present invention preferably has a molecular weight of 40,000 or less. It is more preferably 30,000 or less, more preferably 10,000 or less, and the smaller the molecular weight, the more suitably used. When the molecular weight is 40,000 or less, the polyorganosiloxane containing a carboxyl group is easily segregated on the surface of the release layer, and the releasability is good, which is preferable.

As described above, the carboxyl group-containing polyorganosiloxane is more preferably a carboxyl group-containing polydimethylsiloxane. Examples of the polydimethylsiloxane containing a carboxyl group include X22-3701E (side chain carboxyl-modified polydimethylsiloxane, manufactured by Shin-Etsu Chemical Co., Ltd.), X22-3710 (single-terminal carboxyl-modified polydimethylsiloxane, manufactured by Shin-Etsu Chemical Co., Ltd.), X22. -162C (both-terminal carboxyl-modified polydimethylsiloxane, manufactured by Shin-Etsu Chemical Co., Ltd.), BY16-750 (both-terminal carboxyl-modified polydimethylsiloxane, manufactured by Toray Dow Corning), BY16-880 (side-chain carboxyl-modified polydimethylsiloxane, Toray) Dow Corning), Magnasoft 800L (carboxyl-modified polydimethylsiloxane at both ends, manufactured by Momentive), and the like can be used.

The polydimethylsiloxane containing a carboxyl group in the present invention may be an acrylic resin having a side chain of polydimethylsiloxane introduced into an acrylic main chain containing a carboxyl group. As the acrylic resin in which polydimethylsiloxane is introduced into the side chain of the acrylic main chain containing a carboxyl group, Cymac (registered trademark) US-350, US-352, US-380 (above, manufactured by Toagosei Co., Ltd.), etc. Can be used. Further, it may be an acrylic resin in which polydimethylsiloxane is introduced into a side chain in an acrylic main chain containing a carboxyl group and a hydroxyl group in one molecule. As an acrylic resin in which polydimethylsiloxane is introduced into a side chain in an acrylic main chain containing a carboxyl group and a hydroxyl group in one molecule, Cymac (registered trademark) US-450, US-480 (above, manufactured by Toagosei Co., Ltd. ) Etc. can be used

The release layer in the present invention preferably contains a release agent in an amount of 0.1% by mass or more and 20% by mass or less based on the solid content of the composition for forming a release layer. It is more preferably 0.1% by mass or more and 10% by mass or less, and further preferably 0.1% by mass or more and 5% by mass or less. When the content is 0.1% by mass or more, the releasability is improved and the releasability of the ceramic green sheet is improved, which is preferable. On the other hand, when the content is 20% by mass or less, the elastic modulus of the release layer does not decrease excessively, and it is possible to suppress deformation of the release layer at the time of peeling the ceramic green sheet and to suppress an increase in release force, which is preferable. Further, it is preferably 20% by mass or less from the viewpoint that the transfer amount of the release agent does not become too high. At this time, the solid content of the composition for forming the release layer, since the solvent and the acid catalyst will be evaporated a considerable portion in the drying process, substantially the total value of the solid content of the melamine compound and the release agent and You can consider it.

The release layer according to the present invention may contain particles having a particle diameter of 1 μm or less, but it is preferable not to contain particles that form protrusions such as particles from the viewpoint of pinholes.

In the release layer of the present invention, additives such as an adhesion improver and an antistatic agent may be added as long as the effects of the present invention are 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, atmospheric pressure plasma treatment, etc. on the surface of the polyester film before providing the release coating layer.

(Characteristic of 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 range where the weight of the release coating layer after curing is 0.01 to 2.0 μm. Well, more preferably 0.01 to 1.0 μm, further preferably 0.01 to 0.8 μm, further preferably 0.02 to 0.5 μm, and 0.02 to 0. Most preferably, it is 3 μm. When the thickness of the release layer is 0.01 μm or more, peeling performance is obtained, which is preferable. Further, when it is 2.0 μm or less, the curing time can be shortened, the flatness of the release film can be maintained, and the uneven thickness of the ceramic green sheet can be suppressed, which is preferable.

The release layer surface of the release film of the present invention is preferably flat so as not to cause defects in the ceramic green sheet applied/molded thereon, and the area surface average roughness (Sa) is 7 nm or less and maximum. The protrusion height (P) is preferably 100 nm or less. Further, it is more preferable that the average surface roughness of the region is 5 nm or less and the maximum protrusion height is 80 nm or less. When the area surface roughness is 7 nm or less and the maximum protrusion height is 100 nm or less, defects such as pinholes do not occur when forming the ceramic green sheet, and the yield is good, which is preferable. It can be said that the smaller the area surface average roughness (Sa), the more preferable, 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.

Since the release film of the present invention uses a highly flattened base film, even if the release layer has a thickness of less than 0.5 μm, and even less than 0.2 μm, the release layer surface is Can be smooth. Therefore, it is possible to suppress the occurrence of curl even in a release layer using a highly reactive melamine compound. In addition, the amount of solvent and resin used can be reduced, which is environmentally friendly and can inexpensively produce a release film for forming an ultrathin ceramic green sheet.

Surface free energy of the release layer surface of the release layer film of the present invention (gamma] s) is preferably 18 mJ / ^{m 2} or more 35 mJ / ^{m 2} or less. More preferably, 23 mJ / ^{m 2} or more 35 mJ / ^{m 2} or less, further preferably 23 mJ / ^{m 2} or more 30 mJ / ^{m 2} or less. When it is 18 mJ/m ² or more, cissing is less likely to occur when the ceramic slurry is applied, and uniform coating is preferable. Further, when it is 35 mJ/m ² or less, there is no fear that the releasability of the ceramic green sheet is deteriorated, which is preferable. When the content is within the above range, it is possible to provide a release film which is free from cissing during coating and has excellent releasability.

The release film of the present invention preferably has a peeling force of 0.5 mN/mm ² or more and 2.5 mN/mm ² or less when peeling the ceramic green sheet. More preferably, it is 0.8 mN/mm ² or more and 2.0 mN/mm ² or less. When the peeling force is 0.5 mN/mm ² or more, the peeling force is not too light, and there is no fear that the ceramic green sheet will float during transportation, which is preferable. When the peeling force is 2.5 mN/mm ² or less, the ceramic green sheet is not damaged at the time of peeling, which is preferable.

The release film of the present invention preferably has a curl of 3 mm or less after heating at 100° C. for 15 minutes without applying tension, and more preferably 1 mm or less. Of course, it is also preferable not to curl at all. When the thickness is 3 mm or less, curling is small when printing a ceramic green sheet to print an electrode, and printing accuracy can be improved, which is preferable.

In the release film of the present invention, the smaller the amount of silicone component transferred to the ceramic green sheet after peeling, the more preferable. The migration amount of the silicone component was determined by applying PVB, which is one of the binder components contained in the ceramic green sheet, on the release film in a pseudo manner, molding it, and measuring the Si intensity of the release layer before and after peeling with fluorescent X-rays. It can be evaluated by measuring. 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 (before)-Si (after) was taken as the transfer amount. The transfer amount at this time is preferably 0.10 kcps or less, and more preferably 0.04 kcps or less. When the transfer amount is 0.10 kcps or less, the occurrence of process defects such as stacking deviation and defective adhesion is suppressed, and there is no fear of reducing the reliability of the ceramic capacitor, which is preferable.

In the present invention, the method for forming the release layer is not particularly limited, and a coating liquid in which a release resin is dissolved or dispersed is spread on one surface of the polyester film of the substrate by coating or the like, and a solvent, etc. After removing by drying, a method of heating and drying and heat curing is used. At this time, the drying temperature during solvent drying and heat curing is preferably 100° C. or higher and 180° C. or lower, more preferably 100° C. or higher and 160° C. or lower, and 100° C. or higher and 140° C. or lower. Is most preferred. 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 thickness of the ceramic green sheet is less likely to be uneven, which is preferable. When the temperature is 140° C. or less, 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 lower than 100°C, the curing reaction of melamine does not proceed sufficiently and the elastic modulus of the release layer decreases, which is not preferable.

In the present invention, the surface tension of the coating liquid when applying the release layer is not particularly limited, but is preferably 30 mN/m or less. By adjusting the surface tension as described above, the wettability 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 of addition thereof is preferably about 10 to 80% by mass with respect to the entire coating liquid.

As the coating method of the coating liquid, any known coating method can be applied, 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, an air knife. A conventionally known method such as a coating method can be used.

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

The release film for producing a ceramic green sheet of the present invention is used for producing such a laminated ceramic capacitor. For example, it is manufactured as follows. First, using the release film of the present invention as a carrier film, a ceramic slurry for forming a ceramic body is applied and dried. An extremely thin ceramic green sheet having a thickness of 0.2 to 1.0 μm is required. 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. By doing so, a mother laminate is obtained. The mother laminated body is divided into a plurality of pieces to produce a raw ceramic body. A ceramic body is obtained by firing a raw ceramic body. After that, the first and second external electrodes are formed to complete the monolithic ceramic capacitor.

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 by the following methods.

(Surface roughness)
It is a value measured under the following conditions using a non-contact surface shape measuring system (VertScan R550H-M100). As the area surface average roughness (Sa), the average value of 5 measurements was adopted, and the maximum projection height (P) was measured 7 times, and the maximum value of 5 times excluding the maximum value and the minimum value was used.
(Measurement condition)
・Measurement mode: WAVE mode ・Objective lens: 10 times ・0.5×Tube lens ・Measurement area: 936 μm×702 μm
(Analysis conditions)
・Face correction: Quaternary correction ・Interpolation process: Complete interpolation

(Surface free energy)
Water (droplet amount 1.8 μL) was applied to the release surface of the release film using a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd.: fully automatic contact angle meter DM-701) under the conditions of 25° C. and 50% RH. , And liquid droplets of diiodomethane (liquid proper amount 0.9 μL) and ethylene glycol (liquid proper amount 0.9 μL) were prepared and the contact angles thereof were measured. As the contact angle, the contact angle 10 seconds after each liquid was dropped on the release film was adopted. Obtained by the above method, water, diiodomethane, contact angle data of ethylene glycol was calculated from the "Kitasaki-Hata" theory to obtain the dispersion component γsd of the surface free energy of the release film, the polar component γsp, and the hydrogen bonding component γsh, The surface free energy γs was the sum of the components. For this calculation, calculation software in this contact angle meter software (FAMAS) was used.

(Evaluation of coatability of ceramic slurry)
The composition consisting 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 (Fujititanium Co., Ltd. HPBT-1) 35.0 parts by mass Polyvinyl butyral (Sekisui Chemical Co., Ltd. S-REC BM-S)
3.5 parts by mass DOP (dioctyl phthalate) 1.8 parts by mass The resulting release film sample was coated on the release surface with an applicator so that the dried slurry would have a thickness of 1 μm, and at 90° C. 1 After minute drying, the coatability was evaluated according to the following criteria.
○: There is no cissing and the entire surface can be coated.
Δ: There is some cissing at the coating end, but coating is almost complete.
X: There is a lot of cissing, and coating cannot be performed

(Pinhole evaluation of ceramic green sheet)
A ceramic green sheet having a thickness of 1 μm was formed on the release surface of the release film in the same manner as in the coating property evaluation of the ceramic slurry. Then, the release film was peeled off from the molded release film with the ceramic green sheet to obtain a ceramic green sheet. In the center area of the obtained ceramic green sheet in the width direction of the film, light was applied from the surface opposite to the ceramic slurry application surface within a range of 25 cm ² , and the occurrence of pinholes that were seen through the light was observed. It was visually judged.
○: Pinholes were not generated △: Pinholes were not generated ×: Many pinholes were generated

(Peelability evaluation of ceramic green sheets)
The composition consisting 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 (Fujititanium Co., Ltd. HPBT-1) 64.8 parts by mass Polyvinyl butyral (Sekisui Chemical Co., Ltd. S-REC BM-S)
6.5 parts by mass DOP (dioctyl phthalate) 3.3 parts by mass The resulting release film sample was coated on the release surface with an applicator so that the dried slurry had a thickness of 10 μm, and at 90° C. After drying for 1 minute, a ceramic green sheet was molded on a release film. The obtained release film with a ceramic green sheet was destaticized using a static eliminator (Keyence Corp., SJ-F020), and then delaminated at a width of 30 mm at a peeling angle of 90 degrees and a peeling speed of 10 m/min. The stress applied during peeling was measured and used as the peeling force. Judgment was made based on the obtained peeling force values according to the following criteria.
○: 0.5mN / mm ² or more, 2.0 mN / mm ² or less △: greater than ^{2.0mN / mm 2, 2.5mN / mm} 2 or less ×: larger than 2.5 mN / mm ²

(Evaluation of transfer amount of silicone component in release layer)
The following composition of materials was stirred and mixed to obtain a polyvinyl butyral (PVB) solution.
Toluene 45.0 parts by mass Ethanol 45.0 parts by mass Polyvinyl butyral (Sekisui Chemical Co., Ltd. S-REC BM-S)
10.0 parts by mass The release film sample thus obtained is coated on the release surface with an applicator so that the polyvinyl butyral (PVB) sheet after drying is 10 μm, dried at 90° C. for 1 minute, and then released. The film was peeled off, and the surface of the peeled PVB sheet that was in contact with the release film (release layer) and the release layer of the release film before coating the PVB sheet were treated with a fluorescent X-ray device (ZSX manufactured by Rigaku). The Si intensity was measured with a Primus 2) to quantify the transferred amount of the silicone component. The measurement conditions of the fluorescent X-ray apparatus were as follows.
Analysis line: Si-KA, Target: Rh 4.0 kW
Tube voltage: 50kV, tube current: 60mA
Filter: OUT, Attenuator: 1/1, Slit: S4, Spectroscopic crystal: PET
Detector: PC, PHA condition: 100 (lower limit)-300 (upper limit)
Measurement diameter: 30 mm, atmosphere: vacuum The transfer amount of the silicone component is Si (before) the Si strength of the release surface of the release film before coating the PVB sheet, and release after coating/peeling the PVB sheet. The Si strength of the release surface of the film was defined as Si (rear), and the value obtained by subtracting Si (rear) from Si (front) was defined as the transfer amount of the silicone component. Judgment was made according to the following criteria from the obtained numerical value of the amount of transferred silicone component.
◯: 0.04 kcps or less Δ: greater than 0.04 kcps and less than 0.10 kcps
×: 0.10 kcps or more

(Curl evaluation of release film)
The release film sample was cut into a size of 10 cm×10 cm, and heat-treated at 100° C. for 15 minutes in a hot air oven so that tension was not applied to the release film. Then, after taking out from an oven and cooling to room temperature, the mold release film sample was put on the glass plate so that the mold release surface faced up, and the heights of the portions floating from the glass plate at the four corners were measured. The average value of the floating amounts at the four corners measured at this time was defined as the curl amount. The curl property was evaluated according to the following criteria. ⊚: The curl is 1 mm or less, and almost no curl is observed. ◯: The curl is larger than 1 mm and 3 mm or less, and a little curl is observed.
Δ: The curl was larger than 3 mm and 10 mm or less, and the curl was observed.
C: The curl was greater than 10 mm.

(Measurement method of weight average degree of polymerization)
Analytical conditions 16 mg of a sample was weighed and dissolved in 8 ml of chloroform. After filtration through a 0.2 μm membrane filter, gel permeation chromatography (GPC) analysis of the obtained sample solution was carried out under the following conditions.

Equipment: TOSOH HLC-8320GPC
Column: K-G+K-802 (Exclusion limit molecular weight 5×10 ³ )+ K-801 (Exclusion limit molecular weight 1.5×10 ³ )(Shodex),
Solvent: 100% chloroform
Flow rate: 1.0 ml/min
Concentration: 0.2%
Injection volume: 50 μL Temperature: 40°C
Detector: RI
The weight average molecular weight was calculated in terms of polystyrene, and the weight average polymerization degree was calculated based on the calculated value. As the polystyrene, PStQuick C (TOSOH) of PStQuick series was used. Among polystyrenes added to PStQuick C (TOSOH), polystyrenes Mw2110000, 427000, and 37900 that greatly exceeded the exclusion limit molecular weight of the column were excluded from the calibration curve preparation.

(Preparation of polyethylene terephthalate pellets (PET (I)))
As the esterification reaction device, a continuous esterification reaction device consisting of a three-stage complete mixing tank having a stirrer, a partial condenser, a raw material charging port and a product outlet was used. TPA (terephthalic acid) was 2 tons/hour, EG (ethylene glycol) was 2 mol per 1 mol of TPA, and antimony trioxide was produced in an amount such that Sb atom was 160 ppm with respect to the produced PET. It was continuously supplied to the first esterification reaction can of the oxidization reaction apparatus, and was allowed to react at an atmospheric pressure and an average residence time of 4 hours at 255°C. Then, 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 is distilled off from the first esterification reaction can in the second esterification reaction can. 8 mass% of EG is supplied to the produced PET, and further, an EG solution containing magnesium acetate tetrahydrate in an amount of 65 ppm of Mg atoms to the produced PET, and 40 ppm of P atoms to the produced PET. An EG solution containing an amount of TMPA (trimethyl phosphate) was added and reacted at 260° C. under atmospheric pressure for an average residence time of 1 hour. Then, the reaction product of the second esterification reaction can is continuously taken out of the system and supplied to the third esterification reaction can, and 39 MPa (400 kg/cm ² ) 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, which has been subjected to a dispersion treatment with an average number of treatments of 5 passes under pressure of 1% by mass, and an ammonium salt of polyacrylic acid per 1% by mass of calcium carbonate. 0.4% by mass of synthetic calcium carbonate having a diameter of 0.6 μm was added as 10% EG slurry, respectively, and reacted at atmospheric pressure at an average residence time of 0.5 hours at 260° C. The esterification reaction product produced in the third esterification reaction vessel was continuously supplied to a three-stage continuous polycondensation reactor to perform polycondensation, and a 95% cut diameter of stainless steel fiber having a diameter of 20 μm was sintered. After filtering with a filter, ultrafiltration was performed and extruded into water, and after cooling, 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 chips was 0.6% by mass.

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

(Preparation of polyethylene terephthalate pellets (PET(III)))
Except that the type and content of PET (I) particles are changed to 0.75% by mass of synthetic calcium carbonate having an average particle size of 0.9 μm in which 1% by mass of ammonium salt of polyacrylic acid is adhered per calcium carbonate. A PET chip was obtained in the same manner as PET (I) (hereinafter abbreviated as PET (III)). The lubricant content in the PET chips was 0.75% by mass.

(Production of laminated film X1)
After drying these PET chips, they were melted at 285° C., melted at 290° C. by a separate melt extruder, and a filter made by sintering stainless steel fibers having a 95% cut diameter of 15 μm and a 95% cut diameter Two stages of filtration with a filter made by sintering stainless steel particles of 15 μm are performed, and they are merged in a feed block to make PET (I) a surface layer B (releasing surface side layer) and PET (II) a surface. Layer A (releasing surface side layer) is laminated, and extruded (casting) into a sheet at a speed of 45 m/min, and electrostatically adhered and cooled on a casting drum at 30° C. by an electrostatic adhesion method. An unstretched polyethylene terephthalate sheet having an intrinsic viscosity of 0.59 dl/g was obtained. The layer ratio was adjusted so that PET(I)/(II)=60% by mass/40% by mass was calculated by calculating the discharge amount of each extruder. Next, this unstretched sheet was heated by an infrared heater and then stretched 3.5 times in the machine direction at a roll temperature of 80° C. due to the speed difference between the rolls. Then, it was introduced into a tenter and stretched 4.2 times in the transverse direction at 140°C. Then, heat treatment was performed at 210° C. in the heat setting zone. Then, a relaxation treatment of 2.3% was performed in the transverse direction at 170° C. to obtain a biaxially stretched polyethylene terephthalate film X1 having a thickness of 31 μm. The Sa of the surface layer A of the obtained film X1 was 2 nm, and the Sa of the surface layer B was 28 nm.

(Production of laminated film X2)
The thickness was adjusted by changing the speed during casting without changing the layer structure and the stretching conditions similar to those of the laminated film X1 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 3 nm, and the Sa of the surface layer B was 29 nm.

(Laminated film X3)
As the laminated film X3, A4100 (Cosmoshine (registered trademark), manufactured by Toyobo Co., Ltd.) having a thickness of 25 μm was used. A4100 has a structure in which particles are not substantially contained in the film and a coating layer containing particles is provided by in-line coating on the surface layer B side. The Sa of the surface layer A of the laminated film X3 was 1 nm, and the Sa of the surface layer B was 2 nm.

(Laminated film X4)
As the laminated film X4, 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 particles are contained in the film. The Sa of the surface layer A of the laminated film X4 was 24 nm, and the Sa of the surface layer B was 24 nm.

(Example 1)
A coating solution having the following composition is applied on the surface layer A of the laminated film X1 by using reverse gravure so that the release layer thickness after drying becomes 50 nm, and dried at 140° C. for 15 seconds to obtain an ultrathin film. A release film for producing a multilayer ceramic green sheet was obtained. When a ceramic slurry was applied to the obtained release film and the coating properties, releasability, transfer amount of silicone components, pinholes, curls, etc. were evaluated, good evaluation results were obtained.
Methyl ethyl ketone 49.45 parts by mass Toluene 49.45 parts by mass Melamine compound 0.95 parts by mass (Full ether type methylated melamine, solid content 100%, Sanwa Chemical Co., Ltd., trade name MW-30M, weight average degree of polymerization 1 .3)
Release agent 0.05 part by mass (polydimethylsiloxane modified with carboxyl carboxyl at one end, X22-3710, solid content 100%, manufactured by Shin-Etsu Chemical Co., Ltd., with an alkyl group interposed between the dimethylsiloxane and the carboxyl group)
Acid catalyst 0.10 parts by mass (p-toluenesulfonic acid, manufactured by Hitachi Chemical Co., Ltd., trade name Dryer (registered trademark) 900, solid content 50%)

(Example 2)
The content of the full-ether-type methylated melamine in the coating liquid of Example 1 was set to 0.98 parts by mass, and the amount of the release agent (X22-3710) added was changed to 0.02 parts by mass, except that the coating liquid was used. In the same manner as in Example 1, a release film for producing an ultrathin layer ceramic green sheet was obtained.

(Example 3)
The content of the full-ether-type methylated melamine in the coating liquid of Example 1 was set to 0.9 parts by mass, and the amount of the release agent (X22-3710) added was changed to 0.1 parts by mass except that the coating liquid was used. In the same manner as in Example 1, a release film for producing an ultrathin layer ceramic green sheet was obtained.

(Example 4)
Other than using the coating liquid in which the content of the full-ether type methylated melamine in the coating liquid of Example 1 was 0.8 parts by mass and the amount of the release agent (X22-3710) added was changed to 0.2 parts by mass. In the same manner as in Example 1, a release film for producing an ultrathin layer ceramic green sheet was obtained.

(Examples 5 to 8)
A release film for producing an ultrathin layer ceramic green sheet was obtained in the same manner as in Example 1 except that the thickness of the release layer in Example 1 was changed to the thickness shown in Table 1.

(Example 9)
A release film for producing an ultrathin layer ceramic green sheet was obtained in the same manner as in Example 1 except that the substrate film of Example 1 was changed to the laminated film X2 having a film thickness of 25 μm.

(Example 10)
A release film for producing an ultrathin layer ceramic green sheet was obtained in the same manner as in Example 1 except that the laminated film of Example 1 was changed to the laminated film X3.

(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 drying conditions in Example 1 were changed to 90° C. for 15 seconds.

(Example 12)
A release film for producing an ultrathin layer ceramic green sheet was obtained in the same manner as in Example 1 except that the drying conditions in Example 1 were changed to 110° C. for 15 seconds.

(Example 13)
Ultra thin ceramic green sheet was prepared in the same manner as in Example 1 except that the release agent of Example 1 was changed to X22-3701E (side chain type carboxyl-modified polydimethylsiloxane, manufactured by Shin-Etsu Chemical Co., Ltd.). A release film for production was obtained.

(Example 14)
Ultra thin ceramic green sheet was prepared in the same manner as in Example 1 except that the release agent of Example 1 was changed to X22-162C (both terminal type carboxyl-modified polydimethylsiloxane, manufactured by Shin-Etsu Chemical Co., Ltd.). A release film for production was obtained.

(Example 15)
Example 1 except that a coating liquid in which the full ether type methylated melamine of Example 1 was changed to MW-30 (full ether type methylated melamine, manufactured by Sanwa Chemical Co., Ltd., weight average polymerization degree: 1.5) was used. Similarly, a release film for producing an ultrathin layer ceramic green sheet was obtained.

(Example 16)
Example 1 except that a coating solution in which the full-ether type methylated melamine of Example 1 was changed to MS-21 (full-ether type methylated melamine, manufactured by Sanwa Chemical Co., Ltd., weight average degree of polymerization 1.8) was used. Similarly, a release film for producing an ultrathin layer ceramic green sheet was obtained.

(Example 17)
Except that the coating liquid in which the full-ether type methylated melamine of Example 1 was changed to MX-730 (imino type methylated melamine, solid content 80%, Sanwa Chemical Co., Ltd., weight average polymerization degree 2.4) was used. A release film for producing an ultrathin layer ceramic green sheet was obtained in the same manner as in Example 1.

(Comparative Example 1)
A release film for producing an ultrathin layer ceramic sheet was obtained in the same manner as in Example 1 except that a coating solution containing no release agent was used in the coating layer of Example 1. Since the release agent was not contained, the peeling force became heavy.

(Comparative example 2)
A release film for producing an ultrathin layer ceramic sheet was obtained in the same manner as in Example 1 except that the laminated film X4 (E5101-25 μm, manufactured by Toyobo) was used instead of the laminated film X1. E5101 contained particles in both the surface layer A and the surface layer B, and the Sa of both the surface layer A and the surface layer B was 24 nm. Due to the large surface roughness, pinholes were generated in the ceramic green sheet.

(Comparative example 3)
A release film for producing an ultrathin layer ceramic sheet was obtained in the same manner as in Example 1 except that the coating liquid had the following composition. In Comparative Example 3 in which a large amount of the release agent was added and the melamine compound was only 70% by mass of the release layer, the amount of PDMS transferred to the ceramic green sheet was large.
Methyl ethyl ketone 49.45 parts by mass Toluene 49.45 parts by mass Melamine compound 0.70 parts by mass (Full ether type methylated melamine, solid content 100%, Sanwa Chemical Co., Ltd., trade name MW-30M, weight average degree of polymerization 1 .3)
Release agent 0.30 parts by weight (carboxyl-modified polydimethylsiloxane at one end, X22-3710, solid content 100%, manufactured by Shin-Etsu Chemical Co., Ltd.)
Acid catalyst 0.10 parts by mass (p-toluenesulfonic acid, manufactured by Hitachi Chemical Co., Ltd., trade name Dryer (registered trademark) 900, solid content 50%)

(Comparative Example 4)
A release film for producing an ultrathin layer ceramic sheet was obtained in the same manner as in Example 1 except that the coating liquid had the following composition. BYK-370 is a polydimethylsiloxane having two kinds of functional groups (ester group and hydroxyl group) in one molecule. Although the amount of PDMS transferred was low and good, the peeling force was heavy probably because PDMS was not exposed on the surface because the interaction between the hydroxyl group and the melamine compound was strong.
Methyl ethyl ketone 48.38 parts by mass Toluene 48.37 parts by mass Melamine 0.95 parts by mass (Full ether type methylated melamine, solid content 100%, Sanwa Chemical Co., Ltd., trade name MW-30M, weight average degree of polymerization 1.3. )
Release agent 0.20 parts by mass (polyester-modified OH group-containing polydimethylsiloxane, BYK-370, solid content 25%, manufactured by BYK Japan KK) Acid catalyst 0.10 parts by mass (p-toluenesulfonic acid, Hitachi Chemical Co., Ltd.) Made, product name Dryer (registered trademark) 900, solid content 50%)

(Comparative example 5)
Ultra-thin layer ceramic green sheet was prepared in the same manner as in Example 1 except that the releasing agent of Example 1 was changed to a coating liquid in which one end-epoxy modified polydimethylsiloxane (X22-173DX, manufactured by Shin-Etsu Chemical Co., Ltd.) was used. A release film for production was obtained. The migration amount of PDMS increased because the interaction between the melamine compound and the epoxy group was weak.

(Comparative example 6)
Ultra-thin layer ceramic green sheet was prepared in the same manner as in Example 1 except that the releasing agent of Example 1 was changed to a hydroxy-modified polydimethylsiloxane having one end (X22-170DX, manufactured by Shin-Etsu Chemical Co., Ltd.). A release film for production was obtained. The amount of PDMS transferred was low and good, but the peeling force was heavy probably because PDMS was not exposed on the surface due to the strong interaction between the carbinol group and the melamine compound.

(Comparative Example 7)
A release film for producing an ultrathin layer ceramic sheet was obtained in the same manner as in Example 1 except that the coating liquid had the following composition. Although the amount of PDMS transferred was low and good, the peeling force was heavy probably because PDMS was not exposed on the surface because the interaction between the hydroxyl group and the melamine compound was strong.
Methyl ethyl ketone 49.32 parts by mass Toluene 49.32 parts by mass Melamine-based compound 1.25 parts by mass (imino-type methylated melamine, solid content 80%, Sanwa Chemical Co., Ltd., trade name MX-730, weight average degree of polymerization 2. 4)
Release agent 0.005 parts by mass (polyether-modified OH group-containing polydimethylsiloxane, BYK-377, solid content 100%, manufactured by BYK Japan KK)
Acid catalyst 0.10 parts by mass (p-toluenesulfonic acid, manufactured by Hitachi Chemical Co., Ltd., trade name Dryer (registered trademark) 900, solid content 50%)

(Comparative Example 8)
A release film for producing an ultrathin layer ceramic sheet was obtained in the same manner as in Example 1 except that the coating liquid had the following composition. Although the amount of PDMS transferred was low and good, the peeling force was heavy probably because PDMS was not exposed on the surface because the interaction between the hydroxyl group and the melamine compound was strong.
Methyl ethyl ketone 49.26 parts by mass Toluene 49.26 parts by mass Melamine-based compound 1.18 parts by mass (imino-type methylated melamine, solid content 80%, Sanwa Chemical Co., Ltd., trade name MX-730, weight average degree of polymerization 2. 4)
Release agent 0.20 parts by mass (polyester-modified OH group-containing polydimethylsiloxane, BYK-370, solid content 25%, manufactured by BYK Japan KK)
Acid catalyst 0.10 parts by mass (p-toluenesulfonic acid, manufactured by Hitachi Chemical Co., Ltd., trade name Dryer (registered trademark) 900, solid content 50%)

According to the present invention, the surface of the release layer is smooth, and compared with the conventional release film for producing a ceramic green sheet, the ceramic green sheet does not substantially suffer from defects such as pinholes, and the polyorgano It is possible to manufacture a ceramic green sheet having an ultrathin layer of 0.2 to 1.0 μm in which migration of siloxane is small.

Claims (5)

A biaxially oriented polyester film is used as a base material, and the base material has a surface layer A which does not substantially contain inorganic particles on at least one surface thereof, and at least one surface of the surface layer A is provided directly or with another layer. The release layer is laminated via, the release layer is obtained by curing a composition containing at least a release agent and a melamine compound, the release agent is a polyorganosiloxane containing a carboxyl group. And a release film for producing a ceramic green sheet, in which the content of the melamine compound is 80% by mass or more based on the solid content of the composition for forming the release layer. The surface layer A having substantially no inorganic particles on one surface of the base material, the surface layer B on the opposite side of the base material from the surface layer A, and the surface layer B containing particles, The release film for producing a ceramic green sheet according to claim 1, wherein at least a part of the particles are silica particles and/or calcium carbonate particles, and the total content of the particles with respect to the mass of the surface layer B is 5000 to 15000 ppm. 3. The ceramic green sheet according to claim 1, wherein the release layer has a release layer having a surface area average roughness (Sa) of 7 nm or less and a maximum protrusion height (P) of 100 nm or less. Release film. It is a manufacturing method of the ceramic green sheet which shape|molds a ceramic green sheet using the release film for ceramic green sheet manufacture in any one of Claims 1-3, Comprising: The molded ceramic green sheet is 0.2 micrometer-1. A method for producing a ceramic green sheet having a thickness of 0.0 μm. A method of manufacturing a ceramic capacitor, which employs the method of manufacturing a ceramic green sheet according to claim 4.