KR20210022163A - Release film for manufacturing ceramic green sheet - Google Patents

Abstract

In the present invention, even an ultra-thin ceramic green sheet having a thickness of 1 μm or less can be peeled off with a low and uniform force, there is no fear of defects such as pinholes, and the transfer of silicon components to the ceramic green sheet is suppressed. It is to provide a release film for manufacturing a ceramic green sheet.
In the present invention, a biaxially oriented polyester film is used as a base material, the base material has a surface layer A that does not contain substantially inorganic particles on at least one side, and is directly or other on the surface of the surface layer A on at least one side. The release layer is laminated through the layer, the release layer is formed by curing a composition containing at least a release agent and a melamine-based compound, the release agent is a polyorganosiloxane containing a carboxyl group, and the content of the melamine-based compound is It relates to a release film for producing a ceramic green sheet having 80% by mass or more based on the solid content of the release layer-forming composition.

Description

Release film for manufacturing ceramic green sheet {RELEASE FILM FOR MANUFACTURING CERAMIC GREEN SHEET}

The present invention relates to a release film for manufacturing a ceramic green sheet, and more particularly, it is possible to suppress the occurrence of process defects due to pinholes and uneven thickness during the production of an ultra-thin ceramic green sheet, and the silicon component in the release layer is The present invention relates to a release film for producing an ultra-thin layer ceramic green sheet, which can suppress migration to the produced ceramic green sheet.

Conventionally, a release film in which a polyester film is used as a substrate and a release layer is laminated thereon is used for forming ceramic green sheets such as multilayer ceramic capacitors and ceramic substrates. In recent years, along with the miniaturization and increase in capacity of multilayer ceramic capacitors, the thickness of the ceramic green sheet also tends to become thinner. The ceramic green sheet is formed by applying a slurry containing a ceramic component such as barium titanate and a binder resin to a mold release film and drying it. After the electrode is printed on the molded ceramic green sheet and peeled from the release film, the ceramic green sheet is laminated, pressed, fired, and coated with external electrodes to manufacture a multilayer ceramic capacitor. In the case of forming a ceramic green sheet on the surface of the release layer of a polyester film, there is a problem in that the minute protrusions on the surface of the release layer affect the formed ceramic green sheet, and defects such as crawling and pinholes are likely to occur. . Therefore, various methods have been developed for realizing the surface of the release layer having excellent flatness (see, for example, Patent Documents 1 and 2).

However, in recent years, further thinning of ceramic green sheets has progressed, and ceramic green sheets having a thickness of 1.0 µm or less, particularly 0.2 µm to 1.0 µm, have been required. Since the strength of the ceramic green sheet decreases when thinning proceeds, it has been required to not only smooth the surface of the release layer, but also lower and uniform the peeling force when the ceramic green sheet is peeled from the release film. That is, when peeling the ceramic green sheet from the release film, it has become more important to reduce the force applied to the ceramic green sheet as much as possible so as not to damage the ceramic green sheet.

In addition, the silicon component in the release layer may be easily transferred to the surface in contact with the release layer in the ceramic green sheet to be produced. The surface to which the silicone has been transferred causes slippage, and the adhesiveness is deteriorated. When a ceramic green sheet is manufactured from a release film in which the silicon component is easily transferred, and further, a multilayer ceramic product is manufactured using the ceramic green sheet, when pressure is applied between the laminated ceramic green sheets, the multilayer ceramic product There is a case where a shift in the plane direction occurs between the layers of. When such a deviation occurs, the positional accuracy of electrodes and the like in the obtained multilayer ceramic product is lowered, and product performance of the multilayer ceramic product cannot be obtained. For this reason, a release film with little transition of the silicon component to the ceramic green sheet is required.

Therefore, by using a polyorganosiloxane having at least one hydroxyl group per molecule and a melamine-based resin reacting with a hydroxyl group, a release film with a small amount of silicone migration has been proposed (for example, Patent Document 3 Reference). However, although the amount of migration is small, since the hydroxyl groups of the polyorganosiloxane exhibit a strong interaction with the melamine-based resin in the drying process, it is difficult for silicone to come out to the surface of the finally produced release layer. Peeling force increased, and damage was sometimes given to the ceramic green sheet.

Japanese Unexamined Patent Publication No. 2000-117899 International Publication No. 2013/145864 Japanese Unexamined Patent Publication No. 2017-007227

The present invention has been made against the background of these prior art problems. In other words, it maintains high smoothness of the surface of the release layer of the release film, and because the peeling force is low and uniform, even an ultra-thin layer product with a thickness of 1㎛ or less can form a ceramic green sheet with few defects. It is intended to provide a release film for manufacturing a ceramic green sheet in which migration of a silicon component is suppressed.

The inventors of the present invention have studied intensively in order to solve the above problems, using a polyester film, providing a release layer on at least one side, and using a polyorganosiloxane containing at least a melamine-based compound and a carboxyl group in the release layer. It has been discovered that by setting the composition to be cured, the transition of the silicone component to the ceramic green sheet can be suppressed, and a release film for producing a ceramic green sheet excellent in peelability can be provided.

That is, the present invention has the following configuration.

1.A biaxially oriented polyester film is used as a substrate, the substrate has a surface layer A that does not contain substantially inorganic particles on at least one side, and is released directly on the surface of the surface layer A on at least one side or through another layer. The layers are laminated, the release layer is formed by curing a composition containing at least a release agent and a melamine-based compound, the release agent is a polyorganosiloxane containing a carboxyl group, and the content of the melamine-based compound is used for forming the release layer. A release film for producing a ceramic green sheet having 80% by mass or more based on the solid content of the composition.

2. Has a surface layer A that does not contain substantially inorganic particles on one side of the substrate, has a surface layer B on the opposite side of the surface layer A of the substrate, and the surface layer B contains particles, and at least a part of the particles are silica particles and /Or the release film for producing a ceramic green sheet according to the first item, which is calcium carbonate particles, and wherein the total content of the particles relative to the mass of the surface layer B is 5000 to 15000 ppm.

3. The release film for producing a ceramic green sheet according to the first or second aspect, wherein the region surface average roughness (Sa) of the release layer of the release film is 7 nm or less, and the maximum protrusion height (P) is 100 nm or less.

4. A method for producing a ceramic green sheet for forming a ceramic green sheet using the release film for producing a ceramic green sheet according to any one of the first to third parts, wherein the formed ceramic green sheet has a thickness of 0.2 µm to 1.0 µm. Method of manufacturing a ceramic green sheet having.

5. A method for manufacturing a ceramic capacitor employing the method for manufacturing a ceramic green sheet according to the fourth aspect.

In the release film for manufacturing the ultra-thin ceramic green sheet of the present invention, the surface of the release layer is smooth, and compared with the conventional release film for ceramic green sheet production, process defects occur due to pinholes and non-uniform thickness during ceramic green sheet production. In addition, the transition of the silicon component in the release layer to the ceramic green sheet is small, so that a ceramic green sheet having an ultrathin layer of 0.2 to 1.0 µm can be suitably manufactured.

Hereinafter, the present invention will be described in detail.

The release film for producing an ultra-thin ceramic green sheet of the present invention has a surface layer A that does not contain substantially inorganic particles on at least one side of the biaxially oriented polyester film, and on the surface layer A, directly or through another layer, at least melamine It is preferable that a release layer formed by curing a composition containing a system compound and a polyorganosiloxane containing a carboxyl group is laminated.

(Polyester film)

The polyester constituting the biaxially oriented polyester film used as a base material in the present invention is not particularly limited, and a film-molded polyester generally used as a base material for a release film can be used, but preferably, It is preferable that it is a crystalline linear saturated polyester composed of an aromatic dibasic acid component and a diol component, such as polyethylene terephthalate, polyethylene-2,6-naphthalate, polybutylene terephthalate, and polytrimethylene tere. A phthalate or a copolymer containing the constituent components of these resins as a main component is more suitable, and a polyester film formed from polyethylene terephthalate is particularly suitable. In polyethylene terephthalate, the repeating unit of ethylene terephthalate is preferably 90 mol% or more, more preferably 95 mol% or more, and a small amount of other dicarboxylic acid components and diol components may be copolymerized, but from the viewpoint of cost, terephthalic acid And ethylene glycol is preferred. Further, well-known additives such as antioxidants, light stabilizers, ultraviolet absorbers, crystallizers, and the like may be added within a range that does not impair the effect of the film of the present invention. It is preferable that a polyester film is a biaxially oriented polyester film from reasons, such as the height of the elastic modulus in a bidirectional direction.

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 fracture does not occur much in the stretching process. On the contrary, if it is 0.70 dl/g or less, it is preferable because it has good cutting properties when cutting to a predetermined product width, and dimensional defects do not occur. In addition, it is preferable to sufficiently vacuum-dry the raw material pellets.

The method for producing the biaxially oriented 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 is melted with an extruder, extruded into a film, and cooled with a rotary cooling drum to obtain an unstretched film, which can be obtained by biaxially stretching the unstretched film. The biaxially stretched film is a method of sequentially biaxially stretching a uniaxially stretched film in a vertical direction or a horizontal direction in a horizontal direction or a vertical direction, or a method of simultaneously biaxially stretching an unstretched film in a vertical direction and a horizontal direction You can get it.

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

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

Although the biaxially oriented polyester film base material may be a single layer or a multilayer of two or more layers, it is preferable to have a surface layer A substantially free of inorganic particles on at least one side. 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. In the lamination structure, if the layer on the side to which the release layer is applied is the surface layer A, the layer on the opposite side is the surface layer B, and the other deep layer is the layer C, the layer structure in the thickness direction is the release layer/A. A laminated structure, such as /B or a release layer/A/C/B, is mentioned. Naturally, the layer C may be composed of a plurality of layers. 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 shape.

In the biaxially oriented polyester film base material in this invention, it is preferable that the surface layer A which forms the surface to which a release layer is applied does not contain an inorganic particle substantially. 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, it is preferable that pinholes or the like are less likely to occur during molding of the super-thin ceramic green sheet to be laminated. It can be said that the smaller the area 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, in the case of providing an anchor coat layer or the like described later on the surface layer A, it is preferable that the coat layer does not contain substantially inorganic particles, and the area surface average roughness (Sa) after lamination of the coat layer falls within the above range. It is desirable. In the present invention, ``substantially free of inorganic particles'' means a content that is 50 ppm or less, preferably 10 ppm or less, and most preferably less than the detection limit when the inorganic elements are quantified by fluorescence X-ray analysis. do. This is because even if inorganic particles are not actively added to the film, contaminants derived from foreign substances or contaminants adhered to the line or device in the manufacturing process of the raw resin or film may be peeled off and mixed into the film. .

In the biaxially oriented polyester film base material in the present invention, the surface layer B forming the opposite surface to the surface to which the release layer is applied is preferably containing particles from the viewpoint of the sliding property of the film and the easiness of air removal, In particular, it is preferable to use silica particles and/or calcium carbonate particles. The content of the particles to be contained is preferably 5000 to 15000 ppm in total of the 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 a range of 5 to 35 nm. When the total of silica particles and/or calcium carbonate particles is 5000 ppm or more and Sa is 1 nm or more, air can be evenly released when the film is rolled up in a roll shape, so that the rolled shape is good and the flatness is good. By doing so, it becomes suitable for manufacture of an ultra-thin ceramic green sheet. In addition, when the total of silica particles and/or calcium carbonate particles is 15000 ppm or less and Sa is 40 nm or less, agglomeration of the lubricant is difficult to occur and coarse projections do not occur. It is preferable because the quality is stable during sheet manufacturing.

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 may 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, hydroxyapatite particles, and the like. Further, examples of the heat-resistant organic particles include crosslinked polyacrylic particles, crosslinked polystyrene particles, benzoguanamine particles, and the like. Further, when using silica particles, porous colloidal silica is preferable, and when using calcium carbonate particles, hard calcium carbonate subjected to a surface treatment with a polyacrylic acid-based polymer compound is preferable from the viewpoint of preventing the lubricant from falling off.

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 diameter of the particles is 0.1 µm or more, the sliding property of the mold release film is good, which is preferable. Moreover, when the average particle diameter is 2.0 micrometers or less, there is no possibility that pinholes are generated in the ceramic green sheet by coarse particles on the surface of the release layer, and it is preferable.

The surface layer B may contain two or more types of particles of different materials. Moreover, you may contain particles of the same type and having different average particle diameters.

In the case where the surface layer B does not contain particles, it is preferable to provide easy activity with a coat layer containing particles on the surface layer B. Although this coat layer is not specifically limited, It is preferable to provide in-line coat which coats during the film-forming of a polyester film. When the surface layer B does not contain particles and has a coating layer containing particles on the surface layer B, the surface of the coating layer is the same as the area surface average roughness (Sa) of the surface layer B described above. It is preferable that the average roughness (Sa) is in the range of 1 to 40 nm. More preferably, it is a range of 5 to 35 nm.

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

It is preferable that the thickness ratio of the surface layer A, which is the layer on the side where the release layer is provided, is 20% or more and 50% or less of the total thickness of the base film. If it is 20% or more, it is difficult to receive the influence of the particles contained in the surface layer B or the like from the inside of the film, and it is preferable that the area surface average roughness Sa satisfies the above range easily. If it is 50% or less of the thickness of all the layers 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 economical efficiency, 50 to 90 mass% of film scrap or recycled raw materials for PET bottles can be used for the layers other than the surface layer A (surface layer B or the intermediate layer C described above). Also in this case, it is preferable that the type and amount of the lubricant contained in the surface layer B, the particle diameter, and the area surface average roughness Sa satisfy the above range.

In addition, a coat layer may be provided on the surface of the surface layer A and/or the surface layer B before stretching or after uniaxial stretching in the film forming process on the surface of the surface layer A and/or surface layer B in order to improve the adhesion of the release layer to be applied later or to prevent charging. , Corona treatment, etc. can also be performed.

(Structure of release layer)

It is preferable that a composition containing at least a melamine-based compound and a polyorganosiloxane containing a carboxyl group is cured in the mold release layer in the present invention. In addition to the resin and additives, other components may be added as long as the effect of the present invention is not impaired.

As the melamine-based compound used for the release layer in the present invention, a general one can be used, and it is not particularly limited, but it is obtained by condensing melamine and formaldehyde, and is obtained by condensation of melamine and formaldehyde, and a triazine ring and a methylol group in one molecule, and It is preferable to each have at least one alkoxymethyl group. Specifically, a methylol melamine derivative obtained by condensing melamine and formaldehyde is preferably a compound obtained by dehydrating condensation reaction of methyl alcohol, ethyl alcohol, isopropyl alcohol, butyl alcohol, or the like as a lower alcohol, and the like. Examples of methylolated melamine derivatives include monomethylol melamine, dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, and hexamethylol melamine. Even if one type is used, two or more types may also be used.

It is preferable that the release layer in the present invention has a high crosslinking density and a high modulus of elasticity in order to suppress the deformation of the release layer occurring at the time of peeling and to make the peeling force low and uniform. Therefore, it is preferable to use hexamethylol melamine or hexaalkoxymethyl melamine having more crosslinking points in one molecule, but hexaalkoxymethyl melamine having more excellent reactivity is more preferable, and in particular, it is preferable to use hexamethoxymethyl melamine. Do. At this time, with hexamethylol melamine, X is a methylol group (-CH ₂ -OH) in the following formula (a). The hexaalkoxymethyl melamine is a methylol melamine derivative obtained by dehydration and condensation reaction using alcohol, and X is (-CH ₂ -OR, R is an alkyl group having 1 to 4 carbon atoms). With hexamethoxymethyl melamine, X is (-CH ₂ -OMe).

[Formula 1]

X in said (a) may be the same or different, respectively. Moreover, said R may be the same or different, respectively. In addition, X may be (-H).

In the melamine-based compound used for the release layer in the present invention, it is preferable that the weight average molecular weight is 250 or more and 1000 or less. More preferably, the weight average molecular weight is 250 or more and 900 or less, and still more preferably 300 or more and 800 or less. When the weight average molecular weight is 1000 or less, a crosslinking reaction is likely to proceed, a film having a higher crosslinking density can be formed, and the peeling force can be made light, which is preferable. When the weight average molecular weight is 250 or more, it is preferable because the crosslinking density does not become excessively high and curls do not deteriorate. In addition, the weight average molecular weight in this specification is a value in terms of standard polystyrene measured by the gel permeation chromatography (GPC) method.

When the weight average molecular weight of the melamine-based compound is 250 to 1000, it means that the melamine-based compound used in the present invention contains a large amount of mononuclear bodies. The mononuclear body has a higher crosslinking point than a polynuclear body formed by condensation of two or more melamine derivatives, and is therefore excellent in reactivity, so that a release layer having high crosslinking density and excellent peelability can be obtained. The higher the content of the mononuclear material is, the more preferable it is, and it is most preferable to use a melamine-based compound composed of only the mononuclear material.

The weight average molecular weight can also be represented by a weight average polymerization degree. The weight average polymerization degree of the melamine-based compound to be used is preferably 2.0 or less, more preferably 1.5 or less, and the smaller it is, the more appropriately it can be used. When the weight-average polymerization degree is 2.0 or less, the content of the mononuclear body contained in the melamine-based compound increases, so that a release layer having excellent reactivity and excellent peelability can be obtained, which is preferable. In addition, the weight average polymerization degree in this specification is a value computed based on the weight average molecular weight calculated|required in standard polystyrene conversion by gel permeation chromatography.

Melamine-based compounds contain imino groups (-NH ₂ -) in the synthesis process, but polynuclear compounds may be mixed. Even if these melamine derivatives are mixed, the reactivity is excellent as long as the weight average polymerization degree of the melamine-based compound is within the above range, and each can be suitably used.

In the release layer in the present invention, the melamine-based compound is preferably 80% by mass or more and 99.9% by mass or less, more preferably 90% by mass or more and 99.9% by mass or less with respect to the solid content of the composition for forming a release layer. , More preferably 95% by mass or more and 99.9% by mass or less. By containing 80 mass% or more of the melamine-based compound, the release layer can obtain a high crosslinking density by self-crosslinking of the melamine-based compound, and deformation of the release layer at the time of peeling can be suppressed. At this time, the solid content of the composition for forming a release layer may be regarded as the sum of substantially the solid content of the melamine-based compound and the solid content of the release agent, since the solvent and the acid catalyst are substantially evaporated during the drying process.

It is preferable to add an acid catalyst to the mold release layer in the present invention in order to accelerate the crosslinking reaction of the melamine-based compound, and it is preferable to add an acid catalyst to the composition for forming the mold release layer to apply and cure it. The acid catalyst to be 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-based catalyst, for example, p-toluenesulfonic acid, xylenesulfonic acid, cumenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid, trifluoromethanesulfonic acid, etc. can be suitably used. Toluenesulfonic acid can be used particularly suitably.

As the sulfonic acid catalyst used in the present invention, a commercially available catalyst can also be used. Examples of commercially available products include dryer (registered trademark) 900 (p-toluenesulfonic acid, manufactured by Hitachi Kasei), NACURE (registered trademark) DNNDSA series (dinonyl naphthalenedisulfonic acid, manufactured by Kusumoto Kasei), and the same DNNSA series. (Dinonyl naphthalene (mono) sulfonic acid, manufactured by Kusumoto Kasei), DDBSA series (dodecylbenzenesulfonic acid, manufactured by Kusumoto Kasei), copper p-TSA series (p-toluenesulfonic acid, manufactured by Kusumoto Kasei), etc. Can be mentioned.

Since the sulfonic acid catalyst has high acidity and excellent reactivity compared to other acid catalysts such as carboxylic acid, the release layer can be processed at a lower temperature. Therefore, it is preferable because it is possible to suppress a decrease in the flatness of the film due to heat during processing and a deterioration in the appearance of the roll.

The amount of the acid catalyst added is preferably 0.1 to 10% by mass based on the melamine-based compound contained in the mold release layer. More preferably, it is 0.5-8 mass %. More preferably, it is 0.5-5 mass %. If it is 0.1 mass% or more, it becomes easy to advance a hardening reaction, and is preferable. On the other hand, when it is 10 mass% or less, there is no possibility that an acid catalyst will migrate to the ceramic green sheet to be molded, and it is preferable from the point that there is no possibility of adverse effects.

It is preferable to use a polyorganosiloxane containing a carboxyl group as a release agent (an additive that improves the release property of the release layer) used for the release layer in the present invention, from the viewpoint of both releasability and migration amount suppression. Among the polyorganosiloxane structures, a polyorganosiloxane containing a carboxyl group having a polydimethylsiloxane structure (abbreviated as PDMS) can be suitably used.

When the polyorganosiloxane as a releasing agent contains a carboxyl group, the releasing agent does not show a strong interaction with the melamine-based compound in the drying step, it becomes easy to orientate to the surface of the release layer, and good peelability is obtained. Therefore, by using the polyorganosiloxane containing a carboxyl group, the amount of the release agent added can satisfy at least the releasability, which is preferable. Further, it is known that the polyorganosiloxane as a release agent containing a carboxyl group exhibits a weak interaction with the melamine-based compound, so that it is difficult to migrate to the ceramic green sheet, and it is preferable.

The carboxyl group may be introduced at one end of the polyorganosiloxane, may be both ends or side chains, but the one introduced at one end is preferable because it has excellent releasability. Moreover, the position to be introduced may be one or a plurality of positions.

Regarding the carboxyl group-modified polyorganosiloxane, a carboxyl group may be directly bonded to a silicon atom of the polyorganosiloxane, but a carboxyl group may be bonded to the polyorganosiloxane via an alkyl group or an aryl group. However, it is not so preferable that a carboxyl group is bonded to the polyorganosiloxane via an organic group having a repeating structure such as polyether, polyester, polyurethane, or the like.

As the functional group to be introduced into the polyorganosiloxane which is a mold release agent, one molecule may have a functional group other than a carboxyl group, but it is preferable that only a carboxyl group is used. Inclusion of a functional group other than a carboxyl group is not preferable because the molecular interaction with the melamine-based compound increases more than necessary and orientation to the surface of the release layer may be difficult.

Polyorganosiloxanes modified with hydroxyl groups that exhibit strong interactions with melamine compounds react quickly with the melamine compounds in the drying process, so it is difficult to orientate them on the surface of the release layer, and release properties may be difficult to manifest. . Therefore, it is necessary to increase the amount of addition in order to have sufficient releasability, but in that case, the elastic modulus of the release layer is lowered, so that deformation of the release layer at the time of peeling is likely to occur, and the peeling force may increase. Further, when the addition amount of the polyorganosiloxane is increased, the amount of transition 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 40000 or less. More preferably, it is 30000 or less, more preferably 10000 or less, and the smaller the molecular weight, the more appropriately it can be used. When the molecular weight is 40000 or less, the polyorganosiloxane containing a carboxyl group tends to segregate on the surface of the release layer, and the peelability is good, which is preferable.

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

The polydimethylsiloxane containing a carboxyl group in the present invention may be an acrylic resin in which a polydimethylsiloxane is introduced into a side chain of an acrylic main chain containing a carboxyl group. As the acrylic resin in which polydimethylsiloxane is introduced into the side chain in the acrylic main chain containing a carboxyl group, Cymac (registered trademark) US-350, US-352, US-380 (above, manufactured by Doa Gosei), etc. can be used. . Moreover, it does not matter even if it is an acrylic resin in which polydimethylsiloxane was introduced into the side chain in the acrylic main chain containing a carboxyl group and a hydroxyl group in 1 molecule. Examples of acrylic resins in which polydimethylsiloxane is introduced into the side chain to the acrylic main chain containing a carboxyl group and hydroxyl group in one molecule include Cymac (registered trademark) US-450, US-480 (above, manufactured by Toa Gosei), etc. Can be used.

In the release layer in the present invention, it is preferable that the release agent is contained in an amount of 0.1% by mass or more and 20% by mass or less with respect to the solid content of the composition for forming a release layer. More preferably, they are 0.1 mass% or more and 10 mass% or less, More preferably, they are 0.1 mass% or more and 5 mass% or less. If it is 0.1 mass% or more, since releasability improves and peelability of a ceramic green sheet improves, it is preferable. On the other hand, if it is 20 mass% or less, since the elastic modulus of a release layer does not fall too much, and deformation of a release layer occurs at the time of peeling a ceramic green sheet, it is preferable because it can suppress that a peeling force increases. Moreover, when it is 20 mass% or less, it is preferable also from the point that the transfer amount of a mold release agent does not become too high. At this time, the solid content of the composition for forming a release layer may be regarded as the sum of the solid content of the melamine-based compound and the release agent since the solvent and the acid catalyst are substantially evaporated during the drying process.

Although the release layer in the present invention may contain particles or the like having a particle diameter of 1 µm or less, it is more preferable that particles or other protrusions are not contained from the viewpoint of generating pinholes.

Additives, such as an adhesion improver and an antistatic agent, may be added to the release layer in the present invention as long as the effect of the present invention is not impaired. In addition, in order to improve the adhesion to the substrate, it is also preferable to perform pretreatment such as anchor coat, corona treatment, plasma treatment, atmospheric pressure plasma treatment, etc. on the surface of the polyester film before the release coating layer is provided.

(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 thickness of the release coating layer after curing is within a range of 0.01 to 2.0 µm, and 0.01 to 1.0. It is more preferable that it is a micrometer, it is more preferable that it is 0.01-0.8 micrometer, It is more preferable that it is 0.02 to 0.5 micrometer, It is most preferable that it is 0.02 to 0.3 micrometer. When the thickness of the release layer is 0.01 µm or more, peeling performance is obtained, which is preferable. Moreover, if it is 2.0 micrometers or less, curing time can be shortened, flatness of a release film can be maintained, and thickness unevenness of a ceramic green sheet can be suppressed, and it is preferable.

The release layer surface of the release film of the present invention is preferably flat in order not to cause defects in the ceramic green sheet applied and molded thereon, and the area surface average roughness (Sa) is 7 nm or less, and the maximum protrusion height (P) is It is preferably 100 nm or less. Furthermore, it is more preferable that the area surface average roughness is 5 nm or less and the maximum protrusion height is 80 nm or less. When the region surface roughness is 7 nm or less and the maximum protrusion height is 100 nm or less, defects such as pinholes do not occur during formation of 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 is, the more preferable it is, but it does not matter if it is 0.1 nm or more, and it does not matter even if it is 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 does not matter if it is 1 nm or more, and it does not matter if it is 3 nm or more.

Since the release film of the present invention uses a highly flattened base film, the surface of the release layer can be smoothed even if the thickness of the release layer is thinner than 0.5 µm, and furthermore than 0.2 µm. Therefore, even if it is a release layer using a highly reactive melamine-based compound, the occurrence of curls can be suppressed. In addition, since the amount of solvent and resin to be used can be reduced, it is environmentally friendly, and a release film for molding an ultra-thin ceramic green sheet can be produced at low cost.

It is preferable that the surface free energy (γs) of the surface of the release layer of the release layer film of the present invention is 18 mJ/m 2 or more and 35 mJ/m 2 or less. More preferably, they are 23 mJ/m 2 or more and 35 mJ/m 2 or less, and still more preferably 23 mJ/m 2 or more and 30 mJ/m 2 or less. If it is 18 mJ/m 2 or more, crawling is less likely to occur when the ceramic slurry is coated, and thus uniform coating can be performed, which is preferable. Moreover, if it is 35 mJ/m 2 or less, there is no fear that the releasability of the ceramic green sheet will be lowered, which is preferable. By setting it as the said range, there is no crawl at the time of coating, and a release film excellent in releasability can be provided.

It is preferable that the release film of the present invention 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, they are 0.8 mN/mm 2 or more and 2.0 mN/mm 2 or less. When the peeling force is 0.5mN/mm 2 or more, the peeling force is not too light and there is no fear that the ceramic green sheet may float during transportation, and thus, it is preferable. If the peeling force is 2.5mN/mm 2 or less, there is no fear that the ceramic green sheet will be damaged during 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 desirable to have no curls at all. When the thickness is 3 mm or less, curling is reduced when printing electrodes by forming a ceramic green sheet, so that printing accuracy can be improved, which is preferable.

The release film of the present invention is more preferable as the amount of the silicon component transferred to the ceramic green sheet after peeling is small. The amount of silicon component transferred is measured by means of fluorescence X-rays of the Si intensity of the release layer before and after the release film is pseudo-coated and molded with PVB, one of the binder components contained in the ceramic green sheet. It can be evaluated by doing. More specifically, when Si strength of the surface of the release layer is Si (before), and the Si strength of the release surface of the release film after coating and peeling the PVB sheet is Si (after), Si (before) -Si (after) ) Was taken as the transfer amount. The amount of shift 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, occurrence of process defects such as stacking misalignment and adhesion failure is suppressed, and there is no fear of lowering 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 solution obtained by dissolving or dispersing a releasable resin is developed by coating or the like on one side of the polyester film of the base material. After removal by drying, a method of heat drying and heat curing is used. At this time, the drying temperature at the time of solvent drying and thermal curing is preferably 100°C or higher and 180°C or lower, more preferably 100°C or higher and 160°C or lower, and most preferably 100°C or higher and 140°C or lower. The heating time is preferably 30 seconds or less, and more preferably 20 seconds or less. In the case of 180° C. or less, the flatness of the film is maintained, and there is little possibility of causing uneven thickness of the ceramic green sheet, which is preferable. If the temperature is 140°C or less, processing can be performed without impairing the flatness of the film, and the fear of causing the thickness unevenness of the ceramic green sheet is further reduced, which is particularly preferable. If it is lower than 100°C, the curing reaction of melamine does not proceed sufficiently and the elastic modulus of the release layer is lowered, which is not preferable.

In the present invention, the surface tension of the coating solution when applying the release layer is not particularly limited, but is preferably 30 mN/m or less. By making the surface tension as described above, the wettability after coating is improved, and irregularities on the surface of the coating film after drying can be reduced.

In the present invention, it is not particularly limited to the coating liquid when applying the mold release coating layer, 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, it is possible to prevent swelling during drying, to level the coating film, and to improve the smoothness of the surface of the coating film after drying. As the addition amount, it is preferable to add about 10 to 80 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, and a spray coating method. Conventionally known methods, such as a method and an air knife coating method, can be used.

(Ceramic Green Sheet and Ceramic Capacitor)

In general, a multilayer ceramic capacitor has a rectangular parallelepiped ceramic element. Inside the ceramic body, first internal electrodes and second internal electrodes are alternately provided along the thickness direction. The first internal electrode is exposed on the first end surface of the ceramic element. A first external electrode is provided on the first end face. The first internal electrode is electrically connected to the first external electrode in the first cross section. The second internal electrode is exposed on the second end face of the ceramic element. A second external electrode is provided on the second end face. The second internal electrode is electrically connected to the second external electrode in the second cross section.

The release film for manufacturing a ceramic green sheet of the present invention is used to manufacture 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 constituting a ceramic body is applied and dried. As for the thickness of the ceramic green sheet, an extremely thin product having a thickness of 0.2 to 1.0 µm has been demanded. On the coated and dried ceramic green sheet, a conductive layer for constituting the first or second internal electrode is printed. The ceramic green sheet, the ceramic green sheet on which the conductive layer for constituting the first internal electrode is printed, and the ceramic green sheet on which the conductive layer for constituting the second internal electrode is printed are appropriately laminated and pressed to obtain a mother laminate. . The mother laminated body is divided into plural parts to produce a raw ceramic body. A ceramic body is obtained by firing the green ceramic body. After that, the multilayer ceramic capacitor can be completed by forming the first and second external electrodes.

Example

Hereinafter, the present invention will be described in more detail using examples, but the present invention is not limited at all by these examples. The characteristic values used in the present invention were evaluated using the following method.

(Surface roughness)

It is a value measured under the following conditions using a non-contact surface shape measurement system (VertScan R550H-M100). As for the area surface average roughness (Sa), the average value of 5 measurements was adopted, and the maximum protrusion height (P) was measured 7 times, and the maximum value of 5 times was used excluding the maximum value and the minimum value.

(Measuring conditions)

Measurement mode: WAVE mode

·Objective lens: 10 times

0.5×Tube lens

·Measurement area 936㎛×702㎛

(Interpretation conditions)

Face correction: 4th correction

Interpolation processing: full interpolation

(Surface free energy)

Water (droplet amount 1.8 μL) and diiodo on the release surface of the release film using a contact angle meter (manufactured by Kyowa Kaimen Chemical Co., Ltd.: fully automatic contact angle meter DM-701) under the conditions of 25°C and 50% RH. Droplets of methane (droplet volume 0.9 µL) and ethylene glycol (droplet volume 0.9 µL) were prepared, and the contact angle was measured. As the contact angle, the contact angle 10 seconds after dropping each liquid onto the release film was adopted. The contact angle data of water, diiodomethane, and ethylene glycol obtained by the above method were calculated using the "Kitazaki-Hatta" 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 sum of the components was taken as surface free energy γs. This calculation was performed using the calculation software in the present contact angle meter software (FAMAS).

(Evaluation of coating property of ceramic slurry)

The composition made of the following material was stirred and mixed, and dispersed for 30 minutes with zirconia beads having a diameter of 0.5 mm using a bead mill to obtain a ceramic slurry.

Toluene　　　　　　　　　　　　　　　　　　　　 76.3 parts by mass

Ethanol　　　　　　　　　　　　　　　　　　　　 76.3 parts by mass

35.0 parts by mass of barium titanate (HPBT-1 manufactured by Fuji Titanium Corporation)

Polyvinyl Butyral (Slec BM-S manufactured by Sekisui Chemical) 3.5 parts by mass

DOP (Dioctyl Phthalate)　 　　　　　　　　　　　　1.8 parts by mass

Subsequently, coating was applied to the release surface of the obtained release film sample so that the dried slurry became 1 µm using an applicator, and after drying at 90°C for 1 minute, coatability was evaluated according to the following criteria.

○: It is coated on the entire surface without crawling or the like.

?: There is a little crawling at the coating end, but it is coated almost entirely.

X: There is a lot of crawling, and it is not coated.

(Pin hole evaluation of ceramic green sheet)

In the same manner as in the evaluation of the coating property of the ceramic slurry, a ceramic green sheet having a thickness of 1 µm was formed on the release surface of the release film. Next, the mold release film was peeled from the molded mold release film with a ceramic green sheet to obtain a ceramic green sheet. In the center region of the film width direction of the obtained ceramic green sheet, light was irradiated from the opposite surface of the coated surface of the ceramic slurry in the range of 25 cm 2, the state of occurrence of pinholes visible through the light was observed, and visually determined based on the following criteria.

○: No pinhole occurrence

△: almost no occurrence of pinholes

×: There are many occurrences of pinholes

(Evaluation of peelability of ceramic green sheet)

The composition made of the following material was stirred and mixed, and dispersed for 60 minutes with zirconia beads having a diameter of 0.5 mm using a bead mill to obtain a ceramic slurry.

Toluene　　　　　　　　　　　　　　　　　　　　　 38.3 parts by mass

Ethanol　　　　　　　　　　　　　　　　　　　　　 38.3 parts by mass

64.8 parts by mass of barium titanate (HPBT-1 manufactured by Fuji Titanium Corporation)

Polyvinyl Butyral (Slec BM-S manufactured by Sekisui Chemical) 6.5 parts by mass

DOP (Dioctyl Phthalate)　　　　　　　　　　　　　 3.3 parts by mass

Subsequently, the resulting mold release film sample was coated on the mold release surface of the molded release film sample so that the dried slurry had a thickness of 10 mu m using an applicator, and dried at 90 DEG C for 1 minute to form a ceramic green sheet on the mold release film. The obtained release film with a ceramic green sheet was subjected to static elimination using a static eliminator (manufactured by Keyence Corporation, SJ-F020), and then peeled off at a peel angle of 90 degrees and a peel rate of 10 m/min with a width of 30 mm. The stress applied at the time of peeling was measured, and it was set as peeling force. It was determined by the following criteria from the value of the obtained peeling force.

○: 0.5mN/mm2 or more, 2.0mN/mm2 or less

△: greater than 2.0mN/mm2 and less than 2.5mN/mm2

×: greater than 2.5mN/mm2

(Evaluation of transition amount of silicone component in release layer)

The composition made of the following 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 (Slec BM-S manufactured by Sekisui Chemical) 10.0 parts by mass

Subsequently, a polyvinyl butyral (PVB) sheet after drying using an applicator was coated on the release surface of the obtained release film sample so that it became 10 µm, dried at 90°C for 1 minute, the release film was peeled off, and the release film of the peeled PVB sheet The Si intensity of the surface (release layer) in contact and the release layer of the release film before applying the PVB sheet was measured with a fluorescent X-ray apparatus (ZSX Primus2 manufactured by Rigaku), and the amount of transfer of the silicon component 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: 30mm, atmosphere: vacuum

The transfer amount of the silicon component is the Si strength of the release surface of the release film before coating the PVB sheet as Si (before), and the Si strength of the release surface of the release film after coating and peeling the PVB sheet is Si (after), The value obtained by subtracting Si (after) from Si (before) was taken as the transfer amount of the silicon component. It was judged by the following criteria from the numerical value of the amount of transition of the obtained silicone component.

○: 0.04kcps or less

?: greater than 0.04 kcps and less than 0.10 kcps.

×: 0.10kcps or more

(Curl evaluation of release film)

The mold release film sample was cut into a size of 10 cm x 10 cm, and heat treatment was performed in a hot air oven at 100° C. for 15 minutes to prevent tension from being applied to the release film. Thereafter, after taking out from the oven and cooling to room temperature, the release film sample was placed on the glass plate so that the release surface was above, and the height of the portion floating from the glass plate at the four corners was measured. The average value of the floating amount of the four corners measured at this time was taken as the curl amount. Curling property was evaluated based on the following criteria.

(Double-circle): The curl is 1 mm or less, and it is hardly curled.

(Circle): The curl was larger than 1 mm, and it was 3 mm or less, and curls were seen a little.

(Triangle|delta): The curl was larger than 3 mm, and it was 10 mm or less, and curl was seen.

X: The curl was curled larger than 10 mm.

(Measurement method of weight average degree of polymerization)

Analysis condition

16 mg of a sample was weighed and dissolved in 8 ml of chloroform. The sample solution was filtered through a 0.2 µm membrane filter, and the obtained sample solution was subjected to gel permeation chromatography (GPC) analysis under the following conditions.

Device: 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: 1.0ml/min

Concentration: 0.2%

Injection volume: 50 μL

Temperature: 40℃

Detector: RI

The weight average molecular weight was calculated in terms of polystyrene, and the weight average polymerization degree was calculated based on the value. As polystyrene, PStQuick C (TOSOH) of the PStQuick series was used. Among the polystyrenes added to PStQuick C (TOSOH), polystyrene Mw2110000, 427000, and 37900, which significantly 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 apparatus, a continuous esterification reaction apparatus consisting of a three-stage complete mixing tank having a stirring apparatus, a condenser, a raw material input port, and a product discharge port was used. TPA (terephthalic acid) is 2 tons/hour, EG (ethylene glycol) is 2 moles per 1 mole of TPA, and antimony trioxide is formed in an amount such that Sb atoms are 160 ppm with respect to PET, and the slurry is used as an esterification reaction device. It was continuously supplied to the 1st esterification reaction tube of, and was made to react at 255 degreeC with an average residence time of 4 hours at normal pressure. Subsequently, the reaction product in the first esterification reaction tube is continuously taken out of the system and supplied to the second esterification reaction tube, and distilled off from the first esterification reaction tube in the second esterification reaction tube. EG to be obtained is supplied in an amount of 8% by mass to the resulting PET, and further, an EG solution containing magnesium acetic acid tetrahydrate in an amount of 65 ppm of Mg atoms to the resulting PET, and the resulting PET An EG solution containing TMPA (trimethyl phosphate) in an amount of 40 ppm of P atoms was added thereto, and the reaction was carried out at 260°C for an average residence time of 1 hour at normal pressure. Subsequently, the reaction product from the second esterification reaction tube was continuously taken out of the system and supplied to the third esterification reaction tube, and averaged at a pressure of 39 MPa (400 kg/cm 2) using a high-pressure disperser (manufactured by Nippon Seiki). 0.2% by mass of porous colloidal silica having an average particle diameter of 0.9 μm subjected to dispersion treatment of 5 passes, and 0.4% by mass of synthetic calcium carbonate having an average particle diameter of 0.6 μm obtained by adhering 1% by mass of an ammonium salt of polyacrylic acid per calcium carbonate, The reaction was carried out at 260°C for an average residence time of 0.5 hours at normal pressure while being added as each 10% EG slurry. The esterification reaction product produced in the third esterification reaction tube is continuously supplied to a three-stage continuous polycondensation reactor for polycondensation, and a 95% cut diameter of 20 μm stainless steel fiber is filtered through a sintered filter. After performing ultrafiltration, it was extruded in water, cut into chips after cooling, and obtained PET chips having 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 manufacture of the PET(I) chip, a PET chip having an intrinsic viscosity of 0.62 dl/g containing no particles such as calcium carbonate or silica was obtained (hereinafter, abbreviated as PET(II)).

(Preparation of polyethylene terephthalate pellets (PET(III)))

PET(I) is similar to PET(I), except that the type and content of the particles of PET(I) are changed to 0.75% by mass of synthetic calcium carbonate having an average particle diameter of 0.9 μm in which an ammonium salt of polyacrylic acid is adhered at 1% by mass per calcium carbonate. A chip was obtained (hereinafter, abbreviated as PET(III)). The lubricant content in the PET chip 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 in which stainless steel fibers having a 95% cut diameter of 15 μm were sintered, and a 95% cut diameter of 15 μm. Two stages of filtration of a filter obtained by sintering stainless steel particles are performed, and they are joined in the feed block, and PET(I) is used as the surface layer B (anti-release surface side layer), and PET(II) is used as the surface layer A (release 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 an electrostatic bonding method, and undrawn polyethylene having an intrinsic viscosity of 0.59 dl/g A terephthalate sheet was obtained. The layer ratio was adjusted to be PET(I)/(II)=60% by mass/40% by mass by calculating the discharge amount of each extruder. Next, after heating this unstretched sheet with an infrared heater, it stretched 3.5 times in the longitudinal direction by the speed difference between rolls at a roll temperature of 80 degreeC. Thereafter, it was guided by a tenter, and stretching was performed 4.2 times in the transverse direction at 140°C. Subsequently, heat treatment was performed at 210°C in the heat setting zone. Thereafter, a relaxation treatment of 2.3% was performed at 170°C in the transverse direction to obtain a biaxially stretched polyethylene terephthalate film X1 having a thickness of 31 μm. Sa of the surface layer A of the obtained film X1 was 2 nm, and Sa of the surface layer B was 28 nm.

(Production of laminated film X2)

The layer structure and stretching conditions similar to those of the laminated film X1 were not changed, and the thickness was adjusted by changing the speed at the time of casting to obtain a biaxially stretched polyethylene terephthalate film X2 having a thickness of 25 µm. Sa of the surface layer A of the obtained film X2 was 3 nm, and Sa of the surface layer B was 29 nm.

(Laminated film X3)

As the laminated film X3, A4100 (Cosmo Shine (registered trademark), manufactured by Toyobo) having a thickness of 25 μm was used. A4100 has a configuration in which the film contains substantially no particles, and a coating layer containing particles is provided on the surface layer B side by in-line coating. Sa of the surface layer A of the laminated film X3 was 1 nm, and 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 Corporation) having a thickness of 25 µm was used. E5101 has a structure in which particles are contained in a film. Sa of the surface layer A of the laminated film X4 was 24 nm, and Sa of the surface layer B was 24 nm.

(Example 1)

On the surface layer A of the laminated film X1, a coating solution having the following composition was applied using reverse gravure so that the thickness of the release layer after drying was 50 nm, and dried at 140° C. for 15 seconds to obtain a release film for producing an ultra-thin ceramic green sheet. . A ceramic slurry was applied to the obtained mold release film to evaluate coatability, peelability, transfer amount of silicon components, pinholes, curls, etc., and satisfactory 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 methylated melamine, solid content 100%, manufactured by Sanwa Chemical, brand name MW-30M, weight average degree of polymerization 1.3)

Release agent　　　　　　　　　　　　　　　　 　　 0.05 parts by mass

(One terminal carboxyl-modified polydimethylsiloxane, X22-3710, solid content 100%, manufactured by Shin-Etsu Chemical Co., Ltd., an alkyl group interposed between the dimethylsiloxane and the carboxyl group)

Acid catalyst　　　　　　　　　　　　　　　　　　　 0.10 parts by mass

(p-toluenesulfonic acid, manufactured by Hitachi Kasei, brand name Dryer (registered trademark) 900, solid content 50%)

(Example 2)

Ultra-thin ceramic green in the same manner as in Example 1, except that the content of the full ether methylated melamine in the coating solution of Example 1 was 0.98 parts by mass and the amount of the release agent (X22-3710) was changed to 0.02 parts by mass. A release film for sheet production was obtained.

(Example 3)

Ultra-thin ceramic green in the same manner as in Example 1, except that the content of the full ether methylated melamine in the coating solution of Example 1 was 0.9 parts by mass and the amount of the release agent (X22-3710) was changed to 0.1 parts by mass. A release film for sheet production was obtained.

(Example 4)

Ultra-thin ceramic green in the same manner as in Example 1, except that the content of the full ether methylated melamine in the coating solution of Example 1 was 0.8 parts by mass and the amount of the release agent (X22-3710) was changed to 0.2 parts by mass. A release film for sheet production was obtained.

(Examples 5 to 8)

Except having changed the film thickness of the release layer of Example 1 to the film thickness shown in Table 1, it carried out similarly to Example 1, and obtained the release film for ultra-thin ceramic green sheet production.

(Example 9)

Except having changed the base film of Example 1 to the laminated film X2 of 25 micrometers in film thickness, it carried out similarly to Example 1, and obtained the release film for ultra-thin ceramic green sheet production.

(Example 10)

Except having changed the laminated film of Example 1 to the laminated film X3, it carried out similarly to Example 1, and obtained the release film for ultra-thin ceramic green sheet production.

(Example 11)

Except having changed the drying conditions of Example 1 to 90 degreeC 15 second, it carried out similarly to Example 1, and obtained the release film for ultra-thin ceramic green sheet production.

(Example 12)

Except having changed the drying conditions of Example 1 to 110 degreeC 15 second, it carried out similarly to Example 1, and obtained the release film for ultra-thin ceramic green sheet production.

(Example 13)

Release film for producing ultra-thin ceramic green sheet in the same manner as in Example 1, except that a coating solution obtained by changing the release agent of Example 1 to X22-3701E (branched carboxyl-modified polydimethylsiloxane, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) was used. Got it.

(Example 14)

Release film for producing ultra-thin ceramic green sheet in the same manner as in Example 1, except that a coating solution obtained by changing the release agent of Example 1 to X22-162C (double-ended carboxyl-modified polydimethylsiloxane, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) was used. Got it.

(Example 15)

Ultrathin layer ceramic green sheet in the same manner as in Example 1, except for using the coating solution obtained by changing the full ether methylated melamine of Example 1 to MW-30 (full ether methylated melamine, manufactured by Sanwa Chemical Co., Ltd., weight average polymerization degree 1.5). A release film for production was obtained.

(Example 16)

Ultrathin layer ceramic green sheet in the same manner as in Example 1, except that the coating solution obtained by changing the full ether methylated melamine of Example 1 to MS-21 (full ether methylated melamine, manufactured by Sanwa Chemical Co., Ltd., weight average polymerization degree 1.8) was used. A release film for production was obtained.

(Example 17)

Ultra-thin layer in the same manner as in Example 1 except that the full ether methylated melamine of Example 1 was changed to MX-730 (imino-methylated melamine, solid content 80%, manufactured by Sanwa Chemical Co., Ltd., weight average polymerization degree 2.4). A release film for manufacturing a ceramic green sheet was obtained.

(Comparative Example 1)

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

(Comparative Example 2)

In place of the laminated film X1, a release film for ultra-thin ceramic sheet production was obtained in the same manner as in Example 1 except for changing to the laminated film X4 (E5101-25 μm, manufactured by Toyobo). In E5101, both the surface layer A and the surface layer B contained particles, and the Sa of both layers of the surface layer A and the surface layer B was 24 nm. Because of the large surface roughness, pinholes occurred in the ceramic green sheet.

(Comparative Example 3)

Except having changed the coating liquid to the coating liquid of the following composition, it carried out similarly to Example 1, and obtained the release film for ultra-thin ceramic sheet production. In Comparative Example 3 in which a large amount of a release agent was added and the melamine-based compound was only 70% by mass of the release layer, the amount of PDMS transferred to the ceramic green sheet increased.

Methyl ethyl ketone　　　　　　　　　　　　　　 49.45 parts by mass

Toluene　　　　　　　　　　　　　　　　　　 49.45 parts by mass

Melamine compound　　　　　　　　　　　　　　 0.70 parts by mass

(Full ether methylated melamine, solid content 100%, manufactured by Sanwa Chemical, brand name MW-30M, weight average degree of polymerization 1.3)

Release agent　　　　　　　　　　　　　　　　　　　 0.30 parts by mass

(One terminal carboxyl-modified polydimethylsiloxane, X22-3710, 100% solid content, manufactured by Shin-Etsu Chemical Co., Ltd.)

Acid catalyst　　　　　　　　　 　　　　　　　　　 0.10 parts by mass

(p-toluenesulfonic acid, manufactured by Hitachi Kasei, brand name Dryer (registered trademark) 900, solid content 50%)

(Comparative Example 4)

Except having changed the coating liquid to the coating liquid of the following composition, it carried out similarly to Example 1, and obtained the release film for ultra-thin ceramic sheet production. BYK-370 is a polydimethylsiloxane having two types of functional groups (ester group and hydroxyl group) in one molecule. The amount of PDMS shifted was low and good, but the interaction between the hydroxyl group and the melamine-based compound was strong, and the peeling force became heavy because PDMS did not appear on the surface.

Methyl ethyl ketone　　　　　　　　　　　　　　 48.38 parts by mass

Toluene　　　　　　　　　　　　　　　　　　 48.37 parts by mass

Melamine　　　　　　 　　　　　　　　　　　　 0.95 parts by mass

(Full ether methylated melamine, solid content 100%, manufactured by Sanwa Chemical, brand name MW-30M, weight average degree of polymerization 1.3)

Mold release agent　　　　　　　　　　　　　　　　　　　 0.20 parts by mass

(Polydimethylsiloxane containing polyester-modified OH group, BYK-370, solid content 25%, manufactured by Big Chemie Japan)

Acid catalyst　　　　　　　　 　　　　　　　　　　 0.10 parts by mass

(p-toluenesulfonic acid, manufactured by Hitachi Kasei, brand name Dryer (registered trademark) 900, solid content 50%)

(Comparative Example 5)

Release film for producing ultra-thin ceramic green sheet in the same manner as in Example 1 except that the release agent of Example 1 was changed to one-end epoxy-modified polydimethylsiloxane (X22-173DX, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) Got it. The amount of PDMS shifted increased, perhaps because the interaction between the melamine-based compound and the epoxy group was weak.

(Comparative Example 6)

Release agent for producing ultra-thin layer ceramic green sheet in the same manner as in Example 1, except that the release agent of Example 1 was changed to hydroxy-modified polydimethylsiloxane (X22-170DX, manufactured by Shin-Etsu Chemical Co., Ltd.) at one end. I got a film. The amount of PDMS shifted was low and good, but the interaction between the carbinol group and the melamine-based compound was strong, and the peeling force became heavy because PDMS did not appear on the surface.

(Comparative Example 7)

Except having changed the coating liquid to the coating liquid of the following composition, it carried out similarly to Example 1, and obtained the release film for ultra-thin ceramic sheet production. The amount of PDMS shifted was low and good, but the interaction between the hydroxyl group and the melamine-based compound was strong, and the peeling force became heavy because PDMS did not appear on the surface.

Methyl ethyl ketone　　　　　　　　　　　　　　 49.32 parts by mass

Toluene　　　　　　　　　　　　　　　　　　 49.32 parts by mass

Melamine compound　　　　　　　　　　　　　　 1.25 parts by mass

(Imino-type methylated melamine, solid content 80%, manufactured by Sanwa Chemical, brand name MX-730, weight average degree of polymerization 2.4)

Mold release agent　　　　　　　　　　　　　　　　　　　 0.005 parts by mass

(Polyether-modified OH group-containing polydimethylsiloxane, BYK-377, 100% solid content, manufactured by Vicchemy Japan)

Acid catalyst　　　　　　　　　　　　　　　　　　　 0.10 parts by mass

(p-toluenesulfonic acid, manufactured by Hitachi Kasei, brand name Dryer (registered trademark) 900, solid content 50%)

(Comparative Example 8)

Except having changed the coating liquid to the coating liquid of the following composition, it carried out similarly to Example 1, and obtained the release film for ultra-thin ceramic sheet production. The amount of PDMS shifted was low and good, but the interaction between the hydroxyl group and the melamine-based compound was strong, and the peeling force became heavy because PDMS did not appear on the surface.

Methyl ethyl ketone　　　　　　　　　　　　　　 49.26 parts by mass

Toluene　　　　　　　　　　　　　　　　　　 49.26 parts by mass

Melamine compound　　　　　　　　　　　　　　 1.18 parts by mass

(Imino-type methylated melamine, solid content 80%, manufactured by Sanwa Chemical, brand name MX-730, weight average degree of polymerization 2.4)

Mold release agent　　　　　　　　 　　　　　　　　　　 0.20 parts by mass

(Polydimethylsiloxane containing polyester-modified OH group, BYK-370, solid content 25%, manufactured by Big Chemie Japan)

Acid catalyst　　　　　　　　　 　　　　　　　　　 0.10 parts by mass

(p-toluenesulfonic acid, manufactured by Hitachi Kasei, brand name Dryer (registered trademark) 900, solid content 50%)

[Table 1]

[Table 2]

According to the present invention, the surface of the release layer is smooth, and compared with the conventional release film for ceramic green sheet production, defects such as pinholes are not substantially generated in the ceramic green sheet, and the transition of polyorganosiloxane is reduced. It is possible to manufacture a ceramic green sheet of an ultra-thin layer of 0.2 to 1.0 μm as little as a small number.

Claims (6)

Using a biaxially oriented polyester film as a substrate, and having a release layer on at least one side of the substrate,
The release film for producing a ceramic green sheet, wherein the release layer is formed by curing a composition containing a release agent and a melamine-based compound, and the release agent contains a polyorganosiloxane containing a carboxyl group. The method of claim 1,
The melamine-based compound contains _{at least one selected from the group consisting of a methylol group or a (-CH 2} -OR) group (wherein R is an alkyl group having 1 to 4 carbon atoms) in one molecule, Release film for manufacturing ceramic green sheets. The method of claim 1,
The release film for producing a ceramic green sheet, wherein the melamine-based compound contains at least one selected from the group consisting of hexamethylol melamine or hexaalkoxymethyl melamine. The method of claim 1,
Has a surface layer A that does not contain substantially inorganic particles on at least one side of the substrate, and has the release layer directly or through another layer on the surface layer A,
The substrate has a surface layer B on the opposite side of the surface layer A, the surface layer B contains particles, at least some of the particles are silica particles and/or calcium carbonate particles, and the total content of particles relative to the mass of the surface layer B is 5000 Release film for manufacturing ceramic green sheet with ~15000ppm. A method for manufacturing a ceramic green sheet for forming a ceramic green sheet using the release film for manufacturing a ceramic green sheet according to any one of claims 1 to 4, wherein the formed ceramic green sheet has a thickness of 0.2 µm to 1.0 µm. Method of manufacturing a ceramic green sheet having. A method of manufacturing a ceramic capacitor employing the method of manufacturing a ceramic green sheet according to claim 5.