KR20200066680A - Release film for ceramic green sheet production - Google Patents

Abstract

[Task] By maintaining the high smoothness of the surface of the release layer, and also by lowering the force applied when peeling the ceramic green sheet from the release film and making it uniform, even ultra-thin products having a thickness of 1 µm or less can be applied to the ceramic green sheet at the time of peeling. Providing a release film for manufacturing a ceramic green sheet that does not cause damage.
[Solutions] A release film provided with a release layer on the surface layer A of a polyester film having a surface layer A substantially free of inorganic particles, wherein the release layer includes a binder a containing a cationic curable material and at least one release agent A release film for producing a ceramic green sheet, wherein the composition containing b is cured.

Description

Release film for ceramic green sheet production

The present invention relates to a release film for manufacturing a ceramic green sheet, and by suppressing the erosion of the release layer by an organic solvent during ceramic sheet processing or internal electrode printing, there is no fear of increasing the peeling force or impairing the uniformity of the peeling. It relates to a release film for manufacturing a ceramic green sheet.

A release film in which a release layer is laminated on a polyester film as a base material is conventionally used for forming ceramic green sheets, such as laminated ceramic capacitors and ceramic substrates. In recent years, with the downsizing and capacity increase of a multilayer ceramic capacitor, the thickness of the ceramic green sheet also tends to be thin. The ceramic green sheet is formed by coating and drying a slurry containing a ceramic component such as barium titanate and a binder resin on a release film. A laminated ceramic capacitor is manufactured by printing an electrode on a molded ceramic green sheet and peeling it from a release film, then laminating and pressing the ceramic green sheet, and applying a firing and external electrode. When the ceramic green sheet is molded on the surface of the release layer of the polyester film, the problem that microscopic projections on the surface of the release layer affects the molded ceramic green sheet, which tends to cause defects such as cratering and pinholes. there was. Therefore, a method for realizing the surface of a release layer having excellent flatness has been developed (for example, see Patent Document 1).

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

In recent years, it has been found that the surface of the release layer is smoothed by using a radically curable material that reacts under active energy ray irradiation. Moreover, it has been discovered that the silicone-based component contained in the release layer or a cured product thereof also has excellent peelability with a ceramic sheet (see, for example, Patent Document 2).

However, according to the method described in Patent Document 2, when processing under air, there is a problem that the surface of the release layer becomes defective due to the effect of oxygen inhibition due to the radical polymerization reaction. When the hardening of the surface of the release layer occurs, the release layer is eroded by an organic solvent during ceramic green sheet processing or internal electrode printing, and thus the peeling force is increased or the uniformity of the peeling is impaired. There was a fear of damage.

In addition, the radical polymerization reaction has a problem that curling is likely to occur in the release film because the curing shrinkage is large. When curling occurs in the release film, there is a fear that the transportability of the release film deteriorates or the electrode printing accuracy decreases, resulting in defects.

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

As a result of careful examination in view of the above circumstances, the present invention maintains high smoothness of the surface of the release layer, and also lowers the force applied when peeling the ceramic green sheet from the release film and makes it uniform, so that the thickness is 1 µm or less. It is to provide a release film for manufacturing a ceramic green sheet, which does not cause damage to the ceramic green sheet when peeling even an ultra-thin product.

That is, the present invention includes the following configurations.

1. A release film provided with a release layer on the surface layer A of a polyester film having a surface layer A substantially free of inorganic particles, wherein the release layer comprises a binder a containing a cationically curable material and one or more release agents b. A release film for manufacturing a ceramic green sheet comprising a cured composition.

2. The release film for manufacturing a ceramic green sheet according to the above 1, wherein the difference between the diiodomethane contact angle θ ₁ on the surface of the release layer and the diiodomethane contact angle θ _{2 on} the surface of the release layer after immersion in toluene is an absolute value of 3.0° or less.

3. A release film for producing a ceramic green sheet according to the first or second substrate, wherein at least one type of release agent b is a compound containing a silicone skeleton.

4. The release film for producing a ceramic green sheet according to any one of the above 1 to 3, wherein the binder a containing the cationically curable material contains 80% by mass or more of the total solids of the release layer.

5. The ceramic green sheet according to any one of the above 1 to 4, wherein the binder a containing the cationically curable material contains at least one compound selected from compounds having an alicyclic epoxy group in the molecule and compounds having an oxetane ring. Release film for manufacturing.

6. The release film for manufacturing a ceramic green sheet according to any one of the above 1 to 5, wherein at least one of the release agents b is a silicone containing an alicyclic epoxy group.

7. The release film for manufacturing a ceramic green sheet according to any one of the above 1 to 6, wherein the area surface average roughness (Sa) of the surface of the release layer is 7 nm or less, and the maximum protrusion height (P) is 100 nm or less.

8. A method for producing a ceramic green sheet having a thickness of 0.2 µm to 1.0 µm, the method for producing a ceramic green sheet using the release film for producing a ceramic green sheet according to any one of claims 1 to 7.

9. A manufacturing method of a ceramic capacitor employing the manufacturing method of the ceramic green sheet according to the eighth above.

According to the present invention, since there is no erosion of the release layer by the organic solvent during ceramic sheet processing or internal electrode printing, it is possible to provide a release film for manufacturing a ceramic green sheet without increasing the peeling force or fearing damage to the uniformity of peeling. It becomes possible.

The present inventors provided a release layer on one side by using a polyester film with a controlled surface roughness, and the release layer was made to contain a binder a containing a cationic curable material and at least one or more release agents b, thereby releasing It has been found that there is no fear that the layer will be eroded by an organic solvent, and a release film for manufacturing a ceramic green sheet having excellent peelability can be provided. In addition, it has been found that, because a cationically curable material with less curing shrinkage is used, curling is less likely to occur and a release film without fear of deteriorating electrode printing accuracy can be provided. Hereinafter, the present invention will be described in detail.

The release film for producing a ceramic green sheet of the present invention has a surface layer A substantially free of inorganic particles on at least one side of a polyester film, and on the surface layer A, a binder a containing at least a cationic curable substance and one or more release agents It is preferable that the release layer formed by curing the composition containing b is laminated. Since the cationically curable material is not inhibited from being cured by oxygen, there is no fear of curing failure of the surface of the release layer even in the air, and erosion of the release layer by an organic solvent can be suppressed. In addition, since the cationically curable material has a small curing shrinkage, curling is unlikely to occur, and there is no fear that the electrode printing precision is lowered. In addition, the cation-curable material used herein refers to a compound in which a cation generated in a reaction system becomes an active species and a curing reaction proceeds.

It is preferable that the release layer in this invention has little erosion by an organic solvent. The erosion of the release layer can be confirmed by evaluating the difference in the surface state of the release layer before and after immersing the release film in an organic solvent. As an organic solvent to be used for immersion, it is preferable to assume a ceramic green sheet manufacturing process and toluene used in a general ceramic slurry is used. As an example of a method for evaluating the surface state of the release layer, evaluation by contact angle is mentioned, and the smaller the change in the contact angle of the surface of the release layer before and after immersion in toluene, the more preferable.

The type of droplet used when measuring the contact angle is not particularly limited, and water, bromonaphthalene, ethylene glycol, etc. can be suitably used, respectively, but diiodomethane is used in which the difference in surface state of the release layer is more remarkable. It is most desirable to do.

When diiodomethane is used as a droplet used to measure the contact angle, the difference between the contact angle θ ₁ on the surface of the release layer and the contact angle θ _{2 on} the surface of the release layer after immersion of the release film in toluene at room temperature for 5 minutes ( The smaller the absolute value of θ ₁ -θ ₂ ) is, the better the solvent resistance of the surface of the release layer is. Specifically, the absolute value is preferably 3.0° or less, more preferably 2.0° or less, and most preferably 1.0° or less. If it is 3.0° or less, erosion of the release layer by the organic solvent during ceramic green sheet processing or internal electrode printing is suppressed, and it is preferable because there is no fear of increasing the peeling force or impairing the uniformity of the peeling. The smaller the value of the difference (θ ₁ -θ ₂ ) of the contact angle θ ₂ of the surface of the release layer after diiodomethane contact angle θ ₁ of the surface of the release layer and the release film was immersed in toluene at room temperature for 5 minutes, 0° Most preferred, but may be 0.05° or more as an absolute value.

(Polyester film)

In the present invention, the polyester constituting the polyester film used as the base material is not particularly limited, and a film formed of a polyester commonly used as a base material for a release film can be used. Preferably, the aromatic dibasic acid is used. It is preferable that it is a crystalline linear saturated polyester comprising a component and a diol component, for example, polyethylene terephthalate, polyethylene-2,6-naphthalate, polybutylene terephthalate, polytrimethylene terephthalate or constituent components of these resins The copolymer containing as the main component is more suitable, and a polyester film formed of 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 other dicarboxylic acid components and diol components may be copolymerized in a small amount, but in view of cost , It is preferably made of only terephthalic acid and ethylene glycol. Moreover, you may add well-known additives, such as an antioxidant, a light stabilizer, a ultraviolet absorber, and a crystallizing agent, within the range which does not inhibit the effect of the release film of this invention. It is preferable that the polyester film is a biaxially oriented polyester film for reasons such as the height of the elastic modulus in both directions.

The intrinsic viscosity of the polyethylene terephthalate film is preferably 0.50 to 0.70 dl/g, and more preferably 0.52 to 0.62 dl/g. When the intrinsic viscosity is 0.50 dl/g or more, it is preferable since there is not much breakage in the stretching step. On the contrary, when it is 0.70 dl/g or less, it is preferable since it has good cutability when cutting to a predetermined product width and does not cause dimensional defects. In addition, it is preferable that the raw material is vacuum dried sufficiently.

The manufacturing method of the polyester film in this invention is not specifically limited, A conventionally used method can be used. For example, it can be obtained by melting the polyester with an extruder, extruding it into a film, and 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 sequentially biaxially stretching a uniaxially stretched film in the longitudinal or transverse direction in the transverse or longitudinal direction, or by simultaneously biaxially stretching an unstretched film in the longitudinal and transverse directions. have.

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

The polyester film preferably has a thickness of 12 to 50 μm, more preferably 15 to 38 μm, and more preferably 19 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, and molding. On the other hand, if the thickness of the film is 50 µm or less, the amount of the film to be discarded after use is not extremely increased, which is preferable in reducing the environmental load.

Although the said polyester film base material may be a single layer or a multilayer of two or more layers, it is preferable to have the surface layer A which does not contain an inorganic particle substantially on at least one side. In the case of a laminated polyester film comprising a multi-layered structure of two or more layers, it is preferable to have a surface layer B that can contain inorganic particles or the like on the opposite side of the surface layer A that does not substantially contain inorganic particles. As a laminated structure, if the layer on the side to which the release layer is applied is A layer, the layer on the opposite side is B layer, and the core layer other than these is C layer, the layer configuration in the thickness direction is the release layer/A/B, or And a laminated structure such as a release layer/A/C/B. Naturally, the C layer may be composed of a plurality of layers. In addition, inorganic particles may not be included in the surface layer B. In that case, it is preferable to provide a coat layer containing at least inorganic particles and a binder on the surface layer B in order to impart slipperiness for winding the film in a roll shape.

In the polyester film base material in the present invention, it is preferable that the surface layer A forming the surface to which the release layer is applied does not substantially contain inorganic particles. At this time, the 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 pin holes or the like are unlikely to occur when forming an ultra-thin ceramic green sheet to be laminated. Although it can be said that the area surface roughness (Sa) of the surface layer A is smaller, it is preferable to be 0.1 nm or more. Here, when providing the anchor coat layer etc. which are mentioned later on the surface layer A, it is preferable not to contain an inorganic particle substantially in a coat layer, and the area surface average roughness (Sa) after lamination of a coat layer falls into the said range. desirable. In the present invention, the term "substantially free of inorganic particles" means that when the inorganic particles quantify inorganic elements by fluorescence X-ray analysis, 50 ppm or less, preferably 10 ppm or less, most preferably less than the detection limit It means the content to be. This is because, even if inorganic particles are not actively added to the film, contamination components derived from foreign substances or contamination attached to lines or devices in the raw material resin or film manufacturing process may be peeled off and mixed into the film. .

In the polyester film base material of the present invention, it is preferable that the surface layer B, which forms the opposite side of the surface to which the release layer is applied, contains inorganic particles from the viewpoint of slipperiness of the film and air easily falling out, In particular, it is preferable to use silica particles and/or calcium carbonate particles. It is preferable that the content of the inorganic particles contained is 5000 to 15000 ppm in the total amount of inorganic particles in the surface layer B. At this time, the area surface average roughness (Sa) of the film of the surface layer B is preferably in the range of 1 to 40 nm. More preferably, it is in the range of 5 to 35 nm. When the total of the silica particles and/or the calcium carbonate particles is 5000 ppm or more and Sa is 1 nm or more, when the film is wound up in a roll shape, air can be uniformly taken out, and the winding shape is good, and the flatness is good, resulting in an ultra-thin layer It becomes suitable for manufacture of ceramic green sheets. 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, aggregation of the lubricant is difficult to occur, and coarse projections are not generated. It is stable and desirable.

As the particles contained in the layer B, inert inorganic particles and/or heat-resistant organic particles may be used in addition to silica and/or calcium carbonate, but silica particles and/or calcium carbonate particles are more preferable from the viewpoint of transparency and cost. Preferably, 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, and benzoguanamine particles. Further, when using silica particles, porous colloidal silica is preferable, and when using calcium carbonate particles, hard calcium carbonate subjected to surface treatment with a polyacrylic acid-based polymer compound is preferable from the viewpoint of preventing the lubricant from falling off. Do.

The average particle diameter of the inorganic particles added to the surface layer B is preferably 0.1 µm or more and 2.0 µm or less, particularly preferably 0.5 µm or more and 1.0 µm or less. When the average particle diameter of the inorganic particles is 0.1 µm or more, the release film has good slipperiness and is preferable. In addition, if the average particle diameter is 2.0 µm or less, there is no fear of pinholes in the ceramic green sheet due to coarse particles on the surface of the release layer, which is preferable.

The surface layer B may contain two or more different particles of the material. Moreover, you may contain the thing of the same particle|grains with a different average particle diameter.

When the particle|grains are not included in the surface layer B, it is preferable to make it active in the coat layer containing particle|grains on the surface layer B. Although this coat layer is not specifically limited, It is preferable to provide it with an inline coat applied in film formation of a polyester film. When the surface layer B does not contain particles and has a coat layer including particles on the surface layer B, the surface of the coat layer is the same as the area surface average roughness (Sa) of the surface layer B described above, for the reason of the area surface average It is preferable that the roughness (Sa) is in the range of 1 to 40 nm. More preferably, it is in the range of 5 to 35 nm.

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

It is preferable that the thickness ratio of the surface layer A which is the layer provided on the side of the release layer is 20% or more and 50% or less of the total layer thickness of the base film. If it is 20% or more, it is difficult to receive the influence of particles contained in the surface layer B or the like from inside the film, and the region surface average roughness Sa is easy to satisfy the above range, and is preferable. When the thickness of the entire layer of the base film is 50% or less, the use ratio of the recycled raw material in the surface layer B can be increased, and the environmental load is small, which is preferable.

Further, from the viewpoint of economical efficiency, 50 to 90% by mass of film residue or recycled raw materials for plastic bottles can be used for layers other than the surface layer A (surface layer B or the intermediate layer C described above). Even in this case, it is preferable that the type, amount, particle diameter and area surface average roughness (Sa) of the lubricant contained in the layer B satisfy the above range.

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

(Release layer)

The release layer in the present invention is preferably formed by curing a composition containing at least a binder a containing a cationically curable substance and one or more release agents b (additives for imparting peelability). The binder a containing the cationically curable substance can be crosslinked to form a high modulus of elasticity or a coating film. By increasing the modulus of elasticity of the release layer, the release layer is not deformed and follows when peeling, which is preferable because there is no fear of damaging the ceramic green sheet.

To the extent that the function of the present invention is not impaired, it may be added in addition to the resin or additive. Here, in the present invention, it is conceivable that the structure of the compound is changing in the state after curing in the coating layer in the cationically curable material, but accurately expressing and describing the changed structure itself resulting from the cationically curable material Since it is very difficult, it is expressed as described above that "the release layer is formed by curing a composition containing a binder a containing a cationic curable material and one or more release agents b".

As the cationically curable material used for the release layer in the present invention, a general one can be used and is not particularly limited, but is preferably a vinyl ether compound or a cyclic ether compound, and among them, a compound containing an oxetane compound or an epoxy group It is preferred to use. Examples of the oxetane compound include aliphatic, aromatic, and alicyclic compounds. Examples of the compound containing an epoxy group include glycidyl ether type, glycidyl amine type, glycidyl ester type epoxy, and alicyclic epoxy. In particular, glycidyl ether type epoxy and alicyclic epoxy Is preferred, and it is most preferable to use an alicyclic epoxy from the viewpoint of reactivity. Examples of the glycidyl ether-type epoxy compound include aromatic glycidyl ethers represented by bisphenol-type epoxy resins or cresol novolac-type epoxy resins, and aliphatic glycides represented by hydrogenated A-type glycidyl ethers and butyl glycidyl ethers. And diether. Examples of the alicyclic epoxy include an ester skeleton, a dicyclopentadiene skeleton, a fluorene skeleton, and an ε-caprolactone skeleton, and may have other skeletons.

As said alicyclic epoxy compound, what is marketed can also be used. Examples of commercial products include Cyclomer (registered trademark) M100, Celloxide (registered trademark) 2000 (above, manufactured by Daicel, monofunctional), and Celoxide (registered trademark) 2021P, 2081 (above, manufactured by Daicel, bifunctional), Epolyd (trademark) GT401 (made by Daicel, tetrafunctional), EHPE (registered trademark) 3150 (made by Daicel, polyfunctional), etc. are mentioned.

A commercially available thing can also be used as said oxetane compound. As examples of commercial products, Aaron Oxetane (registered trademark) OXT-101, 212 (above, manufactured by Doa Gosei Co., monofunctional) OXT221, OXT-121 (above, manufactured by Doa Gosei Corporation, bifunctional), ETERNACOL (registered trademark) EHO , OXMA (above, manufactured by Ube Kosan Co., monofunctional) OXTP, OXBP (above, manufactured by Ube Kosan Co., bifunctional), and the like.

The number of cationic curable functional groups of the cationic curable material is not particularly limited, and may be one, or two or more. In order to increase the crosslinking density of the release layer and improve the solvent resistance, it is preferable that the number of functional groups is two or more. Moreover, as an introduction position of a cation-curable functional group, you may be in an arbitrary position in a terminal, a side chain, and a straight chain. In addition, the cationic curable functional group shown here refers to a functional group that can be a crosslinking point in a cationic curing reaction.

Moreover, you may use 1 type or the mixture of 2 or more types of the said cationically curable substance. Although not particularly limited, the use of two or more types of cationically curable materials is preferable because the polymer network chain after the reaction becomes complicated and the crosslinking density becomes high, and erosion of the release layer by the organic solvent can be suppressed.

When using two or more types of cationic curable materials, it is not particularly limited, but it is preferable to use two types of cationic curable materials having different functional groups. By using a different functional group number, it is possible to effectively form a polymer network and form a release layer having a high crosslink density. For example, by mixing a cationic curable material having two functional groups and a polyfunctional or cationic curable material having three or more functional groups, a linear polymer is formed of a bifunctional cationic curable material, and a trifunctional part of the polymer chain Since the crosslinked structure of the polymer chains can be achieved by entering the above-mentioned cationically curable material, the crosslinking density can be improved.

When two or more types of cationically curable materials are used, the optimum ratio is preferably 0.1 mass parts or more and 50 mass parts or less of the other curable material, more preferably 100 mass parts of one curable material, and more preferably Is 0.5 part by mass or more and 20 parts by mass or less, and most preferably 1 part by mass or more and 10 parts by mass or less. When one curable substance is 0.1 part by mass or more, the amount introduced into the crosslinked structure of the other curable substance is not extremely reduced, and the effect of increasing the crosslinking density can be sufficiently obtained, which is preferable. When one curable substance is used in an amount of 50 parts by mass or less, the crosslinking structure of each curable substance is not predominant, and a complex polymer net chain obtained by mixing is formed, which is preferable because an effect of increasing crosslinking density is obtained.

It is preferable that the release layer in the present invention increases the crosslinking density in order to suppress the erosion of the release layer by an organic solvent. For this reason, any of polymers, oligomers, and monomers may be used as the cationically curable material, but the use of monomers is particularly preferable because the number of crosslinking points per mass increases and the crosslinking density can be increased.

In the release layer in the present invention, it is preferable that the cationically curable substance is contained in an amount of 80% by mass or more and 99.9% or less, more preferably 90% by mass or more and 99.9% or less, more preferably Is 95% by mass or more and 99.9% or less. The cationically curable material is preferred because it contains 80% by mass or more of a cationic polymerization reaction, so that a high crosslinking density can be obtained and erosion of the release layer by an organic solvent can be suppressed. At this time, as the solid content of the entire release layer, the acid generator decomposes under the drying process or active energy ray irradiation, and it is difficult to accurately calculate the trace mass remaining in the release phase. It is expressed as a value.

(Acid generator)

In order to advance the cationic polymerization reaction in the release layer in the present invention, it is preferable to use an acid generator. The acid generator to be used is not particularly limited, and a common one is used, but it is preferable because the amount of heat during processing can be suppressed by using a photoacid generator that generates acid under active energy ray irradiation. Even by using a general acid such as sulfonic acid or carboxylic acid, a release layer having a high crosslinking density that suppresses the erosion of organic solvents can be obtained, but because a high processing temperature is required, heat shrinkage of the fabric or lowering of smoothness may result. There is a fear that the surface of the release layer will become rough. In addition, although a metal salt-based, phosphoric acid-ester-based, acid-blocking block type acid generator can also be used, it is most preferable from the viewpoint of heat during processing to use a photoacid generator for the reasons described above.

As a photoacid generator, it is suitable from the viewpoint of reactivity to use a salt containing an onium ion and a non-nucleophilic anion. Further, an organometallic complex represented by the iron arene complex or a carbocation salt represented by trophylium may be used, or an anthracene derivative or a phenol substituted with an electron withdrawing group, for example, pentafluorophenol may be used.

When the salt containing the onium ion and the non-nucleophilic anion is used as a photoacid generator, for example, iodonium, sulfonium, and ammonium can be used as the onium ion. As the organic group of onium ions, triaryl, diaryl (monoalkyl), monoaryl (dialkyl), and trialkyl may be used, benzophenone or 9-fluorene may be introduced, or other organic groups may be used. . As the non-nucleophilic anion, it is suitable to use hexafluorophosphorate, hexafluoroantimonate, hexafluoroborate, tetra(pentafluorophenyl) borate. Further, an anion obtained by substituting a tetra(pentafluorophenyl) gallium ion or some of the fluorine anions with a perfluoroalkyl group or an organic group may be used, or other anion components may be used.

When using the photoacid generator, it is also possible to increase the reactivity of the polymerization reaction by adding a sensitizer and further suppress the erosion of the release layer by the organic solvent. Although a sensitizer is not particularly limited and a common one is used, anthracene derivatives and naphthalene derivatives are suitable. You may use 1 type, or 2 or more types of sensitizers.

It is preferable that the amount of the photoacid generator added to the coating solution is 0.1 to 10 parts by mass based on the total mass of the binder a and the release agent b containing the cationically curable material contained in the release layer. More preferably, it is 0.5 to 8 parts by mass. More preferably, it is 1 to 5 parts by mass. When the amount is 0.1 parts by mass or more, the amount of acid generated is insufficient, and there is no possibility of insufficient curing, which is preferable. Moreover, it is preferable because the amount of the generated acid is an appropriate amount by setting the amount to 10 parts by mass or less, and the amount of acid migration to the ceramic green sheet to be molded can be suppressed.

It is preferable that the addition amount of a sensitizer is 0.1 to 5 times as a mass with respect to a photoacid generator. More preferably, it is preferably 0.1 to 2 times. If it is larger than 0.1 times, it is preferable because there is no fear that a sufficient sensitizing effect cannot be obtained. If it is less than 5 times, the absorption of the active energy rays of the photoacid generator is inhibited, and there is no concern that sufficient acid is not generated, which is preferable.

(Release agent b)

As the release agent b (an additive for imparting releasability) used in the release layer in the present invention, silicone-based additives, non-silicone-based additives such as long-chain alkyl and fluorine-based additives, etc. can be used, but silicone-based additives are used from the viewpoint of peelability. It is desirable to do.

The silicone-based additive is a material based on a polyorganosiloxane having an organic group in a siloxane bond, and is not particularly limited and can be used in general as long as the effect of the present invention is obtained. Acrylic resin, alkyd resin, etc. which have a polyorganosiloxane in a side chain can also be used. Among the polyorganosiloxanes, polydialkylsiloxanes can be suitably used, and among them, it is more preferable to use polydimethylsiloxane, and it is more preferable to have a functional group in a part of polydimethylsiloxane. Having a functional group is preferred because the interaction between the cationically curable substance and hydrogen bonds is likely to occur, making it difficult to migrate to the ceramic green sheet.

Although it does not specifically limit as a functional group introduce|transduced into polydimethylsiloxane, It may be a reactive functional group or a non-reactive functional group. In addition, the functional group may be introduced at one end of polydimethylsiloxane, and may be both ends or side chains. In addition, one or more positions may be introduced.

As the reactive functional groups introduced into the polydimethylsiloxane, cyclic ether groups, hydroxyl groups, mercapto groups, carboxyl groups, methacryloyl groups, acryloyl groups, and the like can be used. Although not particularly limited, it is preferable to use a cyclic ether group, and in particular, if it contains a cationic curable functional group, such as a glycidyl ether group, an alicyclic epoxy group, or an oxetane ring, it is introduced into the crosslinked structure of the cationic curable material, It is preferable because the transition to the ceramic green sheet becomes difficult. Especially, when it contains an alicyclic epoxy group, since compatibility with a binder component is also excellent, peelability is easy to express, and it is most preferable. As the non-reactive functional group, a polyether group, an alkyl group, a fluoroalkyl group, a long chain alkyl group, an ester group, an amide group, a phenyl group, etc. can be used.

When describing a preferred silicone-based additive in more detail, it is preferable to use a silicone-based additive having a cationically curable reactor, and more preferably to use a silicone-based additive having an epoxy group. As an epoxy group, it is most suitable to use a silicone-based additive having an alicyclic epoxy group. More specifically, when the structure of the silicone-based additive having an alicyclic epoxy group is described, examples thereof include polydimethylsiloxane containing an alicyclic epoxy group or polydimethylsiloxane and an acrylic resin having an alicyclic epoxy group on the side chain.

The silicone-based additive used in the present invention is not particularly limited and an existing one can be used. For example, as a commercial product of silicone having a reactive functional group, X-22-170DX, X-22-3710, X-22-176DX, X-22-167B (above, manufactured by Shin-Etsu Chemical Co., Ltd.), BYK- Examples include UV3500, BYK-UV3505, and BYK-UV3575 (above, manufactured by Big Chem. Japan). Examples of commercial products of the silicone-based additive having a cationically curable functional group include X-22-173BX, X-22-173DX, X-22-4741, and X-22-9002 (above, manufactured by Shin-Etsu Chemical Co., Ltd.). , Among them, commercial products of silicone having an alicyclic epoxy group, X-22-169B, KF-102, X-62-7629, X62-7660, X-62-7622 (above, manufactured by Shin-Etsu Chemical Co., Ltd.), UV9300, UV9315, UV9430 (above, Momentive Performance Materials, Inc.), Silicoris (registered trademark) UV Poly200, 201, 215 (above, Arakawa Kagaku Kogyo Co., Ltd.) and the like can be suitably used.

The fluorine-based additive is not particularly limited, and an existing one can be used. For example, those having a perfluoro group or those having a perfluoroether group can be suitably used. Examples of commercial products include Megapak (registered trademark) (manufactured by DIC), Optull (registered trademark) (manufactured by Daikin Kogyo), FCLEAR (registered trademark) (Kanto Denka Kogyo).

As the long-chain alkyl-based additive, a long-chain alkyl-modified resin can be used, and it is preferable to have an alkyl group having 8 to 20 carbon atoms in side chains such as polyvinyl alcohol and acrylic resin. Moreover, it is a polymer which has a (meth)acrylic acid ester as a main repeating unit, and a copolymer containing a long chain alkyl group having 8 to 20 carbon atoms in the transesterified portion can also be suitably used. Examples of commercially available products include Fatigue Day (registered trademark) 1010, Fatigue Day (registered trademark) 1050, Fatigue Day (registered trademark) 1070, etc. (above, Lion Specialty Chemical Company), Tespine (registered trademark) 305, Tespine (Registered trademark) 314 (above, manufactured by Hitachi Kasei) and the like.

Further, two or more types of the above-mentioned release agents may be mixed and used, but at least one type of release agent is preferably a silicone-based additive, more preferably a silicone having a cationically curable functional group, and most preferably a silicone having an alicyclic epoxy group. Do. At least one type of release agent is a silicone-based additive, and is preferable because it is a release layer excellent in peelability.

It is preferable that the release agent b in this invention contains 0.1 mass% or more and 20 mass% or less with respect to the solid content of the whole release layer. More preferably, it is 0.5 mass% or more, 10 mass% or less, and still more preferably, it is 0.5 mass% or more and 5 mass% or less. It is preferable that releasability is imparted by increasing the amount to more than 0.1% by mass and there is no fear that the peelability of the ceramic green sheet is deteriorated. It is preferable to reduce it to 20% by mass or less because the decrease in the intermolecular interaction with the cationically curable substance is suppressed, and the possibility of causing migration to the ceramic green sheet is eliminated. At this time, the solid content of the entire release layer is decomposed under the drying process or active energy ray irradiation, and it is difficult to accurately calculate the trace mass remaining in the release phase, so the total solid content of the binder component and the release agent is It is expressed as a value.

The release layer in the present invention may contain particles having a particle diameter of 1 µm or less, but from the viewpoint of pinhole generation, protrusions such as particles are formed except for a very small amount of impurities unintentionally mixed. It is preferable not to contain, and it is particularly preferable that inorganic particles or organic particles are not contained, regardless of their solubility and non-solubility, regardless of their type, particle size, or shape.

To the release layer in the present invention, an additive such as an adhesion improving agent or an antistatic agent may be added 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 pretreat the polyester film surface, such as anchor coat, corona treatment, plasma treatment, atmospheric pressure plasma treatment, etc., before providing the release coating layer.

(Features of release layer)

In the present invention, the thickness of the release layer may be set depending on the purpose of use, and is not particularly limited. Preferably, the thickness of the release coating layer after curing is preferably in the range of 0.01 to 1.0 µm, more preferably , 0.01 to 0.5㎛, more preferably 0.01 to 0.2㎛, most preferably 0.02 to 0.1㎛. When the thickness of the release layer is larger than 0.01 µm, it is preferable because sufficient peeling performance can be obtained. Moreover, since it is difficult to generate|occur|produce a defect of curl when it is 1.0 micrometer or less, since there is no increase in the amount of active energy ray irradiation and heat required for hardening, there is no possibility of a decrease in processing speed, and it is also preferable from an economical point of view.

The surface of the release layer of the release film of the present invention is preferably flat and preferably has a region surface average roughness (Sa) of 7 nm or less so as not to cause defects in the ceramic green sheet coated and molded thereon. Further, it is more preferable that Sa sa satisfies, and the maximum protrusion height P of the release layer surface is 100 nm or less. It is particularly preferable if the area surface average roughness (Sa) is 5 nm or less and the maximum projection height is 80 nm or less. When the surface roughness of the region is 7 nm or less and the maximum protrusion height is 100 nm or less, defects such as pinholes do not occur at the time of forming the ceramic green sheet, and the yield is good, which is preferable. The smaller the area surface average roughness (Sa), the more preferable it may be, but may be 0.1 nm or more, or 0.3 nm or more. It can be said that the smaller the maximum projection height P is, the more preferable it is, but it may be 1 nm or more, or 3 nm or more.

It is preferable that the release force of the release film of this invention when peeling a ceramic green sheet is 0.5 mN/mm<2> or more and 3.0 mN/mm<3> or less. More preferably, it is 0.8 mN/mm 2 or more and 2.5 mN/mm 2 or less. When the peeling force is 0.5 mN/mm 2 or more, the peeling force is too light, so that there is no fear of floating the ceramic green sheet during conveyance, which is preferable. When the peeling force is 3.0 mN/mm or less, it is preferable that there is no fear of damaging the ceramic green sheet upon peeling.

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

(How to form a release layer)

In the present invention, the method of forming the release layer is not particularly limited, and a coating solution obtained by dissolving or dispersing a composition containing a release resin or the like is developed on one surface of the polyester film of the substrate by coating or the like, and a solvent or the like is developed. After drying, drying and heating, a method of curing by irradiation of active energy rays or heat is used.

When curing using a photoacid generator, the heating temperature is preferably 50°C or higher and 110°C or lower, and more preferably 60°C or higher and 100°C or lower. The heating time is preferably 30 seconds or less, and more preferably 20 seconds or less. When the temperature is 110°C or lower, thermal load on the film can be suppressed, and appearance defects such as heat shrinkage of the film are less likely to occur, and the possibility of causing thickness unevenness of the ceramic green sheet is small, which is preferable. When the temperature is 100° C. or less, the thermal load on the film further decreases, and processing is possible without impairing the flatness of the film, which is particularly preferable since the possibility of causing unevenness in the thickness of the ceramic green sheet is further reduced. If it is higher than 50°C, drying of the diluting solvent used when applying is sufficient, and there is no possibility of contamination of the process, which is preferable.

As an active energy ray used for reacting a cationically curable substance using a photoacid generator, ultraviolet rays, electron beams, X rays, and the like can be used, but ultraviolet rays are preferred because they are easy to use. The amount of ultraviolet light to be irradiated is preferably 10 to 1000 mJ/cm 2 as an integrated light amount, more preferably 15 to 500 mJ/cm 2, and even more preferably 15 to 100 mJ/cm 2. It is preferable to set it to 10 mJ/cm 2 or more because curing of the resin sufficiently proceeds. Since the speed at the time of processing can be improved by setting it to 1000 mJ/cm 2 or less, a release film can be produced economically, which is 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 making the surface tension as above, the wettability after coating can be improved, and the unevenness of the surface of the coated film after drying can be reduced.

In this invention, although it does not specifically limit to the coating liquid at the time of apply|coating a release coating layer, It is preferable to add a solvent with a boiling point of 90 degreeC or more. By adding a solvent having a boiling point of 90°C or higher, the dolby during drying can be prevented, the coated film can be leveled, and the smoothness of the surface of the coated film after drying can be improved. It is preferable to add about 10 to 80 mass% with respect to the whole coating liquid as the addition amount.

As a coating method of the said coating liquid, arbitrary well-known coating methods can be applied, For example, the roll coating method, such as a gravure coating method or the reverse coating method, the bar coating method, such as a wire bar, die coating method, spray coating method. , Air knife coating method, etc., can be used.

Example

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

(Intrinsic viscosity of polyester resin (dl/g))

In accordance with JIS K 7367-5, measurement was performed at 30°C using a mixed solvent of phenol (60 mass%) and 1,1,2,2-tetrachloroethane (40 mass%) as a solvent.

(Base film thickness)

Using a millitron (electronic micro-indicator), the film to be measured is cut out of 4 square samples with 5 cm on one side from any 4 locations, and each 5 points (20 points in total) is measured per sheet to give an average value of thickness. did.

(Film thickness of release layer)

When the release film was cut to an arbitrary size and taken, the cross section of the film was observed with a transmission electron microscope and the calculated value was taken as the release layer thickness.

(Surface roughness)

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

(Measuring conditions)

Measurement mode: WAVE mode

· Objective lens: 10 times

0.5×Tube lens

Measurement area 936㎛×702㎛

(Interpretation conditions)

· Surface correction: 4th correction

·Interpolation processing: Full interpolation

(Contact angle)

Diiodomethane (droplet 0.9 μL) on the release surface of the release film left standing using a contact angle meter (Kyowa Gaimen Chemical Co., Ltd. DM-701, manufactured under the conditions of 25°C and 50% RH) ) Was prepared, and the contact angle was measured. As the contact angle, a contact angle of 30 seconds after being dropped onto the release film was adopted, and an average value of the values measured 5 times was employed.

(Contact angle after toluene immersion)

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

(Evaluation of contact angle change)

When the di-iodo-methane contact angle of toluene the initial contact angle of the di-iodo-methane of the release layer surface θ _1, toluene release layer surface before immersion after immersion measured by the method as θ _2, θ ₁ -θ ₂ of the absolute value The value of was used as the value of the change in the contact angle before and after immersion in toluene. The change in the contact angle was evaluated based on the following criteria.

◎: |θ ₁ -θ ₂ |<1.0°

○: 1.0°≤|θ ₁ -θ ₂ |<2.0°

△: 2.0°≤|θ ₁ -θ ₂ |≤3.0°

×: |θ ₁ -θ ₂ |>3.0°

(Pin hole evaluation of ceramic green sheet)

Below, the composition containing the material was stirred and mixed, and dispersed for 30 minutes using a bead mill having zirconia beads having a diameter of 0.5 mm as a dispersing material to obtain a ceramic slurry.

toluene 76.3 parts by mass

ethanol 76.3 parts by mass

Barium titanate (HPBT-1 manufactured by Fuji Titanium) 35.0 parts by mass

Polyvinyl butyral 3.5 parts by mass

(Sekisui Chemical Co., Ltd. S-REC (registered trademark) BM-S)

DOP (dioctyl phthalate) 1.8 parts by mass

Subsequently, the release film of the obtained release film sample was coated with an applicator so that the slurry after drying had a thickness of 0.8 µm, and after drying at 90° C. for 1 minute, the release film was peeled off to obtain a ceramic green sheet.

In the center area in the film width direction of the obtained ceramic green sheet, light was emitted from the opposite side of the coated surface of the ceramic slurry in the range of 25 cm 2, and the occurrence of pinholes through which light was seen was observed, and visually judged according to the following criteria. . The measurement was performed 5 times, and the average value was employed.

◎: No pin hole occurrence

○: Almost no occurrence of pin holes (Standard: No more than 2 pin holes per measurement area)

△: There is a pinhole occurrence (Standard: 5 or less pinholes per measurement area)

×: There are many occurrences of pinholes

(Evaluation of peelability of ceramic green sheet)

Below, the composition containing the material was stirred and mixed, and dispersed for 60 minutes using a bead mill having zirconia beads having a diameter of 0.5 mm as a dispersing material to obtain a ceramic slurry.

toluene 38.3 parts by mass

ethanol 38.3 parts by mass

Barium titanate (HPBT-1 manufactured by Fuji Titanium) 64.8 parts by mass

Polyvinyl butyral 6.5 parts by mass

(Sekisui Chemical Co., Ltd. S-REK (registered trademark) BM-S)

DOP (dioctyl phthalate) 3.3 parts by mass

Subsequently, an applied surface was applied to the release surface of the obtained release film sample so that the slurry after drying was 10 μm thick, dried at 90° C. for 2 minutes, and the ceramic green sheet was molded on the release film. After removing the release film having the obtained ceramic green sheet using a static eliminator (manufactured by Keyence, SJ-F020), it was peeled to a width of 30 mm using a high-speed peeling tester (Tester Sangyo Co., Ltd., TE-701). Peeling was performed at an angle of 90 degrees and a peeling rate of 10 m/min. Peeling fixed the ceramic green sheet surface and peeled it in the direction of pulling the release film surface. The stress at the time of peeling at this time was measured and referred to as peeling force.

(Curl evaluation of release film)

The release film sample was cut to a size of 10 cm×10 cm, and heat treatment was performed for 15 minutes at 100° C. in a hot air oven so that tension was not applied to the release film. Then, after taking out from the oven and cooling to room temperature, a release film sample was placed on a glass plate so that the release surface was on top. At this time, the height from the glass plate to each corner apex was measured, and curlability was evaluated based on the following judgment criteria.

◎: the total sum of each corner is 1 mm or less

(Circle): The sum total of each corner part is larger than 1 mm, and is 3 mm or less.

(Triangle|delta): The sum total of each corner part is more than 3 mm, and is 10 mm or less.

X: The total curl of each corner is greater than 10 mm.

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

As the esterification reaction apparatus, a continuous esterification reaction apparatus including a three-stage complete mixing tank having a stirring device, a condenser, a raw material inlet and a product outlet was used. TPA (terephthalic acid) was 2 ton/hour, EG (ethylene glycol) was 2 mol per 1 mol of TPA, antimony trioxide was produced, and the amount of Sb atom was 160 ppm for PET. The first esterification reaction was continuously supplied to the can, and reacted at 255° C. at normal residence time of 4 hours under normal pressure. Subsequently, 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 EG that is distilled and removed from the first esterification reaction can in the second esterification reaction can is produced in PET. 8% by weight, and further includes EG solution containing magnesium acetate tetrachloride in an amount of Mg atoms of 65 ppm with respect to the produced PET, and TMPA (trimethyl phosphate) in an amount of 40 ppm with respect to the produced PET. The EG solution was added and reacted at 260°C under normal pressure for an average residence time of 1 hour. Subsequently, 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 a high pressure disperser (manufactured by Nippon Seiki Co., Ltd.) is used at a pressure of 39 kPa (400 kg/cm 2 ). 0.2 mass% of porous colloidal silica having an average particle diameter of 0.9 µm after a dispersion treatment of 5 passes with an average number of treatments and 0.4 mass percent of synthetic calcium carbonate having an average particle diameter of 0.6 µm with ammonium salt of polyacrylic acid adhering 1 mass% per calcium carbonate. Was reacted at 260° C. at an average residence time of 0.5 hours at normal pressure while adding as 10% EG slurry, respectively. The esterification reaction product produced in the third esterification reaction can is continuously supplied to a three-stage continuous polycondensation reaction apparatus to perform polycondensation, and the stainless steel fibers having a 95% cut diameter of 20 µm are filtered through a sintered filter. After performing, ultrafiltration was performed and extruded into water, and after cooling, cut into chips to obtain 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 production of the PET chip, a PET chip having an intrinsic viscosity of 0.62 dl/g containing no inorganic particles such as calcium carbonate or silica was obtained (hereinafter abbreviated as PET(II)).

(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 extruder, and sintered a stainless steel fiber having a 95% cut diameter of 15 μm and a filter having a 95% cut diameter of 15 μm. Two stages of the filter sintered with the phosphorus stainless steel particles are filtered, joined in the feed block, and the PET(I) is the surface layer B (half-release side layer) and the PET(II) is the surface layer A (release side layer). Unstretched polyethylene terephthalate having an intrinsic viscosity of 0.59 dl/g by laminating as possible, extruding (casting) in a sheet form at a speed of 45 m/min, and electrostatically contacting and cooling on a casting drum at 30° C. by an electrostatic adhesion method. Sheets were obtained. The layer ratio was adjusted such that PET(I)/PET(II)=60%/40% by calculating the discharge amount of each extruder. Subsequently, 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 roll temperature of 80 degreeC. Then, it induced by a tenter, and stretched 4.2 times in the horizontal direction at 140 degreeC. Next, in a heat setting zone, heat treatment was performed at 210°C. Thereafter, a relaxation treatment of 2.3% was performed at 170°C in the horizontal 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 configuration and stretching conditions similar to those of the laminated film X1 were not changed, and the thickness was adjusted by changing the speed at casting to obtain a biaxially stretched polyethylene terephthalate film X2 having a thickness of 25 μm. Sa of the obtained surface layer A of the film X2 was 3 nm, and Sa of the surface layer B was 29 nm.

(Laminated film X3)

As the laminated film X3, E5101 (Toyobo Ester (registered trademark) film, manufactured by Toyobo) having a thickness of 25 μm was used. E5101 has a structure containing inorganic particles in a film. Sa of the surface layer A of the laminated film X3 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 coated with a wire bar so that the release layer film thickness after drying was 50 nm, and after drying at 90° C. for 15 seconds, ultraviolet rays having an accumulated light amount of 70 mJ/cm 2 were ultraviolet. The release film for manufacturing ultra-thin ceramic green sheets was obtained by irradiation with an irradiator (made by Heraeus, LC6B, H valve). A ceramic slurry was coated on the resulting release film, and the surface roughness, release properties, change in contact angle after toluene immersion, pinholes, curls, and the like were evaluated, and good evaluation results were obtained.

Methyl ethyl ketone 49.43 parts by mass

toluene 49.43 parts by mass

Binder comprising a cationic curable material: 3',4'-epoxycyclohexylmethyl3,4-epoxycyclohexanecarboxylate 0.90 parts by mass

(Product name: Celloxide (registered trademark) 2021P, manufactured by Daicel, solid content 100% by mass, bifunctional)

Mold release agent b: polydimethylsiloxane containing an alicyclic epoxy group

0.10 parts by mass

(Product name, UV Poly215, manufactured by Arakawa Kagaku High School, 100% solids)

Acid generator: Boron-based cationic curing UV catalyst 0.26 parts by mass

(Product name: UV CATA211, 19% by mass of active ingredient, manufactured by Arakawa Kagaku Kogyo Co., Ltd.)

(Example 2)

A release film for manufacturing an ultra-thin layered ceramic green sheet was obtained in the same manner as in Example 1 except that the composition was changed to a coating solution having the composition shown below.

Methyl ethyl ketone 49.43 parts by mass

toluene 49.43 parts by mass

Binder comprising a cationic curable material a:

Celloxide(registered trademark) 2021P 0.86 parts by mass

Tetrabutanecarboxylic acid tetra(3,4-epoxycyclohexylmethyl modification

ε-caprolactone 0.04 parts by mass

(Product name: EPOLID (registered trademark) GT401, manufactured by Daicel, solid content 100%, tetrafunctional)

Mold release agent b: UV Poly215 0.10 parts by mass

Acid generator: UV CATA211 (active ingredient 19% by mass)

0.26 parts by mass

(Example 3)

A release film for manufacturing an ultra-thin layered ceramic green sheet was obtained in the same manner as in Example 1 except that the composition was changed to a coating solution having the composition shown below.

(Application amount 3)

Methyl ethyl ketone 49.43 parts by mass

toluene 49.43 parts by mass

Binder comprising a cationic curable material a:

Celloxide(registered trademark) 2021P 0.63 parts by mass

EPOLID (registered trademark) GT401 0.27 parts by mass

Mold release agent b: UV Poly215 0.10 parts by mass

Acid generator: UV CATA211 (active ingredient 19% by mass)

0.26 parts by mass

(Example 4)

A release film for manufacturing an ultra-thin layered ceramic green sheet was obtained in the same manner as in Example 1 except that the composition was changed to a coating solution having the composition shown below.

Methyl ethyl ketone 49.43 parts by mass

toluene 49.43 parts by mass

Binder comprising a cationic curable material a:

Celloxide(registered trademark) 2021P 0.45 parts by mass

EPOLID (registered trademark) GT401 0.45 parts by mass

Mold release agent b: UV Poly215 0.10 parts by mass

Acid generator: UV CATA211 (active ingredient 19% by mass)

0.26 parts by mass

(Example 5)

A release film for manufacturing an ultra-thin layered ceramic green sheet was obtained in the same manner as in Example 1 except that the composition was changed to a coating solution having the composition shown below.

Methyl ethyl ketone 49.43 parts by mass

toluene 49.43 parts by mass

Binder comprising a cationic curable material a:

Celloxide(registered trademark) 2021P 0.86 parts by mass

2-ethylhexyloxetane 0.04 parts by mass

(Product name: Aaron oxetane (registered trademark) OXT-221, manufactured by Toa Gosei Co., 100% by mass of solid content, bifunctional)

Mold release agent b: UV Poly215 0.10 parts by mass

Acid generator: UV CATA211 (active ingredient 19% by mass)

0.26 parts by mass

(Example 6)

A release film for manufacturing an ultra-thin layered ceramic green sheet was obtained in the same manner as in Example 1 except that the composition was changed to a coating solution having the composition shown below.

Methyl ethyl ketone 49.43 parts by mass

toluene 49.43 parts by mass

Binder comprising a cationic curable material a:

EPOLID (registered trademark) GT401 0.90 parts by mass

Mold release agent b: UV Poly215 0.10 parts by mass

Acid generator: UV CATA211 (active ingredient 19% by mass)

0.26 parts by mass

(Example 7)

A release film for manufacturing an ultra-thin layered ceramic green sheet was obtained in the same manner as in Example 1 except that the composition was changed to a coating solution having the composition shown below.

Methyl ethyl ketone 49.43 parts by mass

toluene 49.43 parts by mass

Binder comprising a cationic curable material a:

Polyfunctional alicyclic epoxy group-containing polymer 0.90 parts by mass

(Product name: EHPE (registered trademark) 3150, manufactured by Daicel, solid content 100% by mass, polyfunctional)

Mold release agent b: UV Poly215 0.10 parts by mass

Photoacid generator: hexafluoroantimonate triarylsulfonium salt

0.10 parts by mass

(Product name: CPI (registered trademark) 101A, active ingredient 50% by mass, acid-apro company)

(Example 8)

A release film for manufacturing an ultra-thin layered ceramic green sheet was obtained in the same manner as in Example 1 except that the composition was changed to a coating solution having the composition shown below.

Methyl ethyl ketone 49.43 parts by mass

toluene 49.43 parts by mass

Binder comprising a cationic curable material a:

Celloxide(registered trademark) 2021P 0.90 parts by mass

Mold release agent b: UV Poly215 0.10 parts by mass

Photoacid generator: hexafluoroantimonate triarylsulfonium salt

0.10 parts by mass

(Product name: CPI (registered trademark) 101A, active ingredient 50% by mass, acid-Apro)

(Example 9)

A release film for manufacturing an ultra-thin layered ceramic green sheet was obtained in the same manner as in Example 1 except that the composition was changed to a coating solution having the composition shown below.

Methyl ethyl ketone 49.43 parts by mass

toluene 49.43 parts by mass

Binder comprising a cationic curable material a:

Celloxide(registered trademark) 2021P 0.90 parts by mass

Mold release agent b: UV Poly215 0.05 parts by mass

Acryloyl group-containing polyether-modified polydimethylsiloxane

0.05 parts by mass

(Product name: BYK-UV3500, manufactured by Big Chemie Japan, 100% solids)

Acid generator: UV CATA211 (active ingredient 19% by mass)

0.26 parts by mass

(Example 10)

A release film for manufacturing an ultra-thin layered ceramic green sheet was obtained in the same manner as in Example 1, except that the release agent b of Example 1 was changed to a release agent containing a long chain alkyl group obtained as follows.

(Long-chain alkyl group-containing release agent manufacturing method)

The mixture was mixed at a ratio of 95 mol% of stearyl acrylate and 5 mol% of hydroxyethyl (meth)acrylate, diluted with toluene so that the solid content was 40 mass%, and 0.5 mol of azobisisobutyronitrile under a nitrogen stream. % And copolymerized to obtain mold release agent A. The weight average molecular weight of the polymer obtained at this time was 30000.

(Example 11)

A release film for manufacturing an ultra-thin layered ceramic green sheet was obtained in the same manner as in Example 1 except that the composition was changed to a coating solution having the composition shown below.

Methyl ethyl ketone 49.43 parts by mass

toluene 49.43 parts by mass

Binder comprising a cationic curable material a:

Celloxide(registered trademark) 2021P 0.90 parts by mass

Mold release agent b: One-end epoxy-modified polydimethylsiloxane

0.10 parts by mass

(Product name: X22-173DX, manufactured by Shin-Etsu Chemical Co., Ltd., solid content 100%)

Acid generator: UV CATA211 0.26 parts by mass

(Example 12)

A release film for manufacturing an ultra-thin layered ceramic green sheet was obtained in the same manner as in Example 1 except that the composition was changed to a coating solution having the composition shown below.

Methyl ethyl ketone 49.43 parts by mass

toluene 49.43 parts by mass

Binder comprising a cationic curable material a:

Celloxide(registered trademark) 2021P 0.90 parts by mass

Release agent b: perfluoro-based release agent 0.10 parts by mass

Acid generator: UV CATA211 (active ingredient 19% by mass)

0.26 parts by mass

(Example 13)

A release film for manufacturing an ultra-thin layered ceramic green sheet was obtained in the same manner as in Example 1 except that the composition was changed to a coating solution having the composition shown below.

Methyl ethyl ketone 49.43 parts by mass

toluene 49.43 parts by mass

Binder comprising a cationic curable material a:

Celloxide(registered trademark) 2021P 0.95 parts by mass

Mold release agent b: UV Poly215 0.05 parts by mass

Acid generator: UV CATA211 (active ingredient 19% by mass)

0.26 parts by mass

(Example 14)

A release film for manufacturing an ultra-thin layered ceramic green sheet was obtained in the same manner as in Example 1 except that the composition was changed to a coating solution having the composition shown below.

Methyl ethyl ketone 49.43 parts by mass

toluene 49.43 parts by mass

Binder comprising a cationic curable material a:

Celloxide(registered trademark) 2021P 0.80 parts by mass

Mold release agent b: UV Poly215 0.20 parts by mass

Acid generator: UV CATA211 (active ingredient 19% by mass)

0.26 parts by mass

(Example 15)

A release film for manufacturing ultrathin ceramic green sheets was obtained in the same manner as in Example 1 except that the film thickness of Example 1 was changed to a laminated film X2 of 25 μm.

(Example 16)

A release film for manufacturing an ultra-thin layered ceramic green sheet was obtained in the same manner as in Example 1 except that the release layer film had a thickness of 30 nm.

(Example 17)

A release film for manufacturing an ultra-thin layered ceramic green sheet was obtained in the same manner as in Example 1 except that the release layer film had a thickness of 200 nm.

(Example 18)

A release film for manufacturing an ultra-thin layered ceramic green sheet was obtained in the same manner as in Example 1 except that the release layer film had a thickness of 0.8 µm.

(Comparative Example 1)

A release film for manufacturing an ultra-thin layered ceramic green sheet was obtained in the same manner as in Example 1 except that the composition was changed to a coating solution having the composition shown below.

Methyl ethyl ketone 49.43 parts by mass

toluene 49.43 parts by mass

Binder comprising a cationic curable material a:

Celloxide(registered trademark) 2021P 1.00 parts by mass

Acid generator: UV CATA211 (active ingredient 19% by mass)

0.26 parts by mass

(Comparative Example 2)

A release film for manufacturing an ultra-thin layer ceramic sheet was obtained in the same manner as in Example 1, except that it was changed to laminated film X3 (E5101-25 μm, manufactured by Toyo Corporation) instead of laminated film X1. In E5101, both the surface layer A and the surface layer B contained inorganic particles, and Sa of both layers of the surface layer A and the surface layer B was 24 nm.

(Comparative Example 3)

A release film for manufacturing an ultra-thin layered ceramic green sheet was obtained in the same manner as in Example 1, except that it was changed to a coating solution having the composition shown below and coated so that the release layer had a thickness of 0.8 µm.

Methyl ethyl ketone 44.75 parts by mass

toluene 44.75 parts by mass

Binders comprising photo-radical curable materials:

Dipentaerythritol hexaacrylate

9.90 parts by mass

(Product name: A-DPH, manufactured by Shinnakamura Kagaku High School, 100% by mass of solids)

Mold release agent b: BYK-UV3500 0.10 parts by mass

Photo radical polymerization initiator:

Methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one

0.50 parts by mass

(Product name: IRGACURE (registered trademark) 907, manufactured by BASF, 100% by mass of active ingredient)

Since the release film for ceramic green sheet production of the present invention has a very smooth release surface and no fear of erosion of the release layer by an organic solvent, even an ultra-thin layer having a thickness of 1 µm or less has low peeling force, and thus has a low peel force. It is possible to mold a ceramic green sheet with few defects. In addition, by using a cationically curable material having a small curing shrinkage, it is possible to provide a release film for ceramic green sheet production, in which the appearance defects such as curl are suppressed, and there is no fear that the accuracy of electrode printing is lowered.

Claims (9)

A release film provided with a release layer on the surface layer A of a polyester film having a surface layer A substantially free of inorganic particles, the release layer comprising a binder a containing a cationically curable material and one or more release agents b A release film for the production of ceramic green sheets formed by curing the composition. The release film according to claim 1, wherein the difference between the diiodomethane contact angle θ ₁ on the surface of the release layer and the diiodomethane contact angle θ _{2 on} the surface of the release layer after toluene immersion is 3.0° or less as an absolute value. The release film for producing a ceramic green sheet according to claim 1 or 2, wherein at least one kind of release agent b is a compound containing a silicone skeleton. The release film for manufacturing a ceramic green sheet according to any one of claims 1 to 3, wherein the binder a containing a cationically curable material contains 80% by mass or more of the total solids of the release layer. The ceramic green according to any one of claims 1 to 4, wherein the binder a containing the cationically curable material contains at least one compound selected from compounds having an alicyclic epoxy group in the molecule and compounds having an oxetane ring. Release film for sheet production. The release film for producing a ceramic green sheet according to any one of claims 1 to 5, wherein at least one of the release agents b is silicone containing an alicyclic epoxy group. The release film for manufacturing a ceramic green sheet according to any one of claims 1 to 6, wherein the surface roughness (Sa) of the surface of the release layer is 7 nm or less, and the maximum projection height (P) is 100 nm or less. A method for producing a ceramic green sheet having a thickness of 0.2 µm to 1.0 µm, the method for producing a ceramic green sheet using the release film for producing a ceramic green sheet according to any one of claims 1 to 7. The manufacturing method of the ceramic capacitor employing the manufacturing method of the ceramic green sheet of Claim 8.