JP6477989B1 - Release film for manufacturing ceramic green sheets - Google Patents

Abstract

The present invention provides an excellent release film for producing a ceramic green sheet that can achieve both prevention of pinholes and partial thickness variations and reduction of unwinding electrification even when the thickness of the ceramic green sheet is reduced. about. A polyester film substantially free of inorganic particles is used as a base material, a release coating layer is provided on one surface of the base material, and particles are contained on the other surface. For producing a ceramic green sheet having an easy-to-slip coating layer, wherein the easy-slip coating layer is cured with an acrylic resin and a composition containing at least one crosslinking agent selected from an oxazoline-based crosslinking agent or a carbodiimide-based crosslinking agent Release film.

Description

  The present invention relates to a release film for producing a ceramic green sheet. More specifically, the present invention relates to a release film for producing a ceramic green sheet that can provide all of prevention of pinholes and partial thickness variations and reduction of unwinding electrification even when the ceramic green sheet is thinned.

  Conventionally, the release film for producing ceramic green sheets is stored in a rolled state by making the surface roughness of the surface (back surface) opposite to the surface provided with the release agent layer of the base film relatively rough. A technique is disclosed that eliminates problems such as sticking (blocking) of the release film for producing a ceramic green sheet when it is applied (see, for example, Patent Document 1). However, such a conventional technique has a problem that pinholes and partial thickness variations occur due to large protrusions.

  In order to reduce the height of the protrusion, a technique for preventing the pinhole and the partial thickness variation from occurring in the ceramic green sheet by filling the protrusion on the back surface with the coating layer is disclosed (for example, , See Patent Document 2). However, according to such a conventional technique, although the protrusion height is low, the protrusion density is low, so the pressure applied to the protrusion is large, and when the ceramic green sheet is further thinned, pinholes are generated. there were.

JP 2003-203822 A JP 2014-144636 A

  The present invention has been made against the background of such prior art problems. That is, the object of the present invention is to produce an excellent ceramic green sheet that can prevent pinholes and partial thickness variations and reduce unwinding charging even when the ceramic green sheet is thinned. It is to provide a release film.

As a result of intensive studies to achieve the above object, the present inventors have completed the present invention. That is, the present invention has the following configuration.
1. An easy-sliding coating layer comprising a polyester film substantially free of inorganic particles as a base material, having a release coating layer on one surface of the base material, and containing particles on the other surface A release film for producing a ceramic green sheet, in which an easy-slip coating layer is cured with a composition containing an acrylic resin and at least one crosslinking agent selected from an oxazoline crosslinking agent or a carbodiimide crosslinking agent.
2. The release film for producing a ceramic green sheet according to the first aspect, wherein the glass transition temperature of the acrylic resin is 50 ° C. or higher and 110 ° C. or lower.
3. The release film for producing a ceramic green sheet according to the first or second aspect, wherein the acid value of the acrylic resin is 40 mgKOH / g or more and 400 mgKOH / g or less.
4). The region surface average roughness (Sa) of the easy-coating layer is 1 nm or more and 25 nm or less, the maximum protrusion height (P) is 60 nm or more and 500 nm or less, and the average length (RSm) of the roughness curve element is 10 μm or less. A release film for producing a ceramic green sheet according to any one of the first to third aspects.
5. The release film for producing a ceramic green sheet according to any one of the first to fourth aspects, wherein the thickness of the easy-slip coating layer is 0.001 μm or more and 2 μm or less.
6). The manufacturing method of the ceramic green sheet using the release film for ceramic green sheet manufacture in any one of the said 1st-5th.
7). The method for producing a ceramic green sheet according to the sixth aspect, wherein the thickness of the ceramic green sheet to be produced is 0.2 μm or more and 2.0 μm or less.
8). A method for producing a ceramic capacitor, which employs the method for producing a ceramic green sheet according to the sixth or seventh aspect.

  According to the present invention, even when a ceramic green sheet is thinned, excellent mold release for manufacturing a ceramic green sheet that can prevent pinholes and partial thickness variations and reduce unwinding charging all. A film 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 (hereinafter sometimes simply referred to as a release film) has a release coating layer on one side of a biaxially oriented polyester film as a base film, and particles on the other side. A release film having an easy-to-slip coating layer.

  In order to increase the protrusion density of the easy-smooth surface, the present inventors can cope with the recent reduction in green sheet thickness by keeping the average length (RSm) of the roughness curve element of the easy-slip surface in a specific range. A release film has been proposed (International Application No. PCT / JP2017 / 017354). By increasing the protrusion density by such a technique, it is preferable that good winding properties and prevention of pinholes and partial thickness variations can be provided while maintaining the protrusion height low.

  In the present invention, the slippery coating layer is formed by curing a composition containing at least one crosslinking agent selected from an acrylic resin and an oxazoline crosslinking agent or a carbodiimide crosslinking agent as the slipping coating layer. The hardness of the slidable coating layer becomes moderately high and deformation of the easy-to-slip coating layer is less likely to occur when wound after the release coating layer coating. In general, it is known that as the contact area of two objects in contact with each other increases, the charge upon peeling when the two objects are peeled off increases. If the amount of deformation of the easy-slip coating layer is small, the contact area between the easy-slip coating layer and the release layer is small, so that unwinding charging when the release film roll is unwound can be suppressed, which is preferable. It is preferable that the unwinding charge is small because it is possible to prevent an abnormal quality of the ceramic capacitor due to adhesion of environmental foreign substances to the release surface. In ceramic sheet thinning, which is a recent trend, there is a problem even if minute environmental foreign matter adheres to the release surface, which has not been a problem in the past. A release film having a composition is effective, and it is more preferable to add the average length (RSm) of the roughness curve element of the slippery coating layer within a specific range.

(Base film)
The film preferably used as a substrate in the present invention is a film composed of a polyester resin, and a polyester film mainly containing at least one selected from polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. preferable. Moreover, the film which consists of polyester which the third component monomer copolymerized as a part of dicarboxylic acid component of the above polyesters or a diol component may be sufficient. Among these polyester films, a polyethylene terephthalate film is most preferable from the balance between physical properties and cost.

  The polyester film may be a single layer or a multilayer. Moreover, as long as it exists in the range with the desired effect in this invention, these each layer can be made to contain various additives in a polyester resin as needed. Examples of the additive include an antioxidant, a light-resistant agent, an anti-gelling agent, an organic wetting agent, an antistatic agent, and an ultraviolet absorber.

(Easy-slip coating layer)
The release film of the present invention has an easy-slip coating layer on one surface of a polyester base film as described above. The easy-slip coating layer preferably contains at least a binder resin and particles.

(Binder resin in the easy-to-slip coating layer)
It is preferable that acrylic resin is contained as binder resin which comprises the easy-slip coating layer in this invention. The acrylic resin is preferably an acrylic resin having a hydroxyl group and a carboxyl group in the molecule. More preferably, the structural unit having a hydroxyl group is contained in an amount of 20 to 90 mol% in 100 mol% of all the structural units. It is preferable that the constituent unit having a hydroxyl group is 20 mol% or more because the water-solubility of the acrylic resin can be appropriately maintained. On the other hand, when it is 90 mol% or less, it is preferable that the hydroxyl group of the acrylic resin and the particles contained in the easy-coating layer do not cause an extreme interaction and the particles are uniformly dispersed.

  In order to introduce a hydroxyl group into an acrylic resin, a monomer having a hydroxy group such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxyethyl ( A ring-opening adduct of γ-butyrolactone or ε-caprolactone to (meth) acrylate may be used as a copolymerization component. Among these, 2-hydroxyethyl (meth) acrylate is preferable because it does not inhibit water solubility. Two or more of these may be used in combination. Needless to say, the acrylic resin referred to in the present invention includes a methacrylic resin.

  The hydroxyl value of the acrylic resin is preferably 2 mgKOH / g or more, more preferably 5 mgKOH / g or more, and still more preferably 10 mgKOH / g or more. If the hydroxyl value of the acrylic resin is 2 mgKOH / g or more, the water solubility of the acrylic resin is good, which is preferable.

  The hydroxyl value of the acrylic resin is preferably 250 mgKOH / g or less, more preferably 230 mgKOH / g or less, still more preferably 200 mgKOH / g or less. When the hydroxyl value of the acrylic resin is 250 mgKOH / g or less, it is preferable that the hydroxyl group of the acrylic resin and the particles contained in the easy-coating layer do not cause an interaction and the particles are uniformly dispersed.

  The acrylic resin used in the present invention is preferably a resin having a carboxyl group in addition to a hydroxyl group. By having a carboxyl group, it is possible to form a crosslinked structure with a crosslinking agent and to easily impart water solubility. Examples include monomers containing carboxy groups such as (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid and fumaric acid, and monomers containing acid anhydride groups such as maleic anhydride and itaconic anhydride.

  The monomer having a carboxyl group is preferably 4 mol% or more, more preferably 10 mol% or more, in 100 mol% of all structural units of the acrylic resin. When it is 4 mol% or more, it is easy to form a crosslinked structure in the slippery coating layer and to impart water solubility, which is preferable. 65 mol% or less is preferable and the monomer which has a carboxyl group has more preferable 50 mol% or less. When it is 65 mol% or less, the Tg of the resulting coating film is not too high with respect to the preferred range described later, and the film-forming property and the stretching suitability in in-line coating are good, which is preferable.

  In order to develop good water solubility, it is preferable to neutralize the carboxyl group introduced into the acrylic resin by copolymerization of acrylic acid or methacrylic acid. Examples of basic neutralizing agents include amine compounds such as ammonia, trimethylamine, triethylamine, and dimethylaminoethanol, and inorganic basic substances such as potassium hydroxide and sodium hydroxide. An amine compound is preferably used as a neutralizing agent for ease of formation and formation of a crosslinked structure. Among these, ammonia is most preferable from the viewpoint that particle aggregation does not occur. Moreover, as a neutralization rate, it is preferable that it is 30 mol%-95 mol%, More preferably, it is 40 mol%-90 mol%. When the neutralization rate is 30 mol% or more, the water solubility of the acrylic resin is sufficient, the acrylic resin is easily dissolved during the preparation of the coating solution, and there is no risk of the coating surface after drying being whitened. preferable. On the other hand, when the neutralization rate is 95 mol% or less, the water solubility is not too high, and mixing of alcohol or the like is facilitated in preparing the coating solution, which is preferable.

  The acid value of the acrylic resin is preferably 40 mgKOH / g or more, more preferably 50 mgKOH / g or more, and still more preferably 60 mgKOH / g or more. If the acrylic resin has an acid value of 40 mgKOH / g or more, the number of crosslinking points with the oxazoline crosslinking agent or carbodiimide crosslinking agent is increased, and thus a strong coating film having a higher crosslinking density is obtained.

  The acid value of the acrylic resin is preferably 400 mgKOH / g or less, more preferably 350 mgKOH / g or less, and still more preferably 300 mgKOH / g or less. If the acid value of the acrylic resin is 400 mgKOH / g or less, it is preferable that the carboxyl group of the acrylic resin and the particles contained in the easy-coating layer do not cause an interaction and the particles are uniformly dispersed. It is preferable that the dispersibility of the particles is good because coarse protrusions do not occur on the slippery coated surface and no pinholes in the ceramic sheet occur.

  The glass transition temperature (Tg) of the acrylic resin is preferably 50 ° C. or higher, more preferably 55 ° C. or higher, still more preferably 60 ° C. or higher. When the glass transition temperature of the acrylic resin is 50 ° C. or higher, the hardness of the slippery coating layer is suitably increased.

  The glass transition temperature (Tg) of the acrylic resin is preferably 110 ° C. or less, more preferably 105 ° C. or less, and still more preferably 100 ° C. or less. It is preferable for the glass transition temperature of the acrylic resin to be 110 ° C. or lower because the coating film is uniformly stretched without causing cracks in the stretching step after coating the slippery coating layer.

  As the Tg-adjusting monomer copolymerized to bring the Tg into the above range, a (meth) acrylic monomer or a non-acrylic vinyl monomer can be used. Specific examples of the (meth) acrylic monomer include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and n-amyl (meth). Acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, (Meth) acrylic acid alkyl esters such as stearyl (meth) acrylate; nitrogen-containing acrylic compounds such as (meth) acrylamide, diacetone acrylamide, n-methylol acrylamide, (meth) acrylonitrile, etc. Mer, vinyl methacrylate, and the like. These may be used alone or in combination.

  Non-acrylic vinyl monomers include styrene monomers such as styrene, α-methylstyrene, vinyltoluene (a mixture of m-methylstyrene and p-methylstyrene), chlorostyrene; vinyl acetate, vinyl propionate, vinyl butyrate. , Vinyl caproate, vinyl caprylate, vinyl caprate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, vinyl cyclohexanecarboxylate, vinyl pivalate, vinyl octylate, vinyl monochloroacetate, divinyl adipate, Examples thereof include vinyl esters such as vinyl crotonate, vinyl sorbate, vinyl benzoate and vinyl cinnamate; vinyl halide monomers such as vinyl chloride and vinylidene chloride; and one or more of them can be used.

  It is preferable that the monomer for adjusting Tg is determined as the balance after determining appropriate amounts of the hydroxyl group-containing monomer and the carboxyl group-containing monomer. The Tg of the copolymer is determined by the following Fox formula.

W _n : mass fraction (% by mass) of each monomer
Tg _n : Tg (K) of the homopolymer of each monomer

  As a monomer copolymerized for Tg adjustment, it is preferable to introduce a component that lowers the surface free energy such as a long-chain alkyl group. As the acrylic resin into which the long chain alkyl group is introduced, those having an alkyl group having about 8 to 20 carbon atoms in the side chain of the acrylic resin are preferable. Moreover, it is a polymer which has (meth) acrylic acid ester as a main repeating unit, and the copolymer which contains a C8-C20 long-chain alkyl group in the transesterified part can also be used conveniently.

  The monomer having a long-chain alkyl group in the monomer copolymerized for Tg adjustment is preferably 50 mol% or less, more preferably 40 mol% or less, in 100 mol% of all constituent units of the acrylic resin. When it is 50 mol% or less, the Tg of the resulting coating film is not too low with respect to the preferred range, and the coating film hardness can be maintained high, which is preferable. In the present invention, the monomer having a long-chain alkyl group may be 0 mol% as long as the Tg can maintain a suitable range, but if it is 5 mol% or more, the effect of adjusting the Tg of the acrylic resin Is clear and preferable.

  The acrylic resin used in the present invention can be obtained by known radical polymerization. Any of emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization and the like can be employed. From the viewpoint of handleability, solution polymerization is preferred. Examples of water-soluble organic solvents that can be used for solution polymerization include ethylene glycol n-butyl ether, isopropanol, ethanol, n-methylpyrrolidone, tetrahydrofuran, 1,4-dioxane, 1,3-oxolane, methyl solosolv, and ethyl solosolv. , Ethyl carbitol, butyl carbitol, propylene glycol monopropyl ether, propylene glycol monobutyl ether and the like. These may be used by mixing with water.

  The polymerization initiator may be a known compound that generates a radical, but a water-soluble azo polymerization initiator such as 2,2-azobis-2-methyl-N-2-hydroxyethylpropionamide is preferable. The temperature and time of the polymerization are appropriately selected.

  The weight average molecular weight (Mw) of the acrylic resin is preferably about 10,000 to 200,000. A more preferable range is 20,000 to 150,000. When Mw is 10,000 or more, there is no fear of thermal decomposition in the tenter, which is preferable. When the Mw is 200,000 or less, there is no significant increase in the viscosity of the coating solution, and the coating property is good, which is preferable.

  As the binder of the easy-slip coating layer in the present invention, other binder resins may be used in combination in addition to the acrylic resin. Examples of other binder resins include polyester resins, urethane resins, polyvinyl resins (polyvinyl alcohol, etc.), polyalkylene glycols, polyalkyleneimines, methylcellulose, hydroxycellulose, starches, and the like.

  The content of the acrylic resin in the easy-coating layer is preferably 20% by mass or more and 95% by mass or less in the total solid content. More preferably, it is 30 mass% or more and 90 mass% or less. If it is 20 mass% or more, it is preferable because the carboxyl group as a crosslinking component does not decrease too much and the crosslinking density does not decrease. If it is 95 mass% or less, since the quantity of the crosslinking agent which is the object to bridge | crosslink does not decrease too much and a crosslinking density does not become low, it is preferable.

(Crosslinking agent)
In the present invention, in order to form a crosslinked structure in the slippery coating layer, the slippery coating layer preferably contains at least one crosslinking agent selected from oxazoline-based crosslinking agents or carbodiimide-based crosslinking agents. Inclusion of an oxazoline-based cross-linking agent or carbodiimide-based cross-linking agent improves adhesion to the PET base material and improves cross-linking with the carboxyl group of the acrylic resin to improve the coating strength of the easy-slip layer As a result, unwinding charging when the release film roll is unwound can be suppressed. Other crosslinking agents may be used in combination, and specific crosslinking agents that can be used in combination include urea, epoxy, melamine, isocyanate, and silanol. Moreover, in order to promote a crosslinking reaction, a catalyst etc. can be used suitably as needed.

  As the crosslinking agent having an oxazoline group, for example, a polymerizable unsaturated monomer having an oxazoline group may be used together with other polymerizable unsaturated monomers as required in a conventionally known method (for example, solution polymerization, emulsion polymerization, etc.). Examples thereof include a polymer having an oxazoline group obtained by copolymerization.

  Examples of the polymerizable unsaturated monomer having an oxazoline group include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2- Examples thereof include isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline. These may be used alone or in combination of two or more.

  Other polymerizable unsaturated monomers include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and cyclohexyl (meth). C1-C24 alkyl or cycloalkyl ester of (meth) acrylic acid such as acrylate, lauryl (meth) acrylate, isobornyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, etc. (Meth) acrylic acid hydroxyalkyl ester having 2 to 8 carbon atoms; vinyl aromatic compounds such as styrene and vinyltoluene; (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, dimethylaminoethyl (meth) ) Acrylate, glycidyl (meth) adducts of acrylates and amines; polyethylene glycol (meth) acrylate; N- vinylpyrrolidone, ethylene, butadiene, chloroprene, vinyl propionate, vinyl acetate, and (meth) acrylonitrile. These may be used alone or in combination of two or more.

  Other polymerizable unsaturated monomers are obtained from the viewpoint of improving compatibility with other resins, wettability, cross-linking reaction efficiency, etc., using the obtained cross-linking agent having an oxazoline group as a water-soluble cross-linking agent. It is preferable that it is a body. Examples of hydrophilic monomers include monomers having a polyethylene glycol chain, such as 2-hydroxyethyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, (meth) acrylic acid and polyethylene glycol monoester compounds, 2- Aminoethyl (meth) acrylate and its salt, (meth) acrylamide, N-methylol (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide, (meth) acrylonitrile, sodium styrenesulfonate, etc. are mentioned. Among these, monomers having a polyethylene glycol chain such as methoxypolyethylene glycol (meth) acrylate having high solubility in water and a monoester compound of (meth) acrylic acid and polyethylene glycol are preferable.

  The cross-linking agent having an oxazoline group preferably has an oxazoline group content of 3.0 to 9.0 mmol / g. More preferably, it is within the range of 4.0 to 8.0 mmol / g. If it is in the range of 4.0-8.0 mmol / g, an appropriate crosslinked structure can be formed, which is preferable.

  Examples of the carbodiimide-based crosslinking agent include monocarbodiimide compounds and polycarbodiimide compounds. Examples of the monocarbodiimide compound include dicyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide, dioctylcarbodiimide, t-butylisopropylcarbodiimide, diphenylcarbodiimide, di-t-butylcarbodiimide, and di-β-naphthylcarbodiimide. . As the polycarbodiimide compound, those produced by a conventionally known method can be used. For example, it can be produced by synthesizing an isocyanate-terminated polycarbodiimide by a condensation reaction involving decarbonization of diisocyanate.

  Examples of the diisocyanate that is a raw material for synthesizing the polycarbodiimide compound include isomers of toluylene diisocyanate, aromatic diisocyanates such as 4,4-diphenylmethane diisocyanate, aromatic aliphatic diisocyanates such as xylylene diisocyanate, isophorone diisocyanate and 4 , 4-dicyclohexylmethane diisocyanate, alicyclic diisocyanates such as 1,3-bis (isocyanatomethyl) cyclohexane, hexamethylene diisocyanate, and aliphatic diisocyanates such as 2,2,4-trimethylhexamethylene diisocyanate. From the problem of yellowing, aromatic aliphatic diisocyanates, alicyclic diisocyanates, and aliphatic diisocyanates are preferred.

  The diisocyanate may be used with a molecule controlled to an appropriate degree of polymerization using a compound that reacts with a terminal isocyanate such as monoisocyanate. Examples of monoisocyanates for sealing the ends of polycarbodiimide and controlling the degree of polymerization thereof include phenyl isocyanate, toluylene isocyanate, dimethylphenyl isocyanate, cyclohexyl isocyanate, butyl isocyanate, and naphthyl isocyanate. In addition, a compound having an OH group, —NH 2 group, COOH group, or SO 3 H group can be used as a terminal blocking agent.

  The condensation reaction involving decarbonization of diisocyanate proceeds in the presence of a carbodiimidization catalyst. Examples of the catalyst include 1-phenyl-2-phospholene-1-oxide, 3-methyl-2-phospholene-1-oxide, 1-ethyl-2-phospholene-1-oxide, and 3-methyl-1-phenyl-2. -Phosphorene-1-oxide, phospholene oxides such as these 3-phospholene isomers and the like can be mentioned, and 3-methyl-1-phenyl-2-phospholene-1-oxide is preferable from the viewpoint of reactivity. The amount of the catalyst used can be a catalyst amount.

  The mono- or polycarbodiimide compound described above is desirably kept in a uniform dispersed state when blended with an aqueous coating material. For this purpose, it is emulsified with an appropriate emulsifier and used as an emulsion, or a polycarbodiimide compound. It is preferable to add a hydrophilic segment in the molecular structure of the compound and mix it with the paint in the form of a self-emulsified product or in the form of a self-dissolved product.

  Examples of the carbodiimide-based crosslinking agent used in the present invention include water dispersibility and water solubility. Water-solubility is preferable because it has good compatibility with other water-soluble resins and improves the cross-linking reaction efficiency of the slippery coating layer. In order to make a carbodiimide compound water-soluble, an isocyanate-terminated polycarbodiimide is synthesized by a condensation reaction involving decarbonization of isocyanate, and then a hydrophilic part having a functional group having reactivity with an isocyanate group is added. Can be manufactured.

  Examples of hydrophilic sites include (1) quaternary ammonium salts of dialkylamino alcohols and quaternary ammonium salts of dialkylaminoalkylamines, (2) alkyl sulfonates having at least one reactive hydroxyl group, and the like (3) Examples thereof include poly (ethylene oxide) end-capped with an alkoxy group, a mixture of poly (ethylene oxide) and poly (propylene oxide), and the like. The carbodiimide compound is (1) cationic, (2) anionic, and (3) nonionic when the above hydrophilic moiety is introduced. Especially, the nonionic property which can be compatible regardless of the ionicity of other water-soluble resin is preferable.

  The content of the crosslinking agent in the easy-coating layer is preferably 5% by mass or more and 80% by mass or less in the total solid content. More preferably, it is 10 mass% or more and 70 mass% or less. If it is 5 mass% or more, it is preferable from the crosslinking density of resin of an application layer not falling. If it is 80 mass% or less, since the quantity of the carboxyl group of the acrylic resin which is the object to bridge | crosslink does not decrease too much and a crosslinking density does not become low, it is preferable.

(Particles in the easy-to-slip coating layer)
The slippery coating layer preferably contains lubricant particles in order to impart slipperiness to the surface. The particles may be inorganic particles or organic particles, and are not particularly limited. (1) Silica, kaolinite, talc, light calcium carbonate, heavy calcium carbonate, zeolite, alumina, Barium sulfate, carbon black, zinc oxide, zinc sulfate, zinc carbonate, zirconium oxide, titanium dioxide, satin white, aluminum silicate, diatomaceous earth, calcium silicate, aluminum hydroxide, hydrous halloysite, calcium carbonate, magnesium carbonate, calcium phosphate, hydroxide Inorganic particles such as magnesium and barium sulfate, (2) acrylic or methacrylic, vinyl chloride, vinyl acetate, nylon, styrene / acrylic, styrene / butadiene, polystyrene / acrylic, polystyrene / isoprene, polystyrene / Iso Ren-based, methyl methacrylate / butyl methacrylate-based, melamine-based, polycarbonate-based, urea-based, epoxy, urethane, phenolic, diallyl phthalate, and organic particles of a polyester or the like. Silica is particularly preferably used in order to give appropriate slipperiness to the coating layer.

  The average particle size of the particles is preferably 10 nm or more, more preferably 20 nm or more, and further preferably 30 nm or more. When the average particle size of the particles is 10 nm or more, it is preferable that aggregation is difficult and slipperiness can be secured.

  The average particle size of the particles is preferably 1000 nm or less, more preferably 800 nm or less, and even more preferably 600 nm or less. It is preferable that the average particle diameter of the particles is 1000 nm or less because transparency is maintained and the particles do not fall off.

  In addition, for example, a mixture of a small particle having an average particle diameter of about 10 to 270 nm and a large particle having an average particle diameter of about 300 to 1000 nm may be used as described later, the region surface average roughness (Sa), the maximum protrusion height ( While maintaining P) small, it is preferable to reduce the average length (RSm) of the roughness curve element to achieve both slipperiness and smoothness, and particularly preferably, a small particle of 30 nm to 250 nm and an average particle It is to use together large particles having a diameter of 350 to 600 nm. When mixing small particles and large particles, it is preferable that the mass content of the small particles is larger than the mass content of the large particles with respect to the entire solid content of the coating layer.

  It is particularly preferable to use organic particles in terms of preventing the particles from falling off the easy-to-slip coating layer. Use of the organic particles is preferable because the interaction between the binder of the easy-coating layer and the cross-linking agent component becomes strong, and it is easy to prevent the falling off. Among the organic particles, acrylic resin particles and / or methacrylic resin particles having a chemical structure similar to that of the acrylic resin present in the easy-to-slip coating layer are particularly preferable in terms of preventing the particles from dropping off from the easy-to-slip coating layer. . These organic particles are preferably contained as particles having a relatively large average particle diameter, which is likely to cause the problem of dropping off of the particles from the easy-coating layer. For example, the organic particles are contained as particles having an average particle diameter of 300 to 1000 nm. Is preferred. More preferably, it is contained as particles having an average particle size of 350 to 600 nm. Of course, it is a particularly preferable aspect that the organic particles having the average particle diameter are acrylic resin particles and / or methacrylic resin particles.

  The average particle size of the particles is measured by observing particles in the cross section of the processed film with a transmission electron microscope or a scanning electron microscope, observing 100 non-aggregated particles, and using the average value for the average particle size. It was performed by the method of making the diameter.

  The shape of the particle is not particularly limited as long as it satisfies the object of the present invention, and spherical particles and non-spherical particles can be used. The particle diameter of the irregular shaped particles can be calculated as the equivalent circle diameter. The equivalent circle diameter is a value obtained by dividing the observed area of the particle by π and calculating the square root to double.

  The ratio of the particles to the total solid content of the easy-coating layer is preferably 50% by mass or less, more preferably 40% by mass or less, and still more preferably 30% by mass or less. When the ratio of the particles to the total solid content of the easy-to-slip coating layer is 50% by mass or less, transparency is maintained, and the particles are not easily dropped from the easy-slip coating layer, which is preferable.

  The ratio of the particles to the total solid content of the easy-coating layer is preferably 1% by mass or more, more preferably 1.5% by mass or more, and further preferably 2% by mass or more. If the ratio of the particles to the total solid content of the slippery coating layer is 1% by mass or more, the slipperiness can be secured, which is preferable.

  As a method for measuring the content of particles contained in the easy-to-slip coating layer, for example, when the easy-coating layer contains an organic resin and inorganic particles, the following method can be used. First, the slippery coating layer provided on the processed film is extracted from the processed film using a solvent or the like and dried to take out the slippery coating layer. Next, only the inorganic component can be obtained by applying heat to the resulting slippery coating layer and burning off the organic component contained in the slippery coating layer with heat. By measuring the weight of the resulting inorganic component and the easy-to-slip coating layer before burning off, the mass% of the particles contained in the easy-to-slip coating layer can be measured. At this time, measurement can be performed with high accuracy by using a commercially available differential heat / thermogravimetric simultaneous measurement device. In addition, the ratio in said all solid content of the easy-coat layer of particle | grains means the ratio of the total amount of multiple types, when multiple types of particle | grains exist.

(Additive in easy-to-slip coating layer)
In order to impart other functionality to the slippery coating layer, various additives may be contained within a range that does not impair the coating appearance. Examples of the additive include fluorescent dyes, fluorescent brighteners, plasticizers, ultraviolet absorbers, pigment dispersants, foam suppressors, antifoaming agents, and preservatives.

  The easy-slip coating layer may contain a surfactant for the purpose of improving leveling properties during coating and defoaming the coating solution. The surfactant may be any of cationic, anionic, and nonionic surfactants, but is preferably a silicone, acetylene glycol, or fluorine surfactant. These surfactants are preferably contained in the coating layer in such a range that the appearance of the coating does not become abnormal when added excessively.

  As the coating method, both a so-called in-line coating method in which a polyester base film is simultaneously formed and a so-called off-line coating method in which a polyester base film is formed and then separately applied with a coater can be applied. Is more efficient and more preferable.

  As a method for applying the coating solution to a polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”) film, any known method can be used. For example, reverse roll coating method, gravure coating method, kiss coating method, die coater method, roll brush method, spray coating method, air knife coating method, wire bar coating method, pipe doctor method, impregnation coating method, curtain coating method, etc. Can be mentioned. These methods are applied alone or in combination.

  In the present invention, as a method of providing an easy-slip coating layer on a polyester film, a method of coating and drying a coating solution containing a solvent, particles and a resin on the polyester film can be mentioned. Examples of the solvent include an organic solvent such as toluene, water, or a mixed system of water and a water-soluble organic solvent. Preferably, from the viewpoint of environmental problems, water alone or a so-called aqueous system in which water is mixed with a water-soluble organic solvent. These solvents are preferred.

  The concentration of the solid content of the easy-to-slip coating liquid is preferably 0.5% by mass or more, more preferably 1% by mass or more, although it depends on the type of binder resin and the type of solvent. The solid concentration of the coating solution is preferably 35% by mass or less, and more preferably 20% by mass or less.

  The drying temperature after coating also depends on the type of binder resin, the type of solvent, the presence or absence of a crosslinking agent, the solid content concentration, etc., but is preferably 70 ° C. or higher, and preferably 250 ° C. or lower.

(Manufacture of polyester film)
In this invention, the polyester film used as a base film can be manufactured according to the manufacturing method of a general polyester film. For example, the polyester resin is melted and the non-oriented polyester extruded and formed into a sheet shape is stretched in the longitudinal direction by utilizing the speed difference of the roll at a temperature equal to or higher than the glass transition temperature, and then stretched in the transverse direction by a tenter. The method of performing heat processing is mentioned. In addition, a method of biaxial stretching in the tenter at the same time in the vertical and horizontal directions is also mentioned.

  In the present invention, the polyester film as the base film may be a uniaxially stretched film or a biaxially stretched film, but is preferably a biaxially stretched film.

  The thickness of the polyester film substrate is preferably 5 μm or more, more preferably 10 μm or more, and further preferably 15 μm or more. When the thickness is 5 μm or more, it is preferable that wrinkles do not easily occur during conveyance of the film.

  The thickness of the polyester film substrate is preferably 50 μm or less, more preferably 45 μm or less, and even more preferably 40 μm or less. A thickness of 40 μm or less is preferable because the cost per unit area is reduced.

  In the case of in-line coating, it may be applied to an unstretched film before stretching in the machine direction or may be applied to a uniaxially stretched film after stretching in the machine direction and before stretching in the transverse direction. When coating is performed before stretching in the machine direction, it is preferable to provide a drying step before roll stretching. When coating on a uniaxially stretched film before stretching in the transverse direction, the film heating process in the tenter can also serve as the drying process, and therefore it is not always necessary to provide a separate drying process. The same applies to simultaneous biaxial stretching.

  The film thickness of the slippery coating layer is preferably 0.001 μm or more, more preferably 0.01 μm or more, still more preferably 0.02 μm or more, and particularly preferably 0.03 μm or more. It is preferable that the thickness of the coating layer is 0.001 μm or more because the film forming property of the coating film is maintained and a uniform coating film can be obtained.

  The film thickness of the easy-slip coating layer is preferably 2 μm or less, more preferably 1 μm or less, still more preferably 0.8 μm or less, and particularly preferably 0.5 μm or less. It is preferable that the coating layer has a thickness of 2 μm or less because there is no risk of blocking.

  A ceramic green sheet to be coated and molded on a mold release coating layer to be described later is wound into a roll together with the mold release film after coating and molding. At this time, it winds up in the state which the slipperiness application layer of the release film contacted the ceramic green sheet surface. In order not to generate defects on the surface of the ceramic green sheet, the outer surface of the easy-to-slip coating layer (the surface of the easy-to-slip coating layer of the entire coating film not in contact with the polyester film) needs to be reasonably flat. The surface average roughness (Sa) is preferably 1 nm to 25 nm and the maximum protrusion height (P) is preferably 60 nm to 500 nm.

  If the average surface roughness (Sa) of the outer surface of the easy-to-slip coating layer is 1 nm or more and the maximum protrusion height (P) is 60 nm or more, the easy-to-slip coating surface is not too smooth and maintains an appropriate slipperiness. This is preferable because it is possible. If the area surface average roughness (Sa) is 25 nm or less and the maximum protrusion height (P) is 500 nm or less, the easy-slip coating surface does not become too rough, and defects in the ceramic green sheet due to the protrusion do not occur.

  In the present invention, in addition to setting the region surface average roughness (Sa) and the maximum protrusion height (P) within the above ranges, the average length (RSm) of the roughness curve elements is preferably 10 μm or less. By controlling the average length (RSm) of the roughness curve element to 10 μm or less, the number of protrusions per unit area increases. Increasing the number of protrusions is preferable because the pressure applied to each protrusion is dispersed and reduced, and thus pinholes can be effectively suppressed. The average length (RSm) of the roughness curve element is more preferably 5 μm or less, and further preferably 3 μm or less. However, when the average length (RSm) of the roughness curve element is too small, it is related to the excessive content of particles in the easy-to-slip coating layer, and the area surface average roughness (Sa) becomes large. In addition, since it is also related to an increase in the maximum protrusion height (P), it is preferably 0.1 μm or more, may be 0.5 μm or more, and may be 1 μm or more.

  In the present invention, in order to make the average length (RSm) of the roughness curve element within a predetermined range, it is preferable that the average particle size of the particles contained in the slippery coating layer is 1000 nm or less. More preferably, it is 800 nm or less, More preferably, it is 600 nm or less. When the particle diameter is 1000 nm or less, the distance between the particles does not become too large, and RSm is preferably adjusted to a predetermined range.

The surface free energy of the slipperiness coating layer is preferably 45 mJ / ^{m 2} or less, more preferably 40 mJ / ^{m 2} or less. When the surface free energy of the easy-slip coating layer is 45 mJ / m ² or less, environmental foreign substances are less likely to adhere to the process, and foreign substances are less likely to adhere to the release surface. It is preferable that no pinhole is generated.

(Release coating layer)
The resin constituting the release coating layer in the present invention is not particularly limited, and silicone resins, fluororesins, alkyd resins, various waxes, aliphatic olefins and the like can be used, and each resin can be used alone or in combination of two or more. You can also

  As the release coating layer in the present invention, for example, a silicone resin is a resin having a silicone structure in the molecule, and examples thereof include curable silicones, silicone graft resins, and modified silicone resins such as alkyl modification. It is preferable to use a reactive cured silicone resin from the viewpoint of properties. As the reactive cured silicone resin, an addition reaction type, a condensation reaction type, an ultraviolet ray or electron beam curing type, or the like can be used. More preferably, a low-temperature curable addition reaction system that can be processed at a low temperature, and an ultraviolet ray or electron beam curing system are preferable. By using these materials, the polyester film can be processed at a low temperature. Therefore, there is little thermal damage to the polyester film during processing, a polyester film with high flatness is obtained, and defects such as pinholes are reduced even when manufacturing ultra-thin ceramic green sheets with a thickness of 0.2 to 2.0 μm. Can do.

  Examples of the addition reaction type silicone resin include those obtained by reacting and curing polydimethylsiloxane having a vinyl group introduced into the terminal or side chain thereof with hydrodienesiloxane using a platinum catalyst. At this time, it is more preferable to use a resin that can be cured at 120 ° C. within 30 seconds because processing at a low temperature is possible. As an example, low temperature addition curing type (LTC1006L, LTC1056L, LTC300B, LTC303E, LTC310, LTC314, LTC350G, LTC450A, LTC371G, LTC750A, LTC755, LTC85A, YC85A, UV85C, LTC85A, etc.) -510, BY24-561, BY24-562, etc.), Shin-Etsu Chemical Co., Ltd. solvent addition + UV curing type (X62-5040, X62-5065, X62-5072T, KS5508 etc.), dual cure curing type (X62-2835, X62) -2834, X62-1980, etc.).

  As a silicone resin of the condensation reaction system, for example, a polydimethylsiloxane having an OH group at the end and a polydimethylsiloxane having an H group at the end are subjected to a condensation reaction using an organotin catalyst to form a three-dimensional crosslinked structure. Can be mentioned.

  Examples of UV curable silicone resins include those that use the same radical reaction as ordinary silicone rubber crosslinks as the most basic types, those that introduce photopolymerization by introducing unsaturated groups, and those that decompose onium salts with UV light. Examples include those that generate a strong acid and then cleave the epoxy group to crosslink, and those that crosslink by the addition reaction of thiol to vinylsiloxane. Further, an electron beam can be used instead of the ultraviolet rays. Electron beams have stronger energy than ultraviolet rays, and can use a radical crosslinking reaction without using an initiator as in the case of ultraviolet curing. Examples of the resin used include UV curable silicones (X62-7028A / B, X62-7052, X62-7205, X62-7622, X62-7629, X62-7660, etc.) manufactured by Shin-Etsu Chemical, Momentive Performance UV curable silicones manufactured by Materials (TPR6502, TPR6501, TPR6500, UV9300, UV9315, XS56-A2982, UV9430, etc.), UV curable silicones manufactured by Arakawa Chemical (Silicolys UV POLY200, POLY215, POLY201, KF-UV265AM, etc.) ).

  As the ultraviolet curable silicone resin, polydimethylsiloxane modified with acrylate or glycidoxy may be used. Mixing these modified polydimethylsiloxanes with polyfunctional acrylate resins or epoxy resins and using them in the presence of an initiator can also provide good release performance.

  As other examples of resins used, alkyd resins and acrylic resins modified with stearyl and lauryl, alkyd resins obtained by reaction of methylated melamine, acrylic resins, and the like are also suitable.

  Examples of the aminoalkyd resin obtained by the reaction of methylated melamine include Tesfine 303, Tesfine 305, and Tesfine 314 manufactured by Hitachi Chemical Co., Ltd. Examples of the aminoacrylic resin obtained by the reaction of methylated melamine include Tesfine 322 manufactured by Hitachi Chemical Co., Ltd.

  When using the said resin for the mold release coating layer in this invention, it may be used by 1 type and may be used in mixture of 2 or more types. Moreover, in order to adjust peeling force, it is also possible to mix additives, such as a light peeling additive and a heavy peeling additive.

  The release coating layer in the present invention may contain particles having a particle size of 1 μm or less, but it is preferable that substantially no component forming protrusions such as particles is formed from the viewpoint of pinhole generation.

  You may add additives, such as a contact | adherence improving agent and an antistatic agent, to the release coating layer in this invention. In order to improve the adhesion to the substrate, it is also preferable that the polyester film surface is subjected to pretreatment such as anchor coating, corona treatment, plasma treatment, atmospheric pressure plasma treatment, etc. before providing the release coating layer.

  In the present invention, the thickness of the release coating 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 0.005 to 2.0 μm. The range is good. When the thickness of the release coating layer is 0.005 μm or more, the peeling performance is maintained, which is preferable. Moreover, when the thickness of the release coating layer is 2.0 μm or less, the curing time is not excessively long, and it is preferable that there is no possibility of uneven thickness of the ceramic green sheet due to a decrease in the planarity of the release film. In addition, since the curing time does not become too long, the resin constituting the release coating layer does not have a possibility of agglomeration and there is no possibility of forming protrusions.

  The outer surface of the film on which the release coating layer is formed (the surface of the release coating layer of the entire coating film that is not in contact with the polyester film) is flat so as not to cause defects in the ceramic green sheet applied and molded thereon. It is desirable that the area surface average roughness (Sa) is 5 nm or less and the maximum protrusion height (P) is 30 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 20 nm or less. If the surface roughness of the region is 5 nm or less and the maximum protrusion height is 30 nm or less, there is no occurrence of defects such as pinholes when forming the ceramic green sheet, and the yield is favorable. It can be said that the smaller the surface average surface roughness (Sa), the better, but it may be 0.1 nm or more, or 0.3 nm or more. It can be said that the smaller the maximum protrusion height (P) is, the better, but it may be 1 nm or more, or 3 nm or more.

  In the present invention, in order to adjust the film surface on which the release coating layer is formed to a predetermined roughness range, it is preferable that the PET film does not substantially contain inorganic particles. In the present invention, “substantially does not contain inorganic particles” means that, when the element derived from the particles is quantitatively analyzed by fluorescent X-ray analysis for both the base film and the release coating layer, it is 50 ppm or less. It is defined as being preferably 10 ppm or less, and most preferably below the detection limit. This means that even if particles are not actively added to the base film, contaminants derived from foreign substances and raw material resin or dirt adhering to the line or equipment in the film manufacturing process will be peeled off and mixed into the film. It is because there is a case to do.

  In the present invention, the method for forming the release coating layer is not particularly limited, and a coating solution in which a release resin is dissolved or dispersed is spread on one surface of the polyester film of the substrate by coating or the like, Etc. are removed by drying, followed by heat drying, heat curing or ultraviolet curing. At this time, the drying temperature at the time of solvent drying and thermosetting is preferably 180 ° C. or less, more preferably 150 ° C. or less, and most preferably 120 ° C. or less. The heating time is preferably 30 seconds or less, and more preferably 20 seconds or less. When the temperature is 180 ° C. or lower, the flatness of the film is maintained, and there is little possibility of causing uneven thickness of the ceramic green sheet. When the temperature is 120 ° C. or less, the film can be processed without impairing the flatness of the film, and the possibility of causing uneven thickness of the ceramic green sheet is further reduced, which is particularly preferable.

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

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

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

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

  The release film for producing a ceramic green sheet of the present invention is used for producing 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. A conductive layer for forming the first or second internal electrode is printed on the coated and dried ceramic green sheet. A ceramic green sheet, a ceramic green sheet printed with a conductive layer for constituting the first internal electrode, and a ceramic green sheet printed with a conductive layer for constituting the second internal electrode are appropriately laminated and pressed. Thus, a mother laminate is obtained. The mother laminated body is divided into a plurality of parts to produce a raw ceramic body. A ceramic body is obtained by firing a raw ceramic body. Thereafter, the multilayer ceramic capacitor can be completed by forming the first and second external electrodes.

  Next, the present invention will be described in detail using examples and comparative examples, but the present invention is naturally not limited to the following examples. The evaluation method used in the present invention is as follows.

[NMR measurement]
The ratio of the copolymerization component introduced into the acrylic polyol was determined by nuclear magnetic resonance spectroscopy ( ¹ H—N
MR, ¹³ C-NMR: Varian Unity 400 (manufactured by Agilent). The measurement was carried out by removing the solvent in the synthesized acrylic polyol with a vacuum dryer and then dissolving the dried product in deuterated chloroform. From the obtained NMR spectrum, the peak of chemical shift δ (ppm) attributed to the site of each group was identified. The integrated intensity of each peak obtained was determined, and the composition ratio (mol%) of the copolymerization component introduced into the acrylic polyol was confirmed from the hydrogen number and the integrated intensity of each group site.

[Confirmation of Tg]
The Tg of each acrylic polyol was determined from the composition ratio of the copolymerization component determined by the NMR measurement and the above-described Fox formula.

[Stretchability]
In order to evaluate the stretchability of the acrylic polyol itself, the synthesized acrylic polyols (1) to (13) were mixed with a mixed solvent (25% of isopropanol 30% by mass and water 70% by mass so that the solid content concentration was 12% by mass. C.) to prepare a solution of acrylic polyol alone, and the solution was applied to the surface of the polyester film subjected to only longitudinal stretching with Mayer bar # 5. Next, the film sample on which the coating layer (thickness 6.5 μm) was formed was allowed to stand for 30 seconds in a hot air circulating oven set at a temperature of 60 ° C., and then the film sample was taken out of the oven and pre-dried. Next, the sample was rotated by hand, set in a stretching apparatus (manufactured by Toyobo Engineering Co., Ltd.), placed in a hot air circulation oven at 100 ° C., and slowly stretched. The stretching operation was performed until the length before stretching was 4 times, and the stretching apparatus was taken out from the hot air circulation oven. Thereafter, the stretched coating film was observed with an optical microscope (magnification: 200 times), and the presence or absence of cracking due to stretching was determined according to the following criteria.
○: No cracks are observed.
Δ: Some cracks are observed (1 to 4).
X: 5 or more cracks or cracks are observed on the entire surface.

(1) Surface characteristics of coated film It is a value measured under the following conditions using a non-contact surface shape measurement system (VertScan R550H-M100). The average surface roughness (Sa) and the average length (RSm) of the roughness curve elements were measured using an average of 5 measurements, and the maximum protrusion height (P) was the maximum of 5 measurements.
(Measurement condition)
・ Measurement mode: WAVE mode ・ Objective lens: 50 × ・ 0.5 × Tube lens ・ Measurement area 187 × 139 μm (Sa, P measurement)
Measurement length (Lr: reference length): 187 μm (RSm measurement)

(2) Particle dispersibility evaluation of easy-slip coating layer (narrow field of view, VertScan measurement field of view 187 × 139 μm)
The maximum protrusion height (P) measured in the above (1) was used for judgment based on the following criteria.
○: Maximum protrusion height (P) is 0.2 μm or less ○ △: Maximum protrusion height (P) is larger than 0.2 μm and smaller than 0.3 μm.
Δ: Maximum protrusion height (P) is 0.3 μm or more

(3) Particle dispersibility evaluation of the easy-slip coating layer (wide field of view, visual field of view 600 mm × 420 mm)
Using LED lights (LED LENSER P5R.2 manufactured by LED LENSER) visually in a dark room, four release films for A4 size green sheet production are observed, and the particle aggregates that can be visually recognized are marked as follows. Judgment was made based on the following criteria.
◎: No particle aggregate ○: 1 to 3 particle aggregates
Δ: Four or more particle aggregates.

(4) Anti-powder resistance Friction fastness tester (RT-200, manufactured by Daiei Kagaku Seisakusho Co., Ltd.) is easily coated with a release film for green sheet production (3 cm (film width direction) x 20 cm (film longitudinal direction)). Attach so that the layer is on top, use aluminum foil (thickness 80 μm, arithmetic average surface roughness 0.03 μm) at the contact part of the load head (2 cm × 2 cm, 200 g) and the sample film, and make a round trip at a distance of 10 cm 10 reciprocations were performed at a speed of 2 seconds. The film obtained on the black mount was placed on it, and it was visually confirmed whether the powder had fallen.
○: No powder falling on the black mount.
(Triangle | delta): The slight powder fall can be confirmed on the whole black mount.

(5) Surface free energy Water (liquid) on the release surface of the release film using a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd .: fully automatic contact angle meter DM-701) under conditions of 25 ° C. and 50% RH. Droplets of 1.8 μL), diiodomethane (liquid proper amount 0.9 μL), and ethylene glycol (liquid proper amount 0.9 μL) were prepared and the contact angle was measured. As the contact angle, the contact angle 10 seconds after each solution was dropped onto the release film was employed. The contact angle data of water, diiodomethane, and ethylene glycol obtained by the above method was calculated from the “Kitazaki-Hataba” theory to determine the surface free energy dispersion component γsd, polar component γsp, and hydrogen bond component γsh of the release film, The total of each component was defined as the surface free energy γs. This calculation was performed using calculation software in the contact angle meter software (FAMAS).

(6) Unwinding charging of release film roll The release film for green sheet production obtained in each Example and each Comparative Example was wound into a roll having a width of 400 mm and a length of 5000 m to obtain a release film roll. The release film roll was stored in an environment of 40 ° C. and a humidity of 50% or less for 30 days, and the amount of charge when it was rewound at 100 m / min was measured using “KSD-0103” manufactured by Kasuga Electric. The amount of electrification was measured at every unwinding length of 500 M at 100 mm immediately after unwinding, and the average value was calculated.
○: Less than ± 3kV
○ △: ± 3kV or more and less than 5kV △: ± 5kV or more and less than 10kV
×: ± 10 kV or more

(7) Evaluation of pinhole and thickness variation of ceramic green sheet The following composition composed of materials is stirred and mixed and dispersed for 2 hours using a paint shaker using 2.0 mm glass beads as a dispersion medium to obtain a ceramic slurry. It was.
Toluene 22.5% by mass
Ethanol 22.5% by mass
Barium titanate 50 mass%
(HPBT-1 manufactured by Fuji Titanium)
Polyvinyl butyral 5% by mass
(SREK BH-3 manufactured by Sekisui Chemical Co., Ltd.)
Next, the slurry after drying is applied to the release surface of the release film sample using an applicator so that the dried slurry has a thickness of 0.5 μm, dried at 90 ° C. for 1 minute, and then the slurry surface and the smoothing coating layer surface are overlapped. After applying a load of 1 kg / cm ² for 1 minute, the release film was peeled off to obtain a ceramic green sheet.
In the central region in the film width direction of the obtained ceramic green sheet, light was applied from the opposite side of the ceramic slurry coating surface within a range of 25 cm ² , and the occurrence of pinholes through which light was transmitted was observed. Visual judgment was made.
A: No occurrence of pinholes, particularly good thickness variation B: No occurrence of pinholes, no particular problem in thickness variation Δ: Very little pinholes are generated, and thickness variations are slightly visible.
X: A little pinhole is generated and thickness variation is slightly noticeable.

(Preparation of polyethylene terephthalate pellets (PET (I)))
As the esterification reaction apparatus, a continuous esterification reaction apparatus comprising a three-stage complete mixing tank having a stirrer, a partial condenser, a raw material charging port and a product outlet was used. TPA (terephthalic acid) is 2 tons / hour, EG (ethylene glycol) is 2 moles per mole of TPA, antimony trioxide is made into an amount that makes Sb atoms 160 ppm with respect to the produced PET, and these slurries are esterified. Was continuously supplied to the first esterification reactor of the chemical reaction apparatus, and allowed to react at 255 ° C. at an average residence time of 4 hours at normal pressure. Next, the reaction product in the first esterification reaction can is continuously taken out of the system and supplied to the second esterification reaction can, and is distilled off from the first esterification reaction can in the second esterification reaction can. EG solution containing 8 mass% of EG with respect to the generated PET, and further containing EG solution containing magnesium acetate tetrahydrate in an amount of 65 ppm of Mg atoms relative to the generated PET, and 40 ppm of P atoms relative to the generated PET An EG solution containing a quantity of TMPA (trimethyl phosphate) was added and reacted at 260 ° C. at normal pressure for an average residence time of 1 hour. Next, the reaction product of the second esterification reaction can was continuously taken out of the system and supplied to the third esterification reaction can, and 39 MPa (400 kg / cm ² ) using a high pressure disperser (manufactured by Nippon Seiki Co., Ltd.). An average particle of 0.2 mass% of porous colloidal silica having an average particle diameter of 0.9 μm and an ammonium salt of polyacrylic acid adhered to 1 mass% of calcium carbonate, which was dispersed at an average number of treatments of 5 passes under the pressure of While adding 0.4% by mass of synthetic calcium carbonate having a diameter of 0.6 μm as an EG slurry of 10%, the reaction was carried out at 260 ° C. at an average residence time of 0.5 hours at normal pressure. The esterification reaction product produced in the third esterification reaction can was continuously supplied to a three-stage continuous polycondensation reaction apparatus to perform polycondensation, and sintered with a stainless steel fiber having a 95% cut diameter of 20 μm. After filtering with a filter, ultrafiltration was performed and extruded into water, and after cooling, it was cut into chips to obtain PET chips with an intrinsic viscosity of 0.60 dl / g (hereinafter referred to 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 above PET chip, a PET chip having an intrinsic viscosity of 0.62 dl / g containing no particles such as calcium carbonate and silica was obtained (hereinafter abbreviated as PET (II)).

(Manufacture of laminated film Z)
These PET chips were dried, melted at 285 ° C., melted at 290 ° C. with a separate melt extruder extruder, sintered with stainless steel fibers having a 95% cut diameter of 15 μm, and a 95% cut diameter Two-stage filtration of a filter obtained by sintering 15 μm stainless steel particles is performed and merged in a feed block, so that PET (I) becomes an anti-release surface side layer and PET (II) becomes a release surface side layer. And then 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 adhesion method, and unstretched with an intrinsic viscosity of 0.59 dl / g A polyethylene terephthalate sheet was obtained. The layer ratio was adjusted so that PET (I) / (II) = 60% / 40% in the discharge amount calculation of each extruder. Next, this unstretched sheet was heated with an infrared heater, and then stretched 3.5 times in the longitudinal direction at a roll temperature of 80 ° C. due to the speed difference between the rolls. Thereafter, the film was guided to a tenter and stretched 4.2 times in the transverse direction at 140 ° C. Subsequently, it heat-processed at 210 degreeC in the heat setting zone. Thereafter, a relaxation treatment of 2.3% was performed in the transverse direction at 170 ° C. to obtain a biaxially stretched polyethylene terephthalate film Z having a thickness of 31 μm. Sa of the release surface side layer of the obtained film Z was 2 nm, and Sa of the anti-release surface side layer was 28 nm.

(Production of acrylic polyol A-1)
In a four-necked flask equipped with a stirrer, reflux condenser, thermometer and nitrogen blowing tube, 77 parts by mass of methyl methacrylate (MMA), 100 parts by mass of hydroxyethyl methacrylate (HEMA), 33 parts by mass of methacrylic acid (MAA) And 490 mass parts of isopropyl alcohol (IPA) was prepared, and the inside of a flask was heated up to 80 degreeC, stirring. Stirring was performed for 3 hours while maintaining the inside of the flask at 80 ° C., and then 2,2-azobis-2-methyl-N-2-hydroxyethylpropionamide was added to the 0.5 part by mass flask. After performing nitrogen substitution while raising the temperature in the flask to 120 ° C., the mixture was stirred at 120 ° C. for 2 hours.
Subsequently, decompression operation of 1.5 kPa was performed at 120 ° C. to remove unreacted raw materials and solvent, and acrylic polyol was obtained. The flask was returned to atmospheric pressure and cooled to room temperature, and 840 parts by mass of an IPA aqueous solution (water content 50% by mass) was added and mixed. Then, triethylamine is added using a dropping funnel while stirring, and the acrylic polyol is neutralized until the pH of the solution is in the range of 5.5 to 7.5, and the acrylic polyol having a solid content concentration of 20% by mass. (A-1) was obtained. Table 1 shows the composition ratio, Tg, stretchability, and acid value of the acrylic polyol (A-1) measured by NMR.

(Production of acrylic polyols (A-2) to (A-13))
As shown in Table 1, MMA, St, SMA, HEMA, MAA, AA, IPA at the time of charging, the amount of the IPA aqueous solution at the time of dilution, and the production of acrylic polyol 1 except that the neutralizing agent was changed, Acrylic polyols (A-2) to (A-13) having a solid content concentration of 20% by mass were obtained. Table 1 shows the composition ratio, Tg, stretchability, and acid value of the acrylic polyols (A-2) to (A-13) measured by NMR. The composition ratios are MMA, St (styrene), SMA (stearyl methacrylate), l-1, l-2, l-3 (unit), HEMA, m (unit), MAA, AA (acrylic acid), respectively. Was expressed as n (unit).

(Polymerization of polyester resin B0-1)
In a stainless steel autoclave equipped with a stirrer, a thermometer, and a partial reflux condenser, 194.2 parts by weight of dimethyl terephthalate, 184.5 parts by weight of dimethyl isophthalate, 14.8 parts by weight of dimethyl-5-sodium sulfoisophthalate, 185.1 parts by mass of ethylene glycol, 185.1 parts by mass of neopentyl glycol, and 0.2 parts by mass of tetra-n-butyl titanate were charged, and a transesterification reaction was performed at a temperature of 160 ° C. to 220 ° C. over 4 hours. . Next, the temperature was raised to 255 ° C., and the pressure of the reaction system was gradually reduced, followed by reaction for 1 hour 30 minutes under a reduced pressure of 30 Pa to obtain a copolymerized polyester resin (B0-1). The obtained copolyester resin (B0-1) was light yellow and transparent. The reduced viscosity of the copolyester resin (B0-1) was measured and found to be 0.60 dl / g. The glass transition temperature by DSC was 65 ° C.

(Production of polyester aqueous dispersion B-1)
In a reactor equipped with a stirrer, a thermometer and a reflux device, 30 parts by mass of a polyester resin (B0-1) and 15 parts by mass of ethylene glycol-n-butyl ether were added and heated and stirred at 110 ° C. to dissolve the resin. After the resin was completely dissolved, 55 parts by mass of water was gradually added to the polyester solution while stirring. After the addition, the solution was cooled to room temperature while stirring to prepare a milky white polyester aqueous dispersion (B-1) having a solid content of 30% by mass.

(Polymer resin B0-2 polymerization)
In a stainless steel autoclave equipped with a stirrer, a thermometer, and a partial reflux condenser, 163 parts by mass of dimethyl terephthalate, 163 parts by mass of dimethyl isophthalate, 169 parts by mass of 1,4 butanediol, 324 parts by mass of ethylene glycol, and 0.5 parts by mass of tetra-n-butyl titanate was charged, and a transesterification reaction was performed from 160 ° C. to 220 ° C. over 4 hours.
Next, 14 parts by mass of fumaric acid and 203 parts by mass of sebacic acid were added, and the temperature was raised from 200 ° C. to 220 ° C. over 1 hour to carry out an esterification reaction. Next, the temperature was raised to 255 ° C., and the reaction system was gradually reduced in pressure, and then reacted for 1 hour 30 minutes under a reduced pressure of 29 Pa to obtain a hydrophobic copolyester resin (B0-2). The obtained hydrophobic copolyester resin (B0-2) was light yellow and transparent.

(Production of polyester aqueous dispersion B-2)
Subsequently, 60 parts by mass of this copolymer polyester resin (B0-2), 45 parts by mass of methyl ethyl ketone and 15 parts by mass of isopropyl alcohol were added to a reactor equipped with a stirrer, a thermometer, a reflux device and a quantitative dropping device. The mixture was heated and stirred at 65 ° C. to dissolve the resin. After the resin was completely dissolved, 24 parts by weight of maleic anhydride was added to the polyester solution.
Next, a solution obtained by dissolving 16 parts by mass of styrene and 1.5 parts by mass of azobisdimethylvaleronitrile in 19 parts by mass of methyl ethyl ketone was dropped into the polyester solution at 0.1 ml / min, and stirring was further continued for 2 hours. After sampling for analysis from the reaction solution, 8 parts by mass of methanol was added. Next, 300 parts by mass of water and 24 parts by mass of triethylamine were added to the reaction solution and stirred for 1 hour.
Thereafter, the internal temperature of the reactor was raised to 100 ° C., and methyl ethyl ketone, isopropyl alcohol and excess triethylamine were distilled off to obtain a pale yellow transparent polyester resin, and a uniform water dispersibility with a solid content concentration of 25% by mass. A polyester-based graft copolymer dispersion (B-2) was prepared. The obtained polyester-based graft copolymer had a glass transition temperature of 68 ° C.

(Production of polyurethane water dispersion C-1)
In a four-necked flask equipped with a stirrer, a Dimroth condenser, a nitrogen inlet tube, a silica gel drying tube, and a thermometer, 43.75 parts by mass of 4,4-dicyclohexylmethane diisocyanate, 12.85 parts by mass of dimethylolbutanoic acid, 153.41 parts by mass of polyhexamethylene carbonate diol having a number average molecular weight of 2000, 0.03 parts by mass of dibutyltin dilaurate, and 84.00 parts by mass of acetone as a solvent were added and stirred at 75 ° C. for 3 hours in a nitrogen atmosphere. It was confirmed that the liquid reached a predetermined amine equivalent. Next, after the temperature of this reaction liquid was lowered to 40 ° C., 8.77 parts by mass of triethylamine was added to obtain a polyurethane prepolymer solution. Next, 450 g of water was added to a reaction vessel equipped with a homodisper capable of high-speed stirring and adjusted to 25 ° C., while stirring and mixing at 2000 min ⁻¹ , the polyurethane prepolymer solution was added and dispersed in water. . Thereafter, a part of acetone and water was removed under reduced pressure to prepare a water-soluble polyurethane resin solution C-1 having a solid content of 37% by mass. The glass transition temperature of the obtained polyurethane resin was −30 ° C.

(Production of oxazoline-based crosslinking agent D-1)
A flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube and a thermometer was charged with 460.6 parts of isopropyl alcohol and heated to 80 ° C. while gently flowing nitrogen gas. A monomer mixture consisting of 126 parts of methyl methacrylate, 210 parts of 2-isopropenyl-2-oxazoline and 84 parts of methoxypolyethylene glycol acrylate prepared in advance, and 2,2′-azobis as a polymerization initiator. An initiator solution consisting of 21 parts of (2-methylbutyronitrile) (“ABN-E” manufactured by Nippon Hydrazine Kogyo Co., Ltd.) and 189 parts of isopropyl alcohol was dropped from the dropping funnel over 2 hours, and reacted. The reaction was continued for 5 hours after completion. During the reaction, nitrogen gas was kept flowing, and the temperature in the flask was kept at 80 ± 1 ° C. Thereafter, the reaction solution was cooled to obtain a resin (D-1) having an oxazoline group having a solid content concentration of 25%. The obtained resin (D-1) having an oxazoline group had an oxazoline group amount of 4.3 mmol / g, and the number average molecular weight measured by GPC (gel permeation chromatography) was 20,000.

(Production of oxazoline-based crosslinking agent D-2)
A resin (D-2) having an oxazoline group having a solid content concentration of 10% having a different composition (oxazoline group amount and molecular weight) was obtained in the same manner as the synthesis of the resin (D-1) having an oxazoline group. The obtained resin (D-2) having an oxazoline group had an oxazoline group amount of 7.7 mmol / g and a number average molecular weight measured by GPC of 40000.

(Production of carbodiimide crosslinking agent E-1)
A flask equipped with a stirrer, thermometer and reflux condenser was charged with 168 parts by mass of hexamethylene diisocyanate and 220 parts by mass of polyethylene glycol monomethyl ether (M400, average molecular weight 400), stirred at 120 ° C. for 1 hour, 26 parts by mass of 4′-dicyclohexylmethane diisocyanate and 3.8 parts by mass of 3-methyl-1-phenyl-2-phospholene-1-oxide (2% by mass based on the total isocyanate) were added as a carbodiimidization catalyst, and 185 under a nitrogen stream. Stir at 5 ° C. for a further 5 hours. The infrared spectrum of the reaction solution was measured, and it was confirmed that absorption at a wavelength of 2200 to 2300 cm ⁻¹ disappeared. It stood to cool to 60 degreeC, 567 mass parts of ion-exchange water was added, and the carbodiimide water-soluble resin (E-1) of 40 mass% of solid content was obtained.

(Production of isocyanate crosslinking agent F-1)
100 parts by mass of a polyisocyanate compound having an isocyanurate structure using hexamethylene diisocyanate as a raw material (manufactured by Asahi Kasei Chemicals, Duranate TPA) in a flask equipped with a stirrer, thermometer, reflux condenser, 55 parts by mass of propylene glycol monomethyl ether acetate, 30 parts by mass of polyethylene glycol monomethyl ether (average molecular weight 750) was charged and held at 70 ° C. for 4 hours in a nitrogen atmosphere. Thereafter, the reaction solution temperature was lowered to 50 ° C., and 47 parts by mass of methyl ethyl ketoxime was added dropwise. The infrared spectrum of the reaction solution was measured to confirm that the absorption of the isocyanate group had disappeared, and a block polyisocyanate aqueous dispersion (F-1) having a solid content of 75% by mass was obtained.

(Silica particle G-1)
Colloidal silica (manufactured by Nissan Chemical Co., Ltd., trade name MP2040, average particle size 200 nm, solid content concentration 40% by mass)

(Silica particle G-2)
Colloidal silica (manufactured by Nissan Chemical Co., Ltd., trade name Snowtex XL, average particle size 40 nm, solid content concentration 40 mass%)

(Silica particle G-3)
Colloidal silica (manufactured by Nissan Chemical Co., Ltd., trade name Snowtex ZL, average particle size 100 nm, solid content concentration 40% by mass)

(Silica particle G-4)
Colloidal silica (manufactured by Nissan Chemical Co., Ltd., trade name MP4540M, average particle size 450 nm, solid content concentration 40 mass%)

(Acrylic particle G-5)
Acrylic particle water dispersion (product of Nippon Shokubai, trade name MX100W, average particle size 150 nm, solid content concentration 10% by mass)

(Acrylic particle G-6)
Acrylic particle aqueous dispersion (product of Nippon Shokubai, trade name MX200W, average particle size 350 nm, solid content concentration 10% by mass)

(Acrylic particle G-7)
Acrylic particle water dispersion (made by Nippon Shokubai, trade name MX300W, average particle size 450 nm, solid content concentration 10% by mass)

(Releasing agent solution X-1)
Thermosetting amino alkyd resin (Tesfine 314, manufactured by Hitachi Chemical Co., Ltd., 100% by mass) and p-toluenesulfonic acid (Hitachi Chemical Co., Ltd., dryer 900, solid content 50% by mass) as a curing catalyst 2 parts by mass was diluted with a toluene / methyl ethyl ketone / heptane (= 3: 5: 2) solution to prepare a release agent solution having a solid content of 2% by mass.

(Releasing agent solution X-2)
100 parts by mass of UV curable silicone resin (Momentive UV9300, solid content concentration: 100% by mass) and 1 part by mass of curing catalyst bis (alkylphenyl) iodonium hexafluoroantimonate, toluene / methyl ethyl ketone / heptane (= 3: 5: 2) Diluted with a solution to prepare a release agent solution having a solid content of 2% by mass.

Example 1
(Adjustment of easy-slip coating solution 1)
Easy-slip coating solution 1 having the following composition was prepared.
(Easy-slip coating solution 1)
Water 41.86 parts by mass Isopropyl alcohol 35.00 parts by mass Acrylic polyol resin A-1 16.57 parts by mass (solid content concentration 20% by mass)
Oxazoline-based crosslinking agent D-1 5.68 parts by mass (solid content concentration 25% by mass)
Silica particle G-1 0.59 mass part (average particle diameter 200nm, solid content concentration 40 mass%)
Surfactant H-1 (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

(Manufacture of polyester film)
As a film raw material polymer, an intrinsic viscosity (solvent: phenol / tetrachloroethane = 60/40) is 0.62 dl / g, and PET resin pellets (PET (II)) containing substantially no particles are 133 Pa. It dried for 6 hours at 135 degreeC under pressure reduction. Thereafter, the sheet was supplied to an extruder, melted and extruded into a sheet at about 280 ° C., and rapidly cooled and solidified on a rotating cooling metal roll maintained at a surface temperature of 20 ° C. to obtain an unstretched PET sheet.

  This unstretched PET sheet was heated to 100 ° C. with a heated roll group and an infrared heater, and then stretched 3.5 times in the longitudinal direction with a roll group having a difference in peripheral speed to obtain a uniaxially stretched PET film.

  Next, the above easy-to-slip coating solution was applied to one side of a PET film with a bar coater and then dried at 80 ° C. for 15 seconds. The coating amount after final stretching and drying was adjusted to 0.1 μm. Subsequently, the film was stretched 4.0 times in the width direction at 150 ° C. with a tenter, and heated at 230 ° C. for 0.5 seconds with the length in the width direction fixed, and further at 230 ° C. for 10 seconds. % In the width direction, and an in-line coated polyester film having a thickness of 31 μm was obtained.

(Formation of release coating layer)
The release agent solution X-1 was applied to the surface of the inline-coated polyester film obtained above on the surface opposite to the easy-coated layer laminated surface with a reverse gravure coater so that the thickness after drying was 0.1 μm, and then Then, it was dried with hot air at 130 ° C. for 30 seconds to form a release coating layer to obtain a release film for producing an ultrathin layer ceramic green sheet. The winding property and other process passing properties and handling properties were excellent with no particular problems. After winding up as a roll, unwinding electrification when it is unwound for ceramic sheet coating is also low, making it possible to suppress the adhesion of environmental foreign substances and to produce high quality ceramic capacitors without reducing the yield of ceramic capacitors I was able to.

(Example 2)
Except for using the easy-to-slip coating solution 2 in which the crosslinking agent in the easy-to-slip coating solution 1 used in Example 1 was changed to a carbodiimide-based crosslinking agent E-1 (solid content concentration 40% by mass), the same as in Example 1 Thus, a release film for producing ultrathin ceramic green sheets was obtained.
(Easy-slip coating solution 2)
Water 43.99 parts by mass Isopropyl alcohol 35.00 parts by mass Acrylic polyol resin A-1 16.57 parts by mass (solid content concentration 20% by mass)
Carbodiimide-based crosslinking agent E-1 3.55 parts by mass (solid content concentration 40% by mass)
Silica particle G-1 0.59 mass part (average particle diameter 200nm, solid content concentration 40 mass%)
Surfactant H-1 (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

(Example 3)
Except for using the easy-to-slip coating solution 3 in which the crosslinking agent in the easy-to-slip coating solution 1 used in Example 1 was changed to oxazoline-based crosslinking agent D-2 (solid content concentration 10% by mass), the same as in Example 1 Thus, a release film for producing ultrathin ceramic green sheets was obtained.
(Easy-slip coating solution 3)
Water 33.34 parts by mass Isopropyl alcohol 35.00 parts by mass Acrylic polyol resin A-1 16.57 parts by mass (solid content concentration 20% by mass)
Oxazoline-based crosslinking agent D-2 14.20 parts by mass (solid content concentration 10% by mass)
Silica particle G-1 0.59 mass part (average particle diameter 200nm, solid content concentration 40 mass%)
Surfactant H-1 (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

Example 4
A polyester film was obtained in the same manner as in Example 1 except that the easy-to-slip coating liquid 1 was changed to the following easy-to-slip coating liquid 4.
(Easy-slip coating solution 4)
Water 43.28 parts by mass Isopropyl alcohol 35.00 parts by mass Acrylic polyol resin A-1 9.47 parts by mass (solid content concentration 20% by mass)
11.36 parts by mass of oxazoline-based crosslinking agent D-1 (solid content concentration: 25% by mass)
Silica particle G-1 0.59 mass part (average particle diameter 200nm, solid content concentration 40 mass%)
Surfactant H-1 (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

(Example 5)
A polyester film was obtained in the same manner as in Example 1 except that the slippery coating liquid 1 was changed to the slippery coating liquid 5 described below.
(Easy-slip coating solution 5)
Water 41.15 parts by mass Isopropyl alcohol 35.00 parts by mass Acrylic polyol resin A-1 20.12 parts by mass (solid content concentration 20% by mass)
Oxazoline-based crosslinking agent D-1 2.84 parts by mass (solid content concentration: 25% by mass)
Silica particle G-1 0.59 mass part (average particle diameter 200nm, solid content concentration 40 mass%)
Surfactant H-1 (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

(Example 6)
Example 1 except that acrylic polyol A-1 (solid content concentration 20% by mass) in easy-slip coating solution 1 used in Example 1 was changed to acrylic polyol A-2 (solid content concentration 20% by mass). Similarly, a release film for producing an ultrathin layer ceramic green sheet was obtained.

(Example 7)
Example 1 except that acrylic polyol A-1 (solid content concentration 20% by mass) in easy-slip coating solution 1 used in Example 1 was changed to acrylic polyol A-3 (solid content concentration 20% by mass). Similarly, a release film for producing an ultrathin layer ceramic green sheet was obtained.

(Example 8)
Example 1 with the exception that acrylic polyol A-1 (solid content concentration 20% by mass) in easy-slip coating solution 1 used in Example 1 was changed to acrylic polyol A-4 (solid content concentration 20% by mass). Similarly, a release film for producing an ultrathin layer ceramic green sheet was obtained.

Example 9
Example 1 except that acrylic polyol A-1 (solid content concentration 20% by mass) in easy-slip coating solution 1 used in Example 1 was changed to acrylic polyol A-5 (solid content concentration 20% by mass). Similarly, a release film for producing an ultrathin layer ceramic green sheet was obtained.

(Example 10)
Example 1 and Example 1 except that acrylic polyol A-1 (solid content concentration 20% by mass) in easy-slip coating solution 1 used in Example 1 was changed to acrylic polyol A-6 (solid content concentration 20% by mass). Similarly, a release film for producing an ultrathin layer ceramic green sheet was obtained.

(Example 11)
Example 1 and Example 1 except that acrylic polyol A-1 (solid content concentration 20% by mass) in easy-slip coating liquid 1 used in Example 1 was changed to acrylic polyol A-7 (solid content concentration 20% by mass). Similarly, a release film for producing an ultrathin layer ceramic green sheet was obtained.

(Example 12)
Example 1 and Example 1 except that the acrylic polyol A-1 (solid content concentration 20% by mass) in the easy-to-slip coating solution 1 used in Example 1 was changed to acrylic polyol A-8 (solid content concentration 20% by mass). Similarly, a release film for producing an ultrathin layer ceramic green sheet was obtained.

(Example 13)
Example 1 and Example 1 except that acrylic polyol A-1 (solid content concentration 20% by mass) in easy-slip coating solution 1 used in Example 1 was changed to acrylic polyol A-9 (solid content concentration 20% by mass). Similarly, a release film for producing an ultrathin layer ceramic green sheet was obtained.

(Example 14)
Example 1 except that acrylic polyol A-1 (solid content concentration 20% by mass) in easy-slip coating solution 1 used in Example 1 was changed to acrylic polyol A-10 (solid content concentration 20% by mass). Similarly, a release film for producing an ultrathin layer ceramic green sheet was obtained.

(Example 15)
Example 1 except that acrylic polyol A-1 (solid content concentration 20% by mass) in easy-slip coating solution 1 used in Example 1 was changed to acrylic polyol A-11 (solid content concentration 20% by mass). Similarly, a release film for producing an ultrathin layer ceramic green sheet was obtained.

(Example 16)
Example 1 and Example 1 except that acrylic polyol A-1 (solid content concentration 20% by mass) in easy-slip coating liquid 1 used in Example 1 was changed to acrylic polyol A-12 (solid content concentration 20% by mass). Similarly, a release film for producing an ultrathin layer ceramic green sheet was obtained.

(Example 17)
A release film for producing an ultrathin layer ceramic green sheet was obtained in the same manner as in Example 1 except that the easy-slip coating solution 1 was changed to the following easy-slip coating solution 17.
(Easy-slip coating solution 17)
Water 41.74 parts by mass Isopropyl alcohol 35.00 parts by mass Acrylic polyol resin A-10 16.57 parts by mass (solid content concentration 20% by mass)
Oxazoline-based crosslinking agent D-1 5.68 parts by mass (solid content concentration 25% by mass)
Silica particle G-1 0.59 mass part (average particle diameter 200nm, solid content concentration 40 mass%)
Silica particle G-4 0.12 parts by mass (average particle size 450 nm, solid content concentration 40% by mass)
Surfactant H-1 (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

(Example 18)
A release film for producing an ultrathin layer ceramic green sheet was obtained in the same manner as in Example 1 except that the easy-slip coating solution 1 was changed to the following easy-slip coating solution 18.
(Easy-slip coating solution 18)
Water 41.15 parts by mass Isopropyl alcohol 35.00 parts by mass Acrylic polyol resin A-10 16.57 parts by mass (solid content concentration 20% by mass)
Oxazoline-based crosslinking agent D-1 5.68 parts by mass (solid content concentration 25% by mass)
Silica particle G-2 1.18 parts by mass (average particle size 40 nm, solid content concentration 40% by mass)
Silica particle G-4 0.12 parts by mass (average particle size 450 nm, solid content concentration 40% by mass)
Surfactant H-1 (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

(Example 19)
A release film for producing an ultrathin layer ceramic green sheet was obtained in the same manner as in Example 1 except that the easy-slip coating solution 1 was changed to the following easy-slip coating solution 19.
(Easy-slip coating solution 19)
Water 41.27 parts by mass Isopropyl alcohol 35.00 parts by mass Acrylic polyol resin A-10 16.57 parts by mass (solid content concentration 20% by mass)
Oxazoline-based crosslinking agent D-1 5.68 parts by mass (solid content concentration 25% by mass)
Silica particle G-3 1.18 parts by mass (average particle size 100 nm, solid content concentration 40% by mass)
Surfactant H-1 (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

(Example 20)
A release film for producing an ultrathin layer ceramic green sheet was obtained in the same manner as in Example 1 except that the easy-slip coating solution 1 was changed to the following easy-slip coating solution 20.
(Easy-slip coating solution 20)
Water 40.09 parts by mass Isopropyl alcohol 35.00 parts by mass Acrylic polyol resin A-10 16.57 parts by mass (solid content concentration 20% by mass)
Oxazoline-based crosslinking agent D-1 5.68 parts by mass (solid content concentration 25% by mass)
Acrylic particle G-5 2.37 parts by mass (average particle size 150 nm, solid content concentration 10% by mass)
Surfactant H-1 (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

(Example 21)
A release film for producing an ultrathin ceramic green sheet was obtained in the same manner as in Example 1 except that the release coating layer was formed as described below.
(Formation of release coating layer)
The release agent solution X-2 was applied to the obtained inline-coated polyester film with a reverse gravure coater so that the thickness after drying was 0.1 μm, then dried with hot air at 90 ° C. for 30 seconds, Ultraviolet irradiation (300 mJ / cm ² ) was performed with an electrode lamp (H bulb manufactured by Heraeus Co., Ltd.) to form a release coating layer to obtain a release film for producing an ultrathin ceramic green sheet.

(Example 22)
Example 1 except that acrylic polyol A-1 (solid content concentration 20% by mass) in easy-slip coating solution 1 used in Example 1 was changed to acrylic polyol A-13 (solid content concentration 20% by mass). Similarly, a release film for producing an ultrathin layer ceramic green sheet was obtained.

(Example 23)
A release film for producing an ultrathin layer ceramic green sheet was obtained in the same manner as in Example 1 except that the easy-slip coating solution 1 was changed to the following easy-slip coating solution 22.
(Easy-slip coating liquid 22)
Water 41.39 parts by mass Isopropyl alcohol 35.00 parts by mass Acrylic polyol resin A-13 16.57 parts by mass (solid content concentration 20% by mass)
Oxazoline-based crosslinking agent D-1 5.68 parts by mass (solid content concentration 25% by mass)
Silica particle G-1 0.59 mass part (average particle diameter 200nm, solid content concentration 40 mass%)
Acrylic particle G-6 0.47 mass part (average particle diameter 350nm, solid content concentration 10 mass%)
Surfactant H-1 (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

(Example 24)
A release film for producing an ultrathin layer ceramic green sheet was obtained in the same manner as in Example 1 except that the easy-slip coating solution 1 was changed to the following easy-slip coating solution 23.
(Easy-slip coating solution 23)
Water 41.39 parts by mass Isopropyl alcohol 35.00 parts by mass Acrylic polyol resin A-13 16.57 parts by mass (solid content concentration 20% by mass)
Oxazoline-based crosslinking agent D-1 5.68 parts by mass (solid content concentration 25% by mass)
Silica particle G-1 0.59 mass part (average particle diameter 200nm, solid content concentration 40 mass%)
Acrylic particle G-7 0.47 mass part (average particle diameter 450nm, solid content concentration 10 mass%)
Surfactant H-1 (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

(Example 25)
A release film for producing an ultrathin layer ceramic green sheet was obtained in the same manner as in Example 1 except that the easy-slip coating solution 1 was changed to the following easy-slip coating solution 24.
(Easy-slip coating solution 24)
Water 39.62 parts by mass Isopropyl alcohol 35.00 parts by mass Acrylic polyol resin A-13 16.57 parts by mass (solid content concentration 20% by mass)
Oxazoline-based crosslinking agent D-1 5.68 parts by mass (solid content concentration 25% by mass)
Acrylic particle G-5 2.37 parts by mass (average particle size 150 nm, solid content concentration 10% by mass)
Acrylic particle G-7 0.47 mass part (average particle diameter 450nm, solid content concentration 10 mass%)
Surfactant H-1 (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

(Comparative Example 1)
A polyester film was obtained in the same manner as in Example 1 except that the easy-to-slip coating solution 1 was changed to the following easy-to-slip coating solution 25.
(Easy-slip coating solution 25)
Water 48.33 parts by mass Isopropyl alcohol 35.00 parts by mass Polyester water dispersion B-1 15.78 parts by mass (solid content concentration 30% by mass)
Silica particle G-1 0.59 mass part (average particle diameter 200nm, solid content concentration 40 mass%)
Surfactant (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

(Comparative Example 2)
A polyester film was obtained in the same manner as in Example 1 except that the slippery coating liquid 1 was changed to the slippery coating liquid 26 described below.
(Easy-slip coating solution 26)
Water 45.18 parts by weight Isopropyl alcohol 35.00 parts by weight Polyester water dispersion B-2 18.93 parts by weight (solid content concentration 25% by weight)
Silica particle G-1 0.59 mass part (average particle diameter 200nm, solid content concentration 40 mass%)
Surfactant (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

(Comparative Example 3)
A polyester film was obtained in the same manner as in Example 1 except that the slippery coating liquid 1 was changed to the slippery coating liquid 27 described below.
(Easy-slip coating liquid 27)
Water 51.32 parts by weight Isopropyl alcohol 35.00 parts by weight Polyurethane resin water dispersion C-1 12.79 parts by weight (solid content concentration 37% by weight)
Silica particle G-1 0.59 mass part (average particle diameter 200nm, solid content concentration 40 mass%)
Surfactant (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

(Comparative Example 4)
A polyester film was obtained in the same manner as in Example 1 except that the slippery coating liquid 1 was changed to the slippery coating liquid 28 described below.
(Easy-slip coating liquid 28)
Water 47.39 parts by mass Isopropyl alcohol 35.00 parts by mass Polyester water dispersion B-1 11.04 parts by mass (solid content concentration 30% by mass)
Oxazoline-based crosslinking agent D-1 5.68 parts by mass (solid content concentration 25% by mass)
Silica particle G-1 0.59 mass part (average particle diameter 200nm, solid content concentration 40 mass%)
Surfactant (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

(Comparative Example 5)
A polyester film was obtained in the same manner as in Example 1 except that the slippery coating liquid 1 was changed to the slippery coating liquid 29 described below.
(Easy-slip coating solution 29)
Water 49.51 parts by weight Isopropyl alcohol 35.00 parts by weight Polyester water dispersion B-1 11.04 parts by weight (solid content concentration 30% by weight)
Carbodiimide-based crosslinking agent E-1 3.55 parts by mass (solid content concentration 40% by mass)
Silica particle G-1 0.59 mass part (average particle diameter 200nm, solid content concentration 40 mass%)
Surfactant (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

(Comparative Example 6)
A polyester film was obtained in the same manner as in Example 1 except that the easy-slip coating solution 1 was changed to the following easy-slip coating solution 30.
(Easy-slip coating solution 30)
Water 40.44 parts by mass Isopropyl alcohol 35.00 parts by mass Acrylic polyol resin A-1 23.67 parts by mass (solid content concentration 20% by mass)
Silica particle G-1 0.59 mass part (average particle diameter 200nm, solid content concentration 40 mass%)
Surfactant H-1 (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

(Comparative Example 7)
A polyester film was obtained in the same manner as in Example 1 except that the easy-slip coating solution 1 was changed to the following easy-slip coating solution 31.
(Easy-slip coating solution 31)
Water 45.65 parts by mass Isopropyl alcohol 35.00 parts by mass Acrylic polyol resin A-1 16.57 parts by mass (solid content concentration 20% by mass)
Isocyanate crosslinking agent F-1 1.89 parts by mass (solid content concentration 75% by mass)
Silica particle G-1 0.59 mass part (average particle diameter 200nm, solid content concentration 40 mass%)
Surfactant H-1 (fluorine-based, solid content concentration 10% by mass) 0.30 parts by mass

(Comparative Example 8)
As the film for forming the release coating layer, it was carried out except that it was changed to E5000-25 μm (manufactured by Toyobo Co., Ltd.) instead of the inline coating film having a slippery coating layer on one surface prepared in Example 1. A release film for producing a ceramic green sheet was obtained in the same manner as in Example 1. E5000 contained particles inside the film, and Sa on both surfaces was 0.031 μm.

(Comparative Example 9)
As a film for forming the mold release coating layer, the same as in Example 1 except that instead of the inline coating film having the slippery coating layer on one surface prepared in Example 1, it was changed to the laminated film Z and used. In this way, a release film for producing a ceramic green sheet was obtained. A release coating layer was provided on the surface (layer containing no particles) from which the PET (II) pellets of the laminated film Z were discharged.

  Tables 2 and 3 show the evaluation results of the examples and comparative examples.

  In Table 2 above, the resin, the crosslinking agent, the particles, and the surfactant in the easy-to-slip coating liquid are described with each composition as a solid part by mass, and the resin and cross-linking agent that are present in the easy-to-slip coating liquid. The total of the solid parts by mass of the particles and the surfactant becomes the mass part of the total solids of the easy-to-slip coating layer. By dividing by the mass part of the total solid content of the coating layer, the mass percentage in the total solid text in the easy-to-slip coating layer of the resin, the crosslinking agent, the particles and the surfactant can be obtained.

In Examples 1 to 25, since the unwinding charge when the roll is re-rolled after the mold release processing is low and environmental foreign substances are difficult to adhere, a high quality ceramic capacitor is produced without reducing the yield of the ceramic capacitor. I was able to. As a release film, a polyester film substantially free of inorganic particles is used as a base material, a release coating layer is provided on one surface of the base material, and particles are contained on the other surface. And a composition containing at least one crosslinking agent selected from an acrylic resin and an oxazoline-based crosslinking agent or a carbodiimide-based crosslinking agent is cured. The crosslink density of the coating layer is high and the deformation amount of the easy-sliding coating layer is small. It is thought that the amount of electrification could be suppressed because the contact area was reduced when the release layer and the easy-sliding layer were peeled off when the film roll that had been subjected to release processing was unwound.
On the other hand, in Comparative Examples 1-7, the slippery coating formed by hardening | curing the composition containing the acrylic resin prescribed | regulated by this invention, and the at least 1 sort (s) of crosslinking agent chosen from an oxazoline type crosslinking agent or a carbodiimide type crosslinking agent. Since it is not a layer, the crosslink density of the slippery coating layer is lowered, and the amount of deformation of the slippery coating layer is increased. It is thought that the unwinding charge was increased because the contact area was increased when the release layer and the easy-sliding layer were peeled off when the film roll that had been subjected to release processing was unwound. In Comparative Examples 8 and 9, although the unwinding charge is low, it does not have the easy-slip coating layer defined in the present invention, and the surface roughness of the easy-slip surface is large, so that pinholes are generated in the ceramic sheet. did.

According to the present invention, even when the ceramic green sheet is thinned, the mold release for producing the ceramic green sheet can achieve both prevention of pinholes and partial thickness variations, and prevention of adhesion of environmental foreign substances due to charging. A film can be provided. Further, by using the release film for producing a ceramic green sheet of the present invention, an extremely thin ceramic green sheet can be obtained, and a minute ceramic capacitor can be produced efficiently.

Claims (8)

  An easy-sliding coating layer comprising a polyester film substantially free of inorganic particles as a base material, having a release coating layer on one surface of the base material, and containing particles on the other surface A release film for producing a ceramic green sheet, in which an easy-slip coating layer is cured with a composition containing an acrylic resin and at least one crosslinking agent selected from an oxazoline crosslinking agent or a carbodiimide crosslinking agent.   The release film for producing a ceramic green sheet according to claim 1, wherein the glass transition temperature of the acrylic resin is 50 ° C. or higher and 110 ° C. or lower.   The release film for producing a ceramic green sheet according to claim 1 or 2, wherein the acid value of the acrylic resin is 40 mgKOH / g or more and 400 mgKOH / g or less.   The surface average roughness (Sa) of the easy-coating layer is 1 nm or more and 25 nm or less, the maximum protrusion height (P) is 60 nm or more and 500 nm or less, and the average length (RSm) of the roughness curve element is 10 μm or less. Item 4. A release film for producing a ceramic green sheet according to any one of Items 1 to 3.   The release film for producing a ceramic green sheet according to any one of claims 1 to 4, wherein the thickness of the easy-slip coating layer is 0.001 µm to 2 µm.   The manufacturing method of the ceramic green sheet using the release film for ceramic green sheet manufacture in any one of Claims 1-5.   The method for producing a ceramic green sheet according to claim 6, wherein the thickness of the ceramic green sheet to be produced is 0.2 µm or more and 2.0 µm or less. The manufacturing method of the ceramic capacitor which employ | adopts the manufacturing method of the ceramic green sheet of Claim 6 or 7.