KR20210036416A - Release film for ceramic green sheet manufacturing - Google Patents

Abstract

The present invention provides a release film for forming a ceramic green sheet which is excellent in peelability and is unlikely to cause damage such as cracks in a half-cut test with respect to an ultrathin ceramic green sheet to be molded.
The present invention is a release film in which a release layer is laminated directly on at least one side of a polyester film or through another layer, wherein the release layer is an energy ray-curable compound (I), a polyester resin (II), And a coating film containing at least a release component (III) is cured, and the polyester resin (II) is a release film for producing a ceramic green sheet containing an ester structural unit derived from a 5-sodium sulfoisophthalic acid component.

Description

Release film for ceramic green sheet manufacturing

The present invention relates to a release film for manufacturing an ultra-thin layer ceramic green sheet, and in detail, it is possible to manufacture a product in which the occurrence of process defects due to unevenness of pinholes and thickness or peeling defects in the manufacture of the ultra-thin layer ceramic green sheet is suppressed. It relates to a release film for manufacturing an ultra-thin ceramic green sheet.

Conventionally, a release film in which a polyester film is used as a substrate and a release layer is laminated thereon is used for forming a ceramic green sheet such as a multilayer ceramic capacitor (hereinafter referred to as MLCC) and a ceramic substrate. In recent years, along with the miniaturization and increase in capacity of multilayer ceramic capacitors, the thickness of the ceramic green sheet also tends to become thinner. The ceramic green sheet is formed by applying a slurry containing a ceramic component such as barium titanate and a binder resin to a mold release film and drying it. After the electrode is printed on the molded ceramic green sheet and peeled from the release film, the ceramic green sheet is laminated, pressed, cut, fired, and external electrodes are applied to manufacture a multilayer ceramic capacitor. Until now, in the case of forming a ceramic green sheet on the surface of the release layer of a polyester film, microscopic projections on the surface of the release layer affect the formed ceramic green sheet, causing defects such as cissing and pinholes. There was a problem that it became easier. Therefore, various methods have been developed for realizing the surface of the release layer having excellent flatness (see, for example, Patent Document 1).

However, in recent years, further thinning of the ceramic green sheet has progressed, and a ceramic green sheet having a thickness of 1.0 µm or less, more specifically 0.2 µm to 1.0 µm has been required. For this reason, higher smoothness has been demanded on the surface of the release layer. In addition, since the strength of the ceramic green sheet decreases as the ceramic green sheet becomes thinner, it is desirable not only to smooth the surface of the release layer, but also to lower and uniform the peeling force when the ceramic green sheet is peeled from the release film. In addition, when peeling the ceramic green sheet from the release film, it has become desirable to reduce the load applied to the ceramic green sheet as much as possible so as not to damage the ceramic green sheet.

As a method on the side of the release layer to smooth the surface of the release layer and suppress the load on the ceramic green sheet during peeling, the crosslinking density of the release layer is increased and the elastic modulus is improved by using an active energy ray curing component in the release layer of the release film. By doing so, measures to lighten the peeling force by suppressing the elastic deformation of the release layer during peeling of the ceramic green sheet have been studied (for example, see Patent Documents 2 and 3). However, in this method, since the smoothness is too high, surface peeling occurs, the peeling force becomes heavy, and cracks may occur in the green sheet. In addition, when processing ultra-thin ceramic green sheets, if the smooth surface comes into contact with the smoothing roll or rubber roll for tension control of the coating equipment, the sliding properties of the roll and the smooth surface are insufficient and the tension control becomes unstable. There was a problem that the smoothness was lowered.

Therefore, a release film excellent in balance of smoothness and uniform peelability has been reported by setting it as a polyester film having an appropriate large protrusion serving as a trigger (peel start point) at the time of initiation of peeling (e.g., Patent Literature 4). However, in the case of a filler mixed with PET, coarse protrusions due to filler aggregation cannot be completely removed, and there is a problem that causes a defect in the product. In particular, in the ultra-thin ceramic green sheet, since the inorganic filler used as a ceramic material has a particle diameter of about 60 nm to 800 nm (for example, see Patent Documents 5 and 6), a film such as that described in Patent Document 4 is used. , There was a problem that a local hole was generated on the peeling surface.

Japanese Unexamined Patent Publication No. 2000-117899 International Publication No. 2013/145864 International Publication No. 2013/145865 International Publication No. 2014/203702 Japanese Unexamined Patent Publication No. 2016-127120 Japanese Unexamined Patent Publication No. 2017-081805

Therefore, the inventors of the present invention have conducted a thorough study, and as a result, by forming surface irregularities due to low protrusions on the surface of the release layer, the above-mentioned heavy peeling, reduction in processing aptitude, and occurrence of defect factors can be suppressed at the same time. I confirmed that there is. Further, an object of the present invention is to provide a release film for forming a ceramic green sheet which is excellent in peelability and is unlikely to cause damage such as cracks in a half-cut test with respect to an ultrathin ceramic green sheet to be molded.

That is, the present invention has the following configuration.

1. A release film in which a release layer is laminated directly on at least one side of a polyester film or through another layer, wherein the release layer is an energy ray-curable compound (I), a polyester resin (II), and a release film. A release film for producing a ceramic green sheet, wherein a coating film containing at least component (III) is cured, and the polyester resin (II) contains an ester structural unit derived from a 5-sodium sulfoisophthalic acid component.

2. The release layer has a phase-separated structure in which the energy ray-curable compound (I) is used as the sea component and the polyester resin (II) is used as the island component, and has surface irregularities. film.

3. The release film for producing a ceramic green sheet according to the first or second above, wherein the release layer does not contain substantially inorganic particles.

4. The release film for producing a ceramic green sheet according to any one of the first to third items, wherein the energy ray-curable compound (I) is a (meth)acrylic acid ester having three or more acryloyl groups in one molecule.

5. The release film for producing a ceramic green sheet according to any one of the first to fourth above, wherein the thickness of the release layer is 0.2 to 3.5 µm.

6. The release film for producing a ceramic green sheet according to any one of the first to fifth items, wherein the region surface average roughness (Sa) of the release layer is 5 to 40 nm.

7. The release film for producing a ceramic green sheet according to any one of the first to sixth above, wherein the maximum protrusion height (Rp) on the surface of the release layer is 60 nm or less.

8. A method for manufacturing a ceramic green sheet for forming a ceramic green sheet using the release film for producing a ceramic green sheet according to any one of the above 1 to 7, wherein the formed ceramic green sheet has a thickness of 0.2 µm to 1.0 µm. Method of manufacturing a ceramic green sheet.

According to the release film for producing a ceramic green sheet of the present invention, compared with the release film for producing a conventional ceramic green sheet, the peeling force is not too heavy, the workability is excellent, and the release layer has no protrusions, so the thickness to be formed is 1 μm or less. With respect to such an ultra-thin ceramic green sheet, it has become possible to provide a release film for ceramic green sheet production that is unlikely to cause damage such as cracks in a half-cut test.

1 is an electron micrograph of the surface of a release layer of the present invention (Example 1).
Fig. 2 is an electron micrograph of the surface of a release layer of the present invention (Example 2).

Hereinafter, the present invention will be described in detail.

(Polyester film)

The polyester constituting the polyester film used as the base material in the release film of the present invention is not particularly limited, and a film formed of polyester that is generally used as the release film base material can be used, but preferably, aromatic It is preferable that it is a crystalline linear saturated polyester composed of a dibasic acid component and a diol component, such as polyethylene terephthalate, polyethylene-2,6-naphthalate, polybutylene terephthalate, and polytrimethylene terephthalate. Alternatively, a copolymer containing the constituent components of these resins as a main component is more suitable, and in particular, a polyester film formed from polyethylene terephthalate is suitable. In polyethylene terephthalate, the repeating unit of ethylene terephthalate is preferably 90 mol% or more, more preferably 95 mol% or more, and a small amount of other dicarboxylic acid components and diol components may be copolymerized, but from the viewpoint of cost, terephthalic acid And ethylene glycol is preferred. Moreover, well-known additives, such as an antioxidant, a light stabilizer, an ultraviolet absorber, a crystallizing agent, etc. may be added within the range which does not impair the effect of the film of this invention. The polyester film is preferably a biaxially stretched polyester film for reasons such as high modulus of elasticity in both directions.

The intrinsic viscosity of the polyethylene terephthalate film is preferably 0.50 to 0.70 dl/g, more preferably 0.52 to 0.62 dl/g. When the intrinsic viscosity is 0.50 dl/g or more, fracture is less likely to occur in the stretching step, which is preferable. On the contrary, if it is 0.70 dl/g or less, it is preferable because it has good cutting properties when cutting to a predetermined product width, and dimensional defects do not occur. In addition, it is preferable to sufficiently vacuum-dry the raw material.

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

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

The polyester film preferably has a thickness of 12 to 50 µm, more preferably 12 to 38 µm, and more preferably 15 to 31 µm. When the thickness of the film is 12 µm or more, it is preferable because there is no fear of being deformed by heat during the production of the film, the processing step of the release layer, or the molding of the ceramic green sheet. On the other hand, if the thickness of the film is 50 μm or less, the amount of the film to be discarded after use is not extremely large, which is preferable in reducing the environmental load, and furthermore, since the material per area of the release film to be used is reduced. It is also desirable from an economic point of view.

The polyester film base material may be a single layer or a multilayer of two or more layers, but is preferably a laminated polyester film having a surface layer A substantially free of inorganic particles on at least one side. In the case of a laminated polyester film having a multilayer structure of two or more layers, it is preferable to have a surface layer B capable of containing particles or the like on the opposite surface of the surface layer A substantially containing no inorganic particles. In the lamination configuration, if the layer on the side to which the release layer is applied is the surface layer A, the layer on the opposite side is the surface layer B, and the other deep layers are the deep layer C, the layer configuration in the thickness direction is the release layer/surface layer. A laminated structure, such as A/surface layer B, or a release layer/surface layer A/deep layer C/surface layer B, is mentioned. Naturally, the depth C may be composed of a plurality of layers. Further, the surface layer B may not contain particles. In that case, it is preferable to provide a coat layer (D) containing particles and a binder on the surface layer B in order to impart a slip property for winding up the film in a roll shape.

In the polyester film base material in the present invention, it is preferable that the surface layer A forming the surface to which the release layer is applied does not contain substantially inorganic particles. At this time, the area surface average roughness (Sa) of the surface layer A is preferably 7 nm or less. When Sa is 7 nm or less, even if the release layer has a thickness of 2.0 µm or less, or even a thin film such as 0.5 µm or less, it is preferable that pinholes or the like are hardly generated during molding of the super-thin ceramic green sheet to be laminated. It can be said that the smaller the area surface average roughness (Sa) of the surface layer A is, the more preferable it is, but it may be 0.1 nm or more. However, in the case of providing an anchor coat layer or the like described later on the surface layer A, it is preferable that the coat layer does not contain substantially inorganic particles, and the area surface average roughness (Sa) after lamination of the coat layer is preferably within the above range. . In the present invention, the term "substantially free of inorganic particles" is defined as being 50 ppm or less, preferably 10 ppm or less, and most preferably less than the detection limit when the inorganic elements are quantified by fluorescence X-ray analysis. Content. This is because even if inorganic particles are not actively added to the film, contaminants derived from foreign substances or dirt adhered to the line or device in the manufacturing process of the raw resin or film may be peeled off and mixed into the film. .

In the case where the polyester film base material in the present invention is a laminated film, the surface layer B forming the opposite surface to the surface layer A to which the release layer is applied contains particles from the viewpoint of the sliding property of the film and the ease of removal of air. It is preferable to do, and in particular, it is preferable to contain silica particles and/or calcium carbonate particles. It is preferable that the content of the particles contained is 5000 to 15000 ppm in total of the particles in the surface layer B. At this time, the area surface average roughness Sa of the surface layer B is preferably in the range of 1 to 40 nm. More preferably, it is a range of 5 to 35 nm. When the sum of the silica particles and/or calcium carbonate particles of the surface layer B is 5000 ppm or more and Sa is 1 nm or more, air can be evenly released when the film is rolled up in a roll shape, and the wound appearance is good. By good planarity, it becomes suitable for manufacture of an ultra-thin ceramic green sheet. In addition, when the total of silica particles and/or calcium carbonate particles is 15000 ppm or less and Sa is 40 nm or less, agglomeration of the lubricant is difficult to occur, and coarse projections do not occur, so that an ultra-thin ceramic green sheet is formed. Even if it is wound afterwards, it is preferable because it does not cause defects such as pinholes in the ceramic green sheet.

As the particles contained in the surface layer B, it is more preferable to use silica particles and/or calcium carbonate particles from the viewpoint of transparency and cost. In addition to silica and/or calcium carbonate, inert inorganic particles and/or heat-resistant organic particles can be used, and other inorganic particles that can be used include alumina-silica composite oxide particles, hydroxyapatite particles, and the like. Further, examples of the heat-resistant organic particles include crosslinked polyacrylic particles, crosslinked polystyrene particles, benzoguanamine particles, and the like. Further, when using silica particles, porous colloidal silica is preferable, and when using calcium carbonate particles, hard calcium carbonate subjected to a surface treatment with a polyacrylic acid-based polymer compound is preferable from the viewpoint of preventing the lubricant from falling off.

The average particle diameter of the particles added to the surface layer B is preferably 0.1 µm or more and 2.0 µm or less, and particularly preferably 0.5 µm or more and 1.0 µm or less. When the average particle diameter of the particles is 0.1 µm or more, the sliding property of the mold release film is good, which is preferable. Moreover, when the average particle diameter is 2.0 micrometers or less, there is no possibility that pinholes by coarse particle|grains generate|occur|produce on the surface of a release layer, and is preferable. In addition, the method of measuring the average particle diameter of the particles can be carried out by observing the particles of the cross section of the film after processing with a scanning electron microscope, observing 100 particles, and setting the average particle diameter as the average value. As long as the object of the present invention is satisfied, the shape of the particles is not particularly limited, and spherical particles and non-amorphous spherical particles may be used. The particle diameter of an irregular particle can be calculated as a circle equivalent diameter. The circle equivalent diameter is a value obtained by dividing the area of the observed particle by the circumferential ratio (π), calculating the square root, and doubling it.

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

In the case where the surface layer B does not contain particles, it is also preferable to provide easy activity with a coat layer containing particles on the surface layer B. The means for providing this coating layer is not particularly limited, but it is preferably provided by a so-called in-line coating method applied during the film-forming of the polyester film. In addition, in the case of providing a coating layer that gives easy activity on the surface of the side where the release layer of the polyester film is not laminated, the polyester film does not need to have surface layers A and B, and substantially contains inorganic particles. It may consist of a single-layer polyester film which does not.

The region surface average roughness (Sa) of the surface layer B is preferably 40 nm or less, more preferably 35 nm or less, and still more preferably 30 nm or less. In addition, in the case where the surface layer B or the surface on the side where the release layer of the single-layer polyester film is not laminated with the coating layer (D) has reactivity, Sa of the surface is measured by measuring the surface on which the coating layer is laminated. And, it is preferable that it is in the range equal to the area|region surface average roughness (Sa) of said surface layer B.

(Coat layer D)

It is preferable that at least a binder resin and particles are contained in the coating layer D on the surface of the side where the release layer is not laminated with respect to the polyester film described above.

(Binder resin of coating layer D)

The binder resin constituting the release coating layer is not particularly limited, but specific examples of the polymer include polyester resin, acrylic resin, urethane resin, polyvinyl resin (polyvinyl alcohol, etc.), polyalkylene glycol, and polyalkyl. Renimine, methyl cellulose, hydroxy cellulose, starch, etc. are mentioned. Among these, it is preferable to use a polyester resin, an acrylic resin, and a urethane resin from the viewpoint of particle retention and adhesion. Moreover, when considering the affinity with a polyester film, a polyester resin is especially preferable. In order to achieve solubility in a solvent, dispersibility, and further adhesion with a base film or other layer, the polyester of the binder is preferably a copolymerized polyester. In addition, the polyester resin may be modified with polyurethane. Moreover, urethane resin is mentioned as another preferable binder resin which comprises the releasable coating layer on a polyester base film. Polycarbonate polyurethane resin is mentioned as a urethane resin. In addition, polyester resin and polyurethane resin may be used in combination, or other binder resins described above may be used in combination.

(Crosslinking agent of coat layer D)

In the present invention, in order to form a crosslinked structure in the releasable coating layer, the releasable coating layer may be formed by containing a crosslinking agent. By containing a crosslinking agent, it becomes possible to further improve the adhesiveness under high temperature and high humidity. Specific crosslinking agents include urea, epoxy, melamine, isocyanate, oxazoline, carbodiimide, aziridine, and the like. Moreover, in order to accelerate a crosslinking reaction, a catalyst etc. can be used suitably as needed.

(Particles in the coating layer D)

It is preferable that the lubricating coating layer contains lubricating agent particles in order to impart the sliding property to the surface. The particles may be inorganic particles or organic particles, and are not particularly limited, but (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, hydrohaloicite, calcium carbonate, magnesium carbonate, calcium phosphate, magnesium hydroxide, inorganic particles such as barium sulfate, Acrylic or methacrylic, vinyl chloride, vinyl acetate, nylon, styrene/acrylic, styrene/butadiene, polystyrene/acrylic, polystyrene/isoprene, polystyrene/isoprene, methyl methacrylate/butyl methacrylate Organic particles such as melamine-based, polycarbonate-based, urea-based, epoxy-based, urethane-based, phenol-based, diallyl phthalate-based, polyester-based, etc. are mentioned, but in order to impart adequate sliding properties to the coating layer, silica is used. It is particularly preferably used.

The average particle diameter of the particles is preferably 10 nm or more, more preferably 20 nm or more, and still more preferably 30 nm or more. If the average particle diameter of the particles is 10 nm or more, it is difficult to agglomerate, and the slip property can be secured, which is preferable.

The average particle diameter of the particles is preferably 1000 nm or less, more preferably 800 nm or less, and still more preferably 600 nm or less. When the average particle diameter of the particles is 1000 nm or less, transparency is maintained, and the particles do not fall off, which is preferable.

In addition, for example, mixing small particles having an average particle diameter of about 10 to 270 nm and large particles having an average particle diameter of about 300 to 1000 nm can also determine the area surface average roughness (Sa) and maximum protrusion height (Rp) described later. While keeping it small, it is preferable to reduce the average length (RSm) of the roughness curve element to achieve both slippage and smoothness, and particularly preferably, small particles of 30 nm or more and 250 nm or less, and a large average particle diameter of 350 to 600 nm. Particles are used together. In the case of mixing small particles and large particles, it is preferable to make the mass content of the small particles larger than the mass content of the large particles with respect to the entire solid content of the coating layer.

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

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

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

In addition, a coat layer may be provided on the surface of the surface layer A and/or the surface layer B before stretching or after uniaxial stretching in the film forming process on the surface of the surface layer A and/or surface layer B in order to improve the adhesion of the release layer to be applied later or to prevent charging. , Corona treatment, etc. can also be performed. In the case where a coat layer is also provided, Sa of each layer is substituted by the measured value of the surface of the coat layer. Moreover, when providing these coat layers on the surface of the surface layer A, it is preferable not to contain a particle.

(Release layer)

The release layer in the present invention is preferably formed by curing a coating film containing at least an energy ray-curable compound (I), a polyester resin (II), and a release component (III). Since the energy ray-curable compound (I) and the polyester resin (II) are phase-separated to form a sea island structure, it is possible to easily form irregularities of an appropriate height due to low protrusions, and coarse protrusions do not occur. There are no pinholes in the green sheet to be molded. In addition, since the flat portion is reduced by appropriate irregularities, the stress during the cut is easily removed during the half-cut test of the green sheet, and point peeling at the cut end (small peeling naturally occurring at the end portion) ), it is possible to suppress damage such as cracks and deformation at the end, and at the same time serve as a trigger for peeling in the next peeling step, which is the next step, so that peeling can be performed smoothly.

(Energy ray-curable compound (I))

As the energy ray-curable compound (I) used in the present invention, an energy ray-curable compound having three or more reactive groups in one molecule can be used. By having three or more reactive groups in one molecule, a release layer having a high elastic modulus is obtained, and deformation of the release layer during peeling of the green sheet can be suppressed, and heavy peeling can be suppressed, which is preferable. In addition, since the solvent resistance of the release layer can be improved, it is preferable to prevent erosion of the release layer by the solvent during slurry coating. Moreover, as an energy ray-curable compound having 3 or more reactive groups in one molecule, whether it reacts directly with energy rays or indirectly generated active species is not particularly limited. The content in the solid content in the coating liquid for forming a release layer of the energy ray-curable compound (I) is preferably 60 to 98% by mass, and preferably 75 to 97% by mass. By adding 60 mass% or more, the degree of crosslinking can be maintained and a high modulus of elasticity can be obtained.

Examples of the reactive group of the energy ray-curable compound (I) include a (meth)acryloyl group, an alkenyl group, an acrylamide group, a maleimide group, an epoxy group, and a cyclohexene oxide group. Among them, an energy ray-curable compound having a (meth)acryloyl group excellent in processability is preferable.

As the energy ray-curable compound having a (meth)acryloyl group, it can be used without being limited to monomers, oligomers, and polymers. Moreover, although it is preferable to contain a compound having 3 or more reactive groups in at least one molecule, two or more compounds such as a compound having 1 to 2 reactive groups in the molecule may be mixed and used. By mixing these compounds with a small number of reaction groups, curling and the like can be suppressed.

As energy ray-curable monomers having three or more (meth)acryloyl groups in the molecule, isocyanuric acid triacrylate, glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth) Acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth) ) Polyfunctional (meth)acrylates such as acrylate and dipentaerythritol hexa(meth)acrylate, and their ethylene oxide modified products, propylene oxide modified products, and caprolactone modified products.

As energy ray-curable monomers having 1 to 2 reactive groups in the molecule, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylic Rate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, cyclopentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, octyl (Meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, behenyl (meth)acrylate, isobornyl (meth) )Acrylate, cyclic trimethylolpropane formal (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxypropyl (meth)acrylate, (meth)acrylic acid, dicyclo Pentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, methoxypolyethylene glycol ( Meth)acrylate, pentamethylpiperidinyl (meth)acrylate, tetramethylpiperidinyl (meth)acrylate, 1,4-butanediol di(meth)acrylate, polyethylene glycol di(meth)acrylate, nonanediol Monomers such as di(meth)acrylate, bisphenol A di(meth)acrylate, neopentyl glycol di(meth)acrylate, cyclohexanediol di(meth)acrylate, and their ethylene oxide modified products, propylene oxide modified products And caprolactone modified products.

Examples of the energy ray-curable oligomers having three or more (meth)acryloyl groups in the molecule include urethane acrylate, polyester acrylate, polyether acrylate, epoxy acrylate, silicone-modified acrylate, and the like. Commercially available ones can be used. For example, the beam set (registered trademark) series manufactured by Arakawa Chemical Industry Co., Ltd., the NK oligo series manufactured by Shin-Nakamura Chemical Co., Ltd., the EBECRYL series manufactured by Daicel Allnex Co., Ltd., the Biscot series manufactured by Osaka Organic Chemical Industry Co., Ltd., and Kyoesha The urethane acrylate series manufactured by Kagaku Corporation, the Unidic series manufactured by DIC Corporation, etc. are mentioned.

Examples of energy ray-curable polymers having three or more (meth)acryloyl groups in the molecule include a graft polymer in which a (meth)acryloyl group is grafted on a polymer, and a block polymer in which a polyfunctional acrylic monomer is added to the polymer terminal. I can. As such polymers, acrylic resins, epoxy resins, polyester resins, polyorganosiloxanes, and the like can be used, and it is not particularly limited.

(Polyester resin (II))

As the polyester resin (II) used in the present invention, a polyester resin containing an ester structural unit derived from a 5-sodium sulfoisophthalic acid component can be used. The ester structural unit derived from this 5-sodium sulfoisophthalic acid component is 5-sodium sulfoisophthalic acid, ethylene glycol, diethylene glycol, propanediol, 1,4-butanediol, neopentyl glycol, 1,4-cyclo It is an ester structural unit composed of an arbitrary diol, glycol component typified by hexanedimethanol, 1,6-hexanediol, etc., and means that this ester structural unit is contained in a polyester resin. The aspect of containing the ester structural unit derived from the 5-sodium sulfoisophthalic acid component in the polyester resin may be in a mixed state with other ester structural units or polyester, may be in a copolymerized state with other ester structural units, and polyester resin It is a particularly preferable aspect that (II) is a copolymerized polyester containing an ester structural unit derived from a 5-sodium sulfoisophthalic acid component. When the polyester resin (II) contains an ester constituent unit derived from a 5-sodium sulfoisophthalic acid component, the compatibility with the energy ray-curable compound (I) is lowered, resulting in the formation of surface irregularities due to a sea-island structure suitable for the release layer. This is preferable because it becomes easy. The content of the ester structural unit derived from the 5-sodium sulfoisophthalic acid component in the polyester resin (II) is 0.5 mol when the total ester structural units constituting the polyester resin (II) are 100 mol%. It is preferably not less than% and not more than 12 mol%. If it is 0.5 mol% or more, compatibility with the energy ray-curable compound (I) decreases, and the formation of surface irregularities due to the sea-island structure suitable for the release layer becomes easy, and thus it is preferable. On the other hand, if it is 12 mol% or less, the SP value of the solvent in which the polyester resin (II) can be dissolved is not too high, the dissolution of the energy ray-curable compound (I) in the solvent is relatively easy, and the preparation of a coating solution It is preferable because it is easy. The content of the ester structural unit derived from the 5-sodium sulfoisophthalic acid component in the polyester resin (II) is more preferably 1 mol% or more and 10 mol% or less.

As the polyester resin (II), a single polyester resin may be sufficient, and two or more types of polyester resins may be used at the same time. In the case of using two or more types of polyester resins, other polyester resins are not particularly limited as long as at least one type of polyester resin contains an ester structural unit derived from a 5-sodium sulfoisophthalic acid component. The content of the polyester resin (II) in the solid content in the coating liquid for forming a release layer is preferably 1 to 40% by mass, and more preferably 1 to 10% by mass. By containing 1% by mass or more, sufficient surface irregularities can be formed, and when the content is 40% by mass or less, the degree of crosslinking by the energy ray-curable compound (I) of the release layer is increased, and the temperature dependence at the time of peeling is low, which is preferable.

As the polyester resin (II), a commercially available one can be used as long as it contains an ester structural unit derived from a 5-sodium sulfoisophthalic acid component. For example, the Toyobo company Viron (registered trademark) series, the Nippon Kose Chemical Co., Ltd. Nichigo polyester (registered trademark) series, etc. are mentioned.

(Release component (III))

The mold release component (III) used in the present invention is not particularly limited as long as it is a material capable of exhibiting releasability between a green sheet, such as a polyorganosiloxane, a fluorine compound, a long-chain alkyl compound, and a wax. Further, a material having a functional group capable of reacting and bonding with the energy ray-curable compound (I) having a (meth)acryloyl group or the like in these materials is preferable. In addition, two or more types of materials may be mixed and used. The content of the mold release component (III) in the solid content in the coating liquid for forming the mold release layer is preferably 0.05 to 10% by mass, and more preferably 0.1 to 5% by mass. If 0.05 mass% or more is added, the peeling force can be lightened, and if it is 10 mass% or less, migration of the mold release component to the ceramic green sheet or the like is suppressed, which is preferable.

Examples of the polyorganosiloxane include polydimethylsiloxane, polydiethylsiloxane, polyphenylsiloxane, etc., as well as siloxane-based compounds partially organically modified, block polymers having polyorganosiloxanes, and polymers grafted with polyorganosiloxanes. Etc. can also be used. As commercially available ones, for example, BYK (registered trademark) series manufactured by Big Chemie Co., Ltd., Modifer (registered trademark) series manufactured by Nichiyu Corporation, and the like can be used.

It does not specifically limit as a fluorine compound, A commercially available thing can be used. For example, the Megapak (registered trademark) series manufactured by DIC Corporation can be cited.

Examples of the long-chain alkyl compound include an acrylic polymer copolymerized with a long-chain alkyl acrylate, a graft polymer in which a long-chain alkyl is grafted, and a block polymer in which a long-chain alkyl is added to the terminal. Moreover, it does not specifically limit, A commercially available thing can be used. For example, Hitachi Kasei Co., Ltd. Tespine (registered trademark) series, Lion Speciality Chemicals Co., Ltd. Piroil (registered trademark), and the like can be mentioned.

Examples of active energy rays include electromagnetic waves such as infrared rays, visible rays, ultraviolet rays, and X-rays, electron rays, ion beams, particle rays such as neutron rays and α rays, and among them, ultraviolet rays having excellent manufacturing cost are used. It is desirable.

The atmosphere at the time of irradiation with the active energy ray may be in the general air or under a nitrogen gas atmosphere. In a nitrogen gas atmosphere, by reducing the oxygen concentration, the radical reaction proceeds smoothly and the elastic modulus of the release layer can be improved. However, if there is no practical problem even when irradiated in air, irradiation in air is preferable from an economical viewpoint.

(Photopolymerization initiator)

In the case of using a radical polymerization compound in the release layer of the present invention, it is preferable to add a photopolymerization initiator. As a photoinitiator, specifically, benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, benzoin Phosphorus dimethyl ketal, 2,4-diethylthioxanthone, 1-hydroxycyclohexyl phenyl ketone, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, benzyl, dibenzyl, di Acetyl, β-chloroanthraquinone, (2,4,6-trimethylbenzyldiphenyl)phosphine oxide, 2-benzothiazole-N,N-diethyl dithiocarbamate, and the like. In particular, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methylpropane-1-, which is considered to be excellent in surface curing properties One, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2 -Morpholinopropan-1-one is preferred, among them 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2 -Morpholinopropan-1-one is particularly preferred. These may be used individually or may be used in combination of 2 or more types.

The amount of the photoinitiator to be added is not particularly limited, but, for example, it is preferable to contain about 0.1 to 20% by mass as a solid content in the coating liquid for forming a release layer.

The release layer in the present invention may contain particles or the like having a particle diameter of 1 µm or less, but from the viewpoint of occurrence of pinholes, it is preferable not to contain particles or other protrusions.

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

In the present invention, the thickness of the release layer may be set according to the purpose of use, and is not particularly limited, but preferably, the range in which the release layer after curing becomes 0.2 to 3.5 µm is good, and more preferably 0.5 It is -3.0 μm. When the thickness of the release layer is 0.2 µm or more, the curability of the energy ray-curable copolymer polymer is good, and the elastic modulus of the release layer is improved, so that good peeling performance is obtained, which is preferable. In addition, when the thickness of the release film is less than 3.5 µm, curling is difficult to occur even when the thickness of the release film is reduced, and thus, it is preferable because it does not cause poor running performance in the process of forming and drying the ceramic green sheet.

It is preferable that the release film of this invention has an appropriate irregularity on the surface of a release layer. Therefore, it is preferable that the region surface average roughness (Sa) of the surface of the release layer is 5 to 40 nm. Further, it is more preferable that Sa is satisfied and the maximum protrusion height (Rp) on the surface of the release layer is 60 nm or less. The region surface average roughness Sa is preferably 5 to 20 nm, and at that time, it is more preferable that the maximum protrusion height Rp is 50 nm or less. The region surface average roughness Sa is particularly preferably 8.1 to 18 nm, and most preferably 8.5 to 17 nm. When the region surface average roughness Sa is 5 nm or more, when the ceramic green sheet is peeled, the zipping is reduced, and even the ultra-thin green sheet can be easily peeled without damage. Further, when the area surface average roughness Sa is 40 nm or less, it is sufficiently smaller than the particle diameter of the ceramic and does not affect the surface shape of the green sheet. If Sa is satisfied and the maximum protrusion height (Rp) on the surface of the release layer is 60 nm or less, the possibility of causing a pinhole defect is further reduced, and thus it is preferable. The maximum protrusion height Rp is preferably small, but since the region surface average roughness Sa is adjusted to 5 nm or more, the maximum protrusion height Rp may also be 5 nm or more, or 10 nm or more. In order to adjust to the range of the region surface average roughness (Sa) or the maximum protrusion height (Rp) of the release layer as described above, various factors are involved, but mainly, the surface layer A of the polyester film or the single-layer polyester film is Since it contains substantially no inorganic particles, the roughness of the surface on which the release layer is laminated is small, the release layer is an energy ray-curable compound (I) having 3 or more reactive groups in one molecule, and the energy ray-curable compound (I). It can be said that it can be said that the above-mentioned energy ray-curable compound (I) and the resin (II) which is incompatible with the island component and are cured are related. The method of adjusting the area surface average roughness (Sa) or the maximum protrusion height (Rp) of the release layer to the appropriate range as described above is not particularly limited, but mainly, the material of the energy ray-curable compound (I) and the resin (II) It can be preferably achieved by adjusting the combination or content ratio.

In the present invention, the method of forming the release layer is not particularly limited, and a coating solution obtained by dissolving or dispersing a releasable compound is spread on one side of the polyester film of the base material, and the solvent is removed by drying. After that, a method of curing is used.

When the release layer of the present invention is applied on a base film by solution coating, the drying temperature of the solvent drying is preferably 50°C or more and 120°C or less, and more preferably 60°C or more and 100°C or less. The drying time is preferably 30 seconds or less, and more preferably 20 seconds or less. Further, after drying the solvent, it is preferable to proceed with the curing reaction by irradiating an active energy ray. As the active energy rays used at this time, ultraviolet rays, electron rays, X-rays, and the like can be used, but ultraviolet rays are easy to use and are preferable. The amount of ultraviolet rays to be irradiated is preferably 30 to 300 mJ/cm 2, more preferably 30 to 200 mJ/cm 2 in terms of the amount of light. When it is set to 30 mJ/cm 2 or more, curing of the composition sufficiently proceeds, and when it is set to 300 mJ/cm 2 or less, the speed during processing can be improved, so that a release film can be produced economically, which is preferable.

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

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

Example

In order to explain the present invention in detail, examples are given below, but the present invention is not limited to these examples. The characteristic values used in the present invention were evaluated using the following method. In addition, hereinafter, the weight average molecular weight may be simply described as Mw.

(1) base film thickness

Using a millitron (electronic micro-indicator), 4 5 cm square samples were cut out from 4 arbitrary locations of the film to be measured, and each 5 points per sheet (20 points in total) was measured, and the average value was taken as the thickness. .

(2) release layer thickness

The thickness of the release layer was measured using an optical interference type film thickness meter (F20, manufactured by Philmetrics). (The refractive index of the release layer was calculated as 1.52).

(3) Area surface average roughness (Sa), maximum protrusion height (Rp)

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

(Measuring conditions)

Measurement mode: WAVE mode

·Objective lens: 50 times

0.5×Tube lens

(Interpretation conditions)

Face correction: 4th correction

Interpolation processing: full interpolation

(4) Phase separation structure

Using an electron microscope (VE-8800, manufactured by Keyence Corporation), the surface of the release layer was observed at a factor of 5000, and the presence or absence of phase separation was evaluated.

○: Phase separation is formed (the uneven structure due to phase separation can be confirmed)

×: No phase separation (uneven structure due to phase separation is not seen)

(5) Half-cut evaluation of ceramic green sheet

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

toluene 76.3 parts by mass

ethanol 76.3 parts by mass

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

Polyvinyl butyral 3.5 parts by mass (S-REC (registered trademark) BM-S manufactured by Sekisui Kagaku High School)

DOP (dioctyl phthalate) 1.8 parts by mass

Subsequently, it was applied to the mold release surface of the mold release film sample using an applicator so that the dried ceramic green sheet became 1.0 mu m, and dried at 90 DEG C for 2 minutes.

Using a rotary die cutter (RDC(FB)-A4, manufactured by Tsukatani Harmono Seisakusho), the obtained release film with ceramic green sheet was double-edged 50° from the side of the ceramic green sheet, 16 mm × 32 mm square, 3 μm in depth. I cut it in half as much as possible. With respect to the portion from which the green sheet was peeled, the distance from the end of the film to the peeled portion was measured with a laser microscope, and it was determined based on the following criteria. The measurement was carried out 5 times and the average value was adopted.

○: There is no defect such as a crack at the end, and there is sufficient peeling part (standard: the distance at which the peeling reaches is 4 mm or more from the end)

△: There is no defect such as a crack at the end, and there is a little peeling part (Standard: The distance at which the peeling reaches is 1mm or more from the end, less than 4mm)

×: There is a defect such as a crack at the end, or there is no peeling part (standard: the distance at which the peeling reaches is less than 1 mm from the end)

(Preparation of polyethylene terephthalate pellets (PET (1)))

As the esterification reaction apparatus, a continuous esterification reaction apparatus consisting of a three-stage complete mixing tank having a stirring apparatus, a condenser, a raw material input port, and a product discharge port was used. TPA (terephthalic acid) is 2 tons/hour, EG (ethylene glycol) is 2 moles per 1 mole of TPA, and antimony trioxide is made into an amount such that Sb atoms are 160 ppm with respect to PET, and the slurry is used as an esterification reaction device. It was continuously supplied to the 1st esterification reaction tube of, and was made to react at 255 degreeC with an average residence time of 4 hours at normal pressure. Subsequently, the reaction product in the first esterification reaction tube is continuously taken out of the system and supplied to the second esterification reaction tube, and distilled off from the first esterification reaction tube in the second esterification reaction tube. 8% by mass of EG to be produced is supplied to the produced PET, and in addition, an EG solution containing magnesium acetate tetrahydrate in an amount of 65 ppm of Mg atoms to the produced PET, and P for the produced PET. An EG solution containing TMPA (trimethyl phosphate) in an amount of 40 ppm of atoms was added, followed by reaction at 260°C with an average residence time of 1 hour at normal pressure. Subsequently, the reaction product from the second esterification reaction tube was continuously taken out of the system and supplied to the third esterification reaction tube, and averaged at a pressure of 39 MPa (400 kg/cm 2) using a high-pressure disperser (manufactured by Nippon Seiki). 0.4% by mass of synthetic calcium carbonate having an average particle diameter of 0.6 μm obtained by adhering 0.2% by mass of porous colloidal silica having an average particle diameter of 0.9 μm after dispersion treatment of 5 passes and 1% by mass of polyacrylic acid ammonium salt per calcium carbonate Each was reacted at 260°C for an average residence time of 0.5 hours at normal pressure while being added as a 10% EG slurry. The esterification reaction product generated in the third esterification reaction tube is continuously supplied to a three-stage continuous polycondensation reactor to perform polycondensation, and the 95% cut diameter of 20㎛ stainless steel fiber is filtered through a sintered filter. After performing ultrafiltration, it extruded in water, cut into chips after cooling, and obtained PET chips having an intrinsic viscosity of 0.60 dl/g (hereinafter, abbreviated as PET (1)). The lubricant content in the PET chip was 0.6% by mass.

(Preparation of polyethylene terephthalate pellets (PET(2)))

On the other hand, in the manufacture of the PET chip, a PET chip having an intrinsic viscosity of 0.62 dl/g containing no particles such as calcium carbonate or silica was obtained (hereinafter, abbreviated as PET (2)).

(Production of laminated film X1)

After drying these PET chips, they were melted at 285°C, melted at 290°C by a separate melt extruder, and a filter in which stainless steel fibers having a 95% cut diameter of 15 μm were sintered, and a 95% cut diameter of 15 μm. Two stages of filtration of a filter obtained by sintering stainless steel particles are performed, and they are joined in the feed block, and PET (1) is used as the surface layer B (anti-release surface side layer), and PET (2) is used as the surface layer A (release surface side layer). ), extruded (casting) into a sheet at a speed of 45 m/min, electrostatically adhered and cooled on a casting drum at 30°C by an electrostatic bonding method, and undrawn polyethylene having an intrinsic viscosity of 0.59 dl/g A terephthalate sheet was obtained. The layer ratio was adjusted to be PET(1)/(2)=60%/40% by calculation of the discharge amount of each extruder. Next, after heating this unstretched sheet with an infrared heater, it stretched 3.5 times in the longitudinal direction by the speed difference between rolls at a roll temperature of 80 degreeC. Thereafter, it was guided by a tenter, and stretching was performed 4.2 times in the transverse direction at 140°C. Subsequently, heat treatment was performed at 210°C in the heat setting zone. Thereafter, a relaxation treatment of 2.3% was performed at 170°C in the transverse direction to obtain a biaxially stretched polyethylene terephthalate film X1 having a thickness of 31 μm. Sa of the surface layer A of the obtained film X1 was 2 nm, and Sa of the surface layer B was 29 nm.

(Example 1)

On the surface layer A of the laminated film X1, the coating solution 1 of the following composition was applied using reverse gravure so that the thickness of the release layer after drying became 2.5 μm, dried at 90° C. for 30 seconds, and then 200 mJ/ by using a high-pressure mercury lamp. By irradiating ultraviolet rays so as to become cm 2, a release film for manufacturing an ultra-thin ceramic green sheet was obtained. With respect to the obtained release film, the release layer thickness, the region surface average roughness (Sa), the maximum protrusion height (Rp), the phase separation structure, and the peeling instrument at the time of half-cutting the ceramic green sheet were evaluated.

(Application liquid 1)

Compound (I) dipentaerythritol hexaacrylate 100.00 parts by mass (NK Ester (registered trademark) A-DPH, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., 6-functional acrylate, solid content 100%)

Resin (II) Polyester resin (A) 9.45 parts by mass

Release agent (Ⅲ) 1.26 parts by mass (Modified polydimethylsiloxane having an acryloyl group, BYK-UV3505, manufactured by Vicchemy Japan, solid content concentration 40% by mass)

Photopolymerization initiator 5.25 parts by mass (OMNIRAD (registered trademark) 907, manufactured by IGM Japan GK, solid content concentration 100% by mass)

Diluted solvent (MEK/toluene=1/1) 431.30 parts by mass

The polyester resin (A) used a polyester resin copolymerized with the following composition.

Monomer composition: (acid component) terephthalic acid/isophthalic acid/5-sodium sulfoisophthalic acid// (diol component) ethylene glycol/diethylene glycol=49/48.5/2.5//50/50 (mol%)

(Example 2)

Compared with Example 1, the polyester resin (B) was changed, and the following coating liquid 2 was used. Except for using the coating liquid 2, it carried out similarly to Example 1, and obtained the release film. With respect to the obtained release film, the release layer thickness, the region surface average roughness (Sa), the maximum protrusion height (Rp), the phase separation structure, and the peeling instrument at the time of half-cutting the ceramic green sheet were evaluated.

(Application liquid 2)

Compound (I) dipentaerythritol hexaacrylate 100.00 parts by mass (NK Ester (registered trademark) A-DPH, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., 6-functional acrylate, solid content 100%)

Resin (II) Polyester resin (B) 9.45 parts by mass

Release agent (Ⅲ) 1.26 parts by mass (Modified polydimethylsiloxane having an acryloyl group, BYK-UV3505 manufactured by Big Chemie Japan, solid content concentration 40% by mass)

Photopolymerization initiator 5.25 parts by mass (OMNIRAD (registered trademark) 907, manufactured by IGM Japan GK, solid content concentration 100% by mass)

Diluted solvent (MEK/toluene=1/1) 431.30 parts by mass

The polyester resin (B) used a polyester resin copolymerized with the following composition.

Monomer composition: (acid component) terephthalic acid/5-sodium sulfoisophthalic acid// (diol component) ethylene glycol/propanediol/trimethylolpropane=97.5/2.5//20/79.2/0.8 (mol%)

(Example 3)

Compared with Example 1, the polyester resin (II) and the diluting solvent were changed, and the following coating liquid 3 was used. A release film was obtained in the same manner as in Example 1 except that the coating solution 3 was used. With respect to the obtained release film, the release layer thickness, the region surface average roughness (Sa), the maximum protrusion height (Rp), the phase separation structure, and the peeling instrument at the time of half-cutting the ceramic green sheet were evaluated.

(Application solution 3)

Compound (I) dipentaerythritol hexaacrylate 100.00 parts by mass (NK Ester (registered trademark) A-DPH, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., 6-functional acrylate, solid content 100%)

Resin (II) Polyester resin (C) 9.45 parts by mass

Release agent (Ⅲ) 1.26 parts by mass (Modified polydimethylsiloxane having an acryloyl group, BYK-UV3505, manufactured by Vicchemy Japan, solid content concentration 40% by mass)

Photopolymerization initiator 5.25 parts by mass (OMNIRAD (registered trademark) 907, manufactured by IGM Japan GK, solid content concentration 100% by mass)

Diluent solvent (cyclopentanone) 431.30 parts by mass

The polyester resin (C) used a polyester resin copolymerized with the following composition.

Monomer composition: (acid component) terephthalic acid/isophthalic acid/5-sodium sulfoisophthalic acid// (diol component) ethylene glycol/diethylene glycol=48/48/4//80/20 (mol%)

(Example 4)

Compared with Example 1, the polyester resin (II) and the diluting solvent were changed, and the following coating liquid 4 was used. Except for using the coating liquid 4, it carried out similarly to Example 1, and obtained the release film. With respect to the obtained release film, the release layer thickness, the region surface average roughness (Sa), the maximum protrusion height (Rp), the phase separation structure, and the peeling instrument at the time of half-cutting the ceramic green sheet were evaluated.

(Application solution 4)

Compound (I) dipentaerythritol hexaacrylate 100.00 parts by mass (NK Ester (registered trademark) A-DPH, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., 6-functional acrylate, solid content 100%)

Resin (II) Polyester resin (D) 9.45 parts by mass

Release agent (Ⅲ) 1.26 parts by mass (Modified polydimethylsiloxane having an acryloyl group, BYK-UV3505, manufactured by Vicchemy Japan, solid content concentration 40% by mass)

Photopolymerization initiator 5.25 parts by mass (OMNIRAD (registered trademark) 907, manufactured by IGM Japan GK, solid content concentration 100% by mass)

Diluent solvent (cyclopentanone) 431.30 parts by mass

The polyester resin (D) used a polyester resin copolymerized with the following composition.

Monomer composition: (acid component) isophthalic acid/5-sodium sulfoisophthalic acid// (diol component) diethylene glycol = 93/7//100 (mol%)

(Comparative Example 1)

Compared with Example 1, polyester resin (II) was changed, and the following coating liquid 5 was used. Except for using the coating liquid 5, it carried out similarly to Example 1, and obtained the release film. With respect to the obtained release film, the release layer thickness, the region surface average roughness (Sa), the maximum protrusion height (Rp), the phase separation structure, and the peeling instrument at the time of half-cutting the ceramic green sheet were evaluated.

(Application solution 5)

Compound (I) dipentaerythritol hexaacrylate 100.00 parts by mass (NK Ester (registered trademark) A-DPH, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., 6-functional acrylate, solid content 100%)

Resin (II) Polyester resin (E) 9.45 parts by mass

Release agent (Ⅲ) 1.26 parts by mass (Modified polydimethylsiloxane having an acryloyl group, BYK-UV3505, manufactured by Vicchemy Japan, solid content concentration 40% by mass)

Photopolymerization initiator 5.25 parts by mass (OMNIRAD (registered trademark) 907, manufactured by IGM Japan GK, solid content concentration 100% by mass)

Diluted solvent (MEK/toluene=1/1) 431.30 parts by mass

The polyester resin (E) used a polyester resin copolymerized with the following composition.

Monomer composition: (acid component) terephthalic acid/isophthalic acid// (diol component) ethylene glycol/neopentyl glycol=50/50//50/50 (mol%)

(Comparative Example 2)

Compared with Example 1, polyester resin (II) was changed, and the following coating liquid 5 was used. Except for using the coating liquid 5, it carried out similarly to Example 1, and obtained the release film. With respect to the obtained release film, the release layer thickness, the region surface average roughness (Sa), the maximum protrusion height (Rp), the phase separation structure, and the peeling instrument at the time of half-cutting the ceramic green sheet were evaluated.

(Application solution 5)

Compound (I) dipentaerythritol hexaacrylate 100.00 parts by mass (NK Ester (registered trademark) A-DPH, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., 6-functional acrylate, solid content 100%)

Resin (II) Polyester resin (F) 9.45 parts by mass

Release agent (Ⅲ) 1.26 parts by mass (Modified polydimethylsiloxane having an acryloyl group, BYK-UV3505, manufactured by Vicchemy Japan, solid content concentration 40% by mass)

Photopolymerization initiator 5.25 parts by mass (OMNIRAD (registered trademark) 907, manufactured by IGM Japan GK, solid content concentration 100% by mass)

Diluted solvent (MEK/toluene=1/1) 431.30 parts by mass

The polyester resin (F) used a polyester resin copolymerized with the following composition.

Monomer composition: (acid component) terephthalic acid/isophthalic acid/sebacic acid// (diol component) ethylene glycol/neopentyl glycol=52/18/30//54/46 (mol%)

(Comparative Example 3)

Compared with Example 1, the polyester resin (II) was changed, and the following coating liquid 6 was used. Except for using the coating liquid 6, it carried out similarly to Example 1, and obtained the release film. With respect to the obtained release film, the release layer thickness, the region surface average roughness (Sa), the maximum protrusion height (Rp), the phase separation structure, and the peeling instrument at the time of half-cutting the ceramic green sheet were evaluated.

(Application liquid 6)

Compound (I) dipentaerythritol hexaacrylate 100.00 parts by mass (NK Ester (registered trademark) A-DPH, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., 6-functional acrylate, solid content 100%)

Resin (II) Polyester resin (G) 9.45 parts by mass

Release agent (Ⅲ) 1.26 parts by mass (Modified polydimethylsiloxane having an acryloyl group, BYK-UV3505, manufactured by Vicchemy Japan, solid content concentration 40% by mass)

Photopolymerization initiator 5.25 parts by mass (OMNIRAD (registered trademark) 907, manufactured by IGM Japan GK, solid content concentration 100% by mass)

Diluted solvent (MEK/toluene=1/1) 431.30 parts by mass

As the polyester resin (G), a polyester resin copolymerized with the following composition was used.

Monomer composition: (acid component) terephthalic acid/isophthalic acid/adipic acid/trimelitic acid// (diol component) 2-methyl-1,3-propanediol/butanediol=40/39/20/1//60/40 ( mol%)

(Comparative Example 4)

Compared with Example 1, polyester resin (II) was changed, and the following coating liquid 7 was used. A release film was obtained in the same manner as in Example 1 except that the coating solution 7 was used. With respect to the obtained release film, the release layer thickness, the region surface average roughness (Sa), the maximum protrusion height (Rp), the phase separation structure, and the peeling instrument at the time of half-cutting the ceramic green sheet were evaluated.

(Application liquid 7)

Compound (I) dipentaerythritol hexaacrylate 100.00 parts by mass (NK Ester (registered trademark) A-DPH, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., 6-functional acrylate, solid content 100%)

Resin (II) Polyester resin (H) 9.45 parts by mass

Release agent (Ⅲ) 1.26 parts by mass (Modified polydimethylsiloxane having an acryloyl group, BYK-UV3505, solid content concentration 40% by mass)

Photopolymerization initiator 5.25 parts by mass (OMNIRAD (registered trademark) 907, manufactured by IGM Japan GK, solid content concentration 100% by mass)

Diluted solvent (MEK/toluene=1/1) 431.30 parts by mass

As the polyester resin (F), a polyester resin copolymerized with the following composition was used.

Monomer composition: (acid component) terephthalic acid/isophthalic acid/azelaic acid// (diol component) ethylene glycol/neopentyl glycol=30/20/50//65/35 (mol%)

1 and 2 show electron micrographs of the surface of the release layer of Examples 1 and 2 used for evaluation of the unevenness of the surface of the release layer by the phase-separated structure.

[Table 1]

Industrial applicability

According to the release film for producing a ceramic green sheet of the present invention, compared with the release film for producing a conventional ceramic green sheet, the peeling force is not too heavy, the processability is excellent, and the release layer has no protrusions, so the thickness to be formed It has become possible to provide a release film for manufacturing a ceramic green sheet capable of reducing defects such as pinholes in an ultra-thin ceramic green sheet of 1 μm or less.

Claims (8)

A release film in which a release layer is laminated directly on at least one side of a polyester film or via another layer, wherein the release layer includes an energy ray-curable compound (I), a polyester resin (II), and a release component ( A release film for producing a ceramic green sheet, obtained by curing a coating film containing at least III), and wherein the polyester resin (II) contains an ester structural unit derived from a 5-sodium sulfoisophthalic acid component. The method of claim 1,
The release layer has a phase-separated structure in which an energy ray-curable compound (I) is used as an ocean component and a polyester resin (II) is used as an island component, and a release film for producing a ceramic green sheet having surface irregularities. The method according to claim 1 or 2,
A release film for producing a ceramic green sheet in which the release layer substantially does not contain inorganic particles. The method according to any one of claims 1 to 3,
The energy ray-curable compound (I) is a (meth)acrylic acid ester having three or more acryloyl groups in one molecule, a release film for producing a ceramic green sheet. The method according to any one of claims 1 to 4,
A release film for producing a ceramic green sheet having a release layer having a thickness of 0.2 to 3.5 µm. The method according to any one of claims 1 to 5,
A release film for producing a ceramic green sheet in which the region surface average roughness (Sa) of the release layer is 5 to 40 nm. The method according to any one of claims 1 to 6,
A release film for manufacturing a ceramic green sheet having a maximum protrusion height (Rp) of 60 nm or less on the surface of the release layer. A method of manufacturing a ceramic green sheet for forming a ceramic green sheet using the release film for manufacturing a ceramic green sheet according to any one of claims 1 to 7, wherein the formed ceramic green sheet has a thickness of 0.2 µm to 1.0 µm. Method of manufacturing phosphorus ceramic green sheet.

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