KR102518776B1 - Release Film for Ceramic Green Sheet Manufacturing - Google Patents

Abstract

[Problem] To provide a release film for forming a ceramic green sheet that has excellent peelability and hardly causes damage such as pinhole defects or cracks during peeling to an ultrathin ceramic green sheet to be molded.
[Solution Means] A release film in which a release layer of 0.2 to 3.5 μm is laminated on at least one side of a polyester film directly or through another layer, the area surface roughness (Sa) of the surface of the release layer is 5 to 40 nm, and the maximum peak height (Rp) a release film for producing a ceramic green sheet of 60 nm or less.

Description

Release Film for Ceramic Green Sheet Manufacturing

The present invention relates to a release film for manufacturing an ultra-thin ceramic green sheet, and more particularly, to a release film capable of suppressing the occurrence of process defects due to pinholes, non-uniformity in thickness, or defective peeling during the manufacture of an ultra-thin ceramic green sheet. , It relates to a release film for manufacturing an ultra-thin ceramic green sheet.

Conventionally, a release film in which a release layer is laminated on a polyester film as a base material is used for molding ceramic green sheets such as multilayer ceramic capacitors (hereinafter referred to as MLCC) and ceramic substrates. In recent years, along with miniaturization and increase in capacity of multilayer ceramic capacitors, the thickness of ceramic green sheets also tends to be reduced. The ceramic green sheet is molded by applying a slurry containing a ceramic component such as barium titanate and a binder resin to a release film and drying it. A multilayer ceramic capacitor is manufactured by printing electrodes on the molded ceramic green sheets, peeling them off from the release film, laminating the ceramic green sheets, pressing and cutting them, firing them, and coating them with external electrodes. Until now, when a ceramic green sheet is molded on the surface of a release layer of a polyester film, fine protrusions on the surface of the release layer affect the molded ceramic green sheet, and defects such as cratering and pinholes tend to occur. had a problem. Therefore, various methods have been developed for realizing a release layer surface having excellent flatness (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. Therefore, higher smoothness has come to be requested|required of the surface of a release layer. In addition, since the strength of the ceramic green sheet decreases as the ceramic green sheet thins, it is preferable not only to smooth the surface of the release layer, but also to make the peeling force at the time of peeling the ceramic green sheet from the release film low and uniform. It has been desirable to minimize the load applied to the ceramic green sheet when peeling the ceramic green sheet from the release film so as not to damage the ceramic green sheet.

As a method on the side of the release layer for smoothing the surface of the release layer and suppressing the load on the ceramic green sheet during peeling, an active energy ray curing component is used in the release layer of the release film to increase the crosslinking density of the release layer and improve the elastic modulus. , Measures to reduce the peeling force by suppressing the elastic deformation of the release layer during peeling of the ceramic green sheet have been studied (for example, Patent Literatures 2 and 3). However, in this method, since the smoothness was too high, surface peeling occurred, the peeling force became heavy, and cracks occurred in the green sheet in some cases. In addition, when the ultra-thin ceramic green sheet is processed, when the smooth surface comes in contact with a smooth roll or rubber roll for controlling the tension of the coating equipment, the slipperiness between the roll and the smooth surface is insufficient and the tension control becomes unstable, and the green sheet coated surface becomes unstable. There was a problem of deterioration in smoothness.

Then, a release film excellent in the balance of smoothness and uniform peelability has been reported by setting it as a polyester film having appropriate large projections serving as a trigger (peeling start point) at the time of peeling start (for example, Patent Literature 4). However, in the case of a filler incorporated into PET, coarse protrusions due to filler aggregation could not be completely eliminated, resulting in a defect in the product. In particular, in the ultra-thin ceramic green sheet, since the inorganic filler used as the ceramic material has a particle size of about 60 nm to 800 nm (Patent Documents 5 and 6), when the film described in Patent Document 4 is used, local holes are formed on the peeling surface. There was a problem with this occurring.

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

Then, as a result of earnest examination, the inventors of the present invention confirmed that the above-mentioned heavy peeling, reduction in processability and generation of fault factors could be suppressed at the same time by forming low protrusions having a constant shape continuously on the surface of the release layer. Another object of the present invention is to provide a release film for forming a ceramic green sheet that has excellent peelability and hardly causes damage such as pinhole defects or cracks during peeling to an ultrathin ceramic green sheet to be formed.

That is, the present invention includes the following configurations.

1. A release film in which a release layer of 0.2 to 3.5 μm is laminated on at least one side of a polyester film directly or through another layer, and the area surface roughness (Sa) of the surface of the release layer is 5 to 40 nm, the maximum peak height (Rp ) is a release film for producing ceramic green sheets with a thickness of 60 nm or less.

2. The release layer contains an energy ray-curable compound (I) having three or more reactive groups in one molecule, and the energy ray-curable compound (I) as a sea component, an island component that is incompatible with the energy ray-curable compound (I) The release film for producing a ceramic green sheet according to the first item, obtained by curing a coating film containing at least the resin (II) and the release component (III).

3. The release film for producing a ceramic green sheet according to the above 1st or 2nd, wherein the release layer does not substantially contain inorganic particles.

4. The polyester film is a laminated polyester film comprising two or more layers including at least a surface layer A and a surface layer B on the opposite side to the surface layer A, a release layer is laminated on the surface layer A, and the surface layer A has The release film for producing a ceramic green sheet according to any one of 1st to 3rd above, which is substantially free of inorganic particles.

5. The release mold for producing a ceramic green sheet according to 4 above, wherein the surface layer B contains particles, the particles are silica particles and/or calcium carbonate particles, and the total content of the particles is 5000 to 15000 ppm with respect to the total mass of the surface layer B. film.

6. The ceramic according to any one of 1 to 3 above, wherein the polyester film does not substantially contain inorganic particles and a coating layer containing particles is laminated on the side of the polyester film on which the release layer is not laminated. Release film for manufacturing green sheets.

7. A method for manufacturing a ceramic green sheet in which a ceramic green sheet is molded using the release film for manufacturing a ceramic green sheet according to any one of 1 to 6 above, wherein the molded ceramic green sheet has a thickness of 0.2 µm to 1.0 µm Method for producing a ceramic green sheet, characterized in that.

According to the release film for manufacturing a ceramic green sheet of the present invention, compared to the conventional release film for manufacturing a ceramic green sheet, the peeling force is not excessively heavy, the processability is excellent, and the release layer has no large protrusions, so the molded thickness is 1 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 having a thickness of less than ㎛.

Hereinafter, the present invention will be described in detail.

The release film for manufacturing an ultra-thin ceramic green sheet of the present invention has a release layer on at least one side of a polyester film directly or through another layer, and the area surface roughness (Sa) of the surface of the release layer is 5 to 40 nm, and the maximum peak height is (Rp) is preferably 60 nm or less. Then, the release layer comprises an energy ray-curable compound (I) having three or more reactive groups in one molecule, and a resin (II) that is incompatible with the energy ray-curable compound (I) and forms a sea-island structure by phase separation; A release film for producing a ceramic green sheet obtained by curing a coating film containing at least component (III) is a preferred embodiment.

(polyester film)

The polyester constituting the polyester film used as a base material in the release film of the present invention is not particularly limited, and a film formed of a polyester commonly used as a release film base material can be used, but is preferably aromatic. It is preferably a crystalline linear saturated polyester containing a dibasic acid component and a diol component, such as polyethylene terephthalate, polyethylene-2,6-naphthalate, polybutylene terephthalate, polytrimethylene terephthalate or these resins. Copolymers containing constituents as main components are more suitable, and in particular, polyester films formed from polyethylene terephthalate are suitable. In polyethylene terephthalate, the repeating unit of ethylene terephthalate is preferably 90 mol% or more, more preferably 95 mol% or more, and other dicarboxylic acid components and diol components may be copolymerized in small amounts, but from the point of cost , preferably made only of terephthalic acid and ethylene glycol. In addition, known additives such as antioxidants, light stabilizers, ultraviolet absorbers, and crystallizers may be added within a range that does not impair the effect of the film of the present invention. It is preferable that a polyester film is a polyester film for reasons, such as a high elastic modulus in both directions, as for a polyester film.

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, breakage is less likely to occur in the stretching step, which is preferable. Conversely, when it is 0.70 dl/g or less, the cutting property at the time of cutting to a predetermined product width is good and dimensional defects do not occur, so it is preferable. In addition, it is preferable to vacuum-dry the raw material sufficiently.

The manufacturing method of the polyester film in this invention is not specifically limited, Conventionally, the method generally used can be used. For example, it can be obtained by melting the polyester in an extruder, extruding it into a film form, cooling it in a rotating cooling drum to obtain an unstretched film, and uniaxially or biaxially stretching the unstretched film. The biaxially stretched film can be obtained by sequentially biaxially stretching a longitudinally or transversely uniaxially oriented film in the transverse or longitudinal direction, or by simultaneously biaxially stretching an unstretched film in the longitudinal and transverse directions. there is.

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 polyester. It is preferable to stretch 1 to 8 times, particularly 2 to 6 times in each of the vertical and horizontal directions.

The polyester film preferably has a thickness of 12 to 50 μm, more preferably 12 to 38 μm, more preferably 15 μm to 31 μm. When the thickness of the film is 12 μm or more, there is no risk of deformation due to heat during production of the film, processing of the release layer, or molding of the ceramic green sheet, which is preferable. On the other hand, when the thickness of the film is 50 μm or less, the amount of the film discarded after use does not increase extremely, which is preferable in order to reduce the environmental load, and furthermore, since the material per area of the release film to be used is reduced, it is also from an economic point of view. desirable.

The polyester film substrate 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 thereof. In the case of a laminated polyester film comprising 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 side of the surface layer A that does not substantially contain inorganic particles. As for the laminate configuration, if the layer on the side where the release layer is applied is called surface layer A, the layer on the opposite side is called surface layer B, and the core layer other than these is called core layer C, the layer configuration in the thickness direction is release layer/surface layer A/surface layer. B, or a laminated structure such as release layer/surface layer A/core layer C/surface layer B is exemplified. Naturally, the core layer C may have a plurality of layer configurations. Also, the surface layer B may not contain particles. In that case, it is preferable to provide a coating layer (D) containing particles and a binder on the surface layer B in order to impart sliding properties for winding the film into a roll shape.

In the polyester film base material in the present invention, it is preferable that the surface layer A forming the surface on which the release layer is applied does not substantially contain inorganic particles. At this time, the area surface average roughness (Sa) of the surface layer A is preferably 7 nm or less. When Sa is 7 nm or less, 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, occurrence of pinholes or the like is difficult to occur during formation of the laminated ultra-thin layer ceramic green sheet, which is preferable. It can be said that the area surface average roughness (Sa) of the surface layer A is preferably as small as possible, but it does not matter as long as it is 0.1 nm or more. However, when an anchor coating layer or the like described below is provided on the surface layer A, it is preferable that the coating layer does not substantially contain inorganic particles, and the average surface roughness (Sa) of the region after lamination of the coating layer is preferably within the above range. In the present invention, "substantially not containing inorganic particles" is defined as being 50 ppm or less when inorganic elements are quantified by fluorescence X-ray analysis, preferably 10 ppm or less, and most preferably below the detection limit. is the content This is because even if inorganic particles are not actively added to the film, foreign matter-derived contaminants and raw material resins or contaminants adhering to lines and equipment in the production process of the film may be peeled off and mixed in the film. .

In the case where the polyester film substrate in the present invention is a laminated film, the surface layer A to which the release layer is applied and the surface layer B forming the opposite surface contain particles from the viewpoint of the slipperiness of the film and the ease of removing air. It is preferable, and it is especially preferable to contain silica particles and/or calcium carbonate particles. The particle content to be contained is preferably 5000 to 15000 ppm in total of the particles in the surface layer B. At this time, it is preferable that the region surface average roughness (Sa) of the film of the surface layer B is in the range of 1 to 40 nm. More preferably, it is the range of 5-35 nm. When the total amount of silica particles and/or calcium carbonate particles in the surface layer B is 5000 ppm or more and Sa is 1 nm or more, when the film is rolled up into a roll, air can be uniformly released, the winding appearance is good, and the flatness is good. , which is suitable for the production of ultra-thin ceramic green sheets. Further, when the total amount of silica particles and/or calcium carbonate particles is 15000 ppm or less and Sa is 40 nm or less, aggregation of the lubricant is unlikely to occur and coarse protrusions are not formed. It is preferable because defects such as pinholes do not occur in the Edo 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. Examples of other inorganic particles that can be used include alumina-silica composite oxide particles, hydroxyapatite particles, and the like. Moreover, as heat-resistant organic particle|grains, crosslinked polyacrylic particle|grains, crosslinked polystyrene particle|grains, benzoguanamine type particle|grains, etc. are mentioned. In the case of using silica particles, porous colloidal silica is preferable, and in the case of using calcium carbonate particles, light calcium carbonate surface-treated with a polyacrylic acid-based polymer compound is preferable from the viewpoint of preventing the lubricant from falling off. do.

The average particle diameter of the 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 release film has good slipperiness and is preferable. Moreover, when the average particle size is 2.0 μm or less, there is no possibility of occurrence of pinholes due to coarse particles on the surface of the release layer, which is preferable. In addition, the method of measuring the average particle diameter of the particles can be performed by observing the particles of the cross-section of the film after processing with a scanning electron microscope, observing 100 particles, and using the average value as the average particle diameter. The shape of the particles is not particularly limited as long as the object of the present invention is satisfied, and spherical particles and irregularly shaped non-spherical particles can be used. Irregular particle The particle diameter can be calculated as an equivalent circle diameter. The equivalent circle diameter is a value obtained by dividing the area of the observed particle by the circumference ratio (π), calculating the square root, and doubling the result.

The surface layer B may contain two or more types of particles of different materials. Moreover, you may contain what is the same kind of particle|grain and has a different average particle diameter.

In the case where the surface layer B does not contain particles, it is also preferable to impart lubricity to a coating layer containing particles on the surface layer B. The means for providing this coating layer is not particularly limited, but it is preferable to provide by a so-called in-line coating method in which coating is applied within the film formation of a polyester film. In the case where a coating layer having release properties is provided on the surface of the polyester film on which the release layer is not laminated, the polyester film does not need to have the surface layers A and B and does not substantially contain inorganic particles. A single-layer polyester film may be included.

The area surface average roughness (Sa) of the surface layer B is preferably 40 nm or less, more preferably 35 nm or less, still more preferably 30 nm or less. In addition, in the case where the surface layer B or the surface of the single layer polyester film on which the release layer is not laminated has the coating layer (D) to give the release activity, the surface Sa of the surface is measured as the surface on which the coating layer is laminated, It is preferably within the same range as the area surface average roughness (Sa) of the surface layer B.

(coating layer D)

It is preferable that at least a binder resin and particles are contained in the surface coating layer D on the side of the polyester film on which no release layer is laminated.

(Binder Resin of Coating Layer D)

The binder resin constituting the lubricating coating layer is not particularly limited, but specific examples of the polymer include polyester resins, acrylic resins, urethane resins, polyvinyl resins (such as polyvinyl alcohol), polyalkylene glycols, polyalkylene imines, Methyl cellulose, hydroxy cellulose, starch, etc. are mentioned. Among these, it is preferable to use a polyester resin, an acrylic resin, or a urethane resin from the viewpoint of retention of particles and adhesion. In addition, when considering affinity with a polyester film, a polyester resin is especially preferable. In order to achieve solubility in solvents, dispersibility, and also adhesiveness with base films and other layers, it is preferable that the polyester of the binder is co-polyester. In addition, the polyester resin may be polyurethane-modified. In addition, as another preferable binder resin constituting the lubricity coating layer on the polyester base film, a urethane resin is exemplified. Polycarbonate polyurethane resin is mentioned as a urethane resin. In addition, a polyester resin and a polyurethane resin may be used together, and the said other binder resin may be used together.

(Crosslinking agent of coating layer D)

In the present invention, in order to form a cross-linked structure in the easy-slide coating layer, the easy-slide coating layer may be formed by containing a cross-linking agent. By containing a crosslinking agent, it becomes possible to further improve the adhesiveness under high temperature, high humidity. Specific crosslinking agents include urea, epoxy, melamine, isocyanate, oxazoline, carbodiimide, aziridine and the like. In addition, in order to accelerate the crosslinking reaction, a catalyst or the like can be appropriately used as needed.

(Particles in coating layer D)

The lubrication 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, carbonic acid Inorganic particles such as zinc, zirconium oxide, titanium dioxide, satin white, aluminum silicate, diatomaceous earth, calcium silicate, aluminum hydroxide, hydrous halloysite, calcium carbonate, magnesium carbonate, calcium phosphate, magnesium hydroxide, barium sulfate, (2) acrylic or Methacrylic, vinyl chloride, vinyl acetate, nylon, styrene/acrylic, styrene/butadiene, polystyrene/acrylic, polystyrene/isoprene, polystyrene/isoprene, methyl methacrylate/butyl methacrylate, melamine, Polycarbonate-based, urea-based, epoxy-based, urethane-based, phenol-based, diallylphthalate-based, and polyester-based organic particles are exemplified, but in order to impart appropriate slipperiness to the coating layer, silica is particularly preferred. used

The average particle diameter of the particles is preferably 10 nm or more, more preferably 20 nm or more, still more preferably 30 nm or more. When the average particle diameter of the particles is 10 nm or more, it is difficult to aggregate and slipperiness can be ensured, which is preferable.

The average particle diameter of the particles is preferably 1000 nm or less, more preferably 800 nm or less, 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 with an average particle diameter of about 10 to 270 nm and large particles with an average particle diameter of about 300 to 1000 nm also reduces the area surface average roughness (Sa) and maximum protrusion height (RP) described later. It is preferable to reduce the average length (RSm) of the roughness curve element while maintaining it, and to achieve both slipperiness and smoothness, and particularly preferably, small particles of 30 nm or more and 250 nm or less and large particles with an average particle diameter of 350 to 600 nm are used together. is to do When small particles and large particles are mixed, it is preferable to set the mass content of small particles larger than that of large particles with respect to the total solid content of the coating layer.

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

It is preferable that the thickness ratio of the surface layer A which is the layer on the side which provides the said release layer is 20 % or more and 50 % or less of the thickness of the whole layer of a base film. When it is 20% or more, it is difficult to receive the influence of particles included in the surface layer B or the like from inside the film, and it is easy for the area surface average roughness Sa to satisfy the above range, which is preferable. When 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.

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

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

(release layer)

The release layer of the present invention comprises an energy ray-curable compound (I) having three or more reactive groups in one molecule, a resin (II) that is incompatible with the energy ray-curable compound (I) and forms a sea-island structure by phase separation, and a release component ( It is preferably formed by curing a coating film containing at least III). By phase-separating the energy ray-curable compound (I) and the resin (II) to form a sea-island structure, it is possible to easily form irregularities of an appropriate height, and no pinholes or the like occur in the green sheet because coarse protrusions do not occur. don't In addition, since flat portions are almost eliminated and peeling occurs at points, even an ultra-thin ceramic green sheet made of a soft material can be peeled off without zipping, so damage such as cracks and deformation can be suppressed.

(Energy ray curable compound (I) having three or more reactive groups in one molecule)

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, it becomes a mold release layer with a high modulus of elasticity, suppresses deformation of the mold release layer at the time of peeling the green sheet, and suppresses heavy peeling. In addition, since the solvent resistance of the release layer can be improved, erosion of the release layer by the solvent at the time of slurry coating can be prevented, so it is preferable. In addition, as an energy ray-curable compound having three or more reactive groups in one molecule, whether it reacts directly with an energy ray or indirectly generated active species is not particularly limited. The content of the energy ray-curable compound (I) in the solid content in the coating liquid for forming a release layer is preferably 60 to 98% by mass, and preferably 75 to 97% by mass. By adding 60% by 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 having excellent processability is preferable.

As an energy ray-curable compound having a (meth)acryloyl group, it can be used without limitation to monomers, oligomers, and polymers. In addition, it is preferable to contain a compound having three or more reactive groups in at least one molecule, but a mixture of two or more compounds, such as a compound having 1 to 2 reactive groups in a molecule, may be used. By mixing a compound with a small number of these reactive groups, curl or the like can be suppressed.

Examples of the energy beam curable monomer having three or more (meth)acryloyl groups in the molecule include isocyanuric acid triacrylate, glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate. ) Acrylates, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaeryth polyfunctional (meth)acrylates such as ritolpenta(meth)acrylate and dipentaerythritol hexa(meth)acrylate, and ethylene oxide-modified products, propylene oxide-modified products, and caprolactone-modified products thereof; and the like. .

Examples of the energy ray curable monomer having 1 to 2 reactive groups in the molecule include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, and butyl (meth)acrylate. , 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, dicyclophen Tenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, methoxy polyethylene glycol (meth)acrylate ) Acrylate, pentamethylpiperidinyl (meth)acrylate, tetramethylpiperidinyl (meth)acrylate, 1,4-butanedioldi(meth)acrylate, polyethylene glycoldi(meth)acrylate, nonanedioldi Monomers such as (meth)acrylate, bisphenol A di(meth)acrylate, neopentyl glycol di(meth)acrylate, and cyclohexanediol di(meth)acrylate, and their ethylene oxide-modified products and propylene oxide-modified products Water, caprolactone modified product, etc. are mentioned.

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, which are generally commercially available. You can use what is being done. For example, Beam Set (registered trademark) series manufactured by Arakawa Chemical Industry Co., Ltd., NK Oligo series manufactured by Shin Nakamura Chemical Industry Co., Ltd., EBECRYL series manufactured by Daicel Allnex Corporation, Biscott series manufactured by Osaka Yuki Chemical Industry Co., Ltd., Kyoeisha The urethane acrylate series by Kagaku, the Unidic series by DIC, etc. are mentioned.

Examples of energy ray-curable polymers having three or more (meth)acryloyl groups in the molecule include graft polymers in which (meth)acryloyl groups are grafted onto polymers, block polymers in which polyfunctional acrylic monomers are added to polymer terminals, and the like. there is. As the above polymers, acrylic resins, epoxy resins, polyester resins, polyorganosiloxanes and the like can be used, and are not particularly limited.

(Resin (II))

As the resin (II) used in the present invention, it is dissolved or dispersed in the same solvent as the energy ray-curable compound (I), and both are dissolved or dispersed in the state of the coating agent, but after application, the solvent is dried and cured to form a resin. Among the release layers, it is incompatible with each other, and it is preferable to form a sea-island structure using energy ray curable compound (I) as a sea component and resin (II) as an island component, and as resin (II), if the above requirements are satisfied, It can be used without limitation. Two or more resins may be used simultaneously. As content in the solid content of resin (II) in the coating liquid for mold release layer formation, 1-40 mass % is preferable, and 1-10 mass % is preferable. Sufficient unevenness can be formed by containing 1 mass % or more, and when it is 40 mass % or less, the crosslinking degree of a release layer is high and temperature dependence at the time of peeling is low, and it is preferable.

As the resin (II), for example, a polyester resin, an acrylic resin, a urethane resin, a polyester urethane resin, a polyimide resin, a polyamideimide resin, a cellulose resin, etc., can be used without particular limitation as long as they are solvent-soluble. , it becomes a condition that it is resin incompatible with energy ray-curable compound (I).

It does not specifically limit as a polyester resin, A commercially available thing can be used. For example, the Byron (registered trademark) series by Toyobo Co., Ltd., the Nichigo Polyester (registered trademark) series by Nippon Kose Chemical Industry Co., Ltd., etc. are mentioned.

As an acrylic resin, an oligomer and a polymer obtained by polymerizing acrylic acid ester are referred to, and a homopolymer or a copolymer may be used. In addition, commercially available ones can be used. For example, the Acridic (registered trademark) series by DIC Corporation, the ARFON (registered trademark) series by Toagosei Co., Ltd., etc. are mentioned.

Examples of the polyester urethane resin include Byron (registered trademark) UR series manufactured by Toyobo Co., Ltd.

(heterogeneous component (III))

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

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

It does not specifically limit as a fluorine compound, A commercially available thing can be used. For example, Megafac (registered trademark) series by DIC Corporation etc. are mentioned.

As a long-chain alkyl compound, the acrylic polymer which copolymerized the long-chain alkyl acrylate, the graft polymer which grafted the long-chain alkyl, the block polymer which added the long-chain alkyl to the terminal, etc. are mentioned. Moreover, it is not specifically limited, A commercially available thing can be used. For example, the Tespine (registered trademark) series by Hitachi Chemical Co., Ltd., the Pyroil (registered trademark) by Lion Specialty Chemicals, etc. are mentioned.

Examples of active energy rays include infrared rays, visible rays, ultraviolet rays, electromagnetic waves such as X-rays, electron beams, ion beams, neutron rays, and particle rays such as α rays. desirable.

The atmosphere at the time of irradiation with the said active energy ray may be under nitrogen gas atmosphere in general air. In a nitrogen gas atmosphere, the radical reaction proceeds smoothly by reducing the oxygen concentration and the modulus of elasticity of the release layer can be improved.

(photopolymerization initiator)

When using a radical polymerization type compound for the release layer of the present invention, it is preferable to add a photopolymerization initiator. As the photopolymerization initiator, specifically, benzophenone, acetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, benzoin dimethyl Ketal, 2,4-diethylthioxanthone, 1-hydroxycyclohexylphenylketone, benzyldiphenylsulfide, tetramethylthiurammonosulfide, azobisisobutyronitrile, benzyl, dibenzyl, diacetyl, β-chloroanthraquinone, (2,4,6-trimethylbenzyldiphenyl)phosphine oxide, 2-benzothiazole-N,N-diethyldithiocarbamate, and the like. 2-Hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methylpropan-1-one, which is considered to be particularly excellent in surface curability , 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, especially 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 independently and may be used in combination of 2 or more type.

The addition amount of the photopolymerization initiator is not particularly limited, but it is preferably contained, for example, 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 having a particle diameter of 1 μm or less, but from the viewpoint of pinhole generation, it is preferable not to contain particles or the like that form protrusions.

To the release layer in the present invention, additives such as an adhesion improver and an antistatic agent may be added as long as the effect of the present invention is not impaired. In addition, in order to improve adhesion with a substrate, it is also preferable to pre-treat anchor coating, corona treatment, plasma treatment, atmospheric pressure plasma treatment, etc. to the polyester film surface before providing a release coating layer.

In the present invention, the thickness of the release layer may be set according to its purpose of use, and is not particularly limited, but is preferably in the range of 0.2 to 3.5 μm for the release layer after curing, more preferably 0.5 to 3.0 μm. am. 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 modulus of elasticity of the release layer is improved, so that good peeling performance is obtained, which is preferable. In addition, if the thickness is 3.5 μm or less, even if the thickness of the release film is thin, it is difficult to cause curling, and thus, it is preferable because it does not cause poor running performance during molding and drying of the ceramic green sheet.

It is preferable that the release film of this invention has moderate unevenness on the surface of a release layer. Therefore, it is preferable that the area surface average roughness (Sa) of the surface of a release layer is 5-40 nm. Further, it is more preferable that the above Sa is satisfied and the maximum protrusion height (Rp) on the surface of the release layer is 60 nm or less. Further, the area surface average roughness (Sa) is preferably 5 to 20 nm, more preferably 8.5 to 20 nm. At the same time, it is particularly preferable that the maximum projection height Rp is 50 nm or less. When the area surface roughness Sa is 5 nm or more, zipping is reduced during peeling of the ceramic green sheet, and even an ultra-thin green sheet can be easily peeled without damage. In addition, when the area surface roughness Sa is 40 nm or less, it is sufficiently smaller than the grain size of the ceramic and does not affect the surface shape of the green sheet. When the above Sa is satisfied and the maximum protrusion height Rp on the surface of the mold release layer is 60 nm or less, the possibility of generating pinhole defects is reduced, which is preferable. The maximum projection height Rp is preferably small, but since the area surface average roughness Sa is adjusted to 5 nm or more, the maximum projection height Rp may also be 5 nm or more, or 10 nm or more. In order to adjust the surface roughness (Sa) of the release layer or the maximum protrusion height (Rp) within the range, various factors are involved, but mainly the surface layer A of the polyester film or the single-layer polyester film substantially removes the inorganic particles. Since it is not contained, the roughness of the surface on which the release layer is laminated is small, the release layer has an energy ray curable compound (I) having three or more reactive groups in one molecule, and the energy ray curable compound (I) as sea components. It can be said that it is related to containing and curing resin (II) which is incompatible with the energy ray curable compound (I) and serves as an island component. The method of adjusting the surface roughness (Sa) or the maximum protrusion height (Rp) of the release layer within the appropriate range as described above is not particularly limited, but is mainly a combination of energy ray-curable compound (I) and resin (II) materials or containing It can be preferably achieved by adjusting the ratio.

It is preferable that the static friction coefficient of the surface of the release layer of the release layer film of the present invention is 0.05 or more and 2.00 or less. More preferably, they are 0.1 or more and 1.00 or less, and still more preferably 0.1 or more and 0.50 or less. If the static friction coefficient is in the above range, the roll of the coating equipment and the surface of the release layer slide well and excessive force is not applied, so that scratches on the surface of the release layer are reduced and damage to the green sheet can be reduced, A good green sheet surface is obtained.

Moreover, it is preferable that the kinetic friction coefficient of the surface of the release layer of the release film of this invention is 1.00 or less. If it is the above range, tension abnormality does not occur in a process, and a favorable green sheet surface is obtained.

Adjusting the range of the coefficient of static friction and the coefficient of kinetic friction of the surface of the release layer is related to the range of surface roughness (Sa) or maximum protrusion height (Rp) of the release layer, and the adjustment method is not particularly limited. , It can be preferably achieved mainly by adjusting the combination of the materials of the energy ray-curable compound (I) and the resin (II) or the content ratio.

In the present invention, the method for forming the release layer is not particularly limited, and a coating solution in which a release compound is dissolved or dispersed is spread on one side of a polyester film as a base material by application or the like, and the solvent or the like is removed by drying. , a method of curing is used.

The drying temperature of solvent drying in the case of applying the release layer of the present invention on a base film by solution application 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. Moreover, it is preferable to advance a hardening reaction by irradiating an active energy ray after solvent drying. As the active energy ray used at this time, ultraviolet rays, electron beams, X rays, etc. can be used, but ultraviolet rays are preferred because they are easy to use. The amount of ultraviolet rays to be irradiated is preferably 30 to 300 mJ/cm ² in terms of light amount, more preferably 30 to 200 mJ/cm ² . By setting it as 30 mJ/cm ^<2> or more, hardening of a composition fully advances, and since the speed|rate at the time of processing can be improved by setting it as 300 mJ/cm ^<2> or less, economically, a release film can be produced, and it is preferable.

In the present invention, the surface tension of the coating solution at the time of applying the release layer is not particularly limited, but is preferably 30 mN/m or less. By adjusting the surface tension as described above, the wettability after coating can be improved, and unevenness on the surface of the coated 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, or a spray coating method Conventionally known methods such as , air knife coating method, etc. can be used.

Example

Examples are given below to explain the present invention in detail, 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, hereafter, a weight average molecular weight may simply be described as Mw.

(1) base film thickness

Using a millitron (electronic microindicator), 4 square samples with a side of 5 cm were cut out from 4 random locations of the film to be measured, and 5 points per sheet (total of 20 points) were 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 Filmetrix). (The refractive index of the release layer is calculated as 1.52)

(3) area surface roughness (Sa), maximum projection height (Rp)

It is a value measured under the following conditions using a non-contact surface shape measurement system (VertScan R550H-M100, manufactured by Ryokka System Co., Ltd.). The area surface average roughness (Sa) adopted the average value of 5 measurements, and the maximum projection height (Rp) was measured 7 times and used the maximum value of 5 times excluding the maximum and minimum values.

(Measuring conditions)

・Measurement mode: WAVE mode

・Objective lens: 50x

・0.5×Tube lens

(analysis condition)

Face correction: 4th correction

Interpolation processing: full interpolation

(4) Evaluation of pinholes in ceramic green sheets

A composition containing the following materials was stirred and mixed, and dispersed for 60 minutes using a bead mill using 0.5 mm diameter zirconia beads as a dispersion medium to prepare a ceramic slurry.

76.3 parts by mass of toluene

76.3 parts by mass of ethanol

Barium titanate (HPBT-1 manufactured by Fuji Titanium Co., Ltd.) 35.0 parts by mass

3.5 parts by mass of polyvinyl butyral

(Srec (registered trademark) BM-S made by Sekisui Kagaku High School)

DOP (dioctyl phthalate) 1.8 parts by mass

Next, the release surface of the release film sample was applied using an applicator so that a dried ceramic green sheet had a thickness of 0.8 μm, and after drying at 90° C. for 2 minutes, the release film was peeled off to obtain a ceramic green sheet.

In the central region of the obtained ceramic green sheet in the film width direction, light was projected from the surface opposite to the coated surface of the ceramic slurry in a range of 25 cm ² , and the occurrence of pinholes through which light passed was observed, and visually determined based on the following criteria did The measurement was performed 5 times and the average value was adopted.

○: Almost no pinholes (standard: 2 or less pinholes per measurement area)

△: occurrence of pinholes (standard: 3 or more pinholes per measurement area, 5 or less)

×: There are many occurrences of pinholes (standard: 6 or more pinholes per measurement area)

(5) Evaluation of damage to ceramic green sheet

The release film with the ceramic green sheet produced by the above method was cut into a width of 30 mm and a length of 80 mm, and was used as a sample for measuring peel force. After static neutralization using a static eliminator (SJ-F020, manufactured by Keyence Corporation), using a peel tester (VPA-3, manufactured by Kyowa Science and Technology Co., Ltd.), a peeling angle of 30 degrees, a peeling temperature of 25 ° C., and a peeling speed of 10 m/ Peeled at min. As the peeling direction, a double-sided adhesive tape (Nitto Denko Co., Ltd., No. 535A) is attached on the SUS plate attached to the peel tester, and the release film is fixed in such a way that the ceramic green sheet side is adhered to the double-sided tape thereon, and the release film is released. It was peeled off in the form of tensioning the film side. The surface of the ceramic green sheet after peeling, which was in contact with the release film, was observed 100 times with a scanning electron microscope in the area of 1250 μm × 900 μm in the central region in the film width direction, and the average value of 10 measurements was adopted. It was visually determined according to the following criteria.

○: No damage at the time of peeling (standard: no occurrence of cracks or deformation)

△: Hardness damage at the time of peeling (standard: 1 or more cracks and deformations per measurement area, 3 or less)

×: There is moderate damage at the time of peeling (standard: 4 or more cracks and deformations)

In addition, the peeling angle in this evaluation method refers to the angle of the direction in which a release film is pulled with respect to the axis|shaft of the evaluation sample fixed to the peel tester. Peeling temperature is the temperature when the release film fixed using the heater type stage system attached to an apparatus is heated. Using a handy-type thermometer (HD-1400E, manufactured by Anritsu Engineering & Construction Co., Ltd.), after confirming that the measurement sample had reached the appropriate temperature, peeling was performed.

(6) static friction coefficient, kinetic friction coefficient

Static friction coefficient (μs) and kinetic friction coefficient (μd) of the contact surface when the release layer surface of the film and the SUS plate are overlapped in contact using a Tensilon universal tester (manufactured by A&D Co., Ltd., RTG-1210) ) was measured under the following conditions according to JIS K-7125.

Test piece: width 50 mm × length 60 mm

Load: 4.4kg

Test speed: 200mm/min

Friction material: SUS plate

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

As the esterification reaction apparatus, a continuous esterification reaction apparatus including a three-stage complete mixing tank having a stirrer, a partial condenser, a raw material inlet, and a product outlet was used. TPA (terephthalic acid) is 2 tons/hour, EG (ethylene glycol) is 2 moles per 1 mole of TPA, and antimony trioxide is used in an amount such that the Sb atom is 160 ppm with respect to the produced PET. 1 It was continuously supplied to an esterification reaction can and reacted at 255°C with an average residence time of 4 hours at normal pressure. Subsequently, the reaction product in the first esterification reaction can is continuously taken out of the system and supplied to the second esterification reaction can, and the EG distilled off from the first esterification reaction can into the second esterification reaction can is produced EG containing magnesium acetate tetrahydrate supplied at 8% by mass and containing magnesium acetate tetrahydrate in an amount such that the Mg atom is 65 ppm with respect to product PET, and TMPA (trimethyl phosphate) in an amount such that P atom is 40 ppm with respect to product PET. EG containing The solution was added and reacted at 260° C. with an average residence time of 1 hour at normal pressure. Then, the reaction product in the second esterification reaction can was continuously taken out of the system and supplied to the third esterification reaction can, and averaged at a pressure of 39 MPa (400 kg/cm ² ) using a high-pressure disperser (manufactured by Nippon Seki Co., Ltd.). 0.2% by mass of porous colloidal silica having an average particle size of 0.9 μm subjected to dispersion treatment for 5 passes, and 0.4% by mass of synthetic calcium carbonate having an average particle size of 0.6 μm in which 1 mass% of ammonium salt of polyacrylic acid is adhered per calcium carbonate were added as 10% EG slurries, respectively, and reacted at 260°C with an average residence time of 0.5 hours at normal pressure. The esterification reaction product generated in the third esterification reaction can is continuously supplied to a three-stage continuous polycondensation reactor for polycondensation, and 95% of the esterification product is filtered through a filter made of sintered stainless steel fibers having a cut diameter of 20 μm. After performing, ultrafiltration was performed, extruded in water, cooled, and then cut into chips to obtain a PET chip 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 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 (2)).

(Preparation of polyethylene terephthalate pellets (PET (3)))

The same procedure as in PET (1) was performed except that the type and content of the particles of PET (I) were changed to 0.75 mass% of synthetic calcium carbonate having an average particle diameter of 0.9 µm in which 1 mass% of the ammonium salt of polyacrylic acid was deposited per calcium carbonate. A PET chip was obtained (hereinafter abbreviated as PET (3)). The lubricant content in the PET chip was 0.75% by mass.

(Preparation of laminated film X1)

After drying, these PET chips were melted at 285°C, melted at 290°C by a separate melt extruder extruder, and a filter obtained by sintering stainless steel fibers having a 95% cut diameter of 15 μm, and a filter having a 95% cut diameter of 15 μm A filter made of sintered phosphorus stainless steel particles is filtered in two stages, joined in the feed block, and PET (1) is the surface layer B (semi-release side layer) and PET (2) is the surface layer A (release side layer). It is laminated to be stacked, 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 polyethylene terephthalate having an intrinsic viscosity of 0.59 dl/g. got a sheet The layer ratio was adjusted so that PET (1)/(2) = 60%/40% by calculating the discharge amount of each extruder. Next, after heating this unstretched sheet with an infrared heater, it was stretched 3.5 times in the machine direction at a roll temperature of 80°C by a difference in speed between the rolls. After that, it was guided by a tenter and stretched 4.2 times in the transverse direction at 140°C. Subsequently, heat treatment was performed at 210°C in a heat setting zone. Thereafter, a 2.3% relaxation treatment 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.

(Preparation of laminated film X2)

The thickness was adjusted by changing the speed at the time of casting, without changing the layer structure and stretching conditions same as laminated|multilayer film X1, and the biaxially stretched polyethylene terephthalate film X2 of 25 micrometers thickness was obtained. Sa of the surface layer A of the obtained film X2 was 3 nm, and Sa of the surface layer B was 29 nm.

(laminated film X3)

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

(Example 1)

On the surface layer A of the laminated film X1, coating liquid 1 of the following composition was coated using reverse gravure so that the film thickness of the release layer after drying was 2.5 μm, dried at 90 ° C. for 30 seconds, and then applied with a high-pressure mercury lamp to 200 mJ / A release film for manufacturing an ultra-thin ceramic green sheet was obtained by irradiating UV light to a size of cm ² . The obtained release film was evaluated for release layer thickness, area surface roughness Sa, maximum protrusion height Rp, ceramic green sheet pinhole evaluation, ceramic green sheet damage evaluation, static friction coefficient, and kinetic friction coefficient.

(Coating liquid 1)

Compound (I) 100.00 parts by mass

(Dipentaerythritol hexaacrylate, A-DPH manufactured by Shin-Nakamura Chemical Industry Co., Ltd., solid content concentration 100%)

Resin (II) polyester resin 9.47 parts by mass

(Toyobo Co., Ltd. Byron (registered trademark) RV280, solid content concentration 100% 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)

Diluting solvent (MEK/toluene = 1/1) 459.79 parts by mass

(Example 2)

Resin (II) was changed to a polyester urethane resin (Vyron (registered trademark) UR1400 manufactured by Toyobo Co., Ltd., solid content concentration: 30% by mass), and the following coating liquid 2 was used. The solid content concentration of coating liquid 2 was reduced compared to coating liquid 1 of Example 1. It coated so that the release layer film thickness after drying might be set to 1.5 micrometers. A release film was obtained in the same manner as in Example 1 except that the coating liquid 2 was used and the coating was applied so that the thickness of the release layer after drying was 1.5 µm. The obtained release film was evaluated for release layer thickness, area surface roughness Sa, maximum protrusion height Rp, ceramic green sheet pinhole evaluation, ceramic green sheet damage evaluation, static friction coefficient, and kinetic friction coefficient.

(Coating liquid 2)

Compound (I) 100.00 parts by mass

(Dipentaerythritol hexaacrylate, A-DPH manufactured by Shin-Nakamura Chemical Industry Co., Ltd., solid content concentration 100%)

Resin (II) polyester urethane resin 31.50 parts by mass

(Toyobo Co., Ltd. Byron (registered trademark) UR1400, solid content concentration 30% by mass)

Release agent (III) 0.42 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)

Diluting solvent (MEK/toluene = 1/1) 975.42 parts by mass

(Example 3)

The following coating liquid 3, in which the proportion of the release agent (III) was increased compared to Example 2, was used. It coated so that the release layer film thickness after drying might be set to 1.8 micrometers. A release film was obtained in the same manner as in Example 1 except that the coating liquid 3 was used and the coating was applied so that the thickness of the release layer after drying was 1.8 µm. The obtained release film was evaluated for release layer thickness, area surface roughness Sa, maximum protrusion height Rp, ceramic green sheet pinhole evaluation, ceramic green sheet damage evaluation, static friction coefficient, and kinetic friction coefficient.

(Coating liquid 3)

Compound (I) 100.00 parts by mass

(Dipentaerythritol hexaacrylate, A-DPH manufactured by Shin-Nakamura Chemical Industry Co., Ltd., solid content concentration 100%)

Resin (II) polyester urethane resin 31.50 parts by mass

(Toyobo Co., Ltd. Byron (registered trademark) UR1400, solid content concentration 30% 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 100% by mass)

Diluting solvent (MEK/toluene = 1/1) 982.98 parts by mass

(Example 4)

Coating liquid 3 used in Example 3 was coated on the surface layer A of laminated film X2. A release film was obtained in the same manner as in Example 3 except that the laminated film X2 was used. The obtained release film was evaluated for release layer thickness, area surface roughness Sa, maximum protrusion height Rp, ceramic green sheet pinhole evaluation, ceramic green sheet damage evaluation, static friction coefficient, and kinetic friction coefficient.

(Example 5)

Coating liquid 3 used in Example 3 was coated on the surface layer A of laminated film X3. A release film was obtained in the same manner as in Example 3 except that the laminated film X3 was used. The obtained release film was evaluated for release layer thickness, area surface roughness Sa, maximum protrusion height Rp, ceramic green sheet pinhole evaluation, ceramic green sheet damage evaluation, static friction coefficient, and kinetic friction coefficient.

(Comparative Example 1)

Compared to Example 1, resin (II) is not included, and release agent (III) is changed to polyether-modified polydimethylsiloxane having an acryloyl group (BYK UV-3500, manufactured by Big Chemie Japan Co., Ltd., solid content concentration: 100%) Thus, the addition amount was increased, and the following coating solution 4 was used in which the dilution solvent was changed. A release film was obtained in the same manner as in Example 1 except that the coating liquid 4 was used and the coating was applied so that the thickness of the release layer after drying was 1.0 µm. The obtained release film was evaluated for release layer thickness, area surface roughness Sa, maximum protrusion height Rp, ceramic green sheet pinhole evaluation, ceramic green sheet damage evaluation, static friction coefficient, and kinetic friction coefficient.

(Coating liquid 4)

Compound (I) 100.00 parts by mass

(Dipentaerythritol hexaacrylate, A-DPH manufactured by Shin-Nakamura Chemical Industry Co., Ltd., solid content concentration 100%)

Release agent (III) 1.00 parts by mass

(Acryloyl group-containing polyether-modified polydimethylsiloxane BYK UV-3500, manufactured by Big Chemie Japan Co., Ltd., solid content concentration 100%))

Photopolymerization initiator 5.00 parts by mass

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

Diluting solvent (IPA/MEK=3/1) 424.25 parts by mass

According to the release film for manufacturing a ceramic green sheet of the present invention, compared to the conventional release film for manufacturing a ceramic green sheet, the peeling force is not too heavy, the processability is excellent, and the release layer has no large protrusions, so the molded thickness is 1 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 ㎛ or less.

Claims (9)

A release film in which a release layer of 0.2 to 3.5 μm is laminated on at least one side of a polyester film directly or through another layer, wherein the area surface roughness (Sa) of the surface of the release layer is 5 to 40 nm and the maximum peak height (Rp) is less than 60 nm,
The release layer contains an energy ray-curable compound (I) having three or more reactive groups in one molecule, and the energy ray-curable compound (I) as a sea component, incompatible with the energy ray-curable compound (I), and an island component A release film for producing a ceramic green sheet obtained by curing a coating film containing at least a resin (II) and a release component (III). The compound (I) according to claim 1, wherein the compound (I) is an energy ray-curable monomer having three or more (meth)acryloyl groups in the molecule, and the resin (II) is a polyester resin, an acrylic resin, a urethane resin, a polyester urethane resin, A release film for producing a ceramic green sheet, which is at least one selected from the group consisting of polyimide-based resins, polyamide-imide-based resins, and cellulose-based resins. The release film for manufacturing a ceramic green sheet according to claim 1, wherein the release layer does not substantially contain inorganic particles. The polyester film according to claim 1, wherein the polyester film is a laminated polyester film comprising two or more layers including at least a surface layer A and a surface layer B on the opposite side to the surface layer A, and a release layer is laminated on the surface layer A, , A release film for producing a ceramic green sheet in which inorganic particles are not substantially contained in the surface layer A. The release film for producing a ceramic green sheet according to claim 4, wherein the surface layer B contains particles, the particles are silica particles and/or calcium carbonate particles, and the total content of the particles is 5000 to 15000 ppm with respect to the total mass of the surface layer B. . The release film for manufacturing a ceramic green sheet according to claim 1, wherein the polyester film does not substantially contain inorganic particles, and a coating layer containing particles is laminated on a side of the polyester film on which the release layer is not laminated. The method of claim 1, wherein the release layer forming coating liquid for forming the release layer further comprises a photopolymerization initiator,
The content of the energy ray-curable compound (I) in the solid content of the coating liquid for forming a release layer is 60 to 98% by mass,
The content of the resin (II) in the solid content in the coating liquid for forming a release layer is 1 to 40% by mass,
The content of the release component (III) in the solid content of the coating liquid for forming a release layer is 0.05 to 10% by mass, and the ceramic green wherein the total of components (I), (II), and (III) and photopolymerization initiator is 100% by mass. Release film for sheet manufacturing. The energy ray curable compound (I) according to claim 1, is an energy ray curable monomer having three or more (meth)acryloyl groups in a molecule,
Energy radiation curable monomers having three or more (meth)acryloyl groups in the molecule include isocyanuric acid triacrylate, glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate. ) Acrylates, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaeryth A release film for producing a ceramic green sheet comprising at least one selected from ritolpenta(meth)acrylate and dipentaerythritol hexa(meth)acrylate. A method for manufacturing a ceramic green sheet in which a ceramic green sheet is molded using the release film for manufacturing a ceramic green sheet according to any one of claims 1 to 8, wherein the molded ceramic green sheet has a thickness of 0.2 µm to 1.0 µm. Method for producing a ceramic green sheet, characterized in that.