JP2019161156A - Release film roll for manufacturing ceramic green sheet - Google Patents

Abstract

To provide a peeling film role for manufacturing a green sheet having an excellent prevention for generating a winding deviation in the case where a holding temperature of a release film roll changes.SOLUTION: In a release film roll for manufacturing a green sheet, the release film roll is wound on a core that an insulation value of a difference between a core outer diameter under 25°C and a core outer diameter after heating for one hour under 50°C is 0.1 mm or less, and the insulation value of the difference between the core outer diameter under 25°C and the core outer diameter after cooling for one hour under 5°C is 0.1 mm or less.

Description

  The present invention relates to a release film roll for producing a green sheet. More specifically, the present invention relates to a release film roll for producing a green sheet that does not cause winding deviation during film roll storage even when the release film is a thin film and has a smooth surface.

  Conventionally, a technique has been known in which the winding density is kept within a predetermined range to prevent winding deviation in a state in which the release film for green sheet production is wound, and to maintain flatness (for example, patent document) 1). However, when the green sheet is thinned, the conventional technology has large protrusions on the release surface and the back surface even if the winding density is kept within a certain range. There was a problem of getting worse.

  A technique has been known in which high smoothness of the outer surface of the release agent layer can be obtained by keeping the surface roughness of the release surface and the back surface within an appropriate range, and excellent release properties can be provided. (For example, refer to Patent Document 2). However, such a conventional technique is good in the winding state immediately after winding, but when the film roll temperature changes during storage and transportation, the winding of the film near the core becomes loose or tightened due to expansion and contraction of the core. As a result, there is a problem that winding deviation occurs. When the release film roll of the unwinding part used in the ceramic slurry coating has a winding shift, the meandering of the film occurs, and it may be difficult to uniformly coat and create the ceramic green sheet.

JP 2006-181992 A JP 2014082500 A

  The present invention has been made against the background of such prior art problems. That is, an object of the present invention is to provide an excellent release film roll for producing a green sheet that does not cause winding deviation even when the storage temperature of the release film roll changes.

As a result of intensive studies to achieve the above object, the present inventors have completed the present invention. That is, this invention consists of the following structures.
1. The absolute value of the difference between the core outer diameter at 25 ° C. and the core outer diameter after heating at 50 ° C. for 1 hour is 0.1 mm or less, and the core outer diameter at 25 ° C. and the core outer after cooling at 5 ° C. for 1 hour A release film roll for producing a green sheet, in which a release film is wound on a core having an absolute value of a difference from the diameter of 0.1 mm or less.
2. For the circumferential direction and the width direction of the core, the standard deviation when the core outer diameter at 25 ° C. is measured at 10 points each at different positions is 0.05 mm or less in both the circumferential direction and the width direction of the core. A release film roll for producing a green sheet according to the first aspect.
3. The film substrate constituting the release film is a polyester film, and the release film has a release layer on at least one side of the polyester film, and the surface average roughness (Sa) of the release layer surface is 7 nm. The release film roll for manufacturing a ceramic green sheet according to the first or second aspect described above.
4). The polyester film has a surface layer A substantially free of inorganic particles and an opposite surface layer B containing particles, and a release layer is provided on the surface layer A, and the surface layer B The release film roll for manufacturing a ceramic green sheet according to the third aspect, wherein the particles contained in the surface layer are silica particles and / or calcium carbonate particles, and the total amount of the particles is contained in the surface layer B at 5000 to 15000 ppm.
5). A method for producing a ceramic green sheet having a thickness of 0.2 μm to 1.0 μm, wherein the mold is wound around the release film roll for producing a ceramic green sheet according to any one of the first to fourth aspects. A method for producing a ceramic green sheet using a film.
6). A method for producing a ceramic capacitor, wherein the method for producing a ceramic green sheet according to the fifth aspect is adopted.

  According to the present invention, in the release film roll for producing a green sheet, even when the release film is a thin film and the surface is smooth and the storage temperature of the film roll changes, it is possible to prevent the occurrence of winding deviation. .

Hereinafter, the present invention will be described in detail.
The release film roll for producing ceramic green sheets of the present invention (hereinafter sometimes simply referred to as a release film roll) is a release film roll having a release layer on one side of a biaxially oriented polyester film that is a base film. is there.

(Polyester film)
The polyester constituting the polyester film preferably used as the base material in the present invention is not particularly limited, and a polyester film generally used as a base material for a release film can be used. Is preferably a crystalline linear saturated polyester composed of an aromatic dibasic acid component and a diol component, for example, polyethylene terephthalate, polyethylene-2,6-naphthalate, polybutylene terephthalate, polytrimethylene terephthalate, or these A copolymer having a resin component as a main component is more preferable, and a polyester film formed from polyethylene terephthalate is particularly preferable. In polyethylene terephthalate, the repeating unit of ethylene terephthalate is preferably 90 mol% or more, more preferably 95 mol% or more, and other dicarboxylic acid components and diol components may be copolymerized in a small amount, but from the viewpoint of cost. Those produced only from terephthalic acid and ethylene glycol are preferred. Moreover, you may add a well-known additive, for example, antioxidant, a light stabilizer, a ultraviolet absorber, a crystallizing agent, etc. within the range which does not inhibit the effect of the film of this invention. The polyester film is preferably a biaxially oriented polyester film for reasons such as high bidirectional elasticity.

  The intrinsic viscosity of the polyethylene terephthalate film is preferably 0.50 to 0.70 dl / g, and more preferably 0.52 to 0.62 dl / g. When the intrinsic viscosity is 0.50 dl / g or more, it is preferable because many breakage does not occur in the stretching process. On the other hand, when it is 0.70 dl / g or less, it is preferable because cutting property when cutting to a predetermined product width is good and dimensional defects do not occur. Moreover, it is preferable that the raw material is sufficiently vacuum dried.

  The manufacturing method of the polyester film in this invention is not specifically limited, The method generally used conventionally can be used. For example, the polyester can be melted with an extruder, extruded into a film, cooled with a rotary cooling drum to obtain an unstretched film, and the unstretched film can be obtained by biaxial stretching. A biaxially stretched film can be obtained by a method of sequentially biaxially stretching a uniaxially stretched film in the longitudinal direction or the transverse direction in the transverse direction or the longitudinal direction, or a method of simultaneously biaxially stretching an unstretched film in the longitudinal direction and the transverse direction. I can do it.

  In this invention, it is preferable that the extending | stretching temperature at the time of extending | stretching a polyester film shall be more than the secondary transition point (Tg) of polyester. It is preferable to stretch 1 to 8 times, particularly 2 to 6 times in the longitudinal and lateral directions.

  It is preferable that the said polyester film is 12-50 micrometers in thickness, More preferably, it is 15-38 micrometers, More preferably, it is 19-33 micrometers. If the thickness of the film is 12 μm or more, it is preferable that there is no risk of deformation due to heat during film production, processing steps, and molding. On the other hand, if the thickness of the film is 50 μm or less, the amount of the film discarded after use is not extremely increased, which is preferable in reducing the environmental load.

  The polyester film substrate may be a single layer or a multilayer of two or more layers, but is preferably a laminated 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 that can contain particles on the opposite surface of the surface layer A that does not substantially contain inorganic particles. As the laminated structure, when the layer on the side to which the release layer is applied is the A layer, the opposite layer is the B layer, and the core layer other than these is the C layer, the layer structure in the thickness direction is the release layer / A / B, or a laminated structure such as a release layer / A / C / B. Of course, the C layer may have a plurality of layers. Further, the surface layer B can contain no particles. In that case, it is preferable to provide a coating layer containing at least particles and a binder on the surface layer B in order to provide slipperiness for winding the film into a roll.

  In the polyester film substrate of the present invention, it is preferable that the surface layer A that forms 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, pinholes and the like are less likely to occur during molding of the laminated ultra-thin ceramic green sheet. Although it can be said that the region surface average roughness (Sa) of the surface layer A is preferably as small as possible, it may be 0.1 nm or more. Here, when providing the below-mentioned anchor coat layer etc. on the surface layer A, it is preferable that an inorganic particle is not included substantially in a coat layer, and the area | region surface average roughness (Sa) after coat layer lamination | stacking is the said range. It is preferable to enter. In the present invention, “substantially free of inorganic particles” means that the inorganic particles are not more than 50 ppm, preferably not more than 10 ppm, most preferably not more than the detection limit when the inorganic elements are quantified by fluorescent X-ray analysis. Means content. This means that even if inorganic particles are not actively added to the film, contaminants derived from foreign substances, raw material resin, or dirt attached to the line or equipment in the film manufacturing process will be peeled off and mixed into the film. This is because there are cases.

  In the polyester film substrate of the present invention, the surface layer B that forms the surface opposite to the surface on which the release layer is applied preferably contains particles from the viewpoint of the slipperiness of the film and the ease of air removal. It is preferable to use silica particles and / or calcium carbonate particles. The contained particle content is preferably 5000 to 15000 ppm in total in the surface layer B. At this time, it is preferable that the area | region surface average roughness (Sa) of the film of the surface layer B is the range of 1-40 nm. More preferably, it is the range of 5-35 nm. When the total of silica particles and / or calcium carbonate particles is 5000 ppm or more and Sa is 1 nm or more, when the film is rolled up, air can be released uniformly, and the winding shape is good and the flatness is good. This is suitable for the production of an ultrathin layer 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, the lubricant is less likely to agglomerate and coarse protrusions cannot be formed, so the quality is stable when manufacturing ultra-thin ceramic green sheets. It is preferable.

  As the particles contained in the layer B, inactive inorganic particles and / or heat-resistant organic particles other than silica and / or calcium carbonate can be used, but silica particles and / or from the viewpoint of transparency and cost. More preferably, calcium carbonate particles are used. Other inorganic particles that can be used include alumina-silica composite oxide particles and hydroxyapatite particles. Examples of the heat resistant organic particles include crosslinked polyacrylic particles, crosslinked polystyrene particles, and benzoguanamine particles. When silica particles are used, porous colloidal silica is preferable, and when calcium carbonate particles are used, light calcium carbonate surface-treated with a polyacrylic acid polymer compound is preferable from the viewpoint of preventing the lubricant from falling off. .

  The average particle size 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. If the average particle diameter of the particles is 0.1 μm or more, the slipperiness of the release film is good, which is preferable. Moreover, if an average particle diameter is 2.0 micrometers or less, there is no possibility that a pinhole may generate | occur | produce in the ceramic green sheet by the coarse particle of a mold release layer surface, and it is preferable.

  The surface layer B may contain two or more kinds of particles having different materials. Moreover, you may contain the same kind of particle | grains from which an average particle diameter differs.

  When the surface layer B does not contain particles, it is preferable that the surface layer B has a slipperiness with a coat layer containing particles. Although this coating layer is not specifically limited, It is preferable to provide with the in-line coating applied during film forming of a polyester film. When the surface layer B does not contain particles, and the surface layer B has a coat layer containing particles, the surface of the coat layer is a region for the same reason as the surface average roughness (Sa) of the surface layer B described above. The surface average roughness (Sa) is preferably in the range of 1 to 40 nm. More preferably, it is the range of 5-35 nm.

  From the viewpoint of reducing pinholes, it is preferable not to use a regenerated raw material or the like for the surface layer A, which is a layer on the side where the release layer is provided, from the viewpoint of reducing pinholes.

  The thickness ratio of the surface layer A, which is the layer on the side where the release layer is provided, is preferably 20% to 50% of the total thickness of the base film. If it is 20% or more, the influence of particles contained in the surface layer B or the like is not easily received from the inside of the film, and the area surface average roughness Sa is easy to satisfy the above range, which is preferable. When the thickness is 50% or less of the total thickness 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.

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

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

  The ceramic green sheet to be applied and molded on the release layer is wound into a roll together with the release film after application and molding. At this time, the ceramic green sheet surface is wound up in a state in which an anti-release surface (sometimes referred to as an easy-slip surface) having the slipperiness of the release film is in contact. In order not to generate defects on the surface of the ceramic green sheet, the smooth surface needs to be reasonably flat, the area surface average roughness (Sa) is 1 nm to 25 nm, and the maximum protrusion height (P) is It is preferable that it is 60 nm or more and 500 nm or less.

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

  As the release layer in the present invention, for example, a silicone resin is a resin having a silicone structure in the molecule, and examples thereof include curable silicone, silicone graft resin, and modified silicone resins such as alkyl-modified. From the standpoint of the above, it is preferable to use a reactive cured silicone resin. As the reactive cured silicone resin, an addition reaction type, a condensation reaction type, an ultraviolet ray or electron beam curing type, or the like can be used. More preferably, a low-temperature curable addition reaction system that can be processed at a low temperature, and an ultraviolet ray or electron beam curing system are preferable. By using these materials, the polyester film can be processed at a low temperature. Therefore, there is little thermal damage to the polyester film during processing, a polyester film with high flatness can be obtained, and pinholes and other defects can be reduced even when manufacturing ultra-thin ceramic green sheets with a thickness of 0.2 to 1.0 μm. Can do.

  Examples of the addition reaction type silicone resin include those obtained by reacting and curing polydimethylsiloxane having a vinyl group introduced into the terminal or side chain thereof with hydrodienesiloxane using a platinum catalyst. At this time, it is more preferable to use a resin that can be cured at 120 ° C. within 30 seconds because processing at a low temperature is possible. As an example, low temperature addition curing type (LTC1006L, LTC1056L, LTC300B, LTC303E, LTC310, LTC314, LTC350G, LTC450A, LTC371G, LTC750A, LTC755A, LTC85A, L85 type, UV85B, LTC760A, etc. -510, BY24-561, BY24-562, etc.), Shin-Etsu Chemical Co., Ltd. solvent addition + UV curing type (X62-5040, X62-5065, X62-5072T, KS5508 etc.), dual cure curing type (X62-2835, X62) -2834, X62-1980, etc.).

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

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

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

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

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

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

  The release layer in the present invention can contain particles having a particle size of 1 μm or less. However, it is preferable not to substantially contain those that form protrusions such as particles from the viewpoint of pinhole generation.

  In the release layer in the present invention, an additive such as an adhesion improver or an antistatic agent may be added. In order to improve the adhesion to the substrate, it is also preferable to pretreat the polyester film surface with an anchor coat, corona treatment, plasma treatment, atmospheric pressure plasma treatment or the like before providing the release layer.

  In the present invention, the thickness of the release layer may be set according to the purpose of use, and is not particularly limited. Preferably, however, the thickness of the release layer after curing is within a range of 0.005 to 2.0 μm. Good. When the thickness of the release layer is 0.005 μm or more, the peeling performance is maintained, which is preferable. Moreover, it is preferable that the thickness of the release layer is 2.0 μm or less because the curing time does not become too long, and there is no possibility of uneven thickness of the ceramic green sheet due to a decrease in planarity of the release film. In addition, since the curing time does not become too long, the resin constituting the release layer does not have a possibility of agglomeration and there is no possibility of forming protrusions.

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

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

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

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

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

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

(Winding core)
After coating the release layer, it is wound around a winding core and used as a release film roll for forming a ceramic green sheet, which will be described later. Various cores such as paper, plastic and metal are used as the winding core of the winding core portion used for winding the film after coating the release layer. As the core used in the present invention, the absolute value of the difference between the core outer diameter at 25 ° C. and the core outer diameter after heating for 1 hour at 50 ° C. is 0.1 mm or less, and the core outer diameter at 25 ° C. The core whose absolute value of the difference from the core outer diameter after cooling for 1 hour at 5 ° C. is 0.1 mm or less is preferable. If the change in the outer diameter of the core after heating and cooling from room temperature is 0.1 mm or less, the film is wound around the core due to the change in the outer diameter of the core when the film roll storage temperature after winding the film is changed. This is preferable because it is possible to prevent the winding core portion from being loosened due to loosening and tightening. More preferably, the absolute value of the difference between the core outer diameters before and after heating and before and after cooling is 0.06 mm or less. The absolute value of the difference between the core outer diameters before and after heating and before and after cooling is most preferably 0 mm, but may be 0.005 mm or more, or 0.01 mm or more.

  It is preferable that the standard deviation when the core outer diameter is measured at 10 points at 25 ° C. in both directions in the circumferential direction and the width direction of the winding core is 0.05 mm or less in both directions. . The standard deviation is more preferably 0.03 mm or less. If the standard deviation is 0.05 mm or less, the stress applied to the film in the vicinity of the core immediately after winding becomes uniform in the width direction of the film and winding deviation is less likely to occur. The standard deviation is preferably closer to 0 mm, but may be 0.001 mm or more.

  As for the diameter size of the winding core, 3 inch, 6 inch, 8 inch, 11 inch, etc. are generally used, but it is not particularly limited to these sizes, and cores of various sizes are used. can do.

  It is preferable to use a plastic core so that the winding core can be heated and changed in size before and after cooling, and the standard deviation in the circumferential direction and the width direction is within a predetermined range. Of these, bakelite and FRP are particularly preferred. FRP (Fiber Reinforced Plastics) is a core that uses fibers in addition to the main resin to improve strength. The main resin is not limited to a specific type, and is not limited to epoxy resin, unsaturated polyester resin, vinyl Examples thereof include thermosetting resins such as ester resins, phenol resins, diallyl phthalate resins, and melamine resins. Examples of the fiber used include fibers such as glass, epoxy, polyester, carbon, and aramid. In addition, FRP may be called FWP (Fiber Winding Plastics).

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

  The release film roll for producing a ceramic green sheet of the present invention is used for producing such a multilayer ceramic capacitor. For example, it is manufactured as follows. First, the release film wound up by the release film roll in this invention is used as a carrier film, and the ceramic slurry for comprising a ceramic body is apply | coated and dried. A conductive layer for forming the first or second internal electrode is printed on the coated and dried ceramic green sheet. A ceramic green sheet, a ceramic green sheet printed with a conductive layer for constituting the first internal electrode, and a ceramic green sheet printed with a conductive layer for constituting the second internal electrode are appropriately laminated and pressed. Thus, a mother laminate is obtained. The mother laminated body is divided into a plurality of parts to produce a raw ceramic body. A ceramic body is obtained by firing a raw ceramic body. Thereafter, the multilayer ceramic capacitor can be completed by forming the first and second external electrodes.

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

(1) Surface characteristics of coated film It is a value measured under the following conditions using a non-contact surface shape measurement system (VertScan R550H-M100). The average surface roughness (Sa) and the average length (RSm) of the roughness curve elements were measured using an average of 5 measurements, and the maximum protrusion height (P) was the maximum of 5 measurements.
(Measurement condition)
・ Measurement mode: WAVE mode ・ Objective lens: 50 × ・ 0.5 × Tube lens ・ Measurement area 187 × 139 μm
(Analysis conditions)
・ Surface correction: 4th order correction ・ Interpolation processing: Complete interpolation

(2) Release layer thickness measurement A value obtained by observing and calculating a cross section of the film when the release film was cut into an arbitrary size with a transmission electron microscope was defined as a release layer thickness.

(3) Measurement of variation in outer diameter depending on the position of the winding core in the width direction and circumferential direction Measure the outer diameter using calipers at 10 points by changing the position in the width direction and circumferential direction of the core to be used. Variation (standard deviation σ) was calculated from the measurement result (unit: mm).

(4) Measurement of outer diameter change Δa before and after heating of winding core A specific position of each core was marked in advance, and the outer diameter was measured at room temperature of 25 ° C. Immediately after putting the measured core into a gear oven set at 50 ° C. for 1 hour and taking it out, the outer diameter of the marking part was measured, and the change in outer diameter before and after heating at 50 ° C. was calculated. The same measurement was performed 5 times, the average value was calculated, and the outer diameter change amount Δa was set (unit: mm).

(5) Measurement of change in outer diameter Δb before and after cooling of take-up core A specific position of each core was marked in advance, and the outer diameter was measured at room temperature of 25 ° C. Immediately after putting the measured core into a temperature-controlled room set at 5 ° C. for 1 hour and taking it out, the outer diameter of the marking part was measured, and the change in outer diameter before and after cooling at 5 ° C. was calculated. The same measurement was performed 5 times, the average value was calculated, and the outer diameter change amount Δb was set (unit: mm).

(6) Measurement of film roll winding deviation (immediately after winding)
The film after mold release processing was wound up to obtain a film roll. The deviation of the end face of the wound film roll was measured using a caliper.
Winding shape ○: The amount of winding deviation of the end face is less than 3 mm.
Winding form x: The amount of winding deviation of the end face is in the range of 3 mm to 5 mm.
Winding form xx: The amount of winding deviation of the end face exceeds 5 mm.

(7) Film roll measurement (14 days after winding)
The film after mold release processing was wound up to obtain a film roll. The wound film roll was stored alternately in a temperature-controlled room set at 5 ° C. for 1 day and stored in a temperature-controlled room set at 50 ° C. for 1 day alternately, and the film roll was stored for a total of 14 days. The shift of the film roll end face after storage for 14 days was measured using calipers.
Winding shape ○: The amount of winding deviation of the end face is less than 3 mm.
Winding form x: The amount of winding deviation of the end face is in the range of 3 mm to 5 mm.
Winding form xx: The amount of winding deviation of the end face exceeds 5 mm.

(8) Evaluation of pinhole and thickness variation of ceramic green sheet The following composition of materials is stirred and mixed, and dispersed for 2 hours using a paint shaker using 2.0 mm glass beads as a dispersion medium to obtain a ceramic slurry. It was.
Toluene 22.5% by mass
Ethanol 22.5% by mass
Barium titanate (HPBT-1 manufactured by Fuji Titanium) 50.0 mass%
Polyvinyl butyral (Sekisui Chemical Co., Ltd. ESREC BH-3) 5.0 mass%
Next, the slurry after drying is applied to the release surface of the release film sample using an applicator so that the dried slurry has a thickness of 0.5 μm, dried at 90 ° C. for 1 minute, and then the slurry surface and the smoothing coating layer surface are overlapped. After applying a load of 1 kg / cm ² for 1 minute, the release film was peeled off to obtain a ceramic green sheet.
In the central region in the film width direction of the obtained ceramic green sheet, light was applied from the opposite side of the ceramic slurry coating surface within a range of 25 cm ² , and the occurrence of pinholes through which light was transmitted was observed. Visual judgment was made.
○: No occurrence of pinholes, variation in thickness No particular problem ×: Generation of pinholes and / or thickness variation is conspicuous

(Preparation of polyethylene terephthalate pellets (PET (I)))
As the esterification reaction apparatus, a continuous esterification reaction apparatus comprising a three-stage complete mixing tank having a stirrer, a partial condenser, a raw material charging port and a product outlet was used. TPA (terephthalic acid) is 2 tons / hour, EG (ethylene glycol) is 2 moles per mole of TPA, antimony trioxide is made into an amount that makes Sb atoms 160 ppm with respect to the produced PET, and these slurries are ester Was continuously supplied to the first esterification reactor of the chemical reaction apparatus, and allowed to react at 255 ° C. at an average residence time of 4 hours at normal pressure. Next, the reaction product in the first esterification reaction can is continuously taken out of the system and supplied to the second esterification reaction can, and is distilled off from the first esterification reaction can in the second esterification reaction can. EG solution containing 8 mass% of EG with respect to the generated PET, and further containing EG solution containing magnesium acetate tetrahydrate in an amount of 65 ppm of Mg atoms relative to the generated PET, and 40 ppm of P atoms relative to the generated PET An EG solution containing a quantity of TMPA (trimethyl phosphate) was added and reacted at 260 ° C. at normal pressure for an average residence time of 1 hour. Next, the reaction product of the second esterification reaction can was continuously taken out of the system and supplied to the third esterification reaction can, and 39 MPa (400 kg / cm ² ) using a high pressure disperser (manufactured by Nippon Seiki Co., Ltd.). An average particle of 0.2 mass% of porous colloidal silica having an average particle diameter of 0.9 μm and an ammonium salt of polyacrylic acid adhered to 1 mass% of calcium carbonate, which was dispersed at an average number of treatments of 5 passes under the pressure of While adding 0.4% by mass of synthetic calcium carbonate having a diameter of 0.6 μm as an EG slurry of 10%, the reaction was carried out at 260 ° C. at an average residence time of 0.5 hours at normal pressure. The esterification reaction product produced in the third esterification reaction can was continuously supplied to a three-stage continuous polycondensation reaction apparatus to perform polycondensation, and sintered with a stainless steel fiber having a 95% cut diameter of 20 μm. After filtering with a filter, ultrafiltration was performed and extruded into water, and after cooling, it was cut into chips to obtain PET chips with an intrinsic viscosity of 0.60 dl / g (hereinafter referred to as PET (I)). . The lubricant content in the PET chip was 0.6% by mass.

(Preparation of polyethylene terephthalate pellets (PET (II)))
On the other hand, in the production of the above PET chip, a PET chip having an intrinsic viscosity of 0.62 dl / g containing no particles such as calcium carbonate and silica was obtained (hereinafter abbreviated as PET (II)).

(Manufacture of laminated film Z)
These PET chips were dried, melted at 285 ° C., melted at 290 ° C. with a separate melt extruder extruder, sintered with stainless steel fibers having a 95% cut diameter of 15 μm, and a 95% cut diameter Two-stage filtration of a filter obtained by sintering 15 μm stainless steel particles is performed and merged in a feed block, so that PET (I) becomes an anti-release surface side layer and PET (II) becomes a release surface side layer. And then extruded (casting) into a sheet at a speed of 45 m / min, electrostatically adhered and cooled on a casting drum at 30 ° C. by an electrostatic adhesion method, and unstretched with an intrinsic viscosity of 0.59 dl / g A polyethylene terephthalate sheet was obtained. The layer ratio was adjusted so that PET (I) / (II) = 60% / 40% in the discharge amount calculation of each extruder. Next, this unstretched sheet was heated with an infrared heater, and then stretched 3.5 times in the longitudinal direction at a roll temperature of 80 ° C. due to the speed difference between the rolls. Thereafter, the film was guided to a tenter and stretched 4.2 times in the transverse direction at 140 ° C. Subsequently, it heat-processed at 210 degreeC in the heat setting zone. Thereafter, a relaxation treatment of 2.3% was performed in the transverse direction at 170 ° C. to obtain a biaxially stretched polyethylene terephthalate film Z having a thickness of 31 μm. Sa of the release surface side layer of the obtained film Z was 2 nm, and Sa of the anti-release surface side layer was 28 nm.

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

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

(Releasing agent solution X-3)
100 parts by mass of dipentaerythritol hexaacrylate (product name: A-DPH, manufactured by Shin-Nakamura Chemical Co., Ltd., solid content: 100% by mass), which is a binder made of a photo-radical curable substance, and an acryloyl group-containing polyether, which is a mold release agent 1.0 part by mass of modified polydimethylsiloxane (product name: BYK-UV3500, manufactured by Big Chemy Japan, solid content 100% by mass),
Photoradical polymerization initiator methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one 5.0 parts by mass (Product name: IRGACURE (registered trademark) 907, manufactured by BASF, active ingredient 100 % By weight) was diluted with a toluene / methyl ethyl ketone (= 1: 1) solution to prepare a release agent solution having a solid content of 20% by weight.

Example 1
(Formation of release layer, winding around core)
On the surface of the layer formed of PET (II) of the laminated film Z obtained above, the release agent solution X-1 was applied with a reverse gravure coater so that the thickness after drying was 0.05 μm, and then , Dried with hot air at 130 ° C. for 30 seconds to form a release layer, and under conditions of a winding tension of 140 N / m, a winding surface pressure of 300 N / m, and a winding speed of 150 m / min, a width of 1,500 mm, A release film roll for producing a ceramic green sheet was obtained by winding it on a film roll having a length of 6,000 m. A 3-inch bakelite core (Chiyoda Kogyo Co., Ltd.) was used as the winding core. Immediately after winding and after 14 days, the winding shape was excellent with no winding deviation.

(Example 2)
(Formation of release layer, winding around core)
A release film roll for producing a ceramic green sheet was obtained in the same manner as in Example 1 except that the core used in the winding was changed to an FRP (Fiber reinforced plastics) core (Kurimoto Corporation). Immediately after winding and after 14 days, the winding shape was excellent with no winding deviation.

(Example 3)
(Formation of release layer, winding around core)
On the surface of the layer formed of PET (II) of the laminated film Z obtained above, the release agent solution X-2 was applied with a reverse gravure coater so that the thickness after drying was 0.05 μm, and then After drying with hot air at 90 ° C. for 30 seconds, immediately irradiated with ultraviolet rays (300 mJ / cm ² ) with an electrodeless lamp (H bulb manufactured by Fusion Co., Ltd.) to form a release layer and release the ceramic green sheet A film roll was obtained. A bakelite core (Chiyoda Kogyo Co., Ltd.) was used as the winding core. Immediately after winding and after 14 days, the winding shape was excellent with no winding deviation.

Example 4
(Formation of release layer, winding around core)
On the surface of the layer formed of PET (II) of the laminated film Z obtained above, the release agent solution X-3 was applied with a reverse gravure coater so that the thickness after drying was 1.0 μm, and then After drying with hot air at 90 ° C. for 30 seconds, immediately irradiated with ultraviolet rays (300 mJ / cm ² ) with an electrodeless lamp (H bulb manufactured by Fusion Co., Ltd.) to form a release layer and release the ceramic green sheet A film roll was obtained. A bakelite core (Chiyoda Kogyo Co., Ltd.) was used as the winding core. Immediately after winding and after 14 days, the winding shape was excellent with no winding deviation.

(Comparative Example 1)
A ceramic is formed in the same manner as in Example 1 except that the film for forming the release layer is changed to E5000-25 μm (manufactured by Toyobo) instead of the laminated film Z, and the core is an ABS core instead of the bakelite core. A release film roll for producing a green sheet was obtained. E5000 contained particles inside the film, and Sa on the surface of the E5000 on the side where the release layer was formed was 0.027 μm, and Sa on the reverse release surface where the release layer was not laminated was 0.031 μm. Although the winding shape after release processing was good, winding deviation occurred in the core part after 14 days storage. Moreover, since the surface roughness of the release surface of the film was large, pinholes were generated during ceramic coating.

(Comparative Example 2)
In the same manner as in Example 4, except that instead of the laminated film Z, the film for forming the release layer was changed to E5000-25 μm (manufactured by Toyobo), and the winding core was changed from the bakelite core to the ABS core. A release film roll for producing a green sheet was obtained. Although the surface roughness of the original fabric before the mold release processing is rough, by increasing the thickness of the mold release layer, the original fabric protrusions can be filled, and the surface roughness of the mold release layer can be lowered. As a result, the pinhole and thickness variation seen in Comparative Example 1 could be improved. However, since an ABS core having a large outside diameter size change before and after heating was used as the core, a winding deviation occurred when the winding shape 14 days after winding was confirmed.

(Comparative Example 3)
A release film roll for producing a ceramic green sheet was obtained in the same manner as in Example 1 except that the winding core was changed from the bakelite core to the ABS core. Although the winding shape after release processing was good, winding deviation occurred in the core part after 14 days storage.

(Comparative Example 4)
A release film roll for producing a ceramic green sheet was obtained in the same manner as in Example 1 except that the winding core was changed from a bakelite core to a paper core (HC-E, Nippon Paper Tube Industry Co., Ltd.). Although the winding shape after release processing was good, winding deviation occurred in the core part after 14 days storage.

(Comparative Example 5)
A release film roll for producing a ceramic green sheet was obtained in the same manner as in Example 1 except that the winding core was changed from the bakelite core to the PP core (Daika Polymer Co., Ltd.). Winding deviation occurred as the winding shape after mold release processing. Since the outer diameter size variation in the width direction and the circumferential direction is large, it is considered that the variation in stress applied to the film in the width direction is generated, and the winding deviation is generated. Further, after 14 days of storage, the winding deviation at the core portion was further deteriorated.

  The evaluation results of each example and comparative example are shown in Table 1.

In Examples 1 to 4, since the change in the core outer diameter before and after heating and cooling was within a predetermined range, a good winding shape could be maintained without occurrence of winding deviation after the release film roll winding.
In Comparative Examples 1 to 5, since the change in the outer diameter of the core before and after heating and cooling deviated from the predetermined range, the occurrence of winding misalignment in the vicinity of the core was observed after storage over time after winding. In Comparative Example 1, in addition to the occurrence of winding deviation, since the surface roughness of the release surface was large, generation of pinholes in the ceramic sheet was also observed. In Comparative Example 5, generation of winding deviation was observed even immediately after winding. The winding deviation after winding was further deteriorated.

  ADVANTAGE OF THE INVENTION According to this invention, even when the release film was a thin film and the surface was smooth, the provision of the release film roll for green sheet manufacture which does not generate | occur | produce the winding shift | offset | difference during film roll storage was enabled.

Claims (6)

The absolute value of the difference between the core outer diameter at 25 ° C. and the core outer diameter after heating at 50 ° C. for 1 hour is 0.1 mm or less, and the core outer diameter at 25 ° C. and the core outer after cooling at 5 ° C. for 1 hour A release film roll for producing a green sheet, in which a release film is wound on a core having an absolute value of a difference from the diameter of 0.1 mm or less. For the circumferential direction and the width direction of the core, the standard deviation when the core outer diameter at 25 ° C. is measured at 10 points each at different positions is 0.05 mm or less in both the circumferential direction and the width direction of the core. A release film roll for producing a green sheet according to claim 1. The film substrate constituting the release film is a polyester film, and the release film has a release layer on at least one side of the polyester film, and the surface average roughness (Sa) of the release layer surface is 7 nm. The release film roll for producing a ceramic green sheet according to claim 1 or 2, wherein: The polyester film has a surface layer A substantially free of inorganic particles and an opposite surface layer B containing particles, and a release layer is provided on the surface layer A, and the surface layer B The release film roll for producing a ceramic green sheet according to claim 3, wherein the particles contained are silica particles and / or calcium carbonate particles, and the total of the particles is contained in the surface layer B at 5000 to 15000 ppm. 5. A method for producing a ceramic green sheet having a thickness of 0.2 μm to 1.0 μm, wherein the release film is wound around a release film roll for producing a ceramic green sheet according to claim 1. A method for producing a ceramic green sheet. 6. A method for producing a ceramic capacitor, wherein the method for producing a ceramic green sheet according to claim 5 is adopted.