Release film for producing ceramic green sheet

Abstract

To provide a release film that is for producing a ceramic green sheet and that comprises a substrate and a release agent layer, where the film facilitates release of the green sheet and effectively inhibits contamination of the green sheet.SOLUTION: The release film for producing a ceramic green sheet comprises: a substrate; and a release agent layer provided on at least one side of the substrate. The polar component (γsp) of the surface free energy in the surface on the side of the release agent layer opposite to the substrate is at least 0.3 (mN / m).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a release film for producing a ceramic green sheet, and more specifically, to a release film for producing a ceramic green sheet, which allows easy peeling of the green sheet while effectively suppressing contamination of the green sheet, and is particularly suitable for use in the production of ceramic products that require high positional accuracy in the production of multilayer ceramic capacitors, multilayer ceramic substrates, and the like. [Background technology]

[0002] In the manufacture of sheet-like ceramic members, a release film for producing a ceramic green sheet has been used. For example, in order to manufacture a multilayer ceramic product such as a multilayer ceramic capacitor or a multilayer ceramic substrate, a ceramic green sheet is formed on a release film for producing a ceramic green sheet, and a plurality of the obtained ceramic green sheets are stacked and fired. In recent years, with the miniaturization and high performance of electronic devices, multilayer ceramic capacitors and multilayer ceramic substrates have become smaller and more multilayered. To achieve multilayering, ceramic green sheets are required to be thinner, and from the viewpoint of preventing defects such as pinholes and uneven thickness in thin ceramic green sheets and effectively suppressing breakage when thin ceramic green sheets are peeled off from a release film, a release film for producing ceramic green sheets has been proposed, which has a substrate and a release agent layer of a specific component, and in which the arithmetic mean roughness (Ra) and maximum projection height (Rp) on the surface of the release agent layer opposite the substrate are each equal to or less than a predetermined value, and the arithmetic mean roughness (Ra) and maximum projection height (Rp) on the surface of the substrate opposite the release agent layer are each within a predetermined numerical range (see, for example, Patent Document 1).

[0003] In order to miniaturize and multilayer laminated ceramic capacitors and multilayer ceramic substrates, extremely high positional accuracy is required during lamination, but contaminants from the release agent layer of the release film for producing ceramic green sheets can cause misalignment and reduce the positional accuracy, and a solution is required. Such contaminants are presumed to be unreacted silicone components remaining in the release agent layer, but simply reducing the amount of silicone components used in producing the release agent layer reduces the releasability of the green sheet, making it difficult to simultaneously reduce the migration of contaminants to the green sheet and ensure easy releasability of the green sheet. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2013 / 145865 A1 Brochure Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above technical background, the present invention aims to provide a release film for producing a ceramic green sheet, which has a base material and a release agent layer, and which allows easy peeling of the green sheet while effectively suppressing contamination of the green sheet. [Means for solving the problem]

[0006] As a result of intensive research, the present inventors have found that in a release film for producing a ceramic green sheet having a substrate and a release agent layer provided on at least one side of the substrate, the polar component (γ sp The inventors have discovered that by setting the above-mentioned value or more to a predetermined value, it is possible to achieve a balance between the reduction in migration of contaminants into the green sheet and the ease of peeling the green sheet at a high level that exceeds the limits of conventional technology, and have thus completed the present invention. That is, the present invention provides: [1] A release film for producing a ceramic green sheet, comprising a substrate and a release agent layer provided on at least one side of the substrate, The polar component of the surface free energy of the surface of the release agent layer opposite to the substrate (γ sp ) is 0.3 (mN / m) or more.

[0007] Below, [2] to

[12] are each a preferred aspect or embodiment of the present invention. [2] The polar component of the surface free energy of the release agent layer on the side opposite to the substrate (γ sp ) is 0.3 to 1.0 (mN / m). [3] The polar component of the surface free energy of the release agent layer on the side opposite to the substrate (γ sp ) is 0.3 to 0.8 (mN / m). [4] The dispersion component of the surface free energy of the surface of the release agent layer opposite to the substrate (γ sd ) is 22 (mN / m) or more. [5] The release film for producing a ceramic green sheet according to any one of [1] to [4], characterized in that the release agent layer contains a cured product of a curable composition, the curable composition contains at least one reactive compound (a) having at least one reactive functional group selected from the group consisting of a (meth)acryloyl group, a hydroxyl group, and an epoxy group, and the total amount of the reactive compound (a) is 50% or more by mass of the release agent layer. [6] The release film for producing a ceramic green sheet according to [5], wherein the curable composition contains, as the reactive compound (a), at least one reactive silicone (a1) having at least one reactive functional group selected from the group consisting of a (meth)acryloyl group, a hydroxyl group, and an epoxy group, and a siloxane skeleton, and at least one reactive compound (a2) having the same reactive functional group as the reactive silicone (a1) and having a reactive functional group equivalent of 1000 g / mol or less. [7] The curable composition according to [6], further comprising a film-forming compound (a3) ​​having two or more (meth)acryloyl groups in one molecule. [8] The release film for producing a ceramic green sheet according to any one of [1] to [7], wherein the arithmetic mean roughness (Ra) of the surface of the base material on the release agent layer side is 1 to 70 nm. [9] The release film for producing a ceramic green sheet according to any one of [1] to [8], which is used in producing a multilayer ceramic capacitor or a multilayer ceramic substrate.

[10] a) applying a ceramic slurry onto a release film for producing a ceramic green sheet according to any one of [1] to [8]; b) forming a ceramic green sheet from the ceramic slurry applied in the a) step; and c) peeling the ceramic green sheet formed in the b) step from the release film for producing the ceramic green sheet; The method for producing a ceramic green sheet comprising the steps of:

[11] A method for producing a ceramic product, comprising the step of producing a ceramic green sheet by the method for producing a ceramic green sheet according to

[10] .

[12] The method for producing a ceramic product according to

[11] , wherein the ceramic product is a multilayer ceramic capacitor or a multilayer ceramic substrate. Effect of the Invention

[0008] The release film for producing a ceramic green sheet of the present invention realizes technical effects having high practical value at a high level that exceeds the limits of conventional technology, such as easy peeling of a ceramic green sheet formed thereon and effectively suppressing contamination of the ceramic green sheet, and can be suitably used in the production of various ceramic products. For example, it is particularly suitable for use in the production of ceramic products such as multilayer ceramic capacitors and multilayer ceramic substrates, which are composed of thin ceramic layers and require high positional accuracy in production. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing one embodiment of a release film for producing a ceramic green sheet. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention provides a release film for producing a ceramic green sheet, comprising a base material and a release agent layer provided on at least one side of the base material, The polar component of the surface free energy of the surface of the release agent layer opposite to the substrate (γ sp ) is 0.3 (mN / m) or more. That is, the release film for producing a ceramic green sheet of the present invention has a substrate and a release agent layer. The release film for producing a ceramic green sheet of the present invention only needs to have a substrate and a release agent layer, and may or may not have other layers. Therefore, the release film for producing a ceramic green sheet of the present invention may be composed of only a substrate and a release agent layer, or may have other layers such as an antistatic layer in addition to the substrate and the release agent layer. Each of the above layers will now be described.

[0011] Base material The substrate constituting the release film for producing ceramic green sheets of the present invention is not particularly limited, and any substrate may be appropriately selected from those conventionally known as substrates in the technical field. Examples of such substrates include films made of plastics such as polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins such as polypropylene and polymethylpentene, polycarbonate, and ethylene-vinyl acetate copolymers, and may be a single layer or a multilayer of two or more layers of the same or different types. Among these, polyester films are preferred, polyethylene terephthalate films are particularly preferred, and biaxially stretched polyethylene terephthalate films are even more preferred. Polyethylene terephthalate films are less likely to generate dust during processing, use, etc., and therefore, for example, ceramic slurry coating defects due to dust, etc. can be effectively prevented.

[0012] In addition, this substrate may be subjected to a surface treatment such as an oxidation method or a primer treatment in order to improve adhesion to a release agent layer provided on at least one surface of the substrate. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone treatment, and ultraviolet irradiation treatment. These surface treatment methods are appropriately selected depending on the type of substrate film, but generally, corona discharge treatment is preferably used in terms of effectiveness and operability. There is no particular restriction on the thickness of the substrate, which may be appropriately set based on mechanical strength and ease of handling during production and use, but is usually 10 to 300 μm, preferably 12 to 200 μm, and particularly preferably 15 to 125 μm.

[0013] The arithmetic mean roughness (Ra) of the surface of the substrate on the release agent layer side is preferably from 0.1 to 70 nm, and more preferably from 1 to 60 nm. The arithmetic mean roughness (Ra) of the surface of the substrate on the release agent layer side is preferably 0.1 to 70 nm in terms of handling of the substrate, suppression of poor electrical continuity, etc. In addition, substrates having a surface arithmetic mean roughness (Ra) of 1 to 70 nm are relatively easy and inexpensive to obtain, and are therefore also preferable in terms of availability and production costs of the release film for producing the ceramic green sheet of the present invention.

[0014] The arithmetic mean roughness (Ra) of the surface of the substrate opposite to the release agent layer side is preferably from 5 to 70 nm, and particularly preferably from 10 to 60 nm. When the arithmetic mean roughness (Ra) of the surface of the substrate opposite the release agent layer side is not less than the above-mentioned lower limit, blocking during winding of the release film for producing a ceramic green sheet of the present invention can be effectively suppressed, while when it is not more than the above-mentioned upper limit, it becomes easy to smooth the surface of the release agent layer.

[0015] Release agent layer The material of the release agent layer constituting the release film for producing a ceramic green sheet of the present invention is not particularly limited, and the polar component (γ sp Any material may be used as long as it satisfies the condition that the compressive strength is 0.3 (mN / m) or more. From the viewpoint of ease of production of the release film for producing a ceramic green sheet and appropriate control of the surface free energy and surface roughness, it is preferable to form the release agent layer by applying a curable composition onto a substrate and curing the composition, and it is particularly preferable to form the release agent layer by applying a photocurable and / or thermosetting curable composition and curing the composition. That is, it is preferable that the release agent layer in the present invention contains a cured product of the curable composition.

[0016] curable composition The curable composition preferably used for forming the release agent layer in the present invention preferably contains at least one reactive compound (a) having at least one reactive functional group selected from the group consisting of a (meth)acryloyl group, a hydroxyl group, and an epoxy group. By using a curable composition containing at least one reactive compound (a) having at least one reactive functional group selected from the group consisting of a (meth)acryloyl group, a hydroxyl group, and an epoxy group, the release agent layer of the release film for producing the ceramic green sheet of this embodiment can be easily formed with good controllability of the surface free energy, etc.

[0017] The curable composition may contain only one reactive compound (a) having at least one reactive functional group selected from the group consisting of (meth)acryloyl group, hydroxyl group, and epoxy group, or may contain two or more reactive compounds (a) having at least one reactive functional group selected from the group consisting of (meth)acryloyl group, hydroxyl group, and epoxy group. From the viewpoint of controlling various properties such as curability, releasability, and surface free energy of the release agent layer, it is preferable to use two or more reactive compounds (a) in combination, and it is particularly preferable to use a combination of the reactive silicone (a1) and the crosslinkable compound (a2) described later, and further to combine a film-forming compound (a3).

[0018] The curable composition may be composed of only a reactive compound (a) having at least one reactive functional group selected from the group consisting of a (meth)acryloyl group, a hydroxyl group, and an epoxy group, or may contain other components such as a solvent, a radical initiator, a cationic initiator, a leveling agent, an antistatic agent, a dye, and a pigment. The amount of reactive compound (a) having at least one reactive functional group selected from the group consisting of a (meth)acryloyl group, a hydroxyl group, and an epoxy group used is preferably 50 mass% or more, particularly preferably 60 to 96 mass%, of the mass of the release agent layer.

[0019] Reactive Compound (a) The reactive compound (a) preferably used for forming the release agent layer in the present invention has at least one reactive functional group selected from the group consisting of a (meth)acryloyl group, a hydroxyl group, and an epoxy group. By having at least one reactive functional group selected from the group consisting of a (meth)acryloyl group, a hydroxyl group, and an epoxy group, it is possible to impart photocurability and / or thermosetting property to the curable composition.

[0020] The reactive compound (a) may have one or more reactive functional groups, but from the viewpoint of photocurability and / or thermosetting property, it preferably has two or more reactive functional groups, more preferably has 2 to 15 reactive functional groups, and particularly preferably has 2 to 10 reactive functional groups. When the reactive compound (a) has two or more reactive functional groups, it may have two or more of the same type of reactive functional groups, or may have a combination of two or more different types of reactive functional groups in total. From the viewpoint of curability, etc., when active energy rays are used, it is preferable that the reactive compound (a) has a (meth)acryloyl group. When heat curing is also used, a material containing a hydroxyl group or an epoxy group can be appropriately selected.

[0021] Preferred examples of the reactive compound (a) include reactive silicone (a1) having at least one reactive functional group selected from the group consisting of a (meth)acryloyl group, a hydroxyl group, and an epoxy group, and a siloxane skeleton, reactive compound (a2) having the same reactive functional group as the reactive silicone (a1) and having a reactive functional group equivalent of 1000 g / mol or less, and film-forming compound (a3) ​​having two or more (meth)acryloyl groups in one molecule. In the curable composition, it is preferable to use a combination of the reactive silicone (a1) and the reactive compound (a2), and it is further preferable to use a combination of the film-forming compound (a3).

[0022] Reactive Silicone (a1) The curable composition preferably contains, as the reactive compound (a), at least one reactive functional group selected from the group consisting of a (meth)acryloyl group, a hydroxyl group, and an epoxy group, and a reactive silicone (a1) having a siloxane skeleton. By using the reactive silicone (a1), the surface of the release agent layer is given the desired releasability, making it possible to more easily peel off the ceramic green sheet. The reactive silicone (a1) is not limited as long as it has at least one reactive functional group selected from the group consisting of a (meth)acryloyl group, a hydroxyl group, and an epoxy group, and has a siloxane skeleton. By having at least one reactive functional group selected from the group consisting of (meth)acryloyl group, hydroxyl group, and epoxy group, the reactive functional group reacts by irradiation with active energy rays or by a separate reaction step (for example, a heating step), and the siloxane skeleton is incorporated into a crosslinked structure and fixed. This makes it possible to more effectively prevent the reactive silicone (a1) from contaminating the ceramic green sheet formed on the release agent layer. As the reactive functional group, an epoxy group is particularly preferred.

[0023] The reactive functional group may be introduced into one end of the siloxane skeleton, may be introduced into both ends, or may be introduced into a side chain. At least one reactive functional group selected from the group consisting of (meth)acryloyl group, hydroxyl group, and epoxy group is preferably introduced into one molecule of the reactive silicone (a1). When having two or more reactive functional groups, it may have two or more of the same type of reactive functional groups, or may have a combination of two or more different reactive functional groups in total. In addition to the reactive functional group selected from the group consisting of a (meth)acryloyl group, a hydroxyl group, and an epoxy group, it may further have a vinyl group, a maleimide group, a carboxyl group, an isocyanate group, or the like.

[0024] There are no particular limitations on the molecular weight of the reactive silicone (a1), but from the standpoint of appropriate releasability and stain prevention, it is preferably from 5,000 to 100,000, and particularly preferably from 10,000 to 70,000.

[0025] In the curable composition, the reactive silicone (a1) may be used alone or in combination of two or more kinds. The content of the reactive silicone (a1) in the curable composition is not particularly limited, but is preferably from 0.1 to 20 mass %, and particularly preferably from 0.2 to 15 mass %, based on the total mass of the release agent layer.

[0026] Crosslinking compound (a2) The curable composition preferably contains, as the reactive compound (a), a reactive compound (a2) having the same reactive functional group as the reactive silicone (a1) and having a reactive functional group equivalent of 1000 g / mol or less. It is particularly preferable to use the reactive compound (a2) in combination with the reactive silicone (a1). The reactive compound (a2) functions as a crosslinking agent for the reactive silicone (a1) etc., promotes the effect of the curable composition, and can incorporate and fix the reactive silicone (a1) etc. into a crosslinked structure, thereby making it possible to more effectively suppress contamination of the ceramic green sheet.

[0027] The reactive functional group equivalent of the reactive compound (a2) is 1000 g / mol or less, preferably 500 g / mol or less, particularly preferably 300 g / mol or less. By having a reactive functional group equivalent of 1000 g / mol or less, the polymer has a sufficient number of (meth)acryloyl groups, hydroxyl groups, and / or epoxy groups to achieve suitable crosslinking performance. The reactive compound (a2) preferably has a total of 1 or more reactive functional groups ((meth)acryloyl groups, hydroxyl groups, and / or epoxy groups), preferably 2 to 15, and particularly preferably 2 to 6. When the number of reactive functional groups is within the above range, more appropriate crosslinking performance can be achieved.

[0028] The molecular weight of the crosslinkable compound (a2) is not particularly limited, but from the viewpoint of crosslinking performance, it is preferably from 150 to 3,500, and particularly preferably from 150 to 1,500. The crosslinkable compound (a2) may have a siloxane skeleton. In this case, by introducing a sufficient amount of siloxane skeleton into the release agent layer together with the siloxane skeleton of the reactive silicone (a1), more preferable release performance can be achieved.

[0029] In the curable composition, the crosslinkable compound (a2) may be used alone or in combination of two or more kinds. The content of the crosslinkable compound (a2) in the curable composition is not particularly limited, but is preferably 0.08 to 99 mass%, particularly preferably 0.4 to 50 mass%, based on the total mass of the release agent layer. Also, based on the amount of reactive silicone (a1) used, it is preferably 81 to 9900 mass parts, particularly preferably 85 to 1000 mass parts, based on 100 mass parts of reactive silicone (a1).

[0030] It is also preferable to use a compound having excellent film-forming properties as the reactive compound (a) in the curable composition. The compound having excellent film-forming properties may be either a compound having a (meth)acryloyl group or a compound having a hydroxyl group, but it is preferable to use a film-forming compound (a3) ​​having two or more (meth)acryloyl groups in one molecule. Film-forming compound (a3) The curable composition preferably contains, as the reactive compound (a), a film-forming compound (a3) ​​having two or more (meth)acryloyl groups in one molecule. By including the film-forming compound (a3) ​​having two or more (meth)acryloyl groups in one molecule, the curable composition can be cured by irradiation with active energy rays. The film-forming compound (a3) ​​may be any one of a monomer, an oligomer, or a polymer, or may be a mixture thereof. The film-forming compound (a3) ​​is preferably a (meth)acrylic acid ester. Here, the (meth)acrylic acid ester means both an acrylic acid ester and a methacrylic acid ester. The same applies to other similar terms.

[0031] The (meth)acrylic acid ester is preferably at least one selected from polyfunctional (meth)acrylate monomers and (meth)acrylate oligomers, particularly preferably at least one selected from difunctional or higher (meth)acrylate monomers and (meth)acrylate oligomers, and more preferably a trifunctional or higher (meth)acrylate monomer. By being difunctional or higher, more preferably trifunctional or higher, the curability of the curable composition is excellent, and the surface of the obtained release agent layer also has excellent releasability.

[0032] Examples of polyfunctional (meth)acrylate monomers include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, neopentyl glycol adipate di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified phosphoric acid di(meth)acrylate, allylated cyclohexyl di(meth)acrylate, and isocyanurate di(meth)acrylate. acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, propionic acid modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide modified trimethylolpropane tri(meth)acrylate, tris((meth)acryloxyethyl)isocyanurate, propionic acid modified dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, caprolactone modified dipentaerythritol hexa(meth)acrylate, and the like. These may be used alone or in combination of two or more.

[0033] Examples of the polyfunctional (meth)acrylate oligomer include polyester acrylate oligomers, epoxy acrylate oligomers, urethane acrylate oligomers, polyether acrylate oligomers, polybutadiene acrylate oligomers, and silicone acrylate oligomers.

[0034] The polyester acrylate oligomer can be obtained, for example, by esterifying the hydroxyl groups of a polyester oligomer having hydroxyl groups at both ends, which is obtained by condensation of a polycarboxylic acid and a polyhydric alcohol, with (meth)acrylic acid, or by esterifying the terminal hydroxyl groups of an oligomer obtained by adding an alkylene oxide to a polycarboxylic acid, with (meth)acrylic acid.

[0035] The epoxy acrylate oligomer can be obtained, for example, by reacting (meth)acrylic acid with the oxirane ring of a relatively low molecular weight bisphenol epoxy resin or novolac epoxy resin to esterify it. In addition, a carboxyl-modified epoxy acrylate oligomer obtained by partially modifying an epoxy acrylate oligomer with a dibasic carboxylic acid anhydride can also be used.

[0036] The urethane acrylate oligomer can be obtained, for example, by esterifying a polyurethane oligomer obtained by reacting a polyether polyol or polyester polyol with a polyisocyanate with (meth)acrylic acid.

[0037] The polyether acrylate oligomer can be obtained by esterifying the hydroxyl groups of a polyether polyol with (meth)acrylic acid.

[0038] In the curable composition, the film-forming compound (a3) ​​may be used alone or in combination of two or more kinds. The content of the film-forming compound (a3) ​​in the curable composition is not particularly limited, but is preferably 50 to 90 mass %, and particularly preferably 60 to 85 mass %, based on the total mass of the release agent layer.

[0039] The release agent layer can be formed by applying the raw material of the release agent layer, preferably the above-mentioned curable composition, to at least one surface of the substrate, and then drying as necessary and curing by irradiation with active energy rays such as light. If the reactive functional group of the reactive compound (a) is one that reacts with heat, the reaction can be caused by drying at this time, and the reactive compound (a) preferably having a siloxane skeleton can be incorporated into a crosslinked structure. There is no particular limit to the method of applying the curable composition, and for example, gravure coating, bar coating, spray coating, spin coating, knife coating, roll coating, die coating, etc. can be used.

[0040] As the active energy ray, ultraviolet rays, electron beams, etc. are usually used. The irradiation amount of the active energy ray varies depending on the type of energy ray. For example, in the case of ultraviolet rays, the light amount is 10 to 1000 mJ / cm. 2 is preferable, and particularly 20 to 500 mJ / cm 2 In the case of electron beams, the dose is preferably about 0.1 to 50 kGy.

[0041] The polar component (γ sp ) is 0.3 (mN / m) or more. The polar component of the surface free energy of the release agent layer on the side opposite the substrate (γ sp ) is 0.3 (mN / m) or more, which, in combination with other technical features of the present invention, makes it possible for the release film for producing a ceramic green sheet of the present invention to achieve excellent technical effects of great practical value, such as a high level of compatibility between ease of peeling of the ceramic green sheet formed thereon and inhibition of contamination of the ceramic green sheet. The polar component of the surface free energy of the release agent layer on the side opposite the substrate (γ spThe mechanism by which a release coefficient of 0.3 (mN / m) or more can achieve both ease of peeling of the ceramic green sheet and suppression of contamination of the ceramic green sheet is not necessarily clear; however, since the surface free energy of the release agent layer can be closely related to the releasability and contamination of the ceramic green sheet and other adherends, it is presumed that there is an optimal value of surface free energy that can achieve both releasability and contamination resistance.

[0042] The polar component of the surface free energy of the release agent layer on the side opposite the substrate (γ sp ) can be measured by a method conventionally known in the art, for example, by a contact angle method. For example, the contact angles measured for multiple types of liquids can be analyzed by applying the Kitazaki-Hata and extended Foulkes equations (Kitazaki-Hata equations) to obtain the polar component (γ sp More specifically, it can be measured by the method described in the examples of the present specification.

[0043] The polar component of the surface free energy of the release agent layer on the side opposite the substrate (γ sp ) is preferably from 0.3 to 1.0 (mN / m), and particularly preferably from 0.3 to 0.8 (mN / m). The polar component of the surface free energy of the release agent layer on the side opposite the substrate (γ sp ) can be appropriately adjusted by adjusting the type and amount of the material constituting the release agent layer and the coating amount of the release agent layer. In particular, it can be appropriately adjusted by adjusting the reactive functional group equivalent and the amount used of the reactive compound (a) having at least one reactive functional group selected from the group consisting of a (meth)acryloyl group, a hydroxyl group, and an epoxy group, particularly the reactive compound (a2) having the same reactive functional group as the reactive silicone (a1) and having a reactive functional group equivalent of 1000 g / mol or less.

[0044] The release film for producing a ceramic green sheet of the present invention has a polar component (γ sp) satisfies the above condition, and no other restrictions are imposed. However, the dispersion component (γ sd ) is preferably 22 (mN / m) or more. The dispersion component of the surface free energy of the release agent layer on the side opposite the substrate (γ sd ) is 22 (mN / m) or more, which, in combination with other technical features of the present invention, makes it possible for the release film for producing a ceramic green sheet of this embodiment to achieve an excellent technical effect of even greater practical value, such as an even higher level of compatibility between ease of peeling of the ceramic green sheet formed thereon and suppression of contamination of the ceramic green sheet. The dispersion component of the surface free energy of the release agent layer on the side opposite the substrate (γ sd The mechanism by which a release coefficient of 22 (mN / m) or more can achieve both ease of peeling of the ceramic green sheet and inhibition of contamination of the ceramic green sheet at a higher level is not necessarily clear; however, since the surface free energy of the release agent layer can be closely related to the releasability and contamination of the ceramic green sheet and other adherends, it is presumed that there is an optimal value of surface free energy that can achieve both releasability and contamination resistance.

[0045] The dispersion component of the surface free energy of the release agent layer on the side opposite the substrate (γ sd ) can be measured by a method conventionally known in the art, for example, by a contact angle method. For example, the contact angles measured for multiple types of liquids can be analyzed by applying the Kitazaki-Hata and extended Foulkes equations (Kitazaki-Hata equations) to obtain the dispersion component (γ sd More specifically, it can be measured by the method described in the examples of the present specification.

[0046] The dispersion component of the surface free energy of the release agent layer on the side opposite the substrate (γ sd ) is preferably 22 (mN / m) or more and 30 (mN / m) or less, and particularly preferably 22 to 28 (mN / m). The dispersion component of the surface free energy of the release agent layer on the side opposite the substrate (γ sd ) can be appropriately adjusted by adjusting the type and amount of the material constituting the release agent layer and the coating amount of the release agent layer. In particular, it can be appropriately adjusted by adjusting the reactive functional group equivalent and the amount used of the reactive compound (a) having at least one reactive functional group selected from the group consisting of a (meth)acryloyl group, a hydroxyl group, and an epoxy group, particularly the reactive compound (a2) having the same reactive functional group as the reactive silicone (a1) and having a reactive functional group equivalent of 1000 g / mol or less.

[0047] The thickness of the release agent layer is preferably 0.05 to 2 μm, and particularly preferably 0.2 to 1.5 μm. A thickness of 0.05 μm or more is preferable from the viewpoint of smoothness of the surface of the release agent layer and suppression of pinholes and thickness unevenness of the ceramic green sheet. A thickness of 2 μm or less is preferable from the viewpoint of suppression of curling due to cure shrinkage of the release agent layer. It is also preferable from the viewpoint of suppression of blocking and charging.

[0048] Other layers The release film for producing a ceramic green sheet of the present invention may have layers other than the above-mentioned substrate and release agent layer, such as a protective layer, an adhesive layer, an antistatic layer, etc. The substrate and the release agent layer may be laminated directly to each other, or may be laminated via another layer such as an adhesive layer.

[0049] Release film for ceramic green sheet manufacturing The release film for producing a ceramic green sheet of the present invention allows easy release of the ceramic green sheet formed thereon and can effectively suppress contamination of the ceramic green sheet, and therefore can be suitably used in the production of ceramic green sheets used in various ceramic products, such as multilayer ceramic capacitors or multilayer ceramic substrates.

[0050] There is no particular limitation on the method for producing a ceramic green sheet using the release film for producing a ceramic green sheet of the present invention. For example, the release film for producing a ceramic green sheet of the present invention can be preferably used in a production method having the following steps. a) A step of applying a ceramic slurry onto the release film for producing a ceramic green sheet of the present invention. b) forming a ceramic green sheet from the ceramic slurry applied in the a) step; c) peeling the ceramic green sheet formed in the b) step from the release film for producing the ceramic green sheet.

[0051] By firing the ceramic green sheet obtained by the above-mentioned production method, various ceramic products can be produced. In manufacturing a multilayer ceramic capacitor, a step of printing internal electrodes on the green sheet is provided between the above steps b) and c), followed by step c) (peeling), lamination and pressure bonding, cutting and separation, firing, and external electrode formation steps to manufacture the multilayer ceramic capacitor. EXAMPLES

[0052] The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto. It is not something that is done.

[0053] In the following Examples and Comparative Examples, the physical properties and characteristics were evaluated by the following methods. (Surface Free Energy) The contact angle of water on the surface of the release agent layer was measured under the following conditions. Contact angle meter: Kyowa Interface Science Co., Ltd. DM-701 Fully automatic contact angle meter Contact angle meter analysis software: FAMAS made by the same company The contact angle θ was calculated by the sessile drop method according to the following procedure. i) The sample cut into a rectangular shape was set in the contact angle meter. ii) Approximately 6.1 μL of water droplets were ejected from the syringe pump. iii) Images of the droplets ejected onto the sample were taken. iv) The angle between the sample and the droplet was measured and this was taken as the contact angle (°) of water. In the same manner, the contact angles of diiodomethane and 1-bromonaphthalene were also measured. (Diiodomethane: 2.1 μL, 1-bromonaphthalene: 3.4 μL) Using the above contact angle meter analysis software, the surface free energy was calculated from each contact angle obtained. The Kitazaki-Hata and extended Foulkes equation (Kitazaki-Hata equation) was used to calculate the surface free energy of the solid (sample), by inputting the contact angle (θ) measured with the above three types of liquid and the known surface free energy of each liquid into the equation below, and solving the resulting three-dimensional linear equation to obtain the surface free energy of the solid (sample). JPEG2024079568000002.jpg1151 obtained.

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[0054] (Backside contamination) Using Terani Chemical Industry's oil-based marker ink (large, red, writing line width: 5 x 8 mm), a line 8 mm wide x 70 mm long was drawn on the side opposite the release agent layer of the substrate, and after 1 minute, a central 50 mm long section was observed for the line width and evaluated according to the following criteria. 5: Remaining line width is 90% or more 4: There are areas where the remaining line width is between 70% and 90%. 3: There are areas where the remaining line width is between 50% and 70%. 2: There are areas where the remaining line width is 20% or more but less than 50%. 1: There are areas where the remaining line width is between 0% and 20%. (Tape peeling force) The release sample was placed on a horizontal table with the release agent layer facing up, and adhesive tape "Polyester Adhesive Tape No. 31B75 High" (brand name, manufactured by Nitto Denko Corporation) was attached to the release agent layer side and cut to a size of 200 mm x 50 mm. Further, 20 g / cm was applied to the top of the adhesive tape. 2 A load was placed so that the specimen was aged at 70° C. for 20 hours. Thereafter, 180° peeling was performed at a tensile speed of 300 mm / min using a tensile tester, and the peel force was calculated by dividing the average peel load in the region where peeling became stable by the width of the adhesive tape.

[0055] Details of each of the constituent components such as resins used in the release agent layer in the examples and comparative examples are as follows. (a3) Multifunctional acrylate 1 Product name: NK Ester A9300, manufactured by Shin-Nakamura Chemical Co., Ltd. Trifunctional isocyanuric acrylate monomer (tris-(2-acryloxyethyl) isocyanurate) (a1) Epoxy-modified silicone 1 Arakawa Chemical Industries, Ltd., Product name: Silicolyse UV POLY201 Dimethyl silicone, alicyclic epoxy silicone block copolymer (a2) Epoxy-modified silicone 2 Manufactured by Shin-Etsu Chemical Co., Ltd., Product name: Shin-Etsu Silicone KR-470 Alicyclic epoxy group-containing cyclic siloxane tetrafunctional oligomer Epoxy equivalent: 200g / mol (a2) Epoxy-modified silicone 3 Manufactured by Shin-Etsu Chemical Co., Ltd., Product name: Shin-Etsu Silicone X-22-169AS Both ends / alicyclic epoxy modified silicone oil Epoxy equivalent: 500g / mol (a2) Epoxy-modified silicone 4 Manufactured by Shin-Etsu Chemical Co., Ltd., Product name: Shin-Etsu Silicone X-22-169B Both ends / alicyclic epoxy modified silicone oil Epoxy equivalent: 1700g / mol (a2) Epoxy-modified silicone 5 Manufactured by Shin-Etsu Chemical Co., Ltd., Product name: Shin-Etsu Silicone KF-102 Side chain type / alicyclic epoxy modified silicone oil Epoxy equivalent: 3600g / mol Cationic initiator 1 Sanshin Chemical Industry Co., Ltd. Product name: San-Aid SI-100 Radical initiator 1 Made by IGM RESINS Product name: Esacure ONE α-Hydroxyketone type photoinitiator

[0056] [Example 1] Multifunctional acrylate 1, epoxy modified silicone 1, epoxy modified silicone 2, cationic initiator 1, and radical initiator 1 were mixed in the mass ratio shown in Table 1 to prepare a curable composition for the release agent layer. A polyethylene terephthalate film having a thickness of about 30 μm and a surface arithmetic mean roughness (Ra) of about 20 nm was used as the substrate. The curable composition prepared above was applied to one surface of the substrate, and after drying at 100°C for 15 seconds, ultraviolet light was irradiated using a high-pressure mercury lamp (accumulated light amount: about 40 mJ / cm 2 ) and curing to form a release agent layer, thereby producing a release film having a substrate and a release agent layer provided on one side of the substrate. The surface free energy, backside contamination, and tape peeling force of the release film produced above were evaluated by the methods described above. The results are shown in Table 1.

[0057] [Examples 2 to 4 and Comparative Examples 1 to 2] A release film was produced in the same manner as in Example 1, except that the formulation of the curing agent composition for the release agent layer was changed to that shown in Table 1, and then evaluated. The results are shown in Table 1.

[0058] [Table 1] [Industrial Applicability]

[0059] The release film for producing ceramic green sheets of the present invention allows easy release of the ceramic green sheets formed thereon, while at the same time effectively suppressing contamination of the ceramic green sheets, thereby simultaneously achieving technical effects of high practical value at a high level that surpasses the limitations of conventional technology. Since the film can be suitably used in the production of various ceramic products, it has high applicability in various fields of industry, including the electrical and electronics industry, electronic parts industry, machinery industry, and automotive industry. [Explanation of symbols]

[0060] 11: Release film for ceramic green sheet manufacturing 12: Release agent layer 13: Base material

Claims

1. A release film for manufacturing a ceramic green sheet, comprising a base material and a release agent layer provided on at least one of the base materials, The polar component (γ ｓｐ ) of the surface free energy of the surface on the side opposite to the base material of the release agent layer is 0.3 (mN / m) or more, and the release film for manufacturing the ceramic green sheet is as described above.

2. The polar component (γ ｓｐ ) of the surface free energy of the surface of the release agent layer on the side opposite to the base material is 0.3 to 1.0 (mN / m), and the release film for manufacturing a ceramic green sheet according to claim 1.

3. The polar component (γ ｓｐ ) of the surface free energy of the surface on the side opposite to the base material of the release agent layer is 0.3 to 0.8 (mN / m), and the release film for manufacturing a ceramic green sheet according to claim 1.

4. The dispersive component (γ ｓｄ ) of the surface free energy of the surface of the release agent layer on the side opposite to the base material is 22 (mN / m) or more. The release film for manufacturing a ceramic green sheet according to any one of claims 1 to 3.

5. The release agent layer contains a cured product of a curable composition, and the curable composition contains at least one reactive compound (a) selected from the group consisting of at least one reactive functional group selected from the group consisting of (meth)acryloyl group, hydroxyl group, and epoxy group, and the total amount of the reactive compound (a) is 50% or more of the release agent layer by mass ratio. The release film for manufacturing a ceramic green sheet according to any one of Claims 1 to 3.

6. The curable composition contains, as the reactive compound (a), at least one reactive silicone (a1) having at least one reactive functional group selected from the group consisting of (meth)acryloyl group, hydroxyl group, and epoxy group, and a siloxane skeleton, and at least one reactive compound (a2) having the same reactive functional group as the reactive silicone (a1) and a reactive functional group equivalent of 1000 g / mol or less, and a film-forming compound (a3) having two or more (meth)acryloyl groups in one molecule. The curable composition according to Claim 5.

7. The arithmetic mean roughness (Ra) of the surface of the base material on the release agent layer side is 1 to 70 nm. The release film for manufacturing a ceramic green sheet according to any one of Claims 1 to 3.

8. The release film for manufacturing a ceramic green sheet according to any one of Claims 1 to 3, which is used for manufacturing a multilayer ceramic capacitor or a multilayer ceramic substrate.

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