JP6285777B2 - Release film for ceramic green sheet manufacturing process - Google Patents

Description

  The present invention relates to a release film used in a process for producing a ceramic green sheet.

  Conventionally, 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, and a plurality of obtained ceramic green sheets are stacked and fired.

  The ceramic green sheet is formed into a uniform thickness by coating a ceramic slurry containing a ceramic material such as barium titanate or titanium oxide on a release film. As the release film, a film base is usually used which is subjected to a release treatment with a silicone compound such as polysiloxane to form a release agent layer.

  In recent years, along with miniaturization and high performance of electronic devices, the miniaturization and multilayering of multilayer ceramic capacitors and multilayer ceramic substrates have progressed, and thinning of ceramic green sheets has progressed. When the thickness of the ceramic green sheet is reduced to 3 μm or less, for example, when the ceramic slurry is applied and dried, the ceramic green sheet is caused by the surface state of the release agent layer in the release film. Defects such as pinholes and uneven thickness are likely to occur. Further, when the formed ceramic green sheet is peeled from the release film, problems such as breakage due to a decrease in strength of the ceramic green sheet are likely to occur.

  Therefore, the peelable film is required to have a peelability capable of peeling a thin ceramic green sheet formed on the peelable film without breaking the peelable film.

  By the way, the release film used for the ceramic green sheet as described above is generally stored and transported in a rolled state, and is unwound when the ceramic slurry is applied. When the release film is unwound, it is easy to be charged with static electricity. In order to solve this problem, Patent Document 1 proposes to use a release film having a rough arithmetic average roughness on the surface (back surface) opposite to the surface on which the release agent layer of the substrate is provided. Has been.

JP 2003-203822 A

  However, when the release film described in Patent Document 1 is used, when the release film formed with the ceramic green sheet is wound and stored, the rough surface shape on the back surface of the release film is transferred to the ceramic green sheet. In some cases, defects such as partial thinning of the ceramic green sheet occur, and when a ceramic green sheet is laminated to produce a capacitor, a defect due to a short circuit may occur.

  On the other hand, if the arithmetic surface roughness of the back surface of the release film is small, the surface state becomes flat, and slipping between the release films that have been wound up overlaps with each other. Etc. will be caused.

  Further, the ceramic grease sheet is punched into a predetermined size together with the release film, and is peeled off from the release film and laminated. At that time, if the transfer of a peeling imparting component (for example, a silicone compound) occurs on the surface of the ceramic green sheet that is in contact with the release agent layer, the adhesion between the ceramic green sheets is reduced, resulting in a decrease in yield. Cause problems. For this reason, there is a demand for a release film with little transfer of the release imparting component to the ceramic green sheet.

  The present invention has been made in view of such a situation, and is excellent in the peelability of the ceramic green sheet, the peeling imparting component is not easily transferred to the ceramic green sheet, and a defect occurs in the ceramic green sheet. It is another object of the present invention to provide a release film for a ceramic green sheet manufacturing process in which blocking can be prevented and suppressed, and blocking is unlikely to occur.

  In order to achieve the above object, first, the present invention provides a ceramic comprising a substrate having a first surface and a second surface, and a release agent layer provided on the first surface of the substrate. A release film for a green sheet manufacturing process, wherein the release agent layer is formed from a release agent composition containing an active energy ray-curable component (A) and a photopolymerization initiator (B), and the active energy ray cure The component (A) is an hydroxyl group-containing (meth) acrylate (a1) having at least three (meth) acryloyl groups on average in one molecule, a polyvalent isocyanate compound (a2), and at least in one molecule. A linear dimethylorganopolysiloxane (a3) having one hydroxyl group and a weight average molecular weight of 500 to 8000, the (meth) acrylate (a1) and the polyvalent isocyanate compound (a2) And the amount of the dimethylorganopolysiloxane (a3) with respect to the total amount of the dimethylorganopolysiloxane (a3) is reacted so that the mass ratio is 0.01 to 0.10, and the thickness of the release agent layer Is 0.3 to 2 μm, the arithmetic average roughness (Ra1) on the surface of the release agent layer opposite to the base material is 8 nm or less, and the maximum protrusion height (Rp1) is 50 nm or less. Peeling for a ceramic green sheet manufacturing process, wherein the arithmetic mean roughness (Ra2) on the second surface of the substrate is 5 to 40 nm and the maximum protrusion height (Rp2) is 60 to 500 nm A film is provided (Invention 1).

  According to the release film for a ceramic green sheet production process according to the invention (Invention 1), the release agent layer is composed of the release agent composition, so that the ceramic green sheet is excellent in peelability and the ceramic green sheet The peeling imparting component is difficult to migrate. In addition, by defining the thickness of the release agent layer and the surface state of the release agent layer and the substrate as described above, it is possible to prevent and suppress the occurrence of defects in the ceramic green sheet. Blocking is unlikely to occur.

  In the said invention (invention 1), it is preferable that the said photoinitiator (B) is an alpha-hydroxy ketone type compound or an alpha-aminoalkyl phenone type compound (invention 2).

  In the said invention (invention 1 and 2), after forming a polyvinyl butyral resin layer in the surface on the opposite side to the said base material of the said releasing agent layer, when peeling the said polyvinyl butyral resin layer from the said releasing agent layer The silicon atomic ratio measured by photoelectron spectroscopic analysis of the surface of the polyvinyl butyral resin layer that is in contact with the release agent layer is preferably less than 1.0 atomic% (Invention 3).

  According to the release film for a ceramic green sheet manufacturing process according to the present invention, it is excellent in the peelability of the ceramic green sheet, the peeling imparting component is not easily transferred to the ceramic green sheet, and a defect occurs in the ceramic green sheet. It can be prevented / suppressed, and blocking is less likely to occur.

It is sectional drawing of the peeling film for ceramic green sheet manufacturing processes which concerns on one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.
[Peeling film for ceramic green sheet manufacturing process]
As shown in FIG. 1, a release film 1 for a ceramic green sheet manufacturing process according to the present embodiment (hereinafter sometimes simply referred to as “release film 1”) includes a base material 11 and a first of the base material 11. And a release agent layer 12 laminated on the surface 111 (upper surface in FIG. 1). The base material 11 includes a second surface 112 on the surface (the lower surface in FIG. 1) opposite to the first surface 111 of the base material 11.

1. Base Material The base material 11 of the release film 1 according to the present embodiment is not particularly limited as long as the release agent layer 12 can be laminated. Examples of the substrate 11 include films made of polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins such as polypropylene and polymethylpentene, plastics such as polycarbonate and polyvinyl acetate, and may be a single layer. However, it may be a multilayer of two or more layers of the same type or different types. Among these, a polyester film is preferable, a polyethylene terephthalate film is particularly preferable, and a biaxially stretched polyethylene terephthalate film is more preferable. Since the polyethylene terephthalate film hardly generates dust or the like during processing or use, for example, it is possible to effectively prevent a ceramic slurry coating failure due to dust or the like. Furthermore, the effect which prevents a coating defect etc. can be heightened by performing an antistatic process to a polyethylene terephthalate film.

  Moreover, in this base material 11, for the purpose of improving the adhesiveness with the release agent layer 12, an oxidation method or unevenness is formed on the first surface 111 or both the first surface 111 and the second surface 112 as desired. Surface treatment by a chemical method or the like, or primer treatment can be performed. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone, ultraviolet irradiation treatment, and the like. Examples include a thermal spraying method. These surface treatment methods are appropriately selected depending on the type of the base film, but generally, a corona discharge treatment method is preferably used from the viewpoints of effects and operability.

  The thickness of the base material 11 should just be 10-300 micrometers normally, Preferably it is 15-200 micrometers, Especially preferably, it is 20-125 micrometers.

  The arithmetic average roughness (Ra0) on the first surface 111 of the substrate 11 is preferably 2 to 50 nm, and particularly preferably 5 to 30 nm. Further, the maximum protrusion height (Rp0) on the first surface 111 of the substrate 11 is preferably 10 to 700 nm, and particularly preferably 30 to 500 nm. By setting the arithmetic average roughness (Ra0) and the maximum protrusion height (Rp0) on the first surface 111 of the base material 11 within the above ranges, the surface 121 of the release agent layer 12 (the side opposite to the base material 11) It is easy to keep the arithmetic average roughness (Ra1) and the maximum protrusion height (Rp1) in the ranges described later.

  The arithmetic mean roughness (Ra2) on the second surface 112 of the substrate 11 is 5 to 40 nm, preferably 10 to 30 nm, and particularly preferably 15 to 25 nm. The maximum protrusion height (Rp2) on the second surface 112 of the substrate 11 is 60 to 500 nm, and preferably 100 to 400 nm. By setting the arithmetic average roughness (Ra2) and the maximum protrusion height (Rp2) on the second surface 112 of the base material 11 within the above ranges, the ceramic green originates from the second surface 112 of the base material 11 The occurrence of defects in the sheet can be prevented / suppressed, and the occurrence of blocking can be suppressed.

  That is, when the arithmetic average roughness (Ra2) of the second surface 112 of the substrate 11 is less than 5 nm, the second surface 112 is too smooth, and the second surface 112 of the substrate 11 is wound when the release film 1 is wound. The second surface 112 and the highly smooth release agent layer 12 are in close contact with each other, and blocking is likely to occur. On the other hand, when the arithmetic average roughness (Ra2) of the second surface 112 of the base material 11 exceeds 40 nm, the maximum protrusion height (Rp2) of the second surface 112 of the base material 11 is kept within the preferable low range. It becomes difficult.

  When the maximum protrusion height (Rp2) on the second surface 112 of the base material 11 exceeds 500 nm, the protrusion on the second surface 112 of the base material 11 when the release film 1 formed with the ceramic green sheet is wound up. The shape is transferred to the surface of the ceramic green sheet in contact with this surface, resulting in defects such as partial thinning of the ceramic green sheet. When a capacitor is produced by laminating the ceramic green sheet, a defect due to a short circuit occurs. There is a fear. On the other hand, when the maximum protrusion height (Rp2) of the second surface 112 of the base material 11 is less than 60 nm, the second surface 112 of the base material 11 becomes flat. Therefore, it becomes easy to entrain air on the surface where the substrate 11 is in contact with the roll. As a result, the substrate 11 being conveyed may meander or may be unwound when wound into a roll.

  In addition, on the surface opposite to the first surface 111 of the substrate 11, the same layer as the release agent layer 12 described later may be provided, or a layer different from the release agent layer 12 may be provided. The 2nd surface 112 of the base material 11 points out the surface on the opposite side to the base material 11 side among the surfaces of these layers.

2. Release agent layer The release agent layer 12 in the release film 1 according to the present embodiment includes a release agent composition (hereinafter referred to as "release agent composition") containing an active energy ray-curable component (A) and a photopolymerization initiator (B). It may be referred to as an object R ”). The release agent layer 12 is formed by curing the release agent composition R.

  The active energy ray-curable component (A) comprises a hydroxyl group-containing (meth) acrylate (a1) having at least three (meth) acryloyl groups on average in one molecule, a polyvalent isocyanate compound (a2), 1 A linear dimethylorganopolysiloxane (a3) having at least one hydroxyl group in the molecule and having a mass average molecular weight of 500 to 8000, a (meth) acrylate (a1), a polyvalent isocyanate compound (a2), and The reaction is carried out so that the amount of dimethylorganopolysiloxane (a3) relative to the total amount of dimethylorganopolysiloxane (a3) is 0.01 to 0.10 in terms of mass ratio. In the present specification, (meth) acrylate means both acrylate and methacrylate. The same applies to other similar terms.

  When the (meth) acrylate (a1), the polyvalent isocyanate compound (a2) and the dimethylorganopolysiloxane (a3) are reacted, the hydroxyl group of the (meth) acrylate (a1) and the hydroxyl group of the dimethylorganopolysiloxane (a3) are many. It reacts with the isocyanate group of the polyvalent isocyanate compound (a2), and (meth) acrylates (a1) or (meth) acrylate (a1) and dimethylorganopolysiloxane (a3) are chemically reacted with the polyvalent isocyanate compound (a2). Will be combined.

  When the release composition R containing the active energy ray-curable component (A) is irradiated with active energy rays, the (meth) acrylate (a1) forms a polymer by radical polymerization. Since dimethylorganopolysiloxane (a3), which is a release imparting component, is incorporated into the polymer by covalent bonding, it is suppressed from falling off from the release agent layer 12 that is a cured product of the release agent composition R. Therefore, migration of the peeling imparting component is suppressed with respect to the ceramic grease sheet formed on the release agent layer 12, and a highly reliable ceramic grease sheet can be formed with high yield. Moreover, when the dimethylorganopolysiloxane (a3), which is a peeling imparting component, is present as described above, the resulting release agent layer 12 exhibits good peelability.

  The (meth) acrylate (a1) is composed of a single compound or two or more compounds having a structure represented by the following general formula (1) or (2).

In the general formulas (1) and (2), X ^{1 to} X ¹⁰ each independently represent a (meth) acryloyl group or a hydroxyl group, and at least three of X ^{1 to} X ⁶ are (meth) acryloyl groups. And at least three of X ^{7 to} X ¹⁰ represent a (meth) acryloyl group.

  The (meth) acrylate (a1) has at least three (meth) acryloyl groups on average in one molecule, thereby exhibiting sufficient curability and exhibiting poor curing when irradiated with active energy rays. It is prevented from waking up. From this viewpoint, the number of (meth) acryloyl groups in one molecule of (meth) acrylate (a1) is preferably 5 or more.

  As the (meth) acrylate (a1), it is preferable to use a hydroxyl group-containing acrylate which does not contain a methacryloyl group and whose functional group is composed only of an acryloyl group and a hydroxyl group. Such a hydroxyl group-containing acrylate exhibits better curability. Among them, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, pentaerythritol triacrylate and pentane having the structure represented by the above general formula (1) or (2) It is preferable that the mixture is one or a mixture of two or more selected from erythritol tetraacrylate, and the average content of acryloyl groups is 3 or more per molecule, and the concentration is adjusted to 8 equivalents or more per kg. Those are particularly preferred.

  The polyvalent isocyanate compound (a2) is a compound having at least two isocyanate groups in one molecule. For example, aromatic polyvalent isocyanate such as tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, etc. Aliphatic polyisocyanates such as aliphatic polyisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, and the like, and biuret and isocyanurate forms, as well as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, castor Examples thereof include adducts that are a reaction product with a low-molecular active hydrogen-containing compound such as oil. Among these, hexamethylene diisocyanate and its isocyanurate body, which can lower the peel force and improve the peelability, are particularly preferable. The said polyvalent isocyanate compound (a2) can be used individually by 1 type or in combination of 2 or more types.

  Since dimethylorganopolysiloxane (a3) is reacted with (meth) acrylate (a1) via polyvalent isocyanate compound (a2), it is necessary to have at least one hydroxyl group in one molecule. Moreover, in order to express favorable peelability, a dimethylorganopolysiloxane (a3) needs to be linear form and a mass mean molecular weight is 500-8000. When the mass average molecular weight is within this range, stable releasability is exhibited and coatability is also improved. The mass average molecular weight is preferably 500 to 6000, and particularly preferably 500 to 5000. In addition, the mass mean molecular weight in this specification is the value of standard polystyrene conversion measured by the gel permeation chromatography (GPC) method.

  Examples of the dimethylorganopolysiloxane (a3) include those having a structure represented by the following general formula (3), (4) or (5). Especially, what has the structure shown in General formula (3) is preferable, and according to this, especially peel force can be made low and peelability can be improved. A combination of a compound having the structure represented by the general formula (5) and an isocyanurate of hexamethylene diisocyanate as the polyvalent isocyanate compound (a2) is also preferable because the peelability can be improved.

In the general formulas (3), (4) and (5), R ¹ , R ³ and R ⁶ each independently represent an alkyl group or an alkylene ether group, and R ² , R ⁴ , R ⁵ and R ⁷ Each independently represents an alkylene group or an alkylene ether group. n represents a positive integer.

  A commercial item can also be used as dimethylorganopolysiloxane (a3). Commercially available products include, for example, Chisso Silaplane FM-4411, FM-4421, FM-4425, FMDA11, FMDA21, FM0411, FM0421, FM0425, X22-160AS, KF-6001 manufactured by Shin-Etsu Chemical Co., Ltd. Examples thereof include KF-6002, KF-6003, X-22-170BX, X-22-170DX, X22-176DX, X-22-176F, among which silaplane FMDA11, FMDA21 and FM0411 are preferable.

  In the active energy ray-curable component (A), the amount of dimethylorganopolysiloxane (a3) relative to the total amount of (meth) acrylate (a1), polyvalent isocyanate compound (a2) and dimethylorganopolysiloxane (a3) is in a mass ratio. The reaction was carried out to 0.01 to 0.10. If the mass ratio is less than 0.01, it becomes difficult to obtain stable peelability. On the other hand, if the mass ratio exceeds 0.10, the charge amount of the release film increases when the release film wound up in a roll shape is fed out. For this reason, it becomes easy for foreign matter etc. to adhere to the surface of a peeling film, and when applying slurry, there is a possibility of generating a pinhole etc. on the coated surface. Moreover, coating property may deteriorate and a coating stripe etc. may be formed on the coating surface. That is, when the mass ratio is within the above range, it is possible to obtain a release agent composition R that stably exhibits excellent peelability and has good coatability. From this viewpoint, the mass ratio is preferably 0.01 to 0.07, and particularly preferably 0.01 to 0.05.

  Here, the value obtained by subtracting the total hydroxyl group content of the dimethylorganopolysiloxane (a3) from the total isocyanate group amount of the polyvalent isocyanate compound (a2) is greater than the total hydroxyl group content of the (meth) acrylate (a1). It is preferable to adjust so that it may become small. Further, when the active energy ray-curable component (A) is produced, the polyvalent isocyanate compound (a2) and the dimethylorganopolysiloxane (a3) are reacted first, and the (meth) acrylate (a1) is reacted therewith. It is preferable. By doing so, the amount of the dimethylorganopolysiloxane (a3) remaining without reacting with the (meth) acrylate (a1) can be reduced. The amount of siloxane (a3) transferred to the ceramic green sheet can be reduced.

  Examples of the photopolymerization initiator (B) contained in the release agent composition R include, for example, α-hydroxyketone compounds, α-aminoalkylphenone compounds, aromatic ketones containing thioxanthone, acylphosphine oxides, and the like. Is mentioned. Among these, an α-hydroxyketone compound and an α-aminoalkylphenone compound are preferable from the viewpoint of promoting a polymerization reaction and improving curability. The said photoinitiator (B) can be used individually by 1 type or in combination of 2 or more types.

  Examples of α-hydroxyketone compounds include 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methyl-propan-1-one. 2-hydroxy-4′-hydroxyethoxy-2-methylpropiophenone, 1-hydroxy-cyclohexyl-phenyl-ketone, oligo {2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl ] Propanone} and the like.

  Examples of the α-aminoalkylphenone compound include 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4 -Morpholinophenyl) -butanone-1,2-dimethylamino-2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone and the like.

  The content of the photopolymerization initiator (B) in the release agent composition R is preferably 2 to 15 parts by mass, particularly 4 to 12 parts per 100 parts by mass of the active energy ray-curable component (A). It is preferable that it is a mass part.

  The release agent composition R according to this embodiment may contain silica, an antistatic agent, a starting aid, a dye, a pigment, and other additives as necessary in addition to the above components.

  The thickness of the release agent layer 12 in the release film 1 according to this embodiment is 0.3 to 2 μm, preferably 0.3 to 1.5 μm, particularly 0.3 to 1.2 μm. Is preferred. When the thickness of the release agent layer 12 is less than 0.3 μm, the concave portion between the protrusions existing on the first surface 111 of the substrate 11 cannot be filled, and the smoothness of the surface 112 of the release agent layer 12 is obtained. It becomes insufficient, and pinholes and uneven thickness easily occur in the ceramic green sheet. On the other hand, when the thickness of the release agent layer 12 exceeds 2 μm, the release film 1 is likely to curl due to curing shrinkage of the release agent layer 12. Moreover, when the peeling film 1 is wound up in a roll shape, the second surface 112 of the substrate 11 and blocking are likely to occur.

  The arithmetic average roughness (Ra1) of the surface 121 of the release agent layer 12 is 8 nm or less, preferably 6 nm or less, and particularly preferably 4 nm or less. Further, the maximum protrusion height (Rp1) of the surface 121 of the release agent layer 12 is 50 nm or less, preferably 40 nm or less, and particularly preferably 30 nm or less.

  By making the arithmetic average roughness (Ra1) and the maximum protrusion height (Rp1) of the surface 121 of the release agent layer 12 within the above ranges, the surface 121 of the release agent layer 12 is made sufficiently high and smooth. For example, even when a thin film ceramic green sheet having a thickness of 1 μm or less is formed on the surface 121 of the release agent layer 12, defects such as pinholes and uneven thickness are hardly generated in the thin film ceramic green sheet. Slurry coatability is shown. Further, by making the arithmetic average roughness (Ra1) and the maximum protrusion height (Rp1) of the surface 121 of the release agent layer 12 in the above ranges, the peelability of the ceramic green sheet becomes excellent, for example, the thickness Even when a thin film ceramic green sheet having a thickness of 1 μm or less is peeled from the release agent layer 12, the ceramic green sheet is hardly broken.

  When the release agent layer 12 obtained by curing the release agent composition R is laminated on the first surface 111 of the substrate 11, the arithmetic average roughness (Ra1) and the maximum on the surface 121 of the release agent layer 12. The projection height (Rp1) can be within the above-described range. According to the release agent composition R, the release agent obtained by effectively filling the concave portions between the protrusions present on the first surface 111 of the substrate 11 mainly with the cured product of the active energy ray-curable component. The surface 121 of the layer 12 can be highly smoothed.

  Moreover, according to the release agent layer 12 formed by curing the release agent composition R, as described above, the transfer of the release imparting component to the ceramic grease sheet formed on the release agent layer 12 is suppressed. .

Specifically, after the polyvinyl butyral resin layer is formed on the surface 121 of the release agent layer 12, when the polyvinyl butyral resin layer is released from the release agent layer 12, the release agent layer 12 in the polyvinyl butyral resin layer comes into contact. The amount of silicone transferred on the surface that has been reduced decreases. The amount of silicone transferred can be evaluated by the silicon atom ratio measured by X-ray photoelectron spectroscopy (XPS). In the present embodiment, the silicon atom ratio obtained by measuring the surface is preferably less than 1.0 atom%, particularly preferably less than 0.5 atom%, and more preferably 0.3 atom % Or less is preferable. The silicon atom ratio is calculated by the following formula based on the amounts (XPS count number) of silicon atoms (Si), carbon atoms (C), and oxygen atoms (O).
Silicon atomic ratio (atomic%) = [(Si element amount) / (C element amount) + (O element amount) + (Si element amount)] × 100

  In addition, since the polyvinyl butyral resin layer itself is at a level at which silicon is not detected by XPS, the silicon atomic ratio is used as an evaluation standard for the migration amount of the silicone compound that is the release imparting component of the release agent layer 12. Can be used.

  When the ceramic green sheet is formed on the release agent layer 12 when the silicon atomic ratio of the surface in contact with the release agent layer 12 in the polyvinyl butyral resin layer is within the above range, the release agent layer on the ceramic green sheet is formed. 12 can be suppressed.

3. Manufacturing method of release film for ceramic green sheet manufacturing process The release film 1 according to this embodiment includes a release agent layer containing a release agent composition R and an organic solvent as required on the first surface 111 of the substrate 11. After the forming material is applied, it can be produced by drying as necessary and curing by irradiation with active energy rays to form the release agent layer 12. As a coating method of the release agent layer forming material, for example, a gravure coating method, a bar coating method, a spray coating method, a spin coating method, a knife coating method, a roll coating method, a die coating method and the like can be used.

  As the organic solvent, a conventionally known organic solvent can be used as long as the solubility of each component of the release agent layer forming material is good and it does not have reactivity. For example, aliphatic hydrocarbons such as hexane, heptane and cyclohexane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and ethylene chloride, methanol, ethanol, propanol (isopropyl alcohol), butanol, 1- Alcohols such as methoxy-2-propanol, ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone and cyclohexanone, esters such as ethyl acetate and butyl acetate, cellosolve solvents such as ethyl cellosolve, mixed solvents thereof and the like are used. Usually, the amount of the organic solvent used is preferably adjusted so that the solid concentration is in the range of 1 to 60% by mass.

As the active energy ray, ultraviolet rays, electron beams and the like are usually used, and ultraviolet rays are particularly preferable. The dose of the active energy ray varies depending on the type of the energy ray, for example, in the case of ultraviolet rays, preferably 50~1000mJ / cm ² in quantity, in particular 100 to 500 mJ / cm ² is preferred. Moreover, in the case of an electron beam, about 0.1-50 kGy is preferable.

  By irradiation with the active energy ray, the active energy ray-curable component (A) in the release agent composition R is polymerized and cured, and the release agent layer 12 is formed.

  In order to use the release film 1 described above, the ceramic green sheet is formed by applying a ceramic slurry to the surface 121 of the release agent layer 12 and drying using a slot die coating method, a doctor blade method, or the like. Mold. At this time, according to the release film 1 according to the present embodiment, a ceramic green sheet having high smoothness is formed even when a thin ceramic green sheet having excellent slurry coating properties and low strength is formed into a release agent layer. It is possible to suppress the occurrence of pinholes and uneven thickness. Moreover, the formed ceramic green sheet is easy to peel from the release film 1, and the peeling imparting component (silicone compound) is not easily transferred to the ceramic green sheet.

  Furthermore, even if the release film 1 on which the ceramic green sheet is formed is stored in a rolled state or transported by roll-to-roll, the surface state of the second surface 112 of the substrate 11 is maintained. As a result, the occurrence of defects such as partial thinning of the ceramic green sheet is suppressed. Furthermore, according to the release film 1, since blocking is unlikely to occur, it is possible to suppress problems such as winding failure and increase in charge amount during unwinding and adhesion of foreign matters. Therefore, according to the peeling film 1 which concerns on a present Example, a highly reliable ceramic green sheet can be manufactured with sufficient yield with favorable productivity.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  For example, another layer such as an antistatic layer may be provided between the surface of the substrate 11 opposite to the release agent layer 12 or between the substrate 11 and the release agent layer 12.

  EXAMPLES Hereinafter, although an Example etc. demonstrate this invention further more concretely, the scope of the present invention is not limited to these Examples etc.

[Production Example 1]
In a reactor equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer, 100 parts by mass of hexamethylene diisocyanate as a polyvalent isocyanate (a2) (in terms of solid content; the same shall apply hereinafter) and dimethylorganopolysiloxane (a3) (Manufactured by Chisso Corporation, product name “Silaplane FMDA11”, number average molecular weight 1000; having the structure represented by the general formula (3), R ¹ in the general formula (3) is —OH, R ² is — (CH ₂ ) ₃ OCH ₂ CH ₂ —, R ³ is —CH ₂ CH _3. The structure of the product is the same below.) 300 parts by mass and 400 parts by mass of methyl ethyl ketone are charged, heated to 85 ° C., and 7 hours. The reaction was obtained by incubating.

  In another reactor having the same equipment as above, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate as (meth) acrylate (a1) (product name “M-400”, manufactured by Toa Gosei Co., Ltd.) 50% by mass of pentaerythritol pentaacrylate; structure shown in the general formula (1)) 286 parts by mass, 12 parts by mass of the solid content of the reaction product obtained above, and 286 parts by mass of methyl ethyl ketone were charged and heated to 85 ° C. The mixture was heated and allowed to react for 7 hours, and it was confirmed by IR measurement that the isocyanate group had disappeared. Thus, an active energy ray-curable component (A1) was obtained.

[Production Example 2]
In a reactor equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer, 100 parts by mass of hexamethylene diisocyanate as the polyvalent isocyanate (a2) and dimethylorganopolysiloxane (a3) (manufactured by Chisso Corporation, product name “ Thylaplane FMDA11 ", number average molecular weight 1000) 300 parts by mass and methyl ethyl ketone 400 parts by mass were charged, heated to 85 ° C. and incubated for 7 hours to obtain a reaction product.

  In another reactor having the same equipment as above, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate as (meth) acrylate (a1) (product name “M-400” manufactured by Toagosei Co., Ltd .; (Structure shown in Formula (1)) 258 parts by mass, 40 parts by mass of the solid content of the reaction product obtained above, and 258 parts by mass of methyl ethyl ketone were charged, heated to 85 ° C. and kept for 7 hours to react. It was confirmed by IR measurement that the isocyanate group had disappeared, and an active energy ray-curable release agent compound (A2) was obtained.

[Production Example 3]
In a reactor equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer, 100 parts by mass of hexamethylene diisocyanate as the polyvalent isocyanate (a2) and dimethylorganopolysiloxane (a3) (manufactured by Chisso Corporation, product name “ Silaplane FMDA21 ”, number average molecular weight 5000; having the structure represented by the general formula (3), R ¹ in the general formula (3) is —OH, R ² is — (CH ₂ ) ₃ OCH ₂ CH ₂ —, R ³ is —CH ₂ CH ₃ ) 1488 parts by mass and 1588 parts by mass of methyl ethyl ketone were charged, the temperature was raised to 85 ° C., and the reaction was continued for 7 hours to obtain a reaction product.

  In another reactor having the same equipment as above, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate as (meth) acrylate (a1) (product name “M-400” manufactured by Toagosei Co., Ltd .; (Structure shown in Formula (1)) 289 parts by mass, 10 parts by mass of the solid content of the reaction product obtained above, and 289 parts by mass of methyl ethyl ketone were charged, heated to 85 ° C. and allowed to react for 7 hours. It was confirmed by IR measurement that the isocyanate group had disappeared, and an active energy ray-curable release agent compound (A3) was obtained.

[Production Example 4]
In a reactor equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer, 100 parts by mass of hexamethylene diisocyanate as the polyvalent isocyanate (a2) and dimethylorganopolysiloxane (a3) (manufactured by Chisso Corporation, product name “ Thylaplane FMDA11 ", number average molecular weight 1000) 300 parts by mass and methyl ethyl ketone 400 parts by mass were charged, heated to 85 ° C. and incubated for 7 hours to obtain a reaction product.

  In another reactor having the same equipment as above, a mixture of pentaerythritol tetraacrylate and pentaerythritol triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name “A-TMM-3L”, pentaerythritol triacrylate 55% by mass) Containing) 286 parts by mass, 12 parts by mass of the solid content of the reaction product obtained above, and 286 parts by mass of methyl ethyl ketone, heated to 85 ° C. and allowed to react for 7 hours, and the isocyanate group disappeared. This was confirmed by IR measurement, and an active energy ray-curable release agent compound (A4) was obtained.

[Production Example 5]
In a reactor equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer, 100 parts by mass of isocyanurate of hexamethylene diisocyanate as polyvalent isocyanate (a2) and dimethylorganopolysiloxane (a3) (manufactured by Chisso Corporation) , Product name “Silaplane FM0411”, number average molecular weight 1000; having the structure represented by the general formula (5), R ⁶ in the general formula (5) is —OH, and R ⁷ is —C ₃ H ₆ OC ₂ H ₄ -. a a) and 175 parts by weight, were charged methyl ethyl ketone 275 parts by mass, and reacted by incubating was heated to 85 ° C. 7 hours to obtain a reaction product.

  In another reactor having the same equipment as above, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate as (meth) acrylate (a1) (product name “M-400” manufactured by Toagosei Co., Ltd .; (Structure shown in formula (1)) 167 parts by mass, 8 parts by mass of the solid content of the reaction product obtained above, and 167 parts by mass of methyl ethyl ketone were charged, heated to 85 ° C. and kept for 7 hours to react. It was confirmed by IR measurement that the isocyanate group had disappeared, and an active energy ray-curable release agent compound (A5) was obtained.

[Production Example 6]
In a reactor equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer, 100 parts by mass of hexamethylene diisocyanate as the polyvalent isocyanate (a2) and dimethylorganopolysiloxane (a3) (manufactured by Chisso Corporation, product name “ Thylaplane FMDA11 ", number average molecular weight 1000) 300 parts by mass and methyl ethyl ketone 400 parts by mass were charged, heated to 85 ° C. and incubated for 7 hours to obtain a reaction product.

  In another reactor having the same equipment as above, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate as (meth) acrylate (a1) (product name “M-400” manufactured by Toagosei Co., Ltd .; (Structure shown in Formula (1)) 300 parts by mass, 3 parts by mass of the solid content of the reaction product obtained above, and 300 parts by mass of methyl ethyl ketone were charged, heated to 85 ° C. and incubated for 7 hours for reaction. It was confirmed by IR measurement that the isocyanate group had disappeared, and an active energy ray-curable release agent compound (A6) was obtained.

[Production Example 7]
In a reactor equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer, 100 parts by mass of hexamethylene diisocyanate as the polyvalent isocyanate (a2) and dimethylorganopolysiloxane (a3) (manufactured by Chisso Corporation, product name “ Thylaplane FMDA11 ", number average molecular weight 1000) 300 parts by mass and methyl ethyl ketone 400 parts by mass were charged, heated to 85 ° C. and incubated for 7 hours to obtain a reaction product.

  In another reactor having the same equipment as above, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate as (meth) acrylate (a1) (product name “M-400” manufactured by Toagosei Co., Ltd .; (Structure shown in Formula (1)) 250 parts by mass, 43 parts by mass of the solid content of the reaction product obtained above, and 250 parts by mass of methyl ethyl ketone were charged, heated to 85 ° C. and allowed to react for 7 hours. It was confirmed by IR measurement that the isocyanate group had disappeared, and an active energy ray-curable release agent compound (A7) was obtained.

[Production Example 8]
In a reactor equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer, 100 parts by mass of hexamethylene diisocyanate as the polyvalent isocyanate (a2) and dimethylorganopolysiloxane (a3) (manufactured by Chisso Corporation, product name “ Silaplane FMDA26 ", number average molecular weight of 15,000; has the structure represented by the general formula (3), ^{R 1} in the general formula (3) is -OH, ^{R 2} is _{- (CH 2) 3 OCH 2} CH 2 -, R ³ is —CH ₂ CH ₃ ) 4460 parts by mass and 4560 parts by mass of methyl ethyl ketone were charged, the temperature was raised to 85 ° C., and the reaction was continued for 7 hours to obtain a reaction product.

  In another reactor having the same equipment as above, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate as (meth) acrylate (a1) (product name “M-400” manufactured by Toagosei Co., Ltd .; (Structure shown in Formula (1)) 289 parts by mass, 9 parts by mass of the solid content of the reaction product obtained above, and 289 parts by mass of methyl ethyl ketone were charged, heated to 85 ° C. and incubated for 7 hours for reaction. It was confirmed by IR measurement that the isocyanate group had disappeared, and an active energy ray-curable release agent compound (A8) was obtained.

[Production Example 9]
In a reactor equipped with a stirrer, a reflux condenser, a dropping funnel and a thermometer, 100 parts by mass of hexamethylene diisocyanate as the polyvalent isocyanate (a2) and dimethylorganopolysiloxane (a3) (manufactured by Chisso Corporation, product name “ Thylaplane FMDA11 ", number average molecular weight 1000) 300 parts by mass and methyl ethyl ketone 400 parts by mass were charged, heated to 85 ° C. and incubated for 7 hours to obtain a reaction product.

  In another reactor having the same equipment as above, 286 parts by mass of 2-hydroxyethyl acrylate, 12 parts by mass of the solid content of the reaction product obtained above, and 286 parts by mass of methyl ethyl ketone were charged, and the temperature was raised to 85 ° C. The reaction was carried out by heating for 7 hours to confirm that the isocyanate group had disappeared, and an active energy ray-curable release agent compound (A9) was obtained.

  About the active energy ray-curable release agent compounds A1 to A9 obtained in Production Examples 1 to 9, the number of (meth) acryloyl groups in (meth) acrylate (a1), the molecular weight of dimethylorganopolysiloxane (a3), and Mass ratio of the amount of dimethylorganopolysiloxane (a3) to the total amount of (meth) acrylate (a1), polyvalent isocyanate compound (a2) and dimethylorganopolysiloxane (a3) (a3) / [(a1) + (a2 ) + (A3)]) is shown in Table 1.

[Example 1]
100 parts by mass of the active energy ray-curable component (A1) and 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-) as an α-hydroxyketone photopolymerization initiator (B1) 5 parts by mass of propionyl) -benzyl] -phenyl} -2-methyl-propan-1-one (manufactured by BASF, product name “IRGACURE127”) in a mixed solvent of isopropyl alcohol and methyl ethyl ketone (mass ratio 3: 1) The solid content concentration was diluted to 20% by mass to obtain a release agent layer forming material.

The obtained release agent layer forming material was used as a biaxially stretched polyethylene terephthalate (PET) film as a substrate (thickness 31 μm, arithmetic average roughness Ra0: 16 nm on the first surface, maximum protrusion height on the first surface) The first surface has a thickness Rp0: 196 nm, the second surface has an arithmetic average roughness Ra2: 16 nm, and the second surface has a maximum protrusion height Rp2: 196 nm. The bar has a thickness of 1 μm after curing. It was applied by a coater and dried at 80 ° C. for 1 minute. Then, ultraviolet rays were irradiated (accumulated light amount: 250 mJ / cm ² ), the release agent layer forming material was cured to form a release agent layer, and this was used as a release film. In addition, the thickness of the release agent layer is a result measured by a measurement method described later (the following examples and the like are the same).

[Example 2]
A release film was produced in the same manner as in Example 1 except that the active energy ray-curable component (A2) was blended in place of the active energy ray-curable component (A1).

Example 3
A release film was produced in the same manner as in Example 1 except that the active energy ray-curable component (A3) was blended in place of the active energy ray-curable component (A1).

Example 4
A release film was produced in the same manner as in Example 1 except that the active energy ray-curable component (A4) was blended in place of the active energy ray-curable component (A1).

Example 5
A release film was produced in the same manner as in Example 1 except that the active energy ray-curable component (A5) was blended in place of the active energy ray-curable component (A1).

Example 6
A release film was produced in the same manner as in Example 1 except that the thickness of the release agent layer was changed to 0.5 μm.

Example 7
A release film was produced in the same manner as in Example 1 except that the thickness of the release agent layer was changed to 1.9 μm.

Example 8
In place of the photopolymerization initiator (B1), 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropane-1- as an α-aminoalkylphenone photopolymerization initiator (B2) A release film was produced in the same manner as in Example 1 except that ON (made by BASF, product name “IRGACURE907”) was blended.

Example 9
Instead of the base material in Example 1, a biaxially stretched PET film (thickness 38 μm, arithmetic average roughness Ra0: 15 nm of the first surface, maximum protrusion height Rp0: 98 nm of the first surface, second surface A release film was produced in the same manner as in Example 1 except that the arithmetic average roughness Ra2: 15 nm and the maximum protrusion height Rp2 of the second surface (Rp2: 98 nm) were used.

Example 10
Instead of the base material in Example 1, a biaxially stretched PET film (thickness 38 μm, arithmetic average roughness Ra0: 35 nm of the first surface, maximum protrusion height Rp0: 471 nm of the first surface, second surface A release film was prepared in the same manner as in Example 1 except that the arithmetic average roughness Ra2: 35 nm and the maximum protrusion height Rp2: 471 nm of the second surface were used.

[Comparative Example 1]
A release film was produced in the same manner as in Example 1 except that the active energy ray-curable component (A6) was blended in place of the active energy ray-curable component (A1).

[Comparative Example 2]
A release film was produced in the same manner as in Example 1 except that the active energy ray-curable component (A7) was blended in place of the active energy ray-curable component (A1).

[Comparative Example 3]
A release film was produced in the same manner as in Example 1 except that the active energy ray-curable component (A8) was blended in place of the active energy ray-curable component (A1).

[Comparative Example 4]
A release film was produced in the same manner as in Example 1 except that the active energy ray-curable component (A9) was blended in place of the active energy ray-curable component (A1).

[Comparative Example 5]
99 parts by mass of dipentaerythritol hexaacrylate as an active energy ray-curable component, 1 part by mass of a methacryloyl group-containing silicone resin composition (manufactured by Shin-Etsu Chemical Co., Ltd., product name “X-62-164A”), and α-hydroxy 2-Hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methyl-propane-1- as ketone-based photopolymerization initiator (B1) 5 parts by mass of ON (manufactured by BASF, product name “IRGACURE127”) is diluted with a mixed solvent of isopropyl alcohol and methyl ethyl ketone (mass ratio 3: 1) to a solid content concentration of 20% by mass, and a release agent layer forming material Got. Using this release agent layer forming material, a release film was prepared in the same manner as in Example 1.

[Comparative Example 6]
A release film was produced in the same manner as in Example 1 except that the thickness of the release agent layer was changed to 0.2 μm.

[Comparative Example 7]
Instead of the base material in Example 1, a biaxially stretched PET film (thickness 38 μm, arithmetic average roughness Ra0: 42 nm of the first surface, maximum protrusion height Rp0: 619 nm of the first surface, second surface A release film was prepared in the same manner as in Example 1 except that the average roughness Ra2 of 42 nm and the maximum protrusion height Rp2 of the second surface (Rp2: 619 nm) were used.

[Comparative Example 8]
Instead of the substrate in Example 1, a biaxially stretched PET film (thickness 38 μm, arithmetic average roughness Ra0 of the first surface Ra0: 15 nm, maximum protrusion height Rp0 of the first surface Rp0: 105 nm, second surface A release film was prepared in the same manner as in Example 1 except that the arithmetic average roughness Ra2: 3 nm and the maximum protrusion height Rp2 of the second surface (Rp2: 15 nm) were used.

[Test Example 1] (Measurement of thickness of release agent layer)
The thickness (μm) of the release agent layer of the release films obtained in Examples and Comparative Examples was measured using a reflective film thickness meter (product name “F20” manufactured by Filmetrics). Specifically, after the release films obtained in Examples and Comparative Examples were cut to 100 × 100 mm, the release film was installed on the film thickness meter so that the surface opposite to the surface to be measured was on the suction stage side. The film thickness was measured at 10 locations on the surface of the release agent layer, and the average value was defined as the thickness of the release agent layer. The results are shown in Table 2.

[Test Example 2] (Measurement of surface roughness of release agent layer)
A double-sided tape was affixed to the glass plate, and the release films obtained in the examples and comparative examples were fixed to the glass plate via the double-sided tape so that the surface opposite to the surface to be measured was on the glass plate side. The arithmetic average roughness (Ra1; nm) and maximum protrusion height (Rp1; nm) on the surface of the release agent layer of the release film (exposed surface; the same applies hereinafter) and the surface roughness measuring machine (Mitutoyo) , Product name “SV-3000S4”, stylus type) and measured according to JIS B0601-1994. The results are shown in Table 2.

[Test Example 3] (Evaluation of silicone migration)
In a mixed solvent of toluene and ethanol (mass ratio 50:50), a polyvinyl butyral resin (manufactured by Sekisui Chemical Co., Ltd., product name “S-Lec B · K BL-S”, powder form) is dissolved to a solid content concentration of 20% by mass. A polyvinyl butyral resin solution was obtained. The obtained polyvinyl resin solution was applied to the release agent layer surface of the release film obtained in Examples and Comparative Examples with a bar coater so that the thickness after drying was 4 μm, and dried to form a polyvinyl resin layer. Formed.

The polyvinyl resin layer is peeled from the release film, and the surface of the polyvinyl resin layer that has been in contact with the surface of the release agent layer is measured by X-ray photoelectron spectroscopy (XPS), silicon atoms (Si), carbon atoms ( Based on the amount of C) and oxygen atoms (O) (XPS count number), the silicon atom ratio (atomic%) was calculated by the following formula.
Silicon atomic ratio (atomic%) = [(Si element amount) / (C element amount) + (O element amount) + (Si element amount)] × 100

The silicone migration was evaluated according to the following criteria. The results are shown in Table 3.
A: Silicon atomic ratio is less than 0.3 atomic% B: Silicon atomic ratio is 0.3 atomic% or more and less than 1.0 atomic% C: Silicon atomic ratio is 1.0 atomic% or more

[Test Example 4] (Evaluation of coating surface of release agent layer)
About the release film obtained by the Example and the comparative example, the state of the coating surface (surface) of a release agent layer was observed visually, and the coating surface of the release agent layer was evaluated by the following judgment criteria. The results are shown in Table 3.
A: There was no surface abnormality due to coating stripes B: Although there were some surface abnormalities due to coating stripes, there was no problem in use C: Coating stripes occurred on the entire coated surface, or extreme surface abnormalities occurred

[Test Example 5] (Evaluation of curability of release agent layer)
About the release films obtained in Examples and Comparative Examples, the surface of the release agent layer was reciprocated at a load of 1 kg / cm ² with a waste containing methyl ethyl ketone (product name “BEMCOT AP-2”) containing methyl ethyl ketone 10 Polished twice. Thereafter, the surface of the release agent layer was visually observed, and the curability of the release agent layer was evaluated according to the following criteria. In addition, in this test (Test Example 5), for samples with an evaluation of “C”, a sample satisfactory for performing other tests could not be obtained, and thus other tests were not performed. The results are shown in Table 3.
A: The release agent layer did not dissolve / drop off B: Part of the release agent layer was found to be dissolved C: The release agent layer was completely dissolved and dropped from the substrate

[Test Example 6] (Slurry coating property evaluation)
Barium titanate powder (BaTiO ₃ ; manufactured by Sakai Chemical Industry Co., Ltd., product name “BT-03”), polyvinyl butyral resin as a binder (manufactured by Sekisui Chemical Co., Ltd., product name “S-REC B / K BM-2”) ) 8 parts by mass and 4 parts by mass of dioctyl phthalate (manufactured by Kanto Chemical Co., Ltd., dioctyl phthalate deer grade 1) as a plasticizer, 135 parts by mass of a mixed solution of toluene and ethanol (mass ratio 6: 4), In the presence of zirconia beads, they were mixed and dispersed by a ball mill, and the beads were removed to prepare a ceramic slurry.

On the surface of the release agent layer of the release films obtained in Examples and Comparative Examples, the ceramic slurry was applied over a width of 250 mm and a length of 10 m so that the film thickness after drying with a die coater would be 1 μm. And dried at 80 ° C. for 1 minute in a dryer. About the release film in which the ceramic green sheet was shape | molded, the fluorescent lamp was illuminated from the release film side, all the molded ceramic green sheet surfaces were visually inspected, and slurry coating property was evaluated by the following judgment criteria. The results are shown in Table 3.
A: There were no pinholes in the ceramic green sheet B: 1-5 pinholes occurred in the ceramic green sheet C: Six or more pinholes occurred in the ceramic green sheet

[Test Example 7] (Ceramic green sheet peelability evaluation)
A ceramic green sheet formed on the surface of the release agent layer of the release film by the same procedure as in Test Example 6 was punched out to 200 mm × 200 mm without punching the release film. Next, using the sheet peeling mechanism of the green sheet laminating machine, the punched green sheet was adsorbed on a vacuum suction stage and peeled from the release film. The peelability of the ceramic green sheet at this time was evaluated according to the following criteria. The results are shown in Table 3.
A: The ceramic green sheet can be peeled off smoothly without tearing, and the ceramic green sheet did not remain on the release agent layer. B: The ceramic green sheet could be peeled off slightly without being broken, and on the release agent layer. There was no ceramic green sheet left on the surface. C ... The ceramic green sheet was torn or could not be peeled off.

[Test Example 8] (Defect evaluation of ceramic green sheet on the surface of the release agent layer)
In a mixed solvent of toluene and ethanol (mass ratio 60:40), a polyvinyl butyral resin (manufactured by Sekisui Chemical Co., Ltd., product name “ESREC B / K BL-S”, powdered) is dissolved to a solid content concentration of 20% by mass. A polyvinyl butyral resin solution was obtained. The obtained polyvinyl butyral resin solution was applied on the release agent layer of the release film obtained in Examples and Comparative Examples so that the thickness after drying was 3 μm, and dried at 80 ° C. for 1 minute. A polyvinyl butyral resin layer was molded. And the polyester adhesive tape was stuck on the surface of the polyvinyl butyral resin layer.

  Next, the release film was peeled from the polyvinyl butyral resin layer, and the polyvinyl butyral resin layer was transferred to a polyester adhesive tape. Thereafter, the number of dents on the surface of the polyvinyl butyral resin layer that was in contact with the surface of the release agent layer was counted. Specifically, using a light interference type surface shape observation device (product name “WYKO-1100” manufactured by Vecco), observation was performed at 50 magnifications in the PSI mode, and the obtained 91.2 × 119.8 μm was obtained. On the basis of the surface shape images in the range, the number of dents having a depth of 150 nm or more was counted.

Based on the number of depressions, the ceramic green sheet was evaluated for defects on the surface of the release agent layer according to the following criteria. In addition, in the above-described test for evaluating the peelability of the ceramic green sheet (Test Example 7), a sample that was evaluated as “C” could not obtain a satisfactory sample for performing this test. Did not. The results are shown in Table 3.
A: The number of dents is 0. B: The number of dents is 1-5. C: The number of dents is 6 or more. In addition, when a capacitor is manufactured with the ceramic green sheet in which the above-mentioned evaluation C exists, the obtained capacitor Is likely to cause a short circuit due to a decrease in withstand voltage.

[Test Example 9] (Defect evaluation of ceramic green sheet by the second surface of the substrate)
In a mixed solvent of toluene and ethanol (mass ratio 60:40), a polyvinyl butyral resin (manufactured by Sekisui Chemical Co., Ltd., product name “ESREC B / K BL-S”, powdered) is dissolved to a solid content concentration of 20% by mass. A polyvinyl butyral resin solution was obtained. The obtained polyvinyl butyral resin solution was applied onto a 50 μm thick PET film so that the thickness after drying was 3 μm, and dried at 80 ° C. for 1 minute to form a polyvinyl butyral resin layer.

The release films obtained in Examples and Comparative Examples were bonded to the polyvinyl butyral resin layer so that the second surface of the substrate in the release film was in contact with the polyvinyl butyral resin layer. The laminate was cut to 100 mm × 100 mm and then pressed with a load of 5 kg / cm ² to transfer the protrusion shape of the second surface of the substrate in the release film to the polyvinyl butyral resin layer.

  Next, the release film is peeled from the polyvinyl butyral resin layer, and the depth of the recess in the surface of the polyvinyl butyral resin film that has been in contact with the second surface of the substrate of the release film is measured, and the number of recesses is counted. It was. Specifically, using an optical interference type surface shape observation apparatus (Vecco, WYKO-1100), the surface in the range of 91.2 × 119.8 μm obtained by observing at a magnification of 50 in the PSI mode. Based on the shape image, the depth of the dent was measured and the number of dents was counted.

Based on the depth and number of the dents, a defect evaluation of the ceramic green sheet by the second surface of the substrate was performed according to the following criteria. The results are shown in Table 3.
A: The number of recesses having a depth of 300 nm or more is 0 B: The number of recesses having a depth of 500 nm or more is 0, and the number of recesses having a depth of 300 nm or more and less than 500 nm is 1 or more C: A recess having a depth of 500 nm or more In addition, when a capacitor is manufactured with the ceramic green sheet in which the dent of the evaluation C exists, the obtained capacitor is likely to be short-circuited due to a decrease in withstand voltage.

[Test Example 10] (Handling evaluation)
The handling properties when the release films obtained in Examples and Comparative Examples were made into rolls were evaluated. Specifically, the following judgment criteria evaluated the slipperiness | slidability of the peeling films which contacted, the good air bleed at the time of making it into a roll shape, and the difficulty of generating the winding gap of a peeling film. The results are shown in Table 3.
A ... Good slipperiness between peeled release films and good air escape when making the release film into a roll, and prevented winding film from slipping. B ... Slightly slippery contacted release films were slightly worse. When the release film was wound into a roll, the air escape was slightly worse, and there was no hindrance although some winding deviation occurred. C ... The slipperiness between the release films contacted was poor, and the release film was wound into a roll. The air escape was bad and the winding deviation was noticeable.

[Test Example 11] (Evaluation of blocking properties)
The release films obtained in Examples and Comparative Examples were rolled up into a roll having a width of 400 mm and a length of 5000 m. This release film roll was stored for 30 days in an environment of 40 ° C. and a humidity of 50% or less. The appearance of the release film roll as it was was visually observed, and the blocking property was evaluated according to the following criteria. The results are shown in Table 3.
A: There was no change from when it was rolled up (no blocking)
B: In the area of less than half in the width direction, a change in color due to adhesion between the films was observed (there is some blocking but can be used)
C: Over the majority region in the width direction, a change in color due to adhesion between films was observed (with blocking)

  As is clear from Table 3, the release films of the examples were excellent in the peelability of the ceramic green sheet, and the silicone compound (release imparting component) was not easily transferred to the ceramic green sheet. Moreover, according to the peeling film of an Example, it was hard to produce a defect in a ceramic green sheet, and also it was hard to generate | occur | produce blocking, and its handleability was also favorable.

DESCRIPTION OF SYMBOLS 1 ... Release film for ceramic green sheet manufacturing process 11 ... Base material 111 ... 1st surface 112 ... 2nd surface 12 ... Release agent layer 121 ... Surface

Claims (3)

A release film for a ceramic green sheet manufacturing process comprising a substrate having a first surface and a second surface, and a release agent layer provided on the first surface of the substrate,
The release agent layer is formed from a release agent composition containing an active energy ray-curable component (A) and a photopolymerization initiator (B),
The active energy ray-curable component (A) is
A hydroxyl group-containing (meth) acrylate (a1) having an average of at least three (meth) acryloyl groups in one molecule;
A polyvalent isocyanate compound (a2);
A linear dimethylorganopolysiloxane (a3) having at least one hydroxyl group in one molecule and having a mass average molecular weight of 500 to 8000,
The amount of the dimethylorganopolysiloxane (a3) relative to the total amount of the (meth) acrylate (a1), the polyvalent isocyanate compound (a2) and the dimethylorganopolysiloxane (a3) is 0.01 to 0.00 by mass ratio. Let it react to be 10,
The release agent layer has a thickness of 0.3-2 μm,
The arithmetic average roughness (Ra1) on the surface of the release agent layer opposite to the substrate is 8 nm or less, and the maximum protrusion height (Rp1) is 50 nm or less,
An arithmetic average roughness (Ra2) on the second surface of the substrate is 5 to 40 nm, and a maximum protrusion height (Rp2) is 60 to 500 nm. .   The release film for a ceramic green sheet production process according to claim 1, wherein the photopolymerization initiator (B) is an α-hydroxyketone compound or an α-aminoalkylphenone compound.   After the polyvinyl butyral resin layer is formed on the surface of the release agent layer opposite to the substrate, the release agent layer in the polyvinyl butyral resin layer is peeled off when the polyvinyl butyral resin layer is released from the release agent layer. The release film for a ceramic green sheet production process according to claim 1, wherein the silicon atom ratio measured by photoelectron spectroscopy analysis is less than 1.0 atomic% with respect to the surface in contact with the ceramic green sheet.

Images