KR102242066B1 - Release film for ceramic green sheet manufacturing process - Google Patents

Abstract

A release agent composition comprising a substrate 11 and a release agent layer 12 formed on the first side 111 of the substrate, and the release agent layer 12 contains an active energy ray-curable component (A) and a photopolymerization initiator (B). The active energy ray-curable component (A) is formed from a hydroxyl group-containing (meth)acrylate (a1) having at least three (meth)acryloyl groups on average per molecule, and a polyvalent isocyanate compound (a2), Amount of linear dimethylorganopolysiloxane (a3) having at least one hydroxyl group per molecule and having a mass average molecular weight of 500 to 8000 relative to the total amount of (a1), (a2) and (a3) It is made by reacting so as to be 0.01 to 0.10 in this mass ratio, the thickness of the release agent layer 12, the arithmetic mean roughness Ra1 and the maximum protrusion height Rp1 on the surface 121 of the release agent layer, and the second of the substrate. The release film 1 for a ceramic green sheet manufacturing process in which the arithmetic mean roughness Ra2 and the maximum protrusion height Rp2 on the surface 112 are in a predetermined range.

Description

Release film for ceramic green sheet manufacturing process {RELEASE FILM FOR CERAMIC GREEN SHEET MANUFACTURING PROCESS}

The present invention relates to a release film used in the process of manufacturing 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 the obtained ceramic green sheets are laminated 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 a release film, what formed a release agent layer by peeling treatment with a silicone compound, such as a polysiloxane, is usually used on a film base material.

In recent years, with the miniaturization and high performance of electronic devices, the miniaturization and multilayerization of multilayer ceramic capacitors and multilayer ceramic substrates have progressed, and the thin film of the ceramic green sheet is in progress. When the ceramic green sheet becomes thinner and the thickness after drying becomes, for example, 3 μm or less, pinholes in the ceramic green sheet originate from the surface state of the release agent layer in the release film when the ceramic slurry is coated and dried. And defects such as non-uniformity in thickness are liable to occur. Further, when the molded ceramic green sheet is peeled from the release film, problems such as fracture due to a decrease in strength of the ceramic green sheet are liable to occur.

Therefore, this peeling film is required for peelability which can peel the ceramic green sheet of a thin film formed on the peeling film from the peeling film without breaking or the like.

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 released when the ceramic slurry is coated. When the peeling film is released, static electricity tends to occur, and thus, trouble due to static electricity has been a problem. In order to solve this problem, Patent Literature 1 proposes to use a release film in which the arithmetic average roughness of the surface (back surface) opposite to the surface on which the release agent layer of the substrate is formed is made rough.

Patent Document 1: Japanese Laid-Open Patent Publication No. 2003-203822

However, in the case of using the release film described in Patent Document 1, when the ceramic green sheet is rolled up and stored, the rough surface shape of the back surface of the release film is transferred to the ceramic green sheet, so that the ceramic green sheet is partially thinned. When a defect occurred, and when a ceramic green sheet was laminated to fabricate a capacitor, there was a case where a problem caused by a short circuit occurred and curled.

On the other hand, if the arithmetic mean roughness of the rear surface of the release film is set to be small, the surface condition becomes flat and the sliding properties of the rolled-up release films deteriorate, so blocking occurs as described above, resulting in poor winding, etc. Causes the problem of.

Further, the ceramic green sheet is punched out to a predetermined size as a release film, and is peeled from the release film and laminated. At that time, when transfer of a peeling-imparting component (for example, a silicon-based compound) occurs on the surface of the ceramic green sheet in contact with the release agent layer, the adhesive strength between the ceramic green sheets is lowered, and as a result, a problem of lowering the yield occurs. . Therefore, there is a demand for a release film with little transfer of the peeling imparting component to the ceramic green sheet.

The present invention has been made in view of such a reality, and at the same time, it is excellent in peelability from the ceramic green sheet, and it is difficult to transfer the peeling imparting component to the ceramic green sheet, and it is possible to prevent and suppress the occurrence of defects in the ceramic green sheet In addition, it is an object of the present invention to provide a release film for a ceramic green sheet manufacturing process in which blocking is difficult to occur.

In order to achieve the above object, first, the present invention is a release film for a ceramic green sheet manufacturing process comprising a base material having a first side and a second side, and a release agent layer formed on the first side of the base material, the release agent The layer is formed of a release agent composition containing an active energy ray-curable component (A) and a photoinitiator (B), and the active energy ray-curable component (A) has at least three (meth)acryloyl groups on average per molecule. A hydroxyl group-containing (meth)acrylate (a1) having, a polyvalent isocyanate compound (a2), and a linear dimethylorganopolysiloxane (a3) having at least one hydroxyl group per molecule and having a mass average molecular weight of 500 to 8000. So that the amount of the dimethyl organopolysiloxane (a3) with respect to the total amount of the (meth)acrylate (a1), the polyvalent isocyanate compound (a2), and the dimethyl organopolysiloxane (a3) is 0.01 to 0.10 by mass ratio. Reaction, the thickness of the release agent layer is 0.3 to 2 µm, the arithmetic mean roughness (Ra1) on the side opposite to the substrate of the release agent layer is 8 nm or less, and the maximum protrusion height (Rp1) Is 50 nm or less, 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 release film for use is provided (Invention 1).

According to the release film for the ceramic green sheet manufacturing process according to the invention (invention 1), since the release agent layer is composed of the release agent composition, the peeling property from the ceramic green sheet is excellent, and the peeling imparting component is transferred to the ceramic green sheet. It's hard to be. In addition, since the thickness of the release agent layer and the surface conditions of the release agent layer and the substrate are defined as described above, it is possible to prevent and suppress the occurrence of defects in the ceramic green sheet, and furthermore, blocking is less likely to occur.

In the above invention (invention 1), it is preferable that the photoinitiator (B) is an α-hydroxyketone-based compound or an α-aminoalkylphenone-based compound (invention 2).

In the above invention (Inventions 1 and 2), after forming a polyvinyl butyral resin layer on the side opposite to the substrate of the release agent layer, when the polyvinyl butyral resin layer is peeled from the release agent layer, With respect to the surface of the polyvinyl butyral resin layer in contact with the release agent layer, it is preferable that the silicon atom ratio measured by photoelectron spectroscopy is 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 peeling property from the ceramic green sheet, and the peeling imparting component is difficult to transfer to the ceramic green sheet, and defects occur in the ceramic green sheet. It can be prevented and suppressed, and furthermore, blocking is difficult to occur.

1 is a cross-sectional view of a release film for a ceramic green sheet manufacturing process according to an embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described.

[Releasable film for ceramic green sheet manufacturing process]

As shown in FIG. 1, the release film 1 for the ceramic green sheet manufacturing process according to the present embodiment (hereinafter, it may be simply referred to as “release film 1”) is a substrate 11 and a substrate ( It is constituted by including the release agent layer 12 laminated on the first surface 111 (the upper surface in Fig. 1) of 11). The substrate 11 is provided with a second surface 112 on a surface (a lower surface in FIG. 1) opposite to the first surface 111 of the base material 11.

1. Description

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, and plastics such as polycarbonate and polyvinyl acetate. A single layer may be sufficient, and a multilayer of two or more layers of the same type or different types may be used. 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 does not readily generate dust or the like during processing or use, it is possible to effectively prevent, for example, poor ceramic slurry coating due to dust or the like. Further, by subjecting the polyethylene terephthalate film to an antistatic treatment, the effect of preventing coating defects and the like can be enhanced.

In addition, in this substrate 11, for the purpose of improving the adhesion with the release agent layer 12, if desired, on both sides of the first side 111 or the first side 111 and the second side 112, Surface treatment by an oxidation method, an uneven method, or the like, or a 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. Sandblasting method, thermal spraying treatment method, etc. are mentioned. These surface treatment methods are appropriately selected depending on the type of the base film, but in general, the corona discharge treatment method is preferably used in terms of effect and operability.

The thickness of the substrate 11 is usually 10 to 300 µm, preferably 15 to 200 µm, and particularly preferably 20 to 125 µm.

The arithmetic mean roughness Ra0 of 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 mean roughness (Ra0) and the maximum protrusion height (Rp0) on the first surface 111 of the substrate 11 in the above range, the surface 121 of the release agent layer 12 (the It becomes easy to collect the arithmetic mean roughness Ra1 and the maximum protrusion height Rp1 in the opposite surface) within the ranges described later.

The arithmetic mean roughness Ra2 of 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. Further, the maximum protrusion height Rp2 on the second surface 112 of the substrate 11 is 60 to 500 nm, preferably 100 to 400 nm. Ceramic green due to the second surface 112 of the substrate 11 by setting the arithmetic mean roughness (Ra2) and the maximum protrusion height (Rp2) on the second surface 112 of the substrate 11 in the above ranges. The occurrence of defects in the sheet can be prevented and suppressed, and the occurrence of blocking can be suppressed.

That is, if the arithmetic mean roughness (Ra2) of the second surface 112 of the substrate 11 is less than 5 nm, the second surface 112 becomes too smooth, and when the release film 1 is wound up, the substrate ( The second surface 112 of 11) and the highly smooth release agent layer 12 are in close contact with each other, so that blocking is liable to occur. On the other hand, when the arithmetic mean roughness (Ra2) of the second surface 112 of the substrate 11 exceeds 40 nm, the maximum protrusion height (Rp2) of the second surface 112 of the substrate 11 is set to the preferred lower range. It becomes difficult to deal with it.

When the maximum protrusion height Rp2 on the second surface 112 of the substrate 11 exceeds 500 nm, when the release film 1 formed of the ceramic green sheet is wound up, the second surface of the substrate 11 is When the protrusion shape of the surface 112 is transferred to the surface of the ceramic green sheet in contact with this surface, defects such as partial thinning of the ceramic green sheet occur, and when the ceramic green sheet is laminated to produce a capacitor, a short circuit occurs. There is a fear that a problem may arise. On the other hand, if the maximum protrusion height (Rp2) of the second surface 112 of the substrate 11 is less than 60 nm, the second surface 112 of the substrate 11 becomes flat, so that the release agent layer 12 is formed. In the process of doing so, it becomes easy to draw in air from the surface of the substrate 11 in contact with the roll. As a result, the substrate 11 being conveyed may meander, or misalignment of winding may occur when winding up in a roll shape.

In addition, on the surface opposite to the first surface 111 of the substrate 11, the same layer as the releasing agent layer 12 to be described later may be formed, or a layer different from the releasing agent layer 12 may be formed. In this case, the second surface 112 of the base material 11 refers to a surface of these layers on the opposite side to the base material 11 side.

2. Release agent layer

The release agent layer 12 in the release film 1 according to the present embodiment is a release agent composition containing an active energy ray-curable component (A) and a photopolymerization initiator (B) (hereinafter referred to as ``release agent composition (R)''). There are cases). The release agent layer 12 is formed by curing the release agent composition (R).

The active energy ray-curable component (A) is a 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 mass average molecular weight of 500 to 8000 is obtained from (meth)acrylate (a1), polyvalent isocyanate compound (a2), and dimethylorganopolysiloxane (a3). It is obtained by reacting so that the amount of dimethylorganopolysiloxane (a3) with respect to the total amount is 0.01 to 0.10 in terms of mass ratio. In addition, in this specification, (meth)acrylate means both an acrylate and a methacrylate. Other similar terms are the same.

When the (meth)acrylate (a1), polyvalent isocyanate compound (a2) and dimethyl organopolysiloxane (a3) are reacted, the hydroxyl group of (meth)acrylate (a1) and the hydroxyl group of dimethyl organopolysiloxane (a3) are polyvalent. By reacting with the isocyanate group of the isocyanate compound (a2), (meth)acrylate (a1) or (meth)acrylate (a1) and dimethylorganopolysiloxane (a3) are chemically bonded by a polyvalent isocyanate compound (a2). It will be.

When the release agent composition (R) containing the active energy ray-curable component (A) is irradiated with an active energy ray, the (meth)acrylate (a1) forms a polymer by radical polymerization. Since dimethylorganopolysiloxane (a3), which is a peeling-imparting component, is introduced into the polymer by a covalent bond, it is suppressed from falling off from the release agent layer 12, which is a cured product of the release agent composition (R). Therefore, transfer of the peeling imparting component to the ceramic green sheet formed on the release agent layer 12 is suppressed, and a highly reliable ceramic green sheet can be formed in a good yield. In addition, when dimethylorganopolysiloxane (a3), which is a peeling imparting component, is present as described above, the obtained peeling agent layer 12 exhibits good peeling properties.

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

[Formula 1]

[Formula 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 3 or more of X 1 to X 6} are (meth)acryloyl groups. Represents, and at least three or more of ^{X 7 to X 10} represent a (meth)acryloyl group.

The (meth)acrylate (a1) exhibits sufficient curability by having at least three (meth)acryloyl groups on average per molecule, and is prevented from causing curing failure when irradiated with active energy rays. From this point of view, the number of (meth)acryloyl groups in one molecule of (meth)acrylate (a1) is preferably 5 or more.

As (meth)acrylate (a1), it is preferable to use a hydroxyl group-containing acrylate which does not contain a methacryloyl group, and a functional group consists only of an acryloyl group and a hydroxyl group. Such a hydroxyl group-containing acrylate exhibits more favorable curing properties. Among them, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, which have a structure represented by the general formula (1) or (2), It is preferable that it is 1 type or a mixture of 2 or more types selected from pentaerythritol triacrylate and pentaerythritol tetraacrylate, and the acryloyl group it contains is 3 or more in 1 molecule on average, and its concentration is 1 kg It is particularly preferred that it is adjusted to at least 8 equivalents per sugar.

The polyvalent isocyanate compound (a2) is a compound having at least two isocyanate groups in one molecule, for example, tolylene diisocyanate, diphenylmethane diisocyanate, and aromatic polyvalent isocyanate such as xylylene diisocyanate, and hexamethylene diisocyanate. Alicyclic polyvalent isocyanates such as aliphatic polyhydric isocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, and the like, and their biuret body, isocyanurate body, and further ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, And adduct bodies which are reactants of low molecular weight active hydrogen-containing compounds such as castor oil. Among these, hexamethylene diisocyanate and its isocyanurate body, which can improve the peelability by lowering the peeling force, are particularly preferable. The polyvalent isocyanate compound (a2) may be used alone or in combination of two or more.

Since the dimethylorganopolysiloxane (a3) reacts with the (meth)acrylate (a1) via the polyvalent isocyanate compound (a2), it is necessary to have at least one hydroxyl group in one molecule. Further, in order to express good releasability, dimethylorganopolysiloxane (a3) needs to be linear and have a mass average molecular weight of 500 to 8000. When the mass average molecular weight is in this range, stable releasability is exhibited, and coatability is also improved. It is preferable that it is 500-6000, and, as for a mass average molecular weight, it is especially preferable that it is 500-5000. In addition, the mass average molecular weight in this specification is a value in terms of standard polystyrene measured by a gel permeation chromatography (GPC) method.

Examples of the dimethyl organopolysiloxane (a3) include those having a structure represented by the following general formulas (3), (4) or (5). Among them, it is preferable to have a structure represented by the general formula (3), and according to this, in particular, it is possible to improve the peelability by lowering the peeling force. In addition, it is preferable to have a structure represented by the general formula (5) and a polyvalent isocyanate compound (a2) in which an isocyanurate body of hexamethylene diisocyanate is combined because the releasability can be improved.

[Formula 3]

[Formula 4]

[Formula 5]

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 are each independently Represents an alkylene group or an alkylene ether group. n represents a positive integer.

As the dimethyl organopolysiloxane (a3), a commercial item can also be used. As a commercial item, for example, Chisso's Silaplane FM-4411, FM-4421, FM-4425, FMDA11, FMDA21, FM0411, FM0421, FM0425 I, Shin-Etsu Chemical Co., Ltd. X22-160AS, KF-6001, KF-6002, KF-6003, X-22-170BX, X-22-170DX, X22-176DX, X-22-176F, etc. are mentioned. Among them, Cyraffrene FMDA11, FMDA21 and FM0411 desirable.

As for the active energy ray-curable component (A), the amount of dimethylorganopolysiloxane (a3) to the total amount of (meth)acrylate (a1), polyvalent isocyanate compound (a2), and dimethyl organopolysiloxane (a3) is 0.01 in terms of mass ratio. It was reacted so that it might become -0.10. If the mass ratio is less than 0.01, it becomes difficult to obtain stable peelability. On the other hand, when the mass ratio exceeds 0.10, the charge amount of the release film increases when the release film wound in a roll shape is released. For this reason, foreign matter or the like is liable to adhere to the surface of the release film, and there is a possibility that pinholes or the like are generated on the coated surface when applying the slurry. Further, the coating property is deteriorated, and there are cases where a coating stem-like trace or the like occurs on the coating surface. That is, when the mass ratio is within the above range, excellent peelability can be stably expressed, and a peeling agent composition (R) having good coatability can be obtained. From this point of view, the mass ratio is preferably 0.01 to 0.07, particularly preferably 0.01 to 0.05.

Here, the value obtained by subtracting the total amount of hydroxyl groups of the dimethyl organopolysiloxane (a3) from the total amount of isocyanate groups of the polyvalent isocyanate compound (a2) is adjusted to be smaller than the total amount of hydroxyl groups of the (meth)acrylate (a1). desirable. In addition, when preparing the active energy ray-curable component (A), it is preferable to first react a polyvalent isocyanate compound (a2) with a dimethyl organopolysiloxane (a3), and react with a (meth)acrylate (a1) thereto. By doing as described above, the amount of the dimethylorganopolysiloxane (a3) that remains without reacting with the (meth)acrylate (a1) is reduced, and therefore, the dimethylorganopolysiloxane (a3), which is a peeling component, is ceramic It can reduce the amount of transfer to the green sheet.

Examples of the photopolymerization initiator (B) contained in the release agent composition (R) include aromatic ketones including α-hydroxyketone compounds, α-aminoalkylphenone compounds, thioxanthone, and acylphosphine oxides. And the like. Among these, an α-hydroxyketone compound and an α-aminoalkylphenone compound are preferable from the viewpoint of promoting the polymerization reaction and improving curability. The photopolymerization initiator (B) may be used alone or in combination of two or more.

As an α-hydroxyketone-based compound, for example, 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} etc. are mentioned.

As an α-aminoalkylphenone-based compound, for example, 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, and particularly preferably 4 to 12 parts by mass with respect to 100 parts by mass of the active energy ray-curable component (A).

In addition to the above components, the release agent composition (R) according to the present embodiment may contain silica, an antistatic agent, an initiation aid, a dye, a pigment, or other additives as necessary.

The thickness of the release agent layer 12 in the release film 1 according to the present embodiment is 0.3 to 2 µm, preferably 0.3 to 1.5 µm, and particularly preferably 0.3 to 1.2 µm. If the thickness of the release agent layer 12 is less than 0.3 μm, the smoothness of the surface 121 of the release agent layer 12 is insufficient because the concave portions between the protrusions present on the first surface 111 of the substrate 11 cannot be completely filled. As a result, pinholes and uneven thickness are easily generated in the ceramic green sheet. On the other hand, when the thickness of the release agent layer 12 exceeds 2 µm, curling is likely to occur in the release film 1 due to curing shrinkage of the release agent layer 12. In addition, when the release film 1 is wound up in a roll shape, blocking with the second surface 112 of the substrate 11 tends to occur.

The arithmetic mean 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 setting the arithmetic mean roughness (Ra1) and the maximum protrusion height (Rp1) of the surface 121 of the release agent layer 12 into the above-described ranges, the surface 121 of the release agent layer 12 can be made sufficiently high-smooth. Thus, 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 thickness irregularities are unlikely to occur in the thin-film ceramic green sheet. It shows slurry coatability. In addition, by making the arithmetic mean roughness (Ra1) and the maximum protrusion height (Rp1) of the surface 121 of the release agent layer 12 in the above ranges, the peelability from the ceramic green sheet is also excellent, for example, the thickness Even when the thin ceramic green sheet of 1 µm or less is peeled from the release agent layer 12, the ceramic green sheet is not easily broken.

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

Further, according to the release agent layer 12 formed by curing the release agent composition (R), as described above, transfer of the peeling imparting component to the ceramic green sheet formed on the release agent layer 12 is suppressed.

Specifically, after forming a polyvinyl butyral resin layer on the surface 121 of the release agent layer 12, when the polyvinyl butyral resin layer is peeled from the release agent layer 12, the polyvinyl butyral resin layer The amount of silicon migration on the surface in contact with the release agent layer 12 decreases. As the silicon transfer amount, its performance can be evaluated by the ratio of silicon atoms measured by X-ray photoelectron spectroscopy (XPS). In this embodiment, the silicon atom ratio obtained by measuring the surface is preferably less than 1.0 atomic%, particularly preferably less than 0.5 atomic%, and more preferably 0.3 atomic% or less. In addition, the silicon atom ratio is calculated by the following formula based on the amount of the silicon atom (Si), the carbon atom (C), and the oxygen atom (O) (XPS count number).

Silicon atomic ratio (atomic%) = [(Si element amount)/(C element amount)+(O element amount)+(Si element amount)] × 100

In addition, since most of the polyvinyl butyral resin layer itself is at a level at which no silicon is detected by XPS, the silicon atom ratio is used as a criterion for evaluating the amount of transfer of the silicone-based compound as a peeling component of the release agent layer 12. Can be used.

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

3. Manufacturing method of release film for ceramic green sheet manufacturing process

In the release film 1 according to the present embodiment, after applying a release agent composition (R) and, if desired, a release agent layer-forming material containing an organic solvent, to the first surface 111 of the substrate 11, dry as necessary. Then, it can be produced by curing by irradiation with active energy rays to form the release agent layer 12. As a method of applying the material for forming a release agent layer, 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, or the like can be used.

As the organic solvent, as long as the solubility of each component of the material for forming a release agent layer is good and does not have reactivity, a conventionally known solvent can be used. 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-methyl Alcohols such as oxy-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, These mixed solvents and the like are used. The amount of the organic solvent used is preferably adjusted so that the solid content concentration is usually 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. Although 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 amount of light is preferably 50 to 1000 mJ/cm 2, and particularly preferably 100 to 500 mJ/cm 2. In the case of an electron beam, about 0.1 to 50 kGy is preferable.

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

In order to use the release film 1 described above, a ceramic green sheet is formed by coating and drying the ceramic slurry on the surface 121 of the release agent layer 12 using a slot die coating method, a doctor blade method, or the like. At this time, according to the release film 1 according to the present embodiment, a ceramic green sheet having high smoothness can be formed even when a thin ceramic green sheet having excellent slurry coatability and low strength is formed on the release agent layer. Thus, it is possible to suppress the occurrence of pinholes and thickness unevenness. In addition, the formed ceramic green sheet is easily peeled from the peeling film 1, and the peeling imparting component (silicon compound) is hardly transferred to the ceramic green sheet.

In addition, even if the release film 1 on which the ceramic green sheet is formed is stored in a rolled state or conveyed by roll-to-roll, the ceramic green sheet originates from the surface state of the second surface 112 of the substrate 11. The occurrence of defects such as partial thinning is suppressed. Further, according to the release film 1, since blocking is unlikely to occur, problems such as poor winding or an increase in the amount of charge when unwinding can be suppressed, such as adhesion of foreign substances. Therefore, according to the release film 1 according to the present embodiment, a highly reliable ceramic green sheet can be produced with good productivity and good yield.

The embodiments described above are described to facilitate understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents falling within the technical scope of the present invention.

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

Example

Hereinafter, the present invention will be described more specifically by examples and the like, but the scope of the present invention is not limited to these examples and the like.

[Production Example 1]

In a reactor equipped with a stirrer, reflux condenser, dropping funnel, and thermometer, 100 parts by mass of hexamethylene diisocyanate as polyvalent isocyanate (a2) (in terms of solid content; hereinafter the same) and dimethylorganopolysiloxane (a3) (manufactured by Chisso Corporation, product name "Syraprene FMDA11", number average molecular weight 1000; It has a structure represented by general formula (3), and R ¹ in 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 were injected, the temperature was raised to 85°C, and the reaction was carried out for 7 hours to obtain a reaction product. .

In a separate reactor having the same equipment as above, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate as (meth)acrylate (a1) (manufactured by Toa Synthetic Company, product name ``M-400'', Containing 50% by mass of pentaerythritol pentaacrylate; 286 parts by mass of the structure represented by the general formula (1), 12 parts by mass of the solid content of the reactant obtained above, and 286 parts by mass of methyl ethyl ketone were added, and the temperature was raised to 85°C. It kept warm for 7 hours and made it react, it confirmed by IR measurement that an isocyanate group disappeared, and the active energy ray-curable component (A1) was obtained.

[Production Example 2]

In a reactor equipped with a stirrer, reflux condenser, dropping funnel, and thermometer, 100 parts by mass of hexamethylene diisocyanate as polyvalent isocyanate (a2), and dimethylorganopolysiloxane (a3) (manufactured by Chisso Corporation, product name ``Syraprene FMDA11'', 300 parts by mass of number average molecular weight 1000) and 400 parts by mass of methyl ethyl ketone were injected, the temperature was raised to 85°C, and the mixture was kept warm for 7 hours to obtain a reaction product.

In a separate reactor having the same equipment as above, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate as (meth)acrylate (a1) (manufactured by Toa Synthetic Corporation, product name “M-400”; General) Structure represented by formula (1)) 258 parts by mass, 40 parts by mass of the solid content of the reactant obtained above, and 258 parts by mass of methyl ethyl ketone were injected, the temperature was raised to 85°C, and the reaction was carried out by keeping the temperature for 7 hours. It confirmed by IR measurement, and the 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 polyvalent isocyanate (a2), and dimethylorganopolysiloxane (a3) (manufactured by Chisso, product name ``Syraprene FMDA21'', Number average molecular weight 5000; Having a structure represented by General Formula (3), R ¹ in 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 injected, the temperature was raised to 85°C, and the mixture was kept warm for 7 hours to obtain a reaction product.

In a separate reactor having the same equipment as above, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate as (meth)acrylate (a1) (manufactured by Toa Synthetic Corporation, product name “M-400”; General) Structure represented by formula (1)) 289 parts by mass, 10 parts by mass of the solid content of the reactant obtained above, and 289 parts by mass of methyl ethyl ketone were injected, the temperature was raised to 85°C, and the reaction was carried out by keeping the temperature for 7 hours. It confirmed by IR measurement, and the active energy ray-curable release agent compound (A3) was obtained.

[Production Example 4]

In a reactor equipped with a stirrer, reflux condenser, dropping funnel, and thermometer, 100 parts by mass of hexamethylene diisocyanate as polyvalent isocyanate (a2), and dimethylorganopolysiloxane (a3) (manufactured by Chisso Corporation, product name ``Syraprene FMDA11'', 300 parts by mass of number average molecular weight 1000) and 400 parts by mass of methyl ethyl ketone were injected, the temperature was raised to 85°C, and the mixture was kept warm for 7 hours to obtain a reaction product.

In a separate reactor having the same equipment as above, a mixture of pentaerythritol tetraacrylate and pentaerythritol triacrylate (manufactured by Shin-Nakamura Chemical Industries, product name ``A-TMM-3L'', pentaerythritol triacrylate 55 mass) % Contained) 286 parts by mass, 12 parts by mass of the solid content of the reactant obtained above, and 286 parts by mass of methyl ethyl ketone were injected, the temperature was raised to 85°C, and the reaction was carried out by keeping the temperature for 7 hours, and the disappearance of the isocyanate group was confirmed by IR measurement. Then, 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 the isocyanurate body of hexamethylene diisocyanate as polyvalent isocyanate (a2), and dimethylorganopolysiloxane (a3) (manufactured by Chisso Corporation, product name `` Cyraffrene FM0411", number average molecular weight 1000; It has a structure represented by general formula (5), and R ⁶ in general formula (5) is -OH, and R ⁷ is -C ₃ H ₆ OC ₂ H _4- ) 175 parts by mass and 275 parts by mass of methyl ethyl ketone were injected, the temperature was raised to 85°C, and the mixture was kept warm for 7 hours to obtain a reaction product.

In a separate reactor having the same equipment as above, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate as (meth)acrylate (a1) (manufactured by Toa Synthetic Corporation, product name “M-400”; General) Structure shown in formula (1)) 167 parts by mass, 8 parts by mass of the solid content of the reactant obtained above, and 167 parts by mass of methyl ethyl ketone were injected, the temperature was raised to 85°C, and the reaction was carried out by keeping the temperature for 7 hours. It confirmed by IR measurement, and the active energy ray-curable release agent compound (A5) was obtained.

[Production Example 6]

In a reactor equipped with a stirrer, reflux condenser, dropping funnel, and thermometer, 100 parts by mass of hexamethylene diisocyanate as polyvalent isocyanate (a2), and dimethylorganopolysiloxane (a3) (manufactured by Chisso Corporation, product name ``Syraprene FMDA11'', 300 parts by mass of number average molecular weight 1000) and 400 parts by mass of methyl ethyl ketone were injected, the temperature was raised to 85°C, and the mixture was kept warm for 7 hours to obtain a reaction product.

In a separate reactor having the same equipment as above, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate as (meth)acrylate (a1) (manufactured by Toa Synthetic Corporation, product name “M-400”; General) Structure represented by formula (1)) 300 parts by mass, 3 parts by mass of the solid content of the reactant obtained above, and 300 parts by mass of methyl ethyl ketone were injected, the temperature was raised to 85°C, and the reaction was carried out by keeping the temperature for 7 hours. It confirmed by IR measurement, and the active energy ray-curable release agent compound (A6) was obtained.

[Production Example 7]

In a reactor equipped with a stirrer, reflux condenser, dropping funnel, and thermometer, 100 parts by mass of hexamethylene diisocyanate as polyvalent isocyanate (a2), and dimethylorganopolysiloxane (a3) (manufactured by Chisso Corporation, product name ``Syraprene FMDA11'', 300 parts by mass of number average molecular weight 1000) and 400 parts by mass of methyl ethyl ketone were injected, the temperature was raised to 85°C, and the mixture was kept warm for 7 hours to obtain a reaction product.

In a separate reactor having the same equipment as above, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate as (meth)acrylate (a1) (manufactured by Toa Synthetic Corporation, product name “M-400”; General) Structure represented by formula (1)) 250 parts by mass, 43 parts by mass of solid content of the reactant obtained above, and 250 parts by mass of methyl ethyl ketone were injected, the temperature was raised to 85°C, and the reaction was carried out by keeping the temperature for 7 hours. It confirmed by IR measurement, and the active energy ray-curable release agent compound (A7) was obtained.

[Production Example 8]

In a reactor equipped with a stirrer, reflux condenser, dropping funnel, and thermometer, 100 parts by mass of hexamethylene diisocyanate as polyvalent isocyanate (a2), and dimethylorganopolysiloxane (a3) (manufactured by Chisso, product name ``Syraprene FMDA26'', Number average molecular weight 15000; Having a structure represented by General Formula (3), R ¹ in 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 injected, the temperature was raised to 85° C., and the mixture was kept warm for 7 hours to obtain a reaction product.

In a separate reactor having the same equipment as above, a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate as (meth)acrylate (a1) (manufactured by Toa Synthetic Corporation, product name “M-400”; General) Structure shown in formula (1)) 289 parts by mass, 9 parts by mass of the solid content of the reactant obtained above, and 289 parts by mass of methyl ethyl ketone were injected, the temperature was raised to 85°C, and the reaction was carried out by keeping the temperature for 7 hours. It confirmed by IR measurement, and the active energy ray-curable release agent compound (A8) was obtained.

[Production Example 9]

In a reactor equipped with a stirrer, reflux condenser, dropping funnel, and thermometer, 100 parts by mass of hexamethylene diisocyanate as polyvalent isocyanate (a2), and dimethylorganopolysiloxane (a3) (manufactured by Chisso Corporation, product name ``Syraprene FMDA11'', 300 parts by mass of number average molecular weight 1000) and 400 parts by mass of methyl ethyl ketone were injected, the temperature was raised to 85°C, and the mixture was kept warm for 7 hours to obtain a reaction product.

In a separate 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 reactant obtained above, and 286 parts by mass of methyl ethyl ketone were injected, and the temperature was raised to 85° C. for 7 hours. It kept warm and made it react, it confirmed by IR measurement that an isocyanate group disappeared, and the active energy ray-curable release agent compound (A9) was obtained.

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

[Example 1]

100 parts by mass of active energy ray-curable component (A1) and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propy) as α-hydroxyketone-based photopolymerization initiator (B1) O'Nyl)-benzyl]-phenyl}-2-methyl-propan-1-one (manufactured by BASF, product name "IRGACURE127") 5 parts by mass using a mixed solvent of isopropyl alcohol and methyl ethyl ketone (mass ratio 3: 1) It diluted to a solid content concentration of 20% by mass to obtain a material for forming a release agent layer.

The obtained material for forming a release agent layer was a biaxially stretched polyethylene terephthalate (PET) film as a base material (thickness: 31 µm, arithmetic mean roughness (Ra0) of the first surface: 16 nm, maximum protrusion height (Rp0) of the first surface): 196 nm, arithmetic mean roughness of the second surface (Ra2): 16 nm, the maximum protrusion height of the second surface (Rp2): 196 nm) is coated with a bar coater so that the thickness after curing becomes 1 μm. And dried at 80° C. for 1 minute. Thereafter, ultraviolet rays were irradiated (accumulated light amount: 250 mJ/cm 2) to cure the material for forming a release agent layer to form a release agent layer, which was used as a release film. In addition, the thickness of the release agent layer is the result of measurement by the measurement method mentioned later (the following examples etc. are also 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 mixed instead 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 mixed instead 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 mixed instead 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 mixed instead 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]

Except having changed the thickness of a release agent layer to 1.9 micrometers, it carried out similarly to Example 1, and produced the release film.

[Example 8]

In place of the photoinitiator (B1), 2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropan-1-one (manufactured by BASF) as an α-aminoalkylphenone-based photoinitiator (B2) , The product name "IRGACURE907") was carried out in the same manner as in Example 1 to produce a release film.

[Example 9]

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

[Example 10]

In place of the substrate in Example 1, a biaxially stretched PET film (thickness 38 µm, arithmetic mean roughness (Ra0) of the first surface: 35 nm, maximum protrusion height (Rp0) of the first surface: 471 nm, 2nd A peeling film was produced in the same manner as in Example 1, except that the arithmetic mean roughness of the surface (Ra2): 35 nm, and the maximum protrusion height of the second surface (Rp2): 471 nm) 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 mixed instead 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 mixed instead 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 mixed instead 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 mixed instead 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 Industries, 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 a ketone photopolymerization initiator (B1) 5 parts by mass of ON (manufactured by BASF, product name "IRGACURE127") was diluted to a solid content concentration of 20% by mass with a mixed solvent of isopropyl alcohol and methyl ethyl ketone (mass ratio 3: 1) to obtain a material for forming a release agent layer. Using this material for forming a release agent layer, a release film was produced 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 substrate in Example 1, a biaxially stretched PET film (thickness 38 μm, arithmetic mean roughness (Ra0) of the first surface: 42 nm, maximum protrusion height (Rp0) of the first surface: 619 nm, second A peeling film was produced in the same manner as in Example 1, except that the arithmetic mean roughness of the surface (Ra2): 42 nm and the maximum protrusion height 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 mean roughness (Ra0) on the first surface: 15 nm, maximum protrusion height (Rp0) on the first surface: 105 nm, second A release film was produced in the same manner as in Example 1, except that the arithmetic mean roughness of the surface (Ra2): 3 nm and the maximum protrusion height of the second surface (Rp2): 15 nm) were used.

[Test Example 1] (Measurement of the thickness of the release agent layer)

The thickness (µm) of the release agent layer of the release film obtained in Examples and Comparative Examples was measured using a reflective film thickness meter (manufactured by Philmetrics, product name "F20"). Specifically, after cutting the release film obtained in Examples and Comparative Examples into 100 mm x 100 mm, a release film was installed on the film thickness gauge so that the opposite surface of the surface to be measured becomes the suction stage side, and the surface of the release agent layer The film thickness was measured at 10 locations of, and the average value was taken as the thickness of the release agent layer. Table 2 shows the results.

[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 Examples and Comparative Examples were fixed to the glass plate through the double-sided tape so that the opposite side of the side to be measured was on the glass plate side. The arithmetic mean roughness (Ra1; nm) and the maximum protrusion height (Rp1; nm) on the surface of the release agent layer of the release film (the exposed surface; the same hereinafter) were measured using a surface roughness measuring instrument (manufactured by Mitsutoyo, product name " SV-3000S4", stylus type) was used, and it measured according to JIS B 0601-1994. Table 2 shows the results.

[Test Example 3] (Silicon transferability evaluation)

20% by mass of a polyvinyl butyral resin (manufactured by Sekisui Chemical Co., Ltd., product name "S-LEC BK BL-S", in powder form) with a mixed solvent of toluene and ethanol (mass ratio 50:50) It melt|dissolved in and obtained the polyvinyl butyral resin solution. The obtained polyvinyl butyral resin solution was applied to the surface of the release agent layer of the release films obtained in Examples and Comparative Examples with a bar coater so that the thickness after drying became 4 µm, and dried to form a polyvinyl butyral resin layer.

The polyvinyl butyral resin layer was peeled off from the release film, and the silicon atom measured by X-ray photoelectron spectroscopy (XPS) with respect to the surface in contact with the surface of the release agent layer in the polyvinyl butyral resin layer ( Based on the amount of Si), carbon atom (C), and oxygen atom (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

And the silicon migration property was evaluated based on the following judgment criteria. Table 3 shows the results.

A… Silicon atomic ratio is less than 0.3 atomic%

B… Silicon atom ratio is 0.3 atomic% or more, less than 1.0 atomic%

C… The silicon atom ratio is 1.0 atomic% or more

[Test Example 4] (Evaluation of the coated surface of the release agent layer)

With respect to the release films obtained in Examples and Comparative Examples, the state of the coated surface (surface) of the release agent layer was visually observed, and the coated surface of the release agent layer was evaluated according to the following criteria. Table 3 shows the results.

A… There was no surface abnormality due to the potter's stem shape.

B… There were some abnormalities on the surface due to the pottery stem shape, but there was no problem in use.

C… A coating stem-shaped trace occurred on the entire coating surface, or an extreme surface abnormality occurred.

[Test Example 5] (Evaluation of curability of release agent layer)

For the release films obtained in Examples and Comparative Examples, the surface of the release agent layer was polished 10 times by reciprocating at a load of 1 kg/cm 2 with a waste containing methyl ethyl ketone (manufactured by Oz Industries, product name "BEMCOT AP-2"). . Then, 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 the case where the evaluation was "C" in this test (Test Example 5), since a sample satisfactory for performing other tests could not be obtained, other tests were not performed. Table 3 shows the results.

A… There was no dissolution or detachment of the release agent layer.

B… Partial dissolution of the release agent layer was observed.

C… The release agent layer was completely dissolved and fell out of the substrate.

[Test Example 6] (Slurry coating property evaluation)

100 parts by mass of barium titanate powder (BaTiO ₃ ; manufactured by Sakai Chemical Industries, product name "BT-03"), polyvinyl butyral resin as a binder (manufactured by Sekisui Chemical Industries, product name "Srec BK BM-2") 8 135 parts by mass of a mixture of toluene and ethanol (mass ratio 6: 4) to 4 parts by mass of dioctyl phthalate (manufactured by Kanto Chemical Co., Ltd., dioctyl phthalate (CICA) 1st grade) as a plasticizer, and viewed in the presence of zirconia beads. The mixture was mixed with a mill and dispersed, and 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 coated over a width of 250 mm and a length of 10 m so that the film thickness after drying by a die coater became 1 µm, and then 80 with a dryer. It was dried at °C for 1 minute. With respect to the release film on which the ceramic green sheet was formed, a fluorescent lamp was illuminated from the release film side, and all the formed ceramic green sheet surfaces were visually inspected, and the slurry coatability was evaluated according to the following criteria. Table 3 shows the results.

A… There were no pinholes in the ceramic green sheet.

B… One to five pinholes were generated in the ceramic green sheet.

C… Six or more pinholes were generated in the ceramic green sheet.

[Test Example 7] (Evaluation of ceramic green sheet peelability)

In the same procedure as in Test Example 6, the ceramic green sheet formed on the surface of the release agent layer of the release film was punched out at 200 mm x 200 mm so that the release film was not punched out. Next, using the sheet peeling mechanism of the green sheet laminating machine, the punched green sheet was adsorbed on the vacuum suction stage, and peeled from the peeling film. The peelability from the ceramic green sheet at this time was evaluated according to the following judgment criteria. Table 3 shows the results.

A… The ceramic green sheet was not torn, it could be peeled off smoothly, and the ceramic green sheet did not remain on the peeling agent layer.

B… The ceramic green sheet was not torn, and although a little smoothness was insufficient, it could be peeled off, and the ceramic green sheet was not left on the release agent layer.

C… The ceramic green sheet was torn or could not be peeled off.

[Test Example 8] (Evaluation of defects of ceramic green sheet by the surface of the release agent layer)

Polyvinyl butyral resin (manufactured by Sekisui Chemical Co., Ltd., product name "Srec BK BL-S", in powder form) was dissolved in a solid content concentration of 20% by mass with a mixed solvent of toluene and ethanol (mass ratio 60:40), A vinyl butyral resin solution was obtained. The obtained polyvinyl butyral resin solution was applied onto the release agent layer of the release films obtained in Examples and Comparative Examples so that the thickness after drying was 3 µm, and dried at 80° C. for 1 minute to form a polyvinyl butyral resin layer. Then, a polyester adhesive tape was affixed to the surface of the polyvinyl butyral resin layer.

Subsequently, the release film was peeled off from the polyvinyl butyral resin layer, and the polyvinyl butyral resin layer was transferred to a polyester adhesive tape. Thereafter, the number of concave portions on the surface of the polyvinyl butyral resin layer in contact with the surface of the release agent layer was counted. Specifically, the surface shape image in the range of 91.2 μm×119.8 μm obtained by observing at 50 magnification in PSI mode using an optical interference type surface shape observation device (manufactured by Vecco, product name “WYKO-1100”) Based on this, the number of concave portions having a depth of 150 nm or more was counted.

Based on the number of concave portions, defects of the ceramic green sheet due to the surface of the release agent layer were evaluated according to the following criteria. In addition, in the above-described ceramic green sheet peelability evaluation test (Test Example 7), for those whose evaluation was "C", this test was not performed because a satisfactory sample could not be obtained for carrying out this test. . Table 3 shows the results.

A… 0 number of recesses

B… The number of recesses is 1-5

C… 6 or more recesses

In addition, when a capacitor is manufactured from a ceramic green sheet in which the concave portion of the evaluation C is present, the obtained capacitor tends to cause a short circuit due to a decrease in withstand voltage.

[Test Example 9] (Evaluation of defects of ceramic green sheet by the second surface of the substrate)

A polyvinyl butyral resin (manufactured by Sekisui Chemical Co., Ltd., product name "Srec BK BL-S", in powder form) was dissolved in a solid content concentration of 20% by mass with a mixed solvent of toluene and ethanol (mass ratio 60:40), 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 became 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 side of the substrate in the release film was in contact with the polyvinyl butyral resin layer. After cutting this laminate into 100 mm×100 mm, it was pressed with a load of 5 kg/cm 2, and the protrusion shape of the second surface of the substrate in the release film was transferred to the polyvinyl butyral resin layer.

Subsequently, the release film is peeled from the polyvinyl butyral resin layer, and the depth of the concave portion on the surface of the polyvinyl butyral resin film in contact with the second surface of the substrate of the release film is measured, and the concave portion Counted. Specifically, using an optical interference type surface shape observation device (manufactured by Vecco, WYKO-1100) was observed at 50 magnification in PSI mode, and concave based on the obtained surface shape image in the range of 91.2 µm x 119.8 µm. Along with measuring the depth of the part, the number of recesses was counted.

Based on the depth and number of the concave portions, defects of the ceramic green sheet due to the second surface of the substrate were evaluated according to the following criteria. Table 3 shows the results.

A… 0 number of recesses with a depth of 300 nm or more

B… The number of recesses with a depth of 500 nm or more is 0, and the number of recesses with a depth of 300 nm or more and less than 500 nm is 1 or more

C… The number of recesses with a depth of 500 nm or more is 1 or more

In addition, when a capacitor is manufactured from a ceramic green sheet in which the concave portion of the evaluation C is present, the obtained capacitor tends to cause a short circuit due to a decrease in withstand voltage.

[Test Example 10] (Evaluation of handling properties)

The peeling films obtained in Examples and Comparative Examples were evaluated for handling properties when making them into a roll shape. Specifically, the sliding properties between the contacted release films, good air leakage when forming a roll shape, and the difficulty in occurrence of unwinding of the release film were evaluated according to the following judgment criteria. Table 3 shows the results.

A… The sliding properties between the contacted release films were good, and the air leakage when making the release film into a roll shape was good, and the winding deviation of the release film was able to be prevented.

B… The sliding properties between the contacted release films were slightly bad, and the air leakage when the release films were wound in a roll shape was slightly bad, and winding deviation occurred slightly, but there was no problem.

C… The slipping property between the peeling films in contact was poor, and the air leakage when the peeling film was wound in a roll shape was bad, and the winding misalignment occurred remarkably.

[Test Example 11] (Evaluation of blocking property)

The release films obtained in Examples and Comparative Examples were wound into a roll shape 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, and the appearance as it was in the state of the release film roll was visually observed, and the blocking property was evaluated according to the following judgment criteria. Table 3 shows the results.

A… There was no change from the time of winding in a roll shape (no blocking).

B… In less than half of the area in the width direction, a change in color due to close adhesion between the films was observed (there is some blocking, but it can be used).

C… Over a majority of the area in the width direction, a change in color due to adhesion between the films was seen (blocking)

As is clear from Table 3, the peeling film of the example was excellent in peelability from the ceramic green sheet, and the silicon-based compound (a peeling imparting component) was difficult to transfer to the ceramic green sheet. Further, according to the release film of the example, defects were less likely to occur in the ceramic green sheet, furthermore, blocking was less likely to occur, and handling properties were also good.

One … Release film for ceramic green sheet manufacturing process
11… materials
111 ... First side
112… 2nd side
12… Release agent layer
121 ... surface

Claims (3)

A release film for a ceramic green sheet manufacturing process comprising a base material having a first side and a second side, and a release agent layer formed on the first side of the base material,
The release agent layer is formed of a release agent composition containing an active energy ray-curable component (A) and a photopolymerization initiator (B),
The active energy ray-curable component (A),
A hydroxyl group-containing (meth)acrylate (a1) having at least three (meth)acryloyl groups on average per molecule, and
Polyvalent isocyanate compound (a2),
Linear dimethylorganopolysiloxane (a3) having at least one hydroxyl group in one molecule and having a mass average molecular weight of 500 to 8000,
Reaction so that the amount of the dimethyl organopolysiloxane (a3) with respect to the total amount of the (meth)acrylate (a1), the polyvalent isocyanate compound (a2) and the dimethyl organopolysiloxane (a3) is 0.01 to 0.10 by mass ratio Done,
The thickness of the release agent layer is 0.3 to 2 μm,
The arithmetic mean roughness (Ra1) on the side opposite to the substrate of the release agent layer is 8 nm or less, and the maximum protrusion height (Rp1) is 50 nm or less,
A release film 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. The release film for a ceramic green sheet manufacturing process according to claim 1, wherein the photoinitiator (B) is an α-hydroxyketone compound or an α-aminoalkylphenone compound. The method according to claim 1 or 2, wherein after forming a polyvinyl butyral resin layer on a surface of the release agent layer opposite to the substrate, when the polyvinyl butyral resin layer is peeled from the release agent layer, the A release film for a ceramic green sheet manufacturing process, wherein a silicon atom ratio as measured by photoelectron spectroscopy is less than 1.0 atomic% with respect to the surface of the polyvinyl butyral resin layer in contact with the release agent layer.

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