TW201437025A - Release film - Google Patents

Abstract

A release film of the invention includes a base and a release agent layer. The release agent layer is formed by irradiating a coating layer with an active energy ray and curing it. The coating layer is formed by applying a release agent layer formation material to a first surface of the base. The release agent layer formation material contains active energy ray curable compounds (A) and (B). The active energy ray curable compound (A) has at least a reactive functional group selected from the group consisting of a (metha)acryloyl group, an alkenyl group and a maleimide group and no fluorine atom in a molecule thereof. The active energy ray curable compound (B) has at least a reactive functional group selected from the group consisting of a (metha)acryloyl group, an alkenyl group and a maleimide group and fluorine atoms in a molecule thereof. An average roughness of an outer surface of the release agent layer is 8 nm or less and a roughness of maximum profile peak height of the outer surface is 50 nm or lower. An average roughness of a second surface of the base is in the range of 5 to 40 nm and a roughness of maximum profile peak height of the second surface is in the range of 60 to 500 nm or lower.

Description

Release film

This invention relates to a release film.

In the manufacture of a stacked ceramic capacitor, a release film is used in order to form a green sheet.

In general, the release film is composed of a substrate and a release agent layer. A ceramic slurry in which ceramic particles and a binder resin are dispersed and dissolved in an organic solvent is applied to such a release film to obtain a coating, and a green sheet is produced by drying it. By such a method, a green sheet of uniform thickness can be efficiently produced. Next, the green sheet thus produced is peeled off from the release film and used for the manufacture of stacked ceramic capacitors.

In the manufacture of the green sheet as described above, the release film in which the green sheet has been formed is generally wound into a roll shape for storage or transportation.

However, it is known that in the release film as described above, the surface roughness (average roughness) of the opposite surface (back surface) of the surface of the substrate on which the release agent layer is provided is increased to attempt to eliminate the release film. And a problem of a problem such as sticking to the surface in contact with the curled release film (for example, see Patent Document 1, Japanese Patent Laid-Open Publication No. 2003-203822).

However, in the case of using the release film described in Patent Document 1, When the release film that has formed the green sheet is wound to be stored, the rough surface shape of the back surface of the release film is transferred to the green sheet, so that the green sheet is locally thinned. When a green sheet is stacked to form a capacitor, there is a case where a failure due to a short circuit occurs.

On the other hand, if the surface roughness (average roughness) of the opposite surface of the substrate on which the surface of the release agent layer is disposed is lowered, the surface roughness becomes relatively flat, and the surface of the surface where the release films contact each other Poor sliding may cause problems such as poor winding or agglomeration.

SUMMARY OF THE INVENTION An object of the present invention is to provide a release film having excellent mold release property and blocking resistance, which can prevent pinholes or partial thickness unevenness of a film when forming a film such as a green sheet.

The object is achieved by the present invention of (1) to (5) below.

(1) A release film comprising a substrate and a release agent layer. The substrate has a first surface and a second surface. The release agent layer is formed by irradiating a coating layer with an active energy ray and hardening. The coating layer is formed by applying a material for forming a release agent layer containing one active energy ray-curable compound (A) and one active energy ray-curable compound (B) to the first surface of the substrate. The active energy ray-curable compound (A) has at least one selected from the group consisting of a (meth)acryloyl group, an alkenyl group, and a maleimide group. One of the reactive functional groups does not have a fluorine atom in the molecule. Active energy ray hardening compound (B) has an option One of at least one of the group consisting of a (meth) acryl fluorenyl group, an alkenyl group, and a maleidino group has a reactive functional group and has a fluorine atom in the molecule. The arithmetic mean roughness Ra1 of the outer surface of one of the release agent layers is 8 nm or less, and the maximum protrusion height Rp1 of the outer surface of the release agent layer is 50 nm or less. The arithmetic mean roughness Ra2 of the second surface of the substrate is 5 to 40 nm, and the maximum protrusion height Rp2 of the second surface of the substrate is 60 to 500 nm.

(2) The release film according to the above (1), wherein the active energy ray-curable compound (B) has a poly(perfluoroalkylene ether) chain in a molecule.

(3) The release film according to the above (1) or (2), wherein the active energy ray-curable compound (B) is 0.1 to 5 in terms of solid content in the material for forming the release agent layer. Percentage of mass.

(4) The release film according to any one of (1) to (3) above, wherein the one of the release agent layers has an average film thickness of 0.3 to 2 μm.

(5) The release film according to any one of the above (1) to (4), which is used for the production of a green sheet.

For example, the present invention can provide a release film having excellent mold release property and blocking resistance, which can prevent pinholes or partial thickness unevenness of the film when forming a film such as a green sheet.

1‧‧‧Fractal film

11‧‧‧Substrate

111‧‧‧The first surface of the substrate

112‧‧‧Second surface of the substrate

12‧‧‧ release agent layer

121‧‧‧Outer surface of the release agent layer

Figure 1 is a side cross-sectional view showing the release film of the present invention.

The invention will be described in detail below with reference to preferred embodiments.

The release film will be described below.

The release film of the present invention is used, for example, for the production of a film such as a green sheet. Further, the release film of the present invention is used for the production of a green sheet, and particularly exerts a high effect.

Fig. 1 is a side sectional view showing the release film 1 of the present invention.

As shown in Fig. 1, the release film 1 has a substrate 11 and a release agent layer 12. The substrate 11 has a first surface 111 and a second surface 112. The release agent layer 12 is disposed on the first surface 111 of the substrate 11.

The release film 1 of the present invention has the following feature points: a substrate 11 having an arithmetic mean roughness Ra2 of the second surface 112 of 5 to 40 nm and a maximum protrusion height Rp2 of 60 to 500 nm, and a release having a specified composition The release agent layer 12 formed of the material for forming a layer of the agent layer has an arithmetic mean roughness Ra1 of the outer surface 121 of the release agent layer 12 of 8 nm or less and a maximum protrusion height Rp1 of 50 nm or less.

By making the outer surface 121 of the release agent layer 12 more highly smooth than the second surface 112 of the substrate 11, a green sheet (film formed by the protrusion of the outer surface 121 of the release agent layer 12 is formed). The depression of the green sheet is partially coincident with the depression of the green sheet (film) formed by the protrusion of the second surface 112 of the substrate 11, and pinholes can be prevented from being generated in the green sheet.

By using the release film 1 of the present invention having such characteristics, It is possible to prevent pinholes or partial thickness unevenness from occurring in the green sheet (film). As a result, a green sheet (film) of high reliability can be formed.

In particular, even if the thickness of the green sheet is extremely thin (for example, the thickness is 5 μm or less, particularly the thickness is 0.5 μm to 2 μm), a good green sheet (film) having no such defects can be formed. Further, while the outer surface 121 of the highly smooth release agent layer 12 is obtained, the release film 1 can also have excellent release properties.

Hereinafter, each layer constituting the release film 1 of the present embodiment will be described in detail.

The substrate will be explained below.

The substrate 11 has a first surface 111 and a second surface 112.

The base material 11 has a function of imparting physical strength such as rigidity and flexibility to the release film 1 .

The substrate 11 is not particularly limited, and any material can be appropriately selected from previously known materials. For example, the substrate 11 may be a polyester such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), such as poly. A plastic film made of a polyolefin such as polypropylene (PP) or polymethylpentene (PMP) or a polycarbonate (Polycarbonate, PC) resin. The substrate 11 can be composed of a single layer, or can be composed of two or more layers of the same type or different types. Among these materials, the constituent material of the substrate 11 is preferably a polyester film, particularly polyethylene terephthalate, and more preferably a biaxially stretched polyethylene terephthalate film. . For example, such a plastic system The film material is less likely to generate dust during processing and during use, and can effectively prevent the ceramic slurry from being poorly coated due to dust.

As described above, the second surface 112 of the substrate 11 has an arithmetic mean roughness Ra2 of 5 to 40 nm. Therefore, when the release film 1 having the outer surface 121 of the release agent layer 12 is smoothly wound around a core material such as paper, plastic, or metal to form a roll, the air can be sufficiently removed, and the film can be effectively removed. Suppresses the situation of curl slip. Therefore, it is possible to suppress deformation of the core portion due to the tension of the winding without increasing the tension of the winding. Further, it is possible to prevent agglomeration of the surfaces of the release film 1 which has been wound into a roll shape in contact with each other. Furthermore, when the release film 1 in which the green sheet (film) has been formed is wound, it is possible to prevent the surface shape of the second surface 112 of the substrate 11 which is in contact with the green sheet (film) from being transferred to the surface shape. The green sheet (film) can prevent pinholes or partial thickness unevenness of the green sheet (film). As a result, a green sheet (film) of high reliability can be manufactured.

On the other hand, when the arithmetic mean roughness Ra2 does not reach the aforementioned lower limit value, when the release film 1 before the formation of the green sheet is stored, when the release film 1 before the formation of the green sheet is wound, the air is easily caught. , and it is prone to curling and slipping. Therefore, the access of the release film 1 becomes difficult. Further, the surface and the back surface of the curled release film 1 (the second surface 112 of the substrate 11 and the release agent layer 12) adhere to each other, and it is difficult to sufficiently prevent the agglomeration. On the other hand, if the arithmetic mean roughness Ra2 exceeds the above upper limit value, when the release film 1 after the green sheet is formed, the protrusion shape of the second surface 112 of the substrate 11 which is in contact with the green sheet will Transfer to a green sheet. Therefore, it may be difficult to maintain sufficient pinholes or partial thickness unevenness in the green sheets. The smoothness of the green sheet.

Further, although the arithmetic average roughness Ra2 of the second surface 112 of the substrate 11 is 5 to 40 nm, it is particularly preferably 10 to 30 nm. Thereby, the above effects become particularly remarkable.

Further, the maximum protrusion height Rp2 of the second surface 112 of the substrate 11 is 60 to 500 nm. Therefore, when the release film 1 having the outer surface 121 of the release agent layer 12 is smoothly wound around a core material such as paper, plastic, or metal to form a roll, the air can be sufficiently removed, and the film can be effectively removed. Suppresses the situation of curl slip. Therefore, it is possible to suppress deformation of the core portion due to the tension of the winding without increasing the tension of the winding. Further, when the roll-shaped release film 1 is unrolled, it is possible to prevent agglomeration of the surfaces of the release film 1 which has been wound into a roll shape. Moreover, when the release film 1 in which the green sheet has been formed is wound for storage, the surface shape of the second surface 112 of the substrate 11 in contact with the green sheet can be prevented from being transferred to the green sheet, and Prevent pinholes or partial thickness unevenness of the green sheets. As a result, a green sheet of high reliability can be manufactured.

On the other hand, when the maximum protrusion height Rp2 does not reach the aforementioned lower limit value, when the release film 1 before the formation of the green sheet (film) is stored, the air is easily removed when the release film 1 is formed before the green sheet is formed. Entangled, and prone to curl slip. Therefore, the access of the release film 1 becomes difficult. Further, the second surface 112 of the substrate 11 which is in contact with the release of the release film 1 and the outer surface 121 of the release agent layer 12 adhere to each other, and it is difficult to sufficiently prevent the agglomeration. On the other hand, if the maximum protrusion height Rp2 exceeds the above upper limit value, when the green sheet 1 after the formation of the green sheet is wound, the green sheet is formed The shape of the protrusion of the second surface 112 of the substrate 11 that is in contact with is transferred to the green sheet. Therefore, there is a fear that pinholes or partial thickness unevenness may occur in the green sheet, and it is difficult to sufficiently maintain the smoothness of the green sheet.

The maximum protrusion height Rp2 on the second surface 112 of the substrate 11 is 60 to 500 nm, preferably 80 to 400 nm, and particularly preferably 100 to 300 nm. Thereby, the above effects become particularly remarkable.

The arithmetic mean roughness Ra ₀ of the first surface 111 of the substrate 11 is preferably 2 to 80 nm, more preferably 5 to 50 nm. As will be described later, since the release agent layer 12 which is smoothed in the uneven state of the first surface 111 is formed on the first surface 111 of the substrate 11, if the arithmetic mean roughness Ra ₀ falls within the above range, smoothing The effect will become particularly significant.

Further, the maximum protrusion height Rp ₀ of the first surface 111 of the substrate 11 is preferably 10 to 700 nm, more preferably 20 to 500 nm. As will be described later, since the release agent layer 12 which is smoothed by the uneven state of the first surface 111 is formed on the first surface 111 of the substrate 11, if the maximum protrusion height Rp ₀ falls within the above range, the smoothing action is performed. Will become especially noticeable.

The average film thickness of the substrate 11 is not particularly limited, but is preferably 10 to 300 μm, and more preferably 15 to 200 μm. Thereby, the release film 1 can maintain moderate flexibility while also having particularly excellent resistance to tearing and breaking.

The release agent layer will be described below.

The release agent layer 12 is disposed on the first surface 111 of the substrate 11.

The release agent layer 12 has a function of imparting a release property to the release film 1.

The release agent layer 12 is a layered product formed by irradiating an active energy ray with a material for forming a release agent layer containing a predetermined component, and then curing.

The material for forming a release agent layer contains an active energy ray-curable compound (A) and an active energy ray-curable compound (B). The active energy ray-curable compound (A) has at least one selected from the group consisting of a (meth)acryloyl group, an alkenyl group, and a maleimide group. One of the reactive functional groups does not have a fluorine atom in the molecule. The active energy ray-curable compound (B) has one reactive functional group selected from the group consisting of a (meth) acryl fluorenyl group, an alkenyl group and a maleidino group, and has a fluorine in the molecule. atom. By using such a material for forming a release agent layer, the hardenability at the time of formation of the release agent layer 12 and the release property to the green sheet can be particularly excellent. Further, it is possible to improve the film formability on the substrate 11, and when forming a film such as a green sheet, it is possible to more effectively prevent pinholes or partial thickness unevenness from occurring in the film.

Hereinafter, each component will be described in detail.

The active energy ray curable compound (A) will be explained below.

The active energy ray-curable compound (A) is a component that contributes to the formation of the release agent layer 12 by hardening. Thereby, the release agent layer 12 can have a more moderate mechanical strength.

The active energy ray-curable compound (A) has a reactive functional group selected from at least one of the group consisting of a (meth) acryl fluorenyl group, an alkenyl group and a maleidino group, and has no intramolecular Fluorine atom. Wherein the above alkenyl group is, for example, a vinyl group, an allyl group, a propenyl group, or a hexenyl group. The number of carbon atoms is 2 to 10 alkenyl groups. The active energy ray-curable compound (A) is preferably one or more of the above-mentioned reactive functional groups in one molecule, and preferably three or more in one molecule. Thereby, the release agent layer 12 can obtain excellent hardenability, solvent resistance, and release property. Further, such an active energy ray-curable compound (A) has moderate fluidity and shape retention. Therefore, when the material for forming a release agent layer containing such an active energy ray-curable compound (A) is applied onto the first surface 111 of the substrate 11, it can be surely filled in by the material for forming the release agent layer. The first surface 111 of the substrate 11 has an uneven state, and can be surely maintained in this filled state. As a result, the outer surface 121 of the release agent layer 12 can be made smooth.

In addition, the content of the reactive functional group in the active energy ray-curable compound (A) is preferably 10 equivalents or more per 1 kg of the active energy ray-curable compound (A). Thereby, even in the case where the film is applied to the first surface 111 of the substrate 11, the curability of the active energy ray-curable compound (A) can be particularly optimized.

As the active energy ray curable compound (A), the reactive functional group is preferably a (meth) acrylonitrile group. Specifically, it may be dipentaerythritol tri(metha)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate Dipentaerythritol penta (metha) acrylate, dipentaerythritol hexa (metha) acrylate, pentaerythritol tri(meth) acrylate (pentaerythritol tri(metha)acrylate) and pentaerythritol tetra(meth)acrylate and the like (meth) acrylate. Wherein, at least one selected from the group consisting of dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, pentaerythritol triacrylate, and pentaerythritol tetraacrylate is used. Multifunctional acrylates are preferred. Thereby, even in the case where the film is applied to the first surface 111 of the substrate 11, the curability of the active energy ray-curable compound (A) can be particularly optimized.

Among the materials for forming the release agent layer, the content of the active energy ray-curable compound (A) in terms of the solid content (the content ratio in the total solid content of the solvent to be removed) is preferably 65 to 98.5 by mass, and 71. A mass percentage of ~96.3 is preferred.

The active energy ray curable compound (B) will be described below.

The active energy ray-curable compound (B) is a component which is found to be inferior in the release agent layer 12.

The active energy ray-curable compound (B) has a reactive functional group selected from at least one of the group consisting of a (meth) acryl fluorenyl group, an alkenyl group, and a maleimine group, and has a fluorine in the molecule. atom. The alkenyl group is, for example, an alkenyl group having 2 to 10 carbon atoms such as a vinyl group, an allyl group, a propenyl group, or a hexenyl group. Further, in the active energy ray-curable compound (B), the reactive functional group is preferably a (meth) acrylonitrile group.

For example, the active energy ray hardening compound (B) is Having at least one of a group consisting of a (poly)alkylene ether) chain (b1) and selected from the group consisting of a (meth) propylene group, an alkenyl group and a maleimine group The reactive functional group is preferably a compound which directly or indirectly has a divalent linking group and is bonded to the terminal and/or side chain of the molecular chain. Among them, the compound preferably has at least one of the above-mentioned reactive functional groups in one molecule.

Specifically, the poly(perfluoroalkylene ether) chain has a molecular chain having a structure in which a divalent fluorinated carbon group having 1 to 3 carbon atoms and an oxygen atom are linked to each other. The divalent fluorinated carbon group having 1 to 3 carbon atoms may be one type or a mixture of a plurality of types. Specifically, the poly(perfluoroalkylene ether) chain is represented by the following structural formula (1)

(In the above structural formula (1), X is the following structures (a) to (d). All of X in the structural formula (1) may have the same structure. Alternatively, the structures may be different from each other. (random) or block form exists in the structural formula (1). Further, n is one or more of the number of repeated units.)

Chemical formula 2:

Further, for example, the aforementioned divalent linking group may be an alkylene group, an alkyleneoxy group, an oxy group, an imino group, a carbonyl group, a combination thereof, or the like. A divalent linking group. The number of carbon atoms of the divalent linking group is preferably from 1 to 30, preferably from 1 to 10.

Further, two or more kinds of active energy ray-curable compounds (B) can be used in combination as needed.

Furthermore, the active energy ray-curable compound (B) may have at least one selected from the group consisting of a hydroxyl group, an isocyanate group, a glycidyl group, and a carboxyl group. Functional group.

Further, the active energy ray-curable compound (B) may have a constituent unit derived from a monomer (b2) at a terminal and/or a side chain of a molecular chain thereof, the monomer having a hydroxyl group selected from the group consisting of a hydroxyl group and an isocyanate. a functional group of at least one of the group consisting of (isocyanate) a group, a glycidyl group, and a carboxyl group.

For example, having a hydroxyl group, an isocyanate a monomer having a functional group of at least one of a group consisting of (isocyanate), glycidyl and carboxyl, which may be 2-hydroxyethyl (meth) acrylate (2- Hydroxyethyl (metha) acrylate), 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (metha) acrylate, 1,4-cyclohexane dimethanol 1,4-cyclohexanedimethanol mono(metha)acrylate, N-(2-hydroxyethyl)(meth)acrylamide, C Glycerol mono(meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate (polypropylene) Glycol mono(metha)acrylate), 2-hydroxy-3-phenoxypropyl(meth)acrylate and 2-(meth)acryloyloxyethyl- 2-hydroxyethyl phthalate (2-(meth a) hydroxy-containing unsaturated monomer such as acryloyloxyethyl-2-hydroxyethylphthalate); 2-(meth)acryloyloxyethyl isocyanate and 2-(meth) propylene oxime Isocyanate-containing unsaturated monomer such as 2-(2-(meth)acryloyloxyethoxy)ethyl isocyanate); glycidyl methacrylate and 4-hydroxybutyl acrylate epoxypropyl Epoxypropyl unsaturated monomer such as 4-hydroxy butyl acrylate glycidyl ether; (methyl) Acrylic acid 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxyethyl phthalic acid And a carboxyl group-containing unsaturated monomer such as itaconic acid (methylene succinic acid).

Further, the active energy ray-curable compound (B) may have a constituent unit (b3) derived from another unsaturated monomer at the terminal and/or side chain of the molecular chain.

Other unsaturated monomers may be methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate (n-butyl) Methacrylate), isobutyl methacrylate, n-pentyl methacrylate, n-hexyl methacrylate, n-heptyl methacrylate ), n-octyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, decyl methacrylate , methacrylic acid esters such as dodecyl methacrylate, cyclohexyl methacrylate, and isobornyl methacrylate; methyl acrylate ( Methyl acrylate), ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate N-amyl acrylate, (n-pentyl acrylate), n-hexyl acrylate, n-heptyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate Acrylates, acrylates such as nonyl acrylate, decyl acrylate, dodecyl acrylate, cyclohexyl acrylate, and isobornyl acrylate ( Acrylic acid esters; styrene, α-methyl styrene, p-methyl styrene, and p-methoxy styrene Aromatic vinyl (vinyl) and other materials.

Further, first, one of at least one selected from the group consisting of a (meth)acryloyl group, an alkenyl group, and a maleimide group is reactive. The active energy ray-curable compound (B) is introduced into the group to synthesize a compound having a poly(perfluoroalkylene ether) chain (b1) and a constituent unit (b2). Next, it may be the following method: having a functional group and reactivity present in the compound, and having a composition selected from the group consisting of a hydroxyl group, an isocyanate group, a glycidyl group, and a carboxyl group. a functional group of at least one of the group and a group selected from the group consisting of a (meth)acryloyl group, an alkenyl group, and a maleimide group At least one of the reactive functional group compounds (b4) is reacted with this compound.

Specifically, such a compound (b4) may be 2-hydroxy-3-acryloyloxypropyl propyl (2-hydroxy-3-acryloyloxy propyl) Methacrylate), pentaerythritol triacrylate, dipentaerythritol penta acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate , 3-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, 1,4-cyclohexane 1,4-cyclohexanedimethanol mono acrylate, N-(2-hydroxyethyl)acrylamide, 2-acryloyloxy ethyl isocyanate Isocyanate), 4-hydroxybutyl acrylate glycidyl ether, and acrylic acid.

Further, the mass average molecular weight of the active energy ray-curable compound (B) measured by the GPC method is preferably from 300 to 30,000, more preferably from 1,500 to 10,000.

When the active energy ray-curable compound (A) is cured by irradiation with an active energy ray, the active energy ray-curable compound (B) is incorporated and fixed to the cured product of the active energy ray-curable compound (A). Joint structure. Thereby, it is possible to suppress the active energy ray-curable compound (B) which is a component of the release agent layer 12 from being transferred and transferred to the green sheet formed at the outer surface 121 of the release agent layer 12.

Among the materials for forming a release agent layer, the active energy ray-curable compound (B) is preferably used in an amount of 0.1 to 5 by mass based on the solid content. It is preferably a mass percentage of 0.3 to 4.5. Thereby, since the ceramic slurry (film forming material) can be applied to the release film 1 without being bounced, the release property of the release film 1 can be particularly optimized.

On the other hand, if the content of the active energy ray-curable compound (B) in the material for forming a release agent layer is not more than the above lower limit, the formed release agent layer 12 may not be sufficiently exerted. Formality. On the other hand, if the content of the active energy ray-curable compound (B) in the material for forming a release agent layer is more than the above upper limit in terms of the solid content, the ceramic slurry is applied to the formed release agent layer. On the surface of 12, it is easy to bounce off the ceramic slurry. Further, the release agent layer 12 becomes difficult to be hardened, and there is a case where sufficient peeling property cannot be obtained.

Further, when the amount of the active energy ray-curable compound (A) is represented by A parts by mass, and the amount of the active energy ray-curable compound (B) is represented by B parts by mass, the B/A mass ratio is 0.1/99.9. The range of ~5/95 is preferred, and the range of 0.3/99.7~4.5/95.5 is particularly preferred. Thereby, the aforementioned effects can be made more remarkable.

Further, the release film 1 having the release agent layer 12 formed using the material for forming a release agent layer containing the active energy ray-curable compound (A) and the active energy ray-curable compound (B) is used. In the vicinity of the outer surface 121 of the release agent layer 12, a component derived from the active energy ray-curable compound (B) is segregated. The reason for such segregation is considered to have the following reasons. That is, the molecular structure and polarity of the active energy ray-curable compound (B) used in comparison with the active energy ray-curable compound (A) The molecular weight and the like are different, and during the application of the coating layer of the material for forming the release agent layer, the active energy ray-curable compound (B) is pushed down to the vicinity of the surface of the coating layer, and segregation occurs.

The photopolymerization initiator (C) will be explained below.

In the case where ultraviolet ray is used as the active energy ray in order to harden the material for forming the release agent layer, the material for forming the release agent layer may further contain a photopolymerization initiator (C). By using the photopolymerization initiator (C) and irradiation with ultraviolet rays, it is possible to more easily and reliably harden the material for forming a release agent layer.

The photopolymerization initiator (C) is not particularly limited, but may be, for example, a photopolymerization initiator using an α-aminoalkylphenone. Such an α-aminoalkyl acetophenone-based photopolymerization initiator becomes a compound which is hardly hindered by oxygen upon hardening. Therefore, even when the release film 1 is produced in an atmospheric environment, particularly excellent hardenability can be obtained.

For example, the α-aminoalkyl acetophenone photopolymerization initiator may be 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropane-1-one), 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)- 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1), 2-(dimethylamino)-2-((4-methylphenyl)methyl) 2-(4-(4-morpholinyl)phenyl]-1-butanone (2-(dimethylamino)-2-((4-methylphenyl)methyl)-1-(4-(4-morphlinyl)phenyl) A material such as -1-butaone), whereby particularly excellent hardenability, solvent resistance, and release property can be obtained.

Among the materials for forming a release agent layer, the photopolymerization initiator (C) is The content of the solid content is preferably from 1 to 20% by mass, preferably from 3 to 15% by mass. Thereby, even if the thickness of the release agent layer 12 falls within the thickness range in which it is difficult to obtain hardenability due to inhibition by oxygen, particularly excellent hardenability, solvent resistance, and release property can be obtained.

Further, the material for forming a release agent layer may contain other components in addition to the components described above. For example, other components such as a sensitizer, an antistatic agent, a hardener, and a reactive monomer may be contained.

For example, 2,4-diethyl thioxanthone and isopropyl thioxanthone can also be used as the sensitizer. Thereby, the reactivity can be further improved.

Among the materials for forming a release agent layer, the content of the other components described above in terms of solid content is preferably from 0 to 10% by mass.

The arithmetic mean roughness Ra ₁ of the outer surface 121 of the release agent layer 12 is 8 nm or less. Thereby, when the green sheet is formed at the outer surface 121 of the release agent layer 12, it is possible to more reliably prevent pinholes or partial thickness unevenness of the green sheet, and the surface of the green sheet can be made more highly smooth. .

The maximum protrusion height Rp ₁ of the outer surface 121 of the release agent layer 12 is 50 nm or less. Thereby, when the green sheet is formed at the outer surface 121 of the release agent layer 12, it is possible to more reliably prevent pinholes or partial thickness unevenness of the green sheet, and the surface of the green sheet can be made more highly smooth. .

The average thickness of the release agent layer 12 is preferably 0.3 to 2 μm, more preferably 0.5 to 1.5 μm. If the thickness of the release agent layer 12 does not reach the aforementioned lower limit, The smoothness of the outer surface 121 of the agent layer 12 may become insufficient. As a result, when the green sheet is formed at the outer surface 121 of the release agent layer 12, there is a fear that pinholes or partial thickness unevenness may occur in the green sheet. On the other hand, if the thickness of the release agent layer 12 exceeds the above upper limit value, warpage of the release film 1 due to hardening shrinkage of the release agent layer 12 tends to occur. Further, in the case where the release film 1 is wound, agglomeration tends to occur between the second surface 112 of the release film 1 which is in contact with the release agent layer 12. Therefore, there is a fear that the release film 1 is not wound properly, and the amount of static electricity may increase when the release film 1 is unwound.

The method of manufacturing the release film will be described below.

Next, a suitable embodiment regarding the manufacturing method of the release film 1 as described above will be explained.

The manufacturing method of this embodiment includes a first process for preparing the substrate 11, a second process for preparing a material for forming the release agent layer, and a third process. The third process is to apply a material for forming a release agent layer to the first surface 111 of the substrate 11, dry it to form a coating layer, and form a release agent by irradiating the coating layer with ultraviolet rays to harden it. Layer 12.

Hereinafter, each process will be described in detail.

The first process will be explained below.

First, the substrate 11 is prepared.

A surface treatment such as an oxidation method or the like can be performed on the first surface 111 of the substrate 11 or a primer treatment. Thereby, the adhesion between the substrate 11 and the release agent layer 12 provided on the first surface 111 of the substrate 11 can be particularly optimized.

Further, the oxidation method may be, for example, corona discharge treatment, plasma discharge treatment, chrome oxidation treatment (wet), flame treatment, hot air treatment, ozone treatment, ultraviolet irradiation treatment. Such a surface treatment method can be appropriately selected depending on the type of the substrate 11, and it is generally preferable to use a corona discharge treatment method from the viewpoint of effects and workability.

The second process will be described below.

Next, the active energy ray-curable compound (A), the active energy ray-curable compound (B), and other components are dissolved or dispersed in a solvent to obtain a material for forming a release agent layer.

The solvent may be methanol, ethanol, toluene, ethyl acetate, xylene, methyl ethyl ketone (MEK), methyl butyl ketone. (methyl butyl ketone, MBK) and isopropyl alcohol.

The third process will be described below.

Next, a material for forming a release agent layer is applied onto the first surface 111 of the substrate 11 and dried to obtain a coating layer. During the application to the material for forming the release agent layer, the material for forming a release agent layer is filled in the uneven state of the first surface 111 to form a smooth coating layer.

Thereafter, the coating layer thus obtained is irradiated with an active energy ray to harden the coating layer, thereby forming a smoothed release agent layer 12. In the case where the active energy ray is ultraviolet ray, the irradiation amount of the ultraviolet ray is preferably 50 to 1000 mJ per square centimeter of the total light amount, and preferably 100 to 500 mJ per square centimeter. In addition, in active energy In the case where the ray is an electron beam, the irradiation amount of the electron beam is preferably 0.1 to 50 kGy.

Thereby, the release film 1 was obtained.

A method of coating a material for forming a release agent layer, for example, a gravure coat method, a bar coat method, a spray coat method, a spin coat method, a knife coat (knife coat) Method, roll coat method, die coat method.

The drying conditions of the material for forming the release agent layer are not particularly limited. The drying temperature is preferably from 50 to 100 degrees Celsius, and the drying time is preferably from 5 seconds to 1 minute. Thereby, it is possible to prevent the coating layer from being unintentionally deteriorated, and at the same time, it is possible to form the coating layer particularly efficiently. As a result, the productivity of the finally obtained release film 1 can be improved.

According to the above-described process, the release film 1 can be easily manufactured, and it is possible to manufacture a green sheet in which pinholes or partial thickness unevenness are suppressed. Further, the release film 1 having good mold release property and hardenability can be produced.

The present invention has been described above in detail based on preferred embodiments, but the invention is not limited thereto.

The above embodiment is used to exemplify the release film 1 with the release agent layer 12 disposed on the first surface 111 of the substrate 11. However, the release film 1 is not limited thereto, and an intermediate layer may be provided between the substrate 11 and the release agent layer 12. Such an intermediate layer may be a layer body for the purpose of improving the adhesion between the substrate 11 and the release agent layer 12, or may be used to further suppress static electricity when the release film 1 is formed before the green sheet is formed. A layer that occurs for the purpose.

Further, for example, in the above-described embodiment, the base material 11 is formed by one layer. However, the substrate 11 is not limited thereto, and may be formed of a stacked body, for example, not in one layer. For example, in the case where the substrate 11 is composed of two layers, the layer body in the direction of the release agent layer 12 may have a function of supporting the release agent layer 12, and the layer body in other directions may also have an antistatic function. Thereby, it is possible to have more excellent adhesion and antistatic properties to the release agent layer 12.

Further, the method for producing the release film of the present invention is not limited to the above method, and any process may be added as needed.

The embodiment will be described below.

Next, a specific embodiment of the release film relating to the present invention will be explained.

The production of the release film will be described below.

Embodiment 1 will be explained below.

First, a biaxially stretched polyethylene terephthalate film is prepared as a substrate (thickness: 31 μm, arithmetic mean roughness Ra0 of the first surface: 16 nm, maximum protrusion height of the first surface: Rp0: 196 nm, The arithmetic mean roughness Ra2 of the two surfaces: 16 nm, and the maximum protrusion height Rp2 of the second surface: 196 nm].

Next, as described below, the preparation of the material for forming a release agent layer is performed.

Prepared as the active energy ray-curable compound (A) dipentaerythritol hexaacrylate [solid content of 100% by mass], as the active energy ray-curable compound (B) containing poly(perfluoroalkylene ether) ) chain and methyl propyl A solution of a compound of methacryloyloxy (manufactured by DIC Corporation, trade name "RS-75", a solid content of 40% by mass) and an α-aminoalkyl group as a photopolymerization initiator (C) Acetophenone photopolymerization initiator [manufactured by BASF Corporation, trade name "IRGACURE 907", 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one , the solid content is 100% by mass]. The active energy ray-curable compound (A) is 94 parts by mass, the active energy ray-curable compound (B) is taken in one part by mass of the solid content, and the photopolymerization initiator (C) is taken in 5 parts by mass, and Mix the above. The mixture was diluted with a mixed solvent of isopropyl alcohol/methyl ethyl ketone (mass ratio: 3/1) to obtain a material for forming a release agent layer having a solid content of 20% by mass.

The obtained material for forming a release agent layer was applied onto the first surface of the substrate by a bar coater. The material for forming a release agent layer was continuously dried at 80 ° C for 1 minute to obtain a coating layer. The coating layer thus obtained was irradiated with ultraviolet rays (total light amount: 250 mJ per square centimeter) to form a release agent layer (thickness: 1 μm), thereby obtaining a release film.

Embodiment 2 will be described below.

A release film was produced in the same manner as in the above Example 1, except that the active energy ray-curable compound (A) was changed to 94 parts by mass of pentaerythritol tetraacrylate (solid content of 100% by mass).

Embodiment 3 will be explained below.

In addition to changing the active energy ray curable compound (A) to 94 parts by mass of pentaerythritol triacrylate (solid content of 100% by mass) A release film was produced in the same manner as in the foregoing Example 1 except for the rest.

Embodiment 4 will be explained below.

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

Embodiment 5 will be explained below.

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

Embodiment 6 will be explained below.

A solution containing a compound having a poly(perfluoroalkylene ether) chain and a methacryloyloxy group (manufactured by DIC Corporation), except that the active energy ray-curable compound (B) is changed to one part by mass. A free-form film was produced in the same manner as in the above Example 1, except that the product name "RS-76E" and a solid content of 40% by mass.

Example 7 will be explained below.

The active energy ray-curable compound (A) is changed from 94 parts by mass to 91 parts by mass, and the active energy ray-curable compound (B) is changed from one part by mass to four parts by mass. A release film was produced in the same manner as in the foregoing Example 1 except for the rest.

Embodiment 8 will be explained below.

In addition, the active energy ray-curable compound (A) is changed from 94 parts by mass to 93 parts by mass, and the active energy ray-curable compound (B) is changed from one part by mass to two parts by mass. With the rest before and before A release film was produced in the same manner as in Example 1.

Embodiment 9 will be explained below.

In addition, the active energy ray-curable compound (A) is changed from 94 parts by mass to 94.3 parts by mass, and the active energy ray-curable compound (B) is changed from one part by mass to 0.7 parts by mass. A release film was produced in the same manner as in the foregoing Example 1 except for the rest.

Embodiment 10 will be explained below.

In addition, the active energy ray-curable compound (A) is changed from 94 parts by mass to 94.7 parts by mass, and the active energy ray-curable compound (B) is changed from one part by mass to 0.3 parts by mass. A release film was produced in the same manner as in the foregoing Example 1 except for the rest.

Example 11 will be explained below.

In addition to changing the biaxially stretched polyethylene terephthalate film of the substrate to a biaxially stretched polyethylene terephthalate film [thickness: 38 μm, the arithmetic mean roughness Ra0 of the first surface: 15 nm, The other surface was manufactured in the same manner as in the above-described first embodiment except that the maximum protrusion height Rp0 of the first surface: 98 nm, the arithmetic mean roughness Ra2 of the second surface: 15 nm, and the maximum protrusion height Rp2 of the second surface: 98 nm]. Shaped film.

Embodiment 12 will be explained below.

In addition to changing the biaxially stretched polyethylene terephthalate film of the substrate to a biaxially stretched polyethylene terephthalate film [thickness: 38 μm, arithmetic mean roughness Ra0: 35 nm of the first surface, Maximum protrusion height of the first surface A release film was produced in the same manner as in the above Example 1, except that Rp0: 471 nm, the arithmetic mean roughness Ra2 of the second surface: 35 nm, and the maximum protrusion height Rp2 of the second surface: 471 nm.

Comparative Example 1 will be described below.

The rest of the active energy ray-curable compound (A) was changed from 94 parts by mass to 95 parts by mass, and the active energy ray-curable compound (B) was not added, in the same manner as in the above-mentioned Example 1. A release film is produced.

Comparative Example 2 will be described below.

A release film was produced in the same manner as in the above Example 1, except that the thickness of the release agent layer was changed to 0.2 μm.

Comparative Example 3 will be described below.

In addition to changing the biaxially stretched polyethylene terephthalate film of the substrate to a biaxially stretched polyethylene terephthalate film [thickness: 38 μm, the arithmetic mean roughness Ra0 of the first surface: 42 nm, The other surface was manufactured in the same manner as in the above-described first embodiment except that the maximum protrusion height Rp0 of the first surface was 619 nm, the arithmetic mean roughness Ra2 of the second surface was 42 nm, and the maximum protrusion height Rp2 of the second surface was 619 nm. Shaped film.

Comparative Example 4 will be described below.

In addition to changing the biaxially stretched polyethylene terephthalate film of the substrate to a biaxially stretched polyethylene terephthalate film [thickness: 38 μm, the arithmetic mean roughness Ra0 of the first surface: 15 nm, Maximum protrusion height of the first surface A release film was produced in the same manner as in the above Example 1, except that Rp0: 105 nm, the arithmetic mean roughness Ra2 of the second surface: 3 nm, and the maximum protrusion height Rp2 of the second surface: 15 nm].

In addition, the film thickness of the release agent layer of the release film obtained by each of the examples and the comparative examples was measured using a reflective film thickness meter (product name "F20", manufactured by FILMETRICS Co., Ltd.).

Further, the arithmetic mean roughness Ra1 of the outer surface of the release agent layer of the release film obtained by each of the examples and the comparative examples, and the maximum protrusion height Rp1 of the outer surface of the release agent layer were measured in the following manner. The arithmetic mean roughness Ra2 of the second surface of the material and the maximum protrusion height Rp2 of the second surface of the substrate. First, attach double-sided tape to the glass. Next, the release film obtained by each of the examples and the comparative examples was fixed to the double-sided tape so that the surface on which the arithmetic mean roughness and the maximum protrusion height were to be measured was upward. Next, the arithmetic mean roughness Ra1, Ra2 and the maximum protrusion heights Rp1 and Rp2 described above were measured in accordance with Japanese Industrial Standard JIS B0601-1994 using a surface roughness measuring machine SV3000S4 (stylus type) manufactured by Mitutoyo Corporation.

Further, in the table, dipentaerythritol hexaacrylate as the active energy ray-curable compound (A) is represented by A1, pentaerythritol tetraacrylate is represented by A2, and pentaerythritol triacrylate is represented by A3 as an active energy ray-curable compound. (B) A solution containing a compound having a poly(perfluoroalkylene ether) chain and methacryloyloxy (manufactured by DIC Corporation, trade name "RS-75", a solid content of 40 Percentage] is expressed as B1, containing A solution of a compound of a poly(perfluoroalkylene ether) chain and a methacryloyloxy group (manufactured by DIC Corporation, trade name "RS-76E", a solid content of 40% by mass) is represented as B2. α-Amine alkyl acetophenone photopolymerization initiator as a photopolymerization initiator [manufactured by BASF Corporation, trade name "IRGACURE 907", 2-methyl-1-[4-(methylthio)benzene) The group]-2-morpholinopropan-1-one] is represented by C1.

The evaluation of each of the examples and the comparative examples will be described below.

Evaluation of the release film obtained as described above was carried out below.

The evaluation of the hardenability of the release agent layer of each of the examples and the comparative examples will be described below.

A cloth containing 3 ml of methyl ethyl ketone (MEK) (Ozu The manufacturing company, BEMCOT AP-2), grinds the release film obtained by each of the examples and the comparative examples back and forth ten times so that the surface load weight of the release agent layer is 1 kg per square centimeter. Thereafter, the surface of the release agent layer was visually observed, and the hardenability of the release agent layer was evaluated on the following basis.

A: The release agent layer did not dissolve or fall off.

B: Part of the release agent layer was seen to dissolve.

C: The release agent layer is completely dissolved or detached from the substrate.

The evaluation of the slurry coatability of each of the examples and the comparative examples will be described below.

135 parts by mass of a mixed solvent of toluene/ethanol (mass ratio of 6/4) is added to 100 parts by mass of barium titanate powder (manufactured by Dai Chemical Industry Co., Ltd., trade name "BT-03", BaTiO ₃ ), 8 parts by mass of polyvinyl butyral (PVB) as a binder (manufactured by Sekisui Chemical Co., Ltd., trade name "S-LEC B.K BM-2") and 4 masses As a plasticizer, phthalate dioctyl (manufactured by Kanto Chemical Co., Ltd., trade name "dioctyl phthalate deer first grade"). The above materials were mixed and dispersed in a ball mill to prepare a ceramic slurry. The ceramic slurry was applied to the release agent layer of the release film obtained by each of the examples and the comparative examples by a die coater so that the thickness after drying was 1 μm, the width was 250 mm, and the length was 10 m. The surface is obtained to obtain a coating. Thereafter, the coating was dried at 80 ° C for 1 minute to obtain a green sheet. Thereafter, with respect to the release film in which the ceramic green sheet was formed, the surface of the green sheet was visually observed from the direction of the release film under a fluorescent lamp.

A: There is no pinhole in the ceramic green sheet.

B: 1 to 5 pinholes occur in the ceramic green sheet.

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

The release property evaluation of each of the examples and the comparative examples will be described below.

The green sheet formed by the above-mentioned slurry coatability evaluation was peeled off from the release film. At this time, it was evaluated whether the green sheet could be peeled off normally.

A: The green sheet was not broken, and it was smoothly peeled off from the release agent layer, and no green sheet remained on the release agent layer.

B: The green sheet was not broken, and it was peeled off slightly from the release agent layer, and no green sheet remained on the release agent layer.

C: When the green sheet is peeled off from the release film, the green sheet is broken or cannot be peeled off.

The defect evaluation (the number of recessed portions) 1 of the green sheets of the respective examples and the comparative examples will be described below.

A coating liquid of polyvinyl butyral resin was dissolved in a toluene/ethanol mixed solvent (mass ratio of 6/4) so as to have a thickness of 3 μm after drying, and applied to each of the examples and comparative examples. The release layer (outer surface) of the release film was obtained to obtain a coating. The coating was dried at 80 ° C for 1 minute to form a polyvinyl butyral resin layer. Next, a polyester tape was attached to the surface of the polyvinyl butyral resin layer. Next, the release film is peeled off from the polyvinyl butyral resin layer, and the polyvinyl butyral resin layer is transferred to the polyester glue. band. Next, the number of recesses on the surface of the polyvinyl butyral resin layer in contact with the release agent layer of the release film was counted. Specifically, the surface of the polyvinyl butyral resin layer was observed at a rate of 50 times the PSI mode using an optical interference type surface shape observation device "WYKO-1100" (manufactured by Veeco Co., Ltd.). The surface of the polyvinyl butyral resin layer was in the range of 91.2 × 119.8 μm, and the number of recesses having a depth of 150 nm or more was counted based on the surface shape profile. The number of recesses as the defect 1 of the green sheet was evaluated on the following basis. In addition, when a capacitor is produced from a green sheet having a release film having the following evaluation criteria "C", there is a tendency that a short circuit phenomenon due to a collapse voltage is likely to occur.

However, in the case where the release film having the reference "C" was evaluated in the above-described evaluation of the release property, the evaluation could not be performed.

A: The number of recesses is zero.

B: The number of recesses is 1 to 5.

C: The number of recesses is six or more.

The defect evaluation (the number of recesses) 2 of the green sheets of the respective examples and the comparative examples will be described below.

A coating solution of a polyvinyl butyral resin was dissolved in a toluene/ethanol mixed solvent (mass ratio of 6/4) in a thickness of 3 μm after drying, and applied to a polyethylene terephthalate having a thickness of 50 μm. On the ethylene glycol (PET) film, a coating was obtained. The coating was dried at 80 ° C for 1 minute to form a polyvinyl butyral resin layer. Next, the release film obtained by using each of the examples and the comparative examples is the second surface of the substrate of the release film and the polyvinyl butyral The resin layer is bonded to the polyvinyl butyral resin layer to obtain a stacked body. The stack was cut into 100 mm x 100 mm. Thereafter, the cut stack was pressed at 5 kg per square centimeter to transfer the protrusion shape of the second surface of the substrate of the release film to the polyvinyl butyral resin layer. Next, the release film is peeled off from the polyvinyl butyral resin layer, and the surface of the polyvinyl butyral resin layer which is in contact with the second surface of the substrate of the release film is counted to a depth of 300 nm or more. The number of recesses. Specifically, the surface of the polyvinyl butyral resin layer was observed at a rate of 50 times the PSI mode using an optical interference type surface shape observation device "WYKO-1100" (manufactured by Veeco Co., Ltd.). The surface of the polyvinyl butyral resin layer was in the range of 91.2 × 119.8 μm, and the number of recesses was counted based on the surface shape profile. The number of concave portions of the defect 2 as a green sheet was evaluated on the following basis. In addition, when a capacitor is produced from a green sheet having a release film having the following evaluation criteria "C", there is a tendency that a short circuit phenomenon due to a collapse voltage is likely to occur.

A: The number of the recesses having a depth of 300 nm or more is zero.

B: The number of recesses having a depth of 300 nm or more but less than 500 nm is one or more, and the number of recesses having a depth of 500 nm or more is zero.

C: The number of the recesses having a depth of 500 nm or more is one or more.

The handling evaluation of each of the examples and the comparative examples will be described below.

The operability in the case where the release film of each of the examples and the comparative examples was wound into a roll shape was evaluated.

A: The smoothness of the release film is good, and the case where the air is removed when wound into a roll shape is good, and the curling of the release film can be prevented.

B: Although the smoothness of the release film is slightly inferior, and the air removal is slightly inferior when wound into a roll shape, the curling of the release film slightly occurs, but the action of winding into a roller is not caused. Obstruction.

C: The smoothness of the release film was poor, and the case where the air was removed when wound into a roll shape was inferior, and the curling of the release film was remarkably occurred.

The cavitability evaluation of each of the examples and the comparative examples will be described below.

The release film obtained by each of the examples and the comparative examples had a width of 400 mm, a length of 5000 m, and was wound into a roll shape to obtain a release film roll. The release film cylinder was stored in an environment of 40 degrees Celsius and a humidity of 50% or less for 30 days. Thereafter, the appearance of the release film roll in this state was visually observed, and the caking property was evaluated on the following criteria.

A: The appearance of the release film roll before storage was compared, and the appearance of the release film roll after storage was not changed (no agglomeration).

B: The release film cylinder after storage has a region where the local color tone changes (although there is a tendency to agglomerate, it can still be used).

C: In the release film cylinder after storage, the color tone of a large area is changed (having agglomeration).

These results are shown in Table 2.

As is clear from Table 2, the release film of the present invention is excellent in the coatability of the slurry, the release property of the green sheet (film) which has been formed, and the smoothness of the surface and back surface of the green sheet. Further, the amount of static electricity of the release film of the present invention is low, and the evaluation of agglomeration is also excellent. Further, the release film of the present invention has an effect of suppressing occurrence of pinholes or partial thickness unevenness of the green sheet (film). Moreover, when the release film of the present invention is rolled into a roll shape, It has good handleability and is less prone to agglomeration when rolled into a roll. Further, in the release film of the present invention, the material for forming a release agent layer is excellent in conformability, and a release agent layer can be formed in an atmospheric environment.

Conversely, any of the evaluations in the comparative examples did not yield satisfactory results.

1‧‧‧Fractal film

11‧‧‧Substrate

111‧‧‧The first surface of the substrate

112‧‧‧Second surface of the substrate

12‧‧‧ release agent layer

121‧‧‧Outer surface of the release agent layer

Claims (5)

A release film comprising: a substrate having a first surface and a second surface; and a release agent layer formed by irradiating a coating layer with an active energy ray and hardening The coating layer is formed by applying a material for forming a release agent layer containing one active energy ray-curable compound (A) and one active energy ray-curable compound (B) to the first surface of the substrate. The active energy ray-curable compound (A) has a group selected from the group consisting of a (meth)acryloyl group, an alkenyl group, and a maleimide group. At least one of the reactive functional groups and having no fluorine atom in the molecule, the active energy ray-curable compound (B) having a composition selected from the group consisting of (meth) acrylonitrile, alkenyl and maleimine One of the group is at least one reactive functional group and has a fluorine atom in the molecule; wherein the outer surface of one of the release agent layers has an arithmetic mean roughness Ra1 of 8 nm or less, and the release agent layer is externally The maximum protrusion height Rp1 of the surface is 50 nm or less; wherein the substrate The arithmetic mean roughness Ra2 of the second surface is 5 to 40 nm, and the maximum protrusion height Rp2 of the second surface of the substrate is 60 to 500 nm. The release film according to claim 1, wherein the active energy ray-curable compound (B) has a poly(perfluoroalkylene ether) in the molecule (poly(perfluoro) Alkene ether)) chain. The release film according to claim 1, wherein the active energy ray-curable compound (B) is contained in the release agent layer-forming material in a solid content of 0.1 to 5 by mass. The release film according to claim 1, wherein one of the release agent layers has an average film thickness of 0.3 to 2 μm. The release film according to any one of claims 1 to 4 is used for the manufacture of a green sheet.