WO2014141571A1

WO2014141571A1 - Release film for green sheet manufacturing, and method for manufacturing release film for green sheet manufacturing

Info

Publication number: WO2014141571A1
Application number: PCT/JP2013/085202
Authority: WO
Inventors: 知巳深谷; 慎也市川
Original assignee: リンテック株式会社
Priority date: 2013-03-15
Filing date: 2013-12-27
Publication date: 2014-09-18
Also published as: KR102037127B1; SG11201507464UA; KR20150132194A; CN105050780B; JP2014177094A; MY172242A; TWI551458B; CN105050780A; PH12015502152B1; TW201434656A; JP6033135B2; PH12015502152A1

Abstract

This release film for green sheet manufacturing has a substrate having a first face and a second face, a smoothing layer provided to the first face of the substrate, and a release agent layer provided to a face of the smoothing layer on a reverse side thereof from the substrate, and is characterized in that the smoothing layer is formed by irradiating, with active energy rays, a smoothing layer formation composition including a thermosetting compound having a mass average molecular weight of 950 or less, and curing the smoothing layer formation composition, the arithmetic mean roughness (Ra₁) of an outer surface of the releasing agent layer is 8 nm or less, and the maximum projection height (Rp₁) of the outer surface of the releasing agent layer is 50 nm or less. Through the present invention, a release film for green sheet manufacturing can be obtained whereby it is possible to prevent pinholing and the like in the surface of the green sheet, and to manufacture a highly reliable green sheet.

Description

Release film for producing green sheet and method for producing release film for producing green sheet

The present invention relates to a release film for producing a green sheet and a method for producing a release film for producing a green sheet.

In the production of ceramic capacitors, a release film for producing a green sheet is used to form a green sheet.

The release film for producing green sheets is generally composed of a base material and a release agent layer. A green sheet is produced by applying a ceramic slurry in which ceramic particles and a binder resin are dispersed and dissolved in an organic solvent on such a release film for producing a green sheet, and drying the slurry. Moreover, the manufactured green sheet peels from the peeling film for green sheet manufacture, and is used for manufacture of a ceramic capacitor.

In the production of a green sheet using a conventional release film for producing a green sheet, problems such as the occurrence of pinholes on the surface of the green sheet due to the surface irregularities of the release film for producing a green sheet being transferred to the green sheet was there. As a result, the ceramic capacitor manufactured by laminating such green sheets has a problem that a malfunction due to a short circuit occurs. In order to solve such a problem, the surface (cast surface) of the release film for producing a green sheet is required to have very high smoothness.

Therefore, as a method for producing a release film for producing a green sheet having a smooth surface, a thermosetting resin liquid is applied to one surface of a substrate sheet having fine irregularities on the surface, and then heated and cured. There has been proposed a release film in which a thermosetting resin layer formed by the above method is provided and a release agent is applied on the thermosetting resin layer to form a release agent layer (see, for example, Patent Document 1).

In addition, with the recent reduction in size and density of ceramic capacitors, further reduction in the thickness of green sheets is required. However, in the conventional release film for producing a green sheet, if a thin green sheet is to be produced, a pinhole or the like is generated on the surface of the green sheet, and it is difficult to obtain a reliable green sheet.

JP 2007-069360 A

An object of the present invention is to provide a release film for producing a green sheet that can prevent the occurrence of pinholes and partial thickness variations on the surface of the green sheet and can produce a highly reliable green sheet. There is to do. Another object of the present invention is to provide a production method for producing a release film for producing a green sheet, which can prevent pinholes and partial thickness variations on the surface of the green sheet. is there.

Such an object is achieved by the present inventions (1) to (8) below.
(1) A release film for producing a green sheet,
A substrate having a first surface and a second surface;
A smoothing layer provided on the first surface of the substrate;
A release agent layer provided on the surface side opposite to the base material of the smoothing layer,
The smoothing layer is formed by irradiating and curing an active energy ray on a composition for forming a smoothing layer containing an active energy ray-curable compound,
An arithmetic average roughness Ra ₁ of the outer surface of the release agent layer is 8 nm or less, and a maximum protrusion height Rp _{1 of the} outer surface of the release agent layer is 50 nm or less. Release film.

(2) The green according to (1), wherein the arithmetic average roughness Ra _{2 of} the first surface is 10 to 200 nm and the maximum protrusion height Rp _{2 of} the first surface is 80 to 1000 nm. Release film for sheet production.

(3) The release film for producing a green sheet according to the above (1) or (2), wherein the active energy ray-curable compound is a compound having a mass average molecular weight of 950 or less.

(4) The release film for producing a green sheet according to any one of (1) to (3), wherein the active energy ray-curable compound is an ultraviolet curable compound, and the active energy ray is ultraviolet light.

(5) The release film for producing a green sheet according to any one of (1) to (4), wherein the smoothing layer has an average film thickness of 0.2 to 10 μm.

(6) The smoothing layer has a surface opposite to the substrate, the arithmetic mean roughness Ra ₄ of the surface opposite to the base material of the smoothing layer has a 8nm or less, and the smoothing release film for green sheet production according to any one of the maximum protrusion height of the surface opposite the substrate layer Rp ₄ is (1) to at 50nm or less (5).

(7) The arithmetic mean roughness Ra _{3 of} the second surface is 10 to 200 nm, and the maximum protrusion height Rp _{3 of} the second surface is 80 to 1000 nm (1) to (6) A release film for producing a green sheet according to any one of the above.

(8) A method for producing a release film for producing a green sheet according to any one of (1) to (7) above,
A base material preparing step of preparing the base material having the first surface and the second surface;
A coating layer forming step of forming a coating layer by coating the smoothing layer forming composition containing the active energy ray-curable compound on the first surface side of the substrate;
A smoothing layer forming step of forming the smoothing layer by irradiating and curing the active energy ray on the coating layer;
A release agent layer forming step of forming the release agent layer on the surface side of the smoothing layer opposite to the substrate;
The arithmetic average roughness Ra _{1 of the} outer surface of the release agent layer is 8 nm or less, and the maximum protrusion height Rp _{1 of the} outer surface of the release agent layer is 50 nm or less. A method for producing a release film for producing a green sheet.

According to the present invention, there is provided a release film for producing a green sheet that can prevent the occurrence of pinholes and partial thickness variations on the surface of the green sheet and can produce a highly reliable green sheet. can do. In particular, even when a substrate having a relatively large surface roughness is used as a substrate constituting the release film for producing a green sheet, a release film for producing a green sheet having excellent outer surface smoothness is provided. be able to. If this release film for producing a green sheet is used, pinholes, partial thickness variations and the like can be prevented from occurring on the surface of the green sheet. As a result, when a capacitor is produced by laminating green sheets, it is possible to prevent a problem due to a short circuit from occurring. Moreover, according to this invention, the peeling film for green sheet manufacture which can manufacture the green sheet excellent in the smoothness of the surface can be manufactured easily and reliably.

FIG. 1 is a cross-sectional view of a release film for producing a green sheet of the present invention.

Hereinafter, the present invention will be described in detail based on preferred embodiments.
<Peeling film for manufacturing green sheets>
The release film for producing a green sheet of the present invention is used for producing a green sheet. And the manufactured green sheet is used for manufacture of a ceramic capacitor etc., for example.

FIG. 1 is a cross-sectional view of a release film for producing a green sheet of the present invention. In the following description, the upper side in FIG. 1 is referred to as “upper” and the lower side is referred to as “lower”.

As shown in FIG. 1, the release film 1 for producing a green sheet includes a base material 11 having a first surface 111 and a second surface 112, and a smooth surface provided on the first surface 111 of the base material 11. And the release agent layer 13 provided on the surface 121 side opposite to the base material of the smoothing layer 12. That is, as shown in FIG. 1, the release film 1 for producing a green sheet has a three-layer structure in which a base material 11, a smoothing layer 12, and a release agent layer 13 are laminated so as to be joined to each other in this order. It is.

In addition, in this specification, when manufacturing a green sheet using the peeling film 1 for green sheet manufacture, the green sheet applies the ceramic slurry which melt | dissolved on the outer surface 131 of the releasing agent layer 13, for example. Is formed.

In the present invention, the release film 1 for producing a green sheet has a smoothing layer 12 between the substrate 11 and the release agent layer 13. The smoothing layer 12 is formed by irradiating and curing an active energy ray to a smoothing layer forming composition containing an active energy ray-curable compound, and the arithmetic average of the outer surface 131 of the release agent layer 13. It is characterized in that the roughness Ra ₁ is 8 nm or less and the maximum protrusion height Rp ₁ of the outer surface 131 of the release agent layer 13 is 50 nm or less.

By having such characteristics, it is possible to obtain the release film 1 for producing a green sheet which is excellent in smoothness of the outer surface 131 of the release agent layer 13 and excellent in peelability. If a green sheet is manufactured using this release film 1 for manufacturing a green sheet, pinholes and partial thickness variations are prevented from occurring on the surface of the green sheet, and a highly reliable green sheet is manufactured. be able to. As a result, when a capacitor is produced by laminating green sheets, it is possible to prevent a problem due to a short circuit from occurring.

By the way, the film used as the substrate 11 has various surface roughnesses. Inexpensive films tend to have relatively rough surface roughness. Even when a release film for producing a green sheet is formed using a substrate having such a relatively rough surface, a smoothing layer having the above-described characteristics can be provided on the surface of the substrate. The unevenness on the surface of the base material can be accurately embedded (cancelled). As a result, the surface of the smoothing layer opposite to the substrate can be smoothed. Thereby, it can prevent that the unevenness | corrugation of the surface of a base material affects the outer surface of the release agent layer formed on the smoothing layer, and was excellent in the smoothness of the outer surface of a release agent layer. A release film for producing a green sheet can be obtained.

Hereafter, each layer which comprises the peeling film 1 for green sheet manufacture which concerns on this embodiment is demonstrated one by one.

<Substrate 11>
The base material 11 has a function of imparting physical strength such as rigidity and flexibility to the release film 1 for producing a green sheet (hereinafter sometimes simply referred to as “release film 1”).

As shown in FIG. 1, the base material 11 has a first surface 111 and a second surface 112.
The material constituting the substrate 11 is not particularly limited, and examples thereof include polyester resins such as polybutylene terephthalate resin, polyethylene terephthalate resin and polyethylene naphthalate resin, polyolefin resins such as polypropylene resin and polymethylpentene resin, and polycarbonate. Examples thereof include a film made of plastic. The substrate 11 may be a single layer film or a multilayer film of two or more layers of the same type or different types. Among these, a polyester film is preferable, a polyethylene terephthalate film is more preferable, and a biaxially stretched polyethylene terephthalate film is more preferable. In particular, the polyester film is less prone to dust and the like during its processing and use. Therefore, for example, when a green sheet is manufactured using the release film 1 manufactured using a polyester resin, it is possible to effectively prevent a ceramic slurry coating failure due to dust or the like. As a result, a green sheet with fewer pinholes and the like can be manufactured.

Further, the base material 11 may contain a filler or the like in addition to the above materials. Examples of the filler include silica, titanium oxide, calcium carbonate, kaolin, aluminum oxide, and the like, and one or more of these can be used in combination. By including such a filler, while giving mechanical strength to the base material 11, the slipperiness of the front and back of the base material 11 improves, and blocking can be suppressed.

The base material 11 preferably has an arithmetic average roughness Ra ₂ of the first surface 111 of 10 to 200 nm and a maximum protrusion height Rp ₂ of 80 to 1000 nm.

In particular, the arithmetic average roughness Ra ₂ of the first surface 111 is more preferably 15 to 100 nm, and the arithmetic average roughness Ra ₂ of the first surface 111 is further preferably 20 to 50 nm. Further, more preferably the maximum projection height Rp ₂ of the first surface 111 is 90 ~ 800 nm, the maximum projection height Rp ₂ of the first surface 111 is more preferably in the range of 100 ~ 600 nm.

When the arithmetic average roughness Ra ₂ and the maximum protrusion height Rp _{2 of} the first surface 111 are within the above ranges, even if the smoothing layer 12 described later has a relatively thin film thickness, The unevenness of the surface 111 can be embedded more reliably, and the surface 121 opposite to the base material 11 of the smoothing layer 12 can be made smoother. As a result, it is possible to more reliably prevent the unevenness of the first surface 111 of the substrate 11 from affecting the outer surface 131 of the release agent layer 13 formed on the smoothing layer 12.

In addition, the base 11 having the arithmetic average roughness Ra ₂ of the first surface 111 and the maximum protrusion height Rp ₂ within the above range is relatively inexpensive and easily available.

On the other hand, when the arithmetic average roughness Ra ₂ of the first surface 111 exceeds the upper limit value, the unevenness of the first surface 111 is sufficiently filled depending on the constituent material of the smoothing layer forming composition. Therefore, it may be necessary to make the release agent layer 13 relatively thick.

In the present specification, the arithmetic average roughness Ra ₂ and the maximum protrusion height Rp ₂ of the first surface 111 of the substrate 11 are determined according to JIS B0601-1994 surface roughness measuring machine SV3000S4 (Mitutoyo Co., Ltd.). It is a value obtained by measurement by a stylus type). In the present specification, unless otherwise specified, the “arithmetic average roughness and maximum protrusion height” refer to values obtained by measurement as described above.

The base material 11 preferably has an arithmetic average roughness Ra ₃ of the second surface 112 of 10 to 200 nm and a maximum protrusion height Rp ₃ of 80 to 1000 nm. In particular, the arithmetic mean roughness Ra ₃ of the second surface 112 is more preferably from 15 ~ 100 nm, the arithmetic mean roughness Ra ₃ of the second surface 112 is even more preferably 20 ~ 50 nm. Further, more preferably the maximum projection height Rp ₃ of the second surface 112 is 90 ~ 800 nm, the maximum projection height Rp ₃ of the second surface 112 is more preferably in the range of 100 ~ 600 nm.

When the arithmetic average roughness Ra ₃ of the second surface 112 and the maximum protrusion height Rp ₃ are within the above ranges, it is preferable that winding deviation or the like occurs when the release film 1 is wound into a roll shape. Can be prevented. Moreover, when the release film 1 is wound up and stored in a roll shape, blocking can be prevented from occurring. Specifically, the release film 1 can be wound and stored in a roll shape around a core material made of paper, plastic, metal, or the like as necessary so that the release agent layer 13 is on the inside. . At this time, when the arithmetic average roughness Ra ₃ of the second surface 112 and the maximum protrusion height Rp ₃ are within the above ranges, air release is good when the release film 1 is wound into a roll shape. Thus, winding deviation can be effectively suppressed. Therefore, when winding the release film 1, it is not necessary to increase the winding tension, and it is possible to suppress the deformation of the winding core portion caused by the winding tension. In addition, when the arithmetic average roughness Ra ₃ of the second surface 112 and the maximum protrusion height Rp ₃ in the roll-shaped release film 1 are within the above ranges, the release agent layer 13 and the second base material 11 The occurrence of blocking caused by the close contact with the surface 112 can be more effectively prevented. Therefore, the roll-shaped release film 1 can be easily fed out.

On the other hand, when the arithmetic average roughness Ra ₃ of the second surface 112 is less than the lower limit value, when winding up into a roll shape, the front and back of the release film 1 (with the second surface 112 of the base material 11 and There is a possibility that blocking is likely to occur on the outer surface 131) of the release agent layer 13. 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, while making the softness | flexibility of the peeling film 1 moderate, the tolerance with respect to tearing, a fracture | rupture, etc. can be made especially excellent.

<Smoothing layer 12>
The smoothing layer 12 has a function of reducing the influence of the unevenness of the first surface 111 of the substrate 11 on the outer surface 131 of the release agent layer 13.

As shown in FIG. 1, the smoothing layer 12 is provided on the first surface 111 of the substrate 11.
The smoothing layer 12 is formed by applying a composition for forming a smoothing layer on the first surface 111 of the substrate 11, and irradiating the obtained coating layer with an active energy ray and curing it. Is done.

The composition for smoothing layer formation contains the active energy ray hardening-type compound hardened | cured by irradiating an active energy ray.

In addition, the composition for smoothing layer formation before irradiating an active energy ray exists in the uncured state or the semi-hardened state at room temperature.

Further, such a composition for forming a smoothing layer has appropriate fluidity when applied on the first surface 111 of the substrate 11. Therefore, by using such a composition for forming a smoothing layer, the unevenness of the first surface 111 of the substrate 11 can be easily embedded, and the embedded state can be reliably maintained. As a result, it is possible to prevent the unevenness of the base material 11 from affecting the surface 121 of the smoothing layer 12 opposite to the base material 11 (hereinafter also referred to as “third surface 121”), The third surface 121 of the smoothing layer 12 can be smoothed. Therefore, the outer surface 131 of the release agent layer 13 formed on the third surface 121 of the smoothing layer 12 can be made smoother.

Examples of the active energy ray-curable compound include an ultraviolet curable compound that is cured by irradiating ultraviolet rays, an infrared curable compound that is cured by irradiating infrared rays, and an X-ray that is cured by irradiating X-rays. Examples thereof include a curable compound, an electron beam curable compound that is cured by irradiation with an electron beam, and a visible light curable compound that is cured by irradiation with visible light. Among these, an ultraviolet curable compound is particularly preferable. The ultraviolet curable compound has appropriate fluidity. For this reason, it is possible to form a smooth surface state by applying the smoothing layer forming composition onto the first surface 111 of the substrate 11. Therefore, even if the smoothing layer 12 is formed relatively thin, the unevenness of the first surface 111 of the substrate 11 can be reliably embedded. As a result, the third surface 121 of the smoothing layer 12 can be smoothed more easily and reliably.

As the active energy ray-curable compound that can be cured by irradiating active energy rays such as ultraviolet rays and electron beams, those having two or more polymerizable unsaturated groups in the molecule are used. Examples include urethane acrylate compounds, polyfunctional acrylate compounds, polyester acrylate compounds, epoxy acrylate compounds, polyol acrylate compounds, and the like. Among these, urethane acrylate compounds are preferable.

The urethane acrylate compound can be obtained, for example, by esterifying a polyurethane oligomer obtained by reaction of polyether polyol or polyester polyol with polyisocyanate with (meth) acrylic acid. Specifically, phenylglycidyl ether acrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol triacrylate toluene diisocyanate urethane prepolymer, pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer, dipentaerythritol Examples include pentaacrylate hexamethylene diisocyanate urethane prepolymer.

Examples of the polyfunctional acrylate compound include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, Neopentyl glycol adipate di (meth) acrylate, dicyclopentanyl di (meth) acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (Meth) acrylate, pentaerythritol tri (meth) acrylate, tris (acryloxyethyl) isocyanurate, dipentaerythritol hexa (meth) acrylate and the like.

Polyester acrylate compounds can be obtained by, for example, esterifying hydroxyl groups of polyester oligomers having hydroxyl groups at both ends obtained by condensation of polyvalent carboxylic acids and polyhydric alcohols with (meth) acrylic acid, or polyvalent carboxylic acids. It can be obtained by esterifying the terminal hydroxyl group of an oligomer obtained by adding alkylene oxide to (meth) acrylic acid.

The epoxy acrylate compound can be obtained, for example, by reacting (meth) acrylic acid with an oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolak type epoxy resin and esterifying it.

The polyol acrylate compound can be obtained, for example, by esterifying the hydroxyl group of the polyether polyol with (meth) acrylic acid.

In addition, the active energy ray-curable compound preferably has a mass average molecular weight of 950 or less, and more preferably has a mass average molecular weight of 300 to 700. Thereby, the viscosity of the composition for smoothing layer formation before apply | coating to the 1st surface 111 of the base material 11 and irradiating an active energy ray can be made moderate. Thereby, the composition for smoothing layer formation has further moderate fluidity | liquidity. By forming the smoothing layer 12 on the first surface 111 side of the base material 11 using such a smoothing layer forming composition, the unevenness of the first surface 111 of the base material 11 is more reliably embedded. be able to. As a result, it is possible to more reliably prevent the unevenness of the base material 11 from affecting the third surface 121 of the smoothing layer 12, and to make the third surface 121 of the smoothing layer 12 smoother. be able to. Therefore, it is possible to particularly prevent the unevenness of the base material 11 from affecting the outer surface of the release agent layer 13 formed on the smoothing layer 12, and the outer surface 131 of the release agent layer 13 can be further increased. Can be smooth.

In particular, even if the unevenness of the surface of the first surface 111 of the substrate 11 is relatively large, the unevenness of the first surface 111 is reduced by the action and effect of the smoothing layer forming composition as described above. Since it can be embedded suitably, the release film 1 having excellent smoothness of the outer surface 131 of the release agent layer 13 can be obtained.

On the other hand, when the mass average molecular weight of the active energy ray-curable compound is less than the lower limit, the viscosity of the smoothing layer forming composition decreases, and the time for curing the smoothing layer 12 becomes relatively long. There is a case. In addition, when the mass average molecular weight of the active energy ray-curable compound exceeds the upper limit, depending on the type of the active energy ray-curable compound, the viscosity of the smoothing layer-forming composition becomes relatively high. In order to adjust, it may be necessary to add a viscosity modifier or the like.

In addition to the active energy ray-curable compound, the smoothing layer-forming composition may contain a solvent, if necessary. Thereby, the viscosity of the composition for smoothing layer formation at the time of apply | coating to the 1st surface 111 of the base material 11 can be adjusted easily.

Examples of the solvent include aromatic hydrocarbons such as toluene and xylene, fatty acid esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, and organic solvents such as alcohols such as methanol, ethanol and isopropyl alcohol. 1 type or 2 types or more of them can be used in combination. Thereby, it becomes easy to make moderate the viscosity before apply | coating to the 1st surface 111 of the base material 11, and irradiating an active energy ray of the composition for smoothing layer formation.

The smoothing layer forming composition may contain other components in addition to the components as described above. Examples of other components include a crosslinking agent, a photopolymerization initiator, a viscosity modifier, a catalyst, a dye, a dispersant, an antistatic agent, and a curing agent. When the other components are contained, the content of the other components in the smoothing layer forming composition (in terms of solid content) is preferably 0.1 to 10% by mass.

The content of the active energy ray-curable compound in the composition for forming a smoothing layer containing a solvent is not particularly limited, but is preferably 0.5 to 60% by mass, and more preferably 1 to 45% by mass. Thereby, it becomes easy to make the viscosity of the composition for smoothing layer formation suitable.

The content of the active energy ray-curable compound in the smoothing layer forming composition (in terms of solid content) is not particularly limited, but is preferably 90% by mass or more, and more preferably 95% by mass or more. Thereby, the sclerosis | hardenability of the composition for smoothing layer formation can be made especially excellent.

Also, arithmetic mean roughness of the third surface 121 of the smoothing layer 12 Ra ₄ is a 8nm or less, and preferably has a maximum projection height Rp ₄ is 50nm or less. In particular, the arithmetic average roughness Ra ₄ of the third surface 121 is more preferably 6 nm or less. Further, it is more preferable that the maximum protrusion height Rp ₄ of the third surface 121 is 40 nm or less.

When the arithmetic average roughness Ra ₄ and the maximum protrusion height Rp _{4 of} the third surface 121 are within the above ranges, the influence of the unevenness of the surface of the base material 11 on the outer surface 131 of the release agent layer 13 is more reliably achieved. Can be prevented.

On the other hand, if the arithmetic average roughness Ra ₄ of the third surface 121 is less than the lower limit value, the adhesiveness to the release agent layer 13 may be lowered depending on the constituent material of the smoothing layer 12 and the like. is there. On the other hand, when the arithmetic average roughness Ra ₄ of the third surface 121 exceeds the upper limit, it may be necessary to provide a new smoothing layer between the release agent layer 13 and the smoothing layer 12. .

On the other hand, when the maximum protrusion height Rp ₄ of the third surface 121 is less than the lower limit value, in order to improve the adhesion with the release agent layer 13, on the third surface 121 of the smoothing layer 12, In some cases, it is necessary to perform a treatment for improving the adhesion. On the other hand, if the maximum protrusion height Rp ₄ of the third surface 121 exceeds the upper limit, it may be necessary to provide a new smoothing layer between the release agent layer 13 and the smoothing layer 12. .

The average film thickness of the smoothing layer 12 is not particularly limited, but is preferably 0.2 to 10 μm, and more preferably 0.3 to 5 μm. Thereby, the unevenness | corrugation of the 1st surface 111 of the base material 11 can be embedded more reliably, and the smoothness of the outer surface of the peeling film 1 can be made higher. In particular, since the composition for forming a smoothing layer of the present embodiment is formed to contain the active energy ray-curable compound as described above, even if the smoothing layer 12 has a relatively thin film thickness, The unevenness of the first surface 111 of the material 11 can be embedded more easily and reliably. Moreover, the softness | flexibility of the smoothing layer 12 can be made moderate.

On the other hand, if the average film thickness of the smoothing layer 12 is less than the lower limit value, the unevenness of the first surface 111 of the substrate 11 may be sufficient depending on the components constituting the smoothing layer forming composition. Therefore, it may be necessary to use the first surface 111 having a relatively small surface roughness. Moreover, when the average film thickness of the smoothing layer 12 exceeds the above upper limit, depending on the components constituting the composition for forming the smoothing layer, curling of the release film 1 is likely to occur due to curing shrinkage of the smoothing layer 12. Therefore, the handleability of the release film 1 may be reduced.

<Release layer 13>
The release agent layer 13 has a function of imparting peelability to the release film 1.

As shown in FIG. 1, the release agent layer 13 is provided on the third surface 121 side of the smoothing layer 12.

The release agent layer 13 is a layer formed by applying a release agent layer forming composition to the third surface 121 of the smoothing layer 12, drying and curing it.

Such a composition for forming a release agent layer contains a release agent.
Examples of the release agent include alkyd compounds, acrylic compounds, silicone compounds, long-chain alkyl group-containing compounds, fluorine compounds, and the like, and one or more of these can be used in combination. Among these, it is preferable to use an alkyd compound, an acrylic compound, a silicone compound, or a long-chain alkyl group-containing compound. As a result, it is possible to obtain the release agent layer 13 that has an appropriate curability and is particularly excellent in the peelability to the green sheet.

Specific examples of alkyd compounds include modified products such as long-chain alkyl-modified alkyd compounds and silicone-modified alkyd compounds. When an alkyd compound is used, a crosslinking agent or a catalyst may be further added to the release agent layer forming composition. The release agent layer 13 having an alkyd compound having a cross-linked structure can be obtained by a method of heat-curing such a release agent layer forming composition. As a result, when the green sheet is formed on the release agent layer 13, it is possible to prevent the release property of the release agent layer 13 from being prevented from being transferred to the green sheet. it can.

As specific examples of the acrylic compound, modified products such as a long-chain alkyl-modified acrylic compound and a silicone-modified acrylic compound can be used. When the release agent layer forming composition contains an acrylic compound, a crosslinking agent or a catalyst may be further added to the release agent layer forming composition. The release agent layer 13 having an acrylic compound having a crosslinked structure can be obtained by a method of heat-curing such a release agent layer forming composition. As a result, it is possible to prevent the peelable acrylic compound from moving to the smoothing layer 12 and to prevent the peelability of the release agent layer 13 from being lowered.

In addition, as a silicone compound, a silicone compound having dimethylpolysiloxane as a basic skeleton can be used as a specific example. Examples of the silicone compound include an addition reaction type, a condensation reaction type, an ultraviolet curable type, and an electron beam curable type. The addition reaction type silicone compound has high reactivity and excellent productivity. Compared with the condensation reaction type silicone compound, the addition reaction type silicone compound has advantages such as little change in peel force after production and no cure shrinkage. It is preferable to use it.

Specific examples of the addition reaction type silicone compound include two alkenyl groups having 2 to 10 carbon atoms such as vinyl group, allyl group, propenyl group, and hexenyl group at the terminal and / or side chain of the molecule of the compound. The organopolysiloxane provided above is mentioned. When such an addition reaction type silicone compound is used, it is preferable to use a crosslinking agent and a catalyst in combination.

Examples of the crosslinking agent include, for example, organopolysiloxane having hydrogen atoms bonded to at least two silicon atoms in one molecule, specifically, a dimethylhydrogensiloxy group end-capped dimethylsiloxane-methylhydrogensiloxane copolymer. And trimethylsiloxy group end-capped dimethylsiloxane-methylhydrogensiloxane copolymer, trimethylsiloxy group end-capped methylhydrogenpolysiloxane, poly (hydrogensilsesquioxane), and the like.

Examples of the catalyst include finely divided platinum, finely divided platinum adsorbed on a carbon powder carrier, chloroplatinic acid, alcohol-modified chloroplatinic acid, olefin complexes of chloroplatinic acid, white metal compounds such as palladium and rhodium, etc. Is mentioned. By using such a catalyst, the curing reaction of the composition for forming a release agent layer can be advanced more efficiently.

For example, as the long-chain alkyl group-containing compound, for example, polyvinyl carbamate obtained by reacting a polyvinyl alcohol polymer with a long-chain alkyl isocyanate having 8 to 30 carbon atoms, or polyethyleneimine with 8 to 30 carbon atoms. An alkylurea derivative obtained by reacting a long-chain alkyl isocyanate is used.

In addition, as the fluorine compound, for example, a fluorine silicone compound, a fluorine boron compound, or the like can be used.

Moreover, the release agent layer forming composition may contain a dispersion medium and a solvent in addition to the release agent described above. By including at least one of the dispersion medium and the solvent, the viscosity of the composition for forming a release agent layer before being applied to the third surface 121 of the smoothing layer 12 and dried can be made moderate.

Examples of the dispersion medium or solvent include aromatic solvents such as toluene, fatty acid esters such as ethyl acetate, ketones such as methyl ethyl ketone, and organic solvents such as aliphatic hydrocarbons such as hexane and heptane. Species or a combination of two or more can be used.

In addition, in addition to the above components, the release agent layer forming composition may contain other components. Examples of other components include a catalyst, a dye, a dispersant, an antistatic agent, and a curing agent. When the other components are included, the content of the other components in the release agent layer forming composition is preferably 0.1 to 10% by mass.

Further, the content of the release agent in the release agent layer forming composition is not particularly limited, but is preferably 0.3 to 10% by mass.

As described above, the outer surface 131 of the release agent layer 13 has an arithmetic average roughness Ra ₁ of 8 nm or less, and a maximum protrusion height Rp ₁ of 50 nm or less. In particular, the arithmetic mean roughness Ra ₁ of the outer surface 131 of the release agent layer 13 is preferably 6 nm or less. In addition, the maximum protrusion height Rp ₁ of the outer surface 131 of the release agent layer 13 is preferably 40 nm or less.

When the arithmetic average roughness Ra ₁ and the maximum protrusion height Rp ₁ of the outer surface 131 of the release agent layer 13 are within the above ranges, a relatively high smooth surface shape of the outer surface 131 is formed when the green sheet is formed. By being transferred to the green sheet, pinholes and the like can be more suitably prevented from occurring on the surface of the green sheet. As a result, a green sheet having a higher smooth surface can be obtained.

Further, the release agent layer 13 preferably has an average film thickness of 0.01 to 3 μm, and more preferably 0.03 to 1 μm. If the thickness of the release agent layer 13 is less than 0.01 μm, the function as the release agent layer may not be sufficiently exhibited depending on the material constituting the release agent layer 13 or the like. On the other hand, when the thickness of the release agent layer 13 exceeds 3 μm, when the release film 1 is wound into a roll, blocking is likely to occur. There may be a problem that the charging property at the time of unwinding increases.

<Method for producing release film for producing green sheet>
Next, a preferred embodiment of the method for producing the release film 1 for producing a green sheet as described above will be described.

The manufacturing method of the release film 1 of the present embodiment includes a base material preparing step for preparing the base material 11 and a smoothing layer forming composition containing a predetermined active energy ray-curable compound on the first surface of the base material 11. The coating layer forming step for forming the coating layer by applying to 111 and drying it as necessary, and the smoothing layer 12 by forming the coating layer by irradiating and curing the active energy ray And a release agent layer forming step of forming the release agent layer 13 on the surface 121 side of the smoothing layer 12 opposite to the substrate 11.

Hereinafter, each step will be described in detail.
<Base material preparation process>
First, the base material 11 is prepared.
As the base material 11, the base material 11 having the configuration described above can be used.

In addition, the first surface 111 of the substrate 11 can be subjected to a surface treatment such as an oxidation method or a primer treatment. Thereby, the adhesiveness of the base material 11 and the smoothing layer 12 provided in the 1st surface 111 side of the base material 11 can be made especially excellent.

What is necessary is just to select suitably as surface treatment by an oxidation method etc. according to the kind etc. of the base material 11. FIG. For example, corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone treatment, ultraviolet irradiation treatment and the like can be mentioned. Among these, it is more preferable to use the corona discharge treatment method from the viewpoint of excellent adhesion to the smoothing layer 12 and easy treatment operation.

<Coating layer formation process>
In this step, first, a smoothing layer forming composition is prepared.

As the smoothing layer-forming composition, the active energy ray-curable compound as described above may be used alone. In addition to this, a composition for forming a smoothing layer in which a solvent and other components as described above are mixed as necessary may be used.

Next, a smoothing layer forming composition that forms a liquid is applied on the first surface 111 of the substrate 11. Thereby, a coating layer is obtained. As described above, since the smoothing layer-forming composition has an appropriate fluidity, by applying the smoothing layer-forming composition on the first surface 111 of the base material 11, The unevenness of the first surface 111 of the material 11 can be accurately embedded. As a result, it is possible to prevent the unevenness of the base material 11 from affecting the third surface 121 of the smoothing layer 12 and to smooth the third surface 121 of the smoothing layer 12.

Further, when the smoothing layer forming composition contains a solvent or the like, the smoothing layer forming composition is applied onto the first surface 111 of the substrate 11, and then the smoothing layer forming composition is dried. To obtain a coating layer. Thereby, a solvent can be removed by drying the composition for smoothing layer formation.

Examples of the method for applying the smoothing layer forming material include a gravure coating method, a bar coating method, a spray coating method, a spin coating method, an air knife coating method, a roll coating method, a blade coating method, a gate roll coating method, and a die coating. Law. Among these, the gravure coating method and the bar coating method are more preferable, and the bar coating method is more preferable. Thereby, the coating layer of the target thickness can be formed easily.

In addition, when the smoothing layer forming composition contains a solvent or the like, the method of drying the smoothing layer forming material is not particularly limited, and examples thereof include a method of drying in a hot air drying furnace.

Further, when the smoothing layer forming composition is dried, the drying conditions are not particularly limited. The drying temperature is preferably 50 to 100 ° C., and the drying time is preferably 5 seconds to 1 minute. Thereby, unintentional alteration of the smoothing layer 12 can be prevented, and the smoothing layer 12 can be formed particularly efficiently. As a result, productivity of the finally obtained release film 1 can be improved. Further, when the drying temperature is within the above range, particularly when the release agent layer forming composition contains a solvent or the like, the occurrence of warping or cracking of the smoothing layer 12 accompanied by evaporation of the solvent or the like at the time of drying. Can be prevented.

<Smoothing layer forming step>
Next, the smoothing layer 12 is formed by irradiating the application layer obtained by the application layer forming step with an activation energy ray and curing it.

In this step, the coating layer in which the unevenness of the first surface 111 of the substrate 11 is appropriately embedded in the coating layer forming step is cured while maintaining the smoothness of the outer surface. As a result, the smoothing layer 12 having a sufficiently smooth third surface 121 can be obtained. Thereby, the unevenness | corrugation of the 1st surface 111 of the base material 11 with respect to the outer surface 131 of the releasing agent layer 13 can be prevented. Therefore, the smoothness of the outer surface 131 of the release agent layer 13 can be made excellent in the release agent layer forming step described later.

The activation energy ray used for curing may be appropriately selected depending on the material contained in the smoothing layer forming composition to be used. For example, visible light, ultraviolet ray, infrared ray, X-ray, α ray, β Examples thereof include rays, γ rays, and electron beams. Among these, ultraviolet rays or visible rays are preferable.

The wavelength of the activation energy ray (ultraviolet light or visible light) is not particularly limited, but is preferably 200 to 600 nm, for example, and more preferably 250 to 450 nm. If the wavelength of the activation energy ray is within the above range, the coating layer can be uniformly cured while sufficiently shortening the curing time for curing the coating layer.

Further, the means for irradiating the activation energy ray (ultraviolet light or visible light) is not particularly limited, and various general means can be used. For example, a light source lamp such as a high-pressure mercury lamp, a metal halide lamp, or an excimer lamp can be used as the light source.

When activating energy rays (ultraviolet rays or visible rays) are irradiated, the irradiation amount of the activation energy rays is preferably 50 to 400 mJ / cm ² , and preferably 100 to 300 mJ / cm ^2. More preferred. When the irradiation amount of the activation energy ray is a value within the above range, the coating layer can be cured more uniformly and reliably.

The time for irradiating the activation energy ray is not particularly limited, but is preferably 5 seconds to 1 minute. Thereby, the smoothing layer 12 can be formed particularly efficiently. As a result, productivity of the finally obtained release film 1 can be improved.

<Release agent layer forming step>
Next, the release agent layer 13 is formed on the surface 121 side of the smoothing layer 12 opposite to the substrate 11.

As the release agent layer forming composition constituting the release agent layer 13, a composition in which the above-described materials are mixed is prepared.

Next, a liquid release agent layer forming composition is applied on the surface 121 of the smoothing layer 12 opposite to the substrate 11, and then dried and cured. Thereby, the release agent layer 13 is obtained.

The drying method is not particularly limited, and examples thereof include a drying method using a hot air drying furnace.

Also, the drying conditions are not particularly limited. The drying temperature is preferably 80 to 150 ° C., and the drying time is preferably 5 seconds to 1 minute. Thereby, unintentional alteration of the release agent layer 13 can be prevented, and the release agent layer 13 can be formed particularly efficiently. As a result, productivity of the finally obtained release film 1 can be improved.

According to the above process, the reliable peeling film 1 which is excellent in smoothness and excellent in peelability can be manufactured easily and reliably.

Further, if a green sheet is manufactured using such a release film 1, it is possible to prevent a pinhole or the like from being generated on the surface of the green sheet.

In addition, as a method of manufacturing a ceramic green sheet using the release film 1, for example, a ceramic powder-dispersed slurry is applied to the surface of the release agent layer of the release film and dried to form a green sheet. A method of forming an electrode on a ceramic sheet obtained by laminating the peeled green sheets to obtain a laminate and firing the laminate is exemplified. Thereby, a ceramic capacitor can be obtained. Thus, if a ceramic capacitor is formed with a green sheet formed using the release film 1, a highly reliable ceramic capacitor in which the occurrence of problems due to a short circuit is prevented can be obtained.

As mentioned above, although this invention was demonstrated in detail based on preferred embodiment, this invention is not limited to this.

For example, in the above-described embodiment, the base material has been described as having a single-layer structure, but the present invention is not limited to this, and the base material may have a multilayer structure of two or more layers of the same type or different types. In addition, the smoothing layer and the release agent layer are similarly described as having a single layer structure, but the present invention is not limited to this, and the smoothing layer and the release agent layer are each of the same or different two or more layers. It may have a multilayer structure.

In addition, for example, in the above-described embodiment, the green sheet manufacturing release film in which the smoothing layer is provided on the first surface of the base material has been described. However, the release film for producing a green sheet is not limited to this, and a smoothing layer or a release agent layer may be provided on the second surface side of the substrate.

Further, for example, in the above-described embodiment, the green sheet manufacturing release film has been described as having a three-layer structure in which a base material, a smoothing layer, and a release agent layer are laminated to be joined to each other in this order. However, the present invention is not limited to this, and an intermediate layer may be provided between the smoothing layer and the release agent layer. Moreover, you may provide an intermediate | middle layer between a base material and a smoothing layer. As such an intermediate layer, the adhesion between the smoothing layer and the release agent layer may be improved, and the occurrence of electrification when winding the release film for green sheet production before the green sheet is formed is further improved. It may be a layer to be suppressed.

Moreover, the manufacturing method of the peeling film for green sheet manufacture of this invention is not limited to the method mentioned above, Arbitrary processes may be added as needed.

Next, specific examples of the release film for producing a green sheet of the present invention will be described. However, the present invention is not limited to these examples.

[1] Production of release film for green sheet production (Example 1)
First, a biaxially stretched polyethylene terephthalate film as a substrate [thickness: 38 μm, arithmetic average roughness Ra ₂ of the first surface: 42 nm, maximum protrusion height Rp _{2 of} the first surface: 619 nm, of the second surface Arithmetic average roughness Ra ₃ : 42 nm, maximum protrusion height Rp ₃ : 619 nm on the second surface] was prepared.

Next, an ultraviolet curable compound mainly composed of a urethane acrylate oligomer as an active energy ray curable compound [Arakawa Chemical Industries, trade name “Beam Set 575CB”, solid content 100 mass%, mass average molecular weight 470, light Polymerization initiator contained] 100 parts by mass, toluene and methyl ethyl ketone were mixed to obtain a composition for forming a smoothing layer having a solid content of 20% by mass.

The obtained composition for forming a smoothing layer was applied to the first surface of the substrate with a Meyer bar # 4 and dried at 80 ° C. for 1 minute to obtain a coating layer.

Next, the coating layer was irradiated with ultraviolet rays (wavelength: 365 nm, irradiation amount: 200 mJ / cm ² ) with an ultraviolet irradiation device to form a smoothing layer (thickness: 1.3 μm).

Furthermore, 100 parts by mass of a mixture of an addition reaction type silicone compound as a release agent and a crosslinking agent [manufactured by Shin-Etsu Chemical Co., Ltd., trade name “silicone KS-847H”, solid content 30% by mass] with toluene was diluted. A dilution was obtained. 2 parts by mass of a platinum catalyst [trade name “PL-50T” manufactured by Shin-Etsu Chemical Co., Ltd.] was added to this diluted solution and mixed to obtain a composition for forming a release agent layer having a solid content of 1.5% by mass. It was. The release agent layer-forming composition was uniformly applied to the surface of the smoothing layer opposite to the substrate so that the thickness of the release agent layer-forming composition after drying was 0.1 μm. Thereafter, the release agent layer-forming composition was dried at 130 ° C. for 1 minute to form a release agent layer, thereby producing a release film for producing a green sheet.

(Example 2)
The biaxially stretched polyethylene terephthalate film of Example 1 was converted into a biaxially stretched polyethylene terephthalate film [thickness 31 μm, arithmetic mean roughness Ra ₂ of the first surface: 29 nm, maximum protrusion height Rp ₂ : 257 nm of the first surface, A release film for producing a green sheet was produced in the same manner as in Example 1 except that the arithmetic average roughness Ra ₃ of the second surface was 29 nm and the maximum protrusion height Rp _{3 was} 257 nm of the second surface. .

(Example 3)
The biaxially stretched polyethylene terephthalate film of Example 1 was converted into a biaxially stretched polyethylene terephthalate film [thickness 31 μm, arithmetic mean roughness Ra ₂ of the first surface: 15 nm, maximum projection height Rp _{2 of} first surface: 98 nm, Example 1 except that the arithmetic average roughness Ra ₃ of the second surface was changed to 15 nm and the maximum protrusion height Rp _{3 of} the second surface was 98 nm, and the thickness of the smoothing layer was changed to 0.4 μm. In the same manner as described above, a release film for producing a green sheet was produced.

Example 4
A release film for producing a green sheet was produced in the same manner as in Example 1 except that the thickness of the smoothing layer in Example 1 was changed to 1.8 μm.

(Example 5)
A release film for producing a green sheet was produced in the same manner as in Example 1 except that the thickness of the smoothing layer in Example 1 was changed to 2.3 μm.

(Comparative Example 1)
First, a biaxially stretched polyethylene terephthalate film as a substrate [thickness: 38 μm, arithmetic average roughness Ra ₂ of the first surface: 42 nm, maximum protrusion height Rp _{2 of} the first surface: 619 nm, of the second surface Arithmetic average roughness Ra ₃ : 42 nm, maximum protrusion height Rp ₃ : 619 nm on the second surface] was prepared.

Next, 100 parts by mass of a mixture of an addition reaction type silicone compound as a release agent and a crosslinking agent [manufactured by Shin-Etsu Chemical Co., Ltd., trade name “Silicone KS-847H”, solid content 30% by mass] with toluene is diluted. To obtain a diluted solution. 2 parts by mass of a platinum catalyst [trade name “PL-50T” manufactured by Shin-Etsu Chemical Co., Ltd.] was added to this diluted solution and mixed to obtain a composition for forming a release agent layer having a solid content of 1.5% by mass. It was. The release agent layer forming composition was uniformly applied on the first surface of the substrate so that the thickness of the release agent layer forming composition after drying was 0.1 μm. Thereafter, the release agent layer-forming composition was dried at 130 ° C. for 1 minute to form a release agent layer, thereby producing a release film for producing a green sheet.

(Comparative Example 2)
First, a biaxially stretched polyethylene terephthalate film as a substrate [thickness: 38 μm, arithmetic average roughness Ra ₂ of the first surface: 42 nm, maximum protrusion height Rp _{2 of} the first surface: 619 nm, of the second surface Arithmetic average roughness Ra ₃ : 42 nm, maximum protrusion height Rp ₃ : 619 nm on the second surface] was prepared.

Next, a mixture of a stearyl-modified alkyd compound and a methylated melamine compound as a thermosetting compound [manufactured by Hitachi Chemical Co., Ltd., trade name “Tesfine 303”, solid content 20 mass%, mass average molecular weight 15000] 100 mass Then, 3 parts by mass of p-toluenesulfonic acid as an acid catalyst, toluene and methyl ethyl ketone were mixed to obtain a composition for forming a smoothing layer having a solid content of 20% by mass. The obtained composition for smoothing layer formation was apply | coated to the 1st surface of a base material with Mayer bar # 4, and the coating layer was obtained.

Next, the coating layer was dried at 140 ° C. for 1 minute and heated to form a smoothing layer (thickness: 1.0 μm).

(Comparative Example 3)
Cationic polymerizable UV curable compound mainly composed of an epoxy-modified silicone compound as an active energy ray curable compound [“UV POLY200” manufactured by Arakawa Chemical Industries, Ltd., solid content concentration 100 mass%, mass average molecular weight 20000] 40 mass Part, 3 parts by mass of a boron-based cationic curing UV catalyst [“UV CAT A211” manufactured by Arakawa Chemical Co., Ltd., solid content 20%] as a catalyst, toluene, and methyl ethyl ketone are mixed to obtain a smooth content of 20% by mass. A release film for producing a green sheet was produced in the same manner as in Example 1 except that the composition for forming a chemical layer was obtained.

(Comparative Example 4)
First, a biaxially stretched polyethylene terephthalate film as a substrate [thickness: 38 μm, arithmetic average roughness Ra ₂ of the first surface: 42 nm, maximum protrusion height Rp _{2 of} the first surface: 619 nm, of the second surface Arithmetic average roughness Ra ₃ : 42 nm, maximum protrusion height Rp ₃ : 619 nm on the second surface] was prepared.

Next, 80 parts by mass of a polyester compound [manufactured by Toyobo Co., Ltd., trade name “Byron 20SS”, solid content 30 mass%, mass average molecular weight 3000] as a thermosetting compound, and methylated melamine 20 as a crosslinking agent A composition for forming a smoothing layer having a solid content of 20% by mass was obtained by mixing 3 parts by mass of p-toluenesulfonic acid as an acid catalyst, toluene, and methyl ethyl ketone.

The obtained composition for forming a smoothing layer was applied to the first surface of the substrate with a Meyer bar # 4 to obtain a coating layer.

Next, the coating layer was dried at 130 ° C. for 1 minute and heated to form a smoothing layer (thickness: 1.2 μm).

(Comparative Example 5)
An ultraviolet curable compound mainly composed of an acrylate oligomer as an active energy ray curable compound [“8KX-012C” manufactured by Taisei Fine Chemical Co., Ltd., solid content concentration 40 mass%, mass average molecular weight 25000] is diluted with toluene, A release film for producing a green sheet was produced in the same manner as in Example 1 except that a composition for forming a smoothing layer having a solid content of 20% was obtained.

Table 1 summarizes the configurations and the like of the release films for producing green sheets of each Example and each Comparative Example.

In the table, an ultraviolet curable compound having a urethane acrylate oligomer as a main component as an active energy ray curable compound [manufactured by Arakawa Chemical Industry Co., Ltd., trade name “Beam Set 575CB”, solid content 100 mass%, mass average molecular weight 470 ] “A1”, a mixture of a stearyl-modified alkyd compound as a thermosetting compound and a methylated melamine compound [manufactured by Hitachi Chemical Co., Ltd., trade name “Tesfine 303”, solid content 20 mass%, mass average molecular weight 15000 ] “A2”, a cationic polymerizable ultraviolet curable compound mainly composed of an epoxy-modified silicone compound as an active energy ray curable compound [“UV POLY200” manufactured by Arakawa Chemical Industries, Ltd., solid content concentration: 100 mass%, mass Average molecular weight 20000] is "A3" Ester compound [Toyobo Co., Ltd., trade name “Byron 20SS”, solid content 30% by mass, mass average molecular weight 3000] is “A4”, UV curing mainly composed of acrylate oligomer as active energy ray curable compound Type compound [“8KX-012C” manufactured by Taisei Fine Chemical Co., Ltd., solid concentration: 40 mass%, mass average molecular weight: 25000] was designated as “A5”.

Further, the film thicknesses of the base material, the smoothing layer and the release agent layer in each Example and each Comparative Example were measured with a reflective film thickness meter “F20” [manufactured by Filmetrics Co., Ltd.]

Further, the arithmetic average roughness Ra ₂ and the maximum protrusion height Rp ₂ of the first surface of the base material, the arithmetic average roughness Ra ₃ and the maximum protrusion height Rp ₃ of the second surface of the base material, and the smoothing layer The arithmetic average roughness Ra ₄ and maximum protrusion height Rp _{4 of} the third surface, and the arithmetic average roughness Ra ₁ and maximum protrusion height Rp ₁ of the outer surface of the release agent layer were measured as follows, respectively. . First, a double-sided tape was affixed to a glass plate. Next, the release film for green sheet production obtained in each example and each comparative example is placed on a double-sided tape so that the surface opposite to the surface on which the arithmetic average roughness and maximum protrusion are measured is the glass plate side. And fixed. Thus, the arithmetic average roughness Ra ₂ , Ra ₃ , Ra ₄ , Ra ₁ , and the maximum protrusion height Rp ₂ , Rp ₃ , Rp ₄ , Rp ₁ are measured according to JIS B0601-1994. Measured with a measuring instrument SV3000S4 (stylus type).

[2] Evaluation Regarding the release film for producing a green sheet obtained as described above, the following evaluation was performed.

[2.1] Evaluation of blocking property The release film for green sheet production obtained in each Example and each Comparative Example was rolled up into a roll having a width of 400 mm and a length of 5000 m to obtain a release film roll. This release film roll was stored for 30 days in an environment of 40 ° C. and a humidity of 50% or less. Thereafter, the appearance of the release film roll was visually observed, and the blocking property was evaluated according to the following criteria.

A: Compared with the appearance of the release film roll before storage obtained by rolling up the release film for green sheet production into a roll, there was no change in the appearance of the release film roll after storage (no blocking).
B: In the release film roll for producing a green sheet, there was a region in which the color was partially different (those that have a blocking tendency can be used).
C: The color was different over a wide area of the release film roll for producing a green sheet (with blocking).
When blocking occurs due to adhesion between the front and back surfaces of the release film for green sheet production as in the above standard C, and the color changes over a wide area of the release film roll, the release film for green sheet production is normally unwound. May not be possible.

[2.2] Evaluation of the number of recesses A release film for green sheet production obtained in each example and each comparative example was obtained by using a coating solution obtained by dissolving polyvinyl butyral resin in a toluene / ethanol mixed solvent (mass ratio 6/4). On the release agent layer (outer surface), a coating layer was obtained by coating so that the thickness after drying was 3 μm. The coating layer 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 for green sheet production was peeled from the polyvinyl butyral resin layer, and the polyvinyl butyral resin layer was transferred to a polyester tape. Next, the surface of the polyvinyl butyral resin layer that had been in contact with the release agent layer of the release film for producing a green sheet was observed using an optical interference type surface shape observation device “WYKO-1100” [manufactured by Veeco Corporation]. The observation conditions were PSI mode and 50 magnification. In the range of 91.2 × 119.8 μm of the surface of the polyvinyl butyral resin layer, the number of recesses confirmed on the surface of the polyvinyl butyral resin layer was counted. The concave portion had a depth of 150 nm or more to which the shape of the release agent layer was transferred. The number of recesses was evaluated according to the following criteria. In addition, when the capacitor was produced using the polyvinyl butyral resin layer (green sheet) evaluated as the following standard C, there was a tendency for a short circuit to occur due to a decrease in withstand voltage.

A: The number of recesses is zero.
B: The number of recesses is 1 to 5.
C: The number of recesses is 6 or more.
These results are shown in Table 2.

As is apparent from Table 2, the release film for producing a green sheet of the present invention was excellent in the smoothness of the outer surface. Moreover, the coarse recessed part etc. were hardly confirmed by the green sheet formed using the peeling film for green sheet manufacture of this invention. Moreover, generation | occurrence | production of malfunctions, such as a short circuit, was not confirmed by the ceramic capacitor manufactured with the green sheet formed using the peeling film for green sheet manufacture of this invention. On the other hand, satisfactory results were not obtained in the comparative example.

The release film for producing a green sheet of the invention is a substrate having a first surface and a second surface, a smoothing layer provided on the first surface of the substrate, and a substrate opposite to the smoothing layer. The smoothing layer is formed by irradiating the active energy ray-curable composition containing the active energy ray-curable compound with an active energy ray and curing the composition. The arithmetic average roughness Ra ₁ of the outer surface of the release agent layer is 8 nm or less, and the maximum protrusion height Rp _{1 of the} outer surface of the release agent layer is 50 nm or less. ADVANTAGE OF THE INVENTION According to this invention, it can prevent that a pinhole etc. generate | occur | produce on the surface of a green sheet, and can provide the peeling film for green sheet manufacture which can manufacture a reliable green sheet. Therefore, the present invention has industrial applicability.

DESCRIPTION OF SYMBOLS 1 ... Release film 11 for green sheet manufacture ... Base material 111 ... 1st surface 112 of a base material ... 2nd surface 12 of a base material 12 ... Smoothing layer 121 ... Surface (Third aspect)
13 ... Release agent layer 131 ... Outer surface of release agent layer

Claims

A release film for producing green sheets,
A substrate having a first surface and a second surface;
A smoothing layer provided on the first surface of the substrate;
A release agent layer provided on the surface side opposite to the base material of the smoothing layer,
The smoothing layer is formed by irradiating and curing an active energy ray on a composition for forming a smoothing layer containing an active energy ray-curable compound,
An arithmetic average roughness Ra 1 of the outer surface of the release agent layer is 8 nm or less, and a maximum protrusion height Rp 1 of the outer surface of the release agent layer is 50 nm or less. Release film.
2. The green sheet manufacturing release according to claim 1, wherein the arithmetic mean roughness Ra 2 of the first surface is 10 to 200 nm, and the maximum protrusion height Rp 2 of the first surface is 80 to 1000 nm. the film.
The release film for producing a green sheet according to claim 1 or 2, wherein the active energy ray-curable compound is a compound having a mass average molecular weight of 950 or less.
The release film for producing a green sheet according to any one of claims 1 to 3, wherein the active energy ray-curable compound is an ultraviolet ray curable compound, and the active energy ray is an ultraviolet ray.
The release film for producing a green sheet according to any one of claims 1 to 4, wherein an average film thickness of the smoothing layer is 0.2 to 10 µm.
The smoothing layer has a surface opposite to the substrate;
The arithmetic average roughness Ra 4 of the surface of the smoothing layer opposite to the base material is 8 nm or less, and the maximum protrusion height Rp 4 of the surface of the smoothing layer opposite to the base material is 50 nm. The release film for producing a green sheet according to any one of claims 1 to 5, which is as follows.
7. The arithmetic mean roughness Ra 3 of the second surface is 10 to 200 nm, and the maximum protrusion height Rp 3 of the second surface is 80 to 1000 nm. The release film for green sheet manufacture as described.
It is a manufacturing method of the peeling film for green sheet manufacture of any one of Claim 1 thru | or 7, Comprising:
A base material preparing step of preparing the base material having the first surface and the second surface;
A coating layer forming step of forming a coating layer by coating the smoothing layer forming composition containing the active energy ray-curable compound on the first surface side of the substrate;
A smoothing layer forming step of forming the smoothing layer by irradiating and curing the active energy ray on the coating layer;
A release agent layer forming step of forming the release agent layer on the surface side of the smoothing layer opposite to the substrate;
The arithmetic average roughness Ra 1 of the outer surface of the release agent layer is 8 nm or less, and the maximum protrusion height Rp 1 of the outer surface of the release agent layer is 50 nm or less. A method for producing a release film for producing a green sheet.