KR20150132229A - Release film for green sheet manufacturing, and method for manufacturing release film for green sheet manufacturing - Google Patents

Abstract

A release film for manufacturing a green sheet of the present invention comprises: a substrate having a first side and a second side; A smoothing layer formed on the first surface; And a release agent layer formed on the side of the smoothing layer opposite to the substrate, wherein the smoothing layer is formed by heating and curing a composition for smoothing layer formation including a thermosetting compound having a mass average molecular weight of 950 or less, and the arithmetic average roughness Ra of the outer surface of the layer ₁ than 8nm, and also characterized in that the maximum is not more than 50nm projection height Rp _1. INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a release film for use in the production of a green sheet, which can prevent the generation of pinholes on the surface of a green sheet and can produce a green sheet with high reliability.

Description

TECHNICAL FIELD [0001] The present invention relates to a release film for manufacturing a green sheet and a method for manufacturing a release film for use in the production of a green sheet. BACKGROUND OF THE INVENTION 1. Field of the Invention [0002]

The present invention relates to a release film for the production of green sheets and a process for producing release films for the production of green sheets.

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

The release film for green sheet production generally comprises a substrate and a release agent layer. The 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 a release film for producing such a green sheet, and drying the green sheet. In addition, the green sheet thus produced is peeled off from the release film for the production of a green sheet, and is used in the production of a ceramic capacitor.

In the conventional production of a green sheet using a release film for green sheet production, unevenness on the surface of the release film for production of a green sheet is transferred to the green sheet, resulting in pinholes on the surface of the green sheet. As a result, in the ceramic capacitor produced by laminating such a green sheet, there arises a problem that short-circuit problems arise. In order to solve such a problem, a very high smoothness is required on the surface (cast surface) of the release film for green sheet production.

Accordingly, a method for producing a release film for surface-smoothening a green sheet, comprising the steps of applying a thermosetting resin liquid onto one surface of a substrate sheet having fine irregularities on its surface and heating and curing the thermosetting resin liquid to form a thermosetting resin layer And then a releasing agent is coated on the thermosetting resin layer to form a releasing agent layer (see, for example, Patent Document 1).

Further, with the recent miniaturization and high density of the ceramic capacitor, further thinning of the green sheet is required. However, in the conventional release film for green sheet production, when a thin green sheet is produced, pinholes and the like are generated on the surface of the green sheet, and it is difficult to obtain a reliable green sheet.

Japanese Patent Application Laid-Open No. 2007-069360

SUMMARY OF THE INVENTION An object of the present invention is to provide a release film for use in the production of a green sheet, which can prevent a pinhole or partial thickness variation on the surface of a green sheet from occurring, and can produce a highly reliable green sheet. Another object of the present invention is to provide a method for manufacturing a release film for use in the production of a green sheet, which can prevent pinholes and partial thickness variations on the surface of the green sheet.

This object is achieved by the present invention of the following (1) to (7).

(1) a release film for manufacturing a green sheet,

A substrate having a first side and a second side;

A smoothing layer formed on the first surface side of the substrate; And

And a release agent layer formed on the side of the smoothing layer opposite to the substrate,

Wherein the smoothing layer is formed by heating and curing a composition for forming a smoothing layer containing a thermosetting compound having a mass average molecular weight of 950 or less,

And the arithmetic average roughness Ra ₁ of the outer surface of the release agent layer 8nm or less, as well as the green sheet for manufacture of release film is the maximum protrusion height Rp ₁ of the outer surface of the release agent layer, characterized in that not more than 50nm.

(2) The release film for producing a green sheet according to (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.

(3) The release film for producing a green sheet according to (1) or (2), wherein the smoothening layer has an average thickness of 0.2 to 10 탆.

(4) The release film for producing a green sheet according to any one of (1) to (3), wherein the thermosetting compound is a bisphenol-type epoxy compound.

(5) the smoothing layer has an opposite surface to the substrate, the arithmetic average roughness Ra ₄ of the surface opposite to the substrate of the smoothing layer is 8 nm or less, and the surface of the smoothing layer opposite to the substrate (1) to (4), wherein the maximum projecting height Rp ₄ of the green sheet is 50 nm or less.

(6) The green sheet according to any one of (1) to (5) above, wherein 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. Release film for manufacture.

(7) A method for producing a release film for manufacturing a green sheet according to any one of (1) to (6)

A substrate preparation step of preparing the substrate having the first surface and the second surface,

A coating layer forming step of forming the coating layer by applying the composition for forming a smoothing layer containing the thermosetting compound having a mass average molecular weight of 950 or less to the first surface side of the substrate,

A smoothing layer forming step of forming the smoothing layer by heating and curing the coating layer, and

And a releasing agent layer forming step of forming the releasing agent layer on the surface side of the smoothing layer opposite to the substrate,

Wherein the outside the arithmetic average roughness Ra ₁ of the surface of the release agent layer is not more than 8nm, as well as green method of producing a sheet for making a release film has the maximum protrusion height Rp ₁ of the outer surface of the release agent layer, characterized in that not more than 50nm.

According to the present invention, it is possible to provide a release film for use in the production of a green sheet, which can prevent a pinhole or partial thickness variation on the surface of a green sheet from occurring and provide a highly reliable green sheet. Particularly, even when a substrate having a relatively large surface roughness is used as a substrate constituting a release film for green sheet production, it is possible to provide a release film for use in the production of a green sheet excellent in smoothness on the outer surface. By using this release film for green sheet production, it is possible to prevent the occurrence of pinholes and partial thickness variations on the surface of the green sheet. As a result, when a green sheet is laminated to manufacture a capacitor, it is possible to prevent a problem caused by a short circuit. Further, according to the present invention, it is possible to easily and reliably produce a release film for production of a green sheet, which can produce a green sheet excellent in surface smoothness.

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

Hereinafter, the present invention will be described in detail based on preferred embodiments.

<< Release Film for Green Sheet >>

The release film for the production of a green sheet of the present invention is used for producing a green sheet. The green sheet thus produced is used, for example, for the production of ceramic capacitors and the like.

1 is a cross-sectional view of a release film for the production of a green sheet of the present invention. In the following description, the upper side in Fig. 1 is referred to as &quot; upper &quot; and the lower side is referred to as &quot; lower &quot;.

As shown in Fig. 1, the release film 1 for manufacturing a green sheet has a substrate 11 having a first side 111 and a second side 112; A smoothing layer (12) formed on the first side (111) of the substrate (11); And a release agent layer 13 formed on the side of the smoothing layer 12 opposite to the substrate 121 (hereinafter also referred to as &quot; third surface 121 &quot;). That is, the release film 1 for green sheet production has a three-layer structure in which the base material 11, the smoothing layer 12, and the release agent layer 13 are laminated in this order, as shown in Fig.

In the present specification, in the case of producing a green sheet using the release film 1 for manufacturing a green sheet, the green sheet can be obtained by, for example, applying the dissolved ceramic slurry on the outer surface 131 of the release agent layer 13 .

In the present invention, the release film (1) for green sheet production has a smoothing layer (12) between the substrate (11) and the release agent layer (13). In the release film (1) for manufacturing a green sheet of the present invention, the smoothing layer (12) is formed by heating and curing a composition for smoothing layer formation containing a thermosetting compound having a predetermined mass average molecular weight of 950 or less, and the arithmetic average roughness Ra of the layer ₁ (13) the outer surface 131 of 8nm or less, as well as a maximum protrusion height Rp ₁ of the outer surface 131 of the release agent layer 13 has a feature in that not more than 50nm.

By virtue of this feature, the release film 1 for manufacturing a green sheet having excellent smoothness on the outer surface 131 of the release agent layer 13 and excellent in peelability can be obtained. When the green sheet is produced by using the release film 1 for manufacturing a green sheet, it is possible to prevent pinholes and partial thickness variations on the surface of the green sheet, and a highly reliable green sheet can be produced. As a result, when a green sheet is laminated to manufacture a capacitor, it is possible to prevent a problem caused by a short circuit.

However, the film used as a substrate has various surface roughnesses. The lower the film, the rougher the surface roughness tends to be. Even when such a surface roughness forms a release film for production of a green sheet using a relatively coarse substrate, the smoothing layer having the above-described characteristics is formed on the surface of the substrate, so that irregularities on the surface of the substrate can be accurately buried (offset) . As a result, the surface opposite to the substrate of the smoothing layer can be smoothed. Thus, it is possible to prevent the unevenness of the surface of the substrate from affecting the outer surface of the release agent layer formed on the smoothing layer, and to obtain a release film for use in the production of a green sheet excellent in smoothness of the outer surface of the release agent layer.

Hereinafter, each layer constituting the release film 1 for green sheet production according to the present embodiment will be sequentially described.

&Lt; Substrate (11) >

The base material has a function of imparting physical strength such as rigidity and flexibility to the release film 1 for green sheet production (hereinafter, simply referred to as "release film 1").

The substrate 11 has a first surface 111 and a second surface 112, as shown in Fig.

The material constituting the base material 11 is not particularly limited and examples thereof include polyester resins such as polybutylene terephthalate resin, polyethylene terephthalate resin and polyethylene naphthalate resin, polypropylene resin, polymethylpentene resin, etc. Polyolefin resin of polycarbonate, and plastic such as polycarbonate. The base material 11 may be a single layer film, and may be a multilayer film of two or more layers of the same or different types. Among these, a polyester film is preferable, a polyethylene terephthalate film is more preferable, and a biaxially oriented polyethylene terephthalate film is more preferable. Particularly, the polyester film is less prone to dust and the like during processing and use. Therefore, when the green sheet is produced by using, for example, the release film (1) produced by using a polyester resin, defective application of the ceramic slurry by dust or the like can be effectively prevented. As a result, a green sheet having fewer pinholes can be produced.

The base material 11 may contain a filler or the like in addition to the above-described materials. Examples of the filler include silica, titanium oxide, calcium carbonate, kaolin, and aluminum oxide. One or more of these fillers may be used in combination. By including such a filler, mechanical strength is imparted to the base material 11, slipperiness of the front and back surfaces of the base material 11 is improved, and blocking can be suppressed.

In addition, the base 11 has a first surface, and the arithmetic average roughness Ra ₂ is 10 ~ 200nm (111), and also it is preferred that the maximum projection height Rp ₂ is 80 ~ 1000nm.

In particular, the arithmetic average roughness Ra ₂ of the first surface 111 is more preferably 15 to 100 nm, and the arithmetic mean roughness Ra ₂ of the first surface 111 is more preferably 20 to 50 nm. It is more preferable that the maximum protrusion height Rp ₂ of the first surface 111 is 90 to 800 nm and the maximum protrusion height Rp ₂ of the first surface 111 is 100 to 600 nm.

Of the first surface 111, the arithmetic mean roughness Ra ₂ and the maximum protrusion height Rp ₂ is a first side 111 of the range, also the thickness of the smoothing layer 12 to be described later is relatively thin and if the base 11 of The irregularities can be more preferably embedded, and the smoothing layer 12 can be smoother on the opposite surface 121 of the substrate 11. As a result, it is possible to further prevent the unevenness of the first surface 111 of the substrate 11 from being influenced by the outer surface 131 of the release agent layer 13 formed on the smoothing layer 12.

The substrate 11 having the arithmetic average roughness Ra ₂ of the first surface 111 and the maximum projection height Rp ₂ within the above range is relatively inexpensive and readily available.

If the arithmetic average roughness Ra ₂ of the first surface 111 exceeds the upper limit, it is difficult to sufficiently fill the unevenness of the first surface 111, depending on the constituent materials of the composition for smoothing layer formation, It may be necessary to increase the thickness of the base material 13 relatively.

In addition, the present specification, as determined by the first surface 111, the arithmetic mean roughness Ra ₂ and the maximum protrusion height Rp ₂ is honey Toyo Co., Ltd. The surface roughness meter SV3000S4 (stylus) in accordance with JIS B0601-1994 of the base 11 It is a value that can be obtained. In this specification, unless otherwise specified, the "arithmetic mean roughness and maximum protrusion height" refers to a value obtained by the measurement as described above.

It is preferable that the substrate 11 has an arithmetic mean roughness Ra ₃ of 10-200 nm and an maximum projection height Rp ₃ of 80-1000 nm on the second surface 112. More preferably, the second surface 112 has an arithmetic mean roughness Ra ₃ of 15 to 100 nm, and the second surface 112 has an arithmetic mean roughness Ra ₃ of 20 to 50 nm. In addition, the second surface is more preferable that the maximum protrusion height Rp of ₃ 112 90 ~ 800nm, and the second surface is more preferred that the 112 maximum protrusion height Rp ₃ is 100 ~ 600nm of.

If 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 to prevent the occurrence of winding deviation or the like when the peeling film 1 is wound in roll form can do. Further, it is possible to prevent the occurrence of blocking when the peeling film 1 is rolled up and stored. Concretely, the release film 1 may be rolled into a core material such as paper, plastic or metal, if necessary, and stored. At this time, if the arithmetic average roughness Ra ₃ of the second surface 112 and the maximum protrusion height Rp _{3 thereof} fall within the above range, the air discharge is good when the release film 1 is rolled up, The winding displacement can be effectively suppressed. Therefore, when the release film 1 is wound, it is not necessary to increase the winding tension, and deformation of the winding core due to the winding tension can be suppressed. If the arithmetic average roughness Ra ₃ and the maximum protrusion height Rp ₃ of the second surface 112 of the roll-shaped peeling film 1 are within the above ranges, the peeling agent layer 13 and the substrate 11 It is possible to more effectively prevent the occurrence of blocking caused by the close contact of the second surface 112 of the substrate 110. [ For this reason, the roll-shaped release film 1 can be easily supplied.

On the other hand, when the arithmetic average roughness Ra ₃ of the second surface 112 is less than the lower limit, the surface of the release film 1 (the second surface 112 of the base material 11 and the release agent layer (The outer surface 131 of the outer tube 13).

The average thickness of the base material 11 is not particularly limited, but is preferably 10 to 300 占 퐉, more preferably 15 to 200 占 퐉. As a result, it is possible to make the peeling film 1 particularly resistant to tearing, breaking, etc., while making the flexibility of the peeling film 1 suitable.

<Smoothing layer 12>

The smoothing layer 12 has a function of reducing the influence of the unevenness of the first surface 111 of the base material 11 with respect to the outer surface 131 of the release agent layer 13. [

As shown in Fig. 1, the smoothing layer 12 is formed on the first surface 111 of the substrate 11.

The smoothing layer 12 is composed of a composition for forming a smoothing layer containing a predetermined thermosetting compound. The smoothing layer 12 is formed by heating and curing the smoothing layer forming composition.

The composition for forming a smoothing layer includes a thermosetting compound having a mass average molecular weight of 950 or less as described above. Particularly, a thermosetting compound having a mass average molecular weight of 300 to 700 is preferred. Thus, the viscosity of the composition for forming a smoothing layer before application to the first surface 111 of the base material 11 can be suitably adjusted, and the composition for smoothing layer has appropriate fluidity. By forming the smoothing layer 12 on the first surface 111 side of the substrate 11 by using the composition for smoothing layer formation as described above, the irregularities of the first surface 111 of the substrate 11 are preferably embedded can do. As a result, it is possible to prevent the irregularities 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 have. Therefore, it is possible to prevent the unevenness of the base material 11 from affecting the outer surface 131 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 smoothed.

Particularly, the irregularities of the surface of the first surface 111 of the substrate 11 are relatively large, and the irregularities of the first surface 111 are preferably formed by the action and effect of the composition for forming a smoothing layer, The release film 1 excellent in the smoothness of the outer surface 131 of the release agent layer 13 can be obtained.

On the contrary, when the mass average molecular weight of the thermosetting compound exceeds the upper limit, the fluidity of the composition for forming a smoothing layer is lowered and the smoothing layer 12 is formed along the concave and the convex of the first surface 111 of the substrate 11 There is a concern. As a result, the third surface 121 of the smoothing layer 12 is likely to follow the irregularities of the first surface of the substrate 11.

Examples of the thermosetting compound having a weight average molecular weight within the above range include bisphenol A epoxy compounds, bisphenol A epoxy compounds, bisphenol F epoxy compounds and bisphenol F epoxy ester compounds, melamine An isocyanate compound, a urethane compound, an acryl compound, a phenol compound, an alkyd compound, and a polyester compound, in addition to an amino compound such as a urethane compound and an urea compound. Among these, a bisphenol-type epoxy compound is preferable, and a bisphenol A-type epoxy ester compound is more preferable. This makes it possible to more easily and reliably fill the irregularities on the surface of the first surface 111 of the base material 11 and to make the curability particularly excellent even in the smoothing layer 12 having a relatively thin thickness.

The composition for forming a smoothing layer includes a thermosetting compound having a mass average molecular weight within the above range, but may contain a solvent as required. This makes it possible to easily adjust the viscosity of the composition for forming a smoothing layer when it is applied to the first surface 111 of the base material 11.

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 aliphatic hydrocarbons such as hexane and heptane. And one or more of these may be used in combination. This makes it easy to apply the composition for forming a smoothing layer to the first surface 111 of the base material 11 and adjust the viscosity before heating.

The composition for forming a smoothing layer may contain other components in addition to the above-described components. 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 composition for forming a smoothing layer (in terms of solid content) is preferably 0.1 to 10% by mass.

The content of the thermosetting compound in the composition for forming a smoothing layer containing a solvent is not particularly limited, but is preferably 0.5 to 60 mass%, more preferably 1 to 45 mass%. As a result, it becomes easy to make the viscosity of the composition for smoothing layer appropriate.

The content of the thermosetting 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. As a result, the curing property of the composition for forming a smoothing layer can be made particularly excellent.

It is also preferable that the arithmetic average roughness Ra ₄ of the third surface 121 of the smoothing layer 12 is 8 nm or less and the maximum projection height Rp ₄ is 50 nm or less. Particularly, it is preferable that the arithmetic average roughness Ra ₄ of the third surface 121 is 6 nm or less. It is preferable that the maximum projection height Rp ₄ of the third surface 121 is 40 nm or less.

If the arithmetic mean roughness Ra ₄ and the maximum protrusion height Rp ₄ of the third surface 121 are within the above range, the effect of the unevenness of the surface of the base material 11 with respect to the outer surface 131 of the release agent layer 13 is more preferable .

On the other hand, if the arithmetic average roughness Ra ₄ of the third surface 121 is less than the lower limit, there is a possibility that the adhesion with the releasing agent layer 13 may deteriorate depending on the material of the smoothing layer 12 and the like. On the other hand, when the arithmetic average roughness Ra ₄ of the third surface 121 exceeds the upper limit value, a new smoothing layer may need to be further formed between the release agent layer 13 and the smoothing layer 12.

When the maximum projection height Rp ₄ of the third surface 121 is less than the lower limit described above, adhesion is improved on the third surface 121 of the smoothing layer 12 in order to improve the adhesion with the release agent layer 13 There is a case that it is necessary to perform a process for making On the other hand, when the maximum protrusion height Rp ₄ of the third surface 121 exceeds the upper limit value, a new smoothing layer needs to be further formed between the release agent layer 13 and the smoothing layer 12.

The average thickness of the smoothing layer 12 is not particularly limited, but is preferably 0.2 to 10 탆, more preferably 0.3 to 5 탆. This makes it possible to more accurately fill the irregularities of the first surface 111 of the base material 11 and to further improve the smoothness of the outer surface of the release film 1. [ In addition, the flexibility of the smoothing layer 12 can be made moderate.

On the other hand, if the average thickness of the smoothing layer 12 is less than the lower limit described above, in order to sufficiently fill the unevenness of the first surface 111 of the substrate 11 depending on the components constituting the smoothing layer forming composition, It may be necessary to use a surface 111 having a relatively small surface roughness. If the average thickness of the smoothing layer 12 exceeds the upper limit, curling of the peeling film 1 is likely to occur due to the shrinkage of the smoothing layer 12 due to the components constituting the smoothing layer forming composition and the like , The handling properties of the release film 1 may be lowered.

&Lt; Release agent layer (13) >

The release agent layer 13 has a function of imparting releasability to the release film 1.

The release agent layer 13 is formed on the third surface 121 side of the smoothing layer 12 as shown in Fig.

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

Such a composition for forming a release agent layer includes a release agent.

Examples of the releasing agent include an alkyd compound, an acrylic compound, a silicone compound, a compound containing a long-chain alkyl group, a fluorine compound, and the like. One or more of these may be used in combination. Among them, it is preferable to use an alkyd compound, an acrylic compound, a silicone compound, or a compound containing a long-chain alkyl group. As a result, the release agent layer 13 having excellent curability and particularly excellent releasability to the green sheet can be obtained.

Specific examples of the alkyd compound include modified compounds 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 composition for forming a release agent layer. The release agent layer 13 having an alkyd-based compound having a crosslinked structure can be obtained by such a method of heat-curing the composition for forming a release agent layer.

Specific examples of the acrylic compound include modified compounds such as long-chain alkyl-modified acrylic compounds and silicone-modified acrylic compounds. When the composition for forming a release agent layer contains an acrylic compound, a crosslinking agent or a catalyst may be further added to the composition for forming a release agent layer. The release agent layer 13 having an acrylic compound having a crosslinked structure can be obtained by such a method of heating and curing the composition for forming a release agent layer.

Specific examples of the silicone compound include a silicone compound having a dimethylpolysiloxane as a basic skeleton. Examples of the silicone compound include an addition reaction type, a condensation reaction type, an ultraviolet ray hardening type, and an electron ray hardening 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 merits such as a small change in the peeling force after production and no hardening shrinkage, and therefore, it is preferable to use the addition reaction type silicone compound as a releasing agent constituting the releasing agent layer 13 .

Specific examples of the addition reaction type silicone compound include an organopolysiloxane having at least two alkenyl groups of 2 to 10 carbon atoms such as a vinyl group, allyl group, propenyl group and hexenyl group at the molecular terminal and / or side chain of the compound . 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 organopolysiloxanes having a hydrogen atom bonded to at least two silicon atoms in one molecule, specifically, a dimethylhydroxysiloxy terminated dimethylsiloxane-methylhydrogosiloxane copolymer, a trimethylsiloxy terminated polysiloxane Dimethylsiloxane-methylhydrogensiloxane copolymer, trimethylsiloxy-terminated methylhydrogenpolysiloxane, poly (hydroxysiloxane), and the like.

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

Examples of the long chain alkyl group-containing compound include polyvinyl carbamates obtained by reacting a polyvinyl alcohol polymer with a long chain alkyl isocyanate having 8 to 30 carbon atoms, and long chain alkyl isocyanates having 8 to 30 carbon atoms with polyethyleneimine Alkyl urea derivatives and the like.

Specific examples of the fluorine compound include a fluorine silicone compound, a fluorine boron compound, and the like.

The composition for forming a release agent layer may contain, in addition to the above-mentioned release agent, a dispersion medium and a solvent. By including at least one of the dispersion medium and the solvent, the viscosity of the composition for forming a release agent layer can be appropriately adjusted before coating and drying on the third surface 121 of the smoothing layer 12.

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

The composition for forming a release agent layer may contain other components in addition to the above-mentioned components. Other components include, for example, catalysts, dyes, dispersants, antistatic agents, and curing agents. When the other components are included, the content of the other components in the composition for forming a release agent layer is preferably 0.1 to 10% by mass.

In addition, the outer surface 131 of the release agent layer 13 as described above is less than the arithmetic mean roughness Ra ₁ 8nm, as well as that the maximum projection height Rp ₁ is 50nm or less. In particular, it is preferable that the arithmetic average roughness Ra ₁ of the outer surface 131 of the release agent layer 13 is less than or equal to 6nm. In addition, it is preferred that the maximum protrusion height Rp ₁ of the outer surface 131 of the release agent layer 13 is not more than 40nm.

The average roughness Ra ₁ and the maximum protrusion height arithmetic Rp ₁ of the outer surface 131 of the release agent layer (13), is in the above range, when forming a green sheet, a surface shape having a relatively high smoothness of the outer surface 131 It is possible to more preferably prevent pinholes and the like from being generated on the surface of the green sheet by being transferred to the green sheet. As a result, a green sheet having a surface with a higher level of smoothness can be obtained.

The release agent layer 13 preferably has an average thickness of 0.01 to 3 占 퐉, more preferably 0.03 to 1 占 퐉. If the thickness of the release agent layer 13 is less than 0.01 탆, the function as the release agent layer may not be sufficiently exhibited depending on the material constituting the release agent layer 13, etc. On the other hand, if the thickness of the release agent layer 13 is more than 3 占 퐉, blocking may easily occur when the release film 1 is rolled up in a roll form, 1) in the case where the recording paper is fed out is increased.

&Lt; Production method of release film for green sheet production &gt;

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

The method of producing the release film (1) of the present embodiment includes a substrate preparation step of preparing the substrate (11); A coating layer forming step of forming a coating layer by applying a composition for forming a smoothing layer containing a predetermined thermosetting compound to the first surface 111 of the substrate 11 and drying the same; A smoothing layer forming step of forming the smoothing layer 12 by heating and hardening the coating layer; And a releasing agent layer forming step of forming a releasing agent layer 13 on the side of the smoothing layer 12 opposite to the base material 11 side.

Hereinafter, each step will be described in detail.

<Substrate Preparation Process>

First, the substrate 11 is prepared.

As the substrate 11, a substrate 11 having the above-described structure can be used.

Further, the first surface 111 of the substrate 11 can be subjected to a surface treatment by an oxidation method or the like or a primer treatment. This makes the adhesion between the base material 11 and the smoothing layer 12 provided on the first surface 111 side of the base material 11 particularly excellent.

The surface treatment by the oxidation method or the like may be appropriately selected depending on the kind of the base material 11 and the like. Examples thereof include a corona discharge treatment, a plasma discharge treatment, a chromium oxidation treatment (wet type), a flame treatment, a hot air treatment, an ozone treatment, and an ultraviolet ray irradiation treatment. Among these, corona discharge treatment is more preferable because of its excellent adhesion with the smoothing layer 12 and easy handling.

<Coating Layer Forming Step>

In this step, first, a composition for forming a smoothing layer is prepared.

As the composition for forming the smoothing layer, the above-mentioned thermosetting compound may be used alone. In addition to this, if necessary, a composition for forming a smoothing layer mixed with a solvent or other components as described above may be used.

Next, a composition for forming a smoothing layer is applied on the first surface 111 of the substrate 11. Thus, a coated layer is obtained. The composition for forming a smoothing layer is coated on the first surface 111 of the substrate 11 and dried to form the first surface 111 of the substrate 11, The concavities and convexities of the concave portion 111 are accurately buried, and a coated layer having an outer surface smooth can be obtained.

Examples of the method of applying the composition for forming a smoothing layer 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, Laws and the like. Of these, the gravure coating method and the bar coating method are more preferable, and the bar coating method is more preferable. Thus, a coated layer having a desired thickness can be easily formed.

<Smoothing Layer Forming Step>

Next, the smoothing layer 12 is formed by heating and curing the coating layer obtained by the coating layer forming step.

In this step, in the coating layer forming step, the coated layer in which the concavities and convexities of the first surface 111 of the substrate 11 are accurately buried is cured while maintaining the smoothness of the outer surface. As a result, the smoothing layer 12 whose third surface 121 is sufficiently smooth can be obtained. This can further prevent the influence of the concavities and convexities of the first surface 111 of the substrate 11 on the outer surface 131 of the release agent layer 13 more preferably. Therefore, in the step of forming a release agent layer described later, the smoothness of the outer surface 131 of the release agent layer 13 can be made excellent.

The heating method is not particularly limited, and examples include a method of heating in a hot air drying furnace and the like.

The heating conditions are not particularly limited. The heating temperature is preferably 80 to 150 ° C, and the heating time is preferably 5 seconds to 1 minute. As a result, undesirable alteration of the smoothing layer 12 can be prevented, and the smoothing layer 12 can be formed with high efficiency. As a result, the productivity of the finally obtained release film (1) can be improved. If the heating temperature is in the above range, the smoothing layer 12, which is accompanied by evaporation of a solvent or the like during heating, can be prevented from being bent or cracked when the composition for smoothing layer contains a solvent or the like .

<Step of forming release agent layer>

Next, a release agent layer 13 is formed on the side of the smoothing layer 12 opposite to the substrate 11 side.

As a composition for forming a release agent layer constituting the release agent layer 13, a composition prepared by mixing the above-described materials is prepared.

Subsequently, a composition for forming a release agent layer is applied on the smoothing layer 12 on the surface 121 opposite to the base material 11, and then the dried composition is dried and cured to obtain a release agent layer 13.

The drying method is not particularly limited, and for example, a drying method using a hot-air drying furnace and the like can be mentioned.

The drying conditions are not particularly limited. The drying temperature is preferably 80 to 150 DEG C, and the drying time is preferably 5 seconds to 1 minute. As a result, undesirable deterioration of the release agent layer 13 can be prevented, and the release agent layer 13 can be formed with high efficiency. As a result, the productivity of the finally obtained release film (1) can be improved.

According to the process as described above, it is possible to easily and reliably produce the highly reliable peeling film 1 having excellent smoothness and excellent peeling property.

Further, when a green sheet is produced using such a release film 1, pinholes or the like can be prevented from being generated on the surface of the green sheet.

As a method for producing a ceramic green sheet using the release film 1, for example, a ceramic green dispersion slurry is applied and dried on the surface of a release agent layer of a release film to form a green sheet, A green sheet is laminated to obtain a laminate, and the laminate is fired to form an electrode on the obtained ceramic sheet. Thus, a ceramic capacitor can be obtained. As described above, when the ceramic capacitor is formed by the green sheet formed by using the release film 1, it is possible to obtain a highly reliable ceramic capacitor in which a problem caused by a short circuit is prevented.

While the present invention has been described in detail based on the preferred embodiments, the present invention is not limited thereto

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

Further, for example, in the above-described embodiments, the release film for green sheet production has been described as having a three-layer structure in which the base material, the smoothing layer, and the stripping agent layer are laminated in this order so as to be bonded to each other. However, An intermediate layer may be formed between the layer and the release agent layer. Further, an intermediate layer may be formed between the substrate and the smoothing layer. Such an intermediate layer may be a layer for improving the adhesion between the smoothing layer and the peeling agent layer and may be a layer for further suppressing the occurrence of charging when the peeling film for green sheet production before green sheet formation is wound.

The method for producing a release film for green sheet of the present invention is not limited to the above-described method, and an optional step may be added as necessary.

Example

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

[1] Production of release film for green sheet production

(Example 1)

First, the biaxially oriented polyethylene terephthalate film [thickness as a substrate: 38㎛, the arithmetic mean roughness Ra of the first side ₂ up to the projection height of 42nm, the first surface Rp _2: 619nm, the arithmetic mean roughness Ra of the second surface ₃ : 42 nm, and the maximum protrusion height Rp _{3 on} the second surface: 619 nm).

Next, 100 parts by mass of a bisphenol A type epoxy ester compound [TA31-059D (product of Hitachi Kasei Polymer Co., Ltd., solids concentration: 50% by mass, mass average molecular weight: 530)] as a thermosetting compound and 3 parts by mass of acid catalyst p-toluenesulfonic acid , Toluene, and methyl ethyl ketone were mixed to obtain a composition for forming a smoothing layer having a solid content of 20 mass%.

The thus obtained smoothed layer forming composition was applied to the first surface of the substrate with Meyer Bar # 4 to obtain a coated layer.

Next, the coated layer was heated at 130 DEG C for 1 minute to form a smoothing layer (thickness: 1.3 mu m).

Further, 100 parts by mass of a mixture of an addition reaction type silicone compound and a crosslinking agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "silicone KS-847H", solid content 30% by mass) as a releasing agent was diluted with toluene to obtain a diluted solution. 2 parts by mass of a platinum catalyst [manufactured by Shin-Etsu Chemical Co., Ltd., trade name &quot; PL-50T &quot;] 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. The composition for forming a release agent layer was uniformly coated on the surface opposite to the substrate of the smoothing layer so that the thickness after drying of the composition for forming a release agent layer was 0.1 mu m. Thereafter, the composition for releasing the release agent layer was dried at 130 DEG C for 1 minute to form a release agent layer, and a release film for the production of a green sheet was produced.

(Example 2)

Example 1, a biaxially stretched polyethylene terephthalate film, a biaxially stretched polyethylene terephthalate film [thickness: 31㎛, the average roughness Ra ₂ of the first surface arithmetic: maximum protrusion height of 29nm, the first surface Rp _2: 257nm, The arithmetic average roughness Ra _{3 of} the second surface: ₂₉ nm, and the maximum protrusion height Rp ₃ of the second surface: 257 nm).

(Example 3)

The biaxially stretched polyethylene terephthalate film of Example 1 was stretched by a biaxially stretched polyethylene terephthalate film (having a thickness of 31 탆, an arithmetic mean roughness Ra _{2 of} 15 nm, a maximum protrusion height Rp ₂ of the first surface of 98 nm, the second surface arithmetic mean roughness Ra _3: 15nm, the maximum protrusion height of the second surface Rp _3: non-change to 98nm], and changes the thickness of the smoothing layer is to 0.4㎛ of example 1, similarly to the green sheet for making a release film .

(Example 4)

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

(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 of Example 1 was changed to 2.3 탆.

(Comparative Example 1)

First, the biaxially oriented polyethylene terephthalate film [thickness as a substrate: 38㎛, the arithmetic mean roughness Ra of the first side ₂ up to the projection height of 42nm, the first surface Rp _2: 619nm, the arithmetic mean roughness Ra of the second surface ₃ : 42 nm, and the maximum protrusion height Rp _{3 on} the second surface: 619 nm).

Next, 100 parts by mass of a mixture of an addition reaction type silicone compound as a releasing agent and a crosslinking agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: "silicone KS-847H", solid content 30% by mass)] was diluted with toluene to obtain a diluted solution. 2 parts by mass of a platinum catalyst [manufactured by Shin-Etsu Chemical Co., Ltd., trade name &quot; PL-50T &quot;] 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. The composition for forming a release agent layer was uniformly coated on the first surface of the substrate so that the thickness after drying of the composition for forming a release agent layer was 0.1 mu m. Thereafter, the composition for releasing the release agent layer was dried at 130 DEG C for 1 minute to form a release agent layer, and a release film for the production of a green sheet was produced.

(Comparative Example 2)

First, the biaxially oriented polyethylene terephthalate film [thickness as a substrate: 38㎛, the arithmetic mean roughness Ra of the first side ₂ up to the projection height of 42nm, the first surface Rp _2: 619nm, the arithmetic mean roughness Ra of the second surface ₃ : 42 nm, and the maximum protrusion height Rp _{3 on} the second surface: 619 nm).

Next, 100 parts by mass of a mixture of a stearyl-modified alkyd compound and a methylated melamine compound (manufactured by Hitachi Kasei Polymer Co., Ltd., trade name &quot; TESPINE 303 &quot;, solid content 20% by mass, mass average molecular weight 15,000) as a thermosetting compound, and acid catalyst p -Toluenesulfonic acid were mixed to obtain a composition for forming a smoothing layer.

The thus obtained smoothed layer forming composition was applied to the first surface of the substrate with Meyer Bar # 4 to obtain a coated layer.

Next, the coated layer was heated at 130 占 폚 for 1 minute to form a smoothing layer (thickness 1.0 占 퐉).

Further, 100 parts by mass of a mixture of an addition reaction type silicone compound and a crosslinking agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: silicone KS-847H, solid content 30% by mass) as a releasing agent was diluted with toluene to obtain a diluted solution. 2 parts by mass of a platinum catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., trade name &quot; PL-50 T &quot;) 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. The composition for forming a release agent layer was uniformly coated on the surface opposite to the substrate of the smoothing layer so that the thickness after drying of the composition for forming a release agent layer was 0.1 mu m. Thereafter, the composition for releasing the release agent layer was dried at 130 DEG C for 1 minute to form a release agent layer, and a release film for the production of a green sheet was produced.

(Comparative Example 3)

First, the biaxially oriented polyethylene terephthalate film [thickness as a substrate: 38㎛, the arithmetic mean roughness Ra of the first side ₂ up to the projection height of 42nm, the first surface Rp _2: 619nm, the arithmetic mean roughness Ra of the second surface ₃ : 42 nm, and the maximum protrusion height Rp _{3 on} the second surface: 619 nm).

Subsequently, 80 parts by mass of a polyester compound (trade name: Vylon 20SS, solid content 30% by mass, mass average molecular weight: 3000, manufactured by Toyobara Co., Ltd.) as a thermosetting compound, 20 parts by mass of a methylated melamine compound as a crosslinking agent, 3 parts by mass of p-toluenesulfonic acid, toluene and methyl ethyl ketone were mixed to obtain a composition for forming a smoothing layer having a solid content of 20 mass%.

The thus obtained smoothed layer forming composition was applied to the first surface of the substrate with Meyer Bar # 4 to obtain a coated layer.

Next, the coated layer was heated at 130 占 폚 for 1 minute to form a smoothing layer (thickness: 1.2 占 퐉).

In addition, 100 parts by mass of a mixture of an addition reaction type silicone compound and a crosslinking agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "silicone KS-847H", solid content 30% by mass) as a releasing agent was diluted with toluene to obtain a diluted solution. 2 parts by mass of a platinum catalyst [manufactured by Shin-Etsu Chemical Co., Ltd., trade name &quot; PL-50T &quot;] 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. The composition for forming a release agent layer was uniformly coated on the surface opposite to the substrate of the smoothing layer so that the thickness after drying of the composition for forming a release agent layer was 0.1 mu m. Thereafter, the composition for releasing the release agent layer was dried at 130 DEG C for 1 minute to form a release agent layer, and a release film for the production of a green sheet was produced.

Table 1 shows the compositions of the release films for the production of green sheets in each of the Examples and Comparative Examples.

In addition, in the table, "A1" as a thermosetting compound, "A1" as a bisphenol A type epoxy ester compound [TA31-059D "by Hitachi Kasei Polymer Co., Ltd., solid content concentration of 50 mass%], a stearyl-modified alkyd compound as a thermosetting compound and a methylated melamine compound A2 "as a thermosetting compound," Vylon 20SS "as a thermosetting compound (trade name:" Vylon 20SS ", trade name, manufactured by Hitachi Kasei Polymer Kabushiki Kaisha, trade name" TESPIN 303 ", solid content 20% 30% by mass] is represented by &quot; A3 &quot;.

The thicknesses of the base material, the smoothing layer and the releasing agent layer in each of the examples and comparative examples were measured by a reflective thickness gauge "F20" (manufactured by Philatel Industries, Ltd.).

Also, arithmetic mean roughness Ra of ₂ and a maximum height of projection of the first side of the substrate Rp _2, the arithmetic mean roughness Ra of the second surface of the substrate ₃ And the maximum protrusion height Rp _3, the arithmetic mean roughness Ra ₄ and the maximum protrusion height of the third surface of the smoothing layer Rp _4, the arithmetic mean roughness Ra ₁ and the maximum protrusion height of the external surface of the release agent layer Rp _1, respectively, measured as follows: . First, a double-sided tape was attached to the glass plate. Next, the release film for green sheet production obtained in each of the Examples and Comparative Examples was fixed on the double-faced tape so that the opposite side of the side on which the arithmetic mean roughness and the maximum projection were measured was the glass plate side. In this way, the arithmetic average roughness _{Ra 2, Ra 3, Ra 4} , Ra 1, wherein the maximum projection height _{Rp 2, Rp 3, Rp 4} , Rp ₁ a, in accordance with JIS B0601-1994 honey Toyo Co., Ltd. The surface roughness meter SV3000S4 (Sensory type).

[2] Evaluation

With respect to the release film for green sheet production as described above, the following evaluations were carried out.

[2.1] Evaluation of blocking property

The release film for production of green sheets obtained in each of the Examples and Comparative Examples was rolled up in a roll shape having a width of 400 mm and a length of 5000 m to obtain a release film roll. The peeled 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 based on the following criteria.

A: There was no change in appearance of the peeled film roll after storage (no blocking), compared with the appearance of the peeled film roll before storage obtained by winding up the peeled film for green sheet production in roll form.

B: In the peel film roll for manufacturing a green sheet, there was a region having a partially different hue (although there is a tendency of blocking, usable).

C: Peel film for the production of green sheets The color tone was varied over a wide range of rolls (with blocking).

As in the case of the reference C, when the blocking due to close contact of the front and back of the release film for green sheet production occurs and the color tone changes over a wide area of the release film roll, the release film for green sheet production can not be normally released .

[2.2] Evaluation of the number of recesses

The coating liquid obtained by dissolving the polyvinyl butyral resin in a toluene / ethanol mixed solvent (mass ratio 6/4) was applied onto the release agent layer (outer surface) of the release film for green sheet production obtained in each example and each comparative example, Was 3 m, to obtain a coated layer. The coated layer was dried at 80 DEG C for 1 minute to form a polyvinyl butyral resin layer. Then, a polyester tape was attached to the surface of the polyvinyl butyral resin layer. Then, the release film for manufacturing a green sheet 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 in contact with the release agent layer of the release film for green sheet production was observed with a light interference type surface shape observation apparatus "WYKO-1100" (manufactured by Veeco Co., Ltd.). Observation conditions were PSI mode, 50 magnification. The concavities confirmed on the surface of the polyvinyl butyral resin layer were counted within the range of 91.2 x 119.8 mu m on the surface of the polyvinyl butyral resin layer. The concave portion had a depth of 150 nm or more at which the shape of the release agent layer was transferred. The number of concave portions was evaluated based on the following criteria. In addition, when a capacitor was produced using a polyvinyl butyral resin layer (green sheet) evaluated to be the following standard C, there was a tendency that a short circuit due to a decrease in withstanding voltage tended to occur.

A: The number of recesses is zero.

B: The number of recesses is 1 to 5.

C: The number of concave portions is 6 or more.

These results are shown in Table 2.

As is clear from Table 2, the release film for producing green sheets of the present invention had excellent smoothness on the outer surface. In the green sheet formed by using the release film for manufacturing a green sheet of the present invention, rough and large recesses and the like were scarcely confirmed. Further, problems such as short-circuiting were not observed in the ceramic capacitor produced by the green sheet formed by using the release film for manufacturing green sheets of the present invention. On the other hand, in the comparative example, satisfactory results were not obtained.

A release film for manufacturing a green sheet of the present invention comprises: a substrate having a first side and a second side; A smoothing layer formed on the first surface; And a release agent layer formed on the side of the smoothing layer opposite to the substrate, wherein the smoothing layer is formed by heating and curing a composition for smoothing layer formation including a thermosetting compound having a mass average molecular weight of 950 or less, and the arithmetic average roughness Ra of the outer surface of the layer ₁ than 8nm, and also characterized in that the maximum is not more than 50nm projection height Rp _1. INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a release film for use in the production of a green sheet, which can prevent the occurrence of pinholes and the like on the surface of a green sheet, and which can produce a green sheet with high reliability. Therefore, the present invention has industrial applicability.

1: Release film for green sheet production
11: substrate
111: first side of substrate
112: second side of substrate
12: Smoothing layer
121: The face (the third face)
13: Release material layer
131: outer surface of the release agent layer

Claims (7)

A release film for manufacturing a green sheet,
A substrate having a first side and a second side;
A smoothing layer formed on the first surface side of the substrate; And
And a release agent layer formed on the side of the smoothing layer opposite to the substrate,
Wherein the smoothing layer is formed by heating and curing a composition for forming a smoothing layer containing a thermosetting compound having a mass average molecular weight of 950 or less,
And the arithmetic average roughness Ra ₁ of the outer surface of the release agent layer 8nm or less, as well as the green sheet for manufacture of release film is the maximum protrusion height Rp ₁ of the outer surface of the release agent layer, characterized in that not more than 50nm. The method according to claim 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. 3. The method according to claim 1 or 2,
Wherein the smoothing layer has an average thickness of 0.2 to 10 占 퐉. 4. The method according to any one of claims 1 to 3,
Wherein the thermosetting compound is a bisphenol-type epoxy compound. 5. The method according to any one of claims 1 to 4,
Wherein the smoothing layer has an opposite surface to the substrate,
Wherein the smoothing layer and the substrate and the arithmetic mean roughness Ra of the surface ₄ of the opposite of 8nm or less, as well as the base material and the maximum protrusion height of the surface, opposite to Rp ₄ is green sheet for making a release film not more than 50nm of the smoothing layer. 6. The method according to any one of claims 1 to 5,
Wherein the arithmetic average 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. A process for producing a release film for the production of a green sheet according to any one of claims 1 to 6,
A substrate preparation step of preparing the substrate having the first surface and the second surface;
A coating layer forming step of forming the coating layer by applying the composition for forming a smoothing layer containing the thermosetting compound having a mass average molecular weight of 950 or less on the first surface side of the substrate;
A smoothing layer forming step of forming the smoothing layer by heating and hardening the coating layer; And
And a releasing agent layer forming step of forming the releasing agent layer on the surface side of the smoothing layer opposite to the substrate,
Wherein the outside the arithmetic average roughness Ra ₁ of the surface of the release agent layer is not more than 8nm, as well as green method of producing a sheet for making a release film has the maximum protrusion height Rp ₁ of the outer surface of the release agent layer, characterized in that not more than 50nm.

Images