WO2015129779A1

WO2015129779A1 - Release film for green sheet manufacturing, release film manufacturing method for green sheet manufacturing, green sheet manufacturing method, and green sheet

Info

Publication number: WO2015129779A1
Application number: PCT/JP2015/055510
Authority: WO
Inventors: 知巳深谷
Original assignee: リンテック株式会社
Priority date: 2014-02-28
Filing date: 2015-02-26
Publication date: 2015-09-03
Also published as: CN106029315B; KR102128339B1; PH12016501696B1; JP2015164762A; PH12016501696A1; JP6208047B2; KR20160127036A; CN106029315A; MY170899A

Abstract

This release film for green sheet manufacturing is characterized by the following: including a base material (11), a smoothing layer (12), and a release agent layer (13); the smoothing layer (12) is formed by heating and curing a smoothing layer formation composition that includes as the main component a melamine resin with a mass average molar weight of 950 or less; the release agent layer (13) includes a melamine resin as the main component, and is formed by heating and curing a release agent layer formation composition that includes polyorganosiloxane; the arithmetic mean roughness (Ra₁) of an outer surface (131) being 8nm or less and the maximum projection height (Rp₁) of the outer surface (131) being 50nm or less.

Description

Peeling film for producing green sheet, method for producing peeling film for producing green sheet, method for producing green sheet, and green sheet

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

In the production of ceramic capacitors, a release film for producing a green sheet (hereinafter referred to as “release film”) is used to form a green sheet.

This release film is generally composed of a base material and a release agent layer. The green sheet is formed on such a release film. In the production of the green sheet, first, a ceramic slurry in which ceramic particles and a binder resin are dispersed and dissolved in an organic solvent is applied to obtain a coated product. The green sheet is manufactured by drying the coated material. Moreover, the manufactured green sheet peels from a peeling film, and is used for manufacture of a ceramic capacitor.

In the production of a green sheet using a release film, the surface shape of the green sheet is a shape to which the surface shape of the release film is transferred. Since the surface of the conventional release film was not sufficiently smooth, there were problems such as pinholes formed on the surface of the green sheet produced using the film.

Therefore, attempts have been made to reduce the influence of the unevenness on the green sheet by suppressing the unevenness on the surface of the release film as much as possible. Examples of such a release film (release sheet) include a release sheet in which a thermosetting resin layer is provided on one surface of a base sheet, and a release layer is provided on the surface of the thermosetting resin layer (for example, Patent Document 1).

However, with the recent miniaturization and high density of ceramic capacitors, there is a demand for further thinning of the green sheets. For this reason, when it tried to manufacture a thin green sheet using the conventional peeling film, there existed a problem that the pinhole, the dispersion | variation in partial thickness, etc. occurred easily on the surface of a green sheet.

JP 2007-069360 A

An object of the present invention is to suppress or prevent the occurrence of pinholes and partial thickness variations on the surface of a green sheet. In addition, an object of the present invention is to provide a release film for producing a green sheet that can suppress or prevent the green sheet from being damaged when the green sheet is peeled from the release film. In addition, an object of the present invention is to provide a method for producing a release film for producing a green sheet capable of easily and reliably producing such a release film for producing a green sheet, and to easily and reliably produce a reliable green sheet. An object of the present invention is to provide a green sheet manufacturing method that can be manufactured and to provide a highly reliable green sheet.

Such an object is achieved by the present inventions (1) to (9) below.
(1) A release film used in the manufacture of green sheets,
A substrate having a first surface and a second surface;
A smoothing layer provided on the first surface side of the substrate;
A release agent layer provided on the surface side of the smoothing layer opposite to the base material,
The smoothing layer is formed by heating and curing a composition for forming a smoothing layer containing a melamine resin having a mass average molecular weight of 950 or less as a main component,
The release agent layer is formed by heating and curing a release agent layer forming composition containing a melamine resin as a main component and containing polyorganosiloxane,
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 smoothing layer forming composition contains a solid content, and the content of the melamine resin having a mass average molecular weight of 950 or less in the solid content of the smoothing layer forming composition is more than 50% by mass. The release film for producing a green sheet according to the above (1).

(3) The composition for forming a release agent layer includes a solid content, and the content of the melamine resin in the solid content of the composition for forming a release agent layer is 60% by mass or more (1) or A release film for producing a green sheet according to (2).

(4) The release film for producing a green sheet according to any one of (1) to (3), wherein the composition for forming a smoothing layer further contains a glycol compound.

(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 0.3 to 2 μm.

(6) The release film for producing a green sheet according to any one of (1) to (5), wherein an average film thickness of the release agent layer is 0.3 to 2 μm.

(7) A method for producing a release film for producing a green sheet according to any one of (1) to (6) above,
A base material preparation step of preparing the base material having a first surface and a second surface;
The smoothing layer forming composition is applied to the first surface side of the base material to form the first coating layer, and then the first coating layer is heated and cured to cure the smoothness. A smoothing layer forming step of forming a condensing layer;
The second coating layer is formed by applying the release agent layer forming composition on the surface of the smoothing layer opposite to the base material, and then heating and curing the second coating layer. A release agent layer forming step of forming the release agent layer,
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. Method for producing a release film.

(8) A green sheet forming material containing ceramic powder and a vehicle containing a binder is provided on the release film for producing a green sheet according to any one of (1) to (6) above, to thereby produce a green sheet precursor A green sheet forming material application step for forming a body;
And a solidifying step for solidifying the green sheet precursor.

(9) A green sheet produced by the method for producing a green sheet described in (8) above.

According to the present invention, the release film for producing a green sheet is excellent in surface smoothness. Therefore, according to the release film for producing a green sheet of the present invention, it is possible to suppress or prevent the occurrence of pinholes, partial thickness variations and the like on the surface of the green sheet. Moreover, according to this invention, it is excellent in the peelability with respect to the green sheet formed on the peeling film for green sheet manufacture. Therefore, it is possible to suppress or prevent the green sheet from being damaged when the green sheet is peeled off. Therefore, according to this invention, the peeling film for green sheet manufacture which can manufacture a highly reliable green sheet can be provided.

Also, according to the present invention, a release film for producing a green sheet that can produce a highly reliable green sheet can be produced easily and reliably. Moreover, according to this invention, the manufacturing method of the green sheet which can manufacture a reliable green sheet easily and reliably can be provided. Moreover, according to this invention, a reliable green sheet can be provided.

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

Hereinafter, the release film for producing a green sheet, the method for producing a release film for producing a green sheet, the method for producing a green sheet, and the green sheet of the present invention will be described in detail based on preferred embodiments.

≪Peeling film for green sheet manufacturing≫
First, the release film for producing the green sheet of the present invention will be described.

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.

The release film for producing a green sheet of the present invention includes a substrate, a smoothing layer, and a release agent layer. The smoothing layer is formed by heating and hardening a composition for forming a smoothing layer containing a melamine resin having a mass average molecular weight of 950 or less as a main component. The release agent layer is formed by heating and curing a release agent layer forming composition containing a melamine resin as a main component and containing polyorganosiloxane. In the release film for producing a green sheet of the present invention, 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. It has the feature in that.

By having such characteristics, the release film for producing a green sheet is excellent in the smoothness of the outer surface of the release agent layer. Therefore, if a green sheet is manufactured using this release film for manufacturing a green sheet, it is possible to suppress or prevent the occurrence of pinholes, partial thickness variations, and the like on the surface of the green sheet. Moreover, by having such a feature, the release film for producing a green sheet is excellent in releasability from the green sheet formed on the release film for producing a green sheet. Therefore, it can suppress or prevent that a green sheet breaks when peeling a green sheet from a peeling film. Therefore, if the release film for producing a green sheet of the present invention is used, a highly reliable green sheet can be provided. And when the obtained green sheet is laminated | stacked and a capacitor | condenser is produced, it can prevent that the malfunction by a short circuit or a disconnection generate | occur | produces.

Hereinafter, the release film 1 for producing the green sheet of the present embodiment will be described.
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, a release film for green sheet production (hereinafter simply referred to as “release film”) 1 includes a substrate 11 having a first surface 111 and a second surface 112, and The smoothing layer 12 provided on the first surface 111 and the release agent layer 13 provided on the third surface (surface opposite to the base material 11) 121 of the smoothing layer 12 are provided. . That is, the release film 1 has a three-layer structure in which the base material 11, the smoothing layer 12, and the release agent layer 13 are laminated so as to be joined to each other in this order.

In addition, when manufacturing a green sheet using the release film 1, the green sheet is formed by applying a dissolved ceramic slurry on the outer surface 131 of the release agent layer 13, for example. A method for producing a green sheet using such a release film 1 will be described in detail later.

Below, each layer which comprises the peeling film 1 is demonstrated one by one.
<Substrate 11>
The substrate 11 has a function of imparting physical strength such as rigidity and flexibility to the release film 1.

As shown in FIG. 1, the base material 11 has a first surface 111 and a second surface 112.
The substrate 11 is not particularly limited, and includes, for example, polyester resins such as polybutylene terephthalate resin, polyethylene terephthalate resin and polyethylene naphthalate resin, polyolefin resins such as polypropylene resin and polymethylpentene resin, and plastics such as polycarbonate. The film etc. which were formed with material are mentioned. 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, the substrate 11 is preferably a polyester film, more preferably a polyethylene terephthalate film, and even more preferably a biaxially stretched polyethylene terephthalate film. Polyester films are less prone to dust and the like during processing and use. Therefore, if a green sheet is produced using the release film 1 having a polyester film as the base material 11, 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 can be obtained.

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, and aluminum oxide. As the substrate 11, one or more of these can be used in combination. By including such a filler, mechanical strength can be imparted to the substrate 11, and the slipperiness of the front and back surfaces (the first surface 111 and the second surface 112) of the substrate 11 can be improved. Can do. For this reason, it can suppress especially that the front and back of the peeling film 1 adheres (blocking) when the peeling film 1 is stored in the wound state.

The base material 11 preferably has an arithmetic average roughness Ra ₂ of the first surface 111 of 1 to 100 nm and a maximum protrusion height Rp ₂ of the first surface 111 of 10 to 800 nm.

In particular, the arithmetic average roughness Ra ₂ of the first surface 111 is more preferably 5 to 80 nm, and further preferably 10 to 50 nm. Further, the maximum protrusion height Rp ₂ of the first surface 111 is more preferably 20 to 500 nm, and further preferably 30 to 300 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, the smoothing layer 12 even when the smoothing layer 12 described later is relatively thin. Thus, the unevenness of the first surface 111 of the substrate 11 can be embedded more suitably. Thereby, the 3rd surface 121 of the smoothing layer 12 can also be smoothed. As a result, the unevenness of the first surface 111 of the substrate 11 can be suitably prevented from affecting the outer surface 131 of the release agent layer 13 formed on the smoothing layer 12. Moreover, the base material 11 having the arithmetic mean roughness Ra ₂ and the maximum protrusion height Rp _{2 of} the first surface 111 within the above ranges is relatively inexpensive and easily available.

The arithmetic average roughness Ra ₂ and the maximum protrusion height Rp ₂ of the first surface 111 are, for example, using an optical interference type surface shape observation device (trade name “WYKO-1100”, manufactured by Veeco Co., Ltd.) It can be determined by measuring in PSI mode, 50 magnification, measurement range: 91.2 × 119.8 μm. In the present specification, unless otherwise specified, “arithmetic average roughness and maximum protrusion height” refer to values measured as described above.

The base material 11 has an arithmetic average roughness Ra _{3 of} the second surface (back surface of the release film 1) 112 of 1 to 100 nm and a maximum protrusion height Rp _{3 of} the second surface 112 of 10 to 100 nm. 800 nm is preferred.

In particular, the arithmetic average roughness Ra ₃ of the second surface 112 is more preferably 5 to 80 nm, and further preferably 10 to 50 nm. Further, the maximum protrusion height Rp ₃ of the second surface 112 is more preferably 20 to 500 nm, and further preferably 30 to 300 nm.

When the arithmetic average roughness Ra ₃ and the maximum protrusion height Rp _{3 of} the second surface 112 are within the above ranges, it is preferable to prevent winding deviation or the like from occurring when the release film 1 is wound into a roll shape. Can do. Specifically, the release film 1 can be wound and stored in a roll shape around a core material such as paper, plastic, or metal as necessary. At this time, when the arithmetic average roughness Ra ₃ and the maximum protrusion height Rp _{3 of} the second surface 112 are within the above ranges, the air release becomes favorable when the release film 1 is wound into a roll shape, 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.

Further, when the arithmetic average roughness Ra ₃ and the maximum protrusion height Rp _{3 of} the second surface 112 are within the above ranges, when the release film 1 is wound up and stored in a roll shape, the release agent layer 13 and the base surface It is possible to more effectively prevent the occurrence of blocking that occurs when the second surface 112 of the material 11 contacts with no gap. Therefore, the roll-shaped release film 1 can be easily fed out.

The average film thickness of the substrate 11 is not particularly limited, but is preferably 10 to 300 μm, and more preferably 15 to 200 μm. Thereby, the peeling film 1 has moderate softness | flexibility, and is especially excellent in the tolerance with respect to tearing, a fracture | rupture, etc.

<Smoothing layer 12>
As shown in FIG. 1, the smoothing layer 12 is provided on the first surface 111 of the substrate 11.

The smoothing layer 12 has a function of reducing the unevenness of the first surface 111 of the substrate 11 from affecting the outer surface 131 of the release agent layer 13.

The smoothing layer 12 is formed by applying a smoothing layer forming composition on the first surface 111 of the substrate and applying a first coating layer (the smoothing layer forming composition on the first surface 111 of the substrate). After forming the layer obtained by coating, the first coating layer can be obtained by heating and curing. Such a composition for forming a smoothing layer contains a melamine resin having a mass average molecular weight of 950 or less as a main component. Here, the said main component means the component in which the content rate in solid content of the composition for smoothing layer formation exceeds 50 mass%.

Such a composition for forming a smoothing layer has an appropriate viscosity and fluidity before being applied to the first surface 111 of the substrate 11 and heated. Therefore, if the smoothing layer 12 is formed on the 1st surface 111 of the base material 11 using such a composition for smoothing layer formation, the unevenness | corrugation of the 1st surface 111 of the base material 11 will be more suitable. Can be embedded. As a result, the third surface 121 of the smoothing layer 12 (the surface opposite to the substrate 11 of the smoothing layer 12) 121 can be made smoother. Thereby, the outer surface 131 (the outer surface of the release film 1) 131 of the release agent layer 13 formed on the smoothing layer 12 can be smoothed.

Thus, if the composition for forming a smoothing layer containing the melamine resin is used, it is possible to suppress or prevent the unevenness of the base material 11 from affecting the outer surface 131 of the release film 1.

In particular, even when the unevenness of the first surface 111 of the substrate 11 is relatively large, the unevenness of the first surface 111 of the substrate 11 can be obtained by using the smoothing layer forming composition as described above. Can be suitably embedded. For this reason, even if it is a case where the unevenness | corrugation of the 1st surface 111 of the base material 11 is comparatively large, the peeling film 1 excellent in the smoothness of the outer surface 131 of the releasing agent layer 13 can be obtained. .

Further, if a smoothing layer forming composition containing a melamine resin having a mass average molecular weight within the above range is used, the resulting smoothing layer 12 is particularly excellent in chemical resistance.

Further, as described above, the composition for forming a smoothing layer may contain a melamine resin having a mass average molecular weight of 950 or less as a main component. In particular, a melamine resin having a mass average molecular weight of 300 to 700 is mainly used. It is preferable to include it as a component, and more preferable to include a melamine resin having a mass average molecular weight of 350 to 500 as a main component. Thereby, the effect mentioned above can be exhibited notably.

On the other hand, when the mass average molecular weight of the melamine resin exceeds the upper limit, the fluidity of the composition for forming a smoothing layer is lowered. Therefore, the unevenness of the first surface 111 of the base material 11 may not be sufficiently embedded by the smoothing layer 12. As a result, the third surface 121 of the smoothing layer 12 may have a shape that follows the unevenness of the first surface of the substrate 11. Therefore, there is a possibility that the unevenness of the first surface 111 of the substrate 11 cannot be suppressed from affecting the outer surface 131 of the release agent layer 13.

Examples of the melamine resin having a mass average molecular weight within the above range include a monomethoxymethylated melamine resin, a dimethoxymethylated melamine resin, a trimethoxymethylated melamine resin, a tetramethoxymethylated melamine resin, a pentamethoxymethylated melamine resin, and a hexamethoxymethylated resin. Methoxymethylated melamine resin, butylated melamine resin, monomethylol melamine resin, dimethylol melamine resin, trimethylol melamine resin, tetramethylol melamine resin, pentamethylol melamine resin, hexamethylol melamine resin, imino group-containing methoxymethylated melamine resin, etc. Is mentioned. Among these, as the melamine resin, hexamethoxymethylated melamine resin is preferable from the viewpoint of excellent reactivity. Thereby, even if the smoothing layer 12 having a relatively thin film thickness is formed, the unevenness of the first surface 111 of the substrate 11 can be filled more easily and reliably. Moreover, such a smoothing layer 12 is excellent in chemical resistance. Thereby, when apply | coating the release agent layer forming composition containing a solvent on the smoothing layer 12, and providing the release agent layer 13, the smoothing layer resulting from the solvent contained in the release agent layer forming composition It is possible to avoid swelling of 12 and dissolution and dropping off.

Further, the content of the melamine resin in the smoothing layer forming composition (in terms of solid content) may be more than 50% by mass as described above, but more preferably 60% by mass or more. More preferably, it is 65 mass% or more. Thereby, before apply | coating to the 1st surface 111 of the base material 11 and heating, the composition for smoothing layer formation has moderate viscosity.

Such a composition for forming a smoothing layer containing the melamine resin preferably further contains a diluent having a hydroxyl group (reactive diluent), and preferably contains a diluent having a hydroxyl group at both molecular ends. More preferably, a glycol-based compound is further included.

Such a diluent reduces the viscosity of the smoothing layer forming composition. Moreover, when the composition for smoothing layer formation containing such a diluent is heated, a diluent will couple | bond (crosslink) with the said melamine resin. Therefore, the smoothing layer forming composition containing the diluent having a hydroxyl group can obtain more suitable fluidity. For this reason, if the composition for smoothing layer formation containing such a diluent is used, the unevenness | corrugation of the 1st surface 111 of the base material 11 can be embedded more suitably.

In particular, the glycol compound is a compound having a hydroxyl group at both molecular ends, a relatively small molecular weight, and a lower viscosity than the melamine resin. Therefore, when the composition for smoothing layer formation contains a glycol compound, the viscosity of the composition for smoothing layer formation containing the said melamine resin falls more. Therefore, the smoothing layer forming composition having more appropriate fluidity can be obtained.

Specific examples of the glycol compound include ethanediol, 1,3-propanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, and the like. Among these, 2-methyl-1,3-propanediol is preferable as the glycol compound. Thereby, the composition for smoothing layer formation can obtain optimal viscosity, and is effectively embedded by the unevenness | corrugation of the 1st surface 111 of the base material 11. FIG.

When such a diluent having a hydroxyl group is contained, the content of the diluent having a hydroxyl group in the composition for forming a smoothing layer (in terms of solid content) is preferably 10 to 45% by mass, and preferably 15 to 40% by mass. % Is more preferable.

If the content of the diluent having a hydroxyl group is less than the lower limit, the viscosity of the smoothing layer-forming composition may become very high depending on the type of material contained in the smoothing layer-forming composition. There is. Moreover, even if the content rate of the diluent which has a hydroxyl group exceeds the said upper limit, the effect by containing the diluent which has a hydroxyl group cannot be heightened any more. Moreover, the content rate of materials other than the diluent which has a hydroxyl group contained in the composition for smoothing layer formation will fall.

Further, the smoothing layer forming composition preferably contains an acidic catalyst as a curing catalyst. The acidic catalyst acts as a crosslinking reaction catalyst that promotes the crosslinking reaction of the melamine resin. Therefore, when the composition for smoothing layer formation containing an acidic catalyst is heated and the crosslinking reaction of a melamine resin is started, the reaction rate of the crosslinking reaction can be accelerated. Thereby, the hardening reaction of the composition for smoothing layer formation can be advanced more efficiently.

The acid catalyst is not particularly limited and may be any catalyst as long as it functions as a crosslinking reaction catalyst as described above. Examples of the acidic catalyst include organic acidic catalysts such as p-toluenesulfonic acid and methanesulfonic acid. As the acidic catalyst, one or two or more of these can be used in combination. Among these, the acidic catalyst preferably contains p-toluenesulfonic acid. Thereby, the hardening reaction of the composition for smoothing layer formation can be advanced further efficiently.

When such an acidic catalyst is included, the content of the acidic catalyst in the smoothing layer forming composition (in terms of solid content) is preferably 0.1 to 15% by mass, and preferably 0.5 to 10% by mass. More preferred.

If the content of the acidic catalyst is less than the lower limit, depending on the type of material contained in the smoothing layer-forming composition, the rate at which the smoothing layer-forming composition is cured may be very slow. is there. Moreover, even if the content rate of an acidic catalyst exceeds the said upper limit, the effect by containing an acidic catalyst cannot be heightened any more. Moreover, the content rate of materials other than the acidic catalyst contained in the composition for smoothing layer formation will fall.

Moreover, the composition for smoothing layer formation may be comprised so that a solvent may be included as needed.
The solvent is not particularly limited. For example, ketones such as dimethyl ketone, methyl ethyl ketone, diethyl ketone, and cyclohexanenon, aromatic hydrocarbons such as benzene, toluene, and xylene, and aliphatic hydrocarbons such as hexane, heptane, and octane. , Aliphatic hydrocarbons such as hexane, heptane and octane, alcohols such as methanol, ethanol and isopropanol, and mixed solvents thereof.

Moreover, it does not specifically limit as content rate of the solvent in the composition for smoothing layer formation, In order to make the viscosity of the composition for smoothing layer formation at the time of forming the smoothing layer 12 into a suitable range suitably It only has to be selected.

In addition, the smoothing layer forming composition may contain other components other than the above-described materials (melamine resin, diluent having a hydroxyl group, acidic catalyst, and solvent) as necessary. Other components include, for example, thermosetting resins other than the melamine resin (melamine resin having a mass average molecular weight of 950 or less), diluents other than a diluent having a hydroxyl group, curing catalysts other than acidic catalysts, surface conditioners, Examples thereof include dyes, dispersants, and antistatic agents.

The third surface (the surface opposite the substrate 11 of the smoothing layer 12) 121 of the smoothing layer 12, its is the arithmetic average roughness Ra ₄ is 30nm or less, and the maximum projection height Rp ₄ Is preferably 300 nm or less. In particular, the arithmetic average roughness Ra ₄ of the third surface 121 is preferably 10 nm or less. In addition, the maximum protrusion height Rp ₄ of the third surface 121 is preferably 200 nm or less.

If the arithmetic average roughness Ra ₄ and the maximum protrusion height Rp _{4 of} the third surface 121 are within the above ranges, the unevenness of the first surface 111 of the substrate 11 affects the outer surface 131 of the release agent layer 13. This can be prevented more suitably. As a result, the unevenness of the first surface 111 of the substrate 11 can be reliably prevented from affecting the outer surface 131.

On the other hand, when the arithmetic average roughness Ra ₄ of the third surface 121 exceeds the upper limit value, the smoothing layer 12 can suppress the unevenness of the first surface 111 from affecting the outer surface 131. It is difficult. As a result, in order to reduce the unevenness of the first surface 111 from affecting the outer surface 131, it is necessary to make the thickness of the smoothing layer 12 larger than the thickness of the smoothing layer 12 within the above range. There is a case. Further, it may be necessary to further provide a new smoothing layer between the release agent layer 13 and the smoothing layer 12.

Further, when the maximum protrusion height Rp ₄ of the third surface 121 exceeds the upper limit value, it is difficult for the smoothing layer 12 to suppress the unevenness of the first surface 111 from affecting the outer surface 131. It is in a state. As a result, in order to reduce the unevenness of the first surface 111 from affecting the outer surface 131, it is necessary to make the thickness of the smoothing layer 12 larger than the thickness of the smoothing layer 12 within the above range. There is a case. Further, it may be necessary to further 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 0.3 to 2 μm, and more preferably 0.4 to 1 μm. Thereby, the unevenness | corrugation of the 1st surface 111 of the base material 11 can be embedded more correctly. As a result, the smoothness of the outer surface 131 can be further improved.

On the other hand, if the average film thickness of the smoothing layer 12 is less than the lower limit value, the smoothness of the outer surface 131 becomes insufficient depending on the film thickness of the release agent layer 13 or the like. Therefore, when the green sheet is formed on the release agent layer 13, there is a possibility that pinholes and partial thickness variations may occur in the green sheet. 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. There is a risk.

<Release layer 13>
As shown in FIG. 1, a release agent layer 13 is provided on the third surface 121 of the smoothing layer 12.
The release agent layer 13 has a function of imparting peelability to the release film 1.

The release agent layer 13 can be obtained by heating and curing the release agent layer forming composition. Such a release agent layer-forming composition contains a melamine resin as a main component and also contains a polyorganosiloxane. Here, the said main component means the component in which the content rate in solid content of the composition for release agent layer formation exceeds 50 mass%.

The release agent layer 13 formed using such a release agent layer forming composition is in a state where components derived from polyorganosiloxane are segregated in the vicinity of the outer surface 131. This is because the compatibility between the melamine resin contained in the release agent layer forming composition and the polyorganosiloxane is low. Specifically, the composition obtained by applying the release agent layer forming composition on the smoothing layer 12 and applying the second application layer (the release agent layer forming composition on the smoothing layer 12). ) And the second coating layer is heated to cure, the compatibility between the melamine resin and the polyorganosiloxane is low, so the component derived from the polyorganosiloxane is near the surface of the second coating layer. This is because segregation easily occurs.

This polyorganosiloxane is a component having excellent releasability from the green sheet. Therefore, when the component derived from polyorganosiloxane is segregated in the vicinity of the outer surface 131, the release film 1 is excellent in releasability from the green sheet. As a result, a green sheet is formed on the outer surface 131 of the release film 1, and the green sheet is prevented from adhering to the release film 1 more than necessary when the green sheet is to be released from the release film 1. Or it can be prevented. That is, it is possible to suppress or prevent the green sheet from being peeled off from the release film 1 and being damaged.

Further, the content of the melamine resin in the release agent layer forming composition (in terms of solid content) may be more than 50% by mass as described above, but more preferably 60% by mass or more. More preferably, it is 65 mass% or more. Thereby, before apply | coating and heating the release agent layer forming composition to the 3rd surface 121 of the smoothing layer 12, the viscosity of the releasing agent layer forming composition becomes more moderate.

Further, as described above, the composition for forming a release agent layer contains a melamine resin as a main component, but preferably contains a melamine resin having a mass average molecular weight of 950 or less as a main component, and has a mass average molecular weight of 300 to 700. It is more preferable to contain a melamine resin as a main component, and it is more preferable to include a melamine resin having a mass average molecular weight of 350 to 500 as a main component. Thereby, the viscosity of the release agent layer forming composition can be moderated, and the release agent layer forming composition has appropriate fluidity. Therefore, when the release agent layer 13 is formed using this release agent layer forming composition, the unevenness of the base material 11 that cannot be embedded by the smoothing layer 12 can be embedded more accurately. Moreover, the release agent layer forming composition having a mass average molecular weight within the above range is excellent in chemical resistance. Thus, even when the release agent layer forming composition containing a solvent is applied onto the smoothing layer 12 to form the release agent layer 13, the release agent layer 13 swells or dissolves and falls off. Can be avoided.

Specific examples of the melamine resin include monomethoxymethylated melamine resin, dimethoxymethylated melamine resin, trimethoxymethylated melamine resin, tetramethoxymethylated melamine resin, pentamethoxymethylated melamine resin, hexamethoxy Methylated melamine resin, butylated melamine resin, monomethylol melamine resin, dimethylol melamine resin, trimethylol melamine resin, tetramethylol melamine resin, pentamethylol melamine resin, hexamethylol melamine resin, imino group-containing methoxymethylated melamine resin, etc. Can be mentioned. As the melamine resin, one or a combination of two or more of these can be used. Among these, from the viewpoint of excellent reactivity, the melamine resin is preferably a hexamethoxymethylated melamine resin. In particular, by forming the release agent layer 13 using the release agent layer forming composition containing hexamethoxymethylated melamine resin, the unevenness of the first surface 111 of the substrate 11 that could not be filled with the smoothing layer 12. Even if there is, the unevenness can be embedded more accurately.

The melamine resin contained in the release agent layer forming composition and the melamine resin contained in the smoothing layer forming composition are both preferably the same, and in particular, are hexamethoxymethylated melamine resins. Is preferred. Thereby, the adhesiveness to the smoothing layer 12 of the releasing agent layer 13 can further be improved. For this reason, it is possible to prevent the release agent layer 13 from unintentionally peeling from the smoothing layer 12. Furthermore, the smoothing layer 12 and the release agent layer 13 formed using such a smoothing layer forming composition and a release agent layer forming composition, respectively, are excellent in chemical resistance.

The polyorganosiloxane preferably has a reactive functional group such as a carboxyl group, a methoxy group, or a hydroxyl group, and is particularly preferably a silanol-terminated polydimethylsiloxane having a hydroxyl group at the molecular end.

Thus, since the polyorganosiloxane has a reactive functional group, the polyorganosiloxane has reactivity with the melamine resin. Therefore, when the release agent layer-forming composition is heated and cured, the polyorganosiloxane can form a crosslinked structure with the melamine resin as the main skeleton. Therefore, when a green sheet is formed on the obtained release film 1, it is possible to suppress transfer of components derived from the polyorganosiloxane of the release agent layer 13 to the green sheet.

In particular, when silanol-terminated polydimethylsiloxane having a hydroxyl group at the molecular end is used as the polyorganosiloxane, the above-described effects can be exhibited particularly remarkably.

The content of the polyorganosiloxane in the release agent layer forming composition (in terms of solid content) is preferably 3 to 15% by mass, and particularly preferably 5 to 12% by mass.

When the content of the polyorganosiloxane is less than the lower limit, depending on the type of material other than the polyorganosiloxane contained in the composition for forming the release agent layer and the content thereof, the release property of the release agent layer 13 may be increased. It becomes insufficient. As a result, the green sheet may not be normally peeled from the release film 1.

On the other hand, when the content of the polyorganosiloxane exceeds the upper limit value, the second coating layer formed on the smoothing layer 12 (obtained by applying the release agent layer forming composition on the smoothing layer 12). The amount of segregation of components derived from polyorganosiloxane that segregates in the vicinity of the surface of the formed layer) increases. This may cause spots on the surface of the second coating layer. For this reason, when apply | coating a ceramic slurry on the outer surface 131 of the obtained peeling film 1, there exists a possibility that the coating property of a ceramic slurry may deteriorate and the flip of a ceramic slurry may generate | occur | produce. As a result, pinholes are generated in the green sheet, which may deteriorate the characteristics of the green sheet.

Such a composition for forming a release agent layer containing the melamine resin preferably further contains a diluent having a hydroxyl group (reactive diluent), and preferably contains a diluent having a hydroxyl group at both molecular ends. More preferably, a glycol-based compound is further included.

Such a diluent reduces the viscosity of the release agent layer forming composition. Moreover, when the composition for forming a release agent layer containing such a diluent is heated, the diluent bonds (crosslinks) with the melamine resin. Therefore, when the release agent layer forming composition contains such a diluent, the fluidity of the release agent layer forming composition can be made more suitable. Therefore, even if the smoothing layer 12 has the unevenness of the base material 11 that could not be embedded, the unevenness can be embedded more accurately.

In particular, the glycol compound is a compound having a hydroxyl group at both molecular ends, has a relatively small molecular weight, and has a lower viscosity than the melamine resin. Therefore, the viscosity of the composition for forming a release agent layer can be further reduced by including a glycol compound. Therefore, a release agent layer forming composition having more appropriate fluidity can be obtained.

Examples of glycol compounds include methanediol, ethanediol, 1,3-propanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, and the like. Of these, 2-methyl-1,3-propanediol is preferred as the glycol compound. Thereby, the viscosity of the composition for forming the release agent layer can be set optimally. As a result, even if the smoothing layer 12 has unevenness of the substrate 11 that could not be embedded, the unevenness can be embedded more accurately.

When the release agent layer forming composition contains such a diluent having a hydroxyl group, the content of the diluent having a hydroxyl group in the release agent layer forming composition (in terms of solid content) is 10 to 45 masses. % Is preferable, and 15 to 40% by mass is more preferable.

If the content of the diluent having a hydroxyl group is less than the lower limit, the viscosity of the release agent layer-forming composition may become very high depending on the type of material contained in the release agent layer-forming composition. There is. Moreover, even if the content rate of the diluent which has a hydroxyl group exceeds the said upper limit, the effect by containing the diluent which has a hydroxyl group cannot be heightened any more. Moreover, the content rate of materials other than the diluent which has a hydroxyl group contained in the composition for release agent layer formation will fall.

Further, the release agent layer forming composition preferably contains an acidic catalyst as a curing catalyst. The acidic catalyst acts as a crosslinking reaction catalyst that promotes the crosslinking reaction of the melamine resin. Therefore, when the release agent layer forming composition contains an acidic catalyst, the curing reaction of the release agent layer forming composition can be advanced more efficiently.

The acidic catalyst is not particularly limited, and any acidic catalyst may be used as long as it functions as a crosslinking reaction catalyst with the melamine resin. Specifically, examples of the acidic catalyst include organic acidic catalysts such as p-toluenesulfonic acid and methanesulfonic acid. As the acidic catalyst, one or a combination of two or more of these can be used. Among these, it is particularly preferable that the acidic catalyst contains p-toluenesulfonic acid. Thereby, the curing reaction of the composition for forming a release agent layer can be further efficiently advanced.

When such an acidic catalyst is included, the content of the acidic catalyst in the release agent layer forming composition (in terms of solid content) is preferably 0.1 to 15% by mass, and preferably 0.5 to 10% by mass. More preferred.

If the content of the acidic catalyst is less than the lower limit, depending on the type of material contained in the release agent layer-forming composition, the rate of curing of the release agent layer-forming composition may be very slow. is there. Moreover, even if the content rate of an acidic catalyst exceeds the said upper limit, the effect by containing an acidic catalyst cannot be heightened any more. Moreover, the content rate of materials other than the acidic catalyst contained in the composition for release agent layer formation will fall.

Moreover, the composition for forming a release agent layer may contain a solvent, if necessary. The solvent is not particularly limited. For example, ketones such as dimethyl ketone, methyl ethyl ketone, diethyl ketone, and cyclohexanenon, aromatic hydrocarbons such as benzene, toluene, and xylene, and aliphatic hydrocarbons such as hexane, heptane, and octane. , Aliphatic hydrocarbons such as hexane, heptane and octane, alcohols such as methanol, ethanol and isopropanol, and mixed solvents thereof.

Further, the content of the solvent in the release agent layer forming composition is not particularly limited. What is necessary is just to select suitably as content rate of a solvent so that the viscosity of the composition for release agent layer formation at the time of forming the release agent layer 13 on the smoothing layer 12 may be made into an appropriate range.

In addition, the composition for forming a release agent layer may contain other components other than the above-described materials (melamine resin, diluent having a hydroxyl group, acidic catalyst, and solvent) as necessary. Examples of the other components include thermosetting resins other than the melamine tree, diluents other than diluents having a hydroxyl group, curing catalysts other than acidic catalysts, surface conditioners, dyes, dispersants, antistatic agents, and the like. It is done.

Further, as described above, the outer surface 131 of the release agent layer 13 (the outer surface of the release film 1) has an arithmetic average roughness Ra ₁ is a 8nm or less, and a maximum projection height Rp ₁ of the outer surface 131 50 nm or less. In particular, an arithmetic average roughness Ra ₁ of the outer surface 131 is preferably at 6nm or less. In addition, the maximum protrusion height Rp _{1 of} the outer surface 131 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, the uneven shape of the outer surface 131 is transferred to the green sheet when the green sheet is formed. This can be suppressed or prevented. Therefore, it can prevent more suitably that a pinhole etc. generate | occur | produce on the surface of a green sheet. As a result, a green sheet having a higher smooth surface can be obtained.

In addition, the release agent layer 13 preferably has an average film thickness of 0.3 to 2 μm, and more preferably 0.5 to 1 μm. When the thickness of the release agent layer 13 is less than the lower limit value, the smoothness of the release agent layer 13 becomes insufficient depending on the material constituting the release agent layer 13 or the like. Therefore, when a green sheet is formed on the release film 1, there is a possibility that pinholes and partial thickness variations occur in the green sheet. On the other hand, when the thickness of the release agent layer 13 exceeds the upper limit, curling may occur easily in the release film 1 due to curing shrinkage of the release agent layer 13.

≪Method for producing release film for green sheet production≫
Next, the manufacturing method of the peeling film for green sheet manufacture of this invention is demonstrated.

Hereinafter, the manufacturing method of the peeling film 1 of this embodiment is demonstrated.
The manufacturing method of the peeling film 1 of this embodiment is the base material preparation process which prepares the base material 11, apply | coating the smoothing layer forming composition on the 1st surface 111 of the base material 11, and a 1st application layer. Forming a smoothing layer 12 by heating and curing the first coating layer, and a release agent layer forming composition on the third surface 121 of the smoothing layer 12 Is applied to form a second coating layer, and the second coating layer is heated and cured to form a release agent layer 13.

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 on the base material 11 can be improved.

Such a surface treatment may be appropriately selected according to the type of the substrate 11 or the like. Examples of the surface treatment include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone treatment, and ultraviolet irradiation treatment. Among these, it is more preferable to use corona discharge treatment as the surface treatment because it is excellent in adhesiveness with the smoothing layer 12 and the treatment operation is simple.

<Smoothing layer forming step>
Next, the smoothing layer 12 is formed on the first surface 111 of the substrate 11.

In this step, first, a smoothing layer forming composition is prepared.
The composition for smoothing layer formation may be comprised only with the melamine resin as mentioned above. In addition to this, the composition for smoothing layer formation may be comprised with the mixture which mixed the diluent which has a hydroxyl group as mentioned above, an acidic catalyst, a solvent, and another component as needed.

Next, a liquid coating composition for forming a smoothing layer is applied onto the first surface 111 of the substrate 11 and dried to obtain a first coating layer. Here, as described above, the composition for forming a smoothing layer has appropriate fluidity. For this reason, the unevenness | corrugation of the 1st surface 111 of the base material 11 is correctly embedded by apply | coating and drying the smoothing layer forming composition on the 1st surface 111 of the base material 11, and an outer surface is smooth. 1st coating layer can be obtained.

Examples of the method for applying the smoothing layer forming composition 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, Examples include a die coating method. Among these methods, the gravure coating method and the bar coating method are more preferable as the method for applying the smoothing layer forming composition. Thereby, the 1st application layer of the target thickness can be formed easily.

Next, the smoothing layer 12 is formed by heating and curing the obtained first coating layer. By heating the first coating layer in which the irregularities of the first surface 111 are accurately embedded, the first coating layer can be cured while maintaining the smoothness of the outer surface of the first coating layer. As a result, the third surface 121 of the resulting smoothing layer 12 can be sufficiently smoothed.

Here, when the composition for smoothing layer formation contains a solvent, the 1st coating layer (the composition for smoothing layer formation is made into 1st of a board | substrate by heating and hardening a 1st coating layer. The solvent in the layer obtained by coating on the surface 111 is removed, and the smoothing layer 12 is obtained.

Although it does not specifically limit as a heating method, For example, the method etc. which heat with a hot air drying furnace etc. are mentioned.

Further, the heating conditions are not particularly limited, but the heating temperature is preferably 120 ° C. or higher and 140 ° C. or lower, and the heating time is preferably 30 seconds or longer. Thereby, it is possible to prevent the smoothing layer 12 from unintentionally deteriorating, such as a decrease in smoothness of the smoothing layer 12 due to heat shrinkage, and the smoothing layer 12 can be formed particularly efficiently. In addition, when the heating temperature is within the above range, when the smoothing layer forming composition contains a solvent or the like, the warping or cracking of the smoothing layer 12 due to evaporation of the solvent or the like during heating is prevented. Can do.

<Release agent layer forming step>
Next, the release agent layer 13 is formed on the third surface 121 of the smoothing layer 12.

In this step, first, a release agent layer forming composition is prepared.
The release agent layer forming composition may be composed of only the melamine resin and polyorganosiloxane as described above. In addition to this, the release agent layer-forming composition may comprise a mixture in which a diluent having a hydroxyl group, an acidic catalyst, a solvent, and other components as described above are mixed as necessary.

Next, a second release layer is obtained by applying a liquid release agent layer forming composition on the third surface 121 of the smoothing layer 12 and drying it.

As a method of applying the release agent layer forming composition, the method exemplified in the method of applying the smoothing layer forming composition described above can be used. Among these methods, the gravure coating method and the bar coating method are more preferable as the method for applying the release agent layer forming composition. Thereby, the 2nd application layer of the target thickness can be formed easily.

Next, the release agent layer 13 is formed by heating and curing the obtained second coating layer. Thereby, the outer surface 131 of the release agent layer 13 can be sufficiently smoothed.

Here, when a solvent is contained in the release agent layer forming composition, the second application layer (the release agent layer forming composition is smoothed layer 12 by heating and curing the second application layer). While the solvent in the layer obtained by coating on the top is removed, the release agent layer 13 is obtained.

The heating conditions are not particularly limited, but the heating temperature is preferably 120 ° C. or higher and 140 ° C. or lower, and the heating time is preferably 30 seconds or longer. Thereby, it is possible to prevent the release agent layer 13 from being unintentionally altered such as a decrease in smoothness of the release agent layer 13 due to heat shrinkage, and the release agent layer 13 can be formed particularly efficiently. In addition, when the heating temperature is within the above range, when the release agent layer forming composition contains a solvent or the like, the occurrence of warping or cracking of the release agent layer 13 due to evaporation of the solvent or the like during heating is particularly prevented. be able to.
As described above, the release film 1 can be obtained.

According to the above steps, a highly reliable release film 1 having excellent smoothness and excellent peelability can be produced 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.

≪Green sheet manufacturing method≫
Next, the manufacturing method of the green sheet of this invention is demonstrated.

The method for producing a green sheet of the present invention is a method for producing a green sheet using the release film for producing a green sheet of the present invention as described above.

Hereinafter, the manufacturing method of the green sheet of this embodiment is demonstrated.
The green sheet manufacturing method of the present embodiment provides a green sheet precursor by forming ceramic slurry (green sheet forming material) containing ceramic powder and a vehicle containing a binder on the release film 1 to form a green sheet precursor. A sheet forming material application step, and a solidification step of solidifying the green sheet precursor.

<Green sheet forming material application process>
In this step, first, when the ceramic slurry is applied on the release film 1, a ceramic slurry to be applied is prepared.

Ceramic slurry contains ceramic powder and a vehicle containing a binder.

The ceramic powder is not particularly limited, and examples thereof include powder containing alumina, zirconia, aluminum silicate, barium titanate, silicon carbide, silicon nitride, aluminum nitride and the like. As the ceramic powder, one or a combination of two or more of these can be used. Among these, barium titanate (BaTiO ₃ ) is preferable as the ceramic powder. Barium titanate has an extremely high relative dielectric constant and is effective for forming a ceramic capacitor using the obtained green sheet.

Further, the ceramic powder may further contain subcomponent materials in addition to the above-described materials.

Examples of the auxiliary component material include oxides and compounds that become oxides upon firing. Examples of the compound that becomes an oxide upon firing include carbonates, oxalates, nitrates, hydroxides, and organometallic compounds.

The shape of such ceramic powder is not particularly limited, and examples thereof include a spherical shape, an elliptical sphere shape, a scale shape, a disc shape, an elliptical disc shape, a cylindrical shape, a rectangular parallelepiped shape, and a needle shape.

When the shape of the ceramic powder is spherical, the average particle size is preferably 0.05 to 3.0 μm, and more preferably 0.1 to 0.7 μm.

Further, the method for producing the ceramic powder is not particularly limited, and examples thereof include a wet method such as a coprecipitation method, a sol-gel method, an alkali hydrolysis method, a precipitation mixing method, and a hydrothermal synthesis method, and a dry method.

For example, a ceramic powder containing barium titanate can be obtained by mixing subcomponent raw materials with barium titanate synthesized by a hydrothermal synthesis method. The ceramic powder containing barium titanate can also be obtained by a dry method in which a mixture of barium carbonate (BaCO ₃ ), titanium oxide (TiO ₂ ), and auxiliary component raw materials is calcined to cause a solid phase reaction. .

The content of the ceramic powder in the ceramic slurry is not particularly limited, but is preferably about 20 to 80% by mass.

Further, the vehicle may be an organic vehicle in which a binder is dissolved in an organic solvent, or may be an aqueous vehicle in which a water-soluble binder is dissolved in water.

The binder is not particularly limited, and examples thereof include ethyl cellulose, polyvinyl butyral, polyvinyl alcohol, cellulose, and a water-soluble acrylic resin. As the binder, one or a combination of two or more of these can be used. Of the binders described above, ethyl cellulose and polyvinyl butyral can be used as binders contained in the organic vehicle. Polyvinyl alcohol, cellulose, and water-soluble acrylic resin can be used as a binder contained in an aqueous vehicle.

Further, the content of the binder in the ceramic slurry is not particularly limited, but is preferably about 2 to 10% by mass.

The organic solvent is not particularly limited, and examples thereof include terpineol, butyl carbitol, methyl ethyl ketone, acetone, ethanol, toluene and the like. As the organic solvent, one or a combination of two or more of these can be used.

Further, the ceramic slurry may contain a plasticizer, a dispersant, a lubricant, an antistatic agent, an antioxidant and the like as necessary.

Examples of the plasticizer include polyethylene glycol and phthalic acid esters such as dioctyl phthalate and dibutyl phthalate.

When the ceramic slurry contains such a plasticizer, the content of the plasticizer in the ceramic slurry is not particularly limited, but is preferably about 0.1 to 5% by mass.

Further, examples of the dispersant include oleic acid, rosin, glycerin, octadecylamine, ethyl oleate, menseden oil and the like.

When such a dispersant is included, the content of the dispersant in the ceramic slurry is not particularly limited, but is preferably about 0.1 to 5% by mass.

Next, a ceramic slurry containing the material as described above is applied onto the outer surface 131 of the release agent layer 13 (release film 1).

Application of the ceramic slurry onto the release film 1 can be performed, for example, after the release film 1 is unwound from a roll (winding) of the release film 1 stored in a rolled state.

The ceramic slurry can be applied by, for example, a doctor blade method, a lip coat method, a roll coat method, a gravure coat method, a die coat method, or the like.

<Solidification process>
Next, the ceramic slurry applied on the release film 1 is solidified.

Solidification of the ceramic slurry can be performed by, for example, heating and drying under reduced pressure to remove the solvent and the like from the ceramic slurry.
Thereby, a green sheet is obtained.

In the production of the green sheet as described above, the green sheet is produced using the release film 1 having excellent smoothness. For this reason, according to the manufacture of the green sheet as described above, it is possible to suppress or prevent occurrence of pinholes and partial thickness variations in the green sheet.

Further, in the production of the green sheet, the green sheet is produced using the release film 1 having excellent peelability with respect to the green sheet. For this reason, when peeling the green sheet formed on the peeling film 1, it can suppress or prevent that a green sheet adheres to the peeling film 1 more than necessary. That is, it is possible to suppress or prevent the green sheet from being smoothly peeled off from the release film 1 and being damaged.

For this reason, according to the green sheet manufacturing method of manufacturing a green sheet using the release film 1, a highly reliable green sheet can be obtained easily and reliably.

≪Green sheet≫
Next, the green sheet of the present invention will be described.

The green sheet of the present invention is manufactured by using the green sheet manufacturing method of the present invention as described above.

In the present embodiment, a green sheet is obtained by the above green sheet manufacturing method using the release film 1.

The green sheet thus formed on the release film 1 is, for example, printed with a paste-like internal electrode on its surface, and is peeled from the release film 1 after being cut into a predetermined size. The peeled green sheets are laminated and then hydrostatically pressed and cut again into a predetermined shape and size. Thereafter, the green sheet can be used as a ceramic capacitor by performing a binder removal treatment, installation of external electrodes, firing, and plating treatment.

In the green sheet manufactured using the release film 1, the occurrence of pinholes and partial thickness variations is suppressed or prevented as described above. Therefore, when such a green sheet is laminated to form a ceramic capacitor, it is possible to obtain a highly reliable ceramic capacitor in which occurrence of problems due to short circuit or disconnection is prevented.

As mentioned above, although this invention was demonstrated in detail based on preferred embodiment, this invention is not limited to this. Each part which comprises the peeling film for green sheet manufacture of this invention and the green sheet of this invention can be substituted by the arbitrary structures which can exhibit the same function. Moreover, the manufacturing method of the peeling film for manufacturing the green sheet of the present invention and the manufacturing method of the green sheet of the present invention are not limited to the above-described methods, and optional steps may be added as necessary. .

For example, in the above-described embodiment, the base material has been described as a single layer structure, but is not limited thereto. For example, the substrate may have a multilayer structure of two or more layers of the same type or different types. Similarly, the smoothing layer and the release agent layer have been described as single-layer structures, but are not limited thereto. For example, each of the smoothing layer and the release agent layer may have a multilayer structure of two or more layers of the same type or different types.

In the embodiment described above, the release film for producing a green sheet has been described as a three-layer structure in which a base material, a smoothing layer, and a release agent layer are joined and laminated in this order. Not. For example, an intermediate layer may be provided between the base material and the smoothing layer. Further, an intermediate layer may be provided between the smoothing layer and the release agent layer. Such an intermediate layer may have a function of improving the adhesion of each layer. Further, the intermediate layer may have a function of further suppressing the generation of charging when the release film for producing a green sheet before forming the green sheet is wound up.

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

[1] Production of release film for green sheet production (Example 1)
First, a biaxially stretched polyethylene terephthalate film as a substrate [thickness: 31 μm, arithmetic average roughness Ra ₂ of the first surface: 23 nm, maximum protrusion height Rp _{2 of} the first surface: 415 nm, of the second surface Arithmetic average roughness Ra ₃ : 23 nm, maximum protrusion height Rp ₃ : 415 nm on the second surface] was prepared.

Next, melamine resin [Mitsui Cytec Co., Ltd., trade name “Cymel 303”, hexamethoxymethyl melamine, mass average molecular weight 390, solid content 100% by mass]: 100 parts by mass, p-toluenesulfonic acid as an acidic catalyst: 5 A composition for forming a smoothing layer having a solid content of 15% by mass was obtained by mixing part by mass and a mixed solvent of isopropyl alcohol and isobutyl alcohol (mass ratio 4/1).

Next, the obtained composition for forming a smoothing layer was applied onto the first surface 111 of the substrate 11 with a bar coater to obtain a first coating layer. Next, the smoothing layer (thickness: 0.55 μm) was formed by curing the first coating layer by heating the first coating layer at 120 ° C. for 1 minute.

Next, melamine resin [Mitsui Cytec Co., Ltd., trade name “Cymel 303”, hexamethoxymethylmelamine, mass average molecular weight 390, solid content 100% by mass]: 95 parts by mass, silanol-terminated polydimethylsiloxane as a silicone compound [Shin-Etsu Chemical Industry Co., Ltd., KF-9701, solid content 100% by weight]: 5 parts by mass, p-toluenesulfonic acid as an acidic catalyst: 5 parts by mass, and a mixed solvent of isopropyl alcohol and isobutyl alcohol (mass ratio) 4/1) was mixed to obtain a release agent layer-forming composition having a solid content of 15% by mass.

Next, the obtained release agent layer-forming composition was applied onto the third surface (the surface opposite to the substrate) of the smoothing layer with a bar coater to obtain a second coating layer. Next, the release agent layer (thickness: 0.50 μm) was formed by curing the second application layer by heating the second application layer at 120 ° C. for 1 minute.

(Example 2)
A release film for producing a green sheet was produced in the same manner as in Example 1 except that the smoothing layer forming composition and the release agent layer forming composition obtained as described below were used.

Melamine resin [Made by Mitsui Cytec Co., Ltd., trade name “Cymel 303”, hexamethoxymethyl melamine, mass average molecular weight 390, solid content 100% by mass]: 65 parts by mass and glycol compound [2-methyl-1, 3-propanediol, manufactured by Tokyo Chemical Industry Co., Ltd., mass average molecular weight 90, solid content 100%]: 30 parts by mass, p-toluenesulfonic acid as an acidic catalyst: 5 parts by mass, isopropyl alcohol and isobutyl alcohol And a mixed solvent (mass ratio 4/1) were mixed to obtain a composition for forming a smoothing layer having a solid content of 15% by mass.

Further, melamine resin [Mitsui Cytec Co., Ltd., trade name “Cymel 303”, hexamethoxymethyl melamine, mass average molecular weight 390, solid content 100% by mass]: 65 parts by mass and glycol compound [2-methyl- 1,3-propanediol, manufactured by Tokyo Chemical Industry Co., Ltd., mass average molecular weight 90, solid content 100%]: 30 parts by mass of silanol-terminated polydimethylsiloxane as a silicone compound [manufactured by Shin-Etsu Chemical Co., Ltd., KF-9701, solid content 100% by mass]: 5 parts by mass, p-toluenesulfonic acid as an acidic catalyst: 5 parts by mass, and a mixed solvent of isopropyl alcohol and isobutyl alcohol (mass ratio 4/1). By mixing, a composition for forming a release agent layer having a solid content of 15% by mass was obtained.

Example 3
Biaxially stretched polyethylene terephthalate film as a substrate [thickness: 31 μm, arithmetic average roughness Ra _{2 of} first surface: 19 nm, maximum protrusion height Rp _{2 of} first surface: 216 nm, arithmetic average of second surface A release film for producing a green sheet was produced in the same manner as in Example 1 except that the roughness Ra ₃ : 19 nm and the maximum projection height Rp _{3 of} the second surface Rp ₃ : 216 nm were used.

(Examples 4 to 6)
A release film for producing a green sheet was produced in the same manner as in Example 1 except that the thickness of each layer (smoothing layer and release agent layer) was changed as shown in Table 1.

(Comparative Example 1)
A release film for producing a green sheet was produced in the same manner as in Example 1 except that the smoothing layer was not provided.

(Comparative Example 2)
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 was changed to 0.20 μm.

(Comparative Example 3)
A release film for producing a green sheet was produced in the same manner as in Example 1 except that the release agent layer forming composition obtained as described below was used.

Melamine resin [Mitsui Cytec Co., Ltd., trade name “Cymel 303”, hexamethoxymethylmelamine, mass average molecular weight 390, solid content 100% by mass]: 99 parts by mass, silanol-terminated polydimethylsiloxane as a silicone compound [Shin-Etsu Chemical Manufactured by KF-9701, solid content: 100% by mass]: 1 part by mass, p-toluenesulfonic acid as an acidic catalyst: 5 parts by mass, and a mixed solvent of isopropyl alcohol and isobutyl alcohol (mass ratio 4/1) And a release agent layer forming composition having a solid content of 15% by mass.

(Comparative Example 4)
A release film for producing a green sheet was produced in the same manner as in Example 1 except that the release agent layer forming composition obtained as described below was used.

Melamine resin [Mitsui Cytec Co., Ltd., trade name “Cymel 303”, hexamethoxymethylmelamine, mass average molecular weight 390, solid content 100% by mass]: 80 parts by mass, silanol-terminated polydimethylsiloxane as a silicone compound [Shin-Etsu Chemical Manufactured by KF-9701, solid content: 100% by mass]: 20 parts by mass, p-toluenesulfonic acid as an acidic catalyst: 5 parts by mass, and a mixed solvent of isopropyl alcohol and isobutyl alcohol (mass ratio 4/1) And a release agent layer forming composition having a solid content of 15% by mass.

(Comparative Example 5)
A release film for producing a green sheet was produced in the same manner as in Example 1 except that the smoothing layer forming composition and the release agent layer forming composition obtained as described below were used.

Mixture of stearyl modified alkyd compound and methylated melamine compound [manufactured by Hitachi Chemical Co., Ltd., trade name “Tesfine 303”, mass average molecular weight 15000, solid content 48% by mass]: 100 parts by mass and p as an acidic catalyst -Toluenesulfonic acid: 3 parts by mass and a mixed solvent of isopropyl alcohol and isobutyl alcohol (mass ratio 4/1) were mixed to obtain a composition for forming a smoothing layer having a solid content of 15% by mass.

Further, a mixture of a stearyl-modified alkyd compound and a methylated melamine compound [manufactured by Hitachi Chemical Polymer Co., Ltd., trade name “Tesfine 303”, mass average molecular weight 15000, solid content 48% by mass]: 100 parts by mass and a silicone compound Silanol-terminated polydimethylsiloxane (manufactured by Shin-Etsu Chemical Co., Ltd., KF-9701, solid content: 100% by mass): 2.53 parts by mass, p-toluenesulfonic acid as an acidic catalyst: 3 parts by mass, and isopropyl alcohol And a mixed solvent of isobutyl alcohol (mass ratio 4/1) were mixed to obtain a release agent layer forming composition having a solid content of 15% by mass.

(Comparative Example 6)
A release film for producing a green sheet was produced in the same manner as in Example 1 except that the smoothing layer forming composition and the release agent layer forming composition obtained as described below were used.

Polyester compound [manufactured by Toyobo Co., Ltd., trade name “Byron 20SS”, solid content 30% by mass, weight average molecular weight 3000]: 80 parts by mass, methylated melamine compound as a crosslinking agent [manufactured by Hitachi Chemical Co., Ltd., Product name “Tesfine 200”, solid content 80 mass%]: 20 mass parts mixture: 100 mass parts, p-toluenesulfonic acid as acidic catalyst: 3 mass parts, mixed solvent of toluene and methyl ethyl ketone (mass) Ratio 1/1) was mixed to obtain a composition for forming a smoothing layer having a solid content of 15% by mass.

In addition, polyester compound [manufactured by Toyobo Co., Ltd., trade name “Byron 20SS”, solid content 30% by mass, mass average molecular weight 3000]: 80 parts by mass, methylated melamine compound [Hitachi Chemical Polymer Co., Ltd.] Product name “Tesfine 200”, solid content 80 mass%]: 20 mass parts mixture: 95 mass parts and silanol-terminated polydimethylsiloxane as a silicone compound [manufactured by Shin-Etsu Chemical Co., Ltd., KF-9701, Solid content 100% by mass]: 2.1 parts by mass, p-toluenesulfonic acid as an acidic catalyst: 3 parts by mass, and a mixed solvent of toluene and methyl ethyl ketone (mass ratio 1/1) were mixed to form a solid A composition for forming a release agent layer having a content of 15% by mass was obtained.

(Comparative Example 7)
A release film for producing a green sheet was produced in the same manner as in Example 1 except that the smoothing layer forming composition and the release agent layer forming composition obtained as described below were used.
100 parts by mass of linear octylated melamine resin [trade name “RP-30”, manufactured by Sanba Laboratory, solid content concentration 30% by mass, mass average molecular weight 2000], and 5 parts by mass of p-toluenesulfonic acid as an acidic catalyst And a mixed solvent of toluene / methyl ethyl ketone (mass ratio 1/1) were mixed to obtain a composition for forming a smoothing layer having a solid content of 15% by mass.

Also, 100 parts by mass of linear octylated melamine form resin (trade name “RP-30”, manufactured by Sanba Laboratory, solid content concentration 30% by mass, mass average molecular weight 2000) and silanol-terminated polydimethylsiloxane as a silicone compound [Manufactured by Shin-Etsu Chemical Co., Ltd., KF-9701, solid content: 100% by mass]: 1.58 parts by mass, 5 parts by mass of p-toluenesulfonic acid as an acidic catalyst, and a mixed solvent of toluene / methyl ethyl ketone (mass Ratio 1/1) was mixed to obtain a release agent layer-forming composition having a solid content of 15% by mass.

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

In Table 1, melamine resin [trade name “Cymel 303” manufactured by Mitsui Cytec Co., Ltd., hexamethoxymethyl melamine, mass average molecular weight 390, solid content 100% by mass] is “A1”, glycol compound [2-methyl-1 , 3-propanediol, manufactured by Tokyo Chemical Industry Co., Ltd., weight average molecular weight 90, solid content 100%] is “A2”, a mixture of stearyl-modified alkyd compound and methylated melamine compound [manufactured by Hitachi Chemical Co., Ltd., trade name “ "Tesfine 303", mass average molecular weight 15000, solid content 48% by mass] "A3", polyester compound [manufactured by Toyobo Co., Ltd., trade name "Byron 20SS", solid content 30% by mass, mass average molecular weight 3000] 80 Part by mass and methylated melamine compound as a crosslinking agent [manufactured by Hitachi Chemical Polymer Co., Ltd., trade name “Tesfine 2 0 ”, solid content 80% by mass”: 20 parts by mass of a mixture of “A4”, linear octylated melamine resin [trade name “RP-30” manufactured by Sanba Laboratory, solid content concentration 30% by mass, mass average Molecular weight 2000] was indicated as “A5”.
Moreover, in Table 1, each content rate of a thermosetting resin, a reactive diluent, and polyorganosiloxane is the ratio of the thermosetting resin and the reactive diluent in the whole composition for smoothing layer formation (solid content). And the ratio of the thermosetting resin, the reactive diluent and the polyorganosiloxane in the entire composition (solid content) for forming the release agent layer.

In each example and each comparative example, the average film thicknesses of the substrate, the smoothing layer, and the release agent layer were measured with a reflective film thickness meter “F20” (manufactured by Filmetrics Co., Ltd.). In addition, the said average film thickness measured the film thickness in arbitrary 12 places in the base material etc. which were cut | judged to 10 mm x 100 mm using the said reflection-type film thickness meter, and is the maximum value among the measured 12 places values. And a value obtained by calculating an average value of 10 values excluding the minimum value.

In each example and each comparative example, 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 of the second surface of the base material Height Rp ₃ , arithmetic average roughness Ra ₄ and maximum protrusion height Rp ₄ of the third surface of the smoothing layer, and arithmetic average roughness Ra ₁ and maximum protrusion height Rp ₁ of the outer surface of the release agent layer Each was measured as follows. First, a double-sided tape was affixed to a glass plate. Next, a substrate is fixed on the double-sided tape so that the surface opposite to the surface to be measured is the glass plate side, and an optical interference type surface shape observation device (product surface “WYKO-1100”, stock Measured using a company Veeco). The measurement conditions were PSI mode, 50 magnification, and measurement range: 91.2 × 119.8 μm.

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

[2.1] Evaluation of slurry coating property Barium titanate powder [manufactured by Sakai Chemical Industry Co., Ltd., trade name “BT-03”, BaTiO ₃ ]: 100 parts by mass and polyvinyl butyral as a binder [manufactured by Sekisui Chemical Co., Ltd., Trade name “ESREC B / K BM-2”]: 8 parts by mass and dioctyl phthalate as a plasticizer [manufactured by Kanto Chemical Co., Ltd., trade name “dioctyl phthalate deer grade 1”]: 4 parts by mass To obtain a mixture. This mixture: 12 parts by mass and toluene / ethanol mixed solvent (mass ratio 6/4): 135 parts by mass were mixed and dispersed by a ball mill to prepare a ceramic slurry.

Next, the ceramic slurry is placed on the outer surface of the release film (outer surface of the release agent layer) obtained in each example and each comparative example with a die coater so that the thickness of the green sheet becomes 1 μm. Then, coating was performed over a width of 250 mm and a length of 10 m to form a green sheet precursor. The green sheet precursor was dried at 80 ° C. for 1 minute. Thereby, the peeling film in which the green sheet was formed on the outer surface was obtained.

Thereafter, the release film on which the green sheet was formed was irradiated with light from the release film side with a fluorescent lamp, the green sheet surface was visually observed, and the coating property of the slurry was evaluated according to the following criteria.

A: There was no pinhole in the green sheet.
B: 1 to 5 pinholes were found on the green sheet.
C: Six or more pinholes were found on the green sheet.

[2.2] Evaluation of green sheet peelability The green sheet formed in [2.1] was peeled from the release film, and the peelability of the green sheet was evaluated according to the following criteria.

A: The green sheet was peeled off smoothly without tearing. Further, no green sheet remained on the release agent layer.

B: The green sheet was not torn, but it could be peeled off with a little smoothness, and no green sheet remained on the release agent layer.

C: When the green sheet was peeled off, the green sheet was torn or could not be peeled off.

[2.3] Evaluation of defects in release agent layer (Evaluation of number of recesses in release agent layer)
A polyvinyl butyral resin was dissolved in a toluene / ethanol mixed solvent (mass ratio 6/4) to obtain a coating solution. This coating solution was applied on the outer surface of the release film (outer surface of the release agent layer) obtained in each Example and Comparative Example so that the polyvinyl butyral resin layer had a thickness of 3 μm. A butyral resin layer precursor was formed. Thereafter, the polyvinyl butyral resin layer precursor was dried at 80 ° C. for 1 minute to form a polyvinyl butyral resin layer on the release film.

Next, a polyester adhesive tape [manufactured by Nitto Denko Corporation, product name: No. 31B] was pasted.

Next, the polyvinyl butyral resin layer was transferred to a polyester tape by peeling the release film from the polyvinyl butyral resin layer.

Next, the surface (observation surface) of the polyvinyl butyral resin layer on the side of the release film that was in contact with the release agent layer was observed using a light interference type surface shape observation apparatus “WYKO-1100” [manufactured by Veeco Co., Ltd.]. did. Specifically, by counting recesses having a depth of 150 nm or more to which the shape of the release agent layer was transferred within a range of 91.2 × 119.8 μm on the observation surface in PSI mode and 50 magnifications, The number of recesses in the release agent layer was evaluated based on the judgment criteria.

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.

In addition, when a green sheet was produced using the release film for producing a green sheet evaluated as the standard C and a capacitor was produced using the green sheet, there was a tendency that a short circuit due to a decrease in withstand voltage was likely to occur.
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 coating property of the ceramic slurry and the peelability of the formed green sheet. Moreover, from the evaluation of the number of recesses of the release agent layer, it was found that the release film for producing a green sheet of the present invention has an effect of suppressing the occurrence of pinholes and partial thickness variations in the green sheet. On the other hand, satisfactory results were not obtained in the comparative example.

The release film for producing a green sheet of the present invention includes a base material having a first surface and a second surface, a smoothing layer provided on the first surface side of the base material, and the smoothing layer. A release agent layer provided on the surface opposite to the substrate, and the smoothing layer is a smoothing layer forming composition comprising a melamine resin having a mass average molecular weight of 950 or less as a main component. It is formed by heating and curing, and the release agent layer is formed by heating and curing a release agent layer forming composition containing melamine resin as a main component and containing polyorganosiloxane. 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. . Thereby, the peeling film for green sheet manufacture which can manufacture a reliable green sheet can be provided. Therefore, the present invention has industrial applicability.

1 ... Release film for green sheet production (release film)
11 ... substrate 111 ... first surface 112 ... second surface (back surface of release film)
12 ... Smoothing layer 121 ... 3rd surface (surface opposite to the base material of a smoothing layer)
13 ... Release agent layer 131 ... Outer surface of release agent layer

Claims

A release film used in the manufacture of green sheets,
A substrate having a first surface and a second surface;
A smoothing layer provided on the first surface side of the substrate;
A release agent layer provided on the surface side of the smoothing layer opposite to the base material,
The smoothing layer is formed by heating and curing a composition for forming a smoothing layer containing a melamine resin having a mass average molecular weight of 950 or less as a main component,
The release agent layer is formed by heating and curing a release agent layer forming composition containing a melamine resin as a main component and containing polyorganosiloxane,
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.
The smoothing layer forming composition contains a solid content, and the content of the melamine resin having a mass average molecular weight of 950 or less in the solid content of the smoothing layer forming composition is more than 50% by mass. A release film for producing a green sheet according to claim 1.
The said release agent layer forming composition contains solid content, and content of the said melamine resin in the said solid content of the said release agent layer forming composition is 60 mass% or more. Release film for manufacturing green sheets.
The release film for producing a green sheet according to any one of claims 1 to 3, wherein the composition for forming a smoothing layer further contains a glycol compound.
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 0.3 to 2 µm.
6. The release film for producing a green sheet according to claim 1, wherein the release agent layer has an average film thickness of 0.3 to 2 μm.
It is a manufacturing method of the peeling film for green sheet manufacture of any one of Claim 1 thru | or 6, Comprising:
A base material preparation step of preparing the base material having a first surface and a second surface;
The smoothing layer forming composition is applied to the first surface side of the base material to form the first coating layer, and then the first coating layer is heated and cured to cure the smoothness. A smoothing layer forming step of forming a condensing layer;
The second coating layer is formed by applying the release agent layer forming composition on the surface of the smoothing layer opposite to the base material, and then heating and curing the second coating layer. A release agent layer forming step of forming the release agent layer,
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. Method for producing a release film.
A green sheet precursor is formed by applying a green sheet forming material containing ceramic powder and a vehicle containing a binder onto the release film for producing a green sheet according to any one of claims 1 to 6. A green sheet forming material application step;
And a solidifying step for solidifying the green sheet precursor.
A green sheet produced by the method for producing a green sheet according to claim 8.