TWI551458B - Release film for producing green sheet and method of producing release film for producing green sheet - Google Patents

Description

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

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

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

In general, a release film for producing a green sheet is composed of a substrate and a release agent layer. The ceramic slurry is coated on the release film for producing a green sheet and dried to produce a green sheet which is dispersed and dissolved in an organic solvent to dissolve the ceramic particles and the binder resin. Next, the produced green sheet was peeled off from the release film for green sheet production and used for the production of a ceramic capacitor.

In the process of manufacturing a green sheet using a release film by the conventional green sheet manufacturing, the surface unevenness state of the release film for producing a green sheet is transferred to the green sheet, and pinholes are formed on the surface of the green sheet. problem. As a result, in the ceramic capacitor manufactured by stacking such a green sheet, a problem of malfunction due to a short circuit occurs. In order to solve such a problem, it is necessary to mold the surface of the release film for green sheet production (casting) Surface preparation) requires very high smoothness.

Therefore, there has been proposed a method for producing a release film for producing a green sheet having a smooth surface which is attached to one surface of a substrate sheet having a fine uneven state on the surface by applying a heat-hardening resin liquid and heating the same A thermosetting resin layer is provided to be hardened, and a release agent is applied to the thermosetting resin layer to form a release agent layer (see, for example, Patent Document 1, Japanese Patent Laid-Open Publication No. 2007-069360).

Furthermore, in recent years, with the miniaturization and high density of ceramic capacitors, it has been demanded that green sheets must be more thinned. However, when a thin green sheet is produced by using a conventional release film for producing a green sheet, pinholes are formed on the surface of the green sheet, and it is difficult to obtain a green sheet of high reliability.

An object of the present invention is to provide a release film for producing a green sheet which can prevent pinholes or partial thickness from being uneven on the surface of the green sheet, and can produce a green sheet of high reliability. Further, another object of the present invention is to provide a method for producing a release film for producing a green sheet which can prevent pinholes or partial unevenness from occurring on the surface of the green sheet.

The object is achieved by the present invention (1) to (8) below.

(1) A release film for producing a green sheet, comprising a substrate, a smoothing layer, and a release agent layer. The substrate has a first surface and a second surface. The smoothing layer is disposed on the aforementioned first surface of the substrate. The release agent layer is disposed on a surface of the smoothing layer opposite to a surface of the substrate. The smoothing layer is formed by irradiating an active energy ray and hardening a composition for forming a smoothing layer containing one active energy ray-curable compound. From one of the outer surface of one layer form an arithmetic average roughness Ra ₁ of 8nm or less and the layer formed from the outer surface of one of the maximum projection height Rp ₁ is 50nm or less.

(2) The release film for producing a green sheet according to the above (1), wherein the first surface has an arithmetic mean roughness Ra ₂ of 10 to 200 nm, and one of the first surfaces has a maximum protrusion height Rp ₂ It is 80~1000nm.

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

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

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

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

(7) The release film for producing a green sheet according to any one of the above (1), wherein the second surface has an arithmetic mean roughness Ra ₃ of 10 to 200 nm, and the second One of the surfaces has a maximum protrusion height Rp ₃ of 80 to 1000 nm.

(8) The method for producing a release film for producing a green sheet according to any one of the above (1) to (7), comprising a substrate preparation process, a coating layer formation process, and a smoothing layer formation process And a release agent layer forming process. The substrate preparation process is to prepare the substrate, and the substrate has the first surface and the second surface. The coating layer forming process forms a coating layer by applying the composition for forming a smoothing layer containing the active energy ray-curable compound to the first surface position of the substrate. The smoothing layer forming process forms the smoothing layer by irradiating and hardening the coating layer with the active energy ray. The release agent layer forming process is performed on the surface of the smoothing layer opposite to the surface of the substrate to form the release agent layer. The arithmetic mean 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.

According to the present invention, it is possible to provide a release film for producing a green sheet which can prevent pinholes or partial thickness from being uneven on the surface of the green sheet, and can produce a green sheet of high reliability. In particular, even if a substrate having a large surface roughness is used as a substrate constituting a release film for producing a green sheet, it is possible to provide a release film for producing a green sheet having excellent outer surface smoothness. When such a release film for producing a green sheet is used, it is possible to prevent pinholes or partial thickness from being uneven on the surface of the green sheet. As a result, when the green sheets are stacked to form a capacitor, the problem of malfunction due to the short circuit can be prevented. According to the present invention, it is possible to easily produce a release film for producing a green sheet, which is capable of producing a green sheet having excellent surface smoothness.

1‧‧‧Folding film for green sheet manufacturing

11‧‧‧Substrate

111‧‧‧The first surface of the substrate

112‧‧‧Second surface of the substrate

12‧‧‧Smoothing layer

121‧‧‧ surface (third surface)

13‧‧‧ release agent layer

131‧‧‧Outer surface of the release agent layer

Fig. 1 is a side sectional view showing a release film for producing a green sheet of the present invention.

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

The release film for green sheet production will be described below.

The release film for producing a green sheet of the present invention is used to produce a green sheet. Moreover, the green sheets produced are used, for example, for the manufacture of ceramic capacitors and the like.

Fig. 1 is a side sectional view showing a release film for producing a green sheet of the present invention. Further, in the following description, the upper side of the first drawing is indicated by "upper" and the lower side is indicated by "lower".

As shown in Fig. 1, the release film 1 for green sheet production has a substrate 11, a smoothing layer 12, and a release agent layer 13. The substrate 11 has a first surface 111 and a second surface 112. The smoothing layer 12 is disposed on the first surface 111 of the substrate 11. The release agent layer 13 is disposed at a position opposite to the surface 121 of the substrate 11 of the smoothing layer 12. In other words, as shown in Fig. 1, the release film 1 for producing a green sheet is a three-layer structure in which the base material 11, the smoothing layer 12, and the release agent layer 13 are stacked in this order.

Further, in the present specification, in the case where a green sheet is produced using the release film 1 for green sheet production, the green sheet is coated with a dissolved ceramic slurry, for example, on the outer surface 131 of the release agent layer 13. The way is formed.

In the present invention, the release film 1 for producing a green sheet has a substrate 11, a release agent layer 13, and a smoothing layer 12 interposed therebetween. Further, the release film 1 for producing a green sheet of the present invention has the following feature, and the smoothing layer 12 is formed by irradiating an active energy ray and hardening a composition for forming a smoothing layer containing an active energy ray-curable compound. material is formed from one of 131 arithmetic average roughness Ra than 13 formed on the surface layer ₁ of 8nm or less and the releasing agent layer 13 than the surface of one 131 maximum projection height Rp of ₁ to 50nm or less.

According to such a feature, the smoothness of the outer surface 131 of the release agent layer 13 can be improved, and the release film 1 for producing a green sheet excellent in release property can be obtained. When the green sheet is produced by using the release film 1 for green sheet production, it is possible to prevent pinholes or partial thickness from being uneven on the surface of the green sheet, and it is possible to manufacture a green sheet of high reliability. As a result, when the green sheets are stacked to form a capacitor, the problem of malfunction due to the short circuit can be prevented.

Incidentally, as the film body of the substrate 11, it is possible to have various surface roughnesses. The surface roughness of an inexpensive film body tends to be rough. Even when a release film having a rough surface roughness is used to form a release film for producing a green sheet, it is possible to surely fill (eliminate) the surface of the substrate by providing a smoothing layer having the above-described characteristics on the surface of the substrate. The bump state. As a result, the surface of the smoothing layer opposite to the substrate can be made smooth. Thereby, it is possible to prevent the uneven state 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 producing a green sheet excellent in surface smoothness other than the release agent layer. .

Hereinafter, the constituent green sheet system of the present embodiment will be described in order. The layers of the release film are used.

The substrate 11 will be explained below.

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

As shown in FIG. 1, the substrate 11 has a first surface 111 and a second surface 112.

The material constituting the substrate 11 is not particularly limited, and may be, for example, a polybutylene terephthalate (PBT) resin or a polyethylene terephthalate (PET) resin. Polyester resin such as polyethylene naphthalate (PEN) resin, polyolefin such as polypropylene (PP) resin and polymethylpentene (PMP) resin (polyolefin) resin and polycarbonate (Polycarbonate, PC) resin and other plastic film. The substrate 11 can be a single layer film or a multilayer film of two or more layers of the same type or different types. Among them, a polyester film is preferred, a polyethylene terephthalate film is preferred, and a biaxially stretched polyethylene terephthalate film is preferred. In particular, the polyester film is less prone to dust during processing and during use. For this reason, for example, in the case of producing a green sheet using the release film 1 made of a polyester resin, it is possible to effectively prevent coating failure of the ceramic slurry due to dust. As a result, a green sheet having fewer pinholes can be produced.

Further, the substrate 11 may contain a filler or the like in addition to the above materials. The filler can use silica, titania, calcium carbonate, One or a combination of two or more of kaolin and alumina. By including such a filler, mechanical strength can be simultaneously imparted to the substrate 11, and the smoothness of the surface and the back surface of the substrate 11 can be improved, and blocking can be suppressed.

Further, the arithmetic mean roughness Ra ₂ of the first surface 111 of the substrate 11 is preferably 10 to 200 nm, and the maximum protrusion height Rp ₂ is preferably 80 to 1000 nm.

Furthermore, the arithmetic mean roughness Ra _{2 of the} first surface 111 is preferably 15 to 100 nm, and the arithmetic mean roughness Ra _{2 of the} first surface 111 is preferably 20 to 50 nm. Further, the maximum protrusion height Rp _{2 of the} first surface 111 is preferably 90 to 800 nm, and the maximum protrusion height Rp _{2 of the} first surface 111 is preferably 100 to 600 nm.

When the arithmetic mean roughness Ra ₂ and the maximum protrusion height Rp _{2 of the} first surface 111 fall within the above range, even if the film thickness of the smoothing layer 12 to be described later is relatively thin, the first substrate 11 can be more reliably filled. The uneven state of the surface 111 makes it possible to make the surface 121 of the smoothing layer 12 opposite to the substrate 11 smoother. As a result, it is possible to more reliably prevent the uneven state of the first surface 111 of the substrate 11 from affecting the outer surface 131 of the release agent layer 13 formed on the smoothing layer 12.

Further, the substrate 11 having the arithmetic mean roughness Ra _{2 of the} first surface 111 and its maximum protrusion height Rp ₂ falling within the above range is easily obtained at a relatively low price.

On the other hand, when the arithmetic mean roughness Ra ₂ and the maximum protrusion height Rp _{2 of the} first surface 111 exceed the above upper limit, it is difficult to sufficiently fill the first surface according to the constituent material of the composition for forming a smoothing layer. In the uneven state of 111, it is necessary to make the film thickness of the release agent layer 13 thick.

Further, in the present specification, the arithmetic mean roughness Ra ₂ and the maximum protrusion height Rp ₂ of the first surface 111 of the substrate 11 are Mitutoyo according to Japanese Industrial Standards (JIS) B0601-1994. The value obtained by measuring the manufactured surface roughness measuring machine SV3000S4 (stylus type). In addition, in the present specification, unless otherwise specified, "arithmetic average roughness and maximum protrusion height" refer to values obtained by the above-described methods.

Further, the arithmetic mean roughness Ra ₃ of the second surface 112 of the substrate 11 is preferably 10 to 200 nm, and the maximum protrusion height Rp ₃ is preferably 80 to 1000 nm. Furthermore, the arithmetic mean roughness Ra _{3 of the} second surface 112 is preferably 15 to 100 nm, and the arithmetic average roughness Ra _{3 of the} second surface 112 is preferably 20 to 50 nm. Further, the maximum protrusion height Rp _{3 of the} second surface 112 is preferably 90 to 800 nm, and the maximum protrusion height Rp _{3 of the} second surface 112 is preferably 100 to 600 nm.

When the arithmetic mean roughness Ra ₃ and the maximum protrusion height Rp _{3 of the} second surface 112 fall within the above range, it is possible to appropriately prevent the occurrence of curl slip when the release film 1 is wound into a roll shape. Further, it is also possible to prevent the occurrence of agglomeration when the release film 1 is wound into a roll shape to be stored. Specifically, the release film 1 can be wound around a core material such as paper, plastic, or metal so that the release agent layer 13 faces inward as needed, and is stored in a roll shape. At this time, if the arithmetic mean roughness Ra ₃ and the maximum protrusion height Rp _{3 of the} second surface 112 fall within the above range, the air can be sufficiently removed when the release film 1 is wound into a roll shape, and the curl slip can be effectively suppressed. The situation. Therefore, when the release film 1 is wound into a roll shape, it is not necessary to increase the tension of the winding, and deformation of the core portion due to the tension of the winding can be suppressed. Further, in the roll-shaped release film 1, if the arithmetic mean roughness Ra ₃ and the maximum protrusion height Rp _{3 of the} second surface 112 fall within the above range, the release agent layer 13 can be more effectively prevented. The agglomeration phenomenon occurs when the second surface 112 of the substrate 11 is bonded to each other. Therefore, the roll-shaped release film 1 can be easily unwound.

On the other hand, if the arithmetic mean roughness Ra ₃ and the maximum protrusion height Rp _{3 of the} second surface 112 do not reach the aforementioned lower limit value, when the release film 1 is wound into a roll shape, the surface and the back surface of the release film 1 ( The second surface 112 of the substrate 11 and the outer surface 131 of the release agent layer 13 may be prone to agglomeration. Further, the average film thickness of the substrate 11 is not particularly limited, but is preferably 10 to 300 μm, and more preferably 15 to 200 μm. Thereby, the release film 1 can have moderate flexibility, and at the same time has particularly excellent tear resistance and breakage resistance.

The smoothing layer 12 will be explained below.

The smoothing layer 12 is opposite to the outer surface 131 of the release agent layer 13 and has a function of slowing down the influence of the uneven state of the first surface 111 of the substrate 11.

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

The smoothing layer 12 is formed by applying a smoothing layer forming composition onto the first surface 111 of the substrate 11 and irradiating with an active energy ray to cure the obtained coating layer.

The composition for forming a smoothing layer contains an active energy ray-curable compound which is cured by irradiation with an active energy ray.

Further, the composition for forming a smoothing layer before the irradiation of the active energy ray is present in an unhardened state or a semi-hardened state at room temperature.

Further, when such a composition for forming a smoothing layer is applied onto the first surface 111 of the substrate 11, it has a moderate fluidity. Therefore, when such a composition for forming a smoothing layer is used, it is possible to easily fill the uneven state of the first surface 111 of the substrate 11, and it is possible to surely maintain the filled state. As a result, it is possible to prevent the uneven state of the substrate 11 from affecting the position of the smoothing layer 12 opposite to the surface 121 of the substrate 11 (hereinafter sometimes referred to as the "third surface 121"), and it is possible to smooth The third surface 121 of the layer 12 becomes smooth. Therefore, the outer surface 131 of the release agent layer 13 formed on the third surface 121 of the smoothing layer 12 can be made smoother.

In another example, the active energy ray-curable compound may be an ultraviolet curable compound which is cured by irradiation with ultraviolet rays, an infrared curable compound which is cured by irradiation of infrared rays, and an X-ray hardening compound which is hardened by irradiation of X-rays. An electron beam curing type compound which is cured by irradiation with an electron beam and a visible light curing type compound which is cured by irradiation with visible light. Among them, an ultraviolet curable compound is particularly preferred. The ultraviolet curable compound has moderate fluidity. Thereby, a smooth surface state can be formed in such a manner that the composition for forming a smoothing layer is applied onto the first surface 111 of the substrate 11. Therefore, even if the smoothing layer 12 is formed to be relatively thin, it is possible to surely fill the uneven state of the first surface 111 of the substrate 11. As a result, it is possible to more easily make the third surface 121 of the smoothing layer 12 smooth.

The active energy ray-curable compound which can be cured by irradiation with an active energy ray such as an ultraviolet ray or an electron beam can use a compound having two or more polymerizable unsaturated groups in the molecule. For example, it may be a urethane acrylate compound, a polyfunctional acrylate compound, a polyester acrylate compound, or an epoxy acrylate system. A compound, a compound such as a polyol acrylate compound. Among them, a urethane acrylate compound is preferred.

For example, a urethane acrylate compound can be oligomerized by a polyether polyol or a polyester polyol and a polyisocyanate. The polyurethane oligomer is obtained by esterification reaction with (meth)acrylic acid. Specifically, it may be a Phenyl glycidyl ether acrylate hexamethylene diisocyanate urethane prepolymer or a pentaerythritol triacrylate hexamethylene group. Pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol triacrylate toluene diisocyanate urethane prepolymer, pentaerythritol triacrylate Ketone diisocyanate urethane (pentaerythritol triacrylate isophorone diisocyanate urethane) prepolymer, dipentaerythritol pentaacrylate hexamethylene diisocyanate urethane prepolymer and the like.

For example, the polyfunctional acrylate compound may be 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(methyl) Acetylene (1,6-hexanediol di(metha)acrylate), neopentyllglycol di(meth)acrylate, polyethylene glycol di(meth)acrylate (polyethylene glycol) Di(metha)acrylate), neopentyllgic acid adipate di(meth)acrylate, dicyclopentanyl di(metha)acrylate ), allyl cyclohexyl di (metha) acrylate, isocyanurate di (metha) acrylate trimethylolpropane Trimethylol propane tri(metha)acrylate, dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate ), tris(acryloxyethyl)isocyanurate, dipentaerythritol Yl) acrylate (dipentaerythritol hexa (metha) acrylate) and the like compounds.

For example, the polyester acrylate-based compound can be a polyester oligomer having a hydroxyl group at both ends thereof by condensing a polyvalent carboxylic acid with a polyvalent alcohol. a compound obtained by esterification of a hydroxyl group of (polyester oligomer) with (meth)acrylic acid, or a hydroxyl group at the terminal of an oligomer (oligomer) obtained by adding an alkylene oxide to a polyvalent carboxylic acid A compound obtained by esterification reaction with (meth)acrylic acid.

For example, the epoxy acrylate-based compound can be an epoxy resin obtained by reacting (meth)acrylic acid with a lower molecular weight bisphenol epoxy resin or a novolak epoxy resin. An oxirane ring is a compound obtained by an esterification reaction.

For example, the polyol acrylate-based compound can be a compound obtained by esterification reaction of a hydroxyl group of a polyether polyol with (meth)acrylic acid.

Further, the active energy ray-curable compound preferably has a mass average molecular weight of 950 or less, and preferably has a mass average molecular weight of 300 to 700. Thereby, the composition for forming a smoothing layer before being applied to the first surface 111 of the substrate 11 and irradiated with the active energy ray can have an appropriate viscosity. Thereby, the smoothing layer forming composition has more appropriate fluidity. By using such a composition for forming a smoothing layer, the smoothing layer 12 is formed at the position of the first surface 111 of the substrate 11, and the uneven state of the first surface 111 of the substrate 11 can be more reliably filled. As a result, it is possible to more reliably prevent the uneven state of the substrate 11 from affecting the third surface 121 of the smoothing layer 12, and to make the third surface 121 of the smoothing layer 12 smoother. Therefore, in particular, it is possible to prevent the uneven state of the substrate 11 from affecting the outer surface 131 of the release agent layer 13 formed on the smoothing layer 12, and to make the outer surface 131 of the release agent layer 13 smoother.

In particular, even when the surface of the first surface 111 of the substrate 11 has a large unevenness state, it is possible to appropriately fill the uneven state of the first surface 111 by the action and effect of the smoothing layer forming composition. It is also possible to obtain the release film 1 which is particularly excellent in the smoothness of the outer surface 131 of the release agent layer 13.

On the other hand, if the mass average molecular weight of the active energy ray-curable compound does not reach the above lower limit, the viscosity of the composition for forming a smoothing layer is low, and the time for hardening the smoothing layer 12 may become longer. The occasion. In addition, when the mass average molecular weight of the active energy ray-curable compound exceeds the above upper limit, the viscosity of the composition for forming a smoothing layer becomes higher depending on factors such as the type of the active energy ray-curable compound. In order to adjust the viscosity, it may happen that a viscosity adjuster or the like must be added.

Further, the composition for forming a smoothing layer may contain a solvent as needed in addition to the active energy ray-curable compound. Thereby, the viscosity of the composition for forming a smoothing layer applied to the first surface 111 of the substrate 11 can be easily adjusted.

For example, the solvent can be a fatty acid ester such as aromatic hydrocarbons such as toluene or xylene, ethyl acetate, and butyl acetate. Acid esters), methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK), ketones, methanol, ethanol and isopropyl One or a combination of two or more organic solvents such as an alcohol such as isopropyl alcohol. borrow Thus, the composition for forming a smoothing layer before being applied to the first surface 111 of the substrate 11 and irradiated with the active energy ray is likely to have an appropriate viscosity.

Further, the composition for forming a smoothing layer may contain other components in addition to the above components. Other components may be a crosslinking agent, a photopolymerization initiator, a viscosity modifier, a catalyst, a dye, a dispersant, an antistatic agent, a hardener, and the like. Further, in the case where the other components are contained, the content of the other components is preferably 0.1 to 10% by mass in the composition for forming a smoothing layer (calculated as a solid content).

Further, among the compositions for forming a smoothing layer containing a solvent, the content of the active energy ray-curable compound is not particularly limited, but is preferably 0.5 to 60% by mass, and is 1 to 45% by mass. Preferably. Thereby, the composition for forming a smoothing layer tends to have an appropriate viscosity.

Further, among the components for forming a smoothing layer (calculated as a solid content), the content of the active energy ray-curable compound is not particularly limited, but it is preferably 90% or more, and more preferably 95 or more. The percentage is preferred. Thereby, the composition for forming a smoothing layer can have particularly excellent hardenability.

Further, the arithmetic mean roughness Ra ₄ of the third surface 121 of the smoothing layer 12 is preferably 8 nm or less, and the maximum protrusion height Rp ₄ is preferably 50 nm or less. Furthermore, the arithmetic mean roughness Ra _{4 of the} third surface 121 is preferably 6 nm or less. Further, the maximum protrusion height Rp _{4 of the} third surface 121 is preferably 40 nm or less.

When the arithmetic mean roughness Ra ₄ and the maximum protrusion height Rp _{4 of the} third surface 121 fall within the above range, it is possible to more reliably prevent the surface unevenness state of the substrate 11 from affecting the outer surface 131 of the release agent layer 13.

On the other hand, when the arithmetic mean roughness Ra _{4 of the} third surface 121 exceeds the above upper limit value, a new smoothing layer needs to be further provided between the release agent layer 13 and the smoothing layer 12.

On the other hand, if the maximum protrusion height Rp _{4 of the} third surface 121 exceeds the above upper limit value, a situation in which a new smoothing layer needs to be further provided between the release agent layer 13 and the smoothing layer 12 occurs.

Further, although the average film thickness of the smoothing layer 12 is not particularly limited, it is preferably 0.2 to 10 μm, more preferably 0.3 to 5 μm. Thereby, the unevenness of the first surface 111 of the substrate 11 can be more reliably filled, and the smoothness of the outer surface of the release film 1 can be further improved. In particular, since the composition for forming a smoothing layer of the present embodiment is formed by containing the active energy ray-curable compound as described above, even if the film thickness of the smoothing layer 12 is relatively thin, it is possible to more easily and reliably fill the substrate. The uneven state of the first surface 111 of 11. Moreover, the smoothing layer 12 can have moderate flexibility.

On the other hand, when the average film thickness of the smoothing layer 12 is less than the above-described lower limit, the component constituting the smoothing layer forming composition is sufficiently filled in the uneven state of the first surface 111 of the substrate 11 in order to sufficiently fill the composition of the smoothing layer forming composition. There is a case where it is necessary to use the substrate 11 having a small surface roughness of the first surface 111. In addition, when the average thickness of the smoothing layer 12 exceeds the above-described upper limit, it is easy to cause warpage of the release film 1 due to curing and shrinkage of the smoothing layer 12 depending on the composition of the composition for forming the smoothing layer. The operability of the release film 1 is lowered.

The release agent layer 13 will be described below.

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

The release agent layer 13 is provided at the position of the third surface 121 of the smoothing layer 12 as shown in FIG.

The release agent layer 13 is formed by drying and hardening the composition for forming a release agent layer applied to the third surface 121 of the smoothing layer 12.

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

As the release agent, one of an alkyd compound, an acryl compound, a silicone compound, a long-chain alkyl group-containing compound, a fluoride, or the like can be used. Or combine two or more release agents. Among them, an alkyd compound, a propylene oxime compound, an fluorenone compound, or a compound containing a long-chain alkyl group is preferably used. Thereby, it is possible to obtain the release agent layer 13 which is particularly excellent in the release property from the green sheet while having moderate hardenability.

Specifically, as the alkyd compound, a denatured product such as a long-chain alkyl-modified alkyd compound or an anthrone-modified alkyd compound can be used. Further, when an alkyd compound is used, a crosslinking agent and a catalyst may be additionally added to the composition for forming a release agent layer. The release agent layer 13 having an alkyd compound having a crosslinked structure can be obtained by a method of heat-hardening the composition for forming a release agent layer. As a result, when the green sheet is formed on the release agent 13, the migration of the alkyd compound having the release property to the green sheet can be prevented, and the release agent layer 13 can be prevented. The shape loss is reduced.

Further, as a specific example, the propylene oxime compound can be a denatured product such as a long-chain alkyl acryl ruthenium compound or an fluorenone propylene oxime compound. Further, when the acrylonitrile-based compound is contained in the composition for forming a release agent layer, a crosslinking agent and a catalyst can be additionally added to the composition for forming a release agent layer. The release agent layer 13 having a propylene-based compound having a crosslinked structure can be obtained by a method of heat-hardening the composition for forming a release agent layer. As a result, it is possible to prevent the propylene-based compound having the release property from moving to the smoothing layer 12, and it is possible to prevent the release property of the release agent layer 13 from being lowered.

In addition, as an anthrone-based compound, for example, an anthrone-based compound containing dimethylpolysiloxane as a basic skeleton can be used. The anthrone-based compound has an addition reaction type, a condensation reaction type, an ultraviolet curing type, and an electron beam curing type. The addition reaction type fluorenone compound can optimize productivity due to high reactivity. Compared with the oxime ketone compound of the condensation reaction type, the oxime ketone compound of the addition reaction type is advantageously used for constituting the release agent layer because it has a small change in the release force after production and no hardening and shrinkage. 13 release agent.

Specifically, the above-described addition reaction type fluorenone compound can be an organopolysiloxane which is attached to a molecular terminal and/or a side chain of the compound such as vinyl or ally. Two or more alkenyl groups of alkenyl having 2 to 10 carbon atoms, such as allyl, propenyl or hexenyl. Using such an additive reaction type In the case of the fluorenone compound, a crosslinking agent and a catalyst can also be used in combination.

The above cross-linking agent is, for example, an organopolyoxyalkylene having a hydrogen atom bonded to at least two deuterium atoms in one molecule, specifically, for example, dimethyl hydrogen siloxy-terminated Dimethyl siloxane-methyl hydrogen siloxane copolymer, trimethyl siloxy-terminated dimethyl methoxy-methane hydroquinone An alkane copolymer, a trimethyl siloxy-terminated methyl hydrogen polysiloxane, or a poly(hydrogen silsesquioxane).

Further, the catalyst may be particulate platinum, particulate platinum adsorbed on a carbon powder carrier, chloroplatinic acid, alcohol-modified chloroplatinic acid, olefinic complex of chloroplatinic acid, palladium, ruthenium. A platinum compound such as (rhodium). By using such a catalyst, the hardening reaction of the composition for forming a release agent layer can be performed more efficiently.

Further, for example, the long-chain alkyl group-containing compound is obtained by, for example, using a long-chain alkyl isocyanate having a carbon number of 8 to 30 in a polyvinyl alcohol-based polymer. A vinyl carbamate and a urea urea derivative obtained by reacting a long-chain alkyl isocyanate having 8 to 30 carbon atoms in polyethyleneimine.

Further, as a specific example, a compound such as a fluorine silicone compound or a boron compound can be used as the fluoride.

Further, the release agent layer-forming composition may contain a dispersant and a solvent in addition to the above-mentioned release agent. By containing at least one of a dispersing agent and a solvent, the composition for forming a release agent layer applied to the third surface 121 of the smoothing layer 12 and dried can have an appropriate viscosity.

For example, an aromatic hydrocarbon such as toluene, a fatty acid ester such as ethyl acetate, a ketone such as methyl ethyl ketone, or an organic solvent such as an aliphatic hydrocarbon such as hexane or heptane can be used as the dispersant or the solvent. One of them or a combination of two or more.

Further, the composition for forming a release agent layer may contain other components in addition to the above components. Other ingredients may be, for example, catalysts, dyes, dispersants, antistatic agents, hardeners, and the like. Further, in the case where the other components are contained, the content of the other components in the composition for forming a release agent layer is preferably 0.1 to 10% by mass.

Further, among the compositions for forming a release agent layer, the content of the release agent is not particularly limited, but is preferably 0.3 to 10% by mass.

Further, as described above, the arithmetic mean roughness Ra ₁ of the outer surface 131 of the release agent layer 13 is 8 nm or less, and the maximum protrusion height Rp ₁ is 50 nm or less. Furthermore, the arithmetic average roughness Ra _{1 of the} outer surface 131 of the release agent layer 13 is preferably 6 nm or less. Further, the maximum protrusion height Rp _{1 of the} outer surface 131 of the release agent layer 13 is preferably 40 nm or less.

The arithmetic mean roughness Ra ₁ and the maximum protrusion height Rp _{1 of the} outer surface 131 of the release agent layer 13 fall within the foregoing range, and are transferred to the green body by the smooth surface shape of the outer surface 131 when the green sheet is formed. The sheet can more appropriately prevent the occurrence of pinholes or the like on the surface of the green sheet. As a result, a green sheet having a smoother surface can be obtained.

Further, the average thickness of the release agent layer 13 is preferably 0.01 to 3 μm, more preferably 0.03 to 1 μm. If the thickness of the release agent layer 13 is less than 0.01 μm, depending on the material constituting the release agent layer 13, there is a case where the function of the release agent layer cannot be sufficiently exhibited. On the other hand, when the thickness of the release agent layer 13 exceeds 3 μm, when the release film 1 is wound into a roll shape, agglomeration may occur easily, and the release film 1 may be wound poorly, or may be caused. When the release film 1 is unwound, problems such as high static electricity occur.

Hereinafter, a method of producing a release film for producing a green sheet will be described.

Next, a description will be given of a suitable embodiment regarding the manufacturing method of the release film 1 for producing a green sheet as described above.

The manufacturing method of the release film 1 of the present embodiment includes a substrate preparation process, a coating layer forming process, a smoothing layer forming process, and a release agent layer forming process. The substrate preparation process prepares the substrate 11. The coating layer forming process applies a composition for forming a smoothing layer containing a specified active energy ray-curable compound to the first surface 111 of the substrate 11, and then drying it as needed to form a coating layer. The smoothing layer forming process forms the smoothing layer 12 by irradiating and hardening the coating layer with an active energy ray. The release agent layer forming process is performed at a position opposite to the surface 121 of the aforementioned substrate 11 of the smoothing layer 12 to form a release agent layer 13.

Hereinafter, each process will be described in detail.

The substrate preparation process will be described below.

First, the substrate 11 is prepared.

The substrate 11 can use the substrate 11 as described above.

Next, a surface treatment such as an oxidation method or a primer treatment can be performed on the first surface 111 of the substrate 11. Thereby, the adhesion between the substrate 11 and the smoothing layer 12 provided at the position of the first surface 111 of the substrate 11 can be particularly optimized.

The surface treatment such as the oxidation method can be appropriately selected depending on the kind of the substrate 11 . For example, it may be a corona discharge treatment, a plasma discharge treatment, a chrome oxidation treatment (wet), a flame treatment, a hot air treatment, an ozone treatment, an ultraviolet irradiation treatment, or the like. Among them, from the viewpoint of optimizing the adhesion between the smoothing layer 12 and the operation of simplifying the processing, it is preferable to use a corona discharge treatment method in particular.

The coating layer forming process will be described below.

In the present process, a composition for forming a smoothing layer is first prepared.

The composition for forming a smoothing layer can be used alone as the above-described active energy ray-curable compound. In addition to this, it is also possible to use a composition for forming a smoothing layer in which a solvent or other component as described above is mixed as needed.

Next, a liquid-like composition for forming a smoothing layer is applied onto the first surface 111 of the substrate 11. Thereby, a coating layer was obtained. As described above, since the composition for forming a smoothing layer has moderate fluidity, the smoothing layer forming composition can be applied to the first surface 111 of the substrate 11 to be surely filled in the substrate 11 The uneven state of a surface 111. As a result, the substrate 11 can be prevented The uneven state affects the third surface 121 of the smoothing layer 12, and the third surface 121 of the smoothing layer 12 can be made smooth.

In addition, when the composition for forming a smoothing layer contains a solvent, a composition for forming a smoothing layer is applied onto the first surface 111 of the substrate 1, and then a coating layer is obtained by drying the composition for forming a smoothing layer. . Therefore, the solvent can be removed by drying the composition for smoothing layer formation.

A method of applying a composition for forming a smoothing layer, for example, a gravure coat method, a bar coat method, a spray coat method, a spin coat method, and an air knife coating (air) A knife coat method, a roll coat method, a blade coat method, a gate roll coat method, and a die coat method. Among them, a gravure coating method and a bar coating method are preferable, and a bar coating method is more preferable. Thereby, the coating layer of the target thickness can be easily formed.

In the case where the smoothing layer forming composition contains a solvent, the method of drying the smoothing layer forming composition is not particularly limited, and may be, for example, a drying method using a hot air drying furnace or the like.

Further, the drying conditions in the case where the composition for forming a smoothing layer is dried are not particularly limited. The drying temperature is preferably from 50 to 100 degrees Celsius, and the drying time is preferably from 5 seconds to 1 minute. Thereby, it is possible to prevent the smoothing layer 12 from being unintentionally deteriorated, and at the same time, the smoothing layer 12 can be formed particularly efficiently. As a result, the productivity of the finally obtained release film 1 can be improved. In addition, when the drying temperature falls within the above range, when the composition for forming a smoothing layer contains a solvent, warpage of the smoothing layer 12 can be particularly prevented as the solvent evaporates during drying. crack.

The smoothing layer forming process will be described below.

Next, the smoothing layer 12 is formed by irradiating and hardening the coating layer obtained by the coating layer forming process with active energy rays.

In the present process, the coating layer in the uneven state of the first surface 111 of the substrate 11 is surely filled by the coating layer forming process so as to maintain the smoothness of the outer surface. As a result, the smoothing layer 12 in which the third surface 121 is very smooth can be obtained. Thereby, it is possible to more appropriately prevent the uneven state of the first surface 111 of the substrate 11 from affecting the outer surface 131 of the release agent layer 13. Therefore, the smoothness of the outer surface 131 of the release agent layer 13 can be optimized in the process of forming the release agent layer described later.

For example, the active energy ray to be hardened may be appropriately selected depending on the material contained in the composition for forming a smoothing layer to be used, but may be visible light, ultraviolet light, infrared light, X-ray, alpha ray, or beta ray. , gamma rays and electron beams. Among them, ultraviolet light or visible light is preferred.

For example, although the wavelength of the active energy ray (ultraviolet light or visible light) is not particularly limited, it is preferably 200 to 600 nm in wavelength and 250 to 450 nm in wavelength. When the wavelength of the active energy ray falls within the above range, the hardening time of the hard coat layer can be sufficiently shortened, and the coating layer can be uniformly cured.

Further, the mechanism for irradiating the active energy ray (ultraviolet light or visible light) is not particularly limited, and various general mechanisms can be utilized. For example, high-pressure mercury lamps, metal halide lamps, and excimers can be used. A light source such as a lamp is used as a light source.

Furthermore, in the case of irradiating an active energy ray (ultraviolet or visible light), the amount of active energy ray irradiation is preferably 50 to 400 mJ/cm ² , and 100 to 300 mJ/cm ^{2 .} good. When the irradiation amount of the active energy ray falls within the above range, the coating layer can be more uniformly and surely cured.

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

The release agent layer forming process will be described below.

Next, a release agent layer 13 is formed at a position opposite to the surface 121 of the substrate 11 of the smoothing layer 12.

It is prepared to mix a material as described above as a composition for forming a release agent layer constituting the release agent layer 13.

Next, after the composition for forming a liquid release agent layer is applied to the surface 121 of the smoothing layer 12 opposite to the substrate 11, it is dried and hardened. Thereby, the release agent layer 13 is obtained.

Although the drying method is not particularly limited, it may be, for example, a drying method using a hot air drying furnace or the like.

Further, the drying conditions are not particularly limited. The drying temperature is preferably 80 to 150 degrees Celsius, and the drying time is preferably 5 seconds to 1 minute. Thereby, it is possible to prevent the release agent layer 13 from being unintentionally deteriorated, and at the same time, the release agent layer 13 can be formed particularly efficiently. As a result, the resulting release film 1 can be improved. Productivity.

According to the above process, the release film 1 which is excellent in smoothness, excellent in release property, and high in reliability can be easily produced.

Further, by using the release film 1 to produce a green sheet, it is possible to prevent pinholes or the like from occurring on the surface of the green sheet.

Further, the method of producing a ceramic green sheet using the release film 1 can be, for example, a method comprising applying a ceramic powder dispersion slurry to the surface of the release agent layer of the release film and drying it to form a green sheet. The green sheets peeled off from the release film are stacked to obtain a stacked body, and the ceramic sheets obtained by sintering the stacked body form electrodes. Thereby, a ceramic capacitor can be obtained. Therefore, by forming a ceramic capacitor using the green sheet formed by the release film 1, it is possible to prevent a ceramic capacitor having high reliability due to a problem of malfunction due to a short circuit.

The above detailed description of the preferred embodiments of the invention is not intended to limit the invention.

For example, in the above-described embodiment, the substrate has a single layer structure, but the invention is not limited thereto. The substrate can also have a multilayer structure of two or more layers of the same or different species. Further, the smoothing layer and the release agent layer are similarly described as having a single layer structure, but are not limited thereto. The smoothing layer and the release agent layer can also each have a multilayer structure of two or more layers of the same or different species.

Further, for example, in the above-described embodiment, a release film for producing a green sheet in which a smoothing layer is provided on a first surface of a substrate will be described. Of course Further, the release film for producing a green sheet is not limited thereto, and the smoothing layer and the release agent layer may be provided at a position on the second surface of the substrate.

In the above-described embodiment, the base material, the smoothing layer, and the release agent layer which are bonded to each other in the form of a release film for green sheet production are stacked and formed into a three-layer structure. It is not limited to this. An intermediate layer may also be disposed between the smoothing layer and the release agent layer. Further, an intermediate layer may be provided between the substrate and the smoothing layer. Such an intermediate layer can improve the adhesion between the smoothing layer and the release agent layer, and can also be a layer body capable of suppressing the occurrence of static electricity when the release film for the green sheet before the formation of the green sheet is wound.

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

The embodiment will be described below.

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

The production of a release film for producing a green sheet will be described below.

Embodiment 1 will be explained below.

First, a biaxially stretched polyethylene terephthalate film as a substrate (thickness: 38 μm, arithmetic mean roughness Ra _{2 of the} first surface: 42 nm, maximum protrusion height Rp _{2 of the} first surface: 619 nm) The arithmetic mean roughness Ra _{3 of the} second surface is 42 nm, and the maximum protrusion height Rp _{3 of the} second surface is 619 nm].

Next, a composition for forming a smoothing layer having a solid content of 20% by mass, which is mixed with 100 parts by mass as an active energy ray hard An ultraviolet curable compound containing a urethane acrylate oligomer as a main component of the chemical compound (product name "BEAMSET 575CB", manufactured by Arakawa Chemical Industry Co., Ltd., a solid content of 100% by mass, and a mass average molecular weight of 470, containing a photopolymerization initiator], toluene and methyl ethyl ketone.

The resulting composition for forming a smoothing layer was applied to the first surface of the substrate with a No. 4 wire bar (Meyer bar #4), and dried continuously at 80 ° C for 1 minute to obtain a coating layer.

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

Then, a mixture of 100 parts by mass was diluted with toluene to obtain a diluted solution, and the mixture (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "SILICONE KS-847H", and a solid content of 30% by mass) was mixed. An addition reaction type anthrone compound and a crosslinking agent. To the diluted solution, two parts by mass of a platinum catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "PL-50T") was added and mixed to obtain a composition for forming a release agent layer having a solid content of 1.5% by mass. Things. The composition for forming a release agent layer was uniformly coated on the surface of the smoothing layer opposite to the surface of the substrate so that the thickness of the composition for forming the release agent layer was 0.1 μm. Thereafter, the release agent layer was formed by drying the composition for forming a release agent layer at 130 ° C for 1 minute to produce a release film for producing a green sheet.

Embodiment 2 will be described below.

In addition to changing the biaxially stretched polyethylene terephthalate film of Example 1 to a biaxially stretched polyethylene terephthalate film [thickness: 31 μm, the arithmetic mean roughness Ra _{2 of the} first surface: 29 nm, the maximum protrusion height Rp _{2 of the} first surface: 257 nm, the arithmetic mean roughness Ra _{3 of the} second surface: 29 nm, and the maximum protrusion height Rp _{3 of the} second surface: 257 nm are the same as in the first embodiment. A method is used to manufacture a release film for the production of a green sheet.

Embodiment 3 will be explained below.

In addition to changing the biaxially stretched polyethylene terephthalate film of Example 1 to a biaxially stretched polyethylene terephthalate film [thickness: 31 μm, the arithmetic mean roughness Ra _{2 of the} first surface: 15 nm, the maximum protrusion height Rp _{2 of the} first surface is: 98 nm, the arithmetic mean roughness Ra _{3 of the} second surface is 15 nm, the maximum protrusion height of the second surface is Rp ₃ : 98 nm, and the thickness of the smoothing layer is changed to 0.4 μm. A release film for producing a green sheet was produced in the same manner as in Example 1 except that the rest was carried out.

Embodiment 4 will be explained below.

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 1.8 μm.

Embodiment 5 will be explained below.

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 μm.

Comparative Example 1 will be described below.

First, a biaxially stretched polyethylene terephthalate film as a substrate (thickness: 38 μm, arithmetic mean roughness Ra _{2 of the} first surface: 42 nm, maximum protrusion height Rp _{2 of the} first surface: 619 nm) The arithmetic mean roughness Ra _{3 of the} second surface is 42 nm, and the maximum protrusion height Rp _{3 of the} second surface is 619 nm].

Then, a mixture of 100 parts by mass was diluted with toluene to obtain a diluted solution, and the mixture (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "SILICONE KS-847H", and a solid content of 30% by mass) was mixed as a release. Addition reaction type anthrone compound and crosslinking agent. To the diluted solution, two parts by mass of a platinum catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "PL-50T") was added and mixed to obtain a composition for forming a release agent layer having a solid content of 1.5% by mass. Things. The release agent layer-forming composition was uniformly coated on the first surface of the substrate so that the thickness of the release agent layer-forming composition after drying was 0.1 μm. Thereafter, the release agent layer was formed by drying the composition for forming a release agent layer at 130 ° C for 1 minute to produce a release film for producing a green sheet.

Comparative Example 2 will be described below.

First, a biaxially stretched polyethylene terephthalate film as a substrate (thickness: 38 μm, arithmetic mean roughness Ra _{2 of the} first surface: 42 nm, maximum protrusion height Rp _{2 of the} first surface: 619 nm) The arithmetic mean roughness Ra _{3 of the} second surface is 42 nm, and the maximum protrusion height Rp _{3 of the} second surface is 619 nm].

Next, a composition for forming a smoothing layer having a solid content of 20% by mass is obtained, which is mixed with 100 parts by mass of a stearyl denatured alkyd compound and a methyl group as a thermosetting compound. a mixture of melamine compounds [Hitachi Chemicals Co., Ltd., The product name is "TESFINE 303", a solid content of 20% by mass, a mass average molecular weight of 15000] and 3 parts by mass of an acid catalyst of p-toluenesulfonic acid, toluene and methyl ethyl ketone. The obtained composition for forming a smoothing layer was applied to the first surface of the substrate with a No. 4 wire bar to obtain a coating layer.

Next, a smoothing layer (thickness 1.0 μm) was formed by continuously drying and heating the coating layer at 140 ° C for 1 minute.

Then, a mixture of 100 parts by mass was diluted with toluene to obtain a diluted solution, and the mixture (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "SILICONE KS-847H", and a solid content of 30% by mass) was mixed. An addition reaction type anthrone compound and a crosslinking agent. To the diluted solution, two parts by mass of a platinum catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "PL-50T") was added and mixed to obtain a composition for forming a release agent layer having a solid content of 1.5% by mass. Things. The composition for forming a release agent layer was uniformly coated on the surface of the smoothing layer opposite to the surface of the substrate so that the thickness of the composition for forming the release agent layer was 0.1 μm. Thereafter, the release agent layer was formed by drying the composition for forming a release agent layer at 130 ° C for 1 minute to produce a release film for producing a green sheet.

Comparative Example 3 will be described below.

In addition to obtaining a composition for forming a smoothing layer having a solid content of 20% by mass, 40 parts by mass of a cationically polymerizable violet containing an epoxy-modified anthrone compound as an active energy ray-curable compound as a main component is mixed. Externally curable compound [UVPOLY 200, manufactured by Arakawa Chemical Co., Ltd., a solid content concentration of 100% by mass, a mass average molecular weight of 20,000], and 3 parts by mass of a boron-based cationic hardening ultraviolet catalyst as a catalyst [Arakawa Chemical Co., Ltd. A release film for producing a green sheet was produced in the same manner as in Example 1 except that "UVCATA 211" manufactured by Industrial Co., Ltd., having a solid content of 20% by weight, toluene and methyl ethyl ketone.

Comparative Example 4 will be described below.

First, a biaxially stretched polyethylene terephthalate film as a substrate (thickness: 38 μm, arithmetic mean roughness Ra _{2 of the} first surface: 42 nm, maximum protrusion height Rp _{2 of the} first surface: 619 nm) The arithmetic mean roughness Ra _{3 of the} second surface is 42 nm, and the maximum protrusion height Rp _{3 of the} second surface is 619 nm].

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

The obtained composition for forming a smoothing layer was applied to the first surface of the substrate with a No. 4 wire bar to obtain a coating layer.

Next, a smoothing layer (thickness 1.2 μm) was formed by continuously drying and heating the coating layer at 130 ° C for 1 minute.

Then, a mixture of 100 parts by mass of toluene is diluted to obtain Diluate, this mixture (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "SILICONE KS-847H", solid content of 30% by mass] mixed with an addition-type anthrone-based compound as a release agent and cross-linking Agent. To the diluted solution, two parts by mass of a platinum catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "PL-50T") was added and mixed to obtain a composition for forming a release agent layer having a solid content of 1.5% by mass. Things. The composition for forming a release agent layer was uniformly coated on the surface of the smoothing layer opposite to the surface of the substrate so that the thickness of the composition for forming the release agent layer was 0.1 μm. Thereafter, the release agent layer was formed by drying the composition for forming a release agent layer at 130 ° C for 1 minute to produce a release film for producing a green sheet.

Comparative Example 5 will be described below.

In addition to obtaining a composition for forming a smoothing layer having a solid content of 20% by mass, which is diluted with toluene as an active energy ray-curable compound, an ultraviolet curing compound containing acrylate oligomer as a main component [Dacheng Precision Chemicals ( A fine film for producing a green sheet was produced in the same manner as in Example 1 except that the solid content was 40% by mass and the mass average molecular weight was 25,000.

Tables 1-1 to 1-3 show the constitution of the release film for producing a green sheet of each comparative example.

Further, in the table, an ultraviolet curable compound containing a urethane acrylate oligomer as an active energy ray-curable compound (manufactured by Arakawa Chemical Industries Co., Ltd., trade name "BEAMSET 575CB", solid content It is a mass percentage of 100, and the mass average molecular weight is 470], which is expressed as "A1", and is a hard curable compound of a hard curable compound and a methylated melamine compound. A mixture of the products (trade name "TESFINE 303" manufactured by Hitachi Chemical Co., Ltd., a solid content of 20% by mass, and a mass average molecular weight of 15,000) is expressed as "A2" as an active energy ray-curable compound. A cationically polymerizable ultraviolet curable compound (UVPOLY 200, manufactured by Arakawa Chemical Industries Co., Ltd., a solid content concentration of 100% by mass, and a mass average molecular weight of 20,000) is represented by "A3". As a thermosetting compound, a polyester compound (manufactured by Toyobo Co., Ltd., trade name "VYLON 20SS", a solid content of 30% by mass, and a mass average molecular weight of 3000) is expressed as "A4" as an active energy. An ultraviolet curable compound containing an acrylate oligomer as a main component of the ray-curing compound [8KX-012C, manufactured by Daisei Kogyo Co., Ltd.), a solid content concentration of 40% by mass, and a mass average molecular weight of 25,000. ] is indicated as "A5".

In addition, the film thickness of each of the base material, the smoothing layer, and the release agent layer of each of the examples and the comparative examples was measured by a reflection type film thickness meter "F20" (manufactured by FILMETRICS Co., Ltd.).

Further, the arithmetic mean roughness Ra ₂ and the maximum protrusion height Rp ₂ of the first surface of the substrate, the arithmetic mean roughness Ra ₃ and the maximum protrusion height Rp ₃ of the second surface of the substrate, and smoothing are each measured in the following manner. The arithmetic mean roughness Ra ₄ and the maximum protrusion height Rp ₄ of the third surface of the layer, the arithmetic mean roughness Ra _{1 of the} outer surface of the release agent layer, and the maximum protrusion height Rp ₁ . First, attach double-sided tape to the glass. Next, the release film for producing a green sheet obtained by each of the examples and the comparative examples is fixed to the glass plate so that the opposite surface of the positional surface of the arithmetic mean roughness and the maximum protrusion height to be measured is oriented to the glass sheet. On double-sided tape. In this way, the arithmetic mean roughness Ra ₂ , Ra ₃ , Ra ₄ , Ra ₁ and the maximum amount described above were measured in accordance with Japanese Industrial Standard JIS B0601-1994 using a surface roughness measuring machine SV3000S4 (stylus type) manufactured by Mitutoyo Corporation. Protrusion heights Rp ₂ , Rp ₃ , Rp ₄ , Rp ₁ .

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

The evaluation of the release film for producing a green sheet obtained as described above was carried out.

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

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

A: The appearance of the release film roll before storage was obtained by winding the release film of the green sheet into a roll shape, and the appearance of the release film roll after storage was not changed (no agglomeration phenomenon).

B: A region having a local color tone change in the release film roll for green sheet production (the tendency to agglomerate but still usable).

C: In the release film roll for producing a green sheet, the color tone of a wide area is changed (the phenomenon of agglomeration).

As in the above-mentioned reference C, the surface and the back surface of the release film for green sheet production are adhered to each other to cause agglomeration, which is in a large area of the release film cylinder. In the case where the color tone changes, it is not possible to normally roll the release film for the green sheet.

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

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

A: The number of recesses is zero.

B: The number of recesses is 1 to 5.

C: The number of recesses is six or more.

The results are shown in Table 2.

As is apparent from Table 2, the release film for producing a green sheet of the present invention has excellent smoothness on the outer surface. Further, the green sheet formed by using the release film of the green sheet of the present invention produced almost no large concave portion. Further, by manufacturing a ceramic capacitor using the green sheet formed by using the green sheet of the present invention to produce a release film, no occurrence of a failure such as a short circuit was observed. On the contrary, the comparative example did not give satisfactory results.

1‧‧‧Folding film for green sheet manufacturing

11‧‧‧Substrate

111‧‧‧The first surface of the substrate

112‧‧‧Second surface of the substrate

12‧‧‧Smoothing layer

121‧‧‧ surface (third surface)

13‧‧‧ release agent layer

131‧‧‧Outer surface of the release agent layer

Claims (7)

A release film for manufacturing a green sheet, comprising: a substrate having a first surface and a second surface, wherein the first surface has an arithmetic average roughness Ra ₂ of 10 to 200 nm, and the One of the first surfaces has a maximum protrusion height Rp ₂ of 80 to 1000 nm; a smoothing layer is disposed on the first surface of the substrate; and a release agent layer disposed on the substrate opposite to the substrate a surface position; wherein the smoothing layer is formed by irradiating and hardening an active energy ray with a composition for forming a smoothing layer containing an active energy ray-curable compound; One of the outer surfaces of the release agent layer has an arithmetic mean roughness Ra ₁ of 8 nm or less, and one of the outer surfaces of the release agent layer has a maximum protrusion height Rp ₁ of 50 nm or less. The release film for producing a green sheet according to claim 1, wherein the active energy ray-curable compound is a compound having a mass average molecular weight of 950 or less. The release film for producing a green sheet according to claim 1, wherein the active energy ray-curable compound is an ultraviolet curable compound, and the active energy ray is ultraviolet ray. The release film for producing a green sheet according to claim 1, wherein one of the smoothing layers has an average film thickness of 0.2 to 10 μm. The release film for producing a green sheet according to claim 1, wherein the smoothing layer has a surface roughness opposite to a surface of the substrate, and the smoothing layer is opposite to an average roughness of the surface of the substrate. Ra ₄ is 8 nm or less, and the maximum protrusion height Rp ₄ of the surface of the smoothing layer opposite to the surface of the substrate is 50 nm or less. The release film for producing a green sheet according to claim 1, wherein an arithmetic mean roughness Ra ₃ of the second surface is 10 to 200 nm, and a maximum protrusion height Rp ₃ of the second surface is 80 to 1000 nm. . A method for producing a release film for producing a green sheet according to any one of claims 1 to 6, comprising the following process: a substrate preparation process for preparing the substrate, the substrate having the first surface And the second surface; a coating layer forming process, wherein the coating layer is formed by applying the smoothing layer forming composition containing the active energy ray-curable compound to the first surface position of the substrate; a smoothing layer forming process for forming the smoothing layer by irradiating and hardening the coating layer with the active energy ray; and a release agent layer forming process, wherein the smoothing layer is opposite to the substrate The surface position forms the release agent layer; wherein the arithmetic mean 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 It is 50 nm or less.