KR20120045213A - Carrier film for green sheet - Google Patents

Abstract

PURPOSE: A carrier film for molding green sheet is provided to have excellent antistatic property, to have low surface roughness, and to be able to improve delamination failure between a green sheet and a carrier because of excellent peering ability of a silicon release layer. CONSTITUTION: A carrier film for molding green sheet comprises a silicone release layer on at least one side of a polyester substrate sheet layer, in which an antistatic coating layer is in-lined coated. The silicon release layer satisfies formula 1: RF <= 10, and formula 2: N_0.5 < 1. In formulas, RF is peering force to a green sheet(gf/inch), and N_0.5 is number of protrusions with height of 0.5 micron or higher on area of 1mm^2 to the silicon release layer. The carrier film has antistatic resistance of 10^12 Ω/□ or less.

Description

Carrier film for green sheet molding {CARRIER FILM FOR GREEN SHEET}

The present invention relates to a carrier film for forming a green sheet, and more particularly, by including a silicone release layer on at least one surface of a polyester base sheet layer provided with an antistatic coating layer in one step, excellent antistatic properties are inherent, The present invention relates to a carrier film for forming a green sheet, in which peeling defects generated during peeling of the green sheet and the carrier film are improved due to the excellent peeling property of the silicone release layer.

In general, multilayer ceramic capacitors (MLCC) are general-purpose core components commonly used in electronic products such as mobile phones and LCD TVs, and play a role in flowing current required by the corresponding products. The green sheet used in the multilayer ceramic capacitor uses a carrier film during processing. The carrier film is generally in a form in which a silicone release film is formed on a polyester base sheet.

With the recent trend toward miniaturization and thinning of electronic products, ceramic multilayer capacitors also have to be miniaturized and large in capacity, and in order to meet such demands, thinning of green sheets is also required.

Therefore, in order to reduce the thickness of the green sheet, the solid content and viscosity of the ceramic slurry should be lowered, and should be thinly coated on the molding carrier film.

However, in the case of thin-coated thin green sheet as described above, the green sheet and the carrier film are torn off when the green sheet is peeled off from the carrier film. Poor phenomena occur frequently.

Accordingly, the present inventors have tried to solve the problems caused by the thinning of the conventional green sheet, and as a result, the surface roughness of the carrier film is low, and in particular, the surface is designed to be uniform without coarse protrusions, so that the peeling stability during peeling of the green sheet and the carrier film is improved. By providing a carrier film that can be realized, the present invention has been completed.

An object of the present invention is to provide a carrier film for forming a green sheet comprising a silicone release layer on at least one surface of the polyester base sheet layer provided with an antistatic coating layer in one step.

The present invention comprises a silicon release layer on at least one surface of the polyester substrate sheet layer in-line coated with an antistatic coating layer, wherein the silicon release layer is a carrier film for forming a green sheet that satisfies the following equations (1) and (2) to provide.

Equation 1

RF ≤ 10

Equation 2

N_0.5 <1

(In the above, RF is the peel force (g _f / inch) of the silicon release layer with respect to the green sheet, N_0.5 is the number of protrusions of 0.5㎛ or more in the area of 1mm 2 with respect to the silicon release layer.)

The carrier film for green sheet molding of this invention is characterized by having the outstanding antistatic property of surface resistance 10 <^12> Pa / square or less.

In the carrier sheet for forming a green sheet, the polyester base sheet layer is formed in a laminated structure of two or more layers by coextrusion, and a polyester layer containing 0.1 to 3 μm particles is formed on the outer side of the polyester base sheet layer. Co-extruded as possible.

The polyester layer containing the particles is characterized by containing 0.01 to 5% by weight of particles.

In the carrier film for forming a green sheet of the present invention, the silicone release layer is formed by a silicone release composition in which an alkenyl polysiloxane, a hydrogen polysiloxane, a silane coupling agent and a platinum chelate catalyst are contained in an organic solvent as a solid content, and the solid content is 0.5. To 3% by weight.

In the hydrogen polysiloxane molecule, the hydrogen group preferably contains 1.0 to 2.0 per alkenyl group present in the alkenyl polysiloxane molecule.

According to the present invention, there was provided a carrier film for forming a green sheet including a silicone release layer on at least one surface of a polyester base sheet layer having an antistatic coating layer in one step.

Thus, the carrier film of the present invention has excellent antistatic properties, low surface roughness and particularly uniform surface without coarse protrusions on the surface. In addition, when applied to the green sheet forming process, due to the excellent peeling properties of the silicone release layer can be improved in the poor peeling phenomenon generated during the peeling of the green sheet and the carrier film.

Hereinafter, the present invention will be described in detail.

The present invention comprises a silicon release layer on at least one surface of the polyester substrate sheet layer in-line coated with an antistatic coating layer, wherein the silicon release layer is a carrier film for forming a green sheet that satisfies the following equations (1) and (2) to provide.

Equation 1

RF ≤ 10

Equation 2

N_0.5 <1

(In the above, RF is the peel force (g _f / inch) of the silicon release layer with respect to the green sheet, N_0.5 is the number of protrusions of 0.5㎛ or more in the area of 1mm 2 with respect to the silicon release layer.)

Since the carrier film for forming a green sheet of the present invention includes a polyester base sheet layer provided with an antistatic coating layer in one step by inline coating, the carrier film has an excellent antistatic property with a surface resistance of 10 ¹² Pa / sq or less.

Hereinafter will be described the layer-specific characteristics of the carrier film for green sheet molding of the present invention.

1) Polyester base sheet layer

The polyester base sheet layer of the present invention may use a known base film used in the conventional silicone release coating field. More specifically, the present invention will be described with reference to polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and the like, but the description of the silicone release composition of the present invention is not limited to polyester sheets or films. The polyester resin constituting the film is a polyester obtained by polycondensing an aromatic dicarboxylic acid and an aliphatic glycol, and the aromatic dicarboxylic acid isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid , Adipic acid, sebacic acid, oxycarboxylic acid (for example, P-oxybenzoic acid, etc.) are used, and as aliphatic glycol, ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol , Neopentyl glycol and the like can be used. The said polyester resin can also use 2 or more types of said dicarboxylic acid component and glycol components together, and the copolymer containing a 3rd component is also possible. In addition, the polyester base sheet layer according to the present invention uses a uniaxial or biaxially oriented film having high transparency and excellent productivity and processability.

The polyester base sheet layer of the present invention contains particles in order to give excellent roll-to-roll running characteristics. At this time, the particles to be added can be used without particular limitation to the type and shape if it can give excellent sliding properties.

As an example, the present invention includes the use of particles of silica, silicon oxide, calcium carbonate, calcium sulfate, calcium phosphate, magnesium carbonate, magnesium phosphate, barium carbonate, kaolin, aluminum oxide, titanium oxide and the like. The particle shape to be used is also not particularly limited, but any one of spherical shape, block shape, rod shape, and plate shape may be used.

The hardness, specific gravity, and color of the particles are not particularly limited, but two or more kinds may be used in combination as necessary.

At this time, the average particle diameter of the particles used in the polyester base sheet layer of the present invention is preferably 0.1 to 3㎛, more preferably 0.1 to 2㎛ range. At this time, when the average particle diameter of the particles is less than 0.1㎛, the aggregation phenomenon between the particles occurs due to the dispersion failure, if the average particle diameter exceeds 3㎛, the surface roughness characteristics of the film may be deteriorated may cause coating defects during post-processing. .

In addition, the content of the particles contained in the polyester base sheet layer is preferably from 0.01 to 5% by weight, more preferably from 0.01 to 3% by weight. At this time, when the particle content is less than 0.01% by weight, the slip characteristics of the polyester base sheet layer may be poor, and the running characteristics between the rolls may be deteriorated, and when the particle content is more than 5% by weight, the surface smoothness of the film becomes poor.

In order to improve the smoothness of the film while improving the running property, the polyester base sheet layer of the present invention can be produced by uniaxially or biaxially oriented film by molding the sheet using a coextrusion method.

More preferably, the polyester base sheet layer of the present invention may be produced by forming a sheet in a laminated structure by a coextrusion method and uniaxially or biaxially stretching to improve runability and film smoothness.

The laminated structure is preferably two or more layers by the co-extrusion method, and in the embodiment of the present invention, a polyester base sheet layer having a three-layer structure of a particle-containing polyester layer, a particle-free polyester layer, and a particle-containing polyester layer Is described as a preferable example. At this time, by arranging the particle-containing polyester layer in the outermost layer of the polyester base sheet layer, the running property and the smoothness of the film can be improved.

2) Antistatic coating layer

In the carrier film for forming a green sheet of the present invention, the antistatic coating layer is formed by an in-line coating method during the polyester base sheet manufacturing process to impart antistatic property to a uniaxial or biaxially stretched polyester base sheet layer in one step.

At this time, the composition for forming the antistatic coating layer can be used selectively without limitation to the known antistatic coating composition, preferably formed of a composition containing a conductive polymer.

3) silicon release layer

In the carrier film for forming a green sheet of the present invention, the silicone release layer is formed on at least one surface of the polyester base sheet layer provided with antistatic property.

The silicone release layer is prepared by applying a release agent containing polymer silicone as a main component to at least one surface of a polyester base sheet layer and curing the release agent. A release agent may be a solvent type, a solventless type, an emulsion type silicone release agent, and the like. It can be adopted and used in the formation method (Korean Patent Publication Nos. 2004-0036400, 2006-0081120 and 2008-0081832).

However, the silicone release layer of the present invention is characterized in that the alkenyl polysiloxane, hydrogenpolysiloxane, silane coupling agent and platinum chelate catalyst are formed by the silicone release composition contained in the organic solvent as a solid content.

At this time, the solid content contained in the silicone release composition is diluted to contain 0.5 to 3% by weight, and then coated on the easily adhesive layer. The organic solvent used in the silicone release composition may be used without particular limitation as long as it is capable of dispersing the solid content and applying it onto the polyester base sheet layer.

In the silicone release composition, if the total solid content is less than 0.5% by weight, a uniform silicone coating layer is not formed, the tearing of the greensheet occurs when peeling with the carrier film after forming the green sheet, if more than 3% by weight The uniformity of the thickness of the green sheet is poor due to the leveling unevenness of the silicon release layer.

Alkenyl polysiloxane in the silicone release composition of the present invention is a main component of the silicone release liquid, it is preferable that at least two alkenyl groups are bonded to a silicon atom per molecule, the molecular structure is any one selected from linear or branched phase. And a structure in which the linear and branched phases coexist. More specifically, the alkenyl group bonded to the silicon atom is selected from the group consisting of vinyl group, allyl group, butenyl group, pentenyl group, hexenyl group and heptenyl group.

In addition, alkenyl groups that bond with silicon atoms in the alkenyl polysiloxane may be located along the molecular chain ends, the side chains of the molecular chains, or the backbone of the molecular chains.

Thus, alkenyl polysiloxanes of the present invention use methylvinylpolysiloxane blocked with trimethylsiloxy groups or dimethylvinylsiloxane groups at both ends of the molecular chain or dimethyl polysiloxane blocked with dimethylvinyl siloxane groups at both ends of the molecular chain. do.

Hydrogenpolysiloxane in the silicone release liquid of the present invention is used as a curing agent, and excellent compatibility with the alkenylpolysiloxane must be premised. In this case, the hydrogen polysiloxane may be used alone or in a mixed form thereof in a linear, branched or cyclic structure. Any type such as an addition type, a condensation type, or an ultraviolet curing type may be used, and a mixed form thereof may be used.

Preferably, the hydrogen polysiloxane preferably contains 1.0 to 2.0 hydrogen groups bonded to silicon atoms with respect to one alkenyl group present in the alkenyl polysiloxane molecule. At this time, when the number of hydrogen groups bonded to the silicon atom is less than 1.0 with respect to one alkenyl group in the alkenyl polysiloxane molecule, good curing properties are not obtained. When the number is more than 2.0, elasticity and physical properties are reduced after curing.

In addition, the silane coupling agent in the silicone release liquid of the present invention has an effect of increasing the crosslinking density of the film to make the film harder, thereby reducing the film deformation during peeling, thereby lowering the peeling force.

Thus, more preferably, a methacryloxypropyltrimethoxy silane coupling agent capable of improving not only the crosslinking density of the coating but also the adhesion to the substrate can be used.

The platinum chelate catalyst used in the silicone release liquid can be used without particular limitation within the range used for a conventional release layer.

The silicone release layer according to the present invention may use a known coating method selected from a bar coating, a gravure coating, a die coating, etc., on a polyester base sheet layer.

In addition, the silicone release layer may be formed by an in-line coating method performed during a polyester film manufacturing process or an off-line coating method performed after a polyester film production, and is not limited to any one method.

Hereinafter, the present invention will be described in more detail with reference to Examples.

This embodiment is intended to illustrate the present invention in more detail, and the scope of the present invention is not limited to these examples.

Preparation Example 1 Preparation of Polyester A

To 100 parts by weight of dimethyl terephthalate and 100 parts by weight of the dimethyl terephthalate, a raw material composition to which 60 parts by weight of ethylene glycol, 0.1 parts by weight of magnesium acetate and 0.03 parts by weight of antimony trioxide was added was heated and heated to transesterify. Thereafter, 0.025 parts by weight of trimethyl phosphoric acid was added to the transesterification product, and then transferred to a polycondensation reaction tank. Subsequently, the reaction system was gradually reduced in pressure while heating up, and then polymerized in a vacuum atmosphere at 290 ° C to prepare a polyester polymer having an intrinsic viscosity of 0.65 dl / g. The glass transition temperature of the obtained polymer was 80 degreeC, and melting | fusing point was 256 degreeC.

Preparation Example 2 Preparation of Polyester B

A polyester polymer was prepared in the same manner as in the preparation of Polyester A, except that the raw material composition of Preparation Example 1 was added so that the average particle diameter of 0.5 μm was contained so that 400 ppm of the final polyester polymer was included.

Preparation Example 3 Preparation of Polyester C

A polyester polymer was prepared in the same manner as in the preparation of Polyester A, except that the raw material composition of Preparation Example 1 was added so that the average particle diameter of 2.7 μm was contained so that 400 ppm of the final polyester polymer was included.

Preparation Example 4 Preparation of Polyester D

A polyester polymer was prepared in the same manner as in the preparation of Polyester A, except that the raw material composition of Preparation Example 1 was added so that the average particle size of 1.5 μm spherical particles was included so that 400 ppm of the final polyester polymer was contained.

Example 1 Manufacture of Carrier Film for Green Sheet Forming

Polyester A and polyester B prepared in Preparation Examples 1 and 2 were formed into a sheet having a B / A / B layer structure at 290 ° C. by a coextrusion method, stretched 3.5 times in the longitudinal direction, and then conductive with in-line coating. Antistatic coating was performed using a polymer. Thereafter, the biaxially stretched polyester base sheet was prepared by stretching, heat setting, and cooling 4.5 times in the width direction. At this time, the thickness of the polyester base sheet was 31㎛, the average surface roughness was 15nm.

On one surface of the polyester base sheet, a silicone release composition was applied to a thickness of 10 μm. At this time, the silicone release composition is 5 parts by weight of hydrogen polysiloxane, 100 parts by weight of alkenylpolysiloxane, 2 parts by weight of methacryloxypropyltrimethoxy silane coupling agent (Shin-Etsu Co., Ltd. product name: KBM-503), platinum chelate catalyst 10 ppm was diluted in a mixed solvent of toluene and methyl ethyl ketone (MEK) 1: 1 to prepare a total solids content of 2% by weight. After the coating, the carrier film for forming a green sheet was formed by heat-treating for 20 seconds in a 180 ° C. hot air dryer.

Example 2 Manufacture of Carrier Film for Green Sheet Forming

In Example 1, except that 5 parts by weight of the methacryloxypropyl trimethoxy silane coupling agent is used in the silicone release composition, it was carried out in the same manner as in Example 1 to prepare a green film forming a carrier film. .

Example 3 Manufacture of Carrier Film for Green Sheet Forming

In Example 1, except that 10 parts by weight of the methacryloxypropyl trimethoxy silane coupling agent is used in the silicone release composition, a carrier film for forming a green sheet was prepared in the same manner as in Example 1. .

Comparative Example 1

In the silicone release composition in Example 1, 5 parts by weight of glycidoxypropyl trimethoxy silane coupling agent (Shin-Etsu Co., Ltd. product name: KBM-403) is used in the same manner as in Example 1 To produce a carrier film for green sheet molding.

Comparative Example 2

Except for co-extrusion of polyester A and polyester C prepared in Preparation Examples 1 and 3 in the polyester base sheet manufacturing process in Example 1 to form a sheet having a C / A / C layer structure, Carrier film for molding a green sheet was prepared in the same manner as in Example 1.

Comparative Example 3

Except for co-extrusion of polyester A and polyester D prepared in Production Examples 1 and 4 in the polyester base sheet manufacturing process in Example 1, to form a sheet of the D / A / D layer structure, Carrier film for molding a green sheet was prepared in the same manner as in Example 1.

<Comparative Example 4>

A carrier film for forming a green sheet was manufactured in the same manner as in Example 1, except that inline antistatic coating was not performed in the polyester base sheet manufacturing process in Example 1.

Experimental Example 1 Surface Resistance Measurement

With respect to the carrier film for molding the green sheet prepared in Examples 1 to 3 and Comparative Examples 1 to 4, using an antistatic measuring instrument (Mitsubishi Co., Ltd .: model name MCP-T600) at a temperature of 25 ℃, 50% relative humidity environment 24 After mounting for a time, the surface resistance was measured according to the JIS K7194 method.

Experimental Example 2 Measurement of the Number of Projections

Projections having a height of 0.5 μm or more in an area of 1 mm 2 using a three-dimensional surface shape measuring instrument (Keyence company model name VK-97) for the green sheet molding carrier films manufactured in Examples 1 to 3 and Comparative Examples 1 to 4 After counting the number of and measuring five samples, the average value was expressed as N_0.5.

Experimental Example 3 Measurement of Peel Force of Green Sheet

1. Preparation of Ceramic Composition

It was prepared by diluting 5 parts by weight of polyvinyl butyral resin as 10 parts by weight of toluene and methyl ethyl ketone (MEK) 1: 1 mixed solvent with respect to 100 parts by weight of barium titanate as ceramic powder.

2. Green Sheet Manufacturing

On the silicon release layer surface of the carrier film for green sheet molding prepared in Examples 1 to 3 and Comparative Examples 1 to 4, the ceramic composition was coated to a WET thickness of 10㎛ level and dried to prepare a green sheet.

3. Peel force analysis sample preparation

The green sheet / carrier film laminated sample was cut to a size of 25 mm × 150 mm, then aged at room temperature for 24 hours, and the peel force was measured under the following conditions.

Measuring instrument: Chem Instruments Inc. [chem-instrument AR-1000]

Measuring method: 180 ° peeling angle, peeling speed 12 in / min

Measurement data: Peel force unit is g _f / in. The measured value is calculated 5 times to calculate the average value

Experimental Example 4 Appearance Characteristics of Green Sheet Peeling

When peeling the silicone release coating layer from the green sheet prepared in Experimental Example 3, the appearance characteristics of the green sheet film were visually observed and evaluated based on the following criteria.

○: The green sheet film is not damaged at all.

(Triangle | delta): A pinhole generate | occur | produces, although a green-sheet film is not damaged.

×: Green sheet film is not peeled off or part of film is torn and damaged

As can be seen in Table 1, in the carrier film for molding the green sheet of Examples 1 to 3 according to the present invention, the silicone release layer exhibits a low peeling force during the peeling of the green sheet and the carrier film, thereby achieving good peeling. The stability was confirmed.

However, in the case of Comparative Example 1 in which the glycidoxy propyl trimethoxy silane coupling agent was used instead of the methacryloxy silane coupling agent in the manufacture of the silicone release layer, the peeling force was increased, so that the green sheet film was peeled off when the green sheet was peeled off. The damage result was confirmed. In addition, in the case of the carrier film of Comparative Example 4 without the antistatic coating layer, damage to the green sheet film frequently occurred due to local static electricity generation during peeling from the green sheet.

In Comparative Examples 2 and 3, the number of protrusions on the surface of the silicon release layer transferred from the polyester base sheet layer was observed to be 1 or more, so that the thickness of the green sheet was reduced due to the coarse protrusion, thereby peeling off the silicon release layer from the green sheet. This can cause pinholes.

As described above, the present invention provides a carrier film for forming a green sheet on which at least one surface of a polyester base sheet layer having an antistatic coating layer is formed.

Accordingly, the carrier film for forming a green sheet of the present invention has excellent antistatic properties as the antistatic coating layer is provided in one step by inline coating, and has a surface of the silicon release layer formed on at least one surface of the polyester base sheet layer. Since the coarseness is small and the surface is uniform, and shows excellent peeling stability at the time of peeling with the green sheet by the silicon release layer, it is possible to improve the peeling failure phenomenon generated during peeling of the green sheet and the carrier film.

While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (8)

A carrier film for forming a green sheet, wherein the antistatic coating layer comprises a silicon release layer on at least one surface of an inline-coated polyester base sheet layer, wherein the silicon release layer satisfies Equations 1 and 2 below:
Equation 1
RF ≤ 10
Equation 2
N_0.5 <1
In the above, RF is the peel force (g _f / inch) of the silicon release layer to the green sheet, N_0.5 is the number of protrusions of 0.5㎛ or more in the area of 1mm 2 with respect to the silicon release layer. The carrier film for forming a green sheet according to claim 1, wherein the carrier film for forming a green sheet has an antistatic property with a surface resistance of 10 ¹² Pa / □ or less. The carrier film for forming a green sheet according to claim 1, wherein the polyester base sheet layer has a laminated structure of two or more layers by coextrusion. The carrier film for forming a green sheet according to claim 3, wherein the polyester base sheet layer is coextruded so that a polyester layer containing 0.1 to 3 탆 particles is formed outside. The carrier film for forming the green sheet according to claim 4, wherein the polyester layer containing the particles contains 0.01 to 5% by weight of particles. The carrier for forming the green sheet according to claim 1, wherein the silicone release layer is formed of a silicone release composition in which an alkenyl polysiloxane, hydrogenpolysiloxane, silane coupling agent, and a platinum chelate catalyst are contained in an organic solvent in solid content. film. The carrier film for forming the green sheet according to claim 6, wherein the solid content is contained in an amount of 0.5 to 3% by weight. The carrier film for forming the green sheet according to claim 1, wherein 1.0 to 2.0 hydrogen groups in the hydrogen polysiloxane molecule are contained per one alkenyl group in the alkenyl polysiloxane molecule.