KR20110075621A - Carrier film for green sheet - Google Patents

Abstract

PURPOSE: A carrier film for green sheet molding is provided to go through adhesion coating and silicon coating process to remove the pulled-out phenomenon generated in the exfoliation of the green sheet and the carrier film with the pinhole inferiority and the non-uniform coating which can be created in the thin film green sheet molding. CONSTITUTION: The carrier film for green sheet molding includes: an adhesive coating layer; a silicon release coating layer. The adhesive coating layer is spread in one side of the polyester film and polyester film. The silicon release coating layer is spread at least one time on the adhesive coating layer as the silicon release composition. The carrier film for green sheet molding meets the "SR <= 30 nm" formula. "SR" is the center line average roughness value(Ra) of the silicon release coating layer surface.

Description

Carrier Film for Green Sheet Forming {Carrier Film For Green Sheet}

The present invention relates to a carrier film for green sheet molding, and more particularly, to pinhole defects and non-uniform coatings that may occur during thin film green sheet molding with excellent surface roughness characteristics when used as a carrier film in a green sheet molding process. The present invention relates to a carrier film for forming a green sheet which can improve a tearing phenomenon generated during peeling of the green sheet and the carrier film.

Generally, MLCC (Multilayer Ceramic Capacitor) is a general-purpose core component commonly used in electronic products such as mobile phones and LCD TVs, and plays a role in flowing current required by the product. In general, in processing a green sheet used in a multilayer ceramic capacitor, a silicone release film based on a polyester film is used as a carrier film for green sheet molding.

Recently, due to the miniaturization and thinning of electronic products, ceramic multilayer capacitors are also being miniaturized and large in capacity, and the thickness of the green sheet is gradually becoming thinner. In order to reduce the thickness of the green sheet, the solids and the viscosity of the ceramic slurry need to be lowered, and the thin film is required to have a thin coating on the molding carrier film.

In addition, when the ceramic slurry is required to coat a thin film with a low solid content, when the surface roughness of the carrier film is high, defects in the form of pinholes occur after coating the ceramic slurry, and short-circuiting of current occurs at the defect site after MLCC processing. Is more likely to be. In addition, there may be a problem that the sheet is torn apart when peeling the green sheet by the non-uniform coating of the ceramic slurry.

The present invention has been made to solve the above problems, an object of the present invention is a tearing phenomenon generated during the peeling of the green sheet and the carrier film by the pinhole defect and non-uniform coating that may occur when forming a thin film green sheet. The purpose of the present invention is to provide a carrier film for forming a green sheet having excellent surface roughness characteristics through an easy-adhesive coating and a silicon coating process.

These and other objects and advantages of the present invention will become more apparent from the following description of a preferred embodiment thereof.

The object is as a carrier film for forming a green sheet comprising a polyester film, an adhesive coating layer applied to at least one surface of the polyester film and a silicone release coating layer applied at least once with a silicone release composition on the adhesive coating layer. ,

Satisfy the following formula 1,

SR ≤ 30 nm (Equation 1)

Here, "SR" is achieved by the carrier film for green sheet molding, characterized in that the center line average roughness value Ra of the surface of the silicone release coating layer.

Preferably, the carrier sheet for forming the green sheet further satisfies the following Equation 2,

MP ≤ 0.4 μm (Equation 2)

Here, "MP" is characterized in that the value (Rmax) of the maximum height of the surface coating of the silicone release coating layer.

Preferably, the green sheet forming carrier film satisfies the following Equation 3,

RF ≤ 15 mN / 30mm (Equation 3)

Here, "RF" is a peel force value between the green sheet and the silicon release coating layer surface in a state where the green sheet is laminated on the silicon release coating layer surface.

Preferably, the easily adhesive coating layer is characterized in that it comprises a silane coupling agent.

Preferably, the coating thickness of the easily adhesive coating layer is characterized in that 0.05 ~ 0.5 g / m ² .

More preferably, the silicone release composition is characterized in that it comprises an alkenyl polysiloxane, hydropolysiloxane and platinum chelate catalyst.

According to the present invention, when used as a carrier film in the green sheet forming process, due to the excellent surface roughness characteristics, tears generated during peeling of the green sheet and the carrier film due to poor pinhole properties and uneven coating that may occur during thin film green sheet molding. It is possible to improve the phenomenon.

Hereinafter, the present invention will be described in detail with reference to examples of the present invention. These examples are only presented by way of example only to more specifically describe the present invention, it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples. .

Carrier film for forming a green sheet according to the present invention comprises a polyester film, an adhesive coating layer applied to at least one surface of the polyester film and a silicone release coating layer applied at least once with a silicone release composition on the adhesive coating layer. As a carrier film for green sheet molding,

Satisfy the following formula 1,

SR ≤ 30 nm (Equation 1)

Here, “SR” is a centerline average roughness value Ra of the surface of the silicon release coating layer.

In addition, the carrier sheet for forming the green sheet is more satisfying the following formula 2,

MP ≤ 0.4 μm (Equation 2)

Here, "MP" is characterized in that the value (Rmax) of the maximum height of the surface coating of the silicone release coating layer.

In the carrier film for forming a green sheet according to the present invention, as the green sheet is thinned, the center line average roughness value Ra of the surface of the silicon release coating layer is 30 nm or less, and the maximum height Rmax of the surface protrusion is required to be 0.4 μm or less. In order to satisfy this, it is preferable to introduce the adhesive layer to alleviate the surface roughness of the polyester film. When the centerline average roughness value Ra of the surface of the silicone release coating layer according to the present invention exceeds 30 nm, a non-uniform thickness of the green sheet may occur when processing the green sheet, and the maximum height Rmax of the surface release of the silicone release coating layer may be If the thickness exceeds 0.4 μm, pinhole defects may be generated on the green sheet when the green sheet is processed, and a defect such as an electrical short may occur in the MLCC.

In addition, the carrier sheet for forming the green sheet is more satisfying the following Equation 3,

RF ≤ 15 mN / 30mm (Equation 3)

Here, "RF" is a peel force value between the green sheet and the silicon release coating layer surface in a state where the green sheet is laminated on the silicon release coating layer surface.

In the carrier film for green sheet molding according to the present invention, the peeling force between the green sheet and the carrier film is required to be 15 mN / 30 mm or less. In order to satisfy this, the surface of the polyester film may be roughened by introducing the adhesive layer on the polyester film. It is desirable to reduce the adhesion area between the green sheet and the carrier film by alleviating the pressure. When the peeling force between the carrier film and the green sheet according to the present invention exceeds 15 mN / 30mm, the green sheet film may be torn off when the green sheet and the carrier film are peeled off.

In addition, the polyester film used in the present invention is not limited in kind, but may be a known one conventionally known as a base film of silicone release coating. In the present invention, the description will be focused on polyester-based 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 which comprises the said film refers to the polyester obtained by polycondensing aromatic dicarboxylic acid and aliphatic glycol. As aromatic dicarboxylic acid, terephthalic acid, 2, 6- naphthalene dicarboxylic acid, etc. are mentioned, As aliphatic glycol, ethylene glycol, diethylene glycol, 1, 4- cyclohexane dimethanol, etc. are mentioned.

Typical polyesters include polyethylene terephthalate (PET), polyethylene-2,6-naphthalenedicarboxylate (PEN), and the like. The polyester may also be a copolymer containing a third component. Examples of the dicarboxylic acid component of the copolyester include isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and oxycarboxylic acid (for example, P-oxybenzoic acid). Examples thereof include ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, neopentylglycol and the like. These dicarboxylic acid components and glycol components may use 2 or more types together. Moreover, the base film which concerns on this invention uses the uniaxial or biaxial oriented film which has high transparency and is excellent in productivity and workability.

The polyester film according to the invention also contains particles in order to give excellent roll-to-roll running properties. The added particles are not particularly limited in kind as long as they can exhibit excellent slipping properties. In the present invention, silica, silicon oxide, calcium carbonate, calcium sulfate, calcium phosphate, magnesium carbonate, magnesium phosphate, barium carbonate, kaolin, aluminum oxide, titanium oxide and the like can be included. Although the shape of the particle | grains to be used is not specifically limited, Any of spherical shape, block shape, rod shape, and plate shape particle | grains can be used for this invention. In addition, there are no particular restrictions on the hardness, specific gravity and color of the particles, and two or more kinds may be used in parallel if necessary. Moreover, it is preferable that the average particle diameter of the particle | grains to be used satisfies 0.1-5 micrometers, More preferably, it is the range of 0.1-2 micrometers. If the average particle diameter is less than 0.1㎛ may cause agglomeration between particles, poor dispersion may occur, if the average particle diameter exceeds 5㎛ the surface roughness characteristics of the film may be poor coating failure during post-processing.

Moreover, it is preferable to satisfy | fill 0.01-5 weight% of particle content in a polyester film, More preferably, it is the range of 0.01-3 weight%. When the content is less than 0.01% by weight, the slip characteristics of the polyester film may be deteriorated and the running characteristics between the rolls may be deteriorated. When the content is more than 5% by weight, the surface smoothness of the film may be deteriorated.

In addition, the easy-adhesive coating layer (adhesive layer) of the carrier film for green sheet molding according to the present invention includes a silane coupling agent, and an alkoxy silane having an epoxy group of the following [Formula 1] is preferable.

[Formula 1]

XRSiZ ₃

Here, X is a functional group having an epoxy group, R is an alkylene group such as methylene, ethylene, propylene, etc., Z is a methoxy, ethoxy group, etc. Organic functional groups, such as a functional group and alkyl group which have hydrolyzability, are shown.

Alkoxy silane of the silane coupling agent according to the present invention is, for example, γ-glycidoxy propyl trimethoxy silane, γ-glycidoxy propyl methyl dimethoxy silane (glycidoxy propyl methyl dimethoxy silane) silane), γ-glycidoxy propyl methyl diethoxy silane, and the like.

In addition, the easily adhesive layer according to the present invention may further contain a binder resin. Examples of binder resins used include methacrylates, polyesters, acrylates, polyvinyl alcohols, polyacrylamides, polyalkylene glycols, polyalkylene imines, celluloses, polyurethanes, and epoxys and melamines. It is any one selected from.

In the easily adhesive layer according to the present invention, the coating thickness after coating drying is 0.05 to 0.5 g / m ² , and preferably 0.05 to 0.3 g / m ² . If the film thickness is less than 0.05 g / m ² , the surface roughness of the polyester film may not be alleviated and defects such as pinholes may occur during green sheet processing. If the film thickness exceeds 0.5 g / m ² , the easily adhesive layer may be formed. The leveling property deteriorates and the thickness uniformity of the green sheet deteriorates.

The easily adhesive layer according to the present invention can use a conventionally known coating method such as bar coating, gravure coating, die coating. In addition, it may be carried out by an in-line coating method, which is a method of coating in a polyester film manufacturing process, or may be performed by an off-line coating method, which is a method of coating after a polyester film is manufactured, but is limited to any one method. It is not.

In addition, the silicone release composition according to the invention is characterized in that it comprises an alkenylpolysiloxane, hydropolysiloxane and platinum chelate catalyst.

The alkenylpolysiloxane may be any type such as addition type, condensation type or ultraviolet curing type in the constitution of the silicone release composition according to the present invention, and is not particularly limited to any one type. The alkenylpolysiloxane contains an alkenyl group in a molecule, alkenyl groups may be present in any part of the molecule, and preferably at least two are present. The molecular structure may be linear or branched, or may be a structure in which both linear and branched molecules are present.

Moreover, as a hardening | curing agent in the structure of the silicone mold release composition which concerns on this invention, any type, such as an addition type, condensation type, and an ultraviolet curing type, can be used, It does not specifically limit to any one. The hydropolysiloxane may be either linear, branched or cyclic, or a mixture thereof. In addition, the viscosity and molecular weight are not limited, but compatibility with the alkenylpolysiloxane should be good, and the amount of use thereof is in the range of 1.0 to 2.0 hydroelectrons bonded to silicon atoms with respect to one alkenyl group of the alkenylpolysiloxane. It is preferable. If there are less than 1.0 hydrogen atoms bonded to a silicon atom for one alkenyl group of the alkenyl polysiloxane, there may be a problem in that it is difficult to obtain good curability, and if more than 2.0, there is a problem in that elasticity or physical properties after curing are degraded. There may be.

In addition, the silicone release composition according to the present invention is diluted in a solvent so as to have a total solid content of 0.5 to 3% by weight and then coated on the adhesive layer. The solvent used in the coating composition is not limited as long as it can be applied to the polyester film by dispersing the solid content of the present invention. If the total solid content of the silicone release composition is less than 0.5% by weight, a uniform silicone coating layer may not be formed, and thus problems such as tearing of the green sheet may occur when peeling from the carrier film after molding the green sheet, resulting in 3% by weight. If exceeded, the thickness uniformity of the silicon coating layer may worsen the thickness uniformity of the green sheet.

Hereinafter, the present invention will be described in detail by using examples and comparative examples of the present invention.

[Example]

<Production of Easy Adhesive Coating Film>

Preparation Example 1: Adhesive Coating Film A1

100 parts by weight of the alkoxy silane coupling agent to 100 parts by weight of the polyalkyl acrylate binder resin was applied to the corona discharge-treated surface of the polyester film by coating and drying the easily-adhesive coating composition prepared in 1.0% by weight of solids using water as a solvent. The easily-adhesive coating film A1 of thickness 0.05 g / m <^2> was obtained.

Preparation Example 2: Adhesion Coating Film A2

In Production Example 1, the easily-adhesive coating composition prepared at a solid content of 3.0% by weight was applied and dried to obtain an easily-adhesive coating film A2 having a film thickness of 0.15 g / m ² .

Preparation Example 3: Adhesive Coating Film A3

In Production Example 1, the easily-adhesive coating composition prepared at a solid content of 6.0% by weight was applied and dried to obtain an easily-adhesive coating film A3 having a coating thickness of 0.3 g / m ² .

Preparation Example 4 Adhesion Coating Film A4

In Production Example 1, the easily-adhesive coating composition prepared at a solid content of 10.0% by weight was applied and dried to obtain an easily-adhesive coated film A4 having a film thickness of 0.5 g / m ² .

Preparation Example 5 Adhesion Coating Film A5

In Production Example 1, the easily-adhesive coating composition prepared at 15.0 wt% of solid content was applied and dried to obtain an easily-adhesive coated film A5 having a film thickness of 0.7 g / m ² .

Example 1

To 100 parts by weight of alkenylpolysiloxane in the coating layer of the easily-adhesive coating film A1, 5 parts by weight of hydropolypolysiloxane and 50 ppm of platinum chelate catalyst were diluted in a solution of toluene and MEK 1: 1, and the total solid content was 2% by weight. Silicone release compositions were prepared and applied to a thickness of 10 microns. After coating, heat-treated for 20 seconds in a 180 ℃ hot air dryer to prepare a carrier film for green sheet molding.

Example 2

Except for using the adhesive coating film A2, it was carried out in the same manner as in Example 1 to prepare a green film forming a carrier film.

Example 3

Except for using the adhesive coating film A3, it was carried out in the same manner as in Example 1 to prepare a carrier film for green sheet molding.

 Example 4

Except for using an adhesive coating film A4, it was carried out in the same manner as in Example 1 to prepare a carrier film for green sheet molding.

[Comparative Example]

[Comparative Example 1]

Carrier film for green sheet molding was prepared in the same manner as in Example 1 on the polyester film was not subjected to any treatment.

 Comparative Example 2

Carrier film for green sheet molding was prepared in the same manner as in Example 1, except that the easily-adhesive coating film A5 was used.

 [Comparative Example 3]

Except that the total solid content of the silicone release composition is 0.3% by weight, it was carried out in the same manner as in Example 1 to prepare a green film forming a carrier film.

[Comparative Example 4]

Except that the total solid content of the silicone release composition is 5% by weight, it was carried out in the same manner as in Example 1 to prepare a green film forming a carrier film.

Evaluation of physical properties of the films prepared in Examples 1 to 4 and Comparative Examples 1 to 4 was carried out in the same manner as shown in Table 1 below.

[Experimental Example]

[Experimental Example 1; Surface roughness measurement]

Using a three-dimensional surface roughness measuring instrument (KOSAKA: model name SE3500K31), the center line average roughness (Ra) value and the maximum height of the surface projections were analyzed using a tip radius of 5 µm, needle pressure 30 mg, measurement length 0.5 mm, and cutoff value of 0.25 mm. (Rmax) and number were measured.

Experimental Example 2; Green Sheet Peeling Force Measurement]

<Ceramic Composition Preparation>

To 100 parts by weight of ceramic powder (barium titanate), 5 parts by weight of binder resin (polyvinyl butyral resin) is diluted to 10 parts by weight of toluene and MEK 1: 1 mixed solvent.

<Green Sheet Manufacturing>

The ceramic composition is coated and dried on a release coating surface of a sample film with a WET thickness of 10 μm to prepare a green sheet.

Peeling Sample Preparation

A green sheet / sample film lamination sample is prepared in a size of 30 mm x 150 mm.

Measuring instrument: chem-instrument AR-1000

Measurement Method: 180 ° Peeling Angle, Peeling Speed 12 in / min

-Measurement data: Peel force is mN / 30mm and the measured value is measured 5 times to calculate the average value

TABLE 1

division Centerline illuminance
(nm) Turning height
(Μm) Peel force
(mN / 30mm) Example 1 26 0.32 12 Example 2 24 0.26 11 Example 3 18 0.31 11 Example 4 15 0.28 10 Comparative Example 1 39 0.59 18 Comparative Example 2 35 0.39 16 Comparative Example 3 28 0.37 31 Comparative Example 4 37 0.39 18

As can be seen in Table 1, Examples 1 to 4 according to the present invention can confirm that the peeling stability for the green sheet is good due to the excellent surface roughness characteristics. However, Comparative Examples 1, 2 and 4 having poor surface roughness characteristics and Comparative Example 3 having insufficient release composition contents may confirm poor peeling stability of the green sheet.

In the present specification, only a few examples of various embodiments performed by the present inventors are described, but the technical idea of the present invention is not limited thereto, but may be variously modified and implemented by those skilled in the art.

Claims (6)

In the carrier film for green sheet molding, A carrier film for forming a green sheet comprising a polyester film, an adhesive coating layer applied to at least one surface of the polyester film, and a silicone release coating layer coated on the adhesive coating layer at least once with a silicone release composition, Satisfy the following formula 1, SR ≤ 30 nm (Equation 1) Here, "SR", characterized in that the center line average roughness value (Ra) of the surface of the silicone release coating layer, green sheet molding carrier film. The method of claim 1, Carrier film for forming the green sheet is more satisfying the following formula 2, MP ≤ 0.4 μm (Equation 2) Here, "MP" is a value (Rmax) of the maximum height of the surface coating of the silicone release coating layer, green sheet molding carrier film. The method of claim 2, Carrier film for forming the green sheet is more satisfying the following Equation 3, RF ≤ 15 mN / 30mm (Equation 3) Here, "RF" is a carrier film for forming a green sheet, wherein the green sheet is laminated on the surface of the silicone release coating layer and the peel force value between the green sheet and the surface of the silicone release coating layer. The method according to any one of claims 1 to 3, The easy-adhesive coating layer is characterized in that it comprises a silane coupling agent, green sheet molding carrier film. The method according to any one of claims 1 to 3, The film thickness of the easy-adhesive coating layer is 0.05 ~ 0.5 g / m ² , characterized in that, green sheet molding carrier film. The method according to any one of claims 1 to 3, The silicone release composition is a carrier film for green sheet molding, characterized in that it comprises an alkenyl polysiloxane, hydropolysiloxane and platinum chelate catalyst.