JPH10229027A - Carrier sheet for manufacturing ceramic capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a uniform ceramic green sheet thin film and facilitate carrier sheet handling by providing a silicone mold releasing layer on one face of a polyester film having a specific center line average height and forming a layer of a specific center line average height on the opposite face. SOLUTION: A silicone mold releasing layer is provided on one face of a polyester film having a center line average height (Ra) of 0.01μm or less, a layer having a center line average height (Ra) of 0.01-0.1μm is provided on the opposite face and a carrier sheet for manufacturing a ceramic capacitor is formed. The mold releasing layer is formed of a hardening type silicone resin, which can be the one generally known as mold releasing agent. The layer which gives a sliding characteristic is provided on the face opposite to the face whereupon the mold releasing layer is provided, by applying a mixed material of an organic resin binder and filters. For instance, silica and calcium carbonate can be used as excellent fillers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a carrier sheet for producing a ceramic capacitor, and more particularly, to a carrier sheet capable of producing a thin and uniform ceramic green sheet.

[0002]

2. Description of the Related Art In recent years, the use of ceramic chip capacitors has increased remarkably with the miniaturization of electronic devices. In particular, usage of mobile communication devices and the like has been remarkably increased due to miniaturization and low power consumption.

Conventionally, this ceramic chip capacitor uses a slurry in which ceramic powder, a solvent, a binder, and other additives (such as a plasticizer, a dispersant, and an antistatic agent) are uniformly dispersed by an appropriate mechanical dispersion method. It is applied on a carrier sheet by a casting method, and then dried to form a ceramic green sheet. An internal electrode is printed on the sheet, cut into a predetermined size, laminated and sintered, and an external electrode is formed. It was manufactured by attaching. In particular, since the accuracy of the thickness at the stage of forming the ceramic green sheet greatly affects the electric properties of the final chip capacitor, not only the preparation of the slurry but also the carrier sheet, foreign matter on the surface, High-precision surface characteristics such as uniform flatness and thickness uniformity have been required. Also, with the miniaturization of electronic devices, chip capacitors themselves have also been miniaturized, so the thickness of a single ceramic green sheet needs to be reduced to a few μm, and protrusions on the surface of the carrier sheet have been smaller than before. Demands have become stricter.

The causes of the protrusions on the surface of the carrier sheet are not only foreign matters such as dust adhering to the surface of the carrier sheet, but also internal additives such as plastics constituting the carrier sheet, particularly coarse particles of filler such as lubricant. Many. The former surface foreign matter can be reduced by cleaning the carrier sheet manufacturing process,
For the latter internal foreign matter, it is necessary to reduce the particle size of the filler, further reduce the amount of the filler, and take measures such as passing the molten plastic through a filter.

[0005] However, for example, when the particle size of the lubricant is reduced and the amount of the lubricant added is reduced, the surface roughness of the carrier sheet becomes extremely flat, the slip between the sheets becomes poor, and the sheets stick to each other. In particular, when a silicone elastomer-based release layer is provided on the surface of the carrier sheet, the above-mentioned problem becomes even more remarkable. For this reason, handling of the carrier sheet in the manufacturing process of the ceramic green sheet may be seriously hindered.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to improve the disadvantages of the prior art, to produce a uniform ceramic green sheet thin film, and to handle a carrier sheet in the process of producing a ceramic green sheet. To provide a carrier sheet for producing a ceramic green sheet which is easy to use.

[0007]

According to the present invention, there is provided a polyester film having a center line average roughness (Ra) of not more than 0.01 μm provided with a silicone release layer on one side and a center line average roughness on the opposite side. This is a carrier sheet for producing a ceramic capacitor provided with a layer having (Ra) of 0.01 to 0.1 μm.

[0008] A polyester film is used as the base film of the carrier sheet for producing a ceramic capacitor of the present invention. For applications where transparency is required, it is preferable to use a polyester film with good transparency,
Particularly, a biaxially stretched polyester film is preferable. Also,
For applications requiring light-shielding properties, it is preferable to use a polyester film containing an inorganic pigment.
A white biaxially stretched polyester film containing a pigment such as O ₂ or SiO ₂ is preferred.

The polyester constituting such a polyester film is a crystalline linear saturated polyester comprising an aromatic dibasic acid component and a diol component, and is, for example, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, or polyethylene-2. , 6-naphthalate and the like. Of these, polyethylene-2,6-naphthalate or polyethylene terephthalate is preferred. Further, an improving agent other than those described above can be added to the polyester.

[0010] The polyester film used in the present invention can be produced by a conventionally known method. For example, a biaxially stretched polyester film is obtained by drying a polyester, melting it at a temperature of Tm to (Tm + 70) ° C. (where Tm is the melting point of the polyester) with an extruder, and forming a die (eg, a T-die, an I-die, etc.). ), And extruded on a rotary cooling drum, and quenched at 40 to 90 ° C. to produce an unstretched film.
0) to (Tg + 70) ° C. (Tg: glass transition temperature of polyester), stretching in the longitudinal direction at a magnification of 2.5 to 8.0 times, and stretching in the transverse direction at a magnification of 2.5 to 8.0 times. If necessary, it can be manufactured by heat setting at a temperature of 180 to 250 ° C. for 1 to 60 seconds. Film thickness is 5-25
A range of 0 μm is preferred.

A release layer is provided on one side of the base film, but an anchor coat layer may be provided between the two layers to improve the adhesion between the base film and the release layer. As such an anchor coat layer, a silane coupling agent can be preferably used. The silane coupling agent include those represented by the general formula Y-Si-X _3. Here, Y represents a functional group represented by an amino group, an epoxy group, a vinyl group, a methacryl group, or a mercapto group, and X represents a hydrolyzable functional group represented by an alkoxy group. The thickness of the anchor coat layer is 0.01 to 5
The range of μm is preferred, and the range of 0.02 to 2 μm is particularly preferred.

The release layer is formed of a curable silicone resin. As the curable silicone resin, those generally known as release agents can be used. For example, “Silicone Material Handbook” (edited by Toray Dow Corning,
1993. 8) and the like. For example, KS-847 (H) and KS-776 manufactured by Shin-Etsu Silicone Co., Ltd., and TPR-6700 manufactured by Toshiba Silicone Co., Ltd. can be exemplified. As these curing methods, heat or radiation curing types are generally used. Specifically, the following curing methods are mentioned.

[0013] Thermal condensation reaction type: A reaction in which dimethylpolysiloxane having silanol groups at both ends is reacted with methylhydrogenpolysiloxane or methylmethoxysiloxane in the presence of an organotin-based catalyst. -Thermal addition reaction type: A product obtained by reacting methylvinylpolysiloxane having a vinyl group at both molecular terminals or at both terminals and side chains with methylhydrogenpolysiloxane in the presence of a platinum-based catalyst. -UV curing type (radical addition type): a siloxane containing an alkenyl group and a mercapto group and a photopolymerizing agent added. -Ultraviolet curing type (hydrosilyl type): One using the same platinum-based catalyst as the heat addition reaction type. -UV curing type (radical polymerization type): a siloxane containing a (meth) acrylic group and a photopolymerizing agent added. -Ultraviolet curing type (cation polymerization type): An epoxy group-containing siloxane with an onium salt photoinitiator added. -Electron beam curing type: a siloxane containing a radical polymerizable group (there is no need for a functional group and no photo initiator).

The form of the curable silicone resin can be appropriately selected from solvent type, emulsion type, solventless type and the like.

Further, a slipperiness imparting layer is provided on the surface opposite to the surface on which the release layer is provided. Center line average roughness of this layer (Ra)
Needs to be 0.01 to 0.1 μm. If the center line average roughness (Ra) is less than 0.01 μm, the carrier sheet may cause blocking, which is not preferable. On the other hand, if it exceeds 0.1 μm, a filler having a large average particle size is used for the slipperiness imparting layer, so that the separation may occur. It is not preferable because it affects the surface of the shape layer.

The structure of this layer can be provided by applying a combination of an organic resin binder and various fillers. There is no particular limitation on the combination of the binder and the filler. Organic resin binders include condensation-polymerized resins such as saturated polyesters, polyurethanes, alkyds, epoxies, and amino resins, and addition-polymerized resins such as acrylics, vinyl chloride / vinyl acetate copolymers, and butyral. It is preferable to use them alone or in combination.

As the filler, inorganic fine particles such as silica, calcium carbonate, barium sulfate, talc, kaolin, china clay and titanium oxide, polyethylene,
It is preferable to use organic resin fine particles such as acryl, styrene and benzoguanamide alone or in combination.

The mixing ratio (binder / filler) of the binder and the filler is preferably 95/5 to 80/20 by weight, and the average particle size of the filler is 0.002 to 0.15.
μm is preferable, and 0.01 to 0.15 μm is more preferable. Further, in addition to the binder and the filler, a slip aid such as polyethylene wax, carnauba wax, and silicone oil may be added.

The slipperiness imparting layer is applied by a known coating method. For example, a roll coating method, a gravure coating method and the like can be mentioned. Further, the coating may be performed on the polyester film before the completion of the crystal orientation, or may be performed on the polyester film after the completion of the crystal orientation,
From the viewpoint of production cost, it is preferable to perform the process on the polyester film before the crystal orientation is completed.

The coating amount of the coating liquid is 3 to 10 g / m ^2.
The range of (wet) is preferable. The order in which the release layer and the slipperiness imparting layer are provided is preferred because blocking of the release layer can be prevented by providing the slipperiness imparting layer first, and then providing the release layer.

[0021]

The present invention will be described below in detail with reference to examples. In the examples, “parts” means “parts by weight”. The physical property values and characteristic values in the present invention were measured by the following methods.

(1) Peeling strength (rubbing test) A polyester pressure-sensitive adhesive tape (Nitto 31B) is adhered to the release layer surface of the film, pressure-bonded with a 5 kg pressure roller, left for 20 hours, and then separated from the release layer and the pressure-sensitive adhesive tape. The force was measured with a tensile tester.

(2) Residual Adhesion Rate JIS polyester adhesive tape (Nitto 31B)
Cold rolled stainless steel sheet (SUS3
04) was measured for the peeling force after application, and the result was taken as the basic adhesive force (f ₀ ). In addition, the polyester adhesive tape was stuck on the release layer coating surface of the sample film, and 5 kg
And then left for 30 seconds to peel off the adhesive tape. Then, the peeled adhesive tape was stuck on the above stainless steel plate, and the peeling force of the stuck portion was measured to obtain a residual adhesive force (f). From the obtained basic adhesive strength and residual adhesive strength, a residual adhesive rate was determined using the following equation.

[0024]

## EQU1 ## Residual adhesion rate (%) = (f / f ₀ ) × 100

(3) Surface roughness Ra (Center Line Averag)
e: center line average roughness) According to JIS B0601, using a high-precision surface roughness meter (SE-3FAT) manufactured by Kosaka Laboratory Co., Ltd., a needle radius of 2 μm, a load of 30 mg, a magnification of 200,000 times, The chart was drawn under the condition of cutoff 0.08 mm, the portion of the length L measured in the direction of the center line was extracted from the film surface roughness curve, the center line of the extracted portion was extracted, and the center line of the extracted portion was extracted. When the roughness curve is represented by Y = f (x) with the direction of the X axis and the direction of the longitudinal magnification being the Y axis, the value given by the following equation is represented in μm.

[0026]

(Equation 2)

This measurement was performed with the reference length set to 1.25 mm.
Each was measured and expressed as an average value.

(4) Slipperiness (Film Coefficient of Friction (Film Slippery)) A coated surface and a polyester film (non-coated surface) using a slippery measuring device manufactured by Toyo Tester Co., Ltd. in accordance with ASTM D1894-63. And the coefficient of static friction (μs) was measured. However, the thread plate was a glass plate, and the load was 1 kg. The slipperiness was evaluated according to the following criteria. 〇: good (static friction coefficient less than 0.6) △: slightly poor (static friction coefficient is 0.6 or more, 0.8
×): poor (static friction coefficient is 0.8 or more)

(5) Blocking property The film was put on the front and back sides, a load of 50 kg / cm ² was applied, and the film was maintained at 50 ° C. for 20 hours. Next, the peel strength at the time of peeling the laminated film was measured with a tensile tester at a tensile speed of 300
It was measured under the condition of mm / min.

Example 1 56 parts (as a non-volatile component) of an aqueous polyurethane dispersion having a carboxylamine base (trade name: Mercy 585, manufactured by Toyo Polymer Co., Ltd.), polyethylene wax emulsion (melting point: about 105 ° C.)
7 parts, aqueous colloidal silica dispersion (average particle size of 40 to 50)
nm) and polyoxyethylene nonylphenyl ether (manufactured by NOF Corporation, trade name NS-208.
5) Dilute 10 parts with ion-exchanged water, dissolve
A weight-% slip coating liquid was prepared.

Polyethylene terephthalate containing no inorganic filler having an intrinsic viscosity of 0.65 as measured in o-chlorophenol at 25 ° C. was extruded from a die with an extruder, and was then cooled on a drum cooled to 40 ° C. The film was quenched while applying a voltage to obtain an unstretched film having a thickness of 152 μm, and then stretched 3.6 times in the longitudinal direction on a metal roll heated to 93 ° C.

Next, at a position immediately before the uniaxially stretched film, which had been subjected to longitudinal stretching, entered the tenter, the above-mentioned coating solution was uniformly applied to one surface of the film by a kiss coating method.
The average coating amount at this time was 4 g (wet) per 1 m ^{2 of the} uniaxially stretched film.

At this time, on the opposite side of the uniaxially stretched film, a 3% by weight aqueous solution of 3-glycidoxypropyltrimethoxysilane (containing a surfactant) as an anchor coat layer of a release layer was added at 5 g / m ^2. (Wet) amount was simultaneously applied and dried. A curable silicone resin of the type in which a platinum catalyst is added to a mixed solution of polydimethylsiloxane and dimethylhydrogensilane to cause an addition reaction (Shin-Etsu Silicone Co., Ltd., trade name K
S-847 (H)) in a mixed solvent of methyl ethyl ketone, methyl isobutyl ketone and toluene was applied at a coating amount (wet) of 8 g / m ² and dried at 130 ° C. for 30 seconds. After curing, a release film having a coating film thickness of 0.24 μm was obtained. Table 1 shows the characteristics of the release film.

Example 2 Mold release was performed in the same manner as in Example 1 except that polyethylene-2,6-naphthalate having an intrinsic viscosity of 0.62 measured in o-chlorophenol at 25 ° C. was used instead of polyethylene terephthalate. A film was made. Table 1 shows the characteristics of the release film.

Comparative Example 1 A release film was prepared in the same manner as in Example 1 except that the slip coating solution was not applied. However, in this release film, blocking occurred in the winding core, and it was difficult to feed out the film. Table 1 shows the characteristics of the release film.

[0036]

[Table 1]

[0037]

According to the present invention, it is possible to obtain a carrier sheet for producing a ceramic green sheet in which a uniform ceramic green sheet thin film can be produced and the carrier sheet can be easily handled in the production process of the ceramic green sheet. Can be.

Claims (4)

[Claims] 1. The center line average roughness (Ra) is 0.01 μm.
A carrier sheet for producing a ceramic capacitor in which a silicone release layer is provided on one side of the following polyester film and a layer having a center line average roughness (Ra) of 0.01 to 0.1 μm is provided on the opposite side. 2. The carrier sheet according to claim 1, wherein the polyester film is a polyethylene terephthalate film. 3. The polyester film is polyethylene-
The carrier sheet according to claim 1, which is a 2,6-naphthalate film. 4. A center line average roughness (Ra) of 0.01 to
The carrier sheet according to claim 1, wherein the layer having a thickness of 0.1 µm is provided by applying a mixture of a binder and a filler.