JPS61123520A - Manufacture of plastic film improved in slip property - Google Patents

Abstract

PURPOSE:To obtain a plastic film for electronic equipment materials that in improved in slip property, by joining a plastic and an inorganic filler-containing resin with the surface of the plastic where it is to be joined being in the melted state so that a laminate film may be formed, and separating the film. CONSTITUTION:A plastic (A) (e.g. a polypropylene, etc.) and a resin (A) (e.g. a polyester, etc.) containing an inorganic filler in an amount, for example, of 0.1wt% or over (in the composition) are joined with at least the surface of the plastic where it is to be joined being in the melted state. Then the formed laminate is separated to obtain the intended plastic film. EFFECT:A film excellent in dielectric breakdown voltage can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a film suitable for electronic equipment. Regarding the method.

(Prior Art and Problems to be Solved by the Invention) Plastic films have been widely used in the past as dielectrics for capacitors and plastic film for electronic equipment such as elements.

In particular, plastic films for electronic equipment have been becoming thinner and thinner in order to achieve smaller size and higher performance.

In the production of metal-deposited film capacitors for thin A electronic equipment, we not only pay attention to the physical performance of the film C, thickness, and thickness, but also the metal deposition process, narrow slitting process, and winding process. If there is poor slippage between the films or between the film and the objects that come into contact with it, it will be difficult to roll the film, causing problems such as wrinkles during the processing process, and reducing the yield of the product. , films with improved slippage have become essential.

As methods for improving the slipperiness, there have been proposed methods such as adding suitable unevenness to the surface of the film by adding vC ring filler to the film to be improved, and adding unevenness to the surface by sandblasting, etc. .

However, in the former method, trace amounts of metals, particles, and dispersants contained in the filler have an undesirable effect on the electrical properties.
In addition, polyester films and poly(1)propylene films that are commonly used for capacitors are biaxially stretched, so in addition to the above problems, voids are generated around the filler, and the film Reduce breakdown voltage? It will be concluded. Further, in the method of using a trowel to avoid the generation of voids, a large amount of foreign matter adheres to the surface of the film, so cleaning or the like is required.

For these reasons, there is a need for a solution that can fully meet market needs.

(Summary of the Invention) The present invention, clearly described above. Current situation [1i, 4ri. Improved,
The purpose of this film is to provide a film for electronic equipment with excellent negative dielectric breakdown voltage, and the film material plastic and a resin containing a ring filler are added to at least the adhesion side surface of the plastic material. The present invention provides a method for producing a plastic film with improved slipperiness, which comprises adhering under molten conditions to form a laminated film, which is then peeled off.

According to the present invention, unevenness is formed by the inorganic filler to which the inorganic filler is added, and this is transferred to the surface of the plastic film, and the core film itself does not contain the inorganic filler. Therefore, even if the film is thinned by stretching in the -axis or biaxial direction, a film with excellent dielectric breakdown voltage without generation of voids etc. can be obtained.

C) The plastic used as a material to form the plastic film of the present invention is not limited, and includes polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene-butene-1 copolymer. Thermoplastic resins used for film molding, such as polyolefins, polyamides, polyesters, poly(IIK) vinyl, polyphenylene ether, polyvinylidene heptafluoride, and polymethylpentene, can be used.

In the present invention, a plastic material for the film and a resin containing an inorganic filler are laminated with at least the adhesive side surface of the glass material for the film in a molten state.

The adhesion between the plastic material and the resin for lamination is such that a part of the film does not peel off in each step after lamination, and a part of the layer 11 remains on the molded body when peeled off during vapor deposition and slit removal. On the contrary, it is desirable that the adhesion area is 1i such that no part of the molded body remains on the coating layer.

The closely laminated state here refers to, for example, resin A and other lubricants.
It refers to the lamination to the extent that it can be peeled off from the surface of etal fat B.

As for the resin used for lamination, it is sufficient to use a resin that has poor adhesion to the resin film for plastic film. Resins with poor adhesion to each other are selected, for example, by comparing the critical surface tensions of plastics.

According to the findings of the present inventors, a laminate having good releasability can be obtained by selecting a plastic having a critical surface tension (see rat difference 1 Table 1) of 4.0 or more.

(The following is a blank space) Table 1 For example, from Table 1, combinations such as polypropylene/polyester, polypropylene/polystyrene, polyethylene/polyvinylidene fluoride, and polypropylene/polyvinylidene fluoride are desirable. In the case of stretching after laminating Kyo et al., it is necessary to consider and combine conditions such as stretching temperature, stretching ratio, heat treatment temperature, etc. in addition to critical surface tension.

The inorganic filler added to the laminating resin is a powdery mineral filler, such as calcium carbonate, basic magnesium carbonate, calcium silicate, magnesium silicate, aluminum hydroxide, magnesium hydroxide, It is a powder of inorganic substances such as calcium oxide, magnesium oxide, titanium oxide, clay, and talc that can be dispersed in plastics, and these can be used alone or in combination with 2f! ! It may be a mixture of i or more.

The average particle size of the inorganic filler used in the present invention is not particularly limited, but it is preferably selected from the range of 0.1 to 20μ. To prepare the resin composition, surface treatment agents such as surfactants, metal stones, and higher fatty acids are added, and if necessary, heat stabilizers, light stabilizers, pigments, etc. are further added. The melt-kneading may be carried out using a known method such as a Banbury extruder, a Banbury extruder, a roll extruder, a plastic extruder, or an extruder.

At this time, it is sufficient that the inorganic filler is contained in the composition in an amount of 0.1% by weight or more, and in the case of stretching after coating and lamination, the amount of the inorganic filler is preferably 60% by weight or less since stretchability is inhibited. More preferably, the content may be adjusted to 0.5 to 30% by weight.

For lamination, an appropriate method is taken depending on the shape of the plastic molded body used, the presence or absence of stretching, etc., but it is a method of extruding the plastic material of the film and the me for lamination in a state in which they are melted and adhered in a die. It is also possible to extrude the plastic material into a film onto a laminated resin film extruded from another extruder, and then roll it into tight contact with a rolling roll. Further, when a thin film is to be obtained, it can be obtained by stretching the laminated film in a uniaxial or biaxial direction and then peeling off each layer.

The laminating resin is laminated on at least one side of the plastic material, and can be laminated on both sides depending on the purpose.

Furthermore, when laminating, the surface of the plastic material that comes into contact with the 11i1WIJ resin needs to be in a molten state.

The molten state refers to a state in which the plastic material has plasticity, and in the case of non-grade resins, it refers to a state at or above the glass transition point.

Note that although the present invention is suitable for forming thin films, there is no limit to the thickness of the film, and it can also be applied to thick films. Therefore, the film of the present invention also includes thick-walled materials commonly referred to as sheets.

The laminated film obtained by these methods undergoes a step of being vapor-deposited and wound up while being peeled off, a step of rolling it up into a thin strip for use in a capacitor, and a step of winding it around a capacitor element using a winding machine. Stable production was possible without the occurrence of wrinkles in the processing steps such as the stripping process. Furthermore, the dielectric breakdown voltage of the obtained plastic molded article was also greatly improved.

The present invention will be explained in more detail with reference to Examples below.

Examples 1 to 4 Calcium carbonate "White Seal WS-tool" manufactured by Takehara Chemical Co., Ltd. with an average particle size of 5 μ and polypropylene manufactured by Mitsubishi Yuka Co., Ltd. (melt flow v-s, s?/l.

) were melt-kneaded in a Banbury mixer, and pelletized thermoplastic resin compositions having a calcium carbonate content of 0.5% by weight, 5% by weight, and 20% by weight were obtained using a pelletizer. Further, in the same manner, a composition having a calcium carbonate content of 5 weight range was obtained using Takehara Chemical Co., Ltd.'s calcium carbonate [White Seal WS-3KJ] having an average particle size of 1 μm.

Next, the above composition was transferred to a 658 extruder, and the above composition was transferred to a 30F extruder using Pennwalt Co., Ltd.
Supply each den 1. Then, the above composition was applied to both surfaces of the structure so that each layer had a thickness of 50/10/50 g to form a 31-structure.

This was axially stretched at 120° C.'r: 5 times to obtain three 11 il J11 stretched products each having a thickness of 10/2/1 (1 μm).

In the same manner, a three-layer structure containing no calcium carbonate in the resin of Product 11 and a stretched product thereof were obtained. In addition, the coating layer and the plastic molded body (PVI) F have an average particle size of 5 μm.
A three-layer stretched product containing 5% by weight of the above-mentioned inorganic filler was obtained.

Claims (1)

[Claims] A laminated film is formed by adhering a plastic material of the film and a resin containing an inorganic filler while at least the adhesion side surface of the plastic material is in a molten state, and then this is peeled off. Improved method of manufacturing plastic film.