JP2005239759A - Film pressure-sensitive sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prepare a film pressure-sensitive sheet which effectively prevents tearing of a separator by a half-cut process of a substrate. <P>SOLUTION: This film pressure-sensitive sheet comprises the separator, a pressure-sensitive layer formed on the separator, and the substrate formed on the pressure-sensitive layer, where the separator comprises an unstretched polyolefin resin film and a support film for reinforcing the unstretched polyolefin resin film and the unstretched polyolefin resin film is arranged so that it contacts with the pressure-sensitive layer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a film pressure-sensitive adhesive sheet comprising a separator, a pressure-sensitive adhesive layer provided on the separator, and a base material provided on the pressure-sensitive adhesive layer.

  Conventionally, processing of film-like workpieces that require processing accuracy such as positional accuracy and dimensional accuracy, for example, processing into a flexible printed wiring board (hereinafter referred to as FPC) using a copper-clad laminated film (hereinafter referred to as CCL) For the purpose of reinforcing the workpiece and the like, a film pressure-sensitive adhesive sheet is used in the process of performing the process.

Explaining the case of using for the reinforcement of CCL using a film adhesive sheet, as shown in FIG. 2, a film adhesive sheet comprising a substrate 1, an adhesive layer 2 and a separator 3 is desired from the substrate 1 side by a Thomson blade type or the like. The notch 4 is cut into the shape of FIG. At this time, the necessary portion 5 is processed so as to be a half cut so that the notch 4 reaches a part of the adhesive layer 2 or the separator 3 without penetrating to the back surface of the film adhesive sheet. Without being isolated from the film pressure-sensitive adhesive sheet, the state of being supported by the separator 3 can still be maintained.
Thereafter, when the required portion 5 is adhered to the CCL, the unnecessary portion 6 is removed as shown in FIG. 3, and the CCL base material, that is, copper and polyimide is removed by a general attachment device such as a labeler. If it is a two-layer CCL7 with a film, it is adhered to the polyimide film 7b and used as a reinforcing material when the copper foil 7a is etched.

Here, it is desirable that the pressure-sensitive adhesive layer be easily peeled from the separator in the sticking step. Until now, a film having improved peelability has been obtained by applying a silicone release agent treatment to a polyester (for example, PET) film. (For example, there is a description that fluorine-modified silicone is used as a release agent for a separator in the embodiment of the following Patent Document 1). In recent years, FPC has been used for precision electronic devices such as personal computers, and the low molecular weight silicon compounds have shifted from silicon-based materials used for release agent treatment, resulting in problems that impede precision electronic devices and the like. Instead of a polyester film treated with a silicon release agent, biaxially oriented polypropylene (hereinafter referred to as OPP) has been used as a separator.
However, the OPP film is easier to tear than the polyester film, and when the cut reaches the OPP film used as a separator in the half cut, when holding the film adhesive sheet in a tensioned state or winding it, There was a problem that the separator was torn starting from the notch that reached the separator.
Such a problem that the separator of the film pressure-sensitive adhesive sheet tears is not limited to the case where the separator is used for reinforcement of the exemplified CCL, but is a problem common to a film pressure-sensitive adhesive sheet that performs half-cutting.
Japanese Unexamined Patent Publication No. 2000-256861

  The subject of this invention is providing the film adhesive sheet which can prevent effectively that the tear of the separator by the half cut process of a base material arises in view of the said problem.

  The present invention has been made to solve the above problems, and is a film pressure-sensitive adhesive sheet comprising a separator, a pressure-sensitive adhesive layer provided on the separator, and a base material provided on the pressure-sensitive adhesive layer, the separator Comprises a non-stretched polyolefin resin film and a support film for reinforcing the non-stretched polyolefin resin film, and the non-stretched polyolefin resin film is arranged so as to be in contact with the adhesive layer.

  The film adhesive sheet of the present invention is preferably characterized in that the non-stretched polyolefin resin film is a non-stretched polypropylene resin film.

  The film adhesive sheet of the present invention is preferably characterized in that the support film is a stretched polypropylene resin film.

  ADVANTAGE OF THE INVENTION According to this invention, the film adhesive sheet which can prevent effectively that the separator tears by the half-cut process of a base material can be provided. That is, by forming the cut into the separator by half-cutting up to the non-stretched polyolefin resin film, there is almost no risk of tearing the support film from the notch of the non-stretched polyolefin resin film. It is reduced.

  FIG. 1 shows an embodiment of the present invention. The film pressure-sensitive adhesive sheet of this embodiment includes a separator 3, a pressure-sensitive adhesive layer 2 provided on the separator 3, and a base material 1 provided on the pressure-sensitive adhesive layer 2.

  The material of the substrate 1 is not limited as long as it can protect and reinforce the workpiece. Polyolefin films such as polyethylene, polypropylene and polymethylpentene, polyester films such as polyethylene terephthalate and polybutylene terephthalate Examples thereof include a polyamide film such as nylon, a polyvinyl chloride film, a polyimide film, an acrylic resin film, a synthetic resin film such as a polycarbonate film, and a composite film using several types of synthetic resin films. In addition, if necessary, at least the adhesive layer side of the synthetic resin film may be subjected to surface roughening treatment such as corona discharge treatment, sandblast treatment, primer treatment, coupling agent treatment, etc. in order to increase the affinity with the adhesive layer 2. Chemical treatment may be performed. The base material 1 suitably used in the present invention includes a polyester (PET) film from the viewpoints of heat resistance, low heat shrinkage, appropriate bending hardness, and tensile strength. The polyester (PET) film used for the base material 1 The thickness is preferably 25 μm to 188 μm, more preferably 38 μm to 75 μm.

For the adhesive layer 2, acrylic, rubber, vinyl and urethane adhesives can be used, and the preferred adhesive layer 2 of the present invention is easy to adjust the adhesive force and has heat resistance. It is an acrylic adhesive.
The thickness of the adhesive layer 2 is preferably 5 μm to 30 μm, more preferably 7 μm to 10 μm.

  The separator 3 includes two layers of a non-stretched polyolefin resin film 3a and a support film 3b arranged so as to be in contact with the adhesive layer 2.

  The non-stretched polyolefin resin film 3a is preferably made of a non-stretched polypropylene resin in terms of easiness of laminating with a support film and heat resistance. The unstretched polypropylene resin may be a homopolymer or a copolymer with ethylene or α-olefin, but is preferably a homopolymer polypropylene resin. The thickness is preferably 10 μm to 30 μm.

  In the present specification, non-stretching means that a film that has been melted by heat is processed by extrusion, and is produced without using a stretching machine. When the tear strength based on JIS K 7128 is measured for the sheet to be obtained and the film before hot pressing, the stretched film gives a value different by 1.5 times or more, whereas the unstretched film has almost the same value. Since it is obtained, it can be easily distinguished.

  The non-stretched polyolefin resin film 3a is used when the film adhesive sheet is used, for example, when the film adhesive sheet is bonded to the base material 1 and the separator, or when the necessary part 5 is adhered by a labeler or the like. However, it is preferable to prevent the warp of the film pressure-sensitive adhesive sheet after being bonded at the time of manufacture and the deterioration of positional accuracy due to the elongation of the separator at the time of use. The thickness is preferably 20 μm to 40 μm. Furthermore, the material is preferably a polyolefin film from the viewpoint that the same material as the non-stretched polyolefin resin film 3a can be easily recycled.

  For the laminating process between the non-stretched polyolefin resin film 3a and the support film 3b, a general laminating process such as dry lamination or heat lamination can be applied.

The results of studies based on the above embodiment will be shown below.
<Example 1>
In this implementation, it implemented as shown in FIG. That is,
As the substrate 1, a 50 μm-thick polyethylene terephthalate resin film [Lumirror S10, Toray Industries, Inc.] subjected to corona treatment was used. Next, an acrylic pressure-sensitive adhesive was applied to the corona-treated surface and dried to form an 8 μm pressure-sensitive adhesive layer 2.
Separator 3 is a 25 μm thick polyethylene terephthalate resin film [Lumirror S10, Toray Industries, Inc.] as support film 3b, and a 20 μm thick CPP film [CP-S, Tosero Co., Ltd.] as an unstretched polyolefin resin film. Was laminated by dry lamination. At this time, the laminating adhesive 3c used for laminating the support film 3b and the non-stretched polyolefin resin film 3a had a thickness of 5 μm.
The separator 3 and the substrate 1 were laminated so that the support film 3b was in contact with the adhesive layer 2 to obtain a film adhesive sheet.
The evaluation is made by placing the film adhesive sheet on the lower die plate 11 and using the punching blade 12 from the substrate 1 side, and the distance between the die gap 21, that is, the tip of the punching blade 1 and the lower die plate 11 is 30 μm. A half-cut ribbon-like sample was applied so that a load of 500 g was applied, and the presence or absence of tearing was confirmed by visual observation.

<Example 2>
The film adhesive sheet prepared using an OPP film [OP U-0, Tosero Co., Ltd.] having a thickness of 20 μm and a support film 3 b of 20 μm in thickness is evaluated with a die gap 21 of 25 μm. The conditions are the same as in Example 1 except that.

<Example 3>
The same conditions as in Example 1 were used except that an OPP film [OP U-0, Tosero Co., Ltd.] having a thickness of 20 μm was used as the support film 3b and the die gap 21 was evaluated as 25 μm.

<Comparative example>
The conditions are the same as in Example 1 except that a 50 μm thick OPP film [OP U-1, Tosero Co., Ltd.] is used as the separator 3.

Table 1 shows the evaluation results.

  From Table 1, it can be seen that the present invention can provide a film pressure-sensitive adhesive sheet that can effectively prevent the separator from tearing due to the half-cutting step of the substrate.

Sectional drawing of the film adhesive sheet of one Embodiment. Sectional drawing of the conventional film adhesive sheet. The schematic diagram which shows the usage example of a film adhesive sheet. The schematic diagram which shows the state by which the film adhesive sheet of one Embodiment is half cut.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 Adhesive layer 3 Separator 3a Unstretched polyolefin resin film 3b Support body film

Claims (3)

A film pressure-sensitive adhesive sheet comprising a separator, a pressure-sensitive adhesive layer provided on the separator, and a base material provided on the pressure-sensitive adhesive layer,
The separator includes a non-stretched polyolefin resin film and a support film for reinforcing the non-stretched polyolefin resin film, and the non-stretched polyolefin resin film is disposed so as to be in contact with the adhesive layer. Film adhesive sheet. 2. The film pressure-sensitive adhesive sheet according to claim 1, wherein the non-stretched polyolefin resin film is a non-stretched polypropylene resin film. The film adhesive sheet according to claim 1 or 2, wherein the support film is a stretched polypropylene resin film.