JPS6035072A - Sheet-form adhesive - Google Patents

Abstract

PURPOSE:To provide a sheet-form adhesive suitable for use in bonding a decorative metallic plate to a resin molding, by forming one of adhesive layers provided on both sides of an insulating film by using an adhesive which is non- tacky at room temp. and providing a release paper through said adhesive layer. CONSTITUTION:An adhesive (any one which has adhesion of 500g/50mm. or below according to JIS Z-0237) which is non-tacky at room temp. and composed of a resin compsn. obtd. by mixing 100pts.wt. rosin resin with 100pts.wt. thermoplastic resin such as an ethylene/vinyl acetate copolymer, is used. An adhesive layer 2 which has a thickness of 20-200mu and is non-tacky at room temp., is provided on one side of an insulating film 1 such as a polyester film of 10-100mu in thickness, a release paper 3 is temporarily bonded to the layer 2 and a pressure- sensitive adhesive layer 4 is provided on the other side of said film to form a sheet-form adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sheet adhesive, which is used for bonding a metal decorative plate to a resin molded product.

In home appliances (for example, radio-cassette players, calculators, microcomputers, etc.), as shown in FIG.
After the electronic component 31 is set on the electronic component 31, a metal decorative plate (for example, an aluminum plate) 4' may be bonded. In this case, in order to ensure complete electrical insulation between the electronic component 3'' and the decorative plate 4'', it is necessary to provide an insulating film layer 5'' between the decorative plate 4'' and the resin insulator 1''. be.

Conventionally, in forming this insulating film layer 5', adhesive layers 52' were applied on both sides of an insulating film 51' as shown in FIG.
, 53' are provided, and one adhesive layer 52' is provided with a release paper 54'.
A sheet-like adhesive (handled in a rolled state) with a 53° angle is attached to the decorative plate original plate at 53° of the other adhesive layer, then punched into a predetermined shape using a press cutter, etc., and released from the punched plate with a release paper. After removing 54°,
The punched plate is adhered to the resin insulator and caulked.

However, when punching out a decorative plate original plate with a sheet of adhesive attached, it is necessary to leave a release paper attached to it to prevent it from sticking to the press cutter, and this release paper is soft. Therefore, there is a problem that the cut edge of the plate is markedly bulged or drooped.

An object of the present invention is to provide a sheet-like adhesive that allows the above-mentioned original plate to be punched out with the release paper removed, and that allows the above-described insulating film layer to be easily formed.

That is, the sheet-like adhesive according to the present invention has adhesive layers on both sides of an insulating film, and at least one adhesive layer is non-tacky at room temperature, and is 5009150 tm or less under JIS, Z, 0237. (including certain weak adhesive properties),
This configuration is characterized in that a release paper is provided on this room-temperature non-tacky adhesive layer.

The present invention will be explained below with reference to the drawings.

FIG. 3 shows a sheet adhesive according to the present invention.

In FIG. 3, 1 is an insulating film, which is a plastic film such as polyester, polypropylene, polyethylene polyvinyl chloride, rayon, Japanese paper, etc.
Electrically insulating resin (e.g. epoxy resin) on woven or non-woven fabric such as polypropylene, polyester, nylon, etc.
can be used, and its thickness is usually 10 μm.
~100μ. 2 is an adhesive layer provided on one side of the insulating film 1, and is non-adhesive at room temperature (JIS, Z,
It also has a weak tackiness of 20 to 500 mm under O'237 and 150 mm. The thickness of this adhesive layer 2 is usually 20~
It is 200μ. 3 is a release paper temporarily attached to the room temperature non-tacky adhesive layer 2, and is temporarily attached by welding with heat or a solvent or the like. Reference numeral 4 denotes an adhesive layer provided on the other side of the insulating film 1, and although an adhesive layer is usually used, the above-mentioned normal temperature non-tacky adhesive layer can also be used.

The sheet adhesive according to the present invention is stored in a rolled state,
It is transported and used by unwinding a predetermined length from this roll body. As will be described later, it is necessary that the release paper 3 be present on the room-temperature non-adhesive adhesive layer 2 side in this unrolled state. For this reason, the adhesion strength between the release paper 3 and the room temperature non-adhesive layer 2 is set to be greater than the adhesive strength between the release paper 3 and the adhesive layer 4. For example, glassine paper whose surfaces have been subjected to release treatment with silicone on both sides is used as the release paper, and the release paper and the room temperature non-adhesive adhesive layer are heat-fused at a controlled temperature.

The above-mentioned non-tacky adhesive 2 at room temperature includes: (1) thermoplastic resin such as ethylene-vinyl acetate copolymer, ionomer, polyamide, polyester, etc., and optionally hydrocarbon-based adhesive;
Resin-friendly products such as rosin-based, ester-rosin-based, xylene-based, terpene-based, phenol-based, terpene-phenol-based resins, ■Styrene-butadiene block copolymer, coumaron resin, styrene resin, xylene resin, phenol modified resin, etc. You can use a blend of.

It is desirable to adjust the softening point of these resins to 80° to 160°C. If it is lower than 80°C, it will become sticky at room temperature, and if it is higher than 160°C, high temperature will be required to develop adhesiveness, making it difficult to bond. . In the case of (1) above, the blending ratio should be 100 parts by weight or less per 100 parts by weight of the thermoplastic resin, and in the case of (2) above, the blending ratio should be 10 to 60 parts by weight per 100 parts by weight of the styrene-butadiene block copolymer. It is preferable to use parts by weight. This is because if the amount is more than this, it becomes sticky at room temperature and the adhesive properties at high temperatures are also deteriorated, and in the case of (2), if it is less than 10 parts by weight, the adhesive strength is significantly reduced. In order to improve non-stick properties at room temperature, an anti-blocking agent such as wax or fatty acid amide may be added in an amount of 10 parts by weight or less. If more than 10 parts by weight is added, the adhesive strength will be significantly reduced. In addition, anti-aging agents, fillers, stabilizers, pigments, cross-linking agents, etc. can be added as necessary.

For the adhesive layer 4, an acrylic-based, rubber-based, or silicone-based adhesive, or a nitrile-based, neoprene-based, ethylene-acetyl vinyl-based, or nylon-based adhesive can be used. .

The sheet adhesive of the present invention can be manufactured, for example, as follows.

Extrude the room-temperature non-tacky adhesive into a film using an extruder (the thickness is, for example, 50 μm), and then cover it with release paper (for example,
Place it on glassine paper (both sides of which have been surface-release treated with silicone) to obtain C) A. In addition, insulating films (e.g.
An adhesive solution (for example, acrylic) is applied to one side of a polyester film (50 μm thick), and the applied layer is heated to scatter the solvent to obtain sheet B.

The non-adhesive adhesive side of Sheet A is placed on the insulating film side of Sheet B, and the mating surfaces are fused using a heated roller.

The procedure for attaching a metal decorative plate to a resin molded body of a home appliance using the sheet adhesive of the present invention is as follows. (2) The sheet-like adhesive of the present invention is bonded to the original decorative plate in the adhesive layer 4 by pressing or the like. In this case, the release paper 3 acts as a cushion and contributes to preventing cracks in the adhesive layer. (2) Next, remove the release paper 3. ■Afterwards, punch out. In this case, since the release paper 3 has already been removed, it is possible to effectively prevent burrs and droop from occurring at the cut end. The size of the burrs and sag is also influenced by the thickness of the insulating film 1, the thickness of the adhesive layer 2, the thickness of the adhesive layer 4, etc. To prevent burrs and sag, the thickness of the insulating film 1 is 100μ or less. , the thickness of the adhesive layer 2 is 200
μ or less, the thickness of the adhesive layer 4 is 200 μ or less.

(2) Finally, the punched plate is thermocompression bonded to the resin molding, and the room temperature non-tacky adhesive 2 is fused to the resin molding. Instead of this heating and fusing, fusing can also be carried out by using a solvent.

As mentioned above, the sheet adhesive according to the present invention requires a release paper only to prevent blocking of the adhesive when the sheet adhesive is rolled, and is used for punching out after pasting it on a decorative plate. Sometimes the release paper can be removed, so
It can effectively prevent burrs and sag from occurring at the cut edges of the plate.Also, when the roll is unwound, there is a release paper on the non-adhesive adhesive layer side, so it can be pasted onto the decorative plate by pressing, etc. When bonding, the release paper can function as an effective cushion, and cracks in the adhesive layer due to press pressure can be effectively prevented.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing a fixing structure for a decorative plate in a home appliance, Fig. 2 is an explanatory diagram showing a sheet adhesive in this fixing structure, and Fig. 3 is an explanatory diagram showing a sheet adhesive according to the present invention. It is. In the figure, 1 is an insulating film, 2 is a non-adhesive or weakly adhesive layer at room temperature, 3 is a release paper, and 4 is an adhesive layer. 1 9-'7''? Bunch

Claims (2)

[Claims] (1) Adhesive layers are provided on both sides of the insulating film, and at least one adhesive layer is made non-adhesive at room temperature.
2.0237 (including weak tackiness of 500 g or less under 150 g), characterized in that the room temperature non-tack adhesive layer is provided with a release paper. (2) The other adhesive layer is an adhesive layer, and the adhesive strength between the non-adhesive or weakly adhesive adhesive layer at room temperature and the release paper is higher than the adhesive strength between the release paper and the other adhesive layer. A sheet adhesive according to claim 1.