JP2581627Y2 - Tack sheet material for thermocompression bonding - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention relates to a tack sheet material for heating and pressure bonding, the purpose of which is to use for fixing and joining heater wires surrounded by a thermoplastic resin. An object of the present invention is to provide a heat-compression tack sheet material excellent in workability and workability.

(Prior art and its problems) Conventionally, when fixing an electric component (electric heating material) or the like, an adhesive sheet called a “tack sheet” has been used. In general, a paper base material such as kraft paper or high-quality paper, or a paper base material in which a thermoplastic resin such as polyethylene is laminated on at least one side has been used.

For this reason, in the heat-compression bonding step for fixing the heater wires formed by the hot melt adhesive layer provided on one side of the tack sheet base material and the thermoplastic resin, the paper base material of the release paper is thermally shrunk. This causes problems such as wrinkling, deformation (curl) and floating on the release paper, and large dimensional changes.

The generation of wrinkles and the like in these release papers has caused a reduction in the efficiency of the operation of attaching the pressure-sensitive adhesive layer temporarily adhered to the release paper to the adherend.

In addition, due to the moisture contained in the paper base material of the release paper, the pressure-sensitive adhesive layer temporarily adhered to the release paper causes foaming, and as a result, a phenomenon of a decrease in adhesive strength has been caused. .

Furthermore, in the case of a paper base material on which a thermoplastic resin such as polyethylene is laminated, the laminated thermoplastic resin causes foaming, or is melted by heat in a thermocompression bonding process, and is pressed with the thermoplastic resin by pressing. The adhesive layer to which the release paper is temporarily adhered may be fused, or the thermoplastic resin melted by this heat may be broken by pressure, and the exposed release paper base paper and the adhesive layer may come into contact with each other to cause this adhesion. There was a problem that the agent layer could not be peeled from the release paper.

Further, as shown in FIG. 2, the conventional tack sheet material (A) is deformed in the paper substrate (D) of the release paper in the heat-compression bonding step for bonding with the heater wire (B), and at the same time, the pressure-sensitive adhesive layer (C) is also deformed, and as a result, there is a problem that the adhesive strength of the pressure-sensitive adhesive layer (C) to the adherend is reduced.

In addition, a release film forming agent applied to release substrates such as paper and plastic films such as polyethylene (Japanese Patent Publication No.
5077) has been proposed, but when such a release film-forming agent is used, the adhesive strength does not decrease, but there is a problem that the sheet floats and wrinkles are generated during heat pressing.

In a tack sheet using a plastic film as a release substrate, a release agent layer is provided between the plastic film and the adhesive layer so that the temporarily adhered plastic film can be easily peeled off from the adhesive layer. However, if the release force from the plastic film release agent layer is too small at this time, the release agent layer does not follow the plastic film when the plastic film is released, and only the plastic film is peeled off. There is a problem that the agent layer remains on the tack sheet, and as a result, the tackiness of the tack sheet itself is reduced.

(Problems to be solved by the invention) In view of the above-mentioned conventional circumstances, in the industry, electric parts (electric heating materials),
In particular, it does not cause deformation or the like used in the heat-compression bonding step for fixing and joining the heater wires surrounded by the thermoplastic resin, and does not reduce its adhesion / adhesive strength. There has been a demand for the creation of a heat-compression tack sheet material that does not occasionally cause lifting or wrinkling of the sheet and that is safe and easy to handle.

(Means for Solving the Problems) In order to avoid the above-mentioned drawbacks, the present invention provides a sheet base made of a metal foil, a hot melt adhesive layer provided on one side of the sheet base, and a sheet base. A tack sheet material comprising an adhesive layer provided on the other surface of the material and a release sheet temporarily attached to the adhesive layer, wherein the release sheet is formed by peeling a release substrate made of a polyester or polyimide film. Heating characterized by comprising a release agent layer provided on at least the pressure-sensitive adhesive layer side of the base material, and a release force between the release base material and the release agent layer being 5 g / 50 mm or more. By providing a tack sheet material for crimping, the above-mentioned conventional problems were completely solved.

In other words, the present inventors consider that it is inappropriate or inconvenient to use a paper base as a release sheet for the tack sheet material used for thermocompression bonding, and to use a polyester or polyimide film instead of the paper base on this release paper. This led to the completion of this idea.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

1 (A), 1 (B), 1 (C), and 1 (D) are enlarged cross-sectional views of a tack sheet material for thermocompression bonding according to the present invention, where (1) is surrounded by a thermoplastic resin. Heater wire,
(2) is a hot melt adhesive layer, (3) is a substrate made of a metal foil which is a tack sheet substrate of the present invention,
(4) is a pressure-sensitive adhesive layer, (5) is a release agent layer applied to one side of a plastic film (6), and a film composed of the release agent layer (5) and a polyester or polyimide film as a release substrate. The release sheet is constituted from (6).

The thermocompression tack sheet material (7) is suitably used in a thermocompression bonding step for fixing and joining electric parts (electric heating material), particularly heater wires.

First, as shown in FIG. 1 (A), a hot melt adhesive layer (2) provided on one side of a metal foil (3) is brought into contact with a heater wire (1) surrounded by a thermoplastic resin such as vinyl chloride. Then, the heater wire (1) and the tack sheet material (7) are joined from the release substrate side made of the plastic film (6) using the thermocompression bonding body (H).

By this step, as shown in FIG. 1 (B), the heater wire (1) is fused with the hot melt adhesive layer (2), and the heater wire (1), the tack sheet material (7) and the adherend (8 ). ) Is completed.

After this joining, as shown in FIG. 1 (C), the release substrate (6) is removed together with the release agent layer (5) from the tack sheet substrate (7) , and then as shown in FIG. 1 (D). The adherend (9) is fixed to the pressure-sensitive adhesive layer (4).

The metal foil (3) used as the sheet substrate (3) in the above is not particularly limited, and an aluminum foil, a copper foil, a lead foil, or the like can be used as long as it has thermal conductivity.

When a metal foil having thermal conductivity is used for the tack sheet substrate (3) in the present invention, the thermal conductivity and heat retention to the hot melt adhesive layer (2) in contact with the heater wire (1) are improved. It is preferable because it increases.

As the hot melt adhesive layer (2), any of the well-known hot melt adhesives such as polyamide-based, polyester-based, ethylene-vinyl acetate copolymer-based, and polyolefin-based adhesives can be suitably used.

The hot-melt adhesive used in the present invention is mainly composed of thermoplastic resin, and has advantages such as fast curing property and short-time bonding work based on this property when assembling parts in electric products. It is widely used today.

Furthermore, since it can be bonded at a relatively low temperature and does not exhibit tackiness at room temperature, it is easy to handle, and is suitable for use in a thermocompression bonding process for fixing and joining a heater wire or the like surrounded by a thermoplastic resin. Hot melt adhesives are widely used as agents.

In the present invention, as the plastic film (6) which is a release substrate, a polyester or polyimide film which has excellent heat resistance and is not easily deformed and has a large release force, that is, a large adhesive force is used.

In the present invention, the reason why the peeling force of the plastic film (6) is set to 5 g / 50 mm or more is that the peeling force of the plastic film (6) having a peeling force of less than 5 g / 50 mm is small, and that the plastic film (6) together with the release agent layer (5) has When the film (6) is peeled off from the heat-compression tack sheet (7) , the release agent layer (5) does not follow the plastic film (6) but only the plastic film (6) is peeled off. ) Remains on the tack sheet (7) for thermocompression bonding.

At least the pressure-sensitive adhesive layer side of the plastic film (6) made of a polyester or polyimide film is subjected to a release treatment with a release agent to form a release agent layer (5).

Here, a silicone-based resin is particularly desirable as the release agent constituting the release agent layer (5), because it has excellent heat resistance.

The film (6) made of a polyester or polyimide film, which is a peeling substrate of the tack sheet material (7) for thermocompression bonding according to the present invention, does not cause foaming, deformation, etc., and as a result, at least one side of the plastic film (6) The applied release agent layer (5) can be treated at a high temperature, and the curing reaction of the silicone-based release agent is completed more completely. Therefore, unreacted components of the release agent layer (5) are reduced and the release agent layer (5) is stabilized. A release sheet having a release force can be obtained.

As the release agent for releasing at least the pressure-sensitive adhesive layer side of the film (6) made of a polyester or polyimide film, an addition-reaction-type or condensation-reaction-type silicone release agent is preferably used as described above.

Examples of the material of the pressure-sensitive adhesive layer (4) to which a release sheet having a film (6) made of a polyester or polyimide film as a release substrate is temporarily attached include acrylic resin, polyolefin resin, vinyl acetate resin, and rubber resin. For example, those commonly used for pressure-sensitive adhesive tapes can be used.

Hereinafter, the effect of the tack sheet material for thermocompression bonding according to the present invention will be further clarified using test examples and comparative examples.

(Test example) 20μm thick on one side of 50μm thick soft aluminum foil
A polyamide hot-melt adhesive is applied, and an acrylic pressure-sensitive adhesive layer having a thickness of 50 μm is provided on the other surface of the aluminum foil. A tack sheet material consisting of a 75 μm-thick polyester film having a release agent layer provided on the agent layer side with a silicone-based release agent was obtained.

Comparative Example A tack sheet material obtained in the same manner as in the above example was used as a comparative example except that a polyethylene laminated glassine paper base material was used as a release sheet.

First, a heater wire made of a vinyl chloride-based thermoplastic resin was placed in an arbitrary shape, and the hot melt adhesive layer provided on one side of the soft aluminum foil of the tack sheet material obtained in the above test examples and comparative examples was used as the heater wire. Place the tack sheet material on the heater wire so that it touches the wire.

Next, from the polyester film side to be the release sheet or the polyethylene laminated glassine paper substrate side, 50
The fixing and joining of the heater wire and the tack sheet material were performed under heating and pressure bonding conditions of 0.1 to 50 kg / cm ² for 0.1 to 10 minutes at 300 ° C.

The fixation / joining state was visually observed, and the wrinkle, deformation (curl), and floating of the release sheet, the presence or absence of foaming of the pressure-sensitive adhesive layer, and the fusion of the pressure-sensitive adhesive layer and the release sheet were each examined.

 Table 1 shows the results.

(Effects of the Invention) As described in detail above, the invention provides a sheet base made of a metal foil, a hot melt adhesive layer provided on one side of the sheet base, and a sheet base provided on the other side of the sheet base. Pressure-sensitive adhesive layer, and a tack sheet material comprising a release sheet temporarily attached to the pressure-sensitive adhesive layer, wherein the release sheet is a release substrate composed of a polyester or polyimide film and at least an adhesive layer of the release substrate And a release agent layer provided on the side, and a peeling force between the release substrate and the release agent layer is 5 g / 50 mm or more. When fixing and joining heater wires that are surrounded by an electric heating material, especially a thermoplastic resin, the temporarily attached release sheet may be wrinkled or deformed (curled).
-It becomes a tack sheet material for thermocompression bonding that does not easily cause the phenomenon of floating and has an effect of excellent dimensional stability.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view of the thermocompression tack sheet material according to the present invention in use, and FIG. 1 (A) is an enlarged cross-sectional view of a heater wire and a thermocompression tack sheet material being joined. (B) is an enlarged cross-sectional view after bonding by thermocompression bonding, (C) is an enlarged cross-sectional view when a release substrate and a release agent layer are removed, and (D) is adhesion of an adhesive layer. FIG. 2 is an enlarged cross-sectional view showing a state of adhesion to a body, and FIG. 2 is an enlarged cross-sectional view of a conventional technique after heating and pressure bonding of a heater wire and a tack sheet material. (1) ... heater wire, (2) ... hot melt adhesive layer (3) ... sheet substrate, (4) ... adhesive layer (5) ... release agent layer, (6) plastic film (Release substrate) (7) …… Tack sheet material for thermocompression bonding

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Naoki Matsuoka 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nippon Denko Co., Ltd. (56) References Real opening 1986-86442 (JP, U) Hei 3-70251 (JP, U) Japanese Patent Publication No. 64-5077 (JP, B2) (58) Field surveyed (Int. Cl. ⁶ , DB name) C09J 7/02

Claims (1)

(57) [Scope of request for utility model registration] 1. A sheet base made of a metal foil, a hot melt adhesive layer provided on one side of the sheet base, an adhesive layer provided on the other side of the sheet base, and an adhesive layer A release sheet temporarily attached to the release sheet, wherein the release sheet is a release substrate formed of a polyester or polyimide film and a release agent layer provided at least on the adhesive layer side of the release substrate. And a peeling force between the release substrate and the release agent layer of 5 g / 50 mm or more.