JPH07145353A - Adhesive material - Google Patents

Abstract

PURPOSE:To obtain an adhesive material having a shape which can follow the surface contour of an adherend and capable being easily molded. CONSTITUTION:An adhesive material A is prepared by thermally expanding a laminate having an adhesive layer 2 on an least either surface of a thermally expandable support 1 so that the sectional shape may follow the shape of the surface of an adherend. Therefore, when adherends o different shapes are bonded with each other, excessive stress is not exerted on the adherends to make their stable bonding possible. The sectional shape of the adhesive material which follows the contour of the adherend can realized by a simple heating operation. No problem of appearance arises because of the good fit of the bonding material to the adherends.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive material for adhering and fixing a molded member for decoration, display, etc. on an adherend surface, and more specifically, it has a shape that follows a curved adherend surface. And an adhesive material that can be easily molded.

[0002]

2. Description of the Related Art Conventionally, as a method for attaching a molded member used for decoration, display, etc., a mechanical fixing method using screws, nails, bolts, etc., or a fixing method using an adhesive or an adhesive tape has been used. In particular, adhesion with an adhesive tape is used in many applications because of its simplicity. As shown in FIG. 3, for example, an adhesive tape used for such a purpose is a support 1 made of paper, nonwoven fabric, synthetic resin film, synthetic resin sheet / foam, rubber sheet / foam, etc.
The mainstream is composed of a pressure-sensitive adhesive layer 2 formed on both sides of the same and a pressure-sensitive adhesive layer 2 formed on both surfaces thereof, or a pressure-sensitive adhesive layer only. In particular, in order to bond two articles having different shapes, the adhesive tape is also required to have flexibility and shape-following property, and those having a foam as a support or those having only a pressure-sensitive adhesive are often used. There is. The adhesive tape having such flexibility absorbs the irregularities of the adherend and the distortion between the two articles and exhibits sufficient adhesive performance, and maintains high adhesiveness even after a long period of time after the adhesive fixing.

[0003]

However, for example, when a flat and highly rigid molding member is adhered to an adherend having a curved shape, the central portion of the molding member adheres to the adherend, The edges cannot fit together. Therefore, if the end portion of the molded member is also attempted to be brought into close contact with the adherend, the end portion of the molded member is forcedly applied with pressure to adhere the adherend. At that time, the pressure-sensitive adhesive tape is required to have adhesive performance capable of preventing a considerable repulsive stress caused by a reaction of forced adhesion. As a means of withstanding this repulsive stress, an adhesive tape having flexible physical properties is often used, and this also
The space cannot be filled up, for example, like the P part shown in FIG. 4, the adhesive tape cannot be peeled because it cannot withstand the repulsive stress even if it is once adhered. Has a problem that its appearance is not good.

In order to solve such a problem, it has been proposed that the adhesive tape is molded in advance so as to have a shape that matches the shape of the adherend so as to have a continuous change in the thickness direction. To mold with a shape that gives permanent distortion to
At present, it has not been put into practical use due to the problems that it requires excessive pressure, heating temperature and time, and it is necessary to prepare many molds to be used for it.

An object of the present invention is to solve the above problems and to provide an adhesive material having a shape which follows the surface shape of an adherend and which can be easily molded.

[0006]

The object of the present invention is to thermally expand a laminate having an adhesive layer on at least one surface of the present invention, that is, a heat-expandable support, and change its cross-sectional shape to the surface of an adherend. Adhesive material conforming to the shape of, wherein the support preferably has a thickness of 0.1 to 2.0 mm and a 25% compression hardness of 0.1 to 1.3 kg / cm ^2. 80 itself
It is achieved by one that expands by heating in the range of 150 ° C to 150 ° C.

Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1 is a schematic sectional view showing an embodiment of the present invention. In the figure, A is an adhesive material, and has a structure in which the adhesive layer 2 is formed on both surfaces of the support 1. In this embodiment, one surface of the adhesive material is formed in a concave shape so as to follow the surface shape of the adherend.

The adhesive material A of the present invention is characterized in that the support 1 having a thermal expansion property is heated and expanded so that its cross-sectional shape follows the surface shape of the adherend.

The support is not particularly limited as long as it has a thermal expansion property, but the thermal expansion property of this support is, for example, expansion of a foamable or non-foaming support base material by heating. It is obtained by including the component.

As the heat-expandable support, for example, a synthetic resin sheet containing a component that expands by heating such as a foaming agent (hereinafter referred to as heat-expandable component) (hereinafter referred to as heat-expandable component-containing synthetic resin sheet). Alternatively, a laminate of the heat-expandable component-containing synthetic resin sheet on a foam sheet such as a synthetic resin foam sheet or a synthetic rubber foam sheet is exemplified. As the synthetic resin for the heat-expandable component-containing synthetic resin sheet, thermoplastic resins, synthetic rubbers and the like are used, and specifically, polyolefin resins (for example, polyethylene, polypropylene, vinyl acetate or copolymers thereof, etc.) ), Synthetic rubbers (polychloroprene rubber, butyl rubber, nitrile rubber, silicone rubber, acrylic rubber,
Ethylene propylene terpolymer, etc.), polyurethane,
An acrylate polymer etc. are illustrated.

Examples of the heat-expandable component include hollow spheres (made of vinylidene chloride-acrylonitrile copolymer, methyl methacrylate polymer, acrylate polymer, etc.), sodium bicarbonate, ammonium carbonate, azobisformamide, azoisobutyronitrile. Examples thereof include foaming agents such as azodicarbonamide. Among them, azodicarbonamide having excellent foaming efficiency is preferably used.

As the synthetic resin for the synthetic resin foam sheet, a thermoplastic resin or the like is used, and specifically, a polyolefin resin (eg, polyethylene, polypropylene,
Vinyl acetate or copolymers thereof, etc.), polyurethanes, acrylate polymers, etc. are exemplified. Examples of the synthetic rubber foam sheet include polychloroprene rubber, butyl rubber, nitrile rubber, silicon rubber, acrylic rubber, ethylene propylene terpolymer, and the like.

As the synthetic resin for the foaming agent-containing synthetic resin sheet, the foamed sheet is preferably closed cells,
The foaming degree is preferably about 5 times.

The heat-expandable component is 80 to 150 ° C.,
It is desirable to select a material that expands by heating at about 90 to 110 ° C. When the heating temperature required for the expansion is 80 ° C. or higher, the degree of foaming is high and the foamed state is uniform, while when it is 150 ° C. or lower, the material is not deteriorated and the foamed state is as described above. It is preferable because it is likely to be uniform as in

The content of the heat-expandable component in the support 1 is 1 to 200 parts, preferably 30 to 70 parts, relative to 100 parts of the support base material. When the content of the heat-expandable component is 1 part or more, the thermal expansion property of the support 1 becomes good, while when it is 200 parts or less, the mechanical strength of the support 1 does not decrease, which is preferable. .

The thickness of the support 1 is 0.1 to 2.0 mm.
Is preferred. The thickness of this support 1 is 0.1 m
If it is m or more, the adhesive material can sufficiently absorb the clearance between the adherend and the performance as an adhesive material becomes good, while if it is 2.0 mm or less, when a molding member or the like is adhered. Since the adhesive material is inconspicuous, it is preferable in design. Further, since the adhesive material has good conformability to uneven surfaces and can secure a sufficient adhesive area even by light pressure bonding, the 25% compression hardness of the support 1 is 0.1.
It is preferably about 1.3 kg / cm ² . further,
In order to improve the followability of the adhesive material to the adherend and to make the adhesive strength of the adhesive material sufficient, the support 1 is
Internal strength 1kg / cm ² or more, elongation 100-1500%
It is preferable to have the following physical properties.

When the thermally expandable support 1 is crosslinked by electron beam irradiation or the like, thermal dimensional stability and interlayer strength are improved.

An adhesive layer 2 made of a pressure-sensitive adhesive composition is formed on both surfaces of the heat-expandable support 1. As the pressure-sensitive adhesive composition, a conventionally known rubber-based or acrylic-based adhesive composition can be used, but the initial adhesive strength is high, and various factors added after adhesive fixation, for example, repulsive stress, impact, It is preferable that it is difficult to deform and flow due to vibration and the like, and as such an adhesive composition, a copolymer of butyl acrylate and acrylic acid, a copolymer of 2-ethylhexyl acrylate and acrylic acid, etc. An acrylic resin is exemplified. In addition, the above-mentioned adhesive layer 2
Has a thickness of 0.03 to 0.15 mm, preferably 0.05
About 0.10 mm is desirable.

The adhesive material A of the present invention has a cross-sectional shape that follows the surface shape of the adherend as described above. This cross-sectional shape forms the adhesive layer 2 on the support 1. It is obtained by heating and expanding the laminated body.

As a method for heating and expanding the above-mentioned laminated body, the laminated body is set in a mold or the like having a shape suitable for the purpose and heated and expanded, or put into a hot air circulation type heating furnace to be heated and expanded. And the like.

As shown in FIG. 2, the adhesive material A shown in FIG. 1 is intended to adhere a planar molding member or the like to a convex adherend, and one surface is planar and the other surface is Although it is formed in a concave shape, the cross-sectional shape of the adhesive material of the present invention is not limited to such a shape, and can be arbitrarily selected according to the surface shape of the adherend, the molding member, etc. by selecting a mold or the like. Can be set to.

The adhesive material A is punched and used by a method such as a press work in which a die set to a shape suitable for the purpose is set in a press.

[0023]

In the above construction, the adhesive material follows the surface shape of the adherend by heating and expanding the heat-expandable support so that the adhesive material has a continuous change in the thickness direction. In addition, it is easy to form the adhesive material into the shape as described above.

[0024]

EXAMPLES Hereinafter, the present invention will be described more specifically by showing examples. Needless to say, the present invention is not limited to these examples. Example 1 100 parts of an acrylate polymer, 30 parts of hollow spheres (trade name Microsphere F30D; manufactured by Matsumoto Yushi Co., Ltd.), and an isocyanate cross-linking agent (on a surface of corona-treated polyethylene foam having a thickness of 0.2 mm) ( A composition comprising 5 parts (trade name: Coronate L; manufactured by Nippon Polyurethane Co., Ltd.) was applied to a thickness of 0.05 mm and dried to obtain a heat-expandable support. Then, an adhesive composition comprising 100 parts of the same acrylate polymer as described above and 2 parts of an isocyanate-based cross-linking agent was applied to both surfaces of this heat-expandable support and dried to form a pressure-sensitive adhesive layer having a thickness of 0.05 mm. Provided. Further, this laminated body was cut into 10 cm square pieces, set in a mold with a continuously changing thickness, heated at 120 ° C. for 20 seconds, and expanded so as to have a cross-sectional shape similar to that shown in FIG. Then, an adhesive material was obtained.

Example 2 100 parts of polychloroprene rubber, 50 parts of talc as a filler, 2 parts of sulfur as a vulcanizing agent and 3 parts of zinc oxide,
5 parts of Nocceller 22S (trade name, manufactured by Ouchi Shinko Kagaku Co., Ltd.) as a vulcanization aid and 20 parts of oil as a softening agent were further mixed, and an organic foaming agent (azodicarbonamide, trade name Celmic S; 15 parts by weight of Sankyo Kasei Co., Ltd.) was added to obtain a 0.4 mm-thick thermally expandable support. An adhesive composition comprising 100 parts of an acrylate polymer and 5 parts of an isocyanate cross-linking agent (Coronate L) was applied to both surfaces of this heat-expandable support and dried to a thickness of 0.05 mm.
The pressure sensitive adhesive layer of Thereafter, this laminate was cut in the same manner as in Example 1 above, heated and expanded to obtain an adhesive material.

Comparative Example 1 An adhesive composition comprising 100 parts of an acrylate polymer and 2 parts of an isocyanate cross-linking agent (Coronate L) was applied to both surfaces of a polyethylene foam having a thickness of 0.2 mm, the surface of which was corona treated, and dried. A pressure sensitive adhesive layer having a thickness of 0.05 mm was provided to obtain an adhesive material.

Comparative Example 2 An acrylic pressure-sensitive adhesive made of a copolymer of acrylic acid monomer and 2-ethylhexyl acrylate was 0.4 mm in thickness.
Was molded into a tape shape to obtain an adhesive material.

The adhesive material obtained in each of the above-mentioned Examples 1 and 2 has a plane portion having a length of 20 mm and a width of 1 mm.
The acrylic resin display panel having a thickness of 00 mm and a thickness of 2 mm was punched so as to have a shape similar to that of the display panel, and the flat portions were attached to the display panel. On the other hand, when a metal panel having a thickness of 5 mm was curved and the convex surface was used as an adherend, and the concave surface of each of the above-mentioned adhesive materials was attached to this, the adhesive materials all sufficiently follow the adherend. However, it was confirmed that the adhesive was stable even after being left for a long time.

Further, each of the adhesive materials obtained in Comparative Examples 1 and 2 was punched out in the same manner as above, and a display panel and a curved sheet were attached to both surfaces thereof, and both were attached for a while after attachment. However, after that, peeling occurred between the adhesive material and the curved sheet.

[0030]

According to the present invention, the heat-expandable support is heated and expanded to make the adhesive material have a continuous change in the thickness direction. Therefore, the adhesive material has a surface shape of the adherend. It is supposed to follow. Therefore, when bonding different shapes, it is possible to perform stable bonding without applying excessive stress to the bonding material. Further, the cross-sectional shape of the adhesive material, which follows the adherend, can be said to be industrially suitable because it can be obtained by a simple heating operation. Furthermore, since the above adhesive material fits to the adherend after being adhered to the adherend, there is no problem in appearance.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an adhesive material showing an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing an example in which a planar molding member is bonded and fixed to a convex adherend using the adhesive material of the present invention.

FIG. 3 is a schematic cross-sectional view showing an example of a conventional adhesive material.

FIG. 4 is a schematic cross-sectional view showing an example in which a planar molding member is bonded and fixed to a convex adherend using a conventional adhesive material.

[Explanation of symbols]

 1 Support 2 Adhesive Layer A Adhesive Material

Claims (3)

[Claims] 1. An adhesive material obtained by thermally expanding a laminate having an adhesive layer on at least one surface of a heat-expandable support so that its cross-sectional shape follows the shape of the surface of an adherend. 2. The support has a thickness of 0.1 to 2.0 mm, 2
The adhesive material according to claim 1, which has a 5% compression hardness of 0.1 to 1.3 kg / cm ² and expands by heating itself in the range of 80 ° C to 150 ° C. 3. The adhesive material according to claim 1, wherein the adhesive layer is made of an acrylic resin.