JPH0641498A - Film adhesive and method for producing the same - Google Patents

Abstract

(57) [Summary] The present invention relates to a film adhesive suitable for adhering a sheet-like object such as paper or cloth, and a method for producing the same. [Purpose] Confidential postcards that adhere two confidential surfaces of postcard paper via two resin films sandwiched between the confidential surfaces have the trouble of coating a heat-sensitive adhesive on the surface of each resin film. Since the manufacturing cost increases, it is an object to reduce the manufacturing cost of the confidential postcard by eliminating the trouble of coating the resin film with the heat-sensitive adhesive. [Structure] The present invention is a film-like adhesive obtained by cooling and solidifying a liquid film made of a melt of a hot-melt adhesive as it is to form a single film. If pressure bonding is applied, the troublesome process of applying a heat-sensitive adhesive on the surface is unnecessary.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive used for adhering various objects, and more particularly to a film adhesive suitable for adhering the confidential surfaces of confidential postcards.

[0002]

2. Description of the Related Art Confidential postcards are available in Japanese Utility Model Sho 64-3649.
As described in Japanese Patent Publication No. 3 No. 3, in a state where two transparent resin films each coated with a heat-sensitive adhesive on one side are overlaid on the other side and pasted together with the heat-sensitive adhesive, the postcard paper is folded. It is sandwiched between two confidential surfaces facing each other, and each is thermocompression-bonded to the confidential surface by a heat-sensitive adhesive coated on one surface thereof, thereby completing the process. When opening this confidential postcard, the transparent resin films adhered with an anchoring force that is weaker than the anchoring force on the postcard paper peels off from each other, so that the confidential faces are peeled off, and each confidential face is transparent. The resin film is left to be adhered.

[0003]

However, the process of superposing two transparent resin films coated with a heat-sensitive adhesive on one side on the other side and pasting them together with a heat-sensitive adhesive is very troublesome. There is a drawback that the manufacturing cost of the postcard increases. Therefore, the present invention mainly aims to simplify the manufacturing process of the confidential postcard and reduce the manufacturing cost thereof.

[0004]

In order to solve this problem, the present invention provides a film-like adhesive which is unprecedented and a method for producing the same.
A hot-melt adhesive that forms a liquid film in a molten state is characterized by being cooled and solidified in the film state to form a film by itself, and the manufacturing method is a hot-melt adhesive. After the molten liquid of the above is applied to the surface of the synthetic resin sheet with a predetermined film thickness, the coating film is cooled and solidified, and then peeled off from the surface of the synthetic resin sheet to form a single film. It has a feature.

[0005]

If the film-like adhesive according to the present invention is sandwiched between the two confidential surfaces of the confidential postcard in a state of being superposed on the transparent resin film, it is possible to apply the heat-sensitive adhesive to the surface of the transparent resin film. Since the same function as the heat-sensitive adhesive is performed by the film-like adhesive, the troublesome process of previously coating the heat-sensitive adhesive on one side or the other side of the transparent resin film is unnecessary, and the manufacturing cost of the confidential postcard is reduced. Will be reduced.

[0006]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a diagram showing a method for producing a film adhesive according to the present invention, and FIG. 2 is a diagram showing an example of using the film adhesive.

The film-like adhesive 1 according to the present invention is, for example, as shown in FIG. 1, a melt R of a hot-melt type adhesive containing a polymer such as ethylene-vinyl acetate copolymer resin, polyamide or polyurethane as a main component. Is conveyed from the plate 2 to the coating roll 5 via the pickup roll 3 and the doctor roll 4, and the coating roll 5 and the backup roll 6 adjust the film thickness to be constant, while the feed rolls 7 and 8 are parallel to each other. It is coated on the surface of a synthetic resin sheet 9 composed of an endless polypropylene sheet or a polyester sheet that has been hung, and a coating film composed of a liquid film of the melt R is passed through the cooling device 10 as it is to be cooled and solidified, and then synthesized. A hot membrane that is mass-produced efficiently and inexpensively by a method of separating it from the surface of the resin sheet 9 and winding it on a drum 11 and forms a liquid film in a molten state. In the form of a film by itself by preparative adhesive it is still cooled and solidified the film state.

When this film adhesive 1 is used for manufacturing a confidential postcard, as shown in FIG. 2, the film adhesive is applied to both sides of a separate film 12 made of a transparent resin film such as a polypropylene film or a polyester film. 1 of these three films 1,
12 and 1 are passed between a pair of upper and lower feed rolls 13 and 14, and a pair of upper and lower heat rolls 19 and 20 are sandwiched between two adjacent confidential surfaces 17 and 18 of the postcard paper 16 of the confidential postcard 15. Heat and press through.

As a result, the two film-like adhesives 1 and 1 superposed on both sides of the separate film 12 are softened or melted, and both sides of the separate film 12 are respectively protected surfaces 17, 18 of the postcard paper 16. Then, the confidential postcard 15 is completed by thermocompression bonding, and the confidential surfaces 17 and 18 of which are pseudo-adhesively peeled off from each other. In other words, the film adhesive 1 made of a hot-melt adhesive has a stronger anchoring force on the postcard paper 16 forming the confidential surfaces 17 and 18 than the anchoring force on the resin film forming the separate film 12, and thus, When the surfaces 17 and 18 are peeled from each other, the surfaces 17 and 18 are not peeled from the surfaces of the confidential surfaces 17 and 18 and are about to be peeled from the surface of the separate film 12. Therefore, one or both of the confidential surfaces of the postcard paper 16 may be peeled off. A confidential postcard 15 that is opened by peeling from the separate film 12 is completed. Therefore, when opening the confidential postcard 15, the postcard paper 1
There is no damage such as damage to the confidential surfaces 17 and 18 of No. 6 or transfer of print from one confidential surface to the other confidential surface.

If a transparent resin film forming the separate film 12 is provided with a primer layer for improving the anchoring property of the adhesive or an anchor treatment such as a corona discharge treatment is applied only to one surface of the transparent film 12, the separate film 12 Since the anchoring force of the film adhesive 1 on one side and the other side is different in strength, when the confidential postcards 17 and 18 are peeled off and the confidential postcard 15 is opened, the separate film 12 is pressure-bonded to one confidential surface. As it is, the surface remains as a clear coat, and the separate film 12 does not become dust.

Further, when manufacturing the postcard 15 for confidential use, a heat-sensitive adhesive is applied between two transparent resin films and the films are bonded to each other as in the conventional case, or the heat-sensitive adhesive is applied to one surface of each film. Since the laborious process of coating the postcard is unnecessary, the productivity of the confidential postcard 15 is increased and the manufacturing cost thereof is significantly reduced.

The film adhesive 1 according to the present invention
Can be used not only for the production of confidential postcards but also for bonding various objects, and is particularly suitable for bonding sheet-shaped objects such as paper and cloth.

[0013]

As described above, when the film adhesive according to the present invention is used for producing a confidential postcard, a heat-sensitive adhesive is applied to the surface of the transparent resin film sandwiched between the confidential surfaces of the postcard paper as in the conventional case. The troublesome processing of coating is no longer necessary,
It has a very excellent effect that it can mass-produce confidential postcards at low cost. Also, since the film adhesive can be mass-produced at low cost by a simple method, the manufacturing cost of the confidential postcard can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a method for producing a film adhesive according to the present invention.

FIG. 2 is a diagram showing an example of use of the film adhesive.

[Explanation of symbols]

 1 ... Film adhesive R ... Hot melt adhesive melt 9 ... Synthetic resin sheet

Claims (2)

[Claims] 1. A film-like adhesive characterized in that a hot-melt type adhesive that forms a liquid film in a molten state is cooled and solidified in the film state to form a film by itself. 2. A hot melt adhesive melt (R) is applied to the surface of a synthetic resin sheet (9) to a predetermined film thickness, and the coating film is cooled and solidified. A method for producing a film-like adhesive, which comprises peeling from the surface of the sheet (9) to form a single film.