Packaging bag and method for production thereof

Abstract

A packaging bag, characterized in that it comprises 2 sheets of resin film (2,2) having innermost layers (2a, 2a) made from one or more resins selected from the group consisting of a polyester, a polyamide, a polyacrylonitrile, a polycarbonate, a cyclic polyolefin and a polyfluoroethylene, the 2 sheets of resin film are arranged so that the innermost layers (2a, 2a) face each other in the inner sides thereof, and peripheral edge portions of the two resin films (2,2) are bound to each other via a peripheral edge adhesion section (3) comprising a thermoplastic resin capable of melting and adhering to the resin films (2, 2).

Description

TECHNICAL FIELD [0001] The present invention relates to a packaging bag and a method for producing the same. More specifically, the invention relates to a packaging bag which has flexibility and to which ingredients of a solution filled therein as a cotent are hardly adsorbed even when the packaging bag is used for liquid medicines, intravenous solutions and so on, and to the manufacturing method thereof. BACKGROUND ART [0002] Conventionally, as containers for preventing ingredients filled therein from adsorbing, injection molded or blow molded bottles are proposed which are made from resins that exhibit little adsorption such as cyclic polyolefins. [0003] However, such bottles are fragile due to the stiffness of cyclic polyolefins or the like. In addition, since the large amount of the resin used for making the bottles is required and the cyclic polyolefins or the like are very costly, the bottles formed from these resins become expensive. Furthermore, these bottles are not easy to...

AI Technical Summary

Benefits of technology

[0005] The object of the present invention is to solve the problems which usually non-adsorptive blow molded bottles and injection molded containers have on discarding and on utilizing because of their cost, and to provide a non-adsorptive packaging bag which is readily disposable and low-priced, as well as a method for producing the same.

[0010] When the peripheral adhesion section is constructed so that the two resin films are bonded or adhered by covering the outermost layers of the two resin films with the peripheral adhesion section formed from the thermoplastic resin, the peripheries of the two resin films are adhered by extruding the thermoplastic resin between the peripheries of the two resin films, or the peripheries of the two resin films are adhered by disposing the peripheral adhesion section previously formed from the thermoplastic resin between the two resin films to heat pressure bond, the two resin films can be easily adhered and the packaging bag having good adhesion property and strength can be obtained.

[0011] When the packaging bag has a port which is molded so that a part of the port is sealed or presealed by means of heat sealing or ultrasonic sealing and then the port is molded and integrated with the peripheral adhesion section, there is obtained the packaging bag having good adhesion property between the port and the packaging bag and having little liquid leakage. When the port is inserted between the two resin films to heat seal them and then the resin films and the port are firmly bonded by supplying the thermoplastic resin to the outermost layers of the resin films of the peripheral portion in which at least the port is set, there can be obtained good adhesion property.

[0012] In this case, when the resin which forms the outermost layers of the two resin films is the same resin or the same kind resin as the thermoplastic resin which forms the peripheral adhesion section, the adhesion property is more improved. When the resin which forms the innermost layers of the two resin films is the same resin or the same kind resin as the thermoplastic resin which forms the peripheral adhesion section, the adhesion property is also more improved. When at least a part of the port which comes contact with the contents is formed from the same resin or the same kind resin as the resin of the innermost layer of the packaging bag, the non-adsorbing effect is more improved.

[0016] By sealing the port and the resin films, and / or the two resin films with each other in advance, at least a part of them is adhered or pre-adhered to each other, thereby precisely fixing their positions each other when extruding a thermoplastic resin on the outermost layer of the resin film, and thus providing good adhesion. Furthermore, when at least a part of the two resin films are sealed in advance and then the thermoplastic resin is supplied to the outermost layers of the resin films to firmly bond the resin films, the liquid content is hardly entered between the resin films, thereby reducing the amount of adsorption even if the thermoplastic resin is one which is apt to adsorb ingredients of the contents, typically a polyolefin resin.

Problems solved by technology

However, such bottles are fragile due to the stiffness of cyclic polyolefins or the like.

In addition, since the large amount of the resin used for making the bottles is required and the cyclic polyolefins or the like are very costly, the bottles formed from these resins become expensive.

Furthermore, these bottles are not easy to crush on account of their stiffness, and thus become so bulky that these bottles cause the problem of discarding.

On the other hand, the cyclic polyolefins or the like themselves have inferior heat sealing properties, although they can be formed into films.

This causes the problem that a large bag having high heat sealing strength and the storage capacity of 300 ml or higher can not be produced.

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