JP7633875B2 - Zipper tape, bag with zipper tape and method of manufacturing same - Google Patents

Description

The present invention relates to zipper tapes for bags used mainly for food packaging, pharmaceutical packaging, miscellaneous goods packaging, etc., bags with zipper tapes, and methods for manufacturing the same.

Traditionally, bags used for various purposes such as food packaging, pharmaceutical packaging, and miscellaneous goods packaging are widely equipped with zipper tape at the opening, making them openable and closable.

The zipper tape comprises a pair of base parts made of synthetic resin, a pair of female claw bodies integrally protruding from the surface of one of the base parts, and a male claw body integrally protruding from the other base part and inserted between the female claw bodies, so that the female claw bodies and the male claw bodies can be detachably engaged with each other.

This zipper tape is fixed to the inside of the opening of the bag by welding the sealing layer laminated on the back side (film side) of the base to the inside of the film that makes up the bag.

In addition to sealing the bag, this zipper tape also presses both ends at high temperature (hereafter referred to as "zipper crushing") to integrate both ends of the zipper with the sealed portion of the bag.

On the other hand, this type of zipper tape has also been developed to shorten the welding time and improve productivity and appearance by using a low-melting point resin for the sealing layer (see, for example, Patent Document 1).

JP 2003-212249 A

However, in the conventional technology described above, if the film constituting the bag is a laminate film using aluminum film, when attempting to press both ends of the zipper tape at high temperature for a short period of time during the zipper crushing process, the aluminum film may be pressed by the zipper tape and crack, which may impair the sealability or appearance.

Therefore, with conventional zipper tapes, even if the time required for welding to the film was shortened by using a low-melting-point resin for the sealing layer, the zipper still required time to be crushed, and there was a problem in that productivity could not be improved.

In view of these conventional problems, the present invention aims to provide a zipper tape, a bag body with zipper tape, and a manufacturing method thereof that can shorten the time required for welding to the film that constitutes the bag body and for crushing the zipper, thereby improving productivity.

The feature of the invention described in claim 1 for solving the above-mentioned conventional problems is that the zipper tape includes a female claw member having a pair of female claw bodies protruding from the surface of a tape-shaped base portion, and a male claw member having a male claw body protruding from the surface of the tape-shaped base portion and inserted between the female claw bodies, the female claw member and the male claw member are formed from a low-melting point synthetic resin for a zipper containing 50 mass % or more of a metallocene-based polypropylene having an MFR of 5.0 g/10 min or more and a melting peak temperature of 130° C. or less, the base portion has a multilayer structure in which a seal layer to be welded to a film is laminated on the back surface side of the base portion main body, the seal layer is formed from a synthetic resin for sealing having a resin composition different from that of the low-melting point synthetic resin for the zipper, and the low-melting point synthetic resin for the zipper and the synthetic resin for sealing contain a common resin having a melting point of less than 100° C. in common to each other .

The invention described in claim 2 is characterized in that, in addition to the configuration of claim 1, the low melting point synthetic resin for the chuck contains 15 mass % or more of a metallocene-based propylene-α-olefin copolymer.

The invention as set forth in claim 3 is characterized in that, in addition to the features of claim 1 , the common resin is a resin using a metallocene catalyst.

The feature of the invention described in claim 4 is that in addition to the configuration of any one of claims 1 to 3 , both female claw bodies each have a hook support part having a mountain-shaped or arc-shaped cross section that bulges outward, and a hook part that extends inward from the tip of the hook support part, and the apex of the mountain-shaped or arc-shaped cross section of the hook support part is located on the tip side from the middle of the overall height.

The invention as set forth in claim 5 is characterized in that the bag body with zipper tape is provided with the zipper tape as set forth in any one of claims 1 to 4 .

The sixth aspect of the present invention is characterized in that, in addition to the configuration of the fifth aspect , the film constituting the bag body is a laminate film having an aluminum film layer.

The invention according to claim 7 is characterized in that a zipper tape comprising a female claw member having a pair of female claw bodies protruding from the surface of a tape-shaped base portion and a male claw member having a male claw body protruding from the surface of the tape-shaped base portion and inserted between the female claw bodies is disposed between a pair of films facing each other, the base portion is welded to the films, at least both side edges of the two films are pressed at a high temperature to weld them, and both ends of the zipper tape are crushed to be integrated with the films, in a manufacturing method for a bag with a zipper tape, The member is formed from a low-melting point synthetic resin for a chuck containing 50 mass % or more of a metallocene-based polypropylene having an MFR of 5.0 g/10 min or more and a melting peak temperature of 130° C. or less , and the base portion has a multilayer structure in which a sealing layer to be welded to the film is laminated on the back side of the base portion main body, the sealing layer being formed from a synthetic resin for a seal having a resin composition different from that of the low-melting point synthetic resin for the chuck, and the low-melting point synthetic resin for the chuck and the synthetic resin for a seal contain a common resin having a common melting point of less than 100° C.

The invention described in claim 8 is characterized in that, in addition to the configuration of claim 7 , the low melting point synthetic resin for the chuck contains 15 mass % or more of a metallocene-based propylene-α-olefin copolymer.

The invention as set forth in claim 9 is characterized in that, in addition to the features of claim 7 , the common resin is a resin using a metallocene catalyst.

The invention described in claim 10 is characterized in that, in addition to the configuration of any one of claims 7 to 9 , each of the female claw bodies has a hook support portion having an outwardly bulging mountain-shaped or arc-shaped cross section, and a hook portion extending inward from the tip of the hook support portion, and the apex of the mountain-shaped or arc-shaped cross section of the hook support portion is located on the tip side of the middle of the overall height.

The zipper tape of the present invention, by being provided with the configurations of claims 1 to 3, can lower the zipper crushing temperature and shorten the zipper crushing time, and can also be used in cases where the zipper tape is to be welded to a laminate film that uses an aluminum film.

In addition, by providing the configuration of claim 4 in the present invention, the chuck can be crushed smoothly.

Furthermore, by providing the configurations of claims 5 and 6 in the present invention, the zipper tape can be attached to the bag body in an appropriate manner and the appearance can be improved.

Furthermore, by providing the configurations of claims 7 to 10 in the present invention, the chuck crushing temperature can be lowered and the chuck crushing time can be shortened, making it possible to handle cases where an aluminum film is used for welding to a laminate film.

1 is a front view showing a bag with a zipper tape according to the present invention. FIG. 2 is an enlarged cross-sectional view showing a zipper tape portion according to the present invention in FIG. 1.

Next, an embodiment of the zipper tape according to the present invention and a bag body with zipper tape using the same will be described based on the embodiment shown in Figures 1 and 2. In the figures, reference numeral 1 denotes a bag body with zipper tape.

As shown in FIG. 1, the bag with zipper tape 1 comprises a bag-shaped main body 2 that is open on one side and a zipper tape 3 provided at the opening of the main body 2, and can be opened and closed by the zipper tape 3.

The bag body 2 is made of a pair of films 4, 5 made of synthetic resin that face each other, and is formed into a bag shape by providing a sealing portion 6 by heat welding three sides of both films 4, 5.

Films 4 and 5 are formed from a laminate film having an aluminum film.

The zipper tape 3 comprises a female claw member 9 having a pair of female claw bodies 8, 8 protruding from the surface of a tape-shaped base portion 7, and a male claw member 11 having a male claw body 10 protruding from the surface of the tape-shaped base portion 7 and inserted between the female claw bodies 8, 8. The base portion 7 is welded to the inside of the films 4, 5 and fixed to the inside of the openings of both films 4, 5, and the male claw body 10 and the female claw body 8, 8 are removably engaged with each other.

The male claw member 11 and female claw member 9 are integrally formed from a low-melting point synthetic resin for chucks, and can be melted at low temperatures.

The zipper tape 3, i.e., the male claw member 11 and the female claw member 9, are formed to a length approximately equal to the width of the films 4, 5 that constitute the bag body 2, and both ends of the zipper tape 3 are melted and crushed by being pressed with high pressure together with the sealing portion 6 of the bag body 2 (hereinafter referred to as zipper crushing), and are integrated with the sealing portion 6 of the films 4, 5.

The low-melting synthetic resin for the chuck contains 50% by mass or more of metallocene-based polypropylene with an MFR of 5.0 g/10 min or more and a melting peak temperature of 130°C or less, making it a low-melting resin.

The low-melting synthetic resin for the chuck contains 15% by mass or more of a metallocene-based propylene-α-olefin copolymer, and also contains a common resin made of a resin using a metallocene catalyst with a melting point of less than 100°C.

The base 7 is formed in the shape of a thin tape and has a multi-layer structure with a base body 7a made of a low-melting point synthetic resin for the chuck and a sealing layer 7b made of a sealing synthetic resin with a different resin composition from the low-melting point synthetic resin for the chuck, which is laminated on the back side of the base body 7a.

The synthetic resin for the seal has a resin composition with a lower melting point than the low melting point synthetic resin for the chuck, and contains a common resin made of a resin using a metallocene catalyst with a melting point of less than 100°C that is common to both the low melting point synthetic resin for the chuck and the low melting point synthetic resin for the chuck.

As shown in FIG. 2, the male claw body 10 has a male claw support part 13 that protrudes from the surface of the base part 7 and is continuous in the longitudinal direction of the base part 7, and an insertion hook part 14 that has an arrowhead-shaped cross section and is formed integrally with the tip of the male claw support part 13, and the male claw support part 13 and the insertion hook part 14 are formed in an arrow-shaped cross section.

The base ends of both female claw bodies 8, 8 are supported by the base part 7, and each has a hook support part 15 that is continuous in the longitudinal direction of the base part 7, and hook parts 16 that extend inward from the tips of the hook support parts 15, and the male claw body 10 is inserted between the hook parts 16, 16, so that the hook part 16 engages with the insertion hook part 14.

The hook support parts 15 each have a mountain-shaped or arc-shaped cross section that bulges outward, and the apex 15a of the mountain-shaped or arc-shaped cross section of the hook support part 15 is located at the midpoint of the overall height or further towards the tip, and the cross section consisting of both hook support parts 15 is such that the point where the distance w between both hook support parts 15, 15 is greatest is located at the midpoint m of the overall height h or slightly further towards the tip.

Next, we will explain the manufacturing method of this bag with zipper tape 1. Note that the same components as those in the above embodiment are given the same reference numerals and the explanation will be omitted.

The bag body 1 with zipper tape is manufactured by placing the zipper tape 3, which is made of engaging female claw members 9 and male claw members 11, between a pair of opposing films 4, 5, and welding the base portion 7 to the films 4, 5 by heating, and by pressing at least both side edges of both films 4, 5 at high temperature to weld them, and by crushing both ends of the zipper tape 3 to integrate them with the films 4, 5 and form the zipper crushed portions 17, 17 (zipper crushing process).

The base 7 has a multi-layer structure in which a sealing layer 7b is laminated on the back side of the base body 7a, and is welded to the films 4 and 5. The sealing layer 7b is made of a synthetic resin for sealing that has a different resin composition from the low-melting point synthetic resin for the chuck, so that the base 7 and the films 4 and 5 can be welded together in a short time.

In the zipper crushing process, the female claw member 9 and the male claw member 11 are made of a low-melting synthetic resin for zippers that contains 50% by mass or more of metallocene-based polypropylene with an MFR of 5.0 g/10 min or more and a melting peak temperature of 130°C or less. Therefore, when pressed at high temperatures, the end of the zipper tape 3 easily melts and is integrated with the films 4 and 5.

The hook support parts 15 each have a mountain-shaped or arc-shaped cross section that bulges outward, and the top of the mountain-shaped or arc-shaped cross section of the hook support part 15 is located at the midpoint of the overall height or slightly closer to the tip, and the cross section consisting of both hook support parts 15 is designed so that the point where the distance between both hook support parts 15, 15 is greatest is located at the midpoint of the overall height or slightly closer to the tip, making it easy for the male claw body 10 to be inserted between the two female claw bodies 8, 8.

In addition, when pressed at high temperatures by crushing the chuck, the low melting point synthetic resin used for the chuck melts easily, and since the top of the mountain-shaped cross section of the hook support part 15 is located at the middle of the overall height or slightly higher, the force acting in the overall height direction of the hook support part 15 due to pressing is dispersed horizontally, making the male claw body 10 and the female claw bodies 8, 8 easier to crush.

Therefore, the zipper crushing process can be performed at a low temperature in a short time, and even in the case of a laminate film with aluminum films 4 and 5, the zipper tape 3 easily melts and collapses, so excessive pressure is not applied to the aluminum film, and cracking of the films 4 and 5 can be prevented.

In the above embodiment, the films 4 and 5 are laminate films with an aluminum film, but the films may be made of other synthetic resins.

[0033] 1 Bag body with zipper tape 2 Bag body 3 Zipper tape 4, 5 Film 6 Sealing 7 Base part 8 Female claw body 9 Female claw member 10 Male claw body 11 Male claw member 13 Male claw support part 14 Insertion hook part 15 Hook support part 16 Hook part 17 Zipper crushing part

Claims (10)

A zipper tape comprising a female claw member having a pair of female claw bodies protruding from the surface of a tape-shaped base, and a male claw member having a male claw body protruding from the surface of the tape-shaped base and inserted between the female claw bodies,
the female claw member and the male claw member are formed of a low melting point synthetic resin for a zipper containing 50% by mass or more of a metallocene-based polypropylene having an MFR of 5.0 g/10 min or more and a melting peak temperature of 130° C. or less,
The base portion has a multi-layer structure in which a seal layer is laminated on the back side of the base portion main body and is welded to a film, and the seal layer is formed of a sealing synthetic resin having a resin composition different from that of the low-melting point synthetic resin for the chuck,
The zipper tape is characterized in that the low melting point synthetic resin for the zipper and the synthetic resin for the seal contain a common resin having a melting point of less than 100°C . The zipper tape according to claim 1, wherein the low melting point synthetic resin for the zipper contains 15% by mass or more of a metallocene-based propylene-α-olefin copolymer. 2. The zipper tape according to claim 1 , wherein the common resin is a resin using a metallocene catalyst. The zipper tape according to any one of claims 1 to 3, wherein each of the female claw bodies comprises a hook support part having an outwardly bulging mountain-shaped or arc-shaped cross section, and a hook part extending inward from a tip of the hook support part, and an apex of the mountain-shaped or arc-shaped cross section of the hook support part is located closer to the tip side than the middle of the overall height . A bag body with a zipper tape, comprising the zipper tape according to any one of claims 1 to 4 . 6. The bag with zipper tape according to claim 5 , wherein the film constituting the bag body is a laminate film having an aluminum film layer. A method for manufacturing a bag with a zipper tape, comprising: disposing a zipper tape between a pair of films facing each other; the zipper tape has a female claw member with a pair of female claw bodies protruding from the surface of a tape-shaped base; and a male claw member with a male claw body protruding from the surface of the tape-shaped base, the male claw body being inserted between the female claw bodies; welding the base to the films; pressing at least both side edges of the films at a high temperature to weld them; and crushing both ends of the zipper tape to integrate it with the films,
the female claw member and the male claw member are formed of a low melting point synthetic resin for a zipper containing 50% by mass or more of a metallocene-based polypropylene having an MFR of 5.0 g/10 min or more and a melting peak temperature of 130° C. or less,
the base portion has a multi-layer structure in which a seal layer is laminated on the back side of the base portion main body and is welded to the film, and the seal layer is formed of a sealing synthetic resin having a resin composition different from that of the low-melting point synthetic resin for the zipper,
The method for manufacturing a bag body with a zipper tape is characterized in that the low melting point synthetic resin for the zipper and the synthetic resin for the seal contain a common resin having a melting point of less than 100°C. 8. The method for producing a bag with a zipper tape according to claim 7 , wherein the low melting point synthetic resin for the zipper contains 15 mass % or more of a metallocene-based propylene-α-olefin copolymer. 8. The method for producing a bag with a zipper tape according to claim 7 , wherein the common resin is a resin using a metallocene catalyst. The method for manufacturing a bag body with a zipper tape according to any one of claims 7 to 9, wherein each of the female claw bodies has a hook support part having a mountain-shaped or arc-shaped cross section that bulges outward, and a hook part that extends inward from the tip of the hook support part, and the apex of the mountain-shaped or arc-shaped cross section of the hook support part is located on the tip side from the middle of the overall height .

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