JP7416615B2 - Bag with zipper tape and manufacturing method thereof - Google Patents

Description

The present invention relates to a bag with zipper tape and a method for manufacturing the same.

In packaging bodies for foods and pharmaceutical products, the inner layer that comes into contact with the contents is often formed of a polyolefin resin film mainly composed of polyethylene or polypropylene, which has excellent safety and heat sealability. However, polyolefin resins have high permeability and adsorption properties for aroma components, so when used as an inner layer material, they may emit a plastic odor, and the product value may be impaired due to migration or adsorption of medicinal and aroma components in the contents. There are cases. Therefore, packages are known in which the inner layer is made of PET (polyethylene terephthalate), which is less likely to cause migration or adsorption of medicinal components and aromatic components of the contents.

For example, Patent Document 1 describes a zippered bag using PET as an inner layer. In the bag described in Patent Document 1, the inner layer is made of heat-sealable PET, and the zipper member is made of a mixed resin that is a blend of PET and polyester elastomer at a specific ratio, or a mixture of PET and polyethylene with a compatibilizer added. Made of resin. This allows the zipper member to be fused to the PET layer inside the bag, and provides flexibility to the zipper member to facilitate opening and closing.

Patent No. 6309925

However, when forming a zipper member with a mixed resin as described in Patent Document 1, the flexibility of the zipper member and the strength of the fusion bond with PET vary greatly depending on the blend ratio, so it is necessary to balance these. It wasn't easy. More specifically, if the PET ratio is high, the zipper member will lack flexibility and will be difficult to open and close, and if the PET ratio is low, the strength of the fusion bond with the PET inside the bag will be insufficient. . Therefore, in the zippered bag described in Patent Document 1, it is not easy to stabilize the quality related to the zipper member.

Therefore, the present invention provides a bag with a zipper tape that can reliably fuse a zipper tape to a bag whose inner layer includes PET while maintaining functionality as a zipper tape such as stable sealing performance and a suitable opening feeling. The purpose is to provide a method for producing the same.

According to an aspect of the present invention, there is provided a bag with a zipper tape, wherein the zipper tape is formed of a resin composition having polyolefin as a main polymer, and a pair of base strips and a pair of base strips are connected to each other. The first resin portion includes engaging portions that respectively protrude from opposing surfaces and are capable of engaging with each other, and the engaging portions of at least one pair of base strips are formed of a resin composition containing polyester as a main polymer. The bag has a polyester film having heat-sealing properties as a sealant film, and the polyester film is composed of styrene-( Consisting of a polyethylene terephthalate resin composition containing 0.1 to 3 parts by weight of methyl methacrylate-glycidyl methacrylate copolymer, 3 to 20 parts by weight of a softening agent, and 0.05 to 1.5 parts by weight of a molding aid. A bag with zipper tape is provided.
According to the above configuration, the engaging portion of the zipper tape is formed of a resin composition containing polyolefin as the main polymer, thereby maintaining functionality as a zipper tape such as stable sealing performance and a suitable opening feeling. be able to. Further, since the joint surface is formed of a resin composition containing polyester as a main polymer, the zipper tape can be reliably fused to the bag body whose sealant layer includes PET.

As explained above, according to the present invention, the zipper tape is reliably fused to the bag body whose inner layer includes PET while maintaining the functionality as a zipper tape such as stable sealing performance and a suitable opening feeling. A bag body with a zipper tape can be provided.

FIG. 1 is a plan view of a bag with a zipper tape according to a first embodiment of the present invention. FIG. 2 is a sectional view taken along line II-II of the bag with zipper tape shown in FIG. 1. FIG. It is a sectional view of the bag with the zipper tape concerning the 2nd embodiment of the present invention. FIG. 7 is a cross-sectional view of another example of the bag with zipper tape according to the second embodiment of the present invention. It is a sectional view of still another example of the bag with the zipper tape concerning the 2nd embodiment of the present invention. FIG. 7 is a sectional view of a bag with zipper tape according to a third embodiment of the present invention. FIG. 7 is a sectional view of a bag with a zipper tape according to a modification of the third embodiment. It is a sectional view of the bag with zipper tape concerning the 4th embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the schematic structure of the manufacturing apparatus used for the manufacturing method of the bag with zipper tape of this invention. 10 is an enlarged sectional view of the drum seal portion of the manufacturing apparatus shown in FIG. 9. FIG.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that, in this specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals and redundant explanation will be omitted.

In addition, in this specification, the main polymer means the most abundant component among the constituent components of each layer, but if each layer is composed of polymers of n components (n is an integer of 2 or more), it is 100/n%. The above means a component preferably containing 100/n x 1.2% or more. The main polymer can be analyzed by infrared spectroscopy, NMR, DSC, etc. It should be noted that impurities can be contained within the range that does not impair the effects of the present invention.

(First embodiment)
FIG. 1 is a plan view of a bag with a zipper tape according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II of the bag with a zipper tape shown in FIG. As shown in FIGS. 1 and 2, the zipper tape-equipped bag 1 according to the first embodiment includes a film 10 forming a bag having a first surface 11A and a second surface 11B, and a zipper tape 20. including.

The film 10 is formed of, for example, a single-layer or multi-layer thermoplastic resin. More specifically, film 10 may include layers formed of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), or polypropylene (PP). PP may be homopolypropylene (HPP), random polypropylene (RPP), or block polypropylene (BPP). When the film 10 is multilayer, biaxially oriented polypropylene (OPP), biaxially oriented polyethylene terephthalate (OPET), or biaxially oriented nylon (ONy) may be used for the front base material. The film 10 may also include a layer of an inorganic material formed by aluminum vapor deposition, aluminum foil lamination, or the like. In order to form the film 10 into multiple layers, dry lamination or sand lamination is used. In this embodiment, the sealant layer on the first surface 11A and the second surface 11B of the film 10, that is, the layer facing the zipper tape 20, is formed of a resin composition whose main polymer is heat-sealable PET (polyethylene terephthalate). Ru.

In this embodiment, the two films 10 are joined to each other at the bottom seal part 12 and the side seal part 13 to form a bag body having a first surface 11A and a second surface 11B. In this embodiment, the first surface 11A and the second surface 11B may be formed by folding back one film 10 at a portion corresponding to the side seal portion 13. Alternatively, a so-called gusset, which is a portion where the film 10 is folded inward, may be formed in a portion corresponding to the bottom seal portion 12 or the side seal portion 13 in the example of FIG. In this case, the gusset may be formed by the film 10 or by another film bonded to the film 10. Moreover, the bag body 1 with zipper tape may be a standing pouch that can be placed upright by forming a gusset at the bottom.

Further, in this embodiment, the bottom seal part 12 and the side seal part 13 are formed, but the top seal part is not formed, so that the opening part 14 of the bag body 1 with zipper tape is formed. In the embodiment, a top seal part is formed in addition to the bottom seal part 12 and the side seal part 13, and by cutting between the top seal part and the zipper tape 20, an opening is formed in the bag body 1 with the zipper tape after the fact. It may be possible to form 14. In yet another embodiment, the bag may be provided without the bottom seal portion 12, that is, without the zipper tape-attached bag 1 being sealed on the side opposite to the zipper tape 20. In this case, the bottom seal portion 12 is formed after the zipper tape-equipped bag 1 is filled with the contents. In addition to this, the present invention can be applied to bags of various known configurations and containers other than bags as long as the zipper tape is fused.

As shown in FIG. 2, the zipper tape 20 includes a first member 20A fused to the first surface 11A of the film 10 and a second member 20B fused to the second surface 11B. Each of the first member 20A and the second member 20B includes polyolefin portions 21A and 21B formed of a resin composition whose main polymer is polyolefin, adhesive resin layers 22A and 22B, and a resin composition whose main polymer is polyester. and polyester portions 23A and 23B formed of polyester. The polyolefin portions 21A, 21B include base strips 211A, 211B and engaging portions 212A, 212B protruding from mutually opposing surfaces of the base strips 211A, 211B, respectively. On the other hand, the polyester portions 23A, 23B cover the surfaces of the base strips 211A, 211B opposite to the engaging portions 212A, 212B, and bond surfaces 231A, 231B with the first surface 11A and second surface 11B of the film 10. form. The adhesive resin layers 22A, 22B are located between the polyolefin portions 21A, 21B and the polyester portions 23A, 23B, and bond these portions to each other. Such a zipper tape 20 is formed, for example, by coextruding resins of each part.

Here, the adhesive resin layers 22A and 22B are made of, for example, low-density polyethylene, linear low-density polyethylene, ethylene-propylene rubber, acid-modified polyolefin, epoxy group-containing monomer-ethylene copolymer, ethylene-(meth)acrylic acid ester. and dicarboxylic acid anhydride monomer, ethylene-vinyl acetate copolymer, ethylene-isobutyl acrylate copolymer, polyamide resin, thermoplastic polyester, polyvinyl acetate and its copolymer, dicyclopentadiene resin, etc. It is formed from adhesive resins such as alicyclic resins, styrene-based, polyester-based, and olefin-based elastomers, and one or a mixture of two or more of these resins. Among these resins, a mixture of low-density polyethylene, ethylene-propylene rubber, and alicyclic resin is used, with a mixing ratio of 55 to 70% low-density polyethylene, 15-30% ethylene-propylene rubber, and 15 to 30% alicyclic resin. is preferably used in a range of 5 to 20. By setting it as this range, sufficient adhesive strength between polyolefin and polyester can be obtained. Further, the thickness of the adhesive resin layer is not particularly limited, but it is preferably 10 μm to 200 μm.
By using these adhesive resins, higher interlayer bonding strength can be obtained between the polyolefin portions 21A, 21B and the polyester portions 23A, 23B. As a result, for example, when a bag 1 with a zipper tape as shown in FIG. It is possible to prevent the sealing performance of item 1 from being impaired, thereby preventing the contents from deteriorating and the bag's fragrance retention from decreasing.

In the zipper tape 20 as described above, the engaging portions 212A and 212B formed by the polyolefin portions 21A and 21B are capable of engaging with each other. In the example shown in FIG. 2, the engaging portion 212A has a male cross-sectional shape, the engaging portion 212B has a female cross-sectional shape, and these engaging portions 212A and 212B engage with each other. As a result, the zipper tape 20 is closed and the opening 14 of the zipper tape-equipped bag 1 is sealed. Note that the shapes of the engagement portions of various known zipper tapes, which are not limited to male and female types but are combinations of claw shapes, hook shapes, bump shapes, etc., may be applied to the engagement portions 212A and 212B in the above example. It is also possible to do so. Two or more sets of engaging portions may be provided in a pair of polyolefin portions. In either case, the engaging portions 212A, 212B are irregularly shaped portions that protrude from the base strips 211A, 211B having a substantially rectangular cross section. By maintaining the shape of such irregularly shaped portions, the opening 14 is reliably sealed when the engaging portions 212A and 212B are engaged, and an appropriate feeling of opening is created when the engagement is released. For this purpose, it is advantageous to form the engaging portions 212A, 212B in the polyolefin portions 21A, 21B whose main polymer is polyolefin. Here, the polyolefin resin used in the polyolefin portion includes polyethylene resins such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE), homopolypropylene (HPP), random polypropylene (RPP), and block polypropylene (BPP). ), polypropylene resins such as propylene-ethylene-butene one random terpolymer, and mixtures of these resins. Further, known additives such as stabilizers, antioxidants, lubricants, antistatic agents, colorants, etc. may be added to the polyolefin resin as necessary. Moreover, the same or different polyolefin resins can also be used for the polyolefin portion 21A and the polyolefin portion 21B.

On the other hand, when the sealant layers on the first surface 11A and the second surface 11B of the film 10 are formed of a resin composition containing heat-sealable PET as a main polymer as in this embodiment, polyolefin and heat-sealable PET It is not easy to directly fuse the polyolefin portions 21A, 21B forming the engaging portions 212A, 212B to the first surface 11A and the second surface 11B. Therefore, in this embodiment, the surfaces of the polyolefin portions 21A, 21B opposite to the engaging portions 212A, 212B are covered with the polyester portions 23A, 23B, and the joint surfaces 231A, 231B formed on the polyester portions 23A, 23B are The first surface 11A and the second surface 11B of the film 10 are fused. Since the fusion property between polyester and heat-sealable PET is high, the polyester portions 23A and 23B can be stably fused to the first surface 11A and the second surface 11B. The polyolefin parts 21A, B and the polyester parts 23A, 23B may be joined in any way, but in this embodiment, the adhesive resin layers 22A, 22B are used to join the polyolefin parts 21A, B and the polyester parts 23A, 23B. It connects between. Examples of the polyester resin used in the polyester portion include copolymerized polyesters such as polyester elastomers, and these include crystalline polyester resins and amorphous polyester resins. (registered trademark) (manufactured by Toyobo), Hytrel (registered trademark) (manufactured by DuPont-Toray), Arnitel (trade name, manufactured by DSM), Byron (registered trademark) (manufactured by Toyobo), Primalloy (registered trademark) (manufactured by Mitsubishi Chemical), etc. can be mentioned. Further, the thickness of the polyester portion is not particularly limited, but it is preferably 10 μm to 200 μm.

According to the first embodiment of the present invention as described above, the engaging portions 212A and 212B of the zipper tape 20 are formed of a resin composition containing polyolefin as a main polymer, thereby achieving stable sealing performance. While it is possible to maintain functionality as a zipper tape such as a feeling of opening and a moderate feeling of opening, the sealant layer is made of a film containing PET because the joint surfaces 231A and 231B are formed of a resin composition whose main polymer is polyester. The zipper tape 20 can be reliably fused to the first surface 11A and second surface 11B of 10.

(Second embodiment)
FIG. 3 is a sectional view of a bag with a zipper tape according to a second embodiment of the present invention. As shown in FIG. 3, the zipper tape-equipped bag 2 according to the second embodiment includes a film 10 and a zipper tape 40. Note that the configuration of the film 10 is the same as that of the first embodiment described above, and therefore, duplicate explanation will be omitted below.

As shown in FIG. 3, the zipper tape 40 includes a first member 40A fused to the first surface 11A of the film 10 and a second member 40B fused to the second surface 11B. Each of the first member 40A and the second member 40B includes polyolefin portions 21A, 21B, adhesive resin layers 42A, 42B, and polyester portions 43A, 43B. Note that the base strips 211A, 211B and the engaging portions 212A, 212B of the polyolefin portions 21A, 21B are the same as those in the first embodiment, so a redundant explanation will be omitted.

The polyester portions 43A, 43B are formed of a resin composition containing polyester as the main polymer, as in the first embodiment, and cover the surfaces of the base strips 211A, 211B opposite to the engaging portions 212A, 212B, Bonding surfaces 231A and 231B are formed. In addition, in this embodiment, the polyester portions 43A, 43B include rising portions 432A, 432B that cover the end surfaces 213A, 213B of the base strips 211A, 211B in the width direction of the zipper tape 40 (vertical direction in FIG. 3). Here, the rising portions 432A, 432B are portions where both widthwise ends of the cross-sectional shapes of the polyester portions 43A, 43B rise. In the illustrated example, the rising portions 432A, 432B cover the entirety of the end surfaces 213A, 213B, but they may cover at least part of the end surfaces 213A, 213B. Specifically, only the side close to the polyester portions 43A and 43B may be covered.

The adhesive resin layers 42A, 42B are formed of the same resin as in the first embodiment, but are not only formed on the surfaces of the base strips 211A, 211B opposite to the engaging portions 212A, 212B, but also on the end surfaces 213A, 213B. It also wraps around and is formed between the polyester parts 43A and 43B.

In this embodiment, in addition to obtaining the same effects as in the first embodiment, the polyester portions 43A and 43B cover the widthwise end surfaces 213A and 213B of the base strips 211A and 211B. , to prevent the formation of pinholes in the side seal portion 13 (see FIG. 1) where the first member 40A and the second member 40B of the zipper tape 40 are joined together with the first surface 11A and the second surface 11B of the film 10. I can do it.

More specifically, for example, when the side seal portion 13 is formed by heating and pressing two films and fusing them, the resin of the polyolefin portions 21A and 21B, which may include a volumetrically large engagement portion, is It melts and spreads where the side seal portion 13 and the zipper tape 40 overlap, the end surfaces 213A, 213B of the base strips 211A, 211B protrude from the polyester portion, and the polyolefin resin acts as a sealant on the first surface 11A or the second surface 11B. If it comes into contact with the resin of the layer, the polyolefin resin and the resin of the sealant layer have poor compatibility, so there is a possibility that the contacted portion will not be fused and a pinhole will be formed. In this embodiment, by covering the end surfaces 213A, 213B of the base strips 211A, 211B with the rising portions 432A, 432B of the polyester portions 43A, 43B, the resin of the polyolefin portions 21A, 21B and the first surface 11A or the second surface 11B The formation of pinholes due to contact with the resin of the sealant layer can be prevented. Note that even if the shapes are not called rising portions 432A, 432B, if the polyester portions 43A, 43B are formed in a shape capable of covering the end surfaces of the base strips 211A, 211B, similar shapes may be used. Effects can be obtained.

FIG. 4 is a sectional view of another example of the bag with zipper tape according to the second embodiment of the present invention. In the bag body 2A with zipper tape shown in FIG. 4, the width of the zipper tape 40 is comparable to that in the example shown in FIG. has been done. The width of the base strips 411A, 411B may be, for example, the same or narrower than the engaging portions 212A, 212B, as in the illustrated example. As a result, in the illustrated example, the polyester portions 43A, 43B form slab-like portions 433A, 433B that extend outward in the width direction from the end surfaces 213A, 213B of the base strips 411A, 411B.

In the illustrated example, the slab-like portions 433A, 433B cover the entire end surfaces 213A, 213B of the base strips 411A, 411B, but in other examples, the slab-like portions 433A, 433B cover part of the end surfaces 213A, 213B. Specifically, the slab-like portions 433A, 433B may not cover the end surfaces 213A, 213B. In this case, on the mutually opposing inner surfaces of the first member 40A and the second member 40B of the zipper tape 40, a step is formed between the base strips 411A, 411B and the slab-like portions 433A, 433B.

FIG. 5 is a cross-sectional view of still another example of the bag with zipper tape according to the second embodiment of the present invention. In the bag body 2B with zipper tape shown in FIG. 5, the zipper tape 40 includes two sets of polyolefin parts formed from a resin composition containing polyolefin as a main polymer, namely, polyolefin parts 41A, 41B and polyolefin parts 44A, 44B. . The polyolefin portions 44A, 44B are configured similarly to the polyolefin portions 41A, 41B, and include narrow base strips 441A, 441B, and engaging portions 442A, 442B configured similarly to the aforementioned engaging portions 212A, 212B. including. In the illustrated example, a so-called double zipper is configured by arranging the polyolefin portions 41A, 41B and the polyolefin portions 44A, 44B in parallel in the width direction of the zipper tape 40.

In the example shown, the base strips 411A, 411B, 441A, 441B of the polyolefin portions 41A, 41B, 44A, 44B are narrow, so that the polyester portions 43A, 43B are similar to the example of FIG. In addition to forming slab-like portions 433A and 433B on both ends in the width direction, slab-like portions are formed between base strip 411A and base strip 441A and between base strip 411B and base strip 441B, respectively. 434A and 434B are formed. In this specification, the slab-like portions (slab-like portions 433A, 433B and slab-like portions 434A, 434B) are formed by joining the polyester portions 43A, 43B to the polyolefin portion when the zipper tape 40 is viewed in the thickness direction. This refers to a portion where the zipper tape 40 is formed of slab (single plate) polyester portions 43A and 43B.

In the example described above with reference to FIG. 4 and FIG. By forming slab-like portions 433A, 433B, 434A, 434B formed by the polyester portions 43A, 43B between the plurality of polyolefin portions, it is possible to bond the polyolefin portions 41A, 41B, 44A, 44B and the polyester portions 43A, 43B. By minimizing the bonding area, it is possible to suppress deformation of the zipper tape 40 due to warping at the bonded portion.

Note that the double zipper as in the example described above with reference to FIG. 5 can be employed in other examples as well. For example, in the example shown in FIG. 4, a double zipper may be configured by two engaging portions 212A, 212B protruding from mutually opposing surfaces of base strips 411A, 411B, respectively. Further, in the example shown in FIGS. 2 and 3, a double zipper may be configured by two engaging portions 212A, 212B protruding from mutually opposing surfaces of base strips 211A, 211B, respectively. In other embodiments and modifications to be described later, a double zipper can also be constructed by having two engaging portions protrude from mutually opposing surfaces of the base strip. Alternatively, three or more engaging portions may each protrude from mutually opposing surfaces of the base strip.

(Third embodiment)
FIG. 6 is a sectional view of a bag with a zipper tape according to a third embodiment of the present invention. As shown in FIG. 6, the zipper tape-attached bag 3 according to the third embodiment includes a film 10 and a zipper tape 60. Note that the configuration of the film 10 is the same as that of the first embodiment described above, and therefore, duplicate explanation will be omitted below.

As shown in FIG. 6, the zipper tape 60 includes a first member 60A fused to the first surface 11A of the film 10 and a second member 60B fused to the second surface 11B. Each of the first member 60A and the second member 60B includes polyolefin portions 61A, 61B, adhesive resin layers 62A, 62B, and polyester portions 63A, 63B.

The polyolefin portions 61A, 61B are formed of a resin composition containing polyolefin as the main polymer, as in the first embodiment, and protrude from the base strips 611A, 611B and the mutually opposing surfaces of the base strips 611A, 611B, respectively. and engaging portions 212A and 212B. Note that the engaging portions 212A and 212B are the same as those in the first embodiment described above, so a redundant explanation will be omitted. The base strips 611A, 611B have a surface on the engaging portion 212A, 212B side and a surface on the opposite side, similarly to the first embodiment. In addition, in this embodiment, shapes corresponding to the return portions 633A, 633B of the polyester portions 63A, 63B, which will be described later, are provided at both ends of the base strips 611A, 611B in the width direction (vertical direction in FIG. 6) of the zipper tape 60. Step portions 614A and 614B are formed. In this embodiment, the stepped portions 614A, 614B are part of the surfaces of the base strips 611A, 611B on the engaging portions 212A, 212B side.

The polyester portions 63A, 63B are formed of a resin composition containing polyester as the main polymer, similar to the first embodiment, and cover the surfaces of the base strips 611A, 611B opposite to the engaging portions 212A, 212B, Bonding surfaces 231A and 231B are formed. In addition, the polyester portions 63A, 63B include raised portions 432A, 432B that cover the end surfaces 213A, 213B of the base strips 611A, 611B in the width direction of the zipper tape 60. Further, in this embodiment, the polyester portions 63A, 63B include barbs 633A, 633B that cover the steps 614A, 614B of the base strips 611A, 611B. Here, the turned parts 633A, 633B are such that the tips of the respective rising parts 432A, 432B, in which both ends in the width direction are raised in the cross-sectional shape of the polyester parts 63A, 63B, are located inside the base strips 611A, 611B in the width direction. This is a portion bent back toward the engaging portions 212A and 212B. As described above, in this embodiment, the stepped portions 614A, 614B are part of the surfaces of the base strips 611A, 611B on the engaging portions 212A, 212B side. Therefore, the return portions 633A, 633B partially cover the surfaces of the base strips 611A, 611B on the engaging portions 212A, 212B side. Note that in another example of this embodiment, the base strip has a substantially rectangular cross section without a stepped portion, and the turned portions 633A, 633B cover the entire flat surface of the base strip on the engaging portion side. May be covered.

The adhesive resin layers 62A, 62B are formed of the same resin as in the first embodiment, but are not only formed on the surfaces of the base strips 611A, 611B opposite to the engaging portions 212A, 212B, but also on the end surfaces 213A, 213B. , and the step portions 614A, 614B, and are formed between the polyester portions 63A, 63B.

In this embodiment, in addition to obtaining the same effects as in the second embodiment, the polyester portions 63A, 63B are added to the engaging portions in addition to the widthwise end surfaces 213A, 213B of the base strips 611A, 611B. A side seal portion where the first member 60A and the second member 60B of the zipper tape 60 are joined together with the first surface 11A and the second surface 11B of the film 10 by covering a part of the surfaces on the sides 212A and 212B. 13 (see FIG. 1) can be more reliably prevented from forming. More specifically, for example, when the side seal portion 13 is formed by heating and pressing two films and fusing them, the resin of the polyolefin portions 61A and 61B including the volumetrically large engagement portions is melted. , when the side seal portion 13 and the zipper tape 60 spread at the overlapped portion, go beyond the rising portions 432A, 432B, and come into contact with the resin of the sealant layer on the first surface 11A or the second surface 11B, the polyolefin resin and the resin of the sealant layer In this embodiment, the polyester portions 63A, 63B are connected to the engaging portions 212A of the base strips 611A, 611B by the return portions 633A, 633B. , 212B side, the fused return parts 633A, 633B cover the tips of the molten polyolefin parts 61A, 61B when they spread, and the resin of the polyolefin parts 61A, 61B and the first surface Formation of pinholes due to contact with the resin of the sealant layer 11A or the second surface 11B can be more reliably prevented. Note that even if the shape is not called the return portion 633A, 633B, the polyester portion 63A, has a shape that can similarly partially cover the surfaces of the base strips 211A, 211B on the engaging portions 212A, 212B side. 63B, similar effects can be obtained.

(Modified example)
FIG. 7 is a sectional view of a bag with a zipper tape according to a modification of the third embodiment. In the bag body 3A with zipper tape shown in FIG. 7, the return portions 633A, 633B of the polyester portions 63A, 63B are extended and reach the bases of the engaging portions 212A, 212B. In this case as well, the bases of the engaging portions 212A, 212B are not covered by the return portions 633A, 633B, so the polyester portions 63A, 63B partially cover the surfaces of the base strips 611A, 611B on the engaging portions 212A, 212B side. The covering is the same as the example described above with reference to FIG. However, in the example of FIG. 7, the step portions 614A and 614B are not formed.

In the second and third embodiments described above, it is possible to more reliably prevent the formation of pinholes when forming the side seal portions 13 on the zipper tape-attached bags 2 and 3. When the inner layer of the film 10 is formed of a resin composition containing PET, the bag with zipper tape has excellent fragrance retention, but the fragrance retention can be further improved by preventing the formation of pinholes. can. Note that even if there is no structure to prevent the formation of pinholes as in the first embodiment, significant pinholes may not be formed depending on the material and dimensions of the polyolefin portions 21A and 21B. Depending on the performance required of the bag body 1, the formation of pinholes may be tolerable. For the same reason, the second and third embodiments can be selected as appropriate depending on the necessity and degree of prevention of pinhole formation.

FIG. 8 is a sectional view of a bag with a zipper tape according to a fourth embodiment of the present invention. In the bag body 4 with zipper tape shown in FIG. 8, in the first portions 70A, 70B of the zipper tape 70, the engaging portions of the polyolefin portions 71A, 71B form a seal in which the male member 712A and the female member 712B are in surface contact with each other. It forms a mold engaging part. Such a sealed engagement portion is described in, for example, Japanese Patent Laid-Open No. 8-268445. In this embodiment, the sealing performance and pressure resistance of the zipper tape-attached bag body 4 can be improved by the sealing type engagement portion made up of the male member 712A and the female member 712B of the zipper tape 70. It should be noted that in the example shown in FIG. 8, the polyolefin portions 71A, 71B include narrow base strips 411A, 411B as in the example described above with reference to FIGS. 4 and 5; It is also possible to combine a non-narrow base strip with a sealed engagement similar to the example described with reference to it. Further, the structure of the film 10 and the resin used for the polyolefin parts 71A and 71B, the polyester part, and the adhesive resin layer are the same as in the first embodiment.

(Method for manufacturing a bag with zipper tape)
Next, regarding the manufacturing method of the bag with zipper tape of the present invention, the characteristic part of the process of welding the zipper tape and the film, and the manufacturing method of the bag with zipper tape including the same process will be explained together with an outline of the manufacturing equipment. I will explain.
FIG. 9 is a diagram showing a schematic configuration of the apparatus for manufacturing bags with zipper tape according to the embodiment of the present invention described above, and FIG. 10 is an enlarged sectional view of the drum seal part of the manufacturing apparatus shown in FIG. 9. It is. As shown in FIG. 9, the manufacturing apparatus 100 includes a supply section 101, a drum seal section 102, a conveyance section 103, and a bag making section 104.

The supply unit 101 includes film rolls 110A and 110B that supply a first surface 11A and a second surface 11B (hereinafter also referred to as films 11A and 11B) of the film 10, respectively, and a first member 20A and a second member of the zipper tape 20. 20B (hereinafter also referred to as zipper tapes 20A and 20B), a separation means 130 that separates the zipper tapes 20A and 20B pulled out from the tape take-up roll 120, and a conveying device 140. . The conveyance device 140 conveys the films 11A, 11B and the zipper tapes 20A, 20B in the longitudinal direction of each member, overlaps each other, and supplies the films to the drum seal section 102.

The drum seal section 102 includes a rotatable drum 151, a seal bar 153 having a sealing surface 154 facing a circumferential surface 152 of the drum 151, and an endless belt 155 inserted between the circumferential surface 152 and the sealing surface 154. including. The endless belt 155 is disposed at a portion facing the circumferential surface 152 of the drum 151 so as to be able to move in synchronization with the circumferential surface 152. Note that either or both of the drum 151 and the endless belt 155 may be driven by a drive device such as an electric motor. The films 11A, 11B and the zipper tapes 20A, 20B supplied from the supply unit 101 in a superimposed state are respectively wound around the circumferential surface 152 of a different drum 151, and the seals of the seal bar 153 that are in contact with the circumferential surface 152 are wound. Surface 154 heat-seals zipper tapes 20A and 20B to films 11A and 11B, respectively.

Here, in the example shown in FIG. 10, a groove 156 is formed on the circumferential surface 152 of the drum 151 and extends in the circumferential direction of the drum 151, that is, in the conveying direction of the films 11A, 11B and the zipper tapes 20A, 20B. (Only the first surface 11A and first member 20A side are shown). In the axial direction of the drum 151, the groove 156 is a position through which the engaging portion of the first member 20A passes when the first surface 11A and the first member 20A are wrapped around the circumferential surface 152 in a superimposed state. is formed. The width of the groove 156 is, for example, greater than the width of the engagement portion and less than the width of the base strip. By forming such a groove 156 and allowing the engaging portion to pass through the groove 156, interference between the engaging portion and the circumferential surface 152 of the drum 151 is prevented, and the films 11A, 11B and the zipper tapes 20A, 20B are By sandwiching between the sealing surface 154 and the circumferential surface 152 of the sealing bar 153 with equal pressure, stable joining can be achieved.

Referring again to FIG. 3, the transport section 103 includes a transport device 160 that transports the films 11A and 11B to which the zipper tapes 20A and 20B are attached to the bag making section 104. In the bag making section 104, a bag with a zipper tape is manufactured by performing processes such as bending, joining, and cutting the films 11A and 11B to which the zipper tapes 20A and 20B are attached. Note that various known configurations can be applied to the configuration of the bag making section 104, so a detailed explanation will be omitted. Regarding the configuration of the manufacturing apparatus 100, in addition to the above description, it is possible to apply various known configurations described in, for example, International Publication No. 2006/075644.
In the manufacturing process of the bag with zipper tape of the present invention, in order to thermally weld the film made of a heat-sealable polyester film as a sealant film and the zipper tape of the present invention, the above-mentioned rotatable It is possible to use a method of heat welding using a drum or a method of heat welding by heating and pressing with a flat seal bar, but in the method of heat welding using a rotatable drum, the zipper tape and film As the drum rotates with the flow, the zipper tape and film are fed without rubbing against other parts, so the resistance when feeding the zipper tape and film is reduced, and wrinkles that occur on the zipper tape and zipper This is preferable because wrinkles generated between the tape and the film can be suppressed.

The sealant film used in the zippered bag of the present invention is a polyester film having heat sealability.

This polyester film consists of 100 parts by weight of polyethylene terephthalate resin, 0.1 to 3 parts by weight of styrene-methyl(meth)acrylate-glycidyl methacrylate copolymer, 3 to 20 parts by weight of softening agent, and 0 parts by weight of molding aid. The film is made of a polyethylene terephthalate resin composition containing .05 to 1.5 parts by weight.

The intrinsic viscosity of the polyethylene terephthalate resin is preferably 0.6 to 0.8 dl/g, more preferably 0.6 to 0.7 dl/g, and still more preferably 0.6 to 0.65 dl/g. If it is less than 0.6 dl/g, the melt viscosity becomes insufficient and film formation tends to become unstable. On the other hand, if it exceeds 0.8 dl/g, heat sealability tends to be difficult to develop. Polyethylene terephthalate resins may be used alone or in combination of two or more. Note that the intrinsic viscosity is the viscosity measured by dissolving polyethylene terephthalate resin in a mixed solvent of phenol:tetrachloroethane=1:1 and using an Ubbelohde viscometer at 25°C. The polyethylene terephthalate resin may be used not only as a single resin but also as a combination of two or more types. It may also be a recycled resin recycled from used plastic bottles or the like.

The styrene-methyl (meth)acrylate-glycidyl methacrylate copolymer used in the present invention preferably has an epoxy value of 0.5 to 4.0 meq/g as measured by the method of ASTM-D1652. A more preferable epoxy value is 1.0 to 3.5 meq/g. If the epoxy value is less than 0.5 meq/g, sufficient melt viscosity for film formation and molding cannot be maintained, and the crystallinity of the film may not fall within the desired range and sufficient heat sealability may not be achieved. . On the other hand, if it exceeds 4.0 meq/g, recombination between polyethylene terephthalate molecules progresses excessively, which tends to cause problems such as frequent occurrence of gel foreign substances during film formation and molding.

Examples of styrene-methyl (meth)acrylate-glycidyl methacrylate copolymers are described in, for example, Japanese Patent Application Laid-open No. 2005-154690, and BASF Japan Co., Ltd.'s Joncryl (registered trademark), Toagosei Co., Ltd. Company's Alfon (registered trademark) and other products are commercially available. The styrene-methyl (meth)acrylate-glycidyl methacrylate copolymer may be used alone or in combination of two or more.

The softening material used in the present invention refers to a material that has an affinity for polyethylene terephthalate resin and is highly flexible. Specifically, ethylene-(meth)acrylic acid ester copolymers and polyesters other than polyethylene terephthalate may be used. Preferred examples of the former include ethylene-glycidyl methacrylate copolymer and ethylene-butyl acrylate. A preferred example of the latter is polybutylene terephthalate (PBT), a copolymer consisting of two or more units derived from an aromatic dicarboxylic acid such as terephthalic acid and a unit derived from a polyhydric alcohol having 1 to 10 carbon atoms. Examples include polyesters with reduced crystallinity, such as polymerized polyesters, terephthalic acid-ethylene glycol-1,4-cyclohexanedimethanol copolymers (PCTG), and copolymers of polyester hard components and polyether soft components. It will be done. These are commercially available products and can be used. Further, the polyester resin used in the polyester portion of the zipper tape of the zippered bag of the present invention can also be used as a softening material . In this case, it is preferable to use the same polyester resin as the polyester resin used for the polyester portion of the zipper tape as the softening material for the sealant film, since the zipper tape can be more reliably fused to the bag body. In addition, when transparency of the sealant is required, it is preferable to use a polyester other than polyethylene terephthalate as the softening material, because the film becomes cloudy when an ethylene-(meth)acrylic acid ester copolymer is used.

The molding aids used in the present invention include saturated and unsaturated fatty acids having about 10 to 20 carbon atoms such as stearic acid, lauric acid, ricinoleic acid, and octylic acid, and alkali metals such as lithium, magnesium, calcium, barium, and zinc. Metal salts with metals such as , alkaline earth metals and zinc group metals are preferred. Specifically, lithium stearate, magnesium stearate, calcium stearate, barium stearate, zinc stearate, calcium laurate, barium laurate, zinc laurate, barium ricinoleate, zinc ricinoleate, zinc octylate, etc. However, calcium stearate, which has excellent safety and hygiene properties, is particularly suitable as a packaging material for food and medical products.

In addition to the above, a dispersion aid may be added to the polyethylene terephthalate resin composition of the present invention. The dispersion aid is a compound that has the effect of moistening the surface of the particles of the forming aid and making the dispersion uniform. The dispersion aid is preferably a higher fatty acid ester having a polyfunctional epoxy group. Representative dispersing aids include epoxidized soybean oil and epoxidized linseed oil.

The heat-sealable polyester film of the present invention may further contain other substances. Specific examples of other substances include fillers such as calcium carbonate and talc, anti-blocking agents such as polymethyl methacrylate fine particles, and pigments.

The blending ratio of the polyethylene terephthalate resin composition in the present invention is 0.1 to 3 parts by weight of styrene-methyl(meth)acrylate-glycidyl methacrylate copolymer and 3 to 3 parts by weight of the softening agent to 100 parts by weight of the polyethylene terephthalate resin. 20 parts by weight, and 0.05 to 1.5 parts by weight of the molding aid.

In the polyethylene terephthalate resin composition of the present invention, the styrene-methyl (meth)acrylate-glycidyl methacrylate copolymer is contained in an amount of 0.1 to 3 parts by weight, preferably 0.3 to 3 parts by weight, based on 100 parts by weight of the polyethylene terephthalate resin. 2 parts by weight is blended. If the blending amount of the styrene-methyl (meth)acrylate-glycidyl methacrylate copolymer is less than 0.1 part by weight, the melt tension during melting of the polyethylene terephthalate resin composition will be insufficient, and bubbles will not be stable during blown film molding. First, in T-die casting film formation, neck-in becomes severe and the film formation is unstable. On the other hand, if the amount of the styrene-methyl (meth)acrylate-glycidyl methacrylate copolymer exceeds 3 parts by weight, the viscosity of the polyethylene terephthalate resin composition increases sharply when it is melted, making molding difficult.

In the polyethylene terephthalate resin composition, the softening agent is blended in an amount of 3 to 20 parts by weight per 100 parts by weight of the PET resin. If the blending amount of the softening agent is less than 3 parts by weight, the rigidity of the formed film may become high and sufficient product functionality may not be exhibited. On the other hand, if it exceeds 20 parts by weight, it is undesirable because it becomes excessively flexible and the stiffness of the film decreases significantly.

In the polyethylene terephthalate resin composition, the molding aid is blended in an amount of 0.05 to 1.5 parts by weight, preferably 0.1 to 1 part by weight, per 100 parts by weight of the polyethylene terephthalate resin. If the amount of the molding aid is less than 0.05 part by weight, the resin composition becomes sticky during molding, and resin lumps are likely to be formed, which impedes stable molding. On the other hand, if the amount of the molding aid exceeds 1.5 parts by weight, the resin compositions or the resin composition and the screw may slip during molding, making it difficult to stably supply the resin composition to the molding screw, which is not preferable. .
The present invention relates to a sealant film made of a specific polyethylene terephthalate resin composition that enables heat sealing at a lower temperature than before modification by converting the polyethylene terephthalate resin into a composition and modifying it. By combining the zipper tape with a zipper tape made of a combination of specific materials that allow adhesion, it is possible to provide a bag with a zipper tape that has low adsorption and excellent fragrance retention. Furthermore, by using a specific layer structure of the zipper tape, it is possible to provide a bag with a zipper tape that further improves fragrance retention by preventing the formation of pinholes in the bag with a zipper tape.
Hereinafter, the zippered bag of the present invention will be described in more detail based on Examples, but the present invention is not limited to the Examples illustrated below.

Example 1 The bag body 1 with a zipper tape according to the first embodiment of the present invention described above with reference to FIG. 2, and the bag body 2 with a zipper tape according to the second embodiment described with reference to FIG. Example 2, the bag 3 with zipper tape of the third embodiment described with reference to FIG. 6, Example 3, and the bag 4 with zipper tape of the fourth embodiment described with reference to FIG. As Example 4, styrene-methyl (meth)acrylate having an epoxy value of 3.5 meq/g measured by the method of ASTM-D1652 was used for 100 parts by weight of polyethylene terephthalate resin having an intrinsic viscosity of 0.70 dl/g. - 0.35 parts by weight of glycidyl methacrylate copolymer, 4 parts by weight of terephthalic acid-ethylene glycol-1,4-cyclohexanedimethanol copolymer having an intrinsic viscosity of 0.76 dl/g as a softening agent, and molding. Heat-sealability of a polyethylene terephthalate resin composition containing 0.1 parts by weight of calcium stearate as an auxiliary agent Heat-sealability of zipper tapes 20, 40, 60, and 70 for a sealant layer formed of a resin composition whose main polymer is PET , and the presence or absence of pinholes in the side seal portions 13 of the bags 1, 2, 3, and 4 with zipper tapes was evaluated. In the evaluation, as the film 10, a film was used in which a 20 μm thick sealant film, a 7 μm thick aluminum foil, and a 12 μm thick biaxially oriented polyethylene terephthalate film constituting the sealant layer were dry-laminated in this order with a urethane adhesive.

In the zipper tapes of Examples 1 to 4, the polyolefin portion was made of linear low-density polyethylene with a density of 915 kg/m3 and a melt flow rate of 4.0 g/min, and the adhesive resin layer was made of low-density polyethylene and ethylene. - Adhesive resin containing propylene rubber and alicyclic resin in a ratio of 63:23:14 (unit: wt%), crystalline polyester as material for the polyester part (Toyobo Co., Ltd. Byron SI-173 and GM-913) A 6:4 blend of These raw material compositions were extruded using an extruder at an extrusion temperature of 230° C., and then cooled with water to produce zipper tapes 20, 40, 60, and 70. In Example 1, the width of the base strip of the zipper tape is 7 mm, and the thicknesses of the polyester portion, adhesive layer, and base strip are 35 μm, 35 μm, and 175 μm, respectively. .

In addition, as a comparative example, the polyester portions 23A and 23B of the zipper tape 20 of the first embodiment were omitted, and a zipper tape composed of polyolefin portions 21A and 21B and adhesive resin layers 22A and 22B was made using the same raw material as above. It was produced using the composition and molding method, and was bonded to the same film 10 as in the first embodiment to form a bag with a zipper tape.

Table 1 shows the evaluation results of heat sealability and the presence or absence of pinholes in Examples 1 to 4 and Comparative Examples. The evaluation method is as follows.

(1) Heat-sealability Using a "thermal gradient tester" manufactured by Toyo Seiki Seisakusho Co., Ltd., a laminate film of PET #12/aluminum foil 7 μm/heat-sealable PET #20 (total thickness approximately 40 μm) was used to test Examples. The zipper tapes and laminate films of Examples 1 to 4 and Comparative Example were sealed at a sealing time of 1.0 seconds, a sealing pressure of 2.0 MPa, and a sealing temperature of 180° C. to obtain evaluation samples. Regarding this evaluation sample, the heat seal strength (N/15 mm) between the zipper tape and the laminate per width of 15 mm was measured using a "Digital Force Gauge" manufactured by Imada. In addition, the tensile speed at the time of seal strength measurement was 300 mm/min. In Table 1, cases where the heat seal strength is 15 (N/15 mm) or more and cases where it is less than 0.15 (N/15 mm) are shown as x.

(2) Presence or absence of pinholes Alcohol colored with ink was sealed in the bags with zipper tape of Examples 1 to 4 and Comparative Example, and the presence or absence of pinholes in the side seal portion 13 was evaluated. In Table 1, the case where colored alcohol did not leak from the side seal portion is indicated by ◯, and the case where colored alcohol leaked from the side seal portion is indicated by ×.

Although preferred embodiments of the present invention have been described above in detail with reference to the accompanying drawings, the present invention is not limited to these examples. It is clear that those skilled in the art to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims, and these also include: It is understood that it naturally falls within the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1, 2, 3, 4...Bag with zipper tape, 10...Film, 11A...First surface, 11B...Second surface, 12...Bottom seal part, 13...Side seal part, 14...Opening part, 20, 40 , 60, 70... Zipper tape, 20A, 40A, 60A, 70A... First member, 20B, 40B, 60B, 70B... Second member, 21A, 21B, 41A, 41B, 61A, 61B, 71A, 71B... Polyolefin part , 211A, 211B, 411A, 411B, 611A, 611B...Base strip, 212A, 212B, 712A, 712B...Engaging portion, 22A, 22B, 42A, 42B, 62A, 62B...Adhesive resin layer, 23A, 23B, 43A , 43B, 63A, 63B... polyester portion, 231A, 231B... joint surface.

Claims (9)

A bag with zipper tape,
The zipper tape is
A first resin formed of a resin composition containing polyolefin as a main polymer, and including a pair of base strips and engaging portions that respectively protrude from opposing surfaces of the pair of base strips and are capable of engaging with each other. part and
a second resin portion formed of a resin composition containing polyester as a main polymer and covering at least a surface of the pair of base strips opposite to the engaging portion;
The bag has a polyester film having heat-sealing properties as a sealant film,
The polyester film contains 100 parts by weight of polyethylene terephthalate resin, 0.1 to 3 parts by weight of styrene-methyl(meth)acrylate-glycidyl methacrylate copolymer, 3 to 20 parts by weight of a softening agent, and a molding aid. Consisting of 0.05 to 1.5 parts by weight of a polyethylene terephthalate resin composition,
The bag with a zipper tape , wherein the softening material includes a polyester resin used for the second resin portion . The bag with a zipper tape according to claim 1, wherein the softening material is an ethylene-(meth)acrylic acid ester copolymer or a copolymer polyester. The bag with a zipper tape according to claim 1 or 2, further comprising an adhesive resin layer located between the first resin part and the second resin part. The bag with a zipper tape according to any one of claims 1 to 3, wherein the second resin portion further at least partially covers an end surface of the base strip in the width direction of the zipper tape. . The zipper according to claim 4, wherein the second resin portion further partially covers a surface of the base strip on the engaging portion side that follows an end surface of the base strip in the width direction of the zipper tape. Bag with tape. According to any one of claims 1 to 5, the second resin portion forms a slab-like portion that extends outward in the width direction from an end surface of the base strip in the width direction of the zipper tape. Bag body with zipper tape as described. The first resin portion includes a plurality of resin portions arranged in parallel in the width direction of the zipper tape,
The bag with zipper tape according to any one of claims 1 to 6, wherein the second resin portion forms a slab-like portion between the plurality of resin portions. The bag with a zipper tape according to any one of claims 1 to 7, wherein the engaging part includes a sealed engaging part in which the male member and the female member are in surface contact with each other. A method for manufacturing a bag with zipper tape according to any one of claims 1 to 7, comprising:
The zipper tape and the polyester film as a sealant film are sandwiched in an overlapping state between the circumferential surface of a rotatable drum and a seal bar having a sealing surface opposing the circumferential surface of the drum. A method for manufacturing a bag with a zipper tape, characterized by including a welding step of thermally welding the bag.

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