JP2003231533A - Plastic zipper tape having excellent adhesiveness to polyacrylonitrile resin film and packaging bag using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plastic zipper tape having a fusing layer which can have an excellent adhesiveness to the plastic zipper and a packaging bag with a zipper using it, when the inmost layer of a bag itself in the packaging bag with a zipper is a polyacrylonitrile resin layer (sealant layer). <P>SOLUTION: The plastic zipper tape has the fusing layer, which is formed of a resin composition composed of (1) 20 to 70 wt.% of an ethylene- ethylacrylate copolymer, (2) 20 to 70 wt.% of an ethylene-vinylacetate copolymer and (3) 10 to 20 wt.% of at least one of resin selected from a group consisting of petroleum resin, turpentine resin and a rosin-type resin, on the bonding surface to the innermost layer of the bag itself. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic zipper tape used as a zipper packaging bag having a polyacrylonitrile (hereinafter sometimes abbreviated as PAN) resin film as an innermost layer, and a zipper packaging bag using the same. Regarding

[0002]

2. Description of the Related Art A plastic bag which is provided with a plastic zipper (zipper) at the opening of the bag and can be resealed once opened is widely used in daily life for the purpose of storing foods.

The PAN resin film is particularly excellent in gas barrier properties against oxygen and carbon dioxide gas, has resistance to alcohols, esters, halogenated hydrocarbons, etc., and has a small amount of adsorbed aromatic components such as menthol and camphor. Since it has the characteristics of (1), it is particularly useful as a sealant (sealing material for preventing invasion of liquid or gas) used as a plastic bag body for packaging foods, chemicals, electronic parts and the like.

Since the PAN resin exhibits a heat-sealing property with a strength of about 2 to 3 kgf / 15 mm between the PAN resin films, both the innermost layer (sealant layer) of the bag body and the plastic zipper can be made of the PAN resin. For example, a plastic bag having good adhesiveness between the two can be formed. However, although it is technically possible to manufacture a plastic zipper from PAN resin, since PAN resin is sensitive to shear heat, an extruder with a low shear rate is used when molding, and the resin molding temperature is It is necessary to keep the width of the mold narrow and to reduce the retention area in the mold flow path. Further, due to the above properties of the PAN resin, the moldability of the claw portion of the zipper is poor and the manufacturing cost is increased. Therefore, it is not realistic to manufacture a plastic zipper from PAN resin.

The material for the plastic zipper is usually linear low density polyethylene (L-LDP).
E), low-density polyethylene (LDPE), ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer or a resin obtained by adding an elastomer or the like to these resins is used. The adhesiveness between the plastic zipper made of other materials and the PAN resin film is low, and a means for improving the adhesiveness is required.

As a means for improving the adhesiveness between the innermost layer of the bag body (the layer which is directly adhered to the plastic zipper) and the plastic zipper made of a material different from the resin forming the innermost layer, the adhesive surface is It is known to provide a fusing layer.

For example, in Japanese Unexamined Patent Publication No. 1-279062, an occlusal device (zipper) is composed of two layers, a fusion layer to the bag body and other parts (claw part and flange part) including occlusal concrete, An occluding tool having a structure in which the innermost layer of the bag main body and the occlusal concrete are adhered by the fusion-bonding layer is shown, and the fusion-bonding layer is formed of at least an ionomer resin. With such a configuration, the object is to cope with various combinations of the material of the articulation tool and the material of the base film (innermost layer). By configuring the articulating device in two layers as described above, the occlusal strength, the unsealing property and the like of the articulating device can be appropriately adjusted. The invention described in this publication is mainly effective when the innermost layer of the bag body is made of the same ionomer resin system as that used to form the fusion bonding layer.

Further, Japanese Patent Laid-Open No. 2-258562 has the same constitution and purpose, and that the fusion layer to the bag body is formed of at least ethylene and an acrylic acid-based random copolymer resin. It has a feature. In the invention described in this publication, like the invention of the above publication, the innermost layer of the bag body is
It is mainly effective when the fusion layer is made of the same type of ethylene and acrylic acid type random copolymer resin.

[0009]

However, none of the above publications describes any material that forms an effective fusion bonding layer when the innermost layer of the bag body is a PAN resin film. Therefore, in the present invention, when the innermost layer of the bag body is a PAN resin film (sealant layer),
An object of the present invention is to provide a plastic zipper tape having a fusing layer capable of obtaining good adhesiveness with a plastic zipper. A further object of the present invention is to provide a zipper-equipped packaging bag in which the innermost layer of the bag body made of a PAN resin film and a plastic zipper are adhered by the fusion layer.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to achieve the above object, and have made (1) an ethylene-ethyl acrylate copolymer (hereinafter referred to as EEA), (2) an ethylene-vinyl acetate copolymer. A resin composition containing a polymer (hereinafter, EVA) and (3) at least one resin selected from the group consisting of petroleum resin, turpentine resin and rosin resin exhibits good adhesion to a PAN resin film. Heading The invention has been reached.

That is, according to the present invention, (1) ethylene-ethyl acrylate copolymer (EEA) 20 to 70% by weight, and (2) ethylene-vinyl acetate copolymer ( EVA) 20 to 70% by weight and (3) 10 to 20% by weight of at least one resin selected from the group consisting of petroleum resin, turpentine resin and rosin resin, and a fusion layer formed of the resin composition. A plastic zipper tape having good adhesion to a polyacrylonitrile resin film, which is characterized by the above. Furthermore, the present invention is directed to polyacrylonitrile (PA
N) To provide a packaging bag with a zipper, in which the plastic zipper tape is adhered to a bag body having a resin film as the innermost layer.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
The plastic zipper tape of the present invention has (1) an ethylene-ethyl acrylate copolymer (EEA) and (2) an ethylene-vinyl acetate copolymer (E) on the adhesive surface to the bag body.
VA) and (3) a fusion layer formed of a resin composition containing at least one resin selected from the group consisting of petroleum resin, turpentine resin and rosin resin. (Hereinafter, the resin composition forming the fusion layer may be referred to as a fusion resin)

(1) The ethylene-ethyl acrylate copolymer (hereinafter sometimes abbreviated as EEA) has a content of 20 to 20.
It is mixed in a ratio of 70% by weight. The content ratio of EEA is 2
If it is less than 0% by weight, the adhesive strength to the PAN resin film will be reduced, and if it exceeds 70% by weight, it may adhere to metal parts such as molds and cooling rolls during molding, which is not preferable. In EEA, the proportion of ethyl acrylate copolymerized with ethylene is preferably 8 to 18% by weight, and particularly preferably 8% by weight from the viewpoint of heat sealing temperature and compatibility as a food packaging material.

(2) The ethylene-vinyl acetate copolymer (hereinafter sometimes abbreviated as EVA) is blended in a proportion of 20 to 70% by weight. 20% by weight of EVA content
If it is less than 70% by weight, the stability of the resin is lowered and the physical properties are likely to change due to temperature. In EVA, the proportion of vinyl acetate copolymerized with ethylene is preferably 8 to 10% by weight because an appropriate heat sealing temperature can be obtained. Since EVA is excellent in low-temperature sealing property and foreign substance sealing property, and also has good compatibility with EEA, it is preferable to adjust the final composition balance with EVA.

(3) At least one resin selected from the group consisting of petroleum resin, turpentine resin and rosin resin is blended in a proportion of 10 to 20% by weight. These resins impart tackiness to the fusion-bonding resin for maintaining a temporary adhesion state until the fusion-bonding resin of the present invention is cooled and fixed during heat sealing. The mixing ratio of these resins can be appropriately increased / decreased by the cooling time in the bag-making machine and the force applied from the outside, but in the case of a general bag-making machine, it is not necessary to mix the resin in excess of 20% by weight. .
If it is less than 10% by weight, the necessary temporary adhesion state is not sufficiently retained, which is not preferable. Here, the petroleum resin is a resin obtained by directly using a petroleum-based unsaturated hydrocarbon, and specific examples thereof include an alkylstyrene indene resin and the like. The turpentine resin and the rosin-based resin are extracts of pine and are used in various industrial applications.

The fusion resin used in the present invention can be compounded according to a method usually used in the art. In addition, commercially available product Hirodine 758 corresponding to the fusion resin
9 (manufactured by Hirodyne Industry Co., Ltd.) and the like can also be used.

The melting point of the fusion-bonding resin used in the present invention is the melting point of the crystalline resin when it is a crystalline resin, and is the DSC method [JIS K7122] when it is an amorphous resin.
The melting point measured according to the above, or if the melting point is unclear by the DSC method, the lowest temperature at which the resins can be fused is defined as the melting point. The melting point of the fusion-bonding resin of the present invention is usually about 90 to 100 ° C.

The melting point of the fusion-bonding resin used in the present invention needs to be lower than the melting point of the resin forming the zipper portion, and is preferably 10 ° C. or more lower than the melting point of the resin forming the zipper portion. If the melting point of the fusion-bonding resin is higher than the melting point of the resin forming the zipper part, when the zipper and the PAN resin film are melt-bonded, the flange part and the claw part of the zipper are likely to be deformed, resulting in a decrease in productivity. .

Adhesive strength (JIS Z) between the fusion resin and the PAN resin film used in the present invention by heat sealing.
(According to 0238) is 0.40 to 0.50 kgf / 15
It is about mm.

Next, the structure of the plastic zipper tape of the present invention will be described. The plastic zipper tape of the present invention comprises a zipper portion and a fusion layer made of the fusion resin.

As shown in FIG. 3, the zipper parts are a pair of a male claw part A and a female claw part B which constitute a zipper.
And these flange portions C. As shown in FIG. 2, a fusing layer D made of the above fusing resin is formed on the surface of the flange portion C on the side opposite to the claw portion (the surface that is bonded to the innermost layer of the bag body).
Are formed into the plastic zipper tape of the present invention. The zipper part is usually linear low density polyethylene (L-LDPE), low density polyethylene (LDPE),
Ethylene-vinyl acetate copolymer (EVA), ethylene-
It is formed of an acrylic acid-based copolymer or a resin obtained by adding an elastomer or the like to these resins. The resin forming these zipper portions is a resin of the same type as the fusion-bonding resin, so that the resin has a good affinity and the adhesiveness between them is good.

The thickness of the fusion layer is usually about 10 to 40 μm. The plastic zipper tape of the present invention is produced as described above, and is used by being bonded (fused) to the inside of the bag body having the PAN resin film as the innermost layer.

Next, the packaging bag with a zipper of the present invention in which the above plastic zipper tape is adhered to the bag body having the PAN resin film as the innermost layer will be described. The bag body of the packaging bag of the present invention has the PAN resin film as the innermost layer. That is, the innermost layer of the packaging bag of the present invention, that is, the surface of the plastic zipper tape that is bonded to the fusion layer D is a PAN resin film. The bag body is P
It may be composed of a single layer of AN resin film, or PA
It may be composed of a plurality of layers in which a film made of another resin is laminated on the outside of the N resin film.
Examples of the film to be laminated when it is made of a plurality of layers include a resin film and a metal foil film. Examples of the material of the resin film include thermoplastic resins such as polyethylene, polypropylene, polyethylene terephthalate and polyamide. Examples of the material of the metal foil film include aluminum foil and aluminum vapor deposition film.

When a metal foil such as an aluminum foil is laminated on the outside of the PAN resin film, the melting point of the resin forming the zipper portion needs to be lower than the melting point of the PAN resin, which is lower than 10 ° C. Is desirable. When the melting point of the resin forming the zipper portion is higher than the melting point of the PAN resin, the metal foil is likely to be cracked when the nail portion is crushed at the end portion of the zipper in the process of manufacturing the packaging bag. Therefore, in order to satisfactorily manufacture the packaging bag of the present invention, it is preferable that the melting point of the resin forming each part is lowered in the following order: PAN
Resin-> resin that forms the zipper portion-> fusion resin that forms the fusion layer D. Here, the melting point of the PAN resin is usually 130 to 1
40 ° C.

The packaging bag of the present invention can be manufactured using a bag-making machine usually used in the art. As shown in FIG. 1, the fusion layer D of the plastic zipper tape in which the claws are occluded and the PAN resin film which is the innermost layer of the bag body are heated by a heat seal bar to bond them. The temperature of the heat seal bar is usually 150-180 ° C.
Is.

[0026]

EXAMPLES The present invention will be described more specifically by showing Examples and Comparative Examples. Example 1 Two PAN resin films each having a total thickness of 65 μm obtained by laminating a polyethylene terephthalate (PET) resin film having a thickness of 25 μm, an aluminum foil having a thickness of 7 μm and a PAN resin (melting point 130 ° C.) film having a thickness of 25 μm were used. Layered face up.

Linear low density polyethylene (melting point 120
C.), the claw portions A and B of the zipper have a width of 1.8 mm, a height of 1.8 mm, the width of the tape including the flange portion C is 12 mm, and the thickness of the flange portion C is 180 μm. And, on the surface of the flange portion on the side opposite to the zipper claw portion, Hirodyne 7589 (made by Hirodyne Industry Co., Ltd., a resin composition comprising EEA, EVA and petroleum resin;
A melting layer D having a melting point of 96 ° C. and a thickness of 30 μm was formed to obtain a plastic zipper tape of the present invention.

Next, as shown in FIG. 1, the occluded plastic zipper tape obtained above was sandwiched between the above two films, and a bag making machine was used to measure a height of 170 mm and a width of 170 mm. 210 mm flat bag 60 shown in FIG.
0 sheets were manufactured. The temperature of the heat seal bar for bonding the zipper tape and the PAN resin film was 170 ° C.

From the flat bag thus obtained, 30 pieces were randomly sampled and the zipper part and the innermost layer of the bag body, PA.
The adhesive strength with the N resin film was measured by the method of JIS Z0238, and the average value was 0.47 kgf / 15 m.
m, and the standard deviation was 0.025 kgf / 15 mm. Further, in any of the samples, no crack was observed in the aluminum foil at the zipper crushed portion at the end of the zipper.

From the above results, the fusion bonding resin used in the present invention comprises a plastic zipper and a PAN resin film.
It has been revealed that the bonding can be performed with a strength that can be put to practical use. Therefore, the packaging bag of the present invention has a sufficient strength for opening and closing the zipper as a bag body with a zipper having the PAN resin film as an adhesive surface to the zipper portion, and when a metal foil is laminated on the bag body. It became clear that cracks did not occur.

Comparative Example 1 A laminated film similar to that of Example 1 and a plastic zipper tape having the same size and the same material as Example 1 except that the fusion layer D was not provided were used. Similarly, at the temperature of the heat seal bar of 170 ℃, the flat bag 600
Sheets were manufactured. 3 randomly from the obtained 600 flat bags
When 0 sheets were taken out as a sample and the adhesive strength between the zipper part and the innermost PAN resin film of the bag body was measured in the same manner as in Example 1, the average value was 0 kgf / 15 m.
m and the standard deviation was 0 kgf / 15 mm. Therefore, it was clear that the packaging bag manufactured in Comparative Example 1 was not practical.

[0032]

EFFECTS OF THE INVENTION According to the present invention, despite being a sealant material having excellent properties such as gas barrier properties, it is not possible to obtain sufficient adhesiveness with the zipper portion, so that a bag with a zipper can be obtained. P that was difficult to apply
A plastic zipper tape having a fusing layer made of a fusing resin capable of adhering an AN resin film and a plastic zipper with sufficient strength is provided.

Further, according to the present invention, there is provided a packaging bag with a zipper, which is obtained by adhering the above-mentioned plastic zipper tape to a PAN resin film which is the innermost layer of the bag body.

[Brief description of drawings]

FIG. 1 is a sectional view of a zipper-bonded portion of a packaging bag of the present invention.

FIG. 2 is a cross-sectional view of the plastic zipper tape of the present invention.

FIG. 3 is a cross-sectional view showing a structure of a zipper portion of a plastic zipper tape.

FIG. 4 is a sectional view showing an overall image of the packaging bag with a zipper of the present invention.

[Explanation of symbols]

A: Zipper male nail B: Female claw of zipper C: Flange part of zipper D: fusion layer E: PAN resin film layer

   ─────────────────────────────────────────────────── ─── Continued front page    (71) Applicant 500139383             Tomen Plastic Sales Co., Ltd.             2-14-27 Akasaka, Minato-ku, Tokyo (72) Inventor Toshikazu Kasai             3-19-4-207 Noge, Setagaya-ku, Tokyo (72) Inventor Yukihiko Shibata             1-7-23 Kinjo, Kita-ku, Nagoya-shi, Aichi Yamato             Gravia Co., Ltd. F-term (reference) 3E064 BA17 BA26 BA30 BA36 BA55                       BA60 BB03 BC08 BC18 EA01                       EA30 HN13 HN18

Claims (3)

[Claims] 1. The adhesive surface of the bag body with the innermost layer is (1) 20 to 70% by weight of ethylene-ethyl acrylate copolymer, (2) 20 to 70% by weight of ethylene-vinyl acetate copolymer and (3) ) At least one resin selected from the group consisting of petroleum resin, turpentine resin and rosin resin 10
A plastic zipper tape having good adhesiveness to a polyacrylonitrile resin film, which has a fusion layer formed of a resin composition of 20 wt%. 2. The melting point of the resin composition forming the fusion layer is
The plastic zipper tape according to claim 1, which is lower than both the melting point of the resin forming the zipper portion and the melting point of the polyacrylonitrile resin. 3. A packaging bag with a zipper, characterized in that the plastic zipper tape according to claim 1 is adhered to a bag body having a polyacrylonitrile resin film as an innermost layer.