JPH0937816A - Engaging element and packaging bag with engaging element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide engaging elements which are well fusible to polyester sealant layers of a bag body and have an excellent reopening and crnshing properties and a packaging bag with these engaging elements. SOLUTION: The engaging elements 11 consist of a fusing part to the bag body 14 and parts exclusive of this part. The fusing part consists of a copolymer of ethylene with an acrylate or a copolymer of ethylene with a methacrylate. The content of the acrylate or the methacrylate in the copolymer is 5 to 40%. The parts exclusive of the fusing part consist of a low-density polyethylene having the modulus of elasticity in bending of 50 to 500MPa. A first layer 22 is formed of the copolymer described above if the engaging elements have band-shaped base parts 15, 18 of two-layered structures consisting of the first layer 22 formed as the fusing part to the bag body 14 and a second layer 23 laminated on this first layer 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engaging device and a packaging bag with an engaging device, which is used for packaging foods and medical products.

[0002]

BACKGROUND ART [PROBLEMS TO BE SOLVED BY THE INVENTION] A band-shaped engaging device (fitting device) including a male member and a female member at an opening portion of a bag.
A zipper bag that can be opened and closed by installing
Is used in many fields such as food, pharmaceuticals and sundries. Then, various methods have been proposed as a method of manufacturing the bag with an engaging device.

For example, a method of integrally extruding and molding a tubular film having a male member and a female member of an articulation tool using an extrusion die, a tape with the articulation tool is manufactured in advance, and this tape is used as a bag. There is a method of heat fusion bonding to a base material film forming a main body. The former method has the drawbacks that if it is made as an integral body from the beginning, it will take up space due to the shape of the articulation tool, which makes it inconvenient to store and handle, and has restrictions on the structure of the base film. So, in recent years,
The latter method, which does not have these drawbacks, is becoming common.

Low density polyethylene (LDPE) and polypropylene (PP) are generally used as the material of the engaging device, and the sealant layer, which is a film layer to which the engaging device of the bag body is fused, is of the same type as the engaging device. It is said to be a resin. For example, when the sealant layer of the base film is made of LDPE, the same LDPE is used as the material of the engaging device. As described above, in the case of the conventional articulator, if the sealant layer is made of the same kind of resin as the articulator, the articulator can be fused to the sealant layer without any trouble.

On the other hand, polyester resins are preferably used as a sealant layer of the bag body because they are excellent in heat resistance, aroma retaining property and gas barrier property. However, when the sealant layer is made of polyester resin, which is a material different from that of the clasp, it is difficult to fuse the clasp to the bag body, and it is difficult to use the polyester resin as the sealant layer. It was

In order to solve such a problem, conventionally,
When the sealant layer of the bag body is made of a polyester resin, an articulation tool containing polybutylene terephthalate (PBT) as a main component has been proposed (Japanese Patent Laid-Open No. 6-91540). However, although the articulation tool having PBT as a main component can be well fused to the polyester sealant layer of the bag body, it has high rigidity and is difficult to be repeatedly opened and resealed.

[0007] Therefore, an object of the present invention is to provide an occluding tool and a packaging bag with an occluding tool which can be well fused to the polyester-based sealant layer of the bag body and have excellent resealability.

[0008]

In the articulation tool according to the first aspect of the present invention, the male member and the female member to be occluded each have a fusion-bonded portion to the bag body and a portion other than this fusion-bonded portion. The fusion-bonded portion is made of a copolymer of ethylene and acrylic acid ester or a copolymer of ethylene and methacrylic acid ester. The copolymer of ethylene and acrylic acid ester and the copolymer of ethylene and methacrylic acid ester are one type of polyester elastomer.

[0012] According to a second aspect of the present invention, an engaging device according to the first aspect is characterized in that the content of acrylic acid ester or methacrylic acid ester in the copolymer is 5 to 40%. The content of acrylic acid ester or methacrylic acid ester in the copolymer is the adhesive strength between the fused portion and the portion other than the fused portion (or the adhesive strength with the bag body).
There is no practical problem as long as the adhesive strength between the fused portion and the portion other than the fused portion is higher than the occlusal strength between the male member and the female member.

From this point of view, the content of acrylic acid ester or methacrylic acid ester in the copolymer is preferably 5.0 to 40.0 wt%, and more preferably 15.0 to 2 wt%.
5.0 wt%. If it is less than 5.0 wt%, there is a risk that peeling may occur at the interface between the fusion-bonded portion and the portion other than the fusion-bonded portion when the bite is opened and closed again. On the other hand, when the content is higher than 40.0 wt%, the fusion strength with the film on the bag body side becomes larger, but the compatibility with the portion other than the fusion bonded portion becomes low.

A third aspect of the present invention is an engaging device according to the first or second aspect, which is characterized in that the portion other than the fusion-bonding portion is made of low density polyethylene having a bending elastic modulus of 50 to 500 MPa. When the bending elastic modulus of the portion other than the fusion-bonded portion is less than the above range, the occlusal strength is weakened, and feeding out during bag making becomes difficult. On the other hand, if it exceeds the above range, the strength after repeated opening and resealing may be reduced, or the occlusion device may be damaged.

Among the above low density polyethylene, it is particularly preferable to use linear low density polyethylene (L-LDPE).
The MI of the low-density polyethylene is 1 to 15 g /
10 min is preferred, more preferably 2-8 g / 10 min
belongs to. If MI is less than 1 g / 10 min, melt fracture tends to occur, and if it is more than 15 g / 10 min, moldability (mold holding property) deteriorates. Note that parts other than LDPE, such as PP, EVA, and EMAA, can be used for parts other than the fusion-bonded part, but LDPE is generally used as the material of the articulating device. It is preferable to provide an adhesive resin layer between the fusion-bonded portion to the bag body and the portion other than the fusion-bonded portion in order to increase the adhesive strength between the two.

An articulating tool according to a fourth aspect of the present invention is the first to the first aspect.
In any one of the third aspect of the present invention, the belt-shaped base has a two-layer structure including a first layer that is the fusion-bonded portion to the bag body, and a second layer that is laminated on the first layer, Is a copolymer of ethylene and acrylic acid ester or a copolymer of ethylene and methacrylic acid ester. The belt-shaped base may be one layer and all the layers may be fusion-bonded parts. However, in order to prevent fusion of the male-member-side belt-shaped base and the female-member-side belt-shaped base during bag-making, such a 2 A layered structure is desirable.

An articulating tool according to a fifth aspect of the present invention is the first to the first aspect.
In any one of the fourth invention, the copolymer of ethylene and acrylic acid ester is ethylene-methyl acrylate random copolymer (EMA) or ethylene-ethyl acrylate random copolymer (EEA), The copolymer of ethylene and methacrylic acid ester is characterized in that it is an ethylene-methyl methacrylate random copolymer (EMMA). All of these have good adhesiveness to a polyester resin, for example, a PBT resin, but from the viewpoint of odor, EMA and EMMA are preferable, and EMMA is more preferable.

The packaging bag with an engaging device according to a sixth aspect of the present invention is that the engaging device according to any one of the first to fifth aspects is fused to the bag body via the fusion-bonding portion. Characterize.

A packaging bag with an engaging device according to a seventh aspect of the present invention is characterized in that, in the sixth aspect, the film layer fused with the fusion portion of the engaging device of the bag body is made of polyester resin. And The polyester resin includes polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyester elastomer, polycarbonate and the like. Also, a blend of a polyester resin and a polyolefin resin may be used.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIGS. 1 and 2, an articulation tool 11 according to the present embodiment comprises a belt-shaped male member 12 on one side and a female member 12 on the one side.
It has 12 and the other female member 13 which occludes. The male member 12 is a strip-shaped base 1 that is fused to the bag body 14.
5. A head 16 having a heart-shaped cross section and a connecting portion 17 having a rod-shaped cross section for connecting the both 15 and 16. The female member 13 has a strip-shaped base portion 18 fused to the bag body 14, a circular arc-shaped first hook portion 19 formed on the base portion 18, and the strip-shaped base portion 18 so as to face the first hook portion 19. The second hook portion 21 is formed in a circular arc shape.

Band-shaped bases 15 and 18 of the male member 12 and the female member 13
Is a first layer 22 which is a fusion-bonded portion to the bag body 14, and the first layer 22.
It has a two-layer structure with a second layer 23 laminated on 22. Male member
In 12, the second layer 23, the connecting portion 17 and the head 16
Is an integral body made of the same material. Further, in the female member 13, the second layer 23 and the first and second hook portions 19 and 21 are integrated.

The first layer 22 is made of ethylene-methyl acrylate random copolymer (EMA), ethylene-
Ethyl acrylate random copolymer (EEA) or ethylene-methyl methacrylate random copolymer (EMM
It consists of A). The content of methyl acrylate (MA) or methyl methacrylate (MMA) in these copolymers is 5 to 40%. On the other hand, in the male member 12 and the female member 13, the second layer 23 which is a portion other than the first layer 22 and the connecting portion 1
7, head 16, hooks 19, 21 are made of low density polyethylene (LD
PE). This LDPE has a flexural modulus of 50-500 MPa,
MI: 1 to 15 g / 10 min.

The male member 12 can be manufactured by fusion-bonding the first layer 22 and the other portions 23, 17, 16 by coextrusion. Similarly, the female member 13 also has the first layer 22.
And other portions 23, 19, and 21 can be manufactured by fusing by coextrusion. In the bag 24 with the engaging device 11, the first device 22 of the belt-shaped bases 15 and 18 of the members 12 and 13 is fused and attached to the film 25 constituting the bag body 14 of the engaging device 11. The film 25 is made of polyester.

[0021]

EXAMPLES Example 1 In the above embodiment, the first layer 22 of the strip-shaped base portions 15 and 18 is formed of an ethylene-methyl acrylate random copolymer (EMA) having a methyl acrylate (MA) content of 7 wt%.
And In addition, the first layer 22 in the male member 12 and the female member 13
The second layer 23, the connecting portion 17, the head portion 16, and the hook portions 19 and 21, which are other portions, were made of low density polyethylene (LDPE) having a bending elastic modulus of 150 MPa and MI of 6 g / 10 min. In addition, the film 25 forming the bag body 14 is a stretched polyethylene terephthalate (P
ET) layer / polybutylene terephthalate (PBT) and polyether copolymer layer having a two-layer structure,
The copolymer layer of BT and polyether was used as a sealant.

[Examples 2 to 9] In Example 1, the acrylic acid in the copolymer of ethylene and acrylic acid ester (or methacrylic acid ester), which is the material of the first layer 22 of the strip-shaped base portions 15 and 18, is used. The type of ester (or methacrylic acid ester) and the content thereof were changed to obtain the occlusion tool of each example.

That is, in Example 2, EMA having a methyl acrylate (MA) content of 18 wt% was used. In Example 3, EMA having a MA content of 27 wt% was used. In Example 4, an ethylene-methyl methacrylate random copolymer (EMM) having a methyl methacrylate (MMA) content of 7 wt% was used.
A) was used. LDPE of the male member 12 and the female member 13 other than the first layer 22 used in this embodiment has a bending elastic modulus of 200 MPa, M
I: 6g / 10min.

In Example 5, EM having an MMA content of 18 wt%
MA was used. In Example 6, E with an MMA content of 38 wt% was used.
MMA was used. In Example 7, ethyl acrylate (E
A) An ethylene-ethyl acrylate random copolymer (EEA) having a content of 9 wt% was used. Used in this example
LDPE has a bending elastic modulus of 250 MPa and MI of 6 g / 10 min. In Example 8, EEA having an EA content of 19 wt% was used. In Example 9, EEA having an EA content of 35 wt% was used.

[Comparative Examples 1 to 6] In Example 1, the acrylic ester in the copolymer of ethylene and acrylic ester (methacrylic ester), which is the material of the first layer 22 of the strip bases 15 and 18 The type and content of (methacrylic acid ester) were changed to obtain the occlusion tool of each comparative example.

That is, in Comparative Example 1, EMA having a MA content of 3 wt% was used. In Comparative Example 2, E with an MA content of 45 wt% was used.
MA was used. In Comparative Example 3, E with an MMA content of 3 wt%
MMA was used. In Comparative Example 4, EMMA having an MMA content of 45 wt% was used. In Comparative Example 5, EMA having an EA content of 3 wt% was used. In Comparative Example 6, E with an EA content of 45 wt%
MA was used.

Next, various characteristics of the bite tool 11 of Examples 1 to 9 and Comparative Examples 1 to 6 were evaluated. That is, the evaluated characteristics are the rigidity of the occlusion device, the repeatability of opening and closing, the odor of the occlusion device, the adhesive strength (second layer) between the fusion part (first layer) and the part other than the fusion part (second layer) to the bag body ( In the table, abbreviated as base adhesive strength), heat sealability of the articulation device to the bag body, and crushability of the articulation device at the end of the bag. The evaluation results are shown in Tables 1 to 3.
Shown in

The evaluation method and evaluation criteria for the above characteristics are as follows. The rigidity of the bite was evaluated by bending the bite by hand and feeling it. ◯: It has an appropriate rigidity.
X: Quite soft or fairly hard. The repetitive opening and closing property was evaluated by measuring the decrease in strength after repeatedly opening and closing the occlusion device 10 times. ○: Strength reduction is less than 0.2 kg / 50 mm. B: Strength reduction is 0.2 to less than 0.5 kg / 50 mm. X: Strength reduction is 0.5 kg / 50 mm or more.

The odor of the occlusion device was judged by a plurality of panelists. ◯: Almost odorless. Δ: Some apple odor. The adhesive strength (base adhesive strength) between the fusion-bonded portion and the portion other than the fusion-bonded portion to the bag body was evaluated by examining whether or not the adhesive strength was greater than the occlusal strength between the male member and the female member. . ◯: Has sufficient adhesive strength. X: The adhesive strength is weak.

The heat sealability of the bite to the bag body was measured by measuring the relationship between the seal strength and the seal temperature of the bite to the bag body composed of the stretched PET layer / PBT and the copolymer layer of polyether. evaluated. ○: Seal temperature is 150
A seal strength of 1 kg / 15 mm or more can be obtained even at temperatures below ℃. Δ: Seal strength of 1 kg / 15 mm or more is obtained at a seal temperature of 150 to 200 ° C. X: Seal strength is 1 kg even if the seal temperature is 200 ° C or higher
Less than / 15mm. The crushability of the bite at the end of the bag was determined by visually observing the collapsed state of the bite. ○: The crushed state is good. X: The crushed state is poor.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

[Table 3]

From Tables 1 and 2, the occlusion tool according to Examples 1 to 9
According to 11, the strip-shaped bases 15 and 18 of the male member 12 and the female member 13 are
It has a two-layer structure of a first layer 22 which is a fusion-bonded portion to the bag body 14 and a second layer 23 which is laminated on the first layer 22.
Is a copolymer of ethylene and acrylic acid ester or a copolymer of ethylene and methacrylic acid ester, and the content of acrylic acid ester or methacrylic acid ester in the copolymer is 5 to 40%. , Articulator 11
Odor, adhesive strength between the first layer 22 and the second layer 23, and the clasp 11
It can be seen that all the properties of the heat sealability of the bag body 14 to the polyester-based sealant layer are excellent.

Further, in this embodiment, the bending elastic modulus of the portion other than the first layer 22 is low density polyethylene having a bending elastic modulus of 50 to 500 MPa, whereby the rigidity of the articulation device 11 itself and the repetitive opening / closing property are increased, and the bag is further formed. The crushing property of the articulation tool 11 at the end of the is improved.

On the other hand, from Table 3, according to Comparative Examples 1 to 6,
The structure and material of the articulation tool 11 are the same as those in the embodiment, but the first layer
Since the content of acrylic acid ester or methacrylic acid ester in the copolymer constituting 22 is out of the range of 5 to 40%, the odor of the bite tool 11 and the adhesion between the first layer 22 and the second layer 23 It can be seen that there is a problem in at least one of the strength and the heat sealability of the engaging device 11 to the bag body 14.

[0037]

EFFECTS OF THE INVENTION According to the clasp and the packaging bag with the clasp according to the present invention, it can be well fused to the polyester-based sealant layer of the bag body and is also excellent in resealability.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an engaging device and a packaging bag with an engaging device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of an occlusion device and a packaging bag with an occlusion device according to the same embodiment.

[Explanation of symbols]

 11 Coupling tool 12 Male member 13 Female member 14 Bag body 15,18 Band base 19 First hook portion 21 Second hook portion 22 First layer 23 Second layer 24 Packaging bag 25 Film constituting the bag body

Claims (7)

[Claims] 1. An occluding male member and a female member each have a fusion-bonded portion to a bag body and a portion other than this fusion-bonded portion, and the fusion-bonded portion is a mixture of ethylene and an acrylic ester. An occlusion tool comprising a polymer or a copolymer of ethylene and a methacrylic acid ester. 2. The occlusion device according to claim 1, wherein the content of acrylic acid ester or methacrylic acid ester in the copolymer is 5 to 40%. 3. The occlusion device according to claim 1, wherein the portion other than the fusion-bonded portion is made of low density polyethylene having a bending elastic modulus of 50 to 500 MPa. 4. A first layer serving as the fusion-bonded portion to the bag body,
It has a strip-shaped base portion having a two-layer structure with the second layer laminated on the first layer, and the first layer is made of a copolymer of ethylene and an acrylate ester or a copolymer of ethylene and a methacrylic acid ester. The occlusion tool according to any one of claims 1 to 3, wherein 5. The copolymer of ethylene and acrylic acid ester is ethylene-methyl acrylate random copolymer (EMA) or ethylene-ethyl acrylate random copolymer (EEA), wherein the ethylene and methacrylic acid copolymer are ethylene-methacrylic acid random copolymer (EMA). The occlusion device according to any one of claims 1 to 4, wherein the copolymer with the acid ester is an ethylene-methyl methacrylate random copolymer (EMMA). 6. A packaging bag with an engaging device, wherein the engaging device according to any one of claims 1 to 5 is fused to the bag main body via the fusion bonding part. 7. The packaging bag with an engaging device according to claim 6, wherein the film layer fused with the fusion bonding portion of the engaging device of the bag body is made of polyester resin.