JP2002292812A - Exterior package for oxygen scavenger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exterior package for an oxygen scavenger suitable for preservation and distribution, excellent in oxygen barrier properties, steam barrier properties and pinhole resistance, and also having no anxiety of environmental pollution at the time of incineration disposal. SOLUTION: In the exterior package for the oxygen scavenger comprising an oxygen barrier film housing the oxygen scavenger, the oxygen barrier film comprises a multilayered film consisting of a biaxially stretched polypropylene resin layer (A), a biaxially stretched polyamide resin layer (B) containing crystalline nylon MXD6 and a sealant resin layer (C).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxygen-absorbing agent package containing an oxygen-absorbing agent.

[0002]

2. Description of the Related Art In recent years, a method using an oxygen scavenger has been established as a simple and reliable method for preserving easily oxidizable articles such as foodstuffs, pharmaceuticals, cosmetics, and the like, which are susceptible to microbial contamination and spoilage such as mold. Oxygen absorbers in the form of pouches, sheets, films and the like have been industrially manufactured.
These oxygen absorbers can be obtained by collecting a certain number of pouch-shaped oxygen absorbers, or by cutting a sheet-shaped or film-shaped oxygen absorber into a certain length, or by continuous packaging of a pouch-shaped oxygen absorber. Each bobbin whose body (web) has been wound up by a certain number is packaged with an oxygen barrier film and stored and subjected to a distribution process.

Conventionally, a stretched nylon (KON) / polyethylene (PE) coated with polyvinylidene chloride (hereinafter, for example, laminated in the order of a KON layer and a PE layer) has been used as an oxygen barrier container for storing an oxygen scavenger. Multilayer films are referred to as KON / PE).

However, in recent years, as a large number of packages containing oxygen scavengers have been manufactured and the distribution process of product transportation has become complicated and intense, physical handling of the conventional KON / PE package has been increasing. Insufficient strength may cause pinholes in the multilayer film during the transportation and distribution process, and the oxygen invading the oxygen scavenger may cause a situation. In order to be able to be handled practically, sufficient pinhole resistance is required, and its piercing strength needs to be 12 N or more.

On the other hand, packaging materials having excellent gas barrier properties include saponified ethylene-vinyl acetate copolymer (EV).
OH) A resin layer and a layer composition including a polyamide resin layer made of a blend of crystalline nylon MXD6 and another nylon are disclosed in Japanese Patent Application Laid-Open No. Hei 4-216050, in which a heat seal layer / a biaxially stretched EVOH layer / polypropylene, nylon or The layer configuration of the polyester biaxially stretched film layer is disclosed in
Each is described in JP-A-3-35778. However, the saponified ethylene-vinyl acetate copolymer layer (EVOH), which is the base material of the intermediate layer, has a weak steam barrier property and is insufficient as a container for storing and distributing an oxygen scavenger.

[0006]

In an oxygen barrier film for packaging an oxygen scavenger, the oxygen scavenger sometimes contains water which is a catalyst for developing oxygen absorbing activity. High water vapor barrier properties so that it does not volatilize outside the container.Generally, because it is stored and stored under reduced pressure by degassing operation, it has high strength and pinhole resistance, and can withstand severe handling in the logistics process. Is required to have sufficient strength and pinhole resistance, and to have good operability at the time of sealing or opening.

[0007] Further, as for the chlorine-containing material, there is a concern that a chlorine-containing compound is generated at the time of incineration disposal to cause environmental pollution. Therefore, a chlorine-free material is desired.

An object of the present invention is to solve the above-mentioned problems of the prior art in the preservation and distribution of an oxygen scavenger, to provide a good balance of oxygen barrier properties, water vapor barrier properties and pinhole resistance, and to be functionally satisfactory. An object of the present invention is to provide an oxygen-absorbing agent outer package using a material which does not cause environmental pollution at the time of incineration disposal.

[0009]

As a result of studying a method for solving the above-mentioned problems, the present inventor has found that (A) biaxially oriented polypropylene (OPP), (B) an oriented polyamide resin layer,
(C) A multilayer stretched film including a sealant resin layer, wherein the polyamide resin (B) is a crystalline nylon MXD6
A single film or a mixture of crystalline nylon MXD6 and other nylons, or a composite film of crystalline MXD6 nylon as a base material and another resin film (a film containing crystalline nylon MXD6 in the above sense, In the present invention, it has been found that the object can be easily achieved by using a stretched laminated film composed of a crystalline nylon MXD6 film), and the present invention has been completed.

That is, the present invention relates to an outer package of an oxygen-absorbing agent comprising an oxygen-barrier film containing an oxygen-absorbing agent, wherein the oxygen-barrier film comprises (A) a biaxially stretched polypropylene resin layer. , (B) crystalline nylon MX
A biaxially stretched polyamide resin layer containing D6, and (C)
An oxygen-absorbing exterior package, which is a multilayer film composed of a sealant resin layer. With this configuration, the excellent oxygen barrier property of MXD6 is maintained,
The steam barrier property and pinhole resistance have been improved to practical levels, and there is no concern about environmental pollution during incineration disposal.
There is provided an outer package body that can safely store the oxygen scavenger and provide it to the distribution process.

[0011]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, (A) a biaxially stretched polypropylene resin layer, and (B) a crystalline nylon MXD
A multilayer film comprising a stretched polyamide resin layer containing No. 6 and a sealant resin layer (C) is used.

As the (A) biaxially oriented polypropylene (OPP) resin used in the present invention, a film obtained by biaxially stretching various crystalline propylene polymers can be used.
Examples of the propylene polymer include a propylene homopolymer and a copolymer of propylene with a small amount of another olefin. Auxiliary components such as antioxidants, antiblocking agents, lubricants, antistatic agents, coloring agents, concealing agents, and other additives which can be usually added to the polypropylene polymer may be used.

The stretching ratio of OPP is not particularly limited as long as the stretching effect basically appears, but is usually 1.5 times or more in the warp direction, 2.0 or more in the weft direction, preferably 3.0 in the warp direction. 7.0 to 7.0 times, and the latitude direction is 5.0 to 12.0 times.

(B) Crystalline nylon MX used in the present invention
Biaxially stretched polyamide resin layer containing D6 (OMXD
6) refers to a crystalline nylon MXD6 single layer obtained by polycondensation of meta-xylylenediamine and adipic acid, or a stretched film composed of an MXD6-based polyamide resin layer composed of a mixture of crystalline nylon MXD6 and amorphous nylon It is a layer. A composite nylon film layer composed of crystalline MXD6 nylon and another nylon resin film can also be used. Crystalline nylon MXD6 is
It is produced by condensation polymerization of meta-xylene diamine (MXDA) obtained by ammoxidation and reduction of meta-xylene with adipic acid.

Further, other amorphous nylons mixed with crystalline nylon MXD6 may be prepared by a combination of dicarboxylic acid and diamine as a raw material, or a melt polymerization under pressure, a decarboxylation condensation reaction using lactam, diisocyanate or the like. Can be used. Here, examples of the dicarboxylic acid include adipic acid, suberic acid, azelaic acid, terephthalic acid, and isophthalic acid. As the diamine, for example, hexamethylenediamine, trimethylhexamethylenediamine,
Isophoronediamine, bis-p- (aminocyclohexyl) methane, bis-p- (aminocyclohexyl) ethane and the like are used. As a lactam, for example, ε-
Caprolactam, lauroca prolactam and the like. As the diisocyanate, for example, diphenylmethane diisocyanate, tolylene diisocyanate and the like are used. Further, other nylon to be mixed can be obtained by a polycondensation reaction of ω-aminocarboxylic acid, a polycondensation reaction of dibasic acid and dicarboxylic acid, and the like. Nylon 6, nylon 12, nylon 11, nylon 6 -6, nylon 6-10, nylon 6-12, and copolymers or mixtures thereof.

(B) The weight ratio of the crystalline nylon MXD6 and the amorphous nylon constituting the MXD6-based polyamide resin layer composed of the crystalline nylon MXD6 alone layer or the mixture of the crystalline nylon MXD6 and the amorphous nylon is as follows: ,Ten
0/0 to 20/80. The MXD6-based polyamide resin consisting of crystalline nylon MXD6 alone or a mixture of crystalline nylon MXD6 and amorphous nylon has a stretching temperature of 50 to 1
Stretched at 50 ° C. under the condition of a draw ratio of 2 to 6 times and stretched MX
D6 nylon (OMXD6) is obtained.

(B) The biaxially stretched polyamide resin containing the crystalline nylon MXD6 can be used under stretching conditions at which a stretching effect is exhibited, for example, at a stretching temperature of 50 to 150 ° C. and a stretching ratio of 2 to 6.
A stretched polyamide that has been biaxially stretched under double conditions is preferred.

The sealant resin layer (C) used in the present invention is made of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDP).
E), polyethylene (PE) such as high-density polyethylene (HDPE), olefin resins such as polypropylene (PP), ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMM)
A), ethylene-ethyl acrylate copolymer (EE
A), ethylene-methyl acrylate copolymer (EM
A), ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMMA), ionomer (ION), etc. Ethylene copolymer resin. Among them, LD
Olefin-based resins such as PE and LLDPE are more preferably used.

Each of the layers (A), (B) and (C) can be laminated by an extrusion lamination method in which an adhesive resin (Ad) is used and is extruded and laminated between the layers. The adhesive resin (Ad) used at that time includes low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and medium-density polyethylene (MDP).
E), polyethylene (PE) such as high-density polyethylene (HDPE), olefin-based resins such as polypropylene (PP), ethylene-vinyl acetate copolymer (EVA), ethylene-methyl methacrylate copolymer (EMM)
A), ethylene-ethyl acrylate copolymer (EE
A), ethylene-methyl acrylate copolymer (EM
A), ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA-MAH), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMMA), ionomer (ION), etc. In addition to the ethylene copolymer-based resins, modified polyolefin-based resins, for example, ethylene-vinyl acetate copolymer or ethylene-based elastomer, monobasic unsaturated fatty acid such as acrylic acid or methacrylic acid, or maleic Examples thereof include those in which an anhydride of a dibasic fatty acid such as an acid, fumaric acid or itaconic acid is chemically bound.

The outer package of the present invention is a multilayer film package having a thickness of 250 μm or less containing an oxygen scavenger. (A) The thickness of the biaxially stretched polypropylene resin layer is 10 to
A range of 30 μm is preferred. When the thickness is 10 μm or less, the pinhole resistance decreases, and when the thickness is 30 μm or more, the total thickness of the laminated film increases, and the handleability decreases. (B) The range of 15 to 30 μm of the biaxially stretched polyamide resin layer containing the crystalline nylon MXD6 is preferably functional and cost-effective. (C) The thickness of the sealant is preferably in the range of 20 to 60 μm. If it is 20 μm or less, the sealing strength is reduced, and there is a concern about breakage during use. If the thickness is 60 μm or more, the cost is increased, and the total thickness of the film is increased, so that the handleability is reduced. When an adhesive resin layer (Ad) for bonding these layers is used, its thickness is 10 to 25 μm.
Is preferable in terms of workability, economy and handling.

As a method for producing the outer package of the present invention, for example, in the case of a three-layer five-layer film of (A) / (Ad) / (B) / (Ad) / (C), first, (A) While feeding the OPP film and the (B) OMXD6 film by a roll, the adhesive resin layer (Ad) is melt-extruded and laminated and bonded therebetween, and further, the adhesiveness between the (B) OMXD6 film surface and the (C) sealant layer is further improved. The resin layer (Ad) is extruded, laminated, and adhered to obtain the above-mentioned three-layer, five-layer multilayer package.

Here, a film composed of the number of base film types (n) and the number of adhesive resin layers (m) is referred to as an n-type m-layer film. The adhesive resin layer has a thickness of 5 μm or more and 25
It is a layer of 0 μm or less. It does not include a layer having a thickness of less than 5 μm, such as a dry lamination adhesive or a coating agent. In the present invention, a material containing halogen such as vinylidene chloride is not used.

The multilayer film used in the present invention comprises (A) OPP, (B) OMXD6,
(C) Each layer of the sealant is manufactured by individually manufacturing a film corresponding to each layer, and then attaching the interlayer with an adhesive resin or an adhesive. Examples of the bonding (lamination) method at that time include an extrusion lamination method in which the adhesive resin layer (Ad) is extruded and laminated between the layers, and a dry lamination method in which an adhesive is applied to each layer or a part thereof, pressed, and dried. can give. Specifically, as a lamination method between the A / B layers, the direct adhesion between (A) the biaxially stretched polypropylene (OPP) resin layer and (B) the stretched MXD6-based nylon (ODXD6-based) resin layer is not good. In addition, the extruded lamination method in which an adhesive resin layer (Ad) having a thickness between layers and also serving as a cushion and also improving the adhesiveness is applied to a thinner layer of the adhesive because the layer lacks flexibility. Normal,
(Several μm or less) It is more preferable than the dry lamination method of attaching. In addition, the extrusion lamination method and the dry lamination method can be applied between the B / C layers, but the extrusion lamination method is more preferable because the package needs some flexibility.

The outer package obtained by the present invention has a water vapor permeability of 0.6 to 1.0 g / at 25 ° C. and 0 → 75% RH.
m ² · 24 hr or less, oxygen permeability 25 ° C, 60% RH
20 ml / m ² · 24 hr · atm or less, and the piercing strength is 12 N / pen tip radius 0.5 mm, 50 mm /
min or more. As a result of the study by the present inventors, it has been found that pinhole occurrence accidents are sharply reduced at a puncture strength of 10 N. Therefore, in consideration of the safety factor, if the piercing strength is 12 N or more, it can be determined that the pinhole has practically good pinhole resistance in handling.

The oxygen absorber to be packaged is an oxygen-absorbing substance exemplified by iron and ascorbic acid, which is packaged in a breathable packaging material or blended with a thermoplastic resin. It is an oxygen absorber in any form such as a shape and a film. Specifically, it is an accumulation of a pouch-shaped oxygen absorber, a bobbin wound around a continuous bag (web) of the pouch-shaped oxygen absorber, or a bundle or roll of the oxygen absorber in the form of a sheet or a film. .

The outer package of the present invention is a package used for storing and distributing the produced oxygen absorber, but can be widely used as a package for other food and drink bottles and barrels. The outer package is usually sealed with the sealant layers and sealed by various heat-sealing methods, for example, a method such as a heat bar seal, an impulse seal, and a high-frequency seal, to obtain a bag-shaped container. Then, a certain amount of the produced oxygen scavenger is stored therein, and if necessary, a vacuum operation or a degassing operation is performed, and then the container is sealed and subjected to a storage and distribution process.

[0027]

The present invention will be described below in detail with reference to examples. The physical properties of the multilayer film or the oxygen-absorbing agent exterior package obtained in the examples were measured by the following methods. (1) Water vapor permeability Unit: g / m ² · 24 hr The obtained multilayer film was measured according to JIS-Z-0208. Oxygen permeability Unit: ml / m ² · 24 hr The obtained multilayer film is subjected to an oxygen permeability measurement apparatus (OXY-TRAN, manufactured by Modern Control Co., Ltd.) at 25 ° C. and 60% RH
100 type).

(3) Puncture strength (pinhole resistance)
Unit: N (Newton) / Pin tip radius 0.5 mm, 50
mm / min The obtained multilayer film is 1 mm in diameter and has a radius of curvature of 0.1 mm.
A 5 mm pin was pierced under a speed condition of 50 mm / min, and the load (N) when the hole was opened was measured. (4) Drop test A roll body formed by spirally winding a continuous bag (web) consisting of 3,000 small bag-shaped oxygen absorber packages (manufactured by Mitsubishi Gas Chemical Co., Ltd., trade name: Ageless Z-23PTR) in series on a bobbin Was sealed by a heat sealing method while performing a depressurizing operation using the obtained multilayer film to obtain 10 samples of the oxygen-absorbing exterior package, and these oxygen-absorbing exterior packages were placed on a concrete floor from a height of 2 m. After the natural film was repeatedly dropped 10 times, the multilayer film was observed for damage or pinholes.

Example 1 A biaxially oriented polypropylene (OPP) having a thickness of 20 μm (trade name: U-1 manufactured by Tosello Co., Ltd.) and a film having a thickness of 1 on one side
A 5 μm biaxially stretched crystalline nylon MXD6 (trade name: MX Nylon 6580, manufactured by Mitsubishi Gas Chemical Co., Ltd.) is fed by a hot roll so as to face each other, and a low-density polyethylene-based adhesive resin (Mitsui Chemicals, Inc.) is interposed therebetween. Melolan 11P) manufactured at 300 ° C.
OPP / adhesive resin /
A laminated film of MXD6 = 20/15/15 μm was obtained. Next, the MXD6 side of the obtained film and linear low density polyethylene (LLDPE) as a sealant resin
(Tux-FCD, manufactured by Tocelo Co., Ltd.) While the film is opposed to the film by a hot roll, the low-density polyethylene-based adhesive resin is melt-extruded during this time and bonded by an extrusion lamination method. OPP / adhesive resin / MXD6 / adhesive resin / LLDPE = 20 /
A 15/15/15/30 μm three-layer five-layer film (total thickness 95 μm) was obtained. The obtained multilayer film was measured for water vapor permeability, oxygen permeability, and piercing strength (pinhole resistance) by the above-mentioned methods. The results are shown in Table 1. Each measurement was performed 10 times and the range of the numerical value was shown.

From Table 1, it was found that the pinhole resistance can be greatly improved and improved to 12 N or more, which is a reference value capable of practically handling, while maintaining the steam barrier property and the oxygen barrier property. Next, the obtained three kinds 5
A drop test was performed using the layer film. After the drop test, there was no breakage or pinhole in the oxygen absorber package. Furthermore, the adhesive resin layer (Ad) between the (A) layer and the (B) layer improved the adhesiveness in a cushioning manner, and had high flexibility and handleability (handleability).

[0031]

[Table 1]

Comparative Example 1 In Example 1, instead of OPP / adhesive resin / MXD6, a polyvinylidene chloride-coated 15-μm thick biaxially stretched nylon (KON) (manufactured by Toyobo Co., Ltd., trade name N
-812AE), and a multilayer film was prepared in exactly the same manner except that the film was adhered by an extrusion lamination method, and the water vapor permeability, oxygen permeability, and piercing strength (pinhole resistance) were measured. The results are shown in Table 1. Next, a drop test was performed using the obtained multilayer film. After the drop test, pinholes were observed in the multilayer film of two samples among the ten samples of the oxygen-absorbing agent outer package.

Example 2 In Example 1, a biaxially oriented polypropylene (OPP) having a thickness of 25 μm (trade name: U-1 manufactured by Tosello Co., Ltd.) was used as the (A) layer. (B) MXD
A urethane adhesive (manufactured by Takeda Pharmaceutical Co., Ltd.)
(A315 / A12), and laminated by dry lamination (adhesive thickness: about 3 μm). (C) Linear low-density polyethylene (LLDPE) having a thickness of 40 μm as a sealant resin layer (manufactured by Tocelo Corporation, trade name) TUX-
Using FCD), a three-layer, four-layer film was prepared in exactly the same manner except that the thickness of the PE-based adhesive resin layer (Ad) between the layers (B) and (C) was changed to 20 μm. Oxygen permeability and piercing strength (pinhole resistance) were measured. The results are shown in Table 1.

From the results shown in Table 1, (A) the OPP layer and (B)
It can be seen that the method of dry lamination between the MXD6 layers can also improve and improve practical pinhole resistance while maintaining the water vapor barrier property and the oxygen barrier property. Next, a drop test was performed using the obtained multilayer film. After the drop test, none of the oxygen-absorbing agent exterior packages showed any damage or pinholes.

Example 3 In Example 1, (C) a linear low-density polyethylene (LLDPE) (trade name: TUX-FCD, manufactured by Tocelo Co., Ltd.) having a thickness of 40 μm was used as the sealant resin layer.
Layer 3 and layer 3 (B) and layer (B) and layer (C), except that the respective layers were bonded by dry lamination.
A layer film was prepared, and the water vapor transmission rate, oxygen transmission rate, and piercing strength (pinhole resistance) were measured. The results are shown in Table 1.

From the results in Table 1, it can be seen that OPP / MXD6 / LL
It can be seen that even when the layers of the DPE are bonded by the dry lamination method, the water vapor barrier property and the oxygen barrier property can be maintained, and at the same time, the practical pinhole resistance can be improved and improved. Next, a drop test was performed using the obtained multilayer film. After the drop test, there was no breakage or pinhole in the oxygen absorber package.

[0037]

According to the present invention, the water vapor barrier property and the oxygen barrier property can be maintained, and at the same time, the piercing strength (pinhole resistance) can be improved and improved to a sufficiently practical level. Without the worry of contamination,
It is possible to realize an oxygen-absorbing agent outer package that can safely store the oxygen-absorbing agent and other articles in a storage and distribution process. Further, in the oxygen-absorbing agent outer package of the present invention, since a material containing halogen such as vinylidene chloride is not used, there is no concern about environmental pollution at the time of incineration disposal.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B29L 7:00 B29L 7:00 9:00 9:00 F term (Reference) 3E086 BA04 BA15 BA33 BB02 BB05 CA29 DA08 4F100 AK01C AK03G AK06G AK07A AK46B AK63C BA03 BA07 BA15 CB00 EC03 EH23 GB15 JA20A JA20B JA20C JD03 JD04 JK01 JL11C YY00 YY00A YY00B YY00C 4F210 AA11 AA29 AG01 AG03 QC05 Q

Claims (5)

[Claims] 1. An outer package for an oxygen-absorbing agent comprising an oxygen-barrier film containing an oxygen-absorbing agent, wherein the oxygen-barrier film comprises (A) a biaxially stretched polypropylene resin layer, and (B) An oxygen-absorbing agent outer package, which is a multilayer film comprising a biaxially stretched polyamide resin layer containing crystalline nylon MXD6 and (C) a sealant resin layer. 2. The oxygen barrier film according to claim 1, wherein (A) a resin layer and (B) a resin layer, or (B) a resin layer and (C) a resin layer, laminated by (Ad) an adhesive polyolefin resin layer. The outer package according to claim 1, wherein the outer package is a laminated multilayer film. 3. The oxygen barrier film is a multilayer film in which (A) a resin layer and (B) a resin layer or (B) a resin layer and (C) a resin layer are laminated by a dry lamination method. The outer package according to claim 1. 4. The oxygen barrier film according to claim 1, wherein (A) the resin layer has a thickness of 10 to 30 μm, and (B) the resin layer has a thickness of 1 to 30 μm.
The outer package according to claim 1, wherein the resin package has a thickness of 5 to 30 m and the resin layer has a thickness of 20 to 60 m. 5. The oxygen barrier film having a water vapor permeability of 0.6 to 1.0 g / m ² · 24 hr (25 ° C., 0 ° C.).
→ 75% RH) and the oxygen permeability is 20 ml / m ²
・ 24 hr ・ atm (25 ° C., 60% RH) or less, and the piercing strength is 12 N / ball tip radius 0.5 m
The outer package according to claim 1, wherein m is 50 mm / min or more.