JPH0597163A - Packaging bag - Google Patents

Abstract

PURPOSE:To provide a packaging bag which absorbs the oxygen present in food or drink and prevents oxidization of the food or drink leading to loss of its flavor or the degradation by sealing the packaging bag filled with the food or drink. CONSTITUTION:A packaging bag 1 comprises partly or wholly an oxygen absorbing material 3 wherein the polyolefin having tertiary hydrogen is mixed with a transition metal compound in such an amount that 0.001-20wt.% of the transition metal is contained based on the weight of the polymer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an oxygen-absorbing packaging bag. More specifically, the present invention relates to a packaging bag in which an oxygen absorbent obtained by adding a transition metal compound to a polyolefin having tertiary hydrogen constitutes the whole or a part of the structure.

[0002]

2. Description of the Related Art Conventionally, foods, beverages, etc. are heat-sealed in a four-sided sealed bag, a stand pouch, a pillow pouch, a gusset pouch, etc., which are hermetically sealed and oxidized by oxygen permeating from the outside to the inside. It was known to change. In order to prevent the oxidative deterioration of foods and beverages, a method of using a high barrier material that is difficult for oxygen to permeate in the packaging bag is widely used, but a high barrier plastic packaging bag must completely prevent the permeation of oxygen. It is not possible, and the foods and beverages with the contents are gradually oxidized and transformed. Also, from the beginning, the oxygen contained in food and beverages and the oxygen contained in the headspace of the packaging bag will
Since the oxidative deterioration of beverages occurs, the oxidative deterioration of foods and beverages actually occurs even in a completely barrier packaging bag laminated with aluminum foil.

[0003]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above-mentioned conventional problems, and an object thereof is to put an enzyme-sensitive substance such as food or beverage in an oxygen-absorbing bag, By sealing, the packaging bag absorbs the oxygen present in the food and beverage with contents, prevents the oxidative deterioration of the food and beverage, and can maintain the quality of the contents such as food and beverage for a long time. Is to provide.

[0004]

That is, according to the present invention, a transition metal compound is blended with a polyolefin or a copolymer thereof having a tertiary hydrogen in the molecule in an amount of 0.001 to 20% by weight as a transition metal with respect to the polymer. The oxygen absorbing material is an oxygen-absorbing packaging bag that constitutes the whole or a part of the structure of the packaging bag, and the packaging bag contains foods, beverages, pharmaceuticals, precision electronic parts, etc. It is characterized in that the quality of the contents is maintained by making the oxygen concentration of the substance substantially zero.

In the present invention, the polyolefin having a tertiary hydrogen in the molecule or a copolymer thereof is atactic polypropylene, isotactic polypropylene, syndiotactic polypropylene, ethylene propylene copolymer, propylene butene copolymer, propylene. Styrene copolymer, polyisobutene, ethylene isobutene copolymer, poly-4-methylpentene-1, methylpentene ethylene copolymer, propylene methylpentene copolymer, low density polyethylene, polystyrene and the like,
Blends of these tertiary hydrogen-containing polyolefins, these tertiary hydrogen-containing polyolefins and other polymers, that is, tertiary hydrogen-free polyolefins, polyesters, polyamides, polyvinyl chloride, polyvinylidene chloride, chloride Blends with vinylidene-ethyl acrylate copolymer, ethylene vinyl alcohol copolymer, polyacrylonitrile, bisphenol A-based polycarbonate, polysiloxane, cellulose derivative, ionomer, polyurethane and the like are also included.

Here, the polyester means a polycondensate of dicarboxylic acid and glycol, and may be a homopolyester or a copolyester. Examples of polyamides include nylon 6, nylon 66, nylon 6,1
2, metaxylylenediamine / adipic acid type polyamide (MXD-6) and the like.

Preferred metals of the transition metal compound used in the present invention are transition metals having atomic numbers 23 to 29 and rhodium, and at least one kind of compounds of these metals. Examples of these transition metal compounds include organic acid salts of these transition metal ions, acetylacetonate complexes, phthalocyanine complexes, monoalkyl phosphate ester salts, dialkyl phosphate ester salts, aryl phosphate ester salts, and the like. As the compound, those having good compatibility with the above-mentioned oxidizable polymer are particularly desirable. Specifically, in the case of polypropylene, salts of organic acids having a long-chain alkyl group such as stearic acid, palmitic acid, lauric acid, decanoic acid, and octanoic acid, acetylacetonate complex, dihexadecylphosphoric acid. Ester salt, didecyl phosphate ester salt, dibutyl phosphate ester salt, monododecyl phosphate ester acid, 1
-Naphthyl phosphate ester salts and the like. Of course,
The compounds of the transition metals having atomic numbers 23 to 29 and rhodium used in the present invention are not limited to those described above. These transition metal compounds are added to the oxidizable polymer alone or as a mixture, and the addition amount thereof is 0.001 to 20% by weight based on the oxidizable polymer as a metal, It is preferably 0.005% by weight to 10% by weight. If the amount added is less than this, effective oxygen absorption performance cannot be obtained,
If it exceeds this range, improvement of oxygen absorption performance cannot be obtained, and a problem in molding occurs.

Inorganic additives such as activated carbon, titanium oxide, pigments, calcium carbonate and silicon oxide can be blended in the oxygen absorbent of the present invention. It is particularly effective to add a deodorizing agent such as activated carbon or zeolite.

In the present invention, the packaging bag in which the oxygen absorbing material constitutes the entire structure means a polyolefin or a copolymer thereof having a tertiary hydrogen in the molecule, among transition metals having atomic numbers 23 to 29 and rhodium. It refers to a packaging bag consisting only of an oxygen absorbing material to which at least one transition metal compound is added, or a blend of the oxygen absorbing material and another polymer of the oxygen absorbing material.

The packaging bag in which the oxygen absorbing material of the present invention constitutes a part of the structure is the oxygen absorbing material of the present invention or a blend of the oxygen absorbing material and another polymer of the oxygen absorbing material. It refers to the case where it forms part of a bag.

For example, (a) the double-sided sealant is the oxygen absorbent of the present invention (FIG. 1), (b) the one-sided sealant is the oxygen absorbent of the present invention (FIG. 2), and (c) the oxygen absorbent of the present invention. (FIG. 3), the bottom sealant of the stand pouch is the oxygen absorbent of the present invention (FIG. 4),
(E) The case where the intermediate layer is the oxygen absorbent of the present invention (FIG. 5), and (f) one surface of the intermediate layer is the oxygen absorbent of the present invention (FIG. 6), and the like.

The oxygen-absorbing polypropylene film, which is the oxygen-absorbing material of the present invention, does not change its oxygen-absorbing ability even in the unstretched, uniaxially stretched, or biaxially stretched state. It can be used as an ingredient.

[0013]

EXAMPLES The present invention will now be described with reference to examples. Example 1 Melt index 2.5 g / 10 min (230 ° C.)
Cobalt stearate in 100 parts of polypropylene 5.
3 parts (5,000 ppm as cobalt) were mixed and extruded into a film having a thickness of 60 μm. By heat-sealing this film using a 200 ° C. hot plate, 1
In the bag manufactured to have a size of 00 mm × 200 mm, the oxygen concentration in the bag immediately after bag making was 21%, but it decreased to 0.5% after standing at 20 ° C. for 6 days. The oxygen concentration inside the sealed bag formed from the polypropylene film having a thickness of 60 μm, which is a comparative product, was 21% even after 6 days.

Example 2 The oxygen-absorbing polypropylene film having a thickness of 60 μm of Example 1 was laminated with an aluminum foil having a thickness of 7 μm using an ester urethane yarn adhesive and heat-sealed using a hot plate at 200 ° C. , 100 mm x 200 mm
The size of the bag was molded. The oxygen concentration in the bag immediately after bag making was 21%, but it decreased to 0.2% when left at 20 ° C. for 6 days. The oxygen concentration in the bag formed from a film obtained by laminating a general polypropylene film having a thickness of 60 μm as a comparative product with an aluminum foil having a thickness of 7 μm was 21% even after standing for 6 days.

Example 3 An ester urethane adhesive was used on the oxygen-absorbing polypropylene film of Example 1 having a thickness of 60 μm, and the outer surface was covered with 7
A 30 μm thick copolyester (Vylon by Toyobo) film was laminated on the inner surface of an aluminum foil having a thickness of 30 μm. This laminated film is heated by a hot plate at 200 ° C.
It was molded into a bag having a size of 100 mm × 200 mm. The oxygen concentration in the bag immediately after bag making was 21%, but it decreased to 0.2% when left at 20 ° C. for 6 days. Instead of the oxygen-absorbing polypropylene film of the comparative product, the oxygen concentration in the bag using a general polypropylene film of 60 μm was 21% even after being left for 60 days.

Example 4 Copper stearate 4.9 was added to 100 parts of the above polypropylene.
A mixture of parts (5,000 ppm as copper) was extruded into a strand shape by an extruder, cut and formed into a pellet shape. 30 parts of this was blended with 70 parts of an ethylene vinyl alcohol copolymer (ethylene content 32 mol%) and extruded into a sheet to form an oxygen absorbing film having a thickness of 40 μm. Using an ester urethane adhesive, a 12 μm PET (biaxially-stretched polyethylene terephthalate) film is formed on the outer surface of this oxygen-absorbing film, and 70 on the inner surface.
μm CPP (unstretched polypropylene film) was laminated. By heat-sealing this laminated film with a hot plate at 220 ° C., 100 mm × 20
The bag was molded into a bag of 0 mm in size, filled with pure water, and the opening was further heat-sealed for sealing. Then 120 ° C
The retort sterilization was performed for 20 minutes depending on the temperature. After sterilization 2
The container was left at 0 ° C. and the oxygen concentration inside the container was measured. For comparison, a bag in which the ethylene vinyl alcohol copolymer was not blended with the oxygen absorbing polymer in the same constitution was filled with water and subjected to the same treatment, and the oxygen concentration in the bag was measured. The results are shown in Table 1.

[0017]

[Table 1]

[0018]

Industrial Applicability The packaging bag in which the oxygen absorbing material obtained by blending a transition metal with a polyolefin having tertiary hydrogen such as polypropylene of the present invention is used for all or a part of the structure of the packaging bag is the oxygen present in the food. Can be absorbed to prevent oxidative deterioration of foods and beverages.

[Brief description of drawings]

FIG. 1 is a schematic view showing a cross section of a packaging bag of the present invention in which an oxygen absorbent is laminated as a sealant on both inner surfaces of the packaging bag.

FIG. 2 is a schematic view showing a cross section of a packaging bag of the present invention in which an oxygen absorbent is laminated as a sealant on one surface of the inner surface of the packaging bag.

FIG. 3 is a schematic view showing a cross section of a packaging bag of the present invention in which an oxygen absorbing material is laminated on a part of the inner surface of the packaging bag.

FIG. 4 is a schematic view showing a cross section of a stand pouch of the present invention in which an oxygen absorbent is laminated as a sealant on the bottom of the stand pouch.

FIG. 5 is a schematic view showing a cross section of a packaging bag of the present invention in which an oxygen absorbent is laminated as a sealant on the intermediate layers on both sides of the packaging bag.

FIG. 6 is a schematic view showing a cross section of a packaging bag of the present invention in which an oxygen absorbent is laminated as a sealant on an intermediate layer on one surface of the packaging bag.

[Explanation of symbols]

 1 Packaging bag 2 Base material 3 Oxygen absorber

Claims (1)

[Claims] 1. An oxygen absorber containing 0.001 to 20% by weight of a transition metal compound as a transition metal in a polyolefin or a copolymer thereof having a tertiary hydrogen in the molecule as a transition metal has the whole structure of a packaging bag. Or an oxygen-absorbing packaging bag that forms a part.