JPH06100044A - Oxygen absorbing laminate film - Google Patents

Abstract

PURPOSE:To prevent the oxidation of a content from happening and prevent the alteration of the quality from happening by laminating a porous film with a specified maximum hole diameter on an oxygen absorbing film of which the trigger is moisture, for the title film for packaging for beverage such as beer, etc. CONSTITUTION:An oxygen absorbing laminate film is formed by laminating a porous film of which the maximum hole diameter is 1.0mum or lower on an oxygen absorbing film of which the trigger is moisture. As the base resin for the oxygen absorbing film, polyolefine which can be formed into a film up to approx. 170 deg.C, e.g. low density polyethylene, etc., is used. To the base resin, an oxygen absorbing agent such as porphyrin, etc., is blended by approx. 0.01-20 pts.wt. to 100 pts.wt of the base polymer. Also, for the porous film, a polyethylene film is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxygen absorbing laminated film, and more particularly to a laminated film suitable as a packaging material for filling and sealing. More specifically, the present invention relates to an oxygen-absorbing laminated film used as a packaging material for filling and sealing products such as fruit juice drinks that are easily oxidized.

[0002]

2. Description of the Related Art In beverages such as juice and beer, or products such as seasonings and pharmaceuticals, the active ingredient is denatured due to the presence of oxygen, and the quality such as flavor and color tone is changed to lower the commercial value. Conventionally, such products that are easily oxidized are filled in oxygen barrier containers such as bottles and cans, and in order to prevent residual oxygen in the containers, vacuum packaging or free space gas replacement is performed and airtight packaging is performed. ing.

However, such a sealing method requires a high-pressure inert gas supply device and has a low production efficiency. Moreover, the oxygen concentration in the packaging container can only be reduced to about 1 to 2%, and in addition, aroma and volatile components of foods are often lost when oxygen is removed. Further, there is also a method of using a chemical antioxidant as another antioxidant method. In such a method, for example, butylhydroxytoluene, butylhydroxyanisole, ascorbic acid, etc. are added to a food, and oxygen is reacted with an antioxidant before the oxygen reacts with the food to prevent oxidation of the food. However, when such an antioxidant is added to beer or wine, it often gives off-flavor (smell, odor). Also, these antioxidants must be listed on the label as food additives,
In recent years, general consumers who are targeting additive-free foods have a tendency not to be liked. There is also a method of enclosing the oxygen absorbent package, but it is not suitable for liquid products because the components are eluted.

[0004]

[Problems to be Solved by the Invention] International Publication WO91 / 1
Japanese Patent No. 7044 describes that ascorbic acid or a salt thereof is used as an oxygen absorbent to recover oxygen from water. However, there is no description here of using such an oxygen absorbent in a food packaging material to prevent the oxidation of the contents.

It is also known that a plastic containing a compound having a hemoglobin-like structure is used as a liner for a crown of beer or the like and used as an oxygen absorber for the contents. All of these oxygen-absorbing substances are easily decomposed by heat, and when used in a packaging material such as food, a low melting point resin such as polyethylene, EVA, or polyvinyl chloride is used as the packaging material.

However, when an oxygen absorbing film in which an oxygen absorbing substance is fixed to such a resin is immersed in water for a long time, the oxygen absorbing substance is eluted into the contents. For this reason, in the conventional packaging material, oxygen is absorbed in the headspace by being used in the upper part of the container so as not to directly contact the contents. Therefore, it is difficult to absorb the dissolved oxygen in the liquid.

The object of the present invention is to eliminate the invasion of oxygen into the package and effectively reduce not only the oxygen in the free space inside the packaging container but also the dissolved oxygen concentration in the product,
It is intended to provide a packaging material capable of preventing the oxidation of products such as food and drink and maintaining the quality. Another object of the present invention is to provide a film for packaging in which the oxygen-absorbing substance does not elute into the contents even when it is in contact with the contents for a long period of time.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted various studies to solve the above problems, and as a result, by combining an oxygen absorbing film with a film having a specific pore size, the desired effects can be obtained. The present invention has been completed based on the knowledge that a packaging material having the same can be obtained.

The present invention provides an oxygen-absorbing laminated film obtained by laminating a porous film having a maximum pore diameter of 1.0 μm or less on an oxygen-absorbing film whose moisture is a trigger. In the film of the present invention, an oxygen absorbing film and a porous film are laminated.

As the base resin of the oxygen absorbing film, low density polyethylene capable of forming a film at a temperature of up to about 170 ° C.,
Polyolefin such as polypropylene, polyester, polyvinyl chloride and the like are preferable.

Examples of the oxygen absorber include ascorbic acid, ascorbate, porphyrin complexes, macrocyclic polyamine complexes and the like. Examples of the ascorbate include sodium salt, potassium salt, calcium salt and the like. Further, as the porphyrins, metal chelate compounds of porphyrins such as protoporphyrin and tetraphenylporphyrin having Fe, Mg, Zn, Co, Ni, Cu etc. as a central metal, their alkyl esters, or imidazole coordination thereof. Compounds.

Further, examples of the macrocyclic polyamine complex include cyclam complexes such as Fe, Mg, Zn, Co, Ni and Cu as central metals.

The amount of these oxygen absorbents to be mixed with the base resin varies depending on the deoxidizing ability of the oxygen absorbent and its type, but generally 0.01 to 20 parts by weight is added to 100 parts by weight of the base polymer. preferable. If the blending amount is less than 0.01 parts by weight, the oxygen absorbing effect is not sufficient, and even if it exceeds 20 parts by weight, the effect does not change and the film strength decreases, which is not preferable.

By thus blending the oxygen absorbent with the above-mentioned base film, a moisture-triggered oxygen absorbent film can be obtained.

As the porous film laminated on the oxygen absorbing film, a film having a maximum pore size of 1.0 μm or less is used. When the maximum pore size exceeds 1.0 μm, the oxygen absorbing substance is eluted in the product. As such a porous film, Porum (Tokuyama Soda Co., Ltd.)
Manufactured polyethylene film) and Espoir (polyethylene film manufactured by Mitsui Toatsu Chemicals, Inc.).

In order to laminate such a porous film on the oxygen absorbing film, a conventionally known laminating method such as heat lamination may be used.

The oxygen-absorbing laminated film of the present invention is used for fruit juices, carbonated drinks, coffee, teas, alcoholic beverages, seasonings, other foods, pharmaceuticals, and various liquids and viscous substances that are easily oxidized. It is particularly suitable as a packaging material. The film of the present invention starts the reaction with water contained in the content as a trigger to absorb oxygen.

[0018]

The porous film layer of the oxygen-absorbing laminated film of the present invention allows water vapor and oxygen to pass through but does not allow oxygen-absorbing substances to pass through. Therefore, even if it comes into contact with water in the content that triggers oxygen absorption, oxygen will be present in the product. Absorbing substance does not elute. Therefore, it can be used as a packaging material not only in the head space of the container but also in a portion that comes into direct contact with the product.

[0019]

EXAMPLES Next, the present invention will be described in more detail based on examples.

[Example 1] Base resin: low-density polyethylene (melting point: 109 ° C, M
I 2 g / 10 minutes; 190 ° C .; 2.16 kg load) Oxygen absorber: As an oxygen absorber, a porphyrin complex, a macrocyclic polyamine complex, ascorbic acid and Co, F
e, Cu, Zn coordinated or bonded mixture (molar ratio
1: 1: 2) was used. The oxygen absorbent was mixed in an amount of 0.3 part by weight with respect to 100 parts by weight of low density polyethylene.

Porous film: Each film shown in Table 1 was used. Both have a thickness of 30 μm,
Water vapor permeability is 5,000 g / m ² · 24 hours or more. 0.3% of the above oxygen absorber was dry blended with the base resin and extruded at 150 ° C. This film was heat laminated to each of the three types of porous films at 150 ° C.

(Elution Amount of Oxygen Absorbing Substance) The three kinds of oxygen absorbing films (100 μm simple substance + 30 μm porous film) obtained (Test Examples 1 to 3) and oxygen absorbing film simple substance (1
00 μm) (comparative test example), the elution amount of the oxygen absorbing substance into water was measured. For the measurement, the amount of the oxygen absorbing substance eluted in the ion-exchanged water of the sample film was determined by single-sided extraction. For measurement, 1 g of film is 100 m
L ion-exchanged water, static extraction at 40 ℃ 72 hours,
Then, the amount of oxygen absorbing substance eluted in water was measured by atomic absorption. The results are shown in Table 1 below.

Table 1 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Pore diameter (μm) Co Cu Cu Zn Fe Average Maximum (ppm) (ppm) (ppm) (ppm) ───────────────────────────────────── Test Example 1 1 2 1.26 1.04 0.98 0.17 〃 2 0.5 1.5 0.95 0.87 0.65 0.14 〃 3 0.5 1.0 0.82 0.41 0.33 0 ────────────────────────── ─────────── Comparative test example Without lamination 5.31 3.54 3.10 0.12 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ━━━━━━ As in Test Example 3, the oxygen absorbing film had a maximum pore size of 1.0μ.
By thermally laminating the porous film of m, the elution of the oxygen absorbing substance is almost suppressed.

(Measurement of Oxygen Absorption Capability) Next, the laminated films of Test Examples 1 to 3 and the non-laminated film of Comparative Test Example were tested at 60 ° C. and 100%.
The oxygen absorption capacity in RH was evaluated. The results are shown in Table 2 below. The measurement results are shown by the oxygen absorption amount (cc / g) per 1 g of the resin absorbed during that time.

Table 2 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 3 days 7 days 14 days 21 days ─ ─────────────────────────────────── Test Example 1 29.0 31.4 32.5 33.9 〃 2 28.5 31.0 32.6 33.8 〃 3 26.2 28.2 31.9 33.5 ──────────────────────────────────── Comparative test example 29.4 32.9 34.1 34.7 ━━━ ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ A film laminated with a porous film has a slightly lower oxygen absorption rate. However, 30cc / g in 2 weeks
It has the above-mentioned oxygen absorption capacity and has no practical problem. In particular, as shown in Table 1, the laminated film of Test Example 3 completely suppressed the elution of oxygen absorbing substances.

Regarding these laminated films, the consumption amount of potassium permanganate (60 ° C., 3
0 minutes) was measured. The results are shown below.

━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Test example KMnO ₄ consumption (ppm) ─────────── ───────────────── 1 21 2 15 3 8 ━━━━━━━━━━━━━━━━━━━━━━━━━━━ To clear the standard value of 10 ppm or less under the Food Sanitation Law,
It was only Test Example 3.

[0028]

INDUSTRIAL APPLICABILITY The oxygen-absorbing laminate film of the present invention does not leach oxygen-absorbing substances into the product even when it is used as a packaging material in a portion which comes into direct contact with the product. When the laminated film of the present invention is used, the oxygen concentration in the packaged product is lowered, the quality of the packaged article is prevented from changing and deterioration over a long period of time, the flavor and color tone of the food and drink are maintained, and the alteration of the active ingredient is prevented. prevent. The conventional oxygen-absorbing film has been used only as a liner of a cap so as not to come into direct contact with a liquid, but the laminated film of the present invention can also be used at a portion of a liquid container that comes into direct contact with a product such as a flash. You can

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] September 2, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[請 Motomeko 3 oxygen absorbing film porphyrins, macrocyclic polyamine, oxygen-absorbing laminate film of claim 1 further comprising at least one oxygen-absorbing material selected from ascorbic acid and ascorbate.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

Porous film: Each film shown in Table 1 was used. Both have a thickness of 30 μm and a water vapor permeability of 5,
000 g / m ² · 24 hours or more. Dry blend 0.3% of the above oxygen absorber with the base resin to give 150
Extruded at ° C. This film was heat laminated to each of the three types of porous films at 150 ° C.

Claims (3)

[Claims] 1. An oxygen-absorbing laminated film obtained by laminating a porous film having a maximum pore size of 1.0 μm or less on an oxygen-absorbing film whose moisture is a trigger. 2. The oxygen-absorbing laminate film according to claim 1, wherein the oxygen-absorbing film is a polyolefin, polyester or polyvinyl chloride film. 3. The oxygen-absorbing laminate film according to claim 1, wherein the oxygen-absorbing film contains at least one oxygen-absorbing substance selected from porphyrins, macrocyclic polyamines, ascorbic acid and ascorbic acid salts.