JPH01206036A - Packaging material for package containing oxygen scavenger - Google Patents

Abstract

PURPOSE:To enable the cost to be reduced by providing the transparent thin film layer of silicon oxide having a ratio 1:0.3-1.8 of silicon atom. to oxygen atom. on the one side surface of a plastic basement, and making the material thin in obtaining an sufficient barrier ability. CONSTITUTION:The transparent thin film layer of silicon oxide is provided on base film. The ratio of the silicon atom. to oxygen atom. of the silicon oxide in the transparent thin film layer is made to be 1:0.3-1.8 and the thickness of the transparent thin film layer is made to be 400-3,000(Angstrom ). And a heat sealing layer or protecting layer or the like is provided according to the use. A vacuum deposition method or chemical deposition method or the like is employed for forming the transparent thin film layer of the silicon oxide, the mixture of SiO or Si and SiO2 is used as a evaporating material. The packaging material may be transparent as well as having a high barrier ability and the oxygen permeability is below 2.0cc/m<2>.24hrs, furthermore, moisture permeability is at most 3.0g/m<2>.24hrs. Consequently, the packed foods may be preserved in long term.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a packaging material containing an oxygen absorber for packaging. More specifically, the present invention relates to a transparent packaging material that is used to encapsulate and package foods together with an oxygen absorber, and which has excellent barrier properties against oxygen and the like.

[Conventional technology]

In the preservation of foods, prevention of mold growth, oxidation, corrosion, discoloration, flavor preservation, etc. are extremely important. Moreover, it is preferable that these conditions are maintained for a long period of time, thereby making it possible to store foods for a long period of time without deterioration of quality. For this purpose, the packaging material must have excellent barrier properties against oxygen, water vapor, and the like. For example, the growth of mold depends on conditions such as the water activity of the food itself, pH, and the presence or absence of bacterial growth, but in cases where mold grows due to residual oxygen in the packaging container, oxygen absorbers are conventionally included. Methods such as Packaging containing oxygen absorbers is also used to prevent oxidation, prevent discoloration, and preserve flavor. As such packaging materials, biaxially oriented polypropylene film or nylon film coated with polyvinylidene chloride resin, or aluminum foil are used.

[Problem to be solved by the invention]

The one coated with the polyvinylidene chloride resin has a high oxygen permeability of 3 to 20cc4・24hrs,
The oxygen concentration inside the package cannot be reduced unless the oxygen scavenger's oxygen scavenging ability is fully taken into account when packaging. In addition, polyvinylidene chloride resin does not have sufficient barrier properties, and to improve this, it is usually necessary to increase the film thickness by 80 to 120 mm, which may increase the film cost or reduce the cost. There are problems such as loss of flexibility. Although packaging materials using aluminum foil have excellent barrier properties, they are not transparent and the contents cannot be seen at all, making it difficult for consumers to make product selections at stores.

In view of the above points, an object of the present invention is to provide a transparent packaging material for packaging containing an oxygen absorber that has excellent barrier properties against oxygen and is suitable for packaging using an oxygen absorber.

[Means to solve the problem]

The packaging material containing an oxygen absorber of the present invention includes a plastic base material and a transparent silicon oxide material having a ratio of silicon atoms to oxygen atoms of l20.3 to 2, which is provided on one side of the plastic base material. It is characterized by consisting of a thin film layer.

[For production]

In the packaging material of the present invention, a transparent thin film layer of silicon oxide is provided on a base film, and this material has excellent barrier properties against oxygen, water vapor, and the like. For this reason, when food is packaged with an oxygen absorber, oxygen gas does not enter the package, so the oxygen concentration inside the package can be lowered, food quality deterioration can be suppressed, long-term storage can be achieved, and the use of oxygen absorbers can be reduced. . Furthermore, since it has sufficient barrier properties, the packaging material can be made thinner, making it possible to reduce costs.

〔Example〕

The transparent plastic substrate used in the present invention is not particularly limited, and for example, films or sheets of nylon, polyester, ethylene-vinyl alcohol copolymer, polycarbonate, polyacrylonitrile, polypropylene, etc. can be used. Polyester, which has low water vapor and gas permeability, strength, and workability,
Nylon and polypropylene are preferred.

The thickness varies depending on the intended use of the packaging material, and is appropriately selected from a wide range of 8 to 30 mm, with 12 to 20 mm being particularly preferred.

The silicon oxide in the transparent thin film layer has a ratio of silicon atoms to oxygen atoms of 1:0.3 to 2, more preferably 1:0.3 to 2.
1.8, Nakanzu<t:0. It is preferable that y~1.3. If the proportion of oxygen atoms is greater than the above range, the barrier properties will be lowered, and especially if it is greater than 1:2, the desired barrier properties cannot be obtained.

On the other hand, if the proportion of oxygen atoms is less than the above range, the barrier properties will be good but the transparency will be poor. Particularly preferred is one in which the ratio of silicon atoms to oxygen atoms is about 1=1.

The thickness of the transparent thin film layer is preferably in the range of 400 to 3000. If the thickness is less than 400, sufficient barrier properties cannot be obtained, and if it exceeds 3,000, the cost will increase. In addition, cracks are likely to occur, and the degree of discoloration increases as the thickness increases.

For forming such a transparent thin film layer of silicon oxide, a physical vapor deposition (PVD) method such as a vacuum evaporation method, a sputtering method, an ion blating method, or a chemical vapor deposition (CVD) method is appropriately used. In the vacuum evaporation method, SiO or a mixture of St and 8102 is used as the evaporation source material. To arbitrarily change the ratio of silicon atoms to oxygen atoms in the transparent thin film layer within the above range, use S as an evaporation source material.
This can be carried out by a method of binary vapor deposition using 1 and 5i02 and changing their ratios.

The packaging material of the present invention may be used as it is depending on the intended use, or may be further provided with a heat-sealing layer, a protective layer, or the like.

There are no particular limitations on the heat seal layer, and examples include unstretched polypropylene, polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-vinyl acetate copolymer, and ethylene-acrylic acid copolymer. Examples include ethylene ionomers such as copolymers. The heat seal layer is usually provided by dry lamination or extrusion.

The thickness may range from 20 to 100 ρ, preferably from 40 to 80 ρ.

The protective layer is provided by laminating films of polyester, nylon, ethylene-vinyl alcohol copolymer, etc., or by coating with epoxy resin, melamine resin, urethane resin, polyester resin, etc.

The packaging material of the present invention is transparent and has high barrier properties. That is, the oxygen permeability is 2.0cc/rf・
Less than 24hrs and moisture permeability of 3.0g/d
・Less than 24 hours. Therefore, food products packaged with oxygen absorbers encapsulated in the packaging material of the present invention can be stored for a long period of time.

The packaging material of the present invention can be used for packaging Japanese and Western confectionery, seafood paste products, dried foods, rice cakes, tsukudani, and the like. Examples of packaging forms used include bags, lids, cups, tubes, standing bags, and trays. A heat-sealing layer is necessary for applications such as bags, tubes, and standing bags, but not necessarily for applications such as cups, lids, and trays.

Furthermore, it may be printed for decoration or to explain the contents, or it may be bonded to a reinforcing material such as a decorative printing film or a nylon film to form a composite.

Example 1 An 810 layer with a thickness of 600 layers was formed on one side of a polyester film with a thickness of 12 mm using 810 as an evaporation source, and a polyester adhesive was further applied on this vapor deposition surface with a thickness of 3 mm. After coating and drying at 80℃ for 20 seconds, 2k
A bag film was prepared by dry laminating a 40-mu thick unstretched polypropylene film under a pressure of g/aJ at 100° C. for 1 second.

Example 2 In Example 1, a mixture of Sl and 3102 was used as the evaporation source as a transparent thin film layer, and 8101.8101. A bag film was produced in the same manner as in Example 1, except that layer a was formed.

Example 3 A bag film having the same structure as in Example 1 was produced except that the polyester film in Example 1 was replaced with a 12-thick nylon film.

Comparative Example 1 A polyvinylidene chloride resin was coated on a 12-layer nylon film to a thickness of 3 layers, and then a 60-print thick unstretched polypropylene film was laminated thereon in the same manner as in Example 1 to make a bag. A film was produced.

Comparative Example 2 A 15-thick biaxially stretched polypropylene film was coated with polyvinylidene chloride resin on the 3-thickness side, and an 80-thick unstretched polypropylene film was further laminated thereon in the same manner as in Example 1. A film for bags was produced.

The oxygen permeability of the obtained bag film was measured.

In addition, I made a bag with a size of 18c+n x 25cm using each bag film, filled it with 10 cut rice cakes and 10g of a commercially available oxygen absorber (FX type) made by Mitsubishi Gas Chemical, and sealed it.
The oxygen concentration inside the bag was checked over time. those results first
Shown in the table. In addition, oxygen concentration was determined by gas chromatography method,
The oxygen gas permeability was determined as a1 according to the MOCON method.

In Comparative Example 1.2, the oxygen concentration rapidly increased after 30 days, and some mold had grown after 55 days. On the other hand, in Examples 1 to 3, the increase in oxygen concentration was small, the flavor was retained even after 60 days, and no mold was generated.

This shows that the packaging material of the present invention has very good barrier properties against oxygen.

〔Effect of the invention〕

The packaging material of the present invention is transparent and has excellent barrier properties against oxygen and water vapor, so when packaging food with an oxygen absorber, oxygen gas does not enter the packaging, resulting in mold growth and food oxidation. etc., and food can be stored for a long period of time without deterioration of quality. Furthermore, since the packaging material has sufficient barrier properties even when made thin, costs can be reduced.

Patent Applicant: Oike Kogyo Co., Ltd. Procedure Uchiguchi (spontaneous) 1. Indication of the case, 1988 Patent Application No. 31072, 2. Name of the invention, Packaging material for packaging containing an oxygen absorber, 3. Person making the amendment, 5. Subject of the amendment ( 1) "Claims" column of the specification (2J Contents of amendment in "Detailed Description of the Invention" column 6 of the specification (1) "Claims" column (2J) ” shall be corrected as follows.

('2J Specification page 4 lines 4-5 rl: 0.3-2"
is corrected to ``rl:0.3 to 1.8''.

(3) On page 5, lines 11-12, "the ratio is . . . among others" is corrected to "the ratio is 1:0.3 to 1.8, among others."

(4) rl on page 5, lines 14-15: 2J to rl:1
．． Correct it to 8J.

7 List of Attached Documents (1) Amended Claims 1 Amended Claims 1. A plastic base material and a ratio of silicon atoms to oxygen atoms provided on one side of the plastic base material. 1: O
A transparent packaging material containing an oxygen scavenger and having barrier properties comprising a transparent thin film layer of silicon oxide.

2. The packaging material containing an oxygen absorber according to claim 1, further comprising a heat seal layer on the transparent thin film layer. "that's all

Claims (1)

[Claims] 1. A plastic base material and a silicon atom to oxygen atom ratio provided on one side of the plastic base material of 1:0.3 to 1:0.3.
2. A transparent packaging material containing an oxygen scavenger and having barrier properties comprising a transparent thin film layer of silicon oxide. 2. The packaging material containing an oxygen absorber according to claim 1, further comprising a heat seal layer on the transparent thin film layer.