JPH02263645A - Package - Google Patents

Abstract

PURPOSE:To improve gas permeability, in a package entirely or partially composed of a sheet having a multilayer structure, by forming the uppermost layer of the sheet having the multilayer structure from a polymethyl pentene film. CONSTITUTION:In a package entirely or partially composed of a sheet having a multilayer structure, the uppermost layer A of the sheet having the multilayer structure is constituted of a polymethyl pentene film. Next, in a middle layer B, paper having Gurley air permeability of 1000sec/100ml or less, a nonwoven fabric made of plastic or a microporous plastic film is used. As the paper, Japanese paper, machine-made paper, synthetic paper or plastic mixed paper is used and, as the nonwoven fabric, one prepared by bonding plastic fibers composed of polyethylene, polypropylene, polyester or nylon in a sheet shape by heat, pressure or an adhesive is used. By this method, a package having high gas permeability can be obtained without requiring special perforation treatment or micro-perforation treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to packaging. For more details, in recent years, in the field of processed foods and fresh foods, agents to maintain their freshness such as oxygen scavengers, carbon dioxide absorbers, carbon dioxide gas generators, alcohol generators, de-ethylenizers, and deodorizers have been introduced. It is used in a wide variety of ways. As a result, significant progress has been made in the packaging bodies (packaging materials) used for these products.

However, it cannot be said that a fully satisfactory packaging body that is gas permeable, water resistant, and has good productivity has been developed as described below. For example, packaging used for humid foods, fresh foods, etc. must be water and oil resistant (11).

(2) Since reverse printing is often performed, the material used for the outermost layer must be transparent.

(3) The softening point must be sufficiently high to prevent fusion in heat seal packaging.

(4) Sufficient gas permeability.

(5) Requirements such as high-speed filling and sufficient strength are required. In order to meet these requirements, a multilayer package is generally used, and the outermost layer thereof is made of a transparent plastic film or the like that has been subjected to perforation treatment or perforation treatment.

Problems to be Solved by the Invention There is a desire for the development of a packaging body that does not require special processes such as perforation treatment or perforation treatment, has high gas permeability, and is capable of high-speed filling and packaging. Note that it is desirable that the paper has a multilayer structure and that the top layer is transparent so that printing on the back side can be done and the printing can be easily read.

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors conducted extensive research and found that a sheet with a multilayer structure in which a polymethylpentene film is arranged as the top layer has sufficient gas permeability. We have completed the present invention by discovering that the present invention not only exhibits the desired results but also has excellent performance as described above. That is, the present invention provides a package that is made entirely or partially of a sheet having a multilayer structure, the uppermost layer of the sheet having a multilayer structure being
A gas permeable packaging body made of polymethylpentene film is provided.

The present invention will be described in detail.

Although various shapes can be adopted as the shape of the package of the present invention, typical shapes are shown in FIGS. 1 to 6.

In FIGS. 1 to 6, the top layer A is a part (1 part) of the package.
The uppermost layer of a multi-layered sheet provided on the surface) is usually 5 to 100 μm thick, preferably 12 to 50 μm thick, and is made of polymethylpentene obtained by polymerizing 4-methylpentene-1.

For the production of polymethylpentene film, for example, a highly productive extrusion lamination method can be applied. This material has excellent gas permeability, about 10 times more permeable to oxygen and carbon dioxide than polyethylene or polypropylene fill.

Next, the middle layer B preferably has a Gurley air permeability of 1000.
Although it is convenient to use paper with a flow rate of 100 ml or less, a nonwoven fabric with a plastic ring or a microporous membrane with a plastic ring may also be used. That is, the paper may be Japanese paper, Western paper, synthetic paper, plastic mixed paper, etc., and the nonwoven fabric may be plastic fibers such as polyethylene, polypropylene, polyester, or nylon, which are bonded into a sheet shape using heat, pressure, adhesive, etc. can be used.

A specific example is Tyvek (manufactured by DuPont, USA)
, Brasslon (Nitto as a monarchy), Spanpond (Asahi Kasei)
), etc. Alternatively, a perforated plastic film may be used.

Examples of microporous membranes include those obtained by methods such as cold stretched films of polyethylene or polypropylene resins, stretching of foreign matter-containing films, and irradiation with electron beams. Specific examples include Hibore (Asahi Kasei ■), Microtex (
Nitto Denko ■), NF sheet (Tokuyama Soda ■), etc.

When the middle layer B is made of paper as described above, or a plastic nonwoven fabric or microporous membrane that does not have a heat-sealing function or has an inferior heat-sealing function, it is preferable to provide a lower layer C.

The lower layer C usually has a lower softening point than the plastic that makes up the middle layer B, and has a Gurley air permeability of 1000 seconds/100.
It is composed of a heat-sealable perforated plastic film, non-woven fabric, or microporous plastic membrane with a size of 1 m or less. Specific examples of the perforated plastic film include films made of materials such as polyethylene, polypropylene, polyethylene vinyl acetate copolymer, or polyethylene ionomer. Methods for preparing a sheet by laminating these uppermost, middle, or lower layers include the Extru-Silon lamination method, which is commonly used when preparing laminates, a dry method or wet lamination method using emulsion or latex, A hot melt lamination method or the like is used. An anchor coating agent may be used in combination with these methods.

The package of the present invention can be obtained by laminating the top layer A, the middle layer B, and the bottom layer C in the order of AB or ABC to obtain a sheet, and then stacking two sheets and sealing them on all sides. Alternatively, the obtained sheet may be folded in two and sealed on three sides. Alternatively, the package of the present invention may be obtained by sealing the obtained sheet and a sheet D not particularly specified on all sides.

It is also possible to protect the package by laminating a porous film that does not inhibit gas permeability on the surface of the polymethylpentene film that is the uppermost layer of the package.

Gases that can be permeated through the packaging of the present invention include oxygen, carbon dioxide, nitrogen, ethylene, alcohol vapor, fragrances such as orange oil vapor, camphor vapor, water vapor, etc., and vaporizable insect repellents, pest attractants, and repellents. etc.

The packaging of the present invention has the following features: (1) The softening point of polymethylpentene is higher than that of general-purpose polyethylene and polypropylene (therefore, there is less fusion, etc. during heat sealing), and high-speed filling of contents is possible.

(2) It has high transparency and can be printed on the back side.

(3) Sufficient gas permeability (no treatment to increase gas permeability such as hole punching is required. Also, extrusion lamination onto paper, etc. is possible, resulting in high productivity.

(4) Water resistant, moisture resistant, and oil resistant. Can be used for handling hard and humid foods. Also, there is little seepage from the contents. Therefore, it is safe to use in food.

It has the following features. Another feature of the package of the present invention is that the permeation rate of the permeable gas can be adjusted by varying the thickness of the top layer of polymethylpentene between 5 and 100 μm.

The package of the present invention is used to contain an absorbent or generator for oxygen, carbon dioxide, or ethylene gas, an alcohol generator, a moisture absorbent, an attractant or repellent for termites, mites, cockroaches, etc., an insect repellent, and a fragrance. It is used as a package for preparing disposable hand warmers or as a package for preparing disposable body warmers.

EXAMPLES The present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these examples.

Example 1 Characters were printed on polyethylene nonwoven fabric (Spunbond H-5030 manufactured by Asahi Kasei), and polymethyl pentene (
TPX (manufactured by Mikata Petrochemical) was extrusion laminated to a thickness of 25 μm to obtain a sheet having a two-layer structure. This sheet was folded in half with the polymethylpentene film side on the outside, and an iron powder-based oxygen scavenger (Modulan 5250 (manufactured by Nippon Kayaku)) was used.

and sealed on three sides. This and the oxygen detector Type V (manufactured by Nippon Kayaku) were packaged with an oxygen-impermeable KON (stretched nylon chloride/dencoat) film with a volume of 250 ml. When observed after being allowed to stand for 18 hours at 25° C. and 33% humidity, the color of the oxygen detection agent changed from blue to red. Oxygen meter (
When the oxygen concentration in the outer bag was measured using Toshi Co., Ltd., it was 0.0.
It was 5%. It was shown that the oxygen in the outer bag was absorbed by the oxygen scavenger through the polymethylpentene film.

The package containing the oxygen scavenger did not contain polymethylben.

When the outer bag was left standing at 25° C. and 100% humidity for 18 hours and observed, the same results as above were obtained. Also, no leakage of the contents (oxygen scavenger) or contamination of external moisture was observed.

Application Example 1 The contents of a commercially available disposable body warmer (Hora Cairo, manufactured by Yamamoto) were heat-sealed and packaged in the sheet obtained in Example 1 whose top layer was polymethylpentene and whose bottom layer was a polyethylene nonwoven fabric.

When placed in a clothes pocket and observed, the temperature was maintained at 40 to 70°C for 12 hours. Furthermore, even when water was applied, no penetration into the interior was observed.

Application example 2゜A fragrance (
Orange oil dissolved in alcohol and impregnated with silica gel) was loaded and heat-sealed. It was observed that the scent penetrated through the packaging material and gave off an orange odor.

Example 2 Polyethylene nonwoven fabric (40g/cm2) was added to Japanese paper (40g/cm2)
Spunbond 5020 (manufactured by Asahi Kasei) was laminated by thermocompression, and 25 μm of polymethylpentene was applied to the Japanese paper surface.
A sheet having a three-layer structure was obtained by extrusion lamination to a thickness of .

With the polymethylpentene side of the obtained sheet facing outward,
An alcohol generator (impregnated with 2 g of silica gel and 3 g of alcohol) was placed and sealed on all sides to a size of 4 cm x 5 cm. When this was left at 25°C for 20 hours, an alcohol odor was constantly emitted and the weight of the alcohol-containing silica gel decreased to 4.25 g, indicating that alcohol had permeated through it.

The alcohol generating agent-containing package obtained above was placed in a commercially available Palmkuchen bag in a KON bag and stored at room temperature for 30 days. The Baumkuchen had no mold or other growth and remained sufficiently fresh. Also, no oil or fat content was observed to penetrate into the package.

Application Example 3゜A sheet with a three-layer structure obtained in Example 2, consisting of the top layer of polymethylpentene, the middle layer of Japanese paper, and the bottom layer of polyethylene nonwoven fabric, was used as the top surface, and a polyethylene nonwoven fabric (Tyvek, Dupont) was used as the top surface. ) was used as the bottom surface, and Modeleran W (oxygen absorber, manufactured by Nippon Kayaku Co., Ltd.) (contents only) was packed therein, and the four sides were heat-sealed to obtain a package containing the oxygen absorber.

The package containing the oxygen absorber 6 obtained above and the oxygen detector type G (manufactured by Nippon Kayaku) were placed in a commercially available bag containing cheese cod and sealed.

After 18 hours at room temperature, the oxygen detection agent changed color from blue to red, indicating that oxygen was decreasing. The oxygen concentration in the outer bag at this time was 0.02%.

Application example 4゜A mixture of 2.5 g of sodium hydrogen carbonate and 2.5 g of citric acid was packaged using a sheet with a two-layer structure obtained in Example 1 with three sides sealed to a size of 5 cm x 5 cm. . Calcium chloride Ig/100ml
When it was submerged in the liquid and observed day and night, the liquid was cloudy.

Application Example 5 The sheet obtained in Example 1 was filled with a de-ethylenizer pipe (manufactured by Nippon Kayaku) and packaged with three-side seals.

Place this in a paper box containing 2 Yubari melons and cover with a lid.
Stored for a week. No rot was observed on the melons.

Effects of the Invention A packaging body with high gas permeability was obtained without requiring any special perforation treatment or microporous treatment. This package is water and oil resistant and suitable for high-speed filling.

[Brief explanation of drawings]

In Figures 1 to 6, A...Mogami M (polymethylpentene film)
B... Middle layer (paper, non-woven fabric, etc.) C...
Lower layer (nonwoven fabric, etc.) D...Film or sheet E...Indicates the contents (medicine), respectively. Figure 1 Figure 2 Δ Figure 3

Claims (1)

[Claims] 1. A gas-permeable packaging body, in which all or part of the packaging body is made of a sheet having a multilayer structure, and the uppermost layer of the sheet having a multilayer structure is a polymethylpentene film.