JPH0716976A - Freshness preservation sheet and storage container using the same - Google Patents

Abstract

(57) [Summary] [Purpose] There is little deterioration in the freshness-keeping effect over time, and the occurrence of irritating odors during work is reduced as much as possible, so that a comfortable working environment and a stable freshness-keeping effect can be obtained at the same time. Provide a sheet for keeping freshness. In addition, a freshness preservation sheet suitable for automatic packaging is provided. [Structure] An isothiocyanate ester hardly permeating film layer hardly permeating, a freshness retaining layer containing isothiocyanate ester formed on the hardly permeating film layer, and on the freshness retaining layer. A freshness-maintaining sheet that is formed and is provided with an easily-permeable film layer that is easily permeated by isothiocyanate vapor, wherein the entire freshness-keeping sheet is wound so that the film layer that is difficult to permeate is on the outside. It is shaped like a roll, and is configured to be used in a state in which it is cut from a rolled form into a sheet-like form when used.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a freshness-retaining sheet having a freshness-retaining layer containing an isothiocyanate ester for the purpose of preventing mildew, bacteriostatic and sterilizing of fresh foods and processed foods during distribution and storage, and The present invention relates to a storage container using the same.

[0002]

2. Description of the Related Art Wasabi has long been known to have an antiseptic effect, and isothiocyanate, which is a pungent component, is said to have an effect of preventing fermentation and spoilage comparable to benzoic acid.

Further, it is already known to pay attention to the antibacterial property of isothiocyanic acid ester and to use it to maintain the freshness of foods. That is, for example, Japanese Patent Laid-Open No. 2-11
Japanese Patent No. 3876 discloses a freshness-retaining agent in which a clay mineral containing an isothiocyanic acid compound is packaged with a packaging material whose volatilization amount is controlled.

[0004]

However, the freshness-retaining agent disclosed in this article is a packing material impermeable to isothiocyanate which is made up of several to several tens in advance due to the mechanism of keeping the freshness. It takes the form of packaging with a pouch. Therefore, it is necessary to collectively store the food in the pouch until just before the food packaging work.

Therefore, it is necessary to open the pouch just before the food packaging work, take out the freshness-retaining agent one by one from the pouch and enclose it with the food, which causes a problem that the packaging work is extremely busy and complicated. there were.

Further, since the isothiocyanate ester starts to volatilize at the same time as the opening of the isothiocyanate-impermeable pouch, the freshness-preserving effect, that is, the remaining amount of the isothiocyanate ester depends on the time from opening, and the pouch first starts. There is also a problem that the freshness-keeping agent taken out and the lastly taken-out freshness agent have slightly different effects and the freshness-keeping effect becomes unstable.

Further, when opening the impermeable pouch,
Since the isothiocyanic acid ester vapor stored inside the pouch is released at one time, the irritating odor during the packaging work process was severe, and the deterioration of the work environment was also a problem. Further, it is also required to have a sheet form suitable for automation of packaging.

The present invention was devised on the basis of such an actual situation, and the object of the present invention is not only to maintain the quality (freshness) of foods that are originally the subject of quality preservation, but also to maintain the freshness over time. Another object of the present invention is to provide a freshness-retaining sheet which is less likely to deteriorate and has a stimulating odor during work reduced as much as possible, and which can simultaneously provide a comfortable working environment and a stable freshness-retaining effect. Another object is to provide a freshness-preserving sheet suitable for automation of packaging.

[0009]

As a result of various researches conducted by the present inventors in order to solve such problems, as a result, the structure of the freshness-keeping sheet is set to a non-permeable film in which isothiocyanate vapor is difficult to permeate. A laminate structure comprising a layer, a freshness-retaining layer containing an isothiocyanate ester formed thereon, and an easily permeable film layer formed with an isothiocyanate vapor that easily permeates therethrough. It is found that the above-mentioned problems can be solved by using a rolled form until the time of use, and in using, by using a form in which the sheet portion unwound from the rolled form can be arbitrarily cut and used. Then, the present invention was conceived.

That is, according to the present invention, a hardly permeable film layer in which isothiocyanate ester vapor hardly permeates, a freshness-maintaining layer formed on the hardly permeable film layer and containing an isothiocyanate ester, A freshness-retaining sheet formed on a freshness-retaining layer, comprising an easily permeable film layer through which isothiocyanate vapor easily permeates. In this case, the rolled form is formed so that the rolled form is cut out into a sheet shape before use.

Further, the storage container of the present invention is a container for packaging the freshness-retaining sheet, which is unwound from a wound form, in a state of being cut into a sheet shape and the food to be kept fresh. It was configured to be stored inside.

In the storage container of the present invention, a freshness-retaining sheet unwound from a rolled form, cut into a sheet, is incorporated as a part or all of the packaging container,
It was configured to store the foods to be kept fresh in this.

[0013]

The freshness-keeping sheet of the present invention has a wound form as a normal form before use, so that outflow of isothiocyanate ester vapor from the freshness-keeping layer is suppressed. Then, in use, the freshness-retaining sheet unwound from the wound form is used in a state of being cut into a sheet shape, so the isothiocyanate ester vapor emitted from the freshness-retaining layer is easily permeable. It permeates the film layer and flows out into the external atmosphere. further,
Since the freshness-keeping sheet is unrolled from the rolled form, it can be easily adapted to packaging automation.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The freshness keeping sheet of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a plan view of the freshness-retaining sheet in a rolled form before use, that is, a form after winding a long sheet as shown in FIG. FIG. 2 shows a cross-sectional view for explaining the laminated structure of the freshness keeping sheet. The sectional view of FIG. 2 basically corresponds to the sectional view of the partially enlarged sheet portion (the portion surrounded by a circle) of FIG.

As shown in these figures, the freshness-maintaining sheet 1 is formed on a film layer 3 which is hardly permeable to isothiocyanate ester vapors and which is difficult to permeate, and on the film layer 3 which is hardly permeable, The freshness-retaining layer 5 containing an isothiocyanate ester is provided, and the easily-permeable film layer 7 formed on the freshness-retaining layer 5 is easily permeable to the vapor of the isothiocyanate ester.

Examples of the packaging material for the impervious film layer 3 include polyester film, polyamide film, polyacrylonitrile film, polyvinylidene chloride film, polyvinylidene chloride coat film, saponified ethylene-vinyl acetate copolymer film. , Polyvinyl alcohol film, aluminum foil, aluminum vapor deposition film,
An inorganic vapor deposition film (for example, a film obtained by vapor-depositing an inorganic substance such as Al ₂ O ₃ or SiO _x on a film) may be used. The thickness is 10-100
It is about μm.

The freshness-keeping layer 5 formed on such a poorly permeable film layer 3 contains an isothiocyanate ester as described above, and an adhesive is usually used to contain this. To be

As the isothiocyanic acid ester, various aliphatic and aromatic isothiocyanic acid esters are used. Among them, isothiocyanic acid ester (CH ₂ = CHCH ₂ NCS) and isothiocyanic acid alkyl ester (RNCS, R: alkyl group) is used.

In the present invention, as a simple method, mustard oil can be used as it is or in the form of being dissolved in an oily liquid.

The pressure-sensitive adhesive containing such an isothiocyanate ester is not particularly limited, but, for example, a solvent-type pressure-sensitive adhesive, a solventless pressure-sensitive adhesive or the like is used.

As the solvent-type pressure-sensitive adhesive, for example, natural rubber-based, styrene-butadiene rubber-based, polyisobutylene-based, isoprene-based rubber-based pressure-sensitive adhesives, and acrylic-based or silicone-based pressure-sensitive adhesives can be used.

As the solventless adhesive, for example,
Acrylic emulsion type, natural rubber latex type, styrene-butadiene latex type emulsion adhesive, styrene-isoprene block copolymer system, styrene-butadiene block copolymer system, styrene-ethylene-butylene block copolymer system, ethylene-vinyl acetate Thermoplastic elastomer-based hot-melt adhesives, natural rubber-based, reclaimed rubber-based, butyl rubber-based calendaring-type adhesives, water-soluble adhesives, liquid curable adhesives and the like can be used.

The content of the isothiocyanic acid ester contained in such a pressure-sensitive adhesive may be appropriately determined depending on its freshness-retaining effect and the freshness-retaining period, but as a standard for setting, it is 0.1 per sheet for freshness-keeping. It is particularly preferable that the pressure-sensitive adhesive contains it in the range of ˜100 mg.

When the content of this isothiocyanate is less than 0.1 mg, the amount of isothiocyanate vapor generated is small and the effect of keeping freshness cannot be expected. On the other hand, the content of isothiocyanate is 100 mg.
Even if the amount exceeds 100 mg, the freshness-retaining effect does not increase, and using more than 100 mg is not economical.

The thickness of the freshness-retaining layer 5 containing such an isothiocyanate ester is usually about 1 to 50 μm.

As the easily permeable film layer 7 formed on the freshness keeping layer 5, for example, a polyethylene film, an ethylene-vinyl acetate copolymer film,
One or more films selected from polypropylene film, polystyrene film, ionomer film, vinyl chloride film, polybutadiene film, polymethylpentene film, or a bonded product of one or more of these films and a breathable packaging material Can be mentioned. Here, as the breathable packaging material, one or more kinds of paper, non-woven fabric, plastic film subjected to fine communication processing, and plastic film subjected to stretching processing by adding an inorganic filler are preferable.

The thickness of the easily permeable film layer 7 is usually about 10 to 100 μm.

As shown in FIG. 3, the laminated body thus laminated is wound up with the hardly permeable film layer 3 side being the outside (the easily permeable film layer 7 is the inside) to be wound up according to the present invention. A sheet 1 for keeping freshness is formed (FIG. 1). By the storage in the wound form, generation of isothiocyanate vapor is suppressed through the easily permeable film layer 7 until it is unwound and used.

Such a freshness-maintaining sheet 1 is usually
It is used in a state in which a sheet portion unwound from a wound form is cut into a sheet having an appropriate length. That is, the cut freshness-maintaining sheet 1 (FIG. 2) is immediately stored in the packaging container 50 together with the food 20 to be stored (the entire product as shown in FIG. 4). Is referred to as a storage container 40).

Then, the isothiocyanic acid ester vapor emitted from the freshness-keeping layer 5 of the freshness-keeping sheet 1 permeates the easily permeable film layer 7 and gradually comes out into the packaging container 50, and at the same time, the packaging is performed. Fill the outer bag 50,
As a result, the antibacterial action on the food 20 works and the freshness of the food is maintained.

The form of the packaging container 50 is a pouch shape, a tray + film shape, a tray + lid material shape, a tray + wrap film shape, a tray + lid material + wrap film shape, a paper carton shape, Etc., and any other form is possible.

Further, as shown in FIG. 4, a part or all of the packaging container 50 can be used as a packaging material for adjusting the isothiocyanate vapor concentration. This figure is an example in which one packaging material 53 is a film having a low permeability to isothiocyanate ester vapor and the other film 51 is a film for adjusting the isothiocyanate ester vapor concentration.

Here, the packaging material for adjusting the isothiocyanate vapor concentration is, for example, a film or sheet of a material that easily adsorbs isothiocyanate vapor, a film or sheet that easily transmits isothiocyanate vapor, and the like. To be In addition, it is naturally possible to provide a communication hole in a part of the packaging container 50 or to provide a gap between the tray and the lid member in order to let the isothiocyanic acid ester vapor flow out of the packaging container 50.

With such a structure of the packaging container 50, the concentration of the isothiocyanate ester in the packaging container 50 can be adjusted (particularly when the concentration is excessive).

The adjustment and setting of the isothiocyanic acid ester vapor concentration is preferably carried out under the following conditions. First, as a measure of the effect of maintaining freshness, a packaging container 50 that does not enclose the contents (food 20) is used, and the isothiocyanate concentration in the container is 5 pp within 48 hours.
m (V / V) or more, the maximum value is 10 ppm (V / V)
Set so that it is above. Here, the space (air volume) of the packaging container 50 needs to be the same as when the food 20 is enclosed. Also, as a measure of the wasabi odor when opening,
10 ppm within 480 hours with food enclosed
The value is set to (V / V) or less.

The above isothiocyanate ester concentration is adjusted and set by appropriately selecting the void ratio, the container area, the container material, the isothiocyanate ester content in the freshness-keeping layer 5 of the freshness-keeping sheet, and the like.

Here, a packaging container 50 which does not enclose the contents
Isothiocyanate concentration within 5 hours within 5 hours
If the concentration does not reach ppm (V / V) or higher, the microorganisms may grow before the freshness-retaining effect is exhibited, which is not preferable. Further, if the maximum value of the isothiocyanate concentration is less than 10 ppm (V / V), the effect of suppressing the growth of microorganisms is diminished, and the effect of maintaining freshness cannot be expected, which is not preferable.

Further, the concentration of isothiocyanate in the packaging container 50 enclosing the contents is 10 within 480 hours.
If the concentration is not lower than ppm (V / V), the odor of horseradish at opening may cause a problem, which is not preferable.

Here, the setting of the concentration of the isothiocyanate ester relating to the freshness-retaining effect is based on an empty container in which the contents are not enclosed, because the adsorption amount of the isothiocyanate ester differs depending on the contents (food 20). This is because the transition of the isothiocyanate concentration below cannot serve as a standard. The packaging container 50 that stores the food 20 and the freshness maintaining sheet 1 form a storage container 40 that is a product.

Of course, the packaging container may be an ordinary packaging container which does not have the function of adjusting the isothiocyanate concentration.

Further, the forming material inside the packaging container 50 is made of a film or sheet of a material which easily adsorbs isothiocyanate vapor, and the forming material outside thereof is made of an oxygen barrier film or sheet, whereby an oxygen barrier is formed. The effect is added. In this case, it is possible to fill the packaging container 50 with an oxygen absorber or fill it with an inert gas.

Further, the freshness-keeping sheet 1 can be used as a lid member as shown in FIG. 5 depending on the cutting specifications, and can be incorporated as a part of a container. That is, FIG. 5 shows a container 40 ′ obtained by cutting the freshness-keeping sheet 1 unrolled from the wound shape into an upper lid shape and heat-sealing the upper opening of the container body 15 as a lid.

In this case, the freshness keeping sheet 1 forming the lid is set so that the easily permeable film layer 7 is located inside the container. This is because the container is filled with isothiocyanate vapor and the freshness of the food 20 contained therein is maintained.

By incorporating the freshness preservation sheet 1 as a part of the container in this manner, it is not necessary to enclose a so-called preservative (including the cut freshness preservation sheet) in the container. There is no risk of accidental ingestion of preservatives. Further, FIG. 7 shows a so-called pillow packaging form in which the freshness preservation sheet 1 is incorporated as a part of a container. This pillow packaging container 4
0 "indicates that the freshness-keeping sheet 1 unwound from the wound state is simultaneously supplied onto the food packaging film 60 conveyed in the longitudinal direction as shown in FIG. 6 and cut into arbitrary lengths. The end portion 63 is heat-sealed in a pillow shape, and in this case, the food packaging film 60 and the freshness-keeping sheet 1 are heat-sealed in a state in which the end portions overlap each other, so that the inside of the container 40 ″ is kept fresh. The holding sheet 1 does not move freely. Also in this case, similarly to the case shown in FIG. 5, the easily permeable film layer 7 is set so as to be located inside the container, and there is no risk of accidental ingestion of the preservative. Further, FIG. 8 shows a modification of the pillow packaging form. In this case, the end portion 63 is once heat-sealed, and the remaining two openings are heat-sealed, whereby the freshness-keeping sheet 1 is integrated with the packaging container.

The present invention will be described in more detail below by showing concrete experimental examples. Experimental Example 1 An isothiocyanate-containing pressure-sensitive adhesive (freshness retaining layer composition) was prepared with the following composition.

2-ethylhexyne acrylate 75 parts by weight-methyl acrylate 18 parts by weight-maleic anhydride 1.5 parts by weight-hexamethylenediamine 0.5 parts by weight-isothiocyanic acid allyl ester 5 parts by weight-ethyl acetate 300 parts by weight Part Such an adhesive was applied on a polyethylene terephthalate film (impermeable layer 3) having a thickness of 50 μm at a rate of 50 g / m ^{2 in} terms of solid matter to form a freshness keeping layer 5.

Then, on the freshness keeping layer 5, an easily permeable film layer 7 made of polyethylene (thickness: 30 μm)
After being adhered to each other, they were wound into a roll to form a sheet for keeping freshness. A freshness-retaining sheet 1 that is cut out while feeding out a sheet portion from such a wound sheet and cutting the sheet to a size of 80 mm × 50 mm
Immediately, cut rice cake (thickness 15 mm, width 40 mm, length 60 mm) in a pouch (packing container 50) made of drawn nylon (thickness 15 μm) / polyethylene (thickness 30 μm) of size 200 mm × 300 mm. The packaging work for enclosing the storage container 40 together with 10 pieces was actually performed. According to this packaging operation, since the freshness retaining effect from the freshness retaining layer 5 is not exhibited until the sheet portion is unwound from the rolled sheet, deterioration of the freshness retaining effect with time is small, and at the time of the work. It was confirmed that the irritating odor of was also significantly reduced.

Furthermore, when the storage container 40 containing the freshness-keeping sheet 1 was stored at 30 ° C. for 1 year, no odor was transferred to the rice cake and there was no spoilage by microorganisms such as mold, and the original taste of the rice cake was obtained. It was also confirmed that was maintained. In addition, the rolled freshness keeping sheet 1 of the present invention
Was confirmed to be suitable for automatic packaging.

[0050]

EFFECT OF THE INVENTION The freshness-preserving sheet of the present invention comprises a film layer of hardly permeating isothiocyanate vapor that hardly permeates an isothiocyanate ester vapor, and a freshness film containing isothiocyanate ester formed on the hardly permeating film layer. A freshness-retaining sheet comprising a holding layer and a film layer formed on the freshness-keeping layer and having an easy permeability for isothiocyanate ester vapor to pass through, wherein the freshness-keeping sheet as a whole is hardly permeable. It has a roll shape so that the film layer is on the outside, and when used, it is configured to be used in the state of being cut out from the roll shape into a sheet shape, so that the freshness is maintained with time. The effect is less deteriorated, and the irritating odor during work is significantly reduced. Thereby, a comfortable working environment and a stable freshness keeping effect can be obtained at the same time. It is also suitable for automation of packaging.

[Brief description of drawings]

FIG. 1 is a plan view of a wound form of a freshness preservation sheet of the present invention before use.

FIG. 2 is a cross-sectional view for explaining the laminated structure of the freshness preservation sheet of the present invention.

FIG. 3 is a cross-sectional view for explaining a winding state of the freshness keeping sheet of the present invention.

FIG. 4 is a cross-sectional view showing a state in which the cut freshness-keeping sheet of the present invention is stored in a packaging container together with food.

FIG. 5 is a schematic cross-sectional view of a container in which a freshness-keeping sheet is heat-sealed as a lid at the upper opening of the container.

FIG. 6 is a perspective view showing a sheet-like arrangement before forming a so-called pillow packaging form, using the freshness keeping sheet as a part of a container.

FIG. 7 shows a freshness-retaining sheet used as a part of a container,
It is a perspective view of what is called a pillow packaging form.

FIG. 8 shows a freshness keeping sheet used as a part of a container,
It is a perspective view which shows the other modification of what is called a pillow packaging form.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Freshness preservation sheet 3 ... Hardly permeable film layer 5 ... Freshness retention layer 7 ... Easy-permeable film layer 20 ... Food 40 ... Storage container 50 ... Packaging container

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B65D 81/28 C 9028-3E 85/50 A 7191-3E

Claims (5)

[Claims] 1. A hardly permeable film layer through which isothiocyanate vapor hardly permeates, a freshness-keeping layer formed on the hardly permeable film layer and containing isothiocyanate, and a freshness-keeping layer comprising: A freshness-maintaining sheet formed on the above-mentioned sheet, which comprises an easily permeable film layer through which isothiocyanate vapor is easily permeable, wherein the film layer that is difficult to permeate is outside as a whole of the freshness-keeping sheet. A freshness-retaining sheet, which has a rolled form and is used in a state of being cut out from the rolled form into a sheet shape when used. 2. The hardly-permeable film layer is a polyester film, a polyamide film, a polyacrylonitrile film, a polyvinylidene chloride film, a polyvinylidene chloride coat film, a saponified ethylene-vinyl acetate copolymer film, or a polyvinyl alcohol film. ,
It contains at least one kind of aluminum foil, aluminum vapor deposition film and inorganic vapor deposition film, and the easily permeable film layer is polyethylene film, ethylene-vinyl acetate copolymer film, polypropylene film, polystyrene film, ionomer film. 2. One or more films selected from a vinyl chloride film, a polybutadiene film, a polymethylpentene film, or a bonded product of one or more of these films and a breathable packaging material. Sheet for keeping freshness. 3. The breathable packaging material is one of paper, non-woven fabric, a plastic film that has been subjected to fine communication processing, and a plastic film that has been stretched by adding an inorganic filler.
The freshness-preserving sheet according to claim 2, wherein the sheet is one or more kinds. 4. A freshness-keeping sheet unwound from the rolled form according to claim 1 is cut into a sheet shape, and the freshness-retaining sheet and the food to be kept fresh are stored in a packaging container. A storage container characterized by the above. 5. A freshness-retaining sheet unwound from the rolled form according to claim 1 cut into a sheet shape is incorporated as a part or the whole of a packaging container, and a food to be freshness-retained is contained therein. A storage container characterized by being stored.