JPH0754138Y2 - Aseptic plastic packaging - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a plastic packaging container for lunch boxes, dishes, bowls, and cups, and in particular, to keep the inside of the plastic packaging container semipermanently in an aseptic state. The invention relates to a plastic aseptic packaging container.

[Conventional technology]

A conventional plastic packaging container for lunch boxes, dishes, bowls, and cups is usually formed by secondary molding a sheet obtained by extrusion molding a thermoplastic resin with an extruder. In addition, this plastic packaging container is made by adding a foaming agent and a nucleating agent to a thermoplastic resin, for example, polystyrene, in order to enhance the heat retaining function, to form a mixture, and the mixture is put into an extruder and extruded under heat and pressure. It is made by secondary molding of the foam obtained by extruding into the low-pressure zone from the die attached to. Plastic packaging containers made of these thermoplastic resin sheets and foams have passed the PL standard for some time, but do not have antibacterial properties, so due to bacteria during transportation and storage of these plastic packaging containers. Due to possible contamination, it is necessary to thoroughly wash and sterilize the plastic packaging containers when packing foods in these plastic packaging containers for hygiene management.

By the way, generally, various food freshness preservation methods can be considered, but first, when the concept of food freshness preservation is arranged, (a) the spoilage of the food itself is prevented. That is, various preservatives are directly added to foods to prevent sterilization and breeding.

(B) Try not to spoil the flavor and taste. For example, preventing rancidity of fats and oils.

(C) Prevent color deterioration. For example, prevent ultraviolet rays.

(D) For living organisms, removal of aging-promoting substances. For example, adsorption with ethylene gas.

Etc.

It goes without saying that the most primitive method of keeping food freshness is preservation at low temperature (prevents bacterial growth), and the reverse contrast is retort (sterilization at high temperature). Further, with the progress of plastic processing technology, methods such as vacuum packaging, gas displacement ageless, use of antimold, etc. have been developed one after another, and the direction is now moving toward aseptic filling.

Therefore, it is becoming more important that these plastics are always sterilized, and recently, an antibacterial agent that exerts its effect by mixing it in plastics (resin, film and sheet) or applying it on the surface. , Many antifungal agents and bactericides have been developed, and some of them are on the market.

[Problems to be solved by the invention]

However, a plastic packaging container using plastic as a material having an antibacterial and bactericidal effect by mixing an antibacterial agent into these plastics or applying them on the surface is, for example, an elution type and is eluted from these plastics. Since the antibacterial property is exerted by the antibacterial agent and the like, the taste of food may be changed. Further, although the temperature reaches 250 ° C. or higher due to the processing of plastics, conventional antibacterial agents, especially organic ones, decompose and the antibacterial effect is diminished. Furthermore, in order to obtain the prescribed antibacterial and sterilizing power, a considerable amount, for example, 2.5% or more of the added amount is necessary with respect to the weight of the plastic. , The physical properties inherent in plastic are impaired. That is, transparency, slip properties, heat seal strength, breathability, etc. are affected,
Problems arise in its workability.

Due to the above-mentioned problems, plastic packaging containers in which an antibacterial agent is mixed into these plastics or plastics as a material coated on the surface are rarely used. For this reason, each food manufacturer is currently forced to make a large investment to maintain the hygienic condition of food, and make efforts to improve processing machinery, install a sterile room, etc. according to the scale. There is. As a part of this, even with respect to plastic containers for packaging foods brought in from the outside, that is, these foods directly, a great deal of investment is required for equipment for cleaning and sterilization. In some cases, the sanitary condition is left to the other party and an unprotected case may be considered. That is, even if these plastic packaging containers are aseptic at the time of shipping, there is a problem that they may be contaminated at the time of transportation and storage.

Therefore, the present invention has been made in view of the above circumstances, and can exhibit antibacterial properties without elution of antibacterial agents, etc., and the antibacterial components do not decompose even at the temperature required for plastic processing, and the addition amount It is an object of the present invention to provide a plastic aseptic packaging container which requires less amount, has a long-term antibacterial property, and is easily processed.

[Means for solving problems]

In order to solve the above problems, the plastic aseptic packaging container of the present invention comprises a plastic packaging container for a lunch box, a dish, a bowl, and a cup, which is mainly made of a thermoplastic resin and an antibacterial zeolite. A multilayer sheet is prepared by fusing or adhering at least one thermoplastic resin sheet to a sheet having the antibacterial zeolite in the range of 0.1 to 5% by weight based on the total weight of the resin.

[Action]

According to the above configuration, since the inner surface of the plastic packaging container is composed of the multilayer sheet or the foam containing the antibacterial zeolite, the antibacterial zeolite adheres to the inner surface of the plastic packaging container by the ions having the bactericidal action. It can kill the existing microorganisms, keep the inner surface of the plastic packaging container in a sterile condition, and also keep it warm and cool.

[Embodiment] An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a perspective view of a plastic aseptic packaging container of the present invention, and FIG. 2 is a sectional view showing a multilayer sheet. In both figures, 1 denotes a plastic aseptic packaging container (hereinafter, simply referred to as an aseptic container), and the aseptic container 1 comprises a container body 2
And a lid body 3 formed integrally with the container body 2.

The container body 2 is composed of a multi-layer sheet 9 containing antibacterial zeolite 6, and the multi-layer sheet 9 is formed into a rectangular lunch box shape. The wall thickness of the container body 2 has a slight thickness in consideration of rigidity and heat retention.

As shown in FIG. 2, the multilayer sheet 9 of the container body 2 is mainly composed of a thermoplastic resin 5 and an antibacterial zeolite 6, and the antibacterial zeolite 6 is contained in an amount of 0.1 to 5 parts by weight based on the total weight of the thermoplastic resin 5. % Range, and 0.03 mm ~
It may be a multi-layer sheet 9 in which at least one thermoplastic resin sheet 8 is fused or adhered to a sheet 7 having a thickness of 0.1 mm. With the sheet 7 containing the antibacterial zeolite 6 of the multilayer sheet 9 inside, a lunch box, a plate, a bowl, and a cup-shaped container body 2 are molded. Thus, the multilayer sheet 9
The reason for using is to impart antibacterial properties to the inner surface of the container body 2, and to reduce the amount of antibacterial zeolite 6 used and to reduce costs.

The thermoplastic resin 5 can be mixed with the antibacterial zeolite 6 and can withstand the characteristics required as a packaging container for lunch boxes, dishes, bowls, and cups, for example, low and high temperatures to some extent. Any material may be used as long as it has heat-retaining and cold-keeping properties, has a certain degree of rigidity, does not smell food, and is water-resistant and non-toxic.

The thermoplastic resin 5 is, for example, polystyrene, polyethylene, polypropylene, vinyl chloride, ABS resin, nylon, polyester, polyvinylidene chloride, polyamide,
Examples thereof include polyacetal, polyvinyl alcohol, polycarbonate, acrylic resin, fluororesin, polyurethane elastomer, polyester elastomer, rayon, cupra, acetate, triacetate, vinylidene, natural and synthetic rubber.

Of these, polystyrene (PS), polyethylene and polypropylene are most suitable.

The antibacterial zeolite 6 may be such that some or all of the ion-exchangeable ions of natural zeolite or synthetic zeolite are replaced with antibacterial metal ions, such as silver, copper and zinc. -181002 gazette).

That is, zeolite is generally an aluminosilicate having a three-dimensional skeleton structure, and the general formula is XM ² / _n O · Al ₂ O ₃ · Y
It is represented by SiO ₂ · ZH ₂ O. Here, M represents an ion-exchangeable ion, and is usually a monovalent or divalent metal ion, for example, each ion such as sodium, potassium, magnesium, and iron, n is a valence of a metal ion, and X is a metal oxide. Coefficient, Y is the coefficient of silica, and Z is the number of molecules of water of crystallization. The ion exchange capacity of the zeolite represented by the general formula XM ² / _n O ・ Al ₂ O ₃・ YSiO ₂・ ZH ₂ O is 2.6 ^meq / _g ~
11.5 ^meq / _g . Therefore, the antibacterial zeolite 6
The ion-exchangeable ions are antibacterial metal ions,
For example, it is replaced by silver, copper, zinc or the like. The antibacterial zeolite 6 contains 0.1 to 15% by weight of these antibacterial metal ions in the zeolite from the viewpoint of antibacterial property.
It is desirable that the content is approximately (indicated by weight% based on 110 ° C dry standard).

The antibacterial zeolite 6 may be a natural zeolite or a synthetic zeolite in which some or all of the ion-exchangeable ions are replaced with ammonium ions and antibacterial metal ions (Japanese Patent Application No. 61-290144). Of Priority Claim in Article 42-2, Paragraph 1 of the Japanese Patent Law
“To effectively prevent discoloration of the antibacterial zeolite 6” filed on April 4, the ammonium ion in the antibacterial zeolite 6 is preferably in the range of 0.5 to 2.0% by weight. From the viewpoint of substantially preventing discoloration, the content of the antibacterial zeolite 6 containing the ammonium ion is 0.1 to the thermoplastic resin 5.
It is preferably 3.0%.

In addition, the antibacterial properties, durability of antibacterial activity, heat resistance, and safety of these two kinds of antibacterial zeolite 6 are described in detail in these publications or application examples. That is, the antibacterial property has been reconfirmed by an antibacterial activity test as described below, and the antibacterial activity is maintained by continuously packing the antibacterial zeolite into a glass column having an inner diameter of 22 mm and a packed bed volume of 10 ml. And tap water in this column at 25-30 ml / m.
The antibacterial activity is maintained even in the antibacterial zeolite after water is passed at a flow rate of 5000 liters, and the durability of the antibacterial activity is semi-permanent. In addition, it can withstand heat up to 550 ° C, and has also passed safety tests such as antibacterial metal elution tests.

Further, as shown in FIG. 3, the multi-layer sheet 9 of the container body 2 is mainly composed of a foaming resin 5 ', an antibacterial zeolite 6, a foaming agent and a nucleating agent 10, and is based on the total weight of the foaming resin 5'. 0.1-5% by weight of antibacterial zeolite 6 and 5% of blowing agent
-15% by weight and nucleating agent 10 in the range of 0.1-5% by weight,
In addition, the foam 11 may be replaced with that formed. The foam 11 is particularly excellent in heat retention and cold retention and is lightweight. Polystyrene, polyethylene and ABS resin, for example, are used as the foaming resin 5 ', freon 12, butane, propane, pentane, etc. are used as the foaming agent, and nucleating agent 10 is, for example, talc, carbonic acid, etc. Calcium and clay are used.

The lid 3 is composed of a multilayer sheet 9 or a foam 11 containing the antibacterial zeolite 6 similarly to the container body 2, and its shape is also a prismatic lunch box shape with a slightly shallow bottom similar to the container body 2. It is molded. Since the lid 3 is similar to the container body 2 in other configurations, the description thereof will be omitted.

Next, a usage state of the aseptic container 1 having the above-mentioned configuration will be shown.

First, the aseptic container 1 stored with the lid 3 open and stacked is taken out, and food is put into the container body 2.
Next, the container body 2 containing the food is covered with the lid 3. At this time, since the inner surfaces of the container body 2 and the lid 3 of the aseptic container 1 that are stored in an overlapping manner have antibacterial properties, these are especially dusty,
If there is no dirt due to dust or the like, the inside of the aseptic container 1 is kept aseptic, so that it is not necessary to wash or sterilize the aseptic container 1, and the aseptic container 1 is kept as it is. You can put food in it. In addition, since the container body 2 and the lid 3 have a heat insulation property,
Food is hard to heat and hard to heat. In particular, when the container body 2 and the lid body 3 are made of the foamed material 11, it is possible to obtain a very high heat-retaining property and at the same time antibacterial property.

FIG. 4 shows another embodiment of the aseptic container 1 of the present invention. Only the shape is different, and other configurations and operations are the same as those of the embodiment of FIGS.

Next, the germicidal container 1 of the present invention is tested for antibacterial activity against Escherichia coli, Staphylococcus aureus, Salmonella, and Vibrio parahaemolyticus.

The test method is shown below.

1) Test strain Escherichia coli IFO 3301 (Escherichia coli) Staphylococcus aureus ATCC 6538P (Staphylococcus aureus) Salmonella typhimurium (Laboratory isolate) (Salmonella) Vibrio parahaemolyticus IFO 12711 (Vibrio parahaemolyticus) 2) Culture medium E. coli, yellow grape For cocci, Salmonella ...... 0.2% meat extract-containing normal agar medium For Vibrio parahaemolyticus …… 3% salt-containing, 0.2% meat extract-containing normal agar medium 3) Preparation of bacterial solution E. coli, Staphylococcus aureus, Salmonella bacterium; normal broth medium After culturing overnight at 37 ° C., it was prepared with sterile physiological saline so that the number of bacteria was 10 ^{4 to 5} per ml.

Vibrio parahaemolyticus; After culturing at 37 ℃ overnight in normal broth medium containing 3% sodium chloride,
It was prepared using sterile 3% saline so that the number of bacteria was 10 ^{4 to 5} per 1 ml.

4) Test operation Test piece of Example (4.8 cm x 4.8 cm) after washing with ethanol
A fixed amount of the bacterial solution was sprayed on one side of the test piece (4.8 cm x 4.8 cm) of the comparative example and stored at 37 ° C. After the start of storage 0 (immediately after spraying), 24 and 48 hours later, the surviving bacteria on the test piece were washed out with SCDLP liquid medium (Daigo Nutrition Chemistry), and the washing solution was subjected to a pour plate culture method using a medium for measuring the number of bacteria. (37 ° C
The number of surviving cells was measured for 2 days) and converted into the number of viable cells per one test piece. In addition, after dispensing the same amount of bacterial solution as sprayed on the test piece into a Petri dish, store it at 37 ° C and immediately after 2
The number of viable bacteria after 4 and 48 hours was measured and used as a target.

Example 1 Polystyrene (PS) with antibacterial zeolite 1.
A sample piece is made by adding and mixing 0% by weight.

Comparative Example 1 A sample piece is made of polystyrene (PS) only.

Table 1 shows the test results.

Example 2 A sample piece is prepared by mixing 1% by weight of antibacterial zeolite with high density polyethylene (HDPE).

Comparative Example 2 A test piece is made only from high density polyethylene (HDPE).

The test results are shown in Appendix-2.

Example 3 A test piece is prepared by adding 0.7% by weight of antibacterial zeolite to low density polyethylene (LDPE).

Comparative Example 3 A test piece is made only from low density polyethylene (LDPE).

The test results are shown in Appendix-3.

Example 4 A test piece is prepared by adding 1% by weight of antibacterial zeolite to polypropylene (PP) and mixing them.

Comparative Example 4 A test piece is prepared by using polypropylene (PP).

The test results are shown in Appendix-4.

Example 5 A test piece is prepared by adding 0.7% by weight of antibacterial zeolite to polypropylene (PP).

Comparative Example 5 A test piece is made of polypropylene (PP) only.

The test results are shown in Appendix-5.

[Effect of device]

As described above in detail, according to the plastic aseptic packaging container of the present invention, the microorganisms adhering to the inner surface of the plastic packaging container are killed by the ions having the bactericidal action in the antibacterial zeolite, and the plastic packaging container is killed. The inner surface of the can be kept sterile. Therefore, the structure is simple and the amount of antibacterial zeolite used can be reduced. Since it uses a multi-phase sheet or foam, it has excellent heat retention and cold retention. Further, even if the plastic packaging container is stored for a long period of time, the plastic packaging container can be kept in an aseptic state, the hygiene management of the plastic packaging container is facilitated, and dirt such as dust and dust is plastic packaging container. If you store the plastic packaging container so that it does not adhere to
When packing food in a plastic packaging container, it is not particularly necessary to clean and disinfect the plastic packaging container. Since the antibacterial substance does not elute or vaporize from the antibacterial zeolite unlike conventional bactericides, the taste of the food is changed by the antibacterial substance, and there is no toxicity due to the antibacterial substance, Antibacterial effect lasts for a long time (semi-permanently).

Further, since the antibacterial zeolite is strong against heat, it is not easily affected by heat, and its antibacterial effect is not diminished unless a temperature of 550 ° C. or higher is applied during the production of the packaging container.

Further, the amount of antibacterial zeolite added to obtain a predetermined antibacterial and sterilizing power may be small, and the processability is maintained without deteriorating the inherent physical properties of resin and the like, and its economic efficiency There is an effect that it can also retain the sex.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a perspective view of a plastic aseptic packaging container of the present invention, FIG. 2 is a cross-sectional view of a multilayer sheet, FIG. 3 is a cross-sectional view of a foam, and FIG. FIG. 4 is a perspective view showing another embodiment of the present invention. 1 ... Aseptic plastic packaging container 2 ... Container body 3 ... Lid 5 ... Thermoplastic resin 5 '... Foaming resin 6 ... Antibacterial zeolite 7 ... Sheet 8 ... Thermoplastic resin sheet 9 ... … Multilayer sheet 10 …… Nucleating agent 11 …… Foam

Continuation of the front page (56) Reference JP-A 61-205615 (JP, A) JP-A 61-174110 (JP, A) JP-A 62-216914 (JP, A) JP-A 56-54279 (JP , A) JP 62-132727 (JP, A) JP 58-99117 (JP, A) JP 58-199763 (JP, A) JP 58-116454 (JP, A) 60-62470 (JP, U) Actually open Sho 60-79433 (JP, U) Actually open 63-166906 (JP, U) Japanese Patent Sho 50-23400 (JP, B2)

Claims (6)

[Scope of utility model registration request] 1. A lunch box, a plate, a bowl, and a cup-shaped plastic packaging container whose inner surface is mainly composed of a thermoplastic resin and an antibacterial zeolite, and the antibacterial zeolite is 0.1 to the total weight of the thermoplastic resin. A plastic aseptic packaging container, characterized by comprising a multi-layered sheet in which at least one thermoplastic resin sheet is fused or adhered to a sheet in the range of 5 wt%. 2. The plastic aseptic packaging container according to claim 1, wherein the thermoplastic resin is one thermoplastic resin selected from polystyrene, polyethylene and polypropylene. 3. The utility model registration claim in which the antibacterial zeolite has a part or all of the ion-exchangeable ions in the zeolite replaced with antibacterial metal ions.
The aseptic plastic packaging container according to the item. 4. The utility model registration claim in which the antibacterial zeolite has a part or all of the ion-exchangeable ions in the zeolite replaced with ammonium ions and antibacterial metal ions. Aseptic packaging made of plastic. 5. The utility model registration claim 3 or 4 in which the antibacterial metal ion is an ion of silver, copper or zinc.
The aseptic plastic packaging container according to the item. 6. The multi-layer sheet according to claim 1 is replaced with a foaming resin, an antibacterial zeolite, a foaming agent and a nucleating agent, which is the antibacterial agent based on the total weight of the foaming resin. Claims 2 to 5 from the utility model registration as a foam in the range of 0.1 to 5% by weight of zeolitic zeolite, 5 to 15% by weight of the foaming agent and 0.1 to 5% by weight of the nucleating agent. The aseptic plastic packaging container according to one item to be selected.