JPH0653408B2 - Packing material for cold insulation - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cold and warm packaging material used as a cold and warm packaging material for foods, a cold and warm compress as a medical aid, and the like. Relates to a cold and heat retaining packaging material using a water absorbing resin.

[Prior Art] Conventionally, a plastic film regenerator material in which a jelly-like substance that freezes in a freezer is sealed has been widely used as a packaging material for keeping food cold and warm. As a specific example, Icenon (registered trademark) or the like is used. Are known. Particularly in recent years, fresh foods and the like have come to be transported by so-called courier service, and the cold storage material made of the plastic film described above is being used instead of dry ice or ice.

[Problems to be Solved by the Invention] This plastic film cold storage material itself has a long-term cold insulation function, but it has a large volume and weight in an unused state and cannot be bent and used. .
For this reason, not only is the storage location limited in the freezer, the space cannot be used effectively, but it is also difficult to obtain a uniform cooling effect in the heat insulating container.
In addition, due to the above reasons, there is a drawback that the transportation and storage costs are also increased.

In addition, since the inside is filled with a jelly-like substance, it takes time and labor to manufacture and the cost is high. Therefore, it is difficult to make a desired shape each time according to the usage form, because of labor and cost, and there is an inconvenience that only a predetermined size can be used.

On the other hand, in the food and beverage industry, there is a demand for keeping table dishes such as sashimi at low temperature. For example,
Place the food on a cold packaging material shaped like a circular dish,
This is the case where the food is provided as it is or when the food is provided in a state in which it is wrapped in a cold insulating packaging material. In such a case, it is desirable that it has high decorativeness and can be easily used. This is also the case with the courier service described above, using a cold-packing material that has been preformed according to the internal shape of the packaging cardboard box, foamable polymer molding box, etc. Transporting is desirable in order to exert the cold insulation function. In addition, it is more desirable that it can be disposed of as it is after use for hygiene. These things are also considered when the cold insulating packaging material is used as a cold compress as a medical aid.

On the other hand, an application of the heat insulating packaging material is blood transportation, and in this case, it is optimal to keep the temperature at a temperature close to the normal temperature of human beings. Even in this case, it is desirable that it can be used promptly without using a special device.

In addition, even in foods that are preferably provided in a warmed state such as Shoumai, it is desirable that the heat insulating packaging material be hygienic and easy to use.

The present invention has been made in view of the above circumstances. That is,
INDUSTRIAL APPLICABILITY The present invention has a capacity, a small weight in an unused state, can be bent, and has a simple structure and can be easily manufactured into an arbitrary shape.
It is an object of the present invention to provide a low cost cold and heat insulating packaging material that is hygienic, easy to handle, and disposable.

[Means for Solving Problems] A means for solving the above problems will be described with reference to FIG. 1 corresponding to an embodiment. Two thin sheets of paper are placed in a wrap sheet 11 which is a bag-like member in which the peripheral portion of the impermeable sheet 3 is fixed.
As the water-absorbent resin, for example, water-absorbent resin powder in the intermediate layer of 1a and 1c
1b and the like are evenly dispersed, and an embossed water-absorbent resin sheet 1 is sealed, and the water-impermeable sheet 3 is a polymer laminated sheet.

[Operation] In the structure in which the water-absorbent resin sheet 1 is sealed in the wrap sheet 11 formed of the water-permeable sheet 2 and the water-impermeable sheet 3, when water is permeated through the water-permeable sheet 2, It absorbs water several hundred times its own weight and expands. If it is left in a freezer to be frozen, it can be used as a packaging material for keeping cold, and if it is heated in hot water or a steamer, it can be used as a packaging material for keeping warm.

During freezing, the impermeable sheet side of the cold insulation of the present invention is brought into contact with the inner wall of the freezer, and when a plurality of the present invention is stacked and frozen by bringing the impermeable sheet side and the impermeable sheet side into contact, Due to the action of the water-permeable sheet, it is possible to prevent the inner wall of the freezer and the cold and heat insulating packaging materials from sticking to each other due to ice.

Further, the water absorbing resin contains a large amount of water as compared with its own weight. In the present invention, since a large amount of water is used after being frozen or heated, even a small amount of water-absorbing resin can provide sufficient cooling and heat retaining effects as a cold and heat retaining packaging material.

[Examples] The present invention will be described in detail below based on the examples shown in the drawings.

FIG. 1 (a) is a sectional view showing the basic constitution of the present invention.
FIG. 1 (b) is a partially enlarged view thereof. In this figure,
Reference numeral 1 denotes a water-absorbent resin sheet described later, and this resin sheet is sealed in a wrap sheet 11 composed of a water-permeable sheet 2 and a water-impermeable sheet 3. This state is shown in the partially cutaway perspective view of FIG.

Here, the water-absorbent resin sheet is configured as follows. First, as the thin paper 1a, water-absorbent resin powder 1b is sprinkled on a paper or a non-woven fabric having a high water-absorbing property such as newsprint, non-sized medium-quality paper or non-sized high-quality paper, and uniformly dispersed. Then, a thin paper 1c of the same type is overlaid, and embossing is performed with a heating embossing roll to obtain the water absorbent resin sheet 1. The amount of the water-absorbent resin to be sprayed is preferably 10 to 150 g / m ² from the relationship with the water absorption amount. The thin paper preferably has a basis weight of about 10 to 60 g / m ² , and as a result, the resulting water-absorbent resin sheet has a sheet-like composition of 30 to 270 g / m ² .

As the water absorbent resin, modified polyvinyl alcohol resin, starch-acrylonitrile graft polymer hydrolyzate (manufactured by Sanyo Kasei Co., Ltd., Sunwet IM-300 (trade name)
Etc.), cross-linked polyacrylic acid salt (manufactured by Steel Chemical Co., Ltd., Aquakeep 4SH (trade name), etc.) and the like are used.

Thus, filling the water-absorbent resin in a sandwich shape between two thin papers has the following advantages as compared with the case where the water-absorbent resin is simply packaged.

(1) When the bag is immersed in water, absorption of water proceeds rapidly and uniformly, and the water-absorbent resin powder particles are not solidified into a so-called step state.

(2) If it is made into a sheet shape, accurate weighing operation can be easily performed only by cutting into a desired size.

(3) It is necessary to adjust the resin gel swollen after being soaked in water to be evenly distributed in the bag if it is a powder alone, but to obtain a resin gel that is evenly distributed as it is if it is a sheet shape. You can

As the water permeable sheet, any sheet having water permeability and water resistance may be used. For example, synthetic woven paper, non-woven fabric, or those obtained by subjecting these to resin processing to improve water resistance is used. Further, as will be described later, if the water-permeable sheet can be heat-sealed, it is more preferable in the present invention.

As the water-impermeable sheet, there can be used a film or sheet having cold resistance and excellent releasability, such as paper or a silicone resin processed sheet obtained by coating a general-purpose synthetic resin film with silicone resin on one side. In this case, the silicone resin surface is formed so as to be the back surface of the cold insulating packaging material. Further, a film having an extremely low water absorption rate such as a polypropylene film or a polyester film, and a film having an extremely low moisture permeability such as a polyethylene or vinylidene chloride film can be used. In particular, a laminated film having the above-mentioned low water absorption rate and low moisture permeability is excellent, and a laminated sheet of stretched polypropylene and non-stretched polypropylene is often used in terms of price.

The water-permeable sheet 2 and the water-impermeable sheet 3 are fixed at their peripheral portions to form a fixed portion 4 and have a bag shape. The fixing method is performed by a method such as bonding, sewing or heat welding. Be done. In particular, heat welding, so-called heat sealing, is preferable from the viewpoint of easy processing.

When the present invention having such a structure is used as a cold insulating packaging material, the present invention is first immersed in water. At this time, the water-absorbent resin absorbs tens to hundreds of times its own weight of water and expands in a jelly form. Then remove from water and remove excess water with a dry towel.

In order to freeze this, the water-impermeable sheet 3 side is brought into contact with the inner wall of the freezer, and a plurality of the water-permeable sheets 2 of the present invention are used.
Side and the impermeable sheet 3 side are brought into contact with each other and stacked and frozen. Due to the excellent peeling action of the silicone resin, the excellent low moisture permeability of the laminated film, and the low absorptivity of the present invention, the present invention can be prevented from sticking to the inner wall of the freezer with ice or sticking to each other of the present invention. As a result, a large amount of cold and heat insulating packaging material can be frozen easily and in a small space. In particular, the shape of this example is suitable as a cold-packing material for fresh food stored in a rectangular container such as a cardboard box.

On the other hand, when the present invention is used as a heat insulating packaging material, the present invention is used by directly immersing the present invention in hot water or by immersing it in water and then heating it with a steamer or the like.

FIG. 3 is a diagram showing another shape example of the present invention. In this example, the water-permeable sheet 2 and the water-impermeable sheet 3 are heat-sealed so that a plurality of strip-shaped bags are laid continuously in a row, and the water-absorbent resin sheet 1 is sealed therein. In this example, after absorbing water, it is frozen, and it can be wound around a cylindrical object such as ham or fish and used as a packaging material for cold storage.

Further, this example can also be used for cold compresses such as arms and legs.

In addition, in this example, a perforation can be provided between the adjacent water-absorbent resin sheets 1 to divide them into arbitrary sizes for use.

FIG. 4 shows another example of the shape of the present invention. In this example, the water-permeable sheet 2 and the water-impermeable sheet 3 are cut into a fan shape, and the fan-shaped water-absorbent resin sheet 1 is similarly sealed by heat sealing. Further, FIG. 5 shows an example of a circular shape.

Each of the cold-insulating packaging materials shown in FIGS. 4 and 5 imitates the shape of tableware, and fresh food such as sashimi and fruits are placed on top of this and provided to customers as is, and these are also served between meals. It will be possible to keep the food of the cold. In addition, it is optional to re-freeze and use after thawing.

Example 1 46 g / m ² newsprint paper Water-absorbent resin sandwiched with 50 g / m ² of water-absorbent resin (Aquakeep 4SH, manufactured by Iron and Steel Chemical Co., Ltd.) in the middle layer of two sheets and embossed in a lattice pattern with the powder. The sheet was cut into a length of 20 cm and a width of 10 cm. This piece of sheet paper will contain 1 g of water-absorbent resin. Thermal adhesive paper (Nippon Shigyo Co., Ltd. heat pack MC (trade name), basis weight 30 g /
m ² ), a wrap sheet having a length of 22 cm and a width of 12 cm was prepared. The water-absorbent resin sheet was encapsulated with a heat-seal width of 1 cm and sealed by heat-sealing.

On the other hand, about 0.7 g / m ² of silicone resin (Shin-Etsu KS838) was coated on one side of a high-quality paper to make a water-impermeable sheet, and the non-coated surface was attached to the wrap sheet to obtain a cold-insulating packaging material. .

Next, this cold insulating packaging material was immersed in tap water for 1 minute to wipe off excess water. This gives a total weight of 236 g and a thickness of
It became 15 mm. Several of the cold insulating packaging materials were stacked in a freezer at -20 ° C and left for 24 hours, but they could be easily taken out without sticking to each other. It should be noted that, as a comparative example, it was frozen at the same time without using the silicone resin processed sheet, but even if the front and back surfaces were sufficiently wiped off in water, it was difficult to firmly bond them to the wall surfaces of the freezer or to each other and peel them off. It was

Next, the frozen present invention is placed on a plate of the same shape,
A thermometer was inserted between the cold insulating packaging material and the dish to observe the temperature change. The results are shown in Table 1 below. The room temperature is 25 ° C.
Met.

As is clear from Table 1, a small amount of the water-absorbent resin sheet provided a cold-retaining effect for a long time.

Example 2 A heat insulating packaging material was produced in exactly the same manner as in Example 1 except that the dimensions of the water absorbent resin sheet were 16 cm in length × 11 cm in width and the dimensions of the wrap sheet were 20 cm in length × 20 cm in width.

Next, soak this heat-retaining packaging material in boiling water at 100 ° C for approximately 1000
Absorbed ml of boiling water. This resulted in a thickness of 15 mm. The temperature of the heat insulating packaging material at this time was 80 ° C. This heat insulating packaging material is placed in a styrofoam sealed container measuring 40 cm in length × 33 cm in width × 28 cm in depth, and 15 pieces of shoe mai are lined up on the heat insulating packaging material and the lid is closed to change the temperature in the sealed state. I observed. The results are shown in Table 2 below. The room temperature is 18 ℃
Met.

As is clear from Table 2, even after 60 minutes, 50 ° C
The temperature can be maintained, and a practically sufficient heat retention effect was obtained.

[Effects of the Invention] The packaging material for keeping cold and warm according to the present invention has the following unique effects.

(1) It is small and lightweight when not in use, so it is easy to handle, easy to handle for transportation and storage, and the space in the freezer can be used efficiently. Further, since it can be bent and used, a uniform cold-retaining effect can be obtained by bending or wrapping the heat-insulating container or the object at an arbitrary position according to the shape of the object.

(2) The work efficiency is good because the water absorption time is short and the time required for freezing is extremely short. In particular, even when they are piled up in a freezer and frozen, the inner wall of the freezer and the cold insulating packaging materials do not stick together due to the action of the polymer laminated sheet.

(3) Since the water-absorbent resin is evenly dispersed in the intermediate layer of the cold insulating packaging material, a sufficient cooling effect can be obtained and the cooling time can be kept long.

(4) Since the structure is simple, it can be easily formed into an arbitrary shape according to the usage form, and it is low cost and disposable. Moreover, since it is odorless, it is hygienic.

(5) It can be used not only as a cold insulating packaging material but also as a heat insulating packaging material, and even in this case, the same effect as described above can be obtained.

[Brief description of drawings]

FIG. 1 (a) is a configuration diagram showing the basic configuration of the present invention, FIG.
(b) is a partial sectional view thereof, FIG. 2 is a partially cutaway perspective view of the present invention, and FIGS. 3 to 5 are views showing other examples of the shape of the present invention. 1 ... Water-absorbent resin sheet, 1a, 1c ... Thin paper, 1b ... Water-absorbent resin powder, 2 ... Water-permeable sheet, 3 ... Water-impermeable sheet, 4 ... Fixed part.

Claims (3)

[Claims] 1. A sandwich structure in which a water-absorbent resin is evenly dispersed between two thin paper sheets in a bag-shaped material in which the peripheral portions of a water-permeable sheet and a water-impermeable sheet are fixed, and an embossing is performed from the surface. A cold and heat-retaining packaging material, which is obtained by sealing a water-absorbent resin sheet that has been subjected to. 2. The water-absorbent resin sheet comprises two thin papers having a weight per unit area of 10 to 60 g / m ² , and the amount of the water-absorbent resin dispersed between the two thin papers is 10 to 150 g / m ^2. The packaging material for cold and heat insulation according to claim 1, wherein the packaging material is m ² . 3. The packaging material for cold and warm insulation according to claim 1 or 2, wherein the impermeable sheet is a laminated sheet having an outer surface coated with a silicone resin.