JPH09149760A - Tool for absorbing water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water-absorbing tool useful for retaining the freshness of a fresh food, etc., by folding over an approximately rectangular laminated sheet comprising a semipermeable film and a water-absorbing film produced from a polymer consisting mainly of ethylene oxide units so that the semipermeable film is placed on the inner sides, and subsequently joining the folded sheets to each other. SOLUTION: An approximately rectangular aminated sheet 5 produced by laminating a semipermeable film (e.g. polyvinyl alcohol film) to a water- absorbing film comprising e.g. a polymer copolymerized with butylene oxide, etc., and containing ethylene oxide units as main repeating units, and, if necessary, further to a water-impermeable film (e.g. polyethylene film) on the other side of the water-absorbing film is folded over so that the semipermeable film is placed on the inner surfaces. The sheets on the side adjacent to the folded side are joined to each other with a seal member 7 to obtain the objective water-absorbing tool 1 capable of being utilized for the dehydration, dryness, etc., of a fresh food to retain its freshness and improve its taste, and capable of being easily used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material capable of absorbing water, for example, dehydration of fresh food, drying,
The present invention relates to a water absorbing tool that can be used for maintaining freshness by improving humidity and improving taste.

[0002]

2. Description of the Related Art Conventionally, as a water absorbing sheet,
Paper, cloth, non-woven fabric, etc. have been used, but they have drawbacks such as low water absorption, weak water retention, and liberation of water due to external stimulation. In addition, there is a resin in which the superabsorbent resin is sandwiched between paper and nonwoven fabric. However, since the superabsorbent resin is powdery, it is difficult to uniformly support the nonwoven fabric or the like.

In order to solve these problems, the present applicant has previously used a water-absorbent film made of a polymer mainly composed of ethylene oxide as a water-absorbent material, and laminating it on a semipermeable membrane polyvinyl alcohol (PVA) film. The water-absorbent sheet and the water-absorbent bag formed by bag-making the sheet with the PVA film as the inner surface were proposed. This water absorption bag
It is used with food etc. inside, and has the advantage that food is kept hygienic because the whole is bag-shaped.

However, the bag-like shape has a problem that it is difficult to put food such as fish through the opening, and the fish of various sizes may be broken when put in the bag.

[0005]

SUMMARY OF THE INVENTION The present invention has been made based on such a background, and provides a water absorbing tool which can be used for foods of various sizes and which can be easily taken in and out. That is, the gist thereof is that a semi-permeable film and a substantially rectangular laminated sheet of a water-absorbent film made of a polymer having ethylene oxide as a main repeating unit are laminated with the semi-permeable film as an inner surface. It is a water-absorbing tool which is made up of two sheets and is joined together, and the upper and lower sheets are joined together on the two adjacent sides.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. FIG. 1 is a perspective view showing one embodiment of the present invention, and FIG.
Is a perspective view showing another embodiment, FIG. 3 is a perspective view showing still another embodiment, and FIG. 4 is a cross-sectional view showing an example of the layer structure of the laminated sheet. Membranous film,
3 is a water-absorbent film made of a polymer having ethylene oxide as a main repeating unit, 4 is a non-water-permeable film,
Reference numeral 5 is a laminated sheet of layers 2, 3 and 4, and 7 is a seal portion.

The water absorbing tool of the present invention is a semipermeable film 2
And a water-absorbent film 3 made of a polymer having ethylene oxide as a main repeating unit, and a sheet 5 in which a non-water-permeable film 4 is laminated if desired. The semi-permeable film 2 is used on the side that comes into contact with food when used.
That is, it comes to the inner surface side of the water absorbing tool 1 of the present invention, has a strong affinity for water but is insoluble in water, and allows water molecules and odor components to pass through, but does not allow umami components having a large molecule to pass through. Has membrane permeability.

The water-absorbent film 3 is composed of a polymer containing ethylene oxide as a main repeating unit. A polymer consisting only of ethylene oxide is a water-soluble material that absorbs water and dissolves, but it is water-absorbing and insoluble in water by irradiation crosslinking or chemical crosslinking. It is also possible to make water-insoluble by copolymerizing ethylene oxide with a hydrophobic group such as butylene oxide or a longer-chain alkyl oxide. And all show high water absorption and good water retention. Further, it is preferable that the non-water-permeable film 4 is laminated on the outer surface of the water-absorbent film 3.

In the example shown in FIG. 1, the substantially rectangular laminated sheet 5 is half-folded with the semipermeable film 2 inside.
One side adjacent to the fold side 6 is joined by a seal portion 7. Further, in the example shown in FIG. 2, two substantially rectangular laminated sheets 5 are superposed with the semipermeable film 2 inside, and the adjacent two sides are joined by the seal portion 7 in an L-shape. is there.

As described above, since the water absorbing tool of the present invention has a shape like a document sandwich in which two adjacent sides are closed and the remaining two adjacent sides are open, foods such as fish can be easily taken in and out. For example, even when processing a large amount of food for business use, the processing can be efficiently performed.

Further, since the two adjacent sides are fused together, it is possible to put the fish or the like and press it firmly or press it to bring it into close contact with the surface of the food. Water absorption becomes easier than laying on the floor.

Further, in the example shown in FIG. 3, the end portion of the open side is continuously heat-sealed with a predetermined width to seal the seal portion 8.
Is formed. The seal portion 8 is provided on the water absorbent film 3
Even if water is absorbed from the end surface of the laminated sheet, the moisture is suppressed by the seal portion 8 and the layers of the laminated sheet 5 can be prevented from peeling off.

As the semipermeable film 2 in the present invention, PVA film, regenerated cellulose film (cellophane) or the like can be used. As the PVA, not only a vinyl acetate homopolymer saponified but also a vinyl acetate copolymerizable monomer (for example, an ethylenically unsaturated carboxylic acid) and vinyl acetate saponified It may be a modified PVA, or may contain a plasticizer such as glycerin for imparting flexibility.

The water-absorbent film 3 in the present invention may be a homopolymer of ethylene oxide, but preferably a polymer obtained by the reaction of the following components (A) and (B) is used. be able to.

(A) A polymer obtained by addition-polymerizing an alkylene oxide containing ethylene oxide as a main component to an organic compound having two active hydrogen groups (B) Polycarboxylic acid, polycarboxylic anhydride, polycarboxylic Lower alkyl ester of acid or diisocyanate Examples of the organic compound having two active hydrogen groups include ethylene glycol, diethylene glycol and propylene glycol, and the alkylene oxide having ethylene oxide as a main component added thereto is ethylene oxide. Alone or with this, propylene oxide, butylene oxide, styrene oxide, α-
A mixture with an olefin epoxide and the like can be mentioned.

As the polycarboxylic acid, phthalic acid,
Isophthalic acid, terephthalic acid, sebacic acid, and their anhydrides or lower alkyl esters,
As the lower alkyl ester, a methyl ester,
Examples include dimethyl ester and diethyl ester.

Examples of diisocyanates include tolylene diisocyanate, diphenylmethane diisocyanate and hexamethylene diisocyanate. The molecular weight of this polymer is preferably 50,000 or more, and more preferably in the range of 50,000 to 300,000.

In the water absorbent tool 1 of the present invention, the water absorbent film 3 is formed by molding the above polymer into a film. As a method for producing a film, a hydrous extrusion method or an aqueous solution casting method can be adopted for an ethylene oxide homopolymer (water-soluble). Further, the polymer obtained by the reaction of the above components (A) and (B) can be easily formed into a film by hot melt molding such as a melt extrusion method or a calender method. When the alkylene oxide (A) is substantially composed of ethylene oxide, the resulting polymer is water-soluble, and becomes water-insoluble when the amount of the other alkylene oxide copolymerized is increased. When the water-soluble polymer is made insoluble in water, it can be crosslinked by irradiation with ionizing radiation or ultraviolet rays. As the ionizing radiation, an electron beam, γ ray, X ray or the like can be used. When the dose of ionizing radiation is less than 0.5 Mrad, the degree of crosslinking is small and the whole may not be completely insolubilized in water, and when it exceeds 20 Mrad, crosslinking proceeds excessively and the water absorption is extremely reduced. 0.5 in absorbed dose
The range of ˜20 Mrad is preferred. Further, as a cross-linking method, chemical cross-linking in which a cross-linking agent is mixed and heated can be used.

As the water-impermeable film 4, the same semipermeable film as the layer 2 or a film of polyethylene, polypropylene, ethylene-vinyl acetate copolymer resin or the like can be used, whereby it is absorbed from food. It is possible to prevent the moisture from seeping out to the outer surface, and improve the odor blocking property, the moisture resistance, the blocking prevention property between the sheets, and the like.

In the above-mentioned laminated sheet 5, the semipermeable membrane 2 and the water-absorbent film 3, and further the non-water-permeable film 4 may be partially fused and laminated. As a result, the flexibility of the entire laminated sheet is increased, curling at the time of absorbing water is prevented, and the water absorbing ability of the water absorbent film 3 can be sufficiently exhibited. That is, the water-absorbent film 3
Swells when it absorbs water, so if you attach the semipermeable membrane 2 etc. over the entire surface, the whole will easily curl,
In addition, as a result of suppressing the water absorption expansion of the water absorbent resin film,
The water absorption rate and water absorption amount may decrease.

As a method of partially fusing, there is a method of heat fusing in a dot shape, a linear shape, a grid shape, or the like. Here, it is appropriate that the fused area is about 5 to 50% of the whole, and this area is 5
If it is less than 50%, the lamination strength is insufficient, and if it exceeds 50%, the effect of curling prevention is insufficient and the meaning of partial fusion is reduced.

As a method for partially fusing the water-absorbent film 3 and the semipermeable membrane 2 etc., for example, engraving is performed on a nip roll for lamination or a press plate to give unevenness, and not the entire surface. Only appropriate portions can be partially fused.

To seal one side or two adjacent sides of the laminated sheet 5, it is convenient to use a general heat sealing method. However, when cellophane is used as the semi-permeable film 2, heat sealing is difficult, so that it can be bonded with an adhesive or the like.

In the various embodiments illustrated above, the thickness of each layer can be appropriately set according to the application, but as an example, when the semipermeable membrane 2 is thin, it lacks strength and rigidity and is easily wrinkled, resulting in processing. In view of these points, the range of 5 to 25 μm is preferable, since the water resistance deteriorates and the water permeability deteriorates if it is too thick. Further, the water-absorbent film 3 has a better water-absorbing performance as it is thicker, but on the other hand, it is not easy to use.
The range of 0 μm is preferable. Furthermore, when the non-water-permeable film 4 is used, it is preferable to make it as thin as possible, and in view of workability, it can be set in the range of about 10 to 50 μm.

The water-absorption tool of the present invention is useful for removing excess water and odor from fresh foods, absorbing drip produced when frozen foods are thawed, and is used not only in distribution and processing of foods, but also in cafeterias. Even for commercial use,
It is also suitable for domestic cooking.

[0026]

According to the present invention, it is possible to obtain a water-absorbing tool which has a sufficiently high water-absorbing property and which allows foods to be taken in and out easily.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a water absorbing tool of the present invention.

FIG. 2 is a perspective view showing another embodiment of the water absorbing tool of the present invention.

FIG. 3 is a perspective view showing still another embodiment of the water absorbing tool of the present invention.

FIG. 4 is a cross-sectional view showing an example of the layer structure of a laminated sheet.

[Explanation of symbols]

 1 Water-absorption tool 2 Semi-permeable film 3 Water-absorbent film 4 Non-water-permeable film 5 Laminated film 7 Seal part 8 Seal part

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location A23B 4/04 501E

Claims (3)

[Claims] 1. A substantially rectangular laminated sheet of a semipermeable membrane and a water-absorbent film made of a polymer having ethylene oxide as a main repeating unit is laminated with the semipermeable membrane as an inner surface. , A water absorbing tool in which upper and lower sheets are joined together on two adjacent sides thereof. 2. The water absorbing tool according to claim 1, wherein the semipermeable membrane and the water absorbing film made of a polymer having ethylene oxide as a main repeating unit are partially fused. 3. The water absorbing tool according to claim 1, wherein a non-water permeable film is laminated on the other surface of the water absorbing film.