JP2742444B2 - Cryopreservation bag - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for preserving frozen preservation, which is required to be dehydrated or dried, for example, when a cryopreservation net or the like is used for cryopreservation. The present invention relates to a frozen storage bag which does not require freezing pretreatment, and maintains good quality during and after storage.

[Related Art] A case where the above-described technology is applied to frozen storage of a laver seedling net will be described as a representative example.

After the laver is cultivated by artificial seeds, the laver germinates densely from the beginning, so that the laver can be collected from an early stage. However, the plant becomes densely planted, and the disease is likely to occur in autumn. In order to prevent the occurrence of the disease and to increase the production in the spring, seedling networks have conventionally been stored at low temperatures in production areas.

This is a method in which seed nets that have grown to some extent are frozen and stored at a temperature of -20 to -30 ° C, and brought out to the sea when there is room in the fishing grounds, where they are raised and collected after landing as pretreatment for freezing. Centrifuged the seedling net for several minutes to reduce attached moisture to 10-
This is a method of removing 20 wt%, further drying in the sun or in the shade for 1 to 3 days, packaging this in newsprint or the like, and storing it frozen. This method has been widely practiced nationwide since around 1965, and has been established as an indispensable technique for laver culture.

[Problems to be solved by the invention]

However, in the above method, the work is affected by the weather, so that the work efficiency is poor, and the water content of the seed and seedling net cannot be always the same. In particular, in a state where water is not sufficiently removed, diatoms attached to the seed and seedling network propagate and hinder the growth of glue or mix with glue to lower the quality of the product. Furthermore, if diatoms grow excessively, so-called "spot rot" occurs, causing catastrophic damage.

The present inventors have conducted intensive studies to solve the above-described problems, and as a result, by always properly performing the water removal in the freezing pretreatment, the diatoms are killed, and at the same time, the attached water freezes due to the growth of ice crystals. We thought that destruction of the organization would be prevented.

The present invention has been made based on the above idea, and has as its object to provide a cryopreservation bag that holds a centrifugally dehydrated seedling net at a predetermined moisture.

[Means for solving the problem]

In order to achieve the above object, the frozen storage bag of the present invention forms a moisture absorption layer by sandwiching a polymer water-absorbing agent between two sheet-like water-permeable substances impregnated with a humectant. Then, a sheet is formed by arranging a water-impermeable film on one surface of the moisture-absorbing layer and a water-permeable film on the other surface to form a sheet with the water-impermeable film on the outside. .

[Action]

Since the cryopreservation bag of the present invention has the above-described configuration, if a seedling net from which moisture has been removed by centrifugation is placed in this bag, attached moisture that could not be removed by centrifugation is absorbed by the polymer. While being removed by the agent, the humidity conditioner maintains the atmospheric humidity at a relative humidity of 50-85% suitable for storage.

〔Example〕

Examples of the polymer water-absorbing agent used in the bag for frozen storage of the present invention include polymerizable monomers that become water-soluble or water-soluble by hydrolysis in polysaccharides such as starch and cellulose, such as (meth) acrylic acid and (meth) acrylic acid. ) Acrylates,
(Meth) acrylic amide, (meth) acrylonitrile, maleic acid, etc., or their oligomers or co-oligomers are graft-polymerized and, if necessary, hydrolyzed to obtain a three-dimensional hydrophilic polymer. And those obtained by three-dimensionally polymerizing a hydrophilic polymer such as polyethylene oxide, polypropylene oxide, polyvinylpyrrolidone, sulfonated polyethylene and poly (meth) acrylate with a crosslinking agent.

Commercially available products include Preaple PX-402A (manufactured by Showa Denko KK), Sunwet IM-300 (manufactured by Sanyo Kasei Kogyo Co., Ltd.), and AquaKeep 10SH (manufactured by Steel Chemical Co., Ltd.)
Etc.

Examples of the crosslinking agent include di- or tri (meth) acrylates of polyols such as ethylene glycol,
Examples include unsaturated polyesters, allylated starch, and allylated cellulose obtained by reacting polyols with unsaturated acids such as maleic acid.

The humectant may be any liquid that is itself liquid or water-soluble at normal temperature and has a humidity control function of absorbing moisture in a gaseous substance, such as ethylene glycol, propylene glycol, diethylene glycol, and monoethyl. Ethers, polyhydric alcohols such as 1,3-butylene glycol and glycerin, low-polymerized polyhydric alcohols such as polypropylene glycol, polyethylene glycol and polyglycerin, sugar alcohols such as xylitol, sorbitol and maltitol, and methylcellulose and carboxymethylcellulose An aqueous solution of a hygroscopic polymer substance such as glycerin or glycerin, which can be in contact with food, is preferred.

The sheet-like water-permeable substance sandwiching the polymer water-absorbing agent may be any material that impregnates and supports a water-permeable, liquid conditioning agent, and examples thereof include paper, pulp, and nonwoven fabric.

On both sides of the sheet forming the bag of the present invention, the water-permeable film and the water-impermeable film are respectively disposed, but the water-permeable film disposed on one side is made of a thermoplastic material. Fine-grained nonwoven fabric, thermoplastic film once made water-impermeable, with communication holes provided by electron irradiation, etc., or foamed thermoplastic film so that fine communication holes are formed during film production After the addition of an inorganic substance, a high melting point nucleating agent, and stretching, fine holes are formed, and those having frost resistance can be appropriately used.

However, since the water-permeable film is in direct contact with an object to be humidified, such as glue, the sheet-like water-permeable substance, such as paper or pulp, carries moisture and is easily applied when pressure is applied from the outside. And non-woven fabrics having poor heat-sealing properties with the water-impermeable film disposed on the other surface cannot be used. Usually, a polyolefin-based nonwoven fabric such as polypropylene is preferably used.

As the water-impermeable film, any of those which can be heat-sealed with the above-mentioned water-permeable film having freezing resistance can be used. However, a polyolefin film such as a polyethylene film is preferable because it is inexpensive and easily available.

In order to make a frozen storage bag using the above-mentioned materials, first, as shown in FIG. 1, a polymer water-absorbing agent 1 is sandwiched between two sheets of a sheet-like water-permeable substance 2 such as paper. A water absorbing material 4 is formed by impregnating and supporting a liquid humectant 3 such as glycerin on the water permeable material 2.

As shown in FIG. 2, a water-permeable film 5 and a water-impermeable film 6 made of a nonwoven fabric made of a thermoplastic resin are arranged on both surfaces of the moisture-absorbing layer 4, respectively.
The bag sheet 7 is formed by heat sealing the periphery. The bag sheet 7 is heat-sealed at its periphery, and the periphery of the moisture absorbing layer 4 is locked when the films 5 and 6 are heat-sealed. The surface is free.

The bag is formed by setting the water-impermeable film of the bag sheet 7 outside, and a bag for frozen storage (hereinafter referred to as a bag) 8 of the present invention shown in FIG. 3 is obtained.

In order to store the seedling net in the bag 8, the seedling net 9 shown in FIG.
As shown in FIG. 5, a water-permeable film 5 is disposed on both sides of the moisture-absorbing layer 4 shown in FIG. 5, and the periphery is heat-sealed through a double-sided water-absorbing sheet (hereinafter referred to as a partition sheet) 10. Stored in multiple stages.

The seedling net 9 stored in the bag 8 is put in a freezer, but the attached water is absorbed and removed by the polymer water absorbing agent 1 until completely frozen, and the atmospheric humidity is 50% or less. If the conditions become unsuitable, the humidity regulator 3 releases moisture, and the seedling net is maintained at a suitable atmospheric humidity.

Although the above-described bag has been described as an example in which the bag is used for a litter seedling net, it can always be used effectively when a similar atmospheric humidity is required.

Example 1 Two sheets of water-absorbing paper of 60 cm × 200 cm were sandwiched with 50 g of a polymer water-absorbing agent comprising a crosslinked sodium polyacrylate,
A water absorption layer in which 72 g of glycerin was carried on the paper was formed. A bag sheet was formed by arranging a polypropylene nonwoven fabric and a polyethylene film on both surfaces of the moisture absorbing layer, respectively. With the water-impermeable film of the packaging sheet facing outside, a bag of 60 cm x 100 cm was folded.
Separate sheets of 30 cm × 60 cm in which both surfaces of the moisture absorbing layer having the same composition as described above were sandwiched between polypropylene nonwoven fabrics were produced.

After putting the seedling net (1 kg / 1 sack) after centrifugation into this bag with 2 sac (total 2 kg) interposed with a partition sheet between them, good workability and good adhesion were obtained. A package is obtained.

Example 2, Comparative Example 1 Seedling net packed in the same manner as in Example 1
After two days, two sac (2 kg) of the seaweed seedling nets each wrapped in a newspaper of 60 cm × 200 cm were frozen and stored at −30 ° C. for 4 months, and their quality immediately after unpacking was evaluated. The results are shown in Table 1.

Example 3 and Comparative Example 2 Seed and seedling nets packed and stored in the same manner as in Example 2 and Comparative Example 1 were placed in the sea and grown for 10 days. Quality evaluation was performed when these were harvested and made into sheet glue. The results are shown in Table 2.

Example 4, Comparative Example 3 5 kg of milled rice was put into each of the bag prepared in Example 1 and a conventional polyethylene bag, and stored at -5 ° C for 6 months. Table 3 shows the quality evaluation results after opening.

[Effects of the Invention] As described above, the cryopreservation bag according to the present invention is efficient without being affected by the weather, and without damaging the tissue of the preserved product due to the growth of ice crystals and the like even during the cryopreservation. Long-term preservation is possible, and since the yield is increased, the economy is high, and it greatly contributes to the producer.

[Brief description of the drawings]

1 to 3 are explanatory views of a bag for frozen storage of the present invention. FIG. 1 is a longitudinal sectional view of a moisture absorbing layer, FIG. 2 is a longitudinal sectional view of a bag sheet, FIG. Is a perspective view of a bag for frozen storage prepared by a bag sheet, and FIG. 4 shows the bag of FIG.
FIG. 3 is a sectional view taken along line IV-IV in FIG. 3 showing a state where the seedling net is stored with a partition sheet interposed therebetween, and FIG. 5 is a longitudinal sectional view of the partition sheet. 1 ... Polymer water-absorbing agent, 2 ... Sheet-like water-permeable substance, 3 ...
... Temperature, 4 ... Moisture-absorbing layer, 5 ... Water-permeable film,
6 ... impermeable film, 7 ... bag sheet, 8 ... frozen storage bag (bag), 9 ... seedling net, 10 ... double-sided water-absorbing sheet (partition sheet).

Claims (1)

(57) [Claims] 1. A water-absorbing layer is formed by sandwiching a high-molecular-weight water-absorbing agent between two sheet-like water-permeable substances impregnated with a humidity control agent. A bag for frozen storage, wherein a sheet is formed by arranging a water-permeable film and a water-permeable film on the other surface, and the water-impermeable film of the sheet is placed outside the bag.