JPS5925873A - Preparation of gel for cold insulation - Google Patents

Abstract

PURPOSE:To obtain a gel for cold insulation, having rich elasticity and flexibility and improved mechanical strength, and not easily frozen, by cooling an aqueous solution containing a specific polyvinyl alcohol (PVA), a water-soluble polyhydric alcohol and highly viscous water-soluble high polymer in specific concentrations, solidifying the cold aqueous solution, and dehydrating the solidified product. CONSTITUTION:(A) 1.5-8wt% polyvinyl alcohol (PVA) having >=95mol% saponification degree and >=1,500 viscosity-average polymerization degree is incorporated with (B) 10-85wt% 2-6C water-soluble polyhydric alcohol having 2-6 hydroxyl groups in the molecule thereof, suitably 1,2-propylene glycol, and (C) 0.2-15wt% highly viscous water-soluble high polymer other than the PVA, suitably i-carrageenan, having >=300cP (25 deg.C) viscosity of a 2wt% aqueous solution are mixed, and the resultant aqueous solution is then cooled and solidified at <-6 deg.C. The resultant solid is then subjected to the vacuum dehydration at 5-95wt% dehydration ratio to give the aimed gel for the cold insulation. USE:A gel for cold insulation to prevent the depilation by side effects of a carcinostatic agent.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a cold-retaining gel, and particularly provides a method for producing a cold-retaining gel made from polyvinyl alcohol and having excellent properties not seen in conventional cold-retaining gels.

Various cooling gels have already been proposed under the names of cooling gel, cold preservation gel, cold heat transfer medium, colloidal refrigerant, cold preservation device, cold preservation composition, and ice pillow that does not require ice. It is put into practical use. However, the following (1) to (
As summarized in 9), all of them have problems in product properties or manufacturing methods.

(1) The production of agar gel is well-known as an easy method for producing a hydrogel for cold storage. That is, 0.1 wt% or more, for example 1 to 10 wt%, to hot water or boiling water at 80 to 94 ° C.
% of agar is dissolved and then allowed to cool to room temperature.
Water-containing gel (hydrogel) with a water content of about 90 to 99 wt%
can be easily obtained. However, when this gel is cooled in the ice compartment of a refrigerator and then used as a cold storage gel, such as an ice pillow or an ice bag substitute, the agar gel has poor elasticity and is extremely brittle, so it may cause a foreign body sensation to the human body. Moreover, the gel disintegrates during use, which is far from providing a comfortable feeling.

In addition, it often freezes and hardens in the ice compartment of a refrigerator, making it inconvenient to use as a substitute for ice pillows or ice bags. In this case, the freezing temperature can be lowered by immersing the agar in an antifreeze solution such as ethylene glycone propylene glycol, or by cooling a heated aqueous solution containing both agar and antifreeze solution. The resulting gel is also brittle and easily disintegrates, making it unsuitable for use in pillows and other cold storage gels.

(2) Similar to agar, monocarrageenan, which contains a D-galactose type structure, a 3°6-anhydrogalactose type structure, a polygalactose partial sulfate type structure, etc., can easily form into a hydrogel (water content 90
~97wt%), but like agar, it has the disadvantage of being brittle and is also extremely soft. It has long been often emphasized that soaking this gel in an aqueous solution of potassium chloride or chloride can increase its mechanical strength, but even after such post-treatment, the fact remains that it is as brittle as agar. .

Although it is well known that carrageenan and locust bean gum are used in combination to increase the elasticity of the gel, it is not very effective.

Furthermore, the fact that it freezes and hardens in the refrigerator ice chamber and the problems after countermeasures with antifreeze such as ethylene glycol are the same as in the case of agar.

(3) From an aqueous solution of D-mannuronic acid (MPa) containing an L-chururonic acid type structure, it is added to an acidic aqueous solution (pH 2.5-5), or to calcium, norium salt. By dropping (or immersing) into an aqueous solution containing water-soluble salts such as zinc, copper, iron, aluminum, and nickel, a hydrogel with a water content of 97 to 98 wt% can be obtained, but as is well known, this gel is also fragile. , it is brittle and, like agar, freezes and hardens.

(4) Gelatin gel is also known, but the gelatin concentration is 2~
At 15 wt%, it only exhibits a soft jelly-like appearance, and although a strong gel can be obtained by increasing the gelatin concentration to 15 wt% or more, especially 3 wt% or more, it is a rigid body that lacks flexibility and has a low water content. Not only is it low in quality, but it also has the disadvantage of emitting a smelt odor.

(5) Konjac containing a D-mannose type structure (!: D-glucose type structure) is one of the many natural product gels (gelatin, tofu, starch paste, agar, alginic acid, curdlan, carrageenan, farcellan, pectin). However, it is a high water content gel that does not easily lose its shape, has flexibility and elasticity, and has a water content of 97wt.However, when used repeatedly as a cold storage gel, the gel disintegrates rapidly. In other words, konnyaku is relatively stable as long as it is soaked in an alkaline cold water solution containing calcium ions, but if it is cooled (frozen) or
In the process of repeating melting and melting, the precipitation and uneven distribution of lime are promoted, and the gel becomes pasty.

[6) CMC (calcexymethyl cellulose nat IJ)
Iron, chromium, aluminum, lead, zeta-lium, and tin salts of rum cellulose glycolate have also been proposed, but they form soft pasty gels, and the gel structure often disintegrates (Special Publications Publication No. 1973). -1.121.0). Starch or CMC and borax (sodium tetraborate + hydrate)
The gel produced by the reaction with is also famous, but it is also weak.

Moreover, even if measures are taken against freezing and hardening, and by using antifreeze, the gel still tends to disintegrate.

(7) It has been known for a long time that when boric acid (or boric acid aqueous solution) or borax (or borax aqueous solution) is added to a polyvinyl alcohol aqueous solution, gelation occurs immediately. However, the resulting gel is fluid, soft, and easily shreds by simply pinching it with the fingertips. In addition, there is a problem of syneresis (separation of water contained) during repeated use (Japanese Patent Publication No. 1983-11-210).

Store polyvinyl alcohol/borax gel in the refrigerator (freezer)
By cooling in the ice chamber, the water in the gel freezes, and in order to prevent the gel from becoming hard, the bottle 14 is
A method has also been proposed in which monohydric alcohol, glucose, or sucrose is added to an aqueous solution of alcohol, and then gelled with borax. C% Kosho 46-19602. ).

Another method to lower the freezing point of polyvinyl alcohol/borax gel is to immerse the gel in an antifreeze solution such as ethylene glycol or propylene glycol; In addition to further weakening and losing its shape due to
Antifreeze solutions such as methanol, ethanol, and acetone also have the disadvantage that the gel collapses.

(8) Phenol, naphthol, Congo Rez I
Phenols or amine compounds such as S, or It'
Many polyvinyl alcohol gels (f) made of metal compounds such as tanium, chromium, and zirconium have also been proposed, but all of them have the same drawbacks as the polyvinyl alcohol/borax gel.

(9) Cross-linking agents such as aldehydes, dialdehydes, unsaturated nitriles, noisocyanates, trimethylolmelamine, shrimp chloride IS phosphorus, bis=(β~hydroxyethyl)sulfone, polyacrylic acid, 2methylolurea, maleic anhydride, or It is also well known to form an aqueous solution of polyvinyl alcohol using a copolymerized component, but in addition to requiring operations using chemical reagents, in order to obtain a gel that does not harden when placed in a refrigerator (freezer) or ice chamber, the gel must be mixed with an antifreeze solution such as ethylene glycol. In addition to having to be immersed in water for a long time,
It is difficult to obtain a gel that is highly elastic and flexible.

The present inventor has conducted studies to develop a method for inexpensively and stably producing a gel using polyvinyl alcohol, which is water-insoluble, has excellent mechanical properties, and is difficult to freeze in refrigerators (freezers) and ice chambers. By cooling, solidifying, and vacuum dehydrating (drying) an aqueous solution or suspended aqueous solution containing polyvinyl alcohol, water-soluble polyhydric alcohol, and highly viscous water-soluble polymer, it becomes highly elastic and flexible.
Furthermore, we obtained the knowledge that a solid gel that does not easily freeze can be obtained.
We have completed this invention which is particularly effective.

That is, the present invention comprises a polyvinyl alcohol having a saponification degree of 95 molar or more and a viscosity average degree of polymerization of 1,500 or more, a water-soluble polyhydric alcohol having 2 to 6 carbon atoms and having 2 to 6 hydroxyl groups in the molecule, and is different from polyvinyl alcohol,
A highly viscous water-soluble polymer with a 2% aqueous solution viscosity of 300 cP (25°C) or more, and the concentration of the polyvinyl alcohol, the water-soluble polyhydric alcohol, and the water-soluble polymer,
1.5-8wt%, 10-85wt% and 0.9wt%, respectively.
The aqueous solution adjusted to 2 to 15 wt is cooled and solidified to a temperature lower than -6°C, and then vacuum dehydrated to a dehydration rate (weight loss rate of the cooled and solidified material) of 5 wt% or more and 95 wt% or less. Provided is a method for producing a cold-retaining gel, which is characterized by subjecting the gel to cold storage gel.

According to the present invention, by gelling an aqueous solution or suspended aqueous solution containing polyvinyl alcohol, the water-soluble polyhydric alcohol, and the highly viscous water-soluble polymer, it has high elasticity and flexibility, and also freezes even in a freezer icebox. You will get a gel that does not.

Moreover, in the present invention, by using the above-mentioned highly viscous water-soluble polymer in combination, the degree of moisture imparted to the skin can be adjusted according to the preference of the user of the gel of the present invention. The present invention does not require acids, alkalis, radical sources, radiation, organic solvents, reaction reagents, etc. that are commonly used in the gelation of synthetic polymers in the gelation process and its pretreatment process;
No subsequent curing treatment or post-treatment to lower the freezing point (C temperature) is required. Moreover, the gel obtained by the present invention also has rubber-like elasticity, flexibility, and mechanical strength necessary for a soft type (non-freezing hardening) gel for cold storage.

Furthermore, the gel of the present invention is completely different from the above-mentioned cooling gel of an aqueous polyvinyl alcohol solution in that it is insoluble in water or hot water and exhibits no stickiness. In other words, the present invention provides a new gel that is completely different from the knowledge regarding the conventional gelling of an aqueous polyvinyl alcohol solution by cooling, or the gelling of an aqueous polyvinyl alcohol solution by chemical treatment. means.

Saponification degree of polyvinyl alcohol used in the present invention: 1d9
It requires a molar ratio of 5 or more, preferably 97 or more. Even if polyvinyl alcohol having a saponification degree of 80 to 88 mol %, particularly 85 mol % or less, is used, only a weak gel is obtained, and the object of the present invention is not achieved.

The degree of polymerization of polyvinyl alcohol used in the present invention is 1.5
Requires 00 or more. When the degree of polymerization is 300 to less than 1,500, especially 1,400 or less, the viscosity is 0. Or only a soft gel is formed. In the present invention, for example, the degree of polymerization is 1.5.
Polyvinyl alcohol of about 0.00 to 3,300 can be used, but one commercially available product with a high polymerization degree (polymerization degree of 1.
500~2', 600) is better to use.

In the present invention, first, a water-soluble i containing polyvinyl alcohol, a water-soluble polyhydric alcohol, and a water-soluble polymer different from polyvinyl alcohol is prepared.

The concentration of polyvinyl alcohol is 5 to 8 wt.
%, preferably 2 to 6 wt%.

If this concentration is increased above 10 wt%, the viscosity of the aqueous solution at room temperature will increase, and denaturation such as increased viscosity or partial solidification may occur during storage, making it difficult to handle and ensuring a soft texture. Since it is somewhat too strong, it is better to limit it to the above 8 wt%.

Moreover, if this concentration is too low, the mechanical strength of the gel produced will decrease. Therefore, this concentration is 1.5w
It is good to set it to t% or more, preferably 2wt% or more.

In the present invention, prior to forming a gel, a water-soluble polyhydric alcohol as an antifreeze agent (freezing point depressant) is dissolved in the polyvinyl alcohol aqueous solution. As the water-soluble polyhydric alcohol having 2 to 6 hydroxyl groups in the molecule used in the present invention, a polyhydric alcohol having about 2 to 6 carbon atoms is usually used. Examples of this antifreeze agent include ethylene glycol. The freezing point of pure ethylene glycol is -16°C, but the freezing point of an aqueous solution with a concentration of 38vO1% and 58vo1% (60wt%) is
-23°C and -49°C, respectively. Therefore, it is not necessarily necessary to coexist a particularly large amount of ethylene glycol, for example, 58 vol. 1%, in the aqueous polyvinyl alcohol solution;
By setting the 40VO to about 1%, the freezing point can be reduced by about -20
The object of the present invention can be achieved by lowering the temperature to .degree. This antifreeze effect is not limited to ethylene glycol.
1.2-propylene glycol (furopylene glycol) (40wt% substitution, -20°C), 1,3-propylene glycol (50wt% substitution, -24°C), glycerin (49wt% substitution, -21°C), 2-methyl-2,4
It is also found in water-soluble polyhydric alcohols such as -bentanediol (71 wt% substitution, -20°C), which lowers the curing temperature of the gel to below -20°C. -10 to -20°C), it usually does not harden and maintains elasticity, flexibility, and a feel similar to living tissue, which are suitable for uses such as ice pillows and head cooling gels for preventing hair loss due to side effects of anticancer drugs, which will be described later.

These polyhydric alcohols, in addition to the above-mentioned action as a freezing point depressant, also contribute to improving the mechanical strength of the cold-retaining gel obtained by the present invention. In other words, the coexistence of the above-mentioned polyhydric alcohol significantly improves the gel strength compared to the case where a simple polyvinyl alcohol aqueous solution is gelled. For example, even from an aqueous solution of 2.5 to 8 wt%, a cold preservation gel with excellent mechanical strength can be obtained by the coexistence of the polyhydric alcohol.

As mentioned above, as the water-soluble polyhydric alcohol having 2 to 6 hydroxyl groups in the molecule, polyhydric alcohols having about 2 to 6 carbon atoms are usually used, but in this case, in addition to the hydroxyl groups, , such as carboxyl group, acyl group, amine group, sulfhydryl group, imino group, carzenyl group, alkoxy group, cyano group, sulfinyl group, mesyl group (me
Water-soluble polyhydric alcohols having substituents such as a syl group), a sulfone group, a sulfonyl group, and a nitro group are also useful. Therefore, the water-soluble polyhydric alcohol of the present invention includes, for example, polyglycerin, 1,4-butanediol, 1,3-butanediol, and others, in addition to the aforementioned glycerin and 1,2-fuClpyrene glycol. Sugars (erythritol, arabinose, xylose, xylitol, glucose, cruditol (sorbitol, sorbitol), gluconic acid, glucuronic acid, curcaric acid, calacturonic acid, fructose, glucosamine) have already been added to food in Japan. Most preferred are 1,2-propylene glycol (propylene glycol), chrycerin, and D-sorbitol, which are allowed to be added in large amounts.

These are said to have no problems in animal test results regarding carcinogenicity, acute toxicity, subacute toxicity, chronic toxicity, etc. (NationaICancer In5t, U, S
,A.

``Carcinogenicity Data Survey Report'', I), 417, p.
147゜p, 265 (1975) Overseas Technical Data Research Institute,
Takeji Ishibashi, ``The whole picture of food additives'', I), 140~
144, p. 120-123 (1971) Nankodo, Morizo Ishidate, ``Food Additives Official Manual °'', 1), B84
3. p, B251. For example, propylene glycol is added to Chinese noodles, and is also used as a solvent for food flavoring, coloring, and preservatives, and has a weak bacteriostatic effect. , known as a medicinal additive (Ishibashi Shiki-1 “The whole picture of food additives”, p. 140-144 (1971), Takeji Ishibashi,
“Food Additives Guidebook”, p. 178 (1972)
Nankodo, Morizo Ishidate, “Food Additives Official Guidebook”, p.
B843 (1979). Glycerin is also known as a wetting agent and humectant for cakes, cakes, and castella cakes, or as an additive to sake, synthetic sake, marshmallows, chewing gum, gelatin desserts, meat products, and candy (Takeji Ishibashi, °゛Food Complete picture of additives °′, p, 1
20-123, I)・140・p・143(197
1'), Morizo Ishidate, ``Commentary of the Official Standards of Food Additives'', p.
, B251 (1979) Floor Bookstore]. D-Sorbitol (hexahydric alcohol) is used in vitamin preparations, amino acid preparations, castella cakes, cakes, nonan paste, yokan, sweetened soybeans, synthetic alcohol, mayonnaise, sausages, soft drinks, miso, soy sauce, vinegar, It is added to Narazuke etc. (Takeji Ishibashi, ``Food Additives Guidebook °'', p. 35
(1972) Nankodo, Morizo Ishidate, °°Food Additives Official Guidebook'', p, B589 (1,979')).

These polyhydric alcohols are also used in cosmetics, line drawings, lotions, ointments, tablet binders, etc.
, B846 C1979) Floor Bookstore, ``Supplementary Commentary on Standards for Cosmetic Ingredients'', p. 275, p. 261, p. 68 (1)
971) Yakuji Nipposha, Japan Cosmetic Industry Federation, “Standard Specifications for Cosmetic Ingredients,” p. 53, p. 56, p. 5.
9, p. 62 (1965).

In addition, 1,4-butanediol is said to have extremely low toxicity and is recommended for oral administration (oral administration).
LD of animal experiments by On)! ,ll (white mouse)
Ba2! It is generally recognized that its toxicity is extremely low, although it is far less toxic than propylene glycol and D-sorbitol. Therefore, as the water-soluble polyhydric alcohol of the present invention, the above-mentioned propylene glycol, glycerin, sorbitol, and 1°4-butanediol are particularly preferred.

The various water-soluble polyhydric alcohols described above are embedded in the hydrogel of the present invention to prevent the gel from air drying and hardening. The amount to be used is selected in consideration of the respective freezing points, etc., and the concentration in the raw material aqueous solution is 10 to 85 wt%, preferably 30 to 80 wt%. For example, even if the gel of the present invention obtained from an aqueous solution containing propylene glycol of fi35wt is air-dried at 37° C. for 120 days, there is almost no change in the elasticity, softness, softness, and suppleness of the gel. In addition, glycerin content 30wt% or glucose 32w
The gels of the present invention obtained from aqueous solutions of t%, mannitol 9wtq6, etc. have similar air drying resistance, and furthermore, since the freezing and hardening temperature of the water in these gels is below 0°C, Even when stored in a cool place, it retains its elasticity, flexibility, and suppleness.

In the present invention, in addition to the polyvinyl alcohol and water-soluble polyhydric alcohol, a highly viscous water-soluble polymer compound different from polyvinyl alcohol and having a 2 wt % aqueous solution viscosity of 300 cP (25° C.) or more is used.

By using a highly viscous water-soluble polymer in combination, the wet feeling on the surface of the gel obtained when polyvinyl alcohol contains only polyhydric alcohol can be somewhat reduced, and the user of the gel of the present invention can feel You can adjust the degree of moisture given to your skin depending on your preference. The contribution mechanism of the highly viscous water-soluble polymer in the present invention is not clear, but since this contribution is not significant when it comes to water-soluble low-molecular compounds, in the gel of the present invention, the viscous polymer aqueous solution The mass transfer (diffusion, flux) of polyhydric alcohol is significantly slowed down, and the water-soluble polymer blocks the pores in the hydrogel, suppressing the permeation of polyhydric alcohol. This is thought to be due to the fact that, with the exception of

In any case, as the water-soluble polymer in the present invention, well-known highly viscous water-soluble polymers are useful, excluding polyvinyl alcohol which has poor water retention, such as fLt, alginate propylene glycol ester, tragacanth gum, pullulan, Gum arabic, gum gathei, gum karaya, dextrin, starch, mucilage of yams, trolo mallow, Farcellella 7, car F” oran, methyl cellulone, guar gum, locust bean gum, xanthan gum, agar, carrageenan, ncoidan, alginic acid, alginic acid 1
Reethanolamine, pectin, agarose, carboxyl methylcellulose, tamarind gum, gelatin, polyacrylic acid, sodium polyacrylate, polymethacrylic acid, polyvinylsulfonic acid, polyvinylpyridine, polyethyleneimine, vinylimidazole-itaconic acid copolymer, A 2 wt% aqueous solution viscosity of 300 cP (25
C) or higher.

All of these have high molecular weights and their aqueous solutions are viscous, and all are useful in achieving the objectives of the present invention.

To illustrate the viscosity of the aqueous solution, sodium alginate 1.5wt%: 1.100cP, 2wt%:
3,730 cP, 3 wt%: 29,400 cP (
25℃), carragena 72wt%: 370cPs
3 wt%: 4,4. QOcP, 4 wt%: 2
5,356 cP (25°C), 0.5 wt% guar gum:
L350cP, 1wt%: 3,000cP, 5wt%
: 510,000cP (25℃), locust bean gum 2wt%: 1,100cP, 3wt%: 8.20
0cP, 5wt%: 120,0OOcP (25°C),
Alginate propylene glycol ester 1wt%:
400cP (25℃), xanthan gum 1wt%: 1,
100cP (25℃), -Carrageena 71.4wt%:
4+000 cP (25°C), an aqueous solution of a simple polyhydric alcohol, such as a 40 wt% aqueous solution of glycerin (
4.7 cP, 20°C), 50 wt% aqueous solution (6 cP, 2
0℃], 60 wt% aqueous solution (7,3CP, 30℃),
85wt% aqueous solution (112cP, 20℃), 90w
It is much more viscous than a t% aqueous solution (163 cP, 25°C). Among the well-known water-soluble polymers, polyacrylamide is not a particularly preferred material because there is a concern about the toxicity of the monomer (acrylamide) that remains, although it is a small amount.However, other materials generally do not have this concern, and for example, polyvinylpyrrolidone is a soft material. In addition to being famous as materials for contact lenses, dextran and alginic acid are also famous as plasma substitutes (Yamamura Yu - 11 New Medical Chemistry, p. 22 (198
1) Nankodo). Alginic acid is also used in ice cream, sherbet, soup, jam, cheese, cosmetics, etc., and carrageenan is used in pudding, jelly, can, ice cream, sherbet, yogurt, jam, and soup.

1. Casein is used in cheese, carboxymethylcellulose is used in ice cream, soup, and farcellan (f).
urcellaran) is also used in ice cream, pudding, jelly, and jam; guar gum is used in ice cream, sherbet, yogurt, and soup; pectin is used in ice cream, jelly, jam, and marmalade; starch is used in warabi mochi, udon noodles, and soup. , tamarind gum is used in Worcestershire sauce, pork cutlet sauce, sherbet, ice cream, jelly, and tragacanth gum.
th gum) is also used in ice cream, and alginate propylene glycol ester is also used in foods.
All of them are highly safe, as it is allowed to add less than %.

As described above, many well-known water-soluble polymers are useful in the present invention, but the texture, mechanical strength, elasticity, air drying resistance, etc. of the gel obtained by the treatment method of the present invention, which will be described later, are useful. In total, pullulan, xanthan gum, tragacanth gum, carboquine methylcellulose, polyacrylic acid, k
-Carrageenan, λ-carrageenan, propylene glycol alginate ester are preferred, and particularly preferred are carrageenan, propylene glycol alginate, λ-carrageenan, and polyacrylic acid.

Water-soluble polymers are generally concerned about bacterial contamination, but if necessary, food preservative additives such as sodium benzoate, carunium sorbate, p-ochynebenzoic acid derivatives, sthorium dehydroacetate, dehydroacetic acid, etc. Antibacterial agents can be used.

The amount of the above-mentioned highly viscous water-soluble polymer to be used is selected by taking into consideration the viscosity, solubility, moisture absorption and water retention properties, etc., or, as mentioned above, the concentration in the aqueous solution is 0.2 to 15 wt%.
, preferably adjusted to 2 to 5 wt%.

In the present invention, in order to prepare an aqueous solution containing polyvinyl alcohol, a water-soluble polyhydric alcohol, and a highly viscous water-soluble polymer, the hepvinyl alcohol, water-soluble polyhydric alcohol, and highly viscous water-soluble polymer are added and dissolved in water. In addition to the method of dissolving hevolinyl alcohol in water in advance, for example, the polyhydric alcohol (soak or its aqueous solution) and the highly viscous water-soluble polymer (the aqueous solution of salted tobacco) are mixed therein. Alternatively, a method can be adopted in which polyhydric alcohol and polyvinyl alcohol (or their aqueous solutions) are added and dissolved in a highly viscous water-soluble polymer aqueous solution.In either case, the final concentration of polyvinyl alcohol 1.5~Swt, polyhydric alcohol concentration 1
0-85wt%, high viscosity water-soluble polymer concentration 0.2-15
Adjust to wt%. In these cases, polyvinyl alcohol is poorly soluble in solvents other than water (D), so it is often in a dispersed state of transparent microgel particles ( (transparent suspended aqueous solution state), but this poses no problem in implementing the present invention.

In the present invention, an aqueous solution or suspension aqueous solution containing the polyvinyl alcohol, water-soluble polyhydric alcohol, and highly viscous water-soluble polymer is poured into a desired mold, cooled, and
Solidify and mold.

In this case, the coolant may be, for example, salt-ice (23 near 7) (-21°C), calcium chloride-ice (30 near 0)
Cryogens such as (-55℃), F-liquid inu methyl alcohol (-72℃), liquid nitrogen (-196℃)
Cool to a temperature lower than -6° C. using a solvent or the like. In addition, liquid helium can be used to cool the temperature down to -269°C, but it is uneconomical and does not improve the quality of the gel. good. Home refrigerator (freezer) Ice maker (-10~
There is no harm in cooling the sample by storing it at -20°C. This is followed by vacuum dehydration to obtain a solid gel. Note that insufficient cooling is not preferable for the present invention because the mechanical strength of the resulting gel is poor.

Therefore, in the present invention, an aqueous solution or suspended aqueous solution containing polyvinyl alcohol, a water-soluble polyhydric alcohol, and a highly viscous water-soluble polymer is heated to at least -16°C or lower, preferably -15°C or lower, and then Cool by vacuum dehydration.

A solidified body is obtained.

In the present invention, after the above-mentioned cooling treatment, the material is vacuum dehydrated without being melted. As the dehydration rate (weight reduction rate of the cooled and solidified gel) increases, the mechanical strength of the gel also improves, but if we consider its use as a cold storage gel,
It is not necessary to particularly increase the dehydration rate to obtain a strong gel;
More preferably, it is 15 to 70 wt% from the viewpoint of flexibility of the gel. The vacuum dehydration referred to herein means dehydration under reduced pressure, and the degree of reduced pressure is not particularly limited, but can be carried out, for example, at 10 mmHg or less, preferably 1 mHg or less, and further 0 or 1 mmHg or less. This dehydration step cannot be omitted. That is, unless this is carried out, it will not be possible to obtain the gel of the present invention which is highly elastic and has excellent mechanical strength, and as dehydration progresses, the gel strength will increase, and various properties such as non-viscous activity and water resistance will not be obtained. This partial dehydration treatment is indispensable to the present invention because it significantly improves. However, in the present invention,
Freeze-drying of injectable liquids or coffee, milk, fruit juice,
There is no need to carry out the extensive dehydration (drying) treatment that is seen in the freeze-drying of water-containing foods such as noodles, and the purpose of the present invention is fully achieved by the partial dehydration treatment as described above, and the dehydration progresses as described above. Since the gel strength increases as the gel strength increases, the amount of dehydration can be selected depending on the desired gel strength. In any case, this partial dehydration treatment is essential to the present invention and has extremely important significance, so if it is omitted, the non-flowable, non-adhesive, highly water-containing and A crack-free gel with excellent mechanical strength can never be obtained.

The gel after vacuum dehydration is a milky white opaque gel, but it is a solid gel that is insoluble in water even at room temperature and cannot be stored in a home refrigerator (
It will not harden even in the ice maker of a freezer.

In the present invention, the shape of the injection container or mold for the mixed aqueous solution or suspension aqueous solution of polyvinyl alcohol, water-soluble polyhydric alcohol, and highly viscous water-soluble polymer is arbitrarily selected, and the desired shape (granular, film-like, lump-like) is obtained. , plate-like, cylindrical or other arbitrary shapes). It may be molded to match the shape of the final object, or the molded body once obtained may be molded into another shape by cutting or the like.

Although the gel of the present invention contains a large amount of water-soluble polyhydric alcohol, highly viscous water-soluble polymer, and water, it is superior to agar, alginic acid, carrageenan, guar gum, locust bean gum, and agarose in terms of mechanical strength. It is far superior to polysaccharide gels such as konjac or protein gels such as tofu and jelly, and is rather similar to the muscular structure of humans and animals. Even if you squeeze it tightly, it will temporarily deform, but it will immediately return to its original shape. , does not lose its shape. Even when pressure is applied to the gel of the present invention, the liquid contained therein does not leach out; for example, 8Kj9/crn
Even if a compressive stress of This gel was immersed in physiological saline for one year, but it did not dissolve, and its elasticity and strength remained almost unchanged (this is because
This is in sharp contrast to, for example, konnyaku, which severely loses its shape when soaked for several days).

In the present invention, polyvinyl alcohol is used as a gel material (
used as a gelling component). However, there is no problem in the coexistence of other inorganic or organic substances that do not inhibit the gelation of polyvinyl alcohol, and the amount thereof can be, for example, 1/2 weight or less of the polyvinyl alcohol.

The texture of the gel of the present invention is similar to human meat, animal meat, squid sashimi, fish meat, rice cake, chikuwa, hanpen, sausage, and fish. Therefore, the gel of the present invention has a feel similar to that of living tissue, and is therefore highly elastic.
It has the advantage of being soft to the touch and not sticking to living tissue.

Since the gel itself has a feel similar to living tissue, it can be used as a highly elastic cold pack, such as ice pillows and ice bag substitutes, and can be used in household refrigerators (freezers).
Even in the ice making room, it does not freeze or harden, and always exhibits a fresh texture and konnyaku-like elasticity.

The gel of the present invention may be used while being packaged or sealed in a bag made of transparent or opaque soft film such as polyvinyl chloride, polyethylene, or polypropylene, or it may be used in sweet packaging or without being sealed. You can also do that.

The gel of the present invention can be used as an ice pillow or ice bag substitute as described above, and can also be used in cancer chemotherapy.
Alopecia as a side effect in py
It can also be used in a head cooling gel used to prevent a). This head cooling gel is used to treat cancer patients with anticancer drugs (c).
administration (arcinostatics)
It is suitable for use for the purpose of preventing hair loss due to the use of antibiotics.
Daunomycin is frequently used as
n) i.e. Daunorubicin
Alternatively, Adriamycin, i.e. 14-hydroxydaunorubicin (I-'xorubicin)
It can be of great utility in preventing and inhibiting severe hair loss as a side effect of drugs such as icin and doxorubicin. Among these, adriamycin shows particularly excellent therapeutic effects against a wide range of cancers.
It is often noted as an important anticancer agent, but it is also well known that it is extremely toxic. For example, administering adriamycin every 25 days (depending on the patient's level of understanding of medicine, this can lead to serious problems that may lead to distrust of medical care).

The cause of this hair loss appears to be that antibiotics administered into the body are absorbed into the hair cell tissue, and in order to suppress this absorption rate, the metabolism of the living cells is significantly reduced (2
Efforts have been made to cool hair cells to about 5°C. The administered antibiotic reaches the head after a few minutes,
Since the drug leaves the head within 30 to 40 minutes and is barely detected in the bloodstream of the head thereafter, specific methods have been sought to cool the head for approximately 40 minutes after administration.

In other words, there is a method of wrapping an ice pack around the head, a method of helmet made of sponge impregnated with a large amount of cold water, and a method of wearing a hat in the hollow part of a hat made of a hollow bag made of vinyl chloride.
Attempts have been made to encapsulate jelly, agar, polyvinyl alcohol/borax gel, etc. However, with the ice pack method, water and ice flow down to the bottom of the bag wrapped around the head due to gravity and become unevenly distributed, making it difficult to cool the entire head uniformly.Also, sponge helmets do not retain water. lacking in ability,
There are practical problems such as large amounts of cold water leaking and dripping. In the method of sealing high water content gel as a cooling medium into the hollow part of a hollow cap made of a polyvinyl chloride bag, conventionally known high water content hydrogels are either fluid (polyvinyl alcohol/borax gel, carboxymethylcellulose gel) or Since it is a soft or brittle solid (agar, jelly, carrageenan, alginate gel), it is difficult to maintain its shape (helmet shape), and it also has poor elasticity, making it difficult to fit tightly onto the head. In order to prevent the cooling medium from deforming and becoming unevenly distributed, perforations were made vertically and horizontally over the entire surface of the hollow bag type helmet (many small sections were created) to prevent the internal filling from moving. An attempt (Japanese Patent Laid-Open No. 140107/1983) was proposed in which a large number of independent vesicles (internal chambers) were installed in the helmet and a cooling medium was sealed in each one, but the problem was that the helmet itself lacked elasticity and the head It lacks practical value because it does not adhere to the entire surface of the part and creates gaps.

A1'1) As a measure to prevent hair loss as a side effect of amycin, a method has been proposed in which the scalp is tightened with a rubber band and administered, but consideration must be given to the cruel pain that would be caused to the patient by applying external pressure to the head. If so, this attempt is not at all desirable.

The drawback of the above-mentioned head cooling method is that it is not possible to obtain a cooling material with appropriate properties, that is, a high water content gel (hydrogel) that has rubber-like elasticity and mechanical strength that can maintain the shape of the helmet. Attributable to

According to the present invention, an aqueous solution or suspended aqueous solution containing polyvinyl alcohol, a water-soluble polyhydric alcohol, and a highly viscous water-soluble polymer is injected into a mold for molding a helmet, and the head is cooled, solidified, and molded. You can create cold gel.

In this case, the shape of the helmet should not only cover the entire scalp, but also the hair on the left and right sides of the head.
It would be desirable to be able to cover the eyebrows as well, and it would be inappropriate to simply use a helmet for work sites or a helmet for batters in baseball. Added the following corrections.

A helmet made of the gel of the present invention can be easily manufactured.

In the present invention, the helmet-like gel thus obtained can be used as it is (that is, without being packaged or sealed in a bag made of polyvinyl chloride, polyethylene, polypropylene, etc.) as a helmet for keeping the head cool. The feel of the hydrogel of the present invention can be directly transmitted to the head, and since this hydrogel has high stretchability (elasticity), it can accommodate a wide range of head sizes and shapes, and always achieves sufficient dense activation. In other words, compared to the case where jelly, glue-like synthetic gel, etc. are sealed in a bag made of polyvinyl chloride or rubber, as described above, a hydrogel with a konnyaku-like (or kuzumochi-like) feel can be directly attached to the head. It is clear that the coating of the present invention is much more in accordance with the ergonomic treatment philosophy.In particular, in the present invention, the IS mouth gel embedded with glycerin and propylene glycol (Kawatake ethylene glycol) has a water-retaining effect. Even if a small amount of water evaporates, it is a polyhydric alcohol-embedded gel with excellent water retention properties, so it avoids dry stiffness and remains flexible and elastic. Furthermore, the mechanical strength that does not lose its shape and the excellent feel (touch), that is, the initial fresh appearance and feel are maintained, and the most favorable effects are exhibited.

In the present invention, polyvinyl alcohol, which is recognized as a cosmetic raw material
p. 279 (1971) Yakuji Nipposha) and foods,
Is it approved as a food additive, cosmetic raw material, etc.?
Or at least, it is characterized by the fact that an excellent hydrogel can be obtained from a water-soluble polyhydric alcohol that is harmless to the human body (skin, hair) without using any chemical reagents or organic solvents. It goes without saying that it is undesirable to mix harmful substances such as talc (slaked stone), bentonite, and silica, which are well-known as solvents or dispersion media for cosmetic raw materials, oral medicines, and liniments applied to the skin (or skin wounds). Aluminum acid, etc. (Takeji Ishibashi, “The Complete Story of Food Additives” p.
138 (1971') Nankodo, Takeji Ishibashi, °゛Food Additives Guidebook'' p, 174 (1972) Nankodo, ゛'Cosmetic Ingredient Standards Supplementary Commentary II p, 260 (1971
)Yakuji Nipposha, ``Japanese Pharmacopoeia'' (1976), ``Japanese Pharmacopoeia'' (1976), may be added to the extent that it does not affect the gel strength.

In the present invention, an antibacterial agent is added to the mixed aqueous solution of polyvinyl alcohol, water-soluble polyhydric alcohol, and highly viscous water-soluble polymer from the viewpoint of hygiene, for example, from the viewpoint of disinfecting or bacteriostasis of germs in the hair. can do. Thereafter, by similarly applying the above-described gelling method of the present invention (cooling, solidification, vacuum partial dehydration), a helmet with high elasticity and good texture can be obtained.

Antibacterial agents that can be used in these cases include, for example, sulfadiazine + silver sulfadiazine.
), benzalkonium chloride
um chloride) % cetalkonium chloride
, methylbenzethonium
onium), neomycin sulfate (neomycin
5u1fate), hexachlorophene (hexach
lorophene), eosine, penicillin G, cephalothin (cephalothj, n), cephalorldine, tetracycline (
tetracycline) % lincomycin (li
ncomycin), nystatin
), kanamycin (kanamy-cin), penicillinase-resistant penicillin (penicilli+-+n
ase-reeistant penicillin)
, fradiomycin 5
ulfate), silver lactate (8i1ver1acta4
;e) may be used alone or in combination.

-j7-
, ,,.

Among antibacterial agents, for example, the solubility of sodium sulfadiazine in water is as high as 50 wt%, but only 1 g of sulfadiazine is dissolved in 1.3.0007 g of water. However, in the present invention, the antibacterial agent does not necessarily need to be used as an aqueous solution, but a powder or a suspension thereof is added to the above-mentioned mixed aqueous solution of polyvinyl alcohol, water-soluble polyhydric alcohol, and high viscosity water-soluble polymer. By this, it can be embedded in the gel of the present invention.

In the present invention, the amount of antibacterial agent added to the mixed aqueous solution of polyvinyl alcohol, water-soluble polyhydric alcohol, and highly viscous water-soluble polymer can be 1/2 weight or less of the polyhydric alcohol, such as sulfuric acid Mycin 0.2
-4 wt%, sulfadiazine 1-25 wt%, penicillin G O, 2-1 wt%, etc. The antibacterial agent embedded in the gel of the present invention is not washed away in a short period of time, but is embedded and sustainedly released over a long period of time. For example, after dissolving 3 wt% of sodium sulfadiazine in a mixed aqueous solution of polyvinyl alcohol and polyhydric alcohol, 3 g of sodium sulfadiazine was applied to the head of an adult (male) for 40 minutes using a helmet obtained by applying the treatment of the present invention. Even after repeating the coating operation 80 times, 95% of the zulfadiazine sodium content in the helmet remained, and the inner surface of the helmet (
No germs were detected in the areas that came into contact with hair and skin.

In the present invention, by cooling, assimilating, molding, and partially dehydrating an aqueous solution or suspended aqueous solution of polyvinyl alcohol, a water-soluble polyhydric alcohol, and a highly viscous water-soluble polymer, the gel is completely different from conventionally known polyvinyl alcohol-based gels.
The reason why hydrogels with excellent mechanical strength, high elasticity, and good texture are obtained is not clear, but during cooling, solidification, molding, and the subsequent partial dehydration treatment, extremely large numbers of molecules within and between polyvinyl alcohol molecules are formed. This is thought to be due to the formation of hydrogen bonds, which increases the crystallinity of the gel structure and improves mechanical strength and elasticity, especially during partial dehydration.

In any case, this kind of polyvinyl alcohol cooling
The partially dehydrated gel and its manufacturing method were discovered for the first time by the present inventor.

The polyvinyl alcohol gel of the present invention contains polyvinyl/l
/ 7 Le: 7-le fiber or polyvinyl alcohol
By subjecting the film to a known curing treatment, the mechanical strength of the gel can be further increased.

This known curing (crosslinking) treatment includes, for example, aldehyde 1? , dialdehyde 1:'', diisocyanates, phenols, or metal compounds such as titanium, chromium, and zirconium, as well as borax, acrylonitrile, trimethylolmelamine, shrimp chlorohydrin, and bis(
Examples include methods using β-hydroxyethyl) sulfone, polyacrylic acid, dimethylol urea, maleic anhydride, and the like. However, since the gel of the present invention has the strength as described above, these secondary curing treatments are not particularly necessary.

As already mentioned, the hydrogel helmet of the present invention has the following features:
When it comes into contact with living tissue, it is non-irritating, does not stick to hair or skin, and has a soft texture and sufficient mechanical strength and elasticity, and it adheres closely to the head. By cooling the scalp in a refrigerator (freezer) in advance and then wearing it on the head, the scalp can be cooled to a desired temperature of 20 to 25° C. when necessary, such as when administering an anticancer drug.

'T1, according to the present invention, a gel obtained from an aqueous solution or suspended aqueous solution containing polyvinyl alcohol, a water-soluble polyhydric alcohol, and a highly viscous water-soluble polymer is used in a part that comes into contact with the human body, and at the same time, It is also possible to manufacture a composite layer type cold-retaining gel using a freezing/rigid cold-retaining gel made only of other materials such as polyvinyl alcohol on the side that is not covered. The composite layer type cold-retaining gel can also be used in a state where it is packaged or sealed in a bag made of transparent or opaque flexible film such as polyvinyl chloride, polyethylene, polypropylene, etc.

It may also be used without such packaging or encapsulation.

Examples of the present invention will be described below.

Example 1 Saponification degree: 99.5 molar ratio, viscosity average polymerization degree: 2,600.
100 g of polyvinyl alcohol with a 4% aqueous solution viscosity (20°C) of 67 cP was dissolved in 90 g of water, mixed with 440 g of ethylene glycol and 60 g of λ-carrageenan, poured into a helmet mold, and heated at -40°C for 80 g.
h After cooling, it was immediately subjected to vacuum dehydration to remove 200 g of water (dehydration rate: 13 wt), and then allowed to stand at room temperature to melt.

The helmet obtained in this way has a light brown color, but
It is highly elastic and flexible, and has sufficient mechanical strength to be attached and taken off as a helmet.
℃) overnight, it did not freeze or harden, and almost retained its original flexibility and elasticity.

This was left at room temperature, and when Q'C was reached, it was placed on the head of an adult and placed in the horizontal position.
5upine position) As a result,
After 8 min, the scalp temperature reached 20-22°C and was then maintained at 20-25°C for 33 min. The composition of this helmet is - 7.5 wt% polyvinyl alcohol;
The contents were 33.4 wt% propylene gellicol, 4.6 wt% λ-carrageenan, and 54 wt% water.

Example 2 Saponification degree: 99.5 mol%, viscosity average degree of polymerization: 2,600.
A suspended aqueous solution consisting of 68 g of polyvinyl alcohol (water content 7 wt%) with a 4% aqueous solution viscosity (20°C) of 67 cP, fluoropylene gelicol IKP, 16 g of fluoropylene glycol fulgate, and 920 g of water was heated at 120°C.
An aqueous solution of 3.2 wt % polyvinyl alcohol, 5 Q wt % propylene glycol, and 8 wt % alginate propylene glycol ester Q was prepared by subjecting it to pressure steam sterilization for 30 min and then stirring in a sterile room to uniformly dissolve it. I got it.

This aqueous solution 2 K9 was injected into a helmet molding mold, left to cool at -350 for 6 hours, immediately subjected to vacuum dehydration to remove 230 g of water (dehydration rate: 12 wt%), and then left at room temperature to melt. Ta.

The helmet obtained in this way has a light brown color, but
It is highly elastic and flexible, and has sufficient mechanical strength to be worn as a helmet.
) for one night, but it did not freeze or harden and retained its original flexibility and elasticity. Leave this at room temperature and O1
'? : When the temperature reached 9 m1, the scalp temperature reached 20 to 22°C and was maintained at 20 to 25°C for 38 m1.

Example 3 Saponification degree: 97.5 mol%, viscosity average degree of polymerization: 2.200.
4% aqueous solution viscosity (20°C) 560P polyvinyl alcohol 53g (water content 7wt%), glycerin I K9
, i-Carragena/109g (water content 8wt%), water 84
A suspended aqueous solution consisting of 0g was subjected to pressure steam sterilization at 120°C x 35ml, and then stirred in a sterile room to uniformly dissolve it. % aqueous solution was obtained.

1,900 g of this aqueous solution was placed in a steam-sterilized stainless steel helmet mold (helmet depth approximately 21 cm, outer diameter approximately 17 m, thickness approximately 2 cm).
m), left to cool at -30°C for 9 hours, and immediately subjected to vacuum dehydration to remove 220 g of water (dehydration rate 12 wt%).
Next, it was allowed to stand at room temperature to melt.

The helmet obtained in this way has a light brown color, but
It is highly elastic and flexible, has sufficient mechanical strength to be attached and taken off as a helmet, and can also be used in refrigerator ice compartments (-5 to -2
Although it was placed in a calving device at 0°C, it did not freeze or become rigid, and maintained its original flexibility and elasticity. Leave this at room temperature,
When the temperature reached 0°C, the child (8 years old) was placed on the head and placed in a supine position. After 8 min, the scalp temperature was 1 - 1 l.
: Reached 20~22℃, then 20~22℃ for 38 min.
The temperature was maintained at 25°C.

Comparative Example 1 In Example 3, aqueous solution 1 of polyvinyl alcohol, glycerin, and 1-carrageenan was added to the helmet molding mold.
, 900 g was injected, and after being left to cool at -40°C for 24 hours, it was allowed to stand at room temperature and melt without performing the partial dehydration operation of the present invention.

When the molded product is taken out of the mold, the edges are too soft to stand upright on a desk, and it is extremely sticky, making it extremely uncomfortable to wear when forced to wear it. It was confirmed that it easily fell out of the hand and was easily damaged.

That is, the usefulness of the cooling/vacuum partial dehydration operation of the present invention is obvious.

Example 4 Polyvinyl alcohol (saponification degree 99.1 mol%, viscosity average polymerization degree 2.40 0.4% aqueous solution viscosity (20 ° C.) 6
A mixed suspended aqueous solution of 108 g of powder (moisture content: 7 wt%) of 0CP), 100 g of glycerin l Ky, 100 g of λ-carrageenan, and 790 g of water is subjected to pressure steam sterilization at 120°C for 35 min, and then stirred in a sterile room. Polyvinyl alcohol 2. ．． An aqueous solution containing 5 wt% of glycerin, 50 wt% of glycerin, and 5 wt% of λ-carrageenan was obtained, and to this was added 100π of butyl ξ-hydroxybenzoate.
y (equivalent to 50 ppm) and fradiomycin sulfate powder 10
g (equivalent to 5+0 OOPp'') was dissolved.

This aqueous solution was applied to a stainless steel helmet molding mold (helmet depth: approx. 23 tyn, outer diameter: approx. 2 mm).
Q cwr , about 2 cm thick), -35
After cooling at ℃ for 9 hours, vacuum dehydration was immediately performed to reduce water content to 210 g.
was removed (dehydration rate: 10 wt%), and then allowed to stand at room temperature to melt.

The helmet obtained by this will have a light brown color or
It is highly elastic and flexible, has sufficient mechanical strength to be attached and taken off as a helmet, and can also be used in refrigerator ice compartments (-5 to -2
Although it was left at 0°C overnight, no freezing or hardening was observed, and the original flexibility and elasticity were maintained. Leave this at room temperature and
Once the temperature reaches ℃, it is placed on the head of an adult and placed in a horizontal supine position (
horizon-talsupine position
n) After 9 minutes, the scalp temperature was 2.
1~23c, then 21~25℃ for 37m1n
was maintained.

Example 5 Saponification degree: 97.5 mol%, viscosity average degree of polymerization: 2,200.
Viscosity of 4% aqueous solution (20°C): 86 g of polyvinyl alcohol (water content: 7 wt%), 56 cP, glycerin: 1.
600 g, 1-carrageenan 173 g (moisture content 8 wt%
) + 1,344 g of water, 1 (IITF acid A Lomomysi =
y (paromo-mycin 5 ulfate)
A suspended mixed aqueous solution of 16 g of powder was subjected to pressure steam sterilization at 120° C. Carrageenan 5wt%, paromomycin trichloride 5,000 ppm
An aqueous solution of was obtained. This water-soluble i3. IKP was used as a helmet mold (helmet depth approx. 25m, outer diameter approx. 22cm)
, about 2 cm thick), left to cool at -40°C for 6 hours, immediately subjected to vacuum dehydration to remove 200 g of water (dehydration rate: 6.5 wt%), and then allowed to stand at room temperature to melt. .

The helmet thus obtained has a light brown color, but is highly elastic and flexible, and has sufficient mechanical strength to be attached and detached as a helmet.
℃) overnight, no freezing or hardening was observed, and the original flexibility and elasticity were maintained. Leave this at room temperature and
Once the temperature has reached ℃, it is placed on the adult's head and placed in a semi-prone position (8°C).
As a result, the scalp temperature reached 21-23°C after 9 min, and was maintained at 21-25°C for 39ml thereafter.

Example 6 Saponification degree: 99.5 mol%, viscosity average degree of polymerization: 2,600.
4% aqueous solution viscosity (20°C) 67 cP polyvinyl alcohol 144 g (water content 7 wt%), glycerin 1.75
0 g, fulgic acid furopylene gelicol ester 1
75g1. o Rahi! S Roquin Anshikikoate n-butyl 0.
35g, 'tL colistin powder 17.5g, water 1
．． 4188 at 120°C x 25 m
7-team sterilization under pressure, followed by stirring in a sterile room to uniformly dissolve polyvinyl alcohol 4wt%, chrycerin 50wt%, alginate phlopylene glycol ester 5wt%, para-hydroxybenzoic acid n- Butyl 100,. 1:) l) m, value acid colistin 5. An aqueous solution of OOOppm was obtained. , 3,400 g of this aqueous solution was poured into a stainless steel helmet mold (helmet depth: approx. 26 mm, outer diameter: approx. 22 m, thickness: approx. 20 mm), and after cooling at -40°C for 8 hours, it was immediately vacuumed. It was dehydrated to remove 325 g of water (dehydration rate 9.5 wt%), and then allowed to stand at room temperature to melt.

The helmet obtained in this way has a light brown color, but
It is highly elastic and flexible, has sufficient mechanical strength to be attached and taken off as a helmet, and is suitable for cold refrigerator ice making compartments (-5℃~-
Even when left overnight at 20° C., no freezing or hardening occurred, and the original flexibility and elasticity were maintained. Leave this at room temperature,
When the temperature reaches 0°C, it is placed on the head of an adult and placed in a supine position at head height (h, ea, delevate 5upine po
As a result, the scalp temperature reached 21 to 23 °C after 8 min, and then 21 to 23 °C for 38 min.
The temperature was maintained at ~25°C.

Procedural amendment (voluntary) September 70, 1981 Patent Application No. 135230 2, Title of invention Method for manufacturing cold gel 3, Relationship with the case of the person making the amendment Name of patent applicant (name) (444) Nippon Oil Co., Ltd. Address
Toranomon Jitsugyo Kaikan 5, Date of amendment order 6 Number of inventions increased by amendment 7 Supplementary fO subject Item 8 of "Detailed explanation of the invention" of the specification Contents of the amendment As shown in the attached document, "Details of the invention" in Mei #I The section "Explanation" has been amended as follows.

Claims (1)

[Claims] polyvinyl alcohol with a saponification degree of 95 molar coefficient or more and a viscosity average polymerization degree of 1,500 or more; a water-soluble polyhydric alcohol having 2 to 6 carbon atoms and having 2 to 6 hydroxyl groups in the molecule;
Sarani Id, HolJ Hinyl alcohol toha different, 2w
a highly viscous water-soluble polymer with a t-related aqueous solution viscosity of 300 cP (25°C) or more, and the concentration of the polyvinyl alcohol, the water-soluble polyhydric alcohol, and the water-soluble polymer is 1.5 to 8 wt%, respectively. , 10-85 wt%, and 0.
The aqueous solution adjusted to 2 to 15 wt% is cooled and solidified at a temperature lower than -6°C, and then the dehydration rate is 5 w.
A method for producing a cold-retaining gel, which comprises performing vacuum dehydration of t% or more and 95wt% or less.