JPS61168350A - Water pillow - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a water pillow, more specifically -30 to -40°C.
This is an excellent water pillow that does not lose its flexibility even at extremely low temperatures.

(Conventional technology) Conventionally, water pillows filled with ice have been used to reduce heat generation, and these traditional water pillows lose their effectiveness because the ice easily melts. A cushion body impregnated with a mixture of water and a polyhydric alcohol such as ethylene glycol is inserted into a water pillow container.

(Problem to be Solved by the Invention) The water pillow of the prior art as described above is used after being frozen in a refrigerator, etc., but the contents lose flexibility due to freezing and the feeling of use is very poor. Moreover, when it is thawed, it gives a mushy feeling, and in any case, it is inferior in usability.

As a result of intensive research to solve the drawbacks of the prior art as described above, the present inventor has found that when a specific material is used as the content of a conventional water pillow, the drawbacks of the prior art described above are resolved and the feeling of use is improved. The present invention was completed after discovering that an excellent water pillow can be obtained.

(Means for Solving the Problems) That is, the present invention provides a water pillow whose contents are frozen for use, and which includes a water-swellable polymer whose contents expand by absorbing a solution of a water-soluble substance and water. This water pillow is characterized by being a small-sized product made of polyurethane elastomer and polyurethane elastomer.

Next, to explain the present invention in more detail, the polyurethane elastomer used in the present invention and which primarily characterizes the present invention may be a conventionally known polyurethane elastomer, preferably one obtained in the production of a polyurethane elastomer. Introducing wood-philic groups such as hydroxyl groups, carboxyl groups, sulfonic acid groups, amide groups, etc. or their bases into the side chains of the polyurethane elastomer;
Alternatively, it can be obtained by introducing a wood-philic segment such as a polyoxyethylene chain into the main chain.

According to detailed research by the present inventors, by introducing the above-mentioned wood-philic groups and/or hydrophilic segments into polyurethane elastomers, the resulting polyurethane elastomers become wood-philic depending on the amount introduced, and finally However, the polyurethane elastomer useful in the present invention is made hydrophilic to the extent that the resulting polyurethane elastomer has sufficient water resistance by limiting the amount of woody groups and/or woody segments introduced. In other words, it needs to be water-insoluble and wood-loving.

In the present invention, it has been discovered that such a water-insoluble and hydrophilic polyurethane elastomer has sufficient water resistance when molded into a small shape, and also has unexpectedly excellent water permeability. This is what I did.

The water-insoluble and hydrophilic properties of such polyurethane elastomers vary significantly depending on the type of hydrophilic groups and/or wood-philic segments introduced, so the amount of these hydrophilic groups and/or wood-philic segments introduced depends on Although it cannot be absolutely defined, the introduction of hydrophilic groups and/or hydrophilic segments can be easily carried out using conventionally known techniques, and the amount of introduction can be very easily adjusted. Alternatively, a person skilled in the art can easily experimentally obtain and determine the preferable amount of the wood-loving segment to be introduced.

The water-swellable polymer used in the present invention and which secondly characterizes the present invention is a polymer that absorbs water and swells when it comes into contact with water, but is not soluble in water, such as starch-polymer. Sodium acrylate grafted product, starch
Saponified product of polyacrylonitrile grafted product, cellulose-sodium polyacrylate, vinyl alcohol-
Sodium (meth)acrylate-(meth)acrylic acid copolymer, crosslinked sodium poly(meth)acrylate, alkali neutralized product of crosslinked isobutylene-maleic anhydride copolymer, sodium salt of crosslinked carboxymethyl cellulose,
Any of the conventionally known materials can be used, such as crosslinked polyethylene oxide and polyurethane containing polyoxyethylene chains.

Particularly preferred water-swellable polymers include, for example, JP-A-54-
No. 47796, No. 54-83091, No. 54-839
No. 89, No. 54-87791, No. 54-108895
(Hydrophobic polymer segment) described in the publication, etc.
It is a block copolymer having a (hydrophilic polymer segment)-(hydrophobic polymer segment) bonding format. The most preferred among such block copolymers are those in which the hydrophilic group of the wood-philic polymer segment is an alkali metal salt of carboxylic acid or sulfonic acid.

The small-shaped object used in the water pillow of the present invention is formed using the specific materials mentioned above, and the water-swellable polymer and polyurethane elastomer used are water-swellable in the resulting small-shaped object. It is preferable to use the polymer in a proportion of about 30 to 90% by weight; if the amount of water-swellable polymer used is less than about 30% by weight, the liquid absorption and liquid retention properties of the resulting small-sized product will be poor. Moreover, if the amount of the water-swellable polymer used exceeds 90% by weight, the feel of small objects in the liquid-absorbed state will be poor, which is not preferable.

Moreover, the small-shaped objects used in the present invention are specifically in the shape of a thin string, a small piece, a small sheet, a small ring, and a small tube, and particularly preferred are thin string-like objects. .

Next, a method for preparing small-sized objects from the above-mentioned materials will be explained, and the present invention will be explained in more detail.

That is, the most preferred method is to prepare the polyurethane elastomer with methyl ethyl ketone, methyl-n-propyl ketone, methyl isobutyl ketone, diethyl ketone,
Methyl formate, ethyl formate, propyl formate, methyl acetate,
Ethyl acetate, butyl acetate, acetone, cyclohexane,
Tetrahydrofuran, dioxane, methanol, ethanol, isopropyl alcohol, butanol, methyl cellosolve, butyl cellosolve, cellosolve acetate,
Dimethylformamide, dimethyl sulfoxide, pentane, hexane, cyclohexane, heptane, octane,
Mineral spirits, petroleum ether, gasoline, benzene, toluene, xylene, chloroform, carbon tetrachloride,
Prepare a solution or dispersion of the organic solvent by dissolving or dispersing it in an organic solvent such as chlorobenzene, perchlorethylene, trichlorethylene, etc., and dissolve or disperse the water-swellable polymer in the required amount in this solution. .

A method in which the solution or dispersion obtained in this way is caused to flow down, extrude or jet from a discharge device having one or more nozzles into water or into an organic solvent different from the organic solvent of the above-mentioned solution or aliquot. .

By such treatment, the solution or dispersion of the water-swellable polymer and the polyurethane elastomer hardens and coagulates into preferred strands having a very large surface area.

The preferred thin strand-like material thus obtained has a very large surface area and is formed in a crumpled state, so that it maintains excellent elasticity, liquid absorption and liquid retention properties.

The thickness of such a thin string-like material is preferably about 0.1.

The length is preferably about 5 cm, and the length is arbitrary, but generally about 1 to 20 cm is advantageous for use.

In such a preferred production method, the preferred thin strands used in the present invention can be prepared even if an organic solvent that is immiscible with water is used as the organic solvent of the solution or dispersion.
Also, organic solvents that are partially or completely miscible with water may be used.

It was completely unexpected that even when using an organic solvent that is immiscible with water, it was possible to coagulate and mold such a desirable thin strand-like product.This was made possible because the polyurethane elastomer is hydrophilic and This is thought to be due to the use of a water-insoluble polyurethane elastomer.

That is, for example, when a solution or dispersion is poured into water, the water-swellable polymer and/or polyurethane elastomer contained in the solution or dispersion absorbs surrounding water and coagulates into a gel. This is thought to be due to separation from the organic solvent of the dispersion. Therefore, in such a manufacturing method, the productivity can be greatly increased by using a relatively quick-drying organic solvent.

Furthermore, when an organic solvent that is miscible with water is used as an organic solvent for a solution or dispersion of a water-swellable polymer and a polyurethane elastomer, it will easily coagulate into a preferable thin string in water, and the resulting preferable thin string Since the polyurethane elastomer in the form is microporous, it has even better liquid absorbency, liquid retention, and feel.

Another molding method is to apply a solution or dispersion of a water-swellable polymer and a polyurethane elastomer as described above to any six substrates, such as a glass plate, a metal plate, or various plastic films with mold releasability. A method of coating in multiple strips with a width of about 0.5 to 20 mm and a dry thickness of about 5 to 5004 m, drying, and then peeling; Although a method of kneading in the presence or absence of a solvent and extrusion molding may also be used, the most preferred method is the above-mentioned coagulation method.

In the present invention, the small-sized article obtained as described above is impregnated with an aqueous solution of a substance such as urea, sucrose, alcohol, polyhydric alcohol, such as ethylene glycol, propylene glycol, glycerin, etc., and expanded. , is characterized in that the expanded body is used as the content of the water pillow. Any water-soluble substance may be used, but the most preferred one is a polyhydric alcohol, such as ethylene glycol. Further, the mixing ratio with polyhydric alcohol is such that the polyhydric alcohol is about 10 to 80% by weight in the mixture at a 1 weight ratio.

Further, the rate at which the small-shaped object is expanded by such a mixed liquid is preferably such that the small-shaped object becomes about 5 to 50 times its own weight.

The present invention has the above-mentioned points as the main features of the complete u11, and the container for storing the expanded small-shaped object as described above is similar to the conventional water pillow container, for example, made of rubber or plastic. , or a composite of these and a woven fabric, etc., and their shapes and other features may be the same as those of conventionally known water pillows.

(Functions and Effects) The water pillow of the present invention as described above has a water pillow in which a mixture of a water-soluble substance as a refrigerant and water does not exist in a free state.
Since it is absorbed and contained in a small elastic object, even if it is frozen at an extremely low temperature of -30 to 40 degrees Celsius in a refrigerator, it will not lose its flexibility due to the small object with good cushioning properties. It has a very good feel when used, and even if the contents thaw during use, it does not give a mushy feeling like conventional water pillows.

Next, the present invention will be specifically explained with reference to Examples. Note that parts and percentages in the text are based on weight.

Example 1 54 parts of a water-swellable polymer and 144 parts of a 25% polyether type polyurethane elastomer solution (Heimlen N PU-1 Ukima Gosei Co., Ltd.) were mixed with 162 parts of an organic solvent (ethyl acetate: toluene: isopropyl alcohol). 50:3
0:20) to obtain a dissolved dispersion. 20 to 30 c of sodium chloride is slowly and intermittently flowed down into the stirring water in the form of a thread. By repeating this operation, thin string-like substances are precipitated. When this is washed with water and dried, it becomes approximately 5 to 10cm long.

This thin string-like material was made to absorb ethylene glycol (EG) + water-based solvent and placed in a rubber bag to form a water pillow of the present invention.

Table 1 shows the state of this water pillow when it was left in a home freezer (-12°C) for one week.

ri 1 1 dan mrv 1 0/100 0 25.3 X hardens 2
10/9G -3,228,5X Harden 3
20780 -7.4 22.8 X Harden 4
30/70 -12.8 to 24.1 Sherbet-like 5 4078G -20,024,10 Good cushioning 6 5G15G -29,924,00
Good cushioning properties 7 130/4G -44,824
,00 Good cushioning properties 8 7073G -138,
725,20 Good cushioning 9 0/10G--3,
80 No cushioning Note 1. Mixing ratio of EG and water ■: Freezing point of solvent (theoretical value) m: Degree of water swelling (times) ■: Condition after being left in a -12°C freezer Judging from the results of E, the water pillow of the present invention has EG -Exhibits excellent liquid absorption properties in a wide range of aqueous systems, and also maintains excellent liquid absorption properties even after freezing.

The above water-swellable polymer is (polystyrene)-(
It is a block copolymer (polystyrene content 25%) with a bonding format of polybutadiene)-(polystyrene) in which sodium 1,000-oglycolic acid is added to the unsaturated double bonds, and when used alone, it absorbs about 100 times its own weight in water. It swells.

Example 2 The coating liquid used in Example 1 is coated onto a release paper using a floating rod coater so that the coating amount is about 50 g/m' when dry. If a concave rod consisting of a groove with a width of 5 mm and a depth of approximately 200 microns is used in the bar part of the rod knee and jig, a thin tape-like material can be obtained. When this material is cut at intervals of about 10 cm, a highly flexible thin string-like material can be obtained.

In addition, if the same method is diluted to about twice the amount and dried on a release paper in the form of a mist using a spray gun, a highly varied and intertwined small-shaped product can be obtained.

The amount of liquid absorbed by these small objects in an EG-water system (20% or more water) is about 15 times their own weight, and by using them as the contents of the water pillow, the present invention, which has good curing properties even at extremely low temperatures, can be used. You can get a pillow of water.

Example 3 A small-sized article was produced in the same manner as in Example 1 except that the water-swellable polymer in Example 1 was replaced with a crosslinked sodium polyacrylate product (water swelling degree of about 50 times). The amount of water is about 5 times as much, and the water pillow of the present invention is created using the water supply.
It showed excellent kustudionic properties even at extremely low temperatures.

Claims (5)

[Claims] (1) In water pillows whose contents are frozen, the contents are small objects made of water-swellable polymers and polyurethane elastomers that have expanded by absorbing a solution of water-soluble substances and water. Features a water pillow. (2) The small-shaped object is a thin string-like object (
The water pillow described in item 1). (3) The water-swellable polymer has a bond formation of (hydrophobic polymer segment)-(hydrophilic polymer segment)-(hydrophobic polymer segment)
The water pillow described in item 1). (4) The water pillow according to claim (1), wherein the polyurethane elastomer is hydrophilic and water-insoluble. (5) The small object absorbs a solution or dispersion of an organic solvent consisting of a polyurethane elastomer and a water-swellable polymer,
The water pillow according to claim (1), which is formed by coagulating into a thin string shape in water.