JPH065387Y2 - Cooling tool - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] (1) The present invention relates to a cold insulating tool, more specifically, a water absorbent material in which a superabsorbent polymer for holding a refrigerant is fixed to a water absorbent substrate in a bag. Concerning the stored cool equipment.

[Conventional technology]

Conventionally, focusing on the characteristics of superabsorbent polymer, by keeping the refrigerant in the polymer, there is a cooling agent that can provide the durability of the cold insulation effect and the prevention of exudation of the refrigerant to the outside, for example, JP-A-62-62. -267386 and JP-A-62-240377. In addition, since such a cooling agent scatters or flows out, and stickiness of adhesiveness occurs during water retention and thawing, it improves the retention and handleability, and is therefore put into practical use as a cooling tool stored in a bag. .

[Problems to be solved by the device]

Cooling tools are generally used by supplying water into a bag, allowing the powdered polymer to hold water, and then freezing it.As water absorbing means, there are a valve type that supplies water into a sealed bag through a check valve, It is roughly classified into two structures of a dip type in which water is introduced through a large number of fine holes or slits provided in the bag by immersion.

In the case of the valve type, not only will the cost be increased by the amount of the valve, but it is necessary to supply water individually.
There is a drawback in that a plurality of them cannot be supplied at one time. On the other hand, in the dip type, a plurality of them can be supplied at one time, but there is no large hole to prevent the polymer from falling off or leaking before and after water supply, so it takes time to supply water. It has a defect that the polymer is agglomerated and the water absorption becomes non-uniform.

It is an object of the present invention to provide a dip-type cold-retaining tool capable of supplying water in a shorter time than conventional ones.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the cold insulator of the present invention is formed into a plate-like body in which a water-absorbent polymer is uniformly dispersed and fixed in a fibrous substrate and which has a first surface and a second surface facing the first surface. A water-absorbing material, and a second surface that accommodates the water-absorbing material and that contacts the first surface and the second surface
It is premised on a cold insulating tool consisting of a flat water-permeable bag having a surface.

This invention is based on the above premise in which the first fibrous substrate
And a water diffusion layer is integrally formed on at least one of the second surface, the bag is made of a nonwoven fabric, and the first bag
An impermeable plastic sheet having a size that covers at least the first surface of the water absorbent material that contacts the inner surface is integrally joined to the inner surface of the surface.

〔Example〕

As shown in FIG. 1, the cold-insulating tool according to the present invention is a water-absorbing material 1 formed in a plate-like body having opposite surfaces.
And a flat bag 2 having both surfaces facing each other for accommodating the water absorbent material 1.

The water absorbent material 1 has a structure in which a water absorbent polymer is fixed to a water absorbent substrate. As such a water-absorbing material 1, there is a sheet made by sandwiching a water-absorbing polymer with a tissue or the like, but the use of a material in which the water-absorbing polymer is uniformly dispersed and fixed in a fibrous base material makes the water absorption uniform. preferable.

Here, being fixed in the fibrous substrate means that the water-absorbing polymer and the constituent fibers are physically bound to each other, preferably in a state in which the substantially spherical water-absorbing polymer encloses each or a plurality of the constituent fibers of the substrate. It refers to the form that exists. Further, the term “uniformly dispersed” does not mean that the basic unit volume or the amount of polymer attached per unit area is constant at any position, and it is a dot-shaped or stripe-shaped regular pattern in the substrate. It means that the polymer is fixed in a uniformly dispersed state as the whole substrate, including those in which the polymer is fixed.

The water-absorbent polymer has the ability to absorb several tens to several hundreds times its own weight of water, and for example, starch-based, polyacrylate-based, polyvinyl alcohol-based, polyester-based, etc. have been conventionally put to practical use. However, powders can be used.

As the fibrous substrate to which the super absorbent polymer is applied, a card or an air-laid web, a tissue paper,
Nonwoven fabric or the like can be used. It is preferable to use hydrophilic fibers such as pulp fibers and rayon fibers, hydrophobic fibers such as polyester and polypropylene, or a mixture or a composite of these fibers loosely molded or stabilized by heat setting.

In order to disperse and fix the superabsorbent polymer on the fibrous substrate, specifically, an aqueous monomer solution mainly containing an alkali metal salt or an ammonium salt of acrylic acid or a mixture of acrylic acid / methacrylic acid is applied to the fibrous substrate. After the application, polymerization is performed under the action of a water-soluble radical polymerization initiator. The aqueous monomer solution can be impregnated into the fibrous substrate by spraying, coating with a coater or the like.

The permeation / diffusion of the monomer aqueous solution into the fibrous substrate depends on the surface tension of the monomer aqueous solution, the basis weight / density of the fibrous substrate, the contact angle of the constituent fibers to the aqueous solution, etc. The distribution / adhesion state of the produced polymer in the fibrous substrate is determined. The elastic compression recovery rate of the fibrous substrate is also an important factor.

To attach the water-soluble monomer in a uniformly dispersed state,
It is preferable to use a fibrous substrate having a basis weight of 15 to 15 g / m ² and a compression recovery rate of at least 30%.

The substrate containing at least partially hydrophobic fibers having a contact angle with water in the range of 70 to 110 ° improved the compression elastic recovery rate, and the aqueous monomer solution and thus the polymer adhered spherically and were uniformly dispersed throughout the substrate. Fixed in the state.

Further, when the heat-fusible fibers are mixed and heat set, a fibrous substrate having an improved compression elastic recovery rate and excellent strength and shape retention is formed. Specifically, a specific volume (bulk) of 1.5c formed by heat-setting a loosely formed web by mixing heat-fusible fibers of less than 45% polyester fiber
Fibrous substrates up to c / g can be used.

As another specific example of dispersing and fixing the water-absorbing polymer to the fibrous substrate, the monomer is polymerized after dispersing and mixing the fiber in an aqueous solution, or the polymerized mixture is crushed or defibrated into a sheet shape, Further, a method of heat-sealing by heating may be mentioned.

In addition, it is preferable to add a water diffusion layer 3 made of tissue paper, crushed pulp or the like by compression lamination on at least one of the upper and lower sides of the water absorbent material 1 produced in the above specific example. It was found that the liquid was evenly carried to the dispersed and fixed polymers, and the water absorption amount, and thus the cold insulating ability as a cold insulating material, was improved.

The bag 2 containing the water-absorbent material 1 has the outer peripheral edges 5 of the material sheets constituting the upper and lower surfaces closed by heat sealing.

The material sheet of the bag 2 shown in FIG. 1 has water-permeable surfaces 4 on the upper and lower sides. When a cold insulating tool using this bag 2 is immersed in a refrigerant liquid such as water, the water rapidly enters the bag 2. It flows in and is absorbed by the water absorbent material 1. Since the water-absorbent polymer that constitutes the water-absorbent material 1 is fixed to the fibrous substrate, it does not flow out of the bag 2 before and after water absorption, and uniformly absorbs the liquid. The cold insulating tool is then transferred into a cooling device such as a freezer and cooled, and then used as a cold insulating material. As the material constituting the water-permeable surface, those having not only water permeability but also appropriate strength are preferable, and a highly water-permeable open-pore film having a water pressure resistance of 200 to 300 mmH ₂ O or less, a nonwoven fabric, or a laminate thereof is used. However, the use of non-woven fabric is preferred. As the non-woven fabric, spun lace, spun bond, melt bond, dry non-woven fabric and the like can be used.

Further, when the non-woven fabric is treated with a surface active agent, the water permeability under the action of low water pressure is remarkably improved. Non-woven fabrics with high water permeability also have high water-retaining properties, and when a plurality of cold insulation tools using bags 2 made of such non-woven fabrics are stacked and placed in a cooling device, the bags stick together when the residual water in the non-woven fabric is solidified. As a result, it becomes difficult to separate the individual cold insulators, and if it is attempted to separate them, the bag 2 will be damaged and the water absorbent material 1 will be exposed. For this reason, in such a cold-retaining tool, it takes time to dry the residual water in the nonwoven fabric before cooling, but in order to save this time, as shown in FIG. It is preferable to form the water-impermeable surface 6 having a small water-holding property. The other surface is configured as a water-permeable surface 4, and the outer periphery 5 is heat-sealed. At the time of cooling, even if a plurality of cold-retaining tools are stacked so that the water-permeable surface 4 and the water-impermeable surface 6 come into contact with each other, the bags 2 do not stick to each other, and the labor of drying the nonwoven fabric can be saved.

Further, as shown in FIG. 3 and FIG. 4, the bag 2 has an area that covers at least one of the upper and lower surfaces of the water absorbent material 1 and an area extending from this area to the opposite side on the impermeable surface 6, and The other area is made to be the water-permeable surface 4, or, as shown in FIG. 5, the central area that covers at least one of the upper and lower sides of the water absorbent material 1 is made the water-impermeable surface 6, and the other area is made water-permeable. It may be configured on the surface 4. This impermeable surface 6 is
When the entire surface continuous with this surface 6 is made of a non-woven fabric, this surface 6 may be subjected to an impermeable treatment with an appropriate waterproofing agent or the like, but an impermeable sheet 6a such as a plastic film is provided on the inner surface.
It is preferable to join them together.

Example 1 A cold insulating tool was obtained by enclosing a water absorbing material having a water retention capacity specification of 500 ml in a bag whose upper and lower surfaces were made of polyester spunbonded nonwoven fabric. As the water absorbing material, a sheet-like water absorbing material obtained by coating a nonwoven fabric web made of polyester fibers with an acrylic acid-based monomer and then polymerizing the sheet-like water absorbing material and crushed pulp layers were compression-laminated and integrated. This water absorbent material,
Table 1 shows the results of measuring the water absorption rate by immersing in (1) vertically and submerging in water, (2) horizontally (horizontal) and floating on water, and measuring the water absorption rate. The weight increase of the water absorbing material is shown as the water absorption.

Example 2 An inner polyethylene film having the same width as that of the polyester spunbond nonwoven fabric was laminated on the central region to form one side, and the outer periphery was heat-sealed together with the polyethylene film forming the other side to obtain a water absorption capacity of 500 ml. The water absorbing material was closed inside to obtain a cold insulation tool. The water absorbing material is the same as that in the first embodiment. The non-woven fabric and the interior film are not joined in the bag, the water absorbing material is placed between the interior film and the other surface film, and the cold insulating tool is immersed in water by two methods as in Example 1 to absorb water respectively. The speed was measured and the results are shown in Table 1.

Example 3 The cold insulating tool of Example 2 obtained by treating a nonwoven fabric with a surface active agent was immersed in water, and the measurement results of the water absorption rate are shown in Table 1.

Comparative Example 1 Water absorption speed of trade name "Chiltin" (manufactured by Sanyo Engineering Co., Ltd.) in which a powdery water-absorbent polymer with a water absorption capacity of 500 ml is enclosed in a bag made of a laminated material of a film having micropores and a nonwoven fabric. Was measured and the results are shown in Table 1.

[Advantages of the Invention] According to the cold insulating tool of the present invention having the above configuration,
The water-absorbing polymer does not drop off or leak before and after water absorption, and water can be supplied in a short time, and moreover, the water-absorbing polymer over the entire area of the water-absorbing material can uniformly and rapidly absorb water. Therefore, work such as water supply and freezing can be performed with high efficiency, and an excellent cold-retaining effect can be achieved.

In addition, since the surface area of the bag in which the water-impermeable plastic sheet is located does not retain or retain water, when a plurality of cold-retaining tools are stacked and frozen in the freezer, the surface area retains or retains water. By coagulating with water, the bags of the cold insulation tools do not stick to each other and it becomes difficult to separate the cold insulation tools. Further, since the plastic sheet is located on the inner surface of the bag and the sheet does not come into direct contact with the object to be kept cold, it is not necessary to be particularly nervous about the selection of the sheet even when the cold-retention tool is for food.

[Brief description of drawings]

FIG. 1 is a sectional view of a cold insulating tool according to an embodiment of the present invention. FIG. 2 is a sectional view of a cold insulating tool according to another embodiment. FIG. 3 is a plan view of a cold insulating tool according to yet another embodiment. FIG. 4 is a sectional view taken along line III-III in FIG. FIG. 5 is a plan view of a cold insulating tool according to still another embodiment. 1 ... Water absorbing material, 2 ... Bag, 3 ... Water diffusion layer 4 ... Water-permeable surface, 6 ... Water-impermeable surface 6a ... Water-impermeable plastic sheet

Claims (1)

[Scope of utility model registration request] 1. A water-absorbent polymer formed by uniformly dispersing and fixing a water-absorbent polymer in a fibrous substrate and having a plate-like body having a first surface and a second surface opposite to the first surface, and the water-absorbing material. A cold insulation tool that is housed and comprises a flat water-permeable bag having a first surface that contacts the first surface and a second surface that contacts the second surface, wherein the first and second fibrous substrates are provided. A water diffusion layer is integrally formed on at least one of the surfaces, the bag is made of non-woven fabric, and the inner surface of the first surface of the bag covers at least the first surface of the water-absorbing material that is in contact with the inner surface. The cold-insulating tool according to claim 1, wherein the water-impermeable water-permeable plastic sheet is integrally joined.