JP2002065718A - Cold insulating material and method for manufacturing the cold insulating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cold insulant which may be deformed according to places of use as the material having pliability and is less bulky during storage and transportation. SOLUTION: This cold insulant 10 is formed by sealing a high-polymer water absorptive resin 20 into a gap part 20B formed by laminating a permeable base fabric 30 and a thermoplastic resin film 20 having plural projecting parts 20A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold insulator and a method for manufacturing the cold insulator.

[0002]

2. Description of the Related Art Conventionally, a cooling material such as a cooling pillow in which a coolant containing water, an antifreeze, a gelling agent and the like is wrapped in a resin sheet has been often used. Such a cold insulator is usually used in a state where a coolant is solidified in a freezer.

[0003]

However, the ordinary cold insulator solidifies a large amount of the coolant contained therein, so that the cold insulator itself is hard and lacks flexibility. In addition, since the coolant is sealed almost entirely, it is difficult to bend and deform and use it because it is solidified.
There is also a problem that the cooling surface and the like are limited. Further, before the coolant is solidified, although there is some flexibility, it is not so small that it can be folded, so that there is a problem that a certain amount of space is required for storage and transportation.

[0004] The object of the present invention is to have flexibility and to be able to deform according to the place of use,
An object of the present invention is to provide a cold insulator and a method for manufacturing the cold insulator which are not bulky during transportation.

[0005]

The cold insulator according to the present invention comprises:
It is characterized in that a polymer water-absorbing resin is sealed in a void formed by laminating a water-permeable base fabric and a thermoplastic resin film having a plurality of convex portions. Various woven fabrics, nonwoven fabrics, and the like can be used as the water-permeable base fabric in the present invention, but it is preferable to use a nonwoven fabric in consideration of manufacturing costs and the like.

[0006] The nonwoven fabric is not particularly limited, and is a nonwoven fabric manufactured by various manufacturing methods. For example, a known nonwoven fabric such as a spunbonded nonwoven fabric, a spunlace nonwoven fabric, a hot-air guard nonwoven fabric, a hot embossed guard nonwoven fabric, and a melt blown nonwoven fabric can be used. No. Among these, strength,
From the viewpoint of productivity and the like, a spunbond nonwoven fabric which is a long fiber, a meltblown nonwoven fabric having a special function, and a multilayer nonwoven fabric composed of a plurality of these are exemplified.

As the thermoplastic resin used for the nonwoven fabric, a polyolefin resin is exemplified. Here, as the polyolefin resin, polyethylene, and a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms are preferable. As the copolymer, linear low-density polyethylene (L
LDPE (hereinafter abbreviated as LL), high-pressure LDPE, and the like.

The non-woven fabric made of a thermoplastic resin other than the polyolefin resin includes polyester resins and polyamide resins, preferably having a melting point of 150 ° C. or higher, more preferably a melting point of 150 to 300 ° C. Here, as the polyester resin, polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, homopolyesters such as polynaphthalene terephthalate, and copolyesters obtained by copolymerizing other components with these as a main component unit, and further, Can be mentioned.

As the polyamide resin, nylon 6 is used.
(Polycaprolactamide), nylon 6,6 (polyhexamethylene adipamide), nylon 6,10 (polyhexamethylene sebacamide), nylon 11 (polyundecaneamide), nylon 7 (poly-ω-aminoheptane) Acid), nylon 9 (poly-ω-aminononanoic acid), nylon 12 (polylaurinamide) and the like. Among them, nylon 6, nylon 6,6 are preferably used.

The nonwoven fabric to be used may be a nonwoven fabric composed of one kind of thermoplastic resin alone or a composite fiber nonwoven fabric composed of two or more kinds of thermoplastic resins.
As these composite fiber nonwoven fabrics, a core-sheath composite fiber composed of a resin having a higher melting point than a sheath component resin such as a polyolefin resin as a sheath component, a polyamide resin or a polyester resin as a core component, or a fiber, 50% by mass or more is a polyolefin-based resin, and the remainder is another resin. The core-sheath structure fiber and the side-by-side structure conjugate fiber may be a combination of two different types of polyolefin resins from among polyolefin resins.

Although the fiber diameter of the nonwoven fabric is not particularly limited, it is preferably 1 to 50 μm, for example.
-40 μm is more preferred. Further, the basis weight of the nonwoven fabric is not particularly limited, but is usually 5 to 200.
g / m ^2, preferably 15~150g / m ^2. By setting the basis weight in this range, sufficient water permeability and strength can be secured. In the case of a three-layer laminated nonwoven fabric of spunbonded nonwoven fabric / meltblown nonwoven fabric / spunbonded nonwoven fabric, the basis weight is preferably 7 to 25 g / m ² , and more preferably 12 to 17 g / m ² .

[0012] The water permeability of the nonwoven fabric is JIS A-1
Water permeability determined according to 218 is 1.0 × 10 ^-2 cm
/ S or more, and by setting the water permeability to this value or more, water can quickly permeate the nonwoven fabric and swell the polymer absorbent resin.

The thermoplastic resin constituting the thermoplastic resin film is preferably one having excellent water resistance and mechanical strength at low temperatures. Specifically, it is safe and excellent in hygiene and is suitable for the global environment. Gentle polyolefin resins are preferred. As the polyolefin-based resin, various polyethylenes and polypropylenes can be adopted, but in consideration of the strength of the cold insulator, polyethylene is preferably adopted.

The polymer water-absorbing resin is roughly classified into three types, starch-based, cellulose-based, and synthetic polymer-based, according to the composition. In the present invention, any of these can be used. Here, the starch-based and the cellulose-based include a graft polymerization system and a carboxymethylation system, respectively. On the other hand, examples of the synthetic polymer include polyacrylic acid, polyvinyl alcohol, polyacrylamide, and polyoxyethylene. Among them, it is preferable to use a starch graft polymerization type or a polyacrylic acid type. As the form of the resin, various forms such as a powder form, a fiber form, a film form and the like can be adopted.

The principle of water absorption of such a polymer water-absorbing resin is as follows. That is, when an absorbent resin having a large number of hydrophilic groups comes in contact with water, it begins to dissolve in water and begins to spread, and the osmotic pressure generated due to the ion concentration inside the resin being higher than that of external water causes water to enter the resin. Is absorbed. Subsequently, the negative ions of the hydrophilic groups repel each other, further promoting the spread. Here, since the water-absorbent resin has a three-dimensional cross-linking structure, if it spreads to some extent, it will not spread any more, it will stop in a state where the net is spread, and water will flow into each of the polymer stitches. It is trapped and produces water absorption.

Further, the number of voids is not particularly limited as long as a plurality of voids are formed, but it is preferable to form as many voids as possible in order to enhance the cooling effect. In addition, the size, shape, and the like of the gap can be arbitrarily set according to the use and the like.

In using the cooling material of the present invention,
First, by immersing the cold insulator in water, the water that has passed through the water-permeable base fabric is absorbed by the water-absorbent resin in the voids, causing the resin to swell. Subsequently, the water absorbed in the water-absorbent resin is frozen by cooling the cold insulator immersed in the water in a freezer or the like. This will be used by hitting the part to be cooled. In use, the portion other than the void portion may be cut and used in an appropriate size, or may be used after being deformed according to the form of the portion to be cooled.

According to the present invention, there is provided a cold insulating material in which a high-molecular-weight water-absorbing resin is sealed in a void formed by laminating a water-permeable base fabric and a thermoplastic resin film having a plurality of convex portions. . Therefore, since it is more flexible than a conventional cold insulator in which a coolant is sealed over the entire surface, it can be easily rolled into a roll shape before use. In addition, since the water-permeable base fabric and the thermoplastic resin film can be easily folded from a portion where the thermoplastic resin film is in close contact (a portion having no void portion), storage,
It is not bulky during transportation.

Further, even when used, the portion where no void portion is formed can be easily bent and the flexibility of the heat insulating material as a whole is maintained. Can be used. That is, instead of planar cooling from one surface, by deforming and wrapping the object to be cooled, it is possible to perform efficient cooling and cooling from the entire periphery.

In the above, the encapsulation rate of the polymer water-absorbing resin is not particularly limited, and can be appropriately selected in consideration of the swelling rate of the polymer water-absorbing resin, the volume of the voids, and the like. Specifically, it is preferably at least 1%, more preferably at least 5%, based on the volume of the gap. Here, the encapsulation rate is 1
%, A sufficient cooling effect may not be obtained. In addition, the encapsulation rate in the present invention refers to the ratio of the filling amount (g) of the polymer water-absorbing resin to the volume (cm ³ ) of the void.

In the method for producing a refrigerating agent according to the present invention, the thermoplastic resin film is heated and wound around a forming drum provided with a plurality of concave portions on the surface to form a void portion in the concave portion. A high molecular absorptive resin is put into the unit using a sealing device, and subsequently, the thermoplastic resin film and the water-permeable base fabric are heat-welded on the forming drum.

Here, when forming the void portion in the thermoplastic resin film, for example, a method of vacuum suction from inside a concave portion formed in the forming drum can be adopted. When enclosing the polymer water-absorbent resin, for example, a predetermined amount of the polymer water-absorbent resin is filled in the gap formed in the film by using an encapsulation device such as a hopper provided with a measuring device at the tip. May be enclosed.

Further, the temperature for heating the thermoplastic resin film may be appropriately set according to the material of the film to be used. In the case of a polyolefin resin,
It will be heated to about 60 to 155 ° C. The temperature at which the thermoplastic resin film and the water-permeable base fabric are heat-welded may be appropriately set according to the material of the resin sheet and the base fabric, but a polyolefin resin and a nonwoven fabric made of LLDPE are used. In this case, heat welding may be performed at 90 to 180 ° C.

According to the present invention, all the steps of forming the void, enclosing the polymer-absorbent resin, and thermally welding the water-permeable base fabric and the thermoplastic resin film are performed on the forming drum. Manufacturing equipment can be simplified, and an increase in manufacturing cost can be suppressed.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. [1] Cooling material FIGS. 1 to 3 show a cooling material 1 according to an embodiment of the present invention.
0 is shown. The cold insulator 1 is made of PE which is a water-permeable base cloth.
A nonwoven fabric 30 made of T / LLDPE, a polyethylene film (hereinafter, referred to as a PE film) 20 which is a thermoplastic resin film having a plurality of protrusions 20A thermally welded to the nonwoven fabric, and the nonwoven fabric 30 and the PE Void 20B formed by laminating films 20
And a polymer-absorbent resin 20C sealed in the box.

The basis weight of the nonwoven fabric 30 is 45 g /
m^TwoAnd its hydraulic conductivity is 1.0 × 10^-2cm / s
(Values determined in accordance with JIS A-1218)
Have been. The amount of the polymer absorbent resin 20C to be filled is:
1 g (about 6% by encapsulation rate). That is, the convex part
The specific size of 20A is, as shown in FIG.
Modal A = 50 mm, dimension B = 10 mm. Dimension C = 30mm
And its volume is 15 cm ^ThreeIt is. Therefore,
The encapsulation rate is 100 × (1/15) = 6.0%.

[2] Cooling Material Manufacturing Apparatus and Manufacturing Method FIGS. 4 to 6 show a drum forming machine 40 which is a manufacturing apparatus used in the cold insulating material manufacturing method of the present invention. The drum molding machine 40 is a device that forms the convex portions 20A on the PE film 20, then encloses the polymer absorbent resin 20C in the convex portions 20A, and subsequently heat-welds the PE film 20 and the nonwoven fabric 30. .

The drum forming machine 40 includes an infrared heater 43 for heating the PE film 20 fed from the feeding device 41 through the guide rolls 42A, 42B and 43B, and a projection 20A around which the PE film 20 is wound. Forming drum 44 and a hopper 49 as an enclosing device for enclosing the polymer absorbent resin 20C in the formed convex portion 20A.
And guide rolls 46A, 46B from another feeding device 45,
A heating roll 47 for heat-welding the nonwoven fabric 30 fed through 46C to the PE film 20, a conveying means 48 for sending out the cold insulating material 10 manufactured as described above, and an operation panel 55 for integrally controlling these components. Have.

The forming drum 44 has a plurality of concave portions 44A formed along the axial direction and the circumferential direction. Recess 44
As shown in FIG. 4, A is a bottom member 5 as an easily releasable material made of a silicone molded product at a predetermined depth position of a through hole 50 formed in a metal outer peripheral portion of the forming drum 44.
1 and is held in the through hole 50 by the elastic force of the bottom member 51. further,
As shown in FIG. 5, a plurality of notches 51 </ b> A are formed on the periphery of the bottom member 51, and the inside of the forming drum 44 and the recesses 44 </ b> A communicate with each other by the respective notches 51 </ b> A.
Each of the concave portions 44A can be vacuum-sucked from inside the forming drum 44.

The outer peripheral portion of the forming drum 44 is heated to 40 to 100 ° C. by a built-in heater (not shown). That is, the PE film 20 is heated to 60 to 155 ° C. from both sides by the heater (not shown) and the above-described infrared heater 43 disposed outside. Instead of sucking the concave portion from the inside of the drum, the convex portion may be formed on the PE film by pushing the PE film into the concave portion by a pressing element fitted into the concave portion.

The hopper 49, which is an enclosing device, is formed in a conical shape whose diameter decreases as it goes downward, has an opening at the upper part for charging the polymer absorbent resin 20C, and discharges the resin at the lower end. It has an outlet to be used.
A measuring device 49A is attached to a discharge port for discharging the polymer absorbent resin 20C, and a predetermined amount of the absorbent resin 20C is sealed in a convex portion 20A formed on the PE film 20. The number of the hoppers 49 provided in the forming drum 44 is equal to the number of the concave portions 44A arranged in the axial direction of the forming drum 44 (the direction perpendicular to the plane of FIG. 3).

The heating roll 47 has a surface of 80 to 250 ° C.
The nonwoven fabric 30 is configured to be thermally welded to each other while pressing the nonwoven fabric 30 against the PE film 20 at a welding temperature in this range. The transporting means 48 includes a pair of conveyors 48A and 48B for guiding the cooling material 10 peeled off from the forming drum 44 directly below, and a receiving table 48C for sending the guided cooling material 10 in the horizontal direction. Here, one of the conveyors 48B is of a retractable type, and the tip of the cooling material 10 sent out at the start of production is connected to each conveyor 4B.
It can be easily introduced between 8A and 48B.

In this embodiment, the cold insulator 10 is manufactured as follows. First, P rolled into a roll
E film 20 and nonwoven fabric 30
1, 45, PE film 20 and non-woven fabric 30
Is guided to the forming drum 44 and wound. Further, the polymer absorbent resin 20C is put into the hopper 49.

The PE film 20 wound around the forming drum 44 is heated to 60 to 155 ° C. by the infrared heater 43 and the outer peripheral surface of the forming drum 44 itself at 40 to 100 ° C., and is softened to a formable state. At the same time, vacuum suction is performed from the inside of the forming drum 44 to form the projection 20A on the PE film 20. Subsequently, a predetermined amount of the polymer absorbent resin 20C previously charged into the hopper 49 is sealed in the projection 20A by a measuring device 49A provided at the tip of the hopper 49.

Thereafter, the PE film 20 and the nonwoven fabric 30 laminated thereon are heat-welded by a heating roll 47 heated to 80 to 155 ° C. Then, the PE film 20 and the nonwoven fabric 30 integrated by heat welding are separated from the forming drum 44 to obtain the cold insulator 10.

[3] Method of using cold insulator The cold insulator 10 thus obtained is used as follows. First, the cold insulator 10
Is cut to a suitable size. Cooled insulation material 10
Is immersed in water, the water that has passed through the nonwoven fabric 30, which is a water-permeable base fabric, is absorbed by the polymer absorbent resin 20C sealed in the void 20B, and the absorbent resin 20C swells. The cold insulator 10 soaked in water is put into a freezer or the like, and the water absorbed by the absorbent resin 20C is frozen. This is taken out, attached to the use site, and cooled and kept cool.

According to the above-described embodiment, the following effects can be obtained. (1) A cold insulator 10 in which a polymer water-absorbent resin 20C is sealed in a void 20B formed by laminating a PE film 20 having a plurality of convex portions 20A and a nonwoven fabric 30.
Therefore, since it is more flexible than a conventional cold insulator in which a coolant is sealed over the entire surface, it can be easily rolled into a roll shape before use. In addition, since the water-permeable base fabric and the thermoplastic resin film can be easily folded from a portion where the thermoplastic resin film is in close contact (a portion having no void portion 20B), storage,
It is not bulky during transportation.

Further, even in use, since the portion where the void portion 20B is not formed can be easily bent and the cooling material 10 as a whole is kept flexible, it can be deformed according to the portion to be used. Can be used.
That is, instead of planar cooling from one surface, by deforming and wrapping the object to be cooled, it is possible to perform efficient cooling and cooling from the entire periphery.

(2) Formation of void 20B (projection 20A)
Encapsulation of polymer absorbent resin 20C, and nonwoven fabric 30 and P
All steps of heat welding with the E film 20 are performed by the forming drum 4
4, the manufacturing equipment can be simplified, and an increase in cost can be suppressed. (3) The heating means of the drum forming machine 40 is an infrared heater 43
Further, since the PE film 20 is heated from both sides by the forming drum 44, the PE film 20 can be brought to an appropriate forming temperature in a short time, and productivity can be improved. (4) Since the bottom surface of the concave portion 44A of the forming drum 44 is formed by the bottom member 51 which is a silicone molded product, the removability of the convex portion 20A in the concave portion 44A can be further improved, and the cold insulator 10 Can be formed more reliably.

It should be noted that the present invention is not limited to the above-described embodiment, but includes modifications and improvements as long as the object of the present invention can be achieved. For example, in the above embodiment, PET / LLDPE is used as the water-permeable base fabric.
Nonwoven fabric 30 was used, but is not limited to this.
A nonwoven fabric made of P may be used, or a woven fabric may be used. In short, any base cloth having water permeability may be used. In addition, although the PE film 20 is used as the thermoplastic resin film, the present invention is not limited to this, and any thermoplastic resin film can be used.

In the above embodiment, the basis weight of the nonwoven fabric 30 is 45 g / m ² , but is not limited thereto.
Any basis weight can be adopted. In addition, nonwoven fabric 3
A water permeability coefficient of 1.0 × 10 ⁻² cm / s or more (JIS
A-1218).
The value is not limited to this, and the value is arbitrary as long as the water can penetrate into the voids and be absorbed by the polymer absorbent resin when immersed in water. Further, the amount of the polymer-absorbent resin 20C to be filled was 1 g, but is not limited thereto, and may be appropriately set according to the swelling ratio of the absorbent resin, the strength of the thermoplastic resin film used, and the like. it can.

In the above-described embodiment, the bottom member 51 forming the concave portion 44A of the forming drum 44 is a silicone molded product. However, the present invention is not limited to this. In other words, any material can be used as long as it has easy releasability. In addition, the PE film 20 is heated from both sides, but is not limited thereto. For example, the PE film 20 may be heated only by an infrared heater provided on the outer peripheral side of the forming drum, and the PE film can be heated and formed. As long as it can be softened to an appropriate state, the number, arrangement position, heating location, and the like are arbitrary. Further, the heater is not limited to the infrared heater, and another heater generally used may be used.

Further, the PE film 20 has a single-layer structure, but is not limited thereto, and may have a multilayer structure of two or more layers. At this time, a difference in melting point may be provided on both side surfaces of the PE film. In addition, specific structures, shapes, and the like when implementing the present invention may have other structures, shapes, and the like as long as the objects of the present invention can be achieved.

[0044]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. [Example 1] As a thermoplastic resin film, LLDPE was used.
(Thickness: 60 μm) as PET and LLDP as nonwoven fabric
Using a laminated nonwoven fabric of E (Strumity MN050S, manufactured by Idemitsu Unitech Co., Ltd., weight per unit area: 50 g / m ² ) and Sunfresh ST500D (Sanyo Kasei Co., Ltd., water absorption magnification: 400 times) as a polymer water-absorbing resin, The cooling agent 10 was manufactured by the apparatus and the method described in the above embodiment.

[0045]

According to the present invention, a heat insulating material in which a high-molecular water-absorbing resin is sealed in a void formed by laminating a water-permeable base cloth and a thermoplastic resin film having a plurality of convex portions. It is. Therefore, since it is more flexible than a conventional cold insulator in which a coolant is sealed over the entire surface, it can be easily rolled into a roll shape before use. Further, since the water-permeable base fabric and the thermoplastic resin film can be easily folded from a portion where they are in close contact (a portion having no void), they are not bulky during storage and transportation.

Further, even in use, it can be easily bent from a portion where no void portion is formed, and since the cooling material as a whole retains its flexibility, it can be deformed according to the portion to be used. It is possible to do. That is,
By wrapping the object to be cooled instead of planar cooling from one surface, it is possible to perform efficient cooling and cooling from the entire periphery.

[Brief description of the drawings]

FIG. 1 is a plan view showing a cold insulator according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a cold insulator in the embodiment of FIG.

FIG. 3 is a perspective view showing a protrusion in the embodiment of FIG. 1;

FIG. 4 is a schematic configuration diagram showing a manufacturing apparatus used in the method for manufacturing the cold insulator of FIG.

FIG. 5 is an enlarged sectional view of a main part of the manufacturing apparatus of FIG.

FIG. 6 is a plan view showing components of the manufacturing apparatus of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Cold insulating material 20 Polyethylene film as a thermoplastic resin film 20A Convex part 20B Void part 20C Polymer absorbent resin 30 Nonwoven fabric as a water-permeable base cloth 40 Drum molding machine 44 Molding drum 44A Concave part

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) B29K 67:00 B29K 67:00 B29L 7:00 B29L 7:00 F term (reference) 4C099 AA02 CA03 CA07 CA09 CA11 CA19 GA12 HA02 HA06 JA05 LA02 LA07 LA11 4F211 AA03 AA04 AA08 AA24 AC03 AH81 TA01 TC03 TC05 TC14 TC20 TD11 TH02 TH06 TJ23 TJ29 TN12 TN26 TQ10 TW06 TW15 TW16 4L047 AA14 AA21 AA23 AA27 AA07 CB09 CB09 CB09 CB09

Claims (7)

[Claims] 1. A cold insulating material characterized in that a polymer water-absorbing resin is sealed in a void formed by laminating a water-permeable base fabric and a thermoplastic resin film having a plurality of convex portions. 2. The cold insulator according to claim 1, wherein said water-permeable base fabric is a nonwoven fabric. 3. The cold insulator according to claim 2, wherein the basis weight of the nonwoven fabric is 15 to 150 g / m ² . 4. The cold insulator according to claim 2, wherein the nonwoven fabric has a water permeability of 1.0 × 10 ⁻² cm / s or more. 5. The cold insulator according to claim 1, wherein said thermoplastic resin is a polyolefin resin. 6. The heat insulating material according to claim 1, wherein the encapsulation rate of the polymer water-absorbing resin is 1% or more with respect to the volume of the void. Cold insulation. 7. A method for heating a thermoplastic resin sheet,
After winding around a forming drum provided with a plurality of recesses on the surface to form voids in the recesses, a polymer absorbent resin is put into the voids using an encapsulating device, and then the thermoplastic resin film And heat-welding the water-permeable base fabric on the forming drum.