JPS62167333A - Cooling sheet material - Google Patents

Abstract

PURPOSE:A simple sheet material for cooling having improved durability, consisting of a selective permeability sheet material which has water pressure resistance of >= a specific value, does not permeate liquid in at least one direction but has gas permeability. CONSTITUTION:A cooling sheet material consisting of a selective permeability structure, which comprises (A) a continuous fine porous membrane preferably containing a water-repellent resin, more preferably continuous fine porous membrane of synthetic polymer and a fibrous material reinforcing the membrane or (B) a fibrous structure such as cloth, etc., preferably having a structure of density different in the thickness direction, has at least 30mm H2O/cm<2>, preferably >=50mm H2O/cm<2> water pressure resistance and does not permeate liquid in at least one direction but has gas permeability. For example, when a canteen is made of this sheet material and water is put in it, water in the canteen can be cooled by latent heat of evaporation of water.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a cooling sheet material that does not require particular energy, is simple, and has excellent sustainability.

[Prior art]

Conventionally, known cooling products include ice packs filled with ice, water pillows filled with water, and even film bags filled with starch paste.

In addition to these, there are products that apply mechanisms used in ordinary refrigerators and the like.

However, these conventional technologies, such as ice packs, require ice and have a cooling capacity only until the ice melts, and cannot cool a water pillow below the water temperature. , it is necessary to cool it in advance using a refrigerator or the like.

[Purpose of the invention]

In view of the drawbacks of the prior art, the present invention has discovered a new sheet material that can lower the temperature of liquids, especially water, by skillfully utilizing the principles of nature without using any particular energy.

According to the present invention, it is possible to provide a cooling sheet material that is simple, has excellent sustainability, and achieves cooling economically.

[Structure of the invention]

In order to solve this problem, the present invention employs the following means.

1. A cooling device characterized by being constructed of a permselective sheet material having a water pressure resistance of at least 30 nuw H, O/crA and being impermeable to liquids but permeable to gases in at least one direction. sheet material.

2. The cooling sheet material according to claim 1, wherein the permselective sheet material is a continuous microporous membrane.

3. The cooling sheet material according to claim 2, wherein the continuous microporous membrane contains a water-repellent resin.

4. Claim 2, wherein the membrane structure is composed of a synthetic polymer continuous microporous membrane and a fiber material reinforcing it.
Cooling sheet material described in section.

5. The cooling sheet material according to claim 4, wherein the fiber material contains a water-repellent resin.

6. The cooling sheet material according to claim 1, wherein the permselective sheet material is a fibrous structure.

7. The cooling sheet material according to claim 6, wherein the fiber structure is a fabric.

8. The cooling sheet material according to claim 6, wherein the fiber structure has a density structure that differs in the thickness direction.

9. The cooling sheet material according to claim 6, wherein the fiber structure contains a water-repellent resin.

The cooling sheet material of the present invention exhibits a cooling function that gradually lowers the temperature of the liquid, such as water, when this material is placed at the interface where liquid, such as water, and the atmosphere, ie, air, come into contact. , such a cooling function requires that the cooling sheet material is at least 301H YuO/c11!
, preferably has a water pressure resistance of 50 mm I(zo/crA or more, particularly preferably 100 mm H20/cIa or more, most preferably 300 mm H2O/crA or more, and is liquid impermeable in at least one direction but gas permeable This is achieved by having a structure that is .

Here, "one direction" refers to the direction in which the liquid permeates, and "liquid impermeability" refers to the degree to which the liquid does not seep out, and it is sufficient that the surface is not wetted by the liquid.

Also, gas permeability means moisture permeability of 3000g/g・2
4hr or more, preferably 5000g/rd・24h
r or more, more preferably 7000g/rd・24h
r or more.

Here, the permselective sheet material in the present invention includes a membrane having continuous micropores and a fibrous structure.

The continuous microporous membrane is preferably treated with a water repellent treatment as described below, and is more preferably composed of a synthetic polymer continuous microporous membrane and a fibrous material reinforcing it, which is the object of the present invention. It is possible to increase the cooling function and improve water leakage resistance.

The pores constituting the continuous microporous membrane have an average pore diameter of about 0.01 to
It has a continuous microporous structure in the range of 100μ, preferably about 0.1-50μ, more preferably 0.5-3μ.

If the average pore diameter of the pores is larger than 100μ, it will not exhibit water leakage resistance, which is undesirable as it will greatly limit its use, and if it is smaller than 0.01μ, it will not exhibit vapor permeability and its cooling function will not be exhibited. I don't like it because it disappears.

The membrane structure of the synthetic polymer microporous membrane may be a structure in which there is no difference in pore density, for example, pores having the above-mentioned average pore diameter are uniformly distributed, but preferably in the membrane thickness direction. It is preferable to have a pore density difference (dense and coarse) structure in which the pore diameter and/or number of pores are changed.

However, the pores in the synthetic polymer membrane are continuous pores, that is, pores that penetrate from the front surface to the back surface of the membrane, and more preferably, the pores are in communication with each other within the membrane.

The synthetic polymer constituting the microporous membrane of the present invention is not particularly limited as long as it can form a microporous structure.

Specific examples include polyurethane polymers, fluorine polymers such as polytetrafluoroethylene, and polyolefin polymers such as polyethylene, polypropylene, and polyethylene polypropylene copolymers.
Preferably it is a polyurethane polymer.

Methods for manufacturing microporous membranes made of these synthetic polymers include the so-called dry coagulation method, in which a solvent solution of the synthetic polymer is cast or applied onto a substrate, and the solvent is evaporated and removed; There is a so-called wet coagulation method in which the substrate is immersed in a coagulation bath to coagulate and solidify the polymer, washed with water, and dried, and in some cases, a pore-forming agent may be mixed into the polymer solution.

As a dry coagulation method, for example, Japanese Patent Application Laid-Open No. 60-19039
No. 3 can be mentioned, that is, by reacting polyethylene adipate, polybutylene adipate, etc. whose terminal group is a hydroxyl group and whose molecular weight is 300 to 4000 with an organic diisocyanate such as 4.4'-diphenylmethanecymedianate. The resulting polyurethane resin is mixed with an organic solvent that has limited mutual solubility with water, such as methyl ethyl ketone or methyl-n, which has a boiling point of 120 degrees or less at normal pressure.
- By coating or impregnating the substrate with an emulsion prepared by emulsifying and dispersing an appropriate amount of water in a polyurethane solution dissolved and/or dispersed in butyl ketone, etc., and then drying to remove the organic solvent and water. Obtain a microporous membrane.

In addition, the wet coagulation method is performed, for example, as described in Japanese Patent Publication No. 60-47955, by applying a polar organic solvent solution containing mainly a polyurethane polymer to a substrate, and then immersing the substrate in a coagulating solution.

Examples of the polyurethane polymer include polyester-based or polyether-based polyurethane polymers, and generally any polymer can be used as long as it has the function of forming a microporous membrane by a wet coagulation method. be able to.

However, when using these polymers to form extremely small pores on the surface of the coated film, it is also necessary to form pores inside the film that have an inner diameter larger than the diameter of the pores on the surface, so polyurethane As a coating solution mainly composed of, for example, a solution containing a dimethylformamide solution containing polyurethane, a fluorine-based water repellent, a polyisocyanate, and a nonionic surfactant is used.

Alternatively, as disclosed in JP-A-59-125974, an organic solvent solution containing a single or mixed polymer such as polyurethane, polyamide, polyvinyl chloride, polyvinylidene chloride, etc. is applied onto a substrate, and then a dry process is performed. It can also be obtained by applying a solution of the above polymer containing fine metal particles onto this layer after coagulation or wet coagulation and allowing it to harden.

As a water treatment method, it is possible to apply or impregnate the fiber structure with a commonly used silicone-based or fluorine-based water repellent, or to adopt the method described in Japanese Patent Publication No. 60-47955, which describes the method for manufacturing the membrane. can.

Such hydrodynamic processing improves the water pressure resistance of the permselective sheet base material, and allows the use of a sheet base material with a coarse density and pore diameter, which increases moisture permeability and improves the cooling effect accordingly.

In other words, when the sheet base material is a membrane, the average pore diameter is 1.
Even if the water pressure exceeds 00μ, the effects of the present invention can be achieved as long as the water pressure resistance is satisfied.

Furthermore, in the present invention, the mechanical strength of the microporous membrane is improved by using, for example, a knitted fabric, a nonwoven fabric, a fleece, or a cotton-like material as a fiber material reinforcing the continuous microporous synthetic polymer membrane. Handlability can be improved and various performances can be imparted.

For example, when using a water-absorbing fabric as a reinforcing base material, the fabric of the water-absorbing layer exhibits a cooling function simply by absorbing water, so it can be used as a poultice, a wetsuit, etc. with a cooling function. I can do it.

In particular, the microporous membrane of the present invention has a moisture permeability of 5000
g/rd ・24hr or more, water pressure resistance is 300RH2
0/c++1 original 20/c+, in addition to excellent cooling function,
Since it has excellent water leakage resistance, it is useful for applications that particularly require water leakage resistance, such as water pillows and water bottles.

In addition, when the permselective sheet material in the present invention is a fibrous structure, fabric can be used, nonwoven fabric,
A knitted fabric is used.

In addition, ordinary water-repellent fabrics and DP-structured fiber fabrics are also used, and are influenced by the fiber density and water repellency of the fabric, as well as the fineness (usually 0.01 to 10 d), but the resistance is at least 301IllIH20/alf. It is not particularly limited as long as it has water pressure and is liquid impermeable but gas permeable.

In addition, if the fabric leaks water, it may be treated with water repellent treatment or
Practicality can be imparted by using a fabric with a P structure.

As the water processing method, the above-mentioned method can be used.

Effects similar to those described above can be expected by such a water-repellent treatment, and the effects of the present invention can be achieved even if the water-repellent treated fabric has an even smaller basis weight.

In addition, the DP structure is, for example,
As disclosed in the above issue, in a single knitted fabric composed of a plurality of yarns with different single yarn finenesses, a single yarn yarn with a small single yarn fineness,
Yarns having a relatively large single yarn fineness are arranged in close contact with each other.

In this structure, when a yarn with a smaller single filament fineness is used on the inside, the capillary tubes in the inner layer are thinner than those in the outer layer, and when comparing the suction force between the inner layer and the outer layer, the inner layer is larger than the outer layer. Therefore, a force that tries to move the liquid from the outer layer to the inner layer acts on the adjacent surface between the inner layer and the outer layer.

Therefore, the liquid will be retained in the inner layer, and the outer layer will not become wet with water.

The knitting structure of the knitted fabric may be jersey, front pique, regular pique, soccer, etc., or any modified structure thereof, and is not limited to the knitting structure as long as it is a single knitted fabric.

Further, the yarn may be a long fiber yarn or a short fiber yarn, and the material composition is not limited as long as it is a synthetic fiber such as polyester, poamide, polyacrylonitrile, etc.

Alternatively, in a knitted fabric made of synthetic fibers, the degree of convergence of the yarns constituting the front side of the knitted fabric and the yarns constituting the back side are different, and the yarns constituting the front side have a higher degree of convergence. A DP structure can also be obtained by increasing the height of the DP structure.

〔Effect of the invention〕

As described above, the cooling sheet material of the present invention is a selectively permeable sheet material that has a water pressure resistance of at least 30 mm H 0 and is liquid impermeable in at least one direction but gas permeable. Because of its structure, it has excellent water resistance or water leakage resistance, and if a water-containing container is manufactured using this sheet material to contain water, or if a water-containing substance is covered with this sheet material, water can be removed. The latent heat of vaporization can cool the water in a water-containing container or lower the temperature of a water-containing substance.

Therefore, since the sheet material of the present invention has a cooling function, it is extremely useful for a wide variety of applications, such as water bottles, cooling bottled beer and juice, agricultural sheets that prevent condensation and stuffiness, tents, and pass mats. .

In addition, in the present invention, the water pressure resistance is JIS L-109.
2. Moisture permeability is JIS Z-0208 and water repellency is JI
Measured by the method of SL-1092.

The barrel water level can be used as an index to indicate the degree of water repellency, and in the present invention, barrels with a water repellency level of 100 are normally used.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

〔Example〕

Polyester filament plain weave with 1000% water pressure resistance
O/crA, moisture permeability 6000 g/g ・24h
A sea urchin polyurethane polymer was coated on only one side so as to give r, and wet coagulation was performed.

A water bottle with a reservoir volume of 10,100 O was produced using this fabric.

On the other hand, as a comparison product, a volume of 1゜00mj made of aluminum
I prepared a t water bottle.

800 mj+ of water was poured into each bottle, and a hole was made in the lid of the water bottle and a copper-constantan thermocouple was inserted to read the temperature change of the water.

These containers were placed in a room adjusted to a temperature of 35° C. and a relative humidity of 40%, and it was observed how the water temperature changed.

The water temperature in the water bottle made of a fabric coated with a polyurethane polymer reached about 29°C after about 2 hours, and the temperature was maintained until 8 hours after the measurement was continued (measurement was stopped at 8 hours).

On the other hand, the water temperature in the aluminum water bottle was approximately 35° C., which is similar to room temperature, throughout the 8-hour measurement period.

Claims (1)

[Scope of Claims] 1. It has a water pressure resistance of at least 30 mmH_2O/cm^2 and is made of a permselective sheet material that is impermeable to liquids but permeable to gases in at least one direction. A cooling sheet material featuring: 2. The cooling sheet material according to claim 1, wherein the permselective sheet material is a continuous microporous membrane. 3. The cooling sheet material according to claim 2, wherein the continuous microporous membrane contains a water-repellent resin. 4. Claim 2, wherein the membrane structure is composed of a synthetic polymer continuous microporous membrane and a fiber material reinforcing it.
Cooling sheet material described in section. 5. The cooling sheet material according to claim 4, wherein the fiber material contains a water-repellent resin. 6. The cooling sheet material according to claim 1, wherein the permselective sheet material is a fibrous structure. 7. The cooling sheet material according to claim 6, wherein the fiber structure is a fabric. 8. The cooling sheet material according to claim 6, wherein the fibrous structure has a coarse and dense structure that differs in the thickness direction. 9. The cooling sheet material according to claim 6, wherein the fiber structure contains a water-repellent resin.