JP2003089975A - Dew condensation preventing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dew condensation preventing material capable of being produced in a simple processing, excellent in cost and dew condensation preventing property, suitable for farm materials, construction materials or the like. SOLUTION: This dew condensation preventing material obtained by adhering highly hygroscopic fine particles to a sheet like structure, has >=3 deg.C of maximum temperature rise in moisture uptake and/or water absorption, and sustains heat generation in the moisture uptake for >=30 min, and/or for >=1 min in the water absorption or >=8 deg.C of maximum temperature rise in water absorption.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to industrial materials such as agricultural materials and building materials, sports equipment materials such as mountaineering equipment, camping equipment, bedding interior materials, tents, hoods, etc. The present invention relates to a dew condensation preventive material.

[0002]

2. Description of the Related Art Conventionally, in greenhouse cultivation in cold regions and intermediate mountainous areas in the agricultural field, the indoor temperature begins to drop after sunset, and dew condensation occurs from night to before sunrise, which adversely affects cultivated crops. Therefore, energy such as electric power energy and fossil fuel was released at night and kept at the temperature before the dew point. In the field of construction, a space is also provided between the outer wall and the inner wall, and a flame-retardant or non-combustible to quasi-non-combustible poor thermal conductivity material (for example, glass wool insulation material) is packed in the space to prevent dew condensation in the room. It was suppressed. However, when the energy cost is added to the production price in the agricultural field, it becomes less competitive and is one of the factors that diminishes the profits of producers. On the other hand, even in the field of construction, it is possible to deal with the condensation on the wall by the above-mentioned method, but the prevention of the condensation on the window is dealt with by the double glass method, but the price is unavoidably higher than that of the single item. In addition, it was not uncommon for tents and membrane equipment to also generate dew condensation inside when the temperature of the outside air drops or when it rains. However, none of these conventional methods is not only costly, but also satisfactory in dew condensation prevention.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a dew condensation preventing material which can be manufactured by a simple process, is low in cost and is excellent in dew condensation preventing property.

[0004]

The present invention has the following technical constitution for solving the above problems. That is, 1. A dew condensation preventing material, which is a sheet-like structure to which highly hygroscopic fine particles are attached, and has a maximum temperature rise of 3 ° C. or more during moisture absorption and / or water absorption.

2. The dew condensation preventing material according to the first aspect is characterized in that the heat generation during moisture absorption is maintained for 30 minutes or more and / or the heat generation during water absorption is maintained for 1 minute or more.

3. The dew condensation preventing material according to the first or second aspect, wherein the maximum temperature rise during water absorption is 8 ° C. or higher.

4. The dew condensation preventing material as described in any one of 1 to 3, wherein the highly hygroscopic particles are organic particles.

5. The highly hygroscopic organic fine particles are polystyrene-based, polyacrylonitrile-based, polyacrylic acid ester-based, or polymethacrylic acid ester-based vinyl polymers, and have sulfonic acid groups, carboxylic acid groups, phosphoric acid groups, or their metals. The dew condensation preventing material according to the fourth aspect, which is a cross-linked polymer having at least one hydrophilic group of a salt and cross-linked with either divinylbenzene, triallyl isocyanate or hydrazine.

6. Highly hygroscopic fine particles have an average particle size of 2 μm
6. The dew condensation preventing material as described in any one of 1 to 5, which is less than 1.

7. 7. The dew condensation preventing material as described in any one of 1 to 6, wherein the highly hygroscopic fine particles are fixed to the sheet-like structure through a hydrophilic resin.

8. 8. The dew condensation preventing material as described in any one of 1 to 7, wherein a mass ratio of the highly hygroscopic fine particles and the hydrophilic resin is 1/1 to 20/1.

9. 9. The dew condensation according to any one of 1 to 8, wherein the sheet-like structure is a knitted fabric, a woven fabric, a non-woven fabric, a fleece, a film or a resin molded product, which is composed of natural fibers, synthetic fibers or mixed fibers thereof. Preventive material.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. The sheet-like structure used in the present invention is a polyester-based, polyamide-based, polyacrylonitrile-based, polyethylene-based, polypropylene-based, polybutylene terephthalate-based, polytetramethylene terephthalate-based, polyurethane-based, polyphenylene sulfide-based synthetic fibers, Chemical fibers such as rayon and acetate,
A structure composed of a knitted fabric, a woven fabric, a non-woven fabric, a fleece, a film, a resin molded body, or the like made of natural fibers such as cotton, hemp, silk, wool, and feathers, or a mixed material thereof.

Highly hygroscopic fine particles of the present invention (hereinafter referred to as high moisture absorption /
Also referred to as water-absorbing exothermic particles. ) Is not particularly limited in terms of chemical structure as long as it is a fine particle that exhibits exothermicity when absorbing moisture or absorbing water. For example, inorganic type such as hygroscopic silica, or hygroscopic polyurethane type, polyamide type,
It is possible to apply various organic fine particles such as polyester-based and polyacrylate-based, but particularly high moisture-absorption / water-absorption exothermic organic fine particles are preferable, and examples thereof include polystyrene-based, polyacrylonitrile-based, polyacrylic ester-based, and polyacrylic ester-based. A methacrylic acid-based vinyl polymer having a sulfonic acid group, a carboxylic acid group, a phosphoric acid group, or at least one hydrophilic group of metal salts thereof, and having divinylbenzene, triallyl isocyanate, or It is a crosslinked polymer fine particle crosslinked with any of hydrazine.

The particle size of the highly hygroscopic fine particles is preferably as small as possible from the viewpoint of moisture absorption / water absorption heat generation rate / heat generation efficiency, uniform adhesion, texture and abrasion resistance, and an average particle diameter of less than 2 μm is more preferable.

The method for applying the highly hygroscopic fine particles of the present invention is a method of directly kneading into a fiber, a film or a resin layer, or coating the surface layer of a knitted fabric, a woven fabric, a non-woven fabric, a fleece, a film and a resin molded product through a binder resin. Examples of the method include attaching by dipping, spraying and the like, but the latter method of attaching via a binder resin is preferable from the viewpoint of moisture absorption / water absorption heat generation rate / heat generation efficiency.

As the binder resin, a usual impregnation method,
Examples of the resin include silicone-based, urethane-based, acrylic-based, polyester-based, polyamide-based, and polyethylene oxide-based resins that can be applied to the padding method, coating method, and spray method, and are not particularly limited, but hydrophilic, that is, hygroscopicity, water absorption. It is desirable to use a type that has excellent properties and moisture permeability, does not inhibit the excellent hygroscopicity and water absorption of the highly hygroscopic fine particles, and has an excellent binder function that can effectively bond and fix the highly hygroscopic fine particles and the structure. As a particularly preferable hydrophilic resin binder, as a hydrophilic segment, a polyalkylene oxide addition type, a polar hydrophilic group type such as a sulfonate or a carboxylate, a hydrophilic silicone resin having amide modification or the like introduced therein, a hydrophilic urethane Examples thereof include resins, hydrophilic polyamide resins, and hydrophilic polyethylene oxide resins, which have high hygroscopicity and moisture permeability of the resin themselves and do not impair water absorption. The moisture permeability of the resin as used herein means the moisture permeability in a non-porous film state. Even in the case of a resin having a high moisture permeability expressed in a microporous film, a binder resin having a low hygroscopicity and a low water absorptivity of the resin itself masks and lowers the excellent moisture absorption / heat generation characteristic of the high moisture / water absorption heat-generating fine particles. In addition, in order to improve the durability, these high moisture absorption / water absorption exothermic fine particles and hydrophilic resin binder are combined with various crosslinking agents such as isocyanate type, methylol type, ethyleneimine type, polyfunctional aziridinyl type, and metal salt type. You may use together in the range which does not reduce the original moisture absorption / water absorption.

The compounding ratio of the highly hygroscopic / water-absorbing exothermic fine particles and the hydrophilic resin and the amount of these adhering to each other greatly influence the hygroscopic / water-absorbing exothermicity. The compounding ratio of the highly hygroscopic / water-absorbing exothermic fine particles and the hydrophilic resin is slightly different depending on the hydrophilic level of the hydrophilic resin, but it is usually desirable to use the compounding ratio of 1/1 to 20/1, preferably 10/1 to 19/1. More preferably, the compounding ratio of 15: 1 to 19/1,
In particular, the smaller the blending ratio of the hydrophilic resin, the better the moisture absorption / water absorption exothermicity can be exhibited. However, when the hydrophilic resin is extremely small, or when the hydrophilic resin is not used in combination, the abrasion resistance of the highly hygroscopic / water-absorbing heat-generating fine particles adhered to the surface of the structure is deteriorated and the particles easily fall off. On the contrary, if the blending ratio of the hydrophilic resin is high, even if it is a hydrophilic resin, high moisture absorption /
Since the moisture absorption / water absorption inherent to the water absorption / heat generation fine particles is often impaired, the moisture absorption / water absorption heat generation rate and the heat generation amount are extremely reduced due to the masking effect. Of course, when the moisture absorption / water absorption of the hydrophilic resin is equal to or higher than that of the high moisture absorption / water absorption exothermic fine particles, the compounding ratio of the hydrophilic resin can be increased.

The amount of the high moisture absorption / water absorption exothermic fine particles applied to the dew condensation preventing material is preferably 5 g / m ² or more. It is more preferably at least 10 g / m ^{2, and even} more preferably at least 20 g / m ² . This is because the larger the amount, the greater the heat generation effect. If it is less than 5 g / m ² , the heat generation effect is small, and if the heat generation duration is less than 5 minutes, the dew condensation prevention effect cannot be expected.

The dew condensation preventing material of the present invention not only absorbs dew condensation due to moisture absorption / water absorption, but also positively utilizes heat generated by moisture absorption / water absorption to achieve dew condensation prevention. This exothermicity is
It depends on the heat of adsorption reaction generated when the substance absorbs moisture or absorbs water, and therefore depends on the hygroscopic ability and / or the water absorbing ability and the amount of adhesion of the highly hygroscopic / water-absorbing fine particles and the combined hydrophilic resin binder contained in the structure. . That is, the higher the hygroscopic / water-absorbing fine particles, and the finer the hydrophilic resin binder having a higher hygroscopic or water-absorbing level, the larger the heat production due to the adsorbed moisture, the faster the heat generation rate, and the longer the heat retention time. Of course, since such a moisture absorption / water absorption is possessed by the structure substrate alone, in order to realize more effective moisture absorption / water absorption exothermicity, the moisture absorption rate of the applied moisture absorption / water absorption exothermic fine particles (20 ° C., 65% RH ) Is preferably 25% or more, more preferably 40% or more. In addition, the combined hydrophilic resin does not hinder the hygroscopicity / water absorption of the moisture-absorbing / water-absorbing exothermic fine particles as much as possible.
% RH) 3 to 50% is preferable. That is, in order to obtain an effective moisture absorption / water absorption exothermicity, the structure having a high degree of moisture absorption / water absorption exothermicity of the present invention has a moisture absorption rate as low as possible, more preferably close to a completely dry (absolute dry) state. It is essential to store it in the state. On the other hand, the structure that has adsorbed moisture at a saturated moisture absorption rate or higher and has completed heat generation is cooled by heat radiation and drops to the initial temperature, but if it is dried again to remove the adsorbed water, the original excellent moisture absorption / Water absorption and exothermicity reappear.

The moisture absorption exothermicity in the gas phase heats up at an appropriate rate and maintains the exothermicity for a relatively long time, while the water absorption exothermicity in the liquid phase gives a rapid exothermicity, while the adsorbed water If the amount is too large, the remarkable heat generation effect may not be obtained, so it is important to control the amount of attached water. In particular, when it is desired to heat rapidly, such as in an emergency, the water absorption and heat generation function of the present invention is effective, and when combined with the moisture absorption and heat generation function that has a long heat generation retention time, it is possible to design a more sophisticated product for preventing dew condensation.

According to the present invention, the type and the amount of the highly hygroscopic / water-absorbing exothermic fine particles are optimized, and the sheet-like structure adhered via an appropriate hydrophilic resin binder has a property of absorbing moisture and / or absorbing water. Maximum temperature rise is 3 ℃ or more, preferably 4
℃ or more, more preferably 5 ℃ or more, rapid (3 ~
The maximum temperature rise during water absorption (for 5 seconds) is 8 ° C or higher,
Moreover, the total heat generation of moisture absorption / water absorption heat generation rate, heat generation amount, heat generation retention time, such as heat generation retention time when moisture absorption is 30 minutes or more, or heat generation retention time when water absorption is 30 seconds or more, more preferably 1 minute or more In terms of performance, excellent moisture absorption /
Water absorption and exothermicity are obtained.

The anti-condensation material of the present invention has antibacterial and deodorant properties, antibacterial properties, deodorizing properties, nonenal deodorizing properties, pH buffering properties, antistatic properties, It is also possible to develop multifunctional properties such as SR antifouling property and acid rain resistance.

Further, when the outside air temperature decreases, the humidity in the room increases due to a condensation tendency, and even if the temperature further decreases to the dew point, the dew condensation preventing material of the present invention absorbs the increasing humidity. This causes heat to be generated, and works to prevent or maintain or increase the decrease in room temperature to prevent it from reaching the dew point.The ripple effect is that absorbed moisture is released during the day, and the heat of vaporization at that time increases the room temperature. There is also an advantage that it also temporarily suppresses.

[0025]

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. Below, what is described simply as part and% means on a mass basis. Further, the measurement and evaluation of the sheet-shaped structure in this example were carried out by the following methods.

<Absolute dry mass> After drying the sample at 110 ° C for 6 hours, the sample was placed in a desiccator containing silica gel and kept at 20 ° C for 6 hours.
After adjusting the temperature in a 5% RH environment, mass measurement was performed. <Hygroscopicity> The mass was measured after the temperature and humidity were adjusted for 24 hours in an environment of 20 ° C. and 65% RH, and calculated from the following formula. Moisture absorption rate (%) = {(moisture absorption mass-excess dry mass) / excess dry mass}
× 100

<Heat absorption by moisture absorption> After drying at 110 ° C. for 6 hours,
5c put in desiccator containing silica gel and dried
20 after mounting a temperature sensor (for example, manufactured by Anritsu Keiki Co., Ltd .; 540K MD-5 type) on a measurement sample measuring m × 5 cm.
Temperature recorder (for example, manufactured by Anritsu Keiki Co., Ltd .; DATA COLLECTOR A)
M-7052 type). <Water absorption exothermicity> After attaching a temperature sensor to the 5 cm x 5 cm measurement sample in the absolutely dry state, ion exchanged water equivalent to 50% of the sample mass is uniformly added to 3 to 5 at 20 ° C and 65% RH environment. After spraying for 2 seconds, the water absorption exothermicity was measured with a temperature recorder. The water absorption heat generation time and the water absorption heat generation retention time (minutes) above the maximum water absorption heat generation temperature and the sample temperature before water absorption were evaluated.

<Condensation property> 2 at 20 ° C. and 65% RH
Humidity control for 4 hours, mass measurement of sample at 20 ℃, 95%
After conditioning the humidity for 6 hours in an RH environment, the presence or absence of dew condensation on the surface of the sample was visually determined.

The highly hygroscopic / water-absorbing exothermic organic fine particles used in the examples were produced by the following method. Water-soluble polymer 3 of methacrylic acid / sodium p-styrene sulfonate = 70/30
50 parts and 35 parts of sodium sulfate were dissolved in 6500 parts of water and charged into a polymerization tank equipped with a paddle-type stirrer. Next, 15 parts of 2,2'-azobis- (2,4-dimethylvaleronitrile) was dissolved in 2750 parts of methyl acrylate and 330 parts of divinylbenzene and charged into a polymerization tank at 400 rpm.
Polymerization was carried out at 60 ° C. for 2 hours with stirring to obtain a copolymer having a polymerization rate of 88%. 100 parts of the polymer is dispersed in 900 parts of water, 110 parts of caustic soda is added thereto, and 90 ° C.
After reacting for 2.5 hours, the methyl ester portion of methyl acrylate is hydrolyzed to give a carboxyl group 4.6.
A crosslinked polymer having a milliequivalent / g was obtained. The obtained polymer was dispersed in water, washed, dehydrated, and then pulverized, divided or filtered to obtain highly hygroscopic / water-absorbing exothermic particles. The obtained highly hygroscopic / water-absorbing exothermic organic fine particles had a moisture absorption rate of 50% at 20 ° C. and 65% RH, and an average particle diameter of 0.8 μm.

[Example 1] TF was used as a hydrophilic resin binder in 95 parts of an aqueous dispersion containing 20% of the highly hygroscopic / water-absorbing exothermic fine particles on a polyester cloth having a basis weight of 170 g / m ^2.
-3500 (Kao's hydrophilic silicone binder; solid content 40%) 2.5 parts of a polyester cloth is dipped in a processing liquid and wet picked up by a mangle 70%
Squeeze to 100 ° C, dry at 100 ° C for 3 minutes, then 170
Cured for 1 minute at ℃, processed cloth (sheet structure)
Got The basis weight of the obtained processed cloth was 193 g / m ² . As a method for measuring heat generation effect, a work cloth (50 cm ² =
1.05 g) was dried at 110 ° C. for 2 hours to completely remove water, and then stored in a desiccator containing silica gel.
Next, this work cloth was taken out from the desiccator and put into a desiccator (95% RH) saturated with potassium sulfate, and temperature rise data was collected by a temperature sensor and a temperature recorder. The temperature sensor used at this time is 540KMD-5 = Anritsu Keiki Co., Ltd., and the temperature recorder is DATA CO- LLECTOR AM-705.
2 = Anritsu Keiki Co., Ltd. The measurement environment is 20 ℃ ×
65% RH. Table 1 shows the heat generation effect and the dew condensation prevention effect of the obtained work cloth.

Example 2 Example 1 is the same as Example 1 except that the solid content of the working liquid is 25% of that of Example 1.
A processed cloth was obtained in the same manner as in. The heat generation effect and the dew condensation prevention effect of the obtained work cloth were measured in the same manner as in Example 1.

[Comparative Example 1] With respect to the unprocessed cloth used in Example 1, the heating effect and the dew condensation preventing effect were measured in the same manner as in Example 1.

Table 1 summarizes the heat generation effect and the dew condensation prevention effect of the examples and comparative examples.

[Table 1]

[0034]

EFFECTS OF THE INVENTION According to the present invention, by adhering highly hygroscopic exothermic fine particles to a knitted fabric, woven fabric, non-woven fabric, fleece, film or sheet-shaped resin molded product through a small amount of hydrophilic resin, moisture in the external environment is absorbed. By absorbing (steam) and water (liquid) and quickly and stably generating heat, a dew condensation preventing material suitable for industrial materials such as agriculture and construction can be easily and stably obtained.

Claims (9)

[Claims] 1. A dew condensation preventing material, which is a sheet-like structure to which highly hygroscopic fine particles are adhered, and has a maximum temperature increase of 3 ° C. or more during moisture absorption and / or water absorption. 2. The anti-condensation material according to claim 1, wherein the heat generation during moisture absorption is maintained for 30 minutes or more, and / or the heat generation during water absorption is maintained for 1 minute or more. 3. The anti-condensation material according to claim 1, wherein the maximum temperature rise during water absorption is 8 ° C. or higher. 4. The dew condensation preventing material according to claim 1, wherein the highly hygroscopic fine particles are organic fine particles. 5. The highly hygroscopic organic fine particles are polystyrene-based,
Polyacrylonitrile-based, polyacrylic ester-based,
Any vinyl polymer of polymethacrylic acid ester type, having a sulfonic acid group, a carboxylic acid group, a phosphoric acid group, or at least one hydrophilic group of metal salts thereof,
The dew condensation preventing material according to claim 4, which is a crosslinked polymer crosslinked with divinylbenzene, triallyl isocyanate or hydrazine. 6. The dew condensation preventing material according to claim 1, wherein the highly hygroscopic fine particles have an average particle diameter of less than 2 μm. 7. The dew condensation preventing material according to claim 1, wherein the highly hygroscopic fine particles are fixed to the sheet-shaped structure through a hydrophilic resin. 8. The mass ratio of the highly hygroscopic fine particles to the hydrophilic resin is from 1/1 to 20/1.
The anti-condensation material according to any one of 1. 9. The sheet-like structure is a knitted fabric, a woven fabric, a nonwoven fabric, a fleece, a film, or a resin molded product composed of natural fibers, synthetic fibers, or a mixture of these fibers. The dew condensation prevention material described in any of the above.