JPS63110223A - Anti-sweating material - Google Patents

Abstract

PURPOSE:To obtain a material of anti-sweating capability despite one consisting mainly of polymer, with moisture permeability, hygreoscopicity, water absorptivity and waterproof capability, thus suitable for winter clothes, raincoats, etc., by kneading a polymer sheet with activated carbon powder. CONSTITUTION:The objective material can be obtained by kneading a polymer sheet (pref. of polyurethane) with 10-200wt% of activated carbon powder. This material has a moisture absorption >=5wt% (at 20 deg.C and 90% RH) and water adsorption >=5wt%. The production process is, for example, as follows: a polar organic solvent solution of a polyurethane polymer containing activated carbon powder is coated on the surface of a fiber base material in a filmy manner to form a sheet product. The particle size of said activated carbon is pref. 60-100mu.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a sheet-like material mainly made of a high molecular weight polymer, but it has dew condensation prevention properties, and has moisture permeability, hygroscopicity, water absorbency, and waterproofing properties. The present invention relates to a dew-preventing material suitable for cold weather clothing, rain clothing, etc.

[Prior Art] Various waterproof coated fabrics have been proposed and put into practical use. In particular, waterproof coating fabrics that are inexpensive and relatively easy to manufacture, such as vinyl chloride, synthetic rubber, acrylic ester resins, urethane resins, amino acid resins, etc. coated on fabric-like III fiber base materials, are used for waterproof clothing such as raincoats. used in however,
Although these base materials are somewhat effective in terms of waterproofness, when worn as clothing, they cause discomfort due to stuffiness, and when used in tents, water vapor condenses inside the tent, causing water droplets to fall from the ceiling. There are drawbacks.

On the other hand, as a waterproof fabric that emphasizes moisture permeability to reduce stuffiness when worn, Tokuko Sho 60-47954,
Transparent, waterproof coated fabrics such as those found in -47955 have been proposed and put into practical use. However, although these base materials have some effect in terms of moisture permeability and waterproofness, when worn as clothing when the outside temperature is low, water droplets may adhere to the warm side of the clothing, that is, the surface of the coating film. There is a drawback that condensation occurs.

[Problems to be Solved by the Invention] The purpose of the present invention is to improve the above-mentioned drawbacks of the prior art, and to improve the above-mentioned drawbacks of the prior art, it is possible to use a material that is mainly made of a high molecular weight polymer, but has dew condensation prevention properties, moisture permeability, and moisture absorption. The purpose of the present invention is to provide an anti-condensation agent that has excellent water absorption, water absorption, and waterproof properties.

Means for Solving Problem E] In order to achieve the above-mentioned object, the present invention has the following configuration. That is, (1) A polymer sheet in which 10 to 200% by weight of activated carbon powder is mixed, and the moisture absorption rate is 5.0% or more (
An anti-condensation material having a water absorption rate of 5.0% or more at 20°C and 90% RH.

(2) The dew condensation prevention material according to claim (1), wherein the activated carbon powder has a particle size of 40 to 250 μm.

(3) The dew condensation prevention material according to claim (1), wherein the polymer sheet is laminated on a fiber base material.

(4) The dew condensation prevention material according to claim (1), wherein the high molecular weight polymer is a polyurethane polymer.

(5) The polymer sheet has a condensed moisture content of 3 Mm.
The dew condensation prevention material according to claim (1) has a dew condensation prevention material of 2 minutes or less.

As the high molecular weight polymer used in the present invention, high molecular weight polymers such as synthetic rubber, polyurethane, polytetrafluoroethylene, silicone resin, polyethylene, polypropylene, polyvinyl chloride, polyacrylic acid ester resin, and amino acid resin can be used. However, polyurethane is particularly suitable.

The polyurethane is preferably polyester-based or polyether-based, and can generally be formed into a film by dry or wet coagulation.

Furthermore, as the powdered activated carbon to be kneaded into the high molecular weight polymer, those obtained mainly from sawdust, coconut shells, coal, etc. can be used.

Regarding the size of the powder particles, when the high molecular weight polymer is formed into a sheet, it is preferable that the film surface has an uneven surface, and the particle size is preferably larger than 40 μm and finer than 250 μm.

More preferably, the particle size is 100μ rather than 60μ. If the particle size is smaller than 40 μm, the particles are too fine, and when the synthetic polymer is formed into a sheet-like film, the surface becomes difficult to have unevenness and becomes mirror-like, which is not preferable.

In addition, if the particle size is larger than 250μ, the particles are too large, and when the synthetic polymer is formed into a sheet-like film, the thickness tends to be uneven, and the activated carbon powder may jump out of the film and rub against other objects. This is undesirable because it may peel off, the film may tear, or it may damage or stain other objects.

Activated carbon has a high moisture absorption rate of 31.7% (20℃, 90% RH), as well as water absorption and deodorizing properties. It has characteristics that are significantly higher than those required in the old R.

In the present invention, this activated carbon is powdered and kneaded with a polymer to form a sheet, thereby preventing dew condensation and moisture absorption without reducing the waterproofness and moisture permeability inherent to the polymer. It becomes possible to impart properties and water absorption properties.

The kneading ratio of this activated carbon powder to the high molecular weight polymer was 10
~200% by weight, more preferably 30-150% by weight
It is preferable that If it is less than 10% by weight, the hygroscopicity will be lower than the level of cotton fiber, and if it is less than 20% by weight,
When the amount is more than 0% by weight, when coating the surface of a fiber base material with a high molecular weight polymer in the form of a film, the film is likely to peel off or fall off.

In addition, in the present invention, when kneading activated carbon powder,
Other water absorbing agents (such as anionic surfactants), deodorizing agents, fragrances, etc. may be mixed.

In the present invention, the activated carbon-containing polymer sheet has a moisture absorption rate of 5.0% or more, preferably 6.0% or more (2.
It is important that the temperature is 0'C, 90% RH) and the water absorption rate is 5°03 or more.

The polymer sheet of the present invention may be non-porous, but microporous is preferably selected from the viewpoint of moisture permeability. Activated carbon acts synergistically on moisture permeability, hygroscopicity, and water absorption.

In any case, in order to greatly improve the dew condensation prevention effect, it is necessary to select a structure that satisfies the above-mentioned hygroscopicity and water absorption.

The polymer sheet of the present invention has a condensed water content of 3 Mm.
・Minutes or less, preferably 2 (]/m2・minutes or less, is selected based on the ability to form water droplets. If the amount of condensed water exceeds the above range, it tends to cause wetness on clothes and skin. So I don't like it.

The high molecular weight polymer kneaded with activated carbon powder may be used by itself in the form of a microporous sheet, but it is preferably used in the form of a fabric such as a knitted fabric or a nonwoven fabric. It is best to use it by coating the surface of the material in the form of a film.

FIG. 1 is a sectional view of the dew condensation prevention material according to the present invention. 1st
In the figure, a dew condensation prevention material 1 is made by coating the surface of a fabric-like fiber base material 2 with a film 4 of a high molecular weight polymer kneaded with activated carbon powder 3. This coating film may be provided on both sides of the fiber base material 2.

By combining the fiber base material 2 and the film 4 in this manner, the tensile strength and tear strength of the polymer film are reinforced, and its uses can be significantly expanded.

An example of a method for manufacturing the dew condensation prevention material of the present invention will be described below, using a polyurethane polymer as a high molecular weight polymer and using a typical method of coating a fiber base material with the polyurethane polymer.

First step: In order to suppress the penetration of the polyurethane polymer solution mixed with activated carbon powder into the fiber base material to less than the thickness of the fiber base material, and to give the base material a water-based function. Perform processing as described below.

Second step: A polar organic solvent solution mainly containing a polyurethane polymer mixed with activated carbon powder is applied to at least one side of the fiber base material of the first step.

Third step: The sheet material after the second step is immersed in a coagulation liquid to form a microporous polyurethane film containing activated carbon.

In the present invention, the first step may be omitted and the second and third steps may be carried out, but in order to improve the moisture absorption and moisture permeability as well as the feel of the coated fabric, the It is desirable to perform a one-step pretreatment. As a pretreatment method, the surface of the fiber base material and the surface to which the activated carbon-containing polyurethane polymer solution is applied is heated and pressurized to change the cross-sectional shape of the fibers and narrow the fiber gaps. There are methods of applying water repellents such as silicone-based or fluorine-based water repellents. It is also preferable to apply a subbing undercoat to further improve adhesion.

By appropriately applying these pretreatment means to the fiber base material, when applying the activated carbon-containing polyurethane polymer solution, it is possible to suppress the permeation of the polymer solution into the fiber base material, and at the same time to inhibit the synthesis with the fibers constituting the fiber base material. By relaxing the bond with the polymer, it is possible to obtain an activated carbon-containing resin-coated fabric that has a soft feel and is highly hygroscopic and moisture permeable.

In addition, if the activated carbon-containing polyurethane polymer solution penetrates into the fiber base material in the thickness direction, one-third or more of the thickness of the fiber base material,
Physical properties such as permeability and tear strength, as well as flexibility, begin to decline.

The composition of the polyurethane polymer solution used in the above manufacturing method is as follows: A polar organic solvent solution represented by dimethylformamide containing 8 to 25% by weight of the polyurethane polymer, and 0.1 to 1 to 1% of the fluorine-based water repellent. 0.0% by weight, 0.2 to 3% by weight of polyisocyanates, and 1 to 10% by weight of a nonionic surfactant. 10 to 200% by weight of the activated carbon based on the polyurethane polymer is mixed into this liquid mixture, and the mixture is produced by a wet coagulation method.

The above-mentioned liquid mixture is coated uniformly to a desired thickness using a knife-over-roll coater or other ordinary coating machine.

- The third step is not particularly limited, but it is advantageous to use an aqueous solution containing 5 to 15% by weight of dimethylformamide as the coagulation bath.

[Example] Evaluation items used in Examples will be explained.

(1) Irregularities on the surface of the film: Take a photograph of the cross section of the film at 150x magnification using a scanning electron microscope, and draw a 10cm straight line on the photograph.
The length of the locus of the cross section corresponding to the membrane surface between the two was measured and expressed.

(2) Condensation moisture content: 2,000 to 4,000 water at a water temperature of 60°C
Place an 18 x 18 x 5 on (vertical x horizontal x height) box containing ice at a distance of 5 to 10 CIn from the water surface in a container containing cc, and make 9-fold, 9-cm (vertical x horizontal) holes in the top of the box. Place a sheet of material (sample>10X) to cool the hole.
10×10 vertically and horizontally) was attached, and the moisture It (A) condensed in 60 seconds was measured using the following formula.

Condensed moisture content (A>=B-C B: Total weight of sheet material with dew condensation for 60 seconds C: Weight after wiping off moisture on the film of sheet material with filter paper (3) Moisture absorption rate: JIS L1096 However, fiber The base material must be made of chemical or synthetic fibers such as polyamide fibers.Conducted at 20℃ and 90%RH conditions.

(4) Water absorption rate: 10 x 10 c1n (vertical x horizontal) After pasting a sample 10 x 10 x 10 vertical x horizontal on a 5 mm thick cardboard paper and immersing it in water at a depth of 2 to 3 nm with the sample facing down for 60 seconds. The water absorption rate (X%) was determined using the following formula.

Water absorption rate X (%) = (Y-Z)/ZXI00Y: Total weight of the sample after being immersed for 60 seconds, removing the sample from the cardboard paper, and wiping off the moisture adhering to the film surface with a paper towel.

Z: Surrounding of sample before immersion (5) Moisture permeability: According to JIS Z-0208.

(6) Water pressure resistance: According to JIS L-1079.

Dyed nylon taffeta (vertical and horizontal 70d nylon filament used, vertical density x horizontal density = 123 x 8
7 bottles/inch) with 60% squeezing rate of fluorine-based water repellent aqueous dispersion
The amount of fluorine-based water repellent applied is 0.3% by weight.

For example, this treatment was treated as water-repellent treatment of the base material.

A coating liquid (viscosity 6000 cos/25°C) consisting of 100 parts by weight of polyester polyurethane solution, 4 parts by weight of polyisocyanate, and 30 parts of methyl ethyl ketone was applied to the previously treated fabric using the knife float coating method at a ff of 130 g/m2, dried and bonded. layered.

Incidentally, this adhesive layer also has the function of separating the fabric-like fiber base material and the microporous layer containing activated carbon, and preventing the activated carbon from contaminating the fiber base material.

Next, a polyurethane coating solution consisting of 18 parts by weight of polyester polyurethane, 9 parts by weight of coconut shell activated carbon (74 to 149μ), and 70 parts by weight of dimethylformamide was coated at 150 g/(W) using a knife-over-roll coater.
et) After 1 cloth, it was immersed in water containing 3% dimethylformamide to coagulate, washed with water, and rapidly dried with hot air to obtain a sheet-like material containing activated carbon and having fine pores.

The results obtained are shown in Table 1.

However, level 1 is 100% polyester as the fiber base material.
Taffeta treated with a water-repellent calender was used. Then, a polyurethane solution containing activated carbon was directly applied, wet-coagulated, and dried, without applying a polyurethane solution that would become an adhesive layer. After that, the taffeta and urethane film were peeled off.

The following were listed as comparative examples.

Comparative Example 1 was obtained by applying a dimethylformamide solution of polyester polyurethane without kneading coconut shell activated carbon to the base fabric treated to the adhesive layer and coagulating it by reheating in the same manner as in the example.

Comparative Example 2 is a commercially available product from Company B in which nylon taffeta is coated with a polyurethane film having fine pores (open cells formed by wet treatment).

Comparative Example 3 is a 100% cotton fabric.

As is clear from Table 1, the dew condensation prevention material according to this example has less condensed water than the microporous film of Comparative Example 1.2, which does not contain activated carbon, and the moisture absorption rate, water absorption rate, and film This indicates that the moisture permeability, waterproofness, and dew condensation prevention properties are improved due to the large unevenness of the surface.

For 100% cotton fabrics, the large unevenness on the membrane surface is due to the unevenness of the threads of the fabric being directly formed, whereas the other differences are that the coating surface is flattened.

In addition, 100% cotton fabric has a high moisture absorption rate, moisture permeability, and water absorption rate, and its condensed moisture is O, which is a characteristic unique to cotton, but its water resistance is O, and it does not have a waterproof function.

[Reference example] The samples shown in Table 2 were prepared under the following conditions.

Activated carbon was added to a ketone solvent solution containing 25% by weight of polyurethane while changing the particle size and cross-mixing ratio (weight ratio to polyurethane), and kneaded with a screw type stirrer. This kneading solution was coated with ioo g/, Tr12 (Δet) using a knife coater on a fabric made of 100% nylon filament. After drying, it was immersed in a solution containing 1% by weight of a fluorine-based water repellent and heated. After setting, the coating film surface was washed with water and quickly dried. (Non-microporous membrane) FIG. 2 is a graph showing the relationship between the unevenness of the membrane surface and the amount of condensed water among the results in Table 2.

FIG. 3 is a graph showing the relationship between the unevenness of the film surface and the moisture absorption rate among the results shown in Table 2.

As is clear from FIGS. 2 and 3, it can be seen that as the unevenness of the film surface increases, the amount of condensed water decreases and the moisture absorption rate increases.

As can be seen from Table 2, as the particle size of the activated carbon increases and as the kneading rate of the activated carbon increases, the unevenness of the membrane surface increases.

Although the particle size of the activated carbon was not changed in this example, it is presumed that a similar tendency would be exhibited even if the particle size was changed (irregularities on the film surface).

[Effects of the invention]- As mentioned above, the dew condensation prevention material of the present invention not only has inherent waterproofness and moisture permeability due to the microporous polymer film, but also has high moisture absorption due to the activated carbon powder mixed in. It has properties such as water absorption, and anti-condensation properties. Therefore, even when worn as clothing when the outside temperature is low, it is possible to prevent or reduce the formation of dew on the inside.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the dew condensation prevention material according to the present invention. Second
The figure is a graph showing the relationship between the unevenness of the film surface and the amount of condensed water among the results in Table 2. FIG. 3 is a graph showing the relationship between the unevenness of the film surface and the amount of moisture absorption among the results shown in Table 2. In the figure: 1: Condensation prevention material 2: Fabric-like fiber base material 3: Activated carbon powder 4: Coating

Claims (5)

[Claims] (1) A polymer sheet kneaded with 10 to 200% by weight of activated carbon powder, and having a moisture absorption rate of 5.0% or more (
An anti-condensation material having a water absorption rate of 5.0% or more at 20°C and 90% RH. (2) The dew condensation prevention material according to claim (1), wherein the activated carbon powder has a particle size of 40 to 250 μm. (3) The dew condensation prevention material according to claim (1), wherein the polymer sheet is laminated on a fiber base material. (4) The dew condensation prevention material according to claim (1), wherein the high molecular weight polymer is a polyurethane polymer. (5) The polymer sheet has a condensed water content of 3g/m^2
The dew condensation prevention material according to claim (1), which has a dew condensation prevention material of less than .