JPS6018354B2 - fibrous waterproof fabric - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a waterproof canvas, a fibrous waterproof fabric such as Turbolin, in which a coating made of synthetic resin or rubber is formed on one or both sides of a fibrous base fabric, and particularly, The present invention relates to a fibrous waterproof fabric that has been subjected to necessary surface treatments to form an acute angle of contact with aqueous droplets on the surface of the fabric.

For example, waterproof canvas, turbolin, etc. are made by treating cotton canvas with paraffin, metal alumina soap, etc. to make it waterproof, and then highly hydrophobically treating the surface to make it water repellent. It had the property of being able to withstand the pressure of an aqueous liquid and also repelling the liquid.

After that, synthetic fibers became the main base fabric and were prized for their high strength and light weight, and so-called impermeable canvas made of synthetic fibers covered with plastic or rubber on one or both sides became widely available. At present, products are manufactured that have a water resistance of 100 meters or more and have good water repellency on their surfaces. According to the conventional thinking, the plastic or rubber coatings used are inherently hydrophobic, and it was even believed that hydrophilic substances could not function as a waterproof cloth. As a result, when evaluating waterproof canvas, turbolin, etc., water resistance is an essential item. For example, in the JIS standard for evaluating the waterproofness of textile products, ``Product Waterproofness Test Method'' requires three types of tests: ``11'' water resistance, ``2'' water repellency (spray test), and ``3'' rain sample (shower test). However, the inventors
Completely waterproof and impermeable fabric made by covering a fibrous base fabric, especially a synthetic fiber base fabric with rubber or plastic, etc., for freight car hoods,
From our experience in practical use in warehouses, tents, etc., these waterproof fabrics are essentially highly water resistant, and they appear to have good water repellency against direct wetting, especially in the early stages of use. Although it is preferable, for example, if the hood is
When there is a temperature difference between the outside temperature and the inside temperature in a tent due to low outside temperature or high inside temperature, the moisture inside is condensed and aggregated at the inner interface of the waterproof fabric, and the surface has good bran water properties. Therefore, it was confirmed that this was rather inconvenient because it turned into water droplets and fell down, contaminating the cargo, stored items, etc.

As a solution to this problem, the inventors of the present invention
No. 7 (Samurai Kaisho No. 56-20679) provides a technology using water-absorbing substances.

Here, it has been said that the surface of waterproof canvas, Turbolin, etc. must be water-resistant, but in reality, if waterproof canvas, Turbolin, etc. have sufficient water pressure resistance, the surface of the waterproof canvas, Turbolin, etc. Regardless of appearance or practice, it does not essentially have to be particularly water-repellent; rather, if the coating contains a water-insoluble water-absorbing substance, as provided in the above-mentioned invention, water droplets may It has been found that a preferable result is obtained in which the particles do not form on the surface and drip, but are quickly cast and erased along the inner surface, and the inner surface is maintained beautifully.

Furthermore, as a result of consideration, it was thought that conventional waterproof fabrics had to have high water pressure resistance to prevent water from seeping through, and water resistance was essential to prevent water from adhering to them.
The main body only needs to be resistant to water pressure to the necessary extent, and does not necessarily need to be water-resistant; on the contrary, the surface may have properties that make it easy to get wet; on the contrary, it should be actively made easy to get wet. It has been found that the surface of the main body is uniformly cleaned by rainwater and the like, and that the flow of rainwater does not become uneven due to the bran-like nature, resulting in a uniform surface cleaning effect. In addition, the surface is water-repellent, or in other words, hydrophobic, which means that it has an affinity for oil-based dirt and is easily stained, and once it becomes dirty, it does not have the ability to be washed away by rainwater, etc., but the surface is water-resistant. In other words, hydrophilicity means that oil-based stains are difficult to adhere to, and even if hydrophilic stains adhere, there is a chance that they will be washed away by moderately repeated rainfall, etc. It was found that there was less dirt. The present invention was made as a result of fundamentally reconsidering the concept of conventional water-proof materials from this point of view. In particular, the presence of a fibrous base fabric is an essential requirement from the function of waterproof fabric, and it is necessary to have sufficient water pressure resistance. However, no hydrophilic treatment is applied, and instead a coating with a hydrophilic surface is formed.

The fibrous base fabric to which the present invention is applied includes spun, filament, split, and
Monofilaments, tape-like materials, other knitted fabrics, non-woven materials, paper-like materials, etc., in which these fibers are densely packed or
It is loosely woven with bran or fixed in a web shape depending on the purpose of use.Glass fiber and other inorganic fibers are also used, but from the purpose of waterproof cloth, at least J.
IS-L-1096-1979 “General textile testing methods” 6
．． 12. Tensile strength and elongation rate It is desirable that the product has a tensile strength of 10k9/3c or more, preferably 30kg/3c or more, and an elongation of 80% or less, preferably 50% or less, according to method A. However, these strengths and elongations are much higher than those required for simple plastic films, and they cannot be considered for applications such as plastic films that lack a fibrous base fabric. It is a performance value. Formation of a rubber or synthetic resin coating on these base fabrics can be performed on either one or both sides by calendering, laminating, topping, coating, dipping, or other known methods.

Synthetic resins include PVC, EVA, polyurethane, acrylic, nylon, ester, and other known ones. Rubbers, both natural and synthetic, are used, especially chlorosulfonated polyethylene, silicone rubber, neoprene, blends of these, and others. A known one is used.

These may be mixed with various pigments, stabilizers, and other tackifying agents in arbitrary proportions. An important feature of the present invention is that the contact angle of the coating surface with respect to aqueous droplets is acute.

It is preferable that the contact angle for the aqueous droplet is as close to 00 as possible so that the aqueous droplet spreads smoothly over the coating surface, but in reality, the coating is formed on the surface of the base fabric, so some unevenness is inevitable. In particular, in the case of spun fabrics that have been impregnated with a synthetic resin liquid, the degree of unevenness is large.
However, the point is that the object of the present invention can be achieved as long as the angle is acute. In this way, methods for making the contact angle of the aqueous droplet on the surface of the coating acute include a method in which a relatively hydrophilic water-absorbing substance or a hydrophilic substance is present on the surface of the coating, and a method using physical energy irradiation. Although other methods can be explored, when using a highly hydrophilic water-absorbing substance, the water-absorbing capacity of the water-absorbing substance is greater than the weight of the substance itself, especially 1.
00 times or more is preferable from the viewpoint of durability.

Specifically, pulp materials, cellulose derivatives, sodium polyacrylate, polyethylene oxide, polyvinylpyrrolidone, sulfonic acid, and the like are effective. Furthermore, when considering the durability of these water-absorbing substances, it is preferable to use water-insoluble and hydrophilic substances. Various substances are used, such as those modified by substitution, such as crosslinked polyethylene oxide, polypiney Z-lupyrrolidone, sulfonated polyethylene, and sodium polyacrylate.
Natural or synthetic materials such as cellulose derivatives, polyacrylonitrile, or saponified products of starch-acrylonitrile graft copolymers are preferable. Among these, the saponified product of starch-ac Z rylonitrile graft copolymer has a water absorption capacity several hundred times its own weight, and is preferable as a water-absorbing material according to the present invention.
In practical use, care must be taken as there is a risk that the starch will rot and the gel structure will be ruptured if it is kept in water for a long period of time. Among these, particularly preferred water-absorbing substances are self-crosslinked alkali metal acrylic salt polymers (JP-A-53-46-9), saponified copolymers of vinylester and ethylenically unsaturated substances or derivatives thereof. A polymer having a chelate-prone bond consisting of a water-dropping polymer having a chelating functional group in the side chain (Japanese Patent Application Laid-Open No. 48-174549), a polymer containing a vinylester and an acrylate or methacrylate ester Combined saponified product (Special Seki Sho 53-150290
), copolymers of vinyl alcohol and acrylates, etc.

Additionally, acrylic fibers containing at least 85% by weight of acrylonitrile are used. Polyacrylonitrile fibers and powder thereof obtained by substantially crosslinking with formalin treatment in the presence of xylamine, hydrazine, or a basic catalyst are also effective. However, the water-absorbing substance according to the present invention is not limited to the examples, but preferably is water-insoluble and has a water-absorbing capacity of 100 times or more its own weight. Note that the multiple of water absorption capacity is indicated here after dispersing a certain amount of a water-absorbing substance into ion-exchanged water, and gently shaking the substance so as not to break the polymer chains that are loosely bonded to it. After being left at room temperature for 30 minutes, excess water is removed from the material that has sufficiently swollen by water absorption, and the weight is measured, and the weight after water absorption and swelling is calculated as the ratio of the weight of the water-absorbing material before being added. Furthermore, examples of hydrophilic substances that maintain the above-mentioned contact angle at an acute angle by coating on the film include sorbitan fatty acid ester, (poly)glycerin fatty acid ester, polyethylene glycol monostearate, and fatty acid jetanolamide, which are known as antifog agents. , stearic acid monoglyceride, sorbitan monostearate, solpitan monooleate, polyhydric alcohol fatty acid ester, glycerin monooleate, polyoxyethylene glycerin monostearate, polyoxyethylene sorbitan mo/oleate, solpitan monolaurate, sorbitan monobel mitate, bentaerythritol fatty acid ester, etc. are used, and in addition, various surfactants known as hydrophilic substances and polyoxyethylene alkyl ethers and polyoxyethylene alkyl ethers, which have hydrophilic properties and are used as antistatic agents, are used. Enol, polyoxyethylene alkylamiso, polyoxyethylene alkylamiso 0
fatty acid polyethylene glycol ester, fatty acid sorbitan ester, polyoxyethylene fatty acid sorbitan ester, fatty acid glycerin ester, alkyl polyethyleneimine, fatty acid amine salt, alkyl phosphate ester salt, polyoxyethylene alkyl phosphate ester salt,
There are alkyl sulfate ester salts, polyoxyethylene alkyl sulfate ester salts, alkyl amine salts, alkyl quaternary ammonium salts, alkylimidazoline derivatives, alkyl betaines, alkylimidazoline derivatives, N-0 alkyl 8-alanine, etc. , various higher fatty acid glycerides, fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, montanic acid, oleic acid, linoleic acid, behenic acid, etc., and these mono-, di-, or triglycerides are used. It will be done.

In addition, phosphorus compounds include triptyl phosphate, triisooctyl phosphate, tribenzyl phosphate, triphenyl phosphate, phenyldecyl phosphate, diphenyl isodecyl phosphate, triphenyl phosphate, and sulfonic acid group-containing As the compound, benzenesulfonic acid, valatoluenesulfonic acid, salts or hydrates thereof, etc. can be used, but the compound is not limited to these, and other compounds may also be used.
Any material may be used as long as it can form an acute angle, that is, a contact angle between 0 and 9 degrees, with respect to the aqueous droplet adhering to the surface of the coating. Furthermore, it is preferable that the value be as close to 00 as possible. The present invention will be explained in more detail below based on Examples.

Example 1 Vinylon fiber canvas based on the following structure Density: 2 Grain weight: 360 / This was used as a base fabric, and after blanching and drying, processing liquid having the following composition: 1 PVC resin 8 parts by weight of butyl benzyl phthalate Paper Epoxidized Soybean oil 7″ Calcium carbonate
20 Cadmium. Barium stabilizer 3 Pigment 8 Toluene (solvent) 130 After soaking in 130, squeeze between rollers, dry at 90qo for 1 minute, and further 160q
The sample was heat-treated for 1 minute at 300°C.

Again, 3 parts of a mixture of 20% sorbitan laurate, 30% sorbitan stearate, 50% sorbitan stearate EO adduct, which is a hydrophilic substance, is mixed into the working fluid 1 to prepare the working fluid 2. After soaking in processing liquid 2, squeeze between rollers and dry for 1 minute at 90qo, then dry at 160℃ for 1
Sample 1 was obtained by heat treatment for 1 minute.

Next, for comparison, sample 2 was obtained by soaking, drying, and heat-treating in machining fluid 1 again instead of machining fluid 2. The wettability index as a convenient method for determining the water resistance, vertical water degree, and contact angle of both is JIS-L-10 Moth-19775.1.1A water resistance and JIS-L-10 Ship-197752, respectively. The results of the test are shown in the table below in accordance with water content (spray test) and JIS-K-167 Spot-1 1977 (wetting index).

As mentioned above, both samples 1 and 2 have sufficient water pressure resistance, and sample 2 (conventional product) has high water repellency but is difficult to stagnate.
Sample 1 according to the present invention has a small aqueous property and has the property of being easily colored.

Therefore, the waterproof fabric according to the present invention has a small contact angle, which in this example is 200 or less. A simple sheet house of 2 skins x 2 x 2 kites was made from each of Samples 1 and 2 obtained in this way, and the interior of the house was maintained at 40°C with an 80% R mark, and the minimum outside temperature was 5°C. It was left outdoors overnight.

As a result, a large amount of water droplets were observed to fall on the floor of the house made from sample 2, but in the house of sample 1, no water droplets were observed to fall, and there were many water droplets on the board surface. No formation was observed. In addition, when this house was left outdoors for one year, it was found that although the house of sample 2 initially repelled rainwater well and had apparently favorable waterproof properties, its outer surface gradually became contaminated and rainwater continued to be unevenly distributed. It became so.

On the other hand, the house of sample 1 has been cleaned evenly and well during rainfall from the beginning, and even after a year, there is almost no dirt visible, and the water pressure resistance has not changed in any case, and there is no leakage of rainwater. There wasn't. Furthermore, since both processing fluids 1 and 2 used the same basic resin, the interface between the two processing fluids was in close contact with each other, and the surface coating was strong and highly durable. Example
2 Processing liquid of the same composition as in Example 1: 1/Iparon #20 (Dupont) 10 parts by weight of diluent ■ Tribasic lead maleate (Trimar: Kawaguchi Chemical Co., Ltd.)
Fly sea bream ■Diventaethylenethiulum tetrasulfide (Axel BF: Kawa Roy C Gaku KK)
1 part by weight Clay resin 1 3 Filler (clay) 20 Pigment
18 Toluene (diluted to 40 centipoise 50
After immersing in the processing liquid, it was dried for 2 minutes at 14 pi○, and then a water-absorbing substance mainly composed of vinyl alcohol noacrylate copolymer (super water-absorbing polymer HYD) was added to the processing liquid.
Processing liquid 2 in which 3 parts by weight of ROGEL-S (Sumitomo Chemical KK) was uniformly dispersed was applied and dried at 140°C for 4 minutes to obtain a waterproof fabric with a contact angle of about 2y according to the present invention. .

As a comparative example, waterproof fabrics that do not contain the above-mentioned superabsorbent polymer were created, and simple houses similar to those in Example 1 were created for each of them, and tests were conducted under the same conditions. On the other hand, there was almost no water droplet generation and no contamination was observed over time.However, using only machining fluid 1 without applying machining fluid 2, it initially had the advantage of good drainage, but soon became seriously contaminated. Moreover, the rate of water droplet production due to internal water droplets was high from the beginning.

Claims (1)

[Scope of Claims] 1. In a fibrous waterproof fabric formed by forming a coating of synthetic resin, rubber, etc. on one or both sides of a fibrous base fabric, the contact angle for aqueous droplets on at least one surface of the coating is A fibrous waterproof fabric characterized in that a water-absorbing substance or a hydrophilic substance having hydrophilic properties is applied to the surface so as to form an acute angle. 2. The fibrous waterproof fabric according to claim 1, wherein the water-absorbing substance is a water-absorbing substance whose main component is a vinyl alcohol/acrylate copolymer. 3. The fibrous waterproof fabric according to claim 1, wherein the hydrophilic substance is a mixture of sorbitan laurate, sorbitan stearate, and sorbitan stearate EO adduct.