JPS58144177A - Production of moisture permeable water proof fabric - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a highly flexible, moisture-permeable waterproof fabric having a polyurethane coating.

In general, forming a polyurethane solution in a solvent and coagulating it in water to obtain a porous polyurethane film is well known as a normal hot film forming method.

However, when such a hot film forming method is used as a means to obtain a moisture-permeable waterproof fabric, coarse pores are formed inside the film by the normal coagulation process, and the porous structure is reduced in the drying process after the coagulation process. As a result, although waterproofness can be obtained, satisfactory moisture permeability cannot be ensured.

In addition, in order to maintain the porous structure of the polyurethane film, fillers such as common salt and water-soluble polymers are added to the polyurethane solvent tt.
The method of adding polyurethane to the fabric is well known, but when improving moisture permeability by such a method, the solvent solution of polyurethane easily penetrates into the fabric, especially in thin fabrics, and even the back side of the fabric. The disadvantage is that it has a hard texture.

The object of the present invention is to create a moisture-permeable waterproof fabric based on the porous structure retained in the polyurethane film (which has moisture permeability and has a flexible texture despite the presence of the polyurethane film in the fiber layer). The purpose is to provide a manufacturing method.

That is, the present invention applies a polyurethane solvent solution to a knitted fabric and coagulates it with water to produce a waterproof fabric with a polyurethane film.
lj-dissolvable water-soluble polymer #11 [impregnated into knitted fabric,
Apply polyurethane solvent S* to underarm fabric without drying.
After applying and permeating the water-soluble polymer solution impregnated layer.

A method for producing a moisture-permeable waterproof fabric comprising coagulation treatment with water.

The polyurethane used in the present invention is produced from a polyhydric hydroxyl compound having a hydroxyl group at the end, an organic diisocyanate, and a chain extender. Other polymers such as Jlonitrile may also be mixed.

Polyurethane solvents include N,N-dimethylformamide, dimethylsulfoxide, tetrahydrofuran, N,N
-, dimethylacedoide, etc. are used, but any material that dissolves polyurethane and is compatible with water may be used.

The water-soluble polymer used in the present invention includes:

For example, tf is a solvent-soluble poly9 urethane as mentioned above.
17 vinyl alcohol, hydroxyl alcohol, carboxymethyl cellulose.

Examples include, but are not limited to, carboxyvinylpolyi- and their rust conductors.

In the present invention, before applying a polyurethane solvent solution to a knitted fabric, a water-soluble polymer is added to a polyurethane solvent K0.
A knitted fabric is impregnated with a solution in which about 1 to 35 VT bags are dissolved by a dipping method, a padding method, a coating method, etc.

When impregnating the knitted fabric with the water-soluble polymer solution, it is preferable to impregnate the knitted fabric in a layer with as uniform a thickness as possible in order to uniformly form a porous polyurethane film.

The amount of impregnation into the knitted fabric is a polyurethane solvent solution.

Although it varies depending on the type of water-soluble polymer, it is preferable that the amount of water-soluble polymer is retained in 1 = 25 vtlj knitted fabrics.

If the amount of water-soluble polymer retained is too small, it will not be possible to prevent the porous structure from disappearing during the subsequent steps of forming the polyurethane film and during the drying process, and if it is too large, the formation of the polyurethane film will be unsatisfactory.

The knitted fabric impregnated with the water-soluble polymer S* is immediately transferred in a wet state to a coating process of a solvent solution of KvZ, Voliclet/, without drying.

The polyurethane solvent solution is applied to the impregnated surface of the knitted fabric impregnated with the water-soluble polymer solution using a roller, knife coater, spray gun, or the like.

The solvent l# solution of Volicleta Y usually has a polyurethane concentration of 5.
A solution of ~4Q is used, and it is necessary to sufficiently penetrate the water-soluble polymer St-impregnated layer of the fabric.

From the viewpoint of permeability, it is more preferable that the solvent used for the polyurethane solvent solution is the same as the solvent for the water-soluble polymer solution. :.

A coloring agent, lI water agent, etc. may be added as appropriate to the polyurethane solvent solution. In the present invention, by applying such a solvent solution of polyurethane, the polyurethane and the water-soluble polymer are mutually transferred within one fabric through the solvent of both solutions, and the polyurethane in a state where the water-soluble polymer is mixed penetrates. A layer is formed. After applying a solvent solution of polyurethane.

Coagulate with water using a conventional method. Alcohols may be added to the water used for coagulation.

After the coagulation process, it must be further washed with water and dried. This coagulation process removes the solvent and coagulates the polyurethane, and also removes the water-soluble polymer, but the coagulation of the polyurethane is performed before the removal of the water-soluble polymer, and is carried out in the presence of water-soluble polymers. Therefore, rapid coagulation does not occur,
A layered polyurethane film with a uniform and fine porous structure is formed within the fistula. The porous structure of this polyurethane film does not disappear even during the drying process (it is retained and moisture permeability is ensured).

In the present invention, the polyurethane coating is formed within the knitted fabric, but it may also be exposed on the surface of the knitted fabric to flatten the uneven surface of the fabric.

The moisture-permeable waterproof fabric of the present invention has excellent waterproofness, moisture permeability, and moderate air permeability, and has flexibility.
), Suho? /17e7t vj cold clothes, m*.

Applicable to work clothes, etc.

Hereinafter, the present invention will be explained with reference to Examples.
Commercially available polyvinyl alcohol (silicification degree 86.5-8
9. Omol 2 (polymerization degree 1,000 or less) dissolved in dimethyl sulfoxide is applied with a 20 weight s**t' knife coater as shown in Table 1, and then goes through a drying factory. (Polyester urethane elastomer-r-15 parts by weight was mixed with 85 parts by weight of dimethyl sulfoxide.
Using a knife coater, approximately 1501/ld (vat) of 111 [containing 1 KII] was coated on the base material coated and impregnated with the above-mentioned polyvinyl alcohol solution, and the mixture was left for 2 minutes. The resulting coated fabric was introduced into water IW1 and subjected to an inter-disposal treatment at 30°C for 30 minutes, followed by removal of water and polyvinyl alcohol in a hot water bath at 50°C for 30 minutes, followed by drying. Immerse the fluorine thread in a solution containing 2 parts by weight of water repellent and squeeze it with a mangle for 80 s.
After squeezing it uniformly, it was heat-treated at 150° C. for 30 seconds using a setter.

Note) The water pressure test was conducted according to J18 standard L-1092-1977 moisture permeability test - Z-0208-1976 (cup method) air permeability test and L-1098-1979 (Gurley method).

As is clear from Table 1, those without polyvinyl alcohol pretreatment had poor air permeability and a hard texture.

On the other hand, the material obtained according to the present invention was flexible, and had excellent air permeability and water resistance not found in the past.

Example 2 The same textured yarn fabric used in Example 1 was impregnated with a 15 weight solution of commercially available hydroxyethyl cellulose (211 aqueous solution, viscosity 300 centimeters/thickness at 020°C) dissolved in dimethylformamide, and molded into a mangle. After reducing the solid content to 10% by weight, immediately add 18' parts by weight of the polyurethane/elastomer and 0.5 parts by weight of the fluorine water repellent to 81.5 parts by weight of dimethylformamide.
Approximately 12,017 ml (W@t) of the scaled solution was applied using a knife coater onto the substrate impregnated with the hydroxyethyl cellulose solution, and left for 1 minute. Next, dimethylformamide was introduced into an aqueous solution containing 10% by weight and treated at 30°C for 5 minutes to coagulate, and the solvent was removed and hydroxyethyl cellulose was removed in a hot water bath at 5 ()°C for 30 minutes. i. A coated fabric was obtained by drying in a hot air dryer at 120°C for 10 minutes.As a result, the fabric had a water pressure resistance of 1300+ and a moisture permeability of 2850 P/wl.
A waterproof and moisture-permeable fabric with a flexible texture and an air permeability of 120 seconds/100 #A was obtained.

Claims (1)

[Claims] Applying a polyurethane solvent solution to a knitted fabric Ik, IIIL. Waterproof fabric with polyurethane film coagulated with water
When making Il, in advance polyurethane solvent K11jl
Impregnate the knitted fabric with a water-soluble polymer solution and do not dry it (after applying a solvent solution of NK Polycretan for armpit fabric and permeating it into the water-soluble polymer solution impregnated layer, apply it with water. A method for producing a moisture-permeable waterproof fabric characterized by coagulation treatment.