JPS61160480A - Production of coating cloth - 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 [Industrial Field of Application] The present invention relates to a method for producing a coated fabric with excellent water resistance and moisture permeability.

[Prior Art] In recent years, coated fabrics have been actively developed and used in raincoats, sports clothing, casual coats, mountaineering equipment,
Used for windbreakers, fishing wear, rider suits, marine wear, etc.

Conventionally, acrylic esters, polyamides, vinyl chloride, chloroprene, Hypalon, natural rubber, silicone resins, fluororesins, and the like have been used as coating resins in this technique.

However, these resins usually form a coating film by themselves, and are currently unsatisfactory in terms of texture and physical properties.

However, since polyurethane achieves relatively good film formation, it has been primarily applied in coatings. Among such polyurethane films, wet coagulated polyurethane forms a porous film and is widely used in fields requiring water resistance and moisture permeability. However, even such a wet coagulation polyurethane film has a strong stuffy feeling, and a film with excellent moisture permeability is required. The reality is that when moisture permeability is improved in order to improve the stuffy feeling, water resistance and film properties deteriorate, and no product has been obtained that satisfies both performances.

[Problems to be Solved by the Invention] The present invention provides a method for simultaneously imparting high levels of both water resistance and moisture permeability to a fabric.

[Means for Solving the Problems] A method for producing a coated fabric, which comprises coating a fabric with a mixture of a polyurethane solution containing an acrylic compound and an inorganic or organic fine powder, and then performing wet coagulation.

The present invention forms a characteristic film in which the presence of a specific compound in polyurethane improves moisture permeability without degrading the film's physical properties or water resistance. Fine powder is interposed in the micropores inside the coating, resulting in high water resistance. That is, it was discovered that a film can be formed that satisfies both properties at a high level, and the present invention was achieved.

The fabrics used in the present invention include synthetic fibers such as polyamide, polyester, and polyacrylic, and modified fibers thereof, natural fibers such as wool, silk, cotton, and linen, and semi-synthetic fibers such as acetate and rayon, or mixtures thereof. A sheet-like material made of fibers, such as knitted fabrics, non-woven fabrics, etc.

The acrylic compounds referred to in the present invention include those seven
It also contains a single compound or a mixture of two or more of compounds selected from polymers and copolymers.

To give specific examples of 7-termers, for example, acrylic acid, α
Examples include alkyl-substituted acrylic acids such as methacrylic acid and ethacrylic acid, and salts thereof. Also,
Examples of acrylic ester compounds include methyl acrylate, butyl methacrylate, amyl acrylate, n-
Acrylic acid such as decyl methacrylate and benzyl acrylate, alcohol esters of methacrylic acid, glycol esters such as β-hydroxyethyl acrylate, β-hydroxyisopropyl acrylate, glycidyl acrylate, alkylene glycol diacrylate, aminoalkyl acrylate, 2-cyanoethyl acrylate, Methyl chloride salts of esters of alcohols having functional groups such as alkoxycarbonyl acrylate, pentachlorophenylacrylate, and 7-mino group-containing acrylic acid compounds such as dimethylaminoethyl acrylate; ammonium salts such as 3-acryloxy-2-hydroxypropyltrimethylammonium chloride; Examples include derivatives thereof.

Among these compounds, those that are easily soluble in both water and dimethylformamide are preferred. In other words, such a compound has good stability in a polyurethane solution, and when coagulated with water, extraction into the 1st solid bath is promoted, resulting in a more porous structure, which has the effect of greatly increasing the porosity. Demonstrate.

Preferred examples of such compounds include methyl chloride salt of dimethylaminoalkyl acrylate (methacrylate) as a monomer, and polyacrylic acid (methacrylic acid) and its salts as a polymer.

The inorganic or organic fine powder remains in the internal pores of the microporous membrane and has the effect of blocking the communicating pores during waterproofing and increasing the waterproofing without reducing the moisture permeability. Further, the fine powder has an average particle size of 0.005 to 40μ, more preferably 0.1 to 40μ.
Must be 20μ. If the size is too small, secondary agglomeration will occur, resulting in insufficient uniform molding, resulting in decreased waterproofness. If it is too large, the strength of the film will decrease, resulting in poor waterproofness and durability. Examples of inorganic fine powder include synthetic silica, fine silicic acid, diatomaceous earth, quartz powder, etc. made by fume method or wet method.
Siliceous sandstone, silicic acid, calcium silicate, zirconium silicate,
Examples include silicates such as clay, alumina, calcium carbonate, magnesium carbonate, kaolin clay, fine powder talc, titanium oxide, iron oxide, and carbon black. Examples of organic fine powders include powdered polymer compounds such as polyester, polyamide, polyacrylonitrile, polyurethane, polyacrylic resin, and fluorine resin, and organic pigments such as quinacrid red, polyazo and monoazo red, Disazo yellow, cyanine green,
Examples include cyanine blue.

The above-mentioned fine powders can be used alone or in combination of two or more.

The polyurethane solution used in the present invention is a solution whose main component is polyurethane containing the above-mentioned acrylic compound and other additives. used as

The mixing ratio of polyurethane, acrylic compound, and inorganic or organic fine powder is as follows.

The amount of the acrylic compound is 0.5 to 50 parts by weight, more preferably 3 to 30 parts by weight, based on 100 parts by weight of polyurethane. If it is too low, the moisture permeability will be low, and if it is too high, the strength of the film will decrease, resulting in low waterproofness. The inorganic or organic fine powder is 0.1 to 30 parts by weight, more preferably 2 to 30 parts by weight.
It is a 15-storey room. If the amount is too low, the formation of uniform micropores will be insufficient, resulting in decreased waterproofness, while if the amount is too high, the film will become brittle.

The polyurethane of the present invention is a reaction product containing a polymer diol, a diisocyanate, and a chain extender, and a polyester type is preferable as the polymer diol for the present invention. Among the polyester type polymer diols, diols such as polyalkylene adipate glycol, ie, polyethylene adipate glycol, polyethylene propylene adipate glycol, polyethylene butylene adipate glycol, polybutylene adipate glycol, and polyhexamethylene adipate glycol are preferred.

In the present invention, there are no restrictions on the diisocyanate and chain extender that are other components, but examples of the diincyanate include common isocyanates for polyurethane such as 4,4'-diphenylmethane diincyanate, tolylene diisocyanate, and xylene diisocyanate. Classes apply.

Among these, 4,4'-diphenylmethane diisocyanate is preferred for the purposes of the present invention. Further, chain extenders include diols and diamines, and diol-based chain extenders are particularly preferred as chain extenders of the present invention, and glycols such as ethylene glycol, 1,4-butylene glycol, and hexamethylene glycol are preferred. can be mentioned.

Additives for such polyurethane solutions are agents such as auxiliaries added as necessary for the purpose of improving membrane properties, such as hydrophilic anionic interfaces added to improve membrane surface smoothness and curling. Examples include activators, hydrophobic nonionic surfactants, silicon compounds, and fluorine compounds.

Any water-soluble solvent can be used as the medium for the polyurethane solution, but dimethylformamide is particularly preferred.

The concentration of such a polyurethane solution is 5 to 40% by weight, preferably 10 to 25% by weight. The viscosity of such a solution is selected to be 500 to 50° ooocps, preferably 10.000 to 30° ooocps, from the viewpoint of film forming property, moisture permeability, and film physical properties.

There are no limitations on the method of coating the fabric with the solution. For example, a coating method such as a floating knife coater, a knife over roll coater, a reverse roll coater, a roll doctor coater, a gravure roll coater, a kiss roll coater, a nip roll coater, or a one-way spray method or a lamination method bonding method can be applied.

After such coating, the polyurethane is wet coagulated, and the coagulation bath used is water or an aqueous solution of water and dimethylformamide at a temperature of 20-40"C.

After the coagulation bath treatment, the membrane is thoroughly washed with hot water to remove dimethylformamide from the membrane, and then dried and heat treated.

In the present invention, water repellent finishing or calendering can be applied after the solvent is removed. In particular, the water repellent finish has features that greatly enhance the effects of the present invention and its durability. Such water repellents include fluorine-based and silicone-based ones, and fluorine-based water repellents are particularly effective in improving water pressure resistance.

[Example] Example 1.2.3 After dyeing nylon 6 taffeta with a warp density of 120 threads/inch and a weft density of 90 threads/inch with a warp yarn of 70 denier 12 filaments and a weft yarn of 70 denier 24 filaments using a conventional method, fluorine was dyed. A treatment solution containing water repellent 5C1/I was applied to a pad, and after drying, heat treatment was performed at 170'C for 1 minute.

Next, as shown in Table 1, each coating agent was applied uniformly using a floating knife coater, and immediately immersed in an aqueous solution containing 10% dimethylformamide.
Solidification was achieved by residence at 30'C for 5 minutes. This coated fabric was washed with hot water at 80°C for 30 minutes, dried at 100°C, and then heat-treated at 140°C to obtain this product.

The functionality of the above coated fabrics was evaluated and Table 1
I got the result. The thickness of each film is approximately 30μ.
Met. Water resistance and moisture permeability are each JIS L1
079, measured according to JIS Z0208.

This shows that the coated fabric of the present invention has excellent water resistance and moisture permeability.

Comparative Example 1 As shown in Table 1, when coating was performed without mixing the compounded compound or fine powder, the moisture permeability was extremely low.

Table 1 [Effects of the Invention] The effects of the coated fabric obtained by the present invention are as follows.

(1) Excellent water resistance and moisture permeability.

(2) Good stain resistance and no back contamination during dry cleaning.

(3) Good light resistance.

Claims (1)

[Claims] A method for producing a coated fabric, which comprises coating a fabric with a mixture of a polyurethane solution containing an acrylic compound and an inorganic or organic fine powder, and then wet-coagulating the fabric.