KR0160467B1 - Method for manufacturing artificial leather - Google Patents

Abstract

The present invention is a method of manufacturing artificial leather, the final single yarn fineness of 0.3 denier or less microfiber filament is produced by the organic diisocyanate, polytetramethylene glycol, nitrogen atom-free low molecular diol, nitrogen atom-containing low molecular diol, polymer triol and dimethylform It is a manufacturing method of artificial leather characterized by performing a series of post-processing treatments such as buffing, dyeing using dye dye, buffing, soaping after impregnating polyurethane manufactured using amide. Provides artificial leather which is useful for various miscellaneous materials.

Description

Artificial leather manufacturing method

The present invention relates to a method for producing artificial leather excellent in hydrolysis resistance and dyeing.

More specifically, microfiber bubbles are impregnated with polyurethane prepared using organic diisocyanate, polytetramethylene glycol, low molecular weight diol containing no nitrogen atom, low molecular weight diol containing nitrogen atom, high molecular triol and dimethylformamide, and buffing. The present invention relates to a method for producing artificial leather having excellent hydrolysis resistance and dyeing property by performing post-processing treatment such as dyeing.

Artificial leather is manufactured through various post-processing such as dyeing and buffing after filling a polymeric elastomer with a coating fabric. Various researches have been attempted to solve the problem because of the great difficulty in dyeing the filled polymeric elastomer.

Polyurethane is mainly used as a polymer elastic body used in the manufacture of artificial leather. Polyurethane prepared by a general method is not easily dyed and has a problem of poor hydrolysis resistance because it is vulnerable to alkali.

Methods for improving the dyeability of polyurethane include 1) introducing a tertiary nitrogen atom into the polyurethane polymer chain (Japanese Patent Publication No. 62-23097), 2) salts of organic or inorganic acids with tertiary amines. (3) Introduced into the polyurethane polymer chain (Japanese Patent Publication No. 75-17520), 3) A method of introducing a tertiary or quaternary nitrogen atom into the terminal of the polyurethane polymer chain (Japanese Patent Publication No. 69-16386) And the like have been proposed. However, Method 1) and 2) are easy to form gel during the reaction, and Method 3) has a disadvantage in that it is difficult to control the amount of nitrogen atoms introduced and the elasticity is poor.

In addition, a method of imparting a color by coloring the polyurethane with the pigment has been attempted, but there was a problem that the dye fastness is weak.

Therefore, the object of the present invention was devised to solve such a conventional problem, and excellent dyeing characteristics, characterized in that the specially formulated polyurethane resin is impregnated in the coating target bubble and performing post-treatment such as dyeing, buffing. It is to provide a method for producing artificial leather capable of expressing the main color and excellent fastness.

In the present invention, organic diisocyanate (A), polymer diol (B), low molecular diol (C) containing no nitrogen atom, low molecular diol (D) containing nitrogen atom, high molecular triol (E) and organic solvent ( It is characterized by using a polyurethane prepared, including F).

As the bubble to be coated in the present invention, all bubbles used in general artificial leather can be manufactured, but in order to manufacture artificial leather having excellent flexibility, the final single yarn fineness is made of microfibers having 0.3 denier or less, woven fabric, tricot paper, and nonwoven fabric. Etc. are suitable, and nonwoven fabrics are most preferred because of the excellent strength of the final artificial leather.

Examples of such nonwoven fabrics include needle-punched nonwoven fabrics having a density of 0.20 g / cm 3 or more of a composite fiber composed of 2-6 denier fiber-forming components and soluble components. As a polymer elastic body impregnating such a composite fiber nonwoven sheet, the polyurethanes characteristically used in the present invention are obtained by mixing components (A) to (E) with an organic solvent (F) as described above. As the organic diisocyanate (A), it is preferable to use 3 to 9% by weight of one selected from 4,4'-diphenylmethane diisocyanate, 1-6-hexamethylene diisocyanate and isophorone diisocyanate. As the diol (B) component, it is preferable to use an ether-based diol, but selectively use 10 to 30% by weight of polytetramethylene glycol having a molecular weight of 1,500 to 2,000, and the nitrogen-free low molecular diol (C) component It is preferable to use 1,6-hexanediol at 0.5 to 2.5% by weight, and as the nitrogen atom-containing low molecular diol (D) component, N-methyldiethanolamine is contained in 0.05 to 0.35. It is preferable to use in%, the polymer triol (E) component is preferably 0.5 to 2.0% by weight of polypropylene triol, the dimethyl formamide is preferably used as the organic solvent (F). .

In the production of the polyurethane of the present invention, in particular, the nitrogen atom-containing low molecular diol (D) is two or more carbons present in the chain directly connecting two hydroxy groups, and one or two of the three groups linked to the nitrogen atom is a methyl group. It is preferable to use N-butyl diethanolami, 3-pyridio-1,2-propanediol, 3-dimethylamino-1,2-propanediol and the like as the low molecular weight diol of such a structure. It is good to select N-methyldiethanolamine which is excellent in terms.

In addition, N-methyldiethanolamine is preferably used at 0.05 to 0.35% by weight as described above with respect to the entire composition, since 0.05% by weight or less does not have an effect of improving dyeing property, and 0.35% or more by weight reduces elasticity. As a method of polymerizing a polyurethane from the above-mentioned components (A)-(F) in this invention, organic diisocyanate (A), high molecular diol (B), low molecular diol (C, D), and high molecular triol (E) are initial stages. It is preferable to use the one-shot method which adds all to the process and advances reaction.

In the case of using a prepolymer method in which an organic diisocyanate (A) and a polymer diol (B) are reacted first, and then a prepolymer produced is reacted again with a low molecular diol (C, D) and a residual organic diisocyanate (A), a one-shot method. Dyeability and elasticity is lower than when reacted with. In addition, it is preferable to keep the temperature at 60 ° C to 90 ° C when the reaction proceeds. If this occurs, the reaction does not proceed sufficiently or the physical properties of the raw material are deteriorated.

Polyurethane prepared by the above method has the advantage of being capable of deep color expression with excellent dyeability while having hydrolysis resistance and softness of a level suitable for artificial leather production.

The leather-impregnated sheet impregnated with the polyurethane is buffed with 240-320 mesh sandpaper and dyed using a dye dye in a liquid dyeing machine, followed by post-processing buffing with sandpaper of 320-400 mesh.

The sheet thus prepared is soaped in a liquid dyeing machine, and then subjected to Momi processing and surface finishing, thereby obtaining artificial leather having excellent dyeing degree, which is soft and excellent in dyeing. The artificial leather manufactured in this way can be used for high-quality medical and various miscellaneous materials because of its deep dyeing and excellent dyeing fastness because it uses post-processing polyurethane using excellent dyeing property, and it has excellent hydrolysis resistance and softness. It can be used as a material for shoe uppers.

Example 1

The polyester sea component copolymerized with 4 mole% 5 sodium sulfoisophthalic acid and 6 nylon degree components of terephthalic acid was spun at a combined 36 / filament ratio of 35:65, and then the number of crimps was 16 / inch, 3 denier, and 51 mm. Got staple fiber.

The staple fiber was carded and cross-wrapped in a conventional manner, and then needle punched to produce a nonwoven fabric having a non-directional thickness of 1.4 mm and an apparent density of 0.23 g / cm 3 with a weight of 320 g / m 2.

Leather composite sheets were prepared by impregnating the composite fiber nonwoven sheet with 100% modulus of 24 kg / cm 2 polyurethane.

6.4 wt% of 4,4'-diphenylmethane isocyanate, 20.8 wt% of polytetra methylene glycol having a molecular weight of 2000, 1.5 wt% of 1,6-hexanediol of 6 carbons, 0.2 wt% of N-methyldiethanolamine % And 1.1% by weight of polypropylenetriol having a molecular weight of 3000 were used as a raw material and 70% by weight of 4,4'-dimethylformamide as a solvent was prepared by the one-shot method.

The sheet was wet-coagulated in a coagulation bath consisting of 90 parts of water and 10 parts of DMF, washed with hot water at 70 ° C., dried, and completely dried after removing the copolyester in a bath of 2% concentration of caustic soda and 95 ° C. in hot water. The dried sheet was dried through a high pressure water flow zone having a nozzle diameter of 0.2 mm and a water pressure of 60 kg / cm 2, then buffed with 320 mesh sandpaper, dyed with an alloy dye in a liquid dyeing machine, and then post-treated with 400 mesh sand paper. The leather sheet was produced. The sheet thus prepared was soaped in a liquid dyeing machine, and then artificial leather was prepared by processing and surface finishing.

Example 2

Synthetic fibers were manufactured in the same manner as in Example 1 by using a staple fiber having a frequency of 19 fibers / filament and using 2.5 denier, 45 mm, and 22 crimp / inch.

Comparative Example 1

Except for using a general polyurethane prepared by impregnating polyurethane, 6.4 parts by weight of 4,4'-diphenyl methane isocyanate, 20.8 parts by weight of ethylene glycol, and 70 parts by weight of 4,4'-dimethylformamide. It proceeded similarly to Example 1.

Comparative Example 2

In preparing the impregnated polyurethane, except that the organic diisoyanate (A) and the polymer diol (B) are first reacted, and then the prepolymer produced is reacted with the low molecular diol (C, D) to prepare a prepolymer method. Proceed as in the following.

Comparative Example 3

The procedure was the same as in Example 1 except that 1.3% by weight of the nitrogen-free low molecular diol (6 carbon 6,6-hexanediol) and 0.4% of the nitrogen atom-containing low molecular diol (N-methyldiethanolamine) were used.

Table 1 shows the characteristics of the artificial leather produced by the above Examples and Comparative Examples for comparison.

Claims (3)

Bubbles made of microfibers having a final single yarn fineness of 0.3 denier or less were 3 to 9% by weight of diisocyanate, 10 to 30% by weight of polytetramethylene glycol, 0.5 to 2.5% by weight of 1,6-hexanediol, and N-methyldiethanolamine 0.05 To 0.35% by weight, 0.5 to 2.0% by weight of polypropylenetriol, and 60 to 90% by weight of dimethylformamide, and then impregnated with polyurethane, followed by buffing, dyeing using dye dyes, buffing, and post-treatment. Method of manufacturing artificial leather characterized in that. The method for producing artificial leather according to claim 1, wherein the bubble is a nonwoven fabric, a woven fabric, or a tricot paper. The polyurethane is a method of manufacturing artificial leather, characterized in that the one-shot method.