JPH0350031B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing deep dyeable artificial leather.

[Conventional technology] Conventional techniques for imparting dark color effects include creating microvoids on the fiber surface of the order of several microns to absorb light of a specific wavelength, or applying special polymers with different refractive indexes to the fiber surface. Coating methods are known.

However, the method of modifying the fiber surface cannot fully utilize the fiber strength of the polymer, resulting in a decrease in product strength, and the method of coating the fiber surface with a special polymer is
For artificial leather, where texture and touch are important,
It is difficult to impart a deep color effect to a sufficient extent, and methods for improving color development using copolymer polymers result in a decrease in fiber strength and are not practical. In other words, when trying to take advantage of color development, other properties required of artificial leather had to be sacrificed.

On the other hand, the present inventors responded to these demands by
Japanese Patent Publication No. 57-42981 has already provided a method for producing artificial leather that uses copolymerized polyester, prevents a decrease in the fiber strength of ultrafine fibers, and has good color development, texture, and touch. However, this artificial leather originally did not fully utilize the coloring properties of the polymer, and was not necessarily a satisfactory artificial leather.

[Problems to be Solved by the Invention] The present inventors have conducted intensive studies on a method for producing artificial leather that can be dyed deeply without the above-mentioned drawbacks, and have discovered the present invention.

[Means for Solving the Problems] That is, the present invention impregnates a nonwoven fabric or a woven or knitted fabric using cationic dyeable fibers with a binder dissolved in a solvent having an affinity for water, and wet-coagulates the coagulated fabric. The present invention relates to a method for producing artificial leather, which comprises adding a sequestering agent to a liquid or binder solution and then coagulating it.

The nonwoven fabric or woven or knitted fabric of the present invention has a fiber made of a cationic dye-dyeable polymer as a base material, and is impregnated with a binder dissolved in a water-friendly solvent such as dimethyl formamide (hereinafter abbreviated as DMF). During wet coagulation, the wetting of the fibers by the solvent prevents metal ions in the coagulation solution from reducing the dyeing capacity of the fibers;
This method effectively utilizes the dye adsorption rate to provide dark-colored artificial leather.

As the fiber constituting the base material of the present invention, it is necessary to use cationic dye-dyeable polyester or cationic dye-dyable polyamide. That is, in polymers that are not dyeable with cationic dyes, disperse dyeable, or acidic dyes, although they are swollen by DMF or the like, they are not affected by metal ions in the coagulation liquid.

In order to obtain artificial leather with excellent texture and touch, it is preferable to use fine fibers of 0.9d or less.
There are no particular limitations on the manufacturing method. In general, in terms of reinforcing the strength of fine fibers, and since it is not always easy to directly manufacture fine fibers, multi-component core-sheath composite fibers such as sea-island type composite fibers and mixed spun fibers are first manufactured, and then mainly non-woven fabrics and woven fabrics are produced. After knitting, it is usually subjected to ultra-fine treatment.

A preferred example of a combination of core-sheath type island components is 5-
Sodium sulfoisophthalate copolymerized polyester and polyethylene terethalate, or polybutylene terephthalate, or nylon 6,
A combination of 66, sodium sulfobenzoic acid copolymerized nylon, polyethylene terephthalate, polybutylene terephthalate, or nylon 6,66 is preferable for improving the strength of products using fine fibers, but depending on the purpose and application. Depending on the situation, 5-sodium sulfoisophthalate copolymerized polyester alone or sodium sulfobenzoic acid copolymerized nylon alone may be used.

On the other hand, suitable examples of the sea component include polystyrene, polyethylene, etc., and there are no particular limitations as long as the polymer uses a different solvent from the island component polymer and can be spun and manufactured.

Nonwoven fabrics or woven or knitted fabrics can be produced using known means, and are not particularly limited.

From the viewpoint of the texture, surface quality, touch, drapability, etc. of the product, shrinkage or gluing of the nonwoven fabric or woven or knitted fabric is preferably performed before impregnation with the binder solvent, but it is not necessarily necessary in the present invention. do not have. Processing can be done depending on the purpose and use of the target product.

The ultra-fine treatment may be any treatment as long as it dissolves the sea component polymer used but does not dissolve the island component polymer. Further, this ultrafine treatment may be performed before impregnation with the binder solution or after impregnation and solidification.

In addition to the above-mentioned DMF, dimethylacetamide, diethylformamide, dimethylsulfoxide, hexamethylphosphoramide, and the like are used as the solvent having an affinity for water in the present invention.

The coagulation method of the present invention is a method in which a base material impregnated with a binder solution is immersed in coagulating water in which a sequestering agent is dissolved, and solidified, or a method in which a base material is soaked in a binder solution containing a sequestering agent added to a binder solvent. This method involves impregnation, then immersion in coagulation water, and coagulation.

Industrial water is generally used as the coagulating water. This water contains metal ions such as calcium ions, magnesium ions, zinc ions, and iron ions. These metal ions tend to reduce the dyeing capacity in the fiber when the fiber surface is exposed to a high concentration of solvent and swells due to binder solution impregnation, and no matter how much metal ion sequestering agent is added during the dyeing process, The result is a product with low color development and a striking color difference. In other words, this problem could not be solved by the known technique of adding it in the conventional dyeing process. In the production of artificial leather, a sheet is impregnated with a solution-type binder and then coagulated in a wet process.
Adding it at the solidification stage of the present invention is an important technique for improving color development.

The sequestering agent used in the present invention may be any compound that binds with metal ions in an aqueous solution to form a soluble complex salt and prevents metal ions from being precipitated by other reagents.
Examples include condensed phosphate, ethylenediaminetetraacetic acid, nitrilotriacetic acid, dihydroxyethylglycine, gluconic acid, citric acid, tartaric acid, and the like. More specifically, commercially available products such as "Krewatsu (manufactured by Teikoku Kagaku)", "Tetron (manufactured by Meisei Kagaku)", "Thierion (manufactured by Yamada)", and "Solbin (manufactured by Kamogawa Kagaku)" are used.

The amount of the metal ion sequestering agent added varies depending on the metal ion concentration in the water used for coagulation, but for industrial purified water, the effect of the present invention can be sufficiently obtained by adding 0.05 g/-5 g//. Even if more than this is added, the effect of the present invention will not be lost, but adding more than necessary will cause uneven area weight in the base material.
If there is any unevenness in thickness, unevenness in density will be promoted, and there will be no merit in terms of cost.

Examples are shown next, but the effectiveness of the present invention is not limited or the interpretation thereof is limited by these. Rather, it brings about the next application development.

[Examples] Example 1 A felt was made using a three-component core/sheath type polymeric mutual array fiber. Its composition and physical properties were as follows.

Island component (core component): 14.25 parts by weight of polyethylene terephthalate Island component (sheath component): 42.75 parts by weight of polyethylene terephthalate containing 5-sodium sulfoisophthalate units at 8.0 wt%/total acid component Sea component: 43 parts by weight Polystyrene fiber length and fineness: approx. 51mm x 3.8d Ken shrinkage: approx. 15 threads/2.54mm Felt creation: needle punching method basis weight 560
g/m ² The felt was placed in boiling water, shrunk, squeezed with a mangle and dried.

Next, polyvinyl alcohol (partially saponified product) was applied at a concentration of 12% by weight (approximately 43% by weight/weight of the island composite fiber), and washed with trichlorethylene for + minutes. Next, polyuthalene DMF with a concentration of 14% was applied in a liquid bath at 51% by weight based on the weight of the fiber, and then a metal in which two of the four hydrogen atoms in the COOH group of ethylenediaminetetraacetic acid (EDTA) were replaced with Na. Ion sequestering agent (EDTA, 2Na, 2H ₂ O, commercial product name "Krewatsut N", manufactured by Teikoku Chemical) for water purification
After immersing it in an aqueous solution containing 0.5 g/dissolved and coagulating it, the glue was removed, and it was washed with hot water and dried. Next, the obtained base material was sliced to about 1/2 in the thickness direction, and then buffed using a sandpaper buffing device.

Then, it was stained under the following conditions.

Dye bath: Astrozon Gold Yellow GL (cationic dye) 5.7%owf Kayacryl Red GRL (cationic dye) 2.2%owf Kayacryl Blue GRL (cationic dye)
10.6% owf Acetic acid 0.5g / Sodium acetate 0.2g / Bath ratio 1:50 Dyeing temperature and time 80℃, 20 minutes 100℃, 40 minutes Post-dyeing cleaning Latcol PSK (Meisei Chemical anionic surfactant cleaning agent) 2.0 g/bath ratio 1:50 Processing temperature/time 60°C/20 minutes hot/water washing For dyed products, the above-mentioned sequestrants (EDTA, 2Na, 2H ₂ O) are not added to the coagulation solution, and other Compared to products made under the same conditions, the texture and touch were similar, but the product was dark (black) and very clear.

Example 2 Using the same fiber as shown in Example 1, Example 1 up to the step of de-sea treatment with trichlorethylene
Using a base material treated under the same conditions as above, 0.5 g/(vs. DMF) of the same sequestering agent used in Example 1 was added to a 14% by weight polyurethane DMF solution.
The added amount is 49% by weight based on the fiber weight,
Next, it was immersed in an aqueous solution (purified water) to solidify, then the glue was removed, washed with hot water, and dried.

Next, the obtained base material was sliced to about 1/2 in the thickness direction, and then buffed using a sandpaper buffing device.

Next, it was dyed under the same conditions as in Example 1. This product contains a sequestering agent (EDTA/EDTA) in DMF.
Compared to products made without the addition of 2Na/2H ₂ O) and under the same conditions, the color was darker (black) and clearer, which was extremely superior. Moreover, it had the same level of color development as Example 1.

[Effect of the invention] According to the present invention, while maintaining high fiber strength,
It becomes possible to obtain artificial leather that is even and can be dyed deeply.

Claims (1)

[Claims] 1. When impregnating a non-woven fabric or woven or knitted fabric using cationic dyeable fibers with a binder dissolved in a solvent having an affinity for water and performing wet coagulation, a sequestering agent is added to the coagulation liquid or binder solution. A method for producing artificial leather capable of deep dyeing, characterized by adding the additive and then coagulating it.