JPH0660464B2 - Method for manufacturing high color superfine fiber structure - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for producing an ultrafine fiber structure having high color development.

(Prior art and its problems) In recent years, woven fabrics and nonwoven fabrics using ultrafine polyester fibers,
Artificial leather and brushed products are touted as high-end products.

However, products using such ultrafine fibers have extremely poor color development, and nonwoven fabrics such as artificial suede have drawbacks such as insufficient flexibility and drapeability.

Generally, it was a common opinion among those skilled in the art that ultrafine polyester fibers are difficult to perform deep color dyeing even when using a dyeing solution having an extremely high dye concentration as compared with ordinary fibers. The reason is that as the single yarn fineness decreases, the fiber surface area increases and the colored light is weakened by the scattering of white light, so even if a large amount of dye is used, the apparent color density reaches the limit (saturation). The solution was not resolved, and a method of using a carrier together at the time of dyeing was adopted, but a satisfactory level of dark color was not obtained. In this case, conversely, the carrier remains after the dyeing and the new defect that the various fastnesses are remarkably lowered is merely added.

It is easily expected that it will be more difficult to solve the problem that cannot be solved by the ultrafine fibers as described above, using the ultrafine fibers. From such a technical background, it is the actual situation that, after all, it was considered that there was practically no method for solving this problem.

On the other hand, for the purpose of softening the fibers and improving the color developability, various methods for reducing the weight of ordinary polyester fibers with alkali have been used. However, this method also did not usually need to be applied to ultrafine fibers of 0.5d or less, and it was considered that it was extremely difficult to reduce the amount of such ultrafine fibers. There is no such example.

(Object of the Invention) The inventors of the present invention have made earnest studies on imparting high color-forming property to such ultra-fine polyester fiber, and as a result, the ultra-fine fiber structure made of a specific polyester exhibits high color-forming property. That is, the present invention has been achieved and the present invention has been achieved.

The present invention can achieve flexibility in addition to high color development, and can provide an ultra-fine fiber structure of extremely dark texture and high darkness that cannot be achieved by the prior art. Is.

(Structure of the invention) An ultrafine fiber structure of 0.5d or less made of polyester containing 4 to 6 mol% of sulfonic acid groups is
A method for producing a highly chromophoric ultrafine fiber structure, which comprises treating with an aqueous solution having a pH of 11.0 to 13.5.

(Mechanism of Action of the Invention) The polyester containing 4 to 6 mol% of sulfonic acid groups in the present invention has a very low raw yarn strength and is considered to be a fiber that cannot be subjected to alkali treatment. After breaking this conventional idea and treating it under specific conditions, it was surprisingly clarified that the weight loss can be finely adjusted, and in particular, it is possible to achieve extremely high density dyeing even with ultrafine fibers. . Such a finding is not found in ordinary polyester fibers (regular polyester).

The polyester containing 4 to 6 mol% of such a sulfonic acid group is usually one obtained by copolymerizing polyethylene terephthalate or / and polybutylene terephthalate with a sulfonic acid group-containing monomer such as sodium isophthalate sulfonate in the above blending amount range. . Such a polyester may be a mixture or a composite of other polyesters or polymers such as polyamide as long as the effects of the present invention are not impaired.

The ultrafine fibers referred to in the present invention have a single yarn fineness of 0.5d or less, particularly preferably 0.3d or less.

The method for producing such a fiber is not limited, and may be one formed from a fiber structure such as a peelable conjugate fiber such as a polymer mutual array structure or a polymer blend structure, or a multi-component fiber, and Alternatively, it may be formed from fibers having a core-sheath structure.

The term “fiber structure” as used in the present invention means a yarn made of the polyester fiber, a knitted woven fabric, a non-woven fabric, an artificial leather, or a post-processed product of these, for example, a raised product, a pile product, a bore, or the like, further impregnated with a resin such as polyurethane. And so on. In particular, the present invention is most effective in the resin-impregnated fiber structure.

The present invention further provides such a fiber structure with a pH of 11.0 to 13.
Treat with aqueous solution of 5. The fiber structure of the present invention is extremely poor in resistance to acids and alkalis,
In an aqueous solution with a pH of over 13.5, alkali penetrates inside the fiber, causing a marked decrease in fiber strength.
If it is less than 1.0, the treatment effect is not exhibited unless it is treated at a high temperature for a long time, and if such treatment is carried out, the strength is lowered. In any case, it is impossible to control because the weakness is a big obstacle.

In the present invention, the treatment is carried out using the above specific aqueous solution under the conditions of less than 90 ° C, preferably 80 ° C or less, and particularly preferably 40 to 75 ° C.

When the temperature is 90 ° C. or higher, the strength of the fiber is remarkably reduced, and it is preferable to treat at a temperature as low as possible from the viewpoint of fiber strength. However, if the processing temperature is low, the processing speed becomes slow, and about 40 ° C. is preferable from the viewpoint of reasonable speed.

Such treatment allows weight loss within a limited range of 5-20% of the fiber.

The pH of the aqueous solution can be adjusted with ordinary alkaline agents, such as caustic soda, caustic potash, sodium carbonate,
Potassium carbonate, sodium bicarbonate, etc. are applied.

To this aqueous solution, an alkali-resistant agent, additive, treatment agent, etc., such as a penetrant, for example, a phosphoric acid ester compound or the like, or a paste agent as a concentration change inhibitor, for example, an acrylic acid amide compound, ether type modified starch, etc., is added. You may mix.

The ultrafine fiber structure thus obtained is washed if necessary,
To be washed with water.

When dyeing the ultrafine fiber structure of the present invention, a cationic dye is applied.

Such a cationic dye is generally composed of a salt consisting of a colorant cation having a static charge in the color-developing part and a colorless anion, and the colorant cation is mainly an onium group or a broadly defined amino group and a nitrogen-containing heterocyclic group. The dye salt is water-soluble and is dyed directly to the fiber, usually in the form of chloride, sulfate, alkyl sulfate, oxalate or salts thereof, but in some cases it may be in the form of zinc chloride double salt. Some have. Specific examples of such cationic dyes include dyes such as ketisine, triarylmethane, queketene, acridine, azine, oxazine, thiazine and cyanine.

Such dyes are neutral or weakly acidic dye baths, usually 80 to 1
10 ° C., preferably 90 to 105 ° C., 30 to 12
A treatment condition of 0 minutes, preferably 40 to 60 minutes, is applied.

The dye concentration in the dye bath in this case may be adjusted according to the desired dye concentration, but is usually 50% owf or less, preferably 0.01 to 30% owf.

(Effects of the Invention) The present invention provides an ultrafine fiber structure having an excellent high color-developing property as well as an extremely soft and tight texture.

A particular feature is the successful development of high color with polyester-based ultrafine fibers, which was considered difficult in the past.

The present invention will be further described below with reference to examples.

Example 1 and Comparative Example 1 5-sodium sulfoisophthalic acid 5.2 as an acid component
A suede-like artificial leather composed of 70% by weight of polyethylene terephthalate fiber having a single yarn fineness of 0.18 d and 30% by weight of polyurethane copolymerized with mol% has a pH of 13.1 and a pH of 1.
Using the 3.4 aqueous solution, 60 ° C each with a liquid dyeing machine
It was treated for 40 minutes and washed with water. The weight loss rate was calculated from the change in weight of the treated product.

The treated product was further dyed with a dyeing solution containing the following cationic dye.

The same dyeing was also performed on the untreated artificial leather.

Composition of dye liquor Diacryl Red GL-N 6.0% owf (cationic dye manufactured by Mitsubishi Kasei Co., Ltd.) Acetic acid 0.5 g / l Sodium acetate 0.1 g / l Dyeing conditions 100 ° C. with a bath ratio of 1:30 × 60 minutes.

The color developability (dyeing density) of the dyed product is shown by K / S obtained from the Kubelka-Munk function below. The darker the color, the higher the value.

K / S = [1-R] ² / 2R (where R is a reflectance having a value of 0 to 1) Next, as Comparative Example 1, the artificial polymer in which the fiber-constituting polymer is a polyethylene terephthalate homopolymer fiber After the same treatment as in Example 1 except that leather was used, pH was 13.6 and 13.8, and the temperature was 100 ° C.,
Dyeing was performed using the following dye liquor composition.

The same dyeing was performed on the untreated artificial leather of this comparative example.

Dye composition Kayalon P.P. Rubine BLS 10.0% owf acetic acid 0.45% owf sodium acetate 0.6% owf Dyeing conditions 120 ° C. × 60 minutes at a bath ratio of 1:30.

The results are shown in Table 1. It can be seen from Table 1 that the dyed product of Example 1 has a markedly improved color developability as compared with the untreated product, whereas the dye of Comparative Example 1 shows only a color developability close to that of the untreated product and does not improve the color developability. The specific fiber characteristics of the present invention are clearly demonstrated. Further, it can be seen that Example 1 has a remarkably high color developing property as compared with Comparative Example 1 and has an extremely soft texture.

Example 2, Example 3 5-sodium sulfoisophthalic acid 5.2 as the acid component
Single yarn fineness of 0.1 with a component ratio (core / sheath) of polyethylene terephthalate copolymerized with mol% as sheath component and polyethylene terephthalate homopolymer as core component of 20/80
Suede-like artificial leather consisting of 70% by weight of 8d core-sheath type composite fiber and 30% by weight of polyurethane is produced at various pH values of 60 ° C.
The aqueous solution (bath ratio 1:30) was used to adjust the treatment time so that the weight reduction rate was 10% (Example 2).

Table 2 shows the relationship between the weight loss rate of the fiber component and the strength reduction for each pH.

From Table 2, it can be seen that the treated pH has a small decrease in strength in the range of 11.0 to 13.5, and the strength decreases remarkably in the other pH regions.

Next, as Example 3, treatment was performed using the above-mentioned aqueous solution of pH 12 at each treatment temperature until the weight loss rate reached 10%.
Table 3 shows the relationship between the weight loss ratio of the fiber component and the tear strength with respect to the treatment temperature.

From Table 3, it can be seen that the reduction in strength becomes extremely large at a treatment temperature of 90 ° C or higher.

 ─────────────────────────────────────────────────── --- Continued from the front page (56) References JP-A-51-72615 (JP, A) JP-A-54-69965 (JP, A) JP-A-56-58067 (JP, A) JP-A-57- 61735 (JP, A) JP-B 50-40195 (JP, B1)

Claims (1)

[Claims] 1. An ultrafine fiber structure of 0.5d or less comprising a polyester containing 4 to 6 mol% of sulfonic acid groups,
A method for producing a highly chromophoric ultrafine fiber structure, which comprises treating with an aqueous solution having a pH of 11.0 to 13.5 at a temperature lower than 90 ° C.