JPH064934B2 - Method for processing pseudo-hema of cellulose fibers - Google Patents

Description

TECHNICAL FIELD The present invention relates to a processing method for imparting a hemp-like texture to cellulosic fibers.

(Prior Art) The pseudo-hemp processing for cellulosic fibers has been actively studied since various times and has been carried out by various methods. Conventionally, the pseudo-hemp processing methods that have been conventionally performed are roughly classified into a method using a finishing agent and a method using chemical modification.

As the former method, a method of impregnating a polyester resin, a urethane resin, an acrylic ester resin or the like and heat-treating is generally used. The methods using these synthetic resins are widely used because they are relatively easy to process, but they are poor in the texture effect as hemp tone, and most of them are only given hardness and have a sharpness peculiar to hemp. ， Almost no elasticity is given. In addition, some methods have also been carried out in which colloidal silica is used in combination to give a sharp feeling, but even in this case, the rubbing effect of the colloidal silica only slightly improves the feel, and it has a measurable feel. Is far from. These methods are also insufficient in terms of durability of feeling. Other methods using finishing agents include coagulation with formalin using casein or gelatin, and coagulation with sulfuric acid using viscose, but the processing method is complicated and the effect of feeling Since it is not enough, it is hardly implemented at present.

As the latter method of chemical modification, there is a method of using a concentrated solution of sulfuric acid or zinc chloride. In this method, cellulose is semi-dissolved and parchmented, and a very hard texture can be imparted. However, since the texture obtained by this method is significantly different from hemp-like texture, it is generally different from organdy processing. It is called and is distinguished from pseudo hemp processing. As another method by chemical modification, there is a low temperature mercerizing treatment method, which is a method of performing mercerizing treatment at a low temperature of 0 ° C to -10 ° C. In this case, treatment at low temperature increases the swelling property of cellulose, and the texture is harder than that at room temperature. From the aspect of texture, the texture is relatively close to that of hemp among conventional methods. Although the product can be obtained, the biggest drawback is that the durability of the texture is poor, and the texture is impaired after several washings.

(Problems to be Solved by the Invention) It is an object of the present invention to obtain a processing method for imparting a durable and very hemp-like texture to cellulosic fibers by improving the low temperature mercerizing method. Is.

(Means for Solving Problems) The present invention has the following configuration in order to achieve the above object.

That is, the gist of the present invention is to provide a pseudo linen processing method for cellulosic fibers, which comprises impregnating the cellulosic fibers with an alkaline solution, then performing a dry heat treatment, and then subjecting the fibers to a mercerization treatment at a low temperature. Is.

Hereinafter, the method of the present invention will be described in detail. The method of the present invention focuses on the texture of hemp tone obtained by the low temperature mercerizing treatment,
It was researched and developed with the aim of further enhancing its effect.

In the method of the present invention, in order to increase the sensitivity of the cellulosic fibers to high-concentration alkali, the surface of the fibers is converted into oxycellulose beforehand, and during the subsequent low-temperature mercerizing treatment, the alkali swelling property of the fibers is extremely increased to obtain a hemp-like texture. It is intended to give a feeling of hardness.

In the method of the present invention, first, the cellulosic fibers are impregnated with the alkaline solution, and then the dry heat treatment is performed.

The term “cellulosic fiber” as used in the present invention mainly means cotton, but the present invention can also be applied to cellulosic fibers other than cotton, that is, rayon, hemp and the like. Regarding hemp, the name hemp tone is not always correct, but it is included in the scope of application of the method of the present invention because the feeling of sharpness can be further emphasized. The fibers to be treated may be in the form of woven fabric or knitted fabric, and the method of the present invention can be applied in the form of yarn.

Alkali agents that can be used in the pretreatment of the present invention include sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogencarbonate, potassium hydrogencarbonate and the like. Anything can be used if it presents.
However, from an industrial point of view, it is most advantageous to use sodium hydroxide. An alkali solution is used to impregnate the cellulosic fibers with alkali, and in the case of a cloth, it is pressed and squeezed with a mangle or the like, and then subjected to dry heat treatment. The effect of the present invention is great when the concentration of the alkali used is in the range of 1% owf to 10% owf after the squeezing solution. Regarding the processing conditions for dry heat treatment, when using a bake machine in a continuous form such as cloth,
The treatment is performed at 130 to 180 ° C. for about 20 seconds to 5 minutes.

After performing the above processing, residual alkali is removed, and then mercerization processing is performed. For this mercerizing treatment, a well-known mercerizing processing method which is usually carried out on a cloth or yarn is applied. However, in the present invention, a low temperature mercerizing treatment, which has a large curing action, is effective for the purpose of sometimes giving a hemp-like texture. is there. The temperature of the low temperature mercerizing treatment may be 0 ° C. to −10 ° C., but the lower the temperature, the greater the hardening thereof, so the treatment at −5 ° C. to −10 ° C. is more appropriate. The above-mentioned low temperature mercerizing treatment is generally carried out as a hemp-like texture processing. However, in the method of the present invention, a pretreatment with an alkaline agent is carried out in advance, so that even if the mercerizing treatment is carried out at room temperature, the conventional low temperature mercerizing treatment is carried out. A hemp-like product that is harder and has a sharper feeling than the process of mercerizing only can be obtained. However, when combined with the low temperature mercerizing treatment, the hardness and sharpness of the texture are dramatically improved, and a durable, very linen-like texture can be obtained.

(Operation) As in the method of the present invention, by subjecting the cellulosic fibers to a heat-sensitive treatment with an alkaline agent in advance, the swelling action is increased in the subsequent mercerizing treatment, and a sharp feeling similar to hemp is obtained. The reason why the texture is obtained is not always clear, but the present inventors presume as follows. That is, when impregnated with an alkaline solution and subjected to dry heat treatment at high temperature, a part of the cellulosic molecules on the fiber surface is hydrolyzed or oxidized to increase the end groups and reducing groups such as carbonyl groups and aldehyde groups in the molecule.
So-called oxycellulose is considered to occur. This reducing group is extremely unstable to high concentrations of alkali, and therefore the reducing group becomes the starting point of alkali swelling and partial disintegration in the subsequent mercerizing treatment, and the mercerizing effect is significantly improved. It is thought that the durability will be further improved. In addition, the method of the present invention has an advantage that the decrease in strength is extremely small as compared with the case where the cellulose is oxidized using periodate, sodium chlorite, sodium hypochlorite, hydrogen peroxide and the like. . The reason for this point is not clear, but it can be inferred as follows. That is, in the mechanism of oxidation of cellulose by alkali, in the case of a relatively low concentration of alkali as in the method of the present invention, the oxidation by taking in oxygen in the air is dominant, and the dry heat treatment is carried out immediately after the alkali impregnation. Occasionally, the surface layer of the fiber, which is in high contact with oxygen in the air, is intensively oxidized, so that the effect on the inside or the crystalline part of the fiber is small, and as a result, in the case of the present invention method, compared with other oxidation methods. It is thought that the decrease in strength is reduced.

(Example) Next, an example of the method of the present invention will be described, but the present invention is not limited thereto.

Example 1 A cotton fabric after scouring and bleaching (a plain weave using warp and weft yarns in 10th count single yarn; weave density 38 warp / inch, weft 41 thread / inch) was padded with 50 g of sodium hydroxide / solution and picked up with a mangle. After squeezing at 75%, it was dried. Then, after performing a dry heat treatment at 170 ° C. for 1 minute with a baking machine, it was thoroughly washed with water with a soaper to complete the pretreatment.

Next, this pre-treated cloth was subjected to a normal mercerizing machine at a sodium hydroxide concentration of 19% at a low temperature of -6 ° C for 30 times.
This processing was completed by carrying out the mercerizing process for 2 seconds.

The woven fabric obtained by the method of the present invention thus obtained was provided with a surprisingly sharp feeling and repulsion, and had a texture very similar to that of a genuine hemp woven fabric. Moreover, the durability of the texture was very excellent.

For the purpose of comparison with the method of the present invention, a work cloth of Comparative Example 1 was obtained by carrying out processing in the same manner as in this example except that the pretreatment was not carried out and the mercerizing treatment was carried out at room temperature in this example. In addition, in this example, the fabric processed by scraping only the pretreatment (Comparative Example 2) and the fabric processed in exactly the same manner as this example except that the mercerization treatment was carried out at room temperature in this Example (Comparison) Example 3) was prepared and its performance was compared with that of the fabric processed by the method of the present invention. The results are shown together in Table 1.

From Table 1, it is clear that the pretreatment makes the texture harder in the mercerizing treatment, increases the sharpness, and is excellent in durability.

Example 2 Tenjiku knit cotton / (70% linen /
Use 20% single yarn of 30% blended) with potassium hydroxide 60
Pad with g / solution and pick up with mangle 8
After squeezing at 5%, it was dried. Then, after performing a dry heat treatment at 150 ° C. for 2 minutes with a baking machine, the product was thoroughly washed with water to complete the pretreatment.

Next, this pretreated cloth was subjected to a mercerizing treatment for 1 minute at a low temperature of -4 ° C with a sodium hydroxide concentration of 21% by an open mercerizing machine for knitting to complete the main processing.

The cotton / linen blended textile knit obtained in this way was strongly imparted with a dry dry feel, and had a feel that was indistinguishable from a knit product made of 100% hemp. Also, the durability of the texture was very good. (Effect of the invention) In the present invention, the low temperature mercerizing treatment is combined with the alkali treatment-dry heat treatment as its pretreatment. The fibers can be improved to have a texture close to that of natural hemp and the durability of the obtained hemp-like texture can be satisfied.

Claims (1)

[Claims] 1. A method for processing hemp hemp of cellulosic fibers, which comprises impregnating cellulosic fibers with an alkaline solution, then subjecting the fibers to dry heat treatment, and then subjecting the fibers to mercerization at low temperature.