KR20050002282A - Process of producing differential shrink Rayon/PTT compound yarn - Google Patents

Abstract

PURPOSE: A manufacturing method of different shrinkable composite fiber of rayon / polytrimethylene terephthalate(PTT) is characterized by using high shrinkable cellulose diacetate fiber as core yarn, supplying low shrinkable PTT fiber as effect yarn and giving excellent bulkiness, drapeability, hygroscopicity and touch. CONSTITUTION: Different shrinkable composite fiber of rayon/ polytrimethylene terephthalate is obtained by the steps of: using high shrinkable cellulose diacetate fiber having 2-2.75 of substitution as core yarn; supplying low shrinkable PTT fiber as effect yarn; air-confounding the fibers to manufacture confounded yarn; tension-heating the confounded yarn; weaving fabric out of the yarn; and then treating the fabric at 70-120deg.C for 1-120min. with alkali to saponify the cellulose diacetate and to generate difference of shrinkage. A saponifying process satisfies formula(I). The formula(I) is 5<=SSP(H)-SSP(L)<=15. In the formula(I), SSP(H) is shrinking percentage of the cellulose diacetate fiber; and SSP(L) is shrinking percentage of the PTT fiber in the saponifying process.

Description

Process of producing differential shrink Rayon / PTT compound yarn}

The present invention is generated in the rayonization process of cellulose diacetate fibers in which air is entangled with poly trimethylene terephthalate (hereinafter referred to as 'PTT') fibers and cellulose diacetate fibers (degree of substitution 2.0 to 2.75). The present invention relates to the production of rayon / PTT biaxially conjugated fibers having a soft touch and a natural appearance by using a shrinkage ratio and the bishrinkage property of PTT fiber, and having excellent bulkiness in the fabric state, and having a drape property and an excellent bishrinkage effect.

PTT is a fiber made by polycondensation of 1,3-propanediol and terephthalic acid. PET is a polycondensation product of TPA (or DMT) and ethylene glycol (EG). And its chemical structure is similar, but its elasticity, alkali loss, touch and dyeing are affected by thermal, mechanical and chemical resistance. Elongation is 45-55% and strength is 3-4g / L. These PTT fibers have excellent elasticity, atmospheric dyeing and soft touch that PET does not have, and are recently commercialized as a material having pollution resistance and drape, which is a disadvantage of nylon, and has been attracting considerable attention.

Although rayon has high specific gravity, it has excellent weight and rebound elasticity, but its strength is weak, so it is limited in its development. However, it can be supplemented with synthetic fiber such as PTT. In addition, PTT can provide dimensional stability and shape retention through heat-setting process that heats at high temperature, and can complement morphological stability, which is the biggest disadvantage of rayon. Rayon has good hygroscopicity and antistatic property. It can solve the problems such as static electricity, and can produce products with various effects by the difference in dyeability and touch between the two fibers.

When producing bi-shrink composite fiber by mixing rayon and PTT fiber by the conventional method, the shrinkage effect is small with 0 ~ 4% of rayon shrinkage and 8 ~ 11% of PTT fiber, so the shrinkage effect is small. There was a disadvantage that the characteristics of the elasticity is not properly expressed.

Therefore, the present invention is a new method for producing a textile product having excellent volume, drape, hygroscopicity and tactile feeling composed of rayon / PTT biaxially-composite yarn by increasing the shrinkage difference between rayon and PTT without the problems of the prior art as described above The purpose is to provide.

According to the present invention to achieve the above object, the high shrinkage cellulose diacetate fiber as a screening, the low shrinkage PTT fiber is supplied to the effector and air entangled to produce a entangled yarn, after the tension heat treatment to manufacture a fabric, Provided is a method for producing a rayon / PTT bishrink composite fiber, characterized in that a shrinkage difference is generated by a saponification process of cellulose diacetate through alkali treatment.

Hereinafter, the present invention will be described in more detail.

The biaxially conjugated composite fiber of the present invention is prepared by cellulose diacete as the screening, and by air entanglement with the PTT fiber as the effect yarn. After manufacturing the fabric using the composite yarn hydrated the acetyl group of the cellulose diacetate by treating once or twice in 1 ~ 120 minutes at 70 ~ 120 ℃ alkaline aqueous solution of 30 to 40% compared to the used cellulose diacetate fiber It is saponified with a hydroxy group to prepare rayon / PTT biaxially conjugated fiber.

Alkali treatment of cellulose diacetate results in the saponification of the conversion of the acetyl group to the hydroxy group, at which time crystallization occurs by rearranging and folding the molecular chains of the diacetate fibers. In general, natural cellulose has a crystalline structure of cellulose I, and general regenerated cellulose fibers such as viscose rayon and cupra rayon have cellulose II structure and are converted to cellulose IV by a special process of high temperature heat treatment of cellulose fiber. It is known that the cellulose fibers prepared by saponification of cellulose diacetate have a crystal structure in which celluloses II and IV are mixed. The degree of crystallinity (specific gravity method) is 14 to 34% and the birefringence is 0.012 to 0.024. The above reaction is performed under alkaline conditions and 17-25% shrinkage of the cellulose diacetate fiber occurs depending on the reaction conditions used in the crystal formation process.

The properties of the rayon fiber produced by the above method are 1.48∼1.51 g / cm3, tensile strength is 1.2∼2.5gf / de, elongation is 20 ~ 50%, standard moisture content is 12 ~ 14%, similar to general rayon. Shows performance.

In this invention, it is preferable that the cellulose diacetate fiber used for screening is 2-2.75 degree of substitution, and satisfy | fills following formula (I) in a saponification process.

5 ≤ SSP (H)-SSP (L) ≤15 ------------ (I)

(SSP (H) is the shrinkage rate of cellulose diacetate fibers in the saponification process, and SSP (L) is the shrinkage rate (%) of the PTT fibers in the saponification process.)

In the saponification process of the present invention, both PTT fibers and cellulose diacetate fibers have a property of reducing weight due to alkali, so that only cellulose diacetate fibers are selectively reduced by 32 to 40wt% compared to cellulose acetate fibers using alkali concentration. It was processed as.

Examples of alkali compounds that can be used in the present invention include alkali metal hydroxides such as sodium hydroxide, alkaline earth metal hydroxides such as calcium hydroxide, alkali metal carbonates such as sodium carbonate and the like. These alkali compounds may be used alone or in combination with a reaction rate modifier.

As reaction rate regulators that can be used in the present invention, phosphonium-based saponification agents and quaternary ammonium-based saponification agents are well known. Commercially available examples of reaction rate modifiers include phosphonium-based neorate NCD (NEORATE NCD); Quaternary ammonium-based KF NEORATE NA-40 (KF NEORATE NA-40: Korea Precision Products), DYK-1125 (DYSA-1125), Casein PES, Casein PEL , Casein PEF (Sungogen Chemical Products), SNOGEN PDS (Daeyoung Chemical Products), and the like.

In the present saponification process in the present invention can be treated in a copper bath or bathing process of strong alkali and weak alkali. The shrinkage of the fiber occurs during the saponification and crystal formation of the cellulose diacetate, wherein the shrinkage rate is 13 to 25% for cellulose diacetate and 8 to 10% for PTT fiber. Therefore, the shrinkage difference between each other is generated, the rayon fiber produced by saponification as a core yarn and PTT fiber as an effect yarn. However, the existing rayon fiber can only bring about 5-6% shrinkage under normal processing conditions and thus cannot bring about a biaxial shrinkage compound effect.

Fabrics produced by the present invention is excellent in the sense of volume by the effect of rayon / PTT bishrinkage composite fiber, exhibited excellent drape, hygroscopicity, elasticity and soft touch.

Features and other advantages of the present invention as described above will become more apparent from the following examples. However, the present invention is not limited to the following examples.

Example 1

Cellulose diacetate fiber (SK Chemical) 75d / 20f and PTT fiber (Huvis) 75d / 72f with acetyl substitution degree 2.55 were treated with air pressure at 2.0kg / ㎠ to obtain 40 / The cellulose diacetate / PTT composite yarn was prepared by imparting m interlock. After heat-treating the above composite yarn at 80 ℃ for 30 minutes, put 2/2 plain fabric (weaving density 82 yarns / inch, weft density 70 yarns / inch) woven using warp and weft yarn in a liquid dyeing machine. Add 32wt% caustic soda and quaternary ammonium salt reaction rate modifier 1g / L, increase the temperature from 30 ℃ to 100 ℃ at 2 ℃ / min, process for 30 minutes, and then cool down to 30 ℃ at 2 ℃ / min. After draining and washing with water, the solution was neutralized with acetic acid. In addition, in order to determine the loss and shrinkage rates of the two fibers, the cellulose diacetate fibers and the PTT fibers were not woven together and placed in a liquid container.

At this time, the loss ratio of the acetate portion was 33 to 40%, and the loss ratio of the PTT portion was 0%. The weight loss rate is measured as the weight change of the sample before and after the alkali treatment, and the difference in the sample weight before and after the treatment is expressed as a percentage of the value obtained by dividing the sample weight before the treatment. The degree of deacetylation was confirmed by infrared spectroscopy using an infrared spectrometer (MAGNA 750, nicolet, USA).

Example 2

A composite fiber was prepared and treated in the same manner as in Example 1 except that the amount of caustic soda was 34%.

Example 3

A composite fiber was prepared and treated in the same manner as in Example 1 except that the amount of caustic soda was 36%.

Example 4

A composite fiber was prepared and treated in the same manner as in Example 1 except that the amount of caustic soda was 40%.

Comparative Example 1

Viscose Rayon (Asahi, Japan) 75d / 20f yarn and PTT fiber (Huvis, 75f / 72d yarn) are treated with a pressure of 2.0kg / ㎠ through an air nozzle to give 40 / m entanglement PTT composite fibers were prepared. After heat-treating the blended yarns at 80 ° C for 30 minutes, use a 2/2 plain fabric (93 inclination density / inch, 75 weft density / inch) of soda ash 1g / L and refiner 0.5 After adding g / L, it was refined at 100 ° C. for 30 minutes.

Table 1 shows the shrinkage ratios of the member yarns of the fibers prepared by the examples and the comparative examples and the characteristics of the entire fabric.

Acetate loss rate Shrinkage Softness Drape Castle Resilience Parts cellulose PTT Difference Example 1 33.2 13 9 3.5 O O O O Example 2 34.8 17 9 7.5 ◎ O O O Example 3 37.3 22 9.5 12.5 ◎ ◎ ◎ O Example 4 40.2 23 9.5 13.5 ◎ ◎ ◎ ◎ Comparative Example 1 - 4.7 9.5 4.8 O △ O X

X: Poor, Δ: Normal, O: Good, ◎: Very good.

Table 1 shows the loss ratio of each fiber and the shrinkage rate of each yarn according to the treatment conditions of the Examples and Comparative Examples. Example 3 Infrared spectroscopic analysis of the sample showed that the carbonyl peak of the acetyl group disappeared completely at 1760 cm ⁻¹ seen in the original diacetate fiber, indicating that complete rayon fiber was prepared. In addition, in the case of the embodiment, the shrinkage of the cellulose acetate fiber occurs through the rayonization process, resulting in a bi-shrinkage composite effect by the difference in shrinkage with the PTT fiber, showing excellent volume, drape, and touch.

In Comparative Example 1, the PTT fiber showed a larger shrinkage rate than the rayon fiber, and the difference was 3%, which did not express the effect of the biaxial shrinkage, and thus there was no improvement in volume, drape, and touch.

As will be apparent from the above results, the composite fiber produced according to the present invention has a high shrinkage caused by the conversion of cellulose diacetate fibers into cellulose fibers, resulting in a difference in shrinkage with PTT fibers used as effect yarns. Because it brings about the shrinkage effect that could not be expressed by rayon fiber and PTT fiber, the fabric using the same shows excellent parts, softness and drape property compared to the fabric made of rayon / PTT fiber.

Claims (5)

After the cellulose diacetate fiber, a high shrink yarn, is fed to the effect yarn, PTT fiber, a low shrink yarn, is fed to the effect yarn, and air entangled to produce a entangled yarn, followed by tension heat treatment and fabrication, and then saponification of cellulose diacetate through alkali treatment. Rayon / PTT bi-shrink composite fiber manufacturing method characterized in that the difference in shrinkage. The method for producing a rayon / PTT bishrink composite fiber according to claim 1, wherein the cellulose diacetate fiber used for screening has a degree of substitution of 2 to 2.75 and satisfies the following formula (I) in the saponification process. 5 ≤ SSP (H)-SSP (L) ≤15 ------------ (I) (SSP (H) is the shrinkage rate of cellulose diacetate fibers in the saponification process, and SSP (L) is the shrinkage rate (%) of the PTT fibers in the saponification process.) The process according to claim 1, wherein the alkali treatment temperature in the saponification step is 70 to 120 ^° C., the alkali treatment time is 1 to 120 minutes, and the alkali concentration is set to 32 to 40 wt% relative to the cellulose acetate fibers used. Rayon / PTT biaxial composite fiber manufacturing method characterized in that The method of producing a rayon / PTT biaxial composite fiber according to claim 1, which is prepared by a copper bath or a bathing process of strong alkali and weak alkali in the saponification process. The method according to any one of claims 1 to 4, wherein a quaternary ammonium salt or phosphonium salt is added as a reaction rate modifier in the saponification process.