KR100359336B1 - A sea-island typed composit fiber used in warp knitting - Google Patents

Abstract

The present invention relates to a warp island-in-the-sea composite fiber, comprising a seaweed component of an alkali-soluble copolyester and a polyester island component having a main component of polyethylene terephthalate of 90 mol% or more, and prepared by spinning direct drawing. In the composite fiber, it is characterized by satisfying the following physical properties at the same time.

-Below-

Yarn modulus after dissolution of sea component: 25 ~ 60g / d

Yarn elongation after dissolution of sea component: 40 ~ 60%

Yarn strength after dissolution of sea component: 2.0 ~ 4.0g / d

The island-in-the-sea composite fiber of the present invention has excellent yarn modulus after elution of sea component, thereby minimizing yarn damage during raising to improve the feel and appearance of warp knitted paper.

Description

A sea-island typed composit fiber used in warp knitting}

The present invention relates to a island-in-the-sea composite fiber for warp knitting.

The island-in-the-sea composite fiber is manufactured by using an alkali-soluble polymer as a sea component and a fiber-forming polymer as a island component, and composite spinning them into an island-in-the-sea type, mainly for the purpose of producing ultrafine fibers. Is being produced. In other words, after preparing the island-in-the-sea composite fiber, it is treated with an alkaline solution to elute the sea component which is an alkali-soluble polymer, thereby producing an ultrafine fiber composed only of the island component.

As described above, the method of manufacturing the ultrafine fibers from the island-in-the-sea composite fiber has the advantages of superior spinning and stretching operations and more fineness of fine fibers compared to the method of manufacturing the ultrafine fibers by direct spinning. After knitting, the process of eluting and removing the sea component polymer with an organic solvent in a processing step is required. Therefore, the sea component polymer is very important to be easily dissolved in an organic solvent or a solution, and yarn modulus after sea component elution.

In general, alkali-soluble copolyester is mainly used as the sea component polymer used in the island-in-the-sea composite fiber. The reason for this is that the dissolution of the sea component is possible in alkaline solutions and weight reduction facilities which are widely applied in weight reduction processing of general polyester fabrics without the use of special equipment and costly organic solvents.

When the water-based polymer is nylon, the dissolution rate of the sea component is not very important because the degree of nylon invasion by the alkaline solution is very low when the sea component is eluted. If the speed is low, the island component is violated before the sea component is completely eluted, and the yarn strength is drastically lowered after the dissolution. As a result, the raising properties are poor and it is difficult to express the appearance and feel of the target final product.

On the other hand, if the dissolution rate of the sea component is fast, not only the occurrence of the above problems can be suppressed, but also the alkali concentration, elution temperature and time can be reduced, thereby reducing the elution cost and increasing productivity. However, in order to increase the dissolution rate of the sea component, the content of the copolymer compound should be increased. However, when the content of the copolymer compound is excessively increased, the elution property is improved, but the melting point of the polymer is eliminated and it is an amorphous polymer with only a softening point. It becomes difficult. In addition, the yarn before the eluting strength is lowered, the brushing occurs when the brush is entangled with each other, and the polymer manufacturing cost increases due to the increased input of the copolymer compound.

Conventional techniques for producing alkali-soluble polyesters used in the production of islands-in-the-sea composite fibers include, firstly, dimethyl-5-sulfoisophthalate sodium salt (hereinafter referred to as "DMIS") or low molecular weight polyalkyls during the polyester polymerization process. A method of copolymerizing lene glycol (hereinafter referred to as "PAG"), a method of blending a second polyester and a high molecular weight PAG, and a method of blending a third polyester polymer and a high molecular weight PAG are known.

Conventional islands-in-the-sea composite fibers prepared by the conventional spinning direct stretching method using the alkali-soluble leaching polyester described above as the sea component and the polyester as the island component have a high degree of the island component by the alkaline solution during the sea component elution process. There is a problem that the yarn modulus after damage and elution of sea component is poor. As a result, in the subsequent raising process after warp knitting, the yarn was severely damaged and dropped, resulting in a deterioration in brushing and deteriorating the appearance and quality of the warp knit.

An object of the present invention is to provide an island-in-the-sea composite fiber which is particularly useful as a warp yarn for the excellent yarn modulus after sea component elution in order to solve this problem.

The present invention, by controlling the yarn modulus, crystallinity and birefringence in each step of the weaving process to the appropriate range, the physical properties of the yarn is minimized when dissolution or napping sea components to provide a sea island-type composite fiber particularly suitable for warp knitting yarn.

1 is a process schematic diagram of the present invention

※ Explanation of main parts in drawings

1: spinneret 2: first go roller

3: second gourd roller 4: winder

In order to achieve the above problems, the warp island-in-the-sea composite fiber of the present invention is composed of a seaweed component of an alkali-soluble copolyester and a polyester coating component having a main component of polyethylene terephthalate of 90 mol% or more, and manufactured by a spinning direct drawing method. In the island-in-the-sea composite fiber for warp knitting, the following physical properties are simultaneously satisfied.

-Below-

Yarn modulus after dissolution of sea component: 25 ~ 60g / d

Yarn elongation after dissolution of sea component: 40 ~ 60%

Yarn strength after dissolution of sea component: 2.0 ~ 4.0g / d

Hereinafter, the present invention will be described in detail.

First, in the present invention, alkali-soluble co-polyester is used as a sea component, and ordinary polyester is used as a island component, and these are combined-spun into a conventional island-in-the-sea composite spinneret 1. At this time, 3-15 mol% of DMIS is copolymerized with polyethylene terephthalate, and copolymerized polyester etc. which added 4-20 weight% of polyethyleneglycols whose number average molecular weight is 8,000 or more are used here.

Subsequently, the present invention draws the spun yarn while passing through the first go roller 2 and the second go roller 3, and winds it up with a winder 4 to produce an island-in-the-sea composite fiber. In other words, the present invention is produced by the spinning direct stretching method in which spinning and stretching are performed in the same process.

At this time, it is preferable that the speed V ₁ of the first high roller is set to 1,000 to 5,000 m / min, and the speed V ₂ of the second high roller is set to 1,500 m / min to 6,000 m / min. If the speed of the first high roller (2) and the second high roller (3) is out of the above range, the modulus of the yarn is too low, the cutting is uneven in the future raising process, and the weight loss process is unable to control the weight loss. In addition, the birefringence and density of the yarn is lowered, the modulus is weakened, the warp workability, etc. are deteriorated.

In addition, it is preferable to adjust the yarn physical properties at each step (position) of the spinning process as follows.

First, the manufacturing conditions are set such that the degree of crystallinity of the yarn on the first high roller, that is, the degree of crystallinity of the yarn passing through the first high roller, is 8.5 to 25%. If it is higher than the above range, the modulus decreases in the drawing section, which makes the process impossible. If the drawing is too low, the drawing may require excessive drawing to obtain the desired final yarn properties. As a result, the yarn property variation becomes large and a process problem occurs.

Further, the manufacturing conditions are set such that the yarn birefringence Δn on the second high roller is 0.10 to 0.20. If it is out of the above range, the final yarn has excessively high mechanical properties, making it unsuitable as a garment yarn, and a fatigue phenomenon that polymers cannot tolerate on the yarn accumulates, resulting in a sharp deterioration of yarn properties. .

Further, it is more preferable that the yarn modulus under detention is 5 to 20 g / d. If the yarn modulus under the custody exceeds 20g / d, the stress applied to the yarn may be excessive, resulting in a problem of deterioration of spinning operability due to bursting of yarn bundles or trimming.

The degree of yarn crystallinity on the first roller is cut at the leading end of the first roller and then wound around the surface of the first roller at approximately the same time as the cutting of the yarns of the dead adipose yarn using the capture at the rear of the first roller. Is a value obtained by taking a sample immediately after cutting and measuring the degree of yarn crystallization by the method described later.

More specifically, during sampling, the filament located on the surface of the filament layer wound on the first roller is collected, and immediately cut to prevent the change of yarn properties by the temperature of the first roller.

The birefringence of the yarn on the second roller is cut at the same time as the yarns of the yarns being spun at the front and rear of the second roller by using the capture, and the sampled filament wound on the surface of the second roller is immediately taken by cutting. It is the value which measured the birefringence of the yarn by the method of mentioning later. If the sample is not taken immediately after the yarn is cut, the yarn properties may change with the temperature of the second roller.

Here, the birefringence of the yarn on the second gourd roller was treated by 30 minutes of the island-in-the-sea composite fiber (sample) collected in the above manner in a 1% NaOH solution and eluted the sea component among them. Value.

Under detention, the yarn modulus measures the modulus by taking a sample using a capture of 1 m in length from the spinning point of the spinning yarn.

The island-in-the-sea composite fiber of the present invention preferably has a total fineness of 50 to 90 denier having a single yarn fineness of 2 to 4 deniers before sea component elution and a 0.01 to 0.3 denier single yarn fineness after sea component elution. The island-in-the-sea composite fiber of the present invention has a yarn modulus of 25 to 60 g / d, an elongation of 40 to 60%, and an intensity of 2.0 to 4.0 g / d after sea component elution.

After knitting the warp knitted paper with the island-in-the-sea composite fiber prepared by the method of the present invention, the sea component is eluted with an alkaline solution and brushed to prepare a brushed warp knit. The elution of the sea component is carried out by treating the island-in-the-sea composite fiber at 95 ° C. for 30 minutes in a 1% sodium hydroxide solution (bath ratio = 10: 1).

The island-in-the-sea composite fiber produced by the method of the present invention is minimized in yarn seam elution in the sea component elution process or brushing process due to the elution property and yarn property characteristics of the sea component. As a result, the raising property is improved, and the appearance and feel of the warp knitted fabric as the final product are excellent.

In the present invention, the yarn physical properties were evaluated as follows.

Strength / Elongation / Modulus

The average value is obtained by measuring 50 times with a tensile tester of Instron Co., Ltd. (sample length: 25cm, tensile speed: 300mm / min). Here modulus means initial modulus.

Density (ρ)

The island-in-the-sea composite fiber was added to a density meter (normally manufactured by Shibayama, Japan, Model SS) consisting of a mixed solvent of normal heptane and carbon tetrachloride, and left at 23 ° C. for 1 day. Measure the density of

Crystallinity [Xc (%)]

Based on the above density (ρ) value, the following formula is obtained by using the theoretical density value of the complete crystal region of polyester (ρ _c = 1.457 g / cm 3) and the density value of the amorphous region (1.336 g / cm 3).

Birefringence (Δn)

It was measured by an interference microscope (from Carl Zeiss, Germany, model name: JENAPOL -U INTERPHAKO). The birefringence is calculated by the formula below.

Where R is the compensator retardation, S is the retardation of quartz shim, and D is the fiber diameter. In addition, the units of R and S are nm and the units of D are μm.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the following Examples.

Example 1

An alkali-soluble polymer is prepared by blending 8% by weight of polyethylene glycol having a number average molecular weight of 8,500 to a copolymerized polyester having 4 mol% of dimethyl-5-sulfoisophthalate sodium. Using the prepared alkali-soluble polymer as a sea component, and polyethylene terephthalate having an intrinsic viscosity of 0.65 as a island component, they are spun through a island-in-the-sea composite spinneret having 36 island components at 288 ° C. The spun yarn was then drawn between a first high roller at 80 ° C. with a speed of 1,500 m / min and a second high roller at 125 ° C. with a speed of 4,200 m / min, and then wound at a winding speed of 4,300 m / min. A sea island type composite fiber of 75 denier 24 filaments is prepared. At this time, the manufacturing conditions were set such that the modulus of yarn under detention was 18 g / d, the degree of crystallinity of the yarn on the first high roller was 8.8%, and the refractive index of the yarn on the second high roller was 0.141. The island-in-the-sea composite fiber thus prepared was treated in a 1% NaOH solution at 95 ° C. for 30 minutes to elute the sea component, and then the raw material properties after the sea component elution were evaluated by the method described above.

Example 2-Example 3 and Comparative Example 1-Comparative Example 2

The island-like composite fibers of 75 denier 24 filaments were manufactured under the same process and conditions as in Example 1 except that the manufacturing conditions such as the first high roller speed were changed as shown in Table 1. The island-in-the-sea composite fiber prepared as described above was treated in a 1% NaOH solution at 95 ° C. for 30 minutes to elute the sea component, and the raw material properties after the sea component elution were evaluated by the method described above.

Manufacture conditions division 1st high roller speed (m / min) Second high roller speed (m / min) Yarn modulus under detention (g / d) 1st high roller phase yarn crystallinity (%) 2nd high roller phase yarn birefringence (Δn) Example 1 1,500 4,300 18 8.5 0.141 Example 2 1,600 4,100 19 9.5 0.137 Example 3 3,000 5,450 17 10.7 0.148 Comparative Example 1 3,000 6,500 21 10.5 0.205 Comparative Example 2 800 4,000 18 8.2 0.131

Yarn property evaluation result division Yarn Properties after Sea-Component Elution Elongation (%) Strength (g / d) Modulus (g / d) Example 1 47.23 3.71 36.47 Example 2 45.72 3.84 38.29 Example 3 49.37 3.56 34.28 Comparative Example 1 23.8 1.24 17.98 Comparative Example 2 36.4 1.38 22.55

The island-in-the-sea composite fiber for warp knitting according to the present invention minimizes damage to yarn modulus during seawater dissolution and raising process. As a result, it is excellent in brushing when manufacturing the warp knitted paper, it is possible to manufacture a warp knitted paper with excellent feel and appearance. Due to this effect, the island-in-the-sea composite fiber produced by the method of the present invention is particularly useful for producing brushed warp knits.

Claims (3)

It is composed of a seaweed component of alkali-soluble copolyester and a polyester island component having a main component of polyethylene terephthalate of 90 mol% or more, and is a warp island-in-the-sea composite fiber manufactured by spinning direct drawing method, which satisfies the following physical properties simultaneously Island-in-the-sea composite fiber for warp knitting. -Below- Yarn modulus after dissolution of sea component: 25 ~ 60g / d Yarn elongation after dissolution of sea component: 40 ~ 60% Yarn strength after dissolution of sea component: 2.0 ~ 4.0g / d The warp island island-type composite fiber according to claim 1, wherein the single yarn fineness before sea component elution is 2 to 4 denier. The warp island island-type composite fiber according to claim 1, wherein the single yarn fineness after dissolution of the sea component is 0.01 to 0.3 Dain fish.