JPH08291463A - Polyester hollow thick and thin yarn and its production - Google Patents

Abstract

PURPOSE: To stably obtain polyester hollow thick and thin yarn having high water absorption, a handle of excellent touch refreshing feeling and a dry feeling. CONSTITUTION: This polyester hollow thick and thin yarn comprises a polyester containing 0.2-2wt.% of silica particles by a dry process having <=0.1μm average particle diameter of primary particles and <=150m<2> /g specific surface area measured by BET method. The polyester hollow thick and thin yarn having a hollow part with >=25% hollow ratio, a fine unevenness structure on the surface of the yarn and through holes with 0.5-5μm diameters in the direction of the fiber axis and 0.5-5μm diameters in the width direction, extending from the surface of the yarn toward the hollow part, at least part of the yarn is obtained by subjecting a polyester polymer containing silica particles by a dry process to melt spinning to give undrawn yarn, unevenly drawing the undrawn yarn at a draw ratio of 0.45-0.55 times the maximum draw ratio at a temperature equal to or lower than the crystallization temperature, heat-setting the drawn yarn at a temperature equal to or higher than the glass transition temperature and equal to and lower than the crystallization temperature and subjecting the yarn to weight loss treatment with >=10% percentage loss by weight.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester hollow thick and thin fiber and a method for producing the same.

[0002]

2. Description of the Related Art Polyester fibers have many excellent properties and are used for various purposes including clothing.
However, since the polyester fiber is produced by the melt spinning method, it generally has a smooth fibrous surface, a hard hand, and a unique slimy feel, which is a disadvantage in the texture.

Polyester fibers also have a drawback in that they are inferior in water absorbency and sweat absorbability as compared with natural fibers such as cotton, silk and wool, and semi-synthetic fibers such as rayon and acetate fibers. Among these drawbacks, in order to improve the drawbacks particularly in terms of this function, a hollow fiber made of polyester to which a metal salt of an organic sulfonic acid is added is treated with an alkaline aqueous solution so that a part of the hollow fiber is communicated with the hollow portion. Water-absorbent polyester fibers having fine pores on the fiber surface are disclosed in JP-B-61-60188 and JP-B-62-44065.
It has already been proposed in Japanese publication.

However, the conventional polyester hollow fiber having a microporous surface has improved water absorption, but is not satisfactory in improving the texture.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a polyester hollow thick and thin fiber having a high water absorption property and an excellent cool touch feeling and a dry touch feeling, and
The purpose is to obtain such polyester hollow and thick fibers with good stability.

[0006]

According to the present invention, dry method silica particles having an average primary particle size of 0.1 μm or less and a specific surface area measured by BET method of 150 m ² / g or less are used.
A hollow thick and thin fiber made of polyester whose main repeating unit is 2% by weight is ethylene terephthalate, the hollow portion having a hollowness of 25% or more, the fine uneven structure on the fiber surface, and the fiber on at least a part of the fiber surface. A polyester hollow thick and thin fiber having pores penetrating from a fiber surface having a diameter in the axial direction of 0.5 to 10 μm and a diameter in the width direction of 0.5 to 5 μm to a hollow portion, and

The average particle diameter of the primary particles is 0.1 μm or less, B
A polyester polymer whose main repeating unit is ethylene terephthalate containing 0.2 to 2% by weight of dry process silica particles having a specific surface area of 150 m ² / g or less measured by ET method is melt-spun to obtain a hollow fiber unstretched fiber. ,
The unstretched fiber is non-uniformly stretched under the following conditions (1) and (2), and heat set under the following condition (3) to give a hollow thick fiber having a hollow ratio of 20% or more. A method for producing a polyester hollow thick and thin fiber, which comprises performing an alkali weight loss treatment with an aqueous solution at a weight loss rate of 10% or more.

(1) MDR × 0.45 ≦ DR ≦ MDR × 0.55 (2) HRT ≦ Tc (3) Tg ≦ HPT ≦ Tc where MDR is the maximum draw ratio of unstretched fibers, DR is the draw ratio, HRT is a drawing temperature (° C), HPT is a heat setting temperature (° C), Tc is a crystallization temperature (° C) of the undrawn fiber, and Tg is a glass transition temperature (° C) of the undrawn fiber.

The polyester hollow thick and thin fibers of the present invention contain 0.2 to 2 parts by weight of dry process silica particles having an average primary particle size of 0.1 μm or less and a specific surface area of 150 m ² / g or less measured by the BET method. % Of the main repeating unit is ethylene terephthalate. The polyester as a base is one having ethylene terephthalate as a main repeating unit in which terephthalic acid or an ester-forming derivative thereof is used as a dicarboxylic acid component and ethylene glycol or an ester-forming derivative thereof is used as a glycol component. A part of the component may be replaced with other dicarboxylic acid component and / or glycol component.

The other dicarboxylic acid component is, for example, adipic acid, sebacic acid, isophthalic acid, 5-sulfoisophthalic alkali metal salt, etc., and the other glycol component is, for example, propylene glycol, butylene glycol, polyethylene glycol, etc. Is mentioned.

The polyester may be synthesized by any known method. For example, polyethylene terephthalate will be explained. Either terephthalic acid and ethylene glycol are directly esterified or dimethyl terephthalate and ethylene glycol are transesterified. Then, a glycol ester of terephthalic acid or a low-condensation product thereof is prepared, and then polycondensation is carried out. Furthermore, in the synthesis, an arbitrary catalyst may be used, and an antioxidant, a coloring inhibitor, an ether bond by-product inhibitor, a flame retardant, etc. may be added.

The dry-process silica particles contained in the polyester in an amount of 0.2 to 2% by weight, preferably 0.4 to 1.5% by weight, have an average primary particle size of 0.1 μm or less at a liquid nitrogen temperature. It is necessary that the dry-process silica particles have a specific surface area of 150 m ² / g or less measured by the BET method, which is a method determined by nitrogen adsorption. The average particle diameter of the primary particles means the diameter of a virtual sphere having the same volume as the primary particles.

The polyester hollow thick fiber of the present invention is a thick fiber having a hollow portion with a hollow ratio of 25% or more,
The fiber surface has a fine concavo-convex structure and at least a part of the fiber surface has pores having a diameter in the fiber axis direction of 0.5 to 10 μm and a diameter in the width direction of 0.5 to 5 μm penetrating from the fiber surface to the hollow portion . When the hollow ratio is less than 25%, high water absorption cannot be obtained.

In the polyester hollow thick fiber of the present invention, when water is present on the surface of the fiber, the water moves from the surface of the fiber to the hollow portion through the through hole and is diffused by the capillary phenomenon of the hollow portion. Due to the rapid absorption of water from the surface of the fiber and the fine uneven structure of the surface of the fiber, excellent touch coolness and dry feel are provided.

FIG. 1 is a scanning electron microscope photograph (magnification: 2000) of the fiber surface of an example of the polyester hollow thick and thin fiber of the present invention.
Times).

The hollow polyester fine fibers of the present invention are produced by the method described below. In the present invention,
As the polyester polymer, a polyester polymer whose main repeating unit is ethylene terephthalate added and contained in the dry process silica particles at an arbitrary stage where the polyester synthesis reaction is completed is used, and the polyester polymer is an optional hollow fiber for producing a hollow fiber. Melt spinning is performed using a spinneret to obtain hollow fiber unstretched fiber.

The silica particles to be used have an average primary particle size of 0.1 μm or less. If the average particle size exceeds 0.1 μm, a fine uneven structure on the fiber surface is not formed and a sufficient dry feeling cannot be obtained. Further, when the specific surface area is 150 m ² / g or less,
When it exceeds 150 m ² / g, the silica particles are likely to be secondarily aggregated in the production process of the polyester polymer and the fiber, and the stability of the yarn making process is deteriorated. The dry process silica particles are added to the polyester polymer in an amount of 0.2 to 2% by weight, preferably 0.4 to 1.5% by weight. If the addition amount is less than 0.2% by weight, the fine uneven structure on the fiber surface is not formed, and the pores penetrating from the fiber surface to the hollow portion are not formed, so that good water absorption cannot be obtained. If it exceeds%, the stability of the yarn making process and the passing stability of the high-order processing process are deteriorated.

Then, this unstretched fiber is drawn at a draw ratio DR.
MDR (maximum draw ratio of unstretched fiber) x 0.45-M
The draw ratio in the range of DR × 0.55 and the stretching temperature HRT are set to a temperature equal to or lower than the crystallization temperature Tc of the unstretched fiber, and the heat setting temperature HPT is set to a non-uniformly stretched to obtain a predetermined shrinkage ratio. The glass transition temperature Tg to the crystallization temperature Tc is set and heat set to obtain hollow thick fibers having a hollow ratio of 20% or more. When the hollow ratio is less than 20%, it becomes difficult to form a through hole with a hollow ratio of 25% or more in the subsequent alkali weight loss. In the present invention, the hollow thick and thin fibers have a breaking elongation of 50 to 12 in order to obtain passage stability in a subsequent step and a dry feeling.
It is preferably 0% and the boiling water shrinkage is 10 to 70%.

Further, in the present invention, the hollow thick and thin fibers are optionally heat treated or false twisted, and then
Alternatively, after further forming a cloth, an alkali weight loss treatment is performed with an aqueous solution of an alkaline compound at a weight loss rate of 10% or more.

For the alkali weight reduction treatment, an aqueous solution of an alkaline compound is used, and as the alkaline compound, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, tetramethylammonium hydroxide, etc. are used, especially sodium hydroxide, Potassium hydroxide is preferably used. The concentration of the aqueous solution varies depending on the type of alkaline compound, treatment conditions, etc., but is 0.1 to 30% by weight, and the treatment is performed at a treatment temperature of room temperature to 100 ° C.
Preferably, the temperature is 70 to 100 ° C., the treatment time is 1 minute to 4 hours,
It is preferably carried out for 30 to 90 minutes, preferably by immersing in an aqueous alkaline compound solution.

By reducing the weight by 10% or more by the alkali weight reduction treatment, a hollow portion having a hollowness of 25% or more is formed, silica particles are dropped, and a fine concavo-convex structure is formed on the entire fiber surface and at least a part of the fiber surface is formed. The diameter in the fiber axis direction is 0.
A through hole communicating with the hollow portion having a width of 5 to 10 μm and a diameter in the width direction of 0.5 to 5 μm is formed.

[0022]

EXAMPLES The present invention will be specifically described below with reference to examples. The characteristic values in the examples were measured or judged by the following methods or standards. Further,% and parts in the examples mean% by weight and parts by weight.

(Spinning stability, water absorption performance and texture) ○: Good △: Fairly good ×: Poor

(Water absorption performance by the dropping method) The following conditions are used for the hollow thick thin yarn as the raw yarn: warp: polyester normal yarn 50 denier / 24 filament Weft: hollow thick thin polyester fiber yarn 100 denier / 3
0 filament Warp density: 59.1 yarns / cm Weft density: 25.5 yarns / cm After weaving, scouring, presetting, and alkali weight reduction treatment at a boiling temperature for a predetermined time using a 3% aqueous solution of sodium hydroxide. This woven fabric was attached as a sample to a circular frame for embroidery with a diameter of 15 cm, and the disappearance time of water drops on the sample dropped by the water drop dropping method was measured. Distilled water was used for the water droplets, the water droplet amount was 0.033 ml, the distance between the burette tip and the sample surface was 1 cm, the room temperature was 22 ° C., and the relative humidity was 55 to 60%. I asked.

(Water absorption performance by the Bayrek method) The woven fabric subjected to the alkali weight reduction treatment was used as a sample piece having a length of 15 cm and a weft of 3 cm, and the upper end of the sample piece was stopped at a fixed height position on a vat containing distilled water. Make sure the bottom edge comes into contact with distilled water,
Ten minutes after the sample piece started to absorb water, the height (rise distance) where the water rose was measured. The measurement was carried out at room temperature of 22 ° C. and a relative humidity of 55 to 60%, and the average rising distance of 5 to 7 measurements was obtained.

Example 1 100 parts of terephthalic acid and 52 parts of ethylene glycol were charged into an esterification tank and 4 kg.
The esterification reaction was performed at 260 ° C. under a pressure of / cm ² . Subsequently, the obtained reaction product was added with trimethyl phosphate 0.01% (pair-forming polymer), antimony trioxide 0.04% (pair-forming polymer), average particle diameter of primary particles was 0.04 μm, and measured by the BET method. 0.4% of dry process silica particles having a measured specific surface area of 50 m ² / g was added as an ethylene glycol solution or dispersion, and polycondensation reaction was performed at 285 ° C. under high vacuum in a polymerization tank to obtain phenol / 25 in a mixed solvent of tetrachloroethane = 1/1
Intrinsic viscosity of 0.68 measured by Ostwald viscometer at ℃
A polyester polymer of

The polymer was made into chips by a conventional method, dried, and then spun at a spinning temperature of 285 ° C. using a circular hollow spinneret having 30 holes. After the spun yarn was cooled and solidified, an oil agent was applied and wound at a winding speed of 1800 m / min. This unstretched yarn is drawn at a draw ratio of 1.75 and a temperature of 110.
C., and then heat set at a tension ratio of 1.01 and a temperature of 120.degree. C. and a fiber hollowness of 30% of 100 denier /
A hollow thick yarn of 30 filaments was obtained.

After weaving the obtained hollow thick yarn, the weight reduction rate was reduced to 20% by alkali weight reduction treatment at a boiling temperature using a 3% aqueous solution of sodium hydroxide. The resulting hollow thick fiber constituent fibers of the woven fabric had a hollowness of 48%, a fine concavo-convex structure on the entire fiber surface, and a fiber axial diameter of 0.5 to 10.
It had a through hole from the fiber surface having a diameter of 0.5 μm and a width direction diameter of 0.5 to 5 μm to the hollow portion. The obtained woven fabric had a dry and excellent texture without a slimy feel and had an excellent water absorption performance as shown in Table 1. In addition, Table 1 also shows the stability of yarn production when a hollow thick yarn is obtained.

(Examples 2-3, Comparative Examples 1-4) Example 1
In the same manner as in Example 1, except that the amount of silica particles added, the fiber cross section, and the stretching method were changed, a polyester polymer was spun and stretched into a hollow thick and thin yarn in the same manner as in Example 1,
The obtained hollow thick thin yarn was woven and subjected to alkali weight reduction treatment to a weight loss rate of 20%. Table 1 shows the yarn-forming stability and the water absorption performance of the obtained woven fabric when the hollow thick yarn is obtained.

[0030]

[Table 1]

[0031]

The polyester hollow thick and thin fiber of the present invention is
It has a high hollow ratio and a through hole from the fiber surface to the hollow part, so it has high water absorbency, exhibits an excellent cool feeling to the touch, and has a fine uneven structure on the entire fiber surface, so there is no slimy feeling. It has a dry feel and is particularly suitable in the field of clothing. Further, according to the present invention, such polyester hollow thick and thin fibers can be obtained with good stability.

[Brief description of drawings]

FIG. 1 is a scanning electron micrograph (magnification: 2000 times) of a fiber surface of an example of a polyester hollow thick fiber of the present invention.

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Claims (2)

[Claims] 1. The average particle diameter of primary particles is 0.1 μm or less,
A hollow thick fiber made of polyester whose main repeating unit is ethylene terephthalate, containing 0.2 to 2% by weight of dry process silica particles having a specific surface area of 150 m ² / g or less measured by BET method, and having a hollow ratio of 25% or more hollow part, fine uneven structure on the fiber surface and at least part of the fiber surface has a fiber axis direction diameter of 0.5 to 10 μm and a width direction diameter of 0.5 to 5 μm from the fiber surface to the hollow part A hollow polyester thin fiber characterized by having fine pores penetrating therethrough. 2. The average particle diameter of the primary particles is 0.1 μm or less,
A polyester polymer whose main repeating unit is ethylene terephthalate and which contains 0.2 to 2% by weight of dry process silica particles having a specific surface area of 150 m ² / g or less measured by BET method is melt-spun to obtain an unstretched hollow fiber. The non-stretched fiber is non-uniformly stretched under the following conditions (1) and (2), and heat-set under the condition (3) below to obtain a hollow ratio of 20.
% Of the hollow thin fibers, and then an alkali weight reduction treatment with an aqueous solution of an alkaline compound at a weight loss rate of 10% or more is carried out. (1) MDR × 0.45 ≦ DR ≦ MDR × 0.55 (2) HRT ≦ Tc (3) Tg ≦ HPT ≦ Tc where MDR is the maximum stretch ratio of unstretched fibers, DR is the stretch ratio, and HRT is the stretch ratio. Temperature (° C), HPT is heat setting temperature (° C), Tc is crystallization temperature (° C) of unstretched fiber, and Tg is glass transition temperature (° C) of unstretched fiber.