JPH06200439A - Spontaneously stretchable polyester filament yarn having uneven denier and its production - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] Providing spontaneously stretchable polyester thick and thin filament yarn and a method for producing the same. [Structure] Stretching under conditions that simultaneously satisfy the following formulas,
, And the relaxation heat treatment is performed under the condition that the equations are simultaneously satisfied. DR ₁ = MDR × (0.4 to 0.5)> 1.0DR ₂
= 1.03 to 1.40 HR ₁ = Tg to (Tg + 20)
℃ HR ₂ <Tc ⁺ RR> 5.0% HP> (HR
₂ +50) ° C. Here, DR ₁ is the draw ratio in the first draw zone, DR ₂ is the draw ratio in the second draw zone, MDR is the maximum draw ratio measured at a preheating temperature of 85 to 90 ° C., and HR ₁ is 1.
The surface temperature of the take-up roller in the second drawing area, HR ₂ is the surface temperature of the take-up roller in the second drawing area, RR is the relaxation rate in the relaxation heat treatment area, HP is the relaxation temperature in the relaxation heat treatment area, and Tc ⁺
Is the crystallization temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester filament yarn having a spontaneous stretching property and a method for producing the same. INDUSTRIAL APPLICABILITY The polyester filament yarn of the present invention can be provided as a filament-mixed yarn in combination with a highly shrinkable filament yarn, and can provide a woven or knitted fabric having a novel texture, which is excellent in bulkiness, soft and rich in swelling feeling.

[0002]

2. Description of the Related Art Woven and knitted fabrics using different shrinkage filament mixed fiber yarn are marketed under the name of "new synthetic fiber" as filament yarn having a texture that exceeds silk. However, in recent years, consumers are demanding a higher quality texture, that is, a higher swelling feeling and a new texture, and it is necessary to increase the difference in shrinkage between the high-shrinkage component and the low-shrinkage component constituting the filament mixed fiber Is required. As a method of increasing the shrinkage difference, there are a method of increasing the shrinkage rate of the high shrinkage filament yarn and a method of decreasing the shrinkage rate of the low shrinkage filament yarn. Regarding the former, it is effective to increase the addition amount of the above-mentioned copolymerization component, but the obtained polymer has a low crystallization rate, fusion between pellets in the drying process, and shrinkage of the woven or knitted fabric in the dyeing and finishing process. There are many problems such as a decrease in yield as a product. In addition, increasing the shrinkage ratio of the high shrinkage filament yarn causes the entire woven or knitted fabric to shrink, which tends to make the fabric feel harder. On the other hand, as a method for reducing the shrinkage ratio of the latter low shrinkage filament yarn, a filament yarn having a shrinkage ratio lower than that of the high shrinkage component and desirably having the property of extending is required.

Regarding the polyester filament yarn having such a spontaneous elongation performance, Japanese Patent Publication No. 41-1205
No. 2, in which a filament yarn having a crystallinity of 35% or less obtained by melt spinning / drawing a polyethylene terephthalate polymer is heat-shrinked by 20% or more,
A polyester filament yarn which is spontaneously elongated by the subsequent heat treatment is disclosed. In addition, Japanese Examined Japanese Patent Publication No. 63-461
In Japanese Patent Publication No. 67, a filament yarn is proposed, in which a polyester unstretched filament yarn is shrink-heat treated at a glass transition temperature or higher and then stretched at a temperature not higher than the glass transition temperature, so that the filament yarn has a high boiling water shrinkage ratio but is spontaneously stretched by reheat treatment Has been done. Further, in Japanese Patent Laid-Open No. 3-193948,
Highly oriented unstretched filament yarn having a birefringence Δn in the range of 20 to 90 × 10 ⁻³ is subjected to dry heat treatment in the temperature range of 125 to 145 ° C. under low tension, and then 1.3 at a temperature of Tg or higher. A method for producing a spontaneously stretched filament yarn in which a drawing heat treatment is performed twice or more is disclosed.

[0004]

However, the spontaneously extensible filament yarn obtained by these methods is a filament yarn which shrinks under moist heat and spontaneously elongates by the subsequent dry heat treatment. Even when such a filament yarn is mixed with a high shrinkage filament yarn and woven or knitted with excellent bulkiness, the woven or knitted fabric shrinks under moist heat, so that stains are likely to occur and the quality of the woven or knitted fabric is degraded. Alternatively, such a spontaneously extensible filament yarn must be first shrunk under moist heat and then mixed with the high shrinkage filament yarn. Therefore, there has been a demand for filament yarns that expand under moist heat (that is, during boiling water treatment).

[0005]

[Means for Solving the Problems] That is, the first gist of the present invention is that when the elongation percentage during boiling water treatment is 0 to 5%, the filament yarn that has been subjected to boiling water treatment is subsequently subjected to dry heat treatment at 130 ° C. or higher. In addition, a spontaneously stretchable polyester thick and thin filament yarn having an irreversible elongation of 1 to 4% and having a thick portion and a thin portion dispersed between the constituent filaments and in the longitudinal direction of the filament yarn. is there.

The second gist of the present invention is the birefringence Δ
Highly oriented unstretched filament yarn of polyester having n in the range of 30 to 70 × 10 ⁻³ was stretched under the conditions that simultaneously satisfy the following formulas, and the thick portion and thin portion were dispersed between the constituent filaments and in the filament yarn longitudinal direction. A method for producing a spontaneously stretchable polyester thick and thin filament yarn, which comprises forming a thick and thin filament yarn, and subsequently subjecting it to a relaxation heat treatment under conditions simultaneously satisfying the formula. DR ₁ = MDR × (0.4 to 0.5)> 1.0 DR ₂ = 1.03 to 1.40 HR ₁ = Tg to (Tg + 20) ° C. HR ₂ <Tc ⁺ RR> 5.0% HP> (HR ₂ +50) ° C. Here, DR ₁ is the draw ratio in the first stage draw zone, and DR ₂ is 2
The draw ratio and MDR in the step drawing zone are preheating temperature 85 to 90 ° C.
HR ₁ is the surface temperature of the take-up roller in the first-stage drawing area, HR ₂ is the surface temperature of the take-up roller in the second-step drawing area, RR is the relaxation rate in the relaxation heat treatment area, H
P is the relaxation temperature in the relaxation heat treatment region, and Tc ⁺ is the crystallization temperature.

The present invention will be described in more detail below. The polyester used in the present invention is a polyester having an intrinsic viscosity [η] in the range of 0.50 to 0.72 and a main repeating unit being ethylene terephthalate.
The cross-sectional shape of the filament yarn according to the present invention may be a round cross section or an irregular cross section.

In the present invention, the elongation rate during boiling water treatment is 0.
When the content is -5%, when mixed with the high-shrinkage filament yarn, the filament-mixed yarn exhibits bulkiness in the dyeing and finishing step and has less dyeing unevenness. In addition, since the thick portion and the thin portion are thick and thin filament yarns that are dispersed between the constituent filaments and in the filament yarn longitudinal direction, long-period extension unevenness in spontaneous elongation is reduced,
The filament yarn expresses a more delicate texture and has less dyeing spots. Furthermore, when the filament yarn treated with boiling water is subsequently subjected to dry heat treatment at 130 ° C. or higher, the filament yarn further exhibits irreversible elongation of 1 to 4%, and becomes a filament yarn exhibiting more bulkiness.

The highly oriented unstretched filament yarn referred to in the present invention is a filament yarn having a birefringence index Δn in the range of 30 to 70 × 10 ^-3 , more preferably a birefringence index Δn. It is a filament yarn in the range of 40 to 60 × 10 ⁻³ . Further, the birefringence Δn in the present invention is a value measured by a polarizing microscope using filament yarns having a circular cross section, and the birefringence Δn of filament yarns having an irregular cross section.
Is a value calculated by the following relational expression from the value of density measured using a density gradient tube. The relational expression is an expression obtained by an approximation method as a linear expression from the relation between Δn and density (ρ) measured for a filament yarn having a round cross section in which Δn is in the range of 15 to 60 × 10 ⁻³ . Δn = 3.33 × ρ−4.44

When the birefringence Δn is lower than 30 × 10 ^-3 , the boiling filament shrinkage of the obtained thick and thin filament yarn is large, and the desired spontaneous elongation characteristic during the boiling water treatment cannot be obtained. The reason for this is not clear, but when a thick filament yarn is used, the orientation of the unstretched portion, which is the thick portion, is too low, so stabilization of the molecular structure in the oriented amorphous portion due to thermal energy during boiling water treatment causes crystallization. It is considered that the structure changes to an amorphous shape instead, and the filament yarn shrinks as a result.

On the other hand, when Δn is larger than 70 × 10 ⁻³ , the maximum draw ratio is low and the draw ratio (D
Since R ₁ ) is 1 or less, the stretching condition for thick filament yarn cannot be obtained, and the relaxation heat set filament yarn becomes an unstretched filament yarn. As a result, the extensibility during dry heat treatment after boiling water treatment is recognized, but there is no spontaneous extensibility during boiling water treatment. In addition, dyeing unevenness due to shrinkage unevenness occurs, resulting in poor dyeing quality.

A highly oriented undrawn filament yarn having a birefringence Δn in the range of 30 to 70 × 10 ^-3 is composed of a room temperature feeding roller and a take-up roller heated to Tg to (Tg + 20) ° C. Stretching is performed between the pair of rollers having a stretching ratio of greater than 1.0 and a stretching ratio set to 40 to 50% of the maximum stretching ratio (MDR) measured at a preheating temperature of 85 to 90 ° C. Results in non-uniform stretching in which the stretching point varies slightly on the take-up roller. As a result, a thick and thin filament yarn in which thick portions and details are dispersed between the constituent filaments and in the filament yarn longitudinal direction is obtained.

This thick and thin filament yarn is subsequently stretched at a draw ratio of 1.03 to at a temperature below the crystallization temperature (Tc ⁺ ).
By performing the tension heat treatment such as 1.40, it is possible to increase the orientation of the thick portion that is the unstretched portion while suppressing the progress of crystallization as much as possible, and make it easy to crystallize in the post-treatment process. The thick filament yarn obtained at this stage has structural strain due to stretching remaining in the details of the stretched portion, and has a boiling water shrinkage of 5 to 7% and no spontaneous stretching performance. The thick and fine filament yarn that has been subjected to this tension heat treatment is subsequently subjected to a relaxation heat treatment at a relaxation rate higher than 5.0% and a temperature higher than (the treatment temperature at the time of the tension heat treatment +50) ° C. The thick filament yarn is relaxed and has a spontaneous stretching property such that the boiling water shrinkage rate is 0 to -5% [a negative value represents elongation]. here,
The stretching step and the relaxation heat treatment step may be performed in one continuous step or in two independent steps. This spontaneously extensible thick and thin filament yarn was treated with boiling water and then
Irreversible elongation of 1 to 4% is recognized by the above dry heat treatment. When the stretching is carried out under a condition outside the range of the stretching conditions, spontaneous stretching performance is not expressed, or even if spontaneous stretching performance is recognized, dispersion of thick parts and details is poor, and dyeing occurs with stains. It becomes inferior in quality.
Further, the filament yarn also has a quality problem in terms of spontaneous elongation characteristics, which is uneven in the longitudinal direction of the filament yarn.

The spontaneously stretchable polyester thick and thin filament yarn of the present invention is usually used after being mixed with filaments. However, as one of the highly shrinkable filament yarns of the filament mixed filament yarns, heat treatment is not performed at the time of stretching, so-called general. Polyethylene terephthalate high shrinkage filament yarn,
Or even more excellent contraction properties isophthalic acid or 2,
A modified polyester filament yarn obtained by copolymerizing 2-bis [4- (2-hydroxyethoxy) phenyl] propane or the like can be used.

[0015]

EXAMPLES The present invention will be described in more detail below with reference to examples. The boiling water shrinkage and dry heat shrinkage in the examples and comparative examples were measured by the following methods.

<Boiling water shrinkage rate> 1/3 per 1 denier
A 10-turn winding cassette having a trial length of 1 m is prepared under a tension of 0 g, and a load of 2/3 g per 1 denier is applied to measure the initial cassette length (L ₀ ). After immersing the skein in boiling water for 30 minutes in the unloaded state, the load is applied again to measure the measurement skein length (L ₁ ), which is calculated from the following equation. Boiling water shrinkage = (L ₀ −L ₁ ) / L ₀ × 100%

<Dry heat shrinkage>: The dry heat shrinkage at 180 ° C. was measured by measuring the boiling water shrinkage and then leaving the measured Kasse sample in an ambient temperature of 180 ° C. for 10 minutes under no load. The measurement length (L ₂ ) is measured and calculated by the following formula. Dry heat shrinkage = (L ₀ −L ₂ ) / L ₀ × 100%

The Tg and Tc of the undrawn filament yarn
The value of ⁺ was measured with a differential scanning calorimeter (DSC220 manufactured by Seiko Instruments Inc.).

Example 1 Polyethylene terephthalate having an intrinsic viscosity [η] of 0.65 was used by using a spinneret in which 72 holes having a hole diameter of 0.2 mm are arranged.
Melt spinning at 0 ° C, winding at 2700 m / min, 12
0d / 72f unstretched filament yarn was produced. The MDR of the obtained undrawn filament yarn is 2.55, Δn =
It was 53 × 10 ⁻³ , Tg = 70 ° C., and Tc ⁺ = 110 ° C. This unstretched filament yarn was stretched and relaxed by heat under the following stretching conditions to produce a thick and thin filament yarn. First stage draw ratio (DR ₁ ) = MDR × 0.41, second stage draw ratio (DR ₂ ) = 1.10 First stage take-up roller temperature (HR ₁ ) = 82 ° C. Second stage take-up roller temperature (HR ₂ ) = 110 ° C. Relaxation rate = 10%, Relaxation temperature = 190 ° C. The boiling water shrinkage rate of this thick filament yarn is -1.1%, 1
The dry heat shrinkage ratio at 80 ° C. was −3.4%, which means that after the boiling water treatment, the dry heat treatment carried out subsequently showed the elongation of 2.3%. The obtained spontaneously stretchable thick filament yarn and a highly shrinkable filament yarn of 75d / 18f produced by using a modified polyester obtained by copolymerizing 8.0 mol% of isophthalic acid were air-blended to obtain 190d / 90f. A filament-mixed yarn was produced, a plain woven fabric was prepared, and after weight reduction and dyeing, a dry heat treatment was carried out at 175 ° C. for 1 minute. The evaluation results of the obtained woven fabric are shown in Table 1. The obtained woven fabric was excellent in bulkiness and had a soft feeling with a feeling of bulging.

[Examples 2 to 8 and Comparative Examples 1 to 6] Thick and thin filament yarns obtained by variously changing Δn, cross-sectional shape, stretching conditions and relaxation conditions of unstretched filament yarns as shown in Table 1. The shrinkage characteristics and the filament-mixed yarn with the high-shrinkage filament yarn were prepared in the same manner as in Example 1, and the woven fabric using this filament-mixed yarn was evaluated for bulkiness and texture. The results are shown in Table 1.

[0021]

[Table 1]

[0022]

According to the present invention constructed as described above, it is possible to obtain a thick and thin filament yarn having no uneven dyeing which is elongated by boiling water treatment and dry heat treatment. When the thick and thin filament yarn is combined with the highly shrinkable filament yarn to form a filament mixed fiber yarn, it is possible to provide a woven or knitted fabric having a novel texture which is excellent in bulkiness, soft and rich in swelling feeling.

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location D02G 3/04 D02J 1/22 M D03D 15/00 J 7199-3B (72) Inventor Kazuhiro Shiozaki Toyohashi, Aichi Prefecture 2-4 Sanyubyo Rayon Co., Ltd., Ushikawadori, Ushikawa, Japan (72) Inventor Junichi Yokoyama 2-2, 4-chome Ushikawadori, Toyohashi, Aichi Toyohashi, Sanyobyo Co., Ltd.

Claims (2)

[Claims] 1. The elongation rate during boiling water treatment is 0 to 5%,
When the filament yarn treated with boiling water was subsequently subjected to a dry heat treatment at 130 ° C. or higher, it showed an irreversible elongation of 1 to 4%, and the chic portion and the thin portion were dispersed between the constituent filaments and in the filament yarn longitudinal direction. Spontaneous stretchable polyester thick and thin filament yarn characterized by being 2. A highly oriented unstretched filament yarn of polyester having a birefringence index Δn in the range of 30 to 70 × 10 ⁻³ is stretched under the conditions of simultaneously satisfying the following formulas (1) to (3), and a thick portion and a thin portion constitute filament And thick filament yarn dispersed in the space and filament yarn longitudinal direction, and subsequently,
A method for producing a spontaneously stretchable polyester thick filament yarn, characterized in that a relaxation heat treatment is carried out under the condition of simultaneously satisfying the formula. DR ₁ = MDR × (0.4 to 0.5)> 1.0 DR ₂ = 1.03 to 1.40 HR ₁ = Tg to (Tg + 20) ° C. HR ₂ <Tc ⁺ RR> 5.0% HP> (HR ₂ +50) ° C. Here, DR ₁ is the stretching ratio in the first stage stretching region, DR ₂ is the stretching ratio in the second stage stretching region, MDR is the maximum stretching ratio measured at a preheating temperature of 85 to 90 ° C., HR ₁ Is the surface temperature of the take-up roller in the first drawing area, HR ₂ is the surface temperature of the take-up roller in the second drawing area, RR is the relaxation rate in the relaxation heat treatment area, HP is the relaxation temperature in the relaxation heat treatment area, Tc ⁺ Is the crystallization temperature.