JPH04352814A - Polyether ester-based elastic fiber - Google Patents

Abstract

PURPOSE:To obtain polyether ester-based elastic fiber, producible with good operating efficiency and excellent in elastic recovery ratio. CONSTITUTION:Elastic fiber is composed of a composition prepared by adding 1-10wt.% polyolefin such as polyethylene or polypropylene to a polyether polyester-based elastomer containing polybutylene terephthalate as a hard segment and polytetramethylene glycol as a soft segment.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to polyetherester elastic fibers that are flexible and highly elastic.

0002

[Prior Art] Polyurethane elastic fibers called spandex are widely used in sports clothing and other products in combination with nylon. It also has the problem of being expensive.

[0003] For this reason, polyetherester elastic fibers have been developed.
As disclosed in Japanese Patent No. 911, a material made of an elastomer having polybutylene terephthalate (PBT) as a hard segment and polytetramethylene glycol (PTMG) as a soft segment is well known.

However, as described in, for example, Japanese Patent Publication No. 63-31581, this elastomer has high adhesiveness and causes the so-called blocking phenomenon in which the filaments stick during the spinning stage. When manufacturing, this poses a major problem in operability. In order to solve this problem, attempts have been made to make the cross section of the filament irregular, but this has not provided a fundamental solution.

[0005]

[Problems to be Solved by the Invention] The present invention is an elastic fiber mainly composed of an elastomer with PBT as a hard segment and PTMG as a soft segment, which does not stick between filaments during spinning, and is easy to operate. The object of the present invention is to provide an elastic fiber that can be manufactured with good elasticity and has excellent elastic properties.

[0006]

[Means for Solving the Problems] The present invention solves the above problems, and uses PBT as a hard segment and PBT as a hard segment.
The gist is a polyetherester elastic fiber made of a composition in which 1 to 10% by weight of polyolefin is blended with a polyetherester elastomer having TMG as a soft segment.

The present invention will be explained in detail below. The polyetherester elastomer (hereinafter referred to as
It's simply called elastomer. ) is a copolymer consisting of PBT (including polyester containing PBT as the main component) and PTMG (including polyether containing PBT as the main component).

As is well known, PBT is a general-purpose polyester containing terephthalic acid as a dicarboxylic acid component and butanediol as a diol component, and contains small amounts (about 10% by weight) of isophthalic acid, adipic acid, ethylene glycol, etc. ) may be copolymerized.

[0009] Furthermore, PTMG may be copolymerized with a small amount (up to about 10% by weight) of ethylene glycol, diethylene glycol, trimethylene glycol, or the like. In terms of spinnability and elastic properties, PTMG preferably has a number average molecular weight of 1000 to 3000.

[0010] The copolymerization ratio of PBT and PTMG is 90~
20:10-80, preferably 80-40:20-60
A suitable weight ratio of Within this range, the fiber will have a melting point suitable for melt spinning and at the same time exhibit an excellent elastic recovery rate. In addition, the elastomer was prepared using an equal weight mixture of tetrachloroethane and phenol as a solvent at a temperature of 20°C.
It is preferable that the relative viscosity measured by 1.3 to 3.0 is used.

[0011] The elastomer may contain a small amount of a coloring agent, an antioxidant, a heat resistant agent, a matting agent, etc., if necessary.

[0012] If such an elastomer is melt-spun as is, the filament has adhesive properties, which causes problems such as poor unwinding and inability to uniformly draw the filament during subsequent drawing. do. However, it has been found that adding a small amount of polyolefin to the elastomer solves this problem.

[0013] Examples of the polyolefin herein include high-density polyethylene, linear low-density polyethylene, polypropylene, and ethylene/propylene copolymers. The molecular weight, melt viscosity, etc. of the polyolefin are not particularly limited, but are determined by the viscosity of the elastomer used, the copolymer composition, etc. That is, when the PBT content is high, a relatively high molecular weight polyolefin can be used because the melting point of the elastomer is high;
If the MG content is high, the melting point will be low, so a relatively low molecular weight polyolefin must be used.

The amount of polyolefin added must be 1 to 10% by weight. The amount added depends on the characteristics of the target fiber and the copolymerization ratio of PTMG, but if it is less than 1% by weight, the effect of reducing the adhesion between filaments will be poor, and if it exceeds 10% by weight, the resulting fiber will be The elastic recovery rate will be poor.

[0015] The elastomer and polyolefin can be blended in any step. For example, it is possible to add the polyolefin to the polymerization pot and blend it after the polymerization of the elastomer is completed, or to chip the elastomer and then blend the chipped polyolefin. This is more convenient from an operational and cost standpoint. In addition, when blending and spinning chipped polymers, it is preferable to use a spinning machine equipped with a so-called static mixer because the kneading effect is good.

The fiber of the present invention can be produced by melt-spinning and drawing the polymer blended by the above method in a conventional manner. For example, using an extruder type melt spinning device,
It is melted at a temperature 80° C. higher, discharged from a spinneret, cooled and solidified, and then wound up as an undrawn yarn using rollers. Next, the undrawn yarn is drawn without heating or using a heated roller depending on the composition of the elastomer, and if necessary, subjected to a relaxing heat treatment.

The properties of the fibers of the present invention are not particularly limited, but they usually have a strength of 0.7 g/d or more, which is not a problem in practice, and an elastic recovery rate of 85% at 100% elongation.
It exhibits excellent elastic properties as described above. Furthermore, since the fibers of the present invention do not have problems with adhesion, their cross-sectional shape is not a particular problem, and a normal round cross-section is acceptable, but an irregular shape may be used when used in fields where gloss is required. . moreover,
Although the fineness and the number of filaments are not particularly limited, the single yarn fineness is usually 0.5 to 50 d and the number of filaments is about 10 to 200.

The elastic fiber of the present invention can be used in a wide range of clothing fields, mainly sports clothing in combination with nylon, and can also be used as short fibers or nonwoven fabrics.

[0019]

[Examples] Next, the present invention will be specifically explained with reference to Examples. In addition, the method of measuring the characteristic values in the examples is as follows. (1) Melt index Determined according to ASTM-D-1238(E). (2) Melt flow rate Determined according to ASTM-D-1238 (L). (3) Strength and elongation of drawn yarn Using autograph, sample length 20 cm, tensile speed 20 c
The measurement was performed under the conditions of m/min. (4) Elastic recovery rate According to JIS L-1013 A, the recovery rate was determined from the recovery rate at 100% elongation under the conditions of a sample length of 20 cm and a tensile speed of 20 cm/min.

Example 1 An elastomer containing PBT and PTMG having a number average molecular weight of 2000 in a weight ratio of 45/55 was produced by a conventional method. This polymer had a melting point of 183°C and a relative viscosity of 2.04. This elastomer has a melt index of 26g/1
0 minute linear low-density polyethylene (PE) at the ratio shown in Table 1, and melt-spun at a spinning temperature of 210° C. using an extruder-type melt-spinning device.

At this time, a spinneret having 36 spinning holes with a diameter of 0.3 mm was used, and the spun yarn was heated at 20° C. from the lateral direction.
After cooling and solidifying, an oil agent is applied, and the
The undrawn yarn was wound up at a speed of 0 m/min.

The obtained undrawn yarn was fed to a drawing machine, pretensioned, and then drawn 2.4 times between rollers at room temperature.
Next, the yarn was subjected to relaxation heat treatment at a relaxation rate of 40% while being brought into contact with a hot plate at 100° C., and then wound at a speed of 100 m/min to obtain an elastic yarn of 75 d/36 f. Table 1 shows the operability during spinning, the unwinding property of the undrawn yarn during drawing, and the characteristic values of the drawn yarn.

[0023]

[Table 1]

As is clear from Table 1, No. 1, which is an example of the present invention. In Examples 2, 3, and 4, elastic yarns with good spinning operability and excellent elastic recovery were obtained. On the other hand, No. 1, which is a comparative example in which PE is not added. In No. 1, the undrawn yarn had poor unwinding properties due to adhesion between the filaments, resulting in frequent breaks and could not be drawn. In addition, No. 1, which is a comparative example in which the amount of PE added is too large. In No. 6, fuzz was generated during spinning, and the elastic recovery rate of the obtained elastic yarn was 80% or less, indicating poor elastic properties.

Example 2 Using the same elastomer as in Example 1, 5% by weight of polypropylene with a melt flow rate of 30 g/10 min was blended with the elastomer, and the yarn was spun under the same conditions as in Example 1. A 36f elastic yarn was obtained. Both spinning and drawing can be carried out without any operational problems, and the obtained elastic yarn has a strength of 1.4 g/d, an elongation of 510%, and an elastic recovery rate of 92.
%Met.

[0026]

[Effects of the Invention] The elastic fiber of the present invention has the characteristics that there is no sticking between filaments during spinning, it can be manufactured with good operability, and it has an extremely good elastic recovery rate. , which can be suitably used mainly in the field of sports clothing.

Claims (1)

[Claims] 1. A polyether ester elastic fiber comprising a polyether ester elastomer containing polybutylene terephthalate as a hard segment and polytetramethylene glycol as a soft segment, mixed with 1 to 10% by weight of a polyolefin.