JPS5936722A - Conjugate spinning - Google Patents

Abstract

PURPOSE:To obtain eccentric conjugate yarn providing bulky clothes, by subjecting a polyethylene terephthalate (PET) containing a specific polymer and anothe PET not containing it to melt spinning from the same spinneret holes at a specific take-up speed, and crimping it by heat-treatment. CONSTITUTION:A PET containing a polymer to become a thermotropic liquid crystal and another PET not containing it are taken off form the same spinneret holes at >=4000m/min in a temperature range of melt spinnable properties of PET, to give the desired conjugated yarn. A copolychloro 1,4-phenyleneethylenedioxy 4,4'-dibenzoate/terephthalate copolymer, etc. may be cited as the polymer to become a thermotropic liquid crystal, and the blending ratio of PET is preferably 1-10wt%. EFFECT:Providing bulky yarn without requiring twisting and crimping process.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on melt spinning of polyethylene terephthalate. 11. The present invention relates to a method for producing a composite fiber composed of two components having different heat shrinkage rates depending on the presence or absence of an added polymer.

The conjugate fiber produced by the production method of the present invention develops crimp by heat-treating it, and a bulky fabric is obtained by heat-treating a fabric using this conjugate fiber.

Conventionally, false twisting has been mainly used to manufacture bulk yarn, but high-speed and large-sized false twisting machines have been required to increase productivity.

The present inventors searched for a method that can provide bulk yarn without the need for false twisting and crimping steps, and discovered the present invention.

In recent years, with the development of spinning technology, various new findings regarding high-speed spinning of polyethylene terephthalate have been obtained.

In particular, many studies have already been conducted on phenomena such as a decrease in thermal shrinkage in the region where the take-up speed exceeds 4000 m/min, high crystallinity and high orientation of the outer fiber layer, and low crystallinity and low orientation of the inner fiber layer. It is emitting light.

On the other hand, if a certain type of polymer that becomes Samotrovik liquid crystal is added, the heat shrinkage rate of polyethylene terephthalate fiber obtained by high-speed spinning is reduced.

The phenomenon of being significantly suppressed was reported in the Special Publication No. 57-11211.
It is clarified by the number.

Certain polymers become liquid crystals when heated to a temperature range characteristic of the polymer, or when heated and subjected to additional shear forces. This type of liquid crystal is called a thamotropic liquid crystal. Samotropic liquid crystals can be optically identified by, for example, heating and melting a nine-polymer between the polarizing plates of a polarizing microscope and measuring the amount of transmitted light.

The test method for thymotropic liquid crystal behavior of polymers is B.
.

P. 1507207.

The composite fiber according to the production method of the present invention can be obtained by adding or not to polyethylene terephthalate a polymer that becomes Samotropic liquid crystal during high-speed spinning of bo-1-ethylene terephthalate. It is based on a combination of polymer blends with widely different heat shrinkage rates and polymerization bases. That is, the present invention.

ill Polyethylene terephthalate containing a polymer that forms a samotropic liquid crystal, and polyethylene terephthalate that does not contain a polymer that forms a samotropic liquid crystal, within a temperature range that allows polyethylene terephthalate to be melt-spun, at a distance of 4,000 m from the spinneret hole. Composite spinning method characterized by obtaining eccentric composite fibers by taking a bow at a drawing speed of 1/min or more (2) Polymer strength to form samotropic liquid crystal; ′
-dibenzoate/terephthalate or 6-oxy-
Claim No. 1, characterized in that it is a copolymer of a 2-naphthoyl moiety and a p-oxi dibenzoyl moiety (
Composite spinning method according to item 11.

It is related to.

The polyethylene ratio of the polymer that becomes the samotropic liquid crystal is
4000. In the drawing speed range of around m/min or higher, it decreases significantly as the drawing speed increases.

However, in the range of take-up speeds of about 4000 m/min or more, the reduction in boiling water shrinkage of the spun fibers is significantly suppressed by the addition of the polymer that becomes Samotrovik liquid crystal.

On the other hand, 4000. In the range of draw-off speeds as low as m/min, spun filaments of polyethylene terephthalate containing polymers become samotrovic liquid crystals.

It exhibits a lower heat shrinkage rate than spun filaments of polyethylene terephthalate that do not contain it. Also.

In the composite spinning method of the present invention, the take-up speed is 4000 m.
If the speed is changed to a speed lower than 1/min, the spun filaments obtained will have a low degree of orientation of polymer molecules and will not have sufficient strength for practical use, so that the objects of the present invention will not be satisfied.

Therefore, the take-up speed range in the composite spinning method of the present invention is
400'Om/min or more is suitable.

Examples of polymers that can be used as Samotrovik liquid crystals include:
copolychloro1,4-phenyleneethylenedioxy4,
Examples include 4'-dibenzoate/terephthalate or copolymers of 6-oxy-2-naphthoyl and p-oxybenzoyl moieties.

The mixing ratio of the polymer forming the samotropic liquid crystal to polyethylene terephthalate is preferably 1 to 10 wt%.

The temperature range in which the polymer that becomes thamotropic liquid crystal exhibits the liquid crystal state is: - Melt spinning of polyethylene terephthalate o
It is preferable that the J function humidity and temperature ranges overlap by 5°C or more.

Table 1 shows the length ratio after boiling water shrinkage at nine different withdrawal speeds for three polymers added to polyethylene terephthalate.

In these experiments, each of the six polymers was 6 wt%
with polyethylene terephthalate at a concentration of 280'
0 and kneaded using a screw extruder.

It was extruded using a guttet with a diameter of 1 ann, water-cooled, and cut. The three types of polymers were as follows.

Polymer 1 Copolychloro 1,4-phenyleneethylenedioxy 4,4'-dibenzoate/terephthalate, this polymer was prepared in a 0.5% solution in a solvent of 50% trifluoroacetic acid and 70% dichloromethane.

It had an intrinsic viscosity of 54 an"7g at 25°C. This polymer melts in the temperature range of 210-220°C.

Using a polarizing microscope, it was observed that the liquid crystal became a samotropic liquid crystal up to 520°0. This temperature range force) et al.

This polymer is suitable for melt spinning with polyethylene terephthalate.

Polymer 2 6-oxy-2 molar ratio 60%/40%
- a copolymer of naphthoyl and p-oxybenzoyl moieties, which had an intrinsic viscosity of 560 cm"7 g at 60°C in a 0.1% solution of pentafluorophenol. , it was observed by polarizing microscopy that it became a samotropic liquid crystal.

Polymer 3 11 N s / r++2 at 1ON/m'
polyethylene with a melt viscosity of .

All three polymer formulations and blank polyethylene terephthalate were melt spun at 100 g/hr/hole in a 0.2 + nm diameter spinneret hole and cooled in ambient air without special quenching equipment. After cooling, the obtained filaments were taken off at various speeds, and the boiling water shrinkage rate s (%) was measured.

As a guideline for bulk quality directly related to bulk obtained by thermal processing of composite yarns of polyethylene terephthalate filaments containing a polymer that becomes samotropic liquid crystal and polyethylene terephthalate filaments not containing the same, boiling water shrinkage of both is used. The subsequent length ratio R was calculated. It is considered that the larger R deviates from 1, the greater the bulkiness developed by heat-treating the composite fiber.

100 - El where S is the boiling water shrinkage of the polyethylene terephthalate filament without added polymer.

In the experimental example, the addition of 3% polyethylene, which does not result in a samotropic liquid crystal, has the greatest effect at a take-up speed of 450.
Even at 0 m/min, the value of R deviated only slightly from 1.

On the other hand, in Experimental Example 1 or 2, copolyqualo 1,4-phenyle/ethylenedioxy 4,4'-dibenzoate/terephthalate or 6-oxy-2-naphthoyl with a molar ratio of 60%/40% was used to form a samotropic liquid crystal. The addition of a copolymer of moieties and p-oxybenzoyl moieties
It can be seen that the value of R4 deviates significantly from 1 at a take-up speed of about 4000 m/min or more.

Table 1 Length ratio R after contraction in boiling water Note) Experimental example 1: Polyethylene terephthalate decapolymer (1) Experimental example 2: Polyethylene terephthalate decapolymer (2) Experimental example 5: Polyethylene terephthalate decapolymer (3) ) It is theoretically conceivable to apply the composite fiber manufacturing method of the present invention to other polymers such as polyhexamethylene adipamide instead of polyethylene terephthalate, but in this case, the heat shrinkage rate is higher than that of polyethylene. significantly lower than that for terephthalate. Therefore, the composite fiber manufacturing method of the present invention is particularly suitable for polyethylene terephthalate.

Thread In the composite r produced by the production method of the present invention, it is preferable that polyethylene terephthalate added with a polymer that becomes a samotropic liquid crystal is composited at a ratio of 5 to 95%, and a more preferable range is 20 to 80%. It is. If the proportion of the polymer blend in the composite yarn is too large or too small, the bulk quality will deteriorate.

The composite fiber produced by the production method of the present invention may be further stretched. Further, a false twisting process may be applied. By heat-treating the conjugate fiber produced by the present invention as it is or after knitting it as a cloth, it is now possible to obtain a bulk or parnod fabric.

Typical cross-sectional structures of the eccentric conjugate fiber produced by the production method of the present invention are a laminated type and an eccentric core-sheath type as schematically shown in FIG. Heat treatment causes crimp due to the different thermal shrinkage rates of asymmetrically arranged polymers and polymer blends. Such conjugate fibers may have a cross section other than circular, and may be used in the form of either long fibers or short fibers.

For the heat treatment to increase the bulk of the conjugate fiber according to the present invention and the fabric using the same, methods such as immersion in high-temperature water, heating with a hot roller, or infrared rays may be used.

When a fabric using composite fibers according to the production method of the present invention is heat-treated to produce a bulky fabric, a form with a voluminous feel can be made to appear only after the heat treatment after nine weavings.

Note that the principle of the present invention can also be applied to a sea-island composite fiber in which two types of island components having a cross section as shown in FIG. 2 are arranged.

Next, nine embodiments according to the present invention will be shown.

Examples In these experiments, two polymers were heated to 280° C. with polyethylene terephthalate at a concentration of 5 wt% each, kneaded in a screw extruder, extruded into guts with a diameter of 1 cm, cooled in water, and cut. The two polymers are Polymers 1 and 2 described above.

The polymer blends in which the above-mentioned polymers (1), (2) are added to polyethylene terephthalate are hereinafter respectively referred to as polymer blends fl)i2). Polyethylene terephthalate to which nothing was added and Polymer Blend 1 or 2 were composite-spun into a bonded type or an eccentric core-sheath type as shown in Table 2, and the resulting four types of filaments were immersed in boiling water. . All four types of filaments were crimped and formed a direct line of elasticity.

Table 2 Structure and components of composite yarn However, the proportion of the polymer blend in the composite fiber is 50 wt% for the bonded type composite fiber and 40 w, t% for the eccentric core-sheath type composite fiber.

In addition, the warp is a 150 denier, 48 filament polyethylene terephthalate yarn (registered trademark "Tetron").
), and the wefts were filament yarns made of 4B filaments of the laminated composite fibers used in Example 1 or 2, to produce two types of plain-woven fabrics. When these were passed through boiling water, the woven structure in the transverse direction became dense, and a bulky fabric with elasticity and volume was obtained.

It should be noted that the above embodiments are only some of the examples to which the present invention is effective, and are not intended to narrow the interpretation of the scope of the present invention.

[Brief explanation of the drawing]

Figures 1 and 2 are schematic diagrams of a cross section perpendicular to the fiber axis of a composite fiber according to the present invention. The portion is polyethylene terephthalate without such added polymers. Patent Applicant Toshi Co., Ltd. No. J Figure L A “i” 43 Lu (inside 7° 11: no change) No. 2
Figure Procedure Supplement Jl, 11 (Method) % Formula %) 2. Name of Invention Composite Spinning Method 4. Date of Amendment Order A.1 November 301, 1982
- eye opening) 5. Due to the increase in invention due to amendment',
C6,? lIi Positive object Figure 7b1 7. Contents of correction (1) Figure 2 is attached as shown in the attached sheet.

Claims (2)

[Claims] (1) Within the temperature range that allows polyethylene terephthalate to be melt-spun, polyethylene terephthalate containing a polymer that forms a samotropic liquid crystal, and polyethylene terephthalate that does not contain a polymer that forms a samotropic liquid crystal, are spun 4000 m from the same spinneret hole. A composite spinning method characterized in that eccentric composite fibers are obtained by taking off at a take-off speed of /min or more. (2) The polymer that becomes the samotropic liquid crystal is copolychloro1,4-phenyleneethylenedioxy4,4'-
Dibenzoate/terephthalate or 6-oxy-2
-Claim No. (1) characterized in that it is a copolymer of a naphthoyl moiety and a p-oxybenzoyl moiety.
Composite spinning method described in section.