JPS6189324A - Polyester yarn and its production - Google Patents

Abstract

PURPOSE:To obtain polyester yarn having promoted crystallization of orientation, by adding a small amount of polyethylene to polyester, by subjecting the polyester to melt spinning, cooling it, and drawing it by a draw roller at a specific speed. CONSTITUTION:A polyester comprising ethylene terephthalate as a main constituent unit is blended with 0.5-30wt%, preferably 1-25wt% based on the polyester of polyethylene, and the polyethylene-containing polyester is subjected to melt spinning. Then, the prepared spun yarn is cooled, the speed of the draw roller is made in a range shown by the equation (V is drawing speed; W is amount of polyethylene added based on the polyester; IV is intrinsic viscosity of polyester part of the yarn), the yarn is drawn by the draw roller, to give the aimed yarn having >=35Angstrom apparent crystal size ACS100 of (100) plane.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to polyester fibers and the like! The present invention relates to a conventional method, and more particularly to an oriented crystallized polyester fiber and a method for producing the same.

(Prior Art) Polyester fibers, particularly polyethylene terephthalate fibers, are widely used for clothing and string materials due to their excellent properties. This polyester fiber is usually
It cannot be used after undergoing the processes of melt spinning, stretching, and heat setting. Due to recent advances in spinning technology, the take-up speed during melt spinning has increased from the conventional 1000 m/min to 1500 sif/min to over 2000 m/min or 3000.17 m/min.
It became possible to increase the take-up speed from 1/min to 4000+# 7 minutes or more.

In particular, intermediately oriented undrawn yarn (POY) obtained at a take-up speed of 2500 tn/min to 4 ooom/min has been rapidly developed for use in recent years, and is becoming the mainstream of yarn spinning technology.

On the other hand, this polyester fiber has the property of being less likely to crystallize than fibers of other polymers, especially polyethylene, polypropylene, polyamide, etc., but as the take-up speed during spinning increases, the molecular chains As a result, crystallization occurs at speeds above a certain level.This tendency is observed in polyester used for clothing when
This becomes noticeable when the take-up speed is 00 m/min or higher.

Regarding the structure of fibers that are oriented and crystallized during spinning (oriented crystallized yarn), see Journal of the Japan Institute of Textile Technology (Textiles and Industry) No. 38.
As seen in Vol. 11, No. P-514, various studies have been conducted on Iφ, and it is known that it has a unique t1 and i structure, which is different from the structure obtained from low-speed spinning and drawing. The fibers are oriented and crystallized during such high-speed spinning and have a unique fine structure.

(Problems to be Solved by the Invention) In all of the above conventional techniques, in order to obtain oriented crystallized yarn, at least 4
000-500 Q tn If a take-off speed of 7 minutes is required and the take-off speed of 40007F+/min is not met, it is extremely difficult to obtain oriented crystallized yarn with a large crystal size AC3100 using a spinning-winding system. Met.

In addition, when producing oriented crystallized yarn using conventional technology, a take-off speed of 4,000 to 5,000 m/min or more is required, resulting in problems in stable operation and rough spinning, drawing, and post-processing. Considering unification, qualitatively large r1
[Means for solving the problem] The above problem is solved by the following.

(1) In a polyester whose main repeating unit is ethylene terephthalate,
．． 5 to 30 fR amount%, preferably 1 to 25 weights! lc%
(2) The polyethylene-containing polyester satisfying the above (1) is melt-spun, cooled, and taken off with a take-off roller. A L, the take-up speed of the take-up roller (Vm/
This can be solved by setting the value (minute) to the range of formula (1) below, preferably the range of formula (2) below.

■≧7600-7262. IXIV'-47-50XW
-(1)■≧7'600-7262.1 X IV'・
47-44XW... (2) Here, take-up speed i2J
In the case where 'V does not satisfy the above formula (1) by one degree', oriented crystallization does not occur during spinning, and even if oriented crystallization is performed by coll-stretching the obtained spun yarn, the crystal size Fibers with sufficiently large AC3+oo cannot be obtained.

In the present invention, when adding VC polyethylene in polyester, the method of adding L2 is not limited to 44ν, and a chip blending method of mixing polyester chips and polyethylene chips may be used, or A WxNk melt blend method may be used, and any method that does not adversely affect spinnability etc. may be used.

In the present invention, polynisdel having ethylene derephthalate as its main constituent unit is one in which 85 or more molar units of repeating units are composed of ethylene terephthalate, and in particular terephthalic acid or its invasive agent and ethylene. The target is polyethylene terephthalate prepared from glycol or 211° ethylene peroxide, but in addition to terephthalic acid or its functional six monomers as the acid component, less than 15 moles, preferably 10 moles. Isofu less than 4
acid, adipic acid, sepacic acid, azelaic acid, naphthalic acid, P-oxybenzoic acid, 2,5-dimethylterephthalic acid, bis(P-carboxyphenoxy)ethane, 2
．． Adding 6-f phthalene dicarphonic acid, 3,5-di(carbomethoxy)benzenesulfonate or a functional derivative thereof, or adding diethylene glycol, glopyre/glycol, etc. in addition to ethylene glycol as a glycol component. , 4-butanediol, 1,4-
A copolymer containing a dihydric alcohol such as hydroquine methylcyclohexane may also be used. For example, a copolymer containing aromatic polyphosphonate to impart flame retardancy may also be used. Furthermore, antioxidants, matting agents, colorants, dyeability improvers, flame retardancy improvers, antistatic agents, etc. may be added to these polymers.

The polyethylene referred to in the present invention is not particularly limited in terms of density, molecular weight, etc., and whether it is low-density polyethylene or high-density polyethylene does not affect the effect of the present invention, but if the molecular weight is extremely If the melt index is low, problems such as thread breakage will occur, so the melt index is preferably 70 or less, more preferably 50 or less. The fiber of the present invention obtained by reducing β0 has a content of 0.5 to 30ii (%, preferably 1 to 25% by weight, more preferably 5% by weight, based on the polyester) in a polyester having ethylene terephthalate as a main structural unit. Contains ~25% by weight of polyethylene, and (100) of the polyester portion
Apparent crystal size of the surface A CS +o.

It is a polyester fiber having a unique microstructure with a diameter of 35 Å or more, preferably 45 Å or more, and more preferably 50 Å or more. It should be further noted that the fibers of the present invention are
IP has a lower specific gravity than conventional oriented crystallized polyester fibers! It is one of the symptoms.

Here, if the content of polyethylene is less than 0.5% by weight relative to polyester, oriented crystallization will be insufficient.
It becomes difficult to satisfy the apparent crystal size of the (100) plane as intended in the present invention. On the other hand, if the amount of polyethylene exceeds 30% by weight, the yarn quality, particularly the strength and elongation, will be markedly reduced, which is not preferable.

(Function) In the region of low spinning take-off speed, where it was difficult to obtain oriented crystallized yarn with conventional technology, it is possible to
The present inventors provide a method for obtaining oriented crystallized yarn with a large crystal size ACS 100 by using a small amount of polyethylene as an oriented crystallization promoter in polyester.

Although it is not clear why the addition of polyethylene can promote oriented crystallization, the present inventors think as follows. Crystallization during spinning, especially its ffJ
IN( is considered to be caused by nucleation and growth. Nucleation largely depends on the orientation of molecules, and in the present invention, the degree of molecular orientation increases due to some action between polyester and polyethylene, resulting in a faster nucleation rate. However, it is thought that the mobility of the molecular weight of polyester was increased by the addition of polyethylene, the growth rate increased, and oriented crystallization was promoted due to fc.

(Examples) The present invention will be described in detail below with reference to Examples, but the present invention is not limited to these Examples. Note that the characteristics and measurement methods used in the evaluation of the present invention are as follows.

Crystal size (AC8)> Apparent crystal size A of 100 sides of the fiber as referred to in the present invention
CS roo is a crystal calculated using the 5herrO formula from the half value of the diffraction intensity of the equatorial diffraction curve in a wide-angle X-ray diffraction diagram [for details, refer to "X-ray Crystallography" published by Maruzen Co., Ltd. (supervised by Isamu Nita)] The formula for the size 5herrer is expressed by the following formula.

0.9λ Apparent crystal size (AC8’) = □ 4F=7°. 80 <Dry heat shrinkage rate at 160℃> Measured according to JIS-L-1013 (1981).

<Intrinsic viscosity (IVY>) A mixed solution consisting of 60% by weight phenol and 40% by weight ethane is used. The polymer is heated to about 90°C, dissolved while stirring, and 30% by weight is used using an Uperose viscometer. ℃
Measure with.

Intrinsic viscosity is the natural logarithm of the ratio of solution viscosities in grams of polymer per 100 g of solution, and is expressed as the limit value at which the value obtained by dividing the ratio by the solidity of the polymer solution approaches zero concentration.

<Specific Gravity> A density gradient tube made of n-hebutane and carbon tetrachloride was prepared, and a well-defoamed sample was placed in the density gradient tube whose temperature was controlled at 30°C ± 0.1°C for 5 hours. After leaving the sample position in the density gradient tube, the value read on the scale of the dense ash gradient tube is converted to the specific gravity value from the density gradient tube scale using a cotton semi-glass float - specific gravity calibration graph. measurement. As a general rule, read specific gravity values to four decimal places.

Example 1 Chips of polyethylene terephthalate with an intrinsic viscosity of 0.60 were mixed with chips of low-density polyethylene with a melt index of about 3.5 as shown in the first flame, and melted and glued. After, hole diameter 0,23+n, hole 2
The material was discharged using a No. 4 spinneret at 285° C. and at a single-hole discharge rate of 1.517 minutes. After cooling and assimilating the entire yarn by blowing air at 22°C from the 4M direction, the yarn quality of each fiber was determined at the respective take-up speeds shown in Table 1. Fruit of the first garment a・'a
, f.

1 to 19. However, in each case, polyethylene terephthalate was used as Ivfijo 57.

As is clear from Table 1 below, the rectangle obtained by the method of the present invention had a large AC3+oo of 35 Å or more.Experiment A I of Example 1, Experiment Using the fibers prepared by Horse 7 and Experimental Muscle 19, the heating roller temperature was 82.5°C and the hot plate temperature was 1'.
, ffi The sample was drawn at a temperature of 110° C. using a drawing medium such that the residual elongation of the drawn yarn was 25%. The characteristics of Shinoki yarn are shown in Table 2, Mitsuya 20, Mitsuyakutu 21, and Mi9A22.

As can be seen in Table 2, the fibers of experimental stripe 1 and experimental thickness 19 obtained by a method other than the method of the present invention, even after further stretching, do not maintain the intended crystal size AC8+o.

I can't get rid of it.

Example 3 Using the drawn yarns of the experimental stripes 21 and 22 in Example 2, a fixed-length heat treatment was performed at a temperature of 220° C. for the respective treatment times shown in Table 3. The characteristics of the obtained heat treatment system are shown in Experimental lines 23 to 26 in Table 3.

Table 3 As shown in Table 3, the properties of the yarn after drawing and heat treatment of the fiber obtained by the method of the present invention are that AC3+oo is sufficiently large as seen in Experiment 1fx23-24; Even if fibers obtained by methods other than the invention were heat-treated after drawing, AC3
+oo does not satisfy the value specified in the present invention.

(Effect of the invention) The above implementation f! As is clear from ilJ, the present invention is capable of reducing the low take-up speed in the spinning-winding system during melt spinning of polyester, at which it was difficult to obtain oriented crystallized yarn with a large crystal size AC3+oo in the prior art. In the area, A
This made it possible to obtain a large oriented crystalline yarn of C3+oo.

Further, the polyester fiber of the present invention contains polyethylene and has an AC8+o polyester portion.

This is an oriented crystallized thread having a structure with extremely large diameter, which, as far as the inventors know, has not been previously known.

Such oriented crystallized polyester fibers are extremely useful because they have a unique microstructure, and their uses are not particularly limited, such as fibers for highly twisted textured textiles, high modulus low shrinkage yarns, etc. Its usefulness for applications is great.

Claims (1)

[Scope of Claims] 1. A fiber containing 0.5 to 30% by weight of polyethylene based on the polyester in a polyester having ethylene terephthalate as a main structural unit, the fiber having an apparent appearance of the (100) plane of the polyester portion Crystal size ACS_1
A polyester fiber characterized in that _0_0 is 35 Å or more. 2. The polyester fiber according to claim 1, wherein the polyester portion has an ACS_1_0_0 of 45 Å or more. 3.The content of polyethylene is 1~1 to polyester
25% by weight of the polyester fiber according to claim 1 or 2. 4. In polyester whose main structural unit is ethylene terephthalate, 0.5 to 30
% by weight of polyethylene is added, melt-spun, cooled, and then taken off by a take-off roller, the speed of the take-off roller (
A method for producing polyester fibers, characterized in that Vm/min) is within the range of formula (1) below. V≧7600-7262.1×IV^1^. ^4^7-
50×W・・・(1) (However, V is the take-up speed (m
/min), W represents the amount of polyethylene added to polyester (% by weight), and IV represents the intrinsic viscosity of the polyester portion of the fiber. ) 5. The amount of polyethylene added is 1 to 1% of polyester.
The method for producing polyester fibers according to claim 4, wherein the content is 25% by weight.