JPS60259616A - Polyester fiber - Google Patents

Abstract

PURPOSE:To provide the titled fiber composed mainly of ethylene terephthalate, having specific values of elongation, birefringence, peak temperature and peak level of thermal stress and boiling water shrinkage, and excellent age stability, and suitable for the drawing false twisting process. CONSTITUTION:The objective fiber is a polyester fiber consisting of a polyester containing ethylene terephthalate as main recurring unit, and having an elongation of 40-60% and birefringence (DELTAn) of 0.09-0.13. The peak temperature and the peak level of the thermal stress of the fiber are 75-100 deg.C and 0.3-0.5g/de, respectively, and the boiling water shrinkage is >=40%. The above polyester fiber is preferably a fiber for drawing false twisting process.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to polyester fibers, and particularly to polyester fibers suitable for drawing and false twisting.

(Prior Art) As polyester fibers to be subjected to the stretching and false twisting process, partially oriented yarns spun at a speed of 3000 to 4000 yards/min, so-called POY (Par
tial Iy Oriented Yarn) has been widely used recently. However, such polyester fibers do not necessarily have sufficient static stability and cannot withstand long-term storage or transportation. There is a drawback that the appearance and texture of the bulky processed yarn is inferior.

In particular, during high-speed drawing and false twisting, a large drawing deformation occurs at high speeds, which causes the filament to break easily and fuzz and yarn breakage are likely to occur.1, such POY
Polyester fibers that have recently been spun at high speed at a foaming speed of 4,000 to 6,000 m/min, or spun yarn, are instantaneously heat-treated with a heated gas of 150°C or higher, and then spun at a speed of 2,000 to 4,500 m/min. It has been proposed to subject the bowed polyester fibers to stretching and false twisting (for example, Japanese Patent Publication No. 5B-36086, Japanese Patent Publication No. 58-1986).
No. 18446, Japanese Patent Publication No. 58-17294, Japanese Patent Publication No. 1983
-169513). Since such polyethyl fibers have a high degree of orientation and crystallinity, they have improved stability over time and have been shown to have improvement effects such as a reduction in the cross-sectional aspect ratio during drawing and false twisting. In the false twisting process, so-called crystal stretching, which involves destruction and rearrangement of crystals during stretching, occurs, which has the disadvantage that fuzz tends to occur.

Furthermore, there was also a drawback that the resulting drawn and false twisted yarn had poor unwinding and weaving properties during the transfer process.

In addition, in recent years, polyester with no shrinkage difference has been developed.
Research on latent bulky multifilaments mixed with am is also being actively conducted.

The above-mentioned POY is often used as the high shrinkage polyester fiber used in this case, but as mentioned above, it is difficult to handle due to its poor stability over time. If the spun yarn is heat-treated and then drawn at high speed, the stability over time is good, but the difference in shrinkage between the filaments of the resulting latent bulky multifilament cannot be sufficiently imparted, making it unsatisfactory. It was not possible to exhibit sufficient bulk.

(Object of the Invention) The object of the present invention is to provide a polyester fiber that can eliminate the above-mentioned drawbacks, and in particular satisfies the following required properties (11 to (4)σ) at the same time. Our goal is to provide suitable polyester fibers.

(1) It has stability over time suitable for long-term storage.

(2ゝ f+ 745 during stretch false twisting, ly)
F) Cross-sectional deformation (Small shape.) (3) Less fuzz is generated during stretching and pre-processing.

(4) The resulting false twisted yarn has good unwinding and weaving properties.

(Structure) In order to achieve this objective, the present inventors first studied the allowable levels of each of the required characteristics (1) to (4). Regarding cross-sectional deformation, the cross-sectional flatness (described below) must be 1.5 or less, the fuzz must be 10 pieces/lo'm or less, and there must be no defects in unwinding and weaving properties. I learned.

The present inventors have arrived at the present invention as a result of extensive studies on polyester fibers that can simultaneously achieve such acceptable levels.

That is, the present invention is made of polyester whose main repeating unit is ethylene terephthalate, and whose elongation is 40.
-60%, multilayer fold (Δn) is 0.09-0.13, and the peak temperature and peak value of thermal stress of the fiber are 75-100°C and 0.3-100°C, respectively. 0
．． 59/c3e and a water production shrinkage rate of 40 factors or more.

Before describing the present invention in detail, a method for measuring each characteristic value used in the present invention will be described.

Elongation A tensile test was performed using a Tensilon tensile testing machine under the condition of a sample length of 20 bacteria, and the elongation wheel at the time of cutting is shown.

Fosui Shrinkage Rate When a sample is heat-treated in 100°C water for 30 minutes in an unrestrained state, the amount of shrinkage is expressed as a) percentage of the sample length before treatment. Initial stress cateny k/30 F' + using machine KE-1
Measurements were carried out under conditions of a sample length of 10 m and a heating rate of 2.5°C/sec.

Stability over time The sample package was stored in a temperature-controlled room with a temperature of 35℃ and a humidity of 55℃, and after a predetermined number of days, it was taken out and subjected to stretching and false twisting according to the procedure described below, and the resulting processed yarn was stockinette knitted and dyed. went. The dyeing becomes darker as the number of days passes, but standard yarn (25℃, 6s after winding under various standard conditions)
The dyeing difference between the yarn and the stretched and false-twisted processed yarn after being left in a +RH room for one day was visually judged, and expressed as the number of days in which the dyeing difference reached the allowable limit.

The cross-sectional flatness ratio and the cross-sectional flatness height are as follows: b is the inner diameter (diagonal line) of the filament cross section of the drawn false-twisted yarn that is ik ton longer, and a is the longest diameter perpendicular to the longest diameter.
It is defined as b/a when The closer the flat book is to 1, the closer it is to a perfect circle.

X11 Hair A hair tester manufactured by Engineering (HAIRINES) is installed downstream of the twisting unit during the drawing process
The number of fluffs generated was measured for 30 minutes using a SC0UNTERMODEL DT-104) and converted into the number of fluffs/10'm.

The invention will now be described in detail.

The term "polyester" used in the present invention generally refers to monomers of polyethylene terephthalate, polyester copolymers containing 90 or more moles of ethylene terephthalate units, and blends containing these polyesters as main components. The polyester may contain small amounts of additives (for example, matting agents, pigments, dyes, stabilizers, M fuel 1 surface modifiers, etc.) as necessary. Among these polyesters, the intrinsic viscosity K (measured with O-chlorophenol solution at 35°C) is 065 or more, especially 0.55 to 0.95.
Preferably.

In the present invention, first, it is necessary that the elongation (at break) of the polyester fiber is between 40 and 60 1'. If the elongation exceeds a factor of 6.0, the stretching ratio during draw false twisting becomes high, resulting in flattening of the cross section of the filament during draw false twisting. In addition, if the elongation is less than 40%, the fibers will not have enough elasticity, so during high-speed drawing and false twisting, the yarn shaking and ballooning that occur cannot be absorbed by itself, resulting in crimp spots and induces fluff. Next, birefringence (
Δn) is required to be 0.09 to 0.13. Δ
When n is less than 0.09, stability over time is insufficient, and during long-term transportation or storage, the orientation of the fibers gradually changes to a non-oriented direction, resulting in a deep dyeing phenomenon. Further, when Δn exceeds 0.13, a phenomenon occurs in which the residual torque of the drawn and false twisted yarn becomes high, and the unwinding property and weaving property in the edge process deteriorate.

Furthermore, the peak temperature (Tmax) of thermal stress is 75-100
℃ and the peak value (TSTmax) is 0.3 to 0.5
．． ! ? /de is required. Tmax is 100
℃ and TSTmax is 0.5.9/
If it exceeds de, disadvantages such as the generation of fuzz and a decrease in crimp rate occur during the stretching and false twisting process. This is a high Tmax
This is thought to be due to the fact that in the case of polyester fibers with a high value, the flexibility of the fibers against heat decreases, which deteriorates the ability to follow deformation during stretching and false twisting.

On the other hand, when Tmax is less than 75°C and N- is 0.3
．． If 9/de does not drop, the yarn is likely to melt and break in the heater during drawing and false twisting.

In the polyester fiber of the present invention, even if the elongation, birefringence "a (△n), thermal stress σ) peak temperature and peak value described above are within the range specified by the present invention, the water production shrinkage rate is 40
% or more, the object of the present invention cannot be achieved. The water shrinkage wheel referred to here is used as a characteristic to express the crystallinity of fibers, and is based on Shimizu et al.'s Journal of Fiber Science and Technology, 34 T-93 (1).
978), the water production shrinkage wheel decreases with increasing crystallinity.

In the case of 141J ester fiber with a water production shrinkage ratio of less than 40 factors, crystal stretching occurs during stretching and false twisting, resulting in crystal destruction and generation of high stretching tension, resulting in frequent filament breakage, that is, fluffing. do. . In this way, the elongation is 4
Coefficient 0 to 60, birefringence (△n) of the entire fiber is 0.09 to 0
．． 13. Water production shrinkage is 40 inches or more, the peak temperature of thermal stress is 75-100℃, and the peak value is 0.3-0.5
．． Only polyester fibers with 9/(ie) can have stability over time, filament side cross-sectional deformability, fuzz resistance, and good unwinding and weaving properties during drawing and cursing.

Traditional volume. 7 terres, i.e. 4000-6000m
/min high speed spinning, or spun thread length 150°
2000~4500 after heat treatment with heated gas of C or higher
When the fibers are drawn at a speed of m/' min, the fiber orientation (birefringence height) increases, and at the same time, the crystallinity also increases rapidly, and the water shrinkage decreases rapidly. For this reason) ゛ □, say, 4; ') y-7 /1. #mnye1.
, □ process, thermal stress and water production shrinkage plan can simultaneously satisfy the range specified in the present invention, changes over time, filament cross-sectional deformation and fuzz during temporary press processing, as well as unwinding property and weavability, etc. It is possible to exceed the tolerance level at the same time t, r
, is ino.

The polyester fiber of the present invention as described in J. So. 10 is produced by a conventional melt spinning method. To give an example, Bo II ester is melted and discharged from a nozzle, and the atmosphere immediately after being discharged from the nozzle is maintained at least 20 times over a period of 20 minutes.
The yarn is kept at a high temperature above 0°C, immediately after which it is quenched by blowing cold air at 10 to 20°C, and then heat treated by running through a heat treatment zone at 70 to 110°C.
It is industrially advantageous to produce it by drawing at a speed of 500 to 6000 m/min.

At this time, the temperature and take-off speed of the low-temperature heat treatment zone are important, and the polyester fiber of the present invention can only be obtained if the temperature and take-off speed are within the above ranges. It goes without saying that other methods may be used as long as the properties of the finally obtained polyester fibers satisfy the range specified in the present invention.

(Function) Conventionally, after heat treatment of spun yarn at 150°C or higher, 2 (l
The polyester fiber drawn at OO-4500 m/min has a very high degree of orientation and crystallinity, so it is satisfactory in terms of stability over time and cross-sectional deformation of the filament during the drawing and tacking process. However, crystallization and stretching occur during the stretching and false twisting process, and fuzz occurs frequently because the deformation followability to heat is poor.

Moreover, the resulting processed yarn has a high residual torque, resulting in poor unwinding and weaving properties.

As a result of this, the polyester fiber of the present invention has appropriate orientation, crystallinity, and deformation followability against heat, and as a result, the stability over time is 150 days. , during the draw-twisting process (σ), it is possible to adopt a draw-folding plan in which the ficimen 1 cross-sectional flatness of the obtained processed yarn can be made 1.5 or less. Even when applied, crystallization and stretching do not occur, and the polyester fiber of the present invention has good deformation followability against heat, so the fluff of the resulting processed yarn is 10 pieces/10'm.
Furthermore, since the residual torque of the processed yarn obtained is also low, the unwinding and weaving properties of the processed yarn are also good.

In this way, the polyester fiber of the present invention has the required properties (1
In a potentially bulky multifilament that simultaneously satisfies the requirements of ) to (4) and uses such a polyester fiber as a high shrinkage filament, the high shrinkage filament has good stability over time and the difference in shrinkage between the constituent filaments is sufficiently increased. Therefore, both the ease of handling and the bulkiness of the multifilament are satisfactory.

(Effects of the Invention) According to the polyester #l# of the present invention, it is possible to easily manage the raw yarn and have good processability, especially in the drawing and tacking process, and the appearance and appearance of the processed yarn obtained Both the texture and the process passability in the weaving and knitting process can be improved.

(Example) Next, the present invention will be further described in detail with reference to Examples. Intrinsic viscosity 0.64
Chips of n-polyethylene terephthalate (melting point 261°C, glass transition A 68°C) were melted and discharged at 300°C from a spinneret with a hole diameter of 0.3 m and a number of holes of 36.
The core filament is heated by a cylindrical heating stove 11-no, and then cooling air is blown from the side on the spun yarn at a distance of 1.3 m below the spinneret to cool the nuclear filament. The material was passed through a heating zone of .degree. Om, and then a finishing agent was applied to an oiling roller, taken up by a pair of godet rollers 1-1, and wound up in a warder.

The physical properties of the fibers obtained under each condition are shown in Table 1.

Next, the above-mentioned undrawn yarn is subjected to sflag processing using a friction disk processing method: #! Supplied to a 5 ps-s type drawing false twisting machine, the ratio D/Y of disk surface speed and yarn speed was 1.7.
08, 75 denier, 36 A processed filament yarn was obtained. The properties of the processed yarn obtained at this time are also shown in Table 1. 1st
In the table, Tests 1 to 12 are those with a take-up speed of 5000 m/min and other manufacturing issues changed, and experimental AI
3 to 14 change the collection speed, and experimental waste 15
~18 The take-up speed was changed using the usual method without heating after air-cooling the yarn (26 cases).

The embodiments according to the present invention are real trunk seats 1, 2, 7.8, and the seats are comparative examples.

As is clear from Table 1, only polyester fibers within the range specified by the present invention have the required properties (11 to (4)).
F [is within the capacity level.

i

Claims (1)

[Claims]
The polyester I fiber has a birefringence value (△n) of 0.09 to 0.13, and the peak temperature and peak value of thermal stress of the fiber are 75-100°C and 0.3 to 0. .5
9/de and a boiling water shrinkage ratio of 40 or more. (2) The polyester fiber according to claim (1), wherein the #polyester #fiber is a polyester fiber for drawn false twist processing.