JPH04100916A - Polyphenylene sulfide fiber and its production - Google Patents

Abstract

PURPOSE:To obtain the subject high-strength and high-elastic modulus fiber by melting polyphenylene sulfide having a specific melt index by heating, then successively passing the melt through a filtering filter having pores and spinneret holes, providing spun yarn, keeping the yarn warm, subsequently cooling the yarn, applying an oiling agent thereto and hot drawing the oiled yarn. CONSTITUTION:Pellets of polyphenylene sulfide having 100-600 melt index are melted at 310-340 deg.C temperature, then successively passed through a filtering filter having pores with <=20mu diameter and spinneret holes having 0.1-0.5mm diameter to provide spun yarn, which is subsequently passed through a heat insulating cylinder at 150-350 deg.C atmospheric temperature through a distance of 5-30mm just under the spinneret and then cooled with warm air at <=100 deg.C. After applying an oiling agent thereto, undrawn yarn taken off with a take-off roll rotating at 300-1000m/min speed is hot drawn at 3.0-5.5 times draw ratio and 120-180 deg.C roll surface temperature within a hot drawing zone to afford the objective fiber having <=50 denier single filament size, >=3O0X10<-8> birefringence, 20-28Angstrom crystal size measured by wide angle X-ray scattering without any observed long-period structure according to small-angle X-ray scattering with >=165 deg.C main dispersion peak temperature of loss tangent.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to polyphenylene sulfide fibers and methods for producing the same. Industrial material applications, e.g. bag filters
To provide filament fibers having high strength and appropriate shrinkage characteristics suitable for scrim base fabrics, motor knotted cords, motor binder tapes, etc., and to provide a novel manufacturing method for efficiently manufacturing the fibers. It is.

[Prior Art] In recent years, polyphenylene sulfide has attracted attention as a high-performance engineering plastic due to its excellent heat resistance and chemical resistance, and its practical use is expanding.

Since fiberization of the polymer was disclosed in Japanese Patent Application Laid-Open No. 49-54617, advances in yarn spinning technology have led to the disclosure of techniques for improving fiber properties and manufacturing processes. For example, JP-A-57-143518, JP-A-61-615715, and JP-A-1-2391.
There are publications such as Publication No. 09.

[Problem to be solved by the invention] The above-mentioned Japanese Patent Application Laid-open No. 49-54617 is a basic patent related to fiberization of polyphenylene sulfide (hereinafter abbreviated as PPS), and describes the application of general fiberization technology. However, no new silk-spinning technology that takes advantage of the characteristics of PPS polymer has been disclosed. The physical properties of the obtained PPS fibers are also not excellent; for example, according to Example 2, the strength is only described as 2.75 g/d at most.

Furthermore, although JP-A-57-143518 discloses the technology related to PPS yarn spinning and discloses the conditions for the two-stage drawing method, the relationship with the fiber structure is not clarified.
In the specification, even in the case of the best mechanical properties, the strength is 5.
8 g/d and elongation of only 13%, and it cannot be said that the obtained PPS fiber has sufficient strength and elongation.

JP-A-61-215715 discloses that the shear rate is 200
Melt viscosity μ at sec-' (310°C) is 6000 to 2
Polyarylene thioether (polyphenylene sulfide), a relatively high viscosity polymer with a relatively high viscosity of 0,000 poise, is spun into yarn with a diameter of 1 to 50μ and a tensile strength of 40kg/mm' (
3,3g/d), tensile modulus ≧500kg/mm'(
41g/d), tensile strength (200°C) ≧20kg/m
A method for obtaining PPS fibers of m' (1,7 g/d) is disclosed.

In addition, the fiber is produced by direct spinning and drawing, and at that time,
It discloses a method of heat treatment at a high temperature of melting point -100°C or higher for 0.02 to 100 seconds.

However, according to the examples described in the publication, the strength is at most 70 kg/mm' (5°78 g
/ d), there is no description of elongation, and it cannot be said that sufficient strength and elongation are obtained. In addition, since the temperature for direct spinning and drawing is higher than the heat treatment temperature (melting point -100°C), polyphenylene sulfide fibers with low shrinkage rate can be obtained.

That is, conventionally known PPS fibers have not been able to have a high strength of 5.5 g/d or more, a high elongation of 20% or more, and appropriate shrinkage characteristics. Another problem has been that a fiber with extremely low fluff, which is optimal as a fiber for textiles such as bag filter scrim base fabrics that takes advantage of the heat resistance and chemical resistance of PPS fibers, has not been provided.

The purpose of the present invention is to efficiently produce fibers with high strength, high toughness, appropriate shrinkage characteristics, and extremely low fluff, suitable for textile applications, for example, 1 fiber per 100 square meters or less, preferably 0.1 fibers or less. The goal is to manufacture products.

[Means and effects for solving the problems] The present invention has the following features: (1) A polyphenylene sulfide fiber consisting of continuous filaments with a single filament fineness of 50 deniers or less,
A polyphenylene sulfide fiber characterized by simultaneously satisfying the following fiber structure parameters (a) to (d).

(a) Birefringence (Δn) is 300×10-” or more.

(b) Apparent crystal size D determined from wide-angle X-ray scattering,
2°. , is 20 Å to 28 people.

(c) No long-period structure due to small-angle X-ray scattering is observed.

(d) The tangent loss principal dispersion peak temperature (Tα) determined by dynamic viscoelasticity must be 1656C or higher.

(2) In the polyphenylene sulfide fiber described in item (1) above, the polyphenylene sulfide fiber has the following fiber physical properties (e) to (g).

(e) Strength should be 5.5 g/d or more.

(f) Elongation must be 20% or more.

(g) Boiling water shrinkage rate is 2.0 to 8.0%.

(3) In the method for producing polyphenylene sulfide fiber, the melt flow rate (MFR) is 100 to 600.
Using a polyphenylene sulfide polymer of The spun yarn is made into a spun yarn, and the atmospheric temperature of the spun yarn is 150 to 350 cm directly below the spindle in which the spinneret hole is bored.
After passing through a high-temperature atmosphere surrounded by a heat insulating cylinder or heating cylinder adjusted to have a temperature of After the application of A method for producing polyphenylene sulfide fibers, which comprises performing hot stretching at a magnification of 3.0 to 55 times and a maximum temperature of the atmosphere or roll surface during stretching of 120 to 180°C.

It is.

Polyphenylene sulfide fiber (hereinafter referred to as P) according to the present invention
(referred to as PS fiber) is a continuous filament with a single filament fineness of 50 denier or less.

When the single yarn fineness exceeds 50 denier, the PP according to the present invention
It is not possible to satisfy all of the fiber structure parameters and fiber physical properties that are characteristic of S fibers, and they cannot be obtained by the production method according to the present invention.

The PPS fiber of the present invention is highly oriented with a birefringence of 300X10-' or more, preferably 350X10-3 or more. If the birefringence is less than 300X10-3, is it a high-strength fiber with a birefringence of 5° or more than 5g/d? I can't get G.

The PPS fiber of the present invention has an apparent crystal size D Boo, determined from wide-angle X-ray scattering, of 20 to 28, preferably 22
It is characterized by its relatively small size, with ~26 people. Conventional PP
S fibers are 26 Å or more, usually 28-30. When manufactured using a two-step method that separates spinning and drawing, or when subjected to heat treatment at high temperatures and for a long time in the direct spinning/drawing method, the crystal size increases, and the relatively small crystal size of the fiber of the present invention is caused by direct spinning. The stretching method can achieve the thermal history specified by the method according to the invention.

Furthermore, the PPS fiber of the present invention is characterized in that no long-period structure measured by small-angle X-ray scattering is observed. Conventional PP
The S fiber has a long-period structure of 100 to 120 people.

PP with high orientation and high strength but no long-period structure
The S fiber is obtained by the direct spinning drawing method according to the present invention, which comprises specific conditions.

Next, the PPS fiber of the present invention has a unique dynamic viscoelastic behavior compared to conventional KPPS fibers, and has a high tangent loss principal dispersion peak temperature of 165°C or higher, preferably 170°C or higher. Conventional PPS fibers are below 165°C.

The fibers of the present invention show that the motion of the molecular chains in the amorphous portion is restricted up to higher temperatures, and this high temperature property makes the heat resistance, which is a characteristic of PPS fibers, even more remarkable.

The present invention P characterized by the above fiber structure parameters
The PS fiber has high strength and toughness, with a strength of 5.5 g/d or more and an elongation of 20% or more, preferably 5.8 g/d or more and 25% or more, respectively. Also, the boiling water shrinkage rate is 2.0.
~8. , 0%, preferably 30 to 6.0%, which is suitable for use as a PPS fiber. In particular, it has excellent strength and elongation properties that have not been available with conventional fibers.

P that expresses the above fiber structure parameters and fiber physical properties
PS fibers can be produced by the following new method.

The polyphenylene sulfide polymer used in the present invention is a substantially linear polymer having a melt flow rate (VFR) of 100 to 600, or a substantially linear polymer having a melt flow rate (VFR) of 100 to 600, or a substantially linear polymer having a melt flow rate (VFR) of 100 to 600;
A crosslinked polymer containing 0.1% by weight or less of B) may also be used.

Melt flow rate (MFR) is measured at a temperature of 316°C.
Polymer melt flow measured by ASTM D1238-82 method with a load of 5 kgf.

Commercially available polyphenylene sulfide polymers are 100-2
It is preferable to dry at 00°C for 2 hours or more, usually 4 to 48 hours. This is mainly because removal of low-boiling substances and/or appropriate crystallization improves the properties of the material being incorporated into the spinning machine.

The polyphenylene sulfide polymer of the present invention is preferably melted in an extruder-type spinning machine, passed through a filter having openings of 20μ or less, preferably 10μ or less, and then 0.1 to 0.5mm, preferably 0.5mm or less. 2~
It is spun into a spun yarn using a spinneret having pores of 0.3 mm.

Next, the spun yarn is passed through a high-temperature atmosphere surrounded by a heat insulating cylinder or a heating cylinder so that the atmospheric temperature within 5"30 cm directly below the spinneret is 150 to 350°C, and then heated to 100°C.
Cool with warm air below. Appropriate conditions for the high-temperature atmosphere provided directly below the spinneret are selected depending on the melt flow rate (MFR) of the polymer, the fineness of the yarn, the spinning speed, etc.

If spinning is performed without providing a high-temperature atmosphere directly under the spinneret, it is difficult to stably spin and draw particularly thick filaments. The yarn passed through the high-temperature atmosphere was cooled for 10 minutes.
Hot or cold air at a temperature of 0° C. or lower, preferably 80 to 20° C., is used.

Next, the cooled and solidified yarn is coated with an oil agent normally used for PPS fibers, and then taken off by a take-up roll rotating at a speed of 300 to 1000 m/min to become an undrawn yarn. When the spinning speed exceeds 1000 m/min, high strength and high toughness yarns having an elongation of 5.5 g/d or more and 20% or more cannot be obtained. If the speed is less than 300 m/min, the spinning efficiency is low and it is industrially disadvantageous.

The above-mentioned undrawn yarn is continuously hot drawn without being wound up once. Usually, multistage stretching of two or more stages is used. The stretching ratio is 3.0 to 5.5 times, preferably 3.5 to 5.0 times, depending on the spinning conditions. When using two-stage stretching, 1
The stretching of each step is 70% or more of the total stretching ratio, usually 75~
85%, and the rest is carried out in the second stage of stretching. The maximum stretching temperature is 120 to 180°C. If the temperature is lower than 120°C or higher than 180°C, polyphenylene sulfide fibers having the structural parameters and fiber physical properties of the fibers of the present invention cannot be obtained.

Furthermore, it is not possible to obtain fibers with extremely low fuzz that are suitable for textile applications, which is the object of the present invention.

The fibers that have been hot-stretched are subjected to a relaxing heat treatment between relaxation rolls and then wound up. The relaxation rate is 0 to 10%, preferably 2 to 6%.

As described above, by the method according to the present invention, the PPS fiber of the present invention has specific fiber structure parameters, high strength, high toughness, moderate shrinkage characteristics, is suitable for textile applications, has extremely low fuzz, for example, It is possible to efficiently produce fibers with a fiber size of 0.1 or less, preferably 0.1 or less.

Next, examples will be explained, or the main text of the present invention specification,
The definitions and measurement methods of the fiber properties described in the examples are as follows.

(a) Birefringence (Δn): Measured using a POH type polarizing microscope manufactured by Nippon Kogaku Kogyo Co., Ltd., using the usual Berek convensator method using sodium=D line as a light source.

(b) Apparent crystal size (D (200)): Measured by the counter method using a small-angle X-ray scattering device model 4036A2 manufactured by Rigaku Denki Co., Ltd. with CuKα (using a Ni filter) as a radiation source. The output was 35kV and 15mmA, and a 1mmφ pinhole collimator was used for the thrift. Shooting conditions: camera radius 40mm, film Kodak
DEF-5, exposure time was 30 minutes.

The apparent crystal size was calculated from the half width of the peak of the surface index (200) using the following 5cherrer formula.

L (hk l)=λ/βoCO8θB However, L(
hkl) is the average size of the microcrystals in the vertical direction, K is 1
01λ is the wavelength of X-rays, βo = (β, -β 2) l/2
) β6 is the apparent half-width (measured value), β1-06, β6
is the Bragg angle.

(C) Long period (J): Measurement was carried out by photography using a small-angle X-ray device RU-200 manufactured by Rigaku Denki Co., Ltd. using Cukα (using a Ni filter) as a radiation source. The output was 50 KV and 200 mmA, and a pinhole collimator with a 0°3 mm diameter slit was used.

Shooting conditions: camera radius 400mm, film Kod.
ak DEF-5, exposure time was 90 minutes.

It was calculated from the distance r on the small-angle X-ray photograph using Bragg's formula (% formula %) (where R: camera radius, λ: wavelength of X-ray, J: long period).

(d) Tangent loss peak temperature (Tα): “VibronDDV-n” manufactured by Orientic Co., Ltd.
The measurement was carried out in an air bath at a frequency of 110 Hz and a heating rate of 3° C./min.

(e) Strength (T/D), elongation (E): The strength and initial tensile resistance were in accordance with the definition and measurement method of JIS LIO17. The specific conditions for the tensile test to obtain the SS curve are as follows.

Take the sample into a rough shape, leave it in a temperature and humidity controlled room at 20℃ and 65% RH for more than 24 hours, and then
-4L" type tensile testing machine (manufactured by Orientic Co., Ltd.), the test length was 25 cm, and the tensile speed was 30 cm/min.

(f) Boiling water shrinkage rate (JS): After taking a sample into a general shape and leaving it in a temperature and humidity controlled room at 200C and 60% RI-1 for more than 24 hours, 0.1g/d of the sample
Length measured by applying a load equivalent to . After processing the sample in a boiling water bath for 30 minutes in a tension-free state, it was taken out from the bath and left in the above temperature and humidity control room for 4 hours, and the length was measured by applying the same load again, from the following formula. Calculated by.

, as-[(r-o-L+)/Lo)X100 (%)
[Example] Example-1 A polyphenylene sulfide polymer with a melt flow rate of 300 was melted at 330°C in an extruder type spinning machine, filtered in a spinning bag with a metal filter having 5μ pores, and then 0.25mmφ. The yarn was spun through a spinneret having 100 pores to form a spun yarn, and the discharge rate was varied according to the spinning conditions so that the wound yarn was approximately 400 deniers.

The spun yarn has an atmospheric temperature of 320 cm for the 15 cm directly below the spinneret.
After passing through a heating cylinder maintained at ℃, it is cooled with hot air at 60℃, a water-based emulsion oil is applied to the cooled and solidified yarn, and then it is taken up by an unheated take-up roll that rotates at a predetermined speed. The yarn was stretched by 5% between a feed roll heated to 60°C continuously without being wound up, and then stretched by 5% between the feed roll and the feed roll for 10 minutes.
A first stage of stretching was performed between the first stage of stretching rolls at 0°C, and then a second stage of stretching was performed between the first stage of stretching rolls and a second stage of stretching rolls heated to a predetermined temperature. Next, after relaxing between the two-stage stretching roll and an unheated relaxing roll,
The fibers of the present invention were obtained by winding with a winder.

The take-up roll and each stretching roll were of the Nelson type, and the entangling treatment was performed using compressed air at 4 kg/cm2G during the first stage of stretching.

The production conditions are shown in Table 1 and the obtained P
The fiber properties of the PS fiber (Example-1) are as shown in Table 2 (Example).

Examples 2 and 3 and Comparative Examples 1 to 8 PPS fibers were obtained by changing part of the spinning conditions of Example 1. Table 2 shows the various spinning conditions and the properties of the obtained PPS fibers.

(Left below) [Effects of the invention] The PPS fiber according to the present invention has a high strength of 5.5 g/d or more, a high elongation of 25% or more, and a shrinkage rate within a specific range. P with extremely low fuzz, for example, less than 1 fuzz per 100 m, which is particularly suitable for textile applications.
A method for producing PS fibers is provided.

The PPS fiber according to the present invention has the above-mentioned excellent properties and is particularly suitable for bag filter scrim base fabrics, motor binding strings, motor binding tapes, and the like.

Furthermore, the method for producing PPS fibers according to the present invention has excellent quality and stability in the spinning process, and can efficiently produce PPS fibers having the excellent properties described in the present invention.

Claims (3)

[Claims] (1) A polyphenylene sulfide fiber consisting of continuous filaments with a single filament fineness of 50 denier or less,
A polyphenylene sulfide fiber characterized by simultaneously satisfying the following fiber structure parameters (a) to (d). (a) Birefringence (Δn) is 300×10^-^3 or more. (b) Apparent crystal size D_ determined from wide-angle X-ray scattering
(_2_0_0_) is 20 Å to 28 Å. (c) No long-period structure due to small-angle X-ray scattering is observed. (d) The tangent loss principal dispersion peak temperature (Tα) determined by dynamic viscoelasticity is 165°C or higher. (2) The polyphenylene sulfide fiber according to claim (1), which has the following fiber physical properties (e) to (g). (e) Strength should be 5.5 g/d or more. (f) Elongation must be 20% or more. (g) Boiling water shrinkage rate is 2.0 to 8.0%. (3) In the method for producing polyphenylene sulfide fiber, the melt flow rate (MFR) is 100 to 600.
Using a polyphenylene sulfide polymer of The spun yarn is made into a spun yarn, and the atmospheric temperature of the spun yarn is 150 to 350 cm directly below the spindle in which the spinneret hole is bored.
After passing through a high-temperature atmosphere surrounded by a heat insulating cylinder or heating cylinder adjusted to have a temperature of After the application, the undrawn yarn is taken off by a take-off roll rotating at a speed of 300 to 1000 m/min, and the undrawn yarn taken off by the take-off roll is continuously transferred to a hot drawing area without being wound once, and the stretching ratio is A method for producing polyphenylene sulfide fibers, which is characterized in that hot stretching is carried out at a stretching ratio of 3.0 to 5.5 times and the maximum temperature of the atmosphere or roll surface during stretching is 120 to 180°C.