JP2011106060A - Polyarylene sulfide fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide polyarylene sulfide fiber which is excellent in dimensional stability, chemical resistance and heat resistance. <P>SOLUTION: To solve the problem, there is provided a fiber made of a blend polymer of 92-99.9 wt.% of polyarylene sulfide and 0.1-8 wt.% of polyalkylene terephthalate. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a polyarylene sulfide fiber, and more particularly to a polyarylene sulfide fiber having excellent dimensional stability and excellent chemical resistance and heat resistance.

  Polyarylene sulfide (PAS) is attracting attention as an electrical / electronic equipment member and an automotive equipment member by taking advantage of its excellent heat resistance, chemical resistance and flame retardancy. Further, it can be molded into various molded parts, films, sheets, fibers, etc. by injection molding, extrusion molding, etc., and is widely used in fields requiring heat resistance, chemical resistance, and flame resistance.

  The fiber manufacturing technology of polyarylene sulfide is conventionally known (patent documents 1 to 3). The fibers thus obtained have high heat resistance, and in particular, polyphenylene sulfide fibers are used as raw materials for fiber products used under harsh conditions such as industrial filters and protective clothing.

  In recent years, the use conditions of polyphenylene sulfide fibers have become more severe, and heat resistance, chemical resistance, and dimensional stability under these severe conditions are required.

  Patent Document 4 proposes that fiber strength is improved by thoroughly removing low molecular weight substances contained in polyphenylene sulfide. However, in this method, it is necessary to repeat washing of PPS many times in order to remove low molecular weight substances, and there is a problem that the cost becomes high commercially.

  On the other hand, it has been conventionally practiced to modify PPS by kneading another polymer in PPS. Patent Document 5 proposes a resin composition containing PPS copolymerized PET. Although this method certainly improved the adhesion to the epoxy, the dimensional stability in the fiber form was low. Patent Document 6 proposes an alloy resin composition of PPS and polyethylene terephthalate (PET). According to this method, the dimensional stability of the PPS alloy fiber is equivalent to that of PPS. However, it has been found that chemical resistance and heat resistance are reduced due to the high concentration of PET.

  Thus, in the prior art, fibers that satisfy heat resistance, chemical resistance, and dimensional stability at high temperatures have not been obtained.

Japanese Patent Publication No.52-3609 JP-A-57-143518 JP 58-31112 A Japanese Patent Laid-Open No. 4-100915 JP-A-6-166816 Japanese Patent Laid-Open No. 2004-231908

  An object of the present invention is to provide a polyarylene sulfide fiber excellent in dimensional stability and excellent in chemical resistance and heat resistance.

  The object described above is achieved by a fiber comprising a blend polymer of 92 to 99.9% by weight of polyarylene sulfide and 0.1 to 8% by weight of polyalkylene terephthalate.

  ADVANTAGE OF THE INVENTION According to this invention, the polyarylene sulfide fiber excellent in the thermal dimensional stability suitable for an industrial material use, and excellent in chemical resistance and heat resistance can be provided.

  The present invention will be described in detail.

  The present invention is a fiber comprising a blend polymer of 92 to 99.9% by weight of polyarylene sulfide and 0.1 to 8% by weight of polyalkylene terephthalate.

  The present invention is characterized in that the content of polyalkylene terephthalate (PAT) is 0.1 to 8% by weight. By making the addition amount of polyalkylene terephthalate within this range, the thermal dimensional stability, chemical resistance and heat resistance are improved.

  Various methods for improving the thermal dimensional stability of the fiber are conceivable. However, increasing the crystallinity of the fiber improves the thermal dimensional stability of the fiber. The inventors have found that when polyarylene sulfide and polyalkylene terephthalate are blended at a certain ratio, the crystallization speed of polyarylene sulfide is improved. The cause of this is not clear, but it is believed that polyalkylene terephthalate is compatible with polyarylene sulfide and the mobility of the polyarylene sulfide molecular chain is improved, so that it becomes easier to form a crystal form and the crystallization speed is improved.

  That is, when the amount of polyalkylene terephthalate added is reduced, the crystallization rate is remarkably reduced, and when it is less than 0.1% by weight, thermal dimensional stability cannot be obtained. On the other hand, when the addition amount of polyalkylene terephthalate exceeds 8% by weight, the polyalkylene terephthalate becomes compatible with the polyarylene sulfide under special conditions, but in general, the polyalkylene terephthalate has a dispersed phase in the polyarylene sulfide. Forming and increasing its size. In the presence of an alkali or acid that easily decomposes polyalkylene terephthalate, polyalkylene terephthalate decomposes, and defects such as voids are generated in the fiber, resulting in a decrease in fiber strength. At high temperatures, the orientation of the polyalkylene terephthalate is disturbed and the fiber strength is greatly reduced.

  In addition, when polyarylene sulfide and polyalkylene terephthalate are compatibilized under special conditions, the mobility of polyarylene sulfide is improved, but the polyalkylene terephthalate inhibits the crystalline form of polyarylene sulfide, resulting in decreased crystallinity and thermal deterioration. Dimensional stability decreases.

  By optimizing the amounts of polyarylene sulfide and polyalkylene terephthalate as in the present invention, both thermal dimensional stability, heat resistance and chemical resistance can be achieved. Surprisingly, it has been found that the chemical resistance and heat resistance can be improved as compared with the polyarylene sulfide alone by making it within the scope of the present invention. Although the cause of this is not clear, it is believed that the chemical resistance and heat resistance are improved because the structure of the polyarylene sulfide fiber is dense. Thus, since the fiber of the present invention has improved chemical resistance and heat resistance compared to conventional polyarylene sulfides, it can be applied to special filter applications used under severe conditions.

  The content of polyalkylene terephthalate is preferably 1.5 to 8% by weight, and 2 to 5% by weight.

  Examples of the polyalkylene terephthalate of the present invention include polyalkylene terephthalate, copolyester of alkylene terephthalate, and a mixture of polyalkylene terephthalate.

  Examples of the polyalkylene terephthalate include polymers obtained using a diol component and a terephthalic acid component. Examples of the diol component include ethylene glycol, 1,4-butanediol, propylene glycol, trimethylene glycol, and tetramethylene glycol. , Hexamethylene glycol, neopentyl glycol, diethylene glycol, polyethylene glycol, cyclohexanedimethanol, 2,2-bis (2'-hydroxyethoxyphenyl) propane, and the like and derivatives thereof having ester-forming ability. Among them, 1,4-butanediol or its ester-forming derivative and polybutylene terephthalate, trimethylene glycol or its ester-forming ability obtained by polycondensation of terephthalic acid or its ester-forming derivative Polytrimethylene terephthalate obtained by polycondensation of the derivative with terephthalic acid or its ester-forming derivative, ethylene glycol or an ester-forming derivative thereof, and terephthalic acid or its ester-forming ability Polyethylene terephthalate obtained by polycondensation with a derivative is preferably used.

  In particular, when polyethylene terephthalate having an ethylene terephthalate unit of 90 mol% or more is used, the thermal dimensional stability of the fiber tends to be improved, which is more preferable.

  The polyarylene sulfide content of the present invention is 92 to 99.9% by weight. When the polyarylene sulfide content falls within this range, the thermal dimensional stability, chemical resistance, and heat resistance are improved.

  Polyarylene sulfide is a resin having high chemical resistance and heat resistance, and the chemical resistance and heat resistance can be obtained by arranging polyarylene sulfide on the surface of the fiber. Therefore, if the polyarylene sulfide is less than 92% by weight, the chemical resistance and heat resistance are lowered, and cannot be used in applications requiring chemical resistance and heat resistance. The polyarylene sulfide content is preferably 95% by weight or more.

  The polyarylene sulfide of the present invention is a homopolymer or copolymer having a repeating unit of the formula-(Ar-S)-as a main constituent unit. Examples of Ar include units represented by the following formulas (A) to (K), among which the units represented by formula (A) are particularly preferable.

  (In the formula, R1 and R2 are substituents selected from hydrogen, alkyl groups, alkoxy groups and halogen groups, and R1 and R2 may be the same or different.) As long as it is a structural unit, it can contain a small amount of branching units or crosslinking units represented by the following formulas (L) to (N). The copolymerization amount of these branch units or cross-linking units is preferably in the range of 0 to 5 mol%, more preferably in the range of 1 mol% or less, relative to the-(Ar-S) -unit.

  Further, the polyarylene sulfide resin in the present invention may be a random copolymer, a block copolymer and a mixture thereof containing the following repeating units.

  Typical examples of these PAS resins include polyphenylene sulfide, polyphenylene sulfide sulfone, polyphenylene sulfide ketone, random copolymers, block copolymers, and mixtures thereof. Particularly preferred polyarylene sulfide resins include p-phenylene units as the main structural unit of the polymer.

Are PPS, polyphenylene sulfide sulfone and polyphenylene sulfide ketone, and PPS is particularly preferable.

  The blend polymer of the present invention means a polymer composition in which polyarylene sulfide and polyalkylene terephthalate are kneaded (blended) at an arbitrary stage before melt spinning is completed by various methods as described below.

  In the present invention, the blend polymer can be blended with a polymer other than polyarylene sulfide and polyalkylene terephthalate as long as the effects of the present invention are not hindered.

  The fiber of the present invention is melted at 320 ° C. for 5 minutes, quenched with liquid nitrogen, and then has a crystallization temperature (Tc) of 90 to 130 ° C. measured at a heating rate of 16 ° C./min by differential scanning calorimetry (DSC) measurement. It is preferable that

  By setting the crystallization temperature within this range, the thermal dimensional stability of the fiber tends to be improved. More preferably, it is 100-125 degreeC.

  The fiber of the present invention has a half width (D) of a crystallization temperature peak measured at a temperature increase rate of 16 ° C./min by differential scanning calorimetry (DSC) measurement after being melted at 320 ° C. for 5 minutes and rapidly cooled with liquid nitrogen. It is preferable that it is 5 degrees C or less. When D is 5 ° C. or less, the thermal dimensional stability of the fiber tends to be improved, and the internal structure (such as crystallinity) of the fiber is made uniform, so that the strength is improved. More preferably, it is 4.5 degrees C or less.

  The form of the fiber of the present invention is preferably a multifilament, a short fiber, or a monofilament. The effect of this invention can fully be exhibited by setting it as these forms.

  When a multifilament is used as the form of the present invention, the strength is 2.0 cN / dtex or more from a practical viewpoint, more preferably 2.5 cN / dtex or more, and still more preferably 3.0 cN / dtex. On the other hand, the upper limit of the strength is 8.0 cN / dtex or less from the viewpoint that it can be produced industrially stably.

  In addition, the elongation of the multifilament is appropriately selected depending on the application, but is generally in the range of 20 to 80%. If the application requires high strength and dimensional stability, 20 to 50% is more preferable. Is 20-40%.

  Furthermore, the yarn unevenness U%, which is an index of quality in the longitudinal direction of the yarn, is preferably 0.1 to 2.0%. If the dispersibility of polyarylene sulfide and polyalkylene terephthalate is poor, viscosity spots are likely to occur in the spinner pack, and a ballistic effect is likely to occur.Furthermore, fineness spots will occur between the mouthpiece holes and in the length direction. It can be made into a multifilament that is good and free of yarn spots. The yarn unevenness U% is more preferably 0.1 to 1.5%, and further preferably 0.1 to 1.0%.

  The single filament fineness of the multifilament may be appropriately determined depending on the application, and is usually 0.1 to 10000 dtex. The total fineness of the multifilament is preferably 5 to 50000 dtex. Furthermore, the cross-sectional shape can be freely selected for a round cross-section, a hollow cross-section, a flat cross-section, a multi-leaf cross-section such as a trilobal cross-section, a W cross-section, an X cross-section, and other irregular cross-sections.

  When short fibers are used as the form of the present invention, the fiber length is preferably 3 to 200 mm from a practical viewpoint.

  Further, the fiber strength of short fibers is preferably 2.0 cN / dtex or more because it is practical. More preferably, it is 2.5 cN / dtex or more, More preferably, it is 3.0 cN / dtex or more. On the other hand, the upper limit of the strength is 8.0 cN / dtex or less from the viewpoint that it can be produced industrially stably.

  In addition, the elongation of the short fiber is appropriately selected depending on the use, but is generally in the range of 20 to 80%. If the use requires high strength and dimensional stability, 20 to 50% is more preferable. Is 20-40%.

  Furthermore, in order to obtain sufficient fiber entanglement property and yarn and sliver convergence, the degree of crimp of the short fibers in the present invention is preferably 3 to 35%, more preferably 10 to 23%, and more preferably 13 to 20%. Further preferred.

  The single fiber fineness of the short fiber may be appropriately determined depending on the application, and is usually 0.1 to 10000 dtex. In addition, the cross-sectional shape can be freely selected for a round cross-section, a hollow cross-section, a flat cross-section, a multi-leaf cross-section such as a trilobal cross-section, a W cross-section, an X cross-section, and other irregular cross-sections.

  When a monofilament is used as the form of the present invention, it is preferable to use a monofilament having a diameter of 0.05 to 4.00 mm from a practical viewpoint.

  The strength of the monofilament is preferably 2.0 cN / dtex or more because it is practical. More preferably, it is 2.5 cN / dtex or more, More preferably, it is 3.0 cN / dtex or more. On the other hand, the upper limit of the strength is 8.0 cN / dtex or less from the viewpoint that it can be produced industrially stably.

  Further, it is desirable that the monofilament has a knot strength of 1.5 to 4.5 cN / dtex and a hook strength of 2.0 to 10.0 cN / dtex. If the knot strength and the hook strength are less than the lower limit of the above strength range, they tend to be insufficient for industrial use, and if the upper limit of the strength range is exceeded, the bending durability tends to be remarkably lowered.

  If the polyarylene sulfide fiber of the present invention has a shrinkage ratio of 0 to 10% after heat treatment at 180 ° C. for 24 hours, the thermal dimensional stability of the fiber and the fiber product is preferable. More preferably, it is 1 to 8%.

  Further, the polyarylene sulfide fiber of the present invention preferably has a strength retention of 80 to 100% after heat treatment at 180 ° C. for 24 hours.

  It is generally known that the shrinkage rate and strength retention rate can be easily changed by optimizing the fiber production conditions. However, these characteristics can be easily obtained by using the fiber of the present invention. For example, the strength retention of a general-purpose polyphenylene sulfide fiber is 10% shrinkage and 90% strength retention as shown in Reference Example 1 in the Examples. As shown in Example 1, a very high strength retention rate of 3% and a strength retention rate of 95% can be obtained. On the other hand, when the content of polyethylene terephthalate in polyphenylene sulfide is increased as in Comparative Example 1, the strength retention tends to be greatly reduced. More preferably, it is 85 to 100%.

  The polyarylene sulfide fiber of the present invention preferably has a strength retention of 90 to 100% when immersed in a 30% aqueous sodium hydroxide solution at 93 ° C. for 24 hours. Originally, polyarylene sulfide fiber is a fiber having high resistance to alkali. However, when polyester having low alkali resistance is mixed with the arylene sulfide fiber, the polyester component is decomposed by alkali and the strength of the fiber tends to be lowered. However, the fiber of the present invention succeeded in improving the alkali resistance by optimizing the content of polyalkylene terephthalate. Surprisingly, it has been found that the alkali resistance is improved as compared with the PPS fiber not added with polyalkylene terephthalate. The mechanism is not clear, but in the fiber of the present invention, polyalkylene terephthalate is not caused by fiber strength, and by adding polyalkylene terephthalate, the fiber structure becomes dense and fiber strength after alkali treatment I think that it is suppressing the decline. More preferably, it is 95 to 100%.

  The method for producing the fiber of the present invention is not particularly limited, and examples thereof include a blending method in a spinning machine and a method in which polyarylene sulfide and polyalkylene terephthalate are melt-kneaded in advance and then fiberized. In particular, polyarylene sulfide and polyalkylene terephthalate are pre-blended and then fiberized, which is more preferable because the fiber of the present invention can be easily obtained.

  The shape of the polyarylene sulfide used in the production of the fiber of the present invention is not particularly limited. For example, in PPS, the resin shape is granular or powder according to a known production method, so that it may be used as it is. Moreover, after making into the shape of flakes and a pellet once, you may use.

  The shape of the polyalkylene terephthalate resin used in the present invention is not particularly limited, and examples thereof include pellets, flakes, granules, and powders.

  The method of melt kneading is not particularly limited, and a known heat melt mixing apparatus can be used.

  As the heat-melting and mixing apparatus, a single-screw extruder, a twin-screw extruder, a multi-screw extruder provided with three or more screws, a combination multi-screw extruder, a kneader / ruder, or the like can be used. Among these, a twin screw extruder is preferably used because the dispersibility of polyarylene sulfide and polyalkylene terephthalate is improved, and the spinnability is improved. More preferably, a twin screw extruder having two or more kneading zones is used.

  In the melt-kneading method, the method of supplying the polyarylene sulfide and polyalkylene terephthalate to the kneading machine at the time of kneading is not particularly limited. For example, the method of pre-blending the polyarylene sulfide and polyalkylene terephthalate and supplying it to the kneading machine, Examples thereof include a method in which each of arylene sulfide and polyalkylene terephthalate is fed to a kneader while being metered, and a method in which polyalkylene terephthalate is fed by side feed to a kneader to which polyarylene sulfide has been fed.

  The melt kneading temperature is preferably melt kneading at 280 to 350 ° C. The temperature here is the temperature of the resin at the kneading part or the kneader tip. Usually, it can be measured by attaching a thermometer to the tip of the kneader. It is preferable that the temperature of the melt-kneading be in this range, since the quality such as spinning stability, the strength and color tone of the obtained fiber will be improved.

  The kneading time is not particularly limited, but is preferably 0.5 to 30 minutes. By setting the kneading time within this range, it is preferable because both dispersibility and suppression of thermal decomposition of polyarylene sulfide can be achieved, and the spinning stability, the strength and color tone of the resulting fiber, etc. are improved.

  The fiber of the present invention is preferably melt-spun at a spinning temperature of 285 to 310 ° C. after the melt-kneading. This temperature range is preferable because both the fluidity of the polymer and the generation amount of volatile components such as organic low-polymerization products and decomposition products can be compatible, and fibers can be produced stably. A more preferable spinning temperature is 285 to 300 ° C.

  In the method for producing the polyarylene sulfide fiber of the present invention, there is no particular limitation as long as it is melt-spun by the melt spinning step after the melt-kneading step. Specifically, for example, PPS resin and polyalkylene terephthalate resin may be pre-melted and kneaded with an extruder, or a master batch containing polyalkylene terephthalate resin at a high concentration may be prepared and used in the spinning process. You may dilute to arbitrary density | concentrations. Further, the kneading machine may be directly connected to the spinning machine, and the kneaded melt may be directly spun without obtaining pellets.

  In the spinning process, in order to prevent gelation due to thickening, it is desirable to heat to the spinning temperature in a nitrogen atmosphere and discharge from the die. A die used for ordinary melt spinning, for example, one having a discharge hole diameter D of 0.15 to 5 mmφ and a discharge hole depth L of about 0.2 to 2.0 mm is preferably used.

  The yarn discharged from the die is usually cooled by chimney wind or warm water after spinning at a wind speed of 5 to 100 m / min, and is obtained by winding an appropriate amount of oil agent as a sizing agent in multifilament or single fiber. .

  In addition, it is preferable that the spinning speed is set to 500 m / min to 10000 m / min because molecular orientation occurs, and the process passability in the subsequent stretching process can be improved. In the present invention, the spinning speed refers to the peripheral speed of the first godet roller for taking up the yarn.

  In addition, as a manufacturing process, a method such as a method of once winding and drawing using a known drawing machine, or a process such as a direct spinning drawing method in which a spinning drawing process is continuously performed without winding up can be applied.

  Furthermore, when producing short fibers, if necessary, the yarn obtained by spinning is drawn in a warm water bath or on a hot plate at an appropriate magnification, and then, if necessary, a stuffing box type crimper. Then, crimping is performed, relaxation heat treatment is performed at a predetermined temperature, and after the oil agent is applied, the fiber is cut into a predetermined length to obtain a short fiber.

  The polyarylene sulfide fibers of the present invention can be suitably used in various fabric forms such as woven fabrics, knitted fabrics, nonwoven fabrics, piles and cotton as fiber structures, and natural fibers, regenerated fibers, semi-finished fibers can be combined. Synthetic fibers, synthetic fibers and the like can be mentioned, and drawing, twisting, and blending may be performed. Other fibers to be combined include natural fibers such as cotton, hemp, wool, and silk, regenerated fibers such as rayon and cupra, semi-synthetic fibers such as acetate, and synthetic fibers such as nylon, polyester, polyacrylonitrile, and polyvinyl chloride. Etc. are applicable. In applications where chemical resistance and heat resistance are required, the fiber of the present invention can be used alone.

  In the form of a woven fabric as the fiber structure of the present invention, for example, it may be woven into a woven fabric such as a triple structure or a change structure that is a single structure, a weft double structure or a vertical structure that is a double structure. The mass of the fabric at this time is preferably in the range of 50 g / m 2 or more and 1500 g / m 2 or less.

  The polyarylene sulfide fiber of the present invention is a fiber having excellent heat resistance and chemical resistance, and is excellent in economic efficiency. Therefore, a bag filter, a motor binding string, a motor binder tape, a paper dryer dryer canvas, and a thermal bond method nonwoven fabric. It can be suitably used for applications such as a net conveyor for a thermal bonding process, a conveyor belt in a dryer or a heat treatment machine, and a filter.

The present invention will be specifically described below with reference to examples. In addition, the material characteristic in an Example was performed with the following method.
(1) Crystallization temperature (Tc) and crystallization peak half width (D)
It was measured and calculated according to JIS-K-7122 (1987) using differential scanning calorimetry (DSC). First, the fiber was kept at 320 ° C. for 5 minutes to be completely melted, and then rapidly cooled with liquid nitrogen so that no crystals remained in the resin. Subsequently, the temperature of the exothermic peak observed when the temperature was raised from 50 ° C. to 320 ° C. at 16 ° C./min was determined.

Apparatus: DSC Q2000 manufactured by TA Instruments
Data analysis: Universal Analysis 2000 from TA Instruments
(2) Strength (cN / dtex), elongation (%)
In accordance with the method of JIS L 1013, the measurement was performed under conditions of a test length of 25 cm and a tensile speed of 30 cm / min.
(3) Yarn spots U% (%)
Measurement was performed in the normal mode at a yarn feeding speed of 200 m / min using a USTER TESTER 4 manufactured by Zerbegger Worcester.
(4) Crimp degree (%)
A short fiber is randomly extracted from the sample, one end of this short fiber is fixed, a load of 2 mg / d and 300 mg / d is applied to the other end, the fiber lengths at that time are measured, and the degree of crimp is determined by the following equation: calculate. The number of tests is 10, and the average value is shown.
Crimp degree [%] = 100 (B−A) / B
However, A and B shall be shown below.
A: Fiber length when a load of 2 mg / d is applied [mm]
B: Fiber length [mm] when a load of 300 mg / d is applied
(5) Knot strength, hook strength Based on the method of JIS L 1013, measurement was performed under conditions of a test length of 25 cm and a pulling speed of 30 cm / min.
(6) Heat shrinkage rate after heat treatment at 180 ° C., strength retention rate Heat shrinkage rate with respect to initial length after being left in an oven for 24 hours after the temperature of heat shrinkage rate is adjusted to 180 ° C. as an index of heat stability (%) As sought.

Further, the strength of the fiber after the heat treatment was measured and obtained as a strength retention (%) with respect to the initial strength.
(7) NaOH treatment strength retention rate As an indicator of alkali resistance, fibers were immersed in a 30% NaOH aqueous solution. Thereafter, the aqueous NaOH solution was heated, the strength of the fiber after heat treatment at 93 ° C. for 24 hours was measured, and the strength retention rate (%) with respect to the initial strength was obtained.
Reference example 1
PPS (E2280, manufactured by Toray Industries, Inc.) was supplied to a spinning machine to which a twin-screw kneading extruder was connected. The twin-screw kneading extruder connected to the spinning machine was set to a set temperature of 320 ° C. and a shear rate of 100 sec ⁻¹ . Further, spinning was performed under the conditions of a spinning temperature of 320 ° C., a nozzle diameter of 0.23 mm, a nozzle hole number of 24 holes, and 800 m / min to obtain an undrawn yarn.

  Next, the obtained undrawn yarn was drawn 3.8 times at a drawing temperature of 90 ° C., and subjected to relaxation treatment under conditions of 0.98 times after heat setting at 235 ° C. to obtain a drawn yarn.

The results are shown in Table 1.
Example 1
Pent (95% by weight, manufactured by Toray Industries, Inc., E2280) and 5% by weight of polyethylene terephthalate (manufactured by Toray Industries, Inc., hereinafter abbreviated as PET) with an intrinsic viscosity of 0.65, bent type biaxial heated to 320 ° C. The mixture was supplied to a kneading extruder and melt-extruded at a shear rate of 100 sec ⁻¹ and a residence time of 1 minute to obtain polymer chips of 95% by weight of PPS and 5% by weight of PET.

Subsequently, the obtained polymer chip was vacuum-dried at 150 ° C. for 10 hours, and supplied to a spinning machine connected with a twin-screw kneading extruder. The twin-screw kneading extruder connected to the spinning machine was set to a set temperature of 300 ° C. and a shear rate of 100 sec ⁻¹ . Further, spinning was performed under the conditions of a spinning temperature of 295 ° C., a nozzle diameter of 0.23 mm, a nozzle hole number of 24 holes, and 800 m / min to obtain an undrawn yarn.

  Next, the obtained undrawn yarn was drawn 3.8 times at a drawing temperature of 90 ° C., and heat-set at 235 ° C. and then subjected to a relaxation treatment under conditions of 0.98 times to obtain a drawn yarn. The results are shown in Table 1.

When the thermal stability of the obtained fiber was measured, the shrinkage rate at 180 ° C. and the strength retention rate were very high, and high dimensional stability and strength retention rate were obtained even when compared with the single PPS yarn (Reference Example 1). Obtained. Further, the strength retention after NaOH treatment, which is an index of alkali resistance, was also high, and the alkali resistance was higher than that of the single PPS yarn (Reference Example 1).
Examples 2, 3 and Comparative Example 1
The same procedure as in Example 1 was conducted except that PET was changed to polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), and polypropylene (PP). The results are shown in Table 1. The material changed to PP (Comparative Example 1) was low in thermal dimensional stability (high shrinkage), greatly reduced in strength retention after 180 ° C. heat treatment, and deviated from the practical range.

Examples 4-6, Comparative Example 2
The same procedure as in Example 1 was performed except that the ratio of PPS and PET was changed. The results are shown in Table 2. In Comparative Example 2 in which the amount of PET was 10% by weight, the thermal dimensional stability was low (the shrinkage rate was large), and the strength retention after the heat treatment at 180 ° C. was lowered. In addition, the alkali resistance was greatly reduced, and was out of the practical range.

Reference example 2
PPS (E2280, manufactured by Toray Industries, Inc.) was supplied to a spinning machine to which a twin-screw kneading extruder was connected. The twin-screw kneading extruder connected to the spinning machine was set to a set temperature of 320 ° C. and a shear rate of 100 sec ⁻¹ . Further, spinning was performed under the conditions of a spinning temperature of 320 ° C., a base diameter of 0.23 mm, a base hole number of 100 holes, and 800 m / min to obtain an undrawn yarn.

Subsequently, the obtained undrawn yarn was drawn in hot water at a temperature of 98 ° C. with a draw ratio of 3.2 times, then relaxed by 2% between the hot drawing and the constant-length heat treatment, constant-length heat treatment and crimping. A constant-length heat treatment was performed for 4 seconds with a roller heated to 200 ° C. under the condition of 2% relaxation before application. After that, crimping was performed with steam at 210 ° C. in a stuffing box type crimper, heat fixing, oil agent was applied, dried at 90 ° C., and then cut to a length of 51 mm to obtain PPS short fibers. The results are shown in Table 3.
Example 7
Pent (95% by weight, manufactured by Toray Industries, Inc., E2280) and 5% by weight of polyethylene terephthalate (manufactured by Toray Industries, Inc., hereinafter abbreviated as PET) with an intrinsic viscosity of 0.65, bent type biaxial heated to 320 ° C. The mixture was supplied to a kneading extruder and melt-extruded at a shear rate of 100 sec ⁻¹ and a residence time of 1 minute to obtain polymer chips of 95% by weight of PPS and 5% by weight of PET.

Subsequently, the obtained polymer chip was vacuum-dried at 150 ° C. for 10 hours, and supplied to a spinning machine connected with a twin-screw kneading extruder. The twin-screw kneading extruder connected to the spinning machine was set to a set temperature of 300 ° C. and a shear rate of 100 sec ⁻¹ . Further, spinning was performed under the conditions of a spinning temperature of 295 ° C., a nozzle diameter of 0.23 mm, a nozzle hole number of 100 holes, and 800 m / min to obtain an undrawn yarn.

  Subsequently, the obtained unstretched yarn was stretched in warm water at a temperature of 98 ° C. with a stretch ratio of 3.2 times, and then relaxed by 2% between the heat stretching and constant length heat treatment, constant length heat treatment and crimping. A constant-length heat treatment was performed for 4 seconds with a roller heated to 200 ° C. under the condition of 2% relaxation before application. After that, crimping was performed with steam at 210 ° C. in a stuffing box type crimper, heat fixing, oil agent was applied, dried at 90 ° C., and then cut to a length of 51 mm to obtain PPS short fibers. The results are shown in Table 3.

When the thermal stability of the obtained fiber was measured, the shrinkage rate and strength retention at 180 ° C. were high, and high dimensional stability and strength retention were obtained even when compared with the PPS single yarn (Reference Example 2). . Further, the strength retention after NaOH treatment, which is an index of alkali resistance, was higher than that of the single PPS yarn (Reference Example 2), and the alkali resistance was high.
Examples 8 and 9, Comparative Example 3
The same procedure as in Example 7 was conducted except that PET was changed to polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), and polypropylene (PP). The results are shown in Table 3. Comparative Example 3 changed to PP had low thermal dimensional stability (high shrinkage), greatly reduced strength retention after 180 ° C. heat treatment, and was out of the practical range.

Examples 10-12, Comparative Example 4
It carried out like Example 7 except having changed the ratio of PPS and PET. The results are shown in Table 4. In Comparative Example 4 in which the amount of PET was 10% by weight, the thermal dimensional stability was low (the shrinkage rate was large), and the strength retention after 180 ° C. heat treatment was reduced. In addition, the alkali resistance was greatly reduced, and was out of the practical range.

Reference example 3
PPS (E2280, manufactured by Toray Industries, Inc.) was supplied to a spinning machine to which a twin-screw kneading extruder was connected. The twin-screw kneading extruder connected to the spinning machine was set to a set temperature of 320 ° C. and a shear rate of 100 sec ⁻¹ . Further, the spinning temperature was 320 ° C., the fiber was extruded from the die into a fiber shape, and cooled with hot water at 80 ° C. Next, the cooling yarn was first stretched 3.8 times in a pressurized saturated steam atmosphere with a gauge pressure of 1.96 kPa for 4.1 seconds, and secondarily stretched 1.2 times in hot air at 150 ° C. Subsequently, relaxation heat treatment was performed at 140 ° C. and 0.98 times to obtain a monofilament having a circular cross section with a diameter of 0.45 mm. The results are shown in Table 5.
Example 13
Pent (95% by weight, manufactured by Toray Industries, Inc., E2280) and 5% by weight of polyethylene terephthalate (manufactured by Toray Industries, Inc., hereinafter abbreviated as PET) with an intrinsic viscosity of 0.65, bent type biaxial heated to 320 ° C. The mixture was supplied to a kneading extruder and melt-extruded at a shear rate of 100 sec ⁻¹ and a residence time of 1 minute to obtain polymer chips of 95% by weight of PPS and 5% by weight of PET.

Subsequently, the obtained polymer chip was vacuum-dried at 150 ° C. for 10 hours, and supplied to a spinning machine connected with a twin-screw kneading extruder. The twin-screw kneading extruder connected to the spinning machine was set to a set temperature of 320 ° C. and a shear rate of 100 sec ⁻¹ . Further, the spinning temperature was 320 ° C., the fiber was extruded from the die into a fiber shape, and cooled with hot water at 80 ° C.

  Next, the cooling yarn was first stretched 3.8 times in a pressurized saturated steam atmosphere with a gauge pressure of 1.96 kPa for 4.1 seconds, and secondarily stretched 1.2 times in hot air at 150 ° C. Subsequently, relaxation heat treatment was performed at 140 ° C. and 0.98 times to obtain a monofilament having a circular cross section with a diameter of 0.45 mm. The results are shown in Table 5.

The strength retention after NaOH treatment, which is an index of alkali resistance of the obtained fiber, was high, and the alkali resistance was higher than that of the single PPS yarn (Reference Example 3).
Examples 14 and 15 and Comparative Example 5
The same procedure as in Example 13 was performed except that PET was changed to polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), and polypropylene (PP). The results are shown in Table 5. The material changed to PP (Comparative Example 5) had low thermal dimensional stability (high shrinkage), greatly reduced strength retention after 180 ° C. heat treatment, and was out of the practical range.

Examples 16-18, Comparative Example 6
The same procedure as in Example 13 was performed except that the ratio of PPS and PET was changed. The results are shown in Table 6. In Comparative Example 6 in which the amount of PET was 10% by weight, the thermal dimensional stability was low (high shrinkage), and the strength retention after 180 ° C. heat treatment was reduced. In addition, the alkali resistance was greatly reduced, and was out of the practical range.

Claims (11)

A fiber comprising a blend polymer of 92 to 99.9% by weight of polyarylene sulfide and 0.1 to 8% by weight of polyalkylene terephthalate. After being melted at 320 ° C. for 5 minutes and rapidly cooled with liquid nitrogen, the crystallization temperature (Tc) measured by differential scanning calorimetry (DSC) at a heating rate of 16 ° C./min is 90 to 130 ° C. The fiber according to claim 1. After melting at 320 ° C. for 5 minutes and quenching with liquid nitrogen, the full width at half maximum (D) of the crystallization temperature peak measured by differential scanning calorimetry (DSC) at a heating rate of 16 ° C./min is 5 ° C. or less. The fiber according to claim 1 or 2, wherein The fiber according to any one of claims 1 to 3, wherein the polyalkylene terephthalate is a reethylene terephthalate having 90% or more of an ethylene terephthalate unit. The fiber according to any one of claims 1 to 4, wherein the polyphenylene sulfide is polyphenylene sulfide. The fiber according to any one of claims 1 to 5, wherein the fiber is a multifilament, and the physical properties of the multifilament exhibit the following characteristics.
Strength 2.0-8.0cN / dtex
Elongation 20-80%
Yarn spot U% 0.1-2.0% The fiber according to any one of claims 1 to 5, wherein the fiber has a fiber length of 3 to 200 mm, and physical properties of the short fiber exhibit the following characteristics.
Strength 2.0-8.0cN / dtex
Elongation 20-80%
Crimp degree 3-35% The fiber according to any one of claims 1 to 5, wherein the fiber is a monofilament having a diameter of 0.05 to 4.00 mm, and the physical properties of the monofilament exhibit the following characteristics.
Strength 2.0-8.0cN / dtex
Nodule strength 1.5-4.5 cN / dtex
Hatch strength is 2.0-10.0 cN / dtex The fiber according to any one of claims 1 to 8, wherein the fiber characteristics after heat treatment at 180 ° C for 24 hours are as follows.
Shrinkage rate 0-10%
Strength retention 80-100% The fiber according to any one of claims 1 to 9, which has a strength retention of 90 to 100% when immersed in a 30% aqueous sodium hydroxide solution at 93 ° C for 24 hours. A fiber structure comprising the fiber according to any one of claims 1 to 10.