JP2002038332A - Polyphenylene sulfide yarn, method for producing the same and industrial woven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a PPS yarn having fiblilizing resistance and wear resistance against repeated bendings, to provide a method for efficiently. producing the same and to obtain various kinds of industrial woven fabrics. SOLUTION: A PPS undrawn yarn is subjected to a primary drawing in an atmosphere of a saturated steam under a pressure to give the PPS yarn having high bending durability, suitable as various kinds of industrial woven fabrics.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a polyphenylene sulfide fiber excellent in flex wear and flex durability.
In particular, the present invention relates to industrial fabrics such as monofilaments, an efficient production method thereof, and a papermaking dryer canvas using the polyphenylene sulfide fiber, a net conveyor for a thermal bonding nonwoven fabric heat bonding process, a belt or a filter for transport in a dryer and a heat treatment machine. is there.

[0002]

2. Description of the Related Art Polyphenylene sulfide (hereinafter referred to as P
PS) is a polymer with excellent heat resistance and chemical resistance, and is widely used as a variety of molded products such as industrial parts, fibers, industrial fabrics, films, sheets and plates, taking advantage of these excellent properties. Has been used.

However, fibers made of PPS, particularly monofilaments, are inferior not only in abrasion resistance (hereinafter, referred to as bending abrasion resistance) when repeatedly bent and rubbed, but also when the warp is woven into an industrial fabric. There is a problem that the bending durability is inferior, such as cracking in the direction, and improvement of these problems has been demanded conventionally.

Various studies have been made on techniques for improving various properties of PPS fibers, particularly monofilaments. For example, Japanese Patent Application Laid-Open No. 62-299513 discloses a melt flow rate (hereinafter, referred to as MFR). 20
The linear unstretched monofilament obtained by melt-extruding a linear PPS of 0 or less and cooling in hot water of 60 ° C. or higher is subsequently cooled to obtain a ratio of primary draw ratio / total draw ratio of 0.1.
After primary stretching at a primary stretching ratio of less than 88, the film is stretched in multiple stages so that the total stretching ratio is 4 times or more.
A method for producing a PPS monofilament having improved tensile strength and knot strength by performing relaxation heat treatment in an air bath at -280 ° C is disclosed.

[0005] Also, Japanese Patent Publication No. 64-3961 discloses that
After stretching the unstretched PPS yarn in one step at a draw ratio higher than the natural draw ratio, heat it at a constant length at 150 to 260 ° C and higher than the draw temperature in the first step, or draw the first draw in the same temperature range with a total draw ratio of the first step. A method for improving the mechanical properties, heat resistance, and chemical resistance of PPS fibers by performing two-stage drawing so as to have a magnification of 1 to 2 times is disclosed.

Further, JP-A-2-53913 discloses that a composition obtained by blending an ionomer with PPS of MFR160 is melt-spun and quenched in a hot water bath at 85 ° C.
First stretched 4.7 times in a steam bath at 0 ° C, and then 160 ° C
Stretched 1.269 times in an air bath of
A method for improving the flex wear property, flex fatigue property and mechanical properties of a PPS monofilament by performing a relaxation heat treatment at a draw ratio of 0.97 times in an air bath at 0 ° C. is disclosed.

Further, Japanese Patent Application Laid-Open No. Hei 4-222217 discloses that the PPS monofilament is subjected to a heat treatment for a short time at a high temperature containing the melting point of PPS or more in a drawing or heat setting step at the time of spinning of the PPS monofilament. And methods for improving flex fatigue and mechanical properties.

However, the PPS monofilament obtained by the above-mentioned conventional methods, particularly the methods described in JP-A-2-53913 and JP-A-4-222217, has a bending wear property, that is, a reciprocating movement until cutting in a bending wear test. The number of wear was about 4500 at most, and further improvement was required.

Further, the PPS monofilament obtained by the method described in the above-mentioned JP-A-2-53913 is
Since it is essential to contain ionomer, it is a monofilament substantially composed of 100% PPS, and has further improved flex wear and flex fatigue.
The realization of monofilaments has always been desired.

Furthermore, the method described in the above-mentioned Japanese Patent Application Laid-Open No. 4-222217 discloses a method in which PPS is used in a stretching or heat setting step.
A high temperature including the melting point or higher, it is difficult to obtain suitable conditions and has a problem of low productivity, and PP having further improved flex wear and flex fatigue.
Producing S monofilaments by more efficient methods has been a major challenge in the art.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems in the prior art, and has excellent mechanical properties such as tensile strength, tensile elongation and hooking strength. It is another object of the present invention to provide a PPS fiber having more excellent flex wear and flex durability than conventional ones, an efficient production method thereof, and various industrial fabrics using the PPS fiber.

[0012]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above-mentioned object, and as a result, after melt-spinning and cooling PPS, primary stretching was performed under specific conditions in a pressurized saturated steam atmosphere. Surprisingly, the present inventors have found that PPS fibers having remarkably improved flex wear resistance and flex durability and having sufficiently high mechanical properties can be obtained, and have reached the present invention.

That is, the PPS fiber of the present invention is JIS
Tensile strength measured according to the provisions of L1013 is 2.6
5 cN / dtex or more, the tensile elongation is 30% or more,
Similarly, the hooking strength is 3.53 cN / dtex or more,
In addition, the number of reciprocating wears before cutting in a bending wear test measured under the conditions described below according to the provisions of JIS L-1095-7.10.2B is 7000 or more,
The number of reciprocating bendings before cutting in the bending fatigue test measured under the conditions described below according to the provisions of 8115 is 15
It is characterized by being zero or more times.

[0014] In the PPS fiber of the present invention, the number of reciprocating wears before cutting in the bending wear test is 85.
00 times or more, the number of reciprocating bendings before cutting in the bending fatigue test is 200 times or more, the melt flow rate is 180 g / 10 minutes or less, and substantially consists of polyphenylene sulfide having a linear molecular structure;
And monofilaments having a diameter of 0.050 mm to 4.00 mm are both preferred conditions.

Further, the method for producing a PPS fiber of the present invention comprises:
Unstretched obtained by melt-extruding polyphenylene sulfide having a melt flow rate of 180 g / 10 min or less and having a substantially linear molecular structure, and cooling it in hot water at 70 ° C. or higher through an air layer or an inert gas layer. Subsequently, the yarn is primarily stretched in a saturated steam atmosphere at a gauge pressure of 0.98 to 98 kPa in a range of 3.0 to 4.1 times in 0.1 to 20.0 seconds, and further drawn in a range of 110 to 160 times. The total stretching ratio is 4.0 to 1.8 times in an atmosphere of 40 ° C.
After multi-stretching to a ratio of 1 to 7.0 times,
It is characterized by performing a relaxation heat treatment at 0.75 to 1.00 times in an atmosphere of １７175 ° C.

In the method for producing a PPS fiber according to the present invention, the primary drawing is performed under a gauge pressure of 0.98 to 49 kP.
It is more preferable to perform the treatment in a saturated steam atmosphere of a for 0.5 to 10.0 seconds.

Further, the industrial woven fabric of the present invention is characterized in that at least a part of the weft and / or warp constituting the woven fabric is made of the above-mentioned PPS fiber. When applied to a net conveyor for a bonding process, a conveyor belt or a filter in a dryer and a heat treatment machine, an optimum effect is exhibited.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The PPS fiber of the present invention is JIS L101
3. The tensile strength measured according to the provisions of 3. is 2.65 cN / d
tex or more, similarly, the tensile elongation is 30% or more, preferably 35% or more, more preferably 40% or more, and the hooking strength is also 3.53 cN / dtex or more, preferably 3.97.
cN / dtex or more and JIS L-109
The number of reciprocating wears before cutting in the bending wear test measured under the conditions described below according to the provisions of 5-7.10.2B is 7
000 times or more, preferably 7500 times or more, more preferably 8500 times or more, the number of reciprocating bending until cutting in the bending fatigue test measured under the conditions described below according to the provisions of JIS P-8115 is 150 times or more, preferably It has excellent properties that have not been hitherto, such as 200 times or more.

The PPS constituting the PPS fiber of the present invention is a polymer in which 90% or more of the repeating units of the polymer are composed of p-phenylene sulfide.
-It can be obtained by subjecting dichlorobenzene to polycondensation reaction of sodium sulfide. Also, one of p-dichlorobenzene
It may be a polymer obtained by copolycondensation of less than 0 mol% of trichlorobenzene as a branching component.

The raw material PPS has an MFR of 18
Those having a molecular weight of 0 g / 10 min or less, particularly 150 g / 10 min or less and having a substantially linear molecular structure are preferably used.

Here, the MFR is ASTM D123
316 ° C, orifice diameter 2.09 according to 8-86
It is a value measured under the conditions of 5 mm, orifice length 8.00 mm, and load 5 Kg, and is expressed by the amount of polymer flowing out (g) per 10 minutes.

When the PPS is obtained by merely washing the PPS after the polycondensation with water, the PPS mainly has a sodium carboxylate terminal group at the terminal. The PPS after polycondensation washed with an aqueous acetic acid solution and then with water has a carboxylic acid terminal group at the terminal. Furthermore, the PPS after polycondensation washed with an aqueous solution of calcium acetate and then washed with water has a calcium carboxylate terminal group at the terminal. However, a small amount of PPS having a carboxylic acid end group is -COO.
It may have a Na terminal group, and the PPS having a carboxylic acid metal terminal group may have a small amount of a carboxylic acid terminal group.

The PPS constituting the PPS fiber of the present invention is
Commercial products can be obtained and used. PPS
As a commercially available product, for example, E1880 (MFR: 70) manufactured by Toray Co., Ltd., which is a PPS having a carboxylic acid metal terminal group.
g / 10 min), E2080 (MFR: 100 g / 10 min)
Min), E2280 (MFR: 170 g / 10 min) and M2588 (MFR: 300 g / 10 min).

The PPS is usually a polymer obtained as a powder, but before being subjected to melt spinning, the powder PPS is heated to a temperature higher than the melting point by an extruder or the like and melted and kneaded. It can be processed into pellets by a method such as filtration to remove foreign substances, extrusion into a gut shape, cooling and cutting, and the like.

Further, in order to remove oligomers from the PPS powder or PPS pellet, the PPS powder or PPS pellet is subjected to a reduced pressure at about 100 to 180 ° C. for 1 to 24 hours before being subjected to molding such as melt spinning. And dried.

The raw material PPS used in the present invention includes various inorganic particles such as titanium oxide, silicon oxide, calcium carbonate, silicon nitride, clay, talc, kaolin and zirconate, and particles such as cross-linked polymer particles. Conventionally known antioxidants, sequestering agents, ion exchange agents, coloring inhibitors, lightfasteners, inclusion compounds, various coloring agents, waxes, silicone oils, various surfactants, various reinforcing fibers, fluororesins , Polyesters, polyamides, polyolefins, polystyrenes and the like may be added.

Next, a method for producing a PPS fiber having the above excellent characteristics will be described.

In the method for producing PPS fiber of the present invention, PPS is melt-spun.
FR is 180 g / 10 min or less, particularly 1 g as described above.
Those having 50 g / 10 min or less are preferred.

First, a melt temperature of about 285 to 3 was measured by an extruder.
PPS melted at 50 ° C. is extruded from a nozzle and cooled in hot water at 70 ° C. or higher via an air layer or an inert gas layer. Next, the obtained undrawn yarn is subsequently subjected to a gauge pressure of 0.98 to 98 kPa, preferably a gauge pressure of 0.98 to 98 kPa.
49 kPa, under a pressurized saturated steam atmosphere, and 0.1 to
The primary stretching is performed for 3.0 to 4.1 times for 20.0 seconds, preferably for 0.5 to 10.0 seconds. Then 110
Under an atmosphere at a temperature of from 160 to 160 ° C., preferably from 110 to 150 ° C., the total stretching ratio is 4.0 to 1.0 to 1.8.
Multi-stage stretching so as to increase the magnification by a factor of 1 to 7.0.
PPS having both flexural durability and tough mechanical properties by performing a relaxation heat treatment at 0.75 to less than 1.00 in an atmosphere of from 175 to 175 ° C, preferably from 110 to 160 ° C.
Fiber can be obtained.

The most characteristic feature of the method for producing PPS fiber of the present invention is that the undrawn yarn is primarily drawn in a pressurized saturated steam atmosphere. Specifically, the gauge pressure is 0.98 to 9
8 kPa, preferably in a pressurized saturated steam atmosphere with a gauge pressure of 0.98 to 49 kPa, and for 0.1 to 20.0 seconds,
Preferably between 3.0 and 4.0 for 0.5 to 10.0 seconds.
The primary stretching is to be performed once.

When the gauge pressure of the pressurized saturated water vapor pressure in the primary stretching is less than the above range, the bending durability is lowered. When the gauge pressure exceeds the above range, a super draw is generated and stable. The stretching cannot be performed.

If the stretching time is less than the above range, the bending durability is lowered. If the stretching time exceeds the above range, a super draw occurs, and the stable stretching cannot be performed as described above.

Accordingly, the conditions of the gauge pressure and the drawing time of the above-mentioned pressurized saturated steam pressure in the primary drawing are such that the PPS fiber is capable of performing stable drawing, and has both excellent bending durability and strong mechanical properties. This is an important condition for obtaining.

Further, in the multi-stage stretching, the temperature after the second stretching is 110 to 160 ° C., preferably 110 to 160 ° C.
When the stretching temperature is lower than the above range, thread breakage occurs and stable yarn-making properties cannot be obtained, and when the drawing temperature is higher than the above range, the bending durability decreases. Will be invited. Although the cause is not clear at present, it is supposed that this is a phenomenon that occurs because the crystallization of the amorphous part is promoted by the high heat history and the flexibility is impaired. Under this temperature atmosphere, by performing multi-stage stretching in a range of 1.0 to 1.8 times so that the total stretching ratio becomes 4.0 to 7.0 times, bending durability and tough mechanical properties are obtained. A PPS fiber having both of the above is obtained.

Next, in performing the relaxation heat treatment,
The heat treatment must be performed in an atmosphere at 110 to 175 ° C, preferably 110 to 160 ° C. If the heat treatment temperature is lower than the above range, sufficient heat treatment is not performed.
It is not preferable because bending durability is lowered. Although the cause is not clear at present, it is supposed that this is a phenomenon that occurs because the crystallization of the amorphous part is promoted by the high heat history and the flexibility is impaired. Under this atmosphere,
By performing the relaxation heat treatment under the condition of 0.75 or more and less than 1.00, a PPS fiber having both bending durability and strong mechanical properties can be obtained.

Thus, the PPS fiber obtained by the production method of the present invention is a novel fiber having excellent physical properties as described above.

The reason why the bending durability of the PPS fiber is remarkably improved by the above-mentioned production method is not yet clear, but very low crystal, non-oriented unstretched yarn may be used in a pressurized saturated steam atmosphere. By stretching under abundant heat conditions, the amorphous part looks like low-oriented amorphous, and the crystalline part is formed as oriented crystal, so the fiber has both flexible bending durability and strong mechanical properties. Is estimated to be formed.

The PPS fiber of the present invention has a diameter of 0.050.
A particularly excellent effect is exhibited when a monofilament having a diameter of from 4.0 mm to 4.00 mm is used, but a multifilament other than the monofilament is also included. The form of the fiber includes various forms such as a core-sheath composite yarn, a sea-island composite yarn, a bimetal composite yarn, and a multilayer composite yarn in addition to a single structure.

The PPS monofilament referred to in the present invention is:
It is a continuous yarn composed of one single yarn.

The P of the present invention represented by a monofilament
The cross-sectional shape (hereinafter, referred to as cross-sectional shape or cross-section) of the PS fiber perpendicular to the fiber axis direction is a circle, a flat, a square, a half-moon, a triangle, a polygon having five or more angles, a multilobe, a dogbone, a cocoon shape. Any cross-sectional shape may be used.
When the PPS fiber represented by the monofilament of the present invention is used as a constituent material of an industrial fabric, it is preferable that the cross-sectional shape of the fiber is a circle or a flat shape. In particular, when the PPS monofilament is used as the warp of a papermaking dryer canvas, a monofilament having a flat cross-sectional shape is preferably used from the viewpoint of effectively exhibiting antifouling properties and the flatness of the canvas. The flat in the present invention is an ellipse, a square or a rectangle, but in addition to a mathematically defined exact ellipse, a square or a rectangle, a shape generally similar to an ellipse, a square or a rectangle, for example, a square and a rectangle. It includes a shape with rounded corners. In the case of an ellipse, the length of the major axis (LD) and the length of the minor axis (SD) that intersect at right angles at the center of the ellipse satisfy the following equation. It is preferable that the length (LD) of the long side and the length (SD) of the short side of the rectangle satisfy the relationship of 1.0 ≦ LD / SD ≦ 10, respectively.

The length of the line segment passing through the center of gravity of the cross section of the PPS monofilament can be appropriately selected depending on the application, but is preferably in the range of 0.05 to 4.0 mm.

The industrial fabric of the present invention refers to a papermaking drier canvas using the PPS fiber represented by the monofilament of the present invention for at least a part of the weft and / or warp of the fabric, for a thermal bonding nonwoven fabric heat bonding process. It refers to a conveyor belt or various filters in a net conveyor, a dryer, and a heat treatment machine, and these industrial fabrics exhibit useful properties such as excellent bending durability, heat resistance, and chemical resistance.

Here, the papermaking dryer canvas is
Various types of fabrics, including plain weave, double weave and triple weave (including repetitive spiral fabrics in which successive spiral yarn monofilaments are interlocked, and the interlocking part is interwoven by almost straight monofilaments) Fabric used to dry paper in a dryer. Further, the belt fabric for the heat bonding process of the nonwoven fabric is a woven fabric for passing the nonwoven fabric through a furnace in order to fuse the heat bonding fibers such as polyethylene having a low melting point which constitute the nonwoven fabric. It is a woven fabric such as a heavy weave. Further, the conveyor belt in the dryer and the heat treatment machine refers to a woven fabric that conveys the semi-finished product in a high-temperature zone for drying, heat curing, sterilizing, heating cooking, and the like of various semi-finished products. Furthermore, various filters are woven fabrics used for filtering high-temperature liquids, gases, powders, and the like.

[0045]

EXAMPLES Examples are given below to illustrate P which is represented by a monofilament which is one of preferred forms of the fiber of the present invention.
The PS fiber, the industrial fabric using the PPS fiber, and the method for producing the PPS fiber will be described in more detail.

The number of bending cuts and the number of bending wear cuts, which serve as a measure of the bending durability of the PPS fiber in the examples, were measured by the following method. 1. Measurement of the number of times of bending and cutting The load: 0.25 using a bending fatigue tester (manufactured by Toyo Seiki; MIT bending fatigue tester) according to JIS P-8115.
g / d, run-out frequency: 175 times / minute, run-out angle: about 270
Degrees (about 135 degrees each on the left and right), the curvature radius of the left and right bent surfaces in the bending piece sandwiching the fiber: 0.38 ≦ each
Under the condition of 0.03 mm, the number of reciprocating bendings before cutting each of ten fibers for the same sample was measured, and the average value was obtained. The larger the average value, the better the flex fatigue property. 2. Measurement of the number of times of bending wear cutting According to JIS L-1095-7.10.2B, a fixed φ3.0 mm friction element (hard steel wire (SWP-S
F)) The fiber contacted on the
Hang it under two free rollers (distance between rollers: 70 mm) provided diagonally below at a 5 degree angle, and apply a load of 0.2 g / d to one end of the fiber via another free roller. Set. Number of reciprocation of fiber sample: 105 times /
Minutes, reciprocating stroke: The frictional element was reciprocated under the condition of 25 mm, and the number of reciprocating bendings before cutting each of 10 monofilaments for the same sample was measured at room temperature to obtain an average value. The larger the average value, the better the bending wear resistance. 3. Measurement of Tensile Strength, Tensile Elongation, Hooking Strength Measured according to JIS L1013 under the conditions of a test length: 250 mm and a tensile speed: 300 mm / min. The hooking strength is
It is a value obtained by converting per decitex unit of the measurement sample. [Examples 1 to 4, Comparative Example 1] MFR was 70 g / 10 minutes,
100 g / 10 min, 140 g / 10 min, 180 g / 10
And 225 g / 10 min PPS pellets (manufactured by Toray Industries, Inc.) were dried at 135 ° C. for 8 hours under reduced pressure to prepare.

Each of the PPS pellets is φ40 mm (L
/ D = 25) continuously supplied to the single-axis extruder
The molten polymer melted at 0 ° C. was passed through a filtration layer in a spin pack through a gear pump, extruded into a fiber form from a spinneret for circular cross-section yarn, and cooled with hot water at 80 ° C.

Next, the cooling yarn was set to a gauge pressure of 4.9 kPa.
The primary stretching is performed 3.8 times in 4.1 seconds in a pressurized saturated steam atmosphere, and the secondary stretching is performed 1.2 times in hot air at 150 ° C., and then the conditions of 140 ° C. and 0.98 times are performed. To obtain a monofilament having a circular cross section with a diameter of 0.45 mm. Table 1 shows the test results of the strength and elongation of the obtained monofilament and the bending durability.

[0049]

[Table 1] As is clear from the results in Table 1, MFR 180 g / 10
The monofilaments (Examples 1 to 4) obtained from a PPS of less than or equal to 10 minutes have extremely excellent bending resistance with a flexural wear frequency of 7000 times or more and a flexural fatigue frequency of 150 times or more, as well as tensile strength and elongation and hooking. The strength was good. On the other hand, the monofilament obtained from the PPS having a high MFR (Comparative Example 1) had insufficient bending resistance. [Examples 2, 5 to 7, Comparative Examples 2 to 6] MFR of 100 g
135 minutes of PPS pellets (manufactured by Toray Industries, Inc.)
It dried and prepared under reduced pressure at 8 degreeC for 8 hours.

The PPS pellets were Φ40 mm (L / D
= 25) continuously supplied to a single-screw extruder at 330 ° C
The melted polymer was extruded into a fibrous form from a spinneret for circular cross-section yarn through a filter layer in a spin pack via a gear pump, and cooled with hot water at 80 ° C.

Next, the primary stretching atmosphere was set to a gauge pressure of 0.
98 kPa, 4.9 kPa, 49 kPa, 98 kPa,
Under the conditions of 4.17.6 kPa under each pressure-saturated steam atmosphere for 4.1 seconds, and hot water bath 100 ° C., polyethylene glycol bath 110 ° C., 140 ° C., and dry heat bath 105 ° C. for 4.1 seconds each. The first stage drawing was carried out 3.8 times each by passing through a cooling yarn through each drawing atmosphere.

Then, each of the primary stretched yarns is then
The film was stretched 1.2 times in hot air at 50 ° C.
By performing relaxation heat treatment at 0 ° C. and 0.98 times,
A monofilament having a circular cross section with a diameter of 0.45 mm was obtained. Table 2 shows the test results of the strength and elongation and bending durability of each of the obtained monofilaments.

[0053]

[Table 2] As is clear from the results in Table 2, PPS monofilaments in which the first stretching bath was stretched in one step under a pressurized saturated steam atmosphere having a gauge pressure of 0.98 kPa to 98 kPa (Examples 2 and 5)
Each of the samples Nos. To 7) had extremely excellent bending resistance in which the number of flex wear was 7000 times or more and the number of flex fatigue was 150 times or more, and also had good tensile strength and elongation and hooking strength. In contrast, the first stretching bath has a gauge pressure of 117.
In the case of a high pressure saturated steam atmosphere as high as 6 kPa (Comparative Example 2), or in the case where the first stretching bath was set in an atmosphere other than the pressurized saturated steam atmosphere (Comparative Examples 3 to 6), the spinning property was poor. The PPS fiber is inferior or has insufficient bending resistance, and the PPS fiber aimed at by the present invention cannot be obtained. [Examples 2 and 8 to 13 and Comparative Examples 7 and 8] The pressure-saturated steam residence time of the primary stretching in Example 2 was 0.05 seconds,
0.1 seconds, 0.5 seconds, 1.0 seconds, 4.1 seconds, 8.0 seconds,
Table 3 also shows the physical property evaluation results of the PPS monofilament obtained under the same conditions as in Example 2 except that the time was changed to 10.0 seconds, 20.0 seconds, and 40.0 seconds.

[0054]

[Table 3] As is apparent from the results in Table 3, the PPS monofilaments (Examples 8 to 13) obtained in the primary stretching under the pressurized saturated steam residence time of 0.1 second to 20 seconds have extremely excellent bending resistance. And the tensile strength and elongation and the hook strength are good. [Examples 2, 14 to 18] The physical property evaluation results of the PPS monofilament obtained in the same manner as in Example 2 except that the primary stretching ratio in Example 2 was changed to 3.0 times and 4.1 times, Table 4 also shows Examples 14 and 15.

Further, the evaluation results of the physical properties of the PPS monofilament obtained in the same manner as in Example 2 except that the secondary stretching temperature in Example 2 was changed to 120 ° C. The results of evaluating the physical properties of the PPS monofilament obtained in the same manner as in Example 2 except that the temperature was changed to 165 ° C. and 125 ° C. are also shown in Table 4 as Examples 17 and 18.

[0056]

[Table 4] [Comparative Examples 9 to 17] The results of evaluating the physical properties of PPS monofilaments obtained in the same manner as in Example 2 except that the primary stretching ratio in Example 2 was changed to 2.8 times and 5.0 times were compared with those in Comparative Example 9. , 10 are also shown in Table 5.

Further, the results of evaluation of the physical properties of PPS monofilaments obtained in the same manner as in Example 2 except that the secondary stretching temperature in Example 2 was changed to 103 ° C. and 180 ° C. were used as Comparative Examples 11 and 12, and The results of evaluating the physical properties of PPS monofilaments obtained in the same manner as in Example 2 except that the heat treatment temperature in Example 2 was changed to 190 ° C. and 102 ° C. are also shown in Table 5 as Comparative Examples 13 and 14.

Further, the results of evaluation of the physical properties of PPS monofilaments obtained in the same manner as in Example 2 except that the total draw ratio in Example 2 was changed to 3.8 times and 7.6 times were compared with Comparative Examples 15 and 16. Are also shown in Table 5.

Further, the results of evaluation of the physical properties of the PPS monofilament obtained in the same manner as in Example 2 except that the heat treatment magnification in Example 2 was changed to 0.68 are shown in Table 5 as Comparative Example 17.

[0060]

[Table 5] [Comparative Example 18] The heat treatment magnification in Example 2 was 1.02.
Comparative Example 18 was carried out in the same manner as in Example 2 except that
However, the obtained PPS monofilament did not have sufficient stretching strain, was crimped, and was not usable.

From the results in Tables 4 and 5, the primary stretching ratio was 3.0 to 4.1 times, and the total stretching ratio was 4.0 to 7.0.
It is important that the secondary stretching temperature is in the range of 110 ° C to 160 ° C, and then 110 ° C to 175 ° C.
It can be seen that by performing the relaxation heat treatment under the condition of 0.75 to 1.00 times, a PPS monofilament having extremely excellent bending resistance and excellent tensile strength and elongation and hooking strength can be obtained. [Example 19] As an example of an industrial fabric, the PPS monofilament obtained in Example 2 was used for weft and warp yarns.
A heavy-weave papermaking dryer canvas was created. When warp cracks in the dryer canvas were checked, no warp cracks were found. Comparative Example 19 For comparison, the PP obtained in Comparative Example 1 was used.
Using S monofilament for the weft and the warp, a double-woven paper dryer canvas was prepared. When the warp in the dryer canvas was checked for warp cracks, the warp crack at the ridge overlapping the weft was found on the canvas 100.
There were 19 places per m ² .

From the results of Example 19 and Comparative Example 19, it is understood that the dryer canvas using the PPS monofilament of the present invention has excellent bending durability.

[0063]

As described above, the PPS fiber represented by the monofilament of the present invention has not only excellent bending durability but also less resistance to cracking and abrasion when subjected to repeated bending, as well as tensile strength, tensile elongation and tensile strength. Since it has excellent mechanical properties such as hook strength, it has high industrial value as an industrial fabric such as a papermaking dryer canvas.

Further, according to the method for producing PPS fiber of the present invention, since a high temperature including the melting point of PPS or more is not required in the drawing or heat setting step, suitable conditions can be easily obtained and excellent productivity can be obtained. And PP with excellent bending durability
S fiber can be manufactured efficiently.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) D03D 1/00 D03D 1/00 Z 4L055 15/00 15/00 A D04H 17/10 D04H 17/10 D21F 7 / 08 D21F 7/08 A (72) Inventor Koji Tsubaki 1F Kawahara, Showa-cho, Okazaki-shi, Aichi F-term in Toray Monofilament Co., Ltd. 4D019 AA01 AA03 BA13 BB02 BC20 BD01 CB06 DA10 4L035 BB31 BB57 BB80 BB89 BB91 DD14 EE08 FF01 HH10 MF02 4L036 MA04 MA34 PA01 PA03 PA19 UA08 4L047 AA26 BA08 CB05 CC11 4L048 AA19 AA46 AA47 AA48 AA49 AB10 AC09 AC10 BA09 CA00 CA01 CA09 DA38 DA39 DA40 4L055 CF30 FA22

Claims (8)

[Claims] 1. A tensile strength measured according to JIS L1013 of 2.65 cN / dtex or more, a tensile elongation of 30% or more, and a tensile strength of 3.53 cN / d
dtex or more, and JIS L-1095-
The number of reciprocating wears before cutting in the bending wear test measured under the conditions described in the text according to the provisions of 7.10.2B is 7000 times or more, under the conditions described in the text according to the provisions of JIS P-8115 A polyphenylene sulfide fiber, wherein the number of reciprocating bendings before cutting in a bending fatigue test is 150 or more. 2. The method according to claim 1, wherein the number of reciprocating wears before cutting in the bending wear test is 8,500 or more, and the number of reciprocating bendings before cutting in the bending fatigue test is 200 or more. Polyphenylene sulfide fiber. 3. The polyphenylene sulfide fiber according to claim 1, wherein the melt flow rate is 180 g / 10 minutes or less and the polyphenylene sulfide fiber has a substantially linear molecular structure. 4. The diameter is from 0.050 mm to 4.00 mm.
It is a monofilament of Claim 1 characterized by the above-mentioned.
4. The polyphenylene sulfide fiber according to any one of 3. 5. A polyphenylene sulfide having a melt flow rate of 180 g / 10 min or less and having a substantially linear molecular structure is melt-extruded, and cooled in hot water at 70 ° C. or higher through an air layer or an inert gas layer. Subsequently, the obtained undrawn yarn is continuously subjected to a gauge pressure of 0.98 to 98 kPa.
Under a saturated steam atmosphere of 0.1 to 20.0 seconds in a range of 3.0 to 4.1 times,
After multi-stretching in an atmosphere of 160 ° C. in a range of 1.0 to 1.8 times so that the total stretching ratio becomes 4.0 to 7.0 times, then 0.1% in an atmosphere of 110 to 175 ° C. 75-
A method for producing polyphenylene sulfide fiber, wherein a relaxation heat treatment is performed in a 1.00-fold range. 6. The primary stretching is performed under a gauge pressure of 0.98-4.
The method for producing a polyphenylene sulfide fiber according to claim 5, wherein the method is performed in a saturated steam atmosphere of 9 kPa for 0.5 to 10.0 seconds. 7. An industrial woven fabric, wherein at least a part of the weft and / or warp constituting the woven fabric is made of the polyphenylene sulfide fiber according to any one of claims 1 to 4. 8. The industrial fabric according to claim 5, wherein the industrial fabric is a papermaking dryer canvas, a net conveyor for a thermal bonding nonwoven fabric heat bonding process, a dryer or a transport belt or a filter in a heat treatment machine. fabric.