Multifilament and braid

Abstract

It is provided that a multifilament and a braid that are capable of being processed into products in a wide range of temperature and are excellent in dimensional stability and abrasion resistance. A multifilament comprising 5 or more monofilaments, wherein the multifilament contains polyethylene having an intrinsic viscosity [] of 5.0 dL/g or more and 40.0 dL/g or less and substantially including ethylene as a repeating unit, and wherein a difference between a maximum value and a minimum value in a ratio of a diffraction peak intensity of orthorhombic crystal (200) plane to a diffraction peak intensity of orthorhombic crystal (110) plane in a monofilament cross section is 0.22 or less.

Claims

1. A multifilament comprising 5 or more monofilaments, wherein the multifilament contains polyethylene having an intrinsic viscosity [] of 5.0 dL/g or more and 40.0 dL/g or less and substantially including ethylene as a repeating unit, and wherein a difference between a maximum value and a minimum value in a ratio of a diffraction peak intensity of orthorhombic crystal (200) plane to a diffraction peak intensity of orthorhombic crystal (110) plane in a monofilament cross section is 0.22 or less.

2. The multifilament according to claim 1, wherein a coefficient of variation CV of the peak intensity ratio defined by Equation (1) below is 50% or less:
Coefficient of variation CV (%)=(standard deviation of the peak intensity ratio of the monofilaments)/(average value of the peak intensity of the monofilaments)100(1).

3. The multifilament according to claim 1, which has a difference between a maximum value of a degree of crystal orientation and a minimum value of a degree of crystal orientation of 0.010 or less in the mono filament cross section.

4. The multifilament according to claim 1, which shows, in accordance with JIS L 1095, 1000 times or more in number of reciprocating abrasions at break in an abrasion resistance test measured at a load of 5 cN/dtex and 100 times or more in number of reciprocating abrasions at break in an abrasion resistance test measured at a load of 10 cN/dtex.

5. The multifilament according to claim 1, wherein the monofilament has a titer of 3 dtex or more and 40 dtex or less.

6. The multifilament according to claim 1, which has a maximum thermal stress of 0.20 cN/dtex or more.

7. The multifilament according to claim 1, wherein a coefficient of variation CV of initial modulus defined by Equation (2) below is 30% or less:
Coefficient of variation CV(%)=(standard deviation of initial modulus of the monofilament)/(average value of initial moduli of the monofilaments)100(2)

8. The multifilament according to claim 1, which has a thermal stress of 0.15 cN/dtex or more at 120 C.

9. The multifilament according to claim 1, which has a thermal shrinkage of 0.20% or less at 70 C. and a thermal shrinkage of 3.0% or less at 120 C.

10. The multifilament according to claim 1, which has a tensile strength of 18 cN/dtex or more and an initial modulus of 600 cN/dtex or more.

11. A method for producing the multifilament according to claim 1, the method comprising: a dissolution step of dissolving the polyethylene in a solvent to obtain a polyethylene solution; a spinning step of discharging the polyethylene solution out of a nozzle at a temperature of melting point of the polyethylene or higher and cooling a discharged yarn thread with a coolant at 10 C. or higher and 60 C. or lower; a drawing step of drawing a discharged undrawn yarn while removing the solvent; and a winding step of winding a resulting yarn at 50 C. or lower and at a tensile force of 5 cN/dtex or less, wherein the drawing step includes 1 or more and 3 or less in number of drawing step, a draw ratio is 7.0 times or more and 60 times or less, and a total drawing time is 0.5 minutes or longer and 20 minutes or shorter.

12. A braid comprising a multifilament comprising 5 or more mono filaments, wherein the multifilament contains polyethylene having an intrinsic viscosity [] of 5.0 dL/g or more and 40.0 dL/g or less and substantially including ethylene as a repeating unit, and wherein in the multifilament in a state where the braid is unbraided, a difference between a maximum value and a minimum value in a ratio of a di inaction peak intensity of orthorhombic crystal (200) plane to a diffraction peak intensity of orthorhombic crystal (110) plane in a monofilament cross section is 0.18 or less.

13. The braid according to claim 12, wherein a coefficient of variation CV of the peak intensity ratio defined by Equation (1) below is 40% or less:
Coefficient of variation CV (%)=(standard deviation of the peak intensity ratio of the monofilament)/(average value of the peak intensity of the monofilament)100(1)

14. The braid according to claim 12, which has a difference between a maximum value of a degree of crystal orientation and a minimum value of a degree of crystal orientation of 0.012 or less.

15. The braid according to claim 12, which shows 1000 times or more in number of reciprocating abrasions at break in an abrasion resistance test measured at a load of 5 cN/dtex in accordance with JIS L-1095.

16. The braid according to claim 12, wherein in the abrasion resistance test measured at a load of 5 cN/dtex, a difference between a number of reciprocating abrasions of the braid and a number of reciprocating abrasions of the multifilament in a state where the braid is upbraided is 320 times or less.

17. The braid according to claim 12, wherein the multifilament in the state where the braid is unbraided shows 100 times or more in number of reciprocating abrasions at break in an abrasion resistance test measured at a load of 10 cN/dtex in accordance with JIS L-1095.

18. The braid according to claim 12, wherein a difference between a tensile strength of the braid and a tensile strength of the multifilament in the state where the braid is unbraided is 5 cN/dtex or less.

19. The braid according to claim 12, which has a thermal shrinkage of 3.0% or less at 120 C.

20. The braid according to claim 12, which has a tensile strength of 18 cN/dtex or more and an initial modulus of 300 cN/dtex or more.

21. The braid according to claim 12, wherein the monofilament has a titer of 2 dtex or more and 40 dtex or less in the state that the braid is unbraided.

22. The braid according to claim 12, wherein the multifilament in the state that the braid is unbraided has a thermal shrinkage of 0.11% or less at 70 C. and a thermal shrinkage of 2.15% or less at 120 C.

23. The braid according to claim 12, wherein the multifilament in the state that the braid is unbraided has a thermal stress of 0.15 cN/dtex or more at 120 C.

24. A method for producing the braid according to claim 12, the method comprising a step of: braiding the multifilament and performing heat treatment, wherein the heat treatment is performed at 70 C. or higher; a time of the heat treatment is 0.1 seconds or longer and 30 minutes or shorter; and a tensile force of 0.02 cN/dtex or more and 15 cN/dtex or less is applied to the braid in the heat treatment.

25. The method for producing the braid according to claim 24, wherein a length of the braid after the heat treatment is 1.05 times or more and 15 times or less as long as a length of the braid before the heat treatment by the tensile force.

26. A fishing line obtained from the braid according to claim 12.

27. A net obtained from the braid according to claim 12.

28. A rope obtained from the braid according to claim 12.

Description

EXAMPLES

(1) Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples. The present invention can also be carried out by appropriate modifications in a range that can fall within the foregoing and following gists, and all such appropriate modifications are encompassed in the technical scope of the present invention.

(2) The characteristic values of the multifilaments as well as the multifilaments each in a state that the braid is unbraided in the following respective examples and comparative examples were measured as follows. The tensile strength, elongation at break, initial modulus, thermal shrinkage at 120 C., and abrasion test in the case of a load of 5 cN/dtex of the braids in the following respective examples and comparative examples were measured in the same manner as in the case of the multifilaments or the like.

(3) (1) Intrinsic Viscosity

(4) Decalin at a temperature of 135 C. as a solvent was used to obtain various diluted solutions, and specific viscosities of the diluted solutions were measured by Ubbelohde capillary viscometer. An intrinsic viscosity was determined based on extrapolated points to an originating point of a straight line obtained by least squares approximation of the viscosities plotted against concentrations. When the measurement was performed, a sample was divided or cut into portions each having a length of about 5 mm, and 1 mass % of an antioxidant (YOSHINOX (registered trade name) BHT, manufactured by API Corporation) relative to the sample was added, and stirred and dissolved at 135 C. for 4 hours to prepare measurement solutions.

(5) (2) Weight Average Molecular Weight

(6) A weight average molecular weight was calculated, according to the following equation, from the value of the intrinsic viscosity measured in (1) above.
Weight average molecular weight=5.36510.sup.4(intrinsic viscosity).sup.1.37
(3) Peak Intensity Ratio in Interior of Monofilament

(7) A crystal size and orientation evaluation were measured by x-ray diffraction method. The World's Largest Synchrotron Radiation Facility SPring-8 was used as an x-ray source, and a BL03 hatch was used. The x-ray used has a wavelength of 1.0 . A size of the x-ray was adjusted so as to set the distance between the farthest 2 points existing on the outer circumference of the cross section of the x-ray to 7 m or less. Each sample was set on an XYZ stage such that the monofilament axis was perpendicular to the stage, and the sample was irradiated with the x-ray such that the x-ray was irradiated perpendicularly to the axal direction of the sample. The stage was moved slightly so as to set the middle point of the distance between the farthest 2 points existing on the outer circumference of the cross section of the x-ray to the center of the stage. The x-ray intensity is extremely high, so that if the exposure time of the sample is too long, the sample would be damaged. The exposure time during the x-ray diffraction measurement was therefore set to be within 30 seconds. Under the measurement conditions, x-ray diffraction chart was measured for the respective points by irradiating beam at a substantially even interval from the center part of each monofilament to the outer circumferential periphery of the monofilament. Specifically, x-ray diffraction chart was measured from the center of the diameter of each monofilament to the outer circumferential periphery of the monofilament at 2.5 m intervals such that the center of the monofilament, points of 2.5 m, 5.0 m, 7.5 m, and so on from the center of the monofilament. For example, in the case of a monofilament with a diameter of 32 m (radius of 16 m), the x-ray diffraction chart was measured at 7 points in total: that is, the center, a point of 2.5 m, a point of 5.0 m, a point of 7.5 m, a point of 10.0 m, a point of 12.5 m, and a point of 15.0 m from the center of the monofilament. The x-ray diffraction chart was recorded by using a flat panel installed in a place 67 mm apart from the sample. A peak intensity ratio was calculated from the peak intensity values of the orthorhombic crystal (110) and the orthorhombic crystal (200) in the diffraction profile in the equator direction based on the recorded image data.

(8) (4) Degree of Crystal Orientation in Interior of Monofilament

(9) A measurement was carried out in the same manner as in (3) above using the World's Largest Synchrotron Radiation Facility SPring-8 as an x-ray source. The degree of crystal orientation was calculated, according to the following equation, from the half width of the orientation distribution function of the orthorhombic crystal (110) in the diffraction profile in the azimuth angle direction.
Degree of crystal orientation=(180(half width of orthorhombic crystal (110) plane))/180

(10) Specifically, for the degree of crystal orientation, a measurement was carried out from the center of the diameter of each monofilament to the outer circumferential periphery of the monofilament at 2.5 m intervals such that the center of the monofilament, points of 2.5 m, 5.0 m, 7.5 m, and so on from the center of the monofilament. For example, in the case of a monofilament with a diameter of 32 m (radius of 16 m), the measurement was carried out at 7 points in total: that is, the center, a point of 2.5 m, a point of 5.0 m, a point of 7.5 m, a point of 10.0 m, a point of 12.5 m, and a point of 15.0 m from the center of the monofilament.

(11) (5) Tensile Strength, Elongation at Break, and Initial Modulus

(12) Measurements were carried out in accordance with JIS L 1013 8.5.1, and a strain-stress curve was obtained under conditions that a length of a sample was 200 mm (a length between chucks), and an elongation speed was 100 mm/min, an ambient temperature was 20 C., and a relative humidity was 65%, by using a TENSILON Universal Material Testing Instrument RTF-1310 manufactured by ORIENTEC Co., LTD. A tensile strength and an elongation at break were calculated from a stress and an elongation at breaking point, and an initial modulus was calculated from the tangential line providing a maximum gradient on the curve in the vicinity of the originating point. At this time, an initial load applied to the sample at the measurement was one tenth of the mass (g) per 10000 m of the sample. An average of values obtained in ten measurements was used for each case.

(13) (6) Coefficient of Variation CV

(14) An initial modulus of each monofilament constituting the sample was measured by the above-mentioned measurement method, and a value of ((standard deviation of initial modulus of monofilament constituting multifilament)/(average value of initial moduli of monofilament constituting multifilament)100 was calculated and defined as the coefficient of variation CV (%).

(15) (7) Thermal Shrinkage

(16) Samples were each cut into a size of 70 cm, and positions distant from both ends, respectively, by 10 cm, were marked so as to show that a length of each sample was 50 cm. Next, the samples were hung on a zig so as to prevent a load from being applied thereto, and the samples in this hanging state were heated at a temperature of 70 C. in a hot air circulating type heating furnace for 30 minutes. Thereafter, the samples were taken out of the heating furnace, and gradually cooled down sufficiently to room temperature. Thereafter, a length between the positions which had been marked on each sample at the beginning, was measured. The thermal shrinking percentage can be obtained by using the following equation. The average value of measurement values in two times of the thermal shrinkage was employed.
Thermal shrinkage percentage (%)=100(length of sample before heatinglength of sample after heating)/(length of sample before heating)

(17) Further, the thermal shrinkage at 120 C. was also measured in the same manner as described above except that the temperature of heating for 30 minutes was changed from 70 C. to 120 C.

(18) (8) Thermal Stress

(19) A thermal stress stain measurement apparatus (TMA/SS120C manufactured by Seiko Instruments Inc.) was used for the measurement. Each sample was prepared so as to have a length of 20 mm, an initial load of 0.01764 cN/dtex was applied to the sample, and a temperature was increased from room temperature (20 C.) to the melting point at a temperature rising speed of 20 C./minute to measure thermal stress at 120 C. The thermal stress at which the thermal shrinkage became the maximum and the temperature at that time were measured.

(20) (9) Titer

(21) Each sample was cut at 5 points of different positions to give monofilaments each having a length of 20 cm, and the weights thereof were measured, and an average value of the weights was converted into a value for 10000 m to obtain titer (dtex).

(22) (10) Abrasion Test

(23) The abrasion resistance was evaluated by an abrasion test in accordance with the B-method for measuring abrasion strength among general spun yarn testing methods (JIS L 1095). The measurement was carried out using a yarn holding tester, manufactured by ASANO MACHINE MFG CO., LTD. Using hard steel with 2.0 mm as a friction block, the test was carried out at a load of 5 cN/dtex or 10 cN/dtex, an ambient temperature of 20 C., a friction speed of 115 times/minute, a reciprocating distance of 2.5 cm, and a friction angle of 110 to measure the number of friction times until the sample was broken. The number of reciprocating friction times at break of each sample by abrasion was measured respectively when the load was set to 5 cN/dtex and when the load was set to 10 cN/dtex. The number of testing times was 7, and the data of the maximum number of times and of the minimum number of times was removed, and the average value of the remaining 5 measurement values was employed. The abrasion test of each multifilament was carried out by using a sample adjusted to have a titer of about 220 dtex.

Example 1-1

(24) A dispersion containing ultra high molecular weight polyethylene having an intrinsic viscosity of 18.0 dL/g, a weight average molecular weight of 2900000 and a melting peak of 134 C. and decalin was adjusted so as to have a polyethylene concentration of 11.0 mass %. This dispersion was converted into a solution by adjusting a retention time in a temperature range of 205 C. to 8 minutes by an extruder, and the polyethylene solution was discharged out of a spinneret at a throughput discharge amount of 4.5 g/minute and a spinneret surface temperature of 180 C. The number of orifices formed in the spinneret was 15, and the orifice diameter was 1.0 mm. The fine pores for discharging yarns (one end part of the orifice) formed in the surface of the spinneret were shielded so as to be kept from direct contact with the outside air. Specifically, the spinneret was shielded from the outside air by a shielding plate made of 10 mm-thick heat insulating glass. The distance between the shielding plate and the fine pore nearest to the shielding plate was set to 40 mm, and the distance between the shielding plate and the fine pore farthest from the shielding plate was set to 60 mm. A difference between the highest temperature in the fine pore and the lowest temperature in the fine pore was 3 C., and the coefficient of variation CV of the discharge amount in each fine pore ((standard deviation of discharge amount of 15 fine pores)/(average value of discharge amount of 15 fine pores)100) was 8%. The discharge yarn thread was cooled in a water-cooling bath at 20 C., while being taken, and thereafter the yarn thread was taken at a speed of 70 m/minute to obtain an undrawn multifilament comprising 15 monofilaments. Next, the above-mentioned undrawn multifilament was drawn 4.0 times while being heated and dried by hot air at 120 C. Successively, the multifilament was drawn 2.7 times by hot air at 150 C., and in the drawn state, the drawn multifilament was immediately wound up. The total draw ratio was set to 10.8 times, the total drawing time was set to 4 minutes, and the deformation rate during the drawing was set to 0.0300 sec.sup.1. The temperature during winding up of the drawn multifilament was set to 30 C., and the tension during winding up was set to 0.100 cN/dtex. The retention time between after drawing process at 150 C. and before winding process was 2 minutes. The multifilament production conditions are shown in Table 1, and the physical properties and evaluation results of the obtained multifilament are shown in Table 2.

Example 1-2

(25) A multifilament was obtained in the same manner as in Example 1-1, except that the throughput discharge amount of the polyethylene solution was set to 5.0 g/minute; the distance between the shielding plate and the fine pore farthest from the shielding plate was set to 80 mm; the difference between the highest temperature in the fine pore and the lowest temperature in the fine pore was set to 4 C.; the coefficient of variation CV of the discharge amount in each fine pore was set to 11%; the spinning speed was set to 60 m/minute; the draw ratio by hot air at 150 C. was set to 2.5 times (total draw ratio to 10.0 times); the total drawing time was set to 6 minutes; and the deformation rate during the drawing was set to 0.0200 sec*.sup.1 in Example 1-1. The multifilament production conditions are shown in Table 1, and the physical properties and evaluation results of the obtained multifilament are shown in Table 2.

Example 1-3

(26) A multifilament was obtained in the same manner as in Example 1-1, except that the distance between the shielding plate and the fine pore farthest from the shielding plate was set to 45 mm; the difference between the highest temperature in the fine pore and the lowest temperature in the fine pore was set to 2 C.; the coefficient of variation CV of the discharge amount in each fine pore was set to 6%; the total drawing time was set to 12 minutes; the deformation rate during the drawing was set to 0.0100 sec.sup.1; the tension during winding up was set to 0.200 cN/dtex; and the retention time between after drawing process and before winding process was set to 1 minute in Example 1-1. The multifilament production conditions are shown in Table 1, and the physical properties and evaluation results of the obtained multifilament are shown in Table 2.

Example 1-4

(27) A multifilament was obtained in the same manner as in Example 1-1, except that the retention time in the temperature range of 205 C. was set to 11 minutes; the draw ratio by hot air at 150 C. was set to 2.5 times (total draw ratio was set to 10.0 times); the total drawing time was set to 5 minutes; the deformation rate during the drawing was set to 0.0240 sec.sup.1; the temperature during winding up of the drawn yarn was set to 40 C.; the tension during winding up was set to 0.030 cN/dtex; and the retention time between after drawing process and before winding process was set to 5 minutes in Example 1-1. The multifilament production conditions are shown in Table 1, and the physical properties and evaluation results of the obtained multifilament are shown in Table 2.

Example 1-5

(28) A multifilament was obtained in the same manner as in Example 1-1, except that the retention time in the temperature range of 205 C. was set to 18 minutes; the draw ratio by hot air at 120 C. was set to 4.5 times; the draw ratio by hot air at 150 C. was set to 2.2 times (total draw ratio was set to 9.9 times); the total drawing time was set to 5 minutes; and the deformation rate during the drawing was set to 0.0240 sec.sup.1 in Example 1-1. The multifilament production conditions are shown in Table 1, and the physical properties and evaluation results of the obtained multifilament are shown in Table 2.

Comparative Example 1-1

(29) A multifilament was obtained in the same manner as in Example 1-1, except that the retention time in the temperature range of 205 C. was set to 32 minutes; the throughput discharge amount was set to 1.0 g/minute; the shielding plate made of 10 mm-thick insulating glass was not installed; the difference between the highest temperature in the fine pore and the lowest temperature in the fine pore was set to 12 C.; the coefficient of variation CV of the discharge amount in each fine pore was set to 23%; the draw ratio by hot air at 120 C. was set to 3.0 times; and the draw ratio by hot air at 150 C. was set to 2.3 times (total draw ratio was set to 6.9 times) in Example 1-1. The multifilament production conditions are shown in Table 1 and the physical properties and evaluation results of the obtained multifilament are shown in Table 2.

Comparative Example 1-2

(30) A multifilament was obtained in the same manner as in Example 1-1, except that the discharged yarn thread was cooled in a cooling water bath at 65 C. and the undrawn yarn was obtained under the condition of spinning speed of 10 m/minute in Example 1-1. The multifilament production conditions are shown in Table 1 and the physical properties and evaluation results of the obtained multifilament are shown in Table 2.

Comparative Example 1-3

(31) A multifilament was obtained in the same manner as in Example 1-1, except that the total drawing time was set to 25 minutes and the deformation rate during drawing was set to 0.0005 sec.sup.1 in Example 1-1. The multifilament production conditions are shown in Table 1 and the physical properties and evaluation results of the obtained multifilament are shown in Table 2.

Comparative Example 1-4

(32) A multifilament was obtained in the same manner as in Example 1-1, except that the draw ratio by hot air at 120 C. was set to 3.5 times; the draw ratio by hot air at 150 C. was set to 2.0 times (total draw ratio was set to 7.0 times); the temperature during winding up of the drawn yarn was set to 70 C.; and the tension during winding up was set to 0.008 cN/dtex in Example 1-1. The multifilament production conditions are shown in Table 1 and the physical properties and evaluation results of the obtained multifilament are shown in Table 2.

Comparative Example 1-5

(33) In the same manner as in the production method described in Japanese Patent No. 4141686 (Patent Document 3), a slurry-like mixture containing 10 mass % ultra high molecular weight polyethylene having an intrinsic viscosity of 21.0 dL/g, a weight average molecular weight of 3500000 and a melting peak of 135 C. and 90 mass % decalin was supplied to a screw-type kneader. This was converted into a solution by adjusting a retention time in a temperature range of 230 C. to 11 minutes, and the polyethylene solution was discharged out of a spinneret at a throughput discharge amount of 1.4 g/minute and a spinneret surface temperature of 170 C. The number of orifices formed in the spinneret was 96, and the orifice diameter was 0.7 mm. A difference between the highest temperature in the fine pore and the lowest temperature in the fine pore was 12 C., and the coefficient of variation CV of the discharge amount in each fine pore ((standard deviation of discharge amount of 96 fine pores)/(average value of discharge amount of 96 fine pores)100) was 24%. Nitrogen gas at 100 C. was blown as evenly as possible at an average wind velocity of 1.2 m/second to the discharged yarn thread from slit-like orifices for gas supply disposed immediately under a spinneret to positively evaporate decalin from the fiber surface. Immediately thereafter, the discharged yarn thread was cooled with an air current set at 30 C. while being taken. Thereafter, the resulting yarn thread was taken at a speed of 75 m/minute by a Nelson-like roller installed downstream of the spinneret to obtain an undrawn multifilament comprising 96 monofilaments. At this time, the weight of the solvent contained in the yarn thread was decreased to be about half of the weight of the solvent contained in the yarn thread at the time of being discharged out of the spinneret. Next, the above-mentioned undrawn multifilament was drawn 4.0 times while being heated and dried by hot air at 100 C. in a heating oven. Successively; the multifilament was drawn 4.0 times by hot air at 149 C. in the heating oven, and in the drawn state, the drawn multifilament was immediately wound up. The total draw ratio was set to 16.0 times, the total drawing time was set to 8 minutes, and the deformation rate during the drawing was set to 0.0200 sec.sup.1. The temperature during winding up of the drawn multifilament was set to 30 C. and the tension during winding up was set to 0.100 cN/dtex. The retention time between after drawing process at 149 C. and before winding process was 2 minutes. The multifilament production conditions are shown in Table 1 and the physical properties and evaluation results of the obtained multifilament are shown in Table 2.

Comparative Example 1-6

(34) A dispersion containing ultra high molecular weight polyethylene having an intrinsic viscosity of 11.0 dL/g, a weight average molecular weight of 1400000, and a melting peak of 131 C. and liquid paraffin was adjusted so as to have a polyethylene concentration of 14.0 mass %. This dispersion was converted into a solution by adjusting a retention time in a temperature range of 220 C. to 39 minutes by an extruder, and the polyethylene solution was discharged out of a spinneret at a throughput discharge amount of 2.0 g/minute and a spinneret surface temperature of 170 C. The number of orifices formed in the spinneret was 48, and the orifice diameter was 1.0 mm. A difference between the highest temperature in the fine pore and the lowest temperature in the fine pore was 13 C., and the coefficient of variation CV of the discharge amount in each fine pore ((standard deviation of discharge amount of 48 fine pores)/(average value of discharge amount of 48 fine pores)100) was 22%. The discharge yarn thread was cooled in a water-cooling bath at 20 C., while being taken, and thereafter the yarn thread was taken at a speed of 35 m/minute to obtain an undrawn multifilament comprising 48 monofilaments. Next, the above-mentioned undrawn multifilament was allowed to pass through n-decane at 80 C. to remove the liquid paraffin. Next, the above-mentioned undrawn multifilament was drawn 6.0 times while being heated and dried by hot air at 120 C. Successively, the multifilament was drawn 3.0 times by hot air at 150 C., and in the drawn state, the drawn multifilament was immediately wound up. The total draw ratio was set to 18.0 times, the total drawing time was set to 9 minutes, and the deformation rate during the drawing was set to 0.0400 sec.sup.1. The temperature during winding up of the drawn multifilament was set to 30 C., and the tension during winding up was set to 0.100 cN/dtex. The retention time between after drawing process at 150 C. and before winding process was 2 minutes. The multifilament production conditions are shown in Table 1 and the physical properties and evaluation results of the obtained multifilament are shown in Table 2.

Comparative Example 1-7

(35) A multifilament was obtained in the same manner as in Example 1-1, except that the retention time in the temperature range of 205 C. was set to 25 minutes; the throughput discharge amount was set to 1.3 g/minute: the shielding plate made of 10 mm-thick insulating glass was not installed; the difference between the highest temperature in the fine pore and the lowest temperature in the fine pore was set to 10 C.; the coefficient of variation CV of the discharge amount in each fine pore was set to 14%; the draw ratio by hot air at 120 C. was set to 3.0 times; and the draw ratio by hot air at 150 C. was set to 2.3 times (total draw ratio was set to 6.9 times) in Example 1-1. The multifilament production conditions are shown in Table 1 and the physical properties and evaluation results of the obtained multifilament are shown in Table 2.

(36) TABLE-US-00001 TABLE 1 Example Example Example Example unit 1-1 1-2 1-3 1-4 Raw Intrinsic viscosity [dL/g] 18.0 18.0 18.0 18.0 material Weight average molecular weight [g/mol] 2,900,000 2,900,000 2,900,000 2,900,000 Production Dissolution Kind of solvent decalin decalin decalin decalin method step Concentration of the polyethylene [mass %] 11.0 11.0 11.0 11.0 Retention time during temperature range of [min] 8 8 8 11 more than 200 C. by an extruder Spinning Spinneret temperature [ C.] 180 180 180 180 step Throughput at an orifice [g/min] 4.5 5.0 4.5 4.5 Maximum value of temperature difference [ C.] 3 4 2 3 among the fine pores Coefficient of variation of the discharge [%] 8 11 6 8 amount in each fine pore Number of pores [piece] 15 15 15 15 Orifice diameter [mm] 1.0 1.0 1.0 1.0 Quenching temperature [ C.] 20 20 20 20 Spinning speed [m/min] 70 60 70 70 Drawing Number of drawing step [times] 2 2 2 2 step Draw ratio [times] 10.8 10.0 10.8 10.0 Drawing time [min] 4.0 6.0 12.0 5.0 Deformation rate during drawing [sec.sup.1] 0.0300 0.0200 0.0100 0.0240 Winding Retention time between after drawing [min] 2 2 1 6 step process and before winding process Temperature during winding up [ C.] 30 30 30 40 Tension during winding up [cN/dtex] 0.100 0.100 0.200 0.030 Comparative Comparative Comparative Example Example Example Example unit 1-5 1-1 1-2 1-3 Raw Intrinsic viscosity [dL/g] 18.0 18.0 18.0 18.0 material Weight average molecular weight [g/mol] 2,900,000 2,900,000 2,900,000 2,900,000 Production Dissolution Kind of solvent decalin decalin decalin decalin method step Concentration of the polyethylene [mass %] 11.0 11.0 11.0 11.0 Retention time during temperature range of [min] 18 32 8 8 more than 200 C. by an extruder Spinning Spinneret temperature [ C.] 180 180 180 180 step Throughput at an orifice [g/min] 4.5 1.0 4.5 4.5 Maximum value of temperature difference [ C.] 3 12 3 3 among the fine pores Coefficient of variation of the discharge [%] 8 23 8 8 amount in each fine pore Number of pores [piece] 15 15 15 15 Orifice diameter [mm] 1.0 1.0 1.0 1.0 Quenching temperature [ C.] 20 20 65 20 Spinning speed [m/min] 70 70 10 70 Drawing Number of drawing step [times] 2 2 2 2 step Draw ratio [times] 9.9 6.9 10.8 10.8 Drawing time [min] 5.0 4.0 4.0 25.0 Deformation rate during drawing [sec.sup.1] 0.0240 0.0300 0.0300 0.0005 Winding Retention time between after drawing [min] 2 2 2 2 step process and before winding process Temperature during winding up [ C.] 30 30 30 30 Tension during winding up [cN/dtex] 0.100 0.100 0.100 0.100 Comparative Comparative Comparative Comparative Example Example Example Example unit 1-4 1-5 1-6 1-7 Raw Intrinsic viscosity [dL/g] 18.0 21.0 11.0 18.0 material Weight average molecular weight [g/mol] 2,900,000 3,500,000 1,400,000 2,900,000 Production Dissolution Kind of solvent decalin decalin liquid decalin method step paraffin Concentration of the polyethylene [mass %] 11.0 10.0 14.0 11.0 Retention time during temperature range of [min] 8 11 39 25 more than 200 C. by an extruder Spinning Spinneret temperature [ C.] 180 170 170 180 step Throughput at an orifice [g/min] 4.5 1.4 2.0 1.3 Maximum value of temperature difference [ C.] 3 12 13 10 among the fine pores Coefficient of variation of the discharge [%] 8 24 22 14 amount in each fine pore Number of pores [piece] 15 96 48 15 Orifice diameter [mm] 1.0 0.7 1.0 1.0 Quenching temperature [ C.] 20 30 20 20 Spinning speed [m/min] 70 73 35 70 Drawing Number of drawing step [times] 2 2 2 2 step Draw ratio [times] 7.0 16.0 18.0 6.9 Drawing time [min] 4.0 8.0 9.0 4.0 Deformation rate during drawing [sec.sup.1] 0.0300 0.0200 0.0400 0.0300 Winding Retention time between after drawing [min] 2 2 2 2 step process and before winding process Temperature during winding up [ C.] 70 30 30 30 Tension during winding up [cN/dtex] 0.008 0.100 0.100 0.100

(37) TABLE-US-00002 TABLE 2 Example Example Example Example Example unit 1-1 1-2 1-3 1-4 1-5 Structure Maximum value of the peak intensity ratio [] 0.33 0.31 0.38 0.32 0.30 Minimum value of the peak intensity ratio [] 0.25 0.21 0.31 0.18 0.15 Difference between the maximum value of the peak [] 0.08 0.10 0.07 0.14 0.15 intensity ratio and the minimum value of the peak intensity radio Coefficient of variation of the peak intensity ratio [%] 5 16 4 23 28 Maximum value of the degree of crystal orientation [] 0.986 0.978 0.993 0.980 0.978 Minimum value of the degree of crystal orientation [] 0.980 0.973 0.988 0.975 0.972 Difference between the maximum value of the degree [] 0.006 0.005 0.005 0.005 0.006 of crystal orientation and the minimum value of the degree of crystal orientation Physical Titer of monofilaments [dtex] 6.5 9.2 6.5 7.1 7.1 properties Diameter of monofilaments [m] 31.7 37.5 31.7 33.0 33.0 Number of monofilament [number] 15 15 15 15 15 Tensile strength [cN/dtex] 25 22 26 21 21 Elongation at break [%] 4.1 4.3 4.1 4.2 4.3 Initial modulus [cN/dtex] 590 680 920 710 680 Coefficient of variation of elastic modulus of the [%] 14 12 6 15 16 multifilament Maximum thermal stress [cN/dtex] 0.43 0.31 0.46 0.38 0.30 Temperature at maximum thermal stress [ C.] 141 138 140 141 141 Thermal stress at 120 C. [cN/dtex] 0.23 0.17 0.23 0.19 0.17 Thermal shrinkage at 70 C. [%] 0.08 0.11 0.10 0.14 0.14 Thermal shrinkage at 120 C. [%] 1.9 2.2 2.0 2.6 2.6 Number of reciprocating abrasions at break at a load [times] 3052 4068 3260 2841 2713 of 5 cN/dtex Number of reciprocating abrasions at break at a load [times] 288 346 309 211 193 of 10 cN/dtex Comparative Comparative Comparative Comparative Example Example Example Example unit 1-1 1-2 1-3 1-4 Structure Maximum value of the peak intensity ratio [] 0.31 0.43 0.36 0.30 Minimum value of the peak intensity ratio [] 0.07 0.03 0.04 0.07 Difference between the maximum value of the peak [] 0.24 0.40 0.32 0.23 intensity ratio and the minimum value of the peak intensity radio Coefficient of variation of the peak intensity ratio [%] 51 64 61 52 Maximum value of the degree of crystal orientation [] 0.969 0.954 0.959 0.965 Minimum value of the degree of crystal orientation [] 0.954 0.942 0.944 0.953 Difference between the maximum value of the degree [] 0.015 0.012 0.015 0.012 of crystal orientation and the minimum value of the degree of crystal orientation Physical Titer of monofilaments [dtex] 2.5 45.8 6.5 10.1 properties Diameter of monofilaments [m] 26.0 33.9 31.7 39.4 Number of monofilament [number] 15 15 15 15 Tensile strength [cN/dtex] 17 8 12 17 Elongation at break [%] 4.3 6.5 6.1 5.1 Initial modulus [cN/dtex] 530 211 440 490 Coefficient of variation of elastic modulus of the [%] 38 16 28 33 multifilament Maximum thermal stress [cN/dtex] 0.18 0.13 0.16 0.17 Temperature at maximum thermal stress [ C.] 140 139 139 141 Thermal stress at 120 C. [cN/dtex] 0.13 0.10 0.14 0.14 Thermal shrinkage at 70 C. [%] 0.08 0.23 0.22 0.21 Thermal shrinkage at 120 C. [%] 1.9 3.3 3.1 3.1 Number of reciprocating abrasions at break at a load [times] 920 125 201 896 of 5 cN/dtex Number of reciprocating abrasions at break at a load [times] 58 breakage 11 89 of 10 cN/dtex just after measurement Comparative Comparative Comparative Example Example Example unit 1-5 1-6 1-7 Structure Maximum value of the peak intensity ratio [] 0.35 0.51 3.1 Minimum value of the peak intensity ratio [] 0.12 0.20 28.0 Difference between the maximum value of the peak [] 0.23 0.31 15 intensity ratio and the minimum value of the peak intensity radio Coefficient of variation of the peak intensity ratio [%] 51 58 18 Maximum value of the degree of crystal orientation [] 0.981 0.969 4.4 Minimum value of the degree of crystal orientation [] 0.936 0.950 510 Difference between the maximum value of the degree [] 0.045 0.019 31 of crystal orientation and the minimum value of the degree of crystal orientation Physical Titer of monofilaments [dtex] 1.2 4.9 0.17 properties Diameter of monofilaments [m] 12.3 28.0 140 Number of monofilament [number] 96 48 0.12 Tensile strength [cN/dtex] 38 25 0.09 Elongation at break [%] 3.9 3.3 2.0 Initial modulus [cN/dtex] 1521 780 895 Coefficient of variation of elastic modulus of the [%] 31 39 52 multifilament Maximum thermal stress [cN/dtex] 40.00 0.34 0.32 Temperature at maximum thermal stress [ C.] 130 140 0.08 Thermal stress at 120 C. [cN/dtex] 0.13 0.14 0.24 Thermal shrinkage at 70 C. [%] 0.23 0.23 50 Thermal shrinkage at 120 C. [%] 3.1 3.4 0.959 Number of reciprocating abrasions at break at a load [times] 320 913 0.941 of 5 cN/dtex Number of reciprocating abrasions at break at a load [times] 29 88 0.018 of 10 cN/dtex

Example 2-1

(38) A braid was produced by braiding 4 multifilaments of Example 1-1 such that a braiding angle was adjusted to 20. The braid was subjected to heat treatment by heating in a hot air heating furnace set at 151 C. A time for the heat treatment was set to 1.5 minutes, a tension applied to the braid during the heat treatment was set to 1.6 cN/dtex, and a re-draw ratio was set to 2.00 times. The braid production conditions, the physical properties and evaluation results of the braid obtained, and the physical properties of the multifilament in a state that the braid is unbraided are shown in Table 3.

Example 2-2

(39) A multifilament was obtained in the same manner as in Example 2-1, except that the tension during the heat treatment was set to 2.4 cN/dtex and the re-draw ratio was set to 3.00 times in Example 2-1. The braid production conditions, the physical properties and evaluation results of the braid obtained, and the physical properties of the multifilament in a state that the braid is unbraided are shown in Table 3.

Example 2-3

(40) A multifilament was obtained in the same manner as in Example 2-1, except that the heat treatment temperature was set to 152 C., the heat treatment time was set to 2.0 minutes, the tension during the heat treatment was set to 3.8 cN/dtex, and the re-draw ratio was set to 4.00 times in Example 2-1. The braid production conditions, the physical properties and evaluation results of the braid obtained, and the physical properties of the multifilament in a state that the braid is unbraided are shown in Table 3.

Example 2-4

(41) A braid was produced by braiding 4 multifilaments of Example 1-2 such that a braiding angle was adjusted to 20. The braid was subjected to heat treatment by heating in a hot air heating furnace set at 151 C. A time for the heat treatment was set to 1.0 minute, a tension applied to the braid during the heat treatment was set to 1.4 cN/dtex, and a re-draw ratio was set to 1.80 times. The braid production conditions, the physical properties and evaluation results of the braid obtained, and the physical properties of the multifilament in a state that the braid is unbraided are shown in Table 3.

Example 2-5

(42) A multifilament was obtained in the same manner as in Example 2-4, except that the heat treatment time was set to 2.0 minutes, the tension during the heat treatment was set to 2.7 cN/dtex, and the re-draw ratio was set to 3.50 times in Example 2-4. The braid production conditions, the physical properties and evaluation results of the braid obtained, and the physical properties of the multifilament in a state that the braid is unbraided are shown in Table 3.

Comparative Example 2-1

(43) A braid was produced by braiding 4 multifilaments of Comparative Example 1-1 such that a braiding angle was adjusted to 20. The braid was subjected to heat treatment by heating in a hot air heating furnace set at 142 C. A time for the heat treatment was set to 0.08 minutes, a tension applied to the braid during the heat treatment was set to 4.3 cN/dtex, and a re-draw ratio was set to 1.04 times. The braid production conditions, the physical properties and evaluation results of the braid obtained, and the physical properties of the multifilament in a state that the braid is unbraided are shown in Table 3.

Comparative Example 2-2

(44) A multifilament was obtained in the same manner as in Example 2-1, except that the heat treatment temperature was set to 135 C., the heat treatment time was set to 35 minutes, the tension during the heat treatment was set to 0.005 cN/dtex, and the re-draw ratio was set to 1.01 times in Comparative Example 2-1. The braid production conditions, the physical properties and evaluation results of the braid obtained, and the physical properties of the multifilament in a state that the braid is unbraided are shown in Table 3.

Comparative Example 2-3

(45) A multifilament was obtained in the same manner as in Example 2-1, except that the heat treatment temperature was set to 145 C., the heat treatment time was set to 35 minutes, the tension during the heat treatment was set to 0.01 cN/dtex, and the re-draw ratio was set to 1.02 times in Example 2-1. The braid production conditions, the physical properties and evaluation results of the braid obtained, and the physical properties of the multifilament in a state that the braid is unbraided are shown in Table 3.

Comparative Example 2-4

(46) A braid was produced by braiding 4 multifilaments of Example 1-1 such that a braiding angle was adjusted to 20. The braid was heated in a hot air heating furnace set at 65 C. and subjected to heat treatment so as to have a re-draw ratio of 1.50 times; however, the multifilament was cut in the middle of the re-drawing, and thus no braid could be obtained.

Comparative Example 2-5

(47) A braid was produced by braiding 4 multifilaments of Comparative Example 1-5 such that a braiding angle was adjusted to 20. The braid was subjected to heat treatment by heating in a hot air heating furnace set at 139 C. A time for the heat treatment was set to 35 minutes, a tension applied to the braid during the heat treatment was set to 0.05 cN/dtex, and a re-draw ratio was set to 1.05 times. The braid production conditions, the physical properties and evaluation results of the braid obtained, and the physical properties of the multifilament in a state that the braid is unbraided are shown in Table 3.

Comparative Example 2-6

(48) A braid was produced by braiding 4 multifilaments of Comparative Example 1-6 such that a braiding angle was adjusted to 20. The braid was subjected to heat treatment by heating in a hot air heating furnace set at 139 C. A time for the heat treatment was set to 35 minutes, a tension applied to the braid during the heat treatment was set to 0.03 cN/dtex, and a re-draw ratio was set to 1.05 times. The braid production conditions, the physical properties and evaluation results of the obtained braid, and the physical properties of the multifilament in a state that the braid is unbraided are shown in Table 3.

(49) TABLE-US-00003 TABLE 3 braid Example Example Example Example Example 2-1 2-2 2-3 2-4 2-5 multifilament used Example Example Example Example Example 1-1 1-1 1-1 1-2 1-2 Production Heat treatment temperature [ C.] 151 151 152 151 151 method for the Heat treatment time [] 1.5 min 1.5 min 2.0 min 1.0 min 2.0 min braid Tension during the heat treatment [cN/dtex] 1.6 2.4 3.8 1.4 2.7 Draw ratio during heat treatment [] 2.00 3.00 4.00 1.80 3.80 Physical Tensile strength (A) [cN/dtex] 23 26 29 19 24 properties of the Elongation at break [%] 4.0 3.4 3.1 4.4 3.7 braid Initial modulus [cN/dtex] 772 941 1023 406 863 Number of yarn constituting the braid [number] 4 4 4 4 4 Thermal shrinkage at 120 C. [%] 1.1 0.8 0.6 1.7 1.4 Number of reciprocating abrasions at break at a load of [times] 2567 2364 1816 3746 3290 5 cN/dtex (B) Structure of Maximum value of the peak intensity ratio [] 0.36 0.38 0.40 0.32 0.35 multifilament in Minimum value of the peak intensity ratio [] 0.27 0.28 0.31 0.21 0.24 state that braid is Difference of the maximum value of the peak intensity [] 0.09 0.10 0.09 0.10 0.11 unbraided ratio and the minimum value of the peak intensity Coefficient of variation of the peak intensity [%] 11 12 11 14 15 Maximum value of the degree of crystal orientation [] 0.989 0.994 0.995 0.980 0.982 Minimum value of the degree of crystal orientation [] 0.983 0.989 0.990 0.975 0.976 Difference between the maximum value of the degree of [] 0.006 0.005 0.005 0.005 0.006 crystal orientation and the minimum value of the degree of crystal orientation Physical Titer of monofilament in multifilament [dtex] 4.1 3.3 2.4 6.3 3.5 properties of Tensile strength (C) [cN/dtex] 25 28 33 20 27 multifilament in Difference between tensile strength (A) and tensile [cN/dtex] 2 2 4 1 3 state that braid strength (C) is unbraided Diameter of monofilament [m] 25 22 19 31 23 Elongation at break [%] 4.1 4.0 3.9 4.2 4.0 Initial modulus [cN/dtex] 900 950 1020 710 760 Thermal stress at 120 C. [cN/dtex] 0.17 0.21 0.24 0.16 0.22 Thermal shrinkage at 70 C. [%] 0.08 0.06 0.05 0.10 0.08 Thermal shrinkage at 120 C. [%] 1.8 1.6 1.2 2.1 1.7 Number of reciprocating abrasions at break at a load of [times] 2790 2482 1920 3810 3329 5 cN/dtex (D) Number of reciprocating abrasions at break at a load of [times] 275 241 199 329 291 10 cN/dtex Difference between (B) and (D) [times] 223 118 104 64 39 braid Comparative Comparative Comparative Example Example Example 2-1 2-2 2-3 multifilament used Comparative Comparative Example Example Example 1-1 1-1 1-1 Production Heat treatment temperature [ C.] 142 135 145 method for the Heat treatment time [] 0.08 sec 35 min 35 min braid Tension during the heat treatment [cN/dtex] 4.3 0.005 0.01 Draw ratio during heat treatment [] 1.04 1.01 1.02 Physical Tensile strength (A) [cN/dtex] 14 6 9 properties of the Elongation at break [%] 5.1 5.6 5.3 braid Initial modulus [cN/dtex] 305 125 210 Number of yarn constituting the braid [number] 4 4 4 Thermal shrinkage at 120 C. [%] 3.6 5.1 4.9 Number of reciprocating abrasions at break at a load of [times] 426 407 439 5 cN/dtex (B) Structure of Maximum value of the peak intensity ratio [] 0.31 0.29 0.30 multifilament in Minimum value of the peak intensity ratio [] 0.06 0.09 0.06 state that braid is Difference of the maximum value of the peak intensity [] 0.25 0.20 0.24 unbraided ratio and the minimum value of the peak intensity Coefficient of variation of the peak intensity [%] 62 46 59 Maximum value of the degree of crystal orientation [] 0.968 0.957 0.965 Minimum value of the degree of crystal orientation [] 0.953 0.943 0.951 Difference between the maximum value of the degree of [] 0.015 0.014 0.014 crystal orientation and the minimum value of the degree of crystal orientation Physical Titer of monofilament in multifilament [dtex] 1.6 2.5 2.5 properties of Tensile strength (C) [cN/dtex] 16 17 16 multifilament in Difference between tensile strength (A) and tensile [cN/dtex] 2 11 7 state that braid strength (C) is unbraided Diameter of monofilament [m] 16 20 20 Elongation at break [%] 2.9 4.5 4.7 Initial modulus [cN/dtex] 550 405 475 Thermal stress at 120 C. [cN/dtex] 0.14 0.04 0.06 Thermal shrinkage at 70 C. [%] 0.12 0.14 0.13 Thermal shrinkage at 120 C. [%] 1.9 2.4 2.2 Number of reciprocating abrasions at break at a load of [times] 781 801 812 5 cN/dtex (D) Number of reciprocating abrasions at break at a load of [times] 42 48 56 10 cN/dtex Difference between (B) and (D) [times] 355 394 373 braid Comparative Comparative Comparative Example Example Example 2-4 2-5 2-6 multifilament used Example Comparative Comparative 1-1 Example Example 1-5 1-6 Production Heat treatment temperature [ C.] 65 139 139 method for the Heat treatment time [] 35 min 35 min braid Tension during the heat treatment [cN/dtex] 0.05 0.03 Draw ratio during heat treatment [] 1.50 1.05 1.06 Physical Tensile strength (A) [cN/dtex] multifilament 10 11 properties of the Elongation at break [%] was cut in the 5.8 5.7 braid Initial modulus [cN/dtex] middle of the 302 280 Number of yarn constituting the braid [number] drawing 4 4 Thermal shrinkage at 120 C. [%] 3.5 4.2 Number of reciprocating abrasions at break at a load of [times] 201 448 5 cN/dtex (B) Structure of Maximum value of the peak intensity ratio [] 0.30 0.31 multifilament in Minimum value of the peak intensity ratio [] 0.09 0.08 state that braid is Difference of the maximum value of the peak intensity [] 0.21 0.23 unbraided ratio and the minimum value of the peak intensity Coefficient of variation of the peak intensity [%] 43 51 Maximum value of the degree of crystal orientation [] 0.977 0.968 Minimum value of the degree of crystal orientation [] 0.932 0.938 Difference between the maximum value of the degree of [] 0.045 0.030 crystal orientation and the minimum value of the degree of crystal orientation Physical Titer of monofilament in multifilament [dtex] 1.2 4.9 properties of Tensile strength (C) [cN/dtex] 30 21 multifilament in Difference between tensile strength (A) and tensile [cN/dtex] 20 10 state that braid strength (C) is unbraided Diameter of monofilament [m] 10 26 Elongation at break [%] 4.7 4.6 Initial modulus [cN/dtex] 960 515 Thermal stress at 120 C. [cN/dtex] 0.05 0.06 Thermal shrinkage at 70 C. [%] 0.13 0.15 Thermal shrinkage at 120 C. [%] 2.3 2.3 Number of reciprocating abrasions at break at a load of [times] 343 819 5 cN/dtex (D) Number of reciprocating abrasions at break at a load of [times] 13 58 10 cN/dtex Difference between (B) and (D) [times] 142 371

INDUSTRIAL APPLICABILITY

(50) The present invention can provide a multifilament and a braid that are capable of being processed into products in a wide range of temperature and are excellent in dimensional stability and abrasion resistance. The multifilament and the braid according to the present invention can be usable for industrial materials such as cut resistant woven and knitted products for protection, tapes, ropes, nets, fishing lines, protection covers for materials, sheets, strings for kites, archery chords, sail cloths, curtain materials, protection materials, bulletproof materials, medical sutures, artificial tendons, artificial muscles, reinforcing materials for fiber-reinforced resins, cement reinforcing materials, reinforcing materials for fiber-reinforced rubber, machine tool components, battery separators and chemical filters.