JP2020133061A - Polyamide 610 multifilament for rope - Google Patents

Abstract

To provide a high-strength low-water-absorption multifilament of polyamide 610, wherein the multifilament is suitable for a rope by solving issues of a polyamide multifilament caused by water absorption.SOLUTION: The multifilament of polyamide 610 for a rope is characterized by that its strength retention on water absorption is 90% or over and a rate of a strength of a rope after treatment of water absorption-dehydration and a strength of a rope untreated of water absorption of 1.4 or under.SELECTED DRAWING: None

Description

The present invention relates to polyamide multifilaments for ropes.

Polyamide 6 and polyamide 66 multifilaments have higher strength and elongation than general-purpose multifilaments such as polyester and polypropylene, and have excellent fluff quality. Therefore, airbags, tire cords, sports racket guts, ropes, fishing nets, and bags It is used for a wide range of purposes such as belts.

Among the above-mentioned applications, in the rope field, it has been used for many years from the viewpoint of high strength elongation, high abrasion resistance, and durability of polyamides 6 and 66. (Patent Document 1)
Rope used in the field of industrial materials, especially ropes for mooring ships or various construction sites, is required to have strength and durability as ropes. In addition to ropes for mooring ships used in seawater, ropes for industrial materials are often used outdoors for a long period of time, and since the ropes are exposed to wind and rain, it is necessary to assume a water absorption state in addition to a dry state. There is. On the other hand, it is also important for a ship mooring rope to have the ability to float on the water surface for a long time without submerging in water. For example, hollow polyamide 6 fibers for ropes have been proposed (Patent Document 2). Although it has excellent water floating property, there is a concern that its strength will decrease when it absorbs water.

Polyamides used in ropes are generally water-absorbent and hygroscopic polymers. In the so-called general-purpose polyamide multifilament such as polyamide 6 and polyamide 66, the strength decreases due to water absorption and the dimensional change due to moisture absorption is large. Therefore, there is a problem that the rope is hardened or the abrasion resistance is lowered due to the decrease in strength due to water absorption and the repetition of water absorption and drying. When the rope is hardened, various practical problems such as deterioration of workability related to the installation of the rope and deterioration of storability after winding occur.

On the other hand, as low water absorption polyamide multifilaments, polyamide 11, polyamide 610, and polyamide 612 multifilaments are known. For example, they have been proposed as fibers for cleaning brushes (Patent Document 3), but they are manufactured by a conventional method. Since these polyamide multifilaments have lower strength and poorer fluff quality than polyamide 6 and polyamide 66, it has been difficult to develop them into rope applications that require high strength multifilaments.

Japanese Unexamined Patent Publication No. 9-95877 Japanese Unexamined Patent Publication No. 2003-55836 Japanese Unexamined Patent Publication No. 2011-1635

An object of the present invention is to provide a multifilament particularly suitable for rope applications by using a high-strength, low-water absorption polyamide multifilament that cannot be obtained by the prior art.

The present inventors have diligently studied in order to solve the above problems, and the present invention has the following configuration.

(1) For ropes characterized in that the strong retention rate at the time of water absorption is 90% or more, and the ratio of the hardness of the rope after the water absorption-drying treatment to the hardness of the rope not treated with water absorption is 1.4 or less. Polyamide 610 multifilament.

(2) The polyamide 610 multifilament for rope according to (1) above, wherein the total fineness is 400 to 4000 dtex and the single fiber fineness is 4 to 40 dtex.

(3) The above-mentioned (1), wherein the relative viscosity of sulfuric acid is 3.3 to 3.7, the strength at drying is 7.3 to 9.3 cN / dtex, and the elongation at drying is 19 to 30%. Alternatively, the polyamide 610 multifilament for rope according to (2).

(4) The above-mentioned (1) to (3), wherein the dimensional change rate of the rope at the time of water absorption is 5% or less, and the strong holding rate of the rope at the time of water absorption by the tensile fatigue test is 50% or more. The polyamide 610 multifilament for rope according to any one.

(5) A rope according to any one of (1) to (4) above, wherein the polyamide 610 multifilament for rope is used.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a polyamide 610 multifilament which exhibits strength and fluff quality equivalent to those of polyamide 6 and polyamide 66 multifilament, and exhibits low water absorption and water absorption-drying characteristics required for rope applications. Become.

FIG. 1 is a schematic view of a direct spinning and drawing apparatus preferably used in the present invention.

The raw material for the polyamide 610 multifilament of the present invention is polyamide 610. It is preferable that the polymer is composed of only the polyamide 610, but it is sufficient that the polymer is substantially composed of the polyamide 610, and other polymers can be contained in a range of 5% by mass or less without impairing the characteristics of the present invention. It may be mixed or copolymerized. Polyamides such as polyamides 6, 66, 11 and 12 are preferable as the polymer / copolymerization unit to be mixed or copolymerized.

The polyamide 610 multifilament of the present invention needs to have a strong retention rate of 90% or more at the time of water absorption. It is more preferably 95% or more, still more preferably 98% or more. When the strong retention rate at the time of water absorption is 90% or more, it is possible to suppress a decrease in strength at the time of water absorption as compared with the general-purpose polyamides 6 and 66. The strong retention rate at the time of water absorption means a value measured by a method described later.

The ratio of the hardness after water absorption treatment (after water absorption-drying treatment) to the hardness without water absorption treatment (water absorption-after drying treatment / hardness without water absorption treatment) of the rope using the polyamide 610 multifilament of the present invention is 1.4. It is necessary that it is less than or equal to 1.2 or less, more preferably 1.2 or less. When the hardness ratio before and after the water absorption treatment exceeds 1.4, the rope feels tight and hard to the touch after repeated water absorption and drying. In addition, workability such as tying, unraveling, and connecting is deteriorated, and storability after winding occurs due to hardening. The hardness after the water absorption treatment means a value measured by a method described later.

The total fineness of the polyamide 610 multifilament of the present invention is preferably 400 to 4000 dtex, more preferably 700 to 2000 dtex. Although it can be used even if it is less than 400 dtex, it is not preferable if the total fineness is small because it is usually processed into a target product by blending or twisting. On the other hand, a multifilament having a total fineness exceeding 4000 dtex can also be obtained, but if a thread having a large total fineness is required, it may be appropriately combined and used, and a multifilament having a large total fineness is intentionally used using a large silk reeling facility. There is no need to manufacture filaments.

The single fiber fineness is preferably 4 to 40 dtex, more preferably 5 to 15 dtex. Polyamide 610 multifilament having a single fiber fineness of less than 4 dtex has low wear resistance with a drawn roll in the silk reeling process, and the fluff quality deteriorates when the draw ratio is increased in order to obtain high-strength fibers. On the other hand, if it exceeds 40 dtex, it may be too hard or it may be difficult to focus the filament. In addition, there are problems that it is difficult to cool the polymer in the spinning process, uniform stretching is not performed in the spinning process, and the form deteriorates when the polymer is wound in a cheese shape at a high speed of 3000 m / min or more. ..

The relative viscosity of sulfuric acid (hereinafter, also simply referred to as viscosity) of the raw material chip of the polyamide 610 multifilament of the present invention is preferably 3.6 to 4.0, more preferably 3.7 to 3.9, and further. It is preferably 3.7 to 3.8. If the viscosity of the chip is 3.5 or less, it may be difficult to stably obtain the polyamide 610 multifilament of the present invention when the water content of the chip is set in the following preferable range. The relative sulfuric acid viscosity refers to a value measured at 25 ° C. using an Ostwald viscometer after dissolving the sample in 98% sulfuric acid.

The water content of the chip of the polyamide 610, which is the raw material of the polyamide 610 multifilament of the present invention, is preferably 0.05% or more, particularly preferably 0.05 to 0.13%, and further 0.07. It is preferably ~ 0.09%. Since polyamide 610 does not easily absorb water, it is suggested that the influence of the water content is small, but the viscosity adjustment by adjusting the water content dramatically improves the strong elongation and the fluff quality. If the water content is less than 0.05%, the fluff quality deteriorates. As a method for adjusting the water content, a method of adding lightweight water to the dried chips and stirring the chips is preferable, but any method can be used as long as the above range is achieved.

The polyamide 610 multifilament of the present invention preferably has a sulfuric acid relative viscosity of 3.3 to 3.7, particularly preferably 3.3 to 3.6, and further preferably 3.4 to 3.6. Is preferable. If the viscosity is less than 3.3, a raw yarn having sufficient strength cannot be obtained with good fluff quality, and if the viscosity is 3.8 or more, the silk-reeling property and fluff quality deteriorate.

As described above, in order to dramatically improve the strength and fluff quality of the polyamide 610 multifilament, the viscosity of the raw material chip is 3.6 in order to control the balance between polymerization and decomposition of the polymer due to heat in the spinning machine. It is important that the water content is ~ 4.0 and the water content is 0.05 to 0.13%, and the viscosity of the polyamide 610 multifilament is 3.3 to 3.7.

The strength of the polyamide 610 multifilament of the present invention is preferably 7.3 to 9.3 cN / dtex, more preferably 8.0 to 9.2 cN / dtex, and further preferably 8.3 to 8.9 cN / dtex. Is more preferable. When high-strength fibers are produced by a usual method, fluff is likely to occur. However, by adjusting the water content and the above viscosity range used in the present invention, fluff generation, thread breakage, etc. in the spinning and drawing steps are suppressed, and the quality is improved. Polyamide multifilament with high viscosity can be obtained.

The elongation of the polyamide 610 multifilament of the present invention is preferably 19 to 30%, more preferably 20 to 25%. In particular, it is possible to obtain a high-quality polyamide multifilament, which is particularly effective in a polyamide multifilament having a strength in the above range and an elongation range, suppressing fluffing and thread breakage. it can.

The dimensional change rate at the time of water absorption of the rope using the polyamide 610 multifilament of the present invention is preferably 5% or less, and more preferably 4% or less. Generally, by repeating water absorption and drying, a rope composed of water absorbing fibers such as polyamide 6 expands and contracts, but in a rope using the polyamide 610 multifilament of the present invention, even if water absorption and drying are repeated. When the expansion and contraction is small, specifically, when the dimensional change rate is 5% or less, the deformation of the rope is small even under the condition of repeated loading in water, and the durability is improved. The rope manufacturing method and the water absorption conditions of the rope refer to the manufacturing method and the treatment method described later.

The strong retention rate by the tensile fatigue test at the time of water absorption of the rope using the polyamide 610 multifilament of the present invention is preferably 50% or more, more preferably 60% or more, still more preferably 75% or more. .. When the strong retention rate in the tensile fatigue test at the time of water absorption is 50% or more, the rope becomes less fatigued and more durable in applications such as ship mooring ropes where a strong load is repeatedly applied in water. The water absorption conditions of the rope and the strong retention rate by the tensile fatigue test are the values measured by the treatment method described later.

Next, a method for producing the polyamide 610 multifilament of the present invention will be described. The polyamide 610 multifilament can be preferably produced by the following method based on ordinary melt spinning, but in the present invention, it is particularly effective to produce the polyamide 610 filament by the direct spinning and drawing method. Further, when performing melt spinning, it is preferable to apply a predetermined amount of water after controlling the tip to an appropriate viscosity, thereby improving the strength and elongation and suppressing the occurrence of yarn breakage and fluff during drawing. As a result, a polyamide 610 multifilament having high strength and excellent quality can be obtained.

Hereinafter, FIG. 1 will be described as an example.

FIG. 1 is a schematic view of a direct spinning and drawing apparatus preferably used in the present invention.
A polyamide 610 chip whose viscosity, moisture content, etc. have been adjusted is melted and kneaded with an extruder type spinning machine (not shown in FIG. 1), and is discharged from a spinneret 1 at a spinning portion to spin. The spinning temperature is generally 30 ° C. or higher higher than the melting point of the target polymer. If the temperature is lower than 30 ° C., the polymer will not be uniformly melted due to insufficient heat, and the melt viscosity will be high, resulting in unstable spinnability. The spun yarn 5 spun from the spinneret 1 passes through the heating cylinder 2 and is cooled by the cooling air 4 by the cross-flow cooling device 3. The cooled thread 5 passes through the duct 6 and is picked up by the take-up roller 8 while being applied with the treatment agent by the refueling device 7. The taken-up thread 5 is pre-stretched and stretched between the taking-up roller 8 and the thread feeding roller 9. After that, the first stretching roller 10, the second stretching roller 11, and the third stretching roller 12 are stretched in three stages, and the relaxation roller 13 is relaxed. The relaxed yarn 5 is entangled by the entanglement applying device 14, and is wound by the winder 15 to form a fiber package 16.

As described above, the viscosity of the polyamide 610 chip used as a raw material is preferably 3.6 to 4.0, and the moisture content is preferably 0.05% or more.

In the above, the pick-up speed at the time of picking up is preferably 350 to 1100 m / min, preferably 400 to 800 m / min. The treatment agent in the present invention is preferably used as a non-aqueous treatment agent, but sufficient physical properties can be obtained even if a water-containing treatment agent is used. As a method of applying the treatment agent, an oiling roll device or a guide lubrication is preferable.

The step from stretching to winding is usually preferably a method in which two or more stages of multi-stage stretching are performed, and then relaxation treatment is performed for winding. When stretching in two or more stages, it is preferable to perform pre-stretch stretching and then stretching. It is preferable that the pre-stretch stretching and the first-stage stretching are performed by heat stretching around the glass transition temperature, and the remaining stretching and heat setting temperature are usually performed at a high temperature of 150 to 220 ° C. More preferably, it is 170 to 210 ° C.

The draw ratio, that is, the ratio between the take-up roller 8 and the second draw roller 11 is usually in the range of 3 to 6 times. In addition. The winding speed is usually preferably 2000 to 5000 m / min, more preferably 2500 to 4500 m / min. Further, it is preferable to wind the cheese strip with a winding device under the condition that the winding tension is 20 to 250 gf.

The polyamide 610 multifilament of the present invention can be produced by the above method.

The rope of the present invention is usually synthesized by twisting several multifilaments obtained as described above. The total number of ropes, that is, the diameter of the rope structure may be appropriately set according to the intended use and required characteristics. For example, many ropes for mooring small ships are designed by twisting about 20 to 100 multifilaments of about 1400 dtex, and ropes for mooring large ships are made by twisting about 100 1400 dtex. Some are made by twisting about 100 ropes. As for the twist, the lower twist, the middle twist, the upper twist, etc. may be set depending on the intended use.

The present invention will be described in detail below based on examples. The present invention is not limited to these examples. The measurement method of each measured value in the examples is as follows.

(1) Sulfuric acid relative viscosity (ηr): Using a polymer chip or raw yarn (filament) as a sample, 0.25 g of the sample was dissolved in 25 mL of 98% sulfuric acid, measured at 25 ° C. using an Ostwald viscometer, and calculated from the following formula. I asked. The measured value was obtained from the average value of 5 samples.
ηr = seconds of sample solution flowing down / seconds of sulfuric acid only flowing down.

(2) Moisture content: Measured using a combination of Hiranuma Sangyo's moisture measuring device AQ-2200 and Hiranuma Sangyo's moisture vaporizer EV-2000. That is, the water content in the sample chip was extracted using EV-2000 of Hiranuma Sangyo, and the water content was measured using AQ-2200 of Hiranuma Sangyo. The sample was 1.5 g, and the nitrogen used for water vaporization was 0.2 L / min.
The measurement conditions were as follows.
・ Step 1 Temperature 210 ℃, time 21 minutes ・ Dry baking time 0 minutes ・ End BG 0 μg
・ Cooling time 1 minute ・ BG stable 30 times ・ Back purge time 20 seconds.

(3) Total fineness: The positive fineness was measured with a predetermined load of 0.045 cN / dtex by the JIS L1013 (1999) 8.3.1 A method to obtain the total fineness.

(4) Number of filaments: Calculated by the method of JIS L1013 (1999) 8.4.

(5) (Drying) Strength, strength, elongation: JIS L1013 (1999) 8.5.1 Measured under the constant speed elongation conditions shown in the standard time test. The sample was a "TENSILON" UCT-100 manufactured by Orientec Co., Ltd., and the gripping interval was 250 mm and the tensile speed was 300 mm / min. The strength was calculated from the maximum strength on the SS curve, and the strength was calculated by dividing the strength by the total fineness.

(6) Strong retention rate at the time of water absorption: JIS L1013 (1999) 8.3.1 A skein with a predetermined thread length was prepared in the manner of A method, and the skein was immersed in tap water at 20 ° C. for 24 hours. After 24 hours, the skein was taken out and measured within 10 minutes under the constant speed extension conditions shown in the JIS L1013 (1999) 8.5.1 standard time test. The water absorption strength obtained by this measurement was divided by the dry strength (measured in the above item (5)) to express the percentage, and the water absorption strength retention rate was calculated.

(7) Hardness of untreated rope with water absorption: A C-type durometer manufactured by ASKER was used to measure the hardness. A rope of about 1 m was placed on a flat place such as a desk, and the hardness of 10 points per rope was measured at intervals of 10 cm, and the values were averaged to determine the hardness of the untreated (dry) rope.

(8) Water Absorption-Drying Treatment Rope hardness: A rope having a hardness of about 1 m was prepared and immersed in tap water at 20 ° C. for 30 minutes. After 30 minutes, the rope was taken out of the water, wiped with a cloth or the like so that water did not drip, and dried in a room at a temperature of 20 ° C. and a humidity of 65% for 24 hours. After repeating the above water absorption-drying operation four times, the rope hardness was measured at 10 points as described in item (7), and the average value was determined as the hardness of the water absorption-drying treated rope.

(9) Rope Dimensional Change Rate During Water Absorption: After immersing the rope (φ17) in water for 18 days, a repeated elongation test of the rope was carried out by a tensile tester. In the repeated elongation test, the distance between the reference points was taken at the time of the initial load, and after loading the load of 9810N in the water absorption state, the elongation was measured by holding for 1 minute. This was repeated 10 times, and the difference between the elongation at the initial load and the elongation at the 10th time was taken as the dimensional change rate.

(10) Strong retention rate by tensile fatigue test of rope during water absorption: A tensile test was carried out with a rope in a dry state before water absorption, and the initial strength was evaluated. Subsequently, while dripping water on another rope, tensile fatigue was applied to the rope by repeating 100,000 times while applying a load of a standard strength. A tensile test was carried out using a rope to which tensile fatigue was applied, and the tensile strength after the tensile fatigue test was evaluated. The tensile strength obtained by this measurement was divided by the initial strength and expressed as a percentage, and the tensile strength was obtained by the tensile fatigue test of the rope during water absorption. Rope that broke during the tensile fatigue test was recorded as ruptured.

[Example 1]
A 5% by weight aqueous solution of copper acetate was added as an antioxidant to the polyamide 610 chip obtained by the liquid phase polymerization and mixed, and 70 ppm of copper was added and adsorbed with respect to the polymer weight. Next, a 50% by weight aqueous solution of potassium iodide and a 20% by weight aqueous solution of potassium bromide were added and adsorbed to 100 parts by weight of the polyma chip so as to be 0.1 part by weight of potassium, respectively, and solidified using a solid phase polymerization apparatus. After the phase polymerization, water was added to obtain a polyamide 610 chip having the relative viscosity and water content of the sulfuric acid shown in Table 1.

The apparatus shown in FIG. 1 was used as the spinning apparatus. The above-mentioned polyamide 610 chip was supplied to the extruder, and the discharge amount was adjusted by a measuring pump so that the total fineness was about 1400 dtex. The spinning temperature was 285 ° C., the mixture was filtered through a metal non-woven fabric filter in a spinning pack, and then spun through a spinneret having 204 holes. The spun yarn was passed through a heating cylinder heated to a temperature of 250 ° C. and then cooled and solidified by a cooling air having a wind speed of 40 m / min. A water-containing treatment agent was applied to the cooled and solidified yarn, and the yarn was swirled by a spinning take-up roller to take the yarn. The taken-up threads are then stretched by 5% between the take-up roller 8 and the thread feeder 9 without being wound up, and then between the thread feeder 9 and the first drawing roller 10. The first-stage stretching is performed so that the rotation speed ratio between the rollers is 2.6, and then the rotation speed ratio between the first stretching rollers 10 and the second stretching rollers 11 is 1.35. The second step of stretching was performed. Subsequently, the third-stage stretching was performed between the second stretching roller 11 and the third stretching roller 12 so that the rotation speed ratio between the rollers was 1.35. The rotation speed ratio between the take-up roller 8 and the third stretching roller 12 was set to 5.0.

Subsequently, a 5% relaxation heat treatment was performed between the third stretching roller 12 and the relaxation roller 13, the threads were entangled by the entanglement applying device, and then wound by the winding machine 14. The surface temperature of each roller was set so that the take-up roller was at room temperature, the thread feeding roller was 40 ° C, the first stretching roller was 95 ° C, the second stretching roller was 150 ° C, the third stretching roller was 200 ° C, and the relaxing roller was 140 ° C. The entanglement treatment was performed by injecting high-pressure air from the direction perpendicular to the traveling thread in the entanglement applying device. Guides for regulating running threads were provided before and after the entanglement applying device, and the pressure of the injected air was kept constant at 0.2 MPa. Under the above conditions, a 1400 dtex polyamide 610 multifilament was obtained.

Next, three 1400 dtex polyamide 610 multifilaments obtained were aligned and subjected to a Z bottom twist of 80 T / m, and then eight were further aligned and subjected to an S medium twist of 120 T / m to prepare a strand, and finally. A rope having a diameter of 17 mm was produced by twisting 6 ropes on a Z top at 130 T / m.

[Example 2]
The first-stage stretching is performed between the thread feeding roller 9 and the first stretching roller 10 so that the rotation speed ratio between the rollers is 2.5, and the roller is between the first stretching roller 10 and the second stretching roller 11. Second-stage stretching so that the rotation speed ratio between the two is 1.30, and three stages so that the rotation speed ratio between the second stretching rollers 11 and the third stretching roller 12 is 1.32. It was produced in the same manner as in Example 1 except that the eyes were stretched and the rotation speed ratio between the take-up rollers 8 and the third stretching rollers 12 was changed to 4.5.

[Example 3]
Using the polyamide 610 pellets having the relative viscosity and water content of sulfuric acid shown in Table 1, the production was carried out in the same manner as in Example 1 except that the discharge amount was adjusted by a measuring pump so as to have a total fineness of 1000 dtex.

[Example 4]
Using polyamide 610 pellets with relative sulfuric acid viscosity and moisture content in Table 1, the discharge rate was adjusted by a measuring pump so that the total fineness was 1000 dtex, and rotation between the rollers 9 and the first stretching roller 10 was performed. First-stage stretching so that the speed ratio is 2.4, second-stage stretching between the first stretching roller 10 and the second stretching roller 11 so that the rotation speed ratio between the rollers is 1.30. The third-stage stretching is performed between the two stretching rollers 11 and the third stretching roller 12 so that the rotation speed ratio between the rollers is 1.22, and between the taking-up rollers 8 and the third stretching rollers 12. It was manufactured by the same method as in Example 1 except that the rotation speed ratio of was changed to 4.0.

[Comparative Example 1]
The polyamide 6 chips obtained by liquid phase polymerization were mixed by adding a 5% by weight aqueous solution of copper acetate as an antioxidant, and 68 ppm as copper was added and adsorbed with respect to the polymer weight. Next, a 50% by weight aqueous solution of potassium iodide and a 20% by weight aqueous solution of potassium bromide were added and adsorbed to 100 parts by weight of the polyma chip so as to be 0.1 part by weight of potassium, respectively, and solidified using a solid phase polymerization apparatus. After the phase polymerization, water was added to obtain polyamide 6 pellets having the relative viscosity and water content of sulfuric acid in Table 1. The apparatus shown in FIG. 1 was used as the spinning apparatus. The above-mentioned polyamide 6 chips were supplied to the extruder, and the discharge amount was adjusted by a measuring pump so that the total fineness was about 1400 dtex.

The spinning temperature was 270 ° C., the mixture was filtered through a metal non-woven fabric filter in a spinning pack, and then spun through a spinneret having 204 holes. The spun yarn was passed through a heating cylinder heated to a temperature of 270 ° C. and then cooled and solidified by a cooling air having a wind speed of 30 m / min. Subsequent conditions were produced in the same manner as in Example 1. A water-containing treatment agent was applied to the cooled and solidified yarn, and the yarn was swirled by a spinning take-up roller to take the yarn. The taken-up thread is then stretched by 9% between the take-up roller 8 and the thread feeder 9 without being wound up, and then the roller between the thread feeder 9 and the first drawing roller 10. The first-stage stretching is performed so that the rotation speed ratio between the rollers is 2.8, and then the rotation speed ratio between the first stretching rollers 10 and the second stretching rollers 11 is 1.4. The second step of stretching was performed. Subsequently, the third-stage stretching was performed between the second stretching roller 11 and the third stretching roller 12 so that the rotation speed ratio between the rollers was 1.2. The rotation speed ratio between the take-up roller 8 and the third stretching roller 12 was set to 4.9.

Subsequently, an 8% relaxation heat treatment was performed between the third stretching roller 12 and the relaxation roller 13, the threads were entangled by the entanglement applying device, and then wound by the winding machine 14. At this time, the total draw ratio represented by the take-up speed and the draw ratio was adjusted so as to be the ratios shown in Table 1, respectively. The surface temperature of each roller was set so that the take-up roller was at room temperature, the thread feeding roller was 45 ° C, the first stretching roller was 100 ° C, the second stretching roller was 160 ° C, the third stretching roller was 200 ° C, and the relaxing roller was 140 ° C. The entanglement treatment was performed by injecting high-pressure air from the direction perpendicular to the traveling thread in the entanglement applying device. Guides for regulating running threads were provided before and after the entanglement applying device, and the pressure of the injected air was kept constant at 0.3 MPa.

[Comparative Example 2]
The polyamide 66 chip obtained by liquid phase polymerization was mixed by adding a 5% by weight aqueous solution of copper acetate as an antioxidant, and 68 ppm as copper was added and adsorbed with respect to the polymer weight. Next, a 50% by weight aqueous solution of potassium iodide and a 20% by weight aqueous solution of potassium bromide were added and adsorbed to 100 parts by weight of the polyma chip so as to be 0.1 part by weight of potassium, respectively, and solidified using a solid phase polymerization apparatus. After the phase polymerization, water was added to obtain polyamide 66 pellets having the relative viscosity and water content of sulfuric acid in Table 1.

The apparatus shown in FIG. 1 was used as the spinning apparatus. The above-mentioned polyamide chips were supplied to the extruder, and the discharge amount was adjusted by a measuring pump so that the total fineness was about 1400 dtex. The spinning temperature was 295 ° C., the mixture was filtered through a metal non-woven fabric filter in a spinning pack, and then spun through a spinneret having 204 holes. The spun yarn was passed through a heating cylinder heated to a temperature of 280 ° C. and then cooled and solidified by a cooling air having a wind speed of 33 m / min. A water-containing treatment agent was applied to the cooled and solidified yarn, and the yarn was swirled by a spinning take-up roller to take the yarn. The taken-up thread is then stretched by 3% between the take-up roller 8 and the thread feeder 9 without being wound up, and then the roller between the thread feeder 9 and the first drawing roller 10. The first-stage stretching is performed so that the rotation speed ratio between the rollers is 2.8, and then the rotation speed ratio between the rollers is 1.3 between the first stretching roller 10 and the second stretching roller 11. The second step of stretching was performed. Subsequently, the third-stage stretching was performed between the second stretching roller 11 and the third stretching roller 12 so that the rotation speed ratio between the rollers was 1.3. The rotation speed ratio between the take-up roller 8 and the third stretching roller 12 was set to 4.9.

Subsequently, a 7% relaxation heat treatment was performed between the third stretching roller 12 and the relaxation roller 13, the threads were entangled by the entanglement applying device, and then wound by the winding machine 14. The surface temperature of each roller was set so that the take-up roller was at room temperature, the thread feeding roller was 55 ° C, the first stretching roller was 140 ° C, the second stretching roller was 205 ° C, the third stretching roller was 228 ° C, and the relaxation roller was 144 ° C. The entanglement treatment was performed by injecting high-pressure air from the direction perpendicular to the traveling thread in the entanglement applying device. Guides for regulating running threads were provided before and after the entanglement applying device, and the pressure of the injected air was kept constant at 0.3 MPa.

1: Spinning cap 2: Heating cylinder 3: Cross-flow cooling device 4: Cooling air 5: Thread 6: Duct 7: Refueling device 8: Pick-up roller 9: Thread feeding roller 10: First drawing roller 11: Second drawing roller 12: Third stretching roller 13: Relaxing roller 14: Entanglement device 15: Winder 16: Fiber package

Claims (5)

Polyamide 610 multi for rope, characterized in that the strong retention rate at the time of water absorption is 90% or more, and the ratio of the hardness of the rope after the water absorption-drying treatment to the hardness of the rope not treated with water absorption is 1.4 or less. filament. The polyamide 610 multifilament for rope according to claim 1, wherein the total fineness is 400 to 4000 dtex and the single fiber fineness is 4 to 40 dtex. The first or second claim, wherein the relative viscosity of sulfuric acid is 3.3 to 3.7, the strength at drying is 7.3 to 9.3 cN / dtex, and the elongation at drying is 19 to 30%. Polyamide 610 multifilament for rope. The rope according to any one of claims 1 to 3, wherein the dimensional change rate of the rope during water absorption is 5% or less, and the strong retention rate of the rope during water absorption by a tensile fatigue test is 50% or more. Polyamide 610 multifilament for. A rope according to any one of claims 1 to 4, wherein the polyamide 610 multifilament for rope is used.