JPWO2013129370A1 - Polyamide fiber and method for producing the same - Google Patents

Abstract

The present invention is a polyamide fiber having a polyamide having a specific structure, a strength of 3.5 cN / dtex or more, and an elongation of 70 to 150%. The polyamide fiber is obtained by discharging molten polyamide from a die, The yarn is cooled and solidified with cooling air, and a spinning oil is adhered to the yarn. Thereafter, the yarn is taken up and further wound up. The following conditions (a) and (b) are satisfied. (A) The distance from the outlet of the die to the oil for spinning is 500 mm or more and 1500 mm or less. (B) The take-up speed is 3300 m / min or more and 4300 m / min or less, and the take-up speed is 0.8 to 1.2 times the take-up speed. The present invention provides a polyamide fiber that has high elongation and can be processed with a wide variety of yarns, and a method for producing the polyamide fiber that is excellent in productivity.

Description

  The present invention relates to a high elongation polyamide fiber excellent in processability and a method for producing the same.

  Polyamide fibers typified by polyamide 6 fibers and polyamide 66 fibers, and polyester fibers typified by polyethylene terephthalate fibers and polybutylene terephthalate fibers are excellent in mechanical properties and dimensional stability. Therefore, these fibers are widely used not only for apparel but also for interiors, vehicle interior materials, industrial materials, and the like.

  Polyester fibers can be wound with high productivity by controlling the fiber structure (especially molecular chain orientation and crystallization) by being produced by high-speed spinning. Elongation is one of the characteristics showing the characteristics of the fiber structure. By changing the elongation, various processed yarns can be obtained from the fibers. For example, a false twisted yarn that imparts crimpability, and a drawn false twisted yarn having a thick portion and a thin portion that express tone. There are also fused false twisted yarns. In addition, there is a composite false twisted yarn in which a high elongation yarn and a low elongation yarn are combined to give a difference in yarn length between these fibers, thereby giving the texture characteristics. Thus, among polyester fibers, there are processed yarns rich in variations in order to add value, and polyester fibers are widely used.

  On the other hand, polyamide fibers have the following problems even if the fiber structure is controlled by the same manufacturing process as that for polyester fibers. Due to the progress of orientational crystallization due to environmental humidity, the fiber may swell during winding of the yarn, and as a result, a phenomenon may occur in which the yarn layer in the winding package is displaced and the yarn is ruptured. Therefore, the range of the elongation of the polyamide fiber that can be stably wound is limited. As a result, there are limitations on obtaining yarn-processing fibers for adding value, and polyamide-processed yarns have heretofore lacked variations.

  Therefore, in order to obtain a polyamide processed yarn rich in variations, there has been a demand for a polyamide fiber having high elongation that provides stable winding properties during yarn production.

  Until now, various proposals have been made to improve the elongation of polyamide fibers. For example, a high elongation polyamide fiber containing a specific amount of polyamide 610 and / or polyamide 612 having a specific range of relative viscosity in polyamide 6 has been proposed (see Patent Document 1).

  Further, a high-strength polymer alloy fiber in which a polyester represented by polyethylene terephthalate or polylactic acid is dispersed in polyamide 6 has been proposed (see Patent Document 2).

Further, it has been proposed that a polyamide having a glass transition point of 40 ° C. or higher is wound at a low speed and not stretched, or stretched at 2.5 times or less to obtain a polyamide having a high elongation (Patent Document). 3).

Japanese Patent Laid-Open No. 2002-339164 Japanese Unexamined Patent Publication No. 2005-206961 Japanese Unexamined Patent Publication No. 2004-27456

  According to the method described in Patent Document 1, oriented crystallization is suppressed, so that a high elongation polyamide fiber can be obtained. However, since it is inferior in durability as a final product, it is unsuitable for clothing use. In the method described in Patent Document 2, oriented crystallization is suppressed, so that a high elongation polyamide fiber can be obtained. However, when this fiber is used as a final product, peeling of the interface between the polyamide phase and the polyester phase occurs, and deterioration of wear resistance is a problem. Furthermore, in the method described in Patent Document 3, it is possible only in two steps in which spinning and stretching are separated, and the productivity is very poor and unsuitable for industrialization. In addition, since this fiber has an elongation of 220% or more, it has a very unstable crystal structure.

  It is an object of the present invention to provide a polyamide fiber and a method for producing the same excellent in productivity to obtain a processed yarn having high elongation and thereby being rich in variations.

In order to solve the problems, the present invention has the following configuration.
(1) A polyamide fiber having a strength of 3.5 cN / dtex or more and an elongation of 70 to 150% having a polyamide which is a polymer of structural formula A or a polyamide which is a polymer of structural formula B shown below.

In Structural Formula A, l is 9 to 12,
In Structural Formula B, (m + n) / 2 is 6-12.
(2) The polyamide fiber according to (1), wherein the polyamide is a polymer of the structural formula B.
(3) The polyamide fiber according to (1), wherein the polyamide is a polymer of structural formula A.
(4) A cheese-like package comprising any polyamide fiber in the previous period and having a bulge ratio represented by the following formula (I) of 10% or less.
B (%) = {(WB−WS) / WS} × 100 (I)
(B: bulge rate, WB: maximum package width (mm), WS: width at the start of package winding (mm)).
(5) The molten polyamide is discharged from the die to form a yarn, the yarn is cooled and solidified with cooling air, and a spinning oil is adhered to the yarn, and then the yarn is taken up and further wound. A method for producing a polyamide fiber according to any one of the preceding periods, which is a method for producing a polyamide fiber, which satisfies the following (a) and (b).
(A) The distance from the outlet of the die to the oil for spinning is 500 mm or more and 1500 mm or less (b) The take-up speed is 3300 m / min or more and 4300 m / min or less, and the take-up speed is 0.8 to 1. Double (6) A composite processed yarn comprising the polyamide fiber according to any one of the previous term and a fiber having an elongation of less than 70%.
(7) A fabric comprising the polyamide fiber according to any one of the previous term.

According to the present invention, it is possible to provide a polyamide fiber that can be wound with excellent productivity, has high elongation, and can be processed with a wide variety of yarns, and a method for producing the same.

2 types of cross-sections exemplified as irregular cross-section yarns of the polyamide fiber of the present invention. The conceptual diagram which shows an example of the manufacturing process of the synthetic fiber which concerns on this invention. Sectional drawing of the cheese-like package of this invention which concerns on this invention. Schematic which shows the manufacturing process of the composite process thread | yarn of the Example of this invention.

  Hereinafter, the polyamide fiber of the present invention will be described in more detail.

  The polymer used for the polyamide fiber of the present invention is a polyamide which is a polymer of structural formula A or a polymer of structural formula B in which a so-called hydrocarbon group is linked to the main chain via an amide bond.

The polymer of structural formula A is a polymer composed mainly of units represented by structural formula A, and the polymer of structural formula B is a polyamide which is a polymer composed mainly of units represented by structural formula B. is there. In Structural Formula A, l is 9-12. That is, in Structural Formula A, [CH ₂ ] / [NHCO], that is, the number of methylene groups per amide group is 9-12. Examples of structural formula A include polyamide 11 (10 methylene groups per amide group) and polyamide 12 (11 methylene groups per amide group). Here, the polymer may be a copolymer of different structural units included in the category of structural formula A.

  In Structural Formula B, (m + n) / 2 is 6-12. That is, in the structural formula B, it means that the number of methylene groups per amide group is 6-12. Examples of structural formula B include polyamide 410 (6 methylene groups per amide group), polyamide 510 (6.5 methylene groups per amide group), polyamide 610 (methylene groups per amide group). 7) and polyamide 612 (8 methylene groups per amide group). It may be a copolymer of different structures included in the category of structural formula B.

  In common with the polyamide having the structural formula A and the polyamide having the structural formula B, when the number of methylene groups per amide group is outside the scope of the present invention, the following characteristics tend to be obtained.

  If the number of methylene groups per amide is less than a specific amount, the number of amide bonds in the polymer increases and the moisture absorption rate increases. By the time when the polyamide fiber is wound up, it absorbs a large amount of spinning oil and moisture in the air, and as a result, the yarn swells with moisture, making stable spinning difficult. When the number of methylene groups per amide exceeds a specific amount, the melting point of the polymer decreases. In addition, amide bonds in the polyamide are reduced. Polyamide fibers are characterized by hygroscopicity and dyeability of fibers, but the expected hygroscopicity is difficult to obtain and dyeing becomes difficult, so the range of applicability to clothing is narrowed. In addition, intermolecular hydrogen bonds due to amide bonds are reduced, and the strength of the fiber tends to be lowered.

  Of the two types of polyamides, a polyamide substantially composed of the structural formula B is preferable, and (m + n) / 2 is more preferably 6 to 7 from the viewpoint of heat resistance and dyeability. Examples of such polyamides include polyamide 410, polyamide 510, and polyamide 610.

  The polyamide of the polymer of the structural formula A can be produced using aminocarboxylic acid or cyclic amide as a raw material. The polyamide of the structural formula B can be produced using dicarboxylic acid and diamine as raw materials. Hereinafter, these raw materials are collectively referred to as monomers. The monomers are not limited to petroleum-derived monomers, biomass-derived monomers, mixtures of petroleum-derived monomers and biomass-derived monomers, and the like. However, recently, it is preferable to include a biomass-derived monomer as a raw material because environmentally friendly polymers have attracted attention. In terms of excellent environmental adaptability, it is more preferable that 50% by mass or more of the monomers constituting the polyamide is a monomer obtained by using biomass. This biomass-derived monomer unit is preferably 75% by mass or more, and more preferably 100% by mass.

Examples of such a monomer include biomass-derived sebacic acid. This can be produced from castor oil. There is also a pentanediamine derived from biomass. This can be produced by fermenting glucose.
The polyamide of the present invention can be copolymerized with other components within a range not deteriorating the effects of the present invention. That is, as a high molecular weight substance substantially composed of a polymer composed of units represented by Structural Formula A and Structural Formula B, a component that generates units other than the units represented by Structural Formula A and Structural Formula B is used. It can copolymerize in the range which does not reduce the effect of invention. For example, a small amount of caproamide unit or hexamethylene adipamide unit can be copolymerized with the polyamide. Even in such a case, since the effect of the present invention can be achieved, it may be considered to be in the category of the polymer of the present invention. In the polyamide of the present invention, the unit represented by Structural Formula A or the unit represented by Structural Formula B is preferably contained in an amount of 90 mol% or more in all amide units. As a copolymerization component, as a copolymerization component that generates units other than the unit represented by Structural Formula A, aminocarboxylic acids, lactams, and amines (diamines, monoamines, etc.) that generate units not corresponding to Structural Formula A are used. Aliphatic monocarboxylic acid, aliphatic dicarboxylic acid, aromatic dicarboxylic acid and the like. Examples of the copolymer component that generates units other than the unit represented by Structural Formula B include aminocarboxylic acids and lactams, diamines that generate units other than the units represented by Structural Formula B, and dicarboxylic acids.

  The polyamide of the present invention preferably uses a polymer having a 98% sulfuric acid relative viscosity at 25 ° C. of 2.0 or more and 3.0 or less. If the 98% sulfuric acid relative viscosity is small, the molecular weight of the polyamide will be low, and it will be difficult to obtain sufficient strength when made into fibers. However, if the relative viscosity is too large, the extrusion pressure of the molten polymer during spinning increases. Furthermore, the extrusion pressure rises significantly faster during spinning, and the die must be replaced quickly.

  The polyamide fiber of the present invention includes various inorganic additives and organic additives such as matting agents, flame retardants, antioxidants, ultraviolet absorbers, infrared absorbers, crystal nucleating agents, fluorescent whitening agents, An antistatic agent, a hygroscopic agent (polyvinylpyrrolidone, etc.), an antibacterial agent (silver zeolite, zinc oxide, etc.) and the like can be contained. If the aforementioned additive can be copolymerized with polyamide, it may be copolymerized. The sum of the contents of these additives is preferably in the range of 0.001 to 10 mass% with respect to the polyamide.

  Moreover, the cross-sectional shape of the single fiber of the polyamide fiber of the present invention may be not only a round cross section but also a variety of irregular cross-sectional shapes such as flat, Y-type, T-type, hollow-type, and the cross-sectional shape shown in FIG. . The form of the fiber may be a multifilament or a monofilament.

  The polyamide fiber of the present invention has an elongation of 70 to 150%. If the elongation is low, the processable conditions when processing the obtained polyamide fiber are narrowed, and it becomes difficult to obtain added value for the resulting fiber. For example, in the case of false twisted yarn obtained by performing false twisting after drawing to make a thick part and a thin part, the range of conditions that can be drawn becomes narrow, so that the fineness difference between the thick part and the thin part is sufficiently large It becomes difficult to obtain. As a result, it is difficult to express the tone that is expected when a woven or knitted fabric is used. In addition, in the case of composite processed yarn obtained by interlacing using a part of low elongation yarn, it is difficult to obtain a sufficient difference in yarn length, and it is difficult to express a satisfactory texture when it is made into a woven or knitted fabric. . In addition, the fiber having an excessively large elongation has a large number of amorphous parts in the fiber structure, and at the time of winding the yarn, water enters a large amount of the amorphous part and is easily crystallized. As a result, the fiber length is increased during winding and is extended in the package, so that a phenomenon occurs in which the yarn layer in the winding package is displaced and ruptured, and it becomes difficult to stably wind. Moreover, the fiber with a too high elongation has more amorphous parts in the fiber structure. At the time of winding the yarn, water enters a large amount of the amorphous part and is easily crystallized. By stretching the fiber after winding, a phenomenon occurs in which the yarn layer in the winding package is displaced and ruptured, and it becomes difficult to wind the fiber stably. Furthermore, the fastness to washing in the final product using fibers with too high elongation decreases. As a result of considering such problems, the optimum elongation is 70 to 150%. More preferably, it is 80 to 150%.

  The polyamide fiber of the present invention preferably has a strength of 3.5 cN / dtex or more. By increasing the strength, it is possible to obtain an effect on the quality of the final product and the yarn forming property. If it is small, not only the high-order passability during yarn processing, weaving and knitting deteriorates, but it is difficult to obtain durability in the final product. Further preferred strength is 4.0 cN / dtex or more.

  The total fineness of the polyamide fiber of the present invention can be appropriately set depending on the application, but is preferably 10 to 230 dtex, and more preferably 10 to 200 dtex. Further, the single fiber fineness can be appropriately set depending on the application, but is preferably 0.5 to 10 dtex, more preferably 0.5 to 5 dtex from the viewpoint of softness when processed into a fabric.

  The polyamide fiber of the present invention is produced by general melt spinning as a basic spinning method, and the production process is not particularly limited as long as the polyamide fiber of the present invention is obtained. However, it can be produced by the following production method.

  A method in which molten polyamide is discharged from a die to form a yarn, the yarn is cooled and solidified with cooling air, a spinning oil is attached to the yarn, and then the yarn is taken up and further wound up. is there.

  The method will be specifically described with reference to FIG. FIG. 2 is a conceptual diagram showing an example of a fiber manufacturing process according to the present invention.

  The molten polyamide is measured by the gear pump 1, extruded, and discharged from the spinning nozzle 2, and the polyamide is used as a fibrous yarn. The yarn is cooled to near room temperature by blowing cooling air with a cooling device 3 such as chimney to solidify the polyamide yarn. The yarn is fed by the lubrication device 4 and converged. Then, the yarn is entangled by the entanglement nozzle device 5, taken up by the first godet roller 6, passed through the second godie roller 7, and taken up by the winding device 8.

  In the method for producing a polyamide fiber of the present invention, the distance from the outlet of the die to the oil for spinning is preferably 500 mm or more and 1500 mm or less. Preferably they are 500 mm or more and 1200 mm or less, More preferably, they are 500 mm or more and 1000 mm or less. When this distance is short, an oil agent will be adhered before completion | finish of draft drawing, and there exists a possibility of producing the strong elongation fall of the fiber obtained. When the distance is large, shrinkage due to excessive draft stretching occurs during winding, winding tightening occurs after winding, and the yarn drum cannot be pulled out, which tends to make stable production difficult.

  The polyamide used in the polyamide fiber of the present invention has a water absorption rate lower than the 1.8% water absorption rate of general polyamide 6 from the viewpoint of the ratio between the number of amide groups and the number of methylene groups. In general polyamide 6, the glass transition temperature becomes lower than room temperature due to moisture absorption before the oil is supplied by the oil supply device 4, and the polymer chain can move freely. Therefore, even if the yarn travels in the air, the increase in tension is small. However, the polyamide yarn of the present invention has a smaller drop in glass transition temperature than that of polyamide 6 and has a glass transition point of 25 ° C. or higher at room temperature where it is usually produced. Above the glass transition temperature, the polymer chain in the fiber cannot move, and the tension generated by the yarn running in the air is greatly increased. Therefore, even if the distance from the spinneret 2 to the oil supply device 4 to which the spinning oil is adhered is equal, the polyamide fiber of the present invention has a higher yarn tension. As a result, as the tension increases, the extension of the accompanying airflow applied to the first godet roller 6 increases, so that after winding on the drum, contraction occurs, and stable production tends to be difficult due to the occurrence of tightening. . Therefore, the polyamide fiber of the present invention can be obtained by shortening the distance from the spinneret 2 to the oil supply device 4 to which the spinning oil agent is adhered, and by reducing the increase in tension applied to the yarn above the glass transition temperature. . Further, since the polyamide of the present invention, for example, polyamide 610, has a higher Young's modulus compared to polyamide 6, there is a tendency that the tension of the yarn until it is discharged from the spinneret 2 and the oil agent is adhered is increased. As described above, since the stretching applied to the first godet roller 6 becomes a factor, also in this respect, it is possible to shorten the distance from the spinneret 2 to the oil supply device 4 to which the spinning oil is adhered in order to obtain polyamide fibers. It is desirable.

  For the above reasons, the distance from the spinneret to the outlet spinning oil is preferably 500 mm or more and 1200 mm or less, and more preferably 500 mm or more and 1000 mm or less.

  Further, the spinning oil applied by the oil supply device 4 is preferably a water-containing oil. When a water-containing oil agent is applied, the glass transition temperature of the polyamide decreases due to moisture contained in the oil agent in the middle of yarn production, leading to a decrease in yarn tension between the oil supply device 4 and the entanglement nozzle device 5. It is preferable because stretching between the oil supply device 4 and the entanglement nozzle device 5 is suppressed and tightening is reduced.

  Moreover, in the manufacturing method of the polyamide fiber of this invention, it is preferable that a taking-up speed | rate is the range of 3300 m / min or more and 4300 m / min or less. The winding speed is preferably 0.8 to 1.2 times the take-up speed. In the case of the manufacturing method shown in FIG. 2, the take-off speed means the peripheral speed of the first godet roller 6. The winding speed is the peripheral speed of the winding device 8.

  The take-off speed and the value obtained by dividing the take-up speed by the take-up speed represent the total stretch amount that serves as an index of the orientation of the polymer, and stable production can be achieved by setting this range. When the total drawing amount is too small, that is, when the take-up speed is low and the value obtained by dividing the take-up speed and the take-up speed is larger than 1.2 times, the degree of orientation of the fiber crystals is low, and the spinning oil or air As a result, the yarn swells and cannot be stably spun. If the total drawing amount is too large, that is, the take-up speed (circumferential speed of the first godet roller 6) exceeds 4300 m / min, or the value obtained by dividing the take-up speed and the take-up speed is less than 0.8 times, Orientation is too advanced and winding tightening occurs, preventing stable production. Preferably, the take-up speed is in the range of 3300 m / min to 4000 m / min, and the take-up speed is in the range of 0.8 to 1.2 times the take-up speed. More preferably, the take-up speed is 3300 m / min or more and 3800 m / min or less, and the take-up speed is 1.0 to 1.2 times the take-up speed.

  By setting the oil supply position, the take-up speed, and the take-up speed within such ranges, stable production can be achieved without causing swelling and tightening during spinning, and a good cheese-like package can be obtained.

  The cheese-like package made of the polyamide fiber of the present invention preferably has a bulge rate of 10% or less. The bulge rate indicates the degree of swelling of the package end surface, and the maximum width WB (mm) of the package and the width WS (mm) of the winding start of the package shown in FIG. 3 are measured, and {(WB−WS) / It is a numerical value calculated by WS} × 100. FIG. 3 is a package side cross-sectional view schematically showing the cheese-like package of the present invention according to the present invention, and shows a state where the yarn B is wound around the paper tube A. FIG.

  When the bulge rate exceeds 10%, when packing in a carton case or a pallet, there arises a problem that it is difficult to fix and pack in a predetermined place due to swelling of the end face of the package. Even if the packing is completed, there is a problem that the yarn is rubbed due to friction between the package end face and the packing material during the transportation (single yarn entanglement, single yarn breakage) or the yarn is unwound. More preferably, it is 8% or less.

  The cheese-like package made of the polyamide fiber of the present invention is particularly effective when the package is rolled up and the amount of fiber is 3 kg or more, and particularly effective when it is 4.5 kg or more. Although there is no restriction | limiting as an upper limit, Usually, 7.5 kg or less is used.

  The polyamide fiber of the present invention can be used alone for a fabric as it is, but is preferably used for a fabric through a processing yarn. Examples of the processing yarn include a false twisted yarn that imparts crimpability, and a drawn false twisted yarn and a fused false twisted yarn having a thick portion and a thin portion that express tone. Moreover, the composite yarn etc. which give the characteristic to a texture by mixing the polyamide fiber yarn of this invention and a low elongation fiber yarn and giving a yarn length difference are also mentioned. In the composite yarn, the low elongation fiber yarn preferably has an elongation of less than 70%, more preferably 30 to 50%. Further, in the case of composite processing such as composite processed yarn or composite false twisted yarn in which the polyamide fiber yarn of the present invention is combined with one or more other yarns, they may be combined with the same material or with different materials. Good. Moreover, the manufacturing method may process simultaneously, and may process after giving a process separately.

  The polyamide polyamide fiber of the present invention and the fiber structure (usually fabric) using the processed yarn from the polyamide fiber include sports casual wear such as shirts and blousons, pants, coats, men's and women's clothing, camisole, shorts, etc. It can be used for apparel such as leg wear such as innerwear, stockings and socks. It can also be used for clothing materials such as underwear cups and pads. It can also be used for interior applications such as curtains, carpets, mats, furniture, and other industrial materials.

  The present invention will be described in detail with reference to examples. In addition, the measuring method in an Example used the following method.

[Measuring method]
A. Sulfuric acid relative viscosity 0.25 g of a sample was dissolved in 100 ml of sulfuric acid having a concentration of 98% by mass so as to be 1 g, and the flow time (T1) at 25 ° C. was measured using an Ostwald viscometer. Subsequently, the flow time (T2) of only sulfuric acid having a concentration of 98% by mass was measured. The ratio of T1 to T2, that is, T1 / T2, was defined as sulfuric acid relative viscosity.

B. Intrinsic viscosity [IV]
Orthochlorophenol (hereinafter abbreviated as O C P) 10. 8 g was dissolved, and the relative viscosity [η r] was calculated by the following equation (I V) using an Ostwald viscometer at 25 ° C.
The relative viscosity [η r] = η / η 0 = (t × q) / (t 0 × q 0)
Intrinsic viscosity [IV] = 0. 0 2 4 2 η r + 0. 2 6 3 4
Where η: viscosity of polymer solution, η ₀ : viscosity of O CP, t: solution drop time (seconds), q: solution density (g / cm ³ ), t ₀ : drop time of OCP (Seconds), q ₀ : density of O CP (g / cm ³ ).

C. Melting point (Tm)
Using a differential scanning calorimeter DSC-7 manufactured by PerkinElmer, 20 mg of sample polymer is collected. As the first scan, the temperature is increased from 20 ° C. to 270 ° C. at a temperature increase rate of 20 ° C./min and held at a temperature of 270 ° C. for 5 minutes. Thereafter, the temperature is decreased from 270 ° C. to 20 ° C. at a temperature decrease rate of 20 ° C./min. After maintaining at a temperature of 20 ° C. for 1 minute, the temperature is further increased to 270 ° C. at 20 ° C. at a temperature increase rate of 20 ° C./min as a second scan. The temperature of the endothermic peak observed at that time was taken as the melting point.

D. Fineness Samples were prepared by winding 200 times with a measuring instrument with a frame circumference of 1.125 m, dried with a hot air dryer (105 ± 2 ° C. x 60 minutes), and weighed the weight of the waste with a balance (official moisture) The fineness was calculated from the value multiplied by rate + 1). The official moisture content was 4.5% for polyamide 6, 2.5% for polyamide 610, 3.0% for polyamide 510, and 1.2% for polyamide 12. The measurement was performed 4 times, and the average value was defined as the fineness. Moreover, the value which divided the obtained fineness by the number of filaments was made into the single fiber fineness.

E. Strength and Elongation Samples were measured under conditions of constant speed elongation as shown in JIS L1013 (Chemical Fiber Filament Yarn Test Method, 2010) by Orientec Co., Ltd. “TENSILON” (registered trademark), UCT-100. The elongation was determined from the elongation at the point showing the maximum strength in the tensile strength-elongation curve. Further, the strength was determined by dividing the maximum strength by the fineness. The measurement was performed 10 times, and the average values were taken as strength and elongation.

F. Boiling water shrinkage The obtained polyamide fiber was wound up 20 times with a skeiner with a circumference of 1.125 m to make a skein, and the initial length L ₀ was determined under a 0.09 cN / dtex load. Next, it is treated in boiling water under no load for 30 minutes and then air-dried. Next, a length LB after treatment under a 0.09 cN / dtex load is obtained and calculated by the following equation.
Boiling water shrinkage ratio (%) = [(L ₀ −L ₁ ) / L ₀ ] × 100
G. Tube knitted fabric thickness sense Five knitted fabrics were compared and evaluated for knitted fabric thickness sense based on the following evaluation criteria. In addition, the sample of the comparative example 8 was used for the comparison object.
Excellent: There is a sense of depth Good: There is a sense of depth Normal: No sense of depth (equivalent to Comparative Example 8)
Defect: No sense of ground thickness (thinner than Comparative Example 8)
H. Full Package Rate The full package rate obtained when spinning 1 ton was calculated by the following formula.
Full package rate (%) = [D ₁ / D ₀ ] × 100
D ₀ : theoretical maximum number of packages obtained when spinning 1 ton D ₁ : actual number of packages obtained when spinning 1 ton (Example 1)
Using polyamide 610 (sulfuric acid relative viscosity 2.67, melting point: 225 ° C.), melt spinning was continuously performed with a spinning device shown in FIG. 2 to obtain polyamide fibers. The process is as follows. First, polyamide 610 is put into a spinning machine, melted at a spinning temperature of 270 ° C., the polymer is weighed with a gear pump 1 (35.7 g / min), discharged, and discharged into a spinneret 2 heated to 270 ° C. Then, a spun yarn was obtained from the surface of the spinneret 2 having 68 holes of round holes having a discharge hole diameter of 0.20 mm and a hole length of 0.5 mm. The yarn was cooled with air using a uniflow type cooling device 3 and solidified, and then supplied by an oil supply device 4. The oiling device was installed at a position 800 mm from the surface of the spinneret. Entangling was applied by the entanglement nozzle device 5, the peripheral speed of the first godet roller 6 (that is, the take-up speed) was taken at 4094 m / min, and the peripheral speed of the second godie roller 7 was set to 4094 m / min. The draw ratio is 1.0. And winding-up speed | velocity | rate was 4000 m / min and the 6 kg cheese-like package which consists of nylon 610 fiber of 96 dtex 68 filaments was obtained. During spinning, there was no occurrence of swelling and tightening on the take-up drum, and production was extremely stable. A plurality of cheese-like packages were produced, and as a result, the full package rate was 100%. The evaluation results of the obtained fiber are shown in Table 1.

(Example 2)
A multifilament 6 kg cheese-like package was obtained under the same conditions as in Example 1 except that the position of the oiling device was set at a position 1200 mm from the surface of the spinneret. During spinning, production was extremely stable with no occurrence of swelling and tightening. The full package rate was 95%. The evaluation results of the obtained fiber are shown in Table 1.

(Example 3)
A multifilament 6 kg cheese-like package was obtained under the same conditions as in Example 1 except that the position of the oiling device was set at a position 1500 mm from the spinneret surface. During spinning, production was extremely stable with no occurrence of swelling and tightening. The full package rate was 90%. The evaluation results of the obtained fiber are shown in Table 1.

Example 4
The same conditions as in Example 1 except that the peripheral speed of the first godet roller 6 was 4264 m / min, the peripheral speed of the second godet roller 7 was 4264 m / min, the draw ratio was 1.0, and the winding speed was 4200 m / min. A 6 kg cheese-like package of multifilaments was obtained. During spinning, production was extremely stable with no occurrence of swelling and tightening. The full package rate was 100%. The evaluation results of the obtained fiber are shown in Table 1.

(Example 5)
The conditions were the same as in Example 1 except that the peripheral speed of the first godet roller 6 was 3839 m / min, the peripheral speed of the second godet roller 7 was 3839 m / min, the draw ratio was 1.0, and the winding speed was 3800 m / min. Thus, a 6 kg cheese-like package of multifilaments was obtained. During spinning, production was extremely stable with no occurrence of swelling and tightening. The full package rate was 100%. The evaluation results of the obtained fiber are shown in Table 1.

(Example 6)
The same conditions as in Example 1 except that the peripheral speed of the first godet roller 6 was 3722 m / min, the peripheral speed of the second godet roller 7 was 4094 m / min, the draw ratio was 1.1, and the winding speed was 4000 m / min. A multifilament, 6 kg cheese package was obtained. During spinning, production was extremely stable with no occurrence of swelling and tightening. The full package rate was 95%. The evaluation results of the obtained fiber are shown in Table 1.

(Example 7)
The conditions were the same as in Example 1 except that the peripheral speed of the first godet roller 6 was 3321 m / min, the peripheral speed of the second godet roller 7 was 3819 m / min, the draw ratio was 1.15, and the winding speed was 3800 m / min. Thus, a 6 kg cheese-like package of multifilaments was obtained. During spinning, production was extremely stable with no occurrence of swelling and tightening. The full package rate was 95%. Table 2 shows the evaluation results of the obtained fibers.

(Example 8)
The conditions were the same as in Example 1 except that the peripheral speed of the first godet roller 6 was 3327 m / min, the peripheral speed of the second godet roller 7 was 3660 m / min, the draw ratio was 1.05, and the winding speed was 3600 m / min. Thus, a 6 kg cheese-like package of multifilaments was obtained. During spinning, production was extremely stable with no occurrence of swelling and tightening. The full package rate was 95%. Table 2 shows the evaluation results of the obtained fibers.

Example 9
Except that the polymer was measured with the gear pump 1 (23.6 g / min), the discharge hole diameter was 0.30 mm, the round hole having a hole length of 0.75 mm and 24 holes were spun from the spinneret 2, the same as in Example 1. Under the conditions, two 6 kg cheese-like packages of multifilaments having a total fineness of 64 dtex and 24 filaments were obtained. During spinning, production was extremely stable with no occurrence of swelling and tightening. The full package rate was 100%. Table 2 shows the evaluation results of the obtained fibers.

(Example 10)
A total of 20 round holes with a discharge hole diameter of 0.20 mm and a hole length of 0.50 mm were spun from the spinneret 2 and the oiling device was installed at 1500 mm from the base surface under the same conditions as in Example 1. A 6 kg cheese-like package of multifilaments with a fineness of 96 dtex and 20 filaments was obtained. During spinning, production was extremely stable without occurrence of swelling and tightness. The package rate was 90%. The evaluation results of the obtained fiber are shown in Table 1.

(Example 11)
Except that the polymer was metered with the gear pump 1 (16.2 g / min), the hole diameter was 0.20 mm, the hole length was 0.50 mm, and 68 holes were spun from the spinneret 2. Under the conditions, two packages having a total fineness of 44 dtex, a multifilament of 34 filaments, and a 6 kg cheese package were obtained. During spinning, production was extremely stable with no occurrence of swelling and tightening. The full package rate was 100%. Table 2 shows the evaluation results of the obtained fibers.

(Example 12)
The same conditions as in Example 1 were used except that polyamide 12 (sulfuric acid relative viscosity 2.20, melting point: 180 ° C.) was melted at a spinning temperature of 250 ° C. and led to a spinneret 2 heated to 250 ° C. Thus, a 6 kg cheese-like package of multifilaments was obtained. During spinning, production was extremely stable with no occurrence of swelling and tightening. The full package rate was 100%. Table 2 shows the evaluation results of the obtained fibers.

(Example 13)
Using a polyamide 510 (melting point: 216 ° C.) with sulfuric acid relative viscosity 2.62, melted at 250 ° C. and led to the spinneret 2 heated to 250 ° C. A 6 kg cheese-like package of filaments was obtained. During spinning, production was extremely stable without the occurrence of tightening. The full package rate was 100%. Table 2 shows the evaluation results of the obtained fibers.

(Comparative Example 1)
When winding was performed under the same conditions as in Example 1 except that the position of the oiling device was set at a position 1800 mm from the spinneret surface, winding tightening occurred and the package could not be removed from the winding device. . Therefore, a multifilament cheese-like package could not be obtained, and stable production was impossible.

(Comparative Example 2)
When winding was attempted under the same conditions as in Example 1 except that the position of the oiling device was set at a position 300 mm from the spinneret surface, the yarn tension from the adhering oil to the entanglement nozzle device 5 was reached. And the winding of the yarn around the first godet roller 6 occurred frequently. Therefore, a multifilament cheese-like package could not be obtained, and stable production was impossible.

(Comparative Example 3)
Under the same conditions as in Example 1, except that the peripheral speed of the first godet roller 6 was 4592 m / min, the peripheral speed of the second godet roller 7 was 4592 m / min, the draw ratio was 1.0, and the winding speed was 4500 m / min. A multifilament, cheese-like package was obtained. Winding frequently occurred during spinning. It was possible to remove the package from the winding device, and a multifilament, 6 kg cheese package was obtained. The full package rate was 40%, and stable production was impossible. The obtained multifilament had an elongation of 63% and a strength of 4.9 cN / dtex, and no high elongation was exhibited. Moreover, the bulge rate of the obtained cheese-like package was 12.0%, and could not be fixed and packed in a predetermined place of a carton case or a pallet.

(Comparative Example 4)
Under the same conditions as in Example 1, except that the peripheral speed of the first godet roller 6 was 3108 m / min, the peripheral speed of the second godet roller 7 was 4040 m / min, the draw ratio was 1.3, and the winding speed was 4000 m / min. A multifilament was obtained. Winding frequently occurred during spinning. It was possible to extract the package from the winding device, and a 6 kg cheese-like package of multifilament was obtained. The full package rate was 50%, and stable production was impossible. Moreover, the elongation of the obtained fiber was 60%, the strength was 5.2 cN / dtex, and no high elongation was exhibited. Moreover, the bulge rate of the obtained cheese-like package was 12.5%, and could not be fixed and packed in a predetermined place of a carton case or a pallet.

(Comparative Example 5)
Except for using polyamide 6 (sulfuric acid relative viscosity 2.62, melting point: 220 ° C., number of methylene groups 1: 5), when winding was attempted under the same conditions as in Example 1, swelling of the fiber due to moisture absorption was observed. As a result, the yarn layer was displaced in the winding package, and a multifilament and cheese-like package could not be obtained, and stable production was impossible.

  From the results of Examples 1 to 13 described in Table 1 and Table 2 and Comparative Examples 1 to 5 above, according to the invention of the method for producing polyamide fibers, extremely stable production without occurrence of swelling and tightening during spinning It is understood that is possible.

(Examples 14 to 16)
Polytrimethylene terephthalate with an intrinsic viscosity [IV] of 1.40 and polyethylene terephthalate with an intrinsic viscosity [IV] of 0.51 are melted at a weight ratio of 50:50 at a spinning temperature of 275 ° C., introduced into a spinning pack and melted. Discharged. After cooling the discharged yarn, it is taken up by a take-up roller heated to 55 ° C. at 1200 m / min, drawn to a draw roller heated to 155 ° C. at 4200 m / min, stretched and heat-treated, and subsequently fluidized by an entanglement applying device. A confounding process was performed. Then, after taking up with a non-heated third roller at a stretch rate of -4.5% (speed 4011 m / min), taking up with a non-heated fourth roller at 4011 m / min, winding with a winder, A cheese-like package composed of 33 dtex 12 filament polyester composite multifilament was obtained.

Polyamide 610 multifilaments of 96 dtex 68 filaments obtained in Example 1, Example 5 and Example 9 were prepared as sheath yarns. A 33 dtex 12 filament polyester composite multifilament (fineness 33 dtex, elongation 34%, strength 3.7 cN / dtex) attached to the cheese-like package shown above was prepared as a core yarn. Using a composite false twisting machine (manufactured by Aiki Seisakusho: TH) shown in FIG. 4, composite processing yarn of 129 dtex 88 filaments was obtained using composite processing using the sheath yarn and core yarn.
This specific method will be described with reference to FIG. First, the sheath yarn was supplied from the sheath yarn package 10 through the sheath yarn feed roller 11. This yarn was introduced into the false twist heater 13 while being false twisted by the twister 12 below, and the sheath yarn was taken up by the take-up roller 15 for the sheath yarn and further supplied to the nozzle 16. It was done. On the other hand, the polyamide fiber was taken up from the core yarn package 9 by the core yarn take-up roller 14 and supplied to the nozzle 16. The sheath yarn and core yarn fibers supplied to the nozzle 16 were entangled by the nozzle 16. The entangled yarn became a processed yarn and was wound around a winding device 18 via a take-up roller 17. Thus, a composite processed yarn 19 was obtained.

  Regarding specific processing conditions, the processing speed was 250 m / min, the false twist ratio was 1.22 times, the heater temperature was 190 ° C., the D / Y ratio was 1.6 times, and the twister was a triaxial type.

When the composite processed yarn is observed, the polyester composite multifilament forming the core is located in the center of the composite processed yarn, whereas the polyamide 610 multifilament forming the sheath is polyester-based. The composite multifilament had a yarn length difference. The composite processed yarn was placed in a flat state in a free state, and the difference in yarn length was observed. When the yarns of Example 7, Example 5, and Example 1 were compared, Example 7 had the highest yarn length difference and Example 1 had the lowest. When the cylindrical knitted fabric of the obtained composite processed yarn was prepared and the texture was evaluated, the difference in yarn length was increased and the sense of ground thickness was increased. The evaluation results are shown in Table 3.

(Examples 17 to 18)
The polyester fiber is the same as in Example 14 except that the 96 dtex 68 filament polyamide 12 multifilament obtained in Example 12 and the 96 dtex 68 filament polyamide 510 multifilament obtained in Example 13 are used as the sheath yarn. Composite processing was performed to obtain a composite temporary working yarn of 129 dtex 88 filaments. A cylindrical knitted fabric was prepared in the same manner as in Example 14 using the obtained composite processed yarn. The evaluation results are shown in Table 3.

(Comparative Example 7)
The composite processing was carried out in the same manner as in Example 14 using the 96 dtex 68 filament polyamide 610 multifilament obtained in Comparative Example 4 as a sheath yarn to obtain a composite temporary working yarn of 129 dtex 88 filament. A cylindrical knitted fabric was prepared in the same manner as in Example 14 using the obtained composite processed yarn. The evaluation results are shown in Table 3.

(Comparative Example 8)
Using polyamide 6 (sulfuric acid relative viscosity 2.62, melting point: 220 ° C., methylene group number 1: 5), the peripheral speed of the first godet roller 6 is taken at 4545 m / min, the peripheral speed of the second godet roller 7 is 4545 m / min, Winding was performed at a draw ratio of 1.0 and a winding speed of 4500 m / min to obtain a polyamide 6 multifilament of 96 dtex 68 filaments. The fineness was 96.0 dtex, the elongation was 60%, and the strength was 4.5 cN / dtex.

  The obtained 96-decitex 68 filament polyamide 6 multifilament was used as a sheath yarn to perform composite processing in the same manner as in Example 14 to obtain a composite temporary working yarn of 129 decitex 88 filament. A cylindrical knitted fabric was prepared in the same manner as in Example 14 using the obtained composite processed yarn. The evaluation results are shown in Table 3.

  From the results in Table 3, it can be seen that by using the polyamide fiber of the present invention, a knitted fabric with a good sense of ground thickness can be obtained.

1: Gear pump 2: Spinneret 3: Cooling device 4: Oil supply device 5: Entangling nozzle device 6: First godie roller 7: Second godie roller 8: Winding device A: Paper tube B: Yarn 9: Core yarn package 10: Sheath yarn package 11: Sheath yarn feed roller 12: False twisting heater 13: Twister 14: Core yarn feed roller 15: Sheath yarn take-up roller 16: Nozzle 17: Take-up roller 18: Winding device 19: Composite yarn

Claims (7)

A polyamide fiber having a strength of 3.5 cN / dtex or more and an elongation of 70 to 150% having a polyamide which is a polymer of the structural formula A shown below or a polyamide which is a polymer of the structural formula B.

In Structural Formula A, l is 9 to 12,
In Structural Formula B, (m + n) / 2 is 6-12. The polyamide fiber according to claim 1, wherein the polyamide is a polymer of the structural formula B. The polyamide fiber according to claim 1, wherein the polyamide is a polymer of the structural formula A. A cheese-like package comprising the polyamide fiber according to any one of claims 1 to 3 and having a bulge ratio represented by the following formula (I) of 10% or less.
B (%) = {(WB−WS) / WS} × 100 (I)
(B: bulge rate, WB: maximum package width (mm), WS: width at the start of package winding (mm)). The molten polyamide is discharged from the die to form a yarn, the yarn is cooled and solidified with cooling air, a spinning oil is attached to the yarn, and then the yarn is taken up and further wound up. The manufacturing method of the polyamide fiber according to any one of claims 1 to 3, wherein the manufacturing method is characterized by satisfying the following (a) and (b).
(A) The distance from the outlet of the die to the oil for spinning is 500 mm or more and 1500 mm or less (b) The take-up speed is 3300 m / min or more and 4300 m / min or less, and the take-up speed is 0.8 to 1. Double A composite processed yarn comprising the polyamide fiber according to any one of claims 1 to 3 and a fiber having an elongation of less than 70%. The fabric containing the polyamide fiber in any one of Claims 1-3.

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