JP2021085122A - Polyamide fibers, and lace and knit fabric using the same - Google Patents

Abstract

To provide polyamide fibers for obtaining: a lace with excellent practical durability and excellent aesthetics that makes a pattern look beautiful due to difference in shade between a ground thread and a pattern thread; and woven knitted fabrics having excellent aesthetics.SOLUTION: There are provided polyamide fibers in which an amount of an amino-terminal group is 2.0×10-5 mol/g or less, and a strong elongation product is 7.5 cN/dtex or more.SELECTED DRAWING: None

Description

The present invention relates to a polyamide fiber that exhibits a difference in shade during dyeing and has excellent mechanical properties.

Polyamide fibers such as polycoupledide and polyhexamethylene adipamide are excellent in mechanical properties, chemical resistance, and heat resistance, and are therefore widely used in clothing applications and industrial material applications. In particular, it is used in many clothing applications due to its excellent strength and soft texture, color development during dyeing, abrasion resistance, and the like.

In recent years, with the sophistication and diversification of fashion, the demand for highly aesthetic lace and woven and knitted fabrics has been increasing in innerwear and outerwear applications. In lace, there is an increasing demand for fabrics that make the ground thread inconspicuous and emphasize the pattern thread for the purpose of making the pattern look beautiful. For example, Patent Document 1 proposes a method of improving the transparency of a ground yarn by using a high-strength polyamide multifilament having a high-strength elongation product and an appropriate fiber modulus.

In woven and knitted fabrics, polyamide fibers have been proposed in which so-called dyeing is performed by making a difference in shade and color for each of the constituent fibers to improve the aesthetics. For example, Patent Document 2 proposes a polyamide fiber containing a pigment. As an example thereof, a polyamide fiber containing a pigment and a polyamide fiber containing no pigment are used for the warp and weft of a woven fabric, respectively, and have aesthetic properties. Technology has been proposed. Further, Patent Document 3 proposes a cationic dyeable polyamide fiber, which is interwoven with a conventional polyamide fiber by warp and weft, and dyed separately with an acid dye and a cationic dye to obtain a fabric having a chambray feeling. It is proposed to provide.

International Publication No. 2018/021011 Pamphlet JP-A-2017-155348 Japanese Unexamined Patent Publication No. 2015-67723

However, in the use of the polyamide fiber exemplified in Patent Document 1, although the transparency of the lace ground yarn is improved, it is necessary to set restrictions on the variation of the pattern in order to secure the practical durability of the lace. In other words, in a lace structure with a low density of ground yarn, it is necessary to increase the fineness of the ground yarn in order to ensure practical durability, but the effect of emphasizing the handle is reduced, so the effect is limited. Met.

Although the use of the polyamide fiber exemplified in Patent Document 2 enables the fibers to be dyed separately, the color tone of one of the polyamide fibers is fixed to the color tone of the polyamide fiber containing a pigment (for example, black original coating). However, there is a problem that there are many restrictions on the expansion of color variations of inner wear and outer wear, which have been diversified in recent years. Further, the strength of the obtained fiber is 4.3 to 4.9 cN / dtex, and the strength decrease due to the pigment content is unavoidable, the strength is not satisfactory, and the practical durability of the race is inferior. It was.

In the use of the polyamide fiber exemplified in Patent Document 3, the fiber can be dyed in any two colors by performing anion dyeing with an acid dye and cation dyeing with a basic dye, but the obtained fiber can be dyed separately. The strength was 3.3 to 5.5 cN / dtex, the strength was not satisfactory, and the practical durability of the race was inferior. On the other hand, since the dyes are dyed with different dye types, there is a problem that there are many restrictions on the combination of dyes in which the ground yarn is thin and the pattern yarn is dyed deeply to emphasize the pattern yarn.

Therefore, it is an object of the present invention to provide a polyamide fiber which is excellent in practical durability, has a beautiful pattern by dyeing different shades, and can realize a lace with various color variations.

The above problem can be solved by the following configuration.
(1) A polyamide fiber having an amino-terminal group amount of 2.0 × ^10-5 mol / g or less and a strong elongation product of 7.5 cN / dtex or more.
(2) The polyamide fiber according to (1), which has a total fineness of 5 to 100 dtex.
(3) The polyamide fiber according to (1) or (2), which contains titanium oxide in the range of 0.5 to 3.0 wt%.
(4) The lace made of the polyamide fiber according to any one of (1) to (3).
(5) A woven or knitted fabric made of the polyamide fiber according to any one of (1) to (3).

INDUSTRIAL APPLICABILITY The present invention provides a polyamide fiber having excellent practical durability and enabling the realization of an aesthetically pleasing lace in which the pattern looks beautiful due to the difference in shade between the ground yarn and the pattern yarn, and a woven or knitted fabric having excellent aesthetics. be able to.

It shows one embodiment of the manufacturing apparatus which can be preferably used in the manufacturing method of the polyamide fiber of this invention.

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

The polyamide of the present invention is a resin composed of a high molecular weight material in which so-called hydrocarbon groups are linked to the main chain via an amide bond, and the polyamide is excellent in yarn-forming property and mechanical properties, and is mainly polycaproamide. (Nylon 6) and polyhexamethylene adipamide (nylon 66) are preferable, and polycaproamide (nylon 6) is more preferable because it is difficult to gel and has good yarn-forming property. Mainly in the above, 80 mol% or more of each of polycaprolamide is used as the ε-caprolactam unit constituting the polycaprolamide, and polyhexamethylene adipamide is used as the hexamethylene diammonium adipate unit constituting the polyhexamethylene adipamide. It means that it is more preferably 90 mol% or more.

The polyamide fiber in the present invention has an amino-terminal group amount of 2.0 × ^10-5 mol / g or less, more preferably 1.8 × ^10-5 mol / g or less, and further preferably 1.5 × 10 ^{−. It is 5} mol / g or less. By setting this range, the light dyeing effect at the time of dyeing becomes large, and the dyeing difference from general-purpose polyamide fibers becomes large, so that the pattern yarn shines due to the light and shade difference, and a lace rich in aesthetics can be obtained. It will be possible. Further, the same effect can be obtained in woven and knitted fabrics. If it exceeds 2.0 × ^10-5 mol / g, the dyeing difference with the general-purpose polyamide fiber becomes small, so that the pattern yarn does not shine and aesthetics cannot be obtained. Further, the smaller the amount of amino-terminal groups is, the more preferable it is from the viewpoint of aesthetics, but the lower limit value in the present invention is ^{about 1.0 × 10-5} mol / g.

The polyamide fiber of the present invention has various additives such as a matting agent, a flame retardant, an antioxidant, an ultraviolet absorber, an infrared absorber, a crystal nucleating agent, a fluorescent whitening agent, an antistatic agent, and a hygroscopic agent ( (Polyvinylpyrrolidone, etc.), antibacterial agent (silver zeolite, zinc oxide, etc.) and the like may be added as needed between 0.001 to 10 wt% in the entire polyamide fiber. Above all, as a matting agent, it is preferable that the entire fiber contains 0.5 to 3.0 wt% of titanium oxide, and more preferably 0.9 to 2.5 wt%. Titanium oxide is known as an excellent white pigment and is widely used in synthetic fibers as a matting agent. Because of the white pigment, when it is contained in the fiber, the appearance of the clothing becomes whitish, the light dyeing effect of the present invention can be easily obtained, and a polyamide fiber having excellent aesthetics can be obtained.

The polyamide fiber of the present invention has a strong elongation product of 7.5 cN / dtex or more represented by the following formula. It is more preferably 8.0 cN / dtex or more, and further preferably 8.5 cN / dtex or more. In the region of fineness of 5 to 100 dtex required for polyamide fibers used for lace yarn, the strong elongation product of polyamide fibers is extremely important in order to ensure the practical durability of the product, and is within this range. This makes it possible to obtain a fabric having excellent practical durability as inner wear or outer wear. When the strong elongation product is less than 7.5 cN / dtex, practical durability cannot be obtained when used as a lace ground yarn. Further, the larger the strength-elongation product is, the more preferable it is, but the upper limit value thereof in the present invention is about 9.5 cN / dtex.
Strong elongation product = strength (cN / dtex) × {(elongation (%) + 100) / 100}.

The elongation of the polyamide fiber of the present invention is preferably 35 to 50%, more preferably 38 to 47%. When the elongation is 35% or more, the process passability at the time of lace knitting is improved. By setting the elongation to 50% or less, dyeing fastness suitable for clothing applications can be obtained.

The strength of the polyamide fiber of the present invention is preferably 5.0 cN / dtex or more. By setting the strength to 5.0 cN / dtex or more, the cross-sectional shape of the polyamide fiber of the present invention, which provides practical durability when laced and improves process passability during lace knitting, is particularly high. Although not specified, circular, triangular, flat, lens type (flat convex type), beans type (flat concave type), Y type, cross shape, and star shape are preferably used.

The total fineness of the polyamide fiber of the present invention is preferably 5 to 100 dtex, and a more preferable range is 7 to 80 dtex. When the total fineness is 5 dtex or more, practical durability as inner wear or outer wear can be guaranteed, and when it is 100 dtex or less, a fabric having excellent softness and aesthetics can be obtained. The single yarn fineness is not particularly limited, but may be any commonly used single yarn fineness, and is preferably 5.0 dtex or less. In particular, from the viewpoint of softness and comfort, it is more preferably 4.0 dtex or less.

Next, the method for producing the polyamide fiber of the present invention will be described.

The method for producing the polyamide polymer used for the polyamide fiber of the present invention is not particularly limited, and a known production method can be used.

The amount of amino-terminal groups of the polyamide polymer is 2.0 × ^10-5 mol / g or less, and the relative viscosity of 98% sulfuric acid is 2.0 to 3.8. Generally, when the polymerization reaction of the polyamide polymer is advanced, the amount of amino-terminal groups decreases, but the molecular weight of the polymer increases and the viscosity of the polyamide polymer increases. In equipment that produces products with a fineness of 5 to 100 dtex, which is required for polyamide fibers for clothing, the threads discharged from the base are rapidly cooled. Therefore, if the viscosity of the polyamide polymer is too high, a high molecular weight polymer is sufficient. It is not possible to obtain a practical strength and strong elongation product of the polyamide fiber because it is not possible to obtain the time to orient the polyamide fiber. On the other hand, if the viscosity of the polyamide polymer is too low, the molecular weight is too small, and sufficient strength and strong elongation product of the polyamide fiber cannot be obtained. The method for setting the amount and viscosity of the amino terminal group of the polyamide polymer to the desired values is not particularly limited, but a method of adding a terminal group adjusting agent such as a carboxylic acid or melt mixing with an extruder or the like can be used. Examples thereof include a method of adding an end-blocking agent and a method of adjusting the amount of carbo-terminal groups and adjusting the amount of amino-terminal groups by adding a copolymerization component such as a dicarboxylic acid at the time of polymerization.

Further, in the polyamide in the present invention, the second and third components may be copolymerized or mixed in addition to the main component. The copolymerization component is not particularly limited, and may include, for example, a structural unit derived from an aliphatic dicarboxylic acid, an alicyclic dicarboxylic acid, an aromatic dicarboxylic acid, an aliphatic diamine, an alicyclic diamine, or an aromatic diamine. However, for example, the amount of amino-terminal groups of the polymer is adjusted by copolymerizing sodium 3,5-dicarboxybenzenesulfonate as an agent for adjusting the amount of amino-terminal groups, and the polyamide of the present invention, which has been difficult to adjust in the past. ^{It is possible to achieve both 2.0 × 10-5} mol / g or less, which is the amount of amino terminal groups required for the fiber, and the relative viscosity of 98% sulfuric acid of 2.0 to 3.8.

The polyamide fiber of the present invention can be produced by a known melt spinning apparatus. FIG. 1 shows an embodiment of a manufacturing apparatus preferably used in the method for manufacturing a polyamide fiber of the present invention. In the polyamide fiber of the present invention, in order to have a strong elongation product of 7.5 cN / or more, a polyamide polymer satisfying the above-mentioned amino terminal group amount range and sulfuric acid relative viscosity range is melted, and the polyamide polymer is weighed and transported by a gear pump. Then, it is finally extruded from the discharge hole provided in the spinneret 1 to form each filament. As shown in FIG. 1, each filament discharged from the spinneret 1 is surrounded by a gas supply device 2 that blows out steam in order to suppress stains on the spinneret over time, and around the entire circumference for slow cooling. A multi-layered heating cylinder 3 is provided in the above, and the yarn is cooled and solidified to room temperature by the cooling device 4. After that, the oil supply device 5 applies an oil agent and each filament is focused to form a multifilament, which is entangled by the fluid entanglement nozzle device 6 and passes through the take-up roller 7 and the draw roller 8, and at that time, the take-up roller 7 and the draw roller 8 are used. Stretch according to the ratio of peripheral speeds. Further, the yarn is heat-treated by heating the drawing roller 7 and wound by the winding device 9.

At this time, by setting the melting temperature at the time of melt spinning to 60 ° C. or higher with respect to the melting point of the polyamide polymer, the fluidity of the polyamide polymer at the time of melting is improved, and the orientation of the polyamide polymer at the time of ejection from the mouthpiece is relaxed. Since it is promoted, appropriate orientation and crystallization proceed during stretching, and a strong elongation product of 7.5 cN / dtex or more can be obtained. A more preferable melting temperature is 65 ° C. or higher with respect to the melting point of the polyamide polymer.

The polyamide polymer used for conventional general polyamide fibers has a strong elongation due to viscosity unevenness in the longitudinal direction of the polyamide fiber and mixing of gelled material because the viscosity of the polyamide polymer increases at the time of melting and gelation progresses. Since the product decreases, the melting temperature during melt spinning needs to be 40 ° C or higher and lower than 60 ° C with respect to the melting point of the polyamide polymer. By doing so, the melting temperature can be set high, and fibers having high strength and high elongation product can be obtained.

In the production of the polyamide fiber of the present invention, it is preferable that a heating cylinder 3 is provided above the cooling device 4 so as to surround each filament all around. By installing the heating cylinder 3 above the cooling device 4 and setting the ambient temperature in the heating cylinder to 200 ° C. or higher, the polyamide polymer discharged from the spinneret 1 has less thermal deterioration and can be relaxed in orientation. Polyamide fibers with high strength and high elongation product can be obtained by relaxing the orientation by slow cooling from the base surface to cooling.

In the production of the polyamide fiber of the present invention, it is more preferable that the heating cylinder has multiple layers. In the fineness region for clothing such as the polyamide fiber of the present invention, if the temperature distribution in the heating cylinder is constant, the heat convection tends to be disturbed, which affects the solidified state of each filament and U%. It becomes a factor that worsens. Therefore, by making the heating cylinder multi-layered and gradually lowering the temperature setting from the upper layer to the lower layer, heat convection from the upper layer to the lower layer is intentionally created, and the downdraft is made in the same direction as the accompanying flow of the yarn. , The turbulence of heat convection in the heating cylinder is suppressed, the yarn sway is small, and a fiber having a small U% can be obtained.

In the production of the polyamide fiber of the present invention, the cooling device 4 is a cooling device that blows cooling rectifying air from a certain direction, an annular cooling device that blows cooling rectifying air from the outer peripheral side toward the center side, or an annular cooling device that blows cooling rectifying air from the center side toward the outer periphery. It can be manufactured by any method such as an annular cooling device that blows cooling rectified air. The vertical distance LS (hereinafter referred to as the cooling start distance LS) from the lower surface of the spinneret to the upper end of the cooling air blowing portion of the cooling device 4 should be in the range of 100 to 200 mm to suppress yarn sway and U%. It is preferable in that it does. Regarding the cooling air velocity blown out from the cooling air blowing surface, the strength, strong elongation product, and the average of the sections from the upper end surface to the lower end surface of the cooling blowing portion should be in the range of 20.0 to 40.0 m / min. It is preferable in terms of U% and.

After that, it passes through the take-up roller 7 and the draw roller 8, and at that time, it is drawn according to the ratio of the peripheral speeds of the take-up roller 7 and the draw roller 8. Further, the yarn is heat-treated by heating the drawing roller 7 and wound by the winding device 9. The preferred take-up roller speed is 1500-3000 m / min, the preferred draw ratio (ratio of the peripheral speeds of the take-up roller 7 and the draw roller 8) is 1.4 to 4.0 times, and the preferred take-up speed is 2000-4500 m / min. It can be manufactured under the conditions.

Laces and woven and knitted fabrics using at least a part of the polyamide fiber of the present invention can be produced by a conventional method.

The lace may be a normal knitting structure such as an embroidered lace, a Russell lace, or a river lace, and a known method can be used for dyeing after knitting, subsequent post-processing, and final set conditions. For example, by using the polyamide fiber of the present invention for the lace ground yarn and using the polyamide fiber having an amino terminal group amount of 4.0 × 10 ^-5 mol / g or more as a part of the pattern yarn, the ground yarn is used after dyeing. On the other hand, the pattern thread is dyed in a dark color, the pattern part is emphasized, and a lace with excellent aesthetics that makes the pattern look beautiful can be obtained.

There are various types of woven fabrics such as shuttle looms, air jet room looms, water jet room looms, rapier looms, and gripper shuttle looms, but any looms may be used for manufacturing. There are several weave structures such as plain weave, twill weave, and satin weave, depending on how the weft is driven, but any of them can be selected according to the purpose. The knitting machine may be manufactured by any knitting machine such as a flat knitting machine, a circular knitting machine, or a warp knitting machine. In the case of (double-sided knitting) and warp knitting, there are several knitting organizations such as atlas organization, denby organization, and code organization, but any of them can be selected according to the purpose. For example, by combining the polyamide fiber of the present invention and the polyamide fiber having an amino-terminal group amount of 4.0 × 10 ^-5 mol / g or more and interweaving or knitting, a light and shade pattern is obtained after dyeing, and the aesthetics are rich. It is possible to manufacture woven and knitted fabrics. Further, by weaving and knitting using the polyamide fiber of the present invention and a mixed fiber yarn containing a polyamide fiber having an amino-terminal group amount of 4.0 × 10 ^-5 mol / g or more, the aesthetic appearance is emphasized. It is possible to manufacture a wide variety of woven and knitted fabrics.

Hereinafter, the present invention will be described in more detail with reference to Examples.

A. Sulfuric acid relative viscosity tip or fiber sample 0.25 g was dissolved in 100 ml of sulfuric acid having a concentration of 98 wt% 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 sulfuric acid alone having a concentration of 98 wt% was measured. The ratio of T1 to T2, that is, T1 / T2, was defined as the relative viscosity of sulfuric acid.

B. The total fineness fiber sample is wound 200 times with a measuring machine with a frame circumference of 1.125 m, dried with a hot air dryer (105 ± 2 ° C x 60 minutes), and then weighed with a balance to obtain the official moisture content. The fineness was calculated from the value multiplied by the rate. The measurement was performed 4 times, and the average value was taken as the fineness. Further, the value obtained by dividing the obtained total fineness by the number of filaments was defined as the single yarn fineness.

C. Strength, Elongation, Strength Elongation Product JIS L1013 (2010) Measure fiber samples according to tensile strength and elongation, and draw a tensile strength-elongation curve. As the test conditions, the type of testing machine was a constant speed extension type, a grip interval of 50 cm, and a tensile speed of 50 cm / min. When the tensile strength at the time of cutting was smaller than the maximum strength, the maximum tensile strength and the elongation at that time were measured.
The strength and strength product were calculated by the following formulas.
Elongation = Elongation at the time of cutting (%)
Strength = Tensile strength at cutting (cN) / Fineness (dtex)
Strong elongation product = strength (cN / dtex) × {(elongation (%) + 100) / 100}.

D. 1 g of the chip or fiber sample that has been subjected to the amino terminal group amount drying treatment is precisely weighed, dissolved in 25 ml of a phenol / ethanol mixed solvent (83.5: 16.5, volume ratio), and then medium using a 0.02N hydrochloric acid aqueous solution. The amount of amino terminal groups was measured from the titration at the time of Japanese titration. The amino terminal group amount value in the present specification is ^{represented by × 10-5} mol / g.

E. Titanium oxide content The crucible is air-baked in an electric furnace at 800 ° C., cooled, and then precisely weighed (A1). An absolutely dry fiber sample is weighed in this crucible (S), and the sample is carbonized while being heated in an electric furnace. Next, the crucible is baked in an electric furnace at 800 ° C. until it reaches a constant temperature, and then cooled and weighed (A2). From the results measured in this way, the titanium oxide content was determined by the method shown below.
Titanium oxide content (wt%) = (A2-A1) / S × 100.

F. Race evaluation (a) Durability Regarding the burst strength of race products, the burst strength at any three locations was measured according to the burst strength test method by JIS L1096 (2010) and the Mullen method (A method), and the average thereof. Based on the values, the evaluation was made on a 4-point scale based on the following criteria.
⊚: 150 kPa or more ◯: 120 kPa or more and less than 150 kPa Δ: 110 kPa or more and less than 120 kPa ×: less than 110 kPa ⊚, ◯, Δ were considered to have passed the durability.
(B) Quality (the appearance of the pattern)
With respect to the lace product, the degree of the appearance of the pattern was relatively evaluated based on the lace product manufactured by the same method as in Example 1 by the sensory evaluation of the inspectors (5 persons) having abundant evaluation experience. As a result, the average value of the evaluation points of each inspector was taken and rounded off to the nearest whole number, and the average value was 5 for ⊚, 4 for ◯, 3 for Δ, and 1-2 for x.
5 points: Very good 4 points: Somewhat excellent 3 points: Normal 2 points: Somewhat inferior 1 point: Inferior ◎, ○, △ were evaluated as passing grades.

[Example 1]
(Manufacture of polyamide fiber for lace yarn)
As a polyamide, a nylon 6 chip having an amino-terminal group content of 1.4 × ^10-5 mol / g, a sulfuric acid relative viscosity (ηr) of 2.50, a titanium oxide content of 2.0 wt%, and a melting point of 215 ° C. is used as a water content. It was dried by a conventional method so as to have a concentration of 0.05% by mass. The obtained nylon 6 chips were melted at a spinning temperature (melting temperature) of 285 ° C. and discharged from a spinneret. As the spinneret, a spinneret having 12 holes, a round shape, and a hole diameter of φ0.25 mm was used. The spinning machine was spun using the spinning machine of the embodiment shown in FIG.

After passing the yarn discharged from the spinneret 1 through the inside of the heating cylinder 3 having a length of 50 mm and a temperature of 290 ° C. installed directly under the spinneret, the cooling start distance is LS150 mm, the air temperature is 18 ° C., and the wind speed is high. It was cooled and solidified by the thread cooling device 4 at 35 m / min. After that, the refueling device 5 installed at a position 1600 mm below the mouthpiece converges the threads and applies an oil agent, and the fluid entanglement nozzle device 6 performs entanglement processing, and then the take-up roller 7 takes over at 2060 m / min. While stretching between the drawing roller 8 and the drawing roller 8 at 4,120 m / min, the heat was set at 165 ° C. (the temperature of the stretching roller 8), and the fiber was wound by the winding device 9 at 4000 m / min to obtain 33 dtex, 12 filament polyamide fibers. Obtained. The results of evaluation of the obtained polyamide fibers are shown in Table 1. The obtained polyamide fiber was used as a lace ground yarn.

(Manufacturing of polyamide fiber for lace pattern yarn)
As a polyamide, a nylon 6 chip having an amino-terminal group content of 5.5 × ^10-5 mol / g, a sulfuric acid relative viscosity (ηr) of 2.50, a titanium oxide content of 0.3 wt%, and a melting point of 215 ° C. is used as a water content. It was dried by a conventional method so as to have a concentration of 0.05% by mass. The obtained nylon 6 chips were melted at a spinning temperature (melting temperature) of 260 ° C. and discharged from a spinneret. As the spinneret, a spinneret having 68 holes, a round shape, and a hole diameter of φ0.20 mm was used. Other than that, 155 dtex, 68 filament polyamide fibers were obtained in the same manner as the polyamide fibers for lace ground yarn.

(Manufacturing of lace)
33dtex, 12-filament polyamide fiber for lace ground yarn is warped, and the runner length is 21.0cm as the back side yarn of 28G Russell lace ground yarn, and the runner length is 100.0cm, 155dtex as the front side yarn of the ground yarn. , 68 filaments knitted with polyamide fibers for lace pattern yarn.

Next, after refining the obtained raw machine, it was dyed at 90 ° C. for 60 minutes with the following acid dyes and auxiliaries, and finished set to obtain an inner lace product. Table 1 shows the evaluation results of the obtained race products.
Dyeing aid: Acetic acid: 0.15 g / L
Acid dye: Xylene Fast Blue P: 0.55% owf.

[Example 2]
Regarding the polyamide fiber for lace ground yarn, lace is carried out in the same manner as in Example 1 except that the amount of amino terminal groups of the nylon 6 chip is 1.6 × ^10-5 mol / g and the relative viscosity of sulfuric acid (ηr) is 2.53. Polyamide fibers for ground yarn and lace pattern yarn were spun to obtain lace products for inner yarn. The evaluation results of the obtained race products are shown in Table 1.

[Example 3]
Regarding the polyamide fiber for lace ground yarn, the lace is the same as in Example 1 except that the amount of amino terminal groups of the nylon 6 chip is 1.8 × ^10-5 mol / g and the relative viscosity of sulfuric acid (ηr) is 2.55. Polyamide fibers for ground yarn and lace pattern yarn were spun to obtain lace products for inner yarn. The evaluation results of the obtained race products are shown in Table 1.

[Example 4]
With respect to the polyamide fiber for lace ground yarn, the lace ground yarn and the polyamide fiber for lace pattern yarn were spun in the same manner as in Example 1 except that the spinning temperature was set to 280 ° C. to obtain an inner lace product. The evaluation results of the obtained race products are shown in Table 1.

[Example 5]
With respect to the polyamide fiber for lace ground yarn, the lace ground yarn and the polyamide fiber for lace pattern yarn were spun in the same manner as in Example 1 except that the spinning temperature was set to 275 ° C. to obtain an inner lace product. The evaluation results of the obtained race products are shown in Table 1.

[Comparative Example 1]
Regarding the polyamide fiber for lace ground yarn, the lace is the same as in Example 1 except that the amount of amino terminal groups of the nylon 6 chip is 2.2 × ^10-5 mol / g and the relative viscosity of sulfuric acid (ηr) is 2.60. Polyamide fibers for ground yarn and lace pattern yarn were spun to obtain lace products for inner yarn. The evaluation results of the obtained race products are shown in Table 1.

[Comparative Example 2]
Regarding the polyamide fiber for lace ground yarn, the lace ground yarn and the polyamide fiber for lace pattern yarn are spun in the same manner as in Example 1 except that the spinning temperature is 265 ° C. and the strong elongation product is 7.3, and the inner Got a lace product for. The evaluation results of the obtained race products are shown in Table 1.

[Example 6]
Regarding the polyamide fiber for lace ground yarn, spinning of the polyamide fiber for lace ground yarn and lace pattern yarn is the same as in Example 1 except that the number of holes in the spinneret is 3 and the obtained polyamide fiber is 7dtex and 3 filaments. And obtained a lace product for inner. The evaluation results of the obtained race products are shown in Table 2.

[Example 7]
Regarding the polyamide fiber for lace ground yarn, spinning of the polyamide fiber for lace ground yarn and lace pattern yarn is the same as in Example 1 except that the number of holes in the spinneret is 29 and the obtained polyamide fiber is 80 dtex and 29 filament. And obtained a lace product for inner. The evaluation results of the obtained race products are shown in Table 2.

[Example 8]
Regarding the polyamide fiber for lace ground yarn, spinning of the polyamide fiber for lace ground yarn and lace pattern yarn is the same as in Example 1 except that the number of holes in the spinneret is 3 and the obtained polyamide fiber is 5dtex and 3 filaments. And obtained a lace product for inner. The evaluation results of the obtained race products are shown in Table 2.

[Example 9]
Regarding the polyamide fiber for lace ground yarn, spinning of the polyamide fiber for lace ground yarn and lace pattern yarn is the same as in Example 1 except that the number of holes in the spinneret is 36 and the obtained polyamide fiber is 100 dtex and 36 filament. And obtained a lace product for inner. The evaluation results of the obtained race products are shown in Table 2.

[Example 10]
Regarding the polyamide fiber for lace ground yarn, the polyamide fiber for lace ground yarn and lace pattern yarn is spun in the same manner as in Example 1 except that the titanium oxide content of the nylon 6 chip is 0.7 wt%, and the inner lace is used. Got the product. The evaluation results of the obtained race products are shown in Table 1.

[Example 11]
Regarding the polyamide fiber for lace ground yarn, the lace ground yarn and the polyamide fiber for lace pattern yarn are spun in the same manner as in Example 1 except that the titanium oxide content of the nylon 6 chip is 2.7 wt%, and the inner lace is used. Got the product. The evaluation results of the obtained race products are shown in Table 2.

[Example 12]
Regarding the polyamide fiber for lace ground yarn, the lace ground yarn and the polyamide fiber for lace pattern yarn are spun in the same manner as in Example 1 except that the titanium oxide content of the nylon 6 chip is 3.3 wt%, and the inner lace is used. Got the product. The evaluation results of the obtained race products are shown in Table 2.

[Example 13]
(Manufacture of polyamide fiber for lace yarn)
As a polyamide, a nylon 66 chip having an amino-terminal group content of 1.4 × ^10-5 mol / g, a sulfuric acid relative viscosity (ηr) of 2.49, a titanium oxide content of 2.0 wt%, and a melting point of 250 ° C. is used as a water content. It was dried by a conventional method so as to have a concentration of 0.05% by mass. The obtained nylon 66 chips were melted at a spinning temperature (melting temperature) of 320 ° C. and discharged from a spinneret. As the spinneret, a spinneret having 12 holes, a round shape, and a hole diameter of φ0.25 mm was used. The spinning machine was spun using the spinning machine of the embodiment shown in FIG.

After passing the yarn discharged from the spinneret 1 through the inside of the heating cylinder 3 having a length of 50 mm and a temperature of 290 ° C. installed directly under the spinneret, the yarn has an air temperature of 18 ° C. and a wind speed of 35 m / min. It was cooled and solidified by the strip cooling device 4. After that, the refueling device 5 installed at a position 1600 mm below the mouthpiece converges the threads and applies an oil agent, and the fluid entanglement nozzle device 6 performs entanglement processing, and then the take-up roller 7 takes over at 2060 m / min. While stretching between the drawing roller 8 and the drawing roller 8 at 4,120 m / min, the heat was set at 165 ° C. (the temperature of the stretching roller 8), and the fiber was wound by the winding device 9 at 4000 m / min to obtain 33 dtex, 12 filament polyamide fibers. Obtained. The results of evaluation of the obtained polyamide fibers are shown in Table 2. The obtained polyamide fiber was used as a lace ground yarn.

Polyamide fibers for lace pattern yarn were spun in the same manner as in Example 1 to obtain an inner lace product. The evaluation results of the obtained race products are shown in Table 2.

1: Spinning cap 2: Gas supply device 3: Heating cylinder 4: Cooling device 5: Refueling device 6: Fluid confounding nozzle device 7: Take-up roller 8: Stretching roller 9: Winding device

Claims (5)

A polyamide fiber having an amino-terminal group amount of 2.0 × ^10-5 mol / g or less and a strong elongation product of 7.5 cN / dtex or more. The polyamide fiber according to claim 1, wherein the total fineness is 5 to 100 dtex. The polyamide fiber according to claim 1 or 2, which contains 0.5 to 3.0 wt% of titanium oxide. The lace made of the polyamide fiber according to any one of claims 1 to 3. A woven or knitted fabric made of the polyamide fiber according to any one of claims 1 to 3.

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