TW201809385A - Polyamide multifilament, and lace knit and stockings using same - Google Patents

Abstract

Provided is a polyamide multifilament characterized by having a tensile strength at 15% elongation of 4.0 to 6.0 cN/dtex, a strength-elongation product of 10.0 or more, and a yarn unevenness (U%) of 1.2 or less. The present invention provides a high-strength polyamide multifilament with which it is possible to obtain stockings having high softness, durability, and transparency, and a lace knit in which patterns have a beautiful appearance.

Description

Polyamide multifilament and lace fabric and stocking using the same

The present invention relates to a polyamidofilament. More specifically, it relates to a stocking which can provide a softness, durability and transparency when using the polyamide multifilament yarn of the present invention for stockings, and can be provided when used as a base yarn of lace. Polyamide multifilament, a lace fabric with excellent durability and beautiful pattern appearance.

Polyamide fibers or polyester fibers, which are synthetic fibers, are widely used in clothing or industrial applications because of their excellent mechanical and chemical properties. In particular, polyamide fibers have been widely used in stockings, underwear, sportswear, etc. due to their unique flexibility, high strength, color rendering properties when dyeing, heat resistance, and hygroscopicity. General clothing use.

As a consumer of lace, in order to make the pattern look beautiful, it is expected that the durability is equivalent to the conventional one, and the transparency of the lace base yarn is expected. As a consumer demand for stockings, in order to have a good wearing feeling and to show a plain muscular feeling, it is expected that the durability is equivalent to the conventional one, and the pursuit of softness and transparency is also expected. In other words, if it is replaced with polyamido fiber for clothing, it is strongly expected that the fineness which is as strong as conventional is strong.

In order to solve these problems, various techniques for increasing the strength of polyamide fibers have been proposed. For example, Patent Document 1 proposes a lace fabric including a nylon 6 filament of high viscosity type having a stretch of 51 to 64% and a strength of 4.2 to 6.5 cN / dtex.

In Patent Document 2, a stocking is proposed, which includes an elongation of 40 to Polyamide filaments with a 50% strength elongation product of 9.1 or more and about 9.8.

Patent Document 3 proposes a tire cord and a belt including a polyamide-based fiber having an elongation of about 16 to 18%, a strength of 9.8 cN / dtex or more, and a strength elongation product of about 11.4 to 12.2 cN / dtex.

[Prior technical literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 2003-129331

Patent Document 2: International Publication No. 2016/76184

Patent Document 3: Japanese Patent Laid-Open No. 63-159521

However, although the method described in Patent Document 1 can obtain lace with a beautiful pattern appearance, the product of the fiber modulus and the elongation is low, which cannot satisfy the product strength of the lace fabric.

When the method described in Patent Document 2 is extended to the case where the fineness of a covered yarn suitable for a single-core cored elastic yarn is extended, the product of the fiber modulus and the strength elongation is low, and the product strength of the stocking cannot be satisfied.

In the case where the method described in Patent Document 3 is extended to the application of clothing, the fiber modulus is too high, and high-order passability such as yarn breakage and fluff in the manufacturing process of lace or stockings is poor.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to provide a high-strength polyamide multifilament yarn having a high strength elongation product and an appropriate fiber modulus. In more detail, the problem is to use a polyamide compound with a high strength elongation product and an appropriate fiber modulus. Silk provides a lace fabric and stockings. The lace fabric has excellent high-level passability and product quality, can be fine-density, can maintain durability, and the transparency of the lace base yarn is increased, and the pattern appearance is beautiful. The stocking has excellent Its transparency and softness.

In order to solve the above problems, the present invention adopts the following configuration.

(1) A polyamide multifilament yarn characterized by a tensile strength of 4.0 to 6.0 cN / dtex at 15% elongation, a tensile strength product of 10.0 or more, and yarn unevenness (U%) of 1.2 or less.

(2) The polyamide multifilament as described in (1) above, wherein the single yarn fineness is 1.3 to 3.4 dtex.

(3) The polyamide multifilament as described in (1) or (2) above, characterized in that the elongation is 30 to 50%.

(4) The polyamide multifilament as described in any one of (1) to (3) above, wherein the sum of the amount of crystals and the amount of rigid amorphous is 70 to 90%.

(5) A lace fabric obtained by using the polyamide multifilament described in any one of (1) to (4) above for a lace base yarn.

(6) A stocking formed by using the polyamide multifilament yarn described in any one of (1) to (4) as a core covering yarn and using the core covering yarn as a part.

The polyamide multifilament of the present invention is a high-strength polyamide multifilament having a high tenacity product and an appropriate fiber modulus. Furthermore, the polyamide multifilament of the present invention can obtain a lace fabric and stockings. The lace fabric is excellent in high-order passability and product quality, can be fine-density, can maintain durability, and the transparency of the lace base yarn is increased. The pattern has a beautiful appearance, and the stockings have excellent transparency and softness.

1‧‧‧ spinning nozzle

2‧‧‧gas ejection device

3‧‧‧ heating tube

4‧‧‧cooling device

5‧‧‧oil supply device

6‧‧‧ Fluid Interstitial Nozzle Device

7‧‧‧Pull roller

8‧‧‧ extension roller

9‧‧‧ Take-up device

L‧‧‧ multilayer heating cylinder length

Single layer length of L1‧‧‧multi-layer heating tube

LS‧‧‧Cooling start distance

Lg‧‧‧ fueling position

FIG. 1 shows an embodiment of a manufacturing apparatus which can be preferably used in the method for manufacturing a polyamide multifilament according to the present invention.

Fig. 2 is a schematic cross-sectional schematic view showing a spinning nozzle and a heating cylinder which can be preferably used in the method for producing a polyamide multifilament according to the present invention.

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

The polyamide multifilament yarn of the present invention is characterized in that the tensile strength at 15% elongation is 4.0 to 6.0 cN / dtex, the tenacity product is 10.0 or more, and the yarn unevenness (U%) is 1.2 or less.

The polyamide system constituting the polyamide multifilament of the present invention contains a so-called high molecular weight resin having a hydrocarbon group connected to the main chain via a polyamide bond. The polyamide has excellent yarn-making properties and mechanical properties, and is preferably mainly Polycaprolactam (nylon 6) and polyhexamethylene adipamide (nylon 66) are more difficult to gel and have good yarn-making properties, and polycaprolactam (nylon 6) is more preferred. ). In the foregoing, the so-called main, in the case of polycaprolactam, refers to ε-caprolactam, which constitutes polycaprolactam, as a unit of 80 mol% or more. In the case of polyhexamethylene diamine, It refers to hexamethylenediammonium adipate which comprises polyhexamethylene adipamide, which contains 80 mol% or more, and more preferably 90 mol% or more. The other components are not particularly limited, and examples thereof include polylaurylamine, polyhexamethylenehexamethylenediamine, polyhexamethylenenonanediamine, polydecanehexamethylenediamine, and polydodecanediamine. Aminocarboxylic acids, dicarboxylic acids, diamines of hexamethylene diamine, polyhexamethylene xylylenediamine, polyparaxylylene hexamethylenediamine, polym-xylylene hexamethylenediamine and other monomers Wait unit.

In order to effectively express the effect of the present invention, it is preferred that the polyamine does not contain various additives such as a matting agent typified by titanium oxide. However, the additives may be contained as needed within a range that does not inhibit the effects of the heat-resistant agent. In addition, the content may be mixed between 0.001 to 0.1 wt% as needed.

In the polyamidamine multifilament of the present invention, it is necessary to set all the 15% strength, tensile strength product, and U% to the above ranges. In other words, by making the fineness finer, although a lace fabric with increased transparency and a beautiful pattern appearance can be obtained, or a stocking with excellent transparency and softness, the strength of the product decreases, and the durability becomes unbearable. Actual use level. In order to make durability a grade that can withstand actual use, it is necessary to increase the elongation product. In addition, in order to maintain high-level passability or product quality, it is necessary to set the appropriate 15% strength and U%.

Therefore, the present inventors conducted intensive studies and found that in order to provide high-order passability and product quality, excellent durability, and increase the transparency of the lace base yarn, the lace fabric with a beautiful pattern appearance or excellent transparency and softness For sexual stockings, the 15% strength, strength product, and U% must be set to appropriate areas.

The strong elongation product of the polyamide multifilament of the present invention must be 10.0 or more. By setting it as this range, the durability of stockings or lace becomes a grade which can withstand practical use. When the strength elongation product is less than 10.0, the durability of stockings or lace becomes a grade that cannot withstand actual use, and yarn breakage in high-order processing steps increases and high-order passability deteriorates. The tensile elongation product of the polyamide multifilament of the present invention is more preferably 10.3 or more. The larger the product of strength and elongation, the better, but the upper limit value in the present invention is about 11.0.

The tensile strength at 15% elongation (hereinafter referred to as "15% strength") of the polyamide multifilament of the present invention as an index of the physical properties of the raw yarn must be 4.0 to 6.0cN / dtex. The measurement of 15% strength is based on JIS L1013-2010-tensile strength and elongation. The tensile strength-elongation curve is drawn. The value obtained by dividing the tensile strength (cN) at 15% elongation by the fineness is set as 15% strength. The 15% strength simply indicates the value of the fiber modulus. If the 15% strength is higher, it means that the slope of the tensile strength-elongation curve is higher and the fiber modulus is higher. On the other hand, if the 15% strength is lower , It means that the slope of the tensile strength-elongation curve is lower and the fiber modulus is lower.

By setting the polyamide multifilament of the present invention to this range, the durability of stockings or lace fabrics becomes a level that can withstand practical use, and the flexibility is also excellent. In the case where the 15% strength is less than 4.0 cN / dtex, the strength elongation product decreases, and the durability of stockings or lace fabrics becomes a level that cannot withstand actual use. If the 15% strength exceeds 6.0 cN / dtex, the elongation decreases, the texture of stockings or lace fabrics becomes hard and softness is reduced, and the yarn breakage in high-level processing steps increases, and the high-level passability becomes poor, resulting in lower product quality. It is preferably 4.5 to 5.5 cN / dtex.

The elongation of the polyamide multifilament of the present invention is preferably 30 to 50%. By setting it as this range, the yarn breakage in a high-order processing step is reduced, and the quality of a high-order passability product becomes favorable. In particular, high-speed weaving and weaving are excellent in high-order passability. If the elongation is 30% or more, the yarn breakage in the high-level processing steps such as the stocking manufacturing step (core-spun yarn manufacturing step or stocking weaving step) or the lace knitted fabric manufacturing step (warping step, weaving step) is less. The higher-order passability is good. Furthermore, the texture of stockings or lace fabrics is soft and good. If the elongation is less than 50%, the strong elongation product is sufficient, and the durability of stockings or lace fabrics can also withstand actual use. In addition, there are fewer yarn breaks in high-level processing steps, high-level passability, and improved product quality. It is more preferably 35 to 45%.

The sum of the crystalline amount of the polyamide multifilament and the rigid amorphous amount of the present invention is preferably 70 to 90%. The amount of crystals and the amount of rigid amorphous are calculated as follows.

The amount of crystallization (Xc) is calculated by a differential scanning calorimetry (DSC, Differential Scanning Calorimetry) method, and the difference between the heat of fusion and the heat of cold crystallization (ΔHm-ΔHc) is calculated by the formula (1). Here, the heat of fusion of the ΔHm0-based crystalline polyamide is 229.76 J / g.

The rigid amorphous amount (Xra) is calculated from the self-crystallizing amount (Xc) and the movable amorphous amount (Xma) in the formula (2). The movable amorphous content (Xma) is calculated by using a temperature-modulated differential scanning calorimetry (TMDSC, Temperature Modulated Differential Scanning Calorimetry) from the specific heat change (△ Cp) before and after glass transition on the temperature-heat flow velocity reversible curve. Here, △ Cp is the specific heat gap before and after glass transition calculated by extrapolating the tangent to the temperature-heat reversible curve before and after glass transition. The movable amorphous amount (Xma) is calculated by the formula (3). Here, the specific heat difference before and after Tg of the ΔCp0-based amorphous polyamine is 0.4745 J / g.

The amount of rigid amorphous was calculated from the average of two measurements of temperature-modulated DSC and DSC.

Crystallization: Xc (%) = (△ Hm- △ Hc) / △ Hm0 × 100 ... (1)

Rigid amorphous content: Xra (%) = 100- (Xc + Xma) ... (2)

Movable amorphous amount: Xma (%) = △ Cp / △ Cp0 × 100 ... (3)

The sum of the amount of crystals and the amount of rigid amorphous materials mentioned here is a value that simply indicates the degree of relaxation of the alignment of the molecular chains of the polyamide polymer. If the sum of the crystalline amount and the rigid amorphous amount is high, it means that the molecular chain has less deformation, and it is a fiber with higher crystallinity. If the sum of the crystalline amount and the rigid amorphous amount is low, it means that the molecular chain is crosslinked. Larger, less crystalline fibers. By setting the sum of the crystalline amount and the rigid amorphous amount to 90% or less, and the amount of deformation of the molecular chain of the polyamide polymer becomes moderate, it is possible to obtain polyamide fibers, stockings, or lace fabrics that are not too crystalline. Excellent texture or softness. By crystallizing The sum of the amount and the rigid amorphous amount is set to more than 70%, so that the molecular chain of the polyamide polymer can be appropriately deformed, so that the polyamide fiber with excellent crystallinity can be obtained, and the durability of stockings or lace fabrics is excellent. It is more preferably 75 to 85%.

The U% of the polyamide multifilament of the present invention must be 1.2 or less. By setting it as this range, a product quality becomes excellent. If U% exceeds 1.2, after dyeing the lace fabric, the thicker part of the thread is dyed deeper, resulting in poor appearance such as streaks and poor product quality. In the case of stocking use, it is more preferably 1.0 or less, and in the case of lace fabric use, it is more preferably 1.0 or less. The lower the U%, the better, but in the present invention, the lower limit is about 0.4.

In terms of clothing use, the total fineness of the polyamide multifilament of the present invention is preferably 4.0 to 33.0 dtex. In the case of stocking use, it is more preferably 4.0 to 11.0 dtex, and in the case of lace use, it is more preferably 20.0 to 30.0 dtex.

The single yarn fineness of the polyamide multifilament of the present invention is preferably 1.3 to 3.4 dtex. By setting it as this range, stocking or lace is excellent in durability and softness. It is more preferably 1.6 to 3.2 dtex.

The relative viscosity of the sulfuric acid of the polyamide multifilament of the present invention is preferably 2.5 to 4.0. It is more preferably 3.2 to 3.8. By setting the relative viscosity of sulfuric acid to 2.5 to 4.0, the durability of stockings or lace fabrics can be rated to withstand actual use. Furthermore, product quality becomes favorable.

The cross-sectional shape of the polyamide multifilament of the present invention is not particularly limited, and may be, for example, a circular cross-section, a flat cross-section, a lens-shaped cross-section, a trilobal cross-section, a multi-spherical cross-section, a ridge having 3 to 8 convex portions and the same number of concave portions. Profiled section, hollow section, other known profiled sections.

Next, the production of the high-strength polyamide multifilament according to the present invention will be specifically described. An example of a method. FIG. 1 shows an embodiment of a manufacturing apparatus using a direct spinning drawing method which is preferably used in the method for manufacturing a high-strength polyamide multifilament according to the present invention.

The polyamide multifilament of the present invention melts the polyamide resin, measures and transports the polyamide polymer by a gear pump, and finally extrudes the polyamide polymer from the discharge hole provided in the spinning nozzle 1 to form each length. wire. The filaments ejected from the spinning nozzle 1 in this manner are passed around a gas supply device 2 for blowing out steam in order to suppress the contamination of the spinning nozzle shown in FIG. The multilayer heating tube 3 and the cooling device 4 cool and solidify the yarn to room temperature. After that, the oil supply device 5 is used to apply the oiling agent, and the filaments are bundled to form a multifilament. The fluid entanglement nozzle device 6 is used to intertwine, and the drawing roller 7 and the extension roller 8 are drawn. The stretching is performed at the ratio of the circumferential speed of the stretching roller 8. Furthermore, the yarn is heat-treated by the heating of the stretching roller 8 and wound by the winding device 9.

When manufacturing the polyamide multifilament of the present invention, the relative viscosity of the sulfuric acid of the polyamide resin is preferably 2.5 to 4.0. By setting it as this range, a high-strength polyamido multifilament with a high elongation product can be obtained.

The melting temperature is preferably higher than 20 ° C. and lower than 95 ° C. with respect to the melting point of polyamide.

When manufacturing the polyamide multifilament of the present invention, a heating cylinder 3 must be provided on the upper part of the cooling device 4 so as to surround each filament around the entire circumference. By setting the heating cylinder on the upper part of the cooling device 4 and setting the ambient temperature in the heating cylinder within the range of 100 to 300 ° C, the thermal degradation of the polyamide polymer discharged from the spinning nozzle 1 can be reduced. And the orientation is relaxed. 15% strength and high elongation product of multifilament are obtained by easing the orientation of the cold from the mouth to the cooling. In the case where no heating cylinder is provided, the orientation of the cold cooling from the mouth surface to the cooling is used to alleviate the insufficient, so it is difficult to obtain the 15% strength and strength elongation product average. The tendency to meet the requirements of the fiber.

When manufacturing the high-strength polyamidamine multifilament of the present invention, the heating cylinder must be multi-layered. In Patent Document 3, in order to cool slowly, a heating cylinder is proposed that maintains the ambient temperature directly below the mouth at 250 to 450 ° C. Although it is effective in the industrial coarseness range, it is useful in the polycondensate as in the present invention. In the fine-density area of amine multifilament-like clothing, the temperature distribution in the heating tube is fixed, so it is easy to become a state of convective heat convection, which affects the curing state of each filament and becomes an important reason for the U% to deteriorate. Therefore, by setting the heating cylinder to multiple layers and gradually lowering the temperature setting from the upper layer to the lower layer, the thermal convection from the upper layer to the lower layer is deliberately formed, and the downward airflow in the same direction as the accompanying flow of the yarn is suppressed, thereby suppressing The chaos of the heat convection in the heating tube is small, and the yarn sloshing is also small, and the multi-filament with a small U% can be obtained.

The length L of the multilayer heating cylinder also depends on the fineness of the filament, but it is preferably 40 to 100 mm. The multilayer heating cylinder preferably includes two or more layers, and the single-layer length L1 of the multilayer heating cylinder is preferably in a range of 10 to 25 mm.

In addition, if the ambient temperature in the multilayer heating cylinder is in the range of 100 to 300 ° C, a gentle temperature gradient must be set between the layers. For example, when the length L of the multilayer heating cylinder is set to 75mm and the length L1 of the single layer is set to 25mm, the ambient temperature of the upper layer must be set to 250 to 300 ° C, and the ambient temperature of the middle layer to be set to 200 to 250 ° C. Set the ambient temperature of the lower layer to 100 ~ 200 ° C.

With this configuration, the ambient temperature distribution between the mouth and the cooling room is controlled stepwise to 100 to 300 ° C, thereby obtaining a high-strength polyamidite multifilament with good 15% strength, tensile strength product, and U%.

When manufacturing the polyamide multifilament of the present invention, the cooling device 4 can blow the cooling rectified wind A from the fixed direction, or blow the cooling from the outer peripheral side to the center side. It is manufactured by any method, such as a ring-shaped cooling device of the rectified wind A, or a ring-shaped cooling device that blows cooling rectified air from the center side to the outer periphery. In terms of suppressing yarn sloshing or U%, the vertical distance LS (hereinafter referred to as the cooling start distance) from the lower surface of the spinning nozzle to the upper end of the cooling wind blowing portion of the cooling device 4 is preferably 159 ~ A range of 219 mm, more preferably 169 to 189 mm. Regarding the cooling wind speed blown from the cooling air blowing surface, in terms of U% and strength elongation product, it is preferable to fall between 20.0 and 40.0 (m / minute) on the average of the interval from the upper end to the lower end of the cooling blowing portion ).

When manufacturing the polyamide multifilament of the present invention, the position of the oil supply device 5 is the vertical distance Lg (hereinafter referred to as the oil supply position) from the lower surface of the spinning nozzle to the position of the oil supply nozzle of the oil supply device 5 in FIG. 1. ) Also depends on the single yarn fineness and the cooling efficiency of the filaments from the cooling device, but it is preferably 800 to 1500 (mm), and more preferably 1000 to 1300 (mm). In the case of 800 (mm) or more, the filament temperature is reduced to an appropriate level when the oil is applied, and in the case of 1500 (mm) or less, the yarn sloshing caused by the downdraft is also small and can be obtained. Multifilament with lower U%. In the case of 1500 (mm) or less, the distance from the solidification point to the oil supply position is shortened, thereby reducing the spinning tension as the flow decreases, thereby suppressing the spinning alignment and accelerating flow. Excellent, so it can obtain high tenacity multifilament with strong elongation product and high 15% strength. In the case of 800 (mm) or more, the yarn buckling from the head to the oil supply guide becomes appropriate, and it is difficult to be affected by the friction at the guide, and the reduction in strength product and 15% strength is reduced.

When manufacturing the polyamide multifilament of the present invention, as for the spinning speed, it is preferable to set the pull roller 7 to a low speed area of 1000 to 2000 m / min, which can suppress uneven stretching and uniformize the cooling of the yarn. U% can be suppressed to 1.2 or less. In addition, when it is 2000m / min or less, the spinning orientation is suppressed, and the cooling effect of the heating cylinder is promoted. As a result, the deformation of the molecular chain is relaxed and increased, and 15% can be obtained. High-strength multifilament with high strength and elongation product.

In addition, the heat treatment is performed by using the stretching roll 8 as a heating roll, and the heat curing length thereof is preferably 500 to 1200 mm, and the heat treatment temperature is preferably 120 to 180 ° C. The reason is that the heat shrinkage of the multifilament can be designed by performing appropriate heat treatment. By setting the heat-cured length to 500 mm or more, the fiber becomes sufficiently crystallized, so that 15% strength is increased, and the product is excellent in durability. By setting the heat-cured length to 1200mm or less without crystallization of the fiber excessively, 15% strength can be obtained, which is a suitable range, and the texture of the product is soft, and the high-strength step has excellent passability in high-level processing steps. Polyamide multifilament.

The polyamide multifilament of the present invention can be produced by setting a heating cylinder on the upper part of the cooling device 4, setting the ambient temperature in the heating cylinder to a range of 100 to 300 ° C, and further setting the heating cylinder It is a multilayer type, so that a temperature gradient is set in the heating cylinder to deliberately form a descending airflow in the same direction as the accompanying flow of the yarn, so that the oil supply position is 800 ~ 1500mm from the mouth surface, and the spinning speed is set to 1000 ~ 2000m / min, set the thermal curing length after extension to 500 ~ 1200mm.

By using the conditions in this direct spinning and stretching method, a high strength elongation product of 10.0 cN / dtex or higher, a strength of 15% of 4.0 to 6.0 cN / dtex, and a high-strength polyamine compound of U% less than 1.2 can be obtained. wire.

The polyamide multifilament of the present invention is directly supplied to a lace knitting machine as a base yarn in a state of raw silk, and is woven into a lace material by a usual method. As long as the lace material is an embroidery lace, Raschel lace, Leavers lace, or the like, it may be a common weave structure.

The polyamide multifilament of the present invention is used as a covering yarn for a core-spun yarn. Core-spun yarns are used to elasticate polyurethane-based elastic fibers and polyamide-based elastomers. Elastic yarns such as fibers are used as core yarns and single-core core-spun yarns wrapped around a single-layer covered yarn, and double-core core-spun yarns wrapped around a double-layer covered yarn.

The polyamide multifilament of the present invention is used for stockings obtained by using the core-spun yarn described above as a part. In addition, as a knitting machine for stockings, an ordinary socks knitting machine can be used, and there is no limitation, as long as the knitting is performed by the usual method: a knitting machine using 2 or 4 yarns is supplied to the present invention. Core yarn is woven.

Furthermore, the dyeing after weaving, subsequent processing, and final setting conditions may be performed according to a known method, and acid dyes, reactive dyes, or colors are not limited.

[Example]

Hereinafter, the present invention will be described in more detail through examples.

A. Strength, elongation, strong elongation product, 15% strength

The fiber sample was measured in accordance with JIS L1013-2010-tensile strength and elongation, and a tensile strength-elongation curve was drawn. As the test conditions, the type of the test machine was a constant-speed extension type, and the test was performed under the conditions of a chuck interval of 50 cm and a tensile speed of 50 cm / min. Moreover, when the tensile strength at the time of breaking is smaller than the highest strength, the highest tensile strength and the elongation at that time are measured.

The strength and elongation product are obtained by the following formulas.

Elongation = elongation at break (%)

Strength = tensile strength (cN) / fineness (dtex) at break

Strength elongation product = (strength (cN / dtex)) × {elongation (%) + 100} / 100

15% strength = 15% elongation tensile strength (cN) / fineness (dtex).

B. Total fineness, single yarn fineness

The fiber sample was placed in a 1.125m / week ruler and rotated 500 times to make a coil-shaped winding shaft. After drying with a hot air dryer (105 ± 2 ℃ × 60 minutes), the balance was measured with a balance. Mass, the fineness is calculated from the value obtained by multiplying by a given moisture content. In addition, the nominal water content is set to 4.5%.

C. Relative viscosity of sulfuric acid (ηr)

0.25 g of a polyamine fragment sample or a fiber sample was dissolved so that 100 g of 100% sulfuric acid with a concentration of 98% by mass became 1 g, and the flow-down time (T1) at 25 ° C. was measured using an Oshwa type viscometer. Then, the time (T2) when the sulfuric acid alone flows down at a concentration of 98% by mass is measured. The ratio of T1 to T2, that is, T1 / T2 is the relative viscosity of sulfuric acid.

D. Uneven yarn (U%)

A fiber sample was measured using USTER TESTER IV manufactured by zellweger uster, with a sample length: 500 m, a measured yarn speed V: 100 m / min, a Twister: S, 30,000 / min, and 1/2 Inert.

E. Amount of crystal, amount of rigid amorphous

(Xc) is the difference between the heat of fusion and the heat of cold crystallization (ΔHm-ΔHc) calculated by the DSC method, and calculated by the formula (1). Here, the heat of fusion of the ΔHm0-based crystalline polyamide is 229.76 J / g.

The rigid amorphous content (Xra) is calculated from the quantification of self-crystallization (Xc) and the movable amorphous content (Xma) in the formula (2). The movable amorphous content (Xma) is the specific heat change before and after the glass transition on the temperature-heat flow reversible curve of the temperature-modulated DSC method (TMDSC) using temperature modulation (ΔCp). Here, △ Cp is the specific heat difference before and after glass transition calculated by extrapolating the tangent to the temperature-heat flow reversible curve before and after glass transition. The movable amorphous amount (Xma) is calculated by the formula (3). Here, the specific heat difference before and after Tg of the ΔCp0-based amorphous polyamine is 0.4745 J / g ° C.

In addition, the amount of rigid amorphous is calculated from the average of two measurements of temperature-modulated DSC and DSC.

Crystallization: Xc (%) = (△ Hm- △ Hc) / △ Hm0 × 100 ... (1)

Rigid amorphous content: Xra (%) = 100- (Xc + Xma) ... (2)

Movable amorphous amount: Xma (%) = △ Cp / △ Cp0 × 100 ... (3).

The measurement conditions of ordinary DSC and temperature-modulated DSC are implemented under the following conditions.

(a) Ordinary DSC

Data processing was performed using Universal Analysis 2000 using Q1000 manufactured by TA Instrument. The measurement was performed under a nitrogen flow (50 mL / min) under a temperature range of 0 to 300 ° C., a heating rate of 10 ° C./min, and a sample weight of about 5 mg (the caloric data is standardized based on the weight after measurement).

The details of the DSC method are described in [Reference 1] below.

[Document 1]

Wunderlich B., Thermal Analysis of Polymeric Materials, Appendix1 (The ATHAS Data Bank), Springer (2005).

(b) Temperature Modulation DSC

Data processing was performed using Universal Analysis 2000 using Q1000 manufactured by TA Instrument. The measurement was performed under a nitrogen flow (50 mL / min) at a temperature range of 0 to 200 ° C., a heating rate of 2 ° C./min, and a sample weight of about 5 mg (the caloric data is standardized based on the weight after measurement).

This method measures heating and cooling repeatedly with a fixed period and amplitude, and increases the temperature evenly. It can separate the overall DSC message (Total Heat Flow) into reversible components such as glass transition (Reversing Heat). Flow (reversible heat flow) and irreversible components (Nonreversing Heat Flow) such as enthalpy relaxation, hardening reaction, solvent removal, etc. However, melting peaks of crystals appear in either of the reversible and irreversible components.

The details of the temperature-modulated DSC method are described in the above-mentioned [Reference 1].

F. Evaluation of lace (a) Softness

For lace products, the softness of the inspectors (5 persons) who are experienced in texture evaluation is relatively evaluated. As a result, the average of the evaluation points of each examiner is rounded off to the nearest decimal point. For the average, 5 is set to S, 4 is set to A, 3 is set to B, and 1 to 2 are set to C.

5 points: very good

4 points: slightly better

3 points: Normal

2 points: slightly worse

1 point: Poor.

S and A were considered to be flexible.

(b) Durability

The rupture strength was measured in accordance with the JIS L1096-2010, Mullen Type (Method A) rupture strength test method. The rupture strength was measured at three arbitrary locations, and the average value was evaluated in four stages based on the following criteria.

S: above 130kPa

A: Above 100kPa and below 130kPa

B: 90kPa or more and less than 100kPa

C: Less than 90 kPa.

The durability of S and A was considered acceptable.

(c) Quality

For lace products, the degree of staining of the examiners (5 persons) was relatively evaluated. As a result, the average of the evaluation points of each examiner is rounded off to the nearest decimal point. For the average, 5 is set to S, 4 is set to A, 3 is set to B, and 1 to 2 are set to C.

5 points: very good

4 points: slightly better

3 points: Normal

2 points: slightly worse

1 point: poor

Set S and A as acceptable.

(d) Step passability

Weaving operability: The number of yarn breaks during weaving is set to the number of yarn breaks per roll (80m) of lace fabric, and it is expressed by the following standard.

S: 0 or more but less than 5

A: 5 or more and less than 10

B: 10 or more but less than 20

C: 20 or more and less than 30

Let S and A be acceptable.

G. Evaluation of stockings (a) Softness

For stocking products, the softness of the legs of the examiner (5 persons) with rich texture evaluation experience was evaluated while wearing the shape of the human foot. As a result, the average of the evaluation points of each examiner is rounded off to the nearest decimal point. For the average, 5 is set to S, 4 is set to A, 3 is set to B, and 1 to 2 are set to C.

5 points: very good

4 points: slightly better

3 points: Normal

2 points: slightly worse

1 point: poor

S and A were considered to be flexible.

(b) Durability

Put the stockings on the human foot with the front side facing out, align the garter belt at a position of 60cm from the heel to the thigh, and then use the position of 52.5cm from the heel to the thigh as the center. Foot-like thigh Mark the circle mark in advance according to the size of the measurement frame. When the product is fixed to the measurement frame, it is fixed in accordance with the previously marked circular mark, thereby measuring the breaking strength in the same state as the wearing state, and setting it as an index of durability.

The rupture strength is measured in accordance with JIS L1096-2010, the Marlen's method (Method A), and the rupture strength at any three locations is measured. The average value is evaluated in four stages based on the following criteria.

S: above 117.7kPa

A: 98.1kPa or more and less than 117.7kPa

B: Above 88.3kPa and below 98.1kPa

C: Less than 88.3 kPa.

The durability of S and A was considered acceptable.

(c) Quality

For stocking products, the degree of staining of the examiner (5 persons) was relatively evaluated. The result is rounded off from the decimal point of the average of the evaluation points of each examiner. For the average, 5 is S, 4 is A, 3 is B, and 1-2 is C.

5 points: very good

4 points: slightly better

3 points: Normal

2 points: slightly worse

1 point: Poor.

Set S and A as acceptable.

(d) Step passability

The number of stoppages caused by yarn breakage during knitting and knitting of stockings when knitting stockings using a socks knitting machine with continuous operation at 400 rpm for 1 hour was evaluated by the following criteria.

S: Less than 2 yarn breaks,

A: Yarn is broken more than 2 times and less than 4 times,

B: 4 or more yarn breaks but less than 6 times,

C: Broken yarn 6 times or more.

Let S and A be acceptable.

[Example 1] (Manufacture of Polyamide Multifilament)

A nylon 6 chip having a relative sulfuric acid relative viscosity (ηr) of 3.3 and a melting point of 225 ° C, which is polyamine, is dried by a common method so that the moisture content becomes 0.03% by mass or less. The obtained nylon 6 chips were melted at a spinning temperature (melting temperature) of 290 ° C, and were discharged from a spinning nozzle. For the spinning nozzle, a hole number of 42, a circular shape, a hole diameter of 0.25, and 6 threads / head are used.

As for the spinning machine, spinning was performed using a spinning machine (direct spinning stretching machine) in the form shown in FIG. 1. In addition, the heating cylinder is a two-layer heating cylinder with a heating cylinder length L of 50 mm and a single-layer length L1 and L2 of 25 mm respectively. The ambient temperature of the upper heating cylinder is 300 ° C, and the ambient temperature of the lower heating cylinder is Set the temperature at 150 ° C.

Each filament discharged from the spinning nozzle is slowly cooled in a two-layer heating cylinder at an ambient temperature of 150 to 300 ° C, and the yarn is cooled and solidified by a ring-shaped cooling device with a cooling air at a cooling distance of LS169mm and 18 ° C. Room temperature. Thereafter, an oiling agent was applied at a position of 1300 mm from the oil supply position Lg of the nozzle surface, and the filaments were bundled to form a multifilament. After the entanglement was performed by a fluid entanglement nozzle device, the yarn was drawn at a speed of a take-up roller (spin (Wire speed) 1500m / min, heat-cured length 600mm, stretched at 2.8 times through a stretching roller heated to 155 ° C, and wound up to obtain nylon 6 multifilament with 22.0 dtex, 7 filaments.

The evaluation results of the obtained nylon 6 multifilament are shown in Table 1.

(Manufacture of lace fabric)

Next, warp the multifilament yarn, and set the runner length of 21.0cm as the yarn on the back side of the 28G Raschel lace base yarn, and set the runner length of 100.0 as the yarn on the front side of the base yarn. cm, pattern yarn 235 ~ 330dtex, and weave. Then, the original color fabric is refined, dyed, and finally set, thereby obtaining a lace fabric for underwear. Table 1 shows the results of evaluation of the obtained lace products.

[Example 2]

Set the ambient temperature of the heating cylinder in the upper layer to 300 ° C and set the ambient temperature of the heating cylinder in the lower layer to 100 ° C. Slowly cool in the heating cylinder at the ambient temperature of 100 ~ 300 ° C. A nylon 6 multifilament of 22 dtex and 7 filaments was obtained in the same manner as in Example 1 except that the stretching ratio was set to 2.7 times at 1700 m / min, and a lace fabric was obtained. The evaluation results are shown in Table 1.

[Example 3]

Set the ambient temperature of the heating cylinder in the upper layer to 300 ° C, set the temperature so that the ambient temperature of the heating cylinder in the lower layer becomes 200 ° C, and cool slowly in the heating cylinder at the ambient temperature of 200 ~ 300 ° C, and set the extension ratio to 3.0 times. Other than that, a nylon 6 multifilament of 22 dtex and 7 filaments was obtained in the same manner as in Example 1, and a lace fabric was obtained. The evaluation results are shown in Table 1.

[Example 4]

As polyamide, nylon 66 flakes having a sulfuric acid relative viscosity (ηr) of 3.2 and a melting point of 265 ° C. were obtained. In the same manner as in Example 1, nylon 66 multifilament of 22 dtex and 7 filaments was obtained, and lace was obtained. Fabric. The evaluation results are shown in Table 1.

[Comparative Example 1]

The heating cylinder was a single-layer heating cylinder with a heating cylinder length L of 50 mm. The temperature was set so that the ambient temperature became 300 ° C, and the extension ratio was set to 3.2 times. Except that, 22 dtex was obtained in the same manner as in Example 1. , 7 filaments of nylon 6 multifilament, and obtain a lace fabric. The evaluation results are shown in Table 1.

Because it is a single-layer heating tube, the ambient temperature in the heating tube is fixed, the heat convection in the heating tube is chaotic, and the U% becomes worse. In addition, since the ambient temperature setting in the heating cylinder is 300 ° C, which is a temperature close to the spinning temperature, the alignment from the mouth surface to the cooling by Xu cold is insufficient, and the strength is 15%. Therefore, the lace fabric has poor processability, quality, and softness.

[Comparative Example 2]

Set the ambient temperature of the heating cylinder in the upper layer to 200 ° C, and set the temperature so that the ambient temperature of the heating cylinder in the lower layer becomes 100 ° C. Slowly cool in the heating cylinder at the ambient temperature of 100 ~ 200 ° C, and set the pull roller speed to Except for 1700 m / min, a nylon 6 multifilament of 22 dtex and 7 filaments was obtained in the same manner as in Example 1, and a lace fabric was obtained. The evaluation results are shown in Table 1.

Because the ambient temperature setting in the heating cylinder is 100 ~ 200 ° C, which is 90 ° C lower than the spinning temperature, the orientation from the mouth surface to the cooling by Xu cold is not enough to relax, the strength product, 15% strength Lower. Therefore, the durability of the lace fabric is poor.

[Comparative Example 3]

Except that no heating cylinder was provided, a nylon 6 multifilament of 22 dtex and 7 filaments was obtained in the same manner as in Example 1, and a lace fabric was obtained. The evaluation results are shown in Table 1.

Because there is no heating tube, the orientation from the face of the mouth to the cooling is relieved by the cold cooling, and the product of strong elongation and 15% strength is low. Therefore, the durability of the lace fabric is poor.

[Example 5]

A nylon 6 multifilament of 22 dtex and 7 filaments was obtained in the same manner as in Example 1 except that the oil supply position Lg was set to 800 mm and the stretching ratio was set to 3.0 times, and a lace fabric was obtained. The evaluation results are shown in Table 2.

[Example 6]

A nylon 6 multifilament of 22 dtex and 7 filaments was obtained in the same manner as in Example 1 except that the oil supply position Lg was set to 1500 mm and the draw ratio was set to 2.7 times, and a lace fabric was obtained. The evaluation results are shown in Table 2.

[Comparative Example 4]

A nylon 6 multifilament of 22 dtex and 7 filaments was obtained in the same manner as in Example 1 except that the oil supply position Lg was set to 600 mm and the stretching ratio was set to 3.2 times, and a lace fabric was obtained. The evaluation results are shown in Table 2.

Since the oil is applied without the filament temperature falling to room temperature, the U% becomes worse. In addition, the yarn from the mouth surface to the oil supply guide has a large bend, and the strength product has a low elongation product of 15% due to the influence of friction at the oil supply guide. Therefore, the lace fabric has poor processability, durability, and quality.

[Comparative Example 5]

A nylon 6 multifilament of 22 dtex and 7 filaments was obtained in the same manner as in Example 1 except that the oil supply position Lg was set to 3000 mm and the elongation was set to 2.7 times, and a lace fabric was obtained. The evaluation results are shown in Table 2.

The effect of yarn sloshing caused by the downdraft is large, and the U% becomes worse. In addition, due to the influence of the accompanying flow, the spinning tension becomes high, and the spinning alignment proceeds. 15% strength, low elongation product. Therefore, the quality and durability of lace fabrics are poor.

[Example 7]

A nylon 6 multifilament of 22 dtex and 7 filaments was obtained in the same manner as in Example 1 except that the take-up roll speed (spinning speed) was set to 1000 m / min and the draw ratio was set to 3.8 times. Lace fabric. The evaluation results are shown in Table 2.

[Example 8]

A nylon 6 multifilament of 22 dtex and 7 filaments was obtained in the same manner as in Example 1 except that the take-up roll speed (spinning speed) was set to 2000 m / min and the draw ratio was set to 2.3 times. Lace fabric. The evaluation results are shown in Table 2.

[Comparative Example 6]

A nylon 6 multifilament of 22 dtex and 7 filaments was obtained in the same manner as in Example 1 except that the take-up roll speed (spinning speed) was set to 800 m / min and the draw ratio was set to 4.5 times. Lace fabric. The evaluation results are shown in Table 2.

Due to the lower spinning speed, the spinning tension becomes lower, the effect of yarn sloshing is greater, and U% becomes worse. In addition, the slow cooling effect of the heating cylinder becomes larger, and the deformation of the polyamide molecular chain is eased and excessive, and the strength is higher at 15%. Therefore, the lace fabric has poor processability, quality, and softness.

[Comparative Example 7]

Except that the take-up roll speed (spinning speed) was set to 2500 m / min and the draw ratio was set to 1.9 times, 22 dtex, 7 filaments were obtained in the same manner as in Example 1. Dragon 6 multifilament and get lace fabric. The evaluation results are shown in Table 2.

Because the spinning speed is higher, the deformation speed becomes higher, the unevenness of the deformation speed increases, the unevenness of the traction extension increases, and the U% becomes worse. In addition, the slow cooling effect of the heating cylinder becomes lower, the deformation of the polyamine molecular chain is not sufficiently relaxed, and the 15% strength and strength elongation product are low. Therefore, the quality and durability of lace fabrics are poor.

[Example 9]

A nylon 6 multifilament of 22 dtex and 7 filaments was obtained in the same manner as in Example 1 except that the heat-cured length was set to 1200 mm using extension rollers having different diameters, and a lace fabric was obtained. The evaluation results are shown in Table 2.

[Comparative Example 8]

A nylon 6 multifilament of 22 dtex and 7 filaments was obtained in the same manner as in Example 1 except that the heat-cured length was set to 1800 mm using extension rollers having different diameters, and a lace fabric was obtained. The evaluation results are shown in Table 2.

The crystallization of hot fibers is excessive, and the 15% strength is high. Therefore, the lace fabric has poor processability and softness.

[Example 10] (Manufacture of Polyamide Multifilament)

A nylon 6 chip having a relative sulfuric acid relative viscosity (ηr) of 3.3 and a melting point of 225 ° C, which is polyamine, is dried by a common method so that the moisture content becomes 0.03% by mass or less. The obtained nylon 6 chips were melted at a spinning temperature (melting temperature) of 290 ° C, and were discharged from a spinning nozzle. For the spinning nozzle, a hole number of 30, a circular shape, a hole diameter of 0.20, and 6 threads / head were used.

As for the spinning machine, spinning was performed using a spinning machine of the aspect shown in FIG. 1. In addition, the heating cylinder is a two-layer heating cylinder with a heating cylinder length L of 50 mm and a single-layer length L1 and L2 of 25 mm respectively. The ambient temperature of the upper heating cylinder is 300 ° C, and the ambient temperature of the lower heating cylinder is Set the temperature at 150 ° C.

Each filament discharged from the spinning nozzle is slowly cooled in a two-layer heating cylinder at an ambient temperature of 150 to 300 ° C, and the yarn is cooled and solidified by a ring-shaped cooling device with a cooling air at a cooling distance of LS169mm and 18 ° C. Room temperature. Thereafter, an oiling agent was applied at a position of 1300 mm from the oil supply position Lg of the nozzle surface, and the filaments were bundled to form a multifilament. After the entanglement was performed by a fluid entanglement nozzle device, the drawing roller speed (spinning speed) 1500m / min and 600mm heat-cured length were stretched at a draw ratio of 2.6 times through an extension roll heated to 155 ° C and rolled up to obtain a nylon 6 multifilament with 8.0 dtex and 5 filaments.

The evaluation results of the obtained nylon 6 multifilament are shown in Table 3.

(Manufacture of stockings)

Next, this multifilament was used for the covering yarn of the core-spun yarn. The polyurethane elastic yarn of 22decitex was used as the core yarn, and the traction was set to 3.0 times. Stranded core, making single-strand cored elastic yarn (SCY).

The obtained SCY was woven using a socks knitting machine. Then, the original knitted fabric was refined, dyed, and finally set at 120 ° C for 30 seconds to obtain a pantyhose product. Table 3 shows the results of evaluating the legs of the obtained pantyhose products.

[Comparative Example 9]

Except that no heating cylinder was provided, a nylon 6 multifilament of 8 dtex and 5 filaments was obtained in the same manner as in Example 10, and a stocking product was obtained. The evaluation results are shown in Table 3.

Because there is no heating tube, the orientation from the face of the mouth to the cooling is relieved by the cold cooling, and the product of strong elongation and 15% strength is low. Therefore, the durability of stocking products is poor.

[Comparative Example 10]

Except that no heating cylinder was provided, the draw roll speed (spinning speed) was set to 2500 m / min, and the draw ratio was set to 1.5 times. Except that, a nylon 6 of 8 dtex and 5 filaments was obtained in the same manner as in Example 10. Multifilament and get stockings. The evaluation results are shown in Table 3.

Because the spinning speed is higher, the deformation speed becomes higher. As a result, the unevenness of the deformation speed increases, the unevenness of the traction extension increases, and the U% becomes worse. In addition, since the heating cylinder is not provided, the deformation from the mouth surface to the cooling by slack cooling is insufficient to reduce the 15% strength and strength elongation product. Therefore, the quality and durability of stocking products are poor.

[Comparative Example 11]

The heating cylinder is a single-layer heating cylinder with a heating cylinder length L of 50 mm, and the temperature is set so that the ambient temperature becomes 300 ° C. The oil supply position Lg is set to 3000 mm, and the pull roller speed (spinning speed) is set to 600 m. The nylon 6 multifilament of 8 dtex and 5 filaments was obtained in the same manner as in Example 10 except that the stretching ratio was set to 4.5 times, and a stocking product was obtained. The evaluation results are shown in Table 3.

Because it is a single-layer heating tube, the ambient temperature distribution in the heating tube is fixed, and the heat convection in the heating tube is chaotic. Furthermore, due to the low oil supply position (head to oil supply) The distance is longer) or the spinning speed is lower, so the effect of yarn sloshing is larger and U% becomes worse. In addition, the slow cooling speed of the heating cylinder increases the cooling effect of the heating cylinder, and the deformation of the polyamide molecular chain is moderated and excessive. Further, the crystallization of the fiber due to the long thermal curing length is excessively advanced, 15%. High intensity. Therefore, the performance, quality, and flexibility of the stocking products are poor.

Claims (6)

A polyamide multifilament yarn is characterized in that the tensile strength at 15% elongation is 4.0 to 6.0 cN / dtex, the tenacity product is 10.0 or more, and the yarn unevenness (U%) is 1.2 or less. For example, the polyamide multifilament yarn of claim 1, wherein the single yarn fineness is 1.3 to 3.4 dtex. For example, the polyamide multifilament yarn of item 1 or 2 has an elongation of 30-50%. The polyamide multifilament according to any one of claims 1 to 3, wherein the sum of the crystalline amount and the rigid amorphous amount is 70 to 90%. A lace fabric obtained by using the polyamide multifilament of any one of claims 1 to 4 for a lace base yarn. A stocking formed by using the polyamide multifilament yarn of any one of claims 1 to 4 as a core covering yarn and using the core covering yarn as a part.