JP6070557B2 - Polyamide black original yarn, false twist yarn, covering elastic yarn and leg knit - Google Patents

Description

  The present invention relates to a polyamide black original yarn, a false twist yarn, a covering elastic yarn, and a leg knit that have a soft texture and can produce a deep black color.

  For leg knits such as stockings and tights, polyamide yarns typified by nylon 6 and nylon 66 are mainly used. Conventionally, in order to obtain the softness of leg knit products, it has been generally performed to reduce the single fiber fineness of the polyamide yarn. However, when the single fiber fineness is reduced, softness is obtained, but the appearance of the leg knit product becomes whitish due to diffused reflection of light, making it difficult to obtain a dark color, and the single fiber breaks during wearing, causing pilling, etc. Problems relating to appearance such as deterioration in durability and appearance have arisen. In particular, as a consumer demand for tights, in addition to the soft texture, durability, and reasonable market price, color (color development) is an important factor, and the deep black color that is the mainstream of tights color A polyamide yarn capable of being

In order to solve this problem, Patent Document 1 exemplifies that ultrafine fibers with good black color development can be obtained by incorporating carbon black in polyamide yarn.
JP 2002-146624 A

  In the method described in Patent Document 1, an ultrafine polyamide yarn having a single fiber fineness of 0.0001 to 0.06 dtex is obtained by removing the sea component of the sea-island composite yarn. In leg knit products such as stockings and tights, the yarn is soft. Although the texture is obtained, on the other hand, there are problems such as inability to obtain a deep black color, generation of pilling (durability and appearance), and cost increase for removing sea components. In addition, since it is necessary to elute PE, which is a sea component, with toluene or the like, there is a problem that elastic yarn such as spandex that becomes the core yarn of the covering yarn is deteriorated, the strength is weakened, and the stretchability is impaired.

  An object of the present invention is to solve the above-mentioned conventional problems and to provide a polyamide black original yarn having a soft texture and capable of deep black color development. It is another object of the present invention to provide a polyamide black original false twisted yarn, covering elastic yarn, and leg knit capable of deep black color development.

In order to solve the above problems, the polyamide black original yarn of the present invention has the following configuration. That is, it is a polyamide black original yarn containing 1 to 5% by mass of carbon black, the average particle size of carbon black in the polyamide is 1 to 20 μm, and the single fiber fineness of the polyamide black original yarn is 0.8 to 1.7. dtex, and a polyamide black original yarn whose main component is nylon 6 or nylon 66.

Moreover, the false twisted yarn of the present invention has the following configuration. That is,
A false twisted yarn obtained by false twisting the polyamide black original yarn.

The covering elastic yarn of the present invention has the following configuration. That is,
A covering elastic yarn using the polyamide black original yarn or the false twisted yarn as a wound yarn.

The leg knit of the present invention has the following configuration. That is,
A leg knit using at least one of the polyamide black original yarn, the false twisted yarn, and the covering elastic yarn as at least a part of the leg portion.

  In the polyamide black original yarn of the present invention, the polyamide is preferably nylon 6.

  The polyamide black raw yarn of the present invention preferably has a dry heat shrinkage CV value of 4.0% or less.

  According to the present invention, a polyamide black original yarn, false twisted yarn, and covering elastic yarn suitable for leg knits such as stockings and tights that have a soft texture and are capable of deep black color development can be obtained.

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

  The polyamide constituting the polyamide black raw yarn of the present invention is a resin composed of a high molecular weight body in which a so-called hydrocarbon group is connected to the main chain through an amide bond, and such a polyamide has a yarn forming property and mechanical properties. Polycaproamide (nylon 6) and polyhexamethylene adipamide (nylon 66) are preferable, and when carbon black is contained, polycaproamide (nylon 6) is difficult to gel and has good yarn-making properties. Is more preferable. The term “mainly” as used herein means that ε-caprolactam units constituting polycaproamide are 80 mol% or more in all monomer units, and more preferably 90 mol% or more. Examples of other components include, but are not limited to, polydodecanoamide, polyhexamethylene adipamide, polyhexamethylene azelamide, polyhexamethylene sebamide, polyhexamethylene dodecanoamide, polymetaxylylene adipa Examples thereof include units such as aminocarboxylic acid, dicarboxylic acid, and diamine, which are monomers constituting imide, polyhexamethylene terephthalamide, polyhexamethylene isophthalamide and the like.

  The degree of polymerization of the polyamide used for the polyamide black raw yarn may be appropriately selected from false twisting, woven or knitted fabric, required characteristics of the textile product, or an appropriate range in order to stably obtain them, but preferably 25 The relative viscosity of 98% sulfuric acid at ° C is in the range of 2.0 to 3.6, and more preferably in the range of 2.4 to 3.3.

  Examples of the carbon black used for the polyamide black raw yarn of the present invention include furnace black, channel black, thermal black, acetylene black, lamp black and the like, and are not particularly limited. Is preferred. Carbon black production methods are divided into acetylene black and thermal black as pyrolysis methods, oil smoke collection (so-called lamp black) and furnace black as incomplete combustion methods, and the difference in the characteristics of carbon black due to differences in this production method . The thermal decomposition method that must maintain a reaction environment near 2,000 ° C. requires a lot of energy for production, and thus has low practicality in terms of cost and production environment. On the other hand, the incomplete combustion method is highly practical in terms of cost and manufacturing environment. The furnace method, which is a typical incomplete combustion method, is easy to control the particle size and structure size, and uses the furnace black obtained by the furnace method from the color and yarn-making property of the polyamide black raw yarn. It is preferable to do. In particular, furnace black obtained by an oil furnace method is more preferable for the production of small particle size furnace black.

  In addition, the structure of carbon black is formed at the manufacturing stage. The structure is the minimum unit of carbon black, and its index can be indicated by the DBP oil absorption. The oil absorption referred to here is a value measured according to JIS K 6217-4 (2008). The DBP oil absorption of carbon black used in the polyamide black raw yarn of the present invention is preferably 10 to 300 ml / 100 g. When the DBP oil absorption is within the above preferred range, when a polyamide black raw yarn is used, it is easy to produce a deep black color, while dispersibility in the polyamide polymer is good and coarse particles are produced during the production of the polyamide black raw yarn. No increase in yarn, excellent yarn-making properties, and excellent strength, which is a mechanical property of polyamide black original yarn.

  The carbon black contained in the polyamide black raw yarn of the present invention needs to have an average particle diameter of 1 to 20 μm. The average particle size referred to here is a structure having a large particle size, generally called coarse particles, and the measurement method is to use an optical microscope to prepare a polyamide black original yarn on a preparation heated to a melting point of the polyamide black original yarn + 20 ° C. A 0.1 g sample of the sample was placed, spread between film slides and filmed at a magnification of 500 times, and the longest major axis of the carbon black structure was arbitrarily measured from one sample to calculate the average value of 20 samples. It is the value. At this time, the photograph taken may be enlarged to a size that facilitates particle size measurement. When the average particle size exceeds 20 μm, there are many yarn breakage during the production of the polyamide black original yarn, and the yarn-making property is deteriorated. The strength, which is a mechanical property, decreases. If it is less than 1 μm, the dynamic friction coefficient of the yarn becomes high, and a lot of pilling occurs at a portion where there is a lot of friction such as toes, heels, and knees when worn. Preferably it is 1-10 micrometers. In order to set the average particle size of carbon black contained in the polyamide black raw yarn of the present invention to 1 to 20 μm, filtration of the molten polymer containing carbon black is performed at the time of producing the polyamide black original chip and at the time of producing the polyamide black original yarn. It becomes possible by doing. The filtration method is not particularly limited, but it is preferable to install a filter in a molten polymer passage or a spin pack. More preferably, a filter is installed in the spin pack, and the filter used in the spin pack is more preferably 10 to 20 μm cut.

  Further, when carbon black is contained in the polyamide melt polymer, the carbon black particles are likely to become secondary particles or tertiary particles and become coarse particles. For this reason, the carbon black is easily clogged only by installing the filter only in the spinning pack, the filtration pressure is greatly increased, the pack life is shortened, and the productivity is easily lowered. As a preferred melt-spinning method for containing polyamide in a carbon black, in addition to installing a filter in a spinning pack, a master chip containing carbon black at a high concentration in a polyamide and a polyamide chip not containing carbon black are blended. And melt spinning. Furthermore, by installing a filter during the production of the master chip, it is possible to eliminate coarse particles, suppress an increase in filtration pressure in the production of polyamide black yarn, increase the pack life, and improve productivity. It becomes. In addition, the filter used at the time of master chip manufacture becomes like this. Preferably it is 20-50 micrometers cut.

  The content of carbon black contained in the polyamide black original yarn of the present invention needs to be 1 to 5% by mass. The content referred to here is TG-DTA, and the change in weight of the polyamide black original yarn is measured under the conditions of temperature range: room temperature to 900 ° C., heating rate: 100 ° C./min, air flow rate: 20 ml / min. Then, the value calculated from the ratio reduced in the region of 650 to 900 ° C. is regarded as the disappearance amount of carbon black, and is defined as the carbon black content in the polyamide black original yarn. When the content is less than 1% by mass, a deep black color cannot be obtained when a leg knit product such as stockings or tights is formed. If the content exceeds 5% by mass, not only will there be a lot of yarn breakage during the production of the polyamide black original yarn, but the yarn-making property will deteriorate, and the strength, which is the mechanical property of the polyamide black original yarn, will decrease. A preferable content is 2 to 4% by mass.

  Moreover, as long as the amount and type do not impair the object of the present invention, additives for improving productivity such as heat resistance may be blended, matte, moisture absorption, antibacterial, ultraviolet shielding, heat insulation. Additives that have functions such as these may be blended. However, the addition of inorganic particles exceeding 1 μm is not preferred because the yarn-making property, the durability of products such as leg knits such as stockings and tights, and the black color developability are reduced, and the addition of inorganic particles including white pigments is not preferred. Although not limited, it is preferable that it is 2.0 mass% or less with respect to a polyamide black original yarn, and it is more preferable that it is less than 1.0 mass%.

  The polyamide black original yarn of the present invention preferably has a CV value of 4.0% or less of the dry heat shrinkage stress of the polyamide black original yarn. The CV value of the dry heat shrinkage stress is the shrinkage variation in the length direction of the polyamide black raw yarn, and if the CV value of the dry heat shrinkage stress is in the above preferred range, the processing tension is difficult to fluctuate during false twisting. No crimped spots such as twists are generated, and the quality of the fabric surface of products such as leg knits is good. On the other hand, shrinkage spots are not generated in heat treatment such as scouring and foot shape set, and the quality of the fabric surface is good. Become. In order to make the CV value 4.0% or less, it is preferable to reduce variation in the content of carbon black contained in the polyamide black raw yarn. In order to reduce variation in the carbon black content contained in the polyamide black original yarn, for example, when blending a high-concentration master tip containing carbon black and a polyamide tip not containing carbon black in a polyamide and melt spinning High-concentration carbon black can be sufficiently kneaded by kneading with a biaxial extruder or using a kneading device installed in a polymer pipe such as a static mixer or high mixer. It is possible to reduce variation. The variation in the carbon black content is determined by measuring the carbon fiber content of a single fiber using the above-described TG-DTA, and a preferable range is 10% or less in terms of CV value.

  The polyamide black original yarn of the present invention needs to have a single fiber fineness of 0.8 to 2 dtex. Conventionally, in order to obtain a soft texture of leg knit products, it is generally performed to reduce the single fiber fineness. However, if the single fiber fineness is less than 0.8 dtex, a soft texture can be obtained, but it is being worn. The single fiber breaks and pilling or the like occurs, resulting in poor durability and appearance. Further, many yarn breaks occur during the production of the polyamide black original yarn, and the yarn-making property is deteriorated. When the single fiber fineness exceeds 2 dtex, the texture becomes hard. Preferably, it is 0.8 to 1.5 dtex. Moreover, although the total fineness is not specifically limited, When using as a leg knit product, 8-155 dtex is preferable.

  The polyamide black raw yarn of the present invention preferably has a strength of 2 cN / dtex or more, more preferably 2 to 6 cN / dtex. By setting the strength to 2 cN / dtex or more, the yarn breakage during processing in the next step such as false twisted yarn and covering elastic yarn, and durability (pilling property) when used as a leg knit product are at a practical level. Further, the upper limit of the strength of the polyamide black original yarn is not limited, but if the strength is increased, the elongation is lowered, and there are many yarn breaks during the production of the polyamide black original yarn, resulting in poor yarn production. Is preferable from the standpoint of yarn-making property.

  The method for producing the polyamide black original yarn of the present invention will be described.

  The polyamide black original yarn of the present invention is most excellent in production by melt spinning from the viewpoint of productivity and cost. In addition, with respect to the production method by melt spinning, a method in which the spinning-stretching step is continuously performed (direct spinning stretching method), a method in which the unstretched yarn is wound once and then stretched (two-step method), or a spinning speed is set to 3, Although it can be produced by any method such as a method (high speed spinning method) that substantially eliminates the drawing step at a high speed of 000 m / min or more, when used as a false twisted yarn, high crimpability is obtained. A high-speed spinning method that is excellent in cost is preferable. Examples of production by the high speed spinning method will be described below.

  First, the melting part will be described. In melting the polyamide, a pressure melter method or an extruder method can be mentioned, but both are not particularly limited. The melting temperature is preferably the melting point of the polyamide polymer + 20 ° C. to the melting point + 60 ° C. For example, when a nylon 6 polymer is used, since the melting point is 225 ° C, a melting temperature of 245 to 285 ° C is preferable.

  The method of containing carbon black includes a method in which a master chip containing carbon black at a high concentration in polyamide and a polyamide chip not containing carbon black are blended and melt-spun, and a method in which carbon black is directly contained by a feeder or the like. Can be mentioned. The carbon black content of the master chip is preferably 10 to 30% by mass. Setting the carbon black content of the master chip to 10% by mass or more is preferable from the viewpoint of the production cost of the polyamide black original yarn, and setting it to 30% by mass or less is preferable from the viewpoint of aggregation of the carbon black.

  The polyamide containing carbon black flowing into the spinning pack is discharged by a known spinneret. Further, the spinning temperature (so-called temperature keeping around the polymer pipe or the spinneret) is preferably a melting point of the polyamide polymer + 20 ° C. to a melting point + 60 ° C.

  As described above, since carbon black easily aggregates even in a molten polymer, it is preferable to install a filter in the spin pack.

  The polyamide black original yarn discharged from the spinneret is cooled and solidified, applied with an oil agent, and then taken up. The draw ratio is appropriately set so that the elongation of the polyamide original yarn is in the range of 50 to 70%, and winding is performed at a winding speed of 3,000 to 5,000 m / min without heat setting in the spinning process. It is preferable to take. In addition, it is possible to perform entanglement using a known entanglement device in the process up to winding. If necessary, the number of confounding can be increased by giving a plurality of times. Furthermore, it is also possible to add an oil agent immediately before winding.

  The false twisted yarn of the present invention and the manufacturing method thereof will be described.

  The false twisted yarn of the present invention can be obtained by false twisting the polyamide black original yarn, but the method of false twisting the polyamide black original yarn into a false twist yarn is not particularly limited. The twisting method is not limited to a spindle method, a triaxial twister method, a belt nip method, or the like. It is preferable to use a spindle method when it is desired to increase crimping, and it is preferable to use a triaxial twister or belt nip which is a friction false twisting method when it is desired to increase the processing speed and reduce the production cost. The heating method is not limited, and a hot plate or a high-temperature short heater may be used. The set temperature can be freely set according to the target texture. It is recommended to use 170-190 ° C. with proamide (nylon 6) and 180-200 ° C. with polyhexamethylene adipamide (nylon 66). Even if a cooling plate is used as the cooling method, air cooling, water cooling, and the like can be mentioned, but the cooling plate is preferably used in consideration of efficiency and yarn damage. A preferred crimped characteristic of the false twisted yarn is 3 to 50%. When the crimped characteristic of the processed yarn is within the above preferable range, the softness is excellent when the leg knit is formed, but it is not necessary to apply a large amount of twist at the time of false twisting, and fluff is hardly generated. In addition, the crimp characteristic said here is the value calculated by measuring with the measuring method mentioned later, and uses it as the parameter | index of the bulkiness of false twisted yarn.

  The covering elastic yarn of the present invention and the manufacturing method thereof will be described.

  As the wound yarn of the covering elastic yarn of the present invention, a polyamide black original yarn and a false twisted yarn obtained by false twisting a polyamide black original yarn can be used.

  The elastic yarns that form the core yarn of the covering elastic yarn include polyurethane elastic yarns, polyamide elastomer elastic yarns, polyester elastomer elastic yarns, natural rubber yarns, synthetic rubber yarns, butadiene yarns, etc. More preferred for knits are polyurethane-based elastic yarns and polyamide-based elastomer elastic yarns because of their elastic properties, thermal properties, durability, and the like. Further, when carbon black or the like is contained in the elastic yarn and the black elastic yarn is used, a deeper black is obtained when a leg knit is obtained.

  The thickness of the covering elastic yarn varies depending on the use of the leg knit and the setting of the tightening pressure, but is generally preferably about 8 to 80 dtex. More preferred is 11 to 44 dtex. When the thickness of the covering elastic yarn is within the above-mentioned preferable range, the yarn strength is sufficiently excellent, so that troubles such as core yarn breakage are difficult to occur during the production of covering elastic yarn and leg knit knitting, and elasticity and durability as a leg knit. While sufficient, the tightening force does not become too strong, and there is no feeling of pressure or coarseness.

The number of coverings may be designed taking into consideration the fineness, shrinkage rate, product texture, pilling resistance, and snag resistance of the polyamide black original yarn, false twisted yarn obtained by false twisting the polyamide black original yarn, When single-covering false twisted yarn made by false twisting of black original yarn, (56 / processed yarn fineness) ^1/2 × 500 to (56 / processed yarn fineness) ^1/2 × 1000 T / m For example, when single-covering a 56 dtex false twisted yarn, 500 to 1,000 T / m is preferable. Moreover, what is necessary is just to design according to the landing pressure which aims at draft magnification, for example, it is preferable to set to 2.5 to 3.5 times. Covering is preferably single covering because of the softness of the texture and elasticity.

  The thus obtained polyamide black original yarn, false twisted yarn obtained by false twisting the polyamide black original yarn, and covering elastic yarn can be preferably used for leg knit.

  The leg knit of the present invention will be described.

  The knitting structure that constitutes the leg knit of the present invention is not limited to a flat knitting, a rubber knitting, a pearl knitting, and those formed by these changed knitting structures. It is more preferable to have a portion composed of a basic structure, and it is even more preferable to have a portion composed of flat knitting.

  In the leg knit of the present invention, it is preferable to use at least one of polyamide black original yarn, false twisted yarn, and covering elastic yarn as at least a part of the leg portion. In addition, the said leg part points out the part from the base of a foot (garter part) to a toe (sole part).

  The yarn used is a so-called Zokki type that uses only a covering elastic yarn wound with a polyamide black original yarn or a false twisted yarn made by false twisting a polyamide black original yarn, but the polyamide black original yarn or polyamide black original yarn is also used. There is no problem even with a knitting type in which a covering elastic yarn using a false twisted yarn formed by false twisting and a false twisted yarn obtained by alternately twisting a polyamide black raw yarn or a polyamide black original yarn are alternately knitted. In addition, as a use thread | yarn which comprises a leg knit, using a thread | yarn as needed, such as a sewing thread | yarn, is not limited.

  Moreover, although there is no restriction | limiting as a knitting machine to be used, A sock knitting machine is used preferably.

  Here, the leg knit targeted by the present invention includes stockings, tights, leggings, trenka, spats, foot covers, socks and the like. Stockings whose part is significantly longer than stockings, tights with panties at the top, and pantyhose.

  If the leg knit consists of a panty part and a leg part and uses the polyamide black original yarn, false twisted yarn, and covering elastic yarn of the present invention for all of the panty part and the leg part, the leg knit is a leg knit. When the polyamide black original yarn, false twisted yarn, and covering elastic yarn of the present invention are used for all of the leg portions, the dyeing step can be omitted. If the dyeing process is further subdivided, there are a scouring process, a dyeing process, and a finishing process, and this dyeing process can be omitted. The manufacturing cost of this dyeing process includes not only the cost of dyes but also the time and processing costs of dyeing at high temperatures for a long time. Not only shortening the time, but also reducing manufacturing costs including dyes and fuel costs. This makes it possible to provide leg knits to consumers at a reasonable market price. Conventionally, in the case of dyeing polyamide yarn in black, when trying to obtain a deep black color, it is necessary to increase the dye concentration, but in order to obtain softness, the single fiber fineness is reduced and the dye concentration is reduced. If it is raised, there is a problem that the fastness to washing deteriorates. However, in the present invention, not only the dyeing process can be omitted, but there is no problem of deterioration in fastness to washing associated with the use of a high concentration of dye, and a leg knit having a long and deep black color can be obtained.

  Further, the finishing may be performed by applying a known finishing agent (softening agent). At this time, you may give functional agents, such as antibacterial and UV cut.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example at all unless the summary is exceeded. Moreover, the measuring method of the physical property of the polyamide black original yarn of this invention is as follows.
A. Average particle size of carbon black (μm)
Using an optical microscope, 0.1 g of a polyamide black original yarn sample is placed on a preparation heated to 245 ° C. for nylon 6 and 275 ° C. for nylon 66, spread on a slide glass and spread into a film, and a magnification of 500 times The 20 longest diameters of the carbon black structure were arbitrarily measured from one sample, and the average value of 20 was calculated.
B. Carbon black content (% by mass)
TG-DTA (SII Nano Technology Co., Ltd. thermogravimetric measuring device SII TG / DTA 6200), polyamide black raw yarn 1.4 mg sample, temperature range: room temperature to 900 ° C., temperature rising rate: 100 This is a value calculated from the ratio of weight loss of polyamide black raw yarns measured under the conditions of ° C / min and atmospheric flow rate: 20 ml / min and reduced in the region of 650 to 900 ° C. The measurement was performed 4 times, and the average value was defined as the carbon black content.
C. Sulfuric acid relative viscosity (η _r )
0.25 g of a polyamide chip (sample) was dissolved in 100 ml of sulfuric acid having a concentration of 98% by mass, and the flow time (T ₁ ) at 25 ° C. was measured using an Ostwald viscometer. Subsequently, the flow time (T ₂ ) of only sulfuric acid having a concentration of 98% by mass was measured. The ratio of _{T 1} with respect to T _2, i.e. the _T 1 / _{T 2} and sulfuric acid relative viscosity.
D. Thread-making property The yarn breakage per ton when producing a polyamide black original yarn was shown according to the following criteria.

a: Less than 2 yarn breaks,
b: thread breakage of 2 or more and less than 4 times,
c: Thread breakage 4 or more and less than 6 times,
d: Thread breakage 6 or more and less than 8 times,
e: Thread breakage 8 times or more.
E. Fineness, single fiber fineness Polyamide black original yarn is 0.35 mN x indicated dtex, false twisted yarn obtained by false twisting polyamide black original yarn is 8.82 mN x indicated dtex and a frame circumference of 1.125 m is measured. A 200-fold casserole was prepared with a machine, dried with a hot air dryer (105 ± 2 ° C. × 60 minutes), and the fineness was calculated from the value obtained by weighing the casserole weight with a balance and multiplying by the official moisture content. The measurement was performed 4 times, and the average value was defined as the fineness. Moreover, the value which divided the obtained fineness by the number of filaments was made into the single fiber fineness.
F. Strength, Elongation Polyamide black original yarn, and false twisted yarn sample formed by false twisting of polyamide black original yarn are JIS L 1013 (chemical fiber filament yarn test method, manufactured by Orientec Corporation TENSILON UCT-100) 2010). The elongation was determined from the elongation at the point showing the maximum strength in the tensile strength-elongation curve. Further, the strength was determined by dividing the maximum strength by the fineness. The measurement was performed 10 times, and the average values were taken as strength and elongation. Note that the gripping interval is 50 cm and the tensile speed is 50 cm / min.
G. Crimping property Five skeins of 10 turns are obtained while applying a tension of 0.098 cN / dtex to a false twisted yarn obtained by false twisting a polyamide black original yarn. Leave in an environment of 20 ° C. and 60% RH for 24 hours. Treated in hot water of 98 ° C. ± 1 ° C. for 20 minutes under a load of 1.76 × 10 ⁻³ cN / dtex (load in water). The heat-treated skein is left to dry in an environment of 20 ° C. and 60% RH for 24 hours. In advance, water is put into the cylinder and left in an environment of 20 ° C. and 60% RH for 24 hours. All the skein is placed in water with the skein sample subjected to an initial load (load in water) of 1.76 × 10 ⁻³ cN / dtex. Thereafter, a load of 0.088 cN / dtex (water load) is further applied to obtain a constant load of 0.08976 cN / dtex (water load), and the skein length a (mm) after 2 minutes is measured. . Immediately remove the constant load and measure the length b (mm) of the skein 2 minutes after the initial load alone. The crimp characteristics are calculated by the following equation and evaluated with an average value of five.

Crimp property (%) = [(ab) / a] × 100
H. Boiling water shrinkage rate While a tension of 0.098 cN / dtex is applied to a false twisted yarn obtained by false twisting a polyamide black original yarn, five skeins of a circumference of 1.125 m are taken. Leave in an environment of 20 ° C. and 60% RH for 24 hours. The initial length L0 is obtained under a 0.09 cN / dtex load. Next, it is treated in boiling water under no load for 30 minutes and then air-dried. Next, the length L ₁ after the treatment is obtained under a 0.09 cN / dtex load, calculated by the following formula, and evaluated with an average value of five.

Boiling water shrinkage ratio (%) = [(L ₀ −L ₁ ) / L ₀ ] × 100
I. Softness The Zocchi Tights sample was evaluated in three stages with respect to the softness (soft texture) according to the feel of the inspector (30 persons) for the lower 10 cm portion of the garter.

a: Soft property equivalent to Comparative Example 7 b: Soft property slightly inferior to Comparative Example 7 c: Soft property greatly inferior to Comparative Example 7 The color of the Zokki Tights sample was determined on the basis of the color (deep black color developability) on the 10 cm part of the lower part of the garter part by visual inspection of 30 persons.

a: deeper black than Comparative Example 7 and very good color b: black and better than Comparative Example 7 c: color equivalent to Comparative Example 7 d: slightly whitish than Comparative Example 7 and poorly colored e: Whiter and poorer in color than Comparative Example 7. Pilling property A 10cm portion of the Zokki Tights sample was subjected to pilling evaluation according to the JIS L 1076 (2012) Appearance and Retention C method to determine the grade.

N: The number of pills is about No. N in the standard photo L: The number of pills is about the No. L in the standard photo M: The number of pills is about the No. M in the standard photo H: The number of pills is the standard photo No. H grade or higher grade. CV of dry heat shrinkage stress (%)
Using FTA-500 manufactured by Toray Engineering Co., Ltd., measurement is conducted for 10 minutes through a dry heat treatment apparatus heated to 100 ° C. with a length of 15.5 cm under conditions of a polyamide filament supply rate of 10 m / min and a relaxation of 1%. The value obtained by dividing the standard deviation of the dry heat shrinkage stress by the average value.
[Example 1]
(Manufacture of polyamide black yarn)
As polyamide, a nylon 6 chip having a sulfuric acid relative viscosity (η _r ) of 2.6 and a titanium oxide content of 0.02% by mass was dried by a conventional method so that the moisture content was 0.03% by mass or less.

The resulting nylon 6 chip is kneaded with a twin-screw kneader so that the furnace method carbon black content is 15% by mass, and after passing through a 30 μm cut filter, the master chip is manufactured by discharging. It dried by the conventional method so that it might become 300 ppm or less of a moisture content. The obtained nylon 6 master chip containing carbon black and nylon 6 chip containing no carbon black were blended at a ratio of 1: 4 (carbon black content in the black original yarn was 3% by mass) and melted at 265 ° C. It was melted at a temperature, passed through a polymer pipe provided with 25 stages of static mixers, filtered through a spin pack provided with a 10 μm cut metal filter, and discharged from a spinneret at a spinning temperature of 260 ° C. As the spinneret, one having 68 holes, a round shape, and one yarn / base was used. After discharging from the spinneret, after cooling and refueling with cold air at 18 ° C., entanglement is performed, and then stretched 1.2 times through the first and second godded rolls at a winding speed of 4,000 m / min. Winding was performed to obtain 96 dtex, 68 filament nylon 6 black original yarn. The obtained black original yarn was evaluated with respect to yarn-making property, carbon black content, carbon black average particle size, fineness, strength, and elongation. The results are shown in Table 1.
(Manufacture of false twisted yarn)
Using the false twisting machine IVF805 manufactured by Ishikawa Seisakusho Co., Ltd., the nylon 6 black original yarn is processed at a processing speed of 500 m / min, a draw ratio of 1.23 times, a heater temperature of 180 ° C., and a D / Y ratio of 1.7 (untwisting). Tension / twisting tension = 1.04), and false twisting was performed to obtain a false twisted yarn of 78.1 dtex and 68 filaments. The fineness, strength, elongation, boiling water shrinkage, and crimp characteristics of the obtained false twisted yarn were evaluated. The results are shown in Table 1.
(Manufacture of covering elastic yarn)
Using the above-mentioned false twisted yarn as a wound yarn, and using “Mobilon” (registered trademark) 22 dtex, G type (manufactured by Nisshinbo Textile Co., Ltd.) as the core yarn, the covering number is 600 T / m, S twist at a draft of 3.0 times, Z Twisted single covering yarn was prepared.
(Manufacture of zock tights)
Zocchi tights were knitted by applying the single covering yarn to MODEL KT-S4 (380 needles) manufactured by Nagata Seiki Co., Ltd. The knitted tights were preset for 10 minutes at a vacuum of 80 ° C., scoured for 30 minutes at 98 ° C., and subjected to a heat treatment at 110 ° C. for 30 seconds with a foot shape of an aluminum plate after softening treatment to obtain zokkito tights. The softness, color, and pilling properties of the sock tights were evaluated. The results are shown in Table 1.
[Example 2]
Nylon 6 black raw material and nylon 6 black tip were blended in a ratio of 1:14 (carbon black content in the black raw yarn was 1% by mass) in the same manner as in Example 1, except that the nylon 6 black raw material was blended in a ratio of 1:14. Yarning was produced. The obtained black original yarn was evaluated with respect to yarn-making property, carbon black content, carbon black average particle size, fineness, strength, and elongation. The results are shown in Table 1.

Using the obtained nylon 6 black original yarn, false twisted yarn, covering elastic yarn, and tights were produced in the same manner as in Example 1. The fineness, strength, elongation, boiling water shrinkage rate, crimp characteristics, softness, color, and pilling properties of the zock tights were evaluated. The results are shown in Table 1.
Example 3
Nylon 6 black raw material in the same manner as in Example 1 except that carbon black-containing nylon 6 master chip and nylon 6 chip were blended at a ratio of 33:67 (carbon black content in the black raw yarn was 5 mass%). Yarning was produced. The obtained black original yarn was evaluated with respect to yarn-making property, carbon black content, carbon black average particle size, fineness, strength, and elongation. The results are shown in Table 1.

Using the obtained nylon 6 black original yarn, false twisted yarn, covering elastic yarn, and tights were produced in the same manner as in Example 1. The fineness, strength, elongation, boiling water shrinkage rate, crimp characteristics, softness, color, and pilling properties of the zock tights were evaluated. The results are shown in Table 1.
Example 4
Nylon 6 black original yarn was produced in the same manner as in Example 1 except that filtration was performed with a spin pack provided with a 15 μm cut metal filter. The obtained black original yarn was evaluated with respect to yarn-making property, carbon black content, carbon black average particle size, fineness, strength, and elongation. The results are shown in Table 1.

Using the obtained nylon 6 black original yarn, false twisted yarn, covering elastic yarn, and tights were produced in the same manner as in Example 1. The fineness, strength, elongation, boiling water shrinkage rate, crimp characteristics, softness, color, and pilling properties of the zock tights were evaluated. The results are shown in Table 1.
Example 5
Nylon 6 black original yarn was produced in the same manner as in Example 1 except that filtration was performed with a spin pack provided with a 20 μm cut metal filter. The obtained black original yarn was evaluated with respect to yarn-making property, carbon black content, carbon black average particle size, fineness, strength, and elongation. The results are shown in Table 1.

Using the obtained nylon 6 black original yarn, false twisted yarn, covering elastic yarn, and tights were produced in the same manner as in Example 1. The fineness, strength, elongation, boiling water shrinkage rate, crimp characteristics, softness, color, and pilling properties of the zock tights were evaluated. The results are shown in Table 1.
Example 6
Nylon 6 black original yarn was produced in the same manner as in Example 1 except that a spinneret having 96 holes and a round one was used, and a nylon 6 black original yarn of 96 dtex, 96 filament was obtained. The obtained black original yarn was evaluated with respect to yarn-making property, carbon black content, carbon black average particle size, fineness, strength, and elongation. The results are shown in Table 1.

Using the obtained nylon 6 black original yarn, false twisted yarn, covering elastic yarn, and tights were produced in the same manner as in Example 1. The fineness, strength, elongation, boiling water shrinkage rate, crimp characteristics, softness, color, and pilling properties of the zock tights were evaluated. The results are shown in Table 1.
[ Reference Example 1 ]
A nylon 6 black original yarn was produced in the same manner as in Example 1 except that a round spinneret hole number of 52 was used, and a nylon 6 black original yarn of 96 dtex, 52 filaments was obtained. The obtained black original yarn was evaluated with respect to yarn-making property, carbon black content, carbon black average particle size, fineness, strength, and elongation. The results are shown in Table 1.

Using the obtained nylon 6 black original yarn, false twisted yarn, covering elastic yarn, and tights were produced in the same manner as in Example 1. The fineness, strength, elongation, boiling water shrinkage rate, crimp characteristics, softness, color, and pilling properties of the zock tights were evaluated. The results are shown in Table 1.
[Example 7 ]
A nylon 6 black original yarn was produced in the same manner as in Example 1 except that a spinneret having a hole number of 68, round, 2 yarns / base was used, and a nylon 6 black original yarn of 48 dtex, 34 filaments was produced. I got a thread. The obtained black original yarn was evaluated with respect to yarn-making property, carbon black content, carbon black average particle size, fineness, strength, and elongation. The results are shown in Table 1.

Using the obtained nylon 6 black original yarn, false twisted yarn, covering elastic yarn, and tights were produced in the same manner as in Example 1. The fineness, strength, elongation, boiling water shrinkage rate, crimp characteristics, softness, color, and pilling properties of the zock tights were evaluated. The results are shown in Table 1.
[Example 8 ]
A nylon 6 black original yarn was produced in the same manner as in Example 1 except that a spinneret having a number of holes of 78, round, 3 threads / cap was used, and a nylon 6 black original yarn of 43 dtex, 26 filaments was produced. I got a thread. The obtained black original yarn was evaluated with respect to yarn-making property, carbon black content, carbon black average particle size, fineness, strength, and elongation. The results are shown in Table 1.

Using the obtained nylon 6 black original yarn, false twisted yarn, covering elastic yarn, and tights were produced in the same manner as in Example 1. The fineness, strength, elongation, boiling water shrinkage rate, crimp characteristics, softness, color, and pilling properties of the zock tights were evaluated. The results are shown in Table 1.
[Example 9 ]
As polyamide, a nylon 66 chip having a sulfuric acid relative viscosity (ηr) of 2.8 and a titanium oxide content of 0.02% by mass was dried by a conventional method so that the water content was centered at 0.11% by mass.

  The obtained nylon 66 chip is kneaded so that the furnace method carbon black content is 15% by mass, and a master chip is manufactured by installing a filter of 30 μm cut, so that the moisture content is centered at 0.11% by mass. Dried. The obtained carbon black-containing nylon 66 master chip and nylon 66 chip were blended at a ratio of 1: 4 (carbon black content in the black original yarn was 3% by mass) and melted at a melting temperature of 290 ° C., Nylon 66 black original yarn was produced in the same manner as in Example 1 except that it was filtered through a spin pack equipped with a 10 μm cut metal filter and discharged from the spinneret at a spinning temperature of 290 ° C., and 96 dtex, 68 filaments were produced. Nylon 66 black original yarn was obtained. The obtained black original yarn was evaluated with respect to yarn-making property, carbon black content, carbon black average particle size, fineness, strength, and elongation. The results are shown in Table 1.

  Using the obtained nylon 66 black original yarn, false twisted yarn, covering elastic yarn, and tights were produced in the same manner as in Example 1 except that the heater temperature for false twisting was set to 190 ° C. The fineness, strength, elongation, boiling water shrinkage rate, crimp characteristics, softness, color, and pilling properties of the zock tights were evaluated. The results are shown in Table 1.

[Comparative Example 1]
Nylon 6 black original yarn was produced in the same manner as in Example 1 except that filtration was performed with a spin pack provided with a 1 μm cut metal filter. The obtained black original yarn was evaluated with respect to yarn-making property, carbon black content, carbon black average particle size, fineness, strength, and elongation. The results are shown in Table 2.

Using the obtained nylon 6 black original yarn, false twisted yarn, covering elastic yarn, and tights were produced in the same manner as in Example 1. The fineness, strength, elongation, boiling water shrinkage rate, crimp characteristics, softness, color, and pilling properties of the zock tights were evaluated. The results are shown in Table 2.
[Comparative Example 2]
Nylon 6 black original yarn was produced in the same manner as in Example 1 except that filtration was performed with a spin pack provided with a 30 μm cut metal filter. The obtained black original yarn was evaluated with respect to yarn-making property, carbon black content, carbon black average particle size, fineness, strength, and elongation. The results are shown in Table 2.

Using the obtained nylon 6 black original yarn, false twisted yarn, covering elastic yarn, and tights were produced in the same manner as in Example 1. The fineness, strength, elongation, boiling water shrinkage rate, crimp characteristics, softness, color, and pilling properties of the zock tights were evaluated. The results are shown in Table 2.
[Comparative Example 3]
Nylon 6 black original yarn was produced in the same manner as in Example 1 except that the spinneret hole number was 320 and a round one was used to obtain 96 dtex, 320 filament nylon 6 black original yarn. The obtained black original yarn was evaluated with respect to yarn-making property, carbon black content, carbon black average particle size, fineness, strength, and elongation. The results are shown in Table 2.

Using the obtained nylon 6 black original yarn, false twisted yarn, covering elastic yarn, and tights were produced in the same manner as in Example 1. The fineness, strength, elongation, boiling water shrinkage rate, crimp characteristics, softness, color, and pilling properties of the zock tights were evaluated. The results are shown in Table 2.
[Comparative Example 4]
A nylon 6 black original yarn was produced in the same manner as in Example 1 except that a round spinneret hole number of 20 was used, and a nylon 6 black original yarn of 96 dtex, 20 filaments was obtained. The obtained black original yarn was evaluated with respect to yarn-making property, carbon black content, carbon black average particle size, fineness, strength, and elongation. The results are shown in Table 2.

Using the obtained nylon 6 black original yarn, false twisted yarn, covering elastic yarn, and tights were produced in the same manner as in Example 1. The fineness, strength, elongation, boiling water shrinkage rate, crimp characteristics, softness, color, and pilling properties of the zock tights were evaluated. The results are shown in Table 2.
[Comparative Example 5]
The same method as in Example 1 except that a nylon 6 master chip containing carbon black and a nylon 6 chip are blended at a ratio of 3:97 (carbon black content in the black original yarn is 0.5 mass%). Nylon 6 black original yarn was produced. The obtained black original yarn was evaluated with respect to yarn-making property, carbon black content, carbon black average particle size, fineness, strength, and elongation. The results are shown in Table 2.

Using the obtained nylon 6 black original yarn, false twisted yarn, covering elastic yarn, and tights were produced in the same manner as in Example 1. The fineness, strength, elongation, boiling water shrinkage rate, crimp characteristics, softness, color, and pilling properties of the zock tights were evaluated. The results are shown in Table 2.
[Comparative Example 6]
Nylon 6 black raw material in the same manner as in Example 1 except that carbon black-containing nylon 6 master chip and nylon 6 chip were blended in a ratio of 47:53 (carbon black content in the black raw yarn was 7% by mass). Yarning was produced. The obtained black original yarn was evaluated with respect to yarn-making property, carbon black content, carbon black average particle size, fineness, strength, and elongation. The results are shown in Table 2.

Using the obtained nylon 6 black original yarn, false twisted yarn, covering elastic yarn, and tights were produced in the same manner as in Example 1. The fineness, strength, elongation, boiling water shrinkage rate, crimp characteristics, softness, color, and pilling properties of the zock tights were evaluated. The results are shown in Table 2.
[Comparative Example 7]
As polyamide, only a nylon 6 chip having a sulfuric acid relative viscosity (η _r ) of 2.6 and a titanium oxide content of 0.02% by mass was used (carbon black content was 0% by mass). Nylon 6 yarn was produced by the method described above. The obtained nylon 6 yarn was evaluated for the yarn-making property, fineness, strength, and elongation. The results are shown in Table 2.

  Using the obtained nylon 6 yarn, false twisted yarn and covering elastic yarn were produced in the same manner as in Example 1. In addition, zokkito tights were knitted as in Example 1. The knitted zock tights were preset at a vacuum of 80 ° C. for 10 minutes, refined at 98 ° C. for 30 minutes, and dyed under the conditions of Mitsui Nylon Black GL (Mitsui Toatsu Chemical Co., Ltd.) 4 mass%, 98 ° C. for 60 minutes. After the flexible treatment, a heat-resistant set of 110 ° C. × 30 seconds was applied to the foot of an aluminum plate to obtain a zock tight. The fineness, strength, elongation, boiling water shrinkage rate, crimp characteristics, softness, color, and pilling properties of the zock tights were evaluated. The results are shown in Table 2.

From the results of Table 1 (Examples 1 to 9 ), the polyamide black raw yarn of the present invention has a soft texture (softness) by optimizing the carbon black content, average particle diameter, and single fiber fineness, It can be seen that deep black color (color) and durability (pilling) can be obtained. It can be seen that in Example 9, the use of nylon 66 resulted in a slight reduction in yarn breakage during yarn production compared to nylon 6. Thereby, when it was set as the leg knit, the fluff of the original yarn was mixed, and the product quality was slightly lowered.

  In Comparative Example 1, due to the presence of carbon black having a small average particle size, the dynamic friction coefficient on the surface of the tights was high, and the pilling property was poor.

  In Comparative Example 2, the presence of carbon black having a large average particle size resulted in a large increase in the filtration pressure in the spinning pack, not only shortening the pack life, but also causing frequent yarn breakage and inferior yarn forming properties. It was. Further, the strength of the obtained nylon black original yarn was as low as 1.5 cN / dtex, and the pilling property was slightly inferior.

  In Comparative Example 3, the single fiber fineness was thin, the yarn breakage occurred frequently, and the spinning property was inferior, and the pilling property was inferior.

  In Comparative Example 4, the single fiber fineness was thick, the texture was hard, and the soft texture (softness) was inferior.

  In Comparative Example 5, since the carbon black content was small, light was easily transmitted and the color became whitish, and the color (deep black color development) was inferior.

  Comparative Example 6 was a result of not only a large increase in the filtration pressure in the spinning pack due to a high carbon black content and a short pack life, but also frequent yarn breakage and poor yarn production. Further, the strength of the obtained nylon black original yarn was as low as 0.9 cN / dtex, and the pilling property was slightly inferior.

Comparative Example 7 is a conventional zock tights, which is black dyed. Although a soft texture was obtained, it became whitish due to diffused reflection of light and was inferior in color (deep black color development).
Since the Zokki tights using the polyamide black original yarn of the present invention are not black dyed, the processing cost of the dyeing process can be omitted, the cost can be reduced, and the environmental load is reduced.

  The polyamide black original yarn of the present invention has a soft texture and can produce a deep black color. A processed yarn obtained by false twisting and a covering elastic yarn covered with an elastic yarn can be preferably applied to stockings or tights.

Claims (5)

A polyamide black original yarn containing 1 to 5% by mass of carbon black, wherein the average particle size of the carbon black in the polyamide is 1 to 20 μm and the single fiber fineness of the polyamide black original yarn is 0.8 to 1.7 dtex. There is a polyamide black original yarn whose polyamide is mainly composed of nylon 6 or whose main component is nylon 66. A polyamide black raw yarn having a CV value of dry heat shrinkage stress of 4.0% or less of the polyamide black raw yarn according to claim 1. A false twisted yarn obtained by false twisting the polyamide black original yarn according to claim 1 or 2. A covering elastic yarn using the polyamide black original yarn according to claim 1 or 2 or the false twisted yarn according to claim 3 as a wound yarn. A leg knit using at least one of the polyamide black original yarn according to claim 1 or 2, the false twisted yarn according to claim 3, and the covering elastic yarn according to claim 4 as at least a part of the leg portion.