[Technical Field]

The present invention relates to a metachromatic combined nylon filament yarn comprising at least two types of fiber groups respectively having different dye affinities, and more specifically, relates to a combined nylon filament yarn that provides a unique mottled appearance and functions such as warmth-retaining and lightweight for clothes created using the yarn. [Background art]

Textiles created using combined filament yarns that comprise a plurality of synthetic fiber filaments respectively having different dye affinities are, when dyed, provided with unevenly dyed areas which result in mottled appearances, and therefore, a variety of proposals have conventionally been made.

To produce a yarn for textile with a mottled appearance, for example, Japanese Unexamined Patent Application Publication No. 1 1-158745 and Japanese Unexamined Patent Application Publication No. 10-219535 disclose methods of producing mottled fibers by knotting a multifilament yarn formed of two or more filaments of different dye affinities or color tones, however both methods are problematic in that they lack any sort of specialty as apparel products for the poor contrast in hues of their mottled appearances. Moreover, the cycles of hues that present the mottled appearances are very uneven, and accordingly so is their product quality.

Japanese Unexamined Patent Application Publication No. 2006-161 189 discloses a method of producing a mottled cloth, by drawing together and weaving two or more yams having different dye affinities, however, the cycle of mottles produced by this method is big, making the mottled appearance look artificial, and the cloth does not have specialty as an apparel product.

Japanese Unexamined Patent Application Publication No. 2002-317345 discloses a method of producing a mottled cloth from a yam using a polyamide filament and another fiber and having the Uster-tested unevenness of 5 to 20%, and the proposed combined filament yam can produce textiles with mottled or salt-and-pepper appearances, however, unevenness in the thickness of fibers is too much in the clothes, and therefore, their texture becomes coarse, while the functions of clothes such as coloring properties, airtightness, and windbreak performance are greatly degraded. [Problems to be Solved by Invention]

An object of the present invention is to provide a nylon fiber with a mottled appearance having coloring properties, lightweight properties and softness better than the afore-mentioned conventional art, and also provide a combined nylon filament yarn that maintains functions of produced clothes such as airtightness and windbreak performance.

[Means for Solving Problems]

To achieve the above object, the nylon fiber of the present invention comprises any one of the following structures.

(1) A combined nylon filament yarn comprising at least two types of nylon fiber groups to be mixed, wherein the fiber groups forming the combined nylon filament yarn include at least one type of an anionic-dyeable fiber and at least one type of a metachromatic nylon fiber; and the number of twists of the combined filament yarn is 6 to 17 times/m, and its number of knots is 15 to 30 knots/m.

(2) The combined nylon filament yarn of (1), wherein the difference in the number of amino end groups of the at least two types of fiber groups forming the fiber is 3 ^x 10-5 mol/g or more.

(3) The combined nylon filament yarn of (1) or (2), wherein its U% that represents unevenness in the thickness in the lengthwise direction is 1.5% or lower.

[Description of Embodiments]

Now, the present invention will be explained in detail.

To obtain a mottled appearance, a mottled nylon fiber of the present invention must comprise at least two types of fiber groups respectively having different dye affinities, the fiber groups including at least one type of an anionic-dyeable nylon fiber and, among other fibers, at least one type of a metachromatic nylon fiber, and creating or dyeing a woven or knitted fabric using this nylon fiber provides a cloth having a natural mottled appearance, and therefore, the nylon fiber can be used for a wide variety of fashion materials for outdoor gears, sports gears, underclothes, etc.

A fiber for providing a mottled appearance is preferably a warmth-retaining function, soft texture, coloring property, etc. Here, polyamide in the present invention is a polymer, where a so-called hydrocarbon group is attached to the main chain by amide bond, and preferably, its types are, though not limited to, polyamides mainly including polycaproamide or polyhexamethylene adipamide for their good dye affinities, washing fastness, machine characteristics. Here, "mainly" means that the capramide unit or hexamethylene adipamide unit is 80 mol% or higher, and more preferably 90 mol% or higher. Other components may be for example, though not limited to, units of aminocarboxylic acid, dicarboxylic acid, diamine, etc. that are monomers forming polydodecanoamide, polyhexamethylene adipamide, polyhexamethylene azelamido, polyhexamethylene sebacamide, polyhexamethylene dodecanoamide, polymetaxylene adipamide, polyhexamethylene terephthalamide, polyhexamethylene isophthalamide, etc. Moreover, as may be necessary, any light stabilizer, heat stabilizer, antioxidant, antistatic, end group adjusting agent, dye affinity augmenting agent, etc. may be added. Also, a delusterant such as titanium oxide is preferably added.

An anionic-dyeable polyamide multifilament is a multifilament formed of a so-called common polyamide including an amino end group. The anionic-dyeable polyamide multifilament can be dyed with acid dye, reactive dye, metallized dye, etc. On the other hand, a metachromatic polyamide multifilament means a polyamide multifilament that can be dyed with any dyes except for anion dye (except for disperse dye), and an example of such polyamide multifilament preferably used is a so-called cationic-dyeable polyamide multifilament which can be dyed with cationic dye by introducing a sulfone group. Here, a method of introducing a sulfone group is copolymerization upon polymerizing a polyamide, where sodium 5- sulfoisophthalic acid, its diester, sodium 3-carboxybenzene sulfonate, sodium 3,5- dicarboxybenzene sulfonate, or their lithium salt, etc. is added. Also, the cationic-dyeable polyamide multifilament can be dyed with a cationic dye. To obtain a cloth with a clearly- contrasted mottled appearance, the difference in the number of amino end groups that represents the number of anion-dyed fibers needs to be large to some extent. Specifically, the difference in the number of amino end groups of the anionic-dyeable nylon fiber and that of the metachromatic nylon is preferably 3>< 10-5 mol/g or more. To stably regulate the physical properties such as operability when spinning each fiber group, and stretchability and strength of fibers for clothing fibers, the relative viscosities (nr) of the fiber material chips are preferably 2.0 or more and 3.5 or less.

Considering durability or texture, each fiber group is preferably selected from multifilaments of the yarn fineness of 10 to 150 denier and the single-yarn fineness of 0.5 to 10 denier. The ratio of fineness of the respective fiber groups that form a metachromatic combined filament yarn and their ratio of single-yarn fineness may be adjusted according to the desired form of the mottled appearance, however, the ratio of fineness between the anionic-dyeable fiber and the metachromatic nylon is preferably 1 :5 to 5:1 , and the ratio of single-yarn fineness between the anionic-dyeable fiber and the metachromatic nylon is preferably 1 :5 to 5: 1, for their combining.

If the fiber groups that form the metachromatic combined nylon filament yarn of the present invention are uniformly mixed, there will be no clear differences in the dyed color, accordingly nor a mottled appearance. On the other hand, if not mixed enough, the fiber groups do not combine well with each other, causing bits of fluff, lines, etc. in the process of weaving or knitting, and the appearance quality of the resulting cloth is reduced. Moreover, if the pattern to mix the fiber groups is a repetitive one, the mottled appearance will be too artificial to provide natural mottled appearances expected for clothing fibers, while if the pattern is completely random, the cycle of mottles becomes too unbalanced, and the mottled appearance on the whole cloth loses its cohesiveness and appearance quality. Therefore, to obtain a readily-processable cloth with a clear and natural mottled appearance, metachromatic fibers are preferably randomly mixed by air nozzle, etc. and then twisted, and more specifically, the number of twists in the fibers is 6 to 24/m, and the number of knots is 15 to 30 knots/m.

The metachromatic combined nylon filament yarn of the present invention is often used for clothing, especially for applications such as tights, underclothes and downshells for which warmth-retaining function is expected, and therefore, the unevenness in the thickness of yarn in the lengthwise direction must be modest for airtightness and tightness of the produced cloth. Preferably U% is 1.5% or lower.

The applications of the metachromatic combined nylon filament yarn are not specially limited, however, applications of directional fiber alignments such as woven, tricot, or circular- knitted fabrics present more preferable mottled appearances. On the other hand, such preferable mottled appearances would not be provided by sewing threads, ornamental lace threads, etc.

Methods of dyeing clothes produced with these applications may be dyeing with an anion dye only to have a mottled appearance with the dyed anionic-dyed nylon and the undyed metachromatic nylon, or dyeing both the metachromatic fiber and the anionic-dyeable nylon to have a mottled appearance.

[Examples]

Now, the present invention will be explained in more detail with reference to the Examples. Note that the characteristic values in the Examples are obtained by the following methods.

A. Relative Viscosity [ητ]

(a) Samples were weighed and dissolved with solutions of 98-weight% concentrated sulfuric acid to obtain sample concentrations (C) of lg/ 100ml. (b) the solutions obtained in (a) measured by Ostwald viscometer, for the number of seconds (Tl) that took for them to fall at 25 °C. (c) The number of seconds (T2) that a 98-weight% concentrated sulfuric acid with no sample dissolved took to fall at 25°C was measured in the same manner as (b). (d) The samples' relative viscosities (nr) with 98% sulfuric acid were calculated by the following formula. The measurement temperature was 25 °C.

(nr)=(Tl/T2)+{ 1.891 ^χ (1.000-C)} .

B. Amino End Group

Polyamide polymers were powdered, and after low-molecular-weight components and fluid were removed if necessary, solutions were prepared by dissolving, by shaking at room temperature, 1 g of the polyamide polymer with 40 to 50 ml of mixed solvents of phenol and ethanol (of the mix ratio of 20 ml of ethanol and 80 g of phenol) and the amounts of 0.02 N hydrochloric acid of the solutions were calculated by neutralizing titration with 0.02 N hydrochloric acid. Also, the amount of 0.02 N hydrochloric acid was calculated by neutralizing titration of only the above-described mixed solvent of phenol and ethanol (of the same amount) with 0.02 N hydrochloric acid. Then, the numbers of amino end groups per 1 g of polyamide polymer were calculated from the difference.

C. Unevenness in the thickness of material yarn in the lengthwise direction (U%)

Eight samples were tested by USTER TESTER III of Zellweger Uster Ltd., with the setting of the sample length of 300 m and the yarn speed of 100 m/minute, for the half inert of 12.5%, to obtain the transitory conditions (UH% value) of uneven fineness in the lengthwise direction of fibers.

D. level of mottled appearance

Tubular knitted fabrics were produced by using drawn fibers of 40D and 40 filament that is circular in cross-section and dyed, and then, the visual organoleptic assessments of the knitted fabric were performed. The assessment results are indicated with oo, o, and ^χ respectively for "Excellent", "Good" and "Poor".

E. Operability

Yarns respectively processed to comprise a standard number of fibers (200) were evaluated for the rate of occurrence of broken threads and fluff.

If the rate of broken threads and fluff was 2% or lower, the yarn was evaluated as o, while if 2% or higher, evaluated as x.

F. Number of knots Measurements were made by Entanglement tester R-2050 of Rothschild Instruments with the setting of the yarn feed speed of 4.0 cm/sec, the yarn feed length of 3.0 cm, the pre-tension of 7.5 g, and the trip tension of 1 1.0 g.

G. Number of twists

Measurements were performed by Maeda-type twist counter of Maeda Seiki Seisakusho with the setting of the yarn length of 50 cm and the load of 4 g.

The metachromatic combined nylon filament yarns of Examples 1 to 5 respectively comprise, among their fiber groups, a fiber A that is a 20 denier, 20 filament drawn fiber prepared by melt- spinning nylon chips of the relative viscosity of 2.55 and the number of amino end groups of 4.48x 10 ^"5 mol/g, and rolling up with the draw ratio of 1.18 times and at the take-up speed of 4480 m/min;

a fiber B that is a 20 denier, 20 filament drawn fiber prepared by melt-spinning nylon chips of the relative viscosity of 2.55 and the number of amino end groups of 1.48x l0 ^~5 mol/g, and rolling up with the draw ratio of 1.18 times and at the take-up speed of 4480 m/min;

a fiber C that is a 20 denier, 20 filament drawn fiber prepared by melt spinning nylon chips of the relative viscosity of 2.55 and the number of amino end groups of 9.48 x l0 ^~5 mol/g, and rolling up with the draw ratio 1.18 times and at the take-up speed 4480 of m/min; and

a fiber D that is a 20 denier, 20 filament drawn fiber prepared by melt spinning nylon chips of the relative viscosity of 2.55 and the number of amino end groups of 6.48x l 0 ^"5 mol/g, and rolling up with the draw ratio of 1.18 times and the take-up speed of 4480 m/min.

Example 1 : A fiber group A and a fiber group B were set up on the creel, and the fiber groups were pulled out from the bobbin by the feed roller at the circumferential velocity of 785 m/min, drawn together by the yarn combining guide, provided with knots by knotting air nozzle at the pressure of 1 kgf/cm2, and then twisted and wound up by the spindle of the ring twister at the rotation speed of 7500 rpm. The obtained 40 denier, 40 filament metachromatic combined nylon filament yam presented U% of 0.3%, the number of knots of 20.9 knots/m, and the number of twists of 6 twists/m.

Then, a tubular knitted fabric was created by using the metachromatic combined nylon filament yam to evaluate its level of mottled appearance and operability, and the fiber was confirmed to present a good level of mottled appearance without harming operability.

Example 2: A fiber group A and a fiber group C were set up on the creel, and the fiber groups were pulled out from the bobbin by the feed roller at the circumferential velocity of 785 m/min, drawn together by the yam combining guide, provided with knots by the knotting air nozzle at the pressure of 1 kgf/cm2, and twisted and wound up by the spindle of the ring twister at the rotation speed of 7500 rpm. The obtained 40 denier, 40 filament metachromatic combined nylon filament yarn presented U% of 0.3%, the number of knots of 20.9 knots/m, and the number of twists of 6 knots/m.

Then, a tubular knitted fabric was created by using the metachromatic combined nylon filament yarn to evaluate its level of mottled appearance and operability, and the fiber was confirmed to present a good level of mottled appearance without harming operability.

Example 3: A fiber group B and a fiber group C were set up on the creel, and the fiber groups were pulled out from the bobbin by the feed roller at the circumferential velocity of 785 m/min, drawn together by the yarn combining guide, provided with knots by the knotting air nozzle at the pressure of 1.0 kgf/cm2, and then twisted and wound up by the spindle of the ring twister at the rotation speed of 7500 rpm. The obtained 40 denier, 40 filament metachromatic combined nylon filament yarn presented U% of 0.3%, the number of knots of 20.9 knots/m, and the number of twists of 6 knots/m.

Then, a tubular knitted fabric was created by using the metachromatic combined nylon filament yarn to evaluate its level of mottled appearance and operability, and the fiber was confirmed to present a good level of mottled appearance without harming operability.

Example 4: A fiber group A and a fiber group B were set up on the creel, and the fiber groups were pulled out from the bobbin by the feed roller at the circumferential velocity of 785 m/min, drawn together by the yam combining guide, provided with knots by the knotting air nozzle at the pressure of 0.5 kgf/cm2, and then twisted and wound up by the spindle of the ring twister at the rotation speed of 7500 rpm. The obtained 40 denier, 40 filament metachromatic combined nylon filament yam presented U% of 0.3%, the number of knots of 15 knots/m, and the number of twists of 6 knots/m.

Then, a tubular knitted fabric was created by using the metachromatic combined nylon filament yam to evaluate its level of mottled appearance and operability, and the fiber was confirmed to present a good level of mottled appearance without harming operability.

Example 5: A fiber group A and a fiber group B were set up on the creel, and the fiber groups were pulled out from the bobbin by the feed roller at the circumferential velocity of 785 m/min, drawn together by the yam combining guide, provided with knots by the knotting air nozzle at the pressure of 2.5 kgf/cm2, and then twisted and wound up by the spindle of the ring twister at the rotation speed of 7500 rpm. The obtained 40 denier, 40 filament metachromatic combined nylon filament yarn presented U% of 0.3%, the number of knots of 30 knots/m, and the number of twists of 6 knots/m.

Then, a tubular knitted fabric was created by using the metachromatic combined nylon filament yarn to evaluate its level of mottled appearance and operability, and the fiber was confirmed to present a good level of mottled appearance without harming operability.

Example 6: A fiber group A and a fiber group B were set up on the creel, the fiber groups were pulled out from the bobbin by the feed roller at the circumferential velocity of 500 m/min, drawn together by the yarn combining guide, provided with knots by the knotting air nozzle the pressure 0.8 kgf/cm2, and then twisted and wound up by the spindle of the ring twister at the rotation speed of 8000 rpm. The obtained 40 denier, 40 filament metachromatic combined nylon filament yarn presented U% of 0.3%, the number of knots of 25.3 knots/m, and the number of twists of 1 1 knots/m.

Then, a tubular knitted fabric was created by using the metachromatic combined nylon filament yarn to evaluate its level of mottled appearance and operability, and the fiber was confirmed to present a good level of mottled appearance without harming operability.

Example 7: A fiber group A and a fiber group B were set up on the creel, and the fiber groups were pulled out from the bobbin by the feed roller at the circumferential velocity of 300 m/min, drawn together by the yam combining guide, provided with knots by the knotting air nozzle at the pressure of 0.8 kgf/cm2, and then twisted and wound up by the spindle of the ring twister at the rotation speed of 8000 rpm. The obtained 40 denier, 40 filament metachromatic combined nylon filament yam presented U% of 0.3%, the number of knots of 30.2 knots/m, and the number of twists of 17 knots/m.

Then, a tubular knitted fabric was created by using the metachromatic combined nylon filament yam to evaluate its level of mottled appearance and operability, and the fiber was confirmed to present a good level of mottled appearance without harming operability.

Comparative Example 1 : A fiber group A and a fiber group D were set up on the creel, and the fiber groups were pulled out from the bobbin by the feed roller at the circumferential velocity of 785 m/min, drawn together by the yam combining guide, provided with knots by the knotting air nozzle at the pressure of 1.0 kgf/cm2, and then twisted and wound up by the spindle of the ring twister at the rotation speed of 7500 rpm. The obtained 40 denier, 40 filament metachromatic combined nylon filament yam presented U% of 0.3%, the number of knots of 20.9 knots/m, and the number of twists of 6 knots/m. Then, a tubular knitted fabric was created by using the metachromatic combined nylon filament yarn to evaluate its level of mottled appearance and operability, and no mottled appearance was confirmed with this fiber.

Comparative Example 2: A fiber group A and a fiber group B were set up on the creel, and the fiber groups were pulled out from the bobbin by the feed roller at the circumferential velocity of 785 m/min, drawn together by the yarn combining guide, no knot was provided by the knotting air nozzle at the pressure of 0.0 kgf/cm2, and then twisted and wound up by the spindle of the ring twister at the rotation speed of 7500 rpm. The obtained 40 denier, 40 filament metachromatic combined nylon filament yarn presented U% of 0.3%, the number of knots of 6 knots/m, and the number of twists of 6 knots/m.

Then, a tubular knitted fabric was created by using the metachromatic combined nylon filament yarn to evaluate its level of mottled appearance and operability, and the fiber was confirmed to present a good level of mottled appearance, however, its operability was very poor, and so was the appearance quality of the cloth.

Comparative Example 3: A fiber group A and a fiber group B were set up on the creel, and the fiber groups were pulled out from the bobbin by the feed roller at the circumferential velocity of 785 m/min, drawn together by the yam combining guide, provided with knots by the knotting air nozzle at the pressure of 4.5 kgf/cm2, and then twisted and wound up by the spindle of the ring twister at the rotation speed of 7500 rpm. The obtained 40 denier, 40 filament metachromatic combined nylon filament yam presented U% of 0.3%, the number of knots of 50 knots/m, and the number of twists of 6 knots/m.

Then, a tubular knitted fabric was created by using the metachromatic combined nylon filament yarn to evaluate its level of mottled appearance and operability, and the fiber was confirmed to present a good level of mottled appearance, however, its operability was very poor, and so was the appearance quality of the cloth.

Comparative Example 4: A fiber group A and a fiber group B were set up on the creel, and the fiber groups were pulled out from the bobbin by the feed roller at the circumferential velocity of 785 m/min, drawn together by the yam combining guide, provided with knots by the knotting air nozzle at the pressure 1 kgf/cm2, and then twisted and wound up by the spindle of the ring twister at the rotation speed of 5000 rpm. The obtained 40 denier, 40 filament metachromatic combined nylon filament yam presented U% of 0.3%, the number of knots of 20.9 knots/m, and the number of twists of 4 knots/m. Then, a tubular knitted fabric was created by using the metachromatic combined nylon filament yarn to evaluate its level of mottled appearance and operability, and the level of mottled appearance was confirmed not to be good enough, and the operability was very poor, while the appearance quality of the cloth was poor as well.

Comparative Example 5: A fiber group A and a fiber group B were set up on the creel, and the fiber groups were pulled out from the bobbin by the feed roller at the circumferential velocity of 300 m/min, drawn together by the yarn combining guide, provided with knots by the knotting air nozzle at the pressure of 0.3 kgf/cm2, and then twisted and wound up by the spindle of the ring twister at the rotation speed of 10000 rpm. The obtained 40 denier, 40 filament metachromatic combined nylon filament yarn presented U% of 0.3%, the number of knots of 19 knots/m, and the number of twists of 20 knots/m.

Then, a tubular knitted fabric was created by using the metachromatic combined nylon filament yarn to evaluate its level of mottled appearance and operability, and no mottled appearance was confirmed with this fiber.

[Table 1]

[Advantageous Effects of Invention]

The present invention provides a nylon fiber with a mottled appearance having coloring properties, lightweight properties and softness better than the conventional art, and also provides a combined nylon filament yarn that maintains functions of produced clothes such as airtightness and windbreak performance.