JPH0146601B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to stockings with excellent transparency and durability. Conventionally, as thermoplastic synthetic fibers constituting stockings, torque-type or woolly-type false twisted yarns of so-called inelastic thermoplastic synthetic fibers such as nylon 6, nylon 66, and polytetramethylene terephthalate have been used. Transparency, beauty of the knitted surface, and durability are very important characteristics required for stockings. Conventionally, studies have focused on reducing the number of filaments and reducing the total fineness as measures to improve transparency.
Considering the durability when worn, conventional stockings have the following advantages: reducing the number of filaments and reducing the total fineness.
Naturally, there was a limit. That is, transparency and durability were contradictory. Based on the above situation, the inventors of the present invention have developed a stocking that is strong and durable in terms of durability.
If it is less than 70g/y, damage will occur when putting on and taking it off or during long-term continuous use, so it is essential that the strength of knitting yarn for stockings be at least 70g/y. We have found that a total denier of 3 to 13 deniers is an essential requirement. Therefore, by developing a false-twisted yarn made of high-strength polyamide fibers and using this yarn as a knitted yarn for stockings, stockings that have both transparency and durability were obtained. That is, one of the important features of the present invention is that the knitted yarn constituting the stockings is the false twisted yarn of the high-strength polyamide fiber. The present invention provides a polyamide synthetic fiber in which at least the leg portion of the stocking has a relative viscosity of 2.8 or more and less than 3.5, a total fineness of 3 to 13 deniers, a filament count of 1 to 8, and a yarn tenacity of 70.
The stockings are knitted using a false twisted yarn having a g/y or higher knitting yarn as the main knitting yarn. Note that the term "stockings" as used in the present invention refers not only to stockings but also to the stocking part of pantyhose. The present invention will be explained in detail below. The polyamide that is the raw material for the fiber intended in the present invention is
Polymer concentration 10 mg/ml in 96% concentrated sulfuric acid solution at 20°C
Examples of polycaprolactam, polyhexamethylene adipamide, polyhexamethylene sebaamide, copolymers of these polyamides, and 1,
There are polyamides made from condensation products of 4-cyclohexanebis(methylamine) and linear aliphatic dicarboxylic acids. Such polyamides can be blended with matting agents, pigments, light stabilizers, heat stabilizers, antioxidants, antistatic agents, dyeability improvers, adhesion improvers, etc. as necessary. All can be used except those that have a serious adverse effect on the characteristics of the present invention depending on their formulation. The method for manufacturing the knitting yarn used in the stockings of the present invention will be described in more detail. At least the leg portions of the stockings of the present invention are composed of polyamide synthetic fibers having a relative viscosity of 2.8 or more and less than 3.5. That is, the polyamide fibers constituting the stockings of the present invention are obtained by melt-spinning and then drawing polyamides having a high relative viscosity, whereas conventional polyamides have a relative viscosity of at most 2.5. Of course, it can also be produced by a direct spinning/drawing method. If a polyamide with a relative viscosity of less than 2.8 is used, it is very difficult to ensure a yarn tenacity of 70 g/y or more at a total fineness of 3 to 13 deniers, which is an essential requirement of the present invention. Next, a method for manufacturing the polyamide yarn constituting the present invention will be briefly described, but the present invention is not limited to the following method. In producing the polyamide fibers constituting the present invention, the spinning and drawing process, especially the drawing process, is important. That is, for example
When polyamide with RV≧3.0 is melt-spun and the undrawn yarn with a birefringence index of 0.002 to 0.035 is drawn either continuously after spinning or once wound, the undrawn yarn first supply roller and the 100°C The second undrawn yarn maintained below
It is best to apply a preliminary stretching of 1.10 times or less between the supply roller and then perform a first stage stretching of 40% or more of the total stretching ratio between the first stretching roller and the undrawn yarn as necessary. supply second roller and first
A high-temperature pressurized steam jet nozzle is provided between the stretching roller, the nozzle temperature is set to 200° C. or higher, high-temperature steam is spouted, and the stretching point is fixed near the high-temperature pressurized steam jet nozzle. Furthermore, when performing the second-stage drawing, a slit heater (a heating device provided with a slit as a thread running path) with an ambient temperature of 170 to 350°C was installed between the first drawing roller and the second drawing roller. The yarn is heated while running through the slit in a non-contact state (ambient temperature refers to the temperature inside the slit) so that the yarn stays for 0.3 seconds or more, and then the second Provided to stretching rollers. At that time, a temperature gradient is created in the slit heater, so that the atmospheric temperature at the yarn inlet is 160°C or higher and the exit atmospheric temperature is 350°C or lower, and the yarn can stay in an atmosphere of 170 to 350°C for 0.3 seconds or more. It is preferable to allow the thread to pass through the thread. In addition, dimensional stability can be further improved by performing a relaxation treatment of 10% or less at 210 to 150°C after two-stage stretching, either continuously without winding or after winding. It is. The high-strength polyamide fiber obtained by the above method is
False-twisting is performed under normal false-twisting conditions, and conditions similar to those for producing normal knitting yarn for stockings can be selected. The high-strength polyamide fiber yarn that is the knitting yarn for the stockings of the present invention has been described in detail above, but one of the more important requirements of the present invention is that the total fineness of the knitting yarn for the stockings is 3 to 13 deniers. , and the number of filaments is 1 to 8,
It is a false twisted yarn with a yarn tenacity of 70g/y or more. When the number of constituent filaments is 1 to 3, it is a torque type, and when it is 4 to 8, it is a woolly type. When the number of constituent filaments is 1 to 3, the number of snarls is preferably 50 to 1000 pieces/m. Stockings are knitted using the knitting yarn described above, and the knitting method may be circular knitting or full-fledged knitting. Furthermore, in the stockings of the present invention, at least the leg portions are knitted with the knitting yarn made of the above-described high-strength polyamide fiber, but the other portions, that is, the pants portion, the ankle portion, the heel portion, the sole portion, and the toe portion are knitted with the knitting yarn made of the above-described high-strength polyamide fiber. It may be knitted only with knitting yarn, or may be knitted with other yarns depending on the part. Further, the knitting yarn may be interwoven with other fiber yarns. Hereinafter, the configuration and effects of the present invention will be explained with reference to examples, but the present invention is not limited by the following examples. In addition, in the examples,
"Parts" and "%" indicate "parts by weight" and "% by weight" unless otherwise specified. Example 1 Using polycaproamide with a relative viscosity of 3.0 as a raw material,
Spinning and drawing was carried out under the conditions shown in Tables 1 and 2,
A drawn yarn having the quality shown in Table 3 was obtained. Next, false twisting was performed under the following false twisting conditions. False-twisted body: polyurethane friction disk False-twisting temperature: 180°C False-twisting speed: 700 m/min Table 4 shows the physical properties of the obtained false-twisted yarn.

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[Table] Stockings were knitted from the false twisted yarn of Example 1 shown in Table 4 using a 32 gauge knitting machine, and a wear test was performed. As a comparative example, two types of stockings knitted using nylon 6-fiber yarn with a relative viscosity RV of 2.5 were also tested at the same time, and the number of days they lasted and the incidence of tearing were examined. The results are shown in Table 5.

[Table] As is clear from Table 5, although the stockings of the present invention, Example 1, have a fine denier brand, they have a long wear resistance, have a low tearing rate, and have sufficient wear resistance. Moreover, the transparency when worn was overwhelmingly superior to that of the comparative example. The method for measuring the main parameters used to specify the structure and measure the physical properties of the fibers constituting the present invention will be described below. <Relative viscosity measurement method> Prepare a sample solution by dissolving the sample in 96.3±0.1% by weight reagent special grade concentrated sulfuric acid so that the polymer concentration is 10mg/ml, and drop it in water at a temperature of 20℃±0.05℃. Measure the relative viscosity of the solution using an Ostwald viscometer with 6-7 seconds. For measurements, use the same viscometer and use the same 20% sulfuric acid as when preparing the sample solution.
The relative viscosity RV is calculated from the ratio of the falling time T0 (seconds) for ml and the falling time T1 (seconds) for 20 ml sample solution using the following formula. RV=T1/T0 (11) <Measurement method of birefringence (△n)> Nikon polarizing microscope POH type Leitz Beretsk compensator was used, and the light source was a spectral light source activation device (Toshiba SLS-3-B type). ) was used (Na light source). A sample cut at an angle of 45° C. to the fiber axis with a length of 5 to 6 mm is placed on a glass slide with the cut surface facing up. Place the sample slide glass on the rotating stage, adjust the rotating stage so that the sample is at a 45 degree angle to the polarizer, insert the analyzer to make it a dark field, and then turn the compensator on at 30°. Count the number of stripes (n pieces). Turn the compensator clockwise to mark the point at which the sample first becomes darkest (a), and turn the compensator counterclockwise to mark the point at which the sample first becomes darkest (mark b). After measuring (read up to 1/10 scale in both cases), return the compensator to 30, remove the analyzer, measure the diameter d of the sample, and calculate the birefringence (△n) based on the formula below. (average value of 20 measurements). △n=T/d (T=nλo+ε) λo=589.3mμ ε: Obtained from C/10000 and i in the Leitz compensator manual i=(a-b) (: Difference in compensator reading)

Claims (1)

[Claims] 1. At least the leg portion of the stockings is made of polyamide synthetic fiber with a relative viscosity of 2.8 or more and less than 3.5, the total fineness is 3 to 13 deniers, the number of filaments is 1 to 8, and the yarn strength is 70 g/y. Stockings characterized by being knitted using the above-mentioned false twisted yarn as the main knitting yarn.