JPS62191510A - Multifilament yarn - Google Patents

Abstract

PURPOSE:The titled yarn having improved fastness to dyeing, polyamide syn thetic multifilament yarn comprising filaments having a sectional area ratio of thick part and a thin part of a specific value and difference in crystallinity between the thick part and the thin part of < a fixed value. CONSTITUTION:The aimed filament yarn having thick and thin parts, which is synthetic fiber multifilament yarn of polyamide such as nylon 6, nylon 66, etc., having sectional area changing in the longer direction and a sectional area ratio of thick part and thick part of >=1.2, >=35% crystallinity at the thick and the thin parts, <5% difference in crystallinity between the thick and the thin parts, smal0l color difference of shade at the thick part and the thin parts, improved fastness to dyeing, neither elongating nor changing even under excess tension in knitting and weaving processes.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention has three individual filaments with a thick part and a detail, and when dyed by weaving and weaving, there is little difference in shade between the thick part and the detail, and the dyeing is fast. The present invention relates to a multifilament yarn that has excellent elasticity and is not deformed by excessive tension during the weaving and weaving process, resulting in no defects such as weft steps or warp lines when knitted.

(Prior Art) Conventionally, multifilament yarns made of thick and thin polyester filaments have been disclosed in Japanese Patent Application Laid-Open No. 103523/1983;
Japanese Patent Publication No. 51-7207, Japanese Patent Publication No. 55-16930
These yarns are produced in a variety of types, ranging from those whose thick portions and details are uniform in phase between each filament, to those whose thick portions and details are relatively or completely irregular.

(Problems to be Solved by the Invention) However, the conventional yarns as described above have a strong color difference between the thick part and the details, which greatly limits their uses. For example, in a yarn whose thick part and details are aligned in phase between each filament, 5 surface changes are overemphasized due to the shading color difference in addition to the morphological changes in the thick part and details, whereas in a yarn with 1 phase out of alignment. They all had a heathered tone with a strong difference in shade and shade, and all had a distinctive appearance. Therefore, although these yarns are relatively easy to use for self-bleaching and printing purposes, they are difficult to use for dyeing purposes. moreover,
These yarns are undrawn or semi-drawn with a low crystallinity in their thick portions, so they are easily elongated by excessive tension during the weaving and weaving process.

When these fabrics are made into fabrics, they tend to have defects such as weft and warp striations, and in order to eliminate these defects, special tension management is required, making them extremely difficult to handle. In addition, since these threads are usually dyed with disperse dyes, unlike the dyeing mechanism in which the dye is dyed to bifunctional groups, the color fastness is low, and the thick parts with low crystallinity are easily dyed darkly. However, since the drawing dye easily comes out, the color fastness is further reduced.The present invention solves the above-mentioned drawbacks of conventional yarn, and its purpose is to An object of the present invention is to provide a multifilament yarn made of filaments having a thick part and fine details with little difference in shade between the thick part and the fine details, excellent color fastness, and not being stretched and deformed even under excessive tension in the weaving and weaving process. .

(Means for Solving the Problems) As a result of intensive research in order to eliminate the drawbacks of the above-mentioned conventional yarns, the present inventors have developed a multilayer yarn made of filaments of polyamide synthetic fibers having specific physical properties in thick parts and details. The present invention was achieved by discovering that the above-mentioned drawbacks could be overcome by using filament yarn.

That is, the present invention provides a polyamide synthetic fiber multifilament yarn composed of filaments with a ratio of the cross-sectional area of the thick part to the cross-sectional area of the details of 1.2 or more, and the crystallinity of the thick part and the details of the filaments is Both are 35% or more,
The gist of the invention is a multifilament yarn characterized in that the difference in crystallinity between the thick part and the details is less than 5%.

Two aspects of the present invention will be described in detail below.

Firstly, each filament constituting the multifilament yarn of the present invention must have a cross-sectional area that changes in the longitudinal direction, and the ratio of the cross-sectional area of the thick part to the cross-sectional area of the details must be 1.2 or more. It is. In the present invention, in the case of a yarn whose phase between filaments is relatively uniform, thick or thin is emphasized, giving the woven or knitted fabric irregularities due to differences in shape such as slab-like, and yarns whose phase between filaments is uneven are emphasized. In the case of , gentle unevenness and particularly deep color tones can be obtained due to the difference in the form of thread mottling, but if the ratio of the cross-sectional area of the thick part of the filament to the cross-sectional area of the details is not 1.2 or more, the thick and thin parts will be emphasized. It is not possible to give a shape with uneven thickness or a deep color tone.

There is no particular upper limit on the ratio of the cross-sectional area of the thick part of the filament to the cross-sectional area of the fine parts, but if this ratio becomes too large, the passability of the subsequent process such as weaving and weaving may decrease, or the resulting fabric may become Since there is a possibility that the wear resistance may be lowered, a value of about 1 or less is usually preferred.

Here, the cross-sectional area of the filament is determined by taking out the filament from the multifilament yarn, photographing the thick section and the detailed cross section with an optical microscope, and calculating the area ratio on the photograph. If the filament has a circular cross section, use an optical microscope to determine the diameters of the thick part and the details, and then calculate the ratio of the squares of these diameters.

This can be replaced.

Secondly, the multifilament yarn of the present invention is made of polyamide synthetic fiber, and the crystallinity of the thick part and the small part of the filament are both 35% or more, and the difference between the crystallinity of the thick part and the small part is 5%. %.

Polyester fibers are dyed using dyes such as disperse dyes, which simply adsorb the dye between the molecules, but in this case, the dye molecules move in and out relatively easily, resulting in low color fastness. Furthermore, the difficulty of adsorbing dye molecules is determined by the arrangement of the nine molecules, the crystalline state, etc., and the difference in color between light and shade tends to become strong. In order to improve color fastness and reduce the difference in shade.

Polyamide fiber threads, on which dyes and polymer functional groups act, are effective. As the dye that dyes the functional groups of polyamide, it is preferable to use an anionic dye such as an acid dye or a cationic dye.

However, even for yarns that have functional groups that can be dyed with these dyes, the dyeing density is not determined only by the amount of functional groups, but also the degree of crystallinity has a large effect on the dyeing density. In other words, the difficulty of dyeing changes depending on the degree of swelling of the yarn in the dye bath, the density of the fiber structure, etc., so if there is a large difference in crystallinity between the thick part and the fine part of the filament, the functional groups Even if the dye is used for dyeing, the color difference between light and shade will be strong in these areas.

Therefore, in order to suppress the difference in shade and obtain good color fastness, multifilament yarn made of polyamide synthetic fiber, which is a highly crystalline polymer with a relatively dense structure, is suitable. Both crystallinity is 35%
It is necessary to do the above. If the crystallinity is less than 35%, even if the difference in crystallinity between the thick part and the small part of the filament is small, a difference will appear in the degree of swelling, and the difference in color between light and dark will be strong due to the difference in dye adsorption, and the dye molecules will Since it is relatively easy to get in and out, color fastness tends to be low.

In addition, the difference in crystallinity between the thick part and the fine part of the filament was calculated by 5
It is necessary to make it less than o/Q. Even if the degree of crystallinity between the thick part and the details is 35% or more, if the difference between the crystallinity between the thick part and the details is 5% or more, the crystallinity will be low and the difference in light color will be strong, so this is preferable. do not have.

In the present invention, the degree of crystallinity is calculated from a quadratic equation by measuring the density using the density gradient tube method.

1 Xc 1-Xc d dCd.

However, Xc: Crystallization rate [Crystallinity; 100Xc (%)]
d; Density of measurement sample (g/cn?) d e i Density of completely crystalline part (g/cn) d3; Density of completely amorphous part (g/c+Il) Here, in the case of nylon 6, dc= 1.230g/cl, d,,=1.0
84g/c+a is used.

In the present invention, it is possible to easily visually check whether the multifilament yarn has a small difference in shade on the dyed fabric or not, but one method for evaluating it numerically is the fluctuation range of the FYL value described below. It may also be expressed in R (%).

The variation range R (%) of the FYL value was measured using a commercially available continuous dyeing degree measuring device FYL-500 (manufactured by Toshi), and the test yarn was placed in this FYL value measuring device for 20 m. Measurements are made by running at a speed of /min. Suminol Fast Blue G (manufactured by Sumitomo Chemical) was used as the dye, 0.5% ow
Stain under normal pressure with f. This FYL value is continuously drawn on the recorder every 20 m of yarn length, and this is repeated 5 times, each 20 m.
The difference x8 between the maximum FYL value and the minimum FYL value between yarn lengths of m is determined. The average value R of these five XlO values is the fluctuation range R (%) according to the present invention.

If the fluctuation range of the FYL value exceeds 5%, the color difference between light and shade becomes strong, which is not preferable. That is, in one aspect of the present invention, it is preferable that this fluctuation range is less than 5%.

Next, an example of the method for manufacturing the multifilament yarn of the present invention will be described.

First, the birefringence Δn is 15 X 10-' to 25 X 1
A polyamide synthetic fiber multifilament undrawn yarn with a crystallinity of less than 35% is heat treated at a low elongation rate or overfeed to increase the crystallinity with little increase in birefringence. By subjecting each filament to necking by cold drawing at room temperature, a yarn consisting of the thick and thin filaments of the present invention can be obtained.

As mentioned above, increasing the crystallinity by heat treating low-oriented polyamide multifilament yarns
The molecules in the amorphous part are incorporated into the spherulite structure with almost no increase in orientation, taking a slight a-axis orientation, and when this is cold-stretched at room temperature, the crystal tends to take the c-axis orientation in response to stress. However, due to the increase in crystallinity and crystal size, this crystal rotation cannot be performed smoothly, preventing uniform stretching, and necking occurs mainly in areas that are relatively susceptible to stress concentration. It is thought that this occurs, and as a result, a thick part and a fine part are formed in each filament. Therefore, in order to obtain the multifilament yarn of the present invention, it is necessary to increase the degree of crystallinity in a state of low orientation.

Next, an example of the manufacturing process of the multifilament yarn of the present invention will be explained based on FIG.

The undrawn polyamide multifilament yarn 2 pulled out from the spool 1 is fed to a heat treatment area by a feed roller 3, where it is heat treated by a heating device 4, and then transferred to delivery rollers 1 to 5 and a drawing roller. 6 at room temperature, and a winding device 7.
It is rolled up by.

The polyamide synthetic fiber multifilament yarn applicable to the present invention includes nylon 6, nylon 66°, nylon 6
10 or aromatic polyamide, etc.
In short, any synthetic fiber multifilament yarn made of a polymer having an amide group may be used.

(Function) Since the multifilament yarn of the present invention is made of polyamide fiber, it has excellent color fastness. Moreover, the crystallinity of the thick part and the details of the filament are both 35% or more, and the difference between the crystallinity of the thick part and the details is less than 5%, so the crystallinity is high and the thick part is less than 5%. There is little difference in the degree of crystallinity between the thick part and the details, and there is little difference in shade between the thick part and the details. moreover,
It has a high degree of crystallinity (there is little difference in the degree of crystallinity between the thick part and the details, so this, together with the fact that it is made of polyamide fiber, contributes to good color fastness. Since the is high, the initial elastic stress becomes high and elongation of the yarn under excessive tension is suppressed.

Furthermore, the multifilament yarn of the present invention can provide an extremely deep color tone when it is an irregular yarn in which the thick portions and details of the filaments are assembled in a random phase. The reason for this is not clear, but it is thought to be of the first order. In other words, for fabrics that are knitted and woven from threads consisting of thick filaments and filaments with a uniform diameter without details and then dyed, the incident light is visually perceived as white specularly reflected light and colored diffusely reflected light. It is felt and has a fleshy tone.

Due to the presence of thick parts and details of the filament, the multifilament yarn consists of
The amount of specularly reflected light of the incident light is small, and the amount of diffusely reflected light is large. This diffusely reflected light is reflected and refracted several times in the multifilament thread, which is made up of filaments with thick parts and details, and the optical density is improved because the surface reflected light that is perceived as absorbed vision is reduced. You can get a deep color tone. Furthermore, the ratio of the cross-sectional area of the thick part and the detail is 1
．． Since it is composed of two or more filaments, yarns in which the phase of the thick part and the details are aligned between each filament will produce a thick and thin effect such as a slab, while yarns in which the two phases are not aligned will have a gentle yarn unevenness. Gives a tonal surface change.

(Example) Next, one embodiment of the present invention will be specifically explained using an example. In the following examples, the friction fastness is JIS-L-0849.
Furthermore, the washing fastness was measured in accordance with JIS-L-0844.

Example 1 Birefringence 21.5 x 10-3. Crystallinity 33.3% (
Nylon 6 multifilament undrawn yarn 193d/12f with a density of 1.1254 g/cnT) was heat-treated and cold-stretched under the processing conditions shown in Table 1 according to the processing steps shown in Fig. 1, so that the apparent thickness of the thread became longitudinal. Large thin thread 8 that changed direction
6d/12f was obtained. In addition, when the yarn after heat treatment was collected and its birefringence and crystallinity were measured, the birefringence was 23.2X.
10-', crystallinity 42.7% (density 1.1390g/
c).

Table 1 The obtained large fine yarns were woven into a plain weave with a warp density of 103 threads/2.54 cm and a weft thread density of 88 threads/2.54 cm, and the dye was acidic dye Suminol Fast Blue G (manufactured by Sumitomo Chemical).
It was dyed and finished using 0.5 owf. The obtained fabric had an uneven appearance with little difference in shade and light color. The rubbing fastness and washing fastness of this fabric were both grade 5. In addition, during weaving, the multifilament yarn of the present invention was wound in a tube with a tension of 40 g -1,4-, but there was no elongation deformation due to excessive tension during tube winding, and fabric defects such as weft steps and warp lines were observed. There was no.

Example 2 Birefringence 22.3 x 1.0-', crystallinity 34.2%
(density 1.1266 g/cJ) nylon 6 multifilament undrawn yarn 267d/24f was heat-treated and cold-stretched under the processing conditions shown in Table 2 according to the processing steps shown in Fig. Multifilament yarn 120d, which is a yarn with fine details and irregular phase, with little change in the yarn diameter in the longitudinal direction, and with little unevenness
/12 f was obtained. In addition, when the yarn after heat treatment was collected and the birefringence and crystallinity were measured, the birefringence was 24.8 x 1
0-+, crystallinity, 7% (density 1.1.375 g
/ cJ).

Table 2 The obtained multifilament yarns have a warp density of 92/2.
It was woven to a 2/2 twill structure with a weft density of 84 threads/2.54 cm, and dyed using the acid dye Suminol Milling Red R3 (manufactured by Sumitomo Chemical) 1.5% OWF.

After finishing, there were no strong irregularities on the surface of the fabric.

A fabric with a deep color tone with inconspicuous heathering and faint thread spots on the weft was obtained.

The rubbing fastness and washing fastness of this fabric were both grade 5. Further, during weaving, two multifilament yarns of the present invention were wound into a tube at a tension of 50 g, and there was no elongation deformation due to excessive tension during tube winding, and there were no fabric defects such as two weft steps or warp lines.

(Effects of the invention) As described above, the multifilament yarn of the present invention has
Although the filament is composed of a filament having a thick part and details, there is little difference in shade between the thick part and the details of the filament, and it also has excellent color fastness. Furthermore, it does not elongate and deform due to excessive tension during the weaving process or the preparation process for weaving, making it possible to obtain a woven or knitted fabric without any defects without special process control.

As mentioned above, there is little difference in shade between the thick part and the details of the filament, so in a yarn where the thick part and the details are in phase with each filament, the change in two tones will be gentle, and the thick part of the yarn will Only the detailed form changes are emphasized, and the surface changes are not overemphasized like in conventional yarn (also, yarns with one phase that is not aligned do not have a heathered tone with two strong shading color differences). , it is possible to create a fabric with a mixture of gentle shading.

[Brief explanation of drawings]

FIG. 1 is a process schematic diagram showing one embodiment of the method for manufacturing a multifilament yarn of the present invention.

Claims (1)

[Claims] (1) A polyamide synthetic fiber multifilament yarn composed of filaments with a ratio of the cross-sectional area of the thick part to the cross-sectional area of the details of 1.2 or more, and the crystallinity of the thick part and the details of the filaments are both 35%. A multifilament yarn having the above characteristics and characterized in that the difference in crystallinity between the thick part and the details is less than 5%.