JPS5876522A - Preparation of crimped elastic fiber - Google Patents

Abstract

PURPOSE:To obtain crimped elastic fibers having improved elastic recovery, dimensional stability and fitting property, by subjecting a polyurethane elastomer and a polyamide to the composite spinning, heat-treating the resultant flat composite fibers, and heat-treating the fibers in a heated fluid nozzle under relaxed conditions. CONSTITUTION:A polyurethane elastomer (U) and a polyamide (A) are subjected to the composite spinning to give side-by-side or eccentric sheath-core type fibers of flat cross section having the center of gravity on the major axis, which are drawn and then heat-treated at room temperature -120 deg.C, and further heat- treated in a heated fluid nozzle jetting a hot fluid at 80-150 deg.C under relaxed conditons of <=10% to give the aimed crimped elastic fibers having <=22% shrinkage in boiling water.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a composite fiber of polyurethane elastomer and polyamide, and relates to a method for producing a composite fiber that utilizes both the elasticity due to fine winding and the elasticity of the elastomer itself. , 4IK, by drawing and heat-treating the undrawn yarn obtained by melt-spinning both of the above components into a specific shape 11, a crimped elastic fiber with superior elastic recovery, good dimensional stability, and high fitting properties is obtained. There is TotoK.

In general, elastic thread made of 100% polyurethane has only rubber elasticity, and its elongation reaches 400-SOO%, making it difficult to use as it is, so as a method to suppress the elongation to 200-300%, urethane elastic thread Add crimped yarn or flat yarn to -l or double KII! ! #Wearing,
A so-called covering thread is used. However, the urethane yarn used in such covering yarns is obtained by a wet spinning method or a dry spinning method, and is inferior in productivity compared to the melt spinning method. The cost increases because a covering process is added. Moreover, the bulkiness of crimped yarn cannot be expected from covering yarn, and the rubber part of socks,
Currently, it is only used in special fields that only require stretch properties, such as some sports clothing.

On the other hand, in order to overcome the drawbacks of such covering yarns, one component with different heat shrinkability is laminated into a side-pie-side type or an eccentric sheath core type, which has latent crimp ability, and polyurethane is used as one component. Composite fiber using elastomer and polyamide as the other component (Japanese Patent Publication No. 55-367
No. 25, Special Publication No. 55-27175) has been proposed.

Such composite fibers are fine, have many crimps, and have excellent crimp performance, so they are used in fields where crimp elasticity is required, such as pantyhose. However, these composite fibers using polyurethane elastomer utilize the heat shrinkability of polyurethane elastomer,
Although effective in producing fine crimps, the elasticity (rubber elasticity) of polyurethane elastomer itself is rarely utilized. In other words, although these composite fibers use urethane elastomer, which itself exhibits elasticity, they only utilize crimped fibers in the form of associated fibers.
No attention has been paid to the use of the above-mentioned 1 elasticity' or to the synergistic use of crimp and elasticity to achieve high stretch.

As a result of intensive studies to eliminate such conventional drawbacks, the present inventors have found that by bonding polyurethane elastomer and polyamide in a specific composite state, and then applying stretching, relaxation heat treatment, and K, the properties and elasticity due to crimp are improved. The present inventors have discovered that it is possible to obtain crimped elastic fibers at low cost that have the rubber elastic properties unique to elastomers in addition to the properties of elastomers.

On the contrary, the present invention provides a method for manufacturing a side-pie-side type or eccentric sheath core type crimped composite fiber in which one of the components is a polyurethane elastomer and the other component is a polyamide, by composite melt spinning of both components. After drawing and heat-treating the undrawn yarn obtained by The continuous tree yield rate of 2
This is a method for producing crimped elastic fibers characterized by adjusting the content to 2% or less.

Conditions ■～■ ■The cross-sectional shape of the composite fiber is flat, and one core of each component is present on the major axis passing through the center of gravity of the cross-section ■Heat treatment temperature after stretching: Vine temperature ~ 120°C (1) Heated fluid temperature: 280-150°C (9) Relaxation rate during slow heat treatment: 10% or less The present invention will be explained in more detail. The present inventors have investigated the yarn structure of an elastic yarn with the most stretchability, which can utilize both the elasticity due to crimping and the rubber elasticity due to the elastomer, for composite wound pongee fibers made of polyurethane elastomer and polyamide.
a @ defeated. As a result, we found that the most preferable structure is a rutted fiber structure in which the front surface is cocoon-shaped or oval, and both components are bonded together so that one core of both components is located on the long axis. Ta.

That is, the composite crimped fiber having such a cross-sectional shape is
At the beginning of the expansion, as shown in Figure A, there is a fill-like crimped IIK, but as the expansion progresses, the crimps are extended, and eventually, as shown in Figure 4, nylon is formed around the expanded urethane as a core component. It becomes a spirally wound state, a so-called screw structure state. Furthermore, when the yarn in this state is stretched, the spiral knife (see FIG. 4C) will eventually become completely stretched. In this process, the elasticity of the elastomer dominates until the screw structure is formed, and the rubber elasticity of the elastomer dominates until the screw structure loses its helix.

Elastic yarns that have such flesh elasticity and are suitable for clothing applications satisfy all of the above-mentioned conditions 1 to 2, and have high raw sintering properties only when the resulting crimped yarn has a continuous string retention rate of 22% or less. It can be manufactured under the

In the present invention, the polyurethane elastomer, which is one of the components, must be able to be melt-spun, and usually has a melting point of 200 to 240°C and a hardness of JIS K-6301K.
(Measurement) of 90 to 10G can be used. The other component, polyamide, includes nylon 6, nylon 66°, nylon 610. Nylon 11. Nylon 1
2° nylon 13 or the like can be used. It is necessary to select a combination of these peripheral components that have good compatibility and adhesion so that the peripheral components do not peel off during spinning, processing, and fabric-making processes.

From this point of view, it is preferable to use cablactone-based or polycarbonate-based polyurethane as the polyurethane elastomer. Incidentally, in order to improve the light resistance of these elastomers and polyamides, a light resistance improver such as a penzophenol-based compound, a benzotriazole-based compound, or an inorganic manganese compound may be added.

The conditions (1) to (2) mentioned above will be explained in detail. What is most important in the present invention is that the cross-sectional shape of the obtained fibers is flat as shown in 11th A, ρ, and 8, and that the center of gravity of each component is on the major axis of the cross-section. It is. A crimped fiber having such a cross-sectional shape can have the above-mentioned screw structure, and can best utilize the elasticity due to crimping and the rubber elasticity due to the elastomer.

In addition, the preferred degree of flattening is such that the ratio (a/b) of the length of the major axis passing through the center of gravity of the cross section is a) and the length of the minor axis is b) is in the range of 1.2 to 4. It is more preferable to have the same amount in consideration of the texture, etc. of the woven or knitted fabric.

In contrast to such a flat shape, if the cross-sectional shape is circular as shown in Figure 2 A and -, even if crimp development occurs sufficiently as shown in Figure 4 2, the screw structure as shown in Figure 4 E The rubber elasticity of the elastomer becomes weak and the elasticity of the elastomer cannot be fully utilized, making it impossible to obtain the elastic thread quality that is the object of the present invention.

A spinneret for obtaining a composite fiber having such a fiber cross-sectional shape by melt spinning is used to separately discharge a polyurethane elastomer component (referred to as U component) and an amide component (referred to as A component), immediately after the spinneret surface. A cap that joins at one point, for example the cap shown in FIG. 3, is suitable. Third
1 is a partially vertical side view showing an example of a spinneret.

The U component and the A component are each introduced into the introduction hole 1.3 and are discharged through the discharge hole S4, but at this time, the above-mentioned a/
b can be adjusted.

The composite fiber that is the object of the present invention has j as a3 to tLl, and θ
A sufficient amount can be obtained by adjusting the value within the range of 8 to io''.

The ratio of the area of the U component to the area of the A component in the cross section of the fiber is the dyeing strength of the obtained crimped fiber.

The range of ast-ts is preferable from the elongation 9 modulus of elasticity, etc.
It can be adjusted more easily by changing the discharge amount of the circumferential component.

In order to make the thus obtained composite spun yarn into a flexible elastic fiber that can utilize both the crimp elasticity due to fine crimping and the rubber elasticity of the elastomer itself, which is the object of the present invention, It is important that the following conditions be satisfied when the obtained spun yarn is heat treated after drawing and subjected to relaxation heat treatment using a heated fluid nozzle.

First of all, it is necessary that the submerged shrinkage rate of the crimped yarn obtained after the relaxation heat treatment be 22% or less. The pivot rate of this crimped yarn is 22% thick, which results in poor weaving and manufacturing properties, and is also unfavorable in terms of dimensional stability of the product. In the case of continuous tree shrinkage, the heat treatment temperature after stretching is low, or the heating fluid fh degree is 1
However, as long as the L# post-pressing heat treatment temperature and heated fluid temperature are within the range of conditions described below, it is optically possible to keep the submerged shrinkage rate to 22% or less.

The heat treatment temperature after such stretching is from room temperature to 120° C.22% or less, which improves dimensional stability and decreases the crimp rate, making it impossible to obtain desirable crimp elasticity. Incidentally, the stretching temperature is from the temperature at which the film is stretched to 60°C.

Further, the fluid temperature of the heated fluid nozzle needs to be 80 to 150°C. When the fluid temperature drops to 80° C., the heat shrinkage rate decreases, but the elongation increases and it becomes easy to stretch, and the crimp rate decreases, making it impossible to obtain desirable crimp elasticity. As the fluid used here, air or steam is preferable, and air is particularly preferable since it is less noisy.

Incidentally, the heated fluid nozzle is a nozzle conventionally used for relaxation heat treatment, such as the Japanese Patent Publication No. 45-375.
No. 76, Jikko No. 46-1635, Special Publication No. 56-373
The nozzle described in No. 39 can be used.

Next, the relaxation rate during relaxation heat treatment with a heated fluid nozzle was set to 10
% or more, especially preferably 10% or more and 40% or less. This is because the winding rate varies greatly depending on the relaxation rate during the relaxation heat treatment, so in order to obtain a free moving yarn with the desired crimp rate (crimp elasticity), the relaxation rate must be set within the above-mentioned range K11i! It is important to At this time, the relaxation rate is 10%, and the winding ratio of the end-type carbon fiber Hti' is also low, making it impossible to obtain a winding yarn having the crimp elasticity that is the object of the present invention. In addition, this relaxation rate is determined by the following formula.

Relaxation rate (%) 100 The drawing ψ heat treatment step for producing such a spun yarn may be a so-called kairi method, which is separated from the spinning, or a so-called dependent method, which is directly connected to the spinning. In history, there is the so-called DTY method, which directly connects the stretching and relaxation heat treatment processes, and the so-called 5D method, which directly connects the spinning, stretching, and relaxation heat treatment processes.
The TY method may be used, and any of these methods can be adopted.

As explained above, according to the present invention, polyurethane elastomer and boria! By treating side-by-side type or eccentric J-type 7 type composite spun yarn in which a specific bonded type IIK is formed with a double-sided bonded yarn under the above-mentioned drawing and relaxation heat treatment conditions of Φ~・, fine thrusting It is possible to obtain a crimped elastic fiber that can utilize both the crimped elasticity of the elastomer and the rubber elasticity of the elastomer itself. As a result, excellent crimped conjugate fibers can be obtained which have unprecedented high elasticity and elasticity at high elongation, making them extremely useful for pantyhose, stretch woven and knitted fabrics, and the like.

The present invention will be illustrated below with reference to Examples. The crimp rate (TC), water-saving shrinkage rate (Fs), stretch rate, stretch recovery rate, crimp elasticity modulus, and rubber elasticity modulus used here were measured by the following methods.

l) Change the crimp rate ('re) to the water-saving shrinkage rate (Fs). Take the yarn after relaxation heat treatment into a skein and set the initial load to 21 to 9/d.
A load of o is applied, and the length of the skein after 1 minute is lo. Next, a crimp treatment is carried out for 20 minutes in monoboiling water while an initial load is applied, and then natural drying is carried out under that load day and night. Next, apply a total load of 2001Q/d@, read the length after 1 minute (1,), then remove the load, shade the initial load 1 again, and read the length after 1 minute (lρ, a rate (TC),
Calculate the water saving shrinkage rate (Fs) using the following formula.

2) Measurement of expansion/contraction rate and expansion/contraction recovery rate was performed by spooling the yarn after relaxation heat treatment, applying an initial load of 2 my/do, subjecting it to crimp development treatment for 20 minutes in a continuous tree, and then applying the initial load. Samples that had been air-dried for a day and night were tested at a temperature and humidity of 2°±2°C and 65±2 SRH, and the threads were suspended in the following manner.

A, Test yarn length: 200 ■ (yarn length under initial tension), 2 ■/d under initial tension C, Test load: 5, 10, 20, 50, 100°20
0.500.10G0,1500IIg/de (suspend each load on the lower end of the thread so as not to rotate) 2. Loading time = 3 minutes E) After charging, measure the strain length and apply the initial tension of the unloaded wire.

After applying initial tension, measure the residual strain after 3 minutes.

G. Calculation of the elongation iIA rate and elongation recovery rate is based on the following formula.

Stretching times * rate (%) 3) Thrust elastic modulus, rubber elastic modulus The crimp development treatment system obtained in the same manner as in 2) was applied to a tensile tester type 1 tensile tester, and the central part of the sample was measured using a 20x casetometer. I evaluated it while watching it. The conditions at this time are sample light 2
01. The initial load is 12~/de+extension speed 100%/min, chart speed 20α/min, and the cassettemeter is started by focusing on the central part 101 of the sample. The degree of elongation of this crimped yarn until it becomes the above-mentioned screw structure is the crimped elastic modulus. Furthermore, the helix disappears when it is elongated, and the degree of elongation from the state of the screw structure until the helix disappears is the elastic modulus of the rubber. Measurement is 5
I took the mean time.

Examples Nylon 6 with an intrinsic viscosity [η] of 1.1 (measured with m-cresol liquid at 30°C) and a polyurethane elastomer component were commercially available thermoplastic polyurethane Elastran) i:595 (Cub-Cresol). Type) and Elastolan E995 (carbonate type) (both manufactured by Nippon Elastran ■) were used. 247℃ for nylon 6, 228℃ for polyurethane E595, and 230℃ for E995.
The mixture was melted separately in KIN, heated to 245° C., and composite spun using a side pie-side die as shown in FIG. composite*
The area ratio U/A of polyurethane and polyamide in the cross section # is set to 1 by adjusting the discharge ratio of each component, and the cross sectional shape is the shape shown in Figure 1 A, and a / b is as shown in Figure 3. It was set to 1.5 by adjusting j and θ of the cap.

°Additionally, the obtained spun yarn was coated with 06il of silicone oil.
A quantity of the yarn was attached to form an undrawn yarn of 100 denier/12 filaments.

The resulting undrawn yarn is then wound up and stretched in a separate process.
Tests were conducted using a DTY method in which the relaxation heat treatment step was directly connected, or a 5DTY method in which all the drawing and heat treatment steps were directly connected without winding the obtained undrawn yarn. On this occasion,
Stretched so that the elongation after stretching is 25 to 35 inches, and then treated at various temperatures and degrees, directly connected and passed through a heated air nozzle at a pressure of 9/mG to a pressure of 1.0. The compressed air temperature and relaxation rate were varied. Table - IK spinning, vine stretching, processing conditions, and physical properties of the obtained crimped yarn are also shown.

Furthermore, using a normal side-pie-side type cap, the second
The results of spinning as shown in Figure A are also shown in Table IK.

N1-4srl that meets the conditions of the present invention as shown in Table-1
&17~9. Nn12-13 has a crimp modulus of 85-x
2s%, the rubber elastic modulus is 35-80%, and the total elastic modulus is as high as 120-200%, and the elasticity recovery rate under the L01//do load is 80 inches or more, providing good stretch and recovery properties. %Kf%rtm in terms of dimensional stability.
It was possible to provide an extremely large amount of elasticity. On the other hand, Nn 5 whose heat treatment temperature or heating and compressed air temperature after stretching is higher than the range of the present invention
+Nn 1'O and 1l lower than the relaxation rate of the present invention
Itt had a good diving shrinkage rate, but its crimp elasticity and rubber elasticity were low, and its stretch recovery rate was not good at 80% or less.

Also, if the heating and compressed air temperature is low as in IV & 16, crimp, q
The side-pie-side cross-sectional shape shown in Figure A cannot have a sufficient screw structure when stretched, so the rubber elastic modulus is small.
It did not have powerful stretching performance.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing an example of the composite fiber of the present invention, Fig. 2 is a cross-sectional view showing an example of a conventional composite fiber, and Fig. 3 is a spinning yarn used when spinning the gantry fiber of the present invention. FIG. 4 is a side sectional view showing one example of the cap, and FIG. 4 is a side view of the crimpable elastic fiber of the present invention. U represents a polyurethane elastomer, and A represents a polyamide component. Further, i indicates the center of gravity in the fiber transverse direction, a indicates the length of the major axis passing through the center of gravity i, and b indicates the length of the minor axis passing through one core i. Figure 1 A, 0. /,. Lee, mouth. Procedural amendment (formality) March 1980 Commissioner of the Japan Patent Office 1 Indication of the case Patent application No. 174427/1983 2 Name of the invention Process for manufacturing crimped elastic fibers 3 Person making the amendment Relationship to the case Patent Applicant 1-11 Minamihonmachi, Higashi-ku, Osaka (300) Teijin Limited Representative Tomoo Tokusue (1) Page 19 of the specification, lines 2 to 11 are deleted. (2) Page 21 of the specification is amended as follows. [4, Brief description of the drawings #I1 is a cross-sectional view showing an example of the composite fiber of the present invention, the second
The figure is a cross-sectional view showing an example of a conventional composite fiber, Figure 3 is a side cross-sectional view showing an example of a spinneret used when spinning the composite fiber of the present invention, and Figure W44 is a crimped elasticity of the present invention. FIG. 3 is a side view of the fiber. U indicates a polyurethane elastomer, and Mu indicates a polyamide component. In addition, 1 is the center of gravity of the fiber cross section, a
b represents the length of the major axis passing through the center of gravity 1, and b represents the length of the minor axis passing through the center of gravity i. Patent Applicant Teijin Ltd. Agent Patent Attorney Former 1) Junhiro
Up

Claims (1)

[Scope of Claims] (In the production of a side-fist pie-side type or eccentric sheath-core type wound composite fiber in which one of the ti components is a polyurethane elastomer and the other component is a polyamide, the above-mentioned two components are combined. The undrawn yarn obtained by melt spinning is stretched and
After the heat treatment, a relaxing heat treatment is performed using a heated fluid nozzle, and at that time, the spinning and heat treatment are carried out so that the following conditions (1) to (3) are satisfied. A method for producing crimped elastic fibers, characterized in that: l1IIi. Conditions ■～■ ■The shape of the cross section of the composite fiber is flat, and the center of gravity of each component is on the major axis passing through the center of gravity of the cross section.■Heat treatment temperature after drawing: room temperature to 120℃■Heating Fluid temperature: 80-150℃ ■ Relaxation rate during relaxation heat treatment: xo% or less