JPS62231012A - Super modified cross-section fiber - Google Patents

Abstract

PURPOSE:The titled cross-section fibers which are thermoplastic synthetic fibers having the cross-sectional shape consisting of many branches elongating from the central part and having a specific fineness of each fiber and aspect ratio and rich in dry feeling and with permanent set in fatigue, etc., removed. CONSTITUTION:Cross-section fibers which are thermoplastic synthetic fibers, e.g. polyethylene terephthalate, obtained by spinning and drawing 1 polyamide with preferably >=3.4 relative viscosity, more preferably a polyester with >=0.7 intrinsic viscosity, having a cross-sectional shape of each fiber 1 consisting of 3-5 branches 2 radially elongating from the central part and satisfying formulas I and II (De is the fineness of each fiber; A is the length of the above- mentioned branches 2 in the radial direction; B is the average transverse width of the above-mentioned branches 2; A/B is the aspect ratio of the above- mentioned branches 2). The above-mentioned aspect ratio is preferably >=4.0, more preferably >=4.5.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a super irregular cross-section fiber made of a thermoplastic polymer and having excellent gloss and feel. It can be used for any purpose as long as it can be used effectively.

[Prior Art] Numerous proposals and innovations have been made to make synthetic fibers, especially polyester fibers, come close to the excellent texture of various natural fibers. Among them, silk-like threads have a significantly high added value, so A great deal of research is underway.

For example, the cross-sectional shape of a single yarn is made into a trilobal irregular cross-section to improve gloss, the fineness of a single yarn is made thinner to give it drape properties, or the yarns mentioned above are used to give different shrinkage mixed fibers. Threads, pears, and fabrics with fluff and softness added to the surface are widely known. In this way, proposals have been made to bring the optical and physical properties of synthetic fibers, such as sliminess and rigidity, to the excellent properties of real silk by using spinning and post-processing techniques. Silk-like yarns that partially exceed the performance have also been developed.

However, such conventionally known silk-like threads still have drawbacks.

In other words, among the types of real silk, the silk-like thread mentioned above is a silk-like thread that resembles the texture of so-called domestic silkworms, and when made into fabric, it has rich luster, drapability, and excellent warmth and fluffiness. It is extremely desirable as a fashion material from autumn to winter, but on the other hand, as a material from spring to summer, it feels too hot, especially in midsummer, even though the material is the same, it has a metallic luster, I had no choice but to accept the unfavorable evaluation of slimy feel and 1 heavy feeling.

[Problems to be Solved by the Invention] As mentioned above, in the development of silk-like thread, careful consideration is required to adapt to various trends and seasonal changes, and silk-like fabrics must be flexible.

Several studies have been conducted so far, focusing on the viscosity and shape of the yarn, or the polymers that give it a dry feel and lightness, but none of them were necessarily satisfactory.

For example, when we changed the cross-sectional shape of the yarn from the usual 3-lobed to 6-lobed or 8-lobed yarn to give a dry feel, we found that as the number of protrusions increased, the slimy feeling disappeared, and although it was slightly Although it gives a dry feel, there are problems in that the large number of protrusions inhibits light reflection, resulting in dullness when dyed.

Therefore, using alkali weight loss technology, polyester mixed with fine particles of inorganic or organic compounds is made into yarn, and after being made into fabric, the inorganic or organic compounds in the yarn are eluted with an alkaline solution, and the surface of the yarn is Create fine elution holes,
A method of imparting a dry feeling through the unevenness has been considered.

When this alkali treatment method is used, the dry feeling when the fabric is slid with a fingertip is considerably improved due to the fine irregularities on the thread surface, but the fine irregularities suppress the reflection of light and cause the fabric to dry. The disadvantage is that the gloss disappears completely.

In addition, by eluting inorganic or organic compounds in polyester with an alkaline solution, countless fine elution pores are generated on the yarn surface, so the weight loss rate due to the potassium solution on the yarn surface becomes fast, resulting in excessive weight loss. Another drawback is that the fabric tends to become loose.

On the other hand, if the weight loss time using an alkaline solution is shortened in order to eliminate this sagging, weight loss spots will occur and the quality will deteriorate. Furthermore, for example, attempts have been made to increase the viscosity of the polymer to obtain fibers with extremely irregular cross-sections that have less set, but conventional techniques have the disadvantage that they are only able to achieve a single yarn denier of more than 10 deniers, making them unsuitable for clothing. there were.

Therefore, the inventors of the present invention have conducted various research aimed at solving the above-mentioned drawbacks of conventional synthetic fibers, such as slimy feeling, dullness of dyeing, and tendency to sag. In addition, we have succeeded in creating a synthetic fiber that does not cause dyeing problems and is less sticky.

[Means for Solving the Problems] The thermoplastic synthetic fiber of the present invention that achieves the above object is composed of 3 to 5 branches, where De is the single filament fineness and A is the length of the branches in the radial direction. , where B is the average width of the branch and A/B is the aspect ratio of the branch, 0.5d≦De≦10d and 3.0
The gist is that both conditions of ≦A/B are satisfied.

[Operations] Conventional deformed synthetic fibers having 3 to 5 branches have a relatively short length A in the radial direction of the branch portions 2, as shown in the cross-sectional shape in Figure 2. Length A of the extending branch 2
When we measured the ratio of the average width B of branch 2 and the average width B (average from B1 to B□8) [expressed as aspect ratio (A/B)] for many examples, we found that it was only about 0.7 or less. Do you get it. Further research into this point has revealed that the sliminess of the fabric is caused by the small aspect ratio. That is, if the aspect ratio (A/B) is less than 3.0, a slimy feeling will appear strongly, and the gloss and feel of natural fibers cannot be obtained. Therefore, the present inventors focused on the aspect ratio, and as a result of devising the ratio to be 3.0 or more, they were able to obtain a synthetic fiber with a metallic luster and a smooth texture (dry feel). . Also, the aspect ratio is 4
．． It was found that when the value is 0 or more, the dry feel becomes even stronger, and when it is 4.5 or more, the fiber is optimal for texture and feel.

However, the fineness of single fibers (sometimes called single yarn fineness) is 0.
．． If it is less than 5 d (denier), the strength of the single fiber will be significantly reduced, causing practical problems;
If it is larger than d, it becomes difficult to knit or weave it for clothing, and the characteristics of the fiber of the present invention cannot be fully enjoyed. In order to more effectively bring out the characteristics of the fibers of the present invention, *the fineness of the TA fibers is preferably 0.5 d or more and 8 d or less;
The optimal range is 0.5 d or more and 7 d or less.

[Example 1] Figure 1 shows the cross-sectional shape of a single fiber 1 in a typical synthetic fiber of the present invention, which has three branches 2 extending radially from the center. It becomes thinner little by little as you move away from it (toward the tip). The cross-sectional shape of the single fiber 1 in the synthetic fiber according to the present invention is not limited to the above embodiment, and as shown in FIGS. 3(a) to 3(c), the number of branches 2 is from 3 to 5. Alternatively, the width of the branch 2 may be the same as the actual branch from the base to the tip.

Further, the thermoplastic polymer used as the material of the synthetic fiber is not particularly limited, and the following are listed as representative examples. That is, polyesters represented by polyethylene terephthalate, polybutylene terephthalate, polymethylene terephthalate, etc., polycaprolactam,
Polyamides such as polyhexamethylene adipamide, polyhexamethylene sebaamide, polytetramethylene adipamide, etc.; polyamides such as polypropylene, polyethylene, polybutene-1, polyoxymethylene, etc.
α-olefins, polyvinyl alcohol, etc. are used. These thermoplastic polymers may contain matting agents, pigments, light stabilizers, heat stabilizers, antioxidants, antistatic agents, dyeing improvers, adhesion improvers, etc. to improve the properties of the fibers of the present invention. They can be mixed freely as long as they do not cause any serious adverse effects.

To calculate the aspect ratio of branch 2 shown in Fig. 1, the width at the base of the center side B wax to the width at the tip B + mln
The average width B up to and the length A from the root to the tip are used. However, in order to set the aspect ratio to 3.0 or more, it is necessary to maintain the strength of the single fiber at a level that does not cause any practical problems, and this is also important from the viewpoint of maintaining accuracy when manufacturing the spinning nozzle. This is an important requirement. In addition, in order to spin fibers with branch aspect ratios of 3.0 or more, it is necessary to increase the viscosity of the polymer material used as the dope. In this case, the general intrinsic viscosity (described in detail later) that is considered necessary for spinning clothing fibers is insufficient and it is difficult to maintain the cross-sectional shape of the fiber. 0.
7 or higher must be used.

The intrinsic viscosity of polyester is measured by the following method. i.e. 75% by weight p-chlorophenol and 25% by weight
The polymer is dissolved in a mixed solvent consisting of tetrachloroethane at room temperature, and the viscosity is measured at 30° C. using an Ostwald-Fens capillary viscometer.

Intrinsic viscosity is the limit value at which the natural logarithm of the ratio of solution viscosity to solvent viscosity divided by the concentration of the polymer solution in grams of polymer per 100 ml of solution approaches zero concentration.

Furthermore, when polyamide, which is mainly composed of polycabramide, is used as a material, it is difficult to maintain the shape with the general relative viscosity (described in detail later) that is conventionally considered necessary, and it is difficult to obtain the fiber of the present invention. It is preferable that the relative viscosity is 3.0 or more.

The relative viscosity of polyamide is measured by the following method.

That is, 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 Long/ml, and drop it on ice at a temperature of 20°C ± 0.05°C. Measure the relative viscosity of the solution using an Ostwald viscometer with 6-7 seconds. During the measurement, the same viscometer was used, and the falling time To (seconds) of 20 ml of sulfuric acid was the same as when preparing the sample solution, and the falling time T of 20 ml of the sample solution was measured.
From the ratio of I (seconds), the relative viscosity RV is calculated using the following formula.

RV=T, /T0 When spinning the above-mentioned high viscosity polymer material, the pressure strength of the spinning machine should be increased from the usual 300 kg/am” to 50 kg/am”.
It is necessary to raise it to 0 kg/CI2 or more, and more preferably to 1000 kg/0m2 or more. Furthermore, when the spun yarn is subjected to drawing heat treatment to obtain the ultra-irregular cross-section yarn of the present invention, it is preferable to use a non-contact type heater for drawing.

Polyethylene terephthalate having an intrinsic viscosity of 1.0 and 0.6 was spun using a nozzle shaped as shown in FIG. 3(a). The branch length A of the spinning nozzle was 0.9 mm, the width B was 0.1 mm, a spinneret with 18 nozzles was used, and the spinning temperature was 290°C.

After spinning under the conditions of a spinning speed of s o m/min, a discharge rate of 18 g/min, and a cooling air speed of 0.5 m/sec,
Using a 100 cm non-contact slit heater at 200° C., a yarn with a fineness of 100 d was obtained with 1.8 filaments.

The obtained yarn is woven into habutae, and this fabric is subjected to processing such as spinning, presetting, alkali weight loss, and dyeing to produce a plain dyed fabric of the same color. I made a comparison. The results are shown in Table 1.

First, nylon 6 having an IU main relative viscosity of 4.0, 3.5, and 2.5 was spun and drawn under almost the same conditions as in Experimental Example 1 (however, the spinning temperature was 280°C). The yarn thus obtained was woven and post-processed in the same manner as in Experimental Example 1 to obtain plain dyed habutae fabrics, and each was evaluated. The results are shown in Table 2.

[Effects of the Invention] The synthetic fibers of the present invention have properties very similar to natural fibers, making it possible to obtain fabrics that are full of dryness and eliminate drawbacks such as curling and dyeing problems.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing a cross section of a single fiber according to the present invention, Fig. 2 is an explanatory diagram showing a cross section of a conventional single fiber, and Figs. 3 (a) to (c).
FIG. 2 is an explanatory diagram showing another embodiment of the present invention.

Claims (1)

[Scope of Claims] (1) A thermoplastic synthetic fiber, in which the cross-sectional shape of a single fiber consists of 3 or more and 5 or less branches extending radially from the center, and has the following formula (a) or (ro). ) A super irregular cross-section fiber that satisfies the following. 0.5d≦De≦10d...(a) 3.0≦A/B...(b) However, De is the single yarn fineness, A is the length of the branch in the radial direction, and B
is the average width of the branch, and A/B is the aspect ratio of the branch. (2) The ultra-irregular cross-section fiber according to claim 1, which has an aspect ratio (A/B) of 4.0 or more. (3) The ultra-irregular cross-section fiber according to claim 2, which has an aspect ratio (A/B) of 4.5 or more. (4) The ultra-irregular cross-section fiber according to any one of claims 1 to 3, wherein the single fiber fineness (De) is within the range of 0.5d≦De≦8d. (5) The ultra-irregular cross-section fiber according to claim 4, wherein the single fiber fineness (De) is within the range of 0.5d≦De≦7d. (6) The thermoplastic synthetic fiber is obtained by spinning and drawing polyamide having a relative viscosity of 3.4 or more.
The super irregular cross-section fiber according to any one of Item 5. (7) Claim 1 in which the thermoplastic synthetic fiber is obtained by spinning and drawing polyester having an intrinsic viscosity of 0.7 or more.
The ultra-irregular cross-section fiber according to any one of items 1 to 5.