JPS63282308A - Production of water-soluble crimped vinylon - Google Patents

Abstract

PURPOSE:To easily obtain the titled fiber having excellent crimping property, on an industrial scale at a low cost, by subjecting an undrawn vinylon fiber successively to heat-treatment and drawing treatment at respective specific temperature and carrying out crimp-developing treatment of the resultant latent crimping fiber in a specific atmosphere. CONSTITUTION:A polyvinyl alcohol used as a raw material is extruded from a spinneret by dry-spinning process. The obtained fiber is heat-treated at a temperature higher than the drawing temperature by >=60 deg.C and within 120-230 deg.C and then drawn at a temperature lower than the above heat- treatment temperature by >=60 deg.C and within 20-150 deg.C. The obtained latent crimping fiber is treated in a steam atmosphere of RH 70-100%, in water or in a hot dry atmosphere of 120-230 deg.C to develop the crimp and obtain the objective fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an industrially advantageous method for producing water-soluble crimped vinylon, and more specifically relates to imparting crimping to water-soluble vinylon in a dry spinning method. be.

[Conventional technology]

Water-soluble vinylon is used in various industrial fields by taking advantage of its characteristics, and research is being conducted for its use. An example of its application in the textile field is to increase the added value of the final product by blending and weaving water-soluble vinylon with various fibers and removing the water-soluble vinylon at an appropriate processing stage before making the final product. There is a usage. In these fields, if crimping could be applied to water-soluble vinylon easily and inexpensively on an industrial scale, it would be of great significance, as it would greatly improve the value of the final product and expand the scope of its use.

Conventional methods for producing crimped vinylon include, for example, increasing the internal strain by low-temperature stretching during spinning, or developing crimping by acetalization treatment, or
No. 44-2071, No. 44-2507, No. 44
There have been proposed methods such as No. 2508, which utilize the difference in shrinkage between two components in the yarn to produce crimp, wooly processing, knit Denisoto method, and the like.

[Problem that the invention seeks to solve]

However, all of these methods require complicated manufacturing facilities and equipment, resulting in high costs, and are therefore industrially disadvantageous. It is only applied to vinylon, which has high hot water resistance.

Therefore, the present inventors have previously proposed an industrially easy method for producing water-soluble crimped vinylon in Japanese Patent Application Nos. 61-45180 and 61-45181, etc., but improvements still need to be made in terms of continuous operability, etc. There was room for.

In view of the current situation, the present invention was completed as a result of intensive research into a method for industrially producing water-bathable crimped vinylon that is inexpensive, easy, and has high performance crimping.

[Means for solving problems]

That is, in the present invention, when producing water-soluble crimped vinylon by the dry spinning method, the process sequence of drawing → heat treatment, which is a common process commonly used in ordinary spinning technology, is often used, and specific steps are taken. Within a limited range, by first performing heat treatment and then subjecting it to a drawing process, latent crimp is achieved, and then this latent crimp yarn is subjected to crimp development under specific conditions. This is a major feature. By carrying out this method, it is possible to efficiently impart high-performance crimp to various water-soluble vinylons having different solubility in water, industrially at extremely low cost and easily.

That is, the gist of the present invention is that when producing water-soluble crimped vinylon by dry spinning using polyvinyl alcohol as a raw material, heat treatment is performed at a temperature (Tj) that satisfies the following conditions before stretching. Later, by performing a drawing process at a temperature (T2) that satisfies the conditions, a latent crimped yarn is obtained, and then the latent crimped yarn i R-H70-100
% of water vapor atmosphere or water or a dry heat atmosphere of 120 to 230°C to develop water-soluble crimped vinylon, the temperature conditions are T1) T2 + 60C. ℃) and 2 3 0>T, ) 120 (1:I L 50>T2>20i℃+.

Next, the present invention will be explained in more detail.

As a raw material for water-soluble crimped vinylon, known polyvinyl alcohol (hereinafter abbreviated as PVA) can be used, but those having a degree of saponification of 88 molti or more and a degree of polymerization of about 800 to 1,700 are preferred. It may also be a modified PVA, such as one copolymerized with Eva, maleic acid, impropenyl acetate, etc., and saponified to have a crystal-inhibiting group with a degree of modification of about 2 to 15 mol.

The stock solution may be prepared according to a known method, and the raw material is dissolved in a heating bath to a concentration of 28. The viscosity may be adjusted to about 100 to 700 poise. Mixing a small amount of additives (antifoaming agent, stringiness improver, etc.) into the stock solution is not a problem.

Next, dry spinning conditions, which are one of the features of the present invention, will be described.

PVA stock solution is mixed with a known Gya Ponzo and nozzle.
After being extruded into a dry spinning tube, it is usually subjected to a stretching process using a stretching roll, and then a heat treatment operation is performed using a heat treatment roll, but in this method, the heat treatment humidity is usually higher than the stretching temperature. In terms of fiber structure, stabilization or
It has been found that this tendency tends to be homogenized, which is disadvantageous in terms of imparting latent crimpability, which is the objective of the present invention.

In order to achieve the purpose of the present invention, firstly, in an undrawn state, the fiber structure is temporarily stabilized by applying a heat treatment effect during the process of being turned into yarn, and then the temperature at the time of heat treatment is lowered. It has been shown that latent crimp performance can be effectively imparted by physically and mechanically disturbing the fiber structure within a range that maintains the physical properties required for product yarn by applying a stretching effect at low temperatures. I found it.

At this time, the heat treatment temperature (TIJ) and the stretching temperature (T2) are
It is essential to satisfy the following conditions.

TI > T2 + 60 (℃l and 230 > TI >
120F℃ 1 1 50 >T2>20 I℃+ In other words, T1 needs to be higher than T2 by 60℃ or more, and if (T1-T2) is within 60℃, good latent curling ability cannot be imparted. becomes difficult or impossible.

When t'r1-'r2+ is preferably 70°C or higher, more preferably 80°C or higher, a water-soluble vinylon having excellent latent crimp ability can be obtained.

It is important that T1 is in the range of 2.30>T1>120, preferably 220>TI>130.
It is MCJ. T1 is one of the characteristics required for the type of PVA used, the spinning speed, and the product yarn. It is determined as appropriate in relation to the melting temperature during immersion in water and treatment, but at temperatures above 230°C, problems such as filamentous coloration and fusion will occur, and below 120°C, the heat treatment effect will be reduced. This is insufficient to provide temporary stabilization of the fiber structure.

On the other hand, it is important that T2 is in the range of 150>T2>20(℃M, preferably 140>T2>30f
℃l.

By physically and mechanically disturbing the temporarily stable intrafiber crystal structure formed in the heat treatment process within the range that maintains the fiber performance required as a product yarn, potential crimp ability is imparted. 150℃ or higher or 20℃
In the following, this potential curling ability imparting effect becomes poor, or
It ends up completely disappearing. Furthermore, there may be cases where the required fiber performance cannot be obtained.

In the stretching process, it is important to specify the stretching ratio, which is determined by T1. T2. In addition, it is appropriately selected in the range of 2 to 8 times depending on the correlation with the fiber physical properties such as strength and elongation required for the product yarn.

In order to disturb the temporary stability of the fiber structure imparted in the heat treatment process by the stretching effect to the extent that the physical properties of the fiber are maintained, it is necessary to prevent the temperature effect during the heat treatment from spreading to the stretching region. It is effective, and for this purpose, in an industrial continuous process, installing a jig that prevents the transfer of heat in the yarn at the boundary between the heat treatment section and the drawing section will greatly contribute to the accomplishment of the present invention. .

For this purpose, rollers, pins, guides, etc. are preferably used, and depending on the fineness of the spun yarn, speed, and required crimp performance (number of crimps, degree of peak and valley height, etc.) , shape, size, material, angle, etc. are selected as appropriate.

In the manner described above, a water-soluble vinylon yarn having excellent latent crimp performance can be obtained.

Even if a water-soluble vinylon yarn with high performance latent crimp properties is obtained in this way, if the subsequent crimp development treatment is not appropriate, the desired high performance water-soluble crimp vinylon will not be produced. Either it cannot be obtained at all, or its crimp performance is poor.

Although the mechanism by which crimping occurs is not clear, by placing the yarn with the latent crimping property in a specific, restricted atmosphere, crimping occurs during the relaxation process of the yarn. In the crimp development treatment, if contraction is restricted, it becomes difficult to develop crimp, so the treatment under tension is disadvantageous, and is usually carried out at a tension of 2η/d or less.

Both wet heat (steam) method and dry heat method can be used for crimping, but depending on the type of raw material PVA (degree of saponification, presence or absence of crystal inhibiting groups, degree of modification, etc., spinning conditions, etc.) The optimum processing temperature varies.

In the curling development treatment by the wet heat method, humidity control is important, and the treatment is carried out using a closed container in a high humidity atmosphere with RbH of 70 to 100%, preferably R' of 80 to 100%, or by immersion in water. be exposed. For R-H70 or less,
The degree of crimping is insufficient, or crimping does not occur at all. In the case of immersion in water, normal tap water, ion exchange water, etc. can be used without being affected by the bath ratio. For latent crimp vinylon, which has a low dissolution temperature in water, crimp development treatment by dipping in water is not suitable.

To give an example of the temperature and time during crimp development treatment in the moist heat method, for yarns with a degree of saponification of 95 molts or more, yarns with a degree of modification of about 2 to 8 molts, etc., the temperature is preferably 50-95°C; Modification degree 12 modified with threads of about 88 molti, maleic acid, impropenyl acetate, etc.
A temperature of 20 to 50°C is appropriate for yarns of about 15 to 15 molar. The processing time at this time is 1 to 60 minutes, and is appropriately selected in relation to humidity, processing amount, etc.

The shrinkage development treatment by dry heat method is carried out in dry heat at 120 to 230°C, preferably 130 to 220°C, for a short time of 5 minutes or less, and both Nototsuchi method and continuous method are possible. It is. At temperatures above 230°C, the curling and shrinkage of the yarn is good, but problems such as hardening of the texture, coloration, and fusion occur.
Below this, the degree of curling will be insufficient.

In either the wet heat method or the dry heat method, if the humidity or temperature is outside the appropriate range, excellent crimping cannot be achieved, causing noises such as tapping, thread adhesion, fusion, and abnormal shrinkage.

As detailed above, according to the present invention, high-performance water-soluble crimped vinylon can be produced industrially at low cost and easily, and when used in combination with other fibers, products with high added value can be produced. It becomes possible to do so.

The present invention will be specifically explained below by giving Examples and Comparative Examples.

Example 1 Average degree of polymerization 1200. PVA with saponification degree of 99.5 molar
A 33% by weight aqueous solution was prepared using the following methods, and a yarn was extruded from a spinneret using a dry spinning method.

Subsequently, the heat treatment temperature was set to 200°C, and the drawing temperature was set to 100°C. A guide was installed between the heat treatment roller and the drawing roller at an angle of 45 degrees to the yarn traveling direction, and the yarn was wound around the guide at a speed of 500 m/min. It was run and subjected to heat treatment and stretching treatment. Thus, the stretching ratio is 4 times, t 20d/30f
A latent crimped yarn was obtained.

Next, this latent crimped yarn was immersed in tap water at 20°C for 1 minute, and then dehydrated to a water content of 80% in a centrifugal dehydrator.
It was dried in a hot air dryer at 50°C to produce a water-soluble crimped vinylon.

Comparative Example 1 A water-soluble crimped vinylon was entirely produced under the same conditions as in Example 1, except that the heat treatment temperature was 200°C and the stretching temperature was 160°C.

Example 2 The latent crimped yarn obtained in Example 1 was converged and cut into 75 squares, then treated with R-H 95% Steam ZEX at a temperature of 90°C for 5 minutes without tension, and air-dried. Then, water-soluble crimped vinylon was produced.

Comparative Example 2 After converging the latent crimped yarn obtained in Example 1 and cutting it into 75 cm, it was treated with Steam ZEX of 50% R-H and a temperature of 90°C for 5 minutes without tension, and then air-dried. A whole water-soluble crimped vinylon was prepared.

Example 3 Modified PVA (average degree of polymerization 1
100, modification degree 12.5 mol%) to make a 35% by weight aqueous solution, which was extruded from a spinneret by a dry spinning method to obtain yarn.

Subsequently, the heat treatment temperature was set to 130°C, and the drawing temperature was set to 50°C. A roller was placed between the heat treatment roller and the drawing roller at an angle of 30 degrees to the yarn traveling direction, and the yarn was wound around the roller at a speed of 400 m/min. Please be sure to run the film for heat treatment and stretching. Thus, the stretching ratio is 5.5 times, 120 d/
A 30f latent crimped yarn is considered.

Next, this latent crimped yarn was treated in a hot air dryer at 210° C. for 5 seconds under no tension to produce water-soluble crimped vinylon.

Comparative Example 3 A water-soluble crimped vinylon was produced under exactly the same conditions as in Example 3, except that the heat treatment temperature was 130°C and the stretching temperature was 110°C.

The property evaluation results for the samples obtained from the above Examples and Comparative Examples are shown in the following table.

(Table) Properties of water-soluble crimped vinylon *1. The number of curls is the average value of 10 measurements, *2. The height is the measured value of the peak and valley heights of the crimp, the average value of 10 measurements, *3. The shrinkage rate is based on the curling process.

As shown in the table above, the water-soluble crimped vinylon obtained in the Examples had excellent crimping performance, especially the height of the crimp peaks and troughs. The material obtained in Example 2 had very good blendability with worsted yarn or woolen yarn, and it was confirmed that a processed yarn with high added value could be obtained.

〔Effect of the invention〕

As is clear from the above results, according to the method of the present invention, crimpability can be easily imparted to various types of water-soluble vinylon. A water-soluble crimped vinylon excellent in terms of peak and valley height can be easily and efficiently produced by continuous operation.

In addition, the obtained crimped vinylon has good blendability with worsted yarn or woolen yarn, making it possible to use it in various ways and expand the range of applications in the textile industry, and its effects are extremely large.

Claims (1)

[Claims] By dry spinning method using polyvinyl alcohol as a raw material,
When producing water-soluble crimped vinylon, before stretching, heat treatment is performed at a temperature (T_1) that satisfies the following conditions, and then by stretching treatment at a temperature (T_2) that satisfies the conditions. After obtaining the latent crimped yarn, the latent crimped yarn is R
・H70-100% steam atmosphere or water or 1
A method for producing water-soluble crimped vinylon, which comprises treating it in a dry heat atmosphere at 20 to 230°C to develop crimping. T_1>T_2+60(°C) and 230>T_1>120(°C) 150>T_2>20(°C) However, T_1... Heat treatment temperature T_2... Stretching temperature