JPH0434033A - Acryl open-end spun yarn - Google Patents

Abstract

PURPOSE:To obtain the subject fire-retardant spun yarn having a specified modification degree of the cross-section and a specified twist coefficient and excellent in gloss by using a fire-retardant acryl polymer composed of acrylonitrile, another monomer copolymerizable with acrylonitrile, vinylidene chloride, etc. CONSTITUTION:A fire-retardant acryl polymer composed of (A) 50-85wt.% acrylonitrile and another monomer copolymerizable with acrylonitrile, (B) 15-50wt.% vinylidene chloride and (C) 0.4-3wt.% olefin-based hydrophilic monomer having a sulfonic acid group is dissolved preferably in 63-70wt.% nitric acid, e.g. in an amount of 15-200pts.wt. based on 100pts.wt. nitric acid. The resultant spinning solution is spun into a coagulation bath preferably having >=48wt.% nitric acid concentration using a nozzle having >=5 spinning draft ratio, thus giving the objective spun yarn having 1.1-1.8 modification degree of the cross-section and 50-90 twist coefficient.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an acrylic open-end spun yarn, and more particularly to a flame-retardant acrylic open-end spun yarn with excellent gloss.

[Conventional technology]

Traditionally, flame-retardant acrylic fibers have been used in the interior bedding and clothing fields, such as curtains and carpets, due to their flame-retardant properties, but as interiors have become more sophisticated, there has been an extremely high demand for gloss. expensive.

As a technique for glossing a spun yarn after spinning, there is a method of applying hot stretching as shown in, for example, Japanese Patent Publication No. 55-31218 and Japanese Patent Application Laid-open No. 63-190035.

However, the spun yarn obtained by these methods has a problem that the residual shrinkage of the yarn due to hot drawing is high and significant weave shrinkage occurs during the weaving stage.To solve this problem, however, thermal relaxation is applied after hot drawing. etc., but the disadvantage is that the required gloss is lost.

[Problem to be solved by the invention]

An object of the present invention is to provide a flame-retardant acrylic open-end spun yarn with excellent gloss.

[Means to solve the problem]

In response to such demands, the present inventors have developed a spun yarn with excellent gloss by using specific acrylic fibers and adopting a specific twist coefficient as a result of intensive studies.

That is, the present invention provides an open-end spun yarn of acrylic fibers in which the acrylic fibers contain 50 to 85% by weight of acrylonitrile and other monomers copolymerizable with acrylonitrile, 15 to 50% by weight of vinylidene chloride, 0. .4～
It is composed of a flame-retardant acrylic polymer consisting of a hydrophilic olefin monomer having 3% by weight of sulfonic acid groups,
The acrylic open-end spun yarn is characterized in that the degree of irregularity is 1.1 to 1.8, and the twist coefficient of the spun yarn is 50 to 90.

The present invention will be explained in detail below.

The specific acrylic fiber used in the present invention and its manufacturing method are detailed in JP-A-61-266611. That is, the flame-retardant acrylic polymer used in the present invention has 5
0 to 85% by weight of acrylonitrile and other monomers copolymerizable with acrylonitrile, 15 to 50% by weight of vinylidene chloride, and 0.4 to 3% by weight of a hydrophilic olefinic monomer having a sulfonic acid group. It is obtained by copolymerizing by a conventional method.

The polymerization method for these copolymers may be any commonly known polymerization method for vinyl monomers. For example, aqueous suspension polymerization using a redox catalyst, solution polymerization, emulsion polymerization, etc. are generally used.

Other monomers copolymerizable with acrylonitrile used in the present invention include acrylic acid and its alkyl esters, methacrylic acid and its alkyl esters, acrylamide, methacrylamide, maleimide, β-aminoethyl methacrylate, acrylamide, methacrylamide. , vinyl acetate, etc., but are not limited to these.

However, vinylidene chloride and hydrophilic olefin monomers having a sulfonic acid group are excluded from the other monomers.

Examples of the hydrophilic olefin monomer having a sulfonic acid group include sulfonic acids such as sulfonic acids such as methallyl sulfonic acid, styrene sulfonic acid, and allyl sulfonic acid, and their salts (e.g., sodium, potassium, and ammonium salts).
can be mentioned.

The polymer thus obtained is dissolved in nitric acid, a zinc chloride aqueous solution, a Rodan salt aqueous solution, dimethylformamide, etc. to prepare a spinning stock solution. Particularly preferred in the present invention are nitric acid water and dimethylformamide.

When using nitric acid as a solvent, for 100 parts of a nitric acid solution with a nitric acid concentration of 60 to 80% by weight, preferably 63 to 70% by weight,
A spinning stock solution is obtained by dissolving the polymer in a proportion of 10 to 40 parts, preferably 15 to 20 parts, and maintaining the temperature of the stock solution during dissolution at 20° C. or lower in order to suppress the oxidation reaction caused by nitric acid. This spinning dope is then spun into a coagulation bath having a concentration higher than the critical concentration.

The critical concentration in wet spinning using nitric acid as a solvent varies depending on the concentration of the solvent used, the concentration of the polymer, the concentration of the coagulation bath, etc., but is generally around 39% by weight.

Similarly, when dimethylformamide is used as a solvent, the critical concentration is around 53% by weight, and when a zinc chloride aqueous solution is used as a solvent, the critical concentration is around 40% by weight.

Spinning using nitric acid as a solvent is carried out in a coagulation bath in which the nitric acid concentration is adjusted to 40% by weight or more, preferably 48% by weight or more, using a nozzle that can set a spinning draft rate of more than 5.

Here, the spinning draft rate is expressed by the following formula.

Spinning draft ratio = (winding roller speed) / (linear speed of spinning dope discharged from the nozzle hole) If the coagulation bath has less than the critical concentration, the spinning draft ratio will not reach 5 and the resulting fiber will have a deep color. lacking in sex. If the coagulation bath concentration exceeds the critical concentration plus 9% by weight, adhesion and sticking between fibers is likely to occur.

If the spinning draft ratio is less than 5, the fibers will sag in the coagulation bath, and the fibers will wrap around the rotating parts, reducing spinning operability, and the resulting fibers will lack depth and poor color development. becomes.

When the spinning draft rate is set to more than 5, the fibers are stretched in a straight line in the coagulation bath, and the higher the spinning draft rate, the richer the color development of the resulting fibers. The above-mentioned critical concentration means the concentration of the solvent in the coagulation bath at which the maximum spinning speed becomes the minimum or no spinning is possible, and where the concentration on either side of the maximum spinning speed has a spinnable region.

When spinning in a coagulation bath with a concentration higher than the critical concentration, the coagulated fibers meander in the coagulation bath, and the resulting fibers become cloudy and completely lose their transparency; therefore, in conventional spinning, Coagulation was performed at a solvent concentration lower than the critical concentration.

The flame-retardant acrylic fiber obtained by washing the fiber thus obtained with water, completely removing the solvent, stretching, drying, and heat treatment has excellent abrasion resistance and deep color development.

In the present invention, the degree of irregularity of the acrylic fiber is 1.
It needs to be 1 to 1.8, preferably 1.1 to 1.4. Outside this range, the gloss is poor. The degree of atypicality (V
) is defined by:

The diameter of the circumscribed circle of the fiber cross section (500 times enlarged photo) (
r) divided by denier (d) (r/d = v
The value (r
O/d=vo), expressed as vl/vo=V.

A method for forming open-end spun yarn from the specific acrylic fibers described above is to spin fibers having a length of 38 to 511 Im using a normal open-end spinning means.

In the present invention, the twist coefficient of this oven-end spun yarn is 50 to
It needs to be 90, preferably 60-80. If it is less than 50, it is difficult to spin, and if it exceeds 90, excellent gloss cannot be obtained.

The woven fabric using the oven-end spun yarn that satisfies the above conditions had high gloss and was visually observed to have a glossy luster. Generally speaking, lowering the twist coefficient reduces yarn strength and makes spinning difficult, but the acrylic fiber of the present invention has a dense and smooth fiber surface, and when these fibers are assembled, the degree of irregularity is low. A flat type with a size of 1.1 to 1.8 has the densest arrangement of single fibers, improves conjugation, and is strong enough to withstand spinning (
(double-thread rice vetch) more than 10 km was obtained.

〔Example〕

The present invention will be explained in more detail with reference to Examples below.

In the present invention, gloss is measured by the following method.

The luster is determined by dyeing the spun yarn, making it into a plain weave at a density of 73 threads/inch, projecting and receiving light at a 45 degree angle using a modified glossy needle (Nippon Heavy Industries), and measuring the intensity of the reflected light (μ匈). expressed.

Strength was determined according to JIS L1071, and rice vetch (RK+) = measurement count x measurement strength (g)/
Expressed in 1000.

Examples 1 to 5, Comparative Examples 1 to 2 A combination of ammonium persulfate and acidic sodium sulfite was used as a polymerization catalyst, and the pH was adjusted to 2.5 with sulfuric acid.
In water at 5°C, acrylonitrile (hereinafter referred to as AN), methyl acrylate (hereinafter referred to as MA), vinylidene chloride (hereinafter referred to as V),
C), Sodium methacryl sulfonate (hereinafter referred to as MS) is AN
/MA/VC/MS=50.5/ 4 /4510.5
Polymerization was carried out for 5 hours at a ratio of 16g of the obtained polymer was dissolved in 100g of 80% by weight nitric acid water at 0°C to obtain a spinning stock solution.

then 42% by weight at 0°C with a critical concentration of 41% by weight.
The spinneret is elliptical and the ratio of the major axis to the minor axis is 1 in the coagulation bath of nitric acid water.
．． 4. Discharge using a nozzle with a hole area of 0.01 d and 100 holes, take it out from the coagulation bath at a speed of 5 m/min, and then add nitric acid at a concentration of 42% by weight and at a bath temperature of 65°C.
The film was stretched 8 times in a stretching bath. The fibers that have been stretched are washed with water, thoroughly dried in hot air at 130"C, and then heated to 115"C.
A single fiber denier of 2d was subjected to thermal relaxation treatment in steam of C.
Acrylic fibers with a degree of irregularity of 1.4 were obtained. The acrylic fiber was made to have a fiber length of 38 m, and a 52 m count twin yarn was obtained by conventional open-end spinning means. At this time, the twist of the single fiber was varied by twist coefficient from α=40 to 100, and the twist of the double yarn was 0.7 times the number of twists of each single yarn. Table 1 shows a comparison of the gloss levels of these twin yarns, which were dyed with chizuru dye and then woven into regular plain weave fabrics with a warp and width density of 73 threads/inch.

Example 6.7, Comparative Example 3.4 The same acrylic polymer as in Examples 1 to 5 and Comparative Examples 1 to 2 was added to a coagulation bath under the same spinning conditions, with an elliptical spinneret and a major axis and a minor axis. The ratio is 1.0.1.1.1.4.1.8.2.0, the pore area is 0.01-, and the fiber is discharged using a nozzle with 100 holes. A fiber with a single fiber denier of 2 denier and a denier of 1.0 to 2.0 was obtained.

These acrylic fibers were subjected to spinning, dyeing, and plain weaving in the same manner as in Examples 1 to 5, and the glossiness was compared in Table 2.

In addition, the number of single yarn twists in the spinning of Example 6.7 and Comparative Example 3.4 is α
=80 The number of double yarn twists was 0.6 times the number of single yarn twists.

As can be seen from Table 1, the example has a high gloss level of 40μ
- Those exceeding - are visually recognized to have a glossy luster,
The glossiness is particularly high when the twist coefficient is between α=50 and 90.

Furthermore, as can be seen from Table 2, the glossiness changed depending on the degree of irregularity of the fibers, and it was recognized that the degree of irregularity V=1.1 to 1.8 had a high glossiness.

(The following is a margin) Table Table Next, a comparison between the above-mentioned example and a conventional fiber using an acrylic polymer is shown below.

Comparative Examples 5 to 11 Using a conventional acrylic polymer, a spinning stock solution was prepared at a ratio of 15 g to 100 g of 67% nitric acid water, and then 35% by weight,
The material was discharged into a coagulation bath of nitric acid water at 0°C using a nozzle with an elliptical spinneret, a ratio of major axis to minor axis of 1.4, and a hole area of 0.01-1 and 100 holes at a rate of 5 m/sin. The film was taken out from the coagulation bath at a speed of 100°C, washed with water, and then stretched 8 times with hot water at 100°C.

Thereafter, the same treatments as in Examples 1 to 5 and Comparative Examples 1 to 2 were performed to provide acrylic fibers. Using the acrylic fibers, the glossiness was determined in the same manner as in Examples 1 to 7, and compared with the examples as Comparative Examples 5 to 11. The relationship with the twist coefficient is shown in Table 3. The relationships are shown in Table 4. When a conventional acrylic polymer was used, it was difficult to obtain a desired degree of irregularity, and the degree of fiber irregularity was 1.4.1.8 or not.

As can be seen from Tables 3 and 4, fibers made using conventional acrylic polymers have a twist coefficient of 60 to 90 and an irregular shape of 1.4 to 1.
．． 3 −r, 4 °−υ, poor gloss.

(Hereinafter in the margin): Effects of the Invention The oven-end spun yarn of the present invention is a flame-retardant ACJ spun yarn having an unprecedentedly excellent luster.

Claims (1)

[Claims] In the open-end spun yarn of acrylic fibers, the acrylic fibers contain 50 to 85% by weight of acrylonitrile and other monomers copolymerizable with acrylonitrile, and 15 to 5% by weight of acrylonitrile and other monomers copolymerizable with acrylonitrile.
It is composed of a flame-retardant acrylic polymer consisting of 0% by weight of vinylidene chloride and 0.4 to 3% by weight of a hydrophilic olefinic monomer having a sulfonic acid group, and has a degree of irregularity of 1.
1 to 1.8, and the twist coefficient of the spun yarn is 50 to 90.