JPH0874119A - Highly shrinkable acrylic fiber and method for producing the same - Google Patents

Abstract

(57) [Summary] [Object] To provide an acrylic fiber that is sensitive to dry heat and has excellent fast shrinkability and high shrinkability, and further to obtain such an acrylic fiber industrially easily and stably. [Structure] Acrylonitrile-based polymer consisting of 90 to 95% by weight of acrylonitrile, 0 to 0.5% by weight of sulfonic acid group-containing vinyl monomer and 10 to 4.5% by weight of other vinyl monomer, and dried under no load. The shrinkage percentage after 10 minutes at 130 ° C. in a hot atmosphere is 30% or more, and the maximum value of the heat shrinkage stress measured in a heated atmosphere at 10 ° C./min is 90 to
It is between 130 ℃ and the maximum value of heat shrinkage stress is 100.
When a highly shrinkable acrylic fiber having an amount of mg / d or more is produced by a wet spinning method, a spinning draw of 2 to 6 times, dry densification, shrinkage relaxation of 30% or more in pressurized steam, 1.6 to
It is obtained by sequentially performing 2.2 times dry heat drawing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acrylic fiber having high shrinkability and a method for producing the same.

[0002]

2. Description of the Related Art Acrylic fibers have animal hair-like texture and luster, and are used in the knitting field as well as in the bore and high pile fields. Of these, the high pile usually has a double-layered structure of stabbing hair and downing hair, but a highly shrinkable acrylic fiber is suitable for downing hair. In addition, due to the need for the development of a wide variety of products in recent years, a large number of special texture yarns, high bulky yarns, special pile fabrics, etc. have been made by mixing highly shrinkable fibers with regular acrylic fibers. The need for system fibers has increased significantly.

Against this background, many methods for producing highly shrinkable acrylic fibers have been conventionally proposed.
For example, in JP-A-60-110910, a coagulated unstretched fiber obtained by wet spinning is stretched 1.5 to 3 times, washed with water at a temperature of 70 ° C. or higher and relaxed to 70 to 70 ° C.
It is disclosed that secondary stretching is performed with hot water at 90 ° C. However, drawing with hot water yields only fibers having a good boiling water shrinkage but a poor dry heat shrinkage. Japanese Patent Application Laid-Open No. 60-110910 discloses a method in which primary stretching is performed to 3 times or less, drying is performed, and then secondary stretching is performed in hot air at 100 to 140 ° C. to 1.5 to 3 times. Hot air is heated air that is moist and does not have excellent dry heat shrinkability.

Further, in Japanese Patent Application Laid-Open No. 4-119114, 80% by weight or more of acrylonitrile, 0.5 to 5% by weight of a sulfonic acid group-containing monomer, and 5 to 1 of vinyl monomer.
Disclosed is a fast-shrinking fiber composed of 5% by weight of a polymer and having a dry heat shrinkage ratio of 30% or more at 120 ° C. for 1 minute. However, when a large amount of a sulfonic acid group-containing monomer is copolymerized, the elongation decreases, so the passability in the spinning process deteriorates, and further, the coagulability in the coagulation bath in the spinning process decreases, Adhesion of fibers easily occurs in the spinning process. In addition, in this publication, the shrinkage ratio is measured under no load.

Generally, in napped products such as boa, high pile, carpet, etc., it is necessary to mix several kinds of raw cotton to shrink only the hair-producing component therein, but the hair-producing component is more than the resistance of other fibers. If it has no heat shrinkage stress, it cannot be shrunk even if it is heat-treated in the finishing process of the napped product. Therefore, as the shrinkability usually required for high pile hair production, not only high shrinkage but also heat shrinkage stress is required from the standpoint of the quality of the napped product.

[0006]

DISCLOSURE OF THE INVENTION The present invention, in particular, since the heat treatment apparatus in the finishing process of napped products is of a dry heat type, the present invention diligently investigates the heat shrinkability and the heat shrinkage stress against dry heat. It was made as a result of. An object of the present invention is to provide an acrylic fiber which is sensitive to dry heat and has excellent fast shrinkability and high shrinkability. Another object of the present invention is to industrially easily and stably obtain such acrylic fiber having fast shrinkability and high shrinkability.

[0007]

The present invention comprises 90 to 95% by weight of acrylonitrile, 0 to 0.5% by weight of a sulfonic acid group-containing vinyl monomer and 10 to 4% of other vinyl monomers.
Consists of 5% by weight of acrylonitrile-based polymer, and the shrinkage percentage after 30 minutes at 130 ° C. in a dry heat atmosphere under no load is 30% or more, and the heat shrinkage stress measured in a temperature rising atmosphere of 10 ° C./min. Has a maximum value between 90 and 130 ° C,
And a high shrinkage acrylic fiber characterized by having a maximum value of heat shrinkage stress of 100 mg / d or more, and

An acrylic fiber is produced by a wet spinning method from an acrylonitrile polymer consisting of 90 to 95% by weight of acrylonitrile, 0 to 0.5% by weight of a sulfonic acid group-containing vinyl monomer and 10 to 4.5% by weight of another vinyl monomer. In doing so, 2 to 6 times spinning drawing, dry densification,
A method for producing a highly shrinkable acrylic fiber, which comprises sequentially performing relaxation of 30% or more in pressurized steam and 1.6 to 2.2 times dry heat drawing.

The acrylonitrile-based polymer which constitutes the highly shrinkable acrylic fiber of the present invention is acrylonitrile,
It is composed of a sulfonic acid group-containing vinyl monomer and another vinyl monomer, and examples of the sulfonic acid group-containing vinyl monomer include sodium allyl sulfonate, sodium styrene sulfonate, sodium 2-acrylamido-2-methylpropane sulfonate, and the like. However, the present invention is not limited to these. The amount of the sulfonic acid group-containing vinyl monomer as a polymer composition is 0 to 0.5% by weight, and the presence of the sulfonic acid group-containing vinyl monomer gives the fiber good gloss and dyeability.

Examples of other vinyl monomers include acrylic acid, methacrylic acid, or their alkyl esters, vinyl acetate, acrylamide, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, glycidyl methacrylate, glycidyl acrylate and the like. , May be used alone or in combination,
Particularly, vinyl acetate and methyl acrylate are preferable in terms of quality and cost. The amount of vinyl monomer as a polymer composition is 10 to 4.5% by weight. If it is less than 4.5% by weight, it is difficult to impart sufficient dry heat shrinkability to the fiber, and more than 10% by weight. If so, the occurrence of sticking of the fiber and the deterioration of the physical properties of the fiber due to the decrease in the heat resistance are significant.

The highly shrinkable acrylic fiber of the present invention has good fiber physical properties based on the polymer composition of the composition and easily shrinks by dry heat treatment.
It has high shrinkability with a shrinkage ratio of 30% or more after 10 minutes at 130 ° C. in a dry heat atmosphere under no load. Shrinkage rate is 30
If it is less than%, the performance as high shrinkability is insufficient and sufficient product quality cannot be secured.

Further, in the highly shrinkable acrylic fiber of the present invention, the maximum value of the heat shrinkage stress measured in a temperature rising atmosphere of 10 ° C./min is between 90 and 130 ° C. It is necessary that the maximum value is 100 mg / d or more. In the heat treatment in the finishing process of napped products, 90
Although a temperature of ~ 130 ° C is applied to the fiber, the fiber of the present invention has a maximum value of heat shrinkage stress in this temperature range. Further, in order to shrink the hair-providing component only in the napped product by mixing the stinging component and the hair-providing component, the heat shrinkage stress is 1
When the heat shrinkage stress is less than 100 mg / d, the shrinkage property against other existing fibers and tissues is insufficient, resulting in poor quality of the obtained product. .

The highly shrinkable acrylic fiber of the present invention may contain a weather resistance stabilizer, an antibacterial agent, a pigment, an antistatic agent, a conductive agent, an antifouling agent and the like.

The highly shrinkable acrylic fiber of the present invention is produced by the following method. That is, 90 to 95% by weight of acrylonitrile, vinyl monomer containing sulfonic acid group 0
Acrylonitrile-based polymer consisting of 0.5% by weight to 10% to 4.5% by weight of other vinyl monomer is spun by a wet spinning method, drawn 2 to 6 times by spinning, applied with an oil agent, dried and densified, and then pressurized steam is applied. It can be manufactured by relaxing 30% or more in the inside and further stretching by 1.6 to 2.2 times.

The acrylonitrile-based polymer is 90 to 95% by weight of acrylonitrile, 0 to 0.5% by weight of a sulfonic acid group-containing vinyl monomer, and 10 to 10 other vinyl monomers.
4.5 wt% is polymerized by a known method such as aqueous suspension polymerization, aqueous emulsion polymerization or solution polymerization to remove residual monomers, and then dissolved in a solvent or used as it is as a spinning stock solution. The solvent used may be either an organic solvent or an inorganic solvent.

The spinning dope is spun into the coagulation bath from the spinneret. The coagulation bath is preferably an aqueous solution of the same solvent as the solvent in the spinning dope in order to reduce the cost of solvent recovery and simplify the recovery process. The coagulated yarn spun in the coagulation bath is usually drawn 2 to 6 times, preferably 3 to 4 times, through several washing and drawing baths in which the solvent concentration is gradually decreased. If the draw ratio is less than 2 times, the orientation of the molecular chains of the fiber is insufficient and the mechanical strength of the obtained fiber is low, so the passability in the spinning process is reduced and the durability of the obtained product is also reduced. On the other hand, if it exceeds 6 times, problems of operability such as yarn breakage occur.

After the spinning and drawing, the product is washed with water in a water washing tank at 50 ° C. or higher to apply an oily agent, and then dried and densified. Next, in the present invention, it is necessary to shrink and relax 30% or more, preferably 35% or more in pressurized steam, and the relaxation treatment in pressurized steam is performed at a temperature of 110 to 150 ° C, preferably 115 to 135 ° C. In saturated water vapor to relax the fibers. If the temperature is lower than 110 ° C, relaxation of 30% or more cannot be obtained, and if the temperature exceeds 150 ° C, a problem of operability such as sticking occurs.

In the present invention, further, 1.6 to 2.2.
Double dry heat drawing. The dry heat stretching treatment is 100 to 140.
C., preferably 110 to 130.degree. Temperature is 100
If the temperature is lower than ℃, the tension at the time of stretching becomes excessive, and it is possible to draw only at a low stretching ratio to obtain a highly shrinkable fiber. If the temperature exceeds 140 ° C, the tension at the time of stretching is small and the fiber is stretched at a high stretching ratio. Although possible, it is not possible to obtain highly shrinkable fibers by using any draw ratio. The draw ratio is required to be 1.6 times or more to obtain the fiber which is the object of the present invention.
If it exceeds 2.2 times, the physical properties of the fiber such as strength and gloss deteriorate.
Causes thread breakage. The fiber after dry heat drawing is appropriately subjected to a treatment and an operation necessary for a spinning step such as imparting a mechanical crimp by a known method.

[0019]

EXAMPLES The present invention will be specifically described below with reference to examples. In the examples, the reduced viscosity of the polymer was measured with a 0.5% by weight aqueous solution of dimethylformamide at 25 ° C. using a Canon Fenske viscometer (manufactured by Canon Inc.). Parts and% mean parts by weight and% by weight, respectively. The shrinkage ratio was measured under a dry heat atmosphere at 130 ° C. for 10 minutes under no load. Further, the heat shrinkage stress was measured in air at a temperature rising rate of 10 ° C./min.

(Examples 1 to 3 and Comparative Examples 1 and 2) By the aqueous suspension polymerization method, acrylonitrile (AN) / vinyl acetate (AV), AN / having a composition shown in Table 1 and a reduced viscosity of 1.95 were used.
Each binary copolymer of methyl acrylate (MA) was obtained. Then, each polymer was dissolved in dimethylacetamide to prepare a spinning dope having a polymer concentration of 25%. The spinning solution was spun into a coagulation bath of dimethylacetamide 40% / water 60%, 40 ° C. using a nozzle having a pore size of 60 μm and a number of holes of 10,000, and the solution was tripled through a washing and drawing bath of 5 stages in which the solvent concentration was gradually decreased. Spinning and drawing were performed, and an oil agent was applied and dry densification treatment was performed. Then, under the conditions shown in Table 1, after relaxation treatment in pressurized steam and dry heat drawing using a heat roller, mechanical crimping was applied to obtain fibers having a single fiber fineness of 8 denier. The operability is also shown in Table 1. The fiber physical properties and thermal physical properties of the obtained fibers are shown in Table 2.

[0021]

[Table 1]

[0022]

[Table 2]

(Example 4, Comparative Example 3) AN / AN having a composition shown in Table 3 and a reduced viscosity of 2.05, obtained by an aqueous suspension polymerization method.
AV, AN / sodium methallyl sulfonate (MS)
Fibers each having a single fiber fineness of 8 denier were obtained in the same manner as in Example 1 except that the respective ternary copolymers were used. Table 4 shows the fiber properties and thermal properties of the obtained fibers.

[0024]

[Table 3]

[0025]

[Table 4]

[0026]

EFFECTS OF THE INVENTION The highly shrinkable acrylic fiber of the present invention has fast shrinkability and high dry heat shrinkage, and while having high shrinkability, there is no hardening or embrittlement of the fiber and the conventional high shrinkage. It retains excellent physical properties even when compared to natural fibers, and is useful as a material component of napped products such as bores, seals, and high piles, and is capable of exerting its performance in such products. It is extremely meaningful. Further, according to the present invention, such a highly shrinkable acrylic fiber can be easily produced industrially stably and inexpensively with an apparatus for producing an ordinary acrylic fiber.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Hosokawa 20-1 Miyukicho, Otake City, Hiroshima Prefecture Mitsubishi Rayon Co., Ltd. Otake Office

Claims (2)

[Claims] 1. An acrylonitrile-based polymer comprising 90 to 95% by weight of acrylonitrile, 0 to 0.5% by weight of a sulfonic acid group-containing vinyl monomer and 10 to 4.5% by weight of another vinyl monomer, and under no load. Shrinkage after 10 minutes at 130 ° C in dry heat atmosphere is 30% or more, 10 ° C
The maximum value of the heat shrinkage stress measured in a temperature rising atmosphere of 9 / min is 9
It is between 0 and 130 ℃, and the maximum value of heat shrinkage stress is 1
Highly shrinkable acrylic fiber characterized by being at least 00 mg / d. 2. A wet-spinning method of acrylic fibers from an acrylonitrile polymer consisting of 90 to 95% by weight of acrylonitrile, 0 to 0.5% by weight of a sulfonic acid group-containing vinyl monomer and 10 to 4.5% by weight of another vinyl monomer. 2-6 times of spinning drawing, dry densification, relaxation of 30% or more in pressurized steam, 1.6-2.2.
A method for producing a highly-shrinkable acrylic fiber, which comprises sequentially performing double dry heat drawing.