JPS60194110A - Heat-resistant acrylic fiber and its manufacture - Google Patents

Abstract

PURPOSE:To obtain the titled fiber having excellent dyeability and suitable for a conversion effect jersey, etc., by spinning an acrylonitrile polymer composed of acrylonitrile and a comonomer, washing, drawing and drying the fiber, and carrying out the high-temperature dry heat-treatment under a specific condition under tension. CONSTITUTION:An acrylonitrile polymer composed of (A) 100-97wt% acrylonitrile and (B) 0-3wt% comonomer copolymerizable with acrylonitrile (e.g. methyl acryate) is spun by wet or dry-spinning process, washed with water, drawn, dried, and treated at 150-250 deg.C in a dry atmosphere under tension to obtain the objective fiber having an initial modulus of 250-400kg/mm.<2> under dry- heat condition at 130 deg.C or an initial modulus of 100-150kg/mm.<2> in hot water at 100 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an acrylic fiber having an excellent initial modulus at high temperatures, which has not been seen in conventional acrylonitrile fibers, and a method for producing the same.

Conventional technology Conventional acrylic fibers are characterized by their soft texture and vivid color development, and are mainly used in the fields of clothing (mainly 22, 2, 3, jersey), interior, bedding, and miscellaneous goods. I came. However, the drawback of acrylic fibers is that they do not have high strength, high modulus, or heat resistance (high strength and high modulus at high temperatures), so they are used in the clothing field, as well as in the fields of thick fabrics and anti-dyed jersey. In addition, it is extremely difficult to apply it to the industrial materials and civil engineering materials fields, which are the mainstream in non-clothing fields.6. -ta. On the other hand, other composite materials such as ester fibers, nylon fibers, polyvinyl alcohol fibers (Hinilon), polypropylene fibers, and aramid fibers have high strength and high modulus as their fiber physical properties. Therefore, it is being developed in various fields of non-clothing industrial materials.

Furthermore, since ester fibers have heat resistance of sieve modulus at high temperatures, they have applications in the clothing field, such as textiles and anti-dyed jersey.

Summary of the Invention Therefore, in the present invention, as a result of intensive study on the development of an acrylic fiber that improves the heat resistance under high temperatures, which is a drawback of acrylic fibers, and has a high modulus even under high temperatures, 250~ at 130℃
400 to νfxra%100~15 under 100℃ hot water
We have found an acrylic fiber with excellent heat resistance and a high modulus of νi of 0.

That is, an object of the present invention is to provide an acrylic fiber with excellent heat resistance and high modulus at high temperatures, thereby achieving the heat resistance required in the textile field of clothing and the field of anti-dyed jersey. In order to satisfy this need, the objective is to provide acrylic fibers for textiles and anti-dyed jerseys with good color development, and to expand their use in this field. Another objective is to make it possible to expand into non-clothing industrial materials fields and civil engineering materials fields, where it has been difficult to enter or develop applications for acrylic fibers. The fiber of the present invention maintains the characteristics of acrylic fibers, such as being light (low specific gravity) and not melting even at high temperatures, so it can be used as an effective material for clothing. Advantageous applications can be considered in the fields of textiles, anti-dyed jersey, and industrial materials and civil engineering materials.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail. First, the acrylic fiber of the present invention is at least 97% by weight.
The main component is acrylonitrile, and 0 to 3% by weight of Ac! Vinyl monomers copolymerizable with IJ), such as methyl acrylate, methyl methacrylate, acrylamide, methacrylamide, N-methylacrylamide, N-ethylmethacrylamide, maleimide, allyl alcohol, methallyl alcohol, β -Hydroxyethyl methacrylate, 2-chloro-3-hydroxypropyl methacrylate, methallylamine, β-aminoethyl methacrylate, acrylic acid, methacrylic acid, itaconic acid, ethyl methacrylate, α-methylacrylonitrile, α-cyanoacrylonitrile, vinyl acetate, vinyl hydrochloride , vinylidene chloride, and styrene.The vinyl monomer is not limited to the above.

If the main component, acrylonitrile, is less than 97% by weight, the proportion of acrylonitrile constituting the acrylic polymer will decrease, making it difficult to obtain high modulus at high temperatures without deteriorating heat resistance. This makes the manufacturing method very difficult. From this point of view, in order to obtain excellent heat resistance and high modulus at high temperatures, it is essential to contain at least 97% by weight of acrylonitrile, which is the main component. Furthermore, in order to have excellent physical properties such as high modulus and heat resistance at high temperatures, the acrylic polymer is spun using a wet or dry spinning method, and after passing through the usual water washing, stretching, and drying steps, it is then dried at a high temperature. It is essential to perform the setting process under heat stress.

The conditions for this set treatment include a treatment temperature of 150 to 2
If the processing temperature is lower than 150°C, not enough heat will be transferred to the fibers and the fibers may therefore be set, resulting in residual shrinkage.
When heat is applied during processing or use of the raw cotton, the lOR fibers shrink, resulting in a decrease in modulus, and thus cannot have excellent heat resistance. Furthermore, when the treatment temperature becomes higher than 250° C., the raw cotton undergoes severe yellowing, stress relaxation occurs inside the fibers, and the modulus begins to decrease. Yellowing of the raw cotton itself may mean that it can be used in certain fields of civil engineering materials, but as an acrylic fiber that is characterized by color development, it is unsuitable.
It has its drawbacks as well.

From the above, in order to obtain the target acrylic fiber, the treatment temperature under high-temperature dry heat should be in the range of 150 to 250°C, preferably 180 to 220°C. Processing temperature Another important condition is to keep the raw cotton at least at a constant length during heat treatment, and preferably to stretch it at 5%. It is not possible to obtain fibers with physical properties such as heat resistance, corrosion resistance, and high modulus.
If stretching is carried out at a relatively large value, yarn breakage may occur frequently during processing and at the same time, one residual shrinkage may remain.
Due to the application of heat during fiber processing or use), shrinkage may occur and the modulus may decrease. From the above, it is necessary to process the fibers under high temperature dry heat while stretching the fibers to a foot length, preferably up to 5%. The fiber thus obtained has excellent heat resistance and high modulus at high temperatures. Especially dry heat] The initial modulus at 30℃ is at least 250
1 mm, and the initial modulus in hot water at 100° C. is at least 100 klV'mm2, which is 20 to 30 times higher than that seen in conventional acrylic fibers.

Because the initial modulus at high temperature of 130°C is more than 250μm2, when used in the industrial field, the fiber itself will not deteriorate, and even composites using the fiber as a reinforcing material. It also means that the body does not change heat.

However, if an attempt is made to obtain a fiber with an initial modulus greater than 400 kg/wn2, production stability will be lacking. However, with conventional acrylic fibers, dry heat 1
Since the initial modulus at 30°C was much lower than 250 kgkn2 (approximately 8 kg/1an2), the fiber itself would undergo thermal deterioration when exposed to high temperatures, causing problems as a composite material. Ta.

In addition, the initial modulus is 100100k in hot water at 100℃.
If it is F or higher, it is possible to eliminate sagging during anti-dying in the clothing field, and it is possible to obtain cloth with good elasticity. Furthermore, in the field of textiles, it is possible to obtain good products that do not lose their shape or wrinkle easily even when subjected to high temperature and moist heat treatment (for example, steam ironing) during sewing or use. However, if an attempt is made to obtain a fiber with an initial modulus greater than 150 kg/fa2, production stability will be lacking. However, for these uses, conventional acrylic fibers (hot water 100℃
The initial modulus below was approximately 6, making it extremely difficult to develop C2) from the viewpoint of heat resistance.

As mentioned above, the present invention is an acrylonitrile-based fiber that exhibits
It is characterized by having a high modulus at high temperatures, and will greatly contribute to the expansion of applications in the clothing and non-clothing fields, especially in the fields of industrial materials and civil engineering materials.

Embodiments Next, embodiments of the present invention will be described. When measuring the modulus, use the Tensilon-■ model (
(manufactured by Toyo Baldwin) was used. In addition, when measuring under high temperature dry heat, the modulus is measured in a glycerin bath.
For measurements under high temperature and humidity, the modulus was measured in a hot water bath at 100°C.

Further, in the examples, thermal dimensional stability, which is correlated with heat resistance, is expressed by the deformation rate of the fiber (the following formula) in 100° C. hot water and 130° C. dry heat.

S,: initial fiber length.

S2: 100℃ hot water, Arui under 130℃ dry heat, 0.
1 Fiber length after being left under Vd load for 10 minutes.

If the deformation rate is greater than 6%, thermal dimensional stability,
That is, heat resistance is not good.

Example 1 100% by weight of acrylonitrile was processed by an aqueous suspension polymerization method using a redox catalyst containing 2.0% by weight of ammonium persulfate and 0.25% by weight of ammonium bisulfite.
Polymerization is carried out at 50° C. for 8 hours to obtain a polyacrylonitrile polymer. This polymer was dissolved in a 68.0% nitric acid aqueous solution,
Adjust the viscosity of the stock solution to 900 pa (at O°C). This spinning stock solution is extruded through a nozzle with a hole diameter of 0.076wn and a number of holes of 200, and coagulated with a 33% by weight dilute aqueous nitric acid solution. After that, it goes through washing, stretching, and drying steps.

Thereafter, the fibers were subjected to setting treatment for 16 seconds under various dry heat conditions at a constant length with a limited shrinkage rate of o. Depending on the use, the fibers were crimped or cut to a certain length to obtain the final fiber form.

Regardless of the fiber form, the fibers of the present invention have a high modulus and thusour under high temperatures. The modulus values of the fibers are listed in Table 1.

Example 2 98% by weight of acrylonitrile and 2% by weight of methyl acrylate were polymerized at 55°C for 7 hours under the catalyst of azobisisobutyronitrile by an aqueous suspension polymerization method to obtain an acrylonitrile copolymer. Obtained.

25% by weight of this copolymer was dissolved in dimethylformamide 5-layer solution. After dissolving, the spinning dope was made into a pore size of 0.08 m.
+n, extruded through a nozzle with 250 holes, and coagulated under an aqueous dimethylformamide solution containing 55% by weight of dimethylformamide and a temperature of 40°C.

Thereafter, after passing through stretching, water washing, and drying steps, a setting treatment was performed for 15 seconds under various tensions under high temperature dry heat at 220°C. Depending on the use, the fiber may be crimped,
Alternatively, the final fiber form was obtained by cutting to a certain length. In any of the fiber forms, the fibers of the present invention have high modulus at high temperatures. The modulus values of the fibers are listed in Table 2.

Claims (2)

[Claims] 1. Consists of an acrylonitrile polymer consisting of 100 to 97% acrylonitrile, θ to 3% i:% acrylonitrile, and a comonomer that can be copolymerized, and 13
Initial modulus under dry heat at 0℃ is 250-400
- theory, or the initial modulus under 100℃ hot water is 10
A heat-resistant acrylic fiber with a high modulus of 0 to 150-m2. 2. Acrylonitrile polymer consisting of 100 to 97% by weight of acrylonitrile and 0 to 3% by weight of a comonomer copolymerizable with acrylonitrile. Spun by wet or dry spinning method, washed with water, stretched, and dried. , 15
A method for producing heat-resistant acrylic fibers, which comprises processing under tension of high-temperature dry heat at 0 to 250°C.