JPH0465523A - Production of acrylic synthetic fiber with deep wrinkle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of fFII] The present invention relates to a novel method for producing Usua, an acrylic synthetic wax having Table 7 KgllA@.

[Conventional technology]

Conventionally, as a method for giving acrylic fibers a deep plate, for example, wet spinning of a spinning stock solution with a low polymer concentration has been carried out.

However, the ψ fibers obtained using this method not only have deep wrinkles on the surface layer, but also have many D voids inside, so although the fibers have excellent water absorption performance and excellent ζ, the strength of the fibers is weak. Since it becomes brittle, it causes various problems in post-processing such as spinning and twisting, which impairs the quality of the final product.

In addition to using a spinning dope with a low polymer concentration, low-temperature stretching or excessively high-magnification stretching in the stretching process is recommended.
Although some attempts have been made to create wrinkles, it is difficult to obtain sufficiently deep wrinkles and process troubles such as yarn breakage due to stretching are likely to occur.

[Problem to be solved by the invention]

The present invention uses acrylic synthetic fibers that have deep wrinkles in the axial direction of the twill fibers in the surface layer, have a cool and appropriate texture, good water absorption, and maintain sufficient strength during product processing and use. It provides a manufacturing method that enables production;

[Means to solve the problem]

The gist of the present invention is to apply a spinning serum containing an acrylonitrile copolymer and a solvent to the core, and a spinning dope containing an acrylonitrile copolymer and a solvent to the sheath in a wet or dry-wet composite spinning process. The table is characterized in that the polymer concentration ratio in the sheath spinning dope satisfies the following formula: %.

The printing process of the present invention will be explained in detail.

The acrylonitrile copolymer targeted by the present invention may be any acrylonitrile copolymer known for use in acrylic fibers, and examples of copolymerizable monomers include esters of acrylic acid and methacrylic acid, and acetic acid. vinyl,
Examples include styrene, acrylic dispersion, vinyl chloride, vinylidene chloride, etc. Also, sodium vinylbenzenesulfonate, sodium methallylsulfonate, for improving dyeability.
It is also possible to further copolymerize sodium p-styrenesulfonate, vinylpyridine, and the like. This acrylonide + 1 compound can be produced by any conventional method such as suspension polymerization, solution R1 polymerization, emulsion polymerization, etc. It makes no difference whether the aquanoronitrile copolymer of the core part and the l14 part are the same 〇m@ or different types.

When the above acrylonitrile copolymer is dissolved in @g& to prepare a spinning stock solution, the solvent used is not limited to the washing percentage as long as it can dissolve the above acrylonitrile copolymer, but for example, dimethyl sulfoxide is used. , dimethylformamide, dimethylacetamide, ethylene carbonate, acetone, and other organic solvents; and nitric acid, rhodan salt aqueous solutions, zinc monide aqueous solutions, and other inorganic solvents. The solvents used in the core and sheath may be different, but
In consideration of solvent recovery in a subsequent step, it is preferable to use the same one.

It is important that the ratio of the polymer concentration in the spinning dope in the core and moving parts satisfies equation (1); if the ratio is Q, 8 or more, too many voids will appear in the sheath during coagulation. As a result, almost no deep wrinkles similar to those of the fibrous axis are formed on the final surface of the fibers.

``In order to maintain the strength of the final fiber at a higher level.''
Since it is important for 1C to eliminate voids in the inner layer and make it as dense as possible, the polymer concentration of the '0 yarn stock solution in the core should be as low as possible: preferably A0 polymer concentration. The range cannot be determined generally depending on the type of polymer solvent, but the viscosity of the core spinning dope is 500°C at 50°C.
It is preferable that the number of voids be about 1,000 to 1,000, in terms of densification of the inner fiber layer and stability of the spinning process.

The nozzle used in the present invention may have a capillary structure with a double tube structure of a core and a sheath, and the capillary diameter and capillary length are appropriately selected depending on the viscosity and amount of the spinning stock solution discharged from the nozzle.

Spinning solution discharged from the core and v3 discharged from the sheath
If the ratio of the yarn stock solution is 1:1 from the core, it will cause wrinkles on the surface layer and become slanted, and if it is too much, it will cause wrinkles on the surface layer, and the ratio from the core will be 1145η. Too ′ν
Since the strength is 4 kg, the polymerizable weight of the core and sheath is approximately 1 kg/core 411 to 0, which is suitable.

Is the spinning dope discharged through the capillary directly coagulated in a coagulating solution? -) Yuru wet spinning method
After passing through a non-coagulating gas, the yarn is formed by a wet-dry yarn protection method in which the a-side is treated in a coagulating liquid.

As the coagulating liquid, it is preferable to use an aqueous solution containing the above-mentioned spinning solvent. In the case of wet spinning using an organic solvent, the concentration of the organic solvent is 30 to 60 ik4, and in the case of dry-wet spinning, it is 50 to 8.
A range of 0 weight t4 is preferable in terms of solving the problems of the present invention, since the core stock solution tends to have fewer voids and the sheath part tends to have more voids. If the concentration is too high, adhesion of the fibers will occur, and if the concentration is too low, voids will occur in the core as well, leading to a decrease in fiber strength.

The yarn that has left the coagulation bath can then be washed, stretched, dried, and heat treated in a conventional manner.

After drying, l! In order to further improve the strength of the fibers and increase the wrinkles on the surface of the fibers, secondary stretching may be carried out if necessary.

Example 1 An acrylonitrile co-monomer consisting of acrylonitrile 93114 and vinyl acetate 7X14 was dissolved in dimethylacetamide (50%), the same acrylonitrile co-monomer as above was dissolved in dimethylacetamide, and the polymer concentration was changed to form a core and a sheath. A spinning yarn 'JXf&' was prepared.

Each of these spinning stock solutions was kept warm at 50°C, and after devesicles were removed, the weight of the copolymer was increased by using a spinneret consisting of a 50-hole concentric capillary nozzle with a core of 112 mm and a sheath of IIL 3 mm. Composite wet spinning was carried out so that part cL5 was formed using dimethylacetamide 50% width and water 504% at a temperature of 40°C.
The fibers were introduced into a coagulating solution to form a thread, and then washed, stretched 4 times in boiling water, dried, and heat treated in this order, and then wound up.

All obtained wI&males were regulated to 150 denier, 150 filament Vc1!1 degree.

In Table 1, Bian 2. A3 has more deep wrinkles than Comparative Example M1, and has better water absorption performance and sluggishness, and also maintains the strength of the yarn and shavings, which proves the effect of the present invention. .

Claims (1)

[Claims] When carrying out wet or dry-wet composite spinning of a spinning dope consisting of an acrylonitrile copolymer and a solvent from a core and a spinning dope consisting of an acrylonitrile copolymer and a solvent from a sheath,
The polymer concentration ratio in the core and sheath spinning dope satisfies the following formula: % polymer concentration in the sheath spinning dope / % polymer concentration in the core spinning dope <0.8 (1) A method for producing an acrylic synthetic fiber having deep wrinkles in the surface layer.