JP3213152B2 - Method for producing acrylic synthetic fiber containing carbon black excellent in spinnability - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an acrylic synthetic fiber containing carbon black having excellent spinnability.

[0002]

2. Description of the Related Art Acrylonitrile stock solution colored synthetic fibers,
In particular, as a method for producing acrylonitrile-based synthetic fibers containing carbon black, carbon black is dispersed in a relatively low-viscosity solution of an acrylonitrile-based polymer of the same type as the spinning dope, and finely divided by a pulverizer such as a ball mill. 2. Description of the Related Art There is known a method of stirring, mixing into a spinning solution, and spinning. However, this method has a problem that the stability of a low-viscosity solution of an acrylonitrile-based polymer in which carbon black is dispersed is poor, and the solution is colored or gelled with the passage of time. Further, even if such a carbon black dispersion is added to and mixed with the spinning dope, the finely divided carbon black easily causes secondary aggregation in the spinning dope,
As a result, poor passability in a stock solution process such as an increase in filtration pressure and clogging of a spinneret and a problem of yarn breakage in a spinning process occur, so that high-quality acrylic synthetic fibers cannot be obtained at all.

[0003]

As described above, various means for improving spinnability when spinning an acrylonitrile-based polymer containing carbon black have been proposed, but they are excellent in spinnability and stability. A method for producing a stock solution colored acrylic synthetic fiber using carbon black has not yet been obtained.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a method for producing a stock solution-colored acrylic synthetic fiber made of carbon black having excellent spinnability and excellent stability. To be.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to provide an acrylonitrile-based polymer containing carbon black in which a highly condensed naphthalene sulfonic acid salt is previously contained in an organic solvent in an amount of 0.01 to 3% by weight based on carbon black. After dissolution, carbon black is uniformly dispersed, and then added to a spinning solution of an acrylonitrile-based polymer, which is spun, and is achieved by a method for producing an acrylic synthetic fiber containing carbon black having excellent spinnability. You.

Hereinafter, the present invention will be described in detail.

The acrylonitrile polymer used in the present invention contains at least 30% by weight of acrylonitrile, and any polymer having a fiber forming ability can be used. That is, acrylonitrile is 30% by weight or more and other vinyl monomers such as acrylic acid, methacrylic acid, or alkyl esters thereof, vinyl acetate, vinyl chloride, vinylidene chloride, sodium allyl sulfonate, sodium methallyl sulfonate, vinyl sulfone. Acid soda, sodium styrenesulfonate, 2
-Acrylamide-2-methylpropanesulfonate and the like are appropriately combined and copolymerized at a ratio of 70% by weight or less. In particular, a copolymer of a vinyl-based monomer and sulfonic acid group-containing monomer in an amount of 80% by weight or more and 20% by weight or less of acrylonitrile, or 30-80% by weight of acrylonitrile and 20-70% by weight of vinyl chloride and / or vinylidene chloride and a sulfonic acid group A copolymer containing 0 to 10% by weight of the contained monomer is preferable.

The polymer used in the present invention is produced by a known polymerization method such as aqueous suspension polymerization, emulsion polymerization and solution polymerization, and is not particularly limited.

The highly condensed naphthalene sulfonate used in the present invention includes highly condensed sodium naphthalene sulfonate and highly condensed ammonium naphthalene sulfonate. Although this highly condensed naphthalene sulfonate is usually soluble in water, it can be dissolved in an organic solvent, particularly dimethylformamide (D
It does not dissolve in MF). Therefore, an aqueous solution is prepared in advance using a small amount of water, and the aqueous solution is dissolved in an organic solvent before use. Alternatively, an aqueous solution may be used in advance.
The amount added to the organic solvent is 0.01 to 3% by weight, preferably 0.1 to 1% by weight, based on carbon black. If it is less than 0.01% by weight, the effect of improving the dispersibility of the carbon black is not obtained, and if it exceeds 3% by weight, the effect of improving the dispersibility of the carbon black is not obtained, and the fiber quality is rather deteriorated.

The carbon black used in the present invention is not particularly limited, and examples thereof include furnace black, channel black, and acetylene black.
The amount of carbon black in the organic solvent in which the highly condensed naphthalene sulfonate has been previously dissolved is not particularly limited, but is usually preferably in the range of 5 to 25% by weight. If the amount is less than 5% by weight, the carbon black becomes thin, which is not preferable from the viewpoint of productivity.

As a device for adding and mixing an organic solvent containing highly condensed naphthalene sulfonic acid and carbon black to a stock solution for spinning an acrylonitrile polymer, an ordinary mixer is used, but in view of uniform dispersion. A homomixer is preferably used. Further, it is preferable to use an ultrasonic dispersion filter for the purpose of further improving the dispersion.

[0012] The spinning method may be carried out under the same conditions as ordinary acrylic synthetic fibers.
Perform washing, drying and post-treatment.

[0013]

Next, the present invention will be described in detail with reference to examples. In the examples, “parts” indicates “parts by weight” and “%” indicates “% by weight”. Evaluation of the dispersion state was performed in five steps (（: very good, ○: good, Δ: slightly poor, ×: poor, XX: very poor) by visual judgment of 10 professional inspectors.

Examples 1-2, Comparative Examples 1-2 Acrylonitrile (AN) / methyl acrylate (M
A) A solution of an acrylonitrile-based polymer in dimethylformamide (DMF) composed of 91.2 / 8.0 / 0.8 of sodium 2-acrylamido-2-methylpropanesulfonate (SAM) was prepared and used as a spinning solution. . Next, a high-condensed sodium naphthalenesulfonate (trade name: Rome D: manufactured by Sanyo Chemical Co., Ltd.) was dissolved in DMF in a predetermined amount with respect to furnace black (carbon black 40: manufactured by Mitsubishi Kasei Kogyo Co., Ltd.). The weight% was dispersed using a homomixer and an ultrasonic disperser to obtain a dispersion. The dispersibility of carbon black in this dispersion, the dispersibility of carbon black after leaving the dispersion for 2 weeks, and the color spinning dope when the dispersion was added so that the carbon black was 2% by weight based on the spinning dope. Table 1 shows the dispersibility of the carbon black.

Next, the above-mentioned colored spinning stock solution was added at 20 ° C. and 60 ° C. using a nozzle having a nozzle hole diameter of 0.06 mm and 4000H.
After spinning in an aqueous solution of DMF and elongating and washing with water while removing the solvent, a fiber oil agent was applied, and then dried and densified at 150 ° C. using a roller drier. Next, after the mechanical crimp was applied, the crimp was set at 115 ° C. in wet heat to obtain 3d black fibers. Table 1 shows the rise in die pressure at this time.

Comparative Examples 3 to 5 Comparative Examples 2 and 3 were the same as Examples 1 and 2 except that Roxy D was replaced with polyoxyethylene (n = 30) sorbitan monolaurate. Performed similarly.
Table 1 shows the results.

[Table 1]

As is evident from Table 1, the product of the example has better dispersibility and spinnability than the product of the comparative example.

[0018]

As described above in detail, according to the method of the present invention, an acrylic synthetic fiber containing carbon black is industrially advantageously produced since a highly condensed naphthalene sulfonate which is inexpensive and easy to handle is used. sell. Further, even when carbon black is added to the stock solution for spinning, secondary aggregation does not occur, and good and stable production is possible in both spinnability and quality, which is extremely useful. Further, the obtained acrylic synthetic fiber is excellent in fastness and can be used for many other purposes such as clothing and materials, and is industrially extremely significant.

Claims (1)

(57) [Claims] When spinning an acrylonitrile polymer containing carbon black, a highly condensed naphthalene sulfonate is previously dissolved in an organic solvent in an amount of 0.01 to 3% by weight based on carbon black, and then the carbon black is uniformly dispersed. And then adding the resultant solution to an acrylonitrile polymer spinning solution and spinning the solution to produce an acryl-based synthetic fiber containing carbon black having excellent spinnability.