JPH07207524A - Acrylic synthetic fiber excellent in light resistance - Google Patents

Abstract

PURPOSE:To obtain an acrylie synthetic fiber, good in dyeability and operating efficiency and excellent in light resistance. CONSTITUTION:This method for producing an acrylic synthetic fiber is to comprise 0.1-5.0wt.% rutile type titanium dioxide, having <=0.45mum particle diameter and containing silicon at a ratio of >=2wt.% expressed in terms of SiO2 to the titanium dioxide in an acrylonitrile-based polymer.

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 having excellent light resistance.

[0002]

2. Description of the Related Art Acrylic synthetic fibers are widely used for clothing and bedding because of their excellent texture and dyeability. However, under the present circumstances, the fibers are easily yellowed by light or heat, and are subject to various practical restrictions. In particular, modacrylic fibers containing chlorine as a copolymerization component have a problem that they are easily yellowed by light or heat.

In order to improve such a problem, for example, Japanese Patent Publication No. 2-15642 discloses a modacrylic fiber containing an ultraviolet absorber which is a benzotriazole compound,
Japanese Unexamined Patent Publication No. 2-33315 proposes modacrylic fiber to which organic tin is added, but in the case of wet spinning, the yield is poor due to the elution of the ultraviolet absorber and organic tin into the coagulation bath. There is a problem that the dyeability is adversely affected. Further, the use of rutile-type titanium dioxide to improve light resistance is performed in the paint field, but when applied to fibers, there is a problem in hardness and spinning operability, and in the fiber field, rutile-type dioxide is used. The current situation is that titanium is not used.

[0004]

As described above, although various means for improving the light resistance of acrylic synthetic fibers have been proposed, the acrylic synthetic fibers having excellent dyeing properties and operability and excellent light resistance have been proposed. No fiber is obtained.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an acrylic synthetic fiber which has good dyeability and operability and is excellent in light resistance.

[0006]

Means for Solving the Problems The above-mentioned object is to obtain an acrylonitrile-based polymer having a particle diameter of 0.45 μm or less and a silicon dioxide of SiO _{2 in} terms of titanium dioxide content of 2.
0.1 to 0.1% by weight of rutile titanium dioxide
This is achieved by an acrylic synthetic fiber having improved light resistance, which is characterized by containing 5.0% by weight.

The present invention will be described in detail below.

The acrylonitrile-based 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, 30% by weight or more of acrylonitrile 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 styrene sulfonate, 2
-Acrylic-2-methylpropane sulfonic acid soda and the like are appropriately combined and copolymerized at a ratio of 70% by weight or less. Particularly, a copolymer of acrylonitrile of 80% by weight or more and 20% by weight or less of a vinyl-based monomer and a sulfonic acid group-containing monomer, 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 method of polymerizing the polymer used in the present invention may be any known method such as aqueous polymerization, emulsion polymerization and solution polymerization.

The rutile type titanium dioxide used in the present invention is required to have a particle size of 0.45 μm or less. If the particle size exceeds 0.45 μm, the operability is remarkably deteriorated and the light resistance is not improved. In addition, silicon (S
It is necessary for i) to be contained in an amount of 2.0% by weight or more as SiO _{2 with} respect to the amount of titanium dioxide, which improves the dispersibility in the dispersion medium and makes the dispersion of titanium dioxide in the fiber uniform. Good light resistance is obtained, and hardness is hardly affected. When silicon is less than 2.0% by weight as SiO ₂ , dispersibility in the dispersion medium is poor and dispersion in the fiber becomes non-uniform, which causes a problem in operation.
Furthermore, it is necessary that the rutile titanium dioxide is contained in an amount of 0.1 to 5.0% by weight based on the acrylonitrile polymer. If the amount of rutile titanium dioxide is less than 0.1% by weight, good light resistance cannot be obtained, and if it exceeds 5.0% by weight, spinning becomes difficult.

Next, an example of a method for producing an acrylic synthetic fiber having excellent light resistance according to the present invention will be described. In the acrylic synthetic fiber of the present invention, rutile type titanium dioxide is uniformly finely dispersed in an organic solvent, and then added to an organic solvent solution of an acrylonitrile copolymer and spun to make fine powder uniformly contained in the fiber. The spinning method can be normal wet, dry, or dry / wet. Then, for example, in the case of wet spinning, it may be carried out under the same conditions as in the case of ordinary acrylic synthetic fibers.
Dry and post-process.

[0012]

EXAMPLES Next, the present invention will be described concretely by showing Examples. In the examples, “part” means “part by weight” and “%” means “% by weight”. The light resistance was measured and evaluated by spinning the obtained acrylic synthetic fiber into a No. 30 single yarn and then circular knitting, exposing it to a fade meter at 63 ° C. for 20 hours, and then discoloring ( The evaluation was performed on a gray scale).

Examples 1 to 3, Comparative Examples 1 to 4 Acrylonitrile (AN) / methyl acrylate (M
A) A solution of acrylonitrile polymer consisting of sodium acrylamido-2-methylpropanesulfonate (SAM) = 91.2 / 8.0 / 0.8 in dimethylformamide (DMF) was prepared as a spinning stock solution. . Then, 15% by weight of rutile type titanium dioxide having a particle size of 0.20 μm and containing silicon (Si) as SiO ₂ in a predetermined amount relative to the amount of titanium dioxide was uniformly dispersed in DMF. Titanium dispersion was added to a predetermined amount to prepare a spinning dope. Then, the spinning dope is kept at 20 ° C. and 60 ° C.
% DMF aqueous solution, drawn while being desolvated, and subjected to a washing process with water, a fiber oil agent was applied thereto, and then dried and densified at 150 ° C. using a roller dryer. Next, after the mechanical crimp was applied, the crimp was set at 115 ° C. under moist heat. The obtained fiber was cut and then spun to make a circular knit fabric. The fiber was evaluated by the method described above. The results are shown in Table 1.

[0014]

[Table 1]

As can be seen from Table 1, the products of Examples have superior light resistance to the products of Comparative Examples.

Examples 4 to 7, Comparative Examples 5 to 8 Acrylonitrile (AN) / vinylidene chloride (VC)
l ₂ ) / 2-acrylamido-2-methylpropanesulfonic acid sodium (SAM) = 53/44/3, an acrylonitrile polymer dimethylformamide (DM)
F) A solution was prepared and used as a spinning dope. Then, rutile titanium dioxide 15 having a particle diameter of 0.20 μm and containing silicon (Si) as SiO _{2 in a} predetermined amount relative to the amount of titanium dioxide 15.
After uniformly dispersing wt% in DMF, a titanium dispersion was added so that a predetermined amount of titanium dioxide was added to the polymer to prepare a spinning dope. After that, the spinning solution is added to 20 ° C and 60% DMF.
The solution was spun into an aqueous solution, stretched while being desolvated, and washed with water. Then, a fiber oil agent was applied, and then dried and densified at 150 ° C. using a roller dryer. Next, after the mechanical crimp was applied, the crimp was set at 115 ° C. under moist heat. The obtained fiber was cut and then spun to make a circular knit fabric. The fiber was evaluated by the method described above.
The results are shown in Table 2.

[0017]

[Table 2]

As is clear from Table 2, the products of Examples have superior light resistance to the products of Comparative Examples.

[0019]

INDUSTRIAL APPLICABILITY The acrylic synthetic fiber having excellent light resistance of the present invention has a high degree of light resistance, and has ordinary dyeability, operability, etc., and thus is very useful. Further, the fibers obtained by the present invention can also be used as a mixture with other fibers such as ordinary acrylic synthetic fibers, polyester, nylon, cotton, rayon, wool, and carpets that require light resistance, Since it can be used for a wide range of purposes such as curtains, it is extremely meaningful industrially.

Claims (1)

[Claims] 1. A rutile-type titanium dioxide having a particle size of 0.45 μm or less and containing silicon as SiO _{2 in an} amount of 2.0% by weight or more based on the amount of titanium dioxide with respect to an acrylonitrile-based polymer. An acrylic synthetic fiber having excellent light resistance, which is characterized by containing 0.0% by weight.