JPH07216641A - Acrylic synthetic yarn having excellent whiteness - Google Patents

Abstract

PURPOSE:To obtain an acrylic synthetic yarn having excellent handle, dyeability, operation efficiency and whiteness. CONSTITUTION:An acrylonitrile-based polymer is mixed with 0.1-5.0wt.% of rutile-type titanium dioxide having <=0.45mum particle diameter and containing silicon as SiO2 in the ratio to titanium dioxide of >=2.0wt.% and >=0.01wt.% of 9,10-dihydro-4-oxo-10-phosphaphenanthrene-10-oxide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acrylic synthetic fiber excellent in whiteness.

[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, the present condition is that the stability against heat is poor, and yellowing easily occurs in processes involving heating such as polymer dissolution and fiber drying, and various practical restrictions are imposed. For this reason, methods for changing the composition of the polymer, methods for changing the production conditions, methods for adding a stabilizer to the spinning dope, etc. have been studied in the past, but no excellent whiteness has been obtained. The current situation. Further, a post-treatment, for example, a method of bleaching with sodium hypochlorite has been studied, but it has a drawback that the texture becomes poor.

[0003]

Although various means for improving the whiteness of acrylic synthetic fibers have been proposed as described above, they have good feeling, dyeability and operability.
Acrylic synthetic fibers with excellent whiteness have not been obtained.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide an acrylic synthetic fiber which is excellent in feeling, dyeability and operability and is excellent in whiteness.

[0005]

Means for Solving the Problems The above object is to obtain an acrylonitrile-based polymer having a particle diameter of 0.45 μm or less and silicon of SiO _{2 in} terms of titanium dioxide content of 2.
0.1 to 0.1% by weight of rutile titanium dioxide
Excellent whiteness characterized by containing 5.0% by weight and 0.01% by weight or more of 9-10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide. Achieved by acrylic synthetic fiber.

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 their alkyl esters, vinyl acetate, vinyl chloride, vinylidene chloride, sodium allyl sulfonate, sodium methallyl sulfonate, vinyl sulfone. Acid soda, styrene sulfonate sodium, 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 10% by weight of the contained monomer is preferable.

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

The rutile titanium dioxide used in the present invention must have a particle size of 0.45 μm or less. If the particle size exceeds 0.45 μm, the operability is remarkably deteriorated and it does not contribute to the improvement of light resistance. 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 can be 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 the dispersion in the fiber is non-uniform, which is a problem in operation.
Further, it is necessary that the rutile titanium oxide is contained in an amount of 0.1 to 5.0% by weight based on the acrylonitrile polymer. When the amount of rutile type titanium oxide is less than 0.1% by weight, good light resistance cannot be obtained, and when it exceeds 5.0% by weight, spinning becomes difficult.

9-10-dihydro-9 used in the present invention
-Oxa-10-phosphaphenanthrene-10-oxide is represented by the following structural formula (1).

[0011]

[Chemical 1]

Such 9-10-dihydro-9-oxa-
The content of 10-phosphaphenanthrene-10-oxide is 0.01% by weight or more, preferably 0.01 to 2.0% by weight, more preferably 0.05 to 1.0% by weight, based on the acrylonitrile polymer. It is necessary to be contained. If it is less than 0.01% by weight, the effect of preventing coloration cannot be obtained,
On the other hand, if used in a large amount, coloring may increase, which is not preferable.

Next, an example of the method for producing an acrylic synthetic fiber having excellent light resistance of the present invention will be described. The acrylic synthetic fiber of the present invention is uniformly finely dispersed in an organic solvent of rutile type titanium dioxide, and then added to a solution of an acrylonitrile copolymer in an organic solvent, and 9-10-dihydro-
9-oxa-10-phosphaphenanthrene-10-
By adding oxide and spinning, rutile type titanium dioxide and 9-10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide are uniformly contained in the fiber. Spinning method is normal wet type, dry type,
Both dry and wet are possible. 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 fiber, and the drawing, washing, drying and post-treatment are sequentially carried out through a bath of several stages.

Incidentally, 9-10-dihydro-9-oxa-1
The method of adding 0-phosphaphenanthrene-10-oxide may be either directly added to the spinning stock solution or dissolved in an organic solvent and added to the stock solution, and is not particularly limited. In some cases, the fibers may be added in a gel-swelled state after spinning in an emulsion state using an emulsifier, followed by drying and densification.

[0015]

EXAMPLES Next, the present invention will be specifically described by showing examples. In the examples, “part” means “part by weight” and “%” means “% by weight”. For the measurement and evaluation of whiteness, the obtained acrylic synthetic fiber was spun by a conventional method to form No. 30 single yarn and then circular knitted, and evaluated by Hunter whiteness in a color difference meter. The light resistance was measured and evaluated by circular knitting at 63 ° C.
Exposure in a fade meter for 20 hours and evaluated by discoloration (gray scale).

Examples 1-5, Comparative Examples 1-4 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. The titanium dispersion liquid was added so as to have a predetermined amount. Further, 9-10-dihydro-9-oxa-
10-phosphaphenanthrene-10-oxide (trade name HCA: manufactured by Sanko Chemical Co., Ltd.) was added to the polymer in a predetermined amount to prepare a spinning dope. After that, the spinning dope is spun into a 60% DMF aqueous solution at 20 ° C., subjected to a drawing process while being desolvated, and a water washing process, and then a fiber oil agent is applied, and then dried and densified at 150 ° C. using a roller dryer. It was Next, after the mechanical crimp was applied, the crimp was set at 115 ° C. under moist heat. Cut the resulting fiber,
Then, after spinning, a circular knit fabric was produced. The fiber was evaluated by the method described above. The results are shown in Table 1.

[0017]

[Table 1]

As can be seen from Table 1, the product of the example is superior to the product of the comparative example in operability and has excellent whiteness. Further, it can be seen that the product of Example has excellent light resistance as compared with the product of Comparative Example.

[0019]

The acrylic synthetic fiber having excellent whiteness according to the present invention has a high degree of whiteness and excellent light resistance, and has ordinary feeling, dyeability, operability, etc. Very useful. The fibers obtained by the present invention are ordinary acrylic synthetic fibers, polyester, nylon, cotton,
It can be used as a mixture with other fibers such as rayon and wool, and can be used in a wide range of applications such as clothing requiring whiteness, which is extremely useful 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. 0.0% by weight and 9-1
An acrylic synthetic fiber having excellent whiteness, which comprises 0.01% by weight or more of 0-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.