JP2003105625A - Cellulose acetate fiber and method of production for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cellulose acetate fiber semipermanently emitting minus ions and to provide a method of production for the same. SOLUTION: The cellulose acetate fiber includes 3-15% of tourmaline having 0.5-5 μm of maximum particle diameter, and changes pH of an aqueous solution set pH=4 by a strong acid to pH=4.5 by soaking and shaking 2 wt.% (based on aqueous solution) of the cellulose fibers for 30 min and the method of production for the cellulose acetate fiber adding the tourmaline having 0.5-5 μm of maximum particle diameter in an amount of 3-15% by a wet dispersing method to the spinning stock solution of the cellulose acetate.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a cellulose acetate fiber which generates negative ions.

[0002]

2. Description of the Related Art Cellulose acetate fibers have a lower refractive index than synthetic fibers such as polyester fibers and polyamide fibers, and due to the complicated yarn surface morphology derived from their manufacturing method, they have excellent coloring and silky luster. It has a dry feeling and is widely used in the field of high-end women's clothing. However, in recent years, in the field of clothing, particularly in the field of women's clothing, diversification of fashion, diversification of consumer needs, and sophistication have been demanded, and various modification and improvement of cellulose acetate fiber have also been demanded.

Conventionally, the modification and improvement of cellulose acetate fibers are mainly aimed at improving the gloss and texture of the cross section and surface of the fiber by physical or chemical means, and are the main raw materials. There are very few examples in which a second component other than a certain cellulose acetate is contained in the fiber, and titanium dioxide is added by a known method for the purpose of reducing gloss, and in JP-A-7-341564, high specific gravity is obtained by adding barium sulfate. JP-A-2000-45123 only discloses a method for obtaining an acetate fiber and a method for obtaining a cationic dye-dyeable cellulose acetate fiber by adding a metal sulfonate group-containing dibasic fatty acid ester.

Further, in JP-A-6-104926, a method of containing or adhering tourmaline to a fiber to obtain far infrared radiation ability, and in JP-A-4-327207, a method of obtaining a chargeable rayon by incorporating tourmaline. However, there is no prior art of incorporating tourmaline into cellulose acetate fiber.

[0005]

SUMMARY OF THE INVENTION According to the present invention, by adding tourmaline to cellulose acetate fiber, p
It is to provide a cellulose acetate fiber capable of increasing H, that is, capable of semi-permanently generating negative ions.

[0006]

The first gist of the present invention is as follows.
The content of tourmaline having a maximum particle size of 0.5 to 5 μm is 3
When the cellulose acetate fiber of 2% by weight of the aqueous solution was immersed in an aqueous solution having a pH of 4 with a strong acid of 4% to 15% and shaken, after 30 minutes, the aqueous solution had a pH of 4.
It is in a cellulose acetate fiber of 5 or more.

The second aspect of the present invention is to provide tourmaline having a maximum particle size of 0.5 to 5 μm by wet dispersion.
A method for producing a cellulose acetate fiber is characterized in that the cellulose acetate spinning stock solution is added in an amount of 3 to 15%.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be specifically described below.

In the present invention, the maximum particle size is 0.5 to 5 μm.
It is necessary to contain 3 to 15% of tourmaline. When the maximum particle size is less than 0.5 μm, it is effective for improving the pH raising ability (minus ion generation efficiency), reducing yarn breakage, and securing physical properties after spinning, but the maximum particle size is 0.5 μm without aggregation. When using a known technique such as a horizontal bead mill, the bead mill processing time is remarkably extended and the manufacturing cost is significantly increased. If the maximum particle size exceeds 5 μm, yarn breakage occurs frequently, and it becomes difficult to produce yarn.

Further, the acetate fiber of the present invention must have a tourmaline content of 3 to 15%. If the content of tourmaline is less than 3%, the ability to raise pH is insufficient, and if it exceeds 15%, thread cutting tends to occur, and physical properties such as a decrease in elongation after spinning are deteriorated.

Further, in the present invention, when 2% of the weight of the aqueous solution is dipped in an aqueous solution having a pH of 4 with a strong acid and shaken, the aqueous solution has a pH of 4.5 or more after 30 minutes. is necessary.

When 2% of the weight of the aqueous solution was dipped and shaken, and after 30 minutes, when the aqueous solution had a pH of less than 4.5, there was almost no significant difference from the tourmaline-free yarn, and negative ions were generated. It is not practical because the amount hardly increases.

Examples of tourmaline used in the present invention include shawl tourmaline, lithia tourmaline, dravite tourmaline, and mixtures thereof.

The cellulose acetate fiber of the present invention may be a cellulose diacetate having an esterification degree of 2.22 or more and less than 2.76, or an esterification degree of 2.7.
Cellulose triacetate of 6 or more and less than 3.00 may be used.

Next, the method for producing the cellulose acetate fiber of the present invention will be specifically described.

In the present invention, the maximum particle size of tourmaline is set to 0.5 to 5 μm by wet dispersion, and the addition amount is 3 to 15%.
Therefore, it is necessary to add it to the cellulose acetate spinning dope.

As a method of adding tourmaline, a method of directly adding fine particle tourmaline to a cellulose acetate spinning stock solution can be considered, but in this case, it is necessary to previously control the maximum particle size to 0.5 to 5 μm by dry dispersion. Such fine particle powder is likely to be re-aggregated, and the powder finely divided by dry dispersion is apt to cause blocking during transportation or charging, and further, it is difficult to handle because a large amount of dust is generated. On the other hand, when wet-dispersed in a solvent for cellulose acetate, it can be handled as a liquid in practical use, and the wet-dispersed tourmaline is used together with the solvent during the production of the cellulose acetate spinning stock solution, or cellulose acetate prepared in advance. By adding the spinning dope to the spinning dope, it becomes possible to easily obtain the tourmaline-containing spinning dope.

As the wet disperser, a known method using a ball mill, a pearl mill, a bead mill or the like may be used, and in particular, a wet dispersion using a horizontal bead mill is preferably used in view of handleability and ease of setting dispersion conditions. Tourmaline with a maximum particle size of 0.5 μm to 5 μm is used for the bead filling rate of the horizontal bead mill, the bead diameter, the peripheral speed of the rotor blade
It can be obtained by appropriately setting the processing speed and the processing time.

The spinning solution is prepared by dissolving cellulose acetate in a single solvent such as acetone or methylene chloride or in methylene chloride /
Dissolve in a mixed solvent such as methanol to give cellulose acetate
The lower limit is 15% or more and the upper limit is 35% or less, preferably the lower limit is 18% or more and the upper limit is 30% or less, and this stock solution is wet with a single solvent such as acetone, methylene chloride, methanol or a mixed solvent such as methylene chloride / methanol. It can be obtained by adding dispersed tourmaline.

Spinning is preferably carried out by a dry spinning method in which a spinning dope is supplied to a spinneret device and discharged from a spinning nozzle into a high-temperature atmosphere, but a wet method of discharging from a spinning nozzle during coagulation of a non-solvent of cellulose acetate. You may perform by a spinning method. Further, during spinning, an ordinary spinning dope containing no tourmaline may be used in combination as a spinning dope, and composite spinning may be performed in a side-by-side type, a core-sheath type or the like. Also,
The fiber may have a circular or irregular cross-sectional shape, and the fiber may have a staple or filament shape.

[0021]

EXAMPLES The present invention will be described below with reference to examples.

The characteristic values were measured according to the following methods.

(Maximum Particle Size) The maximum particle size of the tourmaline slurry which has been finely divided by a horizontal bead mill is measured by a laser diffraction particle size distribution measuring device (LA-manufactured by Horiba, Ltd.).
500).

(Examples 1 to 3 and Comparative Examples 1 to 4) Cellulose diacetate having a degree of esterification of 2.41 was dissolved in a mixed solvent of methylene chloride / methanol (mixing ratio 88/12) to a concentration of 21.9. A spinning dope of weight% was prepared. Next, Lithia Tourmaline (made by I-Tech Co., Ltd.)
A horizontal bead mill (KDL-PILOT type manufactured by Shinmaru Enterprises Co., Ltd.) was used to prepare a tourmaline slurry in the above mixed solvent so that the maximum particle size was as shown in Table 1. This tourmaline slurry was added to the above spinning stock solution so that the amount of tourmaline was as shown in Table 1 with respect to the total solid content, to prepare a tourmaline-containing spinning stock solution.

Using this tourmaline-containing spinning dope, spinning was carried out at a spinning speed of 500 m / min by a dry spinning method to obtain 84 dt.
Ex / 20f filament yarn was obtained. Then, the obtained yarn was used to knit into a tubular knit. 2% of the weight of the solution was immersed in an aqueous solution adjusted to pH = 4 with hydrochloric acid and shaken. The pH was measured after each shaking time, and the obtained results are shown in Table 1. At this time, as a shaker, Recipro
Shaker SK-2S (manufactured by TAITEC), a Cyber Scan PH2000 (IUCHI) as a pH measuring device.
(Made by the company) was used.

Since Comparative Example 1 does not contain tourmaline, when a sample of 2% of the weight of the aqueous solution is immersed in an aqueous solution of pH = 4 with a strong acid and shaken, after 30 minutes, the pH =
It did not exceed 4.5.

In Comparative Example 2, the maximum particle size of tourmaline is 5 μm.
Since it exceeded m, thread cutting occurred frequently, and it became impossible to make yarn.

In Comparative Example 3, since the amount of tourmaline added exceeded 15%, the yarn elongation was difficult to put into practical use.

[0029]

[Table 1]

[0030]

INDUSTRIAL APPLICABILITY By adding tourmaline to the cellulose acetate fiber, the cellulose acetate fiber according to the present invention becomes capable of increasing pH, that is, semi-permanently generating negative ions.

Claims (2)

[Claims] 1. The content of tourmaline having a maximum particle size of 0.5 to 5 μm is 3 to 15%, and pH = 4 due to a strong acid.
A cellulose acetate fiber having a pH value of 4.5 or more after 30 minutes when 2% by weight of the aqueous solution is dipped and shaken in the aqueous solution. 2. The maximum particle size is 0.5 to 5 by wet dispersion.
A method for producing a cellulose acetate fiber, characterized in that tourmaline having a diameter of 3 μm is added to a cellulose acetate spinning dope at an addition amount of 3 to 15%.