JPS6158567B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing activated carbon fibers by carbonizing and activating vegetable fibers using vegetable fibers as raw materials.

Activated carbon fiber is an adsorbent that has recently attracted much attention because it is easier to handle than powdered activated carbon and has superior adsorption performance.

Conventionally, activated carbon fibers have been manufactured using acrylic fibers as raw materials. In this conventional method, acrylic fibers are first oxidized in an oxidizing atmosphere at a temperature of about 200 to 800° C. while applying tension for about 2 to 20 hours to make them sufficiently flame resistant. Then, this flame-resistant fiber is treated in a steam atmosphere at a temperature of about 900 to 1000° C. for about 20 minutes to 3 hours, thereby obtaining an activated carbon fiber.

However, in the conventional method, since acrylic fibers are used as raw materials, the flame resistance process takes a long time, and the activation process also takes a long time and has the disadvantage that the temperature also has to be high.

In view of these circumstances, the inventors of the present invention made extensive studies and found that they used vegetable fibers as raw material fibers and added zinc chloride to 100 parts by weight of vegetable fibers.
It has been found that excellent activated carbon fibers can be obtained by carrying 10 to 40 parts by weight of carbon fibers and then carbonizing and activating the fibers by firing at 450 to 650° C. in an inert gas atmosphere. Based on such knowledge, we have completed the present invention.

That is, the present invention provides an activated carbon fiber characterized by carrying 10 to 40 parts by weight of zinc chloride on 100 parts by weight of vegetable fibers, and firing, carbonizing, and activating this at 450 to 650°C in an inert gas atmosphere. This is a manufacturing method.

The vegetable fiber used in the present invention refers to all fibers made from plants, such as flocked fibers (e.g. cotton, kapok, bamboo cotton,
panya, vegetable silk, etc.), bast fibers (e.g. flax, hemp, juute, ramie, kenaf, mitsumata, etc.), leaf fibers (rows; Manila hemp, New Zealand hemp, sisal hemp, pita fiber, etc.), fruit fibers (e.g. ; coconut, etc.), others (e.g., straw, straw, seaweed sugamo fiber,
(irritability, etc.), such as viscose rayon,
Examples include cellulose-based regenerated artificial fibers such as cuprammonium rayon, and cellulose-based semi-synthetic fibers such as acetate and acetic acid sulphur. These fibers may be in the form of fibers, or may be formed into a fiber structure such as a woven fabric, a nonwoven fabric, or a felt paper.

In the present invention, first, zinc chloride is supported on the vegetable fiber.

Examples of means for supporting zinc chloride include immersing the vegetable fibers in a zinc chloride solution or spraying the vegetable fibers with a zinc chloride solution.

The amount of zinc chloride supported is preferably 10 to 40 parts by weight, particularly about 15 to 30 parts by weight, per 100 parts by weight of dry raw fiber. The amount of zinc chloride in the zinc chloride solution is about 5~
40 parts by weight are preferred, especially about 10-30% by weight. The zinc chloride solution may be, for example, an aqueous solution or a solution containing alcohol or the like. Furthermore, hydrochloric acid or the like may be added to increase the solubility of zinc chloride.

If the amount of zinc chloride supported exceeds 40 parts by weight, the flexibility peculiar to the fibers cannot be obtained. Further, when the amount of zinc chloride impregnated is 10 parts by weight or less, not much adsorption power is imparted.

Next, in the present invention, the vegetable fibers carrying zinc chloride are fired at 450 to 650°C in an inert gas atmosphere to carbonize and activate them.

Carbonization and activation are approximately 0.25~ at a temperature of 450~650℃
This is carried out by baking for 2 hours, preferably about 0.5 to 1 hour. Carbonization and firing during activation are performed under an inert gas atmosphere such as nitrogen gas, combustion exhaust gas of heavy oil, light oil, kerosene, and the like.

The thus carbonized and activated vegetable fibers may be washed and dried by conventional methods, if necessary.

According to the present invention, activated carbon fibers with high yield and excellent flexibility and adsorptivity can be supplied at a much lower cost than conventional methods.

EXAMPLES The present invention will be specifically explained below with reference to Examples and Comparative Examples.

Example 1 Commercially available cotton cloth (bleached) was mixed with 25% by weight of zinc chloride.
After being immersed in an aqueous solution containing % by weight of hydrogen chloride for about 5 minutes, it was squeezed using a rubber roller to uniformly impregnate the chemical solution. Loaded amount of zinc chloride is 28g/100g
- It was made of raw material cloth. 16 pieces of raw material cloth impregnated with chemical solution
It was wound onto a mesh stainless steel wire mesh roll and fired at a temperature of 500°C in a nitrogen stream for about 0.5 hours. The fired product was cooled to around room temperature, washed and purified, and then dried at a temperature of 110° C. for 2 hours to obtain activated carbon fiber A with high flexibility. The activated carbon fiber A
The yield was 31%, and the equilibrium adsorption amount of 1000 ppm benzene vapor at 25°C was 32% by weight.

Example 2 Commercial linen cloth was mixed with 15% by weight of zinc chloride and 0.5% by weight.
After being immersed in an aqueous solution containing hydrogen chloride for about 5 minutes, it was dehydrated using a centrifuge to uniformly impregnate the chemical solution. The amount of zinc chloride supported was 24 g/100 g of raw material cloth. A highly flexible activated carbon fiber B was obtained in the same manner as in Example 1, except that the cloth was fired at a temperature of 650°C and a time of 1 hour. The yield of the activated carbon fiber B was 33%, and the equilibrium adsorption amount of 1000 ppm benzene vapor at 25° C. was 36% by weight.

Comparative Example 1 Commercially available cotton cloth (bleached) was mixed with 50% by weight of zinc chloride.
After being immersed in an aqueous solution containing % by weight of hydrogen chloride for about 5 minutes, a rubber roller was used to uniformly impregnate the squeeze chemical solution. The amount of zinc chloride supported is 52g/100g.
It was made of raw material cloth. This cloth was fired, purified, and dried in the same manner as in Example 1 to obtain activated carbon fiber C. The activated carbon fiber C had almost no flexibility as a fiber, and had properties similar to ordinary activated carbon rather than activated carbon fiber.

Claims (1)

[Claims] 1 100 to 40 parts by weight of zinc chloride is supported on 100 parts by weight of vegetable fiber, and this is heated to 450 parts by weight in an inert gas atmosphere.
A method for producing activated carbon fiber, characterized by firing at ~650°C.