JPH03122008A - Activated carbon sheet and its manufacturing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a highly functional activated carbon sheet that retains the adsorption performance of powdered activated carbon, and a method for producing the same.

[Conventional technology]

Activated carbon, which is commonly used as an adsorbent, is produced in the form of powder, granules, fibers, etc. Among these, powdered and granular activated carbon are essentially aggregates of carbon, so they are polluting and inconvenient to handle. In this respect, fibrous activated carbon obtained by activating carbon fibers is easy to handle due to its low contamination and flexibility, but it has a performance drawback in that it has a small adsorption capacity.

Powdered activated carbon has excellent adsorption ability, so if it could be formed into a pellet while maintaining its performance, the range of its uses would be significantly expanded.

Conventionally, notebooks using powdered activated carbon have been produced by wet-processing a slurry obtained by making cationic inorganic fibers, activated carbon powder, and anionic binder as essential components, and adding appropriate auxiliary materials as necessary. A method of making paper using a papermaking method (Japanese Patent Application Laid-Open No. 56-48242), a sheet structure in which powdered activated carbon is interposed as an inseparable integral structure between layers of rolled silk sg1lat woven material, and a manufacturing method (
JP-A-62-289659) has been proposed.

[Problem to be solved by the invention]

However, the method of JP-A-56-48242 has a short breakthrough (adsorption) life due to the small content of powdered activated carbon, and the sheet structure of JP-A-62-289,659 has a gas odor. It is difficult to use in the liquid phase because it targets the adsorption of harmful vapors.

The object of the present invention is to create an activated carbon sheet that can be used in gas-liquid sheets and at high and low temperatures without impairing the high adsorption capacity of powdered activated carbon, and that also has excellent non-dyeability and dyeability. The purpose is to provide a manufacturing method.

[Means for Solving the Problems] The activated carbon sheet according to the present invention for achieving the above object has a fibrillated fluororesin in the activated carbon structure.
Its structural feature is that it has a compositional form with t intervening.

The activated carbon structure constituting the present invention is, for example, ordinary powdered activated carbon made by activating raw coal made of coconut shells, sawdust, bulbs, coal, carbon blanks, etc., and has a particle size of 5.
It is preferable that the powder be a fine powder of 0 μm or less.

A fibrillated fluororesin refers to a fluororesin that has been converted into a fibrous form through a kneading process. Types of fluororesin with such properties include polytetrafluoroethylene, polytrifluoroethylene, and polyethylene that have fibrillation properties. Examples include vinylidene fluoride and polyolefin.

Therefore, the activated carbon sheet IJI composition of the present invention is formed as a composite in which the fluororesin dispersed in the tissue is intertwined in the form of fine fibers, and the powdered activated carbon is captured in a fiber network.

The manufacturing method according to the present invention for obtaining the above activated carbon sheet includes blending 1 to 10 parts by weight of a fibrillating fluororesin with 100 parts by weight of activated carbon powder having a particle size of 50 μm or less, and using water or/and alcohol as a kneading aid. The method is characterized in that the fluororesin is kneaded until fibrillated and then formed into a sheet.

It is important to use powdered activated carbon that serves as an adsorption base material that has been finely pulverized to a particle size of 50 μm or less; if the particle size exceeds 50 μm, smooth fibrillation of the fluororesin is inhibited and the resulting sheet becomes brittle.

The reason why a fibrillating fluororesin is blended in the range of 1 to 10 parts by weight per 100 parts by weight of activated carbon powder is that if the blending amount is less than 1 part by weight, the entanglement of the fiber network will be insufficient and the structure will not be strong. The sheet cannot be formed, and if it exceeds 10 parts by weight, the adsorption capacity will decrease and the sheet surface will deteriorate! 9
This is because it becomes water-based and worsens wetting.

These components are kneaded with water, alcohol, or a mixture thereof added as a kneading aid. The amount of the kneading aid added is preferably set in the range of 30 to 80 parts by weight per 100 parts by weight of powdered activated carbon.

The activated carbon powder, fluororesin, and kneading aid are kneaded until the fluororesin is fibrillated. Although there are no limitations on the equipment used for the kneading process, it is desirable to perform the kneading under shear stress.

The kneaded paste is formed into a sheet by, for example, using constant speed Niki rolls and passing between the rolls multiple times. The conditions in this case are that the roll rotation speed is 1 at room temperature.
It is preferable to set the speed to approximately rpm in order to perform smooth molding without cutting the fibrillated fibers.

[Function] The activated carbon sheet of the present invention has a diameter of 3 to 20 μm and a length of 10 μm.
It has a bonding form in which the activated carbon structure is captured and held within the entangled network of fibrillated fluororesin that has been converted into fine fibers of approximately 0 to 200 μm, and this unique form makes it easy to handle without impairing the high adsorption capacity of powdered activated carbon. It functions to provide convenient non-contamination and flexibility. Furthermore, the fluororesin that constitutes the fine fibers has excellent high temperature resistance and chemical resistance, so it can be widely applied regardless of conditions such as gas phase, liquid phase, high temperature, low temperature, etc.

Further, according to the manufacturing method of the present invention, the fluororesin fibrillated in the kneading process skillfully captures and integrates the powdered activated carbon within the entangled network in the sheeting stage, and smoothly forms the above-mentioned sheet structure form. .

〔Example〕

Hereinafter, the present invention will be explained based on examples.

Examples 1-2, Comparative Examples 1-2 Fibrillating polytetrafluoroethylene (PTFE) powder [Mikata DuPont [manufactured by Fluorochemical ■] was mixed in varying amounts, 63 parts by weight of water was added as a kneading aid per 100 parts by weight of activated carbon powder, and the mixture was charged into a bub mill type kneader.
The mixture was sufficiently stirred and mixed until the fluororesin was fibrillated.

Next, the kneaded paste was molded at room temperature using a constant speed two-roll molding machine. A sheet was formed by repeatedly passing the sample 10 times under rotation conditions of rpm.

The formed sheet was dried at a temperature of 80°C to a thickness of 40°C.
An activated carbon sheet with a 0μ surface was manufactured. The obtained activated carbon sheet had good non-contamination properties with no powder scattering during the handling process, and was flexible enough to be easily deformed.

Various performances were measured for each activated carbon sheet obtained.
Table 1 shows a comparison with the manufacturing conditions.

Table 1 Table notes: (1) Methylene blue, (2) Iodine.

Example 3 A stainless steel net (250 μm) was placed in the middle of a billet-type glass tube with a diameter of 7 km, and one activated carbon sheet of Example 2 was fixed thereon with a heavy spacer.

In this state, a methylene blue aqueous solution (1
χ) was pumped at 20mf/min, and samples were collected from the bottom of the glass tube at regular intervals at 670r.
Absorption analysis was performed at a wavelength of +m to determine the amount of water passing and methylene blue (M
B: lppm)) The relationship between adsorption amount (breakthrough curve) was measured.

The obtained breakthrough curve is shown in the figure. It was confirmed that the breakthrough curve shown in the figure shows the same high adsorption performance as powdered activated carbon.

[Effects of the Invention] According to the present invention, it has high adsorption performance equivalent to that of powdered activated carbon, and can be used in gas phase, liquid phase, and under high and low temperature conditions.
An activated carbon sheet having good non-staining properties and flexibility can be provided.

Therefore, it is useful for a variety of adsorption applications targeting gas and liquids, such as purification and purification of various liquids including tap water, and purification of smoke gases generated from smoking, cooking, and the like.

[Brief explanation of drawings]

The figure shows a breakthrough curve of a methylene blue aqueous solution using the activated carbon sheet of the present invention.

Claims (1)

[Scope of Claims] 1. An activated carbon sheet having a composition in which fibrillated fluororesin is dispersed in an activated carbon structure. 2. Blend 1 to 10 parts by weight of a fibrillating fluororesin with 100 parts by weight of activated carbon powder with a particle size of 50 μm or less, knead with water or/and alcohol as a kneading aid until the fluororesin fibrillates, and then form into a sheet. A method for producing an activated carbon sheet, which comprises forming it.