JPS5940940B2 - activated carbon fiber plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a plate-like body made of activated carbon fibers, in particular, which prevents short fibers from falling off due to friction that occurs during use or installation as parts, and furthermore, prevents a decrease in the activation ability of the plate-like body. This invention relates to an improvement of an activated carbon fiber plate-like body capable of preventing the above-mentioned problems.

Regarding only the constituent parts of activated carbon fibers (hereinafter abbreviated as ACF), the plate-like body of the present invention is formed into a plate-like shape in which the individual fibers of the ACF are intertwined and cannot be easily separated by hand. .

Therefore, the product of the present invention can be used for general purpose masks; gas masks worn by workers at sites where dust and toxic gases are generated; deodorizing materials for human bodies; adsorbent materials for air purifiers; adsorbent materials for tap water purification; It is widely used for heat insulation materials, soundproofing materials, etc. However, depending on their use, the lever plate-like bodies
F is closely intertwined to form a plate-like body, for example, woven fabric, felt, or other thick or thin non-woven fabric that is carbonized as it is, or fibers that are more gently intertwined than those mentioned above. They are made into plate-like bodies in various forms, such as those that are intertwined, such as gauze-like or stable cotton plate-shaped. Although ACF itself is not particularly fragile, it is inferior in various strengths compared to general clothing fibers. When friction or other external force is applied to the inside, fine fibers of ACF may fall off.

Although the amount is not so large, it causes undesirable results such as environmental contamination during handling, or contamination of cleaning products when used in masks, air purifiers, water treatment, etc. The inventors of the present invention have conducted extensive research to overcome these disadvantages, and have now completed the present invention. That is, the present invention uses AC which is a material fiber.
The object of the present invention is to provide an ACF plate-like body that prevents fine fibers from falling off during handling or use without impairing F adsorption activity or other inherent properties.

However, the purpose of this lever is that the ACFs are entangled to form a plate-like body, the plate-like body is coated with a dilute dispersion of synthetic resin with a concentration of 0.01 to 5%, and the dispersion medium h3
This is achieved by using an ACF plate-like body which is removed by volatilization.

The ACF used in the plate-shaped body of the present invention may be any material fiber activated to carbonize as long as it can be made into activated carbon fiber.

Examples of the material fiber include phenol resin, cellulose, lignin-poval, and acrylic fibers, with phenol resin being preferred. Phenol resins are made by reacting phenols such as phenol and cresol with aldehydes such as formaldehyde and acetaldehyde under acidic catalysts such as hydrochloric acid, sulfuric acid, and acetic acid.
It is obtained by spinning this into a fiber and then curing it with a suitable means, such as aldehyde or hexamethylenetetramine. Specific examples of the phenolic resin fiber manufacturing method are as follows.

First, a novolac resin (average molecular weight about 500 to 1200) is prepared by a conventional method from less than 6 moles of formaldehyde per 7 moles of phenol using a sulfuric acid catalyst.

This product is permanently meltable and soluble. The resulting novolac resin (e.g. molecular weight approximately 850
) is heated and melted (for example, at about 135° C.), passed through an orifice (for example, about 1.9 mwL in diameter), and spun at a speed of, for example, about 90 m/min to obtain fibers. The fibers are then cured, and the curing process can be carried out in either the gas phase or the liquid phase. An example of a liquid phase case is hydrochloric acid 18% and formaldehyde 18%.
The fibers are immersed in an aqueous solution containing 5%, the solution temperature is raised to 40°C, and then the temperature is increased successively to 60°C to LIOO°C.
The thus cured fibers are taken out, washed with water, dried, and cut into appropriate lengths to obtain a stable. The above method uses novolac resin, but the reaction is performed with phenol in the presence of an excess of formaldehyde and an alkaline catalyst such as caustic soda to form a resol resin, which is then melt-spun and further hardened to become a material fiber. You can also.

In order to activate carbonization of such raw material fibers, for example, the following treatment is performed. That is, to explain the case of obtaining a product in the form of felt as an example, felt is made from the above-mentioned material fibers, and it is heated for 500 minutes in an inert atmosphere such as nitrogen gas.
℃ or higher, preferably 800℃ or higher. The heating rate is preferably sufficiently slow, for example from 20 to 500°C/hour. Next, the carbon fibers are activated by heat treatment in an active gas atmosphere containing gases such as oxygen and water vapor. Alternatively, in the carbonization process, both carbonization and activation steps can be performed simultaneously by using an active gas. Although the method for producing ACF from phenolic resin has been described above, ACF can also be produced from other fiber materials according to conventionally known techniques.

Synthetic resins used in the present invention include thermoplastic resins such as polyvinyl acetate, polyacrylate, and cyanoacrylate; thermosetting resins such as phenol resin, epoxy resin, xylene resin, melamine resin, and polyurethane; SBR, and polyurethane; Any rubber-based material such as chloroprene can be used.

Particularly preferred are polyacrylates, polyurethanes and SBR. However, the resin used is
It is selected as appropriate depending on the intended use of the ACF plate. For example, when water resistance, solvent resistance, and durability H3 are particularly required, thermosetting resins such as urethane, unsaturated polyester, epoxy resin, urea resin, and melamine resin are preferred. or,
When flexibility is required, it is preferable to use a flexible material such as urethane or SBR. Furthermore, when used in masks, etc., materials that may be toxic, such as urea resin, phenol resin, and melamine resin, must be avoided. The term "dispersion liquid" used in the present invention includes a wide range of liquids, and both solutions and emulsions can be used.

Water and organic solvents can be used as the medium. The concentration of synthetic resin in the dilute dispersion is important in order to prevent the shedding of very short fibers without compromising the adsorption capacity and other desirable inherent properties of ACF. Although it varies slightly depending on the type of resin, it is important that the concentration is usually in the range of 0.01 to 5%, preferably 0.05 to 2%.
, more preferred is a concentration of 0.05-1%, ゜5%.
If the concentration exceeds 100%, the adsorption capacity will decrease and it is not practical. Furthermore, if the above concentration is less than 0.01%, the prevention of fine fibers from falling off, which is the objective of the present invention, cannot be achieved.
Covering methods for ACF in dilute dispersions include dipping, coating, and spraying.

Further, the coating may be applied to a plate-shaped object, for example, one formed of felt or other woven fabric, or may be applied to a cotton-like ACF and then the plate-shaped object is coated. However, it is preferable to use woven fabric, felt, or other nonwoven fabric as the raw material fiber, and to sequentially carbonize, activate, and coat with synthetic resin. After coating, the medium is volatilized and removed by drying treatment at room temperature or by heating. At this time, if you want to heat cure the resin,
A temperature higher than the thermosetting temperature of the resin is used. The ACF platelets thus obtained retain their active capacity and other inherent desirable properties, and shed significantly fewer or no short fibrils than before treatment. Next, the present invention will be explained in more detail using Examples, but the present invention is not limited by these Examples unless the gist of the invention is exceeded. Examples 1-10 These examples illustrate the use of various types of coating resins and dilute dispersions of various concentrations.

In this example, a felt made of novolac resin fibers activated to carbonize was used. That is, as explained above, a molten novolac resin having a molecular weight of 850 is spun,
This is cured in a hydrochloric acid-formalin aqueous solution, and the thus obtained novolac resin fiber has a thickness of 5 nm and a bulk specific gravity of 0.
Make felt of 11g/Cc. This felt is placed in a vertical electric furnace, heated to 900°C at a heating rate of 200°C/hour, and then held at 900°C for 30 minutes. At this time, when the temperature inside the furnace reaches 300° C., steam is introduced into the furnace, and charcoal FL activation is also performed. The thickness thus obtained is 4 mm (1)
The ACF felt plate was cut into a size of 40 x 70 mm and used as a sample piece for each test. Carbonization and activation were carried out under the same conditions, but the specific surface area (which is a measure of absorption characteristics) (hereinafter S
(abbreviated as N2) are slightly different from each other as shown in the column of untreated SN2 in the table below. Each of these sample pieces was immersed for 30 minutes in a dilute dispersion of resin and concentration shown in the table below. Take this out and leave it at room temperature for 1 hour, then
It was heated and dried at 0° C. for 1 to 2 hours. Regarding this, the abrasion test (Note 2) and SN
2 measurements were performed. The results are shown in the table below. From the above examples, it can be seen that the plate-like body of the present invention can significantly reduce the degree of wear without substantially impairing the adsorption properties.
"it is obvious.

Example 11 This example describes the case where an ACF plate was coated with synthetic resin solutions of various concentrations.

SN2l7lO7 prepared as described in Example 1
A sample piece of size 20 x 30 x 4n was taken from a felt of phenolic resin-based activated carbon fiber of 7l''/θ.
After immersing 10% acrylic polymer (Coponil DF-42T manufactured by Nippon Gosei Kagaku Co., Ltd.) in ethyl acetate solution for 2 minutes,
It was dried at room temperature for 1 hour and then at 100° C. for 1 hour.

Even when the product thus obtained was strongly rubbed by hand, no fine powder was generated. In addition, as shown in the table below, SN2 treated with 5% concentration retains about 50% of its original content, while SN2 treated with 10% concentration loses active H.
3 has been significantly lost. Resin concentration After treatment SN2 (m”/
I) l% 1,1605 %800 10%80 Example 12 SN224OOT produced as described in Example 1
A sample piece of 40 x 40 x 4 mm was taken from felt of phenolic resin activated carbon fiber of rl/θ, and an acetone solution of block type curable urethane resin with a concentration of 2% was applied to it with a brush, and the sample was heated at room temperature for 1 hour. It was dried at 130° C. for 1 hour.

The product obtained in this way does not produce fine powder even when rubbed, and has an SN2
was 1650d/9, and the adsorption properties were maintained. Prior to the present invention, as a manufacturing method for carbon fiber products, carbon fibers and monomers were added to a solvent and the monomers were polymerized, or the monomers were adsorbed onto carbon fibers and then the monomers were polymerized. There is a known force method in which a monomer polymer is formed on the surface of carbon fibers by polymerizing carbon fibers, and this is pressed under heating to form a molded product (Japanese Patent Laid-Open No. 48-88162). ).

However, when the monomer is polymerized on the surface of carbon fibers as in this method, when the object to be treated is ACF, a fatal disadvantage arises in that its activity is significantly reduced. In order to clarify this, a comparative example is shown below. Comparative Example 14 mm thick felt-like ACF (same as Example 1, made of novolac resin fiber) (specific surface area 1000
i/g) 5m7! Cut into L angle 5.1041y
was dispersed in 500 g of n-hexane, 601 g of methyl methacrylate monomer and 0.65 g of benzoyl peroxide (10% water content) were added, and the mixture was reacted with stirring at 70° C. for 5 hours.

After the reaction, suction filtration was performed through a 10μ filter, and the resulting filtration residue was dried at 130°C. The weight of the filter residue after drying is 5.4
776g, and 7.3% of the polymer was converted into ACF by the reaction.
It turned out that it was attached to the top. When the specific surface area of this material was measured, it was found to be 2.677z''/9, which revealed that the active ability was completely lost. Comparative Example 2 The same felt-like ACF6.l2939 as in Comparative Example 1 was −
After dispersing in 500 mt of hexane, 59 mt of methyl methacrylate monomer and 0.0 mt of benzoyl peroxide (10% water content) were added.
069 was added thereto, and the mixture was reacted at 70° C. for 3 hours with stirring.

After the reaction, suction filtration was performed using a 10μ filter, and the resulting filtration residue was dried at 130°C. The weight of the filter residue after drying was 6.1825 g, which means that 0.87% of the polymer was deposited on the ACF as a result of the reaction. When I measured the specific surface area of this thing, it was 677Tr? /9, indicating that the active ability of H5 was significantly reduced. It is clear that polymerization of monomers on the surface of ACF significantly impairs the active ability of ACF.

Claims (1)

[Claims] 1 Activated carbon fibers are intertwined with each other to form a plate-like body, the plate-like body is coated with a dilute dispersion of synthetic resin with a concentration of 0.01 to 5%, and the dispersion medium is removed by volatilization. Activated carbon fiber plate.