JPS58213613A - Preparation of spherical active carbon - Google Patents

Abstract

PURPOSE:To prepare a spherical active carbon having high strength, large specific surface area and excellent adsorptivity, by emulsifying a thermosetting resin prepolymer in water, polymerizing and curing the prepolymer by a specific method, and carbonizing and activating the resultant spherical resin. CONSTITUTION:A condensation-type or addition-polymerization-type thermosetting resin prepolymer (e.g. phenolic resin prepolymer, epoxy resin prepolymer, etc.) (which may be compounded with a curing agent, a filler, a stabilizer, etc.) is emulsified in water in the presence of a surface active agent under agitation. The agitation is continued to fuse the emulsified resin particles with each other and increase the particle diameter while the prepolymer is still sufficiently fluid. The fused particles are cured in the suspension to obtain spherical thermosetting resin having an average particle diameter of about >=2,000mu. The obtained spheres are carbonized by heating in an oxygen-free atmosphere at >=500 deg.C, and activated with e.g. steam to obtain the spherical active carbon.

Description

Detailed Description of the Invention The present invention uses condensation type or polyaddition type thermosetting resin polymers such as phenolic resins, melamine resins, and epoxy resins.
If necessary, curing agent, curing catalyst, filler, foaming agent, coloring agent,
A thermosetting resin that is made by emulsifying it in water with stirring using an emulsifier together with a stabilizer, etc., then heating it if necessary to increase the viscosity and particle size, and then proceeding with the reaction while continuing to stir to harden it. A thermosetting resin product characterized by carbonizing a spherical material by heating it to 500°C or higher in the absence of oxygen gas, and then activating it in a stream of water vapor, carbon dioxide gas, and/or oxygen/nitrogen mixed gas. This article relates to a method for producing spherical activated carbon from granules.

Emulsions of various thermosetting resins have traditionally been produced in large quantities as adhesives and paints, but when the reaction time is increased or the concentration of the resin component or the reaction temperature is increased, the particles adhere to each other and agglomerate. Then, it becomes a mochi-like or cylindrical lump.
Since the cured product is egg-shaped or even string-like, there is a limit to increasing the particle size without maintaining a shape close to a true sphere, and even if various measures are taken, there is a limit to increasing the particle size. 200μm
It has been extremely difficult to obtain a solid substance that is close to a perfect sphere with an average particle diameter of the above value.

As a result of the inventors' intensive study on this point,
Various thermosetting resins used! The repolymer liquid or solution is once emulsified by stirring vigorously in water, using an emulsifier if necessary, and the emulsified resin particles are fused together while the thermosetting resin molecules retain sufficient fluidity. It was discovered that the average particle size of the thermosetting resin particles could be increased to about 2000 pm by curing the particles by curing the particles while maintaining the suspended state. Resin spheres were heated for 50 minutes in the absence of oxygen.
It was discovered that spherical activated carbon could be obtained by carbonizing it by heating it to 0°C or higher, and then activating it in a stream of slightly oxidizing gas such as water vapor, carbon dioxide gas, and/or oxygen/nitrogen mixed gas, and completed the present invention. did.

Examples of condensation type thermosetting resin polymers that can be used in this process include novolac type phenolic resin prepolymer, resol type phenolic resin gray polymer, nolac type alkyl phenol resin gray polymer, resol type alkyl phenol resin gray polymer, These xylene/formaldehyde condensates, toluene/formaldehyde condensates, melamine resins, guanamine resins, 2
Or urea resin-modified resin Breteimer 2 melasun resin prepolymer, urea resin! There are repolymers, urea-modified melamine resin sag 4 remers, guanamine resin ble polymers, guanamine-modified melamine resin sag polymers, etc., and if necessary, curing agents, curing catalysts, etc. can be mixed together for use.

Polyaddition type thermosetting resin that can be used in the present invention! As repolymers, solid or There are liquid epoxy resins such as grepolymer and mer, which are used as reactive diluents such as diglycidyl ethers of polymethylene glycol, polyglycidyl compounds of polyhydric phenols and aromatic polycardic acids, and non-reactive diluents. Toluene, xylene, various alkylbenzenes such as ethylbenzene used as diluents, various alkylphenols, long-chain aliphatic esters, alkyl esters of alkylphenols and alkylbenzoic acids, hyalkyl ethers, alcohols, amines, organic acids It can be used by adding organic oily or liquid substances such as, to these so-called main ingredients, various polyamide polyamine type, aliphatic, aromatic or alicyclic / IJ amine type and / or various types of #1 or tolylene diisocyanate (TDI), which can be used by adding and mixing various curing agents such as acid anhydride type and, if necessary, curing catalysts such as amine type and metal complex type. , diphenylmethane diisocyaner) (MD
I) Polyvalent active hydrogen low polymers such as various polyethers, polyesters, and polyamides are added to various aromatic or aliphatic polyisocyanates such as hexamethylene diisocyanate and its adducts. A urethane-based sagging polymer made by adding a combination of, if necessary, a hydrophobic aromatic or aliphatic solvent/agent, various curing catalysts such as amine-based or metal complex-based curing catalysts, and further carrying out a partial reaction if necessary. etc.

The present invention is characterized by emulsifying various types of polymers in water. For this purpose, one or more surfactants selected from anionic, cationic, and neutral surfactants may be used. Although an agent may be used as an emulsifier, there are also systems that emulsify by stirring without adding an emulsifier, such as an epoxy resin brepolymer combined with an I-lyamide polyamine curing agent.

In addition, various inorganic powder fillers such as calcium carbonate, talc, glass powder, and silicon oxide, various organic powder fillers such as starch-based and cellulose-based powders, and wood flour, By adding blowing agents such as diazo, peroxide, low molecular weight paraffin, or fluorine compound, antioxidants, ultraviolet absorbers, various stabilizers, etc., the viscosity, reactivity, specific gravity, etc. of the brepolymer can be adjusted. In addition, it is of course possible to produce activated carbon by carbonizing and activating the resulting spherical cured product by modifying and adjusting the stability, appearance, specific gravity, expansion ratio, etc. of the resulting spherical cured product.

The present invention will be explained below by way of examples.

Example 1 Bisphenol A diglycidyl ether type liquid epoxy resin with an epoxy equivalent of 190! Revo-Omer 2001, 100 F, 2,4.6-) lith dimethylaminomethylphenol of 100 F, 2,4.6-) liruonic acid dimer-based liquid polyamide curing agent having an active hydrogen equivalent of 120 were mixed, and further 10 F of methanonyl
After adding 00- and stirring uniformly, it was placed in a 2-t flask containing 1 t of deionized water at ω℃, 300 r, p, m.
It was added at 1 o'clock while stirring with , and emulsified.

While stirring at the same speed, the mixture was gradually heated to 19° C. over 5 hours, and the rotation speed was lowered to 20 Or, I), m, and the reaction was continued under the same conditions for a further 8 hours. The reaction product was collected by filtration, washed with water, and dried to obtain a perfectly spherical, light brown, transparent cured resin product in quantitative yield. The particle size distribution of this spherical resin has a peak around 0.8 φ, and is 0.50 to 1.
The 68 mφ accounted for 62% of the total product.

The cured product with a particle size within this range was placed in a porcelain bolt, heated in an electric furnace for 10 hours each at 120°C and 200°C, and then heated at 200°C/h while blowing nitrogen gas.
The temperature was raised to 700°C at a rate of
The hard spherical activated carbon was transferred to a trap in a rotary furnace of 0 ■φ and heated at 900°C for 8 hours in a stream of steam and air at a rate of 21/min to activate the hard spherical activated carbon at a rate of 6.
Obtained at 3%.

Example 2 Phenol/cresol (7
50% methanol/water (
Add 40 f of a 20% methanol solution of naphthalene disulfonic acid as a curing agent to 400 v of the solution, stir well, and add 0.8 t of I-rivinyl alcohol 2F with a degree of polymerization of 300 dissolved in a 2 t flask. of deionized water with stirring at 45° C. and 350 r,p,m at 1 hour. It instantly becomes a stable emulsified state, but it is heated to ω℃ in 1 hour, and the stirring speed is increased to 250 r.
, p, m, and K were lowered, and the reaction was further allowed to proceed for 4 hours under the same conditions. The product was separated, washed with water, and air-dried to obtain brown transparent spherical resin particles in quantitative yield. □This spherical resin particle is 0.
It shows a distribution close to a normal distribution with a peak around 7 mφ, and those with a sawφ of 0.42 to 1.00 account for 5% of all granules.
It accounted for 9%.

The spherical resin cured product in this range was cured, carbonized, and activated under the same conditions as those used for fallen trees to obtain spherical activated carbon with an activation rate of 57.

Example 3 V3 of trimethylolpronoyant TD (molar ratio)
Adduct 75 butyl thiacetate solution 18091 phthalic acid/
A 200F solution of a hexafunctional polyester polyol with a molecular weight of 2000 synthesized from anovic acid (80/20 molar ratio), ethylene glycol, and a small amount of glycerin, -) A 10% butyl acetate solution of lauryltin dilaurate 0.21 Mix and stir well, and separately add 11 polyvinyl alcohol (degree of polymerization 300)
1 t of deionized water dissolved in 300 rJl at room temperature.
The mixture was immediately poured into a 2-t flask equipped with a gas outlet, which had been stirred at , m, and after emulsification, was further stirred for 2 hours under the same conditions.

The stirring speed was lowered to 20 Or, p, m, and the temperature was gradually raised to ω°C in 2 hours, and the reaction was continued at the same temperature for an additional 4 hours. The cured resin was separated by F, washed with water, and air-dried to obtain pale yellow and translucent spherical resin particles in quantitative yield. The diameter of this spherical object ranges from 0.02 to 1.6 φ, with a diameter of 0.71
It showed a distribution close to normal distribution with a peak around 1IIφ.

The particles with a particle size of 0.6 to 1.6 wsφ are classified and further refined [4
After curing by heating at 20°C and then at 200°C for 10 hours each, it was carbonized under the same conditions as in Example 1, transferred to the rotary furnace used on the same side, and heated at 1000 °C in a carbon dioxide gas flow of 2z/min.
Activation was carried out for 1.5 hours at t:: to obtain spherical activated carbon with an activation rate of 78%.

Comparative Example 1 Bisphenol A diglycidyl ether type liquid nixy resin sag polymer 200F with 1jIt190 per epoxy
, 100 f of an aromatic liquid polyamine curing agent having an active hydrogen equivalent of 1.20, and 100 m of toluene were stirred, and the mixture was placed in a 2 t flask containing 1 t of deionized water in the same manner as in Example 1 at 300 °C. It was added all at once while stirring at r, p, m, but the system did not emulsify at all.

While stirring at the same speed, the mixture was gradually heated to 70° C. over 5 hours, the rotation speed was lowered to 200 r, p, m, and the reaction was further allowed to proceed under the same conditions for 3 hours. The reaction product is a lumpy hardened product containing a cylindrical part formed by fusion of granules with a diameter of about 2 to 3 mm, and no spherical hardened product is obtained. Couldn't use it.

Table 1 shows the evaluation results of the activated carbons obtained in Examples 1 to 3 and commercially available granular (2 to 5+m*φ) activated carbons for comparison.

Table 1 Evaluation results of activated carbon However, the adsorption capacity and the number of coal dust were measured by the following method.

(1) Iodine adsorption capacity, according to J Engineering 5K14744.2.

(2) Adsorption capacity for uric acid: Add 100 µm of 10 dK activated carbon in an aqueous solution of 20 kg/dt, shake for 5 minutes at 37°C and lH2 to adsorb it, and measure the residual uric acid concentration in the supernatant using a liquid chromatograph. Calculated.

(3) m-hirirupin adsorption capacity, total hirirubin value 18.3f
Activated charcoal of 250 ~ was added to 20 d of yellow-stained dog plasma of /eLt, and after shaking at 37° C. and 2 Hz for 3 hours, the residual bilirubin concentration was determined and calculated using a colorimetric method.

(4) Ejected carbon - Disperse the activated carbon in distilled water and fill it into a lath pin. After shaking at 37°C and 2H2 for 48 hours, the activated carbon is separated by F using a 100-mesh wire mesh, and the F solution is distilled. Dilute io*K with water, 0oulter count
Particles of 2 to 20 μmφ were counted by er.

From the results in this table, the activated carbon obtained by the method of the present invention has a fine structure formed because it is made from a robust thermosetting resin, and exhibits a large specific surface area and excellent adsorption ability. it is conceivable that.

In addition, when comparing the number of released coal dust under the harsh conditions of photographing with water for two days and nights in 2H2, even activated carbon, which is the most durable among natural products, has 8,700 particles/dust in the water.
- While the activated carbon of the present invention is made of solid material and has a spherical shape, it is 1/60 to 1/60 of that amount.
It can be seen that only about 200 cases occurred.

Patent applicant: Sumitomo Bakelite Co., Ltd. = 55

Claims (1)

[Claims] After mixing the condensation type or polyaddition type thermosetting resin polymer with a curing agent, curing catalyst, filler, blowing agent, coloring agent, emulsifier, stabilizer, etc., if necessary, emulsify it in water with stirring. Then, the viscosity and particle size are increased by causing a reaction at room temperature or under heating while stirring, resulting in a suspended state.Then, the reaction is continued with continued stirring and maintained in this state, resulting in curing. Polymer resin spheres were heated to 5°C in the absence of oxygen gas.
A method for producing spherical activated carbon, which comprises carbonizing it by heating to 0.0° C. or higher, and activating it by heating it in a stream of steam, carbon dioxide, and/or oxygen/nitrogen mixed gas.