JPH10236876A - Method for producing carbonaceous powder slurry - Google Patents

Abstract

(57) [Abstract] [Objective] A slurry of a carbonaceous powder suitable for producing cast moldings by improving the dispersibility of carbonaceous powder in water under conditions of higher concentration and lower viscosity with a small amount of a dispersant. It is an object of the present invention to provide an aqueous treatment method of a carbonaceous powder for producing a carbonaceous powder. [Constitution] Use one or more of condensed naphthalenesulfonic acid ammonium salt, styrene acrylic acid copolymer, and styrene maleic acid copolymer as a polymer resin dispersant for carbonaceous powder or an organic substance. It is characterized by doing. According to the aqueous treatment method for carbonaceous powder of the present invention, a low-viscosity, high-concentration carbonaceous slurry can be realized. By using this carbonaceous slurry, it has become possible to cast a carbon material, which has been difficult in the past.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an aqueous treatment method for carbonaceous powder. More specifically, the present invention relates to an aqueous treatment method of carbonaceous powder necessary for obtaining a carbonaceous slurry for casting in producing a carbon material.

[0002]

2. Description of the Related Art Casting is considered to be a very effective means to obtain a carbon material molded body having a complicated shape. In particular, it is an industrially extremely useful method because it can mold a product having a shape that cannot be produced by the pressure molding method or the extrusion molding method.

[0003] Slurries suitable for casting are those having the highest solids content and the highest fluidity. In other words, a low-viscosity slurry with a necessary minimum water content is required. If the amount of the dispersing agent used to obtain the slurry is too large, the slurry aggregates or hinders the fired product, so that it must be minimized. Currently, casting is widely performed in the field of ceramics. Slurries for casting ceramics generally have a water content of 10
It is adjusted to 30% by weight and the viscosity to 500 cp or less.

However, in the case of dispersing carbonaceous powder in water, there has been no example of achieving the above-mentioned water content and viscosity, and a carbonaceous powder slurry suitable for casting was not obtained. For example, as a use for dispersing carbonaceous powder in water, there is a particle size analysis of pigments and raw materials in which carbon black is dispersed in water, and an aqueous treatment has already been performed with a dispersant such as ammonium polycarboxylate or sodium linoleate. However, in this case, a slurry suitable for casting was not obtained because of a large amount of the dispersant or a large amount of water. The reason why the carbonaceous powder does not disperse in the aqueous system is considered to be the fact that the carbonaceous powder is hydrophobic and porous. However, it is impossible to treat the slurry suitable for casting by the conventional aqueous treatment method. Was.

[0005]

SUMMARY OF THE INVENTION Based on the above presumption, the present invention is to improve the dispersibility of carbonaceous powder in water under a condition of higher concentration and lower viscosity with a small amount of dispersant, and to produce a cast molding. It is an object of the present invention to provide an aqueous treatment method for a carbonaceous powder for producing a slurry of a carbonaceous powder suitable for the method.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, it has been found that adding a specific amount of one or more polymer dispersants gives a good result. Were found, and the present invention was completed. That is, in producing an aqueous slurry of carbonaceous powder, 1 part by weight of condensed ammonium naphthalenesulfonate is used as a dispersant per 100 parts by weight of carbonaceous powder.
A method for producing a carbonaceous powder slurry, comprising adding 0 to 3 parts by weight of a styrene acrylic acid copolymer and / or 0 to 3 parts by weight of a styrene maleic acid copolymer. It is.

Hereinafter, the present invention will be described in more detail. In the present invention, condensed ammonium naphthalenesulfonate, a styrene acrylic acid copolymer, and a styrene maleic acid copolymer are used in combination or alone as a dispersant. Among these, the ammonium salt of condensed naphthalene sulfonic acid, if it is a condensed naphthalene sulfonic acid salt, shows an excellent dispersibility for ammonium salts and sodium salts, and all other salts. Is not preferable because impurities remain. In the case of an ammonium salt, it is preferable that it contains few impurities because it is almost volatilized in a temperature range where carbonization occurs (800 ° C. or higher). The addition amount of these naphthalene sulfonate dispersants is preferably 1 to 5 parts by weight based on 100 parts by weight of the carbonaceous powder. If it is out of this range, the viscosity of the slurry becomes high, so that casting cannot be performed.

On the other hand, the styrene / maleic acid copolymer has a styrene / acrylic acid copolymerization ratio of 1 or more,
Those having a weight average molecular weight of 5,000 to 15,000 are preferably used. The amount of addition of these copolymers was 1
0 to 3 parts by weight per 100 parts by weight is preferred. If the amount is more than this range, foaming becomes severe, so that a dense cast molded product cannot be obtained.

The styrene-maleic acid copolymer preferably has a copolymerization ratio of styrene-maleic anhydride of 1 to 3 and a weight average molecular weight of 1500 to 3000.
Those obtained by esterifying a part or all of maleic anhydride in the copolymer, and furthermore, sodium or ammonium salts of the esterified maleic acid are also preferable. However, when sintering of the cast molded body is considered as described above, the ammonium salt is more preferable. The addition amount of these copolymers is preferably 0 to 3 parts by weight based on 100 parts by weight of the carbonaceous powder. If the amount is more than this range, the viscosity of the slurry increases, and a slurry suitable for casting cannot be obtained.

[0010]

According to the method of the present invention for treating an aqueous carbonaceous powder,
It has become possible to produce a carbonaceous slurry having a higher concentration and a lower viscosity with a smaller amount of dispersant than before. Also, by using this carbonaceous slurry, casting of a carbon material has become possible.

[0011]

Embodiments of the present invention will be described below.

[0012]

Example 1 A 5000 cc polyethylene wide-mouthed bottle was used as a ball mill pot, and 2,000 g of distilled water was added thereto, and zirconia balls (φ = 5 mm) were used as cobblestones for 2500.
g, 100 g of a 40% aqueous solution of a condensed ammonium naphthalenesulfonate dispersant (manufactured by SAN NOPCO LIMITED), and 100 g of a 34% aqueous solution of a styrene-acrylic acid copolymer dispersant (manufactured by Johnson Corporation) 12 g of Joncryl 62) was well mixed in a ball mill. Thereafter, petroleum-based coke (trade name: GL500, manufactured by Chuetsu Graphite Co., Ltd., particle size: 500 mesh) was added to 3260 g while mixing with a ball mill. The ball mill mixing time was 144 hours.
The obtained carbon powder slurry had a water content of 37.3% by weight, a viscosity of 480 cp, and a pH of 4.0 (10.8 ° C.).

[0013]

Example 2 66 g of condensed naphthalenesulfonic acid ammonium salt dispersant (Rome PWA-40) and 14 parts of styrene acrylic acid copolymer dispersant (Johncryl 62) were used.
g, 50 parts of self-sintering mesophase carbon (trade name: mesocarbon microbeads manufactured by Osaka Gas Chemical Co., Ltd.)
A slurry was prepared in the same manner as in Example 1 except that the amount was set to 00 g. The slurry of the obtained mesophase carbon powder had a water content of 28.3% by weight, a viscosity of 320 cp, and a pH of 8.2.
(10.8 ° C.).

[0014]

Example 3 44 g of condensed ammonium naphthalenesulfonate dispersant (Roma PWA-40) and 460 of pitch powder (trade name CIKU, manufactured by Osaka Gas Chemical Co., Ltd.)
A slurry was prepared in the same manner as in Example 1 except that the amount was 0 g. The resulting pitch powder slurry had a water content of 30.3% by weight, a viscosity of 380 cp, and a pH of 8.3 (10.8 ° C.).

[0015]

Example 4 Example 1 was repeated except that the styrene-acrylic acid copolymer dispersant was replaced by 12 g of a styrene-maleic anhydride copolymer dispersant (trade name: SMA resin, manufactured by Arco Chemical Asia Pacific Limited). A slurry was prepared in the same manner as described above. The slurry of the obtained carbon powder had a water content of 28.0% by weight, a viscosity of 300 cp, and a pH of 5.2.
(10.8 ° C.).

Comparative Example 1 A slurry was prepared in exactly the same manner as in Example 1 except that a polycarboxylic acid ammonium salt dispersant was added as a dispersant in an amount of 0 to 10% by weight based on 100 parts by weight of the carbonaceous powder. The viscosity of the obtained slurry exceeded 1000 cp, and a slurry suitable for cast molding could not be obtained.

Comparative Example 2 A slurry was prepared in the same manner as in Example 1 except that sodium linoleate was added as a dispersant in an amount of 0 to 10% by weight based on 100 parts by weight of the carbonaceous powder. The viscosity of the obtained slurry far exceeded 1000 cp, and a slurry suitable for cast molding could not be obtained.

[0018]

As described above, according to the aqueous treatment method of carbonaceous powder of the present invention, a low-viscosity, high-concentration carbonaceous slurry can be realized. By using this carbonaceous slurry, it has become possible to cast a carbon material, which has been difficult in the past.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C01B 31/02 101 C01B 31/02 101Z C04B 35/622 C04B 35/00 D

Claims (2)

[Claims] 1. One or two of condensed ammonium naphthalenesulfonate, styrene acrylic acid copolymer and styrene maleic acid copolymer as a polymer resin dispersant for a carbonaceous powder or an organic substance. A method for producing a carbonaceous powder slurry, comprising using the above. 2. A method for producing a carbonaceous powder slurry for casting, wherein the slurry of claim 1 is adjusted to a water content of 20 to 40% by weight and a viscosity of 500 cp or less.