Aniline black having specific sulfur content, and resin composition and water-based and solvent-based dispersions using the aniline black
AssigneeToda Kogyo Corporation
InventorsYusuke Shimohata, Kohei Uehara, Nobuya Shimo, Koso Aoki
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Abstract
The present invention provides aniline black comprising no harmful substances such as chromium and copper in its products and having an excellent blackness and a high resistivity value, as well as provides a black resin composition, a water-based dispersion and a solvent-based dispersion which are colored with the aniline black and have an excellent dispersibility. The aniline black according to the present invention has a sulfur content of 0.2 to 6.0% by weight and comprises primary particles having an average major axis diameter of 0.05 to 0.80 μm.
Claims10
Aniline black having a sulfur content of 0.2 to 6.0% by weight and comprising primary particles having an average major axis diameter of 0.05 to 0.80 μm.
A process for producing aniline black comprising the steps of:
- preparing an acid aqueous solution of an aniline salt which is rendered water-soluble with an acid;
- adding a metal or a metal salt capable of acting as a decomposition catalyst for an oxidizing agent to the acid aqueous solution of the aniline salt to prepare a mixed solution;
- while stirring the mixed solution, adding dropwise the oxidizing agent thereto to subject the aniline salt to oxidation polymerization, thereby producing aniline black;
- and
- then neutralizing the resulting reaction solution with an alkali agent, followed by subjecting the neutralized product to filtration, washing with water and drying,
- in which the acid aqueous solution of the aniline salt comprises a sulfonyl compound represented by the following general formula (I):
- Ar—SO3H (I)
- wherein Ar represents an aryl group which may be substituted with a hydroxyl group or a carboxyl group.
Dependencies are inferred from the claim text.