| 摘要 |
<p>The process of making a wet or dry dispersion containing anthraquinone suitable for use in the alkaline digestion of wood comprising cyclizing ortho-benzoylbenzoic acid at a temperature of about 150 DEG to 180 DEG C. and at an absolute pressure between about 5 and 40 millibars in the presence of between about 0.05 to 2 parts by weight of sulfuric acid, having a concentration of at least about 95%, per part by weight of ortho-benzoylbenzoic acid to form a reaction mixture containing anthraquinone, bringing the reaction mixture to a pH of at least about 7 by addition thereto at a temperature between about ambient temperature and 100 DEG C. of an aqueous solution of sodium hydroxide or potassium hydroxide containing between about 10% to 40% hydroxide by weight, and then forming a dispersion thereof and using such dispersion in the alkaline digestion of wood.</p> |
