| 摘要 |
<p>1516062 Sulphonated lignin-containing materials G A SERLACHIUS OY 19 Jan 1977 [30 Jan 1976] 2159/77 Heading C3R Products which may be used as dispersing agents, extenders for glues and as additives to drilling muds, are obtained by sulphonating lignin-containing material and then heating the sulphonated material containing less than 15% by weight of water at a pH of less than 7 (measured in 3% aqueous solution) and at a temperature of 80‹ to 225‹ C. Examples are given in which sulphite spent liquors are reacted with sulphuric acid, calcium sulphate removed, the clear solutions (having acid pH values) are spray dried materials are heated.</p> |
