| 摘要 |
516,609. Phenol-aldehyde condensation products. I.G. FARBENINDUSTRIE AKT.-GES. July 1, 1938, No. 19555. Convention date, July 21, 1937. [Class 2 (iii)] Cation-exchanging resinous gels consisting of phenol-aldehyde condensates containing sulphonic groups are after-treated with sulphuric, phosphoric or hydrochloric acid at a raised temperature to diminish their capacity for swelling. In examples (1) gels prepared from phenol and sodium sulphite in the presence of formaldehyde are treated with hydrochloric and sulphuric acid, (3) a gel prepared from resorcinol sodium sulphite and formaldehyde is treated with hydrochloric acid. The Specification as open to inspection under Sect. 91 refers to the use of inorganic acids in general. This subject-matter does not appear in the Specification as accepted. |
