| 摘要 |
The sugar solution is contacted with an acid activated spongy cation exchange resin i.e. a non-proliferous synthetic water-insoluble resin, the matrix of which is formed of a cross linked copolymer of heterogeneous structure obtained from vinyl aromatic monomers. The resin may contain carboxylic or sulphonic acid ion exchanging groups and after exhaustion may be regenerated by a solution of an alkaline earth metal salt or hydroxide and thereafter with an aqueous solution of a mineral acid. The solution may also be contacted with a spongy or homogeneous anion exchange resin having basic nitrogen-containing groups such as neutralized quaternary ammonium groups. Either resin may be used first, or both may be used simultaneously. Suitable spongy cation exchangers may be produced, as described in Specification 894,391, by sulphonating a copolymer of styrene and divinyl benzene, the copolymerization being effected in aqueous suspension in the presence of white spirit or normal heptane. A carboxylic cation exchanger may be produced by saponifying a spongy copolymer of methyl acrylate and divinyl benzene in the presence of normal octane. The preparation of suitable anion exchange resins is also described. Specifications 654,706, 679,850, 679,851, 679,852, 700,470, 779,994, 867,449, 885,719, 885,720, 900,037 and U.S.A. Specifications 2,591,573, 2,629,710 and 2,642,417 also are referred to. |
