摘要 |
Modified phenol-formaldehyde resins, and processes for their preparation, are described wherein board or paper pulping process waste liquor is used as the modifier. The resins may contain, based on solids contents of both resin and waste liquor, from 1:10 to 10:1 parts by weight. These resins are cheaper than conventional resins and also use the waste-liquor without any purification step. |