摘要 |
A process for making sand cores or molds is disclosed; the completed cores and molds as well as a binder for holding the sand particles together. The resin binder is used in the process and in the finished product comprising lignin dissolved in a suitable solvent reacted on or cured with an isocyanate material. Curing can be accomplished by the use of an amine along with a catalyst if desired. A polyether polyol may be integrated with the lignin to vary the physical characteristics of the binder.
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