Study on preparation of fast curing novolaks for the shell process

To save energy and raise molding and coremaking productivity, the synthetic procedure of novolaks for the shell process was investigated. The study indicated that it was difficult to obtain fast curing novolaks under strongly acidic conditions alone. A novel synthetic procedure was proposed for prep...

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Bibliographic Details
Published in:China foundry 2004-11, Vol.1 (2), p.106-111
Main Authors: Li, Rongqi, Li, Yuancai, Zhang, Haoran, Wang, Wenqing, Wang, Xinji
Format: Article
Language:English
Subjects:
complex catalysis
fast curing novolaks
orthogonal design
shell process
Online Access:Get full text
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Summary:To save energy and raise molding and coremaking productivity, the synthetic procedure of novolaks for the shell process was investigated. The study indicated that it was difficult to obtain fast curing novolaks under strongly acidic conditions alone. A novel synthetic procedure was proposed for preparing novolaks in a two-step manner, a divalent metal salt catalyzed novolak preparation followed by a strong acid catalyzed novolak preparation. The optimum conditions for the two-step procedure were determined by orthogonal experiment design. The results showed that it was easy to prepare fast curing novolaks with cure time in the range of 20 s to 30 s and softening point in the range of 80 DGC to 90 DGC under complex catalysis conditions.
ISSN:1672-6421