| 摘要 |
A resin-coated sand comprising: (a) particles of sand coated with from about 1% to about 8%, by weight of the sand, of a novolak resin consisting essentially of about 50% to about 98% of a phenol-formaldehyde novolak resin and about 2% to about 50% of a catechol-formaldehyde novolak resin; and, (b) a curing agent. The sands are especially useful for forming foundry cores and molds.
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