| 摘要 |
PURPOSE:The titled particles which can be mass-produced uniformly by mixing a precondensate of a novolak-type phenolic resin with a decomposable foaming agent and a curing agent to form a composition, which is partially foamed and hardened. CONSTITUTION:Foam particles of a composition which is partially foamed and hardened, comprising a precondensate of a novolak-type phenolic resin and required amounts of a decomposable foaming agent and a curing agent. Various other additives such as a filler, e.g. clay, can be added in small amounts to the composition. The total amount of these additives is preferably not more than 50pts.wt. based on 100pts.wt. resin. Before partially foamed and hardened, the aforementioned composition is preferably granulated in general. The granulation can be effected, for instance, by melting the precondensate of a novolak-type phenolic resin at 60-90 deg.C, into which required amounts of a foaming agent and a curing agent are added, a filler being added if necessary, followed by solidifying thereof to be ground to an appropriate size.
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