开始加热，酚和甲醛(需有酸或碱促使其反应进行)便产生了像紫胶样的液体，能像清漆一样涂于物体表面。
Initial heating of the phenol and formaldehyde (in the presence of an acid or base to get the reaction going) produced a shellac-like liquid good for coating surfaces like a varnish.
紫胶，虫胶由紫胶虫分泌的沉积于树上的树脂分泌物，用于制造虫胶清漆。
A resinous secretion of the lac insect deposited on trees and used in making shellac.
紫胶，虫胶由紫胶虫分泌的沉积于树上的树脂分泌物，用于制造虫胶清漆。
A resinous secretion of the lac insect deposited on trees and used in making shellac.
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