Disclosed herein is a coloring-time controlling layer suitable for use in a temperature-control indicator unit. The coloring-time controlling layer is composed of a film obtained by drying an emulsion of a polymer containing styrene and/or acrylonitrile as constituent unit(s) and interposed between [A] a layer containing microcapsules of an oily substance and [B] another layer containing a substance capable of inducing coloring upon contact with the oily substance. In a preferred embodiment, the coloring-time controlling layer is used for a temperature-control indicator unit comprising microcapsules containing a hydrophobic organic compound having a desired melting point, a methine-type dyestuff precursor and an oxidizing substance.
本文公开了一种适用于温度控制指示装置的着色时间控制层。该着色时间控制层由一层薄膜组成,该薄膜是通过干燥以
苯乙烯和/或
丙烯腈为组成单元的聚合物乳液而获得的,它被夹在[A]一层含有油性物质微胶囊的层和[B]另一层含有与油性物质接触后能引起着色的物质的层之间。在一个优选的实施方案中,着色时间控制层用于温度控制指示器单元,该单元由微胶囊组成,微胶囊含有具有所需熔点的疏
水性有机化合物、
甲烷型
染料前体和氧化物质。