Reversible thermochromic microcapsule pigment

Abstract

To provide a reversible thermochromic microcapsule pigment that exhibits such reversible thermochromic behavior that the pigment easily turns from a colorless state to a color-developing state when being heated in a living environment temperature range or at or near everyday life temperature, and returns to the colorless state, and also exhibits a high color density when the pigment develops color. This reversible thermochromic microcapsule pigment comprises (a) an electron-donating color-developing organic compound, (b) a hydroxyphenyl acetic acid ester compound represented by general formula (1) and serving as an electron-accepting compound, (c) a compound selected from chain hydrocarbons, alicyclic hydrocarbons, and halogenated hydrocarbons, as a reaction mediator that reversibly causes an electron transfer reaction between the component (a) and the component (b), and (d) a styrene-based compound having a softening point of 5 degC or higher and a mass-average molecular weight of 200-100,000. (In the formula, R represents a straight-chain or branched alkyl group having 12-22 carbon atoms, X, Y, and Z each independently represent hydrogen or a hydroxy group, and two or three of X, Y, and Z are each a hydroxy group).

Description

technical field [0001] The present invention relates to reversible thermochromic microcapsule pigments. More specifically, it relates to a reversible thermochromic microcapsule pigment that develops color from a decolorized state by heating. Background technique [0002] Conventionally, a compound comprising (a) an electron-donating chromogenic organic compound, (b) an electron-accepting compound, and (c) a reaction medium that reversibly causes an electron transfer reaction between components (a) and (b) has been disclosed. In the reversible thermochromic composition, by using hydroxybenzoic acid ester as the component (b), it shows the discoloration behavior of changing from the decolorized state to the color-developed state by heating, and returning to the decolorized state by cooling A reversible thermochromic composition and a microcapsule pigment including the reversible thermochromic composition (for example, refer to Patent Document 1). [0003] Although these reve...

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Problems solved by technology

[0003] Although these reversible thermochromic compositions show a color-developed state by heating, the color-developing temperature is high, and it is difficult to easily develop color at or near the daily temperature.

In addition, even if a reversible thermochromic composition that develops color at or near the daily temperature is obtained, the color density in the color-developed state is low, which is not satisfactory for practical use.

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