Reversibly thermochromic systems based on pH-sensitive spirolactone-derived functional dyes
Composites formulated from pH-sensitive colour formers mixed with fatty acid co-solvents and acidic developers have been prepared and their thermochromic properties investigated. Possible explanations for the thermochromic effect have been considered and evidence is presented in support of a mechanism based on phase changes occurring within the compositions during heating and cooling. British Crown Copyright 1998/MOD. Published with the permission of the Controller of Her Britannic Majesty's Stationery Office.
Burkinshaw, Stephen M.,Griffiths, John,Towns, Andrew D.