Thermochromic coatings


A thermochromic coating (from Greek thermos temperature and color chromos) is, by definition, made up of a pigment / dye whose optical properties change as a function of temperature. Today there are 3 major families: organic thermochromic materials such as liquid crystals or ‘leuco dyes’, hybrids and inorganics. The physical mechanisms at the origin of the color change are an electron or proton transfer, a change of coordination site, an intramolecular cyclization, ... Each of these families presents, according to the industrial specification concerned, advantages and disadvantages.

The main pitfalls too often encountered are the sensitivity to ultraviolet, the low coloring power, the limited thermal resistance (200-240 ° C), the loss of properties during the formulation and / or the industrial process, the toxicity of certain elements components …

And yet, the opportunities are real if the constituents are well selected. Depending on the selected ingredients, the thermochromic property becomes reversible or irreversible, the color change threshold is adjustable over a wide temperature range (from -200 ° C to + 1000 ° C) and the modification of the optical properties can be generated in the Ultra-Violet, Visible and / or Infrared region.

Competitive and economic context:

Several uses of thermochromic coatings nowadays mark our daily life, like the inks of FRIXION® pens, which fade under the heating of an eraser, colored indicators encountered for example on batteries, beers and / or play articles.

But the greatest opportunities concern sustainable industrial uses, characterized by good UV resistance. The strategic analysis Color-Shifting Materials Market Opportunities – 2015/2022 reports several Mass Markets in the fields of construction, automotive, cosmetics, luxury, … and identifies OliKrom as a major player at the international level.

link to the strategic analysis: