Artist Yves Klein was so happy with his discovery of a new ultra blue that he gave it his name and registered it as an invention with the French authorities two years before his death in 1960.
But scientists at Oregon State University may put International Klein Blue in the shade with the accidental discovery of a new pigment that is going on sale.
It’s a vivid “near perfect” blue they believe solves the problems of safety, toxicity and durability that have dogged the search for the best blue going back to ancient times.
The unique heat-reflecting properties of “YInMn Blue” (named for its chemical components: Yrttrium, Indium, Manganese) also make it a candidate for keeping future cars and buildings cool, its discoverers say.
In 2009 chemist Mas Subramanian and his team were exploring new materials for use in electronics when they mixed black manganese oxide with other chemicals and heated them to nearly 2000 degrees Fahrenheit.
“It was serendipity, actually; a happy, accidental discovery,” Professor Subramanian said.
“Our work had nothing to do with looking for a pigment.
“Then one day a graduate student who is working in the project was taking samples out of a very hot furnace while I was walking by and it was blue, a very beautiful blue”, Professor Subramanian said.
“I realised immediately that something amazing had happened”.
They’d found a new pigment formed by a unique crystal structure that allows the manganese ions to absorb red and green wavelengths of light while reflecting only blue, the university said in a press release. The “cool blue” compound has an infrared reflectivity of about 40 per cent, much higher than other blue pigments.
“Our blue pigment is unique because it is durable with a hue similar to ultramarine blue, (Lapis Lazuli) but also shows heat reflectance,” the professor said in an email.
“So it can be used as ‘cool’ pigment which can keep buildings and cars cool. This is not possible with ultramarine blue or Co-blue pigments.”
Professor Subramanian said blue-coloured compounds that do not fade are difficult to make. The last durable blue pigment discovered was Cobalt blue (Co-blue) in 1802.
But in accelerated testing to check long-term durability of coatings and paint containing the pigment, YInMn Blue stood up well to UV radiation, carbon dioxide, water, acid rain, oil and other assailants, Professor Subramanian said. Even better, none of its ingredients are toxic, he said.
The university has made an exclusive licensing agreement with a commercial company. The pigment will be used in a range of coatings and plastics.
The unique quality claimed for International Klein Blue, developed by the artist in collaboration with a Parisian paint supplier, was not the ultramarine pigment but its suspension in a polyvinyl acetate synthetic resin which allows it retain a high intensity of colour without fading.
The search for compounds that can be used to paint things blue goes back thousands of years.
From the third millennium BC, the Egyptians made a blue from a mixture of silica, lime, copper and alkali; it is considered to be the first synthetic compound.
But many blue pigments had problems of durability and safety. Cobalt blue can be carcinogenic and Prussian blue can release cyanide.