No.15 12 Samurai Take the Challenge: Creating a Model Factory with the World’s Highest Eco-Friendliness Rating

Did you know that TOTO has developed and marketed coating materials? TOTO's eco-friendly products, derived from its patented photocatalyst technology Hydrotec, can self-clean using the sunlight and rain. In addition, they feature an air-purification mechanism that has drawn a lot of attention from companies seeking to reduce environmental impact, as well as from countries seeking to reduce air pollution. Homeowners who want to keep their homes clean as long as possible have highly rated the coating material for use on exterior walls. The long path to achieving this breakthrough in photocatalytic coating materials was one of constant trial and error. This Green Story takes us behind the scenes of the development of the Hydrotect Color Coat.

Koji Okubo

Manager, Technical Development Section, Technical Development Department, TOTO Okitsumo Coatings Ltd.

Okubo joined TOTO in 1999. Since joining the launch of TOTO's coating business in 2000, he has focused on developing photocatalytic coating materials.

Chapter 1

A Leap of Imagination and On-Site Verifications Led Us  to a Breakthrough

The quality of a coating material is determined by a combination of ingredients, and the development of a new product requires extensive verification trials. We did this by making 100 samples with slightly different combinations of ingredients and painting each of them on a tiny plate, making painstaking efforts.
The Hydrotect Color Coat has the incredible properties of self-cleaning and air purification.

The development of a new product requires constant, mind-boggling repetition of trial-and-error attempts.

This studio, containing labware and instrumentation for making prototypes, resembles a university laboratory.

These features are attributed TOTO's patented Hydrotect photocatalyst technology. To maximize its attributes, we spent years on trial-and-error efforts and finally launched the ECO-EX onto the Japanese market in 2007. We came up with the idea of developing a transparent coating material with photocatalytic capacity for finishing coats, and we ultimately created a coating with far more functionality and increased performance than conventional coatings. Following a customer request, we were able to achieve sufficient results in experiments on the coating's capacity to remove air pollutants. Customer satisfaction has been very high, and Toyota selected the coating for the exterior walls of its Prius factory.

A stain on a panel with a photocatalytic coating can be easily removed with water.

The transparent coating was difficult to use, because it was hard to see if it was properly painted, so the engineers colored it. ECO-EX becomes transparent when it has dried.

However, there was one problem. Only experienced painters could paint transparent coating materials neatly. At sites where coatings are usually used, the weather can suddenly change and given the precarious position in which they often have to paint, it is unlikely that painters could refer to the TOTO manual for detailed instructions. A product that is hard to use cannot be widely used even if it has superior qualities. This was a huge dilemma for us. We found that the full performance of our coating could not be achieved without applied by an experienced painter. So, we decided to develop a new product that would be easy to apply without referring to a manual.

Fortunately, compared with 10 years ago when we had first conducted a lot of trial-and-error attempts, the raw materials used for photocatalytic products have drastically improved so the photocatalyst effect can be achieved by simply mixing the product with paint, just like general coating materials. The last challenge for us was to improve usability. We conducted on-site verifications with experienced painters. We asked them to use the product without telling them that it was a prototype, and we did not explain how to use it. If they asked, "Is it a coating? It doesn't seem like anything special," we had succeeded. But if they said, "There's something strange about this," we knew we had to make it again. To improve usability was not easy at all, because it could be evaluated by humans.

Usability for a painter depends on a sticky texture. It was not easy to discover the proper stickiness.

A sample is made by painting a prototype on a plate and drying it overnight. More than hundreds of samples are made for a product.

The white color of plates coated with photocatalytic material gradually becomes far brighter than plates without it.

Through the repetition of these on-site verifications, we finally completed ECO-HG, a product we could launch in May in 2014 with confidence. We have received positive feedback from users, and the price is reasonable. We hope more people will hear about this innovative photocatalytic coating and begin using Hydrotect products around the world, especially in countries with air pollution challenges.

- Hydrotect Website

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