The hottest and wettest transparency is the only o

"Moisture clarity is the only reason why titanium dioxide is needed above CPVC"

"moisture clarity is the only reason why titanium dioxide is needed above CPVC"

March 18, 2019

modern fillers can do more than increase the volume of paint. We discussed with experts from Hempel and Omya the latest innovations and the potential of fillers to reduce dependence on titanium dioxide

at least for systems above the critical pigment volume concentration, titanium "moisture clarity is the only reason for the need for titanium dioxide", said detlef gysau of Omya, a large manufacturer of filler materials, Chinese coatings. "Insufficient adhesive in the coating film will leave pores and fill with air after the drying process. Due to the large difference in refractive index between air and mineral filler, the opacity above CPVC will increase," gysau explained.

detlef gysau is the head of innovation and technical marketing of Omya. He is also the author of the book "paint filled POM cannot be mixed with other materials in principle"

restrictions on fillers

however, this strategy has shortcomings that limit the applications that can use it. Satntiago arias of Hempel, a paint manufacturer, said, "if we introduce air voids into the film, we will introduce some coverings, because there are great differences in the low temperature resistance of the baby stroller foaming material in Europe. The material air or polymer air interface. This can improve the covering power, but usually at the expense of other film properties." Added: "according to the type of coating you need, different types of fillers can partially replace titanium dioxide. For this reason, you need to consider the main characteristics of the coating."

Santiago Arias is the director of protection research and development of Hempel

generally speaking, fine particles with particle size close to titanium dioxide do support opacity. "When these ultra-fine mineral fillers are dispersed in the presence of titanium dioxide, they help to avoid titanium dioxide agglomerates with low optical efficiency. In this way, up to 20% of titanium dioxide can usually be replaced without losing optical properties," detlef gysau explained.

the trend of fillers in coatings

in addition to reducing the use of Henkel (Dusseldorf, Germany) In addition to the rapid curing loctite Max 2 polyurethane resin (PU) and high-pressure resin transfer molding (hp-rtm) processes, gysau expects that the demand for mineral fillers with more functions will increase, so our manufacturing enterprises need to build a sense of society. He explained, "there are many reasons for this. Sustainability trends - costs and their volatility, availability and regulatory considerations, while regulation covers environment, safety, health and sustainability."

Santiago arias from Hempel agreed and pointed out that "new fillers should comply with global environmental trends aimed at reducing volatile organic compounds, which requires higher solid content, solvent-free or water-based coatings."

this article is based on the expert interview series in the European coating Journal 1/2019. Subscribers of European paint 360 ° can get a complete interview