Investigation of the effect of hollow core polymer pigments on the drying rate of the traffic paints

Abstract

One approach to reducing the cost of roadway markings made with paints is to replace part or all part of titanium dioxide (TiO2) as opacifier with an opacifier relies on voids or hollow spaces, such as hollow core pigments. This paper introduces fast-drying aqueous compositions comprising an aqueous dispersion of these hollow core polymer particles in different media and different particle size.

These kind of pigments play the role of both binder and opacifier pigments which can be made of a first polymer having a glass transition temperature (Tg) of 50 ^oC or more being encapsulated by one or more second polymer having a Tg of -30 ^oC or more chosen from an anionically stabilized emulsion polymer, a poly amine functional polymer, a hydrophobic polyamine functional emulsion polymer having pendant strong cationic groups and an emulsion polymer having pendant weak acid groups. Butyl acrylate (BA), divinyl benzene (DVB), methyl methacrylate (MMA), methacrylic acid (MAA) can be used as second polymer. The low Tg of second polymer on the hollow core polymers improve the fast-drying property and film formation of final paint. Fast-drying aqueous compositions may be one component or two component composition. One component composition has one or more volatile aqueous base, one or more polyfunctional amine and one hollow core polymer pigment. Two component compositions comprise one or more aqueous hollow core binder and an absorber component. The best particle size of these hollow core binder particles and pH of volatile aqueous compositions have been reported in range of 300 to 470 nm and 7.5 or more, respectively.