Due to the number of manufacturers, multitude of manufacturing methods, types, brands and application areas, classification of titanium dioxide pigments, commonly named titanium white, is not an easy case and may be carried out with taking several criteria into consideration.
Classification:
- production technology – into sulphate and chloride ones,
- crystallographic type – into anatase (A) and rutile (R) ones,
- type of surface treatment – into not-treated (A1, R1), medium-treated (A2, R2) and deeply treated (R3).
Classification of pigments is given by the international standards (EN ISO 591-1:2002) and the national standards (e.g. ASTM D476-00, DIN 55912-2:1999 or GOST 9808-84). The most widespread separation is the classification specified by the ISO 591-1:2000, based on division of pigments depending on their crystallographic structures and titanium dioxide content.
Classification of titanium dioxide pigments according to EN ISO 591-1:2000.
| Type | Grade | Content of TiO2 [% m/m]min.) |
Water souble substances [% m/m]max. |
Volatile matter*) [% m/m]max. |
| Anatase
(type A) |
A1 | 98 | 0,6 | 0,5 |
| A2 | 92 | 0,5 | 0,8 | |
| Rutyle
(type R) |
R1 | 97 | 0,6 | 0,5 |
| R2 | 90 | 0,5 | 1,5 | |
| R3 | 80 | 0,7 | 2,5 |
*) At the temperature of 105°C, after 24h conditioning at the temperature of 23±2°C
and relative air humidity 50±5%.