Titanium dioxide: Characteristics
Rutile or anatase: choosing the right white
What this tab covers The physical and chemical properties that set its grade, price and uses, with the commercial grades and the standards that define them.Buyers choose pigment by crystal form, TiO2 content, surface treatment and particle size. Rutile chloride grades give the best durability and brightness for exterior paint; anatase sulphate grades suit paper, fibres and indoor uses. Surface coatings of alumina, silica or zirconia decide weathering and dispersion.
Properties that matter commercially
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| Refractive index | rutile about 2.7; anatase about 2.55; calcium carbonate about 1.6 | Sets hiding power | CRC Handbook via titanium tile |
| TiO2 content | ISO 591-1: R1 at least 97%, R2 at least 90%, R3 at least 80% | Higher content for premium paints; lower for fillers | ISO 591-1 |
| Particle size | about 0.2-0.3 micron for pigmentary grades; under 0.1 micron for nano grades (indicative) | Optimum light scattering at about half the wavelength of visible light | Indicative |
| Oil absorption and dispersion | grade-specific (indicative) | Affects paint viscosity and processing | Indicative |
Commercial grades
- Chloride rutile for exterior and automotive coatings
- Sulphate rutile for general paint and plastics
- Anatase for paper, fibres and catalysts
- Food, pharma and cosmetic grades
- Nano and ultrafine grades for UV filters