TiO2 for Automotive Coatings
OEM and refinish topcoats with acid-rain resistance, clearcoat compatibility, and metallic effect support.
Automotive coatings are among the most demanding TiO2 applications. The finished paint must perform across a daunting list of requirements: 10+ year color stability outdoors, acid-rain etch resistance, stone-chip resistance, clearcoat layer cohesion, tight color tolerance for body-shop production matching, fast cure times to meet line speed, and compatibility with both 1K and 2K acrylic-melamine and acrylic-PU chemistries.
For OEM solid white, SEMITI 880 (matched to Tronox CR-880) is the recommended grade — engineered specifically for automotive OEM service. For automotive refinish and aftermarket coatings, SEMITI 706 is acceptable with slightly less stringent automotive testing requirements.
Recommended SEMITI grades
Performance requirements
| Acid spot etch resistance (ISO 21227) | No visible mark after 50 μL H2SO4 24hr |
| ΔE (production batch tolerance) | < 0.5 vs OEM reference |
| Stone chip (ASTM D3170) | Rating 8+ at -20°C |
| QUV gloss retention | > 90% at 1500 hr QUV-A |
| Florida exposure (5 yr) | ΔE < 1.5, no chalking |
Dosage guidance
Dispersion / processing notes
Automotive paint is dispersed in modern bead mills (high-energy, narrow PSD output) typically to Hegman 8+. Pre-mix TiO2 with binder + dispersant + solvent without grinding to test wet-out; if Δ-viscosity is high, add 0.3–0.5% more dispersant. Final mill time 60–120 min to achieve target PSD.
Formulation tips
- →Use SEMITI 880 for OEM solid white; SEMITI 706 for refinish and aftermarket
- →For metallic effects, pre-mix mica/aluminum flake with SEMITI 880 at 1:5 ratio for uniform distribution
- →Two-component (2K) acrylic-PU is the standard chemistry — verify cure conditions match TiO2 surface treatment compatibility
- →Color-match production runs are batch-to-batch tighter with SEMITI 880 than 706 (Δb* spec is tighter)
Common pitfalls
Failure modes we've seen in customer trials — worth checking before scale-up.
- ×Using sulfate rutile in automotive — acid spot etch will fail
- ×Mixing TiO2 brands within a single production run — Δb* tolerance is exceeded
- ×Using interior-grade rutile (SEMITI 902) in OEM solid white — chalking will appear at 2-year mark
Common questions
How does TiO2 affect automotive metallic effect coatings?+
Does SEMITI 880 meet IMDS / GADSL requirements?+
Pair with matting agent for automotive coatings
TiO2 provides hiding power; silica matting agent provides gloss control. Both products are typically required in the same matte/eggshell formulation. Our sister brand GMATT (matting-agents.com) supplies the matched silica matting agent.
Need help picking a grade for automotive coatings?
Send us your reference grade, formulation type, or competitor TDS. We'll respond with the SEMITI match + sample within 48 hours.