TiO2 for Architectural Coatings
Interior emulsion + exterior facade paints — the largest single TiO2 application by volume.
Architectural coatings — interior emulsion paints, exterior facade systems, and decorative finishes — represent the world's largest single application for titanium dioxide by volume. Roughly 30–35% of global TiO2 demand goes into this segment. The matte and flat finish portion alone accounts for the majority of residential and commercial repaint activity.
For interior emulsion paints, the key TiO2 performance levers are: (1) hiding power per kg, (2) tinting strength in colored systems, (3) whiteness retention over storage, and (4) anti-settling behavior in low-shear cans. For exterior facade systems, additional requirements come into play: (5) UV durability — measured as gloss retention and chalking resistance over 5–10 years of outdoor exposure, and (6) self-cleaning / dirt-pickup-resistance.
SEMITI's architectural lineup is designed around the buyer's choice of process and gloss level: - SEMITI 706W — premium chloride rutile optimized for waterborne emulsion paints, hydrophilic surface treatment, minimum TiO2 demand (Δ-WI < 2 at standard 15% PVC formulations) - SEMITI 902 — universal chloride rutile, the reference grade for most matte to semi-gloss systems - SEMITI 298 — sulfate-process rutile for cost-optimized interior paints, 25% cheaper than chloride equivalents - SEMITI SL70 — pre-dispersed 70% slurry for high-throughput paint plants, eliminates powder handling + dispersion step
Recommended SEMITI grades
Optimized for waterborne emulsion paints — minimum TiO2 demand, excellent anti-settling.
Universal coatings-grade rutile — the global reference for waterborne and solventborne paints.
Cost-optimized sulfate-process rutile — 25% cheaper than chloride for non-critical applications.
Pre-dispersed 70% solids slurry — drop-in for waterborne paints and paper coating, eliminates dust + dispersion step.
Performance requirements
| Hiding power | Contrast ratio ≥ 96% at 250 g/m² wet film, white over black contrast card (ISO 6504-3) |
| Tinting strength | ≥ 1850 Reynolds units — sets the floor for colorant economy |
| Whiteness impact (Δ-WI) | ≤ 2 units after 6-month warehouse storage at 35°C / 60% RH |
| Sedimentation | No hard pack after 3-month static storage; full re-dispersion in <2 min standard mechanical stir |
| Scrub resistance | ASTM D2486 ≥ 200 cycles for matte interior; ≥ 1000 cycles for semi-gloss |
| QUV exposure (exterior only) | Gloss retention ≥ 70% at 1000 hr QUV-A (ASTM G154 Cycle 1) |
Dosage guidance
Dispersion / processing notes
For powder grades, standard high-speed dispersion (Cowles disk, 15–25 m/s tip speed) in the pigment grind phase achieves Hegman 6+ in 20–30 minutes. SEMITI 706W and SEMITI 902 are optimized for waterborne grind — pre-wet with water and dispersant (sodium polyacrylate or APE-free dispersant) before adding pigment to avoid lumping. For SEMITI SL70 slurry, pre-stir in tank for 5 minutes before letdown, no grinding required.
Formulation tips
- →Match TiO2 surface treatment to binder system — hydrophilic-coated TiO2 (SEMITI 706W) for waterborne acrylic; standard alumina (SEMITI 902, 298) for solventborne alkyd or styrene-acrylic
- →In high-PVC matte paints, extender choice matters more than TiO2 choice — calcined kaolin and surface-treated CaCO3 contribute 30–40% of hiding power; TiO2 contributes the rest
- →Anti-settling: add 0.3–0.5% fumed silica or 0.2% rheology modifier (HEUR or HASE) to prevent hard packing — especially important in slow-moving inventory paints
- →For brilliant white claims (CIE WI > 80), use chloride rutile and avoid mixing process types within the same formulation — sulfate adds a slight yellow undertone
- →Test against the current TiO2 spec before bulk substitution — small batch trial in production-scale mixer, not just lab can
Common pitfalls
Failure modes we've seen in customer trials — worth checking before scale-up.
- ×Substituting sulfate for chloride in premium semi-gloss often visibly reduces gloss at 60° (1–3 unit drop) — only acceptable for matte / flat
- ×Mixing TiO2 from two surface-treatment families in the same batch can cause flocculation in the can during storage — pick one supplier per batch
- ×Surface-treated rutile in waterborne systems can flocculate if pH drops below 7 — check buffering capacity of the formulation
- ×Outdoor service > 5 years requires durable rutile (SEMITI 826D) — using interior-grade rutile causes premature chalking visible within 18 months
Common questions
Which SEMITI grade is the right starting point for waterborne interior?+
Can I reduce TiO2 loading by 20% and add more extender?+
What's the difference for exterior vs interior?+
Does TiO2 affect VOC?+
Pair with matting agent for architectural 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 architectural coatings?
Send us your reference grade, formulation type, or competitor TDS. We'll respond with the SEMITI match + sample within 48 hours.