TiO2 for Plastic Masterbatch
White masterbatch concentrates for PE, PP, ABS, PS film and injection molding — typically 50–70% TiO2 loading.
Plastic masterbatch is the second-largest TiO2 application after architectural coatings, accounting for roughly 25% of global demand. Compounders produce concentrated "white masterbatch" — typically 50–70% TiO2 in a polyolefin carrier (PE wax, PE base, EVA, or compatible polymer) — which is then let down to 1–5% in the final plastic part.
The performance profile demanded of masterbatch-grade TiO2 differs sharply from coatings-grade TiO2. Three properties dominate:
1. Thermal stability — extrusion temperatures range from 180–230°C for LDPE film up to 280–300°C for engineering plastics. The TiO2 surface treatment must survive this without yellowing or evolving moisture that creates surface defects.
2. Extrusion behavior — high-loading masterbatch (60–70%) puts enormous demand on dispersion. Poor dispersion shows up as "fish eyes," nozzle deposits, and screen blinding. Surface treatment must wet quickly into the carrier polymer at melt temperature.
3. Compatibility with downstream additives — masterbatch typically goes into film with slip agents (erucamide, oleamide), antiblocks (talc, silica), antioxidants (Irganox 1010), UV stabilizers (HALS, UV absorbers). The TiO2 surface treatment must not interfere with these — particularly important is no amine-blocking behavior that would degrade HALS efficiency.
SEMITI's masterbatch lineup spans the performance/cost range: - SEMITI 960 — chloride rutile with amine-compatible surface treatment, thermal stability to 300°C (engineering plastics: ABS, PA, PC blends) - SEMITI 996 — universal grade, thermal stability to 280°C (PE, PP, PVC — covers 80% of commodity masterbatch) - SEMITI 2310 — direct alternative to Kronos 2310, universal plastics grade - SEMITI 2190 — premium grade for outdoor / weatherable applications (PVC siding, agricultural film)
Recommended SEMITI grades
Our flagship chloride-process rutile — high tinting strength and broad compatibility for coatings, plastics, and inks.
High thermal stability for engineering plastics — extrusion to 300°C without yellowing.
Universal plastics rutile — direct alternative to Kronos 2310 for PVC, PE, PP, ABS.
Premium plastics rutile for high-performance compounds — engineering plastics + outdoor PVC.
Performance requirements
| Thermal stability (yellowing) | Δb* ≤ 1.5 after 5 min at 280°C (commodity); ≤ 2.0 at 300°C (engineering) |
| Volatiles at 105°C | ≤ 0.30% — higher values cause surface defects in film extrusion |
| Loss on ignition (105–800°C) | ≤ 0.50% |
| Dispersion (fish eye) | ≤ 5 visible defects per 100 cm² in 50 μm PE blown film at 50% loading |
| Screen pack life | ≥ 2 hr at 70% loading, 25 kg/hr, 90 mesh screen |
| Compatibility with HALS | No measurable HALS degradation in 1000 hr QUV at 1% HALS + 2% TiO2 in LLDPE film |
Dosage guidance
Dispersion / processing notes
Twin-screw extruder is standard — typical setup: L/D 36–44, kneading blocks at zones 3–5, vacuum venting at zones 6–7 to remove residual moisture. For 60%+ loading, add a side feeder at zone 4 to introduce TiO2 separately from the carrier. Screw speed 300–500 rpm. Output temperature should not exceed the TiO2 surface treatment's stability limit (check spec — usually 230–250°C for commodity grades, 280°C+ for premium). For final-product extrusion of films, a 60-mesh + 120-mesh + 200-mesh screen pack catches any oversize agglomerates from the masterbatch.
Formulation tips
- →Pair TiO2 with 1–3% calcium stearate or PE wax as primary dispersant — wets the pigment surface, lowers compound viscosity
- →For engineering plastics (ABS, PC, PA), use amine-treated grades (SEMITI 960) — avoids HALS antagonism
- →Pre-dry TiO2 to <0.2% moisture before high-load (>60%) compounding — surface moisture causes splay in injection molding
- →For outdoor / weatherable masterbatch, layer in 0.3–0.5% HALS + 0.2% UV absorber on top of the TiO2 to extend service life 3–5x
- →Test masterbatch by extruding film at 100–150 g/m² and counting visible defects under transmitted light — better than viscosity-based dispersion tests
Common pitfalls
Failure modes we've seen in customer trials — worth checking before scale-up.
- ×Using coating-grade TiO2 (SEMITI 902, designed for solvent/water) in masterbatch — the surface treatment moisture (1–2%) creates splay defects in injection molding
- ×Mixing chloride + sulfate TiO2 in the same masterbatch — different surface chemistries cause inconsistent dispersion, fish-eye defects
- ×Skipping the vacuum vent on the extruder when running >60% loading — residual moisture in the TiO2 surface treatment causes voids in the strand
- ×Overheating engineering plastics MB (>320°C) — even premium TiO2 grades yellow at this temperature, and the carrier polymer degrades
- ×Forgetting that nano-TiO2 (SEMITI NANO-30) is for personal care, NOT plastics — nano TiO2 in plastics causes photocatalytic polymer degradation
Common questions
What's the highest TiO2 loading I can run in a 50:1 L/D twin-screw?+
Can I use SEMITI 996 in PE blown film masterbatch?+
How does SEMITI 960 compare with Ti-Pure R-960 for ABS masterbatch?+
Does TiO2 affect food contact compliance?+
Need help picking a grade for plastic masterbatch?
Send us your reference grade, formulation type, or competitor TDS. We'll respond with the SEMITI match + sample within 48 hours.