SZ-12 (Neoalkoxy Phosphato-Zirconate, Kenrich NZ-12 Equivalent): The High-Temperature Workhorse Zirconate for ATH/MDH-Filled Engineering Plastics
SEMITECH SZ-12 is the neoalkoxy-phosphato-zirconate workhorse — Kenrich NZ-12 equivalent — for ATH/MDH-filled engineering plastics processed at 220–280°C where titanates degrade. Neopentyl-phosphato ligand provides 240°C thermal stability and phosphate anchor on ATH/MDH surfaces. 0.5–1.5 phr loading, 40–55% landed-cost discount vs Kenrich.
Contents
| NZ-12 | 0.5–1.5 phr | 240°C |
|---|---|---|
| Kenrich equivalent | Typical loading | Thermal stability |
Chemistry & Specifications
Zr(IV) with neoalkoxy ligand and pyrophosphate ester anchor; engineered thermal stability above 240°C.
SZ-12 combines neopentyl-glycolate (suppresses cyclic decomposition above 200°C) with pyrophosphato ester (strongly binds to ATH/MDH surfaces). SEMITECH supplies as clear amber liquid at ≥80% active, ZrO₂ 14.5–15.5%, phosphorus 5.5–6.5%, water ≤0.2%.
Pricing: ex-Zhejiang CNY 65,000–80,000/MT (USD 9–11/kg) vs Kenrich NZ-12 at USD 18–22/kg landed — 40–55% discount. The phosphato ligand also contributes phosphorus to char formation, providing 1–3 LOI units uplift vs non-phosphate zirconates.
Coupling Mechanism: Pyrophosphate Anchor + Neoalkoxy Polymer Compatibility
Phosphate anchors to ATH/MDH surface; neopentyl ligand extends into engineering polymer matrix; 240°C stable.
- Loading 0.5–1.0 phr — standard ATH-filled HFFR cable jacket compounds (60% filler loading)
- Loading 1.0–1.5 phr — high-LOI HFFR formulations (LOI 32+ at 60% ATH)
- Loading 0.7–1.2 phr — mineral-filled PA66, PBT, PPS engineering plastic compounds
- Loading 0.5–1.0 phr — talc-filled and CaCO₃/ATH co-filled compounds
PA66 (260°C), PBT (245°C), PPS (310°C) all process above 220°C where titanates degrade. SZ-12 retains coupling activity through the extruder dwell window. Wire & cable compounders report LOI 32+ at 60% ATH vs LOI 28–29 with titanates.
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Applications & Formulation Guidance
HFFR cable (largest), ATH-PA66, MDH-PBT/PPS engineering plastic, mineral-filled compound, fire-retardant moulding.
HFFR cable jacket compounds are the largest application — building wire, railway/metro cable, marine cable, automotive HV cable. Standard formulation: EVA/polyolefin 35–40%, ATH/MDH 55–60%, SZ-12 0.5–1.0 phr, compounded at 200–230°C. Typical: tensile 8–12 MPa, elongation 200–400% at 60% ATH vs 4–6 MPa without coupling.
Mineral-filled engineering plastics use SZ-12 at 0.7–1.2 phr for ATH-PA66, talc-PBT, and ATH/MDH-PPS compounds. Fire-retardant compression-moulded sheet at 1.0–1.5 phr in ATH-PE/EVA at 60–65% filler. Avoid SZ-12 in waterborne formulations — use SZ-2 instead.
Procurement, Storage and Quality Control
CoA per shipment; 25 kg HDPE under N₂; 12-month sealed shelf life; nitrogen-blanket discipline required.
Standard packing 25 kg HDPE jerrycans under N₂; 200 kg drums for bulk HFFR producers. MOQ 25 kg. Lead time 1–2 weeks to Asia, 4–6 weeks to Europe/North America. Store sealed under N₂ below 25°C; consume within 30 days of opening. Flash point 35–40°C (solvent carrier).
SZ-12 Specification Sheet
SEMITECH stocked grade; CoA per batch.
| Property | Specification | Test Method |
|---|---|---|
| Chemical name | Neoalkoxy tris(dioctylpyrophosphato) zirconate | — |
| Synonyms | NZ-12 equivalent / phosphato-zirconate / neoalkoxy-phosphato Zr | — |
| Form | ≥80% in n-propanol / n-butanol carrier | — |
| ZrO₂ content | 14.5–15.5% | Gravimetric ignition |
| Phosphorus content | 5.5–6.5% | ICP-OES |
| Active content | ≥80% | Titration |
| Appearance | Clear amber liquid | Visual |
| Density (20°C) | 1.04–1.06 g/cm³ | ASTM D1475 |
| Viscosity (25°C) | 50–80 cP | Brookfield |
| Water content | ≤0.2% | Karl Fischer |
| APHA colour | ≤300 | ASTM D1209 |
| Flash point | 35–40°C (solvent, closed cup) | ASTM D93 |
| Thermal stability | 240°C continuous | — |
| Solubility | n-propanol, n-butanol, toluene; reacts with water | — |
| Packaging | 25 kg HDPE under N₂ / 200 kg lined steel drum | — |
| Shelf life | 12 months sealed below 25°C under N₂ | — |
FAQ
+How much LOI uplift can I expect from switching from a titanate to SZ-12 in my ATH-EVA HFFR cable jacket?
Typical 1–3 LOI units at 60% ATH loading (LOI 31–33 vs titanate 28–30). SZ-12 retains coupling through the 220–230°C extrusion window where titanates degrade, and phosphorus contributes to char-forming chemistry. A 2-LOI uplift can move a compound from general LSZH to premium fire-rated pricing tier.
+Can I substitute SZ-12 for SZ-TPZ in a low-cost CaCO₃-PE wire compound?
Technically yes but economically wasteful. SZ-TPZ delivers equivalent coupling at 40–55% lower cost for CaCO₃-PE processed at 180–200°C. Reserve SZ-12 for applications requiring >200°C thermal stability or ATH/MDH filler coupling.
+Pre-coating filler vs in-situ compounding addition — which gives better coupling for SZ-12?
Pre-coating at 80–100°C in a high-speed mixer gives the most uniform coupling and is standard for production-scale HFFR cable. In-situ addition is acceptable for lab-scale but gives 15–25% lower coupling efficiency — compensate by raising loading 30–50%.