SZ-AcAc (Zirconium Acetylacetonate, Chelated): The Solvent-Borne Crosslinker Zirconate for Anti-Corrosive Primer and Marine Deck Paint
SEMITECH SZ-AcAc is the chelated zirconate — Zr(IV) tetra-acetylacetonate (CAS 17501-44-9) — hydrolytically stable for weeks in solvent-borne formulations and the solvent-borne counterpart to aqueous SZ-2. Used at 0.3–1.0% on resin solids in anti-corrosive primer, marine deck paint, and high-build epoxy. 25 kg HDPE, 200°C thermal stability.
Contents
| 17501-44-9 | 0.3–1.0% | 200°C |
|---|---|---|
| CAS number | Typical loading | Thermal stability |
Chemistry & Specifications
Zr(IV) tetra-acac chelate; pale-yellow crystalline solid or 50% IPA/toluene solution; bidentate chelation.
SZ-AcAc (Zr(C₅H₇O₂)₄, MW 487.6, mp 195°C) has four bidentate acac ligands providing hydrolytic stability from minutes (bare alkoxide) to weeks (chelated). SEMITECH supplies as dry crystalline solid (≥98%) or 50% IPA/toluene solution. CoA: ZrO₂ 24.5–25.5% (dry) or 12.3–12.8% (solution), free acetylacetone ≤0.5%, water ≤0.3%.
Pricing: CNY 75,000–95,000/MT (dry) vs Kenrich-equivalent at USD 18–25/kg — 30–45% discount.
Coupling Mechanism: Latent Chelate → Heat / Acid Activation → Active Zr(IV) Crosslinking
Acac chelates lock Zr against hydrolysis; thermal or pH-shift activation releases active Zr for hydroxy-resin crosslinking.
Activation via heat (>100°C dissociates one acac ligand) or acid-induced ligand exchange during dry-down. Once activated, SZ-AcAc forms Zr-O-C ester bridges between hydroxyl-functional resin chains.
- Loading 0.3–0.6% Zr on resin solids — solvent-borne 1K alkyd primer; salt-spray uplift
- Loading 0.6–1.0% on resin solids — high-build anti-corrosive primer (200+ µm DFT)
- Loading 0.5–1.5% on resin solids — marine deck paint and immersion-service coatings
- Loading 1.0–2.0% on resin solids — solvent-borne ink crosslinker for high-temperature offset and roto-gravure
Compatible with alkyd, polyester, acrylic-OH, epoxy-OH, and modified-PU binders at pH 4–9. Incompatible with strong acids (premature activation) and primary amines (ligand exchange on storage).
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Applications & Formulation Guidance
Anti-corrosive primer (largest), marine deck paint, high-build epoxy crosslinker, solvent-borne ink, alkyd paint film hardener.
Solvent-borne anti-corrosive primer is the largest application — industrial machinery, agricultural equipment, structural steel. Alkyd + zinc phosphate + SZ-AcAc 0.5% gives 500–800 hour salt-spray. Marine deck paint at 0.5–1.5% for immersion-water and fuel resistance.
High-build epoxy primer (200+ µm DFT) at 0.6–1.0% for offshore and bridge structures. Solvent-borne ink crosslinker at 1.0–2.0% for rub and water resistance on metal/plastic substrates. Alkyd film hardener at 0.3–0.5% as co-drier alongside Co/Mn siccatives.
Procurement, Storage and Quality Control
CoA per shipment; 25 kg HDPE drums; 12-month sealed shelf life; tolerates ambient humidity unlike bare SZ-TPZ.
Dry crystalline in 25 kg fibre drums (24-month shelf life); 50% IPA solution in 25 kg jerrycans (12-month). MOQ 25 kg. Lead time 2–4 weeks to Asia, 4–6 weeks to Europe/North America. IPA solution flash point 22°C requires flammable storage. REACH-registered.
SZ-AcAc Specification Sheet
Two forms stocked: dry crystalline ≥98% and 50% IPA solution. CoA per batch.
| Property | Dry Crystalline | 50% IPA Solution |
|---|---|---|
| Chemical name | Zirconium tetra-acetylacetonate | Zirconium tetra-acetylacetonate |
| CAS number | 17501-44-9 | 17501-44-9 |
| Molecular formula | Zr(C₅H₇O₂)₄ | Zr(C₅H₇O₂)₄ in IPA |
| Molecular weight | 487.6 g/mol | 487.6 g/mol |
| Form | Pale-yellow crystalline solid | 50 wt% in isopropanol |
| ZrO₂ content | 24.5–25.5% | 12.3–12.8% |
| Active content | ≥98% | 50 ± 1% |
| Free acetylacetone | ≤0.5% | ≤1.0% |
| Water content | ≤0.3% | ≤0.5% |
| Melting point | 195°C (with decomp.) | N/A (solution) |
| Density (20°C) | N/A | 0.92–0.95 g/cm³ |
| Flash point | N/A (solid) | 22°C (solvent, closed cup) |
| Thermal stability | 200°C continuous | 200°C continuous |
| Solubility | Soluble in IPA, toluene, MEK | Miscible with most solvents |
| Packaging | 25 kg HDPE-lined fibre drum | 25 kg HDPE jerrycan |
| Shelf life | 24 months sealed below 30°C | 12 months sealed below 30°C |
FAQ
+Should I order the dry crystalline SZ-AcAc or the 50% IPA solution form?
Dry for production plants with on-site solvent mixing, higher purity needs, and bulk shipping economics (60% better Zr cost on freight). Solution for lab-scale work, convenience, and small trial quantities.
+How is SZ-AcAc different from titanate TET (Tyzor AA) for the same paint application?
Functionally similar. SZ-AcAc provides 30–50% more hydrolytically stable Zr-O-C bonds for better immersion-service and salt-spray performance — preferred for marine and chemical-process coatings. TET is ~30% cheaper per metal-mole for general adhesion promotion.
+Why does my SZ-AcAc-catalysed alkyd primer show poor through-cure in 200 µm films?
The chelate is too stable at room temperature in deep films. Solutions: oven cure at 100–120°C for 30 min, add 0.05–0.10% acidic catalyst (pTSA), or reduce SZ-AcAc to 0.6% and add Co/Mn siccative as primary drier.