Product Overview
The dual functionality is the point: Si-H sites drive hydrosilylation with unsaturated olefins, while Si-N and Si-H bonds react readily with hydroxyl-containing substances — so one precursor serves ceramic conversion, amine-type curing-agent duty and heat-resistance modification of phenolic, epoxy, alkyd and acrylic resins.
As a coating binder it delivers ≥6H hardness and >500 h salt spray from a thin 10 µm-class film, serving continuously at 350 °C; compounded with heat-resistant nanofillers it withstands direct flame and high-temperature airflow erosion.
Key Benefits
Dual Si-H / Si-vinyl reactivity
Hydrosilylation sites plus vinyl unsaturation in one molecule — a self-contained crosslinking pair for ceramic and hybrid systems.
High-molecular-weight grade
Relative molecular mass >8×10⁴ builds film integrity and ceramic yield that low-MW silazanes cannot match.
Si-C-N ceramic precursor
Thermal conversion to SiCNO/SiCN or silica ceramics — the raw material route to ceramic coatings, fibers and matrix composites.
Thin-film protection at 350 °C
A cured 10 µm-class film gives ≥6H hardness, >500 h salt spray and continuous 350 °C service with 500 °C excursions.
Typical Applications
- Si-C-N ceramic precursor
- Flame/high-temperature airflow-resistant coatings with nanofillers
- Heat/weather-resistance modification of phenolic, epoxy, alkyd and acrylic resins
Solution guides: Ceramic Precursors & Advanced CeramicsResin, Rubber & Composite Modification
Technical Data
| Test Item | Performance Indicator | Test Method |
|---|---|---|
| Color & Appearance | Pale yellow to colorless transparent liquid | GB/T 1721-1979 |
| Viscosity (Ford Cup 4) | 35–50 s | GB/T 1723-1993 |
| Purity | ≥95% | Q/YX 10-2023 |
| Solid Content (120 ± 2°C) | >98% | GB/T 1725-2007 |
| Density | 1.05 ± 0.01 g/mL | GB/T 6750-2007 |
| Relative Molecular Mass | >8×10⁴ | GB/T 27843-2011 |
| Pencil Hardness | ≥6H | GB/T 6739-2006 |
| Adhesion | Grade 0 | GB/T 9286-1998 |
| Salt Spray Resistance | >500 h | GB/T 10125-2021 |
| Reactive Groups | Si-H + Si-vinyl (methylhydro- & methylvinylsilazane) |
| Dilution | High viscosity — 50% dilution recommended before application |
| Theoretical Coverage | 12–28 m²/kg |
| Curing Temperature | 180–250 °C |
| Curing Time | 1 h |
| Dry Film Thickness | 10 ± 5 µm (keep ≤15 µm) |
| Working Time (after opening) | 24 h |
| Recommended Operating Temperature | -30 to 300 °C (continuous 350 °C, max 500 °C) |
| Thinner | Aromatics, esters, ethers |
| Flash Point | <22 °C (solvent) |
| Storage Temperature | 0–30 °C |
Values from the SILZ-350 technical data sheet. Complete TDS with test conditions available on request.
Curing & Processing Guidance
SILZ-350 is supplied as a high-viscosity varnish (35–50 s, Ford Cup 4); dilute about 50% with aromatic, ester or ether solvents before spraying. Prepare metal substrates to Sa 2.5 (minimum St 3) and ensure a clean, dry surface.
Apply one thin coat targeting 10 ± 5 µm dry film and do not exceed 15 µm — precursor films densify during cure, and over-thick films lose performance. Theoretical coverage runs 12–28 m²/kg diluted.
Cure at 180–250 °C for about 1 hour. Opened material stays workable for 24 hours; clean tools promptly. For ceramic-conversion work, pyrolysis schedules above the cure window are application-specific — our lab supports thermal-profile design.
Substrate Compatibility
Carbon steel, stainless steel, cast iron, aluminum alloy, titanium alloy, high-temperature alloy steel, glass-ceramics, ceramics and cement. As a resin modifier or ceramic precursor, compatibility is defined by your matrix system — send us the resin or fiber system and target service temperature.
SILZ-350 — Purchasing & Application FAQ
What is the difference between SILZ-350 and SILZ-702?
Both are high-molecular-weight heat-curing silazanes with near-identical film data. SILZ-350 carries Si-H plus vinyl groups (methylhydro- and methylvinylsilazane), giving it a built-in hydrosilylation pair; SILZ-702 is Si-H only. Choose 350 when you want self-crosslinking or vinyl reactivity, 702 when a pure Si-H feedstock fits your chemistry.
Can SILZ-350 be used for ceramic matrix composites?
Yes — thermal conversion to SiCNO/SiCN makes it a standard Si-C-N precursor for coatings, fibers and CMC matrix work. Ceramic yield and phase depend on your pyrolysis atmosphere and schedule; we share starting profiles with samples.
Why must the film stay below 15 µm?
Precursor coatings shrink as they densify during heat cure. Above roughly 15 µm the film accumulates stress and performance drops — build thickness with system design (fillers, multiple thin coats validated per application), not one thick pass.
TDS / SDS / COA & Samples
Technical Data Sheet, Safety Data Sheet and batch Certificate of Analysis are available for SILZ-350, and a COA accompanies every shipment. Evaluation samples ship with starting-parameter guidance.
Packaging: Available in 1 kg, 2 kg, 5 kg and 25 kg pails. Store at 0–30 °C in the original sealed container.
SDS & batch COA on request · Reply within 1 business day.