LOCTITE SI 5900
Harmonization Code : 3506.91.90.99 | Prepared glues and other prepared adhesives, not elsewhere specified or included; products suitable for use as glues or adhesives, put up for retail sale as glues or adhesives, not exceeding a net weight of 1 kg ; Adhesives based on polymers of headings 3901 to 3913 or on rubber; Other ; Other
Main features
- High Movement Flange Sealing
- Engine Oil Resistance
- Thixotropic Application Control
Product Description
LOCTITE® SI 5900® is a one-component, room-temperature-vulcanizing oxime silicone sealant supplied as a black thixotropic paste. It is designed for formed-in-place sealing of stamped sheet-metal covers and flanges, including timing covers and oil sumps, where resistance to automotive engine oils and high joint movement is required. The moisture-curing material provides low migration after application, supports on-line low-pressure testing before full cure, and bonds to a broad range of metals, glass, ceramics, and plastic substrates.
Key features
- High-movement flange sealing: Forms a flexible elastomeric seal with at least 400% elongation at break.
- Excellent engine-oil resistance: Designed for automotive covers, oil sumps, and other demanding oil-exposed assemblies.
- Thixotropic one-component application: Requires no mixing, limits migration after dispensing, and supports low-pressure testing before full cure.
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Mechanical Properties
Additional Information
As-supplied / before-processing properties
Typical properties of the uncured material; values are reference data rather than guaranteed product specifications.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Technology | Silicone | — | Uncured material |
| Chemical type | Oxime silicone | — | Uncured material |
| Appearance | Black paste | — | Uncured material |
| Components | One component | — | No mixing required |
| Rheology | Thixotropic paste | — | Reduced migration after application |
| Cure mechanism | Room-temperature vulcanizing | RTV | Atmospheric moisture cure |
| Specific gravity | 1.30–1.37 | — | At 25°C |
| Extrusion rate | 20–50 | g/min | 0.62 MPa pressure, 15 seconds, 25°C; Semco cartridge |
| Blow-out resistance | ≥100 | s | 4 mm flange, 1.5 mm gap, 0.014 MPa |
| Flow | ≤0.2 | mm | ISO 7390; after 2 minutes at 25°C |
| Volatile content | ≤0.5 | % | Typical uncured-material property |
| Tack-free time | 7–24 | min | 25°C and 50 ± 5% RH |
| Density | 1.30–1.37 | g/cm³ | At 20°C; SDS value |
| pH | 7–9 | — | 20°C; 100% product; SDS value |
| Flash point | Not applicable | — | Product classified as a solid paste in the supplied SDS |
After-processing / final-state properties
Typical cured-material properties depend on cure time, temperature, humidity, bond gap, substrate, surface preparation, and test method.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Shore hardness | 31–46 | Shore A | ISO 868; cured 1 week at 25°C and 50 ± 5% RH |
| Elongation at break | ≥400 | % | ISO 37; cured 1 week at 25°C and 50 ± 5% RH |
| Tensile strength | ≥1.7 | N/mm² | ISO 37; cured 1 week at 25°C and 50 ± 5% RH |
| Volume resistivity | 6.7 × 1013 | Ω·cm | IEC 60093; cured material |
| Surface resistivity | 4.35 × 1015 | Ω | IEC 60093; cured material |
| Lap-shear strength | 1.0–1.4 | N/mm² | ISO 4587; mild steel; 0.5 mm gap; cured 21 days at 23°C and 50 ± 5% RH |
| Lap-shear strength | 0.7–1.3 | N/mm² | ISO 4587; aluminum 2024-T3; 0.5 mm gap; cured 21 days at 23°C and 50 ± 5% RH |
| Lap-shear strength | 1.0–1.5 | N/mm² | ISO 4587; Alclad; 0.5 mm gap; cured 21 days at 23°C and 50 ± 5% RH |
| Lap-shear strength | 1.0–2.0 | N/mm² | ISO 4587; zinc dichromate; 0.5 mm gap; cured 21 days at 23°C and 50 ± 5% RH |
| Lap-shear strength | ≥1.2 | N/mm² | Alclad aluminum; moisture cure only; cured 7 days at 25°C and 50 ± 5% RH |
| Lap-shear strength | ≥1.0 | N/mm² | Alclad aluminum to as-received steel; moisture cure only; cured 7 days at 25°C and 50 ± 5% RH |
