BOSTIK 70-03A
Harmonization Code : 3208.20.90 | Paints and varnishes that are dispersed or dissolved in a non aqueous medium

Main features
- 2.5 MPa Lap Shear
- Primerless Multi-Substrate Adhesion
- Up to 120 deg C Service
Product Description
Bostik 70-03A is a one-component, moisture-curing adhesive and sealant based on Silyl Modified Polymer technology. It is designed for high-strength elastic construction joints and general bonding and sealing applications. The solvent-, isocyanate-, and PVC-free formulation combines high green strength, low residual tack, primerless adhesion on many substrates, and excellent UV and weather resistance. It remains permanently elastic from -40°C to 100°C and is compatible with most industrial paint and lacquer systems, subject to compatibility testing.
Key Features
- High-strength elastic bonding: Provides approximately 2.5 MPa lap shear strength and 250% elongation at break.
- Primerless adhesion: Adheres to many metals, glass, PVC, polyester, and painted or lacquered wood when surfaces are properly prepared.
- Durable environmental performance: Offers excellent UV and weather resistance with temperature resistance from -40°C to 120°C.
- Fast processing: Provides a 10-minute skin-forming time and less than 15 minutes of open time at 20°C and 50% relative humidity.
Applications / Suitable for
- Sunroof assemblies
- Composite assembly
- Elastic bonding and sealing in buses, caravans, trains, and trucks
- Bonding vehicle roofs, floor systems, corner profiles, and polyester components
- Sealing welded seams
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Thermal Properties
Additional Information
As-Supplied / Before-Processing Properties
| Property | Value | Unit | Method / Condition |
|---|---|---|---|
| Basic material | Silyl Modified Polymer | — | Supplier classification |
| Curing method | Moisture cure | — | One-component system |
| Specific gravity | Approx. 1.4 | g/mL | Typical value |
| Skin-forming time | 10 | minutes | 20°C and 50% RH |
| Open time | <15 | minutes | 20°C and 50% RH |
| Curing speed after 24 hours | 3 (0.125) | mm (in.) | Typical value |
| Green strength | 300 | Pa | Physical Rheometer MC100 |
| Application temperature | 5 to 35 (40 to 95) | °C (°F) | Supplier recommended range |
| Shelf life | 18 months for cartridges; 12 months for sausages | — | Unopened packaging stored dry at 5°C to 30°C |
After-Processing / Final-State Properties
| Property | Value | Unit | Method / Condition |
|---|---|---|---|
| Shore A hardness | Approx. 55 | Shore A | Typical cured property |
| Volume change | <3 | % | Typical cured property |
| Tensile stress at 100% elongation | 2.3 (245) | MPa (psi) | Typical cured property |
| Tensile stress at break | 2.6 (275) | MPa (psi) | Typical cured property |
| Elongation at break | 250 | % | Typical cured property |
| Lap shear strength | 2.5 (360) | MPa (psi) | Typical cured property |
| E-modulus at 10% | 3.3 (475) | MPa (psi) | Typical cured property |
| Temperature resistance | -40 to 120 (-40 to 250) | °C (°F) | Continuous resistance |
| Short-term temperature resistance | 180 (350) | °C (°F) | Maximum 30 minutes |
| UV and weather resistance | Excellent | — | Supplier classification |





















