DOWSIL™ SJ668 Sealant
Features &Benefits
Some of the key features and benefits of DOWSIL™ SJ668 Sealant include:
High Strength: It provides high-strength bonding for a variety of substrates, including plastics, metals, and glass.
Low Modulus: The low modulus of the sealant allows it to maintain its flexibility and elasticity, even after prolonged exposure to temperature extremes and vibration.
Moisture-Cure: DOWSIL™ SJ668 is a moisture-cure silicone sealant, which means that it cures by reacting with moisture in the air, and does not require mixing or other special equipment.
Neutral-Curing: The sealant is a neutral-curing silicone, which means that it does not release any acidic byproducts during curing, and can be safely used on sensitive electronic components and modules.
Electrical Insulation: DOWSIL™ SJ668 provides excellent electrical insulation properties, making it ideal for use in electronic applications where electrical conductivity must be avoided.
Temperature Resistance: The sealant can withstand temperatures ranging from -40°C to 150°C (-40°F to 302°F) without losing its adhesion or flexibility.
| Test Standard Test Item Unit Value | |
| As supplied - DOWSIL SJ668 Sealant Base | |
| Color and Physical Form Grey viscous paste | |
| Specific Gravity 1.36 | |
| As supplied - DOWSIL SJ668 Sealant, Curing Agent | |
| Color and Physical Form Thick black paste | |
| Specific Gravity 1.08 | |
| Color and Physical Form Clear paste | |
| Specific Gravity 1.00 | |
| After catalyzed and mixed: | |
| Color and Physical Form Black non-sagging
paste |
|
| Specific Gravity 1.34 | |
| Color and Physical Form Grey non-sagging
paste |
|
| Specific Gravity 1.32 | |
| Corrosivity Non-corrosive | |
| CTM0092A1 Snap Time (25°C/77°F, 50%R.H) Min. 40 to 70 | |
| GB134771 Shore Hardness 40 | |
| 14 Days after cure n(25°C, 50%R.H.) - Test on H-shaped Specimen | |
| GB13477 Tensile Strength (room
temperature) |
MPa 1.0 |
| GB13477 Tensile Strength (90°C) MPa 0.9 | |
| GB13477 Tensile Strength (-30°C) MPa 1.3 | |
| GB13477 Tensile Strength (water
immersion) |
MPa 0.9 |
Applications
DOWSIL™ SJ668 Sealant is primarily used in the electronics industry for bonding and sealing electronic components and modules. Some common applications of DOWSIL™ SJ668 Sealant include:
Bonding and Sealing Circuit Boards: DOWSIL™ SJ668 is often used to bond and seal circuit boards in electronic devices, providing reliable adhesion and protection against moisture, dust, and other environmental factors.
Sealing Electrical Connections: The sealant can be used to seal electrical connections, preventing moisture and other contaminants from interfering with the electrical signal.
Potting Electronic Components: DOWSIL™ SJ668 can be used to pot electronic components, providing protection against shock, vibration, and environmental factors.
Bonding Displays and Touchscreens: The sealant can be used to bond displays and touchscreens to electronic devices, providing a high-strength bond and protection against moisture and other environmental factors.
Standard
UL Recognition: DOWSIL™ SJ668 is UL recognized for use in a wide range of electronic applications, including bonding and sealing of various components and materials.
RoHS Compliance: The sealant is compliant with the Restriction of Hazardous Substances (RoHS) directive, which restricts the use of certain hazardous materials in electronic products.
How to Use
Here are the general steps to use DOWSIL™ SJ668 Sealant:
Clean the Surfaces: Make sure the surfaces you will be bonding or sealing are clean and free from dust, grease, and other contaminants. Use a solvent, such as isopropyl alcohol, to clean the surfaces if necessary.
Cut the Nozzle: Cut the nozzle of the sealant tube to the desired size, and attach it to a caulking gun or other dispensing equipment.
Apply the Sealant: Apply the sealant in a continuous bead along the surfaces to be bonded or sealed, using steady pressure on the caulking gun or other dispensing equipment.
Tool the Sealant: Use a tool, such as a wet finger or a spatula, to smooth or shape the sealant as desired.
Allow to Cure: Allow the sealant to cure for the recommended time, which will depend on the temperature, humidity, and other environmental factors. Refer to the product data sheet for specific curing instructions.
Clean Up: Clean up any excess sealant using a solvent or other appropriate cleaning material before it cures.
Usable Life and Storage
Usable Life: DOWSIL™ SJ668 Sealant typically has a usable life of 12 months from the date of manufacture when stored in its original, unopened container. Once the sealant is opened, its usable life may be shorter, depending on the storage conditions.
Storage Conditions: The sealant should be stored in a cool, dry place at a temperature between 5°C and 25°C. It should be protected from direct sunlight and moisture. Avoid storing the sealant near heat sources or open flames.
