Shin-Etsu KE-420 Clear RTV Silicone Sealant

Description

Shin-Etsu KE-420 One Component Silicone Sealant is an optically clear RTV adhesive and sealant for applications that need transparent elastomeric sealing on metal, plastic, glass, or ceramic parts. KE-420 sealant cures at room temperature to a tough silicone rubber and has a thixotropic paste body for controlled placement.

KE-420 sealant Benefits

• Optically clear cured appearance supports visible glass, display, and electronics work.
• One-component format removes mix-ratio checks and static mixer waste.
• Thixotropic paste helps the bead stay placed on vertical or shaped parts.
• Unprimed adhesion is listed for metals, plastics, glass, and ceramics.
• Condensation cure gives shops a room-temperature RTV option for sealing tasks.

Use this material when the job needs a clear seal, a flexible cured elastomer, and a controlled bead. It is a fit for electronics sealing, form-in-place gasketing, and assemblies where a rigid adhesive would put too much stress into the joint.

Common Uses for KE-420 sealant

• Electronics enclosure sealing
• Clear glass-to-metal or glass-to-plastic sealing
• Form-in-place gasket beads
• Ceramic and plastic component sealing
• Transparent repair or assembly work where color matters

Surface Preparation and Use

Clean the surface until it is dry and free of oil, dust, release agent, and fingerprints. Apply a consistent bead and allow enough moisture exposure for room-temperature cure. Deep sections and enclosed joints can cure more slowly than thin exposed beads.

For production use, test adhesion on the actual substrate lot. Plastics, coatings, and cleaning chemistry can change bond results, even when the base material name looks the same on a drawing.

Technical Details and Documentation

Manufacturer data identifies KE-420 as a transparent, one-component condensation-cure adhesive and sealant with density of 1.05 g/cm3 at 23 C, tack-free time of 5 minutes, Shore A hardness of 30, tensile strength of 2.10 MPa, elongation of 400 percent, dielectric strength of 20 kV/mm, refractive index of 1.46, and usable temperature range from -40 to +180 C. For silicone sealant selection background, review the Adhesive and Sealant Council.

Ordering Help

Review the current technical data sheet before production approval, especially for cure schedule, adhesion testing, and electrical requirements. Browse Chemical Concepts silicone adhesives for related clear, flexible, and RTV options.

For help matching silicone cure, clarity, and substrate requirements, call (800) 220-1966 or email [email protected].