- Adhesion promotion for plastics. Dow DOWSIL PR-1205 Prime Coat is a one-component, dilute solution of silane coupling agents used to increase the bonding of room-temperature and heat-curing silicones to a variety of surfaces such as plastics, metals, and ceramics. Dow notes it is specially formulated to increase adhesion of a wide range of silicones to plastics, including more difficult types such as acrylic and polycarbonate.
- How primers work. As with Dow's other prime coats, PR-1205's surface-reactive silane components must be applied in a very thin layer to achieve optimal bonding. The solvent carrier delivers the active ingredients in a thin, uniform coating and aids surface cleaning, helping the silicone form a strong bond to the treated substrate.
- Important limitation. Dow notes PR-1205 is not recommended for use with addition-cure silicones such as SYLGARD 170, 184, and 186 Silicone Elastomer Kits. It is intended for use with the RTV and heat-cure silicones it is formulated to promote, particularly on plastics, ceramics, and composites.
- Application and storage. Apply in a very light, even coat by wiping, dipping, or spraying, wiping off excess to avoid a white, chalky over-application. Because it is moisture-sensitive, store below 32°C, keep tightly closed, and do not use if it becomes milky. Review the product and Safety Data Sheets before use.
Recommended For
- Promoting silicone adhesion to plastics
- Bonding to difficult plastics (acrylic, polycarbonate)
- Bonding to metals and ceramics
- Surface preparation before sealing or coating
- Improving reliability of bonded assemblies
Product Details
- Product type: One-part silane-based adhesion promoter / primer
- Color: Clear (light straw per some distributor data)
- Formulated for: Plastics including acrylic and polycarbonate; also metals and ceramics
- Not recommended for: Addition-cure silicones (e.g. SYLGARD 170/184/186)
- Storage: Below 32°C; keep tightly closed; protect from moisture
- Container size: 348 g can
Primary Industries
- Electronics and PCB manufacturing
- Plastics fabrication and assembly
- Industrial bonding and sealing
- Consumer product manufacturing
Standards and Certifications
- None specified by source



