Shin-Etsu CAT22251-20 Addition Cure Silicone Catalyst

Description

CAT22251-20 catalyst is the Shin-Etsu catalyst used with SES22251 base silicone to make a 20 Shore A addition-cure mold rubber. The published Shin-Etsu data lists a 100:10 base-to-catalyst mix ratio by weight, translucent appearance, and a 24 hour cure at 23 C.

CAT22251-20 catalyst Benefits

• Pairs with a common SES22251 base so shops can choose durometer by catalyst grade.
• 20 Shore A cured hardness gives a softer mold option for detailed release work.
• 90 minute working time supports careful mixing, degassing, and pour setup.
• High elongation data supports flexible molds around undercuts and complex shapes.
• Addition-cure chemistry fits mold making programs that need low shrinkage.

This catalyst is best ordered by exact part number because the catalyst grade controls the final hardness. Keep catalyst containers labeled and separated from other Shin-Etsu grades at the molding bench.

CAT22251-20 catalyst Applications

• Flexible molds for prototype parts and short production runs.
• Detailed tooling where a softer silicone helps release complex geometry.
• Replica casting with urethane, epoxy, wax, or gypsum after compatibility testing.
• Lab and model-shop work using measured 10:1 silicone systems.
• Replacement catalyst stock for existing SES22251 procedures.

Surface Preparation and Use

Use clean mixing cups, accurate scales, and dry tools. Contamination can interfere with cure, so keep sulfur clay, amines, tin-cure residues, and other cure inhibitors away from the mix area. Measure by weight and scrape the sides and bottom of the cup during mixing.

Test on the actual master pattern before pouring a production mold. For detailed parts, degas under vacuum if the process allows it, then pour slowly into the lowest area of the mold box.

Technical Details and Documentation

Shin-Etsu lists the CAT22251-20 cured system at 1.06 g/cm3 density, 50 Pa.s base viscosity, 6.70 MPa tensile strength, 19 kN/m tear strength, 800 percent elongation, and -40 C to +175 C usable temperature range. Review current product information from Shin-Etsu Silicone before production use.

Ordering Help

For related mold rubber and casting supplies, browse Chemical Concepts molding materials. For help confirming the right catalyst grade, call (800) 220-1966 or email [email protected].