How to choose the right silicone vulcanizing agent?

分类: Industry News

2022-01-14

Silicone vulcanizing agents currently include bis‑dibutyltin dilaurate, bis‑dipentyltin dilaurate, platinum‑based vulcanizers, and several others. How do you choose the right vulcanizing agent? Below, we’ll provide a detailed explanation.
 

1. Bis(2-ethylhexyl) disulfide:
Bis‑2,4‑dithiol crosslinking agents are primarily used for crosslinking during the extrusion and calendering of silicone rubber products. They are well suited for producing extruded parts with modest quality requirements. They exhibit moderate yellowing resistance, have a noticeable odor, and cure at a relatively slow rate. As such, they are a common vulcanizing agent for compounded rubbers in applications where extrusion‑molded parts do not demand particularly high performance.
                                               

2. Double-25 vulcanizing agent
Bis‑2,5‑dithiacyclopentane is primarily used as a crosslinking agent in the molding of silicone rubber products. It has a mild odor, a moderate vulcanization rate, is non‑volatile, and does not ignite. It is suitable for molded silicone products across a wide range of applications, meeting environmental standards—such as silicone keypads, wristbands, phone cases, watch straps, silicone promotional gifts, and more.
                                            

3. Platinum Vulcanizing Agent
Platinum catalysts are categorized into two‑component and one‑component types. They are primarily used for low‑temperature vulcanization and for molding and extrusion processes where odorless silicone products are required. These catalysts offer excellent yellowing resistance, are odorless, require only small addition levels, and provide rapid cure rates. Products cured with platinum catalysts can achieve FDA and RoHS compliance in a single‑stage cure, while two‑stage curing can meet LFGB certification standards.

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