Types of Silicone Rubber Curing Agents
Acidic Curing Agents:
These are the earliest developed and used silicone curing agents. Common examples include acid anhydrides, acid esters, and acid oxides. These curing agents have a slower reaction rate at room temperature and require catalysis at high temperatures. The by-products produced from the reaction between these curing agents and silicone are relatively few, and they are cost-effective. They are widely used in the preparation of silicone rubber, silicone resins, silicone oils, and other products.
Peroxide-based Curing Agents:
This is a newer type of silicone curing agent that features fast curing speed, fewer reaction by-products, and good heat resistance. Common peroxides include methyl vinyl methyl phenyl peroxide and p-cresol peroxide. They are mainly used in the preparation of high-temperature silicone rubber, coatings, sealants, and other products.
Alkylating Curing Agents:
These curing agents have high reactivity and include compounds such as methyl silane, phenyl silane, and vinyl silane. Due to their high reactivity, alkylating curing agents typically require a shorter reaction time to prevent irreversible crosslinking. They are mainly used in heat-resistant silicone rubber, coatings, adhesives, and other fields.
Platinum-based Curing Agents:
This is also a newer type of silicone curing agent known for its high reactivity, few by-products, and fast curing speed. Platinum-based curing agents typically contain platinum-containing organosilicon compounds, such as hydrosilyl methyl phenyl platinum and catalyst 1. They are primarily used in high-performance silicone rubber, high transparency silicone rubber, high-hardness silicone rubber, and similar applications.
Sulfur-based Silicone Rubber Curing Agents:
These are traditional curing agents commonly used for vulcanization reactions. Among them, disulfides are the most frequently used sulfur curing agents.
Heat-activated Silicone Rubber Curing Agents:
These curing agents trigger curing reactions under heat and typically include compounds such as hydrogen peroxide and calcium.
Photocurable Silicone Rubber Curing Agents:
This is a new type of curing agent that uses ultraviolet (UV) light or electron beam radiation to initiate curing. These agents offer excellent selectivity and reactivity.