Room Temperature Vulcanizable Single Component Silicone Rubbers

1 Room Temperature Vulcanizable Single Component Silicone Rubbers 

The reaction of a polydimethylsiloxane with hydroxy-groups at either end with an excess of a silane, which contains, as does methyltriacetoxysilane, at least three hydrolyzable silicon-functional groups (a crosslinking agent), results in a silicone polymer with at least four silicon-functional end groups  

Mixing of polydiorganosiloxancs with hydroxy-groups al both ends with crosslinking agents in the presence ol fillers and Sn-organic compounds as condensation catalyst leads to room temperature vulcani/,ed silicone rubber 

The resulting silicon-functional polysiloxane is stable during storage in the absence of moisture e.g. after filling in a cartouche. 

Such silicone polymers are stable upon storage in the absence of moisture, e.g. filled in a closed cartouche,. Upon contact with moisture, e.g. humidity in the air, hydroxy-groups are formed at either end of the polymer chain with the cleavage of acetic acid, which react, e.g. with one another with the cleavage of water, to form a crosslinked rubber-elastic material. The crosslinking starts at the surface and then spreads into the mass as the moisture diffuses into the polymer. 

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