Emulsion composition for silicone rubber, process for producing the same, and process for producing silicone rubber

A method for preparation of an emulsion composition for manufacturing a silicone rubber, the emulsion composition comprising:

• (A) 100 parts by weight of a diorganopolysiloxane having at least two silicon-bonded alkenyl groups in a molecule;
• (B) 10 to 250 parts by weight of water that contains a smectite clay;
• (C) 0.1 to 15 parts by weight of an emulsifier;
• (D) (d1) a cross-linking agent in an amount sufficient for cross-linking component (A), and
• (d2) a catalyst;
• and
• (E) 0 to 60 parts by weight of a reinforcing silica filler, said method comprising the steps of mixing a mixture of an appropriate amount of component (A) and an appropriate amount of component (E) with an appropriate amount of components (d1) and (d2), loading the obtained mixture together with an appropriate amount of component (B) and an appropriate amount of component (C) into a high-speed stiffer-equipped mixer, and then stirring and mixing the components till a uniform emulsion is formed.

A method of manufacturing a silicone rubber comprising the steps of:

• heating an emulsion composition comprising;
• (A) 100 parts by weight of a diorganopolysiloxane having at least two silicon-bonded alkenyl groups in a molecule;
• (B) 10 to 250 parts by weight of water that contains a smectite clay;
• (C) 0.1 to 15 parts by weight of an emulsifier;
• (D) (d1) a cross-linking agent in an amount sufficient for cross-linking component (A), and
• (d2) a catalyst;
• and
• (E) 0 to 60 parts by weight of a reinforcing silica filler, thus forming a wet silicone rubber-like substance, and then
• dehydrating the obtained wet silicone rubber-like substance.

A method of manufacturing a silicone rubber comprising heating and dehydrating an emulsion composition comprising:

• (A) 100 parts by weight of a diorganopolysiloxane having at least two silicon-bonded alkenyl groups in a molecule;
• (B) 10 to 250 parts by weight of water that contains a smectite clay;
• (C) 0.1 to 15 parts by weight of an emulsifier;
• (D) (d1) a cross-linking agent in an amount sufficient for cross-linking component (A), and
• (d2) a catalyst;
• and
• (E) 0 to 60 parts by weight of a reinforcing silica filler.