| 主权项 |
1. An antifoam composition comprising:
a) an organomodified silicone comprising one or more 2-phenylpropylmethyl moieties, preferably 1 to 75 mole percent 2-phenylpropylmethyl moieties, more preferably 5 to 50 mole percent 2-phenylpropylmethyl moieties, more preferably 5 to 40 mole percent 2-phenylpropylmethyl moieties, most preferably 15 to 35 mole percent 2-phenylpropylmethyl moieties; b) silica; c) a siloxane polymer, said siloxane polymer having a viscosity of from about 0.5 cSt to about 10,000 cSt, of from about 0.5 cSt to about 5,000 cSt, of from about 0.5 cSt to about 1,000 cSt, of from about 2 cSt to about 1,000 cSt, preferably of from about 1 cSt to about 750 cSt, more preferably of from about 1 cSt to about 500 cSt, more preferably of from about 1 cSt to about 100 cSt, most preferably of from about 1 cSt to about 20 cSt; said siloxane polymer having a viscosity that is about 5%, about 10%, about 20%, about 40%, about 50%, about 60%, about 75%, about 90%, about 99%, less than that of said organomodified silicone; and d) a silicone resin;said antifoam composition having a viscosity, at a shear rate of 20 sec−1 at 25° C., of from about 250 cSt to about 20,000 cSt, preferably of from about 500 cSt to about 10,000 cSt, more preferably of from about 1,000 cSt to about 7,000 cSt, most preferably of from about 1,000 cSt to about 4,000 cSt; a ratio of organomodified silicone to silica of from about 2:1 to about 500:1, preferably of from about 3:1 to about 100:1, more preferably of from about 4:1 to about 70:1, most preferably of from about 5:1 to about 50:1. |
