Claims
- 1. A curable organopolysiloxane composition comprising the admixture of a platinum catalyst composition, at 0.1 to 100 parts by weight of paltinum atoms, with a million parts by weight of a mixture of an organopolysiloxane having at least 2 alkenyl groups in each molecule and organohydrogenpolysiloxane having at least 2 silicon-bonded hydrogen atoms in each molecule, said platinum catalyst composition comprising
- (A) a platinum complex having as a ligand an organosiloxane which has no more than 8 silicon atoms in each molecule and contains alkyl and alkenyl groups and which has in each molecule at least one bond as represented by the formula ##STR5## wherein R.sup.1 is an alkyl group having no more than 6 carbon atoms and R.sup.2 is an alkenyl group, or a mixture of said platinum complex and said organosiloxane; and
- (B) an organosiloxane which contains aryl and alkenyl groups and has no more than 8 silicon atoms in each molecule and which contains in each molecule at least one bond as represented by the formula ##STR6## wherein R.sup.3 is an aryl group and R.sup.2 is defined as above, in a quantity of at least 2 moles of component (B) per 1 mole platinum atoms in component (A).
- 2. A curable organopolysiloane composition in accordance with claim 1 in which the organopolysiloxane of component (A) is 1,3-divinyltetramethyldisiloxane and component (B) is 1,3-divinyl-1,3-diphenyldimethyldisiloxane.
- 3. A curable organopolysiloxane composition in accordance with claim 1 wherein the platinum catalyst composition further comprises a platinum complex having as a ligand an organosiloxane which has no more than 8 silicon atoms in each molecule and contains aryl and alkenyl groups and which contains in each molecule at least one bond as represented by the formula ##STR7## wherein R.sup.3 is an aryl group and R.sup.2 is an alkenyl group.
- 4. A curable organopolysiloxane composition in accordance with claim 3 in which the organopolysiloxane of component (A) is 1,3-divinyltetramethyldisiloxane and the organosiloxane ligand which has no more than 8 silicon atoms in each molecule nd contains aryl and alkenyl groups and which contains in each molecule at least one bond as represented by the formula ##STR8## wherein R.sup.3 is an aryl group and R.sup.2 is an alkenyl group is 1,3-divinyl-1,3-diphenyldimethyldisiloxane.
- 5. A curable organopolysiloxane composition in accordance with claim 4 in which the platinum catalyst composition is free of uncomplexed divinyltetramethyldisiloxane.
- 6. A curable organopolysiloxane composition comprising the admixture of a platinum catalyst composition, at 0.1 to 100 parts by weight of platinum atoms, with a million parts by weight of a mixture of an organopolysiloxane having at least 2 alkenyl groups in each molecule and organohydrogenpolysiloxane having at least 2 silicon-bonded hydrogen atoms in each molecule, said platinum catalyst composition having been prepared by a method comprising mixing
- (A) a platinum complex having as a ligand an organosiloxane which has no more than 8 silicon atoms in each molecule and contains alkyl and alkenyl groups and which has in each molecule at least one bond as represented by the formula ##STR9## wherein R.sup.1 is an alkyl group having no more than 6 carbon atoms and R.sup.2 is an alkenyl group, or a mixture of said platinum complex and said organosiloxane; and
- (B) an organosiloxane which contains aryl and alkenyl groups and has no more than 8 silicon atoms in each molecule and which contains in each molecule at least one bond as represented by the formula ##STR10## wherein R.sup.3 is an aryl group and R.sup.2 is defined as above, in a quantity of at least 2 moles of component (B) per 1 mole platinum atoms in component (A).
- 7. A curable organopolysiloxane composition in accordance with claim 6 in which the organopolysiloxane of component (A) is 1,3-divinyltetramethyldisiloxane and component (B) is 1,3-divinyl-1,3-diphenyldimethyldisiloxane.
- 8. A curable organopolysiloxane composition in accordance with claim 6 in which said method further comprises removing at least a portion of the organosiloxane in component (A) by distillation in vacuo.
- 9. A curable organopolysiloxane composition in accordance with claim 8 in which the organopolysiloxane of component (A) is 1,3-divinyltetramethyldisiloxane and component (B) is 1,3-divinyl-1,3-diphenyldimethyldisiloxane.
- 10. A curable organopolysiloxane composition in accordance with claim 9 wherein at least a portion of the complexed divinyltetramethyldisiloxane is removed.
Parent Case Info
This is a divisional of copending application Ser. No. 07/570,669 filed on Aug. 22, 1990, now U.S. Pat. No. 5,057,476.
US Referenced Citations (4)
Divisions (1)
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Number |
Date |
Country |
Parent |
570669 |
Aug 1990 |
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