초록 ▼

A process for the preparation of an organosilicon condensate which comprises reacting together (A) at least one silicon containing compound having at least one silanol group; and (B) at least one silicon containing compound having at least one —OR group in the presence of (C) a calcium or mag

A process for the preparation of an organosilicon condensate which comprises reacting together (A) at least one silicon containing compound having at least one silanol group; and (B) at least one silicon containing compound having at least one —OR group in the presence of (C) a calcium or magnesium catalyst selected to allow the reaction to proceed and (D) at least one solvent. Advantageous catalysts include calcium hydroxide, calcium oxide, magnesium hydroxide or magnesium oxide. Advantageously the solvent may be a protic solvent such as water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and 2-butanol. The invention also relates to condensates, such as siloxanes, prepared by the process.

대표청구항 ▼

1. A process for the preparation of an organo-silicon condensate which comprises reacting together:(A) at least one silicon containing compound having at least one silanol group; and(B) at least one silicon containing compound having at least one —OR group wherein R represents an alkyl group

1. A process for the preparation of an organo-silicon condensate which comprises reacting together:(A) at least one silicon containing compound having at least one silanol group; and(B) at least one silicon containing compound having at least one —OR group wherein R represents an alkyl group having from 1 to 8 carbon atoms, or an alkoxyalkyl group having from 2 to 8 carbon atoms in the presence of(C) a calcium or magnesium catalyst selected to allow the reaction to proceed wherein the calcium or magnesium catalyst is not calcium carbonate, calcium phosphate or magnesium carbonate; and(D) at least one protic solvent. 2. A process according to claim 1 wherein the at least one silicon containing compound having at least one silanol group and the at least one silicon containing compound having at least one —OR group are in a 1:1 molar ratio. 3. A process according to claim 1 wherein the organosilicon condensate is a siloxane. 4. A process according to claim 3 wherein the siloxane is a polysiloxane. 5. A process according to claim 1 wherein the at least one silicon containing compound having at least one silanol group is a silanol. 6. A process according to claim 5 wherein the silanol has between one and three unsubstituted or substituted hydrocarbon groups having from 1 to 18 carbon atoms. 7. A process according to claim 5 wherein the silanol has one OH group. 8. A process according to claim 5 wherein the silanol has two OH groups. 9. A process according to claim 5 wherein the silanol has three OH groups. 10. A process according to claim 5 wherein the silanol has four OH groups. 11. A process according to claim 5 wherein the silanol is diphenyl silanediol. 12. A process according to claim 5 wherein the silanol bears a crosslinkable group. 13. A process according to claim 12 wherein the crosslinkable group is a double bond. 14. A process according to claim 13 wherein the double bond is a carbon-carbon double bond. 15. A process according to claim 14 wherein the double bond is selected from an acrylate double bond, a methacrylate double bond and a styrene double bond. 16. A process according to claim 12 wherein the crosslinkable group is an epoxide. 17. A process according to claim 1 wherein the at least one silicon containing compound having at least one —OR group is a compound with the general formula y Si(OR) 4-y wherein y has a value of 0, 1, 2 or 3,G represents a unsubstituted or substituted hydrocarbon group having from 1 to 18 carbon atoms; andR represents an alkyl group having from 1 to 8 carbon atoms or an alkoxyalkyl group having from 2 to 8 carbon atoms. 18. A process according to claim 17 wherein the at least one silicon containing compound having at least one —OR group is an alkoxy silane. 19. A process according to claim 18 wherein the alkoxy silane has one alkoxy group. 20. A process according to claim 18 wherein the alkoxy silane has two alkoxy groups. 21. A process according to claim 18 wherein the alkoxy silane has three alkoxy groups. 22. A process according to claim 18 wherein the alkoxy silane has four alkoxy groups. 23. A process according to claim 17 wherein (OR) is selected from the group consisting of methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, t-butoxy. 24. A process according to claim 18 wherein the alkoxy silane bears a crosslinkable group. 25. A process according to claim 24 wherein the alkoxy silane bears a crosslinkable group on G. 26. A process according to claim 25 wherein the crosslinkable group is a double bond. 27. A process according to claim 26 wherein the double bond is a carbon-carbon double bond. 28. A process according to claim 26 wherein the crosslinkable group is a double bond selected from an acrylate double bond, a methacrylate double bond and a styrene double bond. 29. A process according to claim 25 wherein the crosslinkable group is an epoxide. 30. A process according to claim 17 wherein the alkoxy silane is a compound selected from the gr oup consisting of 3-methacryloxypropyltrimethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 1H, 1H, 2H, 2H-perfluorooctyltrimethoxysilane, octyltrimethoxysilane, 3-styrylpropyltrimethoxysilane, and 3-glycidoxypropyltrimethoxysilane, or mixtures thereof. 31. A process according to claim 1 wherein the calcium or magnesium catalyst is calcium hydroxide, calcium oxide, magnesium hydroxide or magnesium oxide. 32. A process according to claim 31 wherein the calcium or magnesium catalyst is calcium hydroxide. 33. A process according to claim 31 wherein the calcium or magnesium catalyst is calcium oxide. 34. A process according to claim 31 wherein the calcium or magnesium catalyst is magnesium hydroxide. 35. A process according to claim 31 wherein the calcium or magnesium catalyst is magnesium oxide. 36. A process according to claim 1 wherein the protic solvent is an alcohol. 37. A process according to claim 36 wherein the protic solvent is selected from the group consisting of methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and 2-butanol. 38. A process according to claim 1 wherein the protic solvent is water. 39. A process for the preparation of an organosilicon condensation product which comprises condensing at least one silicon containing compound having(a) at least one silanol group; and(b) at least one —OR groupwherein R represents an alkyl group having from 1 to 8 carbon atoms, or an alkoxyalkyl group having from 2 to 8 carbon atoms in the presence of(c) a calcium or magnesium catalyst selected to allow the reaction to proceed wherein the calcium or magnesium catalyst is not calcium carbonate, calcium phosphate or magnesium carbonate; and(d) at least one protic solvent. 40. A process according to claim 39 wherein the at least one silicon containing compound comprises both (i) a silanol-terminated polydiorganosiloxane and (ii) a polydiorganosiloxane terminated with a silanol group at one end and a triorganosiloxy group at the other. 41. A process according to claim 1 wherein the calcium or magnesium catalyst is separated from the organosilicon condensate. 42. A process according to claim 1 wherein the catalyst is employed in an amount of from 0.0005 to 5% by mole based on the total silicon containing compounds. 43. A process as claimed in claim 42 wherein the catalyst is employed in an amount of from 0.01 to 0.5% by mole based on the total silicon containing compounds. 44. A process according to claim 1 wherein the protic solvent is employed in an amount of from 0.02% to 200% by mole based on the total silicon containing compounds. 45. A process according to claim 44 wherein the protic solvent is employed in an amount of from 0.2% to 100% by mole based on the total silicon containing compounds. 46. A process according to claim 45 wherein the protic solvent is employed in an amount of 0.4 to 50% by mole based on the total silicon containing compounds. 47. A process according to claim 46 wherein the protic solvent is water employed in an amount of less than 8% by mole based on the total silicon containing compounds. 48. A process according to claim 47 wherein the protic solvent is water employed in an amount of less than 4% by mole based on the total silicon containing compounds. 49. A process as claimed in claim 1 carried out at a temperature in the range from 40° C. to 150° C. 50. A process as claimed in claim 49 carried out at a temperature in the range from 50° C. to 100° C. 51. A process according to claim 50 carried out at about 80° C. 52. A polysiloxane prepared by the method of claim 1 having an absorption of near infrared radiation at about 2820 nm of less than 15 cm −1 . 53. A polysiloxane according to claim 52 having an absorption of near infrared radiation at about 2820 nm of less than 7 cm −1 .