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US 5,690,860 AGranted
Particulate inorganic oxide treated with cyclic polysiloxane
AssigneeDow Corning Corporation
InventorGary Edward LeGrow
Life of this patent
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Abstract
The invention relates to a particulate silica or particulate titania which is treated with a cyclic polysiloxane having the formula ##STR1## in which Me represents a methyl radical and R is an alkyl group having 2 to 12 carbon atoms, The treated particles can be uniformly dispersed in a non-polar organic medium to provide a system having greater stability than similar prior art dispersions,
Claims20
A coated particulate inorganic oxide comprising:
- (A) a particulate inorganic oxide selected from the group consisting of silica, titania and mixtures thereof, said inorganic oxide being coated with
- (B) a cyclic polysiloxane having the formula ##STR8## in which Me represents a methyl radical, R is an alkyl group having 2 to 12 carbon atoms, x has an average value of 1 to 5, y has an average value of 1 to 5 and (x+y) has an average value of 4 to 6, wherein from 0.1 to 5 parts by weight of said cyclic polysiloxane (B) is used for each 100 parts by weight of said inorganic oxide (A).
A composition comprising a dispersion of
- (I) a coated particulate inorganic oxide comprising
- (A) a particulate inorganic oxide selected from the group consisting of silica;
- titania and mixtures thereof, said inorganic oxide being coated with
- (B) a cyclic polysiloxane having the formula ##STR9## in which Me represents a methyl radical, R is an alkyl group having 2 to 12 carbon atoms, x has an average value of 1 to 5, y has an average value of 1 to 5 and (x+y) has an average value of 4 to 6, wherein from 0.1 to 5 parts by weight of said cyclic polysiloxane (B) is used for each 100 parts by weight of said inorganic oxide (A), in
- (II) a non-polar organic medium.
2 more elements
A method for preparing a dispersion of a particulate inorganic oxide in a non-polar organic medium comprising
- (i) coating (A) a particulate inorganic oxide selected from the group consisting of silica, titania and mixtures thereof with (B) a cyclic polysiloxane having the formula ##STR10## in which Me represents a methyl radical, R is an alkyl group having 2 to 12 carbon atoms, x has an average value of 1 to 5, y has an average value of 1 to 5 and (x+y) has an average value of 4 to 6, wherein from 0.1 to 5 parts by weight of said cyclic polysiloxane (B) is used for each 100 parts by weight of said inorganic oxide (A), to prepare a coated particulate inorganic oxide;
- and
- (ii) uniformly dispersing said coated particulate inorganic oxide in a non-polar organic medium.
Dependencies are inferred from the claim text.