Functionalized silica particle and use thereof for cross-linking silicones
AssigneeTemple University-Of The Common Commonwealth System of Higher Education
InventorsMark A. Buese, Dana L. Poczynok
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Abstract
Particulate fillers containing Si-OH groups are functionalized by treatment with a silica bonding agent. The treated particles are effectively polyfunctional, and may be used to prepare highly filled, cross-linked organopolysiloxane networks without the need for additional cross-linking agents. The functionalized particles are highly compatible with silicone fluids, particularly cyclosiloxane fluids. Compositions curable to such filled, cross-linked networks comprise the bonding agent-functionalized particles, a curable organopolysiloxane, and a catalyst for curing the organopolysiloxane.
Claims11
A process for preparing a polyfunctionalized filler comprising
- treating a silanol-containing filler with a bonding agent comprising one or more compounds according to the formula ##STR10## wherein X is chlorine, bromine, or iodine;
- the group --OR wherein R is C.sub.1 to C.sub.8 straight- or branched-chain alkyl or aryl, preferably C.sub.1 to C.sub.4 alkyl;
- the group ##STR11## wherein R.sup.1 is selected from the group consisting of hydrogen and C.sub.1 to C.sub.6 straight- or branched-chain alkyl, or
- R.sup.1 forms, together with the carbonyl carbon and nitrogen of said group, a ring containing from five to seven carbon atoms;
- the group ##STR12## wherein R.sup.2 and R.sup.3, same or different, are selected from the group consisting of hydrogen and C.sub.1 to C.sub.6 straight- or branched-chain alkyl, or
- R.sup.2 forms, together with the carbonyl carbon and nitrogen of said group, a ring containing from five to seven atoms, and R.sup.3 is C.sub.1 to C.sub.6 straight- or branched-chain alkyl;
- the group --NR.sup.4 R.sup.5 wherein
- R.sup.4 and R.sup.5 same or different, are selected from the group consisting of hydrogen and C.sub.1 to C.sub.8 straight- or branched-chain alkyl or aryl;
- or
- the group ##STR13## wherein R.sup.7 is C.sub.1 to C.sub.8 straight- or branched-chain alkyl or aryl;
- to convert at least a portion of the silanol groups on the filler to a moiety of the formula ##STR14## and recovering the polyfunctionalized filler.
Polyfunctional filler particle comprising a silanol-containing filler particle at least a portion of the available silanol groups of which have been converted to a moiety of the formula ##STR15##
Dependencies are inferred from the claim text.