Patent ID: 11884797
Assignee: B.G. NEGEV TECHNOLOGIES AND APPLICATIONS LTD., AT BEN-GURION UNIVERSITY
Field: Macromolecular chemistry, polymers (Chemistry)
Classification: CPC C | IPC C

Claim 0:
1. A process of preparing an ultraviolet light absorber additive for protecting polymers from ultraviolet radiation, comprising providing silica particles having silanol groups (SiOH) on their surface;
reacting the silanol groups with a vinyl compound of the formula (H2C═CH)iSi(OCjH2j+1)4−i wherein 1≤i≤3 and 1≤j≤3, thereby covalently attaching the vinyl compound to the silica surface via the surface silanol groups, thereby introducing onto the surface of the silica particles a first functional group which is a carbon-carbon double bond, reacting the so-formed inorganic oxide particles modified with the carbon-carbon double bond group with a spacer having a plurality of a second functional group,
wherein the spacer is an organosilicon compound having silicon hydride (SiH) functional groups, wherein the number of SiH groups in the organosilicon compound is denoted by n, where n is an integer equal to or greater than 4, wherein one SiH group participates in a bond formation reaction with the carbon-carbon double bond group present on the surface of the silica particles, thus having n−1 SiH groups available for bond formation reaction with a UV light absorbing compounds; reacting the so-formed particles having n−1 SiH groups available for bond formation reaction, with a UV light absorbing compound; and isolating from the reaction mixture said ultraviolet light absorber additive.