摘要 |
Surface-modified zinc-silicon oxide particles which consist of a core, a first coating layer surrounding the core, and a second coating layer surrounding the first coating layer, where the core is crystalline and consists of aggregated zinc oxide primary particles having a primary particle diameter of from 10 to 75 nm, the first coating layer consists of one or more compounds containing the elements Zn, Si and O, the second coating layer comprises linear and/or branched alkylsilyl groups having 1 to 20 carbon atoms bonded chemically to the first coating layer, which have an average aggregate area of less than 40 000 nm2 and an average aggregate diameter (ECD) of less than 300 nm, a carbon content of from 0.4 to 1.5% by weight and a BET surface area of from 10 to 60 m2/g.
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