Process for the preparation of large scrubbing aggregates of titanium dioxide particles by the vapour phase oxidation of titanium tetrachloride, and its use in the prevention of scale formation in the same process

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Listed from its EPO record in Patent Yard's archive of European patents past their term. Its claims, description and drawings are in the EPO PDF and on Google Patents, and the Claude kit works from them.

Why it's free to use

• Filed October 31, 1986 and granted February 21, 1990. A European patent lasts at most 20 years from filing, so its term ended October 31, 2006.
• A supplementary protection certificate, which can extend a medicine or crop-protection patent, adds at most five and a half years, so even that would have ended by May 1, 2012.
• We check European rights only. A US or other national patent in its family could still be in force: check its family on Espacenet or Google Patents.