Titanium dioxide finishing process

Compositions: coating or plastic – Materials or ingredients – Pigment – filler – or aggregate compositions – e.g. – stone,...

Reexamination Certificate

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Details

C106S436000, C423S610000, C423S611000, C423S612000

Reexamination Certificate

active

11263702

ABSTRACT:
This disclosure relates to process for producing titanium dioxide (TiO2) pigments, comprising the following steps: a) oxidizing a mixture of titanium tetrahalide and a rutile forming agent, such as aluminum halide, present in the vapor phase and in the presence of a nucleant to form a gaseous suspension comprising titanium dioxide particles; b) passing the gaseous suspension to a cooling conduit; c) introducing scouring material into the cooling conduit; wherein the particles of the scouring material have a diameter in the range of about 0.25 mm to about 12.7 mm; d) separating the vapor phase to form a powder comprising the titanium dioxide particles and the scouring material; and e) simultaneously subjecting the powder to substantially uniform heating at a temperature of about 300° C. to about 600° C. and reducing the size of the titanium dioxide particles and the particles of the scouring material in the powder to a mean particle size of about 50 nm to about 1000 nm, whereby the titanium dioxide pigment has a chloride content of less than about 500 ppm. The so treated powder may have a residual free chlorine content of less than about 1 ppm.

REFERENCES:
patent: 2488439 (1949-11-01), Schaumann
patent: 2721628 (1955-10-01), Rick
patent: 2899278 (1959-08-01), Lewis
patent: 3208866 (1965-09-01), Lewis et al.
patent: 3511308 (1970-05-01), Nerlinger
patent: 3726464 (1973-04-01), Schurr
patent: 4083946 (1978-04-01), Schurr et al.
patent: 4222789 (1980-09-01), Jacobson
patent: 4462979 (1984-07-01), Stevens et al.
patent: 4569387 (1986-02-01), Hartmann et al.
patent: 4784841 (1988-11-01), Hartmann et al.
patent: 4937064 (1990-06-01), Gonzalez
patent: 5024827 (1991-06-01), Jones et al.
patent: 5201949 (1993-04-01), Allen et al.
patent: 5266108 (1993-11-01), Hauck
patent: 5728205 (1998-03-01), Allen et al.
patent: 5833892 (1998-11-01), Gurav et al.
patent: 6145765 (2000-11-01), Capelle, Jr. et al.
patent: 6419893 (2002-07-01), Yuill et al.
patent: 6562314 (2003-05-01), Akhtar et al.
patent: 2005/0214200 (2005-09-01), Surender et al.
patent: 2276157 (1994-09-01), None

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