Invention Grant
- Patent Title: Method for coating the surface of inorganic particles, particularly titanium dioxide pigment particles
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Application No.: US14548019Application Date: 2014-11-19
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Publication No.: US09637640B2Publication Date: 2017-05-02
- Inventor: Corinna Hommes , Jörg Friedrich , Heiko Frahm , Uwe Wilkenhoner
- Applicant: Kronos International, Inc.
- Applicant Address: DE Leverkusen
- Assignee: Kronos International, Inc.
- Current Assignee: Kronos International, Inc.
- Current Assignee Address: DE Leverkusen
- Agency: Locke Lord LLP
- Priority: EP13005849 20131217
- Main IPC: C09C1/00
- IPC: C09C1/00 ; C09C1/36 ; C09C3/06 ; C09C3/04

Abstract:
The invention relates to a method for coating the surface of inorganic solid particles in an aqueous suspension. The untreated particles, particularly TiO2 base material, are made into an aqueous suspension and subsequently disagglomerated. According to the invention, a disagglomerated suspension of untreated particles is fed (recirculated) from an intermediate vessel (vessel) in a cyclic process. The intermediate vessel contains a high-speed agitator preferably having a minimum peripheral speed of 15 m/s or a specific agitator capacity P/V of at least 30 W/m3. A pipeline mixer (e.g. inline disperser) based on the rotor/stator principle is furthermore installed in the circuit. The water-soluble precursor compounds of the coating substances, and equally any necessary pH-controlling substances, are metered into the pipeline mixer. This leads to surface coatings with greater smoothness (low specific surface area according to BET), improved density (low sulphuric-acid solubility), and less coating substance precipitated separately (improved gloss).
Public/Granted literature
- US20150166794A1 Method for Coating the Surface of Inorganic Particles, Particularly Titanium Dioxide Pigment Particles Public/Granted day:2015-06-18
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