E.i. Dupont De Nemours and Company

The Chemours Company Tt, LLC

Scott Richard Mehr

John D Bolt

Robert Vincent Canning, Jr

Barry Rubin

Thomas W Simpson, Iii

Erik Shepard Thiele

Douglas Ray Stilwell

Thomas William Iii Simpson

The present invention relates to a process for making a titanium dioxide pigment consisting of titanium dioxide and single layer of inorganic surface treatment consisting of aluminum phosphate wherein the pigment is characterized by and isoelectric point which is greater than pH 6 and a negative zeta potential of at a pH of 7.5 or more.

Process for making a water dispersible titanium dioxide pigment useful in paper laminates

An automated computer-controlled method and apparatus for measuring the quality or fineness of a pigment dispersion sample, comprising placing the pigment dispersion at the deep end of the tapered path of a Hegman gage block, placing the Hegman gage block in a holder in a motorized drawdown device that draws the scraper along the length of the tapered path at an angle and to at a contact pressure and at a controlled rate, thereby creating a tapered film sample of paint whose thickness tapers from a maximum thickness of 100 micrometers to a minimum thickness of zero. An illuminator assembly illuminates the sample with a substantially collimated light source at an intensity level and the light reflected from the sample is collected by a lens onto a photodetector array in a digital camera. After a time interval the camera acquires an image of the sample. The image is digitized and stored in a memory in the computer and then a portion of the image within a region of interest corresponding to the sample in the tapered path is analyzed to detect and count pigment agglomerates that protrude above the surface of the sample.

Method and apparatus for quantifying pigment dispersion quality by paint drawdown

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Dickson, TN, United States of America

Scott Richard Mehr