Pseudobrookite pigments

25 US 4036662 Rademachers Bayer PBrookite Metal Additions to Pigments of Pseudobrookite-Titanium Dioxide Stmcture 07/19/77 

26 US 4084984 Hund Bayer PBrookite Temperature-Stable Inorganic Yellow Pigments 04/18/78 

27 EP 949202 Katamoto Toda Kogyo PBrookite Heat Resistant Yellow Pigment 10/13/99 

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There are at least two pseudobrookite pigment chemistries in products in the marketplace. The first uses a large excess of Ti02 to help force complete reaction of the Fe203. This results in a rutile secondary phase that is sometimes the dominant phase in the product. In fact, patents cover such composition with up to a 15 fold excess of Ti02 ... 

Titanate Pigments Colored Rutile, Priderite, and Pseudobrookite Structured Pigments... 

The family of titanate pigments are listed below in Tables 6-1 and 6-2 according to their listing in the DCMA handbook. They fall into three crystal classes rutile, priderite, and pseudobrookite. Note that the Fe(III) pseudobrookite (Fc2Ti05) pigments were incorrectly categorized in the DCMA Handbook, as well as in company product literature, as FeTi-spinels. The spinel formula, Fc2Ti04, would require them to be Fe species instead of Fe species. 

Pseudobrookite, Fe2TiOs, is a stable structure that has even been observed as a decomposition product of overfired ZnFeTi spinel pigments. Despite this, it is difficult to make dean versions of this pigment. 

I 6 Titanate Pigments Colored Rutile, Priderite, and Pseudobrookite Structured Pigments Table 6.6 Lattice parameter changes (vs. pureTiOj) in DR pigments. 

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