Yellow pigments stable at high temperatures
Preparation of improved heat stable yellow iron oxide pigments
Heat resistant yellow iron oxide pigment
Yellow iron oxide pigment and method for manufacture thereof Patent #: 4459276
ApplicationNo. 06/629654 filed on 07/11/1984
US Classes:106/432, Lead compound containing, e.g., litharge, etc. (Pb)106/435, Silicon containing106/456, Iron compound containing (Fe)106/457, Silicon containing, e.g., slag, turkey umber, Fullers earth, etc.106/459With other metal compound
ExaminersPrimary: Lieberman, Paul
Assistant: Thompson, Willie J.
Attorney, Agent or Firm
International ClassesC01G 49/06 (20060101)
C01G 49/02 (20060101)
C09C 1/22 (20060101)
C09C 1/24 (20060101)
Foreign Application Priority Data1983-07-23 DE
AbstractIron oxide yellow pigments having a silking effect ƊE1 *, less than or equal to 0.5, and having color values which range for L* from 52-63, for a* from 8 to 14 and for b* from 40 to 48 CIELAB units are produced by a process by first, forming needle-shaped -FeOOH yellow pigment nuclei in the presence of compounds containing the elements B, Al, Ga, Si, Ge, Sn or Pb present in a quantity of from 0.05 to 10% by weight, where the quantity is calculated as the tri- or tetra-valent oxides of the compounds and based on the -FeOOH which is precipitated during nucleation, and second, growing iron oxide yellow pigments on the thus formed iron oxide yellow nuclei.