Patents Examined by S. C. Crossan
  • Patent number: 4957838
    Abstract: An electrophotographic photoconductor is disclosed, which comprises an electroconductive support and a photoconductive layer formed thereon comprising as an effective component at least one triphenylamine compound represented by the following formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 each represent hydrogen, an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms, or a halogen, which may be the same or different. Further, novel triphenylamine compounds for use in the electrophotographic photoconductor are disclosed.
    Type: Grant
    Filed: September 29, 1989
    Date of Patent: September 18, 1990
    Assignee: Ricoh Company, Ltd.
    Inventors: Tamotsu Aruga, Masaomi Sasaki, Tomoyuki Shimada
  • Patent number: 4957841
    Abstract: Process for specifically influencing the triboelectric effect of azo pigments in electrophotographic toners or developers or in powders for surface coating by adding to the azo pigments at the coupling reaction stage, at the laking stage or in the course of finishing at least one saltlike, cationic compound whose positively charged center is a nitrogen, phosphorus, arsenic or antimony atom or the group ##STR1## and use of such azo pigments for producing toners or developers used for the electrophotographic copying or manifolding of originals or for printing electronically, optically or magnetically stored data or in colorproofing or use of such azo pigments for producing powders or powder coatings used for the surface coating of articles made of metal, wood, plastics, glass, ceramics, concrete, textile material, paper or rubber.
    Type: Grant
    Filed: September 14, 1989
    Date of Patent: September 18, 1990
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Hans-Tobias Macholdt, Alexander Sieber, Franz Schui, Reinhold Deubel