Electrophotographic element with a combination of binder resins
AssigneeRicoh Company, Ltd.
InventorsAkio Kozima, Eiichi Akutsu
Life of this patent
Estimating the term…
Abstract
An electrophotographic element comprising, in successive layers; a conductive substrate, a charge generation layer and a charge transport layer, the charge generation layer being formed by the steps of; adding to a dispersion comprising a photoconductive organic pigment, a solvent and a resin being superior in mutual solubility with said solvent a resinous solution comprising said solvent and a resin being relatively inferior in mutual solubility with said solvent to the former resin; dispersing (or stirring) the resulting mixture again, thereby obtaining a photoconductive organic pigment-dispersed resinous solution; and applying said resinous solution onto the conductive substrate and drying.
Claims11
In an electrophotographic element comprising an electrically conductive substrate having a charge generation layer and a charge transport layer thereon, the improvement which comprises:
- said charge generation layer consists essentially of particles of photoconductive organic pigment dispersed in a binder consisting essentially of two different resins R.sub.1 and R.sub.2 ;
- said charge generation layer having been prepared by forming a dispersion of said particles of photoconductive organic pigment in a solution of resin R.sub.1 dissolved in a solvent S for resin R.sub.1, then adding to said dispersion a solution of resin R.sub.2 dissolved in a further quantity of said solvent S and mixing same to form a coating mixture, then forming said charge generation layer from said coating mixture and then evaporating said solvent S;
- the difference between the solubility parameters of said resin R.sub.1 and said solvent S being less than about 1.0, the difference between the solubility parameters of said resin R.sub.1 and said resin R.sub.2 being in the range of from 0.2 to 2.2, and the difference between the solubility parameters of said resin R.sub.1 and said solvent S being less than the difference between the solubility parameters of said resin R.sub.2 and said solvent S.
Dependencies are inferred from the claim text.