Undercoat layer and imaging members comprising same

Abstract

Disclosed are undercoat layers comprising a metal oxide, a polymer, and a citrate of Formula (I): wherein R 1 is H, alkyl, or COR′; wherein R′ is alkyl; and wherein R 2 , R 3 , and R 4 are independently alkyl. The undercoat layers are useful in imaging members because they are easily separated from the substrate. This reduces the number of steps necessary to reclaim the substrate.

1 . An imaging member comprising an undercoat layer, the undercoat layer comprising:
 a metal oxide;   a polymer; and   a citrate of Formula (I):   
       
         
           
           
               
               
           
         
       
       wherein R 1  is H, alkyl, or COR′; wherein R′ is alkyl; and wherein R 2 , R 3 , and R 4  are independently alkyl. 
     
     
         2 . The imaging member of  claim 1 , wherein the metal oxide is a titanium oxide. 
     
     
         3 . The imaging member of  claim 1 , wherein the metal oxide is titanium dioxide or zinc oxide. 
     
     
         4 . The imaging member of  claim 1 , wherein the citrate is acetyl tributyl citrate represented by Formula (II): 
       
         
           
           
               
               
           
         
       
     
     
         5 . The imaging member of  claim 1 , wherein the citrate is tri (n-butyl)citrate represented by Formula (III): 
       
         
           
           
               
               
           
         
       
     
     
         6 . The imaging member of  claim 1 , wherein the polymer is selected from the group consisting of a phenolic resin, a melamine resin, an epoxy resin, a polyamide resin, a polyvinyl butyral resin, a polyurethane resin, a poly(vinyl carbazole), an organosilane, nylon, polyesters, polyvinylidene chloride resin, silicone resins, fluorocarbon resins, polycarbonates, polyacrylates and methacrylates, copolymers of vinyl chloride and vinyl acetate, phenoxy resins, poly(vinyl alcohol), polyacrylonitrile, polystyrene, poly(vinylbenzyl alcohol), poly(2-hydroxyethyl methacrylate), poly(2-hydroxyethyl acrylate), poly(3-hydroxypropyl methacrylate), and mixtures thereof. 
     
     
         7 . The imaging member of  claim 1 , wherein the polymer is a phenolic resin. 
     
     
         8 . The imaging member of  claim 1 , wherein the metal oxide is titanium dioxide, the polymer is a phenolic resin, and the citrate is acetyl tributyl citrate represented by Formula (II): 
       
         
           
           
               
               
           
         
       
     
     
         9 . The imaging member of  claim 1 , wherein the metal oxide is titanium dioxide, the polymer is a phenolic resin, and the citrate is tri(n-butyl)citrate represented by Formula (III): 
       
         
           
           
               
               
           
         
       
     
     
         10 . An imaging member comprising, in sequence:
 a substrate;   an undercoat layer; and   a photosensitive layer;   wherein the undercoat layer is formed from a dispersion comprising a metal oxide, a polymer, and a citrate of Formula (I):   
       
         
           
           
               
               
           
         
       
       wherein R 1  is H, alkyl, or COR′; wherein R′ is alkyl; and wherein R 2 , R 3 , and R 4  are independently alkyl. 
     
     
         11 . The imaging member of  claim 10 , wherein the metal oxide is titanium dioxide. 
     
     
         12 . The imaging member of  claim 10 , wherein the polymer is selected from the group consisting of a phenolic resin, a melamine resin, an epoxy resin, a polyamide resin, a polyvinyl butyral resin, a polyurethane resin, a poly(vinyl carbazole), an organosilane, nylon, polyesters, polyvinylidene chloride resin, silicone resins, fluorocarbon resins, polycarbonates, polyacrylates and methacrylates, copolymers of vinyl chloride and vinyl acetate, phenoxy resins, poly(vinyl alcohol), polyacrylonitrile, polystyrene, poly(vinylbenzyl alcohol), poly(2-hydroxyethyl methacrylate), poly(2-hydroxyethyl acrylate), poly(3-hydroxypropyl methacrylate), and mixtures thereof. 
     
     
         13 . The imaging member of  claim 10 , wherein the polymer is a phenolic resin. 
     
     
         14 . The imaging member of  claim 10 , wherein the citrate comprises from about 0.1 to about 30 weight percent of the undercoat layer. 
     
     
         15 . The imaging member of  claim 10 , wherein the metal oxide is titanium dioxide, the polymer is a phenolic resin, and the citrate is acetyl tributyl citrate represented by Formula (II): 
       
         
           
           
               
               
           
         
       
     
     
         16 . The imaging member of  claim 10 , wherein the metal oxide is titanium dioxide, the polymer is a phenolic resin, and the citrate is tri(n-butyl)citrate represented by Formula (III): 
       
         
           
           
               
               
           
         
       
     
     
         17 . A method for reclaiming a substrate from an imaging member, comprising:
 providing an imaging member comprising a substrate and an undercoat layer, the undercoat layer comprising a metal oxide, a polymer, and a citrate of Formula (I):   
       
         
           
           
               
               
           
         
       
       wherein R 1  is H, alkyl, or COR′; wherein R′ is alkyl; and wherein R 2 , R 3 , and R 4  are independently alkyl; and
 immersing the imaging member in a stripping solution to separate the undercoat layer from the substrate. 
 
     
     
         18 . The method of  claim 17 , wherein the stripping solution comprises a solvent selected from the group consisting of N-methylpyrrolidone, ethanol, dimethylsulfoxide, N,N′-dimethylformamide, N,N′-dimethylacetamide, and mixtures thereof. 
     
     
         19 . The method of  claim 17 , wherein the stripping solution comprises an acid selected from the group consisting of citric acid, acetic acid, nitric acid, oxalic acid, phosphoric acid, hydrochloric acid, sulfuric acid, and mixtures thereof. 
     
     
         20 . The method of  claim 17 , wherein the imaging member further comprises a charge generating layer and a charge transport layer.