Pyrylium-sensitized leuco base photoconductive compositions and elements containing naphthalene bis-dicarboximide compounds

Claim 2

A photoconductive composition comprising at least one arylalkane leuco base photoconductor, a 4-aminobenzo[b]pyrylium or 4-aminobenzo[b]-thiopyrylium sensitizer and a 1,4,5,8-naphthalene bis-dicarboximide compound in effective amounts to reduce the leuco base color shift of said composition, said naphthalene bis-dicarboximide having the structure: ##STR8## wherein: R 1 and R 2 , which may be the same or different, represent aryl, or aryl substituted with alkyl, alkoxy, perfluoroalkyl or perfluoroalkoxy groups having 2 to 20 alkyl carbon atoms; sulfonyl; sulfone; sulfonamide; nitrile; or nitro groups; R 3 , R 4 , R 5 and R 6 , which may be the same or different, represent hydrogen, alkyl having 1 to 4 carbon atoms, alkoxy having 1 to 4 carbon atoms, or halogen; and n is 0 to 3.

Claim 3

A composition as in claim 1 wherein said dicarboximide compound is selected from the group consisting of N,N'-bis[p-(n-butyl)phenyl]-1,4,5,8-naphthalene bis-dicarboximide, N,N'-bis(m-trifluoromethylphenyl)-1,4,5,8-naphthalene bis-dicarboximide, N,N'-bis(3-phenylpropyl)-1,4,5,8-naphthalene bis-dicarboximide and N,N'-bis[p-(n-octyloxy)phenyl]1,4,5,8-naphthalene bis-dicarboximide.

Claim 4

A composition as in claims 1 or 2 wherein the concentration of said dicarboximide compound is at least 1 percent by weight of said composition on a solvent-free basis.

Claim 5

A composition as in claim 1 wherein said leuco base photoconductor has the structure: ##STR9## wherein: each of R and R' is selected from the group consisting of hydrogen, alkyl and aralkyl having 2 to 4 carbon atoms in the alkyl group; each of X' and X" is selected from the group consisting of alkyl having 1 to 4 carbon atoms, alkoxy having 1 to 4 carbon atoms, hydroxyl and halogen; each of Y' and Y" is selected from the group consisting of alkyl having 1 to 4 carbon atoms, alkoxy having 1 to 4 carbon atoms, hydroxyl, halogen and hydrogen; and each of A and B is: (1) hydrogen, with the proviso that A and B are not both hydrogen; (2) aryl and substituted derivatives thereof wherein the substituent is dialkylamino, alkylamino, amino, alkyl, alkoxy, hydroxyl or halogen; (3) an aliphatic alkyl group having 1-18 carbon atoms; (4) a cycloalkyl group having 4-8 carbon atoms in the cyclic nucleus; or (5) a cycloalkenyl group having 4-8 carbon atoms in the cyclic nucleus; and said sensitizer has the structure: ##STR10## wherein: X is sulfur or oxygen; Z is an anion such as perchlorate, fluoroborate, sulfonate, periodate or p-toluenesulfonate; R is alkyl having from 1 to 10 carbon atoms or aryl; R 1 is hydrogen, alkyl having 1 to 4 carbon atoms, or alkoxy having 1 to 4 carbon atoms; each of R 2 and R 3 , when taken separately, represents a hydrogen atom and, when taken together, is attached to adjacent carbon atoms and represents the atoms necesary to form a fused aromatic ring such as a benzo ring.

Claim 6

A composition as in claim 4 comprising the three leuco base photoconductors bis(4-N,N-diethylamino-2-methylphenyl)-4-methylphenylmethane, 1,1-bis(4-N,N-diethylamino-2-methylphenyl)-2-methylpropane and 4,4'-bis(diethylamino)-2,2'-dimethyltriphenylmethane.

Claim 7

A composition as in claim 5 wherein said sensitizer is 4-[N-butylamino]-2-p-methoxyphenyl)benzo[b]pyrylium tetrafluoroborate and said dicarboximide is N,N-bis[p-(n-butyl)phenyl]-1,4,5,8-naphthalene bis di-carboximide.

Claim 8

A photoconductive element comprising an electrically conducting support and a layer of the photoconductive composition of claims 1, 2, 3, 4, 5 or 6 overlying said support.