Persistent photoconductive compositions

Claim 2

AN ELECTROSTATOGRAPHIC IMAGING METHOD WHICH COMPRISES THE STEPS OF: A. PROVIDING AN IMAGING MEMBER HAVING A PHOTOCONDUCTIVE IMAGING LAYER COMPRISING AN ORGANIC PHOTOCONDUCTIVE MATERIAL, AN ACTIVATOR CAPABLE OF FORMATION OF A CHARGE TRANSFER COMPLEX WITH SAID PHOTOCONDUCTIVE MATERIAL, AND A PROTONIC ACID, SAID ACID BEING PRESENT IN SUFFICIENT CONCENTRATION IN RELATION TO THE ACTIVATOR TO ENHANCE THE STABILITY OF A COMPLEX FORMED DURING ILLUMINATION BETWEEN THE ANION RADICAL FORM OF THE ACTIVATOR AND A PROTON AND THUS EXTEND THE ELEVATED LEVEL OF CONDUCTIVITY OF THE PHOTOCONDUCTIVE IMAGING LAYER SUBSEQUENT TO THE ILLUMINATION THEREFOR; B. ILLUMINATING THE IMAGING LAYER IN IMAGE CONFIGURATION FOR AN INTERVAL SUFFICIENT TO GENERATE A PHOTOINDUCED STATE OF ELEVATED CONDUCTIVITY WITHIN SAID IMAGING SURFACE IN THE LIGHT STRUCK AREAS WHICH PERSISTS SUBSEQUENT TO ILLUMINATION; C. FORMING A LATENT ELECTROSTATIC IMAGE ON THE IMAGING LAYER BY CHARGING SAID LAYER IN THE DARK;

Claim 3

An electrostatographic imaging method which comprises the steps of: a. providing an imaging member having a photoconductive imaging layer comprising an organic photoconductive material, an activator capable of formation of a charge transfer complex with said photoconductive material, and a protonic acid, said acid being present in sufficient concentration in relation to the activator to enhance the stability of a complex formed during illumination between the anion radical form of the activator and a proton and thus extend the elevated level of conductivity of the photoconductive imaging layer subsequent to the illumination thereof; b. illuminating the imaging layer in image configuration for an interval sufficient to generate a photoinduced state of elevated conductivity within said imaging surface in the light struck areas which persists subsequent to illumination; c. forming a latent electrostatic image on the imaging layer by charging said layer in the dark;

Claim 4

An electrostatographic imaging method which comprises the steps of: a. providing an imaging member having a photoconductive imaging layer comprising an organic photoconductive material, an activator capable of formation of a charge transfer complex with said photoconductive material, and a protonic acid, said acid being present in sufficient concentration in relation to the activator to enhance the stability of a complex formed during illumination between the anion radical form of the activator and a proton and thus extend the elevated level of conductivity of the photoconductive imaging layer subsequent to the illumination thereof; b. illuminating the imaging layer in image configuration for an interval sufficient to generate a photoinduced state of elevated conductivity within said imaging surface in the light struck areas which persists subsequent to illumination; c. forming a latent electrostatic image on the imaging layer by charging said layer in the dark;

Claim 5

The electrostatographic imaging method of claim 1, wherein the latent electrostatic image is rendered visible by development with colored electroscopic toner particles.

Claim 6

The electrostatographic imaging method of claim 1, wherein the latent electrostatic image is transferred from the surface of the imaging layer to a transfer sheet and then developed.

Claim 7

The electrostatographic imaging method of claim 1, wherein the imaging layer is restored to its relatively insulative state by the additional steps of d. dissipating the latent electrostatic image by uniformly illuminating the imaging layer; and e. subjecting the imaging layer to a temperature of about 50* to about 150*C for an interval sufficient to restore it to its former insulative condition.

Claim 8

The electrostatographic imaging method of claim 4 wherein steps (a) through (e) are repeated in sequence at least one additional time.

Claim 9

The electrostatographic imaging method of claim 1, wherein the photoconductive imaging layer contains a 1:1 weight ratio of activator to protonic acid.

Claim 10

The electrostatographic imaging method of claim 1 wherein from photoconductive imaging layer contains structural units form the monomer, N-vinyl-carbazole.

Claim 11

The electrostatographic imaging method of claim 1, wherein the activator is o-dinitrobenzene.

Claim 12

The electrostatographic imaging method of claim 1 wherein the activator is 2,4,7-trinitro-9-fluorenone.

Claim 13

An electrostatographic imaging method which comprises the steps of: a. providing an imaging member having a photoconductive imaging layer comprising an organic photoconductive material, an activator capable of formation of a charge transfer complex with said photoconductive material and a protonic acid selected from the group consisting of napthalenesulfonic acid, benzosulfonic acid, o-aminobenzosulfonic acid, p-aminobenzosulfonic acid, m-aminobenzosulfonic acid, iodoacetic acid, bromoacetic acid, dichloroacetic acid, trichloroacetic acid, dichloroacetylacetic acid, dimethylmalonic acid, dinicotinic acid, fluorobenzoic acid, o-hydroxybenzoic acid, lutidinic acid, maleic acid, malonic acid, oxalic acid, quinolinic acid Alpha -tartaric acid, phosphoric acid and sulfurous acid, said acid being present in sufficient concentration in relation to the activator to enhance the stability of a complex formed during illumination between the anion radical form of the activator and a proton and thus extend the elevated level of conductivity of the photoconductive imaging layer in the illuminated areas subsequent to the illumination thereof; b. illuminating the imaging layer in imagewise configuration for an intErval sufficient to generate a photoinduced state of elevated conductivity within said imaging layer in the illuminated areas, the level of illumination being sufficient to cause said photoinduced state of elevated conductivity to persist subsequent to such illumination; and c. forming a latent electrostatic image on the imaging layer by charging said layer in the dark.

Claim 14

An electrostatographic imaging method which comprises the steps of: a. providing an imaging member having a photoconductive imaging layer comprising an organic photoconductive material, an activator capable of formation of a charge transfer complex with said photoconductive material and a protonic acid selected from the group consisting of napthalenesulfonic acid, benzosulfonic acid, o-aminobenzosulfonic acid, p-aminobenzosulfonic acid, m-aminobenzosulfonic acid, iodoacetic acid, bromoacetic acid, dichloroacetic acid, trichloroacetic acid, dichloroacetylacetic acid, dimethylmalonic acid, dinicotinic acid, fluorobenzoic acid, o-hydroxybenzoic acid, lutidinic acid, maleic acid, malonic acid, oxalic acid, quinolinic acid Alpha -tartaric acid, phosphoric acid and sulfurous acid, said acid being present in sufficient concentration in relation to the activator to enhance the stability of a complex formed during illumination between the anion radical form of the activator and a proton and thus extend the elevated level of conductivity of the photoconductive imaging layer in the illuminated areas subsequent to the illumination thereof; b. illuminating the imaging layer in imagewise configuration for an intErval sufficient to generate a photoinduced state of elevated conductivity within said imaging layer in the illuminated areas, the level of illumination being sufficient to cause said photoinduced state of elevated conductivity to persist subsequent to such illumination; and c. forming a latent electrostatic image on the imaging layer by charging said layer in the dark.

Claim 15

The electrostatic imaging method of claim 10, wherein the photoconductive imaging layer contains from about 0.1 to about 4 weight percent protonic acid.

Claim 16

The electrostatographic imaging method of claim 10, wherein the latent electrostatic image is rendered visible by development with colored electroscopic toner particles.

Claim 17

The electrostatographic imaging method of claim 10, wherein the latent electrostatic image is transferred from the surface of the imaging layer to a transfer sheet and then developed.

Claim 18

The electrostatographic imaging method of claim 10, wherein the imaging layer is restored to its relatively insulative state by the additional steps of d. dissipating the latent electrostatic image by uniformly illuminating the imaging layer; and e. subjecting the imaging layer to a temperature of about 50* to about 150*C for an interval sufficient to restore it to its former insulating condition.

Claim 19

The electrostatographic imaging method of claim 14, wherein steps (a) through (e) are repeated in sequence at least one additional time.

Claim 20

The electrostatographic imaging method of claim 10, wherein the photoconductive imaging layer contains a 1:1 weight ratio of activator to protonic acid.

Claim 21

The electrostatographic imaging method of claim 10, wherein the photoconductive imaging layer contains structural units from the monomer, N-vinylcarbazole.

Claim 22

The electrostatographic imaging method of claim 10, wherein the activator is o-dinitrobenzene.