Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G9/00—Developers
  • G03G9/08—Developers with toner particles
  • G03G9/087—Binders for toner particles
  • G03G9/08702—Binders for toner particles comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • G03G9/08735—Polymers of unsaturated cyclic compounds having no unsaturated aliphatic groups in a side-chain, e.g. coumarone-indene resins
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G13/00—Electrographic processes using a charge pattern
  • G03G13/22—Processes involving a combination of more than one step according to groups G03G13/02 - G03G13/20
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
  • G03G5/02—Charge-receiving layers
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
  • G03G5/02—Charge-receiving layers
  • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
  • G03G5/06—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being organic
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
  • G03G5/02—Charge-receiving layers
  • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
  • G03G5/06—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being organic
  • G03G5/07—Polymeric photoconductive materials
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G9/00—Developers
  • G03G9/08—Developers with toner particles
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G9/00—Developers
  • G03G9/08—Developers with toner particles
  • G03G9/087—Binders for toner particles
  • G03G9/08702—Binders for toner particles comprising macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • G03G9/08706—Polymers of alkenyl-aromatic compounds
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G9/00—Developers
  • G03G9/08—Developers with toner particles
  • G03G9/087—Binders for toner particles
  • G03G9/08742—Binders for toner particles comprising macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • G03G9/08746—Condensation polymers of aldehydes or ketones
  • G03G9/08748—Phenoplasts
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G9/00—Developers
  • G03G9/08—Developers with toner particles
  • G03G9/087—Binders for toner particles
  • G03G9/08775—Natural macromolecular compounds or derivatives thereof

Definitions

• a method for making electrophotographic reproductions which comprises the first step of forming an electrostatic latent image on an organic photoconductive layer which includes component materials of substantially equal reflective indices, and which includes light scattering inner surfaces homogeneously throughout its thickness or near the surface of the layer whereby the layer has an opaque appearance.
• the latent image is then developed according to any of the known electrophotographic development procedures, thus converting the latent image into a toner image, which decreases the light-scattering property of the organic photoconductive layer when impregnated into the layer.
• the toner deposited area of the layer is then made more transparent than the remaining areas by the action of heat and/or a solvent for the toner.
• This invention relates to a new electrophotographic process utilizing organic photoconductors.
• Organic photoconductors which include polymerized materials having film-forming property by themselves and low molecular weight ones capable of forming solid solutions with other film-forming materials can provide very attractive recording materials in which the recording layer is optically transparent.
• an organic photoconductive transparent layer is formed on a suitable transparent or semi-transparent support such as cellophane, moisture-proof cellophane, tracing paper, various plastic films having thereon a conductive sub-coating, etc.
• a suitable transparent or semi-transparent support such as cellophane, moisture-proof cellophane, tracing paper, various plastic films having thereon a conductive sub-coating, etc.
• the resulting material is conveniently used to produce electrophotographically a transparency, which is quite useful as a lantern slide for projection, a master for an overhead projector, or for contact printing material such as diazo paper or diazo film.
• the present process is such as to provide a negative transparency utilizing organic photoconductive layers specially prepared.
• the present invention comprises; forming an electrostatic latent image on an organic photoconductive layer which comprises components of substantially equal refractive indices, and which includes light scattering inner surfaces homogeneously dispersed throughout its thickness or near the surface of the layer, thus having an opaque appearance, developing said latent image according to any of known electrophotographic development procedures, thus converting the image into a toner image, said toner image being capable of decreasing the lightscattering property of said layer when impregnated into said layer, and then making the toner deposited area of the layer more transparent than the remaining areas.
• the organic photoconductive layer which comprises components of substantially equal refractive indices comprises either a single transparent component or plural components of nearly equal refractive indices.
• the toner image comprises resins or organic compounds capable of melting or dissolving by heat or solvent and having refractive indices nearly equal to that of the photoconductive layer.
• incorporación of an ingredient not perfectly compatible with the organic photoconductor results in an opaque dry film.
• the degree of opacity can be controlled by selecting the solvent composition and drying conditions. This method is suited for an organic photoconductive polymer having a film-forming property by itself in which case the incompatible ingredient may be a polymer plasticizer or thermoplastic polymeric material which can form a clear or homogeneous solution with the photoconductive polymer. With such combinations, formation of light-scattering microscopic inner surfaces proceeds along with the evaporation of the coating solvent.
• Another typical method is to utilize the socalled phenomenon blushing by employing a solvent system containing a water-miscible, highly volatile solvent such as lower alkyl alcohols, or ketones, coating the coating mixture and carrying out drying of the mixture in a relatively humid atmosphere whereby the moisture condenses onto the coated liquid film due to the heat of evaporation of the rapidly evaporating solvent, causing a phase separation of the film-forming material.
• a solvent system containing a water-miscible, highly volatile solvent such as lower alkyl alcohols, or ketones
• Still other methods to provide a light-scattering, opaque recording layer are as follows:
• a photoconductive binder may be used.
• a non-photoconductive crystalline compound and a photoconductive polymeric binder may be used.
• Light-scattering structure may be introduced only at the surface portion of the coating.
• the following procedure may be employed; An organic photoconductive coating is formed in a transparent dried form by an ordinary manner, then on the coating is applied a uniformly small amount of solvent which are described in (ii), and again dried.
• the surface portion in which the solvent penetrated becomes to include light-scattering inner surfaces.
• a light-scattering photoconductive coating obtained by any of the above-described methods is processed according to known electrophotographic operations; in case of the Carlson process, the coating is uniformly charged under subdued light, exposed to an optical image to provide an electrostatic latent image and then developed by applying a toner to convert said latent image into a visible one and finally a toner image is obtained on such coating.
• Any other processes than Carlson method which utilize the photoconductivity of the coating and produce a toner image are all applicable for the present invention.
• thermoplastic, transparent, finely-divided resinous material is especially adapted for the toner of the present invention.
• suitable solvents having a low boiling point or which have relatively low melting points are most preferred, since the present method requires the toner to easily permeate into the recording layer in order to diminish the inner surfaces.
• toner materials which become fiowable or mobile upon heating or can dissolve in a solvent are especially preferred.
• suitable materials include polystyrene, poly(amethyl styrene), styrene copolymers, cumarone-indene resin, petroleum resin, phenol-formaldehyde resin, rosin and its derivatives, xylene-formaldehyde resin, etc.
• toner such as vinyl polymers, or cellulose derivatives, which are difiicult to damage mechanically.
• Permeation of the toner into the recording layer can be promoted by heating the layer to a point higher than the melting point of the toner.
• the softening point of the layer must be sufficiently higher than that of the toner used.
• Another preferable method of promoting toner permeation is to subject the developed material to a solvent vapor which dissolves the toner but exerts no effect on the layer. This method is considered better than the former since the viscosity of the dissolved toner becomes quite low so that it can permeate into the layer very quickly.
• Images obtained by the present method on transparent supports can be used as lantern slide or projection film for projectors, and those on colored opaque supports appear positive with the exposed color of the supports.
• the present method is carried out with a material comprising a support having highly light-reflective surface and a recording coating provided on said surface, the toner-deposited area looks brilliant by light reflection from the exposed support surface against dark background.
• EXAMPLE 1 67 parts by weight of polyvinylcarbazole and 33 parts by weight (hereinafter part will always be given by Weight when otherwise mentioned) of a polyester type polymer plasticizer :Plasticizer P.N. from Daihachi Chemical Industries were dissolved in a suitable amount of benzene. The resulting solution was coated on the metallized side of polyethylene-terephthalate film purchased from Toyo Rayon under the trade name Metalmy having a thickness of 90 microns. The coating and drying was carried out under an atmosphere of 50% R.I-I. During drying the two components which are substantially incompatible with each other were separated to form a White opaque coating. The dry thickness of the coating was about 8 microns.
• the member was uniformly electrostatically charged in subdued room light to a positive polarity.
• the uniformly charged member was then projected a light image transmitting a negative image on a microfilm to produce an electrostatic latent image, and immediately thereafter developed with a cascade developer comprising nitrocellulose coated glass beads and a finelydivided powder of a petroleum hydrocarbon resin having a melting point of C. Since this powder was triboelectrically charged positive in the mixture, the so-called reversal development occurred.
• the member bearing the toner image was left in a closed vessel saturated with acetone vapor for a few minutes. Then the coating became clear at the toner-deposited area exposing the reflective gray color of aluminum underlying the coating.
• the thus produced image was irradiated by light, and the reflected light was focused on an opaque screen on which appeared an image comprising brighter image areas and a dark background.
• EXAMPLE 2 50 parts of N-vinylcarbazol and 50 parts of polystyrene were dissolved in benzene. The solution was applied on a subbed surface of polyethyleneterephthalate film. The sub-coating was transparent and electroconductive. During evaporation of solvent crystallization of vinylcarbazol proceeded to give an opaque coating with micron dry thickness. The dried film was positively charged and exposed to a photographic positive with line image to form an electrostatic latent image.
• a cascade developer comprising ethylcellulose coated natural silica sand and finely-divided rosin which assumed a negative charge was used as developer and a positive reproduction of the original image resulted.
• An electrostatic latent image obtained by uniform charging and image exposure was visualized by magnetic brush development utilizing low melting point petroleum resin (melting point 70 C.) Heating of the developed member to 80 C. caused the toner-deposited area to change transparent.
• EXAMPLE 4 An electrostatic latent image of positive polarity was formed on the member prepared in Example 2, and developed by a liquid developer comprising isoparafiinic carrier liquid and finely-divided polyvinylacetate dispersed in said liquid. Since this toner charged positive socalled reversal development took place. Exposure of the developed member to methanol vapor resulted in clearing of the toner-deposited area.
• An electrophotographic method comprising electrophotographically forming a toner image on an organic photoconductive layer which consists essentially of at least one ingredient of a first refractive index and which includes light-scattering surfaces within the layer uniformly dispersed throughout the total thickness of the layer or near the surface portion of the layer, permeating said toner material which consists essentially of a transparent material which has a refractive index substantially equal to said first refractive index into said layer by the action of heat and/ or solvent for said toner and thus decreasing the opacity of the layer only at the toner-deposited area.
• said toner material is polystyrene, poly(a-methyl styrene), styrene copolymers, cumarone-indene resin, petroleum resin, phenol-formaldehyde resin, rosin or its derivatives or xylene-formaldehyde resin.
• said organic photoconductive layer comprises at least two ingredients, each having a refractive index substantially equal to that of said first refractive index.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Photoreceptors In Electrophotography (AREA)
• Developing Agents For Electrophotography (AREA)
• Combination Of More Than One Step In Electrophotography (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=13187926

Family Applications (1)

Country Status (7)

Cited By (3)

• 0
  • BE BE754544D patent/BE754544A/fr unknown
• 1969
  • 1969-08-07 JP JP44062016A patent/JPS4821054B1/ja active Pending
• 1970
  • 1970-07-31 US US60116A patent/US3704119A/en not_active Expired - Lifetime
  • 1970-08-03 FR FR7028556A patent/FR2056499A5/fr not_active Expired
  • 1970-08-05 CA CA089,941A patent/CA949796A/en not_active Expired
  • 1970-08-06 GB GB3804170A patent/GB1321065A/en not_active Expired
  • 1970-08-07 NL NL7011700A patent/NL7011700A/xx unknown

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