IL24632A - Xerographic plate and method - Google Patents

Description

PATENTS AND DESIGNS ORDINANCE SPECIFICATIO Π¾*2>1 I (we) RmK imO -IKiliSD, a British Company, of 37/41 Korimer Street, London, Bngland do hereby declare 'the. nature of this invention and in what manner' the same is to be performed, to be particularly described and ascertained" in and by the following statement:- This invention relates in general to xerographic imaging and more specifically, to a photosensitive plate and method for its use therein.

In xerography, as first described in U. S. Patent 2,2 ,6 1* a latent electrostatic image is generally formed on a photoconductive insulator by the combined action of light and an electrical field and is developed through the deposition thereon of finely divided electroscopic materials. These electroscopic materials, which are known in the art as toners, are selected for use in the more conventional xerographic systems so that they will adhere to the latent electrostatic image on a photoconducting insulating layer, thereby rendering the original latent image visible. In most Instances, the developed toner image is. then either fixed in place on the surface of the photoconductive insulating layer or transferred to a copy sheet for fixing thereon, with the selection, for the most part, depending upon whether or not the, photoconduc ive insulating layer is immediately reusable in . the process. In other forms of xerography, the plate is not precharged but is first exposed and then developed with a biased developer, as in U. S. Patent 2,956,847. For purposes of the description of this invention, xerography may be defined as any imaging technique including a step in which exposure to a pattern of electromagnetic radiation, such as light, is employed to modify the electrical properties f a photosensitive "plate" in a corresponding patterned configuration.

Although other xerographic plate structures are known, the two I types of xerographic plates in widest commercial use today, are the amorphous selenium plate and the pigmen binder Blxby, may be concisely described as a thin layer of elemental selenium in its amorphous form which is generally deposited on a conductive substrate by vacuum evaporation or other techniques known in the art. Selenium plates of this type have enjoyed wide many bond expensive to produce, requiring high purity material and closely controlled manufacturing techniques, but, in addition, in common with,all reusable xerographic plates, its use requires the steps of transferring the toner image from the plate to a paper copy sheet and also the step of cleaning the plate after this transfer step. n The other type of xerographic plate in commercial use today is generally known as the pigment-binder-type plate which is described in U. S. Patent 3,121,006 to Middleton and Reynolds. Broadly speaking, this type of plate' consists of a layer of a finely divided, photoconductive pigment dispersed in an insulating film-forming plastic binder all coated on a supporting base such as paper. Since zinc oxide (pigment made by the French process is the current photoconductive pigment of choice for this type of plate, it is generally referred to in the art as a zinc oxide binder plate. Even though the zinc oxide binder plate tends to simplify the xerographic process by eliminating the transfer and cleaning steps, it has been found that this type of p¾ate suffers from light fatigue of its electrical properties so that jOnce exposed to a light image, it cannot ordinarily be reused until it has been rested for a relatively long period of time in the dark. Consequently, even though the photoconductive xerographic plate, the cost of this coating may only be amortized over the one copy it is capable of . making, as compared with the selenium plate whose cost may be amortized over many thousands of copies. Thus, on a per copy basis, the binder plate is more expensive to use than the selenium plate. It is also to be noted that although the selenium plate produces copy on ordinary office bond paper, the copy produced from a binder plate is, of course, formed and fixed upon the coated surface of the plate itself and many users find copies on this type of coated paper to be objectionable because of its feel and appearance.

The present invention provides a photoresponsive member suitable for use in electrophotography comprising a sheet including photoconductive insulating fibers .

According to the invention it is possible to form a xerographic plate from fine, photoconductive' fibers which are brought together to make up a fibrous sheet or paper resembling an ordinary cellulosic paper.

The fibers may either be felted or woven into the desired sheet form and may be mixed with a proportion, preferably a minor proportion of 1 non-photoconductive fibers, such as wood, rag or synthetic 2 fibers. Once the photoconductive fibers have been manufactured, I 8 as described more fully hereinafter, they may, for example, be 4 woven into a fabric which, if thin fibers are employed, will 6 resemble paper. In another technique more closely approximating β conventional papermaking, long photoconductive fibers, are made 7 and cut to short lengths which may be referred to as "staple". 8 This staple is the basic ingredient of the "stock" or "furnish" 9 for the sheet or papermaking process, which in this instance, 0 shall be referred to more broadly as the "felting process". 1 < ■ · In those instances where a synthetic fiber which will 2 fibrillate on beating, (such as highly oriented or wet spun 3 polyacrylonltrile or its copolymers) is used, stock preparation 4 equipment and techniques used in the pulp and paper industry 6 on wood pulp fibers may be employed to attain the desired degree 6 of fibrillation in aqueous suspensions of the staple. After 7 any; mechanical stock treatment which may be required, non-fibrous 8 additives, such as sizing, fillers, and natural or synthetic 9 adhesive resins, are mixed into the furnish as desirable. The 0 addition of such resins in the f,orm of a water late or a: 1 dispereible resin solution ^Ln a manner similar to that employed 2 to impart higher wet and/or, dry, strength to cellulose papers 3 may be,, particularly valuable where non-fibrillatable, synthetic, 4 photoconductive fibers are usednwithout any cellulose fibers in 6 the furnish. As is well known to those skilled in the paper-6 making art, wood pulp fibers and cylindrical fibers of some 7 synthetic resins may be fibrillated by a process of mechanical 8 abrasion in aqueous suspension known in the papermaking art 9 as "beating" or "refining". t I rfibrillating, these fibers these hairy fibrils are formed into a mat on\ the wire of the 2 papermaking machine, and they become mechanically entangled. 8 Upo subsequent water removal, surface tension forces tend 4 to draw the fibrils into sufficiently intimate contact to 6 permit strong bonds to form or be formed between adjacent fiber β surfaces, thereby developing a high degree of strength and 7 integrity in the final sheet. 8 In those instances where it is desired to employ a 9 synthetic fiber which cannot be fibrillated by conventional 0 cellulose pulp refining techniques, any one of a number of 1 alternatives web formation and bonding techniques may be taken 2 advantage of. In this regard, specific reference is made to 3 a book. entitled, "SYNTHETIC FIBERS IN PAPERMAKING", 0. A. 4 Battista, Editor, published by Interscience Publishers, Division 6 of John Wiley and Sons, 1964, for a detailed treatment of the 6 varipus web formation and bonding techniques which may be 7 employed with various synthetic resin fibers. In the event 8 that; this type of synthetic, photocpnductive fiber is employed^ 9 it may, for example, be desirable to disperse a partial solvent 0 or swelling agent for the fiber in the furnish to soften or 1 swell tfhe fiber and promote larger areas of inter-fiber contact 2 during drying of the sheet. 8 Another technique is tp use synthetic fibers which 4 are made initially in a specially fibrillated form according 6 .to the .teachings of U. S. Parent,,2,999,788 to Morgan. This β type, of, specially fibrillated synthetic fiber is referred to 7 by tfhe tradename "Fibrid" and these Fibrids may be used either 8 alone t^o produce a complete "paper" sheet or in a blend with 9 conventionally shaped fibers to hold all f bers together by 1 after its initial formation rather than adding these materials 2 to the furnish at the wet end of the machine, a coating device, 3 such as a sizing press, is frequently located in the drying 4 section of the machine before the last few drying rollers so 6 that this material is dried before the web is wound up on the β reel. It is also to be understood that off machine web 7 treatment techniques, such as tub sizing and super calendaring, 8 may also be employed once the web reel is removed from the 9 machine, where suitable. 0 I Where a woven photoconductive sheet is to be produced, 1 the fibers are spun in long lengths by ordinary spinning 2 techniques and woven on conventional textile machinery. After 3 weaving, they may be cut to sheet size or left in roll form as 4 desired.

The photoconductive fibers themselves may take many 6 different forms having an internal structure which Is either 7 homogeneous or heterogeneous and may be manufactured by a 8 number of different techniques, depending upon the particular ». nature of the fiber to be employed. 0 Heterogeneous fibers may, for example, consist of 1 any suitable insulating filmTformlng binder with a suitable 2 photoconductive pigment dispersed therein with pigment selection 3 depending on desired sensitivity, cost, physical properties, 4 spectral response, etc. Typical iphotoconductive pigments 6 include not only organic pigments, such as Quinacridones and 6 metal-free phthalocyanine, but also Inorganic pigments, such 7 as zinc sulfide, zinc cadmium sulfide, French process zinc oxide, 8 cadmium sulfide, cadmium selenide, zinc silicate, cadmium . 9 sulfoselenide, and a number of others listed in U. S. Patent particular resin-pigment combination selected. Thus, for example, with zinc oxide pigment the ratifco would range from one part by weight of pigment to, one part Vy weight of binder, to about eight parts by weight of pigment to cne part by weight of binder. "Fibrids" incorporating these pigments may also be fabricated, as described in the examples which follow and in the Morgan patent. These "Fibrlds" are preferred for. felting while conventional fibers are preferred for a woven sheet.. In addition to the above-described binders and pigments, it is to be noted that the ibe may be composed of inorganic binders, such as glass, with photoconductive pigments dispersed therein, and reference is hereby, made to U. S. Patent 3,151,982 to Corrsin for a teaching of j photoconductive pigment-glass binder systems. It is also to be noted that the pigments employed in making these heterogeneous fibers may be dye sensitized as described, for, example, in U. S. Patent 3*052,5 0, to Greig, with the types and, percentages of dyes used being those conventionally used in; the, xerographic binder plate art. Although the binder materials described above are generally not photoconductive themselves, ,it is to be noted that any suitable homogeneous photoconductive material may also be employed in conjunction with a photoconductive pigment to make up a more highly sensitive .photoconductive fibei^. f, In addition to heterogeneous or two-phase fibers, homogeneous or single-phase fibers may also be employed in connection with this invention. r, Not only may the fibers be made up wholly of one suitable material which is, in itself, photoconductive, but suitable blends, copolymers, terpolymers, etc., of photoconductors and non-rphotoconductive materials I particularly desirable where the photoconductive material itself does not have the desired physical or chemical properties for the final fiber. Thus, for example, a polyvinyl carbazole of a particular molecular weight may be found to be an excellent photoconductor; but by itself, may have poor physical properties so that, high quality fibers cannot be made directly from it.

In this instance, then, the photoconductive material may be blended or copolymerlzed with any suitable material to give it stronger physical properties. For example, polyvinyl carbazole may be ;blended with a vinylldene chloride or vinyl chloride polymers or copolymers or itself ncopolymerized with such a vinyl monomer-; to yield fibers which are^ both physically strong and photoconductive. It is to be noted that neither the photoconductl substance Itself nor the strengthening additive (if one is used) must of necessity be a. synthetic polymer. Either or both may be natural or synthetic materials and may be either a , monomolecular substance, an oligomer, a polymer, copolymer, mixturei? thereof, etc. As stated, above, any suitable photoconductive ^material may be employed in this type of homogeneous · fibe with the selection of the particular photoconductor depending upon ;the properties desired in the final fiber, the material with which it is to be blended or copqlymerlzed, etc. Typical photoconductive materials, many of which are miscible with. strengthening additive resins, in lude: polyvinyl carbazole anthracene, polyvinyl anthracene . anthraqulnone, acylhyl'azon derivatives, such as -dimethylaminobenzylidenebenzyhydrazide; : oxadlazole derivatives such as 2,5-bis-(p-amlnophenyl-(l) ) , 1, ,3, 4-oxadlazole; triazole derivatives such as 2, 5-t>is-( '- i dlme hylamlnophenyl), 1, 3, ^triazole; pyrazoline derivatives i ! 1 phenyl-imidazolonej imidazolethione derivatives such as 2 4- (p-trlmeth lamlnophenyl)-5-phenylimidazolethione 2- (4 '- 8 methoxyphenyl)-benzthiazole, 2-phenyl-benzoxazole. Materials ' 4 showing photoconductive response may also be made by forming charge transfer complexes' wl,th the Lewis acids (electron 6 acceptors) and anyone of a number of resins which are ordinarily 7 not highly photoconductive. Typical resins which may be I 8 complexed in this manner include phenol aldehydes, epoxles, 9 phenoxies, polycarbonates, melamines, polyimides, polyurethanes, aromatic silicones, polystyrene, poly(2-vinyl-quinoline) , 11 poly-iSfS'-dlmethyl-diphenylene^^' ), polyvinylxylene, 12 poly( j|Vinyl-napikhalene) , polyindene, polyvinyl imidazole, 13 poly(3-Ylnyl-pyrene) ί mixtures and copolymers of the above. 14 Typical Lewis acids are phenyl acetic acid, 6-methyl-cumaryl- 15 acetic :acid-( ), maleic acid, cinnamlc acid, benzoic acid, 16 l-(4; di^ethylamino benzoyl)-benzene 2-carbocyclic acid, phthallc 17 acid* tetrad orophthalic acid, organic sulfonic acids, such as 18 4-toluene sulfonic acid, benzene sulfonic acid, organic .10 phosphonlc acids, such as 4-chloro-3-nitro-3-benzene phosphonic acid, 4^nitrophenol, picric acid,i acetic anhydride, succinic 21 anhydride^ maleic 'anhydride, phthallc anhydride, tetrachlorophthalic 22 anhydride, chrysene-2,3i8,9-tetra1carboxyllc acid anhydride, 23 aluminum chloride, zinc chloride,, ferric chloride, stannic 24 ' chloride, arsenic trichloride, stannous chloride, antimony 26 penta-chloride, boron trifluoride, boron trichloride, 1,4-benzo- 26 quinone, . ,5-dlchloro-benzoquinone, 2,6-dlchlorobenzoqulnone, 27 chloijanll, l,4-naphthaqulnone: 2,3-dichloro-l,4-naphthaqulnone, 23 a/lthraquinone, 2-methylanthraquinone, 1-chloroanthraqulnone, 29 phenanthrenequinone, acenaphthoquinone, pyranthrenequinone, I 1 benzene, bromal, 4-nitro benzaldehyde, 2,6-dichlorobenzaldehyde, 2 2-ethoxy-l-naphthaldehyde, Aldehyde, pyrene-3-8 aldehyde, oxindal-2-6-aldehyde, pyridin-2,)S-dialdehyde, biphenyl-4 4-aldehyde, furfural, acetophenone, benzophenone, 2-acetylnaph- 6 thalene, bcnnylj benzoin, 5-benzoyl acenaphthalene, biacondloni -β 9-acethp.anthracene, 9-benzoyl-anthracene, 4-(4 dimethyl amino 7 cinnamoyl)-l-acetyl-benzene, anilcle, of acetic acid, (1,3)-8 indanedione, acenaphthenqulnone dichloride and 2,4,7 trinltro- · β fluorenone. Lewis acids can also be employed to advantage to 0 increase the sensitivity of virtually all of the aromatic 1 photoconductors and zinc oxide listed above. Further 2 sensitization can be achieved by- the addition of dyes such 3 as rhodamine B extra, methyl violet, rose Bengal, acridine 4 yellow, etc.

Once the homogeneous or heterogeneous photoconductive 6 material is selected, it may be. spun into a fiber by any one 7 of the conventional fiber epinning techniques, such as melt 8 spinning, dry spinning, or wet spinning, as described, for 9 example, on pages 513 through 519 of the textbook of POLYMER 0 SCIENCE by P. . Billmeyer, Jr., published by Interscience " 1 Publishers in 1962. Fiber diameter is not critical to the 2 process and may range widely. Since photoconductive pigments 3 such as zinc oxide are available in particles sizes ranging 4 from 0o2 to 0.5 microns in diameter, there is no problem in including these pigments even in relatively small diameter 6 fibers on the order of 2 microns in diameter, and with larger 7 fiber diameters of say, for, example, 110 microns in diameter, 8 the-problem is clearly insignificant. 0 I, I In addition to conventional spinning techniques ou¾ the invention. Not only may homogeneous photoconductive materials be formed into "Flbrids" according to the Morgan patent procedure, but flbrids may also be prepared having a heterogeneous structure with high loadings of photoconductive pigments according to the techniques described in Examples 171 and 172 of the Morgan patent. These flbrids are a preferred form of fiber for use in the felted sheet embodiment of the Invention because of their fibrlllated structure and because this "Plbrid" technique may be used to form fibers of many resins-and resin-pigment blends, of materials which are extremely difficult or virtually impossible to form by conventional spinning techniques. Both these flbrids and the more conventionally shaped fibers may be prepared using any suitable insulating resin. Typical insulating resins include; polyacrylo-nitriles, epoxles, phenolics, alkyds, various other polyesters, polyethers, polyole ins such as;.polypropylene, polyamldes, modified rosins, acrylates, methacrylates, vinyl acetates, vlnylldene chlorides, styrenes, ,vinyl chlorides and other vinyls, polycarbonates, polyurethanes, mixtures and copolymers of these, etc. These flbrids may not;only be used alone In the papermaklng process but alsd -may be used in combination with conventional staple fibers made from either the same or different resins.

I ·. ·, The terms "fiber" ; and 1 "fibrous" are to be taken in their broadest sense throughout the specification and claims of t^hls application and are to be understood as encompassing both conventionally spun fibers-and the "Flbrids" referred to supra.,; It is also to be understood that the plate of this invention may not only be used i,n xerographic imaging, and I ' I ' ! technique adapted to make use of its photoresponslve properties.

It is to be understood that the particular imaging technique to be used may be quite important i the selection of the specific materials to be employed in the plate of this invention. Thus, for example, plates including zinc oxide pigment are generally found to have high light fatigue and are particularly desirable for pre-exposed chargeless imaging as well as for conventional xerographic imaging. Even in the more' conventional forms of xerographic imaging, material selection may e ^dictated by the desired process steps. Thus, for example, plates Including a zinc oxide photoconductor will be found to have superior response on negative charging while plates including a metal-free phthalocyanine photoconductor will be found to have superior response on positive charging. In forming images ;on the plate of this invention, any one of a large number of well-known xerographic processing techniques may be employed. Thus, for example, charging of the plate may be accomplished by induction, as disclosed in U.rS. Patent 2,934,649 to Walkup, by corona charging with the plate residing on a conductive backing, as described in U. S. Patent 2,588,699 to Carlson, or by two-sided simultaneous opposite polarity charging as described in U. S. Patent 2,922,883. Any conventional exposure source ;may be employed, and development may be accomplished either by the pascade technique, as described in U. S. Patents 2,618,552 and 2,638,416, by magnetic brush development, as described in U. S. Patent 3,015,305 or by; any, one of a number of other known development techniques. Once the image is developed, it may be fixed in place on the plate surface by heat fusing, solvent · mist spray, adhesive overcoating, laminating, or other techniques and the appended claims is to be understood to include not only a rigid structure to which the term is applied in the silver 3 halide. photographic arts, but also to include a flexible 4 paper-like sheet as extensively described herein. 6 The general nature of the invention having been set β forth, the following examples are given ih further illustration 7 thereof. Unless otherwise indicated therein, all parts are 8 taken by weight.

» EXAMPLE. I 0 a 1 part by weight of polyacrylonitrlle is dissolved ' 1 in 10 parts by weight of N, ;N-dlmethylacetamlde to form a -2 solution to which there is added .002 parts by weight of 3 bromphenol blue dye and 2 parts by weight of Photox 801 zincj1 4 oxide (a French process zinc oxide, available from the New Jersey Zinc' Company) . This composition is then ball milled 6 fpr^abput 1 half hour so as to disperse the zinc oxide particles 7 throughout the solution. The solution is then wet spun by 8 extruding it into an aqueous; coagulating bath to form a bundle 0 of filaments which are then withdrawn from the bath and given1 0 an prientation stretch. After partial drying to about 10 1 moisture contents the fibers are cut to staple length of about 1/4 lneh. This wet spinning process results in an uncollapsed flb(Ejr structure which is charged into a 1 pound Valley Labpratpry beater at a consistency of 0.75 (10 liters pf water to 75 grams of fiber) and.beaten for 2 hours with a 10 pound weight on the bed plate arm pf the beater. A hand sheet liquid is then poured as an even stream into 1.6 liters of a 0.25^ aqueous solution of carbox -methyl cellulose at 12°C. while 3 it is stirred in a blender. The fibrids produced are washed 4 repeatedly with water and then re-dispersed in water to a 6 consistency of 0.75. A hand sheet is then prepared from this β re-dispersed fiber, dried and pressed at 175°C and 640 psi for 7 1 minute, resulting in a high strength sheet with a cyan color. 8 The imaging procedure of Example I is repeated » except that the positively charged side of the sheet is exposed 0 to projected and enlarged negative microfilm image through 1 an optical halftone screen and developed with white toner 2 particles and carrier beads with a coating selected to charge 3 e 4 6 • 1 - EXAMPLE IV 6 ; * 20 grams of the zinc oxide particles described 7 in Example I are added to 20 grams of a 15 solution of a 8 nylon copolyamide (60/40 by weight of caprolactam and 0 hexamethylene adipamide) in methanol/CaCl2 (96/4) as a solvent. 0 To this solution, there is added 10 milligrams of rose bengal 1 dye and after stirring, the mixture is added in a thln^ even 2 stream to 1 liter of 70$ aqueous glycerol at room temperature 3 while it is being agitated strongly in a blender. The resulting 4 fibrids are washed with water tp remove ionic salts and 6 re-dispersed in a gallon ofi water in a large blender, at high β speed.;; A small hand sheet taken from this dispersion is then 7 dried and pressed at 170°C, 2400 psi for 30 minutes, resulting 8 in a strong photoconductive paper. 9 The sheet is then:,first exposed to a light .image to to a backing plate behind the she,et using magnetic iron powder as a carrier and a carbon black pigmented polystyrene toner. The developed image is then heat fused resulting in a good quality fixed copy.

■ EXAMPLE V The process of Example IV is repeated except that to the re-dispersed fibrids there is added an aqueous dispersion containing grams of conventionally spun nylon 66 filaments containing 3 parts of the zinc oxide pigment of Example I to · each p¾rt of nylon 66 (polyhexamethylene adipamide) resin.

A sheet; of this fibrid suspension is then taken, dried and, heat; pressed as in Example IV with similar results, j - EXAMPLE VI A fiber-making blend consisting of 50 parts by weight of polyvinyl carbazole (suspended as microscopically dispersed pigment, of 0.5 - 2 microns particle size), 0 parts by weight of a- polyvinyl chloride-acetate qopolymer and parts by weight of 2> -fcrinitr°fluorenone £s made up, spun and chopped to 1/4 inch lengths. These fibers are then dispersed in water at 0.60 consistency and a polyvinyl acetate aqueous emulsion containing parts, by weight- of polymer , solids is then added and a hand o t ■ sheet is taken and dried at 175 F. producing a strong sheet '·.; with good xerographic properties.

,. - EXAMPLE VII , .' i, The procedure of Example VI is repeated except that the polyvinyl carbazole is replaced with the same amount of 2,5-bis(p-aminophenyl) 1,3,4-oxadiazole blended therein in solution with .05 parts of bromphenol blue dye with about equivalent results to those produced in Example VI except for ' EXAMPLE VIII About one part by weight of a polycarbonate resin, obtained by direct reaction of phosgene with bisphenol-A, is dissolved in 5 parts by weight of dichloromethane to form a solution to which there is added 5 parts by weight of p-dioxan. About 1/4 part by weight of 2,4,7-trinitrofluorenone and 0.005 parts by weight of fluorol 7GA dye are added to the polycarbonate resin solution and stirred so as to achieve solution to form a dye sensitized charge transfer complex. The solution is then dry spun into fine fibers from a spray drying head. The fibers are then woven together to form a small sheet which is imaged according to the procedure of Example I with good, results. The endj product of this process is a xerographic plate capable of forming high quality xerographic images having good physical properties and appearance.

EXAMPLE IX A spinning composition made up of 85 parts of polyvinyl carbazole, 15' parts of polypropylene, 5 parts of 2,4,7-trlnitr6-fluorenone and .005 parts of brilliant green dye is made up and melt spun at 340°F. into fine fibers. These fibers are then . woven together into a small sheet, as in Example VIII, and the sheet is hot calendared at 275°F. to Increase its strength.

The sheet thus produced has good photoconductive response, physical properties and appearance. ' * '' ·' EXAMPLE X .' A spinning composition made up of 100 parts by weight of a high strength stereospecific polyvinyl carbazole (made according to Example I of U.-S. Patent 3*136,7 6 with a mono- ■t . ethyl aluminum dic/loride catalyst), 5 parts by weight of made up and melt spun to form fibers which are given an orientation stretch and woven together into a small sheet as 3 in Example VIII. The sheet thus produced has good photoconductive 4 response, physical properties and a pleasin pale green £ appearance. β It is to be understood that this invention may be 7 carried out in many ways not specifically described herein but 8 coming within the spirit of the invention. For example, a very 9 thin sheet made up of woven or felted photoconductive fibers, 0 as described above, may be laminated to a sheet of conventional 1 paper to impart added strength and improved appearance thereto. 2 Other embodiments of the invention coming within the spirit of 3 the invention will be apparent to those skilled in the art. 4 6 β 7 8 9 0 1 2 3 4 6 6 7 8 9

Claims (9)

1. HAVING NOW paricularly described, and ascertained the nature of our said invention and in. what manner the same is to he performed we declare, tha what we claim is:- Mxxxxxxxmmxx WHAT WE CLAIM IS: 1. A photoresponsive member suitable for use in electrophotography comprising a sheet including photoconductive insulating fibers.

2. A photoresponsive member according to claim 1 wherein said sheet consists substantially entirely of photoconductive insulating fibers.

3. A photoresponsive member according to claim 1 wherein said sheet also includes rion-photoconductive fibers, preferably in a minor proportion.

4. A photoresponsive member according to any of claims 1 to 3 wherein the fibers are felted together.

5. A photoresponsive member according to any of claims 1 to 3 wherein the fibers are woven together.

6. ; A photoresponsive member according to claim 4 wherein said fibers are fibrillated.

7. A photoresponsive member according to claim 6 wherein said fibers are fibrids.

8. A photoresponsive member according to any of the preceding claims wherein said photoconductive insulating fibers are homogeneous.

9. A photoresponsive member according to any of the preceding claims wherein said photoconductive insulating fibers are heterogeneous . 11. A photoresponsive member according to claim 10 wherein said pigment is an inorganic pigment. 12. A photoresponsive member according to claim 11 wherein said inorganic pigment is zinc oxide . 13. A photoresponsive member according to claim 10 werein said pigment is an organic pigment. j 14. A photoresponsive member according to claim 13 wherein said pigment is a phthalocyanine^ 15. A photoresponsive member according to any of claims110 to 14 wherein said binder is an organic resin. 16. A photoresponsive member according to any of claims 10 to 12 wherein said binder is an inorganic material, preferably a glassy material. 17 A photoresponsive member according to claim 8 wherein said photoconductive insulating fibers are wholly composed of a photoconductive insulating material. 18. A photoresponsive member according to claim 8 wherein said photoconductive insulating material is a homogeneous mixture of a photoconductive material and a non-phptoconductive material . 19. A photoresponsive member according to claim 7 or wherein said photoconductive material includes a photo-j conductive organic charge transfer complex. 20. A process of forming an image comprising, applying electrostatic charge to a photoresponsive member 21· Λ process of forming an image comprising forming a latent conductivity pattern on a photoresponsive member as claimed in any of claims 1 to 19 by exposing said member to a pattern of activating radiation and then developing said latent conductivity pattern, 22o A process according to claim 21 wherein said latent conductivity pattern is developed by bringing the exposed member into contact with a colored electroscopic developing material, and applyin a unidirectional electric field through said 'member and said electroscopic material, whereby said electroscopic material is deposited on the surface of said member in image-wise configuration. 23· A photoresponsive member suitable for use in electrophotography substantially as hereiridescribed* For the Applicants DH. REIUHOLD 0ΌΗΝ & PARTNERS