CA1129702A - Photoconductive layer containing a crystallization inhibiting mixture of aryl-substituted methanes - Google Patents
Photoconductive layer containing a crystallization inhibiting mixture of aryl-substituted methanesInfo
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- CA1129702A CA1129702A CA338,119A CA338119A CA1129702A CA 1129702 A CA1129702 A CA 1129702A CA 338119 A CA338119 A CA 338119A CA 1129702 A CA1129702 A CA 1129702A
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- hydroxyl
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- 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, 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
- G03G5/0601—Acyclic or carbocyclic compounds
- G03G5/0612—Acyclic or carbocyclic compounds containing nitrogen
- G03G5/0614—Amines
- G03G5/06142—Amines arylamine
- G03G5/06144—Amines arylamine diamine
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- General Physics & Mathematics (AREA)
- Photoreceptors In Electrophotography (AREA)
Abstract
-i-PHOTOCONDUCTIVE LAYERS
Abstract Or the Dlsclosure Photoconductive layers containing a crystalli-zation inhibiting mixture of at least two different organic photoconductors selected from the class of photoconductors represented by the following formula wherein R is selected from the group consisting of alkyl, aralkyll and substituted and unsubstituted aryl;
X and X' which may be the same or different are selected from the group consisting of hydrogen, alkyl, alkoxy, hydroxyl, NO2 and halogen;
Y and Y' which may be the same or different are selected from the group consisting of hydrogen, alkyl, alkoxy, hydroxyl, halogen and NO2;
A and B, when taken alone may be the same or different, are selected rrom the group consisting of hydrogen, alkoxy, hydroxyl, halogen, substituted or unsubstituted aryl, alkyl, cycloalkyl group having four to ten carbon atoms and cycloalkenyl group having four to eight carbon atoms; or A and B, when taken together, represents suf-ficient atoms to rorm together with the carbon to which they are attached a substituted or unsubstituted carbocyclic ring having from 4 to 10 carbon atoms, are disclosed.
Abstract Or the Dlsclosure Photoconductive layers containing a crystalli-zation inhibiting mixture of at least two different organic photoconductors selected from the class of photoconductors represented by the following formula wherein R is selected from the group consisting of alkyl, aralkyll and substituted and unsubstituted aryl;
X and X' which may be the same or different are selected from the group consisting of hydrogen, alkyl, alkoxy, hydroxyl, NO2 and halogen;
Y and Y' which may be the same or different are selected from the group consisting of hydrogen, alkyl, alkoxy, hydroxyl, halogen and NO2;
A and B, when taken alone may be the same or different, are selected rrom the group consisting of hydrogen, alkoxy, hydroxyl, halogen, substituted or unsubstituted aryl, alkyl, cycloalkyl group having four to ten carbon atoms and cycloalkenyl group having four to eight carbon atoms; or A and B, when taken together, represents suf-ficient atoms to rorm together with the carbon to which they are attached a substituted or unsubstituted carbocyclic ring having from 4 to 10 carbon atoms, are disclosed.
Description
PHOTOCONDUCTIVE LAYERS
This inventlon relates to photoconductlve layers. In partlcular~ the ln~entlon provides novel photoconductive layers contalning a mi~ture of organl~
photoconductors.
The use of photoconductive elements in electro-photographlc processes ls well known. Such elements generally comprise a conductlve support bearing a photo-conductive layer.
The photoconduc~ive layer generslly comprises a photoconductive material dispersed ln an electrically insulating binder. Among the materials which have been described as useful organic photoconductlve materlal~ are tri-substituted methanes such a~ dlsclosed in U.S. ~atent 3,820,989 granted to Rule et al on June 28, 1974 and tri-arylmethane leuco bases such as dlsclosed in U.S. Patent 3,542,547 granted to Wilson on November 24, 1970.
It has been dlscovered that photoconductlve layers comprising the organ:Lc photoconductlve makerials disclosed ln the aforementioned patents are capable o~
producing high resolution images at sultable ~xposures.
However, it has been discovered that such photoconductive layers containing a slngle photoconductor often will not per~orm well a~ter a perlod of ~torage or 1~ the element was prepared uslng elevated drylng temperatures. In these stored or drled layers J the organlc photoconductor tends to migrate to the surface of the layer and crystalllze out in a snake-like pattern. Such crystalllzation or "snake" defects impair the capability of the photoconductlve layer ~or produclng high resolution lmages.
Summary Or the Inventlon _ We have now dlscsvered that the crystalllzation or "snake~' problem sur~ered by the above-mentioned photo=
c~nductiYe layers can be overcome wikh an electrophoto-graphic layer comprlsing an electrically insu~atlng bin~erand a crystalllzation ~nhlbiting mlxture Or at least two d~fferent organlc photoconductors ~elected from the clas6 ~f organic photoconductors represented by the ~ormula ~Z~7C~Z
~R~
X~
wherein R is selected from the group consisting o~ alkylS
aralkyl, and substituted and unsubstituted aryl;
X and X' which may be the same or different are selected from the group consisting of hydrogen, alkyl, alkoxy, hydroxyl, N02 and halogen;
Y and Y' whlch may be the same or different are selected from the group conslstlng of hydrogen, alky:L, alkoxy, hydroxyl, halogen and N02;
A and B, when taken alone may be the same or dif~erent, are selected rrom the group consisting o~ hydrogen, alkoxy, hydroxyl, halogen, substituted or unsub~tituted aryl, alkyl, cycloalkyl group having four to ten carbon atoms and cycloalkenyl group havlng ~our to eight carbon atoms; or A and B, when kaken together, represents su~-ficient atoms to form together wlth the carbon to which they are attached a substltuted or unsubstltuted carbocycllc ring havlng from 4 to 10 carbon atoms;
and wherein each organlc photoconduct~r may be present ln sald layer up to the llmlt of lts ~olubillty ln the blnder.
The terms alkyl and alkoxy as used herein refer to compounds generally contalning ~rom 1 to 10 carbon atoms and lncludes substltuted alkyl groups. Aryl and the prefix ara refer to substltuted and unsubstltuted phenyl, naphthyl and anthryl groups wherein the substltuents are selected rrom the group consistlng of dlalkylamino, alkylamino, amino as well as the groups represented by X, X'~ Y and Y'~
Formula I, representing the class of organic photoconductors u~eful in the present in~ention, includes certain of the organic photoconductive materials disclosed ln aforementioned U.S. Patent 3,542,547 and UeS~ Patent S 3,820,989.
Photoconductive elements comprising photocon-ductive layers of the type ~ust described, are much more resistant to the ~ormatlon of "snakes" resultlng from cry~al-lization of the organic photoconductors than elements comprising photoconductive layers containing a single photo-conductor represented by Formula I.
Representative Formula I organic photoconductors from which the mixture of at .least two photoconductors of the present invention may be selected, is set out in Table I.
TABLE
1. 4,4'-bis(diethylamino)~2,2'-dimethyltrlphenylmethane
This inventlon relates to photoconductlve layers. In partlcular~ the ln~entlon provides novel photoconductive layers contalning a mi~ture of organl~
photoconductors.
The use of photoconductive elements in electro-photographlc processes ls well known. Such elements generally comprise a conductlve support bearing a photo-conductive layer.
The photoconduc~ive layer generslly comprises a photoconductive material dispersed ln an electrically insulating binder. Among the materials which have been described as useful organic photoconductlve materlal~ are tri-substituted methanes such a~ dlsclosed in U.S. ~atent 3,820,989 granted to Rule et al on June 28, 1974 and tri-arylmethane leuco bases such as dlsclosed in U.S. Patent 3,542,547 granted to Wilson on November 24, 1970.
It has been dlscovered that photoconductlve layers comprising the organ:Lc photoconductlve makerials disclosed ln the aforementioned patents are capable o~
producing high resolution images at sultable ~xposures.
However, it has been discovered that such photoconductive layers containing a slngle photoconductor often will not per~orm well a~ter a perlod of ~torage or 1~ the element was prepared uslng elevated drylng temperatures. In these stored or drled layers J the organlc photoconductor tends to migrate to the surface of the layer and crystalllze out in a snake-like pattern. Such crystalllzation or "snake" defects impair the capability of the photoconductlve layer ~or produclng high resolution lmages.
Summary Or the Inventlon _ We have now dlscsvered that the crystalllzation or "snake~' problem sur~ered by the above-mentioned photo=
c~nductiYe layers can be overcome wikh an electrophoto-graphic layer comprlsing an electrically insu~atlng bin~erand a crystalllzation ~nhlbiting mlxture Or at least two d~fferent organlc photoconductors ~elected from the clas6 ~f organic photoconductors represented by the ~ormula ~Z~7C~Z
~R~
X~
wherein R is selected from the group consisting o~ alkylS
aralkyl, and substituted and unsubstituted aryl;
X and X' which may be the same or different are selected from the group consisting of hydrogen, alkyl, alkoxy, hydroxyl, N02 and halogen;
Y and Y' whlch may be the same or different are selected from the group conslstlng of hydrogen, alky:L, alkoxy, hydroxyl, halogen and N02;
A and B, when taken alone may be the same or dif~erent, are selected rrom the group consisting o~ hydrogen, alkoxy, hydroxyl, halogen, substituted or unsub~tituted aryl, alkyl, cycloalkyl group having four to ten carbon atoms and cycloalkenyl group havlng ~our to eight carbon atoms; or A and B, when kaken together, represents su~-ficient atoms to form together wlth the carbon to which they are attached a substltuted or unsubstltuted carbocycllc ring havlng from 4 to 10 carbon atoms;
and wherein each organlc photoconduct~r may be present ln sald layer up to the llmlt of lts ~olubillty ln the blnder.
The terms alkyl and alkoxy as used herein refer to compounds generally contalning ~rom 1 to 10 carbon atoms and lncludes substltuted alkyl groups. Aryl and the prefix ara refer to substltuted and unsubstltuted phenyl, naphthyl and anthryl groups wherein the substltuents are selected rrom the group consistlng of dlalkylamino, alkylamino, amino as well as the groups represented by X, X'~ Y and Y'~
Formula I, representing the class of organic photoconductors u~eful in the present in~ention, includes certain of the organic photoconductive materials disclosed ln aforementioned U.S. Patent 3,542,547 and UeS~ Patent S 3,820,989.
Photoconductive elements comprising photocon-ductive layers of the type ~ust described, are much more resistant to the ~ormatlon of "snakes" resultlng from cry~al-lization of the organic photoconductors than elements comprising photoconductive layers containing a single photo-conductor represented by Formula I.
Representative Formula I organic photoconductors from which the mixture of at .least two photoconductors of the present invention may be selected, is set out in Table I.
TABLE
1. 4,4'-bis(diethylamino)~2,2'-dimethyltrlphenylmethane
2. 4',4"-bis(diethylamino)-2,6-dichlo.ro-2',2"-dimethyl-triphenylmethane
3. 4,4'-bis(diethylamino)-2,2'-dimethyldiphenyl-a-naphthylmethane
4. 2',2"-dimethyl-4,4',4"-tris(dimethylamino)-trlphenyl-methane
5. 4',4"-bis(diethylamino)-4-dimethylamino-2',2"-5',5"-tetramethyltriphenylmethane
6. 4',4"-bis(diethylamino)-2-chloro-2',2"-dimethyl-4-dimethylaminotriphenylmethane
7. 4',4"-bis(diethylamino)-4-dimethylamino-2,2',2"-trimethyltriphenylmethane
8. 4',4"-bis(dimethylamino)-2-chloro-2',2"-di~ethyl-triphenylmethane
9. 4',4"-bis(dimethylamlno)-2',2"-dimethyl-4-methoxy-triphenylmethane
10. 4,4'-bis(benzylethylamino~-2,2'-dimethyltriphenyl-methane
11. 4,4'-bis(diethylamino)-2,2',5,5'-tetramethyl-triphenylmethane
12. 4,4'-bis(diethylamino)-2,2'-diethoxytriphenyl-methane
5 TABLE I Gont'd.
13. 4,4'-bis(diethylamino)-2,2' dimethyldlphenyl-~-naphthylmethane
14. 4,4'-bis(dlethylamino)-2,2'-dimetllyldîphenyl-9-anthrylmethane
15. 4,4',4"-trlsdiethylamino-2,2',2"-trimethyltrlphenyl-methane
16. 1,1-bis(4-N,N-diethylamlno-2-chlo:rophenyl)-2-phenylethane
17. 1,1-bis(4-N,N-diethylamino-2-methoxyphenyl)-2-phenylethane
18. bis(4-N,N-diethylaminophenyl)cyclopent-2-enyl methane
19. bis(4-N,N-diethylamino-2-methylphenyl)cyclobut--2-enyl methane
20. 1,1-bis(4-N,N-diethylaminophenyl)-3-phenylpropane
21. 1,1-bls(4-N,N-dlethylaminophenyl~-2-phenylethane
22. 1,l bls(4-N,N-diethylamlnophenyl)butane
23. bis~4-N,N-dlethylaminophenyl)cyclohexylmethane
24. 1,1-bis(4-N,N-diethylaminophenyl)-2-methylpropane
25. 1,1-bis(4-N,N-dlethylamlnophenyl~heptane
26. bls(4-N,N-diethylamlnophenyl)cyclohex-3-enylmethane
27. 1,1-bis(4-N,N-diethylaminophenyl)-2-ethylhexane
28. 1,1-bis(4-N,N-dlethylamino-2-methylphenyl)-3-phenylpropane
29. 1,1-bis(4-N,N-diethylamlno-2-methylphenyl)-2-phenylethane
30. 1,1-bis(4-N,N-diethylamlno-2-methylphenyl)butane
31. 1,1-bis(4-N,N-diethylamlno-2-methylphenyl)cyclo-hexylmethane
32. 1,1-bis(4-N,N-dlethylamino-2-methylphenyl)-2-methylpropane
33. 1,1-bls(4-N,N-diethylamino-2-methylphenyl)butane
34. bis(4-N,N-dlethylamlno-2-methylphenyl)cyclohex-3-enylmethane
35. bis(4-N,N-diethylamino-2-methylphenyl) 4-methylphenyl-methane
36. bis(4-dlethylamino)l,l 7 l-triphenylethane
37. bls(4-diethylamino)tetraphenylmethane
38. 1,l bis(4-N,N-dlethylaminophenyl)cyclohexane
39. 1,1-bis~4 di~-tolylaminophenyl)cyclohexane
40. 1,1-bis(4-di-~-tolylaminophenyl)-2-methylpropane ~2~7~;~
TABLE I Cont'd.
TABLE I Cont'd.
41. 1,1-bis~4-N,N-dlethylaminophenyl)-4-methylcyclo-hexane
42~ bls(4-N,N-dipropylamlnophenyl)cyclohe~ane
43. 1,1-bis(4-N,N-dlethylaminophenyl)-1-(4-methylphenyl)-ethane
44. 4-N,N-diethylamlnotetraphenylmethane
45. 4,4'-bls(dlethylamino)-4",4"'-dlchlorotetraphenyl-methane
46. 4,4'-bis(dipropylamino)tetraphenylmethane Preferred Embodiments Or the Inventlon In a preferred embodiment of the present lnven-ion, the crystallization lnhlblting mixture Or at least two organic photoconductors is selected ~rom the group consisting ~f bis(4-N,N-dialkylamino-2 alkylaryl)-4-alkyl-arylmethane; l,l-bis(4-N,N-dlalkylamlno-2-alkylaryl)-2-alkylpropane and 4,4'-bis(dlalkylamino)-2,2'-dlalkyltriaryl-methane.
~lectrophotographlc elements comprising the photoconductlve layers of the ~nventlon can be prepared with the photoconducting compounds Or Formula I ln the usual manner, for an example, by blending a dlspersion or solutlon of the selected photoconductors together wlth an electrically insulating binder, and then coating or formin6 a self-support1ng layer of the dispersion or solution. Each Or theorganic photoconductors selected may be included ln the layer up to the solubility limit of each in the binder.
The total amount Or organlc photoconductors in-cluded ln the layer may vary widely but preferably ranges from about 5 to about 40 wel~ht percent based on the total dry weight of the lay~r. The solubllity of each organic photoconductor may be determined by evaluating an organic photoconductor eries in a rilm rorming blnder and determln-lng by dif~erentlal thermal analysis at what conçentrat~Dn the organic photoconductor ~orms a separate phase.
~2~7~;~
The photoconductive layers Or the invention can also be spectrally and/or chemically sensitized by the additlon of effective amounts of sensikizlng compounds.
Sensitizing compounds useful with the photoconductiYe 5 comyounds of the present invention can be elected from a wlde varlety of materials, includlng ~uch materl~ls s pyrylium dye salts including thlapyrylillm dye ~alts and selenapyrylium dye salts disclosed in VanAllan et al, U.S.
Patent 3,250,615; fluorenes; aggregate-type sensitlzers of the type described in U.S. Patent 3~615,414; aromatic nltro compounds of the kind described in U.S. Patent 2,610V120;
anthrones like those disclosed ln ~.S. Patent 2,670,284;
quinones, U.S. Patent 2~670,286; benzophenones, ~.S. Patent 2,670,287; thiazoles, U.S. Patent 2,732,301; mineral aclds;
1~ carboxylic acids such as maleic acid, di- and tri-chloro-acetlc acids, and salicyclic acid; sulfonic and phosphorlc acids; and varlous dyes, such as cyan1ne (lncludlng carbo-cyanlne), merocyanlne, diarylmethane, thlazlne, azine, oxazine, xanthene, phthaleln, acrldlne, azo, anthraquinone dyes and the like and mixtures thereo~. The æensltlzers preferred for use with the compounds Or this lnventlon are selected from pyrylium salts lncluding selenapyryllum ~altæ
and thiapyrylium salts, and cyanlne dyes including carbo-cyanine dyes such as dlsclosed in U.S. Patent 3,597~196.
2~ Where a sensitlzing compound is employed with the binder and organic photoconductors to ~orm a photoconductive layer, a suitable amount of the sensitizlng compound may be mlxed with the coating composition so that, after thorough mlxing, the sensitlzing coMpound i5 uniformly distrlbuted in 3D the coated element. Other methods of incorporating the sensitizer may, howe~er, be employed conslstent with the practice of this invention.
The amount Or ~ens~tlzer that can be added ~o the organic photoconductor layer to give effectlve increaæe~
3~ in speed can vary widely. The optimum concentration ln any given case ~ill vary wlth the ~peclfic photoconductors and senslt~zing compound used. In general3 ~ubstantial speed gains can be obtained where an appropriate sensitlzer is added in a concentration range from about 0.0001 to about 30 percent by weight based on the total dry weight of the photoconductive layer. Normally, a sensitlzer is added in an amount by weight Or from about 0.005 to about 5.0 percent by weight.
Preferred electrically insulating binders for use in preparing the present organic photoconductive layers are film-forming, hydrophobic polymeric binclers having fairly high dielectric strength. Materials of this type comprise styrene-butadiene copolymers, silicone resins; styrene-alkyd resins; silicone-alkyd resins; soya-alkyd resins; poly(vinyl chloride); poly(vinylidene chloride); vinylidene chloride-acrylonitrile copolymers; poly(vinyl acetate); vinyl acetate-vinyl chloride copolymers; poly(vinyl acetals), such as poly(vinyl butyral); polyacrylic and polymethacrylic esters 9 such as poly(methyl methacrylate), poly(n-butyl methacry-late), poly(isobutyl methacrylate), etc.; polystyrene;
nitrated polystyrene; polymethylstyrene; isobutylene poly-mers; polyesters, such as poly/ethylene-co-alkylenebis-(alkyleneoxyaryl)-phenylenedicarboxylate7; phenolformal-dehyde resins; ketone resins; polyamides; polycarbonates;
polythiocarbonates; poly/ethylene-co-isopropylidene-2,2-bis(ethyleneoxyphenylene)terephthalat_7; copolymers of vinyl haloarylates; poly(ethylene-co-neopentyl terephthalate); and vinyl acetate such as poly(vinyl-m-bromobenzoate-co-vinyl acetate); etc.
Methods of making resins of this type have been described in the prior art, for example, styrene-alkyd resins can be prepared according to the method described in 30 U.S. Patent 2,361,019 and 2,258,~l23. Suitable resins of the type contemplated for use in the photoconductive layers of the invention are sold under such tradenames as Vite~ PE-101, Cymac~ Piccopal~100, Sara~ F-220 and Lexa~. Other types of binders which can be used in the photoconductive layers of the invention include such materials as paraf~ing mineral waxes 9 etc.
A variety of solvents are useful for preparing coating compositions of the binder photoconductors of the present invention. For example, benzene; toluene; acetone;
~ 7 2-butanone; chlorinated hydrocarbons such as methylene chlorlde; ethylene chloride; and the like; ethers~ such as tetrahydrofuran and the like, or mi~tures Or such solvents can advantageously be employed ln the practice of thls lnvention.
Coating thicknesses of the photoconductlve com-position on a support can vary wldely. Normally, a wet coating thickness in the range of about 0.025 mm to about 2.5 mm is useful in the practlce of the lnvention. A pre-ferred range of coating thickness is ~rom about 0.050 mmto about 0.15 mm before drying although such thicknesses can vary widely depending on the particular application deslred for the electrophotographic element.
Suitable supporting materials ~or the photocon-ductive layers of the present inventlon can lnclude anyelectrically conducting supports. Examples include conduct-ing papers, aluminum-paper lamlnates, metal foils such as aluminum and zinc folls; metal plates~ such as aluminum, copper, zlnc, brass and galvinlzed plates; vapor deposlted metal layer (silver, nickel, aluminum) on conventional rilm supports such as cellulose acetate, poly~ethylene terephthal-ate), polystyrene and the like.
An especially useful conducting support can be prepared by coating a transparent ~ilm-support such as poly(ethylene terephthalate) wlth a layer contalning a semiconductor dispersed ln a resin. A suitable conducting coating can be prepared ~rom the sodlum salt of a chrboxy-ester lactone of a maleic anhydride-vlnyl acetate copolymer or cuprous iodide or the llke. Such conductlng layers and 3 methods for thelr optimum preparation and use are dlsclosed ln U.S. Patents 3,007,901, 3,245,833 and 3~267,807.
The photoconductlve layers of the present lnvent~on can be employed in photoconductive elements use~ul in an electrophotographic process. In a process Or this type~ an 3~ elec~rophotographic element held in the dark, ls given a blanket positlve or negative e~ectrostatic charge as deslred 7 by placing lt under a corona discharge to glve a uniform charge to the sur~ace o~ the photoconductlve layer. Thls ~ z~
charge ls retalned by the layer owing to the aubstantial dark-lnsulatlng property o~ the layer. The electrostatlc charge formed on the surface of the photoconductive layer is then selectively dlssipated ~rom the ~ur~ace of the layer by 5 imagewlse exposure to light by means o~ a conventional exposure technlque to ~orm a latent elet-tr~statlc image on the photoconductive layer. Examples include contact-printing, lens pro~ection of an lmage~ or reflex or blreflex technlques and the like.
The charge pattern produced by exposure is then developed or transferred to another sur~ace and developed by treatment with a developlng composit~on comprislng electrostatically responsive partlcles havlng optical density. The developing composition ls in the rorm Or a 1, liquid dispersion, dust, or powder and generally comprlse a plgmented thermoplastic resin called a toner.
One method of applylng such a toner to a latent electrostatic image for solld area development i8 by the use of a magnetic brush such as descrlbed ln the rollowing U.S.
2~ Patents 2,786,439; 2,786,440; 2,78G,441; 2,811,465; 2,B74,063;
2,984,163; ~,040,704; 3,117,884 and Re. 25,779. In liquid developers the developing particles are carried to the lmage-bearing surface ln an electrically insulating liquid carrier. Methods of development of thls type are wldely 2~ known and have been descrlbed ~n U.S. Patent 2,297,691 and Australlan Patent 212,315.
The developed lmage can be flxed by heating the toned lmage. Heating causes the toner resln to melt or ~u6e lnto or on the image receiver element. In other cases, a 3 transfer of the charge image or toner image for~ed on the photoconductive layer can be made to a second support such as paper which would then become the final print after developlng and ~uslng. Technlques o~ thls type are well known in the art and have been described in a number o~ U.S
and foreign patentsJ such as U.S. Patents 2,297,691 and 2,551,582, and ln URCA Review"; Vol. 15 (1954) pages 469-484.
~-~z~
The organlc photoconductlve layers o~ the present lnventlon can be used ln electrophotographlc ele~ents having many structural varlatlons. For example, the layers can be ~ormed as slngle layers or as multlple layers on a sultable opaque or transparent conducting support. Likewise, the layers can be contlguous or spaced havlng layers of ln~ulat-lng materlal or other photoconductlve or ~ensltlzing materlal therebetween. Other conflgurations dlf~ering ~rom those disclosed hereln are also useful.
The followlng examples are included ~or a ~urther understanding of this inventlon.
Examples A standard thermal crystallizatlon or "snake" test conslsted of heating the electrophotographic element for one minute at 90C followed by storage of the film sample at room temperature and perlodically examlnlng the sample under 200X magnlfication. The time, ln days, weeks or months that the derect is first observed, is recorded. Thi~ test accelerates the crystalllzatlon of the organic photocon-ductor present ln the element. ~nder normal conditions theelement would only be sub~ected to this high a ~emperature during a 5-10 second fixatlon step.
Examples 1-4:
The electrophotographic element comprlsed a conductive support bearlng a photoconductive layer con-taining an electrically lnsulatlng polyester binder poly-[ethylene-co-isopropylidene-2,2-bis(ethylene oxyphenylene)-terephthalateJ, one or more organlc photoconductors 4-/~-butylamino7-2(p-methoxyphenyl) benzo/ b7 pyryllum rluoro-borate spectral sensltlzer and a polysi}oxane surfactant ofthe type described by Cawley in U.S. Patent 3,861,915. The organic photoconductor (OP) content of each element and the results o~ the thermal test are tabulated ln Table II.
t~ 7~P;Z
:~ td~ td O ~
tn s tn o tn 3 bO.~ bO
O v ~ ~ ~ C .~ tn ~V tQ ~ ~ ~ O
tdh O O C
h 3 ~
x e c O
bO.~ t~
C~
n C " ~
o CO ~ ~ , o ~
td u~ ~ U~ ~ ~ td O :q ~ ~1t~J t~J o ~~m ~ v O C .
v l S
¢ _ J~ t h ~
^~^~bO_--` 3~o tl~ --~bO~ bO t~ bD ~0 O td ~d -1:~ 0 h ~ to tx~ ~ ~o t~l tn o ~o b~ ~ ~ ~1 tY- ~-- td ~
r~ NIr~ t,~i ra a) ~ t.) nt~tr~t~~ E3 C
tn t~ td td t~ bO
h tn 3 oh td ~ d o o ~ 3 ,~
~
ed5~ ~1 t.~ t~
z Examples 5-6:
Aggregate photoconductive elements were rormed substantlally as described ln Light, U.S. Patent 3,615,414.
The elements comprised a contluctlng ~upport and an aggregate photoconductive layer containing a binder combination of bis phenol A polycarbonate (32% by ~elght based on blnder)~ a polyethylene-co-neopentyl terephthalate polyester res~n (8% by weight based on binder) one or more organic photoconductors and aggregate ~orming pyryllum sensitizers. The organlc photoconductor content of these aggregate photoconductive layers and the results Or the thermal test are tabulated ln Table III.
:~
D~ O
~_ S U~
~0 ~1 h ~ 3~
O J~ ~ "_ ~ ~ 0 S~ ~ ~ ~ ~ ~
a._I ~ a, ~1 ~1 ~ ~1 Dq 0 h h ~ ~ ~ ~ O
CS ~ O
~C
a~
a~ ~
h W S Z
,_ ~ h O C O S bl~
~ O ~
,1 a) h o o ~1 0 ~ 3 3 Co bl~
H~ a:l C V, C OZ
U~
,~ S
W ~0 bl) bO h H ,~ O O O O ~ ~
O N _ _ _ C V
ol o ,_ ~ a~
0~'0 ~ o o (D~ 01 a) ~ Z u~ ~D
3~
Although the invention has been described ln considerable detail with partlcular reference to certain pre~erred embodiments thereor, varlatlons and modl~ic~ti~ns can be effected within the splrit nd scope of the lnventlon.
~lectrophotographlc elements comprising the photoconductlve layers of the ~nventlon can be prepared with the photoconducting compounds Or Formula I ln the usual manner, for an example, by blending a dlspersion or solutlon of the selected photoconductors together wlth an electrically insulating binder, and then coating or formin6 a self-support1ng layer of the dispersion or solution. Each Or theorganic photoconductors selected may be included ln the layer up to the solubility limit of each in the binder.
The total amount Or organlc photoconductors in-cluded ln the layer may vary widely but preferably ranges from about 5 to about 40 wel~ht percent based on the total dry weight of the lay~r. The solubllity of each organic photoconductor may be determined by evaluating an organic photoconductor eries in a rilm rorming blnder and determln-lng by dif~erentlal thermal analysis at what conçentrat~Dn the organic photoconductor ~orms a separate phase.
~2~7~;~
The photoconductive layers Or the invention can also be spectrally and/or chemically sensitized by the additlon of effective amounts of sensikizlng compounds.
Sensitizing compounds useful with the photoconductiYe 5 comyounds of the present invention can be elected from a wlde varlety of materials, includlng ~uch materl~ls s pyrylium dye salts including thlapyrylillm dye ~alts and selenapyrylium dye salts disclosed in VanAllan et al, U.S.
Patent 3,250,615; fluorenes; aggregate-type sensitlzers of the type described in U.S. Patent 3~615,414; aromatic nltro compounds of the kind described in U.S. Patent 2,610V120;
anthrones like those disclosed ln ~.S. Patent 2,670,284;
quinones, U.S. Patent 2~670,286; benzophenones, ~.S. Patent 2,670,287; thiazoles, U.S. Patent 2,732,301; mineral aclds;
1~ carboxylic acids such as maleic acid, di- and tri-chloro-acetlc acids, and salicyclic acid; sulfonic and phosphorlc acids; and varlous dyes, such as cyan1ne (lncludlng carbo-cyanlne), merocyanlne, diarylmethane, thlazlne, azine, oxazine, xanthene, phthaleln, acrldlne, azo, anthraquinone dyes and the like and mixtures thereo~. The æensltlzers preferred for use with the compounds Or this lnventlon are selected from pyrylium salts lncluding selenapyryllum ~altæ
and thiapyrylium salts, and cyanlne dyes including carbo-cyanine dyes such as dlsclosed in U.S. Patent 3,597~196.
2~ Where a sensitlzing compound is employed with the binder and organic photoconductors to ~orm a photoconductive layer, a suitable amount of the sensitizlng compound may be mlxed with the coating composition so that, after thorough mlxing, the sensitlzing coMpound i5 uniformly distrlbuted in 3D the coated element. Other methods of incorporating the sensitizer may, howe~er, be employed conslstent with the practice of this invention.
The amount Or ~ens~tlzer that can be added ~o the organic photoconductor layer to give effectlve increaæe~
3~ in speed can vary widely. The optimum concentration ln any given case ~ill vary wlth the ~peclfic photoconductors and senslt~zing compound used. In general3 ~ubstantial speed gains can be obtained where an appropriate sensitlzer is added in a concentration range from about 0.0001 to about 30 percent by weight based on the total dry weight of the photoconductive layer. Normally, a sensitlzer is added in an amount by weight Or from about 0.005 to about 5.0 percent by weight.
Preferred electrically insulating binders for use in preparing the present organic photoconductive layers are film-forming, hydrophobic polymeric binclers having fairly high dielectric strength. Materials of this type comprise styrene-butadiene copolymers, silicone resins; styrene-alkyd resins; silicone-alkyd resins; soya-alkyd resins; poly(vinyl chloride); poly(vinylidene chloride); vinylidene chloride-acrylonitrile copolymers; poly(vinyl acetate); vinyl acetate-vinyl chloride copolymers; poly(vinyl acetals), such as poly(vinyl butyral); polyacrylic and polymethacrylic esters 9 such as poly(methyl methacrylate), poly(n-butyl methacry-late), poly(isobutyl methacrylate), etc.; polystyrene;
nitrated polystyrene; polymethylstyrene; isobutylene poly-mers; polyesters, such as poly/ethylene-co-alkylenebis-(alkyleneoxyaryl)-phenylenedicarboxylate7; phenolformal-dehyde resins; ketone resins; polyamides; polycarbonates;
polythiocarbonates; poly/ethylene-co-isopropylidene-2,2-bis(ethyleneoxyphenylene)terephthalat_7; copolymers of vinyl haloarylates; poly(ethylene-co-neopentyl terephthalate); and vinyl acetate such as poly(vinyl-m-bromobenzoate-co-vinyl acetate); etc.
Methods of making resins of this type have been described in the prior art, for example, styrene-alkyd resins can be prepared according to the method described in 30 U.S. Patent 2,361,019 and 2,258,~l23. Suitable resins of the type contemplated for use in the photoconductive layers of the invention are sold under such tradenames as Vite~ PE-101, Cymac~ Piccopal~100, Sara~ F-220 and Lexa~. Other types of binders which can be used in the photoconductive layers of the invention include such materials as paraf~ing mineral waxes 9 etc.
A variety of solvents are useful for preparing coating compositions of the binder photoconductors of the present invention. For example, benzene; toluene; acetone;
~ 7 2-butanone; chlorinated hydrocarbons such as methylene chlorlde; ethylene chloride; and the like; ethers~ such as tetrahydrofuran and the like, or mi~tures Or such solvents can advantageously be employed ln the practice of thls lnvention.
Coating thicknesses of the photoconductlve com-position on a support can vary wldely. Normally, a wet coating thickness in the range of about 0.025 mm to about 2.5 mm is useful in the practlce of the lnvention. A pre-ferred range of coating thickness is ~rom about 0.050 mmto about 0.15 mm before drying although such thicknesses can vary widely depending on the particular application deslred for the electrophotographic element.
Suitable supporting materials ~or the photocon-ductive layers of the present inventlon can lnclude anyelectrically conducting supports. Examples include conduct-ing papers, aluminum-paper lamlnates, metal foils such as aluminum and zinc folls; metal plates~ such as aluminum, copper, zlnc, brass and galvinlzed plates; vapor deposlted metal layer (silver, nickel, aluminum) on conventional rilm supports such as cellulose acetate, poly~ethylene terephthal-ate), polystyrene and the like.
An especially useful conducting support can be prepared by coating a transparent ~ilm-support such as poly(ethylene terephthalate) wlth a layer contalning a semiconductor dispersed ln a resin. A suitable conducting coating can be prepared ~rom the sodlum salt of a chrboxy-ester lactone of a maleic anhydride-vlnyl acetate copolymer or cuprous iodide or the llke. Such conductlng layers and 3 methods for thelr optimum preparation and use are dlsclosed ln U.S. Patents 3,007,901, 3,245,833 and 3~267,807.
The photoconductlve layers of the present lnvent~on can be employed in photoconductive elements use~ul in an electrophotographic process. In a process Or this type~ an 3~ elec~rophotographic element held in the dark, ls given a blanket positlve or negative e~ectrostatic charge as deslred 7 by placing lt under a corona discharge to glve a uniform charge to the sur~ace o~ the photoconductlve layer. Thls ~ z~
charge ls retalned by the layer owing to the aubstantial dark-lnsulatlng property o~ the layer. The electrostatlc charge formed on the surface of the photoconductive layer is then selectively dlssipated ~rom the ~ur~ace of the layer by 5 imagewlse exposure to light by means o~ a conventional exposure technlque to ~orm a latent elet-tr~statlc image on the photoconductive layer. Examples include contact-printing, lens pro~ection of an lmage~ or reflex or blreflex technlques and the like.
The charge pattern produced by exposure is then developed or transferred to another sur~ace and developed by treatment with a developlng composit~on comprislng electrostatically responsive partlcles havlng optical density. The developing composition ls in the rorm Or a 1, liquid dispersion, dust, or powder and generally comprlse a plgmented thermoplastic resin called a toner.
One method of applylng such a toner to a latent electrostatic image for solld area development i8 by the use of a magnetic brush such as descrlbed ln the rollowing U.S.
2~ Patents 2,786,439; 2,786,440; 2,78G,441; 2,811,465; 2,B74,063;
2,984,163; ~,040,704; 3,117,884 and Re. 25,779. In liquid developers the developing particles are carried to the lmage-bearing surface ln an electrically insulating liquid carrier. Methods of development of thls type are wldely 2~ known and have been descrlbed ~n U.S. Patent 2,297,691 and Australlan Patent 212,315.
The developed lmage can be flxed by heating the toned lmage. Heating causes the toner resln to melt or ~u6e lnto or on the image receiver element. In other cases, a 3 transfer of the charge image or toner image for~ed on the photoconductive layer can be made to a second support such as paper which would then become the final print after developlng and ~uslng. Technlques o~ thls type are well known in the art and have been described in a number o~ U.S
and foreign patentsJ such as U.S. Patents 2,297,691 and 2,551,582, and ln URCA Review"; Vol. 15 (1954) pages 469-484.
~-~z~
The organlc photoconductlve layers o~ the present lnventlon can be used ln electrophotographlc ele~ents having many structural varlatlons. For example, the layers can be ~ormed as slngle layers or as multlple layers on a sultable opaque or transparent conducting support. Likewise, the layers can be contlguous or spaced havlng layers of ln~ulat-lng materlal or other photoconductlve or ~ensltlzing materlal therebetween. Other conflgurations dlf~ering ~rom those disclosed hereln are also useful.
The followlng examples are included ~or a ~urther understanding of this inventlon.
Examples A standard thermal crystallizatlon or "snake" test conslsted of heating the electrophotographic element for one minute at 90C followed by storage of the film sample at room temperature and perlodically examlnlng the sample under 200X magnlfication. The time, ln days, weeks or months that the derect is first observed, is recorded. Thi~ test accelerates the crystalllzatlon of the organic photocon-ductor present ln the element. ~nder normal conditions theelement would only be sub~ected to this high a ~emperature during a 5-10 second fixatlon step.
Examples 1-4:
The electrophotographic element comprlsed a conductive support bearlng a photoconductive layer con-taining an electrically lnsulatlng polyester binder poly-[ethylene-co-isopropylidene-2,2-bis(ethylene oxyphenylene)-terephthalateJ, one or more organlc photoconductors 4-/~-butylamino7-2(p-methoxyphenyl) benzo/ b7 pyryllum rluoro-borate spectral sensltlzer and a polysi}oxane surfactant ofthe type described by Cawley in U.S. Patent 3,861,915. The organic photoconductor (OP) content of each element and the results o~ the thermal test are tabulated ln Table II.
t~ 7~P;Z
:~ td~ td O ~
tn s tn o tn 3 bO.~ bO
O v ~ ~ ~ C .~ tn ~V tQ ~ ~ ~ O
tdh O O C
h 3 ~
x e c O
bO.~ t~
C~
n C " ~
o CO ~ ~ , o ~
td u~ ~ U~ ~ ~ td O :q ~ ~1t~J t~J o ~~m ~ v O C .
v l S
¢ _ J~ t h ~
^~^~bO_--` 3~o tl~ --~bO~ bO t~ bD ~0 O td ~d -1:~ 0 h ~ to tx~ ~ ~o t~l tn o ~o b~ ~ ~ ~1 tY- ~-- td ~
r~ NIr~ t,~i ra a) ~ t.) nt~tr~t~~ E3 C
tn t~ td td t~ bO
h tn 3 oh td ~ d o o ~ 3 ,~
~
ed5~ ~1 t.~ t~
z Examples 5-6:
Aggregate photoconductive elements were rormed substantlally as described ln Light, U.S. Patent 3,615,414.
The elements comprised a contluctlng ~upport and an aggregate photoconductive layer containing a binder combination of bis phenol A polycarbonate (32% by ~elght based on blnder)~ a polyethylene-co-neopentyl terephthalate polyester res~n (8% by weight based on binder) one or more organic photoconductors and aggregate ~orming pyryllum sensitizers. The organlc photoconductor content of these aggregate photoconductive layers and the results Or the thermal test are tabulated ln Table III.
:~
D~ O
~_ S U~
~0 ~1 h ~ 3~
O J~ ~ "_ ~ ~ 0 S~ ~ ~ ~ ~ ~
a._I ~ a, ~1 ~1 ~ ~1 Dq 0 h h ~ ~ ~ ~ O
CS ~ O
~C
a~
a~ ~
h W S Z
,_ ~ h O C O S bl~
~ O ~
,1 a) h o o ~1 0 ~ 3 3 Co bl~
H~ a:l C V, C OZ
U~
,~ S
W ~0 bl) bO h H ,~ O O O O ~ ~
O N _ _ _ C V
ol o ,_ ~ a~
0~'0 ~ o o (D~ 01 a) ~ Z u~ ~D
3~
Although the invention has been described ln considerable detail with partlcular reference to certain pre~erred embodiments thereor, varlatlons and modl~ic~ti~ns can be effected within the splrit nd scope of the lnventlon.
Claims (11)
1. An electrophotographic element compris-ing a conductive support and an organic photoconduc-tive layer containing a crystallization-inhibiting mixture of at least two different organic photocon-ductors selected from the class of organic photocon-ductors represented by the formula:
wherein:
R is selected from the group consisting of alkyl, aralkyl and substituted and unsubstituted aryl;
X and X1, which may be the same or differ-ent, are selected from the grup consisting of hydrogen, alkyl, alkoxy, hydroxyl, N02 and halogen;
Y and y1, which may be the same or differ-ent, are selected from the goup consisting of hydrogen, alkyl, alkoxy, hydroxyl, halogen and N02;
with the proviso that at least one of X, Y, X1 and Y1 in at least one of said photocon-ductors is alkyl; and A and B, which when taken alone may be the same or different, are selected from the group consisting of hydrogen, alkoxy, hydroxyl, halo-gen, substituted or unsubstituted aryl, alkyl, cycloalkyl having 4 to 10 carbon atoms, and cycloalkenyl having 4 to 8 carbon atoms; or A and B, when taken together, represent sufficient atoms to form, together with the car-bon to which they are attached, a substituted or unsubstituted carbocyclic ring having from 4 to 10 carbon atoms;
wherein each organic photoconductor may by pres-ent in said layer up to the limit of its solubility in the binder; and wherein A and/or B in at least one of said pho-toconductors is substituted or unsubstituted aryl.
wherein:
R is selected from the group consisting of alkyl, aralkyl and substituted and unsubstituted aryl;
X and X1, which may be the same or differ-ent, are selected from the grup consisting of hydrogen, alkyl, alkoxy, hydroxyl, N02 and halogen;
Y and y1, which may be the same or differ-ent, are selected from the goup consisting of hydrogen, alkyl, alkoxy, hydroxyl, halogen and N02;
with the proviso that at least one of X, Y, X1 and Y1 in at least one of said photocon-ductors is alkyl; and A and B, which when taken alone may be the same or different, are selected from the group consisting of hydrogen, alkoxy, hydroxyl, halo-gen, substituted or unsubstituted aryl, alkyl, cycloalkyl having 4 to 10 carbon atoms, and cycloalkenyl having 4 to 8 carbon atoms; or A and B, when taken together, represent sufficient atoms to form, together with the car-bon to which they are attached, a substituted or unsubstituted carbocyclic ring having from 4 to 10 carbon atoms;
wherein each organic photoconductor may by pres-ent in said layer up to the limit of its solubility in the binder; and wherein A and/or B in at least one of said pho-toconductors is substituted or unsubstituted aryl.
2. In an electrophotographic process wherein the photoconductive layer of a photoconduc-tive element is electrostatically charged, imagewise-exposed to light to form an electrostatic charge pattern, and developed to form an image, the improvement wherein said photoconductive layer com-prises a crystallization-inhibiting mixture of at least two different organic photoconductors selected from the class of organic photoconductors repre-sented by the formula:
wherein:
R is selected from the group consisting of alkyl, aralkyl and substituted and unsubstituted aryl;
X and X1, which may be the same or differ-ent, are selected from the grup consisting of hydrogen, alkyl, alkoxy, hydroxyl, N02 and halogen;
Y and Y1, which may be the same or differ-ent, are selected from the goup consisting of hydrogen, alkyl, alkoxy, hydroxyl, halogen and NO2;
with the proviso that at least one of X, Y, X1 and Y1 in at least one of said photocon-ductors is alkyl; and A and B, which when taken alone may be the same or different, are selected from the group consisting of hydrogen, alkoxy, hydroxyl, halo-gen, substituted or unsubstituted aryl, alkyl, cycloakyl having 4 to 10 carbon atoms, and cycloakenyl having 4 to 8 carbon atoms; or A and B when taken together, represent sufficient atoms to form, together with the car-bon to which they are attached, a substituted or unsubstituted carbocyclic ring having from 4 to 10 carbon atoms;
wherein each organic photoconductor may be pres-sent in said layer up to the limit of its solubility in the binder; and wherein A and/or B in at least one of said pho-toconductors is substituted or unsubstituted aryl.
wherein:
R is selected from the group consisting of alkyl, aralkyl and substituted and unsubstituted aryl;
X and X1, which may be the same or differ-ent, are selected from the grup consisting of hydrogen, alkyl, alkoxy, hydroxyl, N02 and halogen;
Y and Y1, which may be the same or differ-ent, are selected from the goup consisting of hydrogen, alkyl, alkoxy, hydroxyl, halogen and NO2;
with the proviso that at least one of X, Y, X1 and Y1 in at least one of said photocon-ductors is alkyl; and A and B, which when taken alone may be the same or different, are selected from the group consisting of hydrogen, alkoxy, hydroxyl, halo-gen, substituted or unsubstituted aryl, alkyl, cycloakyl having 4 to 10 carbon atoms, and cycloakenyl having 4 to 8 carbon atoms; or A and B when taken together, represent sufficient atoms to form, together with the car-bon to which they are attached, a substituted or unsubstituted carbocyclic ring having from 4 to 10 carbon atoms;
wherein each organic photoconductor may be pres-sent in said layer up to the limit of its solubility in the binder; and wherein A and/or B in at least one of said pho-toconductors is substituted or unsubstituted aryl.
3. An electrophotographic layer comprising an electrically insulating binder and a crystallization-inhibiting mixture of at least two different organic photoconductors selected from the class of organic photoconductors represented by the formula:
wherein:
R is selected from the group consisting of alkyl, aralkyl and substituted and unsubstituted aryl;
X and X1, which may be the same or differ-ent, are selected from the grup consisting of hydrogen, alkyl, alkoxy, hydroxyl, NO2 and halogen;
Y and Y1, which may be the same or differ-ent, are selected from the goup consisting of hydrogen, alkyl, alkoxy, hydroxyl, halogen and NO2;
with the proviso that at least one of X, Y, X1 and Y1 in at least one of said photocon-ductors is alkyl; and A and B, which when taken alone may be the same or different, are selected from the group consisting of hydrogen, alkoxy, hydroxyl, halo-gen, substituted or unsubstituted aryl, alkyl, cycloalkyl having 4 to 10 carbon atoms, and cycloalkenyl having 4 to 8 carbon atoms; or A and B, when taken together) represent sufficient atoms to form, together with the car-bon to which they are attached, a substituted or unsubstituted carbocyclic ring having from 4 to 10 carbon atoms;
wherein each organic photoconductor may be pres-ent in said layer up to the limit of its solubility in the binder, and wherein A and/or B in at least one of said pho-toconductors is substituted or unsubstituted aryl.
wherein:
R is selected from the group consisting of alkyl, aralkyl and substituted and unsubstituted aryl;
X and X1, which may be the same or differ-ent, are selected from the grup consisting of hydrogen, alkyl, alkoxy, hydroxyl, NO2 and halogen;
Y and Y1, which may be the same or differ-ent, are selected from the goup consisting of hydrogen, alkyl, alkoxy, hydroxyl, halogen and NO2;
with the proviso that at least one of X, Y, X1 and Y1 in at least one of said photocon-ductors is alkyl; and A and B, which when taken alone may be the same or different, are selected from the group consisting of hydrogen, alkoxy, hydroxyl, halo-gen, substituted or unsubstituted aryl, alkyl, cycloalkyl having 4 to 10 carbon atoms, and cycloalkenyl having 4 to 8 carbon atoms; or A and B, when taken together) represent sufficient atoms to form, together with the car-bon to which they are attached, a substituted or unsubstituted carbocyclic ring having from 4 to 10 carbon atoms;
wherein each organic photoconductor may be pres-ent in said layer up to the limit of its solubility in the binder, and wherein A and/or B in at least one of said pho-toconductors is substituted or unsubstituted aryl.
4. A layer according to Claim 3 wherein A
and/or B in at least one of said photoconductors is substituted or unsubstituted phenyl.
and/or B in at least one of said photoconductors is substituted or unsubstituted phenyl.
5. A layer according to Claim 3 wherein the organic photoconductors are bis(4-N,N-dlethyl-amino-2-methylphenyl)-4-methylphenylmethane, 1,1-bis(4-N,N-diethylamino-2-methylphenyl)-2-methylpro-pane and 4,4'-bis(diethylamino)-2,2'-dimethyltri-phenylmethane.
6. A layer according to Claims 3, 4 or 5 wherein the total amount of all organic photoconduc-tors present in said layer is from 5 to about 40 percent by weight.
7. A layer according to Claims 3, 4 or 5 wherein the mixture of organic photoconductors is included in an aggregate photoconductive layer.
8. A layer according to Claims 3, 4 or 5 wherein each organic photoconductor is present in said layer in equal amounts.
g. A layer according to Claims 3, 4 or 5 wherein the binder is selected from the group con-sisting of bisphenol A polycarbonate and poly[ethyl-ene-co-isopropylidene-2,2-bis(ethyleneoxyphenyLene)-terephthalAte.
10. A layer according to Claims 3, 4 or 5 which also includes a triphenylamine-type photocon-ductor.
11. A layer according to Claims 3, 4 or 5 which also includes tri-p-tolylamine.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US96243378A | 1978-11-20 | 1978-11-20 | |
| US962,433 | 1978-11-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1129702A true CA1129702A (en) | 1982-08-17 |
Family
ID=25505860
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA338,119A Expired CA1129702A (en) | 1978-11-20 | 1979-10-22 | Photoconductive layer containing a crystallization inhibiting mixture of aryl-substituted methanes |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0011980B1 (en) |
| JP (1) | JPS5577745A (en) |
| CA (1) | CA1129702A (en) |
| DE (1) | DE2966859D1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1226871A (en) * | 1981-11-10 | 1987-09-15 | Everett W. Bennett | Organic photoconductors having improved pre-exposure fatigue resistance and blooming properties |
| US5780194A (en) | 1995-04-18 | 1998-07-14 | Mita Industrial Co., Ltd. | Electrophotosensitive material |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR84976E (en) * | 1960-02-19 | 1965-05-21 | Gevaert Photo Prod Nv | Electrophotographic material |
| NL274848A (en) * | 1961-02-16 | |||
| US3291600A (en) * | 1963-01-14 | 1966-12-13 | Rca Corp | Electrophotographic recording element and method of making |
| GB1051201A (en) * | 1963-02-26 | |||
| BE756375A (en) * | 1969-09-30 | 1971-03-01 | Eastman Kodak Co | NEW PHOTOCONDUCTIVE COMPOSITION AND PRODUCT CONTAINING IT FOR USE IN ELECTROPHOTOGRAPHY |
| US3660083A (en) * | 1970-06-25 | 1972-05-02 | Eastman Kodak Co | Polyarylalkane-terminated, solvent-resistant polycarbonate resins as photoconductors |
| US3679406A (en) * | 1970-11-13 | 1972-07-25 | Eastman Kodak Co | Heterogeneous photoconductor composition formed by low-temperature conditioning |
-
1979
- 1979-10-22 CA CA338,119A patent/CA1129702A/en not_active Expired
- 1979-11-20 JP JP15056279A patent/JPS5577745A/en active Granted
- 1979-11-20 DE DE7979302648T patent/DE2966859D1/en not_active Expired
- 1979-11-20 EP EP79302648A patent/EP0011980B1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| EP0011980A1 (en) | 1980-06-11 |
| DE2966859D1 (en) | 1984-05-03 |
| EP0011980B1 (en) | 1984-03-28 |
| JPS5577745A (en) | 1980-06-11 |
| JPS639213B2 (en) | 1988-02-26 |
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