DE4134987A1 - ACID ADDITIVES FOR IMPROVING THE BACKUP TRANSMISSION IN POSITIVE LIGHT-SENSITIVE ELECTROSTATIC ORIGINALS - Google Patents

Description

This invention relates to a photosensitive elek Trost original. In particular, this relates Invention, a photosensitive electrostatic Ori ginal, which is capable of one single image sen exposure to produce positive images. Quite be In particular, this invention relates to a positive, light delicate electrostatic original with improved th reverse transfer properties.

Photopolymerizable compositions and films or Basic components, the binder, monomer, initiator and chain transfer agent are commercially available available. An important application for such pho topolymerizable base components is on the Ge area of graphic art. Basic components that sol che photopolymerizable layers are included currently as electrostatic originals to the analog Color proofing is used and considered as promising materials for the future For applications of the digital color proof  to be developed. For use with The analog color proofing becomes a photo polymerizable layer on an electrically conductive Substrate applied and with an ultraviolet (UV) - Light source through a halftone color separation negative kon Diplomatic exposed. The photopolymerizable composition cures in the illuminated with the ultraviolet source th areas due to the polymerization and remains the other places in the unexposed liquid-like state. The viscosity differences between The exposed and unexposed areas are located in the transport properties clearly, d. h., the unbe light-cured photopolymerizable areas conduct elek trostatic loads, while the exposed areas are non-conductive. By the action of a corona Entla tion on the image-wise exposed photopolymerized Basic component becomes a latent electrostatic Image obtained from electrostatic charges exists only in the non-conductive or be exposed areas of the basic component are. This latent image can then be applied by applying of an electrostatic toner on the surface ent be wrapped. Does the toner have opposite charge with respect to the corona charge, then the toner adheres selectively on the exposed or polymerized Be range from the photopolymerized base component.

There will be photocurable electrostatic originals be which in terms of imaging characteristics equal to a printing press. They are electrostatic known originals, where the conductivity both the exposed and the unexposed Be can be controlled by the fact that in the photopolymerizable composition electron donor  or electron acceptor molecules are introduced, the electrical properties of the composition change and bring a point gain that the similar to those achieved with a printing press.

Although the use of photopolymerizable compositions been demonstrated in electrophotography wur de, and many preparations can be imaged it did not seem possible to use a photopolymerizable to produce electrostatic original, with both positive as well as negative images can be generated NEN. Such results were achieved with light-curing Baren basic components, which have a conductive support which has a photohardenable layer polymeric binder, a compound with at least an ethylenically unsaturated group, an initia tor, a photoinhibitor and at least one sensibi dissolving compound. Depending on the exposure sequence and exposure wavelength become positive and negative achieved scores. Such basic components are extremely useful because a single basic component is the Needs of all printers at the proof shop irrespective of whether they are now negati ver or positive color separation work. A disadvantage This basic component is that they have two exposures need to get a positive working, electrostatic nice original to deliver.

In electrophotography, a photoconductive Layer loaded, and imagewise exposure leads to local charge drop, so that the applied toner or developers in the unexposed areas is withdrawn. Electrophotographic devices are in the universe Common designed so that the conductive layer at discharging locally and the toner is discharged  then it is applied. After the transfer of the toner the photoconductive layer is cleaned. One needs many copies, so the steps loading, exposing, Toning and transmitting repeatedly. Virtually everyone put deduction is at least slightly different from the other, because the image quality by entering Changes in loading and light intensity affected becomes.

These are photosensitive electrostatic originals known to be a conductive carrier and a light sensitive layer with the following photosensitive Composition include:

• (A) at least one organic polymeric binder,
• (B) a hexaarylbiimidazole photooxidant,
• (C) a leuco dye extending through the photooxi oxidizing agent to an ionic species leaves,
• (D) a nonionic halogenated compound, and
• (E) a compatible plasticizer,

where a single exposure is a positive one electrostatic original supplies. This basic comp nente also provides a print that is visual Determination with regard to exposure of the basic component allowed and double exposure of the basic component, the otherwise could occur. The light temp sensitive electrostatic original can after a single exposure many times charged, toned, gela which are toned, etc., with permanent image duplicates arise. However, it has been found that these origins nale problems with the retransfer Multi-layer transmissions are connected.

It has been found that this disadvantage remedy that the photosensitive composition  tion of the photosensitive described above electrostatic single exposure original as an acid Additive, as defined below added. The Photosensitive electrostatic according to the invention Originals have improved reverse transfer characteristics on and can po with a single exposure generate positive images.

According to the present invention, a high-resolution, Photosensitive electrostatic original available made, the case of imagewise exposure conductive be formed image areas, where the original one electrically conductive substrate comprising a layer a photosensitive composition which in the essential consists of:

• (A) At least one organic polymeric binder medium,
• (B) a hexaarylbiimidazole photooxidant,
• (C) a leuco dye, extending through the photo oxidizing agent to an ionic species oxi dieren,
• (D) a nonionic halogenated compound,
• (E) at least one compatible plasticizer, and
• (F) at least one acidic additive selected from the group consisting of:
  • (1) Compounds of the general formula R-NH-R'worin is;
    R 'H, alkyl having 1 to 12 carbon atoms, aryl having 6 to 30 carbon atoms, substituted alkyl having 1 to 12 carbon atoms, substituted aryl having 6 to 30 carbon atoms, Halogen or a heterocyclic group;
    R and R taken together may form a 5- to 6-membered heterocyclic ring; R¹, R² and R³ may be the same or different and alkyl having 1 to 12 carbon atoms, aryl having 6 to 30 carbon atoms, substituted alkyl having 1 to 12 carbon atoms, substituted aryl having 6 to 30 carbon atoms , Acyl, halogen or a heterocyclic group;
  • (2) phosphonic acids of the general formula: wherein R⁴ is alkyl of 1 to 12 carbon atoms, aryl of 6 to 30 carbon atoms, substituted alkyl of 1 to 12 carbon atoms, substituted aryl of 6 to 30 carbon atoms, halogen or a heterocyclic group;
  • (3) carboxylic acids which are more acidic than acetic acid;
  • (4) sulfonic acids of the general formula: wherein R⁵ is alkyl of 1 to 12 carbon atoms, aryl of 6 to 30 carbon atoms, substituted alkyl of 1 to 12 carbon atoms, substituted aryl of 6 to 30 carbon atoms, halogen or a heterocyclic group;
  • (5) inorganic acids, and
  • (6) Lewis acids.

According to another embodiment of the present invention Invention is a Xerodruckverfahren for production positive images by a single imagewise Be exposure, including the steps:

• (a) imagewise exposing a photosensitive electrostatic original to actinic radiation, the original comprising an electrically conductive substrate carrying a photosensitive composition layer consisting essentially of:
  • (A) at least one organic polymeric binder,
  • (B) a hexaarylbiimidazole photooxidant,
  • (C) a leuco dye which can be oxidized by the photo oxidant to an ionic species,
  • (D) a nonionic halogenated compound,
  • (E) at least one compatible plasticizer, and
  • (F) at least one acidic additive selected from the group consisting of:
    • (1) Compounds of the general formula R-NH-R'worin is;
      R 'H, alkyl having 1 to 12 carbon atoms, aryl having 6 to 30 carbon atoms, substituted alkyl having 1 to 12 carbon atoms, substituted aryl having 6 to 30 carbon atoms, Halogen or a heterocyclic group;
      R and R taken together can form a 5- to 6-membered heterocyclic ring; R¹, R² and R³ may be the same or different and alkyl having 1 to 12 carbon atoms, aryl having 6 to 30 carbon atoms, substituted alkyl having 1 to 12 carbon atoms, substituted aryl having 6 to 30 carbon atoms , Acyl, halogen or a heterocyclic group;
    • (2) phosphonic acids of the general formula: wherein R⁴ is alkyl of 1 to 12 carbon atoms, aryl of 6 to 30 carbon atoms, substituted alkyl of 1 to 12 carbon atoms, substituted aryl of 6 to 30 carbon atoms, halogen or a heterocyclic group;
    • (3) carboxylic acids which are more acidic than acetic acid;
    • (4) sulfonic acids of the general formula: wherein R⁵ is alkyl of 1 to 12 carbon atoms, aryl of 6 to 30 carbon atoms, substituted alkyl of 1 to 12 carbon atoms, substituted aryl of 6 to 30 carbon atoms, halogen or a heterocyclic group;
    • (5) inorganic acids, and
    • (6) Lewis acids.
• (b) Electrostatic charge the original by one latent image of electrostatic charges in the to form unexposed areas  
• (c) developing the latent image by applying an oppositely charged electrostatic Toner or developer, and
• (d) transfer the toned or developed image on a receiver surface.

In this description have the following together the following terms mean:

In the appended claims in the appended "consisting essentially of" that the composition the photosensitive layer of the electrostatic Originals unspecified ingredients are not enough concludes that the realization of the benefits of light-sensitive electrostatic original prevent. For example, in addition to the pri components include coinitiators, sensitizers tel for visible light, thermal stabilizers or Thermo-inhibitors, absorbents for ultraviolet Light, coating aids, modifiers for the electrical properties, eg. B. electron acceptors, Electron donors, etc. be present.

The invention is based on the discovery that lichtemp sensitive layers on conductive supports, which in the we sentlichen from the components described above (A) to (F) are capable of generating posi tive electrostatic images with a single Be a visible printed image, and also have better retransmission. The Photosensitive layer is not photopolymerizable bar.  

Suitable binders (A) include: acrylate and methacrylate polymers and co- or terpolymers, e.g. B. Poly (methyl methacrylate), poly (ethyl methacrylate), poly (isobutyl methacrylate), etc .; Vinyl polymers and copoly mers, poly [styrene (70) / methyl methacrylate (30)], Arcrylni tril / butadiene / styrene, polystyrene, etc .; Polyvinylaceta le, z. Poly (vinyl acetal), poly (vinyl formal), etc .; Polyester, e.g. For example, poly (tetramethylene terephthalate), etc .; Condensation polymers, e.g. As polycarbonates, polysulfones, Polyetherimides, polyphenylene oxides, poly (1,4-cyclohexane dimethanol terephthalate), etc .; Butadiene copolymers, z. Styrene / butadiene copolymers, etc .; Celluloseester and ethers, e.g. Ethylcellulose, etc .; and polyurethanes. In preparations with improved margin at Um Influences of the world can be the choice of a polymer Bind to his Tg. The Tg of a poly mers is derived from the chemical structure of the main chain and the page groups affected. Polymers with rigid Structures generally show high Tgs while more flexible polymers have low Tgs. polymers with the desired Tg can be obtained by Copolymerization of the right combination of "rigid and flexible "monomer. The following publication, the a summary of the glass transition temperatures of homopolymers known in the literature, "POLYMER HANDBOOK ", ed. J. Brandrup & E.H. Immergut, John Wiley & Sons, Inc., New York, NY, 1975, is here through Quote introduced. Section III-140-192 of said Publi cation gives a compilation of the Tgs of most known polymers.

Preferred binders include the Elvacite® Resins, as their Tgs in the range of 15 ° C to 110 ° C lie The low Tg resins include: poly (ethyl methacrylate) (Tg 70 ° C), Elcacite® 2045 or 2042  in combination with high Tg resins, where poly (methyl methacrylate) (Tg 110 ° C) or poly (styrene / methyl meth acrylate) (Tg 95 ° C) are particularly preferred. By Ver broadening of the Tg range using combinations of Binders of high and low Tg are achieved ver improved stability against environmental influences. The mixed binders should have a specific Resistance in the order of 10¹⁴ to 10²⁰ Ω · cm, preferably 10¹⁴ to 10¹⁶ Ω · cm have.

Examples of hexaarylbiimidazole photooxidants (B) are 2,2 ', 4,4', 5,5'-hexaarylbiimidazoles, sometimes as 2,4,5-triarylimidazolyl dimers also called geläu fig as HABI, when exposed to actinic radiation forming the corresponding free triarylimida dissociate zolyl radicals. Every 2-o-substituted HABI, including those in the below US patents, is useful for the invention photosensitive compositions. Let the HABIs represented by the general formula:

wherein the Rs are aryl radicals, e.g. Phenyl, Naphthyl, preferably phenyl radicals, the substitu can be, as in US Patent 37 84 557, column 2, Row 20 to Column 3, Row 67 and Column 23, Row 53 to 74, the disclosures of which are described here Quote were introduced. 2-o-substituted HABIs those in which the aryl radicals are in positions 2  and 2 'are ortho-substituted. The remaining positions on the aryl radicals may be unsubstituted or carry any substituent that promotes dissociation the HABI does not interfere with exposure or electrical or other properties of the photosensitive Sy stems negatively affected. Also, mixtures of HABIs are usable. Preferred HABIs are 2-o-chloro-substituted Hexa-phenylbiimidazole, in which the remaining Positions on the phenyl radicals unsubstituted or substituted with chlorine, methyl or methoxy. The most preferred HABI is 2,2'-bis (o-chlorophenyl) - 4,4 ', 5,5'-tetraphenylbiimidazole.

Suitable hexaarylbiimidazole photooxidants (B) are disclosed in US Pat. Nos. 3,479,185, 3,549,367, 36 52 275, 37 84 557, 41 62 162, 42 52 887, 42 64 708, 44 59 349 and 46 22 286, whose revelations here through Citations are introduced.

Are leuco dyes useful in this invention apparently in US Pat. No. 3,598,592, the disclosure of which introduced here by quoting. The in this patent, Column 9, lines 4 to 18 described leuco dyes are when in the photosensitive composition present, preferably in the form of the leuco dye stable. Leuco dyes that are less stable than those can be used, so far in the composition of a thermal stabilizer or inhibitor is present.

The leuco form of the dye, which is a component of Inventive photosensitive composition is the reduced form of the dye with a hydrogen atom, whose elimination, in certain In addition to an additional electron, the color  fabric, d. h., provides a different colored compound. Such dyes have been described, for example, in US Pat 34 45 234, column 2, lines 49 to 63 and column 3, Line 39 to column 7, line 55 described, whose Revelation introduced here by quotation. The following Classes fall under:

• (a) aminotriarylmethanes,
• (b) aminoxanthenes,
• (c) aminothioxanthenes,
• (d) amino-9,10-dihydroacridines,
• (e) aminophenoxazines,
• (f) aminophenothiazines,
• (g) aminodihydrophenazines,
• (h) aminodiphenylmethanes.

Preference is given to aminotriarylmethanes. A general preferred class of aminotriarylmethanes is that of Aminotriarylmethanes in which at least two of the Aryl groups phenyl groups are denoted by (a) a R₁R₂N- Substituents in the para position to the bond to the methane Carbon atom, wherein R₁ and R₂ are each groups, selected from hydrogen, C₁-C₁₀-alkyl, 2-hydroxy ethyl, 2-cyanoethyl or benzyl, and (b) a group ortho to the methane carbon atom selected from ni Alkyl (C 1 to 4), lower alkoxy (C 1 to 4), Fluorine, chlorine or bromine; and the third aryl group the same or different from the first two divorce and, if different, from is chosen out

• (1) phenyl which may be substituted with lower Alkyl, lower alkoxy, chloro, dialkylamino, di arylamino, cyano, nitro, hydroxy, fluoro or bromo;
• (2) naphthyl which may be substituted with amino, di (lower alkyl) amino, alkylamino;  
• (3) pyridyl which may be substituted with alkyl;
• (4) quinolyl;
• (5) Indolinylidene which may be substituted with Alkyl.

Preferably, R₁ and R₂ are hydrogen or alkyl 1 to 4 carbon atoms. Especially preferred leuco Dyes of the above class (a) are those described in US Pat 35 98 592, column 9, lines 4 to 18 disclosed Verbin class I compounds, as it stabilizes are. Preferred stabilized leuco dye compounds In the above classes, 9-diethylamino-12- (2-meth oxycarbonylphenyl) benzo [a] xanthene.

Among the useful halogenated compounds (D) gehö halogenated hydrocarbons that are aromatic, aliphatic, alicyclic, heterocyclic and as a combination may be present. Preferably, the halogenated compounds non-ionic. In addition to halogen these compounds can be reacted with oxygen, amine, amide, Hydroxyl, nitrile or phosphate substituted. The Hydrocarbon rings or chains can under be broken by ether (-O-), ester

The halogenated aliphatic compounds gehö Halogenated alkanes and alkenes of 1 to about 8 Carbon atoms, exemplified by alkanes such as carbon tetrachloride, carbon tetrabromide, bromo formo, iodoform, iodoethane, 1,2-diiodoethane, 2-bromo 1-iodoethane, 1,2-dibromoethane, 1-bromo-1-chloroethane, 1,1,2,2-tetrabromoethane, hexachloroethane, 1,1,1-trichloro  ethane, 1,1-bis (p-chlorophenyl) -2,2,2-trichloroethane; sub substituted 1,2-dibromoethane compounds as disclosed in US Pat. No. 4,634,657, column 1, line 56 to column 2, Line 7 and column 2, line 51 to column 3, line 2, whose revelation was introduced here by quotation, including: 1,2-dibromo-1,1,2-trichloroethane, 1,2-dibromo tetrachloroethane, 1,2-dibromo-1,1-dichloroethane, 1,2-di bromo-1,1-dichloro-2,2-difluoroethane, etc .; 1-bromo-3-chloropropane propane, 1,2-dibromo-3-chloropropane, 1,2,3-tribromopropane, 1-bromobutane, 2-bromobutane, 1,4-dibromobutane, 1-bromo- 4-chlorobutane, 1,4-diiodobutane, 1,2,3,4-tetrabromobutane, Pentamethylene bromide, hexamethylene bromide, etc .; on halogenated nierte alkanols with 2 to about 8 carbon atoms such as for example, 2-bromoethanol, 2,2,2-trichloroethanol, tribromoetha nol, 2,3-dibromopropanol, 1,3-dichloro-2-propanol, 1,3-diiodo-2-propanol, 1,1,1-trichloro-2-propanol, bis (iodohexamethylene), aminoisopropanol, 1,1,1-trichloro-2-one methyl-2-propanol, tribromo-t-butanol, 2,2,3-trichlorobutane tan-1,4-diol; halogenated cycloaliphatic compounds such as tetrachlorocyclopropene, dibromocyclopentane, Hexachlorocyclopentadiene, dibromocyclohexane, HET acid anhydride; halogenated aliphatic carbonyl-containing Compounds with 2 to about 8 carbon atoms, at For example, 1,1-dichloroacetone, 1,3-dichloroacetone, hexa chloroacetone, hexabromoacetone, pentachloroacetone, 1,1,3,3-tetrachloroacetone, 1,1,1-trichloroacetone, 3,4-di bromobutanone-2, 1,4-dichlorobutanone-2, 1,2,5-trichlorophene tanon-2, dibromocyclohexanone; halogenated ethers with 3 to about 8 carbon atoms are illustrated by 2-bromoethyl methyl ether, 2-bromoethyl ethyl ether, Bis (2-bromoethyl) ether, bis (2-chloroethyl) ether, 1,2-di chloroethyl ethyl ether etc.

Halogenated amide and ester compounds will be useful moderately in connection with the halogenated  Mono- or dicarboxylic acids with 2 to 8 carbon Ato men, as well as their esters and amides. These Compounds have the general formula:

wherein
X is Cl, Br, or I;
a is an integer of 1 to 4;
A is alkyl or alkenyl of 1 to 7 carbon atoms;
G -OA 'or

is;
wherein A 'is alkyl or haloalkyl having 1 to 15 carbon atoms, wherein halogen is Cl, Br or I;
A "is hydrogen, alkyl or haloalkyl of 1 to 4 carbon atoms, wherein halogen is Cl, Br or I; and
b is 1 or 2.

In connection with the fact that a is an integer from 1 to 4, it should be noted that chemically open visibly impossible structures such as tetrachloro acetamide and β, β, β-trichlorobutyramide excluded are. The proviso that a is an integer from 1 to 4 Accordingly, it should briefly indicate that a is an integer from 1 to 3 when A is a coal has substance atom, and that a is an integer from 1 to 4, when A has 2 to 7 carbon atoms, is present exposed that no carbon atom attached to two other carbon atoms is bound more than two Carries halogen atoms, and no carbon atom, the a carbon atom is bound, more than three halo  carries gene atoms. A may be methyl, ethyl, propyl, butyl, Amyl, hexyl, heptyl, including their isomers, Vinyl, allyl, isopropenyl, butenyl, isobutenyl or Be pentenyl.

The ester may be an ester of a halogenated carbon acid, a halogenated ester of a carboxylic acid or a halogenated ester of a halogenated car bonsäure such as chloroacetic acid, bromoacetic acid acid, iodoacetic acid, dichloroacetic acid, trichloroacetic acid acid, tribromoacetic acid, 2-chloropropionoacetic acid, 3-bromine propionic acid, 2-bromopropionic acid, 2,3-dibromopropion acid, 3-iodopropionic acid, α-bromobutyric acid, α-bromoiso butyric acid, 3,4-dibromobutyric acid, etc .; Brombernstein acid, bromomaleic acid and dibromomaleic acid, etc .; Bromoethyl acetate, ethyl trichloroacetate, trichloroethyltri chloroacetate, isooctyl trichloroacetate, isotridecyltri chloroacetate; Homopolymers and copolymers of 2,3-di bromopropyl acrylate; Trichloroethyl dibromopropionate, iodine ethyl dibromobutyrate, ethyl α, β-dichloroacrylate, ethyl 1,2-dibromovinylacetate etc.

Amides and imides are, for example, chloroacetamide, Bromoacetamide, iodoacetamide, dichloroacetamide, trichloro acetamide, tribromoacetamide, trichloroethyltrichloroacetate amide, 3-bromopropionamide, 2-bromopropionamide, 2,3-dibromo propionamide, 2,2,2-trichloropropionamide, 2-bromobutyr amide, 2-bromoisobutyramide and N-chlorosuccinimide, N-bromo succinimide, 2,3-dibromosuccinimide, N- [1,1-bis (p-chloro phenyl) -2,2,2-trichloroethyl] acetamide, etc. Preferred Amides are those that range from 90 to 150 ° C melt, such as the following compounds:

connection Melting point (° C) BrCH₂CONH₂ 01 ClCH₂CONH₂ 121 Cl₂CHCONH₂ 99.4 ICH₂CONH₂ 95 Br₃CCONH₂ 121.5 Cl₃CCONH₂ 142 BrCH₂CH₂CONH₂ 111 (CH₃) ₂CBrCONH₂ 148 CH₃CH₂CHBrCONH₂ 112.5 (CH₃) ₂CHCHBrCONH₂ 133

To the other halogenated aliphatic carbons Hydrogen compounds include chlorinated rubbers such as the Parlons® (Hercules, Inc., Wilmington, DE), Poly (vinyl chloride), copolymers of vinyl chloride and Vinyl isobutyl ether such. B. Vinoflex® MP-400 (BASF Colors & Chemicals, Inc., Parsippany, NJ), chlorinated aliphatic waxes such as Chlorowax® 70 (Occidental Electrochemicals Corp., Los Angeles, CA), perchlorate cyclodecane, chlorinated paraffins such. Chlorafin® 40 (Hercules, Inc., Wilmington, DE), Unichlor® 70B (Dover Chemical Corp., Dover, OH) and 2,3-bis (bromoethyl) -1,4- dibromo-2-butene.

To the halogenated aromatic hydrocarbon Compounds include polyhalobenzenes such as di-, Tri-, tetra-, penta- and hexachlorobenzene and bromides zol; Di-, tri- and tetrachloro-xylenes and -bromoxylenes; Di- and trichloroaniline and -bromaniline; polyhalogenier te polyphenyl compounds such. For example, the Araclor® soft makers (Monsanto Co., St. Louis, MO), which in general  polychlorinated diphenyls, polychlorinated triphenyls and mixtures thereof, hexabromobiphenyl, tetrabromobis Phenol A etc. are.

To the halogenated heterocyclic compounds ge hear 2,3,4,5-tetraiodopyrrole, 2-tribromomethylquinoline, 2-trichloromethyloxazole etc.

While it is clear that both aliphatic and aroma halides can be successfully used, but the use of aliphatic halides be vorzugt; of the aliphatic halides are used in the general those halides are preferably used which has more than one halogen atom on the same carbon Have atom-bonded, and is particularly preferred the use of those halogenated aliphatic Compounds in which three halogen atoms on a Koh are bound to the fluorine atom. The halogen-containing mate rial can be as a single compound or as a mixture Halogen-containing compounds are present.

Should the compositions be made and for some Time will be stored, then the stability becomes one Factor. For this reason, volatile substances such as about carbon tetrabromide, iodoform, ethyl iodide and 2,2,2-Trichloroethanol, with which normally works well for electrostatic origina which are stored for a substantial period of time, not preferred. These compounds are generally because of their smell and / or their high level of volatility not used. Thus, halogenated compounds preferred, which are non-volatile Liquids or solids.  

There is a wide range of non-polymerizable softeners (E) that are reasonably prone to Exposure times and good printed images ef are fective. Is a macromolecular binder in the photosensitive layer is present, then the selected plasticizers both with the binder as also with the other components of the composition compatible. For example, acrylic binders include to the useful plasticizers: dibutyl phthalate, Di octyl phthalate and other esters of aromatic acids; Esters of aliphatic polyacids, such as diisooctyladi pat and nitrate esters; Ester aromatic or aliphatic shear acids with glycols, polyoxyalkylene glycols, ali phatic polyols; Low molecular weight polyester mass; Allyl and aryl phosphates; as well as chlorinated Paraffins, etc. In general, become water-insoluble Softener for better stability in high air humidity and wider working environment influences are preferred, but are not required. To other useful plasticizers include: triethylene glycol, triethylene glycol diacetate, trietylene glycol dipro Pionat, Triethylenglycoldicaprylat, Triethylenglycoldi methyl ether, bis (2-ethylhexanoic acid) triethylene glycol ester, diheptanoic acid tetraethylene glycol ester, poly (ethy glycol), poly (ethylene glycol) methyl ether, diethylene glycoldibenzoate, glycerol tribenzoate, isopropylnaphtha lin, diisopropylnaphthalene, poly (propylene glycol), tri butyric acid glycerol ester, diethyl adipate, Se bacic acid diethyl ester, dibutyl maleate, Tribu tyl phosphate, tris (2-ethylhexyl) phosphate, t-butylphenyl diphenyl phosphate (Santicizer® 154), triacetin, trimel triacidyl octyl ester, Brÿ® 30 [C₁₂H₂₅ (OCH₂CH₂) ₄OH] and Brÿ® 35 [C₁₂H₂₅ (OCH₂CH₂) ₂₀OH]; Brÿ® is a one trademark of ICI Americas, Wilmington, DE; Tris (2-butoxyethyl) phosphate and phthalates such. B.  Dicyclohexyl phthalate, dioctyl phthalate, diphenyl phthalate lat, diundecyl phthalate, butyl benzyl phthalate (Santi cizer® 160), 2-ethylhexyl benzyl phthalate (Santicizer® 261), alkyl benzyl phthalate (Santicizer® 278). Santi cizer® is a registered trademark of Monsanto Co., St. Louis, MO. Many of the plasticizers can be left specify by the following general formula:

wherein each R₁ and R₂ is an alkyl group of 1 to 10 Carbon atoms is; R₃ is H or an alkyl group with 8 to 16 carbon atoms; R₄ is H or CH₃; x 1 to 4; y is 2 to 10; and z is 1 to 20. Beson preferred plasticizers are dicaprylic acid triethy glycol ester, diheptanoic acid tetraethylene glycol ester, Diethyl adipate, 2-ethylhexyl benzyl phthalate and Tris (2-ethylhexyl) phosphate. Further for the lichtemp sensitive plasticizers will be obvious to professionals and can fiction be used according to. Preferred plasticizers are those that are insensitive to moisture and those who are not like non-polar liquids be extracted about Isopar®-L.

The combination of organic polymeric binder and plasticizer is important for achieving a custom baren contrast potential, that is the voltage lower  divorced between the exposed and unexposed Be rich. Binders with different specific Resistors and Tgs as well as plasticizers with difference union viscosities are chosen so that a certain Degree of radical and / or ion mobility within the film matrix is accessible. A glassy movie matrix would not be suitable since the during the Belich The active species are not generated by the matrix could diffuse to react with each other. Likewise, a film matrix with very low Viskosi would be not able to charge enough high charge in the un withholding exposed areas Tighten toner or developer to get the right one Toner or developer density to achieve.

The acidic additive (F), of which at least one in the light delicate original is present, is selected from the group consisting of:

• (1) Compounds of the general formula R-NH-R'worin is;
  R 1 is H, alkyl having 1 to 12 carbon atoms, aryl having 6 to 30 carbon atoms, substituted alkyl having 1 to 12 carbon atoms, substituted aryl having 6 to 30 carbon atoms, Halogen or a heterocyclic group;
  R and R 'taken together may form a five- to six-membered heterocyclic ring; R¹, R² and R³ may be the same or different and alkyl having 1 to 12 carbon atoms, aryl having 6 to 30 carbon atoms, substituted alkyl having 1 to 12 carbon atoms, substituted aryl having 6 to 30 carbon atoms, Acyl, halogen or a heterocyclic group;
  The group 1 compounds include: sulfonamides and imides, sulfonylureas, carboximides and phosphonamides.
  Sulfonamides and imides are represented by the formula: R¹-SO₂-NH-R'worin R¹ is alkyl of 1 to 12 carbon atoms, aryl of 6 to 30 carbon atoms, substituted alkyl or substituted aryl substituted with alkyl, e.g. Example, with 1 to 10 carbon atoms, alkoxy having 1 to 6 carbon atoms, halogen, z. Cl, Br, I; Amino, carboxylic acid ester, etc.; and
  R 'is H, acyl, alkyl of 1 to 12 carbon atoms, aryl of 6 to 30 carbon atoms, substituted alkyl or substituted aryl substituted as described above for R¹. A sulfonamide is exemplified by A6 in the examples. In addition to o-, p-toluenesulfonamide, α-toluenesulfonamide, p- (p-toluenesulfonamido) -diphenyl amine and benzoic acid sulfonamide, useful sulfonamides and imides for this inven tion are described in the following publications: "Sulfonamides and Allied Compounds" by EH Northey, 1948, Reinhold Publishing Corp., New York; "Sulfonamides", Encyclopedia of Chemical Technology, Vol., 2, Kirk-Othmer, pp. 795-808, 1978, Wiley-Interscience, New York.
  Sulfonylureas are represented by the formula: wherein R¹ and R 'may be the same or different and are alkyl of 1 to 12 carbon atoms, aryl of 6 to 30 carbon atoms, substituted alkyl or substituted aryl substituted with alkyl, e.g. B. with 1 to 10 carbon atoms, alkoxy having 1 to 6 carbon atoms, halogen, z. Cl, Br, I; Amino, carboxylic acid esters etc .; or heterocyclic 5- or 6-membered rings containing N, O, S, Se, P, As etc. in the ring.
  Suitable sulfonylureas and methods of their preparation are described in US Patents 41 27 405, 43 83 113, 43 94 506, 44 20 325, 44 35 206, 44 78 635, 44 79 821, 44 81 029, 45 14 212, 47 89 393 and 48 10 282 as well as in EP-A-87 780; The respective disclosures relating to these compounds are incorporated herein by reference.
  Carboximides are represented by the formula: wherein R¹ and R 'may be the same or different and are alkyl of 1 to 12 carbon atoms, aryl of 6 to 30 carbon atoms, substituted alkyl or substituted aryl substituted with alkyl, e.g. B. with 1 to 10 carbon atoms, alkoxy having 1 to 6 carbon atoms, halogen, z. Cl, Br, I; Amino, carboxylic acid esters etc .; and 5- or 6-membered heterocyclic rings containing N, O, S, Se, P, As, etc. in the ring. R¹ and R 'taken together may form 5- or 6-membered heterocyclic or fused rings. Other carboximide compounds besides phthalimide, diacetamide, parabanic acid (exemplified by A15) include: Phosphonamides are represented by the formula: wherein R¹, R 'and R² may be the same or different and are alkyl of 1 to 12 carbon atoms, aryl of 6 to 30 carbon atoms, substituted alkyl or substituted aryl substituted with alkyl, e.g. B. with 1 to 10 carbon atoms, alkoxy having 1 to 6 carbon atoms, halogen, z. Cl, Br, I; Amino, carboxylic acid esters etc .; Halogen or 5- or 6-membered heterocyclic rings containing N, O, S, Se, P, As etc. in the ring. A phosphonamide is in the examples by A13, phenyl-N-phenylphosphonamidochloridat ver anschaulicht. Other phosphonamide compounds are derived from phosphonic acids, which are described in the following section.
• (2) phosphonic acids of the general formula: wherein R⁴ is alkyl having 1 to 12 carbon atoms, aryl having 6 to 30 carbon atoms, substituted alkyl or aryl, substituted with alkyl, for. Example, with 1 to 10 carbon atoms, alkoxy having 1 to 6 carbon atoms, halogen, z. Cl, Br, I; Amino, carboxylic ester, etc .; and 5- or 6-membered heterocyclic rings containing N, O, S, Se, P, As, etc. in the ring. A phosphonic acid, phenylphosphonic acid, is exemplified by A3 in the examples. Other phosphonic acids are described in the following publications: "Organo Phosphorous Compounds" by GM Kosolapoff, pp. 148-170, 1950, John Wiley and Sons, Inc., New York. "Organophosphorous Chemistry", Specialist Periodical Reports, Vol. 1 to 19, 1970 to 1988, The Chemical Society, Burlington House, London.
• (3) Carboxylic acids which are more acidic than acetic acid are represented by the following formula: wherein R is alkyl or alkylene of 1 to 12 carbon atoms, aryl of 6 to 30 carbon atoms, a 5- or 6-membered heterocyclic ring containing N, O, S, Se, P, As; Alkyl, alkylene, aryl or heterocyclic compounds substituted with alkoxy of 1 to 6 carbon atoms, halogen, e.g. B. F, Cl, Br, I; Amino and alkylamino. In addition, the carboxylic acids may be partially esterified.
  Suitable carboxylic acids include oxalic, maleic, citric, tartaric, benzoic, fumaric, maleic, trichloroacetic, dichloroacetic, perfluorooctanoic, phthalic, diphenic, trimellitic, pyromellitic, naphthalenedicarboxylic acids, etc. Carboxylic acids are illustrated in Examples A1, A2, A7, A8, A9, A10 and A14. Other carboxylic acids are described in the following references: "Practical Organic Chemistry" by AI Vogel, pp. 489-495 and 751-779, 1957, John Wiley & Sons, New York; "Chemistry of Organic Compounds" by CR Noller, p. 173, 594, 870-891, 1965, WB Saunders Company, Philadelphia.
• (4) sulfonic acids of the general formula: wherein R⁵ is alkyl having 1 to 13 carbon atoms, aryl having 6 to 30 carbon atoms, substituted alkyl having 1 to 13 carbon atoms, substituted aryl having 6 to 30 carbon atoms, halogen or a 5- or 6-membered heterocyclic ring containing N, O, S, Se, P, As.
  Useful sulfonic acids are: p-toluenesulfonic acid, naphthalenesulfonic acid, benzenesulfonic acid, 2,5-dimethylbenzenesulfonic acid, 2,4-dinitrobenzenesulfonic acid, o-sulfobenzoic acid, 5-sulfosalicylic acid, 5-dimethylamino-1-naphthalenesulfonic acid, trichlorobenzenesulfonic acid, 5-nitro-o toluenesulfonic acid, 1-butanesulfonic acid, 10-camphorsulfonic acid, 4- (2-hydroxyethyl) -1-piperidine ethanesulfonic acid, 8-hydroxy-5-quinolinesulfonic acid, etc.
  Preferred sulfonic acids are p-toluenesulfonic acid and naphthalenesulfonic acid. Sulfonic acids are illustrated in the examples by A4 and A5.
• (5) inorganic acids selected from the group be from hydrochloric acid, hydrobromic acid, iodine hydrofluoric acid, sulphurous acid, sulfuric acid, nitrous acid, nitric acid, phosphorous  Acid, phosphoric acid, selenious acid, selenic acid and chromic acid. An inorganic acid is in the Examples illustrated by A11.
• (6) Lewis acids are electron deficient molecules or ions capable of free electric coordinate pairs of other molecules. general mine are Lewis acids electrophilic (electron seeking) reagents or electrophiles, the üb Licherweise as catalysts in chemical reaction Electron transfer type and in the cationic polymerization can be used. For the present invention useful Lewis acids are selected from the group consisting of boron fluoride, aluminum chloride, aluminum bromide, zinc chloride, tin (IV) chloride, titanium chloride, etc. Lewis acid is exemplified by A12 in the examples shows. Lewis acids are in the following Citations: E. S. Gould, "Mechanism and Structure in Organic Chemistry ", pp. 115-119, 1959, H. Holt and Company, New York; J. Hine, "Physical Organic Chemistry, "Chapter 2, 1962, McGraw-Hill Book Company, New York.

Among the other useful ingredients used in the photosensitive layer may be present, ge Hear: Co-initiators, sensitizers for visible light, thermal stabilizers or thermoin hibitors, whiteners, absorbents for ultraviolet Light, coating aids, modifiers for the electrical properties, eg. B. electron acceptors, Electron donors etc.

Useful coinitiators include: benzophenones, Alkyl aryl ketones and mixtures thereof.  

Sensitizer for visible light, even if present in the photosensitive layer may, for example, be aryl-glyceryl ketones, as disclosed in US Patent 41 62 162, the disclosure thereof introduced here by quoting. Sensitization Medium absorb radiation in the broad spectral range from 300 to 700 nm. The maximum absorption (λmax) is in the range of 350 to 550 nm.

To the useful thermal stabilizers or thermo Inhibitors include: hydroquinone, 1,4,4-trimethyldi azabicyclo [3.2.2] non-2-ene-2,3-dioxide, 1-phenyl-3-pyra zolidinone, 4-hydroxymethyl-4-methyl-1-phenyl-3-pyrazole lidinone, p-methoxyphenol, alkyl- and aryl-substituted Hydroquinones and quinones, t-butyl catechol, pyro gallol, copper resinate, naphthylamine, β-naphthol, Kup fer (I) chloride, 2,6-di-t-butyl-p-cresol, phenothiazine, Pyridine, nitrobenzene, dinitrobenzene, p-Toluchinon and Chloranil. Also useful are those in the US patent 41 68 982 described dinitroso dimers whose open here by quotation. Preferably is in the photosensitive composition Thermostabilizer or inhibitor present to the Storage stability of the photosensitive composition to increase.

Usable UV absorbents and coating aids are known to professionals.

Useful electron donors and electron acceptors are disclosed in US Patent 48 49 314, and their Offen be introduced here by quotation. To the example len for such compounds include: Aromatic Amines, z. B. triphenylamine, methyldiphenylamine, N, N-di methylaniline; aromatic phosphines, e.g. B. triphenyl  phosphine; triphenylarsine; triphenyl; carbazole Compounds, e.g. For example, 9-ethylcarbazole, poly (9-vinylcarba zol); polycyclic aromatic compounds, e.g. B. Naphthalene, benzophenone, trinitrofluorenone, biphenyl. Triphenylamine is a preferred electron donor, Bi phenyl is a preferred electron acceptor, as in that disclosed US Patent 48 49 314, the open barung, concerning these connections, here by quotation was introduced.

Among the other additives that the electrical properties and the final print quality may include: N-phenylglycine, 1,1-dimethyl-3,5-di ketocyclohexane and organic thiols such. B. 2-Mercap tobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenz imidazole, pentaerythritol tetrakis (mercaptoacetate), 4-acetamidothiophenol, dodecanethiol and β-mercaptoetha nol. Other useful connections include: 1-phenyl-4H-tetrazole-5-thiol, 6-mercaptopurine-mono hydrate, bis (5-mercapto-1,3,4-thiodiazol-2-yl), 2-mer capto-5-nitrobenzimidazole and 2-mercapto-sulfo 6-chlorobenzoxazole etc.

Generally, the essential components of the Photosensitive composition in the following approximate proportions are used: (A) binder, 40 to 85%, preferably 50 to 70%; (B) hexaarylbi imidazole photooxidant, 1 to 20%, preferably 2 to 6%; (C) Leuco Dye, 0.5 to 40%, preferably 0.5 to 6%; (D) halogenated compound, 0.25 to 10%, preferably 0.25 to 5%; (E) plasticizer 2 to 50%, preferably 10 to 40%, and (F) acidic additive 0.1 to 10%, preferably 0.4 to 4%. This is it by weight percent, based on the total weight of the photosensitive composition. The preferred ones Share ratios may vary according to the specific  Set up connection for each component is selected. For example, the amount may vary Component (B) according to the requirements of Filmempfind sensitivity. Compositions, for example, in the content of component (B) exceeds 10% by weight results in films of high sensitivity (high speed) and can digita with laser picture while recording information as with digital color proofing be used. For analog applications, z. B. Exposure by a pull-out copy or Photovor direction, the requirements of Filmemp sensitivity according to the type of exposure.

The photosensitive electrostatic original is prepared by mixing the photosensitive Be constituents in a solvent such as methylene chloride or any other solvent that all components of the photosensitive composition triggers. Useful are also higher boiling additional Liche solvents, the coating and drying support, z. As methanol, isopropanol, etc. The Photosensitive solution can then be using the tray world known aids on a conductive substrate applied and the solvent evaporated. The Dry weight of the coating should be about 40 to 200 mg / dm 2, preferably 80 to 150 mg / dm 2.

The conductive support may be a metal plate such as z. As aluminum, copper, zinc, silver or the like, a conductive polymer film, e.g. For example, polyethylene terephthalate etc., or a carrier such as paper, glass, synthetics Resin etc., by vapor deposition or chemical Deposition on one or both sides with a metal, egg a conductive metal oxide or a conductive metal halide was coated; one with a manager  Polymer coated carrier; or a carrier with a polymeric binder was coated, the Metal, a conductive polymer, carbon or on dere conductive fillers, etc. contains.

Positive images are advantageously produced by single imagewise exposure, followed by up load and toning. The photosensitive layer is be scans with wavelength range 200 to radiation 550 nm, preferably about 310 to 400 nm. Use It can be any convenient source for ultraviolet / visible light, to the lichtemp activate sensitive composition and produce induction of the image. General are light sources, the radiation in the range between about 200 nm and about 550 nm, are needed for image formation bar. The usable light sources include suns lamps, electronic flash units, germicidal lamps, Mercury vapor arc lamps, fluorescent lamps with Ultraviolet-emitting phosphors, argon and Xenon glow lamps, electronic flash units, photo graphic flood lamps, ultraviolet lamps, the specifically provide light of a short wavelength (253.7 nm), and lamps, the light of a long waves length (450 nm). The exposure time varies from a fraction of a second to several Minutes, depending on the intensity of the light, its distance from the photosensitive composition, the opazi the photo device, texture, and quantity the photosensitive composition and the ge wanted color intensity in the image. It can also ko Härente light bundles are used, for example Electron beams, nitrogen pulse lasers, argon Ion lasers and neon II ion lasers whose emissions  in the range of ultraviolet absorption bands of Component (B) fall or overlap with it. Lasers that emit visible light, such as. Argon ion, Krypton-ion, helium-neon and frequency-doubled YAG lasers can be sensitized to the visible photosensitive layers are used.

Ultraviolet-emitting cathode ray tubes used in Printing systems for writing on photosensitive materials are widely used are also useful to the considered compositions with to provide an image. These are in the general to an inner coating of UV-emitting Phosphor as a means of converting electrical Energy in light energy, and a fiber optic Front panel as a means of aligning the radiation on the photosensitive target. For the purpose of this Invention, the phosphors should be below 420 nm emit strong, so that essentially overlap with the absorption characteristic in the near UV of the invention photosensitive compositions entry. Representative examples of phosphors include the types P4B (emitted at 300-550 nm, Maximum at 410 nm), P16 (330-460 nm, maximum at 380 nm) and P22B (390-510 nm, maximum at 450 nm). The Electronic Industries Association, New York, NY P numbers and provides information regarding the Characterization of the phosphors available; Phosphors with the same P number have substantially identical properties.

Images can be generated in the photosensitive layer be through a beam of light or through exposure a selected area behind a positive excerpt copy, a template or another relatively opaque template. The positive excerpt copy  may be one in which the opacity from the aggregation of areas different Refractive index results. Imaging can also be done in a conventional diazo printing apparatus or in a thermographic device, provided that the instrument emits a part of its light in ultraviolet range. A piece of onion skin or machine-described light to medium weight Bank paper, for example, can be used as an original serve, from which copies can be drawn.

If artificial radiation sources are used, then the distance between the photosensitive layer and the radiation source according to radiation sensitivity and nature of the photosensitive composition be varied. Usually Mercury vapor arc lamps used with a gap from 3.8 to 152.4 cm (1.5 to 60 inches) from the photosensitive layer. A radiation flux of 10-10,000 μW / cm² is generally used suitable.

The amount of time over which the photosensitive compositions can be exposed to radiation from Vary in fractions of a second. The exposure times vary in part according to the Nature and concentration of the stabilized Leuco dye, the halogenated compound, of the compatible Plasticizer, photooxidant and the type of radiation. The exposure can be over one wide temperature range, such as from from about 0 ° C to about + 40 ° C for certain compositions. Preferred exposure temperatures are moving in the range of about 10 ° C to about + 35 ° C. It is obvious  of economic advantage if the procedure is carried out at room temperature.

The imagewise exposure, for example during production electrostatic originals, is expediently performed so that a layer of photosensitive Composition through a working slide is exposed to the radiation; that is, one that Image-bearing slide made entirely of areas which is essential for the radiation used impermeable or substantially permeable are, with the impermeable areas substantially have the same optical density; for example a so-called line or halftone negative or -positive. Working slides can be made for any suitable coated material, including cellulose acetate film and polyethylene terephthalate film. By Charging and toning the exposed original arrives you become a positive working original, that for the Application in color proofing, etc. suitable is.

The preferred means of charging is corona discharge. You can also use other charging methods, z. B. discharge of a capacitor, a shielded corotrons, scorotrons etc.

It can be any electrostatic liquid toner or a dry powder toner and any method of Toner application can be used. Preferred liquid toners consist essentially of a suspension Pigmented resin toner particles in a non-polar Liquid, wherein the toner particles by ionic or zwitterionic compounds are charged. The normally used non-polar liquids  the branched aliphatic Isopar® hydrocarbons (registered trademark of Exxon Corporation), which have a Kauri butanol value of less than 30. It these are narrow cut isoparaffinic hydrocarbon fractions high purity with the following boiling ranges: Isopar®-G 157-176 ° C, Isopar®-H 176-191 ° C, Isopar®-K 177-197 ° C, Isopar®-L 188-206 ° C, Isopar®-M 207-254 ° C, Isopar®-V 254-329 ° C. Preferred resins with an average particle size of less than 10 microns, preferably less than 5 microns are copolymers of ethylene (80 to 99.9%) / acrylic or methacrylic acid (20 to 0%) / alkyl esters of acrylic or methacrylic acid, the alkyl having 1 to 5 carbon atoms (0 to 20%), z. B. Copolymers of ethylene (89%) and methacrylic acid (11%) with a melt index of 100 at 190 ° C. preferred in non-polar liquids soluble ionic or zwitterionic charge-directing compounds are lecithin and oil-soluble basic barium Petronate® petroleum sulfonate, Witco Corp., New York, NY. In the non-polar liquid is optionally at least an auxiliary connection exists as described in US Patents 46 31 244, 46 63 264, 47 34 352, 46 70 370, 47 02 985, 46 81 831, 47 02 984 and 47 07 429. The disclosures of these US patents are introduced here by quote.

To the typical representatives for suitable dry ones electrostatic toners include: Kodak Ektaprint® K, Hitachi HI-HMT-414 toner, Canon NP-350F toner, Toshiba T-50P toner, etc. The invention is characterized by these toners not limited.

After toning or developing, the toned or developed image for the production of a proof transferred to a receiver surface such as paper, etc.  You can do it from the latter to another Transmit receiver to a correct reading image to get. Other receivers are, but not limited to to be, polymer films or cloth. For the production of boards of integrated circuits can the transfer surface is an insulating board be covered with a ladder, z. Legs Fiberglass board covered with a copper layer is what, with the help of this method is a resist is printed. The transfer becomes electrostatic or otherwise accomplished, e.g. B. by contact with a sticky receiver surface. The Electrostatic transfer can be to any known Kind of happen, z. B. by the transfer surface brought into contact with the toned image, put a conductive rubber roller on the surface is to ensure maximum contact, and immediately afterwards a corona discharge on the back the transmission element comes into action.

Industrial applicability

The photosensitive electrostatic original with improved retransmission characteristic is particular useful in the field of graphic arts, especially in the field of color proofing, Duplicates with prints made by printing be generated. Because of the molecular structure of Color images is very high resolution possible. On photosensitive electrostatic original with printed Image (POI) has additional advantages, including:

• (1) the user can immediately see that the Original was exposed;  
• (2) Multiple etches or images can be made and be easily positioned;
• (3) Visual corrections can be made easier; This is very important in the removal of Cut lines of positive photosensitive originals;
• (4) unexposed areas can with a light pen be marked, and the marking will then be part of the information on the Original; and
• (5) the ability to use POIs in different colors make it possible to use originals with one To provide color coding, z. B. can the original a cyan blue draw copy of a cyan blue POI have the original of the magenta excerpt copy there a magenta POI, etc .; This can be mistakes due to mispositioning of the original avoid with a sequential printing system.

The photosensitive electrostatic original can also be used to a resistant to etching Paint for the production of printed circuit boards transferred to.

Examples

The following examples illustrate the invention, However, do not restrict it. Shares and percentages are weight related.

directory binder

B1 poly (styrene / methyl methacrylate) copolymer 70/30; Tg = 95 ° C (Tg: glass transition temperature)
B2 poly (ethyl methacrylate), n = 1.5 (n: logarithmic viscosity number); Tg = 70 ° C
B3 poly (methyl methacrylate), n = 0.18; Tg = 105 ° C
B4 poly (methyl methacrylate), n = 1.25; Tg = 110 ° C

softener

P1 2-ethylhexyl benzyl phthalate

Initiators / photochemical oxidants

IN1 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole
IN2 2,2 ', 4,4'-tetrakis (o-chlorophenyl) -5,5'-bis (m, p-dimethoxyphenyl) biim-idazole

leuco

LD1 tris (4-thylamino-o-tolyl) methane

Halogen compound

H1 1,2-dibromotetrachloroethane

Acid additives

A1 phthalic acid
A2 oxalic acid
A3 phenylphosphonic acid
A4 p-toluenesulfonic acid
A5 naphthalenesulfonic acid
A6 p-toluenesulfonamide
A7 diphenic acid
A8 benzoic acid
A9 2-chlorobenzoic acid
A10 perfluorooctanoic acid
A11 phosphoric acid
A12 zinc chloride
A13 phenyl-N-phenylphosphonamidochloridate
A14 citric acid
A15 parabanic acid

Various

M1 1-phenyl-3-pyrazolidinone (phenidone)
M2,4,4'-bis (diethylamino) benzophenone
M3 2-mercaptobenzoxazole
M4 Pluronic® 31R, ethylene oxide / propylene oxide block copolymer surfactant, available from BASF Corp., Parsippany, NJ

Unless otherwise noted, the following procedures were used applied to all examples.

An aluminized polyethylene terephthalate carrier with 0.0102 cm (0.004 inch) was coated with a solution, the about 80 parts of methylene chloride and 20 Parts contained solids. After the film for removal of the methylene chloride at 60-85 ° C dried was, was a polypropylene topcoat with 0.0019 cm (0.00075 inch) on the dried layer laminated. The coating weight varies from 80 up to 150 mg / dm². Until the exposure and development The film was wound on rolls.

To the picture quality of each photosensitive Composition was to be photosensitive Layer exposed, charged and with magenta toner Toned, and the image was as described below Transferred paper. In all cases, "magenta toner" means  the standard magenta toner used to generate a four-color print described below wur wur de. The evaluation of the image quality happened based on dot area and dot gain the paper. The standard paper is 60 lbs Solitaire® Paper, Offset Glossy Printing, Plainwell Paper Co., Plainwell, MI. Among the various tested Pa however, were: 60 lbs Plainwell Offset high gloss pressure, 70 lbs Plainwell Offset Glossy Printing, 150 lbs White Regular Tufwite® Wet Strength Day, 60 lbs white LOE gloss cover, 70 lbs white Flokote® text, 60 lb white general purpose litho paper, 110 lb white Scott Index, 70 lbs White Nekoosa Vellum Offset and 80 lbs white Sov® text. The results showed that, though the procedure can be done with any paper can, retaining the color depending on the fiber The amount of paper used varies.

Dot gain or dot growth versus dot size is a standard method for determining the deviation between a deduction and a revision deduction. The Dot reinforcements were measured using help designs ner templates, so-called Brunner targets, available at System Brunner USA, Inc., Rye, NY. typically, are those for the application in graphic art he Wanted point gains in the range of 15 to 22% at midtone. The dot gain became easier Way measured using UGRA Targets, Graphic Arts Technical Foundation, Pittsburgh, PA, which tops 0.5% points of light at 99.5% shadow points on a screen with 381 lines / cm (150 lines / inch) containing 4 up to 70 μm top light and shadow microlines ent held. Typically, these are included in the application graphic art desired dot areas in the area from 2 to 98%.  

The photosensitive electrostatic original was first exposed by a positive excerpt copy with a Douthitt Option X Exposure Unit (Douthitt Corp., Detroit, MI), equipped with a lamp assembly Violux® 5002. Model TU 64 (Exposure Systems Corp., Bridgeport, CT) and a photopolymer-type lamp, Model No. 5027. Exposure times varied after preparation of 1-100 s. The exposed original was then mounted on a drum surface. The SWOP density (Specification Web Offset Publications) in the solid areas were obtained by charging the unexposed areas of the photosensitive Layer of electrostatic original to 100 to 500 V. The charged latent image was then with an electrostatic liquid developer or toner developed using a two-roll toner station and the developer layer was measured exactly. Development and measuring station were at the Six o'clock position of the drum arranged. The toner Image was placed on paper by corona, with 10-150 μA transfer corona and 4.35 to 4.88 kV, as well -2.5 to -8.0 kV Adhesive tension at Ge speed of 5,59 cm / s (2.2 in / s) and in one Oven fused for 15 s at 100 ° C.

A four-color print will be made as described below Received steps. First, before the exposure complementary registration marks in the lichtempfindli layers of the electrostatic original cut. For each of the four color separation copies are Originals made by exposing four light sensitive elements with cover sheets to one of four negative color separation copies of the colors cyan blue, yellow, magenta and black. One each the four photosensitive layers is by means of  the exposure unit Douthitt described above Option X exposed. The emitted by this source visible radiation is transmitted by means of a UV light casual, visible light absorbing Kokomo® glass No. 400, Kokomo Opalescent Glass Co., Kokomo, IN) is suppressed. The cover sheets are removed, and Each original will be on the appropriate color Module drum mounted in a position with which the Image registration of the four images ensured is when they are successively from each original to the Transferred recipient paper. There will be pressure Clamps used to return the aluminized level side of the photosensitive original with the drum conductively connect. The originals are made by spring Strain of the trailing edge stretched, which sicherge is that each lies flat against its drum.

Each module includes a charging scorotron in three o'clock Position, a development station in five o'clock posi tion, a measuring station in six o'clock position and one Cleaning station in nine o'clock position. The process of Charging, developing and measuring are similar to that described above before the examples. The transfer gungsstation consists of an adhesive roller, a Transfer corona, a paper loader and a Positio which shows the relative position of Pa pier and original for all four transfer operations fixed.

When making the four-color print, the four have Developer or toner the following compositions:

black ingredients Quantity (g) Copolymer of ethylene (89%) and methacrylic acid (11%), melt index 100 at 190 ° C; Acid number 66 2 193.4 Sterling NF soot 527.44 Heucophthal Blue, G XBT-583D Heubach, Inc., Newark. NJ 27.76 Barium Petronate® Witco Corp. Base, New York, NY 97.16 Aluminum tristearate Witco 132 Witco Corp., New York, NY 27.76 Isopar®-L, non-polar liquid with a Kauri-butanol value of 27; Exxon Corp. 188 670.0

cyan ingredients Quantity (g) Copolymer of ethylene (89%) and methacrylic acid (11%), melt index 100 at 190 ° C; Acid number 66 3 444.5 Ciba Geigy Monarch Blue X3627 616.75 Dalamar® Yellow YT-858D Heubach, Inc., Newark. NJ 6.225 Aluminum tristearate as described in black developer 83.0 Basic Barium Petronate® (Witco Corp.) 311.25 Isopar®-L as described in black developer 292 987.0

magenta ingredients Quantity (g) Copolymer of ethylene (89%) and methacrylic acid (11%), melt index 100 at 190 ° C; Acid number 66 3,973.47 Mobay RV-6700, Mobay Chemical Corp., Haledon, NJ 1 156.66 Mobay RV-6713, Mobay Chemical Corp., Haledon, NJ 204.12 Aluminum tristearate S Witco Corp. 108.86 Basic Barium Petronate® (Witco Corp.) 326.58 Isopar®-L as described in black developer 378 876.0

yellow ingredients Quantity (g) Copolymer of ethylene (89%) and methacrylic acid (11%), melt index 100 at 190 ° C; Acid number 66 1 824.75 Yellow 14, polyethylene flush Sun Chemical Co., Cincinnati, OH 508.32 Aluminum tristearate as described in black developer 46.88 Basic Barium Petronate® (Witco Corp.) 58.5 Isopar®-L as described in black developer 160 191.0

First the cyan original is charged, ent wraps and surveys. The transfer station will be in Positioned and toned cyan image transfer the paper. After the cyan blue transfer is completed, the magenta original Koro na-loaded, developed and measured, and the magenta red image is applied to the cyan according to the registration mark transmit blue image. After that, the yellow original Corona-charged, developed and measured, and the yellow Image is on the two previous images transfer. Finally, the black original Corona-charged, developed and measured, and the ge Toned black image is recorded according to the registration mark transmit the three previously transmitted images. by  the procedure is completed, the paper becomes carefully removed from the transfer station and the Image fused for 15 s at about 100 ° C.

The parameters in the preparation of the proof are: Drum speed 5,588 cm / s (2.2 inches / s); Grating scorotron voltage 100 to 400 V; scorotron Current 200 to 1000 μA (5.11 to 6.04 kV); measuring rollers voltage 20 to 200 V; Adhesive tension -0.5 to -8.0 kV; Transfer coronary current 1 to 150 μA (4.35 to 4.88 kV); Measuring roller speed 10.16 to 20.32 cm / s (4 to 8 inches / second); Measuring nip 0.0051 to 0.0127 cm (0.002 to 0.005 inches); Conductivity of the developer 12 to 30 pS / cm (12 to 30 picomhos / cm); developer Concentration 1 to 2.0% solids.

To check the retransfer, the exposed Element attached to a drum surface. The ge charge latent image was ent ent with the magenta toner wound, which ver for the production of four-color deduction ver had been used. Corona voltage and current for charging were adjusted so that SWOP density in the hard substance areas. The standard conditions were 200 up to 300 V in the Scorotron grid and 550 μm corona charging electricity.

After the transfer of the first image was finished, the photosensitive element (electrostatic Original) in three consecutive charging, developing Transmission and transmission cycles as follows on the return degree of transmission tested: The paper, with a wet Image on top, was carefully in the transfer posi tion. The beginning edge of the photosensitive Elements and the wet image were on the paper 2.54 cm (1 inch) apart,  where beginning and trailing edge of the paper from the light sensitive element were kept away. The electro static original was cleaned and the second Charging, development and transmission cycle started. So a second layer of toner was on top of the ur received a perfect image. The efficiency of the second Image transfer as well as the extent of retransmission of the previous image were taken from a control panel person who is near the exit of the Transmission zone was. After finishing the second Transfer, this process became a third and four repeated time, with the retransmission constantly was checked. These four passes simulate the Real production of a four-color print in which the first developed image three more times over field is suspended before the withdrawal is completed. The above process has been over for at least two years conditions, wherein the corona current to Transfer from 10 to 50 μA and the adhesive roll chip from -0.5 to -8.0 kV (standard conditions: 30 μA and -3.5 kV). The presence of acid additives in the photosensitive layer, as in the following Examples clearly illustrated, the diminished Retransmission under a wide range of labor conditions. A photosensitive layer under These conditions should not be retransmitted should as electrostatic original in a multi-color system be suitable.

Examples 1-5

There were solutions of the photosensitive composition made of 80 parts of methylene chloride and 20 parts of solids contained. The solids included Binders or combinations of binders, soft  activator, initiator, halogen compound, leuco dye and acidic additive. The solutions were aluminized conductive polyethylene terephthalate supports of 0.0102 cm (0.004 inch) coated with a polypropylene 0.001905 cm (0.00075 inch) overlay laminated were. The coating weights varied from 80 to 150 mg / dm² or approximate thickness of 7 to 12 μm.

The photosensitive layers for each element has the compositions shown in Table 1, wherein the quantities are given in parts by weight. The light sensitive elements were created with the help of magenta Toners and the procedure described above Retransfer checked. The results are in after Table 2 summarized.

Table 1

Table 2

retransfer

This table illustrates the use of acid ad additives for reducing the re-transfer.

Examples 6 to 12

Eight photosensitive elements were prepared and evaluated as described in Example 1, with the following Exceptions: The photosensitive layer for each Ele ment had Zu shown in Table 3 below composition. The results for the retransfer are summarized in Table 4 below.  

Table 3

Table 4

retransfer

This table illustrates the benefits of acid Addi tive to control 2.  

Examples 13 to 17

Six photosensitive elements were prepared and evaluated as described in Example 1, with the following Exceptions: The photosensitive layer for each Ele ment had the Zu shown in Table 5 below Composition, wherein the black toner in this Be evaluation was used. The results are in after Table 6 summarized.

Table 5

Table 6

retransfer

Examples 18 to 23

Six photosensitive elements were prepared and evaluated as described in Example 1, with the following Exceptions: The photosensitive layer for each element had the composition shown in Table 7 below, the black toner in this review was used. The results are shown below Table 8 summarized.

Table 7

Table 8

Return transfer 03917 00070 552 001000280000000200012000285910380600040 0002004134987 00004 03798ung

This table shows clearly that inorganic Acid (Ex 20) and Lewis acid (Ex 21 and 22) for Reduction of retransfer also useful Additives are like the organic acid substances.

Examples 24 to 26

Four photosensitive elements were prepared and evaluated as described in Example 1, with the following Exceptions: The photosensitive layer for each element had the composition shown in Table 9 below, the black toner in this review was used. The results are shown below Table 10 summarized.

Table 9

Table 6

retransfer

example 27

This example demonstrates how to use the photosensitive electrostatic original at the Production of a four-color print.

The following composition was prepared from specified components in parts by weight:

After the solution was stirred for 24 h, all Correctly solving components has become a reality an aluminized polyethylene terephthalate film base 0.0102 cm (0.004 inch) at a coating speed of 30.48 m / min (100 ft / min). The coating weight was 120 mg / dm 2. immediate after drying, a polypropylene topcoat was made 0.001905 cm (0.00075 inch) across the photosensitive Laminated layer. The material thus formed was used for making a four color proof in four pieces of about 76.2 cm by 101.6 cm (30 inches times 40 inch) size cut.

A four-color print was obtained according to the above indicated general method of preparation a color proof, using photosensitive electrostatic originals by the respective cyan, magenta, yellow and black positive color abstract copies were exposed through. point range and midtone (50%) - Dot gain of a typical Pressure are summarized below.

Claims (69)

Anspruch [en] A high resolution photosensitive electrostatic original forming imagewise exposed image areas upon imagewise exposure, the original comprising an electrically conductive substrate carrying a photosensitive composition layer consisting essentially of:

• (A) at least one organic polymeric binder,
• (B) a hexaarylbiimidazole photooxidant,
• (C) a leuco dye which can be oxidized by the photo oxidant to an ionic species,
• (D) a nonionic halogenated compound,
• (E) at least one compatible plasticizer, and
• (F) at least one acidic additive selected from the group consisting of:
  • (1) Compounds of the general formula R-NH-R'worin is;
    R 'H, alkyl having 1 to 12 carbon atoms, aryl having 6 to 30 carbon atoms, substituted alkyl having 1 to 12 carbon atoms, substituted aryl having 6 to 30 carbon atoms, Halogen or a heterocyclic group;
    R and R 'taken together may form a five- to six-membered heterocyclic ring; R¹, R² and R³ may be the same or different and alkyl having 1 to 12 carbon atoms, aryl having 6 to 30 carbon atoms, substituted alkyl having 1 to 12 carbon atoms, substituted aryl having 6 to 30 carbon atoms, Acyl, halogen or a heterocyclic group;
  • (2) phosphonic acids of the general formula: wherein R⁴ is alkyl of 1 to 12 carbon atoms, aryl of 6 to 30 carbon atoms, substituted alkyl of 1 to 12 carbon atoms, substituted aryl of 6 to 30 carbon atoms, halogen or a heterocyclic group;
  • (3) carboxylic acids which are more acidic than acetic acid;
  • (4) sulfonic acids of the general formula: wherein R⁵ is alkyl of 1 to 12 carbon atoms, aryl of 6 to 30 carbon atoms, substituted alkyl of 1 to 12 carbon atoms, substituted aryl of 6 to 30 carbon atoms, halogen or a heterocyclic group;
  • (5) inorganic acids, and
  • (6) Lewis acids.

2. Photosensitive electrostatic original according to claim 1, wherein the acidic additive (1) is the formula R¹-SO₂-NH-R ', wherein R¹ is alkyl having 1 to 12 carbon atoms, Aryl having 6 to 30 carbon atoms, substituted alkyl or substituted aryl; and R 'H, acyl, alkyl of 1 to 12 carbon atoms, aryl with 6 to 30 carbon atoms, substituted alkyl and substituted aryl. 3. Photosensitive electrostatic original according to claim 2, wherein the acid represented by the formula Additive is a sulfonamide. 4. Photosensitive electrostatic original according to claim 3, wherein the acidic additive is a mixture of o- and p-toluenesulfonamide.   5. Photosensitive electrostatic original according to claim 3, wherein the acidic additive α-toluenesulfonamide is. 6. Photosensitive electrostatic original according to claim 3, wherein the acidic additive p- (p-toluenesulfonamido) -diphenylamine is. 7. Photosensitive electrostatic original according to claim 2, wherein the acid represented by the formula Additive is a sulfonimide. 8. Photosensitive electrostatic original according to claim 7, wherein the acidic additive Benzoesäuresulfonimid is. The photosensitive electrostatic original according to claim 1, wherein the acidic additive is a sulfonylurea represented by the formula wherein R¹ and R 'may be the same or different and are alkyl having 1 to 12 carbon atoms, aryl having 6 to 30 carbon atoms, substituted alkyl or substituted aryl substituted with alkyl, alkoxy, halogen, amino, carboxylic ester, etc .; or five- or six-membered heterocyclic rings. The photosensitive electrostatic original according to claim 1, wherein the acidic additive (1) has the formula wherein R¹ and R 'may be the same or different and are alkyl of 1 to 12 carbon atoms, aryl of 6 to 30 carbon atoms, substituted alkyl, substituted aryl, five- or six-membered heterocyclic rings, and R¹ and R' taken together may form five- or six-membered heterocyclic or condensed rings. 11. A photosensitive electrostatic original according to claim 10, wherein the acidic additive is a phthalimide. 12. Photosensitive electrostatic original according to claim 10, wherein the acidic additive is diacetamide. 13. Photosensitive electrostatic original according to claim 10, wherein the acidic additive is a five- or six-membered heterocyclic or condensed Ring is. 14. Photosensitive electrostatic original according to claim 13, wherein the acidic additive is parabanic acid. The photosensitive electrostatic original according to claim 1, wherein the acidic additive (1) has the formula wherein R¹, R 'and R² may be the same or different and are alkyl of 1 to 12 carbon atoms, aryl of 6 to 30 carbon atoms, substituted alkyl, substituted aryl, halogen or five- or six-membered heterocyclic rings. 16. Photosensitive electrostatic original according to claim 15, wherein the acidic additive phenyl-N-phenylphosphonamidochloridat is. The photosensitive electrostatic original according to claim 1, wherein the acidic additive (2) has the formula wherein R⁴ is alkyl of 1 to 12 carbon atoms, aryl of 6 to 30 carbon atoms, substituted alkyl, substituted aryl, halogen, or a five- or six-membered heterocyclic ring. 18. Photosensitive electrostatic original according to claim 17, wherein the acidic additive is phenylphosphonic acid is. The photosensitive electrostatic original according to claim 1, wherein the acidic additive (3) has the formula where R is alkyl or alkylene of 1 to 12 carbon atoms, aryl of 6 to 30 carbon atoms, is a five- or six-membered heterocyclic ring containing N, O, S, Se, P, As, and partial esters thereof Acids, substituted alkyl, alkylene, aryl or heterocyclic compounds. 20. Photosensitive electrostatic original according to claim 19, wherein the acidic additive is phthalic acid. 21. A photosensitive electrostatic original according to claim 19, wherein the acidic additive is maleic acid. 22. Photosensitive electrostatic original according to claim 19, wherein the acidic additive is diphenic acid. 23. A photosensitive electrostatic original according to claim 1, wherein the acidic additive (4) has the formula in which R⁵ is alkyl having 1 to 12 carbon atoms, aryl having 6 to 30 carbon atoms, substituted alkyl having 1 to 12 carbon atoms, substituted aryl having 6 to 30 carbon atoms, halogen or a five- or six-membered heterocyclic Ring containing N, O, S, Se, P, As. 24. Photosensitive electrostatic original according to claim 23, wherein the acidic additive p-toluenesulfonic acid is. 25. Photosensitive electrostatic original according to claim 23, wherein the acidic additive naphthalenesulfonic acid is.   26. Photosensitive electrostatic original according to claim 1, wherein the acidic additive (5) is selected from the group consisting of hydrochloric acid, hydrobromic acid, Hydriodic acid, sulphurous acid, Sulfuric acid, nitrous acid, nitric acid, phosphorous Acid, phosphoric acid, selenious acid, selenic acid and chromic acid. 27. Photosensitive electrostatic original according to claim 26, wherein the acidic additive is phosphoric acid. 28. Photosensitive electrostatic original according to claim 1, wherein the acidic additive (6) is selected from the group consisting of boron fluoride, aluminum chloride, Aluminum bromide, zinc chloride, tin (IV) chloride and titanium chloride. 29. Photosensitive electrostatic original according to claim 28, wherein the acidic additive is zinc chloride. 30. Photosensitive electrostatic original according to claim 1, wherein the photooxidant a 2,2 ', 4,4', 5,5'-hexaarylbiimdazole. 31. Photosensitive electrostatic original according to claim 30, wherein the photooxidant 2,2 ', 4,4'-tetrakis (o-chlorophenyl) -5,5'-bis (m, p-dimethoxyphenyl-biimidazole is. 32. Photosensitive electrostatic original according to claim 30, wherein the photooxidant 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole is. 33. Photosensitive electrostatic original according to claim 1, wherein the polymeric binder is poly (methyl methacrylate) is.   34. Photosensitive electrostatic original according to claim 1, wherein the polymeric binder poly (styrene / methyl methacrylate) copolymer is. 35. Photosensitive electrostatic original according to claim 1, wherein the polymeric binder polystyrene is. 36. Photosensitive electrostatic original according to claim 1, wherein the leuco dye is stabilized. 37. Photosensitivity Electrostatic original according to claim 36, wherein the stabilized leuco dye Tris is (4-diethylamino-o-tolyl) methane. 38. Photosensitive electrostatic original according to claim 36, wherein the stabilized leuco dye is 9-diethylamino-12- (2-methoxycarbonylphenyl) -benzo [a] xanthene is. 39. Photosensitive electrostatic original according to claim 1, wherein the halogenated compound is a halogenated Hydrocarbon is selected from Group consisting of aromatic, aliphatic, alicyclic and their combinations. 40. Photosensitive electrostatic original according to claim 39, wherein the halogenated hydrocarbon is substituted by a representative selected from the group consisting of oxygen, amine, amide, hydroxyl, Nitrile and phosphate. 41. Photosensitive electrostatic original according to claim 39, wherein the halogenated hydrocarbon 1,2-dibromotetrachloroethane.   42. Photosensitive electrostatic original according to claim 39, wherein the halogenated hydrocarbon Trichloroacetamide is. 43. Photosensitive electrostatic original according to claim 1, wherein the plasticizer is selected from the Group consisting of dioctyl phthalate, triacetin, t-butylphenyl diphenyl phosphate, Diethylene glycol dibenzoate and 2-Ethylhexylbenzylphthalat. 44. Photosensitive electrostatic original according to claim 43, wherein the plasticizer 2-ethylhexylbenzyl phthalate is. 45. Photosensitive electrostatic original according to claim 1, wherein the conductive substrate aluminized Polyethylene terephthalate is. 46. Photosensitive electrostatic original according to claim 1 wherein the binders (A) are present at 40 to 85% are the photooxidant (B) with 1 to 20% is present, the leuco dye (C) with 0.5 to 40% is present, the halogenated compound (D) with 0.25 to 10%, the plasticizer (E) with 2 to 50% is present, and the acidic additive (F) with 0.1 to 10% is present, these weight percentages on the total weight of the photosensitive composition are related. 47. Photosensitive electrostatic original according to claim 1, wherein a visible sensitizer Light is present. 48. Photosensitive electrostatic original according to claim 47, wherein the sensitizer for visible Light is an arylylidenarylketone.   49. Photosensitive electrostatic original according to claim 1, wherein a thermal stabilizer is present. 50. Photosensitive electrostatic original according to claim 49, wherein the thermal stabilizer 1-phenyl-3-pyrazolidinone is. 51. The photosensitive electrostatic original according to claim 1, wherein the photosensitive composition layer consists essentially of

• (A) poly (methyl methacrylate),
• (B) 2,2'-bis (o-chlorophenyl) -4,4'5,5'-tetraphenylbiimidazole,
• (C) tris (4-diethylamino-o-tolyl) methane,
• (D) 1,2-dibromotetrachloroethane,
• (E) 2-ethylhexyl benzyl phthalate, and
• (F) p-toluenesulfonic acid.

52. Photosensitive electrostatic original according to claim 1, being above the photosensitive Layer a protective topcoat is located. 53. Xero printing process for producing positive images with a single imagewise exposure, comprising

• (a) imagewise exposing a photosensitive electrostatic original to actinic radiation, the original comprising an electrically conductive substrate bearing a photosensitive composition layer consisting essentially of:
  • (A) at least one organic polymeric binder,
  • (B) a hexaarylbiimidazole photooxidant,
  • (C) a leuco dye which can be oxidized by the photo oxidant to an ionic species,
  • (D) a nonionic halogenated compound,
  • (E) at least one compatible plasticizer, and
  • (F) an acidic additive selected from the group consisting of:
    • (1) Compounds of the general formula R-NH-R'worin is;
      R 'H, alkyl having 1 to 12 carbon atoms, aryl having 6 to 30 carbon atoms, substituted alkyl having 1 to 12 carbon atoms, substituted aryl having 6 to 30 carbon atoms, Halogen or a heterocyclic group;
      R and R 'taken together may form a five- to six-membered heterocyclic ring; R¹, R² and R³ may be the same or different and alkyl of 1 to 12 carbon atoms, aryl of 6 to 30 carbon atoms, substituted alkyl of 1 to 12 carbon atoms, substituted aryl of 6 to 30 carbon atoms, acyl Are halogen, or a heterocyclic group;
    • (2) phosphonic acids of the general formula: wherein R⁴ is alkyl of 1 to 12 carbon atoms, aryl of 6 to 30 carbon atoms, substituted alkyl of 1 to 12 carbon atoms, substituted aryl of 6 to 30 carbon atoms, halogen or a heterocyclic group;
    • (3) carboxylic acids which are more acidic than acetic acid;
    • (4) sulfonic acids of the general formula: wherein R⁵ is alkyl of 1 to 12 carbon atoms, aryl of 6 to 30 carbon atoms, substituted alkyl of 1 to 12 carbon atoms, substituted aryl of 6 to 30 carbon atoms, halogen or a heterocyclic group;
    • (5) inorganic acids, and
    • (6) Lewis acids.
• (b) electrostatically charging the original to form a latent image of electrostatic charges in the unexposed areas;
• (c) developing the latent image by applying an oppositely charged electrostatic toner or developer, and
• (d) transferring the toned or developed image to a receiver surface.

54. The method of claim 53, wherein the actinic radiation in the spectral range from 200 to 500 nm. 55. The method of claim 53, wherein the source of actinic Radiation is ultraviolet / visible light. 56. The method of claim 53, wherein the source of actinic Radiation is a cathode ray tube, the emitted ultraviolet light. 57. The method of claim 53, wherein the source of actinic Radiation is a laser, the ultraviolet or emitting visible light. 58. The method of claim 53, wherein the source of actinic Radiation is an electron beam. 59. The method of claim 53, wherein the original by a corona discharge is electrostatically charged. 60. The method of claim 53, wherein the image by means of an electrostatic liquid developer developed becomes.   61. The method of claim 60, wherein the electrostatic Liquid developer essentially consists of a Carrier liquid with a Kauri butanol value of less than 30, which exist in overwhelming numbers is, particles of a thermoplastic resin with a average particle size of less than 10 μm, and an ionic liquid soluble in the carrier liquid or zwitterionic charge-directing compound. 62. The method of claim 53, wherein the image by means of developed a dry electrostatic toner becomes. 63. The method of claim 53, wherein the toned image is transferred to a paper receiver. 64. The method of claim 53, wherein the toned image on an insulating board with a conductive surface is transmitted. 65. The method of claim 53, wherein the layer of photosensitive composition consists essentially of

• (A) poly (methyl methacrylate),
• (B) 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'-tetraphenylbiimidazole,
• (C) tris (4-diethylamino-o-tolyl) methane,
• (D) 1,2-dibromotetrachloroethane,
• (E) 2-ethylhexyl benzyl phthalate, and
• (F) p-toluenesulfonic acid.

66. The method of claim 53, wherein the electrostatic Liquid developer essentially consists of a Carrier liquid with a Kauri butanol value of  less than 30, which exist in overwhelming numbers is, particles of a thermoplastic resin with a average particle size of less than 10 μm, and an ionic liquid soluble in the carrier liquid or zwitterionic charge-directing compound. 67. The method of claim 65, wherein the electrostatic Liquid developer essentially consists of a Carrier liquid with a Kauri butanol value of less than 30, which exist in overwhelming numbers is, particles of a thermoplastic resin with a average particle size of less than 10 μm, and an ionic liquid soluble in the carrier liquid or zwitterionic charge-directing compound. 68. The method of claim 53, wherein the image by means of developed a dry electrostatic toner becomes. 69. The method of claim 53, wherein the photosensitive Layer is a protective overcoat, which removed before the imagewise exposure becomes.