US3660084A - Recording process using quinolin-2-one or quinolin-4-one organic photoconductive substances - Google Patents

Abstract

Electrophotographic recording process wherein a pattern of increased conductivity is produced image-wise in a photoconductive insulating recording layer using as the essential photoconductive compound guinolin-2-one, quinolin-4-one, certain analogs and structural derivatives thereof, as well as the bis forms thereof, dispersed in an insulating binder. At least about 10 percent by weight of the recording element is constituted by the photoconductive compound and a spectral sensitizing agent for the photoconductor can be included. This class of photoconductors is also useful in the production of phosphor patterns on cathoderay tube screens.

Description

O United States Patent [151 3,660,084

Vanheertum et al. May 2, 1972 [54] RECORDING PROCESS USING References Cited QUINOLIN-Z-ONE 0R QUINOLIN-4-ONE UNITED STATES PATENTS ORGANIC PHOTOCONDUCTIVE Rlttel' 3,316,087 4/1967 Munder et al. [72] Inventors: Johannes Joseph Vanheertum, Halle-Zand- 3,475,169 10/1969 Lange ..96/1

hoven;'Albert Lucien Poot, Kontich; Jozef Frans wm w wilhelmus FOREIGN PATENTS OR APPLICATIONS Janssens, Aarschot, all of Belgium 788,892 7/1968 Canada [73] Assignee: Gevaert-AGFA N.V., Mortsel, Belgium Primary ExaminerGe0rge F. Lesmes [221 Flled: AssistantExaminerJohn c. Cooper, 111 21 AppL 22,376 Attorney-William J. Daniel 57 ABSTRACT [30] Foreign Application Priority Data 1 Electrophotographic recording process wherein a pattern of 5; Great i i "l increased conductivity is produced image-wise in a photocon- Great Bmam 2961/69 ductive insulating recording layer using as the essential photoconductive compound guinolin-Z-one, quinolin-4-one, [52] 25 3 certain analogs and structural derivatives thereof, as well as 260/287 260/288 260/289 the bis forms thereof, dispersed in an insulating binder. At [51] Int Cl 3 5/06 least about 10 percent by weight of the recording element is [58] Fie'ld 5 constituted by the photoconductive compound and a spectral sensitizing agent for the photoconductor can be included. This class of photoconductors is also useful in the production of phosphor patterns on cathode-ray tube screens.

33 Claims, N0 Drawings RECORDING PROCESS USING QUINOLIN-Z-ONE OR QUINOLlN-4-ONE ORGANIC PHOTOCONDUCTIVE SUBSTANCES The present invention relates to recording and reproduction of information-wise modulated electromagnetic radiation and to recording materials applied therefor. More particularly the present invention relates to a photographic recording process utilizing the property of photoconduction of substances as described herein.

A recording element having photoconductive properties and a sufficient insulating power in non-irradiated state can be used for the production of an electrostatic image.

Electrophotographic materials comprising a support and a photoconductive layer containing .an inorganic or organic photoconductor, e.g. selenium, zinc oxide, anthracene, and particular heterocyclic compounds, are well known.

In the production of opaque photoconductive layers generally inorganic photoconductive substances are used, while for preparing transparent photoconductive layers mostly organic photoconductors are applied.

One of the important problems in the production of transparent photoconductive layers is to find organic photoconductive substances that have a photosensitivity comparable with that of commonly used inorganic photoconductive substances and that are easily spectrally sensitizable over the whole visible spectrum range.

An object of the present invention is the use in electrophotographic recording materials of organic compounds that are photoconductive and are easily spectrally sensitizable.

group wherein R" and R" each represents hydrogen, an alkyl group including a substituted alkyl group, an aralkyl group including a substituted aralkyl group, a cycloakyl group including a substituted cycloalkyl group, an aryl group including a substituted aryl group, an acyl group including a carboxylic acid acyl and sulphonic acid acyl group both either or not in substituted form, a carbamoyl group (CONl-l,) or a substituted carbamoyl group,

Z represents the necessary atoms making part of a carbon chain that closes the nitrogen-containing heterocyclic ring including such ring in substituted form and such ring that makes part of a fused ring system,

n is one or two.

The present invention includes also the use in a recording and reproduction process of the tautomeric structures of said compounds. Tautomeric structures are derived from said compounds wherein R represents hydrogen.

Compounds within the scope of said general formula and that are suitable for use according to the present invention are photoconductive compounds of the quinolin-Z-one and quinolin-4-one series and compounds structurally derived therefrom wherein the oxygen atom in the 2-one and 4-one group is substituted with a sulphur atom, a dicyanomethylene group, an imino group including an imino group substituted with a carbocyclic or heterocyclic radical of aromatic nature, an oxime group, a hydrazone group or a substituted hydrazone group.

Representatives of said quinolin-Z-one and quinoline-4-one compounds and structural derivatives thereof are within the It is another object of the present invention to use such elec- L scope of the following structural formulae (A) and (B):

trophotographic recording materials in photographic recording processes according to which an electrostatic image is formed.

It is still another object of the present invention to provide transparent and semitransparent photoconductive recording elements of particularly high photosensitivity in the ultraviolet range as well as in the visible spectrum range.

Other objects and advantages of the present invention will become apparent from the description but are not limitative for the use of the defined compounds in electrophotographic recording and reproduction processes.

According to the recording process of the present invention a pattern of increased conductivity is produced in a photoconductive insulating recording element containing a heterocyclic organic photoconductive compound having the following structural formula:

I mm RiI"I(L1= 2)n-1 i wherein:

L and L each represents a methine group including a substituted methine group or a carbon atom that makes part of a homocyclic ring, e.g. a benzene ring including a substituted homocyclic ring,

R represents hydrogen, a hydrocarbon group including a substituted hydrocarbon group, e.g. an alkyl group, an aralkyl group, a cycloalkyl group, and an aryl group including said groups in substituted form,

X is an electronegative (electron-attracting) substituent e.g. oxygen, sulphur, an imino group including an imino group substituted with a carbocyclic or heterocyclic radical of aromatic nature, a

GN group, an oxime group, particularly a NOR group wherein v R is hydrogen or an aliphatic group, e.g. an alkyl group, or a hydrazone group or a substituted hydrazone group particularly a /RII III: (B) R1 group, an oxime group, particularly a NOR group wherein R is hydrogen or an alkyl group, or a hydrazone group or a substituted hydrazone group particularly a group, and R" and R each represents hydrogen, an alkyl group including a substituted alkyl group, an aralkyl group including a substituted aralkyl group, a cycloalkyl group including a substituted cycloalkyl group, an aryl group including a.

substituted aryl group, an acyl group including a carboxylic acid acyl and sulphonic acid acyl group either or not in substituted form, a carbamoyl group (CONH,) or a substituted carbamoyl group,

Z represents the necessary atoms making part of a carbon chain that closes the nitrogen-containing heterocyclic ring including such ring in substituted fonn and such ring that makes part of a fused ring system; examples of substituents for the ring closed by Z are alkyl, e.g. methyl, substituted alkyl e.g. trifluoromethyl, halogen e.g. chlorine and fluorine, an amino group, a substituted amino group e.g. a dialkylamino group, a hydroxyl group, an alkoxyl group e.g. a methoxy group, a carbamoyl group, a substituted carbamoyl group e.g. a CONHCl-i group, an aminoacyl group e.g. a NHCC H, group, a sulphamoyl group, a N-substituted sulphamoyl group e.g. a --SO N(CH group, a sulphonylfluoride group, a car bonylalkoxy group e. g. a carbethoxy group,

R represents hydrogen, a hydrocarbon group including a substituted hydrocarbon group, e. g. an alkyl group including a substituted alkyl group e.g. a C C alkyl group, an aralkyl group including a substituted aralkyl group, a cycloalkyl group including a substituted cycloalkyl group, an aryl group including a substituted aryl group, an ester group e.g. a carbonylal- I koxy group such as a carbethoxy group, a carbamoyl group including a substituted carbamoyl group, an amino group including a substituted amino group,

R represents hydrogen, a hydrocarbon group including a substituted hydrocarbon group e.g. an alkyl group including a substituted alkyl group e.g. a C -C alkyl group, an aralkyl group including a substituted aralkyl group, a cycloalkyl group including a substituted cycloalkyl group, an aryl group including a substituted aryl group, a carboxylic acid group, an ester group e.g. a carbonylalkoxy group such as a carbethoxy group, or a carbarnoyl group including a substituted carbamoyl group, and

R and R together represent the necessary atoms to close a homocyclic ring including such ring in substituted form or making part of a fused ring system.

Compounds according to the above general formulae that are suitable for use in the manufacture of an electrophotographic recording material according to the present invention are listed in the following Tables I, II and III. In Table III duplo structures are exemplified.

Said heterocyclic compounds, e.g. those containing the quinolin-2- or 4-one ring system can be introduced into a polymeric chain by known methods, e.g. by introducing in said i system an a,B-ethylenically unsaturated group and by applying a subsequent proper ionic or radical polymerization, or by linking said ring system to an already existing polymer chain by means of an addition or substitution reaction, e.g. by using polyvinylbenzyl chloride whose chlorine atoms have been substituted with an active hydrogen atom of the quinolin-2- or quinolin-4- compounds.

Polymers containing heterocyclic organic systems for the purpose of the present invention have not to be of a high molecular weight in order to obtain a practical useful photoconductivity.

The photoconductive heterocyclic compounds used according to the present invention are prepared according to methods known per se. As an illustration of the preparation of quinolin-Z-one compounds, also called carbostyril compounds, reference is made to the published Dutch Pat. Specification No. 6,603,985 filed Mar. 25, 1966 by Farbenfabriken Bayer AG. corresponding with the Canadian Pat. Specification No. 788,892 filed Mar. 24, 1966 by Farbenfabriken Bayer AG.

The preparation of particular quinolin-4-one compounds is described, e.g., in the French Pat. Specification No. 1,202,105 filed June 14, 1956 by Badische Anilin- & Soda-Fabrik A.G., Chem. Abstracts 61 (1964) 10657 e, J.Org.Chem. 23 (1958) 762-763, and J.Prakt.Chem. I 7 (1962) 135-146.

Preferred photoconductive compounds are quinoline compounds, that contain the above indicated value for X and an electron-donating (electron-rich) substituent e.g. a hydroxy, amino, alkyl substituted amino, alkoxy or alkyl group. In preferred compounds a dialkylamino group is present as a substituent on the aromatic ring part of the quinolin-Z-one or quinolin-4-one compound, or photoconductive derivatives thereof. The quinolin-2-one and quinolin-4-one compounds are further preferably substituted in the o-position to the X substituent with a substituent having an aromatic character, e.g. a phenyl group or a substituent having an electronwithdrawing character such as a nitro group. For substituents TABLE I Melting point,

Number I I I I I I I l I I I l l I I l I I I I l l I I I I I I I I l l I I I I I I I I l I I I I I I I I I I I I I I I I I I I I I I I I I l I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I l I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I l I I I I I l I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I l I I I I l I I I I I I I I I I I I I I I I I I I l I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I IIIII I I I I I I I I I I I I I I I I I I I I I I I I I l I I I I I I I I I I I I I I I I I I I I I I I I I IIIII I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I l I I l I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I l I I I I I I I I I I I I I I I I I I IIIII zit-.255

CeH

mHO 2 2 mm m m 5 0 m m 2 10% &0 m n O 2% 05m 2 2 2 EoQ A y $0 m m m m 2 Q m2 o onawwoflaw 1.2... n m mmc nmo mm n mmv c: 5 0522 2 00 m n G 50 @N 83 506wmz2 m m 0520 m m 50 x 3 8 m m m m m 6% 2 5m 0 l E 2 m m m m m 2 8E 8 m m 200 m m EQW Q 50 3 s 5 m m 05m m n O 8 83 28.2.. m m 50 m m 235G 8H m 2 13 m m m Hm HHWHWMH H n 56 E E m n mfin 2 5 0 "m0 2g 3 m m 2 2 2 2 2 2 2 m 50 2 m2 fifii fi w m m -ifiovzm 2 m 2 2 m 56 50 M:

8H m o owmz z E0 m m H H H H H EO 2 03A o E0 m 2 o 3N o E0 m 2 a? o $8 G m a 2: o m m m 2222222 m m 5 0 a N E i m SH SH S Sm 59:52 $500 des n-803 I2 02 O v m mm mm mm IIQZEQ wd m flO 0m wwm HHOZ E m mm n i Q mo aw 259% 8" 8- m m m ow m m 2580 .........E0 8 m2 3 m umow m m 5 0 E6 2 own I. 0 m mm 10w Hm mm mo wm 5 0 \ZT OO ma w HH m mm n mm H1O mO 2 an" 6' m m 'H Om mm MH O -Q ma m i. HHU

an I 1 u m mm mm 1 m "HMO 9 ma .leboammwawm HH mm n I. mm AEQO mm .1. mU m* 52 6 580 8H W O OWHMZ Z m mm Hm Hm m QmU "awn- \Z O m 0 wiZ Z mafia" "m0 mm m Hfl Om n mm M H O mO 0w ESTO EBo mam. w m mm Hm mm m mo am ":0 mzoo 02A, w m Hm m ":0 mO mn 5o Q O ESQ 05 w 5 m. HH m mm 29 2" ca w mm mm HH HH mo l wm EN iomvl E n MH UOOO HH mm m o HHU mm 00m. fi Hm mUmzOo n HH E O mO v 0 a M 3H 3H m Sm m SW i 82:52 509 TABLE} II H -CH=CH-'CH=CH- I S. 133 =N-NHCOOCH3 159 =N-NHSOz- =N--NHSOgCnH;a 109v Same as above 122 127 =N-NH-,S CH

2 CH3.. H CuHaL; HJLH... H IL... =N-NHCONH2 160 21..." CaHs H.; CH3 H..1H H 11.... Z12

=N-NHSO CH:

22..-" c5115."; H CH3 H.; H HI. B...- :25

=N-NHCO 23"... CH H HQ; H H; H.... 250

\ NH? =N-NHSO NHCOCH;

Mn." C 3 H CH3. H.. C11 0... H. H.... :N-NHg 1 25...... CH: H CH L. H H 1-1.... 2 5

=N-NH s 0 -0H3,

26"-.- CH1 H CH HQ. H CH; 1-1...- CN 21 CH;' CN

H'...CH5' H... 207 116 H; H Hie 120 H.. (C2H5):- H; 112 H H; CH 11.. C H

CHL. H

TABLE III 7 H Sameasabove H Same as above,. H do with electron-donating an electron-withdrawing character reference is made to Peter Sykes, A Guidebook to Mechanism in Organic Chemistry Longmans, London (1963) p. 106-107.

Such preferred compounds are e.g. l-ethyl-3phenyl-7- dimethylamino-quinolin-Z-one, l-ethyl-3phenyl-7- diethylamino-quinolin-Z-one and which are also called 1- ethyl-3-phenyl-7-dimethylaminocarbostyril and l-ethyl-3- phenyl-7-diethylaminocarbostyril respectively. The former compound can, e.g., be prepared as follows, the parts being by weight:

17.9 parts of 2-ethylamino-4-nitroltoluene, 16.2 parts of phenylglyoxylic acid ethyl ester, and 2 parts of pipcridine are heated for 8 hours to 200 C with stirring.

18 parts of the resulting 1-ethyl-3-phenyl-7-nitrocarbostyril in a mixture of 50 parts of alcohol and 50 parts of concentrated hydrochloric acid are heated on a waterbath. A solution of 50 parts of tin(ll) chloride in 100 parts of concentrated hydrochloric acid is added to the mixture with stirring. Stirring is continued for 1 hour, whereupon the mixture is allowed to cool. The resulting l-ethyl-3-phenyl-7-aminocarbostyril is filtered ofl, boiled out with 200 parts of 5 percent aqueous solution of sodium hydroxide, filtered while hot, dried, and recrystallized from xylene. From the resulting l-ethyl-3-phenyl-7-aminocarbostyril(melting point: l70-l72 C) 13.2 parts are dissolved in 150 parts of dioxane. To the solution are added parts of percent solution of formaldehyde in methanol and 10 parts of Raney nickel. The mixture is heated for 4 hours to 1 10 C in an autoclave with a hydrogen pressure of 1 l0 atrn. Subsequently, the Raney nickel is isolated and the dioxan is distilled in vacuo. After recrystallization from cyclohexane l-ethyl-3-phenyl-7-dimethylaminocarbostyril is obtained. Melting point: l09-l 12 C.

The following products listed with their respective melting point are prepared in an analogous way by a condensation reaction of the proper 2-amino-4-nitrotoluene and phenylglyoxylic acid ethyl ester.

3-phenyl-7-dirnethylaminocarbostyril (258-262 C), lrnethyl-3-phenyl-7-aminocarbostyril (l90l92 C), l-

methyl-3-phenyl7-dimethylaminocarbostyril (l-l73 C),

l-methyl-3-(4'-methylphenyl)-7-dimethylaminocarbostyril 6o (l-90 C), l-methyl-3-(4'-methylphenyl) 6-methyl-7- dimethylaminocarbostyril (152-153 C), l-methyl-3-(3,5- dimethylphenyl)-7-dimethylaminocarbostyril (l5 l-153 C), l-ethyl-3-( 3 '-chlorophenyl)-7-dimethyl-aminocarbostyril (l6l-62 C), l-ethyl-3-phenyl-7-monoethylaminocarbostyril (l78-l 80 C), l-ethyl-3-phenyl-7-N-methyl-N- ethylarninocarbostyril (75-78 C).

In the resulting nitrocarbostyrils the nitro group is reduced to an amino group, which for the purpose of the present inven- 70 tion preferably is alkylated.

The alkylation for preparing l-ethyl-3-phenyl-7- diethylarninoquinolin-2-oncpreferably is carried out as fol- I lows:

hours on an oil-bath at C.

79.2 g (0.3 mole) of l-ethyl-3-phenyl-7-amino-quinolin-2:1 v 75 one and 109 g (0.6 mole) of triethyl phosphite are heated for 3 5 The reaction mixture is poured into 1 l of water and the whole composition is alkalized by means of a N aqueous sodium hydroxide solution. The resulting precipitate is isolated and dissolved in 300 ml of warm acetone. A cooling 75.5 g of purified I-ethyl-3-phenyl-7-diethylamino-quinoline-2-one precipitated. Melting point: 1 C (yield: 78 percent).

As an example illustrative for the preparation of a quinoline-4-one the preparation of the compound 8 of Table I is given hereinafter.

This compound was prepared as follows. A mixture of 26 g of methyl ester of p-fluorosulphonyl-benzoylacetic acid, 21.2 g of p-benzoylamido aniline, 300 ml of chloroform and 1 ml of strong hydrochloric acid was refluxed for 8 days with a separator in order to remove the water formed in the reaction mixture. The precipitate formed was filtered off and the chloroform removed by evaporation in vacuum. The reaction product having the following structural formula:

was isolated as an oily residue.

, This residue was added dropwise to 300 ml of boiling (250 C) DIPHY L (trade name of Farbenfabriken Bayer AG, Leverkusen, W. Germany, for a mixture consisting of 27 percent by weight of diphenyl and 73 percent by weight of diphenyl oxide). The reaction mass was maintained for 5 minutes at the boiling temperature of DIPHYL (250 C) while methanol was distilled. Then the reaction mass was cooled. The precipitate formed was filtered with suction, washed with methanol and ether and dried. Yield: 10.5 g of compound 8 of Table I. Melting point: above 260 C.

As an example illustrative for the preparation of duplo" compounds listed in Table III the preparation of compounds 5 and l l of said table is given hereinafter.

Preparation of compound 5 of Table III g (0.1 mole) of 4,4'-diamino-diphenyl oxide and 52 g (0.2 mole) of methyl ester of p-fluorosulphonyl-benzoylacetic acid were melted together, whereupon 5 g of polyphosphoric acid as water-attracting product were gradually added thereto while stirring.

The reaction mixture was maintained for 10 days at 50 C under vacuum conditions and kept away from contact with moisture from outside by means of a trap containing concentrated sulphuric acid. Thereupon the reaction mass was stirred into chloroform and filtered. The chloroform solution obtained was washed with water and dried on anhydrous sodium sulphate. The chloroform was removed by evaporation in vacuum. The residual product having the following structural formula:

SOzF

SOQF

was separated in the form of an oil.

This oil was added dropwise to 400 ml of boiling DIPHYL (trade name). The reaction mass was maintained for 5 min. at the boiling temperature of DIPHYL (trade name) with stirring, and then cooled till 20 C. The precipitate formed was filtered with suction, washed with methanol and ether, and dried. Yiled: 7.l g of compound 5 of Table III. Melting point: above 260 C.

Preparation of compound 1 1 of Table In A mixture of 25.7 g (0.1 mole) of the hydrochloric acid salt I of 4,4'-diamino-diphenyl and 54.8 g (0.2 mole) of ethyl ester of fluorosulphonyl benzoylacetic acid, 13.2 g (0.19 mole) of waterfree sodium acetate and 150 ml of chloroform were refluxed for 7 days. Then the chloroform was removed by evaporation under vacuum. The product having the following structural formula:

was separated oil. oil was added dropwise to 400 ml of DIPHYL (trade name). The reaction mass was maintained for 5 min. at the boiling temperature of DIPHYL (trade name) with stirring and then cooled till 20 C. The precipitate formed .was filtered with suction, boiled with acetonitrile, washed with methanol and ether, and dried. Yield: 10.2 g of compound ll of Table III.

Quinoline-Z compounds as described in Table II and wherein X is sulphur can be prepared e. g. according to the following reaction scheme A:

The R, R, R and R substituents may have the significance of the corresponding substituents of the general formula above Table II.

Equimolar amounts of ketoesterfl) and aromatic amine (II) are dissolved in xylene contained in a distillation flash provided with a fractionating column. The reaction mass is heated till the theoretical amount of alcohol produced in the reaction is distilled off. After removal of the solvent by evaporation the obtained product (III) is purified by crystallization.

Product (III) is dissolved in concentrated sulphuric acid (1,350 ml per mole) and the reaction mass after having been kept for 24 H. at room temperature is poured onto ice. The precipitate formed is isolated by suction, washed with water, whereupon product (IV) is recrystallized.

Product (IV) is mixed with an equimolar amount of p-tolusulphonic acid alkyl ester and heated for to h. at about C. Thereupon the reaction mass is treated with an aqueous lN sodium hydroxide solution. The precipitate formed is separated by suction and the obtained product V is purified by crystallization.

This product is then dissolved in pyridine containing anexcess (1.2 mole per mole) of phosphorus pentasulphide and maintained at reflux temperature for l to 3 h. After cooling the reaction mass is poured into water, and the precipitate formed is separated by suction, and washed. The obtained product (VI) is purified by crystallization.

Compounds 10, l2, [4, 34 and 35 of Table II have been prepared that way.

Quinoline-Z compounds as described in Table II, and wherein X is sulphur, can also be prepared according to the following reaction scheme B:

RI!!! RIII RCO ore-coon HI L-Q IIR'II Rl/I/ RI! R!!! l H2804 RC CH0 ()N (III) R/II R!!! I I N N 0 Pass s RI/I! I RI!!! RI] RI! The substituents R, R, R", R' and R"" may have the same significance as the corresponding substituents exemplified in the structural formula above Table II.

The operating conditions are the same as explained for reaction scheme A except for the alkylation reaction with ptolusulphonic acid alkyl ester.

The compounds ll, 13 and 36 of Table II were prepared that way.

Quinoline-4 compounds as described in Table I, and wherein X is sulphur, can be prepared according to the following reaction scheme C:

1'3 6 1 N N N @3 R1 I Q3 S W R2 (I) (II) (III) R 1 represents an alkyl iodide e.g. methyl iodide.

According to said reaction scheme C, compound 16 of Table I was prepared as follows:

2-methyl-4-chloro-quinoline (I) was mixed with an excess of methyliodide (5 mole per mole) and the reaction mass was maintained at reflux temperature for 35 h. Then the reaction mixture was washed with ether.

Compound (II) wherein R and R were both methyl was obtained in 67 percent yield in the form of a crystalline product melting at 250 C.

This product was dissolved in dry ethanol (1,600 ml per mole) and maintained at reflux temperature for 12 hours in admixture with an excess of sodium hydrogen sulphide (3 moles per mole).

The reaction mass was filtered hot and cooled. Compound (III) (R, and R, being both methyl) crystallized, whereupon it was recrystallized from ethylene glycol monomethyl ether. Yield: 59 percent. Melting point: 224 C.

The quinoline compounds wherein X is an oxime group can be prepared according to a known method for producing an oxirne, e.g. as described by Vogel in Practical Organic Chemistry, 3rd Ed. Longmans, (1959) 741.

According to another method the reaction scheme D is followed:

Preparation of compound (II) 2-phenyl-4-chloro-quinoline is mixed with an excess (3 mole per sole) of dirnethyl sulphate and for 24 hours heated at C. After cooling and washing with ether, the compound (II) is obtained in a quantitative yield. Melting point: 50 C. Preparation of compound (III) 0.02 mole of compound (II), 0.04 mole of sodium carbonate and 0.03 mole of hydroxylammonium chloride are dissolved in a mixture of 50 ml of chloroform and 25 ml of methanol and refluxed with stirring for 2 h. After cooling the precipitate is separated by suction and washed with water. This washed precipitate consisting of compound (III) was crystallized from ethylene glycol monomethyl ether. Yield: 50 percent. Melting point: 258 C.

The quinoline compounds wherein X is an imino group substituted with an aromatic group can be prepared according to known methods for producing a ketone anil, e. g. according to reaction scheme E as follows:

Ar-NH:

Compound II of reaction scheme D OH Ar is e.g. a phenyl group.

Preparation of compound (111) wherein Ar=phenyl. Equimolar amounts of compound (H) and aniline are dis solved in chloroform and refluxed for ,4 h. Then the chloroform is evaporated under vacuum and the residue is treated with a 20 percent by weight aqueous solution of sodium carbonate. The solid product is separated by suction, washed and dried. The yield is quantitative. Melting point of compound (11! (Ar being phenyl): l50 C.

The quinoline compounds wherein X is a hydrazone group can be prepared according to a known method for producing a hydrazone compound starting from a ketone.

Acyl-substituted hydrazone groups in the 2-position of quinoline can be introduced according to preparation methods described in the U.K. Pat. Specification No. 993,749 filed July 30, 1962 by Gevaert Photo-Producten N.V., the U.S. Pat. Nos. 3,245,787 issued Apr. 12, 1966 of Jozef Frans Willems and ,Jan Jaeken and 3,293,032 issued Dec. 20, 1966 of Jan Jaeken and Maurice Antoine de Ramaix and the UK. Pat. ap-

plication Ser. No. 5979/69 filed Feb. 4, 1969 by Gevaert-Agfa N.V.

Acyl-substituted hydrazone groups in the 4-position of quin oline can be introduced according to reaction scheme F:

17 /N\\ HzNNHCOR l l l COR 4J1 I lNH or SO R R represents a hydrocarbon group or a heterocylic group which groups may be further substituted. Compound (I) together with an equimolar amount of R'CONHNH or R SO NHNH is refluxed in ethanol for 8 h.

Thereupon ethanol is removed by evaporation. The residue is dissolved in pyridine and min. later the obtained solution is poured into ater. The precipitate formed is separated by suction, washed with water, and crystallized.

The compounds wherein X is a dicyanomethylene group can be prepared by allowing to react propane dinitrile with the appropriate heterocyclic quaternary salt having a methylmercapto group in ortho position to the quaternary nitrogen atom. The reaction conditions for such preparation can be learned from the preparation of N-isopropyl-4,7-dimethyl-quinoline- Z-dicyanomethylene.

3.4 g of N-isopropyl-2-methylmercapto-4,7-dimethylquinolinium iodide together with 1.2 g of propane dinitrile were dissolved in a mixture of 30 ml of pyridine and 0.3 ml of piperidine. The reaction mixture is kept at C for 24 h. and thereupon poured into water.

The precipitate formed was filtered with suction, washed with water and dried. Melting point: 21 1 C. Yield: 2 g.

The photoconductive compounds applied according to the present invention may be used alone or in combination with substances imparting desired chemical or physical properties to the recording element. So, these substances can be combined with other substances, that either or not are photoconductive and exert an influence e.g. on the dark-resistivity, the dischargeability or conductivity of the recording layer by an exposure to electromagnetic radiation, or on the transparency or the quality of the final image, e.g. by counteracting the fringe effect as described in the U.K. Pat. Specification No. 1,007,349 filed Oct. 12, 1961 by Gevaert Photo-Producten N.V.

The photoconductive compounds used according to the present invention are preferably applied in admixture with (a) compound(s) that cause(s) an increase of the general sensitivity and/or of the sensitivity to electromagnetic rays of a particular part of the spectrum.

' Fringe effect occurs when large electrostatically charged areas are developed and is characterized by the deposit of electrostatically charged substances only at the edges of said areas. In order to inhibit or to decrease said effective dispersable particles, e.g. inorganic pigment particles and organic water-insoluble particles, are incorporated into the continucaco 54.34 MgCO 45.15 F5203 0.04 A1203 0.03

5 and DRY-FLO (trade name of National Starch and Chemical Corporation, Plainsfield, N.J., U.S.A., for a starch ester containing hydrophobic groups).

These particles size between 1 and 5 p. and are preferably used in an amount of 2.4 to 24 percent by weight in respect of the homogeneous phase material contained in the recording layer. Optimal results are obtained with an amount of 6 percent by weight.

A proper combination with selected binding agents and/or curing agents may result in an enhancement of the total sensitivity so that the binder or curing agent applied may be considered as a sensitizing agent. Preferably the recording layer contains at least 10 percent by weight of the photoconductive substance applied according to the present invention. The electrically insulating binding agent applied to ofl'er to the recording layer the desired mechanical strength preferably has a resistivity of at least 10 ohm/cm.

According to a particular embodiment the recording layer consists of the photoconductor, which, e.g., is applied to a 25 suitable support in molten state forming a microcrystalline or glass-like layer on cooling. This technique can be applied when the photoconductive recording element has not to possess a high mechanical strength. For such technique reference is made to the Canadian Pat. Specification No. 712,541 filed Feb. 5, 1960 by Gevaert Photo-Producten N.V.

Macromolecular compounds suitable for use as insulating binding agent for the photo-conductive compounds are, e.g., natural resins such as dammar resin, gum arable, microcrystalline waxes, modified natural substances such as cellulose diacetate, cellulose triacetate, and ethyl cellulose, pentaerythrite polyesters or modified colophony resins and ester gums, polymerisates such as polyethylene, polystyrene and copolymers of styrene, polyvinyl acetate and copolymers of vinyl acetate, polyvinyl acetals of formaldehyde, acetaldehyde or butyraldehyde, polyacrylic acid esters and polymethacrylic acid esters, coumarine-indene resins; and polycondensates such as glycerol-phthalate resins and other glyceryl polyesters, alkyd resins, diethylene glycol polyesters, formaldehyde resins and silicone resins.

Preferred binding agents are halogen-containing polymers.

The preferred recording materials according to the present invention contain the organic photoconductive compounds in admixture with a halogen-containing polymer. Such polymers and a sensitizing treatment therewith are described in the UK. Pat. Specification No. 964,878 filed May 3, 1960 by Gevaert Photo-Producten N.V. According to said specification a material suitable for use in electro-photography comprises a photoconductive layer incorporating an organic monomeric photoconductor and a halogen-containing polymer in such layer or in a juxtaposed layer (if any), e sensitivity of said photoconductor having been increased by making it to interact with said halogen-containing polymer by heating.

In the following Table IV a list of preferred polymeric binding agents is given, which may be used in combination with the heterocyclic organic photoconductors of use according to the present invention as well as the corresponding suitable solvents.

TABLE IV Polymeric binding agent defined by its structural unit(s) Sulveut CH3 Methylene chloride. :0 ).--0-01s- SO2 nn l C1 i The photoconductive compounds applied according to'the and polymeric organic photoconductors, e.g. those described present invention can be used in admixturewith otheriknown in the published Dutch 'Pat. application Ser. No. 6,901,214 photoconductive substances, e.g. sulphur, selenium, 7o filed-181134, f gfa N-V- photoconductive oxides, sulphides; and selenides of zinc, cad- The inherent I 7 spectra] sensltlvr of ,most of the hotoconmercury mummy m and TINY 'cmbe ductive-compounds listed in Tami- 5 I, n, and III-is mainly situused in combination with organic monomeric photoconducand in th U v tors e.g. anthracene, anthraquinone; polymers 6011mm n g N- mm c near m the range of 360m to 420 vinylcarbazole recurring units and other known monomeric It is possible to increase or extend the spectral sensitivity of recording materials according to the present invention in different ways, e.g. by adding so-cailed spectral sensitizing agents for the photoconductive substances contained in the recording element or by admixing to the said heterocyclic organic photoconductive compounds other photoconductive substances, the inherent sensitivity of which for a particular part of the electromagnetic radiation spectrum is higher than that of said compounds.

So, according to a special embodiment of the present invention semi-transparent recording layers are prepared, in which said heterocyclic photoconductive compoundsare used in admixture with (an) inorganic photoconductive substance(s), especially photoconductive substances of the group of zinc oxide, photoconductive lead(ll) oxide and photoconductive cadmium sulphide.

So, for instance a small amount of an inorganic photoconductive compound such as photoconductive zinc oxide (1.5 g) in respect of 4 g of l-ethyl-3-phenyl-7-diethylaminoquinolin- 2-one ofiers an interesting sensitivity of the recording layer to ultra-violet radiation and allows the extension of the spectral sensitivity of both the heterocyclic organic photoconductor and the inorganic photoconductive substances into the visible part of the spectrum by means d same or difi'erent sensitizing dyestuffs.

Suitable spectral sensitizing dyestuffs for the organic photoconductor are among others organic dyestufis, known as methine dyes, or xanthene dyes of which the phthaleins and rhodamines are subclasses, and triarylmethane dyes e.g. crystal violet (C.l. 42,555) and the triarylmethane dyes described in published Dutch Pat. application Ser. No. 6,704,706 filed Apr. 3, 1967 by Gevaert-Agfa N.V. The term methine dyes includes monoas well as polymethine dyes which dyes are known to those skilled in the art of the spectral sensitization of light-sensitive silver halide. Preferred methine dyes are of the cationic type and preferably contain one, three, five or seven carbon atoms in straight line in the methine part linking up two heterocyclic nitrogen-containing nuclei of the methine dye. As preferred xanthene dyes Rhodamine B (C.l. 45,170), Rose Bengale (C.l. 45,440) and Fluorescein (C.l. 45,350) are mentioned. The spectral sensitizing dyes are preferably added to the recording layer composition in a proportion of 0.01 to percent by weight in respect of the photoconductive substance(s).

Particularly preferred methine dyes are within the scope of the following general formulae:

I. l a 4 halogen and alkoxy, a five or six membered heterocycle the heteroatom of which is oxygen, sulphur, selenium or nitrogen such as 2-, 3-, or 4-pyridyl, 2-furyl, 2-thienyl, etc. including their quaternary salts,

R, stands for hydrogen or has one of the meanings given for 1) R stands for hydrogen, alkyl, alkoxy or halogen or together with R, forms an alkylene bridge such as dirnethylenc and trimethylene,

each of R and R, (the same or different) stands for hydrogen, alkyl, alkoxy or halogen or together represent the atoms necessary to complete a fused-on benzene nucleus; X represents an anion e.g. Cl, Br, 1', C10 CH SO] or HzC-Q-SO'u,

and

Z represents the atoms necessary to complete a heterocyclic nucleus of the types used in the production of cyanine dyes e.g. such as those of the thiazole series e.g. thiazole, 4- methylthiazole, 4-methyl-5-carbethoxythiazole, 4-phenylthiazole, S-methylthiazole, 5-phenylthiazole, 4-(p-tolyl)- thiazole, 4-(p-bromophenyl)-thiazole, 4,5-dimethylthiazole, 4,5-diphenylthiazole, 4-(2-thienyl)-thiazole, 4-(m-nitrophenyl)-thiazole, those of the benzothiazole series, e.g. benzothiazole, 4-chlorobenz0thiazole, 5-chlorobenzothiazole,

6-chlorobenzothiazole, 7-chlorobenzothiazole, 4-methylbenzothiazole, S-methylbenzothiazole, 6-methylbenzothiazole, 5-bromobenzothiazole, 6-bromobenzothiazole, 6-sulphobenzothiazole, 4-phenylbenzothiazole, S-phenylbenzothiazole, 4-methoxybenzothiazole, S-methoxybenzothiazole, -methoxybenzothiazole, 5- iodobenzothiazole, 6-iodobenzothiazole, 4-ethoxybenzothiazole, S-ethoxybenzothiazole, 4,5,6,7-

tetrahydrobenzothiazole, 5,6-dimethoxybenzothiazole, 5,6- dioxymethylenebenzothiazole, 5-hydroxybenzothiazole, 6- hydroxybenzothiazole, 5,6-dimethylbenzothiazole, those of the naphthothiazole series e.g. naphtho[2,l-d]thiazole, naphtho[ 1,2-d]thiazole, 5-methoxynaphtho[ l ,2-d]-thiazole, 5-ethoxynaphtho[ l,2-d]-thiazole, 8-methoxynaphtho[ 2, l -d]- thiazole, 7-methoxynaphtho[2,l-d]-thiazole, those of the thionaphtheno[7,6-d]-thiazole series e.g. 7-methoxythionaphtheno[7,6-d]-thiazole, those of the thiadiazole series e.g. 4-phenylthiadiazole, those of the oxazole series e.g. 4-methyloxazole, S-methyloxazole, 4-phenyloxazole, 4,5- diphenyloxazole, 4-ethyloxazole, 4,5-dimethyloxazole, 5- phenyloxazole, those of the benzoxazole series e.g. benzoxazole, S-chlorobenzoxazole, S-methylbenzoxazole, S-phenylbenzoxazole, -methylbenzoxazole, 5,6-dimethylbenzoxazole, 4,6-dimethylbenzoxazole, S-methoxybenzoxazole, 6-methoxybenzoxazole, S-hyclroxybenzoxazole, 6-hydroxybenzoxazole, those of the naphthoxazole series, e.g. naphtho[2, l -d]oxazole, naphtho[l,2-d]oxazole, those of the selenazole serieseg. 4- methylselenazole, 4-phenylselenazole, those benzoselenazole series e.g. benzoselenazole, 5- chlorobenzoselenazole, S-methoxybenzoselenazole, S-methyl- 6-methoxybenzoselenazole, 5,6-dioxymethylenebenzoselenazole, 5-hydroxybenzoselenazole, 4,5,6,7-tetrahydrobenzoselenazole, those of the pyrimidine series, those of the quinoxaline series, those of the,

quinazoline series, those of the l-phthalazine series, those of the Z-pyridine series e.g. pyridine, S-methylpyridine, 3- nitropyridine, those of the 3,3-dia1kylindolenine series e.g. 3,3-dimethylindolenine, 3,3,5-trimethylindolenine, 3,3,7- trimethylindolenine, etc., those of the benzirnidazole series e.g. benzirnidazole, 5,6-dichlorobenzimidazole, 5- chlorobenzimidazole, 5,6-dibromobenzimidazole, 5-chloro-6- amino-benzimidazole, S-chloro-G-bromobenzimidazole, 5- phenylbenzimidazole, S-fluorobenzimidazole, 5,6-

difluorobenzimidazole, S-cyanobenzirnidazole, 5,6- dicyanobenzimidazole, -chloro6-cyanobenzirnidazole, 5-

fluoro-6-cyanobenzimidazole, 5-acetylbenzimidazole, 5- chloro-6-fluorobenzimidazole, S-carboxybenzimidazole, 7- carboxybenzimidazole, S-carbethoxybenzimidazole, 7-carbethoxybenzimidazole, S-sulphamylbenzimidazole, or 5-N- ethylsulphamylbenzimidazole, S-ethylsulphonylbenzimidazole and 5-trifluoromethylsulphonylbenzirnidazole;

fall]a RI/4 R I 5 u x- R's u wherein:

A stands for monomethine or trimethine including substituted monomethine or trimethine,

each of R -R and R R" (the same or different) has one of the meanings given for R R X -has the same significance as X,.

X 'has the same meaning as X,',

A has the same meaning as A each of m and p (the same or different) stands for one or two, and

each of Z and Z (the same or difi'erent) stands for the atoms necessary to complete a heterocyclic nucleus of the thiazole, benzothiazole, naphthothiazole, thionamhtheno[7,6- d]thiazole, thiadiazole, oxazole, benzoxazole, naphthoxazole, selenazole, benzoselenazole, naphthoselenazole, 2-quinoline, 4-quinoline, pyrimidine, quinoxaline, quinazoline, 2-pyridine, 3,3-dialkylindolenine or of the benzimidazole series,

representative examples of these heterocyclic nuclei can be found above in the definition of Z in formula I.

The dyestuffs corresponding to the above general formulae can be prepared according to the methods known by those skilled in the art of rnethine dye chemistry.

According to a further embodiment of the invention, the recording material contains one or more substances that increase the photoconductivity of the recording material in the inherent spectral sensitivity range of the said heterocyclic organic photoconductive compounds. As already has been said a binding agent or a curing agent can act as a sensitizing agent that enhances the total sensitivity of the recording element. In that respect are to be mentioned compounds containing one or more electron-attracting atoms or groups e.g. the compounds according to the structural formula of the Belgian Pat. Specification No. 734,141 filed June 6, 1969 by Gevaert-Agfa N.V. Particularly suited are chlorine-containing compounds and the chlorine containing polymers of Table IV, and curing agents containing epoxy groups such as the tetraglycidyl ether of tetraphenylene-ethane.

Further have to be mentioned electromagnetic radiationsensitive diazonium salts that on exposure to electromagnetic radiation produce (a) radical(s) that irreversibly increase(s) the electroconductivity of the recording layer. Such substances as well as details about their incorporation into a recording layer containing an organic polymeric photoconductive insulating substance are described in the UK. Pat. Specification No. 964,872 filed Apr. 22, 1959 by Gevaert Photo-Producten N.V. and the US. Pat. No. 3,113,022 of Paul Maria Cassiers, Jean Marie Nys, Jozef Frans Willems and Rene Maurice Hart, issued Dec. 3, 1963. A particularly suitable conductivity-increasing diazonium compound is pnitrobenzene-diazonium chloride. The diazonium compounds are preferably used in an amount of 0.01 to 10 percent by weight in respect of the said photoconductive heterocyclic organic compounds.

Other additives well known in the art of preparing coatings for recording purposes may be used, e.g. matting agents, fluorescing compounds, phosphors, optical brightening agents, agents controlling the adhesive power of the recording layer, agents controlling the elasticity, the plasticity and the hardness of the recording layer, agents controlling the viscosity of the coating composition, antioxidants, gloss-improving agents, etc.

Transparent and semi-transparent recording materials containing the photoconductive heterocyclic organic compounds as described hereinbefore are especially suited for use in recording materials applied for the reproduction of microfilm images. Microfilm images can be copied in contact or enlarged optically on recording materials according to the present invention. According to the type of development, the transparencies obtained (contact copies and enlargements) can serve as negative or positive intermediate print for further printing, e.g. on diazotype materials.

The semitransparent recording materials according to the present invention preferably have an optical density not larger than 0.30 towards visible light or the copying light used in the printing apparatus wherein it is used as intermediate print.

The photoconductive heterocyclic organic compounds described hereinbefore are further especially suited for being applied in the manufacture of pigment images wherein the latter may have the properties of a fluorescent compound or phosphor. As is generally known luminescent phosphors are used in screens of cathode-ray tubes and more particularly in television, X-ray, radar and oscilloscope screens.

In color television screens phosphors of different color have to be fixed on a screen in a particular pattern.

The described photoconductive compounds are successfully used in a process for the production of color television screens as described in the French Pat. Specification No. 1,336,499 filed Sept. 26, 1962 by Compagnie Francaise Thomson Houston. According to the process described in said specification a pattern of a phosphor on a screen-support is produced by the steps of applying to said support a coating of an electroconductive material and to said coating a layer comprising a vaporizable or thermolysable photoconductive compound optionally incorporated in a vaporizable or thermolysable binding agent. On said coating an electrostatic charge pattern corresponding with the pigment pattern to be produced is formed in an electrophotographic way, and the electrostatic charge pattern is developed with non-volatile powder particles that have the desired phosphorescent or luminescent properties. Subsequently the photoconductive layer containing the phosphor powder image is heated in order to remove the volatile substances of the photoconductive recording layer and to make the phosphor pattern adhere to the screen support.

In order to fix the powder image before applying the heating step it is preferably overcoated with a layer of a thennolysable binding agent.

According to said French patent specification photoconductors of the group of anthracene, anthraquinone and xanthone are used. The recording layer may further contain boric acid.

The photoconductors mentioned in the French patent specification are advantageously partly or wholly substituted by the photoconductive substances applied according to the present invention.

Suitable thennolysable binding agents belong to the class of the polyacrylic acid esters and polymethacrylic acid esters e.g. polymethyl methacrylate, polyethyl methacrylate and polyethyl acrylate.

The thickness of the photoconductive layers is not critical but is open to choice within a wide range according to require ments in each individual case. Good results are attained with photoconductive layers of a thickness between 1 and 20 p.

preferably between 3 and .1.. Too thin layers do not have a sufficient insulating power, in the absence of active electromagnetic radiation whereas too thick layers require extensive exposure times.

In the manufacture of electrophotographic recording materials according to the present invention, a relatively conductive support for the recording layer is used, e.g. an electroconductive sheet or plate, or an insulating sheet or plate covered with an electroconductive interlayer. Under electroconductive plate or sheet is understood a plate or sheet whose electrical resistivity is smaller than that of the non-irradiated (dark-adapted) photoconductive layer i.e. in general smaller than 10ohm/cm and preferably is at least 100 times as small as that of the recording layer. Supports whose resistivity is not higher than 10 ohm/cm are preferred. The recording layers itself have preferably an electrical insulating power as high as possible without affecting too much the photosensitivity by means of a too high amount of insulating binding agent. Preferably the recording layers have in non-irradiated state (dark adapted state) a resistivity of at least 10 ohm/cm.

Suitable conductive plates are, e.g., plates of metals such as aluminum, zinc, copper, tin, iron, or lead.

Suitable electroconductive interlayers for insulating supports are, e.g., vacuum-coated metal and conductive metal compound (metal oxide or metal salt) layers such as silver, tin aluminum, titanium dioxide and copper iodide conductive layers, transparent conductive polymer layers, e.g. applied from polymers containing quaternized nitrogen atoms, such as those described in the UK. Pat. Specification No. 950,960 filed Sept. 23, 1960 by Gevaert Photo-Producten N.V. or layers containing conductive particles, e.g. carbon black and metal particles dispersed in a binder. The binder used for said particles has a resistivity preferably lower than 10 ohm/cm. A suitable binder for that purpose is gelatin,

It is possible to produce transparent photoconductive recording materials by applying the photoconductive compounds together with a suitable binder- (if necessary) from a clear solution to a conductive transparent base or a transparent insulating base coated with an electroconductive transparent interlayer.

As transparent bases resin sheets having an optical density of not more than 0.10 are preferred, e.g., a sheet made of polyethylene terephthalate or cellulose triacetate. The conductive interlayer preferably consists-of a metal coating, e.g., a vacuum-coated aluminium layer having an optical density of not more than 0.30 or of a conductive transparentpolymer layer composed, e.g., of an organic polyionic polymer, e.g. a polymer containing quaternized nitrogen atoms such as a quaternized polyethylene-imine.

In reproduction techniques wherein the prints are to be produced on an opaque background preferably a paper sheet is used as support for the recording layer.

Paper sheets that have an insufficient electrical conductivity are coated or impregnated with substances enhancing their conductivity, e.g. by means of a conductive overcoat such as a metal sheet laminated thereto.

As substances suited for enchancing the conductivity of a paper sheet and which can be applied in the paper mass are Paper sheets are preferably impermeabilized to organic solvents, e.g. by means of a water-soluble colloid or by strongly hydrating the cellulose fibers such as in the case of glassine p l ectrophotographic materials according to the present invention can be used in any of the difierent techniques known in recording with the aid of photoconductors. According to a preferred embodiment they are used in a technique based on the discharge of an electrostatically charged recording layer by exposure to light.

Photoconductive recording materials prepared according to the present invention can be used in exposure units equiped with incandescent lamps, so that they neednot be exposed with light rays rich in ultraviolet such as those emitted by a high-pressure mercury vapor bulb.

The electrostatic charging of photoconductive recording elements according to the present invention can be efiected according to any method known in electrophotography, e.g. by friction with a smooth material, with a material possessing a high electric resistance, e.g. a cylinder coated with polystyrene, by corona discharge, by contact charge, or by discharge of a capacitor.

Recording materials containing the said organic photoconductive substances can be used in a recording technique comprising a negative corona charging as well as in a recording technique comprising a positive corona charging.

In order to obtain an electrostatic image, it is possible to effect the charging and exposure steps simultaneously and even to expose the recording layer image-wise before charging since a conductivity image is formed that is not destroyed immediately, especially if diazonium salts are used in the recording element. It is preferred, however, that the charging is effected before image-wise exposure.

The electrostatic latent image can be converted into a visible image either on the electrophotographic material wherein the latent image was formed, or on a material to which the electrostatic latent image was transferred, e.g. by application of the method described in the Belgian Pat. Specification No. 529,234 filed May 29, 1954 by Battelle Development Co.

The conversion of the original or transferred latent image into a visible image can occur according to one of the techniques known in electrophotography, wherein use is made of a conductivity pattern (e.g. electrolysis) or the electrostatic attraction or repulsion of finely divided colored substances, which, e.g. are present in a powder mixture, in an electrically insulating liquid (e.g. in the form of a suspension) or in a gas (e.g. in the form of an aerosol), or wherein electrostatic attraction is used for selectively wetting charged portions of the recording layer, as described in the U.K. Patent Specification Nos. 1,020,505 filed Nov. 8, 1961 and 1,033,419 filed Nov. 26, 1962 both by Gevaert Photo-Producten N.V.

When the sign of the charge of the developing powder or developing liquid is properly chosen, either a negative or a positive print can be obtained from any original. If both printing material and developing powder or developing liquid have the same sign of charge, the powder only adheres to the discharged areas so that a negative print is obtained. If the signs of the recording material and of the developing powder particularly mentioned hygroscopic compounds and antistatic 01' de pi g l q i fi' a po i p in is Obtainedagents as described, e.g., in the U.K. Pat. Specification No. 964,877 filed May 2, 1960 by Gevaert Photo-Producten N.V., and antistatic agents of polyionic type, e.g. CALGON CON- DUCTIVE POLYMER 261 (registered trademark of Calgon Corporation, lnc., Pittsburgh, Pa., USA. for a solution containing 39.1 percent by weight of active conductive solids, and which contain a conductive polymer having recurring units of the following type:

If a colored powder is used for making visible the latent image, the visible image obtained can, if necessary, be fixed according to one of the methods known in electrophotography, e.g. by heating, or it can be transferred to another support, e.g. according to the method described in the UK. Pat. Specification No. 658,699 filed Apr. 14, 1949 by Battelle Memorial Institute, and fixed thereon.

The said heterocyclic (Iganic photoconductive compounds can also be applied in a thermoplastic recording process to form a ripple-image as described, e.g., in the UK. Pat. Specification No. 964,881 filed May 17, 1960 by Gevaert Photo- BEEF?" -Y;

Evidently, the present inventionby no r rieans is limited to one or other particular embodiment of using the electrophotographic material containing the photoconductive compounds as described herein. The exposure technique the charging method, the formation of the charge pattern, the transfer of such pattern if applied, the developing method, and the fixation or the transfer of the developing material pattern may be modified or adapted.

The composition of the recording materials used in these methods may be adapted to the requirements of the recording process used.

Electrophotographic materials according to the present invention can be employed in reproduction techniques, wherein different kinds of electromagnetic radiations are used, e.g. visible light, U.V. light, X-rays and 'y-rays.

In order to prepare an electrophotographic material according to the present invention various techniques may be applied.

In practice, the photoconductive substances involved, either alone or together with other additives such as those described above, preferably are first dissolved or dispersed in a suitable organic solvent such as a ketone, e.g. acetone, chlorinated hydrocarbons, e.g. methylene chloride, and aliphatic esters, e.g. ethyl acetate, or in a mixture of two or more of such solvents. The solution or dispersion thus obtained is uniformly spread on a surface of a suitable support, e.g. by centrifuging, spraying, brushing, or coating. Thereupon the layer formed is dried in such a way that a solid photoconductive layer is formed on the surface of the support.

With regard to the structure of the photoconductive compounds used according to the present invention we do not limit said compounds to the particular atoms and groups that have been indicated already for the value of the bivalent substituent X. Indeed, X may be any atom or group having an electronegative character with respect to the carbon atom of the quinoline nucleus to hich it is attached in the 2- or 4- position. So, in addition to the atoms and groups already mentioned we include also e.g. for the meaning of X each group introduced by means of an active methylene compound and wherein the carbon atom of the active methylene compound becomes double bonded to the quinoline nucleus in the X substituent position, For example the group wherein each of Q and Q represents an electronegative substituent e.g. a cyano group, an aryl group an acyl group e.g. a benzoyl group, a carboxylic ester group, an amide group or a substituted amide group, or Q and Q represent the necessary atoms to close a heterocyclic ring having an electronegan've character e. g. a pyrazolone-S nucleus, In that respect are particularly mentioned the following groups in the meaning of X:

Groups of that type are generally known from merocyanine dye chemistry and can be introduced in a carbonyl group containing compound e.g. according to a preparation technique described in the UK. Pat. Specification No. 869,138 filed July 11, 1957 by Gevaert Photo-Producten NV. and are examplified as suitable substituents in photoconductive compounds in the US. Pat. No. 3,041,165 of Oskar Siis, Kurt-Walter Kliipfel, Wilhelm Neugebauer, Martha Tomanek and Hans Behmenburg issued June 26, 1962. The following examples lllustrate the present invention.

EXAMPLE ll To a polyethylene terephthalate support of p. a conductive transparent coating was applied from an aqueous solution of gelatin and CALGON CONDUCI'IVE POLYMER 261 (trade name) in a weight ratio of 2:1. Coating was carried out in such a way that the dried coating contained 2 g of gelatin per sq. m. The electrical resistivity of the coating was l X 10 ohms per sq. cm.

An electrophotographic recording material was prepared by coating onto said conductive layer a solution containing:

Cop01y(vinyl chloride/vinyl acetate/maleic anhydride)(mol 5 g.

ratio: 86.5/13.3/0.2). Methylene chloride 100ml.

The solution was applied in such a ratio that the dried recording layer contained 3 g per sq. m. of said quinolin-Z-one compound as photoconductor.

After a negative corona charging with a potential difi'erence of 6,000 V between the corona wires and the ground, the charged recording layer was contact-exposed for 5 sec. through a positive transparency of a test chart with incandescent bulbs that together represent 100 watts and were placed at a distance of 30 cm.

After exposure the development was carried out with a triboelectrically charged positive toner on the base of three parts by weight of pitch, four parts by weight of colophony and three parts by weight of carbon black.

A contrasty transparent positive copy of the transparency was obtained.

Analogous results as obtained with said quinolin-Z-one compound were obtained with same amounts of heterocyclic organic photoconductive substances having the following structural formulae tautomeric structure of C O 0 CZH5 tautomer'lc structure of 0n applying a positive corona charging with a potential difference of +6,000 V between the corona wires and the ground the exposure time lasted only 3 sec. to obtain a good image with the developer described in Example 4 hereinafter.

EXAMPLE 2 To an aluminum laminated paper a solution containing:

l-ethyl-3-phenyl-7-diethylamino-2-( l H)- quinolone 7.5 g. 1,2-dichloroethane 100 ml. copoly(vinyl chloride/vinyl acetate/maleic anhydride) (mol ratio 86.5/13.3/0.2) 5 g.

l-ethyl-3-phenyl-7-diethylarnino-2-( 1H) quinolone 7.5 g. Rhodamine B (C.l. Basic Violet Cl.

The dried recording layer contained also 2.5 g of l-ethyl-3- phenyl-7-diethylamino-2-( 1H )quinolone per sq. m.

Each of the coated samples (A) and (B) was negatively charged with a negative corona having a potential difl'erence of 6,000 V between the corona wires and the ground.

The sample (A) was contact-exposed for sec. at a distance of 25 cm through a step wedge having 0.30 log exposure increments by means of an OSRAM L 40 watt A 70 fluorescent tube having an emission maximum at 365 nm.

The sample (B) was contact-exposed for a same period of time at a distance of 25 cm through a step wedge having 0.30 log exposure increments by means of a tungsten filament lamp exposing the recording layer with 2,400 lux and having a color temperature of 2,600 K.

The latent wedge images were electrophoretically developed and contrasty copies were obtained. The electrophoretic developer used in the development was obtained by diluting the concentrated developer composition described hereinafter in a volume ratio of l5/ 1 ,000 by means of ISOPAR l-I (trade name for an isoparafiinic hydrocarbon mixture having a boiling range of l77l 88 C sold by Esso Belgium, N.V., Antwerp, Belgium):

carbon black (average particle size nm) 30 g. zinc monotridecyl phosphate as dispersing agent l.5 g. *lSOPAR H (trade name) 750 ml. resin solution prepared as described hereinafter 150 g.

EXAMPLE 3 To a glassine paper of 60 g per sq. m. the following solution was applied:

l-ethyl-3-phenyl-7-diethylamino-2( 1H)- quinolone 7.5 g.

FORMVAR 1595 E (a trade name for a polyvinylformal marketed by Shawinigan Resins Corporation, Springfield Mass, U.S.A.) 5 g.

As spectral sensitizing agent: Orange Astrazon R (0.1. Basic Orange 22; C.l. 48,040) having 0.020 g.

the following structural formula:

l a N 7 ll 01- I CCH=CH -CCH Acetone 75 ml.

The solution was applied at such a rate that the dried recording layer contained 2 g of l-ethyl-3-phenyl-7- diethylamino-2(lH)-quinolone per sq. m.

After a negative corona charging with a potential difierence of 6,000 V between the corona wires and the ground, the charged recording layer was contact-exposed for 3 see. through a positive transparency of a test chart with incandescent bulbs that together represent watts and were placed at a distance of 30 cm.

After the exposure the development was carried out with a triboelectrically charged positive toner on the base of three parts by weight of pitch, four parts by weight of colophony and three parts by weight of carbon black.

A constrasty positive copy of the transparency was obtained.

On adapting the exposure intensity analogous results were obtained with each of the compounds exemplified in the Tables I, II and Ill.

EXAMPLE 4 Example 3 was repeated with the diflerence, however, that the recording layer was positively corona-charged with a corona potential difference of +6,000 V between the corona wires and the ground.

The positively charged recording layer was exposed for 1 sec. through a test chart by means of tungsten filament lamps irradiating the recording layer with 1,400 lux.

The positive charge image on the exposed recording layer was electrophoretically developed with a developer obtained by diluting the concentrated developer composition described hereinafter in a volume ratio of 15/ l ,000 by means of SHELL- SOL T (trade name for a hydrocarbon solvent marketed by Shell, Belgium, having a boiling range of 175-200 C, specific gravity at 15 C: 0.764, viscosity at 25 C: 1.62 centipoise, flash point (Pensky-Martens) open cup: 71 C closed cup: 53 C) Kauri-butanol number: 31 ASTM norm D 1,133 54 carbon black (average particle size 20 nm) 30 g. lecithine 1.5 g. SHELLSOL T (trade name) 750 m1.

resin solution prepared as described hereinafter g.

The resin binder solution was prepared by heating at 60 C 500 g of ALKYDAL L 67 (trade name of Farbenfabriken Bayer A.G., Leverkusen, W. Germany for a linseed oilmodified (67 percent by weight alkyd resin)) and 500 cc. of white spirit containing 1 1 percent by weight of aromatic compounds till a clear solution was obtained, and subsequent cooling.

An image with high detail reproduction was obtained.

EXAMPLE 5 A solution of 4 g of l-ethyl-3-phenyl-7dimethylamino-2- (lH)-quinolone and 5 g of copoly( vinyl chloride/vinyl acetate/maleic anhydride)(mole ratio 865/] 3.3/0.2) in a mixture of 50 ml of methylene chloride and 50 ml of acetone was prepared. A sample of this unsensitized photoconductor composition was coated at a ran'o of 2 g of photoconductor per sq. m. on a sheet of aluminum foil laminated to a paper support.

Other samples of the unsensitized coating composition were sensitized by addition of 0.05 g of the sensitizing compounds mentioned in Table V and coated in the same way asthe unsensitized sample.

Each of the coated samples was negatively charged with a negative corona having a potential ditference of 6,000 V between the corona wires and the ground and then exposed for 15 sec. with 2,000 lux emitted by means of an incandescent lamp placed at a distance of 25 cm through a step wedge having 0.20 log exposure increments between consecutive steps.

The latent wedge images were electrophoretically developed by means of an electrophoretic developer obtained by diluting the concentrated developer composition described hereinafter in a volume ratio of 15/ 1,000 by means of the hydrocarbon solvent SHELLSOL T (trade name):

carbon black (average particle size 20 mu) 30 g. zinc monotridecyl phosphate 1.5 g. SHELLSOL T (trade name) 750 ml. resin solution prepared as described hereinafter 150 g.

The resin binder solution was prepared by heating 500 g of ALKYDAL L 67 (trade name of Farbenfabriken Bayer A.G., Leverkusen, W. Germany for a linseed oil (67 percent by weight)modified alkyd resin) and 500 ml of white spirit containing ll percent by weight of aromatic compounds at 60 C till a clear solution was obtained, and subsequent cooling.

Relative speed values of the developed samples were calculated based on a comparison of the number of visible steps in the wedge images obtained in the sensitized photoconductor materials with the number of visible steps produced in an unsensitized coating, given a relative speed of 100. The visible steps are the area of the wedge image that correspond with the discharge area on exposure.

The following Table V lists the relative speed values for these coatings.

TABLE V Sensitizing compound Relative speed number 7 none 100 l 1700 2 250 3 160 4 250 5 1700 6 160 7 160 8 160 9 160 10 250 11 250 12 4200 13 1000 14 4200 +N\ g I O1 CCH=CH J CHa CH3 S S \C-CH=CHCH=C/ i ll Br OCH; S S e CH 8 \?=CHE=C/ \O--CH= CH=C/S a O N 0= L .L .l

( 1 Hz-CH=CH zHs O O CH2 I omsor CH= CH= M N HO O C I 5 c1- Y H502 /CgH5 N- it v 0 H 0: 2 5

CzHs

S Se

IL N

m-Q-coon 11. CzH

s mo 0 I c-oH=o-cH=o Hz 0H;

CzHz.

CH= CH=C O; I l

E OCH; H300 N l N I \\C C/ IL CH CH g EXAMPLE 6 1-ethyl-3-phenyl-7-diethylamino-2-( 1H)- quinolone 7.5 g. copoly(vinyl chloride/vinyl acetate/maleie anhydride)(mol ratio: 86.5/l3.3/0.2) 5 g.

photoconductive zinc oxide powder prepared by oxidation of zinc vapour 4 g. acetone 100 ml.

of organic photoconductor per sq. m.

After a negative corona charging with a potential difference of 6,000 V between the corona wires and the ground, the recording layer was contact exposed for 5 sec. through a transparent test chart original with a high pressure mercury vapor lamp of 80 watts mainly emitting in the ultraviolet wavelength range of the spectrum and being placed at a distance of 25 cm of the recording layer.

The electrophoretic development was carried out as described in Example 5.

A sharp and contrasty semitransparent copy of the original was obtained.

EXAMPLE 7 To an aluminum-laminated paper a solution was applied containing:

l-ethyl-3-phenyl-7-diethylamino-quinoline-Z- The coating proceeded in such a way that the dried recording layer contained 2.5 g of photoconductive compound per The obtained recording material was negatively coronacharged with a corona-charging apparatus having a potential difference of -6,000 V between the corona wires and the ground. Thereupon it was contact-exposed for 45 sec. at a distance of 30 cm through a step wedge having 0.20 log exposure increments using 5 OSRAM L 20 WHO fluorescent tubes mainly emitting in the UV. range and the shorter wavelengths of the visible spectrum (OSRAM is a trade name).

After the exposure the development was carried out as described in Example 2.

A contrasty opaque positive copy of the step wedge was obtained.

EXAMPLE 8 Example 7 was repeated by using, however, as binding agent MOWlLITl-l 20 (trade name for a polyvinyl acetate marketed by Farbwerke Hoechst A.G., Frankfurt (M) Hochst, W. Germany). The same amounts of polymer and solvent were applied as in Example 7, the solvent, however, now being acetone.

Exposure and processing as described in Example 7 yielded the same image result.

EXAMPLE 9 To a polyethylene terephthalate support of 100 p. a conductive transparent coating was applied from an aqueous solution of gelatin and CALGON CONDUCTIVE POLYMER 261 (trade name) in a weight ratio of 2:1. The coating was carried out in such a way that the dried coating contained 2 g of gelatin per sq. m. The electrical resistivity of the coating was 1 X 10 ohms per sq. cm.

An electrophotographic recording material was prepared by coating onto said conductive layer a solution containing:

CzHs

As chemical sensitizing agent:

Copoly viny1 cholride/vinyl acetate/maleic anhydride) (mol 5g.

ratio: 86.5/l3.3/0.2). Methylenechloride ml.

The solution was applied in such a ratio that the dried recording layer contained 2 g per sq. m of said quinoline2- one compound as photoconductor.

After a negative corona charging with a potential difference of 6,000 V between the corona wires and the ground, the charged recording layer was contact-exposed for 7 sec. through a positive transparency of a test chart with incandescent bulbs that together represent l00 watts and were placed at a distance of 30 cm.

After the exposure the development was carried out as described in Example 2.

A contrasty transparent positive copy of the original was obtained.

EXAMPLE 10 A solution of 5 g of l-ethyl-3-phenyl-7-diethylamino-2- (lH)-quinolone and 5 g of copoly(vinylchloride/vinylace tate/maleic anhydride) (mole ratio 86.5/l3.3/0.2) in a mixture of 100 ml of methylene chloride was prepared.

A sample of this unsensitized photoconductor composition was coated in a ratio of 2 g of photoconductor per sq. m on a sheet of aluminum foil laminated to a paper support.

Other samples of the unsensitized coating composition were sensitized by addition of 0.2 g of the sensitizing compounds mentioned in Table VI and coated in the same way as the unsensitized sample.

Each of the coated samples was negatively charged with a negative corona having a potential difference of 6,000 V between the corona wires and the ground and then exposed for 30 see. with 1,400 lux emitted by means of an incandescent lamp placed at a distance of 25 cm through a step wedge having 0.20 log exposure increments between consecutive steps.

The latent wedge images were electrophoretically developed by means of the electrophoretic developer described in Example 5.

Relative speed values of the developed samples were calculated based on a comparison of the number of visible steps in the wedge images obtained in the sensitized photoconductor materials with the number of visible steps produced in an unsensitized coating, given a relative speed of 100. The visible steps are the area of the wedge image that correspond with the discharged area on exposure.

The following Table VI lists the relative speed values for these coatings.

Claims (35)

1. 2. A recording process according to claim 1, wherein a pattern of increased conductivity is produced image-wise in a photoconductive insulating recording element comprising a photoconductive quinoline compound carrying an oxygen atom in the two-position.
2. 2. exposing the recording layer to activating electromagnetic radiation creating an electrostatic charge pattern corresponding with the phosphor pattern to be formed,
3. 3. developing the electrostatic charge pattern by means of phosphor particles, and
4. 3. A recording process according to claim 1, wherein a pattern of increased conductivity is produced image-wise in a photoconductive insulating recording element comprising a photoconductive quinoline compound carrying a sulphur atom in the two-position.
5. 4. A recording process, according to claim 1, wherein a pattern of increased conductivity is produced image-wise in a photoconductive insulating recording element comprising a photoconductive quinoline compound carrying a group in the two-position.
6. 4. removing the photoconductive compound and optionally present binding agent by heating the support.
7. 5. A recording process according to claim 1, wherein a pattern of increased conductivity is produced image-wise in a photoconductive insulating recording element comprising a photoconductive quinoline compound carrying in the two-position an imino group substituted with a phenyl group.
8. 6. A recording process according to claim 1, wherein a pattern of increased conductivity is produced image-wise in a photoconductive insulating recording element comprising a photoconductive quinoline compound carrying in the two-position an oxime group.
9. 7. A recording process according to claim 1, wherein a pattern of increased conductivity is produced image-wise in a photoconductive insulating recording element comprising a photoconductive quinoline compound carrying in the two-position a hydrazone group.
10. 8. A recording process according to claim 1, wherein a pattern of increased conductivity is produced image-wise in a photoconductive insulating recording element comprising a photoconductive quinoline compound carrying an oxygen atom in the four-position.
11. 9. A recording process according to claim 1, wherein a pattern of increased conductivity is produced image-wise in a photoconductive insulating recording element comprising a photoconductive quinoline compound carrying a sulphur atom in the four-position.
12. 10. A recording process, according to claim 1, wherein a pattern of increased conductivity is produced image-wise in a photoconductive insulating recording element comprising a photoconductive quinoline compound carrying in the four-position a group.
13. 11. A recording process according to claim 1, wherein a pattern of increased conductivity is produced image-wise in a photoconductive insulating recording element comprising a photoconductive quinoline compound carrying in the four-position an imino group substituted with a phenyl group.
14. 12. A recording process according to claim 1, wherein a pattern of increased conductivity is produced image-wise in a photoconductive insulating recording element comprising a photoconductive quinoline compound carrying in the four-position an oxime group.
15. 13. A recording process according to claim 1, wherein a pattern of increased conductivity is produced image-wise in a photoconductive insulating recording element comprising a photoconductive quinoline compound carrying in the four-position a hydrazone group.
16. 14. A method for recording information according to claim 1, comprising the steps of electrostatically charging and information-wise exposing the recording element to electromagnetic radiation, thereby increasing the conductivity of the radiation struck areas and carrying off the electrostatic charge in said areas, and developing the resulting electrostatic Pg,77 charge pattern by means of an electrostatically attractable material.
17. 15. A recording material comprising a photoconductive insulating recording element capable of being electrostatically charged in the absence of activating electromagnetic radiation and capable of retaining the applied charge for a period of time long enough to produce thereon a developed electrostatic charge pattern, carried on a layer or support of lower resistivity and characterized in that said recording element contains at least 10 percent by weight of a photoconductive compound corresponding to one of the following general formula:
18. 16. A recording material according to claim 15, wherein said layer or support has a resistivity at least 102 as low as that of the recording element itself.
19. 17. A recording material according to claim 15, wherein the support is a paper support.
20. 18. A recording material according to claim 15, wherein the support is an insulating transparent resin support coated with a transparent electroconductive interlayer.
21. 19. A recording material according to claim 15, wherein said binder is a polymer.
22. 20. A recording material according to claim 19, wherein said binder is a halogen-containing polymer.
23. 21. A recording material according to claim 20, wherein the halogen-containing polymer contains vinyl chloride units.
24. 22. A recording material according to claim 15, wherein the photoconductive compound is used in admixture with a spectral sensitizing agent increasing the photosensitivity of the recording element.
25. 23. A recording material according to claim 15, wherein the photoconductive compound is used in admixture with a spectral sensitizing dye.
26. 24. A recording material according to claim 15, wherein the photoconductive compound is used in admixture with a photoconductive compound selected from the group of photoconductive selenium, and the photoconductive oxides, sulphides, and selenides of zinc, cadmium, mercury, antimony, bismuth and lead.
27. 25. A recording material according to claim 15, wherein the photoconductive recording element has an optical density not higher than 0.30 for substantially visible light.
28. 26. A recording material according to claim 23, wherein the said dye is a triarylmethane dye, xanthene dye or a methine dye.
29. 27. A recording material according to claim 15, wherein the recording element contains 7-dialkylamino-quinoline-2-one compound.
30. 28. A recording material according to claim 15, wherein the photoconductive compound is 1-ethyl-3-phenyl-7-diethylamino-2-(1H)-quinolone or 1-ethyl-3-phenyl-7-dimethylamino-2(1H)-quinolone.
31. 29. A recording material according to claim 15 suitable for use in an electrophotographic process, and wherein the recording element is a solid layer having a dark-resistivity of at least 108 ohm/cm.
32. 30. In an improved process for the production of a phosphor pattern on a cathode-ray tube screen the improvement wherein said phosphor pattern contains a photoconductive compound corresponding to one of the following general formula:
33. 31. A process according to claim 30, wherein the phosphor pattern before heating is fixed with a thermolyzable polymer layer or coating.
34. 32. A process according to claim 31, wherein the polymer forming said layer or coating is a polyacrylic aCid ester or polymethacrylic acid ester.
35. 33. The process of claim 1 wherein said photoconductive compound is 1-ethyl-3-phenyl-7-diethylamino-2(1H)-quinolone or 1-ethyl-3-phenyl-7-dimethylamino-2(1H)-quinolone.