Migration imaging process and compositions

Materials having the following structure ##STR1## have been found useful in migration imaging processes.

FIELD OF THE INVENTION 
This invention relates to electrophoretic migration imaging processes and, 
in particular, to the use of certain photosensitive pigment materials in 
such processes. 
BACKGROUND OF THE INVENTION 
In the past, there has been extensive description in the patent and other 
technical literature of electrophoretic migration imaging processes. For 
example, a description of such processes may be found in U.S. Pat. Nos. 
2,758,939 by Sugarman issued Aug. 14, 1956; 2,940,847, 3,100,426, 
3,140,175 and 3,143,508, all by Kaprelian; 3,384,565, 3,384,488 and 
3,615,558, all by Tulagin et al.; 3,384,566 by Clark; and 3,383,933 by 
Yeh. In addition to the foregoing patent literature directed to 
conventional photoelectrophoretic migration imaging processes, another 
type of electophoretic migration imaging process which advantageously 
provides for image reversal is described in Groner, U.S. Pat. No. 
3,976,485 issued Aug. 24, 1976. This latter process has been termed 
photoimmobilized electrophoretic recording or PIER. 
In general, each of the foregoing electrophoretic migration imaging 
processes typically employs a layer of electrostatic charge-bearing 
photoconductive particles, i.e., electrically photosensitive particles, 
positioned between two spaced electrodes, one of which may be transparent. 
To achieve image formation in these processes, the charge-bearing 
photosenstitive particles positioned between the two spaced electrodes, as 
described above, are subjected to the influence of an electric field and 
exposed to activating radiation. As a result, the charge-bearing 
electrically photosensitive particles are caused to migrate 
electrophoretically to the surface of one or the other of the spaced 
electrodes, and one obtains an image pattern on the surface of these 
electrodes. Typically, a negative image is formed on one electrode, and a 
positive image is formed on the opposite electrode. Image discrimination 
occurs in the various electrophoretic migration imaging processes as a 
result of a net change in charge polarity of either the exposed 
electrically photosensitive particles (in the case of conventional 
electrophoretic migration imaging) or the unexposed electrically 
photosensitive particles (in the case of the electrophoretic migration 
imaging process described in the above-noted Groner patent application) so 
that the image formed on one electrode surface is composed ideally of 
electrically photosensitive particles of one charge polarity, either 
negative or positive polarity, and the image formed on the opposite 
polarity electrode surface is composed ideally of electrically 
photosensitive particles having the opposite charge polarity, either 
positive or negative respectively. 
In any case, regardless of the particular electrophoretic migration imaging 
process employed, it is apparent that an essential component of any such 
process is the electrically photosensitive particles. And, of course, to 
obtain an easy-to-read, visible image it is important that these 
electrically photosensitive particles be colored, as well as electrically 
photosensitive. Accordingly, as is apparent from the technical literature 
regarding electrophoretic migration imaging processes, work has been 
carried on in the past and is continuing to find particles which possess 
both useful levels of electrical photosensitivity and which exhibit good 
colorant properties. Thus, for example, various types of electrically 
photosensitive materials are disclosed for use in electrophoretic 
migration imaging processes, for example, in U.S. Pat. Nos. 2,758,939 by 
Sugarman, 2,940,847 by Kaprelian, and 3,384,488 and 3,615,558 by Tulagin 
et al., noted hereinabove. 
In large part, the art, to date, has generally selected useful electrically 
photosensitive or photoconductive pigment materials for electrophoretic 
migration imaging from known classes of photoconductive materials which 
may be employed in conventional photoconductive elements, e.g., 
photoconductive plates, drums, or webs used in electrophotographic 
office-copier devices. For example, both Sugarman and Kaprelian in the 
above-referenced patents state that electrically photosensitive materials 
useful in electrophoretic migration imaging processes may be selected from 
known classes of photoconductive materials. Also, the phthalocyanine 
pigments described as a useful electrically photosensitive material for 
electrophoretic imaging processes in U.S. Pat. No. 3,615,558 by Tulagin et 
al. have long been known to exhibit useful photoconductive properties. 
SUMMARY OF THE INVENTION 
In accord with the present invention, a group of materials has been 
discovered which are useful in electrophoretic migration imaging 
processes. To the best of our knowledge, none of said materials have been 
previously identified as photoconductors. Said materials have the 
following structure: 
##STR2## 
wherein G.sup.1 and G.sup.2, which may be the same or different, represent 
(1) an electron withdrawing group such as cyano, acyl, alkoxycarbonyl, 
nitroaryl, alkylsulfonyl, arylsulfonyl, fluorosulfonyl, and nitro, or 
(2) when taken together with carbon atom to which they are attached G.sup.1 
and G.sup.2 represent the non-metallic atoms needed to complete a 
substituted or unsubstituted acidic cyclic nucleus of the type used in 
merocyanine dyes such as 1,3-inandione; 1,3-cyclohexanedione; 
5,5-dimethyl-1,3-cyclohexanedione; and 1,3-dioxan-4,6-dione; etc., or 
(3) an acidic heterocyclic nucleus containing from 5 to 6 atoms in the 
heterocyclic ring, such as 
(a) a pyrazolinone nucleus such as 3-methyl-1-phenyl-2-pyrazolin-5-one, 
1-phenyl-2-pyrazolin-5-one and 
1-(2-benzothiazolyl)-3-methyl-2-pyrazolin-5-one, 
(b) an isoxazolinone nucleus such as 3-phenyl-2-isoxazolin-5-one and 
3-methyl-2-isoxazolin-5-one; 
(c) an oxindole nucleus such as 1-alkyl-2,3-dihydro-2-oxindoles; 
(d) a 2,4,6-triketohexahydropyrimidine nucleus such as barbituric acid or 
2-thiobarbituric acid, as well as their derivatives such as those with 
1-alkyl(e.g., 1-methyl, 1-ethyl, 1-n-propyl, 1-n-heptyl, etc.) or 
1,3-dialkyl (e.g., 1,3-dimethyl, 1,3-diethyl, 1,3-di-n-propyl, 
1,3-diisopropyl, 1,3-dicyclohexyl, 1,3-di(.beta.-methoxyethyl), etc.) or 
1,3-diaryl (e.g., 1,3-diphenyl, 1,3-di(p-chlorophenyl), 
1,3-di(p-ethoxycarbonylphenyl), etc.), or 1-aryl (e.g., 1-phenyl, 
1-p-chlorophenyl, 1-p-ethoxycarbonylphenyl), etc.), or 1-alkyl-3-aryl 
(e.g., 1-ethyl-3-phenyl, 1-n-heptyl-3-phenyl, etc.); 
(e) a 2-thio-2,4-thiazolidinedione nucleus such as rhodanine, 
3-alkylrhodanines (e.g., 3-ethylrhodanine, 3-allylrhodanine, etc.), or 
3-arylrhodanines (e.g., 3-phenylrhodanine etc.); 
(f) a 2-thio-2,4-oxazolidinedione (2-thio-2,4(3H,5H)-oxazoledione) nucleus 
such as 3-ethyl-2-thio-2,4-oxazolidinedione; 
(g) a thianaphthenone nucleus such as 3(2H)-thianaphthenone and 
3(2H)-thianaphthenone-1,1-dioxide; 
(h) a 2-thio-2,5-thiazolidinedione (2-thio-2,5(3H,4H)-thiazoledione) 
nucleus such as 3-ethyl-2-thio-2,5-thiazolidinedione; 
(i) a 2,4-thiazolidinedione nucleus such as 2,4-thiazolidinedione, 
3-ethyl-2,4-thiazolidinedione, 3-phenyl-2,4-thiazolidinedione and 
3-.alpha.-naphthyl-2,4-thiazolidinedione; 
(j) a thiazolidinone nucleus such as 4-thiazolidinone, 
3-ethyl-4-thiazolidinone, 3-phenyl-4-thiazolidinone and 
3-.alpha.-naphthyl-4-thiazolidinone; 
(k) a 4-thiazolinone nucleus such as 2-ethylmercapto-5-thiazolin-4-one, 
2-alkylphenylamino-5-thiazolin-4-ones, 2-diphenylamino-5-thiazolin-4-one; 
(l) a 2-imino-2-oxazolin-4-one pseudohydantoin nucleus; 
(m) a 2,4-imidazolidinedione(hydantoin)nucleus such as 
2,4-imidazolidinedione, 3-ethyl-2,4-imidazolidinedione, 
3-phenyl-2,4-imidazolidinedione, 
3-.alpha.-naphthyl-2,4-imidazolidinedione, 1,3-diethyl-2,4-imidazolidinedi 
one, 1-ethyl-3-.alpha.-naphthyl-2,4-imidazolidinedione and 
1,3-diphenyl-2,4-imidazolidinedione; 
(n) a 2-thio-2,4-imidazolidinedione (2-thiohydantoin) nucleus such as 
2-thio-2,4-imidazolidinedione, 3-ethyl-2-thio-2,4-imidazolidionedione, 
3-phenyl-2-thio-2,4-imidazolidinedione, 
3-.alpha.-naphthyl-2-thio-2,4-imidazolidinedione, 
1,3-diethyl-2-thio-2,4-imidazolidinedione, 
1-ethyl-3-phenyl-2-thio-2,4-imidazolidinedione, 
1-ethyl-3-.alpha.-naphthyl-2-thio-2,4-imidazolidinedione and 
1,3-diphenyl-2-thio-2,4-imidazolidinedione; 
(o) a 2-imidazolin-5-one nucleus such as 
2-n-propylmercapto-2-imidazolin-5-one; 
(p) furan-5-one and 
(q) a heterocyclic nucleus containing 5 atoms in the heterocyclic ring, 3 
of said atoms being carbon atoms, 1 of said atoms being a nitrogen atom 
and 1 of said atoms being selected from the group consisting of a nitrogen 
atom, an oxygen atom, and a sulfur atom; 
X may be O, S, Se or NR in which R represents a substituted or 
unsubstituted alkyl, aryl, aralkyl, cycloalkyl, alkenyl or alkynyl and 
said substituents are selected from the group consisting of hydroxy, 
alkoxy; aryloxy or halogen; 
R.sup.1 and R.sup.2 which may be the same or different, represent alkyl, 
aryl, --CL.sup.1 (.dbd.CL.sup.2 --CL.sup.3).sub.m .dbd.A.sup.1, --CL.sup.4 
.dbd.CL.sup.5 (--CL.sup.6 .dbd.CL.sup.7).sub.n --A.sup.2 or R.sup.1 
together with R.sup.4 or R.sup.2 together with R.sup.3 represent 
sufficient atoms to complete an alkylene bridge; 
m and n may be zero, one or two; 
L.sup.1, L.sup.2, L.sup.3, L.sup.4, L.sup.5, L.sup.6, and L.sup.7 represent 
hydrogen, alkyl and aryl; L.sup.1 or L.sup.4 together with either R.sup.3 
or R.sup.4 represent the atoms needed to complete a carbocyclic ring; 
A.sup.1 represents a basic substituted or unsubstituted heterocyclic 
nucleus of the type used in cyanine dyes such as, 
(a) an imidazole nucleus, 4-phenylimidazole; 
(b) 3H-indole nucleus such as 3H-indole, 3,3-dimethyl-3H-indole, 
3,3,5-trimethyl-3H-indole; 
(c) a thiazole nucleus such as thiazole, 4-methylthiazole, 
4-phenylthiazole, 5-methylthiazole, 5-phenylthiazole, 
4,5-dimethylthiazole, 4,5-diphenylthiazole, 4-(2-thienyl)thiazole; 
(d) a benzothiazole nucleus such as benzothiazole, 4-chlorobenzothiazole, 
5-chlorobenzothiazole, 6-chlorobenzothiazole, 7-chlorobenzothiazole, 
4-methylbenzothiazole, 5-methylbenzothiazole, 6-methylbenzothiazole, 
5-bromobenzothiazole, 6-bromobenzothiazole, 4-phenylbenzothiazole, 
5-phenylbenzothiazole, 4-methoxybenzothiazole, 5-methoxybenzothiazole, 
6-methoxybenzothiazole, 5-iodobenzothiazole, 6-iodobenzothiazole, 
4-ethoxybenzothiazole, 5-ethoxybenzothiazole, tetrahydrobenzothiazole, 
5,6-dimethyoxybenzothiazole, 5,6-dioxymethylenebenzothiazole, 
5-hydroxybenzothiazole and 6-hydroxybenzothiazole; 
(e) a naphthothiazole nucleus such as 
naphtho1,2-d!thiazole,naphtho2,1-d!thiazole, naphtho2,3-d!thiazole, 
5-methoxynaphtho2,1-d!thiazole, 5-ethoxynaphtho2,1-d!thiazole, 
8-methoxynaphtho1,2-d!thiazole and 7-methoxynaphtho1,2-d!thiazole; 
(f) a thianaphtheno-7',6',4,5-thiazole nucleus such as 
4'-methoxythianaphtheno-7',6',4,5-thiazole; 
(g) an oxazole nucleus such as 4-methyloxazole, 5-methyloxazole, 
4-phenyloxazole, 4,5-diphenyloxazole, 4-ethyloxazole, 4,5-dimethyloxazole 
and 5-phenyloxazole; 
(h) a benzoxazole nucleus such as benzoxazole, 5-chlorobenzoxazole, 
5-methylbenzoxazole, 5-phenylbenzoxazole, 6-methylbenzoxazole 
5,6-dimethylbenzoxazole, 4,6-dimethylbenzoxazole, 5-methoxybenzoxazole, 
5-ethoxybenzoxazole, 5-chlorobenzoxazole, 6-methoxybenzoxazole, 
5-hydroxybenzoxazole and 6-hydroxybenzoxazole; 
(i) a naphthoxazole nucleus such as naphtho1,2!oxazole and 
naphtho2,1!oxazole; 
(j) a selenazole nucleus such as 4-methylselenazole and 4-phenylselenazole; 
(k) a benzoselenazole nucleus such as benzoselenazole, 
5-chlorobenzoselenazole, 5-methoxybenzoselenazole, 
5-hydroxybenzoselenazole and tetrahydrobenzoselenazole; 
(l) a naphthoselenazole nucleus such as naphtho1,2-d!selenazole, 
naphtho2,1-d!selenazole; 
(m) a thiazoline nucleus such as thiazoline and 4-methylthiazoline; 
(n) a 2-quinoline nucleus such as quinoline, 3-methylquinoline, 
5-methylquinoline, 7-methylquinoline, 8-methylquinoline, 
6-chloroquinoline, 8-chloroquinoline, 6-methoxyquinoline, 
6-ethoxyquinoline, 6-hydroxyquinoline and 8-hydroxyquinoline; 
(o) a 4-quinoline nucleus such as quinoline, 6-methoxyquinoline, 
7-methylquinoline and 8-methylquinoline; 
(p) a 1-isoquinoline nucleus such as isoquinoline and 
3,4-dihydroisoquinoline; 
(q) a benzimidazole nucleus such as 1,3-diethylbenzimidazole and 
1-ethyl-3-phenylbenzimidazole; 
(r) a 2-pyridine nucleus such as pyridine and 5-methylpyridine; and 
(s) a 4-pyridine nucleus; 
A.sup.2 may be the same as A.sup.1 and in addition may represent a 
substituted or unsubstituted aryl group (e.g., phenyl, naphthyl, anthryl) 
or a substituted or unsubstituted heterocyclic nucleus such as thiophene, 
benzob!thiophene, naphtho2,3-b!thiophene, furan, isobenzofuran, 
chromene, pyran, xanthene, pyrrole, 2H-pyrrole, pyrazole, indolizine, 
indoline, indole, 3H-indole, indazole, carbazole, pyrimidine, isothiazole, 
isoxazole, furazan, chroman, isochroman, 1,2,3,4-tetrahydroquinoline, 
4H-pyrrolo 3,2,1-ij!quinoline, 1,2-dihydro-4H-pyrrolo3,2,1-ij!quinoline; 
1,2,5,6-tetrahydro-4H-pyrrolo-3,2,1-ij!quinoline; 
1H,5H-benzoij!quinolizine; 2,3-dihydro-1H,5H-benzoij!quinolizine; 
2,3-dihydro-1H,5H-benzoij!quinolizine and 
2,3,6,7-tetrahydro-1H,5H-benzoij!quinolizine, 
10,11-dihydro-9H-benzoa!xanthen-8-yl; 6,7-dihydro-5H-benzob!pyran-7-yl; 
R.sub.3 represents hydrogen or R.sub.3 together with R.sup.2, L.sup.1 or 
L.sup.4 and the carbon atoms to which they are attached represent a 5 or 6 
membered carbocyclic ring; 
R.sub.4 may be the same as R.sub.3 when taken alone or together with 
R.sup.1, L.sup.1 or L.sup.4 ; except that 
(A) R.sup.1 and R.sup.2 cannot both be methyl, phenyl or methyl and phenyl, 
and 
(B) the substituents on A.sup.1 and A.sup.2 cannot result in a quaternary 
nitrogen. 
As indicated hereinabove, G.sup.1 and G.sup.2 when taken together may 
contain a variety of different substituents such as alkyl, aryl, aralkyl, 
cycloalkyl, alkenyl, alkynyl, dialkylamino, diarylamino or diaralkylamino 
which may be further substituted by one or more hydroxy, alkoxy, or 
aryloxy groups or halogens, or various acid substituted alkyl or aryl 
groups such as carboxymethyl, 5-carboxypentyl, 2-sulfoethyl, 
3-sulfatopropyl, 3-thiosulfatopropyl, 2-phosphonoethyl, 3-sulfobutyl, 
4-sulfobutyl, 4-carboxyphenyl, 4-sulfophenyl, etc. A.sup.1 and A.sup.2 may 
contain a variety of different substituents including those listed above 
as possible substituents on nuclei represented by G.sup.1 and G.sup.2 
taken together plus amino, alkylamino, arylamino, aralkylamino, alkoxy, 
aryloxy, and alkoxycarbonyl. 
Unless stated otherwise, alkyl refers to aliphatic hydrocarbon groups of 
generally 1-20 carbon atoms such as methyl, ethyl, propyl, isopropyl, 
butyl, heptyl, dodecyl, octadecyl, etc.; aryl refers to aromatic ring 
groups of generally 6-20 carbon atoms such as phenyl, naphthyl, anthryl or 
to alkyl or aryl substituted aryl groups such as tolyl, ethylphenyl, 
biphenylyl, etc.; aralkyl refers to aryl substituted alkyl groups such as 
benzyl, phenethyl, etc.; cycloalkyl refers to saturated carbocyclic ring 
groups which may have alkyl, aryl or aralkyl substituents such as 
cyclopropyl, cyclopentyl, cyclohexyl, 5,5-dimethylcyclohexyl, etc.; alkoxy 
refers to alkyloxy groups where alkyl is as defined above, such as 
methoxy, ethoxy, isopropoxy, butoxy, etc.; aryloxy refers to analogous 
groups where aryl is as defined above, such as phenoxy, naphthoxy, etc.; 
acyl refers to alkyl, aryl, or aralkylcarbonyl groups such as acetyl, 
propionyl, butyryl, benzoyl, phenylacetyl, etc.; alkenyl refers to an 
aliphatic hydrocarbon group of generally 1-20 carbons, which may be 
further substituted by alkyl or aryl, and which has at least one double 
bond such as allyl, vinyl, 2-butenyl, etc.; alkynyl refers to an aliphatic 
hydrocarbon group of generally 1-10 carbons which may be further 
substituted by alkyl or aryl and which has at least one triple bond such 
as 2-propynyl, 2-butynyl, 3-butynyl, etc.; alkylene refers to a bivalent 
aliphatic hydrocarbon group of generally 1-10 carbons such as ethylene, 
trimethylene, neopentylene, etc. 
When used in an electrophoretic migration imaging process, charge-bearing, 
electrically photosensitive particles formulated from the materials of the 
present invention are positioned between two spaced electrodes; preferably 
these particles are contained in an electrically insulating carrier such 
as an electrically insulating liquid or an electrically insulating, 
liquefiable matrix material, e.g., a thixotropic or a heat- and/or 
solvent-softenable material, which is positioned between the spaced 
electrodes. While so positioned between the spaced electrodes, the 
photosensitive particles are subjected to an electric field and exposed to 
a pattern of activating radiation. As a consequence, the charge-bearing, 
electrically photosensitive particles undergo a radiation-induced 
variation in their charge polarity and migrate to one or the other of the 
electrode surfaces to form on at least one of these electrodes an image 
pattern representing a positive-sense or negative-sense image of the 
original radiation exposure pattern.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In accordance with one embodiment the present invention there is provided a 
group of materials which are useful in electrophoretic migration imaging 
processes. Said materials have the structure according to general Formula 
I wherein: 
G.sup.1 and G.sup.2 represent cyano, acyl, alkoxycarbonyl, nitro aryl, 
alkylsulfonyl, arylsulfonyl, fluorosulfonyl, and nitro, or when taken 
together with the carbon atom to which they are attached, G.sup.1 and 
G.sup.2 represent the non-metallic atoms necessary to complete a 
substituted or unsubstituted nucleus selected from the group consisting of 
1,3-indane-dione, 1,3-cyclohexane-dione, 
5,5-dimethyl-1,3-cyclohexane-dione; 1,3-dioxane-4,6-dione, 
2-isoxazolin-5-one, barbituric acid, thiobarbituric acid and said 
substituents are selected from the group consisting of alkyl and aryl; 
R.sup.1 and R.sup.2 are as previously defined; 
A.sup.1 represents a substituted and unsubstituted nucleus selected from 
the group consisting of thiazole, thiazolidine, benzothiazole, 
naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, 2-quinoline, 
4-quinoline and 3H-indole; 
A.sup.2 represents a substituted or unsubstituted alkyl or aryl group or a 
nucleus selected from the group consisting of thiazole, benzothiazole, 
naphthol1,2-d!thiazole, benzoxazole, benzoselenazole, 2-quinoline and 
3,3-dimethylindolenine, thiophene, furan, pyran, pyrrole, pyrazole, 
indoline, indole, carbazole, 1,2,3,4-tetrahydroquinoline, and 
2,3,7-tetrahydro-1H,5H-benzoij!quinolizine. 
R.sup.3 represents hydrogen or together with R.sup.2, L.sup.1 or L.sup.4, 
and the carbon atoms to which they are attached, represent substituted or 
unsubstituted cyclopentene or cyclohexene and R.sup.4 is the same as 
R.sup.3 when taken alone or together with R.sup.1, L.sup.1 or L.sup.4 and 
said substituents are selected from the group consisting of alkyl or the 
halogens; 
Said substituents G.sup.1 and G.sup.2 when taken together are selected from 
the group consisting of alkyl of 1-4 carbons, aryl of 1-14 carbons, 
aralkyl, cycloalkyl of 3-8 carbons, alkenyl, alkynyl, dialkylamino, 
diarylamino, or diaralkylamino which may be further substituted by 
hydroxy, alkoxy, or halogens or various acid substituted alkyl or aryl 
group such as carboxymethyl, 5-carboxypentyl, 2-sulfoethyl, 
3-sulfatopropyl, 3-thiosulfatopropyl, 2-phosphonoethyl, 3-sulfobutyl, 
4-sulfobutyl, 4-carboxyphenyl and 4-sulfophenyl; said substituents for 
A.sup.1 and A.sup.2 may be selected from a variety of different 
substituents including those listed above as substituents on nuclei 
represented by G.sup.1 and G.sup.2 taken together plus amino, alkylamino, 
arylamino, aralkylamino, alkoxy, aryloxy, and alkoxycarbonyl. 
R.sup.3 represents hydrogen or together with R.sup.2, L.sup.1 or L.sup.4 
and the carbon atoms to which they are attached, represent substituted or 
unsubstituted cyclopentene or substituted or unsubstituted cyclohexene and 
R.sup.4 is the same as R.sup.3 when taken alone or together with R.sup.1, 
L.sup.1 or L.sup.4 and said substituents may be an alkyl group or halogen. 
In accordance with another embodiment of the present invention there is 
provided material within the scope of general Formula I which is useful in 
electrophoretic migration imaging processes such material having the 
following structure: 
##STR3## 
wherein: 
X represents O, S, and NR in which R is alkyl having 1-8 carbons, aryl 
having 6-14 carbons or aralkyl. 
R.sup.1 and R.sup.2 which may be the same or different, represent alkyl of 
1-4 carbon atoms, aryl of 6-14 carbon atoms, --CH(.dbd.CL.sup.2 
--CH).sub.m .dbd.A.sup.1 or --CH.dbd.CH--A.sup.2 wherein m is zero or one, 
L.sup.2 is hydrogen, alkyl of 1-4 carbon atoms, or aryl of 6-14 carbon 
atoms, A.sup.1 represents benzoxazole, benzothiazole, 
naphtho1,2-d!thiazole, 2-quinoline or 4-quinoline, and A.sup.2 represents 
furan, pyran, pyrrole, pyrazole, indoline, carbazole; 
1,2,3,4-tetrahydroquinoline; 
1,2,5,6-tetrahydro-4H-pyrrole3,2,1-ij!quinoline; 
2,3,6,7-tetrahydro-1H,5H-benzoij!quinolizine; 
10,11-dihydro-9H-benzoa!xanthen-8-yl; 6,7-dihydro-5H-benzob!pyran-7-yl; 
anthryl, alkoxy having 1-4 carbon atoms, aryl having one or more 
substituents selected from secondary amino groups such as dialkylamino, 
diarylamino, bis(alkoxycarbonyl)amino, diaralkylamino and pyrrolidino. 
In accordance with another embodiment of the present invention, there is 
provided materials within the scope of general Formula I which are useful 
in electrophoretic migration imaging processes, said materials having the 
following structure: 
##STR4## 
wherein 
R.sub.2 represents --CH(.dbd.CL.sup.2 --CH).sub.m .dbd.A.sup.1, 
CH.dbd.CH(--CH.dbd.CH).sub.n --A.sup.2, in which L.sup.2 represents 
hydrogen or phenyl; m and n represent 0 or 1; A.sup.1 and A.sup.2 
represent anthryl, naphthyl, aryl having one or more substituents selected 
from dialkylamino and alkoxy, pyran, 
1,2,5,6-tetrahydro-4H-pyrrolo3,2,1-i!-quinoline and 
2,3,6,7-tetrahydro-1H,5H-benzoij!quinoline. 
In accordance with yet another embodiment of the present invention there is 
provided materials within the scope of general Formula I which are useful 
in electrophoretic migration imaging processes. Such materials have the 
structure: 
##STR5## 
wherein 
R.sup.1 and R.sup.2 which may be the same or different, represent CL.sup.1 
.dbd.CH--CH.dbd.A.sup.1, CH.dbd.CL.sup.4 .dbd.CH--A.sup.2 or R.sup.1 taken 
together with R.sup.4 or R.sup.2 taken together with R.sup.3 may complete 
an unsubstituted cyclopentene or cyclohexene ring except that both R.sup.1 
and R.sup.4 and R.sup.2 and R.sup.3 cannot complete an unsubstituted 
cyclopentene or cyclohexene ring; L.sup.1 or L.sup.4 when taken together 
with R.sup.3 or R.sup.4 represent the atoms needed to form a cyclopentene 
or cyclohexene; A.sup.1 may represent benzoxazole and A.sup.2 may 
represent a dialkylaminophenyl or a 
2,3,6,7-tetrahydro-1H,5H-benzoij!quinolizine. 
In accordance with yet another embodiment of the present invention there is 
provided materials within the scope of general Formula I which are useful 
in electrophoretic migration imaging processes. Such materials have the 
formula: 
##STR6## 
wherein 
G.sup.1 and G.sup.2 taken together with the carbon atom to which they are 
attached represent the non-metallic atoms necessary to complete a 
substituted or unsubstituted nucleus selected from the group consisting of 
1,3-indanedione, 1,3-cyclohexanedione, 5,5-dimethyl-1,3-cyclohexanedione, 
1,3-dioxan-4,6-dione, 2-isoxazolin-5-one, 2-thiobarbituric acid, and 
barbituric acid and said substituents are selected from the group 
consisting of cyano, methyl, ethyl and phenyl; 
R.sup.1 and R.sup.2 represent methyl, phenyl, --CH.dbd.(CH--CH).sub.m 
.dbd.A.sup.1 ; or --CH.dbd.CH--A.sup.2 wherein 
m is 0 or 1; 
A.sup.1 may represent benzoxazole, benzothiazole, naphtho1,2-d!thiazole, 
3H-indole and 2-quinoline and A.sup.2 may represent dialkylaminophenyl 
where alkyl consists of 1-4 carbons, alkoxyphenyl where alkoxy consists of 
1-4 carbons, 4-dialkylamino-2-alkoxyphenyl, furan and 
2,3,6,7-tetrahydro-1H,5H-benzoij!quinoline. 
In general the materials of Formula I which have been found to be 
electrophotosensitive tend to exhibit a maximum absorption wavelength, 
.lambda.max, within the range of from about 420 to about 750 nm. A variety 
of different materials within the class defined by Formula I have been 
tested and found to exhibit useful levels of electrical photosensitivity 
in electrophoretic migration imaging processes. 
A partial listing of representative such materials is included herein in 
Tables I through XI. 
TABLE I 
______________________________________ 
##STR7## 
No. R.sub.1 and R.sub.2 Color 
______________________________________ 
##STR8## Reddish Brown 
2 
##STR9## Purple 
3 
##STR10## Yellow 
4 
##STR11## Reddish Orange 
5 
##STR12## Dark Purple 
6 
##STR13## Brown 
7 
##STR14## Red 
8 
##STR15## Orange 
9 
##STR16## Orange 
10 
##STR17## Yellow 
11 
##STR18## Purple 
12 
##STR19## Reddish Brown 
13 
##STR20## Purple 
14 
##STR21## Black 
______________________________________ 
TABLE II 
______________________________________ 
##STR22## 
No. R.sub.2 Color 
______________________________________ 
15 
##STR23## Reddish Purple 
16 
##STR24## Purple 
17 
##STR25## Reddish Brown 
18 
##STR26## Yellow 
19 
##STR27## Orange 
20 
##STR28## Orange 
21 
##STR29## Brownish Purple 
22 
##STR30## Purple 
23 
##STR31## Orange 
24 
##STR32## Orange 
25 
##STR33## Purple 
26 
##STR34## Brown 
27 
##STR35## Purple 
28 
##STR36## Orange 
29 
##STR37## Orange 
30 
##STR38## Orange 
31 
##STR39## Reddish Brown 
32 
##STR40## Reddish Brown 
33 
##STR41## Reddish Brown 
34 
##STR42## Aqua- Black 
35 
##STR43## Reddish Purple 
36 
##STR44## Purple 
37 
##STR45## Purple 
38 
##STR46## Purple 
39 
##STR47## Blue Black 
40 
##STR48## Orange 
41 
##STR49## Blue Black 
______________________________________ 
TABLE III 
______________________________________ 
##STR50## 
Number 
R.sub.2 Color 
______________________________________ 
42 
##STR51## Reddish Purple 
43 
##STR52## Purple 
44 
##STR53## Purple 
45 
##STR54## Purple 
46 
##STR55## Brownish Black 
47 
##STR56## Brown 
48 
##STR57## Black 
49 
##STR58## Black 
______________________________________ 
TABLE IV 
__________________________________________________________________________ 
##STR59## 
Number 
R.sub.1 Color 
__________________________________________________________________________ 
50 
##STR60## Black 
51 
##STR61## Black 
52 
##STR62## Blue Black 
53 
##STR63## Brown Black 
54 
##STR64## Black 
55 
##STR65## Green 
56 
##STR66## Brown 
57 
##STR67## Green 
58 
##STR68## Green 
59 
##STR69## Black 
60 
##STR70## Black 
61 
##STR71## Green 
62 
##STR72## Black 
63 
##STR73## Black 
64 
##STR74## Black 
__________________________________________________________________________ 
TABLE V 
______________________________________ 
##STR75## 
Number R.sub.1 and R.sub.2 Color 
______________________________________ 
65 
##STR76## Green 
66 
##STR77## Grey 
______________________________________ 
TABLE VI 
______________________________________ 
##STR78## 
Num- 
ber R.sub.1 Color 
______________________________________ 
67 
##STR79## Blue 
68 
##STR80## Purple 
69 
##STR81## Brown 
70 
##STR82## Blue 
71 
##STR83## Purple 
72 
##STR84## Red 
73 
##STR85## Magenta 
74 
##STR86## Orange 
75 
##STR87## Orange 
______________________________________ 
TABLE VII 
______________________________________ 
##STR88## 
Number R.sub.1 Color 
______________________________________ 
76 
##STR89## Purple 
77 
##STR90## Purple 
______________________________________ 
TABLE VIII 
______________________________________ 
##STR91## 
Number R.sub.1 and R.sub.2 Color 
______________________________________ 
78 
##STR92## Purple 
79 
##STR93## Purple 
80 
##STR94## Purple Black 
______________________________________ 
TABLE IX 
______________________________________ 
##STR95## 
Number R.sub.1 Color 
______________________________________ 
81 
##STR96## Purple 
82 
##STR97## Red 
83 
##STR98## Brown 
______________________________________ 
TABLE X 
______________________________________ 
##STR99## 
Number R.sub.1 Color 
______________________________________ 
84 
##STR100## Grey 
85 
##STR101## Orange 
86 
##STR102## Purple 
______________________________________ 
TABLE XI 
__________________________________________________________________________ 
Number Color 
__________________________________________________________________________ 
87 
##STR103## Purple 
88 
##STR104## Purplish Black 
89 
##STR105## Purplish Black 
90 
##STR106## Red 
91 
##STR107## Reddish Brown 
92 
##STR108## Grey 
93 
##STR109## Purple 
94 
##STR110## Purple 
95 
##STR111## Blue 
96 
##STR112## Purple 
97 
##STR113## Black 
98 
##STR114## Purplish Black 
99 
##STR115## Yellow 
100 
##STR116## Orange 
101 
##STR117## Yellow 
102 
##STR118## Black 
103 
##STR119## Black 
104 
##STR120## Orange 
105 
##STR121## Red 
106 
##STR122## Black 
107 
##STR123## Purple 
108 
##STR124## Purple Black 
109 
##STR125## Purple 
110 
##STR126## Grey 
111 
##STR127## Black 
__________________________________________________________________________ 
The materials described by general Formula I may be prepared by the various 
procedures. The procedures disclosed in U.S. Pat. No. 2,965,486 to Brooker 
et al., issued Dec. 20, 1960 may be used to prepare any of the compounds 
falling within the scope of general Formula I. 
As indicated hereinabove, the electrically photosensitive material 
described herein is useful in the preparation of the electrically 
photosensitive imaging particles used in electrophoretic migration imaging 
processes. In general, electrically photosensitive particles useful in 
such processes have an average particle size within the range of from 
about 0.01 micron to about 20 microns, preferably from about 0.01 to about 
5 microns. Typically, these particles are composed of one or more colorant 
materials such as the colorant materials described in the present 
invention. However, these electrically photosensitive particles may also 
contain various nonphotosensitive materials such as electrically 
insulating polymers, charge control agents, various organic and inorganic 
fillers, as well as various additional dyes or pigment materials to change 
or enhance various colorant and physical properties of the electrically 
photosensitive particle. In addition, such electrically photosensitive 
particles may contain other photosensitive materials such as various 
sensitizing dyes and/or chemical sensitizers to alter or enhance their 
response characteristics to activating radiation. 
When used in an electrophoretic migration imaging process in accord with 
the present invention, the electrically photosensitive material described 
in Tables I through XI, hereinabove, are typically positioned in 
particulate form, between two or more spaced electrodes, one or both of 
which typically being transparent to radiation to which the electrically 
photosensitive material is light-sensitive, i.e., activating radiation. 
Although the electrically photosensitive material, in particulate form, 
may be dispersed simply as a dry powder between two spaced electrodes and 
then subjected to a typical electrophoretic migration imaging operation 
such as that described in U.S. Pat. No. 2,758,939 by Sugarman, it is more 
typical to disperse the electrically photosensitive particulate material 
in an electrically insulating carrier, such as an electrically insulating 
liquid, or an electrically insulating, liquefiable matrix material, such 
as a heat- and/or solvent-softenable polymeric material or a thixotropic 
polymeric material. Typically, when one employs such a dispersion of 
electrically photosensitive particulate material and electrically 
insulating carrier material between the spaced electrodes of an 
electrophoretic migration imaging system, it is conventional to employ 
from about 0.05 part to about 2.0 parts of electrically photosensitive 
particulate material for each 10 parts by weight of electrically 
insulating carrier material. 
As indicated above, when the electrically photosensitive particles used in 
the present invention are dispersed in an electrically insulating carrier 
material, such carrier material may assume a variety of physical forms and 
may be selected from a variety of different materials. For example the 
carrier material may be a matrix of an electrically insulating, normally 
solid polymeric material capable of being softened or liquefied upon 
application of heat, solvent, and/or pressure so that the electrically 
photosensitive particulate material dispersed therein can migrate through 
the matrix. In another, more typical embodiment of the invention, the 
carrier material can comprise an electrically insulating liquid such as 
decane, paraffin, Sohio Oderless Solvent 3440 (a kerosene fraction 
marketed by the Standard Oil Company, Ohio), various isoparaffinic 
hydrocarbon liquids such as those sold under the trademark Isopar G by 
Exxon Corporation and having a boiling point in the range of 145.degree. 
C. to 186.degree. C., various halogenated hydrocarbons such as carbon 
tetrachloride, trichloromonofluoromethane, and the like, various alkylated 
aromatic hydrocarbon liquids such as the alkylated benzenes, for example, 
xylenes, and other alkylated aromatic hydrocarbons such as are described 
in U.S. Pat. No. 2,899,335. An example of one such useful alkylated 
aromatic hydrocarbon liquid which is commercially available is Solvesso 
100 made by Exxon Corporation. Solvesso 100 has a boiling point in the 
range of about 157.degree. C. to about 177.degree. C. and is composed of 9 
percent dialkyl benzenes, 37 percent trialkyl benzenes, and 4 percent 
aliphatics. Typically, whether solid or liquid at normal room 
temperatures, i.e., about 22.degree. C., the electrically insulating 
carrier material used in the present invention is a material having a 
resistivity greater than about 10.sup.9 ohm-cm, preferably greater than 
about 10.sup.12 ohm-cm. When the electrically photosensitive particles 
formed from the materials of the present invention are incorporated in a 
carrier material, such as one of the above-described electrically 
insulating liquids, various other addenda may also be incorporated in the 
resultant imaging suspension. For example, various charge control agents 
may be incorporated in such a suspension to improve the uniformity of 
charge polarity of the electrically photosensitive particles dispersed in 
the liquid suspension. Such charge control agents are well known in the 
field of liquid electrographic developer compositions where they are 
employed for purposes substantially similar to that described herein. 
Thus, extensive discussion of the materials herein is deemed unnecessary. 
These materials are typically polymeric materials incorporated by 
admixture thereof into the liquid carrier vehicle of the suspension. In 
addition to, and possibly related to, the aforementioned enhancement of 
uniform charge polarity, it has been found that the charge control agents 
often provide more stable suspensions, i.e., suspensions which exhibit 
substantially less settling out of the dispersed photosensitive particles. 
In addition to the foregoing charge control agent materials, various 
polymeric binder materials such as various natural, semi-synthetic or 
synthetic resins, may be dispersed or dissolved in the electrically 
insulating carrier to serve as a fixing material for the final 
photosensitive particle image formed on one of the spaced electrodes used 
in electrophoretic migration imaging systems. Here again, the use of such 
fixing addenda is conventional and well known in the closely related art 
of liquid electrographic developer compositions so that extended 
discussion thereof is unnecessary herein. 
The process of the present invention will be described in more detail with 
reference to the accompanying drawing, FIG. 1, which illustrates a typical 
apparatus which employs the electrophoretic migration imaging process of 
the invention. 
FIG. 1 shows a transparent electrode 1 supported by two rubber drive 
rollers 10 capable of imparting a translating motion to electrode 1 in the 
direction of the arrow. Electrode 1 may be composed of a layer of 
optically transparent material, such as glass or an electrically 
insulating, transparent polymeric support such as polyethylene 
terephthalate, covered with a thin, optically transparent, conductive 
layer such as tin oxide, indium oxide, nickel, and the like. Optionally, 
depending upon the particular type of electrophoretic migration imaging 
process desired, the surface of electrode 1 may bear a "dark charge 
exchange" material, such as a solid solution of an electrically insulating 
polymer and 2,4,7,trinitro-9-fluorenone as described by Groner in U.S. 
Pat. No. 3,976,485 issued Aug. 24, 1976. 
Spaced opposite electrode 1 and in pressure contact therewith is a second 
electrode 5, an idler roller which serves as a counter electrode to 
electrode 1 for producing the electric field used in the electrophoretic 
migration imaging process. Typically, electrode 5 has on the surface 
thereof a thin, electrically insulating layer 6. Electrode 5 is connected 
to one side of the power source 15 by switch 7. The opposite side of the 
power source 15 is connected to electrode 1 so that as an exposure takes 
place, switch 7 is closed and an electric field is applied to the 
electrically photosensitive particulate material 4 which is positioned 
between electrodes 1 and 5. Typically electrically photosensitive 
particulate material 4 is dispersed in an electrically insulating carrier 
material such as described hereinabove. 
The electrically photosensitive particulate material 4 may be positioned 
between electrodes 1 and 5 by applying material 4 to either or both of the 
surfaces of electrodes 1 and 5 prior to the imaging process or by 
injecting electrically photosensitive imaging material 4 between 
electrodes 1 and 5 during the electrophoretic migration imaging process. 
As shown in FIG. 1, exposure of electrically photosensitive particulate 
material 4 takes place by use of an exposure system consisting of light 
source 8, an original image 11 to be reproduced, such as a photographic 
transparency, a lens system 12, and any necessary or desirable radiation 
filters 13, such as color filters, whereby electrically photosensitive 
material 4 is irradiated with a pattern of activating radiation 
corresponding to original image 11. Although the electrophoretic migration 
imaging system represented in FIG. 1 shows electrode 1 to be transparent 
to activating radiation from light source 8, it is possible to irradiate 
electrically photosensitive particulate material 4 in the nip 21 between 
electrodes 1 and 5 without either of electrodes 1 or 5 being transparent. 
In such a system, although not shown in FIG. 1, the exposure source 8 and 
lens system 12 is arranged so that image material 4 is exposed in the nip 
or gap 21 between electrodes 1 and 5. 
As shown in FIG. 1, electrode 5 is a roller electrode having a conductive 
core 14 connected to power source 15. The core is in turn covered with a 
layer of insulating material 6, for example, baryta paper. Insulating 
material 6 serves to prevent or at least substantially reduce the 
capability of electrically photosensitive particulate material 4 to 
undergo a radiation induced charge alteration upon interaction with 
electrode 5. Hence, the term "blocking electrode" may be used, as is 
conventional in the art of electrophoretic migration imaging, to refer to 
electrode 5. 
Although electrode 5 is shown as a roller electrode and electrode 1 is 
shown as essentially a translatable, flat plate electrode in FIG. 1, 
either or both of these electrodes may assume a variety of different 
shapes such as a web electrode, rotating drum electrode, plate electrode, 
and the like as is well known in the field of electrophoretic migration 
imaging. In general, during a typical electrophoretic migration imaging 
process within electrically photosensitive material 4 is dispersed in an 
electrically insulating, liquid carrier, electrodes 1 and 5 are spaced 
such that they are in pressure contact or very close to one another during 
the electrophoretic migration imaging process, e.g., less than 50 microns 
apart. However, where electrically photosensitive particulate material 4 
is dispersed simply in an air gap between electrodes 1 and 5 or in a 
carrier such as a layer of heat-softenable or other liquefiable material 
coated as a separate layer on electrode 1 and/or 5, these electrodes may 
be spaced more than 50 microns apart during the imaging process. 
The strength of the electric field imposed between electrodes 1 and 5 
during the electrophoretic migration imaging process of the present 
invention may vary considerably; however, it has generally been found that 
optimum image density and resolution are obtained by increasing the field 
strength to as high a level as possible without causing electrical 
breakdown of the carrier medium in the electrode gap. For example, when 
electrically insulating liquids such as isoparaffinic hydrocarbons are 
used as the carrier in the imaging apparatus of FIG. 1, the applied 
voltage across electrodes 1 and 5 typically is within the range of from 
about 100 volts to about 4 kilovolts or higher. 
As explained hereinabove, image formation occurs in electrophoretic 
migration imaging processes as the result of the combined action of 
activating radiation and electric field on the electrically photosensitive 
particulate material 4 disposed between electrodes 1 and 5 in the attached 
drawing. Typically, for best results, field application and exposure to 
activating radiation occur concurrently. However, as would be expected, by 
appropriate selection of various process parameters such as field 
strength, activating radiation intensity, incorporation of suitable light 
sensitive addenda in or together with the electrically photosensitive 
particles formed from the material of Formula I, e.g., by incorporation of 
a persistent photoconductive material, and the like, it is possible to 
alter the timing of the exposure and field application events so that one 
may use sequential exposure and field application events rather than 
convurrent field application and exposure events. 
When disposed between imaging electrodes 1 and 5 of FIG. 1, electrically 
photosensitive particulate material 4 exhibits an electrostatic charge 
polarity, either as a result of triboelectric interaction of the particles 
or as a result of the particles interacting with the carrier material in 
which they are dispersed, for example, an electrically insulating liquid, 
such as occurs in conventional liquid electrographic developing 
compositions composed of toner particles which acquire a charge upon being 
dispersed in an electrically insulating carrier liquid. 
Image discrimination occurs in the electrophoretic migration imaging 
process of the present invention as a result of the combined application 
of electric field and activating radiation on the electrically 
photosensitive particulate material dispersed between electrodes 1 and 5 
of the apparatus shown in FIG. 1. That is, in a typical imaging operation, 
upon application of an electric field between electrodes 1 and 5, the 
particles 4 of charge-bearing, electrically photosensitive material are 
attracted in the dark to either electrodes 1 or 5, depending upon which of 
these electrodes has a polarity opposite to that of the original charge 
polarity acquired by the electrically photosensitive particles. And, upon 
exposing particles 4 to activating electromagnetic radiation, it is 
theorized that there occurs neutralization or reversal of the charge 
polarity associated with either the exposed or unexposed particles. In 
typical electrophoretic migration imaging systems wherein electrode 1 
bears a conductive surface, the exposed, electrically photosensitive 
particles 4, upon coming into electrical contact with such conductive 
surface, undergo an alteration (usually a reversal) of their original 
charge polarity as a result of the combined application of electric field 
and activating radiation. Alternatively, in the case of photoimmobilized 
electrophoretic recording (PIER), wherein the surface of electrode 1 bears 
a dark charge exchange material as described by Groner in aforementioned 
U.S. Pat. No. 3,976,485, one obtains reversal of the charge polarity of 
the unexposed particles, while maintaining the original charge polarity of 
the exposed electrically photosensitive particles, as these particles come 
into electrical contact with the dark charge exchange surface of electrode 
1. In any case, upon the application of electric field and activating 
radiation to electrically photosensitive particulate material 4 disposed 
between electrodes 1 and 5 of the apparatus shown in FIG. 1, one can 
effectively obtain image discrimination so that an image pattern is formed 
by the electrically photosensitive particles which corresponds to the 
original pattern of activating radiation. Typically, using the apparatus 
shown in FIG. 1, one obtains a visible image on the surface of electrode 1 
and a complementary image pattern on the surface of electrode 5. 
Subsequent to the application of the electric field and exposure to 
activating radiation, the images which are formed on the surface of 
electrodes 1 and/or 5 of the apparatus shown in FIG. 1 may be temporarily 
or permanently fixed to these electrodes or may be transferred to a final 
image receiving element. Fixing of the final particle image can be 
effected by various techniques, for example, by applying a resinous 
coating over the surface of the image bearing substrate. For example, if 
electrically photosensitive particles 4 are dispersed in a liquid carrier 
between electrodes 1 and 5, one may fix the image or images formed on the 
surface of electrodes 1 and/or 5 by incorporating a polymeric binder 
material in the carrier liquid. Many such binders (which are well known 
for use in liquid electrophotographic liquid developers) are known to 
acquire a change polarity upon being admixed in a carrier liquid and 
therefore will, themselves, electrophoretically migrate to the surface of 
one or the other of the electrodes. Alternatively, a coating of a resinous 
binder (which has been admixed in the carrier liquid), may be formed on 
the surfaces of electrodes 1 and/or 5 upon evaporation of the liquid 
carrier. 
The electrically photosensitive colorant material of Formula I may be used 
to form monochrome images, or the material may be admixed with other 
electrically photosensitive material of proper color and photosensitivity 
and used to form polychrome images. Said electrically photosensitive 
colorant material of the present invention also may be used as a 
sensitizer for other electrophotosensitive material in the formation of 
monochrome images. When admixed with other electrically photosensitive 
materials, selectively the photosensitive material of the present 
invention may act as a sensitizer and/or as an electrically photosensitive 
particle. Many of the electrically photosensitive colorant materials 
having Formula I have especially useful hues which make them particularly 
suited for use in polychrome imaging processes which employ a mixture of 
two or more differently colored electrically photosensitive particles. 
When such a mixture of multicolored electrically photosensitive particles 
is formed, for example, in an electrically insulating carrier liquid, this 
liquid mixture of particulate material exhibits a black coloration. 
Preferably, the specific cyan, magenta, and yellow particles selected for 
use in such a polychrome imaging process are chosen so that their spectral 
response curves do not appreciably overlap whereby color separation and 
subtractive multicolor image reproduction can be achieved. 
The following examples illustrate the utility of the Formula I materials in 
electrophoretic migration imaging processes. 
EXAMPLES 1-82 
Imaging Apparatus 
An imaging apparatus was used in each of the following examples to carry 
out the electrophoretic migration imaging process described herein. This 
apparatus was a device of the type illustrated in FIG. 1. In this 
apparatus, a translating film based having a conductive coating of 0.1 
optical density cermet (Cr.SiO) served as electrode 1 and was in pressure 
contact with a 10 centimeter diameter aluminum roller 14 covered with 
dielectric paper coated with poly(vinyl butyral) resin which served as 
electrode 5. Plate 1 was supported by two 2.8 cm. diameter rubber drive 
rollers 10 positioned beneath film plate 1 such that a 2.5 cm. opening, 
symmetric with the axis of the aluminum roller 14, existed to allow 
exposure of electrically photosensitive particles 4 to activating 
radiation. The original transparency 11 to be reproduced was taped to the 
back side of film plate 1. 
The original transparency to be reproduced consisted of adjacent strips of 
clear (W0), red (W29), green (W61) and blue (W47B) filters. The light 
source consisted of a Kodak Ektagraphic AV434A Carousel Projector with a 
1000 watt Xenon Lamp. The light was modulated with a Kodak No. 5 flexible 
M-carbon eleven step 0.3 neutral density step tablet. The residence time 
in the action zone was 10 milliseconds. The log of the light intensity 
(Log I) was as follows: 
______________________________________ 
Log I 
Filters erg/cm.sup.2 /sec. 
______________________________________ 
WO Clear 5.34 
W29 Red 4.18 
W61 Green 4.17 
W47B Blue 4.15 
______________________________________ 
The voltage between the electrode 5 and film plate 1 was about 2 kv. Film 
plate 1 was negative polarity in the case where electrically 
photosensitive particulate material 4 carried a positive electrostatic 
charge, and film plate 1 was positive in the case where electrically 
photosensitive electrostatically charged particles were negatively 
charged. The translational speed of film plate 1 was about 25 cm. per 
second. In the following examples, image formation occurs on the surfaces 
of film plate 1 and electrode 5 after simultaneous application of light 
exposure and electric field to electrically photosensitive material 
evaluated for use as electrically photosensitive particulate material 4 
was admixed with a liquid carrier as described below to form a liquid 
imaging dispersion which was placed in nip 21 between the electrodes 1 and 
5. If the material being evaluated for use as material 4 possessed a 
useful level of electrical photosensitivity, one obtained a 
negative-appearing image reproduction of original 11 on electrode 5 and a 
complementary image on electrode 1. 
Imaging Dispersion Preparation 
Imaging dispersions were prepared to evaluate each of the materials in 
Tables I through XI. The dispersions were prepared by first making a stock 
solution of the following components. The stock solution was prepared 
simply by combining the components. 
______________________________________ 
Isopar G 2.2 g 
Solvesso 1.3 g 
Piccotex 100 1.4 g 
PVT* 0.1 g 
______________________________________ 
*Poly(vinyltoluene-co-lauryl methacrylate-co-lithium 
methacylate-co-methacrylic acid 56/40/3.6/0.4 
A 5 g. aliquot of the stock solution was combined in a closed container 
with 0.045 g. of the Table I material to be tested and 12 g. of Hamber 440 
stainless steel balls. The preparation was then milled for three hours on 
a paint shaker. 
Each of the 82 materials described in Table I through XI were tested 
according to the just outlined procedures. Each of such materials were 
found to be electrophotosensitive as evidenced by obtaining a negative 
appearing image of the original on one electrode and a complementary image 
on the other electrode. Materials 1, 2, 3, 5, 7, 9, 11, 12, 13, 14, 20, 
21, 25, 26, 27, 28, 30, 32, 33, 34, 35, 36, 37, 38, 40, 41, 42, 43, 44, 
46, 49, 50, 51, 53, 55, 56, 59, 61, 63, 65, 69, 71, 73, 74, 75, 77, 78 and 
80 provide images having good to excellent quality. Image quality was 
determined visually having regard to minimum and maximum densities, speed 
and color saturation. 
The invention has been described in detail with particular reference to 
certain preferred embodiments thereof, but it will be understood that 
variations and modifications can be effected within the spirit and scope 
of the invention.