Radiation imagery chemistry: process – composition – or product th – Electric or magnetic imagery – e.g. – xerography,... – Radiation-sensitive composition or product
Reexamination Certificate
2003-05-30
2004-06-15
Chapman, Mark A. (Department: 1756)
Radiation imagery chemistry: process, composition, or product th
Electric or magnetic imagery, e.g., xerography,...
Radiation-sensitive composition or product
C430S058400, C548S416000
Reexamination Certificate
active
06749978
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to organophotoreceptors suitable for use in electrophotography and, more specifically, to organophotoreceptors having novel charge transport compounds.
2. Background of the Art
In electrophotography, an organophotoreceptor in the form of a plate, disk, sheet, belt, or drum having an electrically insulating photoconductive element on an electrically conductive substrate is imaged by first uniformly electrostatically charging the surface of the photoconductive layer, and then exposing the charged surface to a pattern of light. The light exposure selectively dissipates the charge in the illuminated areas, thereby forming a pattern of charged and uncharged areas. A liquid or solid toner is then deposited in either the charged or uncharged areas to create a toned image on the surface of the photoconductive layer. The resulting visible toner image can be transferred to a suitable receiving surface such as paper. The imaging process can be repeated many times.
Both single layer and multilayer photoconductive elements have been used. In the single layer embodiment, a charge transport material and charge generating material are combined with a polymeric binder and then deposited on the electrically conductive substrate. In the multilayer embodiment, the charge transport material and charge generating material are in the form of separate layers, each of which can optionally be combined with a polymeric binder, deposited on the electrically conductive substrate. Two arrangements are possible. In one arrangement (the “dual layer” arrangement), the charge generating layer is deposited on the electrically conductive substrate and the charge transport layer is deposited on top of the charge generating layer. In an alternate arrangement (the “inverted dual layer” arrangement), the order of the charge transport layer and charge generating layer is reversed.
In both the single and multilayer photoconductive elements, the purpose of the charge generating material is to generate charge carriers (i.e., holes and electrons) upon exposure to light. The purpose of the charge transport material is to accept these charge carriers and transport them through the charge transport layer in order to discharge a surface charge on the photoconductive element.
To produce high quality images, particularly after multiple cycles, it is desirable for the charge transport material to form a homogeneous solution with the polymeric binder and remain in solution. In addition, it is desirable to maximize the amount of charge which the charge transport material can accept (indicated by a parameter known as the acceptance voltage or “V
acc
”), and to minimize retention of that charge upon discharge (indicated by a parameter known as the discharge voltage or “V
dis
”).
There are many charge transport materials available for electrophotography. The most common charge transport materials are pyrazoline derivatives, fluorene derivatives, oxadiazole derivatives, stilbene derivatives, hydrazone derivatives, carbazole hydrazone derivatives, polyvinyl carbazole, polyvinyl pyrene, or polyacenaphthylene. However, each of the above charge transport materials suffers some disadvantages. There is always a need for novel charge transport materials to meet the various requirements of electrophotography applications.
SUMMARY OF THE INVENTION
A charge transport compound having the following generic formula:
(R—Q)
n−
Y Formula I
wherein R is a heterocyclic group, preferably a heterocyclic group selected from the group consisting of julolidine ring groups, carbazole ring groups, and (N,N-disubstituted)arylamine groups such as dialkarylamine groups (e.g. dimethylphenylamine; methylethylphenylamine, dipropylphenylamine, ethylepropylphenylamine, ethylbutylnaphthylamine, etc.), alkyldiarylamine groups (e.g. methyldiphenylamino, ethyldiphenylamino, etc), and triarylamino groups (e.g., triphenyl amino, trinaphthylamino, etc), wherein it is preferred that at least one of the n R groups comprises (N,N-disubstituted)arylamine groups such as dialkarylamine groups, alkyldiarylamine groups, etc), and triarylamino groups;
Q comprises an aromatic hydrazone linking group, such as
Y comprises a bridging group between R—Q— groups, such as a bond, carbon atom, nitrogen atom, oxygen atom, sulfur atom, a branched or linear —(CH
2
)
p
— group where p is an integer between 0 and 10, an aryl group, a cycloalkyl group, a cyclosiloxyl group (e.g., a cyclotetrasiloxyl group), a heterocyclic group, or a CR
10
group where R
10
is hydrogen atom, an alkyl group, or aryl group;
Z is an aryl group, preferably a phenyl group or naphthyl group;
X is a linking group, preferably a methylene group, and for example having the formula —(CH
2
)
m
— (branched or linear), where m is an integer between 0 and 20, inclusive, and one or more of the methylene groups is optionally replaced by an oxygen atom, a carbonyl group, urethane, urea, an ester group, a —NR
6
group, a CHR
7
group, or a CR
8
R
9
group where R
6
, R
7
, R
8
, and R
9
are, independently, H, an alkyl group, or aryl group; and
n is an integer between 2 and 6, inclusive.
In another aspect of the invention, the invention features an organic photoreceptor that includes:
(a) a charge transport compound having the formula
(R—Q)
n−
Y Formula I
wherein R is a heterocyclic group, preferably a heterocyclic group selected from the group consisting of julolidine ring groups, carbazole ring groups, and (N,N-disubstituted)arylamine groups such as dialkarylamine groups (e.g. dimethylphenylamine; methylethylphenylamine, dipropylphenylamine, ethylepropylphenylamine, ethylbutylnaphthylamine, etc.), alkyldiarylamine groups (e.g. methyldiphenylamino, ethyldiphenylamino, etc), and triarylamino groups (e.g., triphenyl amino, trinaphthylamino, etc) wherein it is preferred that at least one of the n R groups comprises (N,N-disubstituted)arylamine groups such as dialkarylamine groups, alkyldiarylamine groups, etc), and triarylamino groups;
Q comprises an aromatic hydrazone linking group, such as
Y comprises a bridging group, preferably a divalent linking group, between R—Q— groups, such as a bond, carbon atom, nitrogen atom, oxygen atom, sulfur atom, a branched or linear —(CH
2
)
p
— group where p is an integer between 0 and 10, an aryl group, a cycloalkyl group, a cyclosiloxyl group (e.g., a cyclotetrasiloxyl group), a heterocyclic group, or a CR
10
group where R
10
is hydrogen atom, an alkyl group, or aryl group;
Z is an aryl group, preferably a phenyl group or naphthyl group;
X is a linking group, preferably a methylene group, and for example having the formula —(CH
2
)
m
— (branched or linear), where m is an integer between 0 and 20, inclusive, and one or more of the methylene groups is optionally replaced by an oxygen atom, a carbonyl group, urethane, urea, an ester group, a —NR
6
group, a CHR
7
group, or a CR
8
R
9
group where R
6
, R
7
, R
8
, and R
9
are, independently, H, an alkyl group, or aryl group; and
n is an integer between 2 and 6, inclusive;
(b) a charge generating compound; and
(c) an electrically conductive substrate.
DETAILED DESCRIPTION OF THE INVENTION
A charge transport compound having the following generic formula:
(R—Q)
n−
Y Formula I
wherein R is a heterocyclic group, preferably a heterocyclic group selected from the group consisting of julolidine ring groups, carbazole ring groups, and (N,N-disubstituted)arylamine groups such as dialkarylamine groups (e.g. dimethylphenylamine; methylethylphenylamine, dipropylphenylamine, ethylepropylphenylamine, ethylbutylnaphthylamine, etc.), alkyldiarylamine groups (e.g. methyldiphenylamino, ethyldiphenylamino, etc), and triarylamino groups (e.g., triphenyl amino, trinaphthylamino, etc) wherein it is preferred that at least one of the n R groups comprises (N,N-disubstituted)arylamine groups such as dialkarylamine groups, alkyldiarylamine groups, etc), and triarylamino groups (and 1, 2, 3, 4, 5 or 6 R groups may be selected from these prefer
Gaidelis Valentas
Getautis Vytautas
Jankauskas Vygintas
Jubran Nusrallah
Law Kam
Chapman Mark A.
Patterson Thuente Skaar & Christensen P.A.
Samsung Electronics Co,. Ltd.
LandOfFree
Electrophotographic organophotoreceptors with novel charge... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electrophotographic organophotoreceptors with novel charge..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electrophotographic organophotoreceptors with novel charge... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3358802