U.S. patent application number 09/771714 was filed with the patent office on 2002-01-03 for phthalocyanine crystal, production process therefor, and electrophotographic photosensitive member, process cartridge and apparatus using the crystal.
Invention is credited to Asakura, Kazue, Fujii, Atsushi, Hirano, Hidetoshi, Tanabe, Kan, Tanaka, Masato.
Application Number | 20020001765 09/771714 |
Document ID | / |
Family ID | 18548888 |
Filed Date | 2002-01-03 |
United States Patent
Application |
20020001765 |
Kind Code |
A1 |
Tanaka, Masato ; et
al. |
January 3, 2002 |
Phthalocyanine crystal, production process therefor, and
electrophotographic photosensitive member, process cartridge and
apparatus using the crystal
Abstract
An electrophotographic photosensitive member exhibiting a high
sensitivity and a potential stability on repetitive use and capable
of suppressing image defects, such as black spots in a reversal
development scheme, is provided. The photosensitive member includes
a support, and a phthalocyanine layer formed on the support and a
novel phthalocyanine crystal, which comprises a phthalocyanine
compound and a substituted or unsubstituted condensed polycyclic
hydrocarbon compound.
Inventors: |
Tanaka, Masato;
(Shizuoka-ken, JP) ; Hirano, Hidetoshi;
(Shizuoka-ken, JP) ; Tanabe, Kan; (Shizuoka-ken,
JP) ; Asakura, Kazue; (Shizuoka-ken, JP) ;
Fujii, Atsushi; (Shizuoka-ken, JP) |
Correspondence
Address: |
FITZPATRICK CELLA HARPER & SCINTO
30 ROCKEFELLER PLAZA
NEW YORK
NY
10112
US
|
Family ID: |
18548888 |
Appl. No.: |
09/771714 |
Filed: |
January 30, 2001 |
Current U.S.
Class: |
430/59.4 ;
106/413; 399/159; 430/78 |
Current CPC
Class: |
C09B 67/0019 20130101;
C09B 67/0026 20130101; G03G 5/0696 20130101; C09B 67/0023
20130101 |
Class at
Publication: |
430/59.4 ;
106/413; 430/78; 399/159 |
International
Class: |
G03G 005/047; G03G
005/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 31, 2000 |
JP |
022611/2000 |
Claims
What is claimed is:
1. A phthalocyanine crystal, comprising; a phthalocyanine compound
and a substituted or unsubstituted condensed polycyclic hydrocarbon
compound.
2. A phthalocyanine crystal according to claim 1, wherein said
phthalocyanine compound is gallium phthalocyanine.
3. A phthalocyanine crystal according to claim 2, wherein said
gallium phthalocyanine is hydroxygallium phthalocyanine.
4. A phthalocyanine crystal according to claim 3, having a crystal
form characterized by strong peaks at Bragg angles 2.theta. of 7.4
deg..+-.0.2 deg. and 28.2 deg..+-.0.2 deg.
5. A phthalocyanine crystal according to claim 1, wherein said
substituted or unsubstituted condensed polycyclic hydrocarbon
compound is a halo-substituted condensed polycyclic hydrocarbon
compound.
6. A phthalocyanine crystal according to claim 5, wherein said
halo-substituted condensed polycyclic hydrocarbon compound is
.alpha.-chloronaphthalene.
7. A phthalocyanine crystal according to claim 1, wherein said
substituted or an substituted condensed polycyclic hydrocarbon
compound is naphthalene.
8. A process for producing a phthalocyanine crystal comprising a
phthalocyanine compound and a substituted or unsubstituted
condensed polycyclic hydrocarbon compound, said process comprising
subjecting a phthalocyanine compound to an acid pasting step
including dissolving or dispersing the phthalocyanine compound in
an acid which has been mixed with a substituted or unsubstituted
condensed polycyclic hydrocarbon compound.
9. A process for producing a phthalocyanine crystal comprising a
phthalocyanine compound and a substituted or unsubstituted
condensed polycyclic hydrocarbon compound, said process comprising
subjecting a phthalocyanine compound to an acid pasting step
including dissolving or dispersing a phthalocyanine compound in an
acid to form a mixture, and adding the mixture into a solution
containing a substituted or unsubstituted condensed polycyclic
hydrocarbon compound.
10. A process for producing a phthalocyanine crystal comprising a
phthalocyanine compound and a substituted or unsubstituted
condensed polycyclic hydrocarbon compound, said process comprising
subjecting a crystal transformation step including milling a
phthalocyanine compound within a solvent containing a substituted
or unsubstituted condensed polycyclic hydrocarbon compound.
11. An electrophotographic photosensitive member, comprising: an
electroconductive support, and a photosensitive layer formed
thereon, wherein said photosensitive layer contains a
phthalocyanine crystal comprising a phthalocyanine compound and a
substituted or unsubstituted condensed polycyclic hydrocarbon
compound.
12. An electrophotographic photosensitive member according to claim
11, wherein the phthalocyanine layer is functionally divided into
at least two layers including a charge generation layer comprising
the phthalocyanine crystal, and a charge transport layer.
13. A process cartridge, comprising: an electrophotographic
photosensitive member and at least one means selected from the
group consisting of charging means, developing means and cleaning
means; said electrophotographic photosensitive member and said at
least one means being integrally supported and detachably mountable
to a main assembly of an electrophotographic apparatus, wherein
said electrophotographic photosensitive member comprises a support,
and a photosensitive layer disposed on the support and containing a
phthalocyanine compound which comprises a phthalocyanine compound
and a substituted or unsubstituted condensed polycyclic hydrocarbon
compound.
14. An electrophotographic apparatus, comprising: an
electrophotographic photosensitive member, and charging means,
developing means and transfer means respectively disposed opposite
to the electrophotographic photosensitive member, wherein said
electrophotographic photosensitive member comprises a support, and
a photosensitive layer disposed on the support and containing a
phthalocyanine compound which comprises a phthalocyanine compound
and a substituted or unsubstituted condensed polycyclic hydrocarbon
compound.
Description
FIELD OF THE INVENTION AND RELATED ART
[0001] The present invention relates to a novel phthalocyanine
crystal, a process for producing the phthalocyanine crystal, an
electrophotographic photosensitive member using the phthalocyanine
crystal, and a process cartridge and an electrophotographic
apparatus including the photosensitive member.
[0002] As photoconductor materials for electrophotographic
photosensitive members, inorganic photoconductors, such as cadmium
sulfide, and zinc oxide, have been conventionally used. On the
other hand, organic photoconductors, such as polyvinyl carbazole,
oxadiazole, azo pigments and phthalocyanine have advantages of
non-pollution characteristic and high productivity compared with
the inorganic photoconductors but generally have a low conductivity
so that the commercialization thereof has been difficult. For this
reason, various sensitizing methods have been proposed, and among
them, the use of a unction separation-type photosensitive member
including a charge generation layer and a charge transport layer in
a laminated state has become predominant and has been
commercialized.
[0003] On the other hand, in recent years, non-impact-type printers
utilizing electrophotography have come into wide in place of
conventional impact-type printers as terminal printers. Such
non-impact-type printers principally comprise laser beam printers
using laser light as exposure light, and as the light source
thereof, semiconductor lasers have been predominantly used, in view
of the cost and apparatus size thereof. The semiconductor lasers
principally used currently have an oscillating wavelength in a long
wavelength region of 650-820 nm, so that electrophotographic
photosensitive members having a sufficient sensitivity in such a
long wavelength region have been developed.
[0004] Phthalocyanine compounds are very effective charge
generating materials having a sensitivity up to such a long
wavelength region, and compared with conventional phthalocyanine
compounds and polyvinyl carbazole, oxytitanium phthalocyanine, and
gallium phthalocyanine are known to have better sensitivities, and
various crystal forms thereof have been disclosed, e.g., in
Japanese Laid-Open Patent Application (JP-A) 61-239248, JP-A
61-217050, JP-A 62-67094, JP-A 63-218768, JP-A 64-17066, JP-A
5-98181, JP-A 5-263007 and JP-A 10-67946.
[0005] Further, it has been known that a phthalocyanine compound of
even a similar crystal form can exhibit remarkably different
electrophotographic performances, particularly in sensitivity and
chargeability, when used in an electrophotographic photosensitive
member depending on production process factors, such as starting
materials and solvents, and production conditions, such as reaction
temperatures and starting material charging ratios.
[0006] Production processes for gallium phthalocyanine crystals
have been disclosed in, e.g., JP-A 8-100134, JP-A 9-111148, JP-A
9-124967, JP-A 10-7927 and JP-A 10-17784. Furthers JP-A 7-331107
discloses a hydroxygallium phthalocyanine crystal containing a
polar solvent, such as N,N-dimethylformamide. Electrophotographic
photosensitive members using these gallium phthalocyanine crystals
are liable to exhibit a fluctuation in electrophotographic
performances depending on production lots and do not necessarily
have satisfactory sensitivity, potential stability in repetitive
use and chargeability in view of requirements for higher speed and
higher image quality in electrophotography in recent years.
[0007] Further, while having an excellent sensitivity to
long-wavelength region, an electrophotographic photosensitive
member using a phthalocyanine compound is accompanied with
difficulties, such as fluctuation in electrophotographic
performances depending on production lots and liability of image
defect (sometimes called "black spots"), that is, black spotty fog
occurring in a white background region in a reversal development
systems due to local charge injection, particularly in a high
temperature/high humidity environment. Further, the photosensitive
member is accompanied with a difficulty that its light-part
potential is liable to be fluctuated on repetitive use
SUMMARY OF THE INVENTION
[0008] In view of the above-mentioned problems of the prior art, a
principal object of the present invention is to provide an
electrophotographic photosensitive member exhibiting a
high-sensitivity characteristic particularly in a semiconductor
wavelength region, exhibiting a stable potential characteristic on
repetitive used and capable of reducing image defects, particularly
backspots in a reversal development scheme.
[0009] A further object of the present invention is to provide a
novel phthalocyanine crystal capable of providing such a
photosensitive member and a process for producing the
phthalocyanine crystal.
[0010] A still further object of the present invention is to
provide a process cartridge and an electrophotographic apparatus
including the photosensitive member.
[0011] According to the present invention, there is provided a
phthalocyanine crystal, comprising: a phthalocyanine compound and a
substituted or unsubstituted condensed polycyclic hydrocarbon
compound.
[0012] The present invention further provides some processes for
producing the above-mentioned phthalocyanine crystal.
[0013] The present invention also provides an electrophotographic
photosensitive member comprising a support, and a photosensitive
layer disposed on the support and containing the above-mentioned
phthalocyanine crystal.
[0014] The present invention further provides a process cartridge
and an electrophotographic apparatus respectively including the
above-mentioned electrophotographic photosensitive member.
[0015] These and other objects, features and advantages of the
present invention will become more apparent upon a consideration of
the following description of the preferred embodiments of the
present invention taken in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a schematic illustration of an electrophotographic
apparatus including an electrophotographic photosensitive member
according to the invention.
[0017] FIGS. 2 to 4 are schematic illustrations of
electrophotographic apparatus including different types of process
cartridges each including an electrophotographic photosensitive
member according to the invention.
[0018] FIG. 5 is an X-ray diffraction chart of chlorogallium
phthalocyanine obtained in Synthesis Example 1.
[0019] FIG. 6 is an X-ray diffraction chart of hydroxygallium
phthalocyanine obtained in Synthesis Example 2.
[0020] FIGS. 7-14 are X-ray diffraction charts of hydrogallium
phthalocyanine crystals obtained in Examples 1-8, respectively.
[0021] FIG. 15 is an X-ray diffraction chart of hydroxygallium
phthalocyanine crystal obtained in Comparative Example 1.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The phthalocyanine crystal of the present invention
comprises a phthalocyanine compound and a minor amount of
substituted or unsubstituted condensed polycyclic hydrocarbon
compound However, even if the phthalocyanine crystal of the present
invention is heated up to the melting point of the substituted or
unsubstituted condensed polycyclic hydrocarbon compound, the
hydrocarbon compound is not liberated from the phthalocyanine
crystal. Further, even if the phthalocyanine crystal of the present
invention is analyzed by liquid chromatography, the presence of the
hydrocarbon compound is not detected. From these facts, it is
believed that the hydrocarbon compound is not merely attached to
the phthalocyanine compound but is firmly held within the
phthalocyanine crystal.
[0023] Examples of the condensed polycyclic hydrocarbon compound
constituting the phthalocyanine crystal of the present invention
may include: pentalene, indene, naphthalene, azulene, heptalene,
biphenylene, indacene, acenaphthylene, fluorene, phenalene,
phenanthrene, anthracene, fluoroanthene, pyrene, naphthacene,
picene and perylene. Naphthalene is particularly preferred.
[0024] Examples of the substituent optionally possessed by the
above condensed polycyclic hydrocarbon compound may include: alkyl
groups, such as methyl and ethyl; alkoxy groups, such as methoxyl
and ethoxyl; alkylamino groups, such as dimethylamino and
diethylamino; nitro, cyano, haloalkyl groups such as
trifluoromethyl; halogen atoms, such as chorine, fluorine and
iodine. Halogen atoms are particularly preferred.
[0025] Among the above-enumerated substituted or unsubstituted
condensed polycyclic hydrocarbon compounds,
.alpha.-chloronaphthalene and naphthalene are particularly
preferred.
[0026] The substituted or unsubstituted condensed polycyclic
hydrocarbon compound may preferably be contained in a proportion of
100-50000 ppm based on the total weight of the phthalocyanine
crystal. Outside this range, it becomes difficult to attain the
remarkable effect of the present invention.
[0027] The phthalocyanine compound constituting the phthalocyanine
crystal of the present invention may comprise any forms of
phthalocyanines inclusive of non-metallic phthalocyanine, metal
phthalocyanines capable of having an axial ligand. The
phthalocyanine compound can also have a substituent and can have
any crystal form. In order for the phthalocyanine crystal of the
present invention to exhibit a particularly excellent sensitivity
characteristic, the phthalocyanine compound may preferably comprise
gallium phthalocyanine. Further, in the state containing the
substituted or unsubstituted condensed polycyclic hydrocarbon
compound, the phthalocyanine crystal of the present invention may
preferably comprise hydroxygallium phthalocyanine crystal having
crystal forms characterized by strong peaks at Bragg angles
2.theta. of 7.4 deg..+-.0.2 deg. and 28.2 deg..+-.0.2 deg. (i.e.,
any crystal forms each characterized by an X-ray diffraction
pattern showing a peaktop in a range of 7.2-7.6 deg. and a peaktop
in a range of 28.0-28.4 deg.) according to CuK.alpha.
characteristic X-ray diffractometry. Among these, a crystal form
characterized by strong peaks at Bragg angles 2.theta..+-.0.2 deg.
of 7.3 deg., 24.9 deg. and 28.1 deg., and a crystal form
characterized by strong peaks at Bragg angles 2.theta..+-.0.2 deg.
of 7.5 deg., 9.9 deg., 16.3 deg., 18.6 deg., 25.1 deg. and 28.3
deg. (Herein, ".+-.0.2 deg." in "2.theta..+-.0.2 deg." represents
an angle detection error generally recognized in X-ray
diffractometry.)
[0028] The phthalocyanine crystal according to the present
invention may be produced through various processes, inclusive of:
a process comprising subjecting a phthalocyanine compound to an
acid pasting step including dissolving or dispersing the
phthalocyanine compound in an acid in mixture with a substituted or
unsubstituted condensed polycyclic hydrocarbon compound; a process
comprising subjecting a phthalocyanine compound to an acid pasting
step including dissolving or dispersing a phthalocyanine compound
in an acid to form a mixture, and adding the mixture into a
solution containing a substituted or unsubstituted condensed
polycyclic hydrocarbon compound; and a process comprising
subjecting a crystal transformation step including milling a
phthalocyanine compound within a solvent containing a substituted
or unsubstituted condensed polycyclic hydrocarbon compound.
[0029] Herein, the acid pasting step means a step of treating a
phthalocyanine compound including dissolving or dispersing the
phthalocyanine compound in an acid, adding the resultant solution
or. dispersion into an aqueous medium to re-precipitate a
phthalocyanine solid, optionally washing the phthalocyanine solid
with an alkaline aqueous solution and washing the phthalocyanine
solid with de-ionized water. The washing with deionized water may
preferably be repeated until the after-washing water is caused to
have a conductivity of at most 20 .mu.S. The acid used may for
example be sulfuric acid, hydrochloric acid and trifluoroacetic
acid, and conc. sulfuric acid is particularly preferred. The acid
may preferably be used in an amount of 10-40 times the weight of
the phthalocyanine compound. The phthalocyanine compound may
preferably be dissolved or dispersed in the acid at a temperature
of at most 50.degree. C. so as to avoid the decomposition or
reaction with the acid of the phthalocyanine compound. The
substituted or unsubstituted condensed polycyclic hydrocarbon
compound may preferably be used in an amount of 0.01-2 times the
weight of the phthalocyanine compound in the case of dissolving or
dispersing the phthalocyanine compound in the acid already mixed
with the substituted or unsubstituted condensed polycyclic
hydrocarbon compound, or 0.01-10 times the weight of the
phthalocyanine compound in the case of adding the mixture of the
phthalocyanine compound with the acid into an aqueous medium
containing the substituted or unsubstituted condensed polycyclic
hydrocarbon compound.
[0030] As mentioned above, the phthalocyanine crystal according to
the present invention can also be produced through a process
comprising a step of milling a phthalocyanine compound within a
solvent containing a substituted or unsubstituted condensed
polycyclic hydrocarbon compound.
[0031] The milling may be performed within a milling apparatus,
such as a sand mill or a ball mill, wherein the phthalocyanine
compound is milled together with dispersion media, such as glass
beads, steel beads and alumina balls, in the presence of a solvent
containing a substituted or unsubstituted condensed polycyclic
hydrocarbon compound. The milling time can vary depending on the
milling apparatus used but may preferably be on the order of 4-48
hours. It is preferred to check the crystal form by CuK.alpha.
characteristic X-ray diffractometry for measuring the Bragg angles
at an interval of 4-8 hours each during the milling. The dispersion
medium may preferably be used in a weigh which is 10-50 times the
phthalocyanine compound. Examples of the solvent used in the
milling may include: amide solvents, such as N,N-dimethylformamide,
N,N-dimethylacetamide, N-methylformamide, N-methylacetamide and
N-methylpropioamide; halide solvents, such as chloroform; ether
solvents, such as tetrahydrofuran; and sulfoxide solvents, such as
dimethyl sulfoxide. The solvent may preferably be used in an amount
of 10-30 times the weight of the phthalocyanine compound. The
substituted or unsubstituted condensed polycyclic hydrocarbon
compound may preferably be used in an amount of 0.01-3 times the
weight of the phthalocyanine compound.
[0032] The X-ray diffraction data referred to herein for
determining the crystal form of phthalocyanine crystals are based
on data measured by X-ray diffractometry using CuK.sub..alpha.
characteristic X-rays according to the following conditions:
[0033] Apparatus: Full-automatic X-ray diffraction apparatus
("MXP18", available from MAC Science K.K.)
[0034] X-ray tube (Target): Cu
[0035] Tube voltage: 50 kV
[0036] Tube current: 300 mA
[0037] Scanning method: 2.theta./.theta. scan
[0038] Scanning speed: 2 deg./min.
[0039] Sampling interval: 0.020 deg.
[0040] Starting angle (2.theta.): 5 deg.
[0041] Stopping angle (2.theta.): 40 deg.
[0042] Divergence slit: 0.5 deg.
[0043] Scattering slit, 0.5 deg.
[0044] Receiving slit: 0.3 deg.
[0045] Curved monochromator: used.
[0046] Next, some embodiments of application of the phthalocyanine
crystal according to the present invention as a charge-generating
material in the electrophotographic photosensitive member will be
described.
[0047] The electrophotographic photosensitive member according to
the present invention may have a laminar structure including a
single photosensitive layer containing both a charge-generating
material and a charge-transporting material formed on an
electroconductive support, or alternatively a laminar
photosensitive layer including a charge generation layer containing
a charge-generating material and a charge transport layer
containing a charge-transporting material formed successively on an
electroconductive support. The order of lamination of the charge
generation layer and the charge transport layer can be reversed. It
is however preferred that the charge generation layer is disposed
below the charge transport layer.
[0048] The electroconductive support may comprise any material
exhibiting electroconductivity, examples of which may include:
metals. such as aluminum, aluminum alloys, copper, zinc, stainless
steel, vanadium, molybdenum, chromium, titanium, nickel, indium,
gold and platinum. In addition, it is also possible to use a
support comprising a plastic substrate of, e.g., polyethylene,
polypropylene. polyvinyl chloride, polyethylene terephthalate,
acrylic resin or polyethylene fluoride, and a coating film formed
thereon of a conductor such as aluminum, aluminum alloys, indium
oxide, tin oxide or indium tin oxide, formed by vacuum deposition;
a support comprising a plastic substrate or a support as mentioned
above further coated with a conductive coating layer comprising
electroconductive particles of, e.g., aluminum, titanium oxide, tin
oxide, zinc oxide, carbon black or silver, together with an
appropriate binder; a support comprising a plastic or paper
impregnated with electroconductive particles, or a plastic support
comprising an electroconductive polymer
[0049] It is possible to dispose an undercoating layer having a
barrier function and an adhesive function between the support and
the photosensitive layer. The undercoating layer may comprise a
material, such as polyvinyl alcohol, polyethylene oxide, ethyl
cellulose, methyl cellulose, casein, polyamide (e.g., nylon 6,
nylon 66, nylon 610, copolymer nylon and N-alkoxymethylated nylon),
polyurethane, glue, aluminum oxide or gelatine. The under coating
layer may preferably have a thickness of 0.1-10 .mu.m, particularly
0.5-5 .mu.m.
[0050] The single photosensitive layer may be formed by applying a
coating liquid comprising a mixture of the phthalocyanine crystal
according to the present invention as a charge-generating material
and a charge-transporting material within a solution of a binder
resin on the support optionally coated with the undercoating layer,
etc., followed by drying of the coating liquid.
[0051] For providing the laminated photosensitive layer, the charge
generation layer may be formed by application of a coating liquid
formed by dispersing the phthalocyanine crystal according to the
present invention in a solution of an appropriate binder, followed
by drying of the coating liquid, but can also be formed by vacuum
deposition of the phthalocyanine crystal.
[0052] The charge transport layer may be formed by application of a
coating liquid formed by dissolving a charge transporting material
and a binder resin in a solvent, followed by drying of the coating
liquid. Examples of the charge-transporting material may include;
various triarylamine compounds, hydrazone compounds, stilbene
compounds, pyrazoline compounds, oxazole compounds, thiazole
compounds, and triarylmethane compounds.
[0053] Examples of the binder resin for providing the respective
layers may include: polyester, acrylic resin, polyvinylcarbazole,
phenoxy resin, polycarbonate, polyvinyl butyral, polystyrene,
polyvinyl acetate, polysulfone, polyarylate, polyvinylidene
chloride, arylonitrile copolymer and polyvinylbenzal.
[0054] For the formation of the photosensitive layers, various
coating methods may be adopted, inclusive of dipping, spray
coating, spinner coating, bead coating, blade coating and beam
coating.
[0055] A photosensitive layer of a single-layer structure may
preferably have a thickness of 5-40 .mu.m, particularly 10-30
.mu.m. In a laminated photosensitive layer Structure, the charge
generation layer may preferably have a thickness of 0-01-10 .mu.m,
particularly 0.1-3 .mu.m, and the charge transport layer may
preferably have a thickness of 5-40 .mu.m, particularly 10-30
.mu.m.
[0056] The charge-generating material may preferably be contained
in 20-90 wt. %, more preferably 50-80 wt. %, of the charge
generation layer. The charge-transporting material may preferably
be contained in 20-80 wt. %, more preferably 30-70 wt. % of the
charge transport layer. In the case of a single photosensitive
layer, the charge-generating material may preferably contained in
3-30 wt. %, and the charge-transporting material may preferably be
contained in 30-70 wt. %, respectively of the photosensitive
layer.
[0057] The phthalocyanine crystal of the present invention may be
used as such a charge-generating material and can be used in
mixture with another charge-generating material. In the latter
case, the phthalocyanine crystal may preferably occupy at least 50
wt. % of the total charge generating materials.
[0058] The photosensitive layer can be further coated with a
protective layer as desired. Such a protective layer may be formed
in a thickness of preferably 0.05-20 .mu.m by application of a
solution in an appropriate solvent of a resin, such as polyvinyl
butyral, polyester, polycarbonate (polycarbonate Z, modified
polycarbonate, etc.), nylon, polyimide, polyarylate, polyurethane,
styrene-butadiene copolymer, ethylene-acrylic acid copolymer,
styrene-acrylonitrile copolymer, or curable resin precursor,
followed by drying and optional curing. The protective layer can
further contain electroconductive particles of, e.g., metal oxides,
such as tin oxide, an ultraviolet absorber, etc.
[0059] Next, some description will be made on the
electrophotographic apparatus according to the present
invention.
[0060] Referring to FIG. 1, a photosensitive member 1 in the form
of a drum is rotated about an axis 1a at a prescribed peripheral
speed in the direction of the arrow shown inside of the
photosensitive member 1. The peripheral surface of the
photosensitive member 1 is uniformly charged by means of a primary
charger 2 to have a prescribed positive or negative potential. At
an exposure part 3, the photosensitive member 1 is imagewise
exposed to light L (as by slit exposure or laser beam-scanning
exposure) by using an image exposure means (not shown), whereby an
electrostatic latent image is successively formed corresponding to
the exposure pattern on the surface of the photosensitive member 1.
The thus formed electrostatic latent image is developed by using a
developing means 4 to form a toner image. The toner image is
successively transferred to a transfer(-receiving) material 9 which
is supplied from a supply part (not shown) to a position between
the photosensitive member 1 and a transfer charger 5 in synchronism
with the rotation speed of the photosensitive member 1, by means of
a corona transfer charger 5. The transfer material 9 carrying the
toner image thereon is separated from the photosensitive member 1
to be conveyed to a fixing device 8, followed by image fixing to
print out the transfer material 9 as a copy outside the
electrophotographic apparatus. Residual toner particles remaining
on the surface of the photosensitive member 1 after the transfer
operation are removed by a cleaning means 6 to provide a cleaned
surface, and residual charge on the surface of the photosensitive
member 1 is erased by a pre-exposure means 7 to prepare for the
next cycle.
[0061] FIG. 2 shows an electrophotographic apparatus wherein an
electrophotographic photosensitive member 1, a charging means 2 and
a developing means 4 are integrally stored in a container 20 to
form a process cartridge, which is detachably mountable to a main
assembly of the electrophotographic apparatus by the medium of a
guiding means, such as a rail of the main assembly. A cleaning
means 6 may be disposed as shown or not disposed within the
container 20.
[0062] FIGS. 3 and 4 show other embodiments of the
electrophotographic apparatus according to the present invention
including different forms of process cartridges wherein a contact
charging member 10 supplied with a voltage as a charging means is
caused to contact a photosensitive member 1 to charge the
photosensitive member 1. In the apparatus of FIGS. 3 and 4, toner
images on the photosensitive member 1 are transferred onto a
transfer material P also by means of a contact charging member 23.
More specifically, a contact charging member 23 supplied with a
voltage is caused to contact a transfer material, whereby a toner
image on the photosensitive member 1 is transferred onto the
transfer material 9.
[0063] Further, in the apparatus of FIG. 4, at least the
photosensitive member 1 and the contact charging member 10 are
stored within a first container 21 to form a first process
cartridge, and at least the developing means 4 is stored within a
second container 22 to form a second process cartridge; so that the
first and second process cartridges are detachably mountable to the
main assembly of the electrophotographic apparatus. A cleaning
means 6 may be disposed as shown or not disposed within the
container 21. In the case where the electrophotographic apparatus
constitutes a copying machine or a printer, the exposure light L
may be provided as reflected light or transmitted light from an
original, or alternatively provided as image-carrying illumination
light formed by reading an original by a sensor, converting the
read data into signals and driving a laser beam scanner, an LED
array or a liquid crystal shutter array.
[0064] Hereinbelow, the present invention will be described more
specifically with reference to Examples and Comparative Examples
wherein "parts" and "%" used for describing a relative amount of a
component or a material are by weight unless specifically noted
otherwise.
SYNTHESIS EXAMPLE 1
[0065] 72 parts of o-phthalonitrile, 25 parts of gallium
trichloride and 350 parts of quinoline were reacted with each other
for 4 hours at 200.degree. C. in a nitrogen atmosphere, followed by
filtration at 130.degree. C. to recover the product. The product
was washed in dispersion within N,N-dimethylformamide at
140.degree. C. for 2 hours, followed by filtration, washing with
methanol and drying to obtain 32 parts (yield: 38.0%) of
chlorogallium phthalocyanine crystal. The chlorogallium
phthalocyanine crystal (represented by C.sub.32H.sub.16ClGaN.sub.8)
exhibited a powdery X-ray diffraction pattern as shown in FIG. 5
and the following results of elementary analysis.
1 Element Calculated (%) Measured (%) C 62.2 62.4 H 2.6 2.6 N 18.1
18.2 Cl 5.7 5.9
SYNTHESIS EXAMPLE 2
[0066] 15 parts of the chlorogallium phthalocyanine prepared in
Synthesis Example 1 was dissolved in 300 parts of conc. sulfuric
acid cooled at 15.degree. C., and the resultant solution was added
dropwise into 2000 parts of iced water under stirring to cause
re-precipitation, followed by filtration. The precipitate was
washed in dispersion first within 2% ammonia water and then four
times within deionized water, and then dried in vacuum at
40.degree. C. to obtain 13 parts of hydroxygallium phthalocyanine
crystal. The hydroxygallium phthalocyanine crystal (represented by
C.sub.32H.sub.17GaN.sub.8O) exhibited a powdery X-ray diffraction
pattern as shown in FIG. 6 and the following results of elementary
analysis.
2 Element Calculated (%) Measured (%) C 64.1 63..2 H 2.9 3.2 N 18.7
18.3 Cl 0.0 0.0
EXAMPLE 1
[0067] 15 parts of the chlorogallium phthalocyanine prepared in
Synthesis Example 1 was dissolved in a mixture of 300 parts of
conc. sulfuric acid and 1.5 parts (corresponding to 10% of the
chlorogallium phthalocyanine) of .alpha.-chloronaphthalene (purity
>85%, available from Tokyo Kasei Kogyo K.K.) cooled at
15.degree. C., and the resultant solution was added dropwise into
2000 parts of iced water under stirring to cause re-precipitation,
followed by filtration. The precipitate was washed in dispersion
first within 2% ammonia water and then four times within deionized
water, and then dried in vacuum at 40.degree. C. to obtain 13 parts
of hydroxygallium phthalocyanine crystal, which exhibited a powdery
X-ray diffraction pattern as shown in FIG. 7.
EXAMPLE 2
[0068] 15 parts of the chlorogallium phthalocyanine prepared in
Synthesis Example 1 was dissolved in 300 parts of conc. sulfuric
acid cooled at 15.degree. C., and the resultant solution was added
dropwise into a mixture of 2000 parts of iced water and 15 parts
(corresponding to 100% of the chlorogallium phthalocyanine) under
stirring to cause re-precipitation, followed by filtration. The
precipitate was washed in dispersion first within 2% ammonia water
and then four times within deionized water, and then dried in
vacuum at 40.degree. C. to obtain 13 parts of hydroxygallium
phthalocyanine crystal, which exhibited a powdery X-ray diffraction
pattern as shown in FIG. 8.
EXAMPLE 3
[0069] 5 parts of the hydroxygallium phthalocyanine prepared in
Example 1 and 95 parts of N,N-dimethylformamide were milled
together with 150 parts of 1 mm-dia. glass beads for 20 hours at
room temperature (24.degree. C.) in a ball mill. The solid matter
was recovered from the resultant dispersion, sufficiently washed
with tetrahydrofuran, and dried, to obtain 4.5 parts of
hydroxygallium phthalocyanine crystal. The hydroxygallium
phthalocyanine crystal (as represented by
C.sub.32H.sub.17GaN.sub.8O for convenience) exhibited an X-ray
diffraction pattern as shown in FIG. 9 and the following results of
elementary analysis. The measured value of Cl content indicated
that 6845 ppm of .alpha.-chloronaphthalene was contained in the
crystal.
3 Element Calculated (%) Measured (%) C 64.1 63.5 H 2.9 3.0 N 18.7
18.3 Cl 0.0 0.150
EXAMPLE 4
[0070] The hydroxygallium phthalocyanine prepared in Example 2 was
subjected to milling and post-treatments similarly as in Example 3.
The recovered hydroxygallium phthalocyanine crystal (as represented
by C.sub.32H.sub.17GaN.sub.8O) exhibited an X-ray diffraction
pattern as shown in FIG. 10 and the following results of elementary
analysis. The measured value of Cl content indicated that 7301 ppm
of .alpha.-chloronaphthalene was contained in the crystal.
4 Element Calculated (%) Measured (%) C 64.1 63.9 H 2.9 3.0 N 18.7
18.4 Cl 0.0 0.160
EXAMPLE 5
[0071] 5 parts of the hydroxygallium phthalocyanine prepared in
Synthesis Example 2, 95 parts of N,N-dimethylformamide and 0.5 part
of .alpha.-chloronaphthalene were milled together with 150 parts of
1 mm-dia. glass beads for 20 hours at room temperature (24.degree.
C.) in a ball mill. The solid matter was recovered from the
resultant dispersion, sufficiently washed with tetrahydrofuran, and
dried, to obtain 4.5 parts of hydroxygallium phthalocyanine
crystal. The hydroxygallium phthalocyanine crystal (as represented
by C.sub.32H.sub.17GaN.sub.8O) exhibited an X-ray diffraction
pattern as shown in FIG. 11 and the following results of elementary
analysis. The measured value of Cl content indicated that 3057 ppm
of .alpha.-chloronaphthalene was contained in the crystal.
5 Element Calculated (%) Measured (%) C 64.1 63.4 H 2.9 3.0 N 18.7
18.6 Cl 0.0 0.067
EXAMPLE 6
[0072] 5 parts of the hydroxygallium phthalocyanine prepared in
Synthesis Example 2, 95 parts of N,N-dimethylformamide and 5 parts
of .alpha.-chloronaphthalene were milled together with 150 parts of
1 mm-dia. glass beads for 20 hours at room temperature (24.degree.
C.) in a ball mill The solid matter was recovered from the
resultant dispersion, sufficiently washed with tetrahydrofuran, and
dried, to obtain 4.5 parts of hydroxygallium phthalocyanine
crystal. The hydroxygallium phthalocyanine crystal (as represented
by C.sub.32H.sub.17GaN.sub.8O) exhibited an X-ray diffraction
pattern as shown in FIG. 12 and the following results of elementary
analysis. The measured value of Cl content indicated that 7073 ppm
of .alpha.-chloronaphthalene was contained in the crystal. As a
result of TG-GC/MS (thermogravimetry-gas chromatography/mass
spectrometry) analysis in the range of 25.degree. C.-500.degree. C.
(by using a TG-MS simultaneous measurement apparatus, available
from K.K. Shimadzu Seisakosho), the crystal exhibited 6474 ppm of
.alpha.-chloronaphthalene, 155 ppm of naphthalene, and 2.03% of
N,N-dimethylformamide. The .alpha.-chloronaphthalene content was in
good agreement with that calculated from the chlorine (Cl)
content.
6 Element Calculated (%) Measured (%) C 54.1 63.4 H 2.9 3.0 N 18.7
18.6 Cl 0.0 0.155
EXAMPLE 7
[0073] 5 parts of the hydroxygallium phthalocyanine prepared in
Synthesis Example 2, 95 parts of N,N-dimethylformamide and 0.5 part
of naphthalene were milled together with 150 parts of 1 mm-dia.
glass beads for 20 hours at room temperature (24.degree. C.) in a
ball mill. The solid matter was recovered from the resultant
dispersion, sufficiently washed with tetrahydrofuran, and dried, to
obtain 4.5 parts of hydroxygallium phthalocyanine crystal. The
hydroxygallium phthalocyanine crystal (as represented by
C.sub.32H.sub.17GaN.sub.8O) exhibited an X-ray diffraction pattern
as shown in FIG. 13 and the following results of elementary
analysis. Further, as a result of the TG-GC/MS analysis
(25-500.degree. C.), the crystal exhibited 1500 ppm of naphthalene
and 2.00% of N,N-dimethylformamide.
7 Element Calculated (%) Measured (%) C 64.1 63.4 H 2.9 3.0 N 18.7
18.7 Cl 0.0 0.0
EXAMPLE 8
[0074] 5 parts of the hydroxygallium phthalocyanine prepared in
Synthesis Example 2, 95 parts of N,N-dimethylformamide and 5 parts
of naphthalene were milled together with 150 parts of 1 mm-dia.
glass beads for 20 hours at room temperature (24.degree. C.) in a
ball mill. The solid matter was recovered from the resultant
dispersion, sufficiently washed with tetrahydrofuran, and dried, to
obtain 4.5 parts of hydroxygallium phthalocyanine crystal. The
hydroxygallium phthalocyanine crystal (as represented by
C.sub.32H.sub.17GaN.sub.8O) exhibited an X-ray diffraction pattern
as shown in FIG. 14 and the following results of elementary
analysis. Further, as a result of the TG-GC/MS analysis
(25-500.degree. C.), the crystal exhibited 2840 ppm of naphthalene
and 2.00% of N,N-dimethylformamide.
8 Element Calculated (%) Measured (%) C 64.1 63.4 H 2.9 3.0 N 18.7
18.7 Cl 0.0 0.0
COMPARATIVE EXAMPLE 1
[0075] The hydroxygallium phthalocyanine prepared in Synthesis
Example 1 was subjected to milling and post-treatments similarly as
in Example 3. The recovered hydroxygallium phthalocyanine crystal
(represented by C.sub.32H.sub.17GaN.sub.8O) exhibited an X-ray
diffraction pattern as shown in FIG. 15 and the following results
of elementary analysis. Further, as a result of the TG-GC/MS
analysis (25-500.degree. C.), the crystal exhibited 3.38% of
N,N-dimethylformamide.
9 Element Calculated (%) Measured (%) C 64.1 63.6 H 2.9 3.0 N 18.7
18.9 Cl 0.0 0.0
EXAMPLE 9
[0076] 50 parts of titanium oxide powder coated with tin oxide
containing 10% of antimony oxide, 25 parts of resol-type phenolic
resin, 20 parts of methyl cellosolve, 5 parts of methanol and 0.002
part of silicone oil (polydimethylsiloxane-polyoxyalkylene
copolymer, average molecular weight=3000), were dispersed for 2
hours in a sand mill containing 1 mm-dia. glass beads, to prepare
an electroconductive paint. An aluminum cylinder (of 30 mm in
diameter) was coated by dipping within the above-prepared
electroconductive paint, followed by drying at 140.degree. C. for
30 min. to form a 15 .mu.m-thick electroconductive layer.
[0077] The aluminum cylinder was further coated by dipping within a
solution of 5 parts of 6-66-610-12 quaternary polyamide copolymer
resin in a solvent mixture of 70 parts of methanol and 25 parts of
butanol, followed by drying, to form a 0.7 .mu.m-thick undercoating
layer.
[0078] Separately, 2.5 part of the gallium phthalocyanine crystal
prepared in Example 3 and 1 part of polyvinyl butyral resin ("S-LEC
BX-1", available from Sekisui Kagaku Kogyo K.K.), were added to 70
parts of cyclohexanone, and the mixture was subjected to 3 hours of
dispersion in a sand mill containing 1 media. glass beads and then
diluted with 100 parts of ethyl acetate to obtain a paint. The
paint was applied by dipping onto the undercoating layer and dried
at 120.degree. C. for 10 min. to form a 0.2 .mu.m-thick charge
generation layer.
[0079] Then, 10 parts of a charge-transporting material of the
following structural formula: 1
[0080] and 10 pats of polycarbonate resin ("IUPILON Z-200",
available from Mitsubishi Gas Kagaku K.K.) were dissolved in 60
parts of monochlorobenzene to form a coating solution, which was
then applied by dipping on the above-formed charge generation layer
on the aluminum cylinder and dried at 120.degree. C. for 60 min, to
form a 17 .mu.m-thick charge transport layer, thus providing an
electrophotographic photosensitive member.
EXAMPLES 10-14
[0081] Five electrophotographic photosensitive members were
prepared in the same manner as in Example 9 except that the gallium
phthalocyanine crystal of. Example 3 was replaced by the gallium
phthalocyanine crystals of Examples 4-8, respectively.
COMPARATIVE EXAMPLE 2
[0082] A comparative electrophotographic photosensitive member was
prepared in the same manner as in Example 9 except that the gallium
phthalocyanine crystal of Example 3 was replaced by the gallium
phthalocyanine crystal of Comparative Example 1.
[0083] Each of the electrophotographic photosensitive members
prepared in Examples 9-14 and Comparative Example 2 was evaluated
with respect to sensitivity and image defects of black spots and
fog by incorporating it into a process cartridge of a commercially
available laser beam printer ("LBP-1760", mfd. by Canon K.K.) and
incorporating the process cartridge in the printer after remodeling
for allowing light quantity change. The sensitivity measurement was
performed by setting the charging condition so as to provide a
dark-part potential of -600 volts and measuring a light quantity
required for lowering the potential to -140 volts.
[0084] Then, the photosensitive member incorporated in the printer
was subjected to evaluation of images formed at an initial stage in
a high temperature/high humidity environment of 35.degree.
C./80%RH. The image evaluation was evaluated by the state of
occurrence of image defects inclusive of black spots and fog due to
charging failure according to the following standards.
[0085] A: No black spots or fog observed with eyes.
[0086] C: Black spots or fog observed with eyes.
[0087] The results of the evaluation are inclusively shown in the
following Table 1.
10TABLE 1 Example Sensitivity (.mu.J/cm.sup.2) Image evaluation 9
0.36 A 10 0.48 A 11 0.34 A 12 0.33 A 13 0.38 A 14 0.34 A Comp. 2
0.56 C
[0088] Each of the photosensitive members prepared in Examples 11,
12 and 14, and Comparative Example 2 (identical to those evaluated
in the above test but in separately as-produced state) was
incorporated in a process cartridge and then in a commercially
available printer ("LBP-1760") (without the above remodeling) for
measurement of a light-part potential (VI) in an initial stage, a
continuous image formation on 5000 sheets and measurement of a
change in light-part potential (.DELTA..vertline.V1.vert- line.)
after the continuous image formation. The results are inclusively
shown in Table 2 below. Incidentally,
.DELTA..vertline.V1.vertline.=+10 volts means an increase in
absolute value of the light-part potential (e.g., a change rom
V1=-180 volts to V1=-190 volts).
11TABLE 2 Example Initial Vl (volts) .DELTA..vertline.Vl.vertline.
(volts) 11 -180 +10 12 -170 +5 14 -180 +10 Comp. 2 -270 +40
[0089] As described above, according to the present invention, a
phthalocyanine crystal formed by doping a phthalocyanine compound
with a minor mount of a substituted or unsubstituted condensed
polycyclic hydrocarbon compound is provided, and by incorporating
the phthalocyanine crystal in a photosensitive layer, it is
possible to provide an electrophotographic photosensitive member
exhibiting a high sensitivity in a semiconductor wavelength region
and a potential stability in repetitive use, and further providing
images with less image defects, particularly less black spots in a
reversal development scheme.
* * * * *