U.S. patent application number 11/598463 was filed with the patent office on 2007-05-17 for titanyl phthalocyanin crystal, method for preparing the same and electrophotographic photoconductor.
Invention is credited to Jun Azuma, Junichiro Otsubo.
Application Number | 20070111123 11/598463 |
Document ID | / |
Family ID | 37513840 |
Filed Date | 2007-05-17 |
United States Patent
Application |
20070111123 |
Kind Code |
A1 |
Otsubo; Junichiro ; et
al. |
May 17, 2007 |
Titanyl phthalocyanin crystal, method for preparing the same and
electrophotographic photoconductor
Abstract
According to the present invention, a titanyl phthalocyanin
crystal excellent in storage stability in organic solvents, a
method for preparing the same and an electrophotographic
photoconductor using the same are provided. In the titanyl
phthalocyanin crystal, the method for preparing such a titanyl
phthalocyanin crystal and the electrophotographic photoconductor
using the same, the titanyl phthalocyanin crystal is characterized
by having the maximum peak at a Bragg angle
2.theta..+-.0.2.degree.=27.2.degree. in a CuK.alpha. characteristic
X-ray diffraction spectrum and one peak within the range of 270 to
400.degree. C. other than a peak accompanied by the vaporization of
adsorbed water in a differential scanning calorimetric
analysis.
Inventors: |
Otsubo; Junichiro; (Osaka,
JP) ; Azuma; Jun; (Osaka, JP) |
Correspondence
Address: |
Arthur G. Schaier, Carmody & Torrance LLP
P.O. Box 1110
50 Leavenworth Street
Waterbury
CT
06721-1110
US
|
Family ID: |
37513840 |
Appl. No.: |
11/598463 |
Filed: |
November 13, 2006 |
Current U.S.
Class: |
430/78 ; 540/135;
540/136; 540/140 |
Current CPC
Class: |
G03G 5/0603 20130101;
G03G 5/0675 20130101; C09B 67/0019 20130101; G03G 5/0616 20130101;
C09B 67/0026 20130101; G03G 5/0696 20130101; C09B 67/0016 20130101;
G03G 5/0677 20130101; G03G 5/0614 20130101 |
Class at
Publication: |
430/078 ;
540/140; 540/136; 540/135 |
International
Class: |
G03G 5/06 20060101
G03G005/06; C07D 487/22 20060101 C07D487/22 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 16, 2005 |
JP |
2005-331653 |
Claims
1. A titanyl phthalocyanin crystal having the maximum peak at a
Bragg angle 2.theta..+-.0.2.degree.=27.2.degree. in a CuK.alpha.
characteristic X-ray diffraction spectrum and one peak within the
range of 270 to 400.degree. C. other than a peak accompanied by the
vaporization of adsorbed water in a differential scanning
calorimetric analysis.
2. The titanyl phthalocyanin crystal according to claim 1, wherein
the titanyl phthalocyanin crystal has no peak at a Bragg angle
2.theta..+-.0.2.degree.=26.2.degree. in the CuK.alpha.
characteristic X-ray diffraction spectrum.
3. The titanyl phthalocyanin crystal according to claim 1, wherein
the titanyl phthalocyanin crystal recovered after being immersing
for 7 days in an organic solvent has at least the maximum peak at a
Bragg angle 2.degree..+-.0.2.degree.=27.2.degree. and no peak at
26.2.degree. in the CuK.alpha. characteristic X-ray diffraction
spectrum.
4. The titanyl phthalocyanin crystal according to claim 3, wherein
a organic solvent is at least one selected from the group
consisting of tetrahydrofuran, dichloromethane, toluene,
1,4-dioxane and 1-methoxy-2-propanol.
5. The titanyl phthalocyanin crystal according to claim 1, wherein
the structure of titanyl phthalocyanin compounds is represented by
the following general formula (1). ##STR15## (In the general
formula (1), X.sup.1 to X.sup.4 are the same or different
substituents, each independently represents a hydrogen atom, a
halogen atom, a substituted or an unsubstituted alkyl group, a
substituted or an unsubstituted alkoxy group, a substituted or an
unsubstituted cyano group or a substituted or an unsubstituted
nitro group, respectively, the repeat number "a", "b", "c" and "d"
represent an integer of 1 to 4, respectively and may be same or
different, respectively.)
6. A method for preparing a titanyl phthalocyanin crystal having
the maximum peak at a Bragg angle
2.theta..+-.0.2.degree.=27.2.degree. in a CuK.alpha. characteristic
X-ray diffraction spectrum and one peak within the range of 270 to
400.degree. C. other than a peak accompanied by the vaporization of
adsorbed water in a differential scanning calorimetric analysis and
comprising the following processes (a) and (b); (a) a process for
preparing a titanyl phthalocyanin compound by adding a titanium
alkoxide or titanium tetrachloride at a value within the range of
0.40 to 0.53 mole with respect to 1 mole of o-phthalonitrile or its
derivative or 1,3-diiminoisoindoline or its derivative and adding a
urea compound at a value within the range of 0.1 to 0.95 mole with
respect to 1 mole of o-phthalonitrile or its derivative or
1,3-diiminoisoindoline or its derivative to react the compounds,
(b) a process for preparing a titanyl phthalocyanin crystal by
performing an acid treatment on the titanyl phthalocyanin compound
prepared in the process (a).
7. The method for preparing the titanyl phthalocyanin crystal
according to claim 6, wherein the urea compound is at least one
compound selected from the group consisting of urea, thiourea,
o-methylisourea sulfate, o-methylisourea carbonate and
o-methylisourea hydrochloride.
8. The method for preparing the titanyl phthalocyanin crystal
according to claim 6, wherein the reaction temperature in the
process (a) is set to a value of 150.degree. C. or above.
9. The method for preparing the titanyl phthalocyanin crystal
according to claims 6, wherein the process (a) is performed in a
nitrogen-containing compound with a boiling point of 180.degree. C.
or above.
10. An electrophotographic photoconductor having a photosensitive
layer is provided on a conductive substrate, wherein the
photosensitive layer contains the titanyl phthalocyanin crystal
having the maximum peak at a Bragg angle
2.theta..+-.0.2.degree.=27.2.degree. in the CuK.alpha.
characteristic X-ray diffraction spectrum and one peak within the
range of 270 to 400.degree. C. other than a peak accompanied by the
vaporization of adsorbed water in the differential scanning
calorimetric analysis, within the range of 0.1 to 50 part by weight
with respect to 100 part by weight of a binder resin forming the
photosensitive layer.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a titanyl phthalocyanin
crystal prepared from a titanyl phthalocyanin compound, the method
for preparing the same and an electrophotographic photoconductor
using the same. Particularly, the present invention relates to a
titanyl phthalocyanin crystal excellent in the storage stability in
organic solvents, the method for preparing the same and an
electrophotographic photoconductor using the same.
[0003] 2. Related Art
[0004] Generally, organic photoconductors have been frequently and
recently used in electrophotographic photoconductors applied in
electrophotographic devices such as a copy machine and a laser
printer, etc. upon such requirements as low cost and low
environment polluting property, etc. Phthalocyanin pigments that
are sensitive to a light of infrared to near-infrared wavelengths
irradiated from a semiconductor laser or an infrared LED, etc. have
been widely used as charge-generating agent used in such organic
photoconductors.
[0005] It has been known that metal-free phthalocyanin compounds,
copper phthalocyanin compounds, titanyl phthalocyanin compounds,
etc. exist in such phthalocyanin pigments depending on a chemical
structure thereof, and various crystal types can be obtained due to
different preparation conditions for each phthalocyanin
compound.
[0006] Thus, it has been known that when a photoconductor using a
titanyl phthalocyanin with a Y-type crystal structure as a
charge-generating agent is constituted in the existence of many
types of phthalocyanin compound crystals having different crystal
types, electric characteristics in the photoconductor is improved
as compared with a case of using tithanylphthalocyanines of other
crystal types.
[0007] For example, there has been disclosed a method for preparing
a Y-type crystal prepared by reacting a titanium compound and an
organic compound that is a titanyl phthalocyanin having the maximum
peak at a Bragg angle (2.theta..+-.0.2.degree.)=27.3.degree. for a
CuK.alpha. line in an X-ray diffraction spectrum and can form a
phthalocyanin ring under conditions of 130.degree. C. and about 4
hrs in dialkyl-aminoalcohol added with urea or ammonia (e.g.,
Patent document 1).
[0008] There has also been disclosed a method for preparing a
titanium phthalocyanin compound of Y-type crystal prepared by
directly reacting o-phthalonitrile and titanium tetrabutoxide
without using a urea compound under conditions of 215.degree. C.
and about 2 hrs (e.g., Patent documents 2 and 3).
[0009] More specifically, there has been disclosed a method for
preparing a titanyl phthalocyanin crystal having a peak within a
predetermined range in the CuK.alpha. characteristic X-ray
diffraction spectrum and no peak within the range of 50 to
400.degree. C. in the differential scanning calorimetric
analysis.
[0010] [Patent document 1] JPH8-176456A (examples)
[0011] [Patent document 2] JP3463032 (claims)
[0012] [Patent document 3] JP2004-145284A (claims)
SUMMARY OF THE INVENTION
Problems to be Solved
[0013] However, according to Patent document 1, there has been
found the problem that the prepared titanyl phthalocyanin crystal
having a Y-type structure had a tendency to cause crystal
transition to a .beta.-type or .alpha.-type crystal in a coating
solution for a photosensitive layer. Therefore, there has been
found the problem that the coating solution for the photosensitive
layer is insufficient in storage stability, and thereby a
photosensitive layer having good electric characteristics cannot be
formed.
[0014] On the other hand, when a titanyl phthalocyanin crystal
described in Patent document 2 or Patent document 3 was used, the
crystal transition from the Y-type crystal in the coating solution
for the photosensitive layer to a .beta.-type crystal poor in
sensitivity characteristic could be inhibited, but there found such
a case that an image forming device using a photoconductor with a
titanyl Phthalo-cyanin crystal described in Patent document 2 or
Patent document 3 caused fogging and did not give a good image
under a high temperature condition and a high humidity
condition.
[0015] Therefore, as a result of intensive investigation for
solving above-mentioned problems, present inventors discovered that
the storage stability of a titanyl phthalocyanin crystal in organic
solvents was enhanced and a good image was simultaneously obtained
by controlling the crystal so as to have a peak at a prescribed
Bragg angle in the CuK.alpha. characteristic X-ray diffraction
spectrum, and at the same time, have one peak within a
predetermined temperature range in the differential scanning
calorimetric analysis.
[0016] That is, the object of present invention is to provide a
titanyl phthalocyanin crystal excellent in storage stability in
organic solvents, a method for preparing such a titanyl
phthalocyanin crystal and an electrophotographic photoconductor
using the same.
The Means for Solving the Problems
[0017] The present invention enables to provide a titanyl
phthalocyanin crystal characterized by having the maximum peak at a
Bragg angle 2.theta..+-.0.2.degree.=27.2.degree. in a CuK.alpha.
characteristic X-ray diffraction spectrum and one peak within the
range of 270 to 400.degree. C. other than a peak accompanied by the
vaporization of adsorbed water in a differential scanning
calorimetric analysis to solve the above-mentioned problems.
[0018] That is, if the crystal is the titanyl phthalocyanin crystal
having such an optical characteristic and thermal characteristic,
it may effectively inhibit the crystal transition to the
.alpha.-type crystal or .beta.-type crystal even if it is immersed
in an organic solvent for a long time, e.g., 7 days or longer.
Accordingly, the present invention enables to obtain a coating
solution for a photosensitive layer more excellent in storage
stability and stably constitute an electrophotographic
photoreceptor excellent in electric characteristics and image
characteristics by using the same.
[0019] It is preferable that the titanyl phthalocyanin crystal of
present invention has no peak at a Bragg angle
2.theta..+-.0.2.degree.=26.2.degree. in the CuK.alpha.
characteristic X-ray diffraction spectrum when the crystal is
prepared.
[0020] Due to such a composition, the transition of titanyl
phthalocyanin crystal to the .beta.-type may be further controlled
for a long time and the storage stability of titanyl phthalocyanin
crystal in organic solvents may be further improved.
[0021] It is preferable that the titanyl phthalocyanin crystal of
present invention recovered after being immersed for 7 days in an
organic solvent has at least the maximum peak at a Bragg angle
2.theta..+-.0.2.degree.=27.2.degree. and no peak at 26.2.degree. in
the CuK.alpha. characteristic X-ray diffraction spectrum when the
crystal is prepared.
[0022] Due to such a composition, the transition of titanyl
phthalocyanin crystal in organic solvents may be further reliably
controlled and consequently whether the titanyl phthalocyanin
crystal is excellent in storage stability may be determined
quantitatively.
[0023] It is preferable that the organic solvent is at least one
selected from the group consisting of tetrahydrofuran,
dichloromethane, toluene, 1,4-dioxane and 1-methoxy-2-propanol when
the titanyl Phthalocyanin crystal of present invention is
prepared.
[0024] Due to such a composition, the stability of the specific
titanyl phthalocyanin crystal may be further reliably determined
when such organic solvents are used as organic solvents for the
coating solution for the photosensitive layer.
[0025] It is preferable that the structure of titanyl phthalocyanin
compound prepared form the titanyl phthalocyanin crystal of present
invention is represented by the following general formula when the
crystal is prepared.
[0026] Due to such a composition, the storage stability of titanyl
phthalocyanin crystal of the specific structure in organic solvents
may be further improved. ##STR1## (In the general formula (1),
X.sup.1 to X.sup.4 are the same or different substituents, each
independently represents a hydrogen atom, a halogen atom, a
substituted or an unsubstituted alkyl group, a substituted or an
unsubstituted alkoxy group, a substituted or an unsubstituted cyano
group or a substituted or an unsubstituted nitro group,
respectively. The repeat numbers "a", "b", "c" and "d" represent an
integer of 1 to 4, respectively and may be same or different,
respectively.)
[0027] Another aspect of the present invention is a method for
preparing titanyl phthalocyanin crystal having the maximum peak at
a Bragg angle 2.theta..+-.0.2.degree.=27.2.degree. in the
CuK.alpha. characteristic X-ray diffraction spectrum and one peak
within the range of 270 to 400.degree. C. other than a peak
accompanied by the vaporization of adsorbed water in the
differential scanning calorimetric analysis. Then, it is a method
for preparing characterized by comprising the following processes
(a) and (b);
[0028] (a) a process for preparing a titanyl phthalocyanin compound
by adding a titanium alkoxide or titanium tetrachloride at a value
within the range of 0.40 to 0.53 mole with respect to 1 mole of
o-phthalonitrile or its derivative or 1,3-diiminoisoindoline or its
derivative and adding a urea compound at a value within the range
of 0.1 to 0.95 mole with respect to 1 mole of o-phthalonitrile or
its derivative or 1,3-diiminoisoindoline or its derivative to react
the compounds,
[0029] (b) a process for preparing a titanyl phthalocyanin crystal
by performing an acid treatment on the titanyl phthalocyanin
compound prepared in the process (a).
[0030] That is, ammonia generated by reacting raw materials and a
urea compound facilitates forming a complex compound with a
titanium alkoxide more efficiently by preparing the titanyl
phthalocyanin crystal by the method comprising the above processes
(a) to (b). Therefore, such a complex compound enables to prepare
the titanyl phthalocyanin crystal that is hard to change its
crystal type and excellent in storage stability even in organic
solvents by further accelerating the reaction of raw materials.
[0031] It is preferable that the urea compound is at least one
compound selected from the group consisting of urea, thiourea,
o-methylisourea sulfate, o-methylisourea carbonate and
o-methylisourea hydrochloride in the above-mentioned process (a)
when the method for preparing titanyl phthalocyanin crystal of the
present invention is performed.
[0032] Due to such an embodiment, the titanyl phthalocyanin crystal
that is hard to cause the crystal transition to the .alpha.-type
crystal and .beta.-type crystal may be efficiently obtained by
interaction of such urea compounds and the raw materials even if
the crystal is immersed in an organic solvent for a long time,
e.g., 7 days or longer. As a result, the titanyl phthalocyanin
crystal with improved storage stability may be prepare at a lower
cost.
[0033] It is preferable that the reaction temperature in the
process (a) is set to a value of 150.degree. C. or above when the
method for preparing titanyl phthalocyanin crystal of present
invention is performed.
[0034] Due to such an embodiment, products generated as a vapor
from the reaction system may be removed to the outside, and thereby
allow to react a titanium alkoxide or titanium tetrachloride as raw
material and a urea compound.
[0035] It is preferable that the process (a) is performed in a
nitrogen-containing compound with a boiling point of 180.degree. C.
or above when the method for preparing titanyl phthalocyanin
crystal of the present invention is performed.
[0036] Due to such an embodiment, ammonia generated by a reaction
of a urea compound and a titanium alkoxide or titanium
tetrachloride allows to form a complex with the titanium alkoxide
or titanium tetrachloride. As a result, the reaction fully
proceeds, and a titanyl Phthalocyanin crystal that is hard in
crystal transition in an organic solvent may be efficiently
prepared in a short time.
[0037] Still more, another aspect of the present invention is an
electrophotographic photoconductor characterized by the fact that a
photosensitive layer is provided on a conductive substrate, and the
photosensitive layer contains the titanyl phthalocyanin crystal
having the maximum peak at a Bragg angle
2.theta..+-.0.2.degree.=27.2.degree. in the CuK.alpha.
characteristic X-ray diffraction spectrum and one peak within the
range of 270 to 400.degree. C. other than a peak accompanied by the
vaporization of adsorbed water in the differential scanning
calorimetric analysis within the range of 0.1 to 50 part by weight
with respect to 100 part by weight of a binder resin forming the
photosensitive layer.
[0038] That is, an electrophotographic photoconductor having good
electric characteristics and image characteristics may be stably
obtained by using the titanyl phthalocyanin crystal as a charge
generating agent having little crystal transition and excellent
storage stability even if it is immersed in an organic solvent for
a long time.
[0039] It is preferable that a single layer photosensitive layer
containing at least either hole transfer agent or electron transfer
agent is used as the composition of a photosensitive layer, and it
is also preferable that a single layer photosensitive layer
containing both transfer agent and electron transfer agent is used
as the composition of a photosensitive layer. It is also preferable
that a laminated layer constituted by containing a charge
generating layer and a charge transfer layer containing either hole
transfer agent or electron transfer agent is used as the
composition of a photosensitive layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] FIGS. 1 (a) to (c) are a schematic view for illustrating the
composition of a single layer type photoconductor.
[0041] FIGS. 2 (a) to (c) are a schematic view for illustrating the
composition of a laminated layer type photoconductor.
[0042] FIG. 3 is a spectrum for showing a CuK.alpha. characteristic
X-ray diffraction of a titanyl phthalocyanin crystal (after stored
for 7 days in tetrahydrofuran) used in Example 1 (Examples 2 to 21
and 64 to 70).
[0043] FIG. 4 is a chart for showing a differential scanning
calorimetric analysis of a titanyl phthalocyanin crystal used in
Example 1 (Examples 2 to 21 and 64 to 70).
[0044] FIG. 5 is a spectrum for showing a CuK.alpha. characteristic
X-ray diffraction of a titanyl phthalocyanin crystal (after stored
for 7 days in tetrahydrofuran) used in Example 22 (Examples 23 to
42 and 71 to 77).
[0045] FIG. 6 is a chart for showing a differential scanning
calorimetric analysis of a titanyl phthalocyanin crystal used in
Example 22 (Examples 23 to 42 and 71 to 77).
[0046] FIG. 7 is a spectrum for showing a CuK.alpha. characteristic
X-ray diffraction of a titanyl phthalocyanin crystal (after stored
for 7 days in tetrahydrofuran) used in Example 43 (Examples 44 to
63 and 78 to 84).
[0047] FIG. 8 is a chart for showing a differential scanning
calorimetric analysis of a titanyl phthalocyanin crystal used in 43
(Examples 44 to 63 and 78 to 84).
[0048] FIG. 9 is a spectrum for showing a CuK.alpha. characteristic
X-ray diffraction of a titanyl phthalocyanin crystal (after stored
for 7 days in tetrahydrofuran) used in Comparative Example 1
(Comparative Examples 2 to 21 and 106 to 112).
[0049] FIG. 10 is a chart for showing a differential scanning
calorimetric analysis of a titanyl phthalocyanin crystal used in
Comparative Example 1 (Comparative Examples 2 to 21 and 106 to
112).
[0050] FIG. 11 is a spectrum for showing a CuK.alpha.
characteristic X-ray diffraction of a titanyl phthalocyanin crystal
(after stored for 7 days in tetrahydrofuran) used in Comparative
Example 22 (Comparative Examples 23 to 42 and 113 to 119).
[0051] FIG. 12 is a chart for showing a differential scanning
calorimetric analysis of a titanyl phthalocyanin crystal used in
Comparative Example 22 (Comparative Examples 23 to 42 and 113 to
119).
[0052] FIG. 13 is a spectrum for showing a CuK.alpha.
characteristic X-ray diffraction of a titanyl phthalocyanin crystal
(after stored for 7 days in tetrahydrofuran) used in Comparative
Example 43 (Comparative Examples 44 to 63 and 120 to 126).
[0053] FIG. 14 is a chart for showing a differential scanning
calorimetric analysis of a titanyl phthalocyanin crystal used in
Comparative Example 43 (Comparative Examples 44 to 63 and 120 to
126).
[0054] FIG. 15 is a spectrum for showing a CuK.alpha.
characteristic X-ray diffraction of a titanyl phthalocyanin crystal
(after stored for 7 days in tetrahydrofuran) used in Comparative
Example 64 (Comparative Examples 65 to 84 and 127 to 133).
[0055] FIG. 16 is a chart for showing a differential scanning
calorimetric analysis of a titanyl phthalocyanin crystal used in
Comparative Example 64 (Comparative Examples 65 to 84 and 127 to
133).
[0056] FIG. 17 is a spectrum for showing a CuK.alpha.
characteristic X-ray diffraction of a titanyl phthalocyanin crystal
(after stored for 7 days in tetrahydrofuran) used in Comparative
Example 85 (Comparative Examples 86 to 105 and 134 to 140).
[0057] FIG. 18 is a chart for showing a differential scanning
calorimetric analysis of a titanyl phthalocyanin crystal used in
Comparative Example 85 (Comparative Examples 86 to 105 and 134 to
140).
DETAILED DESCRIPTION OF THE INVENTION
First Embodiment
[0058] First Embodiment of the present invention is a titanyl
phthalocyanin crystal characterized by having the maximum peak at a
Bragg angle 2.theta..+-.0.2.degree.=27.2.degree. in the CuK.alpha.
characteristic X-ray diffraction spectrum and one peak within the
range of 270 to 400.degree. C. other than a peak accompanied by the
vaporization of adsorbed water in the differential scanning
calorimetric analysis. The titanyl phthalocyanin crystal of First
Embodiment is described hereinafter by dividing it into
components.
1. Optical Characteristics and Thermal Characteristics
(1) Optical Characteristics
[0059] The titanyl phthalocyanin crystal as present invention is
characterized by having the maximum peak at a Bragg angle
2.theta..+-.0.2.degree.=27.2.degree. in the CuK.alpha.
characteristic X-ray diffraction spectrum as an optical
characteristic (first optical characteristic). It is preferable
that the crystal has no peak at a Bragg angle
2.theta..+-.0.2.degree.=26.2.degree. in the CuK.alpha.
characteristic X-ray diffraction spectrum (second optical
characteristic).
[0060] It is preferable that the crystal has no peak at a Bragg
angle 2.theta..+-.0.2.degree.=7.2.degree. in the CuK.alpha.
characteristic X-ray diffraction spectrum (third optical
characteristic).
[0061] This is because the stability in organic solvents when no
first optical characteristic tends to be significantly lower than
the titanyl phthalocyanin crystal having such an optical
characteristic. Conversely, the storage stability in organic
solvents may be improved by having the first optical
characteristic, more preferably, the second optical characteristic
and the third optical characteristic.
[0062] It is preferable that the titanyl phthalocyanin crystal
recovered after being immersed in organic solvents for 7 days at
least has the maximum peak at a Bragg angle
2.theta..+-.0.2.degree.=27.2.degree. in the CuK.alpha.
characteristic X-ray diffraction spectrum and no peak at a Bragg
angle 2.theta..+-.0.2.degree.=26.2.degree..
[0063] This is because the crystal transition of the titanyl
phthalocyanin crystal in organic solvents may be more reliably
controlled due to the fact that the titanyl phthalocyanin crystal
may keep the above-mentioned characteristics even if it is immersed
for 7 days in organic solvents.
[0064] It is preferable that the evaluation of immersion test in
organic solvents on the basis of evaluating the storage stability
of the titanyl phthalocyanin crystal is performed under the same
conditions as, for example, conditions for actually keeping a
coating solution for a photosensitive layer for preparing an
electrophotographic photoconductor (called coating solution for the
photosensitive layer hereinafter). Accordingly, for example, it is
preferable that the storage stability of the titanyl phthalocyanin
crystal is evaluated in a closed system under conditions of a
temperature 23.+-.1.degree. C. and relative humidity 50 to 60%
RH.
[0065] It is preferable that the organic solvent is at least one
solvent selected from the group consisting of tetrahydrofuran,
dichloromethane, toluene, 1,4-dioxane and 1-methoxy-2-propanol in
evaluating the storage stability of the titanyl phthalocyanin
crystal.
[0066] This is because the stability of the specific titanyl
phthalocyanin crystal may be more reliably determined and the
compatibility in the specific titanyl phthalocyanin crystal, charge
transfer agent and binder resin, etc. is improved when such organic
solvents are used as organic solvents in the coating solution for
the photosensitive layer. Accordingly, a photoconductor for more
effectively obtaining characteristics of the specific titanyl
phthalocyanin crystal, charge transfer agent, etc. may be formed
and an electrophotographic photoconductor excellent in electric
characteristics and image characteristics may be stably
constituted.
(2) Thermal Characteristics
[0067] In present invention, the titanyl phthalocyanin crystal is
characterized by having one peak within the range of 270 to
400.degree. C. other than a peak accompanied by the vaporization of
adsorbed water in the differential scanning calorimetric
analysis.
[0068] This is because the titanyl phthalocyanin crystal having
such optical characteristics and thermal characteristics may
effectively inhibit the crystal transition of the crystal structure
from .alpha.-type crystal to .beta.-type crystal even if it is
added into an organic solvent and left for a long time.
Accordingly, a coating solution for a photosensitive layer
excellent in storage stability may be obtained by using such a
titanyl phthalocyanin crystal. As a result, an electrophotographic
photoconductor excellent in electric characteristics and image
characteristics may be stably constituted.
[0069] The one peak that is a peak other than a peak accompanied by
the vaporization of adsorbed water and appears within the range of
270 to 400.degree. C. preferably appears within the range of 290 to
400.degree. C. and more preferably within the range of 300 to
400.degree. C.
[0070] A specific method for measuring the Bragg angle in the
CuK.alpha. characteristic X-ray diffraction spectrum and a specific
method of the differential scanning calorimetric analysis will be
described in detail in examples described hereinafter.
2. Structure of Titanyl Phthalocyanin Compounds
[0071] It is preferable that titanyl phthalocyanin compounds are
compounds having the structure represented by the above-mentioned
general formula (1).
[0072] This is because not only the stability of the specific
titanyl phthalocyanin crystal may be further improved, but also the
specific titanyl phthalocyanin crystal may be stably prepared by
using the titanyl phthalocyanin compounds of such a structure.
[0073] It is more preferable that the structure of titanyl
phthalocyanin compounds is represented by the following general
formula (2). It is particularly preferable that the titanyl
phthalocyanin compounds are represented by the following general
formula (3).
[0074] This is because such a structure of titanyl phthalocyanin
allows a specific titanyl phthalocyanin crystal having more stable
property to prepare easily. ##STR2## (In the general formula (2), X
represents a hydrogen atom, a halogen atom, an alkyl group, an
alkoxy group, a cyano group or a nitro group, and the repeat number
"e" represents an integer of 1 to 4.) ##STR3##
Second Embodiment
[0075] Second Embodiment is a method for preparing the titanyl
phthalocyanin crystal having the maximum peak at a Bragg angle
2.theta..+-.0.2.degree.=27.2.degree. in the CuK.alpha.
characteristic X-ray diffraction spectrum and one peak within the
range of 270 to 400.degree. C. other than a peak accompanied by the
vaporization of adsorbed water in the differential scanning
calorimetric analysis and is characterized by comprising the
following processes (a) and (b);
[0076] (a) a process for preparing a titanyl phthalocyanin compound
by adding a titanium alkoxide or titanium tetrachloride at a value
within the range of 0.40 to 0.53 mole with respect to 1 mole of
o-phthalonitrile or its derivative or 1,3-diiminoisoindoline or its
derivative and adding a urea compound at a value within the range
of 0.1 to 0.95 mole with respect to 1 mole of o-phthalonitrile or
its derivative or 1,3-diiminoisoindoline or its derivative to react
the compounds,
[0077] (b) a process for preparing a titanyl phthalocyanin crystal
by performing an acid treatment on the titanyl phthalocyanin
compound prepared in the process (a).
[0078] The contents already described in First Embodiment are
properly omitted and the above-mentioned method for preparing
titanyl phthalocyanin crystal is mainly described hereinafter.
1. A Processes for Preparing a Titanyl Phthalocyanin Compound
[0079] A process for preparing a titanyl phthalocyanin compound is
characterized by reacting o-phthalonitrile or its derivative or
1,3-diiminoisoindoline or its derivative and a titanium alkoxide or
titanium tetrachloride as materials for preparing such a molecule
in the presence of a urea compound to prepare a titanyl
phthalocyanin compound.
[0080] Here, the method for preparing the titanyl phthalocyanin
compound represented by the general formula (3) is specifically
described as an example.
[0081] That is, when the titanyl phthalocyanin compound represented
by the formula (3) is prepared, it is preferably preformed
according to the following reaction formula (1) or the following
reaction formula (2). Titanium tetrabutoxide represented by the
formula (5) is used as one example of the titanium alkoxide in the
following reaction formula (1) and the following reaction formula
(2).
(1) Reaction Formula
[0082] Accordingly, it is preferable that the titanyl phthalocyanin
compound represented by the formula (3) is prepared by reacting
o-phthalonitrile represented by a formula (4) and titanium
tetrabutoxide as a titanium alkoxide represented by the formula (5)
as shown in the reaction formula (1) or reacting
1,3-diiminoisoindoline represented by a formula (6) and a titanium
alkoxide, such as titanium tetrabutoxide, etc. represented by the
formula (5) as shown in the reaction formula (2).
[0083] Titanium tetrachloride may also be used in place of titanium
alkoxide such as titanium tetrabutoxide, etc. represented by the
formula (5). ##STR4## Reaction Formula (1) ##STR5## Reaction
Formula (2) (2) Added Amount
[0084] The added amount of the titanium alkoxide, such as titanium
tetrabutoxide, etc., represented by the formula (5) or titanium
tetrachloride is characterized by setting to a value within the
range of 0.40 to 0.53 mole with respect to 1 mole of
o-phthalonitrile represented by a formula (4) or its derivative or
1,3-diiminoisoindoline represented by the formula (6) or its
derivative.
[0085] This is because the interaction with a urea compound
described hereinafter is effectively obtained by adding an excess
of 1/4 equivalent with respect to the amount of titanium alkoxide,
such as titanium tetrabutoxide, etc., represented by the formula
(5) or titanium tetrachloride to o-phthalonitrile represented by
the formula (4) or its derivative or 1,3-diiminoisoindoline
represented by the formula (6) or its derivative. Such an
interaction will be described in detail in a section of urea
compounds.
[0086] Accordingly, the amount of the titanium alkoxide such as
titanium tetrabutoxide, etc. represented by the formula (5) or
titanium tetrachloride is set to a value preferably within the
range of 0.43 to 0.50 mole and more preferably in a range of 0.45
to 0.47 mole with respect to 1 mole of o-phthalonitrile represented
by the formula (4) or its derivative or 1,3-diiminoisoindoline
represented by the formula (6) or its derivative.
(3) Urea Compounds
[0087] The process (a) is characterized by performing it in the
presence of a urea compound. This is because the interaction in a
urea compound and a titanium alkoxide or titanium tetra-chloride is
obtained by using a titanyl phthalocyanin compound prepared in the
presence of a urea compound, therefore the specific titanyl
phthalocyanin crystal may be prepared.
[0088] That is, such an interaction is an action in which ammonia
generated by the reaction of a urea compound and a titanium
alkoxide or titanium tetrachloride further forms a complex with the
titanium alkoxide or titanium tetrachloride, and such a substance
further accelerates the reaction represented by the reaction
formulas (1) and (2). Then, a titanyl phthalocyanin crystal hard in
crystal transition may be efficiently prepared even in an organic
solvent by reacting the raw materials under such an accelerating
action.
(3)-1 Types
[0089] The urea compounds used in the process (a) are preferably at
least one compound selected from the group consisting of urea,
thiourea, o-methylisourea sulfate, o-methylisourea carbonate and
o-methylisourea hydrochloride.
[0090] This is because ammonia generated in the process of reaction
by using such a urea compound as urea compound in the reaction
formulas (1) and (2) allows a complex with titanium alkoxide or
titanium tetrachloride to form more efficiently, and such a
substance further accelerates the reaction represented by the
reaction formula (1) and (2).
[0091] That is, This is because ammonia generated by reacting a
titanium alkoxide or titanium tetrachloride and a urea compound
forms a complex compound with the titanium alkoxide, etc. more
efficiently and accordingly such a complex compound further
accelerates the reaction represented by the reaction formulas (1)
and (2).
[0092] In addition, it has been known that such a complex compound
allows to specifically form when they are reacted in a high
temperature condition of 180.degree. C. or above. Therefore, the
reactions are performed more effectively in a nitrogen-containing
compound with boiling point of 180.degree. C. or above, e.g.,
quinoline (b.p.: 237.1.degree. C.), isoquinoline (b.p.:
242.5.degree. C.) or their mixture (weight ratio 10:90 to
90:10).
[0093] Accordingly, it is more preferable to use urea in the
above-mentioned urea compounds since ammonia as reaction
accelerator and the complex compound due to it allows to form
easily.
(3)-2 Added Amount
[0094] The added amount of urea compounds used in the process (a)
is characterized by setting to a value within the range of 0.1 to
0.95 mole with respect to 1 mole of o-phthalonitrile or its
derivative or 1,3-diiminoisoindoline or its derivative.
[0095] This is because the action of above-mentioned urea compounds
may be obtained more efficiently by setting the amount of urea
compounds to a value within such a range.
[0096] Accordingly, the amount of such urea compounds is set to a
value within the range of preferably 0.3 to 0.8 mole and more
preferably 0.4 to 0.7 mole with respect to 1 mole of
o-phthalonitrile or its derivative or 1,3-diiminoisoindoline or its
derivative.
(4) Solvents
[0097] As solvents used in the process (a), for example, one or any
combinations of two or more solvent selected from the group
consisting of hydrocarbon solvents such as xylene, naphthalene,
methylnaphthalene, tetralin, and nitrobenzene, etc.; halogenated
hydrocarbon solvents such as dichlorobenzene, tri-chlorobenzen,
dibromobenzene, and chloronaphthalene, etc.; alcohol solvents such
as hexanol, octanol, decanol, benzyl alcohol, ethylene glycol, and
ethylene glycol, etc.; ketone solvents such as dichlorohexanone,
acetophenone, 1-methyl-2-pyrrolidone, and
1,3-dimethyl-2-imidazolidinone, etc.; amide solvents such as
formamide, acetamide, etc.; nitrogen-containing solvents such as
picoline, quinoline, and isoquinoline, etc. are exemplified.
[0098] Particularly, nitrogen-containing solvents of b.p.
180.degree. C. or above, e.g., quinoline and isoquinoline are
suitable in that ammonia is generated by reacting a titanium
alkoxide or titanium tetrachloride as raw material and a urea
compound allows to form a complex compound with the titanium
alkoxide, etc. more efficiently.
(5) Reaction Temperature
[0099] The reaction temperature in the process (a) is preferably a
high temperature condition of 150.degree. C. or above. This is
because the complex compound is hard to be formed by reacting a
titanium alkoxide or titanium tetrachloride as raw material and a
urea compound if such a temperature falls short of 150.degree. C.,
especially lower than 135.degree. C. Accordingly, such a complex
compound becomes difficult to further accelerate the reactions
represented by the reaction formulas (1) and (2), thus the titanyl
phthalocyanin crystal hard in crystal transition becomes difficult
to be efficiently prepared even in an organic solvent.
[0100] Accordingly, the reaction temperature in the process (a) is
preferably set to a value within the range of 180 to 250.degree.
C., and more preferably a value within the range of 200 to
240.degree. C.
(6) Reaction Time
[0101] The reaction time in the process (a) is dependent upon the
reaction temperature, but it is preferably set to a range of 0.5 to
10 hrs. This is because a complex compound becomes hard to form by
reacting a titanium alkoxide or titanium tetrachloride as raw
material and a urea compound if such a reaction time falls short of
0.5 hrs. Accordingly, such a complex compound becomes difficult to
further accelerate the reactions represented by the reaction
formulas (1) and (2), thus the titanyl phthalocyanin crystal hard
in crystal transition becomes difficult to be efficiently prepared
even in an organic solvent. On the other hand, if such a reaction
time exceeds 10 hrs, it leads to disadvantage in economy or
sometimes the formed complex compound is reduced.
[0102] Accordingly, the reaction time in the process (a) is
preferably set to a value within the range of 0.6 to 3.5 hrs, and
more preferably set to a value in a range of 0.8 to 3 hrs.
2. A processes for Preparing Titanyl Phthalocyanin Crystal
[0103] Next, it is preferable that an acid treatment as a
post-treatment is performed for the titanyl phthalocyanin compound
prepared in the above-mentioned process to obtain a titanyl
Phthalocyanin crystal.
(1) Preliminary Process for Acid Treatment
[0104] As a preliminary step for performing the acid treatment, it
is preferable to perform a preliminary process for acid treatment,
the titanyl phthalocyanin compound obtained by the above-mentioned
reactions is added into a water-soluble organic solvent, stirred
for a predetermined time under heating, and then the solution is
allowed to be left standing and stabilize for a predetermined time
under a condition of lower temperature than the stirring
treatment.
[0105] As water-soluble organic solvents used in the process prior
to acid treatment, for example, one, two or more of alcohols such
as methanol, ethanol and isopropanol, etc.; N,N-dimethylformamide,
N,N-dimethylacetamide, propionic acid, acetic acid,
N-methylpyrrolidone, and ethylene glycol, etc. are exemplified. A
small amount of non-water soluble organic solvents may also be
added into the water-soluble organic solvents.
[0106] Although conditions for stirring treatment in the
preliminary process for acid treatment are not specially limited,
it is preferable to perform a stirring treatment of about 1 to 3
hrs under a predetermined temperature condition within a
temperature range of about 70 to 200.degree. C.
[0107] Although conditions for stabilization treatment after the
stirring treatment are also not specially limited, it is preferable
to allow the solution to be left standing and stabilize for about 5
to 15 hrs under a predetermined temperature condition within a
temperature range of about 10 to 50.degree. C., preferably about
23.+-.1.degree. C.
(2) Acid Treatment Process
[0108] Next, it is preferable to perform the acid treatment process
as follows.
[0109] That is, it is preferable that the titanyl phthalocyanin
crystal obtained in the above-mentioned preliminary process for
acid treatment is dissolved in an acid, then the solution is
dropped to water and recrystallized, subsequently the obtained
titanyl phthalocyanin crystal is washed in an aqueous alkali
solution. More specifically, it is preferable that the obtained
crude crystal is dissolved in an acid, this solution is dropped
into water under ice cooling and then stirred for a predetermined
time, further allowed to be left standing and recrystallized at a
temperature within the range of 10 to 30.degree. C. Subsequently,
it is preferable that the crystal is not dried and stirred at 30 to
70.degree. C. for 2 to 8 hrs in a non-aqueous solvent in the
presence of water.
[0110] As acids used in the acid treatment, for example,
concentrated sulfuric acid, trifluoroacetic acid and sulfonic acid,
etc. are preferably used.
[0111] This is because impurities may be fully decomposed by using
such strong acids in the acid treatment while the decomposition of
the specific titanyl phthalocyanin crystal may be inhibited.
Accordingly, a titanyl phthalocyanin crystal having a high-purity
and excellent property in crystallinity may be obtained.
[0112] As aqueous alkali solutions used in the washing treatment,
for example, common aqueous alkali solutions such as aqueous
ammonia solution, aqueous sodium hydroxide solution, etc. may be
preferably used.
[0113] This is because the ambience of the crystal may be made from
acidity to neutrality by washing the specific titanyl phthalocyanin
crystal after the acid treatment with such aqueous alkali
solutions. As a result, the handling of the crystal in subsequent
processes may be facilitated and the stability of the crystal may
be improved.
[0114] As non-aqueous solvents for the stirring treatment, for
example, halogen solvents such as chlorobenzen and dichloromethane,
etc. are exemplified.
Third Embodiment
[0115] Third Embodiment is an electrophotographic photoconductor
characterized in that a photosensitive layer is provided on a
conductive substrate, and the photosensitive layer comprises the
titanyl phthalocyanin crystal having the maximum peak at a Bragg
angle 2.theta..+-.0.2.degree.=27.2.degree. in the CuK.alpha.
characteristic X-ray diffraction spectrum and one peak in a range
of 270 to 400.degree. C. other than a peak accompanied by the
vaporization of adsorbed water in the differential scanning
calorimetric analysis within the range of 0.1 to 50 part by weight
with respect to 100 part by weight of a binder resin forming the
photosensitive layer.
[0116] The contents already described in Embodiments 1 and 2 are
omitted and the above-mentioned method for preparing titanyl
phthalocyanin crystal is described as Third Embodiment
hereinafter.
[0117] There are a single layer photoconductor and a laminated
layer photoconductor in organic photoconductors, and the present
invention is applicable to the both photoconductors.
1. Single Layer Photoconductor
(1) Basic Construction
[0118] As shown in FIG. 1(a), a single layer photoconductor 10 is
provided with a single photo-sensitive layer 14 on a conductive
substrate 12. Such a photosensitive layer 14 comprises a specific
titanyl phthalocyanin crystal as a charge generating agent, a
charge transfer agent and a binder resin in the same layer.
[0119] The thickness of photosensitive layer is preferably set to a
value within the range of 5 to 100 .mu.m, and more preferably a
value within the range of 10 to 50 .mu.m.
[0120] As shown in FIG. 1(b), the single layer photoconductor may
also be a photoconductor 10' formed with a barrier layer 16 in a
range where characteristics of the photoconductor is not inhibited
between the conductive substrate 12 and the photosensitive layer
14. As shown in FIG. 1(c), it may also be a photoconductor 10''
formed with a protective layer 18 at the surface of photosensitive
layer 14.
[0121] The single layer photoconductor preferably contains either a
hole transfer agent or an electron transfer agent as a charge
transfer agent contained in the photosensitive layer.
[0122] This is because characteristics of such a titanyl
phthalocyanin crystal may be fully obtained while its constitution
may be performed stably and economically as compared with the
laminated layer photoconductor described hereinafter. That is, an
electrophotographic photoconductor having the good electric
characteristics and image characteristics that may be fully
obtained by the characteristics of a specific titanyl phthalocyanin
crystal as a charge generating agent has may be constituted stably
and economically.
[0123] The single layer photoconductor also preferably contains
both a hole transfer agent and an electron transfer agent as charge
transfer agents.
[0124] This is because characteristics of the specific titanyl
phthalocyanin crystal may be fully obtained and a charge generated
from such a titanyl phthalocyanin crystal may be transferred more
efficiently in an exposure process. As a result, an
electrophotographic photoconductor having better electric
characteristics and image characteristics may be obtained.
(2) Charge Generating Agents
(2)-1 Types
[0125] The charge generating agent used in the photoconductor as
the present invention is characterized by the titanyl phthalocyanin
crystal having the maximum peak at a Bragg angle
2.theta..+-.0.2.degree.=27.2.degree. in the CuK.alpha.
characteristic X-ray diffraction spectrum and one peak within the
range of 270 to 400.degree. C. other than a peak accompanied by the
vaporization of adsorbed water in the differential scanning
calorimetric analysis.
[0126] This is because an electrophotographic photoconductor having
good electric characteristics and image characteristics may be
obtained by using the titanyl phthalocyanin crystal that satisfies
such conditions, is hard to change its crystal type and has stable
characteristics even in an organic solvent as a charge generating
agent.
[0127] In addition, details on such a specific titanyl
phthalocyanin crystal are already described in Embodiments 1 and 2,
therefore they are omitted to avoid repetition.
[0128] Other charge generating agents may also be used together to
adjust the sensitivity region of the photoconductor. As other
charge generating agents, they are not specially limited, for
example, one, two or more of powders of inorganic photoconductive
materials such as selenium, selenium-tellurium, selenium-arsenic,
cadmiun sulfide and a-silicon, etc.; azo pigment, perylene pigment,
anthanthrone pigment, conventional phthalocyanin pigment other than
the titanyl phthalocyanin crystal of present invention, indigo
pigment, triphenylmethane pigment, threne pigment, toluidine
pigment, pyrazoline pigment, quinacridone pigment, and
dithioketopyrrolopyrrole pigment, etc. are exemplified.
(2)-2 Added Amount
[0129] The amount of charge generating agent is characterized by
setting to a value within the range of 0.1 to 50 part by weight
with respect to 100 part by weight of binder resin described
hereinafter.
[0130] This is because the charge generating agent may efficiently
generates a charge when exposing it to the photoconductor by
setting the amount of charge generating agent to a value within
such a range.
[0131] That is, if the amount of such a charge generating agent
falls short of 0.1 part by weight with respect to 100 part by
weight of a binder resin, the generation of charge sometimes
becomes insufficient to form an electrostatic latent image on the
photoconductor. On the other hand, if the amount of such a charge
generating agent exceeds 50 part by weight with respect to 100 part
by weight of a binder resin, uniform distribution in a coating
solution for a photosensitive layer sometimes becomes
difficult.
[0132] Accordingly, the amount of charge generating agent with
respect to 100 part by weight of a binder resin is preferably set
to a value within the range of 0.5 to 30 part by weight.
[0133] In addition, when only the titanyl phthalocyanin crystal of
present invention is used as a charge generating agent, the amount
of charge generating agent is an amount of the titanyl
phthalocyanin crystal; and when the titanyl phthalocyanin crystal
of present invention is used together with other charge generating
agents, the amount of charge generating agent is the total amount
of both.
[0134] When the titanyl phthalocyanin crystal as the present
invention is used together with other charge generating agents, the
other charge generating agents are preferably added in a small
amount in a range as long as not disturbing the above-mentioned
effects of the titanyl phthalocyanin crystal. More specifically,
the other charge generating agents are preferably added in a ratio
within the range of 100 part by weight or less with respect to 100
part by weight of the titanyl phthalocyanin crystal.
(3) Binder Resins
[0135] As binder resins, for example, thermoplastic resins such as
styrene polymer, styrene-butadiene copolymer, styrene-acrylonitrile
copolymer, styrene-maleic acid copolymer, acrylic polymer,
styrene-acrylic copolymer, polyethylene, ethylene-vinyl acetate
copolymer, chlorinated polyethylene, polyvinyl chloride,
polypropylene, polyvinyl-vinylacetate copolymer, polyester, alkyd
resin, polyamide, polyurethane, polycarbonate, polyacrylate,
polysulfone, diallylphthalate resin, ketone resin, polyvinyl
butyral resin, and polyether resin, etc.; cross-linkable
thermosetting resins such as silicone resin, epoxy resin, phenol
resin, urea resin, melamine resin, etc.; photosetting resins such
as epoxyacrylate, urethaneacrylate, etc. are exemplified. These
binder resins may be used separately or used together by combining
two or more.
(4) Electron Transfer Agent
(4)-1 Types
[0136] As electron transfer agents, all conventional well-known
various electron transferable compounds are available.
Particularly, electron attractive compounds such as benzoquinone
compounds, diphenoquinone compounds, naphthoquinone compounds,
malononitrile, thiopyrane compounds, tetracyanoethylene,
2,4,8-trinitrothioxanthone, fluorenone compounds [e.g.,
2,4,7-trinitro-9-fluorenone, etc.], dinitrobenzene,
dinitroanthracene, dinitroacridine, nitroanthraquinone, succinic
anhydride, maleic anhydride, dibromomaleic anhydride,
2,4,7-trinitrofluorenone imine compounds, ethylated fluorenone
imine compounds, azafluorenone compounds, dinitropyridoquinazoline
compounds, thioxanthene compounds, 2-phenyl-1,4-benzoquinone
compounds, 2-phenyl-1,4-naphtoquinone compounds,
5,12-napthtathenquinone compounds, .alpha.-cyanostilbene compounds,
4-nitrostilbene compounds and salts of an anion radical of
benzoquinone compound and a cation, etc. are suitably used. They
may be used separately or used together by combining two or
more.
[0137] Among these compounds, all electron transfer agents
represented by the following formulas (7) to (21) (ETM-1 to 15)
have good fitting ability such as compatibility for the titanyl
phthalocyanin crystal as the present invention, etc. and are
suitably used as electron transfer agents excellent in electron
transfer capability. ##STR6## ##STR7## ##STR8## ##STR9## (4)-2
Added Amount
[0138] The amount of electron transfer agent is preferably set to a
value within the range of 20 to 500 part by weight with respect to
100 part by weight of a binder resin and more preferably a value
within the range of 30 to 200 part by weight with respect to 100
part by weight of the binder resin. When an electron transfer agent
and a hole transfer agent described hereinafter are used together,
the total amount is preferably set to a value within the range of
20 to 500 part by weight and more preferably a value in a range of
30 to 200 part by weight with respect to 100 part by weight of the
binder resin.
[0139] When an electron transfer agent and a hole transfer agent
described later are used together, the amount of electron transfer
agent is preferably set to a value within the range of 10 to 100
part by weight with respect to 100 part by weight of the hole
transfer agent.
(5) Hole Transfer Agent
(5)-1 Types
[0140] As hole transfer agents, all conventional well-known various
electron transferable compounds are usable. Particularly, benzidine
compounds, phenylenediamine compounds, naphthylenediamine
compounds, phenantolylenediamine compounds, oxadiazole compounds
[e.g., 2,5-di(4-methylaminophenyl)-1,3,4-oxadiazole, etc.], styryl
compounds [e.g., 9-(4-diethylamino-styryl)anthracene, etc.],
carbazole compounds [e.g., poly-N-vinylcarbazole, etc.],
organopolysilane compounds, pyrazoline compounds [e.g.,
1-phenyl-3-(p-dimethylaminophenyl)pyrazoline, etc.], hydrazone
compounds, triphenylamine compounds, indole compounds, oxazole
compounds, isooxazole compounds, thiazole compounds, thiadizole
compounds, imidazole compounds, pyrazole compounds, triazole
compounds, butadiene compounds, pyrenehydrazone compounds, acrolein
compounds, carbazolehydrazone compounds, quinoline-hydrazone
compounds, stilbene compounds, stilbene-hydrazone compounds, and
diphenyldiamine compounds, etc. are preferably used. They may be
used separately or used together by combining two or more.
[0141] Among these compounds, all compounds represented by the
following formulas (22) to (46) (HTM-1 to 25) have good fitting
ability such as compatibility for the titanyl phthalocyanin crystal
and are suitably used as hole transfer agents excellent in hole
transfer capability. ##STR10## ##STR11## ##STR12## ##STR13##
##STR14## (5)-2 Added Amount
[0142] The amount of hole transfer agent is preferably set to a
value within the range of 20 to 500 part by weight with respect to
100 part by weight of a binder resin and more preferably as a value
in a range of 30 to 200 part by weight with respect to 100 part by
weight of the binder resin. When a hole transfer agent and the
electron transfer agent described above are used together, the
total amount is preferably set to a value within the range of 20 to
500 part by weight and more preferably a value within the range of
30 to 200 part by weight with respect to 100 part by weight of the
binder resin.
(6) Other Additives
[0143] In addition to the components described above, various
additives such as sensitizer, fluorene compound, ultraviolet
absorbent agent, plasticizer, surfactant, leveling agent, etc. may
also be added in the photosensitive layer. For example, a
sensitizer such as terphenyl, halonaphthoquinones, and
acenaphthylene, etc. may be used together with the charge
generating agent to improve the sensitivity of photoconductor.
(7) Conductive Substrates
[0144] As conductive substrates formed on the photosensitive layer
described above, various materials having conductivity may be used.
Conductive substrates formed by metals such as iron, aluminum,
copper, tin, platinum, silver, vanadium, molybdenum, chromium,
cadmium, titanium, nickel, palladium, indium, stainless steel, and
brass, etc., substrates made of a plastic material which the above
metal is vapor-deposited or laminated, or glass substrates coated
with aluminum iodide, tin oxide, and indium oxide, etc. are
exemplified.
[0145] That is, the substrate may have conductivity in their own or
their surface may have conductivity. The conductive substrates
preferably have sufficient mechanical strength in use.
[0146] The shape of conductive substrates may be any of sheet or
drum-type, etc. in conformity to the structure of used image
forming device.
(8) Manufacturing Method
[0147] In constituting a single layer photoconductor, a binder
resin, a charge generating agent, a hole transfer agent and, if
necessary, an electron transfer agent are added into a solvent,
dispersed and mixed to prepare a coating solution for a
photosensitive layer. That is, when a single layer photoconductor
is formed by coating process, a titanyl phthalocyanin crystal as a
charge generating agent, a charge transfer agent and a binder
resin, etc. may be dispersed and mixed with a proper solvent by a
well-known method, e.g., roller mill, ball mill, attritor, paint
shaker, and supersonic disperser, etc. to prepare a dispersion,
then applied and dried by a well-known means.
[0148] As solvents for preparing the coating solution for the
photosensitive layer, one, two or more of tetrahydrofuran,
dichloromethane, toluene, 1,4-dioxane, and 1-methoxy-2-propanol,
etc. are exemplified.
[0149] Furthermore, a surfactant or a leveling agent, etc. may also
be added to improve the dispersibility of the charge transfer agent
or charge generating agent and the smoothness of surface of the
photosensitive layer in the coating solution for the photosensitive
layer.
2. Laminated Photoconductor
(1) Basic Construction
[0150] As shown in FIG. 2, a laminated layer photoconductor 20 may
be constituted by forming a charge generating layer 24 containing a
specific titanyl phthalocyanin crystal as charge generating agent
on a substrate 12 by a deposition or coating means and then
applying a coating solution for a photosensitive layer containing a
charge generating agent, etc. and a binder resin on this charge
generating layer and drying to form a charge transfer layer 22.
[0151] In contrast with the above construction, as shown in FIG. 2,
the charge transfer layer 22 may be formed on the substrate 12 and
the charge generating layer 24 may be formed thereon.
[0152] However, the charge generating layer 24 has an extremely
thin film thickness as compared with the charge transfer layer 22,
therefore, as shown in FIG. 2, the charge transfer layer 22 is more
preferably formed on the charge generating layer 24 for its
protection.
[0153] Either a hole transfer agent or a electron transfer agent is
preferably contained in the charge transfer layer 22.
[0154] By such a construction, a photosensitive layer may be
constructed with the above-mentioned titanyl phthalocyanin crystal,
a binder resin with good fitting ability for such a titanyl
phthalocyanin crystal and a solvent, etc. with no need of
especially considering the fitting ability with a charge transfer
agent. Accordingly, characteristics of such a titanyl phthalocyanin
crystal may be more effectively obtained and an electrophotographic
photoconductor excellent in electric characteristics and image
characteristics may be stably prepared.
[0155] Whether this laminated layer photoconductor becomes
positively or negatively charged type is selected according to the
order of forming the above-mentioned charge generating layer and
charge transfer layer and the type of charge transfer agent used in
the charge transfer layer. For example, as shown in FIG. 2, when
the charge generating layer 24 is formed on the substrate 12 and
the charge transfer layer 22 is formed thereon and when a hole
generating agent such as amino compound derivative or stilbene
derivative is used as charge transfer agent in the charge transfer
layer 22, the photoconductor becomes the negatively charged type.
In this case, a charge transfer agent may also be contained in the
charge generating layer 24. Then, if the photoconductor is such a
laminated type electrophotographic photoconductor, the residual
potential of photoconductor is greatly reduced and the sensitivity
may be improved.
[0156] The thickness of photosensitive layer in the laminated layer
photoconductor is preferably set to a value within the range where
the thickness of charge generating layer is 0.01 to 5 .mu.m, and
more preferably a value within the range where the thickness of
charge generating layer is 0.1 to 3 .mu.m.
[0157] The same substrate as the above-mentioned single layer
photoconductor may be used as a substrate formed with such a
photosensitive layer.
[0158] As shown in FIG. 2, an intermediate layer 25 is preferably
formed on such a substrate 12 before the photosensitive layer is
formed. This is because the substrate side charge is prevented from
being easily injected into the photosensitive layer, the
photosensitive layer is strongly bound on the substrate 12 and
surface defects at the substrate 12 may be covered and made smooth
by providing such an intermediate layer 25.
(2) Types
[0159] When the laminated layer photoconductor of the present
invention is constituted, the types of charge generating agent,
hole generating agent and binder resin and other additives may be
basically the same contents as the above-mentioned single layer
photoconductor.
(3) Added Amount
[0160] The amount of charge generating agent used in the laminated
layer photoconductor of the present invention is preferably set to
a value within the range of 5 to 1,000 part by weight and more
preferably a value within the range of 30 to 500 part by weight
with respect to 100 part by weight of a binder resin constructing
the charge generating layer.
[0161] The charge transfer agent and the binder resin constructing
the charge transfer agent may be mixed in various ratios within the
range of no inhibition of charge transfer and no crystallization,
but the amount of charge transfer agent is preferably set to a
value within the range of 10 to 500 part by weight and more
preferably a value within the range of 25 to 200 part by weight
with respect to 100 part by weight of the binder resin so that a
charge generated in the charge generating layer may be easily
transferred by illumination.
[0162] In addition, the amount of charge transfer agent represents
a total of the amount of charge transfer agent and the amount of
hole transfer agent, when only either charge transfer agent or hole
transfer agent is added, it represents only the amount of added
charge transfer agent.
(4) Manufacturing Methods
[0163] In the methods for manufacturing the charge generating
layer, charge transfer layer and intermediate layer, a binder resin
is dispersed and other additives are dispersed and mixed with a
proper dispersion medium by a well-known method to prepare a
coating solution for a photosensitive layer, respectively, then the
coating solution is applied by a well-known method and dried,
respectively.
EXAMPLES
[0164] Hereinafter, the present invention will be concretely
described with reference to examples thereof.
Example 1
1. Preparation of Titanyl Phthalocyanin
[0165] To an argon-substituted flask, 22 g (0.17 mole) of
o-phthalonitrile, 25 g (0.073 mole) of titanium tetrabutoxide, 2.28
g (0.038 mole) of urea and 300 g of quinone were added and heated
up to 150.degree. C. while stirring. Next, the mixture was heated
up to 215.degree. C. while removing a vapor generated from the
reaction system to the outside, then stirred and reacted for
additional 2 hrs while keeping this reaction temperature.
[0166] After the reaction finished, the reaction mixture was
withdrawn from the flask at a time of cooling it to 150.degree. C.,
filtered with a glass filter, the resultant solid was washed with
N,N-dimethylformamide and methanol in order, vacuum dried and 24 g
of a blue-purple solid was obtained
2. Preparation for Titanyl Phthalocyanin Crystal
(1) Preliminary Process for Acid Treatment
[0167] 10 g of the blue-purple solid obtained in the
above-mentioned preparation of the titanyl phthalocyanin was added
in 100 mL of N,N-dimethylformamide, heated up to 130.degree. C.
while stirring and then stirred for 2 hrs. Next, the heating was
stopped after a lapse of 2 hrs, the mixture was cooled to
23.+-.1.degree. C., then the stirring was stopped, the liquid was
allowed to be left standing for 12 hrs in this state to perform a
stabilization treatment. Subsequently, the stabilized liquid was
filtered with a glass filter, the obtained solid was washed with
methanol, vacuum dried and 9.83 g of a crude crystal of titanyl
phthalocyanin compound was obtained.
(2) A Process for Acid Treatment
[0168] 5 g of the crude crystal of titanyl phthalocyanin compound
obtained in the above-mentioned preliminary process of acid
treatment was added to 100 ml of concentrated sulfuric acid and
dissolved. Next, the solution was dropped into water under ice
cooling and then stirred at room temperature for 15 min, further
allowed to be left standing near 23.+-.1.degree. C. for 30 min and
recrystallized. Next, the above-mentioned liquid was filtered with
a glass filter, the obtained solid was washed with water until the
wash solution became neutral, then dispersed in 200 ml of
chlorobenzen, heated to 50.degree. C. and stirred for 10 hrs in a
state that water existed without being dried. Subsequently, the
liquid was filtered with a glass filter, and then the obtained
solid was vacuum dried at 50.degree. C. for 5 hrs and 4.1 g of a
non-substituted titanyl phthalocyanin crystal (a blue powder)
represented by the formula (3) was obtained.
3. Optical Characteristics and Thermal Characteristics
(1) Measurement of CuK.alpha. Characteristic X-Ray Diffraction
Spectrum
[0169] 0.3 g of the obtained titanyl phthalocyanin within 60 min
after preparation was dispersed in 5 g of tetrahydrofuran, kept in
a closed system for 7 days under conditions of temperature
23.+-.1.degree. C. and relative humidity 50 to 60% RH, and then
packed in a sample holder of an X-ray diffractometer (RINT1100 made
by Rigaku Denki, Inc.) and measured.
[0170] Measuring conditions were as follows for both initial
measurement and re-measurement.
X-ray tube ball: Cu
Tube voltage: 40 kV
Tube current: 30 mA
Start angle: 3.0.degree.
Stop angle: 40.0.degree.
Scanning speed: 10.degree./min
[0171] The CuK.alpha. characteristic X-ray diffraction spectrum was
evaluated by the following criteria. The obtained results are shown
in Table 1 and FIG. 3.
.smallcircle.: A strong peak exists at a Bragg angle
2.theta..+-.0.2.degree.=27.2.degree. and no peaks at 7.2.degree.
and 26.2.degree..
x: A small peak at a Bragg angle
2.theta..+-.0.2.degree.=27.2.degree. and a strong peak at
26.2.degree..
(2) Differential Scanning Calorimetric Analysis
[0172] The differential scanning calorimetric analysis of the
obtained titanyl phthalocyanin crystal was performed by a
differential scanning calorimeter (TAS-200 model, DSC8230D made by
Rigaku Denki, Inc.). Measurement conditions are as follows. A
differential scanning calorimetric analysis chart is shown in FIG.
4, but one peak was observed at 296.degree. C.
Sample pan: aluminum
Heating rate: 20.degree. C./min
4. Constitution of Single Layer Photoconductor
[0173] 5 part by weight of the obtained titanyl phthalocyanin
crystal, 70 part by weight of a hole transfer agent represented by
the formula (22) (HTM-1), 30 part by weight of an electron transfer
agent represented by the formula (7) (ETM-1) and 100 part by weight
of a polycarbonate (TS2020 made by Teijin Chemical, Ltd.) as a
binder resin as well as 800 part by weight of tetrahydrofuran were
mixed and dispersed together by a supersonic disperser and a
coating solution for single layer photosensitive layer was the
prepared.
[0174] Next, this coating solution for the photosensitive layer was
applied to an aluminum drum-type support of 30 mm in diameter and
254 mm in total length by dip coating process within about 60 min
immediately after preparing. Subsequently, an electrophotographic
photoconductor having a single layer photosensitive layer of 25
.mu.m in film thickness was constituted by heat treatment at
130.degree. C. for 30 min.
[0175] The above-mentioned coating solution for the photosensitive
layer was stored for 7 days in a closed system at temperature
23.+-.1.degree. C. and relative humidity 50 to 60% RH. Next, it was
dispersed again by a supersonic disperser and then applied to an
aluminum drum-type support of 30 mm in diameter and 254 mm in total
length as conductive substrate by using dip coating process in the
same manner. Subsequently, a single layer photoconductor of 25
.mu.m in film thickness was constituted by heat treatment at
130.degree. C. for 30 min.
5. Evaluation of Single Layer Photoconductor
(1) Electric Characteristics
[0176] The bright potential Vr1 (V) of the photosensitive layer
formed with a coating solution for a photosensitive layer for the
single layer photosensitive layer immediately after preparation and
the dark potential Vr2 (V) of the photosensitive layer formed with
a coating solution for a photosensitive layer after 7 day storage
were measured under the following conditions, respectively.
[0177] That is, the prepared electrophotographic photoconductor was
charged on a surface potential +700 V by corona discharge using a
drum sensitivity tester under a normal temperature condition and a
normal humidity condition (temperature: 20.degree. C. and humidity:
60%).
[0178] Next, a light of light intensity 8 .mu.m/cm.sup.2, which was
monochromatized to a wavelength 780 nm and a half-value width 20
nm, was exposed for 1.5 sec at the surface of the
electrophotographic photoconductor with a band-pass filter while
the surface potential after 0.5 sec from the start of exposure was
measured as bright potential. Then, .DELTA.Vr (V) (=Vr2-Vr1) was
calculated and evaluated by the following criteria as an electric
characteristic of the photosensitive layer from the absolute value
of bright potential change. The obtained result is shown in Table
1.
+ (excellent): The absolute value of bright potential change falls
short of 10 V.
- (poor): The absolute value of bright potential change is 10 V or
above.
(2) Image Fogging
[0179] Image formation was performed under a high temperature
condition and a high humidity condition (temperature: 35.degree. C.
and humidity: 85%) by a printer FS1010 (made by Kyocera, Ltd.)
loaded with an electrophotographic photoconductor which was
constituted with the coating solution for the photosensitive layer
after 7 day storage to print ISO 5% continuous 200,000 pieces and
ISO 2% intermittent 50,000 pieces.
[0180] Next, the density of non-printing area in printing ISO 5%
continuous 200,000 pieces and ISO 2% intermittent 50,000 pieces was
measured by a spectrophotometer SpectroEye (manufactured by
GretagMacbeth, Ltd.), and the image fogging was estimated by the
following criteria. The obtained result is shown in Table 1.
++ (excellent): The density of non-printing area falls short of
0.008 and no any poor fogging was observed.
+ (acceptable): The density of non-printing area is more than 0.008
and falls short of 0.015 and a little poor fogging was
observed.
- (poor): The density of non-printing area is more than 0.015 and
remarkable poor fogging was observed.
Examples 2 to 21
[0181] Effects of the types of hole transfer agents and electron
transfer agents were investigated in Examples 2 to 21. That is, the
preparation of titanyl phthalocyanin crystals and the constitution
of single layer photoconductors were performed and evaluated in the
same manner as Example 1, respectively except that hole transfer
agents (HTM-1 to 7) and electron transfer agents (ETM-1 to 3) as
shown in Table 1 were used in place of the hole transfer agent
(HTM-1) and the electron transfer agent (ETM-1) used in Example 1
in constituting photoconductors, respectively. The obtained results
are shown in Table 1.
[0182] A titanyl phthalocyanin crystal used in Examples 2 to 21 is
same as in Example 1, therefore the CuK.alpha. characteristic X-ray
diffraction spectrum and the differential scanning calorimetric
analysis chart are same as in Example 1.
Examples 22 to 42
[0183] An effect of the amount of urea used in preparing titanyl
phthalocyanin compounds was investigated in Examples 22 to 42.
[0184] That is, the preparation of titanyl phthalocyanin crystals
and the constitution of single layer photoconductors were performed
and evaluated in the same manner as Examples 1 to 21, respectively
except that the amount of urea used in preparing titanyl
phthalocyanin compounds was 5.70 g (0.095 mole) in place of 2.28 g
(0.038 mole) used in Examples 1 to 21, respectively. The obtained
results are shown in Table 1, FIG. 5 and FIG. 6.
Examples 43 to 63
[0185] An effect of the amount of urea used in preparing titanyl
phthalocyanin compounds was investigated in Examples 43 to 63.
[0186] That is, the preparation of titanyl phthalocyanin crystals
and the constitution of single layer photoconductors were performed
and evaluated in the same manner as Examples 1 to 21, respectively
except that the amount of urea used in preparing titanyl
phthalocyanin compounds was 8.40 g (0.14 mole) in place of 2.28 g
(0.038 mole) used in Examples 1 to 21, respectively. The obtained
results are shown in Table 1, FIG. 7 and FIG. 8.
Comparative Examples 1 to 21
[0187] The preparation of titanyl phthalocyanin crystals and the
constitution of single layer photoconductors were performed and
evaluated in the same manner as Examples 1 to 21, respectively
except that urea was not used in preparing titanyl phthalocyanin
compounds in Comparative examples 1 to 21, respectively. The
obtained results are shown in Table 2, FIG. 9 and FIG. 10.
Comparative Examples 22 to 42
[0188] The preparation of titanyl phthalocyanin crystals and the
constitution of single layer photoconductors were performed and
evaluated in the same manner as Examples 1 to 21, respectively
except that 2 g of a non-crystalline titanyl phthalocyanin compound
in the preliminary step of acid treatment in Comparative examples 1
to 21 was put into a glass beaker and dimethylene glycol
dimethylether was added until the total amount became 200 mL in
preparing the titanyl phthalocyanin crystal, respectively,
subsequently it was stirred at 23.+-.1.degree. C. for 24 hrs to
give a titanyl Phthalocyanin crystal in Comparative examples 22 to
42. The obtained results are shown in Table 2, FIG. 11 and FIG.
12.
Comparative Examples 43 to 63
[0189] In Comparative examples 43 to 63, 5 g of a crude
non-crystalline titanyl phthalocyanin crystal after the preliminary
process of acid treatment in Comparative examples 1 to 21 was added
to 100 ml of a mixed solvent of dichloromethane and trifluoroacetic
acid (volume ratio 4:1) and dissolved. Next, this solution was
dropped into a mixed lean solvent of methanol and water (volume
ratio 1:1), then stirred at room temperature for 15 min, allowed to
be left standing and recrystallized at 23.+-.1.degree. C. for 30
min. Next, the above-mentioned liquid was filtered with a glass
filter, the obtained solid was washed with water until the wash
solution became neutral, then dispersed in 200 ml of chlorobenzen
and stirred at room temperature for 1 hr in a state that water
existed without being dried at 50.degree. C. for 5 hrs.
Subsequently, the solution was filtered with a glass filter, then
the obtained solid was vacuum dried and 4.2 g of a non-substituted
titanyl phthalocyanin crystal (blue powder) represented by the
formula (3) was obtained.
[0190] Besides, the preparation of titanyl phthalocyanin crystal
and the constitution of single layer photoconductor were performed
and evaluated in the same manner as Comparative examples 1 to 21,
respectively. The obtained results are shown in Table 2, FIG. 13
and FIG. 14.
Comparative Examples 64 to 84
[0191] The preparation of titanyl phthalocyanin crystal and the
constitution of single layer photoconductor were performed and
evaluated in the same manner as Examples 22 to 42, respectively
except that the amount of titanium tetrabutoxide used in preparing
a titanyl phthalocyanin crystal was 15.0 g (0.044 mole) in
Comparative examples 64 to 84 in place of 25.0 g (0.073 mole) in
Examples 22 to 42. The obtained results are shown in Table 3, FIG.
15 and FIG. 16.
Comparative Examples 85 to 105
[0192] The preparation of titanyl phthalocyanin crystal and the
constitution of single layer photoconductor were performed and
evaluated in the same manner as Examples 1 to 21, respectively
except that the amount of urea used in preparing a titanyl
phthalocyanin crystal was 20.25 g (0.342 mole) in Comparative
examples 85 to 105 in place of 2.28 g (0.038 mole) in Examples 1 to
21. The obtained results are shown in Table 3, FIG. 17 and FIG. 18.
TABLE-US-00001 TABLE 1 Bragg Angle DSC Peak Electric Characteristic
2.theta. .+-. 0.2.degree. Temp. Number Bright Potential Peak
Evaluation (.degree. C.) (peak) HTM ETM Change (V) Evaluation Image
Fog Example 1 .largecircle. 296 1 HTM-1 ETM-1 1 .largecircle.
.largecircle. Example 2 ETM-2 0 .largecircle. .largecircle. Example
3 ETM-3 -2 .largecircle. .largecircle. Example 4 HTM-2 ETM-1 1
.largecircle. .largecircle. Example 5 ETM-2 1 .largecircle.
.largecircle. Example 6 ETM-3 1 .largecircle. .largecircle. Example
7 HTM-3 ETM-1 2 .largecircle. .largecircle. Example 8 ETM-2 -3
.largecircle. .largecircle. Example 9 ETM-3 2 .largecircle.
.largecircle. Example 10 HTM-4 ETM-1 2 .largecircle. .largecircle.
Example 11 ETM-2 -2 .largecircle. .largecircle. Example 12 ETM-3 2
.largecircle. .largecircle. Example 13 HTM-5 ETM-1 -1 .largecircle.
.largecircle. Example 14 ETM-2 -1 .largecircle. .largecircle.
Example 15 ETM-3 0 .largecircle. .largecircle. Example 16 HTM-6
ETM-1 7 .largecircle. .largecircle. Example 17 ETM-2 5
.largecircle. .largecircle. Example 18 ETM-3 3 .largecircle.
.largecircle. Example 19 HTM-7 ETM-1 2 .largecircle. .largecircle.
Example 20 ETM-2 -1 .largecircle. .largecircle. Example 21 ETM-3 3
.largecircle. .largecircle. Example 22 .largecircle. 327 1 HTM-1
ETM-1 1 .largecircle. .largecircle. Example 23 ETM-2 0
.largecircle. .largecircle. Example 24 ETM-3 6 .largecircle.
.largecircle. Example 25 HTM-2 ETM-1 5 .largecircle. .largecircle.
Example 26 ETM-2 4 .largecircle. .largecircle. Example 27 ETM-3 6
.largecircle. .largecircle. Example 28 HTM-3 ETM-1 -1 .largecircle.
.largecircle. Example 29 ETM-2 -3 .largecircle. .largecircle.
Example 30 ETM-3 2 .largecircle. .largecircle. Example 31 HTM-4
ETM-1 3 .largecircle. .largecircle. Example 32 ETM-2 3
.largecircle. .largecircle. Example 33 ETM-3 -1 .largecircle.
.largecircle. Example 34 HTM-5 ETM-1 2 .largecircle. .largecircle.
Example 35 ETM-2 -3 .largecircle. .largecircle. Example 36 ETM-3 4
.largecircle. .largecircle. Example 37 HTM-6 ETM-1 2 .largecircle.
.largecircle. Example 38 ETM-2 4 .largecircle. .largecircle.
Example 39 ETM-3 -2 .largecircle. .largecircle. Example 40 HTM-7
ETM-1 2 .largecircle. .largecircle. Example 41 ETM-2 0
.largecircle. .largecircle. Example 42 ETM-3 4 .largecircle.
.largecircle. Example 43 .largecircle. 372 1 HTM-1 ETM-1 1
.largecircle. .largecircle. Example 44 ETM-2 3 .largecircle.
.largecircle. Example 45 ETM-3 2 .largecircle. .largecircle.
Example 46 HTM-2 ETM-1 1 .largecircle. .largecircle. Example 47
ETM-2 1 .largecircle. .largecircle. Example 48 ETM-3 2
.largecircle. .largecircle. Example 49 HTM-3 ETM-1 -1 .largecircle.
.largecircle. Example 50 ETM-2 -3 .largecircle. .largecircle.
Example 51 ETM-3 2 .largecircle. .largecircle. Example 52 HTM-4
ETM-1 1 .largecircle. .largecircle. Example 53 ETM-2 -1
.largecircle. .largecircle. Example 54 ETM-3 3 .largecircle.
.largecircle. Example 55 HTM-5 ETM-1 3 .largecircle. .largecircle.
Example 56 ETM-2 3 .largecircle. .largecircle. Example 57 ETM-3 2
.largecircle. .largecircle. Example 58 HTM-6 ETM-1 2 .largecircle.
.largecircle. Example 59 ETM-2 0 .largecircle. .largecircle.
Example 60 ETM-3 -3 .largecircle. .largecircle. Example 61 HTM-7
ETM-1 2 .largecircle. .largecircle. Example 62 ETM-2 1
.largecircle. .largecircle. Example 63 ETM-3 1 .largecircle.
.largecircle.
[0193] TABLE-US-00002 TABLE 2 Bragg Angle DSC Peak Electric
Characteristic 2.theta. .+-. 0.2.degree. Temp. Number Bright
Potential Peak Evaluation (.degree. C.) (peak) HTM ETM Change (V)
Evaluation Image Fog Comparative example 1 .largecircle. none 0
HTM-1 ETM-1 1 .largecircle. .DELTA. Comparative example 2 ETM-2 3
.largecircle. .DELTA. Comparative example 3 ETM-3 2 .largecircle.
.DELTA. Comparative example 4 HTM-2 ETM-1 1 .largecircle. .DELTA.
Comparative example 5 ETM-2 1 .largecircle. .DELTA. Comparative
example 6 ETM-3 2 .largecircle. .DELTA. Comparative example 7 HTM-3
ETM-1 -1 .largecircle. .DELTA. Comparative example 8 ETM-2 -3
.largecircle. .DELTA. Comparative example 9 ETM-3 2 .largecircle.
.DELTA. Comparative example 10 HTM-4 ETM-1 1 .largecircle. .DELTA.
Comparative example 11 ETM-2 -1 .largecircle. .DELTA. Comparative
example 12 ETM-3 3 .largecircle. .DELTA. Comparative example 13
HTM-5 ETM-1 3 .largecircle. .DELTA. Comparative example 14 ETM-2 3
.largecircle. .DELTA. Comparative example 15 ETM-3 2 .largecircle.
.DELTA. Comparative example 16 HTM-6 ETM-1 2 .largecircle. .DELTA.
Comparative example 17 ETM-2 0 .largecircle. .DELTA. Comparative
example 18 ETM-3 -3 .largecircle. .DELTA. Comparative example 19
HTM-7 ETM-1 2 .largecircle. .DELTA. Comparative example 20 ETM-2 1
.largecircle. .DELTA. Comparative example 21 ETM-3 1 .largecircle.
.DELTA. Comparative example 22 X 232 1 HTM-1 ETM-1 425 X X
Comparative example 23 ETM-2 426 X X Comparative example 24 ETM-3
433 X X Comparative example 25 HTM-2 ETM-1 424 X X Comparative
example 26 ETM-2 427 X X Comparative example 27 ETM-3 431 X X
Comparative example 28 HTM-3 ETM-1 419 X X Comparative example 29
ETM-2 431 X X Comparative example 30 ETM-3 421 X X Comparative
example 31 HTM-4 ETM-1 441 X X Comparative example 32 ETM-2 422 X X
Comparative example 33 ETM-3 433 X X Comparative example 34 HTM-5
ETM-1 424 X X Comparative example 35 ETM-2 422 X X Comparative
example 36 ETM-3 434 X X Comparative example 37 HTM-6 ETM-1 412 X X
Comparative example 38 ETM-2 434 X X Comparative example 39 ETM-3
422 X X Comparative example 40 HTM-7 ETM-1 427 X X Comparative
example 41 ETM-2 424 X X Comparative example 42 ETM-3 427 X X
Comparative example 43 .largecircle. none 0 HTM-1 ETM-1 16 X X
Comparative example 44 ETM-2 11 X X Comparative example 45 ETM-3 18
X X Comparative example 46 HTM-2 ETM-1 21 X X Comparative example
47 ETM-2 19 X X Comparative example 48 ETM-3 16 X X Comparative
example 49 HTM-3 ETM-1 15 X X Comparative example 50 ETM-2 15 X X
Comparative example 51 ETM-3 13 X X Comparative example 52 HTM-4
ETM-1 17 X X Comparative example 53 ETM-2 17 X X Comparative
example 54 ETM-3 16 X X Comparative example 55 HTM-5 ETM-1 11 X X
Comparative example 56 ETM-2 16 X X Comparative example 57 ETM-3 19
X X Comparative example 58 HTM-6 ETM-1 20 X X Comparative example
59 ETM-2 28 X X Comparative example 60 ETM-3 22 X X Comparative
example 61 HTM-7 ETM-1 16 X X Comparative example 62 ETM-2 18 X X
Comparative example 63 ETM-3 14 X X
[0194] TABLE-US-00003 TABLE 3 Bragg Angle DSC Peak Electric
Characteristic 2.theta. .+-. 0.2.degree. Temp. Number Bright
Potential Peak Evaluation (.degree. C.) (peak) HTM ETM Change (V)
Evaluation Image Fog Comparative example 64 .largecircle. none 0
HTM-1 ETM-1 18 X X Comparative example 65 ETM-2 16 X X Comparative
example 66 ETM-3 14 X X Comparative example 67 HTM-2 ETM-1 12 X X
Comparative example 68 ETM-2 12 X X Comparative example 69 ETM-3 13
X X Comparative example 70 HTM-3 ETM-1 16 X X Comparative example
71 ETM-2 15 X X Comparative example 72 ETM-3 17 X X Comparative
example 73 HTM-4 ETM-1 24 X X Comparative example 74 ETM-2 26 X X
Comparative example 75 ETM-3 25 X X Comparative example 76 HTM-5
ETM-1 24 X X Comparative example 77 ETM-2 26 X X Comparative
example 78 ETM-3 28 X X Comparative example 79 HTM-6 ETM-1 21 X X
Comparative example 80 ETM-2 24 X X Comparative example 81 ETM-3 22
X X Comparative example 82 HTM-7 ETM-1 16 X X Comparative example
83 ETM-2 16 X X Comparative example 84 ETM-3 14 X X Comparative
example 85 .largecircle. none 0 HTM-1 ETM-1 2 .largecircle. X
Comparative example 86 ETM-2 3 .largecircle. X Comparative example
87 ETM-3 1 .largecircle. X Comparative example 88 HTM-2 ETM-1 -2
.largecircle. X Comparative example 89 ETM-2 -2 .largecircle. X
Comparative example 90 ETM-3 2 .largecircle. X Comparative example
91 HTM-3 ETM-1 -1 .largecircle. X Comparative example 92 ETM-2 3
.largecircle. X Comparative example 93 ETM-3 4 .largecircle. X
Comparative example 94 HTM-4 ETM-1 4 .largecircle. X Comparative
example 95 ETM-2 2 .largecircle. X Comparative example 96 ETM-3 2
.largecircle. X Comparative example 97 HTM-5 ETM-1 6 .largecircle.
X Comparative example 98 ETM-2 3 .largecircle. X Comparative
example 99 ETM-3 3 .largecircle. X Comparative example 100 HTM-6
ETM-1 5 .largecircle. X Comparative example 101 ETM-2 -2
.largecircle. X Comparative example 102 ETM-3 2 .largecircle. X
Comparative example 103 HTM-7 ETM-1 -2 .largecircle. X Comparative
example 104 ETM-2 3 .largecircle. X Comparative example 105 ETM-3 3
.largecircle. X
Example 64
[0195] A laminated layer photoconductor was constituted as shown
below by preparing a titanyl phthalocyanin crystal in the same
manner as Examples 1 to 21 and using it as a charge generating
agent and using the hole transfer agent (HTM-1) represented by the
formula (22) as a hole transfer agent in Example 64. It was
evaluated in the same manner as Examples 1 to 21 except that
Microline 22N manufactured by Oki Electric, Ltd. as an evaluating
machine in the evaluation of image fogging. The result is shown in
Table 4.
[0196] In addition, the titanyl phthalocyanin crystal used is same
as in Examples 1 to 21, therefore the presentation of the
CuK.alpha. characteristic X-ray diffraction spectrum and the
differential scanning calorimetric analysis chart is omitted. The
manufacturing method of the laminated layer photoconductor of
Example 64 is shown hereinafter.
1. Constitution of Laminated Layer Photoconductor
(1) Intermediate Layer
[0197] 2.5 part by weight of titanium oxide (MT-02 (number-average
primary particle diameter 10 nm) manufactured by Teika, Ltd.) that
was surface-treated with alumina and silica and then with
methyl-hydrogen polysiloxane, 1 part by weight of Amilan CM8000
(made by Toray Inc.) that was a 6, 12, 66, 610 four-dimensional
polymerized polyamide resin, 10 part by weight of methanol and 2.5
part by weight of butanol were received in a paint shaker and then
dispersed for 10 hrs to prepare a coating solution for a
photosensitive layer for intermediate layer.
[0198] The obtained coating solution for the photosensitive layer
was filtered with a 5 .mu.m filter and then applied to an aluminum
drum-type support substrate of 30 mm in diameter and 238.5 mm in
total length as a conductive substrate. Subsequently, it was
heat-treated at 130.degree. C. for 30 min to form an intermediate
layer of 2 .mu.m in film thickness.
(2) Charge Generating Layer
[0199] Next, 1 part by weight of the titanyl phthalocyanin crystal
prepared as a charge generating agent by Example 1, 1 part by
weight of a polyvinyl acetal resin (Eslek KS-5 made by Sekisui
Chemical, Ltd.) being a binder resin, 60 part by weight of
propylene glycol monomethyl ether being a dispersion medium and 20
part by weight of tetrahydrofuran were mixed for 48 hrs and then
dispersed by a ball mill to form a coating solution for a
photosensitive layer for charge generating layer.
[0200] The obtained coating solution for the photosensitive layer
was filtered with a 3 .mu.m filter, then applied onto the
above-mentioned intermediate layer and dried at 80.degree. C. for 5
min to form a charge generating layer of 0.3 .mu.m in film
thickness.
(3) Charge Transfer Layer
[0201] Next, 70 part by weight of the hole transfer agent (HTM-1)
represented by the formula (22), 100 part by weight of a
polycarbonate being a binder resin were mixed and dissolved with
460 part by weight of tetrahydrofuran to prepare a coating solution
for a photosensitive layer for charge transfer layer.
[0202] Next, this coating solution for the photosensitive layer was
applied onto the charge generating layer as the coating solution
for the photosensitive layer for charge generating layer within 60
min after it was prepared, in the same manner. Subsequently, it was
dried at 130.degree. C. for 30 min to form a charge transfer layer
of 20 .mu.m in film thickness. These layers were make into an
electrophotographic photoconductor having a laminated
photosensitive layer as a whole.
[0203] The above-mentioned coating solutions for the photosensitive
layer were stored for 7 days in a closed system of temperature
23.+-.1.degree. C. and relative humidity 50 to 60% RH, next
dispersed again by using a supersonic disperser and then applied,
in the same manner, by the above-mentioned method for constituting
an electrophotographic photoconductor having a laminated
photosensitive layer.
Examples 65 to 70
[0204] Laminated layer photoconductors were constituted and
evaluated in the same manner as Example 64, respectively except
that the hole transfer agents (HTM-2 to 7) shown in Table 2 were
used in Examples 65 to 70 in place of the hole transfer agent
(HTM-1) used in Example 64 in constituting the photoconductors,
respectively. The results are shown in Table 4.
[0205] A titanyl phthalocyanin crystal used is same as in Examples
1 to 21, therefore the description of the CuK.alpha. characteristic
X-ray diffraction spectrum and the differential scanning
calorimetric analysis chart is omitted
Examples 71 to 77
[0206] Laminated layer photoconductors were constituted and
evaluated in the same manner as Examples 64 to 70, respectively in
Examples 71 to 77 except that the titanyl phthalocyanin crystal was
prepared in the same manner as Examples 22 to 42. The results are
shown in Table 4.
[0207] The titanyl phthalocyanin crystal used is same as in
Examples 22 to 42, therefore the presentation of the CuK.alpha.
characteristic X-ray diffraction spectrum and the differential
scanning calorimetric analysis chart is omitted.
Examples 78 to 84
[0208] Laminated layer photoconductors were constituted and
evaluated in the same manner as Examples 64 to 70, respectively in
Examples 78 to 84 except that the titanyl phthalocyanin crystal was
prepared in the same manner as Examples 43 to 63. The results are
shown in Table 4.
[0209] The titanyl phthalocyanin crystal used is same as in
Examples 43 to 63, therefore the presentation of the CuK.alpha.
characteristic X-ray diffraction spectrum and the differential
scanning calorimetric analysis chart is omitted.
Comparative Examples 106 to 112
[0210] Laminated layer photoconductors were constituted and
evaluated in the same manner as Examples 64 to 70, respectively in
Comparative examples 106 to 112 except that the titanyl
phthalocyanin crystal was prepared in the same manner as
Comparative examples 1 to 21. The results are shown in Table 4.
[0211] The titanyl phthalocyanin crystal used is same as in
Comparative examples 1 to 21, therefore the description of the
CuK.alpha. characteristic X-ray diffraction spectrum and the
differential scanning calorimetric analysis chart is omitted.
Comparative Examples 113 to 119
[0212] Laminated layer photoconductors were constituted and
evaluated in the same manner as Examples 64 to 70, respectively in
Comparative examples 113 to 119 except that the titanyl
phthalocyanin crystal was prepared in the same manner as
Comparative examples 22 to 42. The results are shown in Table
4.
[0213] The titanyl phthalocyanin crystal used is same as in
Comparative examples 22 to 42, therefore the description of the
CuK.alpha. characteristic X-ray diffraction spectrum and the
differential scanning calorimetric analysis chart is omitted.
Comparative Examples 120 to 126
[0214] Laminated layer photoconductors were constituted and
evaluated in the same manner as Examples 64 to 70, respectively in
Comparative examples 120 to 126 except that the titanyl
phthalocyanin crystal was prepared in the same manner as
Comparative examples 4.3 to 63. The results are shown in Table
4.
[0215] The titanyl phthalocyanin crystal used is same as in
Comparative examples 43 to 63, therefore the description of the
CuK.alpha. characteristic X-ray diffraction spectrum and the
differential scanning calorimetric analysis chart is omitted.
Comparative Examples 127 to 133
[0216] Laminated layer photoconductors were constituted and
evaluated in the same manner as Examples 64 to 70, respectively in
Comparative examples 127 to 133 except that the titanyl
phthalocyanin crystal was prepared in the same manner as
Comparative examples 64 to 84. The results are shown in Table
4.
[0217] The tithanylphthalocyanine crystal used is same as in
Comparative examples 64 to 84, therefore the description of the
CuK.alpha. characteristic X-ray diffraction spectrum and the
differential scanning calorimetric analysis chart is omitted.
Comparative Examples 134 to 140
[0218] Laminated layer photoconductors were constituted and
evaluated in the same manner as Examples 64 to 70, respectively in
Comparative examples 134 to 140 except that the titanyl
phthalocyanin crystal was prepared in the same manner as
Comparative examples 85 to 105. The results are shown in Table 4.
The titanyl phthalocyanin crystal used is same as in Comparative
examples 85 to 105, therefore the description of the CuK.alpha.
characteristic X-ray diffraction spectrum and the differential
scanning calorimetric analysis chart is omitted. TABLE-US-00004
TABLE 4 Bragg Angle DSC Peak Electric Characteristic 2.theta. .+-.
0.2.degree. Temp. Number Bright Potential Peak Evaluation (.degree.
C.) (peak) HTM Change (V) Evaluation Image Fog Example 64
.largecircle. 296 1 HTM-1 2 .largecircle. .largecircle. Example 65
HTM-2 1 .largecircle. .largecircle. Example 66 HTM-3 0
.largecircle. .largecircle. Example 67 HTM-4 3 .largecircle.
.largecircle. Example 68 HTM-5 4 .largecircle. .largecircle.
Example 69 HTM-6 5 .largecircle. .largecircle. Example 70 HTM-7 2
.largecircle. .largecircle. Example 71 .largecircle. 327 1 HTM-1 2
.largecircle. .largecircle. Example 72 HTM-2 4 .largecircle.
.largecircle. Example 73 HTM-3 3 .largecircle. .largecircle.
Example 74 HTM-4 1 .largecircle. .largecircle. Example 75 HTM-5 0
.largecircle. .largecircle. Example 76 HTM-6 2 .largecircle.
.largecircle. Example 77 HTM-7 -2 .largecircle. .largecircle.
Example 78 .largecircle. 372 1 HTM-1 2 .largecircle. .largecircle.
Example 79 HTM-2 4 .largecircle. .largecircle. Example 80 HTM-3 3
.largecircle. .largecircle. Example 81 HTM-4 1 .largecircle.
.largecircle. Example 82 HTM-5 0 .largecircle. .largecircle.
Example 83 HTM-6 2 .largecircle. .largecircle. Example 84 HTM-7 -2
.largecircle. .largecircle. Comparative example 106 .largecircle.
none 0 HTM-1 1 .largecircle. .DELTA. Comparative example 107 HTM-2
-3 .largecircle. .DELTA. Comparative example 108 HTM-3 2
.largecircle. .DELTA. Comparative example 109 HTM-4 2 .largecircle.
.DELTA. Comparative example 110 HTM-5 0 .largecircle. .DELTA.
Comparative example 111 HTM-6 3 .largecircle. .DELTA. Comparative
example 112 HTM-7 -2 .largecircle. .DELTA. Comparative example 113
X 232 1 HTM-1 62 X X Comparative example 114 HTM-2 61 X X
Comparative example 115 HTM-3 62 X X Comparative example 116 HTM-4
61 X X Comparative example 117 HTM-5 71 X X Comparative example 118
HTM-6 64 X X Comparative example 119 HTM-7 76 X X Comparative
example 120 .largecircle. none 0 HTM-1 16 X X Comparative example
121 HTM-2 19 X X Comparative example 122 HTM-3 11 X X Comparative
example 123 HTM-4 15 X X Comparative example 124 HTM-5 18 X X
Comparative example 125 HTM-6 15 X X Comparative example 126 HTM-7
31 X X Comparative example 127 .largecircle. none 0 HTM-1 12 X X
Comparative example 128 HTM-2 16 X X Comparative example 129 HTM-3
17 X X Comparative example 130 HTM-4 11 X X Comparative example 131
HTM-5 12 X X Comparative example 132 HTM-6 12 X X Comparative
example 133 HTM-7 16 X X Comparative example 134 .largecircle. none
0 HTM-1 2 .largecircle. X Comparative example 135 HTM-2 4
.largecircle. X Comparative example 136 HTM-3 -2 .largecircle. X
Comparative example 137 HTM-4 3 .largecircle. X Comparative example
138 HTM-5 5 .largecircle. X Comparative example 139 HTM-6 -1
.largecircle. X Comparative example 140 HTM-7 0 .largecircle. X
[0219] Here, the mole number of titanium tetrabutoxide and urea
added with respect to 1 mole of o-phthalonitrile and the mole
number of urea in all the examples and comparative examples are
shown in Table 5. TABLE-US-00005 TABLE 5 Titanium Tetrabutoxide
(mole)/ Urea (mole)/ o-Phthalonitrile o-Phthalonitrile (mole)
(mole) Examples 1 to 21 and 0.43 0.22 Examples 64 to 70 Examples 22
to 42 and 0.43 0.56 Examples 71 to 77 Examples 43 to 63 and 0.43
0.82 Examples 78 to 84 Comparative Examples 0.43 0 1 to 21 and
Comparative Examples 106 to 112 Comparative Examples 0.43 0 22 to
42 and Comparative Examples 113 to 119 Comparative Examples 0.43 0
43 to 63 and Comparative Examples 120 to 126 Comparative Examples
0.26 0.56 64 to 84 and Comparative Examples 127 to 133 Comparative
Examples 0.43 2.0 85 to 105 and Comparative Examples 134 to 140
INDUSTRIAL APPLICABILITY
[0220] According to the titanyl phthalocyanin crystal in the
present invention, the storage stability in organic solvents could
be sufficiently improved as compared with the conventional titanyl
phthalocyanin crystal by having a peak at a predetermined Bragg
angle in the CuK.alpha. characteristic X-ray diffraction spectrum
and one peak within a predetermined temperature range in the
differential scanning calorimetric analysis.
[0221] According to the method for preparing the titanyl
phthalocyanin crystal in the present invention, the titanyl
phthalocyanin crystal which is hard to transit the crystal to not
only .alpha.-type but also .beta.-type even in organic solvents was
obtained with significant efficiency and at a low cost by reacting
o-phthalonitrile or its derivative, 1,3-diiminoisoindoline or its
derivative and titanium tetra-butoxide or titanium tetrachloride
above a predetermined temperature in the presence of urea to
prepare the titanyl phthalocyanin crystal.
[0222] Accordingly, it is expected that the electrophotographic
photoconductor using the titanyl phthalocyanin crystal thus
prepared not only improves electric characteristics and image
characteristics in various image forming devices such as copy
machine and printer, etc., but also further makes a considerable
contribution to economical effects.
* * * * *