JP2001302940A - Titanylphthalocyanine compound and electrophotographic photoreceptor using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a titanylphthalocyanine compound which has a high sensitivity, is excellent in electric charge retention and in stability under repeated use, and can be effectively used for printers, facsimiles, and digital copying machines and to provide an electrophotographic photoreceptor prepared by using the same. SOLUTION: This titanylphthalocyanine compound is characterized (1) in that in the light absorption spectrum in the wavelength range of 500-900 nm, the full width at half maximum under vacuum is narrower than that under normal pressure by at least 2 nm or (2) in that the compound emits fluorescent light when irradiated with light having a wavelength of 800 nm and its fluorescent life under vacuum is longer than that under normal pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel titanyl phthalocyanine compound, and more particularly, it can be effectively used for a printer, a facsimile, and a copying machine.
The present invention relates to the production of a photoelectric material exhibiting high sensitivity and low residual potential for semiconductor lasers and LEDs.

[0002]

2. Description of the Related Art Hitherto, phthalocyanine compounds have shown good photoconductivity and have been used, for example, in electrophotographic photoreceptors. In recent years, laser printers that use laser light as a light source instead of conventional white light and have the advantages of high speed, high image quality, and low impact have become widespread, and photoconductors that can meet the demands have been actively developed. It is. In particular, a system using a semiconductor laser as a light source, which has been remarkably developed in recent years, is the mainstream, and the wavelength of the light source is 7
There is a strong demand for a photoreceptor having high sensitivity to long wavelength light of about 80 nm. Under such circumstances, the phthalocyanine compound can be synthesized relatively easily,
Having an absorption peak in a long wavelength region of 600 nm or more,
Research and development have been conducted energetically, since the spectral sensitivity varies depending on the central metal and the crystal form, and there are several publications showing high sensitivity in the wavelength range of semiconductor lasers.

For such purposes, copper phthalocyanine,
Electrophotographic photoreceptors using metal-free phthalocyanine, chloroindium phthalocyanine, chlorogallium phthalocyanine, hydroxygallium phthalocyanine and the like have been reported, but the most frequently reported is titanyl phthalocyanine. JP-A-61-23248, JP-A-62-670943, JP-A-62-27227
JP-A-1-017066, to date,
JP, JP-A-1-082046, JP-A-2-08
JP-A-31243, JP-A-3-035422, JP-A-3-220193, JP-A-4-224873
JP, JP-A-5-017702, JP-A-7-2
Many technical disclosures have been made in, for example, Japanese Patent Application Laid-Open No. 71073.

[0004]

Generally, a phthalocyanine for an electrophotographic photosensitive member has high sensitivity and excellent chargeability, and has little change in sensitivity even in a high-temperature, high-humidity environment and a low-temperature, low-humidity environment, and is used repeatedly. However, the titanyl phthalocyanine described in the above-mentioned patent publication is not yet fully satisfactory. The present invention has been made in view of such conventional problems, and provides a titanyl phthalocyanine compound and an electrophotographic photoreceptor which can be used for an electrophotographic photoreceptor which has high sensitivity and is hardly affected by an external environment and has good repeated use characteristics. To provide.

[0005]

The gist of the present invention resides in a titanyl phthalocyanine compound characterized in that the full width at half maximum of the absorption spectrum in vacuum is at least 2 nm narrower than the full width at half maximum of the absorption spectrum at normal pressure. Another aspect of the present invention resides in a titanyl phthalocyanine compound which emits fluorescence when irradiated with light having a wavelength of 800 nm, wherein the fluorescence lifetime in vacuum is longer than the fluorescence lifetime in normal pressure. . Another aspect of the present invention resides in an electrophotographic photosensitive member having a photosensitive layer containing the above titanyl phthalocyanine compound on a conductive support.

Hereinafter, the present invention will be described in detail. The titanyl phthalocyanine compound of the present invention is different from the titanyl phthalocyanine compound known in each of the above-mentioned publications in the aggregation state of the crystal, and the full width at half maximum of the absorption spectrum in vacuum is 2n more than the full width at half maximum of the absorption spectrum at normal pressure.
m or more, or the fluorescence lifetime in vacuum
It has the feature that it becomes longer than the fluorescence lifetime under normal pressure. Further, it can exhibit extremely high sensitivity to semiconductor laser light and the like.

In the present invention, the above-mentioned absorption spectrum and fluorescence lifetime can be measured by the following methods. The dispersion coating solution of the titanyl phthalocyanine compound of the present invention is applied on a transparent glass substrate. The substrate is held in an optical measurement cryostat that can be evacuated. The absorption spectrum can be obtained by spectroscopically measuring the transmitted light intensity using a xenon lamp, a monochromator, and a photomultiplier tube. Here, the full width at half maximum means a difference between two wavelength points having a half value of the maximum value of the absorption band. Further, in vacuum means a high vacuum of 10 ^-3 mmHg or more, and in normal pressure means under atmospheric pressure (760 mmHg). In each case, the measurement temperature is 24 ° C.

The titanyl phthalocyanine compound of the present invention is characterized in that the full width at half maximum in vacuum is at least 2 nm narrower than the full width at half maximum at normal pressure in the light absorption spectrum in the wavelength range of 500 to 900 nm. Is 5n from the full width at half maximum at normal pressure
It is preferably narrower than m, more preferably narrower than 10 nm.

[0009] The fluorescence lifetime can be calculated from a fluorescence decay curve. The fluorescence decay curve can be obtained by integrating the time-resolved fluorescence spectrum in the wavelength range of 850 nm to 890 nm. The time-resolved fluorescence spectrum is
Femtosecond pulse (pulse width 130 fs, center wavelength 80
It can be obtained by photoexcitation of titanyl phthalocyanine in a cryostat at 0 nm, a spectrum width of 10 nm, and a pulse energy density of 4 pJ / mm ² ) and detecting fluorescence scattered in a 90 ° direction with a streak camera.

[0010] The quantitative evaluation is performed based on the fluorescence lifetime. The shorter the fluorescence lifetime, the faster the fluorescence decay. The fluorescence lifetime can be determined by the following known method. That is, the fluorescence decay curve is model function A ₁ exp (−t
/ τ ₁ ) + A ₂ exp (-t / τ ₂ ). Where t is time,
A ₁ is the amplitude of the fast component, A ₂ is the amplitude of the slow component, τ ₁ is the lifetime of the fast component, and τ ₂ is the lifetime of the slow component. A ₁ ,
τ ₁ , A ₂ and τ ₂ are the parameters of the fit. The fluorescence decay curve of titanyl phthalocyanine is not reproduced by a simpler one-component model function A ₁ exp (−t / τ ₁ ), but can be strictly fitted by the two-component model function described above. With such a fitting, the life of the fast component and the life of the slow component can be obtained.

The titanyl phthalocyanine of the present invention emits fluorescence in all or a part of the wavelength range of 850 to 890 nm when irradiated with light having a wavelength of 800 nm. Is characterized by being longer than the fluorescence lifetime. It is sufficient that the fluorescence lifetime in vacuum is slightly longer than the fluorescence lifetime in normal pressure. Preferably, the fluorescence decay curve is obtained by a model function A ₁ exp (−t / τ ₁ ) + A ₂ exp (− When applied to (t / τ ₂ ), the lifetime of the fast component in vacuum is preferably 5 ps longer than the lifetime of the fast component in normal pressure, more preferably 10 ps.

Particularly preferred as the titanyl phthalocyanine compound according to the present invention having the above characteristics is CuK
In X-ray diffraction using α-rays, a Bragg angle 2θ of 9.6 was obtained.
It is a titanyl phthalocyanine compound having peaks at {± 0.2} and 27.2 {± 0.2}. The basic structure of the titanyl phthalocyanine compound of the present invention is represented by the following general formula.

[0013]

Embedded image

The titanyl phthalocyanine compound contains 5% or less, preferably 3%, of a substrate substituted on the phthalocyanine ring with an alkyl group, an alkoxy group and a halogen atom.
Below, more preferably, it may be contained in the range of 2% or less.

The titanyl phthalocyanine of the present invention can be produced as follows. For example, phthalonitrile and chloronaphthalene are mixed, titanium tetrachloride is added thereto, and the mixture is reacted under a nitrogen atmosphere. Reaction temperature is 12
0-300 ° C, preferably 180-250 ° C, more
90-230 ° C is preferred. Reaction time is 1 to 20 hours,
Preferably, it is 2 to 10 hours, more preferably 2 to 8 hours. After completion of the reaction, dichlorotitanium phthalocyanine can be obtained by hot filtration at a temperature of 100 ° C. or higher, and collecting the precipitate by filtration. The desired titanyl phthalocyanine compound can be obtained by treating this dichlorotitanium phthalocyanine with a basic solid such as sodium carbonate and potassium carbonate and an alcohol solvent such as methanol and ethanol.

Next, an electrophotographic photosensitive member using the titanyl phthalocyanine compound of the present invention as a photoconductive material will be described. In the electrophotographic photoreceptor of the present invention, the photosensitive layer coated on the conductive support may have a single-layer structure or a laminated structure including a charge generation layer and a charge transport layer. Is also good. Also, an undercoat layer may be formed between the conductive support and the photosensitive layer, and a surface protective layer may be provided on the photosensitive layer in a single-layer structure or on a charge transport layer in a laminated structure. good.

The conductive support may be any one that can be used as an electrophotographic photosensitive member. Specifically, for example, a metal drum or sheet of aluminum, copper, nickel, or the like, a laminate of these metal foils, and a vapor-deposited material are exemplified. Further, there may be mentioned plastic films, plastic drums, papers, etc., which have been subjected to a conductive treatment by applying a conductive substance such as metal powder, carbon black, copper iodide and a polymer electrolyte together with a suitable binder. In addition, a conductive sheet or drum containing a conductive material such as metal powder, carbon black, and carbon fiber, or a plastic film having a conductive metal oxide layer such as tin oxide or indium oxide on its surface is used. No.

The undercoat layer is effective for preventing unnecessary charge injection from the conductive support, and has an effect of increasing the charge of the photosensitive layer. Further, it also has the effect of increasing the adhesion between the photosensitive layer and the conductive support. Materials constituting the undercoat layer include aluminum anodic oxide films, aluminum oxide, aluminum hydroxide, titanium oxide, inorganic substances such as surface-treated titanium oxide, polyvinyl alcohol, casein, polyvinylpyrrolidone, polyacrylic acid, celluloses,
Organic layers such as gelatin, starches, polyurethane, polyimide, and polyamide, and other organic zirconium compounds, titanium chelate compounds, titanium alkoxide compounds, organic titanium compounds, silane coupling agents, and the like. The thickness of the undercoat layer is 0.1 to 20 μm
Is most preferable, and the range of 0.1 to 10 μm is most effective.

When the electrophotographic photoreceptor has a laminated structure, the charge generation layer is composed of the titanyl phthalocyanine compound and a binder resin. In the present invention, other charge generating substances may be used in combination with the titanyl phthalocyanine compound. Charge generation substances that can be used in combination are α-type, β-type
And amorphous types such as titanyl phthalocyanine, gallium phthalocyanine, indium phthalocyanine, silicon phthalocyanine, and metal-free phthalocyanine. Further, other than the above phthalocyanine compounds, azo compounds, anthraquinone compounds, perylene compounds,
Examples thereof include a polycyclic quinone compound, a methine squaric acid compound, and the like, but are not limited thereto.

The binder resin can be selected from a wide range of insulating resins. Preferred binder resins include styrene,
Polymers and copolymers of vinyl compounds such as vinyl acetate, vinyl chloride, vinylidene chloride, acrylate, methacrylate, acrylamide, acrylonitrile, vinyl alcohol, ethyl vinyl ether, vinyl pyridine, phenoxy resin, polysulfone, polyvinyl acetal, and polyvinyl Examples include butyral, polycarbonate, polyester, polyamide, polyurethane, cellulose ester, cellulose ether, epoxy resin, silicon resin, alkyd resin, polyarylate, and the like, but are not limited thereto.

The charge generation layer is prepared by dispersing (partially dissolving) the titanyl phthalocyanine compound in a solution in which the binder resin is dissolved in an organic solvent, and preparing a coating solution. And dried. As a method for the dispersion treatment, a known method, for example, a method using a ball mill, a sand grind mill, a planetary mill, a roll mill, a paint shaker, or the like can be used. In that case, the ratio between the titanyl phthalocyanine compound and the binder resin is not particularly limited, but the binder resin is 1 to 1000 parts by weight, preferably 10 to 10 parts by weight, based on 100 parts by weight of the titanyl phthalocyanine compound.
The range is 400 parts by weight. If the ratio of the titanyl phthalocyanine compound is too high, the stability of the coating solution will be reduced, and if it is too low, the residual potential will be high. Therefore, the above composition ratio is appropriate.

Examples of the organic solvent to be used include ethers such as tetrahydrofuran, dioxane, ethylene glycol monomethyl ether, acetone, methyl ethyl ketone,
Ketones such as cyclohexanone, aromatic hydrocarbons such as toluene and xylene, halogenated aromatic hydrocarbons such as monochlorobenzene and dichlorobenzene, halogenated aliphatic hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, dichloroethane, and trichloroethane Alcohols such as methanol, ethanol, and isopropanol; esters such as methyl acetate and ethyl acetate; amides such as N, N-dimethylformamide and N, N-dimethylacetamide; and sulfoxides such as dimethyl sulfoxide.

The coating solution is applied by a coating method such as dip coating, spray coating, spinner coating, bead coating, wire bar coating, blade coating, roller coating, curtain coating, ring coating and the like. be able to. Drying after application is 2
It can be carried out at a temperature of 5 to 250 ° C. for 5 minutes to 3 hours in a stationary or blown state. The thickness of the charge generation layer to be formed is usually in the range of 0.1 to 5 μm.

The charge transporting layer is composed of a charge transporting material, a binder resin, and optionally additives such as an antioxidant. The charge transport materials are generally classified into two types, an electron transport material and a hole transport material, and any of the electrophotographic photoreceptors of the present invention can be used, and a mixture thereof can also be used. As the electron transporting material, a nitro group, a cyano group, an electron withdrawing compound having an electron withdrawing group such as an ester group,
For example, 2,4,7-trinitrofluorenone, 2,4,
Examples include nitrated fluorenone such as 5,7-tetranitrofluorenone, quinones such as tetracyanoquinodimethane, and diphenoquinone.

Examples of the hole transport material include electron-donating organic photoelectric compounds such as carbazole, indole, imidazole, oxazole, thiazole, oxadiazole, pyrazole, pyrazoline, and thiadiazole. , Benzoxazole, benzothiazole, naphthothiazole and other heterocyclic compounds,
Diarylalkane derivatives such as diphenylmethane, triarylalkane derivatives such as triphenylmethane,
Triarylamine derivatives such as triphenylamine,
Phenylenediamine derivatives, N-phenylcarbazole derivatives, diarylethylene derivatives such as stilbene,
A hydrazone derivative, a substituted amino group such as a dialkylamino group or a diphenylamino group, or an electron donating group such as an alkoxy group or an alkyl group, or an electron donating group substituted by an aromatic ring group substituted by these electron donating groups Compounds having the following formula: Further, polymers having a group consisting of the above compound in the main chain or side chain, such as polyvinyl carbazole, polyglycidyl carbazole, polyvinyl pyrene, polyvinyl phenyl anthracene, polyvinyl acridine, and pyrene-formaldehyde resin, may also be used. Specific examples of the charge transport material preferably used below are given below.

[0026]

Embedded image

As the binder resin, the same insulating resin as that used for the charge generation layer described above can be used. Although the ratio of the charge transport material to the binder resin is not particularly limited, it is in the range of 20 to 3000 parts by weight, preferably 50 to 1000 parts by weight, based on 100 parts by weight of the charge transport material. The charge transport layer is prepared by adjusting the coating solution using the same organic solvent as that used for the charge generation layer and the above-described charge transport material and binder resin, and then applying and drying the same method as described above. Can be formed. The thickness of the charge transport layer is usually 5 to 5
A range of 0 μm is appropriate.

When the electrophotographic photosensitive member has a single-layer structure, the photosensitive layer is composed of the titanyl phthalocyanine compound, a charge transport material and a binder resin, and the charge transport material and the binder resin are the same as those in the previous period. Is used. The photosensitive layer may contain various additives such as an antioxidant and a sensitizer as needed. The ratio of the titanyl phthalocyanine compound and the charge transport material to the binder resin is 2 to 300 parts by weight of the binder resin, and the ratio of the titanyl phthalocyanine compound and the charge transport material is 10 parts by weight of the titanyl phthalocyanine compound and the charge transport material. Charge transporting material 0.01 to 100 with respect to 1 part by weight of titanyl phthalocyanine compound
A range of parts by weight is appropriate. After a coating solution is prepared in the same manner as in the previous case, the photosensitive layer is obtained by coating and drying.

[0029]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. Example 1 Phthalodinitrile 97.5 under nitrogen atmosphere
g in 750 ml of chloronaphthalene and then 22 ml of titanium tetrachloride are added dropwise. After the dropwise addition, the temperature was raised, and the mixture was reacted at 200 to 220 ° C. for 5 hours with stirring.
Hot filtration at 00-130 ° C. Further, it was washed with 200 ml of chloronaphthalene heated to 100 ° C. The obtained crude dichlorotitanium phthalocyanine was converted to chloronaphthalene 30.
The mixture was hot-washed with 0 ml and then hot-washed with 300 ml of methanol. Furthermore, 100 g of potassium carbonate and 800 of methanol
The mixture was subjected to a reflux treatment twice for 2 hours at room temperature, filtered, dried, and subjected to X-ray diffraction with respect to CuKα ray.
58.8 g of a titanyl phthalocyanine compound having peaks at 9.6 ° ± 0.2 ° and 27.2 ° ± 0.2 ° of θ were obtained.

FIG. 1 shows absorption spectra of the titanyl phthalocyanine compound produced in Example 1 under vacuum and normal pressure. Here, the absorption spectrum in vacuum is indicated by a solid line, and the absorption spectrum in normal pressure is indicated by a dotted line. According to FIG. 1, the maximum absorption wavelength (500 to 900) of the titanyl phthalocyanine compound produced in Example 1 in vacuum was obtained.
nm range) is 790 nm, and the maximum absorption wavelength at normal pressure (range 500-900 nm) is 794 nm. The full width at half maximum of the absorption spectrum is 2 in vacuum.
08 nm, 232 nm at normal pressure, and 24 nm narrower in vacuum.

The fluorescence decay curves of the titanyl phthalocyanine compound prepared in Example 1 are shown in FIGS. FIG.
Converts the obtained data into a model function [A ₁ exp (-t / τ ₁ ) + A ₂ e
xp (−t / τ ₂ )], where the fluorescence decay curve in vacuum is represented by a large white circle, and the fluorescence decay curve in normal pressure is represented by a small black circle. FIG. 4 shows the contribution of the fast component of the curve fitted by the model function [(A ₁ + A ₂ ) exp (−
t / τ ₁ )], wherein the fluorescence decay curve in vacuum is represented by a solid line, and the fluorescence decay curve in normal pressure is represented by a dotted line. FIG. 5 shows the contribution [A ₂ {exp (−t / τ ₁ ) + exp (−t / τ ₂ )} of the slow component of the curve fitted by the model function, The fluorescence decay curve is shown by a solid line, and the fluorescence decay curve at normal pressure is shown by a dotted line.

The fluorescence decay curves in FIGS. 3-5 show that the decay of fluorescence in vacuum is clearly slower than in normal pressure. Lifetime of fast components in vacuum is 85p
s, the lifetime of the slow component is 184 ps. At normal pressure, the lifetime of the fast component is 72 ps, and the lifetime of the slow component is 175 ps, which are 18% and 5% shorter than those in vacuum, respectively.

Comparative Example 1 Under a nitrogen atmosphere, 97.5 g of phthalodinitrile was added to 750 ml of chloronaphthalene, and 22 ml of titanium tetrachloride were added dropwise. After the dropwise addition, the temperature is raised, and the mixture is reacted at 200 to 220 ° C. for 5 hours with stirring, then allowed to cool, and hot filtered at 100 to 130 ° C. One more
It was washed with 200 ml of chloronaphthalene heated to 00 ° C. The resulting crude dichlorotitanium phthalocyanine was hot-washed with 300 ml of chloronaphthalene, and then methanol 30
The suspension was hot-washed with 0 ml. Then, in 800 ml of NMP
The mixture was repeatedly heated and stirred at 0 to 150 ° C. twice, washed with hot water and washed with methanol, dried and titanyl phthalocyanine.
6 g were obtained. In X-ray diffraction with respect to CuKα ray, Bragg angle 2θ of 9.3 ° ± 0.2 °, 10.6 ° ± 0.2
゜, 13.2 ゜ ± 0.2 ゜, 15.1 ゜ ± 0.2 ゜, 2
It was a titanyl phthalocyanine compound having peaks at 0.8 ± 0.2 ° and 26.2 ± 0.2 °.

FIG. 2 shows absorption spectra of the titanyl phthalocyanine compound produced in Comparative Example 1 under vacuum and normal pressure. Here, the absorption spectrum in vacuum is indicated by a solid line, and the absorption spectrum in normal pressure is indicated by a dotted line. The maximum absorption wavelength (500 to 900 nm) in both vacuum and normal pressure
Is 760 nm, and the full width at half maximum of the absorption spectrum is 178 nm in both vacuum and normal pressure, and there is no difference.

The fluorescence decay curves of the titanyl phthalocyanine compound produced in Comparative Example 1 are shown in FIGS. FIG.
Converts the obtained data into a model function [A ₁ exp (-t / τ ₁ ) + A ₂ e
xp (−t / τ ₂ )], where the fluorescence decay curve in vacuum is represented by a large white circle, and the fluorescence decay curve in normal pressure is represented by a small black circle. FIG. 7 shows the contribution of the fast component [(A ₁ + A ₂ ) exp (−) of the curve fitted by the model function.
t / τ ₁ )], wherein the fluorescence decay curve in vacuum is represented by a solid line, and the fluorescence decay curve in normal pressure is represented by a dotted line. FIG. 8 shows the contribution of a slow component [A ₂ {exp (-t / τ ₁ ) + exp (-t / τ ₂ )}] of the curve fitted by the model function, The fluorescence decay curve is shown by a solid line, and the fluorescence decay curve at normal pressure is shown by a dotted line. In FIGS. 2 and 7, some of the dotted lines do not appear, but this is because they overlap with the solid lines.

When the lifetimes of the fast component and the slow component of the fluorescence decay curve are obtained by the same method as in Example 1, the lifetime of the fast component is 48 ps in vacuum and the lifetime of the slow component is 150 ps in vacuum.
Even under normal pressure, the life of the fast component is 48 ps, and the life of the slow component is also 151 ps. It can be seen that there is no less than 1% difference between the vacuum and the normal pressure.

"Preparation of Electrophotographic Photoreceptor""Example2" 1.6 g of the titanyl phthalocyanine compound produced in Example 1 was added to 30 g of dimethoxyethane, and the mixture was pulverized with a sand grind mill for 2 hours and subjected to fine particle dispersion treatment. . Next, 16 g of dimethoxyethane and 6 g of 4-methoxy-4-methylpentanone-2 were added and diluted, and 0.4 g of polyvinyl butyral (Denka Butyral # 6000C, manufactured by Denki Kagaku Kogyo KK) and phenoxy resin (Union Carbide) (UCAR Co., Ltd., 0.4 g) was mixed with a solution of 7 g of dimethoxyethane to obtain a dispersion. The dispersion was applied on a polyester film on which aluminum was deposited by a wire bar so that the weight after drying was 0.4 g / m ² , and then dried to form a charge generation layer. Next, 5.6 g of the following hydrazone compound (A) and hydrazone compound (B) 1
A solution prepared by dissolving 4 g of the resin and 10 g of a polycarbonate resin (Mitsubishi Chemical Corp., NOVAREX 7030A) in 62 g of THF was applied by an applicator, and a charge transport layer was provided so that the film thickness after drying was 20 μm.

[0038]

Embedded image

[0039]

Embedded image

[0040]

Embedded image

[0041]

Embedded image "Comparative Example 2" An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the titanyl phthalocyanine produced in Comparative Example 1 was used instead of the titanyl phthalocyanine used in Example 1.

[Evaluation] Next, these electrophotographic photoreceptors were mounted on a photoreceptor characteristic measuring apparatus, charged to a surface potential of -700 V, and then irradiated with light of 780 nm, thereby reducing the half-exposure amount. (E1 / 2 sensitivity), the charge retention rate (DDR5) after charging at −700 V for 5 seconds, and the residual potential after removing the 660 nm LED light were measured. The repetition stability was evaluated by the difference (ΔV) between the surface potential after the first time and the surface potential after the 30,000 times repetition of charge-discharge for 30,000 times. Table 1 shows the results.

[0043]

[Table 1]

It can be seen that the titanyl phthalocyanine compound of the present invention has high sensitivity, and is excellent in charge retention and repetition potential stability.

[0045]

As described above in detail, the titanyl phthalocyanine compound of the present invention has high sensitivity, excellent charge retention and excellent repetition stability, as is clear from Table 1, and has been used in printers and facsimile machines. , Which can be effectively used in digital copiers.

[Brief description of the drawings]

FIG. 1 shows an absorption spectrum of a titanyl phthalocyanine compound obtained in Example 1.

FIG. 2 shows an absorption spectrum of the titanyl phthalocyanine compound obtained in Comparative Example 1.

FIG. 3 shows a fluorescence decay curve of the titanyl phthalocyanine compound obtained in Example 1 (the data is represented by a model function [A ₁ exp (−t /
τ ₁ ) + A ₂ exp (−t / τ ₂ )].

FIG. 4 shows the fluorescence decay curve of the titanyl phthalocyanine compound obtained in Example 1 (the contribution of a fast component [(A ₁ + A ₂ ) exp (-t / τ ₁ ) of the curve fitted by the model function)]. Show.

FIG. 5 shows the fluorescence decay curve of the titanyl phthalocyanine compound obtained in Example 1 (the contribution of a slow component [A ₂ ｛exp (-t / τ ₁ ) + exp (-t /
τ ₂ )｝]).

FIG. 6 shows the fluorescence decay curve of the titanyl phthalocyanine compound obtained in Comparative Example 1 (the data was obtained using a model function [A ₁ exp (-t /
τ ₁ ) + A ₂ exp (−t / τ ₂ )].

FIG. 7 shows a fluorescence decay curve of a titanyl phthalocyanine compound obtained in Comparative Example 1 (a contribution of a fast component [(A ₁ + A ₂ ) exp (-t / τ ₁ ) among curves fitted by a model function)]. Show.

FIG. 8 shows the fluorescence decay curve of the titanyl phthalocyanine compound obtained in Comparative Example 1 (the contribution of a slow component [A ₂ ｛exp (-t / τ ₁ ) + exp (-t /
τ ₂ )｝]).

Continuation of the front page (72) Inventor Yutaka Sasaki 1000 Kamoshita-cho, Aoba-ku, Yokohama-shi, Kanagawa Prefecture F-term (reference) 2H068 AA19 BA39 FA13 FB07 FB08 4C050 PA12 4H049 VN05 VP01 VQ60 VQ93 VR52 VU29 VW02

Claims (3)

[Claims] 1. A titanyl phthalocyanine compound having a full width at half maximum in vacuum of at least 2 nm narrower than that at normal pressure in an optical absorption spectrum in a wavelength range of 500 to 900 nm. 2. A titanyl phthalocyanine compound which emits fluorescence when irradiated with light having a wavelength of 800 nm, wherein the fluorescence lifetime in vacuum is longer than the fluorescence lifetime in normal pressure. 3. An electrophotographic photosensitive member having a photosensitive layer containing the titanyl phthalocyanine compound according to claim 1 on a conductive support.