DE3823363A1 - Electrophotographic photoreceptor of titanyl phthalocyanine cpd. - Google Patents

Abstract

Electrophotographic photoreceptor consists of a titanyl phthalocyanine cpd. (I) with main characteristic X-ray peaks, expressed as 2 theta Bragg angle w.r.t. Cu-K alpha (wavelength at 0.1541 nm) at least 9.4 +/- 0.2 deg., 11.7 +/- 0.2 deg., 11.7 +/- 0.2 deg., 15.0 +/- 0.2 deg., 23.5 +/- 0.2 deg., 24.1 +/- 0.2 deg., and 27.3 +/- 0.2 deg. (I) is of the formula (I). X1-4 independently = Cl or Br; n, m, l and k independently = 0-4. The photoreceptor contains (I) as charge generating substance and, as charge transport substance, an amino-arylethene cpd. (II), esp. a 4-amino-styrene deriv. (IIA) of the formulae (II), (IIA): R1-2 = alkyl or aryl; R3-4 = H, halogen or a (substd.)alkyl, aryl, alkoxy or amino gp.; R5 = a (substd.) aryl or heterocyclyl gp.; Ar1 = (substd.)aryl; R6-9 = H, halogen, OH or a (substd.)alkyl, alkoxy, amino or aryl gp.

Description

This invention relates to a photoreceptor for electrophotography and especially one that is used for printers, copiers, etc. is suitable and which has a higher sensitivity to light for longer Wavelengths and semiconductor laser beams as compared to visible light Has.

Electrophotographic photoreceptors with sensitivity to light visible light has been used extensively for copiers, printers, etc. used. As such, electrophotographic photoreceptors have been used in high Dimensions of inorganic photoreceptors on a conductive support a light-sensitive layer containing selenium as the main constituents, Zinc oxide, cadmium sulfide and other inorganic photoconductive substances include, used. In terms of photosensitivity, thermal Stability, water resistance, durability and others for electrophotographic photoreceptors for copiers and others required properties, these are inorganic photoreceptors not always sufficient. For example, selenium tends to crystallize when warming up or getting stained, for example by fingerprints, what the above properties immediately deteriorated. Electrophotographic Photoreceptors that use cadmium sulfide are waterproof and inferior to durability and those who use zinc oxide have problems in durability. Electrophotographic photoreceptors, the selenium and Using cadmium sulfide also have adverse limitations in their manufacture and handling.

To address these problems of inorganic photoconductive substances various organic, photoconductive substances experimental for photosensitive layers of electrophotographic Photoreceptors used. Research and development of this area have been done actively developed lately. For example, an organic photoreceptor that a photosensitive layer containing poly-N-vinylcarbazole and 2,4,7-trinitrofluorenone is used in Japanese Patent Application Laid-Open No. 50-10 496. In terms of sensitivity and durability however, this photoreceptor is not yet sufficient. That's why an electrophotographic photoreceptor with two separate functions  Developed layers, a photosensitive layer consisting of a Charge generation layer and a charge transport layer independently is composed of each other, which is a charge transport substance or Contains charge transport substance. This enables different Substances for the charge generation function and charge transport function to specify independently. Therefore, such substances that have only one function, can be selected from a wide range.

In this way, organic photoreceptors are expected to be high Preserve sensitivity and durability. Lots Charge generation substances for the charge generation layer of electrophotographic photoreceptors with separate functions effective have been suggested. Used as an example of this inorganic substances can be used as in the amorphous selenium Japanese Patent Application Laid-Open No. 43-16198 is. This charge generation layer, which contains the amorphous selenium, becomes in conjunction with a charge transport layer that is an organic Contains charge transport layer used. This amorphous selenium containing charge generation layer has difficulty in Heat to crystallize what is described as above Deterioration in properties results. As examples of the used organic substances as charge generation substances are organic To name dyes or pigments. For example, the ones in the photosensitive layer containing bisazo compounds in the Japanese Laid-Open Patent Specifications Nos. 47-37 543, 55-22 834, 54-79 632, 56-1 16 040, etc. are already known.

Although these bisazo compounds are relatively high Have sensitivity in short and medium wavelength ranges, however, they have a low sensitivity in the long range Wavelengths. It was difficult to use them in laser printers that Use semiconductor laser beam sources and they require high ones Reliability.

The light emitting element of gallium aluminum arsenide (Ga. A. As) type, which is widely used as a semiconductor laser has one oscillating wavelength of more than 750 nm. To electrophotographic Photoreceptors with high sensitivity to light of such a long time  Many studies have been carried out to obtain wavelengths. For example a method has been devised to sensitize agents photosensitive materials such as Se, CdS and others with high Add sensitivity in the range of visible light to the Extend wavelength. As described above, Se and CdS possess however insufficient resistance to temperature, humidity, etc. of the environment. Also a large number of organic photoconductive Materials are known as described above; usually is hers Sensitivity limited to the range of visible light below 700 nm and only a very small number of materials have sufficient Sensitivity for longer wavelengths.

Among them, compounds of the phthalocyanine type are known which have photosensitivity, particularly in the range of long wavelengths. Among them, α- titanyl phthalocyanine is shown in Japanese Patent Laid-Open No. 61-2 39 248. This type of titanyl phthalocyanine has the gloss angle peaks when exposed to X-rays of Cu-K α 0.1541 nm Å at 7.5, 12.3, 16.3, 25.3 and 28.7. However, their sensitivity is low and the electrical potential stability is inferior under continuous load and is sensitive to image fog in electrophotographic processes that use reverse development. Electrification power is also low and it is difficult to obtain a sufficient image density.

As described above, is as an organic charge generation substance or charge carrier-producing substance sensitivity in the range of longer Wavelengths of a phthalocyanine compound available. However, this is in the electrical potential stability problematic in the manufacture or when used continuously as an electrophotographic photoreceptor.

Therefore, the main subject of this invention is a photoreceptor using titanyl phthalocyanine, with high sensitivity especially towards light with a wavelength of more than 600 nm To make available.  

Another object of this invention is a high photoreceptor electrical potential stability for long-term use put.

Another object of this invention is to have a photoreceptor to provide high electrification power. Another The subject of this invention is a photoreceptor suitable for Reverse procedures to provide.

Other objects of this invention will become apparent from the following Description clarifies.

The invention relates to a photoreceptor which contains a titanyl phthalocyanine with the main peaks of the Bragg angles (or gloss angle 2 R of the characteristic Cu-K α X-rays (wavelength 0.1541 nm or 1.541 Å) at least at 9.4 ± 0. 2 °, 11.7 ± 0.2 °, 11.7 ± 0.2 °, 15.0 ± 0.2 °, 23.5 ± 0.2 °, 24.1 ± 0.2 ° and 27, 3 ± 0.2 °.

The drawings illustrate this invention, in which Fig. 1 shows the X-ray diffraction of titanyl phthalocyanine, Figs. 2 and 3 show the X-ray diffraction of two examples of the α- type titanyl phthalocyanine.

Fig. 4 shows the absorption spectrum of the titanyl phthalocyanine according to this invention, Fig. 5 shows the spectral sensitivity of the photoreceptor, Figs. 6, 7, 8, 9, 10 and 11 are cross sections showing examples of the layer composition of the electrophotographic photoreceptor according to the invention .

The numbering in the drawings means the following.

1 : Electrically conductive carrier 2 : Charge generation layer 3 : Landing transport layer 4,4 ', 4'' : Photosensitive layer 5 : Intermediate layer

Titanyl phthalocyanine according to the invention is used as a charge generation substance when a separate function type electrophotographic photoreceptor is used. It forms a photoreceptor in combination with a charge transport substance. The titanyl phthalocyanine according to the invention differs from the type of titanyl phthalocyanine described above. It has an X-ray diffraction spectrum with the main Bragg angular peaks for Cu-K α X-ray radiation 0.1541 nm (error 2 R + 0.2 °) as shown in FIG. 1 at 9.5, 9.7, 11.7, 15 , 0, 23.5, 24.1 and 27.3. Since the Bragg angles of the α- type titanyl phthalocyanine in Cu-K α X-rays are 0.1541 nm, as described above, 7.5, 12.3, 16.3, 25.3 and 28.7, the titanium phthalocyanine has according to the invention a completely different crystal shape as that of type 1.

Titanyl phthalocyanine according to this invention has a particular spectrum which, as described above, is still unknown. The principal Construction is expressed by the following general formula.

(wherein X¹, X², X³ and X⁴ represent Cl and Br and n, m, l and k represent integers from 0 to 4).

The above X-ray diffraction spectra were among the following Conditions measured (which also applies to the later ones).

X-ray tube material: Cu Voltage: 40.0 kV Current: 100.0 mA Starting angle: 6.0 ° End angle: 35.00 ° Angular steps: 0.020 ° Measuring time: 0.50 seconds

The production process of the titanyl phthalocyanine according to the invention is described in the following examples. For example, titanium tetrachloride and phthalonitrile are mixed in α- chloronaphthalene solvent. The dichlorotitanium phthalocyanine (TiCl₂Pc) which forms is hydrolyzed to obtain the α- type titanylphthalocyanine. It is then desirable to work it up with 2-ethoxyethanol, diglyme, dioxane, tetrahydrofuran, N, N-dimethylformamide, N-methylpyrrolidone, pyridine, morpholine, and other solvents that are electron donors.

Then the α- type titanyl phthalocyanine is stirred or ground for a sufficient time by mechanical forces to convert the crystals at a temperature of 50 ° to 180 ° C., preferably at 60 to 130 ° C., and to produce titanyl phthalocyanine according to the invention. As another method of producing the above α- type titanylphthalocyanine, TiCl₂Pc is preferably dissolved in sulfuric acid at a temperature below 5 ° C, or made into sulfate, poured into water or ice water for reprecipitation or hydrolysis.

It is convenient to use the titanyl phthalocyanine obtained as described above Use under dry conditions, but it can also take the form of a wet paste can be used. As a dispersion medium for stirring and Milling can be called those that are usually used for dispersions or emulsifying pigments, etc. are used, such as glass beads, steel beads, Aluminum oxide pearls, flint stone etc. However, it is a disperse medium not always necessary. As an aid to attrition grinding, those who as auxiliaries for the grinding of pigments, such as customary salts, Sodium bicarbonate, Glauber's salt, etc. may be mentioned. However are Tools for friction grinding are not always necessary.

If a solvent is needed for stirring, grinding or attrition , those that are liquid at the stirring or grinding temperature can be used. For example, it is desirable to have more than one of the Solvents such as alcohol type solvents (such as clycerin, Ethylene glycol, diethylene glycol) or solvent from Polyethylene glycol type, ethylene glycol monomethyl ether, Ethylene glycol monoethyl ether and other cellulose type solvents, Ketone type solvents, ester ketone type solvents, etc.  to select.

Typical devices used for crystal inversion processes are common Shakers such as homogenizers, dispersers, shakers, stirrers, Kneaders, Banburry mixers, ball mills, sand mills, grinders, etc.

The temperature range for crystal inversion processes is 50 to 180 ° C, preferably 60 to 130 ° C. As usual in crystalline inversion processes, the Use of nuclei is also effective.

In this invention, other charge generation substances can be used together with the titanyl phthalocyanine described above. Charge generation substances that can be used together with the titanyl phthalocyanine are, for example, α type, β type, γ type, x type, τ type, τ ′ type, and η type and η ′ type, titanyl or non-metallic phthalocyanine. In addition to the above, phthalocyanine pigment, azo pigments, antrachinone pigments, parylene pigments, polycyclic quinone pigments, square acid methine pigments, etc. can be mentioned.

Examples of azo pigments are shown below  

(where is
Ar₁, Ar₂ and Ar₃: substituted or unsubstituted carbocyclic aromatic rings,
R¹, R², R³ and R⁴: an electron-withdrawing group or hydrogen. One of R¹ to R⁴ is an electron-withdrawing group such as a cyano group, etc.
A:

(X is a hydroxy group,

wherein R⁶ and R⁷ are hydrogen or substituted or unsubstituted Are alkyl and R⁸ is substituted or unsubstituted aryl.

Y is hydrogen, halogen atom, substituted or unsubstituted alkyl, alkoxy, carboxyl, sulfo group, substituted or unsubstituted carbamoyl or substituted or unsubstituted sulfamoyl (however, if m is greater than 2, they can be different groups), Z is a group of atoms, necessary to form a substituted or unsubstituted carbocyclic aromatic ring or substituted or unsubstituted heterocyclic aromatic ring, R⁵ is hydrogen, substituted or unsubstituted amino group, substituted or unsubstituted carbamoyl, carboxyl or their ester group, A 'is substituted or unsubstituted aryl, n is an integer from 1 or 2, and m is an integer from 0 to 4.

Compounds of the following can be used as polycyclic quinone pigments general formula (II) may be mentioned. General formula (II):

(In this general formula, X ′ represents a halogen atom, nitro group, cyano group or carboxyl, and n is an integer from 0 to 4.)

Examples are shown below.

In the photoreceptors according to this invention, oxazole derivatives, Oxadiazole derivatives, thiazole derivatives, imidazole derivatives, imidazolone derivatives, Imidazolizine derivatives, bisimidazolizine derivatives, styrene compounds, Hydrazone compounds, pyrazolone derivatives, oxazolone derivatives, Benzothiazole derivatives, benzoimidazole derivatives, quinazoline derivatives, Benzofuran derivatives, acridine derivatives, phenazine derivatives, Aminostilbene derivatives, poly-N-vinylcarbazoles, poly-1-vinylpyrene, poly-9-vinylanthracene, etc. mentioned as used charge transport substances are used when separate function type photoreceptors will.

Generally there is one with a particular one in photoreceptors Charge generating substance not always effective charge transport substance effective with other charge generation substances. Also one with one certain charge transport substance is effective charge generation substance not always effective with other charge transport substances. To them as Using electrophotographic photoreceptors is the right thing to do Combination of charge generation substance and charge transport substance necessary. An unsuitable combination reduces the sensitivity of the electrophotographic photoreceptor, and especially regarding the inadequate discharge efficiency in a weak electrical Field, the residual potential increases. In the worst case, e.g. B. if such an electrophotographic photoreceptor for a duplicator is used, the electrical charge increases with continuous use, and the toner sticks on areas other than the image, stains the background copy or damages the clearly reproduced image.

Therefore, combining a charge generation substance and Charge transport substance important. However, there are no specific ones general rules for selecting such combinations. Finding out a charge transport substance that is suitable for a specific Charge generation substance is difficult.

According to the desired representation of the invention, compounds represented by the following general formula (I), especially for the Suitable object of this invention.  

General formula (I)

(where is
R¹, R²: substituted or unsubstituted alkyl or aryl. Alkyl includes methyl, ethyl, n-propyl, isopropyl, n-butyl, etc. and aryl includes phenyl group, naphthyl, etc. As substituent groups, alkyl such as methyl, ethyl, n-propyl, isopropyl, n-butyl, etc .; Alkoxy such as methoxy, ethoxy, etc .; Aryl such as phenyl; substituted amino group such as dimethylamino, diethylamino, etc .; Hydroxyl group; Halogen atom such as chlorine, bromine, etc. can be called.

As the substituent groups of the above alkyl and alkoxy, halogen atom such as chlorine, aryl such as phenyl, alkenyl such as vinyl group, etc. can be mentioned.
R³, R⁴: hydrogen atom, halogen atom or substituted or unsubstituted aryl, alkyl or amino group. There may be mentioned those exemplified above for R¹ and R². Substituted or unsubstituted alkyl, alkoxy, amino group, aryl, hydroxyl group, halogen atom etc. can be mentioned as substituents and actually those which are given above for R 1 and R 2 as examples.
R⁵: Substituted or unsubstituted aryl or substituted or unsubstituted heterocyclic group.

Phenyl-, naphthyl, anthranil, fluorenyl, etc. can be mentioned as aryl will.

Substituted or unsubstituted alkyl, Alkoxy, aryl, substituted amino group, hydroxyl group, halogen atom, Cyano group, etc. and actually the ones above for R¹ and R² are given as examples.

Ar¹: Substituted or unsubstituted aryl. As aryl, phenyl etc. are called.

Substituted or unsubstituted can be substituted Alkyl, alkoxy, amino group, aryl, hydroxyl group, halogen atom, etc.  are called and actually those that for R¹ and R² as Examples are given).

The inventor mentions that when using the above described Titanyl phthalocyanine compound in photoreceptors as one Charge generating substance, one obtained with excellent properties can be selected by selecting the styrene compounds as Charge transport substance. In other words, when choosing the Charge transport substance, presumably for the reason that the Ionization potential is adapted to that of titanyl phthalocyanine, the Charge slowly from the charge substance into the charge transport substance injected. Therefore, a favorable residual potential, sensitivity Maintain long-term use and charged electrical potential.

Styrene compounds represented by the general formula (I) described above reproduced, have a high phase solubility in high molecular weight binders. Even if the ratio to the high molecular binder increases, neither turbidity occurs Opacity. Therefore the mixing range of the high molecular weight binders are kept very wide and photoreceptors with cheap cargo transport services and properties getting produced. Regarding the high phase solubility, the Charge transport phase uniform and stable. Hence a PR that provides sharp images with high sensitivity and Charge properties free of fog can be obtained. Especially if they are for continuous transfer type electrophotography used, they are not subject to fatigue.

In addition, the charge transfer substances are according to this invention safe, inexpensive in terms of the environment and chemically stable.

As described above, this invention can use high photoreceptors Sensitivity to light of long wavelengths, high stability in the electrical potential for long-term use, high charging capacity and Provide the core optimum for reverse development processes.

It is in the photosensitive layer comprising the photoreceptor desirable that particles of the charge generation substance and the  Charge transport substance are mixed in the binder substance (i.e., dispersed in the layer in the form of pigment). In this case Printing resistance, durability and other properties of the layer improved, storage capacity decreases and the residual potential becomes stable.

Styrene compounds represented by the general formula (I) described above are described are described below.

Compounds represented by the general formula (I) above are compounds are represented by the following general Formula (Ia) are preferred.

(where is
R¹, R², R³, R⁴, R⁵: as defined above,
R⁶, R⁷, R⁸, R⁹: hydrogen atom, halogen atom, hydroxyl group, substituted or unsubstituted alkyl, alkoxy, amino group or aryl.)

As examples of the styrene compounds represented by the general formula (I) above, those of the following structural formulas can be mentioned, although they are not limited to them.

A photosensitive layer of the photoreceptor according to this invention can be composed by providing a layer with the charge generation substances dispersed in the binder on an electroconductive support. Or so-called photosensitive layers of the separate function type, the layer laminar type or the dispersion type can be provided by combining this charge generation substance and charge transport substance. A separate function type photosensitive layer is usually formed as shown in Figs. 6-11. That is, the layer shown in Fig. 6 is composed by forming the charge generation layer ( 2 ) containing titanyl phthalocyanine of the present invention on the electroconductive support ( 1 ) and coating the charge transport layer ( 3 ) containing the charge transport substance around the photosensitive layer ( 4 ) to build. In Fig. 7, the photosensitive layer ( 4 ' ) is formed by reversing this charge generation layer ( 2 ) and charge transport layer ( 3 ). In FIG. 8, the layer is composed by providing an intermediate layer ( 5 ) between the light-sensitive layer ( 4 ) and the electrically conductive carrier ( 1 ) of the layer composition from FIG. 5. In Fig. 9, an intermediate layer ( 5 ) is provided between the photosensitive layer ( 4 ' ) and the electrically conductive support ( 1 ) of Fig. 7 to prevent the introduction of the free electron of the electrically conductive support. In Fig. 10, the layer is composed by forming the photosensitive layer ( 4 '' ) containing the charge generation substances ( 6 ) mainly as titanyl phthalocyanine according to this invention and charge transport substance ( 7 ) combined with this. And in Fig. 11 above, the intermediate layer ( 5 ) between this photosensitive layer ( 4 '' ) and the electrically conductive carrier ( 1 ) is arranged.

When a photosensitive layer is formed from the two-layer composition, a charge generation layer ( 2 ) can be provided by the following methods:

• (a) formed by coating a solution by dissolving the Charge generating substance in a suitable solvent or Adding a binder and mixing, or
• (b) by coating a dispersed solution formed by grinding the charge generating substance into fine particles with a ball mill, a homogenizer, etc. in a disperse medium and addition of a Binder if necessary and mixing and dispersing.

It is possible to obtain uniform dispersions by dispersing of the particles under ultrasonic waves when using this method will.

As a solvent or disperse medium, used to form the Charge generation layer can be n-butylamine, diethylamine, isopropanolamine, Triethanolamine, triethylenediamine, N, N-dimethylformamide, acetone, Methyl ethyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, 1,2-dichloroethane, Dichloromethane, tetrahydrofuran, dioxane, methanol, ethanol, Isopropanol, ethyl acetate, butylestat, dimethyl sulfoxide, etc. called will.

Will a binder to form the charge generation layer or Charge transport layer used, it can be any type, but preferred high molecular polymer; it is desirable that it have the ability a hydrophobic isolated film with a high dielectric constant form. Such polymers are included in the following, but not based on this limited.

• a) polycarbonate
• b) polyester  
• c) methacrylate resin
• d) acrylic resin
• e) polyvinyl chloride
• f) polyvinylidene chloride
• g) polystyrene
• h) polyvinyl acetate
• i) styrene-butadiene copolymer
• j) vinylidene chloride-acrylonitrile copolymer
• k) vinyl chloride-vinyl acetate copolymer
• l) vinyl chloride-vinyl acetate-maleic anhydride copolymer
• m) silicone resin
• n) silicone alkyl resin
• o) phenol formaldehyde resin
• p) styrene alkyd resin
• q) poly-N-vinyl carbazole
• r) polyvinyl butyral
• s) Polycarbonate Z resin

These binders can be used independently or as a mixture of more than two types. The ratio of the charge generation substance to the binder is 10 to 600% by weight, desirably 50 to 400% by weight, and the charge transport substance is desirably 10 to 500% by weight. The thickness of the charge generation layer ( 2 ) formed in this way is preferably 0.01 to 20 μm and particularly preferably 0.05 to 5 μm and the thickness of the charge transport layer is 2 to 100 μm, preferably 5 to 30 μm.

When the above charge generation substance is dispersed by one To form the photosensitive layer, it is preferred that this Charge generating substance has an average particle size of less than 2 µm, preferably less than 1 µm. If the particle size is too big the particles cannot be sufficiently dispersed in the layer and some of the particles may protrude from the surface and deteriorate the surface smoothness. In some cases, discharge may occur protruding particles or toner particles stick there, causing toner coating phenomenon. It is believed that in the charge generation substance, sensitive to light for longer Wavelength (-700 nm), surface charge generated by thermal excitation Charge is neutralized in the charge generation substance and the  Neutralization effect is greater when the particle size is Charge generation substance is larger. Therefore resistance and Sensitivity will only be high if small size particles are made will.

In addition, the photosensitive layer can be one or more types of Contain electron acceptor substances, for the purpose of improving the Sensitivity and reduction of residual potential or fatigue Continuous use. As electron acceptor substances used here succinic anhydride, maleic anhydride, Dibromosuccinic anhydride, phthalic anhydride, Tetrachlorophthalic anhydride, tetrabromophthalic anhydride, 3-nitrophthalic anhydride, 4-nitrophthalic anhydride, Pyromellitic anhydride, melittic anhydride, tetracyanoethylene, Tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, 1,3,5-trinitrobenzene, Paranitrobenzonitrile, picryl chloride, quinone chlorimide. Chloranil, bulmanildichlorodicyanoparabenzoquinone, anthraquinone, Dinitroanthraquinone, 9-fluorenylidene malononitrile, polynitro-9-fluorenylidene malononitrile, Picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, 3,5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-dinitrosalicylic acid, Phthalic acid, mellitic acid, and other compounds with high electron affinity. The ratio of Electron acceptor substance is 100: 0.01 to 200 for Charge generation substance to electron acceptor substance in volume, preferably 100: 0.01 to 100.

Examples of supports ( 1 ) on which the above photosensitive layer is formed are those which are built up by coating, vapor deposition or lamination, such as metal plates, metal drums or made of electrically conductive polymers, indium oxide or other electrically conductive compounds, or electrically conductive thin layers made of aluminum, palladium, gold, etc., on a base such as paper, plastic film, etc. As an intermediate layer, which acts as an adhesive layer or barrier layer, etc., those composed of a high molecular polymer such as the above-mentioned binder resin , Polyvinyl alcohol, ethyl cellulose, carboxymethyl cellulose or other organic high molecular substances or aluminum oxide, etc., can be used.

The photoreceptors according to the invention are, as described above, receive. These have such properties that they are considered Semiconductor laser photoreceptors are optimal because the maximum value of the in of this invention used titanyl phthalocyanine in the photosensitive wavelength range of 817 nm + 5 nm and that Titanyl phthalocyanine has a very stable crystal form, so that conversion is difficult to reach in other crystal forms. These properties are advantageous for the production and application of electrophotographic Photoreceptors.

With this invention, photoreceptors can be optimized Light sensitivity in the range of light with medium wavelengths and especially semiconductor lasers and LEDs can be obtained using the original titanyl phthalocyanine according to the invention. The Titanyl phthalocyanine according to this invention is excellent in Crystal stability to food, heat and mechanical forces and has high sensitivity as photoreceptor, chargeability and electrical potential stability.

Examples of this invention are described below with reference to the examples. Titanyl phthalocyanine according to this invention and α- type titanyl phthalocyanine are described first.

Production Example 1

10 parts of α- type titanyl phthalocyanine, 5 to 20 parts of a conventional salt such as a friction grinding aid and 10 parts of polyethylene glycol as a dispersing agent were placed in a sand mill and ground at a temperature of 60 to 120 ° C. for 7 to 15 hours. After this time, grinding at high temperatures enables the β- crystal form and decomposition to be shown. The compound was removed from the kettle, the grinding aid and dispersion medium were removed with water and methanol, and the compound was purified in 2% dilute aqueous sulfuric acid solution, filtered, washed with water and dried. A clear, green-blue crystal was obtained. As shown in Fig. 1 as a result of X-ray diffraction and infrared spectroscopic analysis, the crystal was recognized as the titanyl phthalocyanine of the present invention.

The infrared absorption spectrum was shown in Fig. 4. The maximum wavelength ( λ _max. Of the absorption spectrum is 817 ± 5 nm, difference to λ _max. = 830 nm of the α- type titanyl phthalocyanine.

Production Example 2

A mixture of 40 g of phthalonitrile, 18 g of titanium tetrachloride and 500 ml of α- chloronaphthalene was heated for 3 hours at a temperature of 240 to 250 ° C in a nitrogen stream and stirred until the reaction was complete. Then the mixture was filtered and dichlorotitanium phthalocyanine was obtained as a product. A mixture of this dichlorotitanium phthalocyanine and 300 ml of undiluted ammonia water was heated and refluxed for 1 hour, and 18 g of the desired titanyl phthalocyanine was obtained. The product was sufficiently washed with acetone in a Soxhlet extractor. The product was α- type titanyl phthalocyanine as shown in FIG .

Production Example 3

The titanyl phthalocyanine of Comparative Example 2 was prepared by acid paste. Α- type titanyl phthalocyanine with a spectrum as shown in Fig. 3 was obtained.

example 1

1 part of the titanyl phthalocyanine according to the invention as in Production Example 1 shown, 1 part of the dispersion binder resin, Polyvinyl butyral resin (XYHL - manufactured by Union Carbide) and 100 parts Tetrahydrofuran was 15 minutes with an ultrasonic disperser dispersed. The dispersion solution obtained was subjected to an electric conductive carrier composed of a polyester film coated with aluminum, deposited with a lead wire to the Form charge generation layer with a thickness of 0.2 microns.

On the other hand, 3 parts of the connection were made with the following Structure and 4 parts polycarbonate resin (Panlite L-1250) manufactured by Teÿin Chemical) dissolved in 30 parts of 1,2-dichloroethane, one obtained Solution was applied to the charge generation layer described above  deposited and dried to form a charge transport layer To form a thickness of 18 microns. In this way, the electrophotographic Photoreceptor formed in accordance with this invention.

Example 2

An electrophotographic photoreceptor, the same as in Example 1, except that the charge transport substance of the following structure was used in place of that of Example 1, was formed. As shown in Fig. 5, the spectral distribution was good in the long wavelength range.

Comparative Example 1

A photoreceptor used for comparison was prepared as in Example 1, except that a discharge generating substance (that in Synthesis Example 2) with an X-ray diffraction spectrum as in Fig. 2 was used.

Comparative Example 2

A photoreceptor ( 2 ) as in Example 1 was formed, except that a discharge generation substance (that from Synthesis Example 3) with an X-ray diffraction spectrum as in Fig. 3 was used as the charge generation substance.

Example 3

An intermediate layer with a thickness of 0.1 µm, composed of Vinyl chloride, vinyl acetate-maleic anhydride copolymer (SLEC NF-10, manufactured by Sekisui Chemical) was based on the polyester Aluminum foil was deposited, formed.

As the charge generation material (CGM), the present invention Titanyl phthalocyanine ground with a ball mill for 24 hours, 1,2-dichloroethane solution containing 6% by weight polycarbonate resin (Panlite L-1250, Teÿin Chemical) was added until the ratio of Titanyl phthalocyanine to polycarbonate resin 30 to 100 (weight ratio) and the connection was made using a ball mill for 24 hours dispersed. 75% by weight, based on the Polycarbonate resin charge transport material (CTM) (Compound 1) added and compound made to monochlorobenzene / 1,2-dichloroethane in 3/7 To obtain (volume ratio) on the intermediate layer described above applied by spraying to a photoreceptor layer with a thickness of 20 µm, and thus a sample of the photoreceptor obtained according to this invention.

Example 4

An exactly the same intermediate layer as in Example 1 was applied to one Polyester film coated with aluminum foil.

Then a 1,2-dichloroethane solution containing 16.5% by weight of CTM (Compound 2) / polycarbonate resin (Panlite L-1250, Teÿin Chemical) im 60/100 ratio (weight ratio) to that described above Intermediate layer brought by immersion, and dried to a To obtain charge transport layer (CTL) with a thickness of 15 microns. Then, as a CGM, titanyl phthalocyanine according to the invention was used for 24 hours ground in a ball mill, 1,2-dichloroethane solution, containing 6% by weight Polycarbonate resin (Panlite L-1250, Teÿin Chemical) was added until the ratio of titanyl phthalocyanine to polycarbonate resin 30/100 (Weight ratio), and the connection was with 24 hours dispersed in a ball mill. 75% by weight was added to this dispersion solution based on the polycarbonate resin CTM (compound) added and  Monochlorobenzene was used up to a monochlorobenzene / 1,2-dichloroethane ratio of 3/7 (volume ratio) also added, this was on applied the intermediate layer described above by spraying to a to produce a light-sensitive layer with a thickness of 5 µm. To this A sample of the photoreceptor according to this invention was obtained.

Each photoreceptor obtained in this way was on a electrostatic tester, "EPA-8100" (manufactured by Kawaguchi Denki Seisakusho) applied and characteristic test was as follows carried out.

Electrophotographic properties were tested using a model SP-428 electrometer (manufactured by Kawaguchi Denki Seisakusho) by measuring the electrical potential pickup, VA (volts) when the photoreceptor surface had a charging voltage of -6K or + 6K volts in 5 seconds, light irradiation E 1/2 (lux, second) required to weaken the electrical potential V ₁ (start of electropotential volt) after dark attenuation to 1/2 and dark attenuation ratio (DD = (VA - V ₁) / V ₁ × 100 (%) in 5 seconds ).

Next, after loading the photosensitive layer through Glow discharge in 5 seconds was a voltage of -6KV or + 6KV to the charged electricity, this was left for 5 seconds (the electrical potential of this time becomes the initial electrical potential called). Then the light from a xenon lamp was in the spectral units split so that the light intensity on the photoreceptor surface 5erg / cm² · sec. It was light with a wavelength of 780 nm blasted and exposure to weaken the electrical Initial potential from +600 or -600 volts to +300 or -300 volts, (erg / cm²) was measured.

The result is shown in Table 1 below.  

Table 1

It can be seen from the above results that the invention PR in sensitivity to long wavelengths in the Electron potential stability with long-term use and in charging capacity is outstanding.

Next is an example of application in reverse development described.

Six types of photoreceptors used in Examples 1 to 4 and Comparative Examples 1 and 2 were described on a modified laser printer LP-3010 (manufactured by Konishiroku Photo Industry) by reverse development using a Two-component developer containing plus or minus toner for plus or minus charge, pictures were created by repeating them 1000 times, the density of each image and black dots on a white background divided into three levels, "○", "∆", and "×". The result is in the shown in Table 2 below. As a light source, a Semiconductor laser (780 nm) and LED (680 nm) used.  

Table 2

The amount of black dots was classified as follows:
: 0 pc / cm²
○: less than 3 pcs / cm²
×: more than 3 pcs / cm²
Image density was measured using a Sakura Dencitometer, Model PDA-65.
: Reflection density greater than 1.0
○: reflection density 0.6 to 1.0
×: reflection density less than 0.6
As described above, it can be seen that the photoreceptor according to this invention is ideal for reverse development.

Examples 5 to 12

A portion of titanyl phthalocyanine according to this invention in Production Example 1, dispersion binder resin, one part Polyvinyl butyral resin ("XYHL" manufactured by Union Carbide) and 100 parts  Tetrahydrofuran were analyzed using a Ultrasonic dispersion device dispersed. The dispersion solution obtained was on an electrically conductive carrier consisting of a Polyester film coated with aluminum, applied with a wire rod, to produce a charge generation layer with a thickness of 0.2 µm.

On the other hand, three parts were as in the table below 3 connection shown (charge transport substance and four parts Polycarbonate resin "Panlite L-1250" manufactured by Teÿin Chemical) in 30 Parts of 1,2-dichloroethane dissolved, the one described above The charge generation layer was coated with the solution obtained, dried to a charge transport layer with a thickness of 19 microns form, and in this way became an electrophotographic photoreceptor made according to this invention.

Comparative Example 3

It became an electrophotographic photoreceptor, the same as in Example 5, formed, except that a charge transport substance the following structure was used instead of that in Example 1.

Comparative Example 4

An electrophotographic photoreceptor was made the same as in Example 5, except that a charge transport substance of the following structure was used instead of that in Example 5. In the spectral distribution of this photoreceptor, the sensitivity to long wavelengths was as shown in Fig shown. 5, good.

Comparative Example 5

A comparative photoreceptor was prepared in the same manner as in the example, except that a charge generation substance (that from Production Example 2) with the X-ray diffraction spectrum as shown in Fig. 2 was used as the charge generation substance.

Comparative Example 6

A comparative photoreceptor was prepared in the same manner as in the example, except that a charge generation substance (that from Production Example 3) with the X-ray diffraction spectrum as shown in Fig. 3 was used as the charge generation substance.

Example 13

An intermediate layer with a thickness of 0.1 µm composed of Vinyl chloride-vinyl acetate-maleic anhydride copolymer (SLEC MF-10, Sekisui Chemical) was made of polyester coated with aluminum foil educated.

Then, as the charge generation material (CGM), the invention became Titanyl phthalocyanine ground with a ball mill for 24 hours, 1,2-dichloroethane solution, containing 6% by weight polycarbonate resin (Panlite L-1250, Teÿin Chemical) was added so that the ratio of Titanyl phthalocyanine to polycarbonate resin 30 to 100 (volume ratio) and the compound was ball-milled for 24 hours dispersed. In this dispersion solution Charge transport substance solution of 75 wt .-% based on the Polycarbonate resin added as shown in Table 1 below and adjusted to monochlorobenzene / 1,2-dichloroethane = 3/7 (volume ratio) to get this was through on the intermediate layer described above Spray applied to a photoreceptor with a thickness of 20 µm to produce, and in this way a sample of the invention Get PR.  

Example 14

An exactly the same intermediate layer as in Example 1 was on the polyester film coated with aluminum foil.

Then 1,2-dichloroethane solution containing 16.5% by weight of the Charge transport substance / polycarbonate resin (Panlite L-1250, Teÿin Chemical) in a ratio of 60/100 (weight ratio) as in Table 3 below shows the intermediate layer described above applied by immersion, and dried to a To obtain charge transport layer (CTL) with the thickness of 15 microns.

Then, as CGM, titanyl phthalocyanine according to this invention was made with milled in a ball mill for 24 hours, containing 1.2 dichloroethane solution 6 wt .-% polycarbonate resin (Panlite L-1250, Teÿin Chemical) was added so that the ratio of titanyl phthalocyanine to Polycarbonate resin was 30 to 100 (weight ratio), and the Compound was dispersed with the ball mill for 24 hours. These Dispersion solution was with the charge transport substance as in the following Table 3 in 75 wt .-% added to the polycarbonate resin. Continue monochlorobenzene was added and adjusted so that the ratio Monochlorobenzene to 1,2-dichloroethane was 3 to 7 (volume ratio), this was applied to the CTL described above by spraying to form a 5 µm thick CGL, and in this way the Obtained photoreceptor according to this invention.

Fourteen kinds of photoreceptors of Examples 5 to 14 and Comparative Examples 3 to 6 were applied to a modified LP-3010 laser printer (product of Konica Corporation), and differences between the electric potential in the unexposed part (V _H ) and the exposed part (V _L ) at the starting point and the values after copying 10,000 times, Δ | V _H | or Δ | V _L | were measured.

Assuming that the exposure required to reduce the electrical charging potential from +600 V to +300 V is I ₀ (erg / cm²), we assume:

got calculated.
A semiconductor laser (oscillating wavelength: 700 nm) was used as the light source.

The formula of each photoreceptor and the result of the measurement are in the shown in the following table.

Table 3

The electrophotographic photoreceptor, which is a charge generation substance and uses a charge transport substance according to this invention, has a high sensitivity to long wavelengths, Charging capacity and stability of the electrical potential when used continuously, provides clear images without fog.  

On the other hand, the sensitivity drops in the comparison samples and loading capacity significantly, image density drops and fog occurs Continuous use. Suitable examples of reverse development processes will be shown below.

Photoreceptors of Examples 5 and 6 and Comparative Examples 3 and 4 were on a modified laser printer LP-3010 (Konishiroku Photo Industrie) applied the reverse development using a two component developer containing plus or Minustoner at plus or minus charge, the picture was taken at Repeated 1000 times, image density and the amount of black dots on a white background were rated as, ○ and ×. The results are shown in Table 2. As a light source, a Semiconductor laser (780 nm) and LED (680 nm) used.

Table 4

The amount of black dots was classified as follows:
: 0 pc / cm²
○: less than 3 pc / cm²
×: larger than 3 pc / cm²
Image density was measured using a Sakura Dencitometer, Model PDA-65.
: Reflection density greater than 1.0
○: reflection density 0.6 to 1.0
×: reflection density less than 0.6
From the above it can be seen that the photoreceptor according to this invention is suitable for reverse development.

Claims (4)

1. Photoreceptor for electrophotography comprising a titanyl phthalocyanine compound, which is expressed as characteristic X-ray main peaks expressed as 2 R Bragg angle based on Cu-K α (wavelength at 0.1541 nm) at least at 9.4 ± 0.2 °, 11.7 ± 0.2 °, 11.7 ± 0.2 °, 15.0 ± 0.2 °, 23.5 ± 0.2 °, 24.1 ± 0.2 ° and 27.3 ± 0.2 °. 2. The photoreceptor of claim 1, wherein the titanyl phthalocyanine has the following formula: (wherein X¹, X², X³ and X⁴ each represent a chlorine atom or a bromine atom; and n, m, l and k are each integers from 0 to 4). 3. Photoreceptor for electrophotography, comprising an electrically conductive support and a light-sensitive layer applied thereon, containing a titanyl phthalocyanine compound, which is expressed as characteristic main X-ray peaks expressed as 2 R Bragg angle based on Cu-K α (wavelength 0.1541 nm) at least at 9 , 4 ± 0.2 °, 11.7 ± 0.2 °, 11.7 ± 0.2 °, 15.0 ± 0.2 °, 23.5 ± 0.2 °, 24.1 ± 0, 2 ° and 27.3 ± 0.2 °, as a charge generation substance, and a compound having the formula (I) as a charge transport substance; (wherein R¹ and R² independently represent an alkyl group or an aryl group, each of which may have a substituent; R³ and R⁴ independently represent a hydrogen atom, a halogen atom or an alkyl group, an aryl group, an alkoxy group or an amino group, with the proviso that each group may have a substituent; R⁵ represents an aryl group or heterocyclic group, each of which groups may have a substituent; and Ar¹ represents a substituted or unsubstituted aryl group). 4. The photoreceptor according to claim 3, wherein the compound is a formula represented by (Ia), (wherein R¹, R², R³, R⁴ and R⁵ independently represent the same atom or group as in formula (I); and R⁶, R⁷, R⁸ and R⁹ each represents a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an alkoxy group , represent an amino group or an aryl group, with the proviso that these groups may have a substituent).