JP4967590B2 - Phthalocyanine crystal and electrophotographic photosensitive member, electrophotographic photosensitive member cartridge and image forming apparatus using the same - Google Patents

Description

  The present invention is a phthalocyanine crystal that is very effective for LED light and semiconductor laser light, has high sensitivity and is excellent in stability against dispersion, and an electrophotographic photosensitive member, an electrophotographic photosensitive member cartridge using the phthalocyanine crystal, and The present invention relates to an image forming apparatus.

  In recent years, the electrophotographic technique is widely applied not only to the field of copying machines but also to various printers and printing machines because it is excellent in immediacy and provides high-quality images.

  As a photoreceptor that is the core of electrophotographic technology, a photoreceptor using an inorganic photoconductive material such as selenium, an arsenic-selenium alloy, and zinc oxide has been used, but recently, it is pollution-free. Photoconductors using organic photoconductive materials, which have advantages such as easy film formation / manufacturing and high freedom of material selection / combination, are the mainstream.

  The sensitivity of an electrophotographic photoreceptor using an organic photoconductive material varies depending on the wavelength of exposure light and the type of charge generating material. As a charge generation material having sensitivity to light having a long wavelength of 600 to 800 nm, a phthalocyanine compound has attracted attention. Among phthalocyanine compounds, researches on metal-containing phthalocyanines such as chloroaluminum phthalocyanine, chloroindium phthalocyanine, oxyvanadyl phthalocyanine, hydroxygallium phthalocyanine, chlorogallium phthalocyanine, magnesium phthalocyanine, and oxytitanyl phthalocyanine, or metal-free phthalocyanine, etc. Has been done.

  Regarding phthalocyanine compounds, it has been reported that even if the monomolecular structure is the same, the charge generation efficiency differs depending on the arrangement order (crystal type) of crystals that are aggregates of single molecules (non-patent literature). 1 and 2).

  With the recent increase in the speed of the electrophotographic process, it is essential to increase the sensitivity and the response speed as the characteristics of the electrophotographic photosensitive member, and it is essential to develop a charge generation material with higher sensitivity.

  For high sensitivity, a charge generation material having a high charge generation capability is essential. Among them, active research has been conducted on oxytitanyl phthalocyanine, which is highly sensitive to LD exposure, which is currently the mainstream. The oxytitanyl phthalocyanine is known to have a crystal polymorphism. Known crystal types include α-type (see Patent Literature 1), β-type (see Patent Literature 2), C-type (see Patent Literature 3), D-type (see Patent Literature 4), and Y-type (see Patent Literature 5). ), M type (refer to Patent Document 6), M-α type (refer to Patent Document 7), and I type (refer to Patent Document 8) have been reported.

  Among these crystal types, a crystal type showing a main diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.2 ° with respect to CuKα characteristic X-ray (wavelength 1.541Å) shows high quantum efficiency and high sensitivity. It is known to show.

  In addition, the phthalocyanine crystal type showing a main diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.2 ° with respect to CuKα characteristic X-ray (wavelength 1.541Å) is a crystal other than a crystal composed only of an oxytitanylphthalocyanine molecule. In addition, it is widely known that a mixed crystal composed of oxytitanyl phthalocyanine and other phthalocyanines or other pigments forms a similar crystal form and exhibits high sensitivity (see Patent Document 9).

Journal of Electrophotographic Society, Vol. 29, No. 3, pp. 250-258 Journal of Electrophotographic Society, Vol. 32, No. 3, pp. 282-289 JP-A-61-217050 JP-A 62-67094 JP-A-63-366 JP-A-2-8265 JP 63-20365 A JP-A-3-54265 JP-A-3-54264 Japanese Patent Laid-Open No. 3-128973 Japanese Patent Laid-Open No. 3-9962

  Phthalocyanine crystal showing a main diffraction peak at 27.2 ° Bragg angle (2θ ± 0.2 °) with respect to these CuKα characteristic X-rays (wavelength 1.541Å) (hereinafter referred to as “phthalocyanine crystal” is only a single kind of phthalocyanine) In addition to crystals composed of the above, all crystals including phthalocyanine, including mixed crystals composed of a plurality of types of phthalocyanines and mixed crystals composed of phthalocyanines and other molecules, are mainly amorphous. Phthalocyanine or low crystalline phthalocyanine as a precursor is brought into contact with a specific compound to convert the crystal form. In this crystal conversion process, a crystal form is constructed by the interaction between a specific compound molecule and phthalocyanine. At this time, the interaction with phthalocyanine differs depending on the type of the specific compound used, and there are various types depending on the manufacturing method and manufacturing route. Shows crystal type and particle shape. In addition, the characteristics of electrophotographic photoreceptors such as charge generation capability (sensitivity), chargeability and dark decay also depend on the manufacturing method and manufacturing route, and it is very difficult to predict the performance in advance. is there.

  Moreover, the crystal form of the phthalocyanine crystal showing a main diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.2 ° with respect to CuKα characteristic X-ray (wavelength 1.541Å) is a metastable crystal type, and heat, compound There is a problem that the crystal form is rearranged to a more stable stable crystal form due to contact with or physical force, and sensitivity is lowered. The stability of these crystals also depends on the production method and production route as described above, and it is very difficult to predict the stability from the stage before production and to produce it.

  Thus, the phthalocyanine crystal showing the main diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.2 ° with respect to the CuKα characteristic X-ray (wavelength 1.541Å) is high in sensitivity but inferior in crystal stability. It has a problem.

  As current copying machines, laser printers, and plain paper fax machines increase in speed, more sensitive and stable charge generating materials are widely desired. However, as described above, it is very difficult to predict the characteristics and stability of phthalocyanine crystals obtained by the production method and production route. Therefore, a phthalocyanine crystal having a main diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.2 ° with respect to CuKα characteristic X-ray (wavelength 1.541Å), which is a more sensitive and stable phthalocyanine crystal Has not been developed yet.

  The present invention has been made in view of the above background. That is, an object of the present invention is a phthalocyanine crystal having a main diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.2 ° with respect to CuKα characteristic X-rays (wavelength 1.541Å), which is highly sensitive and stable. Another object of the present invention is to provide a phthalocyanine crystal having excellent properties, and to provide an electrophotographic photosensitive member, an electrophotographic photosensitive member cartridge, and an image forming apparatus that can be used stably with high sensitivity.

  The present inventors presume that the compound used in the above-mentioned crystal conversion step is deeply involved in the crystal stability of the obtained phthalocyanine crystal and the sensitivity as a charge generation material, and intensively studied to solve the above problems. As a result, it was found that the phthalocyanine crystal obtained by contacting with a specific fluorinated aromatic compound exhibits high sensitivity and is excellent in stability. Further, by using this phthalocyanine crystal for an electrophotographic photoreceptor, it has been found that an electrophotographic photoreceptor, an electrophotographic cartridge and an image forming apparatus that can be used with high sensitivity and stability can be obtained, and the present invention has been completed. It was.

That is, the gist of the present invention is a phthalocyanine crystal having a main diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.2 ° with respect to CuKα characteristic X-ray (wavelength 1.541Å), which is directly bonded to an aromatic ring. It has a fluorine atom to, and, on the aromatic compound having a substituent group substituent constant σm by Hammett rule is 0.48 or less, resulting et been through the step of contacting a phthalocyanine crystal precursor, aromatic compounds The substituent that is present is a halogen atom other than a fluorine atom, and the phthalocyanine crystal contains oxytitanyl phthalocyanine (claim 1).

Another gist of the present invention resides in an electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the photosensitive layer contains the phthalocyanine crystal described above ( Claim 2 ).

Another subject matter of the present invention is an electrophotographic photosensitive member comprising the above-described electrophotographic photosensitive member and a cartridge case that detachably supports the electrophotographic photosensitive member with respect to an image forming apparatus. It exists in a body cartridge (Claim 3 ).

Another gist of the present invention is the above-described electrophotographic photosensitive member, a charging unit that charges the electrophotographic photosensitive member, and an exposure unit that exposes the charged electrophotographic photosensitive member to form an electrostatic latent image. , characterized by comprising a developing unit for developing an electrostatic latent image formed on the electrophotographic photosensitive member, it lies in the image forming apparatus (claim 4).

  When used as a charge generation material, the phthalocyanine crystal of the present invention exhibits higher sensitivity than a known phthalocyanine crystal and has good crystal stability. Further, by using this phthalocyanine crystal, it is possible to provide an electrophotographic photosensitive member, an electrophotographic cartridge, and an image forming apparatus that can be used with high sensitivity and stability.

  Hereinafter, the present invention will be described in detail, but the present invention is not limited to the following description, and various modifications can be made within the scope of the gist of the present invention.

[I. Phthalocyanine crystal]
The phthalocyanine crystal of the present invention has a crystal form showing a main diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.2 ° with respect to CuKα characteristic X-ray (wavelength 1.541Å) (hereinafter referred to as “specific crystal type”). In some cases, the phthalocyanine crystal is obtained through a step of bringing a phthalocyanine crystal precursor into contact with a fluorinated aromatic compound having a specific substituent.

[I-1. Fluorinated aromatic compound]
The compound used for obtaining the phthalocyanine crystal of the present invention has a fluorine atom directly bonded to an aromatic ring, and a substituent having a substituent constant σm of 0.48 or less in Hammett's rule It is.

  Hammett's rule is an empirical rule used to explain the effect of substituents on aromatic compounds on the electronic state of the aromatic ring. The value of the substituent constant σm of the substituted benzene is 0 in the case of a hydrogen atom, and becomes a large positive value as the electron withdrawing property increases and becomes a negative large value as the electron donating property increases. Therefore, by using this substituent constant σm, it becomes possible to predict and express the electronic state and electron density of the aromatic compound having a substituent. As for typical substituents, substituent constants σm of substituted benzenes according to Hammett's rule described in “Chemical Handbook Basic Edition II Revised 4th Edition” edited by The Chemical Society of Japan (September 30, 1993, published by Maruzen Co., Ltd.) Table 1 shows the values.

  In the present invention, a fluorinated aromatic compound having a substituent having a substituent constant σm of 0.48 or less is used. When a fluorinated aromatic compound having no substituent having a substituent constant σm of 0.48 or less is used, the stability of the crystal with respect to operations such as dispersion of the resulting phthalocyanine crystal is lowered, and the sensitivity may be lowered accordingly. is there. Especially, it is preferable that this substituent constant (sigma) m is 0.45 or less, and it is preferable that the substituent which the fluorinated aromatic compound used in this invention has is 0.43 or less. The lower limit of the substituent constant σm is not particularly limited, but is usually −0.1 or more.

  Examples of substituents having a substituent constant σm of 0.48 or less include ketone groups such as acetyl groups; halogen atom groups such as chloro groups and bromo groups; aryl groups such as phenyl groups and naphthyl groups; methyl groups and ethyl groups Alkyl groups such as isopropyl group and cyclohexyl group; thioalkyl groups such as thiomethyl group; alkoxy groups such as methoxy group and ethoxy group; ester groups such as methyloxycarbonyl group and ethyloxycarbonyl group; amide groups such as carboxamide group An amino group; a substituted amino group such as a monomethylamino group or a methylethylamino group; a formyl group; Among these, a halogen atom group, an alkyl group, a ketone group, an alkoxy group, and a formyl group are preferable in consideration of crystal controllability at the time of crystal conversion. In particular, when the three-dimensional molecular volume as a substituent is increased, the crystal controllability at the time of crystal transformation is reduced. Specifically, acetyl group, chloro group, methyl group, ethyl group, methoxy group, formyl Group is preferable, and an acetyl group, a chloro group, and a methyl group are more preferable.

  In addition, the fluorinated aromatic compound used in the present invention may have only one substituent having a substituent constant σm of 0.48 or less, or may have two or more.

  Examples of the aromatic skeleton of the fluorinated aromatic compound include aromatic hydrocarbon skeletons such as benzene, naphthalene, anthracene, phenanthrene, tetralin, biphenyl, and terphenyl, and heterocyclic rings such as pyrrole, thiophene, furan, pyridine, quinoline, and phenanthroline. An aromatic skeleton may be mentioned. Any of these can be used, but if the aromatic skeleton has a heteroatom such as nitrogen, oxygen, sulfur, etc., the controllability when the phthalocyanine crystal precursor is converted into a specific crystal type is reduced. An aromatic hydrocarbon skeleton is preferred.

  The number of fluorine atoms directly bonded to the aromatic ring of the fluorinated aromatic compound is arbitrary, but as the number of fluorine atoms increases, the controllability of the crystal type at the time of crystal conversion decreases, so that it is 3 or less. In view of the sensitivity of the electrophotographic photosensitive member, 2 or less is more preferable. Among these, it is particularly preferable that the number of fluorine atoms directly bonded to the aromatic ring is 1 (that is, a monofluoro-substituted aromatic compound).

  In addition, the fluorinated aromatic compound used in the present invention has a substituent having a substituent constant σm of 0.48 or less and a fluorine atom directly bonded to the aromatic ring. One or more substituents having a group constant σm greater than 0.48 may be included. However, even in this case, the arithmetic average of the substituent constant σm of the substituent other than the fluorine atom is preferably 0.48 or less. In particular, the substituent constant σm of substituents other than fluorine atoms is preferably 0.48 or less.

  Further, since the contact with the phthalocyanine crystal precursor is usually performed at 100 ° C. or lower, the melting point of the fluorinated aromatic compound used in the present invention is usually 100 ° C. or lower. Among them, when the melting point is too high, the handling property of the fluorinated aromatic compound at the time of crystal conversion is lowered, and therefore 80 ° C. or lower is preferable, and 60 ° C. or lower is more preferable.

  The molecular weight of the fluorinated aromatic compound used in the present invention is usually 97 or more, preferably 110 or more, more preferably 130 or more, and usually 300 or less, preferably 280 or less, more preferably 250 or less. If the molecular weight is too small, the crystal controllability may be lowered, and if the molecular weight is too large, the stability of the obtained crystal may be lowered.

  In the present invention, any one of the above-mentioned fluorinated aromatic compounds having a specific substituent may be used alone, or a plurality of types may be used in any combination and composition.

[I-2. Composition of phthalocyanine crystals]
A phthalocyanine crystal is a mixed crystal composed of a crystal composed of a single type of phthalocyanine, a mixed crystal composed of a plurality of types of phthalocyanines, and one or more types of phthalocyanines and one or more types of other compounds. Divided into crystals. The phthalocyanine crystal of the present invention may be any of these, but from the viewpoint of crystal stability, it is preferably a crystal composed of a single kind of phthalocyanine or a mixed crystal composed of a plurality of kinds of phthalocyanines.

  As phthalocyanines, phthalocyanines having a planar molecular structure such as metal-free phthalocyanine, copper phthalocyanine, zinc phthalocyanine, and lead phthalocyanine; Examples thereof include phthalocyanines having a shuttlecock type molecular structure; phthalocyanines having a top type molecular structure such as dichlorotin phthalocyanine, dichlorosilicon phthalocyanine, dihydroxytin phthalocyanine, and dihydroxysilicon phthalocyanine.

  When the phthalocyanine crystal of the present invention is a crystal composed of a single kind of phthalocyanine, the type of phthalocyanine as a component thereof is not particularly limited, and any of the phthalocyanines exemplified above may be used. However, phthalocyanines having a shuttlecock type molecular structure are desirable from the viewpoint that the specific crystal type is easily constructed. Of these, the central metal of the phthalocyanine molecule is preferably an oxide, chloride, or hydroxide because the properties when used in an electrophotographic photoreceptor are generally good. More preferably, the metal is an oxide. Specifically, oxytitanyl phthalocyanine and oxyvanadyl phthalocyanine are particularly preferable, and oxytitanyl phthalocyanine is particularly preferable.

  On the other hand, when the phthalocyanine crystal of the present invention is a mixed crystal, the type of phthalocyanine as a component thereof is not particularly limited, and any of the phthalocyanines exemplified above may be used. However, it is preferable to contain, as a main component, phthalocyanine having a shuttlecock type molecular structure from the viewpoint that the above-mentioned specific crystal type is easily constructed. Of these, the central metal of the phthalocyanine molecule is preferably an oxide, chloride, or hydroxide because the properties when used in an electrophotographic photoreceptor are generally good. More preferably, the metal is an oxide. Specifically, oxytitanyl phthalocyanine and oxyvanadyl phthalocyanine are particularly preferable, and oxytitanyl phthalocyanine is particularly preferable.

  The content of phthalocyanine as a main component is usually 60% by weight or more in terms of the ratio to the phthalocyanine crystal. When the amount contained is small, crystal controllability is lowered, so 70% by weight or more is preferable. From the viewpoint of crystal stability at the time of dispersion, 80% by weight or more is more preferable, and when used in an electrophotographic photoreceptor. From the viewpoint of the characteristics, 85% by weight or more is more preferable.

  As the phthalocyanine other than phthalocyanine as the main component, phthalocyanine having a shuttlecock type molecular structure or phthalocyanine having a planar molecular structure is preferable from the viewpoint that the above-mentioned specific crystal type is easily constructed. Among these, phthalocyanine having a shuttlecock type molecular structure is preferable in terms of characteristics when used in an electrophotographic photosensitive member, and oxyvanadyl phthalocyanine, chlorogallium phthalocyanine, hydroxygallium phthalocyanine, and chloroindium phthalocyanine have a planar molecular structure. In phthalocyanine, metal-free phthalocyanine, zinc phthalocyanine, and lead phthalocyanine are preferable. Specifically, oxyvanadyl phthalocyanine, chlorogallium phthalocyanine, chloroindium phthalocyanine, hydroxygallium phthalocyanine, and metal-free phthalocyanine are more preferable, and since there are more vacant spaces in the crystal lattice, metal-free phthalocyanine having a planar molecular structure. Is particularly preferred. As phthalocyanines other than the main component, only one type may be used, or two or more types may be used in any combination and ratio, but it is preferable to use only one type.

  The content of phthalocyanine other than the main component is usually 40% by weight or less in terms of the ratio to the phthalocyanine crystal. When the content of phthalocyanine other than the main component is too large, the crystal controllability is lowered, so 30% by weight or less is preferable. From the viewpoint of stability during dispersion, 20% by weight or less is more preferable. In terms of surface, 15% by weight or less is particularly preferable. However, if the content of phthalocyanine other than the main component is too small, the effect of the inclusion may not be obtained, so it is usually 0.1% by weight or more, preferably 0.5% by weight or more.

[I-3. Production of phthalocyanine crystals]
The phthalocyanine crystal of the present invention is produced through a step of bringing a precursor of a phthalocyanine crystal having the above composition into contact with the above-described fluorinated aromatic compound having a substituent.

  As the phthalocyanine crystal precursor, amorphous phthalocyanine or low crystalline phthalocyanine is used. As a preparation method of amorphous phthalocyanine or low crystalline phthalocyanine, a known preparation method such as a chemical treatment method such as an acid paste method or an acid slurry method; a mechanical treatment method such as grinding or grinding can be used. However, since a uniform amorphous phthalocyanine or low crystalline phthalocyanine can be obtained, a chemical treatment method is preferable, and an acid paste method is more preferable.

  The method for bringing the phthalocyanine crystal precursor into contact with the fluorinated aromatic compound is not particularly limited as long as it does not depart from the gist of the present invention, and any known method can be used. Examples include (i) a technique in which a fluorinated aromatic compound is vaporized and a phthalocyanine crystal precursor is introduced into contact therewith, and (ii) a fluorinated aromatic compound and a phthalocyanine crystal precursor are mixed with a solvent (type of solvent Is not particularly limited, but includes, for example, water or the like.) (Iii) A method in which a phthalocyanine crystal precursor and a fluorinated aromatic compound are contacted with stirring, an automatic mortar, a planetary mill, a vibrating ball mill In a device such as a CF mill, a roller mill, a sand mill, a kneader, etc., a method of contacting with a medium while applying a physical force may be mentioned. Among these, the method (ii) is preferable because the material can be easily handled. In particular, it is preferable to contact in the presence of water by the method (ii).

The conditions at the time of contact between the phthalocyanine crystal precursor and the fluorinated aromatic compound are not particularly limited as long as they do not depart from the gist of the present invention, and are specifically as follows.
The temperature at the time of contact is usually 0 ° C. or higher, preferably 10 ° C. or higher, and usually 100 ° C. or lower, particularly preferably 80 ° C. or lower.
The pressure at the time of contact is usually atmospheric pressure.
Although the contact time varies depending on conditions such as temperature, it is usually 1 minute or longer, especially 5 minutes or longer. The upper limit is not particularly limited, but considering efficiency, it is usually 10 hours or less, preferably 5 hours or less, more preferably 3 hours or less.

  The phthalocyanine crystal of the present invention is usually obtained as a wet cake. As will be described later, the effect of the present invention is considered to be obtained by bringing the phthalocyanine crystal precursor into the phthalocyanine crystal when the phthalocyanine crystal precursor is brought into contact with the fluorinated aromatic compound. Therefore, the content of the phthalocyanine crystals in the wet cake (the weight of the phthalocyanine crystals in the total weight of the wet cake) may be any amount.

  After the wet cake containing the phthalocyanine crystal of the present invention is obtained, a drying step is usually performed to remove the solvent component. The drying method can be dried by a known method such as air drying, heat drying, vacuum drying or freeze drying.

  The particle diameter of the phthalocyanine crystal of the present invention varies greatly depending on the conditions and prescriptions when contacting the fluorinated aromatic compound, but considering the dispersibility, the primary particle diameter is preferably 500 nm or less, and coating film formation From the viewpoint of properties, the thickness is preferably 250 nm or less.

[I-4. Properties of phthalocyanine crystals]
The phthalocyanine crystal of the present invention is a crystal type having a main diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.2 ° with respect to CuKα characteristic X-rays (wavelength 1.541Å).

  The effect of the fluorinated aromatic compound in the phthalocyanine crystal of the present invention is obtained by bringing the fluorinated aromatic compound to be used into the phthalocyanine crystal when the phthalocyanine crystal precursor is brought into contact with the fluorinated aromatic compound. It is believed that there is. Therefore, the effect of the present invention does not depend on the orientation of the molecules in the crystal, and it is considered that the intensity ratio of each of the clear diffraction peaks has no correlation with the effect of the present invention. Therefore, the phthalocyanine crystal of the present invention may have any strength ratio. Usually, the diffraction peak near 27.2 ° or the diffraction peak near 9.6 ° is often maximized.

  Examples of the clear diffraction peak of the phthalocyanine crystal of the present invention other than 27.2 ° include the following.

1) 9.6 °, 24.1 °
2) 9.5 °, 9.7 °, 24.1 °
3) 9.0 °, 14.2 °, 23.9 °

  Other diffraction peaks include peaks near 26.2 ° or 28.6 °, but phthalocyanine crystals having these diffraction peaks are dislocated to other crystal types at the time of dispersion, and electrophotographic characteristics are deteriorated. Therefore, it is preferable that there is no clear diffraction peak around 26.2 ° or 28.6 °.

  Also, phthalocyanine crystals having clear diffraction peaks at 9.5 °, 24.1 °, and 27.2 °, or clear at 9.5 °, 9.7 °, 24.1 °, and 27.2 ° A phthalocyanine crystal having a diffraction peak is preferable because of excellent crystal stability during dispersion.

  Among them, phthalocyanine crystals having main diffraction peaks at 7.3 °, 9.6 °, 11.6 °, 14.2 °, 18.0 °, 24.1 ° and 27.2 °, or 7.3 Phthalocyanine crystals having main diffraction peaks at °, 9.5 °, 9.7 °, 11.6 °, 14.2 °, 18.0 °, 24.2 ° and 27.2 ° From the standpoint of dark decay and residual potential when used as a material.

[I-5. Others]
In the present invention, the mechanism by which the value of the substituent constant σm of the substituent of the fluorinated aromatic compound affects the properties of the obtained phthalocyanine crystal is not clear, but is presumed as follows. That is, the above-mentioned specific crystal type (crystal type showing a main diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.2 ° with respect to CuKα characteristic X-ray (wavelength 1.541Å)) is compared with other crystal types. Since the crystal density is low and there are many vacant spaces in the crystal, the fluorinated aromatic compound is brought into contact with the phthalocyanine crystal precursor to construct the crystal type. It is thought that trace amounts of group compounds are taken up. Here, a fluorinated aromatic compound into which a substituent having a substituent constant σm of 0.48 or less in addition to a fluorine atom has an electronic state as a whole molecule, and this electronic state is in a phthalocyanine crystal. It is considered that both stability and sensitivity of the obtained phthalocyanine crystal are improved by contributing to the crystal stability and charge separation process.

[II. Electrophotographic photoreceptor]
Hereinafter, the electrophotographic photoreceptor of the present invention will be described in detail. The electrophotographic photosensitive member of the present invention has a photosensitive layer on a conductive support, and the photosensitive layer contains the phthalocyanine crystal of the present invention described above.

[II-1. Conductive support]
As the conductive support, for example, a metal material such as aluminum, aluminum alloy, stainless steel, copper, nickel, or a resin material imparted with conductivity by containing conductive powder such as metal, carbon, tin oxide, Mainly used are resin, glass, paper, or the like obtained by depositing or coating a conductive material such as aluminum, nickel, ITO (indium tin oxide) on the surface. As the shape, a drum shape, a sheet shape, a belt shape or the like is used. Alternatively, a conductive support made of a metal material may be used in which a conductive material having an appropriate resistance value is applied for the purpose of controlling conductivity, surface properties, etc., or for covering defects.

  The surface of the conductive support may be smooth, or may be roughened by using a special cutting method or polishing. Further, it may be roughened by mixing particles having an appropriate particle diameter with the material constituting the support. In order to reduce the cost, it is possible to use the drawing tube as it is without cutting. In particular, when using a non-cutting aluminum substrate such as drawing, impact processing, ironing, etc., it is preferable because the treatment eliminates dirt, foreign matter, and other foreign matters, small scratches, etc., and a uniform and clean substrate can be obtained. .

Moreover, when using metal materials, such as an aluminum alloy, as an electroconductive support body, you may use, after giving an anodic oxide film. Anodized film is formed, for example, by anodizing in an acidic bath such as chromic acid, sulfuric acid, oxalic acid, boric acid, sulfamic acid, etc. give. In the case of anodic oxidation in sulfuric acid, the sulfuric acid concentration is 100 to 300 g / l, the dissolved aluminum concentration is 2 to 15 g / l, the liquid temperature is 15 to 30 ° C., the electrolysis voltage is 10 to 20 V, and the current density is 0.5 to Although it is preferable to set within the range of ² A / dm ² , it is not limited to the above conditions.

  If the average thickness of the anodic oxide coating is too thick, strong sealing conditions are required due to high concentration of the sealing liquid and high temperature / long time treatment. Accordingly, productivity is deteriorated and surface defects such as spots, dirt, and dusting are easily generated on the coating surface. From such a point, it is preferable that the average film thickness of the anodic oxide coating is usually 20 μm or less, particularly 7 μm or less.

  When an anodized film is formed, it is preferable to perform a sealing treatment. The sealing treatment may be performed by a normal method, for example, a low-temperature sealing treatment in which the sealing material is immersed in an aqueous solution containing nickel fluoride as a main component, or a high-temperature sealing in which the sealing treatment is immersed in an aqueous solution containing nickel acetate as a main component. It is preferable to apply a hole treatment.

  In the case of low-temperature sealing treatment, the concentration of the nickel fluoride aqueous solution to be used can be selected as appropriate, but more preferable results are obtained when the concentration is in the range of 3 to 6 g / l. The pH of the aqueous nickel fluoride solution is usually 4.5 or higher, preferably 5.5 or higher, and usually 6.5 or lower, preferably 6.0 or lower. As the pH adjuster, oxalic acid, boric acid, formic acid, acetic acid, sodium hydroxide, sodium acetate, aqueous ammonia and the like can be used. In order to further improve the physical properties of the film, cobalt fluoride, cobalt acetate, nickel sulfate, a surfactant, and the like may be included in the nickel fluoride aqueous solution. The treatment temperature is usually in the range of 25 ° C. or higher, preferably 30 ° C. or higher, and usually 40 ° C. or lower, preferably 35 ° C. or lower, in order to facilitate the sealing treatment. The treatment time is preferably in the range of 1 to 3 minutes per 1 μm of film thickness. Subsequently, it is washed with water and dried to finish the low temperature sealing treatment.

  In the case of high-temperature sealing treatment, as the sealing agent, an aqueous metal salt solution such as nickel acetate, cobalt acetate, lead acetate, nickel acetate-cobalt, and barium nitrate can be used, and nickel acetate is particularly preferable. When using nickel acetate aqueous solution, it is preferable to use the density | concentration within the range of 5-20 g / l normally. It is preferable to treat the nickel acetate aqueous solution usually at a pH in the range of 5.0 to 6.0. As the pH regulator, aqueous ammonia, sodium acetate, or the like can be used. In order to improve the physical properties of the film, sodium acetate, an organic carboxylic acid, an anionic or nonionic surfactant may be contained in the nickel acetate aqueous solution. The treatment temperature is usually 80 ° C. or higher, preferably 90 ° C. or higher, and usually 100 ° C. or lower, preferably 98 ° C. or lower. The treatment time is usually 10 minutes or longer, preferably 20 minutes or longer. Subsequently, it is washed with water and dried to finish the high temperature sealing treatment.

[II-2. Undercoat layer]
An undercoat layer may be provided between the conductive support and the photosensitive layer described later for improving adhesion and blocking properties. As the undercoat layer, a binder resin, a binder resin in which particles such as metal oxide are dispersed, and the like are used.

  Examples of the metal oxide particles used for the undercoat layer include metal oxide particles containing one metal element such as titanium oxide, aluminum oxide, silicon oxide, zirconium oxide, zinc oxide, iron oxide, calcium titanate, Examples thereof include metal oxide particles containing a plurality of metal elements such as strontium titanate and barium titanate. Any one of these metal oxide particles may be used alone, or a plurality of these metal oxide particles may be mixed and used in an arbitrary combination and ratio. Among these metal particles, titanium oxide and aluminum oxide are preferable, and titanium oxide is particularly preferable. The surface of the titanium oxide particles may be treated with an inorganic substance such as tin oxide, aluminum oxide, antimony oxide, zirconium oxide, or silicon oxide, or an organic substance such as stearic acid, polyol, or silicone. As the crystal form of the titanium oxide particles, any of rutile, anatase, brookite, and amorphous can be used. Moreover, the thing of a several crystal state may contain.

  Various particle sizes can be used as the particle size of the metal oxide particles. Among these, from the viewpoint of characteristics and liquid stability, the average primary particle size is usually 10 nm or more, usually 100 nm or less, particularly 50 nm or less. Those are preferred.

  The undercoat layer is preferably formed in a form in which the metal oxide particles are dispersed in a binder resin. As binder resin used for the undercoat layer, epoxy resin, polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, polyamide resin, vinyl chloride resin, vinyl chloride resin, vinyl acetate resin, phenol resin, polycarbonate resin, polyurethane resin, Polyimide resin, vinylidene chloride resin, polyvinyl acetal resin, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol resin, polyurethane resin, polyacrylic acid resin, polyacrylamide resin, polyvinyl pyrrolidone resin, polyvinyl pyridine resin, water-soluble polyester resin, nitro Cellulose ester resins such as cellulose, cellulose ether resins, casein, gelatin, polyglutamic acid, starch, starch acetate, amino starch, zirconium chelate Compounds, organic zirconium compounds such as zirconium alkoxide compounds, titanyl chelate compounds, organic titanyl compounds such as titanyl alkoxide compound, may be a known binder resin such as a silane coupling agent. These can be used alone or in a cured form together with a curing agent. Among these, alcohol-soluble copolymerized polyamide, modified polyamide, and the like are preferable because they exhibit good dispersibility and coatability.

  The use ratio of the metal oxide particles with respect to the binder resin can be arbitrarily selected, but from the viewpoint of the stability of the dispersion and the coating property, it is usually used in the range of 10% by weight to 500% by weight. preferable.

  In addition, the undercoat layer may contain pigment particles, resin particles, and the like for the purpose of preventing image defects.

  The thickness of the undercoat layer can be arbitrarily selected, but is preferably 0.01 μm or more, more preferably 0.1 μm or more, usually 30 μm or less, especially 20 μm or less from the viewpoint of photoreceptor characteristics and applicability. .

[II-3. Photosensitive layer]
A photosensitive layer is formed on the conductive support (on the undercoat layer when an undercoat layer is provided). The photosensitive layer includes a charge generation material, a charge transport material, and a binder resin.

  As the structure of the photosensitive layer, a charge generation material and a charge transport material are dispersed in a binder resin and exist in the same layer (hereinafter referred to as “single layer type photosensitive layer” as appropriate), and charge generation. A photosensitive layer having a laminated structure in which a substance is dispersed into a charge generation layer in which a substance is dispersed in a binder resin and a charge transport layer in which a charge transport substance is dispersed in a binder resin (hereinafter, referred to as “laminated photosensitive layer” as appropriate). Any of these can be used. In the case of a laminated type photosensitive layer, a layered photosensitive layer is laminated in the order of a charge generation layer and a charge transport layer from the conductive support side, and a charge transport layer and a charge generation layer are laminated in this order from the side of the conductive support. Although it is divided into a reverse lamination type photosensitive layer, any of them can be applied. Hereinafter, each structure will be described.

<Charge generation layer of laminated photosensitive layer>
The charge generation layer of the multilayer photosensitive layer is prepared by dissolving or dispersing a binder resin in a solvent or dispersion medium and dispersing a charge generation material to prepare a coating solution. By coating and forming a film on the body (on the undercoat layer when an undercoat layer is provided) or on the charge transport layer in the case of a reverse laminated type photoreceptor, and binding fine particles of the charge generating material with a binder resin It is formed.

・ Charge generating materials:
As the charge generating substance, at least the phthalocyanine crystal of the present invention is used. Any one kind of the phthalocyanine crystals of the present invention may be used alone, but two or more kinds may be used in any combination and ratio. Further, only the phthalocyanine crystal of the present invention may be used as a charge generation material, but the phthalocyanine crystal of the present invention may be combined with other charge generation materials and used in a mixed state.

  It is desirable that the particle size of the phthalocyanine crystal of the present invention used as a charge generating substance is sufficiently small. Specifically, it is preferably 1 μm or less, more preferably 0.5 μm or less.

  Examples of other charge generation materials used in a mixed state with the phthalocyanine crystal of the present invention include various known dyes and pigments. Examples of dyes include phthalocyanine pigments, azo pigments, dithioketopyrrolopyrrole pigments, squalene (squarylium pigment), quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, anthanthrone pigments, benzimidazole pigments, and the like. . Of these, phthalocyanine pigments and azo pigments are preferably used from the viewpoint of photosensitivity.

・ Binder resin:
The type of the binder resin in the charge generation layer is not particularly limited. Examples thereof include polyvinyl butyral resin, polyvinyl formal resin, polyvinyl such as partially acetalized polyvinyl butyral resin in which a part of butyral is modified with formal or acetal. Acetal resin, polyarylate resin, polycarbonate resin, polyester resin, modified ether polyester resin, phenoxy resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin, polystyrene resin, acrylic resin, methacrylic resin, polyacrylamide resin , Polyamide resin, polyvinyl pyridine resin, cellulosic resin, polyurethane resin, epoxy resin, silicone resin, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, casein, salt Vinyl chloride-vinyl acetate copolymer such as vinyl-vinyl acetate copolymer, hydroxy-modified vinyl chloride-vinyl acetate copolymer, carboxyl-modified vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer Copolymer, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, styrene-alkyd resin, silicone-alkyd resin, phenol-formaldehyde resin and other insulating resins, poly-N-vinylcarbazole, polyvinylanthracene, It can be selected from organic photoconductive polymers such as polyvinyl perylene, but is not limited to these polymers. In addition, any one of these binder resins may be used alone, or two or more of these binder resins may be mixed and used in an arbitrary combination and ratio.

・ Combination ratio:
The compounding ratio (weight) of the binder resin and the charge generation material in the charge generation layer is usually 10 parts by weight or more, preferably 30 parts by weight or more, and usually 1000 parts by weight, based on the ratio of the charge generation material to 100 parts by weight of the binder resin. The range is not more than parts by weight, preferably not more than 500 parts by weight. If the ratio of the charge generation material is too high, the stability of the coating solution may be reduced due to problems such as aggregation of the charge generation material. Therefore, it is preferable to use within the above range.

・ Solvent or dispersion medium:
Examples of the solvent or dispersion medium used for preparing the coating liquid include saturated aliphatic solvents such as pentane, hexane, octane, and nonane; aromatic solvents such as toluene, xylene, and anisole; chlorobenzene, dichlorobenzene, and chloronaphthalene. Halogenated aromatic solvents such as amide solvents such as dimethylformamide and N-methyl-2-pyrrolidone; alcohol solvents such as methanol, ethanol, isopropanol, n-butanol and benzyl alcohol; fats such as glycerin and polyethylene glycol Aromatic polyhydric alcohols; chain and cyclic ketone solvents such as acetone, cyclohexanone and methyl ethyl ketone; ester solvents such as methyl formate, ethyl acetate and n-butyl acetate; halogens such as methylene chloride, chloroform and 1,2-dichloroethane Charcoal Hydrogen-based solvents; linear and cyclic ether solvents such as diethyl ether, dimethoxyethane, tetrahydrofuran, 1,4-dioxane, methyl cellosolve, ethyl cellosolve; non-aqueous solvents such as acetonitrile, dimethyl sulfoxide, sulfolane, hexamethylphosphate triamide, etc. Protic polar solvent; nitrogen-containing compounds such as n-butylamine, isopropanolamine, diethylamine, triethanolamine, ethylenediamine, triethylenediamine, triethylamine; mineral oil such as ligroin; water, etc., which do not dissolve the above-mentioned undercoat layer Is preferably used. Any one of these solvents or dispersion media may be used alone, or two or more thereof may be used in any combination and ratio.

・ Distribution method:
As a method for dispersing the charge generation material in a solvent or a dispersion medium, a known dispersion method such as a ball mill dispersion method, an attritor dispersion method, or a sand mill dispersion method can be used. At this time, it is effective to refine the charge generating material particles to a particle size of usually 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less.

・ Film thickness:
The film thickness of the charge generation layer is usually 0.1 μm or more, preferably 0.15 μm or more, and usually 10 μm or less, preferably 0.6 μm or less.

<Charge transport layer of laminated photosensitive layer>
The charge transport layer of the multilayer photosensitive layer is prepared by dissolving or dispersing the binder resin in a solvent and dispersing the charge transport material to prepare a coating solution. In the case of a multilayer type photoreceptor, it is formed by coating on a conductive support (or on the undercoat layer when an undercoat layer is provided) and binding fine particles of a charge transport material with a binder resin.

・ Binder resin:
Examples of the binder resin include polymers and copolymers of vinyl compounds such as butadiene resin, styrene resin, vinyl acetate resin, vinyl chloride resin, acrylic ester resin, methacrylic ester resin, vinyl alcohol resin, ethyl vinyl ether, and polyvinyl butyral. Resin, polyvinyl formal resin, partially modified polyvinyl acetal, polycarbonate resin, polyester resin, polyarylate resin, polyamide resin, polyurethane resin, cellulose ester resin, phenoxy resin, silicone resin, silicone-alkyd resin, poly-N-vinylcarbazole resin, etc. Is mentioned. These binder resins may be modified with a silicon reagent or the like. Of the binder resins, polycarbonate resins and polyarylate resins are particularly preferable.

  Among polycarbonate resins and polyarylate resins, polycarbonate resins and polyarylate resins containing a bisphenol residue and / or a biphenol residue represented by the following structural formula are preferable from the viewpoint of sensitivity and residual potential. To polycarbonate resin is more preferable.

These binder resins can also be used after being crosslinked with heat, light or the like using an appropriate curing agent.
In addition, any one kind of binder resin may be used alone, or two or more kinds may be mixed and used in an arbitrary combination and ratio.

・ Charge transport materials:
The charge transport material is not particularly limited as long as it is a known material. For example, aromatic nitro compounds such as 2,4,7-trinitrofluorenone, cyano compounds such as tetracyanoquinodimethane, diphenoquinone, etc. Electron withdrawing substances such as quinone compounds, carbazole derivatives, indole derivatives, imidazole derivatives, oxazole derivatives, pyrazole derivatives, thiadiazole derivatives, heterocyclic compounds such as benzofuran derivatives, aniline derivatives, hydrazone derivatives, aromatic amine derivatives, stilbene derivatives, Examples thereof include butadiene derivatives, enamine derivatives and those obtained by bonding a plurality of these compounds, or electron donating substances such as polymers having groups composed of these compounds in the main chain or side chain. Among these, carbazole derivatives, aromatic amine derivatives, stilbene derivatives, butadiene derivatives, enamine derivatives, and those in which a plurality of these compounds are bonded are preferable.

・ Combination ratio:
The ratio of the binder resin to the charge transport material is usually 20 parts by weight or more with respect to 100 parts by weight of the binder resin, preferably 30 parts by weight or more from the viewpoint of reducing the residual potential, and stability during repeated use and charge transfer. From the viewpoint of degree, 40 parts by weight or less is more preferable. On the other hand, it is usually 150 parts by weight or less from the viewpoint of thermal stability of the photosensitive layer, preferably 120 parts by weight or less from the viewpoint of compatibility between the charge transport material and the binder resin, and 100 from the viewpoint of printing durability. The amount is preferably not more than parts by weight, and particularly preferably not more than 80 parts by weight from the viewpoint of scratch resistance.

-Solvent or dispersion medium and dispersion method:
The type of the solvent or dispersion medium and the method for dispersing the charge transport material in the solvent or dispersion medium are as described in the section <Charge generation layer of laminated photosensitive layer>.

・ Film thickness:
The thickness of the charge transport layer is not particularly limited, but is usually 5 μm or more, particularly 10 μm or more, and usually 50 μm or less, especially 45 μm or less, more preferably 30 μm or less from the viewpoints of long life and image stability and high resolution. It is preferable to set it as the range.

<Single layer type photosensitive layer>
A single-layer type photosensitive layer is obtained by applying a coating solution obtained by dissolving or dispersing a charge generating substance, a charge transporting substance, and a binder resin on a conductive support (on the undercoat layer when an undercoat layer is provided). And the fine particles of the charge generation material and the charge transport material are bound by a binder resin. As the charge generation material, those described in the section <Charge generation layer of multilayer photosensitive layer> are used. As the charge transport material and the binder resin, those of <Charge transport layer of multilayer photosensitive layer> are used. Those described in the column are used. The ratios of the charge generation material and the charge transport material to the binder resin are also as described in the above sections <Charge generation layer of multilayer photosensitive layer> and <Charge transport layer of multilayer photosensitive layer>, respectively.

  If the phthalocyanine crystal dispersed in the single-layer type photosensitive layer is too small, sufficient sensitivity cannot be obtained, and if it is too large, there is an adverse effect on chargeability and sensitivity. The ratio of the charge generating material is preferably 0.1% by weight or more, more preferably 1% by weight or more, and preferably 50% by weight or less, more preferably 20% by weight or less.

The kind of the solvent or dispersion medium and the dispersion method are as described in the above section <Charge generation layer of laminated photosensitive layer>.
The film thickness of the single-layer type photosensitive layer is usually 5 μm or more, preferably 10 μm or more, and usually 100 μm or less, preferably 50 μm or less.

<Other ingredients>
The photosensitive layer has well-known antioxidants, plasticizers, ultraviolet absorbers, electron-withdrawing compounds to improve film-forming properties, flexibility, coating properties, stain resistance, gas resistance, light resistance, etc. In addition, additives such as a leveling agent and a visible light shielding agent may be contained.

[II-4. Other layers]
As the configuration of the electrophotographic photosensitive member, in addition to the above-described layers, other layers may be provided without departing from the spirit of the present invention.

For example, a protective layer may be provided on the photosensitive layer for the purpose of preventing the photosensitive layer from being worn out or preventing or reducing the deterioration of the photosensitive layer due to a discharge substance generated from a charger or the like. The protective layer is formed by containing a conductive material in an appropriate binder resin, or charge transport such as a triphenylamine skeleton as described in JP-A-9-190004, JP-A-10-252377, etc. A copolymer using a compound having a function can be used. Examples of the conductive material include aromatic amino compounds such as TPD (N, N′-diphenyl-N, N′-bis- (m-tolyl) benzidine), antimony oxide, indium oxide, tin oxide, titanium oxide, and tin oxide. -Metal oxides such as antimony oxide, aluminum oxide, and zinc oxide can be used, but are not limited thereto. As the binder resin used for the protective layer, known resins such as polyamide resin, polyurethane resin, polyester resin, epoxy resin, polyketone resin, polycarbonate resin, polyvinyl ketone resin, polystyrene resin, polyacrylamide resin, and siloxane resin can be used. Also, a copolymer of the above resin with a skeleton having a charge transporting ability such as a triphenylamine skeleton as described in JP-A-9-190004 and JP-A-10-252377 can be used. The protective layer is preferably configured to have an electric resistance of 10 ⁹ to 10 ¹⁴ Ω · cm. If the electrical resistance is too high, the residual potential tends to increase and an image with a lot of fog tends to be formed. On the other hand, if the electrical resistance is too low, the image tends to be blurred and the resolution is lowered. In addition, the protective layer must be configured so as not to substantially impede transmission of light irradiated for image exposure.

  The surface layer (photosensitive layer) of the electrophotographic photosensitive member is also used for the purpose of reducing the frictional resistance and wear on the surface of the electrophotographic photosensitive member and increasing the transfer efficiency of toner from the electrophotographic photosensitive member to a transfer belt or paper. , A protective layer or the like) may contain a fluorine-based resin, a silicone resin, a polyethylene resin, or the like. Moreover, you may contain the particle | grains which consist of these resin, the particle | grains of an inorganic compound, etc.

[II-5. Formation method of each layer]
Each layer constituting these photoconductors is formed by applying the coating solution obtained by the above-described method on a support using a known coating method, repeating the coating and drying steps for each layer, and sequentially coating the layers. The

  When forming a photosensitive layer of a single-layer type photoreceptor and a charge transport layer of a function-separated type photoreceptor, the solid content concentration of the coating solution is usually 5% by weight or more, especially 10% by weight or more, and usually 40% by weight or less. Of these, the range of 35% by weight or less is preferable. The viscosity of the coating solution is usually in the range of 10 cps or more, preferably 50 cps or more, and usually 500 cps or less, preferably 400 cps or less.

  When the charge generation layer of the function-separated type photoreceptor is formed, the solid content concentration of the coating solution is usually 0.1% by weight or more, especially 1% by weight or more, and usually 15% by weight or less, especially 10% or less. It is preferable that Further, the viscosity of the coating liquid is preferably 0.01 cps or more, more preferably 0.1 cps or more, and usually 20 cps or less, especially 10 cps or less.

  Examples of the coating method include a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a wire bar coating method, a blade coating method, a roller coating method, an air knife coating method, and a curtain coating method. Other known coating methods can also be used.

  The method for drying the coating solution is not particularly limited, but it is usually preferable to dry by heating at room temperature without touching or blowing with air. The heating temperature is particularly preferably 30 to 200 ° C. for 1 minute to 2 hours. Further, the heating temperature may be constant or may be changed while drying.

[III. Image forming apparatus]
Next, an embodiment of an image forming apparatus using the electrophotographic photosensitive member of the present invention (an image forming apparatus of the present invention) will be described with reference to FIG. However, the embodiment is not limited to the following description, and can be arbitrarily modified without departing from the gist of the present invention.

  As shown in FIG. 1, the image forming apparatus includes an electrophotographic photosensitive member 1, a charging device 2, an exposure device 3, and a developing device 4, and further, a transfer device 5, a cleaning device 6, and a fixing device as necessary. A device 7 is provided.

  The electrophotographic photoreceptor 1 is not particularly limited as long as it is the above-described electrophotographic photoreceptor of the present invention, but in FIG. 1, as an example, a drum in which the above-described photosensitive layer is formed on the surface of a cylindrical conductive support. The photoconductor is shown. A charging device 2, an exposure device 3, a developing device 4, a transfer device 5, and a cleaning device 6 are arranged along the outer peripheral surface of the electrophotographic photoreceptor 1.

  The charging device 2 charges the electrophotographic photosensitive member 1 and uniformly charges the surface of the electrophotographic photosensitive member 1 to a predetermined potential. Examples of the charging device include a corona charging device such as a corotron and a scorotron, a direct charging device (contact type charging device) that charges a direct charging member to which a voltage is applied by contacting the photosensitive member surface, and a contact type charging device such as a charging brush. Often used. Examples of direct charging means include contact chargers such as charging rollers and charging brushes. In FIG. 1, a roller-type charging device (charging roller) is shown as an example of the charging device 2. As the direct charging means, either charging with air discharge or injection charging without air discharge is possible. Moreover, as a voltage applied at the time of charging, it is possible to use only a direct current voltage or to superimpose an alternating current on a direct current.

  The type of the exposure apparatus 3 is not particularly limited as long as it can expose the electrophotographic photoreceptor 1 to form an electrostatic latent image on the photosensitive surface of the electrophotographic photoreceptor 1. Specific examples include halogen lamps, fluorescent lamps, lasers such as semiconductor lasers and He—Ne lasers, LEDs, and the like. Further, exposure may be performed by a photoreceptor internal exposure method. The light used for the exposure is arbitrary. For example, the exposure may be performed using monochromatic light with a wavelength of 780 nm, monochromatic light with a wavelength slightly shorter than 600 nm to 700 nm, or monochromatic light with a short wavelength of 380 nm to 500 nm. . However, in the case of light having a short wavelength of less than 600 nm, there are cases where sufficient optical writing cannot be performed due to absorption by the azobenzene derivative. Therefore, exposure with monochromatic light of 600 nm to 800 nm is preferable.

  The type of the developing device 4 is not particularly limited, and an arbitrary device such as a dry development method such as cascade development, one-component insulating toner development, one-component conductive toner development, or two-component magnetic brush development, or a wet development method is used. be able to. In FIG. 1, the developing device 4 includes a developing tank 41, an agitator 42, a supply roller 43, a developing roller 44, and a regulating member 45, and has a configuration in which toner T is stored inside the developing tank 41. . Further, a replenishing device (not shown) for replenishing the toner T may be attached to the developing device 4 as necessary. The replenishing device is configured to be able to replenish toner T from a container such as a bottle or a cartridge.

  The supply roller 43 is formed from a conductive sponge or the like. The developing roller 44 is made of a metal roll such as iron, stainless steel, aluminum, or nickel, or a resin roll obtained by coating such a metal roll with a silicone resin, a urethane resin, a fluorine resin, or the like. The surface of the developing roller 44 may be smoothed or roughened as necessary.

  The developing roller 44 is disposed between the electrophotographic photoreceptor 1 and the supply roller 43 and is in contact with the electrophotographic photoreceptor 1 and the supply roller 43, respectively. The supply roller 43 and the developing roller 44 are rotated by a rotation drive mechanism (not shown). The supply roller 43 carries the stored toner T and supplies it to the developing roller 44. The developing roller 44 carries the toner T supplied by the supply roller 43 and contacts the surface of the electrophotographic photosensitive member 1.

  The regulating member 45 is formed of a resin blade such as silicone resin or urethane resin, a metal blade such as stainless steel, aluminum, copper, brass, phosphor bronze, or a blade obtained by coating such metal blade with resin. The regulating member 45 contacts the developing roller 44 and is pressed against the developing roller 44 side with a predetermined force by a spring or the like (a general blade linear pressure is 5 to 500 g / cm). If necessary, the regulating member 45 may be provided with a function of imparting charging to the toner T by frictional charging with the toner T.

  The agitator 42 is rotated by a rotation driving mechanism, and agitates the toner T and conveys the toner T to the supply roller 43 side. A plurality of agitators 42 may be provided with different blade shapes and sizes.

  As the toner, in addition to the pulverized toner, chemical toners such as suspension granulation, suspension polymerization, and emulsion polymerization aggregation can be used. In particular, in the case of chemical toners, those having a small particle size of about 4 to 8 μm are used, and those having a shape close to a sphere, and those outside a sphere such as a potato or rugby ball can also be used. . The polymerized toner is excellent in charging uniformity and transferability, and is preferably used for high image quality.

  The type of the toner T is arbitrary, and chemical toners such as suspension granulation, suspension polymerization, and emulsion polymerization aggregation can be used in addition to powdered toner. In the case of chemical toners, those having a small particle size of about 4 to 8 μm are preferable, and the toner particles have various shapes from a nearly spherical shape to a potato shape outside the spherical shape. Can be used. In particular, the polymerized toner is excellent in charging uniformity and transferability, and is suitably used for high image quality.

  The type of the transfer device 5 is not particularly limited, and an apparatus using an arbitrary system such as an electrostatic transfer method such as corona transfer, roller transfer, or belt transfer, a pressure transfer method, or an adhesive transfer method can be used. . Here, it is assumed that the transfer device 5 includes a transfer charger, a transfer roller, a transfer belt, and the like disposed so as to face the electrophotographic photoreceptor 1. The transfer device 5 applies a predetermined voltage value (transfer voltage) having a polarity opposite to the charging potential of the toner T, and transfers the toner image formed on the electrophotographic photosensitive member 1 to a recording paper (paper, medium) P. Is.

  There is no restriction | limiting in particular about the cleaning apparatus 6, Arbitrary cleaning apparatuses, such as a brush cleaner, a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, can be used. The cleaning device 6 is for scraping off residual toner adhering to the photoreceptor 1 with a cleaning member and collecting the residual toner. In addition, when there is little or almost no residual toner, the cleaning device 6 may not be provided.

  The fixing device 7 includes an upper fixing member (fixing roller) 71 and a lower fixing member (fixing roller) 72, and a heating device 73 is provided inside the fixing member 71 or 72. FIG. 1 shows an example in which a heating device 73 is provided inside the upper fixing member 71. The upper and lower fixing members 71 and 72 include a fixing roll in which a metal base tube made of stainless steel, aluminum or the like is coated with silicon rubber, a fixing roll in which Teflon (registered trademark) resin is coated, a fixing sheet, or the like. A member can be used. Further, the fixing members 71 and 72 may be configured to supply a release agent such as silicone oil in order to improve the releasability, or may be configured to forcibly apply pressure to each other by a spring or the like.

  When the toner transferred onto the recording paper P passes between the upper fixing member 71 and the lower fixing member 72 heated to a predetermined temperature, the toner is heated to a molten state and cooled after passing through the recording paper. Toner is fixed on P.

  The type of the fixing device is not particularly limited, and a fixing device of an arbitrary system such as the one used here, heat roller fixing, flash fixing, oven fixing, pressure fixing, or the like can be provided.

  In the image forming apparatus configured as described above, an image is recorded according to the following method (the image forming method of the present invention).

  That is, first, the surface (photosensitive surface) of the photoreceptor 1 is charged to a predetermined potential (for example, −600 V) by the charging device 2. At this time, charging may be performed with a DC voltage, or charging may be performed by superimposing an AC voltage on the DC voltage.

  Subsequently, the photosensitive surface of the charged photoreceptor 1 is exposed by the exposure device 3 according to the image to be recorded, and an electrostatic latent image is formed on the photosensitive surface. The developing device 4 develops the electrostatic latent image formed on the photosensitive surface of the photoreceptor 1.

  The developing device 4 thins the toner T supplied by the supply roller 43 with a regulating member (developing blade) 45 and has a predetermined polarity (here, the same polarity as the charging potential of the photosensitive member 1) and the negative polarity. ), And conveyed while being carried on the developing roller 44 to be brought into contact with the surface of the photoreceptor 1.

  When the charged toner T carried on the developing roller 44 comes into contact with the surface of the photoreceptor 1, a toner image corresponding to the electrostatic latent image is formed on the photosensitive surface of the photoreceptor 1. This toner image is transferred onto the recording paper P by the transfer device 5. Thereafter, the toner remaining on the photosensitive surface of the photoreceptor 1 without being transferred is removed by the cleaning device 6.

  After the transfer of the toner image onto the recording paper P, the final image is obtained by passing the fixing device 7 and thermally fixing the toner image onto the recording paper P.

  In addition to the above-described configuration, the image forming apparatus may be configured to perform, for example, a static elimination process. The neutralization step is a step of neutralizing the electrophotographic photosensitive member by exposing the electrophotographic photosensitive member, and a fluorescent lamp, an LED, or the like is used as the neutralizing device. In addition, the light used in the static elimination process is often light having an exposure energy that is at least three times that of the exposure light.

  The image forming apparatus may be further modified. For example, the image forming apparatus may be configured to perform a pre-exposure process, an auxiliary charging process, or the like, or may be configured to perform offset printing. A full-color tandem system configuration using toner may be used.

  The electrophotographic photoreceptor 1 is used alone or in combination with one or more elements of the charging device 2, the exposure device 3, the developing device 4, the transfer device 5, the cleaning device 6, and the fixing device 7. And an integrated cartridge (this is appropriately referred to as an “electrophotographic photosensitive member cartridge”), and the electrophotographic photosensitive member cartridge is configured to be detachable from a main body of an image forming apparatus such as a copying machine or a laser beam printer. Also good. In this case, a cartridge case configured to be detachable from the image forming apparatus is used, and the electrophotographic photosensitive member 1 is accommodated and supported by the cartridge case alone or in combination with the above-described elements. It can be. With this configuration, for example, when the electrophotographic photosensitive member 1 and other members deteriorate, the electrophotographic photosensitive member cartridge is removed from the main body of the image forming apparatus, and another new electrophotographic photosensitive member cartridge is mounted on the main body of the image forming apparatus. This facilitates maintenance and management of the image forming apparatus.

  Hereinafter, the present invention will be described in more detail with reference to production examples, examples and comparative examples. In addition, the following examples are shown in order to explain the present invention in detail, and the present invention is not limited to the following examples unless it is contrary to the gist thereof.

[I. Phthalocyanine material]
[Synthesis Example 1]
A β-type oxytitanyl phthalocyanine was prepared in the order of “Example of production of crude TiOPc” and “Example 1” described in JP-A-10-7925 (hereinafter referred to as “phthalocyanine material of Synthesis Example 1”). is there.). The powder XRD spectrum of the phthalocyanine material of Synthesis Example 1 is shown in FIG. Moreover, as a result of analyzing the chlorine content contained in the phthalocyanine material of Synthesis Example 1 using an elemental analysis technique, the chlorine content was 0.20% by weight or less below the lower limit of detection. In addition, when the peak intensity ratio of oxytitanyl phthalocyanine and chlorooxy titanyl phthalocyanine in the phthalocyanine material of Synthesis Example 1 was measured according to <Mass Spectrum Measurement Method> described in JP-A No. 2001-115054, it was 0.002. It was.

[Synthesis Example 2]
Β-type oxytitanyl phthalocyanine was prepared according to the technique of “Example 4” described in JP-A No. 2001-115054 (hereinafter sometimes referred to as “phthalocyanine material of Synthesis Example 2”). The powder XRD spectrum of the phthalocyanine material of Synthesis Example 2 is shown in FIG. Moreover, as a result of analyzing the chlorine content contained in the phthalocyanine material of Synthesis Example 2 using an elemental analysis method, the chlorine content was 0.37%. Moreover, when the peak intensity ratio of oxytitanyl phthalocyanine and chlorooxy titanyl phthalocyanine in the phthalocyanine material of Synthesis Example 2 was measured according to <Mass Spectrum Measurement Method> described in JP-A No. 2001-115054, 0.032-0 0.035.

Synthesis Example 3 (Low Crystalline Oxytitanyl Phthalocyanine)
50 parts by weight of the phthalocyanine material (β-type oxytitanyl phthalocyanine) of Synthesis Example 1 was added to 1250 parts by weight of 95% by weight concentrated sulfuric acid cooled to −10 ° C. or lower. At this time, it added slowly so that the internal temperature of a solution might not exceed -5 degreeC. After completion of the addition, the resulting solution was stirred at −5 ° C. or lower for 2 hours. After stirring, the solution was filtered through a glass filter, the insoluble matter was filtered off, and then the solution was released into 12500 parts by weight of ice water to precipitate oxytitanyl phthalocyanine, followed by stirring for 1 hour. After stirring, the solution was filtered off, and the resulting wet cake was washed again in 2500 parts by weight of water for 1 hour and filtered. By repeating this washing operation until the ionic conductivity of the filtrate reaches 0.5 mS / m, a wet cake of low crystalline oxytitanyl phthalocyanine (hereinafter sometimes referred to as “phthalocyanine material of Synthesis Example 3”). (Oxytitanyl phthalocyanine content 11.0% by weight) 452 parts by weight were obtained. The powder XRD spectrum of the phthalocyanine material of Synthesis Example 3 is shown in FIG.

[Synthesis Example 4]
33 parts by weight of a wet cake of the phthalocyanine material (low crystalline oxytitanyl phthalocyanine) of Synthesis Example 3 was added to 90 parts by weight of water and stirred at room temperature for 30 minutes. Thereafter, 13 parts by weight of 2,4-dichlorofluorobenzene was added, and the mixture was further stirred at room temperature for 1 hour. After stirring, water was separated, 80 parts by weight of methanol was added, and the mixture was stirred and washed at room temperature for 1 hour. After washing, it was filtered and again stirred and washed with 80 parts by weight of methanol for 1 hour, filtered and dried by heating in a vacuum dryer to obtain 3.4 parts by weight of oxytitanyl phthalocyanine (hereinafter referred to as “ It may be referred to as “phthalocyanine material of Synthesis Example 4”). The powder XRD spectrum of the phthalocyanine material of Synthesis Example 4 is shown in FIG.

[Synthesis Examples 5-7, Comparative Synthesis Examples 1-4]
The same operation as in Synthesis Example 4 except that 2,4-dichlorofluorobenzene used in Synthesis Example 4 was changed to the compounds shown in the columns of Synthesis Examples 5 to 7 and Comparative Synthesis Examples 1 to 4 in Table 2 below. To obtain oxytitanyl phthalocyanine (these may be hereinafter referred to as “phthalocyanine materials of Synthesis Examples 5 to 7 and Comparative Synthesis Examples 1 to 4”). The powder XRD spectra of the phthalocyanine materials of Synthesis Examples 5 to 7 and Comparative Synthesis Examples 1 to 4 are shown in FIGS.

[Synthesis Example 8]
The same operation as in Synthesis Example 3 is performed except that 50 parts by weight of the phthalocyanine material of Synthesis Example 1 used as a raw material in Synthesis Example 3 is changed to 50 parts by weight of the phthalocyanine material (β-type oxytitanyl phthalocyanine) of Synthesis Example 2. As a result, 478 parts by weight of a wet cake (oxytitanyl phthalocyanine content 10.4% by weight) of a low crystalline oxytitanyl phthalocyanine (hereinafter sometimes referred to as “phthalocyanine material of Synthesis Example 8”) was obtained. FIG. 13 shows a powder XRD spectrum of the phthalocyanine material of Synthesis Example 8.

[Synthesis Example 9]
33 parts by weight of a wet cake of the phthalocyanine material (low crystalline oxytitanyl phthalocyanine) of Synthesis Example 8 was added to 90 parts by weight of water and stirred at room temperature for 30 minutes. Thereafter, 13 parts by weight of 2,4-dichlorofluorobenzene was added, and the mixture was further stirred at room temperature for 1 hour. After stirring, water was separated, and 80 parts by weight of methanol was stirred and washed for 1 hour at room temperature. After washing, it was filtered and again stirred and washed with 80 parts by weight of methanol for 1 hour, filtered and dried by heating in a vacuum dryer to obtain 3.4 parts by weight of oxytitanyl phthalocyanine (hereinafter referred to as “ It may be referred to as “phthalocyanine material of Synthesis Example 9”). A powder XRD spectrum of the phthalocyanine material of Synthesis Example 9 is shown in FIG.

[Comparative Synthesis Example 5]
Except for changing 2,4-dichlorofluorobenzene used in Synthesis Example 9 to orthodichlorobenzene, the same operation as in Synthesis Example 9 was performed to obtain 3.5 parts by weight of oxytitanyl phthalocyanine (hereinafter referred to as “this”). It may be referred to as “phthalocyanine material of Comparative Synthesis Example 5”). The powder XRD spectrum of the phthalocyanine material of Comparative Synthesis Example 5 is shown in FIG.

[Synthesis Example 10]
50 parts by weight of the phthalocyanine material of Synthesis Example 1 used as a raw material in Synthesis Example 3 was replaced with 47.5 parts by weight of the phthalocyanine material (β-type oxytitanyl phthalocyanine) of Synthesis Example 1 and metal-free phthalocyanine (Dainippon Ink Chemical Co., Ltd.) A low crystalline phthalocyanine composition (hereinafter referred to as “phthalocyanine material of Synthesis Example 10”) by performing the same operation as in Synthesis Example 3 except that the mixture was changed to 2.5 parts by weight of “Fastgen Blue 8120BS” manufactured by the company. 410 parts by weight of wet cake (oxytitanyl phthalocyanine mixed crystal content 12.2% by weight) was obtained. A powder XRD spectrum of the phthalocyanine material of Synthesis Example 10 is shown in FIG.

[Synthesis Example 11]
33 parts by weight of a wet cake of the phthalocyanine material (low crystalline phthalocyanine composition) of Synthesis Example 10 was added to 90 parts by weight of water and stirred at room temperature for 30 minutes. Thereafter, 13 parts by weight of 2,4-dichlorofluorobenzene was added, and the mixture was further stirred at room temperature for 1 hour. After stirring, water was separated, 80 parts by weight of methanol was added, and the mixture was stirred and washed at room temperature for 1 hour. After washing, the mixture is separated by filtration, washed again with stirring using 80 parts by weight of methanol for 1 hour, separated by filtration, and dried by heating in a vacuum drier. ), 3.4 parts by weight were obtained. The powder XRD spectrum of the phthalocyanine material of Synthesis Example 11 is shown in FIG.

[Synthesis Example 12, Comparative Synthesis Example 6]
By performing the same operation as in Synthesis Example 11, except that 2,4-dichlorofluorobenzene used in Synthesis Example 4 was changed to the compounds shown in the columns of Synthesis Example 12 and Comparative Synthesis Example 6 in Table 2 below, respectively. Thus, mixed crystals containing oxytitanyl phthalocyanine were obtained (hereinafter, these may be referred to as “Synthesis Example 12 and Comparative Synthesis Example 6 phthalocyanine material”, respectively). The powder XRD spectra of the phthalocyanine materials of Synthesis Example 12 and Comparative Synthesis Example 6 are shown in FIGS. 18 and 19, respectively.

[Evaluation of phthalocyanine materials]
The phthalocyanine materials of Synthesis Examples 4 to 7, 9, 11, and 12 are compounds satisfying the definition of the present invention (having a fluorine atom directly bonded to an aromatic ring, and a substituent constant σm according to the Hammett rule is 0.48 or less. And an aromatic compound having a substituent. Further, as is apparent from FIGS. 5 to 10, 14, 15, and 17 to 19, the phthalocyanine materials of Synthesis Examples 4 to 7, 9, 11, and 12 and Comparative Synthesis Examples 1, 2, 5, and 6 have CuKα characteristics X. It was an oxytitanyl phthalocyanine crystal showing a main diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.2 ° with respect to the line (wavelength 1.541Å).

  In contrast, the phthalocyanine materials of Comparative Synthesis Examples 3 and 4 are compounds that do not satisfy the provisions of the present invention (there are no fluorine atoms directly bonded to the aromatic ring, or the substituent constant σm according to the Hammett rule is And an aromatic compound having no substituent that is 0.48 or less). 11 and 12, the phthalocyanine materials of Comparative Synthesis Examples 3 and 4 mainly have a Bragg angle (2θ ± 0.2 °) of 27.2 ° with respect to the CuKα characteristic X-ray (wavelength 1.541Å). It was not an oxytitanyl phthalocyanine crystal showing a diffraction peak.

  From this result, it is clear that a fluorinated aromatic compound not satisfying the provisions of the present invention has low crystal controllability at the time of crystal conversion, and the Bragg angle (2θ ±) with respect to CuKα characteristic X-ray (wavelength 1.541Å) 0.2 °) In order to obtain an oxytitanyl phthalocyanine crystal having a main diffraction peak at 27.2 °, it can be seen that it is effective to use a fluorinated aromatic compound satisfying the definition of the present invention.

[II. Electrophotographic photoreceptor]
[Method for producing electrophotographic photosensitive member]
Using a conductive support in which an aluminum vapor deposition film (thickness 70 nm) is formed on the surface of a biaxially stretched polyethylene terephthalate resin film (thickness 75 μm), the undercoat layer described below is formed on the vapor deposition film of the conductive support. The dispersion was applied by a bar coater so that the film thickness after drying was 1.25 μm or less, and dried to form an undercoat layer.

  High-speed fluidized mixing of rutile type titanium oxide having an average primary particle diameter of 40 nm (“TTO55N” manufactured by Ishihara Sangyo Co., Ltd.) and 3% by weight of methyldimethoxysilane (“TSL8117” manufactured by Toshiba Silicone Co., Ltd.) Disperse the surface-treated titanium oxide obtained by mixing in a kneading machine (“SMG300” manufactured by Kawata Co., Ltd.) and mixing at high speed at a rotational peripheral speed of 34.5 m / sec using a ball mill of methanol / 1-propanol. Thus, a dispersion slurry of hydrophobized titanium oxide was obtained. The dispersion slurry, a mixed solvent of methanol / 1-propanol / toluene, and ε-caprolactam [compound represented by the following formula (A)] / bis (4-amino-3-methylcyclohexyl) methane [the following formula ( Compound represented by B)] / hexamethylenediamine [compound represented by the following formula (C)] / decamethylene dicarboxylic acid [compound represented by the following formula (D)] / octadecamethylene dicarboxylic acid [following formula The compound represented by (E)] has a composition molar ratio of 75% / 9.5% / 3% / 9.5% / 3%, and is stirred and mixed while heating with the copolyamide pellets. After dissolving the polyamide pellets, by carrying out ultrasonic dispersion treatment, the weight ratio of methanol / 1-propanol / toluene is 7/1/2, and hydrophobically treated titanium oxide / copolymerized poly Containing bromide at a weight ratio of 3/1, it was undercoat layer dispersion having a solid concentration of 18.0%.

  As a charge generation material, 20 parts by weight of each phthalocyanine material described later was mixed with 280 parts by weight of 1,2-dimethoxyethane, and pulverized with a sand grind mill for 2 hours for atomization dispersion treatment. Subsequently, 10 parts by weight of polyvinyl butyral (trade name “Denkabutyral” # 6000C, manufactured by Denki Kagaku Kogyo Co., Ltd.) was added to 253 parts by weight of 1,2-dimethoxyethane and 4-methoxy-4. -A binder solution obtained by dissolving in 85 parts by weight of methyl-2-pentanone and 230 parts by weight of 1,2-dimethoxyethane were mixed to prepare a charge generation layer coating solution. This charge generation layer coating solution is applied onto the undercoat layer on the conductive support by a bar coater so that the film thickness after drying is 0.4 μm and dried to form a charge generation layer. did.

  Further, 50 parts by weight of a compound represented by the following formula (F) synthesized based on Example 1 of JP-A-2002-80432 is used as a charge transport material, and 2 represented by the following formula (G): , 2-bis (4-hydroxy-3-methylphenyl) propane as an aromatic diol component, 51 mol%, and 1,1-bis (4-hydroxyphenyl) -1 represented by the following formula (H) -It is composed of 49 mol% of repeating units containing phenylethane as an aromatic diol component, and 100 parts by weight of a polycarbonate resin having a terminal structural formula derived from pt-butylphenol is used as a binder resin. 8 parts by weight of di-t-butyl-4-methylphenol and 0.03 parts by weight of silicone oil (trade name KF96 Shin-Etsu Chemical Co., Ltd.) Rahidorofuran / toluene was dissolved in (weight ratio 8/2) mixed solvent 640 parts by weight to prepare a charge transport layer coating solution. This charge transport layer coating solution is applied on the charge generation layer with a film applicator so that the film thickness after drying is 25 μm, and is dried to form a charge transport layer. The body was made.

[Examples 1-7, Comparative Examples 1-4]
Using the phthalocyanine materials of Synthesis Examples 4 to 7, 9, 11, 12, and Comparative Synthesis Examples 1, 2, 5, and 6, the electrophotographic photosensitive member was prepared in accordance with the procedure described in [Method for producing electrophotographic photosensitive member] above. (These may be hereinafter referred to as “electrophotographic photoreceptors of Examples 1 to 7 and Comparative Examples 1 to 4”.) Table 3 below shows the correspondence between the electrophotographic photosensitive member of each Example and each Comparative Example and the phthalocyanine material used for the production thereof.

[Measurement of characteristics of electrophotographic photosensitive member]
The electrophotographic photosensitive members of Examples 1 to 7 and Comparative Examples 1 to 4 were produced according to the electrophotographic society standard (hereinafter, electrophotographic technology basics and applications, edited by the Electrophotographic Society, Corona, 404). ˜ 405), and the electrical characteristics were evaluated according to the cycle of charging, exposure, potential measurement, and static elimination according to the following procedure.

Irradiation energy (half-exposure exposure) when the surface potential becomes -350 V by charging the photosensitive member so that the initial surface potential is -700 V and irradiating the light of the halogen lamp with a monochromatic light of 780 nm with an interference filter. Energy) was measured as sensitivity (E _1/2 ) (unit: μJ / cm ² ). Further, after setting the initial surface potential to −700 V, the surface potential after being left in a dark place for 5 seconds was measured, and the difference was defined as dark decay (DD) (unit: V).

  The evaluation results of the electrophotographic characteristics of the electrophotographic photoreceptors of Examples 1 to 7 and Comparative Examples 1 to 4 are shown in Table 4 below.

From the above measurement results, the electrophotographic photoreceptors of Examples 1 to 7 containing the phthalocyanine crystal of the present invention (phthalocyanine materials of Synthesis Examples 4 to 7, 9, 11, and 12) in the photosensitive layer are known compounds. Compared with the electrophotographic photoreceptors of Comparative Examples 1 to 4 containing the phthalocyanine material (phthalocyanine materials of Comparative Synthesis Examples 1, 2, 5, and 6) obtained in contact with the photosensitive layer, dark decay (DD) It has been clarified that it is possible to increase only the sensitivity (E _1/2 ) without impairing the basic characteristics of the photoconductor.

  The phthalocyanine crystal of the present invention and an electrophotographic photosensitive member, an electrophotographic photosensitive member cartridge, and an image forming apparatus using the same are used in various fields such as various electrophotographic devices such as copying machines, printers, and fax machines using electrophotographic technology. It can be preferably used.

1 is a schematic diagram illustrating a main configuration of an embodiment of an image forming apparatus of the present invention. 3 is a powder XRD spectrum of the phthalocyanine material obtained in Synthesis Example 1. FIG. 3 is a powder XRD spectrum of the phthalocyanine material obtained in Synthesis Example 2. 4 is a powder XRD spectrum of the phthalocyanine material obtained in Synthesis Example 3. 7 is a powder XRD spectrum of the phthalocyanine material obtained in Synthesis Example 4. 7 is a powder XRD spectrum of the phthalocyanine material obtained in Synthesis Example 5. 7 is a powder XRD spectrum of the phthalocyanine material obtained in Synthesis Example 6. 7 is a powder XRD spectrum of the phthalocyanine material obtained in Synthesis Example 7. 2 is a powder XRD spectrum of a phthalocyanine material obtained in Comparative Synthesis Example 1. FIG. 3 is a powder XRD spectrum of a phthalocyanine material obtained in Comparative Synthesis Example 2. 4 is a powder XRD spectrum of a phthalocyanine material obtained in Comparative Synthesis Example 3. 7 is a powder XRD spectrum of a phthalocyanine material obtained in Comparative Synthesis Example 4. 10 is a powder XRD spectrum of the phthalocyanine material obtained in Synthesis Example 8. 10 is a powder XRD spectrum of the phthalocyanine material obtained in Synthesis Example 9. 6 is a powder XRD spectrum of a phthalocyanine material obtained in Comparative Synthesis Example 5. FIG. 4 is a powder XRD spectrum of the phthalocyanine material obtained in Synthesis Example 10. 7 is a powder XRD spectrum of the phthalocyanine material obtained in Synthesis Example 11. 7 is a powder XRD spectrum of the phthalocyanine material obtained in Synthesis Example 12. 7 is a powder XRD spectrum of the phthalocyanine material obtained in Comparative Synthesis Example 6.

Explanation of symbols

1 Photoconductor (Electrophotographic photoconductor)
2 Charging device (charging roller; charging unit)
3 Exposure equipment (exposure section)
4 Development device (development unit)
5 Transfer device 6 Cleaning device (cleaning part)
7 Fixing Device 41 Developing Tank 42 Agitator 43 Supply Roller 44 Developing Roller 45 Regulating Member 71 Upper Fixing Member (Fixing Roller)
72 Lower fixing member (fixing roller)
73 Heating device T Toner P Recording paper (paper, medium)

Claims (4)

A phthalocyanine crystal showing a main diffraction peak at a Bragg angle (2θ ± 0.2 °) of 27.2 ° with respect to CuKα characteristic X-ray (wavelength 1.541１．５),
Having a fluorine atom directly bonded to the aromatic ring, and, on the aromatic compound having a substituent group substituent constant σm by Hammett rule is 0.48 or less, resulting et Re through the step of contacting a phthalocyanine crystal precursor ,
The substituent of the aromatic compound is a halogen atom other than a fluorine atom;
A phthalocyanine crystal, wherein the phthalocyanine crystal contains oxytitanyl phthalocyanine. In an electrophotographic photoreceptor having a photosensitive layer on a conductive support,
The photosensitive layer, characterized in that it contains a phthalocyanine crystal according to claim 1 Symbol mounting an electrophotographic photosensitive member. The electrophotographic photosensitive member according to claim 2 ,
An electrophotographic photosensitive member cartridge comprising: a cartridge case that detachably supports the electrophotographic photosensitive member with respect to an image forming apparatus. The electrophotographic photosensitive member according to claim 2 ,
A charging unit for charging the electrophotographic photosensitive member;
Exposing the charged electrophotographic photoreceptor to form an electrostatic latent image; and
An image forming apparatus comprising: a developing unit that develops an electrostatic latent image formed on the electrophotographic photosensitive member.

Images