TWI454862B - Electrophotographic apparatus - Google Patents

Description

Electrophotographic photoreceptor

The present invention relates to a photoreceptor for electrophotography (hereinafter also simply referred to as "photoreceptor"), and more particularly to image formation of an electrophotographic printer, photocopier, facsimile machine, etc. A photoreceptor for electrophotography used in the device.

The photosensitive system for electrophotography has a structure in which a photosensitive layer is provided on a conductive substrate as a basic structure. In recent years, an electrophotographic photoreceptor using an organic photoconductive material has been able to design various photoreceptor characteristics due to the increase in the degree of freedom of pollution, low cost, and material selection. Many have been proposed and have been put to practical use.

The photosensitive layer of the organic photoreceptor is mainly composed of a layer in which an organic photoconductive substance is dispersed in a resin, and a charge generating substance is dispersed in a layer of a resin (a charge generating layer) and a layer in which a charge transporting substance is dispersed in a resin (charge transporting) The layered structure or the single layer structure in which the charge generating substance and the charge transporting substance are dispersed in the resin have been proposed.

In general, electrophotographic photosensitive systems are required to have the desired sensitivity, electrical characteristics, and optical characteristics in the electrophotographic process employed. Further, when the photoreceptor used is repeated, the outermost layer of the photoreceptor, that is, the layer most isolated from the conductive substrate, may be directly applied with corona charging or toner phenomenon, transfer to paper, cleaning treatment, etc. The electrical and mechanical external forces are required to be durable. Specifically, it is required to have durability against surface wear or damage caused by friction with other members, surface deterioration due to ozone generated when corona is charged, and the like. In particular, since the life of the photoreceptor for electrophotography is large due to surface wear, a person who can suppress film damage on the surface is sought. Further, there is also a problem of a toner or a problem of toner adhesion (film formation) on the surface of the photoreceptor caused by repeated cleaning. If film formation occurs, some of them become image defects, so this is also a problem that should be prevented. In order to prevent filming, it is necessary to improve the cleanliness of the surface of the photoreceptor.

However, a test for adding a lubricating component to the surface of the photoreceptor to improve the lubricity of the surface and to reduce the adhesion of the toner to the surface to prevent the adhesion of the toner and suppress the film formation has been carried out. However, when liquid lubricity is used, the effect of the effect of the repeated use is poor, and in the case of the solid lubricity, there is a problem in the dispersibility or stability of the coating liquid.

In the technique of improving the surface properties of the photoreceptor, for example, Patent Document 1 discloses that the anti-wear property is excellent in achieving reciprocal use, and the energy of the surface of the photoreceptor can be reduced, and filming, bottom contamination, and the like can be prevented. Since the photoreceptor is provided, a photoreceptor for electrophotography having a specific amount of specific eucalyptus oil is added to the photosensitive layer. However, in this technique, the eucalyptus oil is dispersed in the photosensitive layer to obtain the lubricity of the surface. However, since the eucalyptus oil segregates on the surface of the photoreceptor, it is difficult to maintain the lubricity in the case of repeated use, and the durability is insufficient. By.

Further, a technique of applying microcapsules to a photoreceptor for electrophotography is known. The microcapsules are microcapsules of a micron size, and the technique of using the photoreceptor of such microcapsules, for example, is described in Patent Document 2 as a non-destructive feeling and can improve durability, ozone resistance, and moisture resistance. Therefore, the phthalocyanine-based photoconductive material powder and the sensitizer are microencapsulated with a resin, and then added to the electrophotographic material of the photoconductive layer.

Further, in Patent Document 3, when a color image is formed by using a photosensitive microcapsule containing a color toner, a light scatterer of a different amount is attached to each photosensitive microcapsule to control the sensitivity to the image. The original can obtain an image with true color reproducibility. Further, Patent Document 4 describes that the anti-friction consumable is treated with a specific resin on the outermost layer of the photoreceptor, and it is preferable to include a microcapsule-forming state to improve the abrasion resistance of the surface of the photoreceptor while reducing the wear resistance. Residual potential.

Further, Patent Document 5 discloses that in a developer support carrying a one-component developer (toner), a release resin containing a binder resin and a release agent as a core material is formed on the surface thereof. The film composed of the capsule particles improves the abrasion resistance of the film on the surface of the developer carrier, the surface roughness and the charge imparting property to the toner are stable, and the toner is excessively charged or the developer is supported and sensitized. The fusion on the body drum is difficult to occur, and a developer carrier which is less likely to cause a decrease in the image density can be realized.

(Patent Document 1) Japanese Laid-Open Patent Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. (Patent Document 4) Japanese Laid-Open Patent Publication No. 2001-290295 (Patent Document No. 5) (Patent Document 5)

(disclosure of the invention)

As described above, the improvement of the surface properties of the photoreceptor has been studied variously, but it is still insufficient, and a photoreceptor which can achieve a problem of better anti-friction property and which does not cause film formation is sought.

Therefore, the object of the present invention is to provide a surface which is excellent in lubricity and which is difficult to be cut and which is not easily scratched by solving the above-mentioned problems of the prior art, and further prevents image defects caused by film formation and the like. The photoreceptor for electrophotography which is excellent in durability and high in durability.

In order to achieve the above object, the inventors have found that the microcapsules containing the lubricating oil are dispersed and used in the outermost layer of the photoreceptor as a result of intensive research, and the above problems can be solved, and the present invention has been completed.

That is, the photoreceptor for electrophotography of the present invention has at least a photosensitive layer on a conductive substrate, and is characterized in that it contains a microcapsule containing a lubricating oil in the outermost layer.

Therefore, the outermost layer in the present invention means a layer which is the farthest from the conductive substrate and constitutes the outer surface of the photoreceptor. Further, the photosensitive layer includes both a laminated type in which a charge generating layer and a charge transporting layer are laminated, or a single layer type in which a charge generating layer and a charge transporting layer are contained. Further, the microcapsules containing the lubricating oil are also included in any one of the microcapsules of the lubricating oil and the adsorbed or impregnated into the microcapsules.

As described above, in the present invention, a microcapsule containing a lubricating oil in the outermost layer of the photoreceptor is used. In this way, the general liquid lubricating oil is added to the layer, and the lubricating oil is segregated on the surface. Therefore, the initial lubricity is good. However, if the surface is damaged, the lubricative oil will disappear. While maintaining the lubricity of the lubricating oil of the present invention, the lubricating oil can be dispersed in the interior of the outermost surface of the photoreceptor, so that it can be stably maintained even when used repeatedly. Lubricity. In addition, the wear resistance is improved and the surface is reduced, which also contributes to the life of the photoreceptor. Further, since the surface energy is small, it is also possible to prevent the toner from adhering to the surface of the photoreceptor. Further, it is also possible to prevent the occurrence of film formation, which is extremely effective for improving the surface properties of the photoreceptor.

Further, as described above, the microcapsule technology is suitable for a photoreceptor for electrophotography, and various methods of intensive use have been studied so far, but the microcapsules contain a lubricating oil and are suitable for a photoreceptor, and by destroying this The technique of releasing the lubricating oil by the microcapsules and exhibiting the abrasion resistance of the surface of the photoreceptor has not been known until now, and has been found in accordance with the present invention.

(The best form for implementing the invention)

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the drawings.

1(a) to 1(e) are conceptual cross-sectional views showing a configuration example of a photoreceptor of the present invention, wherein reference numeral 1 denotes a conductive substrate, 2 denotes an underlying layer, 3 denotes a charge generating layer, and 4 denotes a charge transporting layer, 5 As a surface protective layer, 6 is a single layer type photosensitive layer. As described above, the photosensitive layer of the photoreceptor is roughly divided into a functional separation type in which the charge generation layer 3 and the charge transport layer 4 are separated (Fig. 1 (a) to (e)), and a charge generation material and a charge transport layer. Single layer type (Fig. 1 (d), (e)). The photosensitive layers of Figs. 1(a) and (b) are negatively charged in the order in which the charge generating layer 3 and the charge transporting layer 4 are laminated. The photosensitive layer of FIG. 1(c) is a positively charged type which is laminated in the order of the charge transporting layer 4 and the charge generating layer 3, and the photosensitive layer of FIGS. 1(d) and (e). The 6 series is mainly of a single layer type and is positively charged. Here, in the present invention, the surface protective layer physically and chemically protects the surface of the photosensitive layer, and the layer-containing type of FIG. 1(b) is disposed at the outermost layer of the upper layer of the charge transporting layer 4, FIG. 1 (FIG. 1) The case of the reverse lamination type of c) is the outermost layer of the upper layer of the charge generating layer 3, and the case of the single layer type of Fig. 1(e) is the outermost layer of the upper layer of the single layer type photosensitive layer 6. The outermost layer described herein also includes a case where the outermost layer containing the charge transporting substance is provided.

In the present invention, it is important that the outermost layer of the photoreceptor contains a microcapsule containing a lubricating oil, and therefore, for example, the layer constitution shown in Fig. 1(a) is the charge transport layer 4, Fig. 1 (Fig. 1 b), (c), (e) are layered as the surface protective layer 5, and the layer shown in Fig. 1(d) is composed of a single layer type photosensitive layer 6, which is the photoreceptor The outer layer, each of which contains a microcapsule containing the lubricating oil of the present invention.

The microcapsule material of the present invention may be either inorganic or organic. Specific examples of the inorganic microcapsules may be suitably composed of inorganic porous particles, and particularly preferably hollow inorganic porous particles. This is because the hollow inorganic porous particles can contain more lubricious oil. Porous cerium oxide particles are preferably used for the inorganic porous particles.

A method of encapsulating a lubricating oil in a microcapsule composed of such an inorganic porous particle, that is, a method of microencapsulation is preferably available, for example, from Hexin Chemical Industry Co., Ltd. or Suzuki Industry Co., Ltd. A commercially available porous cerium oxide particle is impregnated with a lubricating oil while stirring.

Further, specific examples of the microcapsules of the organic substance can be suitably composed of an organic polymer material, and the organic polymer material is preferably a melamine resin or a polystyrene resin. In the method of encapsulating a lubricating oil in a microcapsule composed of such an organic polymer material, various methods known in the art can be used, and examples thereof include an interfacial polymerization method, an in-situ polymerization method, a liquid hardening method, a phase separation method, and a liquid. Medium drying method, etc.

The particle size of the microcapsules is also dependent on the thickness of the outermost layer contained, but it may be, for example, about 0.1 to 10 μm, preferably about 0.3 to 5 μm. If the particle size is too large and the layer contained is too thin, it may protrude from the surface of the layer and impair the surface properties. Further, if the particle diameter is too small, in order to obtain desired lubricity, the amount of addition must be increased, so that the efficiency is deteriorated.

Further, the lubricating oil to be used in the present invention is not particularly limited, and is preferably eucalyptus oil or fluoro oil. Specifically, the eucalyptus oil should preferably use dimethyl hydrazine oil or methyl phenyl hydrazine oil, and the fluoro oil should preferably use a fluoroether oil.

Here, the lubricating oil contained in the microcapsules is a solvent which is dissolved in a coating liquid which forms the outermost layer, and even if it is microencapsulated, there is a part in which the lubricating oil is not completely covered. If the lubricating oil is dissolved in the solvent, the outermost layer is applied, and the lubricating oil will segregate when dried. The surface reduces the effect of the present invention. Therefore, the lubricating oil is preferably one which is insoluble in the coating liquid for forming the outermost layer. In particular, it is preferably a chlorine-based solvent, a ketone solvent, an alcohol solvent, an ether solvent, or an aromatic solvent which is not dissolved in a coating liquid used for forming the outermost layer. Specifically, for example, methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, tetrahydrofuran, dichloromethane or the like is preferred. Therefore, it is effective to use an oil of eucalyptus oil or a fluorine oil, especially a solvent which dissolves almost without a fluorine oil.

Hereinafter, the specific configuration of each layer will be described in detail.

The conductive substrate 1 is a support for the other layers at the same time as the electrode of the photoreceptor, and may be any of a cylindrical shape, a plate shape, and a film shape, and may be made of aluminum, stainless steel, or nickel. A metal such as a glass, a resin, or the like is subjected to a conductive treatment.

The lower layer 2 is composed of a layer containing a resin as a main component or an oxide film such as an acid-resistant aluminum, etc., and prevents unnecessary charge injection into the photosensitive layer and the surface of the substrate from the conductive substrate, and the adhesion of the photosensitive layer is improved. For the purpose, etc., set as needed. For the resin binder using the resin as the main component of the lower layer 2, polyethylene, polypropylene, polystyrene, acrylic resin, vinyl chloride resin, vinyl acetate resin, polyurethane resin, Epoxy resin, polyester resin, melamine resin, polyoxynoxy resin, polybutyral resin, polyamide resin, and copolymers thereof. Further, metal oxide fine particles or the like may be contained in the resin binder. As the metal oxide fine particles, for example, SiO ₂ , TiO ₂ , In ₂ O ₃ , ZrO ₂ or the like can be used.

The film thickness of the lower layer 2 is also dependent on the composition of the lower layer 2, but when it is used continuously, it can be arbitrarily set in a range in which the adverse effect such as an increase in residual potential does not occur. Further, in the layer configuration shown in FIGS. 1(a) and 1(b), the lower layer 2 may not be provided.

The charge generating layer 3 is formed by vacuum-evaporating an organic photoconductive material or by coating a material in which particles of the organic photoconductive material are dispersed in a resin binder, and receives light to generate electric charges. Further, the charge generation efficiency is high and the charge generated is important for the injection property of the charge transport layer 4, and the electric field dependency is small, and it is preferable to inject the charge even at a low electric field.

The charge generating layer 3 is only required to have a charge generating function. Therefore, the film thickness is determined by the light absorption coefficient of the charge generating material, and is usually 5 μm or less, and preferably 1 μm or less. The charge generating layer 3 is mainly used as a charge generating material, and may be further added with a charge transporting substance or the like. The charge generating substance may be a phthalocyanine pigment, an azo pigment, an indole copper pigment, an anthraquinone pigment, an anthrone pigment, a squalene pigment, a thiopyranyl pigment, a quinacridone pigment, or the like. Use these pigments. In particular, the phthalocyanine-based pigment is preferably a metal-free phthalocyanine, a copper phthalocyanine, or a titanium phthalocyanine, and more preferably an X-type metal-free phthalocyanine, a τ-type metal-free phthalocyanine, an ε-type copper phthalocyanine, or a β-type titanium phthalocyanine. The CuK α: X-ray diffraction spectrum Bragg angle 2θ of the Y-type titanium phthalocyanine, JP-A-2004-2874 is a titanium phthalocyanine having a maximum peak of 9.6°.

The resin binder for the charge generating layer 3 may be suitably combined with a polycarbonate resin, a polyester resin, a polyamide resin, a polyurethane resin, an epoxy resin, a polybutyral resin, a vinyl chloride system. A copolymer, a phenolic resin, a polyoxyxylene resin, a methacrylate resin, a copolymer of these, or the like is used.

The charge transport layer 4 is a coating film composed of a material in which a charge transporting substance is dispersed in a resin binder, and in the dark portion, an electric charge of the photoreceptor is held as an insulator layer, and when receiving light, a charge-generating layer is transported. The function of the injected charge.

The charge transporting substance may be a ruthenium compound, a pyrazoline compound, a pyrazolone compound, an oxadiazole compound, an oxazole compound, an arylamine compound, a benzidine compound, a stilbene compound, or a polyethylene compound, or a polyethylene. A charge transporting polymer such as carbazole or the like.

The resin binder used in the charge transport layer 4 can be used by combining a polycarbonate resin, a polyester resin, a polystyrene resin, a polymer of a polymethacrylate, a copolymer, and the like.

The film thickness of the charge transport layer 4 is a surface potential which is practically effective, and therefore it is preferably in the range of 3 to 50 μm, more preferably 10 to 40 μm.

In the charge transport layer 4, for the purpose of improving the sensitivity or reducing the residual potential, or reducing the characteristic variation during repeated use, an electron accepting substance may be contained as needed. Examples of the electron accepting substance include succinic anhydride, maleic anhydride, dibromosuccinic anhydride, phthalic anhydride, 3-nitrophthalic anhydride, 4-nitrophthalic anhydride, pyromellitic anhydride, hexaic anhydride, trimellitic acid, A compound having a large electron affinity such as trimellitic anhydride, quinone imine, 4-nitroguanidinomine, tetracyanoethylene, tetracyanodimethylmethane, chloranil, bromoquinone, o-nitrobenzoic acid or the like.

In the charge transport layer 4, a deterioration inhibitor such as an antioxidant or a light stabilizer may be contained in order to improve environmental stability or harmful light stability. The compound used for such a purpose is exemplified by a coumarin derivative such as catechol and an esterified compound, a polyarylalkyl compound, a hydroquinone derivative, an etherified compound, a dietherified compound, and a diphenyl group. Ketone derivatives, benzotriazole derivatives, thioether compounds, phenylenediamine derivatives, phosphonates, phosphites, phenol compounds, amine phenol compounds, linear amine compounds, cyclic amine compounds, resistance Amine compounds and the like.

Further, in the charge transport layer 4, for the purpose of improving the leveling property of the formed film, a leveling agent such as eucalyptus oil or fluorine-based oil may be contained.

In the present invention, when the charge transport layer 4 is the outermost layer, it is necessary to contain a microcapsule containing the lubricating oil of the present invention in the charge transport layer 4 in order to maintain the lubricity after repeated use. The content of the microcapsules at this time may be about 0.1 to 50% by weight, preferably about 1 to 20% by weight, based on the solid content of the charge transporting layer. If the content is too small, sufficient lubricity improvement effect cannot be obtained, and if too much, the original performance of the charge transport layer may be impaired.

The photosensitive layer 6 of the single-layer type is a coating film composed of a material which disperses a charge generating substance and a charge transporting substance in a resin binder, and similarly used in the charge generating layer 3 and the charge transporting layer 4 described above. material. The film thickness is a practically effective surface potential, and is preferably in the range of 3 to 50 μm, more preferably 10 to 40 μm.

The photosensitive layer 6 may contain an electron-accepting substance as needed in the same manner as the charge transport layer 4 for the purpose of improving sensitivity or reducing residual potential or reducing variations in characteristics during repeated use. The electron accepting substance may, for example, be succinic anhydride, maleic anhydride, dibromosuccinic anhydride, phthalic anhydride, 3-nitrophthalic anhydride, 4-nitrophthalic anhydride, pyromellitic anhydride, hexaic anhydride, trimellitic acid, Trimellitic anhydride, quinone imine, 4-nitroguanidino A compound having a large electron affinity such as tetracyanoethylene, tetracyanodimethylmethane, chloranil, bromoquinone or o-nitrobenzoic acid.

In the photosensitive layer 6, in order to improve the environmental stability or the light stability of the light, the deterioration inhibitor such as an antioxidant or a light stabilizer may be contained in the same manner as the charge transport layer 4 described above. The compound used for such a purpose is exemplified by a coumarin derivative such as catechol and an etherified compound, an esterified compound, a polyarylalkyl compound, a hydroquinone derivative, a dietherified compound, and a diphenyl group. A ketone derivative, a benzotriazole derivative, a thioether compound, a phenylenediamine derivative, a phosphonate, a phosphite, a hindered amine compound, and the like.

Further, in the photosensitive layer 6, for the purpose of improving the leveling property of the formed film, a leveling agent such as eucalyptus oil or fluorine-based oil may be contained in the same manner as the charge transport layer 4 described above.

Further, when the photosensitive layer 6 is the outermost layer, in order to maintain the lubricity after repeated use, the photosensitive layer 6 contains a microcapsule containing the lubricating oil of the present invention. The content of the microcapsules at this time may be about 0.1 to 50% by weight, preferably about 1 to 20% by weight, based on the solid content of the photosensitive layer 6. If the content is too small, sufficient lubricity improvement effect cannot be obtained, and if too much, the original performance of the photosensitive layer may be impaired.

The surface protective layer 5 generally has excellent lubricity and excellent durability against mechanical stress, and is further composed of a chemically stable substance, and has a function of receiving and maintaining a charge of corona electricity in a dark place, and has a transmitted charge generation. The performance of the light induced by the layer 3, transmitted through the light upon exposure, reaches the charge generating layer 3, and is neutralized by the injection of the generated charge to neutralize the surface charge. Moreover, the material used is as described above, and the absorption of light in the charge generating substance is extremely large. The wavelength region should be as transparent as possible. When the film thickness of the surface protective layer 5 is continuously used repeatedly, it can be arbitrarily set within a range in which no adverse effect such as an increase in residual potential occurs, but it is, for example, about 0.1 to 10 μm, preferably in the range of 1 to 8 μm.

The surface protective layer 5 can be set as shown in Figs. 1(b), (c) and (e), and is not required in the present invention, but must be the outermost layer when it is disposed. Therefore, the material of the surface protective layer 5 is to maintain the lubricity after repeated use, and it is necessary to use a material containing microcapsules containing the lubricating oil of the present invention.

The material of the surface protective layer 5 is a microcapsule containing a lubricating oil, and it is necessary to use a resin binder and, if desired, any one or both of a reinforcing filler and a conductivity adjusting agent.

The resin binder of the surface protective layer 5 is preferably a curable resin, and particularly, a thermosetting resin and a photocurable resin are effective, and specifically, for example, an epoxy resin, a urethane resin, or a cyanate ester is hardened. A thermosetting resin such as a material (also known as cyanide resin).

The epoxy resin is preferably, for example, an alkoxy-containing decane-modified epoxy resin. Specifically, a bisphenol-type epoxy resin or a novolak-type epoxy resin and an alkoxydecane partial condensate may be suitably used. A cured product of a mixture of an epoxy resin and an alkoxysilane obtained by an alcohol condensation reaction. Such a decane-modified epoxy resin containing an alkoxy group can be suitably used, and has the following formula (1),

(In the formula (1), R ¹ represents CH ₂ , C(CH ₃ ) ₂ , CH(CH ₃ ), C(CF ₃ ) ₂ , O, SO ₂ , S, and R ² and R ³ each independently represent carbon. Alkoxy groups of 1 to 3 or alkyl groups having 1 to 2 carbon atoms, R ⁴ represents an alkyl group having 1 to 2 carbon atoms, n represents an integer of 0 to 100, and m represents an integer of 1 to 20 or the following Formula (2)

(In the formula (2), R ⁵ represents CH ₂ , C(CH ₃ ) ₂ , CH(CH ₃ ), C(CF ₃ ) ₂ , O, SO ₂ , S, and R ⁶ and R ⁷ each independently represent carbon. a structure represented by alkoxy groups of 1 to 3 or alkyl groups having 1 to 2 carbon atoms, R ⁸ represents an alkyl group having 1 to 2 carbon atoms, p represents an integer of 0 to 100, and q represents an integer of 1 to 20) By. Specifically, for example, those shown by the following formulas (1-1) and (2-1) are mentioned.

The epoxy resin is generally insufficient in strength and the like, and the lack of lubricity of the resin itself causes a large surface damage, and the durability is not satisfied, and the toner tends to adhere, so that the film tends to be easily formed. However, the alkoxy-containing decane-modified epoxy resin has the advantage of being large in strength and reducing the surface damage. In particular, the cured product of the above-mentioned epoxy resin and alkoxydecane is a composite of the crosslinking by the epoxy group of the epoxy resin and the alkoxysilane, and the crosslinking is complicated. Strong structure, so it can suppress surface damage. Further, for the adhesion of the toner, since the surface energy of the resin is small, the toner is hard to adhere. That is, the decane-modified epoxy resin containing an alkoxy group is difficult to remain on the surface coloring powder although it has little surface damage, and has a feature that it does not cause film formation, so it can be effectively used as the surface protective layer 5 Resin binder.

The alkoxy-containing decane-modified epoxy resin is preferably added with a curing agent for an epoxy resin portion, a curing accelerator, a curing accelerator for an alkoxydecane portion, and the like as needed. The curing agent for the epoxy resin portion may, for example, be an acid anhydride or an amine, and the curing accelerator may, for example, be a tertiary amine. The hardening accelerator of the alkoxy decane part may, for example, be a metal complex such as tin octylate.

Further, in the present invention, the ratio of the alkoxydecane moiety in the mixed material of the epoxy resin and the alkoxydecane is preferably in the range of 10 to 50% by weight. When the proportion of the alkoxydecane moiety is 10% by weight, the crosslinking portion due to the condensation of the alkoxydecane moiety is small, and the reinforcing effect of the epoxy resin cannot be obtained. On the other hand, when it exceeds 50% by weight, the crosslinking density becomes too large and becomes brittle, and the amount of film damage on the surface of the photoreceptor increases.

Further, the urethane resin is preferably a fluorine-containing polyol. The urethane resin generally has a large surface energy, so that the toner tends to adhere and is likely to be film-formed. However, when the fluorine-containing polyol is used for hardening, the energy of the surface can be reduced, and film formation is difficult. Further, since the urethane resin has a large toughness, it has an advantage that it is difficult to be cut.

Further, a cured product of cyanate ester can be suitably used in the following formula (3),

(In the formula (3), R ⁹ represents an aromatic organic group, and r represents an integer of 2 or 3) and the cyanate compound is a polymer which is hardened. In particular, as in the following general formula (4)

(In the formula (4), R ^{1 0} represents a bisphenol skeleton as represented by CH ₂ , C(CH ₃ ) ₂ , CH(CH ₃ ), C(CF ₃ ) ₂ , O, SO ₂ , and S). The cyanate ester is a bifunctional cyanate compound. When the cyanate ester is trifunctional or more, the crosslink density of the cured product is too high, and the cured product becomes brittle, and the printing durability is deteriorated. Even if it has a bisphenol skeleton for strength, it is effective.

Specific examples of the cyanate compound represented by the above formula (4) can be suitably exemplified by the following formulas (4-1) to (4-4).

The cured product of such a cyanate ester has high hardness and high strength, so that it is difficult to be cut and it is difficult to scratch. Moreover, since the surface energy is small due to the symmetrical structure, the toner is hard to adhere, and there is an advantage that film formation is small. An organometallic compound such as zinc octylate, tin octylate, zinc acetoacetate, iron acetonitrile, dibutyltin dimaleate or the like, aluminum chloride or tin chloride is added to the cyanate esters as needed. A metal salt such as zinc chloride, an amine such as trivinyldiamine or dimethylbenzylamine is more effective.

In such a curable resin, an alcohol solvent such as methanol can be used as a diluent solvent for the coating liquid. Therefore, it is effective even if the solvent dissolves the surface of the photosensitive layer of the lower layer. Further, these curable resins may be used singly or in combination with other curable resins, and are not particularly limited.

Specific examples of the reinforcing filler used in the present invention are inorganic fibers (crystal wires), organic fibers, crosslinked acrylic resin particles, crosslinked polystyrene fine particles, high molecular polyethylene fine particles, polyimine fine particles or methyl groups. The polyoxymethylene resin fine particles and the like are effective, but are not limited thereto. By dispersing these reinforcing fillers in the resin binder, the strength, hardness and toughness of the surface protective layer 5 are increased, and the friction coefficient of the surface can also be reduced.

Further, in the conductive modifier added to the surface protective layer 5 in the present invention, metal oxide fine particles, metal fine particles, polymer fine particles coated with a conductive material, or a charge transporting substance can be used.

Further, the content of the microcapsules in the surface protective layer 5 may be from about 0.1 to 50% by weight, preferably from 1 to 20% by weight, more preferably from about 5 to 15% by weight, based on the solid content of the surface protective layer 5. If the content is too small, sufficient lubricity improvement effect cannot be obtained, and if too much, the damage and the original performance of the surface protective layer are excessive.

(Example)

Next, an embodiment of the photoreceptor for electrophotography of the present invention will be described. In addition, in the following, "parts" means "parts by weight".

(Modulation of microcapsules containing lubricating oil) (Modulation example 1)

Prepare a microcapsule manufactured by Japan Microproducts and containing various lubricating oils. The microcapsule is made of melamine resin and has a particle size of 3-5 μm. As the lubricative oil, those of TSF451 (dimethyl sulfonate oil, GE Toshiba Silicon Co., Ltd.) were used as the microcapsule A, and J25 (FLUID) (fluoroether oil or NOK (manufactured by the company) was used as the microcapsule B.

(Modulation example 2)

In the Hutchison Microcapsules (hollow porous cerium oxide particles, particle size 2 to 5 μm) manufactured by Hexin Chemical Industry Co., Ltd., TSF451 (dimethyl sulfonate oil, GE Toshiba Silicon Co., Ltd.) is used as the lubricating oil. As the microcapsule C, a person who uses J25 FLUID (fluoroether type oil, NOK (manufactured by NOK)) is used as the microcapsule D.

(Modulation Example 3)

A SX866 (A) (hollow granular polystyrene, particle size ψ 0.3 μm) manufactured by JSR Co., Ltd. was prepared and impregnated with various lubricating oils. For the lubricating oil, TSF451 (dimethyl phthalate oil, GE Toshiba Silicon Co., Ltd.) was used as the microcapsule E to use F.

(Modulation of resin binder solution) (Modulation Example 4)

Weigh and mix an epoxy resin/alkoxydecane-based mixed material (trade name: compoceran E102: manufactured by Arakawa Chemical Co., Ltd., in the above formula (1), R ¹ = C(CH ₃ ) ₂ , R ² = OCH ₃ 75 parts of a compound of R ³ =OCH ₃ and R ⁴ =CH ₃ (specific example (1-1)), 9 parts of an acid anhydride (trade name: Rikacid HM-700, manufactured by Nippon Chemical and Chemical Co., Ltd.) as a curing agent, 0.8 parts of tin octylate as a promoter, 0.4 parts of DBU (1,8-diazabicyclo(5,4,0)undecene-7), 100 parts of methanol as a solvent, and 50 parts of methyl ethyl ketone. Become a resin binder solution A.

(Modulation Example 5)

Weighing and mixing 18 parts of HDI derivative block isocyanate (trade name: Duranate MF-K-60X, manufactured by Asahi Kasei Chemicals Co., Ltd.), and fluorine-containing polyol (trade name: Lumiflon-200, manufactured by Asahi Glass Co., Ltd.), and 50 parts of methyl ethyl ketone as a solvent became the resin binder solution B.

(Modulation Example 6)

Weighing and mixing 55 parts of bisphenol E type cyanate (trade name: Arocy L-10 Vantico, compound represented by the above formula (4-1)), 0.3 parts of zinc acetoacetate ligand as a catalyst, The resin binder solution C was formed by using 180 parts of methyl ethyl ketone as a solvent.

(Modulation Example 7)

60 parts of phenolic resin (trade name: PR-912, manufactured by Sumitomo Becklite Co., Ltd.) and 100 parts of isopropyl alcohol as a solvent were weighed to form a resin binder solution D.

(Modulation Example 8)

A bisphenol resin Z-type polycarbonate resin (trade name: Panlite TS2050, manufactured by Teijin Chemicals Co., Ltd.) and 400 parts of methylene chloride as a solvent were weighed to form a resin binder solution E.

(Modulation Example 9)

60 parts of a mixed epoxy resin (trade name: THB9502; manufactured by Kea Chemical Co., Ltd.) and 100 parts of xylene as a solvent were weighed to form a resin binder solution F.

(Modulation Example 10)

Weigh and mix epoxy resin/alkoxydecane-based mixed material (trade name Compoceran E112: manufactured by Arakawa Chemical Co., Ltd., R ⁵ =C(CH ₃ ) ₂ , R ⁶ =OCH ₃ in the above formula (2) 75 parts of a compound of R ⁷ =OCH ₃ and R ⁸ =CH ₃ (specific example (2-1)), 9 parts of an acid anhydride (trade name: Rikacid HM-700, manufactured by Nippon Chemical and Chemical Co., Ltd.) as a curing agent, 0.8 parts of tin octylate as a promoter, 0.4 parts of DBU (1,8-diazabicyclo(5,4,0)undecene-7), 100 parts of methanol as a solvent, and 50 parts of methyl ethyl ketone. Become a resin binder solution G.

(Example 1)

A drum photoreceptor (Φ 30 mm) was produced in the following order for evaluation of electrical characteristics.

First, an underlayer dispersion having the following composition was applied by dipping on an aluminum tube, and dried at 100 ° C for 30 minutes to remove the solvent to form a lower layer having a thickness of 3 μm.

(underlying layer dispersion composition)

Resin Adhesive: Alcohol-soluble nylon (CM8000, manufactured by Toray Co., Ltd.) 5 parts Additive: titanium oxide fine particles treated with amino decane 5 parts Solvent: methanol/dichloromethane mixed solvent (6/4 (volume ratio)) 90 copies

Next, the charge generating layer dispersion having the following composition was applied by dipping, and dried at 100 ° C for 30 minutes to remove the solvent to form a charge generating layer having a film thickness of 0.3 μm.

(charge generation layer dispersion composition)

Charge generating substance: titanium phthalocyanine 11 parts of resin binder: chlorinated ethylene-based copolymer resin (MR-110, manufactured by Zeon, Japan) 1 part solvent: dichloromethane 98 parts

Next, the charge transport layer solution having the following composition was dip-coated, and dried at 100 ° C for 30 minutes to remove the solvent to form a charge transport layer having a film thickness of 0.3 μm.

(charge transport layer solution composition)

Charge transporting substance: bismuth compound (CTC191, manufactured by Takasago Co., Ltd.) 9 parts charge transport layer: butadiene compound (T405, manufactured by Takasago Co., Ltd.) 1 part resin binder: bisphenol Z type polycarbonate resin (trade name: panlite TS2050, manufactured by Teijin Chemical Co., Ltd.) 10 parts solvent: 90 parts of dichloromethane

Next, the surface protective layer dispersion having the following composition was applied by dipping, dried at 80 ° C for 30 minutes, and further dried at 110 ° C for 1 hour to remove the solvent to form a surface protective layer having a film thickness of 4 μm.

(surface protective layer dispersion composition)

Resin Adhesive Solution: Resin Adhesive Solution A (Adjustment Example 4) 235.2 parts Microcapsules containing lubricating oil: Microcapsule A (Adjustment Example 1) 20 parts of conductivity adjusting agent: Tin Oxide (Nanotek Powder SnO ₂ , CIK into a (share) system) 20 copies

A photoreceptor for electrophotography was produced as described above.

(Examples 2 to 14)

The combination of the resin binder solution A and the microcapsule A in the composition of the surface protective layer dispersion of Example 1 and the amount of tin oxide as the conductivity adjuster were changed as shown in Table 1 below, and dried. The conditions were changed to 80 ° C / 30 minutes + 110 ° C / 1 hour, as shown in the following Table 1, and the same procedure as in Example 1 was carried out to prepare a photoreceptor for electrophotography.

(Examples 15 and 16)

The same procedure as in Examples 1 and 7 was carried out except that 15 parts of crosslinked polystyrene (SX8742: Φ 0.3 μm, manufactured by JSR) as a reinforcing filler was further added to the surface protective layer dispersions of Examples 1 and 7. A photoreceptor for electrophotography was produced.

(Comparative examples 1 to 3)

The photoreceptor for electrophotography was produced in the same manner as in Example 1 except that the microcapsules A were not added to the surface protective layer dispersions of Examples 1 to 3.

(Comparative Example 4)

In the same manner as in Example 1, except that 7 parts of the substituted microcapsules A of dimethyl hydrazine oil (TSF451, GE Toshiba Silicone Co., Ltd.) were added to the surface protective layer dispersion liquid of Example 1, the same procedure as in Example 1 was carried out to prepare an electrophotographic film. Photoreceptor.

(Comparative Example 5)

A photoreceptor for electrophotography was produced in the same manner as in Example 1 except that the surface protective layer was not provided.

The surface protective layer dispersion composition and drying conditions of the respective examples and comparative examples are shown in Table 1 below.

With respect to the photoreceptors produced in the examples and the comparative examples, the friction coefficient was evaluated as an index of lubricity, and the amount of film damage was used as an index of the printing resistance, and the presence or absence of film formation was an indicator of image defects. The results of these are shown in Table 2 below.

The evaluation of the printing durability is as shown in FIG. 2, and a urethane cleaning blade 11 made of Beichang Industrial Co., Ltd. is disposed around the photosensitive drum 10 (photosensitive body) 10, and the color is evaluated. The powder box 12 and the toner charging roller 13 are formed by a device. Specifically, the crimp angle 25 is used. The cleaning blade 11 was brought into contact with the photosensitive drum 10, and the photosensitive drum 10 was rotated at a rotation speed of 210 rpm (100,000 rotations), and the amount of film damage on the surface of the photosensitive drum 10 of the cleaning blade 11 was evaluated as an index of the printing durability. Further, reference numeral 14 in Fig. 2 denotes a magnetic one-component toner.

Further, the presence or absence of film formation in the surface of the feeling drum 10 after 100,000 rotations was confirmed by visual observation. Further, using the size (1.0) of the frictional resistance of the surface of the conventional photosensitive drum (Comparative Example 5 in which the surface protective layer is not provided), the surface of the photosensitive drum 10 after the 100,000 rotations was determined for the urethane scraper. The magnitude of the frictional resistance is taken as a relative comparison value. Further, the measurement of the friction resistance was carried out by using a surface measuring machine (HEIDON-14DR, manufactured by Shinto Scientific Co., Ltd.) shown in Fig. 3 . Reference numeral 15 in Fig. 3 denotes a load detector.

From the results shown in the above 2, the photoreceptor of Examples 1 to 15 of the present invention has a friction resistance value of 0.4 to 0.6, and maintains its value after operation (100,000 rotations), and maintains good lubrication with stability. Sex. However, the photoreceptor of Comparative Examples 1 to 3 in which no microcapsules containing a lubricating oil were added, and the photosensitive system of Comparative Example 5 in which no surface protective layer was provided had a friction resistance value as large as 0.9 to 1.0, and was directly added. The photoreceptor of Comparative Example 4 of the lubricating oil had a friction resistance value as small as 0.4 before the operation, but increased to 0.8 after the operation. Therefore, as a result of the above, it was confirmed that the addition of a microcapsule containing a lubricating oil therein is effective for maintaining the stability of the lubricity in repeated use.

Further, in the photoreceptors of Comparative Examples 1, 2, and 4, film formation occurred, and in the photoreceptor of Comparative Example 5, film formation was not caused, but the amount of film damage was increased. However, the photoreceptor of Examples 1 to 15 in which a microcapsule containing a lubricating oil is added is added, and the amount of film damage is small, and the addition of the microcapsule containing the lubricating oil of the present invention does not occur. Improvements in brush resistance and image quality are also effective.

[Industry use possibility]

As described above, according to the present invention, it is excellent in lubricity, is difficult to be cut, and has a surface that is hard to be damaged, and further prevents occurrence of image defects caused by film formation or the like, and can obtain toner detachment. A good high-resistance photoreceptor for electrophotography. The photoreceptor for electrophotography of the present invention can be used for various image forming apparatuses such as an electrophotographic printer, a photocopier, and a facsimile machine.

1. . . Conductive matrix

2. . . Lower layer

3. . . Charge generation layer

4. . . Charge transport layer

5. . . Surface protection layer

6. . . Single layer photosensitive layer

10. . . Drum (photoreceptor)

11. . . Cleaning blade

12. . . Toner box

13. . . Toner charging roller

14. . . Magnetic one component toner

15. . . Load detector

1(a) to 1(e) are schematic cross-sectional views showing a configuration example of a photoreceptor for electrophotography of the present invention, and (a) and (b) are diagrams showing a photoreceptor having a negatively-charged functional separation type. In the configuration, (c) shows a configuration of a photoreceptor having a positively-charged functional separation type, and (d) and (e) shows a configuration of a photoreceptor having a positively-charged single-layer type.

Fig. 2 is a schematic explanatory view showing an apparatus for evaluating the printing durability in the embodiment.

Fig. 3 is a schematic explanatory view showing a measuring device (surface measuring machine) for a frictional resistance of the embodiment.

Claims (21)

A photoreceptor for electrophotography, which is a photoreceptor for electrophotography having at least a photosensitive layer on a conductive substrate, and is characterized in that it contains a lubricating oil in a solid portion of the outermost layer of the photoreceptor with respect to the outermost layer. The capsule is 0.1 to 50% by weight, and the microcapsules are composed of inorganic porous particles. The photoreceptor for electrophotography according to the first aspect of the invention, wherein the inorganic porous particles are hollow. The photoreceptor for electrophotography according to the first or second aspect of the invention, wherein the inorganic porous particles are porous cerium oxide particles. A photoreceptor for electrophotography, which is a photoreceptor for electrophotography having at least a photosensitive layer on a conductive substrate, and is characterized in that it contains a lubricating oil in a solid portion of the outermost layer of the photoreceptor with respect to the outermost layer. 0.1 to 50% by weight of the capsule, wherein the microcapsule is composed of an organic polymer material, and the photosensitive layer is provided with a surface protective layer as the outermost layer, and the surface protective layer contains a curable resin, and the curable resin is a ring. An epoxy resin, a urethane resin, or a cured product of a cyanate ester, wherein the epoxy resin is an alkoxy-containing decane-modified epoxy resin, and the alkoxy-containing decane-modified epoxy resin has the following General formula (1) (In the formula (1), R ¹ represents CH ₂ , C(CH ₃ ) ₂ , CH(CH ₃ ), C(CF ₃ ) ₂ , O, SO ₂ , S, and R ² and R ³ are each independently represented. An alkoxy group having 1 to 3 carbon atoms or an alkyl group having 1 to 2 carbon atoms, R ⁴ represents an alkyl group having 1 to 2 carbon atoms, n is an integer of 0 to 100, m is an integer of 1 to 20 or the following General formula (2) (In the formula (2), R ⁵ represents CH ₂ , C(CH ₃ ) ₂ , CH(CH ₃ ), C(CF ₃ ) ₂ , O, SO ₂ , S, and R ⁶ and R ⁷ are each independently represented. An alkoxy group having 1 to 3 carbon atoms or an alkyl group having 1 to 2 carbon atoms, R ⁸ is an alkyl group having 1 to 2 carbon atoms, p is an integer of 0 to 100, and q is an integer of 1 to 20) structure. The photoreceptor for electrophotography according to the fourth aspect of the invention, wherein the organic polymer material is a melamine resin or a polystyrene resin. The photoreceptor for electrophotography according to claim 1 or 4, wherein the lubricating oil is eucalyptus oil. The photoreceptor for electrophotography according to claim 6, wherein the eucalyptus oil is dimethyl hydrazine oil or methyl phenyl hydrazine oil. The photoreceptor for electrophotography according to claim 1 or 4, wherein the lubricating oil is a fluorine oil. The photoreceptor for electrophotography according to the eighth aspect of the invention, wherein the fluoro oil is a fluoroether oil. The photoreceptor for electrophotography according to the first aspect of the invention, wherein the photosensitive layer is provided with a surface protective layer as the outermost layer. The photoreceptor for electrophotography according to claim 10, wherein the surface protective layer contains a curable resin. The photoreceptor for electrophotography according to the eleventh aspect of the invention, wherein the curable resin is an epoxy resin, a urethane resin, or a cured product of a cyanate ester. The photoreceptor for electrophotography according to claim 12, wherein the epoxy resin is an alkoxy-containing decane-modified epoxy resin. The photoreceptor for electrophotography according to claim 13, wherein the alkoxy-containing decane-modified epoxy resin has the following general formula (1) (In the formula (1), R ¹ represents CH ₂ , C(CH ₃ ) ₂ , CH(CH ₃ ), C(CF ₃ ) ₂ , O, SO ₂ , S, and R ² and R ³ are each independently represented. An alkoxy group having 1 to 3 carbon atoms or an alkyl group having 1 to 2 carbon atoms, R ⁴ represents an alkyl group having 1 to 2 carbon atoms, n is an integer of 0 to 100, m is an integer of 1 to 20 or the following General formula (2) (In the formula (2), R ⁵ represents CH ₂ , C(CH ₃ ) ₂ , CH(CH ₃ ), C(CF ₃ ) ₂ , O, SO ₂ , S, and R ⁶ and R ⁷ are each independently represented. An alkoxy group having 1 to 3 carbon atoms or an alkyl group having 1 to 2 carbon atoms, R ⁸ is an alkyl group having 1 to 2 carbon atoms, p is an integer of 0 to 100, and q is an integer of 1 to 20) structure. The photoreceptor for electrophotography according to Item 4, 13 or 14, wherein the alkoxy-containing decane-modified epoxy resin is a cured product of a mixture of an epoxy resin and an alkoxy decane, and The ratio of the alkoxydecane moiety in the mixed material is 10 to 50% by weight. The photoreceptor for electrophotography according to Item 4 or 12, wherein the hardened substance of the cyanate ester is a compound of the following formula (3) (In the formula (3), R ⁹ represents an aromatic organic group, and r represents an integer of 2 or 3) and the cyanate compound is a polymer which is hardened. The photoreceptor for electrophotography according to the fourth or twelfth aspect of the invention, wherein the urethane resin is a fluorine-containing polyol. The photoreceptor for electrophotography according to the fourth or tenth aspect of the invention, wherein the surface protective layer contains either or both of a reinforcing filler and a conductivity adjusting agent. The photoreceptor for electrophotography according to the first aspect of the invention, wherein the photosensitive layer is a laminated type in which a charge generating layer and a charge transporting layer are laminated, and the charge transporting layer is the outermost layer. The photoreceptor for electrophotography according to the first aspect of the invention, wherein the photosensitive layer is a single layer type containing a charge generating substance and a charge transporting substance, and the photosensitive layer is the outermost layer. A photoreceptor for electrophotography, which is a photoreceptor for electrophotography having at least a photosensitive layer on a conductive substrate, and is characterized in that it contains a lubricating oil in a solid portion of the outermost layer of the photoreceptor with respect to the outermost layer. The capsule is composed of 0.1 to 50% by weight, and the microcapsules are composed of inorganic porous particles. The photosensitive layer is provided with a surface protective layer as the outermost layer, and the surface protective layer contains a curable resin. The curable resin is an epoxy resin, a urethane resin, or a cured product of a cyanate ester, and the epoxy resin is an alkoxy-containing decane-modified epoxy resin, and the alkoxy-containing decane is modified. Epoxy resin having the following general formula (1) (In the formula (1), R ¹ represents CH ₂ , C(CH ₃ ) ₂ , CH(CH ₃ ), C(CF ₃ ) ₂ , O, SO ₂ , S, and R ² and R ³ are each independently represented. An alkoxy group having 1 to 3 carbon atoms or an alkyl group having 1 to 2 carbon atoms, R ⁴ represents an alkyl group having 1 to 2 carbon atoms, n is an integer of 0 to 100, m is an integer of 1 to 20 or the following General formula (2) (In the formula (2), R ⁵ represents CH ₂ , C(CH ₃ ) ₂ , CH(CH ₃ ), C(CF ₃ ) ₂ , O, SO ₂ , S, and R ⁶ and R ⁷ are each independently represented. An alkoxy group having 1 to 3 carbon atoms or an alkyl group having 1 to 2 carbon atoms, R ⁸ is an alkyl group having 1 to 2 carbon atoms, p is an integer of 0 to 100, and q is an integer of 1 to 20) structure.