JP2004046222A - Electrophotographic photosensitive body, process cartridge and electrophotographic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photosensitive body having excellent abrasion resistance and hardness capable of preventing the generation of flaws without adding a curing catalyst and having a curing type surface layer capable of preventing the original charge transportability of the electrophotograhic photosensitive body from being reduced, to provide a process cartridge having the electrophotographic photosensitive body, and to provide an electrophotographic device. <P>SOLUTION: A surface layer of the electrophotographic photosensitive body contains a polymer obtained by polymerizing at least one of a charge transporting substance and conductive particles and at least one component selected from a group consisting of polyhydroxy methyl bisphenol monomers of specific structure, polyhydroxy methyl bisphenol oligomers of specific structure, polyhydroxy method trisphenol monomers of specific structure, and polyhydroxy methyl trisphenol oligomers of specific structure. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to an electrophotographic photosensitive member, a process cartridge having the electrophotographic photosensitive member, and an electrophotographic apparatus.

An electrophotographic photosensitive member used in an electrophotographic apparatus is required to have predetermined sensitivity, electrical characteristics, and optical characteristics according to an electrophotographic process. Since electric and mechanical external forces such as charging, development with toner, transfer to a transfer material, and cleaning of residual toner are directly applied, durability against them is required. Specifically, durability against scratches and abrasion due to rubbing, especially when using a charging method involving electric discharge, durability against chemical degradation due to ozone and nitrogen oxides that are significantly generated under high humidity Is required. Further, at the time of cleaning the remaining toner, there are problems such as toner adhesion to the surface of the electrophotographic photoreceptor and turning up of the blade when performing blade cleaning. Therefore, characteristics such as surface slipperiness, releasability, and contamination resistance are required. You.

In order to meet such demands, as materials for the surface layer of the electrophotographic photoreceptor, resins such as fluorine atom-containing resins having excellent release properties and slipperiness, silicone resins, urethane resins, and unsaturated resins It has been proposed to use a high-hardness resin material such as an ester material.

However, a material that satisfies the various properties described above has not yet been found. For example, the hardness of a fluorine atom-containing resin alone is low and it is difficult to suppress the occurrence of scratches. Further, since a fluorine atom-containing resin is hardly soluble in a general solvent, film formation is not easy.

Japanese Patent Application Laid-Open No. 61-07257 discloses an example in which a high-hardness material such as a curable silicone resin utilizing the high reactivity of alkoxysilane is used for an electrophotographic photosensitive member. Curable materials were not sufficient in terms of slipperiness, electrical properties under high humidity, and mold release properties. Furthermore, since these curable materials have high reactivity with hydroxyl groups, there are restrictions on the solvent when forming the photosensitive layer by coating, and the curing reaction gradually progresses due to the influence of moisture. The stability of the solution was also poor, and there was a problem in the productivity of the electrophotographic photosensitive member.

Further, the material disclosed in JP-A-62-014657, which forms a cured film using cleavage of unsaturated bonds such as a prepolymer of diallyl phthalate resin, is generally radically polymerizable, Although the coating liquid using this material is relatively stable against moisture, poor curing on the film surface due to the polymerization inhibition effect of oxygen in the air, and carbon-carbon bonding due to light irradiation when using a photoinitiator Only a cured product having unstable electrical properties such as insulation resistance can be obtained by a cutting reaction of the resin. For this reason, there have been problems such as a decrease in transfer efficiency due to an increase in surface free energy of the electrophotographic photosensitive member and an image blur due to moisture absorption.

On the other hand, as the material used for the surface layer of the electrophotographic photoreceptor, not only the above-described surface properties such as hardness, rubbing resistance and slipperiness, but also so that the movement of electric charges is not stagnated inside the surface layer. Electrical characteristics are required. If the surface layer of the electrophotographic photosensitive member does not have a function of transferring charges, charges are accumulated inside the photosensitive layer, and the charge-exposure electrophotographic process is repeated to cause an increase in the residual potential, resulting in an output image. Will degrade the quality.

In order to solve this point, a method of including a charge transport material in the surface layer has been proposed.For example, when a charge transport material is added to alkoxysilane and curing is performed, a siloxane component of the alkoxysilane is used. When the charge transport material is contained in a resin containing a highly polar unit such as a urethane resin, the charge mobility due to the charge transport material is reduced. In fact, satisfactory electrophotographic characteristics cannot be obtained.

Furthermore, among thermosetting resins, there are various materials in which a heat treatment is not sufficient, and a curing catalyst such as a curing accelerator or a polymerization initiator must be added. However, when such a curing catalyst remains in the cured film, there is a possibility that even a small amount of the curing catalyst may hinder the transfer of electric charges, or may cause an adverse effect such as a decrease in electric resistance of the cured film.

In addition, the coating liquid to which the curing catalyst is added tends to cause a gradual reaction even at room temperature. As a result, the stability of the coating liquid is deteriorated, and it is difficult to manufacture and store a large amount of the coating liquid. Also occurs.

Japanese Patent Application Laid-Open No. 10-228126 discloses an example in which a charge transport material having a hydroxyphenyl group or a hydroxyalkyl group is contained in the surface layer of an electrophotographic photosensitive member. The body has not yet responded to recent demands for high durability, high productivity, and high image quality, and it has not been able to fully satisfy all aspects of mechanical strength, residual potential, and productivity. It is a fact.
JP-A-61-072257 JP-A-62-014657 JP-A-10-228126

An object of the present invention is to provide a curable surface layer having excellent abrasion resistance without adding a curing catalyst, having a hardness sufficient to prevent scratches and the like, and not deteriorating the charge transportability inherent in an electrophotographic photoreceptor. To provide an electrophotographic photoreceptor having:

Another object of the present invention is to provide an electrophotographic photoreceptor having a surface layer that can be coated with high productivity.

Another object of the present invention is to provide a process cartridge and an electrophotographic apparatus having the above electrophotographic photosensitive member.

The present invention relates to an electrophotographic photosensitive member having a photosensitive layer on a support,
The surface layer of the electrophotographic photoreceptor,
At least one of a charge transport material and conductive particles,
Polyhydroxymethylbisphenol monomer having 2 to 3 benzene rings and 2 to 4 hydroxymethyl groups, having a structure in which a bisphenol monomer having 2 to 3 benzene rings is condensed, and having 2 to 4 hydroxymethyl Condensation of a polyhydroxymethylbisphenol oligomer having a group, a polyhydroxymethyltrisphenol monomer having 3 to 4 benzene rings and 2 to 6 hydroxymethyl groups, and a trisphenol monomer having 3 to 4 benzene rings And a polymer obtained by polymerizing at least one selected from the group consisting of polyhydroxymethyl trisphenol oligomers having 2 to 6 hydroxymethyl groups having a structure as described above. It is a photoreceptor.

Further, the present invention is a process cartridge and an electrophotographic apparatus having the above electrophotographic photosensitive member.

According to the present invention, without adding a curing catalyst, it is excellent in abrasion resistance, has a hardness enough to prevent scratches and the like, and furthermore, a curable surface layer which does not reduce the original charge transportability of the electrophotographic photoreceptor. Can be provided.

According to the present invention, it is possible to provide an electrophotographic photoreceptor having a surface layer that can be coated with high productivity.

According to the present invention, it is also possible to provide a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

Hereinafter, the present invention will be described in more detail.

The photosensitive layer of the electrophotographic photoreceptor of the present invention may be a single-layer photosensitive layer containing a charge generating substance and a charge transporting substance in a single layer, even if the charge generating layer contains the charge generating substance and the charge transporting substance. It may be a laminated photosensitive layer in which a charge transport layer containing a substance is laminated.

FIG. 1 shows an example of the layer structure of the electrophotographic photoreceptor of the present invention.

The electrophotographic photoreceptor having the layer structure shown in FIG. 1A is provided with a charge generation layer 3 and a charge transport layer 2 on a support 4 in order, and further has a charge transport material as a surface layer thereon. And at least one of the conductive particles and a polyhydroxymethylbisphenol monomer having 2 to 3 benzene rings and 2 to 4 hydroxymethyl groups (in the present invention, simply referred to as a polyhydroxymethylbisphenol monomer); A polyhydroxymethylbisphenol oligomer having a structure in which a bisphenol monomer having three benzene rings is condensed and having 2 to 4 hydroxymethyl groups (in the present invention, also simply referred to as a polyhydroxymethylbisphenol oligomer); Pos with 4 benzene rings and 2 to 6 hydroxymethyl groups Hydroxymethyl trisphenol monomer (in the present invention, also simply referred to as polyhydroxymethyl trisphenol monomer) having a structure in which trisphenol monomers having 3 to 4 benzene rings are condensed and having 2 to 6 hydroxymethyl groups A layer 1 containing a polymer obtained by polymerizing a polyhydroxymethyl trisphenol oligomer having the following formula (in the present invention, also simply referred to as a polyhydroxymethyl trisphenol oligomer).

Further, as shown in FIGS. 1B and 1C, an intermediate layer (barrier layer, adhesive layer) 5 having a barrier function or an adhesive function, a method for preventing interference fringes between the support 4 and the charge generation layer 3. A conductive layer 6 or the like for the purpose may be provided.

Further, the electrophotographic photoreceptor having the layer configuration shown in FIG. 1D has a charge generation layer 3 provided on a support 4 and a surface layer of a charge transport material and conductive particles on the support 4. The layer 1 containing at least one and a polyhydroxymethylbisphenol monomer, a polyhydroxymethylbisphenol oligomer, a polyhydroxymethyltrisphenol monomer, and a polymer obtained by polymerizing the polyhydroxymethyltrisphenol oligomer is directly provided.

In addition, regardless of the layer configuration, at least one of a charge transporting substance and conductive particles, a polyhydroxymethylbisphenol monomer, a polyhydroxymethylbisphenol oligomer, and a polyhydroxymethyltrisphenol are provided on the surface layer of the electrophotographic photosensitive member. A monomer and a polymer obtained by polymerizing a polyhydroxymethyltrisphenol oligomer may be contained.

支持 The support of the electrophotographic photoreceptor of the present invention only needs to have conductivity, and for example, a support made of a metal such as aluminum, an aluminum alloy, and stainless steel can be used. Alternatively, the above-described metal support or plastic support having a layer formed by coating a film of aluminum, an aluminum alloy, an indium oxide-tin oxide alloy, or the like by vacuum evaporation can be used. In addition, a support in which conductive particles such as carbon black, tin oxide particles, titanium oxide particles, and silver particles are impregnated with plastic or paper together with a suitable binder resin, or a plastic containing a conductive binder resin is used. You can also.

と お り As described above, a conductive layer may be provided on the support for the purpose of preventing interference fringes due to scattering of laser light or the like, and covering the support for scratches. The conductive layer can be formed by dispersing conductive particles such as carbon black and metal particles in a binder resin. The thickness of the conductive layer is preferably 5 to 40 μm, and more preferably 10 to 30 μm.

As described above, an intermediate layer having a barrier function or an adhesive function may be provided between the support or the conductive layer and the photosensitive layer (charge generation layer, charge transport layer). The intermediate layer is formed for the purpose of improving the adhesiveness of the photosensitive layer, improving the coating property, improving the charge injection property from the support, protecting the photosensitive layer against electrical breakdown, and the like. The intermediate layer can be formed using materials such as casein, polyvinyl alcohol, ethyl cellulose, ethylene-acrylic acid copolymer, polyamide, modified polyamide, polyurethane, gelatin, and aluminum oxide. The thickness of the intermediate layer is preferably 5 μm or less, and more preferably 0.1 to 3 μm.

As the charge generating substance used in the electrophotographic photoreceptor of the present invention, for example, azo pigments such as monoazo, disazo, and trisazo, metal phthalocyanine, phthalocyanine pigments such as nonmetal phthalocyanine, indigo, indigo pigments such as thioindigo, Perylene anhydrides, perylene pigments such as perylene imide, and polycyclic quinone pigments such as anthraquinone and pyrenequinone, squarylium dyes, pyrylium salts and thiapyrylium salts, triphenylmethane dyes, selenium, selenium-tellurium, amorphous Examples include inorganic substances such as silicon, quinacridone pigments, azulhenium salt pigments, cyanine dyes, xanthene dyes, quinone imine dyes, styryl dyes, cadmium sulfide, and zinc oxide.

When the photosensitive layer is a laminated photosensitive layer, as the binder resin used for the charge generation layer, for example, polycarbonate resin, polyester resin, polyarylate resin, butyral resin, polystyrene resin, polyvinyl acetal resin, diallyl phthalate resin, acrylic resin, Examples include methacrylic resin, vinyl acetate resin, phenolic resin, silicone resin, polysulfone resin, styrene-butadiene copolymer resin, alkyd resin, epoxy resin, urea resin, and vinyl chloride-vinyl acetate copolymer resin. These can be used alone, as a mixture or as a copolymer, alone or in combination of two or more.

The solvent used for the coating solution for the charge generation layer is selected from the solubility and dispersion stability of the binder resin and the charge generation material to be used. Examples of the organic solvent include alcohols, sulfoxides, ketones, ethers, esters, and aliphatic halogens. Hydrocarbons and aromatic compounds.

The charge generation layer can be formed by applying and drying a charge generation layer coating solution obtained by dispersing a charge generation substance together with a binder resin and a solvent. Examples of the dispersion method include a method using a homogenizer, an ultrasonic wave, a ball mill, a sand mill, an attritor, a roll mill, and the like. The ratio between the charge generating substance and the binder resin is preferably in the range of 1: 0.3 to 1: 4. The thickness of the charge generation layer is preferably 5 μm or less, and more preferably 0.01 to 1 μm.

電荷 In addition, various sensitizers, antioxidants, ultraviolet absorbers, plasticizers, and the like can be added to the charge generation layer as needed.

電荷 Examples of the charge transporting substance used in the electrophotographic photoreceptor of the present invention include a triarylamine compound, a hydrazone compound, a styryl compound, a stilbene compound, a pyrazoline compound, an oxazole compound, a thiazole compound, and a triarylmethane compound.

For example, as the binder resin used for the charge transport layer other than the surface layer of the electrophotographic photosensitive member, such as the charge transport layer 2 in FIGS. 1A, 1B and 1C, for example, an acrylic resin Styrene resin, polyester, polycarbonate resin, polyarylate, polysulfone, polyphenylene oxide, epoxy resin, polyurethane resin, alkyd resin, unsaturated resin and the like. In particular, polymethyl methacrylate, polystyrene, styrene-acrylonitrile copolymer, polycarbonate resin, polyarylate resin, and diallyl phthalate resin are preferred.

The charge transport layer can be formed by applying a charge transport layer coating solution obtained by dissolving a charge transport material and a binder resin in a solvent, and drying. The ratio between the charge transport material and the binder resin is preferably in the range of 2: 1 to 1: 2 (mass ratio). As the solvent, ketones such as acetone and methyl ethyl ketone, esters such as methyl acetate and ethyl acetate, aromatic hydrocarbons such as toluene and xylene, and hydrocarbons substituted with halogen atoms such as chlorobenzene, chloroform and carbon tetrachloride are used. Can be When applying the coating solution for the charge transport layer, for example, an application method such as a dip coating method, a spray coating method, and a spinner coating method can be used. When drying after coating, the drying temperature is preferably in the range of 10 ° C to 200 ° C, and particularly preferably in the range of 20 ° C to 150 ° C. The drying time is preferably in the range of 5 minutes to 5 hours, and particularly preferably in the range of 10 minutes to 2 hours. Drying may be air drying or static drying.

(4) The thickness of the charge transport layer which is not the surface layer of the electrophotographic photosensitive member is preferably 5 to 40 μm, and more preferably 7 to 30 μm.

Further, an antioxidant, an ultraviolet absorber, a plasticizer, and the like can be added to the charge transport layer as needed.

As described above, the surface layer of the electrophotographic photosensitive member provided on the photosensitive layer (for example, on the charge transporting layer) or the surface layer of the electrophotographic photosensitive member provided directly on the charge generating layer includes a polyhydroxymethylbisphenol monomer, It contains a polyhydroxymethylbisphenol oligomer, a polyhydroxymethyltrisphenol monomer, and a polymer obtained by polymerizing a polyhydroxymethyltrisphenol oligomer.

The content of the polymer obtained by polymerizing the polyhydroxymethylbisphenol monomer, the polyhydroxymethylbisphenol oligomer, the polyhydroxymethyltrisphenol monomer, and the polyhydroxymethyltrisphenol oligomer in the surface layer of the electrophotographic photoreceptor is the total weight of the surface layer. Is preferably 10 to 80% by mass, and more preferably 30 to 60% by mass.

The polyhydroxymethylbisphenol monomer, polyhydroxymethylbisphenol oligomer, polyhydroxymethyltrisphenol monomer, and polyhydroxymethyltrisphenol oligomer used in the present invention are subjected to a heat treatment to form an ether bond by a condensation reaction between hydroxymethyl groups. Alternatively, a further condensation reaction proceeds to form a methylene bond, or a methylene bond is formed by a condensation reaction between a hydrogen atom at the ortho or para position of the hydroxy group in the hydroxyphenyl group and the hydroxymethyl group, When these condensation reactions occur between various molecules, a three-dimensional cured film having a high crosslinking density can be obtained. These condensation reactions are reactions that are not hindered by moisture or oxygen in the air and sufficiently proceed even in a system to which a charge transport substance is added.

Further, the polyhydroxymethylbisphenol monomer, polyhydroxymethylbisphenol oligomer, polyhydroxymethyltrisphenol monomer, and the crosslinking reaction by heat treatment of the polyhydroxymethyltrisphenol oligomer used in the present invention include a step of curing the thermosetting resin. It has the feature that it is not necessary to add a curing catalyst generally used. Therefore, if a polyhydroxymethylbisphenol monomer, a polyhydroxymethylbisphenol oligomer, a polyhydroxymethyltrisphenol monomer, or a polyhydroxymethyltrisphenol oligomer is used for the surface layer of an electrophotographic photoreceptor, an increase in residual potential due to a residual curing catalyst or There is no problem such as a decrease in resistance of the surface layer.

In addition, the polyhydroxymethylbisphenol monomer, polyhydroxymethylbisphenol oligomer, polyhydroxymethyltrisphenol monomer, and polyhydroxymethyltrisphenol oligomer used in the present invention do not require the addition of a curing catalyst, or areocyanate or silicone resin. In contrast, since the hydroxymethyl group is sufficiently stable to moisture, the stability of the coating solution for the surface layer of the electrophotographic photosensitive member is also excellent.

The polyhydroxymethylbisphenol monomer used in the present invention may be a single bond, a carbonyl group, an ether group, a thioether group, or a —CR ⁰¹ R ⁰² — group (R ⁰¹ and R ⁰² are each independently a hydrogen atom, a substituted or Represents an unsubstituted alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted phenyl group, or a substituted or unsubstituted 3 to 3 carbon atoms formed by combining R ⁰¹ and R ^02. 6 represents a cycloalkylidene group, provided that both R ⁰¹ and R ⁰² are not substituted or unsubstituted phenyl groups.) And particularly, polyhydroxymethylbispheno having a structure represented by the following formula (1): And more preferably from Rumonoma.

(In the formula (1), X ¹¹ is a single bond, a carbonyl group, an ether group, a thioether group, or a —CR ⁰¹ R ⁰² — group (R ⁰¹ and R ⁰² are each independently a hydrogen atom, a substituted or unsubstituted group. A substituted or unsubstituted alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted phenyl group; or a substituted or unsubstituted 3 to 6 carbon atoms formed by combining R ⁰¹ and R ^02. Wherein both R ⁰¹ and R ⁰² are not substituted or unsubstituted phenyl groups.) R ^{11 to} R ¹⁴ each independently represent a hydroxymethyl group, hydrogen An atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms other than a hydroxymethyl group, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, Others, a substituted or unsubstituted alkoxy group having 1 to 4 carbon atoms. ^However, at least two R 11 ^{to R 14} is a hydroxymethyl group.)
Further, the polyhydroxymethylbisphenol oligomer used in the present invention may be a single bond, a carbonyl group, an ether group, a thioether group, or a —CR ⁰¹ R ⁰² — group (R ⁰¹ and R ⁰² are each independently a hydrogen atom, Represents a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted phenyl group, or a substituted or unsubstituted carbon atom formed by combining R ⁰¹ and R ⁰² 3 to 6 cycloalkylidene groups, provided that both R ⁰¹ and R ⁰² are not substituted or unsubstituted phenyl groups). It is preferably a polyhydroxymethylbisphenol oligomer having a condensed structure, and particularly, a compound represented by the following formula (2) And more preferably in bisphenol monomer having a structure represented is a poly hydroxymethyl bisphenol oligomer having a condensed structure via a methylene group.

(In the formula (2), X ²¹ is a single bond, a carbonyl group, an ether group, a thioether group, or a —CR ⁰¹ R ⁰² — group (R ⁰¹ and R ⁰² are each independently a hydrogen atom, a substituted or unsubstituted group. A substituted or unsubstituted alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted phenyl group; or a substituted or unsubstituted 3 to 6 carbon atoms formed by combining R ⁰¹ and R ^02. Wherein both R ⁰¹ and R ⁰² are not substituted or unsubstituted phenyl groups.) R ^{21 to} R ²⁴ each independently represent a hydrogen atom or a halogen atom A substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, or a substituted or unsubstituted 1 to 4 carbon atom An alkoxy group.)
Further, when X ¹¹ in the above formula (1) or X ²¹ in the above formula (2) is a divalent group having 3 or more carbon atoms, the solubility of polyhydroxymethylbisphenol monomer and polyhydroxymethylbisphenol oligomer Is improved, and a coating solution having higher productivity can be prepared.

Furthermore, X ¹¹ in the formula (1) X ¹¹ or the equation in (2) is, if the divalent group having 5 or more carbon atoms having a cyclic structure, polyhydroxy methyl bisphenol monomers, polyhydroxy methyl bisphenol It is preferable because the strength of the surface layer of the electrophotographic photoreceptor containing the polyhydroxymethylbisphenol monomer and the polymer of the polyhydroxymethylbisphenol oligomer is further improved as well as the solubility of the oligomer is improved.

When a charge transporting substance is contained in the surface layer of the electrophotographic photoreceptor, when X ¹¹ in the above formula (1) or X ²¹ in the above formula (2) is a divalent group having a benzene ring, The compatibility between the polyhydroxymethylbisphenol monomer and the polyhydroxymethylbisphenol oligomer and the charge transport material is improved, and the electron polarization is increased due to the increase in the number of aromatic units. It is preferable because it is further improved.

Further, when X ¹¹ in the above formula (1) or X ²¹ in the above formula (2) is an ether group, a thioether group, or a di (trifluoromethyl) methylene group, It is preferable because the strength of the surface layer of the electrophotographic photosensitive member containing a polymer of a polyhydroxymethylbisphenol monomer and a polyhydroxymethylbisphenol oligomer is further improved.

ポ リ Further, the polyhydroxymethyl trisphenol monomer used in the present invention is preferably a polyhydroxymethyl trisphenol monomer having a structure represented by the following formula (3).

(In the formula (3), Q ^{31 to} Q ³⁶ each independently represent a hydroxymethyl group, a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms other than a hydroxymethyl group, It represents an unsubstituted alkenyl group having 1 to 4 carbon atoms or a substituted or unsubstituted alkoxy group having 1 to 4 carbon atoms, provided that at least two of Q ^{31 to} Q ³⁶ are hydroxymethyl groups. Y ³¹ is a trivalent group having a structure represented by the following formula (31), a trivalent group having a structure represented by the following formula (32), or a trivalent group having a structure represented by the following formula (33) It is.

(In the formula (31), X ^{311 to} X ³¹³ each independently represent a single bond, a carbonyl group, an ether group, a thioether group, or a —CR ⁰¹ R ⁰² — group (R ⁰¹ and R ⁰² each independently represent , A hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms.) Q ^{311 to} Q ³¹³ each independently represent a hydrogen atom or a substituted or unsubstituted carbon atom. It represents an alkyl group of Formulas 1 to 4.)

(In Formula (32), Q ³²¹ represents a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms.)

(In the formula (33), X ³³¹ is a single bond, a carbonyl group, an ether group, a thioether group, or a —CR ⁰¹ R ⁰² — group (R ⁰¹ and R ⁰² are each independently a hydrogen atom or a substituted Q ³³¹ represents a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms.))
Further, the polyhydroxymethyl trisphenol oligomer used in the present invention may be a polyhydroxymethyl trisphenol oligomer having a structure in which a trisphenol monomer having a structure represented by the following formula (4) is condensed via a methylene group. preferable.

(In the formula (4), Q ^{41 to} Q ⁴⁶ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted carbon atom having 1 to 4 carbon atoms. Or a substituted or unsubstituted alkoxy group having 1 to 4 carbon atoms, Y ⁴¹ is a trivalent group having a structure represented by the following formula (41), and represented by the following formula (42) A trivalent group having a structure or a trivalent group having a structure represented by the following formula (43).

(In Formula (41), X ^{411 to} X ⁴¹³ each independently represent a single bond, a carbonyl group, an ether group, a thioether group, or a —CR ⁰¹ R ⁰² — group (R ⁰¹ and R ⁰² each independently represent , A hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms.) Q ^{411 to} Q ⁴¹³ each independently represent a hydrogen atom or a substituted or unsubstituted carbon atom. It represents an alkyl group of Formulas 1 to 4.)

(In Formula (42), Q ⁴²¹ represents a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms.)

(In the formula (43), X ⁴³¹ is a single bond, a carbonyl group, an ether group, a thioether group, or a —CR ⁰¹ R ⁰² — group (R ⁰¹ and R ⁰² are each independently a hydrogen atom or a substituted And Q ⁴³¹ represents a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms.))
In addition, at least one of X ^{311 to} X ^{313 in} the above formula (31), X ³³¹ in the above formula (33), or at least one of X ^{411 to} X ^{413 in} the above formula (41) is Alternatively, when X ⁴³¹ in the above formula (43) is a divalent group having 3 or more carbon atoms, the solubility of the polyhydroxymethyl trisphenol monomer and the polyhydroxymethyl trisphenol oligomer is improved, and the productivity is further improved. It is possible to prepare a coating solution having excellent water resistance, which is preferable.

In addition, at least one of X ^{311 to} X ^{313 in} the above formula (31), X ³³¹ in the above formula (33), or at least one of X ^{411 to} X ^{413 in} the above formula (41) is Alternatively, when X ⁴³¹ in the above formula (43) is an ether group or a thioether group, a polymer of a polyhydroxymethyl trisphenol monomer or a polyhydroxymethyl trisphenol oligomer is formed by a hetero atom possessed by these groups. It is preferable because the strength of the surface layer of the electrophotographic photosensitive member to be contained is further improved.

When a charge transport material is contained in the surface layer of the electrophotographic photoreceptor, Y ³¹ in the above formula (3) is a trivalent group having a structure represented by the above formula (31), or If Y ^{41 in} (4) is a trivalent group having a structure represented by the above formula (41), the compatibility between the polyhydroxymethyltrisphenol monomer, the polyhydroxymethyltrisphenol oligomer and the charge transport material is improved. It is preferable that the electron transporting ability in the surface layer of the electrophotographic photosensitive member is further improved due to the increase in the electron polarization due to the increase in the aromatic units.

Hereinafter, the polyhydroxymethylbisphenol monomer used in the present invention and the bisphenol monomer (bisphenol monomer having two to three benzene rings) used in obtaining the polyhydroxymethylbisphenol oligomer used in the present invention by condensation are described. Specific examples are summarized below.

In the following formulas (B-1) to (B-55), R ^{B1 to} R ^B4 each independently represent a hydroxymethyl group or a hydrogen atom.

Also, in the case of poly hydroxymethyl bisphenol ^monomer, 2-4 R B1 ^{to R B4} is a hydroxymethyl group. In the case of one of the following formulas (B-1) to (B-55) in which at least one of R ^{B1 to} R ^B4 is missing, two to three of those not missing are hydroxymethyl groups. It is.

Also, in the case of bisphenol monomer used in obtaining the condensation polyhydroxy methyl bisphenol oligomer, R ^B1 to R ^B4 may be either an hydroxymethyl group be a hydrogen atom, but the bisphenol monomer are condensed As described above, the polyhydroxymethylbisphenol oligomer having a structure must have 2 to 4 hydroxymethyl groups.

ポ リ The polyhydroxymethylbisphenol monomer and the polyhydroxymethylbisphenol oligomer used in the present invention are disclosed, for example, in JP-A-6-28067 and JP-A-6-321947.

Next, the polyhydroxymethyl trisphenol monomer used in the present invention and the trisphenol monomer used in obtaining the polyhydroxymethyl trisphenol oligomer used in the present invention by condensation (trisphenol having 2 to 3 benzene rings) Specific examples of (phenol monomer) are shown below.

In the following formulas (T-1) to (T-25), R ^{T1 to} R ^T6 each independently represent a hydroxymethyl group or a hydrogen atom.

In the case of polyhydroxymethyl trisphenol monomer, 2 to ⁶ of R ^{T1 to} R ^T6 are hydroxymethyl groups. In the case of one of the following formulas (T-1) to (T-25) in which at least one of R ^{T1 to} R ^T6 is missing, two to five of the non-missing ones have a hydroxymethyl group. It is.

In the case of a trisphenol monomer used for obtaining a polyhydroxymethyltrisphenol oligomer by condensation, any of R ^{T1 to} R ^T6 may be a hydrogen atom or a hydroxymethyl group. As described above, it is essential that the polyhydroxymethyl trisphenol oligomer having a condensed structure has 2 to 6 hydroxymethyl groups.

The polyhydroxymethylbisphenol monomer, polyhydroxymethylbisphenol oligomer, polyhydroxymethyltrisphenol monomer, and polyhydroxymethyltrisphenol oligomer used in the present invention are, for example, bisphenols having a structure in which all of the hydroxymethyl groups contained therein are replaced by hydrogen atoms. It can be synthesized by subjecting a monomer or trisphenol monomer as a starting material to a condensation reaction with an aldehyde under alkaline conditions (hereinafter also referred to as hydroxymethylation reaction). In this condensation reaction, depending on the ratio of the starting material bisphenol monomer or trisphenol monomer to aldehyde, the alkaline conditions in the reaction system, the reaction temperature, the concentration, etc., the bisphenol monomer, bisphenol oligomer or trisphenol monomer, trisphenol It is possible to adjust the number of hydroxymethyl groups bonded per oligomer.

As described above, the polyhydroxymethylbisphenol monomer, polyhydroxymethylbisphenol oligomer, polyhydroxymethyltrisphenol monomer, and polyhydroxymethyltrisphenol oligomer used in the present invention may have two or more hydroxymethyl groups per one. This is essential, and it is particularly preferable that the number of hydroxymethyl groups is three or more. Polymers of polyhydroxymethylbisphenol monomer, polyhydroxymethylbisphenol oligomer, polyhydroxymethyltrisphenol monomer, and polyhydroxymethyltrisphenol oligomer having only one hydroxymethyl group do not have a three-dimensional cross-linked structure, This is because a high hardness cannot be obtained.

In addition, polyhydroxymethyl bisphenol monomer, polyhydroxymethyl bisphenol oligomer, polyhydroxymethyl trisphenol oligomer having a higher molecular weight than polyhydroxymethyl trisphenol monomer is likely to be varnish-like, so that the film formability is significantly improved, The crosslink density can be easily increased, and a high-strength film can be easily obtained.

Polyhydroxymethylbisphenol oligomer, bisphenol unit of polyhydroxymethyltrisphenol oligomer, trisphenol unit (for example, a unit derived from a bisphenol monomer having a structure represented by the above formula (2), having a structure represented by the above formula (4) The number of units derived from a trisphenol phenol monomer) is preferably 2 to 5.

A method for synthesizing a bisphenol oligomer or a trisphenol oligomer having a structure in which a bisphenol monomer having a structure represented by the above formula (2) or a trisphenol monomer having a structure represented by the above formula (4) is condensed via a methylene group ( A method for oligomerizing a bisphenol monomer having a structure represented by the above formula (2) or a trisphenol monomer having a structure represented by the above formula (4) via a methylene group: hereinafter also referred to as oligomerization reaction) For example, a method of condensing formaldehyde with a bisphenol monomer having a structure represented by the above formula (2) or a trisphenol monomer having a structure represented by the above formula (4) under acidic conditions can be mentioned.

Further, in the course of the above-mentioned hydroxymethylation reaction, the condensation reaction between the hydroxymethyl group at the site already hydroxymethylated and the hydrogen atom at the site not yet hydroxymethylated proceeds, that is, By allowing the methylation reaction and the oligomerization reaction to proceed together, the bisphenol monomer having the structure represented by the above formula (2) or the trisphenol monomer having the structure represented by the above formula (4) is condensed via a methylene group. A bisphenol oligomer or trisphenol oligomer having a structure and having two or more hydroxymethyl groups can also be synthesized.

上 記 The above polyhydroxymethylbisphenol monomer, polyhydroxymethylbisphenol oligomer, polyhydroxymethyltrisphenol monomer, and polyhydroxymethyltrisphenol oligomer to be contained in the surface layer of the electrophotographic photoreceptor of the present invention do not have charge transport ability. Therefore, the surface layer of the electrophotographic photoreceptor needs to contain a charge transporting substance or conductive particles in order to transfer the electric charge without interruption.

First, the charge transport material contained in the surface layer of the electrophotographic photosensitive member will be described.

(4) The content of the charge transporting substance in the surface layer of the electrophotographic photosensitive member is preferably from 20 to 80% by mass, and more preferably from 30 to 60% by mass, based on the total mass of the surface layer. Moreover, 20 to 200 mass% is preferable with respect to the polymer of the polyhydroxymethylbisphenol monomer, the polyhydroxymethylbisphenol oligomer, the polyhydroxymethyltrisphenol monomer, and the polyhydroxymethyltrisphenol oligomer contained in the surface layer. 50-150 mass% is more preferable.

Also, considering the compatibility of the charge transport material with a polyhydroxymethylbisphenol monomer, a polyhydroxymethylbisphenol oligomer, a polyhydroxymethyltrisphenol monomer, and a polyhydroxymethyltrisphenol oligomer, the charge transport material has a hydroxy group. It is preferably a charge transporting substance, and more preferably a charge transporting substance having a hydroxyalkyl group, a hydroxyalkoxy group or a hydroxyphenyl group.

When the charge transport material has a hydroxyalkyl group or a hydroxyalkoxy group, the solubility of the charge transport material in a solvent can be improved, so that the charge transport ability in the surface layer of the electrophotographic photosensitive member is maintained at a high level. It is possible to do. The number of carbon atoms in the alkyl chain of these hydroxyalkyl groups and hydroxyalkoxy groups is preferably from 1 to 8, and particularly preferably from 3 to 5, from the viewpoint of operability and solubility in synthesizing these charge transport materials. Is more preferable.

When the charge transporting substance has a hydroxyphenyl group, a polymerization reaction (condensation reaction / crosslinking reaction) of polyhydroxymethylbisphenol monomer, polyhydroxymethylbisphenol oligomer, polyhydroxymethyltrisphenol monomer, or polyhydroxymethyltrisphenol oligomer In the process, a cross-linking reaction takes place between the charge transporting substance and the polyhydroxymethylbisphenol monomer, polyhydroxymethylbisphenol oligomer, polyhydroxymethyltrisphenol monomer, polyhydroxymethyltrisphenol oligomer, and the resulting electrophotographic photoreceptor The strength of the surface layer is further improved.

Further, as the charge transporting substance contained in the surface layer of the electrophotographic photoreceptor of the present invention, a charge transporting substance having a triarylamine structure (triarylamine compound) is preferable, and a charge transporting substance having a triphenylamine structure is particularly preferable. Substances (triphenylamine compounds) are more preferred.

具体 Specific examples of the charge transport material having a hydroxy group are shown below.

Next, the conductive particles contained in the surface layer of the electrophotographic photosensitive member will be described.

含有 The content of the conductive particles in the surface layer of the electrophotographic photoreceptor is preferably from 20 to 70% by mass, more preferably from 30 to 60% by mass, based on the total mass of the surface layer. Further, it is preferably 10 to 60% by mass based on the polymer of the polyhydroxymethylbisphenol monomer, the polyhydroxymethylbisphenol oligomer, the polyhydroxymethyltrisphenol monomer, and the polyhydroxymethyltrisphenol oligomer contained in the surface layer. 20-50 mass% is more preferable.

Examples of the conductive particles include metal particles, metal oxide particles, conductive polymer particles, and carbon black. Examples of the metal include aluminum, zinc, copper, chromium, nickel, stainless steel, silver, and the like, and those obtained by vapor-depositing these metals on the surfaces of plastic particles. Metal oxides include zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin-doped indium oxide, tantalum-doped tin oxide, tungsten-doped tin oxide, and antimony-doped oxide Tin and zirconium oxide. Examples of the conductive polymer include polyacetylene, polythiophene, and polypyrrole.

Among these conductive particles, zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin-doped indium oxide, tantalum-doped tin oxide, tungsten-doped tin oxide, antimony Is preferred.

These conductive particles may be used alone or in combination of two or more. When two or more kinds are used in combination, they may be used simply by mixing, or may be used in the form of a solid solution or fusion.

The average particle size of the conductive particles used in the present invention is preferably 0.3 μm or less, and more preferably 0.1 μm or less, from the viewpoint of preventing light scattering. Further, a metal oxide is more preferable in terms of transparency.

If the surface layer itself of the electrophotographic photosensitive member does not have a certain degree of conductivity, an electrophotographic photosensitive member satisfying the electrophotographic characteristics cannot be obtained. It is necessary to contain at least one of the conductive particles.

In the present invention, the volume resistivity of the surface layer of the electrophotographic photoreceptor is preferably from 10 ¹⁰ to 10 ¹⁵ Ω · cm, and particularly preferably from 10 ¹¹ to 10 ¹⁴ Ω · cm. If the volume resistivity is less than 10 ¹⁰ Ω · cm, it becomes difficult to hold electric charges, and image deletion may occur. On the other hand, when the volume resistivity exceeds 10 ¹⁵ Ω · cm, the electric charge is difficult to move, and a low concentration and a negative ghost may occur.

Volume resistivity can be measured as follows.

First, a layer corresponding to the surface layer of an electrophotographic photoreceptor having a thickness T = 3 [μm] is formed on a comb-shaped platinum electrode having an interelectrode distance D = 180 [μm] and a length L = 5.9 [cm]. Is provided. Next, a current value I [A] when a DC voltage V = 100 [V] is applied between the comb-shaped electrodes is measured by a pA meter (picoampere meter), and the volume resistivity ρv [Ω · cm] is calculated by the following equation. ] Is obtained.

ρv = (V / I) × (T × L / D)
The conductive particles are preferably used after being surface-treated. Examples of the surface treatment agent that can be used in this surface treatment include a silane coupling agent, a silicone oil, a siloxane compound, and a surfactant. From the viewpoint of the dispersibility and dispersion stability of the conductive particles, it is particularly effective to use a fluorine atom-containing surface treatment agent.

具体 Specific examples of the fluorine atom-containing silane coupling agent are shown below.

具体 Specific examples of the fluorine-containing silicone oil are shown below.

具体 Specific examples of the fluorine atom-containing surfactant are shown below.

The doped tin oxide particles are particularly preferable as the conductive particles, and the surface treatment method is as follows.

First, tin oxide particles and a surface treating agent are mixed and dispersed in a suitable solvent, and the surface treating agent is attached to the surface of the tin oxide particles. As a dispersing means, a dispersing means such as a ball mill or a sand mill is used. Next, the solvent may be removed from the dispersion solution, and the surface treatment agent may be fixed to the surface of the tin oxide particles. If necessary, a heat treatment may be further performed thereafter. Further, a catalyst for promoting the reaction may be added to the treatment liquid. Further, if necessary, the tin oxide particles after the surface treatment may be further pulverized. The ratio of the surface treating agent depends on the particle size of the tin oxide particles, but is preferably from 1 to 65% by mass, and more preferably from 5 to 50% by mass, based on the total mass of the tin oxide.

In addition, resin particles such as fluorine atom-containing resin particles such as polytetrafluoroethylene resin particles and silicone resin particles may be added to the surface layer of the electrophotographic photoreceptor of the present invention.

Examples of the solvent for preparing the coating solution for the surface layer of the electrophotographic photoreceptor of the present invention include polyhydroxymethylbisphenol monomer, polyhydroxymethylbisphenol oligomer, polyhydroxymethyltrisphenol monomer, polyhydroxymethyltrisphenol oligomer and a charge transport material. Preferred are solvents that dissolve sufficiently and do not adversely affect the lower layers (such as the charge transport layer and the charge generation layer) that come into contact with the coating solution of the surface layer.

Therefore, as a solvent for preparing the coating solution for the surface layer, alcohols such as methanol, ethanol, and 2-propanol; ketones such as acetone, cyclohexanone, and methyl ethyl ketone; esters such as methyl acetate and ethyl acetate; tetrahydrofuran and dioxane; Preferred are ethers, aromatic hydrocarbons such as toluene and xylene, and hydrocarbons substituted with halogen atoms such as chlorobenzene and dichloromethane. Among them, alcohols such as methanol, ethanol and 2-propanol are more preferable. Further, a mixture of plural kinds of solvents may be used.

Since a general charge transporting substance is insoluble or hardly soluble in an alcohol solvent, a polyhydroxymethylbisphenol monomer, a polyhydroxymethylbisphenol oligomer, a polyhydroxymethyltrisphenol monomer, a polyhydroxymethyl It is difficult to uniformly dissolve the trisphenol oligomer and the charge transporting substance. Therefore, if a charge transporting substance having a hydroxy group as described above is used as the charge transporting substance, since it is soluble in an alcohol solvent, Even when an alcohol solvent having little effect on the lower layer such as the charge transport layer is used, polyhydroxymethyl bisphenol monomer, polyhydroxymethyl bisphenol oligomer, polyhydroxymethyl trisphenol monomer, Carboxymethyl becomes easy to methyl trisphenol oligomer uniformly dissolved and a charge transporting substance.

When applying the coating solution for the surface layer of the electrophotographic photoreceptor of the present invention, a coating method such as a dip coating method, a spray coating method, a spinner coating method, a roller coating method, a Meyer bar coating method, or a blade coating method is used. be able to.

に お い て In the present invention, by performing a heat treatment, a curing reaction of a rehydroxymethylbisphenol monomer, a polyhydroxymethylbisphenol oligomer, a polyhydroxymethyltrisphenol monomer, and a polyhydroxymethyltrisphenol oligomer can be performed. This heat treatment may be performed together with the drying step of the solvent of the coating solution for the surface layer after the application of the surface layer.

Curing reaction conditions by heat treatment can be appropriately adjusted depending on factors such as desired surface layer hardness, surface layer thickness, monomer reactivity, and thermal degradation of the photosensitive layer itself. The temperature is preferably 180 ° C, more preferably 120 to 165 ° C. The heating time is preferably from 10 to 120 minutes, particularly preferably from 20 to 90 minutes, and even more preferably from 30 to 70 minutes. Further, a stepwise heating / cooling step may be provided for the heating temperature.

In the surface layer of the electrophotographic photoreceptor of the present invention, an additive of an antioxidant is added for the purpose of preventing deterioration of the surface layer due to attachment of an active substance such as ozone or nitrogen oxide generated during charging. Is also good.

The thickness of the surface layer of the electrophotographic photoreceptor of the present invention also depends on the layer structure of the electrophotographic photoreceptor, but if it is too thin, the durability of the electrophotographic photoreceptor is impaired. Because of this, the residual potential increases, so it is necessary to make the thickness appropriate. Specifically, a polyhydroxymethylbisphenol monomer, a polyhydroxymethylbisphenol oligomer, and a polyhydroxymethyltrisphenol are formed on the photosensitive layer (the charge transport layer 2 in (a), (b) and (c) of FIG. 1). When the layer 1 containing the monomer and the polymer of the polyhydroxymethyltrisphenol oligomer and the charge transport material is separately provided, the thickness is preferably 0.1 μm to 10 μm, and more preferably 0.5 μm to 7 μm. preferable. On the other hand, as shown in FIG. 1D, a polymer of a polyhydroxymethylbisphenol monomer, a polyhydroxymethylbisphenol oligomer, a polyhydroxymethyltrisphenol monomer, a polyhydroxymethyltrisphenol oligomer and a charge transport material are formed on the charge generation layer 3. When the layer 1 containing is contained, the thickness is preferably 3 μm to 40 μm, and more preferably 8 μm to 20 μm.

FIG. 2 shows a schematic configuration of an electrophotographic apparatus provided with a process cartridge having the electrophotographic photosensitive member of the present invention.

In FIG. 2, reference numeral 11 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is driven to rotate around an axis 12 at a predetermined peripheral speed in a direction indicated by an arrow. The electrophotographic photoreceptor 11 receives a uniform charge of a predetermined positive or negative potential on the peripheral surface thereof by a charging means (primary charging means) 13 during the rotation process, and then exposes the light to an exposure means such as slit exposure or laser beam scanning exposure. It receives exposure light (image exposure light) 14 output from a (not shown). In this way, an electrostatic latent image corresponding to the target image information is sequentially formed on the peripheral surface of the electrophotographic photosensitive member 11.

The formed electrostatic latent image is then developed with toner by a developing unit 15 and taken out from a paper feeding unit (not shown) between the electrophotographic photoconductor 11 and the transfer unit 16 in synchronization with the rotation of the electrophotographic photoconductor 11. The toner images formed and carried on the peripheral surface of the electrophotographic photoreceptor 11 are sequentially transferred by a transfer unit 16 to a transfer material 17 such as paper fed and fed.

The transfer material 17 to which the toner image has been transferred is separated from the peripheral surface of the electrophotographic photoreceptor, introduced into a fixing unit 18 and subjected to image fixing, thereby being printed out of the apparatus as an image formed product (print, copy). Is done.

The peripheral surface of the electrophotographic photoreceptor 11 after the image transfer is cleaned and cleaned by removing the untransferred toner by the cleaning unit 19, and is further subjected to a static elimination process by the pre-exposure light 20 from the pre-exposure unit (not shown). Thereafter, it is repeatedly used for image formation. When the charging unit 13 is a contact charging unit using a charging roller or the like, the pre-exposure is not necessarily required.

In the present invention, among the above-described components such as the electrophotographic photoreceptor 11, the charging unit 13, the developing unit 15, and the cleaning unit 19, a plurality of components are housed in a container and integrally combined as a process cartridge. This process cartridge may be configured to be detachable from a main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. For example, at least one of the charging unit 13, the developing unit 15, and the cleaning unit 19 is integrally supported with the electrophotographic photosensitive member 11 to form a cartridge, and is detachably attached to the apparatus main body by using a guide unit 22 such as a rail of the apparatus main body. Process cartridge 21.

In the case where the electrophotographic apparatus is a copier or a printer, the exposure light 14 is reflected light or transmitted light from the original, or the original is read by a sensor and converted into a signal. Light emitted by scanning, driving of an LED array, driving of a liquid crystal shutter array, or the like.

The electrophotographic photoreceptor of the present invention can be widely used not only for copying machines and laser beam printers but also for electrophotographic applications such as CRT printers, LED printers, faxes, liquid crystal printers, and laser plate making. .

(Example)
Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to these. In the examples, “parts” means “parts by mass”.

(Example 1)
Using an aluminum cylinder (JIS A3003 aluminum alloy) having a length of 260.5 mm and a diameter of 30 mm (JIS A3003 aluminum alloy) as a support, a 5% by mass methanol solution of a polyamide resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) is applied by dip coating. To form an intermediate layer having a thickness of 0.5 μm.

Next, as a charge generating substance, 3 parts of a crystalline form of hydroxygallium phthalocyanine having a strongest peak at 28.1 ° of Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction and polyvinyl butyral resin (trade name: Eslek BX) -1 and 2 parts of Sekisui Chemical Co., Ltd.) and 100 parts of cyclohexanone, dispersed for 1 hour by a sand mill using glass beads having a diameter of 1 mm, and diluted with 100 parts of methyl ethyl ketone. A coating solution was prepared, and the charge generating layer coating solution was dip-coated on the intermediate layer and dried at 90 ° C. for 10 minutes to form a charge generating layer having a thickness of 0.17 μm.

Next, 7.5 parts of a charge transport material having a structure represented by the following formula:

And 10 parts of bisphenol Z-type polycarbonate (trade name: Z-200, manufactured by Mitsubishi Gas Chemical Co., Ltd.) were dissolved in a mixed solvent of 60 parts of monochlorobenzene / 20 parts of dichloromethane. This solution was dip-coated on the charge generation layer and dried with hot air at 110 ° C. for 1 hour to form a charge transport layer having a thickness of 19 μm.

Next, 10 parts of a bisphenol monomer having a structure represented by the above formula (B-3) (all of R ^{B1 to} R ^B4 are hydroxymethyl groups) and a charge transporting material having a structure represented by the above formula (C-12) 7 parts were dissolved in 40 parts of ethyl alcohol (solvent) to prepare a coating solution for a surface layer, dip-coated on the charge transport layer, and dried with hot air at 155 ° C. for 1 hour to form a layer having a thickness of 3 μm ( Surface layer). The measurement of the film thickness was performed using an interference film thickness meter (manufactured by Otsuka Electronics Co., Ltd.). The stability of the coating solution for the surface layer was good. Even when the coating solution was circulated for 24 hours in an environment of a temperature of 23 ° C. and a humidity of 50% RH, no significant change in the liquid property was observed.

The evaluation of the electrophotographic characteristics was performed by using a laser beam printer (trade name: LBP-NX: manufactured by Canon Inc., a contact charging method using a charging roller) configured as shown in FIG. 2, and applying a DC voltage to an AC voltage as an applied voltage. Using a voltage superimposed on the above). The charge was set so that the dark area potential was -700 V, and a laser beam having a wavelength of 780 nm was irradiated to the dark section to measure the amount of light necessary to reduce the -700 V potential to -200 V, and the sensitivity was determined. Further, a potential when a light amount of 20 μJ / cm ² was irradiated was measured as a residual potential Vr. Further, using the same laser beam printer, the shaving amount of 10,000 sheets was measured by the durability test.

(Example 2)
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the charge generation layer was provided as described below.

That is, 4 parts of crystalline oxytitanium phthalocyanine having strong peaks at 9.5 ° and 27.1 ° of Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction and a polyvinyl butyral resin (trade name) : Esrec BX-1, 2 parts by Sekisui Chemical Co., Ltd.) was added to 100 parts of cyclohexanone and dispersed for 4.5 hours by a sand mill using glass beads having a diameter of 1 mm, and 130 parts of ethyl acetate was added thereto. After diluting to prepare a charge generating layer coating solution, the charge generating layer coating solution is dip-coated on the intermediate layer and dried at 90 ° C. for 10 minutes to form a charge generating layer having a thickness of 0.18 μm. Formed.

(Example 3)
In Example 1, a bisphenol monomer having a structure represented by the above formula (B-3) (all of R ^{B1 to} R ^B4 are hydroxymethyl groups) was replaced with a bisphenol monomer having a structure represented by the above formula (B-5) ( except that R ^B1 to R ^B4 is changed to all hydroxymethyl groups) to produce the electrophotographic photosensitive member in the same manner as in example 1 and evaluated.

(Example 4)
In Example 1, a bisphenol monomer having a structure represented by the above formula (B-3) (all of R ^{B1 to} R ^B4 are hydroxymethyl groups) was replaced with a bisphenol monomer having a structure represented by the above formula (B-14) ( except that R ^B1 to R ^B4 is changed to all hydroxymethyl groups) to produce the electrophotographic photosensitive member in the same manner as in example 1 and evaluated.

(Example 5)
In Example 1, a bisphenol monomer having a structure represented by the above formula (B-3) (all of R ^{B1 to} R ^B4 are hydroxymethyl groups) was replaced with a bisphenol monomer having a structure represented by the above formula (B-26) ( except that R ^B1 to R ^B4 is changed to all hydroxymethyl groups) to produce the electrophotographic photosensitive member in the same manner as in example 1 and evaluated.

(Example 6)
In Example 1, a bisphenol monomer having a structure represented by the above formula (B-3) (all of R ^{B1 to} R ^B4 are hydroxymethyl groups) was replaced with a bisphenol monomer having a structure represented by the above formula (B-28) ( except that R ^B1 to R ^B4 is changed to all hydroxymethyl groups) to produce the electrophotographic photosensitive member in the same manner as in example 1 and evaluated.

(Example 7)
In Example 1, the above formula (B-3) a bisphenol monomer having a structure represented ^(R B1 ^{to R B4} are all hydroxymethyl group), a bisphenol monomer having a structure represented by the formula (B-34) ( except that R ^B1 to R ^B4 is changed to all hydroxymethyl groups) to produce the electrophotographic photosensitive member in the same manner as in example 1 and evaluated.

(Example 8)
In Example 1, the above formula (B-3) a bisphenol monomer having a structure represented ^(R B1 ^{to R B4} are all hydroxymethyl group), a bisphenol monomer having a structure represented by the formula (B-35) ( except that R ^B1 to R ^B4 is changed to all hydroxymethyl groups) to produce the electrophotographic photosensitive member in the same manner as in example 1 and evaluated.

(Example 9)
In Example 1, a bisphenol monomer having a structure represented by the above formula (B-3) (all of R ^{B1 to} R ^B4 are hydroxymethyl groups) was replaced with a bisphenol monomer having a structure represented by the above formula (B-50) ( An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1, except that ^RB2 and ^RB3 were all hydroxymethyl groups.

(Example 10)
In Example 1, a bisphenol monomer having a structure represented by the above formula (B-3) (all of R ^{B1 to} R ^B4 are hydroxymethyl groups) was replaced with a bisphenol monomer having a structure represented by the above formula (B-53) ( except that R ^B1 to R ^B4 is changed to all hydroxymethyl groups) to produce the electrophotographic photosensitive member in the same manner as in example 1 and evaluated.

(Example 11)
In Example 1, a bisphenol monomer having a structure represented by the above formula (B-3) (all of R ^{B1 to} R ^B4 are hydroxymethyl groups) was replaced with a bisphenol monomer having a structure represented by the above formula (B-55) ( except that R ^B1 to R ^B4 is changed to all hydroxymethyl groups) to produce the electrophotographic photosensitive member in the same manner as in example 1 and evaluated.

(Examples 12 to 20)
In Example 5, the charge transporting material having the structure represented by the formula (C-12) is replaced by a charge transporting material having the structure represented by the formula (C-4), and the charge transporting material having the structure represented by the formula (C-14). A charge transport material having a structure represented by the formula (C-17); a charge transport material having a structure represented by the formula (C-30); ), A charge transport material having a structure represented by the formula (C-35), a charge transport material having a structure represented by the formula (C-38), and a charge transport material having the structure represented by the formula (C-35). An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 5, except that the charge transport material having the structure represented by the formula (C-55) was changed to the charge transport material having the structure represented by the formula (C-55). did.

(Example 21)
In the same manner as in Example 1, except that the bisphenol monomer having the structure represented by the above formula (B-3) (all of R ^{B1 to} R ^B4 are hydroxymethyl groups) was changed to the following bisphenol oligomer. To prepare an electrophotographic photosensitive member, and evaluated.

That is, a bisphenol oligomer obtained by reacting the above equation (B-3) a bisphenol monomer having a structure represented by (R ^B1 to R ^B4 are all hydrogen atoms) and formaldehyde under alkaline conditions, a methylene group Is a bisphenol oligomer having a structure condensed through a polymer and having two or more hydroxymethyl groups (an average of six). It is varnish-like.

(Examples 22 to 25)
In Example 21, a bisphenol monomer having a structure represented by the above formula (B-3) (all of R ^{B1 to} R ^B4 are hydrogen atoms) was added to a bisphenol monomer having a structure represented by the above formula (B-14), respectively. represented by monomer ^(R B1 ^{to R B4} are all hydrogen atoms), the above equation bisphenol monomer ^(R B1 ^{to R B4} are all hydrogen atoms) having a structure represented by (B-26), the formula (B-28) bisphenol monomer having a structure ^(R B1 ^{to R B4} are all hydrogen atoms), except that bisphenol monomer having a structure represented by the formula ^{(B-34) (R B1} ~R B4 are all hydrogen atoms) was changed to the embodiment An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 21.

(Example 26)
An electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 4 except that the thickness of the surface layer was changed to 1 μm.

(Example 27)
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 4 except that the thickness of the surface layer was changed to 6 μm.

(Example 28)
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 21, except that the surface layer was provided under the following conditions.

That is, in Example 21, a bisphenol monomer having a structure represented by the formula (B-3) (all of R ^{B1 to} R ^B4 are hydrogen atoms) was replaced with a bisphenol monomer having a structure represented by the formula (B-51). (R ^{B2 to} R ^B4 are all hydrogen atoms), and the charge transport material having the structure represented by the formula (C-12) is changed to a charge transport material having a structure represented by the following formula;

Ethyl alcohol was changed to methyl ethyl ketone as a solvent.

(Example 29)
An intermediate layer and a charge generation layer were provided on a support in the same manner as in Example 1.

Next, 10 parts of a bisphenol monomer having a structure represented by the above formula (B-26) (all of R ^{B1 to} R ^B4 are hydroxymethyl groups), and a charge transport material having a structure represented by the above formula (C-12) 7 parts by weight and dissolved in 40 parts of methyl ethyl ketone (solvent) to prepare a coating solution for the surface layer (charge transport layer), dip-coated on the charge generation layer, and dried with hot air at 155 ° C. for 1 hour. A 17 μm surface layer (charge transport layer) was provided.

(Comparative Example 1)
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the surface layer was not provided.

(Comparative Example 2)
In Example 8, a bisphenol monomer having a structure represented by the above formula (B-35) (all of R ^{B1 to} R ^B4 are hydroxymethyl groups) was replaced with a bisphenol monomer having a structure represented by the above formula (B-50) ( An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 8, except that ^RB2 and ^RB3 were all hydrogen atoms.

(Comparative Example 3)
An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the surface layer was provided as described below.

(5) 5 parts of a modified solution of a buret having a structure represented by the following formula (a solid content of 67% by mass);

Also, 7.44 parts of a charge transport material having a structure represented by the above formula (C-50) is dissolved in 50 parts of methyl ethyl ketone to prepare a coating solution for a surface layer, and is spray-coated on the charge transport layer by a spray coating method. It was applied and dried at room temperature for 5 minutes, and then heated and dried at 155 ° C. for 60 minutes to form a surface layer having a thickness of 3 μm. The mixing ratio of the coating solution for the surface layer is such that [the total number of moles of the hydroxy groups of the charge transport material having the structure represented by the above formula (C-50)]: [the total number of moles of the isocyanate groups of the above formula] is 47. : 53.

(Comparative Example 4)
An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 27 except that the surface layer did not contain the charge transporting material having the structure represented by the above formula (C-12).

Table 1 shows the evaluation results of Examples 1 to 29 and Comparative Examples 1 to 4.

Table 1 shows the measured values of the sensitivity and the residual potential of each example and each comparative example, the shaving amount of the surface layer after the durability test of 10,000 sheets, the image quality of the printed image after the durability test, and the coating for the surface layer. The liquid showed stability.

(Example 30)
Using an aluminum cylinder (JIS A3003 aluminum alloy) having a length of 260.5 mm and a diameter of 30 mm (JIS A3003 aluminum alloy) as a support, a 5% by mass methanol solution of a polyamide resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) is applied by dip coating. To form an intermediate layer having a thickness of 0.5 μm.

Next, as a charge generating substance, 3 parts of a crystalline form of hydroxygallium phthalocyanine having a strongest peak at 28.1 ° of Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction and polyvinyl butyral resin (trade name: Eslek BX) -1 and 2 parts of Sekisui Chemical Co., Ltd.) and 100 parts of cyclohexanone, dispersed for 1 hour by a sand mill using glass beads having a diameter of 1 mm, and diluted with 100 parts of methyl ethyl ketone. A coating solution for use was prepared, and the coating solution for a charge generation layer was dip-coated on the intermediate layer, and dried at 90 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.16 μm.

Next, 7.5 parts of a charge transport material having a structure represented by the following formula:

And 10 parts of bisphenol Z-type polycarbonate (trade name: Z-200, manufactured by Mitsubishi Gas Chemical Co., Ltd.) were dissolved in a mixed solvent of 60 parts of monochlorobenzene / 20 parts of dichloromethane. This solution was dip-coated on the charge generation layer and dried with hot air at 110 ° C. for 1 hour to form a charge transport layer having a thickness of 20 μm.

Next, 10 parts of a trisphenol monomer having a structure represented by the above formula (T-2) (RT ^{1 to} R ^T6 are all hydroxymethyl groups) and a charge transport having a structure represented by the above formula (C-12) 7 parts of the substance were dissolved in 40 parts of ethyl alcohol (solvent) to prepare a coating solution for the surface layer, dip-coated on the charge transport layer, and dried with hot air at 155 ° C. for 1 hour to form a 3 μm-thick layer. (Surface layer). The measurement of the film thickness was performed using an interference film thickness meter (manufactured by Otsuka Electronics Co., Ltd.). The stability of the coating solution for the surface layer was good. Even when the coating solution was circulated for 24 hours in an environment of a temperature of 23 ° C. and a humidity of 50% RH, no significant change in the liquid property was observed.

The evaluation of the electrophotographic characteristics was performed by using a laser beam printer (trade name: LBP-NX: manufactured by Canon Inc., a contact charging method using a charging roller) configured as shown in FIG. 2, and applying a DC voltage to an AC voltage as an applied voltage. Using a voltage superimposed on the above). The charge was set so that the dark area potential was -700 V, and a laser beam having a wavelength of 780 nm was irradiated to the dark section to measure the amount of light necessary to reduce the -700 V potential to -200 V, and the sensitivity was determined. Further, a potential when a light amount of 20 μJ / cm ² was irradiated was measured as a residual potential Vr. Further, using the same laser beam printer, the shaving amount due to the durability of 10,000 sheets was measured.

(Example 31)
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 30, except that the charge generation layer was provided as described below.

That is, 4 parts of crystalline oxytitanium phthalocyanine having strong peaks at 9.5 ° and 27.1 ° of Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction and a polyvinyl butyral resin (trade name) : Esrec BX-1, 2 parts by Sekisui Chemical Co., Ltd.) was added to 110 parts of cyclohexanone and dispersed for 4.5 hours by a sand mill using glass beads having a diameter of 1 mm, and 130 parts of ethyl acetate was added thereto. After diluting to prepare a charge generating layer coating solution, the charge generating layer coating solution is dip-coated on the intermediate layer and dried at 90 ° C. for 10 minutes to form a charge generating layer having a thickness of 0.18 μm. Formed.

(Example 32)
In Example 30, a trisphenol monomer having a structure represented by the above formula (T-2) (R ^{T1 to} R ^T6 are all hydroxymethyl groups) was replaced with a trisphenol having a structure represented by the above formula (T-11). except that the monomer (R ^T1 to R ^T6 are all hydroxymethyl group) were changed to, to produce the electrophotographic photosensitive member in the same manner as in example 30, it was evaluated.

(Example 33)
In Example 30, a trisphenol monomer having a structure represented by the formula (T-2) (RT ^{1 to} R ^T6 are all hydroxymethyl groups) was replaced with a trisphenol having a structure represented by the formula (T-12). An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 30, except that the monomers ( ^RT2 , ^RT4 and ^RT6 were all hydroxymethyl groups).

(Example 34)
In Example 30, a trisphenol monomer having a structure represented by the above formula (T-2) (RT ^{1 to} R ^T6 are all hydroxymethyl groups) was replaced with a trisphenol having a structure represented by the above formula (T-13). except that the monomer (R ^T1 to R ^T6 are all hydroxymethyl group) were changed to, to produce the electrophotographic photosensitive member in the same manner as in example 30, it was evaluated.

(Example 35)
In Example 30, a trisphenol monomer having a structure represented by the above formula (T-2) (RT ^{1 to} R ^T6 are all hydroxymethyl groups) was replaced with a trisphenol having a structure represented by the above formula (T-16). except that the monomer (R ^T1 to R ^T6 are all hydroxymethyl group) were changed to, to produce the electrophotographic photosensitive member in the same manner as in example 30, it was evaluated.

(Example 36)
In Example 30, a trisphenol monomer having a structure represented by the above formula (T-2) (RT ^{1 to} R ^T6 were all hydroxymethyl groups) was replaced with a trisphenol having a structure represented by the above formula (T-17). An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 30, except that the monomers ( ^RT2 , ^RT4 and ^RT6 were all hydroxymethyl groups).

(Example 37)
In Example 30, a trisphenol monomer having a structure represented by the above formula (T-2) (RT ^{1 to} R ^T6 are all hydroxymethyl groups) was replaced with a trisphenol having a structure represented by the above formula (T-18). An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 30, except that the monomers ( ^RT2 , ^RT4 and ^RT6 were all hydroxymethyl groups).

(Example 38)
In Example 30, a trisphenol monomer having a structure represented by the above formula (T-2) (RT ^{1 to} R ^T6 are all hydroxymethyl groups) was replaced with a trisphenol having a structure represented by the above formula (T-19). An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 30, except that the monomers ( ^RT2 , ^RT4 and ^RT6 were all hydroxymethyl groups).

(Example 39)
In Example 30, a trisphenol monomer having a structure represented by the above formula (T-2) (RT ^{1 to} R ^T6 are all hydroxymethyl groups) was replaced by a trisphenol having a structure represented by the above formula (T-25). except that the monomer (R ^T1 to R ^T6 are all hydroxymethyl group) were changed to, to produce the electrophotographic photosensitive member in the same manner as in example 30, it was evaluated.

(Example 40)
In Example 30, a trisphenol monomer having a structure represented by the above formula (T-2) (RT ^{1 to} R ^T6 are all hydroxymethyl groups) was replaced with a trisphenol having a structure represented by the above formula (T-23). An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 30, except that the monomers ( ^RT2 , ^RT4 and ^RT6 were all hydroxymethyl groups).

(Examples 41 to 49)
In Example 35, the charge transporting material having the structure represented by the formula (C-12) was replaced by a charge transporting material having the structure represented by the formula (C-4), respectively. A charge transport material having a structure represented by the formula (C-17); a charge transport material having a structure represented by the formula (C-30); ), A charge transport material having a structure represented by the formula (C-35), a charge transport material having a structure represented by the formula (C-38), and a charge transport material having the structure represented by the formula (C-35). An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 35, except that the charge transport material having the structure represented by the formula (C-55) was changed to the charge transport material having the structure represented by the formula (C-55). did.

(Example 50)
In Example 30, the above expression trisphenol monomer having a structure represented by ^{(T-2) (R T1} ~R T6 are all hydroxymethyl group), except that the following trisphenol oligomer Example 30 In the same manner, an electrophotographic photosensitive member was prepared and evaluated.

That is, a trisphenol oligomer obtained by reacting the above formula wherein the trisphenol monomer having a structure represented by ^{(T-2) (R T1} ~R T6 are all hydrogen atoms) with formaldehyde under alkaline conditions, methylene A trisphenol oligomer having a structure condensed via a group and having two or more hydroxymethyl groups (an average of eight). It is varnish-like.

(Examples 51 to 54)
In Example 50, trisphenol monomers having a structure represented by the above formula (T-2) (all of R ^{T1 to} R ^T6 are hydrogen atoms) have a structure represented by the above formula (T-11), respectively. trisphenol monomer ^(R T1 ^{to R T6} are all hydrogen atoms), tris phenol monomer ^(R T1 ^{to R T6} are all hydrogen atoms) having a structure represented by the formula (T-13), the formula (T-16) trisphenol monomer ^(R T1 ^{to R T6} are all hydrogen atoms), tris phenol monomer ^{(R T2, R T4, R} T6 are all hydrogen atoms having the structure represented by the formula (T-19) having the structure shown in ), And an electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 50.

(Example 55)
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 35 except that the thickness of the surface layer was changed to 1 μm in Example 35.

(Example 56)
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 35 except that the thickness of the surface layer was changed to 6 μm in Example 35.

(Example 57)
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 54 except that the surface layer was provided under the following conditions.

That is, in Example 54, the charge transport material having the structure represented by the above formula (C-12) was changed to a charge transport material having a structure represented by the following formula,

Ethyl alcohol was changed to methyl ethyl ketone as a solvent.

(Example 58)
Using an aluminum cylinder (JIS A3003 aluminum alloy) having a length of 260.5 mm and a diameter of 30 mm (JIS A3003 aluminum alloy) as a support, a 5% by mass methanol solution of a polyamide resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) is applied by dip coating. To form an intermediate layer having a thickness of 0.5 μm.

Next, as a charge generating substance, 3 parts of a crystalline form of hydroxygallium phthalocyanine having a strongest peak at 28.1 ° of Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction and polyvinyl butyral resin (trade name: Eslek BX) -1 and 2 parts of Sekisui Chemical Co., Ltd.) and 100 parts of cyclohexanone, dispersed for 1 hour by a sand mill using glass beads having a diameter of 1 mm, and diluted with 100 parts of methyl ethyl ketone. A coating solution was prepared, and the charge generating layer coating solution was dip-coated on the intermediate layer and dried at 90 ° C. for 10 minutes to form a charge generating layer having a thickness of 0.17 μm.

Next, 10 parts of a trisphenol monomer having a structure represented by the above formula (T-16) (RT ^{1 to} R ^T6 are all hydroxymethyl groups) and a charge transport having a structure represented by the above formula (C-12) 7 parts of the substance were dissolved in 40 parts of methyl ethyl ketone (solvent) to prepare a coating solution for the surface layer (charge transport layer), dip-coated on the charge generation layer, and dried by heating at 155 ° C. for 1 hour to form a film. A surface layer (charge transport layer) having a thickness of 17 μm was provided.

(Comparative Example 5)
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 30, except that the surface layer was not provided.

(Comparative Example 6)
In Example 37, the above expression trisphenol monomer having a structure represented by ^{(T-19) (R T2} , R T4, R T6 are all hydroxymethyl group), the structure represented by the formula (T-19) An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 37, except that the trisphenol monomer ( ^RT2 , ^RT4 and ^RT6 were all hydrogen atoms).

(Comparative Example 7)
An electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 30, except that the surface layer was provided as described below.

(5) 5 parts of a modified solution of a buret having a structure represented by the following formula (a solid content of 67% by mass);

Also, 6.87 parts of a charge transport material having a structure represented by the above formula (C-50) is dissolved in 50 parts of methyl ethyl ketone to prepare a coating solution for a surface layer, and is spray-coated on the charge transport layer by a spray coating method. It was applied and dried at room temperature for 5 minutes, and then heated and dried at 155 ° C. for 60 minutes to form a surface layer having a thickness of 3 μm. The mixing ratio of the coating solution for the surface layer is such that [the total number of moles of the hydroxy groups of the charge transport material having the structure represented by the above formula (C-50)]: [the total number of moles of the isocyanate groups of the above formula] is 45. : 55.

(Comparative Example 8)
An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 56 except that the surface layer did not contain a charge transporting material having the structure represented by the above formula (C-12).

Table 2 shows the evaluation results of Examples 30 to 58 and Comparative Examples 5 to 8.

Table 2 shows the measured values of the sensitivity and the residual potential of each of the examples and comparative examples, the shaving amount of the surface layer after the durability test of 10,000 sheets, the image quality of the printed image after the durability test, and the coating for the surface layer. The liquid showed stability.

(Example 59)
Using an aluminum cylinder (JIS A3003 aluminum alloy) having a length of 260.5 mm and a diameter of 30 mm (JIS A3003 aluminum alloy) as a support, a 5% by mass methanol solution of a polyamide resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) is applied by dip coating. To form an intermediate layer having a thickness of 0.5 μm.

Next, as a charge generating material, a crystal form of oxy having strong peaks at 9.0 °, 14.2 °, 23.9 ° and 27.1 ° at Bragg angles 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction. 13 parts of titanium phthalocyanine and 10 parts of polyvinyl butyral resin (trade name: Eslek BX-1, manufactured by Sekisui Chemical Co., Ltd.) were added to 250 parts of cyclohexanone, and dispersed by a sand mill using glass beads having a diameter of 1 mm for 1 hour. This was diluted with 50 parts of ethyl acetate to prepare a coating solution for a charge generation layer. The coating solution for a charge generation layer was dip-coated on the intermediate layer, and dried at 80 ° C. for 10 minutes. A charge generation layer having a thickness of 0.25 μm was formed.

Next, 10 parts of a charge transport material having a structure represented by the following formula:

And 10 parts of bisphenol Z-type polycarbonate (trade name: Z-200, manufactured by Mitsubishi Gas Chemical Co., Ltd.) were dissolved in a mixed solvent of 40 parts of monochlorobenzene / 20 parts of dichloromethane. This solution was dip-coated on the charge generation layer and dried with hot air at 100 ° C. for 80 minutes to form a charge transport layer having a thickness of 20 μm.

Next, antimony-containing tin oxide particles (trade name: T-1, manufactured by Mitsubishi Materials Corporation) that have been surface-treated (treatment amount: 8%) with a methylhydroxysiloxane compound (KF-99, manufactured by Shin-Etsu Chemical Co., Ltd.) ) 50 parts and 150 parts of ethanol was dispersed over 66 hours in a sand mill, then, bisphenol monomer ^(R B1 ^{to R B4} are all hydroxymethyl group having a structure represented by the formula (B-3)) 23 parts Was dissolved to prepare a coating solution for a surface layer, dip-coated on the charge transport layer, and dried with hot air at 145 ° C. for 1 hour to provide a layer (surface layer) having a thickness of 3 μm. The measurement of the film thickness was performed using an interference film thickness meter (manufactured by Otsuka Electronics Co., Ltd.).

(Example 60)
An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 59 except that a coating solution for a surface layer was prepared as described below.

That is, antimony-containing tin oxide particles (trade name: T-1, Mitsubishi) subjected to surface treatment (treatment amount: 7%) with (3,3,3-trifluoropropyl) trimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) Materials Co., Ltd.) (20 parts), antimony-containing tin oxide particles (trade name: T-1, treated with a methylhydroxysiloxane compound (KF-99, Shin-Etsu Chemical Co., Ltd.)) 30 parts of Mitsubishi Materials Corporation (150 parts) and 150 parts of ethanol were dispersed in a sand mill for 66 hours, and then 20 parts of polytetrafluoroethylene particles (average particle size: 0.18 μm) were added and dispersed. Thereafter, 24 parts of a bisphenol monomer having a structure represented by the above formula (B-3) (all of R ^{B1 to} R ^B4 are hydroxymethyl groups) were dissolved to prepare a coating solution for a surface layer.

(Examples 61 to 91)
In Example 60, a bisphenol monomer having a structure represented by the above formula (B-3) (all of R ^{B1 to} R ^B4 are hydroxymethyl groups) was replaced with a polyhydroxymethyl bisphenol monomer or a polyhydroxymethyl trisphenol monomer shown in Table 3. An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 60 except for the change.

(Comparative Example 9)
An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 59 except that the surface layer was not provided.

(Comparative Example 10)
In Example 59, antimony-containing tin oxide particles (trade name: T-1, Mitsubishi) whose surface layer was subjected to a surface treatment (treatment amount: 8%) with a methylhydroxysiloxane compound (KF-99, manufactured by Shin-Etsu Chemical Co., Ltd.) An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 59, except that the material was not contained.

(Comparative Example 11)
In Example 60, a bisphenol monomer having a structure represented by the above formula (B-3) (all of R ^{B1 to} R ^B4 are hydroxymethyl groups) was replaced with a bisphenol monomer having a structure represented by the above formula (B-51) ( An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 60, except that ^RB2 and ^RB3 were changed to hydrogen atoms.

(Comparative Example 12)
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 59, except that the surface layer was provided as described below.

That is, antimony-containing tin oxide particles (trade name: T-1, Mitsubishi) subjected to surface treatment (treatment amount: 7%) with (3,3,3-trifluoropropyl) trimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) Materials Co., Ltd.) (20 parts), antimony-containing tin oxide particles (trade name: T-1, treated with a methylhydroxysiloxane compound (KF-99, Shin-Etsu Chemical Co., Ltd.)) 30 parts of Mitsubishi Materials Corporation (150 parts) and 150 parts of ethanol were dispersed in a sand mill for 66 hours, and then 20 parts of polytetrafluoroethylene particles (average particle size: 0.18 μm) were added and dispersed. Thereafter, 22 parts of an acrylic resin having a structure represented by the following formula

Then, 5 parts of 2-methylthioxanthone was added as a photopolymerization initiator to prepare a coating solution for the surface layer, which was then dip-coated on the charge transport layer, and photocured at a light intensity of a high pressure mercury lamp of 800 mV / cm ² for 60 seconds. After that, drying was performed with hot air at 120 ° C. for 2 hours to provide a layer (surface layer) having a thickness of 3 μm.

(Measurement of volume resistivity)
A comb-shaped electrode having a gap of 180 μm was formed on a polyethylene terephthalate sheet by gold vapor deposition, and the surface layer coating solution used in Examples 59 to 91 and Comparative Examples 8 to 10 was applied thereon. Heat treatment was performed at 1 ° C. for 1 hour to form a film having a thickness of 3 μm, which was used as a sample. The measurement of the volume resistivity was performed by attaching the sample to a PA meter 4140B manufactured by Yokogawa Hewlett-Packard Co., Ltd., and applying 100V. The measurement environment is three environments of temperature / humidity: 23 ° C / 50% RH, 23 ° C / 5% RH, and 30 ° C / 80% RH.

Table 4 shows the measurement results of the volume resistivity.

(3000 sheet durability test)
Next, the electrophotographic photosensitive members produced in Examples 59 to 91 and Comparative Examples 8 to 10 were charged with a laser beam printer (trade name: LBP-NX: manufactured by Canon Inc., charging roller) having the configuration shown in FIG. The contact charging method used was adopted, and a voltage obtained by superimposing an AC voltage on a DC voltage was used as an applied voltage.) A durability test was performed on 3000 sheets under an environment of a temperature of 23 ° C. and a humidity of 50% RH. .

The evaluation items of the durability test were measurement of the amount of scraping of the electrophotographic photosensitive member surface during the durability test for 3000 sheets, and after each of the electrophotographic photosensitive members after the durability test was left for 24 hours in an environment of a temperature of 30 ° C. and a humidity of 80% RH, Again, the quality of the output image is checked by the laser beam printer, and the residual potential before the durability test is measured by the laser beam printer. The measurement of the residual potential was performed in an environment of a temperature of 23 ° C. and a humidity of 50% RH. The surface of the electrophotographic photosensitive member was charged to −700 V by a drum tester manufactured by Gentech Co., Ltd. The surface potential after 2 seconds was defined as the residual potential.

Table 5 shows the results of the 3,000 sheet durability test.

As shown in Tables 4 and 5, in Examples 59 to 91 of the present invention, the surface stability of the electrophotographic photosensitive member is excellent in environmental stability of electric resistance (volume resistivity), and the rise of the residual potential is most severe. Low residual potential even in a humid environment, no blurring or flow of images under high humidity, and keeps the film strength of the tough surface layer, less shaving due to durability, high stability, high durability Thus, it is possible to obtain a high-quality image.

FIG. 3 is a diagram illustrating an example of a layer structure of the electrophotographic photoreceptor of the present invention. FIG. 1 is a diagram illustrating an example of a schematic configuration of an electrophotographic apparatus including a process cartridge having an electrophotographic photosensitive member according to the present invention.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Layer containing polymer of polyhydroxymethylbisphenol monomer / oligomer and charge transport material 2 Charge transport layer 3 Charge generation layer 4 Support 5 Intermediate layer 6 Conductive layer 11 Electrophotographic photoreceptor 12 Axis 13 Charging means 14 Exposure light REFERENCE SIGNS LIST 15 developing means 16 transfer means 17 transfer material 18 fixing means 19 cleaning means 20 pre-exposure light 21 process cartridge 22 guide means

Claims (23)

In an electrophotographic photosensitive member having a photosensitive layer on a support,
The surface layer of the electrophotographic photoreceptor,
At least one of a charge transport material and conductive particles,
Polyhydroxymethylbisphenol monomer having 2 to 3 benzene rings and 2 to 4 hydroxymethyl groups, having a structure in which a bisphenol monomer having 2 to 3 benzene rings is condensed, and having 2 to 4 hydroxymethyl Condensation of a polyhydroxymethylbisphenol oligomer having a group, a polyhydroxymethyltrisphenol monomer having 3 to 4 benzene rings and 2 to 6 hydroxymethyl groups, and a trisphenol monomer having 3 to 4 benzene rings And a polymer obtained by polymerizing at least one selected from the group consisting of polyhydroxymethyl trisphenol oligomers having 2 to 6 hydroxymethyl groups having the above-mentioned structure. Photoreceptor. When the polyhydroxymethylbisphenol monomer is a single bond, a carbonyl group, an ether group, a thioether group, or a —CR ⁰¹ R ⁰² — group (R ⁰¹ and R ⁰² are each independently a hydrogen atom, a substituted or unsubstituted carbon atom, Represents an alkyl group having 1 to 4 atoms or a substituted or unsubstituted phenyl group, or a substituted or unsubstituted cycloalkylidene having 3 to 6 carbon atoms formed by combining R ⁰¹ and R ^02. Wherein both R ⁰¹ and R ⁰² are not substituted or unsubstituted phenyl groups.) A polyhydroxymethylbisphenol monomer having 2 to 3 benzene rings linked via a benzene ring. 2. The electrophotographic photosensitive member according to 1. The electrophotographic photosensitive member according to claim 2, wherein the polyhydroxymethylbisphenol monomer is a polyhydroxymethylbisphenol monomer having a structure represented by the following formula (1).

(In the formula (1), X ¹¹ is a single bond, a carbonyl group, an ether group, a thioether group, or a —CR ⁰¹ R ⁰² — group (R ⁰¹ and R ⁰² are each independently a hydrogen atom, a substituted or unsubstituted group. A substituted or unsubstituted alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted phenyl group; or a substituted or unsubstituted 3 to 6 carbon atoms formed by combining R ⁰¹ and R ^02. Wherein both R ⁰¹ and R ⁰² are not substituted or unsubstituted phenyl groups.) R ^{11 to} R ¹⁴ each independently represent a hydroxymethyl group, hydrogen An atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms other than a hydroxymethyl group, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, Others, a substituted or unsubstituted alkoxy group having 1 to 4 carbon atoms. ^However, at least two R 11 ^{to R 14} is a hydroxymethyl group.) Formula (1) X ¹¹ in the electrophotographic photosensitive member according to claim 3 which is divalent group having 3 or more carbon atoms. Formula (1) X ¹¹ in the electrophotographic photosensitive member according to claim 4 which is divalent or more 5 carbon atoms having a cyclic structure. The electrophotographic photoreceptor according to claim 3, wherein X ¹¹ in the formula (1) is a divalent group having a benzene ring. 4. The electrophotographic photoreceptor according to claim 3, wherein X ¹¹ in the formula (1) is an ether group, a thioether group, or a di (trifluoromethyl) methylene group. The polyhydroxymethylbisphenol oligomer is a single bond, a carbonyl group, an ether group, a thioether group, or a —CR ⁰¹ R ⁰² — group (R ⁰¹ and R ⁰² each independently represent a hydrogen atom, a substituted or unsubstituted carbon atom, Represents an alkyl group having 1 to 4 atoms or a substituted or unsubstituted phenyl group, or a substituted or unsubstituted cycloalkylidene having 3 to 6 carbon atoms formed by combining R ⁰¹ and R ^02. Wherein both R ⁰¹ and R ⁰² are not substituted or unsubstituted phenyl groups.) A polyphenol having a structure in which a bisphenol monomer having two or three benzene rings linked via The electrophotographic photoreceptor according to claim 1, which is a hydroxymethylbisphenol oligomer. The electrophotographic photoreceptor according to claim 8, wherein the polyhydroxymethylbisphenol oligomer is a polyhydroxymethylbisphenol oligomer having a structure in which a bisphenol monomer having a structure represented by the following formula (2) is condensed via a methylene group.

(In the formula (2), X ²¹ is a single bond, a carbonyl group, an ether group, a thioether group, or a —CR ⁰¹ R ⁰² — group (R ⁰¹ and R ⁰² are each independently a hydrogen atom, a substituted or unsubstituted group. A substituted or unsubstituted alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted phenyl group; or a substituted or unsubstituted 3 to 6 carbon atoms formed by combining R ⁰¹ and R ^02. Wherein both R ⁰¹ and R ⁰² are not substituted or unsubstituted phenyl groups.) R ^{21 to} R ²⁴ each independently represent a hydrogen atom or a halogen atom A substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, or a substituted or unsubstituted 1 to 4 carbon atom An alkoxy group.) The electrophotographic photosensitive member according to claim 9, wherein X ²¹ in the formula (2) is a divalent group having 3 or more carbon atoms. Formula (2) X ²¹ of in electrophotographic photosensitive member according to claim 10 which is divalent or more 5 carbon atoms having a cyclic structure. The electrophotographic photosensitive member according to claim 9, wherein X ²¹ in the formula (2) is a divalent group having a benzene ring. X ²¹ in the formula (2) is an ether group, a thioether group, or electrophotographic photosensitive member according to claim 9 which is a di (trifluoromethyl) methylene group. The electrophotographic photosensitive member according to claim 1, wherein the polyhydroxymethyl trisphenol monomer is a polyhydroxymethyl trisphenol monomer having a structure represented by the following formula (3).

(In the formula (3), Q ^{31 to} Q ³⁶ each independently represent a hydroxymethyl group, a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms other than a hydroxymethyl group, It represents an unsubstituted alkenyl group having 1 to 4 carbon atoms or a substituted or unsubstituted alkoxy group having 1 to 4 carbon atoms, provided that at least two of Q ^{31 to} Q ³⁶ are hydroxymethyl groups. Y ³¹ is a trivalent group having a structure represented by the following formula (31), a trivalent group having a structure represented by the following formula (32), or a trivalent group having a structure represented by the following formula (33) It is.

(In the formula (31), X ^{311 to} X ³¹³ each independently represent a single bond, a carbonyl group, an ether group, a thioether group, or a —CR ⁰¹ R ⁰² — group (R ⁰¹ and R ⁰² each independently represent , A hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms.) Q ^{311 to} Q ³¹³ each independently represent a hydrogen atom or a substituted or unsubstituted carbon atom. It represents an alkyl group of Formulas 1 to 4.)

(In Formula (32), Q ³²¹ represents a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms.)

(In the formula (33), X ³³¹ is a single bond, a carbonyl group, an ether group, a thioether group, or a —CR ⁰¹ R ⁰² — group (R ⁰¹ and R ⁰² are each independently a hydrogen atom or a substituted Q ³³¹ represents a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms.)) The electrophotographic photosensitive member according to claim 14, wherein at least one of X ^{311 to} X ³¹³ in the formula (31) or X ³³¹ in the formula (33) is a divalent group having 3 or more carbon atoms. body. Formula (31) at least one of ^X 311 ^{to X 313} in it, or, ^{X 331} in formula (33) is an ether group or an electrophotographic photosensitive member according to claim 14 which is a thioether group. The electrophotograph according to claim 1, wherein the polyhydroxymethyl trisphenol oligomer is a polyhydroxymethyl trisphenol oligomer having a structure in which a trisphenol monomer having a structure represented by the following formula (4) is condensed via a methylene group. Photoconductor.

(In the formula (4), Q ^{41 to} Q ⁴⁶ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted carbon atom having 1 to 4 carbon atoms. Or a substituted or unsubstituted alkoxy group having 1 to 4 carbon atoms, Y ⁴¹ is a trivalent group having a structure represented by the following formula (41), and represented by the following formula (42) A trivalent group having a structure or a trivalent group having a structure represented by the following formula (43).

(In Formula (41), X ^{411 to} X ⁴¹³ each independently represent a single bond, a carbonyl group, an ether group, a thioether group, or a —CR ⁰¹ R ⁰² — group (R ⁰¹ and R ⁰² each independently represent , A hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms.) Q ^{411 to} Q ⁴¹³ each independently represent a hydrogen atom or a substituted or unsubstituted carbon atom. It represents an alkyl group of Formulas 1 to 4.)

(In Formula (42), Q ⁴²¹ represents a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms.)

(In the formula (43), X ⁴³¹ is a single bond, a carbonyl group, an ether group, a thioether group, or a —CR ⁰¹ R ⁰² — group (R ⁰¹ and R ⁰² are each independently a hydrogen atom or a substituted And Q ⁴³¹ represents a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms.)) The electrophotographic photosensitive member according to claim 17, wherein at least one of X ^{411 to} X ⁴¹³ in the formula (41) or X ⁴³¹ in the formula (43) is a divalent group having 3 or more carbon atoms. body. At least one of the formula (41) ^X 411 ^{to X 413} in, or ^{X 431} in formula (43), an ether group or an electrophotographic photosensitive member according to claim 17 which is a thioether group. 20. The electrophotographic photoreceptor according to claim 1, wherein the charge transporting substance contained in the surface layer of the electrophotographic photoreceptor is a charge transporting substance having a hydroxy group. The electrophotographic photoreceptor according to claim 20, wherein the charge transport material having a hydroxy group is a charge transport material having at least one group selected from the group consisting of a hydroxyalkyl group, a hydroxyalkoxy group, and a hydroxyphenyl group. . 22. The electrophotographic photoreceptor according to claim 1 and at least one unit selected from the group consisting of a charging unit, a developing unit, a transfer unit, and a cleaning unit are integrally supported to form an electrophotographic apparatus. A process cartridge which is detachable. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, a charging unit, an exposing unit, a developing unit, and a transferring unit.

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