JPH07319180A - Electrophotographic photoreceptor and its production - Google Patents

Abstract

PURPOSE:To obtain a photoreceptor having high mechanical strength and excellent in potential by electrification, sensitivity and residual potential characteristics. CONSTITUTION:A carrier generating layer and a carrier transferring layer are successively laminated on an electric conductive substrate to obtain the objective electrophotographic photoreceptor. The carrier transferring layer consists of plural constituent layers and a resin obtd. by substituting repeating units represented by formula II for 1-90% of all the repeating units of a binder resin having repeating units represented by formula I and crosslinking the resultant binder resin with an isocyanate is contained in the top layer of the photoreceptor on the constituent layer side of the substrate. In the formulae I, II, each of R1 and R2 is H, alkyl, etc., each of R3 and R4 is H, halogen, alkyl, etc., and X is H, halogen, alkyl, aryl or a heterocyclic group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constitution of an electrophotographic photoreceptor, particularly an organic electrophotographic photoreceptor.

[0002]

2. Description of the Related Art As an electrophotographic photoreceptor, of course, electrophotographic characteristics such as good charging characteristics and sensitivity, and small dark decay, are added. In addition, printing durability, abrasion resistance and moisture resistance after repeated use. It is also required to have good physical properties such as properties, and ozone resistance (corrosion resistance) against ozone generated during corona discharge and ultraviolet rays during exposure.

In recent years, research and development using various organic photoconductive substances as materials for the photosensitive layer of an electrophotographic photoreceptor have been actively conducted. According to such an organic electrophotographic photosensitive member, since the photosensitive layer can be formed by coating, the manufacturing cost is low, pollution and environmental pollution can be prevented, and the organic electrophotographic photosensitive member can be easily processed into various shapes (drum sheet shape, etc.).

However, the organic electrophotographic photoreceptor has the following drawbacks, and there is a strong demand for solving these drawbacks.

(A) For example, when a layer is formed by binding a low molecular weight organic compound with a high molecular weight organic compound (binder), the mechanical strength is not always sufficient, and when the photoreceptor is repeatedly used, the developing blade is The surface of the photoconductor is scratched or worn due to rubbing or the like.

(B) The photoconductor is mainly used for negative charging. For example, as described in JP-A-60-247647, a thin carrier generating layer is provided on a support, and a relatively thick carrier is formed on the support. It is configured to have a transport layer.

The reason for this is that in the case of using negative charging, a hole transporting material can be used because the mobility of holes in the carrier is high, which is advantageous in terms of photosensitivity, while it has an electron transporting property. This is because there are almost no materials having excellent properties, or because they have carcinogenicity and teratogenicity, they cannot be used.

However, during negative corona discharge and during negative charging by the charger, a large amount of ozone is generated in the atmosphere, and environmental conditions deteriorate. For this reason, adsorption of ionic substances to the surface of the photoconductor and deterioration of the material of the photoconductor surface are caused, resulting in a decrease in potential during repeated use, which causes an increase in residual potential, a decrease in sensitivity, and a decrease in image quality. Lower.

(C) Since the equipment such as the electrophotographic photoreceptor is used for a long time under various conditions, it is often placed under the conditions of high temperature and high humidity. Therefore, there is a demand for a photoreceptor having high environmental resistance, but those currently being developed have not yet reached a sufficient level.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a photoreceptor having high mechanical strength and excellent in charging potential characteristics, sensitivity characteristics and residual potential characteristics and having high durability even in a high temperature and high humidity environment. That is.

[0011]

The present invention provides a photoreceptor comprising a conductive support and a carrier generating layer and a carrier transporting layer sequentially laminated on the conductive support, wherein the carrier transporting layer comprises a plurality of constituent layers. One of all repeating units of the binder resin having a repeating unit represented by the following general formula (1) on the outermost surface layer of the photoreceptor on the side where the constituent layer is provided with respect to the support.
% To 90% of a binder resin substituted by a repeating unit represented by the general formula (1 ′), further comprising a resin obtained by crosslinking with a isocyanate. Therefore, it is desirable to apply and manufacture a coating solution containing isocyanate with a circular amount control type coating machine.

[0012]

[Chemical 3]

(In the formula, R ₁ and R ₂ represent a hydrogen atom or a substituted or unsubstituted alkyl group, aryl group or phenyl group, and R ₁ and R ₂ may be bonded to each other to form a ring. R
₃ , R ₄ represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group. X represents a hydrogen atom, an oxygen atom, a halogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or a heterocyclic group. ) The outermost surface layer includes layers provided on the surface side of the photoreceptor such as a surface (protection) layer and a surface modified layer, as well as a case where a clear layer is not formed. In some cases, it may coincide with the outermost layer.

In the photoreceptor of the present invention, the binder resin having the repeating unit represented by the general formula (1) in at least the surface region of the carrier transport layer is 1% to 90% of the total repeating units in the general formula (1). It is important that the binder resin substituted with the repeating unit represented by ′) contains a resin obtained by crosslinking with a isocyanate.

That is, these resins are excellent in mechanical strength, scratch resistance, abrasion resistance, printing durability, and have good charging performance.
In particular, the surface of the forming layer has a high surface strength, a low dynamic friction coefficient, good transparency and insulating properties, and excellent compatibility with a carrier transport substance.

The "constituent layer of the carrier transport layer" may be two layers or three or more layers.

Next, the general formula constitution of the photoconductor of the present invention is shown in FIG.
For example.

In FIG. 1, the photosensitive member (a) is one in which a carrier generating layer 2 is provided on a conductive support 1, and a carrier transporting layer 3 composed of constituent layers 3A and 3B is provided on the carrier generating layer 2. Is. In the photosensitive member (b), the conductive support 1 is formed by providing the conductive layer 1B on the substrate 1A. In the photoconductor of (C), the surface protection layer 5 is provided on the photoconductor. In the photoreceptor of (d), the intermediate layer or the subbing layer 6 is provided between the carrier generating layer 2 and the conductive support 1 in the photoreceptor of (a).
Is provided.

Carrier transport layer constituent layer ((a) on the uppermost layer side)
In the examples of (d) to (d), the content ratio (weight ratio: carrier transport substance / binder substance) of the carrier transport substance to the binder substance in the constituent layer 3B) is 75% by weight or less, and more preferably 5 to 75% by weight. desirable. As a result, the film forming strength can be increased and the carrier transporting ability is not hindered.

Carrier transport layer constituting layer on the lowermost layer side ((a)
In the examples (d) to (d), the content ratio of the carrier transport material to the binder resin in the constituent layer 3A) is preferably 30% by weight or more, and more preferably 30 to 300% by weight. This makes it possible to increase the ability to inject photocarriers from the carrier generation layer. What is worth mentioning is that the content ratio of the carrier transport substance can be made very large, for example, 300% by weight,
This is possible because the film forming strength of the carrier transport layer constituting layer on the surface region side of the photoconductor is increased.

The lower constituent layer 3A preferably has a thickness of 5 to 50 μm, more preferably 5 to 30 μm. The upper constituent layer 3B preferably has a thickness of 0.1 to 10 μm, and a thickness of 0.5 to 5 μm.
It is more preferable that the thickness is μm.

The thickness of the carrier generation layer is preferably 0.01 μm to 10 μm, more preferably 0.1 to 5 μm. The thickness of the protective layer is preferably 2 μm or less, more preferably 1 μm or less.

Next, the material and prescription of the photosensitive member will be described.

1% to 90% of all the repeating units of the binder resin having the repeating unit represented by the general formula (1) used in the present invention are replaced by the repeating unit represented by the general formula (1 '). The binder resin can be obtained by partially substituting an OH group present in the repeating unit represented by the general formula (1) with another functional group. This is an improvement in that when the resin has many OH groups, the polarity is too high and the compatibility with ordinary carrier-transporting substances deteriorates. Further, the resin of the present invention can obtain high mechanical strength by being cured with various curing agents, and is excellent in compatibility with carrier transporting substances, electrical characteristics and durability. The proportion of the resin used in the present invention in which the OH group is substituted with another functional group is 1% to 90%, preferably 5% to 80%.
Hereafter, more preferably 10% or more and 70% or less.

The resin used in the present invention can be obtained by substituting the OH group in the resin having the repeating unit of the general formula (1) with another functional group. Examples thereof include a methylation reaction with dimethylsulfate, a reaction with an olefin under acidic conditions, a halogenation reaction, an acylation reaction, a reaction with a hydropyran, and the like, but the method for producing the resin of the present invention is limited to these methods. It is not something that will be done.

The resin having a repeating unit represented by the general formula (1) can be obtained from a bisphenol compound and epichlorohydrin. Although various substituents of R ₁ and R _{2 in} the formula can be considered depending on the bisphenol compound used, an alkyl group such as a methyl group, an ethyl group, a propyl group and a cyclohexyl group, a phenyl group, a benzyl group and a trifluoromethyl group are preferable, Especially bisphenol A
Type and bisphenol Z type are most preferable.

As a method for crosslinking the resin used in the present invention with an isocyanate, either a method by heat or light can be used, but generally it is crosslinked by heat. Examples of the isocyanate include, but are not limited to, toluylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate, hexamethylene diisocyanate, polyfunctional aromatic isocyanate, and other isocyanate compounds such as blocked isocyanate. . The structure of a typical one is shown below.

[0028]

[Chemical 4]

[0029]

[Chemical 5]

[0030]

[Chemical 6]

[0031]

[Chemical 7]

[0032]

[Chemical 8]

[0033]

[Chemical 9]

The ratio of isocyanate to resin is determined by the number of residual OH groups. Residual O in the general formula
Since one isocyanate group corresponds to one H group, the ratio NCO / OH of OH group and isocyanate group is 0.
It is preferably 01 to 1. If the amount of the isocyanate is too small, sufficient mechanical strength cannot be obtained, and if the amount of the isocyanate is excessive, the electrical characteristics will be deteriorated.

Carrier transport layer constituent layer ((a) on the uppermost layer side)
In the examples of (d) to (d), the binder material used in the carrier transport layer below the constituent layer 3B) may be a single binder or a combination of other binders when forming the carrier transport layer. Although any binder can be selected, a polymer that is soluble in a solvent and has a film-forming ability is preferable. Examples of such polymers include, but are not limited to, the following.

Polycarbonate resin Polycarbonate Z resin Acrylic resin Methacrylic resin Polyvinyl chloride Polyvinylidene chloride Polystyrene Styrene-butadiene copolymer Polyvinyl acetate Polyvinyl formal Polyvinyl butyral Polyvinyl acetal Polyvinylcarbazole Styrene-alkyd resin Silicon resin Silicon-alkyd resin Silicon-butyral resin Polyester Polyurethane Polyamide Epoxy resin Phenolic resin Vinylidene chloride-acrylonitrile copolymer Vinyl chloride-vinyl acetate copolymer Vinyl chloride-vinyl acetate-maleic anhydride copolymer Among these resins, polycarbonate resin or polycarbonate Z resin is most preferable.

As a carrier generating substance used in the electrophotographic photosensitive member of the present invention, a phthalocyanine compound, specifically, a crystalline type titanyl phthalocyanine such as A-type, B-type or Y-type, and a mixture of other phthalocyanines other than titanyl phthalocyanine. And various metal phthalocyanines represented by non-metal phthalocyanines such as X-type and τ-type and copper phthalocyanine, naphthalocyanines, and other porphyrin derivatives, azo compounds, perylene dyes such as imidazoleperylene and bisimidazopyridonoperylene. , Polycyclic quinone dyes such as ansanthuron and anthraquinone, perinone dyes, pyrylium compounds and eutectic complexes of pyrylium compounds, azurenium compounds and squarylium compounds.

Specific examples of the azo compound used in the present invention include compounds represented by the following "Chemical Formula 10" as described in JP-A No. 2-20877.

[0039]

[Chemical 10]

The bisimidazopyridonoperylene used in the present invention is represented by the general formula (2) or the general formula (3).

[0041]

[Chemical 11]

However, in the general formulas (2) and (3), Z represents an atomic group necessary for forming a substituted or unsubstituted divalent aromatic ring. Preferred examples of Z include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a pyridine ring, a pyrimidine ring, a pyrazole ring and an anthraquinone ring. Of these, a benzene ring and a naphthalene ring are preferable, and a benzene ring is particularly preferable. Z may or may not have a substituent, but an unsubstituted one is particularly preferable. As the substituent of Z, alkyl, alkoxy, aryl, aryloxy, acyl,
Acyloxy, amino, carbamoyl, halogen, nitro, cyano and the like can be mentioned, but an alkyl group is preferable.

In the following "Chemical formula 12" and "Chemical formula 13", the general formula (2),
Specific examples of the compound represented by (3) are shown below.

[0044]

[Chemical 12]

[0045]

[Chemical 13]

Various carriers can be used as the carrier transporting material used in the electrophotographic photosensitive member of the present invention. Typical examples thereof include oxazole, oxadiazole, thiazole, thiadiazole and imidazole. A compound having a nitrogen-containing heterocyclic nucleus and a condensed ring nucleus thereof, a polyarylalkane compound, a pyrazoline compound, a hydrazone compound, a triarylamine compound, a styryl compound, a poly (bis) styryl compound, a styryl compound Triphenylamine compound, β-
Examples thereof include phenylstyryltriphenylamine compounds, butadiene compounds, hexatriene compounds, carbazole compounds and condensed polycyclic compounds. Specific examples of this carrier transporting material include, for example, JP-A-61-107356.
The carrier transporting substances described in No.
The structures of particularly representative ones are shown in "Chemical formula 14" to "Chemical formula 19" below.

[0047]

[Chemical 14]

[0048]

[Chemical 15]

[0049]

[Chemical 16]

[0050]

[Chemical 17]

[0051]

[Chemical 18]

[0052]

[Chemical 19]

The carrier generation layer is made of a carrier generation material (CG
M) It can be formed by itself or by adding a suitable binder resin thereto, or by further adding a substance having a high mobility for carriers of a specific or non-specific polarity (that is, a carrier transporting substance). .

As a concrete forming method, C is formed on a support.
Examples thereof include a method in which GM is vacuum-deposited, and a method in which CGM is dissolved or dispersed in an appropriate solvent alone or together with an appropriate binder resin, and then applied (or dip coated) and dried.

In this latter method, a binder resin or a carrier-transporting substance may be added, in which case the ratio of carrier-generating substance: binder resin: carrier-transporting substance is 1: (0-100) :( 0-500), particularly 1: (0-10) :( 0-50).

For each of the constituent layers of the carrier transport layer, a solvent or a dispersion in which a carrier transport substance and a binder resin are dissolved and dispersed in a solvent is applied onto the carrier generation layer or other constituent layers of the carrier transport layer. It can be dried and formed.

It is also possible to prevent the binder resin for coating and forming the lower constituent layer 3A from being so much soluble (low solubility) in the solvent for coating and forming the upper constituent layer 3B. In this case, diffusion of the carrier transport substance or isocyanate into the lower constituent layer 3A, the lower constituent layer 3A
Can be prevented from swelling.

Each layer of the photoreceptor is dip coated, spray coated,
It can be formed by various coating methods such as blade coating, roll coating, spiral coating and slide hopper coating.

Further, the coating method of forming the upper constituent layer 3B and the lower constituent layer 3A can be different. For example, if the constituent layer 3A is formed by dip coating and the constituent layer 3B is formed by spray coating, dissolution and swelling of the lower constituent layer 3A can be prevented.

Conventionally, when coating and forming an organic photoconductive photoreceptor, various coating methods such as dip coating, blade coating, spin coating, beam coating and spiral coating have been used, but the coating method is easy. Further, since a smooth coating film can be easily obtained, the dip coating method of dipping and coating an object to be coated in a tank filled with a large amount of coating liquid is most popular.
However, in the dip coating method, the lower layer is dissolved when the photosensitive layers are laminated and coated. That is, when the lower layer is dissolved during the application of the surface layer, the coating film is destroyed, the functions of the surface layer and the lower layer are lost, and the performance of the photoreceptor is not exhibited. Also, when unevenness, streaks, spots, irregularities, etc. occur during application of the surface layer,
Image unevenness partially or locally differs in electrophotographic performance, image quality is degraded, and photoelectric and functional durability are also degraded, resulting in impaired electrophotographic performance. Further, in the dip coating method, the objects to be coated are dipped one by one in a tank containing a large amount of the coating liquid for coating, so that the coating liquid is wasted and the coating efficiency is poor. The coating solution in the inside may change to cause variations in electrophotographic performance. In particular, when a curing agent such as isocyanate is added as in the present invention, the change with time of the coating solution is severe.

Therefore, if a circular amount regulating type coating machine (for example, a circular slide hopper coating machine) is used for at least the constituent layer on the surface region side as in the present invention, the above problems can be solved, and in the present invention, at least the above. Even if different carrier transporting substances are used in the constituent layer on the surface region side and other constituent layers, against the problem that unnecessary mixing occurs due to elution of the lower layer carrier transporting substance to the coating liquid for the constituent layer on the surface region side However, it is an effective means.

The coating principle and characteristics of the circular amount control type coating machine are disclosed in JP-A-60-95440 and Japanese Patent Application No. 3-90250.

Coating by the coating apparatus of the present invention is performed as follows. That is, in a coating device that applies a coating liquid while moving a base material having a continuous peripheral surface formed endlessly, the coating liquid can continuously contact the base material so as to surround the peripheral surface of the base material. A hopper coating surface is formed so as to maintain a gap, and a coating liquid distribution chamber that directly supplies the coating liquid to the hopper coating surface through a coating liquid distribution slit is provided so as to surround the peripheral surface of the base material, and A coating liquid supply port for continuously supplying the coating liquid to the coating liquid distribution chamber is provided, and a coating liquid discharge port for discharging the coating liquid to the outside of the coating liquid distribution chamber is provided in the coating device. The coating liquid sent by a pump or the like into the liquid distribution chamber is supplied from the coating liquid supply port, the coating liquid from the supply port is distributed in the circumferential direction of the base material, and flows so as to surround the substrate. Through the distribution slit, To a outlet effluent from the coating liquid flow outlet. The coating liquid extruded from the outflow port flows out into the gap and is coated at the liquid contact portion on the peripheral surface of the base material.

The coating liquid supply device according to the present invention can be suitably used not only for a single-layer coating device but also for a weight coating device for simultaneously coating two or more coating liquids.

The protective layer, the intermediate layer or the undercoat layer can be formed by applying a solution prepared by dissolving a binder resin in a solvent and drying it.

A wide variety of solvents or dispersion media can be used as the solvent or dispersion medium for forming the photosensitive layer. For example, n-butylamine, ethylenediamine, N, N-dimethylformamide, acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, cyclohexanone, 4-methoxy-4-methyl-2-pentanone, tetrahydrofuran, dioxane, ethyl acetate, acetic acid n -Butyl, t-butyl acetate, methyl cellosolve, ethyl cellosolve, butyl cellosolve, ethylene glycol dimethyl ether, toluene, xylene, acetophenone, methanol, ethanol, propanol, butanol, cyclolomethane, 1,2-dichloroethane, trichloroethane, chloroform and the like. .

The photosensitive layer may contain an electron-accepting substance for the purpose of improving sensitivity, reducing residual potential, or reducing fatigue during repeated use. Examples of such an electron accepting substance include succinic anhydride, maleic anhydride, dibromosuccinic anhydride, phthalic anhydride, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, 3-nitrophthalic anhydride and 4-nitroanhydride. Phthalic acid, pyromellitic dianhydride, mellitic dianhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, 1,3,5-trinitrobenzene, p-nitrobenzonitrile, picryl chloride , Quinone chlorimide,
Chloranil, bromanil, dichlorodisiacy-p-benzoquinone, anthraquinone, dinitroanthraquinone, 9-
Fluorenylidene malononitrile, polynitro-9-fluorenylidene malononitrile, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, 3,5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3 Examples include 5,5-dinitrosalicylic acid, phthalic acid, meritic acid, and other compounds having a high electron renewal power.

The addition ratio of the electron-accepting substance is preferably 0.01 to 200 with respect to 100 by weight of the carrier-generating substance, and further,
0.1-100 is preferable.

Further, in the above-mentioned photosensitive layer, storability, durability,
For the purpose of improving the resistance to the environment, a deterioration inhibitor such as an antioxidant or a light stabilizer can be contained. Examples of compounds used for such purpose include chromanol derivatives such as tocopherol and its etherified or esterified compounds, polyarylalkane compounds,
Hydroquinone derivatives and mono- and dietherified compounds thereof, benzophenone derivatives, benzotriazole derivatives, thioether compounds, phosphonic acid esters, phosphite esters, phenylenediamine derivatives, phenol compounds, hindered phenol compounds, linear amine compounds, cyclic amine compounds, Hindered amine compounds are effective. Specific examples of particularly effective compounds include "IRGA
"NOX 1010", "IRGANOX 565" (manufactured by Ciba-Geigy), "Sumilyzer BHT", "Sumilyzer MD"
P ”(Sumitomo Chemical Co., Ltd.) and other hindered phenolic compounds“ Sanol LS-2626 ”,“ Sanol LS-622 ”
LD ”(manufactured by Sankyosha Co., Ltd.) and the like.

As the binder used for the intermediate layer, the protective layer and the like, those mentioned above for the carrier generating layer and the carrier transporting layer can be used, but in addition to them, nylon resin, ethylene-vinyl acetate copolymer, Ethylene resins such as ethylene-vinyl acetate-maleic anhydride copolymer and ethylene-vinyl acetate-methacrylic acid copolymer, polyvinyl alcohol, and cellulose derivatives are effective. Further, a curable binder that uses heat curing or chemical curing such as melamine, epoxy, or isocyanate can be used.

As the conductive support, a metal plate or a metal drum may be used, and a conductive polymer, a conductive compound such as indium oxide, or a thin layer of a metal such as aluminum or palladium may be applied, vapor deposited, laminated or the like. Therefore, the one provided on a substrate such as paper or plastic film can be used.

The photoconductor of the present invention can be used in electrophotographic copying machines, laser beam printers, CRT printers, electrophotographic plate making systems and the like. At that time, as a light source, He-N
e laser, semiconductor laser (780 nm, 680 nm, etc.), LED,
Various light sources such as halogen lamps can be used.

[0073]

EXAMPLES Examples of the present invention will be described below. In the text, "part" means "part by weight".

(Synthesis Example 1) 3 parts of 2,3-dihydropyran in a solution prepared by dissolving 10 parts of a phenoxy resin having a repeating unit represented by the general formula (1) (PKHH: Union Carbide Co.) in 100 parts of tetrahydrofuran. And 0.1 part of concentrated hydrochloric acid were added and reacted for 3 hours. After the reaction, the reaction product is precipitated in a large amount of methanol and further washed with methanol,
After drying, about 10 parts of resin was obtained. When the obtained resin was analyzed, about 60% of the OH groups in the resin before the reaction remained.

(Synthesis Example 2) A phenoxy resin was produced in the same manner as in Synthesis Example 1 except that a resin obtained from bisphenol A and epichlorohydrin was used in place of the phenoxy resin PKHH in Synthesis Example 1.

(Synthesis Example 3) A phenoxy resin was produced in the same manner as in Synthesis Example 1 except that a resin obtained from bisphenol Z and epichlorohydrin was used in place of the phenoxy resin PKHH in Synthesis Example 1.

Example 1 An undercoating layer made of polyamide resin and having a thickness of about 0.1 μm was provided on a drum-shaped aluminum conductive substrate (aluminum cylinder) having a diameter of 80 mm. Next, 30 parts of azo compound (G-1), 10 parts of butyral resin Elex B (BX-L), and 1600 of methyl ethyl ketone.
Part of the coating solution was applied onto the undercoat layer by dip coating so that the film thickness after drying was 1.5 μm to form a carrier generation layer.

Then, the carrier transport material (T-11) 500
Part, polycarbonate resin (Z300 manufactured by Mitsubishi Gas Chemical Co., Inc.) 5
A mixture of 60 parts was dissolved in 3000 parts of 1,2-dichloroethane by dip coating so that the film thickness after drying was 30 μm to form a support-side constituent layer of the carrier transport layer.

Further, a solution prepared by dissolving 100 parts of the carrier transporting material, 133 parts of the resin obtained in Synthesis Example 1 and 16 parts of isocyanate (7) in 1600 parts of a dichloromethane solvent was applied by dip coating to have a film thickness of 5 μm after drying. A carrier transport layer on the surface region side was formed. The carrier transport layer was cured at 100 ° C to 130 ° C for 2 hours. No residual isocyanate, which was not involved in crosslinking, was detected from this photoreceptor.

Example 2 Example 1 was repeated except that bisimidazopyridonoperylene (A-1) was used in place of the azo compound (G-1) as the carrier-generating substance in Example 1.
A photoconductor was prepared in the same manner as in.

Example 3 A photoconductor was prepared in the same manner as in Example 2 except that 8 parts of isocyanate was used.

Example 4 A photoconductor was prepared in the same manner as in Example 2 except that 24 parts of isocyanate was used.

Example 5 A photoconductor was prepared in the same manner as in Example 1 except that dibromoanthanthrone was used instead of the azo compound (G-1) as the carrier-generating substance in Example 1.

Example 6 Example 1 was repeated except that Y-type titanyl phthalocyanine having a clear peak at 27.2 ° of Bragg angle 2θ was used as the carrier generating substance in Example 1 instead of the azo compound (G-1). A photoconductor was prepared in the same manner as in.

Example 7 A photoconductor was prepared in which the thickness of the carrier transport layer on the surface region side after drying was 10 μm in Example 2.

Example 8 A photoconductor was prepared in the same manner as in Example 2 except that 50 parts of the carrier transporting material in the carrier transporting layer on the surface region side was used in Example 2 instead of 100 parts.

Example 9 A photoreceptor was prepared in the same manner as in Example 2 except that the isocyanate (1) was used instead of the isocyanate (7).

Example 10 A photoreceptor was prepared in the same manner as in Example 2 except that isocyanate (19) was used instead of isocyanate (7) in Example 2.

Example 11 A photoconductor was prepared in the same manner as in Example 2 except that the resin obtained in Synthesis Example 2 was used instead of the resin obtained in Synthesis Example 1 in Example 2.

Example 12 A photoconductor was prepared in the same manner as in Example 2 except that the resin obtained in Synthesis Example 3 was used instead of the resin obtained in Synthesis Example 1 in Example 2.

Example 13 A mixture of 500 parts of a carrier transporting material and 560 parts of a polycarbonate resin (Z300 manufactured by Mitsubishi Gas Chemical Co., Inc.) was added to 3000 parts of 1,2-dichloroethane on the carrier generating layer obtained in Example 2. The dissolved liquid was applied by dip coating so that the film thickness after drying would be 30 μm to form a support-side constituent layer of the carrier transport layer.

Further, 100 parts of the carrier transporting substance, 100 parts of the resin obtained in the synthesis example and 12 parts by weight of isocyanate (7) were added to dichloromethane so that the concentration of the carrier transporting substance on the surface side became equal to the concentration of the carrier transporting substance of the lower layer. A liquid dissolved in 1600 parts of a solvent was applied by dip coating to form a carrier transport layer on the surface region side having a thickness of 5 μm after drying. The carrier transport layer was cured at 100 ° C to 130 ° C for 2 hours. No residual isocyanate, which was not involved in crosslinking, was detected from this photoreceptor.

Comparative Example 1 An untreated phenoxy resin (PK was used in place of the resin obtained in Synthesis Example 1 in Example 2).
HH: manufactured by Union Carbide Co., Ltd., but using Example 2
When a photoconductor was prepared in the same manner as above, precipitation of a carrier transport substance was observed.

Comparative Example 2 A photoconductor was prepared in the same manner as in Example 2 except that isocyanate was not used.

(Comparative Example 3) A photoconductor having a carrier transport layer thickness of 25 µm was prepared in the same manner as in Example 2 except that the carrier transport layer on the surface region side was not provided.

(Comparative Example 4) In Example 2, 100 parts of the carrier transporting material, 133 parts of the resin obtained in the synthesis example and 20 parts of diphenylmethane diisocyanate were dissolved in 800 parts of a dichloromethane solvent on the formed carrier generating layer. The liquid was applied by dip coating to form a carrier transport layer so that the film thickness after drying was 25 μm, to prepare a photoreceptor.

Comparative Example 5 A photoconductor was prepared in the same manner as in Example 2 except that a protective layer made of urethane resin having a thickness of 5 μm was provided in place of the carrier transport layer on the surface side.

(Evaluation 1) The electrophotographic photosensitive member obtained as described above was subjected to the following photosensitive member characteristic evaluation by using a copying machine U-BIX4045 manufactured by Konica Corporation. The results are shown in Table 1.

1. Evaluation of electrical characteristics and repetitive characteristics By modifying the above copying machine and equipping it with a surface electrometer, the black paper potential, white paper potential and residual potential (1st and 50,000th) when the process of charging → exposure → static elimination was repeated 50,000 times Vb, Vw, and Vr) were measured and evaluated. The black paper potential here means the surface potential of the photoconductor when a black paper original having a reflection density of 1.3 is copied. Similarly, the blank sheet potential means the surface potential of the photoconductor when copying a blank sheet document having a reflection density of 0.0.

2. Image evaluation Check the image sample after copying 50,000 sheets to see if there are any image defects due to photoreceptor deterioration (thickness loss, electrical characteristics) such as background fog, white lines or black lines in halftone images, and uneven density. It was

3. Abrasion resistance evaluation The abrasion resistance of the photoconductor was evaluated by the amount of change in the photoconductor film thickness before and after the actual copying test of 50,000 copies. The thickness of the photoconductor is
It was measured with EDDY 560C manufactured by Fischer.

[0102]

[Table 1]

As can be seen from the results shown in Table 1, the photoreceptor of the present invention has good electrical characteristics and excellent abrasion resistance.

Example 14 In Example 2, a photosensitive member was formed by using a circular slide hopper only for the constituent layers on the surface side of the carrier transport layer.

Example 15 In Example 2, a photosensitive member was formed by using a circular slide hopper on both the support side and the surface region side of the carrier transport layer.

(Evaluation 2) The electrophotographic photosensitive member obtained as described above was evaluated as follows.

1. Evaluation of Electrophotographic Photosensitive Member Evaluation was performed by the same method as the above-described photosensitive member evaluation method.

2. Evaluation of surface property Regarding the surface property (smoothness) of the surface of the photoconductor, the presence or absence of coating defects such as coating unevenness, unevenness, and cracks was visually judged on the photoconductor.
The results are shown in Table 1.

As can be seen from the results in Table 1, the photoreceptor of the present invention in which the carrier transport layer was produced by using the circular slide hopper was superior in durability and durability to the photoreceptor produced by dipping the carrier transport layer. Both coatability shows equal or better characteristics. On the other hand, good results are shown with respect to electrical characteristics and repetitive characteristics, which shows that coating with a circular slide hopper is advantageous.

[0110]

INDUSTRIAL APPLICABILITY According to the present invention, an electrophotographic photosensitive material which is excellent in abrasion resistance, printing durability and ozone resistance, has high durability, and is less likely to have reduced potential stability due to repeated use, increased residual potential and reduced photosensitivity. The body can be provided.

[Brief description of drawings]

FIG. 1 is a layer configuration diagram of a photoconductor used in the present invention.

[Explanation of symbols]

 1 Conductive Support 2 Carrier Generation Layer 3 Carrier Transport Layer 3A Lower Constituent Layer 3B Upper Constituent Layer 5 Surface (Protection) Layer 6 Intermediate Layer

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Yoshihiko Eto 2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Stock Company

Claims (7)

[Claims] 1. An electrophotographic photosensitive member comprising a conductive support and a carrier generation layer and a carrier transport layer sequentially laminated on the conductive support, wherein the carrier transport layer comprises a plurality of constituent layers, and In the outermost surface layer of the photoreceptor on the side where the constituent layers are provided, 1% or more and 90% or less of all repeating units of the binder resin having a repeating unit represented by the following general formula (1) is represented by the general formula (1 '). An electrophotographic photoreceptor containing a resin obtained by crosslinking a binder resin substituted with a repeating unit represented by [Chemical 1] (Wherein, R _1, R ₂ represents a hydrogen atom or a substituted or unsubstituted alkyl group, an aryl group, a phenyl group, R ₁ and R ₂ may also form a ring .R _3, R ₄ represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, and X represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group or a heterocyclic group.) 2. The binder resin represented by the general formulas (1) and (1 ′), wherein R ₁ and R ₂ are methyl groups and R ₃ and R ₄ are hydrogen atoms. The electrophotographic photosensitive member described. 3. A binder resin represented by the general formulas (1) and (1 ′), R ₁ and R ₂ are bonded to each other to form a 6-membered ring composed of a hydrocarbon chain, and R ₃ and R ₄ are The electrophotographic photosensitive member according to claim 1, which is a hydrogen atom. 4. The electrophotographic photosensitive member according to claim 1, wherein the isocyanate compound is an aromatic diisocyanate. 5. The electrophotographic photoreceptor according to claim 1, wherein the isocyanate compound is a substituted or unsubstituted diphenylmethane diisocyanate. 6. The electron according to claim 1, wherein the concentration of the carrier transporting substance in the constituent layer on the side of the conductive support is higher than the concentration of the carrier transporting substance on the side of the constituent layer on the surface region side. Photoreceptor. 7. A method for producing a photoconductor in which a carrier generating layer and a carrier transporting layer are sequentially laminated on a conductive support, wherein the carrier transporting layer is composed of a plurality of constituent layers. 1% or more and 90% or less of all the repeating units of the binder resin having the repeating unit represented by the general formula (1) in the constituent layer on the surface side are replaced by the repeating unit represented by the general formula (1 ′). A method for producing an electrophotographic photosensitive member, characterized in that a coating liquid obtained by adding isocyanate to a coating liquid containing a binder resin is formed by a circular amount regulation type coating machine. [Chemical 2]