JP2520270B2 - Photoconductor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoconductor, for example, an electrophotographic photoconductor.

B. 2. Description of the Related Art In the electrophotographic copying machine of the Carlson method, after charging the surface of a photoconductor, an electrostatic latent image is formed by exposure, the electrostatic latent image is developed with toner, and then the visible image is printed on a paper. Etc., and fix it. At the same time, the photoconductor is subjected to removal of adhered toner, charge removal, and surface cleaning, and is repeatedly used for a long period of time.

Therefore, as an electrophotographic photosensitive member, of course, electrophotographic characteristics such as good charging characteristics and sensitivity and small dark attenuation are not only provided, but in addition, printing durability, abrasion resistance, moisture resistance, etc. in repeated use It is also required to have good physical properties and resistance (environmental resistance) to ozone generated during corona discharge and ultraviolet rays during exposure.

Conventionally, as electrophotographic photoreceptors, selenium, zinc oxide,
Inorganic photoreceptors having a photosensitive layer containing an inorganic photoconductive substance such as cadmium sulfide as a main component are widely used.

On the other hand, the use of various organic photoconductive materials as materials for the photosensitive layer of an electrophotographic photoreceptor has been actively developed and studied in recent years.

For example, Japanese Patent Publication No. 50-10496 describes an organic photoreceptor having a photosensitive layer containing poly-N-vinylcarbazole and 2,4,7-trinitro-9-fluorenone. However, this photoreceptor is not always satisfactory in sensitivity and durability. In order to improve such a defect, an attempt has been made to develop an organic photoreceptor having high sensitivity and high durability by separately sharing a charge generating function and a charge transporting function with different substances in a photosensitive layer. ing. In the so-called function-separated type electrophotographic photoreceptor, the substances exhibiting the respective functions can be selected from a wide range of substances, so that an electrophotographic photoreceptor having arbitrary characteristics can be produced relatively easily. It is possible.

Efforts to obtain an electrophotographic photoreceptor having excellent electrophotographic characteristics and film strength by using a low molecular weight organic compound as a charge transporting substance and using a substance generating an arbitrary charge and a polymer binder in combination. Has been done.

As the polymer binder, polycarbonate is excellent in terms of charging characteristics, repeating characteristics and the like. For example, polycarbonate having the following structural unit may be mentioned.

This polycarbonate has a structure in which two methyl groups are symmetrically bonded to the central carbon atom of bisphenol A. However, as a result of examination, it has been found that the above polycarbonate has the following drawbacks.

(1). Mechanical strength, especially scratch resistance and abrasion resistance are insufficient, and it is difficult to make the organic photoreceptor highly durable.

(2). Incompatible with carrier transport material (CTM), C
Crystals of TM tend to break out, which may cause cracks and cracks in the coating film.

(3). For example, when the above polycarbonate is used at a high concentration in the dip coating method, the coating liquid is apt to gel due to crystallization of the polycarbonate and the coating liquid has a short life.

(4). Gel-like substances form protrusions on the film surface during coating film formation, which causes tailing of the coating film, resulting in lower yields, or toner sticking to the surface protrusions when used as a photoreceptor. Then, it remains without being cleaned, and image defects due to so-called toner filming easily occur.

The reason why the polycarbonate is easily crystallized is
It is considered that in the above polycarbonate, the group bonded to the central carbon atom is the lowest methyl group, which gives rise to a high degree of molecular chain alignment.

In order to solve the problem of such a polycarbonate that is easily crystallized, it is proposed in JP-A-60-172044 and JP-A-60-172045 to use an amorphous polycarbonate for the photosensitive layer. This amorphous polycarbonate can solve the above-mentioned problems and can provide a photoreceptor having excellent mechanical strength, scratch resistance, and abrasion resistance.

However, as a result of repeated studies by the present inventor, it has been found that the photoreceptor using the above-mentioned amorphous polycarbonate is inferior in electrical characteristics upon repeated use, and the residual potential increases due to repeated use.

As described above, it is difficult to provide an electrophotographic photoreceptor having excellent film-forming properties, mechanical strength, scratch resistance, and abrasion resistance, and good electrical characteristics during repeated use, and both requirements are satisfied. There is a demand for the emergence of a photosensitive member.

C. OBJECT OF THE INVENTION It is an object of the present invention to provide a sensitized film having excellent film-forming properties, mechanical strength, scratch resistance, and abrasion resistance, and excellent electrical characteristics upon repeated use.

D. Structure of the Invention and Its Effect The present invention relates to a structural unit represented by the following general formula [I] and / or the following general formula [I
I] containing a polycarbonate having a structural unit represented by the main repeating unit, and the following general formula [II
Ib] is contained in the surface region of a compound having a hindered amine structural unit in its molecule.

General formula [I]: (However, in this general formula, R ¹ , R ² : hydrogen atom, a substituted or unsubstituted aliphatic group, a substituted or unsubstituted carbocyclic group, the group is a substituted or unsubstituted aromatic group, R ^At least one of ¹ and R ² is a bulky group, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , and R ¹⁰ : a hydrogen atom, a halogen atom, or a substituted or unsubstituted aliphatic group. Or a substituted or unsubstituted carbocyclic group.) General formula [II]: (However, in this general formula, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , and R ¹⁰ are the same as those described above, Z: a substituted or unsubstituted carbocycle or a substituted or It is a group of atoms necessary for forming an unsubstituted heterocycle.) In the above, the "surface area on the surface side provided with the photosensitive layer" is the area on the surface side of the photoconductor (the side opposite to the conductive substrate). Means a charge generation layer, a charge transport layer, a surface (protection) layer,
In addition to the layers provided on the surface of the photoconductor such as the surface improvement layer, if the layer is not clearly formed, for example, diffuse and add a "compound having a hindered amine structural unit in the molecule" to the surface region of the charge transport layer. This is intended to include cases such as those mentioned above.

In the present invention, it is important that a polycarbonate having the structural units represented by the above general formulas [I] and [II] as a main repeating unit is contained in the surface region on the side provided with the photosensitive layer.

That is, these polycarbonates have excellent mechanical strength, scratch resistance, abrasion resistance, printing durability, and good charging performance.
In particular, it has the characteristics that the surface is hard and has an appropriate slidability, and it has excellent transparency and insulating properties, and is also highly compatible with CTM. Further, at least one of the bulky (bulky) R ¹ and R ² is bonded to the central carbon atom of the bisphenol A portion of the above-mentioned polycarbonate, or the ring formed by Z is formed. 'And / or R ² or Z effectively prevents the molecular chains of the polycarbonate from being oriented in a specific direction. For this reason, the polycarbonate does not crystallize during the formation of the photosensitive layer and does not stick out to the film surface, the yield decreases due to abnormal protrusions, the characteristics such as image defects due to toner filming, and the coating solution quickly. It is possible to prevent gelation. Such a remarkable effect is more sufficiently exhibited if R ¹ and R ² in the above general formula [I] are different from each other or are asymmetrically bonded. In the above general formula [III], the ring formed by Z directly contributes to the above remarkable effect.

Further, in the present invention, “a compound having a hindered amine structural unit in the molecule (hereinafter, also referred to as a hindered amine compound or a hindered amine antioxidant) is contained in at least the surface region on the surface side provided with the photosensitive layer. The point is that it is important.

That is, a polycarbonate represented by the above general formulas [I] and [II] is used in combination with a polycarbonate having a structural unit represented by the above general formulas [I] and [II] as a main repeating unit and a hindered amine compound. It was possible to prevent the deterioration of the electrical characteristics during repeated use, which was a drawback of the above polycarbonate, while fully enjoying the above-mentioned effects due to the inclusion in the surface area of the photoreceptor. .

That is, by adopting such a configuration, electrical characteristics during repeated use were dramatically improved, and it was possible to prevent increase in residual potential, decrease in demand potential, and deterioration of sensitivity.

As described above, by using the polycarbonate having the structural units represented by the general formulas [I] and [II] as repeating units and the compound having the hindered amine structural unit in the molecule, the film-forming property and the mechanical property can be improved. It is possible to provide resistance to photosensitivity, which is excellent in strength, scratch resistance, and abrasion resistance, as well as charging performance during repeated use and excellent residual potential characteristics, and it is possible to dramatically improve the durability of the photoconductor as a whole. .

The reason why the compound having a hindered amine structural unit in the molecule exhibits the above-mentioned effects is considered to be as follows. That is, a compound having a hindered amine structural unit in its molecule is chemically stable in an environment such as an ozone atmosphere, exposure to ultraviolet rays and / or a high temperature environment. In particular, it shows a marked improvement effect on phenomena such as a decrease in charging ability and an increase in dark conductivity due to ozone and other active substances generated during charging. Furthermore, the effects of improving the charging potential and reducing the dark decay are obtained, and therefore, the initial characteristics are excellent regardless of the ozone concentration in the environment, and the fatigue and deterioration due to repeated use are extremely low, the receptive potential is lowered, and the sensitivity is reduced. It is possible to obtain excellent characteristics that are significantly reduced such as deterioration or increase in residual potential.

The mechanism of its action and effect is not clear, but it is thought to be due to the steric hindrance of the bulky atomic group to suppress the thermal vibration of the amino nitrogen atom and to prevent the influence of externally active substances.

The polycarbonate having a structural unit represented by the general formula [I] and / or [II] as a main repeating unit will be further described.

First, the structural units represented by the general formulas [I] and [II] will be described.

In the polycarbonate represented by the general formula [I], it is essential that at least one of R ¹ and R ² is a bulky group, but such a bulky group may have 3 or more carbon atoms. Desirably, it has a steric hindrance action such as hindering the molecular chain arrangement. Examples of such a bulky group include the following.

(1). (However, R ¹¹ is a hydrogen atom, an alkyl group such as a methyl group,
H ₂ ) _m COOR (R is an alkyl group, an alkyl ester group represented by m ≧ 1) (2). (3). An alkyl group represented by —C _m H _{2m + 1} (m ≧
4) (4). CH ₂ ) An alkyl ester group represented by _m COOR ¹² (wherein R ¹² is an alkyl group, m ≧ 2) When ^one of R ¹ and R ² is a bulky group, the other is a hydrogen atom or a methyl group. May be an alkyl group such as

Next, the groups represented by R ^{3 to} R ¹⁰ in the general formulas (I) and (II) include a hydrogen atom, a halogen atom such as Cl, Br, and F, an alkyl group such as a methyl group, and a carbon atom such as a cyclohexyl group. It may be a ring group.

Further, in the structural unit of the above general formula [II], Z may form a 5-membered or 6-membered carbon ring or a heterocycle, and examples of such a ring include a cyclohexyl ring and a cyclopentyl ring. , An acetyl group on a part of the ring,
A substituent such as an acetylamino group may be introduced.

Specific examples of the structural unit represented by the general formulas [I] and [II] include the following.

The polycarbonate of the present invention has the structural unit represented by the general formula [I] and / or the structural unit represented by the general formula [III] as a main repeating unit. Therefore, among the various structural units represented by the general formulas [I] and [II], those consisting of only one type (eg (I
-2) only)) It may be one obtained by co-condensing many kinds. Further, if necessary, a small amount of another repeating unit different from the repeating units represented by the general formulas [I] and [II] is contained for the purpose of improving physical, chemical and electrical properties. Condensation-type polycarbonate is also included in the polycarbonate of the present invention as long as the effects of the present invention are not impaired.

For example, as a specific example, polycarbonate co-condensed using a material in which a small amount of bisphenol A is mixed with 4,4-dihydroxyphenyl-1,1-cyclohexane, 4,4'-dihydroxyphenyl-1, Examples thereof include polycondensates of 1-cyclohexane and aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid.

In the above polycarbonate, the number of repetitions n
Is preferably 10 to 5000, more preferably 50 to 1000.

Further, among the above polycarbonates, polycarbonates represented by the following general formulas [I a] and [II a] are exemplified.

General formula [I a]: (However, in this ^{formula, R 1, R 2, R} 3, R 4, R 5, R 6, R 7, R 8, R 9, R 10: the same as those described above, n: 10 to 5000 < Preferably 50-1000>) General formula [IIa] (However, in this general formula, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , z, n are the same as those described above.

Among the polycarbonates of the present invention, those having the structural unit represented by the general formula [II] are preferable since the effects of the present invention can be more remarkably exhibited. Also, especially
Those having a cyclohexane ring bonded to the bisphenol A carbon atom such as (II-2), (II-4) and (II-9) are preferable, and the structural unit represented by (II-2) is Especially good.

Next, the compound having a hindered amine structural unit in the molecule will be further described.

The hindered amine structural unit in the present invention is a structural unit characterized by the presence of a bulky atomic group in the vicinity of an amino nitrogen atom, and both aromatic amine-based and aliphatic amine-based units fall into this category. In particular, in the case of an aliphatic amine system, a remarkable effect for the purpose of the present invention is provided.

Branched alkyl groups are generally preferred as bulky atomic groups.

Next, the "compound having a hindered amine structural unit in the molecule" will be exemplified, but it is not limited to the exemplified ones.

Examples of such compounds include the following general formulas [IIIa] and [III
Among the structural units represented by b], those having at least one in the molecule are preferable.

General formula (III a) General formula (III b) In the formula, R ¹³ and R ¹⁴ are alkyl groups and may have a substituent. However, one of R ¹³ and R ¹⁴ is a branched alkyl group.

R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ are a hydrogen atom or an alkyl group or an aryl group, preferably an alkyl group having 1 to 40 carbon atoms and optionally having a substituent.

Substituents for R ^{13 to} R ¹⁸ may be arbitrary such as aryl, alkoxy, acid, amide and halogen.

Z is an atomic group necessary for forming a nitrogen-containing alicyclic ring, and is preferably an atomic group forming a 5-membered ring or a 6-membered ring. Preferred ring structures are piperidine, piperazine, morpholine, pyrrolidine, imidazolidine, oxazolidine,
Thiazolidine, selenazolidine, pyrroline, imidazoline, isoindoline, tetrahydroisoquinoline, tetrahydropyridine, dihydropyridine, dihydroisoquinoline, oxazoline, thiazoline, selenazoline, each ring such as pyrrole, particularly preferably pyridine,
Each ring of piperazine and pyrrolidine.

Further, one of each of the groups R ¹⁵ , R ¹⁶ and each group of R ¹⁷ , R ¹⁸ may be incorporated into Z by providing Z with a double bond.

Y ¹ is an organic residue, and Y ² and Y ³ are hydrogen atoms or organic residues, preferably organic residues. This organic residue is another hindered amine structural unit or another organic structural unit and constitutes a part of the molecular structure of the compound according to the present invention as shown in the above general formulas [IIIa] and [IIIb]. . Of course, the compound thus constituted has the general formula [III
a), [IIIb] may have a plurality of structural units represented by each in the molecule, or may have a plurality of units represented by the same general formula in the molecule. good.

The above-mentioned organic residue is a compound having characteristics such as crystallinity, compatibility with a binder, solubility in an organic solvent, bleed-out property (diffusibility to the surface) or non-bleed-out property (non-diffusibility). Various chemical structures are used for imparting to the compound, but any of them can be used because these structures do not lose the potency of the hindered amine atomic group.

Further, as the compound having at least a hindered amine structural unit, a compound having at least one of structural units represented by the following general formulas [IIIc], [IIId] or [IIIe] in the molecule is particularly preferable.

General formula (III c) General formula (III d) General formula (III e) In the formula, R ^{19 to} R ³⁴ are a hydrogen atom or an alkyl group, and the alkyl group preferably has 1 to 40 carbon atoms and has a substituent (for example, aryl, alkoxy, amide, halogen, etc.). You may.

Y ^{4 to} Y ⁹ are hydrogen atoms or organic residues, preferably organic residues, and the organic residues mentioned above for Y ^{1 to} Y ³ are also mentioned.

Hereinafter, typical specific examples of the hindered amine-based compound will be shown, but of course the present invention is not limited thereto.

Exemplified compound group: those represented by the general formula [III f]: (III-1) to (III
-7) General formula [III f]: These compounds are known as light stabilizers and can be easily synthesized and obtained.

Further, for example, in the general formula [IIIa], [IIIb], [III
c], a compound represented by [III d] is tinuvin 62
2,622LD, 765,770 (Ciba Geigy), Mark LA-
Commercially available products such as 57 (Adeka Argus Co., Ltd.) and Cimasorb 944LD (Timosa Co., Ltd.) can be obtained, or they can be synthesized by referring to the method described in JP-A-59-133543.

The photoreceptor of the present invention comprises, for example, as shown in FIG. 1, a support 1 (a conductive support or a sheet on which a conductive layer is provided), a charge generating substance (CGM) and, if necessary, a binder resin. A charge generation layer 2 containing C (hereinafter sometimes referred to as CGL) is used as a lower layer, and a charge transport layer 3 containing a charge transport material (CTM) and optionally a binder resin (hereinafter CT).
The photosensitive layer 4A has a layered structure in which the upper layer is
2, a photosensitive layer 4B having a laminated structure having CTL3 as a lower layer and CGL2 as an upper layer on the support 1 as shown in FIG. 2, and as shown in FIG. 3 on the support 1 Single-layer photosensitive layer containing CGM, CTM, and optionally binder resin
One provided with 4D, a photosensitive layer having a laminated structure as shown in FIG.
4B (see FIG. 2) provided with a protective layer 5 and the like.

The CGL may contain both CGM and CTM, and a protective layer (OCL) may be provided on the photosensitive layers 4A and 4D. An intermediate layer and an undercoat layer may be provided between the support and the photosensitive layer. It may be provided.

In the present invention, the polycarbonate having the structural units represented by the general formulas [I] and [II] as main repeating units and the compound having a hindered amine structural unit in the molecule are CGL2 in FIG. 2 and CTL3 in FIG. , A single-layer photosensitive layer 4D shown in FIG. 3, a protective layer (OCL) 5 shown in FIG. 5, and the like. The polycarbonate and the hindered phenol compound are both CGL2 in FIG. 1 and in FIG.
It may be contained in a region other than the surface region of the photoreceptor such as CTL3 and the photosensitive layer 4B in FIG. 4, and may be contained in a plurality of layers in the same photoreceptor.

When the present invention is applied to a photoreceptor having a laminated structure in which CGL is the upper layer and CTL is the lower layer as illustrated in FIGS. 2 and 4, the effects of the present invention can be particularly remarkably exhibited. Since such a photoreceptor has a small layer thickness on the surface side, printing durability, abrasion resistance, scratch resistance, and the like have been particularly problematic since then. This is because the effect of improving the sex is considered to be more remarkable.

The addition amount of the binder amine antioxidant of the present invention is
Although not constant depending on the layer structure of the photoconductor, the type of CTM, etc., the following range is preferable for the time being.

When it is added to the charge generation layer, 0.01 to 50 parts by weight is preferable relative to 100 parts by weight of the polycarbonate of the present invention, and 0.1 to 10 parts by weight.
It is preferable to use parts by weight.

When added to the charge transport layer, it is preferably 0.01 to 50 parts by weight, and 0.1 to 10 parts by weight based on 100 parts by weight of the polycarbonate of the present invention.
It is more preferable to use the weight part.

Further, when it is added to the surface (protective) layer or the photosensitive layer having a single-layer structure, it is preferable to use the same amount as above.

Thus, it is desirable to limit the amount of the above compound added. That is, if the amount is too small, the residual potential may increase during repeated or continuous use, which may cause fog in the image.

On the other hand, if the amount is too large, the sensitivity tends to decrease, and fog or contrast tends to decrease.

Next, as the charge generating substance suitable for the present invention, any of inorganic pigments and organic dyes can be used as long as they absorb visible light and generate free charges. In addition to inorganic pigments such as amorphous selenium, trigonal selenium, selenium-arsenic alloy, selenium-tellurium alloy, cadmium sulfide, cadmium selenide, cadmium sulphide selenide, mercury sulfide, lead oxide and lead sulfide, Organic pigments such as those shown may also be used.

(1) Monoazo pigments, polyazo pigments, metal complex salt azo pigments, pyrazolone azo pigments, azo pigments such as stilbene azo and thiazole azo pigments (2) Perylene pigments such as perylene anhydride and perylene imide (3) Anthraquinone derivatives Anthraquinone-based or polycyclic quinone-based pigments such as anthanthrone derivatives, dibenzpyrenequinone derivatives, pyrantrone derivatives, violanthrone derivatives and isobiolanthrone derivatives (4) Indigoide pigments such as indigo derivatives and thioindigo derivatives (5) Metal phthalocyanine And phthalocyanine pigments such as metal-free phthalocyanine (6) Carbonium pigments such as diphenylmethane pigments, triphenylmethane pigments, xanthene pigments and acridine pigments (7) azine pigments, oxazine pigments and thiazine pigments Quinone imine pigments (8) Methine pigments such as cyanine pigments and azomethine pigments (9) Quinoline pigments (10) Nitro pigments (11) Nitroso pigments (12) Benzoquinone and naphthoquinone pigments (13) Naphthalimide pigments (14) Perylene-based pigments such as bisbenzimidazole derivatives Various azo pigments having electron-withdrawing groups are used because of their excellent electrophotographic characteristics such as sensitivity, memory development, and residual potential. Therefore, a polycyclic quinone pigment is most preferable.

The details are unclear, but probably because polycyclic quinones are inert to ozone.

Examples of the phthalocyanine-based pigment include the following.

(IV-1) X-type metal-free phthalocyanine (IV-2) τ-type metal-free phthalocyanine (IV-3) Chloroaluminum phthalocyanine (IV-4) Titanyl phthalocyanine (IV-5) Vanadyl phthalocyanine (IV-6) ε-type copper Phthalocyanine (IV-7) chloroindium phthalocyanine For phthalocyanine pigments, for example, Japanese Patent Publication No. 49-
It is described in Japanese Patent No. 4338.

Examples of the azo pigment that can be used in the present invention include those shown in the following exemplary compound groups [V] to [IX].

For compounds of the exemplified compound group [IX], see JP-A-58-19
It is described in Japanese Patent No. 4035.

Further, the following exemplary compound groups [X] to [X II] composed of polycyclic quinone pigments can be most preferably used as CGM.

Next, the CTM usable in the present invention is not particularly limited, and examples thereof include oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazolidine derivatives, bisimidazolidines. Derivatives, styryl compounds, hydrazone compounds, pyrazoline derivatives, oxazolone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, poly-N-vinylcarbazole, poly-1-vinylpyrene One or two or more selected from poly-9-vinylanthracene and the like may be used. It is also possible to use different charge transport materials for the charge generation layer and the charge transport layer.

However, in addition to the excellent ability to transport holes generated during light irradiation to the support side, those suitable for combination with the CGM are preferably used, and such CTMs include, for example, the following general formulas [XIII] and [XIV ] The compound shown by these is mentioned.

Further, amine derivatives represented by the following exemplified compound group [XXI] can also be used as CTM.

As CTM, hydrazone compounds represented by the following exemplified compound groups [XV] to [XIX] can also be used.

Further, a pyrazoline compound represented by the following exemplified compound [XX] can also be used as CTM.

The layer structure of the photosensitive layer of the photoreceptor of the present invention has a laminated structure and a single layer structure as described above, CTL, CGL, a single layer photosensitive layer or
One or more electron-accepting substances can be contained in any one of the OCLs or in a plurality of layers for the purpose of improving sensitivity, reducing residual potential or fatigue during repeated use.

Examples of electron-accepting substances that can be used in the photoreceptor of the present invention include succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, and 3-nitrophthalic anhydride. , 4-nitrophthalic anhydride, pyromellitic anhydride, mellitic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinotrobenzene, 1,3,5-trinitrobenzene, paranitrobenzo Nitrile, picryl chloride, quinone chloride,
Chloranil, bulmannyl, 2-methylnaphthoquinone, dichlorodicyanoparabenzoquinone, anthraquinone, dinitroanthraquinone, trinitrofluorenone, 9-
Fluorenylidene- [dicyanomethylene malonodinitrile], polynitro-9-fluorenylidene- [dicyanomethylene malonodinitrile], picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, 3,5-dinitrobenzoic acid, pentafluorobenzoic acid Acid, 5-nitrosalicylic acid,
Examples include 3,5-dinitrosalicylic acid and phthalic acid.

Further, silicone oil may be present as a surface modifier. Further, an ammonium compound may be contained as a durability improver.

In the present invention, in addition to the polycarbonates represented by the general formulas [I] and [II], other binder resins can be used in combination.

Examples of such binder resin include polyethylene, polypropylene, acrylic resin, methacrylic resin,
Vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyhydroxystyrene resin, polyester resin, alkyd resin, addition-polymerizable resin such as polycarbonate resin other than the present invention, silicone resin, melanin resin, polyaddition Resins, polycondensation resins and copolymer resins containing two or more of the repeating units of these resins, for example vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl acetate-maleic anhydride copolymer resins, etc. In addition to the above insulating resin, a polymer organic semiconductor such as poly-N-vinylcarbazole may be used.

Further, the intermediate layer functions as an adhesive layer or a barrier layer, and in addition to the binder resin, for example, polyvinyl alcohol, ethyl cellulose, carboxymethyl cellulose, vinyl chloride-vinyl acetate copolymer, vinyl chloride-
Vinyl acetate-maleic anhydride copolymer, casein, N-
Alkoxymethylated nylon, starch, etc. can be used together.

Next, as the conductive support for supporting the photosensitive layer, aluminum, a metal plate such as nickel, a metal drum or a metal foil, aluminum, tin oxide, a plastic film deposited with indium oxide or the like, or a paper coated with a conductive substance, Films or drums such as plastic can be used.

CGL can be provided by a method in which CGM is dissolved or dispersed in a suitable solvent alone or together with a suitable binder resin, and the composition is dried.

A ball mill, homomixer, sand mill, ultrasonic disperser, attritor, or the like is used for CGM dispersion.

Examples of the solvent used for forming CGL include N, N-dimethylformamide, benzene, toluene, xylene,
Monochlorobenzene, 1,2-dichloroethane, dichloromethane, 1,1,2-trichloroethane, tetrahydrofuran, methyl ethyl ketone, ethyl acetate, butyl acetate and the like can be mentioned.

The CGM is preferably 20 parts by weight or more, and particularly preferably 25 to 400 parts by weight, per 100 parts by weight of the binder resin in CGL.

The film thickness of the CGL formed as described above is preferably 0.01 to 10 μm, particularly preferably 0.1 to 5 μm.

In addition, CTL makes the above-mentioned CTM the same as the above-mentioned CGL,
That is, alone or with the binder resin described above,
It can be formed by coating and drying the dispersed material.

The CTM is 20 to 200 parts by weight, preferably 30 to 150 parts by weight, per 100 parts by weight of the binder resin in the CTL.

The film thickness of the CTM formed is preferably 5 to 50 μm, particularly preferably 5 to 30 μm.

The protective layer may contain an electron-accepting substance, and may further contain an ultraviolet absorber or the like for the purpose of protecting CGM, if desired, and preferably has a thickness of 2 μm or less, more preferably 1 μm or less. It is formed thick.

In coating and forming the above layers, for example, dip coating, spray coating, blade coating, roll coating and the like are used.

E. Examples Hereinafter, examples of the present invention will be described, but the embodiments of the present invention are not limited thereto.

Example 1 A vinyl chloride-vinyl acetate-maleic anhydride copolymer "ESREC" was formed on an aluminum drum substrate having an outer diameter of 80 mm.
MF-10 "(made by Sekisui Chemical Co., Ltd.) with a thickness of about 0.1 μm
Was provided. Next, 60 g of the polycyclic quinone pigment represented by the structural formula X-3 was crushed with a ball mill for 24 hours, and bisphenol A type polycarbonate "Panlite L-125
0 "(manufactured by Teijin Kasei) 30 g 1,2-dichloroethane 3000 ml
Was added and dispersed for a further 24 hours, and the resulting dispersion was dip-coated on the intermediate layer and sufficiently dried to form a CGL having a thickness of about 0.3 mm.

On the other hand, the styryl compound represented by the structural formula XIII-61 described above.
352.5 g, 7.1 g of the hindered amine compound represented by Structural Formula III-3, and a polycarbonate having a main repeating structural unit represented by Structural Formula II-2, “Iupilon Z-
200 g (manufactured by Mitsubishi Gas Chemical Co., Inc.) and 3,000 ml of 1,2-dichloroethane, and the resulting solution is dip-coated on the CGL and dried at a temperature of 80 ° C. for 1 hour to obtain a CTL having a thickness of 20 μm. To form an electrophotographic photosensitive member according to the present invention.

Example 2 In the same manner as in Example 1 except that the polycarbonate "Iupilon Z-200", which is a repeating unit represented by the structural formula II-2 used in CTL, was used as the binder of CGL in Example 1, An electrophotographic photoreceptor was manufactured.

Example 3 In Example 2, 0.6 g of a hindered amine compound represented by Structural Formula III-3 was further added to CGL (2 wt.
%) Was added to prepare an electrophotographic photosensitive member in the same manner as in Example 2.

Example 4 The same intermediate layer as in Example 1 was provided on an aluminum drum substrate having an outer diameter of 80 mm. Next, acrylic resin "Dinal BR-85"
(Mitsubishi Rayon Co., Ltd.) 15g to 1,2-dichloroethane 3000ml
Disazo pigment represented by structural formula IX-15 in a solution dissolved in
30 g was added and dispersed with a sand grinder for 8 hours. This dispersion is dip-coated on the intermediate layer to form a 0.2 μm thick CGL
Was formed.

On the other hand, the hydrazone compound 35 represented by the structural formula X IX-25
450 g of polycarbonate consisting of 2.5 g, a hindered amine compound represented by Structural Formula III-19 17.6 g, and a repeating unit represented by Structural Formula II-4 (viscosity average molecular weight is about 30,000)
Are dissolved in 3000 ml of 1,2-dichloroethane, the resulting solution is dip-coated on the CGL and dried at a temperature of 80 ° C. for 1 hour to form a CTL having a thickness of 20 μm. Manufactured body.

Example 5 In Example 4, X-type metal-free phthalocyanine was used in place of the disazo pigment, and a structural formula XX- was used as a charge-transporting substance.
An electrophotographic photoreceptor of the present invention was produced in the same manner as in Example 4 except that the compound shown in 6 was used.

Example 6 The same intermediate layer as in Example 1 was provided on an aluminum drum substrate having an outer diameter of 80 mmφ. Next, the same CTL solution as in Example 1 was applied onto the intermediate layer by dip coating to form a CTL having a thickness of 15 μm.

On the other hand, 30 g of the polycyclic quinone pigment represented by the structural formula X-3 was added to a solution prepared by dissolving 60 g of the polycarbonate "Iupilon Z-200" composed of the repeating unit represented by the structural formula II-2 in 3000 ml of monochlorobenzene, and the mixture was placed on a ball mill for 24 hours. Disperse,
Further, 45 g of the styryl compound represented by the structural formula XIII-20 and 2.2 g of the hindered amine compound represented by the structural formula III-8 were added to and dissolved in this dispersion. The resulting dispersion is spray coated on the CTL to form a 5 μm thick CGL,
An electrophotographic photoreceptor (positive charging type) of the present invention as shown in FIG. 2 was obtained.

Example 7 A photoconductor of Example 6 was manufactured, and a protective layer was provided thereon by the following method to obtain a photoconductor as shown in FIG. Structural formula II-2
An electrophotographic photosensitive member obtained in the same manner as in Example 6 by dissolving 30 g of a polycarbonate "Iupilon Z-200" having a repeating unit represented by the following formula and 0.6 g of a hindered amine compound represented by the structural formula III-33 in 3000 ml of monochlorobenzene. It was spray-coated on the body to form a protective layer having a thickness of 2 μm.

Example 8 Example 1 was performed on an aluminum drum substrate having an outer diameter of 80 mmφ.
An intermediate layer was provided in the same manner as in. Then, to a solution prepared by dissolving 300 g of polycarbonate "Iupilon Z-200" consisting of the repeating unit represented by the structural formula II-2 in 3000 ml of monochlorobenzene, 60 g of CGM represented by the structural formula V III-7 was added, and the mixture was placed in a ball mill for 24 hours. Disperse, and further into this dispersion the structural formula
225 g of CTM represented by V III-37 and 3 g of a hindered amine compound represented by structural formula III-24 were added and dissolved. The obtained dispersion was applied onto the intermediate layer and dried to form a photosensitive layer, and an electrophotographic photosensitive member of the present invention as shown in FIG. 3 was obtained.

Comparative Examples 1 to 5 Photoreceptors of Comparative Examples 1 to 5 were produced in the same manner as in Examples 1 to 5, except that the hindered amine compound was omitted from CTL in Examples 1 to 5.

Comparative Example 6 A photoconductor of Comparative Example 6 was produced in the same manner as in Example 6 except that the hindered amine compound was removed from CGL.

Comparative Example 7 A photoconductor of Comparative Example 7 was produced in the same manner as in Example 7, except that the hindered amine compound was removed from the protective layer.

Comparative Example 8 In the same manner as in Example 8 except that the hindered amine-based compound was removed from the photosensitive layer having a single layer structure in Example 8,
A photoconductor of Comparative Example 8 was manufactured.

Comparative Example 9 In Example 1, the CTL binder resin was changed from the polycarbonate of the present invention to bisphenol A type polycarbonate "Panlite L-1250" (manufactured by Teijin Chemicals Ltd.). A photosensitive member of Comparative Example 9 was manufactured in the same manner as in Example 1 except for the above.

Comparative Example 10 In Example 6, the binder resin of CGL was changed from the polycarbonate of the present invention to bisphenol A type polycarbonate "Panlite L-1250". Otherwise in the same manner as in Example 6, a photoconductor of Comparative Example 10 was manufactured.

Comparative Example 11 In Example 7, the binder resin of the protective layer was changed from the polycarbonate of the present invention to bisphenol A type polycarbonate "Panlite L-1250". A photosensitive member of Comparative Example 11 was manufactured in the same manner as in Example 7 except for the above.

Comparative Example 12 In Example 8, the binder resin of the photosensitive layer having a single-layer structure was changed from the polycarbonate of the present invention to bisphenol A type polycarbonate "Panlite L-1250". A photosensitive member of Comparative Example 12 was manufactured in the same manner as in Example 8 except for the above.

The electrophotographic photosensitive member sample obtained as described above was mounted on the U-Bix1550MR manufactured by Konishi Rokusha Kogyo Co., Ltd., and a real copying test of 50,000 copies was performed, and the black paper potential V _b , the white paper potential V _w , and the residual potential.
V _r was measured. Further, the amount of film thickness loss and the occurrence of image scratches after 50,000 copies were examined. However, in the table, V _b , V _w , and V _r (initial values) and the respective fluctuation amounts after copying 50,000 times Δ | V _b |, Δ
| V _w | and Δ | V _r |.

However, Examples 6, 7, 8 and Comparative Examples 6, 7, 8, 10,
The photoreceptors 11 and 12 were tested by changing the polarity of charging and transfer from negative to positive and changing the developer to a negatively chargeable two-component developer.

The black paper potential here is a black paper document with a reflection density of 1.3, and represents the surface potential of the photoconductor when the above copying cycle is performed, and the blank paper potential is the photoconductor potential when a white paper is the document. Represents the surface potential. The measurement results are shown in the table.

However, in the table, "actual-" represents an example, and "ratio-" represents a comparative example.

As is clear from the above examples and comparative examples, the electrophotographic photosensitive member of the present invention has excellent wear resistance and scratch resistance, and the black paper potential (V _b ) decreases even when a large number of copies are continuously made. It can be understood that a stable copy image can be obtained and the durability is excellent because the increase of the blank sheet potential (V _w ) and the increase of the residual potential (V _r ) are small.

[Brief description of drawings]

1, FIG. 2, FIG. 3, and FIG. 4 are sectional views of respective examples of the photoconductor of the present invention. In the drawings, reference numerals 1 ... Conductive support 2 ... Charge generation layer (CGL) 3 ... Charge transport layer (CTL) 4A, 4B, 4D ... Photosensitive layer 5 ... Surface (protective) layer (OCL).

Claims (1)

(57) [Claims] 1. A structural unit represented by the following general formula [I] and / or the following general formula [I] in the surface region on the side provided with a photosensitive layer.
I] containing a polycarbonate having a structural unit represented by the main repeating unit, and the following general formula [II
Ib], wherein the surface region contains a compound having a hindered amine structural unit in the molecule. General formula [I] (However, in this general formula, R ¹ , R ² : a hydrogen atom, a substituted or unsubstituted aliphatic group, a substituted or unsubstituted carbocyclic group, or a substituted or unsubstituted aromatic group, R ¹ And at least one of R ² is a bulky group, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , and R ¹⁰ : a hydrogen atom, a halogen atom, a substituted or unsubstituted aliphatic group, or A substituted or unsubstituted carbocyclic group.) General formula [II] (However, in this general formula, R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , and R ¹⁰ are the same as those described above, Z: a substituted or unsubstituted carbocycle or a substituted or A group of atoms necessary for forming an unsubstituted plural ring.) General formula [III b] (However, in this general formula, R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ : hydrogen atom, substituted or unsubstituted alkyl group, or substituted or unsubstituted aryl group Y ² , Y ³ : hydrogen atom, or organic Residue Z: an atomic group necessary for constituting a substituted or unsubstituted nitrogen-containing ring (excluding compounds having a hindered phenol structural unit at the same time.)