JPH01253752A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance potential characteristics and durability of a photosensitive body and to reduce defects, such as black spots, by incorporating a silicone resin in an electric charge generating layer and a specified polycarbonate in a charge transfer layer. CONSTITUTION:For example, an electric charge generating layer 2 and the charge transfer layer 3 are laminated on a substrate 1 in this order, when needed, with an interlayer 5 interposed between the substrate 1 and the layer 2, and the silicone resin is used for the binder of the layer 2, and the binder to be used for the layer 3 is the polycarbonate having repeating units represented by formulae I and II in which each of R1 and R2 is H, alkyl, or the like; each of R3-R10 is H, halogen, or the like; and Z is an atomic group necessary to form a carbon or hetero ring, and as the unit of formula II, the unit of formula III and the like may be used, and said polycarbonate can be used for the layer 2, optionally together with another resin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic photoreceptor, and more particularly to an organic photoconductive electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor useful for positive charging and reversal development.

[Conventional technology]

In an electrophotographic copying machine using the Carlson method, the surface of the photoreceptor is uniformly charged, the charge is erased imagewise by exposure to form an electrostatic latent image, and the electrostatic latent image is developed with toner. Then, the toner image is transferred and fixed onto paper or the like.

On the other hand, the photoreceptor is subjected to removal of adhered toner, neutralization of static electricity, and surface cleaning, and is used repeatedly over a long period of time.

Therefore, as an electrophotographic photoreceptor, it not only has good charging characteristics and sensitivity, but also has electrophotographic characteristics such as low dark decay.
In addition, it has good physical properties such as printing durability, abrasion resistance, and moisture resistance after repeated use, as well as resistance to ozone generated during corona discharge and ultraviolet rays during exposure (environmental resistance). required.

Conventionally, as electrophotographic photoreceptors, inorganic photoreceptors whose photosensitive layer is mainly composed of inorganic photoconductive substances such as selenium, zinc oxide, and cadmium sulfide have been widely used.

In recent years, carrier generation and carrier transport functions have been assigned to different materials for the photosensitive layer of electrophotographic photoreceptors, and materials that exhibit each function are selected from a wide range according to the desired characteristics, resulting in high sensitivity and durability. There is a trend toward practical use of organic photoreceptors with large sizes.

Conventionally, such functionally divided organic photoreceptors have been mainly used for negative charging, and as described in JP-A No. 60-247647, a thin carrier generation layer is provided on a support.
A relatively thick carrier transport layer is provided on top of this.

As the binder used in the photosensitive layer of the photoreceptor, it is known that bisphenol Z type polycarbonate as shown by the structural formula below exhibits good properties in terms of charging characteristics, sensitivity, residual potential, repeatability, etc. It is being

11□ Furthermore, it is known that an electrophotographic photoreceptor using the above bisphenol 2 type polycarbonate as a binder resin has improved mechanical strength and electrophotographic properties when used as a photoreceptor in an electrophotographic copying machine.

However, on the other hand, when using the photoreceptor as described above,
Carrier injection from the conductive support or lower layer side is likely to occur, resulting in a phenomenon in which the surface charge of a minute portion locally disappears or decreases.

When developing an electrostatic latent image using such a photoreceptor using a regular development method or a reversal development method, an abnormality occurs in toner development in the areas where the surface charge disappears or decreases; This results in an image defect called ``white spots''.

On the other hand, in the reversal development method, that portion is developed with toner, resulting in a so-called fogged image. This type of fog is different from a normal fog, and is a black spot on a white background called a ``black spot.'' It is much more noticeable than a ``white spot,'' in which the black background appears white, and has received a bad reputation as a fatal image defect.

As a countermeasure against black spots, attempts have been made to suppress charge injection from the conductive surface by providing a blocking subbing layer on the conductive surface of the support, and it has been observed that the suppressing effect is proportional to the thickness of the subbing layer. Attempts have been made to adjust the movement of charges by reducing the amount of charge transport material in the charge transport layer, but in any case this results in difficulty in charge movement, resulting in a decrease in sensitivity and an increase in residual potential, resulting in an increase in image density. This results in a decrease in

[Purpose of the invention]

An object of the present invention is to provide a photoreceptor having good potential characteristics.

Another object is to provide a photoreceptor that provides high image quality that can be considered practically free of image defects such as black spots.

[Structure of the invention]

The object of the present invention is to provide an electrophotographic photoreceptor in which a plurality of constituent layers including a charge generation layer and a charge transport layer are laminated on a support, wherein the charge generation layer contains a silicone resin, and the charge transport layer contains a silicone resin. This is achieved by an electrophotographic photoreceptor characterized in that the layer contains at least a polycarbonate having the following formula (BI) and/or (:BI[) in its structural composition as a main repeating unit.

When the silicone resin (organosilicon polymer) according to the present invention is classified according to the type of bone core structure containing silicon, the following types Ca) to (f) can be mentioned.

RRR [:a) (b) (c) RRRR [:d) [e] [f) Polymers having silicon-containing atomic groups as pendant groups are also classified as T.

Among these, the most important organosilicon polymer is of course organoborinoxane type [C], and the majority of commercially available silicone resins are of this type. and is often called silicone.

Commercially available silicones are broadly classified into those with long chain structures and those with complex crosslinked structures. Silicone oil and silicone rubber belong to the former category, and silicone varnish (silicone resin) belongs to the latter.

Silicones are also classified according to the organic groups on silicon, and each type of silicone is methyl silicone (unit structure Me2SI
O), phenyl silicone (unit structure Ph2Sin
, Ph5iOs/z) and H-based silicone (unit structure MeH5iO).

A methyl group or a phenyl group is preferably used as the organic group.

There is also polysiloxane called modified silicone.
Silicone obtained from these materials maintains the original properties of dimethylpolysiloxane, while also having new properties such as heat resistance, oil resistance, water solubility, oil solubility, reactivity, and binderability. I'm a polysexual. There are many possibilities for structural changes in substituents.

Next, specific examples of the silicone resin according to the present invention will be listed from among commercially available products.

: Specific examples of silicone resins: These silicone resins are effective in preventing black spots during reversal development. It also forms a favorable combination with phthalocyanines as a CGM.

The above-mentioned polycarbonates having repeating units represented by formulas (BI) and/or (BI[) in their structural composition are those that have improved the drawbacks of bisphenol Affi carbonates, and are , at least one of them is bulky (pulky) R1
, R2 are bonded to each other, or a ring is formed by the above-mentioned Z, so that these R1 and/or R2 or Z effectively prevent the molecular chains of the polycarbonate from arranging in a specific direction. This prevents the polycarbonate from crystallizing, causing the solution to gel, or precipitating on the film surface during the formation of the photosensitive layer, thereby preventing property deterioration, such as a decrease in yield due to abnormal convexities and image defects due to poor cleaning. Can be done. Such a remarkable effect will be even more pronounced if R1 and R2 in the above-mentioned formula (BI) are different from each other or are bonded asymmetrically. In the formula (-B II ), the ring formed by 2 directly contributes to the above remarkable effect.

That is, in the present invention, by using the polycarbonate represented by the above-mentioned formula (BI) or general formula (B[) as the binder resin, the film has excellent physical properties, charge retention ability,
It is possible to produce an electrophotographic photoreceptor that has excellent electrophotographic properties such as sensitivity residual potential and exhibits stable properties with little fatigue deterioration even when subjected to repeated use.

Furthermore, when used as a photoreceptor, the surface of the photosensitive layer is less likely to be scratched even when rubbed by a magnetic brush or cleaning blade, and the photosensitive layer has less abrasion, and it has a high printing durability without defective properties such as poor cleaning. A photoreceptor can be created.

Also, the polycarbonate resin according to the present invention may optionally contain - a copolycondensation type polycarbonate containing other repeating units in addition to the repeating units of formulas (BI) and (Bll), such as 4.4 '-dihydroxyphenyl-
Physical,
Chemical or electrical properties may also be adjusted.

Furthermore, if necessary, other polymers may be mixed and used within a range that does not interfere with the intended effects. The mixing ratio at this time is preferably 50 ft/% or less.

The polycarbonate resin according to the present invention has excellent compatibility with CTM, and since the binder used in the present invention is polycarbonate-based, it does not have the excellent charging performance, repeatability, printing durability, etc. that polycarbonate inherently exhibits. properties can be imparted to the photoreceptor.

Among the polycarbonates used in the present invention, general formula C
In the case of Bl ), it is essential that at least one of R1 and R2 is a bulky group, but it is desirable that such a bulky group has 3 or more carbon atoms, and the molecular chain It acts as a steric hindrance to prevent orientation. Examples of such bulky groups include the following:
an alkyl ester group represented by p≧l);

(3) cq)1. ,. Alkyl group represented by 1 (
However, q≧3) (4) ÷ CH,% C0OR+4 an alkyl ester group (however, R14 is an alkyl group, r≧2) Also, if one of R, R2 is a bulky group, the other is hydrogen It may be an atom or an alkyl group such as a methyl group.

Next, R1 in the above formula (BI), (B II)
The group ~RIG may be a hydrogen atom, a halogen atom, an alkyl group such as a methyl group, or a carbocyclic group such as a cyclohexyl group.

Further, in the polycarbonate of formula CBn], Z may form a 5- or 6-membered carbocyclic ring or a heterocyclic ring, and examples of such a ring include a cyclohexyl ring, a cyclopentyl ring, etc. A substituent such as an acetyl group or an acetylamino group may be introduced into a part of the ring.

Specifically, the repeating units of the polycarbonate used in the present invention include the following.

Example repeat unit: (Bl-1) (CHHz)z CH.

(BI-2) (BI-3) (Bl-4) (BI-5) (BI-6) ■ CH3 (Bl-7) CH.

CH, -CH-CH.

(Bl-8) LL (B l-11) (B I -12) (Bl-13) coocaos (I3 1 -14) Q Exemplary repeating unit: (Bn-1) II CH, -CI+□ (B■- 2) (Bll-3) (CH2)II (Bll-4) ShiH3 (Bll-5) (B ■ -6) (B ■ -7) (BII-8) (BII-9) In addition, in the present invention The polycarbonate used is the main component of the binder, but other binder components that may be used in combination include ordinary polycarbonate, the above R1, R2,
Examples include polycarbonate that does not have z.

The above-mentioned polycarbonate is used as a binder for a photosensitive layer (especially CTL of a functionally separated photoreceptor, or both CTL and CGL).

Examples of binders that may be used in CGL and CTL in combination with the polycarbonate used as the binder described above include the following.

(1) Polyester (2) Methacrylic resin (3) Acrylic resin (4) Polyvinyl chloride (5) Polyvinylidene chloride (6) Polystyrene (7) Polyvinyl acetate (8) Styrene copolymer resin (for example, styrene-butadiene copolymer styrene-methyl methacrylate copolymer, etc.) (9) Acrylonitrile copolymer resin (e.g., vinylidene chloride-acrytronitrile copolymer, etc.) (10) Vinyl chloride-vinyl acetate copolymer (11) )
Vinyl chloride-vinyl acetate-maleic anhydride copolymer (12) Silicone resin (13) Silicone-alkyd resin (14) Phenol resin (e.g. phenol-
Formaldehyde resin, cresol formaldehyde resin, etc.) (15) Styrene-alkyd resin (16) Poly-
N-Vinylcarbazole (17) Polyvinyl butyral (18) Polyvinyl formal (19) Polyhydroxystyrene These binders can be used alone or in combination in the carbonate of the present invention as a mixture of two or more.

Next, as the charge generating substance (hereinafter referred to as CGM) used in the present invention, any inorganic pigment or organic pigment can be used as long as it absorbs electromagnetic waves and generates free carriers. For example, amorphous selenium, trigonal selenium, selenium-arsenic alloy, selenium-tellurium alloy, cadmium sulfide,
In addition to inorganic pigments such as cadmium selenide, cadmium selenide sulfide, mercury sulfide, lead sulfide, lead oxide, zinc oxide, and titanium oxide, organic pigments such as those shown in the following representative examples can be used.

(1) Azo pigments such as monoazo pigments, polyazo pigments, metal complex azo pigments, pyrazolone azo pigments, stilbene azo and thiazole azo pigments (2) Perylene pigments such as perylenic anhydride and perylenic acid imide (3) Anthraquinone derivatives , ananthanthrone derivatives, dibenzpyrenequinone derivatives, pyranthrone derivatives,
Anthraquinone or polycyclic quinone pigments such as violanthrone derivatives and inviolanthrone derivatives (4) Indigoid pigments such as indigo derivatives and thioindigo derivatives (5) Phthalocyanine pigments such as metal phthalocyanines and metal-free phthalocyanines (6) Diphenylmethane pigments , carbonium pigments such as triphenylmethane pigments, xanthine pigments and acridine pigments (7) quinone imine pigments such as azine pigments, oxazine pigments and thiazine pigments (8) methine pigments such as cyanine pigments and azomethine pigments (9) quinoline pigments Pigments (lO) Nitro pigments (ll) Nitroso pigments (12) Benzoquinone and naphthoquinone pigments (13)
) Naphthalimide pigments (14) Perinone pigments such as bisbenzimidazole derivatives For a complete list of preferred specific compounds of the azo pigments used in the present invention, see Japanese Patent Application No. 195881/1983.

Moreover, polycyclic quinone pigments can be most preferably used as CGM.

In addition, as CGM for positive charging, various phthalocyanines such as r-type or l-type metal-free phthalocyanine, a-type titanyl 7-thalocyanine (JP-A No. 49-4338, No. 58-182639, No. 61-109056, No. 6
No. 1-239248, etc.) are preferably used.

Next, the charge transport material (hereinafter referred to as CTM) that can be used in the present invention is not particularly limited, but includes, for example, oxazole derivatives, oxadiazole derivatives, thiazole derivatives,
Thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidacilone derivatives, imidazolidine derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds, pyrazoline derivatives, oxacilone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives,
It may be poly-N-vinylcarbazole, poly-1-vinylpyrene, poly-9-vinylanthracene, etc.

However, it is preferable to use a CTM that has an excellent ability to transport holes generated during light irradiation to the support side and is suitable for combination with the CGM, such as a styryl compound. For the complete details of each specific styryl compound, see Japanese Patent Application No. 1987-195.
Reference is made to No. 881.

Moreover, amine derivatives can also be used as CTM.

For details, refer to Japanese Patent Application No. 195881/1981.

The photosensitive layer structure of the photoreceptor of the present invention preferably has a laminated structure, but
A protective layer (OCL) provided as a surface layer if necessary, and at least one layer of CTL, CGL, or intermediate layer, or multiple layers thereof, for the purpose of improving sensitivity, reducing residual potential or fatigue during repeated use, etc. It is possible to contain a species of electron-accepting substance.

Electron-accepting substances that can be used in the photoreceptor of the present invention include:
For example, succinic anhydride, maleic anhydride, dibromaleic anhydride, phthalic anhydride, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, 3-nitrophthalic anhydride, 4
-ditrophthalic anhydride, pyromellitic anhydride, mellitic anhydride, tetracyanoethylene, tetracyanoquinodimethane, 0-dinitrobenzene, -dinitrobenzene, 1
．． 3.5-trinitrobenzene, varanitrobenzonitrile, vicryl chloride, quinone chlorimide, chloranil, brumanil, 2-methylnaphthoquinone, dichlorodicyanobarabenzoquinone, anthraquinone, dinitroanthraquinone, trinitrofluorenone, 9-fluorenonedene (dicyano methylenemalonodinitrile)
, polynitro-9-fluorenylidene-(dicyanomethylenemalonodinitrile), pitalic acid, 0-nitrobenzoic acid, p-nitrobenzoic acid, 3.5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3
．． Examples include 5-dinitrosalicylic acid and 7-talic acid.

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

Furthermore, ultraviolet absorbers, antioxidants, etc. may be used.

Preferred ultraviolet absorbers include nitrogen-containing compounds such as benzoic acid, stilbene compounds and derivatives thereof, triazole compounds, imidazole compounds, triazine compounds, coumarin compounds, oxadiazole compounds, thiazole compounds and derivatives thereof.

Examples of the antioxidant include hindered phenol, hindered amine, paraphenylene diamine, aryl alkane, hydroquinone, spirochroman, spiroindanone and derivatives thereof, organic sulfur compounds, organic phosphorus compounds, and the like.

These specific compounds are disclosed in Japanese Patent Application No. 61-1628.
No. 66, No. 61-188975, No. 61195878
No. 61-157644, No. 61-195879, No. 61-162867, No. 61-204469,
It is described in No. 61-217493, No. 61-217492, and No. 61-221541.

Further, the UCL according to the present invention may contain less than 50% by weight of a thermoplastic resin, if necessary, for the purpose of improving processability and physical properties (preventing cracks, imparting flexibility, etc.).

Further, the intermediate layer functions as an adhesive layer or a blocking 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 copolymer, etc. Maleic anhydride copolymer, casein, N-alkoxymethylated nylon, starch, etc. are used.

As the conductive support used in the construction of the electrophotographic photoreceptor of the present invention, the following are mainly used, but the support is not limited thereto.

1) Metal plates such as aluminum plates and stainless steel plates.

2) A thin layer of metal such as aluminum, palladium, or gold is provided on a support such as paper or plastic film by lamination or vapor deposition.

3) A layer of a conductive compound such as a conductive polymer, indium oxide, or tin oxide is provided on a support such as paper or plasti/kufilm by coating or vapor deposition.

The photoreceptor of the present invention is made of a laminate of CGL2 containing CGM as a main component and CTL3 containing CTl1l as a main component on a conductive support l, as shown in FIGS. 1 and 2. A photosensitive layer 4 is provided. Figures 3 and 4
As shown in the figure, this photosensitive layer 4 may be provided via an intermediate layer (UCL) 5 provided on a conductive support l. When the photosensitive layer 4 has a two-layer structure in this manner, an electrophotographic photoreceptor having the best electrophotographic properties can be obtained. Maj;
In the present invention, as shown in FIGS. 5 and 6, fine particulate CGM 7 is contained in the layer 6 mainly composed of CTM.
A photosensitive layer 4 having a dispersion of the above may be provided directly on the conductive support l or via an intermediate layer 5.

Furthermore, a protective layer 8 may be provided on the photosensitive layer 4 if necessary.

Here, when the photosensitive layer 4 has a two-layer structure, CGL 2 and C
Which of TL 3 is to be used as the upper layer is determined depending on whether the charging polarity is positive or negative. That is, when forming a negatively charged photosensitive layer, it is advantageous to use CTL 3 as an upper layer, since CTM in CTL 3 is a substance having a high transport ability for holes.

The CGL 2 constituting the photosensitive layer 4 having a two-layer structure can be applied directly onto the conductive support 1 or CTL 3 or by providing an intermediate layer such as an adhesive layer or a blocking layer as necessary, by the following method. can be formed.

(1) Vacuum deposition method (2) Method of applying a solution of CGM dissolved in a suitable solvent (3) Forming CGM into fine particles in a dispersion medium using a ball mill, sand grinder, etc. and mixing and dispersing with a binder as necessary A method of applying the resulting dispersion.

That is, specifically, a vapor deposition method such as vacuum evaporation, sputtering, or CVD, or a coating method such as dipping, spray, blade, or roll method may be arbitrarily used.

The thickness of CGL2 formed in this way is 0.01
It is preferably from μm to 5 μm, more preferably 0
．． 05 μffl to 3 μm.

Further, the thickness of the CTL 3 may be changed as necessary, but it is usually preferably 5 μm to 30 μm. This CTL
The composition ratio in No. 3 is preferably 0.1 to 5 parts by weight of Bisita to 1 part by weight of CTM of the present invention.
When forming the photosensitive layer 4 in which particulate CGM is dispersed, it is preferable to use the binder in an amount of 5 parts by weight or less per 1 part by weight of CGIII.

Further, when the CGL is configured as a dispersed type in a binder, it is preferable to use the binder in an amount of 5 parts by weight or less per 1 part by weight of the CGM.

The photoreceptor of the present invention has the above-described structure, and as is clear from the examples described later, it has excellent charging characteristics, sensitivity characteristics, and image forming characteristics by normal and reversal development. In particular, it exhibits excellent durability with little fatigue deterioration even when subjected to repeated transfers.

(Examples) Examples of the present invention will be specifically described below, but the embodiments of the present invention are not limited thereto.

Production of Photoconductors> Photoconductors AP of the present invention and photoconductors ah for comparison were produced in the following manner. That is, the manufacturing procedure for each photoreceptor is common.

First, on a conductive support made of polyethylene terephthalate with a thickness of about 75 μm on which aluminum has been vapor-deposited, a coating liquid for UCL in which a predetermined binder substance is dissolved is applied using a doctor blade, and an undercoating having a predetermined film thickness is applied. layer (UC
L) was formed. However, for the photoreceptor without uCL, CGL was formed directly on the conductive support.

Next, 20g of the specified CGM was heated at 40rpm using a magnetic pole.
After grinding for 18 hours, a solution of a predetermined amount of binder dissolved in 1,2-dichloroethane was added and dispersed for an additional 24 hours to achieve a predetermined P/B ratio (ratio of content of CGM to binder material). A CGL coating liquid having a predetermined film thickness is prepared, and this liquid is applied onto the opening Ct (or the conductive support) using a doctor blade.
L was formed.

Further, a solution obtained by dissolving a predetermined CTM and 20 g of a predetermined binder substance in 100 mQ of 1,2-dichloroethane is applied onto the CGL using a doctor blade,
CTL was formed by drying at a temperature of 80°C for 1 hour.

CGM, the binder used in the Examples and Comparative Examples.

The CTM is as follows.

[UCL] ■ Vinyl chloride-vinyl acetate-maleic anhydride copolymer "S-LEC MF-104 (manufactured by Tsukimizu Kagaku Kogyo Co., Ltd.) approx. 0.
1 μm ■ Polyester resin "Vylon 200" (manufactured by Toyobo Co., Ltd.) approximately 0.1 p m ■ // Approximately 21 [CGM] ■ α-type metal-free phthalocyanine compound (Monorado Fast Pull CS manufactured by ICI) was heated three times with dimethyl formaldehyde. Extracted and purified. Through this operation, the purified product was transferred to the β form. Next, a portion of this β-type metal-free phthalocyanine compound was dissolved in concentrated sulfuric acid, and this solution was poured into ice water to cause reprecipitation, thereby transforming it into the α-type. This reprecipitate was washed with aqueous ammonia, methanol, etc., and then dried at 10°C. Next, the α-type metal-free phthalocyanine compound purified above was placed in a sand mill together with a grinding aid and a dispersant, and kneaded at a temperature of 100±20'O for 25 hours. By this operation, after confirming that the crystal form has transitioned to β type, take it out from the container, thoroughly remove the grinding aid and dispersant with water and methanol, etc., and dry it, giving it a clear blue tinge. Blue crystals of a τ-type metal-free 7-lysocyanine compound were obtained.

τ-type metal-free phthalocyanine compound [CGL binder] obtained as above [rKR-5240J (manufactured by Shin-Etsu Chemical Co., Ltd.)]■
rES-1001NJ (/I) Silicone resin ■ Polycarbonate resin [Panlite L-1250
J (manufactured by Ondai Kasei Co., Ltd.) [Phase] Acrylic resin [Dyanal BR-80J (manufactured by Mitsubishi Rayon Co., Ltd.) ■ Polyester resin "Vylon 300" (manufactured by Toyobo Co., Ltd.) ◎ Poly P-vinylphenol "Maruka Linker M"
(Manufactured by Marukubi Petrochemical Co., Ltd.) (CTM) [Phase] C2H.

[Phase] CCTL binder] (21) Polycarbonate resin "Nipilon Z-200" whose repeating units are the structural units shown in (BI[-2)]
J (manufactured by Mitsubishi Gas Chemical Co., Ltd.) (22) Polycarbonate resin whose repeating unit is the structural unit shown in (Bl-10) (viscosity average molecular weight 30.0
00) Also, the combination of specifications applied to UCL, CGL, and CTL was evaluated. A total of 2 photoconductors A-P of the present invention and photoconductors a-h for comparison.
rKonica U-Bix15, which has a semiconductor laser light source with a wavelength of 780±lpm for each of the four types of photoreceptors
Installed on a 50MRJ (manufactured by Konica) modified machine, the potential was measured in a high temperature, high humidity environment (30°C, 980% RH, H, )l) and a low temperature, low humidity environment (10'c, 20% RH, L, L). Measurements were made (VH and VL). Note that VH is the potential of the laser-unexposed area, and VL is the potential of the laser-exposed area.

Next, under normal temperature and normal humidity environment (20°C, 50% RH),
VH=600±10 (-V
), and reverse development was carried out at a developing bias of -490 (V) to obtain I; black spots on the white background portion of the copied image were evaluated. For the evaluation of black spots, the particle size and number of black spots were measured using an image analysis device "Omnicon 3000" (manufactured by Shimadzu Corporation), and the I(
Diameter) 0-05mm or larger black spot 1 per 1 cm
If there is one or more, mark it as ×, and if there are 10 or less, mark as ○.

Table 2 shows the potential measurement results and dark spot evaluation results for each photoreceptor.

Table 2 H, H, L, L.

Photoreceptor VH [knee V:l VL (-V) VH[
Knee V'3VL [-V) Black point A 620 20 6
40 30 0 B 640 15 650 20 0 Actual C64020650250 D 630 20 650 30 0 E 620 15 640 20 0 F 650 10 670 15 0 Actual G 630 15 64
0 25 0H62015640200 J 640 5 650 10 0 Example K 580 10 60
0 15 0L 570 5 590
10 0 M 580 10 600 15 ON 560 2
0 580 25 0 p 570 20 580 25 0 a 630 30 660 40 X ratio b
580 60 620 1
20 xc 650 90 680 160
x comparison d 600 250
660 380 Xe 660 80
690 140 X example r 720
200 780 320 0g
660150 700 3600 h 650 70 700 180 do.

(2) Comparative Examples A, C, and D: Since a binder other than that specified in the present invention was used, black spots were produced and the sensitivity was also poor.

(3) Comparative Examples e and f Due to the installation of Ni-blocking UCL, the sensitivity was lowered, and f was acceptable for black spots, but e was rated x due to insufficient film thickness.

(4) Comparative Examples g and h: Sensitivity decreased due to lack of CTM, especially at L, L, and lower. Regarding black pochi, g is allowed, but h is not.

Compared to the above comparative examples, the examples according to the present invention are better in sensitivity and black spots.

[Brief explanation of the drawing]

1 to 6 are sectional views showing examples of the mechanical structure of the electrophotographic photoreceptor of the present invention, respectively.

Claims (1)

[Scope of Claims] An electrophotographic photoreceptor in which a plurality of constituent layers including a charge generation layer and a charge transport layer are laminated on a support, the charge generation layer containing a silicone resin and at least the charge transport layer. has the following general formula [B I] and/or [
An electrophotographic photoreceptor comprising a polycarbonate having a structural composition of BII]. General formula [B I] ▲ Numerical formulas, chemical formulas, tables, etc. are available▼ [However, in the formula, R_1 and R_2 are hydrogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted cycloalkyl groups, or substituted or unsubstituted aryl groups. a group R_1 or R_2
At least one of them is a bulky group. R_3, R_4, R_5, R_6, R_7, R_8, R
_9, R_1_0 is a hydrogen atom, a halogen atom, a substitution,
It represents an unsubstituted alkyl group or a substituted or unsubstituted cycloalkyl group, and has a degree of polymerization of 10 to 5,000, preferably 50 to 100. ] General formula [BII] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [However, in the formula, R_3, R_4, R_5, R_6, R_7
, R_8, R_9, R_1_0 are represented by the general formula [B I
], Z represents an atomic group necessary to form a substituted or unsubstituted carbocycle or a substituted or unsubstituted heterocycle, and the degree of polymerization is 10 to 5000, preferably 50
~1000. ]