JPH04195061A - Photosensitive body - Google Patents

Abstract

PURPOSE:To obtain the photosensitive body restrained from image defects, such as black spots, and sufficient in sensitivity to comparatively long wavelength light, such as semiconductor laser beams, by forming an undercoat layer made of a polyether type radiation-curing resin on a conductive substrate. CONSTITUTION:The photosensitive body is formed by laminating at least the undercoat layer (UCL) 7 and a photosensitive layer (PCL) 8 on the conductive substrate 1, and the undercoat layer 7 is made of the polyether type radiation- curing resin having at least one of radiation-sensitive unsaturated acrylic double bond, allyl type double bond, and maleic acid type double bond on the side chain and/or the end of the polymer chain, thus permitting a barrier against local injection of carriers from the side of substrate 1 to be formed, and the loss or decrease of surface charge due to the local carrier injection to be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a photoreceptor, particularly an electrophotographic photoreceptor.

[Background of the invention]

In the Carlson electrophotographic copying method, after the surface of the photoreceptor is charged, an electrostatic latent image is formed by exposure, the electrostatic latent image is developed with toner, and then the visible image is transferred to paper or the like. Transfer and fix. At the same time, the photoreceptor is subjected to removal of adhering toner, neutralization of static electricity, and surface cleaning, and is used repeatedly over a long period of time.

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

Conventionally, inorganic photoreceptors having a photoreceptor layer containing an inorganic photoconductive substance such as selenium, zinc oxide, or cadmium sulfide as a main component have been widely used as electrophotographic photoreceptors.

On the other hand, in recent years, active research and development has been carried out on the use of various electroconductive materials as materials for photoreceptor layers of electrophotographic photoreceptors.

However, sensitivity and durability are not necessarily satisfactory.

For this purpose, in the photosensitive layer, the carrier generation function and the carrier transport function are assigned to different substances, thereby creating a so-called functionally separated type organic photoreceptor with high sensitivity and durability, in which each functional layer is laminated. Attempts are being made to develop.

In such functionally separated electrophotographic photoreceptors, substances that exhibit each function can be selected from a wide range of materials, so it is relatively easy to produce an electrophotographic photoreceptor with arbitrary characteristics. is possible. Therefore, it is expected that an organic photoreceptor with high sensitivity and durability will be obtained.

FIGS. 2 and 4 show a function-separated type laminated electrophotographic photoreceptor using such an organic photoconductive substance.

FIG. 3 shows a functionally separated single-layer electrophotographic photoreceptor.

The electrophotographic photoreceptor shown in FIG. 2 is constructed by sequentially laminating an undercoat layer (UCL) 7, a carrier generation layer (CGL) 6, and a carrier transport layer (CTL) 4 on a conductive support l. It is used for negative charging. That is,
The photosensitive layer (PCL) 8 is composed of CGL 6 and CTL 4.

In an electrophotographic photoreceptor having such a layer structure,
In the case of negative chargeability, the mobility of holes is greater than that of electrons, so a photoconductive material having good hole transport properties can be used, which is advantageous in terms of photosensitivity and the like.

Next, FIG. 4 shows a photoreceptor for positive charging. In photoconductors using such laminated layers, especially photoconductors using organic photoconductive materials, non-uniform carrier (hole) injection from the conductive support or lower layer side tends to occur when negatively charged, and this causes surface charge to increase. Microscopically, it disappears or decreases. This results in image defects in the form of black spots (black spots), particularly in the reversal development method, which significantly reduces the quality of the image.

This problem of black spots is a phenomenon peculiar to photoreceptors using organic photoconductive materials with high hole mobility, and the cause of this problem is thought to be the non-uniform carrier injection described above.

Therefore, it has been proposed to provide a UCL between the conductive support 1 and the PCL to block carrier injection.

Conventionally, materials constituting UCL7 include polyester, polyurethane, polyamide, epoxy resin,
Polycarbonate-based materials, vinyl polymer-based materials such as polyvinylpyridine acrylic resins, cellulose-based materials, polyketal-based materials, and condensation polymer systems such as phenolic resins and melamine resins are known.

However, the above-mentioned known undercoat layer does not have a sufficient effect of suppressing black spots. Moreover, it has not been achieved to improve both the blocking property and the sensitivity as a photoreceptor. In other words, among the resins conventionally used, those that have effective blocking properties and are thought to have the effect of suppressing black spots have poor sensitivity, and conversely, when trying to improve sensitivity, the blocking properties are insufficient and black spots appear. cannot be suppressed sufficiently.

Additionally, problems arise during the multilayer coating process. If the solubility of the polymers in the upper and lower layers is similar, part of the lower layer will dissolve when the upper layer is applied, and the interface between the upper and lower layers will be disturbed and coating will not be possible, or if coating is done by dipping, the upper layer coating tank will be This not only shortens the life of the expensive upper layer coating solution but also deteriorates the potential characteristics of the photoreceptor due to contamination with the constituent components of the lower layer.

These factors impose strict prescription restrictions on the polymers and solvents in the upper and lower layers.

There are examples of thermosetting resins being applied to UCL, but they require high curing temperatures (at least IIO'C or higher) and relatively long times (
30 minutes or more), which reduces productivity. or,
The stability of a coating solution mixed with a curing agent is essentially impaired.

Furthermore, the adhesion is still insufficient, and the adhesiveness between the support and U, C
At present, in addition to the adhesion with L, the adhesion between UCL and the upper layer is poor.

Furthermore, in recent years, semiconductor laser light sources have been used in electrophotographic copying methods, which are inexpensive, compact, and capable of direct modulation. Currently, gallium-aluminum-arsenic (Ga-AI) is widely used in semiconductor lasers.
-As) type light emitting element has an oscillation wavelength of about 750 nm or more.

Although such a technical system using a laser beam or the like is expected to be applied to printers, at present no photoreceptor having high sensitivity to long wavelength light has been developed.

[Purpose of the invention]

An object of the present invention is to provide a photoreceptor that can suppress image defects such as black spots and has sufficient sensitivity to relatively long wavelength light from semiconductor lasers and the like.

Another object of the present invention is to provide a photoreceptor with excellent printing durability, potential stability, and residual potential characteristics.

Another object of the present invention is to provide a photoreceptor having good coating properties and adhesion properties, in which at least UCL and PCL are provided on a conductive support.

[Structure of the invention and its effects]

The photoreceptor of the present invention includes: (1) A photoreceptor in which at least a subbing layer and a photosensitive layer are provided on a conductive support, wherein the subbing layer is formed of a polyether radiation-curable resin. It is composed of the following characteristics.

In an embodiment of the present invention: (2) The polyether radiation-curable resin contains at least one of radiation-sensitive unsaturated double bonds, such as an acrylic double bond, an allyl double bond, and a maleic acid double bond. It is preferable to have one type in the side chain and/or the terminal.

By adopting the configuration of the present invention, 1. good multilayer coating properties, 2. no contamination of other coating solutions, and 3. not being dissolved by other coating solutions, giving a wider range of formulation options. The following advantages are obtained: 4. Good blocking properties and no appearance of black spots; 5. Good adhesion to the lower layer.

As mentioned above, this polymer has a blocking function that effectively prevents uneven injection of holes from the support, which tends to occur when organic photoconductive materials with high hole mobility are used in PCL. have.

Therefore, the presence of this UCL can provide a barrier to local carrier injection from the support side,
It is thought that it is possible to prevent the surface charge from disappearing or decreasing due to local carrier injection. Therefore, especially when reversal development is performed, there are no black spots on the image, no white spots, no rough edges, no pinholes, and a remarkable effect of obtaining a high-quality image without image defects. can play.

The radiation-sensitive polyether polymer used in the present invention contains at least one of an acrylic double bond, an allylic double bond, and a maleic acid double bond in the side chain and/or terminal of the polyether polymer. .

Polyether polymers include aliphatic polyethers, aromatic polyethers, alicyclic polyethers, cyclic polyethers, etc. An example of a case where there are acrylic double bonds at both ends is shown in the following general formula. It becomes like this.

(i) (R1-〇+R,- (Ll) (R1o+ (iv) (v) (vl) Rl+ Rs; Cl-C+. The number of carbon atoms in R1 and R1 is They may be the same or different.

Further, R1 and R+ may contain a functional group such as a -0H group or an ester group, and the ratio may be 1/1.

R2; Cl-C6 alkyl group m, n; positive number of 1 or more Examples of compounds having other unsaturated bonds such as allyl type or maleic acid type include: 1, 09 HO4CH2CH20 6-CH-C)I -ε-O-(
CH2CH2qHm:n-l m=1 n=2 3゜m:n-1 m-5n=5 When using the compound of the present invention, a photopolymerization initiator is added to increase the UV absorption rate and curing speed. Good too. Examples include benzoin ethers, benzyl ketals, α-hydroxyacetophenones, chloracetophenones, σ-aminoacetophenones, acylphosphine oxides, α-dicarbonyls, σ-anruoquine esters, etc. be.

The radiation used includes ultraviolet rays, electron beams, X-rays, and gamma rays, but ultraviolet rays and electron beams are preferred.

Curing by ultraviolet irradiation is carried out by irradiating ultraviolet rays with a wavelength of about 2,000 to 4,000. A mercury lamp with an output of about 50 to 100 W/cm is suitable for the ultraviolet generator. Electron beam heat, radiation acceleration voltage 100-750
It is carried out using an electron beam accelerator of KV, preferably 150 to 300 KV, so that the absorbed dose is 2 to 20 Mrad.

There is no major difference in prescription between the use of ultraviolet rays and the case of electron beams, except that when ultraviolet rays are used, a photopolymerization initiator may be required.

The UCL in the present invention has a thin film thickness of 2 μm or less, so that it can sufficiently exhibit blocking performance, and
This is desirable in terms of maintaining good photoreceptor performance such as suppression of residual potential. More preferably, it is 0.2 to 1.0 μm.

The photoreceptor of the present invention has the structure shown in FIG. 2, for example.

In this photoreceptor, on a conductive support (substrate) l,
CGL6 is provided via the above-described UCL7, and this CGL6 is provided via the above-mentioned UCL7.
GL6 upper t:, CT L4 is provided. 8 indicates PCL. Therefore, U between CGL6 and support 1
Since CL7 is provided, it is possible to effectively prevent non-uniform injection of holes from the support side as shown in Fig. 8, and at the same time, it is possible to efficiently transport electrons, which are photocarriers, to the support side during light irradiation. .

Note that the photoreceptor of the present invention has the above-described structure (i.e., CGL
As shown in FIG. 3, it may be made of a single layer of PCL 8 in which a carrier generating material (CGM) and a carrier transporting material (CTM) are mixed. or,
As shown in FIG. 4, the layer structure may be such that the CGL 6 and CTL 4 are upside down (for positive charging). In addition, in the photoreceptor of the present invention, a protective layer (
A protective layer (○CL) may be formed, for example, a synthetic resin film may be coated.

Next, CGM used in the photoreceptor of the present invention is shown by a general formula.

1. Polycyclic quinone pigment (1) Antoanthrone pigment General formula (Gl: (2) Dibenzpyrenequinone pigment General formula CG2): (3) Pyranthrone pigment General formula (G3).

In the above, X: halogen atom, nitro group, cyano group, acyl group, or carboxyl group.

n==0-4 m=0-6 2.7 Zulenium Compound The azulenium compound is, for example, a compound described in the following publication.

(a) JP 61-1547 (b) JP 61-1548 (c) JP 61-15147 (d) JP 61-15150 (e) JP 61-15151 Specific examples of azulenium compounds include the following general formula. Things can be mentioned.

General formula (G4): However, in the above general formula, R eyes, R+2, R13, R11, RIs, Rl&, R1
7: Represents a hydrogen atom, a halogen atom, or an organic residue. In addition, any one combination of R" and RI2, R12 and R13, R13 and R", R's and R16, R16 and R16, Hli and RI7 forms a substituted or unsubstituted condensed ring. Also good.

Ar', Ar'' represents a nialyl group.

RIM, R19: Substituted or unsubstituted three types of groups;
Represents an alkyl group, an aryl group, or an aralkyl group. Also, R
ea and R'' may form a ring together with the nitrogen atom.

L (1, represents an anionic residue.

Typical specific examples of such azulenium salts include the following.

3. N'anine dye N'anine dye is known, for example, disclosed in Japanese Patent Application Laid-Open No. 58-118.
651, M 58-224354, M 59-1460
There is a compound described in No. 6.

4. Phthalonanine Compound Phthalocyanine compounds, which are one of the organic photoconductive materials, are known to have a photosensitive range extended to longer wavelengths than other compounds. In the process of converting α-type phthalonanine compounds into stable crystalline β-type phthalocyanine compounds, various crystalline forms of 7-lycyanine compounds have been discovered. These phthalo/anine compounds exhibiting photoconductivity include, for example, X-type metal-free phthalocyanine compounds described in Japanese Patent Publication No. 49-4338, Japanese Patent Application Laid-open No. 18263-1987,
9, τ, r' described in No. 60-19151
, η, η′ type gold metal phthalocyanine compounds JP-A-63
In addition to the phthalocyanine compounds described in No. i48269, various metal 7-thalocyanine compounds are exemplified.

For example, a patent application was filed in 1983 regarding titalphthalocyanine compounds.
There is one described in No.-241938. In addition, phthalocyanine compounds particularly suitable for semiconductor lasers are exemplified.

Phthalocyanine Exemplary Compound 5 Azo Compound Examples of the disazo compound include those shown in the general formula below.

General formula (G6): %Formula% In addition, as other azo compounds, there are those shown in the following general formulas.

General formula (G7:l: Cp N-N-AS-N=N-Ar'-N=N-cp large, 5 N=N-cp General formula [:G8): % formula % General formula [G9): Cp-N = N-Ar''-N = N-Ar'-N
-N-Ar'-N = N -CpHowever, Ar", Ar
', Ar' represent the following two types of groups, each substituted or unsubstituted: a carbocyclic aromatic ring group and a heterocyclic aromatic ring group.

Furthermore, specific examples of Ar3, Ar', and Ar' are given below:
Furthermore, examples of Cp (coupler) include the following.

However, as for A, in CGL, the content ratio of CGM to the binder substance is preferably 5/l - 1/10, and preferably 3/1 to 3/1 to 1/10.
It is more preferable to set it to 1/3.

When the content ratio of CGM is larger than the above range, black spots etc. tend to appear. However, if the proportion of CGM is too small, the photosensitivity etc. will actually decrease.

The thickness of the CGL is preferably 0.1-10 μm or more, more preferably 0.2-5 μm. The thickness of the CTL is preferably 10 μm or more.

The thickness of the entire photosensitive layer is preferably within the range of 10 to 40 μm, and more preferably within the range of 15 to 30 μm. If the film thickness is smaller than the above range, the charging potential will be low due to the thinness, and the printing durability will also tend to decrease.

Furthermore, if the film thickness is larger than the above range, the residual potential will increase on the contrary, and as in the case where the CGL is too thick, carriers will be caught at trap sites during movement, making it difficult to obtain sufficient transport performance. Therefore, the residual potential tends to increase during repeated use.

It is also possible to include CTM in CGL.

When dispersing granular CGM to form PC'L, the CGM is preferably in the form of powder having an average particle size of 2 μm or less, preferably 1 μm or less, and more preferably 0.5 μm or less.

Further, in the carrier transport layer, it is preferable that the carrier transport substance has excellent compatibility with the binder substance.

As a result, turbidity and opacity do not occur even if the amount of the binder substance is increased, so the mixing ratio with the binder substance can be set at a very wide range. The layer is uniform and stable, resulting in better sensitivity and charging characteristics, and a photoreceptor that can form clear images with higher sensitivity can be used.

Furthermore, especially when used in repeated transfer type electrophotography, it is possible to achieve the effect that fatigue deterioration is less likely to occur.

CTMs that can be used in the present invention include carbazole conductors, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidacilone derivatives, imidazolidine derivatives, bisimidazolidine derivatives, styryl compounds, and hydrazone compounds. , pyrazoline derivatives, oxacilone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives,
One or more selected from acridine derivatives, 7-ninazine derivatives, aminostilbene derivatives, triarylamine derivatives, phenylenediamine derivatives, stilbene derivatives, poly-N-vinylcarbazole, poly-1-vinylpyrene, poly-9-vinylanthracene, etc. There may be two or more types.

Specific examples of such carrier transport substances are disclosed in JP-A-63
-50851.

The general formula is listed below.

The following general formula (Tl) or [T2
] styryl compounds can be used.

General formula (Tl): However, in this general formula, R21, R22: substituted or unsubstituted or two types of groups; represent an alkyl group, an aryl group, and the substituents include an alkyl group, an alkokene group, a substituted amine group, and a hydroxyl group. , a halogen atom, and an aryl group are used.

Ar", Ar": represents a substituted or unsubstituted aryl group, and an alkyl group, an alkoxy group, a substituted amino group, a hydroxyl group, a halogen atom, or an aryl group is used as a substituent.

R23, R21: Represents a substituted or unsubstituted aryl group or hydrogen atom, and as a substituent, an alkyl group, an alkokene group, a substituted amino group, a hydroxyl group, a halogen atom, or an aryl group is used.

General formula (T2): However, in this general formula, R25: substituted or unsubstituted aryl group, R2': hydrogen atom, halogen atom, three types of substituted or unsubstituted groups; alkyl group, alkokino group, amino group and hydroxyl group, R27: two types of substituted or unsubstituted groups; alkyl group,
Represents a heterocyclic group.

In addition, the following general formulas [T3], [T4], (T
The hydrazone compounds of 4a), (T4b) or [T5] can also be used.

General formula (T3): However, in this general formula, R2m and R2' = each a hydrogen atom or a halogen atom, RIG and R31, each a substituted or unsubstituted aryl group, Ar": represents a substituted or unsubstituted aryl group .

General formula [:T4): However, in this general formula, R3! : Represents three substituted or unsubstituted groups, a carbazolyl group, and a heterocyclic group, R33, R11 and R35; hydrogen atom, alkyl group, nearyl group, two substituted or unsubstituted groups; represent.

General formula (74a): However, in this general formula, R3': methyl group, ethyl group, 2-hydroxyethyl group, or 2-chloroethyl group, R37: methyl group, ethyl group, benzyl group, or phenyl group, R38・methyl group, ethyl group, benzyl group or phenyl group.

However, in this general formula, R31 is a substituted or unsubstituted naphthyl group, R4° is a substituted or unsubstituted alkyl group,
Aralkyl group, aryl group; R'1 is a hydrogen atom, alkyl group or aryl group; R42 and R43 are the same or different groups consisting of a substituted or unsubstituted alkyl group, aralkyl group or aryl group;

General formula 1: T5): However, in this general formula, R44 - two types of substituted or unsubstituted groups; aryl group,
Heterocyclic group, R″: hydrogen atom, two types of substituted or unsubstituted groups: alkyl group, aryl group, Q: hydrogen atom, halogen atom, alkyl group, substituted amine group, alkokene group or anno group, S: 0 Or represents an integer of 1.

Furthermore, as the CTM, the following general 2〇T6] Biazoline compound can also be used.

General formula (T6): However, in this general formula, l: 0 or 11 R'' and Rit: substituted or unsubstituted aryl group, R
1: Substituted or unsubstituted aryl group or heterocyclic group, R1 and R50: Hydrogen atom, alkyl group having 1 to 4 carbon atoms, or substituted or unsubstituted aryl group or aralkyl group (However, R" and R50 are (R49 is not a hydrogen atom when 1 is 0.) Furthermore, an amine derivative of the following general formula [T7] can also be used as a CTM.

General formula (T7): However, in this general formula, Ar's and Ar's represent a disubstituted or unsubstituted phenyl group, and a halogen atom, an alkyl group, a nitro group, or an alkoxy group is used as a substituent.

Ar”: R-substituted or unsubstituted phenyl group, naphthyl group, anthryl group, fluorenyl group, or heterocyclic group; substituents include alkyl group, alkoxy group, halogen atom, hydroxyl group, aryloxy group, aryl group, amino group, nitro group, piperidino group, morpholino group, naphthyl group, anthryl group and substituted amine group.

However, the substituent of the substituted amine group and Anru group, alkyl group, ant Uses a metal group.

Furthermore, a compound of the following general formula [T8] can also be used as a CTM.

General formula (T8:]: However, in this general formula, Ar”: substituted or unsubstituted arylene represents the group, R5I, R52, Rs+ and R51 : Three types of substituted or unsubstituted groups: Alkyl group, aryl group, aral Represents a kill group.

Furthermore, the compound of general formula [T9] can also be used as a CTM.

General formula CT9): However, in this general formula, R5H, R5H, R57 and R2
H is a hydrogen atom, a substituted or unsubstituted alkyl group, an alkyl group, an alkenyl group, an aryl group,
Benzyl group or aralkyl group, Rss and R61),
1 hydrogen atom, substituted or unsubstituted carbon atom, respectively
~40 alkyl groups, nocroalkyl groups, alkenyl groups, nocroalkenyl groups, aryl groups or aralkyl groups (
However, R61 and Rho jointly have a carbon atom number of 3 to IO.
may form a saturated or unsaturated hydrocarbon ring.

) R'', R'', R'3 and R1 are each hydrogen atom, halogen atom, hydroquine group, substituted or unsubstituted alkyl group, cycloalkyl group, alkenyl group, aryl group, aralkyl group, alkoxy group, amino group, alkylamino group or arylamino group.

An antioxidant can be contained in CTL and CGL.

This can suppress the influence of ozone generated during discharge, and can prevent an increase in residual potential and a decrease in charged potential during repeated use.

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 Laid-Open No. 63-4466.
No. 2, No. 63-14153, No. 63-50849,
No. 63-18355, No. 63-58455, No. 63
-71856, 63-71855 and 66-1
It is described in No. 46046.

A polymer semiconductor can also be included in the photosensitive layer.

Among these polymeric organic semiconductors, poly-N-vinylcarbazole or its semiconductor is highly effective and is preferably used. Such poly-N-vinylcarbazole derivatives mean that all or part of the carbazole ring in the repeating unit has various substituents, such as an alkyl group, a nitro group,
Substituted with an amino group, a hydroquine group, or a halogen atom.

Further, at least one electron-accepting substance may be contained in the photosensitive layer for the purpose of improving sensitivity, reducing residual potential or fatigue during repeated use, and the like.

Examples of electron-accepting materials that can be used in the photoreceptor of the present invention include amber anhydride, maleic anhydride, dibromaleic anhydride, phthalic anhydride, tetrachloroheptalic anhydride, tetrabromohttalic anhydride, 3-nitro Phthalic anhydride, 4-nitro-7thalic anhydride, pyromellitic anhydride, mellitic anhydride, tetracyanoethylene, tetracyanoquinodimethane, 0-dinitrobenzene, m-dinitrobenzene,! , 3.54 linitrobenzene, paranitrobenzonitrile, picryl chloride, quinone chlorimide,
Chloranil, brumanil, 2-methylnaphthoquinone, dichlordicyanoparabenzoquinone, anthraquinone, dinitroanthraquinone, trinitrofluorenone, 9-
Fluorenylidene [dicyanomethylene malonodinitrile], polynitro-9-fluorenylidene [dinanomethyline malonodinitrile], picric acid, 0-nitrobenzoic acid, p-nitrobenzoic acid, 3,5-dinitro Examples include benzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, phthalic acid, mellitic acid, and other compounds with high electron affinity. Among these, fluorenone series, quinone series, and benzene derivatives having electron-withdrawing substituents such as CI, CN, and No are particularly preferred.

Additionally, lilycorn oil or fluorine surfactant may be present as a surface modifier. Further, an ammonium compound may be contained as a durability improver.

Furthermore, an ultraviolet absorber may be used. - Preferred ultraviolet absorbers include nitrogen-containing compounds such as benzoic acid, stilbene compounds and their derivatives, triazole compounds, imidazole compounds, triazine compounds, coumarin compounds, oxadiazole compounds, thiazole compounds and their derivatives.

Examples of binder resins that can be used for the constituent layers of the photoreceptor include polyethylene, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, polyester resin, alkyd resin, polycarbonate resin, and melamine resin. , addition polymer resins such as methacrylic resins, acrylic resins, polyvinidene chloride, polystyrene, polyaddition resins, polycondensation resins, copolymer resins containing two or more of these repeating units, vinyl chloride-vinyl acetate Examples include insulating resins such as copolymer resins, styrene-butashun copolymer resins, hnylidene chloride-acrylonitrile copolymer resins, polymeric organic semiconductors such as N-hinylcambazole, modified linicone resins, etc. I can do it.

The above binders can be used alone or as a mixture of two or more.

The binder for the protective layer provided as necessary has a volume resistance of 10'Ω·Cm or more, preferably 1010Ω·Cm.
A transparent resin having a resistance of at least 10"Ω·Cm, more preferably at least 10"Ω·Cm, is used.

Further, the binder may be a resin that is cured by heat, and examples of the resin that is cured by heat include thermosetting acrylic resin, epoxy resin, urethane resin, urea resin, polyester resin, alkyd resin, melamine resin, Alternatively, there are copolymerized or condensed resins thereof, and all other thermosetting resins used in electrophotographic materials can be used.

Further, if necessary, the protective layer may contain less than 5 Qwt% of a thermoplastic resin for the purpose of improving processability and physical properties (preventing cracks, imparting flexibility, etc.). Examples of such thermoplastic resins include polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, epoxy resin, polycarbonate resin, or copolymer resins thereof, polymeric organic semiconductors such as poly-N-vinylcarbazole, and other electrophotographic materials. All of the thermoplastic resins that are available are utilized.

CGL can be provided by the following method.

(a) A method in which a binder and a solvent are added to CGM, etc., and a mixed solution is applied.

(b) A method in which CGM, etc. is made into fine particles in a dispersion medium using a ball mill, homomixer, sand mill, ultrasonic disperser, attritor, etc., and a binder is added, mixed and dispersed, and the resulting dispersion is applied.

Dispersing the particles under the action of ultrasound in these methods allows for homogeneous dispersion.

Further, the CTL can be formed by applying and drying the CTM described above alone or dissolved and dispersed together with the binder resin described above.

In this case, when CTM is contained in CGL,
There is a method of dissolving or dispersing CTM in advance in the solution of (a) or dispersion of (b), ie, a method of adding CTM to CGL. In this case, the amount of CTM added is preferably within the range of 1-100 parts by weight per 100 parts by weight of the binder.

In addition, a solution containing CTM is applied onto the CGL, and the CGL
There is a method of diffusing CTM into CGL by swelling or partially dissolving CTM. If this method is adopted,
Although it is not necessary to add CTM to CGL as described above, it is also possible to carry out the above-mentioned duality at the same time.

Solvents or dispersion media used to form the layer include butylamine, diethylamine, ethylenediamine, impropaturamine, triethanolamine, triethylenediamine, N,N-dimethylformamide, acetone, methyl ethyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, 1,2-dichloroethane, dichloromethane, tetrahydrofuran,
Examples include dioxane, methanol, ethanol, impropatol, 9-ethyl acid, butyl acetate, dimethyl sulfoxide, and the like.

The above-mentioned PCLXUCL, OCL, etc. can be provided by, for example, blade coating, dip coating, spray coating, roll coating, spiral coating, or the like.

The conductive support is prepared by coating, vapor depositing, laminating, or the like a conductive thin layer made of a metal plate, metal drum, or a conductive polymer, a conductive compound such as indium oxide, or a metal such as aluminum, palladium, or gold. A type provided on a substrate such as paper or plastic film is used.

Next, FIG. 5 shows an example of a recording apparatus using the photoreceptor of the present invention.

FIG. 6 is a flowchart of a reversal development method in electrophotography.

In the apparatus shown in FIG. 5, reference numeral 23 includes a drum-shaped image carrier having the above-mentioned organic photoconductive substances PCL 8 and UCL 7 and rotating in the direction of the arrow; 22 an image carrier; and 23 has a uniform surface. A charger for charging, 24 is an image exposure device, and 15 is a developing device.

Reference numeral 20 denotes a pre-transfer exposure lamp provided as necessary to facilitate the transfer of the toner image formed on the image carrier 23 onto the recording medium P, 21 a transfer device, and 19 a corona discharger for separation. , 12 is a fixing device that fixes the toner image transferred to the recording medium P.

Reference numeral 13 has a static eliminator consisting of one or a combination of a static eliminator lamp and a corona discharger for static elimination, and 14 has a cleaning blade or far plan for removing residual toner on the surface of the image carrier 23 after the image has been transferred. When the cleaning device performs 16° image exposure using a semiconductor laser, in the case of a recording device using a drum-shaped image carrier 23 like the recording device in the second section, the image exposure 24 is preferably performed using a laser beam scanner. .

Further, in a recording apparatus in which the image carrier can take a flat state such as a belt shape, the image exposure can be made into 7-ratunyu exposure.

The method shown in FIG. 6 can be carried out using the recording apparatus as described above.

Figure 6 shows that an electrostatic image is formed by an electrostatic image forming method in which the image exposure area is an electrostatic image with a lower potential than the background area, and development is performed using toner that is charged to the same polarity as the background area potential after electrostatic development. This figure shows an example of reversal development performed by adding a paste.

That is, first, the surface of the image carrier 23 in the initial state, which has been neutralized by the static eliminator 13 and cleaned by the cleaning device 14 and has a potential of 0, is uniformly charged by the charger 22. Image exposure 24 is projected onto the charged surface to perform image exposure such that the potential of the electrostatic image portion becomes approximately 0, and the obtained electrostatic image is developed by a developer 15 (toner T).

Note that this image forming method can be applied to various light sources such as a halogen lamp, a tungsten lamp, an LED (light emitting diode), a gas laser such as helium-neon, argon, helium-cadmium, etc., and a semiconductor laser.

The image forming method of the present invention has a wide variety of applications such as electrophotographic copying machines and printers.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited thereby, and of course includes other embodiments with various modifications.

First, as shown in Table 1, UCL No., UCL-IE
A total of 6 coating liquids from T to 6ET were prepared, and each was 0.6 gm.
Filter it through a filter and use it as a coating solution for UCL.

These UCL coating liquids were applied to an aluminum drum (Konica LP).
-3010 for laser printer), 4mg/dm
The pulling speed was adjusted to 2 to form a UCL.

UCL-I ET is a normal polyacrylate resin and is a blank.

For UCL-2ET-UCL-4ET, after dip coating, the drum was rotated slowly and UV irradiation was performed for 60 seconds from a distance of about 50 cm using a concentrating medium pressure mercury lamp with an output of 80 W/cm, resulting in a coating amount of 4 mg/cm. U to become dm2
CL was formed.

For UCL-5ET and DCL-6ET, after dip coating, while rotating the drum, an accelerating voltage of 300 KV,
Using an ESI (curtain type) electron beam accelerator with a heap current of 1010-15, the absorbed dose is 3 to 10 Mr.
Electron beam irradiation was performed in the ad range to form a UCL at 4 mg/dm'.

Two UCL-coated drums were each coated, one was coated with the next CGL multilayer coating, and the other was used for the adhesion test (baseline test) and melt resistance table 1 shown in Table 2 below. 40 g of CGM was added to a polymer solution containing 40 g of each binder and 200 ml of each solvent, and dispersed for 12 hours using a sand grinder to prepare a CG, L peripheral dispersion.

The cylinder having the above UCL is immersed in this dispersion, and C
The coating speed was adjusted so that the amount of GL applied was 5 mg/dm2.

Table 2 Furthermore, 200 g of cTM shown in Table 3 and 450 g of the resin shown in Table 3 were added to 1,500 ml of 1,2-dichloroethane.
Each drum coated up to the CGL was immersed in the resulting solution, the coating speed was adjusted to give a film thickness of 200 μm, and the coating was dried at 100°C for 1 hour.
A TL was formed to produce a laminated photoreceptor.

Table 3 The final laminated form of the photoreceptor is shown in Table 4, and will also be described below.

Electrophotographic properties and properties measured by the measurement method [Characteristics evaluation] Each of the photoreceptors of Examples and Comparative Examples was
Installed on a 10J (manufactured by Konica) modified machine (equipped with a semiconductor laser light source), the grid voltage was adjusted so that v2 was -600±10cV), and the potential of the exposed surface when irradiated with 0.7+W was set as VL. Reversal development was performed at a developing bias of -500 (V), and black spots in the white background portion of the image were evaluated.

Also, print 5,000 times, and after 5,000 prints, the result is vM1vLwovMs000%VLsOO0.

Then, the displacement amounts of V M and V L from the initial stage are A y &150011 and A V L"", respectively.

Follow, A V MSooo += (V M5011
0 + 600), ΔV L”00-(V L”DoV
L).

For evaluation of black spots, the particle size and number of black spots were measured using an image analysis device "Omnicon 3000" (manufactured by Takasu Seisakusho Co., Ltd.), and - (diameter) 0.05■ Judgment was made based on the number of black spots of ■ or above per 1 cm. The criteria for evaluating black spots are as shown in the cloth below.

Note that if the result of black spot determination is ◎ or ○, it is practical, but if it is △, it may not be suitable for practical use, and if it is ×, it is not suitable for practical use.

In addition, in order to examine the solvent resistance of UCL, after coating and drying UCL, it was immersed in methyl ethyl ketone for 30 seconds, and then observed using an electron microscope (SEM). UC of immersion surface
L indicates that the sample remains homogeneous, and ◎ indicates that the sample remains homogeneous, and △ or X indicates that the sample is heterogeneous or has dissolution or peeling.

The adhesion between UCL and PCL was evaluated by a substrate test. In other words, the distance between adjacent gaps is l
Using a +w+++ cutter guide, make 11 parallel scratches in the vertical and horizontal directions with a cutter to form 100 squares (base squares). After pasting cellophane tape with a diameter of 24 mm on top of it, peel it off from one end. The number of squares that were peeled off at that time was counted and expressed as the number of squares that remained out of 100.

As a guideline for adhesion, 100/100 is considered good adhesion, and 0/100 is considered poor.

According to the results shown in Table 4, by using the resin of the present invention, it is possible to maintain good charging ability and sensitivity during repeated use, and to produce good images without black spots, as well as to produce a photoreceptor with excellent adhesion. I know what I can offer.

On the other hand, when a comparative binder resin was used, part of the UCL dissolved after the CGL solution was applied, resulting in poor multilayer coating properties.
In addition, many black spots also occurred.

Next, photoreceptors similar to those in the above-mentioned example were prepared with a drum size for PC-8010 (manufactured by Konica). When images were produced on each of these photoreceptors using the DC-8010 under the following development conditions, good images without black spots were obtained under each development condition, regardless of which photoreceptor was used. It was done.

The development was carried out by so-called two-component non-contact jumping development.

Development conditions: 70 wt% magnetite powder with an average particle size of 0.1 μm, 3 Qwt% polyester resin as a binder resin,
The mixture was kneaded, crushed and granulated, and then classified into particle sizes of 20 to 30 μm to obtain a carrier. The specific gravity of this carrier was about 3.5 or less. To this carrier, U-Bix 1800 (manufactured by Konica) toner for copying machine (toner containing carbon in polyester resin) was blended so that the toner concentration was 2Qwt%, and copying was performed under the following conditions.

The peripheral speed of the image carrier is 60 mm/sec, the gap between the image carrier and the developing sleeve is Q, and the developer layer thickness is 0.05 m per 3 mm.
m.

The diameter of the developing sleeve is 24 mm, and the rotation speed is 20 Orr.
It was set as pm.

Regarding the current t bias, etc., the following three types of conditions were used.

[Brief explanation of the drawing]

1 to 7 are for explaining the embodiment, and FIG. 1(A) and FIG. 1(B) are schematic diagrams each schematically showing the movement of the carrier using a hand model. , FIG. 2, FIG. 3, and FIG. 4 are sectional views of a portion of each photoreceptor used in the present invention, FIG. 5 is a schematic diagram of an image forming apparatus, and FIG. 6 is a flow chart showing the process of image formation. FIG. 7 is a partial sectional view showing a conventional photoreceptor. FIG. 8 is an enlarged cross-sectional view of a part of another conventional photoreceptor. In addition, in the symbols shown in the drawings, l... Conductive substrate 4... Carrier transport layer (CTL)
'6...Carrier generation layer (CGL)7.
・・・・・・・・・Undercoating layer (UCL) 8・・・・・・・・・
- Photosensitive layer (PCL).

Claims (2)

[Claims] (1) A photoreceptor in which at least an undercoat layer and a photosensitive layer are provided on a conductive support, wherein the undercoat layer is formed of a polyether radiation-curable resin. . (2) The polyether radiation-curable resin has at least one of radiation-sensitive unsaturated double bonds such as acrylic double bonds, allylic double bonds, and maleic acid double bonds in side chains and/or terminals. The photoreceptor according to claim 1.