JPH0358054A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance electrophotographic sensitivity at the time of positive charging by forming a photosensitive layer containing a specified eutectic complex containing a specified compound. CONSTITUTION:This photosensitive body is provided with the photosensitive layer made of the eutectic complex composed of a pyrylium type dye (A) and an electrically insulating polymer, such as polycarbonate, containing the com pound of formula I in which each of R<1>, R<3>, and R<4> is H, amino, alkoxy, or the like, and R<2> is H, alkoxy, optionally substituted alkyl, or the like. The pyrylium type (A), such as 4-(4-dimethyl-aminophenyl)-2, 6-diphenylthiapyrylium perchlorate, can be used, and the compound of formula I, in which each of R<1> and R<2> is H and R<3> is 4-OCH3 and R<4> is 4-CH3 and the like can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an electrophotographic photoreceptor, and more particularly, to an electrophotographic photoreceptor in which a substance having a specific structure is added to a eutectic complex photoreceptor layer, and an electrophotographic photoreceptor in which a substance having a specific structure is added to the photoreceptor layer (the first photoreceptor layer). The present invention relates to a composite photoreceptor for electrophotography (for two-color process) formed by laminating a first photosensitive layer and a second photosensitive layer.

[Prior art]

Electrophotographic photoreceptors having a photoconductive layer made of a composition containing a eutectic complex consisting of a pyrylium dye and a Denki 1# polymer and, if necessary, a triphenylmethane sensitizer, are known ( For example, Japanese Patent Publication No. 46-22518, No. 46-22518,
Publication No. 22519, Publication No. 51-1129, Japanese Unexamined Patent Publication No. 4
7-10785, 51-88226, 51-93324, 53-87227, etc.).

Although these photoreceptors have electrophotographic sensitivity to a level that is acceptable for practical use, they have not yet reached a level of sufficient electrophotographic sensitivity.

〔the purpose〕

An object of the present invention is to provide a photoreceptor incorporating a eutectic complex photosensitive layer having extremely excellent electrophotographic sensitivity.

More specifically, it is an object of the present invention to provide a photoreceptor having a eutectic complex photosensitive layer having particularly excellent electrophotographic sensitivity under positive t-voltage.

Another object of the present invention is to provide an electrophotographic photoreceptor that can be easily manufactured.

〔composition〕

The present inventors have developed a compound represented by the following general formula (1) (in the formula, R1.R3 and R4 is a hydrogen atom, an amino group,
alkoxy group, thioalkoxy group, aryloxy group,
R2 represents a methylenedioxy group, a substituted or unsubstituted alkyl group, a halogen atom, or a substituted or unsubstituted aryl group, and R2 represents a hydrogen atom, an alkoxy group, a substituted or unsubstituted alkyl group, or a halogen.

However, Ri. Except when R2, R3 and R4 are all hydrogen atoms. Also, k, 12, m and n are 1, 2,
is an integer of 3 or 4, and when each is an integer of 2, 3 or 4, the above R'', R''R3 and R4 may be the same or different. ) was found to provide extremely excellent electrophotographic sensitivity, leading to the present invention.

Therefore, the electrophotographic photoreceptor of the present invention contains pyrylium dye,
It is characterized in that a photoconductive layer (eutectic complex photosensitive layer) containing an electrically insulating polymer and a compound represented by the general formula (1) as main components is provided on a conductive substrate.

The present invention will be further explained below with reference to the drawings.

FIG. 1 is a sectional view showing an example of the structure of the electrophotographic photoreceptor of the present invention, in which a eutectic complex photoreceptor, an Iil
5 is provided.

FIG. 2 shows another example of the structure of the present invention, in which a subbing layer 14 is provided between the conductive substrate and the eutectic complex photosensitive layer.

Further, FIG. 3a shows a composite photoreceptor for electrophotography according to the present invention. A photosensitive layer 12 (hereinafter referred to as a second photosensitive layer) sensitive to light transmitted through the eutectic complex photosensitive layer is formed on a conductive substrate.
is provided, and a eutectic complex photosensitive layer is further provided thereon.

FIG. 3b shows another structural example of a composite photoreceptor for electrophotography, in which an intermediate layer 1'I13 is provided between the second photosensitive layer and the eutectic complex photosensitive layer.

As the conductive substrate 11, materials exhibiting conductivity with a volume resistance of 101 oΩcI1 or less, for example, metals such as aluminum, nickel, chromium, nichrome, copper, silver, gold, platinum, etc.
Gold such as tin oxide, indium oxide, etc. ii. ．． m-ide,
Film-like or cylindrical plastic or paper coated by vapor deposition or sputtering, or
D. plates of aluminum, aluminum alloy, nickel, stainless steel, etc. I. ,I. I. , extrusion,
It is possible to use a tube that has been made into a blank tube by a method such as drawing, and then surface-treated by cutting, superfinishing, polishing, etc. The eutectic complex mainly composed of a conductive substance represented by formula (1) is made from a pyrylium dye and an electrically insulating polymer.

There are three types of pyrylium dyes: pyrylium salts, thiapyrylium salts, and se1nonapyrylium salts, and they have the following general formula.

abed In the above formula, R , R . R , R and e R are each a group selected from the following groups (a), (b), (c) and (d), (a): hydrogen atom, (b): alkyl group, representative Examples include methyl, ethyl, proyl, isopropyl, butyl, t-butyl, amyl,
Alkyl groups from 01 to C such as isoamyl, hexyl, octyl, nonyl, dodecyl, etc.; (C); alkoxy groups such as methoxy, ethoxy, propoxy, butoxy, amyloxy, hexoxy, octoxy; (d); phenyl, 4- Alkylphenyls such as diphenyl, 4-ethylphenyl, 4-probylphenyl; 4-ethoxyphenyl, 4-methoxyphenyl, 4
-amixoxyphenyl, 2-hexoxyphenyl, 2-
Alkoxyphenyls such as methoxyphenyl and 3,4-dimethoxyphenyl; β-hydroxyalkoxyphenyls such as 2-hydroxyethoxyphenyl and 3-hydroxyethoxyphenyl; 4-hydroxyphenyl,
Halophenyls such as 2,4-dichlorophenyl, 3,4-dibromophenyl, 4-chlorophenyl, 3,4-dichlorophenyl; azidophenyl, nitrophenyl,
Aminophenyls such as 4-diethylaminophenyl and 4-dimethylaminophenyl; naphthyl, styryl, methoxystyryl. Including substituted aryl groups such as vinyl substituted aryl groups such as diethoxystyryl, dimethylaminostyryl, 1-butyl-4-p-dimethylaminophenyl-1,3-butadienyl, β-1ethyl-4-dimethylaminostyryl, etc. represents an aryl group, X is a sulfur, oxygen or selenium atom, and Z is berchlorate, fluoroborate, iodide, chloride, bromide, sulfate, periodide, p-toluenesulfonate, hexafluorophosphate It is an anionic functional group such as.

Furthermore, Ral Rb# R01 Rd and R may be atoms necessary to complete the aryl ring fused to the pyrylium nucleus. Representative examples of such pyrylium dyes are shown below.

lolate ethenyl pyrylium bark chlorate crate 28 6-(3,4-diethoxy β-amyl schitorate monototyryl)-2,4-cyphenylpyrylium fluoroborate 1to1 trolate sulfate 1tobis( 4-Methoxyphenyl) theabyrylium perchlorate chlorate monothorium perchlorate chlorate chlorate (b) selenapyrylium perchlorate chlorate chlorate 89 4-(4-dimethylaminophenyl)-2,6-diphenylpyrylium Hexafluorophosphate A particularly useful pyrylium dye is one having the general formula:

R, where R and R3 are C-C6 alkyl groups and C-C
is an aryl group such as a substituted phenyl group having at least one substituent selected from the alkoxy groups of R
3 is an alkylamino-substituted phenyl group in which the alkyl moiety is C-C6, and may also be a dialkylamino-substituted or haloalkylamino-substituted phenyl group, X is oxygen, sulfur or selenium atom, and Z- is as described above.

As electrically insulating polymers, those having an alkylidene diarylene moiety represented by the following formula in the main chain (repeat unit) are particularly useful. R, where R4 and R each represent a hydrogen atom, methyl containing a substituted alkyl group such as trifluoromethyl, ethyl, proyl, isopropyl, butyl, t-butyl, benzyl,
aryl groups such as phenyl and naphthyl, including substituted aryl groups having substituents such as alkyl groups such as hexyl, heptyl, octyl, nonyl, decyl, halogen, alkyl groups of Ci to C, and aryl groups such as phenyl and naphthyl; may be the carbon atoms necessary to jointly form a cyclic hydrocarbon group including cycloalkanes such as cyclohexyl and polycycloalkanes such as norbornyl.
R6 and R7 are hydrogen, an alkyl group of 01 to C1, or a halogen such as chloro, bromine, or iodine, and R is OS 1o-c-o- -o-c-o- 0 -C-O- 0 It is a divalent group selected from the group consisting of I1 -C-0-CH, - O O CH3 [11 -C-0-CH- 0 ].

Hydrophobic carbonate polymers (polycarbonate 1-) comprising repeating units of the following formula are also useful and preferred.

R40 11 -R-C-R-0-C-0- 1 R. In the formula, R is a phenylene group including halo-substituted phenylene groups and alkyl-substituted phenylene groups, and R. and R5 are as described above. These polymers are tJsP3
, No. 028,365 and No. 3,317,466. Preferably, it contains a 7-alkylidene diarylene moiety in the repeating unit, such as made from bisphenol A, diphenyl carbonate and 2,2-bis(4-
Polycarbonates containing polymers formed by transesterification with (hydroxyphenyl)propane are useful. Such polymers are USP 2,999,750
No. 3,038,874, No. 3,038,880, No. 3,106,544, No. 3,106,545,
It is disclosed in No. 3,106,546, etc. In any case, polycarbonate resins in film form can be used in a wide variety of ways. Particularly satisfactory results are obtained when using those having an intrinsic viscosity of about 0.5 to 1.8. Specific examples of the electrically insulating polymer are as follows.

3 Poly(4,4'-isopropylidene diphenylene carbonate co-terephthalate)l5 Poly(4,4'-isopropylidene diphenylene carbonate co-terephthalate carbonate) (hereinafter referred to as the margin) Also represented by general formula (I) Representative examples of the compounds are shown below.

To make the eutectic complex photosensitive NI15 of the present invention, the above pyrylium dye, electrically insulating polymer, and general formula (1
) is dissolved in a suitable solvent such as tetrahydrofuran, toluene, 1,2-dichloroethane, methylene chloride, chloroform, monochlorobenzene, dichlorobenzene, benzene, etc., and this is added to the conductive substrate 11.
Coat on top and dry at 50-130℃ to obtain a film thickness of 5-50℃.
It is sufficient to form a photoconductive layer (eutectic complex photosensitive layer) 15 with a thickness of μm. Application can be done using dip coating, bead coating, spray coating, wire blade, doctor blade, air knife, etc. During this coating and drying process, a eutectic complex is formed between the pyrylium dye and the electrically insulating polymer.

The proportion of each part in the eutectic complex photosensitive layer 15 is 5 to 80 parts by weight of the electrically insulating polymer per 1 part by weight of the pyrylium dye.
Parts by weight, preferably 7 to 40 parts by weight, the general formula (1)
1 to 50 parts by weight, preferably 3 to 30 parts by weight of a compound represented by
Parts by weight are appropriate.

Further, when forming this 115, a leveling agent such as silicone oil may be added to the coating liquid. The appropriate amount to be used is about 0 to 1% by weight based on the electrically insulating polymer.

Furthermore, when providing the layer 15, a binder may be used if necessary.

The binder materials used here include polyethylene, polystyrene, polybutadiene, styrene-butadiene copolymer,
Polymers and copolymers of acrylic esters or methacrylic esters, polyesters, polyamides, epoxy resins, urethane resins, silicone resins, alkyd resins, cellulose resins, poly-N-vinyl rubbersole and its derivatives (for example, chlorine in the carbazole skeleton). , halogens such as bromine, methyl groups, substituents such as amino groups), polyvinylpyrene, polyvinylanthracene, birene-formaltehyde condensation polymers and their derivatives (for example, pyrene skeletons with halogens such as bromine, nitro groups, etc.) ), poly γ-carbazolylethyl-L-daltamate, styrene resin, chlorinated polyethylene, acetal resin, melamine resin, etc.

A plasticizer can be used in combination with this binder. Plasticizers that are commonly used as plasticizers for resins include dibutyl phthalate and dioctyl phthalate.
It can be used as is.

The amount used is approximately 0 to 30% by weight based on the resin binder.

Note that when forming the eutectic complex photosensitive layer 15 of the present invention, the method of overcoating the coating liquid (Japanese Unexamined Patent Publication No. 56-40837) or the coating of the already formed electrically insulating polymer layer with pyrylium dye Method of drying after soaking in
(Japanese Unexamined Patent Publication No. 121042/1982) may be used, or the layer 15 may be formed so that the concentration of the pyrylium dye is different on the conductive substrate side and near the surface. good.

In the present invention, as shown in FIG. 2, by providing a subbing layer 14 between the conductive substrate and the eutectic complex photosensitive layer, charging properties and adhesion properties can be improved.

The undercoat layer 14 may be made of an inorganic material such as Sin, An80, etc., provided by vapor deposition, sputtering, or anodization, or may be made of polyamide resin, alcohol-soluble nylon resin,
A resin layer made of water-soluble polyvinyl butyral resin, polyvinyl butyral resin, etc. can also be used.

Further, ZnO+TiO. A dispersion of pigment particles such as ZnS can also be used as the undercoat layer.

Furthermore, subtraction of the present invention, 11! As F14, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, etc. can also be used.

The thickness of the undercoat layer 14 is suitably 0 to 5 μm.

Further, in the present invention, it is also possible to provide a protective layer or an insulating layer on the eutectic complex photosensitive layer 15.

The protective layer is provided for the purpose of protecting the surface of the photoreceptor, and materials used for this include ABS resin, ACSm resin, olefin-vinyl monomer copolymer, chlorinated polyether,
Allyl resin, phenolic resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallyl sulfone, polybutylene, polybutylene terephthalate, polycarbonate, polyether sulfone, polyethylene, polyethylene terephthalate, polyimide,
Acrylic resin, polymethylbentene, polypropylene,
Examples include resins such as polyphenylene oxide, borisulfone, polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, polyvinyl chloride, polyvinylidene chloride, and epoxy resin. In addition, the protective layer may also contain fluororesins such as polytetrafluoroethylene, silicone resins, and inorganic materials such as titanium oxide, tin oxide, potassium titanate, etc. dispersed in these resins for the purpose of improving wear resistance. Can be added. A normal coating method is adopted as a method for forming the protective layer. The thickness of the protective layer is 0.
．． Approximately 5 to 10 μm is appropriate. For the insulating layer, the binder material that may be used in the eutectic complex photosensitive layer mentioned above can be used as is, or a solution containing the binder material can be applied. In addition, heat-shrinkable films or tubes made of polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon, etc. can also be used.

An example of the present invention is a composite photoreceptor for electrophotography as shown in FIGS. 3a and 3b.

For the second photosensitive layer 12 and the intermediate layer 13, known materials (for example, JP-A-56-121044) can be used, and for the first photosensitive layer, the above-mentioned eutectic complex photosensitive layer 15 can be used.
can be used.

An image can be formed on the composite photoreceptor for electrophotography formed in this manner by applying a known process (for example, Japanese Patent Application Laid-open No. 121044/1983).

〔Example〕

A coating solution consisting of 650 parts by weight of methylene chloride was applied onto a polyethylene terephthalate film on which AI2 had been deposited and dried to form a eutectic complex photosensitive layer with a dry film thickness of 16 μm.

A photosensitive layer was formed in the same manner as in Example-1 except that a triphenylmethane compound of the following structural formula (n) was used instead of the compound of formula (1) in Example-1. Intimidated.

The photoreceptor obtained as described above was attached to an electrostatic paper analyzer (SP-428 manufactured by Kawaguchi Electric Seisakusho Co., Ltd.), and the corona discharge pressure was -5.5.
kv or +6. Potential Va(
V), potential Vo (V) after 10 seconds of dark decay, intensity 1012
The residual electricity vm (v) after 15 seconds of exposure at ux, and the exposure amount E required to further attenuate the potential Vo to 175 1/
5 (breath ux-sac) was measured. The potential holding rate is defined as follows.

Vm Also, IFm under the above conditions! After exposing the photoreceptor to light for one hour at the same time to fatigue the photoreceptor, the characteristics of the photoreceptor were further measured in the same manner as above.

The results are shown in Table-1.

(Left space below) Table-1 Table-1 instead of the compound of general formula (1) in Example-1
A photosensitive layer was formed in the same manner as in Example 1 except that the compound shown in Example 2 was used.

Table 2 shows the measurement results of photoreceptor characteristics.

(Margins below) Table 2: Fork 12U Thickness: 0. A subbing layer coating liquid and a eutectic complex photosensitive layer coating liquid having the following compositions were applied onto a 2mo+ AI2 board, dried, and the subbing layer M (thickness: 0.3 μm) and eutectic complex photosensitive layer (film thickness) were coated and dried. The electrophotographic photoreceptor shown in FIG. 2 was prepared by forming a film having a thickness of 15 μm.

(1) Undercoat layer coating liquid Ethanol 300 parts by weight (2) Eutectic complex photosensitive layer coating liquid Compound of general formula (1) shown in Table 3 25 parts by weight Methylene chloride SOO parts by weight Chloroform
150ii parts, parts, back gloss, 2, main examples 8 to 14, except that the triphenylmethane compound of structural formula (n) used in comparative example-1 was used instead of the compound of general formula (1). A photoreceptor was prepared in the same manner as in Example &~14.

Table 3 shows the measurement results of photoreceptor characteristics.

(The following is a blank space) 1369 Table 3 [Effects] According to the present invention, an electrophotographic photoreceptor comprising a eutectic complex photosensitive layer having excellent electrophotographic sensitivity (particularly excellent electrophotographic sensitivity at positive S voltage) and a two-color It is possible to provide a composite photoreceptor for electrophotography for process use.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an electrophotographic photoreceptor of the present invention, FIG. 2 is a sectional view of another electrophotographic photoreceptor of the invention, and FIG.
FIG. 3b is a sectional view of another electrophotographic composite photoreceptor of the present invention. 1l... Conductive substrate 12... Photosensitive N (second photosensitive layer) L3... Intermediate layer 14... Undercoat layer 15.
・Photosensitive layer (eutectic complex)

Claims (1)

[Claims] 1. A photoconductive layer comprising a pyrylium dye, an electrically insulating polymer, and a compound represented by the following general formula (I) as main components is provided on a conductive substrate. Electrophotographic photoreceptor. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (In the formula, R^1, R^3 and R^4 are hydrogen atoms, amino groups, alkoxy groups, thioalkoxy groups, aryloxy groups, methylenedioxy groups , a substituted or unsubstituted alkyl group, a halogen atom, or a substituted or unsubstituted aryl group, and R^2 represents a hydrogen atom, an alkoxy group, a substituted or unsubstituted alkyl group, or a halogen.However, R^1, R Except when ^2, R^3, and R^4 are all hydrogen atoms. Also, k, l, m, and n are integers of 1, 2, 3, or 4, and each is an integer of 2, 3, or 4. When , the above R^1, R^2
, R^3 and R^4 may be the same or different. )