JPS58144833A - Photoconductive composition - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic receptor having high sensitivity and good dark decay characteristics, and good initial potential characteristics, etc., by adding a pyrylium type dye and a hydrazone compd. CONSTITUTION:An intended photoconductive compsn. is obtained by mixing (A) a binder, such as polystyrene or acrylic resin, (B) a pyrylium type dye represented by formulaeI, II where R1-R5 are each H, 1-15C alkyl or alkoxy or the like, ; X is O, S, or the like; Z is an anion; and (m) is 0, 1, or 2, such as formula III, and (C) a hydrazone compd. represented by formula IV and V where A is aryl or the like; R7, R8, R10 are each methyl, ethyl, or the like; R9 is H, aryl, or the like; (n) is 0 or 1; and Z is an atomic group needed to form a hetero ring; such as formula VI. This photoconductive compsn. is applied to a conductive substrate, and dried to form a photosensitive layer, thus an electrophotographic receptor is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an organic photoconductive composition suitable for an electrophotographic photoreceptor, and more particularly to an electrophotographic photoreceptor containing a photoconductive hydrazone compound sensitized to long wavelengths.

Conventionally, as a method for sensitizing a hydrazone compound known as a low molecular weight organic photoconductor, for example, US Pat. No. 415
0987, No. 4278747, etc., a method using a laminated structure in which a coating layer containing a disazo pigment or a phthalocyanine pigment as a charge generating substance is electrically connected to a layer containing a hydrazone compound. is generally known. The coating layer containing the disazo pigment or the seven-tone Russianino pigment functions as a charge generation layer, and the coating layer containing hydrazone functions as a charge transport layer.

However, when creating this type of electrophotographic photoreceptor, two
It is necessary to form two coating layers, and the charge generation layer contains as much charge generation material as possible to obtain sufficient light absorption, and to smoke the generated charge carrier particles. It is necessary to form a thin film layer, for example, a thin film layer having a film thickness of dα01 to 1 micron.

Techniques for forming thin film layers are more difficult than techniques for forming thicker film layers. For example, there is a problem in that the setting range of coating conditions and drying conditions for forming a coating layer with a uniform thickness is limited to a narrow range. In particular, when setting mechanical drying conditions, the low boiling point organic solvent contained in the coating solution evaporates rapidly, which may cause the dry coating layer to become distorted and cause emulsion-like surface unevenness. The occurrence of these yuzu milk-like surface spots is not only due to the rapid evaporation of the low-boiling point organic solvent, but also due to other reasons such as the generation of convection caused by heating in the applied coating layer, the surface drying rate and the internal drying rate. It is also thought that this may be caused by differences in the

In addition, since the thin film layer is greatly affected by the surface condition of the substrate, the surface of one substrate must be selected from one with as low surface roughness as possible, and a substrate with a surface roughness larger than necessary should be used. This results in a decrease in the sensitivity of the photoreceptor.

On the other hand, it is also a well-known method to improve the sensitivity and photosensitive wavelength range by directly incorporating a sensitizing dye into a low molecular weight organic photoconductor or an organic photoconductive polymer. For example, polyN disclosed in U.S. Pat. No. 3,484,237
-vinylcarbazole and 2.4.7-) dinitro-9
Examples include a method in which a composition comprising a combination of fluorenone and a composition comprising a combination of triphenylamine, yatriphenylpyra, purine and biryllium dye disclosed in US Pat. No. 3,554,745 is used in an electrophotographic photoreceptor. Although this electrophotographic photoreceptor does not necessarily require the process of forming a thin film such as the above-mentioned charge generation layer and only requires the formation of one coating layer, the sensitivity is still below the practical level. In addition, among the electrophotographic characteristics, the fluctuation in potential when charging and exposure operations are repeated is large, and the fluctuation in dark area potential and bright area potential is large. It has certain drawbacks in providing stable paintings.

An object of the present invention is to provide an organic photoconductive composition suitable for an electrophotographic photoreceptor, which eliminates the above-mentioned drawbacks.

Another object of the present invention is to provide an electrophotographic photoreceptor having good electrophotographic properties.

Another object of the present invention is to provide an electrophotographic photoreceptor having high sensitivity characteristics, good dark decay characteristics, and favorable initial potential characteristics.

These objects of the present invention are achieved by using an organic photoconductive composition containing a pyrylium dye and a hydrazone compound, particularly in the photosensitive area of an electrophotographic photoreceptor.

A preferred embodiment of the present invention has a coating layer containing a beryllium dye and a hydrazone compound in a suitable binder. In the coating layer made of a composition containing a biryllium dye and a hydrazone compound, the biryllium dye is
Hydrazone compounds (organic photoconductors) can function as effective sensitizers. The sensitizing agent in the composition can be included in the film-forming composition in an amount of KO,0001 to 30% by weight, with preferred contents of o,o
os~5.0% by weight. The pi-cider contained in the composition can be selected from a wide variety of resins that have film-forming capabilities. Specific examples of resins that can be used include polystyrene, styrene-butadiene copolymer, styrene/-acrylonitrile copolymer, styrene-maleic acid copolymer, acrylic resin, phenolic resin, polyand, polysulfone, polyvinyl butyral, polyvinyl alcohol, poly; cetal, and polystyrene. Vinyl acetate, bo1) ester, polycarbonate, cellulose resin, etc. can be used.

In particular, the biryllium dye used in the present invention has the following general formula (
1)-(4) , pyrylium salt series dyes such as naphthoselena pyrylium salts.

General formula (1) In the formula, lump, bird, bird, ^ and bird each represent (a) a hydrogen atom (b) an alkyl group, particularly an alkyl group having 1 to 15 carbon atoms: for example, methyl, ethyl, propyl, Isopropyl, butyl, t-butyl, amyl, isoamyl, hexyl, octyl, nonyl, dodecyl (C) alkoxy group: e.g. methoxy, ethoxy,
Propoxy, butoxy, amyloxy, hexoxy, octoxy (d) Aryl group; phenyl, α-naphthyl, β-
Naphthyl (e) Substituted aryl group Nitrile, xylyl, biphenyl, ethylphenyl, methoxyphenyl, ethoxyphenyl, amylxyphenyl, dimethoxyphenyl, jetoxyphenyl, hydroxyphenyl, chlorophenyl, dichlorophenyl, fromophenyl, dibromophenyl, nitrophenyl, diethylaminophenyl , dimethylaminophenyl, diethylaminophenyl (0 styryl group or 4-phenyl-1,3-butadienyl group nistyryl, 4-phenyl-1,3-butadienyl (g) substituted styryl group or u 4-phenyl-1,3-butadienyl Group; methoxystyryl, dimethoxystyryl, ethoxystyryl, jetoxystyryl, diethylaminostyryl, diethylaminostyryl, 4-(P-dimethylaminophenyl)-1,3-butadienyl, 4
-(P-diethylaminophenyl) -1,3-butadienyl (h) Fk and Peng as well as Hachi and Tori can be combined to form a penze/ring.

(Substituted or unsubstituted heterocyclic group: e.g. 3-carbazolyl, 9-methyl-3-carbazolyl, 9-ethyl-
3-carbazolyl, 9-carbazolyl X represents an oxygen atom, a sulfur atom, a selenium atom, and ze
represents an anion such as verchlorate, fluoroborate, iodide, chloride, prop1do, sulfate, periodide, p-toluenesulfonate, and the like. ^ and represent a hydrogen atom, an alkyl group (eg, methyl, ethyl, propyl, butyl, amyl, etc.) or an aryl group (eg, phenyl, naphthyl, etc.).

m is 0, 1 or 2. However, when m is 2, R may be the same or different.

Representative IJ 17um dyes represented by the general formula (1)K are shown below.

l C goose 11 exposure tC,H.

Typical biryllium dyes represented by general formula (2)K are as follows. is as follows.

CBaQ In the electrophotographic photoreceptor of the present invention, the pyri-IJWam dye can be contained in the binder in an amorphous state or in a particle state. The organic solvent used when containing in an amorphous state varies depending on the binder used and the type of the underlying human 2-sine compound, but generally dichloromethane, chloroform, carbon tetrachloride, 1,
1-dichloroethane, 1,2-dichloroethane, 1,1
．． Preferred are halogenated hydrocarbons such as 2-trichloroethane, chlorobenzene, bromobenzene, and 1,2-dichlorobenzene. In addition, when it is contained in a binder in the form of particles, organic solvents that dissolve Ingu and hydrazone compounds, such as alcohols such as methanol, ethanol, and isopropanol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, and N , N
- Amides such as dimethylformamide, N,N-dimethylacetamide, sulfoxides such as dimethyl sulfoxide, ethers such as tetrahydrophene, dioxane, ethylene glycol monomethyl ether, esters such as methyl acetate, ethyl acetate, or penze /, toluene, xylene, aromatics such as refloin, etc. can be used.

In particular, the hydrazone compound used in the present invention has the following general formula (
Compounds represented by 5) or (6) are preferred. In the general formula, (a) aryl group: phenyl, α-su7tyl, β-
Naphthyl, anthralyl, pyrenyl (b) Substituted aryl group: 4-dimethylaminophenyl, 4-diethylaminophenyl, 4-diethylaminophenyl, 4-dibutylaminophenyl, 4-dibenzylaminophenyl, '4-diethylaminophenyl,
4-methoxyphenyl, 2-methoxy-α-naphthyl,
4-methoxy-α-naphthyl, 2,4-dimethoxyphenyl, 2-ethoxy-4-diethylaminophenyl, 4
-p4mo9-antralyl, 4-dimethylamino-9
-Anthralyl (C) Heterocyclic group Nidibenzofuran, carno(zole, indole, thiophene, furan, virole, pyrazole, acridine, xanthine, thioxanthin, phenothiazine, pyridine, phenoxazine, benzimidazole, thiazoline, thiazole, benzothiazole,
A monovalent heterocyclic group (ψ Substituted heterocyclic group: methyl,
Alkyl groups such as ethyl and propyl, halogen atoms such as chlorine and bromine, alkoxy groups such as methoxy, ethoxy and psipoxy, aryl groups such as phenyl, tolyl and xylyl, aralkyl groups such as benzyl and phenethyl, groups such as hydroxy and carboxyl. For heterocyclic groups substituted with one or more atoms, hydrogen atoms, aryl groups (e.g., phenyl, naphthyl, etc.) or substituted aryl groups (e.g., 4-dimethylaminophenyl, 4-diethylminophenyl, 4-
dimethylaminophenyl, 4-methoxyphenyl, 4-
ethoxyphenyl, 2-methylphenyl, 2,4-cy,
J) xyphenyl, etc.), alkyl groups (e.g. memyl, hexyl, cyclohexyl, octyl), substituted alkyl groups (e.g. 2-hydroxyethyl, 3-hydroxyprevyl, 2-methoxyethyl, 3-methoxyethyl,
2-cyanoethyl, 3-cyanopropyl, carboxymethyl, 2-carboxyethyl, 2-chloroethyl, 3-
chloropropyl), aralkyl groups (e.g. benzyl,
phenethyl, 3-phenylpropyl, α-naphthylmethyl, β-naphthylmethyl) or a substituted a2-alkyl group (e.g., methoxybenzyl, ethoxybenzyl, hydroxybenzyl, monobenzyl, tetramopenzyl, methylbenzyl, dimethylbenzyl, dimethylaminobenzyl)
shows. , , and 8 are alkyl groups such as methyl, ethyl, propyl, butyl, amyl, phenyl, α-
Aryl groups such as naphthyl, β-naphthyl kfk, tolyl,
It represents substituted aryl groups such as xylyl, ethylphenyl, methoxyphenyl, ethoxyphenyl, and hydroxyphenyl; aralkyl groups such as benzyl and phenethyl; and substituted aralkyl groups such as methoxybenzyl, ethoxybenzyl, hydroxybenzyl, methylbenzyl, and ethylbenzyl. The proverb is 0 and Fil.

zFi, required to complete a substituted or unsubstituted heterocycle (e.g. oxazole, benzoxazole, naphthoxazole, thiazole, benzothiazole, naphthothiazole, selenazole, benzoselenazole, naphthoselenazole, quinoline, pyridine, indole, etc.) indicates a group of atoms. As a substituent atom or group, 0(d)
Examples include atoms or groups that can be substituted for the substituted heterocyclic group.

Representative examples of hydrazone compounds that can be used in the present invention are listed below.

) Typical examples of hydrazone compounds represented by formula (4) are as follows.

Woodcutter C-4 U Pigeon One or more of these hydrazone compounds Fi or two fl or more can be used in combination.

Coating methods used to manufacture the photoreceptor of the present invention include dip coating, spray coating, spinner coating, bead coating, Mayer-Par coating, blade coating, roller coating, and curtain coating. It can be done using For drying, it is preferable to dry to the touch at room temperature and then heat dry. Heat drying at 30℃
It can be carried out at a temperature of ˜200° C. for a time ranging from 5 minutes to 2 hours, either stationary or under blown air. The thickness of the coating layer formed by coating before drying is suitably 10 microns to 100 microns, preferably 20 microns to 60 microns.

Further, the composition of the present invention is applied on a substrate having a conductive layer. As the substrate having the conductive layer, materials that are conductive themselves such as aluminum, aluminum alloy, steel, zinc, stainless steel, vanadium, molybdenum, chromium, titanium, nickel, indium, gold, and platinum can be used. and other plastics (e.g., polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin) that have a layer formed by vacuum deposition of aluminum, aluminum alloy, indium oxide, tin oxide, indium oxide-tin oxide alloy, etc. , polyfluoroethylene, etc.), a substrate made of conductive particles (e.g. carbon black, silver particles, etc.) coated on plastic with a suitable binder, a substrate made of plastic or paper impregnated with conductive particles, or a conductive polymer. Grass, snacks, etc. can be used.

A subbing layer having barrier and adhesive functions can also be provided between the conductive layer and the photosensitive layer. The subbing layer is casein,
Polyvinyl alcohol, nitrocellulose, ethylene-
Acrylic acid copolymer, polyamide (nylon 6, nylon 66°, nylon 610, copolymerized nylon, alkoxymethylated nylon, etc.), polyurethane, gelatin,
It can be formed from aluminum oxide, etc.

The thickness of the undercoat layer is 0. lt to 5 microns, preferably 0.5 to 3 microns are suitable.

The photoconductive composition of the present invention can be used not only in photosensitive layers of electrophotographic photoreceptors, but also in solar cells and optical sensors.

Hereinafter, the present invention will be explained according to examples.

Example 1 A coating solution having the following composition was dip-coated onto an aluminum plate in a temperature control film thickness of 100 microns.

Coating liquid poly[ethylene glycol-CO-bis(hydroxyethoxyphenyl)furopane terephthalate]
2. Hydrazone of St example/161 1. Of Said Exemplification/%10 Bi IJ 1
7um salt 0.5F dichloromethane
30-Next, a photoreceptor was prepared by drying using a conventional method.

The electrophotographic photoreceptor prepared in this manner was statically charged with corona at 15 KV using Kawaguchi Denki's Seiden Copying Paper Tester ModetSP-428, held in a dark place for 10 seconds, and then exposed to an illuminance of 5 luX. The charging characteristics were investigated.

As for charging characteristics, the surface potential (vO) and the exposure amount (83 A) required to attenuate the potential (Vl6) when dark decayed for 10 seconds to % were measured. The results are shown in Table 1.

Furthermore, in order to measure the fluctuation of the bright area potential and dark area potential after one repeated use, the photoreceptor prepared in this example was
, 6hv corona charger, an exposure optical system having an illuminance of 15'/uX, a current device, a transfer charger, a static elimination exposure optical system, and a cleaner.

This copying machine is configured to produce an image on transfer paper as a cylinder is driven. Using this copier,
Initial light potential (Vl, ) and dark potential (Vo) and 5
Bright area potential (Vx, ) and dark area potential 5 after 000 uses
) was measured. The results are shown in Table 2.

Table 1 Vo: -530 volts. : -510 Volt E34 : 7,2/uxIlsee 2nd
Table (Bolt) (Bolt) (Bolt) (Bolt) 1
-540 -10 -490 -4
5 Examples 2 to 14 Electrophotographic photoreceptors were prepared in the same manner as in Example 1, except that the pyrylium salt shown in Table 3 was used in place of the BiIJ 17ium salt used in Example 1. did.

The charging characteristics and durability characteristics of each photoreceptor were measured in the same manner as in Example 1. These results are shown in Table 4.

Table 3 Examples Byrylium dye 2 Pyrylium salt with compound height (8) 3
Compound A (11) 4 Compound 4 (13) 5 Compound/16 (19) 6 Compound 4 (20) 7 Compound/% (28) I8
Compound, % (29) t9 Compound A
(31)' 10 compound/l6 (33) '11
Compound storage (a) r12
Compound, 46 (37) t13 Compound location (39) '14 Compound J4
6 (40) Table 4 - (1) (Volt) (Volt) (/ux-sse)2
-500 -470 9
．． 43 -550 -530
6.64 -560 -550
615 -480 -46
0 11.46 -490
-460 10.57 -580
-560 5.48 -5
60 -540 6.99
540 -530 7.010
-560 -540 7.
511 -570 -550
8.912 -590 -570
6513 -560 -
530 7.114 -580
-550 7.8 Table 4-(
2) (Bolt) (Bolt) (Bolt) (
bolt) 2 -. 510 -10
-530 -503 -570
-10 -520 -454 -5
70 -10 -510 -505
-490 -15 -440
-656 -4*'o -10-5
20-607-590-15-530-45 8-570-15-510-50 g -540-10-480-4510-5
70-10-510-50 11-580-10-590-55 12-600-15-540-50 13-560-15-510-60 14-590-10-530-55 Examples 15 to 54 The above implementation A photoreceptor was prepared in exactly the same manner as in Example 1 except that the hydrazone compound shown in Table 7 was used in place of the hydrazone compound used in preparing the photoreceptor of Example 1.

The charging characteristics and durability characteristics of these photoreceptors were investigated.
Table-(1) (Volt) (Volt) (/ux*5ec)1
5 4 (2) -550-5207,016,
,%(3) -520-5008,6174(4
) -580-5605,818fu(5)
-580-5905719/% (6) -57
0'-560 5.820 rot (7) -5
60-5706,121fu(8) -550-5
405,9224(9) -500-4809,
4234(1G) '-520-5008,8
24fu (11) -570-5606, 125fu (12) -540-5108626A (13)
-520-5008,0274(14)
-530-5007,5284(15)
-550-5407,029/% (16)
-560-5407,930A(17) -5
30-5158, 2314 (18) -580
-5605,632A (19) -560-5
505,9334(20) -570-550
8,634 associate (21) -540-520&73
5 4(22) -560-5408,0
364(23) -580-5706,637
/%(24) -550-5307,2384
(25) -500-47010,1394(
26) -510-49010,5404(2
7) -560-5309,1414 (2g)
-520-5108,742fu (29)
-540-5107,643/l6(30)
-530-5108,0447% (31)
-560-5507,045mu (32)
-540-5106,646/% (33) -
580-5705,047A(34)-56
0-5307,9484(35) -590-
5607,249fu(36) -520-49
09,250A(37) -550-5106
, 351 rot (3B) -589-560605
24(39) -560-5597,2534
(4G) -550-5208154/l6(
4t> -5to -4908, 7th
i Table-(2) (Bolt) (Bolt) (Bolt) (Bolt) 15
-560 -10 -510
-5016 -530 -10
-470 -5517 -590
710 -570 -3018
-580 -10 -560 -3
019 -590 -1! -5
60-3520-570-10-550-30 2!1 -560 -15 -54
0 -3022 -520 -10
-530 -5523 -54
0-Is-500-5024-590
-1s -57o -3025-54
0-10-500-55 26-530-15-480-35 27-550-10-540-35

Claims (1)

[Claims] A photoconductive composition containing a pyrylium dye and a hydrazone compound.