JPS6259963A - Electrophotographic sensitive material - Google Patents

Abstract

PURPOSE:To provide the higher sensitivity in a semiconductor laser region by incorporating a specific org. pyrylium compd. into the titled material. CONSTITUTION:The pyrylium compd. expressed by the formula (R3 is H, halogen atom, (un)substd. alkyl, (un)substd. aryl, R1, R2, R4, R5 ar synonymous with R3 except halogen atom, H halogen atom, alkyl and aryl of R1-R5 may be respectively the same or different, X is an anion) is incorporated together with an org. photoconductive material into the photosensitive layer. Such pyrylium is added at about 0.01-10% by weight of the org. photoconductive material, for example, phenylene diamine deriv. etc. The sensitivity of the photosensitive body is thereby improved and the durability good against heat and humidity is thus obtd. The photosensitive body having the high sensitivity particularly in the wavelength region of a semiconductor laser is obtd.

Description

Detailed Description of the Invention "Field of Industrial Application" The present invention relates to a highly sensitive electrophotographic material mainly composed of an organic photoconductive substance, particularly an electrophotographic material exhibiting high sensitivity in the wavelength region of a semiconductor laser. .

"Prior Art" In recent years, electrophotographic systems using semiconductor lasers as light sources have been actively developed. Semiconductor lasers have great advantages such as being smaller and cheaper than gas lasers such as ie-Ne and being able to be directly modulated, but their oscillation wavelength is often 7 j Onm or more. Therefore, the number of photoreceptors used in this system is 7! It is necessary to have an absorption of Onm or higher and to exhibit high sensitivity, and various sensitizing agents are being developed. However, organic compounds that absorb in the long wavelength range are generally unstable with respect to heat and humidity, causing problems in manufacturing and handling, and furthermore, photosensitive materials made using them tend to deteriorate over time. There were many cases where the photoconductor's functional properties were lost when stored for a long period of time.

In addition, even if the main absorption is in this wavelength range, there are some that have small extinction coefficients or only exhibit low electrophotographic sensitivity, so the current situation is not necessarily satisfactory, and even higher sensitivity and higher durability are required. The development of electrophotographic photoreceptors is desired.

"Problems to be Solved by the Invention" A first object of the present invention is to provide an electrophotographic material containing an organic photoconductive substance and a pyrylium compound and having high sensitivity.

A second object of the present invention is to provide an electrophotographic photosensitive material that is durable against heat and humidity.

A third object of the present invention is to provide an electrophotographic photosensitive material having all of its main absorption in the oscillation wavelength region of a semiconductor laser and exhibiting high sensitivity.

``Means for solving all the problems'' That is, as a result of intensive research, the present inventors have solved all the above problems by producing an electrophotographic light-sensitive material containing at least one compound represented by the following general formula (I). I was able to solve it.

General formula (I) In the formula, R1, R2, R4, R5 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and R3 represents a hydrogen atom, a substituted or unsubstituted aryl group, and R3 represents a hydrogen atom, a substituted or unsubstituted alkyl group, and a substituted or unsubstituted aryl group. Indicates a substituted alkyl group, a substituted or unsubstituted aryl group. The hydrogen atoms and aryl groups of R, 2, 3, 4, and R5 may be the same or different. X represents an anion.

In addition, the preferable alkyl group of 1, R12, 几8, 几4, 几 is an alkyl group having carbon atoms/~it number,
Specifically, methyl, ethyl, n-propyl, 1so-propyl, n-butyl, 5ec-butyl, tart-butyl, n-amyl, n-hexyl, rhohefthyl, n-/
Nyl, n-)''7' syl, 2-ethylhexyl, fluoromethyl, chloromethyl, bromomethyl, trifluoromethyl, methoxymethyl, cyanomethyl, argylthiomethyl and the like.

Preferred aryl groups are those having up to t-21 carbon atoms, and specific examples include phenyl, tolyl, chlorophenyl, fluorophenyl, naphthyl, and the like.

Specific examples of the anion of X include R-chlorate,
Tetrafluoroborate, iodide, chloride,
Examples include bromide, sulfate, periodide, p-)luenesulfonate, and the like.

In the compound used in the present invention, a ter t-butyl group (hereinafter referred to as t
(denoted as ert-Bu group) plays the role of improving the overall stability and solubility of the compound. The phenyl group (hereinafter referred to as 2-group) introduced into the other biryllium ring is for setting the total main absorption to around 7rOnm.

R and -1-L play a role in finely adjusting the absorption maximum wavelength as desired.

Next, typical examples of the metal compound represented by the general formula (I) used in the present invention are shown below, but the present invention is not limited thereto.

Compound-(I) Compound-) α,e Compound-(3) αQe Compound-(4) CIU,” Compound-(5) C1,o40 Compound-(6) F4e Compound-(7) α04G Compound-(8 ) α04e Compound-(9) Compound-(I0) α(,14e Compound-(I1) Cl(J4e Compound-(I2) α04e Compound-(I3) α04e Compound-(I4) 04e Compound-(I5) Ct( J e compound - (I6) PU e The bi-IJ liu compound used in the present invention is used to sensitize the organic photoconductor, and the amount varies depending on the type of organic photoconductor, but in general, The photoconductor has an it ratio of 1 to 100, preferably 0.
．． It ranges from 7% to 30chi.

Examples of the pyrylium compound used in the present invention include Y.

The 2-di-tert-butyl-[mu]m methylpyrylium salt is reacted with an equimolar amount of l-anilino-3-7enyliminozoloben, followed by a further equimolar co-coat.

Obtained by reacting with Otsu-diphenyl-Hiro-methylpyrylium salt. This reaction is preferably carried out in acetic anhydride in the presence of a base such as IJum (the first step is acetic anhydride and the second step is acetic anhydride). The amount of acetic anhydride in the first step reaction is .

t-tert-butyl≠-methylpyrylium salt/
For 2/~ko0 dew t1 preferably 2~i.

It is 11t. What is the reaction temperature? It is carried out from Q° to reflux temperature, preferably around loo'c. The reaction time is 7 minutes to 1 hour, preferably 70 minutes to 30 minutes. It is also possible to isolate the intermediate prior to carrying out the second step reaction. The intermediate can be isolated by diluting the first-stage reaction mixture with an organic solvent such as total ether, which is a poor solvent for the intermediate, and crystallizing the intermediate. In the second stage reaction, it is preferable to use anhydrous sodium acetate in an amount equivalent to 2 to 3 moles per mole of co,6-diphenyl-l-methylpyrillicum salt. The reaction time and reaction temperature are the same as those in the first stage.

Next, typical methods for synthesizing pyrylium compounds used in the present invention will be shown using synthesis examples. In addition, λ,
-Butyl≠-methylpyrylium salt, t-diphenyl-μm methylpyrylium salt is available from Liebigs Annalen der Hemie (Liebigs Annalen der Hemie).
der Chemie ) 62! , 7≠(I517
P)K Synthesized by the method described.

Synthesis row-1 (Synthesis of compound-(I)) Fuji tert-butyl-≠-methylpyrylium verchlorate (J, 07f, 0,0/mol), /-
Anilino-3-phenyliminopropene (j, 22
f! , 0.0/mol) f Mix well, acetic anhydride j m
lf added. After heating the mixture ft10o0C 10
Stir for 1 minute, then λ, t-diphenyl≠-methylpyrylium barchlorate (J, 447y, 0,0/m0
I), anhydrous sodium acetate (/, 72.0.02um
mol) f was added, and stirring was continued for an additional 30 minutes. After cooling to room temperature, 0 ml of ether was added to the reaction mixture, and stirring was continued under ice cooling. The precipitated crystals t-p were taken, washed with water, dried, and then recrystallized from methanol to give compound (I) total melting point (decomposition point).
Obtained as red-purple crystals of /12-/It'C. (Yield λ, ≠ P2, Yield aS Chi) Elemental analysis Molecular formula C35H37010gCHα Calculated value @) 7/, Jt &, 3J /y,
02 Experimental value (%) 7/, lJ t, Jko Otsu, /2 Synthesis example-2 (Synthesis of compound-(3)) Tin tetrachloride (Iou, Co?, OouQmol), Piparoyl chloride (A, 4f % 0.rOmo while stirring under water cooling.
,11%0. Hiroshi #mori'fc was dropped and reacted. After the dropwise addition was completed, stirring was continued for 1 hour, and then the reaction mixture was poured into ice water containing toy perchloric acid with vigorous stirring, and stirring was continued for an additional 7 hours. Collect the precipitated solid,
Ethyl acetate/, recrystallized with 20 Mt-26-tar
t-Butyl-≠-ethylpyrylium verchlorate was obtained as white needle-like crystals with a melting point of 1 tro-/bu'c.

(Yield λ, jll, yield 23./chi) Elemental analysis Molecular formula C□5H2505α, CI (α Calculated value (chi) zt, iot 7.rr ii, or
Experimental value (91;) 13.5P0 7. rbu //,
(72 Next, the above pyrylium salt and J,4-diphenyl-μ
By performing the same operation as in Synthesis Example -/ using m-methylpyrylium verchlorate, compound - (3) was obtained with melting point λ3.
Obtained as greenish-gold crystals at 39°C.

Original X analysis Molecular formula C36H3,06c1! ICHα Calculated value (%) 7/, 69 t,! 2 j, rl
r experimental value (→ 71.4Al t, j3 r,
20 Synthesis Example-3 (Synthesis of Compound-(8)) Anhydrous T)iF(I
n-butyl lithium (7.7M hexane solution 3.11%) was added dropwise to the solution (7.7M hexane solution) to cause a reaction.

After 1 hour, the reaction mixture was poured into 10 x 1 tt% aqueous perchloric acid solution, the precipitated solid was collected, dissolved in a small amount of methylene chloride, reprecipitated in ether, and all the precipitated yellow solids were dried.

(λ,6-diphenyl-J-n-propylbi IJ IJ
Next, the crude crystals of the above pyrylium salt and λ, t-tert
-7" Compound-
(8) was obtained as reddish-gold crystals of 6C with a melting point of 233-23.

Elemental analysis Molecular formula C38H4306α1Cd
α Calculated value (%) 72. JI t, r7 j,
tλ experimental value (%) 72.2/ Otsu, tr s,
The improved electrophotographic material of the present invention comprises at least a support and a photosensitive layer.

The support used in the present invention requires conductive treatment. Specific conductive treatments include aluminum, gold,
Method of vapor depositing metals such as baladium and indium,
Alternatively, a method of vapor-depositing metal oxides such as In, 03, SnO Examples include a method of dissolving and applying it together with a polymer, and a method of applying an acetonitrile solution of copper iodide.

As the organic photoconductive substance used in the electrophotographic light-sensitive material of the present invention, many conventionally known organic photoconductive substances can be used.

Examples of polymers include the following:

(I) Polyvinyl carbazole and its Fat conductor, (2) Special Public Showa 4t! -/rt741- Publication, Special Publication Sho≠
Polyvinylpyrene, polyvinylanthracene, polyλ-vinyl-≠-(4c/
)) tylaminophenyl)-yo-phenyl-oxazole, vinyl polymer of poly-3-vinyl-N-ethylcarbazole, (3) polyacenaphthylene and polyisodene described in Japanese Patent Publication No. Sho μJ-/9/P3 (4) Condensation of pyrene-formaldehyde resin, brompyrene-formaldehyde resin, ethylcarbazole-formaldehyde resin, etc. described in Japanese Patent Publication No. Shojt-/Jri≠Q Publication, etc. Resin, (5) Tokukaisho! Ichita ore3 and Tokukai Sho Taro/
Various triphenylmethane polymers described in A/JRQ publication.

In addition, the following low-molecular weight products can be used successfully.

(6) Triazole derivatives described in U.S. Patent No. J//2/7 and the like; Oxadiazole derivatives, (8) Japanese Patent Publication No. 3, even though they are described in the specification of No. A7, etc.
Imidazole derivatives described in Publication No. 7-14094 etc., (9) US Patent No. 36/! u02, same number 31202r
y issue, 31412!1A44i4;,%Kosho4'r-
rzr, special public Shoj/-10 de r3, special public Shoj/-F
j2u≠ issue, Tokukaisho! ! -1710! No., Tokukai Akira! 1≠7≠r issue, JP-A No. 411-101467, JP-A-Sho!
! r-/Jj'trij3, Tokukai Sho! Otsu-3 Polyarylalkane conductor described in Otsu tjA specification, gazette, etc., αQ U.S. Patent No. 3iro'yλri No. 3, U.S. Patent No. U2
7174At, JP-A Showrz-rrota, JP-A Showz
Issue s-rro4, Tokukai Sho≠2-10! ! No. 37, JP-A-13-! No. 6 to 10, Tokukai Sho lt-100! / issue, Tokukai Akira! T-41/μ/ issue, Tokukai Shoj7-μ ≠! issue,
Tokukai Akira! ≠-/l Kobu No. 37, Tokukai Shoj! -7≠! ≠6
Pyrazoline derivatives and pyrazolone derivatives described in the specification, publication, etc., α◇ U.S. Patent No. 3t/! ≠Oa specification, Tokuko Sho r/
-1 oiot issue, % Kaishoj! -r3443! No., Tokukai Akira! μm1ior3 issue, JP-A-Kai J≠-//ヂ? 2! issue,
Phenyldiamine derivatives described in Japanese Patent Publication No. 6-377, Japanese Patent Publication No. 4Ly-2rJJ4, publications, etc. (b) U.S. Patent jj & 7μyo No. 0, Kokosho Powder ≠ 2-3j7
No. 02, West German Patent (DAS) //10zir, U.S. Patent No. 3110703, U.S. Patent No. 3 uOJ? No. 7, U.S. Patent No. 3, U.S. Patent No. 20, U.S. Patent No. ≠ 2321
Oj No., U.S. Patent No. ≠/7jri No. 47, U.S. Patent No. 0
Issue /237, Tokukai Sho 1! -/Hiroshi 442so issue, JP-A-//ri 732, special public Sho 3ter, 27!77,
Arylamine derivatives described in JP-A No. 2241-37 and publications, (to) amine-substituted chalcone derivatives described in U.S. Pat. No. 3,124,101, α→ U.S. Patent No. 3! ≠Koj≠N,N-bicalpadil derivatives described in the specification of No. z etc. (to) Oxazole derivatives described in the specification of US Pat. No. 32!7203 etc., (7) JP-A-14-47-1. Styryl anthracene derivatives described in JP-A No. 23μ, etc., fluorenone derivatives described in JP-A No. 0137, U.S. Patent No. 3777≠42, JP-A-Sho! μ-! No. 3 (corresponding to U.S. Patent No. 41/jO?I7), JP-A-1J-! 20 Otsu No. 3, Tokukai Sho 1! - Yoko o6≠ issue,
Tokukai Akira! ! -≠No. 6760, Tokukai Sho! ! −♂j≠Pj issue, Tokukai Akira! 7-//J! No. 0, JP-A-Sho J-7-/4#7
4C, hydrazone derivatives disclosed in JP-A No. 7-6≠Hari, etc.
No. JP-A-Shojj-72≠! No. O (US Patent Law, 2≦j
,? No. 90), U.S. Patent ≠, 04L7. ? Examples include benzidine derivatives disclosed in Kou No. 2 specification and the like.

These organic photoconductive substances are preferably used in the photosensitive layer in a weight range of O to F2.

When the organic photoconductor is a low-molecular compound, a high-molecular compound having appropriate film properties can be used as a total binder. Specifically, polyamide, polyurethane, polyester, epoxy resin, polyketone, styrenic polymer and copolymer, poly-N-vinylcarbazole, polycarbonate, polyester carbonate, polysulfone, vinyl chloride resin, vinylidene chloride resin, vinyl acetate resin. , various polymeric compounds such as acrylic resin. When the organic photoconductor is a polymer compound,
Although it has film properties by itself, the above-mentioned polymer compound may be added if necessary.

The amount of binder added varies depending on the type of organic photoconductor, but in the case of a low-molecular organic photoconductor, it is desirable to use jO-200% by weight relative to the organic photoconductor. When the organic photoconductor is a polymer, it is desirable to use /%-jt'0chi.

A chemical sensitizer can be used in the recording material of the present invention, and examples of the chemical sensitizer include electron-withdrawing compounds such as trinitrofluorenone, chloranil, and tetracyanoethylene; No., JP-A-Shojl-10λ
Compounds described in No. λ3 etc. can be mentioned.

The electrophotographic material of the present invention may contain known structure agents, plasticizers,
Gold, such as dyes and pigments, can be contained within a range that does not impair the properties of the electrophotographic material of the present invention.

Cyanoethyl cellulose, nitrile rubber, as reinforcing agents
Polycarnate of bisphenol A, linear polyester styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, etc. can be used. As a plasticizer, chlorinated biphenyls, epoxy resins, triphenylmethane compounds, coumaron resins, low molecular weight xylene resins, etc. can be used.

In addition, the electrophotographic light-sensitive material of the present invention includes a special plasticizer as described in Japanese Patent Publication Akihirota≠≦λ43,
Silane coupling agent, curing catalyst and/or crosslinking agent described in Japanese Patent Publication No. Sho J7-15Fμ23, Japanese Patent Publication No. Sho, ri-
rroko! The fluorine-containing surfactant described in Japanese Patent Publication No. Sho J7-/Riko No. 2μ, the Lewis acid described in Japanese Patent Publication No. Sho 17-/2712, etc. can all be contained.

When preparing the electrophotographic light-sensitive material of the present invention, a polymeric organic photoconductor, a solvent such as benzene, toluene, xylene, chlorobenzene, dichloromethane, dichloroethane, trichloroethane, cyclohexanone, tetrahydrofuran, dioxane, etc., and a mixed solvent thereof are used to prepare the electrophotographic light-sensitive material of the present invention.
A solvent that dissolves or disperses both the sensitizing dye and optionally added components can be used.

The photosensitive material according to the present invention can be obtained as follows.

In order to make a photosensitive material, a photoconductive substance, PIIJ of the present invention is used.
+) Rum-based compound and all components to be added as necessary are dissolved or dispersed in a solvent in the desired ratio and coated on a conductive support (coated and dried, or the above components are melt-coated on a conductive support. Alternatively, the photosensitive thin film can be prepared from a whole solution or by a melt extrusion method to form a self-supporting film.

Further, during coating, all known coating surfactants can be included in the coating solution.

The electrophotographic material of the present invention may have a surface protective layer.

An example of the surface protective layer is a layer of a binder resin containing fine particles. Binder resins used include polyester carbonate, polysulfone, polyether, polyester, polycarbonate, polyamide, polyimide, polyurethane, acrylic ester polymer and copolymer,
Methacrylic acid ester polymers and copolymers, styrene resins, polyvinyl acetals, polyvinyl carbazole, vinyl chloride resins, vinyl chloride resins, chlorinated polyolefins, vinyl acetate resins, aloxide resins, Naka-7lene resins, Kent resins, Examples include, but are not limited to, celluloses. These resins may be used alone or in combination.
More than one species can be used in combination.

Various types of fine particles can be used as the fine particles. For example, inorganic insulating fine particles such as silica, calcium carbonate, mica, clay, and boron nitride, metal oxides such as titanium oxide, aluminum oxide, magnesium oxide, zinc oxide, tin dioxide, and bismuth oxide, zinc stearate, and calcium stearate. Examples include, but are not limited to, long-chain organic acid metal salts such as zinc laurate, organic fine particles such as polypropylene, polyethylene, polyamide, polyvinylidene heptadide, and polytetrafluoroethylene. Among these fine particles, silica, aluminum oxide, and titanium oxide, which are particularly easily dispersed, can be preferably used.

The electrophotographic light-sensitive material of the present invention may optionally include K, intermediate gold film, etc. for various purposes (for example, to improve adhesion, etc.) between the support and the photosensitive layer, or between the photosensitive layer and the surface protective layer. It's okay to go.

The electrophotographic material of the present invention may be provided with a layer on its back surface for improving all the properties such as slip properties, charging properties, anti-blocking properties, and antihalation properties.

"Example" Examples of the present invention are shown below, but the present invention is not limited thereto.

A photosensitive solution 1 having the above composition was prepared, and then coated on a polyethylene terephthalate film having a thickness of 100 μm, which had an entire vapor-deposited film of indium oxide, using a wire parr and dried. An electrophotographic film was obtained having a photoconductive layer with a thickness r and a diameter of 1 μm. As shown in FIG. 1, this film has an absorption maximum within the oscillation region of the semiconductor laser (71r j nm).

Next, the obtained electrophotographic film was tested in a copy paper tester 5p-
Using a 4A cot (manufactured by Kawaguchi Denki ■), +7. ! It was corona-charged with KV, and then subjected to W heating with monochromatic light of 7rJnm to examine the electrophotographic characteristics and sound.

The characteristic charge retention ability was determined by measuring the total potential 40 seconds after corona charging in a dark place and determining the residual rate (%) of the initial potential.

As for the sensitivity, the potential before exposure is optically attenuated by exposure 1t (E5o), which becomes //2, and exposure amount (E,) which becomes //10.

) was sought.

The charge retention force shows a good value of 20%, and the sensitivity is tata e r g/ at the electric field strength o, r/X10 v/nt.
1yx2(E5o) ~t lAter g/m2
(E9o) and extremely high sensitivity.

Also, tungsten light (4A1uX) as a light source? When used, charge retention force is 5P0chi, E5゜column 1ux-sec
,E. /f71ux-sec (electric field strength 0, !≠X
/ (7' V / OR), which shows a good value.

Next, the above electrophotographic film 2jo c'c, to% H
After being left for KIO under the following conditions, absorption maximum and electrophotographic properties were examined, and almost no change was observed.

Example 2 Compounds (I), (3), and (8) of the present invention were used in the same manner as in Example 2 to obtain electrophotographic films. Table 1 shows the results regarding absorption maximum and electrophotographic properties of each film.

As is clear from Part 1, all of these films have an absorption maximum within the oscillation region of the semiconductor laser and have good electrophotographic sensitivity. Next, cholera 0 film t
-j o 'C, r Oc4 When the above-mentioned properties were measured after being left under RHtD conditions for IO weeks, there was almost no change from the table -/.

[Brief explanation of drawings]

FIG. 1 shows the absorption spectrum of the electrophotographic film of Example 7 in the visible to near-infrared region.

Claims (1)

[Scope of Claims] An electrophotographic light-sensitive material comprising an organic photoconductive substance and at least one compound represented by the following general formula (I). General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ In the formula, R_1, R_2, R_4, R_5 represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and R_3 is hydrogen atoms, halogen atoms,
Indicates a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. R_1, R_2, R_3, R_4
, R_5's hydrogen atom, alkyl group, and aryl group may be the same or different. X represents an anion.