JPS5949544A - Electrophtographic organic receptor - Google Patents

Abstract

PURPOSE:To obtain superior characteristics of each of exposure sensitivity, wavelength, and deterioration resistance, by using a charge transfer layer made of a specified polyester, and a charge generating layers made of crystalline oxytitanium-phthalocyanine. CONSTITUTION:The charge transfer layer contains as a charge transfer agent an effective polyester component obtained from at least 80mol% 2,6-dimethoxy-9,10- dihydroxyanthracene of all the dihydroxy components, and at least 80mol% alpha,omega- dicarboxylic acid of all the dicarboxylic acids. The charge generating layer contains crystalline oxytitanium phthalocyanie as an effective component. Both layers are formed on a conductive substrate in the order to the charge generating and transfer layers. A barrier layer may be formed between the charge generating layer and the substrate in order to prevent lowering of charged voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor, and more specifically, a novel multilayer electronic photoreceptor in which a novel polyester is used as an active ingredient in a charge transfer layer and oxytitanium phthalocyanine is used as an active ingredient in a charge generation layer. This invention relates to photographic photoreceptors.

The purpose of the present invention is to provide excellent deterioration resistance (memory resistance) in addition to excellent exposure sensitivity characteristics and wavelength characteristics.
An object of the present invention is to provide an organic multilayer electrophotographic photoreceptor having the following properties.

The photoreceptor for electrophotography was invented by Carlson (USP-2
, 297, 691), many photoreceptors have been developed, and these are broadly classified into those using inorganic materials, those using organic materials, and those using composite materials of inorganic and organic materials. Particularly recently, research has been actively conducted on so-called multilayer organic photoconductors that use organic materials and have a multilayer structure.
643 or JP-A-Sho/l 9- ] 05536 proposes a combination of a pyrazoline compound and chlordian blue or squarylium, and Ricoh Technical Report 1980 (3) page 4 proposes 9-(4 -diethylaminostyryl)anthracene or N-methyl-N-
It has been shown that a combination of phenylhydrazono-3-methylidene-9-ethylnonorbazole and a bisazo compound is useful as an electrophotographic photoreceptor.

When these are actually used as photoreceptors for electrophotography, there are various performance requirements, such as deterioration resistance during repeated use over a long period of time, printing durability, and image stability. Therefore, active research is being conducted.

We have developed a polyester obtained from a dihydroxy compound containing 2,6-dimethoxy7-9,10-dihydroxyanthracene as its main component and a dicarboxylic acid containing α,ω-dicarboxylic acid as a photoconductor material for electrophotography. We have discovered that a multilayer electrophotographic photoreceptor containing crystalline oxytitanium phthalonanine as an active ingredient in a charge transfer agent and an active ingredient in a charge generation agent exhibits high visibility, photosensitivity, and memory resistance. This led to the completion of the invention.

In general, electrophotographic photoreceptors that use phthalocyanine pigments as a charge generating agent have relatively high sensitivity and have a wide photosensitive area, so they are expected to have a promising future. The significant drop in charging voltage is a major obstacle to practical application. In order to improve this drawback, a method of adding various modifying components to the binder of phthalocyanine pigments (for example, Japanese Patent Laid-Open No. 54-14
7838.56-67854.56-78841.56
-2249:3 etc.) Also, a method of providing a barrier layer between a conductive substrate and a photoconductor (Japanese Patent Laid-Open No. 53-76036
) have been devised.

However, although all of these methods are effective in preventing deterioration after repeated use several thousand times, the reality is that they still provide insufficient results after repeated use tens of thousands of times.

As a result of our intensive research aimed at developing an electrophotographic photoreceptor that uses phthalocyanine pigments as a charge generating agent, we found that the crystalline form of oxytitanium phthalonanine as a phthalocyanine was used as an active ingredient in the charge generating agent. , this was used as a charge generation layer, and 2,6-simethoxy9. ] Dihydroxy compound containing 0-dihydroanthracene as main component, α, ω
- A multilayer functionally separated electrophotographic photoreceptor using a polyester obtained from a dicarboxylic acid containing dicarboxylic acid as a main component and having this as a charge transfer layer will be developed very soon.
It shows high exposure sensitivity and wide wavelength range photosensitivity, and also has K4
Even after repeated use tens of thousands of times, no decrease in i'i voltage was observed, no increase in residual potential, and no decrease in sensitivity. discovered.

Very knowledgeable +7. ．． f”t(・Rusama(・Functional separation of multilayer systems 1.1; jj, 'iJ, j child'U;)'
When obtaining a C photoreceptor, the performance of the resulting photoreceptor is significantly influenced by the combination of the charge generation agent and charge transfer agent, in addition to the unique performance of each charge generation agent and charge transfer agent. In order to obtain an optimal photoreceptor, suitable compatibility of energy levels (ionization potential, electron affinity, etc.) between the charge transfer layer and the charge generation layer is required, and the present invention has investigated these combinations in detail. As a result, the present invention provides: a) 2,6-simethoxy9°10- as a charge transfer agent;
Charge transfer layer containing as active ingredients a polyester obtained from a dihydroxy compound containing dihydroxyanthracene as the main component and a dicarboxylic acid containing α,ω-dicarboxylic acid as the main component b) Crystalline oxytitanium phthalone as a charge generating agent An electrophotographic organic photoreceptor having a charge generation layer containing anine as an active ingredient, the charge generation layer and the charge transfer layer being laminated in this order on a conductive support, and a) 2 as a charge transfer agent.
,6-simethoxy9゜1D-dihydroquine/compound mainly composed of anthracene and α, (r)
~A charge transport layer containing as an active ingredient a polyester obtained from a dicarboxylic acid containing dinonorboxylic acid as a main componentb) A charge generation layer containing crystalline oxytitanium fucrocyanine as an active ingredient as a charge generation agentC) Having a single barrier layer and on the conductive support, a barrier layer, a charge generation layer,
This is an electrophotographic organic photoreceptor in which a charge transfer layer is laminated in this order.

The polyester whose main components are 2,6-simethoxy-9,10-dihydroxyanthracene and α,ω-dicarboxylic acid means that the dihydroxy component has at least 80%
It is a polyester obtained from a dihydroxy compound in which mo12% consists of 2,6-simethoxy-9,10-dihydroxyanthracene and at least 80 moQ% thereof in α,ω-dicarboxylic acid. The polyester produced has good solubility, moderate softening temperature, and good workability.
The α,ω-dicarboxylic acid is selected so as to have well-balanced properties such as high crystallinity and high concentration of anthracene skeleton. The α,ω-dicarboxylic acid preferably has 4 to 18 carbon atoms, more preferably 6 to 16 carbon atoms.
Most preferably, those having 8 to 14 carbon atoms are used.

The dihydroxy compounds and dicarboxylic acids other than the above-mentioned main components used herein refer to dihydroxy compounds such as 9,10-dihydroxyanthracene, hydroquinone, and bisphenol A, and dicarboxylic acids such as isophthalic acid and terephthalic acid.

In the charge transfer layer of the present invention, the above-mentioned polyester is used as an active ingredient of the charge transfer agent, and if necessary, other polymeric compounds such as polystyrene resin, acrylic resin, ketone resin, polycarbonate, polyurethane, silicone resin, etc. Although they are used in combination, they may be used alone or in combination of two or more. Further, the amount of the polyester of the present invention contained in the charge transport layer is small (both 6 owt
% or more is required. Then, this charge transfer layer is formed by applying a solution of a suitable solvent such as dichloroethane or trichloropropane and drying it to a thickness of 5 to 50 μm, preferably 10 μm.
The film is formed to have a thickness of ~20μ.

The charge generation layer provided below the charge generation layer contains crystalline oxytitanium fucrocyanine as described above as an active ingredient of the charge generation agent. As the crystalline oxytitanium phthalocyanine, one that gives a strong diffraction peak is preferably used. However, θ is the Bragg angle.

Such oxytitanium phthalocyanine can be synthesized in good yield by reacting O-phthalonitrile with a pyridinium salt of titanium tetrachloride or by oxidizing chlorotitanium phthalocyanine. Furthermore, in order to obtain the crystal structure as described above, the synthesized oxytitanium phthalocyanine can be treated with a solvent such as ebuluene, xylene, chloroform, dichloroethane, trichloropropane, etc. Furthermore, it is also possible to efficiently crystallize the amorphous oxytitanium phthalocyanine obtained by vapor deposition by treating it with the above-mentioned solvent. The oxytitanium phthalocyanine thus obtained can be used as a vapor-deposited film for the charge generation layer, or it can be finely pulverized in a ball mill and used as it is, or it can be used as an acrylic resin, styrene resin, polyester resin, polyamide resin, or polycarbonate. resin,
A binder such as polyvinyl alcohol can be solution-coated with a solvent to form the charge generation layer. The amount of the binder used in this case is not particularly limited, but it is used in an amount of 5 to 200 parts by weight per 100 parts by weight of oxytitanium phthalocyanine. The thickness of the charge generation layer at this time is preferably 0.02 to 5 .mu.m.

Furthermore, in addition to each of these layers, a barrier layer may be provided between the charge generation layer and the conductive support for the purpose of preventing a drop in charging voltage. - thin film of polyvinyl alcohol dispersion,
Alternatively, an alcohol-soluble polyamide membrane can be an effective barrier layer. In the case of zinc oxide-polyvinyl alcohol, add 10 to 3 parts by weight of zinc oxide to 100 parts by weight of polyvinyl alcohol to make a 1% by weight aqueous solution, thoroughly grind and mix in a ball mill to form a suspension, which has a dry thickness of 1 μm or less. to form a barrier layer. In addition to the zinc oxide-polyvinyl alcohol film plate, an alcohol-soluble polyamide film may be used as a barrier layer suitable for the photoreceptor of the present invention. As such polyamide, 6/
6.6-copolymerized nylon, 6/11-copolymerized nylon,
Copolymerized nylons such as 6/6, 6/11-copolymerized nylon are preferred, and these nylon resins are dissolved in methanol to a 10% by weight solution and have a dry thickness of 0,
Coat and dry to a thickness of 1 to 1 μm or less.

Furthermore, a protective layer can be provided on the charge transfer layer for the purpose of improving the abrasion resistance of the photoreceptor.

This protective layer is preferably made of, for example, nitrocellulose, polyurethane, polyamide, or the like.

The present invention will be explained below with reference to Examples.

Example 1 Oxytitanium phthalocyanine was deposited on an aluminum sheet with a thickness of 100μ at 10-' Torr to a thickness of 0 and 1
A deposited film of μ was obtained. The deposited film was dissolved in trichloropropane for 5 minutes.
The crystallization was completed by soaking for a minute. On top of this, 45 parts of polyester obtained from 2,6-simethoxy9,10-dihydroxyanthracene and dodecanedioic acid and 955 parts of trichloropropane were heated to 90°C to form a uniform solution, and heated so that the dry coating film had a thickness of 15μ. Coated. The characteristics of the produced photoreceptor were evaluated in the following manner.

Sensitivity: Kawaguchi Electric Paper Analyzer SP-428
The sample is negatively charged at -5.5 KV and irradiated with 20 lux light, and the half-reduction exposure sensitivity E 1/2 (1 ux-sec) is calculated from the time it takes for the charged voltage to decrease to 1/2.

For energy sensitivity, 0.3 μW/cm 2 light separated by a spectral filter is irradiated, and the half-reduced exposure energy sensitivity (μJ 7 cm 2 ) is determined.

Further, to evaluate the repetition characteristics, the sample was charged at -5.5 KV and a corona linear velocity of 20 m/min, and irradiated with 500 jux of light for 05 seconds. This operation takes 2.5 seconds/c'yc
After repeating le, the charged voltage, residual voltage,
Measure sensitivity degradation. The results are shown in the table below.

Example 2 A photoreceptor was prepared in the same manner as in Example 1 using a polyester obtained from tridecanedioic acid instead of dodecanedioic acid, and its characteristics were measured.

Example 3 Instead of the vapor-deposited film of oxytitanium phthalocyanine and oxytitanium cap of Example 1, a dispersion solution prepared by grinding and dispersing 1 part of oxytitanium phthalocyania together with 200 parts of chloroform in a ball mill for a day and night was applied to form a 0-thickness film. A photoreceptor was obtained by providing a charge generation layer with a thickness of .1μ. Its characteristics are shown in the table below.

Example 4 On an aluminum sheet with a thickness of 100μ, 5 parts of zinc oxide (manufactured by Kasei Optonics) and polyvinyl alcohol (saponification degree of 8
6 to 89%) was mixed and sufficiently dispersed with water in a ball mill to give a concentration of 1% by weight.
It was left under reduced pressure at ℃ overnight to form a coating film with a dry thickness of 1 μm. Thereon, a charge generation layer and a charge transfer layer were formed in the same manner as in Example 1 to obtain a photoreceptor. Its characteristics are shown in the table below.

[Brief explanation of the drawing]

FIG. 1 is an Xm diffraction diagram of crystalline oxytitanium phthalocyanine used as the charge generating agent of the present invention. Cause 1 0 Procedural amendment December 13, 1980 Kazu Wakasugi, Commissioner of the Japan Patent Office Failure 1, Indication of the case Patent application No. 159469/1982 2, Name of the invention Organic photoreceptor for electrophotography 6, Person making the amendment Case Relationship with / Patent applicant 1-1-2 Yurakucho, Chiyoda-ku, Tokyo (046) Asahi Dow Co., Ltd. Representative Rei Yumikura - 4, Agent Sanshin Building 204, 1-4-1 Yurakucho, Chiyoda-ku, Tokyo Room No. 501-2138 Tanai Patent Office 5, "Detailed Description of the Invention" column 6 of the specification to be amended, Contents of the amendment (1) "Photoconductor material" on page 6, line 18 of the specification is corrected to "photoconductive material". (2) Delete "as a phthalocyanine" in lines 5 and 6 of the same 5th sentence. (3) "Dihydroanthracene" on page 5, line 9 is corrected to "dihydroxyanthracene." (4) In the 5th negative 17th line of the same sentence, ``the decrease in'' is corrected to ``the decrease in '' as well. (5) On page 7, line 14, "and the" is corrected to "and in the dicarboxylic acid component." (6) “Provided under the charge generation layer” in the 9th negative 1st line of the same
IE amended to say that ``[charge transfer FiIJ)' is provided under M''. (7) Delete the phrase "for example" on page 9, lines 14-15. (8) “Amorphous” on page 9, line 18 of the same page is “low crystallinity”
I am corrected. . (9) “10-6” in the 20th line of No. 10 of the same is changed to “6-1”
0” and corrected. (10) “0,1 to 1μ or less” on the 11th negative 12th line
is corrected to "0.1~1μ". (11) 112D 1oth line and 16th line NorK, V
Let J be rk VJ]jE. (12) "1 copy" in lines 5 and 6 on page 12 of the same flute is corrected to "1 copy". . (10) On page 14, line 4, third line from the bottom, and second line from the bottom, ``Part J'' is changed to ``Dujou'', part.

Claims (1)

[Claims] (1) a) 2,6-Simethoxy9 as a charge transfer agent
゜A charge transfer layer containing as an active ingredient a polyester obtained from a dihydroxy compound containing 10-dihydroxyanthracene as a main component and a dicarboxylic acid containing α,ω-dicarboxylic acid as a product b) Crystalline oxy as a charge generating agent An organic photoreceptor for electrophotography, which has a charge generation layer containing titanium phthalocyanine as an active ingredient, and has a charge generation layer and a charge transfer layer laminated in this order on a conductive support. f21 a) 2,6-Simethoxy9 as charge transfer agent
゜A charge transfer layer containing as an active ingredient a polyester obtained from a dihydroxy compound containing IO-dihydroxyanthracene as a main component and a dicarboxylic acid containing α,ω-dicarboxylic acid as a main component b) Crystalline oxy as a charge generating agent C) A charge generation layer containing titanium 7-color cyanine as an active ingredient;
An organic photoreceptor for electrophotography in which a charge transfer layer is laminated in this order.