JPS63247757A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To satisfy all the requirements of good electrophotographic characteristics, high durability, stability against environmental conditions, and stability of solutions at the same time by using a specified polyetherketone resin as a binder resin for an electric charge transfer layer formed on a conductive supporting body, and a hydrazone compound for a charge transfer material. CONSTITUTION:The photoconductive layer to be laminated on the conductive supporting body is composed of a charge generating material and/or the charge transfer material, and the binder material contained in these materials containing at least one kind of polyetherketone resin having the structural unit represented by formula I or II, in which (m) is 0 or 1; Ar is a group of formula III; R is alkyl group; (n) is 0-2; X is one of formulae IV; and each of R' and R'' is independently H, methyl, ethyl, or phenyl. This polyetherketone resin has strong absorptions in the ultraviolet region and the short wavelength visible light region, and the light resistance of the photosensitive body is especially excellent when it is used for the binder resin of the charge transfer layer because it absorbs the ultraviolet rays and the short wavelength visible lights, and it is also superior in solubility in a solvent, and the stability of the solution.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a highly sensitive, highly durable, and highly productive electrophotographic photoreceptor having a photoconductive layer containing an organic photoconductive substance. It is.

(Conventional technology) Conventionally, electrophotographic photoreceptors include selenium and Cds.

Inorganic photoconductive materials such as zinc oxide are widely used.

In recent years, research on organic electrophotographic photoreceptors has progressed, and some of them have been put into practical use because they are non-polluting, have excellent flexibility, productivity, and have a wide range of material selection. A laminated electrophotographic photoreceptor has been developed which combines a charge generation layer that absorbs 1 cft and generates all charge carriers, and a charge transport layer thereon that holds charges and moves the generated charge carriers. Since then.

The performance of organic electrophotographic photoreceptors has improved dramatically.

In these laminated electrophotographic photoreceptors, [the charge generation layer is made of inorganic materials such as Se, Ss gold alloy Cds, Z
It is formed by vacuum evaporation of nO, etc. or by dispersing it in a binder resin, and is an organic type.

Phthalocyanines, azo pigments, squaryrium salts, azulenium salts, a! Formed by dispersing a charge-generating substance such as polycyclization sweetener into a vacuum source y# or a binder resin, 47'! :, as an organic type.

Charge-generating substances such as phthalocyanias, azo pigments, squaryrium salts, azulenium salts, and condensed polycyclic compounds with a vacuum source of 7II% or polyacrylate resins such as polyester, polystyrene, polyvinyl chloride, polymethyl methacrylate, and polyvinyl butyral. It is formed by being dispersed in a binder resin such as resin.

Max, im charge transport layer, generally, a charge transporting substance such as anthra7ane derivatives, oxadiazoles, pyrazoline compounds, styryl compounds, hydrazone compounds, stilbene compounds, etc. is used together with a film-forming resin. It is formed by dissolving it in a solvent and applying it using a suitable coating method. this is,
The auxiliary charge-transporting substance generally has a low molecular weight and has poor film-forming properties by itself.

Needless to say, the functions required of the charge transport layer include providing good electrophotographic properties (charging properties, sensitivity, low residual potential, etc.), but the charge transport layer is generally formed on the surface of the photoreceptor. To achieve this, various processes are applied to the photoreceptor, such as corona charging, toner development, transfer to paper,
Electrical, thermal, optical, mechanical durability such as cleaning, and stability against the environment (temperature, humidity) are required.

In addition, the coating liquid for forming the charge transport layer has good coating stability, can be controlled over a wide range of 4 degrees, satisfies the strictness constraints required by the coating method, and is compatible with coating equipment. It is required that there be few restrictions on

(Problems to be Solved by the Invention) Resins conventionally used as binder resins for charge transport layers include polycarbonate, polymethyl methacrylate, polystyrene, styrene-methyl methacrylate copolymer, polyarylate, polyester, and polysulfone. , styrene-butadiene copolymer, polyvinyl chloride, polysalt 1-hibinylidene, polyphenylene ether, etc., but the properties are insufficient and 6 717. It is difficult to apply and form as a solution. For example, polycarbonate resins and polyarylate resins have relatively good properties, but the resins themselves are difficult to dissolve in common solvents, and the solutions tend to freeze within a few days, making it difficult to produce photoreceptors. It was inconvenient for me. Further, when the photoreceptor is used repeatedly, the residual potential gradually increases, and good images cannot be obtained after about 25,000 sheets have been printed. In addition, when polymethyl methacrylate resin or styrene-methyl methacrylate copolymer is used, the solution is stable for more than 60 days, but the mechanical strength of the coating film is weak and after repeated use, scratches occur after about 5000 sheets. This causes streaks to appear in even one image, and the characteristics deteriorate under high humidity conditions. When polyester resin is used, the sensitivity is poor and I[! Fog occurs in the Il image. In the case of Example 7 using IL polysulfone (JP-A-57-189145) resin, the mechanical strength of the coating film was sufficient, but the solution began to become cloudy in about 20 days and became unusable.

As described above, no conventional binder resin has been found that simultaneously satisfies good electrophotographic properties, durability, environmental stability, and solution stability.

The object of the present invention is to provide a binder resin that simultaneously satisfies all of the functions required for these charge transport layers.

(Means for Solving the Problems) The present inventors have recognized the importance of the binder resin necessary for use in all-electrophotographic photoreceptors.
After thorough investigation into non-grade engineering plastics with excellent solution stability and good mechanical durability, we found that the following general formula (I) and ■ R and R" are independently -H, -〇 H1, -CtHs, @
) k *wasu. ] It was discovered that a polyetherketone polymer consisting of the structural unit represented by the following has particularly good properties as a binder resin, and the present invention was completed.

The ratio of the general formula units in the polyetherketone polymer Fi of the present invention is 1.0 to 0.1. General formula■The ratio of building units is 0.9
~0.

In the polyetherketone polymer of the present invention.

It has strong absorption in the visible and short wavelength regions, and when used as a binder in the charge transport layer, it absorbs ultraviolet rays and short wavelengths of 1 liter.
Because it absorbs visible light, the photoreceptor has particularly excellent light resistance. In addition, it has excellent dissolution properties against common media and solution stability.

When the entire charge transport layer is prepared using the above-mentioned polyetherketone resin gold, the reduced viscosity of the polyetherketone resin (
ηsp/C) is preferably 0.3 or more. Reduced viscosity is 0.
If it is less than 3, the film forming properties of the resin itself will be poor and a good coating film will not be obtained.

Examples of the polyetherketone resin of the present invention include:

Examples include those having the following mb return unit.

The polyetherketone of the present invention is obtained by preparing a mixture of a dihydroxy aromatic compound and an aromatic cibaride compound in a thermally stable polar solvent in the presence of an alkali.

100 to 350 CL: Can be synthesized by polycondensation at temperature D.

The usable aromatic cibaride compound is represented by the following first-order general formula.

(In the formula, 1m represents 0 or 1. Y represents Ct and F atom.) Preferred aromatic cybaride compounds include 4°4'-
Cyfluoropenzophenone, a,a'-cy/loropenzophenone, 4.4'-Sif0leusophthalophenone, 4.
Examples include 4'-difluoroterephthalophenone. The dihydroxy aromatic compound used in the synthesis of the polyetherketone of the present invention is represented by the following general formula.

(In the formula, R is an alkyl group, and n is an integer of 0 and 1.2.

R' Preferred examples of dihydroxy aromatic compounds include those of the first order.

When creating a charge transport layer using the polyetherketone resin of the present invention, the charge transport material is:

anthracene derivatives such as 2.6,9.10-tetraisopropoxyanthracene, oxadiazoles such as 2.5-bis(4-diethylaminophenyl)-1,3,4-oxadiazole m,1-phenyl- 3-(p-
pyrazoline derivatives such as diethylaminostyryl)-pyrazoline, and styryl compounds such as 4-(diethylamino)styryl-2-anthracene.

For a certain b, enamine derivatives such as dimethoxydiphenylacetaldehyde enamine can be used, but good results of 1% can be obtained by using a hydrazone compound represented by the following general formula (III).

[In the formula, R1 is a methyl group, a phenyl group, or a naphthyl group. (base). ] The hydrazone compound represented by the general formula (111) is.

For example, it can be easily obtained by condensing tIL-converted benzaldehyde and substituted hydrazine in a solvent, as shown in %Opening Publication No. 54-59145.

The solution of polyetherketone resin and hydrazone compound of the present invention is stable for more than 30 days.

The mechanical durability of the coating film is also extremely good, so it can be used in electrophotographic processes (charging, exposure, development, transfer, cleaning, and static elimination).
Even by repeating 50,000 times, the potential quality f of the bright and dark areas
1 is small, and there is no surface abrasion or scratches caused by rubbing, and the image does not change at all.

When producing the electrophotographic photoreceptor of the present invention, aluminum, copper, and nickel are used as the conductive coated body.

411 metals such as zinc, gold, indium, etc. can be used. Further, for the purpose of improving memory resistance, a zinc oxide layer or a methanol-soluble polyamide layer with a thickness of 1 μm or less may be provided on these conductive supports using polyvinyl alcohol as a binder.

The charge generation layer is well dispersed using a homogenizer, ultrasonic wave, ball mill, sand mill, etc. together with the binder resin and solvent in a total amount of 0.2 to 2.0 times the charge generation layer, and the dry thickness is 0.02 to 2.0 times. It can be formed by coating to a thickness of 5 μm or by vacuum deposition.

Charge transport no. is made of polyetherketone resin consisting of structural units represented by general formula (1) and I, and general formula (11).
1) Dissolved in the hydrazone f-hyde compound 'tM agent,
It is formed by coating and drying on the charge generation layer.

The ratio of hydrazone compound and polyetherketone resin is
It is preferable to use 50 to 200 parts by weight of the polyetherketone resin per 100 parts by weight of the hydrazone compound. As the solvent, chlorobenzene, dichloroethane, chloroform, salt rt methylene, tetrahydrofuran, etc. are used.

The thickness of the charge transport layer is preferably 5 to 30 μm.

The electrophotographic photoreceptor of the present invention can be used not only for electrophotographic copying machines, but also for laser printers, LED printers,
It can also be widely used in optical printers such as liquid crystal shutter printers.

(Example) The present invention will be explained below using examples.

Example 1 AtCLC2 obtained by sublimation purification! Na Hls
Chlorinated aluminum phthalocyanine 8 denoted by CL
Parts by weight and 563 parts by weight of chloroform are ground in a glass ball mill at room temperature for 10 hours. A coating solution was prepared by dissolving 8 parts by weight of a near-acrylic resin (Acrizo Ink A-801, manufactured by Dainippon Ink Co., Ltd.) in the obtained nine-dispersed ginseng.

Coating solution 7 obtained in this way was applied to copolymerized nylon (
Toshi CM4001)' dissolved in methanol to 1%
A liquid solution was prepared and applied by dip coating onto a 100 μm aluminum sheet to form a dry coating film of 0.8 μm.The solution was dip coated onto a substrate so that the dry film thickness was 0.1 μm.

Dry at 100C for 1 hour to form a charge generation layer. On top of this, 10 parts by weight of p-diethylaminobenzaldehyde (diphenylhydrazone).

Polyetherketone resin (reduced viscosity 0.87
) A bath solution consisting of 10 parts by weight and 72 parts of 1,2-dichloroethane was coated with a t-m cloth and vacuum dried to a dry film thickness of 15 μm.
Form a charge transfer layer of m and create a photoreceptor.

Example 2 A polyetherketone resin (reduced viscosity: 0.79) represented by the following structural formula was used as a binder resin for the charge transport layer.
A photoreceptor was prepared under the same conditions as in Example 1, except that it was used in Example 1.

Comparative Examples 1 to 5 As the binder resin of the charge transport layer, polycarbonate resin (Nipilon E-
2000, manufactured by Mitsubishi Gas Chemical Industries KK) (Comparative Example 1), polymethacrylic modified methyl (Delpet, manufactured by Asahi Kasei KK) (Comparative Example 2), polysulfone (Needel P1700)
, manufactured by UCC) (Comparative Example 5).
A photoreceptor was prepared under the same conditions as above.

Example 3 21.5-bis(
The photosensitive side was prepared under the same conditions as in Example 1, except that 4-diethylaminophenyl)-1,3,4-oxadiazole was used.

Example 4 A photoreceptor was prepared under the same conditions as in Example 1, except that 4-(diethylamino)styryl-2-anthracene was used instead of p-diethylaminobenzaldehyde (diphenylhydrazone) as the charge transport material. .

Examples 5 to 8 Disazo-drugs represented by the following structural formulas 31. Polyester resin (Pylon 200; manufactured by Toyobo) 1f, tetrahydrofura/96
A charge-generating pigment dispersion is obtained by pulverizing and mixing in a liquid chamber ball mill consisting of T. This dispersion was used in Example 1 and was dip coated onto a substrate so that the dry film thickness was 1 μm, and dried to form a charge generation layer. 1 Table 1 on top of this charge generation layer
A coating solution for forming a charge transport layer consisting of 10 parts by weight of a hydrazone compound, 10 parts by weight of a polyetherketone resin, and 72 parts by weight of 1,2-dichloroethane in the combination shown in is subjected to ischemia;
Vacuum drying to form a charge transfer layer with a dry film thickness of 17 μm,
A photoreceptor was created.

Example? Next, the coating solution for forming a charge transport layer prepared in each Example and Comparative Example was placed in a container and sealed, and a one-turn viscometer (E-type viscometer, type EL; manufactured by Toki Sangyo) was used to measure the viscosity. A friend that measures changes over time. The measurement results are shown in Table 2. As is clear from the results, in Example and Comparative Example 2, blood preparation 2
Although it can be used even after 0 days, in Comparative Examples 1 and 3,
After 3 and 20 days, the coating solution became cloudy with a gel ratio of 1.

becomes unusable.

Table 2 Change in viscosity over time (25C) Example 10 Characteristics of the electrophotographic photoreceptors prepared in Examples and Comparative Examples were evaluated using a 5P428 tester manufactured by Kawaguchi Electric. After corona charging at 5 KV, the surface potential was measured, and for the photoreceptors of Examples 1 to 4 and Comparative Examples 1 to 3, the photoconductor was charged with a light i of 3.84 μW/c1/l at 800 nm.
The half-reduced exposure energy E (1/2) (μJ/m) ft was determined from the time it took for one surface type position to decrease to 1/2 after i irradiation, and the surface potential VR was measured 1.3 seconds after irradiation. For Examples 5 to 8, the surface potential was similarly measured after corona charging, and the half-reduction exposure energy E (1/2) was determined from the time when the surface potential decreased to 172 after irradiation with 20 lux white tungsten light. (looks/sec) t-determined, and the surface potential VR't'' measured 1.3 seconds after irradiation.The measurement results ft are shown in Tables 5 and 4.

Table 5 Table 4 As is clear from the above results, the initial photoreceptor characteristics show sufficient performance.

Example 11 Next, photoreceptors t- and -5,6KV corona were prepared in Example 1.2 and Comparative Example 1.2. Electric, semiconductor laser (7
A durability test was carried out using an electronic 4-segment laser printer, which has an exposure process (90 nm), dry toner reversal development, toner transfer to plain paper, a cleaning process using a urethane rubber blade, and a static elimination exposure process. At this time, the 1L dark potential (v,'), laser exposure potential (Vl), and photoreceptor film thickness were evaluated.

The results are shown in Table 5.

Table 5 (Note) The unit is Vo, V is volt, and the film thickness is μm.

As is clear from Table 5, in Examples 1 and 2, even after repeated printing of 50,000 sheets, the decrease in film thickness was small and the change in potential was extremely small, so good images were obtained without any change. On the other hand, in Comparative Example 1.

Although the decrease in film thickness was not large, the increase in ■ was large, and good images could no longer be obtained after 25,000 sheets. In Comparative Example 2, the decrease in g thickness was large.

Scratches occur due to surface rubbing, and black streaks appear on the images after 5,000 copies.

(Effects of the Invention) According to the present invention, a specific polyetherketone resin is used as a binder resin in a charge transport layer, and a hydrazone compound is used as a charge transporting substance. By using #), good electrophotographic properties,
A highly durable electrophotographic photoreceptor can be obtained, and the coating solution used for forming the material does not need to be shipped.

High productivity can be achieved because it is stable and does not undergo temporary changes.

S Procedural amendment May 1, 1986

Claims (2)

[Claims] (1) The photoconductive layer laminated on the conductive support contains a charge generating substance and/or a charge transporting substance and the following general formula (I
) and (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) [In the formula, m is 0 or 1, Ar is ▲Mathematical formulas, chemical formulas, tables, etc. ▼ (R is an alkyl group, n is an integer of 0, 1, or 2, X is ▲ mathematical formula, chemical formula, table, etc.▼, -O-, -SO_2-,
▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼, R and R'' are independently -H, -CH_3
, -C_2H_5, ▲There are mathematical formulas, chemical formulas, tables, etc.▼
). ] An electrophotographic photoreceptor comprising at least one polyetherketone polymer having a structural unit represented by the following. (2) In a laminated electrophotographic photoreceptor that includes a conductive support, a charge generation layer, and a charge transport layer, the charge transport layer has the following general formulas (I) and (II) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ( I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) [In the formula, m is 0 or 1, Ar is ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (R is an alkyl group, n is 0, 1, 2 The integer, X, has a mathematical formula, chemical formula, table, etc.
▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
There are tables, etc. ▼, R and R'' are independently -H, -CH_3
, -C_2H_5, ▲There are mathematical formulas, chemical formulas, tables, etc.▼
). ] at least one type of polyetherketone polymer consisting of the structural unit represented by the following general formula (III
) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (III) [In the formula, R_1 is a methyl group, phenyl group or naphthyl group, R_2 and R_3 are hydrogen, methoxy group or ethoxy group, R_4 is a methoxy group, ethoxy group or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (R_5 and R_6 are methyl groups,
ethyl group, phenyl group, biphenyl group or phenoxyphenyl group). ] An electrophotographic photoreceptor comprising at least one hydrazone compound represented by the following.