JP4250275B2 - Electrophotographic photosensitive member, process cartridge, and electrophotographic apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrophotographic photosensitive member, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member, and more specifically, an electrophotographic photosensitive layer containing a polyester resin composed of a specific dicarboxylic acid component. The present invention relates to an electrophotographic photoreceptor excellent in characteristics and image stability due to repeated use, and particularly excellent in abrasion resistance when contained in a surface layer, and a process cartridge and an electrophotographic apparatus having the electrophotographic photoreceptor.
[0002]
[Prior art]
In the electrophotographic method, as shown in U.S. Pat. No. 2,297,691, the electrical resistance changes depending on the dose received during image exposure, and in the dark, a photoconductive film comprising a support coated with an insulating material. Uses a functional material. Basic characteristics required for electrophotography using this photoconductive material are (1) that it can be charged to an appropriate potential in a dark place, (2) there is little potential dissipation in the dark place, and (3) light. For example, the charge can be quickly dissipated by irradiation.
[0003]
Conventionally, as an electrophotographic photoreceptor, inorganic photoreceptors having a photosensitive layer mainly composed of an inorganic photoconductive compound such as selenium, zinc oxide and cadmium sulfide have been widely used. However, these satisfy the above conditions (1) to (3) but are not necessarily satisfactory in terms of thermal stability, moisture resistance, durability and productivity. In order to overcome the disadvantages of inorganic photoreceptors, electrophotographic photoreceptors based on various organic photoconductive compounds as main components have been actively developed in recent years. For example, US Pat. No. 3,378,851 discloses a photoreceptor having a charge transport layer containing triallyl pyrazoline, US Pat. No. 3,871,880 discloses a charge generation layer comprising a derivative of perylene pigment, and a condensate of 3-propylene and formaldehyde. A photosensitive member comprising a charge transport layer comprising, for example, is known.
[0004]
Further, the organic photoconductive compound can freely select the photosensitive wavelength range of the electrophotographic photosensitive member depending on the compound. For example, in the case of an azo pigment, Japanese Patent Laid-Open Nos. 61-272754 and 56-167759 are disclosed. JP-A 57-19567 and JP-A 61-228453 disclose compounds having sensitivity up to the infrared region. . Among these materials, those showing sensitivity in the infrared region are used in laser beam printers (hereinafter abbreviated as LBP) and LED printers that have made remarkable progress in recent years, and the frequency of demand thereof has increased.
[0005]
Electrophotographic photoreceptors using these organic photoconductive compounds may be used as function-separated photoreceptors in which a charge transport layer and a charge generation layer are laminated in order to satisfy both electrical and mechanical properties. Many. On the other hand, as a matter of course, the electrophotographic photosensitive member is required to have sensitivity, electrical characteristics, and optical characteristics according to the applied electrophotographic process.
[0006]
In particular, in electrophotographic photoreceptors that are used repeatedly, electrical and mechanical external forces such as corona or direct charging, image exposure, toner development, transfer process and surface cleaning are directly applied to the surface of the electrophotographic photoreceptor. , Durability against them is also required.
[0007]
Specifically, durability against electrical deterioration due to ozone and nitrogen oxides during charging, and mechanical deterioration such as surface wear or scratches due to discharge during charging and rubbing of the cleaning member is required. Yes.
[0008]
Electrodegradation as an electrophotographic characteristic is particularly a phenomenon in which carriers are accumulated in a portion irradiated with light and a potential difference is generated with a portion not irradiated with light, which is called a photo memory. . Moreover, the electrical deterioration as the film strength includes, for example, deterioration due to discharge of the resin forming the surface layer.
[0009]
Regarding mechanical deterioration, in particular, organic photoreceptors, which are often materially soft, unlike inorganic photoreceptors, have poor durability and are highly desired to improve durability.
[0010]
Polycarbonate resin having bisphenol A as a skeleton is attracting attention as a resin that is often used for the surface layer and has good wear resistance and electrical properties. However, it does not solve all the above-mentioned problems. It has the following problems.
[0011]
(1) These solvents are poor in solubility, exhibit only good solubility in a part of halogenated aliphatic hydrocarbons such as dichloromethane and 1,2-dichloroethane, and these solvents have low boiling points. When the photoconductor is produced using the coating solution prepared in (1), the coated surface is likely to be whitened. It also takes time to manage the solid content of the coating liquid.
[0012]
(2) Solvents other than halogenated aliphatic hydrocarbons are partially soluble in tetrahydrafuran, dioxane, cyclohexane, or mixed solvents thereof, but the solution gels in several days. It is not suitable for photoconductor production due to poor properties.
[0013]
The solution stability mentioned in the above (1) and (2) can be solved by using a polycarbonate Z resin having a bulky cyclohexylene group as a polymer structural unit or by copolymerizing with bisphenol Z or bisphenol C. I came.
[0014]
Regarding the improvement of strength against mechanical deterioration, Japanese Patent Application Laid-Open No. 5-113671 uses a polycarbonate having a specific structure having a weight average molecular weight of 150,000 or more, or Japanese Patent Application Laid-Open No. 56-135844 discloses a product. It is disclosed that a significant improvement in wear resistance was observed by using a polyarylate resin marketed under the name “U-polymer” as a binder. However, a resin that is resistant to mechanical deterioration is likely to be scratched even if the wear resistance is improved. There's a problem.
[0015]
With regard to improvement in strength against electrical deterioration, it has been proposed to prevent deterioration of materials by adding an additive such as an antioxidant to the photosensitive layer (Japanese Patent Laid-Open No. 57-122444, Japanese Patent Laid-Open No. 57-122444). No. 58-120260, JP-A 61-156131 and JP-A 62-105151). However, the addition of a low molecular weight antioxidant has still insufficient points such as reduced mechanical wear resistance and charge trapping.
[0016]
Accordingly, an object of the present invention is to provide an electrophotographic photosensitive member having excellent mechanical and electrical wear resistance and capable of supplying high-quality images over a long period of time, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member. There is.
[0017]
[Means for Solving the Problems]
That is, the present invention provides an electrophotographic photoreceptor having a photosensitive layer on a support, wherein the photosensitive layer is a dicarboxylic acid component represented by the following formula (1-1) or (1-2) or an ester-forming derivative thereof: An electrophotographic photoreceptor comprising a polyester resin comprising a diol component represented by any of the following formulas (2) to (4) .
[0018]
[Chemical formula 5]
[0019]
[ Chemical 6 ]
[0020]
(In the formula (2), Z represents a single bond, —O—, —S—, an alkylene group or a cycloalkylene group which may be substituted, and R _{1 to} R ₈ are each a hydrogen atom, a halogen atom, or a substituted group. And each represents an alkyl group or an aryl group, and R ₉ and R _{10 each} represent a single bond or an optionally substituted alkylene group or oxyalkylene group.)
[0021]
[ Chemical 7 ]
[0022]
(In the formula (3), R _{11 to} R ₁₄ represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms which may be substituted, and R ₁₅ and R _{16 each} represent an alkylene having 1 to 5 carbon atoms which may be substituted. Group.)
[0023]
[ Chemical 8 ]
[0024]
(In the formula (4), R _{17 to} R _{20 each} represent a hydrogen atom, a halogen atom, or a silyl group, an alkyl group or an aryl group, each of which may be substituted, l represents an integer of 2 or more, and m represents 0 or more. Indicates an integer.)
[0025]
Since the electrophotographic photosensitive member of the present invention has high mechanical and electrical wear resistance and high transparency, it has excellent durability, high electrical sensitivity and low photo memory.
[0026]
The present invention also provides a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Although the specific example of the dicarboxylic acid used for this invention is shown, it is not limited to these.
[0028]
[Chemical 9 ]
[0029]
Examples include 1,4-cyclohexanedicarboxylic acid of Structural Unit Example 1-1, 1,3-cyclohexanedicarboxylic acid of Structural Unit Example 1-2, and mixtures thereof. Moreover, the ester-forming derivative | guide_body of structural unit example 1-1, 1-2, and also a mixture thereof are mentioned.
[0030]
The polyester resin, which is a polymer used in the present invention, has a dicarboxylic acid component represented by the formula (1-1) or (1-2) or an ester-forming derivative thereof with a diol and an ester exchange method or a direct polymerization method. An appropriate method can be selected from known methods such as a combination method, a solution polymerization method, and an interfacial polymerization method. Moreover, a conventionally well-known method can be used also about reaction conditions, such as a polymerization catalyst in that case. Of these, the direct polymerization method is preferably used.
[0031]
Examples of the ester-forming derivative include, but are not limited to, acid anhydrides and chlorides of dicarboxylic acids represented by the following formula (1-1) or (1-2).
[0032]
[Chemical formula 10 ]
[0033]
A polyester resin using a dicarboxylic acid having an alicyclic hydrocarbon residue is superior in solubility to those using an aromatic dicarboxylic acid, and further has excellent electrical sensitivity and wear resistance.
[0034]
Next, Examples of the diol component used in the present invention, Ru is indicated by any one of the following formulas (2) to (4).
[0035]
[Chemical Formula 11 ]
[0036]
(In the formula, Z represents a single bond, —O—, —S—, an alkylene group or a cycloalkylene group which may be substituted, and R _{1 to} R _{8 each} represents a hydrogen atom, a halogen atom or an optionally substituted group. An alkyl group or an aryl group, R ₉ and R _{10 each} represent a single bond or an alkylene group or an oxyalkylene group which may be substituted.
[0037]
[Chemical formula 12 ]
[0038]
(In the formula, R _{11 to} R ₁₄ represent a hydrogen atom and an optionally substituted alkyl group having 1 to 4 carbon atoms, and R ₁₅ and R ₁₆ represent an optionally substituted alkylene group having 1 to 5 carbon atoms. .)
[0039]
[Chemical 13 ]
[0040]
(Wherein R _{17 to} R _{20 each} represent a hydrogen atom, a halogen atom, or an optionally substituted silyl group, alkyl group or aryl group, l represents an integer of 2 or more, and m represents an integer of 0 or more. .)
[0041]
In the formulas (2), (3) and (4), examples of the halogen atom include a fluorine atom, a chlorine atom and a bromine atom, and examples of the alkyl group include a methyl group, an ethyl group and a propyl group. Examples include methylene group, ethylene group and isopropylene group, oxyalkylene group includes oxymethylene group, oxyethylene group and the like, and aryl group includes phenyl group, naphthyl group and anthryl group, Examples of the arylene group include a phenylene group and a naphthylene group, and examples of the substituent that they may have include the above-described halogen atom, alkyl group, and aryl group.
[0042]
Although the specific example of diol used for this invention is shown, it is not limited to these.
[0043]
[Chemical formula 14 ]
[0044]
[Chemical 15 ]
[0045]
Preferred examples include structural unit examples 2-1, 2-2, 2-3, 2-5, 2-6, structural unit examples 3-1, 3-2 and structural unit examples 4-3. These mixtures are mentioned.
[0046]
The diol component in the polyester resin used in the present invention may be a polymer composed of the same one represented by the formula (2) or a polymer composed of two or more different structural units represented by the formula (2). . The same applies to the diols represented by formula (3) and formula (4).
[0047]
Further, the diol component may be a polymer composed of both structural units represented by the formulas (2) and (3), for example.
[0048]
Further, the diol component may be a mixture of the diol represented by the formula (2), the formula (3), and the formula (4) and another diol.
[0049]
Other diols include lower alkylene glycols, and specific examples include, but are not limited to, ethylene glycol and neopentyl glycol. Furthermore, you may contain 1 component or 2 components or more among these.
[0050]
More preferably, by adding 5 mol% or more of a low boiling point diol such as ethylene glycol to the total diol component, there are advantages such that the polymerization proceeds rapidly and the polymerization time can be shortened.
[0051]
By using these diol components, the solubility is improved, and if it is a surface layer, a surface layer having excellent wear resistance can be formed.
[0052]
If necessary, the polyester resin according to the present invention and a thermoplastic resin generally used in the field of electrophotographic photoreceptors may be mixed, or each may be used after being copolymerized with a lower molecular weight.
[0053]
The thermoplastic resin used in the present invention is a material generally used in the field of electrophotographic photoreceptors, and among them, a material having high mechanical strength is preferable. For example, polycarbonate, polyarylate, polyamide, polysulfone , Phenoxy, epoxy resin, and the like, but are not limited thereto.
[0054]
The electrophotographic photosensitive member of the present invention can be used in an electrophotographic process using DC contact charging means (hereinafter referred to as AC / DC contact charging means) or DC contact charging means superimposed with AC, and has excellent mechanical strength, It is possible to provide an electrophotographic photoreceptor exhibiting high strength, excellent electrical sensitivity, little photo memory, and excellent electrophotographic characteristics such as charging characteristics, sensitivity, residual potential and repetition characteristics.
[0055]
The effect of the alicyclic dicarboxylic acid used in the present invention improves the electrophotographic characteristics, but this is due to the higher LUMO level of the molecular orbitals (= lower acceptor properties) than the aromatic dicarboxylic acid. If a resin with a strong acceptor property and a charge transport material are mixed, a complex is formed and it becomes easy to color, but the combination of the resin used in the present invention and the charge transport material suppresses the coloration, as well as the electrical sensitivity. Photo memory is also expected to improve.
[0056]
The glass transition point of the polyester resin used in the present invention is about 120 ° C. lower than that of the polycarbonate resin or polyarylate resin. Therefore, it is considered that there is an advantage that there is almost no brittleness, and at the same time, the polymer chain is likely to move, that is, plastic deformation is likely to occur. Therefore, it is estimated that it can absorb by deforming external force, such as pressure of a roller or a blade.
[0057]
Specifically, since the polyester resin used in the present invention alternately includes an aromatic ring unit or Si-Si unit having a large interaction ability and an alicyclic dicarboxylic acid unit having a relatively small interaction ability, it is described above. It is presumed that the interaction between adjacent polymer chains is smaller than that of the aromatic resin, and a space that is easy to move is formed, and as a result, plastic deformation is likely to occur.
[0058]
Hereinafter, the structure of the electrophotographic photosensitive member used in the present invention will be described.
[0059]
In the electrophotographic photoreceptor of the present invention, the photosensitive layer may be a single layer type in which the charge transport material and the charge generation material are contained in the same layer, or may be a stacked type in which the charge transport layer and the charge generation layer are separated, From the viewpoint of electrophotographic characteristics, a laminated type is preferable.
[0060]
The support used in the present invention may be any one as long as it has conductivity, for example, a metal such as aluminum, copper, chromium, nickel, zinc and stainless steel formed into a drum or a sheet, aluminum And metal foils such as copper and copper laminated on plastic films, and aluminum, indium oxide, tin oxide and the like deposited on plastic films.
[0061]
When the image input such as LBP is laser light, a conductive layer may be provided for the purpose of preventing interference fringes due to scattering or covering a scratch on the support. This can be formed by dispersing conductive powder such as carbon black and metal particles in a binder resin. The thickness of the conductive layer is preferably 5 to 40 μm, and more preferably 10 to 30 μm. An intermediate layer having an adhesive function is provided thereon. Examples of the material for the intermediate layer include polyamide, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, casein, polyurethane, and polyether urethane. These are dissolved in an appropriate solvent and applied. The thickness of the intermediate layer is preferably 0.05 to 5 μm, and more preferably 0.3 to 1 μm.
[0062]
A charge generation layer is formed on the intermediate layer. Examples of the charge generating material used in the present invention include selenium-tellurium, pyrylium, thiapyrylium dyes, phthalocyanine, anthanthrone, dibenzpyrenequinone, trisazo, cyanine, disazo, monoazo, indigo, quinacridone, and asymmetric quinocyanine pigments. It is done. In the case of the functional separation type, the charge generation layer comprises the charge generation material 0.3 to 4 times the weight of binder resin and solvent, homogenizer, ultrasonic dispersion, ball mill, vibration ball mill, sand mill, attritor, roll mill, and liquid collision It is well dispersed by a method such as a type high-speed disperser, coated with a dispersion, and dried. The film thickness of the charge generation layer is preferably 5 μm or less, more preferably 0.1 to 2 μm.
[0063]
The charge transport layer is formed by applying a coating material in which the binder resin group and the charge transport material used in the present invention are dissolved in a solvent and then drying. The charge transport material is combined with 0.5 to 2 times the weight of the binder resin, applied, and dried to form a charge transport layer. The film thickness of the charge transport layer is preferably 5 to 40 μm, and more preferably 15 to 30 μm.
[0064]
FIG. 1 shows a schematic configuration of an electrophotographic apparatus having a process cartridge having the electrophotographic photosensitive member of the present invention.
[0065]
In the figure, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is rotated about a shaft 2 in the direction of an arrow at a predetermined peripheral speed. In the rotation process, the photosensitive member 1 is uniformly charged with a predetermined positive or negative potential on its peripheral surface by the primary charging unit 3, and then from an image exposure unit (not shown) such as slit exposure or laser beam scanning exposure. Image exposure 4 is received. In this way, electrostatic latent images are sequentially formed on the peripheral surface of the photoreceptor 1.
[0066]
The formed electrostatic latent image is then developed with toner by the developing unit 5, and the developed toner image is synchronized with the rotation of the photoconductor 1 between the photoconductor 1 and the transfer unit 6 from a paper supply unit (not shown). The transfer means 6 sequentially transfers the transfer material 7 taken and fed.
[0067]
The transfer material 7 that has received the image transfer is separated from the surface of the photosensitive member, introduced into the image fixing means 8, and subjected to image fixing, thereby being printed out as a copy (copy).
[0068]
After the image transfer, the surface of the photoreceptor 1 is cleaned by removing the transfer residual toner by the cleaning unit 9 and further subjected to the charge removal process by the pre-exposure 10 from the pre-exposure unit (not shown). Used for forming. When the primary charging unit 3 is a contact charging unit using a charging roller or the like, pre-exposure is not always necessary.
[0069]
In the present invention, a plurality of components such as the above-described electrophotographic photosensitive member 1, primary charging unit 3, developing unit 5, and cleaning unit 9 are integrally coupled as a process cartridge. May be configured to be detachable from an electrophotographic apparatus main body such as a copying machine or a laser beam printer. For example, a process in which at least one of the primary charging unit 3, the developing unit 5, and the cleaning unit 9 is integrally supported together with the photosensitive member 1 to form a cartridge and is detachable from the apparatus main body using guide means such as a rail 12 of the apparatus main body. The cartridge 11 can be obtained.
[0070]
In addition, when the electrophotographic apparatus is a copying machine or a printer, the image exposure 4 scans the original by reflecting or transmitting light from the original or by reading a signal with a sensor and scanning the laser beam according to this signal. The light is emitted by driving the LED array and the liquid crystal shutter array.
[0071]
The electrophotographic photosensitive member of the present invention can be used not only in electrophotographic copying machines but also widely in electrophotographic application fields such as laser beam printers, CRT printers, LED printers, liquid crystal printers, and laser plate making.
[0072]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples. In the examples, “parts” represents parts by weight.
[0073]
[Example 1]
Using a 30φ, 357 mm aluminum cylinder as a support, a coating composed of the following materials is applied on the support by a dip coating method and thermally cured at 140 ° C. for 30 minutes, and a conductive layer having a thickness of 15 μm. Formed.
[0074]
Conductive pigment: SnO ₂ coated barium sulfate 10 parts Resistance adjusting pigment: Titanium oxide 2 parts Binder resin: Phenol resin 6 parts Leveling material: Silicone oil 0.001 part Solvent: Methanol, methoxypropanol 0.2 / 0.8 20 copies [0075]
Next, a solution obtained by dissolving 3 parts of N-methoxymethylated nylon and 3 parts of copolymer nylon in a mixed solvent of 65 parts of methanol and 30 parts of n-butanol was applied thereto by a dip coating method, and 10 minutes at 100 ° C. It dried and formed the intermediate | middle layer whose film thickness is 0.5 micrometer.
[0076]
Next, 4 parts of oxytitanium phthalocyanine (TiOPc) having strong peaks at 9.0 °, 14.2 °, 23.9 ° and 27.1 ° with a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction , 2 parts of polyvinyl butyral (trade name: ESREC BM2, manufactured by Sekisui Chemical Co., Ltd.) and 60 parts of cyclohexanone were dispersed in a sand mill apparatus using φ1 mm glass beads for 4 hours, and then 100 parts of ethyl acetate was added to form a charge generation layer. A dispersion was prepared. This was applied by a dip coating method and dried at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.2 μm.
[0077]
Next, 8 parts of a triarylamine compound represented by the following formula (5),
[0078]
[Of 16]
[0079]
1 part of a stilbene compound represented by the following formula (6)
[Chemical formula 17 ]
[0081]
And 11 parts of a polyester resin (Mw≈45,000) represented by the following formula (7) obtained by directly synthesizing the compound described in Example 1 of Table 1 by a direct melt polymerization method in the presence of a catalyst.
[Chemical Formula 18 ]
[0083]
Was dissolved in a mixed solvent of 40 parts of monochlorobenzene and 60 parts of dichloromethane. This polymer used what was synthesize | combined in the following procedures.
[0084]
344 g (2.0 mol) of 1,4-cyclohexanedicarboxylic acid represented by constitutional unit example 1-1, 365 g (1.6 mol) of a compound represented by constitutional unit example 2-1 as a diol component, 13 g (0.4 mol) of ethylene glycol ) And 0.7 g of di-n-butyltin oxide as a catalyst were charged into a 3 liter flask and subjected to esterification at a pressure of 10 to 30 mmHg and a temperature of 247 ° C. for 15 hours.
[0085]
This paint was applied onto the charge generation layer by a dip coating method and dried at 130 ° C. for 1 hour to form a charge transport layer having a thickness of 25 μm.
[0086]
Next, evaluation will be described.
[0087]
The produced electrophotographic photosensitive member is a “GP-40” (manufactured by Canon Inc.) having a process speed of 210 mm / sec in a copying machine having roller contact charging means (AC / DC roller contact charging means) superimposed with AC voltage. The dark potential Vd, sensitivity EΔ500, and residual potential Vr were measured in a normal temperature and humidity environment (N / N) at 23 ° C. and 50% RH. The GP-40 was modified to measure the electrophotographic characteristics of the photoreceptor.
[0088]
The dark portion potential Vd indicates that the charging capability is better as the absolute value is larger, and the sensitivity EΔ500 is the amount of light necessary to attenuate the potential from −700 V to −200 V, and the smaller the value is, the better the sensitivity is.
[0089]
Further, a 50,000 sheet passing durability test was performed under normal temperature and normal humidity, and the dark portion potential Vd, sensitivity EΔ500, and residual potential Vr at the initial stage and after 30,000 sheets were measured. The amount of wear after 30,000 sheets was also measured. An eddy current film thickness measuring machine (Permascope type E111) manufactured by Fischer was used for the measurement of the wear amount.
[0090]
The image was A4, and a grid pattern with a printing rate of 4% was used. The sequence was an intermittent mode that stopped once for each printed sheet. If the toner runs out, it was replenished.
[0091]
Furthermore, 3,000 Lux, a part of the electrophotographic photosensitive member, was irradiated with light from a white fluorescent lamp for 20 minutes and left for 4 minutes. Then, the bright part potential was measured to determine how much the bright part potential had dropped before the light was applied. Memory value was used. The amount of change from 0 to 50V is indicated by ◯, the amount of change from 51 to 100V is indicated by Δ, and the change amount by 101V or more is indicated by ×. The results are shown in Table 2.
[0092]
[Examples 2 to 8]
An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the polyester resin described in Table 1 was used as the binder for the charge transport layer. The results are shown in Table 2.
[0093]
[Table 1]
[0094]
[Example 9]
The binder in the charge transport layer in Example 1 is the binder in the charge transport layer in Example 7 (the following formula (8)) and the polyarylate resin (Mw≈50,000) (U-polymer, manufactured by Unitika Ltd.) Instead of the above, an electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the composition ratio was 8 parts / 3 parts (the following formula (8) / polyarylate resin). The results are shown in Table 2.
[0095]
[Chemical formula 19 ]
[0096]
[Comparative Example 1]
In the same manner as in Example 1, except that a polyester resin represented by the following formula (10) was used in which the constituent unit of the binder in the charge transport layer in Example 1 was changed from 1,4-cyclohexanedicarboxylic acid to terephthalic acid. Photoconductors were prepared and evaluated. The results are shown in Table 2.
[0097]
[Chemical formula 20 ]
[0098]
[Comparative Example 2]
An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that a polyester resin in which the structural unit of the binder in the charge transport layer in Example 7 was changed from 1,4-cyclohexanedicarboxylic acid to terephthalic acid was used. The results are shown in Table 2.
[0099]
[Comparative Example 3]
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that the binder in the charge transport layer in Example 1 was replaced with a polyarylate resin (Mw≈50,000) (U polymer, manufactured by Unitika Ltd.). did. The results are shown in Table 2.
[0100]
[Comparative Example 4]
An electrophotographic photosensitive member was prepared in the same manner as in Example 1 except that the binder in the charge transport layer in Example 1 was replaced with polycarbonate resin (Mw≈52,000) (Iupilon Z-200, manufactured by Mitsubishi Engineering Plastics). Created and evaluated. The results are shown in Table 2.
[0101]
[Table 2]
[0102]
From the above results, it was shown that an electrophotographic photosensitive member using a specific polyester resin has good wear resistance and electrical sensitivity, and excellent repeatability.
[0103]
【The invention's effect】
The electrophotographic photoreceptor according to the present invention can be used in an electrophotographic process using a contact charging means, exhibits excellent mechanical strength and electrical strength, has good electrical sensitivity, has little photo memory, and has charging characteristics. In addition, it is possible to provide an electrophotographic photoreceptor excellent in electrophotographic characteristics such as sensitivity, residual potential, and repetitive characteristics, and a process cartridge and an electrophotographic apparatus having the electrophotographic photoreceptor.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus having a process cartridge having an electrophotographic photosensitive member of the present invention.

Claims (5)

In an electrophotographic photosensitive member having a photosensitive layer on a support, the photosensitive layer has a dicarboxylic acid component represented by the following formula (1-1) or (1-2) or an ester-forming derivative thereof, and the following formula (2): An electrophotographic photoreceptor comprising a polyester resin comprising the diol component represented by any one of (4) to (4) .
(In the formula (2), Z represents a single bond, —O—, —S—, an alkylene group or a cycloalkylene group which may be substituted, and R _{1 to} R ₈ are each a hydrogen atom, a halogen atom, or a substituted group. And each represents an alkyl group or an aryl group, and R ₉ and R _{10 each} represent a single bond or an optionally substituted alkylene group or oxyalkylene group.)
(In the formula (3), R _{11 to} R ₁₄ represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms which may be substituted, and R ₁₅ and R _{16 each} represent an alkylene having 1 to 5 carbon atoms which may be substituted. Group.)
(In the formula (4), R _{17 to} R _{20 each} represent a hydrogen atom, a halogen atom, or a silyl group, an alkyl group or an aryl group, each of which may be substituted, l represents an integer of 2 or more, and m represents 0 or more. Indicates an integer.) The diol component, the equation (2) diol and the formula (3) The electrophotographic photosensitive member according to claim 1 diols and a mixture of a lower alkylene glycol. The electrophotographic photosensitive member according to claim 1 or 2 containing a polyester resin comprising the diol component and the dicarboxylic acid component, and another thermoplastic resin. Detachable and an electrophotographic photosensitive member according to any one of claims 1 to 3, a charging means, an exposure means, at least one means selected from the group consisting of the developing means and cleaning means integrally supported, in an electrophotographic apparatus main body A process cartridge that is free to use. The electrophotographic photosensitive member according to any one of claims 1 to 3, a charging means, an exposure means, the electrophotographic apparatus, characterized in that it comprises a developing means and cleaning means.