JP2002107971A - Electrophotographic photoreceptor process cartridge and electrophotographic device both having the electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor which shows more stable characteristics in repeated use in an electrophotographic process requiring a high processing speed, high picture quality high durability. SOLUTION: In the electrophotographic photoreceptor having a photosensitive layer on conductive supporting body, the resin to form the photosensitive layer is a polyallylate resin shown by the compound below which is synthesized by the interface polymerization method from aromatic diols and aromatic dicarboxylic halides with using a phase transfer catalyst. The inherent viscosity of the resin ranges from 0.7 to 2.0 and the residual catalyst amount in the resin is <=100 ppm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic photosensitive member, a process cartridge having the electrophotographic photosensitive member, and an electrophotographic apparatus.

[0002]

2. Description of the Related Art An electrophotographic photosensitive member is one of typical image holding members. Electrophotography is instantaneous,
In recent years, since high-quality images can be obtained, they have been widely used and applied not only in the field of copying machines but also in the field of various printers. The core photoreceptor includes inorganic materials typified by selenium, cadmium sulfide, and zinc oxide.In recent years, however, organic materials have been considered to be non-pollution, high productivity, easy material design, and future potential. Development of system materials has been actively carried out.

[0003] These electrophotographic photoreceptors naturally have electrical, mechanical,
Further, various characteristics such as optical characteristics are required. Especially for photoreceptors that are used repeatedly, charging, exposure, development,
Since electrical and mechanical forces such as transfer and cleaning are repeatedly applied directly or indirectly, durability against them is required. In particular, in an apparatus using an electrophotographic process from now to the future, since higher speed, higher image quality, and higher stability are further required, durability that can repeatedly use high characteristics is required.

In an organic photoreceptor, an organic photoconductive substance is usually used by dissolving or dispersing it in a binder resin to form a coating film. The coating film is formed by dissolving or dispersing the organic photoconductive substance and the binder resin, and then coating and drying.

Examples of the binder resin include vinyl polymers such as polymethyl methacrylate, polystyrene and polyvinyl chloride, and copolymers thereof, polycarbonate, polyester, polyarylate, polysulfone, phenoxy resin, epoxy resin and silicone resin. Is used.

[0006] Each material has a characteristic. In particular, polycarbonate is widely used as a photoreceptor because of its moderate characteristics and good productivity. However, the durability due to abrasion in the above electrophotographic process is sufficient. I can't say that.

On the other hand, polyarylate is a material having excellent strength, but it is not always the case that both strength and characteristics are compatible. That is, polyarylate is well known as an engineered plastic, but its use is as a molded article for electric parts, automobile parts, and the like, and its use as a material for an electrophotographic photosensitive member is limited. The reason is that in the composition in the resin, it is necessary to consider the influence of impurities and residues in the resin for the electrophotographic photosensitive member as compared with the molded article, and thereby, for example, the sensitivity, the residual potential, etc. The deterioration of the characteristic becomes large.

[0008] Further, the resin for molding articles is heated and melted so as to have an appropriate fluidity, and is pressed by a mold or the like. However, since fluidity at the time of melting is important, high molecular weight or high viscosity resin is required. Since the resin causes a reduction in workability, the resin having a relatively high viscosity shown in the present invention has been limited. However, since a resin for an electrophotographic photoreceptor is required to have strength such as abrasion resistance, a specific bisphenol structure having good strength and improvement in strength by increasing the molecular weight are more demanded.

For this purpose, polymerization conditions for achieving a high molecular weight are required, and a suitable interfacial polymerization and phase transfer catalyst are required. However, if the catalyst remains in the produced resin, the characteristics of the photoreceptor deteriorate as described above.

[0010] The polymerization of the polymer has the advantage of increasing the entanglement of the polymer chains and increasing the strength, but also has the disadvantage of lowering the purification efficiency such as reprecipitation. Until now, polyarylate which achieves high molecular weight and high purity suitable for electrophotographic photoreceptors has not been obtained.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide a binder resin for obtaining an electrophotographic photosensitive member having stable characteristics in repeated use, and more particularly, to a binder resin for forming a photosensitive layer, and more particularly to a specific bisphenol compound. It is an object of the present invention to provide an electrophotographic photoreceptor comprising a polyarylate resin having a high molecular weight and a low content of residual catalyst in the resin.

[0012]

According to the present invention, there is provided an electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein a resin for forming the photosensitive layer comprises at least an aromatic diol and an aromatic dicarboxylic acid halide. A polyarylate resin represented by the following general formula (1) synthesized by an interfacial polymerization method using a transfer catalyst, wherein the resin has an inherent viscosity of 0.7 to 2.0, and has a residual viscosity in the resin. The amount of catalyst is 1
It is composed of an electrophotographic photosensitive member characterized by being at most 00 ppm. General formula (1)

Embedded image (Wherein, R _{1 to} R ₄ represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an aryl group, an alkoxy group having 1 to 5 carbon atoms or a halogen atom, X represents a single bond, —CR ₅ —R ₆ R ₅ and R ₆ represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, or an alkylidene group formed by bonding R ₅ and R _6. )

According to the present invention, the electrophotographic photoreceptor of the present invention and at least one means selected from the group consisting of a charging means, a developing means and a cleaning means are integrally supported, and are detachably attached to an electrophotographic apparatus main body. The process cartridge comprises:

Further, the present invention comprises an electrophotographic apparatus having the electrophotographic photoreceptor of the present invention, charging means, exposure means, developing means and transfer means.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION As a resin for an electrophotographic photoreceptor, a polyarylate resin is one of materials suitable for strength.
In order to provide more stable properties in repeated use, better abrasion resistance is required. In order to achieve the mechanical strength and the like of the resin for that purpose, it is necessary to increase the molecular weight, and for that purpose, an interfacial polymerization method is suitable.

[0016] Polymerization for obtaining polyarylate includes methods such as solution polymerization and melt polymerization. However, the resins obtained by these methods have not reached a high molecular weight as resins used in electrophotographic photoreceptors. In addition, the solubility in a solvent may be reduced, and further, the electric characteristics and the like when a photoreceptor is formed may be reduced due to the structure of the terminal of the polymer chain.

In the interfacial polymerization method, an alkali aqueous solution (aqueous phase) in which bisphenol is dissolved and a hydrophobic organic solvent solution (organic phase) in which dicarboxylic acid halide is dissolved are brought into contact with each other to perform polycondensation at the interface. Although it is necessary to optimize the molar amount of the resin, it is relatively easy to increase the molecular weight and control the reaction system, and thus it is easy to obtain a resin suitable for the electrophotographic photosensitive member of the present invention.

In the polymerization, it is preferable to use a phase transfer catalyst in order to increase the reactivity. Since the polyarylate resin used in the present invention is required to have a high molecular weight, the polymerization using the catalyst causes Satisfies the achievement of high molecular weight, electrophotographic photoreceptor characteristics, etc.

The phase transfer catalyst used to achieve a high molecular weight is soluble in an aqueous phase and an organic phase (hydrophilicity / lipophilicity).
Is affected by the reaction efficiency, and by increasing the lipophilicity, the catalyst easily moves to the organic phase in the form of an ion pair, whereby the reaction efficiency is increased and the molecular weight can be increased. In order to change the lipophilicity, it is possible to change the number of carbon atoms of the substituent of the catalyst.

Since the polyarylate produced by the interfacial polymerization dissolves in the organic phase, it can be obtained by reprecipitation by dropping the organic phase into a poor solvent such as alcohol. However, when a phase transfer catalyst having high lipophilicity is used in order to increase the efficiency, the partition ratio of the catalyst to the organic phase increases, and the catalyst is mixed into the produced polymer existing in the organic phase. The mixed catalyst can be theoretically separated from the polymer by selecting a solvent for reprecipitating the polymer, but a part thereof actually remains in the polymer. However, many of the polyarylate resins have been used as resins for molding products in the past, their use in electrophotographic photoreceptors was small, and their electrophotographic processes were slow. Therefore, the effect of the residual catalyst was not realized.

However, the present inventors have found that the residual catalyst causes deterioration of the electric characteristics of the electrophotographic photosensitive member. That is, in an electrophotographic process that requires high speed, high image quality, and high durability, the binder resin of the electrophotographic photoreceptor used therein not only increases the strength by increasing the molecular weight, but also extremely reduces the residual catalyst. I found it important. Aiming for high molecular weight, and
It has been found that it is important to reduce the amount of residual catalyst in the polymerization reaction.

The photosensitive layer is formed from an organic photoconductive material such as a charge generating material and a charge transport material and a binder resin. To obtain good electric characteristics of the electrophotographic photosensitive member, the photosensitive layer must be formed in the photosensitive layer. Using a resin with a small amount of residual catalyst,
Alternatively, the content of a photosensitive material such as a charge generating material or a charge transporting material may be increased to keep the amount of the phase transfer catalyst in the photosensitive layer relatively low (preferably 60 ppm or less). At that time, by increasing the amount of the organic photoconductive material, the ratio of the residual catalyst in the layer is kept low.
Since the film strength of the layer decreases, it is necessary to select an appropriate amount.

In the structures represented by the general formulas (1) and (4), since the phenyl group of the bisphenol structure has an appropriate substituent, the structure of the polymer chains and the arrangement between the polymer chains are appropriately controlled. Not only does the polymer exhibit strength, but the polymer has a particularly good solubility in the solvent, which facilitates the movement of the reaction site during polymerization, thus improving the efficiency of the polymer. Impurities (unreacted monomers, catalysts, etc.) due to the good spread of polymer chains when dissolved in the solvent used for reprecipitation purification
It is presumed that the separation from is easy. From this, it has been found that a resin having a high molecular weight and a low residual catalyst can be achieved relatively easily.

The reaction catalyst for obtaining the resin in the present invention is preferably a quaternary ammonium salt represented by the following general formula (2) or a phosphonium salt represented by the following general formula (3). General formula (2)

Embedded image (Wherein, R _{11 to} R ₁₃ represent an alkyl group having 1 to 5 carbon atoms, R ₁₄ represents an alkyl group or an aromatic substituted alkyl group, and X represents a halogen atom.) General formula (3)

Embedded image (In the formula, R _{15 to} R ₁₇ represent an alkyl group having 1 to 5 carbon atoms, R ₁₈ represents an alkyl group or an aromatic substituted alkyl group, and X represents a halogen atom.)

The means for reducing the amount of the catalyst remaining in the polymer is not limited. However, the selection of the catalyst species in the polymerization reaction, the use amount as small as possible, and the conditions for reprecipitation purification (solvent, Concentration, frequency, etc.). However, if the polymerization efficiency is reduced by reducing the type or amount of the catalyst used, a sufficient molecular weight (solution viscosity) cannot be obtained, so the selection of conditions is important.

In the present invention, the inherent viscosity ηinh
Is shown in the following equation. ηinh = 1nηr / C Using 1,1,2,2-tetrachloroethylene as a solvent, a concentration C of 1 g / dl was produced. The relative viscosity ηr was measured at a temperature of 25 ° C. using an Ubbelohde viscometer, and 1n was obtained as a natural logarithm.

The residual catalyst in the polymer was quantified by gas chromatography under the following conditions. Sample 0.5
g was dissolved in 10 ml of chloroform and reprecipitated with methanol. At this time, diphenyl 50 was added to the precipitation solution as a standard.
μg was added, and the total amount was adjusted to 50 ml with methanol.

This sample was subjected to gas chromatography [column: methyl silicon capillary (5 m × 0.53 m)
m), column temperature: 250 ° C., carrier gas: He, detector: FID], and the amount of catalyst was determined from the peak area.

As described above, a specific aromatic diol and an aromatic dicarboxylic acid halide are synthesized by an interfacial polymerization method using a phase transfer catalyst and have an inherent viscosity of 0.7 to 2.0.
By using a polyarylate resin having an amount of residual catalyst in the resin of 100 ppm or less for the electrophotographic photoreceptor, it is more repetitive in an electrophotographic process requiring high speed, high image quality, and high durability. It can provide stable characteristics.

The polyarylate resin represented by the general formula (1) can also be a copolymer with bisphenol having another structure in order to add other properties such as strength and solubility. Further, it can be blended with a polyarylate or polycarbonate of another structure to improve productivity.

The molecular weight of the polymer is preferably from 0.7 to 2.0, particularly preferably from 0.8 to 1.5 in the above-mentioned inherent viscosity. A low inherent viscosity indicates that a high molecular weight has not been obtained, and the mechanical strength of the polymer, that is, abrasion resistance, cannot be sufficiently obtained. Although the high molecular weight is achieved when the number of times of the inheritance is high, the solubility of the polymer and the low handling due to high viscosity at the time of forming a solution or coating the photoreceptor occur. Further, when removing and purifying the catalyst, the catalyst is likely to remain between the polymer chains, making it difficult to remove the catalyst. Although there is no strict relational expression between the inherent viscosity and the weight average molecular weight, when the inherent viscosity = 0.7 to 2.0, the weight average molecular weight Mw ≒ 7
It can be estimated that it is 10,000 to 300,000.

The aromatic diol and aromatic dicarboxylic acid halide shown in the present invention are represented by the following general formulas (5) and (6). General formula (5)

Embedded image (Wherein, R _{1 to} R ₄ and X have the same meanings as in general formula (1)).

Embedded image (In the formula, R ₂₀ and R ₂₁ represent an alkyl group or an aryl group, and X represents a halogen atom.)

The aromatic dicarboxylic acid halide represented by the general formula (6) includes terephthalic acid halide, isophthalic acid halide, orthophthalic acid halide, diphenic acid halide, naphthalene carboxylic acid halide and the like. Iodine.

The solubility of the resulting polyarylate,
These dicarboxylic acid halides can be appropriately mixed and used in order to change physical properties and the like. In particular, when increasing the solubility, terephthalic acid / isophthalic acid is added to 30/7.
It is preferable to use 0 to 70/30.

Tables 1 to 4 show specific examples of the compound represented by the general formula (1) comprising the general formulas (5) and (6), but are not limited thereto.

[0036]

[Table 1]

[Table 2]

[Table 3]

[Table 4]

Further, the present invention is not limited to the above-mentioned specific example.
It can also be used as a copolymer obtained by copolymerizing two or more aromatic diols. The compound represented by the structural unit (2) is shown as a copolymer of the compound example (1-2) and the compound example (1-17), and the copolymerization ratio is the same as that of the compound example (1).
In the case of -2) / (1-17) = 95/5 to 5/95, the effect of each characteristic can be exhibited. 80/20
To 20/80 is preferred.

The compound of the present invention can be used as a mixture with other polymers. Examples of the compound include polyester, polyarylate, polysulfone, phenoxy resin, epoxy resin, and silicone resin. It is also possible to improve the abrasion resistance, the productivity during the production of the photoconductor, the stability of the solution, and the like.

The polycarbonate may be dissolved in the solvent used, and is not particularly limited.
Type, C type, AP type, AF type, DP type, siloxane modified type and the like. The mixing ratio can be set as follows: polymer / polycarbonate in the present invention = 5/95 to 95/5, and 20/80 to 80/2 in order to exhibit the effect efficiently.
0 is preferred.

Next, specific examples of the phase transfer catalysts of the general formulas (2) and (3) will be shown. ^{_{(CH 3) 4 N + Cl}} -, (CH 3) 4 N + Br -, (C 2
_{^{H 5) 4 N + Cl -}} , (C 4 H 9) 4 N + Cl -, (C
^{_{4 H 9) 4 N + Br}} -, (CH 3) 3 C 6 H 5 CH 2 N + Cl
_{^{-, (C 2 H 5)}} 3 C 6 H 5 CH 2 N + Cl -, (C 3 H 7) 3
(C ₆ H ₅ CH ₂ ) N ⁺ Cl ⁻ , (C ₄ H ₉ ) ₃ (C ₆ H ₅ CH
_{^{2) N + Cl -, (}} CH 3) 3 (C 10 H 21) N + Cl -,
(CH ₃ ) ₄ P ⁺ Cl ⁻ , (C ₃ H ₇ ) ₄ P ⁺ Cl ⁻ , (C ₄
H ₉ ) ₄ P ⁺ Br ⁻ , (C ₄ H ₉ ) ₄ P ⁺ Cl ⁻ , (C
_{6 H 5) 3 (CH 3} ) P + Cl -

Further, the present invention is not limited to the above-mentioned specific examples.
Mixtures of more than one species can be used. The amount used varies depending on the reactivity of the monomer used, the efficiency of the catalyst, and the like, but must be selected within the range of 0.1 to 5 mol% based on the monomer, and particularly when a high molecular weight is intended, a large amount of catalyst is required. I do. However, the use of a large amount of catalyst causes an increase in the amount of residual catalyst in the produced polymer. Although any of the above catalysts can achieve a high molecular weight and a low residual catalyst amount in the present invention, the following (C ₄ H ₉ ) ₄ N ⁺ Cl ⁻ , (C ₃ H ₇ ) ₃ (C ₆ H ₅ CH ₂₎ )
N ⁺ Cl ⁻ , (C ₄ H ₉ ) ₃ (C ₆ H ₅ CH ₂ ) N ⁺ Cl ⁻ ,
(C ₃ H ₇ ) ₄ P ⁺ Cl ⁻ and (C ₄ H ₉ ) ₄ P ⁺ Cl ⁻ are particularly preferred.

The means for achieving a low residual catalyst is not particularly limited, but a method by reprecipitation is effective. However, in the present invention, in order to achieve a low residual catalyst amount in the polymer, it is necessary to first achieve a high molecular weight with a small catalyst amount, and further, selection of a reprecipitation solvent and an increase in the number of times of reprecipitation are required. Required.

As a solvent for reprecipitation, any solvent can be used as long as it can dissolve the polymer, but toluene and tetrahydrofuran are particularly preferable. As the poor catalyst for reprecipitating the polymer, alcohols such as methanol and ethanol are preferable in addition to water for dissolving the salt. Also, polymers,
From the solubility of the catalyst, it is more effective to use a mixture of the above and other solvents. Further, it is necessary to repeat the reprecipitation several times or more in order to lower the residual catalyst amount. In order to further enhance the purification efficiency, it is also preferable to subject the purification system to heating, ultrasonic irradiation, or the like.

Synthesis Example (Synthesis of Compound Example (1-2)) In the general formula (5), bisphenol C type monomer in which R ₁ and R ₃ are methyl groups and R ₂ and R ₄ are hydrogen atoms.
After dissolving 6 mol, 0.015 mol of pt-butylphenol as a molecular weight modifier and 65 g of sodium hydroxide in 2 liters of ion-exchanged water, tributylbenzylammonium chloride (TBBAC) as a phase transfer catalyst is used.
0.004 mol was added and dissolved (aqueous phase). Separately, 1: 1 of terephthalic acid chloride and isophthalic acid chloride
0.6 mol of the mixture was dissolved in 1 liter of dichloromethane (organic phase). The reaction vessel was maintained at 20 ° C., and the organic phase was added to the aqueous phase with vigorous stirring, and interfacial polymerization was performed for 4 hours. Although the generated polymer exists in the organic phase, the organic phase was sufficiently washed with ion-exchanged water in order to suppress the catalyst from being mixed into the polymer. Further, the organic phase was dropped into methanol to reprecipitate and isolate the polymer.

Polymer Purification As a method for purifying the polymer to further reduce the mixing of the residual catalyst, the polymer obtained above was converted into a 5% toluene solution and washed with ion-exchanged water at 40 ° C. In the cleaning, ultrasonic irradiation was performed to promote the aqueous system of the catalyst. Thereafter, the polymer was dropped into methanol for reprecipitation to isolate the polymer. After repeating this scanning twice, drying was performed under reduced pressure. ηinh = 1.01 and the amount of residual catalyst was 80 ppm.

In the electrophotographic photoreceptor of the present invention, the photosensitive layer contains a charge transporting material and a charge generating material in the same layer, that is, a single layer type, and a charge transporting layer containing a charge transporting material and a charge generating material. The present invention is applied to any of the stacked type having a charge generation layer.

The binder resin and the solvent for forming the photosensitive layer are not limited in the photosensitive layer to be used, and the binder resin is formed by dissolving and dispersing a material for forming the photosensitive layer (for example, a charge generation material or a charge transport material). In the case of a layer to be used, for example, in a laminated photoreceptor, it can be used as a charge generation layer, a charge transport layer, and a protective layer, and can be used in a single layer type.

As the charge generating material in the electrophotographic photoreceptor of the present invention, generally known materials can be used, for example, selenium-tellurium, pyrylium, metal phthalocyanine, metal-free phthalocyanine, anthranthrone pigment, dibenzpyrene Examples include quinone pigments, trisazo pigments, disazo pigments, monoazo pigments, cyanine pigments, indigo pigments, and quinacridone pigments. These pigments are well dispersed with a binder resin and a solvent in a weight of 0.3 to 4 times by using a homogenizer, an ultrasonic disperser, a ball mill, a vibration mill, a sand mill, an attritor, a roll mill, a liquid collision type high-speed disperser or the like. The resulting dispersion is used. In the case of a laminated photoreceptor, this liquid is applied and dried to form a charge generation layer. The film thickness is 5 μm or less, especially 0.1 to
It is preferably 2 μm.

As the charge transporting material, generally known materials can be used, for example, triarylamine compounds, hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, triallylamine compounds, thiazole compounds. And the like. These compounds are dissolved in a solvent together with a binder resin to form a solution. In the case of a laminated photoreceptor, this liquid is applied and dried to form a charge transport layer. The film thickness is 5 to 40 μm,
Particularly, the thickness is preferably 15 to 30 μm.

When the photosensitive layer is of a single layer type, it can be formed by applying a solution in which the above-mentioned charge generating material or charge transporting material is dispersed or dissolved in the above-mentioned binder resin, and then drying. The thickness is preferably from 5 to 40 μm, particularly preferably from 15 to 30 μm.

The protective layer can be formed by applying a solution obtained by dissolving the above-mentioned binder resin in a solvent and drying the solution. If necessary, a material for the electrophotographic photoreceptor, a conductive material for controlling the resistance value, a lubricating material for providing lubricity, and the like can be added.

In an electrophotographic photoreceptor having no protective layer, an antioxidant, a lubricant, etc. can be added to the surface layer as necessary.

In the electrophotographic photoreceptor of the present invention, an intermediate layer having an adhesive function and a charge barrier function can be provided between the support and the photosensitive layer or between the conductive layer and the photosensitive layer, if necessary. As the material of the intermediate layer, polyamide, polyvinyl alcohol, polyethylene oxide,
Ethyl cellulose, casein, polyurethane, polyether urethane and the like can be mentioned. These are dissolved in a solvent, applied, and dried. The thickness of the intermediate layer is 0.05 to 5μ.
m, particularly preferably 0.2 to 1 μm.

The method of applying the coating solution in forming the photosensitive layer is not particularly limited, and any known means such as a dip coating method, a spray coating method, and a bar code coating method can be applied.

Further, the electrophotographic photoreceptor of the present invention exhibits excellent wear resistance by being used in a process (for example, roller charging) in which only a DC voltage is applied from a charging member arranged in contact with the photoreceptor to be charged. And electrical characteristics such as better chargeability and sensitivity are easily obtained.

Next, the process cartridge and the electrophotographic apparatus of the present invention will be described. FIG. 1 shows a schematic configuration of an electrophotographic apparatus having a process cartridge having the electrophotographic photosensitive member of the present invention. In FIG. 1, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is driven to rotate around an axis 2 at a predetermined peripheral speed in the direction of an arrow. 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 means 3, and then exposed light from exposure means (not shown) such as slit exposure or laser beam scanning exposure. Receive 4. Thus, an electrostatic latent image is sequentially formed on the peripheral surface of the photoconductor 1.

The formed electrostatic latent image is then developed by developing means 5
The developed toner image is transferred to a transfer material 7 fed from a paper supply unit (not shown) between the photoconductor 1 and the transfer unit 6 in synchronization with the rotation of the photoconductor 1. Are sequentially transferred by the transfer means 6. The transfer material 7 having undergone the image transfer is separated from the photoreceptor surface, introduced into the image fixing means 8 and subjected to image fixing, thereby being printed out of the apparatus as a copy. The surface of the photoreceptor 1 after the image transfer is cleaned and cleaned by removing the untransferred toner by the cleaning unit 9 and further subjected to a static elimination process by pre-exposure light 10 from a pre-exposure unit (not shown). Used repeatedly for image formation. When the primary charging unit 3 is a contact charging unit using a charging roller or the like, the pre-exposure is not necessarily required.

In the present invention, a plurality of components such as the photosensitive member 1, the primary charging means 3, the developing means 5 and the cleaning means 9 described above are integrally connected as a process cartridge, and this process is performed. The cartridge may be configured to be detachable from a main body of an electrophotographic apparatus 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 photoreceptor 1 to form a cartridge, and which can be attached to and detached from the apparatus main body using guide means such as the rail 12 of the apparatus main body. The cartridge 11 can be used. When the electrophotographic apparatus is a copying machine or a printer, the exposure light 4 uses reflected light or transmitted light from the original, or reads the original with a sensor and converts it into a signal. This is light emitted by scanning a beam, driving an LED array, driving a liquid crystal shutter array, and the like.

The electrophotographic photosensitive member of the present invention can be used not only for an electrophotographic copying machine but also for a laser beam printer,
It can be widely used in electrophotographic applications such as CRT printers, LED printers, liquid crystal printers and laser plate making.

[0060]

The present invention will be described more specifically with reference to the following examples. In the examples, “parts” means “parts by weight”.
Is shown.

Example 1 A paint prepared from the following materials was applied on an aluminum cylinder of 30φ × 357 mm by a dip coating method.
By heat curing at 140 ° C for 30 minutes, the film thickness 15μ
m conductive layers were formed. Conductive pigment: 10 parts of barium sulfate treated with SnO ₂ coating Pigment for resistance control: 2 parts of titanium oxide Binder resin: 6 parts of phenolic resin Leveling agent: 0.001 part of silicone oil Solvent: methanol / methoxypropanol = 2/8 20 parts

Next, a solution prepared 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 on the conductive layer by dip coating. Drying was performed at 10 ° C. for 10 minutes to form an intermediate layer having a thickness of 0.5 μm.

Next, 3 parts of an azo pigment having the following structural formula

Embedded image After 2 parts of polyvinyl butyral (trade name: SREC BM2, manufactured by Sekisui Chemical Co., Ltd.) and 60 parts of cyclohexanone were dispersed for 4 hours by a sand mill using 1 mmφ glass beads, 100 parts of tetrahydrofuran was added to prepare a paint for a charge generation layer. Prepared. This paint was applied on the intermediate layer by a dip coating method, dried at 80 ° C. for 10 minutes,
A μm charge generation layer was formed.

Next, 8 parts of an amine compound having the following structural formula

Embedded image 1 part of amine compound of the following structural formula

Embedded image As a binder resin, 10 parts of the polymer shown in the above Synthesis Example / Compound Example (1-2) obtained by polymer purification was dissolved in 50 parts of chlorobenzene and 50 parts of dichloromethane to prepare a coating for a charge generation layer. This paint was applied by a dip coating method and dried at 120 ° C. for 1 hour to form a charge transporting layer having a thickness of 17 μm to prepare an electrophotographic photoreceptor. Resin ηin
h = 1.01, the amount of residual catalyst in the resin was 80 ppm (the amount of residual catalyst in the charge transport layer was 42 ppm).

Next, the evaluation will be described. The apparatus is a copier NP-6035 manufactured by Canon Inc. (a process of applying only a DC voltage from a charging member placed in contact with an electrophotographic photosensitive member to charge the photosensitive member, and a positive developing method: a process speed of 200 mm / sec). Was used. First, the initial potential was measured. The dark part potential Vd was -700 V, and the light part potential Vl was -200 V. 30,000 sheets were copied in an intermittent mode in which A4 size plain paper was stopped once for each sheet, the abrasion amount of the photoconductor film thickness was measured, and the abrasion amount per 10,000 sheets was obtained.

Example 2 The same procedure as in Example 1 was carried out except that the polymer of the compound example (1-2) shown in the synthesis example as the binder resin for the charge transport layer was subjected to reprecipitation purification with toluene methanol again. An electrophotographic photoreceptor was prepared. . Resin ηinh =
0.94, the amount of residual catalyst in the resin was 18 ppm (the amount of residual catalyst in the charge transport layer was 9 ppm).

Example 3 Example 2 was repeated except that the amount of the phase transfer catalyst used in synthesizing the polymer of the compound example (1-2) shown as a synthesis example as a binder resin for the charge transport layer was 0.002 mol. An electrophotographic photosensitive member was prepared in the same manner as in Example 1. . Resin ηinh = 0.7
9. The amount of residual catalyst in the resin was 30 ppm (the amount of residual catalyst in the charge transport layer was 16 ppm).

Comparative Example 1 The same procedure as in Example 1 was carried out except that the polymer of Compound Example (1-2), which was shown as a synthesis example as the binder resin for the charge transport layer, was a polymer up to the isolation step without the above-mentioned polymer purification. Similarly, an electrophotographic photosensitive member was prepared. . Resin ηinh = 0.9
5. The amount of residual catalyst in the resin was 350 ppm (184 ppm of residual catalyst in the charge transport layer).

Comparative Example 2 The amount of the phase transfer catalyst used in synthesizing the polymer of Compound Example (1-2), which was described as a synthesis example as a binder resin for the charge transport layer, was 0.0005 mol, and the polymer was used without purification. An electrophotographic photoreceptor was prepared in the same manner as in Example 1, except that the polymer was used until the releasing step. Resin ηinh = 0.51, the amount of residual catalyst in the resin was 80 ppm (the amount of residual catalyst in the charge transport layer was 42 ppm).

[0070]

[Table 5]

As shown in Table 5, the electrophotographic photoreceptor of the present invention, as shown in Examples 1 to 3, was expected to provide a high-quality image as a thin charge transporting layer having a thickness of 17 μm. High quality images could be obtained even after repeated use because the photosensitive layer was not damaged and the photosensitive layer was not scratched.

On the other hand, in Comparative Example 1, since the amount of the residual catalyst was large, the bright portion potential increased during repeated use, and a fog image was formed in which toner was deposited on a white background on the image. In Comparative Example 2, although the amount of catalyst remaining in the polymer could be reduced by reducing the amount of catalyst during polymerization, sufficient polymerization did not proceed, the molecular weight did not increase, and the inherent viscosity ηinh became a low value. As a result, the polymer strength could not be obtained, the stability of the potential characteristics was reduced due to the decrease in the charge transport layer in repeated use due to the increase in the amount of wear, and the photosensitive layer was scratched, resulting in an image defect. Was.

Example 4 A conductive layer and an intermediate layer were formed in the same manner as in Example 1. Next, 3 parts of a disazo pigment having the following structural formula was used as a charge generation material.

Embedded image After 2 parts of polyvinyl butyral (trade name: SREC BLS, manufactured by Sekisui Chemical Co., Ltd.) and 80 parts of tetrahydrofuran are dispersed in a sand mill using 1 mmφ glass beads for 4 hours, 80 parts of cyclohexanone is added to prepare a paint for a charge generation layer. Prepared. This paint was applied on the intermediate layer by a dip coating method, and dried to form a charge generation layer having a thickness of 0.1 μm.

Next, in the synthesis process shown in the above synthesis example as a binder resin, the polymerization catalyst was changed to tetrabutylphosphonium chloride (TBPC) and a monomer to obtain a compound example (1-3) nopolymer. / Methanol for reprecipitation purification. Dissolve 10 parts of this polymer in 50 parts of chlorobenzene and 50 parts of dichloromethane, and further add 7 parts of an amine compound having the following structural formula.

Embedded image 1 part of amine compound of the following structural formula

Embedded image Was dissolved. Furthermore, a fluororesin powder (trade name Lubron L
2, a liquid dispersed in 0.5 part of Daikin Industries, Ltd.) and 10 parts of chlorobenzene were added to prepare a coating for the charge transport layer. On the charge generation layer, the paint is applied by a dip coating method,
After drying at 120 ° C. for 1 hour, a charge transport layer having a film thickness of 27 μm was formed, and an electrophotographic photosensitive member was prepared. Resin ηinh =
1.35, the amount of residual catalyst in the resin was 50 ppm (the amount of residual catalyst in the charge transport layer was 27 ppm).

As a device to be evaluated, a copying machine GP-40 manufactured by Canon Inc. (a process of applying a DC and AC voltage from a butt member in contact with an electrophotographic photosensitive member to charge the photosensitive member: reversal development) : Process speed 210mm /
sec) in the same manner as in Example 1.

Example 5 In the procedure of the above-mentioned synthesis example as a binder resin, the polymerization catalyst was changed to tetramethylphosphonium bromide (TMPB) and a monomer to change the compound example (1-
The polymer of 4) was obtained. Example 4 was repeated except that the polymer was purified by reprecipitation with toluene / methanol again.
An electrophotographic photoreceptor was prepared in the same manner as described above. Resin ηinh =
1.25, the amount of residual catalyst in the resin was 40 ppm (the amount of residual catalyst in the charge transport layer was 22 ppm).

Example 6 In the procedure of the above-mentioned synthesis example as a binder resin, the polymerization catalyst was changed to tetramethylammonium chloride (TBAC) and a monomer to change the compound example (1-
The polymer of 4) was obtained. Example 4 was repeated except that the polymer was purified by reprecipitation with toluene / methanol again.
An electrophotographic photoreceptor was prepared in the same manner as described above. Resin ηinh =
1.25, the amount of residual catalyst in the resin was 40 ppm (the amount of residual catalyst in the charge transport layer was 22 ppm).

Example 7 In the procedure of the above synthesis example, the polymerization catalyst was triethylammonium bromide (T
Compound Example (1-2) /
(1-17) An electrophotographic photoreceptor was prepared in the same manner as in Example 4, except that the obtained polymer was re-precipitated and purified with toluene / methanol again. Resin ηinh = 1.55, residual catalyst amount in resin is 10
ppm (6 ppm of residual catalyst in the charge transport layer).

Example 8 Compound Example (1-3) was obtained as a binder resin by changing the polymerization catalyst in the procedure of the above Synthesis Example to trimethylbenzylammonium chloride (TMBAC) and a monomer. Reprecipitation purification was performed only once.
An electrophotographic photosensitive member was prepared in the same manner as in Example 4 except that this polymer was used. Resin ηinh = 0.71, residual catalyst amount in resin is 70 ppm (remaining catalyst amount in charge transport layer 39p
pm).

Comparative Example 3 An electrophotographic photoreceptor was prepared in the same manner as in Example 4, except that Compound No. (1-3) was used as a binder resin without isolation and without purification. Resin ηinh = 1.35, residual catalyst amount in resin is 250 ppm
(139 ppm of residual catalyst in the charge transport layer).

Comparative Example 4 A polyarylate resin of Compound Example (1-3) was synthesized as a binder resin by a melt polymerization method. Polymerization is JP-B-38-
The method was carried out by heating dicarboxylic acid and bisphenol in the presence of acetic anhydride with reference to JP-A-26299. The end point of the polymerization was defined as a point at which the viscosity of the reaction system increased and stirring became impossible. Resin ηinh = 0.45. An electrophotographic photosensitive member was prepared in the same manner as in Example 4 except that this polymer was used.

[0082]

[Table 6]

As is clear from Table 6, the electrophotographic photoreceptor of the present invention was able to suppress the amount of abrasion and obtain a good image as in Examples 4 to 8. On the other hand, in Comparative Example 3, since the amount of the residual catalyst was large, the light portion potential increased during repeated use, resulting in a low image density.
Also, in Example 8, the dissolution partition ratio in the organic phase was small (the partition ratio in the aqueous phase was high) by using the substituent of the catalyst as a methyl group.
Polymerization was carried out using a system in which the catalyst was more easily transferred to the aqueous phase, so that the catalyst remaining in the polymer could be reduced even in a single purification step. However, the progress of the polymerization reaction was considered to be relatively small, and the viscosity was relatively low. for that reason,
Although the amount of wear in the repeated use of the photoreceptor was relatively large, a good image was obtained in this evaluation note. Further, in Comparative Example 4, the polymerization method was changed, but a sufficient molecular weight was not obtained as a binder resin for the photoreceptor, and a good image was obtained due to a flaw generated on the surface of the photoreceptor and a change in image density due to potential fluctuation. No longer available.

Example 9 Bragg angle 2θ ± 0.2 in CuKα characteristic X-ray diffraction
Oxytitanium phthalocyanine 4 having strong peaks at 9.0 °, 14.2 °, 23.9 ° and 27.1 °
Part, polyvinyl butyral (trade name ESLEK BX1,
2 parts of Sekisui Chemical Co., Ltd.) and cyclohexanone 60
Part is 4 mm with a sand mill using 1 mmφ glass beads.
After time dispersion, 100 parts of ethyl acetate was added to prepare a charge generation layer coating. This coating material was applied on the intermediate layer by a dip coating method, and dried to form a charge generation layer having a thickness of 0.1 μm.

Next, the polymer obtained as Compound Example (1-6) was changed by changing the bisphenol monomer used in the procedure of the above Synthesis Example as the binder resin, and the polymer (ηi) was purified by reprecipitation with toluene / methanol again.
nh = 1.85, residual catalyst amount 90 ppm)
A charge transport layer and a film thickness of 23 were formed in the same manner as in Example 1, and an electrophotographic photosensitive member was formed. (Amount of residual catalyst in charge transport layer 4
7 ppm).

As an apparatus to be evaluated, a laser beam printer Laser Jet manufactured by Hulett Packard Company was used.
Using 4000 (a process of applying a DC voltage and an AC voltage from a charging member in contact with the electrophotographic photosensitive member to charge the photosensitive member: reversal development 94 mm / sec), 10,000 sheets intermittently Endurance was performed.

Example 10 Compound Example (1-2) in which the bisphenol monomer used as the binder resin in the procedure in the above Synthesis Example was changed.
An electrophotographic photoreceptor was prepared in the same manner as in Example 9, except that the polymer obtained with / (1-13) = 5/5 was used as a polymer which was subjected to reprecipitation purification with toluene / methanol again. ηinh = 1.76, residual catalyst amount 75 ppm (remaining catalyst amount in the charge transport layer 39 ppm).

Example 11 Compound Example (1-2) in which the bisphenol monomer used as the binder resin in the procedure in the above Synthesis Example was changed.
An electrophotographic photoreceptor was prepared in the same manner as in Example 9, except that the polymer obtained with / (1-18) = 7/3 was used as a polymer which was subjected to reprecipitation purification with toluene / methanol again. ηinh = 1.65, residual catalyst amount 70 ppm (residual catalyst amount in the charge transport layer 37 ppm).

Example 12 As a binder resin, an example of the compound (1-
Example 4 was repeated except that the polymer obtained in 2) was subjected to reprecipitation purification with toluene / methanol again.
An electrophotographic photoreceptor was prepared in the same manner as described above. ηinh = 1.0
4. Amount of residual catalyst 18 ppm (amount of residual catalyst 9 in charge transport layer 9)
ppm).

Comparative Example 5 The compound example (1-
An electrophotographic photosensitive member was prepared in the same manner as in Example 4, except that the polymer obtained in 2) was used. ηinh = 0.95,
350 ppm of residual catalyst (18 ppm of residual catalyst in the charge transport layer)
4 ppm).

Comparative Example 6 The compound example (1-
An electrophotographic photosensitive member was prepared in the same manner as in Example 4, except that the polymer obtained in 2) was used. ηinh = 0.51,
80 ppm of residual catalyst (42 p of residual catalyst in the charge transport layer)
pm).

[0092]

[Table 7]

As is clear from Table 7, the electrophotographic photoreceptor of the present invention was able to suppress the amount of abrasion and obtain a good image as in Examples 9 to 12. On the other hand, in Comparative Example 5, since the amount of the residual catalyst was large, the light portion potential increased during repeated use, and the image density became low. Further, in Comparative Example 6, a low molecular weight did not provide a sufficient molecular weight as a binder resin for a photoreceptor, and a polymer strength was not obtained. As a result, an increase in the amount of wear and scratches occurred.

[0094]

The electrophotographic photoreceptor of the present invention has a remarkable effect of providing more stable characteristics when repeatedly used in an electrophotographic process requiring high speed, high image quality and high durability. This effect can be obtained in an electrophotographic apparatus having the electrophotographic photosensitive member.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an electrophotographic apparatus having a process cartridge having an electrophotographic photosensitive member according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electrophotographic photosensitive member of the present invention 2 axis 3 primary charging means 4 exposure light 5 developing means 6 transfer means 7 transfer material 8 image fixing means 9 cleaning means 10 pre-exposure light 11 process cartridge 12 rail

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hidetoshi Hirano 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Harunobu Ogaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside (72) Inventor Hideki Anayama 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. F-term (reference) 2H003 BB11 CC05 DD03 2H068 AA13 BB27 EA04 FA01

Claims (9)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein the resin for forming the photosensitive layer is at least an interfacial weight using a phase transfer catalyst from an aromatic diol and an aromatic dicarboxylic acid halide. A polyarylate resin represented by the following general formula (1) synthesized by a legal method, wherein the inherent viscosity value of the resin is 0.7 to 2.0, and the amount of residual catalyst in the resin is 100 ppm or less. An electrophotographic photoreceptor, comprising: General formula (1) (Wherein, R _{1 to} R ₄ represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an aryl group, an alkoxy group having 1 to 5 carbon atoms or a halogen atom, X represents a single bond, —CR ₅ —R ₆ R ₅ and R _{6 each} represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, or an alkylidene group formed by bonding R ₅ and R _6. ) 2. The electrophotographic photosensitive member according to claim 1, wherein the amount of the phase transfer catalyst remaining in the photosensitive layer comprising the photosensitive material and the polyarylate resin is 60 ppm or less. 3. The following general formula (2) as a phase transfer catalyst:
3. The electrophotographic photoreceptor according to claim 1, wherein a quaternary ammonium salt represented by the formula (1) is used. General formula (2) (Wherein, R _{11 to} R ₁₃ represent an alkyl group having 1 to 5 carbon atoms, R ₁₄ represents an alkyl group or an aromatic substituted alkyl group, and X represents a halogen atom.) 4. The following general formula (3) as a phase transfer catalyst:
3. The electrophotographic photoreceptor according to claim 1, wherein a phosphonium salt represented by the following formula is used. General formula (3) (In the formula, R _{15 to} R ₁₇ represent an alkyl group having 1 to 5 carbon atoms, R ₁₈ represents an alkyl group or an aromatic substituted alkyl group, and X represents a halogen atom.) 5. The electrophotographic photosensitive member according to claim 1, wherein the resin for forming the photosensitive layer is at least a polyarylate copolymer resin represented by the following structural unit (1). Structural unit (1) 6. The electrophotographic photosensitive member according to claim 1, wherein the resin for forming the photosensitive layer is a polyarylate copolymer resin represented by at least the following structural unit (2). Structural unit (2) Embedded image 7. An electrophotographic apparatus main body, wherein the electrophotographic photosensitive member according to claim 1 and at least one unit selected from the group consisting of a charging unit, a developing unit and a cleaning unit are integrally supported. A process cartridge which is detachably mounted on a process cartridge. 8. The process according to claim 7, wherein the process cartridge has a charging means, and the charging means is arranged in contact with the electrophotographic photosensitive member, and charges the electrophotographic photosensitive member by applying only a DC voltage. cartridge. 9. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, a charging unit, an exposing unit, a developing unit, and a transferring unit.