JP2008248145A - Method for producing dispersion liquid, the dispersion liquid, dispersion liquid for coating electrophotographic photoreceptor using the dispersion liquid, electrophotographic photoreceptor formed by using the dispersion liquid for coating electrophotographic photoreceptor, process cartridge, and electrophotographic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing dispersion liquid excellent in dispersion stability and coating stability of an organic pigment, the dispersion liquid, a dispersion liquid for coating electrophotographic photoreceptor by using the dispersion liquid, an electrophotographic photoreceptor formed by using the dispersion liquid for electrophotographic photoreceptor, a process cartridge, and an electrophotographic device. <P>SOLUTION: The invention relates to the method for producing dispersion comprising preparation of the dispersion liquid by dispersing an organic pigment and a gelled polyamide resin in an organic solvent, and relates to the dispersion liquid, dispersion liquid for coating electrophotographic photoreceptor prepared by using the dispersion liquid, the electrophotographic photoreceptor formed by using the dispersion liquid for electrophotographic photoreceptor, a process cartridge, and electrophotographic device. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a dispersion comprising dispersing an organic pigment and a gelled polyamide resin in a solvent, and an electrophotographic photosensitive member using the dispersion and the dispersion The present invention relates to a dispersion for coating. Furthermore, the present invention relates to an electrophotographic photoreceptor formed using the electrophotographic photoreceptor dispersion of the present invention. The present invention further relates to a process cartridge and an electrophotographic apparatus using the electrophotographic photosensitive member of the present invention.

  Organic pigments such as azo pigments typified by monoazo pigments and disazo pigments and polycyclic pigments typified by phthalocyanine pigments generally settle out because of their lower specific gravity compared to inorganic pigments such as titanium oxide. It has the advantage of high liquid stability due to difficulty. In addition, it has advantages such as various absorption wavelengths by modifying to a unique molecular structure, industrially synthesized by chemical reaction, and maintaining high quality with high purity, and various printing inks and photosensitive properties can be applied as dyes. It is used for optical disks, solar cells, electrophotographic materials and the like.

  Polyamide resins have good mechanical properties and chemical resistance, and are used in a wide range of fields as electronic parts, automobile parts, fibers, and films as engineering plastics. Among these, alcohol-soluble polyamide resins such as N-alkoxyalkylated nylon and copolymer nylon, which are polyamide resins modified so as to increase solubility in alcohol, have characteristics such as transparency, flexibility, and adhesiveness. Due to this feature, it is used for surface treatment of clothing, adhesives for electronic materials, water-based inks, electrophotographic materials and the like.

  The coating surface of the dispersion liquid in which the organic pigments such as the azo pigments and polycyclic pigments described above are dispersed in a small particle diameter in the alcohol-based liquid of the alcohol-soluble polyamide resin has no coating unevenness and gives a glossy feeling. . However, in an alcohol-based liquid of an alcohol-soluble polyamide resin, obtaining an organic pigment such as an azo pigment or a polycyclic pigment described above as a dispersion having a small particle size for a long period of time is because the organic pigment itself aggregates. It may occur and is very difficult.

  In addition, the electrophotographic photosensitive member using the organic electrophotographic material as described herein is pollution-free and easy to manufacture as compared with conventional electrophotographic photosensitive members using inorganic electrophotographic materials such as Se and CdS. There is an advantage that the degree of freedom in functional design is high due to the variety of selection of materials. An electrophotographic photosensitive member using such an organic electrophotographic material has been widely used in the market due to the rapid spread of laser beam printers and copying machines in recent years.

  An electrophotographic photoreceptor basically comprises a photosensitive layer that forms a latent image by exposure using charging and light, and a support as a support member for providing the photosensitive layer. In general, when a photosensitive layer is directly formed on a support, dirt, shape and property non-uniformity, and roughness of the support surface appear as film formation unevenness of the photosensitive layer as they are. As a result, image defects such as white spots, black spots, and density unevenness occur in the resulting image, and the photosensitive layer peels off from the support.

  To date, an undercoat layer has been provided between the support and the photosensitive layer in order to ensure adhesion to the support, protect the photosensitive layer from electrical breakdown, and improve the carrier injection property of the photosensitive layer. I have been. This undercoat layer has the above-mentioned merits, but also has a demerit that charges are easily accumulated because it inhibits the charge transfer between the support and the photosensitive layer. For this reason, the potential fluctuation becomes large during continuous printing, causing image defects.

  Various methods have been proposed for further suppressing potential fluctuations due to an increase in residual potential during continuous printing, a decrease in initial potential, or the like when an electrophotographic photosensitive member provided with such an undercoat layer is used. However, there are many cases where the initial sensitivity is lowered, the charging ability is lowered, and there is a harmful effect, and the requirements are completely satisfied in the endurance use under a specific environment such as a high temperature and high humidity environment or a low temperature and low humidity environment. The current situation is that it cannot be said (see, for example, Patent Documents 1-7).

  Recently, with the progress of high-quality color printing in printers and copiers, the demands on the quality of electrophotographic photoreceptors have increased, and there are no image defects. There is a demand for an electrophotographic photosensitive member that does not cause changes in characteristics such as fluctuations. In such a flow, various methods for dispersing the organic pigment in the undercoat layer have been proposed in order to further improve the properties of the undercoat layer. For example, low residual potential (refer to Patent Document 8), suppression of increase in residual potential during repeated use (refer to Patent Document 9), stable chargeability from the first print rotation process (refer to Patent Document 10), potential during continuous printing This is to suppress fluctuations and ghosts (see Patent Documents 11-13).

However, these proposals use a pigment dispersion. For this reason, the film thickness of the electrophotographic photosensitive member becomes non-uniform due to local solid content fluctuations of the dispersion due to sedimentation of the dispersed pigment particles and increase in particle size due to aggregation of the dispersed pigment particles. There is a potential problem that density unevenness and image defects increase. Such density unevenness and image defects can be fatal defects of the electrophotographic photosensitive member in improving the image quality of the above-described printer and copying machine. In addition, there is a problem that the paint life of the dispersion liquid is shortened due to the sedimentation and aggregation of the dispersed pigment particles, and further stabilization of the dispersion state of the dispersion liquid is required to solve these problems.
Japanese Patent Laid-Open No. 62-269966 JP-A-62-279347 Japanese Patent Publication No. 7-72806 Japanese Patent Publication No. 02-059458 Japanese Patent No. 3010601 JP-A-5-27469 JP 7-175249 A Japanese Patent No. 3384231 Japanese Patent Publication No.7-111586 Japanese Patent No. 3417145 Japanese Patent No. 3774673 JP 2003-316049 A WO 2005/116777

  The present invention has been made in view of the above problems of the background art. That is, an object of the present invention is to provide a method for producing a dispersion having a small particle size of the organic pigment and exhibiting very excellent dispersion stability and coating property, and the dispersion. Another object of the present invention is to provide an electrophotographic photosensitive member formed by using the dispersion liquid, which has less bright portion potential and residual potential fluctuation and image defects during continuous printing. Still another object of the present invention is to provide a process cartridge and an electrophotographic apparatus using the electrophotographic photosensitive member.

As a result of intensive studies to solve the above problems, the present inventors have paid attention to a polyamide resin used for producing a dispersion obtained by dispersing an organic pigment and a polyamide resin. That is, in the production of the dispersion, a polyamide resin gelled as a polyamide resin is used for dispersion with an organic pigment. As a result, the volume average particle diameter (D ₅₀ ) of the organic pigment in the measurement value of the dispersion by the dynamic light scattering method and the average particle diameter (median diameter) of the organic pigment in the measurement value by the centrifugal sedimentation method are made extremely small. It was found that the dispersion stability can be maintained over a longer period. In addition, by forming an electrophotographic photosensitive member using a dispersion liquid for coating an electrophotographic photosensitive member using the dispersion liquid, an electrophotographic photosensitive member having less potential fluctuations in the bright portion and residual potential and image defects during continuous printing. The present invention was completed by finding that a body can be provided. Furthermore, the present inventors have found that a process cartridge and an electrophotographic apparatus using the electrophotographic photosensitive member can be provided, and the present invention has been completed.

  That is, the present invention is as follows.

  A method for producing a dispersion, comprising preparing a dispersion by dispersing an organic pigment and a gelled polyamide resin in a solvent.

The method for producing a dispersion of the present invention uses a gelled polyamide resin for dispersion with an organic pigment. As a result, the volume average particle diameter (D ₅₀ ) in the measurement value of the dispersion by the dynamic light scattering method and the average particle diameter (median diameter) in the measurement value by the centrifugal sedimentation method can be extremely reduced. There is a remarkable effect that the dispersion stability can be maintained. In addition, according to the present invention, by forming an electrophotographic photosensitive member using the dispersion liquid for coating an electrophotographic photosensitive member using the dispersion liquid, the potential variation of bright portion potential and residual potential during continuous printing and image An electrophotographic photosensitive member with few defects can be provided. In addition, a process cartridge and an electrophotographic apparatus using the electrophotographic photosensitive member can be provided.

  Hereinafter, embodiments of the present invention will be described in detail.

  The method for producing a dispersion of the present invention is a method produced by dispersing an organic pigment and a gelled polyamide resin in a solvent.

  The method for producing a dispersion of the present invention preferably includes the following steps.

A. Preparing a polyamide resin gelled (gelled) using an alcohol solvent and a polyamide resin;
B. Next, the gelled (gelled) polyamide resin is optionally crushed to a size of 0.5 mm or more and 10 mm or less;
C. Next, an organic pigment and the gelled (gelled) polyamide resin are dispersed;
D. The resulting dispersion is then filtered if desired and diluted by adding a solvent if desired.

  The “gelled polyamide resin” described here is defined by the result of measuring a polyamide resin under the following measurement conditions using a thermal stress strain measuring device TMA / SS150CU (manufactured by Seiko Instruments Inc.). That is, penetration measurement is performed to measure the deformation amount (TMA) of the polyamide resin while changing the load (LOAD) applied to the polyamide resin at a constant rate. As a result of the measurement with a needle, it is defined as a polyamide resin in which an inflection point is observed in the deformation amount (TMA) of the polyamide resin within the range of the sample length of the polyamide resin (FIG. 3). The inflection point is the amount of deformation of the polyamide resin in which the TMA deformation amount (DTMA) per unit time satisfies 1.5 mm / min or more and the TMA deformation amount (DTMA) per unit time is the maximum value ( TMA). The load (LOAD) applied to the polyamide resin at the inflection point is the value of the load (LOAD) applied to the polyamide resin at the time when the TMA deformation amount (DTMA) per unit time shows the maximum value. FIG. 3 is a diagram showing an example of the relationship between LOAD, TMA, and DTMA in the penetration measurement of gelled polyamide resin, where the horizontal axis is LOAD, the solid line is TMA, and the broken line is DTMA. The polyamide resin which is not gelled is also known from the deformation amount (TMA) of the sample in the penetration measurement measured under the following conditions using a thermal stress strain measuring apparatus TMA / SS150CU (manufactured by Seiko Instruments Inc.). That is, in the polyamide resin which is not gelled, no inflection point is observed in the deformation amount (TMA) of the polyamide resin within the range of the sample length of the polyamide resin (FIG. 4).

  The polyamide resin used for the measurement satisfies the sample length and cross-sectional area shown below, and the measurement surface that contacts the needle probe is made parallel to the surface that contacts the sample table, and there are no bubbles, cracks, or foreign matter. Use things. Moreover, when the polyamide resin sample used for the measurement has fluidity, it can be measured by putting it in a sample cup having a size on the sample stage.

  The sample length of the polyamide resin can be set by the automatic measurement in which the detection mode is the compression mode and the load at the time of measurement is -2 (mN). If automatic length measurement is not possible, set the sample length of the polyamide resin directly. The polyamide resin used for the penetration measurement may be a polyamide resin alone or may contain a solvent.

(TMA / SS150CU measurement conditions)
Measurement method: Penetration measurement Measurement mode: Assembly F control mode (without temperature control)
Probe to be used: Needle-in probe sample holder, sample stand material: quartz sample length: polyamide resin sample length (appropriate length is 3-5 mm)
Sample cross-sectional area: about 0.8 cm2 Measurement temperature: 25 ± 2 ° C (room temperature)
Measurement atmosphere: SS program setting in air:
End step: 1
Step 1 conditions: start load -2 (mN), limit load -482 (mN), load rate 30 (mN / min), holding time 0.00 (min)

  As the organic pigment, conventionally known pigments such as monoazo, bisazo, trisazo, and tetrakisazo pigments, phthalocyanine pigments such as gallium phthalocyanine and titanyl phthalocyanine, and perylene pigments can be used. Of these, phthalocyanine pigments and azo pigments are preferred. Moreover, these organic pigments can be used alone or in combination of two or more.

  The phthalocyanine pigment is preferably a hydroxygallium phthalocyanine crystal having strong peaks at positions of Bragg angles 2θ = 7.4 ° ± 0.3 ° and 2θ = 28.2 ° ± 0.3 ° in CuKα characteristic X-ray diffraction. .

As the azo pigment, a bisazo pigment represented by the following general formula (1) is preferable.
General formula (1)
Cp-N = N-Ar-N = N-Cp
(In the formula, Cp represents a phenolic coupler, and Ar represents an aromatic hydrocarbon ring or an aromatic heterocycle having or not having a substituent, which is bonded via a linking group or bonded via a linking group. To express.)
The bisazo pigment represented by the general formula (1) is preferably represented by the following general formula (2).

  The bisazo pigment represented by the general formula (1) is preferably represented by the following general formula (3).

(In general formula (3), Ar represents any group of the following general formula (4), formula (5), or formula (6)).

(In General Formula (3), R ₁ and R ₂ each independently represent a hydrogen atom, an aryl group which may have a substituent, or a carbamoyl group which may have a substituent, provided that R ₁ and R ₂ is not simultaneously a hydrogen atom, X represents O or S. Y is condensed with a benzene ring to form an optionally substituted aromatic hydrocarbon ring or aromatic heterocyclic ring. In general formula (4), R ₃ , R ₄ , R ₅ , R ₆ and R ₇ may each independently have a hydrogen atom, a halogen atom or a substituent. A good alkyl group, an aralkyl group which may have a substituent or an aryl group which may have a substituent, A represents O, S or N—R ₈ , where R ₈ is a hydrogen atom, a substituent An alkyl group optionally having a group, an aralkyl optionally having a substituent Or an aryl group which may have a substituent.)

  The gelled polyamide resin can be prepared by combining the following conditions after the polyamide resin alone or the polyamide resin is dissolved by heating in a solvent.

  (1) Type of polyamide resin: The type of polyamide resin is not particularly limited as long as a desired gelled polyamide resin can be prepared. As a kind of polyamide resin, nylon 6, nylon 11, nylon 12, nylon 66, nylon 610, N-methoxymethylated 6 nylon can be used, for example. Further, conventionally known ones such as N-alkoxyalkylated nylon represented by N-methoxymethylated 12 nylon and nylon copolymer represented by quaternary nylon copolymer of nylon 6-66-610-12 are used. be able to. The type of polyamide resin is determined in consideration of the solubility in a solvent for gelling the polyamide resin and the ease of gelation of the polyamide resin. One type or two or more types of polyamide resins can be used in combination. The kind of polyamide resin preferably includes at least N-alkoxyalkylated nylon, and more preferably includes at least N-alkoxyalkylated nylon having an N-alkoxyalkylation rate of 20% to 45%. Moreover, it is particularly preferable that N-methoxymethylated nylon having at least an N-methoxymethylation rate of 20% to 45% is included. In addition, N-methoxymethylation rate was measured by the method shown below by NMR. N-alkoxyalkylated nylon, which is a type of polyamide resin, has a repetitive unit of the nylon main chain as compared with copolymer nylon in which a plurality of types of nylon are chemically bonded to the main chain. Therefore, it is easy to prepare a gelled polyamide resin having excellent crystallinity. Further, when the N-alkoxyalkylated nylon has an N-alkoxyalkylation rate lower than 20%, the solubility in a solvent is lowered, and it may be difficult to prepare a gelled polyamide resin. When the N-alkoxyalkylation rate is higher than 45%, the solubility in a solvent increases, and the stability of the gelled polyamide resin may deteriorate.

<Measurement method of N-methoxymethylation rate>
apparatus:
Measuring apparatus: FT NMR apparatus JNM-EX400 (manufactured by JEOL Ltd.)
Measurement frequency: 400MHz
Pulse condition: 5.0 μS
Data points: 32768
Frequency range: 10500Hz
Integration count: 32 times Measurement temperature: 25 ° C
sample:
N-methoxymethylated nylon 25mg
Methanol-D4 (99.8 atom% D) 0.75 ml made by Aldrich
Tetramethylsilane (internal standard) 0.05% by weight based on methanol-D4
Method of calculation:
A: Integral value of methylene proton (ca.2.4 ppm) adjacent to the carbonyl portion of the amide group which is N-methoxymethylated B: Methylene proton (ca) adjacent to the carbonyl portion of the amide group which is not N-methoxymethylated 2.2 ppm) N-methoxymethylation rate (%) = A / (A + B) × 100

  (2) Temperature for gelling the polyamide resin: The temperature for gelling the polyamide resin is not particularly limited as long as the desired gelled polyamide resin can be obtained. In order to obtain a stably gelled polyamide resin, it is desirable to cool the polyamide resin heated and dissolved in a solvent, and it is more desirable to cool to 30 ° C. or lower.

  (3) Solvent that gels the polyamide resin: The presence or type of the solvent is not particularly limited as long as the desired gelled polyamide resin can be prepared, but is preferably an alcohol solvent, more preferably an alcohol. Further, the solvent may be combined with one or more solvents in consideration of the solubility of the polyamide resin and the ease of preparation of the gelled polyamide resin.

  The alcohol solvent is preferably an alcohol, and more preferably a linear or branched alcohol having 1 to 6 carbon atoms. Moreover, it is particularly preferable to contain at least one of methanol, ethanol, isopropanol, 1-propanol, 1-butanol, 2-butanol and isobutanol.

  The gelled polyamide resin preferably contains N-methoxymethylated nylon and at least one of methanol, ethanol, isopropanol, 1-propanol, 1-butanol, 2-butanol and isobutanol. Moreover, it is more preferable to contain N-methoxymethylated nylon and 1-butanol.

  (4) Polyamide resin solid content of gelled polyamide resin: The polyamide resin solid content of the gelled polyamide resin is not particularly limited as long as a desired gelled polyamide resin can be prepared. Considering the stability of the gelled polyamide resin, the solid content of the polyamide resin is preferably 2% or more by mass%, more preferably 5% or more, and most preferably 5.0% or more and 30.0. % Or less. If the solid content of the polyamide resin is too low, a gelled polyamide resin may not be prepared.

  (5) Shape of gelled polyamide resin: The shape of the gelled polyamide resin is not particularly limited as long as a desired dispersion can be prepared. Considering workability in the dispersion operation, it is preferable to crush the gelled polyamide resin to a size of 0.5 mm or more and 10 mm or less before dispersion. If the gelled polyamide resin is smaller than 0.5 mm, the crushed gelled polyamide resins are likely to adhere to each other, and workability may be deteriorated. If the gelled polyamide resin is larger than 10 mm, an undispersed portion of the gelled polyamide resin may remain after the dispersion is completed. For crushing the gelled polyamide resin, a paint shaker, a ball mill, a sand mill, an ultrasonic disperser, a high-pressure homogenizer, a stirrer, a mixer, a stirrer, a roll mill, an emulsion disperser, a mesh, a sieve, a mincer, or the like is used.

  The dispersion is produced by dispersing the gelled polyamide resin and the organic pigment in a solvent. Considering the dispersibility of the dispersion, when the gelled polyamide resin and the organic pigment are dispersed, it is preferable to add a solvent to increase the fluidity of the dispersion during dispersion. In the dispersion, the solvent, the organic pigment and the gelled polyamide resin may be simultaneously dispersed, or only the organic pigment may be dispersed in advance in the solvent, and then the gelled polyamide resin may be added and dispersed. As the solvent, a polyamide resin liquid obtained by dissolving a polyamide resin in a solvent in advance may be used. As a dispersion method, a known method, for example, a method using a dispersion device such as a paint shaker, a ball mill, a sand mill, an ultrasonic disperser, a high-pressure homogenizer, a stirrer, a mixer, a stirrer, a roll mill, or an emulsifying disperser is used. Can do. The solvent preferably contains at least one of methanol, ethanol, isopropanol, 1-propanol, 1-butanol, 2-butanol and isobutanol.

  The mass ratio of the organic pigment and the polyamide resin contained in the dispersion is the stability of the dispersion and the effect of suppressing potential fluctuations in the bright part potential and residual potential during continuous printing of the electrophotographic photoreceptor formed using the dispersion. Is determined in consideration of The mass ratio of the organic pigment and the polyamide resin contained in the dispersion is preferably 1: 1000 or more and 2: 1 or less, more preferably the mass ratio of the organic pigment and the polyamide resin contained in the dispersion is 1: 100 or more and 1: 1 or less. When the mass ratio of the organic pigment and the polyamide resin contained in the dispersion is higher than 2: 1, the dispersibility of the pigment may deteriorate and the liquid stability of the dispersion may deteriorate. Further, when the mass ratio of the organic pigment and the polyamide resin contained in the dispersion is lower than 1: 1000, the effect of suppressing the potential fluctuation due to the increase in the residual potential or the decrease in the initial potential during continuous printing on the electrophotographic photosensitive member is obtained. It may be inferior.

  The solid content of the dispersion is determined in consideration of the stability and coating property of the dispersion, and is preferably 1% to 15% by mass%, more preferably 3% to 10%. If the solid content of the dispersion is higher than 15%, the fluidity of the dispersion may be lost, or the dispersibility may deteriorate and the liquid stability of the dispersion may decrease. If the solid content of the dispersion is lower than 1%, uneven application of the electrophotographic photosensitive member using the dispersion, image density unevenness due to film sagging, and the like may occur.

The volume average particle diameter (D ₅₀ ) of the dispersion was measured using “MICROTRAC PARTIPLE-SIZE ANALYZER 9340 UPA” (manufactured by Leeds & Northrup) based on the dynamic light scattering method, and was measured under the following conditions. is there. The dispersion was measured by diluting with ethanol so that the loading index value was 0.08 or more and 0.12 or less.

(Microtrack UPA measurement conditions)
Calculation and control program version: 4.53E
Mode: FullRange
Transparent Particles: Yes
Physical Particles: No
Particle Refractive Index: 1.51
Particle Density: 1.20g / cc
Fluid: Ethanol
Fluid Refractive Index: 1.33
Fluid High Temp: 30.0 ° C. Viscosity 1.003 mPa · s
Fluid Low Temp: 20.0 ° C. Viscosity 1.200 mPa · s
Run Time: 180sec

  The average particle diameter (median diameter) of the dispersion was measured using a centrifugal sedimentation type particle size distribution analyzer CAPA-700 (manufactured by Horiba, Ltd.) under the following conditions.

(CAPA-700 measurement conditions)
Solvent Ethanol DISP. VISC. 1.20 mPa · s
DISP. DENS. 0.79g / cc
SAMP. DENS. 1.20g / cc
D (MAX) 1.00μm
D (MIN) 0.10 μm
D (DIV) 0.05 μm
SPEED 7000rpm

  In addition, an electrophotographic photoreceptor formed using the dispersion obtained by the production method of the present invention is formed by laminating at least an undercoat layer and a photosensitive layer on a conductive support. Even if the photosensitive layer is a single-layer type photosensitive layer (FIG. 1A) containing the charge transport material and the charge generation material in the same layer, the charge generation layer and the charge transport material containing the charge generation material are used. It may be a laminated type (functionally separated type) photosensitive layer (FIG. 1B) separated into a charge transport layer contained therein. From the viewpoint of electrophotographic characteristics, a laminated photosensitive layer is preferred. 1A and 1B, reference numeral 101 denotes a support, 102 denotes an undercoat layer, 103 denotes a photosensitive layer, 104 denotes a charge generation layer, and 105 denotes a charge transport layer. In the following, an electrophotographic photoreceptor containing a laminated (functionally separated type) photosensitive layer will be described in detail.

  The conductive support only needs to have conductivity, and examples thereof include metals such as aluminum, stainless steel, and nickel, or metals provided with a conductive layer, plastics, paper, and the like. Can be mentioned. In particular, cylindrical aluminum is excellent in terms of mechanical strength, electrophotographic characteristics, and cost. These conductive supports may be used as they are, but those subjected to physical treatment such as cutting and honing, anodizing treatment, or chemical treatment using acid or the like may be used. Among them, by performing physical processing such as cutting or honing, the surface roughness is processed to be 0.1 μm or more and 3.0 μm or less in terms of Rz value, thereby providing an interference fringe prevention function.

  An interference fringe preventing layer (not shown in FIG. 1) may be provided between the conductive support and the undercoat layer. The interference fringe prevention layer is not necessary when the support itself has an interference fringe prevention function, but by using the conductive support as it is and forming an interference fringe prevention layer by coating on it, An interference fringe preventing function can be imparted to the conductive support by a simple method. For this reason, it is very useful in terms of productivity and cost. As a preferable method for forming the interference fringe prevention layer, inorganic particles such as tin oxide, indium oxide, titanium oxide, and barium sulfate are dispersed in a suitable solvent together with a curable resin such as a phenol resin to prepare a coating liquid, and conductive Examples of the method include coating to a conductive support and drying. The thickness of the interference fringe prevention layer is preferably 1 μm or more and 20 μm or less.

  On the support or the interference fringe prevention layer, an undercoat layer is necessary for securing adhesion to the support, protecting the photosensitive layer from electrical breakdown, improving the carrier injection property of the photosensitive layer, and the like.

  The undercoat layer is formed by coating the dispersion composed of an organic pigment and a polyamide resin on a conductive support or an interference fringe prevention layer. The film thickness is preferably 0.01 μm or more and 30 μm or less, and more preferably 0.1 μm or more and 20 μm or less. By including the organic pigment in the undercoat layer, it is possible to suppress fluctuations in the bright part potential and the residual potential during continuous printing.

  As the charge generation material, azo pigments such as monoazo, bisazo, trisazo, and tetrakisazo, phthalocyanine pigments such as gallium phthalocyanine and titanyl phthalocyanine, and perylene pigments can be used. A gallium phthalocyanine pigment is preferable from the viewpoint of characteristic stability due to environmental fluctuations. More preferably, from the viewpoints of high sensitivity and optical memory characteristics, strong peaks at Bragg angles 2θ = 7.4 ° ± 0.3 ° and 2θ = 28.2 ° ± 0.3 ° in CuKα characteristic X-ray diffraction A hydroxygallium phthalocyanine crystal having

  The coating solution for the charge generation layer is prepared by the above-described known dispersion method using the above-described charge generation material as a suitable solvent. Suitable solvents include, for example, tetrahydrofuran, cyclohexanone, methyl ethyl ketone, ethyl acetate, methanol, methyl cellosolve, acetone, dioxane and N, N-dimethylformamide. At this time, a polymer substance may be added together as a binder, or the binder may be added after being dispersed in advance only with a pigment and a solvent.

  The binder can be selected from a wide range of insulating resins, and can also be selected from organic photoconductive polymers such as poly-N-vinyl carbazole, polyvinyl anthracene, and polyvinyl porene. Preferable examples include insulating resins such as polyvinyl butyral, polyarylate (such as a condensation polymer of bisphenol A and phthalic acid), polycarbonate, polyester, phenoxy resin, polyvinyl acetate, acrylic resin, and polyacrylamide resin. In addition, insulating resins such as polyamide, polyvinyl pyridine, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol, and polyvinyl pyrrolidone can be given.

  The charge generation layer is formed by applying a dispersion containing the above substances on the undercoat layer, and the film thickness is preferably 5 μm or less, and particularly preferably 0.05 μm or more and 1 μm or less.

  The charge transport layer is formed by applying and drying a paint in which a charge transport material and a binder are mainly dissolved in a solvent.

  Examples of the charge transport material used include various triarylamine compounds, hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, triallylmethane compounds, and the like. A binder may be added after preliminarily dispersing and dissolving only with the charge transport material and the solvent. Moreover, what was mentioned above can be used as a binder.

  The thickness of the charge transport layer is preferably 5 μm or more and 40 μm or less, and more preferably 10 μm or more and 30 μm or less.

  When the charge transport layer is a single layer, it can be formed similarly using the above-described substances, and the film thickness is preferably 5 μm or more and 40 μm or less, and particularly preferably 10 μm or more and 30 μm or less.

  In the present invention, a protective layer may be provided on the charge transport layer for the purpose of improving durability, transferability and cleaning properties.

  The protective layer can be formed by applying and drying a protective layer coating solution obtained by dissolving a resin in an organic solvent. Examples of the resin include polyvinyl butyral, polyester, polycarbonate, polyamide, and polyimide. Also included are polyarylate, polyurethane, styrene-butadiene copolymer, styrene-acrylic acid copolymer, styrene-acrylonitrile copolymer, and the like.

  Further, in order to provide the protective layer with the charge transport ability, the protective layer may be formed by curing a monomer material having a charge transport ability or a polymer type charge transport material using various crosslinking reactions. . Examples of the curing reaction include radical polymerization, ionic polymerization, thermal polymerization, photopolymerization, radiation polymerization (electron beam polymerization), plasma CVD, and photo CVD.

  Furthermore, you may include electroconductive particle, a ultraviolet absorber, an abrasion resistance improving agent, etc. in a protective layer. As the conductive particles, for example, metal oxides such as tin oxide particles are preferable. As the wear resistance improver, fluorine resin fine powder, alumina, silica and the like are preferable.

  The thickness of the protective layer is preferably 0.5 μm or more and 20 μm or less, and particularly preferably 1 μm or more and 10 μm or less.

  As a coating method of these various layers, a dipping method, a spray coating method, a spinner coating method, a bead coating method, a blade coating method, a beam coating method, and the like can be used.

  FIG. 2 shows a schematic configuration of an electrophotographic apparatus provided with a process cartridge having the electrophotographic photosensitive member of the present invention.

  In FIG. 2, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is rotationally driven around a shaft 2 at a predetermined peripheral speed (process speed) in the direction of an arrow. In the rotation process, the electrophotographic photosensitive member 1 is uniformly charged at a predetermined positive or negative potential on its peripheral surface by the primary charging unit 3. Next, the exposure light 4 intensity-modulated in response to a time-series electric digital image signal of target image information output from image exposure means (not shown) such as slit exposure or laser beam scanning exposure is received. In this way, electrostatic latent images corresponding to the target image information are sequentially formed on the peripheral surface of the electrophotographic photoreceptor 1.

  The formed electrostatic latent image is then visualized as a transferable particle image (toner image) by regular development or reversal development with charged particles (toner) in the developing means 5. Next, the electrophotographic photosensitive member 1 is transferred to a transfer material 7 which is taken out from a paper feeding unit (not shown) between the electrophotographic photosensitive member 1 and the transfer means 6 in synchronization with the rotation of the electrophotographic photosensitive member 1 and fed. The toner images formed and supported on the surface are sequentially transferred by the transfer means 6. At this time, a bias voltage having a polarity opposite to the charge held in the toner is applied to the transfer means from a bias power source (not shown).

  The transfer material 7 that has received the transfer of the toner image is separated from the surface of the electrophotographic photosensitive member, conveyed to the image fixing means 8, and subjected to a toner image fixing process to be printed out of the apparatus as an image formed product (print, copy). Out.

  The surface of the electrophotographic photosensitive member 1 after the transfer of the toner image is cleaned by removing the deposits such as residual toner by the cleaning means 9. In recent years, a cleanerless system has been studied, and the transfer residual toner can be directly collected by a developing device or the like. Further, after being subjected to charge removal processing by pre-exposure light 10 from pre-exposure means (not shown), it is repeatedly used for image formation. When the primary charging unit 3 is a contact charging unit using a charging roller or the like, pre-exposure is not always necessary.

  In the present invention, among the above-described components such as the electrophotographic photosensitive member 1, the primary charging unit 3, the developing unit 5 and the cleaning unit 9, a plurality of components are housed in a container and integrally combined as a process cartridge. May be. In addition, the 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, at least one of the primary charging unit 3, the developing unit 5, and the cleaning unit 9 is integrally supported together with the electrophotographic photosensitive member 1 to form a cartridge, and is attached to and detached from the apparatus main body using the guide unit 12 such as a rail of the apparatus main body. A flexible process cartridge 11 can be obtained.

  When the electrophotographic apparatus is a copying machine or a printer, the original is read and reflected by reflected light or transmitted light from the original or a sensor. The exposure light 4 is light irradiated by scanning of a laser beam performed according to this signal, driving of an LED array, driving of a liquid crystal shutter array, or the like.

  The dispersion obtained using the method for producing a dispersion of the present invention is suitable for printing inks, aqueous paints, liquid toners, coating agents, adhesives, surface treatment agents and the like. In addition, the electrophotographic photoreceptor obtained by using the dispersion for coating an electrophotographic photoreceptor using the dispersion of the present invention is used in an electrophotographic copying machine. In addition, it can be widely applied to electrophotographic application fields such as laser beam printers, CRT printers, LED printers, FAX, liquid crystal printers, and laser plate making.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. However, embodiments of the present invention are not limited to these. In the examples, “parts” means “parts by mass”.

  First, the preparation method of the gelled polyamide resin used for manufacture of the dispersion liquid of this invention and the non-gelled polyamide resin is described.

<Preparation Example 1>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, degree of polymerization 420, methoxymethylation rate 36.8%) 2.5 parts 1-butanol (made by Kishida Chemical, special grade) 97.5 parts In the above configuration, N-methoxymethylated 6 nylon resin was dissolved by heating at 70 ° C., and the solution filtered through a polyflon filter (PF020, pore size 2 μm, manufactured by Advantech Toyo Co., Ltd.) was placed in a sealed container at 5 ° C. It was stored in a 5-day environment. Next, a gelled polyamide resin 1-1A in which an inflection point was observed in TMA in the penetration measurement using the above-described thermal stress strain measuring apparatus TMA / SS150CU was prepared. Also, the LOAD and DTMA maximum values at the inflection points were confirmed.

  Further, the state of the gelled polyamide resin 1-1A was qualitatively evaluated by visual observation. The result of the evaluation is that the gelled polyamide resin has a slightly white color and loses fluidity, and the gelled polyamide resin has a white turbidity and loses fluidity. " The results are shown in Table 1.

<Preparation Example 2>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, degree of polymerization 420, methoxymethylation rate 36.8%) 5 parts 1-butanol (made by Kishida Chemical, special grade) 95 parts In the above configuration, gelation was carried out using the same method as in Preparation Example 1, except that it was changed from standing storage at 5 ° C. for 5 days to 23 ° C. for 3 days in Preparation Example 1. Polyamide resin 1-2A was prepared and measured and evaluated in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 3>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, methoxymethylation rate: 36.8%) 7.5 parts 1-butanol (made by Kishida Chemical, special grade) 92.5 Part Gelation using the same method as in Preparation Example 1, except that in Preparation Example 1, the sample was stored at 5 ° C. for 5 days in place of the stationary storage at 23 ° C. for 1 day. The prepared polyamide resin 1-3A was prepared and measured and evaluated in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 4>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, degree of polymerization 420, methoxymethylation rate 36.8%) 10.0 parts 1-butanol (made by Kishida Chemical, special grade) 90.0 parts In the above configuration, the same method as in Preparation Example 1 was used, except that in Preparation Example 1, it was changed from standing storage at 5 ° C. for 5 days to 23 ° C. for 1 day. The gelled polyamide resin 1-4A was prepared and measured and evaluated in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 5>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, polymerization degree 420, methoxymethylation rate 36.8%) 12.5 parts 1-butanol (made by Kishida Chemical, special grade) 87.5 parts Using the same method as in Preparation Example 1 except that in the above-described configuration, the preparation was changed from standing storage at 5 ° C for 5 days to 23 ° C for 1 day. The gelled polyamide resin 1-5A was prepared and measured and evaluated in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 6>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, degree of polymerization 420, methoxymethylation rate 36.8%) 15.0 parts 1-butanol (made by Kishida Chemical, special grade) 85.0 parts Using the same method as in Preparation Example 1, except that in the above-mentioned configuration, the preparation was changed from standing storage at 5 ° C for 5 days to 23 ° C for 1 day. The gelled polyamide resin 1-6A was prepared and measured and evaluated in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 7>
N-methoxymethylated 6 nylon resin (trade name: Toresin F30K, manufactured by Nagase ChemteX Corporation, degree of polymerization 190, methoxymethylation rate 39.8%) 10.0 parts 1-butanol (made by Kishida Chemical, special grade) 90. 0 parts In the above-described configuration, gel was prepared in the same manner as in Preparation Example 1 except that it was changed from standing storage at 5 ° C for 5 days to 23 ° C for 5 days in Preparation Example 1. Polyamide resin 1-7A was prepared and measured and evaluated in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 8>
N-methoxymethylated 6 nylon resin (trade name: Toresin F30K, manufactured by Nagase ChemteX Corporation, degree of polymerization 190, methoxymethylation rate 39.8%) 20.0 parts 1-butanol (manufactured by Kishida Chemical, special grade) 80. 0 parts In the above-described configuration, gel was prepared in the same manner as in Preparation Example 1 except that it was changed from standing storage at 5 ° C. for 5 days to 23 ° C. for 1 day. Polyamide resin 1-8A was prepared and measured and evaluated in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 9>
N-methoxymethylated 6 nylon resin (trade name: Toresin MF-30, manufactured by Nagase ChemteX Corporation, degree of polymerization 320, methoxymethylation rate 39.4%) 10.0 parts 1-butanol (made by Kishida Chemical, special grade) 90.0 parts Using the same method as in Preparation Example 1, except that in the above-described configuration, the preparation was changed from standing storage at 5 ° C. for 5 days to standing storage at 23 ° C. for 5 days. The gelled polyamide resin 1-9A was prepared and measured and evaluated in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 10>
N-methoxymethylated 6 nylon resin (trade name: Toresin MF-30, manufactured by Nagase ChemteX Corporation, polymerization degree 320, methoxymethylation rate 39.4%) 20.0 parts 1-butanol (made by Kishida Chemical, special grade) 80.0 parts Using the same method as in Preparation Example 1, except that in the above-described configuration, in Example 1 of preparation, the static storage was changed to 5 ° C for 5 days, and the storage was changed to 23 ° C for 1 day. A gelled polyamide resin 1-10A was prepared and measured and evaluated in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 11>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, polymerization degree 420, methoxymethylation rate 36.8%) 30.0 parts methanol (made by Kishida Chemical Co., Ltd.) 0 parts With the above configuration, except that in Preparation Example 1, the heat dissolution at 70 ° C. to the heat dissolution at 50 ° C. and the static storage at 5 ° C. for 5 days was changed to the static storage at 23 ° C. for 5 days. A gelled polyamide resin 1-11A was prepared using the same method as in Preparation Example 1. Further, measurement and evaluation were performed in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 12>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, polymerization degree 420, methoxymethylation rate 36.8%) 10.0 parts ethanol (made by Kishida Chemical Co., Ltd.) 90. 0 parts With the above configuration, except that in Preparation Example 1, heat dissolution at 70 ° C. to heat dissolution at 60 ° C. and 5 ° C. for 5 days in static storage were replaced with 23 ° C. for 1 day in static storage. Using the same method as in Preparation Example 1, a gelled polyamide resin 1-12A was prepared. Further, measurement and evaluation were performed in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 13>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, degree of polymerization 420, methoxymethylation rate 36.8%) 20.0 parts ethanol (made by Kishida Chemical Co., Ltd.) 80. 0 parts With the above configuration, except that in Preparation Example 1, heat dissolution at 70 ° C. to heat dissolution at 60 ° C. and 5 ° C. for 5 days in static storage were replaced with 23 ° C. for 1 day in static storage. A gelled polyamide resin 1-13A was prepared using the same method as in Preparation Example 1. Further, measurement and evaluation were performed in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 14>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, degree of polymerization 420, methoxymethylation rate 36.8%) 10.0 parts 1-propanol (made by Kishida Chemical, special grade) 90.0 parts In the above configuration, the same method as in Preparation Example 1 was used, except that in Preparation Example 1, it was changed from standing storage at 5 ° C. for 5 days to 23 ° C. for 1 day. A gelled polyamide resin 1-14A was prepared and measured and evaluated in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 15>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, polymerization degree 420, methoxymethylation rate 36.8%) 20.0 parts 1-propanol (manufactured by Kishida Chemical, special grade) 80.0 parts Using the same method as in Preparation Example 1, except that in the above-described configuration, in Example 1 of preparation, the static storage was changed to 5 ° C for 5 days, and the storage was changed to 23 ° C for 1 day. A gelled polyamide resin 1-15A was prepared and measured and evaluated in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 16>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, degree of polymerization 420, methoxymethylation rate 36.8%) 5.0 parts isopropanol (manufactured by Kishida Chemical, special grade) 95. 0 parts With the above configuration, except that in Preparation Example 1, heat dissolution at 70 ° C. to heat dissolution at 65 ° C. and 5 ° C. for 5 days in static storage to 23 ° C. for 1 day in place of static storage A gelled polyamide resin 1-16A was prepared using the same method as in Preparation Example 1. Further, measurement and evaluation were performed in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 17>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, degree of polymerization 420, methoxymethylation rate 36.8%) 15.0 parts isopropanol (made by Kishida Chemical, special grade) 85. 0 parts With the above configuration, except that in Preparation Example 1, heat dissolution at 70 ° C. to heat dissolution at 65 ° C. and 5 ° C. for 5 days in static storage to 23 ° C. for 1 day in place of static storage Using the same method as in Preparation Example 1, a gelled polyamide resin 1-17A was prepared. Further, measurement and evaluation were performed in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 18>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, degree of polymerization 420, methoxymethylation rate 36.8%) 10.0 parts 2-butanol (made by Kishida Chemical, special grade) 90.0 parts In the above configuration, the same method as in Preparation Example 1 was used, except that in Preparation Example 1, it was changed from standing storage at 5 ° C. for 5 days to 23 ° C. for 1 day. Gelated polyamide resin 1-18A was prepared and measured and evaluated in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 19>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, degree of polymerization 420, methoxymethylation rate 36.8%) 10.0 parts isobutanol (made by Kishida Chemical, special grade) 90 0.0 parts In the same manner as in Preparation Example 1, except that in the above-mentioned configuration, the preparation was changed from standing storage at 5 ° C. for 5 days to 23 ° C. for 1 day. Gelled polyamide resin 1-19A was prepared and measured and evaluated in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 20>
Nylon 6-66-610-12 quaternary nylon copolymer resin (trade name: CM8000, manufactured by Toray Industries, Inc.) 15.0 parts 1-propanol (manufactured by Kishida Chemical Co., Ltd., special grade) 85.0 parts 66-610-12 Quaternary nylon copolymer resin was dissolved by heating at 65 ° C., and the solution filtered with a polyflon filter (PF020, pore size 2 μm, manufactured by Advantech Toyo Co., Ltd.) was sealed at 23 ° C. for 1 day. Stored in the environment. Subsequently, a gelled polyamide resin 1-20A in which an inflection point was observed in TMA in the penetration measurement using the above-described thermal stress strain measuring apparatus TMA / SS150CU was prepared. Measurement and evaluation were performed in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 21>
Nylon 6-66-610-12 quaternary nylon copolymer resin (trade name: CM8000, manufactured by Toray Industries, Inc.) 10.0 parts 1-butanol (manufactured by Kishida Chemical, special grade) 90.0 parts In the above configuration, Preparation Example 20 A gelled polyamide resin 1-21A was prepared using the same method as above. Measurement and evaluation were performed in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 22>
Nylon 6-66-610-12 quaternary nylon copolymer resin (trade name: CM8000, manufactured by Toray Industries, Inc.) 20.0 parts 1-butanol (manufactured by Kishida Chemical, special grade) 80.0 parts A gelled polyamide resin 1-22A was prepared using the same method as above. Measurement and evaluation were performed in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 23>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, polymerization degree 420, methoxymethylation rate 36.8%) 15.0 parts nylon 6-66-610-12 quaternary Nylon copolymer resin (trade name: CM8000, manufactured by Toray Industries, Inc.) 5.0 parts methanol (made by Kishida Chemical, special grade) 20.0 parts 1-butanol (made by Kishida Chemical, special grade) 60.0 parts Nylon 6-66-610-12 quaternary nylon copolymer resin and N-methoxymethylated 6 nylon resin were dissolved by heating at 50 ° C. in a mixed solvent of butanol. Next, the solution filtered with a polyflon filter (PF020, pore size 2 μm, manufactured by Advantech Toyo Co., Ltd.) was stored in an airtight container at 23 ° C. for 1 day. Subsequently, a gelled polyamide resin 1-23A in which an inflection point was observed in TMA in the penetration measurement using the above-described thermal stress strain measuring apparatus TMA / SS150CU was prepared. Measurement and evaluation were performed in the same manner as in Preparation Example 1. The results are shown in Table 1.

<Preparation Example 24>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, degree of polymerization 420, methoxymethylation rate 36.8%) 7.5 parts methanol (manufactured by Kishida Chemical, special grade) 92. 5 parts In the above configuration, N-methoxymethylated 6 nylon resin was dissolved by heating at 50 ° C., and the solution filtered with a membrane filter (FP-022, pore size 0.22 μm, manufactured by Sumitomo Electric Industries) was sealed in a sealed container. It was stored at 30 ° C. for 30 days. Next, an ungelatinized polyamide resin 2-1A in which an inflection point was not observed in TMA in the penetration measurement using the above-described thermal stress strain measuring apparatus TMA / SS150CU was prepared.

  Further, the liquid color and state of the non-gelled polyamide resin 2-1A were evaluated qualitatively by visual observation. The evaluation result was a “transparent liquid” when the liquid color of the non-gelled polyamide resin was colorless and transparent and fluid. The results are shown in Table 1.

<Preparation Example 25>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, degree of polymerization 420, methoxymethylation rate 36.8%) 2.5 parts ethanol (made by Kishida Chemical, special grade) 97. 5 parts Polyamide resin 2-2A having the above structure and not gelled was prepared using the same method as in Preparation Example 24. Measurement and evaluation were performed in the same manner as in Preparation Example 24. The results are shown in Table 1.

<Preparation Example 26>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, polymerization degree 420, methoxymethylation rate 36.8%) 2.5 parts 1-propanol (made by Kishida Chemical, special grade) 97.5 parts Polyamide resin 2-3A having the above structure and not gelled was prepared using the same method as in Preparation Example 24. Measurement and evaluation were performed in the same manner as in Preparation Example 24. The results are shown in Table 1.

<Preparation Example 27>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, polymerization degree 420, methoxymethylation rate 36.8%) 2.5 parts isopropanol (made by Kishida Chemical, special grade) 97. 5 parts Polyamide resin 2-4A having the above structure and not gelled was prepared using the same method as in Preparation Example 24. Measurement and evaluation were performed in the same manner as in Preparation Example 24. The results are shown in Table 1.

<Preparation Example 28>
Nylon 6-66-610-12 quaternary nylon copolymer resin (trade name: CM8000, manufactured by Toray Industries, Inc.) 2.5 parts 1-butanol (made by Kishida Chemical Co., Ltd., special grade) 97.5 parts In the above configuration, Preparation Example 24 Using the same method as above, a non-gelled polyamide resin 2-5A was prepared. Measurement and evaluation were performed in the same manner as in Preparation Example 24. The results are shown in Table 1.

<Preparation Example 29>
N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation, polymerization degree 420, methoxymethylation rate 36.8%) 4.5 parts nylon 6-66-610-12 quaternary Nylon copolymer resin (trade name: CM8000, manufactured by Toray Industries, Inc.) 1.5 parts Methanol 94.0 parts Polyamide resin 2-6A that has not been gelled was prepared using the same method as in Preparation Example 24. . Measurement and evaluation were performed in the same manner as in Preparation Example 24. The results are shown in Table 1.

  As is apparent from Table 1, in Preparation Example 1-23, an inflection point was observed in TMA in the penetration measurement using the thermal stress strain measuring apparatus TMA / SS150CU, and therefore Preparation Example 1-23 was a gelled polyamide. Resin. In addition, in Preparation Example 24-29, no inflection point is observed in TMA in the penetration measurement using the thermal stress strain measuring apparatus TMA / SS150CU, and thus Preparation Example 24-29 is a polyamide resin that is not gelled. Further, in the qualitative appearance, the gelled polyamide resin has a light white to white color and fluidity is lost, and the non-gelled polyamide resin has a transparent color and fluidity.

  Next, preparation of an electrophotographic photoreceptor coating dispersion using the gelled polyamide resin and the non-gelled polyamide resin prepared above will be described.

<Example 1>
4.6 parts of the gelated polyamide resin 1-1A, methanol (manufactured by Kishida Chemical Co., Ltd.) 1.0 part φ1.0 glass beads 11 parts bisazo pigment 0.023 parts

  With the above configuration, the gelled polyamide resin 1-1A was crushed with a sieve (mesh opening 1.0 mm) and crushed to a size of 1 mm by filtration, and then dispersed for 4 hours using a paint shaker. A dispersion 1-1B having a mass ratio of pigment to polyamide resin of 1: 5 was obtained.

Using a Microtrac UPA particle size distribution measuring device, the volume average particle size (D ₅₀ ) of the dispersion 1-1B was measured. Moreover, the average particle diameter (median diameter) of the dispersion liquid 1-1B was measured using a centrifugal sedimentation type particle size distribution analyzer CAPA-700 (manufactured by Horiba Seisakusho).

  After preparing the dispersion 1-1B, an amount of a liquid surface height of 50 mm is put into a stoppered graduated cylinder (capacity 10 ml), and the dispersion 1-1B is allowed to stand for 1 month and then for 3 months. The liquid stability was visually evaluated. The evaluation results are “no sedimentation” when separation of the bisazo pigment is not recognized, “slightly sedimentation” when separation of the bisazo pigment is recognized at a position of about 1 mm from the liquid level, and from 10 mm from the liquid level. The case where separation of the bisazo pigment was observed at a low position was defined as “completely settled”. The results are shown in Table 2.

<Example 2-23>
Gelled polyamide resin amount (parts) of the gelled polyamide resin corresponding to the examples in Table 2
Solvent amount (parts) of the solvent (manufactured by Kishida Chemical, special grade) corresponding to the examples in Table 2
φ1.0 glass beads 11 parts Amount (parts) of the formula (1) bisazo pigment of the formula (1) bisazo pigment corresponding to the examples in Table 2
With the above configuration, the gelled polyamide resin corresponding to the examples in Table 2 was crushed with a sieve (mesh opening 1.0 mm) and crushed to a size of 1 mm by using a paint shaker. Time dispersed. Then, methanol (parts) of methanol (special grade, manufactured by Kishida Chemical Co., Ltd.) corresponding to the examples in Table 2 was added, and the dispersion corresponding to the examples in Table 2 in which the mass ratio of bisazo pigment to polyamide resin was 1: 5. A liquid was obtained.

Using a Microtrac UPA particle size distribution analyzer, the volume average particle size (D ₅₀ ) of the dispersion corresponding to the examples in Table 2 was measured. Moreover, the average particle diameter (median diameter) of the said dispersion liquid corresponding to the Example of Table 2 was measured using the centrifugal sedimentation type particle size distribution analyzer CAPA-700 (made by Horiba Seisakusho).

  After preparing the said dispersion liquid corresponding to the Example of Table 2, the quantity which makes a liquid level height 50mm is put into a stoppered graduated cylinder (capacity | capacitance 10 ml), Table 2 after leaving still for one month and leaving still for three months The liquid stability of the dispersion corresponding to Example 1 was visually evaluated. The evaluation results are “no sedimentation” when separation of the bisazo pigment is not recognized, “slightly sedimentation” when separation of the bisazo pigment is recognized at a position of about 1 mm from the liquid level, and from 10 mm from the liquid level. The case where separation of the bisazo pigment was observed at a low position was defined as “completely settled”. The results are shown in Table 2.

<Comparative example 1>
Non-gelling polyamide resin 2-1A 3.1 parts 1-butanol (manufactured by Kishida Chemical, special grade) 1.5 parts φ1.0 glass beads 11 parts bisazo pigment 0.047 parts Dispersion was carried out for 4 hours using a paint shaker, and then 3.0 parts of methanol (made by Kishida Chemical Co., Ltd., special grade) was added to obtain dispersion 2-1B having a mass ratio of bisazo pigment to polyamide resin of 1: 5.

  After preparing the dispersion 2-1B, an amount of a liquid surface height of 50 mm is put into a stoppered graduated cylinder (capacity 10 ml), and after standing for 1 month, the dispersion 2-1B is allowed to stand for 3 months. The liquid stability was visually evaluated. The evaluation results are “no sedimentation” when separation of the bisazo pigment is not recognized, “slightly sedimentation” when separation of the bisazo pigment is recognized at a position of about 1 mm from the liquid level, and from 10 mm from the liquid level. The case where separation of the bisazo pigment was observed at a low position was defined as “completely settled”. The results are shown in Table 2.

<Comparative Example 2-5>
The non-gelled polyamide resin species corresponding to the comparative examples in Table 2 and the amount of non-gelled polyamide resin (parts)
Solvent amount (parts) of the solvent type (manufactured by Kishida Chemical, special grade) corresponding to the comparative example in Table
φ1.0 glass beads 11 parts Amount (parts) of the formula (1) bisazo pigment of the formula (1) bisazo pigment corresponding to the comparative example of Table 2
With the above configuration, dispersion was performed for 4 hours using a paint shaker to obtain a dispersion corresponding to the comparative example of Table 2 in which the mass ratio of the bisazo pigment to the polyamide resin was 1: 5.

  After preparing the said dispersion corresponding to the comparative example of Table 2, the quantity which makes a liquid level height 50mm is put into a stoppered measuring cylinder (capacity | capacitance 10ml), Table 2 after leaving still for one month and leaving still for three months The liquid stability of the dispersion liquid corresponding to the comparative example was visually evaluated. The evaluation results are “no sedimentation” when separation of the bisazo pigment is not recognized, “slightly sedimentation” when separation of the bisazo pigment is recognized at a position of about 1 mm from the liquid level, and from 10 mm from the liquid level. The case where separation of the bisazo pigment was observed at a low position was defined as “completely settled”. The results are shown in Table 2.

<Comparative Example 6>
Non-gelling polyamide resin 2-6A 3.8 parts 1-butanol (manufactured by Kishida Chemical Co., Ltd., special grade) 0.8 parts φ1.0 glass beads 11 parts Formula (1) bisazo pigment 0.046 parts Dispersion was carried out for 4 hours using a paint shaker, and then 3.0 parts of methanol (manufactured by Kishida Chemical Co., Ltd., special grade) was added to obtain a dispersion 2-6B having a mass ratio of bisazo pigment to polyamide resin of 1: 5.

  After the dispersion 2-6B was prepared, the amount of the liquid surface height of 50 mm was put into a stoppered graduated cylinder (capacity 10 ml), and the dispersion 2-6B after standing for 3 months was allowed to stand. The liquid stability was visually evaluated. The evaluation results are “no sedimentation” when separation of the bisazo pigment is not recognized, “slightly sedimentation” when separation of the bisazo pigment is recognized at a position of about 1 mm from the liquid level, and from 10 mm from the liquid level. The case where separation of the bisazo pigment was observed at a low position was defined as “completely settled”. The results are shown in Table 2.

From Table 2, the following is clear. In Example 1-23, the formula (1) bisazo pigment and the gelled polyamide resin are dispersed in a solvent. Therefore, in Example 1-23, the volume average particle diameter (D ₅₀ ) of Microtrac UPA and the average particle diameter (median diameter) of CAPA-700 in the dispersion are extremely small as compared with Comparative Example 1-6. Moreover, almost no sedimentation is observed even in the liquid state after standing for 1 month and after standing for 3 months. From this, it can be seen that Example 1-23 in which the organic pigment and the gelled polyamide resin are dispersed in the solvent has very high liquid stability.

  The preparation of a dispersion using the gelled polyamide resin or the non-gelled polyamide resin prepared above and shaking the mass ratio of the bisazo pigment and the polyamide resin in the range of 2: 1 to 1: 1000 will be described.

<Example 24-29>
4.6 parts methanol (made by Kishida Chemical, special grade) 2.3 parts ethanol (made by Kishida Chemical, special grade) 2.3 parts φ1.0 glass beads 11 parts Examples of Table 3 The amount of the bisazo pigment of the formula (1) corresponding to the above composition was dispersed for 4 hours using a paint shaker. Next, after adding an ethanol amount (part) of ethanol corresponding to the examples in Table 3 (made by Kishida Chemical Co., Ltd., special grade), it was filtered through a polyflon filter (PF020, pore size 2 μm, manufactured by Advantech Toyo Co., Ltd.). A dispersion corresponding to the Example was obtained.

Using a Microtrac UPA particle size distribution measuring device, the volume average particle size (D ₅₀ ) of the dispersion corresponding to the examples in Table 3 was measured. Moreover, the average particle diameter (median diameter) of the dispersion liquid corresponding to the Example of the said Table 3 was measured using the centrifugal sedimentation type particle size distribution measuring apparatus CAPA-700 (made by Horiba Seisakusho).

  After preparing the dispersion corresponding to the examples in Table 3, the amount of the liquid surface height of 50 mm was put into a stoppered graduated cylinder (capacity 10 ml), left for 1 month, then left for 3 months. The liquid stability of the dispersion liquid corresponding to Example 3 was visually evaluated. The evaluation results were defined as “no sedimentation” when the separation of the bisazo pigment was not observed, and “slightly sedimentation” when the separation of the bisazo pigment was observed at a position about 1 mm from the liquid level. The results are shown in Table 3.

<Example 30>
4.6 parts of the gelled polyamide resin liquid 1-4A methanol (made by Kishida Chemical, special grade) 2.3 parts ethanol (made by Kishida Chemical, special grade) 2.3 parts φ1.0 glass beads 11 parts the formula (1) Bisazo pigment 0.0005 part The composition described above was dispersed for 4 hours using a paint shaker. Next, 2.3 parts of ethanol (manufactured by Kishida Chemical Co., Ltd., special grade) was added to obtain a dispersion 3-7B.

The volume average particle size (D ₅₀ ) of the dispersion 3-7B was measured using a Microtrac UPA particle size distribution analyzer. Moreover, the average particle diameter (median diameter) of the dispersion 3-7B was measured using a centrifugal sedimentation type particle size distribution analyzer CAPA-700 (manufactured by Horiba Seisakusho).

  After the dispersion 3-7B was prepared, an amount of a liquid level of 50 mm was put into a stoppered graduated cylinder (capacity 10 ml), and the dispersion 3-7B after standing for 3 months was allowed to stand. The liquid stability was visually evaluated. The evaluation result was “no sedimentation” when no separation of the bisazo pigment was observed. The results are shown in Table 3.

<Comparative Example 7>
Non-gelling polyamide resin liquid 2-2A 4.6 parts methanol (manufactured by Kishida Chemical, special grade) 2.3 parts ethanol (manufactured by Kishida Chemical, special grade) 2.3 parts φ1.0 glass beads 11 parts said formula (1 ) Bisazo pigment 0.0005 parts In the above-described configuration, dispersion was performed for 4 hours using a paint shaker, and then 2.3 parts of ethanol (made by Kishida Chemical Co., Ltd., special grade) was added to obtain dispersion 4-1B.

The volume average particle size (D ₅₀ ) of the dispersion 4-1B was measured using a Microtrac UPA particle size distribution analyzer. Moreover, the average particle diameter (median diameter) of the dispersion 4-1B was measured using a centrifugal sedimentation type particle size distribution analyzer CAPA-700 (manufactured by Horiba Seisakusho).

  After preparing the dispersion liquid 4-1B, an amount of a liquid level height of 50 mm is put into a stoppered graduated cylinder (capacity 10 ml), and after standing for 1 month, the dispersion liquid 4-1B after standing for 3 months The liquid stability of the dispersion was visually evaluated. The evaluation result was defined as “completely settled” when separation of the bisazo pigment was observed at a position lower than 10 mm from the liquid surface height. The results are shown in Table 3.

Table 3 shows the results of dispersion by changing the mass ratio of the bisazo pigment and the polyamide resin in the dispersion within a range of 2: 1 or less and 1: 1000 or more. In Examples 24-30, the formula (1) bisazo pigment and the gelled polyamide resin were dispersed in a solvent. For this reason, in Examples 24-30, the volume average particle diameter (D ₅₀ ) of the microtrack UPA of the dispersion and the average of CAPA-700 in the mass ratio of bisazo pigment and polyamide resin in the range of 2: 1 to 1: 1000 The particle size (median diameter) is extremely small as compared with Comparative Example 7. Moreover, almost no sedimentation is observed even in the liquid state after standing for 1 month and after standing for 3 months. From this, it can be seen that Examples 24-30 in which an organic pigment and a gelled polyamide resin are dispersed in a solvent have very high liquid stability. In particular, in Examples 25-30, no precipitation of the bisazo pigment was observed even after standing for 3 months.

  The preparation of a dispersion using the polyamide resin prepared above and changing the type of organic pigment will be described.

<Example 31>
Gelated polyamide resin 1-4A 50.0 parts Methanol (manufactured by Kishida Chemical, special grade) 25.0 parts Ethanol (manufactured by Kishida Chemical, special grade) 25.0 parts φ1.0 glass beads 240 parts Bisazo 1.0 part of pigment

  In the above configuration, dispersion was performed for 4 hours using a paint shaker, and then an ethanol amount (part) of ethanol (special grade, manufactured by Kishida Chemical Co., Ltd.) corresponding to the examples in Table 4 was added, and the mass ratio of the bisazo pigment to the polyamide resin was 1. : Dispersion 6-1B was obtained.

The volume average particle diameter (D ₅₀ ) of the dispersion 6-1B was measured using a Microtrac UPA particle size distribution analyzer. Moreover, the average particle diameter (median diameter) of the dispersion liquid 6-1B was measured using a centrifugal sedimentation type particle size distribution analyzer CAPA-700 (manufactured by Horiba, Ltd.).

  After preparing the dispersion liquid 6-1B, an amount of the liquid surface height of 50 mm is put into a stoppered graduated cylinder (capacity 10 ml), and after standing for 1 month, the dispersion liquid 6-1B is allowed to stand for 3 months. The liquid stability was visually evaluated. The evaluation results were “no sedimentation” when no separation of the pigment was observed, and “slightly sedimentation” when separation of the bisazo pigment was observed at a position about 1 mm from the liquid level. Further, a sample in which separation of the bisazo pigment was observed at a position of about 3 mm from the liquid surface height was defined as “slightly settled”. The results are shown in Table 4.

<Example 32>
A dispersion 6-2B was prepared in the same manner as in Example 31 except that the bisazo pigment in Example 31 was changed from the formula (2) to the bisazo pigment of the following formula (3). Measurement and evaluation were performed in the same manner. The results are shown in Table 4.

<Example 33>
A dispersion 6-3B was prepared in the same manner as in Example 31 except that the bisazo pigment in Example 31 was changed from the formula (2) to the bisazo pigment of the following formula (4). Measurement and evaluation were performed in the same manner. The results are shown in Table 4.

<Example 34>
A dispersion 6-4B was prepared in the same manner as in Example 31 except that the bisazo pigment in Example 31 was changed from the formula (2) to the bisazo pigment of the following formula (5). Measurement and evaluation were performed in the same manner. The results are shown in Table 4.

<Example 35>
A dispersion 6-5B was prepared in the same manner as in Example 31 except that the bisazo pigment of the formula (2) in Example 31 was replaced with the following gallium phthalocyanine pigment, and measured in the same manner as in Example 31. And evaluated. Gallium phthalocyanine crystal having strong peaks at positions of flag angles 2θ = 7.4 ° ± 0.3 ° and 2θ = 28.2 ° ± 0.3 ° in CuKα characteristic X-ray diffraction of the following formula (6) (patent no. Described in Japanese Patent No. 3639691). The results are shown in Table 4.

<Example 36>
A dispersion 6-6B was prepared in the same manner as in Example 31 except that the bisazo pigment of the formula (2) was replaced with the bisazo pigment of the following formula (7) in Example 31. Measurement and evaluation were performed in the same manner. The results are shown in Table 4.

<Example 37>
Polyamide resin liquid 1-6A 50.0 parts Methanol (manufactured by Kishida Chemical, special grade) 25.0 parts Ethanol (manufactured by Kishida Chemical, special grade) 25.0 parts φ1.0 glass beads 240 parts Bisazo pigment of the above formula (7) 0. 075 parts In the above configuration, dispersed for 4 hours using a paint shaker, and then added ethanol amount (parts) of ethanol (special grade, manufactured by Kishida Chemical Co., Ltd.) corresponding to the examples in Table 4, and the mass ratio of bisazo pigment to polyamide resin A dispersion 6-7B having a ratio of 1: 100 was obtained. Measurement and evaluation were performed in the same manner as in Example 31. The results are shown in Table 4.

<Example 38>
The mass of the bisazo pigment and the polyamide resin in the same manner as in Example 37, except that 0.075 part of the formula (7) bisazo pigment is replaced with 0.0075 part of the formula (7) bisazo pigment in Example 37. Dispersion 6-8B having a ratio of 1: 1000 was prepared. Next, measurement and evaluation were performed in the same manner as in Example 31. The results are shown in Table 4.

<Example 39>
φ1.0 glass beads 240 parts Methanol (manufactured by Kishida Chemical, special grade) 25.0 parts ethanol (manufactured by Kishida Chemical, special grade) 25.0 parts formula (7) Bisazo pigment 1.0 part After time dispersion, 50.0 parts of polyamide resin solution 1-4A was added and further dispersed for 2 hours. Next, an ethanol amount (part) of ethanol (made by Kishida Chemical Co., Ltd., special grade) corresponding to the examples in Table 4 was added to prepare a dispersion 6-9B having a mass ratio of bisazo pigment and polyamide resin of 1: 5, Measurement and evaluation were performed in the same manner as in Example 31. The results are shown in Table 4.

<Example 40>
Gelatinized polyamide resin 1-4A 250.0 parts Methanol (manufactured by Kishida Chemical, special grade) 125.0 parts Ethanol (manufactured by Kishida Chemical, special grade) 125.0 parts 5.0 parts of the above formula (7) bisazo pigment Then, using a commercially available stirrer (Three-One Motor BL600, manufactured by Shinto Kagaku Co., Ltd.) and a propeller-type stirring blade, the pigment and the polyamide resin in the solvent were stirred for 30 minutes. Next, circulation dispersion was performed at 1000 rpm for 4 hours using φ1.0 glass beads (filling rate 85%) with a horizontal disperser DISPERMAT SL-C25 (manufactured by VMA). Next, an ethanol amount (part) of ethanol (special grade, manufactured by Kishida Chemical Co., Ltd.) corresponding to the examples in Table 4 was added to obtain a dispersion 6-10B having a mass ratio of bisazo pigment and polyamide resin of 1: 5. Measurement and evaluation were performed in the same manner as in Example 31. The results are shown in Table 4.

<Comparative Example 8>
Non-gelling polyamide resin 2-2A 50.0 parts Methanol (manufactured by Kishida Chemical, special grade) 25.0 parts Ethanol (manufactured by Kishida Chemical, special grade) 25.0 parts φ1.0 glass beads 240 parts The formula (2) Bisazo pigment 0.75 parts In the above configuration, dispersed for 4 hours using a paint shaker, and then added an ethanol amount (part) of ethanol (special grade, manufactured by Kishida Chemical Co., Ltd.) corresponding to the comparative example in Table 4 to add a bisazo pigment and polyamide A dispersion 7-1B having a resin mass ratio of 1: 5 was obtained.

The volume average particle diameter (D ₅₀ ) of the dispersion 7-1B was measured using a Microtrac UPA particle size distribution analyzer. Moreover, the average particle diameter (median diameter) of the dispersion liquid 7-1B was measured using a centrifugal sedimentation type particle size distribution analyzer CAPA-700 (manufactured by Horiba, Ltd.).

  After preparing the dispersion liquid 7-1B, an amount of the liquid surface height of 50 mm is put into a stoppered graduated cylinder (capacity 10 ml), and after standing for 1 month, the dispersion liquid 7-1B is allowed to stand for 3 months. The liquid stability was visually evaluated. The evaluation result was defined as “completely settled” when separation of the bisazo pigment was observed at a position lower than 10 mm from the liquid surface height. The results are shown in Table 4.

<Comparative Example 9>
A dispersion 7-2B was prepared in the same manner as in Comparative Example 8 except that the bisazo pigment was replaced with the bisazo pigment of Formula (5) from Formula (2) in Comparative Example 8, and Comparative Example 8 and Measurement and evaluation were performed in the same manner. The results are shown in Table 4.

<Comparative Example 10>
Dispersion 7-3B was prepared in the same manner as in Comparative Example 8, except that the bisazo pigment of formula (2) was replaced by the gallium phthalocyanine pigment of formula (6) from formula (2) in comparative example 8. Prepared and measured and evaluated in the same manner as in Comparative Example 8. The results are shown in Table 4.

<Comparative Example 11>
Dispersion 7-4B was prepared in the same manner as in Comparative Example 8, except that the bisazo pigment of formula (2) was replaced with the bisazo pigment of formula (7) in Comparative Example 8, and Comparative Example 8 and Measurement and evaluation were performed in the same manner. The results are shown in Table 4.

<Comparative example 12>
A dispersion 7-5B was prepared in the same manner as in Comparative Example 8, except that 0.75 part of the bisazo pigment of formula (2) was replaced with 0.038 part of the bisazo pigment of formula (7) in Comparative Example 8. Was prepared and measured and evaluated in the same manner as in Comparative Example 8. The results are shown in Table 4.

<Comparative Example 13>
A dispersion 7-6B was prepared in the same manner as in Comparative Example 8, except that 0.75 part of the bisazo pigment of formula (2) was replaced with 0.0038 part of the bisazo pigment of formula (7) in Comparative Example 8. Was prepared and measured and evaluated in the same manner as in Comparative Example 8. The results are shown in Table 4.

<Comparative example 14>
φ1.0 glass beads 240 parts methanol (made by Kishida Chemical, special grade) 25.0 parts ethanol (made by Kishida Chemical, special grade) 25.0 parts formula (7) bisazo pigment 0.75 parts After time dispersion, 50.0 parts of the non-gelled polyamide resin liquid 2-2A was added and further dispersed for 2 hours. Next, an ethanol amount (part) of ethanol (made by Kishida Chemical Co., Ltd., special grade) corresponding to the comparative example of Table 4 was added to prepare a dispersion 7-7B having a mass ratio of bisazo pigment and polyamide resin of 1: 5, Measurement and evaluation were performed in the same manner as in Comparative Example 8. The results are shown in Table 4.

<Comparative Example 15>
Non-gelling polyamide resin 2-1A 250.0 parts Methanol (manufactured by Kishida Chemical, special grade) 125.0 parts Ethanol (manufactured by Kishida Chemical, special grade) 125.0 parts Bisazo pigment of the above formula (7) 3.8 parts With the configuration, the pigment in the solvent and the polyamide resin were stirred for 30 minutes using a commercially available stirrer (Three-One Motor BL600, manufactured by Shinto Kagaku Co., Ltd.) and a propeller-type stirring blade. Next, circulation dispersion was performed at 1000 rpm for 4 hours using φ1.0 glass beads (filling rate 85%) with a horizontal disperser DISPERMAT SL-C25 (manufactured by VMA). Next, an ethanol amount (part) of ethanol (special grade, manufactured by Kishida Chemical Co., Ltd.) corresponding to the comparative example in Table 4 was added to obtain a dispersion 7-8B having a mass ratio of bisazo pigment to polyamide resin of 1: 5. Measurement and evaluation were performed in the same manner as in Comparative Example 8. The results are shown in Table 4.

From Table 4, the following is clear. In Examples 31-40, the type of organic pigment and the mass ratio of the pigment to the polyamide resin were changed, and the organic pigment and the gelled polyamide resin were dispersed in the solvent. Therefore, in Examples 31-40, the volume average particle diameter (D ₅₀ ) of the microtrack UPA and the average particle diameter of CAPA-700 ( The median diameter) is extremely small compared to Comparative Example 8-15. Moreover, almost no sedimentation is observed even in the liquid state after standing for 1 month and after standing for 3 months. From this, it can be seen that Examples 31-40 in which the organic pigment and the gelled polyamide resin are dispersed in the solvent have very high liquid stability.

  Subsequently, using the dispersion liquid obtained above, the coating film of the dispersion liquid was evaluated.

<Examples 41-47 and Comparative Examples 16-21>
Dispersions corresponding to the examples and comparative examples in Table 5 were applied on a PET film with a Meyer bar so as to have a film thickness of 2 μm, and dried at 100 ° C. for 20 minutes. A dispersion coating film corresponding to the example was obtained. Subsequently, the qualitative appearance of the sheet surface of the dispersion coating film corresponding to the examples and comparative examples in Table 5 was evaluated. The evaluation results were defined as “film fogging” when the film was visually cloudy (whitening), and “no film fogging” when the film was not cloudy (whitening). In addition, the gloss of the dispersion coating film corresponding to the examples and comparative examples in Table 5 (PG-1M, manufactured by Nippon Denshoku Industries Co., Ltd., Canon's color laser copier paper having a measurement angle of 60 ° and a whiteness of 92%. And 10-point average roughness Rzjis (Surfcoder SE-3500, manufactured by Kosaka Laboratory Ltd.). The results are shown in Table 5.

  From Table 5, the following is clear. The dispersion coating film 1-7 using a dispersion in which the kind of organic pigment and the mass ratio of the pigment and the polyamide resin are changed and the organic pigment and the gelled polyamide resin are dispersed in a solvent is a dispersion coating film 8- Compared to 13, the film has no film haze in the qualitative appearance, exhibits a very high gloss and a small ten-point average roughness. From this, a dispersion coating film using a dispersion liquid in which an organic pigment and a gelled polyamide resin are dispersed in a solvent has a high glossiness, and a smooth coating film with no qualitative appearance and no film haze is obtained. I can see that

  Next, an electrophotographic photoreceptor was prepared using the dispersion obtained above.

<Example 48>
Titanium oxide powder coated with tin oxide (trade name Kronos ECT-62, manufactured by Titanium Industry Co., Ltd.) 50 parts resol type phenol resin 25 parts methyl cellosolve 20 parts spherical silicone resin powder (trade name Tospearl 120, manufactured by Toshiba Silicone) 3 .8 parts methanol 5 parts silicone oil (polydimethylsiloxane / polyoxyalkylene copolymer, average molecular weight 3000) 0.002 parts In the above configuration, dispersed for 2 hours in a sand mill using 0.8 mm diameter glass beads Then, a coating solution for interference fringe prevention layer was prepared. This coating solution was dip-coated on an aluminum cylinder (diameter 30 mm, drawn tube) as a conductive support and dried at 140 ° C. for 30 minutes to form an interference fringe preventing layer having a thickness of 15 μm.

  On the obtained interference fringe prevention layer, the dispersion 6-1B prepared one day ago was dip coated and dried at 100 ° C. for 10 minutes to form an undercoat layer having a thickness of 0.5 μm.

  Next, 10 parts of the following hydroxygallium phthalocyanine, 0.1 part of the compound represented by the following formula (8) and 5 parts of the following polyvinyl butyral resin were added to 250 parts of cyclohexanone, and glass beads having a diameter of 0.8 mm were used. Dispersed for 3 hours in a sand mill. Strong at Bragg angles (2θ ± 0.2 °) of 7.5 °, 9.9 °, 16.3 °, 18.6 °, 25.1 ° and 28.3 ° in CuKα characteristic X-ray diffraction Crystalline hydroxygallium phthalocyanine having a peak. Polyvinyl butyral resin (trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.). To this, 100 parts of cyclohexanone and 450 parts of ethyl acetate were further added and diluted to obtain a coating solution for charge generation layer. The obtained coating solution was dip-coated on the undercoat layer and dried at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.16 μm.

  Next, 10 parts of a charge transport material represented by the following formula (9) and 10 parts of a polycarbonate resin (trade name: Iupilon Z-200, manufactured by Mitsubishi Engineering Plastics) were dissolved in 70 parts of monochlorobenzene. The obtained solution was dip-coated on the charge generation layer and dried at 110 ° C. for 1 hour to form a charge transport layer having a thickness of 25 μm, and thus the electrophotographic photoreceptor 1 was produced.

  The presence or absence of coating defects on the electrophotographic photoreceptor 1 was visually evaluated by visual observation. The evaluation results were defined as “no spots” when no spots were found on the drum coating surface, and “some spots” when spots were found on part of the drum coating surface. In addition, a sample in which a spot was found on the entire coated surface of the drum was designated as “full spot”. The results are shown in Table 6.

  Next, with respect to the produced electrophotographic photoreceptors 1-8 and 15, a bright part potential measurement was performed.

  A drum testing machine manufactured by Gentec Co., Ltd .: CYNTHIA59 was used as an evaluation machine. A scorotron corona charger was used for charging the surface of the electrophotographic photosensitive member. The primary current was set to 70 μA, and the grid voltage was set so that the applied voltage on the surface of the electrophotographic photosensitive member was −700V. A xenon lamp was used as the image exposure light source. The exposure light wavelength was selected using a 780 nm interference filter, and the amount of light was adjusted so that the bright part potential was -200V. A halogen lamp was used as a pre-exposure light source. The pre-exposure light wavelength was selected using a 676 nm interference filter, and the light amount was adjusted to 5 times the image exposure light amount. The cycle speed was 1 sec / cycle. The electrophotographic photosensitive member 1 was attached to this and evaluated. The position of the electric potential measurement probe with respect to the electrophotographic photosensitive member was approximately the center in the axial direction of the electrophotographic photosensitive member, and the gap from the surface of the electrophotographic photosensitive member was 3 mm.

  The electrophotographic photosensitive member 1 is allowed to stand for 3 days in a normal temperature and low humidity (N / L) environment of 23 ° C./5% RH, and then 500 continuous durable prints (full black image mode) under the same environment (N / L). ) And the bright part potential after the durable printing was measured. ΔVD, ΔVL, and ΔVR indicate the amount of change in the post-endurance potential (−V) from the initial potential (−V) of the applied voltage, the bright portion potential, and the residual potential (for example, the initial VD potential is −700 V, and the post-endurance VD When the potential is −695 V, the fluctuation amount ΔVD is expressed as −5 V). The results are shown in Table 6.

<Examples 49-55 and Comparative Examples 22-28>
Using the dispersion or polyamide resin solution corresponding to the examples and comparative examples in Table 5, an electrophotographic photoreceptor 2-15 was prepared in the same manner as in Example 48, and evaluated in the same manner as in Example 48. went.

  From Table 6 it is clear that: Examples 48-55 are electrophotographic photoreceptors using a dispersion obtained by dispersing an organic pigment and a gelled polyamide resin in a solvent. Examples 48-55 were coated in the visual evaluation of the electrophotographic photoreceptor in comparison with Comparative Examples 22-27 of the electrophotographic photoreceptor using a dispersion obtained by dispersing an organic pigment and a non-gelled polyamide resin. It can be seen that there are no defects.

  Further, as apparent from Table 6, in Comparative Example 28 of the electrophotographic photosensitive member using the polyamide resin in which the organic pigment is not dispersed, no coating defect is recognized in the result of visual confirmation of the electrophotographic photosensitive member. However, Examples 48-55 of the electrophotographic photoreceptor using the dispersion obtained by dispersing the gelled polyamide resin and the organic pigment are comparative examples of the electrophotographic photoreceptor using the polyamide resin in which the organic pigment is not dispersed. It can be seen that the potential fluctuation amounts of ΔVL and ΔVR in the N / L environment are very small as compared with 28.

It is a figure which shows the structure of a photosensitive layer. 1 is a diagram illustrating an example of a schematic configuration of an electrophotographic apparatus including a process cartridge having the electrophotographic photosensitive member of the present invention. It is a figure which shows an example of the graph which shows the relationship of LOAD, TMA, and DTMA in the penetration measurement of the gelatinized polyamide resin. The horizontal axis is LOAD, the solid line is TMA, and the broken line is DTMA. It is a figure which shows an example of the graph which shows the relationship of LOAD, TMA, and DTMA in the penetration measurement of the polyamide resin which is not gelatinized. The horizontal axis is LOAD, the solid line is TMA, and the broken line is DTMA.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Support body 102 Undercoat layer 103 Photosensitive layer 104 Charge generation layer 105 Charge transport layer 1 Electrophotographic photosensitive member 2 Axis 3 Charging means 4 Exposure light 5 Developing means 6 Transfer means 7 Transfer material 8 Fixing means 9 Cleaning means 10 Pre-exposure light 11 Process cartridge 12 Guide means

Claims (28)

  A method for producing a dispersion, comprising preparing a dispersion by dispersing an organic pigment and a gelled polyamide resin in a solvent.   2. The method for producing a dispersion according to claim 1, wherein the gelled polyamide resin contains at least N-methoxymethylated nylon or nylon 6-66-610-12 quaternary nylon copolymer. .   The method for producing a dispersion according to claim 1 or 2, wherein the gelled polyamide resin is made into a gelled state using an alcohol solvent.   The method for producing a dispersion according to any one of claims 1 to 3, wherein the gelled polyamide resin is obtained by heating and dissolving the polyamide resin in an alcohol solvent and then cooling.   The method for producing a dispersion according to claim 3 or 4, wherein the alcohol solvent is a linear or branched alcohol having at least 1 to 6 carbon atoms.   The dispersion according to claim 3, wherein the alcohol solvent contains at least one of methanol, ethanol, isopropanol, 1-propanol, 1-butanol, 2-butanol, and isobutanol. Liquid manufacturing method.   The gelled polyamide resin contains the N-methoxymethylated nylon and at least one of methanol, ethanol, isopropanol, 1-propanol, 1-butanol, 2-butanol and isobutanol. The manufacturing method of the dispersion liquid in any one of 1-6.   The method for producing a dispersion according to any one of claims 1 to 7, wherein the gelled polyamide resin contains N-methoxymethylated nylon and 1-butanol.   9. The dispersion according to claim 1, wherein the solid content of the polyamide resin contained in the gelled polyamide resin is in a range of 5.0% to 30.0% by mass%. Manufacturing method.   The dispersion liquid according to any one of claims 1 to 9, wherein the solvent contains at least one of methanol, ethanol, isopropanol, 1-propanol, 1-butanol, 2-butanol and isobutanol. Production method. In a method for producing a dispersion obtained by dispersing an organic pigment and a polyamide resin in a solvent,
A. Preparing a gelled polyamide resin using an alcohol solvent and a polyamide resin;
B. Next, the gelled polyamide resin is crushed to a size of 0.5 mm to 10 mm;
C. Next, the organic pigment and the gelled polyamide resin are dispersed;
The method for producing a dispersion according to claim 1, further comprising a step. In a method for producing a dispersion obtained by dispersing an organic pigment and a polyamide resin in a solvent,
A. Preparing a gelled polyamide resin using an alcohol solvent and a polyamide resin;
C. And then dispersing the organic pigment and the gelled polyamide resin;
D. The resulting dispersion is then filtered and diluted by adding a solvent;
The method for producing a dispersion according to claim 1, further comprising a step. In a method for producing a dispersion obtained by dispersing an organic pigment and a polyamide resin in a solvent,
A. Preparing a gelled polyamide resin using an alcohol solvent and a polyamide resin;
B. Next, the gelled polyamide resin is crushed to a size of 0.5 mm to 10 mm;
C. And then dispersing the organic pigment and the gelled polyamide resin;
D. The resulting dispersion is then filtered and diluted by adding a solvent;
The method for producing a dispersion according to claim 1, further comprising a step.   The method for producing a dispersion according to claim 1, wherein the organic pigment is a phthalocyanine pigment or an azo pigment.   The phthalocyanine pigment is a hydroxygallium phthalocyanine crystal having strong peaks at positions of Bragg angles 2θ = 7.4 ° ± 0.3 ° and 2θ = 28.2 ° ± 0.3 ° in CuKα characteristic X-ray diffraction. The method for producing a dispersion according to claim 14. The method for producing a dispersion according to claim 14, wherein the azo pigment is a bisazo pigment represented by the following general formula (1).
General formula (1)
Cp-N = N-Ar-N = N-Cp
(In the formula, Cp represents a phenolic coupler, and Ar represents an aromatic hydrocarbon ring or an aromatic heterocycle having or not having a substituent, which is bonded via a linking group or bonded via a linking group. To express.) The said bisazo pigment is represented by following General formula (2), The manufacturing method of the dispersion liquid of Claim 16 characterized by the above-mentioned.
The said bisazo pigment is represented by following General formula (3), The manufacturing method of the dispersion liquid of Claim 16 characterized by the above-mentioned.

(In general formula (3), Ar represents any group of the following general formula (4), formula (5), or formula (6)).



(In General Formula (3), R ₁ and R ₂ each independently represent a hydrogen atom, an aryl group which may have a substituent, or a carbamoyl group which may have a substituent, provided that R ₁ and R ₂ is not simultaneously a hydrogen atom, X represents O or S. Y is condensed with a benzene ring to form an optionally substituted aromatic hydrocarbon ring or aromatic heterocyclic ring. In general formula (4), R ₃ , R ₄ , R ₅ , R ₆ and R ₇ may each independently have a hydrogen atom, a halogen atom or a substituent. A good alkyl group, an aralkyl group which may have a substituent or an aryl group which may have a substituent, A represents O, S or N—R ₈ , where R ₈ is a hydrogen atom, a substituent An alkyl group optionally having a group, an aralkyl optionally having a substituent Or an aryl group which may have a substituent.)   The method for producing a dispersion according to claim 1, wherein a mass ratio of the organic pigment to the polyamide resin is from 1: 1000 to 2: 1.   The method for producing a dispersion according to claim 19, wherein the mass ratio is 1: 100 or more and 1: 1 or less.   A dispersion obtained by the method for producing a dispersion according to claim 1.   21. A dispersion for coating an electrophotographic photosensitive member obtained by the method for producing a dispersion according to claim 1.   An electrophotographic photosensitive member having at least a conductive support and a photosensitive layer, wherein the electrophotographic photosensitive member coating dispersion according to claim 22 is formed between the conductive support and the photosensitive layer. An electrophotographic photosensitive member comprising:   24. The electrophotographic photosensitive member according to claim 23, wherein the photosensitive layer contains a phthalocyanine pigment.   The electrophotographic photosensitive member according to claim 24, wherein the phthalocyanine pigment is a gallium phthalocyanine pigment.   The gallium phthalocyanine pigment is a hydroxygallium phthalocyanine crystal having strong peaks at Bragg angles 2θ = 7.4 ° ± 0.3 ° and 2θ = 28.2 ° ± 0.3 ° in CuKα characteristic X-ray diffraction. 26. The electrophotographic photosensitive member according to claim 25.   27. An electrophotographic apparatus comprising: the electrophotographic photosensitive member according to claim 23; and a charging unit, an image exposure unit, a developing unit, and a transfer unit.   An electrophotographic photosensitive member according to any one of claims 23 to 26 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 detachably attached to an electrophotographic apparatus main body. Process cartridge characterized by being.