JP2002040680A - Image-forming method and image-forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image-forming method and an image-forming device by which an image high in gradation and resolution can be obtained, even under a fast process. SOLUTION: In the image-forming method, a photoreceptor, having following photosensitive layer is subjected to digital image exposure, and a toner having 3 to 8 μm volume average particles size (DV) is used for the development of the electrostatic latent image formed by this image exposure. The photosensitive layer consists of laminated layers of a charge-generating layer containing at least oxytitanium phthalocyanine, showing a clear diffraction peak at 27.3 deg., with the for the Bragg angle (2θ±0.2) in X-ray diffraction for the CuKα line and a charge transfer layer containing polyester resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming method and an image forming apparatus. More specifically, the present invention relates to an image forming method and an image forming apparatus that can be suitably used for a printer and an electrophotographic copying machine.

[0002]

2. Description of the Related Art With the rapid spread of copiers and printers using electrophotography, the demand for high-definition images has increased in recent years. It has become essential to respond to a long life of the photoconductor. Among them, it is conceivable to increase the number of dots at the time of image exposure in order to improve a high-definition image, in particular, gradation and resolution. For this purpose, the beam diameter is reduced and the number of output pulses is increased. However, in such high-density recording, the time required for exposing one dot is reduced. In such a case, depending on the photoreceptor, the sensitivity is insufficient and the reproducibility of one dot is deteriorated, so that the gradation and the resolving power are not improved. In order to solve this problem, it is conceivable to increase the light energy itself, but this causes a problem such as light fatigue in the photosensitive layer.

In order to improve the reproducibility of one dot even in high-density recording, Japanese Patent Laid-Open Publication No.
Crystalline oxytitanyl phthalocyanine showing a strong X-ray intensity peak at a Bragg angle 2θ of 27.2 ± 0.2 ° in an X-ray diffraction spectrum with respect to CuKα characteristic X-rays (wavelength 1.541 °) is irradiated with light of a photosensitive layer. A method used as a conductive substance is disclosed. By using this oxytitanyl phthalocyanine, it is possible to realize a photoreceptor exhibiting sufficient photoresponsiveness with high sensitivity, and when using this photoreceptor,
It is shown that sufficient dot reproducibility can be realized even when the exposure time of each dot is short in high density recording.

In developing the latent image on the photoreceptor, a known toner can be used. However, in order to faithfully reproduce a latent image formed in a state where minute dots are collected, a small amount of toner is used. It is effective to reduce the diameter, and the reduction of the particle diameter of the toner has been promoted so far. However, even in the case of a small particle size toner, a polymer is mixed with a colorant, a charge control agent, and the like, then melt-kneaded, and then extruded, pulverized, and classified. In the case of the toner, the adhesion on the latent image is not uniform due to the variation in shape, and therefore, there is a limit in faithfully reproducing the latent image. In addition, the toner having a small particle diameter has a greater adhesion force (mirror image force, van der Waals force, etc.) of the toner particles to the photoreceptor than the Coulomb force applied to the toner particles during transfer, and as a result, the transfer residual toner is reduced. There was a tendency to increase.

Therefore, it is necessary to improve the releasability of the photoreceptor. However, the polycarbonate resin which has been conventionally used for most photoreceptors, including the photoreceptor described in JP-A-3-37678, has a problem in terms of releasability. Not always enough,
There has been a need for the use of a resin having good releasability. Further, to meet the demand for longer life of the photoconductor, it is necessary to improve the wear resistance of the photoconductor. But,
Polycarbonate resins do not always have sufficient abrasion resistance, and may hinder long life. As described above, in order to simultaneously achieve high image quality and high-definition images while responding to the recent increase in the speed of the electrophotographic process and the long life of the photoconductor, the current photoconductor and development system Further improvements have been sought.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the prior art.
That is, an object of the present invention is to provide an image forming method and an image forming apparatus which can obtain an image having excellent fine line reproducibility and gradation, and which has a long life and is suitable for a high-speed process.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above problems, and as a result, have found that the above problems can be solved by a specific combination of a photosensitive member, an exposure device, and a toner, and have reached the present invention. That is, the gist of the present invention is that at least the Bragg angle (2
(θ ± 0.2) a charge generation layer containing oxytitanium phthalocyanine showing a clear diffraction peak at 27.3 °;
A photoreceptor having a photosensitive layer on which a charge transfer layer containing a polyester resin is laminated is subjected to digital image exposure, and in the development of the electrostatic latent image formed by this image exposure, a volume average particle diameter (D _V (3) using a toner having a particle size of 3 to 8 μm.

Another aspect of the present invention is an image forming apparatus including at least a photoconductor, an exposing device, and a toner, wherein the photoconductor is used for X-ray diffraction using CuKα radiation.
A photosensitive layer in which a charge generation layer containing oxytitanium phthalocyanine having a clear diffraction peak at a Bragg angle (2θ ± 0.2) of 27.3 ° and a charge transfer layer containing a polyester resin are laminated; The apparatus performs recording digital image exposure, and the volume average particle diameter (D
_V ) is 3 to 8 μm.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an outline of an image forming method and an image forming apparatus used in the present invention will be described for an electrophotographic recording apparatus using a non-magnetic one-component toner which is an example of a full-color image forming method. However, the present invention is not limited to this example. FIG. 1 is a schematic diagram of a main part configuration of an embodiment of an electrophotographic recording apparatus used in the present invention, and includes a photosensitive member 1, a charging device 2, an exposure device 3, a developing device 4,
It has a transfer device 5, a cleaning device 6, and a fixing device 7.

The photosensitive member 1 is formed of a conductor such as aluminum, for example, and has a photosensitive layer formed by coating a photosensitive conductive material on the outer peripheral surface. A charging device 2, an exposure device 3, a developing device 4, a transfer device 5, and a cleaning device 6 are arranged along the outer peripheral surface of the photoreceptor 1, respectively.

The charging device 2 includes, for example, a well-known scorotron charger, roller charger, and the like, and uniformly charges the surface of the photoconductor 1 to a predetermined potential. The exposure device 3 forms an electrostatic latent image on the photosensitive surface of the photoconductor 1 by exposing the photosensitive surface of the photoconductor 1 with an LED, a laser beam, or the like. In a preferred embodiment of the present invention, a charging device using contact charging is used.

The developing device 4 comprises an agitator 42, a supply roller 43, a developing roller 44, and a regulating member 45.
The toner T is stored therein. If necessary, the developing device may be provided with a replenishing device (not shown) for replenishing the toner, and the replenishing device can replenish the toner from a container such as a bottle or a cartridge.

The supply roller 43 is made of a conductive sponge or the like, and is in contact with the developing roller 44. The developing roller 44 is disposed between the photoconductor 1 and the supply roller 43. The developing roller 44 is in contact with the photoconductor 1 and the supply roller 43, respectively. The supply roller 43 and the developing roller 44 are rotated by a rotation drive mechanism. The supply roller 43 carries the stored toner and supplies it to the developing roller 44. Developing roller 44
Carries the toner supplied by the supply roller 43 and contacts the surface of the photoconductor 1.

The developing roller 44 is made of iron, stainless steel,
It is made of a metal roll of aluminum, nickel, or the like, or a resin roll in which a metal roll is coated with a silicon resin, a urethane resin, a fluororesin, or the like. The surface of the developing roll is
If necessary, the surface may be smoothed or roughened.

The regulating member 45 is formed of a resin blade such as a silicone resin or a urethane resin, a metal blade such as stainless steel, aluminum, copper, brass, phosphor bronze, or the like, or a metal blade coated with a resin. The regulating member 45 contacts the developing roller 44,
A predetermined force is applied to the developing roller 44 side by a spring or the like (a general blade linear pressure is 5 to 500 g / cm), and a function of imparting charge to the toner by frictional charging with the toner as necessary is provided. You may.

The agitator 42 is rotated by a rotary drive mechanism, and agitates the toner and conveys the toner to the supply roller 43 side. A plurality of agitators may be provided with different blade shapes, sizes, and the like.

The transfer device 5 includes a transfer charger, a transfer roller, a transfer belt, and the like, which are arranged to face the photosensitive member 1. The transfer device 5 applies a predetermined voltage value (transfer voltage) having a polarity opposite to the charged potential of the toner, and transfers the toner image formed on the photoconductor 1 to the recording paper P.

The cleaning device 6 comprises a cleaning member such as a urethane blade or a fur brush.
The cleaning device removes the residual toner attached to the photoreceptor 1 and collects the residual toner.

The fixing device 7 includes an upper fixing member 71 and a lower fixing member 72, and has a heating device 73 inside the upper or lower fixing member. As the fixing member, a known heat fixing member such as a fixing roll in which a metal tube of stainless steel, aluminum or the like is coated with silicon rubber, a fixing roll in which Teflon (registered trademark) resin is coated, a fixing sheet, and the like can be used. Further, a releasing agent such as silicone oil may be supplied to the fixing member to improve the releasing property. Further, a mechanism for forcibly applying pressure to the upper fixing member and the lower fixing member by a spring or the like may be employed.

When the toner transferred onto the paper P passes between the upper fixing member 71 and the lower fixing member 72 heated to a predetermined temperature, the toner is heated to a molten state, cooled after passing through, and recorded. The toner is fixed on the paper P.

In the electrophotographic developing apparatus configured as described above, an image is recorded as follows. That is, first, the surface (photosensitive surface) of the photoconductor 1 is charged to a predetermined potential (for example, −600 V) by the charging device 2. continue,
The charged photosensitive surface of the photoreceptor 1 is exposed by the exposure device 3 in accordance with an image to be recorded, and an electrostatic latent image is formed on the photosensitive surface. Then, the developing device 4 develops the electrostatic latent image formed on the photosensitive surface of the photosensitive member 1.

In the developing device 4, the toner supplied by the supply roller 43 is thinned by the developing blade 45, and has a predetermined polarity (here, the same polarity as the charging potential of the photoreceptor 1 and a negative polarity). After being triboelectrically charged, it is carried on the developing roller 44, transported, and brought into contact with the surface of the photoconductor 1.

From the developing roller 44, a toner image corresponding to the electrostatic latent image is formed on the surface of the photosensitive member 1 by a so-called reversal developing method. Then, the toner image is transferred to the sheet P by the transfer device 5. Thereafter, the toner remaining on the photosensitive surface of the photoconductor 1 without being transferred is removed by the cleaning device 6. The final image is obtained by passing the toner on the recording paper P through the fixing device 7 and thermally fixing the toner.

Next, an example of a tandem type electrophotographic recording apparatus using a non-magnetic one-component toner as a full color will be described. FIG. 2 is a schematic diagram of a main structure of a full-color tandem system, which includes a photosensitive member 1, a charging device 2, an exposure device 3, a black developing device 4k, a cyan developing device 4c, a yellow developing device 4y, a magenta developing device 4m, and a transfer device 5. , And a fixing device 7, and a cleaning device is omitted here. A color image can be obtained by superimposing magenta, yellow, cyan, and black toners in multiple layers and adjusting the color to a desired color.

In the case of the tandem system, it is better that the color developing section is located before the black developing section so that color mixture due to reverse transfer of black toner is reduced, and that the black developing section is located behind the color developing section. Reduces the color mixture due to photoreceptor fogging of the color toner when forming an image in a single color of black only, and can speed up the black image formation by conveying the recording paper by short-passing the color developing section. It is preferred.

When the image forming method of the present invention is applied to full-color image formation, such a cyan, magenta, and yellow color developing section is located at a front position, and a black developing section is located after a color developing section. Suitable for tandem type. The order in which the cyan, magenta, and yellow color developing units are located can be freely changed as needed.

[0027] The toner used in the present invention contains at least a binder resin and a colorant.
Waxes and other additives can be included. As a method for producing the toner used in the present invention, there are a method of increasing the accuracy of a classifier in a conventional pulverized toner and a method of producing by a polymerization method. It is preferable to use a wet polymerization method such as a polymerization method and an emulsion polymerization aggregation method. Further, it is more preferable to use an emulsion polymerization aggregation method from the viewpoint of preparing the toner having the particle diameter and circularity of the present invention and controlling the particle size distribution.

The binder resin used for the toner can be selected from a wide range including those conventionally known. Preferably, a styrene-based polymer such as a styrene-acrylate copolymer, a styrene-methacrylate copolymer, or an acrylic copolymer of these resins, a saturated or unsaturated polyester-based polymer, and an epoxy-based polymer are exemplified. be able to. Further, the binder resin is not limited to being used alone, and may be used in combination of two or more kinds.

The colorant may be an inorganic pigment, an organic pigment, an organic dye, or a combination thereof. Specific examples of these include carbon black,
Aniline blue, phthalocyanine blue, phthalocyanine green, hansa yellow, rhodamine dye, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallylmethane dye, monoazo dye,
Any known dyes and pigments such as disazo and condensed azo dyes can be used alone or in combination. In the case of a full-color toner, it is preferable to use benzidine yellow, a monoazo-based, condensed azo-based dye and pigment as yellow, quinacridone and monoazo-based dye and pigment as magenta, and phthalocyanine blue as cyan, respectively.

Of these, cyan colorants include C.I.
I. Pigment Blue 15: 3, and C.I. I. Pigment yellow 74, C.I. I. Pigment Yellow 93 and C.I. I. Pigment Red 238, C.I. I. Pigment Red 26
9, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Red 48: 2, C.I. I. Pigment Red 12
2 is preferably used. The amount of the colorant added is preferably in the range of 2 to 25 parts by weight based on 100 parts by weight of the binder resin.

The toner used in the present invention has a charge amount,
A charge control agent may be added for imparting charge stability.
As the charge control agent, a conventionally known compound is used.
Examples thereof include metal complexes of hydroxycarboxylic acids, metal complexes of azo compounds, naphthol compounds, metal compounds of naphthol compounds, nigrosine dyes, quaternary ammonium salts, and mixtures thereof. The addition amount of the charge control agent is preferably in the range of 0.1 to 5 parts by weight based on 100 parts by weight of the binder resin.

It is preferable to add a wax to the toner used in the present invention in order to impart releasability. Any wax can be used as long as it has a releasing property. Specifically, olefin waxes such as low molecular weight polyethylene, low molecular weight polypropylene and copolymerized polyethylene; paraffin wax; ester waxes having a long-chain aliphatic group such as behenyl behenate, montanic acid ester and stearyl stearate; hydrogenated Vegetable waxes such as castor oil carnauba wax; ketones having a long chain alkyl group such as distearyl ketone; silicones having an alkyl group; higher fatty acids such as stearic acid; long chain aliphatic alcohols such as eicosanol; glycerin, pentaerythritol Examples thereof include carboxylic acid esters or partial esters of polyhydric alcohols obtained from polyhydric alcohols and long-chain fatty acids; higher fatty acid amides such as oleic amide and stearic acid amide; low molecular weight polyesters and the like.

In order to improve the fixability among these waxes, the melting point of the wax is preferably 30 ° C. or more,
0 ° C. or higher is more preferable, and 50 ° C. or higher is particularly preferable.
Further, the temperature is preferably 100 ° C. or lower, more preferably 90 ° C. or lower, and particularly preferably 80 ° C. or lower. If the melting point is too low, the wax is likely to be exposed on the surface after fixing and sticky,
If the melting point is too high, the fixability at low temperatures is poor. Further, as the compound type of the wax, an ester wax obtained from an aliphatic carboxylic acid and a monohydric or polyhydric alcohol is preferable.
Those having 0 to 100 are more preferable, and those having 30 to 60 carbon atoms are particularly preferable.

The above waxes may be used alone or as a mixture. Further, the melting point of the wax compound can be appropriately selected depending on the fixing temperature at which the toner is fixed. The amount of the wax used is usually 0.1 to 4 in the toner.
0%, preferably 1-40%, more preferably 2-35
%, Particularly preferably 5 to 30%.

Next, a wet polymerization method will be described as a preferred method for producing the toner used in the present invention.

In the emulsion polymerization / aggregation method, a colorant dispersion, a charge control agent dispersion, a wax dispersion and the like are mixed with a dispersion of polymer primary particles, and the temperature, salt concentration, pH and the like are appropriately controlled. These are aggregated to produce a toner.

The emulsifier used in the emulsion polymerization includes at least one emulsifier selected from a cationic surfactant, an anionic surfactant and a nonionic surfactant. Specific examples of the cationic surfactant include dodecyl ammonium chloride, dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, hexadecyl trimethyl ammonium bromide, and the like. Specific examples of the anionic surfactant include fatty acid soaps such as sodium stearate and sodium dodecanoate, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, sodium lauryl sulfate and the like. Further, specific examples of the nonionic surfactant include polyoxyethylene dodecyl ether, polyoxyethylene hexadecyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene sorbitan monooleate ether, and monodecanoyl. And sucrose. Among these surfactants, alkali metal salts of linear alkylbenzene sulfonic acids are preferred.

In the suspension polymerization method, a colorant,
A charge controlling agent, wax and the like are mixed and subjected to a dispersion treatment using a disperser such as a disperser, and the monomer composition after the dispersion treatment is dispersed in a water-miscible medium using an appropriate stirrer. After granulating to a diameter, the polymerizable monomer is polymerized to produce a toner.

When a suspension stabilizer is used, it is preferable to select a neutral or alkaline one which can be easily removed by washing the toner after the polymerization with acid. Further, it is preferable to select a toner capable of obtaining a toner having a narrow particle size distribution. Suspension stabilizers that satisfy these requirements include calcium phosphate, tricalcium phosphate, magnesium phosphate, calcium hydroxide, magnesium hydroxide and the like. Each can be used alone or in combination of two or more. These suspension stabilizers can be used in an amount of 1 to 10 parts by weight based on the radical polymerizable monomer.

As the polymerization initiator used in the emulsion polymerization / aggregation method and the suspension polymerization method, one or a combination of two or more known polymerization initiators can be used. For example, potassium persulfate, 2,2'-azobisisobutyronitrile, 2,2'-azobisiso (2,4-dimethyl) valeronitrile, benzoyl peroxide, lauroyl peroxide, or a redox initiator is used. You can do it. Among these, a redox initiator is preferable in the emulsion polymerization / aggregation method, and an azo initiator is preferable in the suspension polymerization method. A toner having a capsule structure may be prepared by adding a polymer emulsion, a colorant dispersion, a charge control agent dispersion, a wax dispersion, and the like to the toner surface after the toner is manufactured by the above method.

Next, the emulsion polymerization / aggregation method, which is the most preferable method for producing the toner of the present invention, will be described in more detail. When a toner is produced by an emulsion polymerization / aggregation method, it usually has a polymerization step, a mixing step, an aggregation step, and a washing / drying step. That is, the dispersion containing the polymer primary particles obtained by emulsion polymerization is mixed with each dispersion such as a colorant, a charge control agent, and wax, and the primary particles in the dispersion are aggregated to obtain a volume average particle size of 3%. To about 8 μm, and, if necessary, resin fine particles and the like are adhered thereto, and if necessary, the particle aggregates or the particle aggregates to which the resin fine particles are adhered are fused, and the toner thus obtained is obtained. Washing particles,
Dry to obtain product toner particles.

Polymer Primary Particles The polymer primary particles used in the emulsion polymerization / aggregation method preferably have a glass transition temperature (Tg) of 40 to 80 ° C.
And the average particle size is usually from 0.02 to 3 μm. The polymer primary particles are obtained by emulsion polymerization of a monomer.

In the emulsion polymerization, a monomer having a Bronsted acidic group (hereinafter sometimes simply referred to as an acidic group) or a Bronsted basic group (hereinafter sometimes simply referred to as a basic group) is successively used. Is added, and a monomer having neither a Bronsted acidic group nor a Bronsted basic group (hereinafter, may be referred to as another monomer) causes polymerization to proceed. At this time, the monomers may be added separately, or a plurality of monomers may be mixed in advance and added. Further, the monomer composition can be changed during the addition of the monomer. Further, the monomer may be added as it is, or may be added as an emulsified liquid which is previously mixed and adjusted with water or an emulsifier. As the emulsifier, one or a combination of two or more of the above surfactants is selected.

Examples of the monomer having a Bronsted acidic group used in the present invention include monomers having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and cinnamic acid, and sulfonic acid groups such as sulfonated styrene. And monomers having a sulfonamide group such as vinylbenzenesulfonamide.

Examples of the monomer having a Bronsted basic group include aromatic vinyl compounds having an amino group such as aminostyrene, nitrogen-containing heterocyclic monomers such as vinylpyridine and vinylpyrrolidone, dimethylaminoethyl acrylate, and diethylamino. (Meth) acrylic acid esters having an amino group such as ethyl methacrylate;

The monomer having an acidic group and the monomer having a basic group may each be present as a salt with a counter ion. The blending ratio of the monomer having a Bronsted acidic group or a Bronsted basic group in the monomer mixture constituting the polymer primary particles is preferably 0.05% by weight or more, more preferably 1% by weight or more. And it is preferably at most 10% by weight, more preferably at most 5% by weight. Among monomers having a Bronsted acidic group or a Bronsted basic group, acrylic acid or methacrylic acid is particularly preferred.

Other comonomers include styrene,
Methyl styrene, chlorostyrene, dichlorostyrene,
styrenes such as p-tert-butylstyrene, pn-butylstyrene, pn-nonylstyrene, methyl acrylate, ethyl acrylate, propyl acrylate,
N-butyl acrylate, isobutyl acrylate, hydroxyethyl acrylate, ethyl hexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, hydroxyethyl methacrylate, ethylhexyl methacrylate, (Meth) acrylates, acrylamide, N-propylacrylamide, N, N-
Examples thereof include dimethylacrylamide, N, N-dipropylacrylamide, N, N-dibutylacrylamide, and acrylamide. Can be mentioned.
Among them, styrene, butyl acrylate and the like are particularly preferable.

Further, when a cross-linking resin is used for the polymer primary particles, a polyfunctional monomer having radical polymerizability is used as a cross-linking agent shared with the above-mentioned monomers, for example, divinylbenzene, hexanediol diacrylate, Examples include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol acrylate, diallyl phthalate, and the like. It is also possible to use a monomer having a reactive group in the pendant group, for example, glycidyl methacrylate, methylolacrylamide, acrolein and the like.

Preferably, a radically polymerizable bifunctional monomer is used, and more preferably, divinylbenzene or hexanediol diacrylate is used. The blending ratio of such a polyfunctional monomer in the monomer mixture is preferably at least 0.005% by weight, more preferably at least 0.1% by weight, particularly preferably at least 0.3% by weight. Preferably 5% by weight or less, more preferably 3% by weight or less,
It is particularly preferably at most 1% by weight.

These monomers are used singly or as a mixture. In this case, the glass transition temperature of the polymer is 40 or less.
~ 80 ° C is preferred. Glass transition temperature 80
If the temperature exceeds 100 ° C., the fixing temperature may become too high, or the OHP transparency may deteriorate. On the other hand, if the glass transition temperature of the polymer is lower than 40 ° C., the storage stability of the toner may deteriorate. is there.

The polymerization initiator may be added to the polymerization system at any time before, simultaneously with, or after addition of the monomer.
You may combine these addition methods as needed.
In the emulsion polymerization, a known chain transfer agent can be used if necessary. Specific examples of such a chain transfer agent include t-dodecyl mercaptan, 2-mercaptoethanol, diisopropylxanthogen, Carbon chloride, trichlorobromomethane, and the like. The chain transfer agent may be used alone or in combination of two or more kinds, and is used in an amount of 0 to 5% by weight based on the polymerizable monomer. Emulsion polymerization is
Mix the above monomers with water, in the presence of a polymerization initiator,
The polymerization is carried out, and the polymerization temperature is usually 50 to 150 ° C, preferably 60 to 120 ° C, and more preferably 70 to 100 ° C.

The volume average particle diameter of the polymer primary particles thus obtained is usually in the range of 0.02 μm to 3 μm, preferably 0.05 μm to 3 μm, more preferably 0.1 μm to 3 μm.
μm to 2 μm, particularly preferably 0.1 μm to 1 μm
m. The average particle size can be measured using, for example, UPA. When the particle size is smaller than 0.02 μm, it is difficult to control the agglomeration rate, which is not preferable. Also,
If it is larger than 3 μm, the particle size of the toner obtained by agglomeration tends to be large, which is unsuitable for producing a toner of 3 to 8 μm.

In the colorant emulsion polymerization / aggregation method, a dispersion of primary polymer particles and colorant particles are mixed to form a mixed dispersion, which is then aggregated to form a particle aggregate. The emulsion is preferably used in the form of an emulsion after emulsification in water in the presence of an emulsifier (the above-mentioned surfactant). The volume average particle size of the colorant particles is preferably 0.01 to 3 μm. The amount of the colorant used is usually 2 to 2 parts by weight based on 100 parts by weight of the polymer primary particles.
It is 5 parts by weight, preferably 3 to 20 parts by weight.

In the wax emulsion polymerization / aggregation method, it is preferable to use a wax that has been dispersed in the presence of an emulsifier (the above-mentioned surfactant) to form an emulsified wax fine particle dispersion. The wax is present in the agglomeration step. For example, the wax fine particle dispersion is co-aggregated with the polymer primary particles and the colorant particles. In some cases, a polymer primary particle containing the above is prepared and this and the colorant particles are aggregated. Of these, in order to uniformly disperse the wax in the toner, it is preferable that the wax fine particle dispersion is present at the time of preparing the above-mentioned polymer primary particles, that is, at the time of polymerizing the monomer.

The average particle diameter of the wax fine particles is 0.01 μm.
m to 3 μm, more preferably 0.1 to 2 μm
m, especially those having a diameter of 0.3 to 1.5 μm are preferably used. The average particle size is, for example, LA-500 manufactured by Horiba.
Can be measured. If the average particle size of the wax emulsion is larger than 3 μm, it tends to be difficult to control the particle size during aggregation, and if the average particle size of the wax emulsion is smaller than 0.01 μm,
It is difficult to make a dispersion.

Charge Control Agent In the emulsion polymerization / agglomeration method, the charge control agent is used as a seed when the polymer primary particles are obtained. Suitable for use as a toner by dissolving or dispersing it, or by aggregating primary particles of the charge control agent simultaneously with the primary particles of the polymer and the colorant to form a particle aggregate, or by aggregating the primary particles of the polymer and the colorant. After the particles have a suitable particle size, the particles can be aggregated by adding primary particles of the charge control agent. In this case, the charge control agent is also dispersed in water using an emulsifier (the above-described surfactant), and has an average particle size of 0.01 to 3 μm.
It is preferably used as an emulsion of m (primary particles of a charge control agent).

Mixing Step In the aggregating step of the production method of the present invention, the above-mentioned particles of the blending components such as the primary polymer particles, the colorant particles, the charge control agent, and the wax, if necessary, are mixed simultaneously or sequentially. However, dispersions of the respective components, that is, a polymer primary particle dispersion, a colorant particle dispersion, a charge control agent dispersion, and a wax fine particle dispersion are prepared beforehand. It is preferable to obtain a mixed dispersion by mixing. Further, it is preferable that the wax is contained in the toner by using polymer primary particles encapsulated in the polymer primary particles, that is, polymer primary particles obtained by emulsion polymerization using the wax as a seed. In this case, the polymer primary particles are used. It is possible to use the wax encapsulated in and the wax fine particles not encapsulated in combination, but it is more preferable to use substantially the entire amount of the wax in the form encapsulated in the polymer primary particles. is there.

Agglomeration Step The above-mentioned mixed dispersion of the particles is aggregated in the aggregation step to form a particle aggregate.
There are 1) a method of heating, 2) a method of adding an electrolyte, and 3) a method of combining these. When the primary particles are agglomerated under stirring to obtain a particle agglomerate almost in the size of the toner, the particle size of the particle agglomerate is controlled from the balance between the aggregating force between the particles and the shearing force due to the agitation. However, the cohesive force of the primary particles can be increased by heating or adding an electrolyte.

In the case of performing aggregation by heating, the aggregation temperature is, specifically, a temperature range of Tg-20 ° C. to Tg (where Tg is the glass transition temperature of the primary polymer particles).
The range of Tg-10 ° C to Tg-5 ° C is preferred. Within the above temperature range, the toner can be aggregated to a preferable toner particle size without using an electrolyte. Moreover, when performing aggregation by adding an electrolyte, the aggregation temperature is preferably 20 to 40C, more preferably 25 to 35C. The Tg of the polymer primary particles used in the present invention is preferably 40 to 80 ° C.
It is. In order to control the particle size of the toner particles having a predetermined particle size (3 to 8 μm), the toner particles having the desired particle size are obtained by maintaining the aggregation temperature at the predetermined temperature for at least 30 minutes to 1 hour. The temperature may be raised at a constant rate up to a predetermined temperature, or may be raised stepwise.

In the case where the electrolyte is added to the mixed dispersion to perform aggregation, either an organic salt or an inorganic salt may be used, but a monovalent or divalent or higher polyvalent metal salt is preferably used. Specifically, NaCl, KCl, LiC
1, Na ₂ SO ₄ , K ₂ SO ₄ , Li ₂ SO ₄ , MgCl ₂ ,
CaCl ₂ , MgSO ₄ , CaSO ₄ , ZnSO ₄ , Al ₂
(SO ₄ ) ₃ , Fe ₂ (SO ₄ ) ₃ , CH ₃ COONa, C ₆
H ₅ SO ₃ Na and the like. Of these, inorganic salts having a divalent or higher polyvalent metal cation are more preferable.

The amount of the electrolyte to be added varies depending on the type of the electrolyte, but is usually 0.05 to 25 parts by weight based on 100 parts by weight of the solid component of the mixed dispersion. Preferably 0.1 to 15 parts by weight, more preferably 0.1 to 10 parts by weight
Parts by weight. When the amount of the electrolyte added is significantly smaller than the above range, the progress of the agglutination reaction is slowed down and the
Problems tend to occur, such as fine powder having a particle size of not more than μm remaining or an average particle size of the obtained particle aggregate being not more than 3 μm. Further, when the amount of the electrolyte added is significantly larger than the above range, the aggregation tends to be rapid and difficult to control, and coarse particles of 25 μm or more are mixed in the obtained particle aggregate, or the shape of the aggregate is distorted. It tends to cause problems such as irregular shapes.

Other Ingredients Next, in the present invention, it is preferable to form toner particles by coating (adhering or fixing) resin fine particles on the surface of the particle aggregate after the above-mentioned aggregation treatment, if necessary. . When the above-described charge control agent is added after the aggregation treatment, it is preferable to add the resin fine particles after adding the charge control agent to the dispersion containing the particle aggregate.

The resin fine particles are used as an emulsion dispersed in water or a liquid mainly composed of water by an emulsifier (the above-mentioned surfactant). The resin fine particles used for the outermost layer of the toner do not contain wax. preferable. As the resin fine particles, preferably, the volume average particle size is from 0.02 to
Those having a size of 3 μm, more preferably 0.05 to 1.5 μm, obtained by polymerizing a monomer similar to the monomer used for the above-mentioned polymer primary particles can be used. When the toner is formed by coating the particle aggregate with resin fine particles, the resin used for the resin fine particles is preferably cross-linked.

Aging Step In the emulsion polymerization / aggregation method, in order to increase the stability of the particle aggregate (toner particles) obtained by aggregation, Tg + 20 ° C.
It is preferable to add a ripening step of causing fusion between aggregated particles in the range of Tg + 80 ° C. (where Tg is the glass transition temperature of the primary polymer particles). In the aging step, it is preferable to maintain the temperature in the above-mentioned temperature range for 1 hour or more. By adding the aging step, the shape of the toner particles can be made nearly spherical, and the shape can be controlled. This aging step is usually performed for 1 hour to 24 hours, preferably 1 hour to 10 hours. Although the particle aggregate before the aging step is considered to be an aggregate due to electrostatic or other physical aggregation of the primary particles, after the aging step, the polymer primary particles constituting the particle aggregate are fused to each other. And
Preferably it is substantially spherical. In addition, according to such a method for producing a toner, various shapes such as a grape type in which primary particles are aggregated, a potato type in which fusion has progressed halfway, a spherical shape in which fusion has further progressed, and the like depending on purposes. A toner can be manufactured.

Washing / Drying Step The particle aggregate obtained through each of the above steps is subjected to solid-liquid separation according to a known method, and the particle aggregate is recovered. After drying, the desired toner particles can be obtained. In this manner, a toner having a relatively small volume average particle diameter of 3 to 8 μm can be manufactured. Moreover, the toner thus obtained has a sharp particle size distribution and is suitable as a toner for developing an electrostatic image for achieving high image quality and high speed.

A known external additive may be added to the toner for developing an electrostatic image used in the present invention in order to control fluidity and developability. As the external additive, various kinds of inorganic oxide particles such as silica, alumina, titania and the like (which may be subjected to a hydrophobic treatment if necessary), vinyl polymer particles and the like can be used. The amount of the external additive is preferably in the range of 0.05 to 5 parts by weight based on the toner particles.

The toner of the present invention can be applied to a magnetic one-component developer such as a two-component developer and a magnetite-containing toner, and a non-magnetic one-component developer. When the toner of the present invention is used as a two-component developer, as a carrier that is mixed with the toner to form a developer, a known magnetic substance such as an iron powder-based, ferrite-based, and magnetite-based carrier,
Those having a resin coating on their surface or a magnetic resin carrier can be used.

As the coating resin for the carrier, generally known styrene resins, acrylic resins, styrene-acryl copolymer resins, silicone resins, modified silicone resins, fluorine resins and the like can be used. It is not limited. The average particle size of the carrier is not particularly limited, but preferably has an average particle size of 10 to 200 microns. These carriers are preferably used in an amount of 5 to 100 parts by weight based on 1 part by weight of the toner.

A method for measuring the particle size of the toner is as follows.
A commercially available particle size measuring apparatus can be used, but typically, a precision particle size distribution measuring apparatus manufactured by Beckman Coulter KK Coulter Counter Multisizer II
Is used. The toner used in the present invention has a volume average particle size (D _V ) of 3 to 8 μm. Volume average particle size is 4 ~
8 μm is preferred, and 4-7 μm is more preferred. If the volume average particle diameter is too large, it is not suitable for forming a high-resolution image, and if it is too small, handling as a powder becomes difficult.

The sharper the particle size distribution of the toner, the more easily the chargeability becomes uniform. In particular,
In the image forming method and apparatus according to the present invention, the relationship between the volume average particle diameter (D _V ) and the number average particle diameter (D _N ) is 1.0 ≦
Those satisfying Dv / Dn ≦ 1.3 are used. _DV / _DN
Is preferably 1.25 or less, more preferably 1.25 or less. Further, the lower limit of D _V / D _N is 1, which means that all particle diameters are equal, and it is difficult to manufacture. Therefore, 1.03 or more is preferable, and 1.05 or more is more preferable. preferable.

It is preferable that the toner has few fine particles (fine powder). When the number of fine particles is small, the fluidity of the toner is improved, and the colorant, the charge control agent and the like are uniformly distributed, and the chargeability is likely to be uniform. For measuring fine particles, for example, a flow particle image analyzer FPIA-2000 manufactured by Sysmex Corporation is preferably used. In the present invention, 0.6 μm to 2.0 μm by a flow type particle image analyzer.
It is preferable to use a toner whose measured value (number) of 12 μm particles is 15% or less of the total number of particles. This means that the fine particles are less than a certain amount,
The number of particles of μm to 2.12 μm is more preferably 10% or less, particularly preferably 5% or less. The lower limit of the fine particles is not particularly limited, and it is most preferable that the fine particles do not exist at all. However, it is difficult to manufacture the fine particles, and usually 0.5% or more, and preferably 1% or more.

The shape of the toner is preferably as spherical as possible. Specifically, as a method of quantifying the shape of the toner, the toner is measured by a flow particle image analyzer FPIA-2000 manufactured by Sysmex Corporation, and the cumulative value at 50% of the value obtained from the following equation (II) is measured. When the circularity corresponding to the particle size value is defined as 50% circularity, those having a 50% circularity in the range of 0.9 to 1 are preferable.

[0073]

## EQU00002 ## Circularity = perimeter of circle having the same area as particle projection area / perimeter of particle projection image (II)

The 50% circularity of the toner indicates the degree of unevenness of the toner particles, and is 1 when the toner is perfectly spherical. As the surface shape becomes more complicated, the value of the circularity decreases. As the shape becomes closer to a sphere, the localization of the charge amount in the solid particles is less likely to occur, and the developability tends to be uniform. Accordingly, 50% of the toner is more preferably 0.92 or more, and 0.9% or more.
Particularly preferred is 5 or more. Further, since it is difficult to produce a perfect sphere in production, it is preferably 0.995 or less, more preferably 0.99 or less.

Next, the photosensitive member used in the present invention will be described. The photoreceptor used in the present invention, on a conductive support,
This is a laminated photoreceptor in which a charge generation layer and a charge transfer layer are stacked, and includes at least a conductive support, a charge generation layer, and a charge transfer layer. Usually, the charge transfer layer is the outermost layer and is most closely related to the releasability from the toner and the durability of the photoreceptor. Therefore, the photoreceptor used in the present invention preferably has a photosensitive layer in which a charge transfer layer is laminated on a charge generation layer.
Further, in addition to the charge generation layer and the charge transfer layer, a layer for improving electric characteristics and mechanical characteristics such as an intermediate layer such as an adhesive layer and a blocking layer, and a protective layer may be provided. In particular, even when a protective layer is provided on the charge transfer layer, it is preferable to use the same binder resin as the charge transfer layer defined by the present invention for the protective layer. Furthermore, in the case where the protective layer is a relatively thin layer of 8 μm or less, considering that the protective layer is scraped off during use, even if another protective resin is used for the protective layer, The present invention is useful.

As the conductive support, any of those used for known photoreceptors can be used. Specifically, for example, a metal drum or sheet of aluminum, stainless steel, copper, etc., or a laminate of these metal foils And a deposit. Further, plastic films, plastic drums, paper, paper tubes, and the like, which have been subjected to a conductive treatment by applying a conductive substance such as metal powder, carbon black, copper iodide, and a polymer electrolyte together with a suitable binder, may be mentioned. Further, a plastic sheet or drum containing a conductive substance such as a metal powder, carbon black, or carbon fiber to become conductive may be used. Further, plastic films and belts which have been subjected to conductive treatment with a conductive metal oxide such as tin oxide or indium oxide may be used.

When used in a small, high-speed electrophotographic apparatus, the conductive support is preferably in the form of a drum, and in this case, the drum diameter is usually 10 to 40 mm, preferably 13 to 35 mm, and more preferably. 16 to 30 mm. Moreover, especially in the case of a small device, 13 to 25 mm
Is preferred. The above-described small-diameter drum is particularly advantageous in the case of a color electrophotographic apparatus, in which a photoconductor is used for each of the four color toners of cyan, magenta, yellow, and black.

A blocking layer may be provided between the conductive support and the charge generation layer, if necessary. The blocking layer may be an alumite layer, a resin-based undercoat layer (also referred to as an intermediate layer), or a combination thereof. Is used.

When an alumite layer is provided, an aluminum substrate is used as a conductive support, and the aluminum substrate is first degreased by various degreasing methods such as acid, alkali, organic solvent, surfactant, emulsion, and electrolysis. Is preferred. Next, anodizing treatment is performed in an acidic bath such as chromic acid, sulfuric acid, oxalic acid, boric acid, and sulfamic acid, preferably in a sulfuric acid bath, to form an anodized film (alumite layer). The average thickness of the anodic oxide coating is usually 1
-20 μm, preferably 1-7 μm. The alumite layer formed as described above is immersed in water, water flow,
Washing is performed by spraying with water, washing by physical contact with a brush, foam, or cloth-like rubbing material, or a combination of these, followed by drying such as air drying and heat drying. You.

The charge generating layer contains at least a binder polymer and a charge generating agent. In the present invention, oxytitanium phthalocyanine is used as the charge generating agent. This may contain an organic photoconductive compound, a dye, an electron-accepting compound, and the like, if necessary. As the binder used for the charge generation layer, styrene,
Polymers and copolymers of vinyl compounds such as vinyl acetate, vinyl chloride, acrylates, methacrylates, vinyl alcohol and ethyl vinyl ether, polyvinyl acetal, polycarbonate, polyester, polyamide, polyurethane, cellulose ester, cellulose ether, phenoxy resin , Silicon resin, epoxy resin and the like. The ratio of oxytitanium phthalocyanine to binder polymer is not particularly limited, but generally, 5 to 500 parts by weight, preferably 20 to 300 parts by weight, of binder polymer is used per 100 parts by weight of oxytitanium phthalocyanine.

One of the features of the present invention resides in that a specific crystalline oxytitanium phthalocyanine is used as a charge generating agent. The crystalline oxytitanium phthalocyanine used in the present invention has a clear diffraction peak at a Bragg angle (2θ ± 0.2) 27.3 ° in X-ray diffraction using CuKα ray. The X-ray diffraction is measured by a general Bragg-Brentano concentration method. Also, the diffraction intensity is usually expressed in cps.

The crystalline oxytitanium phthalocyanine is disclosed in, for example, FIG. 2 of JP-A-62-67094 (referred to as type II in the same publication) and JP-A-2-82.
No. 56 of FIG. 1, FIG. 1 of JP-A-64-17066, FIG. 1 of JP-A-63-20365, Journal of the Society of Electrophotographic Photography, Vol. 92 (1990), No. 3. 250
２５258 (referred to as Y-type in the same publication). In the present specification, the crystalline oxytitanium phthalocyanine used in the present invention will be referred to as a Y-type according to the name given in academic publications.

The Y-type is distinguished from the α-type and the β-type since it is characterized by showing the maximum diffraction peak at 27.3 ° according to the Bragg-Brentano concentration method. For example, JP-A-3-128973, JP-A-3-269064
The crystal form described in Japanese Patent Publication No.
It is considered a type. In the case of a Y-type peak other than 27.3 °, the peak intensity ratio may change due to its crystallinity, or the peak may become broad and the peak top position may shift (this is because the crystal is Not strong), typically 7.4%, 9.7%,
A peak is shown at 24.2 °.

In recent years, X-ray diffraction by the transmission method in which the crystal orientation has been eliminated as much as possible has been performed, and a capillary is used as a sample holder.
In the transmission X-ray diffraction according to the method described above, the Y-type crystal usually has a Bragg angle (2θ ± 0.2) of 21.3 °, 18.9 °, and 7.
It shows peaks at 6 ° and 5.8 °. This corresponds to 27.3 °, 24.2 °, 9.7 °, and 7.4 ° by CuKα radiation, respectively. In high-resolution X-ray diffraction,
The peak corresponding to 9.7 ° is resolved into two or more peaks.

In the present invention, a charge generating agent other than Y-type oxytitanium phthalocyanine may be mixed and used for the purpose of adjusting the sensitivity, etc.
The charge generating substance is α-type oxytitanium phthalocyanine,
If only a titanium-containing phthalocyanine compound such as β-oxytitanium phthalocyanine is mixed, the proportion of the Y-type oxytitanium phthalocyanine in the charge generating agent is usually 30% by weight or more, preferably 50% by weight or more, and more preferably 70% by weight. % Or more is more preferable. Further, if it is mixed with a charge generating agent other than the titanium-containing phthalocyanine compound, the proportion of the Y-type oxytitanium phthalocyanine in the charge generating agent is usually 40% by weight or more, and 60% by weight.
It is preferably at least 80% by weight, more preferably at least 80% by weight.

The thickness of the charge generation layer is 0.05 to 5 μm,
Preferably it is 0.1 to 2 μm. Charge carriers are injected from the charge generation layer. The charge transfer layer contains a carrier transfer medium having high carrier injection efficiency and transfer efficiency.

The charge transfer layer contains at least a binder and a charge transporting agent, and if necessary, contains an antioxidant, an electron withdrawing substance, an ultraviolet absorber, a wax, a leveling agent and the like. As the charge transport agent, poly-N
-Vinylcarbazole, a high molecular compound having a heterocyclic compound such as polystyrylanthracene or a condensed polycyclic aromatic compound in a side chain, as low molecular compounds, pyrazoline,
Heterocyclic compounds such as imidazole, oxazole, oxadiazole, triazole and carbazole; triarylalkane derivatives such as triphenylmethane; triarylamine derivatives such as triphenylamine; phenylenediamine derivatives; N-phenylcarbazole derivatives; stilbene Derivatives, hydrazone compounds, and the like are mentioned, and in particular, compounds having a large electron donating property, which are substituted by an electron donating group such as a substituted amino group or an alkoxy group, or an aromatic ring group having these substituents. Of these, formula (IV), formula (V), formula (VI),
A compound having an atomic group represented by the formula (VII) or (VIII) is preferable.

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Specific examples of preferred compounds as the charge transport agent are shown below. In addition, (A-1)-of the following specific examples
(A-14) is a compound having an atomic group represented by Formula (IV), (B-1) to (B-8) are compounds having an atomic group represented by Formula (V), (C-1) to (C-
5) is a compound having an atomic group represented by the formula (VI), and (D-1) to (D-3) are compounds having an atomic group represented by the formula (VII).

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Further, in the present invention, a polyester resin is used as a binder polymer of the charge transfer layer. The polyester resin used in the present invention comprises a polybasic acid component and a polyhydric alcohol component. As the polybasic acid component, maleic anhydride, maleic acid, those using unsaturated acids such as fumaric acid, phthalic anhydride, terephthalic acid,
Aromatic saturated acids such as isophthalic acid; aliphatic saturated acids such as hexahydrophthalic anhydride, succinic acid, and azelaic acid are used. Polyhydric alcohol components include ethylene glycol, propylene glycol, butylene glycol,
Alkylene glycols such as neopentyl glycol; polyalkylene glycols such as diethylene glycol, dipropylene glycol, triethylene glycol and tripropylene glycol; various bisphenols; aromatic diols such as hydrogenated bisphenol and phenylglycidyl ether; and polyols such as glycerin. Can be
Among them, a polyester composed of an aliphatic saturated acid, an aliphatic unsaturated acid, an aromatic saturated acid and various bisphenols is preferable, and a polyester resin having a structural unit represented by the following general formula (Ia) is more preferable. Used.

[0100]

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(In the general formula (Ia), Ar ¹ and Ar ² each independently represent a benzene ring which may have a substituent;
Is a divalent aliphatic hydrocarbon group which may have a substituent, a benzene ring which may have a substituent, a naphthalene ring which may have a substituent, and a biphenyl ring which may have a substituent Represents R ¹ and R ² each independently have a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, an acyloxy group which may have a substituent, and a substituent. Represents an arylsulfoxy group, and R ¹ and R ² may be linked to each other to form a cyclic structure. )

In the general formula (Ia), Ar ¹ and Ar ² represent a benzene ring which may have a substituent, and examples of the substituent include a halogen atom, a cyano group, a nitro group, a hydrocarbon group,
A hydrocarbon group substituted with a halogen atom, an alkoxy group,
An alkoxy group and an alkylthio group substituted with a halogen atom are preferred, and among them, a methyl group, a cyclohexyl group, a phenyl group, and an allyl group are more preferred. Also, Ar
¹ and Ar ² are also preferably unsubstituted. X represents an aliphatic hydrocarbon group which may have a substituent, a benzene ring which may have a substituent, a naphthalene ring which may have a substituent, and a biphenyl ring which may have a substituent. However, the aliphatic hydrocarbon group preferably has 2 to 6 carbon atoms. Further, as a substituent of these aliphatic hydrocarbon groups or a benzene ring, a naphthalene ring or a biphenyl ring, a halogen atom,
Preferable are a cyano group, a nitro group, a hydrocarbon group, a hydrocarbon group substituted with a halogen atom, an alkoxy group, an alkoxy group substituted with a halogen atom, and an alkylthio group. Among these, a fluorine atom, a chlorine atom, a bromine atom, and methyl Groups, methoxy groups, trifluoromethyl groups and trifluoromethoxy groups are more preferred. X is also preferably unsubstituted.

R ¹ and R ² are a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, an acyloxy group which may have a substituent, Represents an arylsulfoxy group which may have a group, and R ¹ and R ² may be linked to form a ring structure. Of these, a hydrogen atom, a methyl group, and a phenyl group are preferable;
It is also preferred that R ¹ and R ² are linked to form a cyclohexane ring. Further, as these substituents, a fluorine atom and a chlorine atom are preferable, and an unsubstituted one is also preferable. Further, a structural unit represented by the following general formula (Ib) is preferable.

[0104]

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(In the general formula (Ib), R^Three, R^FourAre independent
And may be substituted with a hydrogen atom or a halogen atom
May be substituted with an alkyl group or a halogen atom
Represents a phenyl group. Also, R^Three, R^FourAre connected to each other
A structure may be formed. R ^Five~ R⁸Are each independently water
Alkyl which may be substituted by a hydrogen atom or a halogen atom
Represents a hydroxyl group. ) In the present invention, as a component of the polyester resin
And a structural unit represented by the general formula (Ia)
Although a structural unit other than (Ia) may be used in combination,
In that case, the structural unit represented by the general formula (Ia) is
It is preferably at least 50% of the ester resin,
More preferably, it is at least 70%. Preferred polyet
Specific examples of the stell resin are shown below.

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When the charge transporting agent is a polymer compound having a polyester structure, it is not particularly necessary to use another binder resin, but mixing may be carried out for improving flexibility. In normal use, a low-molecular charge transport material compound is used. In that case, the amount of the binder resin is usually 50 to 1 based on 100 parts by weight of the charge transport agent.
000 parts by weight, preferably 100 to 500 parts by weight. In addition to the above, various additives for improving the mechanical strength and durability of the coating film can be used in the charge transfer layer. Examples of such additives include well-known plasticizers, various stabilizers, flowability-imparting agents, and crosslinking agents. The thickness of the charge transfer layer is generally 10 to 60 μm, preferably 1 to 60 μm.
It is 5 to 45 μm, more preferably 27 to 40 μm.

In addition, as long as the effects of the present invention are not impaired,
As the binder resin, a resin other than polyester (for example, a polycarbonate resin) can be mixed and used. However, in order to keep the mold release property and the durability higher, the proportion of the polyester resin used should be the binder resin of the charge transfer layer. The total amount is preferably 40% or more, more preferably 60% or more, and particularly preferably 80% or more.

The undercoat layer, charge generation layer and charge transfer layer described above are dissolved or dispersed in an appropriate solvent depending on the binder and the components used, and are spray-coated, spiral-coated, ring-coated, dip-coated. Provided by law. In the case of the dip coating method, the total solid concentration is preferably 25 to
A coating solution having a viscosity of 40%, preferably 50 to 300 centipoise, more preferably 100 to 200 centipoise, is prepared. As a drying method after the application, a hot air dryer, a steam dryer, an infrared dryer, a far infrared dryer, or the like can be used.

Next, as an exposure device for performing exposure for forming a latent image on the photoreceptor, a device for performing digital exposure is used. In consideration of the absorbance of the above-mentioned Y-type oxytitanium phthalocyanine, it is 530 to 850 nm. Is preferable. More specifically, 5
Around 32 nm, around 635 nm, around 650 nm, 78
An exposure apparatus that emits a laser beam near 0 nm or 830 nm is preferable. Of these, around 635 nm,
An exposure apparatus that emits a laser beam near 650 nm or 780 nm is preferable.

The charging method used in the present invention includes:
A contact type or a proximity type in which the distance between the photosensitive member and the charging member is 1 mm or less is preferably employed. The contact-type or proximity-type charging method can be performed by a simpler device than a non-contact charging method such as scorotron charging, and has an advantage that the device can be easily reduced in size and weight. Further, the contact type or the proximity type is advantageous in that the amount of generated ozone is small and the power supply required for charging can be reduced. Of these, the proximity type has no contact with the photoreceptor and is advantageous in that the photoreceptor is shaved, but requires the formability of hardness in order to maintain the accuracy of the proximity distance. In the present invention, since a high-strength polyester resin is used as a binder resin for the charge transfer layer of the photoconductor, it is particularly effective for an apparatus employing a contact charging system.

As the charging device used in the contact or proximity charging system, a charging device in which a charging member such as a resin having semiconductivity is provided on a conductive core material such as a metal is used.
As the shape of the charging device, there are a sheet shape, a film shape, a roller shape, and the like, but a roller shape which can reduce the number of components structurally and causes relatively little wear of the photoreceptor is preferable. The charging device used in the present invention has the following formula (II)
It is preferable to have a charging member satisfying I). Here, the charging member refers to a portion of the charging device other than the conductive core material.

[0135]

[Formula 3] logRmax−logRmin ≦ 0.5 (III) Rmax: maximum value of volume resistance Rmin: minimum value of volume resistance

When the charging member satisfies the formula (III), the charging of the photosensitive member becomes uniform, and accordingly, the electrostatic latent image after the exposure becomes high definition. The charging member preferably has a volume resistance of 10 ³ to 10 ¹⁴ Ω · cm.

In the present invention, in the above-described image formation using the photosensitive member, the exposure device, and the toner, in the development after the dot exposure of the photosensitive member, particularly when the number of dots is as large as 600 dpi or more, the volume average particle diameter of the toner is reduced. Is 3 to 8 μm, and when a polyester resin is used as a binder resin for the photoconductor, both the adhesion of the toner to the latent image and the releasability from the photoconductor at the time of transfer are improved. Therefore, a high-gradation, high-resolution latent image can be faithfully reproduced. Further, the circularity of the toner is from 0.9 to 1, especially from 0.
When the ratio is 95 to 1, it has no sharp corners, is close to a circle, and has a shape with little unevenness. Therefore, it is possible to develop the latent image having a small dot area so as to reproduce the latent image more completely. It is estimated that it will be possible.

Further, the adhesion force (mirror image force, van der Waals force, etc.) of the toner particles to the photoreceptor is larger than the Coulomb force applied to the toner particles during transfer, which is seen in the small particle size toner. As a result, the tendency to increase the transfer residual toner can be improved by setting the 50% circularity to 0.9 to 1, and can be further improved by using the polyester resin for the photoconductor. Further, since such toner has a uniform particle shape, localization of the charge amount within the individual particle due to the difference in particle shape is unlikely to occur, and as a result, almost all of the particles remain on the photoreceptor. It is considered that the latent image is faithfully reproduced because it adheres with a uniform force.

Further, by using the above oxytitanium phthalocyanine as a charge generating substance of the photoreceptor, the photoreceptor has high sensitivity, and can be effectively applied to a smaller, high-speed, high-resolution image forming apparatus. Therefore, the image forming method of the present invention is particularly effective when forming an image having a resolution of 600 dpi or more, and more preferably 1200 dpi or more, and is particularly effective when the rotation speed of the photoreceptor is 1.5 times / second or more. It is effective, and is particularly effective when the inner diameter of the photosensitive member is 30 mm or less.

[0140]

The present invention will be described in detail with reference to the following examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. In the following examples, “parts” means “parts by weight”. The average particle size, weight average molecular weight, glass transition point (Tg), 50% circularity, and melting point of the wax were measured by the following methods.

Volume average particle size, number average particle size: LA-500 manufactured by Horiba, Microtrack UPA (ul) manufactured by Nikkiso Co., Ltd.
tra particle analyzer) and a Coulter Counter Multisizer II (Coulter Counter).

Weight average molecular weight (Mw): Measured by gel permeation chromatography (GPC) (apparatus: GPC apparatus HLC-8020 manufactured by Tosoh Corporation, column: PL-gel Mixed-B 10μ manufactured by Polymer Laboratory,
(Solvent: THF, sample concentration: 0.1 wt%, calibration curve: standard polystyrene)

Glass transition temperature (Tg): Measured by DSC7 manufactured by PerkinElmer (heated from 30 ° C. to 100 ° C. in 7 minutes, rapidly cooled from 100 ° C. to −20 ° C., and then cooled from −20 ° C. to 100 ° C.)
The temperature was raised in 12 minutes, and the value of Tg observed during the second temperature increase was used).

Number of particles having a particle size of 0.6 to 2.12 μm: Measured by a flow particle image analyzer FPIA-2000 manufactured by Sysmex Corporation.

50% circularity: The toner was measured with a flow type particle image analyzer FPIA-2000 manufactured by Sysmex Corporation, and the circularity corresponding to the cumulative particle size at 50% of the value obtained from the following equation was used. Circularity = Perimeter of a circle with the same area as the projected area of the particle / Perimeter of the projected image of the particle

Examples A1 to A3, Comparative Examples B1 to B3 [Production of toner for development-1 (TA1)] (Wax dispersion-1) 68.33 parts of demineralized water, stearic acid ester of pentaerythritol (Unistar H-47)
6, 30 parts of Nippon Yushi, sodium dodecylbenzenesulfonate (Neogen SC, manufactured by Daiichi Kogyo Seiyaku, active ingredient 66)
%) And emulsified by applying high-pressure shearing at 90 ° C. to obtain a dispersion of fine particles of ester wax. LA-500
The average particle size of the ester wax fine particles measured in 340 nm
Met.

(Polymer Primary Particle Dispersion-1) A reactor equipped with a stirrer (three blades), a heating / cooling device, a concentrating device, and a device for charging raw materials and auxiliaries (volume: 60 liter, inner diameter: 40)
0 mm), 28 parts of a wax dispersion liquid, 1.2 parts of a 15% neogen SC aqueous solution, and 393 parts of demineralized water were charged, and heated to 90 ° C. under a nitrogen stream, 1.6 parts of an 8% hydrogen peroxide aqueous solution, 8 parts of ascorbic acid 1.6 parts of an aqueous solution were added. Thereafter, a mixture of the following monomers / emulsifier aqueous solution was added over 5 hours from the start of the polymerization, and the aqueous initiator solution was added over 6 hours from the start of the polymerization.
Minutes.

[0148]

[Table 1] [Monomers] Styrene 79 parts (5530 g) Butyl acrylate 21 parts Acrylic acid 3 parts Bromotrichloromethane 0.45 parts 2-mercaptoethanol 0.01 parts Hexanediol diacrylate 0.9 parts [Emulsifier aqueous solution] 15% Neogen SC aqueous solution 1 Part Demineralized water 25 parts [Initiator aqueous solution] 8% hydrogen peroxide aqueous solution 9 parts 8% ascorbic acid aqueous solution 9 parts

After the completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer dispersion. The weight-average molecular weight of the polymer soluble in THF is 12
7,000, the average particle diameter measured by UPA was 220 nm, and Tg was unclear.

(Resin Particle Dispersion-1) A reactor equipped with a stirrer (three blades), a heating / cooling device, a concentrating device, and a device for charging each raw material and auxiliary agent (capacity: 60 liters, inner diameter: 400 mm)
5 parts of 15% neogen SC aqueous solution and 372 parts of demineralized water were charged, and the temperature was increased to 90 ° C. under a nitrogen stream, and 1.6% of an 8% aqueous hydrogen peroxide solution was added.
And 1.6 parts of an 8% aqueous ascorbic acid solution. Thereafter, a mixture of the following monomers and an aqueous solution of an emulsifier was added over 5 hours from the start of the polymerization, and an aqueous solution of the initiator was added over 6 hours from the start of the polymerization, and the mixture was further maintained for 30 minutes.

[0151]

[Table 2] [Monomers] Styrene 88 parts (6160 g) Butyl acrylate 12 parts Acrylic acid 2 parts Bromotrichloromethane 0.5 parts 2-mercaptoethanol 0.01 parts Hexanediol diacrylate 0.4 parts [Emulsifier aqueous solution] 15% Neogen SC aqueous solution 2.5 Part Demineralized water 24 parts [Initiator aqueous solution] 8% hydrogen peroxide aqueous solution 9 parts 8% ascorbic acid aqueous solution 9 parts

After the completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer dispersion. The weight-average molecular weight of the polymer soluble in THF is 54,
000, average particle diameter measured by UPA was 83 nm, and Tg was 85 ° C.

(Colorant Fine Particle Dispersion-1) Pigment Blue 15: 3 aqueous dispersion (EP-700 Blue GA, manufactured by Dainichi Seika, solid content 35%) The average particle size measured by UPA was 150 nm. .

[0154]

Table 3 Production of toner for development-1 Polymer primary particle dispersion-1 103 parts (2773 g: as solid) Resin fine particle dispersion-1 5 parts (as solid) Colorant fine particle dispersion-1 6.7 parts 0.5% of 15% Neogen SC aqueous solution (as solid content)

Using each of the above components, a toner was produced according to the following procedure. A polymer primary particle dispersion and a 15% aqueous solution of neogen SC were charged into a reactor (volume: 60 liters, anchor blade with baffle), mixed uniformly, and then a colorant fine particle dispersion was added, followed by uniform mixing. While stirring the obtained mixed dispersion, an aqueous solution of aluminum sulfate was added dropwise (0.6 part as a solid content). Thereafter, with stirring, the temperature was raised to 50 ° C over 25 minutes, held for 1 hour, and further maintained at 60 ° C for 15 minutes.
And held for 1 hour and 35 minutes. A resin fine particle dispersion and an aqueous solution of aluminum sulfate (0.07 part as solids) were added in this order, and the temperature was raised to 62 ° C. over 5 minutes and maintained for 30 minutes. After adding a 15% aqueous solution of Neogen SC (3 parts as a solid content), the temperature was raised to 96 ° C. over 50 minutes and maintained for 3 hours. Then cool down,
The toner was obtained by filtration, washing with water and drying.

To 100 parts of this toner, 0.6 part of hydrophobic surface-treated silica was mixed and stirred, and a developing toner (T
A1) was obtained. Evaluation of Toner-1 The volume average particle diameter of the developing toner (TA1) measured by a Coulter counter is 7.2 μm, the ratio of particles having a particle diameter of 5 μm or less is 2.5%, the ratio of particles having a particle diameter of 15 μm or more is 0.8%, and the particle diameter is 0. .6
The ratio of the number of particles having a particle size of .about.2.12 μm is 0.39%, the ratio of the particle size of 55% or less of the volume average particle size is 0.39% by volume, and the ratio of the particle size of 40% or less of the volume average particle size is 1. 37% by number. Dv / Dn = 1.13, and the 50% circularity was 0.95.

[Production of toner for development-2 (TA2)] (Wax dispersion-2) 68.33 parts of demineralized water and an ester mixture mainly composed of behenyl behenate (Unistar M-2222S)
L, Nippon Oil & Fats) and ester mixture mainly composed of stearyl stearate (Unistar M9676, Nippon Oil & Fats) 7: 3
And 1.67 parts of sodium dodecylbenzenesulfonate (Neogen SC, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., active ingredient 66%) were mixed and emulsified by applying high-pressure shear at 90 ° C. to obtain a dispersion of ester wax fine particles. Was. The average particle size of the ester wax fine particles measured by LA-500 was 340 nm. (Polymer primary particle dispersion liquid-2) Wax dispersion liquid in a reactor (volume: 60 liters, inner diameter: 400 mm) equipped with a stirrer (three blades), a heating / cooling device, a concentrating device, and a device for charging raw materials and auxiliaries. -Charge 28 parts, 1.2 parts of 15% neogen SC aqueous solution and 393 parts of demineralized water, raise the temperature to 90 ° C under a nitrogen stream, and add 1.6 parts of 8% aqueous hydrogen peroxide and 1.6 parts of 8% ascorbic acid aqueous solution. did. Thereafter, a mixture of the following monomers and an aqueous solution of an emulsifier was added over 5 hours from the start of the polymerization, and an aqueous solution of the initiator was added over 6 hours from the start of the polymerization, and the mixture was further maintained for 30 minutes.

[0158]

[Table 4] [Monomers] Styrene 79 parts Butyl acrylate 21 parts Acrylic acid 3 parts Bromotrichloromethane 0.45 parts 2-mercaptoethanol 0.01 parts Hexanediol diacrylate 0.9 parts [Emulsifier aqueous solution] 15% Neogen SC aqueous solution 1 part Demineralized water 25 parts [Initiator aqueous solution] 8% Hydrogen peroxide aqueous solution 9 parts 8% Ascorbic acid aqueous solution 9 parts

After the completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer dispersion. The weight-average molecular weight of the polymer soluble in THF is 14
The average particle size measured by 8,000 and UPA was 207 nm, and Tg was 55 ° C. (Resin Particle Dispersion-2) The same as Resin Particle Dispersion-1 was used. (Colorant Fine Particle Dispersion-2) Pigment Yellow 74 20
Part, polyoxyethylene alkyl phenyl ether 7
Parts, 73 parts of demineralized water in a sand grinder mill,
A colorant fine particle dispersion was obtained. Average particle size measured by UPA is 2
It was 11 nm. (Charge control agent fine particle dispersion liquid-2) 4,4'-methylenebis [2-
[N- (4-chlorophenyl) amide] -3-hydroxynaphthalene] 20 parts, alkyl naphthalene sulfonate 4
And 76 parts of desalinated water were dispersed in a sand grinder mill to obtain a charge control agent fine particle dispersion. The average particle size measured by UPA was 200 nm.

[0160]

Table 5 Production of toner for development-2 Polymer primary particle dispersion-2 105 parts (as solids) Resin fine particle dispersion-1 5 parts (as solids) Colorant fine particles dispersion-2 6.7 parts (solids) 2) 2 parts (as solid content)

Using each of the above components, a toner was produced according to the following procedure. A polymer primary particle dispersion and a colorant fine particle dispersion were charged into a reactor (volume: 1 liter, anchor wing with baffle) and uniformly mixed. While stirring the obtained mixed dispersion, an aqueous solution of aluminum sulfate was added dropwise (0.6 part as a solid content). Thereafter, with stirring, the temperature was raised to 51 ° C. over 25 minutes and maintained for 1 hour, and further raised to 59 ° C. over 8 minutes and maintained for 40 minutes. Charge control agent fine particle dispersion, resin fine particle dispersion, aluminum sulfate aqueous solution (as solid content
0.07 parts), and the temperature was raised to 61 ° C. over 15 minutes and maintained for 30 minutes. 15% Neogen SC aqueous solution (3.8 parts as solid content)
Was added and the temperature was raised to 96 ° C. over 30 minutes and maintained for 4 hours. Thereafter, the mixture was cooled, filtered, washed with water, and dried to obtain a toner. To 100 parts of this toner, 0.6 part of silica subjected to a hydrophobic surface treatment was mixed and stirred to obtain a developing toner (TA2).

Evaluation of Toner-2 The volume average particle diameter of the developing toner (TA2) measured by a Coulter counter is 7.5 μm, the ratio of particles having a particle diameter of 5 μm or less is 1.6%, the ratio of particles having a particle diameter of 15 μm or more is 0.7%, Particle size 0.6
The ratio of the number of particles of .about.2.12 μm is 0.46%, the ratio of the particle size of 55% or less of the volume average particle size is 0.26% by volume, and the ratio of the particle size of 40% or less of the volume average particle size is 1. It was 29 number%. Dv / Dn = 1.14 and the 50% circularity was 0.96.

[Production of Developing Toner-3 (TA3)] (Wax Dispersion-3) A dispersion produced in the same manner as in Wax Dispersion-2 was used. The average particle size of the ester wax fine particles measured by LA-500 was 340 nm. (Polymer Primary Particle Dispersion-3) Wax Fine Particle Dispersion-
The polymer was prepared in the same manner as in Polymer Primary Particle Dispersion-2 using No.3. The weight average molecular weight of the polymer soluble in THF is 119,000, the average particle diameter measured by UPA is 189 nm, Tg
Was 57 ° C. (resin fine particle dispersion-3) The same as resin fine particle dispersion-1 was used. (Colorant Fine Particle Dispersion-3) 20 parts of Pigment Red 238 (compound of the following formula (A)), 2.5 parts of alkylbenzenesulfonate, and 77.5 parts of demineralized water are dispersed in a sand grinder mill to obtain a colorant particle dispersion. Obtained. The average particle size measured by UPA was 181 nm.

[0164]

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[0165]

(Table 6) (Charge Control Agent Fine Particle Dispersion-3) The same as Charge Control Agent Fine Particle Dispersion-2 was used. Production of toner for development-3 Polymer primary particle dispersion-3 104 parts (as solids) Resin fine particle dispersion-16 parts (as solids) Colorant particle dispersion-3-3 6.7 parts (as solids) Charge Control agent fine particle dispersion-2 2 parts (as solid content) 15% Neogen SC aqueous solution 0.65 parts (as solid content)

Using each of the above components, a toner was manufactured by the following procedure. A polymer primary particle dispersion and a 15% aqueous solution of neogen SC were charged into a reactor (volume: 1 liter, anchor wing with baffle), uniformly mixed, and then a colorant fine particle dispersion was added and uniformly mixed. While stirring the obtained mixed dispersion, an aqueous solution of aluminum sulfate was added dropwise (0.8 part as a solid content). Then take 15 minutes with stirring 51
° C and maintained for 1 hour, and further raised to 59 ° C over 6 minutes and maintained for 20 minutes. Charge control agent fine particle dispersion, resin fine particle dispersion, aluminum sulfate aqueous solution (solid content of 0.09
Parts) and kept at 59 ° C. for 20 minutes. 15% Neogen S
After the addition of the C aqueous solution (3.7 parts as a solid content), the temperature was raised to 95 ° C. over 25 minutes, and the 15% neogen SC aqueous solution (0.7 parts as a solid content) was further added and maintained for 3.5 hours. Thereafter, the mixture was cooled, filtered, washed with water, and dried to obtain a toner.

To 100 parts of this toner, 0.6 part of silica having been subjected to hydrophobic surface treatment was mixed and stirred, and a developing toner (T
A3) was obtained. Evaluation of Toner-3 The volume average particle size of the developing toner (TA3) measured by a Coulter counter is 7.8 μm, the ratio of the volume particle size of 5 μm or less is 2.1%, the ratio of the volume particle size of 15 μm or more is 2.1%, and the particle size. The ratio of the number of particles of 0.6 to 2.12 μm is 0.80%, the ratio of the particle size of 55% or less of the volume average particle size is 0.51% by volume,
The ratio of the particle size of 40% or less of the volume average particle size was 1.85% by number. Also, Dv / Dn = 1.15 and 50
The% circularity was 0.97.

(Production Example 1 of Photoreceptor) (Alumite layer)
An aluminum cylinder having a length of 340 mm and a thickness of 1 mm was treated with a degreasing agent, NC- # 30 (manufactured by Kizai Co., Ltd.) at 30 g /
Degreasing and washing were performed in an aqueous solution at 60 ° C. for 5 minutes. Subsequently, after rinsing with water, it was immersed in 7% nitric acid at 25 ° C. for 1 minute. After further washing with water, anodic oxidation was carried out at a current density of 1.2 A / dm ^{2 in} a 180 g / l sulfuric acid electrolytic solution (dissolved aluminum concentration: 7 g / l) to form an anodized film having an average film thickness of 6 μm. Next, after washing with water, it was immersed in a 10 g / l aqueous solution of a high-temperature sealing agent Top Seal DX-500 (manufactured by Okuno Pharmaceutical Co., Ltd.) containing nickel acetate as a main component at 95 ° C. for 30 minutes to perform a sealing treatment. Subsequently, after washing with water, the entire surface of the coating film was reciprocated three times using a polyester sponge to carry out rubbing washing. Then, it was washed with water and dried.

(Undercoat layer) Titanium oxide manufactured by Ishihara Sangyo Co., Ltd., product name TTO-55N (crystal rutile primary particle size: 0.03-0.05 μm), mixed alcohol (methanol / 1-propanol = 70 / 30) was dispersed in a ball mill for 16 hours. The titanium oxide dispersion obtained here was added to a mixed alcohol (methanol / 1-propanol = 70/30) solution of the following polyamide resin (PA-1). Finally, a dispersion having a solid content concentration of 16% with a titanium oxide / nylon ratio of 1/1 (weight ratio) was prepared and used as a dispersion for the undercoat layer.

[0170]

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The above drum (aluminum cylinder)
Was applied by dip coating to the undercoat layer dispersion, and an undercoat layer was provided so that the dry film thickness was 0.75 μm (charge generation layer). Β-oxytitanium phthalocyanine (β-TiOP)
Preparation of c) 97.5 g of phthalodinitrile was converted to α-chloronaphthalene 7
50 ml of titanium tetrachloride 2 under a nitrogen atmosphere.
2 ml are added dropwise. After dropping, the temperature is increased and 200
After reacting at ~ 220 ° C for 3 hours, it is allowed to cool, and
The mixture was filtered while hot at 30 ° C., and washed with 200 ml of α-chloronaphthalene heated to 100 ° C. 200ml of N-
The hot suspension washing treatment (100 ° C., 1 hour) with methylpyrrolidone was performed three times. Subsequently, the resultant was washed with 300 ml of methanol at room temperature, and further hot-washed with 500 ml of methanol for 1 hour three times. The X-ray diffraction spectrum of the oxytitanium phthalocyanine thus obtained is shown in FIG. As is apparent from FIG. 1, there is no substantial peak between 4 ° and 8 ° at the black angle (2θ ± 0.2 °), and 9.3 ° and 10 °.
6 ゜, 13.2 ゜, 15.1 ゜, 15.7 ゜, 16.1
{20.8}, 23.3}, 26.3}, and 27.1} have distinct diffraction peaks, of which the 26.3} peak is the strongest.

Production of Y-type oxytitanium phthalocyanine (Y-type TiOPc) The β-type oxytitanium phthalocyanine produced as described above is subjected to a grinding treatment for 20 hours by a sand grind mill, followed by 400 ml of water. The solution was placed in a suspension of 40 ml of orthodichlorobenzene and heat-treated at 60 ° C. for 1 hour. The oxytitanium phthalocyanine thus obtained was analyzed by X-ray diffraction (CuKα ray, Bragg-Brentano concentration method) to obtain a black angle (2θ ± 0.2).
゜) had a maximum at 27.3 ° and showed a sharp peak.

When the Y-type oxytitanium phthalocyanine thus obtained was subjected to transmission X-ray diffraction at 1.2085 ° using a capillary as a sample holder, a Bragg angle (2θ ± 0.2 °) of 21.3 was obtained. ° (1
00) (However, the values in parentheses indicate a peak intensity at 21.3 ° of 10).
Relative intensity when 0), 18.9 ° (13), 1
4.1 ° (12), 11.8 ° (14), 11.1 °
(11), 9.2 ° (11), 7.6 ° (36), 7.
A diffraction peak was observed at 4 ° (25) and 5.8 ° (8). The measuring device was a multiple detector X-ray powder diffractometer. Details of the device were published by High Energy Physics Laboratory.
"Radiation Powder Diffraction Experiment Station (BL-4B) Design Report, (1995), KEK Report
94-11 ". The measurement conditions are a step angle of 0.005 °, 4.5 seconds / step, and a wavelength for d value calculation = 1.2085 °.

Preparation and Application of Coating Solution for Charge Generating Layer 10 parts of the Y-type TiOPc obtained in the above production example was
In addition to 150 parts by weight of methoxy-4-methylpentanone-2, pulverization and dispersion treatment was performed with a sand grind mill. In addition, polyvinyl butyral (Electrical Chemical Industry Co., Ltd.)
Made, 5% of trade name Denka Butyral # 6000C)
100 parts of a 1,2-dimethoxyethane solution and 5 of phenoxy resin (PKHH, manufactured by Union Carbide Co.)
100 parts of a 1,2-dimethoxyethane solution were mixed to prepare a binder solution. Pigment dispersion liquid 1 prepared earlier
To 60 parts by weight, 100 parts by weight of a binder solution and an appropriate amount of 1,2-dimethoxyethane were added to finally prepare a dispersion having a solid content of 4.0%. The dispersion thus obtained was further applied by dip coating on the aluminum drum to which the undercoat layer had been applied to form a charge generation layer having a thickness of 0.2 μm.

(Charge Transfer Layer) 60 parts of the charge transfer material of the structural formula (B-5), and polyester [(P-1) and (M-
1) 7: 3 copolymer polyester resin (viscosity average molecular weight 33,000)], 100 parts, 4-methyl-2,6-di-t
Eight parts of ert-butylphenol and 0.03 part of silicone oil (KF-96, manufactured by Shin-Etsu Silicones) were dissolved in a mixed solvent of 170 parts of dioxane and 400 parts of tetrahydrofuran to prepare a coating solution. Then, a charge transfer layer was provided on the aluminum drum coated with the undercoat layer and the charge generation layer by dip coating so that the film thickness after drying at 125 ° C. for 20 minutes was 20 μm. This is designated as photoconductor "PC-A1".

[Example A1] Color manufactured by CASIO
The toner cyan toner (TA1) is put in a developing tank for Pagepresto N4-612II, and a photoconductor (PC)
-A1) was mounted and an image was formed at an exposure density of 600 dpi.
It is a book, the resolution-2 is 33 μm, and the resolution-3 is 33 μm.

Resolution-1 Exposure was performed so as to draw 6, 9, and 12 equally spaced vertical lines per mm as a print image, and an image was formed.
The number of vertical lines per mm was visually evaluated to determine how many lines could be used. The higher the number, the higher the definition.・ Resolution-2 About 80 μm, about 55 μm, about 40 as print image
Exposure was performed so as to draw a fine line of about 33 μm, and an image was formed and evaluated. Higher definition is possible when an image can be formed up to a thinner line.・ Resolution-3 As a print image, about 55 μm, about 4
Exposure was performed so as to draw a fine line (white outline) of about 33 μm of 0 μm, and an image was formed and evaluated. Higher definition is possible when an image can be formed up to a thinner line.

[Comparative Example B1] In Example A1, N4-6 was used instead of the cyan toner (TA1).
When image formation was performed in the same manner as in Example 1 except that 12 genuine kneaded / crushed cyan toner (TB1) was used, the resolution-1 was 12, the resolution-2 was 33 μm, and the resolution-3 Was 40 μm. The volume average particle diameter (D _V ) of TB1 is 9.10 μm, and D _V / D _N = 1.2.
4, 50% circularity is 0.93, particle size 0.6 to 2.12μ
The particle number ratio of m was 4.8%.

Example A2 An image was formed in the same manner as in Example A1, except that the yellow toner (TA2) was used instead of the cyan toner (TA1). An image having the same resolution as in Example A1 is obtained.

Example A3 An image was formed in the same manner as in Example A1, except that the magenta toner (TA3) was used instead of the cyan toner (TA1). An image having the same resolution as in Example A1 is obtained.

Examples A4 to A9, Comparative Examples B2 to B5 [Production of developing toner-4 (TA4 to TA10)] (Preparation of colorant dispersion) a) Colorant dispersion A I. Pigment Red 238 40g, Deionized Water 1
55 g and 5 g of an alkylbenzene sulfonate were added, and a dispersion treatment was performed with a sand grinder mill for 6 hours to obtain a colorant dispersion A having an average particle size of 0.18 μm.

B) Colorant dispersion B I. Pigment Blue 15: 3 60 g and demineralized water 1
30 g and 10 g of polyoxyethylene alkylphenyl ether were added, and the mixture was dispersed with a sand grinder for 6 hours to obtain a colorant dispersion B having an average particle size of 0.15 μm. C) Colorant dispersion C 40 g of I Pigment Yellow 74 and 14 parts of demineralized water
6g, polyoxyethylene alkyl phenyl ether 1
4 g was added, and the mixture was dispersed by a sand grinder mill for 6 hours to obtain a colorant dispersion C having an average particle size of 0.30 μm.

D) Colorant Dispersion D To 40 g of carbon black (MA100, manufactured by Mitsubishi Chemical),
146 g of demineralized water and 14 g of polyoxyethylene alkylphenyl ether were added, and the mixture was subjected to a dispersion treatment with a sand grinder mill for 6 hours to obtain a colorant dispersion D having an average particle diameter of 0.30 μm.

(Synthesis of polymer emulsion) 3.4 kg of an ester wax emulsion having a solid content of 30% and 27 kg of demineralized water were put into a reactor and heated to 90 ° C., and 6 g of dodecylbenzenesulfonate, 5 kg of styrene, n-butyl 1.3 kg of acrylate, 190 g of acrylic acid, 26 g of divinylbenzene, 32 g of trichlorobromomethane, 677 g of 8% aqueous hydrogen peroxide, 67% of 8% aqueous ascorbic acid
7 g were added. The reaction was continued at 90 ° C. for 7 hours to obtain an emulsion (polymer primary particle dispersion) composed of a styrene acrylic polymer.

(Preparation of Charge Control Agent Dispersion) To 40 g of 4,4'-methylenebis [2- [N- (4-chlorophenyl) amide] -3-hydroxynaphthalene] was added 1 ml of demineralized water.
60 g and 8 g of alkyl naphthalene sulfonate were added, and the mixture was subjected to dispersion treatment for 2 hours by a sand grinder mill to obtain a charge control agent dispersion.

(Production of Toner) a) Toner (TA4) 16 g of a colorant dispersion and 1.6 g of a charge control agent dispersion were mixed and stirred with 300 g of a polymer emulsion. 87 g of 0.5% Al ₂ (SO ₄ ) ₃ was added thereto while stirring was continued.
The temperature was raised to 0 ° C., and stirring was continued. 2 g of dodecylbenzenesulfonate was added, the temperature was raised to 98 ° C., and stirring was continued for 7 hours. The obtained particles were repeatedly subjected to suction filtration and washing with water, followed by air-drying to obtain 60 g of a magenta toner. The particle size of the obtained particles was measured using a Coulter counter. The volume average particle size was 7.5 μm, and the number average particle size was 6.8.
μm. When the circularity was measured using FPIA-2000, the 50% circularity was 0.99. The ratio of particles having a particle size of 0.6 to 2.12 μm was 6% by number. To 100 parts of the toner, 1 part of silica having been subjected to a hydrophobic surface treatment was mixed and stirred to obtain a developing toner (referred to as TA4).

B) Toner (TA5) A toner was prepared in the same manner as in the toner (TA4) except that the colorant dispersion B was used instead of the colorant dispersion A used in the toner (TA4). 0.5 μm, number average particle size 6.9 μm, 50% circularity 0.99, 0.6 to 0.6
57 g of cyan toner in which the ratio of 2.12 μm particles was 4% by number was obtained. An external addition process was performed in the same manner as the toner (TA4) to obtain a developing toner (this is referred to as TA5).

C) Toner (TA6) The toner (TA4) was manufactured in the same manner as the toner (TA4) except that the colorant dispersion C was used instead of the colorant dispersion A used in the toner (TA4). 0.3 μm, number average particle size 6.3 μm, 50% circularity 0.99, 0.6 to
57 g of a yellow toner having a ratio of 2.12 μm particles of 3% by number was obtained. An external addition process was performed in the same manner as the toner (TA4) to obtain a developing toner (this is referred to as TA6).

D) Toner (TA7) A toner was prepared in the same manner as in the toner (TA4) except that the colorant dispersion D was used instead of the colorant dispersion A used in the toner (TA4). 0.3 μm, number average diameter 6.3 μm, 50% circularity 0.98, 0.6-2.
57 g of a black toner having a ratio of 12 μm particles of 4% by number was obtained. An external addition process was performed in the same manner as the toner (TA4) to obtain a developing toner (this is referred to as TA7).

E) Toner (TA8) The toner (TA4) was manufactured in the same manner as the toner (TA4) except that the amount of Al ₂ (SO ₄ ) ₃ used was changed to 50 g. 5 μm, number average particle size 5.3 μm, 50% circularity 0.98, 0.6 to 2.12
60 g of a magenta toner having 7% by number of μm particles was obtained. An external addition process was performed in the same manner as the toner (TA4) to obtain a developing toner (referred to as TA8).

F) Toner (TA9) A toner (TA9) was manufactured in the same manner as the toner (TA4), except that the temperature rise time from 25 ° C. to 60 ° C. was changed from 2 hours to 30 minutes. Average particle size 6.2μ
m, a 50% circularity of 0.98, and 60 g of a magenta toner having a particle ratio of 16% by number of 0.6 to 2.12 μm.
An external addition process was performed in the same manner as the toner (TA4) to obtain a developing toner (referred to as TA9).

G) Toner (TA10) (Comparative Toner) Polyester resin (Tg = 60 ° C., Sp = 135 ° C., 1
% Crosslinking) 94 parts, Pigment Blue 15: 3 at 40%
Masterbatch 10 of the polyester resin contained
Part, 4-4 ′ methylene bis [2- [N
-(4-Chlorophenyl) amide] -3-hydroxynaphthalene], 1 part of the mixture was melt-kneaded, and then pulverized and classified to obtain a volume average diameter of 9.5 μm, a number average diameter of 7.5 μm, and 50 parts.
A cyan toner having a% circularity of 0.94 was obtained. Toner (TA
An external addition process was performed in the same manner as in 4) to obtain a toner (this is referred to as a toner TA10).

(Production example 2 of photoreceptor) (Comparative photoreceptor: β
The process up to the alumite layer and the undercoat layer was performed in the same manner as in Production Example 1 of the photoreceptor. (Charge Generating Layer) A charge generating layer was provided on the alumite layer in the same manner as in the production of the charge generating layer in Production Example 1 of the photoreceptor except that β-type TiOPc was used instead of Y-type TiOPc.

(Charge Transfer Layer) A charge transfer layer was provided on the charge generation layer in the same manner as in the manufacture of the charge transfer layer in Production Example 1 of the photoreceptor. This is designated as photoconductor "PC-B1".

(Production of Photoreceptor-3) In the production of Photoreceptor-1, a polycarbonate resin (Europin Z20 manufactured by Mitsubishi Gas Chemical Company) was used as a binder resin for the charge transfer layer.
A photoconductor having a laminated photosensitive layer was obtained in the same manner as in Production-1 of photoconductor except that (0) was used (this was designated as PC-B2).

(Evaluation Method) The photoconductors PC-A1, PC-B1, and PC-B2 obtained as described above were subjected to CASI.
Company O Color Pagepresto N4-612
An image was formed at an exposure density of 600 dips mounted on II, and the following items were evaluated. The results are shown in Table 1.

(A) Gradation A print roller having an image mode in which the image density can be determined in ten levels based on the area ratio of the halftone dots was connected, and how many levels the printed image could be determined was evaluated. . (B) Resolution-1 Evaluation was made by forming vertical lines at equal intervals per 1 mm on the printed image. At 600 dpi, 6, 9, and 12 were evaluated.

(C) Resolution-2 Evaluation was made based on the reproducibility of an isolated dot having a diameter of 50 μm on the printed image. A: Very good reproducibility B: Good C: Insufficient resolution

(D) Image Quality The presence or absence of fog after the 2,000-sheet durability test was evaluated. A: No change from the initial stage B: Fog slightly increased compared to the initial stage C: Fog significantly increased compared to the initial stage

[0200]

[Table 7]

(Evaluation of Mechanical Characteristics of Photoreceptor) [Example C1]

(Production Example 4 of Photoconductor) Production Example of Photoconductor-
In place of the aluminum drum used in 1, a polyester film having an aluminum vapor-deposited layer on the surface was used, and a coater coater was used in place of dip coating to produce the same as the photoconductor (PC-A1). A sheet-shaped photosensitive member was obtained. This is referred to as a photoconductor (PC-A2). [Friction test] Toner TA4 was applied to the above-mentioned film-shaped photoconductor P
A cloth of urethane rubber of the same material as the cleaning blade cut to a width of 1 cm is used at an angle of 45 ° using a uniform surface of 0.1 mg / cm ² on C-A2 at a load of 200 g and speed. 1 when urethane rubber is moved 100 times at 5 mm / s, stroke 20 mm
The 00th dynamic friction coefficient was measured with a fully automatic friction and wear tester DFPM-SS manufactured by Kyowa Interface Chemical Co., Ltd. Second result
It is shown in the table.

[Wear Test] The above-mentioned film-shaped photosensitive member PC
-A2 was cut into a circle having a diameter of 10 cm, and the wear was evaluated using a Taber abrasion tester (manufactured by Toyo Seiki Co., Ltd.). The test conditions were as follows: 23 ° C., 50% RH atmosphere, worn wheel CS-1
Using 0F, the amount of wear after 1000 rotations without load (the weight of the worn wheel) was measured by comparing the weight before and after the test. The results are shown in Table 2.

[Comparative Example D1]

(Production Example 5 of Photoconductor) Production Example of Photoconductor-
4, a polycarbonate resin (Europin Z2 manufactured by Mitsubishi Gas Chemical Company) was used as a binder resin for the charge transfer layer.
A sheet-shaped photoreceptor was obtained in the same manner as in the photoreceptor (PC-A2) except that (00) was used. The photoconductor (PC-B)
3). Film-shaped photoconductor PC-A2 of Example C1
The mechanical properties were evaluated in the same manner as in Example C1, except that PC-B3 was used instead of. The results are shown in Table 2.

[0206]

[Table 8]

[0207]

By using the above-mentioned specific titanyl phthalocyanine for a photoreceptor and combining it with digital exposure and a toner having a specific volume average particle diameter, an image with high gradation and high resolution can be obtained. Further, the present invention can be advantageously applied to a small and high-speed electrophotographic apparatus.

[0208]

[Brief description of the drawings]

FIG. 1 is a schematic view of an example of an image forming apparatus used in the present invention.

FIG. 2 is a schematic diagram of main components of an example of a tandem type full-color image forming apparatus used in the present invention.

[Explanation of symbols]

 Reference Signs List 1 photoconductor 2 charging device 3 exposure device 4 developing tank 4k black developing tank 4y yellow developing tank 4c cyan developing tank 4m magenta developing tank 5 transfer device 6 cleaning device 7 fixing device 42 agitator 43 supply roller 44 developing roller 45 regulating member 71 upper part Fixing member 72 Lower fixing member T Toner P Recording paper

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Tomoko Ishikawa 1000 Kamoshita-cho, Aoba-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Chemical Corporation Yokohama Research Laboratory F-term (reference) 2H005 AA06 AA15 AB06 CA14 EA03 EA05 EA07 EA10 2H068 AA13 AA19 BA39 BB23 BB27

Claims (15)

[Claims] 1. A charge generation layer containing oxytitanium phthalocyanine showing a clear diffraction peak at least at a Bragg angle (2θ ± 0.2) of 27.3 ° in X-ray diffraction with CuKα ray, and a polyester resin. A photoreceptor having a photosensitive layer on which a charge transfer layer is laminated is subjected to digital image exposure. In the development of the electrostatic latent image formed by the image exposure, the volume average particle diameter (D _V ) is 3 to 8 μm. An image forming method, characterized by using a toner which is as follows. 2. The polyester resin represented by the general formula (I)
2. The image forming method according to claim 1, comprising a structural unit represented by a). Embedded image (In the general formula (Ia), Ar ¹ and Ar ² each independently represent a benzene ring which may have a substituent, X is a divalent aliphatic hydrocarbon group which may have a substituent, Benzene ring which may have a substituent, naphthalene ring which may have a substituent,
Represents a biphenyl ring which may have a substituent. R ¹ and R ²
Are each independently a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, an acyloxy group which may have a substituent, and an aryl which may have a substituent Represents a sulfoxy group, and R ¹ and R ² may be linked to each other to form a cyclic structure. ) 3. The method according to claim 1, wherein the polyester resin has the general formula (I)
Claims characterized by having a structural unit represented by b)
Item 2. The image forming method according to Item 1. Embedded image(In the general formula (Ib), R^Three, R^FourAre each independently a hydrogen source
, An alkyl group which may be substituted with a halogen atom,
Or a phenyl group which may be substituted with a halogen atom
Represent. Also, R^Three, R^FourAre connected to each other to form an annular structure
May be. R ^Five~ R⁸Are each independently a hydrogen atom or ha
The alkyl groups that may be substituted with
You. ) 4. The toner according to claim 1, wherein a 50% circularity corresponding to a cumulative particle size value at 50% of a value obtained from the following formula (II) is 0.9 to 1. Image forming method. ## EQU00001 ## Circularity = perimeter of circle having the same area as particle projection area / perimeter of particle projection image (II) 5. The image forming method according to claim 1, wherein the toner contains at least a binder resin and a colorant, and is obtained by a wet polymerization method. 6. The image forming method according to claim 5, wherein the toner is obtained through a step of aggregating at least polymer primary particles and colorant particles to form a particle aggregate. 7. The image forming method according to claim 1, wherein the toner has a particle size of 0.6 μm to 2.12 μm measured by a flow type particle analyzer of 15% by number or less. 8. The toner according to claim 1, wherein a relationship between a volume average particle diameter (D _V ) and a number average particle diameter (D _N ) is 1.0 ≦ D _V / D _N ≦ 1.
The image forming method according to claim 1, wherein the number is in the range of 3. 9. The image forming method according to claim 1, wherein the toner contains 1 to 40% of a wax. 10. The image forming method according to claim 9, wherein the melting point of the wax is 30 to 100 ° C. 11. The image forming method according to claim 10, wherein the wax contains a fatty acid alkyl ester having 10 to 30 carbon atoms. 12. The image forming method according to claim 10, wherein the wax contains a fatty acid ester of a polyhydric alcohol having 15 to 50 carbon atoms. 13. The recording dot density in digital image exposure is 600 dots / inch or more.
2. The image forming method according to 1., 14. The light wavelength in digital image exposure is 5
14. The image forming method according to claim 1, wherein the light is in a range of 30 to 850 nm. 15. An image forming apparatus comprising at least a photoconductor, a charging device, and a toner, wherein the photoconductor is CuK.
In X-ray diffraction using α rays, the Bragg angle (2θ ± 0.
2) A photosensitive layer in which a charge generation layer containing oxytitanium phthalocyanine having a clear diffraction peak at 27.3 ° and a charge transfer layer containing a polyester resin are laminated, and the exposure apparatus performs digital image exposure. An image forming apparatus, wherein the volume average particle diameter (D _V ) of the toner is 3 to 8 μm.