JP2001117262A - Dry toner and method of forming image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dry toner which has excellent environmental stability and electrification characteristics, which stably realizes high-quality images for a long time, which does not exert adverse influences on a toner carrying body or the like and which is highly suitable for an electrophotographic process. SOLUTION: The dry toner has toner particles containing at least a binder resin, coloring agent and wax component. The content of the wax component is 1 to 30 parts by mass to 100 parts by mass of the binder resin. The toner contains 50 to 100 mass% of an ester compound expressed by formula A or B or a mixture of these (based on the mass of the wax component). In formulae, R3 to R7 may be the same or different groups and each represents a 10-40C organic group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry toner (hereinafter referred to as "toner") used in a recording method utilizing an electrophotographic method, an electrostatic recording method, a magnetic recording method, a toner jet method or the like. The present invention relates to an image forming method using toner. More specifically, the present invention relates to a toner used in an image recording apparatus that can be used in a copying machine, a printer, a facsimile, a plotter, and the like, and an image forming method using the toner.

[0002]

2. Description of the Related Art Conventionally, electrophotography has been disclosed in U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910.
Numerous methods are known as described in Japanese Patent Application Laid-Open Publication No. Hei. Generally, on a photoreceptor using a photoconductive substance, an electrostatic image is formed by various means, and then the electrostatic image is developed using toner, and if necessary, using direct or indirect means, After a toner image is transferred onto a transfer material such as paper, it is fixed by heating, pressurizing, heating and pressurizing, or solvent vapor to obtain a copy or print. The untransferred toner remaining on the photoreceptor without being transferred is cleaned by various methods, and the above steps are repeated.

In a full-color or multi-color image forming method, for example, a photosensitive drum (or a photosensitive belt) is uniformly charged by a primary charger, and an image is formed on a document by a laser beam modulated by, for example, a magenta image signal. Exposure is performed to form an electrostatic image on the photosensitive drum, and the electrostatic image is developed by a magenta developing device having magenta toner, thereby forming a magenta toner image on the photosensitive drum. The magenta toner image on the photosensitive drum is transferred onto the intermediate transfer member. Next, similarly to the case of the magenta toner, the development and transfer of the second color, the development and transfer of the third color, and the development and transfer of the fourth color are performed. The four-color toner image is transferred from the laminated intermediate transfer member having the four-color toner image to the transfer material, and the four-color toner image on the transfer material is fixed by a heat and pressure fixing unit to form a full-color or multi-color image. Is formed on the transfer material.

In a full-color or multi-color image forming method using four photosensitive drums and a transfer belt, a first color toner image is formed on a first photosensitive drum and a second color toner image is formed on a second photosensitive drum. A second color toner image, a third color toner image on the third photosensitive drum, a fourth color toner image on the fourth photosensitive drum, and a transfer material on the transfer belt. While moving, the first to fourth color toner images on the first to fourth photosensitive drums are sequentially transferred onto a transfer material, and the first to fourth color toner images on the transfer material are fixed by heating and pressing fixing means. Thus, a full-color or multi-color image is formed on the transfer material.

In a full-color or multi-color image using one photosensitive drum (or photosensitive belt) and a transfer drum for carrying a transfer material, a first color toner image is formed on the photosensitive drum and then The first color toner transfer is transferred from the photosensitive drum to the transfer material on the transfer drum, and similarly, the second to fourth color toner images are transferred onto the transfer material on the transfer drum. The transfer material having the image is separated from the transfer drum, conveyed to a heat and pressure fixing unit, and fixed to form a full-color or multicolor image on the transfer material.

In a full-color or multi-color image forming method, a plurality of color toner images are stacked on a transfer material and fixed by heating and pressing. Is easy to occur.

Conventionally, a method of adding a wax such as a low-molecular-weight polyolefin to toner particles has been proposed from the viewpoint of giving the toner itself good fixability and offset resistance. For example, JP-B-52-3304, JP-B-52-3305, and JP-B-57-525.
74, JP-A-58-215659, JP-A-60-217366, and JP-A-60-252361.
JP, JP-A-62-14166, JP-A-1-1-1
No. 09359, JP-A-2-79860 and JP-A-3-50559.

As one of the wax components having relatively good fixing properties, there has been proposed a toner having a montan wax as a mineral wax in toner particles.

The montan wax has the following structural formula

[0010]

Embedded image [Wherein, R represents a hydrocarbon group having 28 to 32 carbon atoms, and n represents an integer. The use of a wax component having a molecular weight of about 800 has been proposed in JP-A-1-185660 and JP-A-1-238672.

However, the montan-based wax has a linear structure, has a high plasticity effect, and softens the toner. Therefore, although the low-temperature fixing property is improved to some extent, the high-temperature offset resistance is reduced. The plasticized toner tends to cause problems in developing characteristics, durability, and blocking resistance.

Japanese Patent Application Laid-Open No. 4-184350 discloses a toner containing a polyglycerin partial ester compound. Polyglycerin has, for example, the following formula:

[0013]

Embedded image [In the formula, n represents an integer of 1 or more. ] Is shown. The polyglycerin partial ester compound is a compound of the polyglycerin O
This is an ester compound in which the H group remains. That is,
The polyglycerin partial ester compound does not substantially contain a compound in which all OH groups of polyglycerin are esterified. The polyglycerin partial ester compound has an increased affinity for paper due to residual OH groups, but tends to cause a reduction in triboelectric charging characteristics and a decrease in resolution of the toner in a high-temperature and high-humidity environment. Further, when toner particles are directly produced from the polymerizable monomer composition in an aqueous medium, the polymerizable monomer composition containing the polyglycerin partial ester compound has the polyglycerin partial ester compound. Granulation in an aqueous medium is difficult due to residual OH groups, and the particle size distribution of the generated toner particles tends to be wide.

Japanese Patent Publication No. 36-10231 proposes a toner produced by a suspension polymerization method. In the suspension polymerization method, a polymerizable monomer and a colorant (and, if necessary, a polymerization initiator, a crosslinking agent, a charge control agent, a wax and other additives) are uniformly dissolved or dispersed to form a polymerizable monomer. After preparing the body composition, the polymerizable monomer composition is dispersed in an aqueous medium containing a dispersion stabilizer using an appropriate stirrer, granulated, and allowed to undergo a polymerization reaction to obtain a desired particle size. Is generated.

In the suspension polymerization method, since a droplet of the polymerizable monomer composition is formed in a dispersion medium having a large polarity such as water, a component having a polar group contained in the polymerizable monomer composition is used. Is easily present in the surface layer at the interface with the aqueous medium, and the nonpolar component can form a core / shell structure existing inside.

The toner particles directly produced by the polymerization method can achieve the contradictory performances of low-temperature fixing property, blocking resistance and high-temperature offset resistance by incorporating a wax component as a release agent. In addition, high-temperature offset can be prevented without applying a release agent such as oil to the fixing roller. Therefore, even when toner particles are formed by a polymerization method, an ester wax capable of forming good toner particles has been desired.

[0017]

SUMMARY OF THE INVENTION It is an object of the present invention to greatly improve the disadvantages of the prior art, to achieve excellent long-term storage stability, to realize a high-quality image, and to realize a photosensitive member and a toner carrier. Further, the present invention provides a dry toner which is highly applicable to an electrophotographic process which does not adversely affect an intermediate transfer member and the like, and an image forming method using the toner.

[0018]

The present invention relates to a dry toner having toner particles containing at least a binder resin, a colorant and a wax component, wherein the content of the wax component is 100 parts by mass of the binder resin. 1 to 30 parts by mass, and at least an ester compound represented by the following formula (A) or (B) or a mixture thereof is 50 to 100 parts by mass.
The present invention relates to a dry toner characterized in that the toner is contained by mass% (based on the mass of the wax component).

[0019]

Embedded image

The present invention further provides at least a charging step of applying a voltage to a charging member from the outside to charge the electrostatic latent image carrier; and forming an electrostatic latent image on the charged electrostatic latent image carrier. Forming a latent image by developing the electrostatic latent image with the toner carried on the toner carrier and forming a toner image on the electrostatic latent image carrier; toner on the electrostatic latent image carrier An image forming method comprising: a transfer step of transferring an image to a transfer material with or without an intermediate transfer member; and a fixing step of heating and fixing the toner image on the transfer material, wherein the dry toner having the above-described configuration is used as the toner. The present invention relates to an image forming method characterized by using.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION The toner of the present invention contains a wax component in toner particles in an amount of 1 to 3 parts by weight based on 100 parts by weight of a binder resin.
0 parts by mass, and the wax component contains at least 50 to 100% by mass (based on the mass of the wax component) of a wax compound represented by the following formula (A) or (B) or a mixture thereof.

[0022]

Embedded image

The ester compound represented by the above formula (A) can be produced by reacting trimellitic acid (benzene-1,2,4-tricarboxylic acid) with an alcohol component. In the ester compound represented by the formula (A), no carboxyl group derived from trimellitic acid remains.

The ester compound represented by the formula (B) can be produced by reacting pyromellitic acid (benzene-1,2,4,5-tetracarboxylic acid) with an alcohol component. In the ester compound represented by the formula (B), no carboxyl group derived from pyromellitic acid remains.

The toner of the present invention contains 1 to 30 parts by mass of a wax component based on 100 parts by mass of a binder resin, and the wax component contains an ester compound represented by the above formula (A) or (B). Or a mixture thereof is contained in an amount of 50 to 100% by mass, preferably 70 to 100% by mass, more preferably 90 to 100% by mass (all based on the mass of the wax component). In this case, the long-term storage stability of the toner becomes good, and the low-temperature fixability and the offset resistance are also improved.

The above ester compound according to the present invention can obtain a polyfunctional ester wax having an appropriate polarity and a branched structure by using an aromatic polycarboxylic acid as the central skeleton. This prevents the toner particles from changing over time due to the addition of the wax component, and provides good long-term stability. Further, since plasticization of the toner particles is minimized, low-temperature fixability and offset resistance are improved, and developability and matching with the image forming apparatus are improved.

R _{1 to} R ₇ of the ester compound represented by the above formula (A) or (B) are an organic group having 10 to 40 carbon atoms, more preferably 10 to 40 carbon atoms, further preferably An alkyl group or alkenyl group having 14 to 40 carbon atoms is preferred, and a linear alkyl group having 16 to 30 carbon atoms is most preferred.

By setting the carbon number of R _{1 to} R ₇ to 10 to 40, an appropriate strength can be imparted to the toner particles, and the developability and matching with the image forming apparatus become extremely good. Further, such a branched wax having an organic group improves the dispersibility of the constituent components in other toner particles, so that the developing property and the transfer property are particularly improved.

The carbon number of R _{1 to} R ₇ is determined by GC-MS or FD-
It can be determined by mass spectrometry such as MS or instrumental analysis such as ¹³ C-NMR. Further, if necessary, the wax component may be hydrolyzed by an autoclave method, an enzymatic method, or the Witschl method, and the resulting alcohol component may be measured by instrumental analysis as described above to determine the carbon number.

On the other hand, the acid value of the wax component according to the present invention is 10 mgKOH / g or less, and more preferably 0.1 to 0.1 mgKOH / g.
It is adjusted to the range of 5.0 mgKOH / g.

When a large amount of the trimellitic acid or pyromellitic acid partial ester compound is present in the wax component, the acid value of the wax component increases due to the carboxyl group of the partial ester compound. In the present invention, by specifying the acid value of the wax component, the branched state and the polarity of the wax component are made preferable, and the incorporation of the partial ester compound can be suppressed. As the acid value of the wax component exceeds 10 mgKOH / g, the abundance of the partial ester compound increases, so that not only the long-term stability of the toner is impaired, but also the triboelectric charging characteristics and fluidity of the toner under high temperature and high humidity. And the reproducibility of the image decreases. In particular, when a toner is produced by a polymerization method, the above-mentioned problem becomes remarkable because the partial ester compound acts as a surfactant on the toner particles and easily remains on the toner surface.

Since the ester compound according to the present invention is produced by an ester equilibrium reaction as shown in the following (formula 1) and (formula 2), the yield of the ester compound can be reduced by adding an alcohol component in excess. However, when the acid value of the produced ester compound is less than 0.1 mgKOH / g, unreacted alcohol is mixed. The alcohol component used in the present invention has 10 to 40 carbon atoms, and it is very difficult to separate it from the produced ester compound. When the ester compound is used in a state where the alcohol component is mixed as described above, not only the developing property of the toner is lowered but also a problem may occur in matching with the image forming apparatus, which is not preferable.

In the present invention, the acid value of the wax component is
The Japan Oil Chemistry Association, “Standard Oil and Fat Analysis Test Method” (1983)
Use the value measured according to the wax analysis method in (Year). Specifically, 5 to 10 g of a measurement sample is weighed,
This is added to 50 ml of xylene and dissolved by heating. To this is added 20 to 30 ml of neutral ethanol, and hot titration is performed in a state where no sample is precipitated, thereby obtaining a value.

As the method for producing the aromatic polycarboxylic acid ester used in the present invention, various conventionally known methods can be used. However, trimellitic acid is used as an acid component because of the variety of raw materials and the ease of reaction. And / or a method utilizing a dehydration condensation reaction from pyromellitic acid and a higher alcohol having 10 to 40 carbon atoms as an alcohol component (formula 1), or a halide of trimellitic acid and / or pyromellitic acid and the alcohol component (Formula 2) is particularly preferred.

[0035]

Embedded image

In order to transfer the above-mentioned ester equilibrium reaction to the production system, a large excess of an alcohol component is used or Dean-Star in an aromatic organic solvent capable of azeotropic distillation with water.
The reaction is performed using a k-water separator. Further, a method of synthesizing an ester by adding a base as an acceptor of an acid produced as a by-product in an aromatic organic solvent using the acid halide compound can also be used.

However, no matter which production method is used, the acid value of the wax component according to the present invention must be adjusted so as to be 10 mgKOH / g or less.

Other components that can be used together with the above ester compound as the wax component according to the present invention include, for example, petroleum waxes such as paraffin wax, microcrystalline wax, petrolactam and derivatives thereof, montan wax and Derivatives thereof, Fischer-Tropsch hydrocarbon wax and derivatives thereof,
Polyolefin wax represented by polyethylene and derivatives thereof, carnauba wax, natural waxes such as candelilla wax and derivatives thereof, and the like.Derivatives include oxides, block copolymers with vinyl monomers, and graft-modified products. included. In addition, alcohols such as higher aliphatic alcohols; fatty acids such as stearic acid and palmitic acid or compounds thereof; acid amides, esters, ketones, hydrogenated castor oil and derivatives thereof, vegetable waxes, and animal waxes. These can be used alone or in combination.

Among them, when polyolefin, hydrocarbon wax by Fischer-Tropsch method, petroleum wax, higher alcohol or higher ester is used, the effect of improving developability and transferability is further enhanced. Note that an antioxidant may be added to these wax components as long as the chargeability of the toner is not affected.

These wax components are used as binder resin 100
It is used in the range of 1 to 30 parts by mass with respect to parts by mass.

When the content of the wax component is less than 1 part by mass, the effect of the addition is not exhibited. On the other hand, when the amount exceeds 30 parts by mass, it is difficult to include the toner particles in the toner particles, which causes problems such as deterioration of the toner and contamination of the image forming apparatus. Further, when a toner is produced by a polymerization method, the above-described problem becomes significant because it also affects the shape control of the toner.

Further, the toner according to the present invention has a circle-equivalent number average diameter D ₁ (μm) of 2 in a circle-equivalent diameter-circularity scattergram based on the number of toners measured by a flow type particle image measuring apparatus. -10 μm, the average circularity of the toner is 0.920 to 0.995, and the standard deviation of the circularity is less than 0.040. And the transferability are improved in a well-balanced manner, and the matching with the image forming apparatus is significantly improved.

By reducing the toner-equivalent number average diameter D ₁ (μm) of the toner to 2 to 10 μm, the reproducibility of the contour portion of the image, particularly the development of a character image or a line pattern, is improved. Become. However, in general, when the particle size of the toner particles is reduced, the abundance ratio of the fine particles is necessarily increased, so that it is difficult to uniformly charge the toner, and not only image fog occurs but also the surface of the electrostatic latent image carrier And the adhesion to the toner carrier is increased, resulting in an increase in transfer residual toner and the above-described problems.

On the other hand, the toner of the present invention has a circularity standard deviation of less than 0.040, preferably less than 0.035,
More preferably, it is 0.015 or more and less than 0.035, so that the problem relating to the developability can be significantly improved. The reason is that when forming a thin layer of toner on the toner carrier in the developing step, the present inventors have found that even if the regulating force of the toner layer regulating member is made stronger than usual, the branching structure or branching of the wax component may be caused. Since the toner particles have an appropriate strength by specifying the chain length, damage such as grinding of the toner surface and burying of external additives received from the toner layer regulating member and the toner carrier is minimized, and sufficient toner is provided. It is considered that the amount of coating can be maintained, so that the toner charge amount on the toner carrier can be made appropriate.

The average circularity of the circularity frequency distribution of the toner is 0.920 to 0.995, preferably 0.950 to 0.950.
By setting the ratio to 0.995, more preferably 0.970 to 0.990, the transferability of a toner having a small particle diameter, which has been difficult in the past, is greatly improved, and the developing ability for a low potential latent image is also improved. Dramatically improved. In particular, the above tendency is very effective when developing a digital minute spot latent image or when forming a full-color image in which an intermediate transfer body is used to perform multiple transfers, and the matching with the image forming apparatus is also good. It becomes something.

The circle equivalent diameter, circularity, and frequency distribution of the toner used in the present invention are used as a simple method for quantitatively expressing the shape of the toner particles. Equipment "FPIA-1000"
(Manufactured by Toa Medical Electronics Co., Ltd.) and calculated using the following equation.

[0047]

(Equation 1)

Here, the “particle projection area” is the area of the binarized toner particle image, and the “perimeter of the particle projection image”
Is defined as the length of the contour obtained by connecting the edge points of the toner particle image.

The circularity in the present invention is an index indicating the degree of unevenness of the toner. The circularity is 1.000 when the toner is perfectly spherical, and the circularity becomes smaller as the surface shape becomes more complicated.

In the present invention, the circle-equivalent number average diameter D ₁ (μ
m) and the particle size standard deviation SDd are calculated from the following equation, where di is the particle size (center value) at the dividing point i of the particle size distribution, and f _i is the frequency.

[0051]

(Equation 2)

[0052]

[0053]

(Equation 3)

As a specific measuring method, 10 ml of ion-exchanged water from which impurity solids and the like have been removed in advance is prepared in a container, and a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersing agent thereto. Further, 0.02 g of the measurement sample is added and uniformly dispersed. As a means for dispersing, an ultrasonic disperser “UH-50 type” (manufactured by SMT Corporation) equipped with a titanium alloy chip of 5φ as a vibrator is used, and a dispersion treatment for 5 minutes is performed. I do. At this time, the dispersion is appropriately cooled so that the temperature of the dispersion does not become 40 ° C. or higher.

For the measurement of the shape of the toner, the above-mentioned flow type particle image measuring device was used.
The concentration of the dispersion is readjusted so as to be about 10,000 / μl, and 1,000 or more toner particles are measured. After the measurement, using this data, the equivalent circle diameter and circularity frequency distribution of the toner are obtained.

The wax component according to the present invention is obtained by observing a tomographic surface of a toner using a transmission electron microscope (TEM).
It is preferable that the wax component is substantially spherical and / or spindle-shaped and dispersed in an island shape without being compatible with the binder resin.

In the present invention, the dispersion state of the wax component as described above is defined as follows. In other words, the circle-equivalent weight average diameter D means the average value of the weight-based particle size frequency distribution of the toner measured by the above-mentioned flow type particle image measuring apparatus.
₄ (μm), D ₄ × 0.9 or more, and D ₄ × 1.
20 tomographic planes of toner having a major axis of 1 or less are selected. Then, the major axis R of the tomographic plane of each selected toner,
Among the phase separation structures caused by the wax component existing in the tomographic plane of the toner having the major diameter R, the largest major axis r is measured, and the arithmetic mean value of r / R (r / R) _st is _calculated . Ask. The arithmetic mean value (r / R) _{st of the} obtained r / R is 0.0
When the wax component is in a dispersion state satisfying 5 ≦ (r / R) _st ≦ 0.95, the wax component has a substantially spherical and / or spindle-shaped island dispersion state in a state in which the wax component is not compatible with the binder resin. It is assumed that

By dispersing the wax component as described above and encapsulating it in the toner particles, it is possible to prevent deterioration of the toner and contamination of the image forming apparatus. In particular, r
/ R arithmetic mean value (r / R) _st is 0.25 ≦ (r / R
R) The dispersion state satisfying _st ≦ 0.90 is preferable because good chargeability is maintained and a toner image excellent in dot reproduction can be formed for a long period of time. In addition, since the wax component acts efficiently at the time of heating, the low-temperature fixability and the offset resistance are also good.

As a method of observing the tomographic plane of the toner,
An electron dyeing method that uses the difference in the microstructure between the crystalline phase and the amorphous phase of the wax component to be used and the binder resin that forms the outer periphery to increase the electron density of one component with heavy metal to give a contrast between the materials. It is preferable to use Specifically, after sufficiently dispersing the toner particles in a room temperature curable epoxy resin, the toner particles are cured for 2 days at an ambient temperature of 40 ° C., and the obtained cured product is ruthenium tetroxide (Ru).
O ₄ ) and, if necessary, osmium tetroxide (OsO ₄ )
And then performing electron staining, a flaky sample is cut out using an ultramicrotome equipped with a diamond knife, and the sectional layer morphology of the toner is observed using a transmission electron microscope (TEM).

FIG. 7 shows a typical example. In the toner particles obtained in Examples described later, it was observed that the wax component was encapsulated in the outer shell resin.

Examples of the binder resin used in the toner of the present invention include commonly used styrene- (meth) acrylic copolymers, polyester resins, epoxy resins, and styrene-butadiene copolymers. In a method of directly obtaining toner particles by a polymerization method, a monomer for forming them is used. Specifically, styrene; o
Styrene-based monomers such as (m-, p-)-methylstyrene and m (p-)-ethylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth) ) Butyl acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth)
(Meth) acrylate monomers such as dimethylaminoethyl acrylate and diethylaminoethyl (meth) acrylate; ene monomers such as butadiene, isoprene, cyclohexene, (meth) acrylonitrile, and acrylamide are preferably used. Can be These can be used alone or generally in the published Polymer Handbook, 2nd Edition, III-P 139-192 (John Wiley).
& Sons Corporation) theoretical glass transition temperature (Tg)
However, it is used by appropriately mixing monomers so as to show a temperature of 40 to 75 ° C. If the theoretical glass transition temperature is lower than 40 ° C., problems tend to occur in terms of the storage stability and durability stability of the toner, while if it exceeds 75 ° C., the fixing point of the toner increases. In particular, in the case of a color toner for forming a full-color image, it is not preferable because the color mixing property of each color toner at the time of fixing is lowered and color reproducibility is poor, and further the transparency of the OHP image is lowered.

The molecular weight of the binder resin is measured by gel permeation chromatography (GPC). In the case of a toner having a core-shell structure, specific GPC
The method of measurement is to extract the toner in advance using a Soxhlet extractor with a toluene solvent for 20 hours and then distill off the toluene with a rotary evaporator to obtain an extract. An organic solvent that does not dissolve the resin (for example, chloroform or the like) is added to the extract, washed sufficiently, and the residue is washed with tetrahydrofuran (TH
Sample (THF solution) obtained by filtering the solution dissolved in F) through a solvent-resistant membrane filter having a pore diameter of 0.3 μm.
Is measured using Waters 150C. The column configuration is A-801, 802, 803, 80 manufactured by Showa Denko
4, 805, 806, 807 can be linked and the molecular weight distribution can be measured using a standard polystyrene resin calibration curve. The main peak molecular weight of the resin component of the obtained polymer particles was 5,000.
Those having a weight average molecular weight (Mw) and a number average molecular weight (Mn) ratio (Mw / Mn) of 2 to 100 are preferable in the present invention.

In the present invention, it is particularly preferable to further add a polar resin in order to encapsulate the wax component in the outer shell. As the polar resin used in the present invention, a copolymer of styrene and (meth) acrylic acid, a maleic acid copolymer, an unsaturated polyester resin, a saturated polyester resin or an epoxy resin is preferably used.

The coloring agents used in the present invention include the following yellow coloring agents, magenta coloring agents and cyan coloring agents. As black coloring agents, carbon black, magnetic substances or the following yellow coloring agents / magenta coloring agents / A mixture of a cyan colorant and a black color is used.

Examples of the yellow colorant include condensed azo compounds, isoindolinone compounds, anthraquinone compounds,
Compounds represented by azo metal complexes, methine compounds and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 6
2, 74, 83, 93, 94, 95, 109, 110,
111, 128, 129, 147, 168, 180 and the like are preferably used.

Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds. Specifically, C.I.
I. Pigment Red 2, 3, 5, 6, 7, 23, 4
8; 2, 48; 3, 48; 4, 57; 1, 81; 1, 1
44, 146, 166, 169, 177, 184, 18
5, 202, 206, 220, 221, 254 are particularly preferred.

As the cyan coloring agent, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds and the like can be used. Specifically, C.I. I.
Pigment Blue 1, 7, 15, 15: 1, 15: 2,
15: 3, 15: 4, 60, 62, 66, etc. can be particularly preferably used.

These colorants can be used alone or as a mixture or in the form of a solid solution. The colorant has a hue,
It is selected from the viewpoints of chroma, lightness, weather resistance, OHP transparency, and dispersibility in toner particles. The amount of the colorant to be added is preferably 1 to 20 parts by mass with respect to 100 parts by mass of the resin component.

When a magnetic material is used as a black colorant, unlike other colorants, 40 parts per 100 parts by mass of resin is used.
It is preferable to use 150 parts by mass.

The charge control agent used in the present invention includes:
Known charge control agents can be used, and in particular, a charge control agent which has a high charge speed and can stably maintain a constant charge amount is preferable. Further, when the toner particles are directly polymerized, a charge control agent having no polymerization inhibition and having no solubilized substance in an aqueous dispersion medium is particularly preferable. Specific examples of the compound include a metal compound of an aromatic carboxylic acid such as salicylic acid, naphthoic acid, and dicarboxylic acid as a negative charge control agent; a polymer compound having a sulfonic acid or carboxylic acid group in a side chain; an azo metal compound A boron compound; a urea compound; a silicon compound; Examples of the positive charge control agent include a quaternary ammonium salt; a polymer compound having the quaternary ammonium salt in a side chain; a guanidine compound; and an imidazole compound. The charge control agent is preferably used in an amount of 0.5 to 10 parts by mass based on 100 parts by mass of the resin. However, in the present invention, the addition of a charge control agent is not essential, and in the case of using a two-component developing method, utilizing triboelectric charging with a carrier, and in the case of using a non-magnetic one-component blade coating developing method, By positively utilizing frictional charging with the blade member and the sleeve member, it is not always necessary to include a charge control agent in the toner particles.

The method for producing the toner of the present invention includes the following:
After uniformly dispersing the resin, wax component, colorant, charge control agent, etc. using a pressure kneader, extruder or media disperser, the resin is made to collide with the target mechanically or under a jet stream to obtain a desired toner particle size. After pulverization (additional steps of smoothing and spheronizing toner particles are added as necessary), a classification process is further performed to sharpen the particle size distribution to obtain a toner. JP-B-56-13945 discloses a method of atomizing a molten mixture into air using a disk or a multi-fluid nozzle to obtain a spherical toner, and JP-B-36-10231, JP-A-59-53856 and JP-A-59-53856. Kaisho 59-61
No. 842, a method of directly producing a toner using a suspension polymerization method, and a method of producing a toner directly using an aqueous organic solvent in which a polymer obtained is soluble in a monomer and insoluble in a polymer. The toner can be produced by a method or an emulsion polymerization method typified by a soap-free polymerization method in which a toner is produced by directly polymerizing in the presence of a water-soluble polar polymerization initiator.

When the toner is produced by the pulverization method, it is difficult to keep the circularity frequency distribution of the toner within a desired range. In the melt spraying method, the average circularity is 0.9.
Even if the particle size can be adjusted to 20 to 0.995, the particle size distribution of the obtained toner tends to be wide. On the other hand, in the dispersion polymerization method, the obtained toner has an extremely sharp particle size distribution, but the production equipment is not suitable from the viewpoints of narrow selection of materials to be used and utilization of organic solvents in terms of treatment of waste solvents and flammability of solvents. It is complicated and easy to be complicated. Emulsion polymerization methods represented by soap-free polymerization are effective because the particle size distribution of the toner is relatively uniform, but when the used emulsifier or polymerization initiator terminal is present on the surface of the toner particles, the environmental characteristics tend to deteriorate.

In the present invention, an emulsion polymerization method or a suspension polymerization method under normal pressure or under pressure can control the circularity frequency distribution of the toner within a desired range and relatively easily obtain a fine particle toner having a sharp particle size distribution. A method in which the obtained polymer is shaped into a medium using a medium, or the polymer is caused to directly collide with a pressure impingement plate, and furthermore, the obtained polymer is frozen in an aqueous system, or is subjected to salt break or opposite surface. An aggregation method of uniting, aggregating, and coalescing charged particles in consideration of conditions such as pH is particularly preferable. Further, a seed polymerization method in which a monomer is further adsorbed on the polymer particles once obtained and then polymerized using a polymerization initiator can also be suitably used in the present invention.

When a direct polymerization method is used as a method for producing a toner, the particle size distribution and the particle shape of the toner particles are controlled by changing the type and amount of a poorly water-soluble inorganic salt or a dispersant acting as a protective colloid. The desired toner particles can be obtained by controlling the mechanical conditions (eg, the peripheral speed of the rotor, the number of passes, the stirring conditions such as the shape of the stirring blade and the shape of the container), or the solid content concentration in the aqueous solution. .

When the toner is produced by the direct polymerization method, for example, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile,
Azo-based or diazo-based polymerization initiators such as azobisisobutyronitrile; peroxide-based polymerization initiators such as benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide and lauroyl peroxide Is used. The amount of the polymerization initiator varies depending on the desired degree of polymerization, but is generally used in an amount of 0.5 to 20% by mass based on the polymerizable monomer. The type of the polymerization initiator varies slightly depending on the polymerization method, but is used alone or in combination with reference to the 10-hour half-life temperature.

For controlling the degree of polymerization, known crosslinking agents, chain transfer agents, polymerization inhibitors and the like may be further added.

When a suspension polymerization method using a dispersion stabilizer is used as a method for producing a toner, the dispersion stabilizer to be used is:
As inorganic compounds, tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite , Silica, alumina and the like. As organic compounds,
Polyvinyl alcohol, gelatin, methylcellulose,
Examples include methylhydroxypropylcellulose, ethylcellulose, sodium salts of carboxymethylcellulose, polyacrylic acid and its salts, starch and the like. These can be used by dispersing them in an aqueous phase. It is preferable to use 0.2 to 20 parts by mass of these dispersion stabilizers with respect to 100 parts by mass of the polymerizable monomer.

When an inorganic compound is used as the dispersion stabilizer, a commercially available one may be used as it is, but fine particles of the inorganic compound may be produced in a dispersion medium in order to obtain fine particles. For example, in the case of tricalcium phosphate,
It is preferable to mix an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring.

For fine dispersion of these dispersion stabilizers,
0.001 to 0.1 parts by mass of a surfactant may be used in combination. This is to promote the intended action of the dispersion stabilizer, for example, sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate. ,
And calcium oleate.

When a direct polymerization method is used as a method for producing the toner used in the present invention, the following production methods are possible.

A monomer composition obtained by adding a wax component, a colorant, a charge control agent, a polymerization initiator, and other additives to a polymerizable monomer and uniformly dissolving or dispersing the mixture using a homogenizer, an ultrasonic disperser, or the like. The product is dispersed in an aqueous phase containing a dispersion stabilizer using a conventional stirrer, homomixer, homogenizer or the like. Preferably, the granulation is performed by adjusting the stirring speed and the stirring time so that the droplets of the monomer composition have the desired size of the toner particles. Thereafter, by the action of the dispersion stabilizer, the particles may be stirred to such an extent that the particle state is maintained and the particles are prevented from settling. Polymerization temperature is 40 ° C
As described above, it is generally preferable to carry out polymerization at a temperature of 50 to 90 ° C. The temperature may be raised in the latter half of the polymerization reaction.
For the purpose of improving the durability in the image forming method of the present invention, in order to remove unreacted polymerizable monomers, by-products, etc., in the latter half of the reaction, or after the reaction, a part of the aqueous medium is distilled off from the reaction system. You may. After completion of the reaction, the generated toner particles are collected by washing and filtration, and dried. In the suspension polymerization method, 30 parts of water is usually added to 100 parts by mass of the monomer composition.
It is preferable to use 0 to 3000 parts by mass as the dispersion medium.

Next, an image forming method to which the toner of the present invention is applied will be described below with reference to the accompanying drawings.

In the apparatus system shown in FIG. 1, the developing units 4-1, 4-2, 4-3, and 4-4 respectively include a developer having a cyan toner and a developer having a magenta toner.
A developer having a yellow toner and a developer having a black toner are introduced, and an electrostatic charge image formed on an electrostatic latent image carrier (for example, a photosensitive drum) 1 by a magnetic brush developing method or a non-magnetic one-component method is used. After development, toner images of each color are formed on the photosensitive drum 1.

The toner of the present invention can be mixed with a magnetic carrier and developed using, for example, a developing means as shown in FIG. Specifically, it is preferable to perform development in a state where the magnetic brush is in contact with the photosensitive drum 13 while applying an alternating electric field. Developer carrier (development sleeve) 1
The distance (distance between S-D) B between 1 and the photosensitive drum 13 is 10
A thickness of 0 to 1000 μm is favorable in preventing carrier adhesion and improving dot reproducibility. If it is smaller than 100 μm, the supply of the developer tends to be insufficient and the image density is reduced. If it is larger than 1000 μm, the magnetic field lines from the magnet S1 are widened and the density of the magnetic brush is reduced, resulting in poor dot reproducibility or restrained carrier. And the carrier is likely to adhere.

The voltage (Vpp) between the peaks of the alternating electric field is 5
00 to 5000 V is preferable, and the frequency (f) is 500 to
It is 10,000 Hz, preferably 500 to 3000 Hz, and each can be appropriately selected and used for the process. In this case, the waveforms are triangular, rectangular, sine,
Alternatively, various types of waveforms such as a waveform with a changed duty ratio can be used. If the applied voltage is lower than 500 V, it is difficult to obtain a sufficient image density, and it may not be possible to satisfactorily collect fog toner in the non-image area. 5000
If the voltage exceeds 0 V, the electrostatic image may be disturbed via the magnetic brush, and the image quality may be degraded.

By using a two-component developer having a well-charged toner, the fog removal voltage (Vback)
And the primary charge of the photoconductor can be reduced, so that the life of the photoconductor can be extended. Vbac
k is preferably 150 V or less, more preferably 100 V or less, depending on the developing system.

The contrast potential is preferably from 200 V to 500 V so that a sufficient image density can be obtained.

When the frequency is lower than 500 Hz, although it depends on the process speed, the charge may be injected into the carrier, so that the image quality may be deteriorated due to the adhesion of the carrier or the disturbance of the latent image. If the frequency exceeds 10,000 Hz, the toner cannot follow the electric field, and the image quality is likely to deteriorate.

In order to obtain a sufficient image density, achieve excellent dot reproducibility, and perform development without carrier adhesion, the contact width (developing nip C) of the magnetic brush on the developing sleeve 11 with the photosensitive drum 13 is preferably set. 3 to 8 mm. If the developing nip C is narrower than 3 mm, it is difficult to sufficiently satisfy a sufficient image density and dot reproducibility.
When the width is larger than mm, packing of the developer occurs to stop the operation of the machine, and it is difficult to sufficiently suppress carrier adhesion. As a method of adjusting the development nip,
The nip width is appropriately adjusted by adjusting the distance A between the developer regulating member 18 and the developing sleeve 11 or adjusting the distance B between the developing sleeve 11 and the photosensitive drum 13.

In the output of a full-color image in which halftone is particularly important, three or more developing devices for magenta, cyan, and yellow are used, and the developer and the developing method of the present invention are used. By combining with a developing system that forms a latent image, it is possible to develop the dot latent image faithfully without being affected by the magnetic brush and disturbing the latent image. In the transfer step, a high transfer rate can be achieved by using the toner of the present invention, so that high image quality can be achieved in both the halftone portion and the solid portion.

Further, by using the toner of the present invention together with the initial improvement of image quality, the effect of the present invention without image quality deterioration can be sufficiently exerted even when copying a large number of sheets.

The toner of the present invention can be suitably used for one-component development. An example of an apparatus for developing an electrostatic image formed on an electrostatic latent image carrier is shown, but the invention is not necessarily limited thereto.

In FIG. 3, a latent image is formed on an electrostatic latent image carrier (photosensitive drum) 25 by an electrophotographic process means or an electrostatic recording means. The toner carrier 24 (developing sleeve) is a non-magnetic sleeve made of aluminum or stainless steel.

The substantially right half peripheral surface of the developing sleeve 24 is always in contact with the toner reservoir in the toner container 21, and the toner near the developing sleeve surface is brought into contact with the developing sleeve surface by the magnetic force of the magnetic generating means in the sleeve. Adhered and held by electrostatic force.

In the present invention, the surface roughness Ra of the toner carrier is
(Μm) is set to 1.5 or less. Preferably it is 1.0 or less. More preferably, it is 0.5 or less.

By controlling the surface roughness Ra to 1.5 or less, the ability of the toner carrier to transport toner particles is suppressed.
Since the toner layer on the toner carrier is made thinner and the number of times of contact between the toner carrier and the toner is increased, the chargeability of the toner is also improved, so that the image quality is synergistically improved.

If the surface roughness Ra of the toner carrier exceeds 1.5, it becomes difficult not only to reduce the thickness of the toner layer on the toner carrier, but also to improve the image quality since the chargeability of the toner is not improved. Can not hope.

In the present invention, the surface roughness Ra of the toner carrier is determined by using a surface roughness measuring device (Surfcoder SE-30H, manufactured by Kosaka Laboratory Co., Ltd.) based on JIS surface roughness "JISB 0601". Corresponds to the center line average roughness measured. Specifically, a 2.5 mm portion is extracted from the roughness curve in the direction of the center line as the measurement length a,
The center line of the extracted portion is the X axis, and the direction of the vertical magnification is Y.
When an axis and a roughness curve are represented by y = f (x), a value obtained by the following equation is represented by a micrometer (μm).

[0099]

(Equation 4)

As the toner carrier used in the present invention, a cylindrical or belt-like member made of, for example, stainless steel, aluminum or the like is preferably used. If necessary, the surface may be coated with metal, resin, etc.
A resin in which fine particles such as a resin, metals, carbon black, and a charge controlling agent are dispersed may be coated.

In the present invention, the surface moving speed of the toner carrier is set to be 1.05 to 3 times the surface moving speed of the electrostatic latent image carrier.
By setting it to be 0 times, the toner layer on the toner carrier receives an appropriate stirring effect, so that the faithful reproduction of the electrostatic latent image is further improved.

If the surface moving speed of the toner carrier is less than 1.05 times the surface moving speed of the electrostatic latent image carrier, the stirring effect received by the toner layer becomes insufficient, resulting in good image formation. Can not hope. Further, when developing an image requiring a large amount of toner over a wide area, such as a solid black image, the amount of toner supplied to the electrostatic latent image is insufficient, and the image density is reduced. On the other hand, when it exceeds 3.0, in addition to the various problems caused by excessive charging of the toner as described above,
Deterioration of the toner due to mechanical stress and sticking of the toner to the toner carrier occur and are promoted, which is not preferable.

The toner T is stored in the hopper 21 and supplied by the supply member 22 onto the developing sleeve. As the supply member, a supply roller made of a porous material such as a foamed material such as a flexible polyurethane foam is preferably used. The supply roller is rotated with respect to the developing sleeve in a forward or reverse direction at a non-zero relative speed, so that the toner is supplied to the developing sleeve and the toner after development (undeveloped toner) on the sleeve is also removed. At this time, the contact width of the supply roller to the developing sleeve is preferably 2.0 to 10.0 mm in consideration of the balance between toner supply and stripping, and 4.0 to 6.0 mm.
mm is more preferable. On the other hand, excessive stress is inevitably applied to the toner, and the aggregation of the toner due to the deterioration of the toner is increased, or the fusion and fixation of the toner to the developing sleeve and the supply roller are easily caused. Is excellent in fluidity and releasability, and has durability stability, and therefore is preferably used in a developing method having the supply member. Further, a brush member made of a resin fiber such as nylon or rayon may be used as the supply member. Although these supply members are extremely effective in a one-component developing method using a non-magnetic one-component toner that cannot utilize a magnetic binding force, they may be used in a one-component developing method using a magnetic one-component toner.

The toner supplied onto the developing sleeve is thinly and uniformly applied by the regulating member. The toner thinning regulating member is a doctor blade such as a metal blade or a magnetic blade disposed at a predetermined gap from the developing sleeve. Or, instead of a doctor blade, use metal,
Rigid rollers or sleeves made of resin, ceramic, or the like may be used, and a magnet generating means may be inserted inside them.

An elastic member such as an elastic blade or an elastic roller for press-applying the toner may be used as a regulating member for thinning the toner. For example, in FIG. 3, the elastic blade 23 has a base on the upper side thereof on the side of the developer container 21.
The developing sleeve 24 is flexed in the forward or reverse direction against the elasticity of the blade on the lower side, and the inner surface of the blade (the outer surface in the case of the reverse direction) is the surface of the sleeve 24. To each other with moderate elastic pressure. According to such an apparatus, a dense toner layer that is stable against environmental fluctuations can be obtained. Although the reason is not clear, it is presumed that the elastic body is forcibly rubbed against the surface of the developing sleeve, so that charging is always performed in the same state regardless of a change in behavior due to a change in toner environment.

On the other hand, the toner is apt to be excessively charged and the toner is easily fused to the developing sleeve or the elastic blade. However, the toner used in the present invention is preferable because of its excellent releasability and stable triboelectric charging. Used.

For the elastic body, it is preferable to select a material of a triboelectric series suitable for charging the toner to a desired polarity, and a rubber elastic body such as silicone rubber, urethane rubber and NBR; a synthetic material such as polyethylene terephthalate Resin elastic body: Metal elastic bodies such as stainless steel, steel, and phosphor bronze can be used. Further, a composite thereof may be used.

When durability is required for the elastic body and the toner carrier, it is preferable that the metal elastic body is bonded or coated with resin or rubber so as to hit the sleeve contact portion.

Further, an organic substance or an inorganic substance may be added to the elastic body, may be melted and mixed, or may be dispersed. For example, the chargeability of the toner can be controlled by adding a metal oxide, metal powder, ceramics, carbon allotrope, whisker, inorganic fiber, dye, pigment, surfactant or the like. Particularly, when the elastic body is a molded body such as rubber or resin, fine particles of metal oxide such as silica, alumina, titania, tin oxide, zirconia, and zinc oxide, carbon black, a charge control agent generally used for toner And the like.

Further, by applying a DC electric field and / or an AC electric field to the developing blade as the regulating member, the supply roller as the supplying member, and the brush member, the regulating portion on the developing sleeve due to the action of loosening the toner. In, the uniform thin layer coating property and uniform charging property are further improved,
In the supply portion, the supply / stripping of the toner is performed more smoothly, so that a sufficient image density can be achieved and a high quality image can be obtained.

The contact pressure between the elastic body and the toner carrier is:
The linear pressure in the generatrix direction of the toner carrier is 0.1 kg / m
Above, preferably 0.3 to 25 kg / m, more preferably 0.5 to 12 kg / m is effective. As a result, it is possible to effectively loosen the aggregation of the toner, and it is possible to instantly increase the charge amount of the toner. If the contact pressure is less than 0.1 kg / m, it becomes difficult to apply the toner uniformly, and the charge amount distribution of the toner becomes broad, causing fogging and scattering. On the other hand, if the contact pressure exceeds 25 kg / m, a large pressure is applied to the toner, which is not preferable because the toner is deteriorated or a toner aggregate is generated.
Further, a large torque is required to drive the toner carrier, which is not preferable.

A gap α between the electrostatic latent image carrier and the toner carrier
Is preferably set to 50 to 500 μm, and the gap between the doctor blade and the toner carrier is preferably set to 50 to 400 μm.

It is most preferable that the thickness of the toner layer on the toner carrier is smaller than the gap α between the electrostatic latent image carrier and the toner carrier. Among them, the layer thickness of the toner layer may be restricted to such an extent that a part of the toner layer contacts the electrostatic latent image carrier.

On the other hand, a bias power supply 2
By applying an alternating electric field between the toner carrying member and the electrostatic latent image carrying member, the transfer of the toner from the toner carrying member to the electrostatic latent image carrying member can be facilitated, and a higher quality image can be obtained.
Vpp of the alternating electric field is 100 V or more, preferably 200 to
3000V, more preferably 300-2000V. Further, f is 500 to 5000 Hz, preferably 1000 to 3000 Hz, and more preferably 1500
In this case, a waveform such as a rectangular wave, a sine wave, a sawtooth wave, and a triangular wave can be used as the waveform used in the range of 3000 Hz. Also, asymmetrical AC biases having different positive and reverse voltages and times can be used. It is also preferable to superimpose a DC bias.

The electrostatic latent image carrier 1 is made of a-Se, Cds, Z
A photosensitive drum or a photosensitive belt having a photoconductive insulating material layer such as nO ₂ , OPC, or a-Si. The electrostatic latent image carrier 1 is rotated in the direction of the arrow by a driving device (not shown).

As the electrostatic latent image carrier 1, a photosensitive member having an amorphous silicon photosensitive layer or an organic photosensitive layer is preferably used.

As the organic photosensitive layer, the photosensitive layer contains a charge generating substance and a substance having charge transport performance in the same layer.
It may be a single-layer type or a function-separated type photosensitive layer having a charge transport layer as a component of the charge transport layer. A laminated photosensitive layer having a structure in which a charge generation layer and then a charge transport layer are laminated on a conductive substrate in this order is one of preferred examples.

The binder resin for the organic photosensitive layer is preferably a polycarbonate resin, a polyester resin, or an acrylic resin, particularly having good transferability and cleaning properties, poor cleaning, fusion of toner to a photoreceptor, and filming of external additives. Less likely.

In the charging step, there are a system that is not in contact with the electrostatic latent image carrier 1 using a corona charger, and a contact system that uses a roller or the like, and either system is used. For efficient uniform charging, simplification and low ozone generation, a contact type as shown in FIG. 1 is preferably used.

The charging roller 2 basically has a core 2b at the center and a conductive elastic layer 2a forming the outer periphery thereof. The charging roller 2 is pressed against the surface of the electrostatic latent image carrier 1 with a pressing force, and is driven to rotate as the electrostatic latent image carrier 1 rotates.

The preferable process condition when using the charging roller is that the contact pressure of the roller is 5 to 500 g / cm.
When a DC voltage with an AC voltage superimposed is used, the AC voltage is 0.5 to 5 kVpp and the AC frequency is 50 kVpp.
Hz to 5 kHz, the DC voltage is ± 0.2 to ± 1.5 kV, and when only the DC voltage is used, the DC voltage is ± 0.2 to ± 0.5 kV.
2 to ± 5 kV.

Other charging means include a method using a charging blade and a method using a conductive brush. These contact charging means are effective in that high voltage is not required and generation of ozone is reduced.

The material of the charging roller and the charging blade as the contact charging means is preferably conductive rubber, and a release coating may be provided on the surface thereof. As the release coating, a nylon resin, PVDF (polyvinylidene fluoride), PVDC (polyvinylidene chloride) or the like can be applied.

The toner image on the electrostatic latent image carrier is transferred to the intermediate transfer member 5 to which a voltage (for example, ± 0.1 to ± 5 kV) is applied. The surface of the electrostatic latent image carrier is cleaned by cleaning means 9 having a cleaning blade 8.

The intermediate transfer member 5 is made of a pipe-shaped conductive core metal 5.
b and a medium resistance elastic layer 5a formed on the outer peripheral surface thereof. The metal core 5b may be formed by applying a conductive plating to a plastic pipe.

The medium resistance elastic layer 5a is made of silicone rubber, Teflon rubber, chloroprene rubber, urethane rubber,
EPDM (terpolymer of ethylene propylene diene)
A conductive material such as carbon black, zinc oxide, tin oxide, or silicon carbide is mixed and dispersed in an elastic material such as to adjust the electric resistance (volume resistivity) to a medium resistance of 10 ⁵ to 10 ¹¹ Ω · cm. It is a solid or foamed layer.

The intermediate transfer member 5 is provided in parallel with the electrostatic latent image carrier 1 so as to be in contact with the lower surface of the electrostatic latent image carrier 1. It rotates in the counterclockwise direction of the arrow at the same peripheral speed as.

In the course of passing the toner image of the first color formed and carried on the surface of the electrostatic latent image carrier 1 through the transfer nip where the electrostatic latent image carrier 1 and the intermediate transfer body 5 are in contact with each other, the intermediate transfer is performed. The intermediate transfer is sequentially performed on the outer surface of the intermediate transfer body 5 by the electric field formed in the transfer nip area by the transfer bias applied to the body 5.

If necessary, the surface of the intermediate transfer member 5 is cleaned by the detachable cleaning means 10 after the transfer of the toner image onto the transfer material. When there is a toner image on the intermediate transfer member, the cleaning unit 10 is separated from the surface of the intermediate transfer member so as not to disturb the toner image.

Transfer means is provided in parallel with the intermediate transfer member 5 and is brought into contact with the lower surface of the intermediate transfer member 5, and the transfer means 7 is, for example, a transfer roller or a transfer belt. It rotates clockwise with the same peripheral speed as the arrow. The transfer unit 7 may be disposed so as to directly contact the intermediate transfer member 5, or a belt or the like may be disposed so as to contact between the intermediate transfer member 5 and the transfer unit 7.

In the case of the transfer roller, the basic structure is a core metal 7b at the center and a conductive elastic layer 7a forming the outer periphery thereof.

For the intermediate transfer member and the transfer roller, general materials can be used. By setting the volume resistivity of the elastic layer of the transfer roller smaller than the volume resistivity of the elastic layer of the intermediate transfer body, the voltage applied to the transfer roller can be reduced, and a good toner image can be formed on the transfer material. In addition, it is possible to prevent the transfer material from winding around the intermediate transfer member. In particular, it is particularly preferable that the volume resistivity of the elastic layer of the intermediate transfer member is at least 10 times the volume resistivity of the elastic layer of the transfer roller.

For example, the conductive elastic layer 7b of the transfer roller 7
Is polyurethane, ethylene-propylene-diene terpolymer (EPDM) in which conductive material such as carbon is dispersed
It is made of an elastic material having a volume resistance of about 10 ⁶ to 10 ¹⁰ Ωcm. A bias is applied to the metal core 7a from a constant voltage power supply. The bias conditions are ± 0.2 to ±
10 kV is preferred.

The toner of the present invention has high transfer efficiency in the transfer step, has little transfer residual toner, and is excellent in cleaning properties, so that filming hardly occurs on the electrostatic latent image carrier. Further, even when a multi-sheet durability test is performed, the toner of the present invention has less embedding of the external additive on the surface of the toner particles than the conventional toner, so that good image quality can be maintained for a long time. In particular, it is preferably used in an image forming apparatus having a so-called reuse mechanism that removes transfer residual toner on an electrostatic latent image carrier or an intermediate transfer member by a cleaning unit such as a cleaning blade and reuses the collected transfer residual toner. .

Next, the toner image on the transfer material 6 is fixed by a heat and pressure fixing means. As the heating and pressing fixing means, a heating roller incorporating a heating element such as a halogen heater and a pressing roller of an elastic body pressed against the heating roller with a pressing force as a basic configuration, or a heating roller through a film. A method of heating and fixing (FIGS. 5 and 6) can be cited, but the toner of the present invention is excellent in fixability and anti-offset property, and thus shows good matching with the heat and pressure fixing means as described above.

[0136]

EXAMPLES The present invention will be described below with reference to specific examples, but the present invention is not limited to these examples.

Examples of the ester compound in the wax component used in Examples and Comparative Examples are shown below.

[0138]

Embedded image

[0139]

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[0140]

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[0141]

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[0142]

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Table 1 shows the properties of the wax components used in Examples and Comparative Examples.

[0144]

[Table 1]

(Production Example 1 of Toner) In a two-liter four-necked flask equipped with a high-speed stirrer TK-type homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), 650 g of ion-exchanged water and 0.1 ml of 0.1 ml water were added.
500 g of a 1 mol / liter-Na ₃ PO ₄ aqueous solution was charged, the rotation speed was adjusted to 12,000 rpm, and the mixture was heated to 70 ° C. Here, 1.0 mol / liter-CaCl ₂
70 parts by mass of an aqueous solution was gradually added to prepare an aqueous dispersion medium containing a minute poorly water-soluble dispersant Ca ₃ (PO ₄ ) ₂ .

On the other hand, as dispersoids: 78 parts by mass of styrene monomer 22 parts by mass of 2-ethylhexyl acrylate monomer 0.15 parts by mass of divinylbenzene monomer 6 parts by mass of carbon black Polycarbonate resin (peak molecular weight = 4500) 4 parts by mass-2 parts by mass of an azo-based iron compound-A mixture comprising 6 parts by mass of the wax component <A> in Table 1 was dispersed for 3 hours using an attritor (manufactured by Mitsui Kinzoku Co., Ltd.), and then dispersed in 2, 7 parts by mass of 2′-azobis (2,4-dimethylvaleronitrile) was added to prepare a polymerizable monomer composition.

Next, the polymerizable monomer composition was charged into the aqueous dispersion medium, and the mixture was stirred at 15 ° C. under an N ₂ atmosphere at an internal temperature of 70 ° C. while maintaining the rotation speed of a high-speed stirrer at 12,000 rpm.
After stirring for minutes, the polymerizable monomer composition was granulated. Thereafter, the stirrer was replaced with a paddle stirring blade, the temperature was maintained at the same temperature for 5 hours while stirring at 50 rpm, and the temperature was further raised to 80 ° C. for 10 hours to complete the polymerization.

After completion of the polymerization, the remaining monomers were distilled off under reduced pressure under heating, and then, after cooling, dilute hydrochloric acid was added to dissolve the water-soluble dispersant. After repeating water washing several times,
Using a conical ribbon dryer (manufactured by Okawara Seisakusho), the polymer particles (A) are subjected to sphering treatment and drying treatment of the polymerizable particles under heating and reduced pressure for 6 hours while stirring with a spiral ribbon rotating blade.
I got

100 parts by mass of the polymer particles (A) and hydrophobic oil-treated silica fine powder (BET: 200 m ² / g)
2 parts by mass were dry-mixed with a Henschel mixer (manufactured by Mitsui Kinzoku Co., Ltd.) to obtain the toner (A) of the present invention.

The toner (A) has a circle-equivalent number average diameter of 4.
4 μm, the average circularity in the circularity frequency distribution is 0.9.
85, circularity standard deviation is 0.031, circularity is 0.95
Is less than 2.0% by number. G
The molecular weight distribution by PC was such that the peak molecular weight was 13,000 and M
w / Mn was 16.

(Toner Production Examples 2 to 4) Wax Component <
In place of A>, each of the waxes <B> to <D> shown in Table 1 above was used, and the addition amount of the CaCl ₂ aqueous solution, the set temperature of the conical ribbon dryer, the stirring conditions, and the processing time were changed as described above. After obtaining polymer particles (B) to (D) in the same manner as in Production Example 1 of the toner, the toners (B) to
(D) was prepared.

(Comparative Toner Production Examples 1 and 2) In place of the wax component <A>, the waxes <a> and <b> shown in Table 1 above were used.
And the polymer particles for comparison (a) were prepared in the same manner as in Production Example 1 of the toner except that the amount of the CaCl ₂ aqueous solution added, the set temperature of the conical ribbon dryer, the stirring conditions, and the processing time were changed. ), The toner (a) of the present invention
Was prepared.

(Comparative Toner Production Examples 3 and 4) In place of the wax component <A>, the waxes <c> to <d> shown in Table 1 above were used.
Was carried out in the same manner as in Production Example 1 of the toner except that each was used. However, granulation was difficult or polymer particles were not united during polymerization to obtain polymer particles.

(Comparative Production Example 5 of Toner) Styrene-2-ethylhexyl acrylate-divinylbenzene co-resin (peak molecular weight = 13,000, Mw / Mn = 3.2, Tg = 55 ° C.) 100 parts by mass 4 parts by mass of polycarbonate resin used in Preparation Example 1 6 parts by mass of carbon black used in Production Example 1 of toner 2 parts by mass of azo-based iron complex compound used in Production Example 1 of toner <C> 10 parts by mass

The above mixture was melt-kneaded with a twin-screw extruder, the cooled kneaded material was coarsely pulverized with a hammer mill, the coarsely pulverized material was finely pulverized with a jet mill, and the obtained finely pulverized material was classified and classified. (C). Using the classified powder (c),
Comparative toner (c) in the same manner as in Production Example 1 of the toner.
I got

(Comparative Production Example 6 of Toner) Wax Component <
A classified powder (d) was obtained in the same manner as in Comparative Production Example 5 of the toner except that wax <d> shown in Table 1 was used instead of c>, and then a comparative toner (d) was prepared.

The types and amounts of the wax components used in the toners (A) to (D) obtained above and the comparative toners (a) to (d), and various properties of each of the obtained toners are shown below. Table 2
Put together.

[0158]

[Table 2]

<Examples 1 to 4, Comparative Examples 1 to 4> Toners (A) to (D) obtained in Production Examples 1 to 4 and Comparative Production Examples 1 to 4 described above and comparative toner (a ) To (d) were mixed with 95 parts by mass of a resin-coated ferrite carrier (average particle size: 45 μm), and used for comparison with two-component developers (A) to (D) for magnetic brush development. Developer (a)
To (d) were prepared, and each developer was evaluated using the following image forming apparatus (1).

The image forming apparatus (1) used for the evaluation will be described. FIG. 1 is a schematic explanatory view of a cross section of the image forming apparatus (1).

The photosensitive drum 1 has a photosensitive layer 1b having an organic optical semiconductor on a substrate 1a, and rotates in the direction of the arrow to oppose and rotate in contact with the charging roller 2 (conductive elastic layer 2a,
The photosensitive drum 1 is charged to a surface potential of about -600 V by the cored bar 2b). The exposure 3 is turned on / off on the photoreceptor by a polygon mirror in accordance with digital image information, so that the exposed portion potential is -100V and the dark portion potential is -600V.
Is formed. A plurality of developing units 4-1 and 4-
2, 4-3, and 4-4, a yellow toner, a magenta toner, a cyan toner, or a black toner
A toner image was obtained using a reversal developing method. The toner image is transferred to the intermediate transfer member 5 (elastic layer 5a, core metal 5 as a support).
b) The image is transferred onto the intermediate transfer member 5 to form a color superimposed color development image of four colors. The transfer material toner on the photoreceptor 1 is collected in a residual toner container 9 by a cleaner member 8.

The intermediate transfer member 5 was formed by coating a pipe-shaped core metal 5b with an elastic layer 5b in which a carbon black conductive member was sufficiently dispersed in nitrile-butadiene rubber (NBR). The hardness of the coat layer 5b is determined according to “JIS
K-6301 "and a volume resistivity of 10 ⁹ Ω · cm. The transfer current required for the transfer from the photoreceptor 1 to the intermediate transfer member 5 was about 5 μA, which was obtained by applying +500 V from the power supply to the cored bar 5b.

The outer diameter of the transfer roller 7 is 20 mm and the diameter is 10 m.
An elastic layer 7a formed by coating a core material 7b having a carbon conductivity imparting member sufficiently dispersed in an ethylene-propylene-diene-based terpolymer (EPDM) foam on a metal core 7b having an elastic layer 7a. The elastic layer 7a has a volume resistivity of 10 ⁶ Ω · cm, which is described in “JIS K-630”.
The reference hardness of "1" used was a value showing a value of 35 degrees. A voltage was applied to the transfer roller, and a transfer current of 15 μA was passed.

As the heat fixing device H, a heat roll type fixing device having no oil application function was used. At this time, both the upper roller and the lower roller had a fluororesin surface layer, and the diameter of the roller was 55 mm. The fixing temperature was set at 140 ° C., and the nip width was set at 7 mm.

Under the above set conditions, room temperature and normal humidity (25 ° C., 6
In a 0% RH environment, a continuous mode of a single color (that is, toner consumption is promoted without stopping the developing device) while sequentially supplying a two-component developer at a printout speed of 12 sheets (A4 size) / min. Mode), a printout test was performed, and the printout images obtained were evaluated for the items described below.

Further, each developer was allowed to stand for 7 weeks in a hot-air circulating constant-temperature dryer (manufactured by Satake Chemical Machinery Co., Ltd.) set at 45 ° C., and the developer which was forcibly deteriorated was also evaluated.

At the same time, the used image forming apparatus (1)
And matching were also evaluated.

The transfer residual toner collected by the cleaning was transported to a developing device by a reuse mechanism and reused.

Table 3 summarizes the above evaluation results.

[0170]

[Table 3]

<Embodiment 5 and Comparative Example 5> The developing device of the image forming apparatus (1) shown in FIG. 1 was replaced with that shown in FIG.
In the image forming apparatus (2) in which the moving speed of the toner carrier surface is set to be 3.0 times the moving speed of the electrostatic latent image carrier surface, the toner of Example 1 and the toner of Comparative Example 1 are used. (A) intermittent mode in single color while sequentially replenishing each (that is, a mode in which the developing device is paused for 10 seconds each time one sheet is printed out, and the deterioration of the toner is promoted by the preliminary operation of the developing device when restarting) ) According to the first to fourth embodiments.
The evaluation was performed in the same manner as described above.

The surface roughness Ra of the toner carrier used here was 1.5, the toner regulating blade adhered urethane rubber to the phosphor bronze base plate, and the contact surface with the toner carrier was made of nylon. The coated one was used. The fixing device shown in FIGS. 5 and 6 is used as the heat fixing device H. The surface temperature of the temperature detecting element 31d of the heating element 31 is 140 ° C., and the heating element 21-sponge pressure having a silicone rubber foam in the lower layer. The total pressure between the rollers 33 is 8 kg, and the nip between the pressure roller and the film is 6 mm.
60 μm thick with a low-resistance release layer in which a conductive substance is dispersed in PTEF (high molecular weight type) on the contact surface with the transfer material
m heat-resistant polyimide film was used. Table 4 summarizes the above evaluation results.

[0173]

[Table 4]

<Embodiment 6 and Comparative Example 6> In this embodiment, an image forming apparatus (3) modified by attaching a reuse mechanism to a commercially available laser beam printer LBP-EX (manufactured by Canon Inc.) was used. That is, in FIG. 4, the image forming apparatus (3) removes the untransferred toner on the photosensitive drum 40 from the elastic blade 4 of the cleaner 41 that is in contact with the photosensitive drum.
After being scraped off by the cleaner 2, it is sent to the inside of the cleaner by the cleaner roller.
Through a supply pipe 44 provided with a conveying screw, and returned to a developing device 46 via a hopper 45.A system utilizing the recovered toner is attached again. As a primary charging roller 47, conductive carbon coated with nylon resin is used. Dispersed rubber roller (diameter 12mm, contact pressure 50
g / cm) using a dark portion potential V _D = -700 V, the light potential V _L = -200 V was formed by laser exposure (600 dpi) to the electrostatic latent image bearing member. A developing sleeve 48 having a surface roughness Ra of 1.1 coated with a resin in which carbon black is dispersed as a toner carrier is set to be 1.1 times the moving speed of the photosensitive drum surface. The gap between the photosensitive drum and the developing sleeve (between SD) was 270 μm, and a urethane rubber blade was used as a toner regulating member in contact with the developing sleeve. An AC bias component was superimposed on a DC bias component as a developing bias. The set temperature of the heat fixing device is 150 ° C.
And

Under the above set conditions, room temperature and normal humidity (25 ° C., 6
0% RH) and low temperature and low humidity (15 ° C, 10% RH)
At a printout speed of 12 sheets (A4 size) / min, the toner (A) used in Example 1 and the toner (d) used in Comparative Example 6 are successively replenished while the intermittent mode (that is, one-sheet printing) is used. A printout test was performed in a mode in which the developing unit was stopped for 10 seconds each time the printout was performed, and the deterioration of the toner was promoted by a preliminary operation at the time of restarting, and the obtained printout image was evaluated for the items described below.

The matching between the image forming apparatus (3) used at the same time and the toner was also evaluated.

Table 5 summarizes the above evaluation results.

[0178]

[Table 5]

<Embodiment 7> The printout speed is set to 16 sheets (A4 size) by removing the toner reuse mechanism shown in FIG.
/ Min, except that the toner (A) was successively replenished and a printout test was performed in a continuous mode (that is, a mode in which the consumption of toner is promoted without stopping the developing device). went.

The obtained printout image was evaluated for the following items, and also for matching with the used image forming apparatus. As a result, all items were good.

The evaluation items described in the examples and comparative examples of the present invention and the evaluation criteria will be described.

[Evaluation of Printout Image] <1> Image Density The image density was evaluated by maintaining the image density when a predetermined number of printouts were completed on ordinary paper for copying machines (75 g / m ² ). The image density was measured by using a "Macbeth reflection densitometer" (manufactured by Macbeth Co., Ltd.) with respect to a printout image of a white background portion having a document density of 0.00. A: 1.40 or more B: 1.35 or more and less than 1.40 C: 1.00 or more and less than 1.35 D: less than 1.00

<2> Dot Reproducibility An image of a small-diameter (45 μm) isolated dot pattern as shown in FIG. 8 where the electric field is easily closed by the latent image electric field and is difficult to reproduce was printed out, and the dot reproducibility was evaluated. A: 2 or less defects / 100 B: 3 to 5 defects / 100 C: 6 to 10 defects / 100 D: 11 or more defects / 100 defects

<3> Image fog The fog density (%) was calculated from the difference between the whiteness of the white background portion of the printout image measured by the "Reflectometer" (manufactured by Tokyo Denshoku Co., Ltd.) and the whiteness of the transfer paper. Image fog was evaluated. A: less than 1.5% B: 1.5% or more, less than 2.5% C: 2.5% or more, less than 4.0% D: 4.0% or more

<4> Image Scattering The “den” character pattern shown in FIG.
g / m ² ), the toner scattered around the character at the time of printing (the state shown in FIG. 9B) was visually evaluated. A: Almost no occurrence. B: Slight scattering is observed. C: Slight scattering is observed. D: Remarkable scattering is observed.

<5> Omission of Image The "surprise" character pattern shown in FIG.
8g / m ² ), and the characters are missing when printed (Fig. 10).
(State (b)) was visually evaluated. A: Almost no occurrence. B: Slight hollowing is observed. C: A slight hollow is seen. D: A noticeable hollow is observed.

<6> Fixing Property The fixing property was evaluated by applying a load of 50 g / cm ² , rubbing the fixed image with soft thin paper, and decreasing the image density before and after rubbing (%). A: less than 5% B: 5% or more and less than 10% C: 10% or more, less than 20% D: 20% or more

<7> Offset Resistance The offset resistance was evaluated by printing out a sample image having an image area ratio of about 5% and evaluating the degree of stain on the image after 3000 sheets. A: Not generated. B: Almost no occurrence. C: Stain on the image was slightly observed. D: The stain on the image was remarkable.

[Evaluation of Image Forming Apparatus Matching] After the completion of the printout test, the occurrence of scratches on the surface of each process portion of the image forming apparatus and the adhesion of residual toner and the effect on the printout image were visually evaluated. A: Not generated. B: Although the presence of residual toner and the occurrence of scratches are observed on the surface,
There is no effect on the image. C: The toner is fixed and the surface is scratched, but has little effect on the image. D: Image defects occur due to sticking of the toner and scratches on the surface.

[0190]

As described above, according to the present invention,
By specifying the wax component in the toner composition,
It is possible to form high-quality images for a long time,
Matching with the image forming apparatus is also suitable. In addition, it can exhibit extremely good low-temperature fixability and can prevent the toner from changing with time due to long-term storage.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of an image forming apparatus suitable for the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of a developing device for a two-component developer used in an embodiment of the present invention.

FIG. 3 is an enlarged cross-sectional view of a main part of a developing device for a one-component developer used in an embodiment of the present invention.

FIG. 4 is a schematic explanatory diagram of an image forming apparatus that reuses untransferred toner.

FIG. 5 is an exploded perspective view of a main part of the fixing device used in the embodiment of the present invention.

FIG. 6 is an enlarged cross-sectional view of a main part showing a film state when the fixing device used in the embodiment of the present invention is not driven.

FIG. 7 is a schematic diagram illustrating an example of a cross section of a toner particle including a wax component.

FIG. 8 is an explanatory diagram of an isolated dot pattern for checking development characteristics of toner.

FIG. 9 is a schematic diagram showing a state in which character images are scattered.

FIG. 10 is a schematic diagram showing a state in which a character image is hollow;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor (electrostatic latent image carrier) 2 Charging roller 3 Exposure 4 4-color developing device (4-1, 4-2, 4-3, 4-4) 5 Intermediate transfer body 6 Transfer material 7 Transfer roller 11 Development Agent carrier 13 Photoreceptor drum 30 Stay 31 Heater 31a Heater substrate 31b Heater 31c Surface protective layer 31d Temperature sensor 32 Fixing film 33 Pressure roller 34 Coil spring 35 Film end regulating flange 36 Power supply connector 37 Disconnecting member 38 Inlet Guide 39 Exit guide (separation guide)

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masanori Ito 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2H005 AA06 AA15 CA14 CA30 EA05 EA07 EA10 FA01 FA07 FB01 2H077 AA37 AB02 AC02 AC04 AC16 AD05 AD06 AD13 AD18 AD24 AD36 EA03 EA13 EA14 EA16 FA01

Claims (25)

[Claims] 1. A dry toner having toner particles containing at least a binder resin, a colorant and a wax component, wherein the content of the wax component is 1 to 30 parts by mass relative to 100 parts by mass of the binder resin. And at least 50 to 100% by mass (based on the weight of the wax component) of an ester compound represented by the following formula (A) or (B), or a mixture thereof. Embedded image 2. The wax component has an acid value of 10 mg KO.
2. The dry toner according to claim 1, wherein the H / g is not more than H / g. 3. In a scattergram of a circle-based circularity-circularity based on the number of toners measured by a flow-type particle image measuring apparatus, the circle-equivalent number average diameter D ₁ (μm) of the toner is 2 to 10 μm. And the average circularity of the toner is 0.920 to 0.995, and the circularity standard deviation is 0.04.
The dry toner according to claim 1, wherein the value is less than 0. 4. 4. The toner has an average circularity of 0.950 or more.
The dry toner according to any one of claims 1 to 3, wherein the circularity standard deviation is 0.995 and the circularity standard deviation is less than 0.035. 5. The toner has an average circularity of 0.970 or more.
0.990, circularity standard deviation is 0.015 or more and 0.0
The dry toner according to any one of claims 1 to 3, wherein the ratio is less than 35. 6. In a scattergram of a circle equivalent diameter-circularity based on the number of toners measured by a flow-type particle image measuring device, toner particles having a circularity of less than 0.950 are 15% by number or less. The dry toner according to claim 1, wherein 7. Observation of a tomographic plane of toner particles using a transmission electron microscope (TEM): (1) A circle-equivalent weight average diameter D ₄ (μm ) To 0.9
Twenty tomographic planes of toner particles exhibiting a long diameter R (μm) satisfying the relationship of ≦ R / D ₄ ≦ 1.1 are selected. (2) A phase caused by a wax component present in the tomographic planes of the selected toner particles. Among the separation structures, the longest diameter r of the largest one is measured. (3) The arithmetic mean value (r / R) _{st of the obtained} r / R is 0.05 ≦ (r / R) _st ≦ 0. The dry toner according to any one of claims 1 to 6, wherein the wax component is dispersed in the binder resin in a substantially spherical and / or spindle-shaped island shape so as to satisfy 95. 8. The arithmetic mean value of the r / R (r / R)
_The wax component is dispersed in the binder resin in a substantially spherical and / or spindle-shaped island shape so that _st satisfies 0.25 ≦ (r / R) _st ≦ 0.90. The dry toner according to claim 7, wherein 9. A charging step of applying a voltage to a charging member from the outside to charge the electrostatic latent image carrier; and a latent image forming an electrostatic latent image on the charged electrostatic latent image carrier. Forming the toner image on the electrostatic latent image carrier by developing the electrostatic latent image with the toner carried on the toner carrier; and intermediately developing the toner image on the electrostatic latent image carrier. A transfer step of transferring to a transfer material with or without a transfer body;
A fixing step of heating and fixing the toner image on the transfer material, wherein the toner is a dry toner containing at least a binder resin, a colorant and a wax component, and the content of the wax component is 1 to 30 parts by mass with respect to 100 parts by mass of the binder resin, and at least 50 to 100% by mass of the ester compound represented by the following formula (A) or (B) or a mixture thereof (of the wax component) (Based on mass). Embedded image 10. The wax component has an acid value of 10 mgK.
The image forming method according to claim 9, wherein the OH / g is not more than OH / g. 11. A circle-equivalent number average diameter D ₁ (μm) of the toner in a scattergram of circle-based circularity based on the number of toners measured by a flow-type particle image measuring apparatus.
Is 2 to 10 μm, the average circularity of the toner is 0.920 to 0.995, and the circularity standard deviation is 0.04.
The image forming method according to claim 9, wherein the value is less than zero. 12. The toner has an average circularity of 0.950 or more.
The image forming method according to any one of claims 9 to 11, wherein the circularity standard deviation is less than 0.035 at 0.995. 13. The toner has an average circularity of 0.970 or more.
0.990, circularity standard deviation is 0.015 or more and 0.0
14. The image forming method according to claim 9, wherein the number is less than 35. 14. In a scattergram of circular equivalent-circularity based on the number of toners measured by a flow-type particle image measuring device, toner particles having a circularity of less than 0.950 are 15% by number or less. The image forming method according to claim 9. 15. Observation of a tomographic plane of toner particles using a transmission electron microscope (TEM): (1) A circle-equivalent weight average diameter D ₄ (μm ) To 0.9
Twenty tomographic planes of toner particles exhibiting a long diameter R (μm) satisfying the relationship of ≦ R / D ₄ ≦ 1.1 are selected. (2) A phase caused by a wax component present in the tomographic planes of the selected toner particles. Among the separation structures, the longest diameter r of the largest one is measured. (3) The arithmetic mean value (r / R) _{st of the obtained} r / R is 0.05 ≦ (r / R) _st ≦ 0. The image forming method according to any one of claims 9 to 14, wherein the wax component is dispersed in the binder resin in a substantially spherical and / or spindle-shaped island shape so as to satisfy 95. . 16. The arithmetic mean value of the r / R (r / R) _st
Wherein the wax component is substantially dispersed in the binder resin in the form of spherical and / or spindle-shaped islands so as to satisfy 0.25 ≦ (r / R) _st ≦ 0.90. The image forming method according to claim 15. 17. In the developing step, the moving speed of the toner carrier surface in the developing area is 1.05 to 3.0 times the moving speed of the electrostatic latent image carrier. The image forming method according to any one of claims 9 to 16, wherein the surface roughness Ra (μm) is 1.5 or less. 18. The image forming method according to claim 9, wherein a ferromagnetic metal blade is arranged at a minute interval so as to face the toner carrier. 19. The image forming method according to claim 9, wherein a blade made of an elastic body is brought into contact with the toner carrier. 20. The image forming apparatus according to claim 9, wherein said electrostatic latent image carrier and said toner carrier have a certain interval, and are developed while applying an alternating electric field. Image forming method. 21. The charging step includes: bringing a charging member into contact with the electrostatic latent image carrier, applying a voltage to the charging member from outside,
21. The image forming method according to claim 9, wherein the electrostatic latent image carrier is charged. 22. In a transfer step of electrostatically transferring a toner image on an electrostatic latent image carrier to a transfer material using a transfer device, the electrostatic latent image carrier and the transfer device are interposed via the transfer material. The image forming method according to any one of claims 9 to 21, wherein the image forming method is in contact with the image forming apparatus. 23. The method according to claim 9, wherein in the heat fixing step, the toner image is heat-fixed to the transfer material by a heat fixing device which does not supply an offset preventing liquid or does not have a fixing device cleaner. 23. The image forming method according to any one of the above items. 24. The heat fixing step, wherein the toner image is transferred onto a transfer material by a fixedly supported heating member and a pressing member which is in pressure contact with the heating member and closely adheres to the heating member via a film. 3. The method according to claim 1, wherein the fixing is performed by heating.
3. The image forming method according to any one of 3. 25. An untransferred residual toner on the electrostatic latent image carrier after the transfer is cleaned and collected, and the collected toner is supplied to a developing unit and stored again in the developing unit. 25. The image forming method according to claim 9, further comprising a toner reuse mechanism for developing an electrostatic latent image on the carrier.