JP3287733B2 - Electrostatic image developing toner and image forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic image capable of fixing a toner image formed by an electrophotographic method, an electrostatic recording method or the like to a transfer material by a heat and pressure fixing method, and the toner. And an image forming method using the same.

[0002]

2. Description of the Related Art In a full-color copying machine proposed in recent years, an electrostatic charge image formed on each photoreceptor by using four photoreceptors and a belt-like transfer member is cyan toner,
After developing using magenta toner, yellow toner and black toner, the transfer material is transported between the photoreceptor and the belt transfer member and transferred between straight passes, and then a full-color image is formed, or the surface of the transfer member facing the photoreceptor Generally, a method is used in which a transfer material is wound around by a mechanical action such as an electrostatic force or a gripper, and a development-transfer process is performed four times to obtain a full-color image.

[0003] Toners loaded on these full-color copiers are required to be capable of sufficiently mixing colors in the heating and pressing fixing step without increasing color reproducibility and losing the transparency of an overhead projector (OHP) image. is necessary. Compared with a general black toner for a black-and-white copying machine, the toner for full-color images is preferably a low-molecular-weight binder resin having sharp melt properties. However, when a sharp-melting binder resin is usually used, when the toner is melted in the heating and pressurizing fixing step, the self-cohesive force of the binder resin is low, so that a problem tends to occur in the high-temperature offset resistance. General black toner for black and white copying machines
In order to improve the high-temperature offset resistance at the time of fixing, a relatively high crystalline wax represented by a polyethylene wax or a polypropylene wax is used as a release agent. For example, Japanese Patent Publication No. 52-3304, Japanese Patent Publication No.
3305 and Japanese Patent Application Laid-Open No. 57-52574. However, in the case of full-color image toner, transparency is hindered when projected through OHP due to the high crystallinity of the release agent itself and the difference in refractive index from the material of the OHP sheet, and the projected image has a high saturation. And the brightness becomes lower.

In order to solve this problem, a method of reducing the crystallinity of the wax by using a nucleating material in combination with the wax is disclosed in JP-A-4-149559 and JP-A-4-107.
No. 467. Further, a method using a wax having a low crystallinity is disclosed in JP-A-4-301853,
It is proposed in Japanese Patent Application Laid-Open No. 5-61238. As a wax having a relatively high transparency and a low melting point, there is a montan-based wax.
185660, JP-A-1-185661,
JP-A-1-185662, JP-A-1-185566
No. 3 and JP-A-1-238672. However, these waxes do not sufficiently satisfy all of the transparency in OHP, the low-temperature fixing property at the time of heat and pressure fixing, and the high-temperature offset resistance. For this reason, in a normal color toner, an oil such as silicone oil or fluorine oil is applied to a heat fixing roller without adding a release agent as much as possible, thereby improving high-temperature offset resistance and transparency in OHP. However, the fixed image thus obtained has extra oil adhered to the surface. Oil may adhere to the photoconductor and contaminate it, or the oil may swell the fixing roller, shortening the life of the fixing roller. In order not to generate oil streaks on the fixed image, it is necessary to supply oil uniformly and quantitatively onto the surface of the fixing roller, and the size of the fixing device tends to increase.

[0005] Therefore, the use of oil for preventing high-temperature offset or the use of a small amount of oil in the heating and pressing fixing means is a toner in which the occurrence of offset is suppressed. There is a long-awaited demand for toners having excellent transparency.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrostatic image developing toner and an image forming method which solve the above-mentioned problems.

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner for developing an electrostatic image, which is excellent in transparency in OHP and excellent in high-temperature offset resistance.

An object of the present invention is to provide a toner for developing an electrostatic charge image having excellent low-temperature fixability.

An object of the present invention is to provide a toner for developing an electrostatic image having excellent blocking resistance.

[0010]

The present invention relates to a toner for developing an electrostatic image containing at least a binder resin, a colorant and an ester wax, wherein the ester wax is 100% by weight of the binder resin. 3 to 40 parts by weight per part, and the ester wax is represented by the following formula: R ₁ —COO—R ₂ [wherein R ₁ and R ₂ represent a linear alkyl group having 15 to 45 carbon atoms. Shown respectively. Wherein the ester wax having the same total number of carbon atoms is contained in the ester wax by 50 to 90% by weight.

Further, the present invention provides a method for forming an electrostatic image on an electrostatic image holder, developing the electrostatic image with toner to form a toner image on the electrostatic image holder, An image forming method in which a toner image is transferred to a transfer material via an intermediate transfer body or without an intermediate transfer body, and the toner image on the transfer material is heated and pressurized and fixed. A resin, a colorant and an ester wax, wherein the ester wax is 3 to 4 parts by weight per 100 parts by weight of the binder resin.
0 parts by weight, and the ester wax is represented by the following formula: R ₁ —COO—R ₂ [wherein R ₁ and R ₂ each represent a linear alkyl group having 15 to 45 carbon atoms. Wherein the ester wax having the same total number of carbon atoms is contained in the ester wax in an amount of 50 to 95% by weight.

In the toner of the present invention, in order to improve the low-temperature fixability and offset resistance of the toner and obtain good transparency of a fixed color image on an OHP film, the following formula: R ₁ -COO-R ₂ [Formula 1] In the formula, R ₁ and R ₂ each represent a linear alkyl group having 15 to 45 carbon atoms. And an ester wax containing 50 to 95% by weight (based on wax) of an ester compound having the same total number of carbon atoms.

The content of the ester compound having the same total number of carbon atoms can be measured by the gas chromatography method described below.

The gas chromatography method (GC method)
It is measured using GC-17A (manufactured by Shimadzu Corporation). A sample was prepared by dissolving a 1% by weight solution in toluene in advance.
μ1 is injected into a GC device equipped with an on-column injector. The column is a 0.5 mm diameter x 10 m length Ultr.
a Use Alloy-1 (HT). Column 4
0 ° C to 40 ° C / min. At a heating rate of 200 ° C., and further at 15 ° C./min. At 350 ° C., and then at 7 ° C./min. The temperature is increased up to 450 ° C. at the temperature increasing speed. As the carrier gas, He gas flows under a pressure condition of 50 kPa. The compound species is identified by separately injecting an alkane having a known number of carbon atoms and comparing the same effluent times, or by introducing a gasification component to mass spectrometry. The content of the ester compound is calculated by calculating the ratio of the peak area to the total peak area of the chromatogram.

FIG. 3 shows an example of a chromatogram of the ester wax. From FIG. 3, an ester compound having a total carbon number of 38

[0016]

[Outside 1] Compound containing about 0.6% by weight of a total of 40 carbon atoms

[0017]

[Outside 2] Compound containing about 5.8% by weight of a total of 42 carbon atoms

[0018]

[Outside 3] Is contained in about 19.0% by weight, and the total carbon number is 44.
Is an ester compound

[0019]

[Outside 4] Of about 72.9% by weight, and the total carbon number is 46.
Is an ester compound

[0020]

[Outside 5] Is found to be about 1.7% by weight. In the ester wax used for the measurement, an ester compound having a total carbon number of 44

[0021]

[Outside 6] It has been confirmed that about 72.6% by weight is contained as a main component.

The ester wax used in the present invention comprises:
Generally, it is synthesized from a higher carboxylic acid component similarly to the higher alcohol component. These higher alcohols and higher carboxylic acid components are often obtained from natural products, and are generally composed of a mixture having an even number of carbon atoms. When these mixtures are esterified as they are, by-products having various similar structures are produced as by-products in addition to the intended ester compound, and thus each property of the toner tends to be adversely affected. Therefore, the ester wax used in the present invention can be obtained by purifying the raw materials and products using a solvent extraction or a vacuum distillation operation. In the measurement by the gas chromatography method, when the content of the ester compound having the same total number of carbon atoms is less than 50% by weight, complicated crystal polymorphism and freezing point depression occur.
It is likely to be one of the causes mainly affecting the anti-blocking property and developing property of the toner. Specifically, when the one-component developing method is used, fusion of the toner is likely to occur on the surface of the developing sleeve, and as a result, image streaks in the form of vertical stripes in the circumferential direction of the sleeve are likely to occur on the image. Even when the two-component developing method is used, filming due to the ester wax is likely to occur on the carrier particles and the photoreceptor surface, and the triboelectric charge of the toner is reduced, so that a sufficient triboelectric charge can be continuously obtained. Have difficulty.

The ester compound having the same total carbon number is preferably 55 to 95% by weight, more preferably 6 to 95% by weight.
The fact that the wax is contained in the ester wax in an amount of 0 to 95% by weight is good for maintaining the light transmittance of the color toner image and the predetermined color tone. Further, the total content of the ester compound having a carbon number of ± 2 of the total carbon number of the ester compound most contained in the ester wax is preferably 8
The content is preferably 0 to 95% by weight, more preferably 90 to 95% by weight.

Most preferably, the total carbon number is 44
An ester compound R ₁ ′ -COO-R ₂ ′ (wherein
R ₁ ′ and R ₂ ′ represent linear long-chain alkyl groups having 15 to 45 carbon atoms) in the ester wax in an amount of 50 to 95% by weight.

In the present invention, as the ester compound R ₁ -COO-R ₂ constituting the ester wax, a compound wherein R ₁ and / or R ₂ is a linear alkyl group is used.
Particularly, an ester compound in which R ₁ is a linear alkyl group having 15 to 45 carbon atoms and R ₂ is a linear alkyl group having 16 to 44 carbon atoms is preferable. For example, the following ester compounds can be mentioned.

[0026]

[Outside 7]

The ester wax having the ester compound R ₁ -COO-R ₂ has a main maximal peak (mai) in an endothermic curve measured according to ASTM D3418-8.
npeak) value (hereinafter, referred to as “melting point”) of 40
The temperature is preferably from 90 to 90 ° C (more preferably from 55 to 85 ° C) from the viewpoint of low-temperature fixability and offset resistance of the toner.

An ester wax having a melting point of less than 40 ° C. is not preferred because the self-cohesive force of the ester wax is weak, and as a result, the high-temperature offset resistance decreases.

On the other hand, an ester wax having a melting point of more than 90 ° C. is not preferred because the fixing temperature of the toner becomes high, and it becomes difficult to appropriately smooth the surface of the fixed image, and the color mixing property is lowered. Further, when toner particles are obtained by a direct polymerization method, in order to perform good granulation and polymerization in an aqueous medium, if the melting point is high, ester wax will precipitate during granulation, resulting in a sharp granulation having a particle size distribution. It is not preferable because it becomes difficult.

The measurement according to ASTM D3418-8 is performed by using, for example, DSC-7 manufactured by PerkinElmer. The temperature correction of the device detection unit uses the melting points of indium and zinc, and the heat quantity correction uses the heat of fusion of indium. An aluminum pan was used as a sample, an empty pan was set as a control, and the temperature was raised at a rate of 10 ° C / min. Perform the measurement with.

The ester wax used in the present invention is:
Those having a hardness of 0.5 to 5.0 are preferred. The hardness of the ester wax is a value obtained by preparing a cylindrical sample having a diameter of 20 mmφ and a thickness of 5 mm, and then measuring the Vickers hardness using a dynamic ultra-fine hardness tester (DUH-200) manufactured by Shimadzu Corporation. The measurement conditions are as follows. After displacing 10 μm under a load speed of 9.67 mm / sec with a load of 0.5 g and holding it for 15 seconds, the resulting dent shape is measured to determine the Vickers hardness. An ester wax having a hardness of less than 0.5 is not preferable because the pressure dependency and the process speed dependency of the fixing device increase, and the high-temperature offset resistance tends to decrease. On the other hand, when it exceeds 5.0, the storage stability of the toner decreases, and the self-cohesive force of the ester wax itself is small, so that the high-temperature offset resistance decreases.

The weight average molecular weight of the ester wax (M
w) is preferably from 200 to 2,000, and the number average molecular weight (M
n) is preferably from 150 to 2,000, more preferably Mw is preferably from 300 to 1,000, and Mn is 2
Preferably it is 50-1000. When Mw is less than 200 and Mn is less than 150, the blocking resistance of the toner decreases. Mw exceeds 2000, Mn
Exceeds 2000, the crystallinity of the ester wax itself tends to be developed, and the transparency tends to decrease.

The molecular weight distribution of the wax is measured by GPC under the following conditions.

(GPC Measurement Conditions) Apparatus: GPC-150
C (Waters) Column: GMH-HT 30 cm 2 columns (manufactured by Tosoh Corporation) Temperature: 135 ° C Solvent: o-dichlorobenzene (0.1% ionol added) Flow rate: 1.0 m1 / min Sample: 0.15% sample 0.4 ml injection

Measurement is performed under the above conditions, and the molecular weight of the sample is calculated using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample. In addition, Mark-Hou
It is calculated by converting to polyethylene using a conversion formula derived from the wink viscosity formula.

The amount of the ester wax used is 3 to 40 parts by weight per 100 parts by weight of the binder resin in consideration of obtaining a double-sided fixed image. The double-sided fixing method is a method in which a fixed image is once formed on the front surface of a transfer sheet, and then an image is further formed on the back surface of the transfer sheet. At this time, since the surface-fixed image once fixed passes through the fixing device again, it is necessary to sufficiently consider the high-temperature offset resistance of the toner. Therefore, in the present invention, it is preferable to add a relatively large amount of ester wax. When added in an amount of less than 3 parts by weight, the high-temperature offset resistance is reduced, and the image on the back surface tends to show an offset phenomenon when a double-sided image is fixed. 4
If the amount is more than 0 parts by weight, fusing in the apparatus is apt to occur during the production of the toner by the pulverization method, and coalescence of the toner particles tends to occur during the granulation during the production by the polymerization method. In general, a toner having a wide particle size distribution is easily generated. Further, when the amount exceeds 40 parts by weight, the durability of the toner tends to decrease.

After a toner image is developed on a photoreceptor with toner particles containing 3 to 40 parts by weight (more preferably, 5 to 35 parts by weight) of an ester wax, the toner image on the electrostatic image carrier is developed. Is transferred to an intermediate transfer member, a transfer roller to which a voltage is applied is brought into contact with a transfer material, the toner image on the intermediate transfer member is electrostatically transferred to the transfer material, and the toner image on the transfer material is Also in the full-color image forming method in which the transfer material is heated and fixed by the heating and pressurizing means, the occurrence of toner fusion or filming on the photosensitive member or the intermediate transfer member is suppressed.

As the binder resin used in the present invention, generally used styrene- (meth) acrylic copolymers, polyester resins, epoxy resins, and styrene-butadiene copolymers can be used. In the method of obtaining toner particles by a direct polymerization method, a vinyl monomer is preferably used. Specifically, styrene, o (m
-, P-)-methylstyrene, styrene-based monomers such as m (p-)-ethylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth) acryl Butyl acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate,
(Meth) acrylate monomers such as 2-ethylhexyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and diethylaminoethyl (meth) acrylate; butadiene, isoprene, cyclohexene,
Ene monomers such as (meth) acrylonitrile and acrylamide are preferably used. These can be used alone or in the published Polymer Handbook, 2nd edition III-P139.
192 (manufactured by John Wiley & Sons), and the monomers are appropriately mixed and used so that the theoretical glass temperature (Tg) of 40 to 75 ° C is indicated. When the theoretical glass transition temperature is lower than 40 ° C., the storage stability of the toner and the durability stability of the toner are apt to decrease, while when it exceeds 75 ° C., the fixing temperature becomes high. In particular, in the case of a full-color toner, the color mixing property of each color toner is reduced, the color reproducibility is reduced, and the transparency of the OHP film image is further reduced.

The molecular weight of the binder resin is measured by gel permeation chromatography (GPC). As a specific GPC measurement method, the toner is previously extracted with toluene using a Soxhlet extractor for 20 hours, and then toluene is distilled off from the extract using a rotary evaporator. Further, the ester wax is dissolved but the binder resin is dissolved. After adding an insoluble organic solvent (eg, chloroform) and washing well, tetrahydrofuran (TH
A sample obtained by filtering the solution dissolved in F) through a solvent-resistant membrane filter having a pore diameter of 0.3 μm was used, and the column configuration was A-80 manufactured by Showa Denko using Waters 150C.
1, 802, 803, 804, 805, 806, 807
And measuring the molecular weight distribution using a calibration curve of a standard polystyrene resin. The obtained THF-soluble resin component has a number average molecular weight (Mn) of 5,000 to 1,0.
It is preferable that the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 2 to 100.

In the present invention, it is particularly preferable that the ester wax is encapsulated by the binder resin. To this end, it is effective to add a polar resin to the toner particles. Examples of the polar resin used in the present invention include a copolymer of styrene and (meth) acrylic acid, a maleic acid copolymer,
Saturated polyester resins and epoxy resins are preferably used. It is particularly preferable that the polar resin does not contain an unsaturated group capable of reacting with the binder resin or monomer in the molecule. When a polar resin having an unsaturated group is included, an excessive crosslinking reaction of the monomer forming the binder resin occurs, and the color mixing property is unfavorably reduced.

As the black colorant used in the present invention, carbon black, a magnetic substance, and those toned to black using the following yellow / magenta / cyan colorants are used.

Examples of yellow colorants 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, 97, 109, 1
10, 111, 120, 127, 128, 129, 14
7, 168, 174, 176, 180, 181, 191
Etc. 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 of the present invention is selected from the viewpoints of hue angle, saturation, lightness, weather resistance, transparency on an OHP film, transparency on a film, and dispersibility in toner particles. The amount of the coloring agent to be added is as follows.
It is generally used in an amount of 1 to 20 parts by weight per 00 parts by weight.

When a magnetic material is used as a black colorant, unlike other colorants, 40 to 100 parts by weight of resin are used.
150 parts by weight commonly used.

As the charge control agent used for stabilizing the triboelectric charging characteristics of the toner, a charge control agent which is colorless, has a high toner charging speed, and can stably maintain a constant charge amount is preferable. Further, when a direct polymerization method is used in the present invention, a charge control agent having no polymerization inhibition and having no solubilized substance in an aqueous medium is particularly preferable. Specific compounds include, as negative control agents, alkyl salicylic acid salicylic acid, dialkyl salicylic acid, naphthoic acid, metal compounds of dicarboxylic acids, sulfonic acids, high molecular compounds having carboxylic acids in side chains, boron compounds, urea compounds, silicon Compounds, Curryxarene and the like can be used. As the positive control agent, a quaternary ammonium salt, a polymer compound having the quaternary ammonium salt in the side chain, a guanidine compound, an imidazole compound and the like are preferably used. The charge control agent is preferably used in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the resin. However, in the present invention, the addition of a charge control agent is not essential, and when a two-component developing method is used, a carrier and frictional charging are used, and even when a non-magnetic one-component blade coating developing method is used, a blade member is used. It is not always necessary to include a charge control agent in toner particles by actively utilizing frictional charging with the sleeve member.

When toner particles are 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, Azo or diazo polymerization initiators such as 4-dimethylvaleronitrile and azobisisobutyronitrile; peroxides such as benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide and lauroyl peroxide An oxide polymerization initiator 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 weight based on the monomer. The type of the polymerization initiator varies depending on the polymerization method, but is used alone or in combination with reference to the 10-hour half-life temperature.

In order to control the degree of polymerization, a crosslinking agent, a chain transfer agent, a polymerization inhibitor and the like can be further added and used.

In the method for producing the toner particles of the present invention, a binder resin, an ester wax, a colorant, a charge control agent, and the like are uniformly dispersed using a pressure kneader, an extruder, or a media dispersing machine, and then, are mechanically dispersed. In addition to the method of producing a toner by a so-called pulverization method in which a target is pulverized into a desired toner particle size by subjecting the target to a fine pulverization or collision under a jet stream, and then further subjected to a classification process to sharpen the particle size distribution to form the 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.
231; JP-A-59-53856; JP-A-59-61842; a method of directly producing a toner using a suspension polymerization method; Either a dispersion polymerization method of directly producing a toner using an aqueous organic solvent in which the resulting polymer is insoluble, or an emulsion polymerization method typified by a soap-free polymerization method of producing a toner by directly polymerizing in the presence of a water-soluble polar polymerization initiator. It is possible to produce a toner.

In the method for producing toner particles using a pulverization method, it is extremely difficult to control the shape of the toner. In the melt spray production method, one having a wide particle size distribution is easily produced. In some cases, excessive energy is consumed particularly in the melting step, which is not preferable from the viewpoint of energy use efficiency.

In the dispersion polymerization method, the obtained toner shows an extremely sharp particle size distribution, but the selection range of materials to be used is narrow, and the waste solvent generated due to the use of an organic solvent and the organic process in the production process are not performed. In view of the flammability of the solvent, there is a problem that the manufacturing apparatus is complicated and easily complicated. Emulsion polymerization methods typified by soap-free polymerization are effective because the particle size distribution of the toner is relatively uniform, but when the used emulsifier and initiator terminals are present on the surface of the toner particles, the environmental characteristics are likely to deteriorate.

According to the method for producing a toner used in the present invention, the shape of the toner can be relatively uniformly controlled, a sharp particle size distribution can be easily obtained, and a fine particle toner having a small particle size of 3 to 8 μm can be easily obtained. A suspension polymerization method is particularly preferred. Further, a sheet 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. At this time,
It is also possible to use a compound having a polarity dispersed or dissolved in the monomer to be adsorbed. When suspension polymerization is used as the toner production method of the present invention, toner particles can be directly produced by the following production method. Ester wax, colorant, charge control agent, polymerization initiator, and other additives are added to the monomer, and the monomer composition uniformly dissolved or dispersed by a homogenizer, an ultrasonic disperser, or the like is dispersed and stabilized. It is dispersed in an aqueous medium containing the agent using a conventional stirrer, homomixer, homogenizer or the like. Preferably, the stirring speed and time are adjusted so that the droplets of the monomer composition have a desired size of the toner particles, and the granulation is performed. After that, by the action of the dispersion stabilizer, stirring may be performed to such an extent that the particle state is maintained and the particles are prevented from settling. Polymerization temperature is 4
The polymerization is carried out at a temperature of 0 ° C. or higher, generally 50 to 90 ° C. The temperature may be increased in the latter half of the polymerization reaction, and further, in order to remove unreacted polymerizable monomers and by-products that cause odor at the time of fixing the toner, the second half of the reaction, or a part after the completion of the reaction. The aqueous medium may be distilled off. After the reaction, the generated toner particles are collected by washing and filtration, and dried.

In the suspension polymerization method, it is usually preferable to use 300 to 3000 parts by weight of water as a dispersion medium with respect to 100 parts by weight of the monomer composition. Examples of the dispersant used include inorganic oxides such as tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide,
Examples include magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, and alumina. As the organic compound, for example, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, starch and the like are used. These dispersants are used in an amount of 0.2 to 2.0 based on 100 parts by weight of the polymerizable monomer.
It is preferred to use parts by weight.

As these dispersants, commercially available ones may be used as they are, but in order to obtain fine and uniform dispersed particles, the inorganic compound may be formed under high-speed stirring in a dispersion medium. I can do it. For example, in the case of tricalcium phosphate, a dispersant suitable for a suspension polymerization method can be obtained by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring. In order to make these dispersants finer, a surfactant of 0.001 to 0.1% by weight may be used in combination. Specifically, commercially available nonionic, anionic, and cationic surfactants can be used. For example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate,
Sodium oleate, sodium laurate, potassium stearate, calcium oleate and the like are preferably used.

The toner of the present invention has a shape factor SF-
The value of 1 is 100 to 160, particularly preferably 100 to 15
At 0, toner is preferred.

In the present invention, SF-1 indicating the shape factor is used.
Means, for example, FE-SEM (S-800) manufactured by Hitachi, Ltd.
, 100 toner images enlarged at a magnification of 500 times are sampled at random, and the image information is transmitted via an interface to, for example, an image analyzer (Luzex I, manufactured by Nicole).
Introduced in II) and analyzed, the value calculated by the following equation is defined as shape factor SF-1.

[0058]

[Outside 8] [Wherein, MXLNG indicates the absolute maximum length of the toner particles,
AREA indicates the projected area of the toner particles. ]

The shape factor SF-1 indicates the degree of roundness of the toner particles.

A toner having a toner shape factor SF-1 larger than 160 gradually changes from a spherical shape to an irregular shape, and a reduction in transfer efficiency is recognized as the shape factor SF-1 decreases. When an intermediate transfer member is used to cope with various types of transfer materials, the transfer step is performed substantially twice, so that a decrease in transfer efficiency causes a decrease in toner use efficiency. Further, in recent digital full-color copying machines and digital full-color printers, a color image original is subjected to color separation using a B (blue), G (green), and R (red) filter in advance, and then 20 to
A 70 μm dot latent image is formed and a multicolor color image that is faithful to the original or color information by utilizing the subtractive color mixing action using Y (yellow), M (magenta), C (cyan), and B (black) toners. Need to be reproduced. At this time, since a large amount of Y, M, C, and B toners are applied on the photoreceptor or the intermediate transfer member in accordance with the color information of the document or the CRT, each color toner used in the present invention is extremely High transferability is required. Therefore, the ester wax is preferable in order to maintain good transferability of the toner, and a toner having a shape factor SF-1 of 100 to 160 is more preferable.

In order to faithfully develop minute latent image dots for higher image quality, the weight average diameter measured by a Coulter counter is 3 μm to 8 μm and the number variation coefficient is 3 μm.
5% or less toner is preferred. A toner having a weight average diameter of less than 3 μm has a low transfer efficiency, generates a large amount of untransferred toner on a photoreceptor or an intermediate transfer member, and is likely to cause non-uniform unevenness of an image due to fog or poor transfer. When the weight average diameter of the toner exceeds 8 μm, the resolution and dot reproducibility are reduced, and fusion to each member is apt to occur. When the number variation coefficient of the toner exceeds 35%, the tendency is further increased. Strengthen.

A more preferred toner has a capsule structure in which an ester wax forms a nucleus and an outer shell is formed of a binder resin by a toe tomographic plane measuring method using a transmission electron microscope (TEM) as shown in FIG. Is a toner having: The form of the toner particles is preferable for satisfying the fixing property at a low temperature and the durability of the blocking property of the toner. Unless the toner is not included, the toner cannot be sufficiently pulverized unless a special freeze-pulverization is used in the pulverization process, resulting in only a toner having a wide particle size distribution. This is also not preferable because of the occurrence of the problem. In freezing and pulverization, the device becomes complicated to prevent dew condensation on the device, and if the toner absorbs moisture, it causes a decrease in workability in the production of the toner, and sometimes it is necessary to add a drying process. Is a problem. As a specific method for encapsulating the ester wax, various monomers to be polymerized and become a binder resin, and a small amount of a polar resin or monomer having a higher polarity in an aqueous medium are used in combination to obtain polarization. Even with a large ester wax, a toner having a core-shell structure coated with a shell-binding resin can be obtained. To control the particle size distribution and the particle size of the toner, the method of changing the type and amount of the hardly water-soluble inorganic salt and the dispersant that acts as a protective colloid, and the mechanical device conditions such as the peripheral speed of the rotor, the number of baths, and the stirring blade By controlling the stirring conditions such as the shape and the container shape, or the solid content concentration in the aqueous solution,
A predetermined toner of the present invention can be obtained.

In the present invention, a specific method for measuring the tomographic plane of the toner is as follows. The toner is sufficiently dispersed in a normal-temperature curable epoxy resin, and then cured in an atmosphere at a temperature of 40 ° C. for 2 days. The product is stained with ruthenium tetroxide and, if necessary, osmium tetroxide, and then sliced using a microtome equipped with diamond teeth. The morphology of the toner is measured using a transmission electron microscope (TEM). I do. In the present invention, it is preferable to use a ruthenium tetroxide dyeing method in order to provide a contrast between materials by utilizing a difference in crystallinity between the ester wax used and the resin constituting the outer shell.

The toner of the present invention includes a lubricant powder such as Teflon powder, zinc stearate powder and polyvinylidene fluoride powder; an abrasive such as cerium oxide, silicon carbide and strontium titanate; and a silica and titanium oxide and aluminum oxide. It is preferable to externally add a fluidity improver; an anti-caking agent; a conductivity-imparting agent such as carbon black, zinc oxide, and tin oxide.

In particular, as the inorganic fine powder, inorganic fine powder such as silicic acid fine powder, titanium oxide and aluminum oxide is preferable. The inorganic fine powder is preferably hydrophobized with a hydrophobizing agent such as a silane coupling agent, silicone oil, or a mixture thereof.

The external additive is usually used in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the toner particles.

The toner of the present invention can be used as a one-component developer or a two-component developer toner.

As a one-component developing method, there is a method in which a magnetic toner in which a magnetic substance is contained in toner particles is transported and charged using a developing sleeve containing a magnet. When a non-magnetic toner containing no magnetic material is used, a method of forcibly charging the toner on the developing sleeve using a coating blade, a coating roller, or a fur brush and causing the toner to adhere to the developing sleeve to convey the toner. is there.

On the other hand, in the case of a two-component developer, a carrier is used together with the toner of the present invention. The carrier used is not particularly limited, but mainly,
A magnetic carrier produced solely of iron, copper, zinc, nickel, cobalt, manganese or chromium element, or a magnetic ferrite carrier produced by mixing them is preferred. Saturation magnetization,
The shape of the carrier is also important because the electrical resistance can be controlled over a wide range. For example, it is preferable to select a spherical shape, a flat shape, an irregular shape, and the like, and also to control the fine structure (for example, surface unevenness) of the carrier surface. In general, a method is used in which carrier core particles are generated in advance by baking and granulating the inorganic oxide, and then coating the resin. In order to reduce the load on the toner of the carrier, after kneading the inorganic oxide and the resin, pulverize and classify to obtain a low-density dispersed carrier, or directly knead the inorganic oxide and the monomer in an aqueous medium. It is also possible to use a method of obtaining a polymerized carrier which is subjected to suspension polymerization to obtain a true spherical dispersion carrier.

A coated carrier in which the surface of the carrier particles is coated with a resin is particularly preferred. As the method, a method in which a resin is dissolved or suspended in a solvent and applied and adhered to a carrier, a method in which the resin is simply mixed with a powder, and the like can be applied.

The substance fixed to the surface of the carrier particles varies depending on the toner material. Examples thereof include polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, styrene resin, acrylic resin, and polyamide resin. , Polyvinyl butyral, nigrosine, amino acrylate resin and the like are used alone or in combination.

The amount of the fixing substance used is generally 0.1 to 30% by weight (preferably 0.5 to 30% by weight) based on the total amount of the carrier.
-20% by weight).

The average particle size of these carriers is 10 to 100.
μm, preferably 20 to 50 μm.

For example, the surface of ternary ferrite particles of Cu—Zn—Fe is treated by combining a resin such as a fluororesin and a styrene resin (for example, polyvinylidene fluoride and styrene-methyl methacrylate resin; polytetrafluoroethylene). Styrene-methyl methacrylate resin,
90: a fluorine-based copolymer and a styrene-based copolymer;
10-20: 80, preferably 70: 30-30: 70
Is a mixture of 0.01 to 5% by weight,
Preferably, 0.1 to 1% by weight of coating, 250 mesh pass, 400 mesh on carrier particles 70
It is a coated ferrite carrier having the above average particle size of not less than% by weight. As the fluorine-based copolymer, vinylidene fluoride-tetrafluoroethylene copolymer (10: 9
0 to 90:10). Examples of the styrene-based copolymer include styrene-2-ethylhexyl acrylate (20:90).
80-80: 20), styrene-2-ethylhexyl acrylate-methyl methacrylate (20-60: 5-3
0:10 to 50).

The coated ferrite carrier has a favorable triboelectrification property with respect to the toner of the present invention, and further has the effect of improving electrophotographic characteristics.

When a two-component developer is prepared by mixing a toner and a carrier, the mixing ratio is 2 to 15% by weight, preferably 4 to 13% by weight as the toner concentration in the developer. Would normally give good results.

The magnetic characteristics of the magnetic carrier are preferably as follows. The magnetization strength (σ ₁₀₀₀ ) at 1000 Oe after magnetic saturation is 30 to 300 emu / c.
m ³ is preferred. In order to achieve higher image quality, it is preferably 100 to 250 emu / cm ³ . When it is larger than 300 emu / cm ^3, it is difficult to obtain a high quality toner image. 30e
If it is less than mu / cm ³ , the magnetic binding force is also reduced, and carrier adhesion is likely to occur.

The fixability, offset resistance, color mixture area and transparency of the toner are evaluated as follows.

1) Fixing property, anti-offset property, and mixed color area An unfixed image of toner is created by a commercially available copying machine.

When the toner is a black toner, the fixability and the anti-offset property are evaluated by a heat roller external fixing device having no oil application mechanism.

Further, in the case of a mono-color toner or a full-color toner, using a heat roller external fixing device without an oil application mechanism or a fixing device of a Canon digital full-color copying machine CLC-500, a small amount of oil is evenly dispersed. The composition is applied to a fixing roller (for example, 0.02 g / A4 size) to evaluate the fixing property, the anti-offset property and the color mixing area, and to obtain a fixed image for evaluating the transparency.

As the roller material at this time, a material having a surface layer of a fluororesin or rubber is used for both the upper roller and the lower roller.

As a heat roller external fixing device, a fixing device having an upper roller and a lower roller having a roller diameter of about 60 mm was used.
In the case of K paper (manufactured by Nippon Paper Industries), the nip is 6.5 mm, the process speed is 105 mm / sec,
The temperature control is performed every 5 ° C. within a temperature range of 30 ° C.

The transfer material is, for example, an OHP sheet (trade name: CG)
3300, 3M), the nip is 6.5 mm,
Process speed 25mm / sec, temperature 150 ℃
Perform fixing.

The fixing property was evaluated by applying a load of 50 g / cm ² to a fixed image (including a low-temperature offset image) and applying a load to silbon paper [Lenz Cleaning Paper “das”.
per (R) "(Ozu Paper Co. Ltd.
d)], the temperature at which the density reduction rate before and after rubbing is less than 10% is defined as the fixing start point.

The offset resistance is determined by setting the temperature at which the offset disappears visually as a low-temperature offset starting point, and raising the temperature.
The highest temperature without offset is defined as the hot offset end point.

Further, the image in the non-offset area is mixed with the handy gloss meter gloss checker IG-310.
(Manufactured by Horiba, Ltd.), and the gloss value was 7
The area is determined by defining the area up to the maximum value.

2) Transparency The transmittance and haze (haze) of the obtained fixed image with respect to each image density were measured, and the numerical value at an image density of 1.2 was used.
The transparency was evaluated. The method for measuring the transmittance and haze is described below.

The transmittance was measured using a Shimadzu self-recording spectrophotometer UV.
Using a 2200 (manufactured by Shimadzu Corporation), the transmittance of the OHP film alone is set to 100%, and the transmittance at the maximum absorption wavelength at magenta toner: 650 nm, cyan toner: 500 nm, yellow toner: 600 nm Is measured.

The haze was measured using a haze meter NDH-3.
It is measured using 00A (manufactured by Nippon Shikara Kogyo).

[0091]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The image forming method of the present invention will be described more specifically with reference to FIG.

In the apparatus system shown in FIG. 2, the developing units 4-1, 4-2, 4-3, and 4-4 respectively include a developer containing a cyan toner and a developer containing a magenta toner.
A developer having a yellow toner and a developer having a black toner are introduced, and the electrostatic charge image formed on the photoconductor 1 is developed by a magnetic brush development method or a non-magnetic one-component development method. 1 is formed.
Photoconductor 1 is made of a-Se, CdS, ZnO ₂ , OPC, a-
A photosensitive drum or a photosensitive belt having a photoconductive insulating material layer such as Si. The photoconductor 1 is rotated in a direction indicated by an arrow by a driving device (not shown).

As the photosensitive member 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 transporting ability in the same layer.
It may be a single layer type, or may be a function-separated type photosensitive layer having a charge transport layer and a charge generation layer as components. 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, and poor cleaning, fusion of a toner to a photoreceptor, and filming of an external additive. Less likely.

In the present invention, in the charging step, there are a system that is not in contact with the photoreceptor 1 using a corona charger, and a contact system that uses a roller or the like, and any of them 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 has a basic configuration of a central core 2b and a conductive elastic layer 2a formed on the outer periphery. The charging roller 2 is pressed against the surface of the photoconductor 1 with a pressing force, and is rotated by the rotation of the photoconductor 1.

The preferable process conditions when the charging roller is used are that the contact pressure of the roller is 5 to 500 g / c.
m, when an AC voltage superimposed on a DC voltage is used, an AC voltage = 0.5 to 5 kVpp and an AC frequency = 5
0 Hz to 5 kHz, DC voltage = ± 0.2 to ± 1.5 kV
When a DC voltage is used, DC voltage = ± 0.2
±± 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 a conductive rubber, and a release coating may be formed 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 photosensitive member is applied with a voltage (for example, ±
(0.1 to ± 5 kV). A system in which the toner image on the photoconductor is directly transferred to a transfer material without passing through the intermediate transfer body 5 may be used.

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 elastic layer 5a of medium resistance is made of silicon rubber,
Teflon rubber, chloroprene rubber, urethane rubber, EP
An elastic material such as DM (terpolymer of ethylene propylene diene) is mixed with a conductivity-imparting material such as carbon black, zinc oxide, tin oxide, and silicon carbide to disperse the material to have an electric resistance value (volume resistivity) of 10%. ^{It is} a solid or foamed layer adjusted to a medium resistance of ⁵ to 10 ¹¹ Ω · cm.

The intermediate transfer member 5 is arranged in parallel with the photosensitive member 1 so as to be in contact with the lower surface of the photosensitive member 1 and is rotated at the same peripheral speed as the photosensitive member 1 in the counterclockwise direction indicated by the arrow. I do.

In the process in which the toner image of the first color formed and carried on the surface of the photosensitive member 1 passes through the transfer nip portion where the photosensitive member 1 and the intermediate transfer member 5 are in contact with each other, the transfer nip is applied by the transfer bias applied to the intermediate transfer member 5. The intermediate transfer is sequentially performed on the outer surface of the intermediate transfer body 5 by the electric field formed in the area.

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.

A transfer means is provided in parallel with the intermediate transfer body 5 and is brought into contact with the lower surface of the intermediate transfer body 5. The transfer means is, for example, a transfer roller 7 and has the same circumference as the intermediate transfer body 5. It rotates clockwise as indicated by the arrow. The transfer roller 7 may be disposed so as to be in direct contact with the intermediate transfer member 5, and a belt or the like may be disposed between the intermediate transfer member 5 and the transfer roller 7.
May be arranged so as to be in contact therewith.

The transfer roller 7 basically has 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 used in the present invention, general materials can be used. In the present invention, the voltage applied to the transfer roller can be reduced by setting the volume resistivity of the elastic layer of the transfer roller to be smaller than the volume resistivity of the elastic layer of the intermediate transfer body, and the transfer material has a good quality. It is possible to form a toner image and 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.

The hardness of the intermediate transfer member and the transfer roller is determined by JI
It is measured according to SK-6301. The intermediate transfer member used in the present invention is preferably composed of an elastic layer belonging to the range of 10 to 40 degrees. On the other hand, the hardness of the elastic layer of the transfer roller is higher than the hardness of the elastic layer of the intermediate transfer member.
Those having a value of from -80 degrees are preferred in order to prevent the transfer material from winding around the intermediate transfer member. When the hardness of the intermediate transfer member and that of the transfer roller are reversed, a concave portion is formed on the transfer roller side, and the winding of the transfer material around the intermediate transfer member is likely to occur.

The transfer roller 7 is rotated at a constant speed or a peripheral speed different from that of the intermediate transfer member 5. The transfer material 6 is conveyed between the intermediate transfer member 5 and the transfer roller 7, and at the same time, a bias having a polarity opposite to the triboelectric charge of the toner is applied to the transfer roller 7 from the transfer bias means, so that the transfer material 6 Is transferred to the front side of the transfer material 6.

As the material of the transfer rotary member, the same material as that of the charging roller can be used. The preferable transfer process condition is that the contact pressure of the roller is 5 to 500 g.
/ Cm, and the DC voltage is ± 0.2 to ± 10 kV.

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.

Next, the transfer material 6 is conveyed to a fixing device 11 having a heating roller having a built-in heating element such as a halogen heater and an elastic pressure roller pressed against the heating roller with a pressing force. The toner image is heated and pressed on the transfer material by passing between the roller and the pressure roller.
A fixing method using a heater via a film may be used.

Preparation of Ester Wax 1740 parts by weight of benzene, 1300 parts by weight of a long-chain alkyl carboxylic acid component, 1200 parts by weight of a long-chain alkyl alcohol component were placed in a four-neck flask reactor equipped with a Dimroth reflux condenser and a Dean-Stark water separator. Further, 120 parts by weight of p-toluenesulfonic acid was added, and the mixture was sufficiently stirred and dissolved. After refluxing for 5 hours, the valve of the water separator was opened.
An azeotropic distillation was performed. After azeotropic distillation, the residue was sufficiently washed with sodium hydrogen carbonate, dried, and benzene was distilled off. The obtained product was recrystallized, washed and purified to obtain an ester wax.
Each ester wax was prepared by changing the type and amount of the long-chain alkyl carboxylic acid and the type and amount of the long-chain alkyl alcohol.

Table 1 shows the data of each ester wax.

Long-chain alkyl carboxylic acid component palmitic acid (C ₁₆ H ₃₂ O ₂ ) stearic acid (C ₁₈ H ₃₆ O ₂ ) arachidic acid (C ₂₀ H ₄₀ O ₂ ) behenic acid (C ₂₂ H ₄₄ O ₂ ) lignocerin acid (C ₂₄ H ₄₈ O ₂₎

Long-chain alkyl alcohol component Palmityl alcohol (C ₁₆ H ₃₄ O) Stearyl alcohol (C ₁₈ H ₃₈ O) Arachidel alcohol (C ₂₀ H ₄₂ O) Behenyl alcohol (C ₂₂ H ₄₆ O)

[0119]

[Table 1]

Preparation of Comparative Ester Wax (a) The amount of behenic acid and behenyl alcohol was reduced,
Comparative ester waxes (a) were prepared in which the total content of ester compounds having the same total carbon number was less than 50% by weight. Table 2 shows the data of the comparative ester wax (a).

Preparation of Comparative Ester Wax (b) Comparative ester wax (b) was prepared using only behenic acid as an acid component and using only behenyl alcohol as an alcohol component. Table 2 shows the data of the comparative ester wax (b).

[0122]

[Table 2]

Example 1 A cyan toner was prepared as follows. In a four-necked flask equipped with a high-speed stirrer TK-homomixer, 710 parts by weight of ion-exchanged water and 0.1 mol / l-Na ₃ P
450 parts by weight of an O ₄ aqueous solution was added, and the number of revolutions was
pm and warmed to 65 ° C. 68 parts by weight of a 1.0 mol / liter CaCl ₂ aqueous solution was gradually added thereto to prepare an aqueous dispersion medium containing a minute water-insoluble dispersion stabilizer Ca ₃ (PO ₄ ) ₂ .

Styrene monomer 165 parts by weight n-butyl acrylate monomer 35 parts by weight Cyan colorant (CI Pigment Blue 15: 3) 14 parts by weight Polar resin [saturated polyester (terephthalic acid-propylene oxide-modified bipolymer) Sphenol A, acid value 15, peak molecular weight 6000)] 10 parts by weight Negative charge control agent (metal dialkylsalicylate) 2 parts by weight Ester wax (A) 60 parts by weight

The above mixture was dispersed using an attritor for 3 hours, and then a polymerizable monomer composition to which 10 parts by weight of a polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) was added. Was charged into an aqueous dispersion medium, and granulated for 15 minutes while maintaining the rotation number at 12,000 rpm.
Thereafter, the stirrer was changed from a high-speed stirrer to a propeller stirring blade, and polymerization was continued at 200 rpm for 10 hours while keeping the internal temperature at 65 ° C. After completion of the polymerization, the slurry was cooled, and diluted hydrochloric acid was added to remove the dispersion stabilizer. After further washing and drying, an electrically insulating cyan toner having a weight average diameter of 6 μm, a coefficient of variation in the number distribution of 23% and an SF-1 of 115 was obtained. FIG. 1 shows a schematic view of a tomographic photograph of the obtained cyan toner. The structure showed that the ester wax was covered with the outer shell resin (Mw 61000, Mn 14500).

Examples 2 to 4 I. Pigment Yellow 17, C.I. I. Pigment Red 202, grafted carbon black, and an electrically insulating yellow toner in the same manner as in Example 1.
An electrically insulating magenta toner and an electrically insulating black toner were obtained. Table 3 shows the physical properties of each color toner.

[0127]

[Table 3]

Fifth Embodiment FIG. 2 is a sectional view of an image forming apparatus used in the fifth embodiment. The photoreceptor 1 has a photosensitive layer 1b having an organic optical semiconductor on a substrate 1a, and is rotated in the direction of an arrow, and is rotated by a charging roller 2 (a conductive elastic layer 2a and a cored bar 2ba) that rotates in contact with the photoreceptor. 1 is charged to a surface potential of about -600V. The exposure 3 is turned on and off on the photoreceptor by a polygon mirror in accordance with digital image information, thereby forming an electrostatic image having an exposure portion potential of -100 V and a dark portion potential of -600 V. Plurality of developing units 4-1, 4-2, 4-3, 4-4
To obtain a toner image on the photoreceptor 1 by using a yellow toner, a magenta toner, a cyan toner or a black toner by a reversal developing method. The toner image is transferred onto the intermediate transfer member 5 (elastic layer 5a, core metal 5b as a support) for each color, and a four-color superimposed developed image is formed on the intermediate transfer member 5.
The transfer material toner on the photoreceptor 1 is cleaned by the cleaner member 8.
The toner is collected in the remaining toner container 9.

Since the spherical toner has a higher transfer efficiency than the irregular toner, the problem hardly occurs even in a simple system without a bias roller or a cleaner member. The intermediate transfer member 5 includes a carbon black conductive member provided on a pipe-shaped core metal 5b by nitrile-butadiene rubber (NBR).
The elastic layer 5b sufficiently dispersed therein was coated. The hardness of the coat layer 5b was 30 degrees according to JIS K-6301, and the volume resistivity was 10 ⁹ Ω · cm. The transfer current required for transfer from the photosensitive member 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. After transferring the toner from the intermediate transfer body 5 to the transfer material 6, the intermediate transfer surface may be cleaned by the cleaner member 10. The transfer roller 7 having a diameter of 20 mm is formed by coating a core metal 7 b having a diameter of 10 mm with a carbon conductive material sufficiently dispersed in an ethylene-propylene-diene-based terpolymer (EPDM) foam. Having an elastic layer 7a generated by
The volume resistivity of the elastic layer 7a is 10 ⁶ Ω · cm,
Hardness based on IS K-6301 having a value of 35 degrees was used. A voltage was applied to the transfer roller, and a transfer current of 15 μA was passed. As a cleaning member, a fur brush cleaner or a cleaning member-less system is generally used as a cleaning member for the contaminated toner on the transfer roller 7 when the toner is collectively transferred from the intermediate transfer member 5 to the transfer material 6. Of 100 to 160
(More preferably 100 to 150, further preferably 1
00 to 125), a cleaning member-less system could be adopted for high transfer efficiency.

The cyan toner, yellow toner, magenta toner and black toner obtained in Examples 1 to 4 were externally added with 2 wt% of hydrophobic titanium oxide fine particles to obtain cyan toner having excellent fluidity. A two-component developer was prepared by mixing 6 parts by weight of the obtained cyan toner and 94 parts by weight of a resin-coated magnetic ferrite carrier having an average particle diameter of 50 μm.

The prepared two-component developers of each color were supplied to developing units 4-1 4-2, 4-3 and 4-4 shown in FIG.
And a toner image of each color toner was formed by the magnetic brush developing method under the above-described image forming conditions. The toner of each color toner image had a triboelectric charge of −15 to −18 μc / g. The toner images of each color are sequentially transferred from the photoreceptor 1 to the intermediate transfer member 5, and the four color toner images on the intermediate transfer member 5 are transferred to a transfer material (plain paper) having a basis weight of 199 g / m ^2. The four color toner images were thermally fixed by the heat and pressure fixing means 11.

After the toner image was transferred from the intermediate transfer member 5 to the transfer material, the surface of the intermediate transfer member 5 was sequentially cleaned by the cleaning means 10.

At this time, the transfer efficiency of each color toner from the photosensitive member 1 to the intermediate transfer member 5 is 95% to 98%, and the transfer efficiency from the intermediate transfer member 5 to the transfer material 6 is 99%. The transfer efficiency was as high as 94.1% to 97.0%.

A high-quality image with excellent color mixing properties and no voids was obtained. Further, a double-sided image was formed, but no occurrence of offset was observed on both the front and back surfaces of the transfer material. A durability test was also conducted on 50,000 sheets. However, there was no change in the image density between the initial stage and after the endurance, and no toner was fused to each member.

Example 6 A two-component developer for magnetic brush development was prepared in the same manner as in Example 5 by using the cyan toner, yellow toner, magenta toner and black toner prepared in Examples 1 to 4. Canon digital full-color copying machine CL that transfers images from a photosensitive drum to a transfer material without using a transfer body
It was introduced into C-500, and unfixed images were formed on plain paper and OHP film in single color mode and full color mode, respectively. The fixing property of an unfixed image on plain paper was adjusted to a temperature of 80 by using a heat roller external fixing machine having a 60 mm diameter upper roller having a fluororesin surface layer and a 60 mm diameter lower roller having a fluororesin surface layer. ~ 23
The evaluation was performed in the range of 0 ° C. The unfixed image on the OHP film was fixed using a heat roller external fixing machine at a temperature of 150 ° C.

Tables 8 to 10 show the evaluation results.

Comparative Examples 1 to 4 Examples 1 to 4 except that paraffin wax (Mw550) was used instead of the ester wax (A).
, A cyan toner, a yellow toner, a magenta toner and a black toner were prepared. Table 4 shows the physical properties of the obtained toner.

[0138]

[Table 4]

Example 5 Using the obtained toners of the respective colors,
A two-component developer for magnetic brush development was prepared in the same manner as in Example 6 and evaluated in the same manner as in Example 6. Tables 8 to 1 show the results.
0 is shown.

Comparative Examples 5 to 8 Cyan, yellow, magenta and black toners were prepared in the same manner as in Examples 1 to 4 except that polyethylene wax (Mw 1000) was used instead of the ester wax (A). did. Table 5 shows the physical properties of the obtained toner.

[0141]

[Table 5]

Using the obtained toners of the respective colors, Example 5
A two-component developer for magnetic brush development was prepared in the same manner as in Example 6 and evaluated in the same manner as in Example 6. Tables 8 to 1 show the results.
0 is shown.

Comparative Examples 9 to 12 Example 1 was repeated except that polypropylene wax (Mw1100) was used instead of the ester wax (A).
4 to 4, a cyan toner, a yellow toner, a magenta toner and a black toner were prepared. Table 6 shows the physical properties of the obtained toner.

[0144]

[Table 6]

Using the obtained toners of the respective colors, Example 5
A two-component developer for magnetic brush development was prepared in the same manner as in Example 6 and evaluated in the same manner as in Example 6. Tables 8 to 1 show the results.
0 is shown.

Comparative Examples 13 to 16 Instead of the ester wax (A), the formula R ₃ —COO—
(CH ₂ -CH ₂₎ - in _n OOC-R ₄ [wherein, R ₃ and R ₄ represents a linear alkyl group having 19 to 29 carbon atoms,
n represents an integer.] A cyan toner, a yellow toner, and a magenta toner are prepared in the same manner as in Examples 1 to 4, except that a montan ester wax E (manufactured by Hoechst) having an ester compound represented by And a black toner. Table 7 shows the physical properties of the obtained toner.

[0147]

[Table 7]

Example 5 Using the obtained toners of the respective colors,
A two-component developer for magnetic brush development was prepared in the same manner as in Example 6 and evaluated in the same manner as in Example 6. Tables 8 to 1 show the results.
0 is shown.

Comparative Example 17 A cyan toner was prepared in the same manner as in Example 1, except that the amount of the ester wax (A) was changed to 4 parts by weight. In the obtained cyan toner, the binder resin 10
The content of the ester wax (A) per 0 parts by weight is 1.9.
Parts by weight.

Using the obtained cyan toner, a two-component developer for magnetic brush development was prepared in the same manner as in Example 5, and evaluated in the same manner as in Example 6. Tables 8 and 1 show the results.
0 is shown.

Comparative Example 18 A cyan toner was prepared in the same manner as in Example 1, except that the amount of the ester wax (A) was changed to 110 parts by weight. In the obtained cyan toner, the content of the ester wax (A) was 5 per 100 parts by weight of the binder resin.
2 parts by weight.

Using the obtained cyan toner, a two-component developer for magnetic brush development was prepared in the same manner as in Example 5, and evaluated in the same manner as in Example 6. Tables 8 and 1 show the results.
0 is shown.

Comparative Example 19 A cyan toner was prepared in the same manner as in Example 1, except that the comparative ester wax (a) was used instead of the ester wax (A). A two-component developer for development was prepared and evaluated in the same manner as in Example 6. The results are shown in Tables 8 and 10.

Comparative Example 20 A cyan toner was prepared in the same manner as in Example 1 except that the comparative ester wax (b) was used instead of the ester wax (A). A two-component developer for development was prepared and evaluated in the same manner as in Example 6. The results are shown in Tables 8 and 10.

[0155]

[Table 8]

[0156]

[Table 9]

[0157]

[Table 10]

Examples 7 to 13 A cyan toner was prepared in the same manner as in Example 1 except that the ester waxes (B) to (H) were used. A system developer was prepared and evaluated in the same manner as in Example 6. The results are shown in Tables 11 and 12.

[0159]

[Table 11]

[0160]

[Table 12]

[0161]

The toner of the present invention contains the above-mentioned specific ester wax, whereby the transparency of the fixed image of the OHP film can be improved, the fixing property and the offset resistance are excellent, and a color image or a full-color image can be formed. It is very suitable.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a toner tomographic image according to a first exemplary embodiment.

FIG. 2 is a schematic diagram illustrating an example of an image forming apparatus suitable for the present invention.

FIG. 3 is a diagram showing an example of a gas chromatogram of an ester wax.

FIG. 4 is a view showing a gas chromatogram of an ester wax (A).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor (electrostatic latent image holding body) 2 Charging roller 3 Exposure 4 Four-color developing device (4-1, 4-2, 4-3, 4-4) 5 Intermediate transfer body 6 Transfer material 7 Transfer roller

Continuing on the front page (72) Inventor Tatehiko Chiba 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Tatsuya Nakamura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-6-11881 (JP, A) JP-A-6-123994 (JP, A) JP-A-61-28967 (JP, A) JP-A-5-341573 (JP, A) Japanese Patent Application Laid-open No. Hei 1-230072 (JP, A) JP-A-61-46955 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 9/08 365

Claims (31)

(57) [Claims] 1. An electrostatic image developing toner containing at least a binder resin, a colorant and an ester wax, wherein the ester wax is used in an amount of 3 parts per 100 parts by weight of the binder resin.
The ester wax is represented by the following formula: R ₁ -COO-R ₂ [wherein R ₁ and R ₂ are straight-chain having 15 to 45 carbon atoms.
Alkyl groups are shown below. And ester compounds having the same total carbon number are 50 to 95.
A toner for developing an electrostatic image, wherein the toner is contained in an ester wax by weight. 2. An electrostatic image developing method according to claim 1, wherein R ₁ is a linear alkyl group having 15 to 45 carbon atoms, and R ₂ is a linear alkyl group having 16 to 44 carbon atoms. toner. Wherein the ester wax is claim 1 or 2 is contained 5 to 35 parts by weight binder resin 100 parts by weight per binding
3. The toner for developing an electrostatic image according to item 1. 4. The ester wax has a weight average molecular weight (Mw) of 200 to 2,000 and a number average molecular weight (Mn).
The toner according to any one of claims 1 to 3 has a 150 to 2000. 5. The ester wax, the total toner according to any one of claims 1 to 4 carbon atoms containing the same ester compound 55 to 95 wt%. 6. The toner according to claim 5 , wherein the ester wax contains 60 to 95% by weight of an ester wax having the same total carbon number. 7. The ester wax, ester compound to claim 1 containing 80 to 95 wt% in total of which has a carbon number of ± 2 of the carbon atoms of the total of the largest number ester is contained compound 6 The toner for developing electrostatic images according to any one of the above. 8. ester wax, according to claim 7 containing 90-95 wt% of the ester compounds in total having a carbon number of ± 2 of the carbon atoms of the total of the largest number esters are contained compounds For developing electrostatic images. 9. The binder resin has a THF-soluble number average molecular weight (Mn) of 5,000 to 1,000,000, and a ratio (Mw) between the weight average molecular weight (Mw) and the number average molecular weight (Mn). / Mn) is 2 to 100, the toner for developing an electrostatic image according to any one of claims 1 to 8 . 10. esters wax, toner according to any one of claims 1 to 9 are encapsulated in the binder resin. 11. The colorant is a cyan colorant, toner according to any one of claims 1 to 10 magenta colorant or yellow colorant. 12. The toner has toner particles, said toner particles of the polymerizable monomer, a colorant, directly from a monomer composition containing at least the ester wax and a polymerization initiator in the aqueous phase 1 to 1
2. The toner for developing an electrostatic image according to any one of 1 . 13. A toner having a shape factor SF-1 of 100 to 100.
The toner for developing an electrostatic image according to any one of claims 1 to 12 , wherein the toner is 160. 14. A toner having a shape factor SF-1 of 100 to 100.
The toner for developing an electrostatic image according to claim 13 , wherein the toner is 150. 15. The toner is weight average diameter of 3 to 8 [mu] m, according to claim 1 to 14 number variation coefficient of 35% or less
The toner for developing electrostatic images according to any one of the above. 16. An electrostatic charge image is formed on an electrostatic image holder, and the electrostatic image is developed with toner to form a toner image on the electrostatic image holder. An image forming method for transferring a toner image onto a transfer material via a transfer member or without an intermediate transfer member, and fixing the toner image on the transfer member by heating and pressing, wherein the toner includes at least a binder resin and a colorant. And ester wax, wherein the ester wax contains 3 parts per 100 parts by weight of the binder resin.
The ester wax is represented by the following formula: R ₁ -COO-R ₂ [wherein R ₁ and R ₂ are straight-chain having 15 to 45 carbon atoms.
Alkyl groups are shown below. And ester compounds having the same total carbon number are 50 to 95.
An image forming method characterized by being contained in an ester wax by weight. 17. The image forming method according to claim 16 , wherein the toner image on the transfer material has at least two kinds of toners selected from the group consisting of cyan toner, magenta toner, yellow toner, and black toner. . 18. The image forming method according to claim 16 , wherein R ₁ is a linear alkyl group having 15 to 45 carbon atoms, and R ₂ is a linear alkyl group having 16 to 44 carbon atoms. . 19. The ester wax is a binder resin 100.
The image forming method according to any one of claims 16 to 18 , wherein the content is 5 to 35 parts by weight per part by weight. 20. The ester wax has a weight average molecular weight (Mw) of 200 to 2,000 and a number average molecular weight (Mn).
The image forming method according to any one of claims 16 to 19 , wherein the number is in the range of 150 to 2,000. 21. esters wax, image forming method according to any one of claims 16 to 20 carbon atoms in total are contain identical ester compound 55 to 95 wt%. 22. The image forming method according to claim 21 , wherein the ester wax contains 60 to 95% by weight of an ester wax having the same total carbon number. 23. esters wax, ester compound according to claim 16 or 22 containing 80 to 95 wt% in total of which has a carbon number of ± 2 of the carbon atoms of the total of the largest number esters are contained compounds The image forming method according to any one of the above. 24. esters wax, claim 23 containing 90-95 wt% of the ester compounds in total having a carbon number of ± 2 of the carbon atoms of the total of the largest number esters are contained compounds Image forming method. 25. The binder resin has a THF-soluble component number average molecular weight (Mn) of 5,000 to 1,000,000,
The ratio of the weight average molecular weight (Mw) to number average molecular weight (Mn) (Mw / Mn) is claims 16 to 24 2 to 100
The image forming method according to any one of the above. 26. esters wax, image forming method according to any one of claims 16 to 25 are encapsulated with the binder resin. 27. The colorant is a cyan colorant, an image forming method according to any one of claims 16 to 26 is a magenta colorant, or a yellow colorant. 28. The toner has toner particles, said toner particles of the polymerizable monomer, a colorant, directly from a monomer composition containing at least the ester wax and a polymerization initiator in the aqueous phase Claims 16 to 16 which are generated in
28. The image forming method according to any one of 27 . 29. The toner has a shape factor SF-1 of 100.
The image forming method according to any one of claims 16 to 28 , wherein 30. A toner having a shape factor SF-1 of 100 or more.
The image forming method according to claim 29 , wherein the number is 150. 31. The toner has a weight average diameter of 3 to 8 μm.
, And the image forming method according to any one of claims 16乃<br/> optimum 30 number variation coefficient of 35% or less.