JP2001147555A - Full-color image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonmagnetic one-component black toner which is provided with a satisfactory electric charge imparting effect in a developing device using a nonmagnetic one-component system and having a small-sized developing roll and an electrifying blade, can ensure an adequate quantity of electric charges because of rapid build-up of electrostatic charge, causes slight extra toner fog to a photoreceptor and no stain of white part of print, gives a solid image having good homogeneousness, has good storage stability even in the case of long-time storage, can ensure satisfactory fluidity necessary for a toner and has good coveyability. SOLUTION: In the full-color image forming method in which a color image is formed using plural color toners and a black toner, each of the color toners and the black toner contains at least a bonding resin, a polyolefin wax, a colorant and an electrostatic charge controlling agent, the softening temperature of each of the color toners is lower than that of the black toner and the amount of the polyolefin wax in each of the color toners is equal to on larger than that of the polyolefin wax in the black toner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image forming method for forming an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, and the like.
The present invention relates to a full-color image forming method for forming a color image using three primary yellow toners and a black toner.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic method, US Pat.
No. 221776, No. 2297691, No. 2357
As described in the specification such as 809, the photoconductive insulating layer is uniformly charged (charging step), and then the layer is exposed (exposure step) to dissipate the charge in the exposed portion. An electrostatic latent image is formed thereon, and a colored charged fine powder called toner is made to adhere to the electrostatic latent image so as to be visualized (development step). After the image is transferred onto a transfer material (transfer step), the image is permanently fixed by heating, pressure or other appropriate means (fixing step). After the transfer of the toner image, the residual toner on the photoconductor is scraped off to clean the photoconductor surface (cleaning step). Also, a full-color electrophotographic method for obtaining a multicolor image of color is disclosed in US Pat. No. 2,962,374.
At least, the image is separated into three primary color signals of cyan, magenta and yellow and exposed, and the above process is performed at least a plurality of times using process colors such as cyan, magenta and yellow. This is to repeatedly develop and obtain a multicolor image in which toner images are superimposed.

In recent years, optical information processing such as masking processing and UCR processing (under color removal), which has been difficult with the conventional analog system, has been made easier by adopting the digital system. Conventionally, a portion expressing black by superimposing three primary color toners of cyan, magenta and yellow can be replaced by the black toner alone, so that the gray balance of the image is improved and the thickness of the toner layer is reduced. This is advantageous in terms of cost and image curl development during fixing. Therefore, as a recent full-color toner, a four-color toner obtained by adding a black toner to three primary colors of cyan, magenta, and yellow is used, but another color toner may be added as necessary. .

As a method of forming a full-color image using an electrophotographic method, various known methods can be used. For example, a toner image formed on a photoreceptor is wound around a transfer drum for each color. Intermediate transfer in which four color toner images are superimposed on an intermediate transfer body such as a transfer drum system, a belt shape, a drum shape, etc., which is transferred onto recording paper and four colors are superimposed on the recording paper, and then transferred onto recording paper in four colors There are a tandem system that has a photoconductor and a developing unit for each of the four colors and sequentially superimposes four colors on recording paper in one pass, and a multiple transfer system that superimposes four colors on the photoconductor and then transfers it to recording paper. . On the other hand, in digital full-color copying machines, printers, and the like, black and white images are still mainly used in general office applications, and so-called matte-tone toners having low image surface gloss are preferred as the black toner. In addition, high-quality glossy images are preferred for full-color images such as presentations and photographs.
It is desired that the image on the sheet has good light transmittance.

[0005] In particular, miniaturized digital full-color printers, which have been actively developed in recent years, are disclosed in US Pat. Nos. 2,895,847 and 3152012, Japanese Patent Publication Nos. 41-9475 and 45-2877.
And non-magnetic one-component developing methods described in Japanese Patent Application Laid-Open Nos. 54-3624 and tandem method have attracted attention as a full-color image forming method corresponding to high speed. As the size and speed of printers are reduced, the size of developing devices, photoconductors, fixing devices, and the like is reduced, and the process speed tends to increase. Therefore, in the developing device, the charge application to the toner is reduced, the charge rising property is deteriorated, the toner fog on the photoreceptor is increased, the white background fog of the printed matter is generated, and the toner charge amount is reduced, so that the image is reduced. If the density is too high, the toner consumption may be deteriorated. Further, in the fixing device, the fixing member is reduced in size and the paper passing speed is increased, so that the fixing strength is lowered, and the fixing property is deteriorated, such as a phenomenon in which the paper is curled and wrapped around the fixing roll.

[0006] To improve these, Japanese Patent No. 284133 is disclosed.
No. 2 proposes to make the viscoelasticity of the three primary color toners different from that of the black toner, and Japanese Patent No. 2768181 proposes to make the amount of fixing heat different between black and white image formation and color image formation. Japanese Patent Application Laid-Open No. 8-2344491 proposes that the softening point and the like of a color toner and a black toner are made different. Examples of adding a wax include, for example, Japanese Patent Application Laid-Open Nos. 49-65231 and 49-65231. 58-162
No. 50, JP-A-50-27546, JP-A-55-15-15
No. 3,944, JP-A-9-73187 and the like have proposed the addition of a polyolefin wax such as polypropylene or polyethylene, but this has not been sufficient yet.

[0007]

Accordingly, the first aspect of the present invention is as follows.
The purpose of the present invention is to provide a sufficient charge imparting effect to the toner with a small developing device, a sufficient amount of charge can be secured by quickly charging, and unnecessary toner fog on the photoreceptor is reduced,
It is an object of the present invention to provide a full-color image forming method in which a printed matter does not have a stain on a white background portion and has good uniformity of a solid image. A second object of the present invention is to provide a full-color image forming method which has good durability when continuous printing is performed by a printer or the like, and stabilizes image characteristics such as image density and fog and toner consumption. A third object of the present invention is to provide a full-color image forming method which has good fixing performance such as sufficient fixing strength and no offset or curl phenomenon by heat fixing with a heating roll or the like. A fourth object of the present invention is to provide a good full-color image forming method capable of obtaining a glossy image having a high-quality color image with a matte image having a low image surface gloss as a black toner.

[0008]

The present inventors have made intensive studies in view of the above circumstances, and as a result, have found that the softening points of the three primary color toners and the black toner are different, and the addition amount of the polyolefin wax is the same or different. As a result, it has been found that the problems of the conventional full-color image forming method have been solved, and that the present invention has excellent characteristics, and the present invention has been completed. That is, the gist of the present invention is a full-color image forming method for forming a color image using a plurality of color toners and black toner,
The plurality of color toners and the black toner have at least a binder resin, a polyolefin wax, a colorant, and a charge control agent, and any of the softening temperatures of the plurality of color toners is lower than the softening temperature of the black toner. The present invention also provides a full-color image forming method, wherein the amount of the polyolefin wax in the plurality of color toners is equal to or greater than the amount of the polyolefin wax in the black toner.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the full-color image forming method, at least three colors of cyan, magenta, and yellow are used as color toners, but color toners of four or more colors can be used by adding other colors. Hereinafter, a case where three color toners of cyan, magenta, and yellow are used will be described. The toner particles used in the present invention are finely divided particles containing a polyester resin, a colorant, a negatively chargeable charge control agent, and other additives as necessary. The average particle diameter of the toner particles is usually 4 to 20.
μm, preferably 4 to 12 μm. The particle size of the toner can be measured, for example, with a Bolman Coulter Coulter Counter, Multisizer, or the like.

As the binder resin used in the present invention, various known styrene / acrylic resins, polyester resins, epoxy resins and urethane resins suitable for toners can be used, and particularly linear or non-linear polyester resins. Is preferred. Further, it is preferable that the binder resin for the three-color primary color toner is a linear or non-linear polyester resin and the binder resin for the black toner is a non-linear polyester resin. More preferably, the three-primary color polyester resin tetrahydrofuran (hereinafter, THF) is used. It is preferable that the insoluble content is smaller than the insoluble content of the black polyester resin. Polyester resin is excellent in terms of both mechanical strength and fixability, especially when used as a non-magnetic one-component toner. Non-linear polyester resin for black toner containing THF-insoluble component has low gloss. Preferably, the polyester resin for the three primary colors is a linear resin containing no THF-insoluble matter or a non-linear polyester resin containing a small amount of THF-insoluble matter because of its high gloss. It is to be noted that linear and non-linear polyester resins may be mixed and used for the three color primary color toners and the black toner polyester resin, and by adjusting the mixing ratio thereof, the toner molecular weight, the softening point, and the like can be adjusted within a suitable range. Can be controlled freely.

The polyester resin is composed of a polyhydric alcohol and a polybasic acid. If necessary, at least one of the polyhydric alcohol and the polybasic acid contains a trifunctional or higher polyfunctional component (crosslinking component). It is obtained by polymerizing the product. In the above, examples of the dihydric alcohol used for the synthesis of the polyester resin include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol,
3-propylene glycol, 1,4-butanediol,
Neopentyl glycol, 1,4-butenediol,
Diols such as 1,5-pentanediol and 1,6-hexanediol, bisphenol A, hydrogenated bisphenol A, polyoxyethylenated bisphenol A,
Examples thereof include bisphenol A alkylene oxide adducts such as polyoxypropylene-modified bisphenol A, and the like. Among these monomers, it is particularly preferable to use a bisphenol A alkylene oxide adduct as a main component monomer, and particularly preferably an adduct having an average number of addition of 2 to 7 alkylene oxides per molecule.

Examples of the trihydric or higher polyhydric alcohol involved in the crosslinking of polyester include sorbitol and
1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, sucrose, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol , 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, and the like.

On the other hand, polybasic acids include, for example, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid Examples thereof include acids, malonic acids, anhydrides of these acids, lower alkyl esters, alkenylsuccinic acids or alkylsuccinic acids such as n-dodecenylsuccinic acid and n-dodecylsuccinic acid, and other divalent organic acids. Examples of tribasic or higher polybasic acids involved in the crosslinking of polyester include 1,2,4-
Benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,2
4-naphthalenetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetra Carboxylic acids, their anhydrides, and others can be mentioned.

These polyester resins can be synthesized by an ordinary method. Specifically, the reaction temperature (1
Conditions such as 70 to 250 ° C.) and reaction pressure (5 mmHg to normal pressure) may be determined according to the reactivity of the monomer, and the reaction may be terminated when predetermined physical properties are obtained. The softening temperature (Sp) of these polyester resins is 80 to
The temperature is 160 ° C, and among them, the one at 90 to 150 ° C is more preferable. The glass transition temperature (Tg) is
The temperature is 50 to 75 ° C, and among them, the one having a temperature of 55 to 70 ° C is more preferable. In this case, when Sp is lower than the above range, an offset phenomenon at the time of fixing is likely to occur, and when Sp is higher than the above range, fixing energy increases, and glossiness and transparency tend to deteriorate with color toner, which is not preferable. . When the Tg is lower than the above range, the toner tends to aggregate and fix, and when the Tg is higher than the above range, the fixing strength at the time of thermal fixing tends to decrease, which is not preferable. S
p can be adjusted mainly by the molecular weight of the resin, and the number average molecular weight is preferably 2,000 to 20,000, more preferably 3,000 to 12,000. Also,
Tg can be adjusted mainly by selecting a monomer component constituting the resin, and specifically, Tg can be increased by using an aromatic polybasic acid as a main component as an acid component. That is, among the above-mentioned polybasic acids, phthalic acid, isophthalic acid, terephthalic acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid and the like, and anhydrides and lower alkyl esters thereof are used. It is desirable to use it as a main component.

THF-insoluble content of polyester resin (%)
Is obtained by extracting the resin sample (W ₁ ) with THF using a Soxhlet extractor for 6 hours and then weighing (W ₂ ) the remaining amount without being extracted after drying, and obtaining the formula (W ₂ /
W ₁ ) × 100 (%). Sp of the polyester resin was measured using a flow tester described in JIS K7210 and K6719. Using a flow tester (CFT-500, manufactured by Shimadzu Corporation), about 1 g of a sample was heated at a rate of 3 ° C./min. 1c while heating with
A load of 30 kg / cm ² was applied by a plunger of m ² , extruded from a die having a hole diameter of 1 mm and a height of 10 mm, and a temperature corresponding to an intermediate point between a descent start temperature and a descent end temperature of the plunger was defined as a softening temperature. is there. The Tg was measured using a differential scanning calorimeter (DSC) at a heating rate of 10
The measurement was performed at a temperature of ° C./min, and a temperature corresponding to an intersection where a tangent line was drawn at the inflection point (shoulder).

On the other hand, if the acid value of the polyester resin is too high, it is generally difficult to obtain a stable and high charge amount, and the charge stability at high temperature and high humidity tends to be deteriorated. The value is 30 KOHmg / g
It is better to be less than 25KOHmg /
g. As a method for adjusting the acid value within the above range, other than a method of controlling the addition ratio of the alcohol-based and acid-based monomers used in the resin synthesis, for example, the acid monomer component is previously converted to a lower alkyl ester by a transesterification method. And a method of neutralizing residual acid groups by adding a basic component such as an amino group-containing glycol to the composition, but not limited thereto. Needless to say, it can be adopted. In addition,
The acid value and hydroxyl value of the polyester resin are determined according to JIS K00.
It is measured according to the method of No. 70. However, when the resin is difficult to dissolve in the solvent, a good solvent such as dioxane may be used.

Among these polyester resins, resins having different components from among known polyester resins may be used alone or in combination of two or more, or resins having different viscoelastic properties and thermal properties such as different molecular weight distributions among resins of the same kind may be used. You may use individually or in combination of 2 or more types. Known resins such as styrene resins, styrene-acrylic copolymer resins, epoxy resins, and urethane resins other than polyester resins may be used in combination.
It is preferably at least 0% by weight.

Next, the polyolefin wax used in the present invention will be described. Examples of the polyolefin wax used in the present invention include polypropylene, polyethylene, polybutene, polyexene, ethylene-propylene copolymer, ethylene-butene copolymer, and the like, in particular, polypropylene, polyethylene, and ethylene-propylene copolymer. preferable. In addition, what is usually called a polypropylene wax and a polyethylene wax includes an oxidized type, a modified type, and an ethylene-propylene copolymer.

In the present invention, the addition amount (Wc) of the polyolefin wax in the cyan toner, the addition amount (Wm) of the polyolefin wax in the magenta toner, and the addition amount (Wm) of the polyolefin wax in the yellow toner
y) is set to be equal to or more than the addition amount (Wb) of the polyolefin wax in the black toner.

Further, in the present invention, the addition amount (Wc) of the polyolefin wax in the cyan toner, the addition amount (Wm) of the polyolefin wax in the magenta toner, and the addition amount (Wm) of the polyolefin wax in the yellow toner.
It is better that the composition y) exceeds the addition amount (Wb) of the polyolefin wax in the black toner, and Wc, Wm, Wy
Is preferably 0.2 parts by weight or more relative to Wb, and further, each of Wc, Wm and Wy is more than 0.2 parts by weight relative to Wb.
More preferably, it is at least 3 parts by weight. When the softening temperature (Tc, Tm, Ty) of the three primary color toners is lower than the softening temperature (Tb) of the black toner, the hot offset property of the three primary color toners is disadvantageous to that of the black toner. The hot offset property can be improved by increasing the number of three primary color toners compared to the black toner. Further, in the case of a non-magnetic one-component toner, a three-primary color toner using a colorless or light-colored charge control agent which does not affect the color tone of a toner having a lower softening temperature than a black toner has a poor charge rising property and a charge amount. The level tends to be low, the fogging of the photoreceptor and the white background are easily deteriorated, and the image density is apt to be excessively high. The level can be improved in a good direction.

Here, the added amount of the polyolefin wax (Wc, Wm, Wy, Wb) refers to the amount of the binder resin 1 respectively.
It means the added parts by weight of the polyolefin wax based on 00 parts by weight. In the present invention, two or more kinds of polyolefin waxes can be used in combination. In such a case, the total amount by weight of the polyolefin wax in each toner is used.

Wc, Wm, Wy and Wb are each set to 0.
The content is preferably 1 to 6 parts by weight, more preferably 0.2 to 5 parts by weight. If the addition amount is significantly lower than the above range, fogging on the photoreceptor and the white background stain on plain paper tend to deteriorate, and if the addition amount is significantly higher than the above range, a filming phenomenon on the photoreceptor and the developing member may occur. It tends to occur, and tends to cause poor transportability due to deterioration of toner fluidity. The number average molecular weight (Mn) of the polyolefin wax is preferably 1,000 to 10,000, and more preferably 2,000 to 1
Polypropylene wax having a number average molecular weight (Mn) of 1,000 to 7,000 or polypropylene wax having a number average molecular weight (Mn) of 1,000 to 7,000 is more preferable. When the Mn is significantly lower than the above range, the filming phenomenon on the photoconductor and the developing member tends to occur easily, and when the Mn is extremely high, the one-component charging characteristic is inferior, and the fog on the photoconductor and the white background stain on plain paper are reduced. The improvement effect tends to be hardly exhibited.

The melting point of the polyolefin wax is 7
The temperature is preferably 0 to 180 ° C, more preferably 80 to 160 ° C. If the melting point is significantly higher than the above range, the polyolefin wax will not be sufficiently melted even when heated at the time of production in a toner kneader or the like, and the compatibility and dispersibility in the resin will tend to be poor. The fixing temperature tends to deteriorate. On the other hand, if it is significantly lower than the above range, it is difficult to obtain a shear when the toner is manufactured by a toner kneader or the like, and the dispersibility of the colorant and other internal additives tends to deteriorate.

The molecular weight of the polyolefin wax is determined by a high-temperature gel permission chromatography (hereinafter, referred to as "high-performance gel permission chromatography").
GPC), and there are some differences depending on the measurement conditions. For example, the measurement can be performed under the following conditions. That is, at a temperature of 135 ° C.,
Using dichlorobenzene (added with 0.1% ionomer), flow at a flow rate of 1 ml / min, and inject 400 μl of a 0.1% by weight sample solution to measure. In measuring the molecular weight of the sample, a value in terms of polystyrene is used from a calibration curve prepared using a monodisperse polystyrene standard sample. The column to be used is not limited at all, but for example, A-80M manufactured by Shodex Co., Ltd. is used.

The melting point of the polyolefin wax is determined from an endothermic pattern of thermal analysis (differential thermal analyzer, differential scanning calorimeter, etc.), and the peak position temperature is defined as the melting point. In the toner of the present invention, each of the three primary color toners of cyan, magenta and yellow and the black toner contains a polypropylene wax or an ethylene propylene copolymer wax, and the number average of the polyolefin waxes of the three primary color toners is included in these polyolefin waxes. Molecular weight (Mn
c, Mnm and Mny) are preferably lower than the number average molecular weight (Mnb) of the polyolefin wax of the black toner.

As the colorant used in the black toner of the present invention, various known dyes and pigments such as carbon black, magnetite, and aniline black can be used. When used in a magnetic toner, magnetite is preferred. Particularly, when used in a non-magnetic one-component negatively chargeable toner, acidic carbon black is preferred. The term “acidic” means that the value obtained by measuring the pH of a suspension obtained by boiling carbon black and pure water is 6%. Refers to the following, more preferably 5
The following are preferred. Except for the acidic carbon black, the charge characteristics of the negative charge tend not to be improved.

The carbon black of the present invention is preferably produced by a furnace method. Specific surface area of carbon black by nitrogen adsorption by BET method is 20 to 500 m
² / g and dibutyl phthalate (DBP) oil absorption of 30
Those having a range of about 150 ml / 100 g are preferable.
If the BET specific surface area is significantly smaller than the above range, the particles become too large and the dispersibility of the carbon black tends to deteriorate, and if the BET specific surface area is significantly larger than the above range, the particles are difficult to apply when kneaded finely and the carbon black is dispersed. It tends to be bad. Carburn black may be subjected to surface treatment with metal soap or the like, if necessary, for the purpose of surface modification, or untreated and surface-treated one may be used in combination.

As the coloring material of the three primary colors (cyan, magenta, and yellow) toners of the present invention, various known dyes and pigments can be used. The following are examples. As the yellow toner, C.I. I. Pigment Yellow 1, 3, 74, 97, 98
Acetoacetic acid arylamide monoazo yellow pigments such as
C. I. Pigment Yellow 12, 13 and 14,
Azoacetate arylamide-based disazo yellow pigments such as those described in No. 17; I. Condensed monoazo yellow pigments such as CI Pigment Yellow 93 and 155; I. Other yellow pigments such as CI Pigment Yellow 180, 150 and 185;
C. I. Solvent Yellow 19, 77, 79
C. I. Examples include yellow dyes such as Disperse Yellow 164. As magenta toner, C.I. I. Pigment Red 48, 49: 1, 53: 1, 5
7, the same 57: 1, the same 81, the same 122, the same 5, the same 146,
184, 238; C.I. I. Red or red pigments such as CI Pigment Violet 19; I. Red dyes such as Solvent Red 49, 52, 58, and 8 can be exemplified. As the cyan toner, C.I. I. Pigment Blue 15: 3, 15: 4, etc., blue colourants of copper phthalocyanine and derivatives thereof; I. Pigment Green 7, 36 (phthalocyanine green)
And other green pigments.

Of these, cyan toner has C.I. I.
Pigment Blue 15: 3 and 15: 4 blue pigments are preferred. For magenta toner, magenta: C.I. I. Pigment Red 57: 1, 122, 146, 1
Red and red pigments of Pigment Violet 84, Pigment Violet 238 and Pigment Violet 19 are preferable. I. Pigment Yellow 13, 1
7, 74, 93, 150, 155, 180,
185 yellow pigments are preferred. These colorants for color may be used alone or in combination of two or more.
The amount of the colorant to be used is preferably about 1 to 15 parts by weight, more preferably 2 to 10 parts by weight, based on 100 parts by weight of the binder resin.

As the charge control agent used in the present invention, various kinds of known charge control agents can be used in order to impart a negative charge property and a positive charge property to the toner. Chromium azo complex dye, iron azo complex dye, cobalt azo complex dye, chromium-zinc-aluminum-boron complex or salt compound of salicylic acid or a derivative thereof as a charge control agent for negatively charged toner,
Chromium-zinc-aluminum-boron complex or salt compound of naphtholic acid or its derivative, chromium-zinc-aluminum-boron complex or salt compound of benzylic acid or its derivative, long-chain alkyl carboxylate, long-chain alkyl sulfonic acid Surfactants such as salts, as a charge control agent for positively charged toner, nigrosine dye and its derivatives, triphenylmethane derivative,
Derivatives such as quaternary ammonium salts, quaternary phosphonium salts, quaternary pyridinium salts, guanidine salts and amidine salts are exemplified. These charge control agents may be used alone or in combination of two or more. However, as the charge control agent used for the three primary color toners, those which do not affect the color tone and are close to colorless or pale are preferred.

The addition amount of the charge control agent is preferably 0.05 to 8 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the binder resin. Further, as the charge control agent, a negatively chargeable charge control agent is preferable because the effect of the present invention can be effectively exhibited. The charge control agent in the present invention is a boron-based charge control agent, particularly a compound represented by the following general formula [I], as a charge control agent for the three primary color toners of cyan, magenta and yellow, and a charge control agent for a black toner. As such, an azo metal compound is advantageously used.

[0032]

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(Wherein R ₁ and R _{4 each} represent a hydrogen atom, an alkyl group, a substituted or unsubstituted aromatic ring (including a condensed ring), and X ⁺ represents a cation). R _{1 to} R ₄ represent a hydrocarbon group which may be substituted, and specific examples of the hydrocarbon group include a methyl group, an ethyl group, a propylene group,
Examples thereof include an alkyl group such as an isopropyl group, a cycloalkyl group such as a cyclohexyl group and a cyclopentyl group, an alkenyl group such as a vinyl group and an allyl group, and an aromatic hydrocarbon group such as a phenyl group and a naphthyl group. These hydrocarbons may be substituted, but the substituent may be a halogen atom, a hydroxyl group, a sialic group, an alkyl group, an alkenyl group,
Alkoxy groups are preferred.

Preferably, at least two of R _{1 to} R ₄ are aromatic hydrocarbon groups and X ⁺ is an alkali metal ion. Further, commercially available products include LR-147 manufactured by Nippon Carlit Co. It is particularly preferred that the known compounds, ie R _{1 to} R _4, are all phenyl groups and X ⁺ is a potassium ion. The addition amount of the charge control agent of the boron compound is preferably 0.05 to 8 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the binder resin.

As the metal component of the azo-based metal compound used for the charge control agent of the black toner, chromium or iron is preferable. The addition amount of the charge control agent of these azo-based metal compounds may be 0.0 to 100 parts by weight of the binder resin.
The amount is preferably 5 to 10 parts by weight, more preferably 0.1 to 6 parts by weight. Further, as the chromium-azo compound used in the present invention, those represented by the following general formula [II] are preferable, and commercially available compounds include, for example, Bontron S-34 manufactured by Orient Chemical Industry Co., Ltd. S-54 and T-95 manufactured by Hodogaya Chemical Industry Co., Ltd. are known.

[0036]

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(Wherein, A to D may be the same or different and each represents an optionally substituted benzene ring.
X ⁺ represents a cation. In the general formula [II], the substituent of the benzene ring of A to D is preferably an alkyl group, a halogen atom, a cyano group, a nitro group, a hydroxyl group, or an alkoxy group, and more preferably a chlorine atom. X ⁺ represents a cation, and is preferably a hydrogen ion, an alkali metal ion, or an ammonium ion. Further, as the iron-azo compound used in the present invention, a compound represented by the following general formula [III] is preferable,
As a commercially available product, for example, T-77 manufactured by Hodogaya Chemical Industry Co., Ltd. is known.

[0038]

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(Wherein EJ may be the same or different and represent an optionally substituted benzene ring.
X ⁺ represents a cation. In the general formula [III], when the benzene ring of E to J has a substituent, a halogen atom,
Sulfonamide group, mesyl group, sulfonic acid group, hydroxyl group,
Represents an amino group, an alkoxycarbonyl group, an acetylamino group, a benzoylamino group, an optionally substituted hydrocarbon group, or an optionally substituted alkoxy group, wherein the substituent is an alkyl group, an alkenyl group, a halogen atom, A cyano group, a hydroxyl group, an amino group and a nitro group are preferred, a halogen atom and an alkoxy group are more preferred, and a chlorine atom and a methoxy group are particularly preferred. X ⁺ represents a cation, preferably a hydrogen ion, an alkali metal ion, or an ammonium ion, and more preferably a sodium ion or a potassium ion.

In order to improve the dispersibility and compatibility in the toner, the coloring agent and the charge controlling agent are preliminarily dispersed by pre-kneading with a resin, so-called master batch treatment, or the pigment dispersion after the pigment formation reaction. A high-concentration pigment dispersion treatment, that is, a so-called flushing treatment may be performed by adding a resin to the liquid and replacing and mixing the resin with the dispersion medium at the time of pigment production. By dispersing the pigment particle diameter in these processed products to about half wavelength (200 nm) of visible light, transparency of a color image and the like can be made advantageous. Further, the particle size of the treated product itself is preferably the same as the particle size of the binder resin. If the particle size is too large, the colorant in the toner tends to be unevenly distributed during continuous production. In general, the particle size of the master batch-treated product and the flushing-processed product is preferably one that has passed through a sieve having an opening of 3 mm, and preferably has passed a sieve having an opening of 2 mm or less. In the present invention, various known organic or inorganic fine particle powders may be used as additives for the purpose of improving the adhesiveness, cohesiveness, fluidity, chargeability, surface resistance and the like of the toner.

As the fine powder to be added to the toner surface, that is, the so-called external additive, at least a silane coupling agent and an inorganic fine powder surface-treated with silicone oil are preferable. These surface treatment agents add hydrophobicity, fluidity, and chargeability to the inorganic fine powder, so that the non-magnetic one-component toner has good negative charge buildup and good charge characteristics can be obtained. As the core of the inorganic fine powder, silica, titania, alumina, zinc oxide, magnesium oxide, magnetite, ferrite, and the like, which can be used by a known wet or dry method, can be used, but silica, titania, and alumina are preferably used. And more preferably silica. In the case of a non-magnetic one-component toner, one kind of inorganic fine powder may be used, but it is preferable to use two or more kinds having different particle sizes in combination.

In particular, when two or more inorganic fine powders are used together in a non-magnetic one-component negatively chargeable toner, the relatively coarse inorganic fine powder (a) and the relatively fine inorganic fine powder (b) are used. In this case, at least one of the inorganic fine powders may be surface-treated with silicone oil. The size of the coarse inorganic fine powder (a) is preferably less than 80 m ² / g by the BET specific surface area,
More preferably suitable 5~79m ² / g, the fine inorganic fine powder (b) magnitude BET specific surface area of 80 m ²
/ G or more, more preferably 80 to 500 m ^2.
/ G is preferred. Further, it is more preferable that the surface treating agent of the inorganic fine powder (a) is silicon oil and the surface treating agent of the inorganic fine powder (b) is silicone oil or a coupling agent.

The relatively coarse inorganic powder (a) improves the anti-blocking property of the toner, and the toner particles in the developing tank and between the toner particles and the developing tank constituent members (wall, developing roll, layer thickness regulating member, etc.) ), Suppression of fine pulverization of toner by mechanical impact relaxation, suppression of embedding of external additives, prevention of filming on photoreceptor, suppression of adhesion phenomenon to toner layer thickness regulating member, etc. It is presumed that the toner has excellent storage stability due to these effects, and the durability performance is improved even when used in continuous printing, such as image deterioration, and in-machine contamination due to toner scattering and leakage. When the BET specific surface area is 80 m ² / g or more, the role of the inorganic fine powder (a) as a partition wall between the toner and the developing tank member is hardly exhibited, the blocking resistance is deteriorated, and the continuous printing is not performed. Durability tends to deteriorate. The use of silicone oil as a surface treatment agent for the inorganic fine powder (a) is preferable because it imparts a hydrophobizing function to improve environmental dependency and does not easily inhibit the chargeability of the toner. In the case of the inorganic fine powder (a) treated with silicon oil, the charge rise of the negatively charged toner is improved, and the fog on the photoreceptor and the fog on the plain paper white background are improved. Surface treatment agents other than silicone oil tend to inhibit the charging characteristics of the toner.

It is presumed that the relatively fine inorganic fine powder (b) has the effects of improving the fluidity of the toner and the transportability of the toner in the developing tank. Is excellent, the toner layer in the developing section is uniform,
A high quality printed matter such as a dense, uniform and good image portion can be obtained. When the BET specific surface area is less than 80 m ² / g, the effect of improving the fluidity of the inorganic fine powder (b) in the toner is weakened, and the toner replenishing property is deteriorated, so that a high-quality printed matter tends not to be obtained. As a surface treating agent for the inorganic fine powder (b), a hydrophobic function using a silane coupling agent or silicone oil is imparted to improve the environmental dependence and to be excellent in the fluidity improving function of the inorganic fine powder. .
Surface treatment agents other than silane coupling agents or silicone oils tend to have poor fluidity improving functions.

The cores of the inorganic fine powder (a) and the inorganic fine powder (b) may be of the same type or different types. A conventionally known method is used for the surface treatment of the inorganic fine powder with silicone oil. For example, as silicone oil, dimethyl silicone oil, methylphenyl silicone oil, methyl hydrogen silicone oil, and modified silicon which are common straight silicone oils are used. Oils include methacrylic acid-modified silicone oil, epoxy-modified silicone oil, fluorine-modified silicone oil, polyether-modified silicone oil, amino-modified silicone oil, etc.
It is used in one kind or in a mixture of two or more kinds. Preferably, the silicone oil is a straight silicone oil, of which dimethyl silicone oil is preferred.

The surface treatment of the inorganic fine powder with a silane coupling agent may also be performed by a conventionally known method. For example, organosilanes such as methoxytrimethylsilane, dimethoxyalkoxylan, trimethoxymethylsilane, ethoxytrimethyl Silanes), organochlorosilanes (trichloromethylsilane, dichlorodimethylsilane, chlorotrimethylsilane, trichloroethylsilane, dichlorodiethylsilane, chlorotriethylsilane, trichlorophenylsilane, etc.), and organosilazanes (triethylsilazane, tripropylsilazane) , Triphenylsilazane, hexamethyldisilazane, hexaethyldisilazane, hexaphenyldisilazane, etc.), organodisilazane, organosilane and the like. Used in the seed or in combination of two or more. Preferred as the silane coupling agent are organochlorosilane and organosilazane.
Alternatively, the surface treatment of the silicon oil may be performed after the treatment with the silane coupling agent, or the surface treatment of the silicon oil may be used in combination with the silane coupling agent.

The BET specific surface area of the inorganic fine powder can be measured using a commercially available BET specific surface area measuring apparatus by nitrogen adsorption. For example, a fluid type specific surface area automatic measuring apparatus manufactured by Shimadzu Corporation (Flow soap 2300
Shape). The average particle size of the inorganic fine powder may be determined by measuring the particle size from an image taken at a high magnification (for example, 50,000 or more) at which the particles can be identified with a transmission electron microscope.

With respect to the added parts by weight (W ₀ ) of the inorganic fine powder as an external additive, the coverage f when the toner particles are 100 parts by weight is preferably 20 to 400%, and more preferably 30 to 300%.
% Is preferred. When used in combination of two or inorganic fine powder of the total added weight sum of added parts by weight (W _b) of the added parts by weight (W _a) and fine inorganic fine powder (b) of coarse inorganic fine powder (a) The unit may be W ₀ . The total added parts by weight (W ₀ )
If the amount is significantly less than this range, the original effect of the inorganic fine powder tends not to be exhibited.If the amount is extremely large, filming of the photoreceptor is likely to occur, and image defects such as fog on the photoreceptor and fog on plain white paper are likely to deteriorate. Tend to be easily caused. Further, the addition weight part (W) of the inorganic fine powder (a)
added parts by weight of _a) and inorganic fine powder _(b) (W b) is, W _a
There W preferably it can be exhibited strongly relatively coarse inorganic fine powder effect more than it is non-magnetic one-component toner _b, or more preferably W _a is 0.2 which is parts by versatile than W _b. As the added parts by weight of the inorganic fine powder (a) and the inorganic fine powder (b), the coverage f of each is calculated independently, and the coverage is f ≦ 300, preferably f ≦ 200. If it is more than this, it is difficult to exert the respective effects of the inorganic fine powders (a) and (b), and it tends to cause image defects and the like. The coverage f when one kind of inorganic fine powder is mixed with the toner particles is calculated by the following formula [I].

[0049]

(Equation 1)

In the formula [I], f is the coverage (%), D _t
Is the volume average particle diameter (μm) of the toner particles, d _a and d ₀ are the average particle diameters (μm) of the inorganic fine powder, and ρ _t and ρ ₀ are the true specific gravities of the toner particles and the inorganic fine powder. The coverage f when two types of inorganic fine powders (a) and (b) are mixed with toner particles is calculated by the following equation [II].

[0051]

(Equation 2)

In the formula [II], f is the coverage (%), D _t
The volume average particle diameter of the toner particles _{(μm), d a, d} b is the inorganic fine powder (a), each having an average particle diameter of the inorganic fine powder (b) (μm), ρ t, ρ a, ρ b is The true specific gravity of each of the toner particles, the inorganic fine powder (a) and the inorganic fine powder (b) is used. As other external additives of the toner, various known organic and inorganic fine particles for the purpose of a resistance adjusting agent, an abrasive, a charge adjusting agent, and the like, for example, fluorine-based resin powders such as polyvinylidene fluoride and polytetrafluoroethylene. , Zinc stearate, fatty acid metal salts such as calcium stearate, resin beads mainly containing polymethyl methacrylate or silicone resin, minerals such as talc, hydrotalcite, ferroelectric fine powder such as strontium titanate, Examples include conductive fine powder such as conductive titania. These amounts are preferably from 0.01 to 10 parts by weight based on 100 parts by weight of the toner particles.

The non-magnetic toner according to the present invention can be manufactured by various manufacturing methods including a conventionally known method, and the following examples are given as general manufacturing methods. (1) A resin, a charge control substance, a colorant, and additives to be added as needed are uniformly dispersed in a mixing apparatus having a rotating section such as a blade or a screw. As the mixing apparatus, a Henschel mixer manufactured by Mitsui Mining Co., a Ladige mixer manufactured by Matsubo, a Nauta mixer manufactured by Hosokawa Micron, a super mixer manufactured by Kawata, or a general V-type mixer in which the container itself rotates can be used. . (2) Melt and knead the dispersion with a kneader, extruder, roll mill or the like. As a kneading apparatus, a continuous extruder, for example, a ZSP extruder manufactured by W & P, a kneader manufactured by BUSS, a TEM extruder manufactured by Toshiba Machine Co., Ltd., a PC manufactured by Ikegai Co., Ltd.
General batch-type kneaders such as an M-type extruder and Kneedex manufactured by Mitsui Mining Co., Ltd. can also be used. As a cooling device after the kneading, a drum cooler manufactured by Mitsui Mining Co./Mitsubishi Chemical Engineering Co., Ltd., a belt cooler manufactured by NBC Co., etc. can be used.

(3) The kneaded material is roughly pulverized by a coarse pulverizer and then finely pulverized by a fine pulverizer. Examples of the pulverizer include a type I / IDS type jet mill manufactured by NPK and an AFG manufactured by Hosokawa Micron.
-Jet mills such as TJM; Hosokawa Micron's Hammer Mill, Fats Mill, Feather Mill, Inomaizer, ACM Pulperizer, Turbo Mill's Turbo Mill, Kawasaki Heavy Industries' KTM, Nisshin Engineering's Super Rotor, NPK's Fine Using an impact-type pulverizer such as a mill or the like, pulverization is performed stepwise to a predetermined toner particle size. (4) Classify the finely pulverized material with a classifier. As a classifier, an air flow classifier having a rotary rotor in the machine, such as Alpine / Hosokawa Micron TSP, Nisshin Engineering Co., Ltd., Turboxifier, Condax / Mitsui Mining Co., CFS-HD, Donaldson Co., Ltd. Donasex, etc. NPK
The toner is classified stepwise to a predetermined toner particle size using a DS / DSX type classifier manufactured by Nippon Steel Co., Ltd., an elbow jet classifier manufactured by Nittetsu Mining Co., Ltd., or a micron separator manufactured by Hosokawa Micron Corporation. The coarse powder generated in the classification step may be reused after returning to the pulverization step or the first-stage classification step. Further, the toner fine powder may be reused by returning to the raw material mixing step and the kneading step.

(5) In the case of further external addition treatment, a predetermined amount of the classified product and various known external additives are blended, and the mixture is stirred by a high-speed stirrer such as a Henschel mixer or a super mixer, which applies a shearing force to the powder.・ Mix. (6) Gyro shifter to remove foreign matter and coarse particles,
After sieving using a vibrating sieve such as an Sato vibrating sieve or an ultrasonic sieve or a rotary sieve such as a turbo screener, a final toner can be obtained.

Further, as a method completely different from the above-mentioned production method, for example, toner particles may be formed by a production method using a suspension polymerization method or an emulsion polymerization method, that is, a so-called polymerization toner method. The obtained toner preferably has a softening temperature of 80 to 160 ° C and a glass transition temperature of 50 to 75 ° C. If the softening temperature is lower than 80 ° C., the hot offset property deteriorates,
Mechanical strength is weakened, which is not preferable. On the other hand, when the temperature exceeds 160 ° C., fixing property is deteriorated, which is not preferable. If the glass transition temperature is lower than 50 ° C., toner aggregation and fixation are likely to occur.
If the temperature exceeds ℃, the fixing strength is undesirably lowered. In the present invention, the softening temperature (Tc,
Tm, Ty) is 80 to 160 ° C., and the softening temperature (Tb) of the black toner is 80 to 160 ° C .;
, Tm, and Ty are lower than Tb, and more preferably have a difference of 3 ° C. or more, and more preferably a difference of 3 ° C. or more and 30 ° C. or less. If the softening temperature of the black toner is lower, a high gloss color image and a low gloss black image cannot be obtained, which is not preferable.

The softening temperature of the toner was measured using a flow tester (C
FT-500, manufactured by Shimadzu Corporation), and about 1 g of a sample was heated at a rate of 6 ° C./min. 1cm ² while heating with
A load of 20 kg / cm ² by the plunger of
It is extruded from a die having a hole diameter of 1 mm and a height of 1 mm, and a temperature corresponding to an intermediate point between the temperature at which the plunger starts to descend and the temperature at which it descends is defined as the softening temperature. Further, the glass transition temperature of the toner was once raised to 100 ° C. or more at a rate of 10 ° C./min using a differential scanning calorimeter (DSC).
It is cooled to room temperature by air cooling with a fan, and is again set to a temperature corresponding to an intersection where a tangent is drawn to an inflection point (shoulder) when the temperature is raised again.

The reason why the toner of the present invention exhibits excellent effects is not necessarily clear, but is considered as follows. First, the color toner is required to have transparency because it may produce a color by mixing a plurality of colors and to ensure transparency during OHP projection. Therefore, it is advantageous to use a toner having a relatively low softening temperature. is there. On the other hand, black is a single color and does not require transparency because it produces black. Rather, it is advantageous to use a toner having a relatively high softening temperature to produce low gloss black. In particular, in the case of fixing by the constant heating contact method under the same heat fixing condition, in the case of a toner having a low softening temperature (color toner), it is necessary to use a relatively large amount of polyolefin wax in order to improve hot offset.
In a toner having a high softening temperature (black toner), the hot offset is good, so the addition of a relatively small amount of wax is sufficient, and the filming phenomenon and the deterioration of fluidity, which are adverse effects when a large amount of wax is used, are required. Is less likely to cause transport failure. That is, it can be said that the configuration of the present invention satisfies the balance between the performance required for the color toner and the performance required for the black toner in forming a full-color image.

The toner used in the full-color image forming method of the present invention may be used as a two-component developer obtained by mixing a toner and a magnetic carrier, or may be used as a one-component toner using no magnetic carrier. In particular, it is preferably used for a one-component toner, and more preferably used for a non-magnetic one-component toner. The full-color image forming method of the present invention is an electrophotographic method in which an image is formed by a thermal fixing method in which a toner is developed by a contact or non-contact non-magnetic one-component developing method, and then the toner is brought into contact with a fixing roll having a built-in heat heater to fix the toner. This is particularly effective when used in a recording device. That is, since the color toners of a plurality of colors may be fixed at once by the fixing roll, it is further required to set the softening temperature of the color toners lower. However, according to the configuration of the present invention, sufficient fixing strength can be obtained. It has a useful fixing effect, such as no offset phenomenon on the low and high temperature sides and no phenomenon that the recording paper is wound around the heat roll. Further, the tandem type full-color image forming method has a feature that the printing speed can be increased as compared with the intermediate transfer method, the multiple transfer method, and the like. Therefore, as the toner used in the tandem system, a toner having a quick charge rising property, an appropriate charge amount can be secured, the toner fog on the photoconductor is small, the uniformity of a solid image is good, and the toner consumption is not deteriorated. It was desired, but not always enough. Therefore, the above problem can be solved by using the toner of the present invention in a tandem system.

Hereinafter, an electrophotographic recording apparatus using a non-magnetic one-component toner, which is an example of the full-color image forming method of the present invention, will be described. However, the present invention is not limited to this example. FIG. 1 is a schematic diagram of a main configuration of an electrophotographic recording apparatus, and includes a photoconductor 1, a charging device 2, an exposure device 3, a developing device 4, a transfer device 5, a cleaning device 6, and a fixing device 7.
have. The photoreceptor 1 is formed of a conductor such as aluminum, for example, and has a photosensitive layer formed by applying a photosensitive conductive material on the outer peripheral surface. A charging device 2, an exposure device 3, a developing device 4, a transfer device 5 along the outer peripheral surface of the photoconductor 1.
Further, a cleaning device 6 is arranged.

The charging device 2 includes, for example, a well-known scorotron charger, roller charger, and the like, and uniformly charges the surface of the photoconductor 1 to a predetermined potential. The exposure device 3 includes the photoconductor 1
The photosensitive surface of the photosensitive member 1 is exposed by an LED, a laser beam, or the like to form an electrostatic latent image on the photosensitive surface. The developing device 4 includes an agitator 42, a supply roller 43, a developing roller 44, and a regulating member 45.
Is stored. If necessary, the developing device may be provided with a replenishing device 41 for replenishing toner, and the replenishing device can replenish toner from containers such as bottles and cartridges. The supply roller 43 is made of a conductive sponge or the like, and is in contact with the developing roller 44. The developing roller 44 is disposed between the photoconductor 1 and the supply roller 43. Developing roller 44
Are in contact with the photoconductor 1 and the supply roller 43, respectively. The supply roller 43 and the developing roller 44 are rotated by a rotation drive mechanism. The supply roller 43 carries the stored toner and supplies it to the developing roller 44. The developing roller 44 carries the toner supplied by the supply roller 43 and contacts the surface of the photoconductor 1.

The developing roller 44 is made of iron, stainless steel,
It is made of a metal roll of aluminum, nickel, or the like, or a resin roll in which a metal roll is coated with a silicon resin, a urethane resin, a fluororesin, or the like. The surface of the developing roll is
If necessary, the surface may be smoothed or roughened. The regulating member 45 includes a resin blade such as a silicone resin or a urethane resin, stainless steel, aluminum, copper,
It is formed of a metal blade such as brass or phosphor bronze, a blade obtained by coating a metal blade with a resin, or the like. The regulating member 45 is in contact with the developing roller 44 and is pressed against the developing roller 44 by a predetermined force (a general blade linear pressure is 5 to 500 g / cm) by a spring or the like. A function of imparting charge to the toner by frictional charging may be provided.

The agitator 42 is rotated by a rotation drive mechanism, and agitates the toner and conveys the toner to the supply roller 43 side. A plurality of agitators may be provided with different blade shapes, sizes, and the like.
The transfer device 5 includes a transfer charger, a transfer roller, a transfer belt, and the like that are arranged to face the photoconductor 1. The transfer device 5 applies a predetermined voltage value (transfer voltage) having a polarity opposite to the charged potential of the toner, and transfers the toner image formed on the photoconductor 1 to the recording paper P.

The cleaning device 6 comprises a cleaning member such as a urethane blade or a fur brush.
The cleaning device removes the residual toner attached to the photoreceptor 1 and collects the residual toner. The fixing device 7 includes an upper fixing member 71 and a lower fixing member 72, and a heating device 73 is provided inside the upper or lower fixing member.
have. As the fixing member, a known heat fixing member such as a fixing roll in which a metal tube made of stainless steel, aluminum or the like is coated with silicone rubber, a fixing roll in which Teflon resin is coated, a fixing sheet, or the like can be used. Further, a releasing agent such as silicone oil may be supplied to the fixing member to improve the releasing property. Further, a mechanism for forcibly applying pressure to the upper fixing member and the lower fixing member by a spring or the like may be employed. When the toner transferred onto the paper P passes between the upper fixing member 71 and the lower fixing member 72 heated to a predetermined temperature, the toner is heated to a molten state, cooled after passing through, and cooled on the recording paper P. Is fixed to the toner.

In the electrophotographic developing apparatus configured as described above, an image is recorded as follows. That is, first, the surface (photosensitive surface) of the photoconductor 1 is charged to a predetermined potential (for example, −600 V) by the charging device 2. continue,
The charged photosensitive surface of the photoreceptor 1 is exposed by the exposure device 3 in accordance with an image to be recorded, and an electrostatic latent image is formed on the photosensitive surface. Then, the developing device 4 develops the electrostatic latent image formed on the photosensitive surface of the photosensitive member 1. In the developing device 4, the toner supplied by the supply roller 43 is thinned by the developing blade 45, and is triboelectrically charged to a predetermined polarity (here, the same polarity as the charging potential of the photoreceptor 1, and negative polarity). Then, it is carried on the developing roller 44, transported, and brought into contact with the surface of the photoconductor 1.

From the developing roller 44, a toner image corresponding to the electrostatic latent image is formed on the surface of the photoreceptor 1 by a so-called reversal developing method. Then, the toner image is transferred to the sheet P by the transfer device 5. Thereafter, the toner remaining on the photosensitive surface of the photoconductor 1 without being transferred is removed by the cleaning device 6. The final image is obtained by passing the toner on the recording paper P through the fixing device 7 and thermally fixing the toner. Next, an example of a tandem type electrophotographic recording apparatus using a non-magnetic one-component toner as a full color will be described. FIG. 2 is a schematic diagram of a main structure of a full-color tandem system, which includes a photosensitive member 1, a charging device 2, an exposure device 3, a black developing device 4k, a cyan developing device 4c, a yellow developing device 4y, a magenta developing device 4m, and a transfer device 5. , And a fixing device 7, and a cleaning device is omitted here. A color image can be obtained by superimposing magenta, yellow, cyan, and black toners in multiple layers and adjusting the color to a desired color. In the case of the tandem method, it is better that the color developing unit is located before the black developing unit, and that color mixing due to reverse transfer of black toner is reduced, and that the black developing unit is located behind the color developing unit is only black. In the case of forming an image with a single color, it is preferable since the color mixture due to the fog of the photoreceptor of the color toner is reduced, and the speed of black image formation can be increased by conveying the recording paper by short-passing the color developing section. The toner of the present invention is suitable for a tandem system in which such cyan, magenta, and yellow color developing units are located at the front, and the black developing unit is located after the color developing unit. Note that cyan, magenta,
The order in which the yellow color developing units are located can be freely changed at any time.

[0067]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the invention. In addition, in each of Examples and Comparative Examples, “parts” simply means “parts by weight”. The results of Examples and Comparative Examples are summarized in the first section.
The results are shown in Table 2 and Table 2.

[0068]

Example 1 <Preparation of Black Toner K1> Nonlinear polyester resin A1 100 parts Sp: 150 ° C., Tg: 65 ° C. THF insolubles: 20% Acid value: 8 KOHmg / g, Hydroxyl value: 30 KOHmg / g Mn: 2,400, Mw: 87,000 ・ 0.5 parts of polyethylene wax a [Mn: 6000, melting point: 133 ° C., density 0.96 kg / m ³ ] ・ Carbon black 5 parts of MA77 manufactured by Mitsubishi Chemical Corporation [pH 3] .0] ・ Charge control agent S-34 manufactured by Orient Chemical Co., Ltd. 1 part [Chrome azo complex dye]

The above composition is premixed by a high-speed stirrer, kneaded by a twin-screw continuous extruder, and then rapidly cooled while rolling with two rolls. The cooled material was coarsely powdered by a feather mill until it passed the 2 mm line, and then adjusted to a volume average particle size of about 8.7 μm by a jet pulverizer / airflow classifier to obtain a classified toner. The particle size was measured with a Beckman Coulter Multisizer. The softening temperature (Tb) of this toner was 140 ° C. and Tg was 65 ° C. Then
100 parts of the classified toner and 1.8 parts of RY50 silica manufactured by Nippon Aerosil Co., Ltd. were mixed with a Henschel mixer, and 0.2 part of R974 silica manufactured by Nippon Aerosil Co., Ltd. were further added and mixed to prepare a black toner K1.

[0070]

<Preparation of Cyan Toner C1> • 100 parts of linear polyester resin B1 Sp: 110 ° C., Tg: 65 ° C. THF insoluble matter: 0% Acid value: 7 KOH mg / g, Hydroxyl value: 30 KOH mg / g Mn: 4, 400, Mw: 45,000 ・ 1 part of polyethylene wax b [Mn: 3,000, melting point: 129 ° C., density: 0.95 kg / m ³ ] ・ 2 parts of polypropylene wax p [Mn: 3,000, melting point: 132] ° C, density: 0.89 kg / m ³ ] 7 parts of cyan master batch pigment Cyan pigment C.I. I. Pigment Blue 15: 3 40 parts and polyester resin B1 60 parts subjected to masterbatch treatment ・ Charge control agent LR-147 2 parts manufactured by Nippon Carlit Co. Black K1 except that the formulation of black K1 is as described above
Cyan toner C1 was adjusted in the same manner as in Example 1. The softening temperature (Tc) of this toner was 108 ° C. and Tg was 65 ° C.

[0071]

[Table 3] <Preparation of magenta toner M1> 9 parts of magenta master batch pigment I. Pigment Red 57: 1 40 parts and polyester resin B1 60 parts masterbatch processed

A magenta toner M1 was prepared in the same manner as in cyan C1, except that the cyan C1 master batch pigment was changed from cyan to the above-mentioned magenta. The softening temperature (Tm) of this toner was 107 ° C. and Tg was 65 ° C.

[0073]

<Preparation of Yellow Toner Y1> 9 parts of yellow master batch pigment I. Pigment Yellow 185 and polyester resin B1 with masterbatch treatment of 60 parts

A yellow toner Y1 was prepared in the same manner as in cyan C1, except that the cyan C1 master batch pigment was changed from cyan to the yellow color. The softening temperature (Ty) of this toner was 107 ° C. and Tg was 65 ° C. Using these K1, C1, M1, and Y1 toners, a commercially available tandem mechanism full-color printer A (color speed of A4 plain paper: 8 sheets / minute; non-magnetic one-component contact developing system for both primary and black toners; The order is yellow, magenta, cyan, and black; the photoreceptor is an organic photoconductor; the fixing temperature of plain paper is 170 ° C. by a hot roll fixing method), and the image characteristics at the initial stage, and the images at the time of continuous actual shooting of 1500 sheets As a result of evaluating the characteristics, all were excellent and good.

[0075]

[Example 5] <Production of toner of cyan C2, magenta M2, and yellow Y2> 1 part of polyethylene wax c [Mn: 1,500, melting point: 103 ° C, density: 0.93]

The cyan C2, magenta M2, and yellow Y are operated in the same manner as the corresponding colors of the toners C1, M1, and Y1 except that the polyethylene b of cyan C1, magenta M1, and yellow Y1 of Example 1 is changed to the above-described polyethylene c.
2 was produced. The softening temperatures (Tc, Tm,
Ty) / Tg is 108 ° C./65° C. for C2 and 10% for M2.
7 ° C / 65 ° C, Y2 was 107 ° C / 65 ° C. As a result of evaluating the image characteristics with the full-color printer A using the three primary color toners C2, M2, Y2 and the black toner K1, all were excellent and good.

Example 3 <Preparation of Black Toner K2> A black toner K1 was prepared in the same manner as in Example 1 except that the number of added polyethylene a of the black toner K1 was changed from 0.5 part to 1 part. K2 was produced. The softening temperature (Tb) of this toner was 141 ° C. and Tg was 65 ° C. The black toner K2 and the three primary color toners C1. As a result of evaluating the image characteristics with the full-color printer A using M1 and Y1, all were good.

Example 4 <Production of Cyan C3, Magenta M3, and Yellow Y3> Except that the number of added polyethylene b of cyan C1, magenta M1, and yellow Y1 in Example 1 was changed from 1 part to 0.5 part. Produced cyan C3, magenta M3, and yellow Y3 in the same operation as the corresponding colors of the toners C1, M1, and Y1. Softening temperature (Tc, Tm, Ty) of these toners
/ Tg is 108 ° C / 65 ° C for C3 and 107 ° C /
65 ° C, Y3 was 107 ° C / 65 ° C. Using the three primary color toners C3, M3, and Y3 and the black toner K1 of Example 1, the image characteristics were evaluated by a full-color printer A. As a result, all were excellent and good.

Example 5 <Preparation of Black Toner K3> The black toner K1 of Example 1 was changed in the same manner as the toner K1 except that the number of added polyethylene a was changed from 0.5 part to 3 parts. K3 was prepared. The softening temperature (Tb) of this toner was 141 ° C. and Tg was 65 ° C. Using the black toner K3 and the three primary color toners C1, M1, and Y1 of Example 1, the results of evaluating the image characteristics with the full-color printer A are shown in Table 1. The image density is slightly higher, and the toner consumption is slightly larger. However, overall, it was almost good.

[0080]

Example 6 <Preparation of Black Toner K4> • 1 part of polyethylene wax a [Mn: 6,000, melting point: 133 ° C., density 0.96 kg / m ³ ] • Polypropylene wax (oxidized type) d 2 parts [Mn: 3,000, melting point: 145 ° C, density: 0.89 kg / m ³ , acid value: 3.5 KOHmg / g]

A black toner K4 was produced in the same manner as in the toner K1 except that the polyethylene a of the black toner K1 in Example 1 was changed to the polyethylene wax a and the polypropylene wax d. The softening temperature (Tb) of this toner was 142 ° C. and Tg was 65 ° C. The black toner K4 and the three primary color toners C1 and M of the first embodiment are used.
1. As a result of evaluating the image characteristics with the full-color printer A using Y1, all were good.

Comparative Example 1 <Preparation of Black Toner K5> A black toner K5 was prepared in the same manner as the toner K1 except that the polyethylene a of the black toner K1 of Example 1 was not used (the number of added parts was 0). The softening temperature (Tb) of this toner is 141 ° C.
g was 64 ° C. As a result of evaluating the image characteristics with the full-color printer A using the black toner K5 and the three primary color toners C1, M1, and Y1 of Example 1, the fogging on the photoreceptor is poor, and the toner consumption during continuous actual shooting is large. Was not preferred.

Comparative Example 2 <Preparation of Black Toner K6> The black toner K1 of Example 1 was changed in the same manner as the toner K1 except that the addition amount of polyethylene a was changed from 0.5 part to 5 parts. K6 was produced. The softening temperature (Tb) of this toner is 1
42 ° C. and Tg was 65 ° C. This black toner K
As a result of evaluating the image characteristics with the full-color printer A using the three primary color toners C1, M1, and Y1 of Example 6 and Example 1, the fog on the photoreceptor was poor, and the toner consumption during continuous actual shooting was extremely large. It was not preferable as image characteristics such as occurrence of unevenness in the image.

Comparative Example 3 <Preparation of Black Toner K7> 100 parts of linear polyester resin B1 The same operation as in Example 1 was performed except that the nonlinear polyester resin A1 of Example 1 was changed to the above-mentioned linear polyester resin B1. A black toner K7 was produced. The softening temperature (Tb) of this toner was 108 ° C. and Tg was 65 ° C. This black toner K7 and the three primary color toners C1 of the first embodiment,
As a result of evaluating the image characteristics with the full-color printer A using M1 and Y1, the fogging on the photoreceptor is poor, the toner consumption during continuous actual shooting is large, and the glossiness of the black image is too high, and the image density is too high. Was also unfavorable as an image characteristic that was too high.

[0085]

[Table 7]

[0086]

[Table 8]

[Evaluation Method] The test method for each evaluation item is as follows.
As shown. 1. Image density Print on plain paper with the specified full-color printer.
Image part (1 cm square for each color) manufactured by Nippon Lithographic Equipment Co., Ltd.
X-Rite 938 spectrocolorimeter (light source: C light source, visual
Field angle 2 ゜, Response: Measure reflection density at A)
The image density was used. 2. White background fog Printed on plain paper with the specified full-color printer
The non-image area, white background, is spectrally measured by Nihon Planographic Equipment Co., Ltd.
Densitometer X-Rite 938 (light source: C light source, viewing angle 2)
゜, response: A) and L^*a^*b^*Measure the pudding
White background L before and after ^*a^*b^*From the following equation, the color difference (△ E
₁ ) And a fog on a white background.

[0088]

## EQU3 ## Color difference (△ E ₁ ) = [(L ^* _i− L ^* _p ) ² +
^{_{(A * i -a * p)}} 2 + (b * i -b * p) 2] 1/2 L * i, a * i, b * i: white background value before printing L ^* _p, a ^* _p , B ^* _p : white background value after printing

3. Fog on photoreceptor Print on plain paper with toner from a specified full-color printer, print in blank paper mode, forcibly stop during printing, and apply fog on the photoreceptor (from the transfer section after the development section on the photoconductor). The toner (front toner) is collected with a 3M company mending tape, and after collection, is attached to plain paper (white paper). L ^* a ^* b ^* of the fogged portion of the attached tape was measured with a spectral colorimeter X-Rite 938 (light source: C light source, viewing angle 2 °, response: A) manufactured by Nihon Planographic Equipment Co., Ltd.
From L ^* a ^* b ^* before and after fog collection, the color difference (△
E ₂ ) was determined and a white background fog was determined.

[0090]

## EQU4 ## Color difference (△ E ₂ ) = [(L ^* _j− L ^* _q ) ² +
^{_{(A * j -a * q)}} 2 + (b * j -b * q) 2] 1/2 L * j, a * j, b * j: tape value of the previous head collecting L ^* _q, a ^* _q , B ^* _q : tape value after fogging

4. Gloss The solid image was printed on plain paper with a predetermined full-color printer, and the gloss value measured with a gloss meter VG-2000 (angle 75 °) manufactured by Nippon Denshoku Industries Co., Ltd. was defined as the gloss.

[0092]

According to the present invention, in a full-color image forming method used in an electrophotographic recording apparatus or the like, toner charging characteristics are good, image characteristics such as image density and fog are good, and durability characteristics are obtained even when continuous printing is performed. It is stable and good, has good fixability in heat fixing, and has excellent effects.

[Brief description of the drawings]

FIG. 1 is a schematic view of a main configuration of an electrophotographic recording apparatus using a non-magnetic one-component toner which is an example of a full-color image forming method of the present invention.

FIG. 2 is a schematic diagram showing a main configuration of an electrophotographic recording apparatus used in a full-color tandem system which is an example of a full-color image forming method of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photoconductor 2 charging device 3 exposure device 4 developing device 5 transfer device 6 cleaning device 7 fixing device 4k black developing device 4y yellow developing device 4c cyan developing device 4m magenta developing device 41 replenishing device 42 agitator 43 supply roller 44 developing roller 45 regulation Member 71 Upper fixing member 72 Lower fixing member 73 Heating device T Toner P Recording paper

Continued on the front page (72) Inventor Takeshi Owada 1 Fukudacho, Joetsu City, Niigata Prefecture Inside the Naoetsu Office, Mitsubishi Chemical Corporation (72) Inventor Teruki Senoguchi 1 Fukudacho, Joetsu City, Niigata Mitsubishi Naoetsu Business, Ltd. In-house (72) Inventor Masakazu Sugihara 1 Fukudacho, Joetsu-shi, Niigata F-term in Naoetsu Plant, Mitsubishi Chemical Corporation 2H005 AA01 AA02 AA06 AA21 CA03 CA08 CA13 CA17 CA22 CA25 CB18 DA02 DA04 DA06 EA03 EA06 EA07 FA06 FA07 FA07

Claims (26)

[Claims] 1. A full-color image forming method for forming a color image using a plurality of color toners and a black toner, wherein the plurality of color toners and the black toner include at least a binder resin, a polyolefin wax, a colorant, and charge control. The softening temperature of each of the plurality of color toners is lower than the softening temperature of the black toner, and the addition amount of the polyolefin wax in the plurality of color toners is all polyolefin wax in the black toner. A full-color image forming method, characterized in that the amount is not less than the amount added. 2. A full-color image forming method for forming a color image using three primary color toners of cyan, magenta and yellow and a black toner, wherein the three primary color toners and the black toner include at least a binder resin, a polyolefin wax,
It contains a colorant and a charge control agent, and all of the softening temperature (Tc) of the cyan toner, the softening temperature (Tm) of the magenta toner, and the softening temperature (Ty) of the yellow toner are equal to the softening temperature (Tb) of the black toner. ), The amount of polyolefin wax in the cyan toner (Wc), the amount of polyolefin wax in the magenta toner (Wc)
m) and the addition amount (Wy) of the polyolefin wax in the yellow toner is not less than the addition amount (Wb) of the polyolefin wax in the black toner. 3. The polyolefin wax content of the black toner is as follows: the addition amount (Wc) of the polyolefin wax in the cyan toner, the addition amount (Wm) of the polyolefin wax in the magenta toner, and the addition amount (Wy) of the polyolefin wax in the yellow toner. 3. The full-color image forming method according to claim 1, wherein the amount (Wb) of the full-color image is larger than the total amount (Wb). 4. A full-color image forming method according to claim 1, wherein said polyolefin wax is a wax of polypropylene, polyethylene, or an ethylene-propylene copolymer. 5. The amount of the polyolefin wax in each of the three primary color toners and the black toner is less than 10%.
5. The full-color image forming method according to claim 2, wherein the amount is 0.1 to 6 parts by weight with respect to 0 parts by weight. 6. The polyolefin wax in each of the three primary color toners and the black toner has a molecular weight of 1000-1.
6. The full-color image forming method according to claim 2, wherein the number is 0000. 7. The full-color image forming method according to claim 2, wherein the binder resin of the three primary color toners and the black toner is a styrene resin or a polyester resin, respectively. 8. The full-color image forming method according to claim 2, wherein the binder resin of the three primary color toners and the binder resin of the black toner are linear or non-linear polyester resins, respectively. 9. The toner according to claim 2, wherein the binder resin for the three primary color toners is a linear or non-linear polyester resin, and the binder resin for the black toner is a non-linear polyester resin. Full-color image forming method. 10. The softening temperature of the three primary color toners (Tc,
10. The full-color image forming method according to claim 2, wherein Tm and Ty) are 80 to 160 ° C., respectively, and the softening temperature (Tb) of the black toner is 80 to 160 ° C. 11. The softening temperature of the three primary color toners (Tc,
Tm, Ty) and the softening temperature (Tb) of the black toner are each 3 ° C. or more.
0. The method for forming a full-color image according to 0. 12. The colorant of the cyan toner contains at least C.I. I. Pigment Blue 15: 3 or 1
12. The full-color image forming method according to claim 2, comprising any one of 5: 4 blue pigments. 13. The colorant of the magenta toner, wherein at least a colorant of C.I. I. Pigment Red 57: 1, 12
2, 146, 184, 238, or pigment
The full-color image forming method according to any one of claims 2 to 11, wherein the method includes one of a red pigment and a red pigment of violet 19. 14. The colorant of the yellow toner, at least C.I. I. Pigment Yellow 13, 17
The full-color image forming method according to any one of claims 2 to 11, further comprising any one of the yellow pigments of (74), (93), (150), (155), (180) and (185). 15. The full-color image forming method according to claim 1, wherein the colorant of the black toner contains at least carbon black or magnetite. 16. The full-color image forming method according to claim 1, wherein the charge control agent is a negatively chargeable charge control agent. 17. The charge control agent for the three primary color toners of cyan, magenta and yellow is at least a charge control agent of the following general formula [I], and the charge control agent for the black toner is an azo metal compound. 17. The full-color image forming method according to claim 1, wherein: Embedded image (In the formula, R ₁ and R ₄ represent a hydrogen atom, an alkyl group, a substituted or unsubstituted aromatic ring (including a condensed ring), and X ⁺ represents a cation.) 18. The charge control agent for the three primary color toners, wherein in formula [I], R _{1 to} R ₄ are phenyl groups;
18. The full-color image forming method according to claim 1, wherein ⁺ is a potassium ion, and the metal component in the azo metal compound of the black toner is chromium or iron. 19. The full-color image forming method according to claim 17, wherein the azo metal compound charge control agent of the black toner is a compound represented by the following general formula [II]. Embedded image (Where A to D may be the same or different,
Represents an optionally substituted benzene ring. X ⁺ represents a cation. ) 20. The full-color image forming method according to claim 17, wherein the azo metal compound charge control agent of the black toner is a compound represented by the following general formula [III]. Embedded image (In the formula, E to J may be the same or different, and represent a benzene ring which may be substituted. X ⁺ represents a cation.) 21. The method according to claim 2, wherein the three primary color toners and the black toner are fixed by a heating contact method.
21. The full-color image forming method according to any one of Items 20 to 20. 22. When the three primary color toners and the black toner are 1
22. The full-color image forming method according to claim 2, wherein the image is developed by a component developing system. 23. The full-color image forming method according to claim 22, wherein the one-component developing method for the three primary color toners is a non-magnetic one-component developing method comprising at least a developing roll and a toner layer regulating member. . 24. The method according to claim 2, wherein the full-color image forming method is used in a tandem system.
3. The method for forming a full-color image according to item 1. 25. In the tandem method, cyan,
25. The image forming method according to claim 24, wherein the developing units for the three primary colors of magenta and yellow are located in front, and the developing unit for the black toner is located behind the color developing unit. 26. The full-color image forming method according to claim 1, wherein the colorant of the black toner contains acidic carbon black.