JP4867702B2 - Electrophotographic toner, electrophotographic developer, toner cartridge, process cartridge, and image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic toner, an electrophotographic developer, a toner cartridge, a process cartridge, and an image forming apparatus.

  Many methods are already known as electrophotographic methods. In general, an electrostatic latent image is electrically formed by various means on the surface of a photoconductor (latent image holding body) using a photoconductive substance, and the formed latent image is transferred to an electrophotographic toner ( In the following, the toner image on the surface of the latent image holding member is transferred to or from a transfer medium such as paper with or without an intermediate transfer member. A fixed image is formed through a plurality of steps of transferring to the surface of the body (recording medium) and fixing the transferred toner image by heating, pressing, heating and pressing, or solvent vapor. The toner remaining on the surface of the latent image holding member is removed (cleaned) by various methods as necessary, and is subjected again to the above-described plurality of steps.

  As a fixing technique for fixing the transferred toner image transferred to the surface of the transfer target, a hot roll fixing in which the transfer target with the toner image transferred is inserted and fixed between a pair of rolls consisting of a heating roll and a pressure roll. The law is common. In addition, as the same type of technology, one in which one or both of the rolls are replaced with a belt is also known.

  On the other hand, in order to reduce the amount of energy used in the image forming apparatus, a technique for fixing toner with lower energy is desired. Therefore, there is a strong demand for an electrophotographic toner that can be fixed at a lower temperature. As a method of fixing at a lower temperature, a technique using a crystalline resin is known, and from the viewpoint of further imparting toner strength, it has been tried to use a mixture of an amorphous resin together with a crystalline resin. (For example, refer to Patent Document 1).

In recent years, from the viewpoint of high image quality, the susceptibility of the surface of an image to one is important as one of the important qualities. A toner composed of a mixture of a crystalline resin and an amorphous resin and having good scratch resistance, (1) containing a specific percentage of a crystalline compound having a specific chemical structure, and containing the compound For this reason, a toner having a thermal behavior peculiar to melting and crystallization of crystals is known (see, for example, Patent Document 2). Further, (2) a toner having a specific exothermic peak near the glass transition point (Tg) of the binder resin is known (see, for example, Patent Document 3). However, in order to meet the increasing demand for higher image quality, further improvement in scratch resistance has been desired.
JP 2004-191623 A JP 2001-318484 A JP 2004-184561 A

  The present invention has been made in view of the above circumstances, and provides an electrophotographic toner and an electrophotographic developer capable of obtaining an image excellent in scratch resistance, a toner cartridge and a process cartridge using the electrophotographic developer, and scratch resistance. An object of the present invention is to provide an image forming apparatus capable of obtaining an image having excellent properties.

The above-mentioned subject is achieved by the following present invention.
That is, the invention according to claim 1 synthesizes at least a colorant, a crystalline polyester in which the ester concentration M represented by the following formula 1 is 0.07 ≦ M ≦ 0.09, an alcohol component and an acid component. Among the alcohol components, an alkylene oxide adduct of bisphenol A is used in an amount of 50 mol% to 90 mol%, and among the alcohol components, a linear aliphatic diol having 8 to 20 carbon atoms is used in an amount of 10 mol% to 30 mol. And a non-crystalline polyester used in an amount of not more than mol%, and the content ratio (mass ratio) of the non-crystalline polyester and the crystalline polyester is 75:25 to 98: 2.
(Formula 1) Ester concentration (M) = K / A
(In Formula 1, K represents the number of ester groups in the polyester, and A represents the number of atoms constituting the polymer chain of the polyester.)

  The invention according to claim 2 is the electrophotographic toner wherein the amount of the alkylene oxide adduct of bisphenol A in the alcohol component according to claim 1 is 60 mol% or more and 85 mol% or less.

  The invention according to claim 3 is the electrophotographic toner in which the amount of the linear aliphatic diol in the alcohol component according to claim 1 or 2 is 15 mol% or more and 25 mol% or less.

  According to a fourth aspect of the present invention, the electrophotographic toner according to any one of the first to third aspects is produced by aggregating and combining the crystalline polyester particles, the amorphous polyester particles, and the colorant particles. Electrophotographic toner.

  The invention according to claim 5 is an electrophotographic developer containing the electrophotographic toner according to any one of claims 1 to 4.

  The invention according to claim 6 is detachable from an image forming apparatus having at least a developing unit that develops an electrostatic latent image to form a toner image, and is claimed as a developer to be supplied to the developing unit. Item 6. A toner cartridge containing the electrophotographic developer according to Item 5.

  The invention according to claim 7 is a process cartridge including at least a developer holding member and containing the electrophotographic developer according to claim 5.

  According to an eighth aspect of the present invention, there is provided a latent image holding member, latent image forming means for forming an electrostatic latent image on the surface of the latent image holding member, and developing the electrostatic latent image according to the fifth aspect. A developing unit that forms a toner image by developing with an agent; a transfer unit that transfers the toner image to the surface of the transfer target; and a fixing unit that fixes the toner image transferred to the surface of the transfer target. An image forming apparatus.

  According to the first aspect of the present invention, an image having excellent scratch resistance can be obtained as compared with the case where the present configuration is not provided.

  According to the second aspect of the present invention, an image excellent in scratch resistance can be obtained more suitably than in the case where the present configuration is not provided.

  According to the invention of claim 3, it is possible to more suitably obtain an image having excellent scratch resistance as compared with the case where the present configuration is not provided, and it is possible to easily control the glass transition point of the resin by a preferable region. it can.

  According to the fourth aspect of the present invention, it is possible to provide a toner for electrophotography having a uniform particle diameter as compared with the case where this configuration is not provided, and an image with higher image quality can be obtained.

  According to the invention which concerns on Claim 5, compared with the case where it does not have this structure, the image excellent in scratch resistance can be obtained.

  According to the sixth aspect of the present invention, it is possible to facilitate the supply of an electrophotographic toner capable of obtaining an image excellent in scratch resistance and to improve the maintainability of the above characteristics as compared with the case where the present configuration is not provided. .

  According to the seventh aspect of the present invention, it is possible to easily handle an electrophotographic developer capable of obtaining an image excellent in scratch resistance as compared with the case where the present configuration is not provided, and to provide an image forming apparatus having various configurations. Adaptability can be increased.

  According to the eighth aspect of the present invention, an image having excellent scratch resistance can be obtained as compared with the case where this configuration is not provided.

  The toner for electrophotography of the present invention contains at least a crystalline polyester and an amorphous polyester as a binder resin, and a colorant, and the ester concentration M of the crystalline polyester represented by the following formula 1 is 0.00. 07 ≦ M ≦ 0.09, the amorphous polyester is obtained by synthesizing an alcohol component and an acid component, and an alkylene oxide adduct of bisphenol A is used in an amount of 50 mol% to 90 mol% of the alcohol component, Further, among the alcohol components, a linear aliphatic diol having 8 to 20 carbon atoms is used in an amount of 10 mol% to 30 mol%, and the content ratio (mass ratio) of the amorphous polyester to the crystalline polyester is 75: 25-98: 2.

(Formula 1) Ester concentration (M) = K / A
(In Formula 1, K represents the number of ester groups in the polyester, and A represents the number of atoms constituting the polymer chain of the polyester.)

  Although the manifestation of the effect is not clearly understood, a specific crystalline polyester in which the ester concentration M is 0.07 ≦ M ≦ 0.09, and a linear aliphatic diol having 8 to 20 carbon atoms And a specific amorphous polyester containing 10 mol% or more and 30 mol% or less of the alcohol component, the long chain alkyl groups of both are entangled and appropriately mixed, and even in an image after fixing. Separation does not proceed, and by using a specific non-crystalline polyester containing an alkylene oxide adduct of bisphenol A in an amount of 50 mol% to 90 mol% of the alcohol component, the strength of the resin can be improved due to excellent rigidity. It is presumed that excellent scratch resistance can be obtained by these actions.

  Hereinafter, in describing the present invention in detail, the composition of an electrophotographic toner will be described first.

<Crystalline polyester>
It is an essential requirement that the electrophotographic toner of the present invention contains a crystalline polyester.
Here, in the present invention, “crystallinity” of “crystalline polyester” refers to having a clear endothermic peak in the differential scanning calorimetry (DSC), not a stepwise endothermic change. Further, the endothermic peak may show a peak having a width of 40 to 50 ° C. when the toner is used.

The crystalline polyester used in the present invention requires that the ester concentration M represented by the following formula 1 is 0.07 ≦ M ≦ 0.09.
(Formula 1) Ester concentration (M) = K / A
(In Formula 1, K represents the number of ester groups in the resin, and A represents the number of atoms constituting the polymer chain of the resin.)

  The “ester concentration M” is one index indicating the ester group content in the crystalline polyester polymer compound. The “number of ester groups contained in the crystalline polyester” represented by K in Formula 1 above refers to the number of ester bonds contained in the entire crystalline polyester.

  The “number of atoms constituting the polymer chain of the polyester” represented by A in the formula 1 is the total number of atoms constituting the polymer chain of the crystalline polyester, and includes all the atoms involved in the ester bond. However, it does not include the number of atoms of branched parts in other constituent parts. That is, carbon atoms and oxygen atoms derived from carboxyl groups and alcohol groups involved in ester bonds (two oxygen atoms in one ester bond) and the six carbons constituting the polymer chain, for example, in the aromatic ring, Although included in the calculation of the number of atoms, for example, a hydrogen atom in an aromatic ring or an alkyl group, or an atom or atomic group of a substituent thereof constituting the polymer chain is not included in the calculation of the number of atoms.

  To explain with a specific example, among the total of 10 atoms of 6 carbon atoms and 4 hydrogen atoms in the arylene group constituting the polymer chain, the “number of atoms constituting the polymer chain of the polyester” Included are only six carbon atoms, and even if the hydrogen is substituted with any substituent, the atoms constituting the substituent are the number of atoms constituting the polymer chain of the polyester. Is not included.

When the crystalline polyester is one repeating unit (for example, when the polymer compound is represented by H— [OCOR ¹ COOR ² O—] _n —H, the one repeating unit is represented in []. ¹ and R ² represent a monovalent group, and n represents an integer of 1 or more.) In the case of a homopolymer consisting of only two ester bonds in one repeating unit (ie, Since the number of ester groups K ′ = 2) in the repeating unit, the ester concentration M can be obtained by the following formula 1-1.
(Formula 1-1) Ester concentration M = 2 / A ′
(In Formula 1-1, A ′ represents the number of atoms constituting the polymer chain in one repeating unit.)

In the case where the crystalline polyester according to the present invention is a copolymer composed of a plurality of copolymer units, the number of ester groups KX and the number of atoms AX constituting the polymer chain are obtained for each copolymer unit. After multiplying by the copolymerization ratio, it can be obtained by summing each of them and substituting them into the formula 1. For example, the compound [(Xa) _a (Xb) _b (Xc) _c] has three copolymerized units of Xa, Xb and Xc, and the copolymerization ratio thereof is a: b: c (where a + b + c = 1). ] Can be obtained by the following formula 1-2.
(Formula 1-2) Ester concentration M = {KXa × a + KXb × b + KXc × c} /
{AXa × a + AXb × b + AXc × c}
(In Formula 1-2, KXa represents copolymer unit Xa, KXb represents copolymer unit Xb, KXc represents the number of ester groups in copolymer unit Xc, AXa represents copolymer unit Xa, and AXb represents copolymer unit Xb, AXc. Represents the number of atoms constituting each polymer chain in the copolymer unit Xc.)
The ester concentration M described in this specification is a value obtained by the above calculation method.

  The ester concentration M from the electrophotographic toner, which is a finished product, is calculated by first removing toluene-soluble components from the toner, then separating the crystalline resin, and identifying the polymer structure by analysis such as NMR. The ester concentration can be calculated.

  In the case of a crystalline polyester (including a high molecular weight body and a low molecular weight body) used in the present invention, in the case of a resin obtained by copolymerizing other components with respect to the main chain of the crystalline polyester, the amount of other components is 50% by mass or less. If present, this copolymer is also called crystalline polyester.

  The crystalline polyester is a specific crystalline polyester synthesized from an acid (dicarboxylic acid) component and an alcohol (diol) component. Thereafter, in the polyester resin, the component part that was an acid component before the polyester synthesis was referred to as “acid-derived component”, and the component part that was an alcohol component before the polyester synthesis was referred to as an “alcohol-derived component”. Show.

-Acid-derived components-
Examples of the acid component (acid for forming an acid-derived constituent component) include various dicarboxylic acids, and examples of the main acid component used for the synthesis of a specific crystalline polyester include aliphatic dicarboxylic acids and aromatic dicarboxylic acids. An acid is desirable, and a linear carboxylic acid is particularly desirable for the aliphatic dicarboxylic acid.

  Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelic acid, sebacic acid, 1,9-nonanedicarboxylic acid, and 1,10-decanedicarboxylic acid. 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, etc. Or lower alkyl esters and acid anhydrides thereof, but are not limited thereto. Of these, sebacic acid and 1,10-decanedicarboxylic acid are preferred. A dicarboxylic acid having a double bond can be used suitably because the entire resin can be crosslinked using the double bond. Examples of the dicarboxylic acid include, but are not limited to, fumaric acid, maleic acid, 3-hexenedioic acid, and 3-octenedioic acid. Moreover, these lower alkyl esters, acid anhydrides, etc. are also mentioned. Of these, fumaric acid and maleic acid are preferred.

  Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, t-butylisophthalic acid, 2,6-naphthalenedicarboxylic acid, and 4,4′-biphenyldicarboxylic acid, but are not limited thereto. . Among these, terephthalic acid, isophthalic acid, t-butylisophthalic acid, and alkyl esters thereof are preferable. The amount of aromatic dicarboxylic acid polymerized is preferably 10 constituent mol%.

  Here, in the present specification, “constituent mol%” means that the acid-derived constituent component in the entire acid-derived constituent component in the polyester or the alcohol constituent component in the entire alcohol-derived constituent component is 1 unit (mol). ) Indicates the percentage.

-Alcohol-derived components-
As the alcohol component (alcohol for becoming an alcohol-derived constituent component), an aliphatic diol is preferable, and a linear aliphatic diol having a chain carbon number of 7 to 20 is more preferable.

  Further, when a polyester is obtained by condensation polymerization with an aromatic dicarboxylic acid, the chain carbon number is preferably an odd number.

  Specific examples of the aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,7-heptanediol. 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol 1,18-octadecanediol, 1,20-eicosanediol and the like, but are not limited thereto. Of these, ethylene glycol, 1,4-butanediol, 1,6-henquinsandiol, 1,9-nonanediol, and 1,10-decanediol are preferable.

  The alcohol-derived constituent component preferably has an aliphatic diol-derived constituent component content of 80 constituent mol% or more, and includes other components as necessary. As the alcohol-derived constituent component, the content of the aliphatic diol-derived constituent component is more preferably 90 constituent mol% or more.

  The components (monomers) that can be used are listed above, but they are monomers available for industrial use, and the ester concentration M of the crystalline polyester is controlled to 0.07 ≦ M ≦ 0.09. Therefore, at least one selected from sebacic acid, dodecanedioic acid and tetradecanedioic acid is used as the dicarboxylic acid component, and 1,6-hexanediol, 1,9-nonanediol, 1,10- It is preferable to use at least one selected from decanediol and 1,12-dodecanediol as the main component (10 constituent mol% or more) in each of the acid component and the alcohol component.

-Method for producing crystalline polyester-
There is no restriction | limiting in particular as a manufacturing method of crystalline polyester, It can manufacture with the general polyester polymerization method which makes an acid component and an alcohol component react. For example, direct polycondensation, transesterification method, and the like can be used depending on the type of monomer. The molar ratio (acid component / alcohol component) for reacting the acid component with the alcohol component varies depending on the reaction conditions and the like and cannot be generally stated, but is usually about 1/1.

  Thus, as melting | fusing point of crystalline polyester obtained, it is preferable that it is the range of 60-120 degreeC, and it is more preferable that it is the range of 70-100 degreeC. In the present invention, the melting point of the crystalline polyester is measured using a differential scanning calorimeter (DSC), and the endothermic peak when the temperature is raised to 150 ° C. at a rate of temperature increase of 10 ° C. per minute. The top value of was used.

  Moreover, as a weight average molecular weight (Mw) measured by GPC of crystalline polyester, 10000-35000 are preferable, Furthermore, 15000-30000 are more preferable.

The weight average molecular weight was measured by the following method.
“HLC-8120GPC, SC-8020 (manufactured by Tosoh Corporation)” apparatus was used as gel permeation chromatography (GPC), and the column was “TSKgel, SuperHM-H (manufactured by Tosoh Corporation), 6.0 mm ID × 15 cm) ”, and THF (tetrahydrofuran) was used as an eluent. As experimental conditions, an experiment was performed using a sample concentration of 0.5%, a flow rate of 0.6 ml / min, a sample injection amount of 10 μl, a measurement temperature of 40 ° C., and an IR detector. The calibration curve is “polystylen standard sample TSK standard” manufactured by Tosoh Corporation: “A-500”, “F-1”, “F-10”, “F-80”, “F-380”, “A-2500”. ”,“ F-4 ”,“ F-40 ”,“ F-128 ”, and“ F-700 ”.

<Amorphous polyester>
It is an essential requirement that the electrophotographic toner of the present invention contains an amorphous polyester. The amorphous polyester is obtained by synthesizing an alcohol component and an acid component. Among the alcohol components, an alkylene oxide adduct of bisphenol A is used in an amount of 50 mol% to 90 mol%, and the alcohol component has 8 to 20 carbon atoms. It is necessary to use 10 to 30 mol% of the following linear aliphatic diol.

The alkylene oxide adduct of bisphenol A is particularly preferably used in an amount of 60 mol% to 85 mol% of the alcohol component.
The linear aliphatic diol is particularly preferably used in an amount of 15 mol% to 25 mol%.

Amount of the above-mentioned alkylene oxide adduct of bisphenol A and linear aliphatic diol having 8 to 20 carbon atoms (among alcohol components used for the synthesis of the amorphous polyester, the alkylene oxide adduct of bisphenol A and 8 or more carbon atoms) The amount of each of the 20 or less linear aliphatic diols) can be calculated from the composition of the amorphous polyester, and the amounts described in the present specification are values determined by the method.
In the case of measuring these amounts from the electrophotographic toner as a finished product, first, the toluene-soluble component of the toner is extracted, and after toluene is distilled off, the structure of the resin is analyzed by NMR or the like, It can be calculated by measuring the monomer composition.

-Alcohol-derived components-
Examples of the alkylene oxide adduct of bisphenol A include ethylene oxide of bisphenol A and propylene oxide of bisphenol A. Alkylene oxides such as ethylene oxide and propylene oxide include 2 mole adducts, 3 moles, and 4 mole adducts, but are not particularly limited. These monomers may be used in combination of two or more, and the mixing amount can be adjusted.

  Examples of the linear aliphatic diol having 8 to 20 carbon atoms include 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, and 1,20-eicosanediol. Etc. These diol components may be used in combination of two or more.

In addition, other monomers can be used as the alcohol component. For example, monomer components described in “Polymer Data Handbook: Basic Edition” (Edition of Polymer Society: Bafukan), and conventionally known divalent or trivalent or higher alcohols can be mentioned.
Examples of the divalent alcohol include 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 1, Examples include 5-pentanediol and neopentyl glycol. Examples of the trivalent or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like. These may be used individually by 1 type and may use 2 or more types together.

-Acid-derived components-
Examples of the acid component used in the non-crystalline polyester include monomer components described in “Polymer Data Handbook: Basic Edition” (Edition of Polymer Society: Bafukan). These carboxylic acids are mentioned.
Examples of the divalent carboxylic acid include succinic acid, glutaric acid, adipic acid, peric acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2, Dibasic acids such as 7-dicarboxylic acid, cyclohexanedicarboxylic acid, malonic acid, mesaconic acid, dodecenyl succinic acid, etc., and their anhydrides and their lower alkyl esters, maleic acid, fumaric acid, itaconic acid, citraconic acid and other fats Group unsaturated dicarboxylic acid. Examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and the like, and anhydrides thereof. And lower alkyl esters. These may be used individually by 1 type and may use 2 or more types together. Among these, isophthalic acid and terephthalic acid are preferably used.

  In addition to the above-mentioned divalent or trivalent or higher carboxylic acid and divalent or trivalent or higher alcohol, monovalent acids such as acetic acid and benzoic acid, and monovalent alcohols such as cyclohexanol and benzyl alcohol are also available. Can be used.

  The non-crystalline polyester is combined with the monomer components described above, for example, polycondensation (chemical doujin), polymer experimental studies (polycondensation and polyaddition: Kyoritsu Publishing) and polyester handbook (Nikkan Kogyo Shimbun) Etc.) can be synthesized by using a conventionally known method as described in ed.), And a transesterification method, a direct polycondensation method or the like can be used alone or in combination.

  The weight average molecular weight Mw measured by GPC of the amorphous polyester used in the present invention is preferably in the range of 8,000 to 50,000, and the number average molecular weight Mn is in the range of 3,000 to 15,000. Those are preferred. In addition, as a gel permeation chromatography (GPC), the method used for the above-mentioned crystalline polyester is applicable.

  The content ratio (mass ratio) of the amorphous polyester and the crystalline polyester in the electrophotographic toner of the present invention is required to be 75:25 to 98: 2, and 85:15 to 96: 4. It is more preferable that

  In the electrophotographic toner of the present invention, the content of the crystalline polyester and the amorphous polyester is preferably 75% by mass or more and 95% by mass or less, and more preferably 80% by mass or more and 90% by mass. The following is more preferable.

<Colorant>
The colorant used in the electrophotographic toner of the present invention is not particularly limited and may be a known colorant, which can be selected according to the purpose. One type of colorant may be used alone, or two or more types of colorants of the same system may be mixed and used. Further, two or more kinds of different colorants may be mixed and used. Further, these colorants may be used after surface treatment.

  As the colorant to be used, pigments and dyes of various colors are used, and specific examples include those shown below. Examples of the black pigment include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, nonmagnetic ferrite, and magnetite. Examples of yellow pigments include yellow lead, zinc yellow, yellow iron oxide, cadmium yellow, chrome yellow, Hansa yellow, Hansa yellow 10G, benzidine yellow G, benzidine yellow GR, selenium yellow, quinoline yellow, permanent yellow NCG, and the like. it can.

  Examples of the orange pigment include red mouth yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, Vulcan orange, benzidine orange G, indanthrene brilliant orange RK, indanthrene brilliant orange GK and the like. Red pigments include Bengala, cadmium red, red lead, mercury sulfide, watching red, permanent red 4R, risor red, brilliant carmine 3B, brilliant carmine 6B, pyrazolone red, rhodamine lake B, lake red C, rose bengal, eosin red And alizarin lake.

Examples of blue pigments include bitumen, cobalt blue, alkali blue lake, Victoria blue lake, fast sky blue, indanthrene blue BC, ultramarine blue, phthalocyanine blue, and phthalocyanine green. Examples of purple pigments include manganese purple, fast violet B, and methyl violet lake.
Examples of the green pigment include chromium oxide, chromium green, pigment green B, malachite green lake, and final yellow green G.
Examples of white pigments include zinc white, titanium oxide, antimony white, and zinc sulfide. Examples of extender pigments include barite powder, barium carbonate, clay, silica, white carbon, talc, and alumina white.
Examples of the dye include various dyes such as basic, acidic, dispersed, and direct dyes, such as nigrosine, methylene blue, rose bengal, and quinoline yellow.

  With respect to these colorants, for example, a dispersion of colorant particles can be prepared using a media type dispersing machine such as a rotary shearing homogenizer, a ball mill, a sand mill, or an attritor, or a high-pressure opposed collision type dispersing machine. Further, these colorants can be dispersed in an aqueous system by a homogenizer using a polar surfactant.

  The colorant used in the toner of the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, light resistance, OHP permeability, and dispersibility in the toner. The colorant is preferably added in the range of 4% by mass to 15% by mass with respect to the total solid content of the toner in order to ensure the color developability at the time of fixing. It is more preferable to add in the range. However, when a magnetic material is used as the black colorant, it is preferably added in the range of 12% by mass to 48% by mass, and more preferably in the range of 15% by mass to 40% by mass.

  Further, the central diameter (median diameter) of the colorant particles contained in the toner is preferably in the range of 100 nm to 330 nm, and more preferably in the range of 100 nm to 200 nm. The center diameter of the colorant particles is measured with a laser diffraction particle size distribution analyzer (LA-700, manufactured by Horiba, Ltd.).

  By selecting the type of the colorant, each color toner such as yellow toner, magenta toner, cyan toner and black toner can be obtained.

<Release agent>
The toner of the present invention preferably contains a release agent.
A mold release agent is generally used for the purpose of improving mold release properties. Specific examples of the release agent include low molecular weight polyolefins such as polyethylene, polypropylene, and polybutene; silicones having a softening point by heating; fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide, and stearic acid amide Plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil; animal waxes such as beeswax; montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, etc. Mineral / petroleum waxes; ester waxes such as fatty acid esters, montanic acid esters, and carboxylic acid esters. In this invention, these mold release agents may be used individually by 1 type, and may use 2 or more types together.

  This is dispersed in water with polymer electrolytes such as ionic surfactants, polymer acids and polymer bases, heated above the melting point, and has a strong shearing ability and pressure discharge type disperser (Gorin homogenizer, A release agent dispersion can be obtained by dispersing the particles in a particle form having a diameter of 1 μm or less with a product of Gorin Co., Ltd. In addition, the particle diameter of the obtained releasing agent dispersion liquid can be measured, for example with a laser diffraction type particle size distribution measuring apparatus (LA-700, manufactured by Horiba, Ltd.).

  The addition amount of these release agents is preferably 0.5% by mass or more and 50% by mass or less, and more preferably 1% by mass or more and 30% by mass with respect to the total amount of the toner (toner particles) of the present invention. % Or less, more preferably 5% by mass or more and 15% by mass or less.

<Other ingredients>
Other components that can be used in the electrophotographic toner of the present invention are not particularly limited, and examples thereof include various known additives such as inorganic particles, organic particles, and charge control agents.

  The inorganic particles are generally used for the purpose of improving toner fluidity. Examples of the inorganic particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, cerium chloride. , Bengara, chromium oxide, cerium oxide, antimony trioxide, magnesium oxide, zirconium oxide, silicon carbide, silicon nitride and the like. Among these, silica particles are preferable, and silica particles that have been hydrophobized are particularly preferable.

  The average primary particle diameter (number average particle diameter) of the inorganic particles is preferably in the range of 1 nm to 1000 nm, and the addition amount (external addition) is 0.01 parts by mass or more with respect to 100 parts by mass of the toner. A range of 20 parts by mass or less is preferable.

  The organic particles are generally used for the purpose of improving cleaning property, transfer property, or charging property. Examples of the organic particles include particles such as polystyrene, polymethyl methacrylate, polyvinylidene fluoride, and polystyrene-acrylic copolymer.

  The charge control agent is generally used for the purpose of improving the chargeability. Examples of the charge control agent include salicylic acid metal salts, metal-containing azo compounds, nigrosine and quaternary ammonium salts.

<Core shell structure>
The surface of the electrophotographic toner of the present invention may be covered with a surface layer, that is, a shell portion (shell layer). It is desirable that the surface layer does not greatly affect the mechanical properties and melt viscoelastic properties of the entire toner. The surface has a resin coating layer, a particle coating layer, a chemical treatment coating layer, etc., and it is desirable that the surface layer has a small film thickness. It is preferable to be within the range. In the case of a particle coating layer, the particles are desirably 0.5 μm or less.

  In order to form a thin surface layer in the above range, a binder resin, its particles, a coloring agent, inorganic particles added as necessary, and particles containing other materials are adhered or adsorbed on the toner surface. The particles are smoothed and coated as necessary. In addition, a method of adsorbing a raw material monomer of resin and coating the resin while performing graft polymerization, interfacial polymerization, or chemical treatment is preferably used.

Examples of components constituting the surface layer include silane coupling agents, isocyanates, vinyl monomers, resins, and particles thereof.
As the silane coupling agent, a method in which the surface of the toner is coated with the coupling agent itself is preferable. The isocyanate is preferably a method in which diamine or dialcohol is contained in the resin and polymerized at the toner interface. In addition, surface layer formation such as isocyanate modification using a polyester terminal and urea formation of the interface in water can also be used.
As a method of chemically treating a vinyl monomer, for example, a strong oxidizing substance such as peroxide, a method of oxidizing by ozone oxidation, plasma oxidation, etc., graft polymerization of a polymerizable monomer containing a polar group, Examples include a method of bonding by seed polymerization.

In the present invention, the surface layer is preferably formed using an emulsion aggregation coalescence method. As the material for the surface layer, it is preferable to use an amorphous resin, which can be selected from the same material group as the amorphous polyester forming the core (the above-mentioned amorphous polyester). The material group and material composition may be the same as or different from the core part, but it is desirable that the crystalline resin be applied to the core part, so that it is different (that is, made of different monomers). Is preferred.
In addition, when material composition etc. differ, it is desirable for the difference of the SP value to be 0.5 or less. Further, it is preferable that the molecular weight and the glass transition point have the same physical properties.

  Here, the SP value of the resin is obtained by calculation using the Fedors parameter of the following (Equation 2). The SP value can be calculated from the composition ratio of the monomer used using the following formula.

SP value = √ (Ev / v) = √ (ΣΔei / ΣΔvi) (Formula 2)
(In Formula 2, Ev is the evaporation energy (cal / mol), v is the molar volume (cm ³ / mol), Δei is the evaporation energy of each atom or group, and Δvi is each atom or group. Represents the molar volume.)

  In the case where a surface layer is provided by chemically or physically adhering the above substance to the toner particle surface, for example, the resin particles can be coated on the outside of the toner base particles using the mechanical force together with the toner. . Examples of the resin particles include styrene resin, styrene-acrylic copolymer, and polyester. Examples of the mixer used for coating include a sample mill, a Henschel mill, a V blender, and a hybridizer.

  Further, particles such as metals, metal oxides, metal salts, ceramics, resins, resin particles, and carbon black may be further externally added.

<Toner production method>
Next, a method for producing the electrophotographic toner of the present invention will be described.
The method for producing the toner of the present invention is not particularly limited, but a wet production method for producing toner particles in water, such as an aggregation coalescence method, a suspension polymerization method, and a dissolution suspension method, is preferable. In particular, the aggregation coalescence method is preferable.

  The aggregation coalescence method is a resin particle dispersion in which resin particles (including the above-mentioned crystalline polyester particles and non-crystalline polyester particles) are dispersed, and a colorant particle dispersion in which colorant particles are dispersed (further separated. In the case of adding a mold agent, a mixing step of mixing a release agent particle dispersion liquid in which release agent particles are dispersed), the resin particles and the colorant particles (in the above case, further release agent particles) The agglomeration step of forming the agglomerated particle dispersion and a fusion / union step of fusing and uniting by heating to a temperature above the glass transition point of the resin particles.

  Specifically, a resin particle dispersion containing an ionic surfactant is generally prepared by an emulsion polymerization method or the like, and a colorant particle dispersion (further release agent particle dispersion in the above case) is mixed, Aggregated particles having a toner diameter are formed by causing heteroaggregation with an aggregating agent having a polarity opposite to that of the ionic surfactant, and then heated to a temperature equal to or higher than the glass transition point of the resin particles to form the aggregated particles. The toner is obtained by fusing, uniting, washing and drying.

  The resin particle dispersion in the mixing step is generally a crystalline resin dispersion (including the aforementioned crystalline polyester particles) and an amorphous resin dispersion (including the aforementioned amorphous polyester particles). ) And prepare each.

  In the initial stage of mixing the crystal and amorphous resin fine particle dispersion and the colorant particle dispersion (in the above case, the release agent particle dispersion) in the aggregation process, ions of each polarity The balance of the amount of the ionic dispersant is shifted, and a polymer of an inorganic metal salt such as polyaluminum chloride is added to neutralize the ion, and then the first-stage aggregated particles at a temperature below the glass transition point. After forming and stabilizing, as a second step, a resin particle dispersion treated with an ionic dispersant having a polarity and amount that compensates for the ionic balance deviation is added, and further, if necessary, in the aggregated particles. A second stage of agglomeration by heating slightly above the glass transition point of the resin particles and the resin contained in the added resin particles, slightly heated below the glass transition point and stabilized at a higher temperature. The particles added in Body may be one in which coalescence remain adhered to the surface of the agglomerated particles. Further, the stepwise operation of aggregation may be repeated a plurality of times. The additionally added resin particles may be made of a material different from the particles at the time of aggregation. By this two-stage method, a surface layer is formed to form a core-shell structure, and the inclusion of the crystalline resin and the colorant (in the above case, a release agent) is improved.

  In particular, when a vinyl monomer is used as the amorphous resin particles, a resin particle dispersion can be prepared by carrying out emulsion polymerization using an ionic surfactant or the like. In addition, in the case of other resins, if the resin is soluble in an oily solvent with relatively low solubility in water, the resin is dissolved in those solvents, and a homogenizer together with an ionic surfactant or polymer electrolyte in water. A resin particle dispersion liquid can be prepared by dispersing as a particle in water using a disperser or by phase-inversion emulsification and dispersing in water, and then evaporating the solvent by heating or decompressing.

  The crystalline resin can be dissolved and mixed in the resin particle dispersion, or can be mixed when preparing the release agent particle dispersion. This also makes it possible to blend the crystalline resin into the toner.

  The release agent is preferably dispersed, for example, as particles having a volume average particle size in the range of 150 nm to 1500 nm in the electrophotographic toner and contained in the range of 5% by mass to 25% by mass. As a more preferable range, the volume average particle size is 160 nm or more and 1400 nm or less, and the content is 7 mass% or more and 20 mass% or less.

  The release agent is dispersed in water together with ionic surfactants, polymer electrolytes such as polymer acids and polymer bases, and given strong shear using a homogenizer or pressure discharge type disperser while heating above the melting point. Thus, a dispersion of release agent particles of 1 μm or less can be prepared. The concentration of the surfactant used in the release agent dispersion is preferably 4% by mass or less with respect to the release agent.

  The colorant is preferably dispersed in the electrophotographic toner as particles having a volume average particle size in the range of 100 nm to 330 nm and contained in the range of 4% by mass to 15% by mass. As a more preferable range, the volume average particle size is 120 nm or more and 310 nm or less, and the content is 5 mass% or more and 14 mass% or less.

  The colorant is dispersed by a publicly known method. A high-pressure opposed collision type disperser or the like is preferably used.

  Examples of the surfactant used in the toner production method of the present invention for the purpose of emulsion polymerization of resin particles, dispersion of colorants, addition dispersion of resin particles, dispersion of release agents, aggregation thereof, or stabilization thereof Then, anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap, and cationic surfactants such as amine salt type and quaternary ammonium salt type can be used. . It is also effective to use a nonionic surfactant such as polyethylene glycol, alkylphenol ethylene oxide adduct, and polyhydric alcohol. As these dispersing means, general means such as a rotary shear type homogenizer, a ball mill having a medium, a sand mill, a dyno mill and the like can be used.

  When using colorant particles coated with polar resin particles, the resin and colorant are dissolved and dispersed in a solvent (water, surfactant, alcohol, etc.), and then the appropriate dispersant (including the active agent) is used. In addition, the coloring agent particles are fixed to the surface of the resin particles prepared by emulsion polymerization by dispersing in water and heating and decompressing to remove the solvent, or by mechanical shearing force or electric adsorption force. A method etc. can be adopted.

  In addition, after completion of the fusion / unification, a desired toner can be obtained through an arbitrary washing step, solid-liquid separation step, and drying step. In the washing step, it is preferable to perform substitution washing with ion-exchanged water. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, centrifugal filtration, decanter and the like are preferably used. Further, the drying process is not particularly limited, but aeration drying apparatus, spray drying apparatus, rotary drying apparatus, air flow drying apparatus, fluidized bed drying apparatus, heat transfer heating type drying apparatus, freeze drying apparatus and the like are preferably used.

  Furthermore, metal salts such as calcium carbonate, silica, alumina, titania, barium titanate, strontium titanate, calcium titanate, cerium oxide, zirconium oxide, magnesium oxide, and the like, which are generally used for toner production Inorganic particles such as compounds, ceramics, and carbon black, and resin particles such as vinyl resin, polyester, and silicone can be added to the toner surface by applying a shearing force in a dry state.

  These inorganic particles are preferably surface-treated with a coupling material or the like, and specifically as a coupling material, methyltrichlorosilane, methyldichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, Tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane , Decyltrimethoxysilane, hexamethylsilazane, N, N- (bistrimethylsilyl) acetamide, N, N-bis (trimethylsilyl) urea tert-butyldimethylchlorosilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypri Examples thereof include silane coupling agents such as pyrtrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane, and γ-chloropropyltrimethoxysilane, and titanium coupling agents.

  As a method for adding particles, after the toner is dried, the toner may be attached to the toner surface by a dry method using a mixer such as a V blender or a Henschel mixer, or the particles may be added to water or an aqueous liquid such as water / alcohol. After being dispersed, it may be added to the toner in a slurry state and dried to allow an external additive to adhere to the toner surface. Moreover, you may dry, spraying a slurry on dry powder.

<Electrophotographic developer>
Next, the electrophotographic developer of the present invention (hereinafter simply referred to as “developer”) will be described.
The developer of the present invention is not particularly limited except that it contains the toner of the present invention, and may have any component composition depending on the purpose. The developer of the present invention becomes a one-component developer when the toner is used alone, and becomes a two-component developer when the toner and carrier are used in combination.

  The carrier is not particularly limited, and examples thereof include known carriers. For example, known carriers such as resin-coated carriers described in JP-A-62-39879, JP-A-56-11461, etc. Is mentioned.

  Specific examples of the carrier include the following resin-coated carriers. Examples of the core particle of the carrier include ordinary iron powder, ferrite, and magnetite molding, and the volume average particle size is generally in the range of 30 μm to 200 μm.

  Examples of the coating resin for the resin-coated carrier include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, lauryl acrylate, 2-acrylic acid 2- Α-methylene fatty acid monocarboxylic acids such as ethylhexyl, methyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; nitrogen-containing acrylics such as dimethylaminoethyl methacrylate; vinyl such as acrylonitrile and methacrylonitrile Nitriles; Vinyl pyridines such as 2-vinyl pyridine and 4-vinyl pyridine; Vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; Vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl keto Homopolymers such as vinyl ketones such as ethylene; olefins such as ethylene and propylene; vinyl-based fluorine-containing monomers such as vinylidene fluoride, tetrafluoroethylene and hexafluoroethylene; Examples of the polymer include silicone resins including methylsilicone, methylphenylsilicone, etc., polyesters containing bisphenol, glycol and the like, epoxy resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, polycarbonate resins, and the like. These resins may be used alone or in combination of two or more. The coating amount of the coating resin is preferably in the range of 0.1 to 10 parts by mass and more preferably in the range of 0.5 to 3.0 parts by mass with respect to 100 parts by mass of the core particles. .

  For the production of the carrier, a heating kneader, a heating Henschel mixer, a UM mixer, or the like can be used. Depending on the amount of the coating resin, a heating fluidized rolling bed, a heating kiln, or the like can be used. .

  In the developer of the present invention, the mixing ratio of the toner and the carrier is not particularly limited and can be selected according to the purpose.

<Image forming apparatus>
Next, the image forming apparatus of the present invention using the electrophotographic developer of the present invention will be described.
The image forming apparatus of the present invention forms a toner image by developing a latent image holding member, latent image forming means for forming an electrostatic latent image on the surface of the latent image holding member, and developing the electrostatic latent image with a developer. A developing unit that transfers the toner image to the surface of the transfer target, and a fixing unit that fixes the toner image transferred to the surface of the transfer target. A photographic developer is used. In the case of an image forming apparatus using a plurality of types (multiple colors) of developer, it is necessary to use the electrophotographic developer of the present invention described above as at least one type (one color) of developer. Among them, it is preferable to use the above-described electrophotographic developer of the present invention as all kinds of developers.

  In this image forming apparatus, for example, the part including the developing unit may have a cartridge structure (process cartridge) that can be attached to and detached from the main body of the image forming apparatus. As the process cartridge, the process cartridge of the present invention that includes at least a developer holder and accommodates the electrophotographic developer of the present invention is preferably used.

Hereinafter, an example of the image forming apparatus of the present invention will be shown, but the present invention is not limited to this. The main part shown in the figure will be described, and the description of other parts will be omitted.
FIG. 1 is a schematic diagram showing a quadruple tandem full-color image forming apparatus. The image forming apparatus shown in FIG. 1 is a first to first electrophotographic method that outputs yellow (Y), magenta (M), cyan (C), and black (K) images based on color-separated image data. Fourth image forming units 10Y, 10M, 10C, and 10K (image forming means) are provided. These image forming units (hereinafter sometimes simply referred to as “units”) 10Y, 10M, 10C, and 10K are arranged in parallel at a predetermined distance from each other in the horizontal direction. The units 10Y, 10M, 10C, and 10K may be process cartridges that can be attached to and detached from the image forming apparatus main body.

Above each unit 10Y, 10M, 10C, 10K in the figure, an intermediate transfer belt 20 as an intermediate transfer member is extended through each unit. The intermediate transfer belt 20 is wound around a drive roller 22 and a support roller 24 that are in contact with the inner surface of the intermediate transfer belt 20, and travels in a direction from the first unit 10Y to the fourth unit 10K. The support roller 24 is biased in a direction away from the drive roller 22 by a spring or the like (not shown), and a predetermined tension is applied to the intermediate transfer belt 20 wound around both. An intermediate transfer member cleaning device 30 is provided on the side surface of the latent image holding member of the intermediate transfer belt 20 so as to face the drive roller 22.
Further, each of the developing devices (developing means) 4Y, 4M, 4C, and 4K of the units 10Y, 10M, 10C, and 10K includes yellow, magenta, cyan, and black contained in the toner cartridges 8Y, 8M, 8C, and 8K. The four color toners can be supplied.

  Since the first to fourth units 10Y, 10M, 10C, and 10K described above have the same configuration, here, the first unit that forms a yellow image disposed on the upstream side in the intermediate transfer belt traveling direction. 10Y will be described as a representative. Note that the second to fourth units are denoted by reference numerals with magenta (M), cyan (C), and black (K) instead of yellow (Y) in the same parts as the first unit 10Y. Description of 10M, 10C, 10K is omitted.

The first unit 10Y has a photoreceptor 1Y that functions as a latent image holding member. Around the photoreceptor 1Y, an electrostatic latent image is formed by exposing the surface of the photoreceptor 1Y to a predetermined potential by a charging roller 2Y and exposing the charged surface to a laser beam 3Y based on the color-separated image signal. An exposure device 3 for developing, a developing device (developing means) 4Y for developing the electrostatic latent image by supplying charged toner to the electrostatic latent image, and a primary transfer roller (for transferring the developed toner image onto the intermediate transfer belt 20). (Primary transfer unit) 5Y and a photoconductor cleaning device (cleaning unit) 6Y for removing toner remaining on the surface of the photoconductor 1Y after the primary transfer are sequentially arranged.
The primary transfer roller 5Y is disposed inside the intermediate transfer belt 20, and is provided at a position facing the photoreceptor 1Y. Further, a bias power source (not shown) for applying a primary transfer bias is connected to each of the primary transfer rollers 5Y, 5M, 5C, and 5K. Each bias power source varies the transfer bias applied to each primary transfer roller under the control of a control unit (not shown).

Hereinafter, an operation of forming a yellow image in the first unit 10Y will be described. First, prior to the operation, the surface of the photoreceptor 1Y is charged to a potential of about −600V to −800V by the charging roller 2Y.
The photoreceptor 1Y is formed by laminating a photosensitive layer on a conductive substrate (volume resistivity at 20 ° C .: 1 × 10 ⁻⁶ Ωcm or less). This photosensitive layer usually has a high resistance (a resistance equivalent to that of a general resin), but has a property that the specific resistance of the portion irradiated with the laser beam changes when irradiated with the laser beam 3Y. Therefore, a laser beam 3Y is output to the surface of the charged photoreceptor 1Y via the exposure device 3 in accordance with yellow image data sent from a control unit (not shown). The laser beam 3Y is applied to the photosensitive layer on the surface of the photoreceptor 1Y, whereby an electrostatic latent image of a yellow print pattern is formed on the surface of the photoreceptor 1Y.

The electrostatic latent image is an image formed on the surface of the photoreceptor 1Y by charging. The specific resistance of the irradiated portion of the photosensitive layer is lowered by the laser beam 3Y, and the charged charge on the surface of the photoreceptor 1Y flows. On the other hand, this is a so-called negative latent image formed by the charge remaining in the portion not irradiated with the laser beam 3Y.
The electrostatic latent image formed on the photoreceptor 1Y in this way is rotated to a predetermined development position as the photoreceptor 1Y travels. Then, at this development position, the electrostatic latent image on the photoreceptor 1Y is converted into a visible image (developed image) by the developing device 4Y.

  In the developing device 4Y, for example, yellow toner having a volume average particle diameter of 7 μm including at least a yellow colorant, crystalline polyester, and amorphous polyester is accommodated. The yellow toner is triboelectrically charged by being agitated inside the developing device 4Y, and has a charge of the same polarity (negative polarity) as the charged charge on the photoreceptor 1Y, and a developer roll (developer holder). Is held on. As the surface of the photoreceptor 1Y passes through the developing device 4Y, the yellow toner is electrostatically attached to the latent image portion on the surface of the photoreceptor 1Y, and the latent image is developed with the yellow toner. . The photoreceptor 1Y on which the yellow toner image is formed continues to run at a predetermined speed, and the toner image developed on the photoreceptor 1Y is conveyed to a predetermined primary transfer position.

When the yellow toner image on the photoconductor 1Y is conveyed to the primary transfer position, a predetermined primary transfer bias is applied to the primary transfer roller 5Y, and the electrostatic force from the photoconductor 1Y toward the primary transfer roller 5Y generates toner. By acting on the image, the toner image on the photoreceptor 1 </ b> Y is transferred onto the intermediate transfer belt 20. The transfer bias applied at this time has a polarity (+) opposite to the polarity (−) of the toner, and is controlled to about +10 μA by the control unit (not shown) in the first unit 10Y, for example.
On the other hand, the toner remaining on the photoreceptor 1Y is removed and collected by the cleaning device 6Y.

Further, the primary transfer bias applied to the primary transfer rollers 5M, 5C, and 5K after the second unit 10M is also controlled according to the first unit.
Thus, the intermediate transfer belt 20 onto which the yellow toner image has been transferred by the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, and 10K, and the toner images of the respective colors are superimposed and transferred in a multiple manner.

  The intermediate transfer belt 20 onto which the four color toner images have been transferred in multiple layers through the first to fourth units is disposed on the image transfer surface side of the intermediate transfer belt 20 and the support roller 24 in contact with the inner surface of the intermediate transfer belt 20. The secondary transfer roller (secondary transfer means) 26 is connected to a secondary transfer portion. On the other hand, the recording paper (transfer object) P is fed at a predetermined timing into a gap where the secondary transfer roller 26 and the intermediate transfer belt 20 are pressed against each other via a supply mechanism, and a predetermined secondary transfer bias is supported. Applied to the roller 24. The transfer bias applied at this time has the same polarity (−) as the polarity (−) of the toner, and an electrostatic force from the intermediate transfer belt 20 toward the recording paper P is applied to the toner image, and the transfer bias is applied to the intermediate transfer belt 20. The toner image is transferred onto the recording paper P. Note that the secondary transfer bias at this time is determined according to the resistance detected by a resistance detecting means (not shown) for detecting the resistance of the secondary transfer portion, and is voltage-controlled.

Thereafter, the recording paper P is sent to a fixing device (fixing means) 28, where the toner image is heated, and the color-superposed toner image is melted and fixed on the recording paper P. The recording paper P on which the color image has been fixed is carried out toward the discharge unit, and a series of color image forming operations is completed.
The image forming apparatus exemplified above is configured to transfer the toner image onto the recording paper P via the intermediate transfer belt 20, but is not limited to this configuration, and the toner image is directly transferred from the photoconductor. It may be a structure that is transferred to a recording sheet.

<Process cartridge, toner cartridge>
FIG. 2 is a schematic configuration diagram showing a preferred example of a process cartridge containing the electrophotographic developer of the present invention. The process cartridge 200 includes a charging roller 108, a developing device 111, a photosensitive member cleaning device (cleaning unit) 113, an opening 118 for exposure, and an opening 117 for static elimination exposure, and a rail 116. Used, combined, and integrated.
The process cartridge 200 is detachable from an image forming apparatus main body including a transfer device 112, a fixing device 115, and other components not shown, and the image forming apparatus together with the image forming apparatus main body. It constitutes. Incidentally, 300 is a recording sheet.

  The process cartridge shown in FIG. 2 includes a charging device 108, a developing device 111, a cleaning device (cleaning means) 113, an opening 118 for exposure, and an opening 117 for static elimination exposure. These devices can be selectively combined except that it is an essential requirement to accommodate the inventive electrophotographic developer. In the process cartridge of the present invention, in addition to the photoconductor 107, a charging device 108, a developing device 111, a cleaning device (cleaning means) 113, an opening 118 for exposure, and an opening 117 for static elimination exposure are included. At least one selected from the group of

  Next, the toner cartridge of the present invention will be described. The toner cartridge of the present invention is detachably attached to the image forming apparatus, and at least the toner cartridge for storing the developer to be supplied to the developing means provided in the image forming apparatus is described above. It is an electrophotographic developer of the present invention.

  The image forming apparatus shown in FIG. 1 is an image forming apparatus having a configuration in which the toner cartridges 8Y, 8M, 8C, and 8K can be attached and detached, and the developing devices 4Y, 4M, 4C, and 4K are respectively the developing devices ( Are connected to a toner cartridge corresponding to (color) by a developer supply pipe (not shown). Further, when the amount of developer stored in the toner cartridge is reduced, the toner cartridge can be replaced.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these. Further, unless otherwise specified, all “parts” indicate “parts by mass”.

≪Synthesis of crystalline polyester≫
Synthesis Example 1 <Synthesis of Crystalline Resin A1>
230.3 parts of dodecanedioic acid, 174.28 parts of 1,10-decanediol and 0.12 part of dibutyltin oxide were stirred at 180 ° C. for 6 hours in a nitrogen atmosphere. Thereafter, the mixture was stirred for 4 hours while reducing the pressure to obtain a crystalline resin (A1) having a weight average molecular weight Mw = 16700 and a number average molecular weight Mn = 6500. The ester concentration was 0.083 and the melting point mp was 86 ° C.

Synthesis Example 2 <Synthesis of Crystalline Resin A2>
230.3 parts of dodecanedioic acid, 160.3 parts of 1,9-nonanediol, and 0.12 part of dibutyltin oxide were stirred at 180 ° C. for 6 hours in a nitrogen atmosphere. Thereafter, the mixture was stirred for 4 hours while reducing the pressure to obtain a crystalline resin (A2) having a weight average molecular weight Mw = 24200 and a number average molecular weight Mn = 9900. The ester concentration was 0.087 and the melting point mp was 77 ° C.

Synthesis Example 3 <Synthesis of Crystalline Resin A3>
248 parts of tetradecanedioic acid, 118.17 parts of 1,6-hexanediol and 0.12 part of dibutyltin oxide were stirred at 180 ° C. for 6 hours in a nitrogen atmosphere. Thereafter, the mixture was stirred for 4 hours while reducing the pressure to obtain a crystalline resin (A3) having a weight average molecular weight Mw = 25500 and a number average molecular weight Mn = 10400. The ester concentration was 0.091, and the melting point mp was 75 ° C.

≪Synthesis of amorphous polyester≫
Synthesis Example 1 <Synthesis of Amorphous Resin B1>
Under a nitrogen atmosphere, 97.09 parts of dimethyl terephthalate, 97.09 parts of dimethyl isophthalate, 241.01 parts of bisphenol A propylene oxide adduct, 48.09 parts of 1,9-nonanediol, and 0.12 part of dibutyltin oxide Stir at 180 ° C. for 6 hours. After stirring for 4 hours while reducing the pressure, 8 parts of trimellitic anhydride was added and the mixture was further stirred for 1.5 hours. An amorphous resin (B1) having a weight average molecular weight Mw = 30600 and a number average molecular weight Mn = 7100 was obtained. The glass transition point was 52 ° C.

Synthesis Example 2 <Synthesis of Amorphous Resin B2>
In a nitrogen atmosphere, 97.09 parts of dimethyl terephthalate, 97.09 parts of dimethyl isophthalate, 275.44 parts of bisphenol A propylene oxide adduct, 32.06 parts of 1,9-nonanediol, and 0.12 part of dibutyltin oxide Stir at 180 ° C. for 6 hours. After stirring for 4 hours while reducing the pressure, 8 parts of trimellitic anhydride was added and the mixture was further stirred for 1.5 hours. An amorphous resin (B2) having a weight average molecular weight Mw = 35300 and a number average molecular weight Mn = 6800 was obtained. The glass transition point was 59 ° C.

Synthesis Example 3 <Synthesis of Amorphous Resin B3>
Under a nitrogen atmosphere, 97.09 parts of dimethyl terephthalate, 97.09 parts of dimethyl isophthalate, 309.87 parts of bisphenol A propylene oxide adduct, 16.03 parts of 1,9-nonanediol, and 0.12 part of dibutyltin oxide Stir at 180 ° C. for 6 hours. After stirring for 4 hours while reducing the pressure, 8 parts of trimellitic anhydride was added and the mixture was further stirred for 1.5 hours. An amorphous resin (B3) having a weight average molecular weight Mw = 33800 and a number average molecular weight Mn = 6400 was obtained. The glass transition point was 67 ° C.

Synthesis Example 4 <Synthesis of Amorphous Resin B4>
97.09 parts dimethyl terephthalate, 97.09 parts dimethyl isophthalate, 137.72 parts bisphenol A propylene oxide adduct, 126.52 parts bisphenol A ethylene oxide adduct, 34.856 parts 1,10-decanediol, dibutyltin oxide 0.12 part was stirred at 180 ° C. for 6 hours under a nitrogen atmosphere. After stirring for 4 hours while reducing the pressure, 8 parts of trimellitic anhydride was added and the mixture was further stirred for 1.5 hours. An amorphous resin (B4) having a weight average molecular weight Mw = 36900 and a number average molecular weight Mn = 7200 was obtained. The glass transition point was 55 ° C.

Synthesis Example 5 <Synthesis of Amorphous Resin B5>
In a nitrogen atmosphere, 97.09 parts of dimethyl terephthalate, 97.09 parts of dimethyl isophthalate, 253.04 parts of bisphenol A ethylene oxide adduct, 32.06 parts of 1,9-nonanediol, and 0.12 part of dibutyltin oxide were added under a nitrogen atmosphere. Stir at 6 ° C. for 6 hours. After stirring for 4 hours while reducing the pressure, 8 parts of trimellitic anhydride was added and the mixture was further stirred for 1.5 hours. An amorphous resin (B5) having a weight average molecular weight Mw = 32300 and a number average molecular weight Mn = 6100 was obtained. The glass transition point was 59 ° C.

Synthesis Example 6 <Synthesis of Amorphous Resin B6>
97.09 parts dimethyl terephthalate, 58.254 parts dimethyl isophthalate, 46.06 parts dodecanedioic acid, 158.15 parts bisphenol A ethylene oxide adduct, 154.953 parts bisphenol A propylene oxide adduct, 1,9-nonane 8.015 parts of diol and 0.12 parts of dibutyltin oxide were stirred at 180 ° C. for 6 hours in a nitrogen atmosphere. After stirring for 4 hours while reducing the pressure, 8 parts of trimellitic anhydride was added and the mixture was further stirred for 1.5 hours. An amorphous resin (B6) having a weight average molecular weight Mw = 34700 and a number average molecular weight Mn = 6700 was obtained. The glass transition point was 67 ° C.

Synthesis Example 7 <Synthesis of Amorphous Resin B7>
97.09 parts dimethyl terephthalate, 97.09 parts dimethyl isophthalate, 94.89 parts bisphenol A ethylene oxide adduct, 103.29 parts bisphenol A propylene oxide adduct, 64.12 parts 1,9-nonanediol, dibutyltin oxide 0.12 part was stirred at 180 ° C. for 6 hours under a nitrogen atmosphere. After stirring for 4 hours while reducing the pressure, 8 parts of trimellitic anhydride was added and the mixture was further stirred for 1.5 hours. An amorphous resin (B7) having a weight average molecular weight Mw = 33900 and a number average molecular weight Mn = 6200 was obtained. The glass transition point was 45 ° C.

Synthesis Example 8 <Synthesis of amorphous resin B8>
97.09 parts dimethyl terephthalate, 97.09 parts dimethyl isophthalate, 31.63 parts bisphenol A ethylene oxide adduct, 34.43 parts bisphenol A propylene oxide adduct, 62.49 parts neopentyl glycol, 1,9-nonane Diol 32.06 parts and dibutyltin oxide 0.12 parts were stirred at 180 ° C. for 6 hours in a nitrogen atmosphere. After stirring for 4 hours while reducing the pressure, 8 parts of trimellitic anhydride was added and the mixture was further stirred for 1.5 hours. An amorphous resin (B8) having a weight average molecular weight Mw = 36500 and a number average molecular weight Mn = 6400 was obtained. The glass transition point was 59 ° C.

  The composition, physical properties, etc. of the above crystalline resin and amorphous resin are shown in Table 1, Table 2, and Table 3. In the table, “RO adduct content of bisphenol A” is the content of alkylene oxide adduct of bisphenol A in the alcohol component, and “linear aliphatic diol content” is 8 or more carbon atoms in the alcohol component. A linear aliphatic diol content of 20 or less, “EO adduct” represents an ethylene oxide adduct, and “PO adduct” represents a propylene oxide adduct.

≪Preparation of emulsion≫
<Emulsion Preparation Example C1>
After dissolving 50 parts of crystalline resin A1 in 250 parts of ethyl acetate, adding a solution of 2 parts of anionic surfactant Dowfax in 300 parts of ion-exchanged water, and stirring for 10 minutes at 8000 rpm using an ultra turrax Then, ethyl acetate was distilled off to obtain a crystalline resin emulsion (C1) having a volume average particle size of 0.20 μm.

<Emulsified liquid preparation examples C2 to C3>
Crystalline resin emulsions (C2) and (C3) were obtained according to the method described in Emulsion Preparation Example C1, except that the crystalline resin A1 was changed to the crystalline resins A2 and A3. The volume average particle size of the crystalline resin emulsion (C2) was 0.19 μm, and the volume average particle size of the crystalline resin emulsion (C3) was 0.20 μm.

<Emulsified liquid preparation examples D1 to D8>
Non-crystalline resin emulsions (D1) to (D8) were obtained according to the method described in Emulsion Preparation Example C1, except that the crystalline resin A1 was changed to non-crystalline resins B1 to B8.
About the above emulsion, it describes in Table 4 and Table 5.

≪Preparation of pigment dispersion≫
The following composition was mixed and dissolved, and dispersed by a homogenizer (manufactured by IKA, Ultra Turrax T50) and ultrasonic irradiation to obtain a blue pigment dispersion having a volume average particle diameter of 150 nm.
Cyan pigment C.I. I. Pigment Blue 15: 3
(Copper phthalocyanine, manufactured by Dainippon Ink & Co., Inc.) 50 parts ・ Anionic surfactant Neogen SC 5 parts ・ Ion-exchanged water 200 parts

≪Preparation of mold release agent dispersion≫
The following composition was mixed, heated to 97 ° C., and then dispersed with a homogenizer (manufactured by IKA, Ultra Turrax T50). Thereafter, the mixture was dispersed with a gorin homogenizer (manufactured by Reiwa Shoji) and treated 20 times under the conditions of 105 ° C. and 550 kg / cm ² to obtain fine particles, thereby obtaining a release agent dispersion having a volume average particle diameter of 190 nm. .
・ Wax (WEP-5, manufactured by NOF Corporation) 50 parts ・ Anionic surfactant Neogen SC 5 parts ・ Ion-exchanged water 200 parts

<< Production of toner >>
[Example 1]
-Preparation of toner for electrophotography (1)-
First, as a first step, the following composition is mixed and dispersed in a round stainless steel flask with a homogenizer (IKA, Ultra Turrax T50), and then heated and stirred to 45 ° C. while stirring the contents in the flask. And kept at 45 ° C. for 30 minutes.
・ Crystalline resin emulsion (C1) 100 parts ・ Amorphous resin emulsion (D1) 600 parts ・ Ion exchange water 100 parts ・ Pigment dispersion 25 parts ・ Releasing agent dispersion 40 parts ・ 10 mass% polyaluminum chloride Aqueous solution (Asada Chemical Co., Ltd.) 1.5 parts

  Thereafter, as a second step, 300 parts of an additional amorphous resin emulsion (D1) was added, and the temperature of the obtained contents was gradually increased to 55 ° C. When the obtained contents were observed with an optical microscope, it was confirmed that aggregated particles having a particle diameter of 6.5 μm were produced. Adjust the pH to 8 with aqueous sodium hydroxide, then raise the temperature to 90 ° C, coalesce the aggregates over 1 hour, cool, filter, thoroughly wash with ion-exchanged water, and dry Thus, an electrophotographic toner (1) was obtained. When the particle size of the electrophotographic toner (1) was measured with a Coulter counter (manufactured by Beckman Coulter, Inc.), the volume average particle size was 6.3 μm. GSDv, which is an index of volume particle size distribution, was 1.23.

-Production of developer (1)-
The toner (1) particles were obtained by treating 0.5% by mass of hexamethyldisilazane-treated silica (average particle size of 40 nm) as an external additive and treating the metatitanic acid with 50% by mass of isobutyltrimethoxysilane and firing. Add 0.7% by mass of titanium compound (average particle size 30 nm) (both to toner ratio), mix for 10 minutes with 75 L Henschel mixer, and then sieve with wind sieving machine high voltor 300 (manufactured by Shin Tokyo Machinery Co., Ltd.). Thus, an externally added toner was produced.
For 100 parts of ferrite core having an average particle size of 50 μm, 0.15 parts of vinylidene fluoride and 1.35 parts of a copolymer of methyl methacrylate and trifluoroethylene (polymerization mass ratio 80:20) The carrier was prepared by coating using a kneader apparatus. The obtained carrier and the externally added toner were mixed in a ratio of 100 parts: 8 parts by a 2 liter V blender to prepare a developer (1).

-Evaluation of image scratch resistance-
The produced developer (1) is a mirror-coated paper (basis weight 157) manufactured by Fuji Xerox Co., Ltd. using a DCC500 remodeling machine manufactured by Fuji Xerox (modified using an external fixing device with a variable fixing temperature). The solid image was formed by adjusting the toner applied amount to 15.0 g / m ² at 30 × 30 mm. After image formation, the image was fixed using an external fixing device at a temperature of 150 ° C., a contact area (so-called Nip) of 6.5 mm, and a fixing speed of 180 mm / sec.
The fixed image was performed using SURFACE PROPERTY TESTER (type: 14DR) manufactured by HEIDON. A sapphire needle having a diameter of 0.4 mm was attached, and the image was rubbed at a moving speed of 1500 mm / min and a load of 1000 gf. The image was rubbed three times with the same operation, the average image streak state was visually confirmed, and the following ranking was performed.
Grade 1: The traces are clearly observed in a linear form. Grade 2: The traces are observed intermittently or in a slightly linear form. Grade 3: The traces are observed in 4-10 points. Grade 4. : 1 to 3 shavings are observed in the form of dots Grade 5: No shavings are observed

[Example 2]
An electrophotographic toner (2) and a developer (2) are obtained according to the method described in Example 1 except that the amorphous resin emulsion D1 is changed to the amorphous resin emulsion D2, and image scratch resistance is obtained. An evaluation test was conducted.

[Example 3]
According to the method described in Example 1 except that the amorphous resin emulsion D1 is changed to the amorphous resin emulsion D3, an electrophotographic toner (3) and a developer (3) are obtained, and image scratch resistance is obtained. An evaluation test was conducted.

[Example 4]
An electrophotographic toner (4) and a developer (4) are obtained according to the method described in Example 1 except that the amorphous resin emulsion D1 is changed to the amorphous resin emulsion D4, and image scratch resistance is obtained. An evaluation test was conducted.

[Example 5]
An electrophotographic toner (5) and a developer (5) are obtained according to the method described in Example 1 except that the amorphous resin emulsion D1 is changed to the amorphous resin emulsion D5, and image scratch resistance is obtained. An evaluation test was conducted.

[Example 6]
According to the method described in Example 1, except that the amorphous resin emulsion D1 is changed to the amorphous resin emulsion D5 and the amount of the emulsion mixed in the first stage is changed as follows. Toner (6) and developer (6) were obtained, and an image scratch resistance evaluation test was performed.
・ Crystalline resin emulsion (C1) 200 parts ・ Amorphous resin emulsion (D5) 500 parts

[Example 7]
The crystalline resin emulsion C1 was changed to the crystalline resin emulsion C2, the amorphous resin emulsion D1 was changed to the amorphous resin emulsion D5, and the amount of the emulsion mixed in the first stage was changed as follows. Except for the above, according to the method described in Example 1, an electrophotographic toner (7) and a developer (7) were obtained, and an image scratch resistance evaluation test was performed.
・ Crystalline resin emulsion (C2) 150 parts ・ Amorphous resin emulsion (D5) 550 parts

[Example 8]
The crystalline resin emulsion C1 was changed to the crystalline resin emulsion C2, the amorphous resin emulsion D1 was changed to the amorphous resin emulsion D5, and the amount of the emulsion mixed in the first stage was changed as follows. Except for the above, in accordance with the method described in Example 1, an electrophotographic toner (8) and a developer (8) were obtained, and an image scratch resistance evaluation test was performed.
・ Crystalline resin emulsion (C2) 100 parts ・ Amorphous resin emulsion (D5) 600 parts

[Comparative Example 1]
An electrophotographic toner (9) and a developer (9) were obtained according to the method described in Example 1 except that the amount of the emulsified liquid to be mixed in the first stage was changed as follows, and an image scratch resistance evaluation test Went.
・ Crystalline resin emulsion (C1) 300 parts ・ Amorphous resin emulsion (D1) 400 parts

[Comparative Example 2]
An electrophotographic toner (10) and a developer (10) are obtained according to the method described in Example 1 except that the amount of the emulsified liquid to be mixed in the first stage is changed as follows, and an image scratch resistance evaluation test Went.
・ Crystalline resin emulsion (C1) 400 parts ・ Amorphous resin emulsion (D1) 300 parts

[Comparative Example 3]
According to the method described in Example 1 except that the crystalline resin emulsion C1 is changed to the crystalline resin emulsion C2 and the amorphous resin emulsion D1 is changed to the amorphous resin emulsion D6, an electrophotographic toner ( 11) and developer (11) were obtained, and an image scratch resistance evaluation test was performed.

[Comparative Example 4]
According to the method described in Example 1, except that the crystalline resin emulsion C1 is changed to the crystalline resin emulsion C3 and the amorphous resin emulsion D1 is changed to the amorphous resin emulsion D7, an electrophotographic toner ( 12) and developer (12) were obtained, and an image scratch resistance evaluation test was performed.

[Comparative Example 5]
An electrophotographic toner (13) and a developer (13) are obtained according to the method described in Example 1 except that the amorphous resin emulsion D1 is changed to the amorphous resin emulsion D8, and image scratch resistance is obtained. An evaluation test was conducted.

  Tables 6 and 7 show the evaluation results of the volume average particle diameter, GSDv, and image scratch resistance of the toner.

Below, the preferable aspect of this invention is shown. First, the toner for electrophotography of the present invention is:
<1> Synthesize at least a colorant, a crystalline polyester having an ester concentration M represented by the following formula 1 of 0.07 ≦ M ≦ 0.09, an alcohol component and an acid component, Of these, an amorphous oxide in which an alkylene oxide adduct of bisphenol A is used in an amount of 50 mol% to 90 mol%, and among the alcohol components, a linear aliphatic diol having 8 to 20 carbon atoms is used in an amount of 10 mol% to 30 mol%. The content ratio (mass ratio) of the non-crystalline polyester and the crystalline polyester is 75:25 to 98: 2.
(Formula 1) Ester concentration (M) = K / A
(In Formula 1, K represents the number of ester groups in the polyester, and A represents the number of atoms constituting the polymer chain of the polyester.)
By adopting such a configuration, it is possible to obtain an image having excellent scratch resistance as compared with the case without this configuration.
<2> Among the alcohol components according to <1>, the amount of the alkylene oxide adduct of bisphenol A is preferably 60 mol% or more and 85 mol% or less. By adopting such a configuration, it is possible to more suitably obtain an image excellent in scratch resistance as compared with the case where this configuration is not provided.
<3> Of the alcohol components according to <1> or <2>, the amount of the linear aliphatic diol is preferably 15 mol% or more and 25 mol% or less. By adopting such a configuration, an image excellent in scratch resistance can be obtained more suitably than in the case where the present configuration is not provided, and the glass transition point of the resin can be easily controlled by a preferable region.
<4> The content ratio (mass ratio) between the amorphous polyester and the crystalline polyester described in any one of the above items <1> to <3> is preferably 85:15 to 98: 2. By adopting such a configuration, it is possible to control the charge amount to a more suitable range and to obtain better low-temperature fixability as compared with the case without this configuration.
<5> The toner for electrophotography according to any one of <1> to <4> is produced by aggregating and combining crystalline polyester particles, amorphous polyester particles, and colorant particles. It is preferable. By adopting such a configuration, it is possible to provide an electrophotographic toner having a uniform particle diameter as compared with the case where the present configuration is not provided, and an image with higher image quality can be obtained.

The electrophotographic developer of the present invention is
<6> The electrophotographic toner according to any one of <1> to <5>. By adopting such a configuration, it is possible to obtain an image having excellent scratch resistance as compared with the case without this configuration.

The toner cartridge of the present invention is
<7> The developer described in <6>, wherein the developer is detachable from an image forming apparatus including at least a developing unit that develops an electrostatic latent image to form a toner image, and is supplied to the developing unit. The electrophotographic developer is housed. By adopting such a configuration, it is possible to facilitate the supply of an electrophotographic toner capable of obtaining an image having excellent scratch resistance as compared with the case where the present configuration is not provided, and to improve the maintainability of the above characteristics.

The process cartridge of the present invention is
<8> A developer holding member is provided at least, and the electrophotographic developer according to <6> is accommodated. By adopting such a configuration, it is possible to easily handle an electrophotographic developer capable of obtaining an image excellent in scratch resistance as compared with the case without this configuration, and adaptability to image forming apparatuses having various configurations. Can be increased.

The image forming apparatus according to the present invention includes:
<9> A latent image holding member, latent image forming means for forming an electrostatic latent image on the surface of the latent image holding member, and developing the electrostatic latent image with the electrophotographic developer according to <6>. Development means for forming a toner image, transfer means for transferring the toner image to the surface of the transfer target, and fixing means for fixing the toner image transferred to the surface of the transfer target. To do. With this configuration, it is possible to obtain an image excellent in scratch resistance as compared with the case where this configuration is not provided.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus of the present invention. It is a schematic block diagram which shows an example of the process cartridge of this invention.

Explanation of symbols

1Y, 1M, 1C, 1K, 107 photoconductor (image carrier)
2Y, 2M, 2C, 2K, 108 Charging roller 3Y, 3M, 3C, 3K Laser beam 3 Exposure device 4Y, 4M, 4C, 4K, 111 Developing device (developing means)
5Y, 5M, 5C, 5K Primary transfer rollers 6Y, 6M, 6C, 6K, 113 Photoconductor cleaning device (cleaning means)
8Y, 8M, 8C, 8K Toner cartridges 10Y, 10M, 10C, 10K Unit 20 Intermediate transfer belt 22 Drive roller 24 Support roller 26 Secondary transfer roller (transfer means)
28,115 Fixing device (fixing means)
30 Intermediate transfer member cleaning device 112 Transfer device 116 Mounting rail 117 Opening portion 118 for static elimination exposure Opening portion 200 for exposure Process cartridge,
P, 300 recording paper (transfer object)

Claims (8)

At least with a colorant,
A crystalline polyester having an ester concentration M represented by the following formula 1 of 0.07 ≦ M ≦ 0.09;
A straight chain fat comprising an alcohol component and an acid component synthesized, an alkylene oxide adduct of bisphenol A of 50 mol% to 90 mol% of the alcohol component, and a straight chain fat having 8 to 20 carbon atoms of the alcohol component. An amorphous polyester using 10 mol% or more and 30 mol% or less of a group diol,
An electrophotographic toner, wherein a content ratio (mass ratio) of the amorphous polyester and the crystalline polyester is 75:25 to 98: 2.
(Formula 1) Ester concentration (M) = K / A
(In Formula 1, K represents the number of ester groups in the polyester, and A represents the number of atoms constituting the polymer chain of the polyester.)   2. The electrophotographic toner according to claim 1, wherein the amount of the alkylene oxide adduct of bisphenol A in the alcohol component is 60 mol% or more and 85 mol% or less.   3. The electrophotographic toner according to claim 1, wherein an amount of the linear aliphatic diol in the alcohol component is 15 mol% or more and 25 mol% or less.   The toner for electrophotography according to any one of claims 1 to 3, wherein the toner is produced by aggregating and uniting crystalline polyester particles, non-crystalline polyester particles, and colorant particles.   An electrophotographic developer comprising the electrophotographic toner according to claim 1.   6. The electrophotographic apparatus according to claim 5, wherein the developer is detachable from an image forming apparatus including at least a developing unit that develops an electrostatic latent image to form a toner image, and the developer is supplied to the developing unit. A toner cartridge for storing a developer.   6. A process cartridge comprising at least a developer holder and containing the electrophotographic developer according to claim 5.   A latent image holding member, latent image forming means for forming an electrostatic latent image on the surface of the latent image holding member, and developing the electrostatic latent image with the electrophotographic developer according to claim 5 to form a toner image. An image forming apparatus comprising: a developing unit that forms; a transfer unit that transfers the toner image to the surface of the transfer target; and a fixing unit that fixes the toner image transferred to the surface of the transfer target. .

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