JP5418017B2 - 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.

  A method of visualizing image information through an electrostatic latent image such as electrophotography is currently used in various fields. In electrophotography, an electrostatic latent image formed on a photoreceptor by a charging process and an exposure process is developed with a developer containing toner, and visualized through a transfer process and a fixing process.

  Developers used for development include a two-component developer containing toner and a carrier and a one-component developer used alone, such as a magnetic toner, but the two-component developer has a carrier as the developer. Since the functions such as stirring, transport and charging are shared and the functions are separated as a developer, the controllability is good, and it is widely used at present.

  Further, a toner in which polytetrafluoroethylene is externally added is disclosed (for example, see Patent Documents 1 and 2).

JP-A-8-184984 JP 2000-305311 A

  It is an object of the present invention to provide an electrophotographic toner that suppresses the cleaning failure of toner remaining on the surface of a latent image holding member without being transferred and the occurrence of unevenness in a halftone image.

The above problems have been solved by the present invention described below.
That is, the invention according to claim 1
Toner particles containing at least a binder resin and a release agent, and particles containing polytetrafluoroethylene and particles containing metatitanic acid as external additives,
The amount of polytetrafluoroethylene adhering to the toner particles determined by fluorescent X-ray analysis is A, and the toner is dispersed in a 2% by weight aqueous surfactant solution. in after adding 1 hour vibration was determined by X-ray fluorescence analysis, when the detected amount of polytetrafluoroethylene adhered to the toner particles is B, meets a relation of the following formula (1),
The particles containing metatitanic acid have a content of 0.9 parts by mass to 1.2 parts by mass with respect to 100 parts by mass of the toner particles, and a particle size of 15 nm to 35 nm. The toner for electrophotography.
Formula (1)
(A−B) / A × 100 ≦ 5 [%]

The invention according to claim 2
An electrophotographic developer comprising at least the electrophotographic toner according to claim 1 .

The invention according to claim 3
A toner cartridge which is attached to and detached from an image forming apparatus and contains toner to be supplied to a developing unit provided in the image forming apparatus, wherein the toner is the electrophotographic toner according to claim 1. It is.

The invention according to claim 4
A process cartridge comprising at least a developer holding member and containing the electrophotographic developer according to claim 2 .

The invention according to claim 5
A latent image holder, developing means for developing the electrostatic latent image formed on the latent image holder with the electrophotographic developer according to claim 2 to form a toner image, and the latent image holder Transfer means for transferring the toner image formed thereon onto the transfer member, fixing means for fixing the toner image transferred onto the transfer member, and the surface of the latent image holding member remaining without being transferred An image forming apparatus comprising: a cleaning unit that cleans components.

According to the first aspect of the present invention, compared to the case where the relationship of the expression (1) is not satisfied, the cleaning of the toner remaining on the surface of the latent image holding member without being transferred and the occurrence of unevenness in the halftone image are caused. Inhibiting electrophotographic toners are provided.
According to the first aspect of the present invention, the effect of suppressing the occurrence of unevenness in the halftone image is remarkable as compared with the case where the particles containing metatitanic acid are not externally added.

According to the second aspect of the present invention, as compared with the case where the toner satisfying the relationship of the above formula (1) is not included, the cleaning of the toner remaining on the surface of the latent image holding member without being transferred and the unevenness of the halftone image are reduced. An electrophotographic developer that suppresses the occurrence of the above is provided.
According to the third aspect of the present invention, as compared with the case where no toner satisfying the relationship of the formula (1) is contained, the cleaning failure of the toner remaining on the surface of the latent image holding member without being transferred, and the halftone image A toner cartridge containing an electrophotographic toner that suppresses the occurrence of unevenness is provided.

According to the fourth aspect of the present invention, compared with the case where the developer containing the toner satisfying the relationship of the formula (1) is not stored, the cleaning property of the toner remaining without being transferred on the surface of the latent image holding member is improved. While maintaining, halftone image unevenness is suppressed.
According to the fifth aspect of the present invention, the surface of the latent image holding member is not transferred as compared with the case where the developing means for forming the toner image with the developer containing the toner satisfying the relationship of the formula (1) is not provided. This prevents the residual toner from being poorly cleaned and the occurrence of unevenness in the halftone image.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment. It is a schematic block diagram which shows an example of the process cartridge which concerns on this embodiment.

  Hereinafter, embodiments of an electrophotographic toner, an electrophotographic developer, a toner cartridge, a process cartridge, and an image forming apparatus according to the present invention will be described in detail.

<Toner for electrophotography>
The electrophotographic toner according to the present embodiment (hereinafter, sometimes simply referred to as “the toner according to the present embodiment”) includes toner particles containing at least a binder resin and a release agent, and a polyester as an external additive. In a surfactant aqueous solution containing 2% by mass of A, the detected amount of polytetrafluoroethylene adhering to the toner particles determined by fluorescent X-ray analysis was obtained. When the detected amount of polytetrafluoroethylene adhering to the toner particles obtained by fluorescent X-ray analysis after applying ultrasonic vibration with an output of 60 W and a frequency of 20 kHz for 1 hour after dispersion is B, It is characterized by satisfying the relationship of the following formula (1). However, the toner according to the exemplary embodiment further includes, as an external additive, a content of 0.9 parts by mass or more and 1.2 parts by mass or less with respect to 100 parts by mass of the toner particles, and a particle diameter of 15 nm or more. It contains particles containing metatitanic acid that are 35 nm or less. In addition, it is applied to the toner according to the exemplary embodiment that the following formula (1) is 5% or less.
Formula (1)
(A-B) / A × 100 ≦ 10%

When polytetrafluoroethylene particles are used as the external additive, the occurrence of poor cleaning of the toner remaining on the surface of the latent image holding member without being transferred is suppressed. However, unevenness tends to occur in the halftone image.
The cause of unevenness in the halftone image is considered as follows.
(1) Part of the polytetrafluoroethylene particles used as the external additive is peeled off from the toner particles.
(2) The peeled polytetrafluoroethylene particles adhere to the surface of the latent image holding member.
(3) When this amount increases to some extent, when a halftone image is formed, light scattering occurs when the latent image is formed by exposure, and the latent image is blurred.
(4) Therefore, good fine lines are not formed on the transfer target (the fine lines are partially thin and thick).
(5) As a result, unevenness occurs in the halftone image.

  The toner according to the exemplary embodiment satisfies the relationship of the formula (1). Here, “(A−B) / A × 100” in the formula (1) indicates a rate at which particles containing polytetrafluoroethylene are peeled off by ultrasonic vibration, and this value is 10% or less. When it is, it shows that the peeling rate of the particle | grains containing a polytetrafluoroethylene is small. If this value exceeds 10%, there are many particles containing polytetrafluoroethylene from the toner particles at the contact portion between the latent image holding member and the developer holding member or at the contact portion between the latent image holding member and the cleaning means. As a result, particles containing polytetrafluoroethylene adhere to the surface of the latent image holding member, and unevenness occurs in the halftone image.

In the toner according to the present embodiment, since “(A−B) / A × 100” is 10% or less, occurrence of unevenness in a halftone image is suppressed. This is considered to be because satisfying the relationship of the formula (1) prevents the particles containing polytetrafluoroethylene from being peeled off from the toner particles, and the phenomena (2) to (5) do not occur. .
As a result, there is provided an electrophotographic toner that suppresses the cleaning failure of the toner remaining on the surface of the latent image holding member without being transferred and the occurrence of unevenness in the halftone image.
The “(A−B) / A × 100” is preferably smaller in terms of the effect of forming a halftone image without unevenness, and is preferably 7% or less, for example. More preferably, it is 5% or less.

As a specific method for bringing the “(A−B) / A × 100” within the scope of the present application, for example, a method of controlling according to external addition conditions can be cited. Particles containing polytetrafluoroethylene have a low surface energy and a density lower than that of silica or the like. For this reason, it hardly adheres to the surface and is hardly embedded in the toner surface. For this reason, it is necessary to adhere to a strong condition to some extent, but if it is too strong, the particles containing polytetrafluoroethylene will not be deformed and will not be effective, and other metal oxides will be embedded in the toner surface. It will be.
Therefore, while maintaining the temperature of the particles containing polytetrafluoroethylene to be somewhat low, it is added to the toner particles to make it more likely to adhere before the temperature of the particles containing polytetrafluoroethylene becomes the same as that of the toner. As a result, the value of (A−B) / A × 100 can be controlled more preferably.

Here, the detected amounts A and B of the polytetrafluoroethylene are obtained by the following steps.
(1) 1 g of a measurement sample (toner particles to which particles containing polytetrafluoroethylene are externally added) is molded, and fluorescent X-ray analysis is performed using a fluorescent X-ray analyzer (System 3370, manufactured by Rigaku Corporation). And the detected amount of polytetrafluoroethylene is determined from the detected amount of fluorine atoms to be A.
(2) 2 g of a measurement sample (toner particles to which particles containing polytetrafluoroethylene are externally added) 0.2% by mass of a surfactant (polyoxyethylene octylphenyl ether having a polymerization degree of 10; Wako Pure Chemical Industries, Ltd.) (Product made) Add to 40 ml of aqueous solution and disperse sufficiently so that toner leaks into aqueous solution. In this state, an ultrasonic homogenizer US300T (manufactured by Nippon Seiki Seisakusho) was used, and ultrasonic vibration with an output of 60 W and a frequency of 20 kHz was applied for 1 hour. Then, the toner was separated under a condition of 1000 rpm × 2 minutes through a 50 ml centrifuge with a sedimentation tube (small centrifuge Model M160 IV, manufactured by Sakuma Seisakusho), and the supernatant was removed, followed by washing twice purely.
(3) After the treatment of (2), a fluorescent X-ray analysis is performed on 1 g of the dried measurement sample in the same manner as in (1), and the detected amount of polytetrafluoroethylene is determined as B.

<Toner particles>
The toner particles contain at least a crystalline resin and a release agent, and if necessary, a colorant and other additives.

(Binder resin)
In the toner according to the exemplary embodiment, it is preferable that the binder resin used for the toner particles contains a crystalline resin. By using the crystalline resin, not only the adhesion of particles containing polytetrafluoroethylene can be easily controlled, but also the fixing temperature is lowered, and the temperature of the heating and stirring step described later can be kept low.
As the binder resin used for the toner particles, it is more preferable to use a crystalline resin and an amorphous resin in combination.

  The content ratio of the crystalline resin and the amorphous resin in the toner particles is preferably a mass ratio of crystalline resin: amorphous resin = 4: 96 or more and 20:80 or less, and 6:94 or more and 15: It is more preferably 85 or less, and further preferably 8:92 or more and 10:90 or less.

The “crystalline resin” refers to a resin having a clear endothermic peak, not a stepwise change in endothermic amount in differential scanning calorimetry (DSC). Specifically, it means that the half-value width of the endothermic peak when measured at a heating rate of 10 ° C./min is within 6 ° C.
On the other hand, a resin having a half-value width exceeding 6 ° C. or a resin having no clear endothermic peak means an amorphous resin.

  The crystalline resin is not particularly limited as long as it is a resin having crystallinity, and specific examples include crystalline polyester resins and crystalline vinyl resins. Crystalline polyester resins are preferable, and aliphatic crystals are used. A more preferred polyester resin is more preferred.

  The crystalline polyester resin and all other polyester resins used in the toner according to this embodiment are synthesized from a polyvalent carboxylic acid component and a polyhydric alcohol component. In this embodiment, a commercially available product may be used as the polyester resin, or a synthesized product may be used.

  Examples of the polyvalent carboxylic acid component include oxalic acid, succinic acid, glutaric acid, adipic acid, peric acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12 -Aliphatic dicarboxylic acids such as dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid; phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, mesaconic acid Aromatic dicarboxylic acids such as dibasic acids such as, and the like, and anhydrides and lower alkyl esters thereof are also included, but not limited thereto. These may be used individually by 1 type and may use 2 or more types together.

  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.

Furthermore, the dicarboxylic acid component which has a double bond other than the above-mentioned aliphatic dicarboxylic acid and aromatic dicarboxylic acid is mentioned. A dicarboxylic acid having a double bond is radically cross-linked through the double bond.
Examples of the dicarboxylic acid having a double bond include, but are not limited to, maleic acid, fumaric acid, 3-hexenedioic acid, and 3-octenedioic acid. In addition, these lower esters, acid anhydrides and the like are also included.

  On the other hand, the polyhydric alcohol component is preferably an aliphatic diol, and examples thereof include a linear aliphatic diol having a main chain portion having 7 to 20 carbon atoms. Further, when the carbon number is 7 or more and 20 or less, the melting point when polycondensation with the aromatic dicarboxylic acid is kept low, and low-temperature fixing is realized.

  Specific examples of the aliphatic diol suitably used for the synthesis of the crystalline polyester in the present embodiment include ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,5-pentanediol. 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, Examples include, but are not limited to, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,14-eicosandecanediol, and the like. These may be used individually by 1 type and may use 2 or more types together.

Among these, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable in view of availability.
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.

  Among the polyhydric alcohol components, the content of the aliphatic diol component is preferably 80 mol% or more, and more preferably 90% or more. When the content of the aliphatic diol component is within the above range, the crystallinity of the polyester resin is maintained, and the lowering of the melting point can be suppressed, so that the toner blocking resistance, the image storage stability, and the low-temperature fixability are excellent.

  In addition, in the crystalline polyester in the present embodiment, a monovalent acid such as acetic acid or benzoic acid or a monovalent alcohol such as cyclohexanol benzyl alcohol is used for the purpose of adjusting the acid value or the hydroxyl value, if necessary. May be used.

  There is no restriction | limiting in particular as a manufacturing method of crystalline polyester resin, It manufactures with the general polyester polymerization method which makes an acid component and an alcohol component react. For example, direct polycondensation, transesterification, and the like can be mentioned.

  The production of the crystalline polyester resin can be carried out at a polymerization temperature of 180 ° C. or higher and 230 ° C. or lower, and the reaction system is reduced in pressure as necessary and reacted while removing water and alcohol generated by condensation. When the monomer is not dissolved or compatible with the reaction temperature, a solvent having a high boiling point may be added as a solubilizer and dissolved. In the polycondensation reaction, the dissolution auxiliary solvent is distilled off. When a monomer having poor compatibility exists in the copolymerization reaction, the monomer having poor compatibility and the monomer and the acid or alcohol to be polycondensed are condensed in advance and then polycondensed together with the main component.

  The resin particle dispersion of crystalline polyester is prepared by emulsifying and dispersing the resin by adjusting the acid value of the resin or using an ionic surfactant.

  Catalysts used for the production of crystalline polyester resins include alkali metal compounds such as sodium and lithium; alkaline earth metal compounds such as magnesium and calcium; metals such as zinc, manganese, antimony, titanium, tin, zirconium, and germanium Compounds: Phosphorous acid compounds, phosphoric acid compounds, amine compounds, and the like, and specific examples include the following compounds.

  For example, sodium acetate, sodium carbonate, lithium acetate, lithium carbonate, calcium acetate, calcium stearate, magnesium acetate, zinc acetate, zinc stearate, zinc naphthenate, zinc chloride, manganese acetate, manganese naphthenate, titanium tetraethoxide, titanium Tetrapropoxide, titanium tetraisoproxide, titanium tetrabutoxide, antimony trioxide, triphenylantimony, tributylantimony, tin formate, tin oxalate, tetraphenyltin, dibutyltin dichloride, dibutyltin oxide, diphenyltin oxide, zirconium tetrabutoxide, naphthenic acid Zirconium, zirconyl carbonate, zirconyl acetate, zirconyl stearate, zirconyl octylate, germanium oxide, triphenyl Sufaito, tris (2, 4-t-butylphenyl) phosphite, ethyltriphenylphosphonium bromide, triethylamine, compounds such as triphenyl amine.

On the other hand, crystalline vinyl resins include amyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, and (meth) acrylic acid. Decyl, undecyl (meth) acrylate, tridecyl (meth) acrylate, myristyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, oleyl (meth) acrylate, behenyl (meth) acrylate And vinyl resins using long-chain alkyl and alkenyl (meth) acrylic acid esters.
In the present specification, the description “(meth) acryl” means to include both “acryl” and “methacryl”.

The melting temperature of the crystalline resin is preferably 50 ° C. or higher and 100 ° C. or lower, more preferably 60 ° C. or higher and 80 ° C. or lower, and further preferably 55 ° C. or higher and 70 ° C. or lower.
The crystalline resin may show a plurality of melting peaks, but in this embodiment, the maximum peak is regarded as the melting point.

The crystalline resin has a weight average molecular weight (Mw) of preferably from 5,000 to 60,000, more preferably from 8,000 to 50,000, as determined by gel permeation chromatography (GPC) in a tetrahydrofuran (THF) soluble content. More preferably, the number average molecular weight (Mn) is preferably from 4000 to 10,000, the molecular weight distribution Mw / Mn is preferably from 2 to 10, and more preferably from 3 to 9.
When the weight average molecular weight and the number average molecular weight are within the above ranges, it is easy to achieve both low-temperature fixability and hot offset resistance.

The crystalline resin is preferably used in the range of 5% by mass to 30% by mass and more preferably in the range of 8% by mass to 20% by mass among the components constituting the toner particles.
If the content of the crystalline resin is in the above range, the strength of the fixed image, particularly scratching strength, is high and scratches are difficult to be obtained, and sharp melt properties derived from the crystalline resin are obtained, ensuring low-temperature fixability. On the other hand, toner blocking resistance and image storage stability are exhibited.

  A known resin material is used as the crystalline resin used together with the above-described crystalline resin as the binder resin of the toner according to the exemplary embodiment, but an amorphous polyester resin is particularly preferable. The amorphous polyester resin that can be used in the present embodiment is obtained mainly by condensation polymerization of polyvalent carboxylic acids and polyhydric alcohols.

When an amorphous polyester resin is used, it is advantageous in that the resin particle dispersion can be easily prepared by adjusting the acid value of the resin or emulsifying and dispersing the resin using an ionic surfactant.
Examples of polyvalent carboxylic acids include aromatic carboxylic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, naphthalene dicarboxylic acid; maleic anhydride, fumaric acid, succinic acid, alkenyl And aliphatic carboxylic acids such as succinic anhydride and adipic acid; and alicyclic carboxylic acids such as cyclohexanedicarboxylic acid. These polyvalent carboxylic acids may be used alone or in combination of two or more.

  Of these polyvalent carboxylic acids, aromatic carboxylic acids are preferably used, and trivalent or higher carboxylic acids (trimerits) together with dicarboxylic acids to form a crosslinked structure or a branched structure in order to ensure good fixability. It is preferable to use an acid or an acid anhydride thereof in combination.

  Examples of polyhydric alcohols include aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, glycerin; cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A And the like; and aromatic diols such as bisphenol A ethylene oxide adduct and bisphenol A propylene oxide adduct. One or more of these polyhydric alcohols may be used.

  Of these polyhydric alcohols, aromatic diols and alicyclic diols are preferred, and among these, aromatic diols are more preferred. In order to secure good fixing properties, a trihydric or higher polyhydric alcohol (glycerin, trimethylolpropane, pentaerythritol) may be used in combination with the diol in order to take a crosslinked structure or a branched structure.

  In addition, monocarboxylic acid and / or monoalcohol is further added to the polyester resin obtained by polycondensation of polycarboxylic acid and polyhydric alcohol to esterify the hydroxyl group and / or carboxyl group at the polymerization terminal. The acid value of the polyester resin may be adjusted.

  Examples of the monocarboxylic acid include acetic acid, acetic anhydride, benzoic acid, trichloroacetic acid, trifluoroacetic acid, propionic anhydride, etc., and examples of the monoalcohol include methanol, ethanol, propanol, octanol, 2-ethylhexanol, trifluoroethanol, Examples include trichloroethanol, hexafluoroisopropanol, and phenol.

  The polyester resin is produced by subjecting the polyhydric alcohol and polyhydric carboxylic acid to a condensation reaction according to a conventional method. For example, the above polyhydric alcohol and polyvalent carboxylic acid, if necessary, a catalyst, and blended in a reaction vessel equipped with a thermometer, a stirrer, a flow-down condenser, and in the presence of an inert gas (such as nitrogen gas), Heat at 150 ° C. or higher and 250 ° C. or lower to continuously remove by-product low molecular weight compounds from the reaction system, stop the reaction when a predetermined acid value is reached, cool, and target reactant Manufactured by obtaining.

  Examples of the catalyst used for the synthesis of this polyester resin include esterification catalysts such as organic metals such as dibutyltin dilaurate and dibutyltin oxide, and metal alkoxides such as tetrabutyl titanate.

In this embodiment, the amorphous resin used for the toner particles has a weight average molecular weight (Mw) of 5,000 to 1,000,000 by molecular weight measurement by gel permeation chromatography (GPC) method of tetrahydrofuran (THF) soluble content. Preferably, the molecular weight (Mn) is preferably 2000 or more and 10,000 or less, and the molecular weight distribution Mw / Mn is 1.5 or more and 100 or less. Preferably, it is 2 or more and 60 or less.
When the weight average molecular weight and the number average molecular weight are within the above ranges, it is easy to achieve both low-temperature fixability, hot offset resistance, and document storage stability.

  In the present embodiment, the molecular weight of the resin is measured with a THF solvent by using a TSO-soluble GPC / HLC-8120, a Tosoh column / TSKgel SuperHM-M (15 cm), and a monodisperse polystyrene. The molecular weight was calculated using a molecular weight calibration curve prepared with a standard sample.

The acid value of the amorphous polyester resin (mg number of KOH necessary to neutralize 1 g of resin) is easy to obtain the above molecular weight distribution, and it is easy to ensure the granulation property of the toner particles by the emulsion dispersion method. In addition, since it is easy to maintain the environmental stability (stability of chargeability when the temperature and humidity change) of the obtained toner, it is preferably 1 mg KOH / g or more and 30 mg KOH / g or less. .
The acid value of the amorphous polyester resin is adjusted by controlling the carboxyl group at the terminal of the polyester by the blending ratio and reaction rate of the raw material polycarboxylic acid and polyhydric alcohol. Or what has a carboxyl group in the principal chain of polyester is obtained by using trimellitic anhydride as a polyvalent carboxylic acid component.

  Moreover, you may use a styrene acrylic resin as a well-known amorphous resin. Examples of the monomer include styrenes such as styrene, parachlorostyrene, and α-methylstyrene: methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, and acrylic acid. Esters having a vinyl group such as 2-ethylhexyl, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate and 2-ethylhexyl methacrylate: Vinyl nitriles such as acrylonitrile and methacrylonitrile: Vinyl methyl ether Vinyl ethers such as vinyl isobutyl ether: vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc .: polyolefins such as ethylene, propylene, butadiene, etc. A copolymer obtained by combining two or more of these or a mixture thereof, and further, an epoxy resin, a polyester resin, a polyurethane resin, a polyamide resin, a cellulose resin, a polyether resin, a non-vinyl condensation resin, Alternatively, a mixture of these with the vinyl resin, or a graft polymer obtained when polymerizing a vinyl monomer in the presence of these may be used.

The glass transition temperature of the amorphous resin used in the present embodiment is preferably 35 ° C. or higher and 100 ° C. or lower.
The softening temperature of the amorphous resin is preferably in the range of 80 ° C. to 130 ° C., and more preferably in the range of 90 ° C. to 120 ° C.
The softening temperature of the amorphous resin is as follows: flow tester (manufactured by Shimadzu Corporation: CFT-500C), preheating: 80 ° C./300 sec, plunger pressure: 0.980665 MPa, die size: 1 mmΦ × 1 mm, heating rate: 3.0 It refers to an intermediate temperature between the melting start temperature and the melting end temperature under the condition of ° C / min.

  In the present exemplary embodiment, the toner particles include a toner (a toner having a core / shell structure) having a core part that forms the center part of the toner particles and a shell part that exists around the core part.

When the toner particles in the present embodiment use a crystalline resin and an amorphous resin as a binder resin, each resin may exist in any form in the toner. From the standpoint that the crystalline resin on the toner surface is uniform and the chargeability and storage properties are improved, toner particles containing a crystalline resin in the core are preferred.
Furthermore, it is preferable that the core portion contains a crystalline resin and an amorphous resin from the viewpoint of improving the storage stability because the crystalline resin and the amorphous resin are compatible.

  The content ratio of the crystalline resin and the amorphous resin in the core part is preferably a mass ratio of crystalline resin: amorphous resin = 2: 98 or more and 16:84 or less, but 3:97 or more and 16:84. More preferably, it is more preferably 4:96 or more and 15:85 or less.

In the shell part, it is preferable to use an amorphous resin as a binder resin from the viewpoint of preventing the release agent component and the crystalline resin component from being exposed from the core part, and improving the chargeability and storage stability.
The content ratio of the crystalline resin and the amorphous resin in the shell part is preferably a mass ratio of crystalline resin: amorphous resin = 0: 100 or more and 2:98 or less, and 0: 100 or more and 1:99. More preferably, it is 0: 100 or more and 0.5: 99.5 or less.

(Release agent)
As the release agent used for the toner particles in the exemplary embodiment, it is preferable to use a substance having a main maximum peak measured in accordance with ASTM D3418-8 in the range of 80 ° C. or more and 110 ° C. When the main maximum peak is within the above range, not only the value of (A−B) / A × 100 can be easily controlled within the range of the present application, but also the occurrence of offset during fixing and the image surface Excellent gloss. The release agent usually has a glass transition temperature of 0 ° C. or less, and therefore, even a particle having a low density such as a particle containing polytetrafluoroethylene can be easily adhered without deformation. it is conceivable that.

  For the measurement of the main maximum peak, for example, DSC-7 manufactured by Perkin Elmer is used. The temperature correction of the detection part of this apparatus uses the melting point of indium and zinc, and the correction of heat quantity uses the heat of fusion of indium. As the sample, an aluminum pan is used, an empty pan is set as a control, and the measurement is performed at a heating rate of 10 ° C./min.

  Specific examples of the release agent include low molecular weight polyolefins such as paraffin wax, polyethylene, polypropylene, polybutene, silicones having a softening point by heating, oleic acid amide, erucic acid amide, ricinoleic acid amide, stearic acid amide. Fatty acid amides such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil and other plant waxes, animal waxes such as beeswax, montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, fisher Examples thereof include minerals such as Tropsch wax, petroleum-based waxes, and modified products thereof. Of these, low molecular weight polyolefins such as paraffin wax, polyethylene, polypropylene, and polybutene, which have more stable components and can easily control the main maximum peak, are preferable.

  These release agents are dispersed in water together with ionic surfactants, polymer electrolytes such as polymer acids and polymer bases, and heated with a homogenizer or pressure discharge type disperser that can be heated to the melting point or higher and subjected to strong shearing. A release agent dispersion liquid containing particles of release agent having a particle diameter of 1 μm or less is prepared.

  The release agent is preferably used in the range of 0.5% by mass or more and 15% by mass or less, more preferably in the range of 1% by mass or more and 12% by mass or less, among the components constituting the toner particles. .

<Colorant>
The toner particles in this embodiment preferably contain a colorant. There is no restriction | limiting in particular as this coloring agent, A well-known coloring agent is mentioned, It selects according to the objective. As the colorant, a known organic or inorganic pigment or dye, or an oil-soluble dye can be used.

Examples of black pigments include carbon black and magnetic powder.
Examples of yellow pigments include Hansa Yellow, Hansa Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR, Slen Yellow, Quinoline Yellow, and Permanent Yellow NCG.
Red pigments include Bengala, Watch Young Red, Permanent Red 4R, Resol Red, Brilliantamine 3B, Brilliantamine 6B, Dupont Oil Red, Pyrazolone Red, Rhodamine B Lake, Lake Red C, Rose Bengal, Eoxin Red, Alizarin Lake Etc.
Blue pigments include bitumen, cobalt blue, alkali blue rake, Victoria blue rake, fast sky blue, induslen blue BC, aniline blue, ultramarine blue, calco oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite green oxare. Rate and so on. Moreover, these are mixed and used in the state of a solid solution.

  These pigments are dispersed by a known method. For example, a rotary-type homogenizer, a media type dispersing machine such as a ball mill, a sand mill, or an attritor, or a high-pressure counter-collision type dispersing machine is preferably used. In addition, these pigments are dispersed in an aqueous solvent using a homogenizer described above using a polar ionic surfactant to produce a colorant particle dispersion.

  When a pigment is used as the colorant of the toner according to the exemplary embodiment, one kind may be used alone, or two or more kinds of the same type of pigment may be mixed and used. Two or more different types of pigments may be mixed and used.

  Further, a dye may be used as a colorant for the toner according to the exemplary embodiment. For example, acridine, xanthene, azo, benzoquinone, azine, anthraquinone, dioxazine, thiazine, azomethine, indigo, thioindigo, phthalocyanine, aniline black, polymethine, triphenylmethane, Examples include various dyes such as diphenylmethane, thiazole, and xanthene. Moreover, a disperse dye, an oil-soluble dye, etc. are mentioned.

  One type of dye may be used alone, or two or more types of dyes of the same type may be mixed and used. Also, two or more different types of dyes may be mixed and used. Further, a dye and a pigment may be used in combination.

  In addition, when a monoazo pigment or a naphthol pigment is used as the colorant used for the toner particles in the present embodiment, the improvement in light resistance, which is an effect of the present invention, is particularly remarkable.

  The content of the colorant is preferably 1 part by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the binder resin. Of these, the larger one is preferred. Increasing the content of the colorant is advantageous in that the thickness of the image can be reduced when an image having the same density is obtained, which is effective in preventing offset.

(Method for producing toner particles)
Hereinafter, a method for producing toner particles will be described focusing on a method for producing toner particles having a core / shell structure.

  The toner particles in the exemplary embodiment are preferably manufactured by a wet manufacturing method in which the toner particles are manufactured in an acidic or alkaline aqueous medium. Examples of the wet production method include an aggregation coalescence method, a suspension polymerization method, a dissolution suspension granulation method, a dissolution suspension method, and a dissolution emulsion aggregation aggregation method.

  When the toner particles according to the exemplary embodiment are produced by the aggregation and coalescence method, a method including at least the following first aggregation step, the following second aggregation step, and the following fusion and coalescence step is given as an example.

(First aggregation step)
A resin particle dispersion in which first resin particles are dispersed, a colorant particle dispersion in which colorant particles are dispersed, and a release agent particle dispersion in which release agent particles are dispersed are mixed, and the first resin is mixed. Core agglomerated particles including particles, the colorant particles, and the release agent particles are formed.

(Second aggregation step)
A shell layer containing second resin particles is formed on the surface of the core aggregated particles to obtain core / shell aggregated particles.

(Fusion / unification process)
In the second agglomeration step, the core / shell agglomerated particles are heated to the glass transition temperature of the first resin particles or the second resin particles to be fused and united.

In the first aggregation step, first, a resin particle dispersion, a colorant particle dispersion, and a release agent particle dispersion are prepared.
The resin particle dispersion is prepared by dispersing the first resin particles prepared by emulsion polymerization or the like in a solvent using an ionic surfactant.
The colorant particle dispersion is obtained by using the ionic surfactant opposite to the ionic surfactant used in the preparation of the resin particle dispersion to obtain the colorant particles of a desired color such as black, blue, red, yellow, etc. Prepare by dispersing in solvent.
In addition, the release agent particle dispersion allows the release agent to be dispersed in water together with a polymer electrolyte such as an ionic surfactant, a polymer acid, or a polymer base, heated above the melting point, and subjected to strong shearing. It is prepared by granulating with a homogenizer or a pressure discharge type disperser.

  Next, the resin particle dispersion, the colorant particle dispersion, and the release agent particle dispersion are mixed, and the first resin particles, the colorant particles, and the release agent particles are hetero-aggregated so as to be close to a desired toner diameter. Aggregated particles (core aggregated particles) having a diameter and including first resin particles, colorant particles, and release agent particles are formed.

  In the second aggregating step, the second resin particles are adhered to the surface of the core agglomerated particles obtained in the first aggregating step by using a resin particle dispersion containing the second resin particles, and the desired thickness is obtained. By forming the coating layer (shell layer), aggregated particles (core / shell aggregated particles) having a core / shell structure in which a shell layer is formed on the surface of the core aggregated particles are obtained. In addition, the 2nd resin particle used in this case may be the same kind as the 1st resin particle, and may differ.

  The particle diameters of the first resin particles, the second resin particles, the colorant particles, and the release agent particles used in the first and second aggregating steps are adjusted to a desired value for the toner diameter and the particle size distribution. In order to facilitate this, it is preferably 1 μm or less, and more preferably in the range of 100 nm to 300 nm.

  The particle diameter of the resin particle dispersion thus obtained is measured, for example, with a laser diffraction particle size distribution measuring device (LA-700, manufactured by Horiba, Ltd.).

  In the first aggregation step, the balance of the amounts of the two polar ionic surfactants (dispersants) contained in the resin particle dispersion or the colorant particle dispersion may be shifted in advance. For example, an inorganic metal salt such as calcium nitrate or a polymer of an inorganic metal salt such as barium sulfate is ionically neutralized and heated below the glass transition temperature of the first resin particles to form core agglomerated particles. Is produced.

  In this case, in the second flocculation step, the resin particle dispersion treated with the polarity and amount of dispersant that compensates for the deviation in the balance between the two polar dispersants described above is placed in a solution containing core aggregated particles. Further, if necessary, the core / shell aggregated particles are produced by heating slightly below the glass transition temperature of the core aggregated particles or the second resin particles used in the second aggregation step as necessary. In addition, the 1st and 2nd aggregation process may be repeatedly performed in multiple steps stepwise.

Next, in the fusion / union process, the core / shell aggregated particles obtained through the second aggregation process are used as a first or second resin particle contained in the core / shell aggregated particles in a solution. The toner is obtained by heating to above the glass transition temperature (if the resin type is two or more, the glass transition temperature of the resin having the highest glass point transition temperature), fusing and coalescence.
After completion of the fusion / unification process, the toner formed in the solution is dried through a known washing process, solid-liquid separation process, and drying process to obtain a toner.

  In addition, it is preferable that the washing | cleaning process performs substitution washing | cleaning by ion-exchange water fully from a charging point. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, and the like are preferably used from the viewpoint of productivity. Further, although the drying process is not particularly limited, freeze drying, flash jet drying, fluidized drying, vibration fluidized drying and the like are preferably used from the viewpoint of productivity.

(Physical properties of toner particles)
The volume average particle size of the toner particles is preferably 3 μm or more and 9 μm or less, preferably 3.5 μm or more and 8.5 μm or less, and more preferably 4 μm or more and 8 μm or less.
As a method for measuring the volume average particle diameter of the toner particles, for example, a Coulter Multisizer-II type is used. Specific measurement methods will be described in Examples.

  Further, the shape factor SF1 of the toner particles is preferably 115 or more and 140 or less, preferably 118 or more and 138 or less, and more preferably 120 or more and 136 or less.

Here, the shape factor SF1 is obtained by the following equation (2).
SF1 = (ML ² / A) × (π / 4) × 100 (2)
In the above formula (2), ML represents the absolute maximum length of the toner particles, and A represents the projected area of the toner particles.

  The SF1 is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image using an image analyzer. Specific measurement methods will be described in Examples.

(External additive)
In the toner according to the exemplary embodiment, particles containing polytetrafluoroethylene are used as the external additive of the toner particles.
The polytetrafluoroethylene-containing particles are preferably composed of polytetrafluoroethylene. However, for a long period of time, the toner remaining on the latent image holding member without being transferred is maintained with good cleaning properties. Other components may be contained within a range that does not hinder the effect (for example, the content of other components in the particles is 10% by mass or less). Examples of the other components include hydrophobic treatment agents such as silicone oil.

  The primary particle size of the particles containing polytetrafluoroethylene is preferably 150 nm or more and 500 nm or less, more preferably 200 nm or more and 500 nm or less, and further preferably 250 nm or more and 500 nm or less. The primary particle diameter D50p of the particles containing polytetrafluoroethylene is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image using an image analyzer, for example, as follows. calculate. It is obtained by taking an optical microscope image of polytetrafluoroethylene dispersed on the surface of a slide glass into a Luzex image analyzer through a video camera, measuring the particle size of 100 toner particles, and determining the average value.

  Specific trade names for the polytetrafluoroethylene-containing particles include Lubron L2, Lubron L5, Lubron L5F (Daikin Industries), KTL-500F, KTL-8 (Kitamura), VIDAX AR. (Manufactured by DuPont) and Asahi Glass Co., Ltd. full-on brilliant L169 (manufactured by Asahi Glass Co., Ltd.) and the like, but are not limited thereto. Some of these exemplified products have a primary particle size of a single material larger than the range of 10 nm or more and 500 nm or less. It may be in the range of 500 nm or less.

  The content of the polytetrafluoroethylene-containing particles is preferably 0.1 parts by mass or more and 1.5 parts by mass or less, and 0.2 parts by mass or more and 0.8 parts by mass or less with respect to 100 parts by mass of the toner particles. More preferred. When the content of the polytetrafluoroethylene-containing particles exceeds 1.5 parts by mass, it may be difficult to firmly adhere the polytetrafluoroethylene to the toner, and the amount is less than 0.1 parts by mass. In some cases, good cleaning properties of the toner cannot be maintained.

(Metatitanic acid)
The toner according to the exemplary embodiment preferably includes particles containing metatitanic acid from the viewpoint of increasing strength against pressure change on the surface of the toner particles. When the strength against the change in pressure on the surface of the toner particles is increased, the toner is destroyed by the pressure when the surface of the latent image holding member is rubbed by a cleaning means such as a cleaning blade, and the polytetrafluoroethylene is liberated and the latent image holding member is released. Adhering to the surface of the film is suppressed.

  The content of the particles containing metatitanic acid is preferably 0.5 parts by mass or more and 2.0 parts by mass or less, and 0.7 parts by mass or more and 1.5 parts by mass or less with respect to 100 parts by mass of the toner particles. Is more preferable, and 0.9 mass part or more and 1.2 mass parts or less are still more preferable.

Metatitanic acid means a titanic acid hydrate TiO ₂ · nH ₂ O with n = 1.
In this embodiment, what was synthesize | combined by the sulfuric acid hydrolysis reaction as metatitanic acid may be used. The method for hydrophobizing metatitanic acid is not particularly limited, and the treatment is performed using a known hydrophobizing agent. Although there is no restriction | limiting in particular as a hydrophobization processing agent, For example, coupling agents, such as a silane coupling agent, a titanate coupling agent, or an aluminum coupling agent, or silicone oil etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.

Examples of the silane coupling agent include known ones. Examples of the silicone oil include dimethyl silicone oil, fluorine-modified silicone oil, and amino-modified silicone oil.
In the present embodiment, metatitanic acid hydrophobized with alkoxysilane is preferred from the viewpoint of treatment (high degree of hydrophobization).

  The particle size of the particles containing metatitanic acid is preferably 10 nm or more and 40 nm or less, more preferably 15 nm or more and 35 nm or less, and even more preferably 20 nm or more and 30 nm or less in that the relationship of the formula (1) is easily satisfied. . The particle diameter D50p of the particles containing metatitanic acid is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image using an image analyzer, and is calculated as follows, for example. It is obtained by taking an optical microscope image of metatitanic acid dispersed on the surface of a slide glass into a Luzex image analyzer through a video camera, measuring the particle size of 100 toner particles, and determining the average value.

In addition to the above components, various components such as an internal additive, a charge control agent, inorganic powder (inorganic particles), and organic particles may be added to the toner according to the exemplary embodiment as necessary.
Examples of the internal additive include metals such as ferrite, magnetite, reduced iron, cobalt, nickel, and manganese, alloys, and magnetic materials such as compounds containing these metals.

  The inorganic particles are added for various purposes, but may be added for adjusting the viscoelasticity of the toner. By adjusting the viscoelasticity, image glossiness and penetration into paper can be adjusted. As the inorganic particles, known inorganic particles such as silica particles, titanium oxide particles, alumina particles, cerium oxide particles, or particles obtained by hydrophobizing the surfaces thereof may be used alone or in combination of two or more. From the viewpoint of not impairing transparency such as color developability and OHP permeability, silica particles having a refractive index smaller than that of the binder resin are preferably used. Further, the silica particles may be subjected to various surface treatments, and for example, those subjected to surface treatment with a silane coupling agent, a titanium coupling agent, a silicone oil or the like are preferably used.

(Manufacture of toner)
A toner manufacturing method according to this embodiment will be described below.
The toner according to the exemplary embodiment is prepared by externally adding the polytetrafluoroethylene-containing particles to the toner particles prepared by the above-described method. In order to satisfy the relationship of the formula (1), The particles containing the polytetrafluoroethylene are controlled to a certain low temperature, and this and the toner particles are mixed and stirred at a high temperature. By stirring and mixing the particles containing the polytetrafluoroethylene and the toner particles at a high temperature, the temperature of the toner particles is the same as that of the particle toner containing the polytetrafluoroethylene in a soft state. It adheres firmly to the toner particles before. As a result, the relationship of the formula (1) is satisfied.

The temperature of the particles containing the polytetrafluoroethylene when the particles containing the polytetrafluoroethylene and the toner particles are mixed while stirring is preferably 10 ° C. or more lower than the mixing temperature with the toner particles, More preferably, the temperature is 15 ° C. or more lower, and further preferably 20 ° C. or more lower. On the other hand, if the temperature is 0 ° C. or lower, condensation may occur during mixing with the toner.
The temperature at which the polytetrafluoroethylene-containing particles and the toner particles are stirred and mixed varies depending on the type of the binder resin, but is generally preferably 20 ° C. or higher and 50 ° C. or lower. More preferably, the temperature is from 45 ° C. to 45 ° C., and further preferably from 25 ° C. to 35 ° C. Further, the time for stirring and mixing is preferably 3 minutes or longer and 30 minutes or shorter, more preferably 5 minutes or longer and 20 minutes or shorter, and further preferably 10 minutes or longer and 15 minutes or shorter.

  When the particles containing polytetrafluoroethylene and the toner particles are stirred and mixed, it is preferable that the particles containing metatitanic acid are also stirred and mixed together. By including the particles containing metatitanic acid, the strength against the pressure change of the surface of the toner particles is increased. However, the relationship of the above formula (1) can be easily obtained by stirring and mixing the particles containing metatitanic acid together. Is satisfied. It is considered that this is because the particles containing metatitanic acid press the particles containing polytetrafluoroethylene adhering to the toner particles when agitated against the toner particles. As a result, the effect of suppressing the unevenness of the halftone image becomes remarkable.

  The step of stirring and mixing is preferably performed using a stirring mixer such as a Henschel mixer or Nobilta.

<Electrophotographic developer>
The electrophotographic developer according to the exemplary embodiment includes at least the electrophotographic toner according to the exemplary embodiment.
The electrophotographic toner according to the exemplary embodiment is used as it is as a one-component developer or as a two-component developer. When used as a two-component developer, it is used by mixing with a carrier.

  The carrier that can be used in the two-component developer is not particularly limited, and a known carrier can be used. Examples thereof include magnetic metals such as iron oxide, nickel, and cobalt, magnetic oxides such as ferrite and magnetite, resin-coated carriers having a resin coating layer on the core surface, and magnetic dispersion carriers. Further, a resin-dispersed carrier in which a conductive material or the like is dispersed in a matrix resin may be used.

  In the carrier, the fluororesin that may be contained in the coating resin layer can be selected according to the purpose, but fluororesin such as polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene, etc. Examples of such resins are known per se. These may be used individually by 1 type and may use 2 or more types together.

In the carrier, it is preferable that at least resin particles and / or conductive particles are dispersed in the coating film coated with the coating resin. Here, the term “conductivity” refers to conductivity such that the volume resistivity measured based on JIS K 7194 “Resistivity Test Method by Conductive Plastic Four-Probe Method” is less than 10 ⁷ Ω · cm. When resin particles are dispersed in the coating film, they are evenly distributed in the thickness direction and the tangential direction of the carrier surface, so even if the coating film is worn out using the carrier, it is the same as when not in use. Surface formation is maintained and good charge imparting ability can be maintained for the toner. Further, when conductive particles are dispersed in the coating film, the conductive film is evenly dispersed in the thickness direction and the tangential direction of the carrier surface. However, the same surface formation as when not in use is maintained, and carrier deterioration is prevented. In addition, when the resin particle and electroconductive particle are disperse | distributed to a coating film, there exists the above-mentioned effect.

Examples of the resin particles include thermoplastic resin particles and thermosetting resin particles. Among these, thermosetting resins that can be relatively easily increased in hardness are preferable. From the viewpoint of imparting negative chargeability to the toner, resin particles made of nitrogen-containing resin containing nitrogen atoms are preferable. In addition, these resin particles may be used individually by 1 type, and may use 2 or more types together. The average particle diameter of the resin particles is, for example, preferably about 0.1 μm to 2 μm, and more preferably 0.2 μm to 1 μm. If the average particle diameter of the resin particles is less than 0.1 μm, the dispersibility of the resin particles in the coating film is poor. On the other hand, if the average particle diameter exceeds 2 μm, the resin particles easily fall off from the coating film, and the original effect is obtained. It may stop working. Conductive particles include metal particles such as gold, silver and copper; carbon black particles; semiconductive oxide particles such as titanium oxide and zinc oxide; titanium oxide, zinc oxide, barium sulfate, aluminum borate, potassium titanate And particles having the surface of powder or the like covered with tin oxide, carbon black, metal or the like. Here, semi-conductive means that the volume resistivity measured based on JIS K 7194 “Resistivity Test Method by Conductive Plastic Four-Probe Method” is 10 ⁷ Ω · cm or more and 10 ¹¹ Ω · cm or less. means.
These may be used alone or in combination of two or more. Among these, carbon black particles are preferable from the viewpoints of production stability, cost, conductivity, and the like. The type of carbon black is not particularly limited, but carbon black having a DBP oil absorption of about 50 ml / 100 g or more and 250 ml / 100 g or less is preferable because of excellent production stability.

  As a method for specifically coating the surface of the core material (carrier core material) with the coating resin in the carrier, a dipping method of immersing in the coating film forming liquid containing the coating resin, or the coating film forming liquid is used as the carrier core material And a kneader coater method in which the carrier core material is mixed with the coating film forming liquid in a state of being suspended by flowing air and the solvent is removed. Among these, the kneader coater method is preferable. The solvent used for the coating film forming liquid is not particularly limited as long as it dissolves only the coating resin, and can be selected from known solvents such as aromatics such as toluene and xylene. Group hydrocarbons; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran and dioxane; and the like.

  The mixing ratio (mass ratio) of the toner according to the exemplary embodiment and the carrier in the two-component developer is preferably in the range of toner: carrier = 1: 100 to 30: 100, and 3: 100 to 20: 100. A range of the degree is more preferable.

<Image forming apparatus>
Next, an image forming apparatus according to this embodiment using the electrophotographic toner according to this embodiment will be described.
The image forming apparatus according to the present embodiment includes a latent image holding member, a developing unit that develops an electrostatic latent image formed on the latent image holding member as a toner image with a developer, and a latent image holding member on the latent image holding member. Transfer means for transferring the formed toner image onto the transfer member, fixing means for fixing the toner image transferred onto the transfer member, and components remaining on the surface of the latent image holding member without being transferred. The electrophotographic developer according to this embodiment is used as the developer. Hereinafter, an example of the image forming apparatus according to the present embodiment will be described, but the present invention is not limited thereto. The main parts shown in the figure will be described, and the description of the other parts will be omitted.

  In this image forming apparatus, for example, the part including the developing unit may be a cartridge structure (process cartridge) that is detachable from the image forming apparatus, and the process cartridge includes at least a developer holder, The process cartridge according to this embodiment that contains the electrophotographic developer according to this embodiment is preferably used.

  FIG. 1 is a schematic configuration diagram illustrating a four-tandem color image forming apparatus which is an example of an image forming apparatus according to the present embodiment. 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 simply referred to as “units”) 10Y, 10M, 10C, and 10K are juxtaposed 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.

Above each of the units 10Y, 10M, 10C, and 10K, an intermediate transfer belt 20 as an intermediate transfer member is extended through each unit. The intermediate transfer belt 20 is provided by being wound around a driving roller 22 and a support roller 24 that are in contact with the inner surface of the intermediate transfer belt 20 that are spaced apart from each other from the left to the right in the drawing. It is designed to travel in the direction toward 10K. The support roller 24 is urged 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 the support roller 24. Further, an intermediate transfer member cleaning device 30 is provided on the side of the image carrier of the intermediate transfer belt 20 so as to face the driving 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 colors of toner 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 photosensitive member 1Y, a charging roller 2Y for charging the surface of the photosensitive member 1Y to a predetermined potential, and the charged surface is exposed by a laser beam 3Y based on a color-separated image signal to form an electrostatic latent image. An exposure device 3 to be formed, a developing device (developing means) 4Y for supplying the electrostatic latent image with charged toner and developing the electrostatic latent image, and a primary transfer roller for transferring the developed toner image onto the intermediate transfer belt 20 5Y (primary transfer unit) 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. 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, and 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 is reduced. On the other hand, it 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. At this development position, the electrostatic latent image on the photoreceptor 1Y is converted into a visible image (toner image) by the developing device 4Y.

  In the developing device 4Y, yellow toner according to the present embodiment 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 photoreceptor 1Y is conveyed to the primary transfer, a predetermined primary transfer bias is applied to the primary transfer roller 5Y, and the electrostatic force directed from the photoreceptor 1Y to 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 is 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 through the first to fourth units is arranged 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, a 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 provided. Is applied to the support roller 24. The transfer bias applied at this time is a (−) polarity that is 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 the present invention 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>
The process cartridge according to the present embodiment includes at least a developer holder, and stores the electrophotographic developer according to the present embodiment described above.
Further, the toner cartridge according to the present embodiment is attached to and detached from the image forming apparatus, and accommodates toner to be supplied to a developing unit provided in the image forming apparatus, and the toner according to the present embodiment described above. It is an electrophotographic toner.

FIG. 2 is a schematic configuration diagram showing a preferred example of a process cartridge containing the electrophotographic developer according to this embodiment. The process cartridge 200, together with the photosensitive member (latent image holding member) 107, a charging roller 108, a developing device (developing unit) 111, a photosensitive member cleaning device (cleaning unit) 113, an opening 118 for exposure, and static elimination exposure. The opening 117 is assembled and integrated using the mounting rail 116. In FIG. 2, reference numeral 300 represents a transfer object.
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). It forms a forming apparatus.

  The process cartridge shown in FIG. 2 includes a charging roller 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 combined selectively. In the processel cartridge according to the present embodiment, in addition to the photoconductor 107, the charging roller 108, the developing device 111, the photoconductor cleaning device (cleaning means) 113, the opening 118 for exposure, and the discharge exposure. You may provide at least 1 sort (s) selected from the group comprised from the opening part 117. FIG.

  Next, the toner cartridge according to this embodiment will be described. The toner cartridge according to the present exemplary embodiment is a toner cartridge that is attached to and detached from the image forming apparatus and stores at least toner to be supplied to a developing unit provided in the image forming apparatus. The toner according to the embodiment is used. Note that the toner cartridge according to the present embodiment only needs to contain at least toner, and may contain developer, for example, depending on the mechanism of the image forming apparatus.

  Therefore, in the image forming apparatus having a configuration in which the toner cartridge can be attached and detached, the toner according to the present embodiment can be easily supplied to the developing device by using the toner cartridge containing the toner according to the present embodiment.

  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 each developing devices (colors). And a toner supply pipe (not shown). Further, when the amount of toner stored in the toner cartridge is low, the toner cartridge can be replaced.

Hereinafter, although an Example and a comparative example are given and this embodiment is described in detail more concretely, this embodiment is not limited to these Examples at all. In addition, Examples 3-6, Example 10, Examples 12-15, Examples 21-22, Examples 25-27, and Examples 30-33 are reference examples.

<Production of toner>
-Synthesis of crystalline polyester resin-
In a heat-dried three-necked flask, put 49 mol% dimethyl sebacate, 1 mol% dimethyl isophthalate, 50 mol% ethylene glycol, and 0.2 parts by mass of dibutyltin oxide as a catalyst with respect to 100 parts by mass of the monomer component. After that, the inside of the container was brought into an inert atmosphere with nitrogen gas by depressurization, and stirred and refluxed at 180 ° C. for 5 hours with mechanical stirring.
Thereafter, the temperature was gradually raised to 230 ° C. under reduced pressure, and the mixture was stirred for 2 hours. When it became viscous, it was air-cooled, the reaction was stopped, and a crystalline polyester resin was synthesized. The weight average molecular weight (Mw) of the obtained crystalline polyester resin was 9700 by molecular weight measurement (polystyrene conversion) by gel permeation chromatography.

Next, using a crystalline polyester resin, a resin particle dispersion was prepared with the following composition.
-Crystalline polyester resin: 90 parts by mass-Ionic surfactant Neogen RK (Daiichi Kogyo Seiyaku): 1.8 parts by mass-Ion-exchanged water: 210 parts by mass After sufficiently dispersing with Ultra Turrax T50, dispersion treatment was performed with a pressure discharge type gorin homogenizer for 1 hour to obtain a crystalline resin particle dispersion having a center diameter of 200 nm and a solid content of 20% by mass.

-Synthesis of amorphous polyester resin-
・ Terephthalic acid: 15 mol%
・ Fumaric acid 35 mol%
-Bisphenol A ethylene oxide 2 mol adduct: 10 mol%
-Bisphenol A propylene oxide adduct: 40 mol%

The above monomer was charged into a 5 liter flask equipped with a stirrer, nitrogen inlet tube, temperature sensor, and rectifying column, and the temperature was raised to 190 ° C. over 1 hour. The reaction system was thoroughly stirred. After confirmation, 1.2 parts by mass of dibutyltin oxide was added to 100 parts by mass of the monomer component. While distilling off the generated water, the temperature was increased to 240 ° C. over 6 hours, and the dehydration condensation reaction was continued at 240 ° C. for another 3 hours. The acid value was 12.0 mg / KOH, and the weight average molecular weight was 12700. An amorphous polyester resin was obtained.
Subsequently, this was transferred in a molten state to Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) at a rate of 100 g / min.

Separately prepared aqueous medium tank is filled with 0.37 wt% diluted ammonia water diluted with ion-exchanged water with reagent-exchanged water, and heated at 120 ° C with a heat exchanger at a rate of 0.1 liter per minute. Then, it was transferred to Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) together with the melted amorphous polyester resin.
The Cavitron is operated under the conditions of a rotor rotation speed of 60 Hz and a pressure of 5 kg / cm ² to obtain an amorphous resin dispersion composed of an amorphous polyester resin having an average particle size of 0.16 μm and a solid content of 30% by mass. It was.

-Preparation of colorant dispersion-
-Cyan pigment (copper phthalocyanine B15: 3: manufactured by Dainichi Seika): 45 parts by mass-Ionic surfactant Neogen RK (Daiichi Kogyo Seiyaku): 5 parts by mass-Ion exchange water: 200 parts by mass And a homogenizer (IKA Ultra Tarrax) for 10 minutes to obtain a colorant dispersion having a central particle size of 168 nm and a solid content of 22.0% by mass.

-Preparation of release agent dispersion 1-
Polywax 655 (polyethylene wax, melting point 99 ° C .: manufactured by Baker Petrolite): 45 parts by mass Cationic surfactant Neogen RK (Daiichi Kogyo Seiyaku): 5 parts by mass ion-exchanged water: 200 parts by mass The liquid was heated to 95 ° C. and sufficiently dispersed with IKA Ultra Tarrax T50, and then dispersed with a pressure discharge type gorin homogenizer to obtain a release agent dispersion liquid 1.

-Preparation of release agent dispersion 2-
A release agent dispersion 2 was obtained in the same manner as the preparation of the release agent dispersion 1, except that the polyethylene wax was changed to polywax 655 (melting point 113 ° C .: manufactured by Baker Petrolite).

-Preparation of release agent dispersion 3-
A release agent dispersion 3 was obtained in the same manner as the preparation of the release agent dispersion 1, except that the polyethylene wax was changed to polywax 850 (melting point 107 ° C .: manufactured by Baker Petrolite).

-Preparation of release agent dispersion 4-
A release agent dispersion 4 was obtained in the same manner as the preparation of the release agent dispersion 1 except that the polyethylene wax was changed to polywax 500 (melting point 88 ° C .: manufactured by Baker Petrolite).

-Preparation of release agent dispersion 5-
A release agent dispersion 5 was obtained in the same manner as the preparation of the release agent dispersion 1 except that the polyethylene wax was changed to paraffin wax HNP9 (melting point 75 ° C .: manufactured by Nippon Seiki Co., Ltd.).
-Preparation of release agent dispersion 6-
A release agent dispersion 6 was obtained in the same manner as the preparation of the release agent dispersion 1 except that the ester wax was Riquemar B-100 (glycerin monobehenate, melting point 77 ° C .: manufactured by Riken Vitamin Co., Ltd.).

-Production of toner particles A-
Amorphous resin resin dispersion: 257.6 parts by mass Crystalline resin dispersion: 32.4 parts by weight Colorant dispersion: 27.3 parts by weight Release agent dispersion 1:35 parts by weight In a round stainless steel flask, Ultra-Turrax T50 was sufficiently mixed and dispersed. Subsequently, 0.20 part by mass of polyaluminum chloride was added thereto, and the dispersion operation was continued with an ultra turrax. The flask was heated to 48 ° C. with stirring in an oil bath for heating. After maintaining at 48 ° C. for 60 minutes, 70.0 parts by mass of the amorphous resin dispersion was gradually added thereto.

Thereafter, the pH of the system was adjusted to 9.0 with a 0.5 mol / l sodium hydroxide aqueous solution, and then the stainless steel flask was sealed and heated to 96 ° C. while continuing to stir using a magnetic seal for 5 hours. Retained.
After completion, the mixture was cooled, filtered, thoroughly washed with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed in 1 L of ion exchange water at 40 ° C., and stirred and washed at 300 rpm for 15 minutes. This was repeated five more times, and when the pH of the filtrate became 7.5 and the electric conductivity was 7.0 μS / cmt, solid-liquid separation was performed using No5A filter paper by Nutsche suction filtration. Next, vacuum drying was continued for 12 hours to produce toner particles A.
When the particle diameter of the toner particles A is measured, the volume average diameter D50 is 6.1 μm and the particle size distribution coefficient GSDv is 1.25. Moreover, it was observed that the shape factor of the particle | grains calculated | required from the shape observation by Luzex was 130. The content ratio of the crystalline resin and the amorphous resin in the toner particles A was 9:91.

-Production of toner particles B-
In the production of toner particles A, toner particles A were produced except that the amount of the amorphous resin resin dispersion used was changed to 281.3 parts by mass and the amount of the crystalline resin dispersion used was changed to 8.7 parts by mass. In the same manner, toner particles B were produced. When the particle diameter of the toner particles B was measured, the volume average diameter D50 was 6.0 μm and the particle size distribution coefficient GSDv was 1.20. Moreover, it was observed that the shape factor of the particle | grains calculated | required from the shape observation by Luzex was 135. The content ratio of the toner particle B crystalline resin and the amorphous resin was 3:97.

-Production of toner particles C-
Preparation of toner particles A, except that the amount of amorphous resin resin dispersion used was changed to 275.5 parts by mass and the amount of crystalline resin dispersion used was changed to 14.5 parts by weight. In the same manner, toner particles C were produced. When the particle diameter of the toner particles C was measured, the volume average diameter D50 was 6.0 μm, and the particle size distribution coefficient GSDv was 1.20. Moreover, it was observed that the shape factor of the particle | grains calculated | required from the shape observation by Luzex was 135. The content ratio of the crystalline resin and the amorphous resin in the toner particles C was 5:95.

-Production of toner particles D-
Preparation of toner particles A, except that the amount of amorphous resin resin dispersion used was changed to 272.6 parts by mass and the amount of crystalline resin dispersion used was changed to 17.4 parts by weight. In the same manner, toner particles D were produced. When the particle diameter of the toner particles D was measured, the volume average diameter D50 was 6.0 μm, and the particle size distribution coefficient GSDv was 1.20. Moreover, it was observed that the shape factor of the particle | grains calculated | required from the shape observation by Luzex was 135. The content ratio of the crystalline resin and the amorphous resin in the toner particles D was 6:94.

-Production of toner particles E-
In the production of toner particles A, toner particles A were produced except that the amount of amorphous resin tree dispersion used was changed to 266.8 parts by mass and the amount of crystalline resin dispersion used was changed to 23.2 parts by mass. In the same manner, toner particles E were produced. The particle diameter of the toner particles E was measured. The volume average diameter D50 was 6.0 μm and the particle size distribution coefficient GSDv was 1.24. Moreover, it was observed that the shape factor of the particle | grains calculated | required from the shape observation by Luzex was 132. The content ratio of the crystalline resin and the amorphous resin in the toner particles E was 8:92.

-Production of toner particles F-
In the production of toner particles A, the same procedure as in the production of toner particles A was performed, except that the amount of amorphous resin resin dispersion used was changed to 261 parts by mass and the amount of crystalline resin dispersion used was changed to 29 parts by mass. Toner particles F were prepared. When the particle diameter of the toner particles F was measured, the volume average diameter D50 was 6.1 μm, and the particle size distribution coefficient GSDv was 1.25. Moreover, it was observed that the shape factor of the particle | grains calculated | required from the shape observation by Luzex was 130. The content ratio of the crystalline resin and the amorphous resin in the toner particles F was 10:90.

-Production of toner particles G-
In the production of toner particles A, toner particles A were produced except that the amount of amorphous resin resin dispersion used was changed to 246.5 parts by mass and the amount of crystalline resin dispersion used was changed to 43.5 parts by mass. In the same manner, toner particles G were produced. When the particle diameter of the toner particles G was measured, the volume average diameter D50 was 6.3 μm and the particle size distribution coefficient GSDv was 1.27. Moreover, it was observed that the shape factor of the particle | grains calculated | required from the shape observation by Luzex was 128. The content ratio of the crystalline resin and the amorphous resin in the toner particles G was 15:85.

-Production of toner particles H-
In the production of toner particles A, the same procedure as in the production of toner particles A was performed, except that the amount of amorphous resin resin dispersion used was changed to 232 parts by mass and the amount of crystalline resin dispersion used was changed to 58 parts by mass. Toner particles H were produced. When the particle diameter of the toner particles H is measured, the volume average diameter D50 is 6.4 μm and the particle size distribution coefficient GSDv is 1.29. Moreover, it was observed that the shape factor of the particle | grains calculated | required from the shape observation by Luzex was 125. The content ratio of the crystalline resin and the amorphous resin in the toner particles H was 20:80.

-Production of toner particles J-
In the preparation of toner particles A, the toner particles A were prepared except that the amount of the amorphous resin resin dispersion was changed to 226.2 parts by mass and the amount of the crystalline resin dispersion was changed to 63.8 parts by mass. In the same manner, toner particles J were prepared. When the particle diameter of the toner particles J is measured, the volume average diameter D50 is 6.6 μm and the particle size distribution coefficient GSDv is 1.31. Moreover, it was observed that the shape factor of the particle | grains calculated | required from the shape observation by Luzex was 123. The content ratio of the crystalline resin and the amorphous resin in the toner particles J was 22:78.

-Production of toner particles K-
Toner particles K were prepared in the same manner as toner particles A except that the release agent dispersion 1 was changed to the release agent dispersion 3 in the preparation of toner particles A. When the particle diameter of the toner particles K is measured, the volume average diameter D50 is 6.0 μm, and the particle size distribution coefficient GSDv is 1.25. Moreover, it was observed that the shape factor of the particle | grains calculated | required from the shape observation by Luzex was 130.

-Production of toner particles L-
Toner particles L were prepared in the same manner as toner particles A except that the release agent dispersion 1 was changed to the release agent dispersion 2 in the preparation of toner particles A. When the particle diameter of the toner particles L was measured, the volume average diameter D50 was 6.0 μm, and the particle size distribution coefficient GSDv was 1.25. Moreover, it was observed that the shape factor of the particle | grains calculated | required from the shape observation by Luzex was 130.

-Production of toner particles M-
Toner particles M were prepared in the same manner as toner particles A except that the release agent dispersion 1 was changed to the release agent dispersion 4 in the preparation of toner particles A. When the particle diameter of the toner particles M was measured, the volume average diameter D50 was 6.0 μm, and the particle size distribution coefficient GSDv was 1.25. Moreover, it was observed that the shape factor of the particle | grains calculated | required from the shape observation by Luzex was 130.

-Production of toner particles N-
Toner particles N were prepared in the same manner as toner particles A except that the release agent dispersion 1 was changed to the release agent dispersion 5 in the preparation of toner particles A. When the particle diameter of the toner particles N was measured, the volume average diameter D50 was 6.0 μm, and the particle size distribution coefficient GSDv was 1.25. Moreover, it was observed that the shape factor of the particle | grains calculated | required from the shape observation by Luzex was 130.

-Production of toner particles P-
Toner particles P were prepared in the same manner as toner particles A, except that in the preparation of toner particles A, the release agent dispersion 1 was changed to the release agent dispersion 6. When the particle diameter of the toner particles P is measured, the volume average diameter D50 is 6.0 μm and the particle size distribution coefficient GSDv is 1.25. Moreover, it was observed that the shape factor of the particle | grains calculated | required from the shape observation by Luzex was 130.

-Production of metatitanic acid particles 1-
Using ilmenite as an ore, TiO (OH) ₂ was produced using a wet precipitation method in which iron powder was separated by dissolving in sulfuric acid and TiOSO ₄ was hydrolyzed to produce TiO (OH) ₂ .
Further, 100 parts by mass of the obtained TiO (OH) ₂ was dispersed in 1000 parts by mass of water, and 10 parts by mass of isobutyltrimethoxysilane was added dropwise thereto while stirring at room temperature (25 ° C.). Subsequently, this was filtered and water washing was repeated. And the metatitanic acid surface hydrophobized with isobutyltrimethoxysilane was dried at 150 degreeC, and the metatitanic acid particle 1 with a particle size of 20 nm was produced.

-Production of metatitanic acid particles 2-
Metatitanic acid particles 2 having a particle size of 10 nm were prepared in the same manner as in the production of metatitanic acid particles 1 except that the amount of isobutyltrimethoxysilane used was changed to 20 parts by mass in the production of metatitanic acid particles 1.

-Production of metatitanic acid particles 3-
Metatitanic acid particles 3 having a particle diameter of 40 nm were prepared in the same manner as in the preparation of metatitanic acid particles 1 except that the metatitanic acid particles 1 were changed to 5 parts by mass of isobutyltrimethoxysilane.

<Example 1>
(Preparation of Toner 1)
To 75 liter Henschel mixer adjusted to 25 ° C., 100 parts by mass of toner particles A and 0.4 parts by mass of Lubron L2 (made by Daikin Industries, polytetrafluoroethylene particles, 250 nm) whose temperature was adjusted at 5 ° C. for 24 hours. And stirred at a stirring speed of 17 m / s for 10 minutes. Thereafter, 1.0 part by mass of RY50 (manufactured by Nippon Aerosil Co., Ltd.) and 1.0 part by mass of metatitanic acid particles 1 were further added and maintained at 25 ° C., followed by stirring for 10 minutes at 22 m / s, and toner 1 Was made. For toner 1, “(A−B) / A × 100” was determined by the method described above. The results are shown in Table 1.

(Preparation of developer 1)
6 parts by mass of toner 1 and 96 parts by mass of carrier were added to a V-type blender and stirred for 5 minutes to prepare developer A. The carrier used was a ferrite carrier in which a resin film was formed from a crosslinked melamine resin containing carbon black on ferrite particles having a volume average particle diameter of 35 μm.

-Evaluation-
Using the produced developer 1, a maximum of 150,000 images were formed at an image density of 50% using DocuCenter-IIIC3300 (manufactured by Fuji Xerox Co., Ltd.). At that time, from the initial stage (before image formation), a halftone image consisting of fine lines having an angle of 45 degrees with respect to the developer process direction is created every 10,000 sheets, and the fine lines are disturbed (thickness and density of the lines). The halftone image (the presence or absence of unevenness) and the cleaning failure were confirmed, and the evaluation was stopped at the number of sheets in which any one occurred. Moreover, even if no problem occurred with 150,000 sheets, the evaluation was not continued further. The number of sheets is in a range where 10,000 sheets or more can be allowed. Table 1 shows the number of sheets in which evaluation was stopped due to occurrence of thin line disturbance, halftone image, or poor cleaning. If there is no problem with 150,000 sheets, “> 150,000” is described.

<Example 2>
Toner 2 was prepared in the same manner as Toner 1 except that Lubron L2 whose temperature was adjusted at 5 ° C. for 24 hours was changed to Lubron L2 whose temperature was adjusted to 10 ° C. for 24 hours. Further, a developer 2 was prepared in the same manner as in Example 1 except that the toner 2 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 3>
Toner 3 was prepared in the same manner as Toner 1 except that Lubron L2 whose temperature was adjusted at 5 ° C. for 24 hours was changed to Lubron L2 whose temperature was adjusted to 15 ° C. for 24 hours. Further, a developer 3 was produced in the same manner as in Example 1 except that the toner 3 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 4>
Toner 4 was prepared in the same manner as Toner 1 except that Lubron L2 whose temperature was adjusted at 5 ° C. for 24 hours was changed to Lubron L2 whose temperature was adjusted to 17 ° C. for 24 hours. Further, a developer 4 was prepared in the same manner as in Example 1 except that the toner 4 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 5>
Toner 1 was prepared in the same manner as toner 1 except that the adjustment temperature of the 75 liter Henschel mixer was changed from 25 ° C. to 20 ° C. Further, a developer 5 was produced in the same manner as in Example 1 except that the toner 5 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 6>
Toner 1 was prepared in the same manner as toner 1 except that the adjustment temperature of the 75 liter Henschel mixer was changed from 25 ° C. to 18 ° C. Further, a developer 6 was prepared in the same manner as in Example 1 except that the toner 6 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 7>
Toner 1 was prepared in the same manner as Toner 1 except that the adjustment temperature of the 75 liter Henschel mixer was changed from 25 ° C. to 35 ° C. Further, a developer 7 was prepared in the same manner as in Example 1 except that the toner 7 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 8>
Toner 1 was prepared in the same manner as toner 1 except that the adjustment temperature of the 75 liter Henschel mixer was changed from 25 ° C. to 45 ° C. Further, a developer 8 was prepared in the same manner as in Example 1 except that the toner 8 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 9>
Toner 1 was prepared in the same manner as toner 1 except that the adjustment temperature of the 75 liter Henschel mixer was changed from 25 ° C. to 50 ° C. Further, a developer 9 was prepared in the same manner as in Example 1 except that the toner 9 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 10>
(Production of Toner 10)
To 75 liter Henschel mixer adjusted to 25 ° C., 100 parts by mass of toner particles 1 and 0.4 parts by mass of Lubron L2 (manufactured by Daikin Industries, Ltd., polytetrafluoroethylene particles, 250 nm) adjusted to 5 ° C. for 24 hours. Then, 1.0 part by mass of RY50 (manufactured by Nippon Aerosil Co., Ltd.) and 1.0 part by mass of metatitanic acid particles 1 were added, and the mixture was stirred for 10 minutes at a stirring speed of 22 m / s while maintaining at 25 ° C. Thus, Toner 10 was produced. Further, a developer 10 was prepared in the same manner as in Example 1 except that the toner 10 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 11>
Toner 11 was prepared in the same manner as Toner 1 except that Lubron L2 was changed to Lubron L5 (Daikin Kogyo Co., Ltd., polytetrafluoroethylene particles, 180 nm). Further, a developer 11 was prepared in the same manner as in Example 1 except that the toner 11 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 12>
Toner 12 was prepared in the same manner as toner 1 except that Lubron L2 was changed to KTL-500F (manufactured by Kitamura Co., polytetrafluoroethylene particles, 500 nm). Further, a developer 12 was prepared in the same manner as in Example 1 except that the toner 12 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 13>
A toner 13 was produced in the same manner as in the production of the toner 1 except that the toner particles A were changed to the toner particles B in the production of the toner 1. Further, a developer 13 was produced in the same manner as in Example 1 except that the toner 13 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 14>
Toner 14 was prepared in the same manner as toner 1 except that toner particle A was changed to toner particle C in preparation of toner 1. Further, a developer 14 was produced in the same manner as in Example 1 except that the toner 14 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 15>
A toner 15 was produced in the same manner as in the production of the toner 1 except that the toner particles A were changed to the toner particles D in the production of the toner 1. Further, a developer 15 was prepared in the same manner as in Example 1 except that the toner 15 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 16>
Toner 16 was prepared in the same manner as toner 1 except that toner particle A was changed to toner particle E in preparation of toner 1. Further, a developer 16 was produced in the same manner as in Example 1 except that the toner 16 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 17>
A toner 17 was produced in the same manner as in the production of the toner 1 except that the toner particles A were changed to the toner particles F in the production of the toner 1. Further, a developer 17 was produced in the same manner as in Example 1 except that the toner 17 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 18>
A toner 18 was produced in the same manner as in the production of the toner 1 except that the toner particles A were changed to the toner particles G in the production of the toner 1. Further, a developer 18 was produced in the same manner as in Example 1 except that the toner 18 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 19>
A toner 19 was produced in the same manner as in the production of the toner 1 except that the toner particles A were changed to the toner particles H in the production of the toner 1. Further, a developer 19 was prepared in the same manner as in Example 1 except that the toner 19 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 20>
A toner 20 was produced in the same manner as in the production of the toner 1 except that the toner particles A were changed to the toner particles J in the production of the toner 1. Further, a developer 20 was produced in the same manner as in Example 1 except that the toner 20 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 21>
A toner 21 was produced in the same manner as in the production of the toner 1 except that the toner particles A were changed to the toner particles K in the production of the toner 1. Further, a developer 21 was produced in the same manner as in Example 1 except that the toner 21 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 22>
A toner 22 was produced in the same manner as in the production of the toner 1 except that the toner particles A were changed to the toner particles L in the production of the toner 1. Further, a developer 22 was produced in the same manner as in Example 1 except that the toner 22 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 23>
A toner 23 was produced in the same manner as in the production of the toner 1 except that the toner particles A were changed to the toner particles M in the production of the toner 1. Further, a developer 23 was produced in the same manner as in Example 1 except that the toner 23 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 24>
A toner 24 was produced in the same manner as in the production of the toner 1 except that the toner particles A were changed to the toner particles N in the production of the toner 1. Further, a developer 24 was produced in the same manner as in Example 1 except that the toner 24 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 25>
A toner 25 was produced in the same manner as in the production of the toner 1 except that the toner particles A were changed to the toner particles P in the production of the toner 1. Further, a developer 25 was prepared in the same manner as in Example 1 except that the toner 25 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 26>
A toner 26 was produced in the same manner as in the production of the toner 1 except that the amount of the metatitanic acid particles 1 was changed to 0.5 parts by mass in the production of the toner 1. Further, a developer 26 was produced in the same manner as in Example 1 except that the toner 26 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 27>
A toner 27 was produced in the same manner as in the production of the toner 1 except that the amount of the metatitanic acid particles 1 used in the production of the toner 1 was changed to 0.7 parts by mass. Further, a developer 27 was produced in the same manner as in Example 1 except that the toner 27 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 28>
A toner 28 was produced in the same manner as in the production of the toner 1 except that the amount of the metatitanic acid particles 1 used in the production of the toner 1 was changed to 0.9 parts by mass. Further, a developer 28 was produced in the same manner as in Example 1 except that the toner 28 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 29>
A toner 29 was produced in the same manner as in the production of the toner 1 except that the amount of the metatitanic acid particles 1 used in the production of the toner 1 was changed to 1.2 parts by mass. Further, a developer 29 was produced in the same manner as in Example 1 except that the toner 29 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 30>
A toner 30 was produced in the same manner as in the production of the toner 1 except that the amount of the metatitanic acid particles 1 used in the production of the toner 1 was changed to 1.5 parts by mass. Further, a developer 30 was produced in the same manner as in Example 1 except that the toner 30 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 31>
A toner 31 was prepared in the same manner as in the preparation of the toner 1 except that the amount of the metatitanic acid particles 1 used in the preparation of the toner 1 was changed to 1.8 parts by mass. Further, a developer 31 was prepared in the same manner as in Example 1 except that the toner 31 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 32>
A toner 32 was produced in the same manner as in the production of the toner 1 except that the metatitanic acid particles 1 were changed to the metatitanic acid particles 2 in the production of the toner 1. Further, a developer 32 was prepared in the same manner as in Example 1 except that the toner 32 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Example 33>
A toner 33 was produced in the same manner as in the production of the toner 1 except that the metatitanic acid particles 1 were changed to the metatitanic acid particles 3 in the production of the toner 1. Further, a developer 33 was produced in the same manner as in Example 1 except that the toner 33 was used in place of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Comparative Example 1>
Toner 34 was prepared in the same manner as toner 1 except that Lubron L2 whose temperature was adjusted to 5 ° C. for 24 hours was changed to Lubron L2 whose temperature was adjusted to 25 ° C. for 24 hours. Further, a developer 34 was produced in the same manner as in Example 1 except that the toner 34 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

<Comparative example 2>
(Production of Toner 35)
In a 75 liter Henschel mixer adjusted to 25 ° C., 100 parts by mass of toner particles 1 and 0.4 parts by mass of Lubron L2 (manufactured by Daikin Industries, Ltd., polytetrafluoroethylene particles, 250 nm) whose temperature was adjusted to 5 ° C. for 24 hours , RY50 (manufactured by Nippon Aerosil Co., Ltd.) 1.0 part by mass and 1.0 part by mass of metatitanic acid particles 1 were added and stirred at 13 m / s for 3 minutes while maintaining the temperature at 25 ° C. Produced. Further, a developer 35 was produced in the same manner as in Example 1 except that the toner 35 was used instead of the toner 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

  As shown in Table 1, the detected amount of polytetrafluoroethylene in the approximate toner measured with a fluorescent X-ray analyzer was dispersed in A, an aqueous medium, and ultrasonic vibration with an output of 60 W and a frequency of 20 kHz was applied for 1 hour. When the added amount of polytetrafluoroethylene measured with an X-ray fluorescence analyzer attached without being detached from the toner particles is B, the relationship of the above formula (1) is satisfied. In the toners produced in Examples 1 to 33, fine line disturbance (line thickness / density), halftone image (presence of unevenness), and occurrence of defective cleaning are suppressed.

1Y, 1M, 1C, 1K, 107 photoconductor (latent image holder)
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 cartridge 10Y, 10M, 10C, 10K Image forming 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 (5)

Toner particles containing at least a binder resin and a release agent, and particles containing polytetrafluoroethylene and particles containing metatitanic acid as external additives,
The amount of polytetrafluoroethylene adhering to the toner particles determined by fluorescent X-ray analysis is A, and the toner is dispersed in a 2% by weight aqueous surfactant solution. in after adding 1 hour vibration was determined by X-ray fluorescence analysis, when the detected amount of polytetrafluoroethylene adhered to the toner particles is B, meets a relation of the following formula (1),
The particles containing metatitanic acid have a content of 0.9 parts by mass to 1.2 parts by mass with respect to 100 parts by mass of the toner particles, and a particle size of 15 nm to 35 nm. An electrophotographic toner.
Formula (1)
(A−B) / A × 100 ≦ 5 [%] An electrophotographic developer comprising at least the electrophotographic toner according to claim 1 . A toner cartridge which is attached to and detached from an image forming apparatus and contains toner to be supplied to a developing unit provided in the image forming apparatus, wherein the toner is the electrophotographic toner according to claim 1. . A process cartridge comprising at least a developer holder and containing the electrophotographic developer according to claim 2 . A latent image holder, developing means for developing the electrostatic latent image formed on the latent image holder with the electrophotographic developer according to claim 2 to form a toner image, and the latent image holder A transfer unit that transfers the toner image formed on the transfer member; a fixing unit that fixes the toner image transferred onto the transfer member; and the toner image remaining on the surface of the latent image holding member without being transferred. An image forming apparatus comprising: a cleaning unit that cleans components.

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