JP6442948B2 - Electrostatic image developing toner, electrostatic image developer, toner cartridge, developer cartridge, process cartridge, image forming apparatus, and image forming method - Google Patents

Description

  The present invention relates to an electrostatic charge image developing toner, an electrostatic charge image developer, a toner cartridge, a developer cartridge, a process cartridge, an image forming apparatus, and an image forming method.

A method of visualizing image information through an electrostatic charge image such as electrophotography is currently used in various fields. In electrophotography, an electrostatic charge image (electrostatic latent image) is formed on a photoreceptor (image carrier) by charging and exposure processes, the electrostatic latent image is developed with a developer containing toner, and a transfer and fixing process. It is visualized through.
In recent years, there is an increasing demand for forming an image on a recording medium different from conventional recording paper, such as printing on cardboard.
As conventional electrostatic charge image developing toners, those described in Patent Documents 1 and 2 are known.

JP 2004-226726 A JP 2006-235615 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a toner for developing an electrostatic charge image, in which the occurrence of toner scattering is suppressed even when an image is output at a low speed in a low temperature environment, and which has excellent storage stability.

The above-mentioned problems of the present invention have been solved by means described in the following <1> and <5> to <10>. It is described below together with <2> to <4> which are preferred embodiments.
<1> In the dynamic viscoelastic rheometer viscoelasticity measurement, a temperature T1 where tan δ has a maximum value is in a range of 50 ° C. or higher and 90 ° C. or lower, tan δ at T1 is 2.5 or higher and 3 or lower, and differential scanning calorific value In a DSC curve measured by a meter, a plurality of local maximum points are shown when the temperature is lowered, at least one of the local maximum points is present in a lower temperature region than T1, and at least one of the local maximum points is in a region higher than T1. A toner for developing electrostatic images, characterized in that
<2> The electrostatic charge image developing toner according to <1>, which contains a binder resin and a release agent, and the release agent exposed on the toner surface is 40% by area or less.
<3> The electrostatic charge image developing toner according to <2>, wherein the binder resin contains a styrene-acrylic resin,
<4> The electrostatic image developing toner according to any one of <1> to <3>, which contains two or more release agents having different melting temperatures.
<5> The electrostatic charge image developing toner according to any one of <1> to <4>, and an electrostatic charge image developer containing a carrier,
<6> A toner cartridge that is detachable from the image forming apparatus and contains the electrostatic charge image developing toner according to any one of <1> to <4>.
<7> A developer cartridge containing the electrostatic charge image developer according to <5>.
<8> A process cartridge comprising a developer holding body that contains the electrostatic image developer according to <5> and holds and conveys the electrostatic image developer.
<9> Image carrier, charging unit for charging the image carrier, exposure unit for exposing the charged image carrier to form an electrostatic latent image on the surface of the image carrier, and development including toner Developing means for developing the electrostatic latent image with an agent to form a toner image, transfer means for transferring the toner image from the image holding member to the surface of the transfer target, and toner transferred to the surface of the transfer target Fixing means for fixing an image, and the developer is the electrostatic image developing toner according to any one of <1> to <4>, or the electrostatic image development according to <5>. An image forming apparatus which is an agent,
<10> A latent image forming step for forming an electrostatic latent image on the surface of the image carrier, and development for forming the toner image by developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner. And a fixing step for fixing the toner image transferred to the surface of the transfer medium, wherein <1> to <4> are used as the developer. An image forming method using the electrostatic image developing toner according to any one of the above or the electrostatic image developer according to <5>.

According to the invention described in the above <1>, compared to the case where the present configuration is not provided, the occurrence of toner scattering is suppressed even when an image is output at a low speed, and the electrostatic charge is excellent in storage stability. An image developing toner is provided.
According to the invention described in the above <2>, the occurrence of toner scattering is further suppressed and the storage stability is improved as compared with the case where the release agent exposed on the toner surface exceeds 40 area%. An excellent toner for developing an electrostatic image is provided.
According to the invention described in <3>, an electrostatic charge image in which the occurrence of toner scattering is further suppressed and the storage stability is excellent as compared with the case where the binder resin is not a styrene-acrylic resin. A developing toner is provided.
According to the invention described in <4>, the occurrence of toner scattering can be more easily suppressed and storage stability can be more easily suppressed than when two or more release agents having different melting temperatures are not contained. An excellent toner for developing an electrostatic image is provided.
According to the invention described in the above <5>, compared to the case where the present configuration is not provided, the occurrence of toner scattering is suppressed even when an image is output at a low speed, and the electrostatic charge is excellent in storage stability. An image developer is provided.
According to the invention described in <6> above, compared to the case where the present configuration is not provided, the occurrence of toner scattering is suppressed even when an image is output at a low speed, and the electrostatic charge is excellent in storage stability. A toner cartridge containing image developing toner is provided.
According to the invention described in <7>, compared to the case where this configuration is not provided, the occurrence of toner scattering is suppressed even during image output at low speed, and the electrostatic charge has excellent storage stability. A developer cartridge containing an image developer is provided.
According to the invention described in <8>, an electrostatic charge that is less likely to scatter toner even when outputting an image at a low speed and has excellent storage stability, as compared with the case without this configuration. A process cartridge containing an image developer is provided.
According to the invention described in <9>, the occurrence of toner scattering can be suppressed even when an image is output at a low speed, and the storage stability of the toner is excellent as compared with the case where the present configuration is not provided. An image forming apparatus is provided.
According to the invention described in <10>, the occurrence of toner scattering is suppressed even when an image is output at low speed, and the storage stability of the toner is excellent as compared with the case where the present configuration is not provided. An image forming method is provided.

Hereinafter, the present embodiment will be described.
In the present embodiment, the description “A to B” represents not only a range between A and B but also a range including A and B at both ends thereof. For example, if “A to B” is a numerical value range, “A or more and B or less” or “B or more and A or less” is represented.

(Static image developing toner)
The toner for developing an electrostatic charge image of this embodiment has a temperature T1 at which tan δ has a maximum value in a range of 50 ° C. or higher and 90 ° C. or lower in dynamic viscoelastic rheometer viscoelasticity measurement, and tan δ at T1 is 2.5. In the DSC curve measured by a differential scanning calorimeter, which is 3 or less, a plurality of local maximum points are shown when the temperature is lowered, and at least one of the local maximum points is present in a lower temperature region than T1, At least one is present in a higher temperature region than T1.

When printing on thick paper or the like, the print strength is likely to decrease, so the output speed may be lowered. The present inventors have found that toner scattering occurs during image output at such a low speed. Such toner splattering was particularly remarkable in a low temperature environment.
The electrostatic image developing toner is charged inside the developing machine and developed by an electrostatic latent image formed on the image carrier, and the developed image of the toner is transferred to a recording medium by electric force, and an unfixed toner image Is obtained. The unfixed toner image is heated and pressurized by a fixing member to melt and fix the toner particles on the recording medium, thereby obtaining an output image.
When outputting to thick paper as a recording medium, the energy of heat and pressure required to melt and fix the toner particles on the recording medium increases, so that the unfixed toner image is not sufficiently melted and fixed on the recording medium. When the strength of the fixed image is reduced and the output image is overlaid or rubbed with a hand or an elbow, a part of the toner is peeled off from the recording medium, causing image loss or contamination. By lowering the image formation speed and increasing the time to pressurize and heat the unfixed toner image, sufficient heat and pressure energy can be given to the unfixed image. Sufficient image intensity can be obtained.
However, at this time, the present inventors have found that toner stains may occur despite the sufficient image intensity, and it is difficult to stably obtain a high-quality image. The toner contamination not depending on the image intensity is particularly remarkable when an image having a high density is formed or when an image is formed in a low humidity environment such as a room heated in winter.
A heating and pressing member (hereinafter referred to as a heating and pressing member) of the fixing device contacts the recording medium at the time of fixing, and after applying heat and pressure to the unfixed toner image and the recording medium, the heating and pressing member leaves the recording medium. The recording medium is often paper or plastic film coated with an inorganic material such as calcium carbonate. When the recording medium is separated from the heating and pressing member after being heated and pressurized by the heating and pressing member, The peeling discharge occurs and static electricity accumulates on the surface of the recording medium.
Further, immediately before the unfixed toner image is melted and pressed by the fixing device, the unfixed toner image is in a state of being close to the heating and pressing member of the fixing device. When the heat and pressure member in which static electricity is accumulated approaches the unfixed toner image, the unfixed toner image is affected by the static electric field of the heat and pressure member, and the chargeability of the toner and the heat and pressure member are charged with the same charge. In some cases, it was estimated that the toner of the unfixed image repels the electric field of the heating and pressing member and scatters to cause toner smearing around the image. In addition, when the chargeability of the toner and the charge of the heat and pressure member are different charges, a part of the toner of the unfixed toner image is transferred to the heat and pressure member before the unfixed toner image contacts the heat and pressure member. Then, it has been estimated that the toner transferred to the heating and pressing member re-transfers to the recording medium side when it comes into contact with the recording medium and causes offset-like stains.
When the image output speed is slow, such as when forming an image on cardboard, the time during which the unfixed toner image is affected by the electric field of the heating and pressurizing member becomes longer, so toner scattering and offset stains are likely to occur. When the humidity is low, such as in winter, static electricity tends to accumulate on the pressure heating member, so that it was estimated that toner scattering and offset contamination become more prominent. In a solid image with a high image density, the number of unfixed toner particles present in the image area increases, so the amount of static electricity held by the entire unfixed toner image increases and is strongly affected by the electric field of a statically heated and pressurized member. For this reason, it is estimated that toner scattering and offset contamination become more prominent.
As a result of intensive studies, the inventors of the present invention have a maximum value of tan δ in a specific temperature range, the maximum value is in a specific range, and further, a DSC curve in a high temperature region and a low temperature region of the maximum value of tan δ. It has been found that the occurrence of such toner scattering and offset-like stains can be remarkably suppressed by having the maximum point.

<Temperature value of tan δ and temperature T1 at which tan δ exhibits a maximum value>
The toner for developing an electrostatic charge image of the present embodiment has a temperature T1 at which tan δ has a maximum value at 50 ° C. or more and 90 ° C. or less in dynamic viscoelastic rheometer viscoelasticity measurement, and tan δ at T1 (hereinafter also referred to as tan δ _1). Is 2.5 or more and 3 or less.
The heating and pressing member is already heated at the start of the fixing operation, and radiant heat is generated from the heating and pressing member. Accordingly, the unfixed toner image is heated by the radiant heat generated from the heating and pressing member before contacting the heating and pressing member. An unfixed toner before contact with the heating and pressing member has a temperature T1 where tan δ exhibits a maximum value in the range of 50 ° C. to 90 ° C. and tan δ (tan δ ₁ ) at T1 is 2.5 to 3. Exhibits an appropriate viscosity, so that the adhesion between the toner particles or between the toner and the recording medium is moderately exerted. It is thought that dirt can be suppressed.
When T1 is less than 50 ° C., toner storage stability is poor and toner aggregation may occur in the image forming apparatus. On the other hand, if the temperature exceeds 90 ° C., the toner particles immediately before coming into contact with the heating and pressing member cannot exhibit adhesiveness, and it is difficult to suppress the occurrence of toner scattering and offset contamination. Further, when tan δ ₁ is less than 2.5, the adhesiveness of the toner particles immediately before coming into contact with the heating and pressing member is low, and it is difficult to suppress the occurrence of toner scattering and offset contamination. On the other hand, if it exceeds 3, the toner particles will become too sticky, so that when they come into contact with the heating and pressing member, the toner particles are excessively adhered to the surface of the heating and pressing member, and a part of the toner in the image is formed. It may melt excessively and shift to a heating and pressing member, which may cause offset dirt.
The temperature T1 at which tan δ exhibits a maximum value is preferably 55 to 85 ° C, and more preferably 60 to 80 ° C.
The tan δ ₁ is preferably 2.6 to 3.0, more preferably 2.6 to 2.9.

In this embodiment, tan δ ₁ of the toner is obtained by dynamic viscoelastic rheometer viscoelasticity measurement. Specifically, it is measured by the following method.
Using a rotating plate rheometer (Rheometrics, rotating plate Leonometer ARES), using a parallel plate with a diameter of 8 mm and a frequency of 1 rad / sec, applied strain initial value 0.01%, maximum strain 20%, maximum torque Automatic strain adjustment is performed in the range of 100 and the minimum torque of 10, and the temperature rise measurement is performed between 30 ° C. and 150 ° C. at a rate of temperature rise of 1 ° C./min and a sample weight of about 0.3 g.

The electrostatic image developing toner of the present embodiment preferably has a _second maximum value of tan δ (also referred to as tan δ ₂ ) at 90 ° C. to 140 ° C. The second maximum value is more preferably in the range of 95 ° C to 140 ° C, and still more preferably in the range of 100 ° C to 140 ° C.
tan δ ₂ is preferably 1.2 to 2.0, more preferably 1.2 to 1.8, and still more preferably 1.4 to 1.8.
By having the second maximum value within the above range, the unfixed toner image enters the contact portion (hereinafter also referred to as a fixing nip portion) between the heating and pressing member and the recording medium, and the toner particles in the fixing nip portion. When the material is melted and fixed on the recording medium, proper melt viscoelasticity can be exhibited in order to normally fix it on the recording medium. If tan δ ₂ is too large, the viscosity will be too low and the cohesive force between the toner particles will decrease, and some of the melted toner particles will move to the surface of the heating and pressing member and will re-transfer to another part of the recording medium. A so-called hot offset phenomenon is likely to occur, which causes image contamination and heat-pressing member contamination. If tan δ ₂ is too small, the toner particles are difficult to be fixed to the recording medium, so that part of the image is easily lost when the image portion on the recording medium is folded or rubbed.
The measurement method of tan δ ₂ can be performed in the same manner as the measurement of tan δ ₁ .

<Maximum point when DSC falls>
The toner for developing an electrostatic charge image of this embodiment shows a plurality of maximum points when the temperature is lowered in a DSC curve measured by a differential scanning calorimeter, and at least one of the maximum points exists in a lower temperature region than T1. , At least one of the local maximum points exists in a higher temperature region than T1.
Since the temperature lowering peak is above and below the temperature T1, a part of the release agent is softened at a temperature lower than T1, so that when the toner particles start to contact the heating and pressing member, a part of the release agent is formed on the toner surface. It is presumed that bleeding between the toner and the heating and pressing member is likely to occur, and excessive adhesion between the toner and the surface of the heating and pressing member is suppressed. Further, since a part of the release agent softens at a temperature higher than T1, the release agent oozes out from the toner during the heating and pressurization, thereby improving the peelability between the toner image and the heating and pressing member. Therefore, it is estimated that offset-like dirt can be further suppressed.

In this embodiment, the maximum point in the DSC curve measured by the differential scanning calorimeter is measured as follows.
It is measured using DSC-50 (manufactured by Shimadzu Corporation) as a differential scanning calorimeter. Specifically, 9 mg of toner is put in an aluminum sample container, and the sample container is placed on a holder unit and set in an electric furnace. Next, after holding at 10 ° C. for 10 minutes in a nitrogen atmosphere, the temperature was raised from 10 ° C. to 200 ° C. at 10 ° C./min, then maintained at 200 ° C. for 5 minutes, and then from 200 ° C. to 10 ° C. The temperature is lowered to 30 ° C./min.

The temperature at which the DSC curve presents a maximum point in a region higher than T1 is preferably T1 + 3 to T1 + 70 ° C., and more preferably T1 + 3 to T1 + 50 ° C. There may be a plurality of temperatures at which the DSC curve has a maximum point in the higher temperature region than T1, but the DSC curve in the higher temperature region than T1 has the largest amount of heat among the maximum points. Point to.
The temperature at which the DSC curve presents the maximum point in the lower temperature region than T1 is preferably T1-5 to T1-40 ° C, and more preferably T1-10 to T1-30 ° C.

  The difference between the temperature at which the DSC curve presents in the higher temperature region than T1 and the temperature at which the DSC curve present in the lower temperature region than T1 exhibits the maximum value is preferably 5 to 40 ° C. More preferably, it is 5-30 degreeC, and it is still more preferable that it is 5-20 degreeC. When the temperature difference is within the above range, a toner for developing a positively charged image having excellent storage stability is obtained while suppressing image disturbance such as toner scattering and contamination due to hot offset at a wider range of fixing speeds and fixing temperatures. be able to.

Hereinafter, each component used for the electrostatic image developing toner of the present embodiment and a manufacturing method thereof will be described in detail.
The toner for developing an electrostatic charge image according to the exemplary embodiment is preferably a toner in which an external additive is externally added to toner particles (also referred to as toner base particles), and the toner base particles include at least a binder resin and a release agent. It is preferable to contain a colorant and other components such as a colorant as necessary.

<Binder resin>
The binder resin (hereinafter also simply referred to as resin) or binder resin particles (hereinafter also referred to as resin fine particles) used in the present invention is not particularly limited, but is generally an ionic surfactant by an emulsion polymerization method or the like. A resin fine particle dispersion containing is prepared and used. Alternatively, a resin fine particle dispersion obtained by phase inversion emulsification in phase with an aqueous medium after dissolving in a solvent or a self emulsification method using resin polarity or additives may be used.

There are no particular limitations on the polymers that can be used as the resin or resin fine particles used in the present invention, but homopolymers or copolymers of ethylenically unsaturated monomers including vinyl monomers can be preferably used. Examples of monomers constituting these homopolymers or copolymers include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, acrylic (Meth) acrylic acid esters such as n-butyl acid, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; acrylonitrile, Ethylenically unsaturated nitriles such as methacrylonitrile; Ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; Vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; Vinyl methyl ketone, vinyl ethyl ketone and vinyl iso Vinyl ketones such as Ropeniruketon, ethylene, propylene, and the like olefins such as butadiene, beta-carboxyethyl acrylate can be exemplified. A homopolymer composed of these monomers, a copolymer obtained by copolymerizing two or more of these monomers, and a mixture thereof can be used.
In addition, epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and the like, non-vinyl condensation resins, or a mixture of these with the ethylenically unsaturated addition polymer resin, And graft polymers obtained by polymerizing ethylenically unsaturated monomers.

  As the polymerization initiator, any suitable polymerization initiator such as 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis is used. (Cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azo or diazo polymerization initiators such as azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide And peroxide polymerization initiators such as diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, thiols such as dodecanethiol, ammonium peroxodisulfate, and the like.

On the other hand, it is also preferable to use a polyester resin in the toner of the present invention. The polyester resin 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. The polyester resin used for emulsification dispersion is synthesized from a polyvalent carboxylic acid and a polyhydric alcohol.
Examples of polycarboxylic acids include terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, naphthalenedicarboxylic acid, and other aromatic carboxylic acids, maleic anhydride, fumaric acid, succinic acid, alkenyl Examples thereof include aliphatic carboxylic acids such as succinic anhydride and adipic acid, and alicyclic carboxylic acids such as cyclohexanedicarboxylic acid. These polyvalent carboxylic acids can be used alone or in combination. Of these polyvalent carboxylic acids, it is preferable to use aromatic carboxylic acids, and in order to take a crosslinked structure or a branched structure in order to ensure good fixability, tricarboxylic or higher carboxylic acids (trimerits) It is preferable to use an acid or an acid anhydride thereof in combination.
Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, glycerin, and other aliphatic diols, cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A And aromatic diols such as bisphenol A ethylene oxide adduct and bisphenol A propylene oxide adduct. One or more of these polyhydric alcohols can be used. Among these polyhydric alcohols, aromatic diols and alicyclic diols are preferable, and among these, aromatic diols are more preferable. In order to secure good fixing properties, a trihydric or higher polyhydric alcohol (glycerin, trimethylolpropane, pentaerythritol, etc.) may be used in combination with the diol in order to obtain 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 and the like, and examples of the monoalcohol include methanol, ethanol, propanol, octanol, 2-ethylhexanol, and trifluoroethanol. , Trichloroethanol, hexafluoroisopropanol, phenol and the like.

The polyester resin can be produced by subjecting the polyhydric alcohol and polyhydric carboxylic acid to a condensation reaction according to a conventional method. For example, the polyhydric alcohol and polyhydric carboxylic acid, if necessary, a catalyst is added, 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 to 250 ° C. to continuously remove by-product low-molecular compounds out of the reaction system, stop the reaction when a predetermined acid value is reached, cool, and obtain the desired reactant Can be manufactured.
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. The amount of such a catalyst added is preferably 0.01 to 1% by weight based on the total amount of raw materials.

The glass transition temperature (glass transition point) of the binder resin used in the present invention is preferably 50 to 70 ° C, and more preferably 55 to 65 ° C. A glass transition temperature within the above range is preferable because it is suitable for low-temperature fixing.
The weight average molecular weight Mw of the binder resin used in the present invention is preferably 5,000 to 50,000, and particularly a homopolymer or copolymer of an ethylenically unsaturated monomer containing a vinyl monomer. In the case of a coalescence (vinyl resin), it is more preferably 8,000 to 40,000, and in the case of a polyester resin, it is more preferably 8,000 to 30,000.

When an ethylenically unsaturated monomer is polymerized, a resin fine particle dispersion can be prepared by carrying out emulsion polymerization using an ionic surfactant or the like. In addition, in the case of other resins, if the resin is soluble in a solvent that is oily and has a relatively low solubility in water, the resin is dissolved in those solvents, and a homogenizer together with an ionic surfactant or polymer electrolyte in water. The resin fine particle dispersion can be prepared by dispersing as fine particles in water using a disperser and then evaporating the solvent by heating or decompressing. The particle size of the resin fine particles in these dispersions can be measured, for example, with a laser diffraction particle size distribution analyzer LA-700 (manufactured by Horiba, Ltd.).
The particle size of the resin fine particles in the dispersion is preferably 100 to 300 nm, and more preferably 150 to 250 nm. It is preferable that the particle size is in the above range since the particle size distribution of the obtained toner is narrow, free particles are not generated, and the performance and reliability of the toner are improved.

  In this embodiment, the binder resin is preferably a homopolymer or copolymer of an ethylenically unsaturated monomer, styrenes such as styrene, parachlorostyrene, α-methylstyrene, and (meth) acrylic acid. And / or methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, methacryl A copolymer with (meth) acrylic acid esters such as lauryl acid and 2-ethylhexyl methacrylate is more preferred. Copolymers of styrenes with (meth) acrylic acid and / or (meth) acrylic acid esters (hereinafter also referred to as styrene-acrylic resins) are addition polymerization, so the ratio of monomer to initiator and chain It is easy to control the molecular weight by introducing a transfer agent, a cross-linking agent, etc., and furthermore, it is easy to control the glass transition temperature and charging characteristics depending on the ratio of styrene monomer and acrylic monomer and the type of acrylic monomer. Excellent as a binder resin. Also in the present invention, a styrene-acrylic resin is particularly preferable because tan δ1, T1 and the like can be controlled while maintaining an appropriate glass transition temperature and charging characteristics important as a binder resin for the toner.

When using a styrene-acrylic resin as the binder resin, prepare multiple resins with different average molecular weights and glass transition temperatures, and mix them when preparing the toner particles to control the characteristics during melting to make tanδ and T suitable. Can be. When using styrene-acrylic resins having different molecular weights, a resin is prepared by emulsion polymerization, and when emulsion particles are aggregated and united to obtain toner particles, a plurality of resin particles having different molecular weights are mixed during aggregation. To achieve. When the toner particles are added at the time of aggregation, the properties at the time of melting the toner particles can be controlled by adding resin particles having different molecular weights during the aggregation process or changing the ratio.
In addition, since a high molecular weight component can be introduced by polymerizing by mixing a trace amount of a polyfunctional monomer, for example, a cross-linking agent having a plurality of vinyl groups, to optimize the characteristics at the time of melting. Can do.
More specifically, by mixing a resin having a high glass transition temperature or a resin containing a crosslinking component with a resin having a low glass transition temperature, the temperature T1 at which tan δ exhibits a maximum value tends to decrease. By reducing the weight average molecular weight of the resin having a high glass transition temperature or a crosslinking component, tan δ can be set to 2.5 or more and 3 or less.
Adjustment is also possible by preparing a plurality of release agents at the same time and using a release agent compatible with a part of the resin.
Styrene-acrylic resin can be obtained by solution polymerization, suspension polymerization, or emulsion polymerization, and toner particles can be obtained by kneading and pulverization using the obtained resin. The emulsion aggregation method or emulsion polymerization aggregation method is particularly suitable because of its high controllability.

Further, the use of styrene-acrylic resin as the binder resin can be detected, for example, by the following method.
About 20 mg of toner particles are weighed in a sample bottle, and 1 ml of deuterated chloroform as a solvent is added and dissolved sufficiently. The solution is transferred to an NMR sample tube (φ5 mm) and subjected to NMR spectrum measurement.
Measuring device JNM-AL400 FT-NMR manufactured by JEOL Ltd.
Measurement condition:
Sample container: Φ5mm NMR sample tube Solvent: Deuterated chloroform solution Sample temperature: 20 ° C
Observation nucleus: ¹ H
Integration count: 128 times Standard: TMS
Spectral analysis of the measurement result is performed, and the vinyl integrated resin is contained in the toner particles by detecting the peak integral value due to the methylene component adjacent to the acryloyloxy group of 5.0 to 3.2 ppm. Can be confirmed.

<Release agent>
Examples of mold release agents include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax, and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; ester types such as fatty acid esters and montanic acid esters Wax; and the like. The release agent is not limited to this. In particular, hydrocarbon waxes are suitable for fixing because they are excellent in fixing.

In this embodiment, it is preferable to contain two or more release agents having different melting temperatures as the release agent. By containing two or more release agents having different melting temperatures, when the toner changes its temperature by receiving thermal energy during fixing, the exudation of the release agent is appropriately promoted over a wide temperature range. Offset-like dirt can be suppressed more effectively.
It is preferable that at least one of the two or more release agents having different melting temperatures has a melting temperature in a region lower than T1 and at least one has a melting temperature in a region higher than T1. Accordingly, the DSC curve measured by the differential scanning calorimeter has a plurality of local maximum points when the temperature is lowered, and at least one of the local maximum points is present in a lower temperature region than T1, and at least one of the local maximum points is A toner present in a region higher in temperature than T1 is obtained. In the present embodiment, in the DSC curve measured by the differential scanning calorimeter, the maximum point observed when the temperature is lowered is not limited to that derived from the release agent. Accordingly, even if one type of release agent is used, there may be cases where a plurality of maximum points are shown when the temperature is lowered in the DSC curve measured by a differential scanning calorimeter. Specifically, a crystalline resin is used as a release agent. And using together.

The melting temperature of the release agent is preferably 50 ° C. or higher and 110 ° C. or lower, and more preferably 60 ° C. or higher and 100 ° C. or lower. The melting temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC) according to the “melting peak temperature” described in JIS K-1987 “Method for measuring the transition temperature of plastics”.
When two or more release agents are contained, it is preferable that the melting temperature of at least one release agent is 50 to 90 ° C, and the melting temperature of at least one release agent is 80 to 110 ° C, More preferably, the melting temperature of one release agent is 60 to 80, and the melting temperature of at least one release agent is 80 to 100 ° C.

The total content of the release agent is preferably, for example, 1 to 20% by weight, and more preferably 5 to 15% by weight with respect to the entire toner base particles.
When a release agent having a melting temperature in a lower temperature region than T1 and a release agent having a melting temperature in a higher temperature region than T1, the content ratio (weight ratio) is (the lower temperature region than T1). Is preferably 90:10 to 10:90, and is preferably 80:20 to 20:80. Is more preferable, and it is still more preferable that it is 80: 20-50: 50.

In the exemplary embodiment, the release agent exposed on the toner surface is preferably 40% by area or less. Since the release agent exposed on the toner surface is 40% by area or less, the surface charge density and shape distribution of the toner particles become nearly uniform, so the arrangement of toner particles in the unfixed toner image is uniform and scattered. It becomes difficult to suppress image contamination due to scattering more effectively.
Note that the release agent exposed on the toner surface is 40 area% or less means that the release agent is present in 40 area% or less of the total surface area when the area of the toner surface is 100 area%. Means that
The release agent exposed on the toner surface is more preferably 35 to 5 area%, still more preferably 30 to 5 area%.
If the surface exposure of the release agent is too high, it will be difficult to suppress image distortion due to toner scattering during fixing. In some cases, an offset is likely to occur.

The release agent exposed on the toner surface is measured by the following method.
Specifically, using a photoelectron spectrometer JSP9000MX manufactured by JEOL Ltd., toner particles are laid flat on a powder sample holder, an applied voltage of 8 kV, an emission current of 8 mA, a pass energy of 8 eV, and a scan count of 100 times. The C1s peak is measured under conditions to separate the peak due to the binder resin-derived molecular structure and the peak due to the release agent, and the ratio between the binder resin on the toner particle surface and the release agent from each peak area Is calculated.
A waveform for C1s peak separation may be obtained using measured values of a single resin or a single release agent.

In another method, the toner particles can be confirmed by staining with osmium tetroxide. The toner particles are stained with osmium tetroxide in a desiccator at 30 ° C. for 3 hours, and the dyed toner particles are subjected to secondary using an ultrahigh resolution field emission scanning electron microscope (S-4800, manufactured by Hitachi High-Technologies Corporation). Observe the increase in electrons and confirm the surface condition of the toner particles. To observe toner particles, an image is taken so that one toner particle fits in one field of view. Since the resin and the release agent are easily dyed in the order of osmium tetroxide, the exposed part of the release agent is confirmed by shading caused by the degree of dyeing. If the density is difficult to distinguish due to the condition of the sample, the staining time can be adjusted. The obtained toner particle observation image is used as electronic data, and the surface release agent ratio is calculated using image analysis software.
The image analysis software is not particularly limited. As an example, a specific method in the case of using the image analysis software (Wim ROOF) manufactured by Mitani Corporation is shown below.
After selecting the toner image as a selection target, the binarization process is performed using the “binarization process” command “automatic binarization-discriminant analysis method” to extract the exposed part of the release agent on the toner surface. At this time, it is confirmed that the exposed part of the release agent is appropriately binarized and extracted as compared with the image before binarization. If automatic binarization cannot be performed normally due to photo shooting density or noise, the image will be sharpened by “filter-median” processing or edge extraction processing, or the image will be checked using a manual binarization command. However, the floor position may be set manually.
Next, the visual field is checked, and when a portion that is not a toner particle is included in the toner visual field, the portion is excluded from analysis.
Calculate the total area of the extracted release agent part and the area of the remaining part that is not extracted as the release agent part, and add the area of the release agent part and the remaining part to the toner. The ratio of the area of the release agent portion to the entire toner particle is calculated as the entire particle surface.
This is performed for 50 or more toner particles, and the average value of the area of the release agent portion is defined as the release agent exposed area ratio.
When an external additive adheres to the toner surface and hinders measurement of the binder resin area ratio, it is preferable to perform measurement after removing the external additive on the surface of the toner particles by performing ultrasonic treatment or the like. As an example of ultrasonic treatment, 1 part of a cationic surfactant (Sanisol B50) and 100 parts of ion-exchanged water are stirred and mixed with 10 parts of toner to prepare a toner dispersion, and then the output is 20 W and the frequency is 20 kHz. The toner dispersion is filtered for 30 minutes, 100 parts of ion-exchanged water is poured over the filter paper, and the residue on the filter paper is dried using a freeze vacuum dryer to remove external additives. Toner particles can be obtained. Using a scanning microscope or the like, confirm the remaining of the external additive on the toner surface or damage of the toner particles, and adjust the intensity of ultrasonic vibration and the applied time.
Using the toner particles from which the external additive has been removed, the area ratio of the release agent on the surface of the toner particles is measured by measurement with a photoelectron spectrometer or observation with a field emission scanning electron microscope after ruthenium tetroxide staining.

<Colorant>
Examples of the colorant include carbon black, chrome yellow, hansa yellow, benzidine yellow, selenium yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliantamine 3B, brilliant. Carmine 6B, Dupont Oil Red, Pyrazolone Red, Resol Red, Rhodamine B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Phthalocyanine Green, Various pigments such as malachite green oxalate, or acridine series, xanthene series, azo series Various dyes such as benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, phthalocyanine, aniline black, polymethine, triphenylmethane, diphenylmethane, and thiazole Can be mentioned.

A colorant may be used individually by 1 type and may use 2 or more types together.
As the colorant, a surface-treated colorant may be used as necessary, or it may be used in combination with a dispersant. A plurality of colorants may be used in combination.
The content of the colorant is, for example, preferably 1 to 30% by weight, and more preferably 3 to 15% by weight with respect to the whole toner base particles.

<Other additives>
In addition to the components described above, various components such as an internal additive and a charge control agent may be added to the toner base particles 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.
Examples of the charge control agent include quaternary ammonium salt compounds, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium, and triphenylmethane pigments.

The toner base particles used in the exemplary embodiment are not particularly limited by the production method, and a known method can be used. Specific examples include the following methods.
The production of the toner base particles is obtained, for example, by a kneading and pulverizing method in which a binder resin, a colorant, a release agent, and a charge control agent, if necessary, are kneaded, pulverized, and classified; To change the shape of the particles by mechanical impact force or thermal energy; dispersion of emulsified binder resin, dispersion of colorant, release agent, and charge control agent as required An emulsion aggregation method in which toner particles are obtained by mixing, aggregating and heating and fusing the solution; emulsion polymerization of a polymerizable monomer of a binder resin, and a formed dispersion, a colorant, a release agent, and , An emulsion polymerization aggregation method to obtain toner particles by mixing with a dispersion such as a charge control agent, if necessary, and then fusing and heat-fusing; a polymerizable monomer for obtaining a binder resin, a colorant, A suspension polymerization method in which a release agent and, if necessary, a solution such as a charge control agent are suspended in an aqueous solvent for polymerization; Resin and a colorant, releasing agent, and dissolution suspension method and granulated with a solution such as a charge control agent is suspended in an aqueous solvent optionally; or the like can be used. Further, a manufacturing method may be performed in which the toner base particles obtained by the above method are used as a core, and aggregated particles are further adhered and heat-fused to have a core-shell structure.
Among these, the toner of the exemplary embodiment is preferably a toner (emulsion aggregation toner) obtained by an emulsion aggregation method or an emulsion polymerization aggregation method.

<Characteristics of toner particles>
The toner particles may be toner particles having a single layer structure, or toner particles having a so-called core / shell structure composed of a core (core particle) and a coating layer (shell layer) covering the core. May be.
Here, the core / shell structure toner particles include, for example, a core portion including a binder resin and, if necessary, other additives such as a colorant and a release agent, and a binder resin. It is good to be comprised with the comprised coating layer.

The volume average particle diameter (D50v) of the toner particles is preferably 2 μm or more and 10 μm or less, and more preferably 4 μm or more and 8 μm or less.
The various particle diameters and various particle size distribution indexes of the toner particles use Coulter Multisizer II (manufactured by Beckman Coulter, Inc.), and the electrolyte uses ISOTON-II (manufactured by Beckman Coulter, Inc.). Measured.
In the measurement, 0.5 mg to 50 mg of a measurement sample is added as a dispersant to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzenesulfonate). This is added to 100 ml or more and 150 ml or less of the electrolytic solution.
The electrolyte in which the sample is suspended is dispersed for 1 minute with an ultrasonic disperser, and the particle size distribution of particles having a particle size in the range of 2 μm to 60 μm is measured using a 100 μm aperture with a Coulter Multisizer II. taking measurement. The number of particles to be sampled is 50,000.
A cumulative distribution is drawn from the smaller diameter side to the particle size range (channel) divided based on the measured particle size distribution, and the cumulative particle size of 16% is the volume particle size D16v. D16p, the particle size of 50% cumulative is defined as volume average particle size D50v, number average particle size D50p, and the particle size of cumulative 84% is defined as volume particle size D84v, number particle size D84p.
Using these, the volume average particle size distribution index (GSDv) is calculated as (D84v / D16v) ^1/2 and the number average particle size distribution index (GSDp) is calculated as (D84p / D16p) ^1/2 .

The toner particle shape factor SF1 is preferably 110 or more and 150 or less, and more preferably 120 or more and 140 or less.
The shape factor SF1 is obtained by the following formula.

In the above formula, ML represents the maximum length of each toner base particle, and A represents the projected area of each toner base particle.
The average value of the shape factor SF1 (average shape factor) is obtained by taking 1,000 toner images magnified 250 times from an optical microscope to an image analyzer (LUZEX III, manufactured by Nireco Corporation), and the maximum From the length and the projected area, the value of the SF1 is obtained for each particle and averaged.

<External additive>
In this embodiment, the electrostatic image developing toner preferably contains toner base particles and an external additive externally added to the toner base particles.
Examples of the external additive include inorganic particles. As the inorganic particles, TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, CaO, K ₂ O, Na ₂ O, ZrO ₂ , CaO · SiO ₂ , Examples include K ₂ O. (TiO ₂ ) _n , Al ₂ O ₃ .2SiO ₂ , CaCO ₃ , MgCO ₃ , BaSO ₄ , MgSO _{4 and the} like.
The surface of the inorganic particles as an external additive is preferably subjected to a hydrophobic treatment. The hydrophobic treatment is performed, for example, by immersing inorganic particles in a hydrophobic treatment agent. The hydrophobizing agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, aluminum coupling agents and the like. These may be used individually by 1 type and may use 2 or more types together.
The amount of the hydrophobizing agent is usually 1 part or more and 10 parts per 100 parts of inorganic particles, for example.
Part.

  Examples of external additives include resin particles (resin particles such as polystyrene, PMMA, and melamine resin), cleaning activators (for example, metal salts of higher fatty acids typified by zinc stearate, particles of a fluorine-based high molecular weight substance), and the like. Can be mentioned.

<Method for producing toner for developing electrostatic image>
In the present embodiment, the method for producing the electrostatic image developing toner is not particularly limited, and may be appropriately selected from known methods, such as a dry production method (for example, a kneading pulverization method), a wet production method (for example, an agglomeration play equipment method, (Suspension polymerization method, dissolution suspension method, etc.)
Among these, in this embodiment, a process of forming aggregated particles in a dispersion in which at least resin fine particles are dispersed to prepare an aggregated particle dispersion (aggregation process), and heating the aggregated particle dispersion to aggregate A production method including a step of fusing particles (fusion step) (hereinafter, the production method may be referred to as “aggregation fusion method”) is preferable. Further, between the aggregation step and the fusion step, a step of adding and mixing the fine particle dispersion in which the fine particles are dispersed in the aggregated particle dispersion and attaching the fine particles to the aggregated particles to form the attached particles (attachment step) ) May be provided.

In the attaching step, the fine particle dispersion is added to and mixed with the aggregated particle dispersion prepared in the aggregation step, and the fine particles are attached to the aggregated particles to form attached particles. The added fine particles correspond to particles newly added to the aggregated particles when viewed from the aggregated particles, and may be referred to as “additional fine particles” in this specification.
As the additional fine particles, in addition to the resin fine particles, release agent fine particles, colorant fine particles and the like may be used singly or in combination. The method of additionally mixing the fine particle dispersion is not particularly limited, and may be performed gradually, for example, or may be performed stepwise by dividing into a plurality of times. Thus, by adding and mixing the fine particles (additional fine particles), the generation of fine particles can be suppressed, and the particle size distribution of the resulting electrostatic image developing toner can be sharpened, resulting in higher image quality. Can contribute.

  Also, by providing the adhesion step, a pseudo shell structure can be formed, and the toner surface exposure of internal additives such as a colorant and a release agent can be reduced, and as a result, the chargeability and the life can be improved. In addition, it is possible to maintain the particle size distribution during fusion in the fusion process, to suppress fluctuations, and to add a stabilizer such as a surfactant or base or acid to enhance stability during fusion. This is advantageous in that it can be eliminated and the amount of addition can be suppressed to the minimum, and costs can be reduced and quality can be improved. Therefore, when using a release agent, it is preferable to add additional fine particles mainly composed of resin fine particles. If this method is used, the toner shape can be easily controlled by adjusting the temperature, the number of stirrings, the pH and the like in the fusing step.

The method for preparing the dispersion of resin fine particles is not particularly limited, and a method appropriately selected according to the purpose can be adopted. For example, it can be prepared as follows.
When the resin in the resin fine particles is a homopolymer or copolymer (vinyl resin) of a vinyl monomer such as the ester having a vinyl group, the vinyl nitrile, the vinyl ether, or the vinyl ketone. For example, the vinyl monomer is emulsion-polymerized or seed-polymerized in an ionic surfactant to obtain resin fine particles made of a vinyl monomer homopolymer or copolymer (vinyl resin). A dispersion obtained by dispersing in an ionic surfactant can be prepared.
When the resin in the resin fine particles is a resin other than the homopolymer or copolymer of the vinyl monomer such as a styrene-acrylic resin, the resin has a relatively high solubility in water. If it dissolves in a low oil solvent, the resin is dissolved in the oil solvent, and this dissolved material is added to the water together with the ionic surfactant and polymer electrolyte, and fine particles are added using a disperser such as a homogenizer. After the dispersion, it can be prepared by evaporating the oily solvent by heating or reducing the pressure.

When the resin fine particles dispersed in the resin fine particle dispersion are composite particles containing components other than the resin fine particles, a dispersion in which these composite particles are dispersed can be prepared, for example, as follows. it can.
That is, after each component of the composite particles is dissolved and dispersed in a solvent, it is dispersed in water with an appropriate dispersant as described above, and the solvent is removed by heating or decompression, emulsion polymerization, It can be prepared by a method of immobilizing by performing mechanical shearing or electroadsorption on the latex surface prepared by seed polymerization.

  The center diameter (median diameter) of the resin fine particles is preferably 1 μm or less, more preferably 50 to 400 nm, still more preferably 70 to 350 nm. When the median diameter of the resin fine particles is 400 nm or less, the particle size distribution of the finally obtained electrostatic image developing toner is narrow, the generation of free particles is suppressed, and the performance and reliability are improved. Further, if it is 50 nm or more, the dispersion viscosity at the time of producing the toner is low, and the particle size distribution of the finally obtained toner is preferably narrowed. When the average particle diameter of the resin fine particles is within the above range, the uneven distribution between the toners is reduced, the dispersion in the toners is improved, and the variation in performance and reliability is advantageously reduced. In addition, the average particle diameter of the resin fine particles can be measured, for example, with a laser diffraction particle size distribution analyzer (manufactured by Horiba, Ltd .: LA-700).

  In order to produce a colorant dispersion, there are various methods using a polar surfactant, for example, a media-type disperser such as a rotary shear type homogenizer, a ball mill, a sand mill, and an attritor. In order to obtain the toner, a method in which the pigments are collided with each other by a high-pressure opposed collision type disperser is preferable.

  The mold release agent dispersion is dispersed in water together with a polymer electrolyte such as an ionic surfactant, polymer acid, polymer base, etc. in water, heated above the melting temperature, and has a strong shearing ability. It can be dispersed in the form of fine particles with a homogenizer or a pressure discharge type disperser (manufactured by Gorin Co., Ltd .: Gorin homogenizer) to produce a dispersion of particles of 1 μm or less. The particle size of the release agent particle dispersion is measured, for example, with a laser diffraction particle size distribution analyzer (manufactured by Horiba, Ltd .: LA-700).

  In the agglomeration and fusion method, an aggregating agent can be added to agglomerate components such as resin fine particles and release agent particles. However, in the toner of the present invention, this aggregating agent is also used as a factor for controlling viscoelasticity. can do. The flocculant is obtained by dissolving a general inorganic metal compound or a polymer thereof in a resin fine particle dispersion, and the metal elements constituting the inorganic metal salt are 2A and 3A in the periodic table (long period table). 4A, 5A, 6A, 7A, 8, 1B, 2B, 3B, or any other charge having a valence of 2 or more, and can be dissolved in the form of ions in the aggregation system of resin fine particles.

Specific examples of preferred inorganic metal salts include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, aluminum sulfate, and polyaluminum chloride, polyaluminum hydroxide, calcium polysulfide. And inorganic metal salt polymers. Among these, an aluminum salt and a polymer thereof are particularly preferable. In general, in order to obtain a sharper particle size distribution, even if the valence of the inorganic metal salt is divalent to monovalent, bivalent to trivalent or higher, and even to the same valence, the polymerization type inorganic metal salt weight Combined is more suitable. The viscoelasticity of the toner can be controlled by changing the cohesion force between the materials by the valence and the addition amount.
A polymer flocculant can also be used. Polyacrylamide-based anionic polymer flocculants, dimethylaminoethyl methacrylate-based cationic polymer flocculants, amphoteric polymer flocculants, and the like can also be used.

  Although the detailed viscoelasticity relationship between the flocculant and the toner using the flocculant has not been clarified, if the amount of the flocculant remaining in the toner is large, the melt viscosity tends to increase. There is a tendency that a large number of flocculants have a high effect of increasing the melt viscosity, and a flocculant having a low molecular weight has a high effect of increasing the melt viscosity. Since it varies greatly depending on the properties of the release agent fine particles and pigment fine particles, the temperature and pH in the dispersion liquid being produced, and the solid content concentration, it is necessary to select one or a mixture of suitable types.

  Examples of the dispersion medium in the resin fine particle dispersion, the release agent dispersion, and the dispersion in which the other components (particles) are dispersed include an aqueous medium. Examples of the aqueous medium include water such as distilled water and ion exchange water, and alcohols. These may be used individually by 1 type and may use 2 or more types together.

  The means for preparing the various additive dispersions is not particularly limited, and examples thereof include a method using a dispersion apparatus known per se such as a rotary shear type homogenizer or a ball mill having a media, a sand mill, or a dyno mill.

  In the present invention, a surfactant may be added to and mixed with the aqueous medium in order to protect the particle size distribution stability. Examples of the surfactant include anionic surfactants such as sulfate ester, sulfonate, phosphate, and soap; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol Preferable examples include nonionic surfactants such as polyphenols, alkylphenol ethylene oxide adducts, and polyhydric alcohols. Among these, an ionic surfactant is preferable, and an anionic surfactant and a cationic surfactant are more preferable. The nonionic surfactant is preferably used in combination with the anionic surfactant or the cationic surfactant. The said surfactant may be used individually by 1 type, and may use 2 or more types together. In general, in many cases, an excessive amount of a surfactant is intentionally added in a resin fine particle dispersion or a pigment dispersion to increase the stability of particle size distribution during toner preparation.

  Specific examples of the anionic surfactant include fatty acid soaps such as potassium laurate, sodium oleate and sodium castor oil; sulfates such as octyl sulfate, lauryl sulfate, lauryl ether sulfate and nonyl phenyl ether sulfate; lauryl sulfonate , Dodecyl sulfonate, dodecyl benzene sulfonate, triisopropyl naphthalene sulfonate, dibutyl naphthalene sulfonate sodium alkylnaphthalene sulfonate, naphthalene sulfonate formalin condensate, monooctyl sulfosuccinate, dioctyl sulfosuccinate, lauric acid amide sulfonate, oleic acid amide sulfonate Sulfonates such as lauryl phosphate, isopropyl phosphate, Phosphoric acid esters such as alkenyl phenyl ether phosphates; dialkyl sodium sulfosuccinates of sodium dioctyl sulfosuccinate, sodium lauryl sulfosuccinate 2, polyoxyethylene sulfo sulfosuccinate salts such as succinic acid lauryl disodium and the like.

  Specific examples of the cationic surfactant include laurylamine hydrochloride, stearylamine hydrochloride, oleylamine acetate, stearylamine acetate, stearylaminopropylamine acetate, and other amine salts; lauryltrimethylammonium chloride, dilauryldimethylammonium Chloride, distearyl ammonium chloride, distearyl dimethyl ammonium chloride, lauryl dihydroxyethyl methyl ammonium chloride, oleyl bispolyoxyethylene methyl ammonium chloride, lauroylaminopropyldimethylethylammonium ethosulphate, lauroylaminopropyldimethylhydroxyethylammonium perchlorate, alkylbenzene dimethyl Ammonium chloride, alkylto Such as quaternary ammonium salts such as ammonium chloride.

  Specific examples of the nonionic surfactant include polyoxyethylene octyl ether, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether and other alkyl ethers; Alkylphenyl ethers such as oxyethylene nonylphenyl ether; alkyl esters such as polyoxyethylene laurate, polyoxyethylene stearate, polyoxyethylene oleate; polyoxyethylene lauryl amino ether, polyoxyethylene stearyl amino ether, polyoxy Alkylamines such as ethylene oleyl amino ether, polyoxyethylene soybean amino ether, polyoxyethylene beef tallow amino ether; Alkyl amides such as xylethylene lauric acid amide, polyoxyethylene stearic acid amide, polyoxyethylene oleic acid amide; vegetable oil ethers such as polyoxyethylene castor oil ether, polyoxyethylene rapeseed oil ether; lauric acid diethanolamide, stearin Alkanolamides such as acid diethanolamide and oleic acid diethanolamide; sorbitan ester ethers such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate And the like.

  The toner in the present invention is a dispersion of aggregated particles containing at least a resin fine particle and a release agent mixed with a resin fine particle dispersion in which the resin fine particles are dispersed, a release agent dispersion, a colorant dispersion, and the like. Then, the resin particles are heated to a glass transition point or a temperature higher than the melting temperature of the resin fine particles, and the aggregated particles are melted and integrated to form toner particles. As described above, the resin fine particle dispersion can be prepared by an emulsion polymerization method or the like. An ionic surfactant having the opposite polarity to that of the ionic surfactant contained in the resin fine particle dispersion. Prepare a dispersion by dispersing the release agent and colorant. In this method, aggregated particles corresponding to the toner particle size are formed, and then heated to a glass transition point of resin fine particles or a temperature equal to or higher than the melting temperature, whereby the aggregated particles are melted to obtain toner particles.

  Heteroaggregation may be agglomerated by mixing the raw material dispersions together, but the initial polar ionic dispersant amount balance is shifted in advance, for example, an inorganic metal salt such as calcium nitrate, Using tetravalent aluminum salts such as polyaluminum chloride and polyaluminum hydroxide, and their polymers, they are ionically neutralized to form the first-stage aggregated particles at a temperature lower than the glass transition point. Then, as a second step, a particle dispersant having a selected polarity and amount is added so as to compensate for a deviation in the balance of ions, and if necessary, the glass transition point of the resin contained in the base particles or the additional particles or Slightly heat at a temperature below the melting temperature and stabilize at a higher temperature, then heat to a temperature above the glass transition point or the melting temperature to attach the particles added in the second stage to the surface of the base aggregated particles The It was melted while it is also possible to obtain toner particles. Further, the stepwise operation of aggregation may be repeated a plurality of times.

  After completion of the melting / particle forming step, the toner particles are washed and dried to obtain a toner. In consideration of the chargeability of the toner, it is preferable to sufficiently perform substitution washing with ion-exchanged water, and the degree of washing is generally monitored by the conductivity of the filtrate. The solid-liquid separation after washing is not particularly limited, but suction filtration, pressure filtration, etc. are preferably used from the viewpoint of productivity. Further, the drying method is not particularly limited, but from the viewpoint of productivity, freeze drying, airflow dryer, fluidized drying, vibration fluidized drying and the like are preferably used.

More specifically, using the materials as described above, at least the resin fine particle dispersion and the release agent dispersion are included, and other components such as the colorant dispersion are added and mixed as necessary. The dispersion prepared in this manner is heated at room temperature to a glass transition temperature of the resin plus about 5 ° C. with stirring, thereby agglomerating the resin fine particles and the release agent to form aggregate particles. From the viewpoint of controlling the toner particle size distribution, it is preferable to additionally add resin fine particles when the volume average particle size of the aggregate particles is in the particle size range of 70 to 90% of the final target particle size of the toner.
Resin fine particles are additionally added to the aggregate particles thus formed to form a coating layer on the surface of the aggregate particles. The amount of resin fine particles added is preferably in the range of 15 to 45% by weight of the total amount of resin fine particles to be added. When the added amount of the additional resin fine particles is 15% by weight or more, the effect of controlling the particle size distribution is excellent. When the addition amount of the additional resin fine particles is 45% by weight or less, the adhesion of the additional resin fine particles to the aggregate fine particles is good and the particle size distribution is excellent. The time for attaching the additional resin fine particles to the aggregate fine particles is preferably in the range of 10 to 90 minutes. Within the above range, adhesion is excellent, abnormal adhesion is suppressed, and particle size distribution is good.

  Next, aggregation is stopped by a method such as pH adjustment or addition of a surfactant, and heat treatment is performed at a temperature equal to or higher than the softening point of the resin, generally in the range of 70 to 120 ° C. A liquid (toner particle dispersion) is obtained. The obtained toner particle-containing liquid is treated by centrifugal separation or suction filtration to separate the toner particles, and washed 1 to 3 times with ion exchange water. At that time, the cleaning effect can be further enhanced by adjusting the pH. Thereafter, the toner particles are filtered off, washed 1 to 3 times with ion-exchanged water, and dried, whereby the toner of this embodiment can be obtained.

  The absolute value of the charge amount of the toner in the present invention is preferably in the range of 10 to 50 μC / g, and more preferably in the range of 15 to 35 μC / g. If the charge amount is less than 10 μC / g, background stains tend to occur, and if it exceeds 50 μC / g, the image density tends to decrease. Further, the ratio of the charge amount under high temperature and high humidity of 30 ° C. and 80 RH% and under low temperature and low humidity of 10 ° C. and 20% RH is preferably in the range of 0.5 to 1.5, 0.7 to A range of 1.2 is more preferred. When the ratio is within the range, a clear image can be obtained without being affected by the environment.

In addition, inorganic particles and organic particles can be added to the toner finally heated as described above as a fluidity aid, a cleaning aid, an abrasive and the like.
Further, a lubricant can be added. Examples of the lubricant include fatty acid amides such as ethylene bisstearylamide and oleic acid amide, and fatty acid metal salts such as zinc stearate and calcium stearate.

(Electrostatic image developer)
The toner for developing an electrostatic charge image of this embodiment is suitably used as an electrostatic charge image developer.
The electrostatic image developer of the present embodiment is not particularly limited except that it contains the toner of the present embodiment, and can take an appropriate component composition depending on the purpose. When the toner of this embodiment is used alone, it is prepared as a one-component electrostatic image developer, and when used in combination with a carrier, it is prepared as a two-component electrostatic image developer.
As a one-component developer, a method in which a charged toner is formed by frictional charging with a developing sleeve or a charging member, and development is performed according to an electrostatic latent image is also applied.

  In the present embodiment, the development method is not particularly defined, but the two-component development method is preferable. The carrier is not particularly defined as long as the above conditions are satisfied. Examples of the carrier core material include magnetic metals such as iron, steel, nickel, and cobalt, alloys of these with manganese, chromium, rare earth, and the like, and Magnetic oxides such as ferrite and magnetite are mentioned, and from the viewpoint of core material surface properties and core material resistance, ferrite, particularly alloys with manganese, lithium, strontium, magnesium and the like are preferably mentioned.

The carrier used in this embodiment is preferably formed by coating the surface of the core material with a resin. There is no restriction | limiting in particular as said resin, According to the objective, it selects suitably. For example, polyolefin resins such as polyethylene and polypropylene; polyvinyl resins and polyvinylidene resins such as polystyrene, acrylic resins, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether and polyvinyl ketone Vinyl chloride-vinyl acetate copolymer; styrene-acrylic acid copolymer; straight silicone resin composed of organosiloxane bond or modified product thereof; polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene, etc. Fluorine resin; Silicone resin; Polyester; Polyurethane; Polycarbonate; Phenol resin; Urea-formaldehyde resin, Melamine tree , Benzoguanamine resins, urea resins, amino resins such as polyamide resins, epoxy resins, per se known resins and the like. These may be used individually by 1 type and may use 2 or more types together. In the present embodiment, among these resins, it is preferable to use at least a fluorine resin and / or a silicone resin. The use of at least a fluorine-based resin and / or a silicone resin as the resin is advantageous in that the effect of preventing carrier contamination (impaction) due to toner and external additives is high.
In the resin coating, it is preferable that resin particles and / or conductive particles are dispersed in the resin. Examples of the resin particles include thermoplastic resin particles and thermosetting resin particles. Among these, thermosetting resins are preferable from the viewpoint of relatively easily increasing the hardness, and resin particles made of nitrogen-containing resin containing N atoms are preferable from the viewpoint of imparting negative chargeability to the toner. 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 preferably 0.1 to 2 μm, and more preferably 0.2 to 1 μm. When the average particle diameter of the resin particles is 0.1 μm or more, the resin particles are excellent in dispersibility in the coating film.

  Examples of the conductive particles include metal particles such as gold, silver, and copper, carbon black particles, and surfaces of titanium oxide, zinc oxide, barium sulfate, aluminum borate, potassium titanate powder, tin oxide, carbon black, metal And particles covered with the like. These may be used individually by 1 type and may use 2 or more types together. Among these, carbon black particles are preferable in terms of good 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 50 to 250 ml / 100 g is preferable because of excellent production stability. The coating amount of the resin, the resin particles, and the conductive particles on the surface of the core material is preferably 0.5 to 5.0% by weight, and preferably 0.7 to 3.0% by weight. More preferred.

The method for forming the coating is not particularly limited. For example, the resin particles such as crosslinkable resin particles and / or the conductive particles, and a styrene acrylic resin, a fluorine resin, a silicone resin as a matrix resin, etc. And a method of using a film-forming solution containing the above resin in a solvent.
Specifically, the carrier core material is immersed in the coating forming solution, and the carrier core material is coated on the surface of the core material by depressurization or heating while the carrier core material is immersed in the coating forming solution and then mixed and stirred. A kneader coater method for forming a film, a spray method for spraying a film-forming liquid onto the surface of the carrier core material, and mixing the film-forming liquid in a state where the carrier core material is suspended by flowing air to remove the solvent. Examples include fluidized bed method. Among these, the kneader coater method is preferable in the present embodiment.

  The solvent used for the film-forming liquid is not particularly limited as long as it can dissolve only the resin as a matrix resin, and is selected from known solvents such as toluene, Aromatic hydrocarbons such as xylene, ketones such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran and dioxane, and the like. When the resin particles are dispersed in the coating, since the resin particles and the particles as the matrix resin are uniformly dispersed in the thickness direction and the tangential direction of the carrier surface, the carrier is used for a long time. Even when the coating is worn, it is possible to always maintain the same surface formation as when it is not used, and to maintain a good charge imparting ability for the toner over a long period of time. In the case where the conductive particles are dispersed in the coating, the conductive particles and the resin as the matrix resin are uniformly dispersed in the thickness direction and the tangential direction of the carrier surface. Even if the coating is worn out over a long period of time, the same surface formation as when not in use can be maintained, and carrier deterioration is prevented for a long period of time. In addition, when the said resin particle and the said electroconductive particle are disperse | distributed to the said film, the above-mentioned effect is exhibited simultaneously.

The electric resistance of the magnetic carrier formed as described above in the state of a magnetic brush under an electric field of 10 ⁴ V / cm is preferably 10 ⁶ to 10 ¹⁵ Ωcm. When the electric resistance of the magnetic carrier is 10 ⁶ Ωcm or more, the adhesion of the carrier to the image portion on the image carrier is suppressed, and the charge of the latent image on the image carrier leaks to the carrier. The so-called brush mark is difficult to appear. On the other hand, if the electric resistance of the magnetic carrier is 10 ¹⁵ Ωcm or less, the effective developing distance is shortened so that it is difficult to be influenced by the edge electric field at the boundary portion of the electrostatic latent image on the image carrier. Occurrence of the edge effect is suppressed and good image quality is obtained. The electric resistance is more preferably 10 ⁸ to 10 ¹³ Ωcm, and the above effect is further exhibited.
The electrical resistance (volume specific resistance) is measured as follows.
A measuring jig comprising a pair of 20 cm ² circular electrode plates (made of steel) connected to an electrometer (manufactured by KEITHLEY, trade name: KEITHLEY 610C) and a high-voltage power supply (trade name: FLUKE 415B). The sample is placed on the lower electrode plate so as to form a flat layer having a thickness of about 1 mm to 3 mm. Next, after the upper electrode plate is placed on the sample, a weight of 4 kg is placed on the upper electrode plate in order to eliminate the gap between the samples. In this state, the thickness of the sample layer is measured. Next, the current value is measured by applying a voltage to the bipolar plate, and the volume resistivity is calculated based on the following equation.
Volume resistivity = applied voltage × 20 ÷ (current value−initial current value) ÷ sample thickness In the above formula, the initial current is a current value when the applied voltage is 0, and the current value indicates the measured current value.

  The mixing ratio of the toner of the present embodiment and the carrier in the two-component electrostatic image developer is preferably 2 to 20 parts by weight of the electrostatic image developing toner with respect to 100 parts by weight of the carrier. Moreover, the preparation method of a developing agent is not specifically limited, For example, the method of mixing with a V blender etc. is mentioned.

(Image forming method)
The electrostatic charge image developer (toner mixture) is used in an electrostatic charge image development (electrophotographic) image forming method.
The image forming method of the present embodiment includes a latent image forming step of forming an electrostatic latent image on the surface of the image carrier, and developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner. A developer step for forming a toner image; a transfer step for transferring the toner image to the surface of the transfer target; and a fixing step for fixing the toner image transferred to the surface of the transfer target; The toner mixture of the present embodiment or the electrostatic charge image developer of the present embodiment is used.
The image forming method of this embodiment preferably includes a cleaning step of cleaning the electrostatic charge image developer remaining on the image carrier in addition to the above steps.

Each of the above steps is a general step per se, and is described in, for example, JP-A-56-40868 and JP-A-49-91231. Note that the image forming method of the present embodiment can be carried out by using a known image forming apparatus such as a copying machine or a facsimile machine.
The electrostatic latent image forming step is a step of forming an electrostatic latent image on an image carrier (photoconductor).
The developing step is a step of developing the electrostatic latent image with a developer layer on a developer holding member to form a toner image. The developer layer is not particularly limited as long as it contains the electrostatic image developing toner of this embodiment.
The transfer step is a step of transferring the toner image onto a transfer target. Examples of the transfer medium in the transfer process include an intermediate transfer medium and a recording medium such as paper.
In the fixing step, for example, there is a method of forming a copy image by fixing the toner image transferred onto the transfer paper by a heating roller fixing device in which the temperature of the heating roller is set to a constant temperature.
The cleaning step is a step of cleaning the developer remaining on the image carrier.
In the image forming method of the present embodiment, it is more preferable that the cleaning step includes a step of removing the electrostatic charge image developer remaining on the image carrier with a cleaning blade.
As the recording medium, known media can be used, for example, paper used for electrophotographic copying machines, printers, OHP sheets, etc. For example, the surface of plain paper is made of resin, etc. Coated coated paper, art paper for printing, and the like can be suitably used.

  The image forming method of the present embodiment may further include a recycling step. The recycling step is a step of transferring the electrostatic image developing toner collected in the cleaning step to the developer layer. The image forming method including the recycling process is performed using an image forming apparatus such as a toner recycling system type copying machine or facsimile machine. Further, the present invention may be applied to a recycling system that collects toner simultaneously with development.

(Image forming device)
The image forming apparatus according to this embodiment includes an image carrier, a charging unit that charges the image carrier, and an exposure unit that exposes the charged image carrier to form an electrostatic latent image on the surface of the image carrier. Developing means for developing the electrostatic latent image with a developer containing toner to form a toner image; transfer means for transferring the toner image from the image holding member to the surface of the transferred body; and the transferred body Fixing means for fixing the toner image transferred to the surface, and the developer of the present embodiment or the electrostatic charge image developer of the present embodiment is used as the developer.
The image forming apparatus according to the present exemplary embodiment preferably includes a cleaning unit that cleans the image carrier.
The image forming apparatus of the present embodiment is not particularly limited as long as it includes at least the image carrier, the charging unit, the exposure unit, the developing unit, the transfer unit, and the fixing unit as described above. However, other cleaning means, static elimination means, and the like may be included as necessary.
In the transfer unit, the transfer may be performed twice or more using an intermediate transfer member. Examples of the transfer medium in the transfer unit include an intermediate transfer medium and a recording medium such as paper.

As the image carrier and each of the above-described units, the configurations described in the respective steps of the image forming method are preferably used. As each of the above-described means, a known means in the image forming apparatus can be used. In addition, the image forming apparatus according to the present embodiment may include means and devices other than the above-described configuration. Further, the image forming apparatus according to the present embodiment may simultaneously perform a plurality of the above-described means.
Examples of the cleaning means for cleaning the electrostatic charge image developer remaining on the image holding member include a cleaning blade and a cleaning brush, and a cleaning blade is preferable.
Preferred examples of the cleaning blade material include urethane rubber, neoprene rubber, and silicone rubber.

(Toner cartridge, developer cartridge, and process cartridge)
The toner cartridge of the present embodiment is a toner cartridge that contains at least the toner mixture of the present embodiment.
The developer cartridge of this embodiment is a developer cartridge that contains at least the electrostatic charge image developer of this embodiment.
In addition, the process cartridge according to the present embodiment includes a developing unit that develops an electrostatic latent image formed on the surface of the image carrier with the toner mixture or the electrostatic image developer to form a toner image, and an image carrier. And at least one selected from the group consisting of a charging unit for charging the surface of the image carrier and a cleaning unit for removing the toner remaining on the surface of the image carrier. This is a process cartridge containing at least the toner for developing an electrostatic image or the electrostatic image developer of this embodiment.

The toner cartridge of this embodiment is preferably detachable from the image forming apparatus. That is, in the image forming apparatus having a configuration in which the toner cartridge can be attached and detached, the toner cartridge of the present embodiment that stores the toner of the present embodiment is preferably used.
The developer cartridge of the present embodiment is not particularly limited as long as it contains the electrostatic charge image developer containing the electrostatic charge image developing toner of the present embodiment. The developer cartridge is, for example, attached to and detached from an image forming apparatus including a developing unit, and includes the electrostatic image developer according to the present embodiment as a developer to be supplied to the developing unit. Is stored.
The developer cartridge may be a cartridge that stores the toner mixture and the carrier, or may be a cartridge that stores the toner mixture and a cartridge that stores the carrier alone.
It is preferable that the process cartridge of the present embodiment is attached to and detached from the image forming apparatus.
In addition, the process cartridge according to the present embodiment may include other members such as a static elimination unit as necessary.
As the toner cartridge and the process cartridge, known configurations may be adopted. For example, Japanese Patent Application Laid-Open Nos. 2008-209489 and 2008-233736 are referred to.

  Hereinafter, although an embodiment explains this embodiment in detail, this embodiment is not limited to these examples at all. In the following description, “part” and “%” are all based on weight unless otherwise specified.

(Measuring method)
<Measurement of tan δ in dynamic viscoelastic rheometer viscoelasticity measurement and temperature T1 at which tan δ exhibits a maximum value>
The dynamic viscoelastic rheometer viscoelasticity measurement is performed using a rotary plate rheometer ARES (manufactured by Rheometrics) using a parallel plate having a diameter of 8 mm, a frequency of 1 red / second, an applied strain initial value of 0.01%, and a maximum strain of 20%. In the range of maximum torque 100 and minimum torque 10, automatic strain adjustment was performed, and the temperature increase measurement was performed between 30 ° C. and 180 ° C. at a temperature increase rate of 1 ° C./min and a sample mass of 0.3 g.

<Measurement during cooling on DSC curve>
・ Suggested scanning calorimetry (DSC)
The differential scanning calorimetry in this embodiment was performed by the following method.
As a differential scanning calorimeter, DSC-60A (manufactured by Shimadzu Corporation) was used. In the measurement, first, as a first temperature raising step, the temperature is raised at a rate of 10 ° C. per minute from 10 ° C. to 200 ° C. after being held at 10 ° C. for 10 minutes. Next, after performing the first temperature raising step, the temperature is maintained at 200 ° C. for 10 minutes as it is, and then cooled to −10 ° C. at a rate of −10 ° C. per minute using liquefied nitrogen and held at −10 ° C. for 10 minutes. To do. The number of maximum points and the temperature were confirmed from the differential scanning calorimetry curve obtained at this time.

<Releasing agent area ratio>
The ratio of the release agent present on the surface of the toner particles was calculated as follows.
Using a photoelectron spectrometer JSP9000MX manufactured by JEOL Ltd., the toner particles are laid flat on a powder sample holder and measured under the conditions of an applied voltage of 8 kV, an emission current of 8 mA, a pass energy of 8 eV, and a scan count of 100 times. For the C1s peak, the peak from the molecular structure derived from the binder resin and the peak from the molecular structure derived from the release agent were separated, and the ratio of the release agent was calculated from the respective peak areas.
A waveform for C1s peak separation may be obtained using measured values of a single resin or a single release agent.
When an external additive adheres to the toner surface and hinders measurement of the area ratio of the release agent, it is preferable to perform measurement after removing the external additive on the surface of the toner particles by performing ultrasonic treatment or the like. As an example of ultrasonic treatment, 1 part of a cationic surfactant (Sanisol B50) and 100 parts of ion-exchanged water are stirred and mixed with 10 parts of toner to prepare a toner dispersion, and then the output is 20 W and the frequency is 20 kHz. After adding 30 minutes of ultrasonic vibration, the toner dispersion is filtered, 100 parts of ion-exchanged water is poured over the filter paper, and the residue on the filter paper is dried using a freeze vacuum dryer to obtain an external additive. It is possible to obtain toner particles from which the toner is removed. Using a scanning microscope or the like, confirm the remaining of the external additive on the toner surface or damage of the toner particles, and adjust the intensity of ultrasonic vibration and the applied time.
Using the toner particles from which the external additive has been removed, the area ratio of the release agent on the surface of the toner particles is measured by measurement with a photoelectron spectrometer or observation with a field emission scanning electron microscope after ruthenium tetroxide staining.

(Preparation of toner for developing electrostatic image)
<Preparation of resin particle dispersion (1) (styrene-based resin)>
A mixture of 380 parts of styrene, 20 parts of n-butyl acrylate, 10 parts of acrylic acid, and 20 parts of dodecanethiol was dissolved in 10 parts of a nonionic surfactant (Nonipol 400: manufactured by Sanyo Chemical Co., Ltd.) and an anion. -Soluble surfactant (Neogen SC: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was emulsion-polymerized in a flask in which 550 parts of ion-exchanged water was dissolved, and 6 parts of ammonium persulfate was dissolved in this while slowly mixing for 60 minutes. 60 parts of ion-exchanged water was added. After carrying out nitrogen substitution, the inside of the flask was stirred and heated in an oil bath until the content reached 80 ° C., and emulsion polymerization was continued for 6 hours. Then, it cooled and obtained the resin particle dispersion liquid (1).

<Preparation of resin particle dispersion (2)>
Resin particle dispersion in the same manner as in the resin particle dispersion (1) except that 300 parts of styrene, 20 parts of n-butyl acrylate, 10 parts of acrylic acid, 60 parts of ethyl acrylate, and 20 parts of dodecanethiol were used as raw materials. A liquid (2) was obtained.

<Preparation of resin particle dispersion (3)>
A resin particle dispersion (3) is obtained in the same manner as the resin particle dispersion (1) except that 400 parts of styrene, 5 parts of n-butyl acrylate, 5 parts of acrylic acid, and 15 parts of dodecanethiol are used as raw materials. It was.

<Preparation of resin particle dispersion (4)>
A resin particle dispersion (4) is obtained in the same manner as the resin particle dispersion (1) except that 320 parts of styrene, 40 parts of n-butyl acrylate, 15 parts of acrylic acid and 15 parts of dodecanethiol are used as raw materials. It was.

<Preparation of resin particle dispersion (5)>
In a heat-dried three-necked flask, 120 parts of ethylene glycol, 25 parts of sodium dimethyl 5-sulfoisophthalate, 200 parts of dimethyl sebacate, and 0.5 parts of dibutyltin oxide as a catalyst were added, and the air in the container was reduced by a vacuum operation. The mixture was placed in an inert atmosphere with nitrogen gas, and stirred at 180 ° C. for 5 hours with mechanical stirring. Then, it heated up gradually to 220 degreeC under pressure reduction, stirred for 1 hour, air-cooled when it became a viscous state, the reaction was stopped, and resin (5) was synthesize | combined.
200 parts by weight of resin (5), 200 parts by weight of ethyl acetate, 10 parts of liquid paraffin manufactured by Wako Pure Chemical Industries, Ltd. and 0.1 part of aqueous sodium hydroxide (0.3N) are prepared and separable. It put into the flask, heated at 70 degreeC, and it stirred by the three one motor (made by Shinto Kagaku Co., Ltd.), and prepared the resin liquid mixture (5). While stirring this resin mixed solution (5), 400 parts by mass of an aqueous sodium hydroxide solution (0.05N) was gradually added to effect phase inversion emulsification and solvent removal to obtain a resin particle dispersion (5).

<Preparation of resin particle dispersion (6)>
An acid component composed of 90 mol% terephthalic acid and 10 mol% fumaric acid and an alcohol component composed of 50 mol% bisphenol A ethylene oxide 2 mol adduct and 50 mol% bisphenol A propylene oxide 2 mol adduct in a molar ratio of 1: 1. Then, the mixture was charged into a flask equipped with a stirrer, a nitrogen introduction tube, a temperature sensor, and a rectifying tower, and the temperature was raised to 85 ° C. over 3 hours in a nitrogen atmosphere, and it was confirmed that the reaction system was stirred. Thereafter, 0.5 part of dibutyltin oxide was added to 100 parts of the mixture, and the temperature was raised to 200 ° C. over 2 hours from the same temperature while distilling off the generated water, and further at 200 ° C. for 5 hours. The dehydration condensation reaction was continued to obtain Resin (6).
Subsequently, the obtained resin (6) was transferred in a molten state to Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) at a rate of 100 g / min. In a separately prepared aqueous medium tank, 0.4% strength diluted ammonia water obtained by diluting reagent ammonia water with ion exchange water is put, and heated at 96 ° C. with a heat exchanger at a rate of 0.1 liter per minute, Simultaneously with the resin (6) melt, it was transferred to Cavitron CD1010 (manufactured by Eurotech Co., Ltd.). The Cavitron was operated under conditions of a rotor rotation speed of 60 Hz and a pressure of 5 kg / cm ² . Thereafter, the pH in the system was adjusted to 8.6 with a 0.4 mol / l sodium hydroxide aqueous solution and treated at 50 ° C. for 5 hours, and then adjusted to pH 7.2 with an aqueous nitric acid solution. (6) was obtained.

<Preparation of release agent particle dispersion (1)>
Paraffin wax (HNP-9: Nippon Seiwa Co., Ltd., melting temperature 65 ° C.): 100 parts Cationic surfactant (Sanisol B50: Kao Corporation): 20 parts Ion exchange water: 1, 400 parts or more of the above components were dispersed in a round stainless steel flask using a homogenizer (Ultra Turrax T50: manufactured by IKA) for 20 minutes, and then dispersed with a pressure discharge homogenizer. The average particle size was 365 nm. A release agent particle dispersion (1) in which certain wax particles were dispersed was prepared.

<Preparation of release agent particle dispersion (2)>
As the mold release agent, the mold release agent particle dispersion (1) except that the mold release agent (2): Microcrystalline wax (Hi-Mic-1070, melting temperature: 80 ° C.) manufactured by Nippon Seiwa Co., Ltd. was used. Similarly, a release agent particle dispersion (2) was obtained.

<Preparation of release agent particle dispersion (3)>
As the mold release agent, the mold release agent (3): polyethylene mold wax (PW850, melting temperature: 105 ° C.) manufactured by Toyo Petlite Co., Ltd. was used, and the mold release was performed in the same manner as the mold release agent particle dispersion (1). An agent particle dispersion (3) was obtained.

<Preparation of release agent particle dispersion (4)>
The release agent (4): Paraffin wax (F125, melting temperature: 52 ° C.) manufactured by Nippon Seiwa Co., Ltd. was used as the release agent in the same manner as the release agent particle dispersion (1). A mold particle dispersion (4) was obtained.

<Preparation of release agent particle dispersion (5)>
As the release agent, release agent (5): Nippon Seiwa Co., Ltd. paraffin wax (F115, melting temperature: 48 ° C.) was used except that release agent particle dispersion (1) was used. A mold particle dispersion (5) was obtained.

<Preparation of colorant particle dispersion>
Carbon black (Mogal L: Cabot): 50 parts Nonionic surfactant (Nonipol 400: Sanyo Chemical Co., Ltd.): 4 parts Ion-exchanged water: 210 parts The above ingredients are mixed and homogenizer ( Ultra-Turrax T50: made by IKA) for 20 minutes, and then dispersed with an optimizer to prepare a colorant dispersant in which colorant (carbon black) particles having an average particle size of 285 nm are dispersed. did.

<Preparation of toner (1) for developing electrostatic image>
The resin particle dispersion (1) and the resin fine particle dispersion (2) are mixed at a solid content ratio of 8: 2, and the mixed resin particle dispersion: 100 parts, the colorant particle dispersion: 10 parts, , Release agent particle dispersion (1): 5 parts, release agent particle dispersion (2): 5 parts, polyaluminum hydroxide (Pho2S manufactured by Asada Chemical Industries, Ltd.): 2 parts, sulfuric acid Aluminum (manufactured by Asada Chemical Co., Ltd.): 2 parts and ion-exchanged water: 600 parts were mixed and dispersed in a round stainless steel flask using a homogenizer (Ultra Turrax T50: manufactured by IKA). Then, it heated to 45 degreeC, stirring the inside of a flask in the oil bath for heating. After holding at 45 ° C. for 60 minutes, the temperature of the heating oil bath was raised and held at 55 ° C. for 2 hours. When the size of the aggregated particles (1) in this slurry was measured, D50v was 6.3 μm. Thereafter, 20 parts of the resin particle dispersion (1) was added to the dispersion containing the aggregated particles (1), and then the temperature of the heating oil bath was raised to 60 ° C. and held for 30 minutes. After adding 1N sodium hydroxide to the dispersion containing the agglomerated particles and adjusting the pH of the system to 8.0, the stainless steel flask was sealed, and heated to 92 ° C. while continuing stirring using a magnetic seal. For 90 minutes. After cooling with ice water, the toner particles were filtered off, washed 5 times with ion exchange water at 25 ° C., and then freeze-dried to obtain toner mother particles (1). The toner particles (1) had a D50v of 6.8 μm and a shape factor of 126.
Toner mother particles (1): 100 parts and external additive (Nippon Aerosil Co., Ltd., hydrophobic silica: RX50 0.5 part, Nippon Aerosil Co., Ltd., hydrophobic silica: R972 1.2 parts) Were blended for 15 minutes at a peripheral speed of 20 m / s using a Henschel mixer, and then coarse particles were removed using a sieve of 45 μm mesh to obtain toner (1).

<Preparation of toner (2) for developing electrostatic image>
A toner (2) was obtained in the same manner as the toner (1) except that the solid content ratio of the resin particle dispersion (1) and the resin particle dispersion (2) was changed to 9: 1.

<Preparation of toner for developing electrostatic image (3)>
Toner (except that the solid content ratio of the resin particle dispersion (1) and the resin particle dispersion (2) was changed to 9.5: 0.5 and the amount of polyaluminum hydroxide was changed to 2.5 parts. Toner (3) was obtained in the same manner as 1).

<Preparation of toner (4) for developing electrostatic image>
Toner (4) was obtained in the same manner as toner (1) except that the ratio of the solid content of resin particle dispersion (1) and resin particle dispersion (2) was changed to 7: 3.

<Preparation of toner (5) for developing electrostatic image>
Toner (except that the solid content ratio of the resin particle dispersion (1) and the resin particle dispersion (2) was changed to 6.5: 3.5 and the amount of polyaluminum hydroxide was changed to 1.7 parts. Toner (5) was obtained in the same manner as 1).

<Preparation of toner (6) for developing electrostatic image>
The resin particles initially charged in the flask were changed to 7: 2: 1, respectively, using the resin particle dispersion (1), the resin particle dispersion (2), and the resin particle dispersion (4). The toner (6) is the same as the toner (1) except that the release agent particle dispersion is changed to 5 parts of the release agent dispersion (1) and 5 parts of the release agent dispersion (4). )

<Preparation of toner (7) for developing electrostatic image>
First, the resin fine particles charged into the flask were made into resin particles dispersion liquid (1), resin particle dispersion liquid (2), and resin particle dispersion liquid (4) with a solid content ratio of 6.5: 2: 1, respectively. .5, and the release agent dispersion liquid is the same as that of the toner (1) except that the release agent particle dispersion liquid (1): 5 parts and the release agent particle dispersion liquid (5): 5 parts. Thus, toner (7) was obtained.

<Preparation of toner (8) for developing electrostatic image>
First, the resin particles charged into the flask were changed to 7: 2: 1 respectively using the resin particle dispersion (1), the resin particle dispersion (2), and the resin particle dispersion (3). In the same manner as in the toner (1) except that the release agent particle dispersion was changed to 5 parts of the release agent particle dispersion (2) and 5 parts of the release agent particle dispersion (3). (8) was obtained.

<Preparation of toner for developing electrostatic image (9)>
First, the resin particles charged in the flask were made into resin particles dispersion liquid (1), resin particle dispersion liquid (2), and resin particle dispersion liquid (3) with a solid content ratio of 6.5: 2: 1, respectively. .5, and the release agent particle dispersion was changed to 5 parts for the release agent particle dispersion (2) and 5 parts for the release agent particle dispersion (3). Thus, toner (9) was obtained.

<Preparation of toner (10) for developing electrostatic image>
First, the resin particles charged into the flask were mixed with the resin particle dispersion (1), the resin particle dispersion (2), the resin particle dispersion (3), and the resin particle dispersion (4). A toner (10) was obtained in the same manner as the toner (1) except that the ratio was changed to 6: 2: 1: 1.

<Preparation of toner (11) for developing electrostatic image>
First, the resin particles charged into the flask were used as a resin particle dispersion (1), a resin particle dispersion (2), a resin particle dispersion (3), and a resin particle dispersion (4). The release agent particle dispersion was changed to 5.5: 2: 1.5: 1, respectively, and the release agent particle dispersion (2): 5 parts and the release agent particle dispersion (3): 5 parts. Toner (11) was obtained in the same manner as Toner (1) except for the change.

<Preparation of toner (12) for developing electrostatic image>
The solid content ratio of the resin particle dispersion (1) and the resin particle dispersion (2) was changed to 7: 3, the amount of aluminum sulfate was changed to 2.5 parts, and the release agent particle dispersion was released. Molding agent particle dispersion (1): Toner (12) was obtained in the same manner as toner (1) except that the amount was changed to 5 parts and release agent particle dispersion (3): 5 parts.

<Preparation of toner (13) for developing electrostatic image>
Toner (1) except that the solid content ratio of resin particle dispersion (1) and resin particle dispersion (2) was changed to 8.5: 1.5 and the amount of aluminum sulfate was changed to 1.8 parts. In the same manner as above, a toner (13) was obtained.

<Preparation of toner (14) for developing electrostatic image>
Instead of the resin particle dispersion (1) and the resin particle dispersion (2), the resin particle dispersion (5) and the resin particle dispersion (6) are used, and the solid content ratio is 1: 9. The toner (14) was obtained in the same manner as the toner (1) except that the resin particle dispersion (6) was used instead of the resin particle dispersion (1) to be added.

<Preparation of toner (15) for developing electrostatic image>
Toner (15) was obtained in the same manner as toner (1) except that the amount of resin particle dispersion (1) added to the dispersion containing aggregated particles (1) was changed to 10 parts.

<Preparation of toner (16) for developing electrostatic image>
Toner (16) was obtained in the same manner as toner (1) except that the amount of resin particle dispersion (1) added to the dispersion containing aggregated particles (1) was changed to 5 parts.

<Preparation of toner (17) for developing electrostatic image>
Toner (17) was obtained in the same manner as toner (1) except that the amount of resin particle dispersion (1) added to the dispersion containing aggregated particles (1) was changed to 30 parts.

<Preparation of toner (18) for developing electrostatic image>
The resin particle dispersion (1), the resin particle dispersion (2), and the resin particle dispersion (5) are mixed at a solid content ratio of 7: 2: 1, and this mixed resin particle dispersion: 100 Part, colorant particle dispersion: 10 parts, release agent particle dispersion (1): 10 parts, polyaluminum hydroxide: 2 parts, aluminum sulfate: 2 parts, ion-exchanged water: 600 parts Were mixed and dispersed in a round stainless steel flask using a homogenizer (Ultra Turrax T50: manufactured by IKA), and then heated to 45 ° C. while stirring the inside of the flask in a heating oil bath. After reaching 45 ° C., 1 part of liquid paraffin (manufactured by Wako Pure Chemical Industries, Ltd .: liquid paraffin (density (20 ° C.): 0.825 to 0.850 g / ml)) is added, and then kept at 45 ° C. for 60 minutes. After that, the temperature of the heating oil bath was raised and held at 50 ° C. for 1 hour. Thereafter, 20 parts of the resin particle dispersion (1) was added to the dispersion containing the aggregated particles (18), and then the temperature of the heating oil bath was raised to 60 ° C. and held for 30 minutes. After adding 1N sodium hydroxide to the dispersion containing the agglomerated particles and adjusting the pH of the system to 8.5, the stainless steel flask is sealed and heated to 88 ° C. while stirring with a magnetic seal. For 90 minutes. After cooling with ice water, the toner particles were separated by filtration, washed 5 times with ion exchange water at 25 ° C., and freeze-dried to obtain toner mother particles (18).
A toner (18) was obtained in the same manner as the toner (1) except that the toner base particles (18) were used.

<Preparation of toner (19) for developing electrostatic image>
Release agent particle dispersion (1): 5 parts and release agent particle dispersion (2): Instead of 5 parts, release agent particle dispersion (1): 4 parts and release agent particle dispersion (2 ): Toner (except that 5 parts and 2 parts of release agent particle dispersion (3) were used, and 4.2 parts of aluminum sulfate was used instead of 2 parts of polyaluminum hydroxide and 2 parts of aluminum sulfate. In the same manner as in 1), toner (19) was obtained.

<Preparation of toner (20) for developing electrostatic image>
First, the resin fine particles charged into the flask were changed to 7: 2: 1 using a resin particle dispersion (1), a resin fine particle dispersion (2), and a resin fine particle dispersion (4), respectively. Toner (20) In the same manner as toner (1) except that aluminum hydroxide: 2 parts and aluminum sulfate: 2 parts were used instead of polyaluminum hydroxide: 1.8 parts and aluminum sulfate: 1.8 parts. Got.

<Preparation of toner (21) for developing electrostatic image>
Using resin particle dispersion (2), resin particle dispersion (3), and resin particle dispersion (4) as the resin particles initially charged in the flask, the solid content ratio was changed to 2: 5: 4, respectively. In place of 2 parts of polyaluminum hydroxide and 2 parts of aluminum sulfate, 2.2 parts of polyaluminum hydroxide and 2.2 parts of aluminum sulfate were used. A toner (21) was obtained in the same manner as the toner (1) except that the resin particle dispersion (3) was used instead.

<Preparation of toner (22) for developing electrostatic image>
First, the resin particles charged in the flask were changed to a ratio of 2: 8 for the solid content using the resin particle dispersion (2) and the resin particle dispersion (4). Agent particle dispersion (1): Toner (22) was obtained in the same manner as toner (1), except that the ratio was changed to 5 parts and release agent particle dispersion (5): 5 parts.

<Preparation of toner for developing electrostatic image (23)>
First, the resin particles charged in the flask were changed to a ratio of 2: 8 for the solid content using the resin particle dispersion (2) and the resin particle dispersion (3), and the release agent particle dispersion was released from the mold. Agent particle dispersion (1): Toner (23) was obtained in the same manner as toner (1), except that the ratio was changed to 5 parts and release agent particle dispersion (3): 5 parts.

<Preparation of toner (24) for developing electrostatic image>
Toner (24) was obtained in the same manner as toner (1) except that the release agent particle dispersion was changed to 10 parts of release agent particle dispersion (1).

<Preparation of toner (25) for developing electrostatic image>
Toner (25) was obtained in the same manner as toner (1) except that the release agent particle dispersion was changed to 10 parts of release agent particle dispersion (3).

<Preparation of toner (26) for developing electrostatic image>
Toner (26) is the same as toner (1) except that the release agent particle dispersion is changed to 3 parts of release agent particle dispersion (2) and 10 parts of release agent particle dispersion (3). )

<Preparation of toner for developing electrostatic image (27)>
Toner (27) is the same as toner (1) except that the release agent particle dispersion is changed to 8 parts release agent particle dispersion (1) and 6 parts release agent particle dispersion (5). )

<Preparation of developer>
[Production of carrier]
Ferrite particles (volume average particle diameter: 35 μm): 100 parts Toluene: 14 parts Perfluoroacrylate copolymer (critical surface tension: 24 dyn / cm): 1.6 parts Carbon black (trade name: VXC-72 , Manufactured by Cabot Corporation, volume resistivity: 100 Ωcm or less): 0.12 parts, crosslinked melamine resin particles (average particle size: 0.3 μm, toluene insoluble): 0.3 parts First, carbon is added to the perfluoroacrylate copolymer. Black was diluted in toluene and dispersed with a sand mill. Next, each of the above components other than the ferrite particles was dispersed for 10 minutes with a stirrer to prepare a coating layer forming solution. Next, the coating layer forming solution and the ferrite particles are put in a vacuum degassing kneader and stirred at a temperature of 60 ° C. for 30 minutes, and then the pressure is reduced and toluene is distilled off to form a resin coating layer. Got a career.

(Development of developer)
36 parts of the toner and 414 parts of the carrier were put in a 2 liter V blender, stirred for 20 minutes, and then sieved at 212 μm to prepare a developer.

(Evaluation)
<Evaluation 1>
“Apeos Port-IV C5580 (manufactured by Fuji Xerox Co., Ltd.)” modified so that an image can be output at a speed of 6 seconds per sheet of Lonston color paper (basis weight 157 g / m ² ) was used. The developer obtained in each example was filled in the developer of this Apeos Port-IV modified machine, 10 sheets of OS-coated paper were set, and left in an environmental room controlled at a temperature of 22 ° C. and a humidity of 45% for one day and night. After that, in an environment where the temperature is 22 ° C. and the humidity is 45%, the output in which a solid image and a line image are mixed in one sheet and the output of a blank sheet without an image are alternately repeated 50 sheets (25 images, 25 blank sheets). ) And the presence or absence of paper smudges due to image scattering and offset was confirmed visually and with a 50 × magnifier. The evaluation criteria are as follows.

[Spattering]
A: High quality output images were obtained with no scattering or offset-like stains.
B: When confirmed with a magnifying glass, it is at a level where some scattering and offset-like dirt are observed.
C: Even though the naked eye scatters around the line image and can discriminate offset stains, it is at a level where there is no problem in actual use.
D: Scattering and offset stains are remarkable in both the line image and the solid image, and this level is not suitable for actual use.

〔offset〕
A: Paper contamination due to offset is not seen, and a high-quality output image is obtained.
B: When confirmed with a magnifying glass, it is a level at which the toner offset in a spot shape is slightly seen.
C: Although the offset stain is slightly seen in the line image with the naked eye, it is at a level where there is no problem in actual use.
D: The offset of the line image and the solid image can be confirmed clearly even on the white paper, and is a level not suitable for actual use.

(Image intensity)
The solid image portion is lightly folded so that the image side is on the inside, and then a metal roll having a weight of 860 g and a diameter of 76 mm is rolled and passed through it at a speed of 150 mm / second to crease the image portion. After opening, the image bent portion and the unfolded portion were lightly rubbed with gauze, and the image defect state was confirmed with a 50 × magnifier.
-Evaluation criteria-
A: The image defect width after folding is less than 0.2 mm, and there is no change in the unfolded portion.
B: The image defect width after folding is 0.2 mm or more and less than 0.4 mm, and there is no change in the unfolded portion.
C: The image defect width after bending is 0.5 mm or more and less than 0.7 mm, or some image defect is also seen in the unfolded part.
D: The image defect width after bending is 0.7 mm or more, or a noticeable image defect is also observed in the unfolded part.

<Evaluation 2>
Scattering and offset were evaluated in the same manner as in Evaluation 1 except that the paper was mirror-coated platinum (basis weight 174 g / m ² ) and the experimental environment was at a temperature of 8 ° C. and a humidity of 13%. The evaluation method, judgment criteria, and the like are the same as those for evaluation 1.

<Evaluation 3>
A cartridge of Apeos Port-IV C5580 filled with toner was dropped 50 times from a height of 5 cm onto a test bench in the vertical direction with the shutter port on the bottom, and then left in a chamber at a temperature of 45 ° C. and a humidity of 75%. Let stand for hours. Thereafter, the cartridge was taken out, shaken in the horizontal direction 20 times while being held in the horizontal direction by hand, and then installed in the Apeos Port-IV C5580. 500 sheets of C2r paper (basis weight 70 g / m ² ) were set on the Apeos Port-IV, and the Apeos Port-IV C5580 was left in an environmental room controlled at a temperature of 22 ° C. and a humidity of 45% for one day and night. Thereafter, 500 sheets of halftone images having an image density of 25% on the front surface of the paper were continuously output in an environment of a temperature of 22 ° C. and a humidity of 45%. The image forming apparatus during output was abnormal, the inside of the image forming apparatus after output was observed, and the output image was observed for evaluation. The evaluation criteria are as follows.

[Storage test]
A: There is no abnormal operation during image formation, no abnormality in the image forming apparatus after image formation, no abnormality in the output image, and it is a level that enables stable image formation.
B: There is no abnormal operation during image formation and no abnormality in the output image, but when the inside of the image forming apparatus is observed after the image formation, the toner is slightly stained.
C: No abnormal operation at the time of image formation, but a level where remarkable toner stains are observed when the inside of the image forming apparatus is observed after image formation, or streaky stains or omissions are occasionally (less than 5%) in the output image. It is a level that can be seen.
D: Level at which the evaluation was interrupted due to the occurrence of abnormal noise during image formation, level at which streaks or omissions are seen at a high frequency (exceeding 5%) in the output image, or toner blowout contamination outside the image forming apparatus It is a level where can be seen.

Claims (10)

In the dynamic viscoelastic rheometer viscoelasticity measurement, it has a temperature T1 at which tan δ has a maximum value in the range of 50 ° C. or higher and 90 ° C. or lower,
Tan δ at T1 is 2.5 or more and 3 or less,
In a DSC curve measured by a differential scanning calorimeter, a plurality of local maximum points are shown when the temperature is lowered, at least one of the local maximum points is in a lower temperature region than T1, and at least one of the local maximum points is from T1. Also exists in the high temperature region,
An electrostatic charge image developing toner having a second maximum value of tan δ in the range from 90 ° C. to 140 ° C. and lower, wherein the value of tan δ in the second maximum value is 1.4 to 1.8. The electrostatic image developing toner according to claim 1, comprising a binder resin and a release agent, wherein the release agent exposed on the toner surface is 40 area% or less. The electrostatic charge image developing toner according to claim 2 , wherein the binder resin contains a styrene-acrylic resin. The toner for developing an electrostatic charge image according to any one of claims 1 to 3 , comprising two or more release agents having different melting temperatures. An electrostatic charge image developer comprising the electrostatic charge image developing toner according to any one of claims 1 to 4 and a carrier. A toner cartridge which is detachable from an image forming apparatus and contains the electrostatic image developing toner according to claim 1 . A developer cartridge containing the electrostatic charge image developer according to claim 5 . A process cartridge comprising a developer holder that contains the electrostatic image developer according to claim 5 and that holds and conveys the electrostatic image developer. An image carrier,
Charging means for charging the image carrier;
Exposure means for exposing the charged image carrier to form an electrostatic latent image on the surface of the image carrier;
Developing means for developing the electrostatic latent image with a developer containing toner to form a toner image;
Transfer means for transferring the toner image from the image carrier to the surface of the transfer target;
Fixing means for fixing the toner image transferred to the surface of the transfer target,
The developer is the electrostatic image developing toner according to any one of claims 1 to 4 , or the electrostatic image developer according to claim 5 .
Image forming apparatus. A latent image forming step of forming an electrostatic latent image on the surface of the image carrier;
A development step of developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner to form a toner image;
A transfer step of transferring the toner image onto the surface of the transfer target;
Fixing a toner image transferred to the surface of the transfer target,
The toner for electrostatic image development according to any one of claims 1 to 4 or the electrostatic image developer according to claim 5 is used as the developer.
Image forming method.