JP5531697B2 - Electrostatic image developing toner, electrostatic image developer, toner 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 process cartridge, an image forming apparatus, and an image forming method.
About.

  A method of visualizing image information through an electrostatic latent image (electrostatic image) such as electrophotography is currently used in various fields. Conventionally, in electrophotography, an electrostatic image is formed on a photosensitive member or electrostatic recording member using various means, and particles called toner are attached to the electrostatic image to develop the electrostatic image. A method is generally used in which a toner image (development image) is visualized through a plurality of steps of transferring the toner image onto the surface of a transfer medium and fixing it by heating or the like.

  As conventional toners and developers, toners and developers described in Patent Documents 1 to 7 are known. Patent Document 1 discloses a developer comprising resin particles having a softening point higher than that of a binder resin of toner base particles and a small particle diameter, and a carrier coated with a resin layer having the same charging order as that of the binder resin. . Patent Document 2 contains resin particles obtained by removing a solvent from a dispersion obtained by dispersing or dissolving a toner component containing a toner binder comprising a modified polyester in an organic solvent in an aqueous solvent. Disclosed is a toner. Patent Document 3 discloses a suspension obtained by externally adding resin particles having a reverse polarity of 0.01 to 1.0 μm and a sphericity of 0.9 to 1.0 with respect to a toner and inorganic particles having a smaller particle diameter than the resin particles. A polymerized toner is disclosed. Patent Document 4 discloses a toner in which the residual ratio of resin particles remaining on the surface of the toner particles is 2.8% by weight or less based on the toner particles in the modified polyester toner produced by the dissolution suspension method together with the resin particles. . Patent Document 5 discloses a toner in which resin particles having a glass transition point of 50 to 90 ° C. are present on the toner particle surface in a range of a coverage of 1 to 90%. In Patent Document 6, free mother particles to which no external additive (silica) is attached are 15% by weight or less, and the circularity of micro mother particles of 1.5 to 2.5 μm is 0.85 to 0.95. A toner is disclosed. Patent Document 7 discloses a developer comprising a toner having a large external additive having a shape factor of 100 to 130 and a particle size of 100 to 300 nm, and a carrier having a conductive powder-containing resin coating layer having a shape factor of 100 to 120. Disclose.

JP-A-8-328294 JP 2003-140391 A JP-A-5-313416 JP 2003-140381 A JP 2003-202701 A JP 2002-236390 A JP 2008-0776648 A

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

It has been found that the above problems can be solved by the following means.
<1> having colored particles containing at least a colorant and a binder resin, on the surface of the colored particles, inorganic particles, and resin particles comprising at least one composition contained in the binder resin; An electrostatic charge image developing toner, wherein the absolute value of the complex elastic modulus of the resin particles is smaller than the absolute value of the complex elastic modulus of the colored particles,
<2> The electrostatic image developing toner according to <1>, wherein at least one of the inorganic particles has a volume average particle diameter of 100 to 500 nm.
<3> The electrostatic charge image developing toner according to <1> or <2>, wherein the loss coefficient tan δ (G ″ / G ′) at 110 ° C. is 1.6 or less.
<4> The electrostatic charge image developing toner according to any one of <1> to <3>, wherein the resin particles have a volume average particle diameter of 100 to 5,000 nm.
<5> The electrostatic image developing toner according to any one of <1> to <4>, wherein 0.1 to 6% by weight of the resin particles are externally added to the colored particles.
<6> The electrostatic charge image developer comprising the toner for developing an electrostatic charge image according to any one of <1> to <5> and a carrier,
<7> The electrostatic charge image developer according to <6>, wherein the carrier is a carrier containing a core material in which magnetic powder is dispersed in a binder resin.
<8> A toner cartridge comprising at least toner and detachable from an image forming apparatus, wherein the toner is the electrostatic image developing toner according to any one of <1> to <5>. ,
<9> A process cartridge comprising at least a developer holder, detachably attached to the image forming apparatus, and containing the electrostatic charge image developer according to <6> or <7>,
<10> At least a photosensitive member, a charging unit that uniformly charges the photosensitive member, an electrostatic latent image forming unit that exposes the charged photosensitive member to form an electrostatic latent image, and the photosensitive member A developing unit that develops the electrostatic image formed on the photosensitive member as a toner image with a developer containing toner, a transfer unit that transfers the toner image formed on the photosensitive member onto the transfer target, and the transfer target Fixing means for fixing the toner image transferred thereon, wherein the fixing means is a fixing device having a surface pressure of 0.02 MPa to 0.2 MPa, and the toner is any one of <1> to <5> An image forming apparatus comprising: the electrostatic charge image developing toner according to 1 or the electrostatic charge image developer according to <6> or <7> as the developer;
<11> A charging step for uniformly charging the photoconductor, an electrostatic latent image forming step for exposing the charged photoconductor to form an electrostatic latent image, and the static image formed on the photoconductor A developing process for developing a charge image as a toner image with a developer containing toner, a transferring process for transferring a toner image formed on the photoreceptor onto a transfer target, and a toner transferred on the transfer target A fixing step for fixing an image, wherein the fixing step is a step of fixing at a surface pressure of 0.02 MPa to 0.2 MPa, and the toner is described in any one of <1> to <5>. An image forming method comprising: an electrostatic image developing toner; or the electrostatic image developer according to <6> or <7> as the developer.

By the means described in <1> above, when the absolute value of the complex elastic modulus of the resin particles is not smaller than the absolute value of the complex elastic modulus of the colored particles, it is stable when used in the image forming apparatus. An electrostatic charge image developing toner having low temperature fixability is provided.
Compared to the case where at least one kind of inorganic particles is not 100 to 500 nm in volume average particle diameter by means described in <2> above, excellent storage stability and stable low-temperature fixability when used in an image forming apparatus. And a toner for developing an electrostatic image capable of satisfying both at a high level.
By the means described in <3> above, a low gloss image can be obtained when used in the image forming apparatus as compared with the case where the loss coefficient tan δ (G ″ / G ′) at 110 ° C. exceeds 1.6. An electrostatic charge image developing toner is provided.
By the means described in <4> above, an electrostatic charge image that is more stable and has excellent low-temperature fixability when used in an image forming apparatus than when the volume average particle diameter of the resin particles is not 100 to 5,000 nm. A developing toner is provided.
When the resin particles are used in the image forming apparatus by the means described in <5> above, compared with the case where the resin particles are externally added to the colored particles in an amount of less than 0.1% by weight or more than 6% by weight. An electrostatic charge image developing toner excellent in stable low-temperature fixability and image gloss uniformity is provided.
When used in an image forming apparatus by means of the above <6>, as compared with the case where the toner for developing an electrostatic charge image described in any one of <1> to <5> and a carrier are not included. An electrostatic charge image developer having stable low-temperature fixability is provided.
Compared to the case where the carrier is not a carrier containing a core material in which magnetic powder is dispersed in a binder resin by the means described in <7> above, when used in an image forming apparatus, image density stability, and An electrostatic charge image developer excellent in image density uniformity is provided.
By means described in <8> above, the toner is more stable when used in an image forming apparatus than in the case where the toner is not the electrostatic charge image developing toner described in any one of <1> to <5>. A toner cartridge having low temperature fixability is provided.
By the means described in <9> above, stable low-temperature fixability when used in an image forming apparatus as compared with the case where the electrostatic image developer described in <6> or <7> is not contained. A process cartridge is provided.
By the means described in <10> above, the electrostatic charge image developing toner described in any one of <1> to <5> as a toner, or the electrostatic charge described in <6> or <7> as a developer. An image forming method having stable low-temperature fixability as compared with the case where no image developer is used is provided.
By the means described in <11> above, the electrostatic charge image developing toner described in any one of <1> to <5> as a toner, or the electrostatic charge described in <6> or <7> as a developer. An image forming apparatus having stable low-temperature fixability is provided as compared with the case where no image developer is used.

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

(1) Toner for developing an electrostatic image The toner for developing an electrostatic image of the present embodiment (hereinafter also referred to as toner) has colored particles containing at least a colorant and a binder resin. Externally adding inorganic particles and resin particles having at least one composition contained in the binder resin on the surface, the absolute value of the complex elastic modulus of the resin particles is the complex elasticity of the colored particles. It is characterized by being smaller than the absolute value of the rate. Hereinafter, this embodiment will be described in more detail. In addition, in the following description, the description of “A to B” representing a numerical range is synonymous with “A or more and B or less” unless otherwise specified, and means a numerical range including A and B as end points. .

The electrostatic charge image developing toner according to the present embodiment is presumed to exhibit the following effects.
When fixing a toner having an absolute value of complex elastic modulus (| G ^* |) of 10,000 or more with a fixing device having a surface pressure of 0.02 MPa or more and 0.2 MPa or less, an inorganic external additive, particularly a volume average particle diameter. Due to the effect as a spacer (hereinafter also referred to as the spacer effect) of an inorganic external additive (hereinafter also referred to as a large-diameter inorganic external additive) having a thickness of 100 nm or more and the recording medium and the recording medium The adhesion of the interface (hereinafter also referred to as the toner interface) tends to be physically hindered, and the strength of isolated images such as fine lines and dots may be reduced.
Further, when the external additive is buried in the toner surface by a mechanical external force, the toner surface becomes difficult to melt or deform, and further, adhesion of the toner interface is hindered. That is, the effect of reinforcing the surface of the toner by burying the external additive (hereinafter also referred to as filler effect) increases the melt viscosity as compared with that before burying the external additive. Adhesion is inhibited. For example, if the toner continues to be exposed to a mechanical external force by agitation in the developing machine, such as when output of an image of a small area continues, or when output of two or more colors continues, the external additive Is buried in the surface of the toner, and the fixing property is deteriorated. Therefore, if the temperature setting of the fixing device is matched with the initial fixing result after fixing several sheets after starting the image forming apparatus, a fixing failure is caused when the toner receives a mechanical external force for a long time. If the fixing device temperature is set in consideration of the fixability when subjected to mechanical external force for a long time, the image gloss in the initial state is set to the temperature setting of the fixing device. May be higher than when adjusted to the initial fixing result.
Of the inorganic external additives, the large-diameter inorganic external additive has a large spacer effect, and contributes to improvement in storage stability of the toner against heat. However, the large-diameter inorganic external additive may physically inhibit adhesion at the toner interface during fixing, and may also inhibit adhesion at the toner interface when buried in the toner surface. These become frequent as the process speed increases, and also when the amount of toner used on the rough paper per unit area is increased in order to form an image without uneven glossiness on the rough paper. Therefore, it is necessary to further improve the adhesion at the toner interface from the viewpoint of speeding up and generalization of the paper.

  On the other hand, when the inorganic external additive is detached from the surface of the colored particles and adheres to the surface of the carrier, the inorganic external additive generally has a higher volume resistance than the carrier. By interposing in the contact portion, the electrical resistance (hereinafter also referred to as macro resistance) in the carrier aggregate may increase. In particular, since the spacer effect is large in the case of a large-diameter inorganic external additive, the macro resistance of the carrier is likely to increase as compared with the case where an external additive having a thickness of less than 100 nm is used.

  The closer the carrier is to a true sphere or the smoother the surface, the more fluid the developer, the more stable the developer amount on the developer holder, and uneven density in the surface of the resulting image. For example, when the image forming apparatus is continuously operated as in the case of printing 5,000 sheets, the image density and image quality are stabilized even if time elapses. Further, since the bulk density of the developer is high, the controllability of the toner concentration in the developer by a magnetization sensor or the like is improved, and the image density and image quality are stabilized. However, when free inorganic external additives adhere to such a spherical and smooth carrier, the existence probability of the inorganic external additive at the contact portion between a plurality of carriers increases, so that the macro of the carrier Resistance rises.

The toner for developing an electrostatic charge image according to this embodiment is obtained by externally adding resin particles having at least one composition contained in a binder resin, and the absolute value of the complex elastic modulus of the resin particles is that of the colored particles. The toner is characterized by being smaller than the absolute value of the complex elastic modulus.
Since the resin particles have a lower complex elastic modulus than the colored particles, the melt viscosity at the time of fixing is lower than that of the colored particles, and the effect of assisting the fixing (hereinafter also referred to as a fixing assist effect) is exhibited. By externally adding such resin particles, since inorganic particles and resin particles are mixed on the surface of the colored particles, inhibition of adhesion at the toner interface during fixing due to the spacer effect of the inorganic particles is suppressed. Further, even when the external additive is buried, the effect of locally assisting the adhesion between the colored particles that have become difficult to adhere (hereinafter also referred to as an adhesion assisting effect) is exerted to suppress deterioration of the fixing property. In this way, when subjected to a mechanical external force that causes the external additive to be buried, resin particles having a lower complex elastic modulus than the colored particles are easily deformed, so the surface of the colored particles is locally covered. /Adhere to. In addition, external additives released from the toner surface, especially free large-diameter inorganic external additives, can be easily captured on the surface of the resin particles, so that the migration of the external additive to the carrier can be suppressed, or the large additive adhered to the carrier surface. Re-supplement the diameter inorganic external additive.
Since the resin particles are composed of at least one composition contained in the binder resin, since there is no change in the refractive index, the influence on the color gamut and image density is small, and the influence on charging is also small. In addition, since Tg is equivalent to at least one kind of resin contained in the binder resin, there is little influence in terms of heat storage and fixability, and since the affinity with colored particles is high, there is an adhesion assisting effect. improves.

(Colored particles)
In the present embodiment, the colored particles contain at least a colorant and a binder resin. The colored particles may contain other components such as a release agent in addition to these components.

<Binder resin>
In the present embodiment, the binder resin is not particularly limited, but includes a polyester resin from the viewpoint of low-temperature fixability, image strength, and offset durability against vinyl chloride (hereinafter also referred to as vinyl chloride offset resistance). It is more preferable that it contains an amorphous polyester resin. The polyester resin is synthesized, for example, mainly by condensation polymerization of polyvalent carboxylic acids and polyhydric alcohols.

  Examples of the polyvalent carboxylic acid include terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, naphthalenedicarboxylic acid, and the like; maleic anhydride, fumaric acid, succinic acid, Aliphatic carboxylic acids such as alkenyl succinic anhydride and adipic acid; and alicyclic carboxylic acids such as cyclohexanedicarboxylic acid. These polyvalent carboxylic acids may be used alone or in combination of two or more. Among these polyvalent carboxylic acids, it is preferable to use an aromatic carboxylic acid. For the purpose of ensuring good fixability, it is preferable to use a trivalent or higher carboxylic acid (trimellitic acid or its acid anhydride) together with a dicarboxylic acid in order to form a crosslinked structure or a branched structure.

Examples of the polyhydric alcohol include aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentylglycol, and glycerin; cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol And alicyclic diols such as A; aromatic diols such as ethylene oxide adduct of bisphenol A and propylene oxide adduct of bisphenol A. These polyhydric alcohols may be used alone or in combination of two or more.
Among these polyhydric alcohols, aromatic diols and alicyclic diols are preferable, and among these, aromatic diols are more preferable. In addition, in order to secure better fixability, a trihydric or higher polyhydric alcohol (for example, glycerin, trimethylolpropane, pentaerythritol, etc.) is used in combination with a diol in order to take a crosslinked structure or a branched structure. Also good.

  The glass transition temperature (hereinafter sometimes abbreviated as “Tg”) of the amorphous polyester resin is preferably 50 to 80 ° C., more preferably 50 to 70 ° C. When Tg is 80 ° C. or lower, the low-temperature fixability is excellent. Further, when the Tg is 50 ° C. or higher, the heat resistant storage stability is excellent, and the fixed image storage stability is excellent.

  In this embodiment, the content of the amorphous polyester resin in the colored particles is preferably 50 to 96% by weight, more preferably 60 to 94% by weight, and more preferably 65 to 92% by weight, with the total weight of the colored particles being 100% by weight. % Is more preferable. When the content of the amorphous polyester resin is within the above range, the vinyl chloride offset resistance is good, and when the resin particles are amorphous polyester resin particles, the compatibility is improved and the large-diameter inorganic external additive is added. Inhibition of adhesion during fixing by the agent is suppressed.

  The acid value of the amorphous polyester resin is preferably 5 to 25 mgKOH / g. If the acid value is 5 mgKOH / g or more, the toner has good affinity for paper and good chargeability. In addition, when the toner is produced by the emulsion aggregation method described later, it is easy to produce emulsion particles, and it is suppressed that the speed of aggregation in the aggregation process of the emulsion aggregation method and the speed of shape change in the fusion process are increased. Easy to control grain size and shape. In addition, if the acid value of the amorphous polyester resin is 25 mgKOH / g or less, the environmental dependency of charging is not adversely affected. In addition, a decrease in the aggregation rate in the aggregation step and the change rate of the shape in the fusing step in the production of toner by the emulsion aggregation method can be suppressed, and productivity does not decrease. The acid value of the amorphous polyester resin is more preferably 6 to 23 mgKOH / g.

  The weight average molecular weight (Mw) of the amorphous polyester resin is preferably 5,000 to 1,000,000, and more preferably 7,000 to 500,000. The number average molecular weight (Mn) of the amorphous polyester resin is preferably 2,000 to 100,000. Moreover, 1.5-100 are preferable and, as for molecular weight distribution Mw / Mn, 2-60 are more preferable. It is preferable that the weight average molecular weight, number average molecular weight, and molecular weight distribution of the amorphous polyester resin are within the above ranges because excellent fixed image strength can be obtained without impairing the low-temperature fixability.

  In this embodiment, the weight average molecular weight and the number average molecular weight of the polyester resin are measured and calculated by GPC (Gel Permeation Chromatography). Specifically, GPC uses HLC-8120 manufactured by Tosoh Corporation, the column uses TSKgel SuperHM-M (15 cm) manufactured by Tosoh Corporation, and the polyester resin is dissolved in a THF solvent and measured. Next, the molecular weight of the polyester resin is calculated using a molecular weight calibration curve created with a monodisperse polystyrene standard sample.

  In the present embodiment, the colored particles may contain a crystalline polyester resin. The crystalline polyester resin is compatible with the amorphous polyester resin when melted to lower the toner viscosity, so that a toner having better low-temperature fixability can be obtained. Further, among the crystalline polyester resins, aromatic crystalline polyester resins are generally higher than the melting temperature range described later, and therefore when the crystalline polyester resin is included, the aromatic crystalline polyester resin is more preferably an aliphatic crystalline polyester resin. preferable.

  In the present embodiment, the content of the crystalline polyester resin in the colored particles is preferably 2 to 30% by weight, more preferably 4 to 25% by weight, with the total weight of the colored particles being 100% by weight. When the content is 2% by weight or more, the low-temperature fixability is improved because the amorphous polyester resin has a low viscosity at the time of melting. On the other hand, if the amount is 30% by weight or less, the deterioration of the charging property of the toner due to the presence of the crystalline polyester resin is prevented, and a high image strength after fixing on the recording medium (transfer medium) is easily obtained.

  The melting temperature of the crystalline polyester resin is preferably in the range of 50 to 90 ° C, more preferably in the range of 55 to 90 ° C, and further preferably in the range of 60 to 90 ° C. When the melting temperature is 50 ° C. or higher, the toner storage stability and the toner image storage stability after fixing are excellent. Moreover, if it is 90 degrees C or less, low temperature fixability will improve.

  In the present embodiment, the “crystalline polyester resin” is not a stepwise change in endothermic amount in differential scanning calorimetry (hereinafter sometimes abbreviated as “DSC”). It has a good endothermic peak. The crystalline polyester resin is a polymer obtained by copolymerizing other components with respect to the main chain. When the other components are less than 50% by weight, the copolymer is also called crystalline polyester.

  The crystalline polyester resin is synthesized from an acid (dicarboxylic acid) component and an alcohol (diol) component. In the following, the “acid-derived structural unit” refers to a polyester resin before the synthesis of the polyester resin. Refers to a structural unit that was an acid component, and “alcohol-derived structural component” refers to a structural unit that was an alcohol component before the synthesis of the polyester resin.

Examples of the acid component serving as the acid-derived structural unit include various dicarboxylic acids, and linear aliphatic dicarboxylic acids are preferable.
Examples of the acidic component include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1 , 11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, etc. Examples thereof include, but are not limited to, lower alkyl esters and acid anhydrides. Among these, adipic acid, sebacic acid, and 1,10-decanedicarboxylic acid are preferable in consideration of availability.
The crystalline polyester resin may contain structural units such as a structural unit derived from a dicarboxylic acid having a double bond and a structural unit derived from a dicarboxylic acid having a sulfonic acid group as an acid-derived structural unit.

  As alcohol which becomes a structural unit derived from alcohol, aliphatic diol is preferable, for example, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1 , 7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-dodecanediol, 1,12-undecanediol, 1,13-tridecanediol, , 14-tetradecanediol, 1,18-octadecanediol, 1,20-eicosanediol, and the like, but are not limited thereto. Among these, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferable in consideration of cost.

  The molecular weight (weight average molecular weight; Mw) of the crystalline polyester resin is preferably 8,000 to 40,000, from the viewpoints of resin manufacturability, resin dispersion during toner production, and compatibility during melting. 30,000 to 30,000 is more preferable. If the weight average molecular weight is 8,000 or more, a decrease in resistance of the crystalline polyester resin is suppressed, so that a decrease in chargeability is prevented. On the other hand, if it is 40,000 or less, the cost of resin synthesis is suppressed, and a decrease in meltability is prevented, so that the fixability is not adversely affected.

  There is no restriction | limiting in particular as a manufacturing method of a polyester resin, The polymerization method of the well-known polyester resin which makes an acid component and an alcohol component react is illustrated. For example, the polyester resin is produced by properly using direct polycondensation, transesterification method, and the like depending on the types of the acid component and the alcohol component. The molar ratio (acid component / alcohol component) at the time of reacting the acid component and the alcohol component varies depending on the reaction conditions and the like, and thus cannot be generally specified. However, in order to increase the molecular weight, the molar ratio ( The acid content / alcohol component) is preferably 1 / 0.95 to 1 / 1.05.

  Catalysts used in the production of the polyester resin include alkali metal compounds such as sodium and lithium; alkaline earth metal compounds such as magnesium and calcium; metal compounds such as zinc, manganese, antimony, titanium, tin, zirconium and germanium; Examples thereof include phosphorous acid compounds; phosphoric acid compounds; and amine compounds.

  In addition to the polyester resin, other resins are also used as the binder resin. Other resins include ethylene resins such as polyethylene and polypropylene; styrene resins such as polystyrene and α-polymethylstyrene; (meth) acrylic resins such as polymethyl (meth) acrylate and poly (meth) acrylonitrile; polyamide resins , Polycarbonate resin, polyether resin and copolymer resins thereof.

  The content of the other resin in the colored particles is preferably 1.0 to 12% by weight, more preferably 2.0 to 11% by weight, with the total weight of the entire colored particles being 100% by weight, and 2.5 to 10% by weight is more preferred. When the content of other resins is within the above range, sufficient coloring power can be obtained without impairing the low-temperature fixability.

<Colorant>
The colored particles contain a colorant. The colorant may be a dye or a pigment, but a pigment is used from the viewpoint of light resistance and water resistance. Further, the colorant is not limited to a colored colorant, and includes a white colorant and a colorant having a metal color.
Examples of colorants include carbon black, aniline black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, and rose. Bengal, Quinacridone, Benzidine Yellow, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 185, C.I. I. Pigment red 238, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 74, C.I. I. Pigment blue 15: 1, C.I. I. A known pigment such as CI Pigment Blue 15: 3 is used.

In the toner for developing an electrostatic charge image of the exemplary embodiment, the content of the colorant is preferably 1 to 30 parts by weight with respect to 100 parts by weight of the binder resin.
It is also effective to use a surface-treated colorant or a pigment dispersant. By selecting the type of the colorant, yellow toner, magenta toner, cyan toner, black toner and the like are prepared.

<Release agent>
One embodiment of the colored particles includes colored particles containing a release agent. Examples of the release agent include paraffin wax such as low molecular weight polypropylene and low molecular weight polyethylene; silicone resin; rosins; rice wax; carnauba wax; 50-100 degreeC is preferable and, as for the melting temperature of these mold release agents, 60-95 degreeC is more preferable.
The content of the release agent in the colored particles is preferably 0.5 to 15% by weight, and more preferably 1.0 to 12% by weight. If the content of the release agent is 0.5% by weight or more, peeling failure particularly in the case of oilless fixing is prevented. If the content of the release agent is 15% by weight or less, deterioration of toner fluidity can be prevented, and image quality and image formation reliability can be maintained.

<Other additives>
In addition to the components as described above, various components such as an internal additive and a charge control agent may be added to the colored particles according to the present embodiment as necessary.
Examples of the internal additive include metals such as ferrite, magnetite, reduced iron, cobalt, nickel and manganese, alloys, and magnetic materials such as compounds containing these metals.
Examples of the charge control agent include quaternary ammonium salt compounds, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium, and triphenylmethane pigments.

(External additive)
In the toner for developing an electrostatic charge image of the exemplary embodiment, inorganic particles and resin particles having at least one composition contained in the binder resin are externally added to the surface of the colored particles.

<Inorganic particles>
In the present embodiment, the electrostatic image developing toner has inorganic particles (inorganic external additives) externally added to the surface of the colored particles.
Examples of the inorganic particles include silica particles, titanium oxide particles, alumina particles, cerium oxide particles, and the like, but silica particles are used because they have little influence on cost and color gamut. In particular, silica particles produced by the sol-gel method are preferable because of narrow particle size distribution and high sphericity. The inorganic particles may be subjected to various surface treatments. For example, those subjected to surface treatment with a silane coupling agent, a titanium coupling agent, silicone oil or the like are preferably used.

  In this embodiment, it is more preferable that at least one of the inorganic particles has a volume average particle diameter of 100 to 500 nm. In the present embodiment, inorganic particles having a particle size in the above range are referred to as large-diameter inorganic particles (large-diameter inorganic external additive). In the present embodiment, the volume average particle diameter of the large-diameter inorganic particles is more preferably 100 to 400 nm. When it is 100 nm or more, the spacer effect is sufficiently obtained, and the effect of improving the toner storage property is great. Moreover, when it is 500 nm or less, it adheres to the surface of the colored particles, and desorption / separation is suppressed.

  The addition amount of the large-diameter inorganic particles is preferably 0.1 to 10 parts by weight, more preferably 0.15 to 9 parts by weight, with respect to 100 parts by weight of the colored particles. More preferably, it is 8 parts by weight. When the addition amount of the large-diameter inorganic particles is 0.1 parts by weight or more with respect to 100 parts by weight of the colored particles, storage properties and toner fluidity are improved. In addition, when the amount is 10 parts by weight or less, the colored particles adhere without unevenness.

  In the present embodiment, two or more types of large-diameter inorganic particles having different volume average particle diameters may be used as external additives. Moreover, you may use together the inorganic particle (small-diameter inorganic particle) whose volume average particle diameter is less than 100 nm. That is, two types of inorganic particles that are different types of inorganic particles having different volume average particle diameters may be used, and inorganic particles of the same type that have different volume average particle sizes are used in combination. May be.

<Resin particles>
In the present embodiment, the resin particles externally added to the colored particles have at least one composition contained in the binder resin.
The absolute value of the complex elastic modulus of the resin particles is smaller than the absolute value of the complex elastic modulus of the colored particles. The resin particles having a viscosity lower than that of the colored particles assist the adhesion of the toner that is difficult to adhere at the toner interface due to the spacer effect of the inorganic external additive, and suppress the deterioration of the fixing property. In addition, since the absolute value of the complex elastic modulus is lower than that of the colored particles, it is easily deformed, and due to the filler effect of the external additive embedded in the toner surface by being locally coated / attached to the colored particle surface by mechanical external force. The effect of suppressing the deterioration of fixability by assisting the adhesion of the toner, which has become difficult to adhere at the toner interface, in a wider range is improved. Further, the released large-diameter inorganic external additive is captured and the transfer to the carrier is suppressed.

From the viewpoint of the adhesion assisting effect, the absolute value (| G ^* |) of the complex elastic modulus at 110 ° C. of the resin particles is preferably less than 10,000 Pa, more preferably 1,000 to 10,000 Pa, and more preferably 3,000 to 10 1,000 Pa is more preferable.

The absolute value (| G ^* |) (unit: Pa) of the complex elastic modulus is calculated by the following formula.
| G ^* | ² = (M ′) ² + (M ″) ²
Here, M ′ represents a storage elastic modulus and M ″ represents a loss elastic modulus.
The absolute value (| G ^* |) of the complex elastic modulus is obtained by, for example, using a rheometer (manufactured by Rheometric Scientific: ARES rheometer) and measuring the temperature rise using a parallel plate at a frequency of 1 Hz. Calculated.

The volume average particle diameter of the resin particles is preferably 100 to 5,000 nm, and more preferably 120 to 4,000 nm. When it is 100 nm or more, inhibition of fixing due to the spacer effect of the large-diameter inorganic external additive is suppressed, and an external additive released from the toner (hereinafter also referred to as a free external additive) is captured. When the thickness is 5,000 nm or less, it becomes difficult to form an agglomerate including toner due to a mechanical external force, and an adverse effect on image quality is suppressed. 100 to 1,000 nm is preferable from the viewpoint of fixing assistance effect, and 500 to 5,000 nm is preferable from the viewpoint of capturing free external additives.
When the diameter of the particles to be measured is 2 μm or more, the volume average particle diameter of the resin particles is measured and measured using a measuring device such as Coulter Multisizer II (manufactured by Beckman Coulter, Inc.). When the particle diameter is less than 2 μm, it is measured using a laser diffraction particle size distribution analyzer (LA-700: manufactured by Horiba, Ltd.).

  In this embodiment, the addition amount of the resin particles is preferably 0.1 to 6 parts by weight with respect to 100 parts by weight of the colored particles. When the value is within the above range, a sufficient fixing assist effect and an effect of capturing free external additives are obtained, and gloss unevenness of a fixed image is suppressed.

The resin particles are produced by emulsifying the produced resin and then drying. Examples of the emulsification method include a dissolution suspension method, a melt emulsification method, and a phase inversion emulsification method, but a melt emulsification method and a phase inversion emulsification method that are finally prepared in the form of dispersion in water are preferable. A phase inversion emulsification method in which emulsification is performed without adding a surfactant is preferred. The emulsification method will be described in detail in the emulsion aggregation method described later.
The drying method is not particularly limited and may be appropriately selected from known drying methods. However, in order to prepare particles without aggregation, a freeze vacuum drying method is preferable.

(Toner characteristics)
The toner for developing an electrostatic charge image according to this embodiment preferably has a shape factor SF1 of 115 to 140. The closer the toner shape is to a perfect sphere, the more advantageous in terms of developability and transferability, but in terms of cleaning properties, it may be inferior to an indeterminate shape. The shape factor SF1 of the toner is more preferably 120 to 138. When the toner has a shape in the above range, transfer efficiency and image density are improved, high-quality image formation is performed, and the cleaning property of the surface of the photosensitive member (image holding member) is enhanced.

Here, the shape factor SF1 is obtained by the following equation.
SF1 = (ML ² / A) × (π / 4) × 100
In the above formula, ML represents the absolute maximum length of the toner particles, and A represents the projected area of the toner particles.
SF1 is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image using an image analysis apparatus. For example, an optical microscope image of particles dispersed on the surface of a slide glass is transmitted through a video camera. It is calculated by taking in a Luzex image analyzer, obtaining the maximum length and projected area of 100 particles, calculating by the above formula, and determining the average value.

  Further, the volume average particle diameter of the toner for developing an electrostatic charge image according to the exemplary embodiment is preferably 3 to 9 μm, more preferably 3.1 to 8.5 μm, and further preferably 3.2 to 8 μm. When the volume average particle diameter is 3 μm or more, a decrease in toner fluidity is suppressed, and the chargeability of each particle is easily maintained. In addition, the charge distribution is not widened, preventing transfer to the background (non-image area), and the toner is less likely to spill from the developing machine. Further, when the volume average particle diameter of the toner is 3 μm or more, the cleaning property is improved. When the volume average particle diameter is 9 μm or less, a decrease in resolution is suppressed and sufficient image quality is obtained. The volume average particle diameter is measured with a measuring machine such as Coulter Multisizer II (manufactured by Beckman Coulter, Inc.).

The absolute value (| G ^* |) of the complex elastic modulus at 110 ° C. of the electrostatic image developing toner according to this embodiment is preferably 10,000 to 100,000 Pa, more preferably 15,000 to 60,000 Pa, and 20 , 50,000 to 50,000 Pa are more preferable. When the absolute value of the complex elastic modulus is 10,000 Pa or more, the image has a good low image gloss. Further, when the absolute value of the complex elastic modulus is 100,000 Pa or less, the low temperature fixability is excellent.

  The tan δ (G ″ / G ′) at 110 ° C. of the toner for developing an electrostatic charge image according to the exemplary embodiment is preferably 1.6 or less, more preferably 1.5 or less, and further preferably 1.4 or less. When G ″ / G ′) is 1.6 or less, a good low-gloss image can be obtained. Note that G ′ represents a storage elastic modulus, and G ″ represents a loss elastic modulus.

(Method for producing toner for developing electrostatic image)
A method for producing colored particles used in the method for producing a toner for developing an electrostatic charge image according to this embodiment will be described. The method for producing the colored particles according to the present embodiment is not particularly limited, and is produced by a dry method such as a kneading pulverization method or a wet method such as a melt suspension method, an emulsion aggregation method, or a dissolution suspension method. Especially, it is preferable to manufacture by an emulsion aggregation method.

The emulsion aggregation method is to prepare dispersions (emulsion, pigment dispersion, etc.) each containing components (binder resin, colorant, etc.) contained in the colored particles, and mix these dispersions into colored particles. In this method, the components contained are aggregated to form aggregated particles, and then the aggregated particles are heated to a melting point melting temperature or glass transition temperature or higher of the binder resin to thermally fuse the aggregated particles.
Emulsion aggregation is easier to produce colored particles with a smaller particle size and narrower particle size distribution than kneading and pulverization, which is a dry method, and melt suspension, dissolution suspension, etc., which are other wet methods. Easy to obtain colored particles. In addition, shape control is easier than in the melt suspension method, dissolution suspension method, and the like, and uniform amorphous colored particles are produced. Furthermore, it is possible to control the structure of the colored particles, such as film formation, and when a release agent or a crystalline polyester resin is contained, these surface exposures are suppressed, thereby preventing deterioration of chargeability and storage stability. The
In the emulsion aggregation method, aggregated particles are preferably prepared by adding a polyvalent metal salt as an aggregating agent. The polyvalent metal forms ionic crosslinks with terminal functional groups of the binder resin during the particle preparation process. To do. That is, the viscoelasticity of the colored particles is controlled by controlling the metal valence and the amount of the remaining metal element. Therefore, in contrast to resin particles without ionic crosslinking produced using a resin contained in a binder resin, colored particles containing ionic crosslinking produced using the same resin are inevitably more complex than resin particles. The absolute value of becomes higher.
Thus, it is preferable to use the emulsion aggregation method because desired resin particles and colored particles are produced by the same method.

Next, the manufacturing process of the emulsion aggregation method will be described in detail.
In the emulsion aggregation method, at least an emulsification step of emulsifying raw materials constituting colored particles to form resin particles (emulsion particles), an aggregation step of forming aggregates of the resin particles, and a fusion that fuses the aggregates Process. Hereinafter, an example of the manufacturing process of the colored particles by the emulsion aggregation method will be described for each process.

[Emulsification process]
Examples of the method for preparing the emulsion include a phase inversion emulsification method and a melt emulsification method.
In the phase inversion emulsification method, a resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, and a base is added to the organic continuous phase (Oil phase; O) to neutralize it. Thereafter, by introducing an aqueous medium (Water phase; W), the water in oil (W / O) system is changed to an oil in water (O / W) system, so that the resin present in the organic continuous phase Phase into a discontinuous phase. As a result, the resin is dispersed and stabilized in the form of particles in the aqueous medium, and an emulsion is prepared.
In the melt emulsification method, an emulsion is prepared by applying a shearing force to a solution in which an aqueous medium and a resin are mixed by a disperser. At that time, particles are formed by heating to lower the viscosity of the resin component. A dispersant may be used to stabilize the dispersed resin particles. Furthermore, when the resin is oily and has a relatively low solubility in water, the resin is dissolved in a solvent in which the resin is dissolved and dispersed in water together with a dispersant and a polymer electrolyte, and then heated or decompressed. You may produce the emulsified liquid which disperse | distributed the resin particle by evaporating a solvent.

  Examples of the disperser used for dispersion of the emulsion by the melt emulsification method include a homogenizer, a homomixer, a pressure kneader, an extruder, and a media disperser.

  Examples of the aqueous medium include water such as distilled water and ion-exchanged water; alcohols; however, it is preferable to use only water.

  Examples of the dispersant used in the emulsification step include water-soluble polymers such as polyvinyl alcohol, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, sodium polyacrylate, and sodium polymethacrylate; sodium dodecylbenzenesulfonate. Anionic surfactants such as sodium octadecyl sulfate, sodium oleate, sodium laurate, potassium stearate, cationic surfactants such as laurylamine acetate, stearylamine acetate, lauryltrimethylammonium chloride, lauryldimethylamine oxide, etc. Zwitterionic surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene Surfactants such as nonionic surfactants down alkylamines, and the like. Of these, anionic surfactants are used from the viewpoint of easy cleaning and environmental suitability.

  10-50 weight% is preferable and, as for content of the resin particle contained in the emulsified liquid in the said emulsification process, 20-40 weight% is more preferable. When the content is 10% by weight or more, the particle size distribution does not spread excessively. Further, if it is 50% by weight or less, uniform stirring can be performed, and colored particles having a narrow particle size distribution and uniform characteristics can be obtained.

  The volume average particle diameter of the resin particles is preferably in the range of 0.08 to 0.8 μm, more preferably 0.09 to 0.6 μm, and even more preferably 0.10 to 0.5 μm. If it is 0.08 μm or more, the resin particles tend to aggregate. Moreover, if it is 0.8 micrometer or less, since the particle size distribution of a colored particle is hard to spread and precipitation of an emulsified particle is suppressed, the preservability of an emulsified particle dispersion improves.

Before entering the agglomeration step described below, it is preferable to prepare a dispersion liquid in which a colorant, a release agent, or the like, which is a colored particle component other than the binder resin, is dispersed.
In addition to the method of preparing a dispersion corresponding to each component such as a binder resin and a colorant, for example, when preparing an emulsion of a certain component, other components may be added to the solvent to add two or more The components may be emulsified at the same time so that the dispersed particles contain a plurality of components.

[Aggregation process]
In the aggregation process, the resin particle dispersion obtained in the emulsification process, a colorant dispersion, and the like are mixed to form a mixed liquid, which is heated at a temperature equal to or lower than the glass transition temperature of the binder resin for aggregation. Form particles. Aggregated particles are formed by making the pH of the mixed solution acidic while stirring. As pH, the range of 2-7 is preferable, the range of 2.2-6 is more preferable, and the range of 2.4-5 is further more preferable.

  It is also effective to use a flocculant when forming the agglomerated particles. As the flocculant, a surfactant having a polarity opposite to that of the surfactant used for the dispersant, an inorganic metal salt, and a divalent or higher metal complex are preferably used. The use of a metal complex is particularly preferred because the amount of surfactant used can be reduced and charging characteristics are improved.

  Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate, and polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. Examples thereof include inorganic metal salt polymers. Among these, an aluminum salt and a polymer thereof are particularly preferable. In order to obtain a narrower particle size distribution, the valence of the inorganic metal salt is bivalent than monovalent, trivalent than bivalent, trivalent than trivalent, and tetravalent than trivalent. Inorganic metal salt polymers are more suitable.

  Further, when the aggregated particles have a desired particle diameter, colored particles having a structure in which the surface of the core aggregated particles is coated with a binder resin can be prepared by additionally adding resin particles (resin emulsified particles). Good. In this case, the release agent and the crystalline polyester resin are less likely to be exposed on the surface of the colored particles, which is a preferable configuration from the viewpoint of chargeability and storage stability. In the case of additional addition, a flocculant may be added or pH adjustment may be performed before additional addition.

[Fusion process]
In the fusion step, the agglomeration is stopped by increasing the pH of the suspension of the aggregated particles to a range of 4 to 8 under the stirring conditions according to the aggregation step, and the glass transition temperature is higher than the glass transition temperature of the binder resin. The aggregated particles are fused by heating at a temperature. An aqueous NaOH solution is preferred as the alkaline solution used to raise the pH. The aqueous NaOH solution has lower volatility and higher safety than other alkaline solutions such as an ammonia solution. In addition, compared with a divalent alkali solution such as Ca (OH) _2, it is excellent in solubility in water, requires a small amount of addition, and is excellent in the ability to stop aggregation.

The heating time may be as long as fusion between particles is performed, and is preferably 0.5 to 10 hours. Cooling is performed after the aggregated particles are fused to obtain fused particles. Also, in the cooling process, the cooling rate is increased in the vicinity of the melting temperature of the release agent and binder resin (melting temperature ± 10 ° C range), so-called rapid cooling enables recrystallization of the release agent and binder resin. It may be suppressed to suppress surface exposure.
Through the above steps, colored particles are obtained as fused particles.

The colored particles used in the present embodiment are also produced by a kneading and pulverizing method.
In order to produce colored particles by the kneading and pulverization method, for example, a binder resin, a colorant, a release agent, and the like are melt-kneaded and dispersed using, for example, a pressure kneader, a roll mill, an extruder, etc. Further, there is used a method of pulverizing with a jet mill or the like and classifying with a classifier such as an air classifier to prepare colored particles having a target particle size.

(2) Electrostatic Image Developer The electrostatic image developing toner according to this embodiment is used as it is as a one-component developer or as a two-component developer. When used as a two-component developer, it is used by mixing with a carrier. The electrostatic charge image developer of the present embodiment is preferably a two-component developer.

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The carrier used for the two-component developer in the present embodiment is preferably a carrier having a resin layer (resin coating layer) on the core material surface (hereinafter also referred to as a resin-coated carrier).
The core material is not particularly limited, and is a magnetic particle dispersion containing magnetic metal particles such as iron, steel, nickel and cobalt, or a magnetic oxide or magnetic powder (magnetic particles) such as ferrite and magnetite, and a binder resin. Examples include mold cores. As the core material in the present embodiment, a core material in which magnetic powder is dispersed in a binder resin is preferable because the specific gravity is light and the stress applied to the toner is small.

As said magnetic powder disperse | distributed in binder resin, the thing of the structure shown by Formula (1) is preferable.
(MO) _X (Fe ₂ O ₃ ) _Y (1)
In the formula (1), M represents at least one selected from the group consisting of Cu, Zn, Fe, Mg, Mn, Ca, Li, Ti, Ni, Sn, Sr, Al, Ba, Co, and Mo, X and Y represent mol ratios and satisfy the condition X + Y = 100.

As the magnetic powder dispersed in the binder resin, conventionally known magnetic powders can be used, and ferrite, magnetite, and maghematite are preferable. As the ferromagnetic magnetic particles, magnetite and maghematite are preferable. Other magnetic particles are preferably iron powder.
Examples of magnetic particles include iron-based oxides such as magnetite, γ-iron oxide, Mn—Zn-based ferrite, Ni—Zn-based ferrite, Mn—Mg-based ferrite, Li-based ferrite, and Cu—Zn-based ferrite. Among these, magnetite is preferable. The magnetic particles may be subjected to various surface treatments, and those subjected to surface treatment with a silane coupling agent, a titanium coupling agent, silicone oil, or the like are preferably used.

The volume average particle size of the magnetic powder is preferably from 0.01 to 1 μm, more preferably from 0.05 to 0.7 μm, from the viewpoint of surface smoothness and dispersion uniformity, and preferably from 0.1 to 0 More preferably, it is 6 μm.
The content of the magnetic particles in the core material is preferably 30 to 95% by weight, more preferably 45 to 90% by weight, and still more preferably 60 to 90% by weight in order to obtain a desired magnetic force.

  As the binder resin constituting the core material, polyolefin resins such as polyethylene and polypropylene; polystyrene, acrylic resin, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether, polyvinyl ketone, and the like Polyvinyl resins and polyvinylidene resins; vinyl chloride-vinyl acetate copolymers; styrene-acrylic acid copolymers; straight silicone resins composed of organosiloxane bonds or modified products thereof; polytetrafluoroethylene, polyvinyl fluoride, polyfluoride Fluorine resins such as vinylidene and polychlorotrifluoroethylene; silicone resin; polyester; polyurethane; polycarbonate; phenol resin; Formaldehyde resins, melamine resins, benzoguanamine resins, urea resins, amino resins such as polyamide resins, epoxy resins and the like. These may be used individually by 1 type and may use 2 or more types together. In this embodiment, a phenol resin is preferable.

  The magnetic particle-dispersed core material may further contain other components. Examples of other components include a charge control agent and fluorine-containing particles.

  The resin constituting the resin layer of the resin-coated carrier is not particularly limited as long as it is used as a binder resin.

As the resin layer, a resin layer containing conductive particles (hereinafter also referred to as conductive particles) is used. Here, the conductivity means that the volume resistivity is less than 10 ⁷ Ω · cm. Examples of the conductive particles include metal particles such as gold, silver, and copper; carbon black particles; particles of metal oxides such as titanium oxide and zinc oxide; titanium oxide, zinc oxide, barium sulfate, aluminum borate, and potassium titanate. Examples thereof include particles whose surface such as powder is covered with tin oxide, carbon black, metal, and the like. These may be used individually by 1 type and may use 2 or more types together. Among these, carbon black particles are desirable.
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 desirable.

  The method for producing the carrier is not particularly limited as long as the carrier having the above structure is formed. For example, the carrier is prepared by first mixing a resin layer forming solution obtained by stirring and dispersing a solution in which a resin is dissolved using a disperser (for example, Ultra Turrax T50) and a carrier core material in a kneader coater. Manufactured by removing the solvent.

  The volume average particle size of the core material of the carrier is preferably 10 to 500 μm and more preferably 30 to 100 μm from the viewpoint of improving the image quality.

The carrier shape factor SF1 is preferably 100 to 120, more preferably 100 to 119, and even more preferably 100 to 118, from the viewpoint of improving the fluidity of the developer. By improving the fluidity of the developer, the amount of developer on the developer holding member is stabilized, and the image density and image quality are stabilized not only in the initial stage but also in the case where time has elapsed due to continuous operation. Further, since the bulk density of the developer is high, the toner density control in the developer by the magnetization sensor is improved, and the image density and image quality are further stabilized.
Here, the shape factor SF1 is obtained by the following equation.
SF1 = (ML ² / A) × (π / 4) × 100
In the formula, ML represents the absolute maximum length of the carrier, and A represents the projected area of the carrier.

The carrier shape factor SF2 is preferably 100 to 120, more preferably 100 to 119, and still more preferably 100 to 118, from the viewpoint of improving the fluidity of the developer. By improving the fluidity of the developer, the amount of developer on the developer holding member is stabilized, and the image density and image quality are stabilized not only in the initial stage but also in the case where time has elapsed due to continuous operation. Further, since the bulk density of the developer is high, the toner density control in the developer by the magnetization sensor is improved, and the image density and image quality are further stabilized. An excellent effect is obtained by the combination with the shape factor SF1.
Here, the shape factor SF2 is obtained by the following equation.
SF2 = (L ² / S) × {100 / (4π)}
In the equation, L represents the peripheral length of the projected image of the carrier, and S represents the projected area of the carrier.

  The specific gravity of the carrier is preferably 3.2 to 4.2 and more preferably 3.4 to 4.0 because it reduces the mechanical external force on the toner.

  The mixing ratio (weight ratio) of the electrostatic image developing toner according to the exemplary embodiment and the carrier in the two-component developer is toner: carrier from the viewpoint of obtaining a stable image density and good image quality without fogging. = 1: 100-30: 100 is preferable, and 3: 100-20: 100 is more preferable.

(3) Image Forming Apparatus and Image Forming Method Next, the electrostatic image developing toner according to the present embodiment and the image forming apparatus and image forming method according to the present embodiment using the electrostatic image developer. explain.
The image forming apparatus according to the present embodiment includes at least a photosensitive member, a charging unit that uniformly charges the photosensitive member, and electrostatic latent image formation that exposes the charged photosensitive member to form an electrostatic latent image. Developing means for developing the electrostatic image formed on the photosensitive member as a toner image with a developer containing toner, and transfer for transferring the toner image formed on the photosensitive member onto the transfer target. And a fixing unit that fixes the toner image transferred onto the transfer target, wherein the fixing unit is a fixing device having a surface pressure of 0.02 MPa to 0.2 MPa, and the toner or developer Is an electrostatic charge image developing toner or an electrostatic charge image developer according to the exemplary embodiment.
The image forming method according to the present embodiment includes a charging step for uniformly charging a photoconductor, an electrostatic latent image forming step for forming an electrostatic latent image by exposing the charged photoconductor, A developing step of developing the electrostatic image formed on the photosensitive member as a toner image with a developer containing toner, a transferring step of transferring the toner image formed on the photosensitive member onto the transfer target, and A fixing step of fixing the toner image transferred onto the transfer target, and the fixing step is a step of fixing at a surface pressure of 0.02 MPa or more and 0.2 MPa or less, and the toner or developer is used in the present embodiment. The toner of the present invention is an electrostatic charge image developing toner or an electrostatic charge image developer.

  In the image forming apparatus and the image forming method of this embodiment, when the surface pressure at the pressure contact portion is 0.02 MPa or more, the toner image is satisfactorily fixed on the transfer target. In addition, when the surface pressure at the pressure contact portion is 0.2 MPa or less, generation of wrinkles of the transferred body is suppressed and stretching of the transferred body is suppressed. In addition, the fixing unit can have a long lifetime, and the fixing unit can be obtained at low cost. The “surface pressure” means a pressure applied per unit area.

In this image forming apparatus, for example, the part including the developing unit may have a cartridge structure (process cartridge) that can be attached to and detached from the image forming apparatus main body. As the process cartridge, a developer holding body is used. A process cartridge according to this embodiment that is provided at least and contains the electrostatic charge image developer according to this embodiment is preferably used.
Hereinafter, an example of the image forming apparatus according to the present embodiment will be described, but the present invention is not limited thereto. In addition, the main part shown to a figure is demonstrated and the description is abbreviate | omitted about others.

  FIG. 1 is a schematic configuration diagram showing a quadruple tandem color image forming apparatus. The image forming apparatus shown in FIG. 1 is a first to first electrophotographic method that outputs yellow (Y), magenta (M), cyan (C), and black (K) images based on color-separated image data. Fourth image forming units 10Y, 10M, 10C, and 10K (image forming means) are provided. These image forming units (hereinafter sometimes simply referred to as “units”) 10Y, 10M, 10C, and 10K are juxtaposed in a horizontal direction separated from each other by a predetermined distance. The units 10Y, 10M, 10C, and 10K may be process cartridges that are detachable from the main body of the image forming apparatus.

Above each of the units 10Y, 10M, 10C, and 10K, an intermediate transfer belt 20 as an intermediate transfer member is extended through each unit. The intermediate transfer belt 20 is provided by being wound around a driving roller 22 and a support roller 24 that are in contact with the inner surface of the intermediate transfer belt 20 that are arranged away from each other in the left to right direction in the drawing, and the first unit 10Y to the fourth unit. It is designed to travel in the direction toward 10K. The support roller 24 is applied with a force in a direction away from the driving roller 22 by a spring or the like (not shown), and tension is applied to the intermediate transfer belt 20 wound around the both. Further, an intermediate transfer member cleaning device 30 is provided on the side of the image carrier of the intermediate transfer belt 20 so as to face the driving roller 22.
Further, in each of the units 10Y, 10M, 10C, and 10K, developing units (developing means) 4Y, 4M, 4C, and 4K, yellow, magenta, cyan, and black stored in toner cartridges 8Y, 8M, 8C, and 8K, respectively. The four color toners can be supplied.

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

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

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

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

  In the developing device 4Y, for example, an electrostatic charge image developer according to the present embodiment including at least yellow toner and a carrier is accommodated. The yellow toner is triboelectrically charged by being agitated inside the developing device 4Y, and has a charge of the same polarity (negative polarity) as that charged on the photoreceptor 1Y, and a developer roll (developer holder). Is held on. As the surface of the photoreceptor 1Y passes through the developing device 4Y, yellow toner adheres electrostatically to the latent image portion on the surface of the photoreceptor 1Y, and the latent image is developed with the yellow toner. . The photoreceptor 1Y on which the yellow toner image is formed continues to run at a predetermined speed, and the toner image developed on the photoreceptor 1Y is conveyed to a predetermined primary transfer position.

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

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

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

  Thereafter, the recording paper P is fed to the pressure contact portion (nip portion) of the pair of fixing rolls in the fixing device (roll-type fixing means) 28, the toner image is heated, and the color-superposed toner image is melted to record the recording paper. Fixed onto P. From the viewpoint of suppressing power consumption, the fixing temperature is preferably 145 ° C. or lower, and more preferably 100 to 140 ° C.

Examples of the transfer target to which the toner image is transferred include plain paper and OHP sheet used for electrophotographic copying machines, printers, and the like.
In order to further improve the smoothness of the image surface after fixing, it is preferable that the surface of the transfer target is as smooth as possible. For example, coated paper in which the surface of plain paper is coated with a resin or the like, for printing Art paper or the like is preferably used.

The recording paper P on which the color image has been fixed is carried out toward the discharge unit, and a series of color image forming operations is completed.
The image forming apparatus exemplified above is configured to transfer the toner image onto the recording paper P via the intermediate transfer belt 20, but the present invention is not limited to this configuration, and the toner image is directly transferred from the photoconductor. It may be a structure that is transferred to a recording sheet.

(4) Process Cartridge and Toner Cartridge FIG. 2 is a schematic configuration diagram showing a preferred example embodiment of a process cartridge containing an electrostatic charge image developer according to this embodiment. In the process cartridge 200, the charging roller 108, the developing device 111, the photoconductor cleaning device 113, the opening 118 for exposure, and the opening 117 for static elimination exposure are combined using the mounting rail 116 together with the photoconductor 107. , And integrated. In FIG. 2, reference numeral 300 denotes a transfer target.
The process cartridge 200 is detachable from an image forming apparatus main body including a transfer device 112, a fixing device 115, and other components (not shown). It forms a forming apparatus.

  The process cartridge 200 shown in FIG. 2 includes a charging device 108, a developing device 111, a photoconductor cleaning device 113, an opening 118 for exposure, and an opening 117 for static elimination exposure. It is possible to combine them selectively. In the process cartridge of this embodiment, in addition to the photosensitive member 107, the charging device 108, the developing device 111, the photosensitive member cleaning device (cleaning means) 113, the opening 118 for exposure, and the opening for static elimination exposure. At least one selected from the group consisting of the unit 117.

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

  Therefore, in the image forming apparatus having a configuration in which the toner cartridge can be attached and detached, by using the toner cartridge containing the electrostatic image developing toner according to this embodiment, the electrostatic image developing device according to this embodiment is used. Toner is supplied to the developing machine.

  The image forming apparatus shown in FIG. 1 is an image forming apparatus having a configuration in which the toner cartridges 8Y, 8M, 8C, and 8K can be attached and detached, and the developing machines 4Y, 4M, 4C, and 4K are each developing machines ( And a toner supply pipe (not shown). Further, when the toner stored in the toner cartridge becomes low, the toner cartridge is replaced.

  Hereinafter, although an Example and a comparative example are given and this embodiment is described in detail in detail, this embodiment is not limited to the following examples. Unless otherwise specified, “parts” and “%” represent “parts by weight” and “% by weight”.

1. Synthesis of resin for binder resin and resin particle (synthesis of amorphous polyester resin (1))
In a heat-dried two-necked flask, 90 mol parts of polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane, 10 mol parts of ethylene glycol, 80 mol parts of terephthalic acid, and isophthalic acid 20 mol part as a raw material, dibutyltin oxide is added as a catalyst, nitrogen gas is introduced into the container and heated in an inert atmosphere, and then subjected to a copolycondensation reaction at 150 to 230 ° C. for about 12 hours, The pressure was gradually reduced at 210 to 250 ° C. to synthesize amorphous polyester resin (1).
The weight average molecular weight (Mw) of the amorphous polyester resin (1) was 23,200. Moreover, the acid value of the amorphous polyester resin (1) was 14.2 KOH mg / g. The glass transition temperature (Tg) of the amorphous polyester resin (1) was 62 ° C.

(Synthesis of amorphous polyester resin (2))
The amorphous polyester resin (2) was synthesized in the same manner as the amorphous polyester resin (1) except that the condensation polymerization reaction time was about 11 hours.
The weight average molecular weight (Mw) of the amorphous polyester resin (2) was 18,400. The acid value of the amorphous polyester resin (2) was 17.4 KOHmg / g. The glass transition temperature (Tg) was 60 ° C.

2. Production of resin particles (Production of resin particles (1))
Amorphous polyester resin (1) 100 parts Solvent (1): Methyl ethyl ketone 40 parts Solvent (2): 2-propanol 25 parts Basic compound: 10% by weight aqueous ammonia solution 3.5 parts Distilled water (dried nitrogen before dropping) 400 parts deoxygenated by bubbling under reduced pressure): 400 parts Amorphous polyester resin (1), solvent (1) and solvent (2) were put into a container capable of temperature control and nitrogen substitution, and amorphous After dissolving the polyester resin (1), the basic compound was added and the resin was stirred at 150 rpm using a three-one motor (manufactured by Shinto Kagaku Co., Ltd.) with an anchor blade attached at 41 ° C. for 10 minutes. A containing liquid was obtained.
Next, the container was purged with dry nitrogen, the temperature was set to 41 ° C., and phase-inversion emulsification was performed by adding distilled water dropwise at a rate of 1 part / min while stirring the resin-containing liquid at 180 rpm.
After completion of the dropwise addition, the solvent (1) and the solvent (2) were removed by performing dry nitrogen bubbling at 25 ° C. for 24 hours while stirring at 70 rpm to obtain a resin particle dispersion (1). The volume average particle diameter of the resin particles (1) in the obtained resin particle dispersion (1) was 190 nm.
Next, the obtained dispersion was put into a metal vat and liquid nitrogen was added to perform quick freezing. The frozen resin particle dispersion (1) was put into a freeze vacuum dryer and vacuum dried at 25 ° C. to obtain resin particles (1).

(Preparation of resin particles (2))
A resin particle dispersion (2) was obtained in the same manner as the resin particle dispersion (1) except that the amorphous polyester resin (1) was replaced with the amorphous polyester resin (2). The volume average particle diameter of the resin particles (2) in the obtained resin particle dispersion (2) was 160 nm. Thereafter, the same operation as that for the resin particles (1) was performed to obtain resin particles (2).

(Preparation of resin particles (3))
Phase inversion emulsification was carried out in the same manner as the resin particles (1) except that 25 parts of methyl ethyl ketone and 15 parts of 2-propanol were changed and stirring after the temperature increase was changed to 90 rpm. The volume average particle diameter of the resin particles (3) in the obtained resin particle dispersion (3) was 700 nm, and the particle size distribution was broad. Thereafter, the same operation as that for the resin particles (1) was performed to obtain resin particles (3).

(Preparation of resin particles (4))
Phase inversion emulsification was carried out in the same manner as in the resin particles (1) except that 60 parts of methyl ethyl ketone and 40 parts of 2-propanol were changed, and stirring after temperature elevation was changed to 200 rpm. The volume average particle diameter of the resin particles (4) in the obtained resin particle dispersion (4) was 60 nm. Thereafter, the same operation as that for the resin particles (1) was performed to obtain resin particles (4).

(Preparation of resin particles (5))
The amorphous resin (1) was finely pulverized with a micronizer pulverizer and classified with an elbow jet classifier to obtain resin particles (5) having a volume average particle diameter of 8.0 μm.

(Preparation of resin particles (6))
370 parts of ion exchange water and 0.3 part of a surfactant were added to the polymerization reaction tank, and the temperature was raised to 75 ° C. while stirring and mixing. On the other hand, the following components were charged into an emulsification tank and mixed by stirring to prepare an emulsion.
Ion-exchanged water 170 parts Anionic surfactant (Neogen SC: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 3 parts Styrene 300 parts n-butyl acrylate 70 parts β-carboxyethyl acrylate 11 parts Dodecanethiol 6 parts 1,6-hexane 5 parts of diol diacrylate When the temperature of the polymerization tank is stabilized, 2% of the weight of the prepared emulsion is added to the reaction tank over 10 minutes, and then 5 parts of ammonium persulfate is diluted 5 times with ion-exchanged water. The stirring speed was increased from 160 rpm to 240 rpm, added to the reaction vessel over 10 minutes, and held for 20 minutes. Next, the stirring speed is lowered from 240 rpm to 160 rpm, and the remaining emulsion is added to the reaction vessel over 3 hours. After the addition is completed, the reaction is continued for another 3 hours, and the volume average particle diameter is 220 nm. (6) was obtained.
The obtained resin particle dispersion (6) is put into an osmotic membrane, immersed in a dilute solution adjusted to pH 9.0 with an aqueous sodium hydroxide solution to remove impurities, and then subjected to the same operation as the resin particle (1). (6) was obtained.
The weight average molecular weight of the resin particles (6) was 46,000, and the glass transition temperature (Tg) was 60 ° C.

3. Production of inorganic particles (Production of SiO ₂ particles (1))
The silica sol obtained by the sol-gel method was treated with HMDS (hexamethyldisilazane), and dried and crushed to obtain SiO ₂ particles (1) having a volume average particle diameter of 140 nm.

(Preparation of SiO ₂ particles (2))
Silica sol obtained by the sol-gel method was treated with HMDS (hexamethyldisilazane), and dried and crushed to obtain SiO ₂ particles (2) having a volume average particle diameter of 520 nm.

(Preparation of SiO ₂ particles (3))
Silica sol obtained by the sol-gel method was treated with HMDS (hexamethyldisilazane), and dried and ground to obtain SiO ₂ particles (3) having a volume average particle diameter of 70 nm.

(Production of titanium oxide external additive)
A rutile type titanium oxide (MT-150A, Teica) having a volume average particle size of 15 nm, which was washed with water in a methanol-water (95: 5) mixed solvent in which 1.0 part of methyltrimethoxysilane was dissolved to reduce the amount of water-soluble components. 10 parts of powder was added and ultrasonically dispersed. Next, after evaporating methanol and the like in the dispersion with an evaporator, drying, heat treatment with a dryer set at 120 ° C., grinding with a mortar, and surface treatment with methyltrimethoxysilane, the titanium oxide external additive Got.

4). Preparation of release agent dispersion (release agent dispersion)
・ 50 parts of paraffin wax (Nippon Seiwa Co., Ltd., HNP-9, melting point: 75 ° C.) 0.5 part of anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen RK) : 200 parts or more were mixed, heated to 95 ° C., and dispersed using a homogenizer (manufactured by IKA, Ultra Turrax T50). Thereafter, the mixture was dispersed with a Manton Gorin high-pressure homogenizer (manufactured by Gorin Co., Ltd.) to prepare a release agent dispersion (solid content concentration: 20%) in which the release agent was dispersed. The volume average particle diameter of the release agent was 0.23 μm.

5. Preparation of colorant dispersion (colorant dispersion)
Cyan pigment (Daiichi Seika Co., Ltd., Pigment Blue 15: 3 (copper phthalocyanine) 1,000 parts Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen R) 15 parts 9,000 parts or more are mixed, dissolved, and dispersed for 1 hour using a high-pressure impact disperser Ultimateizer (manufactured by Sugino Machine Co., Ltd., HJP30006) to disperse a colorant (cyan pigment). The colorant (cyan pigment) in the colorant dispersion had a volume average particle size of 0.16 μm and a solid content concentration of 20%.

I. Preparation and evaluation of toner for developing electrostatic image 1. Preparation of toner for developing electrostatic image (Example 1)
<Production of Toner (1)>
Amorphous polyester resin dispersion liquid (1) 267 parts Colorant dispersion liquid 25 parts Release agent dispersion liquid 40 parts Anionic surfactant (Taika Power / manufactured by Teika Co., Ltd.) 2.0 parts -Mixing process-
The raw material was placed in a cylindrical stainless steel container, and the homogenizer (Ultra Turrax T50, manufactured by IKA) was used. The homogenizer was rotated at 4,000 rpm and dispersed and mixed for 10 minutes while applying a shearing force. Next, 2.0 parts of a 10% nitric acid aqueous solution of polyaluminum chloride (PAC) as a flocculant (the content of nitric acid is 0.05N) is gradually dropped, and the homogenizer is rotated at 5,000 rpm for 15 minutes. And mixed to obtain a raw material dispersion.

-Aggregation process-
Thereafter, the raw material dispersion was transferred to a polymerization kettle equipped with a stirrer and a thermometer and started to be heated with a mantle heater to promote the growth of aggregated particles at 42 ° C. At this time, the pH of the raw material dispersion was adjusted to a range of 3.2 or more and 3.8 or less using 0.3N nitric acid or 1N sodium hydroxide aqueous solution. The raw material dispersion was kept in the above pH range and allowed to stand for about 2 hours to form aggregated particles. The volume average particle diameter of the aggregated particles was 5.4 μm.

-Fusion process-
Next, 100 parts of the amorphous polyester resin dispersion (1) was additionally added to the raw material dispersion, and the resin particles of the amorphous polyester resin (1) were adhered to the surface of the aggregated particles. Further, the temperature of the raw material dispersion was raised to 44 ° C., and aggregated particles were prepared while confirming the size and form of the particles using an optical microscope and Multisizer II. Thereafter, in order to fuse the aggregated particles, an aqueous NaOH solution was added dropwise to the raw material dispersion to adjust the pH to 7.5, and then the raw material dispersion was heated to 95 ° C. Thereafter, the raw material dispersion was allowed to stand for 3 hours to fuse the aggregated particles. After confirming that the aggregated particles were fused with an optical microscope, the colored particle dispersion was cooled at a temperature lowering rate of 1.0 ° C./min.

-Washing process-
Next, the colored particle dispersion was filtered, and the colored particles after solid-liquid separation were dispersed in ion-exchanged water at 30 ° C., which is 20 times the solid content of the colored particles, and filtered by stirring for 20 minutes. . This process was repeated 5 times, and it was confirmed that the filtrate had a conductivity of 25 μS. The colored particles were filtered and dried with a freeze dryer to obtain colored particles (1).

(Dry external addition)
With respect to 100 parts of the colored particles (1), as external additives, SiO ₂ particles (1) 1.4%, the produced titanium oxide external additive 1.2%, and resin particles (1) 1.5% % Was added and mixed with a Henschel mixer for 5 minutes. Furthermore, the toner (1) was obtained by passing through an ultrasonic vibration sieve (45 μm / Dalton).

2. Evaluation of toner for developing electrostatic image <Measurement of viscoelasticity | G ^* | / tan δ>
The toner particles (1) and the resin particles (1) were evaluated as follows.
Using a rheometer (Rheometric Scientific Co., Ltd .: ARES rheometer), a temperature rise measurement was performed under the condition of a frequency of 1 Hz using a parallel plate. A sample is set at about 120 ° C to 140 ° C, cooled to room temperature, heated at a heating rate of 1 ° C / min, measured every 1 ° C in the range of 30 ° C to 150 ° C, and complex elasticity at 110 ° C. The absolute value of the rate (| G ^* |) and tan δ were measured. The measurement results are shown in Table 1.

<Preservation evaluation>
Toner (1) was placed in a 10 cm × 10 cm box and left to stand for 24 hours in a 50 ° C./50% RH environment with a load applied to 20 g / cm ² to obtain a sample. Next, using a powder tester (manufactured by Hosokawa Micron Co., Ltd.), sieves with openings of 53 μm, 45 μm, and 38 μm are arranged in series from the top, and 2 g of the above-mentioned standing sample accurately weighed on the 53 μm sieve is charged. Then, vibration is applied for 90 seconds with an amplitude of 1 mm, and the toner weight on each sieve after vibration is measured, added with a weight of 0.5, 0.3, and 0.1, and calculated as a percentage. did. In this embodiment, as long as the weight of the toner after vibration is 40 or less, the storability can usually be used without any practical problem, but is preferably 35 or less, and more preferably 30 or less. The evaluation results are shown in Table 1.

II. Preparation and evaluation of electrostatic charge image developer Preparation of carrier (preparation of carrier (1)) ... Polymerization carrier Into a Henschel mixer, 500 parts of spherical magnetite particle powder having a volume average particle diameter of 0.55 µm was added and stirred sufficiently, and then titanate coupling agent 5 0.0 part was added, the temperature was raised to about 100 ° C., and the mixture was stirred for 30 minutes to obtain spherical magnetite particles coated with a titanate coupling agent.
Subsequently, 6.25 parts of phenol, 9.25 parts of 35% formalin, 500 parts of the spherical magnetite particles, 6.25 parts of 25% aqueous ammonia, and 425 parts of water were placed in a 1 L four-necked flask and mixed and stirred. . Next, the temperature is raised to 85 ° C. over 60 minutes with stirring and reacted at the same temperature for 120 minutes, then cooled to 25 ° C., 500 ml of water is added, the supernatant is removed, and the precipitate is washed with water. did. This was dried at 150 ° C. or higher and 180 ° C. or lower under reduced pressure to obtain spherical polymer core particles having a volume average particle diameter of 35 μm.

Next, a resin layer was formed on the surface of the core material by the following method.
200 parts of toluene and 30 parts of a styrene-methyl methacrylate copolymer (component ratio 30:70, weight average molecular weight 210,000) were stirred with a stirrer for 60 minutes to obtain a resin coating solution. 100 parts of the resin coating solution and 1.57 parts of carbon black (Regal 330: manufactured by Cabot) were stirred for 10 minutes at 5,000 rpm using a homogenizer (IKA: Ultra Tarrax) to prepare a dispersion.
After 1,000 parts of core material particles and 61.3 parts of the above dispersion were put into a vacuum degassing type kneader coater, the temperature was kept at 60 ° C. and stirred for 30 minutes at 40 rpm, and the temperature was further reduced to 70 ° C. Distilled, degassed and dried. Furthermore, carrier (1) was prepared by passing through a mesh having an opening of 75 μm. The volume average particle diameter of the carrier (1) was 37 μm.
The obtained carrier (1) was observed using a scanning electron microscope (manufactured by Hitachi, Ltd .: S-4100) to take an image, and this image was captured by an image analyzer (for example, LUZEXIII, Nireco Corporation). SF1 and SF2 were calculated for each particle of 100 or more particles, and the average value was obtained as SF1 and SF2 of the carrier (1). The SF1 of carrier (1) was 106, and SF2 was 104. The specific gravity of the carrier was 3.6.

2. Evaluation <Evaluation of minimum fixing temperature>
8 parts by weight of toner (1) and 92 parts by weight of carrier (1) were placed in a V blender, stirred for 20 minutes, and then sieved with a 105 μm mesh to prepare developer (1). The obtained developer (1) was filled in a developing machine of DocuPrint C2220 (manufactured by Fuji Xerox Co., Ltd.), and the developing machine was mounted on DocuPrint C2220 from which the fixing device was removed, and the following unfixed images were collected.
Test paper: Recycled copy paper G70 manufactured by Fuji Xerox Co., Ltd. (70% waste paper pulp, 67g / m ² basis weight, 72% ISO whiteness)
-Image 1: Highlight image with 2 cm x 5 cm, image area ratio 30%-Image 2: Character image with 2 cm x 5 cm, image area ratio 5% Next, the obtained unfixed image is DC155 (Fuji Xerox Co., Ltd.) An unfixed image was fixed under the following fixing conditions by using a fixing device in which the fixing pressure was made variable by modifying the roll type fixing device (manufactured).
・ Surface pressure: 0.06 MPa
・ Process speed: 200mm / s
Fixing temperature: carried out by increasing the temperature from 110 ° C. every 5 ° C. The obtained fixed images 1 and 2 were evaluated for image strength using an image ironing tester. Images 1 and 2 are images of isolated dots and thin lines, and this evaluation can be said to be an evaluation of isolated image intensity. The image squeezing tester includes a pair of cylindrical rubber rolls having a diameter of 10 cm and whose axial directions are parallel. The fixed images fixed under the same conditions are sandwiched between the rubber rolls so that the images overlap each other, and a load is applied so that the load between the rubber rolls is 6 kgf. Rotating conditions The obtained ironed image was evaluated from G1 to G7 using a limit sample, and the fixing temperature when G4 or less, which is no problem in actual use, was set as the minimum fixing temperature. The evaluation results are shown in Table 1.
The limit sample is as follows.
G1: Neither image loss nor white paper stain is seen G2: Image loss is not seen, but white paper is slightly dirty G3: Image loss is not seen, but white paper is dirty Visible G4: Image loss is slightly seen but there is no problem in character discrimination G5: Some image loss is seen and character discrimination is a little difficult G6: Most images are missing and characters G7: All images are largely missing and characters cannot be identified

<Evaluation of minimum fixing temperature change (Δ ° C)>
Next, the developing machine was taken out and idled at a speed of 350 rpm for 60 minutes. Then, the developing machine was mounted again, and an unfixed image was collected in the same manner for fixing evaluation. The difference between the initial minimum fixing temperature and the minimum fixing temperature after idling of the developing machine was defined as the minimum fixing temperature change (Δ ° C.). The evaluation results are shown in Table 1.

(Image gloss evaluation)
Test paper: C2 paper (Fuji Xerox Co., Ltd./basis weight 70 g / m ² )
Image: 4 cm × 5 cm, toner application amount: 0.6 mg / cm ² , image area ratio: 100% solid image Gloss evaluation of a sample image fixed at a temperature 20 ° C. higher than the minimum fixing temperature was performed. The measurement was based on JIS Z 8741, using Gloss Meter GM-26D (Murakami Color Research Laboratory) at an incident angle of 75 °.
The numerical value of image gloss is preferably 40 or less, and more preferably 35 or less. The evaluation results are shown in Table 1.

(Image density stability evaluation)
The obtained developer is set in a DocuCentreColor400CP remodeling machine manufactured by Fuji Xerox Co., Ltd., and a solid image of 5 cm x 5 cm is formed at the center of the paper at a development process speed of 200 mm / sec, and 5,000 images are output. did. The image densities of the 10th and 5,000th sheets were measured using an image densitometer (X-Rite 404A: manufactured by X-Rite), and evaluated based on the following evaluation criteria from the image density measurement results. .
From the measurement result of the image density, the evaluation was made according to the following evaluation criteria.
A: The image density of the 5,000th sheet is 97% or more with respect to the 10th sheet.
○: The image density of the 5,000th sheet is 94% or more and less than 97% with respect to the 10th sheet.
Δ: The image density of the 5,000th sheet is 90% or more and less than 94% with respect to the 10th sheet.
X: The image density of the 5,000th sheet is less than 90% with respect to the tenth sheet.
The evaluation results are shown in Table 1.

(Evaluation of uniformity of image density)
The obtained developer was set in a DocuCentreColor400CP modified machine manufactured by Fuji Xerox Co., Ltd., and a solid image of 3 cm × 3 cm was formed at the center and four corners of the paper at a development process speed of 200 mm / sec. An image was output. The image density of the 10th and 5,000th sheets was measured using an image densitometer (X-Rite 404A: manufactured by X-Rite), and the image density fluctuation of each solid image was measured according to the following evaluation criteria. evaluated.
A: Image density variation is 97% or more.
○: Image density is 94% or more and less than 97%.
Δ: Image density is 90% or more and less than 94%.
X: Image density is less than 90%.
The evaluation results are shown in Table 1.

(Image gloss uniformity evaluation)
The obtained developer is set in a DocuCentreColor400CP remodeling machine manufactured by Fuji Xerox Co., Ltd., and 5,000 images are formed at a development process speed of 200 mm / sec, and the image density Gloss of the tenth and 5,000th images is uniform. Sensory evaluation was performed on the property, and evaluation was performed according to the following evaluation criteria.
From the measurement result of the image density, the evaluation was made according to the following evaluation criteria.
○: No image gloss unevenness.
Δ: Some uneven image gloss is observed.
X: Image gloss unevenness is visible.
The evaluation results are shown in Table 1.

  For the following Examples 2 to 12 and Comparative Examples 1 and 2, toners and developers were produced as follows, and viscoelasticity, storage stability, minimum fixing temperature, minimum fixing temperature change, image gloss, image density The stability, image density uniformity, and image gloss uniformity were measured and evaluated. The results are shown in Table 1.

<Example 2>
A toner (2) and a developer (2) were prepared in the same manner as in Example 1 except that the binder contained in the colored particles and the resin particles added as external additives were changed to resin particles (2). And evaluated.

<Example 3>
A toner (3) and a developer (3) were prepared and evaluated in the same manner as in Example 1 except that the resin particles (1) added as an external additive were changed to resin particles (3).

<Example 4>
A toner (4) and a developer (4) were prepared and evaluated in the same manner as in Example 1 except that the resin particles (1) added as an external additive were changed to resin particles (4).

<Example 5>
A toner (5) and a developer (5) were prepared and evaluated in the same manner as in Example 1 except that the resin particles (1) added as an external additive were changed to resin particles (5).

<Example 6>
A toner (6) and a developer (6) were prepared and evaluated in the same manner as in Example 1 except that the amount of the resin particles (1) added as an external additive was changed to 0.04%.

<Example 7>
A toner (7) and a developer (7) were prepared and evaluated in the same manner as in Example 1 except that the amount of the resin particles (1) added as an external additive was changed to 6.1%.

<Example 8>
Toner (8) and developer in the same manner as in Example 1 except that in the mixing step, the flocculant was changed to 20.0 parts of a 10% aqueous nitric acid solution of magnesium chloride (MgCl ₂ ) (the content of nitric acid was 0.05N). (8) was prepared and evaluated.

<Example 9>
Toner (9) and developer (9) were prepared and evaluated in the same manner as in Example 1 except that 3.6 parts of the flocculant was added in the mixing step.

<Example 10>
A toner (10) and a developer (10) were prepared and evaluated in the same manner as in Example 1 except that the inorganic particles (1) added as an external additive were changed to inorganic particles (2).

<Example 11>
A toner (11) and a developer (11) were prepared and evaluated in the same manner as in Example 1 except that the inorganic particles (1) added as an external additive were changed to inorganic particles (3).

<Example 12>
A toner (12) and a developer (12) were prepared and evaluated in the same manner as in Example 1 except that inorganic particles (SiO ₂ particles) added as an external additive were not added.

<Comparative Example 1>
A toner (C1) and a developer (C1) were prepared and evaluated in the same manner as in Example 1 except that no resin particles were added.

<Comparative example 2>
A toner (C2) and a developer (C2) were prepared and evaluated in the same manner as in Example 1 except that the resin particles (1) added as an external additive were changed to resin particles (6).

III. Career considerations (Example 13)
In addition to the developer (1) used in Example 1, the following carrier (2) was used to prepare a developer (13) in the same manner as in Example 1, and the minimum fixing temperature, minimum fixing temperature change, Image gloss, image density stability, image density uniformity, and image gloss uniformity were evaluated. The evaluation results are shown in Table 2.

(Carrier (2) of Preparation) ... ferrite carrier Fe ₂ O ₃ to 73 parts, MnO ₂ to 23 parts, Mg and (OH) ₂ 4 parts were mixed, 25 hours mixing / grinding to a wet ball mill spray After granulating and drying with a drier, preliminary baking 1 was performed at 800 ° C. for 7 hours using a rotary kiln to obtain a temporary baking product 1.
The obtained calcined product 1 was pulverized with a wet ball mill for 7 hours to have a volume average particle diameter of 1.8 μm, further granulated and dried with a spray dryer, and then 900 ° C. for 6 hours with a rotary kiln. Was calcined 2 to obtain a calcined product 2.
The obtained calcined product 2 was pulverized with a wet ball mill for 5 hours to have an average particle size of 5.2 μm, and further granulated and dried with a spray dryer, and then at 1,000 ° C. using an electric furnace. The main baking was performed for 12 hours. After the main firing, Mn—Mg ferrite core material particles having a volume average particle diameter of 36.6 μm were obtained through a crushing step and a classification step.

Next, a resin layer was formed on the surface of the core material by the following method.
200 parts of toluene and 30 parts of a styrene-methyl methacrylate copolymer (component ratio 30:70, weight average molecular weight 210,000) were stirred with a stirrer for 60 minutes to obtain a resin coating solution.
100 parts of the resin coating solution and 1.57 parts of carbon black (Regal 330: manufactured by Cabot) were stirred for 10 minutes at 5,000 rpm using a homogenizer (IKA: Ultra Tarrax) to prepare a dispersion.
1,000 parts of ferrite core material particles and 30.65 parts of the above dispersion are put into a vacuum degassing type kneader coater, stirred at 40 rpm for 30 minutes while maintaining 60 ° C., and further reduced in temperature to 70 ° C. Toluene was distilled off, degassed and dried. Furthermore, carrier (2) was prepared by passing through a mesh having an opening of 75 μm. The volume average particle diameter of the carrier (2) was 38 μm. The SF1 of carrier (2) was 122, and SF2 was 124. The specific gravity of the carrier was 4.5.

1Y, 1M, 1C, 1K, 107 Photoconductor 2Y, 2M, 2C, 2K, 108 Charging roller (charging device, charging means)
3Y, 3M, 3C, 3K Laser beam 3 exposure device (electrostatic latent image forming means)
4Y, 4M, 4C, 4K, 111 developing machine (developing means)
5Y, 5M, 5C, 5K Primary transfer roller (primary transfer means)
6Y, 6M, 6C, 6K, 113 Photoconductor cleaning device (cleaning means)
8Y, 8M, 8C, 8K Toner cartridge 10Y, 10M, 10C, 10K Image forming unit 20 Intermediate transfer belt 22 Drive roller 24 Support roller 26 Secondary transfer roller (secondary transfer means)
28, 115 Fixing device (roll-type fixing means)
30 Intermediate transfer member cleaning device 112 Transfer device 116 Mounting rail 117 Opening portion 118 for static elimination exposure Opening portion 200 for exposure Process cartridge P, 300 Recording paper (transfer object)

Claims (13)

Having colored particles containing at least a colorant and a binder resin;
On the surface of the colored particles, and inorganic particles, becomes a tree fat particles, the externally added,
The binder resin contains a polyester resin;
The resin particles are resin particles made of the polyester resin contained in the binder resin,
An electrostatic charge image developing toner, wherein the absolute value of the complex elastic modulus of the resin particles is smaller than the absolute value of the complex elastic modulus of the colored particles.   The electrostatic image developing toner according to claim 1, wherein at least one of the inorganic particles has a volume average particle diameter of 100 to 500 nm.   The electrostatic image developing toner according to claim 1, wherein a loss coefficient tan δ (G ″ / G ′) at 110 ° C. is 1.6 or less.   The electrostatic image developing toner according to claim 1, wherein the resin particles have a volume average particle diameter of 100 to 5,000 nm.   The electrostatic image developing toner according to claim 1, wherein the resin particles have a volume average particle diameter of 500 to 5,000 nm.   The toner for developing an electrostatic charge image according to claim 1, wherein the polyester resin in the binder resin and the resin particles is an amorphous polyester resin. The resin particles were 0.1 to 6 wt% externally added relative to the colored particles, according to claim 1-6 or toner according to one. Electrostatic image developer which comprises a toner and a carrier for developing an electrostatic charge image according to claim 1-7 one. The electrostatic charge image developer according to claim 8 , wherein the carrier is a carrier containing a core material in which magnetic powder is dispersed in a binder resin. At least the toner is accommodated, it is detachable to the image forming apparatus, the toner cartridge, wherein the toner is a toner for electrostatic image development according to any one of Claims 1-7. 10. A process cartridge comprising at least a developer holding member, detachable from an image forming apparatus, and containing the electrostatic charge image developer according to claim 8 or 9 . At least with a photoreceptor,
Charging means for uniformly charging the photoreceptor;
An electrostatic latent image forming means for exposing the charged photoreceptor to form an electrostatic latent image;
Developing means for developing the electrostatic image formed on the photoreceptor as a toner image with a developer containing toner;
Transfer means for transferring a toner image formed on the photoreceptor onto a transfer target;
Fixing means for fixing the toner image transferred onto the transfer object,
The fixing unit is a fixing device having a surface pressure of 0.02 MPa to 0.2 MPa;
An image using the electrostatic image developing toner according to any one of claims 1 to 7 as the toner, or the electrostatic image developer according to claim 8 or 9 as the developer. Forming equipment. A charging step for uniformly charging the photoreceptor;
An electrostatic latent image forming step of exposing the charged photoreceptor to form an electrostatic latent image;
A developing step of developing the electrostatic latent image formed on the photoreceptor as a toner image with a developer containing toner;
A transfer step of transferring a toner image formed on the photoreceptor onto a transfer target;
A fixing step of fixing the toner image transferred onto the transfer object,
The fixing step is a step of fixing at a surface pressure of 0.02 MPa to 0.2 MPa,
An image using the electrostatic image developing toner according to any one of claims 1 to 7 as the toner, or the electrostatic image developer according to claim 8 or 9 as the developer. Forming method.

Images