JP2010197732A - Toner for electrostatic charge image development, toner cartridge, process cartridge and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner for electrostatic charge image development, suppressing aggregation of toner particles or deposition of toner particles on a device even when the toner is continuously used. <P>SOLUTION: The toner for electrostatic charge image development contains: toner particles containing a binder resin and a colorant; polytetrafluoroethylene particles having an average particle diameter of ≥100 nm and ≤500 nm deposited on the surfaces of the toner particles; and monodispersion spherical silica particles having an average particle diameter of ≥80 nm and ≤200 nm deposited on the surfaces of the toner particles. The amount of the PTFE particles is from 0.1 to 1 part with respect to 100 parts of the toner particles; and the amount of the silica particles is from 0.5 to 30 parts with respect to 1 part of the PTFE particles. When the toner in an aqueous dispersion liquid is subjected to an ultrasonic treatment by applying ultrasonic vibration at a frequency of 20 kHz and an output power of 20 W for one minute, the amount of PTFE particles not leaving from the toner particles but depositing on the particles is ≥50 mass% and ≤100 mass% of the deposition amount before the ultrasonic treatment. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

A so-called xerographic image forming apparatus includes an electrophotographic photosensitive member (hereinafter, referred to as “photosensitive member” as appropriate), a charging device, an exposure device, a developing device, and a transfer device. Formation takes place. In recent years, xerographic image forming apparatuses have been further improved in speed, image quality, and lifetime due to technological progress of each member and system.
Digitization processing is indispensable as a means for achieving high image quality, and the effect of digitization related to such image quality is that complex image processing can be performed at high speed. For this reason, it is necessary to faithfully create a latent image created by an optical system for image output, and the toner has a reduced particle size. Further, from the viewpoint of speeding up, there is a strong demand for an electrophotographic toner that can be fixed at a low temperature. As means for lowering the fixing temperature of the toner, means having a relatively low glass transition temperature as a resin for the toner (binder) or adding a plasticizer is used to suppress toner particle aggregation. However, it is required to lower the fixing temperature.

Generally, when a toner is subjected to stress by a developing machine or the like, the external additive is liberated and buried, and as a result, there are many areas where the external additive does not exist on the surface of the toner particle, resulting in non-electrostatic adhesion of the toner. This tendency is more pronounced when the low-temperature fixability is good, and it is effective to agglomerate toner particles, adhere to the device, and cause toner clogging in the recovery device due to the adhesion. There is a desire to suppress it.
On the other hand, a technique using inorganic particles having a large particle size as an external additive is disclosed for the liberation and burying prevention of the external additive (for example, see Patent Documents 1 and 2).
Further, a technique for obtaining a spacer effect by adding spherical organic particles of 50 nm or more and 200 nm or less is disclosed (for example, see Patent Document 3).
Further, a monodispersed spherical silica having an average particle diameter of 80 nm or more and 300 nm or less is used to uniformly disperse the toner surface to obtain a spacer effect (for example, refer to Patent Document 4), or at least different in average particle diameter. A technique for preventing the liberation or burying of silica by adding two types of silica is disclosed (for example, see Patent Document 5).

JP-A-7-28276 JP-A-9-319134 JP-A-6-266152 JP 2001-66820 A JP 2007-178623 A

  The object of the present invention is for electrostatic charge image development in which clogging of toner particles due to aggregation of toner particles and adhesion of toner particles to the apparatus is suppressed even when continuously used, compared to the case without this configuration. To provide toner.

The above-mentioned subject is achieved by the following present invention.
That is, the invention according to claim 1
Toner particles containing a binder resin and a colorant, polytetrafluoroethylene particles having an average particle diameter of 100 nm or more and 500 nm or less attached to the toner particle surface, and single particles having an average particle diameter of 80 nm or more and 200 nm or less attached to the toner particle surface. The amount of polytetrafluoroethylene particles added is 0.1 to 1 part by mass with respect to 100 parts by mass of toner particles, and 1 part by mass of polytetrafluoroethylene particles. On the other hand, when the ultrasonic treatment in which the monodispersed spherical silica particles are 0.5 parts by mass or more and 30 parts by mass or less and ultrasonic vibration with an output of 20 W and a frequency of 20 kHz is applied for 1 minute in an aqueous dispersion, The amount of polytetrafluoroethylene particles adhering without detaching is the amount of polytetrafluoroethylene particles before ultrasonic treatment. Adhesion amount of a toner for electrostatic image development more than 50 wt% to 100 wt%.

The invention according to claim 2
2. The electrostatic charge image developing toner according to claim 1, wherein the polytetrafluoroethylene particles adhered to the toner particle surfaces have a shape factor of 120 or more and 160 or less.
The invention according to claim 3
The electrostatic image developing toner according to claim 1 or 2, wherein the toner is obtained by attaching polytetrafluoroethylene particles to the surface of the toner particles and then attaching monodispersed spherical silica particles.

The invention according to claim 4
The toner for developing an electrostatic charge image according to any one of claims 1 to 3, wherein toner to be attached to and detached from an image forming apparatus including a developing unit and supplied to the developing unit is stored. It is a toner cartridge.
The invention according to claim 5
A process cartridge comprising a developing holder and containing an electrostatic charge image developing developer containing the electrostatic charge image developing toner according to any one of claims 1 to 3.
The invention according to claim 6
A latent image carrier,
An electrostatic latent image forming means for forming an electrostatic latent image on the surface of the latent image holding member;
Developing means for developing the electrostatic latent image with a developer containing toner to form a toner image;
Transfer means for transferring the toner image formed on the latent image holding member to the surface of a recording medium;
Toner removing means for removing residual toner remaining on the surface of the latent image holding member,
The image forming apparatus according to claim 1, wherein the developer is an electrostatic charge image developing developer including the electrostatic charge image developing toner according to claim 1.

According to the first aspect of the present invention, the aggregation of the toner particles and the adhesion of the toner particles to the device are suppressed as compared with those having an external additive type and adhesion to the toner particles that are out of the range. An electrostatic charge image developing toner is provided.
According to the second aspect of the present invention, the adhesion of the toner particles to the device is further suppressed as compared with the polytetrafluoroethylene particles whose shape factor is outside the scope of the present invention.

  According to the third aspect of the present invention, the silica particles adhere to the toner particles so as to avoid the polytetrafluoroethylene particles as compared with the case where the order of attachment of the external additives is not considered. Adhesion to the device is further suppressed.

According to the invention of claim 4, the aggregation of the toner particles and the adhesion of the toner particles to the apparatus are suppressed as compared with the case where the type and adhesion of the external additive to the toner particles are out of the range. A toner cartridge is provided.
According to the invention of claim 5, the aggregation of toner particles and the adhesion of toner particles to the device are suppressed as compared with the case where the type and adhesion of the external additive to the toner particles are out of the range. A process cartridge is provided.

  According to the invention of claim 6, the aggregation of the toner particles and the adhesion of the toner particles to the apparatus are suppressed as compared with the case where the type and adhesion of the external additive to the toner particles are out of the range. An image forming apparatus is provided.

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

Hereinafter, the present invention will be described in detail.
<Toner for electrostatic image latent image>
The toner particles in the electrostatic image developing toner of the present embodiment (hereinafter sometimes simply referred to as “toner”) contain a binder resin and a colorant, and if necessary, other additives such as a release agent. May be included. The toner particles have polytetrafluoroethylene particles having an average particle diameter of 100 nm or more and 500 nm or less (hereinafter referred to as PTFE particles as appropriate) as external additives and monodispersed spherical particles having an average particle diameter of 80 nm or more and 200 nm or less on the surface. Silica particles are attached, and the content of the polytetrafluoroethylene particles is from 0.1 parts by weight to 1 part by weight with respect to 100 parts by weight of the toner particles, and with respect to 1 part by weight of the polytetrafluoroethylene particles. The monodispersed spherical silica particles are 0.5 parts by mass or more and 30 parts by mass or less.
In this embodiment, when an ultrasonic treatment in which ultrasonic vibration having an output of 20 W and a frequency of 20 kHz is applied for 1 minute in an aqueous dispersion is performed on a toner having an external additive attached to the surface of the toner particles, the toner particles are detached from the toner particles. The amount of the polytetrafluoroethylene particles adhering without separation is 50% by mass or more and 100% by mass or less of the polytetrafluoroethylene particle adhering amount before the ultrasonic treatment.

The polytetrafluoroethylene particles have the effect of reducing the spacer effect and the friction and adhesion between the toners due to the characteristics of the specific particle size and the low friction coefficient resulting from the material of the particles. The softness of the PTFE particles themselves absorbs the impact during stirring, and even if there is a flexible region due to the presence of non-crystalline resin locally in the toner, the external additive particles adhere to it. In this case, the function of the external additive can be suppressed from being deteriorated due to the external additive particles embedded in the toner particle surface. By these actions, stress on the toner particles due to stirring in the image forming apparatus is reduced, and aggregation of toner particles and adhesion to the apparatus are suppressed. In addition, even when the monodispersed spherical silica particles added externally contact or move between the toner particles or on the surface of the PTFE particles adhering to the surface of the single toner particles during stirring, due to the lubricity of the PTFE particles, Monodispersed spherical silica does not adhere to the area where the PTFE particles are present, and adheres to the periphery of the PTFE particles, resulting in uneven distribution and embedding of external additives in the toner particles containing a binder resin having a low glass transition temperature. The collected toner which has been subjected to stress in the apparatus for a long time because the PTFE particles remain on the surface of the toner particles without being detached even by ultrasonic treatment. Also in the particles, uneven distribution of monodispersed spherical silica is suppressed, and fluidity is maintained. Further, since the external additive is always in contact with the wall surface of the recovery device, recovery clogging is prevented, and aggregation of toner particles and adhesion to the device are effectively suppressed.
As described above, in the toner for developing an electrostatic image including toner particles having polytetrafluoroethylene particles and monodispersed spherical silica particles attached to the surface, an action of suppressing the recovery clogging is achieved.

Hereinafter, details of each component constituting the toner of the exemplary embodiment will be sequentially described.
<Binder resin>
The toner for developing an electrostatic charge image according to the exemplary embodiment includes a binder resin and a colorant as essential components, and may further include a release agent as necessary.
As the toner binder resin, it is most important that the toner has an appropriate compatibility state. This is because the binder resin exhibits low-temperature fixability due to the plasticizing effect of the compatibilized portion in addition to the sharp melt property. In addition, the proper compatibility improves the dispersibility of other materials in the binder resin and acts as a filler, so that it is easy to ensure a certain level of toner strength.

As the binder resin, for example, polyester resin, vinyl resin, polyurethane resin, epoxy resin, polyol resin or the like is used. Hereinafter, the binder resin used in the present invention will be described.
The weight average molecular weight of the binder resin is particularly preferably 10,000 or more, and the weight average molecular weight is usually preferably in the range of 15000 or more and 50000 or less.

1. Binder Resin The binder resin is preferably used in the toner particles in the range of 30% by mass to 98% by mass in terms of solid content, and more preferably in the range of 50% by mass to 98% by mass. .
When the content of the binder resin is in the above range, it is possible to suppress structural variations due to phase separation in the fixed image, the strength of the fixed image, particularly the scratch strength, is improved, and the scratch resistance of the formed image is improved. . Further, toner blocking is suppressed and image storability is maintained.

Examples of the binder resin include a polyester resin and a vinyl resin as described above, and a polyester resin is preferable from the viewpoints of fixing property to paper at the time of fixing, chargeability, and adjustment of a melting point within a preferable range.
A polyester resin synthesized from a carboxylic acid (dicarboxylic acid) component and an alcohol (diol) component is used.
Hereinafter, the carboxylic acid component and the alcohol component will be described in more detail.
As the polyester resin constituting the toner particles of the present embodiment, a commercially available product may be used, or an appropriately synthesized one may be used.

  Examples of the carboxylic acid component include succinic 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, fumar Acid, alkenyl succinic acid, etc., or its lower alkyl esters and acid anhydrides are also aromatic carboxylic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, naphthalenedicarboxylic acid, And alicyclic carboxylic acids such as cyclohexanedicarboxylic acid It is. These polyvalent carboxylic acids may be used alone or in combination of two or more. Of these polyvalent carboxylic acids, it is preferable to use aromatic carboxylic acids, and in order to take a crosslinked structure or a branched structure in order to ensure good fixability, tricarboxylic or higher carboxylic acids (trimerits) It is preferable to use an acid or an acid anhydride thereof in combination.

Further, when a toner is prepared using an emulsion polymerization aggregation method, the emulsion particle size in the dispersion becomes large, and it may be difficult to adjust the toner diameter by aggregation. On the other hand, when it exceeds 20 constituent mol%, the crystallinity of the polyester resin is lowered, the melting temperature is lowered, and the storage stability of the image may be deteriorated. In addition, when a toner is produced using an emulsion polymerization aggregation method, the emulsion particle size in the dispersion may be too small to cause aggregation. In the present invention, “constituent mol%” refers to a percentage when each constituent component (carboxylic acid component, alcohol component) in the polyester resin is 1 unit (mol).

On the other hand, the alcohol component is preferably an aliphatic diol, such as 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-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14 -Aliphatic diols such as tetradecanediol, 1,18-octadecanediol, 1,20-eicosanediol, neopentyl glycol, diols, cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A, bisphenol A ethylene oxide adduct, bi Aromatic diols such as propylene oxide adduct of bisphenol A and the like. One or more of these polyhydric alcohols are used. Among these polyhydric alcohols, aromatic diols and alicyclic diols are preferable, and among these, aromatic diols are more preferable.

  Examples of the trivalent or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like. These may be used individually by 1 type and may use 2 or more types together.

On the other hand, as other components included as necessary, constituent components such as a diol component having a double bond may be mentioned.
If necessary, monovalent acids such as acetic acid and benzoic acid and monovalent alcohols such as cyclohexanol benzyl alcohol are also used for the purpose of adjusting the acid value and the hydroxyl value.

  Examples of the diol having a double bond include 2-butene-1,4-diol, 3-butene-1,6-diol, 4-butene-1,8-diol, and the like. On the other hand, examples of the diol having a sulfonic acid group include 1,4-dihydroxy-2-sulfonic acid benzene sodium salt, 1,3-dihydroxymethyl-5-sulfonic acid benzene sodium salt, and 2-sulfo-1,4. -Butanediol sodium salt and the like.

  In the case of adding an alcohol component other than these linear aliphatic diol components, the content in the alcohol component is preferably 1 component mol% or more and 20 component mol%, more preferably 2 component mol% or more and 10 component mol%. . When the content is less than 1 component mol%, pigment dispersion may be poor, the emulsified particle size may be increased, and adjustment of the toner diameter by aggregation may be difficult. On the other hand, when it exceeds 20 constituent mol%, the emulsion particle diameter may be too small, and the latex may be difficult to aggregate.

  The polyester resin production method is not particularly limited and can be produced by a general polyester polymerization method in which a carboxylic acid component and an alcohol component are reacted. Examples thereof include direct polycondensation and transesterification. Produced separately for different types. The molar ratio (acid component / alcohol component) when the acid component reacts with the alcohol component varies depending on the reaction conditions and the like, and cannot be generally stated, but is usually about 1/1.

The polyester resin can be produced at a polymerization temperature in the range of 180 ° C. or higher and 230 ° C. or lower. The reaction system is reduced in pressure as necessary, and reacted while removing water and alcohol generated during the condensation reaction. . When the monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a solubilizer and dissolved. In the polycondensation reaction, the dissolution auxiliary solvent is distilled off. If a monomer with poor compatibility is present in the copolymerization reaction, the monomer with poor compatibility and the monomer and the carboxylic acid component or alcohol component to be polycondensed are condensed in advance and then polycondensed together with the main component. Good.
The polyester resin particle dispersion is prepared by adjusting the acid value of the resin, emulsifying and dispersing using an ionic surfactant, and the like.

  Examples of the catalyst 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; zinc, manganese, antimony, titanium, tin, zirconium, germanium, and the like. Metal compounds; phosphorous acid compounds, phosphoric acid compounds, amine compounds, and the like.

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

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

  A styrene acrylic resin may also be used as the binder resin in the present embodiment. Examples of monomers that can be used for the synthesis of the styrene acrylic resin include styrenes such as styrene, parachlorostyrene, and α-methylstyrene: methyl acrylate, ethyl acrylate, n-propyl acrylate, and n-acrylate. -Esters having a vinyl group such as butyl, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate: acrylonitrile, methacrylonitrile Vinyl nitriles such as: Vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether: Vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isopropenyl ketone: Polyols such as ethylene, propylene and butadiene Monomers such as fins: and the like, homopolymers of these, copolymers obtained by combining two or more of these, and mixtures of two or more of polymers composed of these are used. It is done.

  Further, as the binder resin, epoxy resin, polyester resin, polyurethane resin, polyamide resin, cellulose resin, polyether resin, etc., non-vinyl condensation resin, or a mixture of these with the vinyl resin, or in the coexistence thereof Graft polymers and the like obtained when the vinyl monomer is polymerized with the above are used.

  The glass transition temperature of the binder resin used in the present invention is preferably 35 ° C. or higher and 100 ° C. or lower, and is 50 ° C. or higher and 80 ° C. or lower from the viewpoint of the balance between storage stability and toner fixing property. Is more preferable. When the glass transition temperature is less than 35 ° C., the toner tends to be blocked during the storage or in the developing machine (a phenomenon in which toner particles are aggregated into a lump). On the other hand, if the glass transition temperature exceeds 100 ° C., the fixing temperature of the toner becomes high, which is not preferable.

The softening point of the binder resin is preferably in the range of 80 ° C. or higher and 130 ° C. or lower. More preferably, it is the range of 90 degreeC or more and 120 degrees C or less. When the softening point is 80 ° C. or lower, the toner and the image stability of the toner after fixing and during storage are significantly deteriorated. On the other hand, when the softening point is 130 ° C. or higher, the low-temperature fixability is deteriorated.
The softening point of the amorphous resin is measured by a flow tester (manufactured by Shimadzu Corporation: CFT-500C), preheating: 80 ° C./300 sec, plunger pressure: 0.980665 MPa, die size: 1 mmφ × 1 mm, heating rate: 3. An intermediate temperature between the melting start temperature and the melting end temperature under the condition of 0 ° C./min.

<Release agent>
The toner of this embodiment may contain a release agent.
The release agent used in the toner of the present invention is preferably a substance having a main maximum peak measured in accordance with ASTM D3418-8 in the range of 50 ° C. or higher and 140 ° C. or lower. If the main maximum peak is less than 50 ° C., offset may easily occur during fixing. On the other hand, if the temperature exceeds 140 ° C., the fixing temperature becomes high, and the glossiness may be impaired due to insufficient smoothness of the image surface.
For the measurement of the main maximum peak, for example, DSC-7 manufactured by Perkin Elmer is used. The temperature correction of the detection part of this apparatus uses the melting point of indium and zinc, and the correction of heat quantity uses the heat of fusion of indium. For the sample, an aluminum pan is used, an empty pan is set for control, and the measurement is performed at a heating rate of 10 ° C./min.

Specific examples of the release agent include low molecular weight polyolefins such as polyethylene, polypropylene and polybutene, silicones having a softening point by heating, fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide and stearic acid amide. Plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil, animal waxes such as beeswax, montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, etc. Minerals, petroleum-based waxes, and modified products thereof can be used.
These release agents are dispersed in water together with ionic surfactants, polymer electrolytes such as polymer acids and polymer bases, and heated with a homogenizer or pressure discharge type disperser that can be heated to the melting point or higher and subjected to strong shearing. A release agent dispersion containing release agent particles having a particle diameter of 1 μm or less is prepared.

<Colorant>
The toner of this embodiment contains a colorant. As the colorant, a pigment is preferable.
1. Pigment Carbon black, magnetic powder, etc. are used as the black pigment. Examples of yellow pigments include Hansa Yellow, Hansa Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR, Slen Yellow, Quinoline Yellow, and Permanent Yellow NCG. Red pigments include Bengala, Watch Young Red, Permanent Red 4R, Resol Red, Brilliantamine 3B, Brilliantamine 6B, Dupont Oil Red, Pyrazolone Red, Rhodamine B Lake, Lake Red C, Rose Bengal, Eoxin Red, Alizarin Lake Etc. Blue pigments include bitumen, cobalt blue, alkali blue rake, Victoria blue rake, fast sky blue, indanthrene blue BC, aniline blue, ultramarine blue, calco oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite green oxare. Rate and so on.
Moreover, these may be used independently, may mix 2 or more types, and may be used in the state of a solid solution.

In addition, a colorant that has been surface-modified with rosin, polymer, or the like is also used. The surface-modified colorant is stabilized in the colorant dispersion, and after the colorant is dispersed to the desired average particle size in the colorant dispersion, it is mixed with the resin particle dispersion. At this time, the colorants are not aggregated even in the aggregated particle forming step and the like, which is advantageous in that a good dispersion state is maintained. On the other hand, the colorant that has undergone an excessive surface modification treatment may be released without agglomerating with the resin particles in the aggregated particle forming step. For this reason, the surface modification treatment is performed under selected optimum conditions.
Examples of the polymer used for the surface treatment of the colorant include acrylonitrile polymer and methyl methacrylate polymer.

  The conditions for surface modification are generally a polymerization method in which a monomer is polymerized in the presence of a colorant (pigment), a colorant (pigment) is dispersed in a polymer solution, and the solubility of the polymer is lowered to reduce the colorant (pigment). ) A phase separation method that precipitates on the surface is used.

These colorants are dispersed by a known method, and for example, a rotary shear type homogenizer, a media type dispersing machine such as a ball mill, a sand mill, or an attritor, a high-pressure opposed collision type dispersing machine, or the like is preferably used.
These colorants are dispersed in an aqueous solvent using a polar ionic surfactant and a homogenizer as described above to produce a colorant particle dispersion.
The content of the colorant is preferably in the range of 1% by mass to 20% by mass with respect to the entire toner particles.

<Other additive components>
When the toner of this embodiment is used as a magnetic toner, magnetic powder is contained. Examples of the magnetic powder used here include metals such as ferrite, magnetite, reduced iron, cobalt, nickel, and manganese, alloys, or these metals. And the like. Furthermore, various charge control agents that are usually used, such as quaternary ammonium salts, nigrosine compounds and triphenylmethane pigments, may be added as necessary.

<External additive>
The toner of this embodiment contains an external additive. The external additive includes polytetrafluoroethylene particles having an average particle diameter of 100 nm or more and 500 nm or less, and monodispersed spherical silica particles having an average particle diameter of 80 nm or more and 200 nm or less. Included in the state.
1. Polytetrafluoroethylene particles The PTFE particles used in the present embodiment are not particularly limited as long as the average particle size is 100 nm or more and 500 nm or less, and are preferably particles having an average particle size of 200 m or more and 400 nm or less. PTEF particles having the above particle diameter are produced by an emulsion polymerization method, and are also available as commercial products (for example, Lubron L-2 manufactured by Daikin Industries, Ltd.).
The average particle diameter of the polytetrafluoroethylene particles corresponds to the image area of the PTFE particles by performing observation of 100 fields (50000 times) using a scanning electron microscope (S-4700 type, manufactured by Hitachi, Ltd.). It is measured by approximating the particles as circles, measuring the particle size (average value of major axis and minor axis) at 1000 locations, and taking the average value as the number average primary diameter of PTFE particles.
The composition of the PTFE particles according to this embodiment is preferably a tetrafluoroethylene homopolymer, but may contain, for example, about 10% by weight or less of vinylidene fluoride, monofluoroethylene, and the like.

The polytetrafluoroethylene particles are contained in the toner of the present embodiment in a state of adhering to the surface of the toner particles, but the adhering to the surface of the toner particles can be achieved by adding a shearing force in a dry state to the toner particle surface. Good. Specific conditions at this time are performed by means for applying a high shearing force (for example, stirring at a high rotational speed using a Henschel mixer).
In this case, the addition amount of the polytetrafluoroethylene particles is preferably 0.1 parts by mass or more and 1 part by mass or less with respect to 100 parts by mass of the toner particles from the viewpoint of reducing adhesion of the toner particles. More preferably, it is 1 part by mass or more and 0.6 part by mass or less.
At the time of particle adhesion to the toner particle surface, a PTFE particle adheres firmly to the toner particle by applying a shearing force. At this time, the PTFE particle adheres in a deformed state under the influence of the shearing force. The shape factor of the attached PTFE particles is preferably 110 or more and 180 or less, and more preferably 120 or more and 160 or less. It is confirmed that the PTFE particles adhered to the surface of the toner particles are firmly adhered to the surface of the toner particles by having the described shape.

In addition, the said shape factor (SF1) is calculated | required by following formula (1) here.
SF1 = (ML ² / A) × (π / 4) × 100 (1)
In the above formula (1), ML represents the absolute maximum length of the toner particles, and A represents the projected area of the toner particles.

The SF1 is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image using an image analyzer, and is calculated as follows, for example. That is, the optical microscope image of the toner spread on the surface of the slide glass is taken into a Luzex image analyzer through a video camera, the maximum length and the projected area of 500 or more toner particles are obtained, and calculated by the above equation (2). It is obtained by calculating the average value.
The ratio of the number of toners with SF1 of less than 125 and more than 135 is obtained as the ratio of the number of toners in each shape factor range from the SF1 values of 500 particles measured as described above.

Preferably, under the above conditions, the initial toner of the present embodiment in which the polytetrafluoroethylene particles are firmly attached to the toner particle surfaces is subjected to ultrasonic treatment in which an ultrasonic vibration having an output of 20 W and a frequency of 20 kHz is applied for 1 minute in an aqueous dispersion. The amount of the polytetrafluoroethylene particles adhering without being detached from the toner particles when the operation is performed is 50% by mass or more and 100% by mass or less of the polytetrafluoroethylene particle adhering amount before the ultrasonic treatment. Cost.
Thus, even after the ultrasonic treatment, the PTFE particles remain on the surface of the toner particles by 50% by mass or more of the initial adhesion amount, so that the excellent effect of the present embodiment is expressed. Is 60 mass% or more and 100 mass% or less.

Examples of the water-based dispersion medium in which toner particles are dispersed in this adhesion test include polyoxyethylene octyl phenyl ether (Wako Pure Chemical Industries).
As a test method, first, 0.1 L of a 0.2 mass% surfactant aqueous solution as an aqueous dispersion medium was put in an ultrasonic treatment apparatus (Ultrasonic Generator model US-300TCVP (manufactured by Nippon Seiki Co., Ltd.)), and then there. 5 g of initial toner particles were added, and ultrasonic vibration with an output of 20 W and a frequency of 20 kHz was applied for 1 minute. Thereafter, the floating external additive (PTFE particles) is removed from the toner surface and recovered, and the toner particles are taken out and separated from the polytetrafluoroethylene particles and the toner particles. Thereafter, fluorescent X-ray measurement is performed, and the adhesion amount of the remaining polytetrafluoroethylene particles is measured from the difference from the initial value, and the ratio of the remaining particles is calculated.

2. Monodispersed spherical silica particles In this embodiment, the second external additive includes monodispersed spherical silica particles having an average particle diameter of 80 nm or more and 200 nm or less, and these particles are also contained in a state of being adhered to the toner particle surface. In the present invention, the “monodispersed spherical silica” refers to silica particles having a true specific gravity of 1.4 to 1.9 and a volume average particle size of 80 to 200 nm and obtained by a sol-gel method.
Here, the addition ratio of the polytetrafluoroethylene particles and the content ratio of the monodispersed spherical silica particles will be described. The added amount of the monodispersed spherical silica is 0.5 mass relative to 1 part by mass of the polytetrafluoroethylene particles. Part to 30 parts by mass, more preferably 1 part to 25 parts by mass.
In the present embodiment, the production method of monodispersed spherical silica is not particularly limited, but is preferably subjected to surface hydrophobization treatment from the viewpoint of effect. In addition, as a monodispersed spherical silica, a commercial item (for example, X24-9163A made by Shin-Etsu Chemical Co., Ltd.) etc. can be used. The average particle size is more preferably from 100 nm to 160 nm.

The hydrophobic treatment is performed by immersing monodispersed spherical silica particles in a hydrophobic treatment agent. Although there is no restriction | limiting in particular as said hydrophobic treatment agent, For example, a silane coupling agent, silicone oil, a titanate coupling agent, an aluminum coupling agent etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, silane coupling agents are preferable.
As the silane coupling agent, for example, any type of chlorosilane, alkoxysilane, silazane, and a special silylating agent can be used. Specifically, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, Methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltriethoxysilane, decyltrimethoxysilane, hexamethyldisilazane, N, O- (bistrimethylsilyl) acetamide, N, N- ( Trimethylsilyl) urea, tert-butyldimethylchlorosilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane , Γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercapto Examples thereof include propyltrimethoxysilane and γ-chloropropyltrimethoxysilane.
The monodispersed spherical silica particles may be added to the toner particle surfaces by applying a shearing force in a dry state.

<Toner particle production method>
As a method for producing the toner, for example, after preparing a resin particle dispersion by agglomeration and coalescence (emulsion polymerization, forced emulsification, phase inversion emulsification, etc.) and a colorant dispersion in which a colorant is dispersed in a solvent, , These are mixed to form an agglomerate corresponding to the particle size of the toner, and then heated to fuse and coalesce into a toner, and a suspension polymerization method (release agent, colorant, etc. is required) The component used according to the method is suspended together with a polymerizable monomer that forms a binder resin such as a crystalline resin, and the polymerizable monomer is polymerized to form a toner). A compound having an ionic dissociation group, a binder resin such as a crystalline resin, and a toner constituent material such as a release agent are dissolved in an organic solvent, dispersed in an aqueous solvent in a suspended state, and then the organic solvent is removed. And a wet manufacturing method such as a toner manufacturing method).

Hereinafter, an aggregation / unification method will be described as an example of a toner manufacturing method according to the present exemplary embodiment.
The toner manufacturing method in the present embodiment includes, for example, a resin particle dispersion adjusting step for adjusting a resin particle dispersion in which resin particles are dispersed, and a colorant particle dispersion for adjusting a colorant particle dispersion in which colorant particles are dispersed. A liquid adjustment step, a mixed solution adjustment step of mixing a resin particle dispersion and a colorant particle dispersion to adjust a mixed solution containing the resin particles and the colorant particles, and an aggregated particle in which the resin particles and the colorant particles are aggregated An agglomerated particle adjusting step for adjusting, and an aggregating / unifying step of fusing and coalescing the aggregated particle dispersion in which the agglomerated particles are dispersed to a temperature higher than the glass transition temperature of the resin particles.
Moreover, you may include other processes, such as the mold release agent particle dispersion liquid adjustment process which adjusts the mold release agent particle dispersion liquid which disperse the mold release agent particle as needed.
The toner according to the exemplary embodiment includes toner particles in an acidic or alkaline aqueous medium such as agglomeration and coalescence method, suspension polymerization method, dissolution suspension granulation method, dissolution suspension method, and dissolution emulsion aggregation aggregation method. Although it is suitable to manufacture by the wet manufacturing method to produce | generate, the aggregation coalescence method is especially preferable.

Hereinafter, the details of the production method by agglomeration and combination will be described.
The toner manufacturing method according to the present embodiment includes a resin particle dispersion in which first particle particles having a particle diameter of 1 μm or less, a colorant particle dispersion in which colorant particles are dispersed, and a release agent particle are dispersed. A first aggregating step of mixing the released release agent particle dispersion to form core agglomerated particles including the first resin particles, the colorant particles, and the release agent particles; and the surface of the core agglomerated particles Forming a shell layer containing the second resin particles to obtain core / shell aggregate particles, and the core / shell aggregate particles as the first resin particles or the glass transition of the second resin particles. It is characterized by including at least a fusion / union step of fusing and uniting by heating above the temperature.
By producing the toner using the toner production method, the content of the release agent can be easily controlled.

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

Next, the resin particle dispersion, the colorant particle dispersion, and the release agent particle dispersion are mixed, and the first resin particles, the colorant particles, and the release agent particles are heteroaggregated to obtain a desired toner diameter. Aggregated particles (core aggregated particles) including first resin particles, colorant particles, and release agent particles having a close diameter are formed.
In the second aggregating step, the second resin particles are adhered to the surface of the core agglomerated particles obtained in the first aggregating step by using a resin particle dispersion containing the second resin particles, and the desired thickness is obtained. By forming the coating layer (shell layer), aggregated particles (core / shell aggregated particles) having a core / shell structure in which a shell layer is formed on the surface of the core aggregated particles are obtained. In addition, the 2nd resin particle used in this case may be the same as the 1st resin particle, and may differ.
The particle diameters of the first resin particles, the second resin particles, the colorant particles, and the release agent particles used in the first and second aggregating steps are adjusted to a desired value for the toner diameter and the particle size distribution. In order to facilitate this, it is preferably 1 μm or less, and more preferably in the range of 100 nm to 300 nm.

In the first aggregating step, the balance of the amounts of the two polar ionic surfactants (dispersants) contained in the resin particle dispersion and the colorant particle dispersion can be shifted in advance. For example, an inorganic metal salt such as calcium nitrate or a polymer of an inorganic metal salt such as barium sulfate is ionically neutralized and heated below the glass transition temperature of the first resin particles to form core agglomerated particles. Is made.
In this case, in the second flocculation step, the resin particle dispersion treated with the polarity and amount of dispersant that compensates for the deviation in the balance between the two polar dispersants described above is placed in a solution containing core aggregated particles. Further, if necessary, the core / shell aggregated particles are produced by heating slightly below the glass transition temperature of the core aggregated particles or the second resin particles used in the second aggregation step as necessary. In addition, the 1st and 2nd aggregation process may be repeatedly performed in multiple steps stepwise.

Next, in the fusion / union process, the core / shell aggregated particles obtained through the second aggregation process are used as a first or second resin particle contained in the core / shell aggregated particles in a solution. The toner is obtained by heating to above the glass transition temperature (if the resin type is two or more, the glass transition temperature of the resin having the highest glass point transition temperature), fusing and coalescence.
After completion of the fusion / unification process, the toner formed in the solution is dried through a known washing process, solid-liquid separation process, and drying process to obtain a toner.
In addition, it is preferable that the washing | cleaning process performs substitution washing | cleaning by ion-exchange water fully from a charging point. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration, and the like are preferably used from the viewpoint of productivity. Further, although the drying process is not particularly limited, freeze drying, flash jet drying, fluidized drying, vibration fluidized drying and the like are preferably used from the viewpoint of productivity.

<Adhesion of external additives>
After the toner particles are produced in this manner, the toner of this embodiment is obtained by attaching the two types of external additives to the surface of the toner particles.
As described above, the method for attaching the polytetrafluoroethylene particles and the monodispersed spherical silica particles to the toner particles may be applied by applying a shearing force in a dry state. From the viewpoint of the effect, the PTFE particles are first attached. After the deposition, it is preferable to deposit the monodisperse spherical silica particles. First, when PTFE particles are firmly attached to the toner particle surface so that the shape factor of the particles is 110 or more and 120 or less, and then monodispersed spherical silica particles are attached, the PTFE particles have a low surface due to the material. Because of the friction coefficient, the monodispersed spherical silica particles added later do not adhere to the surface of the PTFE particles, and adhere to the toner particle surfaces in the gap regions (regions where no PTFE particles are present) of the PTFE particles. Thereby, due to the low friction coefficient and elasticity of the polytetrafluoroethylene particles, the monodispersed spherical silica particles excellent in the fluidity imparting function existing between them are less susceptible to external impact, and the detachment is suppressed, Together, the effects of these two external additives effectively suppress aggregation of toner particles and non-electrostatic adhesion to the apparatus.

The developer for developing an electrostatic charge image contains the toner for developing an electrostatic charge image of the present embodiment.
The developer containing the electrostatic image developing toner of the present embodiment may contain other components depending on the purpose.
Specifically, when the toner of this embodiment is used alone, it becomes a one-component electrostatic image developing developer, and when used in combination with a carrier, it becomes a two-component electrostatic image developing developer. The toner concentration in the two-component developer is preferably in the range of 1% by mass to 10% by mass.

  Here, the carrier is not particularly limited, and examples thereof include known carriers. For example, the core material described in JP-A-62-39879, JP-A-56-11461 or the like is coated with a resin layer. A known carrier such as a prepared carrier (resin-coated carrier) is used.

Examples of the core material of the resin-coated carrier include moldings such as iron powder, ferrite, and magnetite, and the average diameter is about 30 μm or more and 200 μm or less.
The electrical resistance of the carrier core material is preferably 1 × 10 ^7.5 Ω · cm or more and 1 × 10 ^9.5 Ω · cm or less.
Examples of the coating resin for forming the coating layer include styrenes such as styrene, parachlorostyrene, and α-methylstyrene, methyl acrylate, ethyl acrylate, n-propyl acrylate, lauryl acrylate, and 2-ethylhexyl acrylate. , Α-methylene fatty acid monocarboxylic acids such as methyl methacrylate, n-propyl methacrylate, lauryl methacrylate and 2-ethylhexyl methacrylate, nitrogen-containing acrylics such as dimethylaminoethyl methacrylate, vinyl nitriles such as acrylonitrile and methacrylonitrile Vinyl pyridines such as 2-vinyl pyridine and 4-vinyl pyridine, vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether, vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone and other vinyl ethers. Nyl ketones, olefins such as ethylene and propylene, homopolymers such as vinyl-based fluorine-containing monomers such as vinylidene fluoride, tetrafluoroethylene and hexafluoroethylene, or copolymers comprising two or more monomers, methyl silicone, Examples thereof include silicones such as methylphenyl silicone, polyesters containing bisphenol and glycol, epoxy resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, polycarbonate resins and the like. These resins may be used alone or in combination of two or more.

  The amount of the coating resin is preferably in the range of 0.1 to 10 parts by mass and more preferably in the range of 0.5 to 3.0 parts by mass with respect to 100 parts by mass of the core material. For the production of the carrier, for example, a heating kneader, a heating Henschel mixer, a UM mixer, or the like can be used. Depending on the amount of the coating resin, a heating fluidized rolling bed, a heating kiln, or the like may be used. . The mixing ratio of the toner and the carrier in the electrophotographic developer is not particularly limited, and is selected according to the purpose.

<Image forming apparatus, toner cartridge>
The image forming apparatus of the present embodiment includes an image carrier, a charging unit that charges the surface of the image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the charged surface of the image carrier, Developing means for developing the electrostatic latent image with the developer to form a toner image, transfer means for transferring the toner image to the surface of the recording medium, and fixing for fixing the toner image transferred to the surface of the recording medium And a toner removing means for removing toner remaining on the surface of the image carrier after transfer, wherein the developer contains the toner of the present embodiment described above. Since the image forming apparatus of this embodiment uses the developer of this embodiment, a high-quality image is formed over a long period of time.

  The image forming apparatus according to the present exemplary embodiment may further include a residual toner collecting / supplying unit that collects the residual toner removed by the toner removing unit and supplies the collected residual toner to the developing unit. In the present embodiment, since the developer of the present embodiment is used as the developer, the durability of the toner is high, and a high-quality image can be formed over a long period of time even when the toner is reused.

  Hereinafter, the image forming apparatus of this embodiment will be described in detail with reference to the drawings. In addition, the same code | symbol is provided to the member which has the substantially same function throughout all the drawings, and the overlapping description may be abbreviate | omitted.

  FIG. 1 is a configuration diagram illustrating an image forming apparatus according to the present embodiment. The image forming apparatus shown in FIG. 1 is a quadruple tandem full-color image forming apparatus. Each color of yellow (Y), magenta (M), cyan (C), and black (K) based on the color-separated image data. Are provided with first to fourth image forming units 10Y, 10M, 10C, and 10K (image forming means) of an electrophotographic system for outputting the above image. These image forming units (hereinafter simply referred to as “units”) 10Y, 10M, 10C, and 10K are juxtaposed at a predetermined distance in the horizontal direction. 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 spaced apart from each other from the left to the right in the drawing. It is designed to travel in the direction toward 10K. The support roller 24 is biased in a direction away from the drive roller 22 by a spring or the like (not shown), and necessary tension is applied to the intermediate transfer belt 20 wound around 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, each of the developing devices (developing means) 4Y, 4M, 4C, and 4K of each unit 10Y, 10M, 10C, and 10K contains developer containing toner of four colors of yellow, magenta, cyan, and black. Yes. Further, toners of four colors, yellow, magenta, cyan, and black, stored in the toner cartridges 8Y, 8M, 8C, and 8K are supplied to the developing devices 4Y, 4M, 4C, and 4K, respectively.

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

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

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

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

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

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

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

  The intermediate transfer belt 20 onto which the four color toner images have been transferred in a multiple manner through the first to fourth units is disposed on the intermediate transfer belt 20, the support roller 24 in contact with the inner surface of the intermediate transfer belt 20, and the image holding surface side of the intermediate transfer belt 20. The secondary transfer roller 26 is formed to a secondary transfer portion. On the other hand, the recording medium P (transfer object) is fed at a predetermined timing into a gap where the secondary transfer roller 26 and the intermediate transfer belt 20 are pressed against each other via a supply mechanism, and a predetermined secondary transfer bias is supported. Applied to the roller 24. The transfer bias applied at this time 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 medium P is applied to the toner image, so The toner image is transferred onto the recording medium 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 medium P is sent to a fixing device (fixing means) 28, the toner image is heated, and the color-superposed toner image is melted and fixed on the recording medium P. The recording medium P on which the color image has been fixed is unloaded to 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 to the recording medium P via the intermediate transfer belt 20, but is not limited to this configuration, and the toner image is directly transferred from the photoconductor. It may be a structure that is transferred to a recording sheet.

  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 are attached to and detached from each other. The developing devices 4Y, 4M, 4C, and 4K each have their respective developing devices (colors). And a toner supply pipe (not shown). Further, when the amount of toner stored in the toner cartridge is low, this toner cartridge may be replaced.

<Process cartridge>
The process cartridge of this embodiment includes at least a developer holder, and uses the developer of this embodiment as a developer. In addition, an image carrier, a charging unit, a toner removing unit, and the like may be provided.

  FIG. 2 is a schematic configuration diagram showing a preferred example of a process cartridge containing the developer according to the present embodiment. The process cartridge 200 includes a photosensitive member 107 (latent image holding member), a charging roller 108, a developing device 111 including a developer holding member 111A, a photosensitive member cleaning device 113 (toner removing unit), and an opening 118 for exposure. , And the opening 117 for static elimination exposure is combined and integrated using the mounting rail 116.

  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. Reference numeral 300 denotes a recording paper (recording medium).

  The process cartridge shown in FIG. 2 includes a charging roller 108, a developing device 111, a cleaning device (cleaning means) 113, an opening 118 for exposure, and an opening 117 for static elimination exposure. May be combined selectively. In the process cartridge of the present embodiment, if the developer holding member 111A is provided, the photosensitive member 107, the charging roller 108, the developing device 111, the cleaning device 113, the opening 118 for exposure, and the discharge exposure. You may provide at least 1 sort (s) selected from the group comprised from the opening part 117. FIG.

<Toner cartridge>
The toner cartridge according to this embodiment is detached from an image forming apparatus having at least a developing unit, and stores a developer containing toner to be supplied to the toner image forming unit. The toner is in the form. It should be noted that at least the toner may be stored in the toner cartridge of the present embodiment, and for example, a developer may be stored 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 freely attached and detached, the storability is maintained even in the toner cartridge in which the container is miniaturized by using the toner cartridge containing the toner of the present embodiment. Can be fixed at low temperature while maintaining high image quality.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited only to the Example shown below.
In the examples, “parts” and “%” mean “parts by mass” and “% by mass” unless otherwise specified.
The particle size distribution measurement in the present invention will be described.
A Coulter Multisizer-II type (manufactured by Beckman Coulter, Inc.) was used as a measuring apparatus, and ISOTON-II (manufactured by Beckman Coulter, Inc.) was used as an electrolyte.
As a measurement method, 1.0 mg of a measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate, as a dispersant. This was added to 100 ml of the electrolytic solution to prepare an electrolytic solution in which the sample was suspended.
The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment for 1 minute with an ultrasonic disperser, and the particle size distribution of particles of 1 to 30 μm is measured by the Coulter Multisizer-II type using an aperture diameter of 50 μm. Average distribution and number average distribution are obtained. The number of particles to be measured was 50,000.

Moreover, when the particle | grains to measure in this invention are less than 2 micrometers, it measured using the laser diffraction type particle size distribution measuring apparatus (LA-700: made by Horiba, Ltd.). As a measurement method, a sample in a dispersion is adjusted to have a solid content of about 2 g, and ion exchange water is added thereto to make about 40 ml. This is put into the cell until an appropriate concentration is reached, waits for about 2 minutes, and is measured when the concentration in the cell becomes almost stable. The obtained volume average particle diameter for each channel was accumulated from the smaller volume average particle diameter, and the volume average particle diameter was determined to be 50%.
When measuring powders such as external additives, 2 g of a measurement sample is added to 50 ml of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate, and dispersed for 2 minutes with an ultrasonic disperser (1000 Hz). Then, a sample was prepared and measured by the same method as the above-mentioned dispersion.

  In the electrostatic charge developing toner of the present invention, the specific molecular weight distribution is obtained under the following conditions. GPC uses “HLC-8120GPC, SC-8020 (manufactured by Tosoh Corporation)”, and the column uses two “TSKgel, SuperHM-H (6.0 mm ID × 15 cm, manufactured by Tosoh Corporation)” THF (tetrahydrofuran) was used as an eluent. As experimental conditions, the sample concentration was 0.5%, and the flow rate was 0.6 ml / min. The experiment was conducted using a sample injection amount of 10 μl, a measurement temperature of 40 ° C., and an IR detector. The calibration curve is “polystylen standard sample TSK standard” manufactured by Tosoh Corporation: “A-500”, “F-1”, “F-10”, “F-80”, “F-380”, “A-2500”. ”,“ F-4 ”,“ F-40 ”,“ F-128 ”, and“ F-700 ”.

<Production of toner particles>
-Preparation of polyester resin dispersion-
・ Terephthalic acid 30mol%
・ Fumaric acid 70mol%
・ Bisphenol A ethylene oxide 2 mol adduct 20 mol%
・ Bisphenol A propylene oxide adduct 80mol%

The above monomer is charged into a 5 liter flask equipped with a stirrer, nitrogen inlet tube, temperature sensor, and rectifying tower, and the temperature is raised to 190 ° C. over 1 hour, and the reaction system is uniformly stirred. After confirming the above, 1.2 parts by mass of dibutyltin oxide was added. Further, while distilling off the water produced, it took 6 hours from the same temperature to increase the temperature to 240 ° C., and continued the dehydration condensation reaction at 240 ° C. for another 3 hours. The acid value was 12.0 mg / KOH, weight average molecular weight A polyester resin of 9700 was obtained.
Subsequently, this was transferred in a molten state to Cavitron CD1010 (manufactured by Eurotech Co., Ltd.) at a rate of 100 g / min. Separately prepared aqueous medium tank is filled with 0.37 wt% diluted ammonia water diluted with ion-exchanged water with reagent-exchanged water, and heated at 120 ° C with a heat exchanger at a rate of 0.1 liter per minute. At the same time as the above amorphous polyester resin 1 melt, it was transferred to Cavitron CD1010 (manufactured by Eurotech Co., Ltd.).
The Cavitron was operated under conditions of a rotor rotation speed of 60 Hz and a pressure of 5 kg / cm ² to obtain a polyester resin dispersion containing an amorphous polyester resin having an average particle size of 0.16 μm and a solid content of 30 parts by mass.

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

-Preparation of release agent dispersion-
-Paraffin wax HNP9 (melting point 75 ° C: manufactured by Nippon Seiki) 45 parts by mass-Cationic surfactant Neogen RK (Daiichi Kogyo Seiyaku) 5 parts by mass-Ion-exchanged water 200 parts by mass After sufficiently dispersing with IKA Ultra Turrax T50, it was dispersed with a pressure discharge type gorin homogenizer to obtain a wax dispersion having a center diameter of 200 nm and a solid content of 20.0 parts by mass.

-Production of toner particles 1-
-Polyester resin tree dispersion 292.2 parts by mass-Colorant dispersion 26.3 parts by mass-Release agent dispersion 34 parts by mass

The above was thoroughly mixed and dispersed with an Ultra Turrax T50 in a round stainless steel flask. Next, 0.25 part by mass of polyaluminum chloride was added thereto, and the dispersion operation was continued with an ultra turrax. The flask was heated to 48 ° C. with stirring in an oil bath for heating. After maintaining at 48 ° C. for 60 minutes, 70.0 parts by mass of the polyester resin dispersion was gently added thereto.
Thereafter, the pH of the system was adjusted to 9.0 with a 0.5 mol / l sodium hydroxide aqueous solution, and then the stainless steel flask was sealed, and heated to 96 ° C. while continuing to stir using a magnetic seal for 5 hours. Retained.
After completion of the reaction, the mixture was cooled, filtered, sufficiently washed with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed in 1 L of ion exchange water at 40 ° C., and stirred and washed at 350 rpm for 18 minutes.

This was repeated five more times, and when the pH of the filtrate became 7.5 and the electric conductivity was 7.0 μS / cmt, solid-liquid separation was performed using No5A filter paper by Nutsche suction filtration. Vacuum drying was then continued for 12 hours.
When the particle diameter at this time was measured, the volume average diameter D50 was 6.1 μm. Moreover, it was observed that the shape factor of the particle | grains calculated | required by the shape observation by Luzex was 128.

<External additive>
According to the following production method, the composition shown in Table 1 below and an external additive having a particle shape were prepared.
(Polytetrafluoroethylene particles)
Table 1 below shows “PTFE”.
-Preparation of external additive G-
An autoclave equipped with a stainless steel anchor-type stirring blade and temperature control jacket is charged with deionized water, ammonium perfluorooctanoate, and paraffin wax, and heated with nitrogen gas and tetrafluoroethylene (hereinafter referred to as TFE). Was replaced with TFE, and the internal temperature was kept at 80 ° C. while stirring at 250 rpm. While the ammonium persulfate aqueous solution and the disuccin peroxide aqueous solution were injected, TFE was supplied so that the pressure in the tank became constant. After stirring for 60 minutes from the start of polymerization, the supply and stirring of TFE are stopped, and the reaction is terminated. An aqueous solution of hydroperfluorononanoic acid ammonium is injected into the obtained latex, and warm water is added and adjusted so that the temperature in the tube becomes 50 ° C. Next, at the same time as adding nitric acid, coagulation was started at a stirring speed of 250 rpm. After the polymer and water were separated, the mixture was stirred for 1 hour, then water was removed and dried to obtain an external additive G having an average particle size of 350 nm. Obtained.

-Preparation of external additive H-
In the preparation of the external additive G, the external additive H having an average particle diameter of 100 nm was obtained by the same production method as the external additive G, except that the stirring was started for 40 minutes from the start of polymerization and the stirring speed at the time of coagulation was 500 rpm. .

-Preparation of external additive I-
In the preparation of the external additive G, the external additive I having an average particle diameter of 500 nm was obtained by the same production method as the external additive G, except that the stirring was started for 90 minutes from the start of polymerization and the stirring speed at the time of coagulation was 100 rpm. .

-Preparation of external additive J-
In the preparation of the external additive G, the external additive J having an average particle size of 800 nm was obtained by the same production method as the external additive G, except that the stirring was started for 150 minutes from the start of polymerization and the stirring speed at the time of coagulation was 500 rpm. .

(Monodispersed spherical silica particles)
Table 1 below shows “silica”.
-Preparation of external additive A-
150 parts of tetramethoxysilane is stirred at 150 rpm while 150 parts of 25% by weight ammonia water is added dropwise at 30 ° C. over 3 hours in the presence of 100 parts of ion-exchanged water and 100 parts of 25% by weight alcohol. The silica sol suspension obtained by this reaction is centrifuged, separated into wet silica gel, alcohol and aqueous ammonia, and the separated wet silica gel is dried at 120 ° C. for 2 hours, and then 100 parts of silica and 500 parts of ethanol are mixed. Was put into an evaporator and stirred for 15 minutes while maintaining the temperature at 40 ° C. Next, 10 parts of dimethyldimethoxysilane was added to 100 parts of silica, and the mixture was further stirred for 15 minutes. Finally, the temperature was raised to 90 ° C. and ethanol was dried under reduced pressure. The treated product was taken out and further vacuum dried at 120 ° C. for 30 minutes. The dried silica was pulverized to obtain an external additive A having an average particle size of 130 nm.

-Preparation of external additive B-
In the preparation of the external additive A, 25% by weight of aqueous ammonia was averaged by the same production method as the external additive A, except that 150 parts of aqueous ammonia was added dropwise over 4 hours and stirred at 250 rpm. An external additive B having a particle size of 80 nm was obtained.

-Preparation of external additive C-
In the preparation of the external additive A, 25% by weight of aqueous ammonia was averaged by the same production method as the external additive A, except that 150 parts of aqueous ammonia was added dropwise over 3 hours and stirred at 100 rpm. An external additive C having a particle size of 200 nm was obtained.

-Preparation of external additive D-
Sodium silicate was added to pure water so that the silica concentration was 3%. After raising the temperature to 90, sulfuric acid and sodium silicate were added at a constant ratio while stirring at 200 rpm. After completion of the addition, sulfuric acid was further added to adjust the pH to 2, thereby terminating the reaction. The silica obtained by this reaction is repeatedly filtered and washed. The obtained dehydrated cake was vacuum-dried and then pulverized. The external additive D thus obtained had an average particle size of 80 nm.

-Preparation of external additive E-
In the production of external additive A, 25% by weight of ammonia water was averaged by the same production method as external additive A except that 150 parts of aqueous ammonia was added dropwise over 5 hours and stirred at 280 rpm. An external additive E having a particle size of 60 nm was obtained.

-Preparation of external additive F-
In the preparation of the external additive A, 25% by weight of aqueous ammonia was averaged by the same production method as the external additive A, except that 150 parts of aqueous ammonia was added dropwise over 1 hour and stirred at 80 rpm. An external additive F having a particle size of 500 nm was obtained.

(Hydrophobized titanium oxide particles)
-Preparation of external additive K-
Using ilmenite as an ore, TiO (OH) ₂ was produced by using a wet precipitation method in which iron powder was separated by dissolving in sulfuric acid and hydrolyzing TiSO ₄ to produce TiO (OH) _2. In the process of production of (OH) ₂ , dispersion adjustment and water washing were performed for hydrolysis and nucleation.
100 parts of TiO (OH) ₂ obtained was dispersed in 1000 ml of water, and 10 parts of decylsilane was added dropwise thereto while stirring at room temperature. Then, this was filtered and washed with water repeatedly. And the titanium oxide surface-treated with decylsilane was dried at 150 ° C. to produce an external additive K having a volume average primary particle size of 300 nm.

<Creation of carrier>
Ferrite particles (average particle size 50 μm, volume electric resistance 3 × 10 ⁸ Ω · cm) 100 parts by mass Toluene 14 parts by mass Perfluorooctylethyl acrylate / methyl methacrylate copolymer (copolymerization ratio 40:60, Mw = 50,000) 1.6 parts by mass carbon black (VXC-72; manufactured by Cabot Corporation) 0.12 parts by mass The above components except for the ferrite particles are dispersed with a stirrer for 10 minutes to prepare a film forming solution. The film forming solution and the ferrite particles are put into a vacuum degassing kneader and stirred at 60 ° C. for 30 minutes, and then the pressure is reduced to distill off the toluene to form a resin film on the surface of the ferrite particles. Manufactured.

<Developer preparation>
Example 1
0.4 parts of PTFE particles G are added to 100 parts of the toner particles 1, blended at 2500 rpm for 10 minutes with a Henschel mixer, and then 2 parts of silica particles A are added and blended at 1500 rpm for 15 minutes with a Henschel mixer. Thus, an electrostatic charge developing toner was obtained. Using a scanning electron microscope (FE-SEM, manufactured by Hitachi: S-5500), an image taken at a magnification of 100,000 times was scanned with an image analysis apparatus (manufactured by Nireco: Luzex AP) (FE-SEM, The shape factor of PTFE particles obtained by an image analyzer (manufactured by Nireco: Luzex AP) using an image taken at a magnification of 100,000 times using Hitachi (S-5500) was 159. 5 parts of the resulting electrostatic charge developing toner and 100 parts of the carrier were stirred for 10 minutes at 40 rpm using a V-blender to obtain an electrostatic charge developer.

(Example 2)
In the preparation of the developer, an electrostatic charge developer was obtained by the same production method as in Example 1 except that 0.5 part of PTFE particles H and 1.5 parts of silica particles A were added. The shape factor of the PTFE particles was 152.

(Example 3)
In the preparation of the developer, an electrostatic charge developer was obtained by the same production method as in Example 1 except that 0.3 part of PTFE particles I and 2.7 parts of silica particles A were added. The shape factor of the PTFE particles was 131.

Example 4
In the preparation of the developer, an electrostatic charge developer was obtained by the same production method as in Example 1 except that 0.4 part of PTFE particles G and 2.4 parts of silica particles B were added. The shape factor of the PTFE particles was 149.

(Example 5)
In the preparation of the developer, an electrostatic charge developer was obtained by the same production method as in Example 1 except that 0.4 part of PTFE particles G and 1.2 parts of silica particles C were added. The shape factor of the PTFE particles was 151.

(Example 6)
In the preparation of the developer, an electrostatic charge developer was obtained by the same production method as in Example 1 except that 0.1 part of PTFE particles G and 2.5 parts of silica particles A were added. The shape factor of the PTFE particles was 157.

(Example 7)
In the preparation of the developer, an electrostatic charge developer was obtained by the same production method as in Example 1 except that 1 part of PTFE particles G and 1 part of silica particles A were added. The shape factor of the PTFE particles was 142.

(Example 8)
In the preparation of the developer, an electrostatic charge developer was obtained by the same production method as in Example 1 except that 1 part of PTFE particles G and 0.5 part of silica particles A were added. The shape factor of the PTFE particles was 145.

Example 9
In the preparation of the developer, an electrostatic charge developer was obtained by the same production method as in Example 1 except that 0.15 parts of PTFE particles G and 4.5 parts of silica particles A were added. The shape factor of the PTFE particles was 154.

(Example 10)
To 100 parts of the toner particles 1, 0.8 parts of PTFE particles G are added, blended for 10 minutes at 1500 rpm with a Henschel mixer, then 3.2 parts of silica particles A are added, and 15 parts at 1500 rpm with a Henschel mixer. An electrostatic charge developer was obtained by the same production method as in Example 1 except that the blending was performed for a minute. The shape factor of the PTFE particles was 120.

(Example 11)
Add 100 parts of PTFE particles G to 100 parts of the toner particles 1, blend for 20 minutes at 2500 rpm with a Henschel mixer, add 4 parts of silica particles A, and blend for 15 minutes at 1500 rpm with a Henschel mixer. Except for the above, an electrostatic charge developer was obtained by the same production method as in Example 1. The shape factor of the PTFE particles was 159.

Example 12
In the preparation of the developer, an electrostatic charge developer was obtained by the same production method as in Example 1 except that 2 parts of PTFE particles G and 2 parts of silica particles A were added. The shape factor of the PTFE particles was 159.

(Comparative Example 1)
In the preparation of the developer, an electrostatic charge developer was obtained by the same production method as in Example 1 except that 0.4 part of PTFE particles G and 3.2 parts of silica particles D were added. The shape factor of the PTFE particles was 155.

(Comparative Example 2)
In the preparation of the developer, an electrostatic charge developer was obtained by the same production method as Example 1 except that 0.4 part of PTFE particles G and 2 parts of silica particles E were added. The shape factor of the PTFE particles was 130.

(Comparative Example 3)
In the preparation of the developer, an electrostatic charge developer was obtained by the same production method as in Example 1 except that 0.4 part of PTFE particles G and 2.4 parts of silica particles F were added. The shape factor of the PTFE particles was 152.

(Comparative Example 4)
In the preparation of the developer, an electrostatic charge developer was obtained by the same production method as in Example 1 except that 0.2 part of PTFE particles J and 1.8 parts of silica particles A were added. The shape factor of the PTFE particles was 132.

(Comparative Example 5)
0.4 parts of PTFE particles G are added to 100 parts of the toner particles 1, blended with a Henschel mixer at 800 rpm for 10 minutes, and then 2 parts of silica particles A are added, and blended at 600 rpm with a Henschel mixer for 15 minutes. Except for the above, an electrostatic charge developer was obtained by the same production method as in Example 1. The shape factor of the PTFE particles was 111.

(Comparative Example 6)
In the preparation of the developer, an electrostatic charge developer was obtained by the same production method as in Example 1 except that 0.2 part of PTFE particles G and 8 parts of silica particles A were added. The shape factor of the PTFE particles was 149.

(Comparative Example 7)
In the preparation of the developer, an electrostatic charge developer was obtained by the same production method as in Example 1 except that 0.4 part of hydrophobic titanium oxide particles K and 1.6 parts of silica particles A were added.

(Comparative Example 8)
In the preparation of the developer, the same process as in Example 1 was performed except that 0.4 part of PMMA particles L (particle size 200 nm, manufactured by Soken Chemical Co., Ltd.) and 1.6 parts of silica particles A were added. A charge developer was obtained.

<Evaluation of physical properties of toner>
(PTEF particle adhesion rate)
First, the PTFE particle adhesion amount of the obtained toner particles was measured by fluorescent X-ray.
Thereafter, 5 g of toner particles are weighed and dispersed in an aqueous dispersion (25 ° C.) of polyoxyethylene octyl phenyl ether (manufactured by Wako Pure Chemical Industries, Ltd.), and an ultrasonic generator (Ultrasonic Generator model US-300TCVP (Japan) Using a Seiki Co., Ltd.), ultrasonic treatment was performed by applying ultrasonic vibration with an output of 20 W and a frequency of 20 kHz for 1 minute.
After the treatment, the floating external additive (PTFE particles) is removed from the toner surface and collected. The toner particles are collected by filtration, and the collected floating PTFE particles and the collected toner are measured by fluorescent X-ray. From the difference in the amount of adhesion before and after the treatment, the residual rate of PTFE particles adhering to the surface of the toner particles of the following formula was determined. The results are listed in Table 2 below.
Here, a calibration curve is prepared using a sample whose PTFE particle content is known in advance, and the amount of adhering PTFE particles is obtained by fluorescent X-ray measurement of the toner before processing and the filtered toner.
Adhesion rate = (PTFE amount after ultrasonic treatment) / (PTFE amount before treatment) × 100

(Measurement of shape factor of PTFE particles adhering to the toner particle surface)
An image analysis device (manufactured by Nireco: manufactured by Nireco) using an electrostatic charge developing toner externally added by a Henschel mixer, with a scanning electron microscope (FE-SEM, Hitachi: S-5500). Using a scanning electron microscope (FE-SEM, Hitachi: S-5500) with Luzex AP), an image taken at a magnification of 100,000 times was obtained by an image analyzer (Nireco: Luzex AP).
Here, the shape factor (SF1) is obtained by the following equation (2).
SF1 = (ML ² / A) × (π / 4) × 100 (2)
In the above formula (2), ML represents the absolute maximum length of PTFE particles, and A represents the projected area of PTFE particles. The average value is obtained from the SF1 values of the 500 PTFE particles on the surface of the toner measured as described above.
The physical properties of these toners are shown in Table 2 below.

<Evaluation of toner performance>
(Recovery clogging evaluation)
The developability was evaluated using DocuCenter-III C4400 (Fuji Xerox Co., Ltd.). A toner amount of 6.0 g / m ² , C2 paper A4 (manufactured by Fuji Xerox Co., Ltd.) was used, and an electrophotographic society test chart No. Using 1-R 1993, an actual machine evaluation of 10,000 sheets was performed, and the presence or absence of clogging of the collected toner in the collecting machine was confirmed, and this was performed up to 50,000 sheets every 10,000 sheets. Evaluation was made according to the following evaluation criteria, and the evaluation was stopped when the mark became x.
The evaluation environment is performed at a temperature of 30 ° C. and a humidity of 85%, and the allowable range is 30000 sheets up to “◯”. The results are shown in Table 3 below.
<Evaluation criteria>
A: No occurrence of toner clogging in the collecting apparatus is confirmed. B: Toner clogging in the collecting apparatus is not confirmed, but there is toner adhering to the photoconductor that is not completely collected.
X: Toner clogging occurred in the recovery device

  From the results of the physical property values in Table 2 and the performance evaluation results in Table 3, the toner for electrostatic image development according to this embodiment is a toner in the collection system caused by aggregation of toner particles and adhesion to the apparatus as compared with the toner of the comparative example. It turns out that generation | occurrence | production of particle | grain clogging is suppressed more.

1Y, 1M, 1C, 1K, photoconductor (latent image carrier)
2Y, 2M, 2C, 2K, charging roller 3Y, 3M, 3C, 3K, laser beam (electrostatic latent image forming means)
3, exposure device 4Y, 4M, 4C, 4K, developing device (developing means)
5Y, 5M, 5C, 5K Primary transfer rollers 6Y, 6M, 6C, 6K, photoconductor cleaning device (toner removing means)
8Y, 8M, 8C, 8K Toner cartridge 10Y, 10M, 10C, 10K Unit 26 Secondary transfer roller (transfer means)
28 Fixing device (fixing means)
200 process cartridge,
P Recording paper (transfer object)

Claims (6)

Toner particles containing a binder resin and a colorant, polytetrafluoroethylene particles having an average particle diameter of 100 nm or more and 500 nm or less attached to the toner particle surface, and single particles having an average particle diameter of 80 nm or more and 200 nm or less attached to the toner particle surface. The amount of polytetrafluoroethylene particles added is 0.1 to 1 part by mass with respect to 100 parts by mass of toner particles, and 1 part by mass of polytetrafluoroethylene particles. On the other hand, the monodispersed spherical silica particles are 0.5 parts by mass or more and 30 parts by mass or less,
When ultrasonic treatment was performed in which an ultrasonic vibration with an output of 20 W and a frequency of 20 kHz was applied for 1 minute in an aqueous dispersion, the amount of polytetrafluoroethylene particles adhering without being detached from the toner particles was ultrasonicated. A toner for developing an electrostatic charge image, which is 50% by mass or more and 100% by mass or less of the previous polytetrafluoroethylene particle adhesion amount.   The electrostatic charge image developing toner according to claim 1, wherein the polytetrafluoroethylene particles attached to the toner particle surfaces have a shape factor of 120 or more and 160 or less.   The electrostatic image developing toner according to claim 1, which is obtained by attaching polytetrafluoroethylene particles to the surface of the toner particles and then attaching monodispersed spherical silica particles.   The toner for developing an electrostatic charge image according to any one of claims 1 to 3, wherein toner to be attached to and detached from an image forming apparatus including a developing unit and supplied to the developing unit is stored. Toner cartridge.   A process cartridge comprising a developing holder and containing an electrostatic charge image developing developer containing the electrostatic charge image developing toner according to any one of claims 1 to 3. A latent image carrier,
An electrostatic latent image forming means for forming an electrostatic latent image on the surface of the latent image holding member;
Developing means for developing the electrostatic latent image with a developer containing toner to form a toner image;
Transfer means for transferring the toner image formed on the latent image holding member to the surface of a recording medium;
Toner removing means for removing residual toner remaining on the surface of the latent image holding member,
The image forming apparatus according to claim 1, wherein the developer is an electrostatic charge image developing developer including the electrostatic charge image developing toner according to claim 1.

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