JP2006330689A - Electrostatic charge image developing toner and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner composition which prevents scumming from occurring by efficiently and uniformly performing charging, suppresses toner leakage of the supply toner due to a reset defect by overcharging of the toner on a developing roller and stripes on a conveyance surface due to electrostatic flocculation and makes it possible to obtain excellent image stability. <P>SOLUTION: The toner is formed by externally adding inorganic particulates to toner base particles having at least a binder resin and a colorant, in which at least one kind of the inorganic particulates are the inorganic particulates of a multi component oxide of 2 to 10 in relative dielectric constant measured at 1 Mhz and 10<SP>11</SP>Ωcm in volume resistivity. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a toner for developing an electrostatic latent image.
Further, the present invention relates to a toner and an image forming method suitable for an image forming apparatus having a developing device that presses a developing roller and a developer layer thickness regulating member to form a thin layer, and further having means for contact charging the latent image holding member. It is.
The present invention also relates to an electrostatic charge developing toner composition for use in a copying machine, a printer, etc., to which electrophotographic technology is applied, and an image forming method using the same, and in particular, a toner for supply toner due to a poor reset of toner on the developing roller The present invention relates to an electrostatic charge developing toner composition and an image forming method capable of suppressing leakage and streaking of a conveyance surface due to electrostatic aggregation and obtaining excellent image stability.

Conventionally, research and development on electrophotography has been carried out by various creative ideas and technical approaches. In electrophotography, an electrostatic latent image formed by charging and exposing the surface of a photoconductor is developed with a colored toner to form a toner image, and the toner image is transferred to a transfer material such as transfer paper. The image is formed by fixing with a heat roll or the like.
At present, there is a dry development method employed in electrophotography and electrostatic recording as an effective means. This dry development method includes a method using a two-component developer composed of a toner and a carrier, and a carrier. There is a method using a single-component developer that is not present.

First, a two-component developer system will be described.
This method is advantageous in terms of developer handling because the process up to developing the toner is carried through a carrier, and it is relatively stable and good when printing in a long life and high speed region is required. However, it is difficult to obtain images of constant quality over a long period of time because the carrier is easily deteriorated and the mixing ratio of the toner and the carrier is easily changed. There is a difficulty in downsizing, and in this respect, the one-component developer system is superior.

However, in recent years, the competitive area by these methods has increased in the flow from high quality, compactness, low cost, high speed, monochrome printing to color printing, and the range of choices has expanded from the user's point of view. It is coming. In connection with these, even in the former two-component system, lightness, compactness, operability including replacement, maintenance, and handling are important factors for office use.
Also, from the viewpoint of further speeding up, it has expanded to the printing area, and as a developer, both methods are pulverized from the viewpoints of toner diameter reduction, spheroidization, oilless fixing, etc. in conjunction with these requirements. The mounting of not only toner but also polymerized toner is increasing.

From these viewpoints, there is a growing demand for a developer that can make full use of the characteristics of the two-component method and can be applied to a wide range of printing speeds, and that is compatible with a long life, high image quality, and a compact process. .
With respect to the above requirements, the following problems are particularly mentioned as the two-component developer. (1) Increase in charge amount due to toner diameter reduction, change in chargeability due to durability, and increase in adhesion
(2) Changes in chargeability due to contamination of carriers and components
(3) Change in external additive adhesion on the toner surface

Various proposals have been made to solve the above problems.
For example, in Patent Document 1, as a description of a stain resistance index of a developer, the carrier surface is made of toner by adding needle-like inorganic powder and spherical inorganic powder whose fine particle surface is coated with a metal oxide in a carrier coat resin. It is described that it is prevented from being contaminated by a substance used for obtaining stable chargeability.
Patent Document 2 describes that the carrier spent is suppressed by attaching a charge control agent having the same polarity as the charge control agent used for the toner to the surface of the binder type carrier, thereby reducing the change in the charge amount of the toner. Has been.

In Patent Document 3, in a developer for developing an electrostatic image containing a toner and a carrier externally added with inorganic oxide fine particles, the developer has a volume average particle size in the range of 0.5 to 8.0 μm. Incorporating non-adhesive resin particles to the toner, this resin acts as a buffer to the inorganic oxide external additive between the toner and the film to prevent the inorganic oxide fine particles from adhering to the photoreceptor. Although prevention is described, this does not stabilize the chargeability of the toner.

Patent Documents 4 and 5 describe at least a hydrophobic aluminum oxide-silicon dioxide composite as an external additive in a negatively chargeable toner in which a hydrophobic external additive is at least externally added to toner base particles. It is described that charging characteristics are stabilized by using oxide particles and hydrophobic metal oxide fine particles having a work function larger than that of the aluminum oxide-silicon dioxide composite oxide particles. This document describes that good negative charging characteristics, generation of reverse transfer toner and suppression of fogging, transfer efficiency and charging can provide stable image quality over a longer period of time. However, only the same effect can be obtained as compared with the proposal of the toner to which silica and alumina are added separately, and if the ratio of alumina is large, the fog and charging properties, particularly durability in the environment resistance are difficult. The small particle size is also disadvantageous for obtaining the above effect, and the effect on the member, carrier contamination, and change in the state of the external additive on the toner surface is small.

Patent Document 6 discloses that a toner for a two-component magnetic developer in a magnetic brush developing method defines the dielectric constant and dielectric loss tangent (tan δ) within a predetermined numerical range, thereby developing and transferring the charged charge of the toner. It is described that it is sometimes maintained within an appropriate range.
Patent Document 7 discloses a loss tangent tan δ of a toner represented by a dielectric loss ratio ε ″ / dielectric constant ε ′ at a predetermined frequency in toner particles containing at least carbon black and a release agent used together with a magnetic carrier. It is described that a black toner having excellent chargeability and transferability can be obtained by setting a predetermined value.
However, the charge amounts of the toner in the two-component developer method cannot be sufficiently uniformed by the methods described in Patent Documents 1-7.

Next, a one-component developer system will be described. The system that uses a single-component developer is relatively easy to develop as a development system by not using a carrier, but it is disadvantageous in terms of printing speed and long life, and user maintenance and replacement are not required. It specializes in the field of small printers that are easy and low speed.
In this method, toner (developer) is usually conveyed to the developing unit by at least one toner conveying member, and the electrostatic latent image formed on the latent image carrier is visualized by the conveyed toner. In this case, the layer thickness of the toner transported on the surface of the toner transport member must be made as thin as possible. In particular, when a one-component developer is used and a toner having a high electrical resistance is used, the toner needs to be charged by a developing device, so that the toner layer thickness must be significantly reduced. This is because if the toner layer is thick, only the surface of the toner layer is charged, and the entire toner layer is difficult to be uniformly charged.

  In response to such demands, various methods have been proposed for the means for regulating the toner layer thickness on the toner conveying member (developer layer thickness regulating member). As a typical example, a regulating blade is used, and this blade is used for toner conveyance. There is a type in which the toner layer thickness is controlled by pressing the toner conveyed to the surface of the toner conveying member by a pressing member (regulating blade). There is also a type that obtains the same effect by contacting a roller instead of a blade.

  In addition, there are two methods for charging the surface of the photoconductor: a method using non-contact wire discharge and a method using contact injection, micro discharge, etc., but in recent years oxides generated during downsizing and discharge A contact charging method is preferably used for suppression.

In the developing process, in the toner layer formed on the surface of the developing sleeve by the developer layer thickness regulating member, the toner existing in the vicinity of the developing sleeve surface in the toner layer has a very high charge. Since the toner is strongly attracted to the surface of the sleeve by the reflection force and becomes immobile on the surface of the developing sleeve, the toner does not move from the developing sleeve to the latent image on the latent image carrier, and a charge-up phenomenon is likely to occur. Become. In particular, the charge-up phenomenon is likely to occur under low humidity.
When such a charge-up phenomenon occurs, the toner on the upper layer of the toner layer formed on the developing sleeve is less likely to be charged, so the charge amount of the toner is reduced. It tends to cause toner leakage and toner scattering.
In order to eliminate such a phenomenon, it is necessary to have a configuration in which the charge amount of the toner in the toner layer formed on the developing sleeve can be controlled as uniformly as possible.

In order to solve such problems, various treatment agents are used as will be described later, but problems arise.
Magnesium silicate minerals (Attapulgite, Sepiolite, etc.) described in Patent Document 8 have a high water content and are liable to cause poor charging even in normal use environments, resulting from poor charging such as dirt, toner leakage, and toner scattering. Problems are likely to occur. Further, since the Mohs hardness is low, filming on the photoconductor is likely to occur, and image defects such as image flow occur.
When the magnesium silicate treated with the silicone oil described in Patent Document 9 and Patent Document 10 is used, the toner fluidity deteriorates due to the silicone oil, the charge rises, and the like, causing the conveyance failure and the density decrease in the developing device.

  Patent Document 11 discloses a stable chargeability and sufficient resistance comprising a toner having a surface coated with 60% to 100% silicate fine powder treated with hexamethylsilazane and a carrier coated with a silicone resin on the surface. A fluid two-component developer is described. However, when a toner having a coverage of 60% to 100% is prepared using magnesium silicate as the fine silicate powder, a reversely charged toner is likely to be generated when used as a negatively charged toner, and background staining is likely to occur. Magnesium silicate tends to be positively charged due to the influence of the MgO part, which tends to be strongly positively charged, as shown in the relationship of electronegativity (Non-Patent Document 1: Journal of the Imaging Society of Japan, Vol. 39, No. 3, P.259). is there.

When the titanic acid fine powder is used as in the toner described in Patent Document 12, since the material itself has a low resistance, charging leakage is large, and background contamination, toner leakage, and toner scattering are likely to occur.
Further, the titanic acid fine powder is easily detached from the toner, and when the contact charging method is adopted, the contact charging member is contaminated, causing the electrostatic latent image holding member to be poorly charged and causing image defects.

Even when titania is used as in the toner described in Patent Document 13, since this material is a low-resistance and high-dielectric constant material, it is difficult to adjust the addition amount. In addition, when the amount is small, the charge is increased. As a result, in both cases, scumming, toner leakage, and toner scattering are likely to occur.
At the same time, when titania with a relatively large particle size is used, it easily detaches from the toner, and when the contact charging method is used, the contact charging member is contaminated, causing the electrostatic latent image carrier to be poorly charged and causing image defects. cause.
According to the methods described in the above documents 8 to 13, the charge amount of the toner in the one-component development method cannot be made sufficiently uniform.

JP 2000-98667 A Japanese Patent No. 3136756 JP 2002-156782 A Japanese Patent Laid-Open No. 2003-255592 JP 2003-255593 A Japanese Patent No. 2769317 JP 2004-78206 A JP 2002-31913 A JP-A-3-294864 JP-A-4-214568 JP 11-95480 A Japanese Patent Laid-Open No. 11-184239 JP 2003-186240 A Journal of the Imaging Society of Japan Vol.39 No.3 259

The present invention has been made for the purpose of solving the above problems in the prior art.
That is, an object of the present invention is to provide a one-component developer and a two-component developer in an electrostatic charge developing toner composition for use in a copying machine, a printer or the like applying an electrophotographic technique, and an image forming method using the same. An object of the present invention is to provide a toner that can be used as a toner and that can make the charge amount uniform.
Further, the present invention is particularly effective in performing frictional charging between the developing roller and the developer layer thickness regulating member in the developing device efficiently and uniformly, so that no scumming occurs and toner on the developing roller is excessive. It is an object of the present invention to provide a toner for developing an electrostatic charge that suppresses toner leakage of a supply toner due to a reset failure due to charging and streaks on a conveying surface due to electrostatic aggregation and that provides excellent image stability.

Another object of the present invention is to prevent the occurrence of filming on the photoconductor by using an external additive having an appropriate hardness, and to prevent the photoconductor from being damaged. It is an object of the present invention to provide an electrostatic charge developing toner composition that does not cause image defects such as image flow and does not impair the life of the photoreceptor.
Another object of the present invention is to efficiently and uniformly perform frictional charging between the developing roller and the developer layer thickness regulating member in the developing device in a configuration in which the thin layer forming material in the developing device is a combination of metal and resin. By doing so, no smudges occur, toner leakage from the toner supply due to reset failure due to overcharging of the toner on the developing roller, and streaks on the conveying surface due to electrostatic aggregation are suppressed, and excellent image stability is achieved. To provide a non-magnetic one-component image forming method. Still another object of the present invention is to impair the charging ability without causing a decrease in the resistance of the charging member even when the contact member is contaminated in the structure in which the electrostatic latent image holding member is charged by the contact method. It is an object of the present invention to provide an image forming method without any problems.

As a result of intensive studies by the present inventors, a toner externally added with composite oxide inorganic fine particles having a relative dielectric constant of 2 to 10 measured at 1 MHz and a volume resistivity of 10 ¹¹ Ω · cm or more is obtained. The present invention has been completed by finding that a stable chargeability and a sharp charge amount distribution can be obtained both when the toner is used as a one-component developer and when it is used as a two-component developer together with a carrier.

The above problems are solved by the following present inventions (1) to (22).
(1) In a toner in which inorganic fine particles are externally added to a toner base having at least a binder resin and a colorant, at least one of the inorganic fine particles has a relative dielectric constant of 2 to 10 measured at 1 MHz, and a volume resistivity. Wherein the toner is inorganic fine particles of a composite oxide having a particle size of 10 ¹¹ Ω · cm or more.
(2) The toner as described in (1) above, wherein the inorganic fine particles have a Mohs hardness of 4.5 to 8.
(3) The toner according to (1) or (2), wherein the inorganic fine particles are a complex oxide represented by the following general formula (1).
[M1] _a Si _b O _c (1)
(In the above formula, M1 represents a metal element selected from Sr, Mg, Zn, Co, Mn and Ce, a and b represent integers of 1 to 9, and c represents an integer of 3 to 9.)
(4) The toner according to (3), wherein the composite oxide is a magnesium silicate compound.
(5) The toner according to (3), wherein the composite oxide is a magnesium silicate compound represented by the following general formula (2). Mg _a Si _b O _c (2)
(In the above formula, a and b are integers of 1 to 9, and c is c = a + 2b)
(6) The toner according to (5), wherein the magnesium silicate compound is at least one selected from the group consisting of forsterite, steatite, and enstatite.
(7) The above inorganic particles (1) to (6), wherein the inorganic fine particles have a primary particle diameter of 0.05 to 1 μm and are added in an amount of 0.1 to 1.5 parts by mass with respect to 100 parts by mass of the toner base. The toner according to any one of the above.
(8) In the above (1) to (6), the inorganic fine particles have a primary particle diameter of 0.05 to 1 μm and are added in an amount of 0.1 to 5 parts by mass with respect to 100 parts by mass of the toner base. The toner according to any one of the above. (9) The toner according to any one of (1) to (8) above, wherein the toner is a full-color toner selected from at least magenta, cyan, yellow, and black.
(10) Any of (1) to (9) above, wherein the toner contains at least one type of release agent, and the release agent is contained in the toner base in an amount of 1 to 10% by mass. The toner described in 1.
(11) A one-component developer comprising the toner according to any one of (1) to (10).
(12) A two-component developer comprising the toner according to any one of (1) to (10) and a carrier. (13) In an image forming method in which a color image is formed by a developer containing a toner in which inorganic fine particles are externally added to a toner base having at least a binder resin, a colorant, and a charge control agent, the image forming method includes at least a static An electrostatic latent image forming step for forming an electrostatic latent image on a primary charged electrostatic latent image holding body having an electrostatic latent image holding body for holding the electrostatic latent image, Developing with a developer containing toner of each color possessed by a plurality of developing devices to form a toner image on the electrostatic latent image carrier, and toner of each color formed on the latent image carrier As a developer, the image forming apparatus includes a transfer step of transferring an image to a recording material with or without an intermediate transfer member, and a fixing step of fixing a toner image transferred to the recording material to the recording material. The developer according to (11) or (12) above Image forming method characterized in that there.
(14) The developing device used in the developing step includes a developing roller and a developer layer thickness regulating member that regulates a layer thickness of the developer formed on the surface of the developing roller. The image forming method described in 1.
(15) The image forming method according to (14), wherein at least the surface layer of the developing roller is made of metal, and at least the surface layer of the developer layer thickness regulating member is made of an elastic body.
(16) The nonmagnetic one-component image forming method as described in (14) above, wherein at least the surface layer of the developing roller is made of an elastic material, and at least the surface layer of the developer layer thickness regulating member is made of metal.
(17) The image forming method as described in any one of (13) to (16) above, wherein the primary charging of the latent image holding member is contact charging. (18) The image forming method as described in any one of (13) to (16) above, wherein at least the developing means applies an alternating electric field when developing the latent image on the image carrier.
(19) The above (13) to (1), wherein the fixing means for the toner image to the recording material is a heat roll type fixing device and does not have an oil application mechanism for imparting releasability. The image forming method according to any one of the above.
(20) The image forming method as described in any one of (13) to (19) above, wherein the developer is a one-component developer.
(21) The image forming method as described in any one of (13) to (19) above, wherein the developer is a two-component developer.
(22) In the process cartridge which integrally supports the electrostatic latent image holding member and at least one means selected from a charging means, a developing means, and a cleaning means, and is detachable from the image forming apparatus main body, A process cartridge, wherein the developing means holds the developer described in (11) or (12).

According to the present invention, between the developing roller and the developer layer thickness regulating member in the developing unit, particularly when the thin layer forming material in the developing unit is a combination of a metal and a resin, the developer is charged efficiently and uniformly. In this way, no smudges occur, toner leakage from the toner supplied due to reset failure due to overcharging of the toner on the developing roller, and streaks on the conveying surface due to electrostatic aggregation are suppressed, and excellent image stability is achieved. A toner composition for developing an electrostatic charge that can be obtained is provided, and an image forming method that does not impair the charging ability without causing a decrease in the resistance of the charging member even when the contact member is contaminated is provided. An extremely excellent effect is exhibited.
Furthermore, by adjusting the hardness of the external additive, a toner composition for developing an electrostatic charge that prevents filming on the photoreceptor and abrasion of the photoreceptor and does not cause image defects is provided. In particular, in a one-component developer, it is important to uniformly charge the developer layer formed on the developing roller because it is thin. However, the toner of the present invention can be more uniformly charged.
In addition, when the toner of the present invention is used as a two-component developer, the inorganic fine particles have an effect of suppressing electrostatic adhesion between the toner and the member, and are excellent in stainability and anti-spent to the carrier. Therefore, the carrier selection range is wide, and the change in charging performance accompanying durability can be suppressed.
The toner can be applied regardless of pulverization or polymerization, and the handling property is expected to be improved even for a small particle size toner.

The toner particles constituting the image forming toner of the present invention have at least a colorant and a resin, are treated with inorganic fine particles, and at least one kind has a relative dielectric constant measured at 1 MHz of 2 to 10, and has a volume specific The toner is treated with inorganic fine particles of a composite oxide having a resistance of 10 ¹¹ Ω · cm or more.
The composite oxide has a dielectric constant measured at 1 MHz of 2 to 10, more preferably 3 to 9, and a volume resistivity of 10 ¹¹ Ω · cm or more, preferably 10 for the purpose of assisting the charging property of the toner particles. Those having ¹² Ω · cm or more are preferable.
If the dielectric constant is less than 2, it does not function as a charging aid, and if it is more than 10, it causes a charge-up, and the toner is not uniformly charged in the developing device. On the other hand, if the volume specific resistance is smaller than 10 ¹¹ Ω · cm, the surface resistance is lowered when the electrostatic latent image holding member is attached to the charging member for charging the electrostatic latent image holding member, and charging of the electrostatic latent image holding member is caused.

As the composite oxide, a compound represented by the following general formula (1) is preferably used.
[M1] aSibOc
(In the above formula, M1 represents a metal element selected from Sr, Mg, Zn, Co, Mn and Ce, a and b represent an integer of 1 to 9, and c represents an integer of 3 to 9)
In particular, at least one selected from the group consisting of forsterite (Mg ₂ SiO ₄ ), steatite (MgSiO ₃ ), and enstatite is preferable because the effects of the present invention can be further exhibited.

The primary particle diameter of the composite oxide is suitably 0.05 to 1 μm, preferably 0.08 to 1 μm. If it is smaller than 0.05 μm, it is buried by stress at the thin layer forming portion of the developing device, and the effect at the end of durability cannot be exhibited. On the other hand, if it is larger than 1 μm, it is detached from the toner surface, and the effect at the end of the durability cannot be exhibited.
In the one-component developer, the addition amount of the composite oxide is suitably 0.1 to 1.5 parts by weight, preferably 0.2 to 1.5 parts by weight, based on 100 parts by weight of the toner base. . If the amount is less than 0.1 parts by mass, the effect of assisting charging cannot be exhibited, causing charge-up, and toner charging in the developing device becomes non-uniform. When the amount is more than 1.5 parts by mass, reversely charged toner is likely to be generated when used as a negatively charged toner, and background staining is likely to occur.
In the two-component developer, the addition amount of the composite oxide is 0.1 to 5 parts by mass, preferably 0.3 to 3 parts by mass, and more preferably 0.3 to 2 parts by mass with respect to 100 parts by mass of the toner base. 0 weight is preferably used. If the amount is less than 0.1 parts by mass, the effect of assisting charging cannot be exhibited, causing charge-up, and toner charging in the developing device becomes non-uniform. When the amount is more than 5 parts by mass, a negatively charged toner is likely to be generated when used as a negatively charged toner, and contamination due to grounding or detachment is likely to occur.
This is because magnesium silicate tends to be positively charged due to the influence of the MgO portion, which tends to be strongly positively charged, as shown by the relationship of electronegativity (see Non-Patent Document 1).

  Further, by setting the Mohs hardness of the external additive to 4.5 to 8, damage to the photoreceptor is prevented. When the Mohs hardness is less than 4.5, filming on the photosensitive member occurs, the proper charge is not charged, and image flow or the like occurs. On the other hand, if it is larger than 8, the photoconductor is scraped, scratches are caused on the photoconductor, resulting in image defects, and the life is remarkably reduced.

Forsterite and steatite have a very weak adhesion to metal for unknown reasons. Unlike the conductivity-imparting materials, these metals have a low dielectric constant and have a low saturation charge amount and a high volume resistance. It is considered that toner adhesion is suppressed as a result of suppressing excessive and excessive charging with the member.
For this reason, when the thin layer forming member in the developing device is a metal, the adhesion of the toner to the metal is suppressed. When a metal roller is used, the prevention of filming and the improvement of the toner reset property are promoted, and a metal blade is used. In the case, there is an effect of preventing filming.

  The toner base that can be used in the present invention usually contains a binder resin, a colorant, and other additives. In this toner base, (1) a colorant, a charge control agent, a release agent and the like are melt-mixed and uniformly dispersed in a thermoplastic resin as a binder resin component to obtain a composition. A toner base obtained by pulverizing and classifying the product, and (2) a polymerization initiator in which a colorant, a charge control agent, a release agent and the like are dissolved or suspended in a polymerizable monomer which is a binder resin raw material. A toner base obtained by dispersing in an aqueous dispersion medium containing a dispersion stabilizer, heating to a predetermined temperature to start suspension polymerization, and filtering, washing, dehydrating and drying after completion of the polymerization, ( 3) Primary particles of a binder resin containing a polar group obtained by emulsion polymerization are aggregated by adding a colorant and a charge control agent to give secondary particles, and at a temperature higher than the glass transition temperature of the binder resin. By stirring and associating the particles, the particles are filtered and dried. Toner base obtained, (4) Using a hydrophilic group-containing resin as a binder resin, adding a colorant or the like to dissolve in an organic solvent, neutralizing the resin, phase inversion, and then drying. Examples thereof include a phase inversion emulsification method toner base material for obtaining colored particles, and any of them can be used.

Although the present invention will be described using a pulverized toner, the present invention is not limited to this.
<Binder resin>
The type of binder resin is not particularly limited, and binder resins known in the field of full-color toners such as polyester resins, (meth) acrylic resins, styrene- (meth) acrylic copolymer resins, epoxy resins, COC (Cyclic olefin resin (for example, TOPAS-COC (manufactured by Ticona))) or the like, but from the viewpoint of stress resistance in the developing device, it is preferable to use a polyester resin.
As the polyester resin preferably used in the present invention, a polyester resin obtained by polycondensation of a polyhydric alcohol component and a polyvalent carboxylic acid component can be used. Among the polyhydric alcohol components, examples of the dihydric alcohol component include polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3,3) -2,2- Bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane Bisphenol A alkylene oxide adducts such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanedio , 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polytetramethylene glycol, bisphenol A, hydrogenated bisphenol A, and the like.
Examples of the trivalent or higher alcohol component include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol. 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, etc. Is mentioned.

  Among the polyvalent carboxylic acid components, examples of the divalent carboxylic acid component include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, and succinic acid. , Adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, n-octenyl succinic acid, isooctenyl succinic acid, n-octyl succinic acid , Isooctyl succinic acid, anhydrides or lower alkyl esters of these acids.

  Examples of the trivalent or higher carboxylic acid component include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2 , 4-Naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4- Examples include cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empole trimer acid, anhydrides of these acids, and lower alkyl esters.

  In the present invention, as a polyester resin, a polyester resin raw material monomer, a vinyl resin raw material monomer, and a mixture of monomers that react with both resin raw material monomers are used to obtain a polyester resin in the same container. A resin obtained by performing a condensation polymerization reaction and a radical polymerization reaction for obtaining a vinyl resin in parallel (hereinafter, simply referred to as “vinyl polyester resin”) can also be suitably used. In addition, the monomer which reacts with the raw material monomers of both resins is, in other words, a monomer that can be used for both the condensation polymerization reaction and the radical polymerization reaction. That is, it is a monomer having a carboxy group that can undergo a condensation polymerization reaction and a vinyl group that can undergo a radical polymerization reaction, and examples thereof include fumaric acid, maleic acid, acrylic acid, and methacrylic acid.

Examples of the raw material monomer for the polyester resin include the aforementioned polyhydric alcohol component and polyvalent carboxylic acid component.
Examples of the raw material monomer for the vinyl resin include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, p-ethyl styrene, 2,4-dimethyl styrene, p-tert. -Styrene or styrene derivatives such as butylstyrene and p-chlorostyrene; Ethylene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; Methyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n- methacrylate Butyl, isobutyl methacrylate, t-butyl methacrylate, n-pentyl methacrylate, isopentyl methacrylate, neopentyl methacrylate, 3- (methyl) butyl methacrylate, hexyl methacrylate, octyl methacrylate, noni methacrylate Alkyl methacrylates such as decyl methacrylate, undecyl methacrylate, dodecyl methacrylate; methyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, Acrylic acid such as n-pentyl acrylate, isopentyl acrylate, neopentyl acrylate, 3- (methyl) butyl acrylate, hexyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, undecyl acrylate, dodecyl acrylate Alkyl esters; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid; acrylonitrile, maleic acid ester, itaconic acid ester, vinyl chloride, vinyl acetate, vinyl benzoate, vinylmethyl Examples thereof include ruethyl ketone, vinyl hexyl ketone, vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether.

  As a polymerization initiator when polymerizing the raw material monomer of the vinyl resin, for example, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1 Azo or diazo polymerization initiators such as' -azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, benzoyl peroxide, dicumyl peroxide, And peroxide polymerization initiators such as methyl ethyl ketone peroxide, isopropyl peroxycarbonate, lauroyl peroxide, and the like.

  As the binder resin, various polyester resins as described above are preferably used. Of these, from the viewpoint of further improving the separability and offset resistance as an oilless fixing toner, It is more effective and preferable to use two binder resins together.

  That is, as the first binder resin, a polyester resin obtained by polycondensation of the above-described polyhydric alcohol component and polyvalent carboxylic acid component, in particular, a bisphenol A alkylene oxide adduct is used as the polyhydric alcohol component. A polyester resin obtained using terephthalic acid and fumaric acid as the acid component is used.

  The second binder resin is a vinyl polyester resin, in particular, bisphenol A alkylene oxide adduct, terephthalic acid, trimellitic acid and succinic acid are used as raw material monomers for the polyester resin, and styrene and butyl acrylate are used as the raw material monomers for the vinyl resin. And a vinyl polyester resin obtained using fumaric acid as a bireactive monomer.

  In the present invention, it is preferable that a hydrocarbon wax is internally added during the synthesis of the first binder resin. In order to add the hydrocarbon wax to the first binder resin in advance, when the first binder resin is synthesized, the hydrocarbon wax is added to the monomer for synthesizing the first binder resin. What is necessary is just to synthesize | combine binder resin. For example, the polycondensation reaction may be performed in a state where a hydrocarbon wax is added to an acid monomer and an alcohol monomer constituting the polyester resin as the first binder resin. When the first binder resin is a vinyl-based polyester resin, the vinyl-based resin raw material monomer is added dropwise to the polyester resin raw-material monomer while stirring and heating the monomer while the hydrocarbon-based wax is added. Thus, a polycondensation reaction and a radical polymerization reaction may be performed.

<Release agent (wax)>
Generally, the lower the polarity of the release agent (wax), the better the releasability from the fixing member roller.
The wax used in the present invention is a hydrocarbon wax having a low polarity and is advantageous for oilless fixing and low-temperature fixing. There is no limitation to these, and toners that do not contain wax may be used. Also, high-viscosity wax is used to improve high-temperature offset, and compatibility with low-molecular weight wax and resin is used to improve peel strength. In view of the above, it may be used as necessary, such as those adjusted for oxidation.

(Hydrocarbon wax)
The hydrocarbon wax is a wax composed of only carbon atoms and hydrogen atoms, and does not contain an ester group, an alcohol group, an amide group, or the like. Specific hydrocarbon waxes used when adding wax internally to the resin include polyolefin waxes such as polyethylene, polypropylene, copolymers of ethylene and propylene, petroleum waxes such as paraffin wax and microcrystalline wax, and Fischer-Tropsch waxes. And synthetic waxes. Among these, polyethylene wax, paraffin wax, and Fischer-Tropsch wax are preferable in the present invention, and polyethylene wax and paraffin wax are more preferable.

In addition, when the resin is not internally added with wax, for example, for use in a monochrome high-speed machine, it is preferable to contain polypropylene wax from the viewpoint of improving offset resistance, and smear resistance (at the time of automatic document feeding or From the viewpoint of improving the phenomenon that the image is rubbed by a roller when the paper having an image already formed on one side at the time of double-sided copying is rubbed by a roller and the image is deteriorated such as bleeding and smudges), polyethylene wax is included. Is preferred. Particularly preferred polypropylene waxes from the above viewpoint are polypropylene waxes having a melt viscosity at 160 ° C. of 50 to 300 cps, a softening point of 130 to 160 ° C. and an acid value of 1 to 20 KOH mg / g, and particularly preferred polyethylene waxes are 160 It is a polyethylene wax having a melt viscosity at 1000 ° C. of 1000 to 8000 cps and a softening point of 130 to 150 ° C. That is, the polypropylene wax having the melt viscosity, softening point, and acid value has excellent dispersibility in the binder resin, and can improve the offset resistance without causing a problem due to the free wax. The polyethylene wax having the above-mentioned melt viscosity and softening point is also excellent in dispersibility in the binder resin, and achieves improved smearing by reducing the coefficient of friction on the surface of the fixed image without causing problems due to free wax. Can do. The melt viscosity of the wax is a value measured with a Brookfield viscometer.

(Melting point of wax)
The melting point of the wax in the present invention is an endothermic peak of the wax at the time of temperature rise measured by a differential scanning calorimeter (DSC), and is preferably in the range of 70 ° C to 90 ° C. If it is higher than 90 ° C., the melting of the wax in the fixing process becomes insufficient, and the separation from the fixing member cannot be ensured. On the other hand, if the temperature is lower than 70 ° C., there is a problem in storage stability such that toner particles are fused in a high temperature and high humidity environment. In order to provide a sufficient margin for fixing separation at a low temperature, the melting point of the wax is more preferably from 70 ° C to 85 ° C, and further preferably from 70 ° C to 80 ° C.

(Endothermic peak of wax)
Moreover, it is preferable that the half value width of the wax endothermic peak at the time of temperature rise measured by a differential scanning calorimeter (DSC) is 7 ° C. or less. Since the melting point of the wax in the present invention is relatively low, a wax whose endothermic peak is broad, that is, melted from a low temperature range, adversely affects the storage stability of the toner.

(Wax content)
The content of the wax in the toner of the present invention is in the range of 1 to 10% by mass, preferably 1 to 8% by mass, more preferably 2 to 6.5% by mass. If the wax content is less than 1% by mass, the amount of wax that exudes between the molten toner and the fixing member in the fixing process is insufficient, and the adhesive force between the molten toner and the fixing member does not decrease. The recording member does not leave the fixing member. On the other hand, if the wax content exceeds 10% by mass, the amount of wax exposed on the toner surface increases, and the transfer efficiency from the developing unit to the photoconductor and from the photoconductor to the recording member increases due to the deterioration of the fluidity of the toner particles. This is not preferable because not only the image quality is significantly lowered, but also the wax on the surface of the toner is detached to cause contamination of the developing member and the photosensitive member.

(Content ratio of first binder resin and second binder resin)
The weight ratio of the first binder resin (including the weight of the internally added wax) and the second binder resin in the toner particles is 80/20 to 55/45, preferably 70/30 to 60/40. If the amount of the first binder resin is too small, the separability and the high temperature offset resistance are deteriorated. When there is too much 1st binder resin, glossiness and heat-resistant storage property will fall.
More preferably, the softening point of the binder resin composed of the first binder resin and the second binder resin used in the above weight ratio is 100 to 125 ° C., particularly preferably 105 to 125 ° C. In the present invention, the softening point of the binder resin composed of the first binder resin and the second binder resin into which wax is internally added may be in the above range.

The acid value of the wax-added first binder resin is preferably 5 to 50 KOHmg / g, and more preferably 10 to 40 KOHmg / g. The acid value of the second binder resin is preferably 0 to 10 KOHmg / g, and more preferably 1 to 5 KOHmg / g. In particular, when a polyester resin is used, by using a resin having such an acid value, the dispersibility of various colorants and the like can be improved, and a toner having a sufficient charge amount can be obtained.
The first binder resin preferably contains a component insoluble in tetrahydrofuran (THF) from the viewpoint of high temperature offset resistance. The THF-insoluble component content in the first binder resin added with wax is preferably 0.1 to 15% by weight, particularly 0.2 to 10% by weight, and more preferably 0.3 to 5% by weight.

<Colorant>
As the colorant used in the present invention, known pigments and dyes conventionally used as colorants for full-color toners can be used. For example, carbon black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, duPont oil red, quinoline yellow, methylene blue chloride, copper phthalocyanine, malachite green oxalate, lamp black, rose bengal, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 184, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 74, C.I. I. Solvent Yellow 162, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 185, C.I. I. Pigment blue 15: 1, C.I. I. And CI Pigment Blue 15: 3.
The content of the colorant in the toner particles is preferably in the range of 2 to 15 parts by weight with respect to 100 parts by weight of the total binder tree. It is preferable from the viewpoint of dispersibility that the colorant is used in the form of a masterbatch dispersed in a mixed binder resin of the first binder resin and the second binder resin used. The addition amount of the masterbatch may be an amount such that the amount of the colorant contained is within the above range. The colorant content in the masterbatch is preferably 20 to 40% by weight.

(Colorant masterbatch)
The colorant used in the present invention can also be used as a master batch combined with a resin. As the binder resin to be kneaded together with the production of the masterbatch or the masterbatch, in addition to the modified and unmodified polyester resins mentioned above, styrene such as polystyrene, poly p-chlorostyrene, polyvinyltoluene, and polymers of substituted products thereof; Styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer Styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α- Chloromethyl methacrylate copolymer, Tylene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-malein Styrene copolymers such as acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, poly Acrylic resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. The

(Master batch creation method)
This master batch can be obtained by mixing and kneading a resin for a master batch and a colorant under a high shear force to obtain a master batch. At this time, an organic solvent can be used to enhance the interaction between the colorant and the resin. Also, a so-called flushing method called watering paste containing water of a colorant is mixed and kneaded together with a resin and an organic solvent, and the colorant is transferred to the resin side to remove moisture and organic solvent components. Since it can be used as it is, it does not need to be dried and is preferably used. For mixing and kneading, a high shear dispersion device such as a three-roll mill is preferably used.

<Charge control agent>
In the toner of the present invention, a known charge control agent conventionally used in full color toners may be used.
For example, nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus Simple substance or compound, tungsten simple substance or compound, fluorine-based activator, salicylic acid metal salt, metal salt of salicylic acid derivative, and the like. Specifically, Bontron 03 of a nigrosine dye, Bontron P-51 of a quaternary ammonium salt, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex , Phenolic condensate E-89 (above, Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSY VP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit) Manufactured), copper phthalocyanine, perylene, quinacridone, azo series Fee, a sulfonic acid group, a carboxyl group, and polymer compounds having a functional group such as quaternary ammonium salts.
Of these, substances that control the negative polarity of the toner are particularly preferably used.
The amount of charge control agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the developer fluidity is lowered, and the image density is lowered. Invite.

<External additive>
In the present invention, other inorganic fine particles can be used as an external additive for assisting fluidity, developability and chargeability in combination with the above-described composite oxide.
Specific examples of the inorganic fine particles include, for example, silicon oxide, zinc oxide, tin oxide, silica sand, titanium oxide, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, Examples thereof include aluminum oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.
The total amount of the external additive in the present invention is preferably 1.0 to 5.0 parts by weight, more preferably 0.3 to 3.0 parts by weight, and still more preferably 0.3 to 3.0 parts by weight with respect to the toner base. 2.0 parts by weight. When the total amount of the external additive is larger than the above range, fogging, developability and fixing separation properties are deteriorated. When the total amount of external additives is less than the above range, fluidity, transferability, and heat-resistant storage properties are deteriorated.
The composite oxide fine particles of the present invention may be added in the toner during the production of the toner, and in this case, the amount is preferably 0.1 to 5.0 parts by weight based on the toner base. More preferably, it is 1-5.0 weight part, More preferably, it is 2-5 weight part. When the amount is small, the ratio of exposure to the toner surface becomes too low and the effect does not occur. If the amount is large, the translucency and color developability are impaired.

<Production method>
The toner of the present invention is a toner having a desired particle size by mixing, kneading, pulverizing, and classifying the first binder resin, the second binder resin, and the colorant in which the hydrocarbon wax is internally added by a conventional method. Particles (colored resin particles) can be obtained and mixed with an external additive.
The average particle size of the toner particles is 4 to 10 μm, preferably 5 to 10 μm.

(Developer configuration)
The developing device includes a developing roller and a developer layer thickness regulating member that regulates the layer pressure of toner formed on the surface of the developing roller.
The surface material of the developing roller is a metal material if the surface material of the developer layer thickness regulating member is an elastic body, and is an elastic body if the surface material of the developer layer thickness regulating member is a metal.

First, a case where the surface material of the developing roller is an elastic body will be described.
The developing roller is manufactured, for example, by covering the outer periphery of the conductive shaft with a rubber elastic body. The conductive shaft is made of a metal such as stainless steel, for example.

A surface coat layer made of a material that is easily charged to a polarity opposite to that of the toner is provided on the surface of the roller covered with a layer of elastic body (elastic rubber, resin, etc.). The elastic layer is set to a hardness of 60 degrees or less according to JIS-A in order to prevent toner deterioration due to pressure concentration at the contact portion with the developer layer thickness regulating member. The surface roughness Ra is set to 0.3 to 2.0 μm, and a necessary amount of toner is held on the surface. Further, since the developing roller is applied with a developing bias for forming an electric field between the developing roller and the electrostatic latent image holding member, the elastic layer is set to a resistance value of 10 ³ to 10 ¹⁰ Ω. The developing roller rotates in the clockwise direction, and conveys the toner held on the surface to a position facing the developer layer thickness regulating member and the electrostatic latent image holding member.

Next, the case where the developing roll is made of metal will be described.
The developing roller is blasted with glass beads to form a predetermined surface roughness. In particular, when the developing roll is made of an aluminum material, it is preferable because processing is easy. Moreover, the developing roll of this aluminum material can be easily formed to a predetermined surface roughness by adjusting the pressure for spraying the glass beads.
The developing roll surface roughness (Ra) is set in the range of 0.2 to 0.5 μm.

Below, the case where a developer layer control member is metal is demonstrated.
The developer layer thickness regulating member is provided at a position lower than the contact position between the supply roller and the developing roller. The developer layer thickness regulating member uses a metal leaf spring material such as SUS or phosphor bronze, and the free end is brought into contact with the surface of the developing roller with a pressing force of 10 to 40 N / m, and passes under the pressure. The developed developer is thinned and charged by triboelectric charging. Further, in order to assist frictional charging, the developer layer thickness regulating member is applied with a regulating bias having a value offset with respect to the developing bias in the same direction as the charging polarity of the toner.

Next, the case where the developer layer regulating member is an elastic body will be described.
The developer layer thickness regulating member is configured by attaching an elastic body to the surface of a metal leaf spring material such as SUS or phosphor bronze.
The rubber elastic body constituting the surface of the developing roller and the elastic body used for the regulating member is not particularly limited. For example, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber, acrylic rubber, epichlorohydrin Examples thereof include rubber, urethane rubber, silicon rubber, and blends of two or more thereof. Among these, a blend rubber of epichlorohydrin rubber and acrylonitrile-butadiene copolymer rubber is preferably used.

<Configuration of electrostatic latent image carrier charging member>
The charging member of the present invention includes a metal core (3), a conductive layer (5) on the metal core (3), and a surface layer (6) covering the conductive layer, and is formed in a cylindrical shape as a whole. It is a thing. A voltage applied to the core metal (3) by the power source (7) is applied to the core metal (3) via the conductive layer (5) and the surface layer (6) to the latent image carrier (1). The surface of the latent image carrier (1) is charged.

The cored bar (3) of the charging member (2) is disposed along the longitudinal direction of the latent image carrier (1) (parallel to the axis of the latent image carrier (1)), and the charging member (2) The whole is pressed against the latent image carrier (1) with a predetermined pressing force. As a result, a part of the surface of the latent image carrier (1) and a part of the surface of the charging member (2) are brought into contact with each other along the longitudinal direction to form a contact nip having a predetermined width. The latent image carrier (1) is rotationally driven by a driving means (not shown), and the charging member (2) is configured to be driven and rotated accordingly.
In the figure, exposure means, development means, transfer means, and cleaning means are omitted.

The latent image carrier (1) is charged by the power source (7) through the vicinity of the contact nip. Through the contact nip, the surface of the charging member (2) and the charged area (corresponding to the length of the charging member (2)) on the surface of the latent image carrier (1) are in contact with each other. The charged area on the surface of the carrier (1) is uniform.
The conductive layer (5) of the charging member (2) is a non-metal (conductive vulcanized rubber in this example), and a low-hardness material is used to stabilize the contact state with the latent image carrier (1). It can be preferably used. For example, resins such as polyurethane, polyether, and polyvinyl alcohol, and rubbers such as hydrin, EPDM, and NBR are used. Examples of the conductive material include carbon black, graphite, titanium oxide, and zinc oxide.

The surface layer (6) is made of a material having a resistance value of medium resistance (10 ² to 10 ¹⁰ Ω) (in this example, acetylene black-containing polyurethane-silicon acrylic polymer).
For example, nylon, polyamide, polyimide, polyurethane, polyester, silicon, Teflon (registered trademark), polyacetylene, polypyrrole, polytheophene, polycarbonate, polyvinyl, etc. can be used as the resin, but fluorine is used to increase the contact angle with water. It is preferable to use a series resin.
Examples of the fluorine-based resin include polyvinylidene fluoride, polyvinyl fluoride, vinylidene fluoride-tetrafluoroethylene copolymer, and vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene copolymer.
Furthermore, for the purpose of adjusting to a medium resistance, a conductive material such as carbon black, graphite, titanium oxide, zinc oxide, tin oxide, or iron oxide may be added as appropriate.

FIG. 2 shows an example of the image forming system of the present invention. In this image forming system, the photoconductor (11) rotates from the bottom to the top in the direction of the arrow. The developing roller (13) of the developing device (12) is driven as indicated by an arrow in contact with the photoreceptor (11) or holding a gap of about 0.1 to 0.3.
The material of the developing roller (13) is composed of a metal conductor such as aluminum or stainless steel having a suitable surface roughness by sandblasting. A toner supply roller (14) is provided around the developing roller (13), a rubber plate (urethane rubber, silicon rubber, etc.) is attached to the leaf spring material, or a metal material regulating blade (developer layer thickness regulating blade, such as SUS) ) (15) is arranged.
In order to supply toner to the toner supply roller (14), a toner feed shaft (16) is rotatably disposed in a holding chamber (17) that holds toner.

  Next, an example of an image forming apparatus using the electrophotographic toner of the present invention or a two-component developer composed of the toner and a carrier will be described. FIG. 3 is a schematic configuration diagram of the copying machine according to the present embodiment. Around a photosensitive drum (hereinafter referred to as a photosensitive member) (10) as an image carrier, a charging roller (20) as a charging means, an exposure means (30), a cleaning means (60) having a cleaning blade, a static elimination A neutralizing lamp (70) as a means, a developing means (40), and an intermediate transfer member (50) as an intermediate transfer member are provided. The intermediate transfer member (50) is suspended by a plurality of suspension rollers (51), and is configured to run endlessly in the direction of the arrow by a driving unit such as a motor (not shown). A part of the suspension roller (51) also serves as a transfer bias roller for supplying a transfer bias to the intermediate transfer member (50), and a predetermined transfer bias voltage is applied from a power source (not shown). A cleaning means (90) having a cleaning blade for the intermediate transfer member (50) is also provided. Further, a transfer roller (80) is disposed as a transfer means for transferring the developed image onto the transfer paper 100 as the final transfer material, facing the intermediate transfer body (50), and the transfer roller (80) is illustrated. The transfer bias is supplied by a power supply device that does not. Around the intermediate transfer member (50), a corona charger (52) is provided as a charge applying unit.

  The developing means (40) includes a developing belt (41) as a developer carrying member, a black (hereinafter referred to as Bk) developing unit (45K) and yellow (hereinafter referred to as Yk) provided around the developing belt (41). Development unit (45Y), magenta (hereinafter referred to as M) development unit (45M), and cyan (hereinafter referred to as C) development unit (45C). Further, the developing belt (41) is stretched between a plurality of belt rollers, and is configured to run endlessly in a direction of an arrow by a driving unit such as a motor (not shown), and a contact portion with the photoreceptor (10). Then, it moves at almost the same speed as the photoconductor (10).

  In addition to the apparatus configuration as shown in FIG. 3, the copying machine according to the present embodiment has a developing unit (45) for each color as shown in FIG. 4 around the photoconductor (10). A device configuration may be provided.

  Next, the operation of the copying machine according to the present embodiment will be described. In FIG. 3, the photosensitive member (10) is uniformly charged by the charging roller (20) while being driven to rotate in the direction of the arrow, and then the reflected light from the document is imaged and projected by an optical system (not shown) by the exposure means (30). Thus, an electrostatic latent image is formed on the photoconductor (10). The electrostatic latent image is developed by the developing means (40) to form a toner image as a visible image. The developer thin layer on the developing belt (41) is peeled off from the belt (41) in a thin layer state by contact with the photoreceptor in the developing region, and a latent image is formed on the photoreceptor (10). Transition to the part. The toner image developed by the developing means (40) is transferred to the intermediate transfer member (50) at a contact portion (primary transfer region) between the photosensitive member (10) and the intermediate transfer member (50) moving at a constant speed. (Primary transfer). When transferring three or four colors to be superimposed, this process is repeated for each color to form a color image on the intermediate transfer member (50).

  The corona charger (52) for applying an electric charge to the superimposed toner image on the intermediate transfer member, the photosensitive member (10) and the intermediate transfer member (in the rotation direction of the intermediate transfer member (50)). 50) on the downstream side of the contact facing portion and the upstream side of the contact facing portion between the intermediate transfer member (50) and the transfer paper (100). Then, the corona charger (52) gives the toner image a true charge having the same polarity as the charging polarity of the toner particles forming the toner image, so that the toner image can be satisfactorily transferred to the transfer paper (100). The toner image is sufficiently charged. The toner image is charged by the corona charger (52) and then transferred onto the transfer paper (100) conveyed in the direction of the arrow from a paper supply unit (not shown) by a transfer bias from the transfer roller (80). Batch transfer (secondary transfer). Thereafter, the transfer paper (100) onto which the toner image has been transferred is separated from the photoconductor (10) by a separation means (not shown), and after being fixed by a fixing means (not shown), the transfer paper (100) is discharged from the apparatus. On the other hand, after the transfer, the untransferred toner is collected and removed by the cleaning means (60), and the residual charge is discharged by the charge removal lamp (70) in preparation for the next charging.

  The surface layer material of the developing belt (41), the surface layer prevents contamination of the photosensitive member by an elastic material, reduces the surface friction resistance to the surface of the transfer belt and reduces the adhesion force of the toner, thereby improving the cleaning property and the secondary transfer property. What is needed is to be enhanced. For example, materials that use one or more of polyurethane, polyester, epoxy resin, etc. to reduce surface energy and increase lubricity, such as powders of fluororesins, fluorine compounds, fluorocarbons, titanium dioxide, silicon carbide, etc. One body, two or more kinds of particles or particles having different particle diameters can be dispersed and used. Further, it is also possible to use a material having a surface energy reduced by forming a fluorine-rich layer on the surface by heat treatment, such as a fluorine-based rubber material.

(Tandem type color image forming device)
The present invention can also be used as a tandem color image forming apparatus. An example of an embodiment of a tandem color image forming apparatus will be described with reference to FIG. In the figure, reference numeral (100) is a copying apparatus main body, (200) is a paper feed table on which the copying apparatus is placed, (300) is a scanner mounted on the copying apparatus main body (100), and (400) is an automatic document feeder mounted thereon. (ADF). The copying machine main body (100) is provided with an endless belt-shaped intermediate transfer member (10) in the center.
Then, as shown in FIG. 5, in the illustrated example, it is wound around three support rollers (14), (15) and (16) so as to be able to rotate and convey clockwise in the drawing.

  In this illustrated example, an intermediate transfer body cleaning means (17) for removing residual toner remaining on the intermediate transfer body (10) after image transfer is provided on the left of the second support roller (15) among the three. Further, among the three, the intermediate transfer member (10) stretched between the first support roller (14) and the second support roller (15) has yellow, cyan and magenta along the transport direction. The four black image forming means (18) are arranged side by side to constitute a tandem image forming apparatus (20).

  An exposure means (21) is further provided on the tandem image forming apparatus (20) as shown in FIG. On the other hand, a secondary transfer unit (22) is provided on the side opposite to the tandem image forming apparatus (20) with the intermediate transfer member (10) interposed therebetween. In the illustrated example, the secondary transfer means (22) is configured by a secondary transfer belt (24), which is an endless belt, spanned between two rollers (23) and (23), and an intermediate transfer body (10). And pressed against the third support roller (16) to transfer the image on the intermediate transfer member (10) onto the sheet.

Next to the secondary transfer means (22), a fixing means (25) for fixing the transfer image on the sheet is provided. The fixing means (25) is configured by pressing the pressure roller (27) against the fixing belt (26) which is an endless belt.
The secondary transfer means (22) described above is also provided with a sheet conveying function for conveying the sheet after image transfer to the fixing means (25). Of course, as the secondary transfer means (22), a transfer roller or a non-contact charger may be arranged. In such a case, it is difficult to provide this sheet conveying function together.

  In the illustrated example, a sheet is placed under such secondary transfer means (22) and fixing means (25) in order to record images on both sides of the sheet in parallel with the tandem image forming apparatus (20). A sheet reversing means (28) for reversing is provided.

When making a copy using this color electrophotographic apparatus, the document is set on the document table (30) of the automatic document feeder (400). Alternatively, the automatic document feeder (400) is opened, a document is set on the contact glass (32) of the scanner (300), and the automatic document feeder (400) is closed and pressed by it.
When a start switch (not shown) is pressed, when the document is set on the automatic document feeder (400), the document is transported and moved onto the contact glass (32), and then the other contact glass (32). When a document is set on the scanner, the scanner (300) is immediately driven to travel on the first traveling body (33) and the second traveling body (34). Then, the first traveling body (33) emits light from the light source, and the reflected light from the document surface is further reflected toward the second traveling body (34) and reflected by the mirror of the second traveling body (34). Then, the image is placed in the reading sensor (36) through the imaging lens (35) and the content of the original is read.

  When a start switch (not shown) is pressed, one of the support rollers (14), (15), and (16) is driven to rotate by the drive motor (not shown), and the other two support rollers are driven to rotate. The transfer body (10) is rotated and conveyed. At the same time, the individual image forming means (18) rotates the photoconductor (40) to form black, yellow, magenta, and cyan monochrome images on each photoconductor (40). Then, along with the conveyance of the intermediate transfer member (10), these monochrome images are sequentially transferred to form a composite color image on the intermediate transfer member (10).

On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers (42) of the paper feed table (200) is selectively rotated, and one of paper feed cassettes (44) provided in multiple stages in the paper bank (43). The sheet is fed out from the sheet, separated one by one by a separation roller (45), put into a sheet feeding path (46), and conveyed by a conveying roller (47) to a sheet feeding path (48) in the copying machine main body (100). Guide and stop against the registration roller (49).
Alternatively, the sheet feeding roller (50) is rotated to feed out the sheets on the manual feed tray (51), separated one by one by the separation roller (52), and placed in the manual sheet feeding path (53). ) And stop.
Then, the registration roller (49) is rotated in time with the composite color image on the intermediate transfer member (10), and the sheet is fed between the intermediate transfer member (10) and the secondary transfer means (22). A color image is recorded on the sheet after being transferred by the next transfer means (22).

  The sheet after the image transfer is conveyed by the secondary transfer means (22) and sent to the fixing means (25). The fixing means (25) applies heat and pressure to fix the transferred image, and then the switching claw. It is switched at (55), discharged by the discharge roller (56), and stacked on the discharge tray (57). Alternatively, it is switched by the switching claw (55) and put into the sheet reversing means (28), where it is reversed and led again to the transfer position, and an image is recorded also on the back surface, and then the paper discharge tray (56) is discharged by the discharge roller (56). 57) Drain up.

  On the other hand, the intermediate transfer body (10) after the image transfer is removed by the intermediate transfer body cleaning means (17) to remove residual toner remaining on the intermediate transfer body (10) after the image transfer, and the tandem image forming apparatus (20). To prepare for image formation again.

Here, the registration roller (49) is generally used while being grounded, but it is also possible to apply a bias for removing paper dust from the sheet.
In the tandem image forming apparatus (20) described above, the individual image forming means (18) is arranged in detail around the drum-shaped photoconductor (40) as shown in, for example, an enlarged view of the image forming unit in FIG. , A charging means (60), a developing means (61), a primary transfer means (62), a photosensitive member cleaning means (63), a charge eliminating means (64), and the like. 6 will be described. (65) is a developer on the developing sleeve, (68) is a stirring paddle, (69) is a partition plate, (71) is a toner concentration sensor, (72) is a developing sleeve, ( 73 is a doctor, 75 is a cleaning blade, 76 is a cleaning brush, 77 is a cleaning roller, 78 is a cleaning blade, 79 is a toner discharge auger, and 80 is a driving device.

(Process cartridge)
The process cartridge of the present invention develops an electrostatic latent image carrier carrying an electrostatic latent image and the electrostatic latent image carried on the electrostatic latent image carrier using a developer to form a visible image. And at least developing means for forming the image forming apparatus, and further having other means such as exposure means, transfer means, and cleaning means appropriately selected as necessary.

FIG. 7 shows a schematic configuration of an image forming apparatus having the process cartridge of the present invention.
In the figure, (101) indicates the entire process cartridge, (10) indicates a photosensitive member, (20) indicates a charging unit, (40) indicates a developing unit, and (60) indicates a cleaning unit.
In the present invention, the photosensitive member (10) and the developing means (40) described above are included, and further components such as the charging means (20), the developing means (40), and the cleaning means (60) are integrated as a process cartridge. The process cartridge is configured to be detachable from a main body of an image forming apparatus such as a copying machine or a printer.

  In the image forming apparatus having the process cartridge of the present invention, the photosensitive member is rotationally driven at a predetermined peripheral speed. In the rotation process, the photosensitive member is uniformly charged with a positive or negative predetermined potential on its peripheral surface by the charging unit, and then receives image exposure light from an image exposing unit such as slit exposure or laser beam scanning exposure. An electrostatic latent image is sequentially formed on the peripheral surface of the body, and the formed electrostatic latent image is then developed with toner by a developing unit, and the developed toner image is transferred between the photosensitive member and the transfer unit from the paper feeding unit. Then, the image is sequentially transferred to the transfer material fed in synchronization with the rotation of the photosensitive member by the transfer means. The transfer material that has received the image transfer is separated from the surface of the photosensitive member, introduced into the image fixing means, and fixed on the image, and printed out as a copy (copy). The surface of the photoconductor after the image transfer is cleaned by removing toner remaining after transfer by a cleaning unit, and after being further neutralized, it is repeatedly used for image formation.

Next, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.
First, a method for producing toner base particles will be described.
<Creation of first binder resin>
As a vinyl monomer, 600 g of styrene, 110 g of butyl acrylate, 30 g of acrylic acid, and 30 g of dicumyl peroxide as a polymerization initiator were placed in a dropping funnel. Among polyester monomers, as polyols, 1230 g of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.2) -2,2-bis (4 -Hydroxyphenyl) propane 290 g, isododecenyl succinic anhydride 250 g, terephthalic acid 310 g, 1,2,4-benzenetricarboxylic anhydride 180 g, dibutyltin oxide 7 g as esterification catalyst, wax as paraffin wax (melting point 73.3 ° C., 340 g (11.0 parts by weight with respect to 100 parts by weight of charged monomer) of 340 g of the endothermic peak at the time of temperature rise measured by a differential scanning calorimeter (4 ° C.), thermometer, stainless steel stirrer, flow-down condenser And a mantle heater in a 5 liter four-necked flask equipped with a nitrogen inlet tube Under a nitrogen atmosphere at medium while stirring at a temperature of 160 ° C., it was added dropwise over one hour a mixture of the vinyl monomer resins and the polymerization initiator from the dropping funnel. The addition polymerization reaction was aged for 2 hours while maintaining the temperature at 160 ° C., and then the temperature was raised to 230 ° C. to perform the condensation polymerization reaction. The degree of polymerization was tracked by the softening point measured using a constant load extrusion capillary rheometer, and when the desired softening point was reached, the reaction was terminated to obtain Resin H1. The resin softening point was 130 ° C.

<Creation of second binder resin>
As polyol, polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane 2210 g, terephthalic acid 850 g, 1,2,4-benzenetricarboxylic anhydride 120 g, and dibutyltin oxide as esterification catalyst 0.5 g was put into a 5-liter four-necked flask equipped with a thermometer, stainless steel stirrer, flow-down condenser and nitrogen inlet tube, and the temperature was raised to 230 ° C. in a nitrogen atmosphere in a mantle heater to perform the condensation polymerization reaction. Let The degree of polymerization was tracked by the softening point measured using a constant load extrusion capillary rheometer, and when the desired softening point was reached, the reaction was terminated to obtain Resin L1. The resin softening point was 115 ° C.

<Preparation of toner base particle A>
For 100 parts by mass (including the weight of the internally added wax) of the binder resin containing the first binder resin and the second binder resin in a ratio of 7: 3, C.I. I. After fully mixing a master batch equivalent to containing 4 parts by weight of Pigment Red 57-1 with a Henschel mixer, the one from which the discharge part of the biaxial extrusion kneader (PCM-30: manufactured by Ikekai Tekko Co., Ltd.) was removed was used. After melt-kneading, the obtained kneaded material was rolled to a thickness of 2 mm with a cooling press roller, cooled with a cooling belt, and then roughly pulverized with a feather mill. Then, after pulverizing with a mechanical pulverizer (KTM: Kawasaki Heavy Industries, Ltd.) to an average particle size of 10-12 μm and further pulverizing with a jet pulverizer (IDS: manufactured by Nippon Pneumatic Co., Ltd.) Then, fine powder classification was performed using a rotor type classifier (Teplex type classifier type: 100ATP: manufactured by Hosokawa Micron Corporation) to obtain colored toner base particles A. The particle diameter of the toner base particles A was 7.8 μm.

<Preparation of Toner Base Particle B> For 100 parts by mass (including the weight of the internal wax) of the binder resin containing the first binder resin and the second binder resin in a ratio of 7: 3, C.I. I. A master batch containing 4.5 parts by weight of Pigment Red 57-1 was sufficiently mixed with a Henschel mixer, and the two-screw extrusion kneader (PCM-30: manufactured by Ikekai Tekko Co., Ltd.) was used. The resulting kneaded product was rolled to a thickness of 2 mm with a cooling press roller, cooled with a cooling belt, and then roughly pulverized with a feather mill. Then, after pulverizing with a mechanical pulverizer (KTM: Kawasaki Heavy Industries, Ltd.) to an average particle size of 10-12 μm and further pulverizing with a jet pulverizer (IDS: manufactured by Nippon Pneumatic Co., Ltd.) Then, fine powder classification was performed using a rotor type classifier (Teplex type classifier type: 100ATP: manufactured by Hosokawa Micron Corporation) to obtain toner base particles B. The average particle diameter of the toner base particles B was 7.8 μm.

<Preparation of Toner Base Particle C> As a cyan pigment, 50 parts of C.I. I. Pigment Blue 15: 3, 10 parts of sodium dodecyl sulfate and 200 parts of ion-exchanged water were dispersed using a sand grinder mill to obtain a colorant dispersion having a volume average particle diameter of 170 nm.
A 5000 ml separable flask equipped with a stirrer, temperature sensor, cooling tube, and nitrogen introducing device was charged with a solution prepared by dissolving 4.05 parts of sodium dodecyl sulfate in 2500 parts of ion-exchanged water and stirred at 230 rpm under a nitrogen stream. The temperature was raised to 80 ° C. while stirring at a speed. Next, after adding a solution prepared by dissolving 9.62 parts of potassium persulfate in 200 parts of ion-exchanged water, 568 parts of styrene, 164 parts of n-butyl acrylate, 68 parts of methacrylic acid, and 16.51 of n-octyl mercaptan. Part of the mixture was added dropwise over 1.5 hours, and the mixture was heated and stirred at 80 ° C. for 2 hours to carry out polymerization (first stage polymerization) to prepare latex (1H). The weight average particle diameter of the latex (1H) was 68 nm.
In a flask equipped with a stirrer, 123.81 parts of styrene, 39.51 parts of n-butyl acrylate, 12.29 parts of methacrylic acid, 0.72 parts of n-octyl mercaptan, ester wax AC (CH ₂ —O— 475 parts of CO— (CH ₂ ) ₂ 0—CH ₃ ), 10 parts of bisphenol compound 1 were charged, heated to 80 ° C. and dissolved to prepare a monomer solution.

A solution prepared by dissolving 0.6 part of a surfactant represented by the following chemical formula (1) in 2700 parts of ion-exchanged water is heated to 98 ° C., and 32 parts of latex (1H) is added in terms of solid content, and then a monomer solution. Was added and mixed and dispersed for 8 hours using a mechanical disperser CLEARMIX (M Technique Co., Ltd.) having a circulation path to prepare a dispersion.
_{C 10 H 21 (OCH 2 CH} 2) 2 OSO 3 - Na +
Next, a solution obtained by dissolving 6.12 parts of potassium persulfate in 250 parts of ion-exchanged water is added to this dispersion, and the mixture is heated and stirred at 82 ° C. for 12 hours, whereby polymerization (second stage polymerization) is performed. To obtain latex (1HM).
After adding a solution prepared by dissolving 8.8 parts of potassium persulfate in 350 parts of ion exchange water to latex (1HM), at 82 ° C., 350 parts of styrene, 95 parts of n-butyl acrylate, 5 parts of methacrylic acid, and A 1 mol% n-octyl mercaptan mixture of monomers was added dropwise over 1 hour. After completion of the dropping, the mixture was heated and stirred at 82 ° C. for 2 hours to carry out polymerization (third stage polymerization) and cooled to 28 ° C. to obtain latex (1HML).
In a reaction vessel (four-necked flask) equipped with a temperature sensor, a cooling tube, a nitrogen introducing device, and a stirring device, 420 parts of latex (1HML) (solid content conversion), 900 parts of ion-exchanged water and 150 parts of a colorant dispersion are added. Charged and stirred. After adjusting the temperature in a container to 30 degreeC, 5N sodium hydroxide aqueous solution was added and pH was adjusted to 8-10.

Next, a solution prepared by dissolving 65 parts of magnesium chloride hexahydrate in 1000 parts of ion-exchanged water was added over 10 minutes with stirring. After standing for 3 minutes, the temperature was raised to 92 ° C. to produce aggregated particles. In this state, the particle diameter of the aggregated particles was measured using a Coulter Counter TA-II (manufactured by Beckman Coulter), and when the number average particle diameter reached 6.1 μm, 80.4 parts of sodium chloride was ionized. A solution dissolved in 1000 parts of exchange water was added to stop particle growth. Furthermore, as a ripening treatment, the particles were fused and the phase separation of the crystalline substance was continued by heating and stirring at 94 ° C. In this state, the shape of the fused particles was measured using FPIA-2000 (manufactured by Sysmex Corporation), and when the average circularity reached 0.960, the mixture was cooled to 30 ° C. and stirring was stopped. The produced fused particles were filtered, washed repeatedly with ion exchange water at 45 ° C., and dried with hot air at 40 ° C. to obtain toner base particles C. When the average particle size and shape factor of the toner base particles C were measured again, they were 7.1 μm and 0.958, respectively.

<Manufacture of carriers>
While flowing 5 kg of Cu-Zn ferrite having a particle diameter of 45 μm in a fluidized bed type coating apparatus, 500 g of silicone resin liquid (SR-2411, solid content 20% by weight, manufactured by Toray Dow Corning Silicone) and 1450 g of toluene are included. The solution was sprayed under heating at 80 ° C., and further baked at 210 ° C. for 2 hours to obtain a carrier coated with a silicone resin.

(Creation of magnesium silicate compound)
Mg (OH) ₂ powder slurry and SiO ₂ powder (average primary particle size 0.02 μm) were weighed to 2: 1 with MgO: SiO ₂ (molar ratio), MgO concentration 71.5 g / L, SiO 2 ₂ Using a sand grinder mill with 0.8 mmφ alumina silica beads, the media filling rate is 80%, the feeding speed is 4.0 L / min, and the number of slurry passes. Was wet pulverized under three-pass conditions. The slurry was spray-dried with a spray dryer and fired at 1100 ° C. for 30 minutes in the air in an electric furnace. Then, the fired product is slurried to 300 g / L, 50 L is sand grinder mill, 0.8 mmφ alumina silica-based beads are used as media, the media filling rate is 80%, and the liquid feeding speed is 5.6 L / The wet pulverization was performed under the conditions of min and the number of slurry passes of 2 passes. The slurry was spray-dried with a spray dryer and pulverized with a sand mill to obtain inorganic oxide 1 (forsterite) shown in Table 2.
Moreover, it produced similarly except having performed except the slurry pass number of times of the wet grinding | pulverization after baking, and obtained the inorganic oxide 2 (forsterite) shown in Table 2.
Next, it was weighed so as to be 1: 1 with MgO: SiO ₂ (molar ratio), and prepared similarly except that the slurry was 150 L with a MgO concentration of 35.8 g / L and a SiO ₂ concentration of 53.3 g / L. Inorganic oxide 3 (enstatite) shown in Table 2 was obtained.
Table 2 shows the physical properties of the obtained magnesium silicate compound.

[Example 1]
Toner base particle A 100 parts by mass of inorganic oxide (forsterite) 0.4 parts by mass (first inorganic fine particles) shown in Table 1, silica RX200 (manufactured by Nippon Aerosil Co., Ltd.) 1 part by mass (second inorganic fine particles) Was added and mixed with a Henschel mixer (peripheral speed 40 m / sec, 60 seconds) to obtain magenta toner 1.
Using the above magenta toner 1 as a one-component developer, IPSiO CX2500 manufactured by Ricoh Co., Ltd. was used, and a predetermined print pattern with a printing rate of 6% was continuously 2000 sheets in an N / N environment (23 ° C., 45%). After copying, the condition of the developing roller of the developing unit, the copy image, filming on the photoreceptor, and scratches on the photoreceptor were visually observed and evaluated.
The evaluation results are shown in Table 1.
Judgment criteria are as follows.
○: Good, △: Level with no problem in actual use, ×: NG in actual use

[Examples 2 to 9, Comparative Examples 1 to 3]
Hereinafter, magenta toners 2 to 12 of Examples 2 to 9 and Comparative Examples 1 to 3 were obtained in the same manner as Example 1 except that the external additives listed in Table 1 were used. Using these magenta toners, print patterns were evaluated in the same manner as in Example 1.
The forsterite used in this example has been conventionally known as a raw material for producing ceramics (see, for example, JP-A-2003-327470).

[Example 10]
<Creation of toner particles>
As shown in Table 3, 1.5 parts by mass of inorganic oxide 1 (forsterite) (first inorganic fine particles) and external additive 1 shown in Table 3 are added to 100 parts by mass of toner base particle B, and a Henschel mixer is added. (Peripheral speed 40 m / sec, 60 seconds) was mixed to obtain the toner of Example 10.
The above toner is mixed with the carrier and set as a two-component developer in a full-color copying machine (PRETER 550, manufactured by Ricoh Co., Ltd.) in a low temperature and low humidity environment (temperature 10 ° C., relative humidity 15%) and in a high temperature and high humidity environment. At a temperature of 30 ° C. and a relative humidity of 80%, a color image (5% print image) was continuously printed on 1,000 sheets, and then repeated for 200,000 sheets in a mode in which the image was paused for 30 minutes. The following various evaluations were performed. .
The evaluation results at this time are shown in Table 3.
Here, ○, Δ, and × in Table 3 are obtained by evaluating each evaluation item in three stages, ○ is a very good level, Δ is a level that has no practical problem, and × is a level that has a practical problem. Respectively.

The evaluation method was as follows.
(Image density and tracking)
The solid image density after continuous copying is measured by X-Rite 939, and the difference between the image density at the initial position and after printing end of the same part 5 cm upstream from the leading edge and 5 cm upstream from the trailing edge is measured in three stages. evaluated.
(Dirt)
The ΔE of the scumming toner was determined by a tape transfer method. The tape transfer method is a method in which Sumitomo 3M's mending tape is applied onto the toner on the photoconductor to transfer fog toner onto the tape. The reflection density was measured by X-Rite 939, and the value obtained by subtracting the reflection density of the tape from the measured value (C *) was taken as the fog reflection density (ΔE).

[Examples 11 to 19, Comparative Examples 4 to 6]
Thereafter, toners of Examples 11 to 19 and Comparative Examples 4 to 6 were obtained in the same manner as in Example 10 except that the toner base, inorganic fine particles and external additives shown in Table 3 were used. Using these magenta toners, print patterns were evaluated in the same manner as in Example 10, and the evaluation results are shown in Table 3.

<Measurement and evaluation method>
A method for measuring physical properties of the material used and a method for evaluating the obtained sample will be described.
(Toner particle size (Coulter))
A method for measuring the particle size distribution of the toner particles will be described. As an apparatus for measuring the particle size distribution of toner particles by the Coulter Counter method, there are Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter).
The measurement method is described below.
First, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution. Here, the electrolytic solution is prepared by preparing an about 1% NaCl aqueous solution using primary sodium chloride, and for example, ISOTON-II (manufactured by Coulter) can be used. Here, 2 to 20 mg of the measurement sample is further added as a solid content. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes. Volume distribution and number distribution are calculated. From the obtained distribution, the weight average particle diameter (Dv) and the number average particle diameter (Dp) of the toner can be obtained. As channels, 2.00 to less than 2.52 μm; 2.52 to less than 3.17 μm; 3.17 to less than 4.00 μm; 4.00 to less than 5.04 μm; 5.04 to less than 6.35 μm; 6 .35 to less than 8.00 μm; 8.00 to less than 10.08 μm; 10.08 to less than 12.70 μm; 12.70 to less than 16.00 μm; 16.00 to less than 20.20 μm; Uses 13 channels of less than 40 μm; 25.40 to less than 32.00 μm; 32.00 to less than 40.30 μm, and targets particles having a particle size of 2.00 μm to less than 40.30 μm.

(Average circularity)
As a method for measuring the shape, an optical detection band method is suitable in which a suspension containing particles is passed through an imaging unit detection band on a flat plate, and a particle image is optically detected and analyzed by a CCD camera. The average circularity is a value obtained by dividing the perimeter of an equivalent circle having the same projected area obtained by this method by the perimeter of the actual particle.
This value is a value measured as an average circularity by a flow type particle image analyzer FPIA-2000. As a specific measuring method, 0.1 to 0.5 ml of a surfactant, preferably alkylbenzene sulfonate is added as a dispersant to 100 to 150 ml of water from which impure solids have been removed in advance, and further measurement is performed. Add about 0.1-0.5g of sample. The suspension in which the sample is dispersed is obtained by performing dispersion treatment for about 1 to 3 minutes with an ultrasonic disperser and measuring the shape and distribution of the toner with the above apparatus at a dispersion concentration of 3000 to 10,000 / μl. .

(Softening point (Tm))
Using a flow tester (CFT-500 / manufactured by Shimadzu Corporation), 1.5 g of a measurement sample was weighed, and using a die of H1.0 mm × φ1.0 mm, the heating rate was 3.0 ° C./min, and the preheating time was 180. Measurement was performed under conditions of a second, a load of 30 kg, and a measurement temperature range of 80 to 140 ° C., and the temperature at which the above sample flowed out 1/2 was taken as the softening point.
(Inorganic fine particle size measurement (TEM))
Inorganic fine particles were embedded in a resin, thin pieces were prepared with a microtome, and the particle diameter was measured by TEM observation.

(Specific permittivity measurement)
1 g of the measurement object was placed in a liquid cell (12964A type 5 ml liquid measurement cell), and this was sandwiched between electrodes, and measured with an impedance analyzer 1260 type (manufactured by Solartron) at AC 1 MHz.
(Volume resistivity measurement)
3 g of toner was sandwiched between electrodes of a sample box TR42 for measuring ultrahigh resistance manufactured by Advantest, and measured at DC 500 V using a digital ultrahigh resistance / microammeter R8340A.
(Mohs hardness measurement)
The pellets of the above-mentioned external additives (prepared) are prepared, the surface is rubbed with the standard substance of Table 4 for determining the Mohs hardness, and the hardness is measured by the presence or absence of scratches. Table 4 shows the Mohs hardness table.
The one located in the middle displays 1/2.

(Actual machine evaluation)
In the case of one-component development Using IPCO CX2500, manufactured by Ricoh Co., Ltd., developing a developer with a predetermined print pattern with a printing rate of 6% after continuous copying of 2000 sheets in an N / N environment (23 ° C, 45%) The condition of the roller, the copy image, filming on the photoconductor, and photoconductor scratches were visually observed and evaluated.
Judgment criteria are as follows.
○: Good, △: Level with no problem in actual use, ×: NG in actual use

It is a figure which shows an example of the charging member used in the image forming method of this invention. It is a figure which shows an example of the image formation system of this invention. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus using an image forming system of the present invention. It is a schematic block diagram which shows the other example of the image forming apparatus using the image forming system of this invention. 1 is a schematic configuration diagram showing an example of a tandem type color image forming apparatus using an image forming system of the present invention. 1 is an enlarged view of an image forming unit of an example of a tandem type color image forming apparatus using an image forming system of the present invention. It is a figure which shows an example of the process cartridge of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Latent image carrier 2 Charging member 3 Metal core 5 Conductive layer 6 Surface layer 7 Power source 11 Photoconductor 12 Developing device 13 Developing roller 14 Toner supply roller 15 Developer layer thickness regulating member 16 Toner feed shaft 17 Holding chamber (FIG. 3) About Figure 4)
DESCRIPTION OF SYMBOLS 10 Photoconductor 20 Charging roller 30 Exposure means 40 Developing means 41 Developing belt 42 Developer container 43 Supply roller 44 Conveying roller 45 Developing unit 50 Intermediate transfer body 51 Suspension roller 52 Corona charger 60 Cleaning means 70 Static elimination lamp 80 Transfer roller 90 Cleaning Means 100 Transfer paper (FIGS. 5 and 6)
DESCRIPTION OF SYMBOLS 10 Intermediate transfer body 14 Support roller 15 Support roller 16 Support roller 17 Intermediate transfer body cleaning means 18 Image forming means 20 Tandem image forming apparatus 21 Exposure means 22 Secondary transfer means 23 Roller 24 Secondary transfer belt 25 Fixing means 26 Fixing belt 27 Pressure roller 28 Sheet reversing means 30 Document table 32 Contact glass 33 First traveling body 34 Second traveling body 35 Imaging lens 36 Reading sensor 40 Photoconductor 42 Paper feed roller 43 Paper bank 44 Paper feed cassette 45 Separating roller 46 Paper feed Path 47 transport roller 48 paper feed path 49 registration roller 50 paper feed roller 51 manual feed tray 52 separation roller 53 manual paper feed path 55 switching claw 56 discharge roller 57 paper discharge tray 60 charging means 61 developing means 62 primary transfer means 63 photoconductor Cleaning means 64 Static elimination means 65 Development Leave agent developer 68 Stir paddle 69 Partition plate 71 Toner density sensor 72 Developing sleeve 73 Doctor 75 Cleaning blade 76 Cleaning brush 77 Cleaning roller 78 Cleaning blade 79 Toner discharge auger 80 Drive device 100 Copier main body 200 Paper feed table 300 Scanner 400 Document Automatic transfer device (ADF)
(About Figure 7)
101 Overall process cartridge 10 Photoconductor,
20 charging means,
40 developing means,
60 Cleaning means

Claims (22)

At least one of the inorganic fine particles externally added to a toner base having a binder resin and a colorant, the relative dielectric constant measured at 1 MHz is 2 to 10, and the volume resistivity is 10 ^11. A toner comprising inorganic fine particles of a complex oxide having a resistance of Ω · cm or more.   The toner according to claim 1, wherein the inorganic particles have a Mohs hardness of 4.5 to 8. The toner according to claim 1, wherein the inorganic fine particles are a composite oxide represented by the following general formula (1). [M1] _a Si _b O _c (1)
(In the above formula, M1 represents a metal element selected from Sr, Mg, Zn, Co, Mn and Ce, a and b represent integers of 1 to 9, and c represents an integer of 3 to 9.)   The toner according to claim 3, wherein the composite oxide is a magnesium silicate compound. The toner according to claim 3, wherein the composite oxide is a magnesium silicate compound represented by the following general formula (2). Mg _a Si _b O _c (2)
(In the above formula, a and b are integers of 1 to 9, and c is c = a + 2b)   The toner according to claim 5, wherein the magnesium silicate compound is at least one selected from the group consisting of forsterite, steatite, and enstatite.   7. The inorganic fine particles having a primary particle diameter of 0.05 to 1 [mu] m and 0.1 to 1.5 parts by mass with respect to 100 parts by mass of a toner base are added. Toner.   The toner according to claim 1, wherein the inorganic fine particles have a primary particle diameter of 0.05 to 1 μm and are added in an amount of 0.1 to 5 parts by mass with respect to 100 parts by mass of the toner base. . The toner according to claim 1, wherein the toner is a full-color toner selected from at least magenta, cyan, yellow, and black. The toner according to claim 1, wherein the toner contains at least one release agent, and the release agent is contained in the toner base in an amount of 1 to 10% by mass.   A one-component developer comprising the toner according to claim 1.   A two-component developer comprising the toner according to claim 1 and a carrier. In an image forming method for forming a color image with a developer including a toner in which inorganic fine particles are externally added to a toner base having at least a binder resin, a colorant, and a charge control agent, the image forming method includes at least an electrostatic latent image. An electrostatic latent image forming step for forming an electrostatic latent image on the primary charged electrostatic latent image holding member, and developing the electrostatic latent image into a plurality of developments A developing step of developing with a developer containing toner of each color included in the apparatus to form a toner image on the electrostatic latent image carrier, and a toner image of each color formed on the latent image carrier intermediate 12. A transfer step of transferring to a recording material with or without a transfer member, and a fixing step of fixing a toner image transferred to the recording material to the recording material. Or using the developer described in 12 above. Image forming method according to.   The image according to claim 13, wherein the developing device used in the developing step includes a developing roller and a developer layer thickness regulating member that regulates a layer thickness of the developer formed on the surface of the developing roller. Forming method.   The image forming method according to claim 14, wherein at least a surface layer of the developing roller is made of metal, and at least a surface layer of the developer layer thickness regulating member is made of an elastic body.   15. The nonmagnetic one-component image forming method according to claim 14, wherein at least a surface layer of the developing roller is made of an elastic body, and at least a surface layer of the developer layer thickness regulating member is made of a metal. The image forming method according to claim 13, wherein primary charging of the latent image holding member is contact charging.   The image forming method according to claim 13, wherein an alternating electric field is applied at least when the developing means develops the latent image on the image bearing member.   The image according to any one of claims 13 to 18, wherein the fixing means for the toner image to the recording material is a heat roll type fixing device and does not have an oil application mechanism for imparting releasability. Forming method.   The image forming method according to claim 13, wherein the developer is a one-component developer.   The image forming method according to claim 13, wherein the developer is a two-component developer.   In a process cartridge that integrally supports an electrostatic latent image holding member and at least one unit selected from a charging unit, a developing unit, and a cleaning unit, and is detachable from the image forming apparatus main body, the developing unit includes: A process cartridge holding the developer according to claim 11 or 12.

Images