JP2003066656A - Two-component system developer and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-component system developer containing a carrier which has performance of not giving rise to a change in the amount of toner deposition to a transfer material in spite of progression of the wearing out of a coating layer of a carrier core material and not giving rise to a fluctuation in the resistance value of the carrier and to provide an image forming method by which good image density can be obtained through the entire part of the life and the electrophotographic images having good image quality free of the occurrence of fogging and character fringes can be obtained. SOLUTION: The two-component system developer which is a two-component developer having toners containing a binder resin and coloring agents and a carrier, in which the carrier consists of a carrier core material having the coating layer containing metal oxide particles and the density of the metal oxide particles in the coating layer is smallest at the boundary with the carrier core material and the image forming method using the two-component system developer described above.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-component developer used in an electrophotographic image forming apparatus such as a copying machine and a printer, and an image forming method using the two-component developer.

[0002]

2. Description of the Related Art An image forming technique using a two-component developer containing a toner and a carrier imparts a preferable charging performance to the toner through the carrier, so that an electronic image having a good image quality is obtained. This is preferable for obtaining a photographic image. However, since the carrier core material that constitutes the carrier is inherently fragile, the carrier core material tends to be broken by the impact of the particles constituting the developer during image formation, which improves the durability of the carrier. Although improved techniques have been studied so far, development of carriers having durability while maintaining appropriate charging performance of the core itself has been advanced.

A carrier having a coating layer formed on a carrier core material is effective for improving the durability of the core material as disclosed in JP-A No. 7-110603, but with repeated image formation. The carrier resistance increased and the image quality fluctuated. Therefore, it has been attempted to thin the resin coating layer or add metal oxide particles into the coating layer in order to maintain the initial image density, but it is difficult to secure the durability of the carrier by thinning the coating layer. Although the addition of metal oxide particles to the resin coating layer ensures durability, the amount of toner adhered to the transfer material becomes unstable with repeated image formation, and stable image formation is maintained. Had a difficult problem.

As described above, an image forming technique using a two-component developer using a highly durable carrier capable of maintaining stable charging performance and stable image formation even in repeated image formation was in the process of development.

[0005]

The present invention has been accomplished in view of the above technical problems. That is, the present invention is
It is an object of the present invention to provide a two-component developer using a highly durable carrier capable of forming an image having a stable image quality for a long period while maintaining excellent charging performance. It is an object of the present invention to provide an image forming method which can obtain an electrophotographic image having a beautiful image quality with stability by using a two-component type developer containing

Further, the present invention provides the above two-component developer obtained by polymerizing the toner in the developer in an aqueous medium, and an image forming method using the two-component developer. That is the purpose.

[0007]

[Means for Solving the Problems] In order to solve the above problems, the inventors of the present invention have diligently studied hard, and have determined the concentration of metal oxide particles contained in the resin coating layer of the carrier core material. Focusing attention, it has been found that providing a gradient in the metal oxide particle content concentration in the resin coating layer does not change the chargeability of the carrier even if the coating layer of the carrier core material is worn by repeated image formation. .

That is, the present invention does not make the concentration of the metal oxide in the resin coating layer of the carrier core material in the resin coating layer from the interface with the core material to the surface thereof uniform. At the interface of, the concentration of metal oxide is the smallest,
The metal oxide concentration in the coating layer was made to have a concentration gradient so that the concentration of the metal oxide increased toward the surface. The present invention is achieved by adopting any one of the following configurations.

[1] A two-component developer having a toner containing a binder resin and a colorant and a carrier,
The carrier is one in which the carrier core material has a coating layer containing metal oxide particles, and the concentration of the metal oxide particles in the coating layer is the smallest at the interface with the carrier core material. A characteristic two-component developer.

[2] A two-component developer having a toner containing a binder resin and a colorant and a carrier,
The toner is particles formed in an aqueous medium, the carrier is a carrier core material having a coating layer containing metal oxide particles, the concentration of the metal oxide particles in the coating layer is A two-component developer having the smallest interface with the carrier core material.

[3] The two-component developer according to the above [1] or [2], which has a toner containing a binder resin and a colorant, and a carrier, in the coating layer of the carrier core material. A two-component developer characterized in that the concentration of the metal oxide particles has a concentration gradient and is the highest on the surface of the coating layer.

[4] The two-component developer according to any one of the above [1] to [3], which has a toner containing a binder resin and a colorant, and a carrier, wherein the carrier core material The two-component developer is characterized in that the coating layer of is composed of a plurality of layers having different concentrations of metal oxide particles.

[5] The two-component developer according to any one of [1] to [4], which has a toner containing a binder resin and a colorant, and a carrier, wherein the metal oxide is A two-component developer in which particles have a spindle-like shape.

[6] The two-component developer according to any one of [1] to [5], which has a toner containing a binder resin and a colorant, and a carrier, wherein the carrier core material A two-component developer, wherein the coating layer of is composed of an acrylic resin.

[7] An image forming method for visualizing an electrostatic latent image formed on a photoreceptor by using the two-component developer according to any one of [1] to [6]. According to another aspect of the present invention, there is provided the following relationship between the wear amount of the coating layer of the carrier core material and the toner adhesion amount on the transfer material.

0.6 <a2 / a1 <0.97 a1 = (P8-P10) / (R10-R8) a2 = (P6-P8) / (R8-R6) [wherein R10 and P10 are image formations] Represents the amount of the coating layer of the carrier core material in the initial stage before being supplied to the toner, and the amount of toner adhered on the transfer material. R8 and P8 are the values when the coating layer of the carrier core material is worn by 20% from the initial stage. The amount of the coating layer of the carrier core material and the toner adhesion amount are represented by R6 and P6.
Represents the amount of the coating layer of the carrier core material and the toner adhesion amount when the coating layer of the carrier core material is 40% worn from the initial stage. [8] The electrostatic latent image formed on the photoconductor is recorded in the above [1] to
An image forming method for visualizing an image using the two-component developer according to any one of [6], wherein the amount of wear of the coating layer of the carrier core material and the variation of the carrier resistance value are between And an image forming method having the following relationship.

0.6 <log | b2 / b1 | <0.97 b1 = (S10-S8) / (R10-R8) b2 = (S8-S6) / (R8-R6) [wherein R10 and S10] Represents the amount of the carrier core material coating layer and the carrier resistance value in the initial stage before being subjected to image formation, and R8 and S8 represent the carrier core when the coating layer of the carrier core material is worn by 20% from the initial stage. Represents the amount of the coating layer of the material and the carrier resistance value, and R6 and S6 represent the amount of the coating layer of the carrier core material and the carrier resistance value when the coating layer of the carrier core material wears 40% from the initial stage. ]

[9] The electrostatic latent image formed on the photoreceptor is described in the above [1] to
An image forming method for forming a visible image using the two-component developer according to any one of [6], wherein the two-component developer is recycled.

[10] An image forming method for visualizing an electrostatic latent image formed on a photoreceptor by using the two-component developer according to any one of [1] to [6]. An image forming method, wherein the latent image is formed on the photoconductor by digital exposure.

[11] The toner has a number average particle diameter of 3 to 9 μm. [1] to [6]
The two-component developer according to any one of 1.

[12] The two-component system according to any one of [1] to [6], wherein the toner is obtained by polymerizing at least a polymerizable monomer in an aqueous medium. Developer.

[13] The two-component system according to any one of the above [1] to [6], wherein the toner is obtained by aggregating and fusing at least resin particles in an aqueous medium. Developer.

[14] The toner is obtained by salting out / fusing resin particles and colorant particles formed through at least a step of polymerizing a polymerizable monomer. The two-component developer according to any one of [1] to [6].

[15] The toner is obtained by salting out / fusing resin particles and colorant particles obtained by a multi-stage polymerization method.
The two-component developer according to any one of [6].

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The carrier used in the two-component developer of the present invention does not allow the coating layer on the carrier core material to contain the metal oxide in the coating layer at a uniform concentration in the layer, It is designed to have a concentration gradient within. As a result, the toner is stably attached to the transfer material without being affected by the repeated image formation, thereby stabilizing the image density.

In the present invention, the amount of toner adhered onto the transfer material during image formation is 0.4 to 0.8 m per unit area of the transfer material regardless of the amount of wear of the coating layer of the carrier core material.
g / cm ² , more preferably 0.5 to 0.7 mg / cm ^2.
It has been found that it has the ability to stably maintain the adhered amount of. Here, the toner adhesion amount on the transfer material is measured by evaluating the toner adhesion amount on a patch having a specific area. Specifically, the toner adhesion amount on the transfer material is unfixed by 3 cm × 4 cm by the image forming apparatus. A patch of a solid image is created, the toner adhered on the patch is blown off by an air gun, and the toner adhesion amount is calculated from the difference in mass before and after that.

The amount of toner adhered to the transfer material is calculated by the following formula. That is, toner adhesion amount on transfer material (mg / cm ² ) = {(mass of transfer material having unfixed image)-(mass of transfer material)} (mg) / patch area (cm ² ) As a result of a detailed study of the relationship between the amount of wear of the carrier core coating layer and the amount of toner adhering to the transfer material due to image formation, the amount of wear of the carrier core coating layer and the amount of coating layer wear The inventors have found that the relationship between the change in the amount of toner adhering to the transfer material during the above period has the following relationship. That is, it has been found that there is a relationship of 0.6 <a2 / a1 <0.97.

Here, a1 represents the ratio of the amount of change in the amount of toner adhered to the transfer material to the amount of wear of the coating layer of the carrier core material when the coating layer of the carrier core material has worn 20% from the initial stage. a2 indicates the ratio of the amount of change in the amount of toner adhered to the transfer material to the amount of wear of the coating layer of the carrier core material when the amount of wear of the coating layer of the carrier core material is reduced by 20% from the initial stage. Yes, and expressed as follows:

A1 = (P8-P10) / (R10-R8) a2 = (P6-P8) / (R8-R6) Here, the amount of the coating layer in the initial stage before being subjected to image formation is R10, The amount of toner adhering to the transfer material at the initial stage is P10, and the amount of the coating layer when the coating layer of the carrier core material is 20% worn is R8, and the amount of toner attached to the transfer material when 20% is worn Is denoted by P8, the amount of wear when the coating layer of the carrier core material is worn by 40% is denoted by R6, and the amount of toner adhered to the transfer material at 40% is denoted by P6.

In the present invention, the value of a2 / a1 is 0.6 to
It was found that the effect within the range of 0.97 reproduces the effect found in the present invention, and more preferably 0.8 to 0.9.
It is within the range of 5. When the value of a2 / a1 does not reach 0.6, the toner adhesion amount has a tendency to drastically decrease at a certain point in the repeated image formation.
When the value of a2 / a1 exceeds 0.97, the toner adhesion amount does not decrease, but gradation deteriorates and the image quality deteriorates. Therefore, the effect found in the present invention is reproduced. Is extremely difficult, which is not preferable.

Further, by designing the coating layer of the carrier core material as described above, the resistance of the carrier is imparted while imparting appropriate durability to the carrier even if the coating layer is worn away by repeated image formation. The resistance value does not fluctuate and the resistance value can be stably maintained for a long period of time against repeated image formation, and as a result, it is possible to stably suppress the occurrence of fog on the image for a long period of time. did.

Further, in the present invention, as a result of detailed examination of the relationship between the wear amount of the coating layer of the carrier core material and the resistance value of the carrier due to image formation, the wear amount of the coating layer of the carrier core material and the coating layer It has been found that there is the following relationship with the amount of change in the resistance value of the carrier during wear. That is, 0.6 <log | b2 / b1 | <0.97, where b1 is the amount of the carrier with respect to the amount of wear of the coating layer of the carrier core material when the coating layer of the carrier core material has worn 20% from the initial stage. B2 is the ratio of the amount of change in the carrier resistance value to the amount of wear of the coating layer of the carrier core material when the amount of wear of the coating layer of the carrier core material has been reduced by 40% from the initial stage. It is shown, and is expressed as follows.

B1 = (S10-S8) / (R10-R8) b2 = (S8-S6) / (R8-R6) Here, the amount of the coating layer in the initial stage before being subjected to image formation is R10, Let S10 be the carrier resistance value in the initial stage, R8 be the amount of the coating layer when the coating layer of the carrier core material is 20% worn from the initial stage, and S be the carrier resistance value.
8. The amount of the coating layer when the coating layer of the carrier core material is 40% worn from the initial stage is represented by R6, and the carrier resistance value is represented by S6.

In the present invention, the value of log | b2 / b1 | is in the range of 0.6 to 0.97, and preferably 0.85 to 0.95. When log | b2 / b1 | is a value of less than 0.6, the carrier resistance value does not decrease even if the coating layer of the carrier core material wears out, and the high value is maintained, so that the developability in the latter half is secured. It becomes difficult to do so, and the charging property is significantly reduced. Also, log | b
When the value of 2 / b1 | is more than 0.97, the carrier resistance value is significantly reduced due to the wear of the coating layer of the carrier core material, so that the developability becomes too high and a preferable image is obtained. Is not obtained, and it is extremely difficult to reproduce the effect found in the present invention in any case, which is not preferable.

Further, according to the present invention, when the value of a2 / a1 or the value of log | b2 / b1 | falls within the range of 0.6 to 0.97, the carrier can be repeatedly used for a long time. It was found that the reduction of the resistance value was suppressed, and it was found that it has an effect of suppressing the occurrence of character fringes especially in the latter half of the carrier life.

The term "carrier life" as used herein means a spent generated when the carrier is repeatedly used for image formation, the coating layer of the carrier core material is worn, and the toner or the toner external additive adheres to the carrier surface. As a result, the carrier performance is degraded. The time when the carrier can no longer be used for image formation and needs to be replaced is called the life of the carrier.

In the present invention, the carrier resistance value is preferably 3.0 × 10 ^{13 to} 1.0 × 10 ¹⁰ Ω · c.
m, and more preferably 1.0 × 10 ^{13 to} 1.5 × 1
It is 0 ¹⁰ Ω · cm.

The method of measuring the resistance value of the carrier is measured by the following procedure. That is, 1 g of carrier is put into a measuring cell having a cross-sectional area of 1 cm ² .
Next, the height (h) of the carrier put into the cell is measured. Next, applying a load of 1 kg to the cell filled with the measurement material, applying a voltage (V) between the upper electrode and the lower electrode, and measuring the flowing current value (i), the resistance value was calculated from the following formula. To calculate.

Resistance (Ω · cm) = V / (i × h) The current value is the value 30 seconds after the voltage is applied, and the measurement environment condition is room temperature and normal humidity environment (20 ° C., 50 ° C.). % R
H).

The coating amount of the coating layer of the carrier core material of the present invention is 0.5 to 10 parts by mass, and more preferably 2 to 7 parts by mass with respect to the carrier.

In the carrier of the present invention, the surface of the carrier core material particles is coated with a resin to form a coating layer. The amount of the coating material thus formed on the surface of the core material particles, that is, the carrier. The coating amount of the core material coating layer is measured by a conventionally known method such as a dissolution method or a carbon analysis method.

The dissolution method is a method in which a carrier formed by coating a carrier core material with a resin is put in a good solvent for the coating resin to dissolve the coating layer, and the coating amount is calculated from the difference in mass. .

The specific procedure for measuring the coating amount by the dissolution method is as follows. 5g of resin-coated carrier in 100ml beaker
Add and stir. Add an appropriate amount of acetone to this, place a magnet on the bottom of the beaker, and fix the resin-coated carrier by magnetic force to the bottom of the beaker so that the resin-coated carrier does not flow out and elute only the resin coating layer. . The above operation is repeated until the resin coating layer is completely eluted. The magnetic particles remaining in the beaker are dried on a hot plate. The total mass of magnetic particles is measured. The coverage is calculated from the following formula.

Formula Coverage = {(A−B) / A} × 100 (mass%) A: Total mass of resin-coated carrier B: Total mass of magnetic material particles Carbon analysis method is a coating resin for carrier core material The carbon content in the resin is measured by using a carbon analyzer such as a carbon analyzer EMIA-521 type (manufactured by Horiba Ltd.), and a calibration curve is prepared in advance using a carrier having a known coating amount, and a resin-coated carrier is prepared. Is a method of calculating the carbon content of the carrier core material and calculating the coating amount of the carrier core material coating layer.

The present invention contains metal oxide particles in the coating layer of the carrier core material, and the metal oxide concentration in the coating layer has a concentration gradient in the layer. It is what That is, in the coating layer of the carrier core material constituting the carrier of the present invention,
At the interface between the coating layer and the surface of the carrier core material particles, the metal oxide concentration is the smallest in the coating layer, and the metal oxide concentration increases as the surface approaches the coating layer surface.

The metal oxide content in the coating layer of the carrier core material of the present invention is such that the coating layer has regions with different contents, but is 0 to 40% by mass, preferably 0 to Three
The content is 0% by mass. That is, when converted to the mass ratio, the metal oxide is 0 to 6, and preferably 0 to 5 with respect to the resin 10.

In the present invention, the metal oxide is contained in the coating layer of the carrier core material with a concentration gradient, but there may be a region where the concentration of the metal oxide is 0 in the coating layer. ,
In particular, the concentration of the metal oxide may be 0 at the interface with the core material particles.

The content of the metal oxide in the coating layer of the carrier core material of the present invention is characterized by having regions having different contents in the coating layer. The amount is achieved by changing the addition amount of the metal oxide particles added to the mixer during the step of forming the coating layer on the surface of the core material particles in the carrier manufacturing process. That is, when a resin with a small addition amount of metal oxide is used, a coating layer with a low metal oxide content concentration is formed, and when a coating layer is formed with a resin with a large addition amount of metal oxide, A coating layer with a high oxide content is formed. In addition, specific manufacturing examples of the coating layers having different metal oxide content concentrations are as described in Examples below.

Specific examples of metal oxide particles contained in the coating layer of the carrier core material used in the present invention include aluminum oxide, iron oxide, titanium oxide, and the like.
Particularly, titanium oxide is preferably used. Further, in the present invention, these metal oxide particles may be used alone or in combination, or may be used in any method.

The shape of the metal oxide particles used in the present invention is not particularly limited, but those having a spindle shape are preferably used. Here, the spindle-like shape refers to one having a ratio L1 / L2 of the longest diameter L1 and the shortest diameter L2 of 2 or more in the particle cross section. Here, the shape of the metal oxide particles is determined by scanning electron microscope (SE
It is also confirmed by M) that the shape of the measured metal oxide particles is spindle-shaped by connecting the image analysis apparatus to the apparatus.

The metal oxide particles preferably used in the present invention have a specific surface area of 90 to 1 in terms of BET specific surface area.
It is preferably 40 m ² / g, and the volume indicating the volume per unit mass is preferably 3.0 to 7.0 ml / g,
Further, those having an average primary particle diameter of about 15 nm calculated from the specific surface area assuming that the shape of the particles is spherical are preferably used.

Examples of the core material constituting the carrier of the present invention include conventionally known materials such as metals such as iron, ferrite and magnetite, and alloys of these metals with metals such as aluminum and lead. Of these, ferrite is particularly preferably used. Further, in the present invention, as the physical properties of the carrier core material, the volume average particle diameter is 15 to 10
0 μm, more preferably 25 to 80 μm, average particle size 60
Those having a μm and saturation magnetization of 65 emu / g level are preferably used.

Specific examples of the coating resin which constitutes the coating layer of the carrier core material of the present invention include styrene resins and their derivatives, (meth) acrylate resins and their derivatives,
Styrene- (meth) acrylate copolymer resin, silicone resin and its modified products, fluororesin, vinyl and vinylidene resins, olefin resins such as polyethylene and polypropylene, phenol resin, polyester resin,
Examples thereof include epoxy resins and amino resins. Of these, it is particularly preferable to use a (meth) acrylate resin.

Examples of the method for coating the carrier of the present invention include a fluidized bed type spray coating method, a dip coating method, a sinter type coating method and a dry type coating method, and the dry type coating method is particularly preferably used.

In the dry coating method, the coating material in the powder state and the core material particles are mixed and stirred without using the coating liquid,
In this method, a film of the coating material is formed on the surfaces of the core particles by repeatedly applying a mechanical impact force.

1 to 4 are schematic views of a high-speed stirring mixer equipped with stirring blades, which is preferably used for manufacturing the carrier of the present invention, but the carrier of the present invention is not limited to this apparatus and is manufactured. Absent.

The volume average particle diameter of the carrier is typically measured by a laser diffraction type particle size distribution measuring apparatus "HELOS" equipped with a wet disperser (SYMPATIC (SYMP).
(Made by ATEC)).

Next, the toner used in the present invention will be described. The toner particles used in the present invention have a number average particle diameter of 3 to 9 μm, preferably 4.5 to 8.5 μm, and more preferably 5 to 8 μm. This particle size is a coagulant (salting out agent) in the toner manufacturing method.
Can be controlled by the concentration, the addition amount of the organic solvent, the fusion time, and the composition of the polymer.

In the present invention, it was found that when the number average particle diameter of the toner particles is 3 to 9 μm, the adhesion of the toner to the carrier during the image formation is effectively promoted. It has been found that the transfer efficiency at the time of forming a photographic image is improved, the halftone image quality is improved, and the image quality of fine lines and dots is improved. The toner particle size distribution is calculated and the number average particle size is measured using a Coulter Counter TA-II, Coulter Multisizer (both manufactured by Coulter Co., Ltd.), SLAD1100 (laser diffraction particle size measurement device manufactured by Shimadzu Corp.) and the like. Can be used to measure. In the present invention, a Coulter Multisizer is used, and an interface (manufactured by Nikkaki Co., Ltd.) for outputting a particle size distribution and a personal computer are connected and measured and calculated.

Next, the method for producing the toner of the present invention will be described. The toner of the present invention is obtained by polymerizing at least a polymerizable monomer in an aqueous medium, and this production method is to prepare resin particles by polymerizing the polymerizable monomer by a suspension polymerization method. Alternatively, emulsion polymerization or miniemulsion polymerization of the monomer is performed in a liquid (in an aqueous medium) containing an emulsion of the necessary additives to prepare fine resin particles, and charge as necessary. After adding the controllable resin particles,
The resin particles are manufactured by a method in which an organic solvent, a coagulant such as salts, etc. are added to coagulate and fuse the resin particles.

In the method for producing a toner of the present invention, at least the crystalline resin is dissolved in the polymerizable monomer, and then the composite resin fine particles and the colorant particles formed through the step of polymerizing the polymerizable monomer are used. It is obtained by salting out / fusing. The toner of the present invention is one in which a crystalline substance is dissolved in a polymerizable monomer, but it may be one which is dissolved and dissolved, or one which is melted and dissolved.

In the method for producing a toner of the present invention, the composite resin fine particles obtained by the multi-step polymerization method and the colorant particles are salted out / fused, and the multi-step polymerization method will be described below. The “aqueous medium” as referred to in the present invention means one containing at least 50% by mass of water.

<Production Method of Composite Resin Particles Obtained by Multi-Stage Polymerization Method> The production method of the toner of the present invention comprises the following steps.

1: multi-stage polymerization step 2: salting out / fusing composite resin particles and colorant particles to obtain toner particles Salting out / fusing step 3: filtering the toner particles from a dispersion system of toner particles Then
A filtration / washing step for removing a surfactant and the like from the toner particles 4: a drying step for drying the washed toner particles 5: a step of adding an external additive to the dried toner particles.

Each step will be described in detail below. [Multistage Polymerization Step] The multistage polymerization step is a polymerization method carried out in order to expand the molecular weight distribution of the resin particles in order to obtain a toner in which offset generation is prevented. That is, the polymerization reaction is performed in multiple stages in order to form a phase having different molecular weight distributions in one resin particle, and the obtained resin particle has a molecular weight gradient from the center of the particle toward the surface layer. It is intended to be formed. For example, a method of forming a low molecular weight surface layer by first adding a polymerizable monomer and a chain transfer agent after obtaining a high molecular weight resin particle dispersion liquid is adopted.

In the present invention, it is preferable to employ a multi-step polymerization method of three or more steps from the viewpoint of production stability and crushing strength of the obtained toner. The three-step polymerization method will be described below. From the viewpoint of crushing strength, the toner obtained by the three-step polymerization reaction preferably has a lower molecular weight toward the surface layer.

<Three-step polymerization method> The three-step polymerization method comprises a central portion (nucleus) formed of a high molecular weight resin, an intermediate layer containing a crystalline substance, and an outer layer (shell) formed of a low molecular weight resin. It is a method for producing composite resin particles. The toner of the present invention exists as the composite resin particles as described above.

This method will be described in detail. First, a dispersion liquid of resin particles obtained by a polymerization treatment (first-stage polymerization) according to a conventional method is added to an aqueous medium (for example, an aqueous solution of a surfactant). Along with the addition of the above, in the above aqueous medium, a monomer solution obtained by dissolving a crystalline substance in a monomer is dispersed in oil droplets, and then this system is subjected to a polymerization treatment (second-stage polymerization) to obtain a resin. A coating layer (intermediate layer) made of a resin (monomer polymer) containing a crystalline substance is formed on the surface of the particles (core particles) to form a composite resin particle (high molecular weight resin-intermediate molecular weight resin). Prepare the dispersion.

Then, a polymerization initiator and a monomer for obtaining a low molecular weight resin are added to the obtained dispersion liquid of the composite resin particles, and the monomer is subjected to a polymerization treatment in the presence of the composite resin particles (first). By three-step polymerization), a coating layer made of a low molecular weight resin (polymer of monomer) is formed on the surface of the composite resin particles. In the above method, by incorporating an intermediate layer, the crystalline substance can be dispersed finely and uniformly, which is preferable.

One of the features of the method for producing a toner according to the present invention is to polymerize a polymerizable monomer in an aqueous medium. That is, when the resin particles (nucleus particles) or the coating layer (intermediate layer) containing the crystalline substance are formed, the crystalline substance is dissolved in the monomer, and the resulting monomer solution is used as an oil in an aqueous medium. In this method, latex particles are obtained by dispersing in drops, adding a polymerization initiator to this system, and subjecting to a polymerization treatment.

The aqueous medium referred to in the present invention means water 50 to 10
A medium composed of 0 mass% and a water-soluble organic solvent of 0 to 50 mass%. As the water-soluble organic solvent, for example, methanol, ethanol, isopropanol, butanol,
Acetone, methyl ethyl ketone, tetrahydrofuran and the like can be exemplified, and an alcohol-based organic solvent that does not dissolve the obtained resin is preferable.

As a suitable polymerization method for forming resin particles or a coating layer containing a crystalline substance, the crystalline substance is dissolved in an aqueous medium in which a surfactant having a concentration below the critical micelle concentration is dissolved. A monomer solution dissolved in a monomer is dispersed into oil droplets using mechanical energy to prepare a dispersion liquid, and a water-soluble polymerization initiator is added to the obtained dispersion liquid to A method of radical polymerization (hereinafter, referred to as “miniemulsion method” in the present invention) can be mentioned, and the effects of the present invention can be exhibited more preferably. In the above method, an oil-soluble polymerization initiator may be used instead of the water-soluble polymerization initiator or together with the water-soluble polymerization initiator.

According to the mini-emulsion method of mechanically forming oil droplets, unlike the usual emulsion polymerization method, the crystalline substance dissolved in the oil phase is less desorbed and the formed resin particles or coating layer A sufficient amount of crystalline substance can be introduced therein.

The disperser for dispersing oil droplets by mechanical energy is not particularly limited, and for example, an agitator "CLEARMIX" (M -Technique Co., Ltd.), an ultrasonic disperser, a mechanical homogenizer, a Manton Gaulin, a pressure homogenizer, and the like. The dispersed particle size is 1
0 to 1000 nm, preferably 50 to 1000 n
m, and more preferably 30 to 300 nm. By giving a distribution to the dispersed particle diameter, the phase separation structure of the crystalline substance in the toner particles, that is, the Feret diameter, the shape coefficient, and the variation coefficient thereof may be controlled.

As another polymerization method for forming the resin particles containing the crystalline substance or the coating layer, known methods such as emulsion polymerization method, suspension polymerization method and seed polymerization method can be adopted. . In addition, these polymerization methods can also be adopted to obtain resin particles (core particles) or a coating layer forming the composite resin particles, which does not contain a crystalline substance.

The particle size of the composite resin particles obtained in this polymerization step is 10 to 10 in terms of mass average particle size measured by using an electrophoretic light scattering photometer "ELS-800" (manufactured by Otsuka Electronics Co., Ltd.).
It is preferably in the range of 1000 nm.

Further, the glass transition temperature (T
g) is preferably in the range of 48 to 74 ° C, more preferably 52 to 64 ° C.

The softening point of the composite resin particles is 95-14.
It is preferably in the range of 0 ° C. The toner of the present invention is
It is obtained by forming a resin layer by fusing resin particles by a salting out / fusing method on the surfaces of the resin and the colored particles, which will be described below. [Salting-out / fusion-bonding step] In this salting-out / fusion-bonding step, the composite resin particles obtained by the multi-stage polymerization step and the colorant particles are salted-out / fusion-bonded (simultaneously causing salting-out and fusion-bonding). Let)
This is a process of obtaining amorphous (non-spherical) toner particles.

The term "salting out / fusion" as used in the present invention means that salting out (aggregation of particles) and fusion (disappearance of interface between particles) occur simultaneously, or salting out and fusion occur simultaneously. Refers to an act. In order to perform salting out and fusion at the same time, particles (composite resin particles, colorant particles) are formed under the temperature condition of the glass transition temperature (Tg) of the resin constituting the composite resin particles or higher.
Need to be aggregated.

In this salting out / fusion step, internal additive particles such as charge control agent (fine particles having a number average primary particle size of about 10 to 1000 nm) are salted out / fused together with the composite resin particles and the colorant particles. You may let me. Also, the colorant particles are
The surface may be modified, and as the surface modifier, a conventionally known one can be used.

In the present invention, after the particle growth is finished, a dispersion of resin particles may be added to cover the resin layer on the colored particles to perform fusion bonding. [Aging step] Aging step Is a step subsequent to the salting-out / fusion step, in which the temperature is kept near the melting point of the crystalline substance, preferably the melting point ± 20 ° C. even after the fusion of the resin particles, and stirring is continued at a constant strength. , A step of phase-separating a crystalline substance. In this step, it is possible to control the Feret diameter, the shape factor and the variation coefficient of the crystalline substance. [Colorant Fine Particles] The colorant fine particles used for obtaining the toner of the present invention are formed by using a dispersing device for finely dispersing the colorant fine particles in an aqueous medium containing a surfactant. . That is, the dispersing device for finely dispersing the colorant fine particles preferably used in the toner of the present invention is
A shearing force is generated by the screen that defines the stirring chamber and the rotor that rotates at high speed in the stirring chamber, and the action of the shearing force (in addition, the action of the collision force, the pressure fluctuation, the cavitation, and the potential core) causes the colorant to be removed. Fine particles are obtained by finely dispersing it in an aqueous medium containing a surfactant.

Here, the surfactant contained in the aqueous medium in which the colorant particles are dispersed has a critical micelle concentration (CMC).
The surfactant is dissolved at the above concentration, and the same surfactant as that used in the polymerization step can be used as the surfactant.

The weight average particle diameter (dispersed particle diameter) of the colorant fine particles is 30 to 500 nm, preferably 50 to 30.
It is set to 0 nm. The weight average particle diameter of the colorant fine particles is 30.
When the weight average particle diameter is more than 500 nm, the colorant particles are not appropriately dispersed in the water system and easily settle because the colorant particles are more likely to float in the water system when the particle size is less than 500 nm. In addition, it becomes difficult to introduce the colorant into the toner particles. Under such conditions, the colorant particles are not incorporated into the toner particles and remain free in the aqueous system, which is not preferable. The weight average particle diameter of the colorant fine particles is measured using an electrophoretic light scattering photometer "ELS-800" (manufactured by Otsuka Electronics Co., Ltd.).

The colorant fine particles used in the toner of the present invention are prepared by introducing the colorant into an aqueous medium containing a surface active agent, and then preliminarily dispersing (coarsely dispersing) it with a propeller stirrer or the like. A predispersion liquid in which agglomerated particles are dispersed is produced. A preferable dispersion state is obtained by supplying the preliminary dispersion liquid to an agitator equipped with a screen for partitioning and forming an agitator chamber and a rotor rotating at high speed in the agitator chamber, and performing a dispersion treatment (fine dispersion treatment) by the agitator. A dispersion of fine colorant particles having is prepared.

In the present invention, as a stirring device for dispersion treatment for obtaining colorant fine particles having a preferable dispersion state, "CLEAR MIX" (manufactured by M Technique Co., Ltd.) can be mentioned. This "Clearmix" has a rotor (stirring blade) that rotates at high speed and a fixed screen (fixed ring) that surrounds the rotor, and applies shear force, collision force, pressure fluctuation, cavitation and It has a structure that imparts the action of a potential core, and these actions act synergistically to effectively emulsify and disperse the liquid to be treated.

Further, in order to obtain colorant fine particles preferably used in the toner of the present invention, a dispersion container equipped with a stirrer equipped with a screen and a rotor is used, and the dispersion medium is contained in an aqueous medium. Alternatively, a batch-type dispersion treatment in which a colorant (an aqueous medium containing the colorant) is jetted from the stirring chamber of the stirring device may be performed.

The colorant particles are subjected to salting-out / fusion treatment in a state of being dispersed in an aqueous medium. The aqueous medium in which the colorant particles are dispersed is preferably an aqueous solution in which the surfactant is dissolved at a concentration equal to or higher than the critical micelle concentration (CMC).

The disperser used for the dispersion treatment of the colorant particles is not particularly limited, but preferably a stirring device "CLEARMIX (CLEAR) equipped with a rotor rotating at a high speed.
MIX) ”(manufactured by M Technique Co., Ltd.), ultrasonic disperser, mechanical homogenizer, manton-goulin, pressure homogenizer such as pressure homogenizer, and medium type disperser such as Getzman mill and diamond fine mill.

In order to salt out / fuse the composite resin particles and the colorant particles, the salting out agent (aggregating agent) having a critical coagulation concentration or more is added to the dispersion liquid in which the composite resin particles and the colorant particles are dispersed. ) Is added and the dispersion is heated to the glass transition temperature (Tg) or higher of the composite resin particles.

The temperature range suitable for salting out / fusing is (Tg + 10) to (Tg + 50 ° C.), and particularly preferably (Tg + 15) to (Tg + 40 ° C.). In addition, an organic solvent infinitely soluble in water may be added in order to effectively carry out the fusion.

In the present invention, the resin particles and the colorant are salted out, aggregated and fused in an aqueous medium to obtain colored particles (in the present invention, referred to as toner particles), and then the toner particles are water-based. When separated from the medium, it is preferably carried out at a temperature not lower than the Kraft point of the surfactant present in the aqueous medium, and more preferably at a temperature range of Kraft point to (Craft point + 20 ° C.). is there.

The Kraft point is the temperature at which the aqueous solution containing the surfactant begins to turn cloudy, and the Kraft point is measured as follows.

<Measurement of Kraft Point> An aqueous medium used in the steps of salting out, aggregating, and fusing is prepared by adding an actual amount of the aggregating agent to a solution of a surfactant, and the solution is prepared at 1 ° C. Stored for 5 days. The solution was then heated slowly with stirring until it became transparent. The temperature at which the solution became clear is defined as the Kraft point.

From the viewpoint of suppressing excessive charging of the toner particles and imparting a uniform charging property, the toner for developing an electrostatic charge image of the present invention is particularly designed to stabilize and maintain the charging property with respect to the environment. Metal element described above (as a form, metal,
250 to 20 in the toner)
The content is preferably 000 ppm, more preferably 800 to 5000 ppm.

In the present invention, the total value of the divalent (trivalent) metal element used as the aggregating agent and the monovalent metal element added as an aggregating terminator described later is 350 to 35,000 pp.
It is preferably m. X-ray fluorescence analyzer "System 3270" is used to measure the amount of residual metal ions in the toner.
It can be determined by measuring the intensity of fluorescent X-ray emitted from the metal species of the metal salt used as the aggregating agent (for example, calcium derived from calcium chloride) using [Rigaku Denki Kogyo KK]. As a specific measuring method, a plurality of toners having a known content ratio of the aggregating agent metal salt are prepared, 5 g of each toner is pelletized, the content ratio (mass ppm) of the aggregating agent metal salt, and the metal species of the metal salt. The relationship (calibration curve) with the fluorescent X-ray intensity (peak intensity) from is measured. Next, the toner (sample) whose content ratio of the aggregating agent metal salt is to be measured is pelletized in the same manner, and the fluorescent X-ray intensity from the metal species of the aggregating agent metal salt is measured to determine the content ratio, that is, "metal ion remaining in the toner You can ask for the "quantity".

[Filtration / Washing Step] In this filtration / washing step, a filtering treatment for filtering the toner particles from the dispersion system of the toner particles obtained in the above-mentioned step, and the filtered toner particles (cake-shaped A cleaning process is performed to remove deposits such as surfactants and salting-out agents from the aggregate. Here, the filtration method is not particularly limited, such as a centrifugal separation method, a vacuum filtration method using a Nutsche or the like, or a filtration method using a filter press or the like.

[Drying Step] In this step, the washed toner particles are dried.

Examples of the dryer used in this step include a spray dryer, a vacuum freeze dryer, a vacuum dryer and the like. A stationary shelf dryer, a mobile shelf dryer, a fluidized bed dryer, a rotary dryer It is preferable to use a dryer or a stirring dryer.

The water content of the dried toner particles is preferably 5% by mass or less, more preferably 2% by mass or less.

The toner particles that have been dried are
When the aggregates are aggregated by the weak attraction between particles, the aggregates may be crushed. Here, as the disintegration processing device,
A mechanical crushing device such as a jet mill, a Henschel mixer, a coffee mill or a food processor can be used.

The toner of the present invention forms composite resin particles in the absence of a colorant, adds the dispersion liquid of the colorant particles to the dispersion liquid of the composite resin particles, and mixes the composite resin particles and the colorant particles. It is preferably prepared by salting out / fusing.

Thus, by carrying out the preparation of the composite resin particles in a system in which no colorant is present, the polymerization reaction for obtaining the composite resin particles is not hindered. Therefore, according to the toner of the present invention, the excellent offset resistance is not impaired, and the contamination of the fixing device and the image stain due to the accumulation of the toner do not occur.

Further, as a result of the polymerization reaction being surely carried out to obtain the composite resin particles, no monomer or oligomer remains in the obtained toner particles, and the image forming method using the toner can be used. No offensive odor is generated in the heat fixing step.

Further, the obtained toner particles have uniform surface characteristics and a sharp charge amount distribution, so that an image having excellent sharpness can be formed for a long period of time. Such a toner having a uniform composition, molecular weight, and surface characteristics among toner particles maintains good adhesiveness (high fixing strength) to an image support in an image forming method including a fixing step by a contact heating method. However, it is possible to improve the anti-offset property and the wrapping prevention property, and it is possible to obtain an image having an appropriate gloss.

Next, each constituent factor used in the toner manufacturing process will be described in detail. (Polymerizable Monomer) As the polymerizable monomer for producing the resin (binder) used in the present invention, a hydrophobic monomer is used as an essential constituent component, and a crosslinkable monomer is added as necessary. Used. Further, it is desirable to contain at least one kind of monomer having an acidic polar group or basic polar group in the structure as described below. (1) Hydrophobic Monomer The hydrophobic monomer constituting the monomer component is not particularly limited, and conventionally known monomers can be used. Further, one kind or a combination of two or more kinds can be used so as to satisfy the required characteristics.

Specifically, a monovinyl aromatic monomer,
(Meth) acrylic acid ester-based monomer, vinyl ester-based monomer, vinyl ether-based monomer, monoolefin-based monomer, diolefin-based monomer, halogenated olefin-based monomer, etc. may be used. it can.

Examples of vinyl aromatic monomers include:
Styrene, o-methylstyrene, m-methylstyrene,
p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, p-ethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n- Examples thereof include styrene-based monomers such as octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, 2,4-dimethylstyrene, and 3,4-dichlorostyrene, and derivatives thereof. .

Examples of the (meth) acrylic acid ester type monomer include acrylic acid, methacrylic acid, methyl acrylate,
Ethyl acrylate, butyl acrylate, acrylic acid-2
-Ethylhexyl, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, γ-aminopropyl acrylate, methacrylic acid Stearyl, dimethylaminoethyl methacrylate,
Diethylaminoethyl methacrylate and the like can be mentioned.

Examples of the vinyl ester-based monomer include vinyl acetate, vinyl propionate, vinyl benzoate and the like. Examples of the vinyl ether-based monomer include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether. Etc.

As the mono-olefin type monomer, ethylene, propylene, isobutylene, 1-butene, 1-
Examples thereof include pentene and 4-methyl-1-pentene, and examples of the diolefin-based monomer include butadiene, isoprene and chloroprene. (2) Crosslinkable Monomer A crosslinkable monomer may be added to improve the properties of the resin particles. Examples of the crosslinkable monomer include those having two or more unsaturated bonds such as divinylbenzene, divinylnaphthalene, divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate and diallyl phthalate. (3) Monomer having acidic polar group As the monomer having an acidic polar group, (a) an α, β-ethylenically unsaturated compound having a carboxyl group (—COOH), and (b) a sulfone group Mention may be made of α, β-ethylenically unsaturated compounds having (-SO ₃ H).

Α, β-having a carboxyl group (a)
Examples of ethylenically unsaturated compounds include acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid,
Examples thereof include cinnamic acid, maleic acid monobutyl ester, maleic acid monooctyl ester, and metal salts thereof such as Na and Zn.

Examples of the α, β-ethylenically unsaturated compound having a sulfone group (b) include sulfonated styrene and its Na salt, allylsulfosuccinic acid, octyl allylsulfosuccinate, and their Na salts. Can be mentioned. (4) Monomer having basic polar group As the monomer having a basic polar group, (a) an amine group or a quaternary ammonium group having 1 to 1 carbon atoms
2, preferably 2 to 8, particularly preferably 2 (meth) acrylic acid ester of an aliphatic alcohol, (b) (meth)
Acrylic amide or optionally 1 to 1 carbon atoms on N
(Meth) acrylic acid amide mono- or di-substituted with 18 alkyl groups, (c) vinyl compound substituted with a heterocyclic group having N as a ring member, and (d) N, N-diallyl-alkylamine or a compound thereof. A quaternary ammonium salt can be illustrated. Among them, (meth) of aliphatic alcohol having an amine group or a quaternary ammonium group of (a)
Acrylic acid esters are preferred as the monomer having a basic polar group.

Examples of the (meth) acrylic acid ester of an aliphatic alcohol having an amine group or a quaternary ammonium group of (a) include dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and the above. Quaternary ammonium salt of 4 compounds, 3-dimethylaminophenyl acrylate, 2-hydroxy-
3-methacryloxypropyl trimethyl ammonium salt etc. can be mentioned.

Examples of the (meth) acrylic acid amide of (b) or the (meth) acrylic acid amide optionally substituted with mono- or dialkyl on N include acrylamide, N-butylacrylamide, N, N-dibutylacrylamide, piperidylacrylamide, Methacrylamide, N-butylmethacrylamide, N, N-dimethylacrylamide,
N-octadecyl acrylamide etc. can be mentioned.

Examples of the vinyl compound (c) substituted with a heterocyclic group having N as a ring member include vinylpyridine, vinylpyrrolidone, vinyl-N-methylpyridinium chloride and vinyl-N-ethylpyridinium chloride. You can

Examples of the N, N-diallyl-alkylamine of (d) include N, N-diallylmethylammonium chloride and N, N-diallylethylammonium chloride.

(Polymerization Initiator) The radical polymerization initiator used in the present invention can be appropriately used if it is water-soluble. For example, persulfates (eg, potassium persulfate, ammonium persulfate, etc.), azo compounds (eg, 4,4 ′)
-Azobis-4-cyanovaleric acid and its salts, 2,2'-azobis (2-amidinopropane) salt, etc.), peroxide compounds and the like. Further, the above radical polymerization initiator can be combined with a reducing agent as required to form a redox initiator. By using the redox type initiator, the polymerization activity can be increased, the polymerization temperature can be lowered, and further the polymerization time can be shortened, which is a preferable aspect.

The polymerization temperature is not particularly limited as long as it is at least the minimum radical generation temperature of the polymerization initiator, but is in the range of 50 to 90 ° C., for example. However, it is also possible to carry out the polymerization at room temperature or higher by using a room temperature-initiated polymerization initiator in which a hydrogen peroxide-reducing agent (ascorbic acid or the like) is combined.

(Chain transfer agent) A known chain transfer agent can be used for the purpose of adjusting the molecular weight. The chain transfer agent is not particularly limited, for example, octyl mercaptan, dodecyl mercaptan,
A compound having a mercapto group such as tert-dodecyl mercaptan is used. In particular, a compound having a mercapto group is preferably used because it suppresses an odor at the time of heating and fixing, a toner having a sharp molecular weight distribution is obtained, and it has excellent storage stability, fixing strength, and offset resistance. Preferred are, for example, ethyl thioglycolate,
The mercapto group of propyl thioglycolate, propyl thioglycolate, butyl thioglycolate, t-butyl thioglycolate, 2-ethylhexyl thioglycolate, octyl thioglycolate, decyl thioglycolate, dodecyl thioglycolate, ethylene glycol is used. Examples thereof include compounds having a mercapto group of neopentyl glycol, and compounds having a mercapto group of pentaerythritol. Of these, from the viewpoint of suppressing odor during toner heat fixing, n-octyl-
Particularly preferred is 3-mercaptopropionic acid ester.

(Surfactant) It is preferable to use a surfactant to disperse oil droplets in an aqueous medium in order to carry out miniemulsion polymerization using the above-mentioned polymerizable monomer. The surfactant that can be used in this case is not particularly limited, but the following ionic surfactants can be mentioned as examples of suitable compounds.

Examples of the ionic surfactant include sulfonates (sodium dodecylbenzene sulfonate,
Aryl alkyl polyether sodium sulfonate,
3,3-disulfone diphenylurea-4,4-diazo-
Sodium bis-amino-8-naphthol-6-sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol -6-
Sodium sulfonate, etc.), sulfate ester salts (sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc.),
Examples thereof include fatty acid salts (sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, calcium oleate, etc.).

In the present invention, the surfactants represented by the following general formulas (1) and (2) are particularly preferably used. General formula (1) R ₁ (OR ₂ ) nOSO ₄ M General formula (2) R ₁ (OR ₂ ) nSO ₃ M In general formulas (1) and (2), R ₁ has 6 to 22 carbon atoms.
Is preferably an alkyl group or an arylalkyl group having 8 to 20 carbon atoms, and more preferably an alkyl group or an arylalkyl group having 9 to 16 carbon atoms.

Examples of the alkyl group having 6 to 22 carbon atoms represented by R ₁ include n-hexyl group, n-heptyl group, n-octyl group, n-decyl group, n-undecyl group and n-hexadecyl group. Group, cyclopropyl group, cyclopentyl group, cyclohexyl group and the like, and the arylalkyl group represented by R1 includes benzyl group, diphenylmethyl group, cinnamyl group, styryl group, trityl group, phenethyl group and the like.

In the general formulas (1) and (2), R ₂ represents an alkylene group having 2 to 6 carbon atoms, preferably an alkylene group having 2 to 3 carbon atoms. ₂ carbon atoms represented by R 2
Examples of the alkylene group of to 6 include ethylene group, trimethylene group, tetramethylene group, propylene group and ethylethylene group.

In the general formulas (1) and (2), n is 1 to
Although it is an integer of 11, it is preferably 2 to 10, more preferably 2 to 5, and particularly preferably 2 to 3.

In the general formulas (1) and (2), examples of the monovalent metal element represented by M include sodium, potassium and lithium. Among them, sodium is preferably used.

Specific examples of the surfactants represented by the general formulas (1) and (2) are shown below, but the invention is not limited thereto.

Compound (101): C ₁₀ H ₂₁ (OCH ₂ CH ₂ ) ₂ OSO ₃ Na Compound (102): C ₁₀ H ₂₁ (OCH ₂ CH ₂ ) ₃ OSO ₃ Na Compound (103): C ₁₀ H _{21 (OCH 2 CH 2) 2 SO} 3 Na compound _{(104): C 10 H 21} (OCH 2 CH 2) 3 SO 3 Na compound _{(105): C 8 H 17} (OCH 2 CH (CH 3)) 2 OSO 3 Na compound (106): C ₁₈ H ₃₇ (OCH ₂ CH ₂ ) ₂ OSO ₃ Na In the present invention, the toner charge retention function is kept in a good state, fog is suppressed under high temperature and high humidity, and transferability is improved. From the viewpoint of improving the charge stability and suppressing the increase in the charge amount under low temperature and low humidity and stabilizing the development amount, the electrostatic charge of the surfactant represented by the general formula (1) or (2) described above. Content in the image developing toner is 1 to 1000 ppm Preferably, more preferably from 5 to 500 ppm, particularly preferably 7～100Ppm.

In the present invention, by setting the amount of the surfactant contained in the toner within the above-mentioned range, the electrostatic property of the toner for developing an electrostatic charge image of the present invention is not influenced by the environment and is always It is possible to be applied and maintained in a uniform and stable state.

The content of the surfactant represented by the above general formulas (1) and (2) contained in the toner for developing an electrostatic charge image of the present invention is calculated by the following method. .

1 g of the toner is dissolved in 50 ml of chloroform, and the surfactant is extracted from the chloroform layer with 100 ml of ion-exchanged water. The extracted chloroform layer was extracted again with 100 ml of ion-exchanged water to obtain a total of 200 ml of extract liquid (water layer).
Dilute to 00 ml.

Using this diluted solution as a test solution, JIS 33
According to the method defined in Item 636, the color is developed with methylene blue, the absorbance is measured, and the content of the surfactant in the toner is measured from a separately prepared calibration curve.

The boundaries represented by the general formulas (1) and (2) are
The structure of the surfactant is ¹Using H-NMR
Then, the structure was determined.

In the present invention, a metal salt can be preferably used as an aggregating agent in the steps of salting out, aggregating and fusing resin particles from a dispersion liquid of resin particles prepared in an aqueous medium. It is further preferable to use a trivalent metal salt as the aggregating agent. The reason is that a divalent or trivalent metal salt is preferable to a monovalent metal salt because the critical aggregation concentration (coagulation value or coagulation point) is smaller.

Further, in the present invention, a nonionic surfactant may be used. Specifically, polyethylene oxide, polypropylene oxide, a combination of polypropylene oxide and polyethylene oxide, an ester of polyethylene glycol and higher fatty acid, an alkylphenol. Examples thereof include polyethylene oxide, higher fatty acid and polyethylene glycol ester, higher fatty acid and polypropylene oxide ester, and sorbitan ester.

In the present invention, these surfactants are mainly used as an emulsifier during emulsion polymerization, but may be used for other steps or for other purposes.

(Molecular Weight Distribution of Resin Particles and Toner) The toner of the present invention has a peak or shoulder of 10 in the molecular weight distribution.
20,000 to 1,000,000, and 1,000 to 5
It is preferable that the peak or shoulder of the molecular weight distribution is 100,000 to 1,000,000.
0, 25,000-150,000 and 1,000-5
It is preferably present at 10,000.

The molecular weight of the resin particles is 100,000 to
A resin containing at least a high molecular weight component having a peak or shoulder in the region of 1,000,000 and a low molecular weight component having a peak or shoulder in the region of 1,000 to less than 50,000 is preferable, and more preferably Is
It is preferable to use an intermediate molecular weight resin having a peak or shoulder in the portion of 15,000 to 100,000.

The method for measuring the molecular weight of the above-mentioned toner or resin is carried out by GP using THF (tetrahydrofuran) as a solvent.
Measurement by C (gel permeation chromatography) is preferable. That is, 1.0 ml of THF is added to 0.5 to 5 mg of the measurement sample, more specifically 1 mg, and stirred at room temperature using a magnetic stirrer or the like to sufficiently dissolve the sample. Next, pore size 0.45
After treatment with a 0.50 μm membrane filter,
Inject into GPC. The GPC measurement conditions are as follows: the column is stabilized at 40 ° C., THF is allowed to flow at a flow rate of 1.0 ml / min, and a sample having a concentration of 1 mg / ml is injected in an amount of about 100 μl. The column is preferably used in combination with a commercially available polystyrene gel column. For example, Shodex GPC KF-801, 80 manufactured by Showa Denko KK
2, 803, 804, 805, 806, 807 combination and TSKgel G1000H, G200 manufactured by Tosoh Corporation
0H, G3000H, G4000H, G5000H, G
6000H, G7000H, TSK guard co
Examples include a combination of lumn. As a detector, a refractive index detector (IR detector) or U
A V detector may be used. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated using a calibration curve prepared using monodisperse polystyrene standard particles. About 10 points may be used as polystyrene for preparing the calibration curve.

(Aggregating agent) In the present invention, a metal salt can be preferably used as an aggregating agent in the steps of salting out, aggregating and fusing resin particles from a dispersion liquid of resin particles prepared in an aqueous medium. It is further preferable to use a divalent or trivalent metal salt as the aggregating agent. The reason is that a divalent or trivalent metal salt is preferable to a monovalent metal salt because the critical aggregation concentration (coagulation value or coagulation point) is smaller.

The coagulant used in the present invention is, for example, a monovalent metal salt which is a salt of an alkali metal such as sodium, potassium and lithium, for example, a salt of an alkaline earth metal such as calcium and magnesium and manganese and copper. Examples thereof include divalent metal salts and trivalent metal salts such as iron and aluminum.

Specific examples of these metal salts are shown below.
Examples of the monovalent metal salt include sodium chloride, potassium chloride, lithium chloride, and examples of the divalent metal salt include calcium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate, and the like. Examples include aluminum chloride and iron chloride. These are appropriately selected according to the purpose, but divalent or trivalent metal salts having a small critical aggregation concentration are preferable.

The critical coagulation concentration referred to in the present invention is an index relating to the stability of the dispersion in the aqueous dispersion, and shows the addition concentration of the coagulant when the coagulant is added and the coagulation occurs. This critical coagulation concentration greatly changes depending on the latex itself and the dispersant. For example, it is described in Seizo Okamura et al., Polymer Chemistry 17,601 (1960),
The value can be known by following these descriptions.
Further, as another method, a desired salt is added to the target particle dispersion liquid while changing the concentration, and the ζ potential of the dispersion liquid is measured,
It is also possible to set the salt concentration at the point where the ζ potential changes as the critical aggregation concentration.

In the present invention, the polymer fine particle dispersion is treated with a metal salt so as to have a concentration higher than the critical aggregation concentration. At this time, of course, directly add the metal salt,
Whether to add as an aqueous solution is arbitrarily selected according to the purpose. When it is added as an aqueous solution, the added metal salt needs to have a critical coagulation concentration of the polymer particles or more with respect to the volume of the polymer particle dispersion and the total volume of the metal salt aqueous solution.

In the present invention, the concentration of the metal salt may be equal to or higher than the critical aggregation concentration, but is preferably 1.
The amount is 2 times or more, more preferably 1.5 times or more.

(Colorant) The toner of the present invention is obtained by salting out / fusing the above-mentioned composite resin particles and colorant particles. Examples of the colorant (colorant particles to be salted out / fused with the composite resin particles) constituting the toner of the present invention include various inorganic pigments, organic pigments and dyes.
As the inorganic pigment, conventionally known ones can be used. Specific inorganic pigments are exemplified below.

Examples of black pigments include furnace black, channel black, acetylene black,
Carbon black such as thermal black and lamp black, and magnetic powder such as magnetite and ferrite are also used.

These inorganic pigments may be used alone or in combination of two or more as desired. Further, the amount of the pigment added is 2 to 20% by mass, preferably 3 to 15% by mass, based on the polymer.

When used as a magnetic toner, the above-mentioned magnetite can be added. In this case, from the viewpoint of imparting a predetermined magnetic characteristic, 20 to 6 is contained in the toner.
It is preferable to add 0% by mass.

Conventionally known organic pigments and dyes can be used, and specific organic pigments and dyes are shown below.

As the magenta or red pigment,
For example, C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I.
Pigment Red 6, C.I. I. Pigment Red 7,
C. I. Pigment Red 15, C.I. I. Pigment Red 16, C.I. I. Pigment Red 48: 1, C.I.
I. Pigment Red 53: 1, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Red 122, C.I.
I. Pigment Red 123, C.I. I. Pigment Red 139, C.I. I. Pigment Red 144, C.I. I.
Pigment Red 149, C.I. I. Pigment Red 1
66, C.I. I. Pigment Red 177, C.I. I. Pigment Red 178, C.I. I. Pigment Red 222
Etc.

Examples of pigments for orange or yellow include C.I. I. Pigment Orange 31, C.I.
I. Pigment Orange 43, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I.
Pigment Yellow 14, C.I. I. Pigment Yellow 15, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 9
4, C.I. I. Pigment Yellow 138, C.I. I. Pigment Yellow 180, C.I. I. Pigment Yellow 1
85, C.I. I. Pigment Yellow 155, C.I. I. Pigment Yellow 156 and the like.

As a pigment for green or cyan,
For example, C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 1
5: 3, C.I. I. Pigment Blue 16, C.I. I. Pigment Blue 60, C.I. I. Pigment Green 7 and the like.

Examples of the dye include C.I. I. Solvent Red 1, 49, 52, 58, 63,
111, 122, C.I. I. Solvent yellow 1
9, the same 44, the same 77, the same 79, the same 81, the same 82, the same 9
3, ibid 98, ibid 103, ibid 104, ibid 112, ibid 16
2, C.I. I. Solvent Blue 25, 36, 60,
No. 70, No. 93, No. 95 and the like can be used, and a mixture thereof can also be used.

These organic pigments and dyes can be used alone or in combination of two or more as desired.
The amount of pigment added is 2 to 20% by mass based on the polymer.
And preferably 3 to 15% by mass.

The colorant (colorant particles) constituting the toner of the present invention may be surface-modified. As the surface modifier, conventionally known ones can be used, and specifically, a silane coupling agent, a titanium coupling agent, an aluminum coupling agent and the like can be preferably used. Examples of the silane coupling agent include alkoxysilanes such as methyltrimethoxysilane, phenyltrimethoxysilane, methylphenyldimethoxysilane and diphenyldimethoxysilane, siloxanes such as hexamethyldisiloxane, γ-chloropropyltrimethoxysilane and vinyltrisilane. Chlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane,
γ-ureidopropyltriethoxysilane and the like can be mentioned. As the titanium coupling agent, for example, TTS, 9S, 38S, 41B, 46B, 55, 138, which is commercially available under the trade name "Planeact" manufactured by Ajinomoto Co., Inc.
Commercial products A-1, B- manufactured by Nippon Soda Co., Ltd. such as S, 238S.
1, TOT, TST, TAA, TAT, TLA, TO
G, TBSTA, A-10, TBT, B-2, B-4,
B-7, B-10, TBSTA-400, TTS, TO
A-30, TSDMA, TTAB, TTOP and the like can be mentioned. As the aluminum coupling agent, for example,
Examples include "Planeact AL-M" manufactured by Ajinomoto Co., Inc.

The amount of these surface modifiers added is preferably 0.01 to 20% by mass, more preferably 0.1 to 5% by mass, based on the colorant. In addition, as a method for modifying the surface of the colorant particles, a method of adding a surface modifier to the dispersion liquid of the colorant particles and heating the system to react them can be mentioned. Colorant particles surface-modified in this way,
It is obtained by collecting by filtration, repeating washing treatment with the same solvent and filtration treatment, and then drying treatment.

(Crystalline Material) In the toner used in the present invention, resin particles containing a crystalline material are fused in an aqueous medium and the crystalline material is appropriately aggregated in an aging step to form a sea-island structure. It is preferable that the toner is a mixed toner. Thus, by salting out / fusing the resin particles containing the crystalline substance in the resin particles with the colorant particles in the aqueous medium, a toner in which the crystalline substance is finely dispersed can be obtained. Here, the aging step refers to a step of continuing stirring at a temperature within the range of the melting point of the crystalline substance ± 20 ° C even after the fusion of the resin particles.

In the toner of the present invention, as the crystalline substance having a releasing function, low molecular weight polypropylene (number average molecular weight = 1500 to 9000), low molecular weight polyethylene and the like are preferable, and the ester represented by the following formula is particularly preferable. It is a system compound.

R _1- (OCO-R ₂ ) n In the formula, n is 1 to 4
And is preferably an integer of 2 to 4, more preferably 3 to 4,
Especially preferred is 4. R ₁ and R ₂ each represent a hydrocarbon group which may have a substituent. R ₁ has 1 to 4 carbon atoms
0, preferably 1-20, more preferably 2-5. R ₂ has 1 to 40 carbon atoms, preferably 16 to 30 carbon atoms,
More preferably, it is 18 to 26.

Next, examples of typical compounds are shown below.

[0162]

[Chemical 1]

[0163]

[Chemical 2]

In the present invention, a crystalline polyester can be used as the crystalline substance. The crystalline polyester includes an aliphatic diol and an aliphatic dicarboxylic acid (including an acid anhydride and an acid chloride). And a polyester obtained by reacting

As the diol used for obtaining the crystalline polyester, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,
4-butanediol, 1,4-butenediol, neopentyl glycol, 1,5-pentane glycol, 1,
Examples include 6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, bisphenol Z, hydrogenated bisphenol A, and the like. it can.

Examples of the dicarboxylic acid used to obtain the crystalline polyester include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, sebacic acid, maleic acid and fumaric acid. , Citraconic acid, itaconic acid, glutacoic acid, n-dodecylsuccinic acid, n-dodecenylsuccinic acid, isododecylsuccinic acid, isododecenylsuccinic acid, n-octylsuccinic acid, n-octenylsuccinic acid, their acid anhydrides or Mention may be made of acid chlorides.

Particularly preferred crystalline polyesters are polyesters obtained by reacting 1,4-cyclohexanedimethanol and adipic acid, polyesters obtained by reacting 1,6-hexanediol and sebacic acid, and ethylene glycol. And polyesters obtained by reacting succinic acid, polyesters obtained by reacting ethylene glycol and sebacic acid, and polyesters obtained by reacting 1,4-butanediol and succinic acid. Among them, the polyester obtained by reacting 1,4-cyclohexanedimethanol and adipic acid is most preferable.

The amount of the above compound added is 1 to 30% by mass, preferably 2 to 20% by mass, and more preferably 3 to 15% by mass, based on the whole toner.

Next, the image forming apparatus used in the image forming method using the two-component developer of the present invention will be described.

FIG. 5 is a sectional view showing an example of the image forming apparatus of the present invention. Reference numeral 104 denotes a photosensitive drum which is a member to be charged, which is formed by forming an organic photoconductor (OPC) which is a photosensitive layer on an outer peripheral surface of a drum base made of aluminum, and rotates at a predetermined speed in an arrow direction. .

In FIG. 5, the semiconductor laser light source 10 is based on the information read by a document reading device (not shown).
Exposure light is emitted from 1. This is a polygon mirror 10
2, the light is distributed in the direction perpendicular to the paper surface of FIG. 5, and is irradiated onto the surface of the photoconductor through the fθ lens 103 that corrects the image distortion to form an electrostatic latent image. The photosensitive drum 104 is
It is uniformly charged in advance by the charger 105, and starts rotating clockwise in accordance with the timing of image exposure.

The electrostatic latent image on the surface of the photosensitive drum is the developing device 1.
The developed image formed and formed by 06 is transferred by the operation of the transfer device 107 to the transfer material 108 that has been conveyed at a timing. Further, the photosensitive drum 4 and the transfer material 8
Are separated by a separator (separation pole) 109, but the developed image is transferred and carried on the transfer material 8 and guided to a fixing device 110 to be fixed.

The untransferred toner and the like remaining on the surface of the photoconductor are
It is cleaned by the cleaning device 111 of the cleaning blade type, the residual charge is removed by pre-charge exposure (PCL) 112, and it is uniformly charged again by the charging device 105 for the next image formation.

The exposure is preferably a digital image exposure in the present invention, but may be an analog image exposure.

The present invention can also be used in an image forming apparatus by electrophotography, particularly an apparatus for forming an electrostatic latent image on a photosensitive member by a modulated beam modulated with digital image data from a computer or the like. FIG. 7 is a schematic view showing a digital image forming apparatus applied to the toner of the present invention.

In recent years, in the field of electrophotography in which an electrostatic latent image is formed on a photoconductor and the latent image is developed to obtain a visible image, it is easy to improve the image quality, convert it, edit it, etc. Research and development of an image forming method using a digital method capable of forming an image are actively performed.

As a scanning optical system optically modulated by a digital image signal from a computer or a copy manuscript employed in this image forming method and apparatus, an acousto-optic modulator is interposed in a laser optical system, and the acousto-optic modulator is used to emit light. There is a device for modulating and a device for directly modulating the laser intensity by using a semiconductor laser. These scanning optical systems perform spot exposure on a uniformly charged photoconductor to form a dot-shaped image.

The beam emitted from the above-mentioned scanning optical system has a circular or elliptical luminance distribution which is approximate to a normal distribution with the skirt widening to the left and right. For example, in the case of a laser beam, it is usually the main component on the photoconductor. One or both of the scanning direction and the sub-scanning direction is an extremely narrow round or elliptical shape of 20 to 100 μm.

In the present invention, not only monochrome images but also
The present invention is also applied to image formation for obtaining a color image. For example, a plurality of image forming units are provided, and each image forming unit forms a visible image (toner image) of a different color to form a toner image. Image forming method.

Further, the image forming apparatus used in the present invention may have a toner recycling mechanism for recycling the untransferred toner remaining on the surface of the photoreceptor. The method for carrying out toner recycling is not particularly limited, but, for example, the toner collected in the cleaning section is mixed with a replenishment toner hopper, a developer or a replenishment toner by an intermediate chamber by a conveyor or a conveyor screw. And a method of supplying it to the developing device. A method of returning directly to the developing unit or a method of mixing and supplying the replenishment toner and the recycled toner in the intermediate chamber is preferable.

Next, referring to FIG. 6, an example of a perspective view of a toner recycling member is shown. This method is a method in which recycled toner is directly returned to the developing device.

The untransferred toner collected by the cleaning blade 63 is collected in the toner recycle pipe 64 by the carrying screw in the toner cleaning device 61,
Further, from the receiving port 65 of the recycling pipe to the developing device 56
And is used again as a developer.

FIG. 6 is also a perspective view of a process cartridge detachably mountable to the image forming apparatus of the present invention. This Figure 6
In the drawing, the photoconductor unit and the developer unit are shown separately for the sake of easy understanding of the perspective structure, but they can be detachably mounted in the image forming apparatus as a unit in which they are all integrated. In this case, the photoconductor, the developing device, the cleaning device, and the recycling member are integrated to form a process cartridge.

Further, the image forming apparatus may be configured such that a photosensitive drum and a process cartridge including at least one of a charging device, a developing device, a cleaning device, a recycling member, etc. are mounted.

In the image forming method of the present invention, the toner image formed in the developing step is fixed in the fixing step after being transferred to the transfer material as described above. A so-called contact heating method can be mentioned as a suitable fixing method used in the present invention. In particular, as the contact heating method, there are a heat pressure fixing method, a heat roll fixing method, and a pressure contact heating fixing method in which fixing is performed by a rotating pressure member including a fixedly arranged heating body.

FIG. 8 is a sectional view showing an example of a fixing device used in the image forming method using the developer of the present invention. The fixing device 110 shown in FIG.
And a pressure roller 72 that abuts against this. In FIG. 8, T is a toner image formed on the transfer paper (image forming support).

The heating roller 71 has a coating layer 82 made of a fluororesin or an elastic body formed on the surface of a cored bar 81, and contains a heating member 75 made of a linear heater.

The core metal 81 is made of metal and has an inner diameter of 10 to 70 mm. The metal forming the core metal 81 is not particularly limited, but examples thereof include metals such as iron, aluminum and copper, and alloys thereof.

The core metal 81 has a wall thickness of 0.1 to 15 mm, and is determined in consideration of a balance between a request for energy saving (thinning) and strength (depending on constituent materials). For example,
In order for the core metal made of aluminum to maintain the same strength as the core metal made of iron of 0.57 mm, it is necessary to make the wall thickness 0.8 mm.

The fluororesin forming the coating layer 82 includes PTFE (polytetrafluoroethylene) and P.
Examples thereof include FA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer).

The thickness of the coating layer 82 made of fluororesin is 1
The thickness is 0 to 500 μm, and preferably 20 to 400 μm.

The coating layer 82 made of fluororesin has a thickness of 1
When the thickness is less than 0 μm, the function as the coating layer cannot be sufficiently exhibited, and the durability as the fixing device cannot be ensured. On the other hand, there is a problem in that the surface of the coating layer having a thickness of more than 500 μm is easily scratched by paper dust, and toner or the like adheres to the scratched portion, resulting in image stain.

As the elastic body forming the coating layer 82, it is preferable to use silicone rubber or silicone sponge rubber having good heat resistance such as LTV, RTV and HTV.

Asker C, which is an elastic material constituting the coating layer 82
The hardness is less than 80 °, preferably less than 60 °.

The thickness of the coating layer 82 made of an elastic material is 0.1 to 30 mm, preferably 0.1 to 20 mm.
It is said that

Asker C, which is an elastic body forming the coating layer 82
When the hardness exceeds 80 ° and the thickness of the coating layer 82 is less than 0.1 mm, the fixing nip cannot be increased, and the effect of soft fixing (for example, smoothed interface Effect of improving color reproducibility by toner layer)
Can't exert.

As the heating member 75, a halogen heater can be preferably used. The pressure roller 72 is
A coating layer 84 made of an elastic body is formed on the surface of the cored bar 83. The elastic body forming the coating layer 84 is not particularly limited, and various soft rubbers such as urethane rubber and silicone rubber and sponge rubber can be exemplified. The silicone rubbers exemplified as the material forming the coating layer 84 and It is preferable to use silicone sponge rubber.

Asker C, which is an elastic material constituting the coating layer 84
The hardness is less than 80 °, preferably less than 70 °, and more preferably less than 60 °.

The coating layer 84 has a thickness of 0.1 to 30 m.
m, preferably 0.1 to 20 mm.

Asker C, which is an elastic material constituting the coating layer 84
If the hardness exceeds 80 ° and the thickness of the coating layer 84 is less than 0.1 mm, the fixing nip cannot be increased and the soft fixing effect cannot be exhibited.

The material constituting the cored bar 83 is not particularly limited, but a metal such as aluminum, iron or copper, or an alloy thereof can be used.

The contact load (total load) between the heating roller 71 and the pressure roller 72 is usually 40 to 350 N, preferably 50 to 300 N, and more preferably 50.
~ 250N. This contact load is applied to the heating roller 1
The strength is defined as 0 (thickness of the core metal 81), and for a heating roller having a core metal of, for example, 0.3 mm iron, it is preferably 250 N or less.

From the viewpoint of offset resistance and fixing property, the nip width is preferably 4 to 10 mm, and the surface pressure of the nip is 0.6 × 10 ⁵ Pa to 1.5.
It is preferably × 10 ⁵ Pa.

As an example of the fixing conditions by the fixing device shown in FIG. 8, the fixing temperature (surface temperature of the heating roller 71) is 150 to 210 ° C., and the fixing linear velocity is 230 to 900 m.
m / sec.

A cleaning mechanism may be added to the fixing device for use. As a cleaning method,
A method of supplying various silicone oils to the fixing film and a method of cleaning with a pad, a roller, a web impregnated with various silicone oils are used.

As the silicone oil, polydimethylsiloxane, polymethylphenylsiloxane, polydiphenylsiloxane, etc. can be used. Further, a siloxane containing fluorine can also be preferably used.

The transfer paper used in the present invention is typically plain paper, but is not particularly limited as long as it can transfer an unfixed image after development, and it is a P for OHP.
ET base and the like are also included.

[0208]

[Career manufacturing example]

(Production of ferrite core material) 18 mol% MnO, Mg
4 mol% of O and 78 mol% of Fe ₂ O ₃ were pulverized with a wet ball mill for 2 hours, mixed and dried, and then 900 ° C.
It was calcined by holding it for 2 hours and pulverized with a ball mill for 3 hours to form a slurry. A dispersant and a binder were added, the mixture was granulated with a spray dryer, dried, and then main-baked at 1200 ° C. for 3 hours to obtain ferrite core particles having a specific resistance of 4.3 × 10 ⁶ Ω · cm and 60 μm. . (Production of coating resin) First, the number of carbon atoms is 1 as a surfactant.
A copolymer of cyclohexyl methacrylate / methyl methacrylate (copolymerization ratio 5/5) was synthesized by an emulsion polymerization method using sodium benzenesulfonate having an alkyl group of 2 with a concentration of 0.3 mass% in an aqueous medium. Volume average primary particle size of 0.1 μm and weight average molecular weight (M
w) 200,000, number average molecular weight (Mn) 91,000
0, Mw / Mn = 2.2, softening point temperature (Tsp) 230
Resin fine particles having a glass transition temperature (Tg) of 110 ° C. were obtained. The resin fine particles were azeotroped with water in an emulsified state, and the residual monomer amount was 510 ppm. (Carrier Production Example 1) 100 parts by mass of ferrite core material particles and 3.89 parts by mass of the resin fine particles are charged into a high-speed agitation mixer having a stirring blade shown in FIG. The first step of resin coating was carried out using the action of dynamic impact force (first layer formation).

After cooling the resin-coated carrier in the first step,
With respect to 100 parts by mass of the ferrite core material particles in the first step,
1.67 parts by mass of the resin fine particles, titanium dioxide particles (B
ET specific surface area 90 to 140 m ² / g spindle shape) 0.5
1 part by mass is charged into a high-speed stirring mixer with stirring blades,
The second step of resin coating (second layer formation) was carried out by again stirring and mixing at 20 ° C. for 30 minutes using the action of mechanical impact force to obtain a carrier 1 in which the surface of the carrier core material particles was resin coated. . (Carrier Production Example 2) 100 parts by mass of ferrite core material particles, 3.11 parts by mass of the resin fine particles, and 0.1 parts by mass of titanium dioxide particles were charged into a high-speed stirring mixer with stirring blades shown in FIG. The first step of resin coating was carried out using the action of mechanical impact forces with stirring mixing at 120 ° C. for 30 minutes (first layer formation).

In the second step of Carrier Production Example 1, 1.33 parts by mass of resin fine particles and 0.1% by weight of titanium dioxide particles were used.
A carrier 2 in which the surface of the carrier core material was coated with resin was obtained in the same manner except that the amount was changed to 27 parts by mass. (Carrier Production Example 3) In Carrier Production Example 1, 2.72 parts by mass of the resin fine particles of the first step, 1.17 parts by mass of the resin fine particles of the second step, and 0.2 parts of titanium dioxide particles are used.
A carrier 3 having a carrier core material surface coated with a resin was obtained in the same manner except that the amount was changed to 3 parts by mass. (Carrier Production Example 4) In Carrier Production Example 1, the resin fine particles in the first step were added to 1.94 parts by mass, the resin fine particles in the second step were added to 0.83 parts by mass, and the titanium dioxide particles were added to 0.1%.
A carrier 4 in which the surface of the carrier core material was coated with a resin was obtained in the same manner except that the amount was changed to 7 parts by mass. (Carrier Comparative Example 1) 100 parts by mass of ferrite core material particles and 1.67 parts by mass of the resin fine particles are charged into a high-speed stirring mixer equipped with stirring blades, and stirred and mixed at 120 ° C. for 30 minutes to act on mechanical impact force. A resin-coated carrier comparative example 1 was obtained. (Carrier Comparative Example 2) In Carrier Production Example 2, 1.95 parts by mass of the resin fine particles in the first step, 0.59 parts by mass of the titanium dioxide particles, and 0.8% of the resin fine particles in the second step are used.
A resin-coated carrier comparative example 2 was obtained in the same manner except that the titanium dioxide particles were changed to 0.25 parts by mass in 3 parts by mass. (Comparative Carrier Example 3) In Carrier Production Example 2, 3.11 parts by mass of the resin particles in the first step, 0.62 parts by mass of the titanium dioxide particles, and 1.3 parts by weight of the resin particles in the second step were used.
A resin-coated carrier comparative example 3 was obtained in the same manner except that the titanium dioxide particles were changed to 3 parts by mass and the titanium dioxide particles were changed to 0.27 parts by mass. [Production Example of Resin Particles for Toner] (Resin Particles 1HML) (1) Preparation of Core Particles (First Stage Polymerization): 5000 m with Stirrer, Temperature Sensor, Cooling Tube, Nitrogen Introducing Device
In a separable flask of 1, the anionic surfactant C
A surfactant solution (aqueous medium) prepared by dissolving 7.08 g of ₁₀ H ₂₁ (OCH ₂ CH ₂ ) ₂ OSO ₃ Na in 3010 g of ion-exchanged water was charged, and the contents of the flask were stirred while stirring at a stirring speed of 230 rpm under a nitrogen stream. The temperature was raised to 80 ° C.

To this surfactant solution, 9.2 g of a polymerization initiator (potassium persulfate: KPS) was added 200 g of deionized water.
Was added to the solution of the initiator, and the temperature was adjusted to 75 ° C. Then, 70.1 g of styrene and 1 of n-butyl acrylate were added.
A monomer mixture liquid consisting of 9.9 g and methacrylic acid 10.9 g was added dropwise over 1 hour, and the system was heated and stirred at 75 ° C. for 2 hours to perform polymerization (first stage polymerization), A latex (dispersion of resin particles composed of a high molecular weight resin) was prepared. This is designated as "latex (1H)". (2) Formation of intermediate layer (second-stage polymerization); styrene 105.6 g, n- in a flask equipped with a stirrer.
Butyl acrylate 30.0 g, methacrylic acid 6.2
g, n-octyl-3-mercaptopropionic acid ester 5.6g in a monomer mixture liquid, the compound represented by the above formula (19) as a crystalline substance (hereinafter referred to as "exemplary compound (19)"). ) 98.0 g was added, and the mixture was heated to 90 ° C. and dissolved to prepare a monomer solution.

On the other hand, an anionic surfactant (the above formula (1
01)) 1.6 g of ion-exchanged water dissolved in 2700 ml of a surfactant solution was heated to 98 ° C., and the latex solution (1H) as a dispersion of core particles was added to the surfactant solution.
After adding 28 g of solid content, a mechanical dispersion machine with a circulation path "CLEARMIX"
(Manufactured by M Technique Co., Ltd.), a monomer solution of the exemplified compound (19) is mixed and dispersed for 8 hours to obtain a dispersion liquid (emulsion liquid) containing emulsified particles (oil droplets) having a dispersed particle diameter of 284 nm. Prepared.

Next, to this dispersion (emulsion), an initiator solution prepared by dissolving 5.1 g of a polymerization initiator (KPS) in 240 ml of ion-exchanged water and 750 ml of ion-exchanged water were added, and this system was added to 98 Polymerization (second-stage polymerization) is performed by heating and stirring at ℃ for 12 hours to obtain latex (dispersion liquid of composite resin particles having a structure in which the surface of resin particles made of high molecular weight resin is coated with intermediate molecular weight resin). Obtained. This is designated as "latex (1HM)".

When the latex (1HM) was dried and observed with a scanning electron microscope, particles (4) containing the exemplified compound (19) not surrounded by the latex as a main component were obtained.
(0 to 1000 nm) was observed. (3) Formation of outer layer (third stage polymerization): The polymerization initiator (KPS) was added to the resin particles (1HM) obtained as described above.
An initiator solution prepared by dissolving 4 g in 200 ml of ion-exchanged water was added, and under the temperature condition of 80 ° C., 300 g of styrene,
95 g of n-butyl acrylate, methacrylic acid 15.3
A monomer mixture solution consisting of 10.4 g of g, n-octyl-3-mercaptopropionic acid ester was added dropwise over 1 hour. After completion of dropping, polymerization (third stage polymerization) was carried out by heating and stirring for 2 hours, followed by cooling to 28 ° C. and latex (a central portion made of a high molecular weight resin, an intermediate layer made of an intermediate molecular weight resin, A dispersion liquid of composite resin particles having an outer layer made of a molecular weight resin and containing the exemplary compound (19) in the intermediate layer was obtained. This latex is referred to as "latex (1HML)".

The composite resin particles constituting this latex (1HML) are 138,000, 80,000 and 1
Has a peak molecular weight of 3,000, and
The weight average particle diameter of the composite resin particles was 122 nm. (Dispersion of Colorant) Anionic Surfactant (101) 5
9.0 g of ion-exchanged water was dissolved in 1600 ml with stirring, and while stirring this solution, carbon black "Regal 3
30 "(manufactured by Cabot Co.) 420.0 g is gradually added, and then dispersed using" CLEARMIX "(manufactured by M Technique Co., Ltd.) to obtain a dispersion liquid of colorant particles (hereinafter referred to as" colorant "). Dispersion 1 ”) was prepared. The particle size of the colorant particles in this colorant dispersion 1 was measured by using an electrophoretic light scattering photometer “ELS-800” (manufactured by Otsuka Electronics Co., Ltd.) and found to be 110 nm. (Coagulation / fusion) Latex 1HML 420.7 g (solid content conversion), ion-exchanged water 900 g and "colorant dispersion 1" 200 g, a reaction container equipped with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a stirring device. (Four-necked flask)
And stirred. After adjusting the temperature in the container to 30 ° C,
A 5N (N) aqueous sodium hydroxide solution was added to this solution to adjust the pH to 8 to 11.0.

Then, magnesium chloride hexahydrate 1
An aqueous solution obtained by dissolving 2.1 g in 1000 ml of ion-exchanged water was added with stirring at 30 ° C. for 10 minutes. The temperature was started after being left for 3 minutes, and this system was heated to 90 ° C. over 60 minutes. In that state, the particle size of the associated particles was measured with a “Coulter counter TA-II”, and when the number average particle size reached 4 to 7 μm, sodium chloride 4
An aqueous solution prepared by dissolving 0.2 g in 1000 ml of ion-exchanged water was added to stop the particle growth, and as the aging treatment, fusion was continued by heating and stirring at a liquid temperature of 98 ° C. for 6 hours to obtain colorant particles. Obtained. [Production of Developer] Next, 1% by mass of hydrophobic silica (number average primary particle diameter = 12 nm, hydrophobicity = 68) and hydrophobic titanium oxide (number average primary particle diameter =) are added to the colorant particles.
0.5% by mass of 20 nm, hydrophobicity = 63) was added and mixed by a Henschel mixer to obtain a toner.

Toners were respectively added to and mixed with the above-mentioned carrier production examples 1 to 4 and carrier comparison examples 1 to 3 so that the toner concentration was 6% to prepare developers. These are described in Example 1.
4 and Comparative Examples 1 to 3.

The characteristics of the obtained developer are shown in Table 1.

[0219]

[Table 1]

[0220]

[Table 2]

[Image formation] Using the developer prepared here, the actual copying was evaluated using a digital copying machine Konica 7075 manufactured by Konica Corporation. [Evaluation] Using the above copying machine, high temperature and high humidity conditions (30 ° C, 8 ° C)
Image formation (image density, image density,
Fog density and character fringe) were evaluated.

As an evaluation sample, when the amount of carrier coverage in the initial image and the actual image is 20% less than that in the initial stage (R8)
Also, evaluation was performed using the image obtained at the time of 40% wear from the initial stage (R6). The carrier coverage is measured by the dissolution method.

The image density is measured by using "RD-918" manufactured by Macbeth Co., Ltd. The image density is a density of a solid black image measured by absolute reflection density. If the density value is 1.2 or more, the result is acceptable.

⊚: 1.3 or more ∘: 1.2 to less than 1.3 ×: less than 1.2 Fog density The fog density was measured by the relative reflection density with the reflection density of the transfer paper being 0 for a solid white image. . Observe formed images one after another,
The number of image stains (fogging) was counted, and if the number was less than 0 to 10, it was judged as good.

⊚: 0 to 3 ∘: 4 to less than 10 x: 10 or more Character fringe Character images were printed, and fringes around the characters were observed with a magnifying glass. "◎" indicates that character fringes are almost undetectable
“O” indicates that there is a slight character fringe, but is not noticed unless the user looks carefully, and “x” indicates that the character fringe is easily detected.

Table 3 shows the evaluation results of the developers.

[0227]

[Table 3]

As is clear from the results in Table 3 above, by using the developers of the present invention, Examples 1 to 4, satisfactory results were obtained in terms of image density, fog, and character fringe over the entire life. Was given.

[0229]

As is clear from the results of the above embodiment,
Even when the wear of the coating layer of the carrier core material progresses, the amount of toner adhered to the transfer material does not change, and the developer of the present invention has the property of not causing fluctuation in the resistance value of the carrier,
It has made it possible to provide a developer capable of obtaining an electrophotographic image for a long period of time, which has a good image density over the entire life and has a good image quality without fog or character fringe.

[Brief description of drawings]

FIG. 1 is a side view of a high-speed stirring mixer with stirring blades, which is an example of manufacturing the carrier of the present invention.

FIG. 2 is a plan view of a stirring blade of the high-speed stirring mixer with stirring blades shown in FIG.

FIG. 3 is a side view of a stirring blade of the high-speed stirring mixer with stirring blade of FIG.

FIG. 4 is a plan view of the high speed stirring mixer with stirring blades of FIG. 1.

FIG. 5 is a cross-sectional configuration diagram showing an example of an image forming apparatus using the two-component developer of the present invention.

FIG. 6 is a perspective configuration diagram showing an example of a toner recycling member used in the image forming method of the present invention.

FIG. 7 is a schematic view showing an example of a digital image forming apparatus applied to the image forming method of the present invention.

FIG. 8 is a schematic sectional view showing an example of a fixing device used in an image forming method using a two-component developer of the present invention.

[Explanation of symbols]

10 Main body container 10a Main body container bottom 11 Main body lid 12 Raw material inlet 13 Input valve 14 filters 15 inspection port 16 thermometer 17 jacket 18 Horizontal rotating body 18a, 18b, 18c Horizontal wing body 18d Horizontal center of rotation 19 Vertical rotating body 20 Product outlet 21 discharge valve 22 motor 23 Slit air blower

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenji Yamane             2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica stock             In the company (72) Inventor Hajime Tadokoro             2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica stock             In the company F-term (reference) 2H005 AB06 BA06 BA07 BA15 CA02                       CB04 CB07 EA01 EA05

Claims (15)

[Claims] 1. A toner containing a binder resin and a colorant,
In the two-component developer having a carrier, the carrier is a carrier core material having a coating layer containing metal oxide particles, and the concentration of the metal oxide particles in the coating layer is the carrier core material. A two-component developer characterized by being the smallest at the interface with. 2. A toner containing a binder resin and a colorant,
And a two-component developer having a carrier, wherein the toner has particles formed in an aqueous medium, and the carrier has a carrier core material having a coating layer containing metal oxide particles, A two-component developer, wherein the concentration of the metal oxide particles in the coating layer is the smallest at the interface with the carrier core material. 3. A toner containing a binder resin and a colorant,
The two-component developer according to claim 1 or 2, further comprising a carrier, wherein the concentration of the metal oxide particles in the coating layer of the carrier core material has a concentration gradient, and A two-component developer characterized by being the largest. 4. A toner containing a binder resin and a colorant,
The two-component developer according to any one of claims 1 to 3, further comprising a carrier and a carrier, wherein the coating layer of the carrier core material is composed of a plurality of layers having different concentrations of metal oxide particles. A two-component developer characterized in that 5. A toner containing a binder resin and a colorant,
The two-component developer according to any one of claims 1 to 4, further comprising: and a carrier, wherein the shape of the metal oxide particles is a spindle shape. 6. A toner containing a binder resin and a colorant,
The two-component developer according to any one of claims 1 to 5, further comprising: and a carrier, wherein the coating layer of the carrier core material is made of an acrylic resin. . 7. An image forming method for visualizing an electrostatic latent image formed on a photoreceptor by using the two-component developer according to claim 1. An image forming method characterized by having the following relationship between the amount of wear of a coating layer of a carrier core material and the amount of toner adhered onto a transfer material. 0.6 <a2 / a1 <0.97 a1 = (P8-P10) / (R10-R8) a2 = (P6-P8) / (R8-R6) [wherein R10 and P10 are used for image formation] Represents the amount of the coating layer of the carrier core material and the amount of toner adhering to the transfer material in the initial stage before being removed. R8 and P8 are carrier core materials when the coating layer of the carrier core material is worn down by 20% from the initial stage. R6, P6
Represents the amount of the coating layer of the carrier core material and the toner adhesion amount when the coating layer of the carrier core material is 40% worn from the initial stage. ] 8. An image forming method for visualizing an electrostatic latent image formed on a photoconductor by using the two-component developer according to claim 1. An image forming method characterized by having the following relationship between the amount of wear of the coating layer of the carrier core material and the amount of change in the carrier resistance value. 0.6 <log | b2 / b1 | <0.97 b1 = (S10-S8) / (R10-R8) b2 = (S8-S6) / (R8-R6) [wherein R10 and S10 are image formations Represents the amount of the carrier core material coating layer and the carrier resistance value in the initial stage before being subjected to the heat treatment, and R8 and S8 are the coatings of the carrier core material when the coating layer of the carrier core material is worn down by 20% from the initial stage. The amount of the layer and the carrier resistance value are represented, and R6 and S6 represent the amount of the coating layer of the carrier core material and the carrier resistance value when the coating layer of the carrier core material is worn out by 40% from the initial stage. ] 9. An image forming method for visualizing an electrostatic latent image formed on a photoconductor by using the two-component developer according to claim 1. An image forming method characterized in that a two-component developer is recycled. 10. An image forming method for visualizing an electrostatic latent image formed on a photoconductor by using the two-component developer according to any one of claims 1 to 6. An image forming method, wherein the latent image is formed on the photoconductor by digital exposure. 11. The toner has a number average particle diameter of 3-9.
The two-component developer according to claim 1, wherein the two-component developer has a thickness of μm. 12. The two-component developer according to claim 1, wherein the toner is obtained by polymerizing at least a polymerizable monomer in an aqueous medium. 13. The two-component developer according to claim 1, wherein the toner is obtained by aggregating and fusing at least resin particles in an aqueous medium. 14. The toner is obtained by salting out / fusing resin particles and colorant particles formed through at least a step of polymerizing a polymerizable monomer. The two-component developer according to any one of 1 to 6. 15. The toner according to claim 1, wherein the toner is obtained by salting out / fusing resin particles obtained by a multi-stage polymerization method and colorant particles. The two-component developer described in.