JP2006201533A - Toner, method for manufacturing toner, developer, developing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a toner having a controlled attached state of an external additive to toner particles and controlled fluidity, not causing failure such as surface stain, and having stable charging characteristics. <P>SOLUTION: The toner for image formation has the external additive on the toner particles including at least a binder resin and a colorant. The external additive is attached to surfaces of the toner particles, heat treatment is carried out in a temperature range of 1/2Tg≤T≤Tg (where T is ≥25°C and Tg is a glass transition temperature of the toner), and the heat treatment is carried out in a toner stationary state. An attachment rate of the external additive on the toner surface is ≥80% and a loosening apparent density is 0.38-0.43. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a toner used for image formation in an electrostatic copying process such as a copying machine, a facsimile machine, a printer, and the like, and a manufacturing method thereof, and further a developer using the toner, and a development using the developer. The present invention relates to an apparatus and an image forming apparatus.

  In an image forming method such as electrophotography, electrostatic recording, and electrostatic printing, in the development process, for example, toner contained in a developer is temporarily attached to an image carrier such as a photosensitive member on which an electrostatic image is formed. Then, after the toner is transferred from the photoreceptor to a transfer medium such as transfer paper in the transfer process, the toner is fixed on the paper surface in the fixing process. The developer is classified into a one-component development method and a two-component development method, and a two-component developer composed of a magnetic carrier and a toner, and a one-component developer that does not require a magnetic carrier (magnetic toner, Non-magnetic toners are known.

As the toner used for the developer, a dry toner of a kneading and pulverizing method, which is produced by melt-kneading a toner binder such as a styrene resin and a polyester resin together with a colorant and finely pulverizing, has been used conventionally. .
In recent years, in order to achieve high-definition color image formation in response to the demand for higher image quality, the toner has been reduced in particle size and spheroidized. Many toners manufactured by granulating toner particles in a liquid, including toners produced by a dispersion polymerization method or the like, have been studied.

Conventionally, inorganic / organic fine particles have been externally added to these toners used for image formation for the purpose of imparting fluidity to supplement transportability and mixing properties and for charge control. As a method for adding inorganic fine particles or the like to a toner, a method of adhering inorganic fine particles such as silica, alumina, titanium oxide or the like together with the toner by dry mixing and stirring with a mixer or the like is common.
In particular, in order to improve fluidity, it is effective to increase the amount of fluidizing agent such as inorganic fine particles added to the toner.

For example, Patent Document 1 proposes a method of adding an external additive having a relatively small particle size. Thus, by using an external additive having a small particle size, the effect of improving fluidity can be greatly obtained.
However, such an external additive having a small particle size is immediately embedded in the toner due to stress with a member that comes into contact with the toner during use, and fluidity is impaired, so that toner replenishment property, developability, and charging property are deteriorated. There is a problem that it will.
In particular, since the toner prepared by the polymerization method as described above is spherical, it easily rolls on the image carrier, easily slips through the elastomer cleaning blade, and has a problem in that cleaning failure occurs. is there.

Therefore, as a means for solving the above problems, a method of adding external additives having different particle diameters is known.
For example, in Patent Document 2, in an electrostatic latent image developing toner obtained by mixing and adding an external additive to toner particles containing at least a colorant and a binder resin, the volume average particle size of the toner particles is 3. Toner particles having a shape factor of 100 to 130, a hydrophobic inorganic fine particle A having a number average particle size of 5 to 70 nm and a number average particle size of 80 to 800 nm and 1,000 nm or more. An electrostatic latent image developing toner containing inorganic fine particles B having a particle content of 20% by number or less is disclosed.
Thereby, it is possible to provide a toner for developing an electrostatic latent image which is a small particle size spherical toner and does not cause a cleaning failure.

  In Patent Document 3, in a negatively charged toner obtained by mixing and adding at least three kinds of external additives to negatively charged toner particles, the first additive having a number average particle diameter of 10 to 30 nm is used. It consists of inorganic fine particles, second inorganic fine particles having a number average particle diameter of 10 to 90 nm, and third inorganic fine particles having a number average particle diameter of 100 to 1000 nm, and the blow-off charge amount of the first inorganic fine particles is −2000 to − A negatively charged toner having a blowoff charge amount of 500 μC / g, a second inorganic fine particle of −300 to +50 μC / g, and a blowoff charge amount of the third inorganic fine particle of −10 to +100 μC / g, and the toner and a magnetic carrier. Negatively charged developers have been proposed.

However, as described in Patent Document 2 or 3, when an external additive having a large particle size is used or the amount of the external additive is increased, the external additive is easily released from the toner. There is. The external additive released from the surface of the toner particles causes scratches on the photoreceptor and blades, and also adheres to the image carrier such as the photoreceptor to cause filming of the external additive that becomes a starting point for fixing the toner. In addition, the carrier surface is contaminated and the charge amount rise of the toner is lowered. In addition, these external additives form aggregates and are transferred onto the recording medium, which may cause black spot image defects.
On the other hand, when the external additive is released from the surface of the toner particles in this way, the amount of the external additive attached changes and the fluidity of the toner changes. The change in fluidity also leads to a change in charging characteristics, such as rising of charging when toner is used.
Conventionally, in external additive processing at the time of toner production, due to variations in processing conditions during mixing, the adhesion rate of external additives is not stable, fluidity varies, and stable charging characteristics cannot be obtained. There was a problem.

In Patent Document 4, toner base particles containing a binder resin, a colorant and a charge control agent and a fluidizing agent as an external additive are mixed at a peripheral speed of 10 to 30 m / sec. And a method for producing a toner, characterized by being sieved with a sieve having an opening of 120 to 300 μm.
By performing the external additive treatment in this way, the external additive is firmly attached to the toner particles and the release thereof is prevented. The toner particle component can be prevented from adhering to the drum surface.

However, in order to obtain a toner in which the external additive inorganic fine particles on the surface of the toner particles can withstand stress during actual use and have life performance that is prevented from being peeled off and detached, the state after the treatment What is is important.
Japanese Patent Application Laid-Open No. 2004-228561 defines processing conditions when an external additive is applied, and does not specify processing conditions for toner after adding such an external additive.
For example, in the invention described in Patent Document 5, on the surface of the core particles made of a binder resin having a colorant, the toner processing conditions after applying such an external additive are defined. The core particle in which at least a part is fixed by heating in a hot air flow field and the inorganic fine particles are fixed has the BET specific surface area of the toner as S, the specific gravity of the toner as ρ, and the volume average particle diameter of the toner as D. , 2.0 × [6 / (ρD)] ≧ S ≧ 1.1 × [6 / (ρD)], and a method for producing the same is disclosed.
Further, Patent Document 6 includes a wax having a specific melting point, a hydrophobic silica fine powder having a specific specific surface area, and a conductive inorganic fine powder, and further includes a hydrophobic silica fine powder and / or a conductive material. A toner is disclosed in which after the treated inorganic fine powder is externally added and mixed, it is subjected to surface modification treatment with hot air.

Japanese Patent Laid-Open No. 62-182775 JP-A-10-207113 JP-A-10-010773 Japanese Patent Laid-Open No. 2002-229261 Japanese Patent Laid-Open No. 2000-330325 Japanese Unexamined Patent Publication No. 2000-66440

However, in the method described in Patent Document 5 or 6, since the processing conditions for immobilizing the externally added inorganic fine particles are not stipulated, it is possible to surely improve the variation in charge rise of the obtained toner. It is not.
Therefore, in view of the above circumstances, the present invention regulates the toner processing conditions after the external additive processing, thereby controlling the adhesion state and fluidity of the external additive with respect to the toner particles, so that there is no inconvenience such as scumming and stable. An object is to obtain a toner having charging characteristics.

The features of the present invention, which is a means for solving the above problems, are listed below.
1. The toner of the present invention is an image forming toner having an external additive in toner particles containing at least a binder resin and a colorant, and the adhesion rate of the external additive is 80% or more, and it appears loose. The toner has a density in the range of 0.38 to 0.43.
2. The toner of the present invention is 1. In the invention described in item 1, silica and / or titania is used as an external additive.
3. The toner of the present invention is 1. Or 2. In the invention described in item 3, the external additive having an adhesion rate of 80% or more is titania.
4). The toner of the present invention is 1. Or 3. In any one of the inventions, the external additive has an average particle size of 8 to 300 nm.
5. The toner of the present invention is 1. Or 4. In the invention according to any one of the above, the volume average particle diameter is 3 to 8 μm, the surface irregularity period λ and the number average particle diameter L of the external additive have a relationship of (1/2) λ> L. It is characterized by that.
6). The toner of the present invention is 1. Or 5. In the invention according to any one of the above, the shape factor SF-1 is in the range of 100 to 180.
7). The toner of the present invention is 1. Or 6. In any of the inventions, the toner particles of the toner include an inorganic filler in the vicinity of the surface.

8). The developer of the present invention is a developer for developing an electrostatic latent image formed on an image carrier. Or 7. Any of the toners described above and characterized by containing a magnetic substance.
9. The developer of the present invention is a developer for developing an electrostatic latent image formed on an image carrier. Or 7. Any of the toners described above and a magnetic carrier coated with a resin are mixed and used.

10. The developing device of the present invention is a developing device arranged to face an image carrier that carries an electrostatic latent image, and Or 9. The developer described in 1) is used.

11. In addition, the process cartridge of the present invention integrally supports an image carrier that carries an electrostatic latent image and at least a developing device that is disposed to face the image carrier that carries an electrostatic latent image. 9. a process cartridge which is detachable from the main body of the forming apparatus; The developing device described in 1) is used.

12 An image forming apparatus according to the present invention includes: an image carrier that carries an electrostatic latent image; and at least a developing device that is disposed to face the image carrier that carries an electrostatic latent image. And 10. The developing device described in 1) is used.

13. The image forming toner manufacturing method of the present invention is a method for manufacturing an image forming toner having an external additive in toner particles containing at least a binder resin and a colorant. After adhering to the surface, heat treatment is performed in a temperature range (T) of the following formula (1), and the heat treatment is performed in a toner stationary state.
1/2 Tg (° C.) ≦ T (° C.) ≦ T g (° C.) (Formula (1))
(Where T is 25 ° C. or higher, and Tg is the glass transition temperature of the toner)
14 In addition, the method for producing an image forming toner of the present invention is described in 13. In the invention described in item 1, the toner has an adhesion rate of the external additive of 80% or more and a loose apparent density in the range of 0.38 to 0.43.
15. In addition, the method for producing an image forming toner of the present invention is described in 13. Or 14. In the invention described in item 1, silica and titanium oxide are used as the external additive, and titanium oxide is surface-treated first.

  By the means for solving the above, the toner of the present invention is controlled in the adhesion rate and fluidity of the external additive to the toner, so that the rising of the charge is good and there is no problem such as scumming or toner scattering. A toner capable of obtaining a high-quality image can be provided.

In the toner of the present invention, an external additive is externally added to a toner base particle containing at least a binder resin and a colorant at an adhesion rate of 80% or more, and the loose apparent density of the toner is 0.38 to The toner for image formation is characterized by being in the range of 0.43.
Conventionally, in image forming toner manufacturing methods, external additives such as inorganic fine particles have been applied for the purpose of imparting fluidity and charge control. However, these external additives have an adhesive force. If it is weak, it is detached from the surface of the toner particles and released into the toner.
As described above, the external additive is liberated from the surface of the toner particles, thereby changing the adhesion rate of the external additive, causing a change in the fluidity of the toner, or changing the amount of the external additive as a charge control agent. Therefore, charging characteristics such as charging rise when using toner are affected.
In the conventional toner manufacturing method, since the toner processing conditions after applying the external additive vary, the adhesion state of the external additive of the toner also varies, making it difficult to obtain a stable charge rising. When the toner charge rise decreases, the obtained image has problems such as background smearing and toner scattering.
Therefore, in the method for producing an image forming toner according to the present invention, the external additive is attached to the surface of the toner particles in the external additive processing step on the toner base particles, and then 1/2 Tg (° C.) ≦ T (° C.). ≦ Tg (° C.), preferably 2/3 Tg (° C.) ≦ T (° C.) ≦ 9/10 Tg (° C.) (where T is 25 ° C. or more and Tg is the glass transition temperature of the toner) Further, the heat treatment is performed in a toner stationary state.
In this way, by uniformly defining the processing conditions of the toner after the external additive treatment, the adhesion state of the external additive is controlled in the toner of the present invention, and the adhesion rate can be 80% or more.

(Loose apparent density)
In the toner of the present invention, the fluidity is controlled by performing the toner treatment after applying the external additive under a certain condition and controlling the adhesion rate of the external additive within the above range.
Specifically, the toner of the present invention is a toner having a loose apparent density in the range of 0.38 to 0.43. The loose apparent density is a density in a state in which the toner is sieved and the sieve is removed, and represents the fluidity of the toner. In the present invention, 10 g of toner is placed in a 50 ml graduated cylinder, covered and shaken 50 times, the cover is opened, the scale is read after standing for 10 minutes, and the ratio to the measured amount of toner is measured as a loose apparent density. Value.
Note that the loose apparent density may not be measured under the above conditions as long as it is obtained by the same principle.

(External additive)
As the external additive used in the toner of the present invention, inorganic fine particles such as metal oxide, metal carbide, metal nitride, and metal carbonate can be used. Specifically, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide Cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride and the like.
Furthermore, organic fine particles can be used as the external additive. Specifically, polymer-based fine particles, such as polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, and dispersion polymerization, methacrylic acid ester and acrylic acid ester copolymer, polycondensation systems such as silicone, benzoguanamine, and nylon, heat Polymer particles made of a curable resin may be used.

As an external additive used for the image forming toner of the present invention, it is preferable to use silica and titanium oxide, and it is particularly preferable to surface-treat titanium oxide first.
When two or more kinds of fine particles to be applied on the toner surface are used as external additives, titanium oxide is preferentially applied to the toner surface by first treating the surface with titanium oxide, and the adhesion rate is 80% or more. The external additive to be used can be titania. Since titania is surely applied onto the toner surface, a more preferable effect can be obtained with respect to charge rising.

(Average particle size)
The volume average particle size of the external additive used in the present invention is preferably 8 to 300 nm. When the volume average particle diameter of the external additive is less than 8 nm, the toner is subjected to mechanical stress during use in the developing device, and the external additive is easily embedded in the toner. If the volume average particle size of the external additive exceeds 300 nm, it tends to be detached from the toner surface during use in the developing device. As described above, the change in the adhesion state of the inorganic fine particles A on the surface of the toner base particles also leads to a change in the charging characteristics of the toner, leading to a decrease in the charge amount and a spread in the charge amount distribution. This may cause abnormal images such as Therefore, the volume average particle diameter of the inorganic fine particles A is preferably 8 to 300 nm.
In addition, since the toner surface to which the inorganic fine particles A having the above-mentioned size are attached has irregularities, the blade cleaning property of the toner can be improved.

  The volume average particle diameter of the inorganic fine particles is selected so that the particle diameter standard is volume, and the value of the arithmetic average value corresponds to the volume average particle diameter of the present invention. If particles larger than the main peak are observed, further ultrasonic dispersion is repeated, and the coefficient of variation and volume average particle size are constant (the difference from the previous measurement is within 5% of the previous measurement). ) Repeat the measurement until

(Shape factor SF-1)
The value of the shape factor SF-1 of the toner of the present invention is preferably 100 to 180. FIG. 1 is a diagram schematically showing the shape of the toner in order to explain the shape factor SF-1. The shape factor SF-1 indicates the ratio of the roundness of the particle shape, and is expressed by the square of the maximum length MXLNG of the shape formed by projecting the toner on a two-dimensional plane represented by the following formula (3). Divide by AREA and multiply by 100π / 4. The smaller the value of SF-1 is, the closer to 100, the closer the particle is to a true sphere.
SF-1 = {(MXLNG) ² / AREA} × (100π / 4) (3)
Since the toner of the present invention has a value of SF-1 in the range of 100 to 180 and its shape is almost spherical, the contact between the toner and the toner or the toner and the image carrier becomes a point contact. The adsorbing force between the toners is weakened, so that the fluidity is increased, and the adhesion between the toner and the image carrier is also weakened, and the transfer rate is increased. The dot reproducibility is also improved. On the other hand, when the toner shape factor SF-1 is large to some extent, the cleaning margin increases, and there is no problem such as defective cleaning. Therefore, from the balance between the two, it is preferable that the shape factor SF-1 is in the range of 100 to 180 as a range in which the image quality is not deteriorated.
Specifically, the shape factor is measured by taking a picture of the inorganic fine particles A with a scanning electron microscope (S-800: manufactured by Hitachi, Ltd.) and introducing it into an image analyzer (LUSEX 3: manufactured by Nireco) for analysis. And calculated. The measurement magnification is 100,000 times.

(Relationship between external additives and toner)
Further, the toner of the present invention has a volume average particle diameter of 3 to 8 μm, and furthermore, the irregularity period λ of the surface and the number average particle diameter L of the external additive applied to the surface are (1/2). ) Λ> L. Note that the period λ used here is a value as an average value of the distance between the top of the convex portion of the toner concave and convex portion and the bottom surface of the concave portion.
As described above, the toner according to the present invention has a shape in which the concave portion of the surface has a depth sufficient to hold the external additive particles, so that the external additive particles are stably attached to the toner surface. Can be attached.

(Inorganic filler near the surface)
The toner of the present invention includes an inorganic filler, and this inorganic filler forms a filler layer near the surface of the toner base particles.
By forming the filler layer in the vicinity of the surface, the toner of the present invention forms an appropriate uneven shape on the particle surface, so that the depth of the recess and the particle size of the external additive particles have the relationship described above. It can be made to have a toner. Thereby, the external additive inorganic fine particles can be stably attached to the surface irregularities.

The filler is not particularly limited as long as it is an inorganic or organic particulate substance that does not dissolve in a solvent. In the present invention, it is preferable to use an inorganic filler as the filler. Of these, metal oxides are preferable, and silica, alumina, and titania are more preferable. Among these, silica is particularly preferable, and it is preferable to use it in the form of an organosol. In order to obtain an organosol of silica, for example, a silica hydrogel dispersion synthesized by a wet method (hydrothermal synthesis method, sol-gel method, etc.) is hydrophobized with a surface treatment agent, and water is treated with methyl ethyl ketone, The method of substituting with organic solvents, such as ethyl acetate, is mentioned.
Moreover, a filler may be used independently or may use 2 or more types according to the objective. As the filler, it is also possible to use a colorant, wax, charge control agent or the like generally used for toner.

The method for dispersing the filler is not particularly limited, and a known method can be applied. For example, the following dispersion method can be used.
(1) A method of obtaining a master batch in which a binder resin and a filler are melt-kneaded by a kneader in the presence of a solvent and / or a dispersing agent as necessary, and the filler is dispersed in the binder resin.
(2) A method in which a filler is dissolved or suspended in a solvent together with a binder resin as required, and then mechanically wet pulverized or crushed by a disperser.
(3) A method of adding and mixing fillers synthesized in a solvent.
(4) A method in which a filler dispersed in water is wet-treated by adding a treating agent, and then an organosol substituted with a solvent is added and mixed.
Among these, from the viewpoint of dispersion stability, a method in which a filler dispersed in water is wet-treated by adding a treating agent, and then a solvent-substituted organosol is added and mixed is preferable. Solvent-substituted organosols include metal oxide hydrogels synthesized by hydrothermal synthesis, sol-gel methods, etc., and dispersions of organic fine particles obtained by emulsion polymerization, seed polymerization, suspension polymerization, etc. Examples thereof include a method of hydrophobizing with the surface treatment agent and replacing water with a solvent (preferably, methyl ethyl ketone, ethyl acetate, etc.). As the method for producing the organosol, for example, the method described in JP-A No. 11-43319 can be suitably used. For example).

Although the filler layer can be observed with a transmission electron microscope (TEM), the outermost surface of the toner base particles is not covered with the filler layer, but the filler is included and the filler layer is formed along the surface shape. It is preferable. The inclusion is a state in which a filler is present inside the outermost surface of the toner base particles. When the filler is exposed to the outside of the toner base particles or adsorbed on the surface of the toner particles and covers the surface of the toner particles, the filler characteristics are dominant as the toner surface and bulk characteristics, The properties of the binder resin for toner are hardly expressed. On the contrary, when the filler is included, the characteristics of the binder resin are easily expressed. As a result, the low-temperature fixability is improved, and when the wax is contained, the wax is likely to ooze out during the heat fixing, so that the hot offset resistance is improved.
The filler layer is preferably formed along the surface shape (unevenness) of the toner base particles, but it is not necessary to use the entire vicinity of the toner surface as the filler layer.

Further, the thickness of the filler layer formed in the vicinity of the surface of the toner base particles of the present invention can be measured by image analysis of an image of a resin particle cross section by a transmission electron microscope (TEM).
That is, the toner is dispersed in a sucrose saturated solution (67% by mass solution) (hereinafter, “%” means “% by mass unless otherwise specified”), frozen at −100 ° C., and then meat on a cryomicrotome. After slicing to a thickness of about 1000 angstroms and staining the filler with ruthenium tetroxide, the resin particle cross section was photographed with a transmission electron microscope at a magnification of 10000 times, and an image analysis apparatus [for example, Nexus NEW CUBE ver. 2.5 (manufactured by NEXUS Co., etc.)], the area of the filler is 50% in the area where the thickness is a constant distance from the surface of the toner particle in the vertical direction inside the toner in the cross section where the cross sectional area is maximum. The maximum distance occupying the above is taken as the thickness of the filler layer. The measured value is an average value obtained by calculating each value for 10 randomly selected toner particles.

The thickness of the filler layer is usually 0.005 μm to 0.5 μm, preferably 0.01 μm to 0 μm.
. The thickness is 2 μm, more preferably 0.02 μm to 0.1 μm.
In order to form such a filler layer, a toner material liquid in which at least a binder resin and a filler are dispersed and / or dissolved in an organic solvent is dispersed in an aqueous medium, and the obtained droplets are formed as solid particles. It can be preferably formed by producing toner base particles by a process such as none, removal of solvent and water (hereinafter referred to as “solvent etc.”) and drying.
The irregular shape on the surface of the toner base particles is a step of removing the solvent and the like. In the process of volume shrinkage of the toner base particles, the surface area reduction rate is significantly slower than the volume shrinkage rate because the filler layer is formed. This is considered to be formed because the surface of the base particle is moderately elastic and the viscosity of the particle surface becomes higher than the inside of the particle.
When the thickness of the outer shell layer of the filler is within the above range, the difference in viscosity between the toner base particle surface and the inside of the particle becomes large, and irregularities are more easily developed on the particle surface.

<Description of filler>
The volume average particle diameter of the primary particles of the filler is preferably 0.001 to 0.5 μm, more preferably 0.001 to 0.1 μm, and particularly preferably 0.002 to 0.05 μm.
The volume average particle size of the filler is preferably measured using a laser particle size distribution measuring device when the particle size is 0.1 μm or more, and is preferably calculated from the BET specific surface area and the true specific gravity when the particle size is 0.1 μm or less. The BET specific surface area can be measured by using an apparatus based on a normal nitrogen adsorption method, and for example, trade name: QUANTTASORB (manufactured by QUANTACHROME) can be used. By dividing the reciprocal of the BET specific surface area of the filler by the true specific gravity of the filler, the primary particle diameter of the filler can be measured.

The filler content in the toner base particles is 0.01 to 100 parts by weight of the toner resin component.
20 wt% is preferable, more preferably 0.1 to 15 wt%, still more preferably 1
-10 wt%, particularly preferably 2-7 wt%.

The higher the aspect ratio of the filler, the higher the effect of forming irregularities on the surface of the toner base particles. Accordingly, the higher the aspect ratio of the filler, the more uneven the surface of the toner particles can be formed with a low addition amount.

  Further, the toner of the present invention comprises a toner material solution obtained by dissolving or dispersing at least a polymer having a site capable of reacting with a compound having an active hydrogen group, a polyester, a colorant, and a release agent in an organic solvent. Obtained by crosslinking and / or elongation reaction in an aqueous medium. Hereinafter, the constituent material and the manufacturing method of the toner will be described.

(Modified polyester)
The toner according to the present invention contains a modified polyester (i) as a binder resin. The modified polyester (i) refers to a state in which a bonding group other than an ester bond is present in the polyester resin, or resin components having different configurations are bonded to the polyester resin by a covalent bond, an ionic bond, or the like. Specifically, the polyester terminal is modified by introducing a functional group such as a carboxylic acid group or an isocyanate group that reacts with a hydroxyl group into the polyester terminal and further reacting with an active hydrogen-containing compound.

  Examples of the modified polyester (i) include urea-modified polyester obtained by a reaction between a polyester prepolymer (A) having an isocyanate group and amines (B). As the polyester prepolymer (A) having an isocyanate group, a polyester having a polycondensate of a polyhydric alcohol (PO) and a polyvalent carboxylic acid (PC) and having an active hydrogen group is further added to a polyvalent isocyanate compound (PIC). And those reacted with. Examples of the active hydrogen group possessed by the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, and the like. Among these, an alcoholic hydroxyl group is preferable.

The urea-modified polyester is produced as follows.
Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO). (DIO) alone or a mixture of (DIO) and a small amount of (TO) preferable. Examples of the dihydric alcohol (DIO) include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide bisphenol (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. The trihydric or higher polyhydric alcohol (TO) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

Examples of the polyvalent carboxylic acid (PC) include divalent carboxylic acid (DIC) and trivalent or higher polyvalent carboxylic acid (TC). (DIC) alone and (DIC) with a small amount of (TC) Mixtures are preferred. Divalent carboxylic acids (DIC) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polyvalent carboxylic acid (TC) include aromatic polyvalent carboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polycarboxylic acid (PC), you may make it react with polyhydric alcohol (PO) using the above-mentioned acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.).
The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanates; Those blocked with caprolactam or the like; and combinations of two or more of these.
The ratio of the polyvalent isocyanate compound (PIC) is usually 5/1 to 1/1, preferably as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. When the molar ratio of [NCO] is less than 1, when a urea-modified polyester is used, the urea content in the ester is lowered and hot offset resistance is deteriorated.

The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. . If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.
The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.

Next, as amines (B) to be reacted with the polyester prepolymer (A), a divalent amine compound (B1), a trivalent or higher polyvalent amine compound (B2), an amino alcohol (B3), an amino mercaptan (B4) ), Amino acid (B5), and amino acid block of B1 to B5 (B6).
Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like. Examples of the trivalent or higher polyvalent amine compound (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of the compound (B6) obtained by blocking the amino group of B1 to B5 include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

The ratio of amines (B) is equivalent to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). Is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] is more than 2 or less than 1/2, the molecular weight of the urea-modified polyester is lowered, and the hot offset resistance is deteriorated.
The urea-modified polyester may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

The modified polyester (i) used in the present invention is produced by a one-shot method or a prepolymer method. The weight average molecular weight of the modified polyester (i) is usually 10,000 or more, preferably 20,000 to 10,000,000, more preferably 30,000 to 1,000,000. The peak molecular weight at this time is preferably 1000 to 10000. When the molecular weight is less than 1000, the elongation reaction hardly occurs, the elasticity of the toner is small, and as a result, the resistance to hot offset deteriorates. On the other hand, when it exceeds 10,000, the problem in production becomes high in the deterioration of fixability, particle formation and pulverization. The number average molecular weight of the modified polyester (i) is not particularly limited when the unmodified polyester (ii) described later is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. (I) When used alone, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, and more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color device are deteriorated.
In the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B) to obtain the modified polyester (i), a reaction terminator is used as necessary to adjust the molecular weight of the resulting urea-modified polyester. be able to. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).

(Unmodified polyester)
In the present invention, not only the modified polyester (i) is used alone, but also the unmodified polyester (ii) can be contained as a binder resin component together with the (i). By using (ii) in combination, the low-temperature fixability and the gloss when used in a full-color device are improved, which is preferable to single use. Examples of (ii) include polycondensates of polyhydric alcohol (PO) and polyvalent carboxylic acid (PC) similar to the polyester component of (i) above, and preferred ones are also the same as (i). . (Ii) is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, and may be modified with a urethane bond, for example. (I) and (ii) are preferably at least partially compatible in terms of low-temperature fixability and hot offset resistance. Therefore, the polyester component (i) and (ii) preferably have similar compositions. When (ii) is contained, the weight ratio of (i) and (ii) is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, Particularly preferred is 7/93 to 20/80. When the weight ratio of (i) is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

  The peak molecular weight of (ii) is usually 1000 to 10000, preferably 2000 to 8000, and more preferably 2000 to 5000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate. The hydroxyl value of (ii) is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. If it is less than 5, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. The acid value of (ii) is preferably 1 to 5, more preferably 2 to 4. Since a high acid value wax is used as the wax, the low acid value binder leads to electrification and high volume resistance, so that it is easy to match the toner used for the two-component developer.

  The glass transition point (Tg) of the binder resin is usually 35 to 70 ° C, preferably 55 to 65 ° C. If it is less than 35 ° C., the heat resistant storage stability of the toner is deteriorated, and if it exceeds 70 ° C., the low-temperature fixability is insufficient. Since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the toner of the present invention tends to have good heat storage stability even when the glass transition point is low, as compared with known polyester-based toners. Show.

(Coloring agent)
As the colorant, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher , Yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sayred, Parachlor Ortonito Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmin Min BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R , Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thio Indigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Lid Russian nin green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

  The colorant can also be used as a master batch combined with a resin. As the binder resin to be kneaded together with the production of the master batch or the master batch, a polymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyl toluene or the like, or a copolymer of these and a vinyl compound, Polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, fat Aromatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes and the like can be mentioned, and these can be used alone or in combination.

(Charge control agent)
Known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium salts or compounds, tungsten simple substances or compounds, fluorine activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Bontron 03 of a nigrosine dye, Bontron P-51 of a quaternary ammonium salt, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex , Phenolic condensate E-89 (above, Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSY VP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit) Manufactured), copper phthalocyanine, perylene, quinacridone, azo series Fee, a sulfonic acid group, a carboxyl group, and polymer compounds having a functional group such as quaternary ammonium salts. Of these, substances that control the negative polarity of the toner are particularly preferably used.
The amount of the charge control agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the flowability of the developer is lowered, and the image density is lowered. Invite.

(Release agent)
As a release agent, a low melting point wax having a melting point of 50 to 120 ° C. works more effectively as a release agent in the dispersion with the binder resin between the fixing roller and the toner interface. The effect on high temperature offset is exhibited without applying a release agent such as oil. Examples of such a wax component include the following. Examples of waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax, and rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as ozokerite and cercin, and paraffin, microcrystalline, And petroleum waxes such as petrolatum. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, and synthetic waxes such as esters, ketones, and ethers can be used. Furthermore, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbon, and low molecular weight crystalline polymer resin, poly-n-stearyl methacrylate, poly-n- A crystalline polymer having a long alkyl group in the side chain such as a homopolymer or copolymer of polyacrylate such as lauryl methacrylate (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.) can also be used. .
The charge control agent and the release agent can be melt-kneaded together with the master batch and the binder resin, and of course, they may be added when dissolved and dispersed in the organic solvent.

Next, a toner manufacturing method will be described. Here, although a preferable manufacturing method is shown, it is not limited to this.
(Toner production method)
1) A toner material solution is prepared by dispersing a colorant, unmodified polyester, a polyester prepolymer having an isocyanate group, and a release agent in an organic solvent.
The organic solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal after toner base particle formation. Specifically, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, Methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferable. The usage-amount of an organic solvent is 0-300 weight part normally with respect to 100 weight part of polyester prepolymers, Preferably it is 0-100 weight part, More preferably, it is 25-70 weight part.

2) The toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and resin fine particles.
The aqueous medium may be water alone or an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.). It may be included.
The amount of the aqueous medium used relative to 100 parts by weight of the toner material liquid is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of the toner material liquid is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 20000 parts by weight, it is not economical.

Further, in order to improve the dispersion in the aqueous medium, a dispersant such as a surfactant and resin fine particles is appropriately added.
As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride, fatty acid amide derivative, polyhydric alcohol Nonionic surfactants such as derivatives, for example, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine And the like.

Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- ( 2-Hydroxyethyl) Perful Olooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Can be mentioned.
Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

  Moreover, as the cationic surfactant, aliphatic quaternary ammonium such as aliphatic primary, secondary or secondary amic acid, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt which has a right fluoroalkyl group is used. Salt, benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (Asahi Glass Co., Ltd.), Florard FC-135 (Sumitomo 3M Co., Ltd.), Unidyne DS-202 (Daikin Industries) Smoke), Megafac F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products), Footage F-300 (Neos), and the like.

As the resin fine particles, any resin can be used as long as it can form an aqueous dispersion, and it may be a thermoplastic resin or a thermosetting resin. Examples thereof include vinyl resins, polyurethane resins, epoxy resins, polyester resins, polyamide resins, polyimide resins, silicon resins, phenol resins, melamine resins, urea resins, aniline resins, ionomer resins, and polycarbonate resins. As the resin, two or more of the above resins may be used in combination.
Of these, vinyl resins, polyurethane resins, epoxy resins, polyester resins, and combinations thereof are preferred because an aqueous dispersion of fine spherical resin particles is easily obtained. For example, vinyl resins are polymers obtained by homopolymerization or copolymerization of vinyl monomers, such as styrene- (meth) acrylic acid ester copolymers, styrene-butadiene copolymers, (meth) acrylic acid-acrylic acid esters. Examples thereof include resins such as a polymer, a styrene-acrylonitrile copolymer, a styrene-maleic anhydride copolymer, and a styrene- (meth) acrylic acid copolymer. The average particle size of the resin fine particles is 5 to 200 nm, preferably 20 to 300 nm. In addition, inorganic compound dispersants such as tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite can also be used.

  As a dispersant that can be used in combination with the above resin fine particles and inorganic compound dispersant, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as acrylic acid-β-hydroxyethyl, methacrylic acid-β-hydroxyethyl, acrylic acid-β-hydroxypropyl, methacrylic acid-β-hydroxypropyl, acrylic acid-γ-hydroxypropyl, methacrylic acid-γ-hydroxy Propyl, acrylic acid-3-chloro-2-hydroxypropyl, methacrylic acid-3-chloro-2-hydroxypropyl, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate Luric acid esters, N-methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or compounds containing vinyl alcohol and a carboxyl group Esters such as vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl Nitrogen compounds such as imidazole and ethyleneimine, or homopolymers or copolymers such as those having a heterocyclic ring thereof, polyoxyethylene, poly Xoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxy Polyoxyethylenes such as ethylene nonylphenyl ester, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

  The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. Among these, a high-speed shearing type is preferable in order to make the particle size of the dispersion 2 to 20 μm. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C.

3) At the same time as the preparation of the emulsion, the amines (B) are added to cause a reaction with the polyester prepolymer (A) having an isocyanate group.
This reaction involves molecular chain crosslinking and / or elongation. The reaction time is selected depending on the reactivity between the isocyanate group structure of the polyester prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

4) After completion of the reaction, the organic solvent is removed from the emulsified dispersion (reactant), washed and dried to obtain toner base particles.
In order to remove the organic solvent, the temperature of the entire system is gradually raised in a laminar stirring state, and after giving strong stirring in a certain temperature range, the solvent base is removed to produce spindle-shaped toner base particles. . Further, when an acid such as calcium phosphate salt or an alkali-soluble material is used as the dispersion stabilizer, the calcium phosphate salt is dissolved from the toner base particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. Remove. It can also be removed by operations such as enzymatic degradation.

5) A charge control agent is injected into the toner base particles obtained above, and then inorganic fine particles such as silica fine particles and titanium oxide fine particles are externally added to obtain a toner.
The injection of the charge control agent and the external addition of the inorganic fine particles are performed by a known method using a mixer or the like.
In the toner of the present invention, after the external additive is attached to the surface of the toner particles, the toner is allowed to stand in a state of 1/2 Tg (° C.) ≦ T (° C.) ≦ T g (° C.) (where T is 25). The heat treatment is performed in a temperature range (T) of T ° C. or higher, and Tg is the glass transition temperature of the toner.
By storing the toner after the external additive treatment under a fixed condition as described above, the adhesion state of the external additive can be controlled, and the obtained toner has an adhesion ratio of the external additive of 80. %, And the loose apparent density can be in the range of 0.38 to 0.43.
In addition, it is preferable to use silica and titanium oxide as the external additive, and it is preferable to surface-treat titanium oxide first.
By the above manufacturing method, a toner having a small particle size and a sharp particle size distribution can be easily obtained. Furthermore, by giving strong agitation in the process of removing the organic solvent, the shape between the true spherical shape and the rugby ball shape can be controlled, and the surface morphology is also controlled between the smooth shape and the umeboshi shape. be able to.

When the toner produced as described above is used for a two-component developer, it may be used by mixing with a magnetic carrier. As the magnetic carrier, a divalent metal such as iron, magnetite, Mn, Zn, or Cu is used. a ferrite containing, weight average particle diameter _D 4 20 to 100 [mu] m is preferred. When the average particle size is less than 20 μm, carrier adhesion is likely to occur on the photoreceptor 1 during development. Cheap. In addition, Cu ferrite containing Zn is preferable because of high saturation magnetization, but can be appropriately selected according to the process of the image forming apparatus. The resin for coating the magnetic carrier is not particularly limited, and examples thereof include silicone resin, styrene-acrylic resin, fluorine-containing resin, and olefin resin. In the manufacturing method, the coating resin may be dissolved in a solvent, sprayed into a fluidized bed and coated on the core, or the resin particles are electrostatically attached to the core particles and then thermally melted for coating. It may be a thing. The resin to be coated has a thickness of 0.05 to 10 μm, preferably 0.3 to 4 μm.
It can also be used as a one-component magnetic toner that does not use a magnetic carrier, or as a non-magnetic toner.
The toner of the present invention is preferably used as a color toner. It is excellent in reproducibility of fine lines and fine dots, is excellent in toner granularity, and is excellent in reproducibility of intermediate colors, so that it is more suitable for use as a color toner for forming a color image.

(Image forming device)
An image forming apparatus using the image forming toner of the present invention as a developer will be described.
FIG. 2 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present invention. In the figure, reference numeral 100 is a copying apparatus main body, 200 is a paper feed table on which the copying apparatus is placed, 300 is a scanner mounted on the copying apparatus main body 100, and 400 is an automatic document feeder (ADF) mounted thereon.
The copying apparatus main body 100 has a tandem type in which four image forming units 18 each having various units for performing an electrophotographic process such as charging, developing, and cleaning are arranged in parallel around a photosensitive member 40 as a latent image carrier. An image forming apparatus 20 is provided. Above the tandem type image forming apparatus 20, there is provided an exposure apparatus 21 that exposes the photoreceptor 40 with laser light based on image information to form a latent image. Further, an intermediate transfer belt 10 made of an endless belt member is provided at a position facing each photoreceptor 40 of the tandem type image forming apparatus 20. A primary transfer unit 62 for transferring the toner images of the respective colors formed on the photoconductor 40 to the intermediate transfer belt 10 is disposed at a position facing the photoconductor 40 via the intermediate transfer belt 10.
A secondary transfer device 22 that collectively transfers the toner images superimposed on the intermediate transfer belt 10 onto transfer paper conveyed from the paper feed table 200 is disposed below the intermediate transfer belt 10. The secondary transfer device 22 is configured by spanning a secondary transfer belt 24 that is an endless belt between two rollers 23, and is disposed by pressing against the support roller 16 via the intermediate transfer belt 10. The toner image on 10 is transferred onto a transfer sheet. A fixing device 25 for fixing the image on the transfer paper is provided beside the secondary transfer device 22. The fixing device 25 is configured by pressing a pressure roller 27 against a fixing belt 26 that is an endless belt.
The secondary transfer device 22 described above also has a sheet transport function for transporting the transfer paper after image transfer to the fixing device 25. Of course, a transfer roller or a non-contact charger may be arranged as the secondary transfer device 22, and in such a case, it is difficult to provide this sheet conveyance function together.
In the illustrated example, a reversing device 28 for reversing the transfer paper so as to record images on both sides of the transfer paper is provided below the secondary transfer device 22 and the fixing device 25 in parallel with the tandem image forming device 20 described above. .

  The developing device 4 of the image forming unit 18 uses a developer containing the above toner. In the developing device 4, the developer carrying member carries and conveys the developer, and an alternating electric field is applied at a position facing the photoconductor 40 to develop the latent image on the photoconductor 40. By applying the alternating electric field, the developer is activated, the charge amount distribution of the toner can be narrowed, and the developability can be improved.

  Further, the developing device 4 can be a process cartridge that is integrally supported together with the photoreceptor 40 and is detachably formed on the main body of the image forming apparatus. In addition, the process cartridge may include a charging unit and a cleaning unit.

The operation of the image forming apparatus is as follows.
First, a document is set on the document table 30 of the automatic document feeder 400, or the automatic document feeder 400 is opened and a document is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed. Hold it down.
When a start switch (not shown) is pressed, when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the document is set on the other contact glass 32. At that time, the scanner 300 is immediately driven to travel the first traveling body 33 and the second traveling body 34. Then, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface toward the second traveling body 34 and reflects by the mirror of the second traveling body 34 and passes through the imaging lens 35. The document is placed in the reading sensor 36 and the original content is read.

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

On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 42 of the paper feed table 200 is selectively rotated, and the sheet is fed out from one of the paper feed cassettes 44 provided in multiple stages in the paper bank 43, and the separation roller 45. Then, the sheets are separated one by one into the paper feed path 46, transported by the transport roller 47, guided to the paper feed path 48 in the copying machine main body 100, and abutted against the registration roller 49 and stopped.
Alternatively, the sheet feed roller 50 is rotated to feed out the sheets on the manual feed tray 51, separated one by one by the separation roller 52, put into the manual feed path 53, and abutted against the registration roller 49 and stopped.
Then, the registration roller 49 is rotated in synchronization with the composite color image on the intermediate transfer belt 10, the sheet is fed between the intermediate transfer belt 10 and the secondary transfer device 22, and transferred by the secondary transfer device 22. A color image is recorded on the sheet.

The image-transferred sheet is conveyed by the secondary transfer device 22 and sent to the fixing device 25. The fixing device 25 applies heat and pressure to fix the transferred image, and then the switching roller 55 is used to switch the discharge image. The paper is discharged at 56 and stacked on the paper discharge tray 57. Alternatively, it is switched by the switching claw 55 and put into the sheet reversing device 28, where it is reversed and guided again to the transfer position, and the image is recorded also on the back surface, and then discharged onto the discharge tray 57 by the discharge roller 56.
On the other hand, the intermediate transfer belt 10 after image transfer is removed by the intermediate transfer belt cleaning device 17 to remove residual toner remaining on the intermediate transfer belt 10 after image transfer, and is prepared for re-image formation by the tandem image forming apparatus 20.

EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited thereto.
Hereinafter, “part” means part by weight, and “%” means weight%.

(Manufacture of toner)
[Production Example 1]
~ Example of production of inorganic fine particles ~
Blowing liquid SiCl ₄ ingredients core at a flow rate of Ar gas as a carrier gas using a liquid material supply system 300 SCCM (min standard volume flow (CC)), the SiCl ₄ vapor flow rate 250 SCCM, _{H 2} gas 20 SLM (per Minute standard volume flow rate (L)) and O ₂ gas 20SLM were sent to a core burner for flame hydrolysis and fusion to produce SiO ₂ fine particles. The fine particles were grown to a predetermined primary particle size, and the obtained fine particles were hydrophobized with hexamethyldisilazane to obtain [Inorganic fine particles 1] having an average primary particle size of 5 nm.

[Production Example 2]
~ Synthesis of organic fine particle emulsion ~
In a reaction vessel in which a stir bar and a thermometer were set, 683 parts of water, 11 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30, manufactured by Sanyo Chemical Industries), 80 parts of styrene, 83 parts of methacrylic acid, When 110 parts of butyl acrylate, 12 parts of butyl thioglycolate, and 1 part of ammonium persulfate were added and stirred for 15 minutes at 400 rpm, a white emulsion was obtained. The system was heated to raise the temperature in the system to 75 ° C. and reacted for 5 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours, and an aqueous vinyl resin (a copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt). A dispersion was obtained. This is designated as [fine particle dispersion 1]. The volume average particle diameter of the [fine particle dispersion 1] measured by a laser diffraction particle size distribution analyzer (LA-920, manufactured by Shimadzu Corp.) was 120 nm. A portion of [Fine Particle Dispersion 1] was dried to isolate the resin component. The Tg of the resin was 42 ° C., and the weight average molecular weight was 30,000.

[Production Example 3]
~ Preparation of aqueous phase ~
990 parts of water, 65 parts of [fine particle dispersion 1], 37 parts of a 48.5% aqueous solution of sodium dodecyldiphenyl ether disulfonate (ELEMINOL MON-7, Sanyo Chemical Industries) and 90 parts of ethyl acetate were mixed and stirred to give a milky white color Obtained liquid. This is designated as [Aqueous Phase 1].

[Production Example 4]
~ Synthesis of low molecular weight polyester ~
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen inlet tube, 229 parts of bisphenol A ethylene oxide 2-mole adduct, 529 parts of bisphenol A propylene oxide 3-mole adduct, 208 parts terephthalic acid, 46 parts adipic acid and dibutyl Add 2 parts of tin oxide, react for 8 hours at 230 ° C. under normal pressure, and further react for 5 hours under reduced pressure of 10-15 mmHg, then put 44 parts of trimellitic anhydride into the reaction vessel, and at 180 ° C. under normal pressure. The mixture was reacted for 2 hours to obtain [Low molecular weight polyester 1]. [Low molecular polyester 1] had a number average molecular weight of 2500, a weight average molecular weight of 6700, a Tg of 43 ° C., and an acid value of 25.

[Production Example 5]
~ Synthesis of intermediate polyester ~
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, trimellitic anhydride 22 And 2 parts of dibutyltin oxide were added, reacted at 230 ° C. for 8 hours at normal pressure, and further reacted for 5 hours at a reduced pressure of 10 to 15 mmHg to obtain [Intermediate Polyester 1]. [Intermediate Polyester 1] had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, Tg of 55 ° C., an acid value of 0.5, and a hydroxyl value of 51.

[Production Example 6]
-Synthesis of a modified polyester resin (referred to as prepolymer 1) capable of reacting with a compound having at least an active hydrogen group-
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 410 parts of the above [intermediate polyester 1], 125 parts of isophorone diisocyanate, and 500 parts of ethyl acetate were added and reacted at 100 ° C. for 5 hours. ] Was obtained. The average number of isocyanate groups contained per molecule of [Prepolymer 1] was 2.15.

[Production Example 7]
~ Synthesis of ketimine ~
In a reaction vessel equipped with a stir bar and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain [ketimine compound 1]. The amine value of [ketimine compound 1] was 418.

[Production Example 8]
~ Master batch synthesis ~
1200 parts water, 40 parts carbon black (manufactured by Cabot, Regal 400R), 60 parts polyester resin (manufactured by Sanyo Kasei, RS801), 30 parts water, and mixed with a Henschel mixer (manufactured by Mitsui Mining) The mixture was kneaded at 150 ° C. for 30 minutes using two rolls, rolled and cooled, and pulverized with a pulverizer to obtain [Masterbatch 1].

[Production Example 9]
-Production of toner composition containing oil phase, that is, inorganic fine particles-
In a container equipped with a stir bar and a thermometer, 400 parts of [Low molecular weight polyester 1], 110 parts of carnauba wax and 947 parts of ethyl acetate were charged, heated to 80 ° C. with stirring, and maintained at 80 ° C. for 5 hours. Thereafter, it was cooled to 30 ° C. at 1 hour. Next, 500 parts of [Masterbatch 1] and 500 parts of ethyl acetate were placed in a container and mixed for 1 hour to obtain [Raw material solution 1].
[Raw material solution 1] 1324 parts are transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), a liquid feed speed of 1 kg / hr, a disk peripheral speed of 6 m / sec, and 0.5 mm zirconia beads are 80% by volume. The wax was dispersed under the conditions of filling and 3 passes. Next, 1324 parts of a 65% ethyl acetate solution of [low molecular weight polyester 1] and 34 parts of [inorganic fine particles 1] were added, followed by one pass using a bead mill under the above conditions to obtain [Pigment / Wax Dispersion 1]. The solid content concentration of [Pigment / Wax Dispersion 1] (130 ° C., 30 minutes) was 50%.

[Production Example 10]
~ Emulsification ~
[Pigment / Wax Dispersion 1] 648 parts, [Prepolymer 1] 154 parts, [Ketimine Compound 1] 8.5 parts in a container, and TK homomixer (manufactured by Tokushu Kika) at 5,000 rpm for 1 minute After mixing, 1200 parts of [Aqueous Phase 1] was added to the container and mixed with a TK homomixer at a rotation speed of 10,000 rpm for 20 minutes to obtain [Emulsion Slurry 1].
That is, it is dispersed in an aqueous medium containing resin fine particles and an elongation reaction is performed.

[Production Example 11]
~ Solvent removal ~
[Emulsion slurry 1] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 8 hours, aging was carried out at 45 ° C. for 4 hours to obtain [Dispersion slurry 1].

[Production Example 12]
~ Washing and drying ~
[Dispersion Slurry 1] After 100 parts under reduced pressure,
(1): 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered.
(2): 1O parts of 10% sodium hydroxide aqueous solution was added to the filter cake of (1), mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure.
(3): 100 parts of 10% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(4): 300 parts of ion-exchanged water was added to the filter cake of (3), mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered twice to obtain a cake-like product. . This is designated as [Filter cake 1].
[Filter cake 1] was dried at 45 ° C. for 48 hours in a circulating dryer. Thereafter, the mixture was sieved with a 75 μm mesh to obtain toner base particles. This is designated as [toner base particle 1].

[Example 1]
[Toner base particle 1] is cut into fine powder and coarse powder, and 1.5 parts by weight of silica fine particles having an average primary particle diameter of 10 nm and 0.5 part of silica fine particles having an average primary particle diameter of 140 nm are added to 100 parts by weight of the toner base. Part by weight, titanium oxide fine particles having an average primary particle diameter of 15 nm were mixed so as to be 0.5 parts by weight, stirred and mixed with a super mixer, and then stored in a stationary state at 40 ° C. for 72 hours. Used as a photographic toner.

[Example 2]
[Toner base particle 1] is cut into fine powder and coarse powder, and 1.5 parts by weight of silica fine particles having an average primary particle diameter of 10 nm and 0.5 part of silica fine particles having an average primary particle diameter of 140 nm are added to 100 parts by weight of the toner base. Part by weight, titanium oxide fine particles with an average primary particle diameter of 15 nm were mixed so as to be 0.5 parts by weight, stirred and mixed with a Henschel mixer, and then stored in a stationary state at 40 ° C. for 72 hours. Used as a photographic toner.

[Example 3]
[Toner base particle 1] is cut into fine powder and coarse powder, and 100 parts by weight of toner base is first stirred and mixed with 0.5 parts by weight of titanium oxide fine particles having an average primary particle diameter of 15 nm by a super mixer. Thereafter, 1.5 parts by weight of silica fine particles having an average primary particle diameter of 10 nm and 0.5 parts by weight of silica fine particles having an average primary particle diameter of 140 nm are stirred and mixed, and then stored in a stationary state at 40 ° C. for 72 hours. And used as an electrophotographic toner.

[Comparative Example 1]
[Toner base particle 1] is cut into fine powder and coarse powder, and 1.5 parts by weight of silica fine particles having an average primary particle diameter of 10 nm and 0.5 part of silica fine particles having an average primary particle diameter of 140 nm are added to 100 parts by weight of the toner base. Part by weight, titanium oxide fine particles having an average primary particle diameter of 15 nm were blended so as to be 0.5 parts by weight, stirred and mixed by a super mixer, and used as an electrophotographic toner.

[Comparative Example 2]
[Toner base particle 1] is cut into fine powder and coarse powder, and 1.5 parts by weight of silica fine particles having an average primary particle diameter of 10 nm and 0.5 part of silica fine particles having an average primary particle diameter of 140 nm are added to 100 parts by weight of the toner base. Part by weight, titanium oxide fine particles having an average primary particle diameter of 15 nm were blended so as to be 1.0 part by weight, stirred and mixed with a super mixer, and used as an electrophotographic toner.

[Comparative Example 3]
[Toner base particle 1] is finely divided and coarse powder is cut, and 0.5 part by weight of silica fine particles having an average primary particle diameter of 10 nm and 0.3 part of silica fine particles having an average primary particle diameter of 140 nm are added to 100 parts by weight of the toner base. Part by weight, titanium oxide fine particles with an average primary particle size of 15 nm were blended so as to be 0.2 parts by weight, stirred and mixed with a super mixer, and then stored in a stationary state at 40 ° C. for 72 hours. Used as a photographic toner.

[Evaluation methods]
(Evaluation item)
(1) Loose apparent density Put 10 g of toner into a 50 ml graduated cylinder, cover and shake 50 times. The scale is read after leaving the lid open for 10 minutes and the ratio to the measured toner amount is taken as the measured value.
(2) Adhesion rate of external additive (3) Rising charge amount 6 g of developer stirred for a short time with a tumbler is weighed, charged into a metal cylinder that can be sealed, and blown to determine the charge amount. The toner concentration is adjusted to 6.5 to 7.5 wt%.
(4) Stain on the background Using an evaluation machine that has been tuned by remodeling Ricoh's IPSiO Color 8100 into an oilless fixing system, 30,000 sheets of 50% image area image charts are output in a single color mode, and then a blank image is being developed. The developer on the photoconductor after development was transferred to tape, and the difference from the image density of the untransferred tape was measured with a 938 spectrocytometer (manufactured by X-Rite). The smaller the difference in image density, the better the background dirt. ◎ indicates ΔID of less than 0.01, ◯ indicates ΔID is 0.01 to 0.02, Δ indicates ΔID is 0.02 to 0.05, and X indicates ΔID is 0.05 or more.
(5) Toner scattering Using an evaluation machine tuned by remodeling Ricoh's IPSiO Color 8100 into an oilless fixing system, each toner is used to perform an image area ratio of 5% and a chart continuous output durability test of 50,000 sheets. ◎ If there is no contamination inside the copier, ◎, slightly present but no problem in practical use ○, scatter amount is quite large, but image has no problem △, scatter amount is much on the image The level at which the problem occurred was marked as x.
(6) Charging stability Using an evaluation machine tuned by remodeling Ricoh's IPSiO Color 8100 into an oil-less fixing system, an image area ratio 7% chart continuous 100,000 sheet output durability test was conducted using each toner. The change in the charge amount was evaluated. 1 g of developer was weighed and the change in charge amount was determined by the blow-off method. When the change in the charge amount was 5 μc / g or less, it was evaluated as ◯, when it was 10 μc / g or less, Δ when it exceeded 10 μc / g.

  Table 1 shows the conditions for treating the external additive to the obtained toner, and Table 2 shows the evaluation results.

As can be seen with reference to Table 2, since the toners of the present invention according to Examples 1 to 3 have a sufficient rising charge amount and excellent charging stability, abnormal images such as background stains are also generated. No results were obtained.
In the toner of Example 3, by adding titanium oxide fine particles first, the adhesion rate of titanium oxide is further increased and the rising charge amount is increased as compared with Example 1 using the same mixer. It was.
On the other hand, since the toners according to Comparative Examples 1 to 3 are not subjected to the stationary storage process, the adhesion rate of the external additive is low, and the loose apparent density is also reduced. For this reason, it was inferior in charge rising property, and abnormal images such as background stains were generated.

FIG. 3 is a diagram schematically illustrating the shape of a toner for explaining a shape factor SF-1. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present invention.

Explanation of symbols

4 Developing device 10 Intermediate transfer belt (intermediate transfer member)
18 Image forming means 21 Exposure device 25 Fixing device 40 Photosensitive member (latent image carrier)
22 Secondary transfer device 62 Primary transfer means 100 Copier main body 200 Paper feed table 300 Scanner 400 Automatic document feeder

Claims (15)

An image forming toner having an external additive in toner particles containing at least a binder resin and a colorant,
The toner is characterized in that the adhesion rate of the external additive is 80% or more and the loose apparent density is in the range of 0.38 to 0.43. The toner according to claim 1.
The toner is characterized in that silica and / or titania is used as an external additive. The toner according to claim 1 or 2,
The toner according to claim 1, wherein the external additive having an adhesion rate of 80% or more is titania. The toner according to any one of claims 1 to 3,
The toner according to claim 1, wherein the external additive has an average particle size of 8 to 300 nm. In the toner according to any one of claims 1 to 4,
The toner has a volume average particle diameter of 3 to 8 μm, and the surface irregularity period λ and the number average particle diameter L of the external additive have a relationship of (1/2) λ> L. toner. The toner according to any one of claims 1 to 5,
The toner has a shape factor SF-1 in the range of 100 to 180. The toner according to any one of claims 1 to 6,
The toner particles of the toner include an inorganic filler in the vicinity of the surface. In a developer for developing an electrostatic latent image formed on an image carrier,
The developer according to any one of claims 1 to 7, wherein the developer contains a magnetic substance. In a developer for developing an electrostatic latent image formed on an image carrier,
The developer, wherein the toner according to any one of claims 1 to 7 is mixed with a magnetic carrier coated with a resin. In the developing device arranged to face the image carrier that carries the electrostatic latent image,
The developing device using the developer according to claim 8 or 9. A process cartridge that integrally supports an image carrier that carries an electrostatic latent image and at least a developing device that is disposed to face the image carrier that carries an electrostatic latent image, and is detachable from the image forming apparatus main body In
The process cartridge uses the developing device according to claim 10. In an image forming apparatus comprising: an image carrier that carries an electrostatic latent image; and at least a developing device that is disposed to face the image carrier that carries an electrostatic latent image.
The image forming apparatus using the developing device according to claim 10. A method for producing an image forming toner having an external additive in toner particles containing at least a binder resin and a colorant,
After the external additive is attached to the surface of the toner particles, a heat treatment is performed in a temperature range (T) of the following formula (1), and the heat treatment is performed in a state where the toner is left standing. Method.
1/2 Tg (° C.) ≦ T (° C.) ≦ T g (° C.) Formula (1)
(Where T is 25 ° C. or higher, and Tg is the glass transition temperature of the toner) The method for producing an image forming toner according to claim 13.
The method for producing an image forming toner, wherein the toner has an external additive adhesion rate of 80% or more and a loose apparent density in a range of 0.38 to 0.43. 15. The method for producing an image forming toner according to claim 13, wherein silica and titanium oxide are used as the external additive, and titanium oxide is first surface-treated. .

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