JP2013041065A - Electrostatic charge image developer, developer cartridge, image forming apparatus, and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charge image developer suppressing image contamination under high-humidity environment.SOLUTION: The electrostatic charge image developer includes: a toner comprising toner base particles and an external additive; and a carrier. The external additive includes specific silica particles and specific organic particles. The carrier is a resin-coated carrier including a core material, and a coating resin layer including a conductive material and a crosslinkable resin and formed on the core material surface. The content w1 of the specific silica particles and the content w2 of the specific organic particles satisfy the following expression (1): 1.0≤w1/w2≤10.0. A ratio wc (wt.%) of particles of the carrier with the grain size of not less than 22 μm and not more than 31 μm to the developer, and a ratio w2' (wt.%) of the specific organic particles to the developer satisfy the following expression (2): 2.0×10≤w2'/wc≤5.0×10.

Description

  The present invention relates to an electrostatic charge image developer, a developer cartridge, an image forming apparatus, and an image forming method.

  As an image forming apparatus using an electrophotographic system, the use in an on-demand printing area is expanding from the use in a conventional office, and a high-speed machine with high image quality and high reliability is demanded. The printed matter printed at a high speed in this way becomes a final output through post-processing steps such as cutting, folding, and bookbinding.

There are various reports on the design of external additives, and Patent Document 1 discloses a developer applied to an image carrier having a surface roughness Rz of 1.0 or less in order to improve chargeability and storage stability. A developer comprising a toner containing toner particles containing a colorant and a binder resin, silica particles, and metal soap, wherein the weight ratio of the silica particles to the metal soap is 10 to 60 times is disclosed. ing.
In Patent Document 2, for the purpose of stabilizing the charge amount, a colorant, a binder resin, titanium oxide, silica having a BET specific surface area of 50 m ² / g or less, and a volume average particle diameter of 5 μm or less. There is disclosed a developer characterized by containing a metal soap having
Patent Document 3 discloses a two-component composition containing a toner in which an external additive is added to toner base particles containing a binder resin and a colorant and a carrier in order to suppress a decrease in image density and the like. A developer, wherein the external additive is 0.05 to 2.0 parts by weight of hydrophobic silica A having a number average particle diameter of 5 to 20 nm and a number average particle diameter of 100 parts by weight of toner base particles. 0.05 to 2.0 parts by weight of hydrophobic titania having a particle diameter of 5 to 40 nm, 1.0 to 5.0 parts by weight of hydrophobic silica B having a number average particle diameter of more than 20 nm and 70 nm or less, and weight average particles 0.1 to 1.0 part by weight of strontium titanate having a diameter of 30 to 75 nm and 0.01 to 0.1 part by weight of zinc stearate having a volume median particle size of 1.5 to 12 μm A two-component developer is disclosed.

JP 2002-107998 A JP 2001-51443 A JP 2010-44113 A

  An object of the present invention is to provide an electrostatic charge image developer in which image smearing is suppressed in a high humidity environment.

The above-mentioned problems of the present invention have been solved by the means described in <1>, <8>, <9> and <11> below. It is shown below with <2>-<7>, <10> and <12> which are preferable embodiments.
<1> A toner and a carrier are contained, and the toner includes toner base particles containing a binder resin, a colorant, an infrared absorber, and a release agent, and an external additive. Silica particles, and organic particles, wherein the silica particles are surface-treated with an amino group-containing silane coupling agent and have a number average primary particle size of 5 nm to 20 nm. The organic particles are organic particles having a volume average particle size of 0.5 μm or more and 15 μm or less and an endothermic peak by differential scanning calorimetry of 80 ° C. or more and 140 ° C. or less, and the carrier includes a core material, A resin-coated carrier having a conductive resin and a coating resin layer containing a crosslinkable resin on the surface of the core material, the content of the silica particles with respect to 100 parts by weight of toner base particles being w1 (parts by weight), When the content of the toner mother particles 100 parts by weight of serial organic particles was w2 (parts by weight), satisfies the following formula (1),
1.0 ≦ w1 / w2 ≦ 10.0 (1)
When the proportion of particles having a particle size of 22 μm or more and 31 μm or less of the carrier in the developer is wc (wt%) and the proportion of the organic particles in the developer is w2 ′ (wt%), the following formula (2) An electrostatic charge image developer characterized by satisfying
2.0 × 10 ⁻⁴ ≦ w2 ′ / wc ≦ 5.0 × 10 ⁻³ (2)

<2> The electrostatic charge according to <1>, wherein the binder resin contains an amorphous polyester and a crystalline polyester, and an endothermic peak by differential scanning calorimetry of the crystalline polyester is 60 ° C. or higher and 120 ° C. or lower. Image developer,
<3> The electrostatic image developer according to <1> or <2>, wherein the organic particles contain at least one selected from the group consisting of fatty acid metal salts, higher fatty acids, and higher alcohols,
<4> The electrostatic charge image developer according to any one of <1> to <3>, wherein the resin-coated carrier is coated with a silicone resin.
<5> The electrostatic charge image developer according to any one of <1> to <4>, wherein the carrier has a volume average particle size of 15 μm to 60 μm.
<6> The electrostatic charge image developer according to any one of <1> to <5>, wherein the toner is a positively chargeable toner,
<7> The electrostatic charge image developer according to any one of <1> to <6>, which is for photofixing;
<8> The electrostatic charge according to any one of <1> to <7>, wherein the electrostatic charge is attached to and detached from an image forming apparatus including a light fixing unit that irradiates and fixes a toner image on a surface of a transfer target. A developer cartridge containing an image developer;
<9> The image holding member, an electrostatic latent image forming unit that forms an electrostatic latent image on a surface of the image holding member, and the electrostatic latent image according to any one of <1> to <7>. Developing means for developing a toner image by developing with an electrostatic charge image developer, transfer means for transferring the toner image to the surface of the transfer target, and fixing the toner image transferred to the surface of the transfer target by light fixing An image forming apparatus comprising at least a fixing unit.
<10> The image forming apparatus according to <9>, wherein the developing unit includes a plurality of developer holders having a peripheral speed of 1,000 mm / s or more.
<11> A charging step for charging the surface of the image carrier, an electrostatic latent image forming step for forming an electrostatic latent image on the surface of the image carrier, and developing the electrostatic latent image with a developer containing toner to form a toner image. And a fixing step of fixing the transferred toner image to the transferred material by a light fixing method, wherein the developer is <1. >-<7>, wherein the electrostatic image developer according to any one of the above,
<12> The image forming method according to <11>, wherein the developer holding member that holds the developer has a peripheral speed of 1,000 mm / s or more.

According to the invention described in the above <1>, an electrostatic charge image developer in which image smearing under a high humidity environment is suppressed as compared with the case where this configuration is not provided.
According to the invention described in the above <2>, the electrostatic charge in which image staining in a high-humidity environment is further suppressed as compared with a case where a crystalline polyester resin having an endothermic peak of less than 60 ° C. or more than 120 ° C. An image developer is provided.
According to the invention described in the above <3>, an electrostatic charge image developer in which image smearing in a high humidity environment is further suppressed by using specific organic particles is provided.
According to the invention described in <4>, there is provided an electrostatic charge image developer in which image contamination in a high humidity environment is further suppressed as compared with a case where the carrier is not coated with a silicone resin.
According to the invention described in <5> above, there is provided an electrostatic charge image developer in which image staining in a high humidity environment is further suppressed as compared with a case where the volume average particle size of the carrier is less than 15 μm or more than 60 μm. Provided.
According to the invention described in <6>, there is provided an electrostatic charge image developer in which image staining in a high humidity environment is further suppressed when used as a positively chargeable toner.
According to the invention described in the above <7>, there is provided an electrostatic charge image developer in which image contamination in a high humidity environment is suppressed even when used in a photofixing system in which image contamination is likely to occur.
According to the invention described in <8>, there is provided a developer cartridge in which image contamination in a high humidity environment is suppressed as compared with the case where the present configuration is not provided.
According to the invention described in <9>, there is provided an image forming apparatus in which image contamination in a high humidity environment is suppressed as compared with a case where the present configuration is not provided.
According to the invention described in <10> above, even when the developer holding member having a peripheral speed of 1,000 mm / s or more is provided, the image is easily stained in the high humidity environment. A suppressed image forming apparatus is provided.
According to the invention described in <11> above, an image forming method in which image contamination in a high-humidity environment is suppressed as compared with the case where the present configuration is not provided.
According to the invention described in <12>, image stains in a high-humidity environment are suppressed even when image stains are likely to occur and the peripheral speed of the development holding member is 1,000 m / s or more. An image forming method is provided.

1 is a schematic diagram illustrating an example of an image forming apparatus according to an exemplary embodiment.

Hereinafter, this embodiment will be described in detail.
In the present embodiment, the description “A to B” represents not only a range between A and B but also a range including A and B at both ends thereof. For example, if “A to B” is a numerical value range, “A or more and B or less” or “B or more and A or less” is represented according to the magnitude of the numerical value.

(Electrostatic image developer)
The electrostatic charge image developer (hereinafter, also simply referred to as “developer”) of the present embodiment includes a toner and a carrier, and the toner includes a binder resin, a colorant, an infrared absorber, and a release agent. Toner particles containing an external additive, the external additive contains silica particles and organic particles, and the silica particles are surface-treated with a silane coupling agent containing an amino group. And the silica particles having a number average primary particle size of 5 nm to 20 nm, the organic particles have a volume average particle size of 0.5 μm to 15 μm, and have an endothermic peak of 80 by differential scanning calorimetry. The carrier is a resin-coated carrier having a core material and a coating resin layer containing a conductive material and a crosslinkable resin on the surface of the core material, and the silica particles. of When the content with respect to 100 parts by weight of the toner base particles is w1 (parts by weight) and the content of the organic particles with respect to 100 parts by weight of the toner base particles is w2 (parts by weight), the following formula (1) is satisfied:
1.0 ≦ w1 / w2 ≦ 10.0 (1)
When the proportion of particles having a particle size of 22 μm or more and 31 μm or less of the carrier in the developer is wc (wt%) and the proportion of the organic particles in the developer is w2 ′ (wt%), the following formula (2) It is characterized by satisfying.
2.0 × 10 ⁻⁴ ≦ w2 ′ / wc ≦ 5.0 × 10 ⁻³ (2)
The electrostatic charge image developer according to the exemplary embodiment is suitable as a developer for photofixing, and is particularly suitable for image formation at high speed.

As a high-speed fixing method, an optical fixing method is preferably used because it is less likely to cause a paper jam or less likely to cause an offset.
Conventionally, when an image such as a fine line or a character is formed, there is a problem that after the image is formed, for example, when the line portion is rubbed with a nail-like object, the image is damaged and stains are generated. The inventors of the present invention have found that such image contamination is remarkable when the water content of the paper is large, particularly under high humidity, and that the image contamination is particularly remarkable in the case of the light fixing method. .
As a result of intensive studies by the present inventors on the subject, the degree of image contamination is changed by adding specific silica particles and specific organic particles, and the surface properties and particle size distribution of carrier particles are further changed. By considering this, it has been found that image smearing is improved, and the present invention has been completed.
Although the mechanism is not necessarily clear, the following mechanism of action is presumed. In the following description, the case where the light fixing method is used will be described. However, the same mechanism is assumed when other fixing methods are used.

First, when a toner that does not have the configuration of the present embodiment is used, and when an image is formed by photofixing fine lines, characters, and the like, it is non-contact fixing and pressure is not applied to the image itself. Unevenness is formed on the surface. At this time, compared to a solid image, the fine lines tend to be fragile because the number of toners forming the image is small. Furthermore, when the moisture content of the paper is high under high humidity, it is considered that the moisture in the paper evaporates at the time of fixing, so that the fixability becomes weak and the line image and the paper are easily peeled off. In such a case, when the print image is rubbed, a part of the image is destroyed and recognized as a line defect or image smudge. For example, even if a release agent or the like is contained in the toner, such image defects and stains are not sufficiently improved because the adhesion between the image and the paper is insufficient.
On the other hand, when the developer of this embodiment is used, the following mechanism is considered to work. That is, when the organic particles in the toner are stirred in the developer, some of the organic particles move to the carrier surface. At this time, if the carrier surface is coated with a coating resin layer containing a crosslinkable resin, silica particles adhering to the carrier can be prevented from being embedded in the carrier surface layer. It is possible to realize a form in which silica particles are present. Thereby, it can prevent that organic particles adhere firmly to the carrier surface. Furthermore, the organic particles whose surfaces are coated with silica particles can be present in a weakly attached state on the carrier surface.

  When a line image or the like is formed using such a developer, it is considered that a part of the organic particles covered with the silica particles are developed and transferred, and exist on and around the image. At this time, the organic particles that are not in contact with the toner particles are not fixed by light fixing, and thus are considered to be removed naturally in the subsequent steps without affecting the paper. On the other hand, the organic particles in contact with the toner particles are melted by heat when the toner particles are fixed by light fixing, and only the image surface is covered. At this time, in the photofixing, the toner particles containing the infrared absorber are melted first, and then the organic particles are melted. Therefore, it is assumed that the adhesion between the image and the paper is not hindered by the organic particles. Since the organic particles covering the image provide a friction reducing effect and an image protecting effect, it is considered that even fine lines are not lost due to external rubbing and image smearing is not caused.

<Toner>
The electrostatic image developer of this embodiment contains a toner and a carrier. Note that the electrostatic image developer of the exemplary embodiment is preferably composed of toner and carrier.
The toner includes toner mother particles and an external additive, and the toner mother particles contain a binder resin, a colorant, an infrared absorber, and a release agent.
Hereinafter, the external additive and toner base particles constituting the toner will be described in more detail.

[External additive]
In the present embodiment, the external additive contains silica particles and organic particles. The silica particles are silica particles that are surface-treated with a silane coupling agent containing an amino group and have a number average primary particle size of 5 nm or more and 20 nm or less, and the organic particles have a volume average particle size of 0.00. Organic particles having an endothermic peak of 5 ° C. or more and 15 μm or less and an endothermic peak by differential scanning calorimetry of 80 ° C. or more and 140 ° C. or less. When the content of the organic particles relative to 100 parts by weight of toner base particles is w2 (parts by weight), the following formula (1) is satisfied.
1.0 ≦ w1 / w2 ≦ 10.0 (1)

-Silica particles-
In the present embodiment, silica particles that are surface-treated with a silane coupling agent containing an amino group as an external additive and have a number average primary particle size of 5 nm to 20 nm (hereinafter also referred to as “specific silica particles”). Containing. By using the specific silica particles treated with a silane coupling agent containing an amino group, it is considered that the adhesion to the organic particles is kept good and further good developability is imparted to the organic particles. In addition, since the specific silica particles are positively charged by having an amino group, the toner of the present exemplary embodiment is preferably used as a positively chargeable toner.
The silane coupling agent having an amino group in the specific silica particle may be physically attached to the surface of the silica particle or may be chemically bonded, but chemically bonded to the surface of the silica particle. It is preferable.
In addition, in this embodiment, what is necessary is just to contain said specific silica particle as an external additive, and inclusion of another silica particle is not excluded.

As the silane coupling agent having an amino group, known ones are used. Specifically, for example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl)- 3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyl Examples include trimethoxysilane.
Silica particles may be used in combination with a surface treatment with a silane coupling agent having an amino group, in addition to a surface treatment with a known treatment agent such as a silane coupling agent having no amino group or silicone oil.

  Examples of silane coupling agents having no amino group include methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, ethyltrimethoxysilane, and propyl. Trimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, butyltrimethoxy Silane, butyltriethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimeth Sisilane, decyltrimethoxysilane, hexadecyltrimethoxysilane, trimethyltrimethoxysilane, hexamethyldisilazane, N, O- (bistrimethylsilyl) acetamide, N, N-bis (trimethylsilyl) urea, tert-butyldimethylchlorosilane, vinyl Trichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxy Silane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane Trifluoropropyltrimethoxysilane, tridecafluorooctyltrimethoxysilane, hepadecafluorodecyltrimethoxysilane, heptadecafluorodecylmethyldimethoxysilane, Decafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, heptadecafluoro-1,1,2,2-tetrahydrodecyltriethoxysilane, 3- Fluorine silane compounds such as heptafluoroisopropoxypropyltriethoxysilane can be used.

  Silicone oils include dimethyl silicone oil, methyl hydrogen silicone oil, methyl phenyl silicone oil, cyclic dimethyl silicone oil, epoxy modified silicone oil, carboxyl modified silicone oil, carbinol modified silicone oil, methacryl modified silicone oil, mercapto modified silicone oil. Polyether-modified silicone oil, methylstyryl-modified silicone oil, alkyl-modified silicone oil, amino-modified silicone oil, fluorine-modified silicone oil and the like can be used.

The number average primary particle size of the specific silica particles is 5 nm or more and 20 nm or less. When the number average primary particle size is 5 nm or more, the silica particles are prevented from being buried in the irregularities on the carrier surface, the adhesion between the organic particles and the carrier is suitably controlled, and image loss and image contamination are suppressed. Moreover, when it is 20 nm or less, the adhesion between the silica particles and the organic particles is excellent, the adhesion between the organic particles and the carrier is suitably controlled, and the occurrence of image defects and image contamination is suppressed.
The number average primary particle size of the specific silica particles is preferably 6 to 18 nm, and more preferably 7 to 16 nm. It is preferable that the number average primary particle size of the specific silica particles is in the above range since image defects and image contamination are further suppressed.

  Further, when the content of the specific silica particles with respect to 100 parts by weight of the toner base particles is w1 (parts by weight), w1 is preferably 0.1 to 3.0 parts by weight, more preferably 0.2 to 2.5 parts by weight. Preferably, 0.3 to 2.0 parts by weight is more preferable. When w1 is 0.1 parts by weight or more, the toner has excellent fluidity and good image quality can be obtained. On the other hand, if it is 3.0 parts by weight or less, the toner fixing property is not hindered.

-Organic particles-
In the present embodiment, as the external additive, organic particles having a volume average particle size of 0.5 μm or more and 15 μm or less and an endothermic peak by differential scanning calorimetry of 80 ° C. or more and 140 ° C. or less (hereinafter referred to as “specific organic”). Also referred to as “particles”).
As the specific organic particles, known organic particles having an endothermic peak of 80 ° C. or higher and 140 ° C. or lower by differential scanning calorimetry can be used. In order to effectively reduce image smearing, fatty acid metal salts, higher fatty acids are used. And at least one selected from the group consisting of higher alcohols.
Specifically, the fatty acid metal salt having an endothermic peak of 80 ° C. or higher and 140 ° C. or lower by differential scanning calorimetry includes magnesium stearate, zinc stearate, aluminum stearate, zinc behenate, magnesium behenate, zinc laurate. Zinc ricinoleate, barium ricinoleate, zinc undecylenate, zinc myristate, zinc palmitate and the like. Examples of the higher fatty acid having an endothermic peak of 80 ° C. or higher and 140 ° C. or lower by differential scanning calorimetry include higher fatty acids having approximately 22 or more carbon atoms. Examples of the higher alcohol having an endothermic peak of 80 ° C. or higher and 140 ° C. or lower by differential scanning calorimetry include higher alcohols having approximately 28 or more carbon atoms.

The endothermic peak in the differential scanning calorimetry of the specific organic particles is 80 ° C. or higher and 140 ° C. or lower. When the endothermic peak is 80 ° C. or higher, the organic particles can suppress image smear without impairing fixability, and when it is 140 ° C. or lower, the image surface can be sufficiently covered to suppress image smudge. can do.
The endothermic peak in the differential scanning calorimetry of the specific organic particles is preferably 82 to 138 ° C, more preferably 85 to 135 ° C, and still more preferably 85 to 130 ° C. It is preferable that the endothermic peak is within the above range because image smearing is suppressed without impairing the fixing property.

  In this embodiment, the measurement of the endothermic peak by the differential scanning calorimeter of the specific organic particles is performed according to ASTM D3418-8 using a differential scanning calorimeter (manufactured by Shimadzu Corporation: DSC-60A) at room temperature (25 From 150 ° C.) to 150 ° C. under a temperature rising rate of 10 ° C./min.

The volume average particle diameter of the specific organic particles is 0.5 μm or more and 15 μm or less. When it is 0.5 μm or more, the adhesion force with the toner particles is in an appropriate range, the presence of specific organic particles between the toner and the paper is suppressed, and the fixing property is not inhibited, so that the image defect is suppressed. Further, if it is 15 μm or less, adhesion of specific organic particles and carrier particles occurs moderately, and image smearing is suppressed by effectively covering the image, which is preferable.
The volume average particle diameter of the specific organic particles is preferably 0.6 to 12 μm, more preferably 0.8 to 11 μm, and still more preferably 1 to 10 μm. It is preferable that the volume average particle diameter of the specific organic particles is within the above range because image smearing is suppressed without impairing the fixing property.

Further, when the content of the specific organic particles with respect to 100 parts by weight of the toner base particles is w2 (parts by weight), w2 is preferably 0.1 to 1.2 parts by weight. The amount of 0.1 part by weight or more is preferable because it is an effective amount for protecting the image, and image loss and image contamination are suppressed. Further, the amount of 1.2 parts by weight or less is preferable because the amount of organic particles present on the surface of the carrier is appropriate, charging failure of the toner is suppressed, and generation of fog is suppressed.
w2 is more preferably 0.15 to 1.0 part by weight, and still more preferably 0.2 to 0.9 part by weight.

The content w1 (parts by weight) of the specific silica particles with respect to 100 parts by weight of the toner base particles and the content w2 (parts by weight) of the specific organic particles with respect to 100 parts by weight of the toner base particles satisfy the following formula (1).
1.0 ≦ w1 / w2 ≦ 10.0 (1)
When w1 / w2 is 1.0 or more, the amount of the specific silica particles adhering to the surface of the specific organic particles is appropriate, the specific organic particles are prevented from sticking to the carrier surface, and effective in order to protect the image. The specific organic particles are developed, and the occurrence of image defects and image contamination is suppressed, which is preferable. Moreover, it is preferable that it is 10.0 or less because the amount of the specific silica particles adhering to the specific organic particles is appropriate, and image defects and image contamination are suppressed without inhibiting the melting of the specific organic particles.
w1 / w2 is preferably 1.5 or more and 8.5 or less, and more preferably 2.0 or more and 7.5 or less. When w1 / w2 is within the above range, image loss and image contamination are further suppressed.

In the exemplary embodiment, the toner may use, in addition to the specific silica particles and the specific organic particles, known inorganic particles or organic particles as an external additive.
Examples of inorganic particles include silica powder (silica powder other than the specific silica particles), alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc 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.
Further, as organic particles other than the specific organic particles, for example, vinyl polymers such as styrene polymers, (meth) acrylic polymers, ethylene polymers, ester-based, melamine-based, amide-based, allyl phthalate-based, etc. And various organic polymers and organic particles made of a fluoropolymer such as vinylidene fluoride.
The external additive can be further externally added by mixing it with a desired additive as required, using a mixer such as a Henschel mixer.

[Toner mother particles]
In the present exemplary embodiment, the toner includes toner base particles containing at least a binder resin, a colorant, an infrared absorber, and a release agent, and an external additive.
Hereinafter, each component in the toner base particles will be described in detail.

-Binder resin-
In this embodiment, the toner base particles contain a binder resin.
As the binder resin, known amorphous resins and crystalline resins can be used, and in particular, amorphous polyester (hereinafter also referred to as “amorphous polyester” or “amorphous polyester”) and crystallinity. It is preferable to contain polyester. The inclusion of the amorphous polyester and the crystalline polyester is preferable in that the toner particles are melted more quickly than the specific organic particles, a good fixing property can be obtained, and fixing inhibition by the specific organic particles can be prevented.

≪Crystalline polyester≫
The crystalline polyester resin in this embodiment will be described below. In this embodiment, “crystallinity” refers to having a clear endothermic peak in differential scanning calorimetry (DSC), and specifically, when measured at a heating rate of 10 ° C./min. It means that the half-value width of the endothermic peak is within 15 ° C. On the other hand, a resin having a half-value width of an endothermic peak exceeding 15 ° C. or a resin having no clear endothermic peak means amorphous.
The crystalline polyester is synthesized from an acid (polycarboxylic acid, preferably dicarboxylic acid) component and an alcohol (polyol, preferably diol) component. In the present embodiment, a copolymer obtained by copolymerizing other components at a ratio of 50% by weight or less with respect to the main chain of the crystalline polyester is also referred to as a crystalline polyester.

  The acid (polycarboxylic acid) component preferably contains an aliphatic dicarboxylic acid. For example, succinic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,10-undecanedicarboxylic acid Acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, etc., or lower alkyl esters thereof, An acid anhydride is mentioned. Further, it may contain a dicarboxylic acid component having an ethylenically unsaturated bond such as fumaric acid, maleic acid, 3-hexenedioic acid, and 3-octenedioic acid.

  On the other hand, the alcohol (polyol) component preferably contains an aliphatic diol, such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1, 6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13 -Tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,20-eicosanediol and the like are exemplified, but not limited thereto.

The content of the crystalline polyester with respect to the toner base particles is preferably 2% by weight or more and 40% by weight or less. More preferably, they are 3 weight% or more and 30 weight% or less, More preferably, they are 4 weight% or more and 25 weight% or less.
When the content of the crystalline polyester is within the above range, the low-temperature fixability is excellent and the heat storage property of the toner can be kept good.

≪Amorphous polyester≫
A known amorphous polyester resin can be used as the amorphous polyester resin. As the acid component, various dicarboxylic acids mentioned for the crystalline polyester resin can be used in the same manner. In addition, aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid, succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms such as dodecenyl succinic acid and octyl succinic acid, and the like Acid anhydrides of these acids and alkyl (C1-C8, preferably 1 to 3) esters of these acids are preferably used.
Trivalent or higher carboxylic acids include trimellitic acid, pyromellitic acid, 1,2,4-cyclohexanetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 2,5-hexanetricarboxylic acid, 1,2,7,8-octanetetracarboxylic acid or acid anhydrides or lower alkyl esters thereof may be used. These may be used individually by 1 type and may use 2 or more types together.

  As the alcohol component, various diols used for the synthesis of the crystalline polyester resin can be used. In addition to the aliphatic diols mentioned for the crystalline polyester resin, polyoxypropylene (2.2) -2,2 -Bisphenol A alkylene (2 to 3 carbon atoms) oxide (average number of moles added) such as bis (4-hydroxyphenyl) propane and polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane 1-10) Adducts, hydrogenated bisphenol A, and the like can be used. Further, as trihydric or higher alcohols, sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1 , 2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane and other aliphatic polyhydric alcohols having 3 to 20 carbon atoms, Examples include aromatic polyhydric alcohols having 6 to 20 carbon atoms such as 1,3,5-trihydroxylmethylbenzene, and alkylene oxide adducts thereof. These may be used individually by 1 type and may use 2 or more types together.

  The endothermic peak of the crystalline polyester resin by a differential scanning calorimeter, that is, the crystalline melting point Tm is preferably 60 to 120 ° C, more preferably 62 to 115 ° C, and still more preferably 64 to 110 ° C. . When Tm is 60 ° C. or higher, an appropriate image intensity can be obtained and image smearing can be suppressed. Further, when Tm is 120 ° C. or less, the image surface is covered with the specific organic particles in a state where the toner base particles are sufficiently melted, so that image smear can be suppressed.

Moreover, it is preferable that A> B when the endothermic peak temperature by differential scanning calorimetry of the specific organic particles is A ° C. and the crystalline melting point of the crystalline polyester resin is B ° C. Since the crystalline polyester resin of the toner base particles is melted first, and then the specific organic particles are melted, the image is effectively protected by the melted specific organic particles.
“A-B” is preferably 2 to 80 ° C., more preferably 5 to 75 ° C., more preferably 8 to 70 ° C., and still more preferably 10 to 65 ° C. It is preferable that the difference between the endothermic peak of the specific organic particles and the crystalline melting point of the crystalline polyester resin is within the above range because image staining is further suppressed.

  The glass transition temperature Tg of the amorphous polyester resin is preferably 40 to 80 ° C, more preferably 45 to 70 ° C. When the Tg is 40 ° C. or higher, the fluidity of the toner particles can be kept good even at high temperatures. Further, when Tg is 80 ° C. or lower, sufficient melting can be obtained, and the minimum fixing temperature can be lowered.

Here, for measuring the crystalline melting point of the crystalline resin, a differential scanning calorimeter (DSC) was used to measure JIS K when measured from room temperature (20 ° C.) to 150 ° C. at a heating rate of 10 ° C. per minute. It can be obtained as the melting peak temperature of the input compensated differential scanning calorimetry shown in −7121. Although the crystalline resin may show a plurality of melting peaks, in this embodiment, the maximum peak is regarded as the melting point.
Moreover, the glass transition temperature of an amorphous resin means the value measured by the method (DSC method) prescribed | regulated to ASTMD3418-82.

Moreover, it is preferable that the weight average molecular weights of the polyester resin used for this embodiment are 4,000-100,000, and it is more preferable that it is 6,000-80,000. When the weight average molecular weight is 4,000 or more, a good cohesive force can be obtained as a binder resin, and the hot offset property is excellent. Further, when the weight average molecular weight is 100,000 or less, good hot offset property and a suitable minimum fixing temperature can be obtained.
Further, the polyester resin used in the present embodiment may have a partially branched or crosslinked structure depending on the selection of the carboxylic acid valence and alcohol valence of the polycondensable monomer.

  In addition to polyester resins, binder resins include copolymers of styrene and acrylic acid or methacrylic acid, polyvinyl chloride resins, phenol resins, acrylic resins, methacrylic resins, polyvinyl acetate, silicone resins, polyurethane resins, polyamides Resins, furan resins, epoxy resins, xylene resins, polyvinyl butyral, terpene resins, coumarone indene resins, petroleum resins, polyether polyol resins, and the like can be used in combination.

  Further, the content of the binder resin in the toner base particles in the toner of the exemplary embodiment is not particularly limited, but is preferably 30 to 99% by weight with respect to the total weight of the toner base particles, and 40 to 40%. It is more preferably 98% by weight, and still more preferably 50 to 96% by weight. Within the above range, the fixing property, storage property, powder property, charging property and the like are excellent.

-Colorant-
In the present embodiment, the toner base particles contain a colorant.
As the colorant, known ones can be used, and may be arbitrarily selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP permeability, and dispersibility in the toner.
For example, in cyan toner, as the colorant, for example, C.I. I. Pigment Blue 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 13, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 17, 17, 23, 60, 65, 73, 83, 180, C.I. I. Vat cyan 1, 3 and 20, etc., bitumen, cobalt blue, alkali blue lake, phthalocyanine blue, metal-free phthalocyanine blue, partially chlorinated phthalocyanine blue, first sky blue, indanthrene blue BC cyan pigment, C.I. I. Cyan dyes such as solvent cyan 79 and 162 are used.
In the magenta toner, as the colorant, for example, C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 49, 70, 51, 52, 53, 54, 55, 57, 58, 60, 63, 64, 68, 81, 83, 87, 88, 89, 90 112, 114, 122, 123, 163, 184, 185, 202, 206, 207, 209, 238, etc., pigment violet 19 magenta pigments, C.I. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 30, 49, 81, 82, 83, 84, 100, 109, 121, C . I. Disper thread 9, C.I. I. Basic Red 1, 2, 9, 9, 13, 14, 15, 17, 17, 18, 22, 23, 24, 27, 29, 32, 34, the same 35, 36, 37, 38, 39, 40, etc. Magenta dyes, etc., Bengala, Cadmium Red, Lead Tan, Mercury Sulfide, Cadmium, Permanent Red 4R, Resol Red, Pyrazolone Red, Watching Red, Calcium Salt, lake red D, brilliant carmine 6B, eosin lake, rotamin lake B, alizarin lake, brilliant carmine 3B and the like are used.
In the yellow toner, as the colorant, for example, C.I. I. Pigment Yellow 2, 3, 15, 15, 17, 74, 93, 97, 128, 155, 180, 185, 139, and the like are used.
In the black toner, as the colorant, for example, carbon black, activated carbon, titanium black, magnetic powder, Mn-containing nonmagnetic powder, or the like is used. Further, black toner may be obtained by mixing yellow, magenta, cyan, red, green, and blue pigments.

  The amount of the colorant used is preferably 0.1 to 20 parts by weight and more preferably 0.5 to 15 parts by weight with respect to 100 parts by weight of the toner base particles. Moreover, as a coloring agent, these pigments, dyes, etc. can be used individually by 1 type, or 2 or more types can be used together.

-Release agent-
In the toner of this embodiment, the toner base particles contain a release agent.
Specific examples of the release agent include, for example, ester wax, polyethylene, polypropylene, or a copolymer of polyethylene and polypropylene, but polyglycerin wax, microcrystalline wax, paraffin wax, carnauba wax, sazol wax, and montanic acid ester. Wax, deacidified carnauba wax, palmitic acid, stearic acid, montanic acid, blandic acid, eleostearic acid, valinalic acid and other unsaturated fatty acids, stearyl alcohol, aralkyl alcohol, bephenyl alcohol, carnauvyl alcohol, ceryl alcohol Saturated alcohols such as melylsil alcohol, or long-chain alkyl alcohols having a long-chain alkyl group; polyhydric alcohols such as sorbitol; linoleic acid amide, Fatty acid amides such as lane amide, lauric acid amide; saturated fatty acid bisamides such as methylene bis stearic acid amide, ethylene biscapric acid amide, ethylene bis lauric acid amide, hexamethylene bis stearic acid amide, ethylene bis oleic acid amide, Unsaturated fatty acid amides such as hexamethylene bisoleic acid amide, N, N′-dioleyl adipic acid amide, N, N′-dioleyl sebacic acid amide; m-xylene bisstearic acid amide, N, N′— Aromatic bisamides such as distearyl isophthalic acid amide; fatty acid metal salts such as calcium stearate, calcium laurate, zinc stearate, magnesium stearate (generally called metal soap); aliphatic hydrocarbon wax and styrene And Waxes grafted with vinyl monomers such as crylic acid; Fatty acids such as behenic acid monoglycerides and partially esterified products of polyhydric alcohols; Methyl ester compounds having hydroxyl groups obtained by hydrogenation of vegetable oils, etc. Is mentioned.

  The said mold release agent may be used individually by 1 type, or may use 2 or more types together. It is preferable to contain in the range of 1-20 weight% with respect to 100 weight% of binder resin, and it is more preferable to contain in the range of 3-15 weight%. Within the above range, both good fixing and image quality characteristics can be achieved.

-Infrared absorber-
The toner base particles in the toner of the present embodiment contain an infrared absorber.
As the infrared absorber used in the present embodiment, a known infrared absorber can be used. For example, a cyanine compound, a merocyanine compound, a benzenethiol metal complex, a mercaptophenol metal complex, an aromatic diamine metal complex, Diimonium compounds, aminium compounds, nickel complex compounds, phthalocyanine compounds, anthraquinone compounds, naphthalocyanine compounds, and the like can be used.
Among the colorants described above, those having absorption in the infrared region such as carbon black are also used as infrared absorbers. In this case, the colorant and the infrared absorber may be the same component.

  Specific infrared absorbers include nickel metal complex infrared absorbers (Mitsui Chemical Co., Ltd .: SIR-130, SIR-132), bis (dithiobenzyl) nickel (Midori Chemical Co., Ltd .: MIR-101). ), Bis [1,2-bis (p-methoxyphenyl) -1,2-ethylenedithiolate] nickel (manufactured by Midori Chemical Co., Ltd .: MIR-102), tetra-n-butylammonium bis (cis-1, 2-diphenyl-1,2-ethylenedithiolate) nickel (manufactured by Midori Chemical Co., Ltd .: MIR-1011), tetra-n-butylammonium bis [1,2-bis (p-methoxyphenyl) -1,2- Ethylene dithiolate] nickel (manufactured by Midori Chemical Co., Ltd .: MIR-1021), bis (4-tert-1,2-butyl-1,2-dithiophenolate) Neckel-tetra-n-butylammonium (manufactured by Sumitomo Seika Co., Ltd .: BBDT-NI), cyanine infrared absorber (manufactured by Fuji Film Co., Ltd .: IRF-106, IRF-107), cyanine infrared absorber ( Yamamoto Kasei Co., Ltd., YKR2900), aminium, diimonium-based infrared absorbers (Nagase Chemtex Co., Ltd .: NIR-AM1, IM1), imonium compounds (Nippon Carlit Co., Ltd .: CIR-1080, CIR-1081) ), Aminium compounds (Nippon Carlit Co., Ltd .: CIR-960, CIR-961), anthraquinone compounds (Nippon Kayaku Co., Ltd .: IR-750), aminium compounds (Nippon Kayaku Co., Ltd .: IRG-002, IRG-003, IRG-003K), polymethine compound (manufactured by Nippon Kayaku Co., Ltd .: IR-820) ), Diimonium compounds (Nippon Kayaku Co., Ltd .: IRG-022, IRG-023), dianine compounds (Nippon Kayaku Co., Ltd .: CY-2, CY-4, CY-9), soluble phthalocyanine ( Nippon Shokubai Co., Ltd .: TX-305A), Naphthalocyanine (Yamamoto Kasei Co., Ltd .: YKR5010, Sanyo Dye Co., Ltd .: Sample 1), Inorganic Materials (Shin-Etsu Chemical Co., Ltd .: Ytterbium UU-) HP, manufactured by Sumitomo Metal Industries, Ltd .: Injumetin oxide) and the like.

You may use an infrared absorber individually by 1 type or in combination of 2 or more types.
The content of the infrared absorber is preferably 0.1 to 16 parts by weight, more preferably 0.2 to 14 parts by weight, and more preferably 0.3 to 12 parts by weight with respect to 100 parts by weight of the toner base particles. More preferably, it is part by weight. It is preferable for the content of the infrared absorber to be in the above-mentioned range since good fixability can be obtained as a light fixing toner.

-Charge control agent-
In the present embodiment, the toner may contain a charge control agent as necessary.
There is no restriction | limiting in particular as said charge control agent, According to the objective, a well-known thing can be used. For example, as a positively chargeable charge control agent, a nigrosine dye, a quaternary ammonium salt such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and the like, phosphonium which is an analog thereof Onium salts such as salts, and lake pigments thereof; triphenylmethane dyes; metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, and dicyclohexyltin oxide; diorganotin borates such as dibutyltin borate; Examples thereof include guanidine compounds, imidazole compounds, and aminoacrylic resins.
Examples of the negatively chargeable charge control agent include trimethylethane dyes, metal complex salts of salicylic acid, metal complex salts of benzyl acid, copper phthalocyanine, perylene, quinacridone, azo pigments, metal complex azo dyes, azochrome complexes, etc. Examples include heavy metal-containing acid dyes, calixarene type phenolic condensates, cyclic polysaccharides, resins containing carboxyl groups and / or sulfonyl groups, and the like.
These charge control agents may be used alone or in combination of two or more.

  In the present embodiment, various known internal additives such as an antioxidant used for this type of toner may be used for the toner, if necessary.

[Physical properties of toner]
The volume average particle diameter (D _50v ) of the toner of the exemplary embodiment is preferably 2 μm or more and 10 μm or less, more preferably 3 μm or more and 9 μm or less, and further preferably 4 μm or more and 8 μm or less.
Further, the volume average particle diameter (D _50v ) of the toner base particles in the toner of the exemplary embodiment is preferably 2 μm or more and 10 μm or less, more preferably 3 μm or more and 9 μm or less, and further preferably 4 μm or more and 8 μm or less.
The toner preferably has a narrow particle size distribution, and more specifically, the ratio of the 16% diameter (D _16p ) and the 84% diameter (D _84p ) in _terms of the square root in terms of the smaller number particle size of the toner. (GSDp), that is, GSDp represented by the following formula is preferably 1.40 or less, more preferably 1.31 or less, and particularly preferably 1.27 or less. _{GSDp = {(D 84p) /} (D 16p)} 0.5
If the volume average particle size and GSDp are both in the above ranges, extremely small particles do not exist, and therefore, a decrease in developability due to an excessive charge amount of the small particle size toner is suppressed.

A Coulter Multisizer II type (manufactured by Beckman Coulter, Inc.) can be used to measure the average particle size of particles such as toner and toner base particles. In this case, measurement can be performed using an optimum aperture depending on the particle size level of the particles.
A cumulative distribution is drawn from the smaller diameter side to the particle size range (channel) divided based on the particle size distribution, and the particle size that becomes 16% cumulative is the volume D _16v , the number D _16p , and the cumulative 50%. The particle size to be defined is defined as volume D _50v and number D _50p , and the particle size to be accumulated 84% is defined as volume D _84v and number D _84p . Using these, the volume average particle diameter can be obtained as D _50v, the number average particle size distribution index (GSDp) can be calculated as ^{_{1/2 (D 84p / D 16p)}} .

[Toner Production Method]
In the present exemplary embodiment, the toner manufacturing method is not particularly limited, and may be manufactured by a known method.
For example, after mixing components such as a binder resin, a colorant, an infrared absorber, a release agent, and a charge control agent as necessary, the above materials are melt-kneaded using a kneader, an extruder, etc. The obtained melt-kneaded material is roughly pulverized, then finely pulverized with a jet mill or the like, and a toner particle having a target particle size is obtained by an air classifier; particles obtained by the kneading pulverization method A method of changing the shape by mechanical impact force or thermal energy; emulsifying the binder resin, and forming a dispersion liquid and a dispersion liquid of a colorant, a release agent, and a charge control agent, if necessary. Emulsion aggregation method to obtain toner particles by mixing, aggregating and heat-fusing; monomer for obtaining binder resin, colorant, infrared absorber, release agent, and charge control agent if necessary Suspension polymerization method in which the solution is suspended in an aqueous solvent and polymerized; binder resin, colorant, infrared Absorbents, release agents, and dissolution suspension method or the like for granulating solution such charge control agent is suspended in an aqueous solvent optionally; is used. Further, a production method may be performed in which the toner particles obtained by the above method are used as a core, and further, aggregated particles are attached and heat-fused to give a core-shell structure.
Among these, it is preferable to produce the toner of this embodiment using a kneading and pulverizing method or an emulsion aggregation method.

  A method for externally adding the external additive to the toner base particles is not particularly limited, and a known method can be used. Specifically, for example, a method of adhering to the surface of the toner base particles by a dry method using a blender such as a V blender or a Henschel mixer, a surface after dispersing external additives in a liquid, adding to a toner in a slurry state, and drying the surface Examples of the method of adhering to the toner or the wet method include a method of drying while spraying a slurry on a dry toner.

<Career>
The electrostatic image developer of this embodiment is a two-component developer composed of toner and carrier.
The carrier is a resin-coated carrier having a core and a coating resin layer containing a conductive material and a crosslinkable resin on the surface of the core. By using a crosslinkable resin on the outermost surface, it is possible to suppress the external additive from being embedded in the carrier surface and changing the external additive structure.
Ferrite, magnetite, iron powder, etc. can be used as the material of the magnetic particles serving as the core material.
A carrier having a coating resin layer containing a conductive material on the core material surface is obtained by coating the core material with a resin by a spray drying method, a rotary drying method, an immersion drying method using a universal stirrer, or the like.
Further, the coating resin layer is not limited to a single layer, and may be composed of two or more layers.

The coating resin used to coat the surface of the core material contains a crosslinkable resin, and if necessary, a fluorine resin, an acrylic resin, an epoxy resin, a polyester resin, a fluorine acrylic resin, an acrylic / styrene resin, A silicone resin, a modified silicone resin modified with an acrylic resin, a polyester resin, an epoxy resin, an alkyd resin, a urethane resin, or the like may be included. Moreover, you may add a charge control agent, a resistance control agent, etc. as needed.
Examples of the crosslinkable resin that is a preferable coating resin include polyurethane resin, phenol resin, urea resin, melamine resin, guanamine resin, melamine-urea cocondensation resin, crosslinkable fluororesin, epoxy resin, and crosslinkable silicone resin. It is done.
Among these, as the crosslinkable resin, an epoxy resin and a crosslinkable silicone resin are preferable, and a crosslinkable silicone resin is more preferable. As the crosslinkable silicone resin, a crosslinkable straight silicone resin and a fluorine-modified silicone resin are preferable, and a fluorine-modified silicone resin is more preferable.
Specific examples of conductive materials include metals such as gold, silver and copper; carbon black; conductive metal oxides such as titanium oxide and zinc oxide; titanium oxide, zinc oxide, aluminum borate and titanic acid. And a composite system in which the surface of fine particles of potassium, tin oxide, indium tin oxide or the like is coated with a conductive metal oxide.
The content of the conductive material is preferably 0.5 to 20 parts by weight and more preferably 2 to 18 parts by weight with respect to 100 parts by weight of the coating resin. If it is in the range of 0.5 to 20 parts by weight, the resistance of the carrier is well controlled.

  The total content of the coating resin layer in the carrier is preferably 0.5 parts by weight or more and 10 parts by weight or less, more preferably 1 part by weight or more and 8 parts by weight or less, with respect to 100 parts by weight of the core material, and 1 part by weight or more and 5 parts by weight or less. More preferred are parts by weight or less. When the content of the coating resin layer is 0.5 parts by weight or more, the surface exposure of the core particles is small, and injection of the development electric field can be suppressed. Further, when the content of the coating resin layer is 10 parts by weight or less, the resin powder released from the coating resin layer is small, and the resin powder peeled off in the developer can be suppressed from the initial stage.

  The average film thickness of each coating resin layer is preferably 0.1 μm or more and 10 μm or less, more preferably 0.1 μm or more and 3.0 μm or less, and further preferably 0.1 μm or more and 1.0 μm or less. preferable. When the average film thickness of the coating resin layer is 0.1 μm or more, resistance reduction due to peeling of the coating resin layer does not occur during long-time use, and carrier pulverization can be easily controlled. On the other hand, when the average film thickness of the coating resin layer is 10 μm or less, the time until the saturation charge amount is reached is short.

The average thickness (μm) of the coating resin layer is such that the true specific gravity of the core material is ρ (dimensionless), the volume average particle size of the core material is d (μm), the average specific gravity of the coating resin layer is ρ _C , When the total content of the coating resin layer relative to parts by weight is W _C (parts by weight), it can be determined as in the following formula (A).
Formula (A): Average film thickness (μm) = {[amount of coating resin per carrier (including all additives such as conductive powder) / surface area per carrier]} / average specific gravity of coating resin layer
= {[4 / 3π · (d / 2) ³ · ρ · W _C / 100] / [4π · (d / 2) ² ]} / ρ _C
= (1/600) · (d · ρ · W _C / ρ _C )

  The volume average particle diameter of the carrier is preferably 15 to 60 μm, more preferably 18 to 55 μm, still more preferably 20 to 50 μm, and particularly preferably 22 to 45 μm. It is preferable for the carrier to have a volume average particle size of 15 μm or more because the specific organic particles can be uniformly present in the developer, and image smearing can be stably suppressed. Moreover, it is preferable for the thickness to be 60 μm or less because the specific organic particles can be prevented from adhering to the carrier, and image smearing can be stably suppressed.

In the carrier, when the proportion of particles having a particle size of 22 μm or more and 31 μm or less in the whole developer is wc (wt%) and the proportion of the specific organic particles in the developer is w2 ′ (wt%), the following formula ( 2) is satisfied.
2.0 × 10 ⁻⁴ ≦ w2 ′ / wc ≦ 5.0 × 10 ⁻³ (2)
In the present embodiment, for the carrier particles having a particle size of less than 22 μm, the specific organic particles are stably supplied because the particle size ratio between the specific organic particles and the carrier particles is small and the adhesion between the specific organic particles and the carrier is weak. On the other hand, it is difficult to uniformly supply specific organic particles to toner particles for carrier particles having a particle size of 31 μm or larger, and carrier particles having a particle size of 22 μm or more and 31 μm or less are the most specific organic particles. It is considered that it contributes to the toner. For this reason, it is important what proportion of specific organic particles are present with respect to carrier particles having a particle diameter of 22 μm or more and 31 μm or less.
When w2 ′ / wc is 2.0 × 10 ⁻⁴ or more, an appropriate amount of specific organic particles are developed at the time of development, so that a fixed image is favorably protected. Moreover, it is preferable that it is 5.0 × 10 ⁻³ or less because the specific organic particles present on the carrier surface do not become excessive, so that the fixing property is not hindered and image staining is suppressed.
w2 ′ / wc is more preferably 2.5 × 10 ^{−4 to} 4.5 × 10 ⁻³ , more preferably 3.0 × 10 ^{−4 to} 4.0 × 10 ⁻³ , More preferably, it is 3.5 × 10 ^{−4 to} 3.5 × 10 ⁻³ .

The electrostatic image developer of this embodiment contains a toner and a carrier, and the content of the toner in the developer is preferably 2.0 parts by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the developer. 5 to 16 parts by weight is more preferable, and 3.0 to 14 parts by weight is even more preferable.
It is preferable that the toner content is within the above range because a sufficient image density can be obtained and fog and toner scattering can be prevented.

(Image forming apparatus and image forming method)
The image forming apparatus according to the present embodiment includes an image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the surface of the image carrier, and developing the electrostatic latent image with an electrostatic charge image developer. Developing means for forming a toner image, transfer means for transferring the toner image to the surface of the transfer target, and fixing means (light fixing means) for fixing the toner image transferred to the surface of the transfer target by light fixing; And at least. Further, the electrostatic image developer of this embodiment is used as the electrostatic image developer. The transfer unit may perform transfer two or more times using an intermediate transfer member, and may include a cleaning step and the like as necessary.
The developing unit preferably includes a plurality of developer holders having a peripheral speed of 1,000 mm / s or more, and the electrostatic image developer of the present embodiment is a high-speed photofixing image forming apparatus. The present invention also provides a high-quality image in which image contamination is suppressed.
Examples of the light fixing include flash light, laser, and LED.

The image forming method of the present embodiment includes a charging step for charging the surface of the image carrier, an electrostatic latent image forming step for forming an electrostatic latent image on the surface of the image carrier, and the electrostatic latent image with toner. A developing step of developing with a developer to form a toner image, a transfer step of transferring the toner image to a transfer target, and a fixing step of fixing the transferred toner image to the transfer target by a light fixing method; including. As the developer, the developer of this embodiment is used. In the transfer step, transfer may be performed twice or more using an intermediate transfer member, and a cleaning step may be included as necessary.
The peripheral speed of the developer holder that holds the developer is preferably 1,000 mm / s or more, and the electrostatic charge image developer of this embodiment is used for image staining in a high-speed image fixing method. It is intended to provide a high-quality image with suppressed image quality.

  The peripheral speed of the developing holder is preferably 1,000 mm / s or more, more preferably 1,000 to 3,000 mm / s, and further preferably 1,000 to 2,500 mm / s. preferable. When the peripheral speed is within the above range, both high-speed image creation and high-quality images can be achieved.

When an electrophotographic photosensitive member is used as an image carrier for forming a toner image on a recording medium, for example, it can be performed as follows. Regarding each step in the image forming method and each means in the image forming apparatus, for example, refer to Japanese Patent Laid-Open Nos. 56-40868 and 469-91231.
First, the surface of the electrophotographic photosensitive member is charged by a corotron charger, a contact charger or the like and then exposed to form an electrostatic charge image. Next, the toner is attached to the electrostatic latent image in contact with or in proximity to a developing roll having a developer layer formed on the surface, thereby forming a toner image on the electrophotographic photosensitive member. The formed toner image is transferred onto the surface of a recording medium such as paper using a corotron charger or the like. Further, the toner image transferred to the surface of the recording medium is fixed by a fixing device, and an image is formed on the recording medium.

  As the electrophotographic photoreceptor, generally, an inorganic photoreceptor such as amorphous silicon or selenium, or an organic photoreceptor using polysilane, phthalocyanine or the like as a charge generation material or a charge transport material is used. A photoreceptor is preferred.

<Light fixing means>
The light fixing unit is not limited as long as it can be fixed by light. When the electrostatic charge image developer of this embodiment is used, it is preferable to use a light fixing unit (flash fixing unit).

Examples of the light source used in the optical fixing device include ordinary halogen lamps, mercury lamps, flash lamps, and infrared lasers. A flash lamp is preferable, and energy is saved by fixing the flash lamp instantaneously. Emission energy of the flash lamp is more preferably is preferably 1.0 J / cm ² or more 7.0J / cm ² or less, 2J / cm ² or more 5 J / cm ² or less.

Here, the emission energy per unit area of the flash light indicating the lamp intensity of xenon is expressed by the following formula (3).
S = ((1/2) × C × V2) / (u × L) × (n × f) (3)

In the above formula (3), n is the number of lamps that emit light at once (f), f is the lighting frequency (Hz), V is the input voltage (V), C is the capacitor capacity (F), u is the process transport speed (cm) / S), L represents the effective light emission width of the flash lamp (usually the maximum paper width, cm), and S represents the energy density (J / cm ² ).

The light fixing method is preferably a delay method in which a plurality of flash lamps emit light with a time difference. This delay system is a system in which a plurality of flash lamps are arranged, each lamp is delayed by about 0.01 ms or more and 100 ms or less to emit light, and an overlapping portion is illuminated a plurality of times. As a result, since the light energy is not supplied to the toner image in one light emission but supplied separately, the fixing conditions are relaxed, and both void resistance and fixing property can be achieved.
Here, when flash emission is performed on the toner a plurality of times, the emission energy of the flash lamp indicates the total amount of emission energy given to the unit area for each emission.

In the present embodiment, the number of flash lamps is preferably 1 or more and 20 or less, and more preferably 2 or more and 10 or less. The time difference between the plurality of flash lamps is preferably 0.1 msec or more and 20 msec or less, and more preferably 1 msec or more and 3 msec or less.
Furthermore, once emission energy of light emitted in one flash lamp, it is preferably, 0.4 J / cm ² or more 0.8 J / cm ² or less is 0.1 J / cm ² or more 1 J / cm ² or less More preferable.

Hereinafter, an example of the image forming apparatus according to the present exemplary embodiment will be described with reference to the drawings.
FIG. 1 is a schematic diagram illustrating an example of an image forming apparatus according to the present embodiment. FIG. 1 shows a toner image formed by toner obtained by adding black to three colors of cyan, magenta, and yellow.

  In FIG. 1, 1a, 1b, 1c and 1d are charging means, 2a, 2b, 2c and 2d are exposure means, 3a, 3b, 3c and 3d are electrostatic image holders (photoconductors), 4a, 4b, 4c and 4d is developing means, 10 is recording paper (recording medium) fed out from the roll medium 15 in the direction of the arrow, 20 is a cyan developing unit, 30 is a magenta developing unit, 40 is a yellow developing unit, 50 is a black developing unit, 70a, 70b , 70c and 70d are transfer means (transfer rolls), 71 and 72 are rolls, 80 is a transfer voltage supply means, and 90 is a light fixing means.

  The image forming apparatus shown in FIG. 1 includes a developing unit (toner image forming unit) indicated by reference numerals 20, 30, 40, and 50 including a charging unit, an exposure unit, a photoconductor, and a developing unit, and a recording paper 10. Rolls 71 and 72 arranged in contact with each other and transporting the recording paper 10 and transfer means (transfer roll) arranged so as to contact with the opposite side of the recording paper 10 so as to press the photoreceptor of each developing unit. 70a, 70b, 70c, 70d, transfer voltage supply means 80 for supplying voltage to these three transfer rolls, and the photoreceptor of the recording paper 10 that passes through the pressure contact portion between the photoreceptor and the transfer roll in the direction of the arrow in the figure. And a light fixing means (light fixing device) 90 for irradiating light to the side in contact with the light.

  The cyan developing unit 20 has a configuration in which a charging unit 1a, an exposing unit 2a, and a developing unit 4a are arranged around the photoreceptor 3a in a clockwise direction. Further, a transfer roll 70a is disposed opposite to the recording sheet 10 so as to be in contact with the surface of the photosensitive member 3a between the position where the developing unit 4a is arranged on the photosensitive member 3a and the position where the charging unit 1a is rotated clockwise.

  The above configuration is the same for the developing units of other colors. In the image forming apparatus of the present embodiment, the developer containing the cyan toner is stored in the developing unit 4a of the cyan developing unit 20, and the light corresponding to each color is supplied to the developing units of the other developing units. A fixing magenta toner is stored.

Next, image formation using this image forming apparatus will be described.
First, in the black developing unit 50, the surface of the photoreceptor 3d is charged by the charging unit 1d while rotating the photoreceptor 3d in the clockwise direction. Next, the surface of the charged photoreceptor 3d is exposed by the exposure means 2d, whereby a latent image corresponding to the black component image of the original image to be copied is formed on the surface of the photoreceptor 3d. Further, the black toner stored in the developing means 4d is applied on the latent image to develop it to form a black toner image. In the yellow developing unit 40, the magenta developing unit 30, and the cyan developing unit 20, a process similar to this is performed, and a toner image of each color is formed on the surface of the photosensitive member of the developing unit.

The toner images of the respective colors formed on the surface of the photoreceptor are sequentially transferred onto the recording paper 10 conveyed in the direction of the arrow by the action of the transfer potential by the transfer rolls 70a, 70b, 70c and 70d, and correspond to the original image information. In this way, the toner images are laminated on the surface of the recording paper 10 to form a color toner image in which cyan, magenta, and yellow are laminated in this order from the top layer.
Note that when the toner image is transferred using the magenta toner, the fixing property of the toner is excellent even if the conveyance speed of the recording medium is 1000 mm / second or more.

  Next, the laminated toner image on the recording paper 10 is conveyed to the optical fixing unit 90, where it is irradiated with light from the optical fixing unit 90, melted, and optically fixed on the recording paper 10 to form a color image. It is formed.

<Developer cartridge>
The developer cartridge of the present embodiment is detachable from an image forming apparatus main body provided with a light fixing unit that irradiates and fixes a toner image on the surface of a recording medium, and stores the electrostatic image developer. .
The developer cartridge only needs to include at least one of the developing units 4a, 4b, 4c, and 4d in the color image forming apparatus, and the developing units 20, 30, 40, and 50 can also be developer cartridges. .

  The developer of this embodiment is suitably used for various applications such as newspapers, service bureaus, barcode printing, label printing, tag printing, Carlson type or ion flow type printers and copying, and at low cost. Products that exhibit good photofixability are provided.

  Hereinafter, although this embodiment is described in detail with examples, this embodiment is not limited in any way. In the following description, “parts” and “%” indicate “parts by weight” and “% by weight” unless otherwise specified.

(Measuring method)
<Number average primary particle size of silica particles>
The particle size of 500 silica particles was measured from an image observed at a magnification of 100,000 on a scanning electron microscope image, and the average primary particle size was determined by number average.

<Volume average particle diameter of organic particles>
The volume average particle diameter was measured using a laser diffraction / scattering particle size distribution measuring apparatus (HORIBA LA-920).

<Method of measuring endothermic peak temperature and glass transition temperature of resin>
As the glass transition temperature (Tg) of the resin, a differential scanning calorimeter (manufactured by Shimadzu Corporation: DSC-60A) can be used in accordance with ASTM D3418. For the sample, an aluminum pan was used, an empty pan was set for control, the temperature was raised at a rate of temperature increase of 10 ° C./min, held at 200 ° C. for 5 minutes, and liquid nitrogen was used from 200 ° C. to 0 ° C. The temperature is lowered at 10 ° C./min, held at 0 ° C. for 5 minutes, and then heated again from 0 ° C. to 200 ° C. at 10 ° C./min. Analysis is performed from the endothermic curve during the second temperature increase, and the onset temperature is set to Tg for the amorphous polyester resin, and the endothermic peak temperature is set from the maximum peak for the crystalline polyester resin.

<Method for measuring weight average molecular weight and molecular weight distribution of resin>
In the present embodiment, the molecular weight of the binder resin or the like is determined under the following conditions. GPC uses “HLC-8120GPC, SC-8020 (manufactured by Tosoh Corp.)”, column uses “TSKgel, SuperHM-H (Tosoh Corp. 6.0 mmID × 15 cm)”, two eluents THF (tetrahydrofuran) was used. As experimental conditions, an experiment was performed using a sample concentration of 0.5%, a flow rate of 0.6 ml / min, a sample injection amount of 10 μl, a measurement temperature of 40 ° C., and an IR detector. In addition, the calibration curve is “polystylen standard sample TSK standard” manufactured by Tosoh Corporation: “A-500”, “F-1”, “F-10”, “F-80”, “F-380”, “A” -2500 "," F-4 "," F-40 "," F-128 ", and" F-700 ".

<Method of measuring volume average particle diameter of toner>
The volume average particle diameter of the toner was measured using a Coulter Multisizer II (manufactured by Beckman-Coulter). As the electrolytic solution, ISOTON-II (manufactured by Beckman-Coulter) was used.
As a measuring method, first, 0.5 mg to 50 mg of a measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate as a dispersant, and this is added to 100 ml to 150 ml of the electrolytic solution. Added. The electrolytic solution in which the measurement sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute. Using the Coulter Multisizer II type, an aperture having an aperture diameter of 100 μm is used. The particle size distribution of the following range of particles was measured. The number of particles to be measured was 50,000.
For the measured particle size distribution, a cumulative distribution is drawn from the smaller diameter side with respect to the divided particle size range (channel), and the particle size at which 50% is accumulated is defined as the volume average particle size.

<Measurement method of volume average particle diameter of carrier>
The volume average particle diameter of the carrier was measured using a laser diffraction / scattering particle size distribution analyzer (LS Particle Size Analyzer: LS13 320, manufactured by Beckman Coulter, Inc.). For the particle size range (channel) obtained by dividing the obtained particle size distribution, the volume cumulative distribution was subtracted from the small particle size side, and the particle size at 50% cumulative was taken as the volume average particle size.
Further, from the obtained particle size distribution, the ratio of particles having a particle size of 22 μm or more and 31 μm or less was determined.

(Preparation of silica particles)
<Preparation of silica particles 1>
While stirring gas phase method silica having a number average particle diameter of 12 nm (product name: Aerosil 200, manufactured by Nippon Aerosil Co., Ltd.) under a nitrogen atmosphere, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane ( Shin-Etsu Chemical Co., Ltd., trade name: KBM-603) was added dropwise, and the mixture was heated and mixed and stirred at 150 ° C. for 90 minutes to remove volatile components and then cooled to obtain aminosilane surface-treated silica particles 1.

<Preparation of silica particles 2>
Distilled and purified methyltrimethoxysilane was heated, nitrogen gas was bubbled, and methyltrimethoxysilane was introduced into an oxyhydrogen flame burner with a stream of nitrogen gas, and burned and decomposed in the oxyhydrogen flame. The amounts of methyltrimethoxysilane, oxygen gas, hydrogen gas, and nitrogen gas were adjusted to obtain gas phase method silica particles having a primary particle number average particle size of 5 nm. While stirring the obtained silica particles in a nitrogen atmosphere, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-603) was added dropwise, The mixture was stirred and heated at 150 ° C. for 90 minutes to remove volatile components and then cooled to obtain aminosilane surface-treated silica particles 2.

<Preparation of silica particles 3>
Distilled and purified methyltrimethoxysilane was heated, nitrogen gas was bubbled, and methyltrimethoxysilane was introduced into an oxyhydrogen flame burner with a stream of nitrogen gas, and burned and decomposed in the oxyhydrogen flame. The amounts of methyltrimethoxysilane, oxygen gas, hydrogen gas and nitrogen gas were adjusted to obtain gas phase method silica particles having a primary particle number average particle size of 6 nm. While stirring the obtained silica particles in a nitrogen atmosphere, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-603) was added dropwise, The mixture was heated and mixed and stirred at 150 ° C. for 90 minutes to remove volatile components and then cooled to obtain aminosilane surface-treated silica particles 3.

<Preparation of silica particles 4>
Distilled and purified methyltrimethoxysilane was heated, nitrogen gas was bubbled, and methyltrimethoxysilane was introduced into an oxyhydrogen flame burner with a stream of nitrogen gas, and burned and decomposed in the oxyhydrogen flame. The amounts of methyltrimethoxysilane, oxygen gas, hydrogen gas, and nitrogen gas were adjusted to obtain gas phase method silica particles having a primary particle number average particle size of 17 nm. While stirring the obtained silica particles in a nitrogen atmosphere, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-603) was added dropwise, The mixture was stirred and heated at 150 ° C. for 90 minutes to remove volatile components and then cooled to obtain aminosilane surface-treated silica particles 4.

<Preparation of silica particles 5>
Distilled and purified methyltrimethoxysilane was heated, nitrogen gas was bubbled, and methyltrimethoxysilane was introduced into an oxyhydrogen flame burner with a stream of nitrogen gas, and burned and decomposed in the oxyhydrogen flame. The amounts of methyltrimethoxysilane, oxygen gas, hydrogen gas and nitrogen gas were adjusted to obtain gas phase method silica particles having a primary particle number average particle size of 19 nm. While stirring the obtained silica particles in a nitrogen atmosphere, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-603) was added dropwise, The mixture was heated and mixed and stirred at 150 ° C. for 90 minutes to remove volatile components and then cooled to obtain aminosilane surface-treated silica particles 5.

<Preparation of silica particles 6>
Silica particles 6 were obtained by vapor-phase method silica (trade name: R974, manufactured by Nippon Aerosil Co., Ltd.) having a number average particle diameter of 12 nm and surface-treated with dimethyldichlorosilane.

<Preparation of silica particles 7>
Distilled and purified methyltrimethoxysilane was heated, nitrogen gas was bubbled, and methyltrimethoxysilane was introduced into an oxyhydrogen flame burner with a stream of nitrogen gas, and burned and decomposed in the oxyhydrogen flame. The amounts of methyltrimethoxysilane, oxygen gas, hydrogen gas, and nitrogen gas were adjusted to obtain gas phase method silica particles having a primary particle number average particle size of 4 nm. While stirring the obtained silica particles in a nitrogen atmosphere, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-603) was added dropwise, The mixture was stirred and heated at 150 ° C. for 90 minutes to remove volatile components and then cooled to obtain silica particles 7.

<Preparation of silica particles 8>
Distilled and purified methyltrimethoxysilane was heated, nitrogen gas was bubbled, and methyltrimethoxysilane was introduced into an oxyhydrogen flame burner with a stream of nitrogen gas, and burned and decomposed in the oxyhydrogen flame. The amounts of methyltrimethoxysilane, oxygen gas, hydrogen gas, and nitrogen gas were adjusted to obtain gas phase method silica particles having a primary particle number average particle size of 22 nm. While stirring the obtained silica particles in a nitrogen atmosphere, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-603) was added dropwise, The mixture was stirred and heated at 150 ° C. for 90 minutes to remove volatile components, and then cooled to obtain silica particles 8.

(Production of organic particles)
<Preparation of organic particles 1>
A zinc sulfate aqueous solution was dropped into an aqueous sodium stearate solution maintained at a temperature of 80 ° C., and the mixture was further stirred for 1 hour to obtain a zinc stearate slurry. The obtained slurry was filtered, washed twice with water, and the cake was further dried in a hot air dryer at 110 ° C. for 12 hours. The obtained dried cake was pulverized with a counter jet mill AFG100 (manufactured by Hosokawa Micron Co., Ltd.) and then classified with an elbow jet classifier EJ-LABO (manufactured by Nippon Steel Mining Co., Ltd.). The zinc stearate particles were obtained and designated as organic particles 1. The endothermic peak of the organic particles 1 by differential scanning calorimetry was 120 ° C.

<Preparation of organic particles 2>
After pulverizing octacosanoic acid (chemical formula; CH ₃ (CH ₂ ) ₂₆ COOH) solids with a counter jet mill AFG100 (manufactured by Hosokawa Micron Corporation), an elbow jet classifier EJ-LABO (manufactured by Nippon Steel Mining Co., Ltd.) To obtain organic particles 2 having a volume average particle diameter of 7.9 μm. The endothermic peak of the organic particles 2 by differential scanning calorimetry was 93 ° C.

<Preparation of organic particles 3>
1-Triacontanol (chemical formula; CH ₃ (CH ₂ ) ₂₉ OH) solid material was pulverized with a counter jet mill AFG100 (manufactured by Hosokawa Micron Corporation), and then an elbow jet classifier EJ-LABO (Nittetsu Mining Co., Ltd.) )) To obtain organic particles 3 having a volume average particle size of 8.5 μm. The endothermic peak of the organic particles 3 by differential scanning calorimetry was 86 ° C.

<Preparation of organic particles 4>
In the production of the organic particles 3, the conditions of pulverization and classification were adjusted to obtain organic particles 4 having a volume average particle size of 0.5 μm.

<Preparation of organic particles 5>
In the production of the organic particles 3, the conditions of pulverization and classification were adjusted to obtain organic particles 5 having a volume average particle size of 0.7 μm.

<Preparation of organic particles 6>
In the production of the organic particles 3, the conditions of pulverization and classification were adjusted to obtain organic particles 6 having a volume average particle diameter of 11.5 μm.

<Preparation of organic particles 7>
In the production of the organic particles 3, the conditions of pulverization and classification were adjusted to obtain organic particles 7 having a volume average particle size of 14.9 μm.

<Preparation of organic particles 8>
In the production of the organic particles 3, the conditions of pulverization and classification were adjusted to obtain organic particles 8 having a volume average particle size of 0.4 μm.

<Preparation of organic particles 9>
In the production of the organic particles 3, the conditions of pulverization and classification were adjusted to obtain organic particles 9 having a volume average particle size of 15.8 μm.

<Preparation of organic particles 10>
A dry cake of a calcium stearate slurry was obtained in the same manner except that the aqueous zinc sulfate solution was changed to an aqueous calcium chloride solution in the production of the organic particles 1. The obtained dried cake was pulverized with a counter jet mill AFG100 (manufactured by Hosokawa Micron Co., Ltd.) and then classified with an elbow jet classifier EJ-LABO (manufactured by Nippon Steel Mining Co., Ltd.), and a volume average particle size of 5.6 μm. The calcium stearate particles were obtained, and this was designated as organic particles 10. The endothermic peak of the organic particles 10 by differential scanning calorimetry was 148 ° C.

<Preparation of organic particles 11>
Palmitic acid (chemical formula; CH ₃ (CH ₂ ) ₁₄ COOH) solids were pulverized with a counter jet mill AFG100 (manufactured by Hosokawa Micron Corporation) and then elbow jet classifier EJ-LABO (manufactured by Nippon Steel Mining Co., Ltd.) The organic particles 11 having a volume average particle diameter of 6.5 μm were obtained. The endothermic peak of the organic particles 11 measured by differential scanning calorimetry was 63 ° C.

<Preparation of Amorphous Polyester Resin A>
Bisphenol A ethylene oxide 2 mol adduct: 15 mol%
Bisphenol A propylene oxide 2 mol adduct: 35 mol%
Terephthalic acid: 50 mol%
A monomer equipped with the above composition ratio is charged into a flask equipped with a stirrer, nitrogen introduction tube, temperature sensor, and rectifying column, and the temperature is raised to 190 ° C. over 1 hour, and the reaction system is stirred uniformly. After confirming the above, 1.0% by weight of dibutyltin oxide was added. Further, while distilling off the generated water, it took 6 hours from the same temperature to increase the temperature to 240 ° C., and continued the dehydration condensation reaction at 240 ° C. for another 2.5 hours, with a glass transition temperature of 62 ° C. and a weight average molecular weight. Amorphous polyester resin A having (Mw) 16,000 was obtained.

<Preparation of crystalline polyester resin A>
1,900 parts by weight of sebacic acid, 1,500 parts by weight of ethylene glycol, 60 parts by weight of sodium isophthalate-5-sulfonate and 0.2 parts by weight of dibutyltin oxide were mixed in a flask and heated to 240 ° C. in a reduced pressure atmosphere. Then, dehydration condensation was performed for 6 hours to obtain a crystalline polyester resin A. It was 28,000 when the weight average molecular weight (Mw) of the obtained crystalline polyester resin A was measured by the above-mentioned method. Further, the endothermic peak temperature Tm of the obtained crystalline polyester resin A was measured with a differential scanning calorimeter (DSC) by the above-described measuring method, and found to be 75 ° C.

<Preparation of crystalline polyester resin B>
1,800 parts by weight of sebacic acid, 950 parts by weight of 1,5-pentanediol, and 1.13 parts by weight of dibutyltin oxide were mixed in a flask, heated to 240 ° C. in a reduced pressure atmosphere, dehydrated and condensed for 6 hours, and crystalline. Polyester resin B was obtained. The obtained crystalline polyester resin B had a weight average molecular weight (Mw) of 22,000 and an endothermic peak temperature Tm of 53 ° C.

<Preparation of crystalline polyester resin C>
1,800 parts by weight of succinic acid, 1,400 parts by weight of 1,4-butanediol, 53.8 parts by weight of sodium dimethyl 5-sulfonate and 1.13 parts by weight of dibutyltin oxide were mixed in a flask, and a reduced pressure atmosphere Then, the mixture was heated to 240 ° C. and dehydrated and condensed for 6 hours to obtain a crystalline polyester resin C. The obtained crystalline polyester resin C had a weight average molecular weight (Mw) of 25,000 and an endothermic peak temperature Tm of 123 ° C.

Example 1
<Preparation of Toner 1>
Amorphous polyester resin A 79 parts by weight Crystalline polyester resin A 7 parts by weight Carbon black (trade name Regal 330, manufactured by Cabot Corporation) 6 parts by weight Polyethylene wax (product name: Polywax 500, manufactured by Toyo ADR Co., Ltd.) 8 parts by weight The above composition is powder-mixed with a Henschel mixer, heat-kneaded with an extruder with a set temperature of 100 ° C., cooled, coarsely pulverized, finely pulverized and classified, and toner base particles having a volume average particle diameter D50 of 6.4 μm 1 was obtained.
Further, 100 parts by weight of toner base particles 1, 1.4 parts by weight of silica particles 1 and 0.4 parts by weight of organic particles 1 were mixed with a Henschel mixer to obtain black toner 1.

<Preparation of carrier 1>
Appropriate amounts of each raw material are blended so that it is 30 mol% in terms of MnO, 9.5 mol% in terms of MgO, 60 mol% in terms of Fe ₂ O ₃ , and 0.5 mol% in terms of SrO, water is added, and the wet ball mill is used for 10 hours. After pulverizing, mixing, drying and holding at 900 ° C. for 4 hours, the slurry that had been pulverized by wet ball mill for 24 hours was granulated and dried, and held at 1,250 ° C. in an atmosphere of 2% oxygen concentration for 6 hours Then, it grind | pulverized and particle size adjustment was performed and the manganese-magnesium-strontium ferrite particle A was obtained.
Dimethyl silicone resin containing trifluoropropyl group (SR-2410, Toray
200 parts by weight of Dow Corning Co., Ltd. in terms of solid content, dissolved in 867 parts by weight of toluene solvent, and conductive carbon black (Vulcan XC72, manufactured by Cabot Corporation) is 15% by weight based on the resin solid content. 2 parts by weight of an aluminum curing catalyst (aluminum-di-n-butoxide monoethyl acetoacetate) was added and dispersed in a pearl mill to obtain a carrier coating solution.
Using 100 parts of manganese-magnesium-strontium ferrite particles A, apply the above-mentioned carbon black-dispersed inner layer forming solution using a fluidized bed (spray dry) coating device so that the silicone resin is 2.2 parts in solids. Then, after drying at 100 ° C., baking was carried out at 270 ° C. for 1 hour, followed by crushing treatment and 30 minutes of post-treatment using a vibration type mill to obtain carrier 1.
The volume average particle diameter of the carrier 1 was 38 μm, and the ratio of 22 to 31 μm or less in the carrier particles was 20% by weight.

(Preparation of developer 1)
7 parts of toner 1 and 93 parts of carrier 1 were mixed in a V blender to obtain black developer 1. At this time, w1 / w2 = 3.5, w2 ′ = 2.75 × 10 ⁻² wt%, and wc = 18.6 wt%.
Moreover, it was w2 '/ wc = 1.5 * 10 < ^-3 >.

<Evaluation method>
Image quality evaluation was performed using a remodeling machine obtained by modifying the 650J Continuous Feeding System manufactured by Fuji Xerox Co., Ltd. so that the peripheral speed of the developer holder was variable. The peripheral speed of the developing roll was set to 1,100 mm / s.
A line image (an image in which fine lines are arranged in a grid) was printed in a high-humidity environment with a temperature of 25 ° C. and a humidity of 80% on the modified machine, and 10,000 sheets of A4 equivalent images were printed. Place a weight (equivalent to a load of 80 g / cm ² ) on a thin line image after printing 10,000 sheets and rub the image 10 times with the weight. Judged.
A: Image stains and thin line defects are not confirmed by visual observation, and stains cannot be confirmed even on white paper wrapped around a weight.
○: Image stains and thin line defects cannot be confirmed by visual observation, but slight stains can be confirmed on the white paper wrapped around the weight.
(Triangle | delta): It is an acceptable level although the defect | deletion of a fine line or image stain | pollution | contamination can be confirmed very slightly visually.
X: Fine line defects or image stains can be clearly confirmed by visual observation, and are at an unacceptable level.
The evaluation results are shown in Table 1.

(Example 2)
<Preparation of Toner 2>
A black toner 2 was obtained in the same manner as in Example 1 except that the organic particles 1 were changed to the organic particles 2.
<Preparation of Developer 2>
7 parts of toner 2 and 93 parts of carrier 1 were mixed in a V blender to obtain black developer 2. At this time, w1 / w2 = 3.5 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Example 3)
<Preparation of Toner 3>
A black toner 3 was obtained in the same manner as in Example 1 except that the organic particles 1 were changed to the organic particles 3.
<Preparation of Developer 3>
7 parts of toner 3 and 93 parts of carrier 1 were mixed in a V blender to obtain black developer 3. At this time, w1 / w2 = 3.5 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

Example 4
<Preparation of Toner 4>
Amorphous polyester resin A 79 parts by weight Crystalline polyester resin B 7 parts by weight Carbon black (manufactured by Cabot, trade name Regal 330) 6 parts by weight Polyethylene wax (manufactured by Toyo Adre Co., Ltd., trade name polywax 500) 8 parts by weight The above composition is powder-mixed with a Henschel mixer, heat-kneaded with an extruder with a set temperature of 100 ° C., cooled, coarsely pulverized, finely pulverized and classified, and toner base particles having a volume average particle diameter D50 of 6.4 μm 2 was obtained.
Further, 100 parts by weight of toner base particles 2, 1.4 parts by weight of silica particles 1 and 0.4 parts by weight of organic particles 1 were mixed by a Henschel mixer to obtain black toner 4.

<Preparation of Developer 4>
7 parts of toner 4 and 93 parts of carrier 1 were mixed in a V blender to obtain black developer 4. At this time, w1 / w2 = 3.5 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Example 5)
<Preparation of Toner 5>
Amorphous polyester resin A 79 parts by weight Crystalline polyester resin C 7 parts by weight Carbon black (manufactured by Cabot, trade name Regal 330) 6 parts by weight Polyethylene wax (manufactured by Toyo ADR Co., Ltd., trade name polywax 500) 8 parts by weight The above composition is powder-mixed with a Henschel mixer, heat-kneaded with an extruder with a set temperature of 100 ° C., cooled, coarsely pulverized, finely pulverized and classified, and toner base particles having a volume average particle diameter D50 of 6.4 μm 3 was obtained.
Further, 100 parts by weight of toner base particles 3, 1.4 parts by weight of silica particles 1 and 0.4 parts by weight of organic particles 1 were mixed with a Henschel mixer to obtain black toner 5.

<Preparation of Developer 5>
7 parts of toner 5 and 93 parts of carrier 1 were mixed in a V blender to obtain black developer 5. At this time, w1 / w2 = 3.5 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Example 6)
<Preparation of Toner 6>
100 parts by weight of toner base particles 1 obtained in Example 1, 0.8 part by weight of silica particles 1 and 0.8 parts by weight of organic particles 1 were mixed with a Henschel mixer to obtain black toner 6.
<Preparation of developer 6>
7 parts of toner 6 and 193 parts of carrier 1 were mixed in a V blender to obtain black developer 6. At this time, w1 / w2 = 1.0 and w2 ′ / wc = 3.0 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Example 7)
<Preparation of Toner 7>
100 parts by weight of toner base particles 1 obtained in Example 1, 1.1 parts by weight of silica particles 1 and 0.7 parts by weight of organic particles 1 were mixed with a Henschel mixer to obtain black toner 7.
<Preparation of developer 7>
7 parts of toner 7 and 93 parts of carrier 1 were mixed in a V blender to obtain black developer 7. At this time, w1 / w2 = 1.6 and w2 ′ / wc = 2.6 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Example 8)
<Preparation of Toner 8>
100 parts by weight of toner base particles 1 obtained in Example 1, 2.0 parts by weight of silica particles 1 and 0.2 parts by weight of organic particles 1 were mixed with a Henschel mixer to obtain black toner 8.
<Preparation of developer 8>
7 parts of toner 8 and 193 parts of carrier 1 were mixed in a V blender to obtain black developer 8. At this time, w1 / w2 = 10.0 and w2 ′ / wc = 7.4 × 10 ⁻⁴ . The evaluation results are shown in Table 1.

Example 9
<Preparation of Toner 9>
100 parts by weight of toner base particles 1 obtained in Example 1, 1.6 parts by weight of silica particles 1 and 0.2 parts by weight of organic particles 1 were mixed with a Henschel mixer to obtain black toner 9.
<Preparation of developer 9>
7 parts of toner 9 and 93 parts of carrier 1 were mixed in a V blender to obtain black developer 9. At this time, w1 / w2 = 8.0 and w2 ′ / wc = 7.4 × 10 ⁻⁴ . The evaluation results are shown in Table 1.

(Example 10)
<Preparation of Toner 10>
100 parts by weight of toner base particles 1 obtained in Example 1, 0.6 part by weight of silica particles 1 and 0.1 part by weight of organic particles 1 were mixed with a Henschel mixer to obtain black toner 10.
<Production of Carrier 2>
In the same manner except that the particle size distribution was adjusted in the production of the carrier 1, a carrier 2 having a volume average particle diameter of 34 μm and a carrier particle having a ratio of 22 to 31 μm or less was 31% by weight.
<Preparation of Developer 10>
6 parts of toner 10 and 94 parts of carrier 2 were mixed in a V blender to obtain black developer 10. At this time, w1 / w2 = 6.0 and w2 ′ / wc = 2.0 × 10 ⁻⁴ . The evaluation results are shown in Table 1.

(Example 11)
<Preparation of carrier 3>
In the same manner except that the particle size distribution was adjusted in the production of the carrier 1, a carrier 3 having a volume average particle size of 33 μm and a carrier particle having a ratio of 22 to 31 μm or less was 34% by weight.
<Preparation of Developer 11>
8 parts of toner 10 and 92 parts of carrier 3 were mixed in a V blender to obtain a black developer 11. At this time, w1 / w2 = 6.0 and w2 ′ / wc = 2.5 × 10 ⁻⁴ . The evaluation results are shown in Table 1.

(Example 12)
<Preparation of Toner 11>
100 parts by weight of toner base particles 1 obtained in Example 1, 2.1 parts by weight of silica particles 1 and 0.9 parts by weight of organic particles 1 were mixed with a Henschel mixer to obtain black toner 11.
<Preparation of carrier 4>
In the same manner except that the particle size distribution was adjusted in the production of the carrier 1, a carrier 4 having a volume average particle size of 42 μm and a carrier particle having a ratio of 22 to 31 μm or less was 12% by weight.
<Preparation of Developer 12>
6.4 parts of toner 11 and 95.6 parts of carrier 4 were mixed in a V blender to obtain black developer 12. At this time, w1 / w2 = 2.3 and w2 ′ / wc = 5.0 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Example 13)
<Preparation of Toner 12>
100 parts by weight of toner base particles 1 obtained in Example 1, 2.0 parts by weight of silica particles 1 and 0.8 parts by weight of organic particles 1 were mixed with a Henschel mixer to obtain black toner 12.
<Preparation of developer 13>
Black developer 13 was obtained by mixing 6.4 parts of toner 12 and 95.6 parts of carrier 4 using a V blender. At this time, w1 / w2 = 2.5 and w2 ′ / wc = 4.4 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Example 14)
<Preparation of Toner 13>
A black toner 13 was obtained in the same manner as in Example 1 except that the silica particles 1 were changed to the silica particles 2.
<Preparation of Developer 14>
7 parts of toner 13 and 193 parts of carrier 1 were mixed in a V blender to obtain black developer 14. At this time, w1 / w2 = 3.5 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Example 15)
<Preparation of Toner 14>
A black toner 14 was obtained in the same manner as in Example 1 except that the silica particles 1 were changed to the silica particles 3.
<Preparation of developer 15>
7 parts of toner 14 and 193 parts of carrier 1 were mixed in a V blender to obtain black developer 15. At this time, w1 / w2 = 3.5 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Example 16)
<Preparation of Toner 15>
A black toner 15 was obtained in the same manner except that the silica particles 1 were changed to the silica particles 4 in Example 1.
<Preparation of Developer 16>
7 parts of toner 15 and 193 parts of carrier 1 were mixed in a V blender to obtain black developer 16. At this time, w1 / w2 = 3.5 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Example 17)
<Preparation of Toner 16>
A black toner 16 was obtained in the same manner as in Example 1 except that the silica particles 1 were changed to the silica particles 5.
<Preparation of Developer 17>
7 parts of toner 16 and 193 parts of carrier 1 were mixed in a V blender to obtain black developer 17. At this time, w1 / w2 = 3.5 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Example 18)
<Preparation of Toner 17>
A black toner 17 was obtained in the same manner except that the organic particles 1 were changed to the organic particles 4 in Example 1.
<Preparation of Developer 18>
7 parts of toner 17 and 193 parts of carrier 1 were mixed in a V blender to obtain black developer 18. At this time, w1 / w2 = 3.5 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Example 19)
<Preparation of Toner 18>
A black toner 18 was obtained in the same manner except that the organic particles 1 were changed to the organic particles 5 in Example 1.
<Preparation of Developer 19>
7 parts of toner 187 and 193 parts of carrier 1 were mixed in a V blender to obtain black developer 19. At this time, w1 / w2 = 3.5 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Example 20)
<Preparation of Toner 19>
A black toner 19 was obtained in the same manner as in Example 1 except that the organic particles 1 were changed to the organic particles 6.
<Preparation of Developer 20>
197 parts of toner and 193 parts of carrier 1 were mixed in a V blender to obtain a black developer 20. At this time, w1 / w2 = 3.5 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Example 21)
<Preparation of Toner 20>
A black toner 20 was obtained in the same manner except that the organic particles 1 were changed to the organic particles 7 in Example 1.
<Preparation of Developer 21>
7 parts of toner 20 and 193 parts of carrier 1 were mixed in a V blender to obtain a black developer 21. At this time, w1 / w2 = 3.5 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Comparative Example 1)
<Preparation of Toner 21>
100 parts by weight of toner base particles 1 obtained in Example 1 and 1.4 parts by weight of silica particles 1 were mixed using a Henschel mixer to obtain black toner 21.
<Preparation of Developer 22>
7 parts of toner 21 and 193 parts of carrier 1 were mixed in a V blender to obtain black developer 22. At this time, w1 / w2 = ∞ and w2 ′ / wc = 0. The evaluation results are shown in Table 1.

(Comparative Example 2)
<Preparation of Toner 22>
A black toner 22 was obtained in the same manner as in Example 1 except that the silica particles 1 were changed to titania particles (manufactured by Teika Co., Ltd .; trade name JMT-150ANO; number average particle size 15 nm).
<Preparation of Developer 23>
7 parts of toner 22 and 193 parts of carrier 1 were mixed in a V blender to obtain black developer 23. At this time, w1 / w2 = 0 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Comparative Example 3)
<Preparation of Toner 23>
A black toner 23 was obtained in the same manner as in Example 1 except that the silica particles 1 were changed to the silica particles 6.
<Preparation of Developer 24>
7 parts of toner 23 and 193 parts of carrier 1 were mixed in a V blender to obtain a black developer 24. At this time, w1 / w2 = 0 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Comparative Example 4)
<Preparation of Toner 24>
100 parts by weight of toner base particles 1 obtained in Example 1, 0.7 parts by weight of silica particles 1 and 0.8 parts by weight of organic particles 1 were mixed by a Henschel mixer to obtain black toner 24.
<Preparation of Developer 25>
7 parts of toner 24 and 193 parts of carrier 1 were mixed in a V blender to obtain black developer 25. At this time, w1 / w2 = 0.88 and w2 ′ / wc = 3.0 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Comparative Example 5)
<Preparation of Toner 25>
100 parts by weight of toner base particles 1 obtained in Example 1, 2.2 parts by weight of silica particles 1 and 0.2 parts by weight of organic particles 1 were mixed with a Henschel mixer to obtain black toner 25.
<Preparation of Developer 26>
7 parts of toner 24 and 193 parts of carrier 1 were mixed in a V blender to obtain black developer 26. At this time, w1 / w2 = 11.0 and w2 ′ / wc = 7.4 × 10 ⁻⁴ . The evaluation results are shown in Table 1.

(Comparative Example 6)
<Preparation of Toner 26>
100 parts by weight of toner base particles 1 obtained in Example 1, 0.5 part by weight of silica particles 1 and 0.07 parts by weight of organic particles 1 were mixed with a Henschel mixer to obtain black toner 26.
<Preparation of Developer 27>
8 parts of toner 26 and 92 parts of carrier 3 were mixed in a V blender to obtain a black developer 27. At this time, w1 / w2 = 7.1 and w2 ′ / wc = 1.8 × 10 ⁻⁴ . The evaluation results are shown in Table 1.

(Comparative Example 7)
<Preparation of Toner 27>
100 parts by weight of toner base particles 1 obtained in Example 1, 2.0 parts by weight of silica particles 1 and 1.0 parts by weight of organic particles 1 were mixed with a Henschel mixer to obtain black toner 27.
<Preparation of Developer 28>
Toner 276 parts and carrier 4 94 parts were mixed in a V blender to obtain a black developer 28. At this time, w1 / w2 = 2.0 and w2 ′ / wc = 5.2 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Comparative Example 8)
<Preparation of Toner 28>
A black toner 28 was obtained in the same manner as in Example 1 except that the silica particles 1 were changed to the silica particles 7.
<Preparation of Developer 29>
7 parts of toner 28 and 193 parts of carrier 1 were mixed in a V blender to obtain a black developer 29. At this time, w1 / w2 = 3.5 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Comparative Example 9)
<Preparation of Toner 29>
A black toner 28 was obtained in the same manner as in Example 1 except that the silica particles 1 were changed to the silica particles 8.
<Preparation of Developer 30>
7 parts of toner 29 and 193 parts of carrier 1 were mixed in a V blender to obtain a black developer 30. At this time, w1 / w2 = 3.5 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Comparative Example 10)
<Preparation of Toner 30>
A black toner 30 was obtained in the same manner as in Example 1 except that the organic particles 1 were changed to the organic particles 8.
<Preparation of Developer 31>
7 parts of toner 30 and 193 parts of carrier 1 were mixed in a V blender to obtain a black developer 31. At this time, w1 / w2 = 3.5 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Comparative Example 11)
<Preparation of Toner 31>
A black toner 31 was obtained in the same manner as in Example 1 except that the organic particles 1 were changed to the organic particles 9.
<Preparation of Developer 32>
7 parts of toner 31 and 193 parts of carrier 1 were mixed in a V blender to obtain black developer 32. At this time, w1 / w2 = 3.5 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Comparative Example 12)
<Preparation of Toner 32>
A black toner 32 was obtained in the same manner as in Example 1 except that the organic particles 1 were changed to the organic particles 10.
<Preparation of Developer 33>
7 parts of toner 32 and 193 parts of carrier 1 were mixed in a V blender to obtain a black developer 33. At this time, w1 / w2 = 3.5 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Comparative Example 13)
<Preparation of Toner 33>
A black toner 33 was obtained in the same manner as in Example 1 except that the organic particles 1 were changed to the organic particles 11.
<Preparation of Developer 34>
7 parts of toner 33 and 193 parts of carrier 1 were mixed in a V blender to obtain a black developer 34. At this time, w1 / w2 = 3.5 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

(Comparative Example 14)
<Preparation of carrier 5>
Manganese-magnesium-strontium ferrite particles A were obtained in the same manner as in preparation of carrier 1.
A solution in which 2.0 parts by weight of a styrene / methyl methacrylate copolymer and 0.3 parts by weight of conductive carbon black (manufactured by Cabot, Vulcan XC72) are dissolved in 10 parts by weight of toluene, and manganese-magnesium-strontium ferrite particles A 100 parts by weight were put into a kneader, heated to 70 ° C. at normal pressure and stirred for 30 minutes, and then the solvent was distilled off under reduced pressure.
The obtained coated carrier was sieved with a 75 μm mesh to prepare a carrier 5 coated with a non-crosslinkable resin. The volume average particle diameter of the carrier 5 was 38 μm, and the ratio of 22 to 31 μm or less in the carrier particles was 20% by weight.

<Preparation of Developer 35>
A black developer 35 was obtained in the same manner except that carrier 1 was changed to carrier 5 in Example 1. At this time, w1 / w2 = 3.5 and w2 ′ / wc = 1.5 × 10 ⁻³ . The evaluation results are shown in Table 1.

  1a, 1b, 1c, 1d Charging means, 2a, 2b, 2c, 2d Exposure means, 3a, 3b, 3c, 3d Electrostatic charge image carrier (photoconductor), 4a, 4b, 4c, 4d Developing means, 10 Recording paper (Recording medium), 15 roll medium, 20 cyan developing unit, 30 magenta developing unit, 40 yellow developing unit, 50 black developing unit, 70a, 70b, 70c, 70d transfer means (transfer roll), 71, 72 roll, 80 transfer Voltage supply means, 90 light fixing means

Claims (12)

Contains toner and carrier,
The toner is composed of toner base particles containing a binder resin, a colorant, an infrared absorber, and a release agent, and an external additive.
The external additive contains silica particles and organic particles,
The silica particles are silica particles that are surface-treated with a silane coupling agent containing an amino group, and the number average primary particle size is 5 nm or more and 20 nm or less,
The organic particles are organic particles having a volume average particle size of 0.5 μm or more and 15 μm or less and an endothermic peak by differential scanning calorimetry of 80 ° C. or more and 140 ° C. or less,
The carrier is a resin-coated carrier having a core material and a coating resin layer containing a conductive material and a crosslinkable resin on the surface of the core material;
When the content of the silica particles with respect to 100 parts by weight of the toner base particles is w1 (parts by weight) and the content of the organic particles with respect to 100 parts by weight of the toner base particles is w2 (parts by weight), the following formula (1) is satisfied. ,
1.0 ≦ w1 / w2 ≦ 10.0 (1)
When the proportion of particles having a particle size of 22 μm or more and 31 μm or less of the carrier in the developer is wc (wt%) and the proportion of the organic particles in the developer is w2 ′ (wt%), the following formula (2) 2.0 × 10 ⁻⁴ ≦ w2 ′ / wc ≦ 5.0 × 10 ⁻³ (2)
Electrostatic image developer.   The electrostatic charge image developer according to claim 1, wherein the binder resin contains an amorphous polyester and a crystalline polyester, and the endothermic peak of the crystalline polyester measured by differential scanning calorimetry is 60 ° C. or higher and 120 ° C. or lower. .   The electrostatic image developer according to claim 1, wherein the organic particles contain at least one selected from the group consisting of a fatty acid metal salt, a higher fatty acid, and a higher alcohol.   The electrostatic image developer according to claim 1, wherein the resin-coated carrier is coated with a silicone resin.   The electrostatic charge image developer according to claim 1, wherein the carrier has a volume average particle diameter of 15 μm or more and 60 μm or less.   The electrostatic image developer according to claim 1, wherein the toner is a positively chargeable toner.   The electrostatic image developer according to claim 1, which is used for photofixing.   The electrostatic charge image developer according to claim 1, which is detached from an image forming apparatus including a light fixing unit that fixes a toner image on a surface of a transfer medium by irradiating light. A developer cartridge. An image carrier,
An electrostatic latent image forming means for forming an electrostatic latent image on the surface of the image carrier;
Developing means for developing the electrostatic latent image with the electrostatic charge image developer according to any one of claims 1 to 7 to form a toner image;
Transfer means for transferring the toner image onto the surface of the transfer target;
Fixing means for fixing the toner image transferred to the surface of the transfer medium by light fixing;
An image forming apparatus comprising:   The image forming apparatus according to claim 9, wherein the developing unit includes a plurality of developer holders having a peripheral speed of 1,000 mm / s or more. A charging step for charging the surface of the image carrier,
An electrostatic latent image forming step of forming an electrostatic latent image on the surface of the image carrier;
A developing step of developing the electrostatic latent image with a developer containing toner to form a toner image;
A transfer step of transferring the toner image to a transfer target; and a fixing step of fixing the transferred toner image to the transfer target by a light fixing method,
An image forming method, wherein the developer is the electrostatic charge image developer according to claim 1.   The image forming method according to claim 11, wherein a peripheral speed of a developer holding body that holds the developer is 1,000 mm / s or more.

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