JP2015034840A - Toner for electrostatic charge image development, electrostatic charge image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner for electrostatic charge image development that has excellent photo-fixability and suppresses the occurrence of color turbidity.SOLUTION: A toner for electrostatic charge image development includes toner particles having a core part including a binder resin, and a coating layer including a binder resin and infrared absorbent represented by the following general formula (1) and coating the core part. In the following general formula (1), Rand Reach independently represent a saturated hydrocarbon group, where the sum of the carbon number of Rand the carbon number of Ris 6 or more and 12 or less; Rrepresents a hydrogen atom or alkyl group; and X represents an oxygen atom or sulfur atom.

Description

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

In an electrophotographic image forming apparatus, an unfixed toner image formed on a recording medium is fixed by a fixing device to form an image. As this fixing device, a light fixing type fixing device for irradiating a toner image on a recording medium with light is known, and a toner containing an infrared absorber is known as a toner used for image formation of a light fixing type. Yes.
For example, Patent Document 1 discloses a flash fixing device in which a coating portion containing an infrared light absorber in the same resin as that of the resin is melted around a core containing a colorant in a binder resin. Color toners are disclosed.

JP 02-118670 A

  An object of the present invention is to provide a toner for developing an electrostatic image that is excellent in photofixability and hardly causes color turbidity.

Means for solving the above-mentioned problems are as follows.
The invention according to claim 1
A core containing a binder resin;
A coating layer containing a binder resin and an infrared absorber represented by the following general formula (1), covering the core;
An electrostatic charge image developing toner comprising toner particles having the following.

In General Formula (1), R ¹ and R ² each independently represent a saturated hydrocarbon group, provided that the total number of carbon atoms of R ¹ and R ² is 6 or more and 12 or less. R ³ represents a hydrogen atom or an alkyl group. X represents an oxygen atom or a sulfur atom.

The invention according to claim 2
The electrostatic image developing toner according to claim 1, wherein the binder resin contained in the coating layer is a polyester resin.

The invention according to claim 3
The electrostatic image developing toner according to claim 1, wherein the core portion further contains a colorant.

The invention according to claim 4
An electrostatic charge image developer comprising the electrostatic charge image developing toner according to claim 1.

The invention according to claim 5
An electrostatic charge image developing toner according to any one of claims 1 to 3 is accommodated,
A toner cartridge to be attached to and detached from the image forming apparatus.

The invention according to claim 6
A developing means for containing the electrostatic charge image developer according to claim 4 and developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer,
A process cartridge attached to and detached from the image forming apparatus.

The invention according to claim 7 provides:
An image carrier,
Charging means for charging the surface of the image carrier;
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image carrier;
Development means for containing the electrostatic charge image developer according to claim 4 and developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer;
Transfer means for transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
Fixing means for fixing the toner image by irradiating the toner image transferred onto the surface of the recording medium with light including infrared rays;
An image forming apparatus comprising:

The invention according to claim 8 provides:
A charging step for charging the surface of the image carrier;
An electrostatic charge image forming step of forming an electrostatic charge image on the surface of the charged image carrier;
A developing step of developing an electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer according to claim 4;
A transfer step of transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
A fixing step of fixing the toner image by irradiating the toner image transferred onto the surface of the recording medium with light including infrared rays;
An image forming method comprising:

According to the first aspect of the present invention, in the toner particles having the core and the coating layer, the infrared absorber contained in the coating layer is more light than the infrared absorber represented by the general formula (1). Provided is a toner for developing an electrostatic image that has excellent fixability and is less likely to cause color turbidity.
According to the second aspect of the present invention, for toner image having a core and a coating layer, for developing an electrostatic charge image that is less likely to cause color turbidity than when the binder resin contained in the coating layer is not a polyester resin. Toner is provided.
According to the invention of claim 3, the infrared absorbing agent represented by the general formula (1) is an infrared absorber contained in the coating layer in the toner particles having the core and the coating layer and the core containing the colorant. An electrostatic charge image developing toner that is excellent in photofixability and less likely to cause color turbidity is provided as compared with a case where it is not an agent.

According to the invention of claim 4, the toner particles contained in the toner have a core part and a coating layer, and the infrared absorber contained in the coating layer is not the infrared absorber represented by the general formula (1). As compared with the case, an electrostatic charge image developer which is excellent in photofixability and hardly causes color turbidity is provided.
According to the invention of claim 5, the toner particles contained in the toner have a core part and a coating layer, and the infrared absorber contained in the coating layer is not the infrared absorber represented by the general formula (1). As compared with the case, a toner cartridge having excellent toner photofixability and less color turbidity is provided.
According to the invention of claim 6, the toner particles contained in the toner in the developer have a core and a coating layer, and the infrared absorber contained in the coating layer is represented by the general formula (1). A process cartridge is provided that is superior in the photofixability of the developer and is less likely to cause color turbidity compared to a case where it is not an infrared absorber.
According to the invention of claim 7, the toner particles contained in the toner in the developer have a core and a coating layer, and the infrared absorber contained in the coating layer is represented by the general formula (1). An image forming apparatus is provided that is superior in the photofixability of the developer and less likely to cause color turbidity as compared with the case where the composition is not an infrared absorber.
According to the invention of claim 8, the toner particles contained in the toner in the developer have a core part and a coating layer, and the infrared absorber contained in the coating layer is represented by the general formula (1). An image forming method is provided that is superior in the photofixability of the developer and less likely to cause color turbidity as compared with the case where it is not an infrared absorber.

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

  Embodiments of the present invention will be described below. These descriptions and examples are illustrative of the invention and are not intended to limit the scope of the invention.

<Toner for electrostatic image development>
The electrostatic image developing toner (also referred to as “toner”) according to this embodiment includes toner particles and may further include an external additive. That is, in the present embodiment, the toner particles may be toner, or the toner particles may be externally added with the toner as toner.

  The toner particles constituting the toner according to the exemplary embodiment include a core portion including a binder resin and a coating layer that covers the core portion. The coating layer is a layer containing a binder resin and an infrared absorber represented by the following general formula (1). The binder resin contained in the core and the binder resin contained in the coating layer may be the same type of resin or different types of resins.

In the general formula (1), ^{R 1} and ^{R 2} independently represent a saturated hydrocarbon group, provided that (number of carbon atoms constituting the ^{R 1} 1 single) number of carbon atoms of ^{R 1} and ^{R 2} of the carbon atoms (1 The total number of carbon atoms constituting each R ² is 6 or more and 12 or less. R ³ represents a hydrogen atom or an alkyl group. X represents an oxygen atom or a sulfur atom.

The present invention is configured from the following viewpoints.
If a method of providing a coating layer containing an infrared absorber on the surface of toner particles not containing an infrared absorber is employed, a photofixing toner can be easily produced using non-photofixing toner particles. At that time, in order to secure the photofixability of the toner image, the absolute amount of the infrared absorber contained in the toner is required to some extent, so that it is compared with the concentration of the infrared absorber when the entire toner particles contain the infrared absorber. It is necessary to increase the concentration of the infrared absorber in the coating layer.
In contrast to the above, among the various infrared absorbers, squarylium-based compounds can be dissolved or dispersed in the resin at a relatively high concentration, so that an appropriate amount can be contained in the coating layer, and photofixability of the toner image can be improved. This is advantageous in that it can be secured. In addition, the squarylium-based compound is advantageous in that the fixed image has less color turbidity than other infrared absorbers.
Further, among the squarylium compounds, the infrared absorber represented by the general formula (1) has higher infrared absorption efficiency than the squarylium compound deviating from the general formula (1), and therefore, the fixing property to a recording medium. Therefore, it is possible to reduce the amount of the infrared absorbing agent necessary to ensure the color turbidity, thereby reducing the color turbidity. In addition, the infrared absorber represented by the general formula (1) has less color turbidity as compared with the squarylium compound deviating from the general formula (1).
Therefore, the toner according to the exemplary embodiment can be easily manufactured, has excellent light fixing property to a recording medium, and hardly causes color turbidity.
In addition, color turbidity means that an infrared absorber exhibits an undesirable color by absorbing light in the wavelength region of visible light.

  Hereinafter, the configuration of the toner according to the exemplary embodiment will be described in detail.

[Core]
The core part includes a binder resin, and may further include a colorant, a release agent, and other additives. The core part does not need to contain the infrared absorbent represented by the general formula (1) and other infrared absorbents. From the viewpoint of ease of production and suppression of color turbidity, infrared absorption is possible. It is desirable that no agent is contained.
Hereinafter, the components contained in the core will be described in detail.

-Binder resin-
Examples of the binder resin include thermoplastic resins such as epoxy resin, styrene-acrylic resin, polyamide resin, polyester resin, polyvinyl resin, polyolefin resin, polyurethane resin, polybutadiene resin, and modified rosin.
These resins may be used alone or in combination of two or more.

The weight average molecular weight (Mw) of the binder resin contained in the core is preferably 1,000 or more and 100,000 or less, and more preferably 5,000 or more and 50,000 or less. When the weight average molecular weight is 1,000 or more, image offset and fusion are unlikely to occur, and when it is 100,000 or less, the amount of heat necessary for fixing the toner image can be suppressed.
The weight average molecular weight and number average molecular weight of the resin are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is performed using HLC-8120 manufactured by Tosoh Corporation as a measuring device, TSKgel SuperHM-M15 cm manufactured by Tosoh Corporation as a column, and tetrahydrofuran as a solvent. The weight average molecular weight and the number average molecular weight are calculated using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample from this measurement result.

The glass transition temperature (Tg) of the binder resin contained in the core is preferably 50 ° C. or higher and 150 ° C. or lower, and more preferably 55 ° C. or higher and 70 ° C. or lower. If the glass transition temperature is within the above range, the resin is melted with an appropriate amount of heat, and the toner image is fixed.
The glass transition temperature of the resin is determined from a DSC curve obtained by differential scanning calorimetry (DSC). More specifically, it is determined by “extrapolated glass transition start temperature” described in JIS K7121-1987 “Method for Measuring Glass Transition Temperature”.

  The content of the binder resin contained in the core is preferably 40% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 90% by mass or less, and further preferably 60% by mass or more and 85% by mass or less.

-Colorant-
The core part may contain a colorant. The colorant contained in the core may be a pigment or a dye. A colorant may be used individually by 1 type and may use 2 or more types together.

  Examples of the colorant include carbon black, chrome yellow, hansa yellow, benzidine yellow, sren yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliantamine 3B, brilliant. Carmine 6B, Dupont Oil Red, Pyrazolone Red, Resol Red, Rhodamine B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Phthalocyanine Green, Pigments such as malachite green oxalate; acridine, xanthene, azo, benzoquinone , Azine, anthraquinone, thioindigo, dioxazine, thiazine, azomethine, indigo dyes, phthalocyanine, aniline black, polymethine, triphenylmethane dyes, diphenylmethane dyes, dye thiazole like; and the like.

  As the colorant, a surface-treated colorant may be used as necessary, or it may be used in combination with a dispersant.

  The content of the colorant is preferably 1% by mass or more and 30% by mass or less of the core, and more preferably 3% by mass or more and 15% by mass or less.

-Release agent-
The core part may contain a release agent. A mold release agent may be used individually by 1 type, and may use 2 or more types together.
Examples of mold release agents include hydrocarbon waxes; natural waxes such as carnauba wax, rice wax, and candelilla wax; synthetic or mineral / petroleum waxes such as montan wax; ester types such as fatty acid esters and montanic acid esters Wax; and the like.

The melting temperature of the release agent is preferably from 50 ° C. to 110 ° C., more preferably from 60 ° C. to 100 ° C.
The melting temperature of the release agent is determined by the “melting peak temperature” described in the method for determining the melting temperature in JIS K7121-1987 “Method for measuring the transition temperature of plastic” from the DSC curve obtained by differential scanning calorimetry (DSC). Ask.

  The content of the release agent is preferably 1% by mass or more and 20% by mass or less of the core part, and more preferably 5% by mass or more and 15% by mass or less.

-Other additives-
Examples of other additives internally added to the core include well-known additives such as a magnetic material, a charge control agent, and inorganic powder.

(Coating layer)
The coating layer contains a binder resin and an infrared absorber represented by the general formula (1).
The thickness of the coating layer is preferably 0.5% or more and 10% or less, and preferably 0.7% or more and 8% or less of the radius of the toner particles, from the viewpoint of manufacturing suitability and ensuring the absolute amount of the infrared absorber. More desirably, 1% to 5% is further desirable, and 1.5% to 4% is even more desirable.
Hereinafter, the components contained in the coating layer will be described in detail.

-Infrared absorber-
The coating layer contains an infrared absorber represented by the following general formula (1).

In General Formula (1), R ¹ and R ² each independently represent a saturated hydrocarbon group, provided that the total number of carbon atoms of R ¹ and R ² is 6 or more and 12 or less. R ³ represents a hydrogen atom or an alkyl group. X represents an oxygen atom or a sulfur atom.

Total R number of carbon atoms of ¹ (number of carbon atoms constituting one of the ^{R 1)} and the ^{R 2} carbon atoms (number of carbon atoms constituting one of ^{R 2)} is 6 to 12.
A compound in which the total number of carbon atoms of R ¹ and R ² is 5 or less is difficult to synthesize into the intended molecular structure.
A compound having a total of 13 or more carbon atoms in R ¹ and R ² is inferior in infrared absorption efficiency and color turbidity.
The total number of carbon atoms of R ¹ and R ² is preferably 7 or more and 10 or less, and more preferably 8 or more and 10 or less, from the viewpoint of ease of synthesis, high infrared absorption efficiency, and low color turbidity. More desirable.

R carbon number of ¹ (number of carbon atoms constituting one of R ^1), the ease of synthesis, the infrared absorption efficiency of height and in terms of lack of color turbidity, 3 or more preferably the lower limit 4 or more preferably, 8 is preferably 6 or less and more preferably below the upper limit value, (the number of carbon atoms constituting the R ¹ 1 single) number of carbon atoms in R ¹ is 4 or 5 are particularly desirable.
R ² of carbon number (number of carbon atoms constituting the one ^{R 2)} also are similar to those ^{for R 1.}

Difference R number of carbon atoms of ¹ (the number of carbon atoms constituting one of R ¹⁾ the number of carbon atoms in R ² (the number of carbon atoms constituting the one R ²⁾ is the ease of synthesis, the infrared absorption efficiency high From the viewpoint of thickness and low color turbidity, the smaller the number, the more desirable, 1 or 0 is desirable, and 0 is particularly desirable.

The saturated hydrocarbon group represented by R ¹ and R ² may be an alkyl group or a cycloalkyl group. In the case of an alkyl group, it may be linear or branched. In the case of a cycloalkyl group, it may be monocyclic or polycyclic. But you can.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, n-hexyl group, isohexyl group, sec-hexyl group, tert-hexyl group, n-heptyl group, isoheptyl group, sec-heptyl group, tert-heptyl group, n-octyl group, isooctyl group, sec -Octyl group, tert-octyl group, n-nonyl group, isononyl group, sec-nonyl group, tert-nonyl group, n-decyl group, isodecyl group, sec-decyl group, tert-decyl group, n-undecyl group, An isoundecyl group etc. are mentioned.
Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, and the like.
The saturated hydrocarbon group represented by R ¹ and R ² may be substituted with a halogen atom (for example, fluorine, chlorine, bromine, iodine).

R ³ represents a hydrogen atom or an alkyl group, and is preferably a hydrogen atom.
The alkyl group preferably has 1 to 6 carbon atoms, and more preferably 1 to 3 carbon atoms.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, Examples thereof include a tert-pentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, and a tert-hexyl group.

  X represents an oxygen atom or a sulfur atom, and is preferably a sulfur atom.

The infrared absorber represented by the general formula (1) preferably has a maximum absorption wavelength (λ _max ) in a wavelength range of 760 nm to 1200 nm from the viewpoint of infrared absorption efficiency.

  Specific examples of the infrared absorber represented by the general formula (1) include the following exemplary compounds (1) to (12).

The maximum absorption wavelength (λ _max ) of the above exemplified compounds (1) to (12) in tetrahydrofuran is as follows. _{(1): λ max 809nm,} (2): λ max 813nm, (3): λ max 810nm, (4): λ max 812nm, (5): λ max 869nm, (6): λ max 814nm, (7 ): Λ _max 811 nm, (8): λ _max 863 nm, (9): λ _max 812 nm, (10): λ _max 812 nm, (11): λ _max 812 nm, (12): λ _max 812 nm.

  The infrared absorber represented by the general formula (1) can be synthesized by, for example, a synthesis method described in JP-A No. 2001-11070.

  The content of the infrared absorber represented by the general formula (1) in the coating layer is preferably 0.5% by mass or more, more preferably 0.8% by mass or more in terms of more excellent photofixability of the image. Desirably, 1.0 mass% or more is more desirable. On the other hand, it is preferably 3.0% by mass or less, more preferably 2.8% by mass or less, and still more preferably 2.5% by mass or less from the viewpoint that image turbidity is less likely to occur.

  Although a coating layer may contain other infrared absorbers other than the infrared absorber represented by the said General formula (1), it may not contain other infrared absorbers from a viewpoint of suppressing generation | occurrence | production of color turbidity. desirable. Examples of other infrared absorbers include conventionally known infrared absorbers such as squarylium compounds, croconium compounds, naphthalocyanine compounds, cyanine compounds, and aminium compounds.

-Binder resin-
Examples of the binder resin contained in the coating layer include thermoplastic resins such as epoxy resin, styrene-acrylic resin, polyamide resin, polyester resin, polyvinyl resin, polyolefin resin, polyurethane resin, polybutadiene resin, and modified rosin.
These resins may be used alone or in combination of two or more.

As the binder resin contained in the coating layer, a polyester resin is suitable. The polyester resin is easy to dissolve or disperse the infrared absorber represented by the general formula (1), and the infrared absorption efficiency of the resin composition is high because the solubility or dispersibility of the infrared absorber is good. Since it is possible to reduce the amount of the infrared absorber necessary for securing the fixing property to the recording medium, it is possible to reduce the color turbidity.
As a polyester resin, the condensation polymer of polyhydric carboxylic acid and polyhydric alcohol is mentioned, for example. As the polyester resin, a commercially available product may be used, or a synthesized resin may be used.

Examples of the polyvalent carboxylic acid include aliphatic dicarboxylic acids (eg, oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenyl succinic acid, adipic acid, sebacic acid, etc.) Alicyclic dicarboxylic acids (for example, cyclohexanedicarboxylic acid), aromatic dicarboxylic acids (for example, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), their anhydrides, or lower (for example, having 1 or more carbon atoms) 5 or less) alkyl esters. Among these, as the polyvalent carboxylic acid, for example, an aromatic dicarboxylic acid is desirable.
The polyvalent carboxylic acid may be used in combination with a dicarboxylic acid or a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (for example, having 1 to 5 carbon atoms) alkyl esters.
A polyvalent carboxylic acid may be used individually by 1 type, and may use 2 or more types together.

Examples of the polyhydric alcohol include aliphatic diols (for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (for example, cyclohexanediol, cyclohexanedimethanol, Hydrogenated bisphenol A, etc.) and aromatic diols (for example, ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, etc.). Among these, as the polyhydric alcohol, for example, aromatic diols and alicyclic diols are desirable, and aromatic diols are more desirable.
The polyhydric alcohol may be used in combination with a diol and a trivalent or higher alcohol having a crosslinked structure or a branched structure. Examples of the trivalent or higher alcohol include glycerin, trimethylolpropane, pentaerythritol and the like.
A polyhydric alcohol may be used individually by 1 type, and may use 2 or more types together.

  The glass transition temperature (Tg) of the polyester resin is preferably from 50 ° C. to 80 ° C., more preferably from 50 ° C. to 65 ° C.

The weight average molecular weight (Mw) of the polyester resin is preferably from 5,000 to 1,000,000, more preferably from 7,000 to 500,000.
The number average molecular weight (Mn) of the polyester resin is preferably 2,000 or more and 100,000 or less.
The molecular weight distribution Mw / Mn of the polyester resin is preferably from 1.5 to 100, and more preferably from 2 to 60.

-Other ingredients-
The coating layer may contain known additives such as a magnetic material, a charge control agent, and inorganic powder.

[Characteristics of toner particles]
The volume average particle diameter (D50v) of the toner particles is preferably 2 μm or more and 10 μm or less, and more preferably 4 μm or more and 8 μm or less.

The volume average particle diameter (D50v) of the toner particles is measured using a Coulter Multisizer II type (manufactured by Beckman-Coulter, Inc., aperture diameter 100 μm).
As a sample for measurement, 0.5 mg or more and 50 mg or less of toner particles are added to 2 ml of a 5% by weight aqueous solution of a surfactant (preferably sodium alkylbenzenesulfonate), and this is added to 100 ml or more of electrolyte (Itoton II manufactured by Beckman Coulter, Inc.). It is added to the following and prepared by carrying out a dispersion treatment for 1 minute with an ultrasonic disperser.
Using the above-mentioned apparatus and measurement sample, the particle size of 50,000 particles of 2 μm or more and 60 μm or less was measured, and the volume-based median diameter (cumulative 50% particle diameter) was determined as the volume average particle diameter (D50v ).

  The toner particle shape factor SF1 is preferably 110 or more and 150 or less, and more preferably 120 or more and 140 or less.

The toner particle shape factor SF1 is obtained by the following equation.
Formula: SF1 = (ML ² / A) × (π / 4) × 100
In the formula, ML is the absolute maximum length of the toner particles, and A is the projected area of the toner particles. Specifically, the shape factor SF1 is quantified by analyzing a scanning electron microscope (SEM) image using an image analyzer, and is calculated as follows. That is, a microscopic image of particles dispersed on the surface of a slide glass is taken into a Luzex image analyzer by a video camera, the maximum length and the projection area of each of 100 particles are obtained, and each SF1 is calculated by the above formula. It is obtained by calculating | requiring the average value of.

(External additive)
Examples of the external additive include inorganic particles. As the inorganic particles, SiO ₂ , TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, CaO, K ₂ O, Na ₂ O, ZrO ₂ , CaO. _{SiO 2, K 2 O · (} TiO 2) n, Al 2 O 3 · 2SiO 2, CaCO 3, MgCO 3, BaSO 4, MgSO 4 , and the like.

The surface of the inorganic particles as an external additive is preferably subjected to a hydrophobic treatment. The hydrophobic treatment is performed, for example, by immersing inorganic particles in a hydrophobic treatment agent. The hydrophobizing agent is not particularly limited, and examples thereof include silane coupling agents, silicone oils, titanate coupling agents, aluminum coupling agents and the like. These may be used individually by 1 type and may use 2 or more types together.
The amount of the hydrophobizing agent is, for example, 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the inorganic particles.

  Examples of external additives include resin particles (resin particles such as polystyrene, PMMA, and melamine resin), cleaning activators (for example, metal salts of higher fatty acids typified by zinc stearate, particles of a fluorine-based high molecular weight substance), and the like. Can be mentioned.

  The external additive amount of the external additive is, for example, preferably 0.01% by mass or more and 5% by mass or less, and more preferably 0.01% by mass or more and 2% by mass or less with respect to the toner particles.

[Toner Production Method]
The toner according to the exemplary embodiment may be produced by producing toner particles, and the toner particles may be used as a toner, or an external additive may be externally added to the toner particles.

  Examples of the toner particle manufacturing method include: (i) a manufacturing method in which core particles to be a core portion are manufactured, and a coating layer is formed on the surface of the core particles; (ii) the core portion and the coating layer are integrally formed. The manufacturing method to form is mentioned.

The manufacturing method (i) is performed as follows, for example.
First, the core particles are produced by a dry production method (for example, a kneading pulverization method) or a wet production method (for example, an aggregation coalescence method, a suspension polymerization method, a dissolution suspension method, etc.).
Separately, the particles for forming the coating layer containing the binder resin and the infrared absorber represented by the general formula (1) may be prepared by a dry manufacturing method (for example, a kneading and pulverizing method) or a wet manufacturing method (for example, an aggregation coalescence method, (Suspension polymerization method, dissolution suspension method, etc.). The volume average particle diameter of the coating layer forming particles is, for example, 1/50 or more and 1/10 or less of the volume average particle diameter of the core particles.
Then, the core particles and the coating layer forming particles are mixed and stirred to attach the coating layer forming particles to the surface of the core particles to form a film. Desirably, the coating layer forming particles are adhered to the surface of the core particle, and then impact force is applied, for example, by colliding with a plate, and the coating layer forming particles are melted by the impact energy.
In the above production method, the thickness of the coating layer can be adjusted by changing the particle size of the core particles and the coating layer forming particles and the mixing ratio of the core particles and the coating layer forming particles.
In the present specification, the above production method is sometimes referred to as “adhesion coating method”.

The production method (ii) is carried out in the following manner, for example, according to a known aggregation and coalescence method.
First, a resin particle dispersion in which resin particles serving as a binder resin in the core are dispersed; an infrared absorbent-containing resin particle dispersion in which resin particles containing an infrared absorbent are dispersed are prepared. When obtaining a toner containing a colorant or a release agent, a colorant dispersion and a release agent dispersion are also prepared.

Preparation of an infrared absorbent-containing resin particle dispersion is performed by, for example, applying a shearing force to a solution obtained by mixing a dispersion medium (for example, water, ethers, ketones, alcohols, etc.), a resin, and an infrared absorbent with a disperser. May be done by giving. For the purpose of further stabilizing the dispersed resin particles, a dispersant (for example, a water-soluble polymer, a surfactant, an inorganic salt) may be used.
In addition, resin particles containing an infrared absorber may be dispersed in a dispersion medium by a phase inversion emulsification method. The phase inversion emulsification method is a method in which a resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, neutralized by adding a base to the organic continuous phase (O phase), and then water (W phase). Is used to perform phase inversion from W / O to O / W and disperse the resin in an aqueous medium in the form of particles.
The amount of the infrared absorber used for the preparation of the dispersion may be in the range of 0.5 to 5 parts by mass, and preferably 1 to 3 parts by mass with respect to 100 parts by mass of the resin.
The volume average particle size of the infrared absorbent-containing resin particles may be in the range of 50 nm to 500 nm, preferably 100 nm to 400 nm, more preferably 200 nm to 300 nm.

  Then, in the resin particle dispersion for the core (if necessary, a dispersion obtained by mixing the colorant dispersion and the release agent dispersion), the resin particles (if necessary, the colorant and the release agent are added). Agglomerate to form first agglomerated particles, which are mixed with an infrared absorbent-containing resin particle dispersion, and agglomerated so that the infrared absorbent-containing resin particles adhere to the surface of the first agglomerated particles. Thus, second aggregated particles are formed. Thereafter, the dispersion liquid in which the second aggregated particles are dispersed is heated, and the second aggregated particles are fused and united to obtain toner particles having a core / shell structure.

  The toner according to the exemplary embodiment is manufactured, for example, by adding an external additive to dry toner particles and mixing them. Mixing is preferably performed by, for example, a V blender, a Henschel mixer, a Ladyge mixer, or the like. Furthermore, if necessary, coarse toner particles may be removed using a vibration classifier, a wind classifier, or the like.

<Electrostatic image developer>
The electrostatic charge image developer according to the exemplary embodiment includes the toner according to the exemplary embodiment.
The electrostatic image developer according to this embodiment may be a one-component developer including only the toner according to this embodiment, or may be a two-component developer mixed with the toner and a carrier.

There is no restriction | limiting in particular as a carrier, You may use a well-known carrier. Examples of carriers include a coated carrier in which the surface of a core made of magnetic powder is coated with a resin; a magnetic powder-dispersed carrier in which magnetic powder is dispersed in a matrix resin; and a porous magnetic powder impregnated with resin. Resin impregnated type carriers; and the like.
The magnetic powder-dispersed carrier, the resin-impregnated carrier, and the conductive particle-dispersed carrier may be carriers in which the constituent particles of the carrier are used as a core and the surface thereof is coated with a resin.

  Examples of the magnetic powder include magnetic metals such as iron, nickel and cobalt; and magnetic oxides such as ferrite and magnetite.

  Examples of the conductive particles include metals such as gold, silver, and copper; particles such as carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate.

  Examples of the coating resin and matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylic. Examples include an acid copolymer, a straight silicone resin containing an organosiloxane bond or a modified product thereof, a fluororesin, a polyester, a polycarbonate, a phenol resin, and an epoxy resin. The coating resin and the matrix resin may contain an additive such as a conductive material.

In order to coat the surface of the core material with a resin, a method of coating with a coating layer forming solution in which a coating resin and various additives (used as necessary) are dissolved in an appropriate solvent may be mentioned. The solvent is not particularly limited, and may be selected in consideration of the type of resin used, application suitability, and the like.
Specific resin coating methods include a dipping method in which a core material is immersed in a coating layer forming solution; a spray method in which the coating layer forming solution is sprayed on the surface of the core material; A fluidized bed method in which a coating layer forming solution is sprayed; a kneader coater method in which a carrier core material and a coating layer forming solution are mixed in a kneader coater, and then the solvent is removed;

  The mixing ratio (mass ratio) of the toner and the carrier in the two-component developer is preferably toner: carrier = 1: 100 to 30: 100, and more preferably 3: 100 to 20: 100.

<Image forming apparatus and image forming method>
The image forming apparatus according to the present embodiment includes an image carrier, a charging unit that charges the surface of the image carrier, an electrostatic image forming unit that forms an electrostatic image on the surface of the charged image carrier, and an electrostatic charge. Development means for containing an image developer and developing the electrostatic image formed on the surface of the image carrier as a toner image with the electrostatic image developer, and the toner image formed on the surface of the image carrier as a recording medium Transfer means for transferring to the surface of the recording medium, and fixing means for fixing the toner image by irradiating the toner image transferred to the surface of the recording medium with light including infrared rays. The electrostatic charge image developer according to this embodiment is applied as the electrostatic charge image developer.

  In the image forming apparatus according to this embodiment, a charging process for charging the surface of the image carrier, an electrostatic charge image forming process for forming an electrostatic image on the surface of the charged image carrier, and an electrostatic charge according to this embodiment. A developing step of developing an electrostatic charge image formed on the surface of the image carrier as a toner image with an image developer; a transfer step of transferring the toner image formed on the surface of the image carrier to the surface of the recording medium; An image forming method (an image forming method according to the present embodiment) is provided that includes a fixing step of fixing the toner image by irradiating the toner image transferred onto the surface of the recording medium with light including infrared rays.

The image forming apparatus according to the present embodiment is a direct transfer type apparatus that directly transfers a toner image formed on the surface of an image carrier to a recording medium; the toner image formed on the surface of the image carrier is transferred to an intermediate transfer member An intermediate transfer type apparatus that primarily transfers the toner image transferred to the surface of the intermediate transfer body and then secondary transfer the toner image to the surface of the recording medium; after the toner image is transferred, the surface of the image carrier before charging is cleaned. An apparatus provided with a cleaning unit; a known image forming apparatus such as an apparatus provided with a charge removing unit that discharges the surface of an image holding member by irradiating a discharge light after charging a toner image and before charging is applied.
In the case of an intermediate transfer type apparatus, the transfer unit includes, for example, an intermediate transfer body on which a toner image is transferred to the surface and a primary transfer that primarily transfers the toner image formed on the surface of the image holding body to the surface of the intermediate transfer body And a secondary transfer unit that secondarily transfers the toner image transferred onto the surface of the intermediate transfer member onto the surface of the recording medium.

  In the image forming apparatus according to the present embodiment, for example, the part including the developing unit may have a cartridge structure (process cartridge) that is detachable from the image forming apparatus. As the process cartridge, for example, a process cartridge that accommodates the electrostatic charge image developer according to this embodiment and includes a developing unit is preferably used.

  Hereinafter, an example of the image forming apparatus of the present embodiment will be described with reference to the drawings. In addition, the main part shown to a figure is demonstrated and the description is abbreviate | omitted about others.

  FIG. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present exemplary embodiment. The image forming apparatus shown in FIG. 1 forms an image with four color toners of black (K), yellow (Y), magenta (M), and cyan (C).

  The image forming apparatus shown in FIG. 1 includes four image forming units 312K, 312Y, 312M, and 312C arranged in parallel from the upstream side to the downstream side in the conveyance direction of the recording medium. A light fixing device 326 (an example of a fixing unit) of a method of applying light irradiation (light fixing method) is provided.

  The image forming apparatus illustrated in FIG. 1 includes a paper feed roller 328, and the recording medium P is conveyed by the paper feed roller 328. The conveyance speed (process speed) of the recording medium P is preferably 1000 mm / sec or more, and more preferably 1200 mm / sec or more.

  In the image forming apparatus shown in FIG. 1, toner images are sequentially transferred in electrophotographic manner by the image forming units 312 </ b> K, 312 </ b> Y, 312 </ b> M, and 312 </ b> C onto the recording medium P drawn out from the roll state, and then light-fixed to the toner images. Photofixing is performed by the device 326 to form an image.

The black image forming unit 312K is a known electrophotographic image forming unit, and includes a photosensitive member 314K (an example of an image carrier), a charger 316K (an example of a charging unit), and an exposure unit 318K (an electrostatic charge image forming unit). An example of a unit), a developing device 320K (an example of a developing unit), a cleaner 322K (an example of a cleaning unit), and a transfer unit 324K (an example of a transfer unit). The same applies to the image forming units 312Y, 312M, and 312C for yellow, magenta, and cyan.
When used for monochrome image formation, only the image forming unit 312K may be provided.

  There is no restriction | limiting in particular in the light source of the optical fixing device 326, You may employ | adopt well-known light sources, such as a halogen lamp, a mercury lamp, and an infrared laser.

As a light source of the light fixing device 326, a flash lamp in which a rare gas such as xenon is enclosed is desirable in that it can emit high-output light in a short time.
When using a flash lamp, irradiation energy per unit area, 1.0 J / cm ² or more 7.0J / cm ² or less is desirable, 2J / cm ² or more 5 J / cm ² or less is more preferable. Here, the irradiation energy per unit area is the sum of the irradiation energy of each time when the toner is irradiated with light multiple times.

  As the light fixing method, a delay method in which a plurality of flash lamps emit light with a time difference is desirable. The delay system is a system in which a plurality of flash lamps are arranged, each lamp is delayed by 0.01 msec to 100 msec to emit light, and the same portion is illuminated a plurality of times. In the delay method, light energy is divided and supplied to the toner image, so that the fixing conditions are mild and it is easy to realize both void resistance and fixing property.

The number of flash lamps is preferably 1 or more and 20 or less, more preferably 2 or more and 10 or less. The time difference between one and 20 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. Once the irradiation energy of light emitted in one flashlamp, 0.1 J / cm ² or more 1 J / cm ² or less is preferable, 0.4 J / cm ² or more 0.8 J / cm ² or less is more preferable.

<Process cartridge, toner cartridge>
The process cartridge according to the present exemplary embodiment includes a developing unit that stores the electrostatic charge image developer according to the present exemplary embodiment, and develops the electrostatic charge image formed on the surface of the image carrier as a toner image by the developer. It is attached to and detached from the image forming apparatus.
The process cartridge according to the present embodiment is not limited to the above-described configuration. In addition to the developing unit, at least one selected from other units such as an image holding member, a charging unit, an electrostatic charge image forming unit, a cleaning unit, and a transfer unit. The structure provided with one may be sufficient.

  The toner cartridge according to the present embodiment accommodates the toner according to the present embodiment and is attached to and detached from the image forming apparatus. The toner cartridge contains toner for replenishment to be supplied to the developing means provided in the image forming apparatus. When the amount of toner stored in the toner cartridge mounted on the image forming apparatus becomes low, the toner cartridge is replaced.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example.
In the following description, “part” and “%” are based on mass unless otherwise specified.

<Preparation of first resin particle dispersion>
・ Styrene 320 parts ・ N-butyl acrylate 80 parts ・ Acrylic acid 10 parts ・ Dodecanethiol 10 parts ・ Nonionic surfactant (Sanyo Kasei nonipol 400) 6 parts ・ Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd.) Neogen R) 10 parts 550 parts of ion-exchanged water The above materials were placed in a flask, dispersed and emulsified, and 50 parts of ion-exchanged water in which 4 parts of ammonium persulfate was dissolved was added while slowly stirring and mixing for 10 minutes. . Thereafter, the inside of the flask was replaced with nitrogen, and the system was heated with an oil bath while stirring to 70 ° C., and emulsion polymerization was continued for 5 hours to obtain a resin particle dispersion having a solid content of 43%.
The volume average particle diameter of the resin particles was 155 nm, the glass transition temperature was 54 ° C., and the weight average molecular weight was 33,000.

<Preparation of second resin particle dispersion>
As a polymer particle dispersion of polymerized rosin ester, Haristar Kasei Co., Ltd. Harrier Star SK-385NS (softening point 85 ° C., acid value 8.0 mgKOH / g, solid content 50%) was prepared.

<Synthesis of polyester resin (1)>
・ Ethylene glycol (Wako Pure Chemical Industries) 37 parts ・ Neopentyl glycol (Wako Pure Chemical Industries) 65 parts ・ 1,9-nonanediol (Wako Pure Chemical Industries) 32 parts ・ Terephthalic acid (Wako Pure) (Manufactured by Yakuhin Kogyo Co., Ltd.) 236 parts The above materials were charged into a flask and the temperature was raised to 200 ° C over 1 hour. After confirming that the reaction system was stirred, 1.2 parts of dibutyltin oxide was added. . Subsequently, the temperature was raised from the same temperature to 240 ° C. over 6 hours while distilling off the generated water, and the dehydration condensation reaction was continued at 240 ° C. for 4 hours. The acid value was 9.4 mg KOH / g, the weight average molecular weight was 13, 000 and a polyester resin (1) having a glass transition temperature of 62 ° C. were obtained.

<Preparation of third resin particle dispersion>
The polyester resin (1) was transferred in a molten state to Cavitron CD1010 (manufactured by Eurotech) at a rate of 100 parts per minute. Separately, a 0.37% dilute ammonia water obtained by diluting reagent ammonia water with ion exchange water is prepared, and the polyester resin (1) is heated at 120 ° C. with a heat exchanger at a rate of 0.1 liter per minute. It was transferred to the above Cavitron along with the transfer. The Cavitron was operated under conditions of a rotor rotation speed of 60 Hz and a pressure of 5 kg / cm ² , and resin particles having a volume average particle size of 160 nm, a solid content of 40%, a glass transition temperature of 62 ° C., and a weight average molecular weight of 13,000 were dispersed. A resin particle dispersion was obtained.

<Preparation of Colorant Dispersion (C)>
・ Cyan pigment (CI Pigment Blue 15: 3, manufactured by Dainichi Seika Co., Ltd.) 50 parts ・ Anionic surfactant (Neogen R, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts ・ Ion-exchanged water 200 parts Then, a dispersion treatment was performed for 1 hour using a high-pressure impact disperser Optimizer (HJP30006 manufactured by Sugino Machine Co.) to obtain a colorant dispersion (C). The colorant dispersion (C) had a volume average particle size of 185 nm and a solid content of 20%.

<Preparation of release agent dispersion (P)>
・ 46 parts of paraffin wax (HNP0190 manufactured by Nippon Seiwa Co., Ltd., melting point 85 ° C.) 4 parts of cationic surfactant (Sanisol B50 manufactured by Kao Corporation) 200 parts of ion-exchanged water The above materials are mixed and heated to 95 ° C. Then, after dispersion using a homogenizer (Ultra Turrax T50 manufactured by IKA), dispersion treatment was performed using a pressure discharge type homogenizer to obtain a release agent dispersion having a volume average particle size of 220 nm and a release agent concentration of 20%.

<Creation of carrier>
Ferrite particles (average particle size 35 μm, volume electric resistance 108 Ω · cm) 100 parts toluene 14 parts perfluorooctylethyl acrylate / methyl methacrylate copolymer (copolymerization ratio 10/90, weight average molecular weight 80,000) 6 parts, carbon black (VXC-72 manufactured by Cabot Corporation) 0.12 parts, crosslinked melamine resin particles (number average particle size 0.3 μm) 0.3 parts The above materials other than ferrite particles are dispersed with a stirrer for 10 minutes and coated A layer forming solution was prepared. The coating layer forming solution and the ferrite particles are put into a vacuum degassing kneader and stirred at 60 ° C. for 30 minutes, and then the pressure is reduced to distill off toluene to obtain a carrier having a resin coating layer on the ferrite particle surface. It was.

<Example 1>
[Preparation of Infrared Absorber-Containing Resin Particles (1)]
-Polyester resin (1) 156.8 parts-Methyl ethyl ketone 200 parts-Tetrahydrofuran 50 parts-Illustrative compound (1) as an infrared absorber 3.2 parts-Sodium hydroxide aqueous solution (0.3N) 0.1 part The mixture was put into a 1000 ml separable flask, heated at 70 ° C., and stirred by a three-one motor (manufactured by Shinto Kagaku Co., Ltd.) to prepare a mixed solution. While further stirring this mixed liquid, 410 parts of ion-exchanged water was gradually added for phase inversion emulsification, and then the solvent was removed to obtain an infrared absorbent-containing resin particle dispersion (1) (solid content 30%). It was.
Thereafter, the infrared absorbent-containing resin particle dispersion (1) was freeze-dried to obtain infrared absorbent-containing resin particles (1) having a volume average particle diameter of 300 nm.

[Preparation of core particle (1)]
260 parts of first resin particle dispersion 20 parts of second resin particle dispersion 32.7 parts of colorant dispersion (C) 70 parts of release agent dispersion (P) Cationic surfactant ( Sanisol B50 manufactured by Kao Co., Ltd. 1.5 parts, 0.36 parts of polyaluminum chloride, 1000 parts of ion-exchanged water The above materials are housed in a round stainless steel flask, and a homogenizer (Ultra Turrax T50 manufactured by IKA) is used. After mixing and dispersing, the mixture was heated to 48 ° C. with stirring. After maintaining at 48 ° C. for 30 minutes, it was confirmed with an optical microscope that aggregated particles were formed. Thereafter, the pH of the solution was adjusted to 8.0 with an aqueous sodium hydroxide solution having a concentration of 0.5 mol / L, and then heated to 90 ° C. and further stirred for 3 hours.
After completion of the reaction, the reaction mixture was cooled and subjected to solid-liquid separation by Nutsche suction filtration. The solid content was redispersed in 1000 parts of ion-exchanged water at 30 ° C., stirred for 15 minutes at 300 rpm with a stirring blade, and subjected to solid-liquid separation by Nutsche suction filtration. This redispersion and suction filtration were repeated, and the washing was terminated when the filtrate had an electric conductivity of 10.0 μS / cmt or less. Next, vacuum drying was performed for 12 hours to obtain core particles (1) having a volume average particle diameter of 5.8 μm.

[Production of Toner Particles (1)]
95 parts of the core particles (1) and 5 parts of the infrared absorbent-containing resin particles (1) are stirred at 6500 rpm for 20 minutes using a sample mill, and the infrared absorbent-containing resin particles (1 ) To form a film. Thus, toner particles (1) having a volume average particle diameter of 5.9 μm were obtained.

[Preparation of External Toner (1)]
100 parts of toner particles (1) and 1 part of hydrophobic silica (T805, manufactured by Nippon Aerosil Co., Ltd.) are mixed, stirred for 10 minutes at a peripheral speed of 32 m / sec using a Henschel mixer, and then used with a 45 μm mesh sieve. Coarse particles were removed to obtain externally added toner (1).

[Preparation of Developer (1)]
94 parts of the carrier and 6 parts of the externally added toner (1) were stirred for 20 minutes at 40 rpm using a V blender, and then sieved with a 177 μm mesh sieve to obtain developer (1).

<Examples 2 to 9>
In Example 1, the infrared absorber containing resin particle was prepared using the exemplary compound of Table 1 instead of the exemplary compound (1) as an infrared absorber. Then, the toner particles (2) to (9) are prepared by changing the mixing ratio of the core particles (1) and the respective infrared absorber-containing resin particles as shown in Table 1, and the externally added toners (2) to (9) (9) and developers (2) to (9) were prepared.
The mixing amount of the infrared absorbent-containing resin particles was determined for each example by calculating the addition amount at which the absorption of the laser beam was almost equal from the absorption intensity of the tetrahydrofuran solution of the infrared absorbing agent.

<Example 10>
[Production of Toner Particles (10)]
In Example 1, an infrared absorbent-containing resin particle was prepared using a styrene-acrylic resin (styrene-butyl acrylate copolymer, weight average molecular weight 50,000) instead of the polyester resin (1) as a binder resin. Toner particles (10) were prepared, and externally added toner (10) and developer (10) were prepared.

<Example 11>
[Production of Toner Particles (11)]
3rd resin particle dispersion 263 parts Colorant dispersion (C) 30.7 parts Release agent dispersion (P) 70 parts Polyaluminum chloride 0.3 parts The above material is a round stainless steel flask The mixture was mixed and dispersed with a homogenizer (Ultra Turrax T50 manufactured by IKA). Next, 0.15 part of polyaluminum chloride was added thereto, and the dispersing operation was continued with the homogenizer. The flask was heated to 47 ° C. with stirring in an oil bath for heating, and maintained at this temperature for 60 minutes, and then 21 parts of the infrared absorbent-containing resin particle dispersion (1) in Example 1 was gently added thereto. . Thereafter, the pH of the system was adjusted to 5.4 with a 0.5 mol / L sodium hydroxide aqueous solution, and then the stainless steel flask was sealed and heated to 96 ° C. while continuing to stir using a magnetic seal, for 2 hours. Retained.
After completion of the reaction, the reaction mixture was cooled to room temperature, the solid was separated by filtration, thoroughly washed with ion exchange water, and then subjected to solid-liquid separation by Nutsche suction filtration. This was further redispersed in 3 L of ion exchanged water at 40 ° C., and washed by stirring at 300 rpm for 15 minutes. This was further repeated 5 times, and when the pH of the filtrate reached 7.01, it was removed by filtration and vacuum-dried for 12 hours to obtain toner particles (11) having a volume average particle diameter of 5.7 μm.

[Preparation of External Toner (10)]
100 parts of toner particles (11) and 1 part of hydrophobic silica (T805 manufactured by Nippon Aerosil Co., Ltd.) are mixed and stirred for 10 minutes at a peripheral speed of 32 m / sec using a Henschel mixer, and then a sieve sieve of 45 μm is used. Coarse particles were removed to obtain externally added toner (11).

[Production of Developer (11)]
94 parts of the carrier and 6 parts of the external toner (11) were stirred for 20 minutes at 40 rpm using a V blender, and then sieved with a 177 μm mesh sieve to obtain developer (11).

<Comparative Examples 1-6>
In Example 1, infrared absorber-containing resin particles were prepared using compounds (H-1) to (H-6) having the following structural formulas instead of the exemplified compound (1) as the infrared absorber. Then, the toner particles (C1) to (C6) are prepared by changing the mixing ratio of the core particles (1) and the respective infrared absorber-containing resin particles as shown in Table 1, and the externally added toners (C1) to (C1) to (C6) and developers (C1) to (C6) were prepared.
The mixing amount of the infrared absorbent-containing resin particles was determined for each comparative example by calculating the addition amount at which the absorption of the laser beam was almost equal from the absorption intensity of the tetrahydrofuran solution of the infrared absorbing agent.

The maximum absorption wavelength (λ _max ) of the compounds (H-1) to (H-6) in tetrahydrofuran is as follows. Compound (H-1): λ _max 813 nm, Compound (H-2): λ _max 813 nm, Compound (H-3): λ _max 813 nm, Compound (H-4): λ _max 865 nm, Compound (H-5) : Λ _max 910 nm, compound (H-6): λ _max 847 nm.

<Evaluation>
An electrophotographic image forming apparatus (Docu Center Color 2220 manufactured by Fuji Xerox Co., Ltd.) is prepared, and the laser beam of the optical fixing device is set to the wavelength shown in Table 1 (laser element wavelength close to the maximum absorption wavelength of each infrared absorber). The irradiation energy was set to 1.5 J / cm ² and an image was formed on the paper using each developer. The following evaluation was performed about the obtained image. The results are shown in Table 1.

[Fixability]
When the image was visually observed and a good fixed image was obtained without image blurring, the following crease evaluation was performed and the fixing property was determined according to the following criteria.
-Crease evaluation-
The paper on which the image was formed was folded once, opened, the folded image portion was wiped with cotton, and the image width (μm) that was whitened was measured to obtain a crease value. The allowable value was a crease value of 40 or less.
-Criteria-
A: A good fixed image is obtained, and the crease value is 40 or less.
B: A good fixed image was obtained, but the crease value exceeded 40.
C: The part which does not fix is seen a little, and a crease value exceeds 40.
D: Many portions are not fixed, and a good fixed image cannot be obtained.

[Muddy]
A toner and a developer were prepared in the same manner as in Example 1 except that the infrared absorber was removed, and an image was formed on paper using this developer. At this time, instead of fixing with the optical fixing device, the paper onto which the toner has been transferred is sandwiched between Teflon (registered trademark) sheets, and passed through a pouch laminator (GLM 2500, Nippon CBC, speed setting 1, temperature setting 120 ° C.). I got an image.
On the other hand, using the developers of the respective examples and comparative examples, the irradiation energy of the optical fixing device was set to 1.0 J / cm ² and an image was formed on paper.
For each fixed image, the L ^* value, a ^* value, and b ^* value in the CIE 1976 L ^* a ^* b ^* color system were measured using a reflection spectral densitometer (X-Rite 939 manufactured by X-Rite Co., Ltd.). A color difference ΔE was calculated based on the equation, and color turbidity was determined according to the following criteria.

L ₁ , a ₁ , and b ₁ are L ^* values, a ^* values, and b ^* values of an image of a toner that does not contain an infrared absorber, and L ₂ , a ₂ , and b ₂ are the examples and comparisons. The L ^* value, a ^* value, and b ^* value of the toner image in the example.

-Criteria-
A: Color difference ΔE is less than 3 B: Color difference ΔE is 3 or more and less than 6 C: Color difference ΔE is 6 or more and less than 10 D: Color difference ΔE is 10 or more

  As shown in Table 1, this example was excellent in photofixability and suppressed color turbidity.

312Y, 312M, 312C, 312K Image forming units 314Y, 314M, 314C, 314K Photoconductors 316Y, 316M, 316C, 316K Chargers 318Y, 318M, 318C, 318K Exposure units 320Y, 320M, 320C, 320K Developers 322Y, 322M, 322C, 322K Cleaner 324Y, 324M, 324C, 324K Transfer device 326 Optical fixing device 328 Paper feed roller P Recording medium

Claims (8)

A core containing a binder resin;
A coating layer containing a binder resin and an infrared absorber represented by the following general formula (1), covering the core;
An electrostatic charge image developing toner comprising toner particles having the following.

In general formula (1), R ¹ and R ² each independently represent a saturated hydrocarbon group, provided that the total number of carbon atoms of R ¹ and R ² is 6 or more and 12 or less. R ³ represents a hydrogen atom or an alkyl group. X represents an oxygen atom or a sulfur atom.   The electrostatic image developing toner according to claim 1, wherein the binder resin contained in the coating layer is a polyester resin.   The electrostatic image developing toner according to claim 1, wherein the core portion further contains a colorant.   An electrostatic charge image developer comprising the electrostatic charge image developing toner according to claim 1. An electrostatic charge image developing toner according to any one of claims 1 to 3 is accommodated,
A toner cartridge to be attached to and detached from the image forming apparatus. A developing means for containing the electrostatic charge image developer according to claim 4 and developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer,
A process cartridge attached to and detached from the image forming apparatus. An image carrier,
Charging means for charging the surface of the image carrier;
An electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged image carrier;
Development means for containing the electrostatic charge image developer according to claim 4 and developing the electrostatic charge image formed on the surface of the image carrier as a toner image by the electrostatic charge image developer;
Transfer means for transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
Fixing means for fixing the toner image by irradiating the toner image transferred onto the surface of the recording medium with light including infrared rays;
An image forming apparatus comprising: A charging step for charging the surface of the image carrier;
An electrostatic charge image forming step of forming an electrostatic charge image on the surface of the charged image carrier;
A developing step of developing an electrostatic charge image formed on the surface of the image carrier as a toner image with the electrostatic charge image developer according to claim 4;
A transfer step of transferring a toner image formed on the surface of the image carrier to the surface of a recording medium;
A fixing step of fixing the toner image by irradiating the toner image transferred onto the surface of the recording medium with light including infrared rays;
An image forming method comprising: