JP2011070001A - Electrophotographic toner and method for producing the same, electrophotographic developer, toner cartridge, process cartridge, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide electrophotographic toner, which suppresses offset of an image. <P>SOLUTION: The electrophotographic toner comprises: a release agent where an endothermic peak measured by a differential scanning calorimeter (DSC) is in the range from 70°C to 95°C and a half value width of the endothermic peak is in the range from 10°C to 18°C; a crystalline polyester resin; an amorphous polyester resin; and a colorant. The toner has a complex elastic modulus of 5×10<SP>4</SP>to 5×10<SP>5</SP>Pa at 80°C. The release agent in the toner has a dispersion diameter of 0.3 to 0.8 μm in terms of a particle diameter (D50) corresponding to 50% in an undersize cumulative distribution based on a measurement by numbers, and 1.1 μm or less in terms of a particle diameter (D84) corresponding to 84% in the undersize cumulative distribution based on the measurement by numbers. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electrophotographic toner and a manufacturing method thereof, an electrophotographic developer, a toner cartridge, a process cartridge, and an image forming apparatus.

  In electrophotographic image formation, generally, a latent image is electrically formed on the surface of a photoconductor (latent image holder) using a photoconductive substance by various means, and the formed latent image is converted into a latent image. After developing with toner to form a toner image, the toner image is transferred to the surface of a transfer medium such as paper via an intermediate transfer body as necessary, and heated, pressurized, heated and pressurized, or a solvent. It is carried out through a plurality of steps of fixing with steam or the like. Further, the toner remaining on the surface of the photoreceptor is cleaned by various methods as necessary, and is used again for developing the toner image.

  As the developer, there are a two-component developer containing a toner and a carrier and a one-component developer using a magnetic toner or a non-magnetic toner alone. Conventionally, a so-called melt-kneading pulverization method in which a thermoplastic resin, a colorant, and a release agent are melt-kneaded, finely pulverized after cooling, and further classified is used.

  In recent years, in addition to the increase in image quality required for electrophotography and the increase in process speed, there has been a strong demand for energy saving in production processes from the viewpoint of environmental considerations. For this reason, studies have been actively made from the viewpoints of productivity and low-temperature fixability with respect to the reduction in toner particle size, the increase in speed, and energy saving for high image quality.

  In order to provide an electrophotographic toner with little occurrence of image unevenness, excellent releasability, and stable chargeability, in an electrophotographic toner comprising at least a release agent, a resin and a colorant, the release Broad melting wax and DSC having an endothermic peak of 75 to 100 ° C., an endothermic peak half-value width of 10 to 40 ° C., an exothermic peak of 70 to 100 ° C., and an exothermic peak half-value width of 10 to 40 ° C. A sharp melting wax having a measured endothermic peak of 60 to 90 ° C., an endothermic peak half-width of 5 ° C. or less, an exothermic peak of 55 to 80 ° C., and an exothermic peak half-width of 5 ° C. or less, and its mixed composition ratio is broad An electrophotographic toner is disclosed in which molten wax / sharp molten wax = 9/1 to 2/8 and the resin has a polar group (example) If, see Patent Document 1.).

In addition, in order to provide a toner for developing an electrostatic charge image having excellent fixability at low temperatures and offset resistance, the toner for developing an electrostatic charge image contains at least a binder resin and a wax. A synthetic hydrocarbon obtained by using a catalyst from a synthesis gas composed of carbon oxide and hydrogen, or a synthetic hydrocarbon obtained by hydrogenation of these, with a weight average molecular weight / number average molecular weight (Mw / Mn) of 1. 45 or less, and in the DSC curve measured by the differential scanning calorimeter, the difference T (° C.) between the onset temperature at the end point of the endothermic peak at the time of temperature rise and the onset temperature of the endothermic peak satisfies the following formula. An electrostatic charge image developing toner is disclosed (for example, see Patent Document 2).
10 ≦ T ≦ 50

  Furthermore, in order to provide a toner having excellent fixability, a toner having a resin composition containing a binder resin and wax A, wherein the wax A contains 92% by mass or more of n (normal) -paraffin. Containing a plurality of n-paraffin components having different carbon numbers, the peak end temperature of the maximum endothermic peak in the endothermic curve measured by DSC is 75 to 90 ° C., and the peak half-value width of the maximum endothermic peak Has disclosed a toner having a temperature of 12 ° C. or lower (see, for example, Patent Document 3).

Japanese Patent No. 4189516 Japanese Patent No. 3885090 Patent No. 3943791

  An object of the present invention is to provide an electrophotographic toner in which set-off (blocking) of a fixed image is suppressed.

That is, in the invention according to claim 1, the endothermic peak obtained by a differential scanning calorimeter (DSC) is in the range of 70 ° C. or higher and 95 ° C. or lower, and the half width of the endothermic peak is 10 ° C. or higher and 18 ° C. or lower. A release agent in the range of, a crystalline polyester resin, an amorphous polyester resin, and a colorant,
The complex elastic modulus at 80 ° C. is 5 × 10 ⁴ Pa or more and 5 × 10 ⁵ Pa or less,
The dispersion diameter of the release agent in the toner is 0.3 μm or more and 0.8 μm or less as a particle size (D50) that is 50% in the cumulative distribution under sieve based on the number measurement, and the cumulative distribution under sieve based on the number measurement. This is an electrophotographic toner having a particle size (D84) of 84% at 1.1 μm or less.

  The invention according to claim 2 is the electrophotographic toner according to claim 1, wherein the release agent is paraffin wax having a normal hydrocarbon ratio of 80% by mass or more.

In the invention according to claim 3, the endothermic peak obtained by a differential scanning calorimeter (DSC) is in the range of 70 ° C. or higher and 95 ° C. or lower, and the half width of the endothermic peak is in the range of 10 ° C. or higher and 18 ° C. or lower. A release agent dispersion in which the release agent is dispersed, a crystalline polyester resin dispersion in which a crystalline polyester resin is dispersed, an amorphous polyester resin dispersion in which an amorphous polyester resin is dispersed, and a colorant are dispersed. An agglomerated particle dispersion preparing step of mixing a colorant dispersion to prepare a dispersion of aggregated particles containing the release agent, the crystalline polyester resin, the amorphous polyester resin, and the colorant;
The toner for electrophotography according to claim 1, further comprising a fusing / merging step of fusing and coalescing the aggregated particles by heating to an endothermic peak temperature of ± 10 ° C. of the release agent. Is the method.

  A fourth aspect of the present invention is an electrophotographic developer containing the electrophotographic toner according to the first or second aspect.

  The invention according to claim 5 is a toner cartridge that contains at least toner, and the toner is the electrophotographic toner according to claim 1 or 2.

  The invention according to claim 6 is a process cartridge including at least a developer holder and containing the electrophotographic developer according to claim 4.

  The invention according to claim 7 is formed on the photosensitive member, a charging unit that charges the photosensitive member, an electrostatic charge image forming unit that forms an electrostatic charge image on the surface of the charged photosensitive member, and the photosensitive member. 5. A developing unit that develops the electrostatic image as a toner image with the electrophotographic developer according to claim 4, a transfer unit that transfers the toner image onto a transfer target, and a fixing unit that fixes the toner image. And an image forming apparatus.

  According to the first aspect of the present invention, there is provided an electrophotographic toner in which set-off of a fixed image is suppressed.

  According to the second aspect of the present invention, there is provided an electrophotographic toner that is excellent in rubbing property as compared with the case where a release agent other than paraffin wax having a normal hydrocarbon ratio of 80% by mass or more is used. .

  According to the third aspect of the invention, an electrophotographic toner is produced in which set-off of a fixed image is suppressed.

  According to the fourth aspect of the present invention, there is provided an electrophotographic developer in which set-off of a fixed image is suppressed.

  According to the fifth aspect of the present invention, there is provided a toner cartridge that facilitates the supply of electrophotographic toner that suppresses the set-off of a fixed image.

  According to the sixth aspect of the present invention, it is possible to facilitate the handling of the electrophotographic developer in which the set-off of the fixed image is suppressed, and the adaptability to the image forming apparatus having various configurations can be enhanced.

  According to the seventh aspect of the present invention, there is provided an image forming apparatus in which set-off of a fixed image is suppressed.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment. It is a schematic block diagram which shows an example of the process cartridge which concerns on this embodiment.

  Hereinafter, embodiments of an electrophotographic toner and a manufacturing method thereof, an electrophotographic developer, a toner cartridge, a process cartridge, and an image forming apparatus according to the present invention will be described in detail.

<Toner for electrophotography>
The electrophotographic toner according to the present embodiment (hereinafter sometimes simply referred to as “toner”) has an endothermic peak determined by a differential scanning calorimeter (DSC) in the range of 70 ° C. or more and 95 ° C. or less. In addition, the complex elastic modulus at 80 ° C. includes a release agent having a half width of the endothermic peak in the range of 10 ° C. to 18 ° C., a crystalline polyester resin, an amorphous polyester resin, and a colorant. 5 × 10 ⁴ Pa or more and 5 × 10 ⁵ Pa or less, and the dispersion diameter of the release agent in the toner is 0.3 μm or more as a particle diameter (D50) that is 50% in the cumulative distribution under sieve based on the number measurement. It is 0.8 μm or less, and is 1.1 μm or less as a particle size (D84) of 84% in the cumulative distribution under sieve based on the number measurement.

  In this embodiment, the endothermic peak is measured by DSC in accordance with ASTM D3418-8, using a differential scanning calorimeter (manufactured by Mac Science: DSC3110, thermal analysis system 001), and from room temperature (25 ° C.) to 150 ° C. Up to 10 ° C./min.

Further, the dispersion diameter (D16, D50, D84) of the release agent in the toner was determined by the following method.
The toner was embedded in an epoxy resin, frozen with a cryostat, cut into a thin film, and the cross section of the toner was observed with an electron microscope in a transmission mode. From the obtained toner cross-sectional observation photograph (10,000 times), 20 toners were randomly selected, and the dispersion diameters (D16, D50, D84) of the release agent were measured with an image analyzer. The average diameter was taken as the dispersion diameter when there was a difference between the major axis and minor axis.

  In order to improve the reliability of the printed materials used in the printing market such as DTP (desktop publishing) and CTP (computer to plate), the coating condition of the release agent on the fixed image surface is made uniform, and the strength of the release agent is further increased. Thus, there is a demand for a technique that improves the rubbing strength of a fixed image and provides a highly reliable printed image. In addition, there is a need for a technique for preventing a fixed image from being reversed.

  In this embodiment, the dispersion diameter of the release agent in the toner is set to 0.3 μm or more and 0.8 μm or less as a particle diameter (D50) that is 50% in the cumulative distribution under sieve based on the number measurement, and based on the number measurement. The particle diameter (D84) of 84% in the integrated distribution under the sieve is 1.1 μm or less. As a result, the release agent is uniformly dispersed in the toner.

In the present embodiment, the endothermic peak obtained by a differential scanning calorimeter (DSC) is in the range of 70 ° C. or higher and 95 ° C. or lower, and the half width of the endothermic peak is in the range of 10 ° C. or higher and 18 ° C. or lower. A mold release agent is used.
The wider the half-value width of the endothermic peak of the release agent, the wider the molecular weight distribution of the release agent. The broad molecular weight distribution of the release agent indicates that the release agent is a mixture of a release agent component having a low molecular weight and a low melting temperature and a release agent component having a high molecular weight and a high melting temperature. . The mold release agent used in the present embodiment has a half-value width of the endothermic peak of the mold release agent in the range of 10 ° C. or more and 18 ° C. or less, and therefore, a mold release in which a low molecular weight component and a high molecular weight component are appropriately mixed. It is an agent.

  The low molecular weight component of the release agent tends to ooze out on the fixed image surface. Further, as described above, the release agent is uniformly dispersed in the toner. Therefore, the release agent is present uniformly on the fixed image surface. Moreover, the high molecular weight component of the release agent is excellent in terms of strength. As a result, it is assumed that the slidability and strength of the fixed image surface are improved, and the rubability of the fixed image is improved. Further, it is presumed that the improvement of the rubbing property prevents peeling and set-off of the fixed image and improves the reliability of the image. Furthermore, since the release agent is uniformly present in the toner, the amount of the release agent required in the toner is kept to a minimum, and the generation of streaks on the fixed image due to the release agent is suppressed, thereby fixing the toner. It is assumed that the image quality is improved.

  In addition, since the half-value width of the endothermic peak is in the range of 10 ° C. or more and 18 ° C. or less, the release agent used in this embodiment is likely to be in a semi-molten state when fixing the toner image. Therefore, after the toner image is thermally fixed by the uniform dispersion of the release agent in the toner and the semi-molten state of the release agent, the crystalline polyester resin and the amorphous polyester resin are cooled during cooling. It is presumed that by preventing excessive compatibilization, image solidification is accelerated, and settling (blocking) at the time of discharging a fixed image is suppressed.

In this embodiment, “low-temperature fixing” refers to fixing a toner by heating it at about 165 ° C. or less under the conditions described below.
conditions:
-Teflon (registered trademark) hard roll heat fixing device (Fuji Xerox DCF1100 fixing device)
・ Heating time by nip: 21msec
・ Nip surface pressure: 6.0 kgf / cm ²
・ Fixing speed 535mm / sec
・ Paper Business 80 (basis weight 80g / m ² )
-Solid image with an image toner amount of 5.0 g / m ^2- Fixability determination The temperature at which the width of the unfolded sheet is less than 0.5 m is the minimum fixing temperature. The minimum fixing temperature of the toner not containing the crystalline polyester resin is about 180 ° C., and the low-temperature fixing property is not sufficient.

The complex elastic modulus at 80 ° C. of the toner according to the exemplary embodiment needs to be 5 × 10 ⁴ Pa or more and 5 × 10 ⁵ Pa or less. When the complex elastic modulus is less than 5 × 10 ⁴ Pa, the cooling and solidification is slow when the print is discharged after fixing the image, which may cause an image blocking problem. On the other hand, if the complex elastic modulus exceeds 5 × 10 ⁵ Pa, there may be a problem in low-temperature fixability. The complex elastic modulus at 80 ° C. of the toner of the exemplary embodiment may be 5 × 10 ⁴ Pa or more and 4 × 10 ⁵ Pa or less, or 5 × 10 ⁴ Pa or more and 3 × 10 ⁵ Pa or less.
In the present embodiment, the complex elastic modulus of the toner is a value measured by the following method.
Specifically, a temperature rise measurement is performed using a rheometer (manufactured by Rheometric Scientific: ARES rheometer) under the condition of a frequency of 1 Hz using a parallel plate. More specifically, a sample is set at a temperature of 120 ° C. to 140 ° C., cooled to room temperature (25 ° C.), and then heated at a rate of temperature increase of 1 ° C./min. The storage elastic modulus, loss elastic modulus, complex elastic modulus, and tan δ at the time of temperature increase are measured for each ° C. The complex elastic modulus of the toner was measured with the upper limit of strain being 20%.

When the dispersion diameter D50 in the toner of the release agent according to the present embodiment is less than 0.3 μm, the dispersion in the toner is uniform, but the amount of the release agent exuded at the time of fixing and melting is not sufficient. There may be a problem that the image cannot be sufficiently covered. On the other hand, if D50 exceeds 0.8 μm, the amount of the release agent that leaks out during fixing and melting may become non-uniform, resulting in a problem that uniform coating is not possible. In this embodiment, the value of D50 is preferably 0.4 μm or more and 0.8 μm or less, and more preferably 0.45 μm or more and 0.7 μm nm or less.
Further, when the dispersion diameter D84 of the release agent according to the present embodiment exceeds 1.1 μm, the amount of the exudation becomes non-uniform, which may cause a problem that it cannot be uniformly coated. In the present embodiment, the value of D84 is desirably 0.9 μm or less.
In the present embodiment, the particle size (D16) that is 16% in the cumulative distribution under sieving based on the number measurement may be 0.2 μm or more.

  The toner according to the exemplary embodiment includes a specific release agent, a crystalline polyester resin, an amorphous polyester resin, a colorant, and other additives used as necessary. Hereinafter, each component constituting the toner of the exemplary embodiment will be described in detail.

-Release agent-
The mold release agent used in this embodiment has an endothermic peak determined by a differential scanning calorimeter (DSC) in the range of 70 ° C. or higher and 95 ° C. or lower, and the half width of the endothermic peak is 10 ° C. or higher and 18 ° C. It is a mold release agent in the following range.
Specific examples of the release agent include low molecular weight polypropylene, low molecular weight polyethylene, paraffin wax, microcrystalline wax; silicone resin; rosins; rice wax; carnauba wax;
Among these, it is desirable to use a paraffin wax having a normal hydrocarbon ratio of 80% by mass or more. It is estimated that the higher the ratio of normal hydrocarbons, the faster the crystallization and the more effective the blocking.

The ratio of normal hydrocarbons contained in the release agent is measured by the following method.
The n-paraffin content can be quantified from a retention time and a peak area obtained from a known n-paraffin standard substance using a gas chromatograph such as GC-17A manufactured by Shimadzu Corporation.

Measurement conditions / column Liquid phase: Dimethylsiloxane
Film thickness: 0.25 μm, inner diameter × length = 0.25 mm × 15 m
・ Detector FID
・ Carrier gas Helium
・ Sample preparation 0.1% by mass (using heptane as solvent)
-Temperature condition column thermostat The temperature was raised from an initial temperature of 60 ° C to 445 ° C in 30 minutes and held at 445 ° C for 5 minutes.
Vaporizing chamber The initial temperature was raised from 70 ° C to 445 ° C in 90 seconds and maintained at 445 ° C for 10 seconds.

Measurement / Analysis An n-paraffin standard having about 20 to 40 carbon atoms is measured to obtain a retention time and a peak area according to the carbon number of the n-paraffin. Absorption occurring during the retention time according to the carbon number of n-paraffin is defined as a non-normal component. The measured value of the release agent sample is integrated by dividing it into a normal paraffin component and a non-normal component, and the n-paraffin content ratio (Sn = (Sa-Si) / Sa ×) from the total area Sa and the area Si obtained from the non-normal component. 100 (%)).

  The content of the release agent in the toner is preferably 3% by mass or more and 15% by mass or less, and more preferably 5% by mass or more and 12% by mass or less. If the content of the release agent is less than 3% by mass, there is a risk of peeling failure particularly in oilless fixing. When the content of the release agent is more than 15% by mass, the fluidity of the toner may be deteriorated and the image quality and the reliability of image formation may be deteriorated. Excessive wax may cause the image gloss to become cloudy or uneven, and reduce image quality.

-Crystalline polyester resin-
The melting temperature of the crystalline polyester resin used in this embodiment is preferably in the range of 50 ° C. or higher and 100 ° C. or lower, more preferably in the range of 55 ° C. or higher and 90 ° C. or lower, from the storage and low temperature fixability. It is further desirable that the temperature be in the range of 60 ° C or higher and 85 ° C or lower. When the melting temperature is lower than 50 ° C., toner storage properties such as blocking of the stored toner and storage properties of the fixed image after fixing may become difficult. Further, when the melting temperature exceeds 100 ° C., sufficient low-temperature fixability may not be obtained.
The melting temperature of the crystalline polyester resin was determined as the peak temperature of the endothermic peak obtained by the differential scanning calorimetry (DSC).

  In the present embodiment, the “crystalline polyester resin” includes not only a polymer having a 100% polyester structure as a constituent component but also a polymer (copolymer) obtained by polymerizing a component constituting a polyester and other components. means. However, in the latter case, the component other than the polyester constituting the polymer (copolymer) is 50% by mass or less.

  The crystalline polyester resin used in the toner of this embodiment is synthesized from, for example, a polyvalent carboxylic acid component and a polyhydric alcohol component. In the present embodiment, a commercially available product may be used as the crystalline polyester resin, or a synthesized product may be used.

  Examples of the polyvalent carboxylic acid component include oxalic acid, succinic acid, glutaric acid, adipic acid, peric acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12 -Aliphatic dicarboxylic acids such as dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid; phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, mesaconic acid Aromatic dicarboxylic acids such as dibasic acids such as, and the like, and anhydrides and lower alkyl esters thereof are also included, but not limited thereto.

  Examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and the like, and anhydrides thereof. And lower alkyl esters. These may be used individually by 1 type and may use 2 or more types together.

Moreover, as said acid component, the said aliphatic dicarboxylic acid and aromatic dicarboxylic acid may be contained.
Furthermore, in addition to the aliphatic dicarboxylic acid and aromatic dicarboxylic acid, a dicarboxylic acid component having a double bond may be contained.

  As the polyhydric alcohol component, an aliphatic diol is preferable, and a linear aliphatic diol having a main chain portion having 7 to 20 carbon atoms is more desirable. When the aliphatic diol is branched, the crystallinity of the polyester resin is lowered and the melting temperature may be lowered. Further, when the main chain portion has less than 7 carbon atoms, when the polycondensation with the aromatic dicarboxylic acid is performed, the melting temperature becomes high and low temperature fixing may be difficult. On the other hand, when the number of carbons in the main chain portion exceeds 20, it is difficult to obtain practical materials. The number of carbon atoms in the main chain portion is more preferably 14 or less.

  Specific examples of the aliphatic diol suitably used for the synthesis of the crystalline polyester used in the toner of the exemplary embodiment include 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, 1,14-eicosandecanediol and the like are exemplified, but not limited thereto. Among these, considering availability, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are desirable.

  Examples of the trivalent or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like. These may be used individually by 1 type and may use 2 or more types together.

  Among the polyhydric alcohol components, the content of the aliphatic diol is preferably 80 mol% or more, and more preferably 90% or more. When the content of the aliphatic diol is less than 80 mol%, the crystallinity of the polyester resin is lowered and the melting temperature is lowered, so that toner blocking resistance, image storage stability, and low-temperature fixability may be deteriorated. .

  If necessary, a polycarboxylic acid or a polyhydric alcohol may be added at the final stage of the synthesis for the purpose of adjusting the acid value or the hydroxyl value. Examples of polycarboxylic acids include aromatic carboxylic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, naphthalenedicarboxylic acid; maleic anhydride, fumaric acid, succinic acid, alkenyl Aliphatic carboxylic acids such as succinic anhydride and adipic acid; and alicyclic carboxylic acids such as cyclohexanedicarboxylic acid.

  Examples of polyhydric alcohols include aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, glycerin; cyclohexanediol, cyclohexanedimethanol, hydrogenated bisphenol A, etc. And aromatic diols such as bisphenol A ethylene oxide adduct and bisphenol A propylene oxide adduct.

The production of the crystalline polyester resin can be carried out at a polymerization temperature of 180 ° C. or higher and 230 ° C. or lower. If necessary, the reaction system is reduced in pressure and reacted while removing water and alcohol generated during condensation. .
When the polymerizable monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point may be added as a solubilizer and dissolved. In the polycondensation reaction, the dissolution auxiliary solvent is distilled off. If there is a polymerizable monomer having poor compatibility in the copolymerization reaction, the polymerizable monomer having poor compatibility and the polymerizable monomer and the acid or alcohol to be polycondensed are condensed in advance. And then polycondensation with the main component.

  Catalysts used in the production of the polyester resin include alkali metal compounds such as sodium and lithium; alkaline earth metal compounds such as magnesium and calcium; zinc, manganese, antimony, titanium, tin, zirconium, germanium and the like Metal compounds; phosphorous acid compounds; phosphoric acid compounds; and amine compounds.

  Specifically, sodium acetate, sodium carbonate, lithium acetate, lithium carbonate, calcium acetate, calcium stearate, magnesium acetate, zinc acetate, zinc stearate, zinc naphthenate, zinc chloride, manganese acetate, manganese naphthenate, titanium tetraethoxy , Titanium tetrapropoxide, titanium tetraisopropoxide, titanium tetrabutoxide, antimony trioxide, triphenylantimony, tributylantimony, tin formate, tin oxalate, tetraphenyltin, dibutyltin dichloride, dibutyltin oxide, diphenyltin oxide, zirconium tetra Butoxide, Zirconium naphthenate, Zirconyl carbonate, Zirconyl acetate, Zirconyl stearate, Zirconyl octylate, Germanium oxide, Trif Alkenyl phosphite, tris (2,4-di -t- butyl-phenyl) phosphite, ethyltriphenylphosphonium bromide, triethylamine, compounds such as triphenyl amine.

  The acid value of the crystalline polyester resin used in the present embodiment (the number of mg of KOH required to neutralize 1 g of resin) is preferably in the range of 3.0 mgKOH / g to 30.0 mgKOH / g, It is more preferably in the range of 6.0 mgKOH / g or more and 25.0 mgKOH / g or less, and further preferably in the range of 8.0 mgKOH / g or more and 20.0 mgKOH / g or less.

  When the acid value is lower than 3.0 mgKOH / g, the dispersibility in water is lowered, and thus it may be very difficult to produce emulsified particles by a wet process. Further, since stability as emulsified particles during aggregation is significantly reduced, it may be difficult to produce an efficient toner. On the other hand, when the acid value exceeds 30.0 mgKOH / g, the hygroscopicity as a toner increases and the toner may be easily affected by the environment.

  The crystalline polyester resin preferably has a weight average molecular weight (Mw) of 6,000 or more and 35,000 or less. When the molecular weight (Mw) is less than 6,000, the toner may permeate the surface of a recording medium such as paper at the time of fixing to cause fixing unevenness, or the strength of the fixed image against bending resistance may be reduced. On the other hand, when the weight average molecular weight (Mw) exceeds 35,000, the viscosity at the time of melting becomes too high, and the temperature for reaching a viscosity suitable for fixing may be increased, resulting in the deterioration of the low-temperature fixability. There is a case.

  The weight average molecular weight is measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC was performed with a THF solvent using a Tosoh column / TSKgel Super HM-M (15 cm) using a Tosoh GPC / HLC-8120 as a measuring device. The weight average molecular weight is calculated from the measurement result using a molecular weight calibration curve prepared with a monodisperse polystyrene standard sample.

  The content of the crystalline polyester resin in the toner is preferably in the range of 3% by mass to 40% by mass, more preferably in the range of 4% by mass to 35% by mass, and still more preferably in the range of 5% by mass or more. The range is 30% by mass or less. When the content of the crystalline polyester resin is less than 3% by mass, sufficient low-temperature fixability may not be obtained. When the content is more than 40% by mass, sufficient toner strength and fixed image strength cannot be obtained. There is a case where an adverse effect on the charging property is also caused.

  As the crystalline polyester resin, a crystalline polyester resin synthesized using an aliphatic polymerizable monomer (hereinafter sometimes referred to as “crystalline aliphatic polyester resin”) as a main component (50% by mass or more) It is desirable to do. Furthermore, in this case, the constituent ratio of the aliphatic polymerizable monomer constituting the crystalline aliphatic polyester resin is preferably 60 mol% or more, and more preferably 90 mol% or more. As the aliphatic polymerizable monomer, the above-mentioned aliphatic diols and dicarboxylic acids are preferably used.

  In the present embodiment, other crystalline resins other than the crystalline polyester resin may be used in combination. Examples of other crystalline resins include polyalkylene resins and long-chain alkyl (meth) acrylate resins.

-Amorphous polyester resin-
In this embodiment, an amorphous polyester resin is used. By using an amorphous polyester resin, the compatibility with the crystalline polyester resin is improved, so that the amorphous polyester resin is also reduced in viscosity as the melting temperature of the crystalline polyester resin is lowered, and as a toner Therefore, it is advantageous for low temperature fixability. In addition, since the wettability with the crystalline polyester resin is good, the dispersibility of the crystalline polyester resin inside the toner is improved, and the exposure of the crystalline polyester resin to the toner surface is suppressed. Is suppressed. For this reason, it is also desirable from the viewpoint of improving the strength of the toner and the strength of the fixed image.

The amorphous polyester resin desirably used in the present embodiment is obtained, for example, by condensation polymerization of polyvalent carboxylic acids and polyhydric alcohols.
Examples of polyvalent carboxylic acids include aromatic carboxylic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, naphthalene dicarboxylic acid; maleic anhydride, fumaric acid, succinic acid, alkenyl Aliphatic carboxylic acids such as succinic anhydride and adipic acid; alicyclic carboxylic acids such as cyclohexanedicarboxylic acid, and the like. These polyvalent carboxylic acids may be used alone or in combination. Among these polyvalent carboxylic acids, it is desirable to use aromatic carboxylic acids, and in order to take a cross-linked structure or a branched structure in order to ensure good fixability, a tricarboxylic acid or higher carboxylic acid (trimellitic acid) together with a dicarboxylic acid. And acid anhydrides thereof) are preferably used in combination.

  Examples of the polyhydric alcohol in the amorphous polyester resin include aliphatic diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentylglycol, glycerin, etc .; cyclohexanediol, cyclohexane Examples thereof include alicyclic diols such as dimethanol and hydrogenated bisphenol A; aromatic diols such as an ethylene oxide adduct of bisphenol A and a propylene oxide adduct of bisphenol A. One or more of these polyhydric alcohols may be used. Among these polyhydric alcohols, aromatic diols and alicyclic diols are preferred, and among these, aromatic diols are more desirable. In order to secure better fixability, a trihydric or higher polyhydric alcohol (glycerin, trimethylolpropane, pentaerythritol) may be used in combination with the diol in order to form a crosslinked structure or a branched structure.

The glass transition temperature (Tg) of the amorphous polyester resin is desirably in the range of 50 ° C to 80 ° C. If Tg is lower than 50 ° C., problems may occur in terms of toner storage stability and fixed image storage stability. On the other hand, if the temperature is higher than 80 ° C., it may not be possible to fix at a lower temperature than conventional.
The Tg of the amorphous polyester resin is more preferably 50 ° C. or higher and 65 ° C. or lower.

  The ratio of the amorphous polyester resin and the crystalline polyester resin contained in the toner is not particularly limited, but the crystalline polyester resin is 1 part by mass or more and 30 parts by mass with respect to 100 parts by mass of the amorphous polyester resin. 2 parts by mass or more and 25 parts by mass or less are more preferable, and 3 parts by mass or more and 20 parts by mass or less are particularly preferable.

  In addition, you may perform manufacture of the said amorphous polyester resin according to the case of the said crystalline polyester resin.

In the present embodiment, other amorphous resins other than the amorphous polyester resin may be used in combination. Examples of other amorphous resins include known resin materials such as styrene / acrylic resins, epoxy resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and polyolefin resins.

-Colorant-
The colorant used in this embodiment may be a dye or a pigment, but a pigment is desirable from the viewpoint of light resistance and water resistance.
Desirable colorants include carbon black, aniline black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, rose bengal Quinacridone, benzicine yellow, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 185, C.I. I. Pigment red 238, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 74, C.I. I. Pigment blue 15: 1, C.I. I. A known pigment such as CI Pigment Blue 15: 3 is used.

  As content of the coloring agent in this embodiment, the range of 1 to 30 mass parts is desirable with respect to 100 mass parts of binder resin (total amount of crystalline polyester resin and non-crystalline polyester resin). It is also effective to use a surface-treated colorant or a pigment dispersant as necessary. By selecting the type of the colorant, yellow toner, magenta toner, cyan toner, black toner and the like can be obtained.

-Other additives-
In addition to the above components, various components such as an internal additive, a charge control agent, inorganic powder (inorganic particles), and organic particles may be further added to the toner of the exemplary embodiment as necessary.
Examples of the internal additive include metals such as ferrite, magnetite, reduced iron, cobalt, nickel, and manganese, alloys, and magnetic materials such as compounds containing these metals.

  The inorganic particles are added for various purposes, but may be added for adjusting the viscoelasticity of the toner. By adjusting the viscoelasticity, image glossiness and penetration into paper are adjusted. As the inorganic particles, known inorganic particles such as silica particles, titanium oxide particles, alumina particles, cerium oxide particles, or those obtained by hydrophobizing the surface thereof may be used alone or in combination of two or more. From the viewpoint of not impairing transparency such as color developability and OHP permeability, silica particles having a refractive index smaller than that of the binder resin are preferably used. Further, the silica particles may be subjected to various surface treatments, and for example, those subjected to surface treatment with a silane coupling agent, a titanium coupling agent, a silicone oil or the like are preferably used.

(Toner characteristics)
The volume average particle size of the toner according to the exemplary embodiment is preferably in the range of 4 μm to 9 μm, more preferably in the range of 4.5 μm to 8.5 μm, and still more preferably in the range of 5 μm to 8 μm. . When the volume average particle size is smaller than 4 μm, the toner fluidity is lowered, and the chargeability of each particle tends to be lowered. Further, since the charge distribution is widened, fogging on the background, toner spillage from the developing device, and the like are likely to occur. On the other hand, if the particle size is less than 4 μm, scattering of the low-charged toner during fixing may not be suppressed, and cleaning performance may be extremely difficult. When the volume average particle size is larger than 9 μm, the resolution may be lowered.
Here, the volume average particle diameter is measured using Coulter Multisizer II (manufactured by Coulter), and the electrolyte is measured using ISOTON-II (manufactured by Coulter).

Furthermore, it is preferable that the toner of the present exemplary embodiment has a spherical shape with a shape factor SF1 in the range of 110 to 140. When the shape is spherical in this range, transfer efficiency and image density are improved, and a high-quality image is formed.
The shape factor SF1 is more preferably in the range of 110 to 130.

Here, the shape factor SF1 is obtained by the following equation (1).
SF1 = (ML ² / A) × (π / 4) × 100 (1)
In the above formula (1), ML represents the absolute maximum length of the toner particles, and A represents the projected area of the toner particles.

  The SF1 is quantified mainly by analyzing a microscope image or a scanning electron microscope (SEM) image using an image analyzer, and is calculated as follows, for example. That is, an optical microscope image of particles scattered on the surface of the slide glass is taken into a Luzex image analyzer through a video camera, and the maximum length and projected area of 100 particles are obtained, calculated by the above equation (1), and the average value is calculated. It is obtained by seeking.

<Method for producing electrophotographic toner>
Examples of the method for producing an electrophotographic toner according to the present embodiment include a dry production method and a wet production method. In the case of a kneading pulverization method that is a dry production method, the crystallinity of the toner on the small particle diameter side in terms of the production method. This is not desirable because the resin content tends to increase. Examples of the wet production method include an emulsion aggregation method, a melt suspension method, and a dissolution suspension method.
Among these, in order to obtain a toner having a small particle size containing a crystalline resin, it is advantageous to use an emulsion aggregation method. The emulsion aggregation method may include a step of gradually aggregating various materials and further covering them. By passing through the coating step, the inclusion property of the crystalline resin is improved. When the crystalline resin is exposed on the toner surface, problems such as deterioration of fluidity occur. Therefore, production by the emulsion aggregation method is effective as a countermeasure.

  Hereinafter, as an example of a method for producing an electrophotographic toner according to this embodiment, a production method using an emulsion aggregation method will be described. In the emulsification aggregation method according to the present embodiment, a raw material constituting the toner is emulsified to form raw material particles (emulsified particles) such as resin particles, thereby forming an aggregate (aggregated particles) of the raw material particles (aggregated particles). A dispersion preparation step) and a fusion / unification step of fusing and coalescing the aggregates.

More specifically, in the method for producing an electrophotographic toner according to the present embodiment, the endothermic peak obtained by a differential scanning calorimeter (DSC) is in the range of 70 ° C. or higher and 95 ° C. or lower, and the endothermic peak is measured. A release agent dispersion in which a release agent having a half width of 10 ° C. to 18 ° C. is dispersed, a crystalline polyester resin dispersion in which a crystalline polyester resin is dispersed, and an amorphous in which an amorphous polyester resin is dispersed A dispersion of agglomerated particles containing the release agent, the crystalline polyester resin, the amorphous polyester resin, and the colorant by mixing a colorant dispersion in which the colorant polyester resin dispersion is dispersed. It is preferable to have an aggregated particle dispersion preparation step to be prepared and a fusion / union step of fusing and coalescing the aggregated particles by heating to an endothermic peak temperature of the release agent within a range of ± 10 ° C.
When the method for producing an electrophotographic toner according to the present embodiment is configured as described above, when the aggregated particles are fused and united, the high molecular weight component of the release agent that does not melt at the coalescing and uniting temperature is released. Aggregated particles fuse and coalesce through a semi-molten state coexisting with the low molecular weight component of the agent. Since it is in a semi-molten state, fusion between release agent particles and over-compatibility with a binder resin, particularly a crystalline polyester resin used as a low-temperature fixing component, is suppressed. As a result, the release agent is contained in the toner. It is presumed that it is uniformly dispersed.

(Emulsification method of each raw material)
In order to prepare a raw material dispersion used in the aggregated particle dispersion preparation step, an emulsified dispersion in which main materials constituting the toner are dispersed in an aqueous medium is prepared. Hereinafter, the resin dispersion, the colorant dispersion, the release agent dispersion, and the like will be described.

-Resin dispersion-
The volume average particle size of the resin particles dispersed in the resin dispersion may be from 0.01 μm to 1 μm, from 0.03 μm to 0.8 μm, and from 0.03 μm to 0.6 μm. There may be.
When the volume average particle size of the resin particles exceeds 1 μm, the particle size distribution of the finally obtained toner may be broadened, or free particles may be generated, which may easily reduce performance and reliability. On the other hand, if the volume average particle size is in the above range, the above-mentioned disadvantages are not obtained, the compositional uneven distribution among the toners is reduced, the dispersion in the toners is improved, and the variation in performance and reliability is advantageous. .

  In addition, the volume average particle diameter of the particles contained in the raw material dispersion such as resin particles is measured with a laser diffraction particle size distribution measuring apparatus (LA-700, manufactured by Horiba, Ltd.).

The dispersion medium used for the resin dispersion and other dispersions may be an aqueous medium.
Examples of the aqueous medium include water such as distilled water and ion exchange water, and alcohols. These may be used individually by 1 type and may use 2 or more types together. In the present invention, a surfactant may be added to and mixed with the aqueous medium.

  Although it does not specifically limit as surfactant, For example, anionic surfactants, such as sulfate ester type, sulfonate type, phosphate ester type, soap type; amine salt type, quaternary ammonium salt type, etc. Nonionic surfactants such as polyethylene glycol-based, alkylphenol ethylene oxide adduct-based, polyhydric alcohol-based, and the like. Among these, anionic surfactants and cationic surfactants are exemplified. The nonionic surfactant may be used in combination with the anionic surfactant or the cationic surfactant. The said surfactant may be used individually by 1 type, and may use 2 or more types together.

  Specific examples of the anionic surfactant include sodium dodecylbenzenesulfonate, sodium dodecylsulfate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate and the like. Specific examples of the cationic surfactant include alkylbenzene dimethyl ammonium chloride, alkyl trimethyl ammonium chloride, distearyl ammonium chloride and the like. Among these, ionic surfactants such as anionic surfactants and cationic surfactants can be mentioned.

  When the resin particle is a polyester resin, it has a self-water dispersibility because it contains a functional group that can be anionic by neutralization, and part or all of the functional group that can be hydrophilic is neutralized with a base. To form a stable aqueous dispersion under the action of an aqueous medium.

  Since functional groups that can become hydrophilic groups by neutralization in polyester resins are acidic groups such as carboxyl groups and sulfonic acid groups, examples of neutralizing agents include sodium hydroxide, potassium hydroxide, lithium hydroxide, and hydroxide. Examples include inorganic bases such as calcium, sodium carbonate, and ammonia, and organic bases such as diethylamine, triethylamine, and isopropylamine.

  When adjusting a resin dispersion using a polyester resin, a phase inversion emulsification method may be used. The phase inversion emulsification method may also be used when adjusting the resin dispersion using a binder resin other than the polyester resin. In the phase inversion emulsification method, a resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, a base is added to the organic continuous phase (O phase), and the aqueous medium (W Phase), the resin is converted from W / O to O / W (so-called phase inversion) to form a discontinuous phase, and the resin is dispersed and stabilized in the form of particles in an aqueous medium. It is.

  Examples of the organic solvent used for this phase inversion emulsification include ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, and tert. -Alcohols such as amyl alcohol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, cyclohexanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, cyclohexanone, isophorone, tetrahydrofuran , Ethers such as dimethyl ether, diethyl ether, dioxane, methyl acetate, ethyl acetate, acetic acid-n-propyl, isopropyl acetate, acetic acid-n-butyl, isobutyl acetate, vinegar -Sec-butyl, acetate-3-methoxybutyl, methyl propionate, ethyl propionate, butyl propionate, dimethyl oxalate, diethyl oxalate, dimethyl succinate, diethyl succinate, diethyl carbonate, dimethyl carbonate, Ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol ethyl ether acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether , Diethylene glycol ethyl ether acetate Glycol derivatives such as propylene glycol, propylene glycol monomethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol methyl ether acetate, dipropylene glycol monobutyl ether, 3-methoxy-3-methylbutanol, 3-methoxy Examples include butanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, ethyl acetoacetate and the like. These solvents may be used alone or in combination of two or more.

  The amount of the organic solvent used for phase inversion emulsification is difficult to determine in general because the amount of solvent for obtaining a desired dispersed particle size varies depending on the physical properties of the resin. When the amount of the solvent is small, the emulsifiability becomes insufficient, and the particle size of the resin particles may be increased or the particle size distribution may be broadened.

  When the binder resin is dispersed in water, some or all of the carboxyl groups in the resin may be neutralized with a neutralizing agent as necessary. Examples of the neutralizing agent include inorganic alkalis such as potassium hydroxide and sodium hydroxide, ammonia, monomethylamine, dimethylamine, triethylamine, monoethylamine, diethylamine, triethylamine, mono-npropylamine, dimethyl n-propylamine, monoethanol. Amines such as amine, diethanolamine, triethanolamine, N-methylethanolamine, N-aminoethylethanolamine, N-methyldiethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, N, N-dimethylpropanolamine, etc. 1 type or 2 types or more selected from these may be used. By adding these neutralizing agents, the pH during emulsification is adjusted to neutral, and hydrolysis of the resulting polyester resin dispersion is prevented.

  Further, a dispersant may be added during the phase inversion emulsification for the purpose of stabilizing the dispersed particles and preventing thickening of the aqueous medium. Examples of the dispersant include water-soluble polymers such as polyvinyl alcohol, methylcellulose, ethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, sodium polyacrylate, and sodium polymethacrylate, sodium dodecylbenzenesulfonate, sodium octadecylsulfate, and oleic acid. Anionic surfactants such as sodium, sodium laurate, potassium stearate, cationic surfactants such as laurylamine acetate, stearylamine acetate, lauryltrimethylammonium chloride, zwitterionic surfactants such as lauryldimethylamine oxide, polyoxy Nonio such as ethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine Surfactants such as sex surfactant, tricalcium phosphate, aluminum hydroxide, calcium sulfate, calcium carbonate, and inorganic compounds such as barium carbonate. These dispersants may be used alone or in combination of two or more. The dispersant may be added in an amount of 0.01 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the binder resin.

  The emulsification temperature at the time of phase inversion emulsification may be not higher than the boiling point of the organic solvent and not lower than the melting temperature or glass transition temperature of the binder resin. When the emulsification temperature is lower than the melting temperature or glass transition temperature of the binder resin, it is difficult to adjust the resin dispersion. In addition, when emulsifying above the boiling point of the organic solvent, the emulsification may be performed with a pressure-sealed device.

  The content of the resin particles contained in the resin dispersion may be usually 5% by mass or more and 50% by mass or less, or 10% by mass or more and 40% by mass or less. When the content is out of the above range, the particle size distribution of the resin particles is widened, and the characteristics may be deteriorated.

  In addition, the resin dispersion may be produced by applying a shearing force to a solution obtained by mixing an aqueous medium and a resin with a disperser. At that time, particles may be formed by heating to lower the viscosity of the resin component. A dispersant may be used for stabilizing the dispersed resin particles.

Examples of the aqueous medium include water such as distilled water and ion-exchanged water; alcohols; and the like.
Examples of the dispersant include water-soluble polymers such as polyvinyl alcohol, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, sodium polyacrylate, and sodium polymethacrylate; sodium dodecylbenzenesulfonate, sodium octadecylsulfate, and oleic acid. Anionic surfactants such as sodium, sodium laurate, potassium stearate, cationic surfactants such as laurylamine acetate, stearylamine acetate, lauryltrimethylammonium chloride, zwitterionic surfactants such as lauryldimethylamine oxide, Such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkylamine, etc. Surfactants such as anion surfactants; and the like are; tricalcium phosphate, aluminum hydroxide, calcium sulfate, calcium carbonate, inorganic salts such as barium carbonate.

  Examples of the disperser used for preparing the resin dispersion include a homogenizer, a homomixer, a pressure kneader, an extruder, and a media disperser. As the size of the resin particles, the average particle size (volume average particle size) is preferably 1.0 μm or less, more preferably in the range of 60 nm to 300 nm, and still more preferably in the range of 150 nm to 250 nm. . If it is less than 60 nm, the resin particles become stable particles in the dispersion, and thus aggregation of the resin particles may be difficult. On the other hand, if it exceeds 1.0 μm, the cohesiveness of the resin particles is improved and it becomes easy to prepare toner particles, but the particle size distribution of the toner may be widened.

-Colorant dispersion-
As a dispersion method at the time of adjusting the colorant dispersion, for example, a general dispersion method such as a rotary shear type homogenizer, a ball mill having a medium, a sand mill, or a dyno mill may be used. . If necessary, an aqueous dispersion of a colorant may be prepared using a surfactant, or an organic solvent dispersion of a colorant may be prepared using a dispersant. As the surfactant and the dispersant used for the dispersion, the same dispersants that can be used when the resin is dispersed may be used.

  In preparing the raw material dispersion, the colorant dispersion may be mixed at the same time with the dispersion in which other particles are dispersed, or may be divided and added and mixed in multiple stages.

  The content of the colorant contained in the colorant dispersion may be usually 5% by mass or more and 50% by mass or less, or 10% by mass or more and 40% by mass or less. When the content is out of the above range, the particle size distribution of the colorant particles is widened, and the characteristics may be deteriorated.

-Release agent dispersion-
The release agent dispersion is a solution in which the release agent is dispersed in water together with an ionic surfactant, heated to a temperature higher than the melting temperature of the release agent, and a strong shearing force is applied using a homogenizer or a pressure discharge type dispersion machine. It is prepared by. Thereby, the release agent particles having a volume average particle diameter of 1 μm or less are dispersed. In order to uniformly disperse in the toner, it is desirable that the volume average particle size is about 150 nm to 400 nm. Further, as the dispersion medium in the release agent dispersion, the same dispersion medium as that used for the binder resin may be used.

  In addition, as an apparatus for mixing and dispersing the resin, colorant and the like with a dispersion medium, for example, a homomixer (Special Machine Industries Co., Ltd.), a slasher (Mitsui Mine Co., Ltd.), Cavitron (Eurotech Co., Ltd.) ), Microfluidizer (Mizuho Kogyo Co., Ltd.), Menton Gorin homogenizer (Gorin Inc.), Nanomizer (Nanomizer Inc.), static mixer (Noritake Company), etc.

  Depending on the purpose, components such as a release agent, an internal additive, a charge control agent, and an inorganic powder may be dispersed in the resin dispersion.

  When preparing a dispersion of other components (additives) other than the binder resin, the colorant, and the release agent, the volume average particle size of the particles dispersed in the dispersion is usually 1 μm or less. It may be 0.01 μm or more and 0.5 μm or less. If the volume average particle size exceeds 1 μm, the particle size distribution of the finally obtained toner may be broadened, or free particles may be generated, which may lead to a decrease in performance and reliability. On the other hand, when the volume average particle size is in the above range, there are no disadvantages, and the uneven distribution among the toners is reduced, the dispersion in the toner is good, and the variation in performance and reliability is reduced.

(Aggregated particle dispersion preparation process)
In the agglomerated particle dispersion preparation step, first, the obtained resin dispersion (crystalline polyester resin dispersion, amorphous polyester resin dispersion), colorant dispersion, release agent dispersion, etc. are mixed to obtain a mixed solution And agglomerated by heating at a temperature not higher than the glass transition temperature of the amorphous polyester resin to form aggregated particles. Aggregated particles are formed by acidifying the pH of the mixed solution with stirring. As pH, the range of 2-7 is desirable, The range of 2.2-6 is more desirable, The range of 2.4-5 is further more desirable. At this time, it is also effective to use a flocculant.

  As the aggregating agent, a surfactant having a polarity opposite to that of the surfactant used for the dispersant, an inorganic metal salt, and a divalent or higher-valent metal complex are preferably used. In particular, the use of a metal complex is particularly desirable because the amount of the surfactant used can be reduced and the charging characteristics are improved.

Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, aluminum sulfate, and polyaluminum chloride, polyaluminum hydroxide, calcium polysulfide, and the like. Examples thereof include inorganic metal salt polymers. Of these, aluminum salts and polymers thereof are particularly preferred. In order to obtain a sharper particle size distribution, the valence of the inorganic metal salt is bivalent than monovalent, trivalent than bivalent, trivalent than trivalent, and tetravalent than trivalent. The inorganic metal salt polymer is more suitable.
In the present embodiment, it is preferable to use a tetravalent inorganic metal salt polymer containing aluminum from the viewpoint of obtaining a narrow particle size distribution.

  Further, a toner having a configuration in which the surface of the core aggregated particles is coated with the amorphous polyester resin may be prepared by additionally adding amorphous polyester resin particles when the aggregated particles have a desired particle size. . In this case, the crystalline polyester resin is difficult to be exposed on the toner surface, which is desirable from the viewpoint of chargeability and developability. In the case of additional addition, a flocculant may be added or pH adjustment may be performed before additional addition.

(Fusion / unification process)
In the coalescence and coalescence process, the agglomeration is stopped and separated by raising the pH of the aggregated particle suspension to a range of 3 to 9 under stirring conditions in accordance with the aggregated particle dispersion preparation process. The aggregated particles are fused and coalesced by heating to the endothermic peak temperature of the mold agent within a range of ± 10 ° C. Moreover, when it coat | covers with an amorphous polyester resin, this amorphous polyester resin is also united and a core aggregated particle is coat | covered. The heating time may be performed to the extent that fusion is performed, and may be performed for about 0.5 hour to 10 hours.

Cool after fusion to obtain fused particles. Further, in the cooling step, crystallization may be promoted by so-called gradual cooling in which the cooling rate is reduced in the vicinity of the melting temperature of the crystalline resin (melting temperature ± 10 ° C.).
The fused particles obtained by fusing are made into toner particles through a solid-liquid separation process such as filtration and, if necessary, a washing process and a drying process.

  In the present embodiment, an external additive such as a fluidizing agent or an auxiliary agent may be added to the surface of the toner particles. Examples of the external additive include known inorganic particles such as silica particles, titanium oxide particles, alumina particles, cerium oxide particles, and carbon black whose surfaces have been hydrophobized, and polymer particles such as polycarbonate, polymethyl methacrylate, and silicone resin. Particles are used.

-Electrophotographic developer-
The electrophotographic developer according to the exemplary embodiment (hereinafter sometimes simply referred to as “developer”) is not particularly limited as long as it includes the toner of the exemplary embodiment, and is a one-component developer or a two-component developer. Any of the agents may be used. When used as a two-component developer, a toner and a carrier are mixed and used.
The carrier that can be used in the two-component developer is not particularly limited, and a known carrier is used. Examples thereof include magnetic metals such as iron oxide, nickel and cobalt, magnetic oxides such as ferrite and magnetite, resin-coated carriers having a resin coating layer on the surface of the core material, and magnetic dispersion carriers. Further, a resin-dispersed carrier in which a conductive material or the like is dispersed in a matrix resin may be used.

  Coating resins and matrix resins used for carriers 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, but are not limited to, acid copolymers, straight silicone resins composed of organosiloxane bonds or modified products thereof, fluororesins, polyesters, polycarbonates, phenol resins, epoxy resins, and the like.

  Examples of the conductive material include metals such as gold, silver and copper, carbon black, titanium oxide, zinc oxide, barium sulfate, aluminum borate, potassium titanate, tin oxide, and carbon black, but are not limited thereto. It is not something.

Examples of the core material of the carrier include magnetic metals such as iron, nickel, and cobalt, magnetic oxides such as ferrite and magnetite, and glass beads. However, in order to use the carrier for the magnetic brush method, it is a magnetic material. May be.
The volume average particle size of the core material of the carrier is generally 10 μm or more and 500 μm or less, and may be 30 μm or more and 100 μm or less.

  In order to coat the surface of the core material of the carrier with a resin, there may be mentioned a method of coating with a coating layer forming solution in which the coating resin and, if necessary, various additives are dissolved in an appropriate solvent. The solvent is not particularly limited, and may be selected in consideration of the coating resin to be used, coating suitability, and the like.

  Specific resin coating methods include an immersion method in which the carrier core material is immersed in the coating layer forming solution, a spray method in which the coating layer forming solution is sprayed onto the surface of the carrier core material, and the carrier core material is fluidized air. And a kneader coater method in which the carrier core material and the coating layer forming solution are mixed in a kneader coater and the solvent is removed in a kneader coater.

  The mixing ratio (weight ratio) of the toner and the carrier in the two-component developer may be in the range of toner: carrier = 1: 100 to 30: 100, or in the range of 3: 100 to 20: 100. It may be.

<Image forming apparatus>
Next, an image forming apparatus according to this embodiment using the toner of this embodiment will be described.
The image forming apparatus according to the present embodiment includes a photosensitive member, a charging unit that charges the photosensitive member, an electrostatic charge image forming unit that forms an electrostatic charge image on the surface of the charged photosensitive member, and a photosensitive member on the photosensitive member. A developing unit that develops the formed electrostatic image as a toner image by the electrophotographic developer according to the present embodiment, a transfer unit that transfers the toner image onto a transfer target, and a fixing that fixes the toner image. Means.

In this image forming apparatus, for example, the part including the developing unit may have a cartridge structure (process cartridge) that can be attached to and detached from the image forming apparatus main body. As the process cartridge, a developer holding body is used. The process cartridge according to the present embodiment, which is provided at least and contains the electrophotographic developer according to the present embodiment, is preferably used.
Hereinafter, an example of the image forming apparatus according to the present embodiment will be described, but the present invention is not limited thereto. The main parts shown in the figure will be described, and the description of the other parts will be omitted.

  FIG. 1 is a schematic configuration diagram showing a four-tandem color image forming apparatus. The image forming apparatus shown in FIG. 1 is a first to first electrophotographic method that outputs yellow (Y), magenta (M), cyan (C), and black (K) images based on color-separated image data. Fourth image forming units 10Y, 10M, 10C, and 10K (image forming means) are provided. These image forming units (hereinafter sometimes simply referred to as “units”) 10Y, 10M, 10C, and 10K are arranged in parallel at a predetermined distance from each other in the horizontal direction. The units 10Y, 10M, 10C, and 10K may be process cartridges that are detachable from the main body of the image forming apparatus.

Above each of the units 10Y, 10M, 10C, and 10K, an intermediate transfer belt 20 as an intermediate transfer member is extended through each unit. The intermediate transfer belt 20 is provided by being wound around a driving roller 22 and a support roller 24 that are in contact with the inner surface of the intermediate transfer belt 20 that are spaced apart from each other from the left to the right in the drawing. The vehicle travels in the direction toward the unit 10K. A force is applied to the support roller 24 in a direction away from the drive roller 22 by a spring or the like (not shown), and tension is applied to the intermediate transfer belt 20 wound around the both. Further, an intermediate transfer member cleaning device 30 is provided on the side of the image carrier of the intermediate transfer belt 20 so as to face the driving roller 22.
Further, each of the developing devices (developing means) 4Y, 4M, 4C, and 4K of the units 10Y, 10M, 10C, and 10K has yellow, magenta, cyan, and black contained in the toner cartridges 8Y, 8M, 8C, and 8K. The four colors of toner are supplied.

  Since the first to fourth units 10Y, 10M, 10C, and 10K described above have the same configuration, here, the first image that forms the yellow image disposed on the upstream side in the intermediate transfer belt traveling direction is formed. The unit 10Y will be described as a representative. Note that the second to fourth components are denoted by reference numerals with magenta (M), cyan (C), and black (K) instead of yellow (Y) in the same parts as the first unit 10Y. Description of the units 10M, 10C, and 10K will be omitted.

The first unit 10Y includes a photoreceptor 1Y that functions as an image holding member. Around the photosensitive member 1Y, a charging roller 2Y for charging the surface of the photosensitive member 1Y to a predetermined potential, and the charged surface is exposed by a laser beam 3Y based on the color-separated image signal to form an electrostatic charge image. An exposure device (electrostatic image forming means) 3 for forming, a developing device (developing means) 4Y for supplying the charged toner to the electrostatic image and developing the electrostatic image, and transferring the developed toner image onto the intermediate transfer belt 20 A primary transfer roller 5Y (primary transfer unit) that performs the transfer and a photoconductor cleaning device (cleaning unit) 6Y that removes toner remaining on the surface of the photoconductor 1Y after the primary transfer are sequentially arranged.
The primary transfer roller 5Y is disposed inside the intermediate transfer belt 20, and is provided at a position facing the photoreceptor 1Y. Further, a bias power source (not shown) for applying a primary transfer bias is connected to each of the primary transfer rollers 5Y, 5M, 5C, and 5K. Each bias power source varies the transfer bias applied to each primary transfer roller under the control of a control unit (not shown).

Hereinafter, an operation of forming a yellow image in the first unit 10Y will be described. First, prior to the operation, the surface of the photoreceptor 1Y is charged to a potential of about −600V to −800V by the charging roller 2Y.
The photoreceptor 1Y is formed by laminating a photosensitive layer on a conductive substrate (volume resistivity at 20 ° C .: 1 × 10 ⁻⁶ Ωcm or less). This photosensitive layer usually has a high resistance (a resistance equivalent to that of a general resin), but has a property that the specific resistance of the portion irradiated with the laser beam changes when irradiated with the laser beam 3Y. Therefore, a laser beam 3Y is output to the surface of the charged photoreceptor 1Y via the exposure device 3 in accordance with yellow image data sent from a control unit (not shown). The laser beam 3Y is applied to the photosensitive layer on the surface of the photoreceptor 1Y, whereby an electrostatic charge image of a yellow print pattern is formed on the surface of the photoreceptor 1Y.

The electrostatic charge image is an image formed on the surface of the photoreceptor 1Y by charging, and the specific resistance of the irradiated portion of the photosensitive layer is lowered by the laser beam 3Y, and the charged charge on the surface of the photoreceptor 1Y flows. On the other hand, this is a so-called negative latent image formed by the charge remaining in the portion not irradiated with the laser beam 3Y.
The electrostatic charge image formed on the photoreceptor 1Y in this way is rotated to a predetermined development position as the photoreceptor 1Y travels. At this development position, the electrostatic charge image on the photoreceptor 1Y is visualized (developed image) by the developing device 4Y.

In the developing device 4Y, for example, an electrophotographic developer containing at least yellow toner and a carrier is accommodated. The yellow toner is triboelectrically charged by being agitated inside the developing device 4Y, and has a charge of the same polarity (negative polarity) as the charged charge on the photoreceptor 1Y, and a developer roll (developer holder). Is held on. As the surface of the photoreceptor 1Y passes through the developing device 4Y, the yellow toner is electrostatically attached to the latent image portion on the surface of the photoreceptor 1Y, and the latent image is developed with the yellow toner. .
From the viewpoint of development efficiency, image granularity, gradation reproducibility, and the like, a bias potential (development bias) in which an AC component is superimposed on a DC component may be applied to the developer holder. Specifically, when the developer holder DC applied voltage Vdc is −300 to −700 V, the developer holder AC voltage peak width Vp-p may be in the range of 0.5 to 2.0 kV.
The photoreceptor 1Y on which the yellow toner image is formed continues to run at a predetermined speed, and the toner image developed on the photoreceptor 1Y is conveyed to a predetermined primary transfer position.

When the yellow toner image on the photoreceptor 1Y is conveyed to the primary transfer position, a primary transfer bias is applied to the primary transfer roller 5Y, and electrostatic force directed from the photoreceptor 1Y to the primary transfer roller 5Y is applied to the toner image. As a result, the toner image on the photoreceptor 1 </ b> Y is transferred onto the intermediate transfer belt 20. The transfer bias applied at this time is a (+) polarity opposite to the polarity (−) of the toner, and is controlled to about +10 μA by the control unit (not shown) in the first unit 10Y, for example.
On the other hand, the toner remaining on the photoreceptor 1Y is removed and collected by the cleaning device 6Y.

Further, the primary transfer bias applied to the primary transfer rollers 5M, 5C, and 5K after the second unit 10M is also controlled according to the first unit.
Thus, the intermediate transfer belt 20 onto which the yellow toner image has been transferred by the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, and 10K, and the toner images of the respective colors are superimposed and transferred in a multiple manner. The

  The intermediate transfer belt 20 onto which the four color toner images have been transferred through the first to fourth units is arranged on the image transfer surface side of the intermediate transfer belt 20, the support roller 24 in contact with the inner surface of the intermediate transfer belt 20. The secondary transfer roller (secondary transfer means) 26 is connected to a secondary transfer portion. On the other hand, the recording paper (transfer object) P is fed at a predetermined timing to the gap where the secondary transfer roller 26 and the intermediate transfer belt 20 are pressed against each other via the supply mechanism, and the secondary transfer bias is supported. Applied to the roller 24. The transfer bias applied at this time is a (−) polarity that is the same polarity as the polarity (−) of the toner, and an electrostatic force from the intermediate transfer belt 20 toward the recording paper P is applied to the toner image, and the transfer bias is applied to the intermediate transfer belt 20. The toner image is transferred onto the recording paper P. Note that the secondary transfer bias at this time is determined according to the resistance detected by a resistance detecting means (not shown) for detecting the resistance of the secondary transfer portion, and is voltage-controlled.

  Thereafter, the recording paper P is fed to the pressure contact portion (nip portion) of the pair of fixing rolls in the fixing device (roll-type fixing means) 28, the toner image is heated, and the color-superposed toner image is melted to record the recording paper. Fixed onto P.

  Examples of the transfer target to which the toner image is transferred include plain paper and OHP sheet used for electrophotographic copying machines, printers, and the like.

The recording paper P on which the color image has been fixed is carried out toward the discharge unit, and a series of color image forming operations is completed.
The image forming apparatus exemplified above is configured to transfer the toner image onto the recording paper P via the intermediate transfer belt 20, but the present invention is not limited to this configuration, and the toner image is directly transferred from the photoconductor. It may be a structure that is transferred to a recording sheet.

<Process cartridge, toner cartridge>
FIG. 2 is a schematic configuration diagram showing a preferred example embodiment of a process cartridge containing an electrophotographic developer according to this embodiment. The process cartridge 200 combines the developing device 111 with the photosensitive member 107, the charging roller 108, the photosensitive member cleaning device 113, the opening 118 for exposure, and the opening 117 for static elimination exposure using the mounting rail 116. , And integrated. In FIG. 2, reference numeral 300 denotes a transfer target.
The process cartridge 200 is detachable from an image forming apparatus main body including a transfer device 112, a fixing device 115, and other components (not shown). It forms a forming apparatus.

  The process cartridge 200 shown in FIG. 2 includes a photosensitive member 107, a charging device 108, a developing device 111, a cleaning device 113, an opening 118 for exposure, and an opening 117 for static elimination exposure. The devices may be selectively combined. In the process cartridge of this embodiment, in addition to the developing device 111, the photosensitive member 107, the charging device 108, the cleaning device (cleaning means) 113, the opening 118 for exposure, and the opening 117 for static elimination exposure. You may provide at least 1 sort (s) selected from the group comprised from these.

  Next, the toner cartridge according to this embodiment will be described. The toner cartridge according to the exemplary embodiment is detachably mounted on the image forming apparatus, and at least the toner cartridge that stores toner to be supplied to the developing unit provided in the image forming apparatus. The toner for electrophotography according to the present embodiment is obtained. Note that the toner cartridge according to the present embodiment only needs to contain at least toner, and may contain developer, for example, depending on the mechanism of the image forming apparatus.

  Therefore, in the image forming apparatus having a configuration in which the toner cartridge can be attached and detached, the toner for electrophotography according to this embodiment can be easily obtained by using the toner cartridge containing the toner for electrophotography according to this embodiment. Supplied to the developing device.

  The image forming apparatus shown in FIG. 1 is an image forming apparatus having a configuration in which the toner cartridges 8Y, 8M, 8C, and 8K can be attached and detached, and the developing devices 4Y, 4M, 4C, and 4K are respectively the developing devices ( And a toner supply pipe (not shown). Further, when the toner stored in the toner cartridge becomes low, the toner cartridge is replaced.

  Hereinafter, although an Example and a comparative example are given and this embodiment is described in detail in detail, this embodiment is not limited to the following examples. Unless otherwise specified, “part” and “%” are based on mass.

-Synthesis of crystalline polyester resin-
In a heat-dried three-necked flask, 230 parts of 1,10-dodecanedioic acid, 160 parts of 1,9-nonanediol, and 0.2 part of dibutyltin oxide as a catalyst were added, and then the air in the three-necked flask was removed by depressurization. The reaction was allowed to proceed under an inert atmosphere by replacing with nitrogen at 180 ° C. for 5 hours by mechanical stirring and refluxing. During the reaction, water produced in the reaction system was distilled off. Thereafter, the temperature was gradually raised to 235 ° C. under reduced pressure, and after stirring for 2 hours, the molecular weight was confirmed by GPC. When the weight average molecular weight reached 28500, the distillation under reduced pressure was stopped and the crystals were crystallized. A functional polyester resin was obtained. The crystalline polyester resin had a melting temperature of 73 ° C., a softening temperature of 75 ° C., and an acid value of 12.5 mgKOH / g.

-Preparation of crystalline polyester resin dispersion-
100 parts of this crystalline polyester resin, 35 parts of ethyl acetate, and 35 parts of isopropyl alcohol were placed in a separable flask and thoroughly mixed and dissolved at 75 ° C. Then, 5.5 parts of a 10% aqueous ammonia solution was added dropwise. The heating temperature is lowered to 60 ° C., and ion-exchanged water is added dropwise with stirring using a liquid feed pump at a liquid feed speed of 6 g / min. After the liquid becomes cloudy, the liquid feed speed is increased to 25 g / min. When the amount reached 400 parts, dropping of ion-exchanged water was stopped. Thereafter, the solvent was removed under reduced pressure to obtain a crystalline polyester resin dispersion. The obtained crystalline polyester resin particles had a volume average particle diameter of 138 nm and the polyester resin particles had a solid content concentration of 26.21%.

-Synthesis of Amorphous Polyester Resin 1-
・ Bisphenol A propylene oxide 2-mole adduct 310 parts ・ 116 parts of terephthalic acid ・ 12 parts of fumaric acid ・ 54 parts of dodecenyl succinic acid ・ 0.05 parts of Ti (OBu) ₄

  After the above raw materials were put into a heat-dried three-necked flask, the air in the container was depressurized by a depressurization operation, and was further brought into an inert atmosphere with nitrogen gas, and refluxed at 180 ° C. for 8 hours with mechanical stirring. Thereafter, the temperature was gradually raised to 230 ° C. while distilling off the water produced in the reaction system by vacuum distillation. Further, the dehydration condensation reaction was continued at 240 ° C. for 3 hours. When the mixture became viscous, the molecular weight was confirmed by GPC. When the weight average molecular weight reached 23000, the vacuum distillation was stopped and the amorphous polyester resin 1 was obtained. Obtained. Amorphous polyester resin 1 was amorphous and had a glass transition temperature of 60 ° C., a softening temperature of 115 ° C., and an acid value of 13 mgKOH / g. The “Bu” represents “butyl”.

-Preparation of Amorphous Polyester Resin Dispersion 1-
Next, 100 parts of this amorphous polyester resin 1, 50 parts of ethyl acetate, 25 parts of isopropyl alcohol, and 5 parts of 10% aqueous ammonia solution were placed in a separable flask and mixed and dissolved sufficiently. While heating and stirring at 40 ° C., ion-exchanged water was added dropwise at a liquid feed rate of 8 g / min using a liquid feed pump. After the liquid became cloudy, the liquid feeding speed was increased to 25 g / min to cause phase inversion, and dropping was stopped when the liquid feeding amount reached 135 parts. Thereafter, the solvent was removed under reduced pressure to obtain an amorphous polyester resin dispersion 1. The obtained polyester resin particles had a volume average particle size of 132 nm and the polyester resin particles had a solid content concentration of 32.0%.

-Synthesis of Amorphous Polyester Resin 2-
・ Bisphenol A propylene oxide 2 mol adduct 310 parts ・ Terephthalic acid 100 parts ・ Adipic acid 9 parts ・ Fumaric acid 12 parts ・ Dodecenyl succinic acid 54 parts ・ Ti (OBu) ₄ 0.05 parts

  After the above raw materials were put into a heat-dried three-necked flask, the air in the container was depressurized by a depressurization operation, and was further brought into an inert atmosphere with nitrogen gas and refluxed at 180 ° C. for 8 hours with mechanical stirring. Thereafter, the temperature was gradually raised to 230 ° C. while distilling off the water produced in the reaction system by vacuum distillation. Further, the dehydration condensation reaction was continued at 240 ° C. for 3 hours. When the mixture became viscous, the molecular weight was confirmed by GPC. When the weight average molecular weight reached 23000, the vacuum distillation was stopped and the amorphous polyester resin 2 was obtained. Obtained. Amorphous polyester resin 2 was amorphous and had a glass transition temperature of 55 ° C, a softening temperature of 115 ° C, and an acid value of 13 mgKOH / g. The “Bu” represents “butyl”.

-Preparation of amorphous polyester resin dispersion 2-
Next, 100 parts of this amorphous polyester resin 2, 50 parts of ethyl acetate, 25 parts of isopropyl alcohol, and 5 parts of 10% aqueous ammonia solution were placed in a separable flask and mixed and dissolved sufficiently. While heating and stirring at 40 ° C., ion-exchanged water was added dropwise at a liquid feed rate of 8 g / min using a liquid feed pump. After the liquid became cloudy, the liquid feeding speed was increased to 25 g / min to cause phase inversion, and dropping was stopped when the liquid feeding amount reached 135 parts. Thereafter, the solvent was removed under reduced pressure to obtain an amorphous polyester resin dispersion 2. The obtained polyester resin particles had a volume average particle size of 130 nm, and the polyester resin particles had a solid content concentration of 31.5%.

-Preparation of colorant dispersion-
(Preparation of colorant dispersion 1 (black))
・ Carbon black (Degussa, NIPex35) 120 parts ・ Anionic surfactant 8.64 parts ・ Ion-exchanged water 485 parts The above were mixed and dissolved, and the high-pressure impact disperser Ultimateizer (manufactured by Sugino Machine Co., Ltd.) HJP30006) was used for 1 hour to prepare a colorant dispersion 1 in which carbon black was dispersed. The volume average particle diameter of the colorant particles in the colorant dispersion 1 was 0.13 μm, and the colorant particle concentration was 20.98%.

(Preparation of colorant dispersion 2 (Cyan))
・ C. I. Pigment Blue 15: 3 13.75 parts, anionic surfactant 1.238 parts, ion-exchanged water 41.697 parts The above are mixed and dissolved, and a high-pressure impact disperser Ultimateizer (manufactured by Sugino Machine Co., Ltd., HJP30006) For 1 hour to prepare a colorant dispersion 2 in which a cyan colorant was dispersed. The volume average particle diameter of the colorant particles in the colorant dispersion 2 was 0.18 μm, and the colorant particle concentration was 26.44%.

-Preparation of release agent 1 and dispersion thereof-
Sasol FT wax H1 and C80 melt blended 50 parts at a time, and evaporating surface temperature from 240 ° C. to 300 ° C., vacuum degree 0.7 Pa in a centrifugal molecular distillation apparatus (MS-380) manufactured by Nippon Vehicle Co., Ltd. The low-molecular component was removed first and then separated from the high-molecular-weight component to obtain a main fraction. The obtained release agent 1 had DSC characteristics with an endothermic peak of DSC of 85 ° C. and a half-value width of 13 ° C.
The ratio of normal hydrocarbon in the release agent 1 was 95%.

-Preparation of release agent dispersion 1-
-Mold release agent 1 180 parts-Anionic surfactant 4.5 parts-Ion-exchanged water 410 parts The above was heated to 110 ° C and dispersed using a homogenizer (manufactured by IKA: Ultra Turrax T50). Disperse with a Manton Gorin high-pressure homogenizer (Gorin Co., Ltd.) to disperse release agent particles having a volume average particle size of 0.24 μm, adjust the concentration with ion-exchanged water, and release agent concentration is 31.0%. A release agent dispersion 1 was prepared.

-Preparation of mold release agent 2 and dispersion thereof-
A material obtained by melt-blending 50 parts of Paraffin HNP9 manufactured by Nippon Seiwa Co., Ltd. and FT wax C80 manufactured by Sasol Co., respectively, was used as a raw material. Distillation was carried out under the conditions of 0 ° C. and a vacuum degree of 0.7 Pa to remove low molecular components first, and then separated from high molecular weight components to obtain a main fraction. The obtained release agent 2 had DSC characteristics with an endothermic peak of DSC of 75 ° C. and a half-value width of 15 ° C.
The ratio of normal hydrocarbons in release agent 2 was 94%.
-Preparation of release agent dispersion 2-
In the same manner as the release agent dispersion 1, a release agent dispersion 2 having a volume average particle size of 0.21 μm and a release agent concentration of 31.0% was prepared.

-Preparation of release agent 3 and dispersion thereof-
A 50-part melt blended FT wax 100 and 105 manufactured by Shell was used as a raw material, and an evaporation surface temperature of 240 ° C. to 300 ° C. and a degree of vacuum of 0.degree. Distillation was performed under conditions of 7 Pa to remove low molecular components first, and then separate from high molecular weight components to obtain a main fraction. The obtained release agent 3 had a DSC characteristic with an endothermic peak of DSC of 90 ° C. and a half width of 13 ° C.
The ratio of normal hydrocarbons in the release agent 3 was 95%.
-Preparation of release agent dispersion 3-
In the same manner as the release agent dispersion 1, a release agent dispersion 3 having a volume average particle size of 0.24 μm and a release agent concentration of 31.0% was prepared.

-Preparation of release agent 4 and dispersion thereof-
Using FT wax C80 manufactured by Sasol as a raw material, distillation was performed with a centrifugal molecular distillation device (MS-380) manufactured by Nippon Vehicle Co., Ltd. under conditions of an evaporation surface temperature of 260 ° C. and a vacuum degree of 0.7 Pa to remove low molecular components. A fraction was obtained. The obtained release agent 4 had DSC characteristics with an endothermic peak of DSC of 85 ° C. and a half-value width of 9 ° C.
The ratio of normal hydrocarbons in the release agent 4 was 94%.
-Preparation of release agent dispersion 4-
In the same manner as the release agent dispersion 1, a release agent dispersion 4 having a volume average particle size of 0.20 μm and a release agent concentration of 31.0% was prepared.

-Preparation of release agent 5 and dispersion thereof-
A material obtained by melt blending 50 parts of Sasol FT wax C80 and Shell FT wax 105 each with a centrifugal molecular distillation apparatus (MS-380) manufactured by Nippon Vehicle Co., Ltd. has an evaporation surface temperature of 240 ° C. to 300 ° C., Under the condition of a vacuum degree of 0.7 Pa, the low molecular component was first removed and then separated from the high molecular weight component to obtain a main fraction. The obtained release agent 5 had DSC characteristics with an endothermic peak of DSC of 85 ° C. and a half-value width of 17 ° C.
The ratio of normal hydrocarbons in the release agent 5 was 97%.
-Preparation of release agent dispersion 5-
In the same manner as the release agent dispersion 1, a release agent dispersion 5 having a volume average particle size of 0.21 μm and a release agent concentration of 31.0% was prepared.

-Preparation of release agent 6 and dispersion thereof-
FT wax H1 manufactured by Sasol is used as a raw material, and distilled using a centrifugal molecular distillation apparatus (MS-380) manufactured by Nippon Vehicle Co., Ltd. under conditions of an evaporation surface temperature of 240 ° C. to 300 ° C. and a vacuum degree of 0.7 Pa. The component was removed and later separated from the high molecular weight component to obtain a main fraction. The obtained release agent 6 had DSC characteristics with an endothermic peak of 90 ° C. and a half width of 9 ° C. of DSC.
The ratio of normal hydrocarbons in the release agent 6 was 96%.
-Preparation of release agent dispersion 6-
In the same manner as the release agent dispersion 1, a release agent dispersion 6 having a volume average particle size of 0.23 μm and a release agent concentration of 31.0% was prepared.

-Preparation of release agent 7 and dispersion thereof-
A material obtained by melt blending 70 parts of Paraffin HNP9 manufactured by Nippon Seiwa Co., Ltd. and 30 parts of FT wax C80 manufactured by Sasol Co., Ltd. was used as a raw material, and the evaporation surface temperature was 240 using a centrifugal molecular distillation apparatus (MS-380) manufactured by Nippon Vehicle Co., Ltd. Distillation was carried out under the conditions of from 300 ° C. to 300 ° C. and a vacuum degree of 0.7 Pa. First, the low molecular component was removed, and then separated from the high molecular weight component to obtain a main fraction. The obtained release agent 7 had DSC characteristics with an endothermic peak of DSC of 75 ° C. and a half width of 9 ° C.
The ratio of normal hydrocarbons in the release agent 7 was 93%.
-Preparation of release agent dispersion 7-
In the same manner as the release agent dispersion 1, a release agent dispersion 7 having a volume average particle size of 0.2 μm and a release agent concentration of 31.0% was prepared.

-Preparation of release agent 8 and dispersion thereof-
30 parts of Sasol FT Wax H1 and 40 parts of C80 and 30 parts of Shell FT Wax 105 were blended as raw materials, and evaporated on a centrifugal molecular distillation apparatus (MS-380) manufactured by Nippon Vehicle Co., Ltd. Distillation was carried out under the conditions of a temperature of 240 ° C. to 300 ° C. and a degree of vacuum of 0.7 Pa. First, low molecular components were removed and then separated from high molecular weight components to obtain a main fraction. The obtained release agent 8 had DSC characteristics with an endothermic peak of DSC of 85 ° C. and a half-value width of 20 ° C.
The ratio of normal hydrocarbons in the release agent 8 was 94%.
-Preparation of release agent dispersion 8-
In the same manner as the release agent dispersion 1, a release agent dispersion 8 having a volume average particle size of 0.24 μm and a release agent concentration of 31.0% was prepared.

-Preparation of release agent 9 and dispersion thereof-
60 parts of microcrystalline wax Himic1090 manufactured by Nippon Seiwa Co., Ltd., 40 parts of FT wax C80 manufactured by Sasol Co., Ltd., and a raw material of melt blended material, was evaporated using a centrifugal molecular distillation apparatus (MS-380) manufactured by Nippon Vehicle Co., Ltd. Distillation was performed at 240 ° C. to 300 ° C. under a vacuum degree of 0.7 Pa. First, low molecular components were removed and then separated from high molecular weight components to obtain a main fraction. The obtained release agent 9 had DSC characteristics with an endothermic peak of DSC of 84 ° C. and a half-value width of 13 ° C.
The ratio of normal hydrocarbons in the release agent 9 was 82%.
-Preparation of release agent dispersion 9-
In the same manner as in the release agent dispersion 1, a release agent dispersion 9 having a volume average particle size of 0.25 μm and a release agent concentration of 31.0% was prepared.

-Preparation of mold release agent 10 and dispersion thereof-
Evaporation surface temperature in a centrifugal molecular distillation apparatus (MS-380) manufactured by Nippon Vehicle Co., Ltd. using 80 parts of microcrystalline wax Himic1090 manufactured by Nippon Seiwa Co., Ltd. and 20 parts of FT wax C80 manufactured by Sasol Co. as a raw material. Distillation was performed at 240 ° C. to 300 ° C. under a vacuum degree of 0.7 Pa. First, low molecular components were removed and then separated from high molecular weight components to obtain a main fraction. The obtained release agent 10 had DSC characteristics with an endothermic peak of DSC of 83 ° C and a half-value width of 13 ° C.
The ratio of normal hydrocarbons in the release agent 10 was 77%.
-Preparation of release agent dispersion 10-
In the same manner as in the release agent dispersion 1, a release agent dispersion 10 having a volume average particle diameter of 0.25 μm and a release agent concentration of 31.0% was prepared.

-Preparation of release agent 11 and dispersion thereof-
A material obtained by melt blending 30 parts of Sasol FT wax H1 and 70 parts of Shell FT wax 105 each with a centrifugal molecular distillation apparatus (MS-380) manufactured by Nippon Vehicle Co., Ltd. from an evaporation surface temperature of 240 ° C. Distillation was carried out under the conditions of 300 ° C. and a degree of vacuum of 0.7 Pa. First, low molecular components were removed and then separated from high molecular weight components to obtain a main fraction. The obtained release agent 11 had DSC characteristics with an endothermic peak of DSC of 95 ° C. and a half-value width of 13 ° C.
The ratio of normal hydrocarbons in the release agent 11 was 95%.
-Preparation of release agent dispersion 11-
In the same manner as the release agent dispersion 1, a release agent dispersion 11 having a volume average particle size of 0.25 μm and a release agent concentration of 31.0% was prepared.

[Example 1]
(Preparation of Toner 1)
<Preparation of Toner Particle 1>
Amorphous polyester resin dispersion 1 313.75 parts Release agent dispersion 1 59.516 parts Colorant dispersion 1 61.316 parts Crystalline polyester resin dispersion 52.926 parts Ion exchange water 445 Part / anionic surfactant 2.25 parts As a flocculant while adding the above raw materials to a polymerization kettle equipped with a pH meter, stirring blades, and thermometer, and applying shear force at 6000 rpm with Ultraturrax (manufactured by IKA Japan). 100 parts of a 1% aqueous solution of aluminum sulfate was added dropwise to prepare a raw material mixture.

  Next, the raw material mixture was stirred at 550 to 650 rpm while being heated to 30 ° C. with a mantle heater. After stirring for 60 minutes, it was confirmed that the primary particle size was formed using a Coulter Multisizer type II (aperture diameter: 50 μm, manufactured by Coulter, Inc.), and then the temperature was increased at 0.5 ° C./minute to grow aggregated particles. Warm up. The agglomerated particle size was confirmed at any time using a Coulter Multisizer type II. When the volume average particle diameter of the aggregated particles becomes 6.3 μm, 175 parts of the amorphous polyester resin dispersion liquid diluted with 48 parts of ion-exchanged water is added to cover the aggregated particles, and the aggregated particles (adhesion particles) In order to stop the growth of EDTA, 10.0 parts of an EDTA aqueous solution (Kyles 40 manufactured by Kires Co., diluted to 12% concentration with ion-exchanged water) and 1M aqueous sodium hydroxide solution were added in order, and the pH of the raw material mixture was adjusted. Control to 8.0. Subsequently, in order to fuse the aggregated particles, the temperature was raised to a coalescence temperature of 90 ° C. at a heating rate of 1 ° C./min. After confirming that the aggregated particles were fused with an optical microscope, the volume average particle size 6 was cooled. Toner particles of 5 μm were obtained.

  Next, the obtained slurry was filtered, and ion-exchanged water having a toner solid content of 10 times was added, dispersed and stirred for 10 minutes, and filtration was repeated 5 times to wash the toner. Vacuum drying was performed to obtain toner particles 1 having a volume average particle diameter of 6.6 μm.

0.9 parts and 0.6 parts of silica powder (particle diameter: 50 nm) and titania powder (particle diameter: 40 nm) as external additives are added to 1: 100 parts of the toner particles prepared above, respectively, and a Henschel mixer is added. To obtain toner 1.
Table 1 shows the complex elastic modulus, volume average particle diameter (D50), and release agent dispersion diameter (D16, D50, D84) of Toner 1 at 80 ° C.

  Next, toner 1 is weighed so that the toner concentration is 5% with respect to a ferrite carrier having a volume average particle diameter of 35 μm coated with 1% of polymethyl methacrylate resin (Mw: 80000, manufactured by Soken Chemical Co., Ltd.), and ball mill The developer 1 was prepared by stirring and mixing for 5 minutes.

<Evaluation>
-Blocking-
Using a modified DocuCenter f1100 machine manufactured by Fuji Xerox as an image forming apparatus, a solid image (210 mm × 100 mm) with a toner loading of 8.0 g / m ² was continuously printed on P paper manufactured by Fuji Xerox. The applied amount of toner was set to about twice the normal setting for easy comparison of the blocking characteristics. The fixing set temperature was 180 ° C. The degree of set-off (blocking) of the printed material deposited 10 minutes after the completion of printing was evaluated based on the following criteria. The obtained results are shown in Table 1.
<Evaluation criteria>
○: There is no sticking between papers and there is no image loss △: There is a slight sticking between papers, but there is no image loss ×: Paper sticks between papers, and the image is back when it is peeled off Move to the side

-Smudge-
Using a DocuCenter f1100 manufactured by Fuji Xerox Co., Ltd. as an image forming apparatus, a full-text image (16 pt) having a toner loading of 8.0 g / m ² was printed on Business 80 paper manufactured by Fuji Xerox. The printed paper was fed 20 times using a DCF1100GA automatic document feeder, and the degree of image show-through (smudge) was evaluated based on the following criteria. The obtained results are shown in Table 1.
Smudge is a phenomenon in which when a fixed toner image is rubbed with a blank sheet, a part of the toner image is broken and moved to a rubbed blank sheet.
<Evaluation criteria>
○: The image is not smudged when rubbed with white paper. △: The image is smudged when rubbed with white paper, but its density is less than 0.15 (X-rite) and is slight. When it is rubbed, image stains are attached, and the density is 0.15 (X-rite) or more, which is a problem.

-Minimum fixing temperature-
conditions:
-Teflon (registered trademark) hard roll heat fixing device (Fuji Xerox DocuCentre f1100 fixing device)
・ Heating time by nip: 21msec
・ Nip surface pressure: 6.0 kgf / cm ²
・ Fixing speed 535mm / sec,
・ Paper Business 80 (basis weight 80g / m ² )
-Solid image with an image toner amount of 5.0 g / m ^2- Fixability determination The temperature at which the removal width when folded is less than 0.5 mm is the maximum fixing temperature. Fixing was performed from the low temperature side in steps, and the temperature satisfying the fixing property was set as the minimum fixing temperature.

[Examples 2 to 8, Comparative Examples 1 to 7]
According to the toner composition shown in Table 1, toners 2 to 15 and developers 2 to 15 were prepared in the same manner as toner 1, and evaluated in the same manner as in Example 1. The obtained results are shown in Table 1.

  The toners of the examples had good results in print blocking, feeder smudge, and low-temperature fixability. On the other hand, the toner of the comparative example has insufficient or non-uniform seepage of the release agent to the fixed image surface, or due to a shortage of the polymer side component in the release agent, Problems occurred in print blocking and feeder smudge, and the melting behavior of the toner was not in an appropriate range, so that the low-temperature fixability was insufficient or blocking could not be prevented.

[Example 9]
The cyan toner (toner 16) and development were performed in the same manner as the toner 1 except that the colorant dispersion 2 was used instead of the colorant dispersion 1, and the amount of the EDTA aqueous solution was changed from 10.0 parts to 20.0 parts. An agent was prepared.
This color toner was evaluated in the same manner as in Example 1 using a DocuCentre-III C7600 remodeling machine (fixing set temperature decreased by 15 ° C.). As a result, good results were obtained for the toner 16 in terms of print blocking, feeder smudge, and low-temperature fixability.

1Y, 1M, 1C, 1K, 107 photoconductor (image carrier)
2Y, 2M, 2C, 2K, 108 Charging roller 3Y, 3M, 3C, 3K Laser beam 3, 110 Exposure device 4Y, 4M, 4C, 4K, 111 Developing device (developing means)
5Y, 5M, 5C, 5K Primary transfer rollers 6Y, 6M, 6C, 6K, 113 Photoconductor cleaning device (cleaning means)
8Y, 8M, 8C, 8K Toner cartridge 10Y, 10M, 10C, 10K Unit 20 Intermediate transfer belt 22 Drive roller 24 Support roller 26 Secondary transfer roller (transfer means)
28, 115 Fixing device (fixing means)
30 Intermediate transfer member cleaning device 112 Transfer device 116 Mounting rail 117 Opening 118 for static elimination exposure Opening 200 for exposure Process cartridge,
P, 300 Recording paper (transfer object)

Claims (7)

A release agent having an endothermic peak determined by a differential scanning calorimeter (DSC) in a range of 70 ° C. or higher and 95 ° C. or lower, and a half-value width of the endothermic peak in a range of 10 ° C. or higher and 18 ° C. or lower; A polyester resin, an amorphous polyester resin, and a colorant,
The complex elastic modulus at 80 ° C. is 5 × 10 ⁴ Pa or more and 5 × 10 ⁵ Pa or less,
The dispersion diameter of the release agent in the toner is 0.3 μm or more and 0.8 μm or less as a particle size (D50) that is 50% in the cumulative distribution under sieve based on the number measurement, and the cumulative distribution under sieve based on the number measurement. An electrophotographic toner having a particle diameter (D84) of 84% at 1.1 μm or less.   The electrophotographic toner according to claim 1, wherein the release agent is paraffin wax having a normal hydrocarbon ratio of 80% by mass or more. A release agent having an endothermic peak determined by a differential scanning calorimeter (DSC) in a range of 70 ° C. or higher and 95 ° C. or lower and a half width of the endothermic peak in a range of 10 ° C. or higher and 18 ° C. or lower was dispersed. Mixing a release agent dispersion, a crystalline polyester resin dispersion in which a crystalline polyester resin is dispersed, an amorphous polyester resin dispersion in which an amorphous polyester resin is dispersed, and a colorant dispersion in which a colorant is dispersed An agglomerated particle dispersion preparing step for preparing a dispersion of aggregated particles containing the release agent, the crystalline polyester resin, the amorphous polyester resin, and the colorant;
The toner for electrophotography according to claim 1, further comprising a fusing / merging step of fusing and coalescing the aggregated particles by heating to an endothermic peak temperature of ± 10 ° C. of the release agent. Method.   An electrophotographic developer comprising the electrophotographic toner according to claim 1.   A toner cartridge containing at least toner, wherein the toner is the toner for electrophotography according to claim 1.   A process cartridge comprising at least a developer holder and containing the electrophotographic developer according to claim 4.   The photosensitive member, charging means for charging the photosensitive member, electrostatic charge image forming means for forming an electrostatic charge image on the surface of the charged photosensitive member, and the electrostatic charge image formed on the photosensitive member. An image forming apparatus comprising: a developing unit that develops a toner image with the electrophotographic developer according to 4; a transfer unit that transfers the toner image onto a transfer target; and a fixing unit that fixes the toner image.