JP2007212871A - Toner for electrostatic image development, method for manufacturing the same, electrostatic image developer and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner for electrostatic image development excellent in low-temperature fixability and document offset resistance and providing image quality free from uneven gloss in a high temperature and high humidity environment. <P>SOLUTION: The toner for electrostatic image development has a core-shell structure, wherein the core part has a glass transition temperature of 20-40°C, the shell part has a glass transition temperature of 50-100°C, the core part contains inorganic particles having a particle diameter of 0.1-0.5 μm and a specific gravity of 1.0-2.0, and the toner has an intermediate layer containing a nonpolar hydrocarbon compound between the core and shell parts, the intermediate layer having a thickness of 0.1-0.9 μm. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrostatic charge image developing toner used when developing an electrostatic latent image formed by an electrophotographic method, an electrostatic recording method or the like, a manufacturing method thereof, an electrostatic charge image developer, and an image forming method.

  A method of visualizing image information through an electrostatic charge image such as electrophotography is currently used in various fields. In electrophotography, an electrostatic charge image is formed on a photoreceptor by charging and exposure processes, the electrostatic latent image is developed with a developer containing toner, and visualized through a transfer and fixing process.

  As the developer used here, a two-component developer composed of a toner and a carrier and a one-component developer using a magnetic toner or a non-magnetic toner alone are known. As a method for producing the toner, a kneading and pulverizing method is generally used in which a thermoplastic resin is melt-kneaded together with a release agent such as a pigment, a charge control agent, and a wax, and after cooling, finely pulverized and classified to obtain a toner. In these toners, inorganic and organic particles are added to the surface of the toner particles as necessary for the purpose of improving fluidity and cleaning properties. Although these methods can produce a considerably good toner, they have several problems as follows.

  In a normal kneading and pulverizing method, the toner shape and the surface structure of the toner are indeterminate, and change slightly depending on the pulverization properties of the materials used and the conditions of the pulverization process, so it is difficult to control the toner shape and the surface structure. . In the kneading and pulverizing method, the range of material selection is limited. Specifically, it is preferable that the resin colorant dispersion is sufficiently brittle and can be finely pulverized by an ordinary pulverizer. However, if the resin colorant dispersion is fragile, the toner is subjected to mechanical shearing force in the developing machine. May generate fine powder or change the toner shape. In the two-component developer, the generated fine powder adheres to the carrier surface and accelerates the deterioration of the chargeability of the developer. With the one-component developer, toner scattering occurs due to the expansion of the particle size distribution, or development due to a change in toner shape. The image quality is likely to deteriorate.

  In addition, a toner in which a large amount of a release agent such as wax is internally added often affects the exposure of the release agent to the toner surface in combination with a thermoplastic resin. In particular, in the case of a combination of a resin that has increased elasticity due to a high molecular weight component and is slightly pulverized, and a brittle wax such as polyethylene, a large amount of polyethylene is exposed on the toner surface. Although this toner is advantageous for releasability at the time of fixing and cleaning of untransferred toner from the surface of the photoreceptor, the polyethylene on the surface layer can be easily transferred to the developing roll, photoreceptor, carrier, etc. by the mechanical force and contaminated. Reduce reliability.

  Furthermore, if the toner shape is indefinite, the fluidity of the toner cannot be sufficiently ensured even if a flow aid is added, and the fine powder moves to the toner recesses due to mechanical shearing force during use. The fluidity decreases with time, or the fluidity aid is buried in the toner, and the developability, transferability, and cleaning properties are deteriorated. In addition, when the toner collected by the cleaning is returned to the developing machine and used again, the image quality is liable to deteriorate. In order to prevent these problems, if the flow aid is further increased, black spots are generated on the photoconductor and the aid particles are scattered.

  As described above, in the electrophotographic process, the toner remains stable even under various mechanical stresses, so that the exposure of the release agent to the toner surface is suppressed and the fixing property is not impaired. In addition to increasing the surface hardness, it is important to achieve both improvement in the mechanical strength of the toner itself and sufficient charging and fixing properties.

  Further, in recent years, there has been a growing demand for higher image quality, and in particular in the formation of color images, there is a significant tendency to reduce the diameter of toner in order to realize high-definition images. However, if the particle size distribution is simply reduced while maintaining the conventional particle size distribution, the presence of the toner on the fine powder side causes significant contamination of the carrier and photoconductor, and toner scattering, so that high image quality and high reliability can be realized at the same time. difficult. In order to solve this problem, it is important to sharpen the particle size distribution of the toner and to make it possible to reduce the particle size.

  In recent years, in digital full-color copiers and printers, color image originals are separated by B (blue), R (red), and G (green) filters, and then the dot diameter is in the range of 20 to 70 μm corresponding to the original original. The latent image is developed using Y (yellow), M (magenta), C (cyan), and Bk (black) developers and utilizing a subtractive color mixing effect, but digital full color compared to conventional black and white machines. In copiers and the like, it is necessary to transfer a large amount of developer, and further, it is necessary to cope with a small dot diameter. Therefore, uniform chargeability, durability, toner strength, and sharpness of particle size distribution are increasingly important. From these points, the aggregation and fusion method suitable for the production of a toner having a sharp particle size distribution and a small particle size is excellent.

  It is important for a toner mounted on a full-color copying machine or the like that a large amount of toner is mixed with certainty, and improvement of color reproducibility and OHP transparency at that time are essential. Further, as a means for controlling the toner shape and the surface structure thereof, a toner production method using an emulsion polymerization aggregation method has been proposed (see, for example, Patent Documents 1 and 2). In these methods, a resin particle dispersion is generally prepared by emulsion polymerization or the like, while a colorant dispersion in which a colorant is dispersed in a solvent is prepared and mixed to form aggregated particles corresponding to the toner particle size. Then, the toner is manufactured by heating and fusing and coalescing. When this method is used, not only the toner having a sharp particle size distribution and a small particle diameter can be produced, but also the toner shape can be controlled and the exposure of the release agent to the toner surface can be suppressed.

  Generally, a thermoplastic resin is used in these electrophotographic toners, and the rheology of the binder resin used for the toner and the glass transition temperature (Tg) in order to achieve both low energy fixing and powder blocking properties. It has been proposed to optimize the control (see, for example, Patent Documents 3, 4, and 5). In recent electrophotographic processes, a binder resin having a lower glass transition temperature has been used in order to cope with an increase in fixing speed in response to the demand for the advancement of digitization and high speed as described above. Yes.

  However, when a toner image containing this type of binder resin is heated to a temperature near or above the glass transition temperature, the resin component of the image portion melts and adheres to the back side of the printed matter or other printed matter. However, a problem that an image is lost, that is, a document offset problem occurs. In recent years, double-sided printing has been increasing. However, in double-sided output, image portions are inevitably brought into contact with each other, and thus image loss is more likely to occur than in single-sided output.

  In order to improve the offset problem of the fixed output image, that is, the document offset, the thermosetting resin is externally added to the toner to cause the polyester binder resin to undergo a curing reaction, so that the document offset and the low temperature fixability are achieved. (See, for example, Patent Document 6).

  However, there is a demand for low energy fixing due to the recent movement toward strong environmental conservation, demand for double-sided printing, use of coated paper with poor toner penetration at the time of fixing, and half-fixed image as a response to high image quality. There are various stress requirements, such as a request for fixing with tones, etc., and it is becoming difficult to achieve both of these characteristics by acquiring document offset (image loss) at the time of low-temperature fixing only with such technology. Is the current situation.

  In addition, in order to achieve both low-temperature fixing properties and document offset properties, toners with other resins added to binder resins with lower glass transition temperatures are used between different types of resins due to stress load in the developing unit. Compatibility tends to proceed, and this tendency is remarkable in a high-temperature and high-humidity environment, and the functions of low-temperature fixing property and document offset property are difficult to be exhibited, and uneven gloss of image quality occurs. In particular, due to the recent popularization and diversification of copiers and the like and high image quality requirements, there are increasing demands for use and high image quality in high temperature and high humidity environments.

Japanese Patent Laid-Open No. 63-282275 JP-A-6-250439 JP-B-2-37586 JP-A-1-225967 Japanese Patent Laid-Open No. 2-235069 JP-A-4-186368

  Accordingly, the present invention solves the above problems, is excellent in low-temperature fixability and document offset property, and is excellent in uniformity of glossiness of image quality under high temperature and high humidity, and its toner. An object of the present invention is to provide a manufacturing method, a developer for developing an electrostatic image, and an image forming method.

  As a result of intensive studies to overcome the above problems, the present inventors have found that the above-described problems can be solved by adopting the following configuration, and have completed the present invention.

The present invention has the following features.
(1) It has a core-shell structure, the core part has a glass transition point of 20 to 40 ° C., the shell part has a glass transition point of 50 to 100 ° C., the core part has a particle size of 0.1 to 1.0 μm, and a specific gravity of 1 An electrostatic charge having an intermediate layer containing inorganic particles of 0.0 to 3.0 and containing a hydrocarbon compound between the core portion and the shell portion, and the thickness of the intermediate layer is 0.1 to 0.4 μm Toner for image development.

(2) The toner for developing an electrostatic charge image according to the above (1), wherein the thickness of the shell layer is in the range of 0.1 to 0.9 μm.

(3) A method for producing a toner for developing an electrostatic charge image having a core-shell structure, in which a resin particle dispersion for core in which resin particles constituting a core part having a particle size of 1.0 μm or less are dispersed, and a colorant A step of mixing a dispersion, an inorganic particle dispersion, and a release agent dispersion to prepare a dispersion of first agglomerated particles containing resin particles for a core, a colorant, inorganic particles, and a release agent; The dispersion of the first agglomerated particles is mixed with the dispersion of the hydrocarbon compound and the resin particle dispersion for the shell in which the resin particles constituting the shell portion are dispersed, and the first agglomerated particles, the hydrocarbon compound, and the shell are mixed. Fusing the second agglomerated particles by preparing a dispersion of the second agglomerated particles containing resin particles for heating, and heating to a temperature above the glass transition point of the shell resin constituting the resin particles for shells A method for producing an electrostatic charge image developing toner comprising: .

  (4) In the electrostatic charge developer containing a carrier and a toner, the carrier has a resin coating layer, and the toner is the electrostatic image developing toner according to (1) or (2). An electrostatic charge image developer characterized.

  (5) forming an electrostatic latent image on the electrostatic charge image bearing member; developing the electrostatic latent image with a developer on the developer bearing member to form a toner image; and In the image forming method including the step of transferring onto the transfer member, the step of transferring the toner image on the transfer member onto the fixing sheet, and the step of thermally fixing the toner image, (4 An image forming method using the electrostatic image developer described in (1).

  According to the present invention, it is possible to provide an image quality that is excellent in low-temperature fixability, excellent in document offset property, and free from image loss in a high-temperature and high-humidity environment.

  Hereinafter, the toner for developing an electrostatic charge image (hereinafter referred to as “toner”) of the present invention, a manufacturing method thereof, an electrostatic charge image developer, and an image forming method will be described in detail.

<Electrostatic image developing toner and method for producing the same>
The toner of the present invention may be produced by any method such as a kneading and pulverizing method, a polymerization method, and a heteroaggregation method, but generally a dispersion of resin particles produced by emulsion polymerization or the like is used. The colorant dispersion, inorganic particle dispersion, and nonpolar hydrocarbon compound particle dispersion dispersed in the ionic surfactant having the opposite polarity are mixed with each other to generate heteroaggregation, which corresponds to the toner diameter. The aggregated particles are formed and then heated to a temperature above the glass transition temperature of the resin so that the aggregated particles are fused and united, washed and dried to obtain a toner. The toner shape can be appropriately manufactured from an irregular shape to a spherical shape. Can do. In the toner of the present invention, a release agent particle dispersion may be added as appropriate.

  In particular, the method for producing a toner for developing an electrostatic charge image having a core-shell structure according to the present invention includes a resin particle dispersion liquid for a core in which resin particles constituting a core portion having a particle size of 1.0 μm or less are dispersed, and a colorant. A step of mixing a dispersion, an inorganic particle dispersion, and a release agent dispersion to prepare a dispersion of first agglomerated particles containing resin particles for a core, a colorant, inorganic particles, and a release agent; The dispersion of the first agglomerated particles is mixed with the dispersion of the hydrocarbon compound and the resin particle dispersion for the shell in which the resin particles constituting the shell portion are dispersed, and the first agglomerated particles, the hydrocarbon compound, and the shell are mixed. Fusing the second agglomerated particles by preparing a dispersion of the second agglomerated particles containing resin particles for heating, and heating to a temperature above the glass transition point of the shell resin constituting the resin particles for shells And a process of uniting.

  Further preferably, the method is a method in which the raw material dispersion is mixed and agglomerated together, but the balance of the amount of the polar ionic dispersant is shifted in advance at the initial stage of the agglomeration process, for example, This is ionically neutralized using a polymer of an inorganic metal salt such as calcium nitrate or an inorganic metal salt such as polyaluminum chloride, and the first-stage core agglomerated particles (ie, the first Agglomerated particles) are formed and stabilized, and then a dispersion containing non-polar hydrocarbon compound particles (that is, second agglomerated particles) is added as a second step, and core agglomerated particles or After stabilization by slightly heating at a high temperature below the glass transition temperature or melting point of the resin contained in the additional particles, particles of polarity and quantity so as to compensate for the above-mentioned balance deviation as the third stage After adding a dispersion and further stabilizing by slightly heating at a high temperature below the glass transition temperature of the resin contained in the core aggregated particles or additional particles, if necessary, then heating above the glass transition temperature The particles added in the third stage are fused and united while adhering to the surface of the core aggregated particles.

  The toner used in the present invention has a core-shell structure. A toner that has a low-temperature fixability function at the glass transition point of the core, a document offset resistance function at the glass transition point of the shell, and has both the core and shell functions at the time of fixing and images. It is. The glass transition point of the core part is in the range of 20 to 40 ° C. Preferably, the thing of the range of 20-30 degreeC is used. When the glass transition point is lower than 20 ° C., the probability that the resin component at the low glass transition point of the core portion is exposed on the surface of the fixed image is increased, and the document offset property of the fixed image is lowered. On the other hand, when the temperature exceeds 40 ° C., the low glass transition point component of the core portion hardly contributes at the time of fixing, and the low temperature fixing property is impaired. Further, the shell part has a glass transition point of 50 to 100 ° C., and preferably 60 to 80 ° C. When the glass transition point is lower than 50 ° C., the resin component having a high glass transition point does not exist on the image surface after fixing, and the document offset property of the fixed image is lowered.

For the measurement of the glass transition point (Tg) of the toner of the present invention, for example, DSC-7 (differential thermal analyzer) manufactured by Perkin Elmer is used. The temperature correction of the detection part of the apparatus uses the melting points of indium and zinc, and the correction of heat quantity uses the heat of fusion of indium. For the sample, an aluminum pan is used, and an empty pan is set as a control, and measurement is performed at a heating rate of 10 ° C./min. For calculation of the peak area of the molecular weight, the peak area is sliced for each retention time range, and the distribution ratio is obtained from the area ratio.

In the present invention, the document offset property is determined as follows. A toner is uniformly deposited at a rate of 5.0 g / m ² on a sheet of 40 × 40 mm in an electrostatic field of 10 KV, and this is processed at a process speed of 100 mm / sec, a nip pressure of 2.5 Kg / cm ² , A sample is obtained by fixing at a temperature of 160 ° C. Using these two, the fixed images are brought into contact with each other and left in an atmosphere of 60 ° C. for 7 days under a load of 80 g / cm ² . Thereafter, they are peeled off, and the presence or absence of document offset is visually confirmed and evaluated.

[Inorganic particles]
The toner used in the present invention contains inorganic particles having a particle size of 0.1 to 0.5 μm and a specific gravity of 1.0 to 2.0 in the core portion. The inorganic particles having a relatively small particle size and a small specific gravity are added to the core portion of the toner in the core-shell type toner having two kinds of glass transition points so that these inorganic particles are imaged during fixing. It becomes easy to exist on the surface, and the probability that the low glass transition point component of the core portion of the toner resin component exists on the surface can be reduced. As a result, it is possible to suppress the presence of a core resin component having a low glass transition point on the image surface and to maintain the document offset property at the time of low-temperature fixing, as compared with the above-described ordinary core-shell type toner. It becomes. Therefore, it is possible to achieve both compatibility under low-temperature fixing and document offset characteristics, which are more stressful than conventional methods, such as higher speed, lower energy fixing, and halftone fixing image. The inorganic particles can be added by a wet method. As the inorganic particles to be added, any of those usually used as external additives on the toner surface, such as silica, alumina, titania, calcium carbonate, magnesium carbonate, and tricalcium phosphate, can be used. It is preferable to use by dispersing with a molecular acid or a polymer base. The center diameter of the inorganic particles in the obtained inorganic particle dispersion is measured, for example, with a laser diffraction particle size distribution analyzer (LA-700, manufactured by Horiba, Ltd.). The center diameter of the inorganic particles is 0.1 to 1.0 μm, preferably 0.1 to 0.5 μm. If it is less than 0.1 μm, the particle diameter is too small and it is difficult to be present on the image surface during fixing. On the other hand, when the thickness exceeds 1.0 μm, internal addition to the core is difficult, and exposure to the toner surface may occur. The specific gravity of the inorganic particles is 1.0 to 3.0, preferably 1.5 to 2.5. If it is less than 1.0, it becomes difficult to obtain an inorganic particle dispersion, or exposure to the toner surface occurs when the toner is added inside the toner. On the other hand, if it exceeds 3.0, it becomes difficult to exist on the image surface at the time of fixing due to an increase in specific gravity. The method for measuring the specific gravity of the inorganic particles is shown below.

[Hydrocarbon compounds]
The toner of the present invention has an intermediate layer containing a hydrocarbon compound between the core portion and the shell portion. Since this intermediate layer is nonpolar, it exists as a blocking layer between the core and shell resins without being mixed. For this reason, compatibility between the core and shell resin can be prevented even under stress in the developer in a high-temperature, high-humidity environment. It becomes easy to demonstrate. In addition, since the functional separation between the low glass transition point resin and the high glass transition point resin is clear, it is possible to suppress the uneven distribution of different resin components due to their compatibility, and uniform smoothness provides an image with no gloss unevenness. be able to.

  The thickness of the layer containing the hydrocarbon compound is suitably in the range of 0.1 to 0.4 μm, preferably in the range of 0.2 to 0.4 μm. When the thickness of the layer is less than 0.1 μm, the establishment of compatibility between the core-shell resin layers increases, making it difficult to achieve both low-temperature fixability and document offset property, and uneven glossiness occurs in a high-temperature and high-humidity environment. Further, if the thickness of the layer exceeds 0.4 μm, the compatibility between the resin layers can be prevented, but the low glass transition point component becomes difficult to function at the time of fixing, so that the low temperature fixing property is lowered.

  The content of the hydrocarbon compound of the present invention is suitably in the range of 5 to 25 parts by weight, preferably 5 to 20% by weight in terms of solid content per toner weight. When the content is less than 5% by weight, compatibility between the resin layers cannot be prevented, and when the content exceeds 25 parts by weight, the toner surface is easily exposed or the fluidity is liable to be lowered.

  The hydrocarbon compounds used in the present invention are, for example, low molecular weight polyolefins such as polyethylene, polypropylene, polybutene; minerals such as montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, microcrystalline wax, and Fischer-Trosch wax. , Petroleum waxes; and their modifications.

  The above hydrocarbon compound is dispersed in water together with a polymer electrolyte such as an ionic surfactant, a polymer acid or a polymer base, heated to a temperature higher than the melting point, and subjected to strong shearing with a homogenizer or a pressure discharge type disperser. Into a dispersion of particles of 1 μm or less. In the present invention, as described above, the addition amount of the nonpolar hydrocarbon compound dispersed in the toner is suitably in the range of 5 to 25 parts by weight with respect to the toner parts by weight.

  The hydrocarbon compound used in the present invention is preferably a substance having a main maximum endothermic peak measured in accordance with ASTM D3418-8 in the range of 50 to 100 ° C. If it is less than 50 ° C., an offset tends to occur during fixing. On the other hand, if the temperature exceeds 100 ° C., the fixing temperature becomes high, and the smoothness of the surface of the fixed image cannot be obtained and the glossiness is impaired. For the measurement of the main maximum endothermic peak of the present invention, for example, DSC-7 (differential thermal analyzer) manufactured by PerkinElmer can be used. The temperature correction of the detection part of the apparatus uses the melting points of indium and zinc, and the correction of heat quantity uses the heat of fusion of indium. As the sample, an aluminum pan is used, an empty pan is set as a control, and the measurement is performed at a heating rate of 10 ° C./min.

  The thickness of the shell layer of the toner of the present invention is suitably in the range of 0.1 to 0.9 μm, preferably in the range of 0.2 to 0.8 μm. When the thickness of the shell layer is less than 0.1 μm, the probability that the low glass transition point component of the core portion is exposed on the image surface after fixing increases, and the document offset property becomes insufficient. On the other hand, when the thickness of the shell layer exceeds 0.9 μm, the low glass transition point component of the core part hardly contributes at the time of fixing, and the low-temperature fixability is lowered.

  The cumulative volume average particle diameter D50 of the toner of the present invention is suitably in the range of 3-9 μm, preferably in the range of 3-8 μm. When D50 is less than 3 μm, the chargeability becomes insufficient and the developability may be lowered, and when it exceeds 9 μm, the resolution of the image is lowered. The particle size of the toner is, for example, a particle size range divided based on the particle size distribution measured using a measuring device such as Coulter Counter TAII (manufactured by Nikka Kisha) or Multisizer II (manufactured by Nikka Kisha). A cumulative distribution is drawn from the smaller diameter side for each of the volume and number for (channel), and the particle size at which 50% of the accumulation is achieved is defined as volume D50v and number D50p.

[Resin particles]
The polymer used for the core and shell resin particles of the present invention is not particularly limited, and examples thereof include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, and acrylic acid n. Esters having a vinyl group such as propyl, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate Vinyl nitriles such as acrylonitrile and methacrylonitrile; vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl isopropenyl ketone; ethylene, propylene, Polymers such as monomers such as polyolefins such as dienes or copolymers obtained by combining two or more of these, or a mixture thereof, as well as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, Examples thereof include polyether resins, non-vinyl condensation resins, mixtures of these with the vinyl resins, and graft polymers obtained by polymerizing vinyl monomers in the presence of these resins.

  The vinyl monomer can be emulsion-polymerized using an ionic surfactant or the like to prepare a resin particle dispersion. Other resins are those that are oily and soluble in a solvent with relatively low solubility in water. Dissolve the resin in those solvents and dissolve it in water with a disperser such as a homogenizer along with an ionic surfactant or polymer electrolyte. The resin particle dispersion can be prepared by dispersing the particles in the mixture and then heating or reducing the pressure to evaporate the solvent.

[Colorant]
The colorant of the present invention is selected from the viewpoints of hue angle, saturation, brightness, weather resistance, OHP transparency, and dispersibility in the toner. For example, examples of the black pigment include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, nonmagnetic ferrite, and magnetite. Examples of the yellow pigment include yellow lead, zinc yellow, yellow iron oxide, cadmium yellow, chrome yellow, Hansa yellow, Hansa yellow 10G, benzidine yellow G, benzidine yellow GR, selenium yellow, quinoline yellow, permanent yellow NCG and the like. Is mentioned.

  Examples of the orange pigment include red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, benzidine orange G, indanthrene brilliant orange RK, indanthrene brilliant orange GK and the like. Red pigments include Bengala, cadmium red, red lead, mercury sulfide, watch young red, permanent red 4R, risor red, brilliantamine 3B, brilliantamine 6B, dapon oil red, pyrazolone red, rhodamine B rake, lake red C , Rose bengal, oxin red, alizarin lake and the like.

  Blue pigments include bitumen, cobalt blue, alkali blue rake, Victoria blue rake, fast sky blue, indanthrene blue BC, aniline blue, ultramarine blue, calco oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite green oxare. Rate and so on. Examples of purple pigments include manganese purple, fast violet B, and methyl violet lake. Examples of the green pigment include chromium oxide, chromium green, pigment green, malachite green lake, final yellow green G, and the like.

  Examples of white pigments include zinc white, titanium oxide, antimony white, and zinc sulfide. Examples of extender pigments include barite powder, barium carbonate, clay, silica, white carbon, talc, and alumina white. Examples of the dye include various dyes such as basic, acidic, dispersed, and direct dyes, such as nigrosine, methylene blue, rose bengal, quinoline yellow, and ultramarine blue. These pigments and dyes can be used alone or in combination, and further in a solid solution state.

  These colorants can be dispersed in the dispersion by a known method. For example, a rotary shear type homogenizer, a media mill such as a ball mill, a sand mill, or an attritor, a high-pressure counter collision type disperser, or the like is preferable. Used. In the present invention, the addition amount of the colorant dispersed in the toner is suitably in the range of 4 to 15 parts by weight with respect to 100 parts by weight of the toner. In addition, when using a magnetic body as a black coloring agent, the range of 30-100 weight part is suitable unlike other coloring agents.

[Release agent]
Known release agents may be used, such as paraffin wax and derivatives thereof, montan wax and derivatives thereof, microcrystalline wax and derivatives thereof, Fischer-Tropsch wax and derivatives thereof, polyolefin wax and derivatives thereof, and the like. is there. This derivative includes an oxide, a polymer with a vinyl monomer, and a graft modified product. In addition, alcohols, fatty acids, plant waxes, animal waxes, mineral waxes, ester waxes, acid amides and the like can be mentioned, but the invention is not limited thereto.

  Further, when the toner is used as a magnetic toner, magnetic powder may be contained. As the magnetic powder, a material that is magnetized in a magnetic field is used, and a ferromagnetic powder such as iron, cobalt, or nickel, or a compound such as ferrite or magnetite is used. In the present invention, since the toner is produced in the aqueous phase, attention must be paid to the aqueous phase migration of the magnetic material. The surface is preferably modified and used, for example, after being subjected to a hydrophobic treatment.

  The shape factor SF1 of the toner of the present invention is preferably in the range of 110 to 145 from the viewpoint of image formability. The shape factor SF1 is calculated as an average value of (the maximum length squared / projected area) × 100π / 4, for example, by the following method. That is, an optical microscope image of the toner dispersed on the slide glass is taken into a Luzex image analyzer through a video camera, and 50 toners are calculated to obtain an average value. Note that π is a circumference ratio.

  In the toner of the present invention, a charge control agent can be used in order to further improve and stabilize the chargeability. As the charge control agent, various commonly used charge control agents such as quaternary ammonium salt compounds, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium and triphenylmethane pigments can be used. A material that is difficult to dissolve in water is preferable from the viewpoint of controlling the ionic strength that affects the stability of aggregation, fusion, and temporary combination and reducing wastewater contamination.

  To the toner of the present invention, inorganic particles can be added in a wet manner in order to stabilize the chargeability. As the inorganic particles to be added, any of those usually used as external additives on the toner surface, such as silica, alumina, titania, calcium carbonate, magnesium carbonate, and tricalcium phosphate, can be used. It is preferable to use by dispersing with a molecular acid or a polymer base.

  In addition, the toner of the present invention, after the toner is dried for the purpose of imparting fluidity and improving cleaning properties, inorganic particles such as silica, alumina, titania and calcium carbonate, and resin particles such as vinyl resin, polyester and silicone are used. It is preferable to add to the toner surface while applying shear.

  In the toner production method of the present invention, as a surfactant used for emulsion polymerization, resin particle dispersion, colorant dispersion, release agent dispersion, aggregation, or stabilization thereof, for example, sulfate salt type, sulfonate type Anionic surfactants such as phosphate esters and soaps, cationic surfactants such as amine salts and quaternary ammonium salts, polyethylene glycols, alkylphenol ethylene oxide adducts, polyhydric alcohols, etc. It is also effective to use a nonionic surfactant in combination. As the dispersing means, a rotary shear type homogenizer, a ball mill having a media, a sand mill, a dyno mill, or the like can be used.

  In the case of using a composite consisting of a resin and a colorant, the resin and the colorant are dissolved and dispersed in a solvent, and then dispersed in water together with the appropriate dispersant, and the solvent is removed by heating and decompression. Alternatively, it can be prepared and prepared by a method of applying mechanical shearing force to the surface of resin particles prepared by emulsion polymerization or a method of electrically adsorbing and fixing. These methods are effective in suppressing the liberation of the colorant as additional particles and improving the chargeable colorant dependency.

  After completion of the polymerization, a desired toner is obtained through any washing step, solid-liquid separation step, and drying step. In the washing step, it is preferable to sufficiently perform substitution washing with ion-exchanged water from the viewpoint of chargeability. The solid-liquid separation step is not particularly limited, but suction filtration, pressure filtration and the like are preferable from the viewpoint of productivity. The drying process is not particularly limited, but freeze drying, flash jet drying, fluidized drying, vibration fluidized drying and the like are preferably used from the viewpoint of productivity.

  In the present invention, it is possible to provide an image quality that is excellent in low-temperature fixability and excellent in document offset by adopting the above configuration.

<Electrostatic image developer>
The toner of the present embodiment is used as a one-component developer composed only of toner or a two-component developer composed of toner and carrier, but a two-component developer excellent in charge maintenance and stability is preferable. The carrier is preferably a carrier coated with a resin, and more preferably a carrier coated with a nitrogen-containing resin.

  Examples of the nitrogen-containing resin include resins obtained by polymerizing acrylic monomers including dimethylaminoethyl methacrylate, dimethylacrylamide, acrylonitrile, amino resins including urea, urethane, melamine, guanamine, aniline, and amide resins. A urethane resin is mentioned. These copolymer resins may also be used.

  As the carrier coating resin, two or more of the nitrogen-containing resins may be used in combination. Moreover, you may use combining the said nitrogen containing resin and resin which does not contain nitrogen. The nitrogen-containing resin may be used in the form of particles and dispersed in a resin not containing nitrogen. In particular, a urea resin, a urethane resin, a melamine resin, a guanamine resin, and an amide resin are preferable because they have high positive chargeability and high resin hardness, and can suppress a decrease in charge amount due to peeling of the coating resin.

  Furthermore, it is also preferable from the viewpoint of improving reliability that the resin coating layer contains a (meth) acrylic acid alkyl ester having a branched alkyl group. That is, by introducing a (meth) acrylic acid alkyl ester having an alkyl group having a branched structure, it is possible to achieve both adhesion and surface contamination prevention at a high level. Here, when the alkyl group having the branched structure has 3 or less carbon atoms, the above properties cannot be imparted. The upper limit of the number of carbon atoms is 20, and if it exceeds this, brittleness of the polymer itself becomes remarkable, and the coating film becomes too soft and adversely affects the storability and fluidity of the carrier. Therefore, it is preferable to use a material having suitable performance as a coating material having 4 to 20 carbon atoms. Specific examples of the (meth) acrylic acid alkyl ester having a branched alkyl group include tertiary butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, neo-pentyl (meth) acrylate, Examples thereof include those having a structure in which one or more alkyl groups such as a methyl group are substituted with respect to an ester portion carbon chain such as isopentyl (meth) acrylate. Moreover, the (meth) acrylic-acid alkylester which has a fluorine-containing alkyl group can also be used together. The surface energy of the coating resin can be lowered by the fluorine-containing alkyl group, and toner adhesion to the charge imparting member and the carrier can be prevented. The fluorine-containing alkyl group is not particularly limited, and an appropriate one can be used in consideration of the balance between the ability of the carrier to impart surface contamination resistance and the softness of the coating film. Specific examples of the (meth) acrylic acid alkyl ester having a fluorine-containing alkyl group include trifluoroethyl (meth) acrylate, tetrafluoroethyl (meth) acrylate, perfluoropentyl (meth) acrylate, perfluoropentylethyl (meta ) Acrylate, perfluorooctyl (meth) acrylate, perfluorooctylethyl (meth) acrylate, perfluorododecyl (meth) acrylate, and the like.

In general, the carrier needs to have an appropriate electric resistance value, and specifically, an electric resistance value of about 10 ⁸ to 10 ¹⁴ Ωcm is required. For example, when the electrical resistance value is as low as 10 ⁶ Ωcm as in the case of an iron powder carrier, the carrier adheres to the image portion of the photoreceptor due to the charge injection from the sleeve, or the latent image charge escapes through the carrier and the latent Problems such as image distortion and image loss occur. On the other hand, if the insulating resin is coated thickly, the electrical resistance value becomes too high and carrier charges are difficult to leak, resulting in an edged image. This causes a problem of an edge effect that the image density of the image becomes very thin. Therefore, it is preferable to disperse the conductive fine powder in the resin coating layer in order to adjust the resistance of the carrier.

The carrier resistance is obtained by an ordinary electrode plate type electric resistance measurement method in which carrier particles are sandwiched between two electrode plates and a current is applied when a voltage is applied, and is ^103.8 V / cm. Evaluation is based on resistance under an electric field.

The electric resistance of the conductive powder itself is preferably 10 ⁸ Ωcm or less, and more preferably 10 ⁵ Ωcm or less. Specific examples of conductive powder include metals such as gold, silver and copper; carbon black; conductive metal oxides such as titanium oxide and zinc oxide; titanium oxide, zinc oxide, aluminum borate and titanic acid. Examples thereof include a composite system in which the surface of particles such as potassium and tin oxide are coated with a conductive metal oxide. Carbon black is particularly preferable from the viewpoints of production stability, cost, and low electrical resistance. The type of carbon black is not particularly limited, but those having a DBP (dibutyl phthalate) oil absorption of 50 to 300 ml / 100 g with good production stability are preferred. The conductive powder preferably has a volume average particle size of 0.1 μm or less, and preferably has a volume average primary particle size of 50 nm or less for dispersion.

  Examples of the method for forming the resin coating layer on the surface of the carrier core material include an immersion method in which a powder of the carrier core material is immersed in the solution for forming the coating layer, and a solution for forming the coating layer on the surface of the carrier core material. Spray method for spraying, fluidized bed method for spraying the solution for forming the coating layer in a state where the carrier core material is floated by the flowing air, and a kneader for mixing the carrier core material and the solution for forming the coating layer in a kneader coater to remove the solvent. Examples of the coater method include a powder coating method in which a coating resin is formed into particles and mixed at a temperature equal to or higher than the melting point of the coating resin in a carrier core material and a kneader coater, and then cooled to form a coating.

  The average film thickness of the resin coating layer formed by the above method is usually 0.1 to 10 μm, preferably 0.2 to 5 μm.

  The core material (carrier core material) used in the electrostatic latent image developing carrier of the present embodiment is not particularly limited, and magnetic metals such as iron, steel, nickel and cobalt, or magnetism such as ferrite and magnetite. An oxide, a glass bead, etc. are mentioned, From the viewpoint of using the magnetic brush method, a magnetic carrier is desirable. As an average particle diameter of a carrier core material, generally 10-100 micrometers is preferable and 20-80 micrometers is more preferable.

  The mixing ratio (weight ratio) between the electrostatic charge developing toner of the present embodiment and the carrier in the two-component developer is in the range of toner: carrier = 1: 100 to 30: 100, and 3: 100. The range of about 20: 100 is more preferable.

<Image forming method>
Next, the image forming method of the present invention will be described.

  The image forming method of the present invention is formed on the surface of the latent image holding body using a latent image forming step of forming an electrostatic latent image on the surface of the latent image holding body and a developer carried on the developer carrying body. A developing process for developing the electrostatic latent image to form a toner image, a transfer process for transferring the toner image formed on the surface of the latent image holding body to the surface of the transfer target, and the image transferred to the surface of the transfer target And a fixing step of thermally fixing the toner image, wherein the developer is at least a developer containing the electrostatic image developing toner of the present invention. The developer may be either a one-component system or a two-component system.

  As each of the above steps, a known step in the image forming method can be used.

  As the latent image holding member, for example, an electrophotographic photosensitive member and a dielectric recording member can be used. In the case of an electrophotographic photosensitive member, the surface of the electrophotographic photosensitive member is uniformly charged by a corotron charger, a contact charger or the like and then exposed to form an electrostatic latent image (latent image forming step). Next, the toner particles are adhered to the electrostatic latent image in contact with or in proximity to a developing roll having a developer layer formed on the surface, thereby forming a toner image on the electrophotographic photosensitive member (developing step). The formed toner image is transferred onto the surface of a transfer medium such as paper using a corotron charger or the like (transfer process). Further, the toner image transferred to the surface of the transfer target is heat-fixed by a fixing device, and a final toner image is formed.

  In the heat fixing by the fixing machine, a release agent is usually supplied to a fixing member in the fixing machine in order to prevent an offset or the like.

  The method for supplying the release agent to the surface of the roller or belt, which is a fixing member used for heat fixing, is not particularly limited. For example, a pad method using a pad impregnated with a liquid release agent, a web method, a roller method. Non-contact shower method (spray method) and the like, and the web method and the roller method are particularly preferable. These methods are advantageous in that the release agent can be supplied uniformly and it is easy to control the supply amount. In order to supply the release agent uniformly to the entire fixing member by the shower method, it is necessary to use a separate blade or the like.

  FIG. 1 is a schematic configuration diagram showing a configuration example of an image forming apparatus for forming an image by the image forming method of the present invention. The illustrated image forming apparatus 100 is a tandem color image forming apparatus.

  The image forming apparatus 100 receives color image information sent from a personal computer (not shown), color image information of a color original read by the image data input device or the image reading device 102, and the like. Image processing is performed on the information.

  1Y, 1M, 1C, and 1K are electrophotographic image forming units that form toner images of colors of yellow, magenta, cyan, and black, respectively, in the traveling direction of the endless intermediate transfer member 9 stretched by a plurality of rollers. On the other hand, they are arranged in series in the order of 1Y, 1M, 1C, and 1K. The intermediate transfer member 9 is a transfer means 6Y, 6M, 6C disposed opposite to the electrostatic latent image carriers 2Y, 2M, 2C, 2K of the electrophotographic image forming units 1Y, 1M, 1C, 1K. , 6K.

  Here, the image forming operation on the intermediate transfer member 9 will be described by taking the electrophotographic image forming unit 1Y for forming a yellow toner image as an example.

  First, the surface of the electrostatic latent image carrier 2Y is uniformly charged by the uniform charger 3Y. Next, image exposure corresponding to the yellow image is performed by the exposure device 4Y, and an electrostatic latent image corresponding to the yellow image is formed on the surface of the electrostatic latent image carrier 2Y. The electrostatic latent image corresponding to the yellow image is converted into a yellow toner image by the developing device 5Y, and is transferred onto the intermediate transfer member 9 by the pressing force and electrostatic attraction force of the primary transfer roller 6Y constituting a part of the primary transfer means. The The yellow toner remaining on the electrostatic latent image carrier 2Y after the transfer is scraped off by the electrostatic latent image carrier cleaning device 7Y. The surface of the electrostatic latent carrier 2Y is neutralized by the static eliminator 8Y and then charged again by the uniform charger 3Y for the next image forming cycle.

  In this image forming apparatus 100 that performs multicolor image formation, an image similar to the above is obtained at a predetermined timing in consideration of the relative position difference between the electrophotographic image forming units 1Y, 1M, 1C, and 1K. The forming process is also performed in the electrophotographic image forming units 1M, 1C, and 1K, and a full color toner image is formed on the intermediate transfer member 9.

  Next, the recording paper 18 supplied by a recording paper supply means described later is conveyed to a secondary transfer position of the intermediate transfer body 9 at a predetermined timing by a plurality of conveyance rollers 19 and registration rollers 20. The full-color toner image formed on the intermediate transfer member 9 constitutes a part of the backup roller 13 that supports the intermediate transfer member 9 and the secondary transfer unit that is in pressure contact with the backup roller 13 on the recording paper 18. The secondary transfer roller 12 is collectively transferred by the pressing force and electrostatic attraction force of the secondary transfer roller 12. Here, the residual toner on the intermediate transfer body 9 that could not be transferred to the recording paper 18 by the secondary transfer means is transported to the intermediate transfer body cleaning device 14 in a state of adhering to the intermediate transfer body 9 as it is, and the cleaning means 14. Thus, it is removed from the intermediate transfer member 9 to prepare for the next image formation.

  Further, the recording paper 18 onto which the full color toner image has been transferred from the intermediate transfer body 9 has a fixing belt 47 disposed after being separated from the intermediate transfer body 9 and downstream in the transport direction of the secondary transfer means. The toner image is conveyed to the belt fixing device 101, where the toner image is fixed and glossed on the recording paper 18 by heat and pressure, and discharged to a predetermined discharge tray. In order to achieve more reliable fixing, a fixing device including two opposing rollers may be further provided in the front stage of the belt fixing device 101.

  Next, a recording paper supply unit and a roll recording paper supply unit according to the present invention will be described.

  First, recording paper (coated paper or the like) 18P to be subjected to gloss processing other than roll recording paper is fed from a paper feed cassette 17A as recording paper supply means arranged at the lower part in the image forming apparatus 100 as shown in FIG. The recording paper of a predetermined size is fed by the paper feed roller 17a. When a recording paper size other than the predetermined size stored in the paper feed cassette 17A is selected, the roll recording paper 18R is fed from the roll recording paper unit 17B, which is a roll paper loading unit, by the paper feed roller 17b. After being fed out, it is appropriately cut into a predetermined size by the cutting unit 17c and conveyed by a plurality of conveying rollers 19, thereby constituting a roll recording paper supply means. Here, when the roll recording paper 18R is conveyed and reaches the belt fixing device 101, the positional relationship between the surface of the roll recording paper 18R and the belt surface 47 of the belt fixing device 101 is as follows. It is inevitably determined by the arrangement relationship (installation direction) with the conveyance path of the unit 17B, the image forming units 1Y, 1M, 1C, and 1K, the belt fixing device 101, and the like.

  Therefore, in the image forming apparatus 100 according to the present invention, an unfixed toner image is formed on the inner surface located on the center side of the roll recording paper 18R in the state accommodated in the roll recording paper unit 17B. The image forming units 1Y, 1M, 1C, and 1K, the belt fixing device 101, and the like are disposed. For example, a gloss sensor for discriminating the front and back of the roll recording paper 18R stored and conveyed is provided in the roll recording paper unit 17B, and when the roll recording paper 18R is conveyed and reaches the belt surface 47 of the belt fixing device 101. Then, a predetermined surface (for example, the inner surface) such that the inner surface of the roll recording paper 18R faces the belt surface 47 is detected in the conveyance path in the roll recording paper unit 17B. Further, when a surface (for example, an outer surface) opposite to the predetermined surface is detected, the supply of the roll recording paper 18R is stopped, and a warning is displayed to the operator that the roll recording paper 18R is incorrectly installed. It is configured as follows. In order to prevent the roll recording paper 18R from being misplaced, for example, a fitting member that fits a roll shaft (a rotating member that supports the roll recording paper 18R) in the center of the accommodated roll recording paper 18R. And a mechanical stopper may be provided so that the roll recording paper 18R can be set only in a predetermined direction by forming a predetermined fitting structure between the fitting member and the roll shaft. However, when a surface other than the predetermined surface of the roll recording paper 18R is detected in the conveyance path, the roll recording paper 18R may be controlled to be forcibly discharged. Further, a rotation direction restricting unit may be provided so that the roll recording paper 18R can rotate only in a predetermined direction. In addition, about the cutting part 17c, the existing roll recording paper cutter can be used suitably.

  By configuring and arranging the devices of the image forming apparatus 100 as described above, the inner surface (the concave surface due to curling) of the roll recording paper 18R is always the belt in the relationship between the roll recording paper 18R and the belt fixing device 101 described later. Roll recording paper 18 </ b> R is supplied so as to face the belt surface 47 of the fixing device 101.

  In FIG. 1, when a toner image is subjected to fixing and gloss processing on a recording paper 18 (an example of an image output medium) by heat and pressure in a belt fixing device 101 having a fixing belt 47, 95 It is desirable to perform heat-fixing in a temperature range of 95 ° C. to 120 ° C., preferably 95 ° C. to 110 ° C.

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

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by these.

  First, in this example, each measurement was performed as follows.

-Particle size and particle size distribution measurement method-
The particle size (also referred to as “particle size”) and particle size distribution measurement (also referred to as “particle size distribution measurement”) will be described.

  When the particle diameter to be measured was 2 μm or more, a Coulter counter TA-II type (manufactured by Beckman-Coulter) was used as the measuring apparatus, and ISOTON-II (manufactured by Beckman-Coulter) was used as the electrolyte.

  As a measurement method, 0.5 to 50 mg of a measurement sample is added to 2 ml of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate, as a dispersant. This was added to 100 ml of the electrolytic solution.

  The electrolyte solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute, and the particle size distribution of particles of 2 to 60 μm is measured using the Coulter counter TA-II type with an aperture diameter of 100 μm. Volume average distribution and number average distribution were determined. The number of particles to be measured was 50,000.

  The particle size distribution of the toner was determined by the following method. For the particle size range (channel) obtained by dividing the measured particle size distribution, draw the volume cumulative distribution from the smaller particle size, define the cumulative number particle size to be 16% cumulative as D16p, and the cumulative volume to be 50% cumulative. The particle size is defined as D50v. Furthermore, the cumulative number particle size that is 84% cumulative is defined as D84p.

The volume average particle diameter in the present invention is D50v, and the GSDp under the small diameter side number average particle size index was calculated by the following formula.
Formula: Lower GSDp = {(D84p) / (D16p)} ^0.5

  Moreover, when the particle diameter to measure was less than 2 micrometers, it measured using the laser diffraction type particle size distribution measuring apparatus (LA-700: made by Horiba, Ltd.). As a measurement method, a sample in a dispersion is adjusted to have a solid content of about 2 g, and ion exchange water is added thereto to make about 40 ml. This is put into the cell until an appropriate concentration is reached, waits for about 2 minutes, and is measured when the concentration in the cell becomes almost stable. The obtained volume average particle diameter for each channel was accumulated from the smaller volume average particle diameter, and the volume average particle diameter was determined to be 50%.

  When measuring powders such as external additives, 2 g of a measurement sample is added to 50 ml of a 5% aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate, and 2 with an ultrasonic disperser (1,000 Hz). A sample was prepared by dispersing for a minute, and the measurement was performed in the same manner as the above dispersion.

-Method of measuring toner shape factor SF1-
The shape factor SF1 of the toner is a shape factor SF indicating the degree of unevenness on the toner particle surface, and was calculated by the following equation.
Formula: SF1 = (ML ² / A) × (π / 4) × 100
In the formula, ML represents the maximum length of toner particles, and A represents the projected area of the particles. For the measurement of the shape factor SF1, first, an optical microscope image of toner dispersed on a slide glass was taken into an image analysis device through a video camera, and SF was calculated for 50 or more toners to obtain an average value.

-Measuring method of melting point and glass transition temperature-
The melting point and the glass transition temperature of the toner were determined by a DSC (Differential Scanning Calorimeter) measurement method, and were determined from the main maximum peak measured according to ASTM D3418-8.

  DSC-7 manufactured by Perkin Elmer Co. can be used for measurement of the main maximum peak. The temperature correction of the detection part of this apparatus uses the melting point of indium and zinc, and the correction of heat quantity uses the heat of fusion of indium. As the sample, an aluminum pan was used, an empty pan was set as a control, and the measurement was performed at a heating rate of 10 ° C./min.

-Measurement of specific gravity of inorganic particles-
The specific gravity was measured according to JIS-K-0061 5-2-1 using a Le Chatelier specific gravity bottle. The operation is as follows.
(1) About 250 ml of ethyl alcohol is put into a Lechatelier specific gravity bottle and adjusted so that the meniscus is at the position of the scale.
(2) The specific gravity bottle is immersed in a constant temperature water bath, and when the liquid temperature reaches 20.0 ± 0.2 ° C., the position of the meniscus is accurately read with the scale of the specific gravity bottle. (Accuracy 0.025ml)
(3) About 100.000 g of a sample is weighed and its mass is designated as W.
(4) Put the weighed sample in a specific gravity bottle to remove bubbles.
(5) The specific gravity bottle is immersed in a constant temperature water bath, and when the liquid temperature becomes 20.0 ± 0.2 ° C., the position of the meniscus is accurately read with the scale of the specific gravity bottle. (Accuracy 0.025ml)
(6) The specific gravity is calculated by the following formula.
(Equation 2)
D = W / (L2-L1)-(1)
S = D / 0.9982 (2)
In the formula, D is the density of the sample (20 ° C) (g / cm ³ ), S is the specific gravity of the sample (20 ° C), W is the apparent mass of the sample (g), and L1 is before the sample is placed in the specific gravity bottle. Meniscus reading (20 ° C.) (ml), L2 is the meniscus reading (20 ° C.) (ml) after placing the sample in a pycnometer, 0.9982 is the density of water at 20 ° C. (g / cm ³ ) It is.

  For the toner of the present invention, the following resin particle dispersion, colorant dispersion, inorganic particle dispersion, release agent dispersion, and hydrocarbon compound dispersion were prepared, and these were mixed at a predetermined ratio and stirred. Then, a polymer of an inorganic metal salt is added thereto and ionically neutralized to form aggregated particles. After adjusting the pH of the system from weakly acidic to neutral with an inorganic hydroxide, it is heated to a temperature higher than the glass transition temperature of the resin particles to be fused and united. Thereafter, the desired toner is obtained through sufficient steps of washing, solid-liquid separation, and drying. Hereinafter, each preparation method is demonstrated.

(Preparation of resin particle dispersion 1)
Styrene (manufactured by Wako Pure Chemical Industries) 200 parts by weight n-butyl acrylate (manufactured by Wako Pure Chemical Industries) 200 parts by weight β-carboxyethyl acrylate (manufactured by Rhodia Nikka) 9 parts by weight 1,10-decanediol diacrylate (manufactured by Shin-Nakamura Chemical) ) 1.5 parts by weight dodecanethiol (manufactured by Wako Pure Chemical Industries, Ltd.) 2.7 parts by weight The above is mixed and dissolved, and this is ion-exchanged water 550 containing 4 parts by weight of the anionic surfactant Dowfax (manufactured by Dow Chemical). Dissolved in a weight, further dispersed and emulsified in a flask, and slowly stirred and mixed for 10 minutes, and then charged with 50 parts by weight of ion-exchanged water in which 6 parts by weight of ammonium persulfate was dissolved. Next, after sufficiently replacing the nitrogen in the system, the system was heated in an oil bath while stirring the flask until it reached 70 ° C., and emulsion polymerization was continued for 5 hours. As a result, an anionic resin particle dispersion 1 having a volume average particle size of 196 nm and a glass transition point of 28.3 ° C. was obtained.

(Preparation of resin particle dispersion 2)
Resin particle dispersion 2 was obtained in the same manner as in the preparation of resin particle dispersion 1, except that 210 parts by weight of styrene and 190 parts by weight of n-butyl acrylate were used in the adjustment of resin particle dispersion 1. The volume average particle size was 195 nm and the glass transition point was 32.1 ° C.

(Preparation of resin particle dispersion 3)
Resin particle dispersion 3 was obtained in the same manner as the resin particle dispersion 1 except that 230 parts by weight of styrene and 170 parts by weight of n-butyl acrylate were used in the adjustment of the resin particle dispersion 1. The volume average particle size was 199 nm and the glass transition point was 35.5 ° C.

(Preparation of resin particle dispersion 4)
In the adjustment of the resin particle dispersion 1, a resin particle dispersion 4 was obtained in the same manner as in the adjustment of the resin particle dispersion 1, except that 250 parts by weight of styrene and 150 parts by weight of n-butyl acrylate were used. The volume average particle diameter was 200 nm and the glass transition point was 38.9 ° C.

(Preparation of resin particle dispersion 5)
In the adjustment of the resin particle dispersion 1, a resin particle dispersion 5 was obtained in the same manner as the adjustment of the resin particle dispersion 1, except that 315 parts by weight of styrene and 75 parts by weight of n-butyl acrylate were used. The volume average particle size was 201 nm, and the glass transition point was 54.2 ° C.

(Preparation of resin particle dispersion 6)
Resin particles were prepared in the same manner as in the resin particle dispersion 1, except that 330 parts by weight of styrene, 70 parts by weight of n-butyl acrylate, and 9.5 parts by weight of β-carboxyethyl acrylate were used in the preparation of the resin particle dispersion 1. Dispersion 6 was obtained. The volume average particle size was 198 nm and the glass transition point was 58.7 ° C.

(Preparation of resin particle dispersion 7)
Resin particle dispersion 7 was obtained in the same manner as in the preparation of resin particle dispersion 1, except that 360 parts by weight of styrene and 40 parts by weight of n-butyl acrylate were used in the adjustment of resin particle dispersion 1. The volume average particle size was 202 nm and the glass transition point was 62.4 ° C.

(Preparation of resin particle dispersion 8)
Resin particle dispersion 8 was obtained in the same manner as in the preparation of resin particle dispersion 1, except that 375 parts by weight of styrene and 25 parts by weight of n-butyl acrylate were used in the adjustment of resin particle dispersion 1. The volume average particle size was 199 nm and the glass transition point was 68.2 ° C.

(Preparation of resin particle dispersion 9);
A resin particle dispersion 9 was obtained in the same manner as the resin particle dispersion 1 except that the resin particle dispersion 1 was adjusted to 394 parts by weight of styrene and 6 parts by weight of n-butyl acrylate. The volume average particle size was 200 nm, and the glass transition point was 96.3 ° C.

(Preparation of resin particle dispersion 10);
Resin particle dispersion 10 was obtained in the same manner as in the preparation of resin particle dispersion 1, except that 400 parts by weight of styrene and no n-butyl acrylate were contained in the adjustment of resin particle dispersion 1. The volume average particle size was 200 nm and the glass transition point was 106.1 ° C.

(Preparation of inorganic particle dispersion 1)
Silica sol (specific gravity 1.6) 50 parts by weight anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 5 parts by weight ion-exchanged water 200 parts by weight The above was mixed, and a homogenizer (manufactured by IKA, Ultra Turrax 750). ) For 10 minutes, and then subjected to a circulating ultrasonic disperser (manufactured by Nippon Seiki Seisakusho, RUS-600TCVP) to obtain an inorganic particle dispersion 1 containing silica particles having a center diameter of 0.4 μm.

(Preparation of inorganic particle dispersion 2)
Silica sol (specific gravity 3.0) 50 parts by weight Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 5 parts by weight Ion-exchanged water 200 parts by weight The above was mixed and homogenizer (IKA, Ultra Turrax 750). ) For 10 minutes, and then subjected to a circulating ultrasonic disperser (manufactured by Nippon Seiki Seisakusho, RUS-600TCVP) to obtain an inorganic particle dispersion 1 containing particles having a center diameter of 0.4 μm.

(Preparation of inorganic particle dispersion 3)
Silica sol (specific gravity 1.8) 50 parts by weight Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 5 parts by weight Ion-exchanged water 200 parts by weight The above was mixed and homogenizer (IKA, Ultra Turrax 750). ) For 10 minutes, and then subjected to a circulating ultrasonic disperser (manufactured by Nippon Seiki Seisakusho, RUS-600TCVP) to obtain an inorganic particle dispersion 3 containing silica particles having a center diameter of 1.1 μm.

(Preparation of inorganic particle dispersion 4);
Silica sol (specific gravity 2.5) 50 parts by weight Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 5 parts by weight Ion-exchanged water 200 parts by weight The above was mixed and homogenizer (IKA, Ultra Turrax 750). ) Was applied for 10 minutes, and then subjected to a circulating ultrasonic disperser (manufactured by Nippon Seiki Seisakusho, RUS-600TCVP) to obtain inorganic particle dispersion 4 containing silica particles having a center diameter of 0.6 μm.

(Preparation of inorganic particle dispersion 5);
Silica sol (specific gravity 0.5) 50 parts by weight anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 5 parts by weight ion-exchanged water 200 parts by weight The above was mixed and homogenizer (IKA, Ultra Turrax 750). ) Was used for 10 minutes, and then subjected to a circulating ultrasonic disperser (manufactured by Nippon Seiki Seisakusho, RUS-600TCVP) to obtain an inorganic particle dispersion 5 containing silica particles having a center diameter of 0.3 μm.

(Preparation of inorganic particle dispersion 6);
Silica sol (specific gravity 1.9) 50 parts by weight anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 5 parts by weight ion-exchanged water 200 parts by weight The above was mixed, and a homogenizer (manufactured by IKA, Ultra Turrax 750). ) For 10 minutes, and then subjected to a circulating ultrasonic disperser (manufactured by Nippon Seiki Seisakusho, RUS-600TCVP) to obtain an inorganic particle dispersion 6 containing silica particles having a center diameter of 0.1 μm.

(Preparation of inorganic particle dispersion 7);
Silica sol (specific gravity 2.2) 50 parts by weight Anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 5 parts by weight Ion-exchanged water 200 parts by weight The above was mixed, and a homogenizer (IKA, Ultra Turrax 750) was mixed. ) Was applied for 10 minutes, and then subjected to a circulating ultrasonic disperser (manufactured by Nippon Seiki Seisakusho, RUS-600TCVP) to obtain an inorganic particle dispersion 7 containing silica particles having a center diameter of 1.0 μm.

(Preparation of hydrocarbon compound dispersion 1)
Paraffin wax (manufactured by Nippon Seiwa Co., Ltd., HNP0190, melting point 85 ° C.) 50 parts by weight Cationic surfactant (manufactured by Kao Corporation, Sanizol B50) 5 parts by weight Ion-exchanged water 200 parts by weight The above components are heated to 95 ° C., After sufficiently dispersing with a homogenizer (manufactured by IKA, Ultra Tarrax T50), it was dispersed with a pressure discharge type homogenizer to obtain a nonpolar hydrocarbon compound dispersion 1 containing particles having a center diameter of 200 nm.

(Preparation of hydrocarbon compound dispersion 2);
50 parts by weight of paraffin wax (manufactured by Nippon Seiwa Co., Ltd., paraffin wax HNP-9, melting point 75 ° C.)
Cationic surfactant (manufactured by Kao Corporation, Sanizol B50) 5 parts by weight ion-exchanged water 200 parts by weight After the above components were heated to 95 ° C. and sufficiently dispersed with a homogenizer (IKA, Ultra Turrax T50), Dispersion treatment was performed with a pressure discharge type homogenizer to obtain a nonpolar hydrocarbon compound dispersion 2 containing particles having a center diameter of 180 nm.

(Preparation of colorant dispersion 1)
Phthalocyanine pigment (manufactured by Dainichi Seika Co., Ltd., PVFASTBLUE) 90 parts by weight anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 10 parts by weight ion-exchanged water 240 parts by weight or more were mixed and homogenizer (manufactured by IKA, After dispersion for 10 minutes using an ultra turrax 750), a colorant particle dispersion 1 was prepared by applying to a circulating ultrasonic disperser (RUS-600TCVP, manufactured by Nippon Seiki Seisakusho). The number average particle diameter of the colorant in the colorant dispersion 1 was 150 nm.

(Preparation of colorant dispersion 2)
Carbon black (manufactured by CABOT, R330) 90 parts by weight anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 10 parts by weight ion-exchanged water 240 parts by weight Colorant particle dispersion 2 was prepared under the conditions. The number average particle diameter of the colorant in the colorant dispersion 2 was 155 nm.

(Preparation of colorant dispersion 3);
C. I. Pigment Yellow 74: (manufactured by Clariant) 90 parts by weight anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 10 parts by weight ion-exchanged water 240 parts by weight Thus, a colorant particle dispersion 3 was prepared. The number average particle diameter of the colorant in the colorant dispersion 3 was 260 nm.

(Preparation of colorant dispersion 4);
C. I. Pigment Red 122: (manufactured by Clariant) 90 parts by weight anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC) 10 parts by weight ion-exchanged water 240 parts by weight Thus, a colorant particle dispersion 4 was prepared. The number average particle diameter of the colorant in the colorant dispersion 4 was 220 nm.

;
(Preparation of release agent dispersion)
The following composition was mixed, heated to 97 ° C., and then dispersed with a homogenizer (manufactured by IKA, Ultra Turrax T50). Thereafter, the mixture was dispersed with a gorin homogenizer (manufactured by Kyowa Shoji Co., Ltd.) and treated 20 times under the conditions of 105 ° C. and 550 kg / cm ² to obtain a release agent dispersion having a volume average particle size of 190 nm.

Wax (WEP-2, manufactured by NOF Corporation) 25 parts by weight Anionic surfactant Neogen SC (Daiichi Kogyo Seiyaku Co., Ltd.) 5 parts by weight Ion-exchanged water 200 parts by weight After sufficiently dispersing with Lux T50, it was dispersed with a pressure discharge type gorin homogenizer to obtain a wax dispersion having a center diameter of 215 nm and a solid content of 19.5%.

(Manufacture of toner 1)
(Aggregation process)
Ion-exchanged water 500 parts by weight Resin particle dispersion 1 175 parts by weight Colorant dispersion 1 35 parts by weight Inorganic particle dispersion 1 10 parts by weight Flocculant (Asada Chemical Co., Ltd., polyaluminum chloride) 0.5 parts by weight or more The components were mixed and dispersed in a round stainless steel flask using a homogenizer (Ultra Turrax T50, manufactured by IKA). Thereafter, the agglomeration temperature was heated to 30 ° C. while stirring the flask in a heating oil bath. Thereafter, it was kept at 32 ° C. for 1.5 hours.

(Adhesion process 1)
40 parts by weight of the hydrocarbon compound dispersion 1 and 25 parts by weight of the resin particle dispersion 1 are mixed and slowly added to the prepared dispersion containing aggregated particles, and the temperature of the heating oil bath is raised to 34 ° C. Held for 1 hour.

(Adhesion process 2)
25 parts by weight of the resin particle dispersion 5 was gently added to the prepared dispersion containing aggregated particles, and the temperature of the heating oil bath was raised and maintained at 35 ° C. for 1 hour.

(Fusion process)
Next, after adding a 1 mol / liter aqueous sodium hydroxide solution to a pH of 6.0, the stainless steel flask was sealed, and gently heated to 85 ° C. while continuing stirring using a magnetic seal, Thereafter, the mixture was heated to 96 ° C., a 1 mol / liter nitric acid aqueous solution was added until the pH reached 5.0, and the mixture was held for 5 hours. Thereafter, the mixture was cooled, filtered, sufficiently washed with ion-exchanged water, and then dried using a vacuum dryer, thereby producing toner particles 1. The particle size was 5.3 μm, the thickness of the intermediate layer between the core-shell layers was 0.3 μm, and the average shell thickness was 0.4 μm.

(Manufacture of toner 2)
The resin particle dispersion 2 is used instead of the resin particle dispersion 1 in the aggregation step, the colorant dispersion 2 is used instead of the colorant dispersion 1, and the resin is used instead of the resin particle dispersion 1 in the adhesion step 1. Using the particle dispersion 2, the resin particle dispersion 6 was used instead of the resin particle dispersion 5 in the adhesion step 2. A toner 2 was obtained in the same manner as in the production of the toner 1 except that the heating temperature when the resin particle dispersion was added in the attaching step 2 was changed to 36 ° C. The particle diameter was 5.4 μm, the thickness of the intermediate layer between the core-shell layers was 0.4 μm, and the average shell thickness was 0.50 μm.

(Manufacture of toner 3);
In the aggregation step, 155 parts by weight of the resin particle dispersion 3 was used instead of the resin particle dispersion 1, and 45 parts by weight of the resin particle dispersion 7 was used in place of the resin particle dispersion 5 in the adhesion step 2. A toner 3 was obtained in the same manner as in the production of the toner 1 except that the heating temperature when adding the resin particle dispersion 7 in the attaching step 2 was changed to 37 ° C. The particle size was 6.3 μm, the thickness of the intermediate layer between the core-shell layers was 0.3 μm, and the average shell thickness was 0.74 μm.

(Manufacture of toner 4);
In the aggregation step, 160 parts by weight of the resin particle dispersion 4 is used in place of the resin particle dispersion 1, and the colorant dispersion 2 is used in place of the colorant dispersion 1, and is aggregated at 32 ° C. Change the hydrocarbon compound dispersion 1 to 45 parts by weight, use 40 parts by weight of the resin particle dispersion 8 in place of the resin particle dispersion 1 in the attachment step 2, and add the resin particle dispersion 8 in the attachment step 2. A toner 4 was obtained in the same manner as in the production of the toner 1 except that the heating temperature was changed to 37 ° C. The particle diameter was 6.5 μm, the thickness of the intermediate layer between the core and shell layers was 0.4 μm, and the average shell thickness was 0.6 μm.

(Manufacture of toner 5);
Changing the hydrocarbon compound dispersion 1 to the hydrocarbon compound dispersion 2 in the attaching step 1 and further changing the amount added to 30 parts by weight, and heating when adding the resin particle dispersion 5 in the attaching step A toner 5 was obtained in the same manner as in the production of the toner 1 except that the temperature was changed to 37 ° C. The particle size was 5.9 μm, the thickness of the intermediate layer between the core-shell layers was 0.2 μm, and the average shell thickness was 0.7 μm.

(Manufacture of toner 6);
In the aggregation process, 160 parts by weight of the resin particle dispersion 4 is used instead of the resin particle dispersion 1, and the colorant dispersion 3 is used instead of the colorant dispersion 1, and is aggregated at 32 ° C. Change the hydrocarbon compound dispersion 1 to 50 parts by weight, use 40 parts by weight of the resin particle dispersion 9 in place of the resin particle dispersion 1 in the attachment step 2, and add the resin particle dispersion 9 in the attachment step 2. The toner 6 was obtained in the same manner as in the production of the toner 1 except that the heating temperature was changed to 37 ° C. The particle size was 6.6 μm, the thickness of the intermediate layer between the core-shell layers was 0.4 μm, and the average shell thickness was 0.45 μm.

(Manufacture of toner 7);
In the aggregation step, 160 parts by weight of the resin particle dispersion 1 is used, the colorant dispersion 3 is used instead of the colorant dispersion 1, the inorganic particle dispersion 4 is used instead of the inorganic particle dispersion 1, and the temperature is 32 ° C. In the adhering step 1, the hydrocarbon compound dispersion 1 is changed to 45 parts by weight, the adhering step 2 uses 40 parts by weight of the resin particle dispersion 5, and the adhering step 2 uses the resin particle dispersion 5 in the adhering step 2. Toner 7 was obtained in the same manner as in the production of toner 1 except that the heating temperature at the time of addition was changed to 37 ° C. The particle size was 5.8 μm, the thickness of the intermediate layer between the core-shell layers was 0.3 μm, and the average shell thickness was 0.4 μm.

(Manufacture of toner 8);
In the aggregation process, 160 parts by weight of the resin particle dispersion 1 is used, the colorant dispersion 4 is used instead of the colorant dispersion 1, the inorganic particle dispersion 6 is used instead of the inorganic particle dispersion 1, and the temperature is 32 ° C. In the adhering step 1, the hydrocarbon compound dispersion 1 is changed to 40 parts by weight, in the adhering step 2, the resin particle dispersion 5 is used in 40 parts by weight, and in the adhering step 2, the resin particle dispersion 5 is used. Toner 8 was obtained in the same manner as in production of toner 1 except that the heating temperature at the time of addition was changed to 37 ° C. The particle size was 6.0 μm, the thickness of the intermediate layer between the core-shell layers was 0.3 μm, and the average shell thickness was 0.4 μm.

(Manufacture of toner 9);
In the aggregation step, 160 parts by weight of the resin particle dispersion 1 is used, the colorant dispersion 4 is used instead of the colorant dispersion 1, the inorganic particle dispersion 7 is used instead of the inorganic particle dispersion 1, and the temperature is 32 ° C. In the adhering step 1, the hydrocarbon compound dispersion 1 is changed to 30 parts by weight, and in the adhering step 2, 40 parts by weight of the resin particle dispersion 5 is used. In the adhering step 2, the resin particle dispersion 5 is used. Toner 9 was obtained in the same manner as in production of toner 1 except that the heating temperature at the time of addition was changed to 37 ° C. The particle diameter was 5.8 μm, the thickness of the intermediate layer between the core and shell layers was 0.4 μm, and the average shell thickness was 0.7 μm.

(Manufacture of toner 10)
A toner 10 was obtained in the same manner as in the production of the toner 1 except that the inorganic particle dispersion 2 was used instead of the inorganic particle dispersion 1. The particle size was 5.3 μm, the thickness of the intermediate layer between the core-shell layers was 0.4 μm, and the average shell thickness was 0.4 μm.

(Manufacture of toner 11)
A toner 11 was obtained in the same manner as in the production of the toner 1 except that the inorganic particle dispersion 3 was used instead of the inorganic particle dispersion 1. The particle size was 5.3 μm, the thickness of the intermediate layer between the core-shell layers was 0.3 μm, and the average shell thickness was 0.4 μm.

(Manufacture of toner 12)
A toner 12 was obtained in the same manner as in the production of the toner 1 except that the inorganic particle dispersion 1 was not added. The particle size was 5.3 μm, the thickness of the intermediate layer between the core-shell layers was 0.3 μm, and the average shell thickness was 0.4 μm.

(Manufacture of toner 13)
In the aggregation step, 170 parts by weight of the resin particle dispersion 5 is used instead of the resin particle dispersion 1, the aggregation temperature is 55 ° C., and the resin particle dispersion 6 is used instead of the resin particle dispersion 5 in the adhesion step 1. The hydrocarbon compound dispersion 1 was changed to 45 parts by weight, the resin particle dispersion 6 was used in 30 parts by weight instead of the resin particle dispersion 5 in the adhesion step 2, and the heating temperature was 59 ° C. In the same manner as in the production of toner 1, toner 13 was obtained. The particle size was 5.3 μm, the thickness of the intermediate layer between the core and shell layers was 0.4 μm, and the average shell thickness was 0.5 μm.

(Manufacture of toner 14)
Instead of the resin particle dispersion 1 in the aggregation step, 165 parts by weight of the resin particle dispersion 2 is used, and the hydrocarbon compound dispersion is changed to 45 parts by weight. In the same manner as in the production of the toner 1 except that the resin particle dispersion 4 is used in the adhesion step 2, 35 parts by weight of the resin particle dispersion 4 is used instead of the resin particle dispersion 5, and the heating temperature is 40 ° C. Thus, toner 14 was obtained. The particle size was 5.8 μm, the thickness of the intermediate layer between the core-shell layers was 0.5 μm, and the average shell thickness was 0.6 μm.

(Manufacture of toner 15)
In the aggregation step, 155 parts by weight of the resin particle dispersion 5 is used instead of the resin particle dispersion 1, the aggregation temperature is 55 ° C., and the resin particle dispersion 4 is used in place of the resin particle dispersion 5 in the adhesion step 1. The hydrocarbon compound dispersion 1 was changed to 50 parts by weight, 45 parts by weight of the resin particle dispersion 4 was used instead of the resin particle dispersion 5 in the adhesion step 2, and the heating temperature was 55 ° C. In the same manner as in the production of toner 1, toner 15 was obtained. The particle size was 5.9 μm, the thickness of the intermediate layer between the core-shell layers was 0.5 μm, and the average shell thickness was 0.8 μm.

(Manufacture of toner 16)
A toner 16 was obtained in the same manner as in the production of the toner 1 except that the hydrocarbon compound dispersion liquid 1 was not used in the attaching step 1. The particle size was 5.4 μm, and the shell average film thickness was 0.45 μm.

(Manufacture of toner 17)
A toner 17 was obtained in the same manner as in the production of the toner 1 except that the nonpolar hydrocarbon compound dispersion 1 was changed to 5 parts by weight in the attaching step 2. The particle size was 5.9 μm, the thickness of the intermediate layer between the core-shell layers was 0.05 μm, and the average shell thickness was 0.50 μm.

(Manufacture of toner 18);
In the aggregation step, 170 parts by weight of the resin particle dispersion 5 is used instead of the resin particle dispersion 1, and the inorganic particle dispersion 5 is used instead of the inorganic particle dispersion 1, and the aggregation temperature is 55 ° C. The resin particle dispersion 6 is used instead of the resin particle dispersion 5, and the hydrocarbon compound dispersion 1 is changed to 45 parts by weight, and the resin particle dispersion is used instead of the resin particle dispersion 5 in the attaching step 2. A toner 18 was obtained in the same manner as in the production of the toner 1 except that 30 parts by weight of the liquid 10 was used and the heating temperature was 59 ° C. The particle diameter was 6.0 μm, the thickness of the intermediate layer between the core-shell layers was 0.5 μm, and the average shell thickness was 0.6 μm.

(Preparation of external toner)
To 100 parts by weight of each of toners 1 to 18, 0.70 part by weight of hydrophobic silica (manufactured by Cabot, TS720) was added and mixed by a sample mill to obtain an externally added toner. The externally added toner is weighed so that the toner concentration is 5% by weight with respect to a ferrite carrier having a volume average particle diameter D50 of 50 μm coated with 1% by weight of polymethyl methacrylate (manufactured by Soken Chemical Co., Ltd .: Mw 80000). The developer was prepared by stirring and mixing for 5 minutes in a ball mill.

(Image output)
8 parts by weight of each toner 1-18 and 100 parts by weight of carrier were mixed to prepare a developer, and the fixing performance and the like were evaluated by the following procedure. The carrier is a resin-coated carrier in which a ferrite core is coated with a mixture of an amino group-containing vinyl polymer and a fluorinated alkyl group-containing vinyl polymer. The adjusted developer was set in a developing device of a color copier DocuCenter Color 400CP manufactured by Fuji Xerox Co., Ltd. with modifications such as removing the fixing device shown in FIG. 1, and an unfixed image was output. The output image was a solid image (so-called solid image) with a size of 40 × 40 mm, and the amount of image toner was adjusted to 0.50 mg / cm ² . As the paper, the product name “J Coated Paper” manufactured by Fuji Xerox Office Supply Co., Ltd. was used. As a condition for outputting, an undefined image was output after applying a stress to the developer by emptying the toner in the developing device for 1 week in a high temperature and high humidity (30 ° C./50%) environment.

(Fixing method)
For fixing, the fixing device taken out from the DocuColor 1250 copier was remodeled so that the roll temperature of the fixing device could be changed, and the fixing roll was replaced with a Teflon (registered trademark) tube. The sheet conveying speed of the fixing device was 160 mm per second. The unfixed images of the respective toners 1 to 7 were fixed by appropriately changing the temperature of the fixing device from 80 ° C. to 180 ° C. by 5 ° C. to obtain a fixed image. The fixing was performed under a normal (20 ° C./50%) environment. The allowable range was 120 ° C. or lower.

(Fixed image evaluation method)
As the minimum fixing temperature of the toners 1 to 18, a temperature at which fixing is started without causing a low temperature offset is used. The evaluation of image omission was performed visually on the obtained fixed image (fixing temperature 110 ° C.). The evaluation criteria were ◯ when no image omission was observed, Δ when slight image omission was observed, and x when significant image omission was observed. The allowable range was up to Δ.

(Document offset evaluation method)
The images of the fixed images formed using the electrophotographic toners 1 to 18 are overlapped and left in a 60 ° C. atmosphere under a load of 80 g / cm ² and peeled off every day to check for document offset. Evaluation was carried out over 10 days with visual confirmation. In addition, about what was able to peel without applying force at all, and what did not have image deterioration even if it applied force to make it peel, evaluation was continuously performed on the said conditions over 10 days. The evaluation was performed based on the cumulative number of days until a slight image deterioration occurred. Eight days or more were considered acceptable.

(Examples 1-9, Comparative Examples 1-9)
Table 1 shows the performance evaluation of the toners of Examples 1 to 9 and Comparative Examples 1 to 9.

  The toners of Examples 1 to 9 all had a minimum fixing temperature of 120 ° C. or lower, no document offset, and good glossiness in a high temperature and high humidity environment.

  In Comparative Examples 1 and 2, when the specific gravity of the inorganic particles to be added is large or the particle diameter is large, even if low temperature fixing can be obtained by controlling the glass transition point of the desired core-shell structure, the document offset property is slightly bad. The gloss is good.

  In Comparative Example 3, if the desired inorganic particles are not added, low-temperature fixing can be obtained by controlling the glass transition point of the desired core-shell structure, but the document offset property is poor. The gloss is good.

  In Comparative Examples 4 to 6, when both the glass transition points of the core resin and the shell resin are too high, the document offset property is good but the low-temperature fixability is bad. On the other hand, if the glass transition temperatures of the core resin and shell resin are both too low, the document offset property cannot be obtained even if the low-temperature fixability is good. Further, if the glass transition point of the core resin is high and the glass transition point of the shell resin is low, both the low-temperature fixing property and the document offset property are poor.

  In Comparative Examples 7 and 8, there is no intermediate layer between the core-shell layers and when the intermediate layer is too thin, the compatibility between the core-shell resins advances, and the core-shell functions cannot be exhibited, and both the low-temperature fixability and document offset property deteriorate. In addition, uneven gloss occurs due to uneven distribution of different types of resins.

  In Comparative Example 9, since the release agent layer between the core-shell layers is too thick, the document offset property is good, but the function of the core part is hardly exhibited and the low-temperature fixability is deteriorated.

  In Comparative Example 10, when the glass transition point of the shell resin is too high, the document offset property is good but the low-temperature fixability is bad.

  The electrostatic image developing toner and electrostatic image developer of the present invention are particularly useful for applications such as electrophotography and electrostatic recording.

1 is a schematic diagram illustrating a configuration example of an image forming apparatus for forming an image forming method of the present invention.

Explanation of symbols

  1Y, 1M, 1C, 1K Image forming unit, 2Y, 2M, 2C, 2K electrostatic latent image carrier, 4Y, 4M, 4C, 4K exposure unit, 5Y, 5M, 5C, 5K developing device, 6Y, 6M, 6C , 6K transfer means, 7Y, 7M, 7C, 7K electrostatic latent image carrier cleaning device, 8Y, 8M, 8C, 8K neutralization device, 9 intermediate transfer body, 12 secondary transfer roller, 13 backup roller, 14 cleaning means, 17A paper feeding cassette, 17B roll recording paper unit, 17a, 17b paper feeding roller, 18R roll recording paper, 18 recording paper, 19 transport roller, 20 registration roller, 47 fixing belt, 100 image forming apparatus, 101 belt fixing apparatus.

Claims (4)

  A toner having a core-shell structure, wherein the core part has a glass transition point of 20 to 40 ° C., the shell part has a glass transition point of 50 to 100 ° C., and the core part has a volume average particle size of 0.1 to 1.0 μm, It has an intermediate layer containing inorganic particles having a specific gravity of 1.0 to 3.0 and a hydrocarbon compound between the core part and the shell part, and the thickness of the intermediate layer is 0.1 to 0.4 μm. An electrostatic charge image developing toner. A method for producing a toner for developing an electrostatic image having a core-shell structure, comprising:
A core resin particle dispersion in which resin particles constituting a core part having a particle size of 1.0 μm or less are dispersed, a colorant dispersion, an inorganic particle dispersion, and a release agent dispersion are mixed, Preparing a dispersion of first aggregated particles containing resin particles, a colorant, inorganic particles, and a release agent;
The dispersion of the first agglomerated particles is mixed with a dispersion of a hydrocarbon compound and a resin particle dispersion for a shell in which resin particles constituting the shell portion are dispersed, and the first agglomerated particles, the hydrocarbon compound, and the shell are mixed. Preparing a dispersion of second agglomerated particles containing resin particles;
And a step of fusing and coalescing the second aggregated particles by heating to a temperature equal to or higher than the glass transition temperature of the shell resin constituting the shell resin particles. Production method. In an electrostatic charge developer containing a carrier and a toner,
The electrostatic image developer, wherein the carrier has a resin coating layer, and the toner is the electrostatic image developing toner according to claim 1. A step of forming an electrostatic latent image on the electrostatic charge image carrier, a step of developing the electrostatic latent image with a developer on the developer carrier to form a toner image, and the toner image on the transfer member. An image forming method comprising: a step of transferring the toner image onto a fixing sheet; and a step of thermally fixing the toner image.
An image forming method using the electrostatic charge image developer according to claim 3 as the developer.

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