JP2007286202A - Electrostatic latent image developing toner, and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide electrostatic latent image developing toner, wherein even when the toner is left in a compacted state by vibration during transportation in a toner cartridge or left and stored for a long period of time, a certain amount of toner can be smoothly supplied without variation from a cartridge when the cartridge is mounted in a working machine, and stable conveyance is performed without clogging in a toner conveyance passage and a decrease in image density due to toner supply failure is suppressed and a residual amount of the toner in the cartridge can be reduced. <P>SOLUTION: The electrostatic latent image developing toner has: a basic fluidity energy quantity of 50 to 150 mJ when measured with a powder rheometer under the conditions of an aeration flow rate of 0 ml/min, a top speed of a rotating blade of 100 mm/sec and an approach angle of the rotating blade of -5°; and a basic fluidity energy quantity of 0.5 to 15 mJ when measured with a powder rheometer under the conditions of an aeration flow rate of 80 ml/min, a top speed of a rotating blade of 100 mm/sec and an approach angle of the rotating blade of -5°. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrostatic latent image developing toner for developing and visualizing an electrostatic latent image in an electrophotographic method, an electrostatic recording method, and the like, and an image forming method.

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

  In an apparatus used for such an image forming method, it is necessary to replenish the toner every time the toner runs out. However, a toner cartridge for replenishing toner to the image forming apparatus uses the toner stored in the image forming apparatus main body. A so-called replenishment type toner cartridge that replenishes the toner receiving container once, and a so-called stationary type that replenishes the developing device gradually until the toner kit is used up after the toner cartridge is mounted on the main body of the image forming apparatus. Broadly divided into toner cartridges.

  If toner remains in such a toner cartridge, not only the remaining toner is wasted, but also when the used toner cartridge is replaced, the remaining toner scatters in or around the apparatus. It was possible to get dirty.

  In order to improve such a problem, Japanese Patent Application Laid-Open No. 08-110691 discloses a metal oxide powder, silica fine powder, wax-containing particles in a toner cartridge (toner kit) and a stirring member mounted in the toner cartridge, or A configuration in which any of the fluorine resin particles is attached has been proposed.

  However, in this proposal, a fine powder similar to an external additive is adhered to the toner cartridge in order to reduce the remaining amount of toner. However, such a fine powder affects the chargeability and powder characteristics of the toner. There is a problem that it is difficult to obtain high image quality. Further, even if the remaining amount in the toner cartridge decreases, there is a possibility that problems may occur in the subsequent transportability and agitation if the fluidity of the toner remains poor.

  On the other hand, in order to improve the fluidity of the toner, Japanese Patent Application Laid-Open No. 2005-173480 proposes to cover the surface of resin fine particles having a number average particle diameter of 30 to 300 nm as an external additive with a continuous layer of silica.

  However, in this proposal, in order to improve the fluidity, even if the external additive coated with silica on the resin fine particle surface is used and the initial fluidity can be ensured by the spacer effect of the external additive, Since the air in the toner is easily removed due to the spacer effect of the external additive and the transportability is deteriorated, the transport path is easily clogged.

  In order to improve toner fluidity, Japanese Patent Application Laid-Open No. 2004-157354 proposes that an additive is added to the toner surface and the fluidity is regulated by a unique fluidity evaluation method.

  In this proposal, although there is no problem in toner transportability and a toner having high fluidity that can form a high image quality with good dot reproducibility is obtained, in view of the measurement method that defines the fluidity, Since the measurement is performed using a conical rotor in advance in a compacted state, there is no problem in toner transportability, but the initial stability of the toner flow rate cannot be obtained. In addition, the fluidity that can reduce the remaining amount of the toner cartridge cannot be obtained.

Japanese Patent Application Laid-Open No. 08-110691 JP 2005-173480 A JP 2004-157354 A

  Therefore, in view of the above-described conventional problems, the present invention provides a certain amount of toner from a cartridge when it is mounted on an actual machine even when it is placed in a compacted state due to vibration during toner cartridge transportation or when it is stored for a long period of time. Can be supplied smoothly with no fluctuation, can be stably conveyed without clogging in the toner conveyance path in the actual machine, can suppress a decrease in image density due to poor toner supply, and can reduce the remaining amount of toner in the cartridge. An object is to provide a toner for developing an electrostatic latent image and an image forming method.

The above problem is solved by the following means. That is,
The electrostatic latent image developing toner of the present invention is an electrostatic latent image developing toner having at least toner particles and an external additive,
The basic fluidity energy amount is 50 mJ or more and 150 mJ or less when measured with a powder rheometer under conditions of an air flow rate of 0 ml / min, a tip speed of the rotor blade of 100 mm / sec, and an entrance angle of the rotor blade of -5 °,
In addition, the aeration fluid energy amount is 0.5 mJ or more and 15 mJ or less when measured by a powder rheometer under conditions of an air flow rate of 80 ml / min, a tip speed of the rotor blade of 100 mm / sec, and an entrance angle of the rotor blade of -5 °. It is characterized by.

On the other hand, the image forming method of the present invention comprises:
A charging step for charging the electrostatic latent image carrier;
A latent image forming step of forming an electrostatic latent image on the surface of the charged electrostatic latent image carrier;
A development step of developing the electrostatic latent image with a developer containing the electrostatic latent image developing toner of the present invention to form a toner image on the electrostatic latent image carrier;
A transfer step of transferring the toner image onto a recording medium to form an unfixed transfer image;
A fixing step of fixing the unfixed transfer image transferred onto the recording medium;
It is characterized by having.

  According to the present invention, even when the toner cartridge is placed in a compacted state due to vibration during transportation or in the case of long-term stationary storage, a constant amount of toner is smoothly supplied from the cartridge when mounted on the actual machine, without variation. An electrostatic latent image developing toner that can be stably conveyed without clogging in the toner conveyance path in the actual machine, can suppress a decrease in image density due to a poor toner supply, and can reduce the remaining amount of toner in the cartridge; And an image forming method.

  Hereinafter, the present invention will be described in detail.

<Toner for electrostatic latent image development>
The toner for developing an electrostatic latent image (hereinafter simply referred to as toner) of the present invention has toner particles and an external additive, and has an air flow rate of 0 ml / min, a tip speed of a rotating blade of 100 mm / sec, and rotation. The basic fluidity energy when measured with a powder rheometer at a blade entry angle of -5 ° is 50 mJ or more and 150 mJ or less, the aeration flow rate is 80 ml / min, the tip speed of the rotor blade is 100 mm / sec, It is characterized in that the amount of aeration fluidity energy when measured with a powder rheometer under the condition of an entrance angle of -5 ° is 0.5 mJ or more and 15 mJ or less.

  Conventionally, in order to improve the powder fluidity of the toner, it is a general method to add a fluidizing agent. Adhesive force, which improves fluidity by lowering the adhesive force. However, the fluidity after fluidization is good only by reducing the adhesive force, but the variation in toner behavior at the moment of fluidization becomes large. Especially when left for a long time, the bulk density of the toner layer increases and the toner is more constricted. For example, when the toner is discharged from a toner cartridge, the toner flow rate changes greatly, making it difficult to supply stably. It becomes.

  Therefore, as a result of investigating the relationship between the instantaneous behavior of toner flow (short-time behavior when toner is discharged from the cartridge) and fluidity, the instantaneous behavior of toner flow correlates with the basic fluidity energy amount. As a result, the present invention has been completed.

  In other words, in order to stabilize the behavior at the moment of flowing even when the adhesive force is weak and the bulk density is high, the basic fluidity energy must be 150 mJ or less and 50 mJ or more. In addition, new regulators were needed. As a result of earnest examination of the control factors, it was found that the rotation / lubricating action between the toner particles was effective, and satisfied by providing the rotation / lubricating action in addition to the adhesion control between the toner particles. If the basic fluidity energy amount is 150 mJ or more, it is difficult to stably supply, and if it is 50 mJ or less, it will flow out immediately.

  On the other hand, it has been found that the amount of aeration fluidity energy at an aeration flow rate of 80 ml / min has a correlation with the clogging of the piping path, and the clogging of the path tends to occur at 15 mJ or more, and a stable toner flow rate cannot be maintained at 0.5 mJ or less. There is a correlation with the air flow rate of 80 cc / min because the air flow rate at which the toner exhibits a substantially maximum fluidity, and there is little change in energy even when the air flow rate is higher than that. It is done.

  Here, the amount of fluidity energy will be described. The fluidity energy amount is the fluidity energy amount obtained by fluidity measurement with a powder rheometer.

  When measuring the fluidity of particles, it is more influenced by many factors than when measuring the fluidity of liquids, solids, or gases. It is difficult to specify the exact fluidity of the particles. In addition, even if a factor to be measured (for example, particle size) is determined to specify fluidity, the factor actually has little effect on fluidity or only in combination with other factors. The significance of measuring the factor may arise, and even determining the measurement factor is difficult.

  Furthermore, the fluidity of the powder varies significantly depending on external environmental factors. For example, in the case of a liquid, even if the measurement environment changes, the fluctuation range of the fluidity is not so large, but the fluidity of the particles is greatly influenced by external environmental factors such as humidity and the state of the flowing gas. fluctuate. It is not clear which measurement factors are affected by these external environmental factors, so even if measured under strict measurement conditions, the reproducibility of the measured values obtained is actually poor. is there.

  The fluidity when the toner is filled in the toner tank is based on the angle of repose and the bulk density, but these physical properties are indirect to the fluidity of the toner, and the flow of the toner It was difficult to quantify and manage sex.

  However, since the powder rheometer can measure the amount of fluid energy applied from the toner to the rotating blades of the measuring machine, the powder rheometer can be obtained as a sum of the factors attributable to fluidity. Therefore, in the powder rheometer, as in the past, for the toner obtained by adjusting the physical property value and particle size distribution of the surface, determine the items to be measured and find the optimum physical property value for each item and measure it. The flowability can be measured directly.

  As a result, it is possible to determine whether it is suitable as a toner used for developing an electrostatic image only by confirming whether it falls within the above numerical range with a powder rheometer. Such toner production management is a method that is extremely suitable for practical use as compared to the conventional method of managing by indirect values with respect to keeping the toner fluidity constant. Moreover, it is easy to make measurement conditions constant, and the reproducibility of measured values is high.

  That is, the method for specifying the fluidity by the value obtained by the powder rheometer is simple, accurate and highly reliable as compared with the conventional method.

Next, a method for measuring fluidity using a powder rheometer will be described.
The powder rheometer is a fluidity measuring device that directly measures fluidity by simultaneously measuring rotational torque and vertical load obtained by rotating a rotating blade spirally in packed particles. By measuring both the rotational torque and the vertical load, the fluidity including the characteristics of the powder itself and the influence of the external environment can be detected with high sensitivity. In addition, since the measurement is performed with the particle filling state kept constant, data with good reproducibility can be obtained.

  Measurement is performed using FT4 manufactured by freeman technology as a powder rheometer. In order to eliminate the influence of temperature and humidity before the measurement, toner that has been left at a temperature of 22 ° C. and a humidity of 50% RH for 8 hours or more is used.

  First, a toner container is filled with an amount of toner exceeding a height of 89 mm in a split container having an inner diameter of 50 mm (a cylinder having a height of 51 mm placed on a 160 mL container having a height of 89 mm so that it can be separated vertically).

  After the toner is filled, the sample is homogenized by gently stirring the filled toner. This operation will be called conditioning in the following.

  In conditioning, gently stir the rotor blades in a rotating direction that does not receive any resistance from the toner so that it does not overstress in the filled state, removing most of the excess air and partial stress and removing the sample Make it homogeneous. Specific conditioning conditions are agitation at a tip angle of 60 mm / sec with an approach angle of 5 °.

  At this time, the propeller-type rotor blades move downward simultaneously with the rotation, so that the tip draws a spiral, and the angle of the spiral path drawn by the propeller tip at this time is called the entry angle.

  After repeating the conditioning operation four times, the container upper end of the split container is gently moved, and the toner inside the vessel is scraped off at a height of 89 mm to obtain a toner filling the 160 mL container. The conditioning operation is performed because it is important to always obtain a powder having a constant volume in order to obtain the fluid energy amount stably.

  The toner thus obtained is transferred to a 200 mL container having an inner diameter of 50 mm and a height of 140 mm. After the toner was transferred to the 200 mL container, the above operation was further performed three times, and then the tip speed of the rotary blade was 100 mm / mm while moving in the container from a height of 100 mm to 10 mm from the bottom surface at an entrance angle of -5 °. Measure the rotational torque and vertical load when rotating in sec. The direction of rotation of the propeller at this time is the reverse direction to the conditioning (clockwise as viewed from above).

The relationship between the rotational torque or the vertical load with respect to the height H from the bottom surface is shown in FIGS. FIG. 2 shows the energy gradient (mJ / mm) with respect to the height H obtained from the rotational torque and the vertical load. The area obtained by integrating the energy gradient in FIG. 2 (shaded area in FIG. 2) is the fluid energy amount (mJ). The flowable energy amount is obtained by integrating the section from 10 mm to 100 mm in height from the bottom.
Moreover, in order to reduce the influence by an error, let the average value obtained by performing this conditioning and energy measurement operation cycle 5 times be a fluid energy amount (mJ).

  As the rotor blade, a blade having a diameter of 48 mm and having a two-blade propeller type shown in FIG. 3 manufactured by freeman technology is used.

  Then, when measuring the rotational torque and vertical load of the rotor blade, the fluid energy amount measured while flowing air from the bottom of the container at a ventilation flow rate of 80 ml / min is the “aeration fluid energy amount”. The amount of fluidity energy measured from the bottom without being vented, that is, with an aeration flow rate of 0 ml / min is the “basic fluidity energy amount”. In the FT4 manufactured by freeman technology, the inflow state of the air flow rate is controlled.

  From the above, the toner of the present invention has a basic fluid energy amount of 50 mJ or more and 150 mJ or less (preferably 70 mJ or more and 130 mJ or less, more preferably 90 mJ or more and 110 mJ or less), and aeration fluidity at an aeration flow rate of 80 ml / min. When the energy amount is 0.5 mJ or more and 15 mJ or less (preferably 0.5 mJ or more and 10 mJ or less, more preferably 0.5 mJ or more and 8 or less); Even in the case of long-term stationary storage, a fixed amount of toner is supplied smoothly from the cartridge when mounted on the actual machine, and can be stably transported without clogging in the toner transport path in the actual machine. Suppress the decrease in image density and reduce the amount of toner remaining in the cartridge. It can become.

  Here, FIG. 4 shows the relationship between the amount of fluid energy in the toner of the present invention and the air flow rate at the time of measurement. For comparison, the same relationship is shown in FIG. 4 for a toner that is generally said to have good fluidity and a toner that is generally said to have poor fluidity. As shown in FIG. 4, the toner of the present invention has a fluidity energy amount (that is, basic fluidity energy amount) and aeration flow rate when the aeration flow rate is 0 ml / min, compared with a toner generally said to have good fluidity. In addition to the low amount of aeration fluidity energy at 80 ml / min, the difference between the basic fluidity energy amount and the aeration fluidity energy amount is small. As a result, the above-described effects can be achieved satisfactorily.

  Expressed as an index indicating that the difference between the basic fluid energy amount and the aeration fluid energy amount is small, the toner of the present invention has a ratio of the aeration fluid energy to the basic fluid energy of 0.0033 to 0.0033. It is preferable that it is 0.3.

Here, the calculation method of the aeration fluidity index as an index is performed as follows. Aeration fluidity index = aeration fluidity energy ÷ basic fluidity energy, this value preferably satisfies the following formula.
Formula: 0.0033 ≦ aeration fluidity index ≦ 0.3

  To adjust the amount of fluidity energy of the toner when measured under the above conditions to be within the above range, there is a method of adjusting the shape of the toner particles, the amount of wax, the particle size distribution, the type of additive and the amount added. It is also possible to use a combination of these methods.

  The toner of the present invention includes toner particles and an external additive. The toner particles include at least a binder resin, a colorant, and a release agent. Hereinafter, each composition and physical properties will be described.

[Binder resin]
As the binder resin contained in the toner particles, a known resin that can be used for the toner particles can be appropriately selected. Specifically, for example, styrenes such as styrene and chlorostyrene, monoolefins such as ethylene, propylene, butylene and isobutylene, vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate and vinyl butyrate, acrylic acid Esters of α-methylene aliphatic monocarboxylic acids such as methyl, ethyl acrylate, butyl acrylate, octyl acrylate, dodecyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate , Homopolymers and copolymers of vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl butyl ether, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, vinyl isopropenyl ketone, etc. Examples of typical binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, and styrene. Mention may be made of maleic anhydride copolymers, polyethylene, polypropylene. Further examples include polyester, polyurethane, epoxy resin, silicone resin, polyamide, and modified rosin.
Among these, styrene- (meth) acrylic acid ester copolymer resins and polyester resins are preferably used.

The molecular weight of the binder resin varies depending on the type of resin, but the weight average molecular weight Mw is preferably 10,000 to 500,000, more preferably 15,000 to 300,000, and 20,000. More preferably, it is -200,000. The number average molecular weight Mn is preferably 2,000 to 30,000, more preferably 2,500 to 20,000, and still more preferably 3,000 to 15,000.
The values of the weight average molecular weight and the number average molecular weight are those measured using gel permeation chromatography (GPC). GPC uses HLC-8120GPC, SC-8020 (manufactured by Tosoh Corporation), and column uses two TSKgel and SuperHM-H (manufactured by Tosoh Corporation, 6.0 mm ID × 15 cm). THF (tetrahydrofuran) is used. As experimental conditions, the sample concentration is 0.5 mass%, the flow rate is 0.6 ml / min, the sample injection amount is 10 μl, the measurement temperature is 40 ° C., and an IR detector is used.

  The glass transition temperature of the binder resin is preferably 40 ° C. to 80 ° C., and preferably 45 ° C. to 75 ° C. from the viewpoints of preventing deterioration of fluidity in a high temperature environment and achieving low temperature fixability. More preferred.

  The glass transition point (Tg) refers to a value obtained by measurement under a temperature rising rate of 10 ° C./min using a differential scanning calorimeter (manufactured by Shimadzu Corporation: DSC-50). The glass transition point is the temperature at the intersection of the extension line of the base line and the rising line in the endothermic part.

[Colorant]
There is no restriction | limiting in particular as a coloring agent contained in a toner particle, The coloring agent known per se can be mentioned, According to the objective, it can select suitably. Examples of the colorant include carbon black, lamp black, Dupont Oil Red, Orient Oil Red, Rose Bengal, C.I. I. Pigment Red 5, 112, 123, 139, 144, 149, 166, 177, 178, 222, 48: 1, 48: 2, 48: 3, 53: 1, 57: 1, 81: 1, C.I. I. Pigment orange 31, 43, quinoline yellow, chrome yellow, C.I. I. Pigment Yellow 12, 14, 17, 93, 94, 97, 138, 174, 180, 188, ultramarine blue, aniline blue, calcoyl blue, methylene blue chloride, copper phthalocyanine, C.I. I. Pigment Blue 15, 60, 15: 1, 15: 2, 15: 3, C.I. I. Pigment Green 7 and malachite green oxalate, nigrosine dye, and the like can be used, and these can be used alone or in combination. These may have been subjected to flashing dispersion processing in advance.

Moreover, magnetic powder can also be used as a coloring agent. As the magnetic powder, known magnetic materials, for example, metals such as iron, cobalt, nickel and alloys thereof, Fe ₃ O ₄ , γ-Fe ₂ O ₃ , metal oxides such as cobalt-added iron oxide, MnZn ferrite, Various ferrites such as NiZn ferrite, magnetite, hematite and other powders can be used, and the surface thereof is treated with a surface treatment agent such as a silane coupling agent or a titanate coupling agent, inorganic compounds such as silicon compounds and aluminum compounds Those coated with a system material or those coated with a polymer may be used.

  The colorant is preferably added in the range of 3% by mass to 15% by mass and more preferably in the range of 4% by mass to 10% by mass with respect to the toner particles. However, when magnetic powder is used as the colorant, it is preferably added in the range of 12% by mass to 48% by mass and more preferably in the range of 15% by mass to 40% by mass with respect to the toner particles. preferable. By appropriately selecting the type of the colorant, each color toner such as yellow toner, magenta toner, cyan toner, black toner, and green toner can be obtained.

(Release agent)
As the release agent contained in the toner particles, for example, 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 can be used. Derivatives include oxides, polymers with vinyl monomers, graft modified products, and the like. In addition, alcohols, fatty acids, plant waxes, animal waxes, mineral waxes, ester waxes, acid amides, and the like can be used.

  Specifically, hydrocarbon waxes such as low molecular weight polypropylene and low molecular weight polyethylene, microcrystalline wax, silicone resin, rosins, ester wax, rice wax, carnauba wax, Fischer-Tropsch wax, montan wax, candelilla wax, etc. Is mentioned.

  The ratio of the release agent is preferably in the range of 0.1 to 10% by mass, more preferably in the range of 1 to 8% by mass with respect to the toner particles. If the content of the release agent is less than the above lower limit value, the toner release performance may be reduced and offset may occur. On the other hand, if the content exceeds the upper limit value, the toner charging performance is deteriorated or the heat storage performance is increased. May occur, which is not preferable.

[External additive]
The external additive attached to the surface of the toner particles is also for controlling transferability, fluidity, cleaning properties, chargeability controllability, particularly fluidity energy amount. As the external additive, either inorganic fine particles or organic fine particles can be used.

  Examples of inorganic fine particles include silica, aluminum oxide, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, cerium chloride. , Metal oxides such as bengara, chromium oxide, cerium oxide, antimony trioxide, magnesium oxide, magnesium carbonate, zirconium oxide, silicon carbide, silicon nitride, calcium carbonate, barium sulfate, ceramic particles, etc. are used alone or in combination. be able to.

  Examples of the organic fine particles include vinyl polymers such as styrene polymers, (meth) acrylic polymers, and ethylene polymers, and various polymers such as ester, melamine, amide, and allyl phthalate. Fluorine polymers such as vinylidene fluoride, and fine particles made of higher alcohols such as unilin.

  As the external additive, inorganic particles are particularly preferable. Among the inorganic fine particles, at least one selected from silica fine particles, aluminum oxide, titanium oxide, and zinc oxide is preferable, and silica and titanium oxide are preferable. Is more preferable, and silica is more preferable.

  Here, as a method for controlling the amount of fluid energy by an external additive to obtain the above-mentioned prescribed fluid energy amount, the following method is preferably exemplified.

  1) A monodispersed spherical external additive treated with hexamethyldisilazane (HMDS) with respect to the toner particle surface area (for example, a single particle having a true specific gravity of 1.3 to 1.9 and a number average particle diameter of 80 to 300 nm). (Dispersed spherical silica) is externally added at a surface coverage of 20 cov% or more and 80 cov% or less (preferably 30 cov% or more and 70 cov% or less), and a small diameter external additive (for example, titanium oxide) having a number average particle size of 20 nm or less is surfaced. A method of externally adding at a coverage of 50 cov% to 100 cov% (preferably 60 cov% to 90 cov%). This method is particularly suitable when applying toner particles obtained by a wet method (for example, an emulsion polymerization method).

  Here, as a method of external addition, after externally adding a small-diameter external additive to the toner particles under the conditions represented by the following formula (A), a monodispersed spherical external additive is further added under the conditions represented by the following formula (B). It is desirable to add externally.

Formula (A): 1000000 ≦ V × T ≦ 2000000
Formula (B): 1000000 ≦ V × T ≦ 2000000 (where T ≧ 1200)
(In the formula, V: peripheral speed of the stirring blade tip in the mixer (m / second), T: external addition mixing time (second))

  2) A small diameter external additive (for example, titanium oxide, metatitanic acid, silica, etc.) having a number average particle diameter of 20 nm or less with respect to the toner particle surface area is externally added at 80 cov% to 100 cov% (preferably 85 cov% to 95 cov%). Method to attach. In this method, toner particles having a volume average particle diameter of 6 μm to 8 μm and an average circularity ((circle equivalent perimeter) / (perimeter)) by an FPIA2100 (flow type measuring instrument: manufactured by Sysmec Corporation) of 0.970 or more. It is suitable when applying.

  Here, as a method of external addition, it is desirable to externally add a small-diameter external additive to the toner particles under the conditions represented by the above formula (A).

  3) Hydrophobic inorganic fine particles having a number average particle diameter of 20 nm or less with respect to the toner surface area (for example, silane coupling agent, titanate coupling agent, aluminate coupling agent, zirconium coupling agent) Such as titanium oxide, metatitanic acid, silica, etc. that have been hydrophobized with a coupling agent such as silicone oil, polymer coating treatment agent, etc., at 70 cov% to 150 cov% (preferably 90 cov% to 140 cov% or less) And a monodispersed spherical external additive (for example, monodispersed spherical silica having a true specific gravity of 1.3 to 1.9 and a number average particle size of 80 to 300 nm) of 30 cov% to 80 cov% (preferably Is externally added at 40 cov% or more and 70 cov% or less. This technique is suitable when toner particles obtained by a kneading pulverization method are applied.

  Here, as a method of external addition, after adding hydrophobic inorganic fine particles to the toner particles under the conditions represented by the above formula (A), a monodispersed spherical external additive is further added under the conditions represented by the above formula (B). It is desirable to add externally.

The surface coverage with respect to the toner surface area is measured as follows. That is, it is obtained from a cross-sectional SEM photograph of the toner. Specifically, a cross-sectional photograph of one toner particle is taken with a high-resolution electron microscope JEM2010 (manufactured by JEOL Ltd.), and the toner surface length of the toner particle cross section is measured. Further, the length of the portion where the external additive was adhered to the toner surface was measured and calculated by the following formula.
Formula: Surface coverage = external additive adhesion length / toner surface length × 100

The number average particle size is the number of particles divided into particle size ranges (channels) using a particle size distribution obtained by measurement with a laser diffraction particle size distribution measuring apparatus (for example, LA-700, manufactured by Horiba, Ltd.). The cumulative distribution is drawn from the small particle size side, and the particle size that becomes 50% cumulative with respect to all external additives can be determined as the number average particle size D _50p .

  In addition, as in 1) and 2) above, by using two or more types of external additives having different particle diameters, fine irregularities on the surface of the toner particles are controlled, adhesion between the toner particles, and rolling of the toner particles. By adjusting the ease, the amount of fluid energy in the powder rheometer can be suitably controlled. In addition, for example, by preparing the toner by externally adding large-sized inorganic fine particles after the small-sized inorganic fine particles, the large-sized inorganic fine particles coat the toner particle surface, and at the same time, add the small-sized external particles. By coating the surface of the agent, fine irregularities on the outermost surface of the toner can be controlled, and thereby desired fluidity can be secured.

  The amount of the external additive used as a whole is preferably 0.5% by mass to 10% by mass, more preferably 0.6% by mass to 8% by mass, and 0.8% with respect to the toner particles. It is still more preferable that it is mass%-6 mass%.

[Other additives]
In addition to the above composition, known materials used in toners can be appropriately added to the toner of the present invention. Examples thereof include internal additives, charge control agents, inorganic particles, organic particles, lubricants, and abrasives.

Examples of the internal additive include metals such as ferrite, magnetite, reduced iron, cobalt, nickel, and manganese, alloys, and magnetic materials such as compounds containing these metals.
Examples of the charge control agent include quaternary ammonium salt compounds, nigrosine compounds, dyes composed of complexes of aluminum, iron, chromium, and triphenylmethane pigments. In addition, as the charge control agent in the present invention, a material that is difficult to dissolve in water is preferable in terms of controlling ionic strength that affects stability during aggregation and fusion and reducing wastewater contamination.
Examples of the inorganic particles include all particles usually used as an external additive on the toner surface, such as silica, alumina, titania, calcium carbonate, magnesium carbonate, tricalcium phosphate, and cerium oxide. Examples of the organic particles include all particles usually used as external additives on the toner surface, such as vinyl resins, polyester resins, and silicone resins. These inorganic particles and organic particles can be used as fluidity aids, cleaning aids, etc. Examples of lubricants include fatty acid amides such as ethylene bisstearyl amide and oleic acid amide, and stearic acid. Examples include fatty acid metal salts such as zinc and calcium stearate. Examples of the abrasive include the aforementioned silica, alumina, cerium oxide, and the like.

[Production method]
The toner of the present invention can be obtained by attaching or fixing the external additive to the surface of the toner particle by applying a mechanical impact force between the toner particle and the external additive using a sample mill or a Henschel mixer.

  The toner particles can be produced according to a known production method. There is no restriction | limiting in particular as said manufacturing method, According to the objective, it can determine suitably.

  For example, after pre-mixing a binder resin, a colorant, a release agent, and a charge control agent, if desired, melt-kneading in a kneader, pulverizing after cooling, and vibration sieving machine or wind sieving machine as described above Etc., and can be produced using a kneading and pulverizing method. Further, it can be produced by a wet spheronization method, a suspension granulation method, a suspension polymerization method, an emulsion polymerization aggregation method or the like.

[Physical properties]
(Volume average particle diameter of toner particles)
The volume average particle size of the toner particles is preferably 4 μm to 12 μm, more preferably 4.5 μm to 10 μm, and still more preferably 5 μm to 9 μm. When the volume average particle size of the toner particles is less than 4 μm, the fluidity is remarkably lowered, so that the developer layer is not sufficiently formed by the layer regulating member or the like, and the image may be fogged or dirtied. On the other hand, if it exceeds 12 μm, the resolution is lowered and a high-quality image may not be obtained, or the charge amount per developer unit weight is lowered, and the layer formation maintenance property of the developer layer is lowered, Fog and dirt may occur in the image.

As a method for measuring the volume average particle diameter of the toner particles, 0.5 to 50 mg of a measurement sample is added to 2 ml of a 5% by weight aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate, as a dispersant, and this is added to the electrolytic solution. Added in 100-150 ml. The electrolytic solution in which the measurement sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute. Using the Coulter Counter TA-II type, an aperture having an aperture diameter of 100 μm is used. The particle size distribution of particles in the range of 60 μm is measured. The number of particles to be measured is 50,000.
For the particle size range (channel) obtained by dividing the obtained particle size distribution, the volume cumulative distribution is subtracted from the small particle size side, and the particle size that becomes 50% cumulative is _defined as the volume average particle size D _50v .

(Particle size distribution of toner particles)
The preferred particle size distribution of the toner particles is when the proportion of toner particles having a particle size of 4 μm or less is 45% by number or less, more preferably 40% by number or less, and even more preferably 35% by number or less.
Similarly to the determination of the volume average particle diameter D _50v , the particle diameter that is 84% cumulative when the volume cumulative distribution is subtracted from the small particle diameter side is D _84v, and the number cumulative distribution is calculated from the small particle diameter side. It is preferable that D _84v / D _50v is 1.35 or less, where D _{16p is} the particle size that is 16% cumulative when subtracted, and D _50p (number average particle size) is the particle size that is 50%. More preferably, it is 30 or less. It is preferable that D _50p / D _16p is 1.45 or less, more preferably 1.40 or less.

  In order to obtain toner particles having such a particle size distribution, the toner particle size can be adjusted to a desired particle size distribution by using a gravity classifier, a centrifugal classifier, an inertia classifier, or a sieve.

  When the particle size distribution of the toner particles is wider than the above range, the fluid energy amount by the powder rheometer described above tends to be out of the specified range.

The particle size distribution of the toner particles is obtained by subtracting the volume cumulative distribution from the small particle size side with respect to the particle size range (channel) obtained by dividing the particle size distribution obtained by the same method as the measurement of the volume average particle size. When the particle size of 84% is _D84v , the cumulative number distribution is subtracted from the small particle size side, the particle size of 50% is _D50p , and the particle size of 16% is _D16p. the particle size distribution index and the volume average particle diameter D _84v / volume average particle diameter D _50v, refers to a value obtained fine powder side particle size distribution index as the number average particle diameter D _50p / number average particle diameter D _16p.

(Average circularity of toner particles)
The shape of the toner particles is preferably controlled in order to obtain the fluid energy amount according to the present invention. The average circularity of the toner particles is preferably between 0.94 and 0.99. If it falls below the above range, the shape becomes indeterminate, and transferability, durability, fluidity and the like are lowered, which is not preferable. On the other hand, when the above range is exceeded, the ratio of the spherical particles increases and the cleaning property becomes difficult. A more preferable range of the average circularity is 0.95 to 0.98.

  Here, the average circularity is obtained by (circle equivalent perimeter) / (perimeter) [(perimeter of a circle having the same projection area as the particle image) / (perimeter of the particle projection image)] A flow-type particle image analyzer (for example, manufactured by Sysmex Corporation) takes a particle image as a still image by instantly strobe light emission, and forms a very flat flow. FPIA-2100). The number of samplings when obtaining the average circularity is 3500.

  The toner particles having the above average circularity are subjected to heat treatment after pulverization and classification, treatment by mechanical impact force, etc. to control the spheroidization of the toner shape, or by applying a wet production method such as an emulsion aggregation method. Obtainable.

  The toner of the present invention may be used as a so-called one-component developer that is used alone or as a two-component developer that is used in combination with a carrier.

<Image forming method>
The image forming method of the present invention comprises at least a charging step for charging an electrostatic latent image carrier, a latent image forming step for forming an electrostatic latent image on the surface of the charged electrostatic latent image carrier, and development including toner. A development step of developing the electrostatic latent image with an agent to form a toner image on the electrostatic latent image carrier, and a transfer step of transferring the toner image onto a recording medium to form an unfixed transfer image. And a fixing step of fixing the unfixed transferred image transferred onto the recording medium. And the toner of the said invention is applied as a toner.

  In the image forming method of the present invention, known techniques can be appropriately applied to the charging step, latent image forming step (exposure step), developing step, and transfer step. Further, in addition to these steps, a cleaning step for cleaning the electrostatic latent image carrier after the transfer step, a fixing step for fixing the transferred toner image on the recording material, and the like may be performed.

  FIG. 5 is a schematic configuration diagram showing an example of an image forming apparatus applied to the image forming method of the present invention. The image forming apparatus shown in FIG. 5 (hereinafter referred to as the image forming apparatus according to the present embodiment) collects toner remaining after transfer by a cleaning device, supplies the recovered toner to the developing device, and re-uses toner reclaim and replenishment. A trickle development is adopted in which a replenishment developer including a replenishment toner and a replenishment carrier is appropriately supplied to the developing device, and the stored developer is appropriately discharged from the developing device.

  As shown in FIG. 5, the image forming apparatus according to the embodiment of the present invention includes a photosensitive drum 10 that rotates clockwise as indicated by an arrow a, and a photosensitive drum 10 that is positioned above the photosensitive drum 10. And a charging roll 20 that is negatively charged on the surface of the photosensitive drum 10 and an image to be formed with a developer (toner) is written on the surface of the photosensitive drum 10 that is charged by the charging roll 20. An exposure device 30 that forms a latent image, and a developing device that is provided on the downstream side of the exposure device 30 and attaches toner to the latent image formed by the exposure device 30 to form a toner image on the surface of the photosensitive drum 10. 40 and an endless belt-shaped intermediate transfer belt 50 that travels in the direction indicated by the arrow b while being in contact with the photosensitive drum 10 and transfers the toner image formed on the surface of the photosensitive drum 10. The surface of the photosensitive drum 10 after transferring the toner image to the intermediate transfer belt 50 is neutralized, and the surface of the photosensitive drum 10 is cleaned, and the neutralizing device 60 that makes it easy to remove the transfer residual toner remaining on the surface. And a cleaning device 70 for removing the transfer residual toner.

  The charging roll 20, the exposure device 30, the developing device 40, the intermediate transfer belt 50, the charge removal device 60, and the cleaning device 70 are arranged in a clockwise direction on the circumference surrounding the photosensitive drum 10.

  The intermediate transfer belt 50 is tensioned and held from the inside by the stretching rollers 50A and 50B, the backup roller 50C, and the driving roller 50D, and is driven in the direction of the arrow b as the driving roller 50D rotates. At a position opposite to the photosensitive drum 10 inside the intermediate transfer belt 50, primary transfer in which the intermediate transfer belt 50 is positively charged and the toner on the photosensitive drum 10 is attracted to the outer surface of the intermediate transfer belt 50. A roller 51 is provided. On the outer side below the intermediate transfer belt 50, the recording paper P is positively charged and pressed against the intermediate transfer belt 50 to transfer the toner image formed on the intermediate transfer belt 50 onto the recording paper P. A transfer roller 52 is provided to face the backup roller 50C.

  Below the intermediate transfer belt 50, a recording paper supply device 53 that supplies the recording paper P to the secondary transfer roller 52 and a recording paper P on which the toner image is formed on the secondary transfer roller 52 are conveyed, A fixing device 80 for fixing the toner image is provided.

  The recording paper supply device 53 includes a pair of transport rollers 53A and a guide slope 53B that guides the recording paper P transported by the transport rollers 53A toward the secondary transfer roller 52. On the other hand, the fixing device 80 includes a fixing roller 81 that is a pair of heat rollers for fixing the toner image by heating and pressing the recording paper P on which the toner image is transferred by the secondary transfer roller 52, and fixing. A conveyance conveyor 82 that conveys the recording paper P toward the roller 81.

  The recording paper P is conveyed in the direction indicated by the arrow c by the recording paper supply device 53, the secondary transfer roller 52, and the fixing device 80.

  In the vicinity of the intermediate transfer belt 50, an intermediate transfer member cleaning device 54 having a cleaning blade for removing toner remaining on the intermediate transfer belt 50 after the toner image is transferred to the recording paper P by the secondary transfer roller 52 is provided. It has been.

  Hereinafter, the developing device 40 will be described in detail. The developing device 40 is disposed to face the photosensitive drum 10 in the developing region, and contains, for example, a two-component developer composed of a toner charged to a negative (−) polarity and a carrier charged to a positive (+) polarity. A developing container 41 is provided. The developing container 41 includes a developing container main body 41A and a developing container cover 41B that closes the upper end thereof.

  The developing container main body 41A has a developing roll chamber 42A for accommodating the developing roll 42 inside thereof, adjacent to the developing roll chamber 42A, and adjacent to the first stirring chamber 43A and the first stirring chamber 43A. And a stirring chamber 44A. Further, a layer thickness regulating member 45 for regulating the developer layer thickness on the surface of the developing roll 42 when the developing container cover 41B is attached to the developing container main body 41A is provided in the developing roll chamber 42A.

  The first stirring chamber 43A and the second stirring chamber 44A are partitioned by a partition wall 41C. Although not shown, the first stirring chamber 43A and the second stirring chamber 44A are arranged in the longitudinal direction of the partition wall 41C (developing device). (Longitudinal direction) Communication portions are provided at both end portions to communicate with each other, and the first stirring chamber 43A and the second stirring chamber 44A constitute a circulation stirring chamber (43A + 44A).

  In the developing roll chamber 42A, the developing roll 42 is disposed so as to face the photosensitive drum 10. Although not shown, the developing roll 42 is provided with a sleeve outside a magnetic roll (fixed magnet) having magnetism. The developer in the first stirring chamber 43A is adsorbed on the surface of the developing roll 42 by the magnetic force of the magnetic roll and is transported to the developing area. Further, the developing roller 42 has a roll shaft supported rotatably on the developing container main body 41A. Here, the developing roll 42 and the photosensitive drum 10 rotate in opposite directions, and the developer adsorbed on the surface of the developing roll 42 in the opposite portion is from the same direction as the traveling direction of the photosensitive drum 10. It is conveyed to the development area.

  A bias power supply (not shown) is connected to the sleeve of the developing roll 42 so that a predetermined developing bias is applied (in this embodiment, an alternating electric field is applied to the developing region. , Applying a bias in which the AC component (AC) is superimposed on the DC component (DC)).

  In the first stirring chamber 43A and the second stirring chamber 44A, a first stirring member 43 (stirring / conveying member) and a second stirring member 44 (stirring / conveying member) that convey the developer while stirring are disposed. The first stirring member 43 includes a first rotating shaft that extends in the axial direction of the developing roll 42, and an agitating / conveying blade (protrusion) that is helically fixed to the outer periphery of the rotating shaft. Similarly, the second agitating member 44 includes a second rotating shaft and an agitating / conveying blade (protrusion). The stirring member is rotatably supported by the developing container main body 41A. The first stirring member 43 and the second stirring member 44 are arranged such that the developer in the first stirring chamber 43A and the second stirring chamber 44A is conveyed in the opposite directions by rotation thereof. .

  One end of a replenishment conveyance path 46 for appropriately supplying a replenishment developer including a replenishment toner and a replenishment carrier to the second agitation chamber 44A is connected to one longitudinal end of the second agitation chamber 44A. A developer hopper 47 containing a replenishment developer is connected to the other end of the replenishment conveyance path 46. Also, one end of the second stirring chamber 44A in the longitudinal direction is connected to one end of a discharge conveyance path 48 for appropriately discharging the stored developer, and the other end of the discharge conveyance path 48 is not shown. Is connected to the developer storage for collecting the discharged developer.

  As described above, the developing device 40 appropriately supplies the replenishment developer from the developer hopper 47 via the replenishment conveyance path 46 to the developing device 40 (second stirring chamber 44A), and the old developer is discharged from the discharge conveyance path 48. A so-called trickle developing system that discharges properly (in order to prevent a decrease in developer charging performance and extend the interval of developer replacement, a replenishment developer (trickle developer) is gradually replenished in the developing device. Therefore, it is a developing system in which development is performed while discharging the deteriorated developer that is excessive (including many deteriorated carriers).

  Next, the cleaning device 70 will be described in detail. The cleaning device 70 includes a housing 71 and a cleaning blade 72 disposed so as to protrude from the housing 71. The cleaning blade 72 is a plate-like member extending in the extending direction of the rotation shaft of the photosensitive drum 10, and is downstream in the rotation direction (arrow a direction) from the transfer position by the primary transfer roller 51 in the photosensitive drum 10. In addition, a tip portion (hereinafter referred to as an edge portion) is provided in pressure contact with the downstream side in the rotation direction from the position where the charge is removed by the charge removal device 60.

  When the photosensitive drum 10 rotates in a predetermined direction (arrow a direction), the cleaning blade 72 is not transferred to the recording paper P by the primary transfer roller 51 and is not transferred on the photosensitive drum 10. Foreign matter such as toner or paper dust of the recording paper P is dammed and removed from the photosensitive drum 10.

  Further, a transport member 73 is disposed at the bottom of the housing 71, and toner particles (developer) removed by the cleaning blade 72 on the downstream side of the transport direction of the transport member 73 in the housing 71 are developed by the developing device 40. One end of a supply conveyance path 74 for supplying to is connected. The other end of the supply conveyance path 74 is connected so as to join the supply conveyance path 46.

  As described above, the cleaning device 70 conveys untransferred residual toner particles to the developing device 40 (second stirring chamber 44A) through the supply conveyance path 74 in accordance with the rotation of the conveyance member 73 provided at the bottom of the housing 71. Toner reclaim is employed in which the developer (toner) contained therein is stirred and conveyed for reuse.

  By applying the toner of the present invention to the image forming apparatus having such a configuration, the toner can be used even when the developer hopper (toner cartridge) is placed in a compacted state by vibration during transportation of the developer hopper (toner cartridge) or in the case of long-term stationary storage. A constant amount of toner can be transported smoothly and consistently in the toner transport path for reclaiming and the toner transport path from the developer hopper (toner cartridge), and can be transported stably without clogging. It is possible to suppress a decrease in image density due to a defect. In addition, the remaining amount of toner in the developer hopper (toner cartridge) can be reduced.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples. In the text, “parts” means “parts by weight”.

<Measuring method of various characteristics>
First, methods for measuring physical properties of developers and the like used in Examples and Comparative Examples will be described.

-Average circularity-
The measurement was performed using a flow particle image analyzer (trade name FPIA2100) manufactured by Hosokawa Micron Corporation.

-Volume average particle size, particle size distribution-
The particle size was measured using a Coulter counter TA-II type (manufactured by Beckman-Coulter) as the measuring device and ISOTON-II (manufactured by Beckman-Coulter) as the electrolyte.

  As a measurement method, 0.5 to 50 mg of a measurement sample was added to 2 ml of a 5% by weight aqueous solution of a surfactant, preferably sodium alkylbenzenesulfonate as a dispersant, and this was added to 100 to 150 ml of the electrolytic solution. The electrolytic solution in which the measurement sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 minute. Using the Coulter Counter TA-II type, an aperture having an aperture diameter of 100 μm is used. The particle size distribution of particles in the range of 60 μm was measured. The number of particles to be measured was 50,000.

For the divided particle size range (channel), the measured particle size distribution is drawn from the smaller diameter side for each volume and number, and the cumulative volume particle size that is 16% cumulative in volume is D _16v , and cumulative 16 in number. % Cumulative particle diameter is defined as D _16p . Similarly, the particle size that is 50% cumulative in volume is defined as the volume average particle size D _50v , and the particle size that is cumulative 50% in number is defined as the number average particle size D _50p . Similarly, a cumulative volume particle size that is 84% cumulative is defined as D _84v , and a cumulative number particle size that is 84% cumulative is defined as D _84p . The volume average particle diameter is the D _50v .
For the toner particles, the proportion of particles having a particle size of 4 μm or less was determined from the particle size distribution obtained above.

-Measurement of molecular weight distribution-
The molecular weight distribution of the resin of the toner was performed under the following conditions.
Tosoh Corporation HLC-8120GPC, SC-8020 apparatus was used, TSK gei, SuperHM-H (6.0 mmID × 15 cm) was used as a column, and THF (tetrahydrofuran) was used as an eluent. As measurement conditions, the sample concentration was 0.5% by mass, the flow rate was 0.6 ml / min, the sample injection amount was 10 μl, the measurement temperature was 40 ° C., and the measurement was performed using an IR detector.
The calibration curve is “polystylen standard sample TSK standard” manufactured by Tosoh Corporation: A-500, F-1, F-10, F-80, F-380, A-2500, F-4, F-40, F-128. , F-700 was prepared from 10 samples. The data collection interval in the sample analysis was 300 ms.

-Measurement of glass transition temperature-
The glass transition point (Tg) of the binder resin was determined by measurement using a differential scanning calorimeter (manufactured by Shimadzu Corporation: DSC-50) under a temperature increase rate of 10 ° C./min. In addition, the glass transition point was made into the temperature of the intersection of the extended line of the base line in a heat absorption part, and a rising line.

[Example 1]
(Production of toner particles)
-Adjustment of resin fine particle dispersion-
-Styrene: 370 parts-n-butyl acrylate: 30 parts-Acrylic acid: 8 parts Dodecanethiol: 24 parts-Carbon tetrabromide: 4 parts Nonipol 400 (manufactured by Sanyo Kasei Co., Ltd.) 6 parts and anionic surfactant (Neogen SC: Daiichi Kogyo Seiyaku Co., Ltd.) 10 g were emulsion-polymerized in a flask dissolved in ion-exchanged water 550 parts for 10 minutes While slowly mixing, 50 parts of ion-exchanged water in which 4 g of ammonium persulfate was dissolved was added thereto. After carrying out nitrogen substitution, the inside of the flask was stirred and heated in an oil bath until the contents reached 70 ° C., and emulsion polymerization was continued for 5 hours. As a result, a resin fine particle dispersion in which resin particles of 150 nm, Tg = 58 ° C., and weight average molecular weight Mw = 12000 were dispersed was prepared.

-Preparation of colorant dispersion-
Carbon black (Mogal L: Cabot): 60 parts Nonionic surfactant (Nonipol 400: Sanyo Chemical Co., Ltd.): 6 parts Ion exchange water: 240 parts The above ingredients are mixed and dissolved. A colorant dispersant in which colorant (carbon black) particles having an average particle size of 250 nm are dispersed by stirring with a homogenizer (Ultra Turrax T50: manufactured by IKA) for 10 minutes and then dispersing with an optimizer. Was prepared.

-Preparation of release agent dispersion-
Paraffin wax (HNP0190: Nippon Seiwa Co., Ltd., melting point 85 ° C.): 100 parts Cationic surfactant (Sanisol B50: Kao Corporation): 5 parts Ion-exchanged water: 240 parts Was dispersed in a round stainless steel flask using a homogenizer (Ultra Turrax T50: manufactured by IKA) for 10 minutes, and then dispersed with a pressure discharge type homogenizer, and release agent particles having an average particle diameter of 520 nm. A mold release agent dispersion liquid was prepared.

-Production of toner particles-
-Resin fine particle dispersion: 234 parts-Colorant dispersion: 30 parts-Release agent dispersion: 40 parts-Polyaluminum hydroxide (Pho2S manufactured by Asada Chemical Co., Ltd.): 0.5 parts-Ion exchange water : 600 parts The above components were mixed and dispersed in a round stainless steel flask using a homogenizer (Ultra Turrax T50: manufactured by IKA), and then stirred at 50 ° C. in an oil bath for heating. Until heated. After maintaining at 50 ° C. for 30 minutes, it was confirmed that aggregated particles having a D50 of 4.7 μm were formed. Further, the temperature of the heating oil bath was raised and maintained at 56 ° C. for 1 hour, and D50 was 6.2 μm. Thereafter, 26 parts by weight of the resin fine particle dispersion was added to the dispersion containing the aggregate particles, and then the temperature of the heating oil bath was raised to 50 ° C. and held for 30 minutes. After adding 1N sodium hydroxide to the dispersion containing the aggregate particles and adjusting the pH of the system to 7.0, the stainless steel flask is sealed, and the stirring is continued using a magnetic seal up to 80 ° C. Heated and held for 4 hours. After cooling, the toner particles were filtered off, washed four times with ion exchange water, and then lyophilized to obtain toner particles.

(Preparation of toner (external toner))
To 100 parts of toner particles, 0.9 part of metatitanic acid (number average particle diameter 10 nm) is added and blended for 15 minutes at a stirring blade tip peripheral speed of 55 m / s using a 20 L Henschel mixer to obtain a toner particle surface area. On the other hand, 50 cov% was externally added. Thereafter, 2.8 parts of monodispersed spherical sol-gel silica (number average particle diameter 150 nm, HMDS treatment) is added to 100 parts of toner particles, and blended for 20 minutes at a stirring blade tip peripheral speed of 10 m / s using a 20 L Henschel mixer. And 25 cov% of the toner particle surface area was externally added. Then, coarse particles were removed using a sieve having an opening of 45 μm to prepare an externally added toner.

  The obtained externally added toner had a basic fluid energy amount of 110 mJ and a fluid energy amount of 10 mJ at an air flow rate of 80 ml / min.

(Evaluation)
When the obtained external additive toner was used and left in a high-temperature and high-humidity (45 ° C. and 90%) environment for 7 days, a cartridge discharge / remaining amount test was conducted. The amount of toner remaining in the empty detection was 0.5 g. Further, no clogging of the conveyance path occurred.

-Cartridge ejection / remaining capacity test-
The cartridge discharge / remaining amount test was performed as follows. 300 g of toner is put into the cartridge. The cartridge is driven while the toner discharge port is kept open, the amount of toner discharged from the discharge port is measured every minute, and the operation is continued until the toner is not discharged. The amount of toner discharged in the initial 180 seconds was measured, and the variation was evaluated. Further, the toner was taken out from the toner cartridge after being discharged, and the remaining amount was evaluated.
Further, the standard of the transport path is as follows.
○: Not generated △: Slightly generated ×: Generated

[Example 2]
(Production of toner particles)
After adjusting the pH to 7.0, toner particles were obtained in the same manner as in Example 1 except that the stainless steel flask was heated to 95 ° C. and held for 6 hours.

(Preparation of toner (external toner))
To 100 parts of toner particles, 1.3 parts of metatitanic acid (number average particle diameter 10 nm) is added and blended for 15 minutes at a stirring blade tip peripheral speed of 55 m / s using a 20 L Henschel mixer to obtain a toner particle surface area. On the other hand, 85 cov% was externally added. Then, coarse particles were removed using a sieve having an opening of 45 μm to prepare an externally added toner.

  The obtained externally added toner had a basic fluidity energy amount of 140 mJ, and an aeration fluidity energy amount of 0.8 mJ at an aeration flow rate of 80 ml / min.

(Evaluation)
When the obtained external additive toner was used and left in a high-temperature and high-humidity (45 ° C. and 90%) environment for 7 days, a cartridge discharge / remaining amount test was conducted. The amount of toner remaining after empty detection was 1.5 g. Further, no clogging of the conveyance path occurred.

[Example 3]
(Production of toner particles)
Binder resin: Styrene / n-butyl acrylate (= 72/18) resin (Mw = 140,000, Tg = 59 ° C.) 46.5% by mass
-Magnetite (trade name: MTH009F, manufactured by Toda Kogyo Co., Ltd.) 50% by mass
・ 2.5% by mass of polypropylene wax
(Product name: Viscol 550-P, manufactured by Sanyo Chemical Industries)
・ Negative charge control agent (Fe-containing azo dye) 1.0% by mass
(Product name: T-77, manufactured by Hodogaya Chemical Co., Ltd.)

  The above composition was powder-mixed with a Henschel mixer, and this was heat-kneaded with an extruder having a set temperature of 150 ° C. to obtain a kneaded product. After cooling, coarsely and finely pulverized to obtain a pulverized product. Furthermore, this pulverized product was classified and spheroidized using a Nobilta manufactured by Hosokawa Micron. Toner particles were obtained.

(Preparation of toner (external toner))
To 100 parts of toner particles, 1.7 parts of silica fine particles (number average particle diameter of 15 nm, hydrophobization treatment: HMDS (hexamethyldisilazane) treatment) are added, and using a 20 L Henschel mixer, the tip speed of the stirring blade is 60 m / sec. The blend was performed for 15 minutes at s, and 100 cov% was externally added to the surface area of the toner particles. Thereafter, 5.0 parts of monodispersed spherical sol-gel silica (number average particle diameter 140 nm, HMDS treatment) is added to 100 parts of toner particles, and blended for 20 minutes at a stirring blade tip peripheral speed of 10 m / s using a 20 L Henschel mixer. And 45 cov% was externally added to the surface area of the toner particles. Then, coarse particles were removed using a sieve having an opening of 45 μm to prepare an externally added toner.

  The obtained externally added toner had a basic fluidity energy amount of 140 mJ and an aeration fluidity energy amount of 15 mJ at an aeration flow rate of 80 ml / min.

(Evaluation)
When the obtained external additive toner was used and left in a high-temperature and high-humidity (45 ° C. and 90%) environment for 7 days, a cartridge discharge / remaining amount test was conducted. The amount of toner remaining after empty detection was 9 g. Further, no clogging of the conveyance path occurred.

[Example 4]
(Preparation of toner (external toner))
To 100 parts of the toner particles obtained in Example 2, 1.3 parts of titanium oxide fine particles (number average particle diameter 20 nm) were added, and blended for 15 minutes at a stirring blade tip peripheral speed of 55 m / s using a 20 L Henschel mixer. And 30 cov% of the toner particle surface area was externally added. Thereafter, 1.5 parts of monodispersed spherical sol-gel silica (number average particle diameter 140 nm, HMDS treatment) is added to 100 parts of toner particles, and blended for 20 minutes at a stirring blade tip peripheral speed of 10 m / s using a 20 L Henschel mixer. And 30 cov% of the toner particle surface area was externally added. Then, coarse particles were removed using a sieve having an opening of 45 μm to prepare an externally added toner.

  The obtained external additive toner had a basic fluidity energy amount of 70 mJ, and a fluidity energy amount of 2 mJ at an air flow rate of 80 ml / min.

(Evaluation)
Using the obtained externally added toner and leaving it in a high temperature and high humidity (45 ° C., 90%) environment for 7 days, a cartridge dischargeability / remaining amount test was conducted. As a result, the toner flow rate variation in the initial 180 seconds was ± 2 g. Yes, the toner remaining amount in the empty detection was 1.5 g. Also, no clogging of the conveyance path occurred.

[Comparative Example 1]
(Production of toner particles)
Toner particles were obtained in the same manner as in Example 1.

(Preparation of toner (external toner))
To 100 parts of toner particles, 0.15 part of metatitanic acid (number average particle diameter of 10 nm) and 1.1 part of monodispersed spherical sol-gel silica (number average particle diameter of 150 nm, HMDS treatment) are simultaneously added, and a 20 L Henschel mixer is used. Blending was performed at a stirring blade tip peripheral speed of 30 m / s for 10 minutes, metatitanic acid was externally added to the toner particle surface area by 10 cov%, and monodispersed spherical sol-gel silica was externally added to the toner particle surface area by 10 cov%. Then, coarse particles were removed using a sieve having an opening of 45 μm to prepare an externally added toner.

  The obtained externally added toner had a basic fluidity energy amount of 300 mJ and an aeration fluidity energy amount of 25 mJ at an aeration flow rate of 80 ml / min.

(Evaluation)
When the obtained toner was used and left in a high-temperature, high-humidity (45 ° C., 90%) environment for 7 days, a cartridge discharge / remaining amount test was conducted. The amount of toner remaining in the empty detection was 13 g. In addition, a transport path, i.e., occurred.

[Comparative Example 2]
(Production of toner particles)
Toner particles were obtained in the same manner as in Example 2.

(Preparation of toner (external toner))
To 100 parts of toner particles, 3.0 parts of silica (number average particle diameter 50 nm) is added, blended for 10 minutes at a stirring blade tip peripheral speed of 30 m / s using a 20 L Henschel mixer, and silica is added to the surface area of the toner particles. On the other hand, 50 cov% was externally added. Then, coarse particles were removed using a sieve having an opening of 45 μm to prepare an externally added toner.

  The obtained externally added toner had a basic fluidity energy amount of 200 mJ and an aeration fluidity energy amount of 18 mJ at an aeration flow rate of 80 ml / min.

(Evaluation)
When the obtained external additive toner was used and left in a high-temperature, high-humidity (45 ° C., 90%) environment for 7 days, a cartridge dischargeability / remaining amount test was conducted. The amount of toner remaining in empty detection was 7 g. Piping clogging did not occur, but it was a little bit.

[Comparative Example 3]
(Production of toner particles)
Toner particles were obtained in the same manner as in Example 1.

(Preparation of toner (external toner))
To 100 parts of toner particles, 0.9 part of silica (number average particle diameter of 15 nm) and 0.4 part of titanium oxide (number average particle diameter of 20 nm) are simultaneously added, and mixed at 1200 rpm for 2 minutes using a Q mixer. Blending was performed, and silica was added in an amount of 50 cov to the toner particle surface area and titanium was added in an amount of 10 cov to the toner particle surface area. Then, coarse particles were removed using a sieve having an opening of 45 μm, and an externally added toner was produced.

  The obtained externally added toner had a basic fluidity energy amount of 300 mJ and an aeration fluidity energy amount of 40 mJ at an aeration flow rate of 80 ml / min.

(Evaluation)
When the obtained toner was used and left in a high-temperature, high-humidity (45 ° C., 90%) environment for 7 days, a cartridge dischargeability / remaining amount test was conducted. And the remaining amount of toner in the empty detection was 5 g. Moreover, although the conveyance path was not clogged, it was somewhat insignificant.

[Comparative Example 4]
(Production of toner particles)
Toner particles were obtained in the same manner as in Example 2.

(Preparation of toner (external toner))
To 100 parts of toner particles, 3 parts of monodispersed spherical sol-gel silica (number average particle diameter 140 nm) and 10 parts of titanium oxide (number average particle diameter 20 nm) are simultaneously added, and a stirring blade tip peripheral speed is 15 m / s using a 20 L Henschel mixer. Blending was performed for 15 minutes, and monodispersed spherical silica was externally added to the toner particle surface area by 30 cov% and titanium oxide was 250 cov%. Then, coarse powder was removed using a sieve having an opening of 45 μm to prepare an externally added toner.

  The obtained external additive toner had a basic fluidity energy amount of 40 mJ, and an aeration fluidity energy amount of 0.2 mJ at an aeration flow rate of 80 ml / min.

(Evaluation)
Using the obtained externally added toner and leaving it in a high temperature and high humidity (45 ° C., 90%) environment for 7 days, a cartridge dischargeability / remaining amount test was conducted. there were. The remaining amount of toner in the empty detection was 0.7 g. Further, no conveyance path, i.e., has occurred.

[Comparative Example 5]
(Production of toner particles)
Toner particles were obtained in the same manner as in Example 1.

(Preparation of toner (external toner))
4 parts of monodispersed spherical sol-gel silica (number average particle diameter 150 nm) is added to 100 parts of toner particles, and blended for 20 minutes at a stirring blade tip peripheral speed of 20 m / s using a 20 L Henschel mixer. 35 cov% was externally added. Then, coarse particles were removed using a sieve having an opening of 45 μm to prepare an externally added toner.

  The resulting externally added toner had a basic fluidity energy amount of 160 mJ, and an aeration fluidity energy amount of 12 mJ at an aeration flow rate of 80 ml / min.

(Evaluation)
The obtained external additive toner was left in a high-temperature and high-humidity (45 ° C. and 90%) environment for 7 days, and then the cartridge dischargeability / remaining amount test was conducted. The amount of toner remaining in the empty detection was 10 g. Moreover, although there was no clogging of the conveyance path, it was a little bit.

  Tables 1 and 2 show the properties and evaluations of the toners obtained in the above Examples and Comparative Examples.

It is a figure for demonstrating the measuring method of the fluid energy amount in a powder rheometer. It is a figure which shows the relationship between the vertical load and energy gradient which were obtained with the powder rheometer. It is a figure for demonstrating the shape of the rotary blade used with a powder rheometer. It is a diagram showing the relationship between the fluidity energy in the toner of the present invention and the ventilation flow rate at the time of measurement. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus used in an image forming method of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Photosensitive drum 20 Charging roll 30 Exposure apparatus 40 Developing apparatus 41 Developing container 41A Developing container main body 41B Developing container cover 41C Partition wall 42 Developing roll 42A Developing roll chamber 43 First stirring member 43A First stirring chamber 44 Second stirring member 44A Second stirring chamber 45 Layer thickness regulating member 46 Replenishment transport path 47 Developer hopper 48 Discharge transport path 50 Intermediate transfer belt 50A Stretch roller 50C Backup roller 50D Drive roller 51 Primary transfer roller 52 Secondary transfer roller 53 Recording paper supply device 53A Conveying roller 53B Induction slope 54 Intermediate transfer member cleaning device 60 Neutralizing device 70 Cleaning device 71 Housing 72 Cleaning blade 73 Conveying member 74 Supply conveying path 80 Fixing device 81 Fixing roller 82 Conveyor

Claims (2)

An electrostatic latent image developing toner having at least toner particles and an external additive,
The basic fluidity energy amount is 50 mJ or more and 150 mJ or less when measured with a powder rheometer under conditions of an air flow rate of 0 ml / min, a tip speed of the rotor blade of 100 mm / sec, and an entrance angle of the rotor blade of -5 °,
In addition, the aeration fluid energy amount is 0.5 mJ or more and 15 mJ or less when measured by a powder rheometer under conditions of an air flow rate of 80 ml / min, a tip speed of the rotor blade of 100 mm / sec, and an entrance angle of the rotor blade of -5 °. A toner for developing an electrostatic latent image. A charging step for charging the electrostatic latent image carrier;
A latent image forming step of forming an electrostatic latent image on the surface of the charged electrostatic latent image carrier;
A developing step of developing the electrostatic latent image with a developer including the electrostatic latent image developing toner according to claim 1 to form a toner image on the electrostatic latent image carrier;
A transfer step of transferring the toner image onto a recording medium to form an unfixed transfer image;
A fixing step of fixing the unfixed transfer image transferred onto the recording medium;
An image recording method comprising:

Images