JP6971656B2 - toner - Google Patents

Description

The present invention relates to a toner used in an electrophotographic image forming apparatus.

In recent years, an electrophotographic image forming apparatus has been proposed in which not only ordinary toners such as yellow, magenta, cyan, and black but also bright toners having a metallic luster are used in combination to form a toner image on a transfer material. As a result, when combined with ordinary toner, the hue of the image can be made clearer and various expressions can be made.

Patent Document 1 discloses a toner containing aluminum fine particles having an average aspect ratio (major axis / minor axis) of 1.2 or more and 15 or less and an average major axis D _50n of 200 nm or more and 400 nm or less as a bright colorant. Has been done.

Further, Patent Documents 2 and 3 disclose a technique for suppressing image unevenness by containing a small amount of phosphorus (P) or zinc (Zn) in aluminum fine particles.

Japanese Unexamined Patent Publication No. 2013-134314 JP-A-2015-36747 Japanese Unexamined Patent Publication No. 2015-52650

However, the bright colorant (aluminum fine particles) disclosed in Patent Document 1 tends to be positively charged, and when used for negative toner, the toner is charged non-uniformly and the distribution of the charged amount tends to be broad. As a result, a fog phenomenon may occur on the non-image area, the followability of the charge amount due to a change in the usage environment may be low, and the stability of the image density immediately after the power is turned on may be low.

Further, in the techniques disclosed in Patent Documents 2 and 3, the charge stability in the usage environment may be insufficient, the image density may fluctuate due to the change in the usage environment, or the fog phenomenon may occur. there were.

An object of the present invention is to provide a toner that is excellent in charge uniformity even in a toner using a bright colorant and can stably form a high-quality image regardless of changes in the usage environment.

The present invention is a toner having toner particles containing a binder resin, aluminum fine particles and silica fine particles.
The weight average particle size (D4) of the toner particles is 3.0 μm or more and 10.0 μm or less .
The toner particles contain the aluminum fine particles and the silica fine particles in a region inside 0.3 μm or more from the surface of the toner particles.
The content of the aluminum fine particles in the toner particles is 5.0 parts by mass or more and 30.0 parts by mass or less with respect to 100 parts by mass of the toner particles.
The content of the silica fine particles in the toner particles, Ri 0.1 part by weight to 2.5 parts by der respect to the toner particles 100 parts by weight,
The average aspect ratio (major axis / minor axis) of the silica fine particles is 1.0 or more and 1.2 or less, and the average D _50n of the major axis of the silica fine particles is 30 nm or more and 200 nm or less. It is a characteristic toner.

According to the present invention, it is possible to provide a toner that is excellent in charge uniformity even in a toner using a bright colorant and can stably form a high-quality image regardless of changes in the usage environment.

It is a schematic diagram of a thermal sphere processing apparatus.

The present invention is a toner having toner particles containing a binder resin, aluminum fine particles and silica fine particles.
The weight average particle size (D4) of the toner particles is 3.0 μm or more and 10.0 μm or less .
The toner particles contain the aluminum fine particles and the silica fine particles in a region inside 0.3 μm or more from the surface of the toner particles.
The content of the aluminum fine particles in the toner particles is 5.0 parts by mass or more and 30.0 parts by mass or less with respect to 100 parts by mass of the toner particles.
The content of the silica fine particles in the toner particles, Ri 0.1 part by weight to 2.5 parts by der respect to the toner particles 100 parts by weight,
The average aspect ratio (major axis / minor axis) of the silica fine particles is 1.0 or more and 1.2 or less, and the average D _50n of the major axis of the silica fine particles is 30 nm or more and 200 nm or less. It is a characteristic toner.

The present inventors can neutralize the positive chargeability of the aluminum fine particles by allowing the aluminum fine particles, which are bright colorants, and the silica fine particles to coexist in the toner particles, and the toner has excellent charge uniformity. Was found to be obtained.

One of the features of the present invention is that the toner particles contain aluminum fine particles and silica fine particles in a region of 0.3 μm or more from the surface of the toner particles (hereinafter, also referred to as “near the surface of the toner particles”). It is). The content (internal addition amount) of the aluminum fine particles in the toner particles is 5.0 parts by mass or more and 30.0 parts by mass or less with respect to 100 parts by mass of the toner particles. Further, the content (internal addition amount) of the silica fine particles in the toner particles is 0.1 part by mass or more and 2.5 parts by mass or less with respect to 100 parts by mass of the toner particles.

When the content of the aluminum fine particles in the toner particles is less than 5.0 parts by mass, it is not possible to impart sufficient coloring power to the toner. Further, when the content is more than 30.0 parts by mass, the positive chargeability of the toner becomes large even if silica fine particles coexist in the toner particles, and the charge uniformity of the toner becomes insufficient.

Further, when the content of the silica fine particles in the toner particles is less than 0.1 part by mass, the charge neutralizing action on the aluminum fine particles is reduced, the positive chargeability of the toner is increased, and the charge uniformity of the toner is insufficient. It becomes. Further, when the content is more than 2.5 parts by mass, overcharging of the toner is likely to occur in a low humidity environment. Overcharging of the toner causes a decrease in image density.

Further, the toner particles according to the present invention preferably contain 2.5 parts by mass or more and 7.0 parts by mass or less of silica fine particles in the vicinity of the surface of the toner particles. By arranging the silica fine particles in the vicinity of the surface of the toner particles, it is possible to mitigate the influence of temperature and humidity due to changes in the usage environment and to exhibit excellent charge uniformity under various environments.

Further, the average aspect ratio (major axis / minor axis) of the aluminum fine particles is preferably 1.2 or more and 15 or less. _{Further, the average D 50n} of the major axis of the aluminum fine particles is preferably 200 nm or more and 400 nm or less.

When the average aspect ratio of the aluminum fine particles is 1.2 or more, the coloring area becomes large and a sufficient brilliant effect can be easily obtained. Further, when the aspect ratio is 15 or less, it is difficult to form a needle-like body, and therefore, it is difficult to damage a member such as a photoconductor. A scratch generated on a member such as a photoconductor tends to cause toner fusion or the like from the scratch.

_{Further, when the average D 50n} of the major axis of the aluminum fine particles is 200 nm or more, the coloring area becomes large and a sufficient brilliant effect can be easily obtained. Further, when D _50n is 400 nm or less, the dispersibility of the aluminum fine particles in the toner particles is enhanced, and charging defects are less likely to occur.

Further, the average aspect ratio (major axis / minor axis) of the silica fine particles is preferably 1.0 or more and 1.2 or less. _{Further, the average D 50n} of the major axis of the silica fine particles is preferably 30 nm or more and 200 nm or less.

When the average aspect ratio (major axis / minor axis) of the inorganic fine particles A is 1.2 or less, it is difficult to damage members such as a photoconductor. In addition, the mixture with aluminum fine particles, which is a bright colorant, becomes good, and it is difficult to cause charging failure.

_{Further, when the average D 50n} of the major axis of the silica fine particles is 30 nm or more, the charge neutralizing action on the colorant becomes stronger, and it is less likely to cause a charge defect. _{Further, when the average D 50n} of the major axis of the silica fine particles is 200 nm or less, the dispersibility of the silica fine particles in the toner particles is enhanced, and the charging stability of the toner is further enhanced.

[Bundling resin]
As the binder resin, for example,
Monopolymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene or a substitute (derivative) thereof;
Styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalin copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethacryl Methyl acid acid copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-acrylonitrile-inden copolymer, etc. Styrene-based copolymer;
PVC;
Phenol resin;
Intrinsically disordered phenolic resin;
Natural resin modified maleic acid resin;
acrylic resin;
Methacrylic resin;
Polyvinyl acetate;
Silicone resin;
Polyester resin;
Polyurethane resin;
Polyamide resin;
Furan resin;
Epoxy resin;
Xylene resin;
Polyvinyl butyral;
Terpene resin;
Kumaron-Inden resin;
Petroleum-based resins and the like can be mentioned.

Among these, a polyester resin or a hybrid resin of a polyester and a vinyl polymer is preferable from the viewpoint of low temperature fixability and chargeability control.

In the present invention, the polyester resin is a resin having a "polyester unit" in the resin chain. Examples of the unit constituting the polyester unit include a unit derived from a divalent or higher alcohol monomer component, a divalent or higher carboxylic acid, a divalent or higher carboxylic acid anhydride, and a divalent or higher carboxylic acid ester acid monomer. Examples include units derived from components.

Examples of the divalent or higher alcohol monomer component include, for example.
Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2. 0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) alkylene oxide adduct of bisphenol A such as -2,2-bis (4-hydroxyphenyl) propane, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1 , 4-butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, poly Tetramethylene glycol, sorbit, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5- Examples thereof include pentantriol, glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene and the like.

Among these, aromatic diols are preferable. Among the units derived from the alcohol monomer component constituting the polyester resin, the unit derived from the aromatic diol preferably accounts for 80 mol% or more.

Examples of the acid monomer component such as a divalent or higher carboxylic acid, a divalent or higher carboxylic acid anhydride, and a divalent or higher carboxylic acid ester include, for example.
Aromatic dicarboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid or their anhydrides;
Alkyldicarboxylic acids such as succinic acid, adipic acid, sebacic acid and azelaic acid or their anhydrides;
Succinic acid or anhydrate thereof substituted with an alkyl group or an alkenyl group having 6 to 18 carbon atoms;
Examples thereof include unsaturated dicarboxylic acids such as fumaric acid, maleic acid and citraconic acid, or anhydrides thereof.

Among these, polyvalent carboxylic acids such as terephthalic acid, succinic acid, adipic acid, fumaric acid, trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid or their anhydrides are preferable.

The acid value of the polyester resin is preferably 1 mgKOH / g or more and 20 mgKOH / g or less from the viewpoint of stability of the triboelectric charge amount.

The acid value of the polyester resin can be controlled by adjusting the type and blending amount of the monomer used in the production of the polyester resin. For example, it can be controlled by adjusting the ratio of the alcohol monomer component and the acid monomer component at the time of producing the polyester resin and the molecular weight of the polyester resin. It can also be controlled by reacting the terminal alcohol with a polyhydric acid monomer (for example, trimellitic acid) after ester polycondensation.

Further, as a method for obtaining a hybrid resin of a polyester and a vinyl-based polymer, a method of performing a polymerization reaction for producing a vinyl-based polymer and / or a polyester in the presence of a vinyl-based polymer and / or a monomer component capable of reacting with the polyester is used. preferable.

[wax]
Wax may be contained in the toner particles according to the present invention.

As wax, for example
Hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, alkylene copolymers, microcrystalline wax, paraffin wax, Fishertroph wax;
Hydrocarbon wax oxides such as polyethylene oxide wax or block copolymers thereof;
Waxes whose main component is fatty acid ester such as carnauba wax;
Deoxidized Part or all of fatty acid esters such as carnauba wax deoxidized;
Saturated linear fatty acids such as palmitic acid, stearic acid, and montanic acid;
Unsaturated fatty acids such as brushzic acid, eleostearic acid, and varinaphosphoric acid;
Saturated alcohols such as stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnaubil alcohol, ceryl alcohol, and mericyl alcohol;
Multivalent alcohols such as sorbitol;
Esters of fatty acids such as palmitic acid, stearic acid, behenic acid, and montanic acid with alcohols such as stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvir alcohol, ceryl alcohol, and mericyl alcohol;
Fatty acid amides such as linoleic acid amides, oleic acid amides, and lauric acid amides;
Saturated fatty acid bisamides such as methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, hexamethylene bisstearic acid amide;
Unsaturated fatty acid amides such as ethylene bisoleic acid amides, hexamethylene bisoleic acid amides, N, N'diorail adipic acid amides, N, N'diorail sevacinic acid amides;
Aromatic bisamides such as m-xylene bisstearic acid amide, N, N'distearyl isophthalic acid amide;
Aliper metal salts such as calcium stearate, calcium laurate, zinc stearate, magnesium stearate (generally called metal soap);
Waxes obtained by grafting an aliphatic hydrocarbon wax with a vinyl monomer such as styrene or acrylic acid;
Partial esterification of fatty acids such as behenic acid monoglyceride and polyhydric alcohols;
Examples thereof include methyl ester compounds having a hydroxyl group obtained by hydrogenation of vegetable oils and fats.

Among these, hydrocarbon waxes such as paraffin wax and Fischer-Tropsch wax are preferable from the viewpoint of improving low temperature fixing property and wrapping resistance of fixing member.

The wax content in the toner particles is preferably 0.5 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the binder resin in the toner particles.

From the viewpoint of achieving both toner storage stability and high temperature offset property, the maximum endothermic peak existing in the range of 30 ° C. or higher and 200 ° C. or lower in the endothermic curve at the time of temperature rise measured by the differential scanning calorimetry device (DSC). The peak temperature is preferably 50 ° C. or higher and 110 ° C. or lower.

[Charge control agent]
The toner particles according to the present invention may contain a charge control agent.

As the charge control agent, a metal compound of an aromatic carboxylic acid which is colorless, has a high charge speed of the toner, and can stably maintain the charge amount is preferable.

As a negative charge control agent, for example,
Metallic salicylate compound, metal naphthoic acid compound, metal dicarboxylic acid compound, polymer compound having sulfonic acid or carboxylic acid in the side chain;
A high molecular weight compound having a sulfonate or a sulfonic acid esterified product in the side chain;
Polymeric compounds with carboxylates or carboxylic acid esters in their side chains;
Boron compound;
Urea compound;
Silicon compound;
Calixarene and the like.

The charge control agent may be added internally or externally to the toner particles.

The content of the charge control agent in the toner particles is preferably 0.2 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the binder resin in the toner particles.

[External agent]
The toner of the present invention may have an external additive for improving the fluidity and adjusting the triboelectric charge amount.

Examples of the external additive include inorganic fine particles such as silicon oxide (silica), titanium oxide (titania), aluminum oxide (alumina), and strontium titanate.

The external additive (inorganic fine particles) is preferably hydrophobized with a hydrophobizing agent such as a silane compound, silicone oil or a mixture thereof.

^{The specific surface area of the external additive (inorganic fine particles) is preferably 10 m 2} / g or more and 50 m ² / g or less from the viewpoint of suppressing the embedding of the external additive (inorganic fine particles).

The content of the external additive in the toner is preferably 0.1 part by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the toner particles.

[Career]
From the viewpoint of obtaining a stable image for a long period of time, the toner of the present invention is preferably mixed with a magnetic carrier and used as a two-component developer.

As a magnetic carrier, for example,
Iron powder with oxidized surface or unoxidized iron powder;
Metal particles such as iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, rare earth, or their alloy particles or oxide particles;
Magnetic material such as ferrite;
A magnetic material-dispersed resin carrier (so-called resin carrier) containing a magnetic material and a binder resin that holds the magnetic material in a dispersed state.
And so on.

[Production method]
Examples of the method for producing the toner of the present invention include an emulsion aggregation method, a melt-kneading method, and a dissolution-suspension method.

Among these, the melt-kneading method is preferable from the viewpoint of dispersibility of raw materials.

The melt-kneading method is characterized in that a toner composition which is a raw material of toner particles is melt-kneaded and the obtained kneaded product is pulverized.

The melt-kneading method will be described in more detail.

In the raw material mixing step, as raw materials for the toner particles, a binder resin, aluminum fine particles and silica fine particles, and if necessary, components such as wax and a colorant are weighed and mixed in a predetermined amount and mixed. Examples of the mixing device include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, a Nauter mixer, and a mechano hybrid (manufactured by Nippon Coke Industries, Ltd.).

Next, the mixed materials are melt-kneaded to disperse other raw materials and the like in the binder resin.

In the melt-kneading step, for example, a batch-type kneader such as a pressure kneader or a Bambary mixer, or a continuous-type kneader can be used. Due to the superiority of continuous production, single-screw or two-screw extruders have become the mainstream.

As an extruder, for example
KTK type 2-axis extruder (manufactured by Kobe Steel, Ltd.), TEM type 2-axis extruder (manufactured by Toshiba Machine Co., Ltd.), PCM kneader (manufactured by Ikekai Co., Ltd.), 2-axis extruder (KTC)・ Ktk Inc.), Co Kneader (Bus Co., Ltd.), Kneedex (Nippon Coke Industries Co., Ltd.)
And so on.

The resin composition obtained by melt-kneading is rolled with two rolls or the like. Further, the resin composition may be cooled with water or the like in the cooling step.

Next, the cooled product of the resin composition is pulverized to a desired particle size in the pulverization step.

In the pulverization step, after coarse pulverization with a pulverizer, further pulverization is performed with a fine pulverizer. Examples of the crusher used for coarse crushing include a crusher, a hammer mill, and a feather mill. Examples of the pulverizer used for pulverization include Cryptron System (manufactured by Kawasaki Heavy Industries, Ltd.), Super Rotor (manufactured by Nisshin Engineering Co., Ltd.), Turbo Mill (manufactured by Turbo Industries, Ltd.), and Air Jet. Examples include a fine crusher according to the method.

Then, if necessary, the toner particles are classified using a classifier or a sieving machine to obtain toner particles.

As a classifier or a sieving machine, for example,
Inertial classification elbow jet (manufactured by Nittetsu Mining Co., Ltd.), centrifugal force classification turboplex (manufactured by Hosokawa Micron Co., Ltd.), TSP separator (manufactured by Hosokawa Micron Co., Ltd.), faculty (manufactured by Hosokawa Micron Co., Ltd.)
And so on.

Also, after crushing, if necessary,
Hybridization system (manufactured by Nara Machinery Co., Ltd.), Mechanofusion system (manufactured by Hosokawa Micron Co., Ltd.), Faculty (manufactured by Hosokawa Micron Co., Ltd.), Meteole Invo MR Type (manufactured by Nippon Pneumatic Industries Co., Ltd.)
It is also possible to perform surface treatment of toner particles such as sphericalization treatment by using the above.

In the present invention, additives such as inorganic fine particles and resin particles are added to the surface of the toner particles obtained by the above-mentioned production method, mixed and dispersed, and in the dispersed state, the additive is subjected to surface treatment with hot air. It is preferable to fix it on the surface of the toner particles.

For example, toner can be obtained by performing surface treatment with hot air using the thermal spheroidizing treatment apparatus shown in FIG. 1 and classifying the surface as necessary.

In the thermal sphere processing apparatus shown in FIG. 1, the mixture (raw material) quantitatively supplied by the raw material supply means 1 was installed on the vertical line of the raw material supply means 1 by the compressed gas adjusted by the compressed gas adjusting means 2. It is guided to the introduction pipe 3. The mixture that has passed through the introduction pipe 3 is uniformly dispersed by the conical protrusion-shaped member 4 provided in the central portion of the raw material supply means 1, guided to the supply pipe 5 in eight directions spreading radially, and heat-treated. It is guided to the processing chamber 6.

At this time, the flow of the mixture supplied to the processing chamber 6 is regulated by the regulating means 9 for regulating the flow of the mixture provided inside the processing chamber 6. Therefore, the mixture supplied to the processing chamber 6 is heat-treated while swirling inside the processing chamber, and then cooled.

The heat for heat-treating the supplied mixture is supplied as hot air from the hot air supply means 7, and is distributed by the distribution member 12. The hot air is spirally swirled and introduced inside the processing chamber 6 by the swirling member 13 for swirling the hot air. As its configuration, the swivel member 13 has a plurality of blades, and the swirl of hot air can be controlled by the number and angles thereof. The temperature of the hot air supplied to the inside of the processing chamber 6 at the outlet of the hot air supply means 7 is preferably 100 ° C. or higher and 300 ° C. or lower, and more preferably 130 ° C. or higher and 170 ° C. or lower. When the temperature at the outlet of the hot air supply means 7 is within the above range, the toner particles are uniformly spherical (heat spherical) while suppressing the fusion and coalescence of the toner particles due to overheating of the mixture. Easy to handle. The circularity at this time is preferably 0.955 or more and 0.980 or less. The hot air is supplied from the hot air supply means outlet 11.

The heat-treated toner particles are cooled by the cold air supplied from the cold air supply means 8. The temperature of the cold air supplied from the cold air supply means 8 is preferably −20 ° C. or higher and 30 ° C. or lower. When the temperature of the cold air is within the above range, the heat-treated toner particles can be efficiently cooled, the uniform sphericalization (heat sphericalization) treatment of the mixture is less likely to be hindered, and the heat-treated toner particles are fused or coalesced. One can be suppressed. The absolute water content of the cold air ^{is preferably 0.5 g / m 3} or more and 15.0 g / m ³ or less.

Next, the cooled heat-treated toner particles are recovered by the recovery means 10 at the lower end of the processing chamber. A blower (not shown) is provided at the tip of the recovery means 10, and the blower is sucked and conveyed by the blower (not shown).

Further, the powder particle supply port 14 is provided so that the swirling direction of the supplied mixture and the swirling direction of the hot air are in the same direction. The recovery means 10 is provided on the outer peripheral portion of the processing chamber 6 so as to maintain the swirling direction of the swirled powder particles. Further, the cold air supplied from the cold air supply means 8 is configured to be supplied horizontally and tangentially to the inner peripheral surface of the processing chamber 6 from the outer peripheral portion of the apparatus. The swirling direction of the toner particles before heat treatment supplied from the powder particle supply port 14, the swirling direction of the cold air supplied from the cold air supply means 8, and the swirling direction of the hot air supplied from the hot air supply means 7 are all in the same direction. Is. As a result, turbulence does not occur inside the processing chamber 6, the swirling flow in the apparatus is strengthened, a strong centrifugal force is applied to the toner particles before heat treatment, and the dispersibility of the toner particles before heat treatment is further improved. Therefore, it is possible to obtain heat-treated toner particles having a uniform shape with few coalesced particles.

After that, an external additive such as inorganic fine particles or resin particles may be added and mixed to improve the fluidity and charge stability of the toner. Examples of the mixing device include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, a Nauter mixer, and a mechano hybrid (manufactured by Nippon Coke Industries, Ltd.).

<Measurement of aspect ratio (major axis / minor axis) of aluminum fine particles and silica fine particles and average _{D50n of major axis>
For the average D 50n} of the major axis of the aluminum fine particles and the silica fine particles, observe with a transmission electron microscope, measure the particle size of 100 particles, and set the average value of the length of the major axis to the average D _{50n of the major axis.} bottom. Similarly, the average value of the length of the minor axis was obtained and used as the average of the minor axis. The aspect ratio was determined by dividing the major axis (length of the major axis) by the minor axis (length of the minor axis).

<Method for measuring the content (internal addition amount) of aluminum fine particles and silica fine particles near the surface of toner particles>
To 200 mL of ion-exchanged water, 2 mL of a nonionic surfactant (trade name: Contaminone N, manufactured by Wako Pure Chemical Industries, Ltd.) is added, and dispersion treatment is performed for 10 hours with an ultrasonic disperser. In this way, the entire amount of the toner external additive is released, and the content of the aluminum fine particles and silica fine particles existing inside the toner particles is calculated by fluorescent X-ray measurement.

The measurement of fluorescent X-rays of each element conforms to JIS K0119-1969. Specifically, it is as follows.

As a measuring device
Wavelength dispersive fluorescent X-ray analyzer (trade name: Axios, manufactured by PANalytical),
Use the attached dedicated software (trade name: SuperQ ver. 4.0F, manufactured by PANalytical) for setting measurement conditions and analyzing measurement data. Further, Rh is used as the anode of the X-ray tube, the measurement atmosphere is vacuum, the measurement diameter (collimator mask diameter) is 27 mm, and the measurement time is 10 seconds. When measuring a light element with the same device, it is detected by a proportional counter (PC), and when measuring a heavy element, it is detected by a scintillation counter (SC).

As a measurement sample, put about 4 g of toner in a special aluminum ring for pressing and flatten it. Then, using a tablet molding compressor (trade name: BRE-32, manufactured by Maekawa Testing Machine Mfg. Co., Ltd.), pressurize at 20 MPa for 60 seconds, and use pellets molded to a thickness of about 2 mm and a diameter of about 39 mm.

Measurement is performed under the above conditions, an element is identified based on the obtained peak position of X-rays, and the concentration of the element is calculated from the counting rate (unit: cps) which is the number of X-ray photons per unit time. ..

In the case of aluminum fine particles, the aluminum fine particles are added so as to be 5.0 parts by mass with respect to 100 parts by mass of the toner particles, and the mixture is mixed using a coffee mill. Similarly, the aluminum fine particles are mixed with the toner particles so as to be 10.0 parts by mass and 30.0 parts by mass, respectively, and these are used as a sample for the calibration curve.

In the case of silica fine particles, the silica fine particles are mixed with the toner particles so as to be 0.1 part by mass, 1.0 part by mass, and 2.5 parts by mass with respect to 100 parts by mass of the toner particles, and these are used for the calibration curve. The sample is.

For each sample, pellets of the sample for the calibration curve were prepared as described above using the above-mentioned tablet molding compressor, and observed at a diffraction angle (2θ) = 109.08 ° when PET was used for the spectroscopic crystal. The count rate (unit: cps) of the Si—Kα ray to be generated is measured. At this time, the acceleration voltage and current value of the X-ray generator are set to 24 kV and 100 mA, respectively. A calibration curve having a linear function is obtained with the obtained X-ray count rate on the vertical axis and the amount of aluminum fine particles or silica fine particles in each calibration curve sample on the horizontal axis.

Next, using the tablet molding compressor, the toner to be analyzed is pelletized as described above, and the count rate of Si—Kα rays is measured. Then, the content of aluminum fine particles or silica fine particles in the toner particles is calculated from the calibration curve.

<Measurement of melting point of wax>
The melting point of the wax is defined as the peak temperature of the maximum endothermic peak in the DSC curve measured according to ASTM D3418-82 using a differential scanning calorimeter (trade name: Q2000, manufactured by TA Instruments).

The melting points of indium and zinc are used for temperature correction of the device detector, and the heat of fusion of indium is used for heat quantity correction. Specifically, about 2 mg of a sample is precisely weighed, placed in an aluminum pan, and an empty aluminum pan is used as a reference, and the temperature rise rate is between 30 ° C. and 200 ° C. in the measurement temperature range. Measure at 10 ° C./min. In the measurement, the temperature is raised to 200 ° C., then lowered to 30 ° C., and then raised again.

The maximum endothermic peak temperature of the DSC curve in the temperature range of 30 ° C. to 200 ° C. in the second temperature raising process is defined as the melting point. Here, there is no holding time after raising the temperature to 200 ° C., and as soon as the temperature reaches 200 ° C., the temperature is lowered to 30 ° C.

<Measurement of weight average particle size (D4) of toner>
The weight average particle size (D4) of the toner is
Precise particle size distribution measuring device by pore electrical resistance method equipped with a 100 μm aperture tube (trade name: Coulter Counter Multisizer3, manufactured by Beckman Coulter), and an attached dedicated device for setting measurement conditions and analyzing measurement data. Soft (Product name: Beckman Coulter Measurement 3.51, manufactured by Beckman Coulter)
Is used to measure with an effective measurement channel number of 25,000 channels, and the measurement data is analyzed and calculated. The electrolytic aqueous solution used for the measurement is prepared by dissolving special grade sodium chloride in deionized water so that the concentration becomes about 1% by mass, specifically, "ISOTONII" (manufactured by Beckman Coulter) is used. ..

Before performing measurement and analysis, set the dedicated software as follows.

In the dedicated software "Change standard measurement method (SOM) screen", set the total count number in the control mode to 50,000 particles, set the number of measurements to 1 time, and set the Kd value to "standard particles 10.0 μm" (Beckman Coulter). Set the value obtained using (manufactured by the company). By pressing the threshold / noise level measurement button, the threshold and noise level are automatically set. Also, set the current to 1600 μA, the gain to 2, and the electrolyte to ISOTONII, and check the flash of the aperture tube after measurement. In the dedicated software "Pulse to particle size conversion setting screen", set the bin spacing to logarithmic particle size, the particle size bin to 256 particle size bins, and the particle size range from 2 μm to 60 μm.

The specific measurement method is as follows (1) to (7).

(1) Put about 200 mL of the above electrolytic aqueous solution in a 250 mL round bottom beaker made of glass exclusively for Multisizer3, set it on a sample stand, and stir the stirrer rod counterclockwise at 24 rpm. Then, the "aperture flash" function of the analysis software removes dirt and air bubbles in the aperture tube.

(2) Approximately 30 mL of the above electrolytic aqueous solution is placed in a 100 mL flat-bottomed beaker made of glass, and approximately 0.3 mL of a diluted solution obtained by diluting the above "contamination N" with deionized water 3 times by mass as a dispersant is contained therein. Add.

(3) Put a predetermined amount of deionized water in the water tank of an ultrasonic disperser (trade name: Ultrasonic Dispersion System Tetora150) (manufactured by Nikkaki Bios Co., Ltd.), and put the above "contamination N" in this water tank. About 2 mL is added. The ultrasonic disperser has two built-in oscillators with an oscillation frequency of 50 kHz with the phase shifted by 180 degrees, and the electrical output is 120 W.

(4) The beaker of the above (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. Then, the height position of the beaker is adjusted so that the resonance state of the liquid level of the electrolytic solution in the beaker is maximized.

(5) With the electrolytic aqueous solution in the beaker of (4) above being irradiated with ultrasonic waves, about 10 mg of toner is added little by little to the electrolytic aqueous solution and dispersed. Further, the ultrasonic dispersion processing is continued for 60 seconds. For ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted to be 10 ° C. or higher and 40 ° C. or lower.

(6) Using a pipette, drop the aqueous electrolyte solution of (5) above into the round bottom beaker of (1) above installed in the sample stand so that the measured concentration becomes about 5%. adjust. Then, the measurement is performed until the number of measured particles reaches 50,000.

(7) The measurement data is analyzed by the above-mentioned dedicated software attached to the device, and the volume average particle size (D4) is calculated. The "average diameter" of the analysis / volume statistic (arithmetic mean) screen when the graph / volume% is set by the dedicated software is the weight average particle diameter (D4).

<Measuring method of average circularity of toner>
The average circularity of the toner is measured by a flow-type particle image analyzer (trade name: FPIA-3000, manufactured by Sysmex Corporation) under the measurement and analysis conditions at the time of calibration work.

The measurement principle of the flow-type particle image analyzer is to capture a flowing particle as a still image and perform image analysis. The sample added to the sample chamber is sent to the flat sheath flow cell by the sample suction syringe. The sample sent into the flat sheath flow is sandwiched between the sheath liquids to form a flat flow. The sample passing through the flat sheath flow cell is irradiated with strobe light at 1/60 second intervals, and it is possible to take a still image of the flowing particles. Moreover, since the flow is flat, the image is taken in a focused state. The particle image is captured by a CCD camera, and the captured image is image-processed at an image processing resolution of 512 × 512 pixels (0.37 μm × 0.37 μm per pixel), the contour of each particle image is extracted, and the particle image is obtained. The projected area S, the peripheral length L, and the like are measured.

Next, the circle-equivalent diameter and the circularity are obtained by using the area S and the perimeter L. The circle equivalent diameter is the diameter of a circle having the same area as the projected area of the particle image, and the circularity C is the value obtained by dividing the circumference length of the circle obtained from the circle equivalent diameter by the circumference length of the particle projection image. It is defined as and calculated by the following formula.

Circularity C = 2 × (π × S) 1/2 / L
When the particle image is circular, the circularity becomes 1.000, and the larger the degree of unevenness on the outer periphery of the particle image, the smaller the circularity. After calculating the circularity of each particle, the range of circularity 0.200 to 1.000 is divided into 800, the arithmetic mean value of the obtained circularity is calculated, and the value is taken as the average circularity.

The specific measurement method is as follows.

First, about 20 mL of ion-exchanged water from which impure solids and the like have been removed in advance is placed in a glass container. To this, add about 0.2 mL of a diluted solution obtained by diluting the above "contamination N" with ion-exchanged water about 3 times by mass as a dispersant. Further, about 0.02 g of the measurement sample is added, and the dispersion treatment is performed for 2 minutes using an ultrasonic disperser to prepare a dispersion liquid for measurement. At that time, the dispersion liquid is appropriately cooled so that the temperature is 10 ° C. or higher and 40 ° C. or lower. As the ultrasonic disperser, a desktop ultrasonic cleaner disperser (trade name: VS-150, manufactured by Vervocrea) having an oscillation frequency of 50 kHz and an electric output of 150 W was used. A predetermined amount of ion-exchanged water is placed in the water tank, and about 2 mL of the above "contamination non-N" is added to the water tank.

The flow-type particle image analyzer equipped with a standard objective lens (10x) was used for the measurement, and a particle sheath (trade name: PSE-900A, manufactured by Sysmex Corporation) was used as the sheath liquid. The dispersion liquid prepared according to the above procedure is introduced into the above flow type particle image analyzer, and 3000 toner particles are measured in the total count mode in the HPF measurement mode. Then, by setting the binarization threshold value at the time of particle analysis to 85% and designating the analysis particle diameter, the number ratio (%) of the particles in that range and the average circularity are calculated. The average circularity of the toner was set to a circle equivalent diameter of 1.98 μm or more and 39.96 μm or less, and the average circularity of the toner was determined.

In the measurement, automatic focus adjustment is performed using standard latex particles (specifically, "RESEARCH AND TEST PARTICLES Latex Microsphere Suspensions 5200A" manufactured by Duke Scientific) is diluted with ion-exchanged water before the start of the measurement. After that, it is preferable to perform focus adjustment every two hours from the start of measurement.

In the following examples, a flow-type particle image analyzer that has been calibrated by Sysmex and has received a calibration certificate issued by Sysmex was used. The measurement was performed under the measurement and analysis conditions when the calibration certificate was obtained, except that the particle size of the analysis particle was limited to the equivalent circle diameter of 1.98 μm or more and less than 39.69 μm.

Hereinafter, the present invention will be described in more detail based on Examples.

<Production example of aluminum fine particles 1 to 7>
A high-brightness grade flake-shaped aluminum paste 574PS (metal content: 75.0%, number average particle size: 13 μm) manufactured by Showa Aluminum Powder Co., Ltd. was crushed by a ball mill using glass beads. In this way, aluminum fine particles 1 to 7 (bright colorants) having _{an average D 50n with a major axis and an aspect ratio (major axis / minor axis) shown in Table 1 were obtained.}

<Production example of titania fine particles>
The _{ilmenite ore containing 50% by mass of TiO 2} equivalent was dried at 150 ° C. for 3 hours and then dissolved by adding sulfuric acid to obtain an aqueous solution of _{TiOSO 4.}

After concentrating the obtained aqueous solution, 8 parts by mass of titania sol having rutile-type crystals was added as a seed, and then hydrolysis was carried out at 150 ° C. to obtain a slurry of _{TiO (OH) 2 containing impurities.}

This slurry was repeatedly washed with water having a pH of 5 to 6 _{to sufficiently remove sulfuric acid, FeSO 4} and impurities to obtain a slurry of high-purity metatitanic acid [TIO (OH) _2].

After filtering this slurry, _{0.5 parts by mass of lithium carbonate (Li 2} CO ₃ ) is added, and the particles are fired at 320 ° C. for 5 hours, and then repeatedly crushed by a jet mill to obtain primary particles having rutile-type crystals. Titania fine particles (brilliant colorant) having an average particle size of 70 nm were obtained.

<Production example of silica fine particles 1>
Silica fine particles to be contained (internally added) in the toner particles were produced by a combustion method using hexamethylcyclotrisiloxane as a raw material. For the combustion furnace, a hydrocarbon-oxygen mixed burner having a double-tube structure capable of forming an internal flame and an external flame was used. A two-fluid nozzle for slurry injection was grounded in the center of the burner, and a raw material silicon compound was introduced. A flammable gas of hydrocarbon-oxygen was injected from around the two-fluid nozzle to form an internal flame and an external flame, which are reducing atmospheres. By controlling the amount and flow rate of flammable gas and oxygen, the atmosphere and temperature, the length of the flame, etc. were adjusted. Silica fine particles were formed from the silicon compound in the flame and further fused until the desired particle size was obtained. Then, after cooling, the silica bulk material was obtained by collecting it with a bag filter or the like.

The obtained silica raw material 99.5% by mass was surface-treated with 0.5% by mass of hexamethyldisilazane to obtain silica fine particles 1 to be contained (internally added) in the toner particles. The average particle size of the number of primary particles of the obtained silica fine particles 1 was 110 nm.

<Production example of silica fine particles 2 to 7>
Toner particles were produced by the same method as silica fine particles 1 except that the number average particle size of the silica base was changed as shown in Table 2 by changing the amount and flow rate of flammable gas and oxygen. 2 to 7 of silica fine particles to be contained in (internally added) were obtained.

[Manufacturing example of polyester resin L]
Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane: 72.0 parts by mass (0.20 mol, 100.0 mol% based on the total number of moles of polyhydric alcohol)
-Terephthalic acid: 28.0 parts by mass (0.17 mol, 96.0 mol% based on the total number of moles of polyvalent carboxylic acid)
-Tin 2-ethylhexanoate (esterification catalyst): 0.5 parts by mass The above materials were weighed and placed in a reaction vessel equipped with a cooling tube, a stirrer, a nitrogen introduction tube and a thermocouple. Next, after replacing the inside of the flask with nitrogen gas, the temperature was gradually raised while stirring, and the reaction was carried out for 4 hours while stirring at a temperature of 200 ° C.

Further, the pressure in the reaction vessel was lowered to 8.3 kPa, maintained for 1 hour, cooled to 180 ° C., and returned to atmospheric pressure (first reaction step).

Trimellitic acid anhydride: 1.3 parts by mass (0.01 mol, 4.0 mol% based on the total number of moles of polyvalent carboxylic acid)
-Tert-Butylcatechol (polymerization inhibitor): 0.1 part by mass Then, the above material was added, the pressure in the reaction vessel was lowered to 8.3 kPa, and the reaction was carried out for 1 hour while maintaining the temperature at 180 ° C. Then, after confirming that the softening point measured according to ASTM D36-86 reached 94 ° C., the temperature was lowered to stop the reaction. In this way, a polyester resin L (binding resin) was obtained (second reaction step).

The softening point (Tm) of the obtained polyester resin L was 94 ° C., and the glass transition temperature (Tg) was 57 ° C.

[Production example of polyester resin H]
Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane: 72.3 parts by mass (0.20 mol, 100.0 mol% based on the total number of moles of polyhydric alcohol)
-Terephthalic acid: 18.3 parts by mass (0.11 mol, 65.0 mol% with respect to the total number of moles of polyvalent carboxylic acid)
Fumaric acid: 2.9 parts by mass (0.03 mol, 15.0 mol% based on the total number of moles of polyvalent carboxylic acid)
-Tin 2-ethylhexanoate (esterification catalyst): 0.5 parts by mass The above materials were weighed and placed in a reaction vessel equipped with a cooling tube, a stirrer, a nitrogen introduction tube and a thermocouple. Next, after replacing the inside of the flask with nitrogen gas, the temperature was gradually raised while stirring, and the reaction was carried out for 2 hours while stirring at a temperature of 200 ° C.

Further, the pressure in the reaction vessel was lowered to 8.3 kPa, maintained for 1 hour, cooled to 180, and returned to atmospheric pressure (first reaction step).

Trimellitic acid anhydride: 6.5 parts by mass (0.03 mol, 20.0 mol% based on the total number of moles of polyvalent carboxylic acid)
-Tert-Butylcatechol (polymerization inhibitor): 0.1 part by mass Then, the above material was added, the pressure in the reaction vessel was lowered to 8.3 kPa, and the reaction was carried out for 15 hours while maintaining the temperature at 160 ° C. Then, after confirming that the softening point measured according to ASTM D36-86 reached 132 ° C., the temperature was lowered to stop the reaction. In this way, the polyester resin H (binding resin) was obtained (second reaction step).

The softening point (Tm) of the obtained polyester resin H was 132 ° C., and the glass transition temperature (Tg) was 61 ° C.

[Example 1]
<Manufacturing example of toner 1>
-Polyester resin L 75.00 parts by mass-Polyester resin H 25.00 parts by mass-Fishertropsh wax (peak temperature of maximum heat absorption peak: 90 ° C) 5.00 parts by mass-Aluminum fine particles 1 (brilliant colorant) 10.00 Parts by mass ・ 3,5-Di-t-aluminum salicylate compound 0.50 parts by mass ・ Silica fine particles 11.00 parts by mass Henshell mixer (trade name: FM-75 type, manufactured by Mitsui Mine Co., Ltd.) ) Was used, and the mixture was mixed under the conditions of rotation speed: 20 seconds ^{-1 and rotation time: 5 minutes.} Then, it was kneaded with a PCM kneader (trade name: PCM-30 type, manufactured by Ikekai Co., Ltd.) whose temperature was set to 125 ° C. The obtained kneaded product was cooled and coarsely pulverized with a hammer mill to 1 mm or less to obtain a coarsely crushed product. The obtained coarse crushed product was finely pulverized with a mechanical crusher (trade name: T-250, manufactured by Turbo Industries, Ltd.). Further, classification was performed using a rotary classifier (trade name: 200TSP, manufactured by Hosokawa Micron Co., Ltd.) to obtain toner particles. As the operating condition of the rotary type classifier, the classifier rotor rotation speed was set to 50.0 seconds- ¹ . The obtained toner particles had a weight average particle size (D4) of 5.7 μm.

Add 4.5 parts by mass of silica fine particles 1 (as an external additive) to 100 parts by mass of the obtained toner particles, and rotate using a Henshell mixer (trade name: FM-75 type, manufactured by Mitsui Mine Co., Ltd.). The mixture was mixed under the conditions of number: 30 seconds- ^{1, rotation time: 10 minutes.} The obtained mixture was heat-treated by the surface treatment apparatus shown in FIG. 1 to obtain heat-treated toner particles. The operating conditions were feed amount: 5 kg / hour. Hot air temperature C: 220 ° C, hot air flow rate: 6 m ³ / min, cold air temperature E: 5 ° C, cold air flow rate: 4 m ³ / min, cold air absolute water content: 3 g / m ³ , blower air volume: 20 m ³ / min, Injection air flow rate was 1 m ³ / min.

The obtained heat-treated toner particles had an average circularity of 0.963 and a weight average particle size (D4) of 6.2 μm.

To 100 parts by mass of the obtained heat-treated toner particles, 0.5 parts by mass of titania fine particles (as an external additive) having a primary average particle size of 32.0 nm were added. Then, the mixture was mixed with a Henshell mixer (FM75 type, manufactured by Mitsui Miike Machinery Co., Ltd.) at a peripheral speed of 45 m / sec for 5 minutes, and passed through an ultrasonic vibration sieve having an opening of 54 μm to obtain toner 1.

[Examples 2 to 19 and Comparative Examples 1 to 4]
<Manufacturing Examples of Toners 2 to 18 and Comparative Toners 1 to 4>
As shown in Table 3, toners 2 to 21 and comparative toners 1 to 7 were produced in the same manner as in the production example of toner 1, except that the types and contents of the bright colorant and the silica fine particles were changed.

[Example 1]
<Production example of two-component developer 1>
So that the toner concentration is 9% by mass
Toner 1 and
Using a V-type mixer (trade name: V-10 type, Tokuju Seisakusho Co., Ltd.) with magnetic ferrite carrier particles (number average particle size: 35 μm) having a surface coating layer of silicone resin, the number of revolutions: 0. Mixing was performed under the conditions of 5 seconds ^-1 and rotation time: 5 minutes to obtain a two-component developer 1. The two-component developer 1 was used as the two-component developer for Example 1.

[Examples 2 to 19 and Comparative Examples 1 to 4]
<Production Examples of Two-Component Developers 2 to 19 and Comparative Two-Component Developers 1 to 4>
The two-component developer 2 to 19 and the comparative two-component developer 1 to 4 were used in the same manner as in the production example of the two-component developer 1 except that the toner 1 was changed to the toners 2 to 19 and the comparative toners 1 to 4. Manufactured. The two-component developer 2 to 19 and the comparative two-component developer 1 to 4 were used as the two-component developer for Examples 2 to 19 and Comparative Examples 1 to 4, respectively. In addition, Examples 14 to 18 are described as reference examples.

[Examples 1 to 19 and Comparative Examples 1 to 4]
<Evaluation of dichotomous developer 1>
<Evaluation 1> Evaluation of image density stability Put the two-component developer 1 in the cyan station of a full-color copier (trade name: image PRESS C800) manufactured by Canon Inc., and put the two-component developer 1 on the toner paper of the FFH image (solid part). The development conditions were adjusted so that the loading amount on the plate was 1.2 mg / cm ^2. The FFH image is a value in which 256 gradations are displayed in hexadecimal, and 00H is the first gradation (plain part) and FFH is the 256th gradation (solid part).

As the evaluation paper, black paper having an image density of 1.5 or more was used.

The following evaluations 1-1 to 1-3 were performed while supplying toner 1 as needed.

The evaluation results are shown in Table 3.

The image density was measured using an X-Rite color reflection densitometer (trade name: 500 series: manufactured by X-Rite).

(Evaluation 1-1) Evaluation of stability of image density in low temperature and low humidity environment (15 ° C, 10% RH) First, 500 sheets continuous paper passing test in low temperature and low humidity environment (15 ° C, 10% RH) ( A4 paper horizontal, printing ratio: 80%) was performed.

During the 500-sheet continuous paper-passing test, it was decided to carry out paper-passing under the same development conditions and transfer conditions (without calibration) as for the first sheet.

(Evaluation 1-2) Evaluation of image density stability immediately after changing from a low temperature and low humidity environment (15 ° C, 10% RH) to a high temperature and high humidity environment (30 ° C, 80% RH) Next, the image output environment After changing from a low temperature and low humidity environment (15 ° C, 10% RH) to a high temperature and high humidity environment (30 ° C, 80% RH) over 8 hours, 500 sheets of continuous paper are passed in the same manner as in Evaluation 1-1. A test (A4 paper width, printing ratio: 80%) was performed.

(Evaluation 1-3) Evaluation of image density stability in a high temperature and high humidity environment (30 ° C, 80% RH) Next, leave the image in a high temperature and high humidity environment (30 ° C, 80% RH) for 8 hours or more. After being sufficiently acclimatized to the usage environment, a 500-sheet continuous paper passing test (A4 paper width, printing ratio: 80%) was performed in the same manner as in Evaluation 1-1.

(Evaluation of image density stability during 500-sheet continuous paper passing test)
The image density of all FFH image parts (solid parts) of the 500 images output in each environment is measured, and the density difference between the highest density image and the lowest density image is calculated for each environment. As evaluation 1-1 and evaluation 1-3, the concentration stability performance under each environment was evaluated according to the following criteria. In addition, as evaluation 1-2, the environmental change tracking performance was evaluated according to the following criteria.

The evaluation results are shown in Table 3.

(Evaluation criteria)
A: Less than 0.05 B: 0.05 or more and less than 0.10 C: 0.10 or more and less than 0.20 D: 0.20 or more <Evaluation 2> Evaluation of toner coloring power As an electrophotographic image forming apparatus , A modified machine of a full-color copying machine (trade name: imageRUNNER ADVANCE C5255) manufactured by Canon Inc. was used, and the two-component developer 1 was put into the developer of the cyan station for evaluation.

The evaluation environment is a normal temperature and humidity environment (23 ° C, 50% RH), and the evaluation paper is plain paper for copying (trade name: GFC-081, A4 paper, basis weight: 81.4 g / m ² , Canon Marketing). (Sold by Japan Co., Ltd.) was used.

First, the relationship between the image density and the amount of toner on paper was investigated by changing the amount of toner on paper in a normal temperature and humidity environment.

Next, the image density of the FFH image (solid portion) was adjusted to 0.40, and the amount of toner loaded when the image density became 0.40 was determined.

From the toner loading amount (mg / cm ² ), the coloring power of the toner was evaluated according to the following criteria.

The evaluation results are shown in Table 3.

(Evaluation criteria)
A: Less than 0.35 B: 0.35 or more and less than 0.50 C: 0.50 or more and less than 0.65 D: 0.65 or more <Evaluation 3> Evaluation of toner brilliance The above image density is 0.40. Using the FFH image (solid portion), the ratio (A / B) of the reflectance A at the light receiving angle + 30 ° and the reflectance B at the light receiving angle -30 ° with respect to the incident light at the incident angle −45 ° was calculated. As the variable angle photometer, a spectroscopic variable angle color difference meter (trade name: GC5000L) manufactured by Nippon Denshoku Kogyo Co., Ltd. was used, and the wavelength was set to 470 nm.

The evaluation results are shown in Table 3.

(Evaluation criteria)
A: A / B is 70 or more and less than 80 B: A / B is 55 or more and less than 70 C: A / B is 40 or more and less than 55 D: A / B is less than 40 <Evaluation 4> Evaluation of fine line reproducibility The evaluation was based on the output of 500 images in a high temperature and high humidity environment (30 ° C, 80% RH), and then an image (print ratio: 4%) in which a grid pattern with a line width of 3 pixels was printed on the entire surface of A4 paper. It was output and the fine line reproducibility was evaluated according to the following evaluation criteria. The line width of 3 pixels is theoretically 127 μm. The line width of the image was measured with a microscope VK-8500 (manufactured by KEYENCE CORPORATION). When 5 points were randomly selected and the line width was measured and the average value of 3 points excluding the minimum value and the maximum value was d (μm), the following L was defined as the fine line reproducibility index.

L (μm) = | 127-d |
L defines the difference between the theoretical line width of 127 μm and the line width d on the output image. Since d may be larger than 127 or smaller than 127, it is defined as the absolute value of the difference. The smaller L is, the better the fine line reproducibility is shown.

The evaluation results are shown in Table 3.

(Evaluation criteria)
A: L is 0 μm or more and less than 10 μm B: L is 10 μm or more and less than 15 μm C: L is 15 μm or more and less than 20 μm D: L is 20 μm or more <Evaluation of two-component developer 2-18 and comparative two-component developer 1-4>
The evaluation of the two-component developer was carried out in the same manner as the evaluation of the two-component developer 1 except that the two-component developer 1 was changed to the two-component developer 2 to 19 and the comparative two-component developer 1 to 4.

The evaluation results are shown in Table 3.

1 Raw material fixed quantity supply means 2 Compressed gas flow rate adjusting means 3 Introductory pipe 4 Protruding member 5 Supply pipe 6 Processing room 7 Hot air supply means 8 Cold air supply means 9 Regulatory means 10 Recovery means 11 Hot air supply means outlet 12 Distributing member 13 Swirling member 14 Powder particle supply port

Claims (2)

A toner having toner particles containing a binder resin, aluminum fine particles, and silica fine particles.
The weight average particle size (D4) of the toner particles is 3.0 μm or more and 10.0 μm or less .
The toner particles contain the aluminum fine particles and the silica fine particles in a region inside 0.3 μm or more from the surface of the toner particles.
The content of the aluminum fine particles in the toner particles is 5.0 parts by mass or more and 30.0 parts by mass or less with respect to 100 parts by mass of the toner particles.
The content of the silica fine particles in the toner particles, Ri 0.1 part by weight to 2.5 parts by der respect to the toner particles 100 parts by weight,
The average aspect ratio (major axis / minor axis) of the silica fine particles is 1.0 or more and 1.2 or less, and the average D _50n of the major axis of the silica fine particles is 30 nm or more and 200 nm or less. Characteristic toner. The toner according to claim 1, wherein the average aspect ratio (major axis / minor axis) of the aluminum fine particles is 1.2 or more and 15 or less, and the average D _50n of the major axis of the aluminum fine particles is 200 nm or more and 400 nm or less.

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