JP7046703B2 - toner - Google Patents

Description

The present invention relates to a toner used in a recording method such as an electrophotographic method, an electrostatic recording method, a magnetic recording method, and a toner jet method.

The electrophotographic image forming apparatus is required to have high speed, long life, energy saving, and miniaturization, and in order to cope with these demands, further improvement of various performances is required. In particular, toner is required to further improve quality stability from the viewpoint of extending the service life. In particular, it is important that the quality does not change significantly in long-term durable use, and various toners and external additives have been proposed.
For example, Patent Document 1 discloses a technique of sharpening the main peak in the molecular weight distribution of toner, defining the peak molecular weight, and adding an azo iron compound. By controlling the molecular weight and full width at half maximum of the toner binder, the hardness of the toner is appropriately controlled, and by the presence of a azo iron compound, which is relatively hard among charge control agents, on the surface layer, stress resistance is improved. There is.
Further, Patent Document 2 discloses a toner in which a thermosetting resin is contained in a capsule material having a capsule film hardness of 1 N / m or more and less than 3 N / m for the purpose of obtaining a toner having an appropriate hardness. .. This improves the stress resistance in the cleaning section.
In Patent Document 3, by controlling the SrO / TiO ₂ (molar ratio) of strontium titanate particles having a polishing effect, in addition to preventing toner fusion due to the polishing effect, the environmental characteristics and charging of the toner We are proposing to improve the characteristics.

Japanese Unexamined Patent Publication No. 2016-170345 Japanese Unexamined Patent Publication No. 2015-141360 Patent No. 3648103

According to the techniques described in Patent Documents 1 and 2, a certain effect is confirmed on the stress resistance of the toner. Further, according to the technique described in Patent Document 3, a certain effect is confirmed on the improvement of the environmental characteristics and the charging characteristics of the toner. However, even when these techniques are used, it has been found that there is room for further improvement in terms of durability during long-term use.
Specifically, in long-term durable use, there may be a decrease in fluidity and chargeability that are considered to be derived from the embedding of an external additive. Alternatively, the external additive may be removed from the toner and transferred to the peripheral member, which may change the characteristics of the toner or contaminate the member. In particular, when strontium titanate is used as an external additive, excellent developability can be exhibited as an initial characteristic, but the polishing characteristics of strontium titanate may damage peripheral members such as a photosensitive drum. As a result, deterioration of solid uniformity and deterioration of image defects such as fog may occur.
In view of the above problems, it is an object of the present invention to provide a toner that suppresses damage to peripheral members such as a photosensitive drum and maintains excellent development characteristics even in long-term durable use.

The present invention is a toner containing toner particles and an external additive.
The external additive contains strontium titanate particles, and the strontium titanate particles have an average number of primary particles of 10 nm or more and 60 nm or less.
The strontium titanate particles are 39.700 ° ± 0.150 ° and 46.200 ° in the X-ray diffraction spectrum of CuKα obtained in the range where 2θ is 10 ° or more and 90 ° or less when the Bragg angle is θ. It has a peak in the range of ± 0.150 ° and has a peak.
When the area of the peak at 39.700 ° ± 0.150 ° is Sa and the area of the peak at 46.200 ° ± 0.150 ° is Sb, Sb / Sa is 1.80 or more and 2.30. Is below
The toner is characterized in that the Martens hardness when measured under the condition of a maximum load of 2.0 × 10 ^-4 N is 130 MPa or more and 1100 MPa or less.

According to the present invention, it is possible to provide a toner that suppresses damage to peripheral members such as a photosensitive drum and maintains excellent development characteristics even in long-term durable use.

It is a conceptual diagram which defines the surface layer thickness of the surface layer containing an organosilicon compound. It is a figure based on the transmission electron micrograph of the strontium titanate particle 1. It is explanatory drawing of the biaxial kneading extruder used for manufacturing the toner particle 29.

As described above, one of the means for controlling the environmental characteristics and charging characteristics of the toner is to use strontium titanate particles. The shape of the strontium titanate particles generally used as an external additive is a hexahedral shape, and many of them have a flat surface. When the strontium titanate particles have a flat surface, the contact area with the toner particles increases, so that the charge is easily transferred between the toner particles and the strontium titanate particles. Therefore, even if the toner particles are in a charge-up state due to triboelectric charging, the charge can be diffused to uniformly charge the toner particles. As a result, excellent developability can be exhibited from the initial stage of durability.

However, in the conventional strontium titanate particles, in long-term durability use, the strontium titanate particles may be transferred from the toner particles to the peripheral members due to rubbing in the developing machine, and the chargeability of the toner fluctuates at the end of the durability. , The developability tended to deteriorate. Alternatively, the transferred external additive particles may damage the surface of the photosensitive drum, resulting in deterioration of developability. The transition refers to a phenomenon in which the external additive moves from the toner particles to another toner particle or another member. That is, it means a phenomenon that the external additive does not stay on the toner particles. Further, even in a situation where the strontium titanate particles remain on the surface of the toner particles, the strontium titanate particles may be embedded in the surface of the toner particles or fine scratches may be generated on the surface of the toner particles. As a result, the fluidity and chargeability of the toner may be deteriorated, resulting in adverse image effects.

The present inventors have attempted to reduce the particle size of the strontium titanate particles in order to prevent the strontium titanate particles from migrating from the toner particles. It was thought that if the diameter was reduced, the migration could be suppressed even if it was repeatedly rubbed in the developing machine. It was thought that if the diameter was further reduced, it would be easier to roll on the surface of the toner particles, which would be effective for uniform charging of the toner. In fact, by reducing the particle size of the strontium titanate particles, the migration of the strontium titanate particles can be suppressed even if they are repeatedly rubbed in the developing machine during long-term durable use. However, depending on the developer configuration and usage conditions, the photosensitive drum and the surface of the toner particles may be damaged, or the strontium titanate particles may be buried in the surface of the toner particles. As a result, the fluidity and chargeability of the toner are deteriorated, which may cause image damage such as fog.

As a result of repeated studies, the present inventors have controlled the toner hardness to a specific range, and as an external agent, small particle size strontium titanate particles having a specific profile in the X-ray diffraction spectrum. We have found that it is possible to provide a toner that maintains excellent development characteristics by suppressing damage to peripheral members such as photosensitive drums and maintaining fluidity and chargeability even in long-term durable use. The present invention has been reached.

That is, the toner of the present invention is a toner containing toner particles and an external additive, the external agent contains strontium titanate particles, and the strontium titanate particles have an average number of primary particles. However, the strontium titanate particles are 10 nm or more and 60 nm or less, and the strontium titanate particles have 39.700 ° ± in the X-ray diffraction spectrum of CuKα obtained in the range where 2θ is 10 ° or more and 90 ° or less when the Bragg angle is θ. It has peaks in the range of 0.150 ° and 46.200 ° ± 0.150 °, and the area of the peak at 39.700 ° ± 0.150 ° is Sa, and the 46.200 ° ± 0.150. When the peak area at ° is Sb, Sb / Sa is 1.80 or more and 2.30 or less, and the Martens hardness when measured under the condition of the maximum load of the toner of 2.0 × 10-4N is determined. It is a toner characterized by being 130 MPa or more and 1100 MPa or less.

The strontium titanate particles of the present invention have 39.700 ° ± 0.150 ° and 46. In the X-ray diffraction spectrum of CuKα obtained in the range where 2θ is 10 ° or more and 90 ° or less when the Bragg angle is θ. It has a peak in the range of 200 ° ± 0.150 °. Strontium titanate with a peak at this position has a perovskite structure belonging to the cubic system, and the peaks at 39.700 ° ± 0.150 ° and 46.200 ° ± 0.150 ° are the Miller index (111) and (, respectively. It is a diffraction peak derived from the lattice plane of 200). Generally, particles belonging to the cubic system tend to have a hexahedral shape as the appearance shape of the particles, and strontium titanate particles also have (100) planes and (200) planes corresponding to the plane direction of the hexahedral shape in the manufacturing process. grow up.

However, as a result of our studies, we have found that strontium titanate particles having a hexahedral (200) plane in the plane direction and a (111) plane in the apex direction show good characteristics.

As a result of detailed examination, when the area of the peak of 39.700 ° ± 0.150 ° is Sa and the area of the peak of 46.200 ° ± 0.150 ° is Sb, Sb / Sa is 1. It was found that a remarkable effect was exhibited when the content was .80 or more and 2.30 or less. Further, the Sb / Sa is preferably 1.80 or more and 2.25 or less.

The number average particle size of the primary particles of the strontium titanate particles of the present invention is 10 nm or more and 60 nm or less. Further, the number average particle size is preferably 10 nm or more and 50 nm or less.

When the Sb / Sa and the number average particle diameter are in the above range, the migration of strontium titanate particles from the toner particles can be suppressed. As a result, it is possible to suppress the occurrence of drum scratches and the deterioration of toner chargeability and fluidity.

The number average particle size of the primary particles of the strontium titanate particles and Sb / Sa can be controlled by adjusting the molar ratio of the raw material of the strontium titanate particles and the production conditions.

The Sr / Ti (molar ratio) of the strontium titanate particles is preferably 0.70 or more and 0.85 or less, and more preferably 0.75 or more and 0.83 or less. When Sr / Ti (molar ratio) is in the above range, the proportion of Ti that is close to negative chargeability in terms of charge increases, so that the charge distribution tends to be sharp and the occurrence of fog in the latter half of durability is suppressed. .. Sr / Ti (molar ratio) can be controlled by adjusting the molar ratio of the raw material of the strontium titanate particles and the production conditions.

The average circularity of the primary particles of the strontium titanate particles is preferably 0.700 or more and 0.920 or less, and more preferably 0.790 or more and 0.920 or less.

When the average circularity is in the above range, the strontium titanate particles are likely to be crushed on the toner particles, and the coverage by the strontium titanate particles is likely to increase. As a result, the charge of the toner is likely to rise from the initial stage of durability, and it is easy to obtain the effect on the developability and the suppression of fog at the initial stage of durability. The average circularity of the primary particles of strontium titanate particles can be controlled by adjusting the production conditions.

The strontium titanate particles preferably have a methanol concentration of 60% by volume or more and 95% by volume or less when the transmittance of light having a wavelength of 780 nm is 50% in a wettability test with a mixed solvent of methanol / water, and 65 volumes. More preferably, it is% or more and 95% by volume or less. When the methanol concentration is in the above range, the developability after being left in a high temperature and high humidity environment is easily maintained.

The wettability of the strontium titanate particles to the methanol / water mixed solvent can be controlled by adjusting the surface treatment conditions of the strontium titanate particles.

The coverage of the surface of the toner particles with strontium titanate particles, which is determined by an X-ray photoelectron spectrometer (ESCA), is preferably 5.0 area% or more and 20.0 area% or less, and is 8.0 area% or more and 20. More preferably, it is 0.0 area% or less.

When the coverage is in the above range, the toner is likely to be charged from the initial stage of durability, and it is easy to obtain an effect on the developability and the suppression of fog at the initial stage of durability. The coverage can be controlled by adjusting the shape and amount of the strontium titanate particles added, the production conditions, and the properties of the toner particles.

In order to produce perovskite-type strontium titanate particles, it is preferable to use a normal pressure heating reaction method in which the particles are reacted at normal pressure instead of hydrothermal treatment using a pressure vessel.

A mineral acid defoliaceate, which is a hydrolyzate of a titanium compound, is used as a titanium oxide source, and a water-soluble acidic compound is used as a strontium source. Then, a method of reacting the mixed solution with an alkaline aqueous solution at 60 ° C. or higher while adding it, and then treating with an acid can be exemplified.

Further, as a method of controlling the shape of the strontium titanate particles, there is also a method of applying a dry mechanical treatment.

Hereinafter, the normal pressure heating reaction method will be described.

As the titanium oxide source, it is preferable to use a mineral acid defoliated product of a hydrolyzate of a titanium compound. Preferably, the pH of metatitanic acid having an SO ₃ content of 1.0% by mass or less, more preferably 0.5% by mass or less obtained by a sulfuric acid method is adjusted to 0.8 or more and 1.5% or less with hydrochloric acid. Use the one that has been deflated. This makes it possible to obtain strontium titanate fine particles having a good particle size distribution.

On the other hand, as the strontium source, strontium nitrate, strontium chloride, or the like can be used. As the alkaline aqueous solution, caustic alkali can be used, but the sodium hydroxide aqueous solution is particularly preferable.

Factors that affect the particle size of the obtained strontium titanate particles in the production method include the mixing ratio of the titanium oxide source and the strontium source, the concentration of the titanium oxide source at the initial stage of the reaction, the temperature at which the alkaline aqueous solution is added, and the addition. Speed etc. can be mentioned. These factors can be appropriately adjusted to obtain strontium titanate particles having a desired particle size and particle size distribution. In addition, in order to prevent the formation of strontium carbonate in the reaction process, it is preferable to prevent the mixing of carbon dioxide gas by reacting in a nitrogen gas atmosphere.

The mixing ratio of the titanium oxide source and the strontium source at the time of the reaction is preferably 0.90 or more and 1.40 or less, and more preferably 1.05 or more and 1.20 or less in terms of Sr / Ti (molar ratio). .. The strontium source has high solubility in water, while the titanium oxide source has low solubility in water, but when Sr / Ti (molar ratio) is 0.90 or more, the residual unreacted titanium oxide is suppressed. Be done.

The concentration of the titanium oxide source at the initial stage of the reaction is preferably 0.050 mol / L or more and 1.300 mol / L or less, and more preferably 0.080 mol / L or more and 1.200 mol / L as TiO ₂ . It is as follows. By increasing the concentration of the titanium oxide source at the initial stage of the reaction, the number average particle size of the primary particles of the strontium titanate particles can be reduced.

The higher the temperature at which the alkaline aqueous solution is added, the better the crystallinity of the product can be obtained. Is appropriate.

As for the addition rate of the alkaline aqueous solution, the slower the addition rate, the larger the strontium titanate particles can be obtained, and the faster the addition rate, the smaller the strontium titanate particles can be obtained. The addition rate of the alkaline aqueous solution is preferably 0.001 equivalent / h or more and 1.2 equivalent / h or less, and more preferably 0.002 equivalent / h or more and 1.1 equivalent / h or less with respect to the charged raw material. Is. These can be appropriately adjusted according to the particle size to be obtained.

Next, the acid treatment will be described. When the mixing ratio of the titanium oxide source and the strontium source exceeds 1.40 in Sr / Ti (molar ratio), the unreacted strontium source remaining after the reaction is completed reacts with the carbon dioxide gas in the air to form strontium carbonate. It produces impurities such as, and tends to widen the particle size distribution. Further, if impurities such as strontium carbonate remain on the surface, it becomes difficult to uniformly coat the surface treatment agent due to the influence of the impurities when performing the surface treatment for imparting hydrophobicity. Therefore, after adding the alkaline aqueous solution, it is advisable to carry out acid treatment in order to remove the unreacted strontium source.

In the acid treatment, it is preferable to adjust the pH to 2.5 or more and 7.0 or less using hydrochloric acid, and more preferably to adjust the pH to 4.5 or more and 6.0 or less. As the acid, nitric acid, acetic acid and the like can be used for the acid treatment in addition to hydrochloric acid. However, when sulfuric acid is used, strontium sulfate, which has low water solubility, is likely to be generated.

Next, shape control will be described. In order to obtain the shape of the strontium titanate particles, a dry mechanical treatment may be given as an example.

For example, a hybridizer (manufactured by Nara Machinery Co., Ltd.), Nobilta (manufactured by Hosokawa Micron Co., Ltd.), Mechanofusion (manufactured by Hosokawa Micron Co., Ltd.), High Flex Gural (manufactured by EarthTechnica Co., Ltd.) and the like can be used. By treating the strontium titanate particles with these devices, Sb / Sa can be adjusted to 1.80 or more and 2.30 or less.

When controlling the shape of strontium titanate particles by mechanical treatment, fine particles of strontium titanate particles may be generated. In order to remove the fine powder, it is preferable to carry out an acid treatment after the mechanical treatment. In the acid treatment, it is preferable to adjust the pH to 0.1 or more and 5.0 or less using hydrochloric acid. As the acid, nitric acid, acetic acid and the like can be used for the acid treatment in addition to hydrochloric acid. It is preferable that the mechanical treatment for controlling the shape of the strontium titanate particles is performed before the surface treatment of the strontium titanate particles is performed.

Strontium titanate particles are hydrophobic such as inorganic oxides such as SiO ₂ , Al ₂ O ₃ , titanium coupling agents, silane coupling agents, silicone oils, and fatty acid metal salts for charge adjustment and improvement of environmental stability. Surface treatment with an agent is recommended. A functional group such as an amino group or fluorine may be introduced into the coupling agent.

Examples of the fatty acid metal salt include zinc stearate, sodium stearate, calcium stearate, zinc laurate, aluminum stearate, magnesium stearate and the like. Similar effects can be obtained with stearic acid, which is a fatty acid.

Examples of the surface treatment method include a wet method in which a hydrophobic agent is dissolved or dispersed in a solvent, strontium titanate particles are added thereto, and the solvent is removed while stirring. Further, a dry method may be used in which the treatment agent and the strontium titanate particles are directly mixed and treated while stirring.

The content of the strontium titanate particles is preferably 0.05 parts by mass or more and 5.0 parts by mass or less, and 0.1 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the toner particles. Is more preferable.

Methods for measuring various physical properties of strontium titanate will be described below.

The physical properties of strontium titanate particles are measured using toner as a sample.

When measuring the physical properties of the strontium titanate particles or the toner particles from the toner to which the strontium titanate particles are externally attached, the strontium titanate particles or other external additives may be separated from the toner for measurement.

The toner is ultrasonically dispersed in methanol to separate strontium titanate particles and other external additives, and the mixture is allowed to stand for 24 hours. Toner particles can be isolated by separating and recovering the precipitated toner particles and the strontium titanate particles and other external additives dispersed in the supernatant, and sufficiently drying them. In addition, strontium titanate particles can be isolated by treating the supernatant liquid by centrifugation.

<Measurement of average particle size of primary particles of strontium titanate particles>
The number average particle size of the primary particles of strontium titanate particles is measured using a transmission electron microscope "JEM-2800" (JEOL Ltd.).

Observe the toner externally attached with strontium titanate particles, and randomly measure the major axis of 100 primary particles of strontium titanate particles in a field magnified up to 200,000 times to obtain the average particle size. .. The observation magnification may be appropriately adjusted according to the size of the strontium titanate particles.

<Measurement of diffraction peak of strontium titanate particles>
For the diffraction peak of the strontium titanate particles, a powder X-ray diffractometer "SmartLab" (manufactured by Rigaku Co., Ltd., sample horizontal strong X-ray diffractometer) is used.

Further, the calculation of Sb / Sa from the obtained peak uses "PDXL2 (version 2.2.2.0)" of the analysis software attached to the above apparatus.

As the measurement sample, toner or strontium titanate particles isolated from the toner are used, and the measurement is performed by the following procedure. In the following examples, the produced strontium titanate particles are also measured.

(Preparation of sample)
The measurement sample is measured after being uniformly placed in a 0.5 mm diameter Boro-Silicate capillary (manufactured by W. Muller).

(Measurement condition)
・ Tube: Cu
-Optical system: CBO-E
・ Sample table: Capillary sample table ・ Detector: D / tex Ultra250 detector ・ Voltage: 45kV
・ Current: 200mA
・ Starting angle: 10 °
・ End angle: 90 °
・ Sampling width: 0.02 °
・ Speed measurement time setting value: 10
・ IS: 1mm
・ RS1: 20mm
・ RS2: 20mm
・ Attenuator: Open
・ Capillary rotation speed setting value: 100

For other conditions, the default values of the device are used.

(analysis)
First, the obtained peak is subjected to peak separation processing using the software "PDXL2" attached to the apparatus. The peak separation is obtained by executing the optimization using the "divided Voigt function" that can be selected by PDXL, and the value of the obtained integrated intensity is used.

This determines the 2θ value of the diffraction peak top and its area. Sb / Sa is calculated from the peak area of a predetermined 2θ value. At this time, if the calculation result of the peak separation and the measured spectrum are significantly different from each other, processing such as manually setting the baseline is performed to adjust so that the calculated result and the actually measured spectrum match.

<Measurement of Sr / Ti (molar ratio) of strontium titanate particles>
The Sr and Ti contents of the strontium titanate particles are measured using a wavelength dispersive fluorescent X-ray analyzer (Axios advanced, manufactured by PANalytical).

1 g of a sample is weighed on a cup for powder measurement recommended by PANalytical and a special film is attached, and the elements from Na to U in the strontium titanate particles are measured by the FP method under an atmospheric pressure He atmosphere.

At that time, assuming that all the detected elements are oxides, and assuming that the total mass of them is 100%, the content (% by mass) of SrO and TiO ₂ with respect to the total mass by software SpectraEvolution (version 5.0L). Is calculated as an oxide conversion value.

After that, Sr / Ti (mass ratio) obtained by removing oxygen from the quantification result is obtained, and then converted into Sr / Ti (molar ratio) from the atomic weight of each element.

As the sample, strontium titanate particles isolated from the toner are used. Further, in the following examples, the produced strontium titanate particles are also measured.

<Measurement of average circularity of primary particles of strontium titanate particles>
The average circularity of the primary particles of strontium titanate particles is measured using a transmission electron microscope "JEM-2800" (JEOL Ltd.).

Observe the toner externally attached with strontium titanate particles and calculate as follows.

The observation magnification is appropriately adjusted according to the size of the strontium titanate particles.

Using the image processing software "Image-Pro Plus 5.1J" (manufactured by Media Cybernetics), the circle-equivalent diameter of 100 strontium titanate particles and the circumference of the particles are randomly measured in a field magnified up to 200,000 times. Then, the average circularity is calculated. The equivalent circle diameter is the diameter of a circle having the same area as the projected area of the particles.

The circularity is calculated by the following formula, and the arithmetic mean value is used as the average circularity.
(Equation) Circularity = equivalent circle diameter x 3.14 / perimeter of particles

Confirmation that the external additive is strontium titanate is carried out by STEM-EDS measurement.

The measurement conditions are as follows.
JEM2800 type transmission electron microscope: Acceleration voltage 200kV
EDS detector: JED-2300T (JEOL, element area 100mm ² )
EDS Analyzer: Noran System7 (Thermo Fisher Scientific)
X-ray storage rate: 10,000 to 15,000 cps
Dead time: Adjust the electron dose to 20 to 30%, and perform EDS analysis (total number of times 100 times or measurement time 5 min).

<Measurement of strontium titanate particle hydrophobicity (% by volume)>
The degree of hydrophobicity (% by volume) of the strontium titanate particles is measured by a powder wettability tester "WET-100P" (manufactured by Reska).

A fluororesin-coated spindle-shaped rotor with a length of 25 mm and a maximum body diameter of 8 mm is placed in a cylindrical glass container having a diameter of 5 cm and a thickness of 1.75 mm.

70 mL of a hydrous methanol solution consisting of 50% by volume of methanol and 50% by volume of water is placed in the cylindrical glass container. Then, 0.5 g of strontium titanate particles isolated from the toner is added and set in a powder wettability tester.

Using a magnetic stirrer, methanol is added to the liquid at a rate of 0.8 mL / min through the powder wettability tester while stirring at a rate of 200 rpm.

The transmittance is measured with light having a wavelength of 780 nm, and the value represented by the volume percentage of methanol when the transmittance reaches 50% (= (volume of methanol / volume of mixture) × 100) is defined as the degree of hydrophobicity. .. The volume ratio of initial methanol to water is adjusted as appropriate according to the degree of hydrophobicity of the sample. Further, in the following examples, the produced strontium titanate particles are also measured.

<Measurement of coverage with strontium titanate particles on the toner surface>
The coverage of the toner surface with strontium titanate particles is calculated from the following formula (2) by measuring the toner under the following conditions.
-Measuring device: X-ray photoelectron spectroscope: Quantum2000 (manufactured by ULVACFY Co., Ltd.)
・ X-ray source: Monochrome Al Kα
-Xray Setting: 100 μmφ (25W (15KV))
・ Photoelectron extraction angle: 45 degrees ・ Neutralization condition: Combined use of neutralization gun and ion gun ・ Analysis area: 300 × 200 μm
-Pass Energy: 58.70eV
-Step size: 0.125 eV
・ Analysis software: Maltipak (PHI)

Here, the peak of Ti 2p (BE 452 to 468eV) is used for calculating the quantitative value of the Ti atom. Let Z1 be the quantitative value of the Ti element obtained here.

Next, elemental analysis of the strontium titanate particles alone is performed in the same manner as in the above elemental analysis, and the quantitative value of the Ti element obtained here is defined as Z2. The coverage of the toner surface with strontium titanate particles is calculated by the following formula (2).
Coverage = Z1 / Z2 × 100 (2)

The toner of the present invention has a Martens hardness of 130 MPa or more and 1100 MPa or less when measured under the condition of a maximum load of 2.0 × 10 ^-4 N.

Hardness is one of the mechanical properties of the surface or the vicinity of the surface of an object, and is the difficulty of deforming or scratching the object when it is about to be deformed or scratched by a foreign substance. There are various measurement methods and definitions. For example, the measurement method is often used according to the size of the measurement area, such as the Vickers method when the measurement area is 10 μm or more, the nanoindentation method when the measurement area is 10 μm or less, and AFM when the measurement area is 1 μm or less. .. As a definition, for example, Brinell hardness and Vickers hardness are used as the indentation hardness, Martens hardness is used as the scratch hardness, and shore hardness is used as the repulsion hardness. In the measurement of toner, the nanoindentation method is preferably used because the general particle size is 3 μm to 10 μm.

In the present invention, by controlling the maltens hardness of the toner within the above-mentioned range, it is possible to prevent scratches on the surface of the toner particles and the burial of an external additive that may be caused by the scratches, and to maintain excellent development characteristics even in long-term durable use. Found that we can provide.

When the Martens hardness is lower than 130 MPa, the effect of the present invention cannot be obtained satisfactorily. A preferable value is 200 MPa or more, and a more preferable value is 250 MPa or more.

On the other hand, if the Martens hardness is higher than 1100 MPa, it may cause damage to members such as the regulating blade and the developing roller in some cases, so care must be taken. A preferable value is 1000 MPa or less, and a more preferable value is 900 MPa or less.

The method of measuring the maltens hardness of the toner by the nanoindentation method is calculated from the obtained load-displacement curve according to the procedure of the indentation test specified in ISO14577-1 with a commercially available ISO14577-1 compliant device. be able to. In the present invention, an ultrafine indentation hardness tester "ENT-1100b" (manufactured by Elionix Inc.) was used as an apparatus conforming to the ISO standard. The measuring method is described in the "ENT1100 Operation Manual" attached to the device, and the specific measuring method is as follows.

The measurement environment was maintained at 30.0 ° C. inside the shield case with the attached temperature control device. Keeping the atmospheric temperature constant is effective in reducing variations in measured data due to thermal expansion and drift. The set temperature was set to 30.0 ° C., assuming the temperature near the developing machine where the toner is rubbed. For the sample table, the standard sample table attached to the device was used, and after applying the toner, weak air was blown so that the toner was dispersed, and the sample table was set on the device and held for 1 hour or more before measurement. ..

The indenter was measured using a flat indenter (titanium indenter, tip made of diamond), which was attached to the device and had a flat tip of 20 μm square. For small-diameter and spherical objects such as toner, objects with external additives attached, and objects with irregularities on the surface, flat indenters are used because sharp indenters have a large effect on measurement accuracy. The maximum load of the test is set to 2.0 × 10 ^-4 N. By setting this test load, it is possible to measure the hardness without destroying the surface layer of the toner under the condition corresponding to the stress received by one toner grain in the developing unit. In the present invention, since abrasion resistance is important, it is important to measure the hardness while maintaining the surface layer without breaking it.

As the particles to be measured, those in which toner is present alone on the measurement screen (field size: width 160 μm, height 120 μm) by the microscope attached to the apparatus are selected. However, in order to eliminate the error of the displacement amount as much as possible, select one having a particle diameter (D) within the range of ± 0.5 μm of the number average particle diameter (D1) (D1-0.5 μm ≦ D ≦ D1 + 0.5 μm). .. For the particle size measurement of the particles to be measured, the major axis and the minor axis of the toner were measured using the software attached to the device, and [(major axis + minor axis) / 2] was defined as the particle diameter D (μm). Further, the number average particle size is measured by a method described later by "Coulter Counter Multisizer 3 (manufactured by Beckman Coulter Co., Ltd.).

At the time of measurement, 100 arbitrary toner particles having a particle diameter D (μm) satisfying the above conditions are selected and measured. The conditions to be input at the time of measurement are as follows.
Test mode: Load-unloading test Test load: 20.000 mgf (= 2.0 × 10 ^-4 N)
Number of divisions: 1000 steps
Step interval: 10msec

When the measurement is performed by selecting the analysis menu "Data analysis (ISO)", the Martens hardness is analyzed and output by the software attached to the device after the measurement. The above measurement was performed on 100 toner particles, and the arithmetic mean value thereof was taken as the Martens hardness in the present invention.

Further, the toner of the present invention preferably has a maltens hardness of 5 MPa or more and 100 MPa or less, and more preferably 10 MPa or more and 80 MPa or less, as measured under the condition of a maximum load of 9.8 × 10 ^-4 N. This 9.8 × 10 ^-4 N load is considered to correspond to the share received by the cleaning section, and if the Martens hardness under this load is within the above range, the cleaning section will have appropriate softness and will cause drum scratches. Occurrence is suppressed. That is, the toner is hard for the share corresponding to the developing section and has appropriate softness for the share corresponding to the cleaning section.

Since the conventional toner is a technical idea that can withstand a large share, when trying to secure the hardness that can withstand development, the hardness may inevitably become a problem in the cleaning part and the fixing part. The toner of the present invention can have an appropriate hardness according to the share received in each process. When the maltens hardness measured under the condition of the maximum load of 9.8 × 10 ^-4 N is 5 MPa or more, the toner is not easily crushed by the cleaning blade, so that the blade is not easily fused and cleaning failure is unlikely to occur. On the other hand, when it is 100 MPa or less, the hardness is appropriate, so that the occurrence of drum scratches can be suppressed.

In the measurement of Martens hardness measured under the condition of maximum load 9.8 × 10 ^-4 N, the test load was 9.8 × 10 in the measurement method under the condition of maximum load 2.0 × 10 ^-4 N. Set to ^-4 N and measure.

The Martens hardness measured under the condition of a maximum load of 9.8 × 10 ^-4 N can be controlled by the molecular weight of the binder resin contained in the toner, the glass transition temperature Tg, the cross-linking design, and the like.

The means for adjusting the Martens hardness when measured under the condition of a maximum load of 2.0 × 10 ^-4 N to 130 MPa or more and 1100 MPa or less is not particularly limited. However, since the hardness is significantly harder than the hardness of the organic resin used for general toner, it is difficult to achieve it by the means usually used for increasing the hardness. For example, it is difficult to achieve by means for designing a resin having a high glass transition temperature, means for increasing the molecular weight of the resin, means for thermosetting, means for adding a filler to the surface layer, and the like.

The Martens hardness of the organic resin used for general toner is about 50 MPa or more and 80 MPa or less when measured under the condition of a maximum load of 2.0 × 10 ^-4 N. Further, even when the hardness is increased by increasing the resin design or the molecular weight, the hardness is about 120 MPa or less, and the toner of the present invention is significantly harder than the general toner.

As one means for adjusting to the above-mentioned specific hardness range, for example, the surface layer of the toner is formed of a substance such as an inorganic substance having an appropriate hardness, and the chemical structure and the macrostructure thereof are controlled so as to have an appropriate hardness. There is a way to do it.

As a specific example, an organosilicon polymer can be mentioned as a substance having the above-mentioned specific hardness, and as a material selection, the number of carbon atoms directly bonded to the silicon atom of the organosilicon polymer, the carbon chain length, etc. It is possible to adjust the hardness by. The toner particles have a surface layer containing an organosilicon polymer, and the number of carbon atoms directly bonded to the silicon atoms of the organosilicon polymer is 1 or more and 3 or less (preferably 1 or more and 2 or less). , More preferably one), because it is easy to adjust to the above-mentioned specific hardness.

As a means for adjusting the Martens hardness by the chemical structure, it is possible to adjust the chemical structure such as cross-linking of the surface layer material and the degree of polymerization. As a means for adjusting the Martens hardness by the macro structure, it is possible to adjust the uneven shape of the surface layer or the network structure connecting the irregularities. When the organosilicon polymer is used as the surface layer, these adjustments can be made by adjusting the pH, concentration, temperature, time, etc. when the organosilicon polymer is pretreated. Further, it can be adjusted by adjusting the timing, form, concentration, reaction temperature, etc. of the surface layer of the organosilicon polymer on the core particles of the toner.

The following method is particularly preferable in the present invention. First, core particles of a toner containing a binder resin and a colorant are produced and dispersed in an aqueous medium to obtain a core particle dispersion liquid. The concentration at this time is preferably such that the solid content of the core particles is 10% by mass or more and 40% by mass or less with respect to the total amount of the core particle dispersion liquid. The temperature of the core particle dispersion is preferably adjusted to 35 ° C. or higher. Further, it is preferable to adjust the pH of the core particle dispersion to a pH at which condensation of the organosilicon compound does not easily proceed. Since the pH at which condensation of the organosilicon polymer is difficult to proceed differs depending on the substance, it is preferably within ± 0.5, centering on the pH at which the reaction is most difficult to proceed.

On the other hand, it is preferable to use an organosilicon compound that has been hydrolyzed. For example, it is hydrolyzed in a separate container as a pretreatment for the organosilicon compound. When the amount of the organic silicon compound is 100 parts by mass, the concentration of hydrolysis is preferably 40 parts by mass or more and 500 parts by mass or less of water from which ions have been removed such as ion-exchanged water and RO water, and more preferably 100 parts by mass of water. It is 400 parts by mass or less. The conditions for hydrolysis are preferably pH 2 to 7, temperature 15 to 80 ° C., and time 30 to 600 minutes.

The obtained hydrolyzate and the core particle dispersion are mixed and adjusted to a pH suitable for condensation (preferably 6 to 12, or 1 to 3, more preferably 8 to 12) to obtain an organosilicon compound. The surface layer can be attached to the surface of the core particles of the toner while being condensed. Condensation and surface layering are preferably carried out at 35 ° C. or higher for 60 minutes or longer. Further, the macrostructure of the surface can be adjusted by adjusting the holding time at 35 ° C. or higher before adjusting the pH to a pH suitable for condensation, but if the time is too long, the toner having the Martens hardness of the present invention can be obtained. Since it is difficult, it is preferably 3 minutes or more and 120 minutes or less.

Since the reaction residue can be reduced by the above means, unevenness can be formed on the surface layer, and a network structure can be formed between the convexities, it is easy to obtain the toner having the above-mentioned specific maltens hardness. ..

When a surface layer containing an organosilicon polymer is used, the fixation rate of the organosilicon polymer is preferably 90% or more and 100% or less. More preferably, it is 95% or more. If the fixing rate is within this range, the change in Martens hardness during durable use is small, and charging can be maintained. The method for measuring the adhesion rate of the organosilicon polymer will be described later.

[About the surface layer]
When the toner particles have a surface layer, the surface layer is a layer that covers the toner core particles and exists on the outermost surface of the toner particles. The surface layer containing the organosilicon polymer is much harder than the conventional toner particles. Therefore, from the viewpoint of fixability, it is also preferable to provide a portion where the surface layer is not formed on a part of the surface of the toner particles.

However, the ratio of the number of divided shafts having a surface layer thickness of 2.5 nm or less containing the organosilicon polymer (hereinafter, also referred to as a ratio of the surface layer thickness of 2.5 nm or less) is 20.0% or less. Is preferable. When this condition is satisfied, the surface layer containing the organosilicon polymer sufficiently covers the core surface. More preferably, it is 10.0% or less. The measurement can be specified by cross-sectional observation using a transmission electron microscope (TEM), but the details will be described later.

[About the surface layer containing an organosilicon polymer]
When the toner particles have a surface layer containing an organosilicon polymer, it preferably has a partial structure represented by the formula (1).
R-SiO _3/2 formula (1)
(R indicates a hydrocarbon group having 1 or more carbon atoms and 6 or less carbon atoms.)

In the organosilicon polymer having the structure of the formula (1), one of the four valences of the Si atom is bonded to R and the remaining three are bonded to O atom. The O atom constitutes a state in which both of the two valences are bonded to Si, that is, a siloxane bond (Si—O—Si). Considering the Si atom and the O atom as the organosilicon polymer, since two Si atoms have three O atoms, it is expressed as −SiO _3/2 . It is considered that the −SiO _3/2 structure of this organosilicon polymer has properties similar to those of silica (SiO ₂ ) composed of a large number of siloxane bonds. Therefore, it is considered possible to increase the Martens hardness because the structure is closer to that of an inorganic substance as compared with the toner formed on the surface layer by the conventional organic resin.

Furthermore, in the chart obtained by measuring ²⁹ Si-NMR of the insoluble content of tetrahydrofuran (THF) of the toner particles, the ratio of the peak area attributed to the structure of the formula (1) to the total peak area of the organic silicon polymer is 20%. The above is preferable. The detailed measurement method will be described later, but this approximates that the organosilicon polymer contained in the toner particles has a partial structure represented by R-SiO _3/2 of 20% or more. ..

As described above, it is the meaning of the partial structure of −SiO _3/2 that three of the four valences of the Si atom are bonded to the oxygen atom and the oxygen atom is further bonded to another Si atom. If one of the oxygens is a silanol group, the partial structure of the organosilicon polymer is represented by R—SiO _{2 / 2} -OH. Further, if the two oxygens are silanol groups, the partial structure thereof is R—SiO _1/2 (−OH) ₂ . Comparing these structures, it is closer to the silica structure represented by SiO ₂ that more oxygen atoms form a crosslinked structure with Si atoms. Therefore, the more the −SiO _3/2 skeleton is, the lower the surface free energy of the surface of the toner particles can be, which is excellent in environmental stability and stain resistance.

Further, due to the durability due to the partial structure represented by the formula (1) and the hydrophobicity and chargeability of R in the formula (1), the low molecular weight (Mw1000 or less) existing inside the surface layer and easily exuding. Bleeding of the resin, the resin having a low Tg (40 ° C. or less), and in some cases, the release agent can be suppressed.

The ratio of the peak area of the partial structure represented by the formula (1) is the type and amount of the organosilicon compound used for forming the organosilicon polymer, and the hydrolysis, addition polymerization and condensation polymerization during the formation of the organosilicon polymer. It can be controlled by the reaction temperature, reaction time, reaction solvent and pH.

In the partial structure represented by the formula (1), R is preferably a hydrocarbon group having 1 or more and 6 or less carbon atoms. This makes it easy to stabilize the amount of charge. In particular, an aliphatic hydrocarbon group or a phenyl group having 1 or more and 5 or less carbon atoms, which is excellent in environmental stability, is preferable.

In the present invention, it is more preferable that the R is an aliphatic hydrocarbon group having 1 or more and 3 or less carbon atoms in order to further improve the chargeability and the prevention of fog. When the chargeability is good, the transferability is good and the transfer residual toner is small, so that the contamination of the drum, the charging member, and the transfer member is improved.

As the aliphatic hydrocarbon group having 1 or more and 3 or less carbon atoms, a methyl group, an ethyl group, a propyl group or a vinyl group can be preferably exemplified. From the viewpoint of environmental stability and storage stability, R is more preferably a methyl group.

As an example of producing an organosilicon polymer, the sol-gel method is preferable. The sol-gel method is a method in which a liquid raw material is used as a starting material, hydrolyzed and condensed polymerized, and gelled through a sol state, and is used in a method for synthesizing glass, ceramics, organic-inorganic hybrids, and nanocomposites. By using this production method, functional materials having various shapes such as a surface layer, a fiber, a bulk body, and fine particles can be produced from a liquid phase at a low temperature.

Specifically, the organosilicon polymer present on the surface layer of the toner particles is preferably produced by hydrolysis and polycondensation of a silicon compound typified by alkoxysilane.

By providing the surface layer containing the organosilicon polymer on the toner particles, it is possible to obtain a toner having improved environmental stability, less likely to deteriorate the performance of the toner during long-term use, and excellent storage stability. ..

Furthermore, since the sol-gel method starts from a liquid and gels the liquid to form a material, various microstructures and shapes can be created. In particular, when the toner particles are produced in an aqueous medium, the hydrophilicity of the hydrophilic groups such as the silanol group of the organosilicon compound facilitates precipitation on the surface of the toner particles. The microstructure and shape can be adjusted according to the reaction temperature, reaction time, reaction solvent, pH, type and amount of organometallic compound, and the like.

The organosilicon polymer on the surface layer of the toner particles is preferably a polycondensation polymer of an organosilicon compound having a structure represented by the following formula (Z).

（式（Ｚ）中、Ｒ₁は、炭素数１以上６以下の炭化水素基を表し、Ｒ₂、Ｒ₃及びＲ₄は、それぞれ独立して、ハロゲン原子、ヒドロキシ基、アセトキシ基、又は、アルコキシ基を表す。）

(In the formula (Z), R ₁ represents a hydrocarbon group having 1 or more carbon atoms and 6 or less carbon atoms, and R ₂ , R ₃ and R ₄ are independently halogen atoms, hydroxy groups, acetoxy groups, or Represents an alkoxy group.)

Hydrophobicity can be improved by the hydrocarbon group (preferably an alkyl group) of R ₁ , and toner particles having excellent environmental stability can be obtained. Further, as the hydrocarbon group, an aryl group which is an aromatic hydrocarbon group, for example, a phenyl group can also be used. When the hydrophobicity of R ₁ is large, the charge amount fluctuates greatly in various environments. Therefore, in view of environmental stability, R ₁ is preferably a hydrocarbon group having 1 or more carbon atoms and 3 or less carbon atoms. It is more preferably a methyl group.

R ₂ , R ₃ and R ₄ are independently halogen atoms, hydroxy groups, acetoxy groups, or alkoxy groups (hereinafter, also referred to as reactive groups). These reactive groups are hydrolyzed, addition polymerized and polycondensed to form a crosslinked structure, and a toner having excellent resistance to member contamination and development durability can be obtained. The hydrolyzability is mild at room temperature, and from the viewpoint of precipitation on the surface of the toner particles and coating property, an alkoxy group having 1 to 3 carbon atoms is preferable, and a methoxy group or an ethoxy group is more preferable. .. Further, the hydrolysis, addition polymerization and condensation polymerization of R ₂ , R ₃ and R ₄ can be controlled by the reaction temperature, reaction time, reaction solvent and pH.

In order to obtain the organosilicon polymer used in the present invention, an organosilicon compound having three reactive groups (R ₂ , R ₃ and R ₄ ) in one molecule other than R ₁ in the above formula (Z) is obtained. (Hereinafter, also referred to as trifunctional silane) may be used alone or in combination of two or more.

Examples of the above formula (Z) include the following.

Methyltrimethoxysilane, Methyltriethoxysilane, Methyldiethoxymethoxysilane, Methylethoxydimethoxysilane, Methyltrichlorosilane, Methylmethoxydichlorosilane, Methylethoxydichlorosilane, Methyldimethoxychlorosilane, Methylmethoxyethoxychlorosilane, Methyldiethoxychlorosilane, Methyl Triacetoxysilane, Methyldiacetoxymethoxysilane, Methyldiacetoxyethoxysilane, Methylacetoxydimethoxysilane, Methylacetoxymethoxyethoxysilane, Methylacetoxydiethoxysilane, Methyltrihydroxysilane, Methylmethoxydihydroxysilane, Methylethoxydihydroxysilane, Methyldimethoxy Trifunctional methylsilanes such as hydroxysilanes, methylethoxymethoxyhydroxysilanes, and methyldiethoxyhydroxysilanes.

Ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrichlorosilane, ethyltriacetoxysilane, ethyltrihydroxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltrichlorosilane, propyltriacetoxysilane, propyltrihydroxysilane, butyltri Trifunctional such as methoxysilane, butyltriethoxysilane, butyltrichlorosilane, butyltriacetoxysilane, butyltrihydroxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, hexyltrichlorosilane, hexyltriacetoxysilane, hexyltrihydroxysilane. Sexual silane.

Trifunctional phenylsilanes such as phenyltrimethoxysilane, phenyltriethoxysilane, phenyltrichlorosilane, phenyltriacetoxysilane, and phenyltrihydroxysilane.

Further, an organosilicon polymer obtained by using the following in combination with an organosilicon compound having a structure represented by the formula (Z) may be used to the extent that the effect of the present invention is not impaired. An organic silicon compound having four reactive groups in one molecule (tetrafunctional silane), an organic silicon compound having two reactive groups in one molecule (bifunctional silane), or an organic silicon compound having one reactive group (bifunctional silane). Monofunctional silane). For example, the following can be mentioned.

Dimethyldiethoxysilane, tetraethoxysilane, hexamethyldisilazane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriemethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, 3- (2-amino) Ethyl) Aminopropyltriethoxysilane, vinyltriisocyanatesilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyldiethoxymethoxysilane, vinylethoxydimethoxysilane, vinylethoxydihydroxysilane, vinyldimethoxyhydroxysilane, vinylethoxymethoxyhydroxysilane, Trifunctional vinylsilanes such as vinyldiethoxyhydroxysilanes.

Further, the content of the organosilicon polymer in the toner particles is preferably 0.5% by mass or more and 10.5% by mass or less.

When the content of the organosilicon polymer is 0.5% by mass or more, the surface free energy of the surface layer can be further reduced, the fluidity can be improved, and the contamination of members and the generation of fog can be suppressed. .. When it is 10.5% by mass or less, it is possible to make it difficult for charge-up to occur. The content of the organosilicon polymer shall be controlled by the type and amount of the organosilicon compound used for forming the organosilicon polymer, the method for producing toner particles at the time of forming the organosilicon polymer, the reaction temperature, the reaction time, the reaction solvent and the pH. Can be done.

It is preferable that the surface layer containing the organosilicon polymer and the toner core particles are in close contact with each other. As a result, the generation of bleeding due to the resin component inside the surface layer of the toner particles, the mold release agent, and the like is suppressed, and it is possible to obtain a toner having excellent storage stability, environmental stability, and development durability. In addition to the above-mentioned organic silicon polymer, the surface layer may contain a resin such as a styrene-acrylic copolymer resin, a polyester resin or a urethane resin, or various additives.

[About binding resin]
The toner particles contain a binder resin. The binder resin is not particularly limited, and conventionally known ones can be used. Vinyl-based resin, polyester resin and the like are preferable. Examples of vinyl-based resins, polyester resins and other binder resins include the following resins or polymers.

Monopolymers of styrene and its substituents such as polystyrene, polyvinyltoluene; styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalin copolymer, styrene-methyl acrylate copolymer, styrene -Ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-dimethylaminoethyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-methacrylic acid Ethyl copolymer, styrene-butyl methacrylate copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinylmethyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer Stylized copolymers such as coalesced, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-maleic acid copolymers, styrene-maleic acid ester copolymers; polymethylmethacrylate, polybutylmethacrylate, poly Vinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyamide resin, epoxy resin, polyacrylic resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin. These binder resins can be used alone or in combination.

It is preferable that the binder resin contains a carboxy group from the viewpoint of chargeability, and it is preferable that the resin is produced by using a polymerizable monomer containing a carboxy group. For example, (meth) acrylic acids such as α-ethylacrylic acid and crotonic acid, and α-alkyl derivatives or β-alkyl derivatives; unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid and itaconic acid; monoacryloyl succinate. Unsaturated dicarboxylic acid monoester derivatives such as oxyethyl ester, succinic acid monoacryloyloxyethylene ester, phthalic acid monoacryloyloxyethyl ester, and phthalic acid monomethacryloyloxyethyl ester.

As the polyester resin, one obtained by polycondensing the carboxylic acid component and the alcohol component listed below can be used. Examples of the carboxylic acid component include terephthalic acid, isophthalic acid, phthalic acid, fumaric acid, maleic acid, cyclohexanedicarboxylic acid, and trimellitic acid. Examples of the alcohol component include bisphenol A, hydrogenated bisphenol, ethylene oxide adduct of bisphenol A, propylene oxide adduct of bisphenol A, glycerin, trimethylolpropane, and pentaerythritol.

Further, the polyester resin may be a polyester resin containing a urea group. As the polyester resin, it is preferable not to cap the carboxyl group such as the end.

The binder resin may have a polymerizable functional group for the purpose of improving the change in the viscosity of the toner at a high temperature. Examples of the polymerizable functional group include a vinyl group, an isocyanato group, an epoxy group, an amino group, a carboxy group and a hydroxy group.

[Crosslinking agent]
In order to control the molecular weight of the binder resin, a cross-linking agent may be added during the polymerization of the polymerizable monomer.

For example, ethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol dimethacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, divinylbenzene, bis (4). -Acryloxypolyethoxyphenyl) propane, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, Neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 200, # 400, # 600 diacrylate, dipropylene glycol diacrylate, polypropylene glycol diacrylate, polyester type Diacrylate (MANDA Nihonkayaku), and the above acrylate converted to methacrylate.

The amount of the cross-linking agent added is preferably 0.001 part by mass or more and 15,000 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer.

[About mold release agent]
The toner particles preferably contain a mold release agent. Examples of the release agent that can be used for the toner particles include paraffin wax, microcrystallin wax, petroleum wax such as petrolatum and its derivatives, Montan wax and its derivatives, hydrocarbon wax and its derivatives by the Fisher Tropsch method, polyethylene, and the like. Polyolefin waxes and derivatives thereof such as polypropylene, natural waxes and derivatives thereof such as carnauba wax and candelilla wax, fatty acids such as higher aliphatic alcohols, stearic acid and palmitic acid, or compounds thereof, acid amide waxes and ester waxes. , Ketone, hardened castor oil and its derivatives, vegetable waxes, animal waxes, silicone resins and the like. Derivatives include oxides, block copolymers with vinyl-based monomers, and graft-modified products.

The content of the release agent is preferably 5.0 parts by mass or more and 20.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin or the polymerizable monomer.

[About colorants]
The toner particles contain a colorant. The colorant is not particularly limited, and for example, known ones shown below can be used.

Examples of the yellow pigment include condensed azo compounds such as yellow iron oxide, nables yellow, naphthol yellow S, Hansa yellow G, Hansa yellow 10G, benzidine yellow G, benzidine yellow GR, quinoline yellow lake, permanent yellow NCG, and tartradin lake. Isoindolinone compounds, anthraquinone compounds, azometal complexes, methine compounds, and allylamide compounds are used. Specific examples include the following.

C. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 155, 168, 180.

Examples of the orange pigment include the following.

Permanent Orange GTR, Pyrazolone Orange, Balkan Orange, Benzidine Orange G, Indanthrone Brilliant Orange RK, Indanthrone Brilliant Orange GK.

Condensations of red pigments such as Bengala, Permanent Red 4R, Resole Red, Pyrazolone Red, Watching Red Calcium Salt, Lake Red C, Lake D, Brilliant Carmine 6B, Brilliant Carmine 3B, Eoxin Lake, Rhodamin Lake B, Alizarin Lake, etc. Examples thereof include azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds and perylene compounds. Specific examples include the following.

C. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221 and 254.

Examples of blue pigments include copper phthalocyanine compounds such as alkaline blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partial chloride, first sky blue, and induslen blue BG and their derivatives, anthraquinone compounds, and basic dye lakes. Examples include compounds. Specific examples include the following.

C. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66.

Examples of the purple pigment include Fast Violet B and Methyl Violet Lake.

Examples of the green pigment include Pigment Green B, Malachite Green Lake, and Final Yellow Green G. Examples of the white pigment include zinc oxide, titanium oxide, antimony white, and zinc sulfide.

Examples of the black pigment include carbon black, aniline black, non-magnetic ferrite, magnetite, the above-mentioned yellow colorant, red colorant and blue colorant to be toned to black. These colorants can be used alone or in admixture, and even in the form of a solid solution.

If necessary, the surface treatment of the colorant may be applied with a substance that does not inhibit polymerization.

The content of the colorant is preferably 3.0 parts by mass or more and 15.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin or the polymerizable monomer.

[About charge control agent]
The toner particles may contain a charge control agent. As the charge control agent, known ones can be used. In particular, a charge control agent having a high charge speed and capable of stably maintaining a constant charge amount is preferable. Further, when the toner particles are produced by the direct polymerization method, a charge control agent having low polymerization inhibitory property and substantially no solubilized material in an aqueous medium is particularly preferable.

Examples of the charge control agent for controlling the toner particles in a load electric manner include the following.

Examples of the organic metal compound and chelate compound include monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acids and dicarboxylic acid-based metal compounds. Others include aromatic oxycarboxylic acids, aromatic mono and polycarboxylic acids and their metal salts, anhydrides or esters, phenol derivatives such as bisphenols and the like. Further, urea derivatives, metal-containing salicylic acid-based compounds, metal-containing naphthoic acid-based compounds, boron compounds, quaternary ammonium salts, calixarene and the like can be mentioned.

On the other hand, examples of the charge control agent for controlling the toner particles to be positively charged include the following.

Niglosin modifications due to niglosin and fatty acid metal salts; guanidine compounds; imidazole compounds; tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, quaternary ammonium salts such as tetrabutylammonium tetrafluoroborate, and these. Onium salts such as phosphonium salts and their lake pigments which are similar to Lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.); Metal salt of higher fatty acid; Resin-based charge control agent.

These charge control agents can be contained alone or in combination of two or more. The amount of these charge control agents added is preferably 0.01 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the binder resin.

[External agent]
The toner of the present invention may contain an external additive other than strontium titanate particles as an external additive. For example, a fluidizing agent, a charging aid, a cleaning aid, or the like may be added in order to improve the fluidity, chargeability, cleaning property, and the like.

Examples of such an additive include inorganic oxide fine particles composed of silica fine particles, alumina fine particles, titanium oxide fine particles, positively charged particles such as hydrotalcite and melamine resin, aluminum stearate fine particles, and zinc stearate fine particles. Examples thereof include fine particles of an inorganic stearate compound such as zinc titanate, and fine particles of an inorganic titanium acid compound other than strontium titanate such as zinc titanate. These can be used alone or in combination of two or more.

It is preferable that these inorganic fine particles are gloss-treated with a silane coupling agent, a titanium coupling agent, a higher fatty acid, a silicone oil, or the like in order to improve heat storage stability and environmental stability. The BET specific surface area of the external additive is preferably 1 m ² / g or more and 450 m ² / g or less. The number average particle size is preferably 5 nm or more and 500 nm or less.

The BET specific surface area can be determined by a low-temperature gas adsorption method based on a dynamic constant pressure method according to the BET method (preferably the BET multipoint method). For example, by using a specific surface area measuring device (trade name: Gemini 2375 Ver.5.0, manufactured by Shimadzu Corporation) to adsorb nitrogen gas on the sample surface and measuring using the BET multipoint method. The BET specific surface area (m ² / g) can be calculated.

The total amount of these various external additives added is preferably 0.05 parts by mass or more and 5 parts by mass or less, and more preferably 0.1 parts by mass or more and 3 parts by mass with respect to 100 parts by mass of the toner particles. It is as follows. Further, various combinations of external additives may be used.

[Developer]
The toner of the present invention can be used as a magnetic or non-magnetic one-component developer, but may be mixed with a carrier and used as a two-component developer.

As the carrier, magnetic particles made of known materials such as metals such as iron, ferrite and magnetite, and alloys of these metals with metals such as aluminum and lead can be used. Among these, it is preferable to use ferrite particles. Further, as the carrier, a coat carrier in which the surface of the magnetic particles is coated with a coating agent such as a resin, a resin dispersion type carrier in which a magnetic fine powder is dispersed in a binder resin, or the like may be used.

The carrier preferably has a volume average particle size of 15 μm or more and 100 μm or less, and more preferably 25 μm or more and 80 μm or less.

[Manufacturing method of toner particles]
As a method for producing the toner particles, a known means can be used, and a kneading and pulverizing method or a wet production method can be used. From the viewpoint of uniform particle size and shape controllability, a wet manufacturing method can be preferably used. Further, examples of the wet production method include a suspension polymerization method, a dissolution suspension method, an emulsion polymerization aggregation method, and an emulsion aggregation method.

Here, the suspension polymerization method will be described. In the suspension polymerization method, first, a polymerizable monomer for producing a binder resin, a colorant and, if necessary, other additives are added using a disperser such as a ball mill or an ultrasonic disperser. A polymerizable monomer composition uniformly dissolved or dispersed is prepared (preparation step of the polymerizable monomer composition). At this time, if necessary, a polyfunctional monomer, a chain transfer agent, a wax as a release agent, a charge control agent, a plasticizer, or the like can be appropriately added. As the polymerizable monomer in the suspension polymerization method, the following vinyl-based polymerizable monomer can be preferably exemplified.

Styline; α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, p- Stylized derivatives such as n-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-phenyl styrene; methyl acrylate , Ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n -Acrylic polymerizable monomers such as nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate; methyl methacrylate, ethyl methacrylate. , N-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate. , Methyl-based polymerizable monomers such as diethyl phosphate ethyl methacrylate, dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid esters; vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, vinyl benzoate, Vinyl esters such as vinyl acrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl methyl ketone, vinyl hexyl ketone, vinyl isopropyl ketone.

Next, the above-mentioned polymerizable monomer composition is put into a prepared aqueous medium, and a droplet made of the polymerizable monomer composition is desired by a stirrer or a disperser having a high shearing force. It is formed to the size of the toner particles of (granulation process).

It is preferable that the aqueous medium in the granulation step contains a dispersion stabilizer in order to control the particle size of the toner particles, sharpen the particle size distribution, and suppress the coalescence of the toner particles in the manufacturing process. The dispersion stabilizer is generally classified into a polymer that develops a repulsive force due to steric hindrance and a poorly water-soluble inorganic compound that stabilizes the dispersion by an electrostatic repulsive force. Since the fine particles of the poorly water-soluble inorganic compound are dissolved by an acid or an alkali, they can be easily dissolved and easily removed by washing with an acid or an alkali after polymerization, and thus are preferably used.

As the dispersion stabilizer of the poorly water-soluble inorganic compound, one containing any one of magnesium, calcium, barium, zinc, aluminum and phosphorus is preferably used. More preferably, it is desired that any one of magnesium, calcium, aluminum and phosphorus is contained. Specifically, the following can be mentioned.

Magnesium phosphate, tricalcium phosphate, aluminum phosphate, zinc phosphate, magnesium carbonate, calcium carbonate, magnesium hydroxide, calcium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, hydroxyapatide.

Organic compounds such as polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, sodium salts of carboxymethyl cellulose, and starch may be used in combination with the dispersion stabilizer. It is preferable to use these dispersion stabilizers in an amount of 0.01 parts by mass or more and 2.00 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer.

Further, in order to make these dispersion stabilizers finer, a surfactant of 0.001 part by mass or more and 0.1 part by mass or less may be used in combination with 100 parts by mass of the polymerizable monomer. Specifically, commercially available nonionic, anionic, and cationic surfactants can be used. For example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, and calcium oleate are preferably used.

After the granulation step or while performing the granulation step, the temperature is preferably set to 50 ° C. or higher and 90 ° C. or lower to polymerize the polymerizable monomer contained in the polymerizable monomer composition, and the toner is polymerized. Obtain a particle dispersion (polymerization step).

In the polymerization step, it is preferable to perform a stirring operation so that the temperature distribution in the container becomes uniform. When the polymerization initiator is added, it can be carried out at any timing and required time. Further, the temperature may be raised in the latter half of the polymerization reaction for the purpose of obtaining a desired molecular weight distribution, and further, in the latter half of the reaction or the end of the reaction in order to remove unreacted polymerizable monomers, by-products, etc. from the system. Later, the partially aqueous medium may be distilled off by a distillation operation. The distillation operation can be performed under normal pressure or reduced pressure.

As the polymerization initiator used in the suspension polymerization method, an oil-soluble initiator is generally used. For example, the following can be mentioned.

2,2'-Azobisisobutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4 -Azo compounds such as methoxy-2,4-dimethylvaleronitrile; acetylcyclohexylsulfonyl peroxide, diisopropyl peroxycarbonate, decanonyl peroxide, lauroyl peroxide, stearoyl peroxide, propionyl peroxide, acetyl peroxide, tert- Butylperoxy-2-ethylhexanoate, benzoyl peroxide, tert-butylperoxyisobutyrate, cyclohexanone peroxide, methylethylketone peroxide, dicumyl peroxide, tert-butylhydroperoxide, di-tert-butylper Peroxide-based initiators such as oxide, tert-butylperoxypivalate, and cumenehydroperoxide.

As the polymerization initiator, a water-soluble initiator may be used in combination, if necessary, and the following may be mentioned.

Ammonium persulfate, potassium persulfate, 2,2'-azobis (N, N'-dimethyleneisobutyroamidine) hydrochloride, 2,2'-azobis (2-aminodinopropane) hydrochloride, azobis (isobutylamidin) Hydrochloride, 2,2'-azobisisobutyronitrile sodium sulfonate, ferrous sulfate or hydrogen peroxide.

These polymerization initiators can be used alone or in combination of two or more, and a chain transfer agent, a polymerization inhibitor, or the like can be further added and used in order to control the degree of polymerization of the polymerizable monomer.

The particle size of the toner particles is preferably 3.0 μm or more and 10.0 μm or less in terms of weight average particle size from the viewpoint of obtaining a high-definition and high-resolution image. The weight average particle size of the toner can be measured by the pore electric resistance method. For example, it can be measured using "Coulter Counter Multisizer 3" (manufactured by Beckman Coulter, Inc.). The toner particle dispersion liquid thus obtained is sent to a filtration step for solid-liquid separation of the toner particles and the aqueous medium.

Solid-liquid separation for obtaining toner particles from the obtained toner particle dispersion can be performed by a general filtration method, and then reslurry or washing water is used to remove foreign substances that could not be completely removed from the surface of the toner particles. It is preferable to carry out further washing by washing with a toner. After sufficient washing, solid-liquid separation is performed again to obtain a toner cake. Then, it is dried by a known drying means, and if necessary, a group of particles having an unpredictable particle size is separated by classification to obtain toner particles. At this time, the separated particle swarms having a non-predetermined particle size may be reused in order to improve the final yield.

When forming a surface layer having an organosilicon polymer, when forming toner particles in an aqueous medium, add a hydrolyzate of an organosilicon compound as described above while performing a polymerization step in the aqueous medium. The surface layer can be formed. The dispersion liquid of the toner particles after the polymerization may be used as the core particle dispersion liquid, and the hydrolyzed liquid of the organosilicon compound may be added to form the surface layer. Further, in the case of a non-aqueous medium such as a kneading and pulverizing method, the obtained toner particles are dispersed in an aqueous medium and used as a core particle dispersion, and an organosilicon compound hydrolyzate is added as described above to form the surface layer. Can be formed.

[Measuring method of toner physical properties]
<Preparation method for THF insoluble matter of toner particles for NMR measurement>
The tetrahydrofuran (THF) insoluble content of the toner particles was prepared as follows.

10.0 g of toner particles are weighed, placed in a cylindrical filter paper (No. 86R manufactured by Toyo Filter Paper), and subjected to a Soxhlet extractor. Extraction was performed using 200 mL of THF as a solvent for 20 hours, and the filtrate in the cylindrical filter paper was vacuum-dried at 40 ° C. for several hours to obtain a THF-insoluble content of toner particles for NMR measurement.

When the surface of the toner particles is treated with an external additive or the like, the external additive is removed by the following method to obtain toner particles.

Add 160 g of sucrose (manufactured by Kishida Chemical) to 100 mL of ion-exchanged water and dissolve in a water bath to prepare a sucrose concentrate. 31 g of the above sucrose concentrate in a centrifuge tube (capacity 50 mL) and 10 of a neutral detergent for cleaning a precision measuring instrument with a pH of 7 consisting of Contaminone N (nonionic surfactant, anionic surfactant, and organic builder). Add 6 mL of mass% aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.) to prepare a dispersion. Add 1.0 g of toner to this dispersion and loosen the toner lumps with a spatula or the like.

Shake the centrifuge tube on a shaker for 350 spm (strokes per min) for 20 minutes. After shaking, the solution is replaced with a glass tube for a swing rotor (capacity: 50 mL), and the solution is separated by a centrifuge (H-9R, manufactured by Kokusan Co., Ltd.) at 3500 rpm for 30 minutes. By this operation, the toner particles and the detached external additive are separated. Visually confirm that the toner and the aqueous solution are sufficiently separated, and collect the separated toner in the uppermost layer with a spatula or the like. The collected toner is filtered with a vacuum filter and then dried with a dryer for 1 hour or more to obtain toner particles. Perform this operation multiple times to secure the required amount.

<Method of confirming the partial structure represented by equation (1)>
The following method is used to confirm the partial structure represented by the formula (1) in the organosilicon polymer contained in the toner particles.

The hydrocarbon group represented by R in the formula (1) was confirmed by ¹³ C-NMR.
( ¹³ C-NMR (solid) measurement conditions)
Equipment: JEM-ECX500II manufactured by JEOL RESONANCE
Sample tube: 3.2 mmφ
Sample: Tetrahydrofuran insoluble content of toner particles for NMR measurement 150 mg
Measurement temperature: Room temperature Pulse mode: CP / MAS
Measured nuclear frequency: 123.25 MHz ( ¹³ C)
Reference substance: Adamantane (external standard: 29.5 ppm)
Sample rotation speed: 20 kHz
Contact time: 2ms
Delay time: 2s
Number of integrations: 1024 times

By this method, a methyl group (Si-CH ₃ ), an ethyl group (Si-C ₂ H ₅ ), a propyl group (Si-C ₃ H ₇ ), and a butyl group (Si-C ₄ ) bonded to a silicon atom are used. Formula (1) depending on the presence or absence of a signal due to H ₉ ), pentyl group (Si-C ₅ H ₁₁ ), hexyl group (Si-C ₆ H ₁₃ ) or phenyl group (Si-C ₆ H _5- ). The hydrocarbon group represented by R was confirmed.

<Method of calculating the ratio of the peak area attributed to the structure of the formula (1) in the organosilicon polymer contained in the toner particles>
²⁹ Si-NMR (solid-state) measurement of the THF insoluble content of the toner particles is performed under the following measurement conditions.
( ²⁹ Si-NMR (solid-state) measurement conditions)
Equipment: JEM-ECX500II manufactured by JEOL RESONANCE
Sample tube: 3.2 mmφ
Sample: Tetrahydrofuran insoluble content of toner particles for NMR measurement 150 mg
Measurement temperature: Room temperature Pulse mode: CP / MAS
Measurement nuclear frequency: 97.38 MHz ( ²⁹ Si)
Reference substance: DSS (external standard: 1.534 ppm)
Sample rotation speed: 10 kHz
Contact time: 10ms
Delay time: 2s
Accumulation number: 2000-8000 times

After the above measurement, a plurality of silane components having different substituents and bonding groups, which are insoluble in tetrahydrofuran of the toner particles, are peak-separated into the following X1 structure, X2 structure, X3 structure, and X4 structure by curve fitting, and each peak is obtained. Calculate the area.
X1 structure: (Ri) (Rj) (Rk) SiO _1/2 formula (3)
X2 structure: (Rg) (Rh) Si (O _1/2 ) ₂ formulas (4)
X3 structure: RmSi (O _1/2 ) ₃ formulas (5)
X4 structure: Si (O _1/2 ) ₄ formulas (6)

（式（３）、（４）及び（５）中のＲｉ、Ｒｊ、Ｒｋ、Ｒｇ、Ｒｈ、Ｒｍはケイ素に結合している、炭素数１～６の炭化水素基などの有機基、ハロゲン原子、ヒドロキシ基、アセトキシ基又はアルコキシ基を示す。）

(Ri, Rj, Rk, Rg, Rh, Rm in the formulas (3), (4) and (5) are organic groups such as hydrocarbon groups having 1 to 6 carbon atoms and halogen atoms bonded to silicon. , Hydroxy group, acetoxy group or alkoxy group.)

In the present invention, in the chart obtained by measuring the THF insoluble content of the toner particles in ²⁹ Si-NMR, the ratio of the peak area attributed to the structure of the formula (1) to the total peak area of the organic silicon polymer is 20. % Or more is preferable.
If it is necessary to confirm the partial structure represented by the above formula (1) in more detail, it may be identified by the measurement results of ¹ H-NMR together with the measurement results of ¹³ C-NMR and ²⁹ Si-NMR. good.

<Measuring method in which the thickness of the surface layer containing the organic silicon polymer is 2.5 nm or less, which is measured by observing the cross section of the toner particles using a transmission electron microscope (TEM)>
In the present invention, the cross-sectional observation of the toner particles is performed by the following method.

As a specific method for observing the cross section of the toner particles, the toner particles are sufficiently dispersed in a room temperature curable epoxy resin and then cured in an atmosphere of 40 ° C. for 2 days. A flaky sample is cut out from the obtained cured product using a microtome equipped with diamond teeth. This sample is magnified with a transmission electron microscope (JEM-2800 manufactured by JEOL) (TEM) at a magnification of 10,000 to 100,000 times, and the cross section of the toner particles is observed.

It is possible to confirm by utilizing the difference in atomic weight between the binder resin and the surface layer material and the fact that the contrast becomes brighter when the atomic weight is large. Ruthenium tetroxide staining and osmium tetroxide staining are used to create contrast between the materials.

For the particles used in the measurement, the equivalent circle diameter Dtem was obtained from the cross section of the toner particles obtained from the micrograph of the TEM, and the value was ± 10% of the weight average particle size D4 of the toner particles obtained by the method described later. It shall be included in the width of.

As described above, a dark field image of a cross section of toner particles is acquired at an acceleration voltage of 200 kV using JEM-2800 manufactured by JEOL. Next, using the EELS detector GIF Quantam manufactured by Gatan, a mapping image is acquired by the Three Windows method and the surface layer is confirmed.

Next, for one toner particle whose circle equivalent diameter Dtem is included in the width of ± 10% of the weight average particle diameter D4 of the toner particles, the axis L of the cross section of the toner particles and the axis passing through the center of the major axis L and perpendicular to the axis L. The cross section of the toner particles is evenly divided into 16 parts around the intersection of L90 (see FIG. 1). Next, the division axis from the center toward the surface layer of the toner particles is An (n = 1 to 32), the length of the division axis is RAn, and the thickness of the surface layer is FRAn.

Then, the ratio of the number of division shafts having a thickness of the surface layer containing the organosilicon polymer on each of the 32 division shafts having a thickness of 2.5 nm or less is determined. In order to average, 10 toner particles are measured and the average value per toner particle is calculated.

[Equivalent circle diameter (Dtem) obtained from the cross section of the toner particles obtained from a transmission electron microscope (TEM) photograph]
The equivalent circle diameter (Dtem) obtained from the cross section of the toner particles obtained from the TEM photograph is obtained by the following method. First, for one toner particle, the equivalent circle diameter Dtem obtained from the cross section of the toner particle obtained from the TEM photograph is obtained according to the following formula.
[Circle equivalent diameter (Dtem) obtained from the cross section of the toner particles obtained from the TEM photograph] = (RA1 + RA2 + RA3 + RA4 + RA5 + RA6 + RA7 + RA8 + RA9 + RA10 + RA11 + RA12 + RA13 + RA14 + RA15 + RA16 + RA17 + RA18 + RA19 + RA20 + RA22 + RA25RA + RA25

The equivalent circle diameter of 10 toner particles is obtained, and the average value per particle is calculated to obtain the equivalent circle diameter (Dtem) obtained from the cross section of the toner particles.

[Ratio of surface layer containing organosilicon polymer with a thickness of 2.5 nm or less]
[Ratio of surface layer thickness (FRAn) containing organosilicon polymer of 2.5 nm or less] = [{Number of split axes having surface layer thickness (FRAn) containing organosilicon polymer of 2.5 nm or less] } / 32] x 100

This calculation was performed on 10 toner particles, and the average value of the ratio of the obtained 10 surface layer thicknesses (FRAn) of 2.5 nm or less was obtained, and the surface layer thickness (FRAn) of the toner particles was 2. The ratio was 5 nm or less.

<Measurement of particle size of toner particles>
A precision particle size distribution measuring device (trade name: Coulter Counter Multisizer 3) by the pore electrical resistance method and dedicated software (trade name: Beckman Coulter Multisizer 3 Version 3.51, manufactured by Beckman Coulter) are used. Aperture diameter of 100 μm is used, measurement is performed with an effective measurement channel number of 25,000 channels, and the measurement data is analyzed and calculated. As the electrolytic aqueous solution used for the measurement, a special grade sodium chloride dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, ISOTON II (trade name) manufactured by Beckman Coulter can be used. Before performing measurement and analysis, set the dedicated software as follows.

In the "Change standard measurement method (SOM) screen" of the dedicated software, set the total count number of the control mode to 50,000 particles, measure once, and set the Kd value (standard particles 10.0 μm, Beckman Coulter). The value obtained by using (manufactured by) is set. 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, the electrolyte to ISOTON II (trade name), 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 to 2 μm or more and 60 μm or less.

The specific measurement method is as follows.
(1) Put about 200 mL of the electrolytic aqueous solution in a glass 250 mL round bottom beaker dedicated to Multisizer 3, set it on a sample stand, and stir the stirrer rod counterclockwise at 24 rpm. Then, the dirt and air bubbles in the aperture tube are removed by the "aperture flash" function of the analysis software.
(2) Put about 30 mL of the electrolytic aqueous solution in a 100 mL flat-bottomed beaker made of glass. About 0. Add 3 mL.
(3) Two oscillators with an oscillation frequency of 50 kHz are built in with the phase shifted by 180 degrees, and an ultrasonic disperser with an electrical output of 120 W (trade name: Ultrasonic Dispersion System Tetora150, manufactured by Nikkaki Bios Co., Ltd.)
Add about 2 mL of ion-exchanged water and Contaminone N (trade name) to the water tank.
(4) The beaker of (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) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, about 10 mg of toner (particles) is added little by little to the electrolytic aqueous solution and dispersed. Then, the ultrasonic dispersion processing is continued for another 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) The electrolytic aqueous solution of (5) in which toner (particles) is dispersed is dropped onto the round bottom beaker of (1) installed in the sample stand so that the measured concentration becomes about 5%. Adjust to. Then, the measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed by the dedicated software attached to the device, and the weight average particle size (D4) is calculated. The "average diameter" of the analysis / volume statistical value (arithmetic mean) screen when the graph / volume% is set by the dedicated software is the weight average particle diameter (D4). The "average diameter" of the "analysis / number statistical value (arithmetic mean)" screen when the graph / number% is set by the dedicated software is the number average particle size (D1).

<Measurement of the content of organosilicon polymer in toner particles>
The content of the organic silicon polymer is measured by the wavelength dispersive fluorescent X-ray analyzer "Axios" (manufactured by PANalytical) and the attached dedicated software "SuperQ ver.4" for setting measurement conditions and analyzing measurement data. 0F ”(manufactured by PANalytical) is used. 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. Further, when measuring a light element, 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 4 g of toner particles in a dedicated press aluminum ring, flatten it, and use a tablet molding compressor "BRE-32" (manufactured by Maekawa Testing Machine Mfg. Co., Ltd.) at 20 MPa, 60. Pressurize for seconds and use pellets molded to a thickness of 2 mm and a diameter of 39 mm.

Silica (SiO ₂ ) fine powder is added to 100 parts by mass of toner particles containing no organic silicon polymer so as to be 0.5 parts by mass, and the mixture is sufficiently mixed using a coffee mill. Similarly, the silica fine powder is mixed with the toner particles so as to be 5.0 parts by mass and 10.0 parts by mass, respectively, and these are used as a sample for a calibration curve.

For each sample, pellets of the sample for the calibration curve were prepared as described above using a tablet molding compressor, and when PET was used for the spectroscopic crystal, the diffraction angle (2θ) = 109.08 ° was observed. The counting rate (unit: cps) of the Si—Kα ray 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 count rate of the obtained X-rays on the vertical axis and the amount of SiO ₂ added in each calibration curve sample on the horizontal axis.

Next, the toner particles to be analyzed are pelletized as described above using a tablet molding compressor, and the count rate of Si—Kα rays is measured. Then, the content of the organosilicon polymer in the toner particles is obtained from the above calibration curve.

<Measurement method of fixation rate of organosilicon polymer>
Add 160 g of sucrose (manufactured by Kishida Chemical) to 100 mL of ion-exchanged water and dissolve in a water bath to prepare a sucrose concentrate. 31 g of the above sucrose concentrate in a centrifuge tube (capacity 50 ml) and 10 of a neutral detergent for cleaning a precision measuring instrument with a pH of 7 consisting of Contaminone N (nonionic surfactant, anionic surfactant, and organic builder). Add 6 mL of mass% aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.) to prepare a dispersion. Add 1.0 g of toner to this dispersion and loosen the toner lumps with a spatula or the like.

Shake the centrifuge tube on a shaker for 350 spm (strokes per min) for 20 minutes. After shaking, the solution is replaced with a glass tube for a swing rotor (capacity: 50 mL), and the solution is separated by a centrifuge (H-9R, manufactured by Kokusan Co., Ltd.) at 3500 rpm for 30 minutes. Visually confirm that the toner and the aqueous solution are sufficiently separated, and collect the separated toner in the uppermost layer with a spatula or the like. After filtering the aqueous solution containing the collected toner with a vacuum filter, it is dried in a dryer for 1 hour or more. The dried product is crushed with a spatula and the amount of silicon is measured by fluorescent X-ray. The fixing rate (%) is calculated from the element amount ratio of the toner after washing with water and the element amount ratio of the initial toner to be measured.

The measurement of fluorescent X-rays of each element conforms to JIS K 0119-1969, but the specifics are as follows.

As the measuring device, the wavelength dispersive fluorescent X-ray analyzer "Axios" (manufactured by PANalytical) and the attached dedicated software "SuperQ ver.4.0F" (manufactured by PANalytical) for setting measurement conditions and analyzing measurement data ) Is used. Rh is used as the anode of the X-ray tube, the measurement atmosphere is vacuum, the measurement diameter (collimator mask diameter) is 10 mm, and the measurement time is 10 seconds. Further, when measuring a light element, 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 1 g of the toner after washing with water and the initial toner in a dedicated press aluminum ring with a diameter of 10 mm and flatten it, and then flatten the tablet molding compressor "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.

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

As a quantification method in the toner, for example, the amount of silicon is added so that the amount of silicon is 0.5 parts by mass with respect to 100 parts by mass of toner particles, for example, silica (SiO ₂ ) fine powder is sufficiently mixed using a coffee mill. do. Similarly, the silica fine powder is mixed with the toner particles so as to be 2.0 parts by mass and 5.0 parts by mass, respectively, and these are used as a sample for a calibration curve.

For each sample, pellets of the sample for the calibration curve were prepared as described above using a tablet molding compressor, and when PET was used for the spectroscopic crystal, the diffraction angle (2θ) = 109.08 ° was observed. The counting rate (unit: cps) of the Si—Kα ray 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 count rate of the obtained X-rays on the vertical axis and the amount of SiO ₂ added in each calibration curve sample on the horizontal axis.

Next, the toner to be analyzed is pelletized as described above using a tablet molding compressor, and the count rate of Si—Kα rays is measured. Then, the content of the organosilicon polymer in the toner is determined from the above calibration curve. The ratio of the elemental amount of the toner after washing with water to the elemental amount of the initial toner calculated by the above method was obtained and used as the fixing rate (%).

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, all "parts" of each material in Examples and Comparative Examples are based on mass.

The strontium titanate particles were prepared as follows. Table 1 shows the physical characteristics of the strontium titanate particles 1 to 15.

<Production example of strontium titanate particles 1>
After deironing and bleaching the metatitanic acid obtained by the sulfuric acid method, an aqueous sodium hydroxide solution was added to adjust the pH to 9.0, desulfurization was performed, and then neutralization to pH 5.8 with hydrochloric acid and washing with filtered water were performed. Water was added to the washed cake to make a slurry of 1.85 mol / L as TiO ₂ , and then hydrochloric acid was added to adjust the pH to 1.0 and degluing treatment was performed.

1.88 mol of desulfurized and deglutinized metatitanium acid was collected as TiO ₂ and placed in a 3 L reaction vessel. A strontium chloride aqueous solution was added to the deflated metatitanium acid slurry in an amount of 2.16 mol so that the Sr / Ti (molar ratio) was 1.15, and then the TiO ₂ concentration was adjusted to 1.039 mol / L.

Next, after heating to 90 ° C. with stirring and mixing, 440 mL of a 10 mol / L sodium hydroxide aqueous solution was added over 45 minutes, and then stirring was continued at 95 ° C. for 1 hour to complete the reaction.

The reaction slurry was cooled to 50 ° C., hydrochloric acid was added until the pH reached 5.0, and stirring was continued for 20 minutes. The obtained precipitate was decanted and washed, filtered and separated, and then dried in the air at 120 ° C. for 8 hours.

Subsequently, 300 g of the dried product was put into a dry particle composite device (Nobilta NOB-130 manufactured by Hosokawa Micron). The treatment was carried out at a treatment temperature of 30 ° C. and a rotary treatment blade of 90 m / sec for 10 minutes.

Further, hydrochloric acid was added to the dried product until the pH reached 0.1, and stirring was continued for 1 hour. The resulting precipitate was decanted and washed.

The slurry containing the precipitate was adjusted to 40 ° C., hydrochloric acid was added to adjust the pH to 2.5, 4.0% by mass of n-octyltriethoxysilane was added to the solid content, and stirring and holding were continued for 10 hours. .. After adding 5 mol / L sodium hydroxide solution to adjust the pH to 6.5 and continuing stirring for 1 hour, the cake obtained by filtration and washing was dried in the air at 120 ° C. for 8 hours to obtain strontium titanate particles 1. Obtained. A transmission electron micrograph of the strontium titanate particle 1 is shown in FIG.

<Production example of strontium titanate particles 2>
After deironing and bleaching the metatitanic acid obtained by the sulfuric acid method, an aqueous sodium hydroxide solution was added to adjust the pH to 9.0, desulfurization was performed, and then neutralization to pH 5.8 with hydrochloric acid and washing with filtered water were performed. Water was added to the washed cake to make a slurry of 1.85 mol / L as TiO ₂ , and then hydrochloric acid was added to adjust the pH to 1.0 and degluing treatment was performed.

1.88 mol of desulfurized and deglutinized metatitanium acid was collected as TiO ₂ and placed in a 3 L reaction vessel. A strontium chloride aqueous solution was added to the deflated metatitanium acid slurry in an amount of 2.16 mol so that the Sr / Ti (molar ratio) was 1.15, and then the TiO ₂ concentration was adjusted to 1.083 mol / L.

Next, after heating to 90 ° C. with stirring and mixing, 440 mL of a 10 mol / L sodium hydroxide aqueous solution was added over 45 minutes, and then stirring was continued at 95 ° C. for 1 hour to complete the reaction.

The reaction slurry was cooled to 50 ° C., hydrochloric acid was added until the pH reached 5.0, and stirring was continued for 20 minutes. The obtained precipitate was decanted and washed, filtered and separated, and then dried in the air at 120 ° C. for 8 hours.

Subsequently, 300 g of the dried product was put into a dry particle composite device (Nobilta NOB-130 manufactured by Hosokawa Micron). The treatment was carried out at a treatment temperature of 30 ° C. and a rotary treatment blade of 90 m / sec for 10 minutes.

Further, hydrochloric acid was added to the dried product until the pH reached 0.1, and stirring was continued for 1 hour. The resulting precipitate was decanted and washed.

The slurry containing the precipitate was adjusted to 40 ° C., hydrochloric acid was added to adjust the pH to 2.5, 4.0% by mass of n-octyltriethoxysilane was added to the solid content, and stirring and holding were continued for 10 hours. .. After adding 5 mol / L sodium hydroxide solution to adjust the pH to 6.5 and continuing stirring for 1 hour, the cake obtained by filtration and washing was dried in the air at 120 ° C. for 8 hours to obtain strontium titanate particles 2. Obtained.

<Production example of strontium titanate particles 3>
After deironing and bleaching the metatitanic acid obtained by the sulfuric acid method, an aqueous sodium hydroxide solution was added to adjust the pH to 9.0, desulfurization was performed, and then neutralization to pH 5.8 with hydrochloric acid and washing with filtered water were performed. Water was added to the washed cake to make a slurry of 1.85 mol / L as TiO ₂ , and then hydrochloric acid was added to adjust the pH to 1.0 and degluing treatment was performed.

1.88 mol of desulfurized and deglutinized metatitanium acid was collected as TiO ₂ and placed in a 3 L reaction vessel. A strontium chloride aqueous solution was added to the deflated metatitanium acid slurry in an amount of 2.16 mol so that the Sr / Ti (molar ratio) was 1.15, and then the TiO ₂ concentration was adjusted to 1.015 mol / L.

Next, after heating to 90 ° C. with stirring and mixing, 440 mL of a 10 mol / L sodium hydroxide aqueous solution was added over 45 minutes, and then stirring was continued at 95 ° C. for 1 hour to complete the reaction.

The reaction slurry was cooled to 50 ° C., hydrochloric acid was added until the pH reached 5.0, and stirring was continued for 20 minutes. The obtained precipitate was decanted and washed, filtered and separated, and then dried in the air at 120 ° C. for 8 hours.

Subsequently, 300 g of the dried product was put into a dry particle composite device (Nobilta NOB-130 manufactured by Hosokawa Micron). The treatment was carried out at a treatment temperature of 30 ° C. and a rotary treatment blade of 90 m / sec for 10 minutes.

Further, hydrochloric acid was added to the dried product until the pH reached 0.1, and stirring was continued for 1 hour. The resulting precipitate was decanted and washed.

The slurry containing the precipitate was adjusted to 40 ° C., hydrochloric acid was added to adjust the pH to 2.5, 4.0% by mass of n-octyltriethoxysilane was added to the solid content, and stirring and holding were continued for 10 hours. .. After adding 5 mol / L sodium hydroxide solution to adjust the pH to 6.5 and continuing stirring for 1 hour, the cake obtained by filtration and washing was dried in the air at 120 ° C. for 8 hours to obtain strontium titanate particles 3. Obtained.

<Production example of strontium titanate particles 4>
After deironing and bleaching the metatitanic acid obtained by the sulfuric acid method, an aqueous sodium hydroxide solution was added to adjust the pH to 9.0, desulfurization was performed, and then neutralization to pH 5.8 with hydrochloric acid and washing with filtered water were performed. Water was added to the washed cake to make a slurry of 1.85 mol / L as TiO ₂ , and then hydrochloric acid was added to adjust the pH to 1.0 and degluing treatment was performed.

1.88 mol of desulfurized and deglutinized metatitanium acid was collected as TiO ₂ and placed in a 3 L reaction vessel. A strontium chloride aqueous solution was added to the deflated metatitanic acid slurry in an amount of 2.16 mol so that the Sr / Ti (molar ratio) was 1.15, and then the TiO ₂ concentration was adjusted to 0.988 mol / L.

Next, after heating to 90 ° C. with stirring and mixing, 440 mL of a 10 mol / L sodium hydroxide aqueous solution was added over 45 minutes, and then stirring was continued at 95 ° C. for 1 hour to complete the reaction.

The reaction slurry was cooled to 50 ° C., hydrochloric acid was added until the pH reached 5.0, and stirring was continued for 20 minutes. The obtained precipitate was decanted and washed, filtered and separated, and then dried in the air at 120 ° C. for 8 hours.

Subsequently, 300 g of the dried product was put into a dry particle composite device (Nobilta NOB-130 manufactured by Hosokawa Micron). The treatment was carried out at a treatment temperature of 30 ° C. and a rotary treatment blade of 90 m / sec for 10 minutes.

Further, hydrochloric acid was added to the dried product until the pH reached 0.1, and stirring was continued for 1 hour. The resulting precipitate was decanted and washed.

The slurry containing the precipitate was adjusted to 40 ° C., hydrochloric acid was added to adjust the pH to 2.5, 4.0% by mass of n-octyltriethoxysilane was added to the solid content, and stirring and holding were continued for 10 hours. .. After adding 5 mol / L sodium hydroxide solution to adjust the pH to 6.5 and continuing stirring for 1 hour, the cake obtained by filtration and washing was dried in the air at 120 ° C. for 8 hours to obtain strontium titanate particles 4. Obtained.

<Production example of strontium titanate particles 5>
After deironing and bleaching the metatitanic acid obtained by the sulfuric acid method, an aqueous sodium hydroxide solution was added to adjust the pH to 9.0, desulfurization was performed, and then neutralization to pH 5.8 with hydrochloric acid and washing with filtered water were performed. Water was added to the washed cake to make a slurry of 1.85 mol / L as TiO ₂ , and then hydrochloric acid was added to adjust the pH to 1.0 and degluing treatment was performed.

1.88 mol of desulfurized and deglutinized metatitanium acid was collected as TiO ₂ and placed in a 3 L reaction vessel. A strontium chloride aqueous solution was added to the deflated metatitanium acid slurry in an amount of 2.16 mol so that the Sr / Ti (molar ratio) was 1.15, and then the TiO ₂ concentration was adjusted to 1.039 mol / L.

Next, after heating to 90 ° C. with stirring and mixing, 440 mL of a 10 mol / L sodium hydroxide aqueous solution was added over 45 minutes, and then stirring was continued at 95 ° C. for 1 hour to complete the reaction.

The reaction slurry was cooled to 50 ° C., hydrochloric acid was added until the pH reached 5.0, and stirring was continued for 20 minutes. The obtained precipitate was decanted and washed, filtered and separated, and then dried in the air at 120 ° C. for 8 hours.

Subsequently, 300 g of the dried product was put into a dry particle composite device (Nobilta NOB-130 manufactured by Hosokawa Micron). The treatment was carried out at a treatment temperature of 30 ° C. and a rotary treatment blade of 90 m / sec for 15 minutes.

Further, hydrochloric acid was added to the dried product until the pH reached 0.1, and stirring was continued for 1 hour. The resulting precipitate was decanted and washed.

The slurry containing the precipitate was adjusted to 40 ° C., hydrochloric acid was added to adjust the pH to 2.5, 4.0% by mass of n-octyltriethoxysilane was added to the solid content, and stirring and holding were continued for 10 hours. .. After adding 5 mol / L sodium hydroxide solution to adjust the pH to 6.5 and continuing stirring for 1 hour, the cake obtained by filtration and washing was dried in the air at 120 ° C. for 8 hours to obtain strontium titanate particles 5. Obtained.

<Production example of strontium titanate particles 6>
After deironing and bleaching the metatitanic acid obtained by the sulfuric acid method, an aqueous sodium hydroxide solution was added to adjust the pH to 9.0, desulfurization was performed, and then neutralization to pH 5.8 with hydrochloric acid and washing with filtered water were performed. Water was added to the washed cake to make a slurry of 1.85 mol / L as TiO ₂ , and then hydrochloric acid was added to adjust the pH to 1.0 and degluing treatment was performed.

1.88 mol of desulfurized and deglutinized metatitanium acid was collected as TiO ₂ and placed in a 3 L reaction vessel. A strontium chloride aqueous solution was added to the deflated metatitanium acid slurry in an amount of 2.16 mol so that the Sr / Ti (molar ratio) was 1.15, and then the TiO ₂ concentration was adjusted to 1.039 mol / L.

Next, after heating to 90 ° C. with stirring and mixing, 440 mL of a 10 mol / L sodium hydroxide aqueous solution was added over 45 minutes, and then stirring was continued at 95 ° C. for 1 hour to complete the reaction.

The reaction slurry was cooled to 50 ° C., hydrochloric acid was added until the pH reached 5.0, and stirring was continued for 20 minutes. The obtained precipitate was decanted and washed, filtered and separated, and then dried in the air at 120 ° C. for 8 hours.

Subsequently, 300 g of the dried product was put into a dry particle composite device (Nobilta NOB-130 manufactured by Hosokawa Micron). The treatment was carried out at a treatment temperature of 30 ° C. and a rotary treatment blade of 90 m / sec for 5 minutes.

Further, hydrochloric acid was added to the dried product until the pH reached 0.1, and stirring was continued for 1 hour. The resulting precipitate was decanted and washed.

The slurry containing the precipitate was adjusted to 40 ° C., hydrochloric acid was added to adjust the pH to 2.5, 4.0% by mass of n-octyltriethoxysilane was added to the solid content, and stirring and holding were continued for 10 hours. .. After adding 5 mol / L sodium hydroxide solution to adjust the pH to 6.5 and continuing stirring for 1 hour, the cake obtained by filtration and washing was dried in the air at 120 ° C. for 8 hours to obtain strontium titanate particles 6. Obtained.

<Production example of strontium titanate particles 7>
After deironing and bleaching the metatitanic acid obtained by the sulfuric acid method, an aqueous sodium hydroxide solution was added to adjust the pH to 9.0, desulfurization was performed, and then neutralization to pH 5.8 with hydrochloric acid and washing with filtered water were performed. Water was added to the washed cake to make a slurry of 1.85 mol / L as TiO ₂ , and then hydrochloric acid was added to adjust the pH to 1.0 and degluing treatment was performed.

1.88 mol of desulfurized and deglutinized metatitanium acid was collected as TiO ₂ and placed in a 3 L reaction vessel. 2.01 mol of an aqueous solution of strontium chloride was added to the deflated metatitanic acid slurry so as to have an Sr / Ti (molar ratio) of 1.07, and then the TiO ₂ concentration was adjusted to 1.039 mol / L.

Next, after heating to 90 ° C. with stirring and mixing, 440 mL of a 10 mol / L sodium hydroxide aqueous solution was added over 45 minutes, and then stirring was continued at 95 ° C. for 1 hour to complete the reaction.

The reaction slurry was cooled to 50 ° C., hydrochloric acid was added until the pH reached 5.0, and stirring was continued for 20 minutes. The obtained precipitate was decanted and washed, filtered and separated, and then dried in the air at 120 ° C. for 8 hours.

Subsequently, 300 g of the dried product was put into a dry particle composite device (Nobilta NOB-130 manufactured by Hosokawa Micron). The treatment was carried out at a treatment temperature of 30 ° C. and a rotary treatment blade of 90 m / sec for 10 minutes.

Further, hydrochloric acid was added to the dried product until the pH reached 0.1, and stirring was continued for 1 hour. The resulting precipitate was decanted and washed.

The slurry containing the precipitate was adjusted to 40 ° C., hydrochloric acid was added to adjust the pH to 2.5, 4.0% by mass of n-octyltriethoxysilane was added to the solid content, and stirring and holding were continued for 10 hours. .. After adding 5 mol / L sodium hydroxide solution to adjust the pH to 6.5 and continuing stirring for 1 hour, the cake obtained by filtration and washing was dried in the air at 120 ° C. for 8 hours to obtain strontium titanate particles 7. Obtained.

<Production example of strontium titanate particles 8>
After deironing and bleaching the metatitanic acid obtained by the sulfuric acid method, an aqueous sodium hydroxide solution was added to adjust the pH to 9.0, desulfurization was performed, and then neutralization to pH 5.8 with hydrochloric acid and washing with filtered water were performed. Water was added to the washed cake to make a slurry of 1.85 mol / L as TiO ₂ , and then hydrochloric acid was added to adjust the pH to 1.0 and degluing treatment was performed.

1.88 mol of desulfurized and deglutinized metatitanium acid was collected as TiO ₂ and placed in a 3 L reaction vessel. 2.54 mol of an aqueous solution of strontium chloride was added to the deflated metatitanic acid slurry so as to have an Sr / Ti (molar ratio) of 1.35, and then the TiO ₂ concentration was adjusted to 1.039 mol / L.

Next, after heating to 90 ° C. with stirring and mixing, 440 mL of a 10 mol / L sodium hydroxide aqueous solution was added over 45 minutes, and then stirring was continued at 95 ° C. for 1 hour to complete the reaction.

The reaction slurry was cooled to 50 ° C., hydrochloric acid was added until the pH reached 5.0, and stirring was continued for 20 minutes. The obtained precipitate was decanted and washed, filtered and separated, and then dried in the air at 120 ° C. for 8 hours.

Subsequently, 300 g of the dried product was put into a dry particle composite device (Nobilta NOB-130 manufactured by Hosokawa Micron). The treatment was carried out at a treatment temperature of 30 ° C. and a rotary treatment blade of 90 m / sec for 10 minutes.

Further, hydrochloric acid was added to the dried product until the pH reached 0.1, and stirring was continued for 1 hour. The resulting precipitate was decanted and washed.

The slurry containing the precipitate was adjusted to 40 ° C., hydrochloric acid was added to adjust the pH to 2.5, 4.0% by mass of n-octyltriethoxysilane was added to the solid content, and stirring and holding were continued for 10 hours. .. After adding 5 mol / L sodium hydroxide solution to adjust the pH to 6.5 and continuing stirring for 1 hour, the cake obtained by filtration and washing was dried in the air at 120 ° C. for 8 hours to obtain strontium titanate particles 8. Obtained.

<Production example of strontium titanate particles 9>
After deironing and bleaching the metatitanic acid obtained by the sulfuric acid method, an aqueous sodium hydroxide solution was added to adjust the pH to 9.0, desulfurization was performed, and then neutralization to pH 5.8 with hydrochloric acid and washing with filtered water were performed. Water was added to the washed cake to make a slurry of 1.85 mol / L as TiO ₂ , and then hydrochloric acid was added to adjust the pH to 1.0 and degluing treatment was performed.

1.88 mol of desulfurized and deglutinized metatitanium acid was collected as TiO ₂ and placed in a 3 L reaction vessel. 2.54 mol of an aqueous solution of strontium chloride was added to the deflated metatitanic acid slurry so as to have an Sr / Ti (molar ratio) of 1.35, and then the TiO ₂ concentration was adjusted to 1.039 mol / L.

Next, after heating to 90 ° C. with stirring and mixing, 440 mL of a 10 mol / L sodium hydroxide aqueous solution was added over 45 minutes, and then stirring was continued at 95 ° C. for 1 hour to complete the reaction.

The reaction slurry was cooled to 50 ° C., hydrochloric acid was added until the pH reached 5.0, and stirring was continued for 20 minutes. The obtained precipitate was decanted and washed, filtered and separated, and then dried in the air at 120 ° C. for 8 hours.

Subsequently, 300 g of the dried product was put into a dry particle composite device (Nobilta NOB-130 manufactured by Hosokawa Micron). The treatment was carried out at a treatment temperature of 30 ° C. and a rotary treatment blade of 90 m / sec for 10 minutes.

Further, hydrochloric acid was added to the dried product until the pH reached 0.1, and stirring was continued for 1 hour. The resulting precipitate was decanted and washed.

The slurry containing the precipitate was adjusted to 70 ° C., 4.0% by mass of sodium stearate was added to the solid content, and stirring and holding was continued for 1 hour. After adding 5 mol / L sodium hydroxide solution to adjust the pH to 6.5 and continuing stirring for 1 hour, the cake obtained by filtration and washing was dried in the air at 120 ° C. for 8 hours to obtain strontium titanate particles 9. Obtained.

<Production example of strontium titanate particles 10>
After deironing and bleaching the metatitanic acid obtained by the sulfuric acid method, an aqueous sodium hydroxide solution was added to adjust the pH to 9.0, desulfurization was performed, and then neutralization to pH 5.8 with hydrochloric acid and washing with filtered water were performed. Water was added to the washed cake to make a slurry of 1.85 mol / L as TiO ₂ , and then hydrochloric acid was added to adjust the pH to 1.0 and degluing treatment was performed.

1.88 mol of desulfurized and deglutinized metatitanium acid was collected as TiO ₂ and placed in a 3 L reaction vessel. 2.54 mol of an aqueous solution of strontium chloride was added to the deflated metatitanic acid slurry so as to have an Sr / Ti (molar ratio) of 1.35, and then the TiO ₂ concentration was adjusted to 1.039 mol / L.

Next, after heating to 90 ° C. with stirring and mixing, 440 mL of a 10 mol / L sodium hydroxide aqueous solution was added over 45 minutes, and then stirring was continued at 95 ° C. for 1 hour to complete the reaction.

The reaction slurry was cooled to 50 ° C., hydrochloric acid was added until the pH reached 5.0, and stirring was continued for 20 minutes. The obtained precipitate was decanted and washed, filtered and separated, and then dried in the air at 120 ° C. for 8 hours.

Subsequently, the dried product was treated with a hybridizer (manufactured by Nara Machinery Co., Ltd.) at 6,000 rpm for 3 minutes three times.

Further, hydrochloric acid was added to the dried product until the pH reached 0.1, and stirring was continued for 1 hour. The obtained precipitate was decantated and washed, filtered and washed, and the obtained cake was dried in the air at 120 ° C. for 8 hours to obtain strontium titanate particles 10.

<Production example of strontium titanate particles 11>
After deironing and bleaching the metatitanic acid obtained by the sulfuric acid method, an aqueous sodium hydroxide solution was added to adjust the pH to 9.0, desulfurization was performed, and then neutralization to pH 5.8 with hydrochloric acid and washing with filtered water were performed. Water was added to the washed cake to make a slurry of 1.85 mol / L as TiO ₂ , and then hydrochloric acid was added to adjust the pH to 1.0 and degluing treatment was performed.

1.88 mol of desulfurized and deglutinized metatitanium acid was collected as TiO ₂ and placed in a 3 L reaction vessel. A strontium chloride aqueous solution was added to the deflated metatitanium acid slurry in an amount of 2.16 mol so that the Sr / Ti (molar ratio) was 1.15, and then the TiO ₂ concentration was adjusted to 1.039 mol / L.

Next, after heating to 90 ° C. with stirring and mixing, 440 mL of a 10 mol / L sodium hydroxide aqueous solution was added over 45 minutes, and then stirring was continued at 95 ° C. for 1 hour to complete the reaction.

The reaction slurry was cooled to 50 ° C., hydrochloric acid was added until the pH reached 5.0, and stirring was continued for 1 hour. The resulting precipitate was decanted and washed.

The slurry containing the precipitate was adjusted to 40 ° C., hydrochloric acid was added to adjust the pH to 2.5, 4.0% by mass of n-octyltriethoxysilane was added to the solid content, and stirring and holding were continued for 10 hours. .. After adding 5 mol / L sodium hydroxide solution to adjust the pH to 6.5 and continuing stirring for 1 hour, the cake obtained by filtration and washing was dried in the air at 120 ° C. for 8 hours to obtain strontium titanate particles 11. Obtained.

<Production example of strontium titanate particles 12>
The metatitanic acid slurry obtained by hydrolyzing an aqueous solution of titanyl sulfate was washed with an aqueous alkaline solution.

Next, hydrochloric acid was added to the metatitanic acid slurry to adjust the pH to 0.65 to obtain a titania sol dispersion.

NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 4.5, and washing was repeated until the electrical conductivity of the supernatant reached 70 μS / cm.

A 0.97-fold molar amount of strontium hydroxide octahydrate was added to the metatitanic acid slurry, placed in a stainless steel reaction vessel, and replaced with nitrogen gas.

Further, distilled water was added so as to be 0.5 mol / L in terms of TiO ₂ . The slurry was heated to 83 ° C. at 6.5 ° C./hour in a nitrogen atmosphere, and the reaction was carried out for 6 hours after reaching 83 ° C. The obtained precipitate was decantated and washed, filtered and separated, and then dried in the air at 120 ° C. for 8 hours to obtain strontium titanate particles 12.

<Production example of strontium titanate particles 13>
After deironing and bleaching the metatitanic acid obtained by the sulfuric acid method, an aqueous sodium hydroxide solution was added to adjust the pH to 9.0, desulfurization was performed, and then neutralization to pH 5.8 with hydrochloric acid and washing with filtered water were performed. Water was added to the washed cake to make a slurry of 1.85 mol / L as TiO ₂ , and then hydrochloric acid was added to adjust the pH to 1.0 and degluing treatment was performed.

1.88 mol of desulfurized and deglutinized metatitanium acid was collected as TiO ₂ and placed in a 3 L reaction vessel. An aqueous solution of strontium chloride was added to the deflated metatitanic acid slurry in an amount of 2.16 mol so that the Sr / Ti (molar ratio) was 1.15, and then the TiO ₂ concentration was adjusted to 0.960 mol / L.

Next, after heating to 90 ° C. with stirring and mixing, 440 mL of a 10 mol / L sodium hydroxide aqueous solution was added over 45 minutes, and then stirring was continued at 95 ° C. for 1 hour to complete the reaction.

The reaction slurry was cooled to 50 ° C., hydrochloric acid was added until the pH reached 5.0, and stirring was continued for 20 minutes. The obtained precipitate was decanted and washed, filtered and separated, and then dried in the air at 120 ° C. for 8 hours.

Subsequently, 300 g of the dried product was put into a dry particle composite device (Nobilta NOB-130 manufactured by Hosokawa Micron). The treatment was carried out at a treatment temperature of 30 ° C. and a rotary treatment blade of 90 m / sec for 10 minutes.

Further, hydrochloric acid was added to the dried product until the pH reached 0.1, and stirring was continued for 1 hour. The resulting precipitate was decanted and washed.

The slurry containing the precipitate was adjusted to 40 ° C., hydrochloric acid was added to adjust the pH to 2.5, 4.0% by mass of n-octyltriethoxysilane was added to the solid content, and stirring and holding were continued for 10 hours. .. After adding 5 mol / L sodium hydroxide solution to adjust the pH to 6.5 and continuing stirring for 1 hour, the cake obtained by filtration and washing was dried in the air at 120 ° C. for 8 hours to obtain strontium titanate particles 13. Obtained.

<Production example of strontium titanate particles 14>
Hydrolyzed titanium hydroxide obtained by adding aqueous ammonia to the titanium tetrachloride aqueous solution was washed with pure water, and 0.25% sulfuric acid was added as SO ₃ to the titanium hydroxide slurry to the titanium hydroxide slurry. did.

Next, hydrochloric acid was added to the hydroxide-containing titanium slurry to adjust the pH to 0.65 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 4.7, and washing was repeated until the electrical conductivity of the supernatant reached 50 μS / cm.

A 0.95 times molar amount of strontium hydroxide octahydrate was added to the titanium hydroxide-containing titanium, and the mixture was placed in a stainless steel reaction vessel and replaced with nitrogen gas. Further, distilled water was added so as to be 0.6 mol / L in terms of SrTiO ₃ .

The slurry was heated to 65 ° C. at 10 ° C./hour in a nitrogen atmosphere, and the reaction was carried out for 8 hours after reaching 65 ° C. After the reaction, the mixture was cooled to room temperature, the supernatant was removed, and then washing with pure water was repeated.

Further, under a nitrogen atmosphere, the above slurry was placed in an aqueous solution in which 2% by mass of sodium stearate was dissolved with respect to the solid content of the slurry, and a magnesium sulfate aqueous solution was added dropwise with stirring to add stearic acid to the surface of the perovskite-type crystal. Magnesium was precipitated.

The slurry was repeatedly washed with pure water and then filtered through Nutche, and the obtained cake was dried to obtain strontium titanate particles 14 surface-treated with magnesium stearate.

<Production example of strontium titanate particles 15>
The hydroxide-containing titanium slurry obtained by hydrolyzing an aqueous solution of titanyl sulfate was washed with an aqueous alkaline solution. Next, hydrochloric acid was added to the hydroxide-containing titanium slurry to adjust the pH to 4.0 to obtain a titania sol dispersion. NaOH was added to the titania sol dispersion, the pH of the dispersion was adjusted to 8.0, and washing was repeated until the electrical conductivity of the supernatant reached 100 μS / cm.

A 1.02-fold molar amount of strontium hydroxide octahydrate was added to the titanium hydroxide-containing titanium, and the mixture was placed in a stainless steel reaction vessel and replaced with nitrogen gas.

Further, distilled water was added so as to be 0.3 mol / L in terms of SrTiO ₃ . The slurry was heated to 90 ° C. at 30 ° C./hour in a nitrogen atmosphere, and the reaction was carried out for 5 hours after reaching 90 ° C. After the reaction, the mixture was cooled to room temperature, the supernatant was removed, washing with pure water was repeated, and then filtration was performed with Nuche. The obtained cake was dried to obtain strontium titanate particles 15.

<Manufacturing example of toner particles 1>
(Preparation process of water-based medium 1)
14.0 parts of sodium phosphate (12-hydrate manufactured by Rasa Industries, Ltd.) was added to 1000.0 parts of ion-exchanged water in the reaction vessel, and the mixture was kept warm at 65 ° C. for 1.0 hour while purging with nitrogen.

T. K. Using a homomixer (manufactured by Tokushu Kagaku Kogyo Co., Ltd.), a calcium chloride aqueous solution in which 9.2 parts of calcium chloride (dihydrate) is dissolved in 10.0 parts of ion-exchanged water is batched while stirring at 12000 rpm. It was charged to prepare an aqueous medium containing a dispersion stabilizer. Further, 10% by mass hydrochloric acid was added to the aqueous medium to adjust the pH to 5.0 to obtain the aqueous medium 1.

(Hydrolysis step of organosilicon compound for surface layer)
60.0 parts of ion-exchanged water was weighed in a reaction vessel equipped with a stirrer and a thermometer, and the pH was adjusted to 3.0 using 10% by mass of hydrochloric acid. This was heated with stirring to bring the temperature to 70 ° C. Then, 40.0 parts of methyltriethoxysilane, which is an organosilicon compound for the surface layer, was added and stirred for 2 hours or more for hydrolysis. The end point of hydrolysis was visually confirmed to be one layer without separation of oil and water, and the mixture was cooled to obtain a hydrolyzed solution 1 of an organosilicon compound for the surface layer.

(Preparation step of polymerizable monomer composition)
・ Styrene: 60.0 parts ・ C.I. I. Pigment Blue 15: 3: 6.5 parts The above material is put into an attritor (manufactured by Mitsui Miike Machinery Co., Ltd.), and further dispersed with zirconia particles having a diameter of 1.7 mm at 220 rpm for 5.0 hours to obtain a pigment. A dispersion was prepared. The following materials were added to the pigment dispersion.
-Styline: 20.0 parts-n-butyl acrylate: 20.0 parts-Crosslinking agent (divinylbenzene): 0.3 parts-Saturated polyester resin: 5.0 parts (propylene oxide-modified bisphenol A (2 mol adduct) Polycondensate of terephthalic acid (molar ratio 10:12), glass transition temperature Tg = 68 ° C., weight average molecular weight Mw = 10000, molecular weight distribution Mw / Mn = 5.12)
-Fischer-Tropsch wax (melting point 78 ° C): 7.0 parts Keep this warm at 65 ° C, and T.I. K. A polymerizable monomer composition was prepared by uniformly dissolving and dispersing at 500 rpm using a homomixer (manufactured by Tokushu Kagaku Kogyo Co., Ltd.).

(Granulation process)
The temperature of the water-based medium 1 was set to 70 ° C., and T.I. K. The polymerizable monomer composition was put into the aqueous medium 1 while keeping the rotation speed of the homomixer at 12000 rpm, and 9.0 parts of t-butylperoxypivalate as a polymerization initiator was added. Granulation was carried out for 10 minutes while maintaining 12000 rpm with the stirring device as it was.

(Polymerization process)
After the granulation step, the stirrer is replaced with a propeller stirring blade, and the polymerization is carried out at 70 ° C. for 5.0 hours while stirring at 150 rpm, and the temperature is raised to 85 ° C. and heated for 2.0 hours to carry out the polymerization reaction. Was performed to obtain core particles. When the temperature of the slurry was cooled to 55 ° C. and the pH was measured, the pH was 5.0. While stirring was continued at 55 ° C., 20.0 parts of the hydrolyzed solution 1 of the organosilicon compound for the surface layer was added to start the surface layer formation of the toner. After holding for 30 minutes as it was, the slurry was adjusted to pH = 9.0 for completion of condensation using an aqueous sodium hydroxide solution and held for another 300 minutes to form a surface layer.

(Washing and drying process)
After the completion of the polymerization step, the slurry of toner particles is cooled, hydrochloric acid is added to the slurry of toner particles, the pH is adjusted to 1.5 or less, the mixture is left to stir for 1 hour, and then solid-liquid separated with a pressure filter to separate the toner cake. Got This was reslurried with ion-exchanged water to form a dispersion liquid again, and then solid-liquid separation was performed with the above-mentioned filter. The reslurry and solid-liquid separation were repeated until the electric conductivity of the filtrate became 5.0 μS / cm or less, and then the solid-liquid separation was finally performed to obtain a toner cake.

The obtained toner cake was dried by an air flow dryer Flash Jet Dryer (manufactured by Seishin Enterprise Co., Ltd.), and further, fine coarse powder was cut using a multi-division classifier utilizing the Coanda effect to obtain toner particles 1. The drying conditions were adjusted so that the blowing temperature was 90 ° C., the dryer outlet temperature was 40 ° C., and the toner cake supply speed was such that the outlet temperature did not deviate from 40 ° C. according to the water content of the toner cake.

Silicon mapping was performed in the cross-sectional TEM observation of the toner particles 1, and the ratio of the number of division axes in which the silicon atom was present on the surface layer and the thickness of the surface layer of the toner particles containing the organic silicon polymer was 2.5 nm or less was determined. It was confirmed that it was 20.0% or less. Also in the following examples, the surface layer containing the organosilicon polymer has silicon atoms present in the surface layer by the same silicon mapping, and the ratio of the number of division axes having a thickness of 2.5 nm or less on the surface layer is 20.0%. I confirmed that it was as follows.

<Manufacturing example of toner particles 2 to 12>
Toner particles 2 to 12 are produced in the same manner as in the production example of toner particles 1 except that the conditions for adding the hydrolyzed liquid in the (polymerization step) and the holding time after addition are changed as shown in Table 2. did. The pH of the slurry was adjusted with hydrochloric acid and an aqueous solution of sodium hydroxide.

<Manufacturing example of toner particles 13-18>
Toner particles 13 to 18 were produced in the same manner as in the production example of toner particles 1 except that the surface organosilicon compound used in (hydrolysis step of surface organosilicon compound) was changed as shown in Table 2.

<Manufacturing example of toner particles 19 to 23>
Toner particles 19 to 23 were produced in the same manner as in the production example of toner particles 1 except that the conditions for adding the hydrolyzed liquid in (polymerization step) were changed as shown in Table 2.

<Manufacturing example of toner particles 24>
The toner particles 24 were produced in the same manner as in the production example of the toner particles 1 except that the conditions for adding the hydrolyzed liquid in the (polymerization step) and the holding time after the addition were changed as shown in Table 2.

<Manufacturing example of toner particles 25>
(The step of hydrolyzing the organosilicon compound for the surface layer) was not performed. Instead, 15 parts of methyltriethoxysilane, an organosilicon compound for the surface layer, was added as a monomer (in the step of preparing the polymerizable monomer composition).

In the (polymerization step), after cooling to 70 ° C. and measuring the pH, no hydrolyzed solution was added. While stirring was continued at 70 ° C., the slurry was adjusted to pH = 9.0 for completion of condensation using an aqueous sodium hydroxide solution and held for another 300 minutes to form a surface layer.

Other than that, the toner particles 25 were produced by the same method as in the production example of the toner particles 1.

<Manufacturing example of toner particles 26>
In the production example of the toner particles 25, the amount of methyltriethoxysilane added in (the step of preparing the polymerizable monomer composition) was changed to 30 parts.

Other than that, the toner particles 26 were produced by the same method as in the production example of the toner particles 25.

<Manufacturing example of toner particles 27>
The toner particles 27 were produced in the same manner as the toner particles 1 except that the conditions for adding the hydrolyzed liquid in the (polymerization step) and the holding time after the addition were changed as shown in Table 2.

<Manufacturing example of toner particles 28>
In the production example of the toner particles 25, the amount of methyltriethoxysilane added in (the step of preparing the polymerizable monomer composition) was changed to 8 parts.

Other than that, the toner particles 28 were produced by the same method as in the production example of the toner particles 25.

<Manufacturing example of toner particles 29>
(Production example of binder resin 1)
・ Terephthalic acid 25.0 mol%
・ Adipic acid 13.0 mol%
-Trimellitic acid 8.0 mol%
33.0 mol% of bisphenol derivative represented by the above formula (1)
(Propylene oxide 2.5 mol adduct)
21.0 mol% of bisphenol derivative represented by the above formula (1)
(Ethylene oxide 2.5 mol adduct)
A total of 100 parts of the acid component and alcohol component shown above and 0.02 part of tin 2-ethylhexanoate as an esterification catalyst are charged in a 4-neck flask, and a decompression device, a water separation device, a nitrogen gas introduction device, and a temperature measurement device are charged. And a stirring device was attached, and the reaction was carried out by raising the temperature to 230 ° C. in a nitrogen atmosphere. After completion of the reaction, the product was taken out from the container, cooled and pulverized to obtain a binder resin 1.

(Production example of binder resin 2)
The binder resin 2 was prepared in the same manner as the binder resin 1 except that the monomer composition ratio and the reaction temperature were changed as follows.
・ Terephthalic acid 50.0 mol%
・ Adipic acid is not used ・ Trimellitic acid 3.0 mol%
47.0 mol% of bisphenol derivative represented by the above formula (1)
(Propylene oxide 2.5 mol adduct)
-The bisphenol derivative represented by the above formula (1) is not used (ethylene oxide 2.5 mol adduct).
・ Reaction temperature 190 ℃
Bundling resin 1: 70.0 parts Bundling resin 2: 30.0 parts Magnetic iron oxide particles: 90.0 parts (average particle size 0.14 μm, Hc = 11.5 kA / m, σs = 84.0 Am ² / kg, σr = 16.0 Am ² / kg)
Fischer-Tropsch wax (melting point 105 ° C): 2.0 parts Charge control agent 1 (structural formula below): 2.0 parts

In the formula, tBu represents a tert-butyl group.

After the above materials were premixed with a Henschel mixer, they were melt-kneaded by a twin-screw kneading extruder having three kneading portions and a screw portion 1 as shown in FIG. At this time, the heating temperature of the first kneading section near the supply port is 110 ° C., the heating temperature of the second kneading section is 130 ° C., the heating temperature of the third kneading section is 150 ° C., and the rotation speed of the paddle is 200 rpm. It was melt-kneaded. The obtained kneaded product was cooled, roughly pulverized with a hammer mill, and then pulverized with a fine pulverizer using a jet stream. The obtained finely pulverized powder was classified using a multi-division classifier utilizing the Coanda effect to obtain toner particles 29 having a weight average particle size of 7.0 μm.

[Example 1]
<Manufacturing example of toner 1>
Toner 1 was prepared by externally adding toner particles 1 with the combinations shown in Table 3. As for the method of external addition, 100 parts of the toner particles were mixed with the external addition agent of the number of copies shown in Table 3 in SUPERMIXER PICCOLO SMP-2 (manufactured by Kawata Co., Ltd.) at 3000 rpm for 20 minutes. Then, the toner 1 was obtained by sieving with a mesh having an opening of 150 μm. The obtained toner 1 was evaluated for physical properties and the following durability. The evaluation results are shown in Table 4.

<Toner durability evaluation by LBP>
As an image forming apparatus, a commercially available laser printer LBP-7700C (manufactured by Canon Inc.) was used, the process speed was changed to 360 mm / sec, and a modification was made to enable output with a single toner cartridge. A cyan cartridge filled with the toner 1 (200 g) was attached to the cyan station of the printer, and an image output test was carried out.

In a low-temperature and low-humidity environment (temperature 15.0 ° C., humidity 10% RH), the following evaluation was performed after printing 10,000 images with an initial printing rate of 1%. As the durable paper, LETTER size XEROX4200 paper (manufactured by XEROX, 75 g / m ² ) was used.

(Solid uniformity)
A solid black image was output, and uneven density of the image was visually observed and evaluated based on the following criteria. As the evaluation paper, LETTER size XEROX4200 paper (manufactured by XEROX, 75 g / m ² ) was used. Regarding the image output after endurance, the image was output by replacing it with a new drum unit. When density unevenness was observed, the image density of that portion was measured, and the density difference Δ from the three-point average density of the upper end, the center, and the lower end of the image was measured. An X-Rite 508 spectrodensitometer was used to measure the image density.
Rank A: The uniformity of the image is very excellent, and the image is extremely clear.
Rank B: The image has excellent uniformity and is a good image.
Rank C: The image quality is practically acceptable.
Rank D: The image has poor uniformity and is not preferable.

(Drum scratch)
After the durable image was drawn, the state of scratches on the photoconductor (drum) was evaluated.
Rank A: No scratches are seen by visual observation.
Rank B: There are minor scratches of 1 μm or less, but there is no problem with the image.
Rank C: There are scratches of 2 μm or less, but there is no problem with the image.
Rank D: This is an unfavorable image with scratches of 2 μm or more.

In a high-temperature and high-humidity environment (temperature 30.0 ° C., humidity 80% RH), the following evaluation was performed after printing 10,000 initial images with a print rate of 1%. As the durable paper, LETTER size XEROX4200 paper (manufactured by XEROX, 75 g / m ² ) was used.

(Fog)
A solid white image was output at a process speed of 120 mm / sec. An Amber filter was set in "REFLEC TIMETER MODEL TC-6DS" (manufactured by Tokyo Denshoku Co., Ltd.), and the reflectance (%) of the non-image portion of the printout image was measured. The obtained reflectance was evaluated using a numerical value (%) obtained by subtracting the reflectance (%) of the unused printout paper (standard paper) measured in the same manner. The smaller the value, the more the image fog is suppressed. As the evaluation paper, a LETTER size HP ColorLaser Photo Paper, Glossy (manufactured by HP, 220 g / m ² ) was used. Regarding the image output after endurance, the image was output by replacing it with a new drum unit.
Rank A: The difference in reflectance is less than 0.5.
Rank B: The difference in reflectance is 0.5 or more and less than 1.0.
Rank C: The difference in reflectance is 1.0 or more and less than 2.0.
Rank D: The difference in reflectance is 2.0 or more.

[Examples 2-37]
<Manufacturing example of toners 2 to 37>
With the combinations shown in Table 3, each toner particle was externally added to prepare toners 2 to 37. As for the method of external addition, 100 parts of the toner particles were mixed with the external addition agent of the number of copies shown in Table 3 in SUPERMIXER PICCOLO SMP-2 (manufactured by Kawata Co., Ltd.) at 3000 rpm for 20 minutes. Then, the toner was sieved with a mesh having an opening of 150 μm to obtain toners 2 to 37. The obtained toner was evaluated for physical properties and the above-mentioned durability. The evaluation results are shown in Table 4.

[Comparative Examples 1 to 8]
<Manufacturing examples of comparative toners 1 to 8>
With the combinations shown in Table 3, each toner particle was externally added to prepare comparative toners 1 to 8. As for the method of external addition, 100 parts of the toner particles were mixed with the external addition agent of the number of copies shown in Table 3 in SUPERMIXER PICCOLO SMP-2 (manufactured by Kawata Co., Ltd.) at 3000 rpm for 20 minutes. Then, it was sieved with a mesh having an opening of 150 μm to obtain comparative toners 1 to 8. Table 4 shows the evaluation results of the obtained toner.

In Table 3, DHT-4A (manufactured by Kyowa Chemical Industry Co., Ltd .: number average particle diameter 0.4 μm, BET specific surface area 10 m ² / g) was used as the hydrotalcite particles, and RXY300 (Nippon Aerosil Co., Ltd.) was used as the fumed silica particles. Made) was used.

As is clear from Table 4, "Examples 1 to 37", which are the toners of the present invention, suppress damage to the photosensitive drum and have excellent development characteristics (flow) as compared with "Comparative Examples 1 to 8". (Characteristics and chargeability) are maintained. That is, according to the present invention, it is possible to provide a toner that suppresses damage to peripheral members such as a photosensitive drum and maintains excellent development characteristics even in long-term durable use.

1: Screw part 2: 1st kneading part 3: 2nd kneading part 4: 3rd kneading part 5: Motor

Claims (13)

Toner containing toner particles and an external additive,
The external additive contains strontium titanate particles, and the strontium titanate particles have an average number of primary particles of 10 nm or more and 60 nm or less.
The strontium titanate particles are 39.700 ° ± 0.150 ° and 46.200 ° in the X-ray diffraction spectrum of CuKα obtained in the range where 2θ is 10 ° or more and 90 ° or less when the Bragg angle is θ. It has a peak in the range of ± 0.150 ° and has a peak.
When the area of the peak at 39.700 ° ± 0.150 ° is Sa and the area of the peak at 46.200 ° ± 0.150 ° is Sb, Sb / Sa is 1.80 or more and 2.30. Is below
A toner characterized by having a Martens hardness of 130 MPa or more and 1100 MPa or less when measured under the condition of a maximum load of 2.0 × 10 ^-4 N. The toner according to claim 1, wherein the maltens hardness when measured under the condition of a maximum load of 9.8 × 10 ^-4 N is 5 MPa or more and 100 MPa or less. The toner particle has a surface layer containing an organosilicon polymer, and the number of carbon atoms directly bonded to the silicon atom of the organosilicon polymer is 1 or more and 3 or less, according to claim 1 or 2. toner. The toner according to claim 3, wherein the fixation rate of the organosilicon polymer is 90% or more. The toner according to claim 3 or 4, wherein the organosilicon polymer has a partial structure represented by the formula (1).
R-SiO _3/2 formula (1)
(R indicates a hydrocarbon group having 1 or more carbon atoms and 6 or less carbon atoms.) The toner according to claim 5, wherein R is a hydrocarbon group having 1 or more carbon atoms and 3 or less carbon atoms. The toner according to any one of claims 1 to 6, wherein the toner particles have positively charged particles on the surface, and the number average particle diameter of the positively charged particles is 5 nm or more and 500 nm or less. The toner according to claim 7, wherein the positively charged particles are hydrotalcite. The toner according to any one of claims 1 to 8, wherein the strontium titanate particles have an Sr / Ti (molar ratio) of 0.70 or more and 0.85 or less. The toner according to any one of claims 1 to 9, wherein the primary particles of the strontium titanate particles have an average circularity of 0.700 or more and 0.920 or less. The strontium titanate particles have a methanol concentration of 60% by volume or more and 95% by volume or less when the transmittance of light having a wavelength of 780 nm is 50% in a wettability test with a mixed solvent of methanol / water. The toner according to any one of 10. The invention according to any one of claims 1 to 11, wherein the coverage of the toner surface with strontium titanate particles measured by an X-ray photoelectron spectroscope is 5.0 area% or more and 20.0 area% or less. Toner. The toner according to any one of claims 1 to 12, wherein the content of the strontium titanate particles is 0.05 parts by mass or more and 5.0 parts by mass or less with respect to 100 parts by mass of the toner particles.

Images