JP7614929B2 - Toner and its manufacturing method - Google Patents

Description

The present invention relates to a toner used in recording methods that utilize electrophotography, electrostatic recording, and toner jet recording, and a method for producing the toner.

In recent years, the printer market has seen a demand for smaller printer bodies, higher image quality for printed materials, and an increase in the number of pages that can be printed per toner cartridge.
In order to satisfy the above requirements, it is necessary to prevent contamination of charging members such as the charging roller and carrier, and one method for achieving this is to suppress the liberation of external additives from the toner surface.
For example, in Patent Document 1, toner particles to which a large amount of hydrophobic silica particles are externally added are heated in a suspended state, so that a large amount of hydrophobic silica is embedded in the surface of the toner particles. In Patent Document 2, an organosilicon polymer network having fine irregularities is formed on the surface of the toner particles as an external additive. In addition, as in Patent Document 3, an organosilicon fine particle having hollow particles that are hemispherical is used as an external additive to make it difficult for the external additive to come off from the surface of the toner particles.
However, in any of the methods described in Patent Documents 1 to 3, when the toner has a high circularity, for example, an average circularity of more than 0.970, the residual toner remaining after the transfer of the latent image on the drum cannot be sufficiently removed by the cleaning blade, and therefore, due to contamination of the charging roller downstream of the cleaning process, it may be difficult to obtain sufficient output image quality, particularly in cartridges with long life.

JP 2007-279239 A JP 2018-194836 A JP 2008-257217 A

The toner of the present invention can suppress the release or burial of external additives from the toner surface, and is easy to clean with a blade even for toners with high circularity, providing a toner that provides excellent image quality over a long period of time.

The present invention relates to a toner having toner particles containing a binder resin and an organosilicon polymer,
the toner particles have doughnut-shaped protrusions of the organosilicon polymer,
The protrusion is
(i) formed from the organosilicon polymer,
(ii) when the outer diameter of the doughnut shape is R (nm), the R is 40 nm or more and 200 nm or less,
(iii) when the inner diameter of the doughnut shape is r (nm), R−r is 10 nm or more and 70 nm or less;
(iv) the height is 10 nm or more and 50 nm or less;
(v) there are an average of 50 to 1,000 particles per 1.8 μm square on the surface of the toner particle,
The toner has an average circularity of 0.970 or more and 1.000 or less.
The present invention also provides a method for producing the toner having the above-mentioned configuration,
The present invention relates to a method for producing a toner, comprising the steps of: condensing a compound of the following formula (1) in a slurry of toner base particles dispersed in an aqueous medium using magnesium hydroxide fine particles; and dissolving and removing the magnesium hydroxide fine particles.

（式（１）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 formula (1), R ₁ represents a hydrocarbon group having 1 to 6 carbon atoms, and R ₂ , R ₃ and R ₄ each independently represent a halogen atom, a hydroxyl group, an acetoxy group or an alkoxy group.)

The toner of the present invention can suppress the release or burial of external additives on the toner surface that occurs with durability deterioration, and can be easily blade cleaned even with toners with high circularity. Furthermore, it has superior low-temperature fixability compared to toners covered with the same amount of external additives.

FIG. 2 is an explanatory diagram of the doughnut-shaped convex shape formed by the organosilicon polymer according to the present invention. FIG. 2 is an electron microscope photograph of the surface of a toner particle according to the present invention.

In this disclosure, unless otherwise specified, the expressions "xx or more and xx or less" and "xx to xx" that express a numerical range refer to a numerical range that includes the lower and upper limit endpoints.

The toner of the present invention is a toner having toner particles containing a binder resin and an organosilicon polymer, and the average circularity of the toner is 0.970 or more and 1.000 or less. The toner particles having such a high average circularity have doughnut-shaped convex portions of the organosilicon polymer. The organosilicon polymer referred to here corresponds to what is generally referred to in the same industry as an external additive.

Conventionally, toners with a high average circularity have had problems with blade cleaning. However, the inventors have discovered that by having this doughnut-shaped organosilicon polymer protrusion, this conventional problem can be solved. The reasons for this are believed to be as follows.

First, in the conventional combination of toner particles with a high average circularity and an external additive, the contact between the photoreceptor surface and the toner was through point contact between the photoreceptor surface and the spherical or irregularly shaped external additive on the toner surface. Therefore, the rolling resistance between the photoreceptor surface and the toner was low, so when the toner came into contact with the cleaning blade, the toner rolled, making it difficult to scrape off such toner. However, since the toner of the present invention has a donut-shaped convex portion, the contact between the photoreceptor surface and the convex portion present on the toner surface becomes a surface contact, and the contact area is significantly increased. As a result, the rolling resistance between the photoreceptor surface and the toner is high, so even if the toner comes into contact with the cleaning blade, the toner does not roll and can be scraped off. Therefore, even with a toner with a high average circularity, it is possible to suppress contamination of the charging member that comes into contact with the photoreceptor.

Furthermore, the doughnut-shaped protrusions have a larger contact area than conventional point-contact external additives and protrusions, and therefore more charging sites during frictional charging. Toners with a high degree of circularity have good fluidity, so friction between toner particles is likely to occur. As a result, toners with a high average degree of circularity and doughnut-shaped protrusions improve the charging start-up, which improves the suppression of image fogging after storage in a high-temperature, high-humidity environment.

As a result of extensive research by the inventors, the following five characteristics of the doughnut-shaped protrusion are necessary to obtain the above-mentioned effects. Note that FIG. 1 shows the outer diameter R, inner diameter r, and height of the shape of the protrusion, which will be described later.

(i) The first feature is that the convex portions are formed of an organosilicon polymer. The organosilicon polymer is preferably a condensate of at least one organosilicon polymerizable monomer selected from the group consisting of organosilicon represented by the following formula (I). The condensate of the organosilicon polymerizable monomer represented by the following formula (I) has crosslinking properties, which further suppresses migration of the organosilicon polymer to the charging member.
Ra(n)-Si-Rb(4-n) (I)
In formula (I), each Ra independently represents a halogen atom or an alkoxy group (preferably having 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms), each Rb independently represents an alkyl group (preferably having 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms), an alkenyl group (preferably having 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms), an aryl group (preferably having 6 to 14 carbon atoms, more preferably 6 to 10 carbon atoms), an acyl group (preferably having 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms), or a methacryloxyalkyl group (preferably a methacryloxypropyl group). n represents an integer of 2 or 3.

The organosilicon polymerizable monomer represented by formula (I) includes various bifunctional and trifunctional silane compounds.

Specific examples of bifunctional silane compounds include dimethyldimethoxysilane and dimethyldiethoxysilane.

Examples of trifunctional silane compounds include the following compounds:

Trifunctional methylsilane compounds such as methyltrimethoxysilane, methyltriethoxysilane, methyldiethoxymethoxysilane, and methylethoxydimethoxysilane; trifunctional silane compounds such as ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, hexyltrimethoxysilane, and hexyltriethoxysilane; trifunctional phenylsilane compounds such as phenyltrimethoxysilane and phenyltriethoxysilane; vinyl Trifunctional vinyl silane compounds such as trimethoxysilane and vinyltriethoxysilane; trifunctional allyl silane compounds such as allyltrimethoxysilane, allyltriethoxysilane, allyldiethoxymethoxysilane, and allylethoxydimethoxysilane; trifunctional gamma-methacryloxypropyl silane compounds such as gamma-methacryloxypropyltrimethoxysilane, gamma-methacryloxypropyltriethoxysilane, gamma-methacryloxypropyldiethoxymethoxysilane, and gamma-methacryloxypropylethoxydimethoxysilane; etc.

The organosilicon polymer has a structure in which silicon atoms and oxygen atoms are bonded alternately, the organosilicon polymer having a T3 unit structure represented by RaSiO3 _/2 , where Ra represents an alkyl group or phenyl group having from 1 to 6 carbon atoms, and in ^29Si -NMR measurement of the organosilicon polymer, the ratio of the area of the peak derived from silicon having the T3 unit structure to the total area of the peaks derived from all silicon elements contained in the organosilicon polymer is preferably from 0.65 to 0.80, since this can suppress a decrease in charge amount in a high-temperature, high-humidity environment and excessive charging in a low-temperature, low-humidity environment and improves the suppression of fogging in non-image areas, and is more preferably from 0.65 to 0.75.

(ii) The second characteristic is that when the outer diameter of the doughnut-shaped protrusion is R (nm), R is 40 nm or more and 200 nm or less. As a result of extensive research by the inventors, it has been found that by setting R within the above range, it is possible to achieve both the liberation of the doughnut-shaped protrusion and the cleaning properties of the toner. The reason for this is believed to be as follows.

When the radius of the doughnut-shaped protrusions on the toner surface becomes larger, the fluidity of the toner decreases. This increases the external force that the toner receives when it is stirred in the developing machine, making the protrusions more likely to come off. Furthermore, when the radius of the radius becomes smaller, it becomes impossible to obtain an area for sufficient surface contact between the doughnut-shaped protrusions and the photoconductor, and toner with a high degree of circularity cannot be scraped off with the blade.

(iii) The third is characterized in that, when the inner diameter of the doughnut shape is r (nm), the difference between R and r (R-r) is 10 nm or more and 70 nm or less. The detailed judgment method will be described in the measurement method described later, but r is the distance from the center of the protrusion (where no organosilicon polymer is present) that can be confirmed as a doughnut-shaped organosilicon polymer from the backscattered electron image and secondary electron image of the SEM to the inside of the thickness of the organosilicon polymer of the doughnut-shaped protrusion. As a result of intensive research, the inventors have also found that by setting R-r within the above range, both the liberation of the protrusion and the cleaning properties of the toner can be achieved. A smaller value of R-r, that is, a smaller thickness of the doughnut shape, means that the contact area between the drum and the doughnut-shaped protrusions becomes smaller, making it impossible to obtain sufficient rolling resistance. In addition, when R-r becomes larger, the contact area between the toners also increases, so the fluidity of the toner decreases, and the liberation and burial of the protrusions become more likely to occur, causing contamination of the member.

In addition, it is preferable that the coefficient of variation of the average value of R-r is 0.20 or less, since this effect can be further improved.

As a result of intensive research by the present inventors, it is preferable that r is 30 nm or more and 130 nm or less from the viewpoint of fixability. When r is less than 30 nm, the number of places from which the molten material seeps out during heat fixing is smaller than when the inner radius r is large, so the area in contact with the paper is reduced. As a result, it is believed that the fixability has deteriorated. Furthermore, when r exceeds 130 nm, R is inevitably large, and although the fixability is good, it is not preferable from the viewpoint of the effect on the peeling of the convex and the cleaning ability. Furthermore, it is also preferable from the viewpoint of fixability that the ratio of r to R of the convex (r/R) is 0.20 or more and 0.60 or less. The smaller r/R indicates the smaller the hole, and there are fewer holes from which the molten material seeps out during heat fixing, and the area in contact with the paper is reduced, which may result in poor fixability. Furthermore, the larger the r/R, the larger the hole, so when the outer radius R is large, the contact area with the toner surface is reduced, so the convex is easily peeled off, which may contaminate the developer carrier such as the carrier or the developing roller.

(iv) The fourth feature is that the height of the doughnut-shaped protrusions is 10 nm or more and 50 nm or less. By keeping the height of the protrusions within the above range, it is possible to suppress the protrusions from becoming detached.

(v) The fifth characteristic is that the number of doughnut-shaped protrusions is an average of 50 to 1,000 per 1.8 μm square on the surface of the toner particle.

The method for counting the number of protrusions within the above range will be specified in the specific measurement method described later, but if the number of protrusions is less than 50, it is difficult to improve the cleaning performance because the probability of the doughnut-shaped protrusions coming into contact with the photoreceptor is low. Also, if the number of protrusions exceeds 1,000, the R of the protrusions becomes smaller than 40 nm, making it difficult to improve the cleaning performance.

Next, we will explain the raw materials that can be used in the toner of the present invention.

Examples of binder resins contained in toner particles include polystyrene, styrene-based copolymers which are copolymers of styrene and other vinyl monomers, acrylic resins, silicone resins, polyester resins, etc. These resins are used alone or in combination.

As the main component of the binder resin, polyester resin and styrene copolymer are preferred in terms of developability and fixability. In the present invention, the main component means that the content is 50% by mass to 100% by mass (preferably 80% by mass to 100% by mass, more preferably 90% by mass to 100% by mass).

The polyester resin is not particularly limited, and known polyester resins can be used. Monomers include divalent or higher alcohol monomer components, and acid monomer components such as divalent or higher carboxylic acids, divalent or higher carboxylic acid anhydrides, and divalent or higher carboxylic acid esters.

The styrene copolymer may be crosslinked with a crosslinking agent. The crosslinking agent used is a compound having two or more polymerizable double bonds.

A colorant may be used in the toner. Examples of colorants include various conventionally known dyes, pigments, and other known colorants.

Examples of magenta coloring pigments include C.I. Pigment Red 3, 5, 17, 22, 23, 38, 41, 112, 122, 123, 146, 149, 150, 178, 179, 190, and 202, and C.I. Pigment Violet 19 and 23. These pigments may be used alone, or a dye and a pigment may be used in combination.

Examples of cyan coloring pigments include C.I. Pigment Blue 15, 15:1, and 15:3, and copper phthalocyanine pigments in which 1 to 5 phthalimidomethyl groups are substituted on the phthalocyanine skeleton.

Examples of yellow coloring pigments include C.I. Pigment Yellow 1, 3, 12, 13, 14, 17, 55, 74, 83, 93, 94, 95, 97, 98, 109, 110, 154, 155, 166, 180, and 185.

Black colorants that can be used include carbon black, aniline black, acetylene black, titanium black, and those toned to black using the yellow/magenta/cyan colorants listed above.

The colorant content is preferably 3.0 parts by mass or more and 15.0 parts by mass or less per 100.0 parts by mass of binder resin.

The toner can also be used as a magnetic toner, in which case the following magnetic materials are used: iron oxides such as magnetite, maghemite, ferrite, or iron oxides including other metal oxides; metals such as Fe, Co, Ni, or alloys of these metals with metals such as Al, Co, Cu, Pb, Mg, Ni, Sn, Zn, Sb, Ca, Mn, Se, Ti, and mixtures thereof.

The magnetic material is preferably used in the range of 10 to 200 parts by weight, more preferably 20 to 150 parts by weight, per 100 parts by weight of the binder resin.

The toner may contain a release agent. Examples of the release agent include hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, and paraffin wax; oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax; block copolymers of aliphatic hydrocarbon waxes; ester waxes mainly composed of fatty acid esters such as carnauba wax, sazol wax, and montan acid ester wax; and partially or completely deoxidized fatty acid esters such as deoxidized carnauba wax, partial esters of fatty acids and polyhydric alcohols such as behenic acid monoglyceride; and methyl ester compounds having a hydroxyl group obtained by hydrogenating vegetable oils and fats.

The content of the release agent is preferably 2.5 parts by mass or more and 40.0 parts by mass or less in total, and more preferably 3.0 parts by mass or more and 15.0 parts by mass or less, per 100 parts by mass of the binder resin. In addition, these release agents may be used alone or in combination of two or more kinds, and it is preferable to use a combination of a hydrocarbon wax and an ester wax from the viewpoint of fixation.

A charge control agent may be used in the toner. The charge control agent can keep the chargeability of the toner stable. Examples of charge control agents include various charge control agents that have been used in toner applications.

The toner can be used as a one-component or two-component developer in either development method. When used as a two-component developer, the average particle size of the carrier is preferably 10 to 100 μm, more preferably 20 to 50 μm. When preparing a two-component developer by mixing these carriers and toner, the toner concentration in the developer is preferably about 2 to 15% by mass.

Next, we will explain the method for producing the toner of the present invention.

The toner of the present invention can be produced by known production methods such as pulverization and polymerization of toner base particles (toner particles before the formation of the protrusions of the organosilicon polymer). However, the toner base particles obtained by either method must be produced by a method that includes a step of condensing the compound of the following formula (1) after the toner base particles are dispersed in an aqueous medium with magnesium hydroxide fine particles to form a slurry of the toner base particles, and a step of dissolving and removing the magnesium hydroxide fine particles.

（式（１）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 formula (1), R ₁ represents a hydrocarbon group having 1 to 6 carbon atoms, and R ₂ , R ₃ and R ₄ each independently represent a halogen atom, a hydroxyl group, an acetoxy group or an alkoxy group.)

Magnesium hydroxide can be subjected to coupling treatment with bifunctional or trifunctional silane compounds. By adding a bifunctional or trifunctional silane compound to the surface of the toner mother particle in the presence of magnesium hydroxide, the silane compound attached to the surface of the toner mother particle or the surface of the mother particle and magnesium hydroxide selectively gathers at the water/magnesium hydroxide interface, and the magnesium hydroxide surface is selectively subjected to coupling treatment. After the coupling treatment of magnesium hydroxide is completed, the magnesium hydroxide can be removed with an acid to obtain a toner having donut-shaped protrusions of organosilicon polymer attached thereto. Figure 2 is an electron microscope photograph of the toner particle surface after the above manufacturing process, showing that donut-shaped protrusions of organosilicon polymer are formed. It should be noted that donut-shaped particles cannot be formed even if the same type of silane compound is added to a dispersion of magnesium hydroxide and subjected to a coupling reaction. It is believed that this is because the adhesion surface between the toner mother particle and magnesium hydroxide is not subjected to coupling treatment, and the donut-shaped protrusions are formed by removing the magnesium hydroxide.

The amount of the silane compound to be added is preferably 50 to 700 molar parts, more preferably 70 to 300 molar parts, relative to 100 molar parts of magnesium hydroxide. The primary particle size of the magnesium hydroxide is preferably 10 to 200 nm, more preferably 30 to 100 nm, in order to obtain the desired doughnut shape.

When toner particles obtained by the pulverization method are added to an aqueous medium containing magnesium hydroxide to form a slurry, it is preferable to heat the toner particles once to a temperature equal to or higher than the glass transition temperature in order to increase the circularity of the toner.

In addition, for toner applications, it is preferable that the size of the toner base particles to which magnesium hydroxide is attached has a number average particle size of 3 μm or more and 10 μm or less.

The following describes a specific example of the toner manufacturing method of the present invention. As a specific example, because it is necessary to make a slurry using magnesium hydroxide, a method of manufacturing toner particles using a suspension polymerization method in which toner particles are manufactured in advance in an aqueous medium will be used.

(Preparation of aqueous medium)
Magnesium hydroxide is used in the form of fine particles in an aqueous medium having a pH of 8.5 or more. The pH can be adjusted by adding an acid such as hydrochloric acid to an aqueous alkali solution such as sodium hydroxide, sodium hydrogen phosphate, sodium phosphate, sodium hydrogen carbonate, or sodium carbonate.

(Preparation of polymerizable monomer composition)
First, a polymerizable monomer composition is prepared containing a polymerizable monomer and, if necessary, other additives such as a colorant and wax. Any of the colorants, waxes, etc. that can be used are publicly known.

The colorant may be dispersed in advance in the polymerizable monomer using a medium stirring mill or the like and then mixed with the other compositions, or may be dispersed simultaneously with the other compositions or after mixing with the other compositions.

(Granulation process)
The polymerizable monomer composition is charged into an aqueous medium and dispersed to form droplets of the polymerizable monomer composition. In the granulation step, a known agitator having a high shear force can be used.

(Polymerization process)
The droplets of the polymerizable monomer composition obtained as described above are introduced into a polymerization process to obtain polymer particles (toner base particles). A general stirring tank capable of controlling the temperature can be used for the polymerization process.

The polymerization temperature is usually 40°C or higher, preferably 50 to 90°C. The polymerization temperature may be constant throughout, but may be increased in the latter half of the polymerization process to obtain the desired molecular weight distribution.

(Distillation process)
In order to remove volatile impurities such as unreacted polymerizable monomers and by-products, after the polymerization is completed, a distillation operation may be performed on the polymerization slurry containing the toner base particles obtained from the polymerization step to distill off a part of the aqueous medium. The distillation step may be performed under normal pressure or reduced pressure.

(Organosilicon Polymer Treatment Step)
The magnesium hydroxide is subjected to coupling treatment with an organosilicon polymer by adding a bifunctional and/or trifunctional silane compound, and the condensation pH is from 8.5 to 11.0, more preferably from 9.5 to 10.5.

(Washing and magnesium hydroxide removal process, solid-liquid separation (filtration) process, and drying process)
In order to remove magnesium hydroxide adhering to the surface of the toner base particles, the dispersion of the toner base particles may be treated with an acid or alkali. After this, the toner particles are separated from the liquid phase by a general solid-liquid separation method, but in order to completely remove the acid or alkali and the magnesium hydroxide component dissolved therein, water may be added again to wash the toner particles. This washing process is repeated several times, and after sufficient washing, solid-liquid separation is again performed to obtain toner particles. The obtained toner particles are dried by a known drying means if necessary.

(Classification process)
The toner particles thus obtained may be classified, if necessary, using an air classifier or the like to separate and remove particles that fall outside the desired particle size distribution.

(External Addition Process)
If necessary, an external additive may be added to the toner particles obtained as described above. The external addition may be performed by a known method. In order to improve the flowability, chargeability, cleaning property, etc., a fluidizing agent, a cleaning aid, etc. may be added as an external additive other than the silica particles as necessary.

Other external additives include inorganic fine particles such as silica fine particles, alumina fine particles, and titanium oxide fine particles.

The total content of these various external additives is preferably 0.05 parts by mass or more and 2.00 parts by mass or less per 100 parts by mass of toner particles. The type and content of the external additives can be appropriately selected as long as the effects of the present invention are not impaired. In addition, various external additives may be used in combination.

The following describes how to measure various physical properties related to the present invention.

<Measurement of Number Average Particle Size D1 of Inorganic Fine Particles>
The particle size distribution of inorganic fine particles in an aqueous medium is calculated using a dynamic light scattering Microtrac particle size distribution analyzer [UPA-150] (Nikkiso Co., Ltd.). Measurements are performed while controlling the temperature of the cell so that the temperature of the aqueous medium used in the measurement is the same as that of the measurement cell. Particle size measurements are performed at 60°C.
(1) After pouring 3.0 g of RO water into the cell, perform a back-ground check to confirm that the sample loading is 0.0010 or less.
(2) After putting 3.0 g of RO water into the cell, perform Set Zero.
The ero condition is time: 60 s.
(3) Enter the following conditions: The refractive indexes shown below are for the magnesium hydroxide microparticles according to the present invention and for the hydroxyapatite microparticles used for comparison in the examples.
Measurement time: 30 s, number of measurements: 2 Particle conditions: Transmissive, refractive index: 1.62, shape: non-spherical, density: 3.17
Solvent conditions: WATER selected Refractive index: 1.56 (magnesium hydroxide), 1.33 (hydroxyapatite)
Viscosity at high temperature: 0.797 (30℃), Viscosity at low temperature: 1.002 (20℃)
Display setting: Select Standard Distribution display: Select Volume (4) Place 3.0 g of the aqueous medium containing inorganic fine particles in the measurement cell and start measurement.
(5) The measurement data is analyzed using dedicated software provided with the device to calculate the number average particle size (D1).

<Method of Identifying Organosilicon Polymer Fine Particles>
The organosilicon polymer particles contained in the toner can be identified by a combination of shape observation by SEM and elemental analysis by EDS.

Using a scanning electron microscope "S-4800" (product name; manufactured by Hitachi, Ltd.), the toner is observed at a maximum magnification of 50,000 times. The focus is set on the surface of the toner particles, and the external additives are observed. EDS analysis is performed on each particle of the external additive, and based on the presence or absence of a Si element peak, it is determined whether or not the analyzed particle is an organosilicon polymer microparticle.

When the toner contains both organosilicon polymer microparticles and silica microparticles, the organosilicon polymer microparticles are identified by comparing the ratio of the elemental content of Si and O (atomic %) (Si/O ratio) with a standard.

EDS analysis is performed under the same conditions on samples of organosilicon polymer microparticles and silica microparticles to obtain the elemental content (atomic %) of Si and O.

Let the Si/O ratio of the organosilicon polymer microparticles be A, and the Si/O ratio of the silica microparticles be B. Select the measurement conditions under which A is significantly greater than B.

Specifically, the standard is measured 10 times under the same conditions, and the arithmetic mean values of A and B are obtained. The measurement conditions are selected such that the obtained mean value is A/B>1.1.

If the Si/O ratio of the microparticles being judged is on the A side of [(A+B)/2], the microparticles are judged to be organosilicon polymer microparticles.

Tospearl 120A (Momentive Performance Materials Japan, LLC) is used as a sample of organosilicon polymer microparticles, and HDK V15 (Asahi Kasei) is used as a sample of silica microparticles.

<Method of observing a cross section of a toner using a scanning transmission electron microscope (STEM)>
A cross section of a toner to be observed by a scanning transmission electron microscope (STEM) is prepared as follows: When organic or inorganic fine particles are externally added to the toner, the organic or inorganic fine particles are removed by the following method or the like, and the resulting toner is used as a sample.

160 g of sucrose (Kishida Chemical) is added to 100 mL of ion-exchanged water, and dissolved in a hot water bath to prepare a concentrated sucrose solution. 31 g of the concentrated sucrose solution and 6 mL of Contaminon N (a 10% aqueous solution of a neutral detergent for cleaning precision measuring instruments, pH 7, consisting of a nonionic surfactant, anionic surfactant, and organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) are placed in a centrifuge tube (50 mL capacity). 1.0 g of toner is added to this, and the toner clumps are loosened with a spatula or the like. The centrifuge tube is shaken at 300 spm (strokes per minute) for 20 minutes in a shaker (AS-1N, sold by AS ONE Corporation). After shaking, the solution is transferred to a glass tube for a swing rotor (50 mL) and separated in a centrifuge (H-9R, manufactured by Kokusan Co., Ltd.) at 3,500 rpm for 30 minutes.

This operation separates the toner particles from the external additives. Visually check that the toner particles and the aqueous solution are sufficiently separated, and collect the toner particles that have separated into the top layer with a spatula or similar. The collected toner particles are filtered through a vacuum filter, and then dried in a dryer for at least one hour to obtain a sample for measurement. This operation is carried out multiple times to ensure the required amount.

In addition, whether or not the convex portion contains an organosilicon polymer is confirmed by combining elemental analysis using energy dispersive X-ray analysis (EDS).

The toner is spread onto a cover glass (Matsunami Glass Co., Ltd., square cover glass; square No. 1) in a single layer, and an osmium plasma coater (Filgen Co., Ltd., OPC80T) is used to apply an Os film (5 nm) and a naphthalene film (20 nm) to the toner as a protective film.

Next, a PTFE tube (outer diameter 3 mm (inner diameter 1.5 mm) x 3 mm) is filled with photocurable resin D800 (JEOL Ltd.), and the cover glass is gently placed on top of the tube in such a direction that the toner is in contact with the photocurable resin D800. In this state, light is irradiated to harden the resin, and then the cover glass and tube are removed to form a cylindrical resin with toner embedded in the outermost surface.

Ultrasonic ultramicrotome (Leica, UC7) is used to cut at a cutting speed of 0.6 mm/s from the outermost surface of the cylindrical resin to the length of the toner radius (for example, 4.0 μm when the weight average particle size (D4) is 8.0 μm) to expose the cross section of the center of the toner.

Next, the toner is cut to a thickness of 100 nm to produce a thin sample of the toner cross section. By cutting in this manner, a cross section of the central part of the toner can be obtained.

A JEM-2800 manufactured by JEOL was used as the scanning transmission electron microscope (STEM). The probe size of the STEM was 1 nm, and images were acquired with an image size of 1024 x 1024 pixels. In addition, images were acquired by adjusting the contrast of the Detector Control panel for the bright field image to 1425, the brightness to 3750, and the contrast of the Image Control panel to 0.0, the brightness to 0.5, and the gamma to 1.00.

The image magnification is 100,000 times, and the image is captured so that it covers approximately one-quarter to one-half of the circumference of the cross section of one toner particle.

The obtained STEM image is analyzed using image processing software (ImageJ (available from https://imagej.nih.gov/ij/)) to measure the convex portions containing the organosilicon polymer. The measurement is performed on 30 convex portions randomly selected from the STEM image.

Whether or not the convex portions contain organosilicon polymers will be confirmed by a combination of elemental analysis using a scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDS).

First, use the line drawing tool (select Segmented line in the Strong tab) to draw a line along the periphery of the toner base particle. In areas where the protruding parts of the organosilicon polymer are embedded in the toner base particle, connect the lines smoothly, assuming that they are not embedded.

Use that line as a basis to convert it into a horizontal image (select Selection on the Edit tab, change the line width to 500 pixels in properties, then select Selection on the Edit tab and use Strengthener).

The following measurements are carried out on one of the convex portions containing the organosilicon polymer in the horizontal image.

A normal line is drawn along the circumference at the portion where the convex portion and the toner base particle form a continuous interface, and the value of the normal line that is the maximum length at the convex portion is the convex height of the organosilicon polymer being measured.

This measurement is performed on 30 randomly selected convex portions, and the arithmetic mean of each measurement is taken as the height of the convex portion.

<Method of measuring the outer diameter R and inner diameter r of primary particles of organosilicon polymers and method of measuring the number of organosilicon polymers>
The elemental analysis is performed in combination with a scanning electron microscope "S-4800" (product name: manufactured by Hitachi, Ltd.) and energy dispersive X-ray analysis (EDS).

To measure the outer diameter R and inner diameter r, 100 complex particles are randomly photographed in a field of view magnified up to 50,000 times.

100 organosilicon polymer microparticles are randomly selected from the captured image, and the outer diameter of the primary particles is measured at 15° intervals based on the horizontal direction, and this is taken as the outer diameter R. Similarly, the inner diameter r is measured at 15° intervals based on the horizontal direction, and this is taken as the inner diameter r. The coefficient of variation of R-r is calculated by finding the difference between R and r measured at the same angle, and using the values measured at a total of 12 points per particle in the range of 0° to 180°.

The observation magnification is adjusted appropriately depending on the size of the organosilicon polymer microparticles.

The images used to count the number of doughnut-shaped organosilicon polymers on the toner surface are taken at random with a field of view magnified 50,000 times. The number of objects present in a 1.8 μm square area of each of these images is counted, and the number of doughnut-shaped organosilicon polymers per image is calculated.

<Method of measuring weight average particle diameter (D4) and number average particle diameter (D1)>
The weight average particle diameter (D4) and number average particle diameter (D1) of the toner are calculated as follows. The measurement device used is a precision particle size distribution measurement device using the pore electrical resistance method, "Coulter Counter Multisizer 3" (registered trademark, manufactured by Beckman Coulter, Inc.), equipped with a 100 μm aperture tube. The measurement conditions are set and the measurement data is analyzed using the accompanying dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (manufactured by Beckman Coulter, Inc.). The measurement is performed with an effective measurement channel count of 25,000 channels.

The electrolyte solution used for the measurements is one in which special grade sodium chloride is dissolved in ion-exchanged water to give a concentration of approximately 1% by mass, for example "ISOTON II" (manufactured by Beckman Coulter).

Before performing measurements and analysis, the dedicated software was configured as follows:

On the "Change standard measurement method (SOMME)" screen of the dedicated software, set the total count in control mode to 50,000 particles, the number of measurements to 1, and the Kd value to the value obtained using "standard particle 10.0 μm" (manufactured by Beckman Coulter). Press the "Threshold/noise level measurement button" to automatically set the threshold and noise level. Also, set the current to 1600 μA, the gain to 2, the electrolyte to ISOTON II, and check "Flush aperture tube after measurement."

In the "Pulse to particle size conversion setting" screen of the dedicated software, set the bin interval to logarithmic particle size, the particle size bin to 256 particle size bins, and the particle size range to 2 μm to 60 μm.

The specific measurement method is as follows.
(1) Pour about 200 ml of the electrolyte solution into a 250 ml round-bottom glass beaker for use with the Multisizer 3, set it on the sample stand, and stir the stirrer rod counterclockwise at 24 revolutions per second. Then, remove dirt and air bubbles from inside the aperture tube using the "aperture flush" function of the dedicated software.
(2) About 30 ml of the aqueous electrolyte solution is placed in a 100 ml flat-bottom glass beaker, and about 0.3 ml of a dilution of "Contaminon N" (a 10% aqueous solution of a neutral detergent for cleaning precision measuring instruments, pH 7, made of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) diluted about 3 times by mass with ion-exchanged water is added thereto as a dispersant.
(3) Prepare an ultrasonic dispersion device "Ultrasonic Dispersion System Tetra150" (manufactured by Nikkaki Bios Co., Ltd.) that has two built-in oscillators with an oscillation frequency of 50 kHz and a phase shift of 180 degrees and an electrical output of 120 W. Place about 3.3 L of ion-exchanged water in the water tank of the ultrasonic dispersion device, and add about 2 ml of Contaminon N to this 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 surface of the electrolytic solution in the beaker is maximized.
(5) In a state where the electrolyte solution in the beaker in (4) is irradiated with ultrasonic waves, about 10 mg of toner is added little by little to the electrolyte solution and dispersed. Then, ultrasonic dispersion treatment is continued for another 60 seconds. During ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted so as to be 10°C or higher and 40°C or lower.
(6) Using a pipette, the electrolyte aqueous solution (5) in which the toner is dispersed is dropped into the round-bottom beaker (1) placed in the sample stand, and the measurement concentration is adjusted to about 5%. Then, measurements are continued until the number of particles measured reaches 50,000.
(7) The measurement data is analyzed using the dedicated software provided with the device to calculate the weight average particle diameter (D4) and number average particle diameter (D1). Note that when the dedicated software is set to graph/volume %, the "average diameter" on the "analysis/volume statistics (arithmetic mean)" screen is the weight average particle diameter (D4), and when the dedicated software is set to graph/number %, the "average diameter" on the "analysis/number statistics (arithmetic mean)" screen is the number average particle diameter (D1).

<Method for measuring average circularity>
The average circularity of the toner particles was measured using a flow type particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation) under the measurement and analysis conditions used during calibration.

The specific measurement method is as follows. First, about 20 ml of ion-exchanged water from which impurities such as solids have been removed is placed in a glass container. About 0.2 ml of a dilution of "Contaminon N" (a 10% aqueous solution of a neutral detergent for cleaning precision measuring instruments with a pH of 7, consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) diluted about three times by mass with ion-exchanged water is added to the container. About 0.02 g of the measurement sample is then added, and the dispersion is performed for 2 minutes using an ultrasonic disperser to obtain a dispersion for measurement. At this time, the dispersion is appropriately cooled so that the temperature of the dispersion is 10°C or higher and 40°C or lower. As the ultrasonic disperser, a tabletop ultrasonic cleaner disperser (e.g., "VS-150" (manufactured by Vervoclear Co., Ltd.) with an oscillation frequency of 50 kHz and an electrical output of 150 W is used, a predetermined amount of ion-exchanged water is placed in the water tank, and about 2 ml of the Contaminon N is added to the water tank.

For the measurements, the flow type particle image analyzer equipped with the objective lens "LUCPLFLN" (magnification 20x, numerical aperture 0.40) was used, and the particle sheath "PSE-900A" (manufactured by Sysmex Corporation) was used as the sheath liquid. The dispersion liquid prepared according to the above procedure was introduced into the flow type particle image analyzer, and 2,000 toner particles were measured in HPF measurement mode and total count mode. The binarization threshold for particle analysis was set to 85%, and the analyzed particle diameter was limited to a circle equivalent diameter of 1.977 μm or more and less than 39.54 μm, and the average circularity of the toner particles was calculated.

When performing the measurement, automatic focus adjustment is performed using standard latex particles (e.g., "RESEARCH AND TEST PARTICLES Latex Microsphere Suspensions 5100A" manufactured by Duke Scientific, diluted with ion-exchanged water) before starting the measurement. After that, it is preferable to perform focus adjustment every two hours from the start of the measurement.

In the examples of this application, a flow-type particle image analyzer was used that had been calibrated by Sysmex Corporation and had a calibration certificate issued by Sysmex Corporation. Measurements were performed under the same measurement and analysis conditions as when the calibration certificate was received, except that the particle diameters analyzed were limited to a circle equivalent diameter of 1.977 μm or more and less than 39.54 μm.

<Method for identifying the composition and ratio of constituent compounds of organosilicon polymer fine particles>
NMR is used to identify the composition and ratio of the constituent compounds of the organosilicon polymer particles contained in the toner.

When the toner contains silica fine particles in addition to the organosilicon polymer fine particles, 1 g of the toner is placed in a vial and dissolved and dispersed in 31 g of chloroform. The toner is dispersed by treating with an ultrasonic homogenizer for 30 minutes to produce a dispersion liquid.
Ultrasonic treatment device: Ultrasonic homogenizer VP-050 (manufactured by Taitec Co., Ltd.)
Microchip: Step type microchip, tip diameter φ2mm
Position of tip of microchip: center of glass vial, at a height of 5 mm from the bottom of the vial. Ultrasonic conditions: intensity 30%, 30 minutes. During this time, ultrasonic waves are applied while cooling the vial with ice water to prevent the temperature of the dispersion from increasing.

The dispersion is transferred to a glass tube (50 mL) for a swing rotor and centrifuged at 58.33 ^S for 30 minutes in a centrifuge (H-9R; manufactured by Kokusan Co., Ltd.). After centrifugation, the lower layer in the glass tube contains silica particles with a high specific gravity. The chloroform solution containing the upper layer of organosilicon polymer particles is collected and the chloroform is removed by vacuum drying (40°C/24 hours) to prepare a sample.

Using the above sample or organosilicon polymer fine particles, the abundance ratio of the constituent compounds in the organosilicon polymer fine particles and the proportion of T3 unit structures in the organosilicon polymer fine particles are measured and calculated by solid-state ²⁹ Si-NMR.

First, the hydrocarbon group represented by Ra is confirmed by ¹³ C-NMR.

< ^13C -NMR (solid) measurement conditions>
Equipment: JEOL RESONANCE JNM-ECX500II
Sample tube: 3.2 mm diameter
Sample: Sample or organosilicon polymer fine particles Measurement temperature: Room temperature Pulse mode: CP/MAS
Measurement nuclear frequency: 123.25MHz ( ^13C )
Reference substance: Adamantane (external standard: 29.5ppm)
Sample rotation speed: 20 kHz
Contact time: 2 ms
Delay time: 2s
Number of accumulations: 1024 Using the above method, the hydrocarbon group represented by R a above is confirmed based on the presence or absence of signals due to groups such as methyl groups (Si-CH ₃ ), ethyl groups (Si-C ₂ H ₅ ), propyl groups (Si-C ₃ H ₇ ), butyl groups (Si-C ₄ H ₉ ), pentyl groups (Si-C ₅ H ₁₁ ), hexyl groups (Si-C ₆ H ₁₃ ) and phenyl groups (Si-C ₆ H ₅ - ⁾ bonded to silicon atoms.

On the other hand, in solid-state ²⁹ Si-NMR, peaks are detected in different shift regions depending on the structure of the functional groups bonded to the Si of the constituent compounds of the organosilicon polymer fine particles.

The position of each peak can be identified using a standard sample to identify the structure that bonds to Si. In addition, the abundance ratio of each constituent compound can be calculated from the obtained peak area. The ratio of the peak area of the T3 unit structure to the total peak area can be calculated.

The specific conditions for the solid-state ²⁹ Si-NMR measurement are as follows:
Equipment: JNM-ECX5002 (JEOL RESONANCE)
Temperature: Room temperature Measurement method: DDMAS method ²⁹ Si 45°
Sample tube: Zirconia 3.2 mm diameter
Sample: Powdered sample filled in test tube Sample rotation speed: 10 kHz
relaxation delay: 180s
Scan: 2000
After the above measurement, the peaks of multiple silane components with different substituents and bonding groups of the sample or organosilicon polymer microparticles are separated into the following X1, X2, X3, and X4 structures by curve fitting, and the peak areas of each are calculated.

The following X3 structure is the T3 unit structure in the present invention.
X1 structure: (Ri) (Rj) (Rk) SiO _1/2 (A1)
X2 structure: (Rg) (Rh)Si(O _1/2 ) ₂ (A2)
X3 structure: RmSi(O _1/2 ) ₃ (A3)
X4 structure: Si(O _1/2 ) ₄ (A4)

In the formulas (A1), (A2), and (A3), Ri, Rj, Rk, Rg, Rh, and Rm represent an organic group such as a hydrocarbon group having 1 to 6 carbon atoms, a halogen atom, a hydroxy group, an acetoxy group, or an alkoxy group bonded to silicon.

If it is necessary to confirm the structure in more detail, it may be identified by the results of ¹ H-NMR measurement in addition to the results of ¹³ C-NMR and ²⁹ Si-NMR measurement.

The following describes the manufacturing examples and working examples of the toner of the present invention. In the following, "parts" refers to parts by weight.

Toner Production Example 1
<Preparation of aqueous medium>
0.79 parts of magnesium chloride (Kishida Chemical, hexahydrate) was added to 1000.0 parts of ion-exchanged water in a reaction vessel, and the mixture was kept warm at 45°C for 1.0 hours while purging with nitrogen. Using a T.K. homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), an aqueous solution of sodium hydroxide in which 0.46 parts of sodium hydroxide (Kishida Chemical) was dissolved was added to 10.0 parts of ion-exchanged water over 30 minutes while stirring at 12000 rpm, to prepare an aqueous medium containing magnesium hydroxide fine particles. Furthermore, an aqueous solution of sodium hydroxide was added, and the pH was adjusted to 9.5, to obtain an aqueous medium.

<Preparation process of polymerizable monomer composition>
Styrene: 45.5 parts C.I. Pigment Blue 15:3: 5.0 parts The above materials were put into an attritor (manufactured by Mitsui Miike Chemical Engineering Co., Ltd.), and further dispersed for 5.0 hours at 220 rpm using zirconia particles having a diameter of 1.7 mm to prepare a pigment dispersion. Next, the following materials were added to the pigment dispersion.
Styrene: 9.0 parts; n-butyl acrylate: 21.2 parts; crosslinking agent (divinylbenzene): 0.4 parts; saturated polyester resin: 3.8 parts (polycondensate of propylene oxide modified bisphenol A (2 mole adduct) and terephthalic acid (molar ratio 9:13), glass transition temperature Tg = 70°C, weight average molecular weight Mw = 12000, molecular weight distribution Mw/Mn = 5.2)
Fischer-Tropsch wax (melting point 78° C.): 10.0 parts This was kept at 65° C. and uniformly dissolved and dispersed at 500 rpm using a T. K. Homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare a polymerizable monomer composition.

<Granulation process>
While maintaining the temperature of the aqueous medium at 70° C. and the rotation speed of the stirring device at 12,000 rpm, the polymerizable monomer composition was charged into the aqueous medium, and 8.9 parts of t-butyl peroxypivalate as a polymerization initiator was added. Granulation was continued for 10 minutes while maintaining the stirring device at 12,000 rpm.

<Polymerization step>
The agitator was changed from the high-speed agitator to a propeller agitation blade, and polymerization was carried out for 4.0 hours while stirring at 150 rpm and maintaining the temperature at 70° C., and then the temperature was raised to 95° C. and heated for 5.0 hours to carry out a polymerization reaction, thereby obtaining toner base particle slurry dispersion 1.

<Organosilicon Polymer Protrusion Forming Step>
(First process)
A reaction vessel equipped with a thermometer and a stirrer was charged with 360.0 parts of water, and 15.0 parts of hydrochloric acid with a concentration of 5.0% by mass was added to obtain a homogeneous solution. 136.0 parts of methyltrimethoxysilane was added to the solution while stirring at a temperature of 25° C., and the mixture was stirred for 5 hours, and then filtered to obtain a transparent reaction solution 1 containing a silanol compound or a partial condensate thereof.

(Second step)
Toner base particle slurry dispersion 1 was kept at 50° C. and adjusted to pH 9.5 and solids concentration 30% using a 5% by weight aqueous sodium carbonate solution and ion-exchanged water. 4.0 parts of reaction solution 1 obtained in the first step were added to 100 parts of the adjusted slurry dispersion 1, and a condensation reaction was carried out with stirring at 50° C. for 3 hours, yielding organosilicon polymer-attached slurry dispersion 1 in which an organosilicon polymer was attached to the surfaces of the toner base particles.

<Cleaning and drying process>
After the convex formation step was completed, the organosilicon polymer attached slurry dispersion 1 was cooled, hydrochloric acid was added to the dispersion to adjust the pH to 7.0 or less, and the dispersion was left to stand with stirring for 1 hour, after which solid-liquid separation was carried out using a pressure filter. After that, washing was again repeated using ion exchanged water and the pressure filter until the electrical conductivity of the filtrate reached 5.0 μS/cm or less, and finally solid-liquid separation was carried out to obtain toner particle cake 1.

The resulting toner particle cake 1 was dried using a flash jet dryer (manufactured by Seishin Enterprises), and then fine and coarse powder was removed using a multi-division classifier that utilizes the Coanda effect to obtain toner particles 1.

The drying conditions were a blowing temperature of 90°C, a dryer outlet temperature of 40°C, and the supply speed of the toner particle cake 1 was adjusted according to the moisture content of the toner particle cake 1 so that the outlet temperature did not deviate from 40°C.

The physical properties of the obtained toner particles 1 are shown in Table 2.

Toner Production Example 2
Toner particles 2 were obtained in the same manner as in Toner Production Example 1, except that the <Preparation of aqueous medium> in Toner Production Example 1 was changed as follows, and the pH during acid washing in the <Washing and drying step> was changed to 1.5, as shown in Table 1.

The physical properties of the obtained toner particles 2 are shown in Table 2.

<Preparation of aqueous medium>
1.82 parts of sodium phosphate (made by Rasa Kogyo Co., Ltd., 12-hydrate) was added to 1000.0 parts of ion-exchanged water in a reaction vessel, and the mixture was kept at 55°C for 1.0 hours while purging with nitrogen. A calcium chloride aqueous solution in which 1.20 parts of calcium chloride (dihydrate) was dissolved in 10.0 parts of ion-exchanged water was added at once using a T.K. homomixer (made by Tokushu Kika Kogyo Co., Ltd.) while stirring at 12000 rpm, to prepare an aqueous medium containing hydroxyapatite microparticles. Furthermore, 10% by mass of hydrochloric acid was added to the aqueous medium, and the pH was adjusted to 6.0 to obtain an aqueous medium.

Toner Production Example 3
<Cleaning process>
The same process up to the polymerization step of Toner Production Example 1 was carried out to obtain toner base particle slurry dispersion 3. The obtained toner base particle slurry dispersion 3 was cooled to room temperature, adjusted to pH 1.5 or less using hydrochloric acid, stirred for 1 hour, and filtered under pressure to obtain a toner base particle cake. Thereafter, washing was repeated using ion-exchanged water and a pressure filter until the electrical conductivity of the filtrate became 5.0 μS/cm or less, to obtain toner base particle cake 3.

<Reslurry process>
0.79 parts of magnesium chloride (Kishida Chemical, hexahydrate) was added to 1000.0 parts of ion-exchanged water in a reaction vessel, and the mixture was kept at 45°C for 1.0 hours while purging with nitrogen. Using a T.K. homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), while stirring at 12000 rpm, an aqueous solution of sodium hydroxide in which 0.46 parts of sodium hydroxide (Kishida Chemical) was dissolved was added to 10.0 parts of ion-exchanged water over 30 minutes to prepare an aqueous medium containing magnesium hydroxide fine particles. Furthermore, an aqueous solution of sodium hydroxide was added, and the pH was adjusted to 9.5 to obtain an aqueous medium.

The above aqueous medium was stirred at 12,000 rpm using a T.K. Homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), while the above toner base particle cake 3 was added so that the solid content concentration was 33.0%, thereby obtaining a prepared slurry dispersion liquid 3.

<Organosilicon Polymer Protrusion Forming Step>
(First process)
A reaction vessel equipped with a thermometer and a stirrer was charged with 360.0 parts of water, and 15.0 parts of hydrochloric acid with a concentration of 5.0% by mass was added to obtain a homogeneous solution. 136.0 parts of methyltrimethoxysilane was added to the solution while stirring at a temperature of 25° C., and the mixture was stirred for 5 hours, and then filtered to obtain a transparent reaction solution 3 containing a silanol compound or a partial condensate thereof.

(Second step)
To 100 parts of the prepared slurry dispersion 3, 4.0 parts of reaction solution 1 obtained in the first step were added, and a condensation reaction was carried out with stirring at 50°C for 3 hours, yielding organosilicon polymer-attached slurry dispersion 3 in which the organosilicon polymer was attached to the surfaces of the toner base particles.

<Cleaning and drying process>
After the convex formation step was completed, the organosilicon polymer attached slurry dispersion 3 was cooled, hydrochloric acid was added to the dispersion to adjust the pH to 7.0 or less, and the dispersion was left to stand with stirring for 1 hour, after which solid-liquid separation was carried out using a pressure filter. After that, washing was again repeated using ion exchanged water and the pressure filter until the electrical conductivity of the filtrate reached 5.0 μS/cm or less, and finally solid-liquid separation was carried out to obtain a toner particle cake 3.

The resulting toner particle cake 3 was dried using a flash jet dryer (manufactured by Seishin Enterprises), and then fine and coarse powder was removed using a multi-division classifier that utilizes the Coanda effect to obtain toner particles 3.

The drying conditions were a blowing temperature of 90°C, a dryer outlet temperature of 40°C, and the supply speed of the toner particle cake 3 was adjusted according to the moisture content of the toner particle cake 3 so that the outlet temperature did not deviate from 40°C.

The conditions for the obtained toner particles 3 are shown in Table 1, and the physical properties are shown in Table 2.

Toner Production Examples 4 to 23
The same procedures as in Toner Production Example 3 were carried out under the conditions shown in Table 1 from the <Organosilicon Polymer Protrusion Forming Step> onwards to obtain Toner Particles 4 to 23. The physical properties of Toner Particles 4 to 23 thus obtained are shown in Table 2.

Toner Production Example 24
<Drying process>
The same process as in Toner Production Example 3 was carried out up to the washing step, thereby obtaining a toner base particle cake 24. The obtained toner base particle cake 24 was dried using an air flow dryer, a flash jet dryer (manufactured by Seishin Enterprise Co., Ltd.), and further, fine and coarse powder was removed using a multi-division classifier utilizing the Coanda effect, thereby obtaining toner base particles 24.

The drying conditions were a blowing temperature of 90°C, a dryer outlet temperature of 40°C, and the supply speed of the toner base particle cake 24 was adjusted according to the moisture content of the toner base particle cake 24 so that the outlet temperature did not deviate from 40°C.

<Additive Fixation Treatment>
2.0 parts of sol-gel silica fine particles having a number average particle size of 70 nm and surface-treated with 25% by mass of hexamethyldisilazane were added to 100 parts of the obtained toner base particles 24, and mixed in a Henschel mixer (FM-10 type, manufactured by Mitsui Miike Chemical Engineering Co., Ltd.) to obtain toner particles 24 having external additives attached thereto. The temperature of the Henschel mixer was adjusted so that the temperature of the mixture was 30° C.

The resulting toner particles 24 with the external additives attached were treated with hot air at 280°C in a surface modification machine, Meteor Rainbow (manufactured by Nippon Pneumatic Mfg. Co., Ltd.), to fix the external additives.

Then, classification was performed using an air classifier (Elbow Jet PURO, Matsubo Co., Ltd.) to obtain toner particles 24.

The physical properties of the resulting toner particles 24 are shown in Table 2.

Toner Production Example 25
<Preparation of irregularly shaped silica particles>
A dispersion was prepared by dispersing 5.00 g of fumed silica (Tokuyama Corp., product name QS-30, BET specific surface area 302 m ² /g, average primary particle diameter 7 nm) and 500 g of methanol in methanol using a homogenizer output of 60 W for a dispersion time of 30 minutes.

500.5 g of the prepared dispersion and 75 g of 15% by mass ammonia water as the charged ammonia water were placed in a 2 L four-neck flask and stirred at 30°C. 100 g of tetramethoxysilane as the alkoxysilane and 100 g of 5% by mass ammonia water as the added ammonia water were each dropped into the liquid independently. The dropping speed was adjusted so that it was completed in 60 minutes, and an irregular silica microparticle dispersion was obtained.

<Preparation of Toner Particles>
The washing step was carried out in the same manner as in Toner Production Example 3 to obtain toner base particles 25. The obtained toner base particles 25 were added to an irregular silica fine particle dispersion liquid while stirring at 12,000 rpm with a T. K. Homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) so that the solid content concentration became 33.0%, thereby obtaining a slurry dispersion liquid 25 to which irregular silica fine particles were attached.

The resulting slurry dispersion 25 with the irregularly shaped silica microparticles attached was filtered under pressure, and then repeatedly washed using ion-exchanged water and pressure filtration until the electrical conductivity of the filtrate was 5.0 μS/cm or less, toner particle cake 25 was obtained.

The obtained toner particle cake 25 was dried in a flash jet dryer (manufactured by Seishin Enterprises), and further fine and coarse powder was removed using a multi-division classifier utilizing the Coanda effect to obtain toner particles 25. The drying conditions were an inlet temperature of 90°C, a dryer outlet temperature of 40°C, and the supply speed of the toner particle cake 25 was adjusted according to the moisture content of the toner particle cake 25 so that the outlet temperature did not deviate from 40°C.

The physical properties of the resulting toner particles 25 are shown in Table 2.

Toner Production Example 26
<Toner base particle manufacturing process>
Styrene and n-butyl acrylate copolymer (resin A) 81.2 parts (copolymerization mass ratio; styrene:n-butyl acrylate:divinylbenzene=72:28:0.5, peak molecular weight (Mp=22,000)
Saturated polyester resin: 3.8 parts (polycondensate of propylene oxide modified bisphenol A (2 mole adduct) and terephthalic acid (molar ratio 9:13), glass transition temperature Tg = 70°C, weight average molecular weight Mw = 12000, molecular weight distribution Mw/Mn = 5.2)
Fischer-Tropsch wax (melting point 78 ° C.): 10.0 parts C.I. Pigment Blue 15:3: 5.0 parts The above formulation was mixed in a Henschel mixer (FM-75 type, manufactured by Mitsui Miike Chemical Engineering Co., Ltd.), and then melt-kneaded in a twin-screw kneader (PCM-30 type, manufactured by Ikegai Iron Works Co., Ltd.) set at a temperature of 120 ° C. The kneaded product obtained was cooled and coarsely crushed to 1 mm or less with a hammer mill to obtain a coarsely crushed product. The obtained coarsely crushed product was crushed twice with a mechanical crusher (T-250, manufactured by Turbo Kogyo Co., Ltd.) to obtain a resin particle crushed product.

The obtained resin particle pulverized material was subjected to a spheroidizing process while being classified in a mechanical surface modification device (Faculty F-400 type, manufactured by Hosokawa Micron Corporation) by rotating the dispersion rotor with a stator at 10,000 rpm and the classification rotor at 6,000 rpm, to obtain toner base particles 26.

<Slurrying step>
1.82 parts of sodium phosphate (12-hydrate) was added to 1000.0 parts of ion-exchanged water in a reaction vessel, and the mixture was kept at 55°C for 1.0 hours while purging with nitrogen. A calcium chloride aqueous solution in which 1.2 parts of calcium chloride (Kishida Chemical) was dissolved in 10.0 parts of ion-exchanged water was added at once using a T.K. homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) while stirring at 12000 rpm, to prepare an aqueous medium containing hydroxyapatite microparticles. Furthermore, 10% hydrochloric acid was added to adjust the pH to 6.0, and an aqueous medium was obtained.

The toner base particles 26 obtained through the above toner particle manufacturing process were added to the above aqueous medium so that the solids concentration was 33.0%, and a slurry was obtained.

<Organosilicon Polymer Protrusion Forming Step>
(First process)
A reaction vessel equipped with a thermometer and a stirrer was charged with 360.0 parts of water, and 15.0 parts of hydrochloric acid with a concentration of 5.0% by mass was added to obtain a homogeneous solution. 136.0 parts of methyltrimethoxysilane was added to the solution while stirring at a temperature of 25° C., and the mixture was stirred for 5 hours, and then filtered to obtain a transparent reaction liquid containing a silanol compound or a partial condensate thereof.

(Second step)
To this, 4.0 parts of the reaction liquid obtained in the first step was added to 100 parts of the slurry, and the condensation reaction was carried out with stirring at 40° C. for 5 hours, yielding a slurry with the organosilicon polymer attached.

<Cleaning and drying process>
After the convex forming process was completed, the toner particle slurry was cooled, and hydrochloric acid was added to the toner particle slurry to adjust the pH to 7.0 or less, and the slurry was left to stand with stirring for 1 hour, and then the slurry was subjected to solid-liquid separation using a pressure filter to obtain a toner cake. This was reslurried with ion-exchanged water to make a dispersion again, and then the solid-liquid separation was performed using the above-mentioned filter. The reslurry and solid-liquid separation were repeated until the electrical conductivity of the filtrate became 5.0 μS/cm or less, and finally the solid-liquid separation was performed to obtain a toner cake.

The obtained toner cake was dried in a flash jet dryer (manufactured by Seishin Enterprises), and further fine and coarse powder was removed using a multi-division classifier utilizing the Coanda effect to obtain toner particles 26. The drying conditions were an inlet temperature of 90°C, a dryer outlet temperature of 40°C, and the toner cake supply speed was adjusted according to the moisture content of the toner cake so that the outlet temperature did not deviate from 40°C.

The physical properties of the resulting toner particles 26 are shown in Table 2.

Example 1
As shown in Table 2, the resulting toner particles 1 were confirmed to have doughnut-shaped organosilicon polymer protrusions.

The obtained toner particles 1 were used as toner 1 and the following evaluations were carried out.

A modified Canon laser beam printer LBP9600C was used for the evaluation. The toner was removed from the black cartridge and replaced with 300 g of Toner 1 for the evaluation.

(Image Evaluation)
[Evaluation of cleaning ability]
A Canon laser beam printer LBP9600C was modified to enable printing using only the cyan station. 300 g of the toner to be evaluated was filled into a toner cartridge for the LBP9600C, and the toner cartridge was left in a low-temperature, low-humidity environment (15° C./10% RH) for 24 hours.

Next, the toner cartridge after being left for 24 hours was attached to the LBP9600C, and a halftone image with a toner loading of 0.25 mg/ ^cm2 was output on a receiver paper. After that, an image with a printing ratio of 2.0% was printed out on up to 10,000 sheets of A4 paper in the lateral direction. The image output was performed in a low temperature and low humidity environment (15°C/10% RH), which is a condition in which the cleaning blade becomes harder and therefore the ability to follow the photoreceptor drum decreases, making cleaning more difficult. After outputting 10,000 sheets, a halftone image with a toner loading of 0.25 mg/ ^cm2 was output on a receiver paper. The initial image before the durability evaluation and the image after outputting 10,000 sheets (after durability) were evaluated based on the following criteria.

As the image receiving paper, CS-680 (basis weight 68 g/m ² , sold by Canon Marketing Japan Inc.) was used.
A: No cleaning failure on the halftone image, no stain on the charging roller.
B: No cleaning failure on halftone image, charging roller dirty.
C: Very faint vertical lines are observed on halftone images as a result of poor cleaning.
D: One or more clear vertical lines are observed on the halftone image as cleaning defects.

In this invention, a grade of C or higher is considered good.

[Evaluation of component contamination]
Under a low temperature and low humidity environment (15°C, relative humidity 10%), 10,000 sheets of images with a printing rate of 4.0% were output with a 4 second intermittent time for every two sheets. When the toner ran out during the printing, 300 g of toner was added. After the durability evaluation, the charging roller was removed from the toner cartridge. The charging roller was removed from a new process cartridge (commercially available), and the charging roller that had been used for durability was attached, and a halftone image was output. The uniformity of the halftone image was visually evaluated, and the charging member contamination was evaluated.

It is known that if the charging member is contaminated, uneven charging occurs on the photosensitive drum, resulting in uneven density in halftone images. A grade of C or above was deemed good.

(Evaluation Criteria)
A: Image density is uniform without unevenness. B: Image density is slightly uneven. C: Image density is uneven, but at a good level. D: Image density is uneven, and the halftone image is not uniform.

[Evaluation of Fog]
A durability test was conducted in which a horizontal line image with a printing rate of 2% was printed on a total of 10,000 sheets with a 4-second intermittent time every two sheets under a low temperature and low humidity environment (15°C, 10% relative humidity; LL) and a high temperature and high humidity environment (30°C, 80% relative humidity; HH) (the printer was stopped for 5 seconds after each sheet was printed). Canon color laser copy paper (A4: 81.4 g/ ^m2 ) was used as the evaluation paper.

After the 1000-sheet durability test and the 10,000-sheet durability test, evaluation images were output the next morning. The evaluation images were LETTER-sized HP Color Laser Photo Paper, Glossy (manufactured by HP, 220 g/ ^m2 ) and solid white images were output. Note that the drum unit was replaced with a new one before the evaluation images were output.

For the evaluation, an amber filter was set in a "REFLECTO METER MODEL TC-6DS" (manufactured by Tokyo Denshoku Co., Ltd.) and the reflectance (%) of the non-image areas of the printout image was measured. The reflectance obtained was subtracted from the reflectance (%) of unused printout paper (standard paper) measured in the same manner, and the result was used for evaluation. The smaller the value, the more suppressed image fog is.

In the low temperature, low humidity environment, only the evaluation images printed after the durability test were evaluated, while in the high temperature, high humidity environment, both the evaluation images printed after the durability test and the following morning were evaluated according to the following criteria.

The evaluation criteria were as follows: C or higher was judged as good.
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.

[Evaluation of Low-Temperature Fixability]
The evaluation machine used was a Canon laser beam printer LBP9600C, whose fixing unit had been modified so that the fixing temperature could be adjusted.

Using this modified machine, the fixing temperature was changed in 5°C increments from 140°C in a normal temperature and humidity environment (25°C, 50% RH) at a process speed of 268 mm/sec.

As another condition, a solid image with a toner amount of 0.40 mg/cm ² was formed on the image receiving paper, and heating and pressing were performed without oil.

Printing was performed under the above conditions, the paper passing state was visually confirmed, and the minimum temperature of the fixing unit when the paper passed through without wrapping was checked, and the wrapping resistance (low-temperature fixing ability) during low-temperature fixing was verified based on the following criteria.

As the image receiving paper, GF-600 (weight: 60 g/m ² , sold by Canon Marketing Japan Inc.) was used.

(Evaluation Criteria)
A: 140°C or 145°C
B: 150° C.
C: 155°C
D: 160°C or higher

The evaluation results of Toner 1 are summarized in Table 3. As shown in Table 3, the toner of Example 1 obtained good results in all evaluations.

[Examples 2 to 16, Comparative Examples 1 to 9, and Reference Example 1]
The obtained toner particles 2 to 26 were designated as toners 2 to 26, and evaluations were carried out in the same manner as in Example 1, except that they were used in place of toner 1. The results for each of the Examples, Comparative Examples, and Reference Examples are shown in Table 3.

Claims (6)

In a toner having toner particles containing a binder resin and an organosilicon polymer,
the toner particles have doughnut-shaped protrusions of the organosilicon polymer,
The protrusion is
(i) formed from the organosilicon polymer,
(ii) when the outer diameter of the doughnut shape is R (nm), the R is 40 nm or more and 200 nm or less,
(iii) when the inner diameter of the doughnut shape is r (nm), R−r is 10 nm or more and 70 nm or less;
(iv) the height is 10 nm or more and 50 nm or less;
(v) there are an average of 50 to 1,000 particles per 1.8 μm square on the surface of the toner particle,
The toner has an average circularity of 0.970 or more and 1.000 or less. The toner according to claim 1, wherein the inner diameter of the protrusions is 30 nm or more and 130 nm or less. The toner according to claim 1 or 2, wherein the ratio (r/R) of the inner radius r to the outer radius R of the convexity is 0.20 or more and 0.60 or less. The toner according to any one of claims 1 to 3, wherein the coefficient of variation of the average value of the difference (R-r) between the outer diameter R and the inner diameter r of the protrusions is 0.20 or less. the organosilicon polymer has a structure in which silicon atoms and oxygen atoms are bonded alternately,
The organosilicon polymer has a T3 unit structure represented by RaSiO3 _/2 , where Ra represents an alkyl group or a phenyl group having 1 to 6 carbon atoms,
5. The toner according to claim 1, wherein in ^29Si -NMR measurement of said organosilicon polymer, the ratio of the area of the peak derived from silicon having the T3 unit structure to the total area of the peaks derived from all silicon elements contained in said organosilicon polymer is 0.65 or more and 0.80 or less. A method for producing the toner according to any one of claims 1 to 5,
A method for producing a toner, comprising: a step of condensing a compound of the following formula (1) in a slurry of toner base particles dispersed in an aqueous medium using magnesium hydroxide fine particles; and a step of dissolving and removing the magnesium hydroxide fine particles:

(In formula (1), R ₁ represents a hydrocarbon group having 1 to 6 carbon atoms, and R ₂ , R ₃ and R ₄ each independently represent a halogen atom, a hydroxyl group, an acetoxy group or an alkoxy group.)

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