JP6907049B2 - Black toner - Google Patents

Description

The present invention relates to black toner used in a recording method using an electrophotographic method or the like.

Many known electrograph methods are known. Generally, a photoconductive substance is used to form an electrostatic latent image on a electrostatic charge image carrier (hereinafter, also referred to as “photoreceptor”) by various means. Next, the latent image is developed with toner to obtain a visible image, and if necessary, the toner image is transferred to a recording medium such as paper, and then the toner image is fixed on the recording medium by heat or pressure to make a copy. To get. Examples of the image forming apparatus using such an electrophotographic method include a copier and a printer.
These printers and copiers are shifting from analog to digital, and are required to have excellent latent image reproducibility and high resolution, as well as stable image quality even after long-term use. Further, a toner having good fixability is required as an energy saving measure, and the melt viscosity of the binder resin is improved in order to improve the fixability.

However, even with toner having improved fixability, the performance of tape peeling resistance, which evaluates whether or not the toner is partially peeled off by the tape after printing, may be emphasized. This is especially likely to occur in areas where the amount of toner applied is small, such as line images, due to insufficient toner melting characteristics and insufficient releasability between the toner and the fixing member. Conceivable.
Further, in recent years, printers have been increasing in speed and life, and durability performance higher than that of conventional printers is required. Among them, deterioration of image quality due to stains on the fixing film after printing a large amount is also an issue. Many techniques have been disclosed for the above problems (see, for example, Patent Documents 1 to 3).

Japanese Unexamined Patent Publication No. 2008-9211 JP-A-2009-109824 Japanese Unexamined Patent Publication No. 2005-300937

However, even the toners of Patent Documents 1 to 3 are insufficient in terms of improving the tape peeling resistance, preventing the fixing film from becoming dirty, and establishing a high degree of durability, and improvement is required.
An object of the present invention is to provide a toner which is excellent in tape peeling resistance, maintains an excellent image density even when used for a long period of time, and is less likely to cause contamination of a fixing member.

The present invention is a black toner having toner particles containing a binder resin, a crystalline material and a black colorant.
The load at the bending point of the load displacement curve by the micro-compression measurement of the black toner is 1.0 mN or more and 3.0 mN or less.
The peak molecular weight of the tetrahydrofuran-soluble component of the black toner is 5000 or more and 40,000 or less.
The amount of tetrahydrofuran insoluble in the resin component of the black toner is 3% by mass or more and 50% by mass or less in the resin component of the black toner.
In the cross section of the toner particles observed by a transmission electron microscope,
When the major axis of the cross section of the toner particles is R (μm) and the major axis of the domain of the crystalline material is r (μm),
Regarding the toner particle cross section in which R (μm) satisfies 4 ≦ R ≦ 12, the domain of the crystalline material satisfying the following formula (i) is defined as domain A, and the number of the domains A per one toner particle cross section is determined. The present invention relates to black toner characterized by having 50 or more and 300 or less.
(I) 5.0 × 10 ^-4 ≦ r / R ≦ 7.0 × 10 ^-2

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a toner which is excellent in tape peeling resistance, maintains excellent image density even when used for a long period of time, and is less likely to cause contamination of fixing members.

Schematic cross-sectional view showing an example of an image forming apparatus Graph showing an example of load displacement curve in microcompression test

In the present invention, the description of "○○ or more and XX or less" and "○○ to XX" indicating a numerical range means a numerical range including a lower limit and an upper limit which are end points, unless otherwise specified. The present inventors have found that the melt characteristics and toner hardness can be highly controlled by adopting the following configuration, and the tape peeling resistance, the fixing member contamination, and the durability can be significantly improved. In particular,
A black toner having toner particles containing a binder resin, a crystalline material, and a black colorant.
The load at the bending point of the load displacement curve by the micro-compression measurement of the black toner is 1.0 mN or more and 3.0 mN or less.
The peak molecular weight of the tetrahydrofuran-soluble component of the black toner is 5000 or more and 40,000 or less.
The amount of tetrahydrofuran insoluble in the resin component of the black toner is 50% by mass or less of the resin component of the black toner.
In the cross section of the toner particles observed by a transmission electron microscope,
When the major axis of the cross section of the toner particles is R (μm) and the major axis of the domain of the crystalline material is r (μm),
Regarding the toner particle cross section in which R (μm) satisfies 4 ≦ R ≦ 12, the domain of the crystalline material satisfying the following formula (i) is defined as domain A, and the number of the domains A per one toner particle cross section is determined. It is a black toner characterized by having 20 or more and 300 or less.
(I) 5.0 × 10 ^-4 ≦ r / R ≦ 7.0 × 10 ^-2

According to the study by the present inventors, with the above configuration, the domain A melts to plasticize the entire resin at the time of heat fixing, and the crystalline material constituting the domain A exudes to the surface of the toner particles. It improves the fixability and exhibits the releasability from the fixing member such as the fixing film. At this time, if the hardness satisfies the above-mentioned specific range by the microcompression measurement, the melt deformation is minimized even at the time of heat fixing, so that the adhesive force to the fixing member can also be reduced. The exudation of these crystalline materials and the high toner hardness work synergistically to greatly improve the contamination of the fixing member.
Further, the toner hardness has a great effect on durability, and the fine dispersion of the crystalline material has a great effect on tape peeling resistance. Above all, regarding the tape peeling resistance, it is important that the material having the mold release performance quickly exudes to the surface of the toner particles, and it is important to highly control the dispersed state of the crystalline material.

The requirements for microcompression measurement in the present invention will be further described. The black toner of the present invention has a load at a bending point of 1.0 mN or more and 3.0 mN or less when measured by minute compression. This is a range that can be satisfied by hardening the toner resin itself in the prior art, for example, by increasing the molecular weight to tens of thousands or increasing the amount of THF insoluble. However, if these methods are relied on, the fixability is significantly reduced, and it is difficult to apply them to systems with high speeds in recent years.
According to the studies by the present inventors, it was important to keep the molecular weight and the THF insoluble content within a certain range in order to ensure the fixability. Among them, it was found that both fixability and hardness can be achieved by increasing the hardness of the toner and combining the finely dispersed structure of the crystalline material. The load is preferably 1.2 mN or more and 3.0 mN or less.
Further, when the load is within the above range, not only the tape peeling resistance but also the fixing film stain is remarkably improved because the wetting spread at the time of fixing and the seepage of the crystalline material inside the toner are not hindered.
Here, when there is no bending point, that is, when it is very hard, the deformation at the time of fixing becomes slow, and the object of the present invention cannot be achieved.

There are various methods for achieving the above hardness, and the outline of the preferable method will be described. For example, it is preferable that the toner particles have a surface layer containing an organosilicon condensate. Although such a surface layer is extremely resistant to deformation, if the bottom of the surface layer is soft, it is difficult for the bending point to reach 1.0 mN or more. Therefore, it is preferable to use the organosilicon condensate as the surface layer and then disperse the magnetic material in the vicinity of the surface layer. As a result, when the load applied to the toner surface is received by the surface layer and the toner is slightly deformed, the internal magnetic material dispersion region can receive the deformation, so that the load at the bending point can be significantly increased. ..
Further, according to the diligent studies by the present inventors, it is preferable that the organosilicon condensate has a network structure. With the network structure, the load can be dispersed, and it is difficult to prevent the crystalline material from seeping out to the surface of the toner particles.

Further, in the micro-compression measurement, the black toner of the present invention is a ratio of the displacement of toner particles at a load 1.0 mN larger than the load at the bending point to the average diameter D1 of the number of toners (hereinafter, the ratio of displacement of toner particles). (Also referred to as) is preferably 20% or more and 60% or less. More preferably, it is 30% or more and 55% or less. When a load 1.0 mN larger than the load at the bending point is applied, the hardness can be evaluated not only from the surface layer portion of the toner particles but also to a depth of about 1 μm from the surface layer of the toner particles. Here, if it is within the above range, the durability can be further improved while the fixation inhibition is small. The ratio can be controlled by the molecular weight of the binder resin, the wax formulation, and the amount of THF insoluble.

In the present invention, in the cross section of the toner particles observed by a transmission electron microscope, when the major axis of the toner particle cross section is R (μm) and the major axis of the domain of the crystalline material is r (μm),
Regarding the toner particle cross section in which the major axis R satisfies 4 ≦ R ≦ 12, when the domain of the crystalline material satisfying the following formula (i) is domain A, the number of domains A per one toner particle cross section is 20. It is important that the number is 300 or less.
(I) 5.0 × 10 ^-4 ≦ r / R ≦ 7.0 × 10 ^-2
It has been found by the present inventors that the durability of the toner is significantly improved and the tape peeling resistance is also improved when the number of domains A and the load range of the bending point described above are satisfied. It is presumed that this is because the micro-domain composed of the crystalline material acts as a filler and improves the strength of the binding resin portion of the toner, so that the strength of the entire toner is greatly improved in combination with the hardness of the surface layer. .. Further, since the finely dispersed domain of the crystalline material is excellent in the plasticizing ability of the binder resin and the exuding property to the surface at the time of fixing, not only the durability but also the tape peeling resistance and the fixing film stain are greatly improved.

The number of domains A per cross section of one toner particle is preferably 50 or more and 300 or less. The number of domains A can be controlled by selecting a crystalline material, adding an amount, and adding a step of heating the toner to a temperature equal to or higher than the melting point of the crystalline material and then cooling the toner, and adjusting the step conditions. The same applies to the major axis of the domain A, which can be controlled by selecting a crystalline material, adding an amount, and adding a step of heating the toner to a temperature equal to or higher than the melting point of the crystalline material and then cooling the toner, and adjusting the step conditions. Specifically, it is preferable to include a step of holding the toner at a temperature at which crystallization of the crystalline material is promoted in a cooling step after heating during toner production.

In the present invention, it is necessary that the peak molecular weight of the tetrahydrofuran (THF) soluble component contained in the toner is 5000 or more and 40,000 or less.
If the molecular weight is less than 5000, the brittleness of the binder resin is lowered, which causes adverse effects such as cracking of the toner during long-term use. Therefore, even if the surface layer is hardened, sufficient durable developability cannot be obtained. On the other hand, if it exceeds 40,000, the melting characteristics of the binder resin are significantly deteriorated, so that the wet spread on the paper is insufficient and the tape peeling resistance is significantly lowered.
The peak molecular weight of the tetrahydrofuran-soluble component is more preferably 8,000 or more and 35,000 or less, and further preferably 8,000 or more and 30,000 or less. For example, in the case of suspension polymerization toner, the peak molecular weight can be controlled by the amount and type of the polymerization initiator and the polymerization conditions. However, when the molecular weight is less than 5000, for example, in the case of a suspension polymerization toner, the oligomers are significantly increased, and the storage stability and chargeability are deteriorated, which is not preferable.

Further, it is necessary that the amount of the resin component contained in the toner insoluble in tetrahydrofuran is 50% by mass or less of the resin component of the toner.
The tetrahydrofuran insoluble content indicates the amount of the resin component having a crosslinked structure. Therefore, it is known that if the amount is increased, the fixing property is lowered, while the durability is improved. In the examination by the present inventors, it was found that when the insoluble content of 50% or less was contained, the durability was dramatically improved, but the inhibition on the fixability was small. On the other hand, if it exceeds 50%, the tape peeling resistance is remarkably lowered.
The proportion of tetrahydrofuran insoluble is preferably 3% by mass or more and 45% by mass or less. The ratio of the insoluble amount of tetrahydrofuran can be controlled by the amount of the cross-linking agent added, the type of the polymerization initiator and the polymerization conditions of the polymerized toner.

The crystalline material contained in the toner preferably contains an ester wax, and the melting point of the ester wax is preferably 65.0 ° C. or higher and 85.0 ° C. or lower. More preferably, it is 66 ° C. or higher and 84 ° C. or lower. The ester wax is easy to control the dispersed state, and when the melting point is in the above range, the fixability is easily improved while the influence on the storage stability and durability is small.

Further, when the major axis of the toner particle cross section is R (μm) and the major axis of the domain of the crystalline material is r (μm), the crystalline material forms a domain B satisfying the following formula (ii), and the toner particle cross section is formed. It is preferable that the ratio of the toner particles in which the domain B is present in the center of gravity of the toner particles is 80% by number or more. More preferably, it is 81% by number or more. The upper limit is not particularly limited, but is preferably 100% or less.
(Ii) 0.10 ≤ r / R ≤ 0.40
This means that there is a relatively large domain B in addition to a small domain such as domain A. The presence of domain B tends to accelerate the process by which domain A melts during fixation and exudes to the surface of the toner particles. Further, since the domain B functions as the core of the toner particles, the durability tends to be increased, which is preferable.
The proportion of toner particles in which domain B is present in the center of gravity of the toner particle cross section can be controlled by the toner production conditions, the selection of the crystalline material, and the addition amount. Similarly, the major axis of the domain B can be controlled by the toner production conditions, the selection of the crystalline material, and the addition amount.
As a method for forming both domains A and B, for example, a step of selecting a crystalline material having a high affinity for the binder resin and raising the temperature of the crystalline material to a temperature higher than the melting point at the time of production. And put in the cooling process. Further, by holding the material at a temperature that promotes crystal growth of the crystalline material, a toner containing both A and B can be obtained.
Further, the domains A and B are preferably derived from the same crystalline material.

The content of the ester wax in the toner is preferably 3.0 parts by mass or more and 25.0 parts by mass or less, and 5.0 parts by mass or more and 25.0 parts by mass or less with respect to 100 parts by mass of the binder resin. Is more preferable. Within this range, the dispersed state of the ester wax can be easily controlled, and the effect on storage stability and durability is small.
Further, the ester wax is preferably a polyfunctional ester wax having two or more ester bonds in the structure. Since the ester-bonded portion allows bending in the molecule, a folded structure can be formed when the ester-bonded portion has two or more ester bonds, and it becomes easy to form a crystal having a high crystallinity.

The toner preferably contains a magnetic substance as a black colorant. Further, in the cross section of the toner particles observed by a transmission electron microscope, the abundance ratio of the magnetic substance in the region within 10% of the distance between the contour and the center of gravity of the cross section from the contour of the toner particle cross section (hereinafter, 10%). The magnetic material ratio) is preferably 70 area% or more and 100 area% or less of the total area occupied by the magnetic material. More preferably, it is 70 area% or more and 90 area% or less.
The presence of the magnetic material is also preferable because if it is biased toward the surface layer of the toner particles and there is a shell made of organosilicon described above, the strength of the toner is synergistically increased. For example, in the case of a toner produced in an aqueous medium, the abundance ratio of the magnetic material can be controlled by the state of the hydrophobic treatment of the magnetic material used, the amount of the magnetic material added, and the dispersion conditions in the step of dispersing the magnetic material. ..

Hereinafter, preferred embodiments of the black toner of the present invention will be described.
First, the crystalline material will be described. The crystalline material is not particularly limited, and a known material can be used, but a mold release agent such as an ester wax and a hydrocarbon wax is preferable. A crystalline material is a material that exhibits a clear melting point in measurement using a differential scanning calorimeter (DSC).
The melting point of the release agent is preferably 50 ° C. or higher and 90 ° C. or lower.

Hereinafter, the release agent will be described.
Examples of the release agent include the following. Fatty hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystallin wax, fishertropic wax, paraffin wax; oxides of fatty hydrocarbon waxes such as polyethylene oxide wax, or block copolymers thereof. Waxes mainly composed of fatty acid esters such as carnauba wax and montanic acid ester wax, and deoxidized fatty acid esters such as carnauba wax partially or completely deoxidized; palmitic acid, stearic acid, montanic acid, etc. Saturated linear fatty acids; unsaturated fatty acids such as braszic acid, eleostearic acid, parinaric acid; saturated alcohols such as stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvyl alcohol, ceryl alcohol, melicyl alcohol; sorbitol Polyhydric alcohols such as; fatty acid amides such as linoleic acid amide, oleic acid amide, lauric acid amide; methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, hexamethylene bisstearic acid amide, etc. Saturated fatty acid bisamides; unsaturated fatty acid amides such as ethylene bisoleic acid amide, hexamethylene bisoleic acid amide, N, N'diorail adipic acid amide, N, N'diorail sebacic acid amide; m-xylene bisstearic acid Aromatic bisamides such as acid amide, N, N'dystearyl isophthalic acid amide; fatty acid metal salts such as calcium stearate, calcium laurate, zinc stearate, magnesium stearate (generally referred to as metal soap); Waxes obtained by grafting aliphatic hydrocarbon wax with vinyl monomer such as styrene or acrylic acid; partial esterified product of fatty acid such as behenic acid monoglyceride and polyhydric alcohol; obtained by hydrogenation of vegetable fats and oils Examples thereof include methyl ester compounds having a hydroxyl group.

In the present invention, it is preferable to use a hydrocarbon wax and a wax containing a fatty acid ester as a main component (hereinafter, ester wax) because it is easy to have both fixability and releasability from the fixing film. Further, it is also a preferable form to use the ester wax and the hydrocarbon wax together.
The preferred ester wax will be described below. The functional number described below indicates the number of ester groups contained in one molecule. For example, behenic behenate is called a monofunctional ester wax, and dipentaerythritol hexabehenate is called a hexafunctional ester wax.
As the monofunctional ester wax, a condensate of an aliphatic alcohol and an aliphatic carboxylic acid is preferable. At this time, the aliphatic carbon number is preferably 6 to 26 carbon atoms.
Examples of fatty alcohols include 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol, 1-decanol, undecyl alcohol and lauryl alcohol. Examples of aliphatic carboxylic acids include pelargonic acid, caproic acid, heptanic acid, octanoic acid, nonanoic acid, and decanoic acid.

As the bifunctional ester wax, a combination of a dicarboxylic acid and a monoalcohol and a diol and a monocarboxylic acid can be used.
Examples of the dicarboxylic acid include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedic acid.
Examples of the diol include 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-. Dodecanediol can be mentioned.
As the monoalcohol to be condensed with the dicarboxylic acid, an aliphatic alcohol is preferable. Specific examples thereof include tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol, docosanol, tricosanol, tetracosanol, pentacosanol, hexacosanol, octacosanol and the like. .. Above all, docosanol is preferable from the viewpoint of fixability and developability.
As the monocarboxylic acid to be condensed with the diol, an aliphatic carboxylic acid is preferable. Specific examples of the fatty acid include lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, tuberculostearic acid, arachidic acid, behenic acid, lignoceric acid, and cerotic acid. Of these, behenic acid is preferable from the viewpoint of fixability and developability.
Although linear fatty acids and linear alcohols have been exemplified here, they may have a branched structure.

A trifunctional or higher functional ester wax can also be used. Here, an example of obtaining a trifunctional or higher functional ester wax will be given.
Examples of the trifunctional SL wax include a condensate of a glycerin compound and a monofunctional aliphatic carboxylic acid. Examples of the tetrafunctional ester wax include a condensate of pentaerythritol and a monofunctional aliphatic carboxylic acid, and a condensate of diglycerin and a carboxylic acid. Examples of the pentafunctional ester wax include a condensate of triglycerin and a monofunctional aliphatic carboxylic acid. Examples of the hexafunctional ester wax include a condensate of dipentaerythritol and a monofunctional aliphatic carboxylic acid, and a condensate of tetraglycerin and a monofunctional aliphatic carboxylic acid.
As the ester wax, bifunctional to hexafunctional ones are preferable from the viewpoint of domain formation.

The binder resin used for the toner is a homopolymer of styrene such as polystyrene and polyvinyltoluene and its substitution product; styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalin copolymer, styrene. -Methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, octyl styrene-octyl acrylate copolymer, dimethylaminoethyl styrene-acrylate copolymer, styrene-methacryl Methyl acid acid copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylic acid copolymer, styrene-dimethylaminoethyl methacrylate copolymer, styrene-vinylmethyl ether copolymer, styrene-vinyl ethyl Styrene-based copolymers such as ether copolymer, styrene-vinylmethylketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer, etc. Combined; Polymethylmethacrylate, Polybutylmethacrylate, Polyvinylacetate, Styrene, Polypropylene, Polyvinylbutyral, Silicone resin, Polyester resin, Polyethylene resin, Epoxy resin, Polyacrylic acid resin can be used, and these may be used alone or in combination of two or more. Can be used in combination. Of these, a styrene-based copolymer typified by styrene-butyl acrylate is particularly preferable in terms of development characteristics, fixability, and the like.

Examples of the polymerizable monomer forming the styrene-based copolymer include the following.
Examples of the styrene-based polymerizable monomer include styrene; styrene-based polymerizable monomers such as α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, and p-methoxystyrene.
Examples of the acrylic polymerizable monomer include methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, n-hexyl acrylate, and 2-ethylhexyl acrylate. , N-octyl acrylate, cyclohexyl acrylate and other acrylic polymerizable monomers.
Examples of the methacrylic polymerizable monomer include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert-butyl methacrylate, n-hexyl methacrylate, and 2-ethylhexyl methacrylate. , N-Methyl methacrylate-based polymerizable monomers such as octyl methacrylate.

As for the binder resin, it is preferable that the main component is a styrene-based polymerizable monomer and a styrene-acrylic resin formed from an acrylic-based polymerizable monomer and / or a methacrylic-based polymerizable monomer. This makes it easy to stably create a domain of a crystalline material on the order of several μm. Here, the main component refers to a component whose content is 70% by mass or more. From the viewpoint of image stability, 80% by mass or more is preferable.
The method for producing the styrene-based copolymer is not particularly limited, and a known method can be used. The content of the styrene-based copolymer with respect to the total amount of the binder resin is preferably 70% by mass or more, and more preferably 80% by mass or more. Further, the binder resin may be used in combination with other known resins.

Examples of the black colorant used in the present invention include carbon black and magnetic powder. In addition, a yellow colorant, a magenta colorant, and a cyan colorant may be used to adjust the color to black.
These black colorants can be used alone or in the form of a solid solution. The colorant is selected in terms of hue angle, saturation, lightness, light resistance, OHP transparency, and dispersibility in toner particles.
Among the above, a magnetic material is preferable.

The magnetic material is mainly composed of magnetic iron oxide such as triiron tetraoxide and γ-iron oxide, and may contain elements such as phosphorus, cobalt, nickel, copper, magnesium, manganese, aluminum and silicon. These magnetic materials preferably have a BET specific surface area of ² to 30 m 2 / g by the nitrogen adsorption method, and more preferably 3 to 28 m ² / g. Further, those having a Mohs hardness of 5 to 7 are preferable. The shape of the magnetic powder includes a polyhedron, an octahedron, a hexahedron, a sphere, a needle, and a scale, but a polyhedron, an octahedron, a hexahedron, a sphere, and the like having less anisotropy have an image density. It is preferable to enhance it.

The magnetic material preferably has a number average particle size of 0.10 to 0.40 μm. This range is preferable from the viewpoint of the balance between coloring power and cohesiveness.
The number average particle diameter of the magnetic material can be measured using a transmission electron microscope. Specifically, after the toner particles to be observed are sufficiently dispersed in the epoxy resin, the cured product is obtained by curing in an atmosphere at a temperature of 40 ° C. for 2 days. A flaky sample was obtained from the obtained cured product by a microtome and observed with a transmission electron microscope (TEM) at a magnification of 10,000 to 40,000 times. To measure. The number average particle size is calculated based on the equivalent diameter of a circle equal to the projected area of the magnetic material. It is also possible to measure the particle size with an image analyzer.

The magnetic material can be produced, for example, by the following method. An aqueous solution containing ferrous hydroxide is prepared by adding an alkali such as sodium hydroxide to the ferrous salt aqueous solution in an equivalent amount or an equivalent amount or more with respect to the iron component. Air is blown while maintaining the pH of the prepared aqueous solution at pH 7 or higher, and the ferrous hydroxide oxidation reaction is carried out while heating the aqueous solution to 70 ° C. or higher to first form seed crystals that are the core of the magnetic iron oxide powder. Generate.
Next, an aqueous solution containing about 1 equivalent of ferrous sulfate is added to the slurry-like liquid containing seed crystals based on the amount of alkali added previously. While maintaining the pH of the liquid at 5 to 10, the reaction of ferrous hydroxide is promoted while blowing air, and magnetic iron oxide is grown around the seed crystal. At this time, the shape and magnetic properties of the magnetic powder can be controlled by selecting an arbitrary pH, reaction temperature, and stirring conditions. As the oxidation reaction progresses, the pH of the liquid shifts to the acidic side, but it is preferable that the pH of the liquid is not less than 5. The magnetic material thus obtained can be obtained by filtering, washing and drying the magnetic material by a conventional method.

Further, when the toner is produced in an aqueous medium, it is preferable to hydrophobize the surface of the magnetic material. When surface treatment is performed by a dry method, a coupling agent treatment is performed on the washed, filtered, and dried magnetic material. When the surface treatment is performed wet, the dried product is redispersed after the oxidation reaction is completed, or the oxide obtained by washing and filtering after the oxidation reaction is completed is placed in another aqueous medium without drying. Redisperse and perform coupling processing. In the present invention, both the dry method and the wet method can be appropriately selected.

Examples of the coupling agent that can be used in the surface treatment of the magnetic material include a silane coupling agent and a titanium coupling agent. More preferably used is a silane coupling agent, which is represented by the general formula (I).
R _m SiY _n (I)
[In the formula, R represents an alkoxy group, m represents an integer of 1 to 3, Y represents a functional group such as an alkyl group, a vinyl group, an epoxy group, an acrylic group, and a methacryl group, and n represents 1-3. Indicates an integer. However, m + n = 4. ]
In the present invention, it is preferable that Y in the general formula (I) is an alkyl group. Of these, an alkyl group having 3 or more and 6 or less carbon atoms is preferable, and 3 or 4 is more preferable.

When the above silane coupling agent is used, it can be treated alone or in combination of a plurality of types. When a plurality of types are used in combination, they may be treated individually with each coupling agent or may be treated at the same time.
The total amount of the coupling agent to be treated is preferably 0.9 to 3.0 parts by mass with respect to 100 parts by mass of the magnetic material, and is treated according to the surface area of the magnetic powder, the reactivity of the coupling agent, and the like. It is preferable to adjust the amount of the agent.

Other colorants may be used in combination with the magnetic material. Examples of the colorant that can be used in combination include known dyes and pigments, as well as magnetic or non-magnetic inorganic compounds. Specifically, ferromagnetic metal particles such as cobalt and nickel, or alloys obtained by adding chromium, manganese, copper, zinc, aluminum, rare earth elements, etc. to these. Particles such as hematite, titanium black, niglosin dye / pigment, carbon black, phthalocyanine and the like can be mentioned. These are also preferably surface-treated and used.
The content of the colorant is preferably 0.1 part by mass or more and 30.0 parts by mass or less with respect to 100 parts by mass of the binder resin.
When a magnetic material is used, the content of the magnetic material in the toner is preferably 65 parts by mass or more and 90 parts by mass or less with respect to 100 parts by mass of the binder resin.
The content of the magnetic substance in the toner can be measured by using a thermal analyzer TGA7 manufactured by PerkinElmer. The measurement method is as follows. The toner is heated from room temperature to 900 ° C. at a heating rate of 25 ° C./min in a nitrogen atmosphere. The weight loss mass% between 100 ° C. and 750 ° C. is defined as the amount of binder resin, and the residual mass is approximately defined as the amount of magnetic material.

If necessary, a charge control agent can be used as the toner. As the charge control agent, known ones can be used, but a charge control agent having a high triboelectric rate and capable of stably maintaining a constant triboelectric charge amount is preferable. Further, when the toner particles are produced by the suspension polymerization method, a charge control agent having low polymerization inhibitory property and substantially no solubilized product in an aqueous medium is preferable.
There are two types of charge control agents, one that controls the toner to be load-electric and the other that controls the toner to be positively charged. Examples of those that control the toner to load electrical properties include the following. Monoazo metal compounds; acetylacetone metal compounds; aromatic oxycarboxylic acids; aromatic dicarboxylic acids; oxycarboxylic acids or dicarboxylic acid-based metal compounds; aromatic oxycarboxylic acids; aromatic mono or polycarboxylic acids and their metal salts, Anhydrides and esters; phenol derivatives such as bisphenol; urea derivatives; metal-containing salicylic acid-based compounds; metal-containing naphthoic acid-based compounds; boron compounds; quaternary ammonium salts; calix array; and charge control resins. ..
Examples of the charge control agent that controls the toner to be positively charged include the following. Guanidin compounds; imidazole compounds; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and onium salts such as phosphonium salts which are analogs thereof. , And these lake pigments; triphenylmethane dyes and their lake pigments (as lake agents, phosphotung acid, phosphomolybdic acid, phosphotungene molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, and , Ferocyanide); Metal salts of higher fatty acids; Charge control resins.
The above charge control agents can be used alone or in combination of two or more.
Among these charge control agents, metal-containing salicylic acid-based compounds are preferable, and those whose metal is aluminum or zirconium are particularly preferable.
The amount of the charge control agent added is preferably 0.01 parts by mass or more and 20.0 parts by mass or less, more preferably 0.5 parts by mass or more and 10.0 parts by mass with respect to 100.0 parts by mass of the binder resin. It is less than a part.

Further, as the charge control resin, it is preferable to use a polymer or copolymer having a sulfonic acid group, a sulfonic acid base or a sulfonic acid ester group. As the polymer having a sulfonic acid group, a sulfonic acid base or a sulfonic acid ester group, it is particularly preferable to contain 2% by mass or more of a sulfonic acid group-containing acrylamide-based monomer or a sulfonic acid group-containing methacrylic acid-based monomer in a copolymerization ratio. .. More preferably, it is contained in an copolymerization ratio of 5% by mass or more.
The charge control resin has a glass transition temperature (Tg) of 35 ° C. or higher and 90 ° C. or lower, a peak molecular weight (Mp) of 10,000 or higher and 30,000 or lower, and a weight average molecular weight (Mn) of 25,000 or higher and 50,000 or lower. Some are preferred. When this charge control resin is used, preferable triboelectric charge characteristics can be imparted without affecting the thermal characteristics required for the toner particles. Further, since the charge control resin contains a sulfonic acid group or the like, the dispersibility of the charge control resin itself in the dispersion liquid of the colorant and the dispersibility of the colorant are improved, and the coloring power, transparency, and transparency are improved. The triboelectric charge characteristics can be further improved.

The weight average particle size (D4) of the toner is preferably 3.0 μm or more and 12.0 μm or less, and more preferably 4.0 μm or more and 10.0 μm or less. Within the above range, good fluidity can be obtained and the latent image can be developed faithfully.

Toner particles can be produced by any known method. When manufactured by the pulverization method, for example, a binder resin, a black colorant, a crystalline material, and if necessary, a low melting point substance and other additives such as a charge control agent are mixed in a mixer such as a Henschel mixer or a ball mill. Mix well. After that, the toner material is dispersed or melted by melt-kneading using a heat kneader such as a heating roll, a kneader, or an extruder, cooled and solidified, crushed, classified, and surface-treated if necessary to obtain toner particles. Obtainable. Either of the order of classification and surface treatment may come first. In the classification process, it is preferable to use a multi-division classifier in terms of production efficiency.

The crushing step can be performed by a method using a known crushing device such as a mechanical impact type or a jet type. Further, it is preferable to further apply heat to pulverize the mixture, or to perform a process of applying an auxiliary mechanical impact. Further, a hot water bath method in which finely pulverized (classified if necessary) toner particles are dispersed in hot water, a method in which the toner particles are passed through a hot air stream, or the like may be used.
As a means for applying the mechanical impact force, for example, a method using a mechanical impact type crusher such as a cryptron system manufactured by Kawasaki Heavy Industries, Ltd. or a turbo mill manufactured by Turbo Industries, Ltd. can be mentioned. In addition, like devices such as the mechanofusion system manufactured by Hosokawa Micron and the hybridization system manufactured by Nara Kikai Seisakusho, toner particles are pressed against the inside of the casing by centrifugal force with blades that rotate at high speed, and forces such as compressive force and frictional force There is a method of applying a mechanical impact force to the toner particles.

Toner particles can also be produced by an emulsion aggregation method, a suspension polymerization method, or the like. It is preferable to produce toner particles in an aqueous medium in order to control the existence state of the crystalline material. The suspension polymerization method is preferable because it is easy to control the dispersion state of the crystalline polyester and form a domain on the order of several μm.

The suspension polymerization method will be described below.
The suspension polymerization method uses a polymerizable monomer, a crystalline material, and a black colorant (and, if necessary, a polymerization initiator, a cross-linking agent, a charge control agent, and other additives) that can form a binder resin. Uniformly dissolved or dispersed to obtain a polymerizable monomer composition. Then, this polymerizable monomer composition is dispersed and granulated in a continuous layer (for example, an aqueous phase) containing a dispersant using an appropriate stirrer, and is contained in the polymerizable monomer composition. A polymerization reaction of a polymerizable monomer is carried out to obtain toner particles having a desired particle size. Since the toners obtained by this suspension polymerization method (hereinafter, also referred to as "polymerized toners") have almost spherical shapes of individual toner particles, the distribution of the amount of charge is relatively uniform, so that the image quality is improved. You can expect it.

Examples of the polymerizable monomer include the above-mentioned styrene-based polymerizable monomer, acrylic-based polymerizable monomer, and methacrylic-based polymerizable monomer.
In addition, monomers such as acrylonitrile, methacrylonitrile, and acrylamide can be mentioned. These monomers may be used alone or in admixture.

The polymerization initiator used in the production of toner particles by the polymerization method preferably has a half-life of 0.5 to 30 hours during the polymerization reaction. Further, when the polymerization reaction is carried out with an addition amount of 0.5 to 20 parts by mass with respect to 100 parts by mass of the polymerizable monomer, a polymer having a maximum molecular weight between 5,000 and 50,000 can be obtained. It can give the toner the desired strength and suitable melting properties.
Specific examples of polymerization initiators include 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, and 1,1'-azobis (cyclohexane-1-). Carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile and other azo or diazo polymerization initiators; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropylper Peroxide-based polymerization initiators such as oxycarbonate, cumenehydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, t-butylperoxy2-ethylhexanoate, and t-butylperoxypivalate Can be mentioned.

When the toner particles are produced by the polymerization method, a cross-linking agent may be added. The preferable amount to be added is 0.001 to 15 parts by mass with respect to 100 parts by mass of the polymerizable monomer.
Here, as the cross-linking agent, a compound having two or more polymerizable double bonds is mainly used, and for example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; for example, ethylene glycol diacrylate and ethylene glycol di. A carboxylic acid ester having two double bonds such as methacrylate, 1,3-butanediol dimethacrylate; a divinyl compound such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone; and having three or more vinyl groups. Compound; is used alone or as a mixture of two or more.

In the method of producing toner particles by a polymerization method, for example, a polymerizable monomer composition uniformly dissolved or dispersed by a disperser such as a homogenizer, a ball mill, or an ultrasonic disperser is contained in an aqueous medium containing a dispersant. Suspend in. At this time, if a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser is used to make the desired toner particle size at once, the particle size of the obtained toner particles becomes sharper. The polymerization initiator may be added at the same time as the other additives are added to the polymerizable monomer, or may be mixed immediately before suspension in the aqueous medium. It is also possible to add a polymerizable monomer or a polymerization initiator dissolved in a solvent immediately after granulation and before starting the polymerization reaction.
After granulation, a normal stirrer may be used to stir the particles to the extent that the state of the particles is maintained and the floating and sedimentation of the particles are prevented.

A surfactant, an organic dispersant, or an inorganic dispersant known as a dispersant can be used for producing the toner particles. Among them, the inorganic dispersant is less likely to generate harmful ultrafine powder and has obtained dispersion stability due to its steric hindrance, so that the stability is less likely to be lost even if the reaction temperature is changed, cleaning is easy, and the toner is less likely to be adversely affected. Therefore, it is preferable.
Examples of inorganic dispersants include tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, hydroxyapatite and other phosphate polyvalent metal salts, calcium carbonate, magnesium carbonate and other carbonates, calcium metasilicate, calcium sulfate, and sulfuric acid. Examples thereof include inorganic salts such as barium and inorganic compounds such as calcium hydroxide, magnesium hydroxide and aluminum hydroxide.
It is preferable to use 0.2 to 20 parts by mass of these inorganic dispersants with respect to 100 parts by mass of the polymerizable monomer. Further, the above-mentioned dispersant may be used alone or in combination of two or more.

When these inorganic dispersants are used, they may be used as they are, but in order to obtain finer particles, the inorganic dispersant particles can be generated and used in an aqueous medium. For example, in the case of tricalcium phosphate, a water-insoluble calcium phosphate can be produced by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring, and more uniform and fine dispersion becomes possible. At this time, a water-soluble sodium chloride salt is produced as a by-product at the same time, but if the water-soluble salt is present in the aqueous medium, the dissolution of the polymerizable monomer in water is suppressed and ultrafine toner is generated by emulsion polymerization. It is more convenient because it becomes difficult to do.
Further, 0.001 to 0.1 parts by mass of a surfactant may be used in combination with 100 parts by mass of the polymerizable monomer. Examples of the surfactant include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate and the like.

In the step of polymerizing the above-mentioned polymerizable monomer, the polymerization temperature is usually set to 40 ° C. or higher, preferably 50 to 90 ° C. When polymerization is carried out in this temperature range, crystalline materials such as ester wax to be sealed inside are easily precipitated by phase separation and encapsulated.
After the polymerization of the polymerizable monomer is completed to obtain toner particles, it is preferable to raise the temperature to a temperature exceeding the melting point of the crystalline material in a state where the toner particles are dispersed in an aqueous medium. If the polymerization temperature exceeds the above-mentioned melting point, this operation is not necessary.

Further, when the toner particles are formed with a surface layer containing an organosilicon condensate, for example, the following method can be mentioned.
The organosilicon compound is hydrolyzed in an aqueous medium, and the aqueous medium having the compound obtained by hydrolyzing the organosilicon compound is added to the aqueous medium in which the toner particles are dispersed. The timing of addition may be immediately after the granulation step (that is, before the polymerization step), during the polymerization step, or after the completion of the polymerization step.
Further, it may be divided and added at a plurality of timings.

In addition, there are the following manufacturing methods. That is,
A method for producing a toner having toner particles having a surface layer containing an organosilicon condensate, wherein the toner particles contain a binder resin, a crystalline material, and a black colorant.
A method for producing a toner, which comprises the following steps (A) and (B).
(A) A step of hydrolyzing at least one organosilicon compound selected from the group consisting of the compounds represented by the formulas (1) to (4) to obtain a compound obtained by hydrolyzing the organosilicon compound (B). A compound obtained by hydrolyzing an organosilicon compound and an aqueous medium containing toner particles are mixed, and the compound hydrolyzed by the organosilicon compound is condensed to form a surface layer containing an organosilicon condensate on the surface of the toner particles. Step of making the toner particles can be produced by a suspension polymerization method, a dissolution suspension method, an emulsion aggregation method, a pulverization method, or the like. When the toner particles are produced in an aqueous medium, they may be used as they are in the next step, or may be redispersed in the aqueous medium after being washed, filtered, and dried. When the toner particles are produced by a dry method, they can be dispersed in an aqueous medium by a known method. In order to disperse the toner particles in the aqueous medium, it is preferable that the aqueous medium contains a dispersion stabilizer.
As the organosilicon compound, at least one selected from the group consisting of the compounds represented by the following formulas (1) to (4) can be used.

(In the above formula, R ^a , R ^b , R ^c , R ^d , ^Re , and R ^f are partially substituted with an amino group or a halogen atom, or unsubstituted (preferably having 1 to 6 carbon atoms). Alkyl group (preferably 1 to 6 carbon atoms), acyl group (preferably 1 to 6 carbon atoms) or aryl group (preferably 6 to 14 carbon atoms), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , and R ¹⁰ are alkoxy groups (preferably having 1 to 4 carbon atoms).
For example, the following silane compounds can be mentioned.

A tetrafunctional silane compound such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, or tetrabutoxysilane. The tetrafunctional silane compound means a silane compound having four alkoxy groups.
A trifunctional methylsilane of methyltrimethoxysilane, methyltriethoxysilane, methyldiethoxymethoxysilane, and methylethoxydimethoxysilane.
Trifunctional silane compounds such as ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, hexyltrimethoxysilane, and hexyltriethoxysilane.
Trifunctional phenylsilane such as phenyltrimethoxysilane and phenyltriethoxysilane.
Trifunctional vinylsilanes such as vinyltrimethoxysilane and vinyltriethoxysilane.
Trifunctional allylsilanes such as allyltrimethoxysilane, allyltriethoxysilane, allyldiethoxymethoxysilane, and allylethoxydimethoxysilane.
Trifunctional γ-methacrylopropylsilanes such as γ-methacrylopropyltrimethoxysilane, γ-methacrylopropyltrimethoxysilane, γ-methacrylopropyldiethoxymethoxysilane, and γ-methacrylopropylethoxydimethoxysilane.
Trifunctional 3-mercaptopropylsilanes such as 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane.
Trifunctional 3-aminopropylsilane such as 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane.
Trifunctional 3-glycidoxypropylsilanes such as 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane.
Trifunctional 3-phenylaminopropylsilane such as 3-phenylaminopropyltrimethoxysilane and 3-phenylaminopropyltriethoxysilane.
Trifunctional 3- (2-aminoethyl) aminopropylsilane such as 3- (2-aminoethyl) aminopropyltrimethoxysilane and 3- (2-aminoethyl) aminopropyltriethoxysilane.
Examples thereof include the above trifunctional silane compounds. The trifunctional silane compound means a silane compound having three alkoxy groups.

Examples thereof include bifunctional silane compounds such as dimethyldimethoxysilane and dimethyldiethoxysilane. The bifunctional silane compound means a silane compound having two alkoxy groups.
Examples thereof include monofunctional silane compounds such as trimethylethoxysilane, triethylmethoxysilane, triethylethoxysilane, triisobutylmethoxysilane, triisopropylmethoxysilane, and tri2-ethylhexylmethoxysilane. The monofunctional silane compound means a silane compound having one alkoxy group.

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 toner 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. It can be surface-layered on the surface of toner particles while being condensed. Condensation and surface layering are preferably carried out at 35 ° C. or higher for 60 minutes or longer.
It is preferable because the reaction residues 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 preferable that the toner particles have a surface layer containing an organosilicon-containing condensate. Some of the surface layers are present in a state in which particulate organosilicon-containing condensates are fixed. Further, a part of the hydrolyzed compound of the organosilicon compound may react with various polymerizable monomers such as a vinyl-based polymerizable monomer to form a crosslinked structure.

After obtaining the toner particles, it is preferable to carry out a cooling step of cooling the aqueous medium from a constant temperature. Regarding the cooling rate at that time, not only the polymerization method but also the overall method for producing toner particles will be described in a preferable range.
Focusing on the method of producing a toner for the purpose of crystallizing a crystalline material, for example, when the toner is produced by a pulverization method, suspension polymerization, or emulsion polymerization, the temperature reaches a temperature at which the crystalline material such as ester wax melts once. It often includes a step of raising the temperature and then cooling it to room temperature. Considering the cooling process, the molecular motion of the crystalline material liquefied by the temperature rise becomes slower as the temperature decreases, and crystallization starts when the temperature reaches the vicinity of the crystallization temperature. Further cooling promotes crystallization and completely solidifies at room temperature. According to the study by the present inventors, it was found that the amount of the crystalline material finally crystallized differs depending on the cooling rate. Specifically, the amount of crystals tended to increase when the crystalline material was cooled from a temperature above the melting point to 50 ° C. ± 5 ° C. at a rate of 5.0 ° C./min or more. Further, after cooling, it is preferably held at 50 ° C. ± 5 ° C. for 30 minutes or more. Toners produced under such cooling conditions tend to be excellent in tape peeling resistance and durable developability, and are therefore preferable.

The obtained toner particles can also be filtered, washed and dried by a known method. The toner particles may be used as they are as a toner, or may be used as a toner by mixing an external additive as described later as necessary and adhering the toner particles to the surface of the toner particles. It is also possible to insert a classification step in the manufacturing process (before mixing the inorganic fine powder) to cut the coarse powder and fine powder contained in the toner particles.

If necessary, an external agent such as a fluidizing agent may be mixed with the toner particles to obtain toner. As for the mixing method, a known method can be used, and for example, a Henschel mixer is a device that can be preferably used.
As the fluidizing agent, it is preferable that an inorganic fine powder having a number average primary particle size of preferably 4 to 80 nm, more preferably 6 to 40 nm is added to the toner particles. Inorganic fine powder is added to improve the fluidity of toner and homogenize the charge of toner particles. By treating the inorganic fine powder to be hydrophobic, the amount of charge in the toner can be adjusted, environmental stability can be improved, etc. It is also a preferable form to impart the function of. The method for measuring the number average primary particle size of the inorganic fine powder can be performed by using a photograph of the toner magnified by a scanning electron microscope.

As the inorganic fine powder, silica, titanium oxide, alumina and the like can be used. As the silica fine powder, for example, both a so-called dry method produced by vapor phase oxidation of a silicon halide or a dry silica called fumed silica, and a so-called wet silica produced from water glass or the like can be used. be. However, dry silica having less silanol groups on the surface and inside the silica fine powder and less production residue such as _{Na 2} O and SO ₃ ^{2- is preferable.} Further, in dry silica, it is also possible to obtain a composite fine powder of silica and other metal oxides by using other metal halogen compounds such as aluminum chloride and titanium chloride together with a silicon halogen compound in the manufacturing process. Including them.
The amount of the inorganic fine powder added is preferably 0.1 to 3.0 parts by mass with respect to 100 parts by mass of the toner particles. Within the above range, the fixability becomes good. The content of the inorganic fine powder can be quantified using fluorescent X-ray analysis and a calibration curve prepared from a standard sample.

It is preferable that the inorganic fine powder is hydrophobized because it can improve the environmental stability of the toner. The hydrophobization treatment makes it difficult for the inorganic fine powder to absorb moisture, makes the amount of charge of the toner particles uniform, and makes it difficult for toner to scatter. Treatment agents used for hydrophobization of inorganic fine powder include silicone varnishes, various modified silicone varnishes, silicone oils, various modified silicone oils, silane compounds, silane coupling agents, other organic silicon compounds, and organic titanium compounds. May be used alone, or two or more kinds may be used in combination.

To the toner, other additives such as fluororesin powder, zinc stearate powder, polyvinylidene fluoride powder and other lubricant powders; cerium oxide powder, silicon carbide powder, titanic acid, as long as they do not have a substantial adverse effect. Polishing agents such as strontium powder; fluidity-imparting agents such as titanium oxide powder and aluminum oxide powder; anti-caking agents; or organic fine particles and inorganic fine particles having opposite polarities can be used in small amounts as a developability improver. It is also possible to hydrophobize the surface of these additives before use.

Next, an example of an image forming apparatus capable of preferably using the toner of the present invention will be specifically described with reference to FIG.
In FIG. 1, 100 is a photosensitive drum, and a primary charging roller 117, a developing device 140 having a developing sleeve 102, a transfer charging roller 114, a cleaner 116, a register roller 124, and the like are provided around the photosensitive drum. The photosensitive drum 100 is charged to, for example, -600 V by the primary charging roller 117 (the applied voltage is, for example, an AC voltage of 1.85 kVpp and a DC voltage of -620 Vdc). Then, the photoconductor 100 is exposed by irradiating the photoconductor 100 with the laser beam 123 by the laser generator 121, and an electrostatic latent image corresponding to the target image is formed.
The electrostatic latent image on the photosensitive drum 100 is developed by a developer 140 with a one-component toner to obtain a toner image, and the toner image is transferred onto the transfer material by a transfer roller 114 abutted on the photoconductor via the transfer material. Will be done. The transfer material on which the toner image is placed is fixed by a conveyor belt 125 or the like.
It is carried to 26 and fixed on the transfer material. Further, the toner partially left on the photoconductor is cleaned by the cleaner 116.
Although the image forming apparatus for magnetic one-component jumping development is shown here, it may be used for any method of jumping development or contact development.

Next, a method for measuring each physical property of the toner of the present invention will be described.
<Melting point of crystalline materials such as wax>
The melting point can be obtained as the peak top temperature of the endothermic peak when measured by DSC. Measurements are made according to ASTM D 3417-99. For these measurements, for example, DSC-7 manufactured by PerkinElmer, DSC2920 manufactured by TA Instrument, and Q1000 manufactured by TA Instrument can be used. The melting points of indium and zinc are used for temperature correction of the device detector, and the heat of fusion of indium is used for the correction of calorific value.
Specifically, about 10 mg of a sample is precisely weighed, placed in an aluminum pan, and an empty aluminum pan is used as a reference, and the temperature rise rate is 10 in the measurement temperature range of 30 to 200 ° C. Measure at ° C / min. In the measurement, the temperature of the sample is once raised to 200 ° C. and held for 10 minutes, then the temperature is lowered to 30 ° C. at 10 ° C./min, and then the temperature is raised again at 10 ° C./min. The temperature at which the maximum endothermic peak of the DSC curve in the temperature range of 30 to 200 ° C. in the second temperature raising process is shown is defined as the melting point.

<(Measurement of weight average particle size (D4) and number average particle size (D1) of toner (particles))>
The weight average particle size (D4) and the number average particle size (D1) of the toner (particles) are the precision particle size distribution measuring device "Coulter Counter Multisizer 3" (registered trademark) by the pore electric resistance method equipped with an aperture tube of 100 μm. , Beckman Coulter) and the attached dedicated software "Beckman Coulter Multisizer 3 Version 3.51" (Beckman Coulter) for setting measurement conditions and analyzing measurement data, the number of effective measurement channels is 2. Measure with 15,000 channels, analyze the measurement data, and calculate.
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" (manufactured by Beckman Coulter) can be used.
Before performing measurement and analysis, the dedicated software is set as follows.
In the "Standard measurement method (SOM) change screen" of the dedicated software, the total count number in the control mode is set to 50,000 particles, the number of measurements is one, and the Kd value is "Standard particle 10.0 μm" (Beckman Coulter). Set the value obtained using (manufactured by the company). By pressing the threshold / noise level measurement button, the threshold and noise level are automatically set. Also, set the current to 1600 μA, the gain to 2, and the electrolyte to ISOTON II, and check the flush of the aperture tube after measurement.
In the "pulse to particle size conversion setting screen" of the dedicated software, the bin spacing is set to logarithmic particle size, the particle size bin is set to 256 particle size bins, and the particle size range is set to 2 μm or more and 60 μm or less.

The specific measurement method is as follows.
(1) Approximately 200 ml of the electrolytic aqueous solution is placed in a glass 250 ml round bottom beaker dedicated to Multisizer 3 and set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rpm. Then, the dirt and air bubbles in the aperture tube are removed by the "flash of the aperture tube" function of the dedicated software.
(2) Approximately 30 ml of the electrolytic aqueous solution is placed in a 100 ml flat-bottomed beaker made of glass, and "Contaminone N" (nonionic surfactant, anionic surfactant, and organic builder) as a dispersant is used as a dispersant for precise measurement of pH 7. Add about 0.3 ml of a diluted solution obtained by diluting a 10% by mass aqueous solution of a neutral detergent for cleaning a vessel, manufactured by Wako Pure Chemical Industries, Ltd.) with ion-exchanged water 3 times by mass.
(3) Two oscillators with an oscillation frequency of 50 kHz are built in with the phase shifted by 180 degrees, and are installed in the water tank of the ultrasonic disperser "Ultrasonic Dispersion System Tetora 150" (manufactured by Nikkaki Bios) with an electrical output of 120 W. A predetermined amount of ion-exchanged water is added, and about 2 ml of the Contaminone N is added into 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 aqueous 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. In ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted to be 10 ° C. or higher and 40 ° C. or lower.
(6) Using a pipette, 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 measurement 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. When the graph / volume% is set with the dedicated software, the "average diameter" of the analysis / volume statistical value (arithmetic mean) screen is the weight average particle size (D4), and the graph / number% is set with the dedicated software. The "average diameter" on the "analysis / number statistical value (arithmetic mean)" screen is the number average particle size (D1).

<Measurement of displacement of toner particles at a bending point by measuring the minute compression of toner and at a load 1.0 mN larger than the load at the bending point>
The micro-compression test is performed using an ultra-micro hardness tester ENT1100 manufactured by Elionix Inc. The indenter used is a flat indenter (made of diamond) with a tip surface of 20 μm × 20 μm. Measurement is performed while looking through the microscope attached to the ultra-micro hardness tester (width: 160 μm, height: 12).
Select one in which one toner particle is present at 0 μm). In order to eliminate the deviation amount error as much as possible, the toner having an average particle size of D1 of ± 0.2 μm is selected and measured. Arbitrary toner particles are selected from the measurement screen, but the major and minor diameters of the toner particles are measured using the software attached to the ultra-fine hardness tester ENT1100 as the means for measuring the particle size of the toner particles on the measurement screen. Then, the toner particles whose particle diameter [(major axis + minor axis) / 2] obtained from them is ± 0.2 μm of D1 are selected and measured.
A load is applied to the maximum load of 2.94 × 10 ^-4 N at a load speed of 9.80 × 10 ^-5 N / sec, and the load is applied until a bending point appears on the load displacement curve, as shown in FIG. The bending point is obtained in such a way as to be. The load at the obtained bending point is measured, and the arithmetic mean value of 100 toner particles is used as the load at the bending point. In addition, the number average particle diameter of the toner particles used in the measurement is calculated in advance by the above method.
Then, a load that is 1.0 mN larger than the load that causes the bending point obtained here is applied to obtain the displacement of the toner particles in the load displacement curve. Then, the ratio of the obtained displacement to the number average particle diameter (displacement / number average particle diameter × 100 (%)) is obtained. The arithmetic mean value of 100 toner particles is adopted.
The bending point means an inflection point on the load displacement curve. In the above measurement, the displacement proceeds with a first-order correlation with respect to the load, but when the toner starts plastic deformation, it deviates from the first-order correlation. As shown in FIG. 2, this point is detected and used as a bending point.

<Method of observing the cross section of toner particles with a transmission electron microscope (TEM) dyed with ruthenium>
Cross-section observation of toner particles with a transmission electron microscope (TEM) can be performed as follows.
Observation is performed by ruthenium staining the cross section of the toner particles. Crystalline materials are more likely to be dyed with ruthenium than amorphous resins such as binder resins. Therefore, the contrast becomes clear and the observation becomes easy. Because the amount of ruthenium atoms differs depending on the strength of dyeing,
In the strongly stained part, many of these atoms are present, and the electron beam does not pass through and becomes black on the observation image, and in the weakly dyed part, the electron beam easily passes through and becomes white on the observation image. ..
First, the toner is sprayed on the cover glass (Matsunami Glass Co., Ltd., Square Cover Glass Square No. 1) so as to form a single layer, and an osmium plasma coater (filgen Co., Ltd., OPC80T) is used to apply an Os film to the toner as a protective film. (5 nm) and naphthalene film (20 nm) are applied. Next, a PTFE tube (Φ1.5 mm × Φ3 mm × 3 mm) is filled with a photocurable resin D800 (JEOL Ltd.), and the cover glass is placed on the tube so that the toner comes into contact with the photocurable resin D800. Place quietly in the orientation. After irradiating light in this state to cure the resin, the cover glass and the tube are removed to form a cylindrical resin in which toner is embedded in the surface portion. 3. When the radius of the toner particles (weight average particle size (D4)) from the outermost surface of the cylindrical resin is 8.0 μm at a cutting speed of 0.6 mm / s by an ultrasonic ultramicrotome (Leica, UC7). Cut by a length of 0 μm) to obtain a cross section of the toner particles. Next, a thin section sample having a toner cross section was prepared by cutting to a film thickness of 250 nm. By cutting by such a method, a cross section of the central portion of the toner particles can be obtained.
_{The obtained flaky sample is stained for 15 minutes in a RuO 4} gas 500 Pa atmosphere using a vacuum electron staining apparatus (filgen, VSC4R1H), and STEM observation is performed using the STEM mode of TEM (JEOL, JEM2800).
Images are acquired with a STEM probe size of 1 nm and an image size of 1024 x 1024 pixel. Further, the contrast of the director control panel of the bright field image is adjusted to 1425, the contrast control is adjusted to 3750, the contrast of the image control panel is adjusted to 0.0, the brightness control is adjusted to 0.5, and the Gammma is adjusted to 1.00 to acquire a TEM image.

<Measurement of major axis R of toner particle cross section>
The major axis R of the toner particle cross section is measured based on the TEM image obtained by observing the toner particle cross section. The following domain A is measured for the cross section of the toner particles in which R (μm) satisfies 4 ≦ R ≦ 12.

<Measurement of the number of domains A and major axis r of crystalline material>
In the present invention, the major axis of domains A and B of the crystalline material is measured as follows.
Based on the TEM image obtained by observing the cross section of the toner particles, the longest diameter of the domain of the crystalline material is defined as r. Let the domain satisfying the relationship of the above formula (i) be domain A, and calculate the number of domains A per toner particle. For 100 toner particles, the number of domains A is calculated in the same manner, and the number of domains A of the toner is obtained by arithmetic mean.

<Ratio of toner particles in which domain B of crystalline material is present>
Similar to the measurement of the domain A major axis of the crystalline material described above, the number of domains B (small domains) in which the major axis r (μm) satisfies the above formula (ii) per one toner particle cross section is measured. This is performed for the cross sections of 100 toner particles, and the arithmetic mean value is taken as the number of domains B of the crystalline material per one toner particle cross section.
Further, the number of toner particles whose domain B is included in the center of gravity of the cross section of the toner particles is measured. The cross section of 100 toner particles is observed, and the ratio of the toner particles in which the domain B is present at the center of gravity of the cross section of the toner particles is calculated.

<Measurement of the presence ratio (10% magnetic material ratio) of the magnetic material to the total area occupied by the magnetic material in a region within 10% of the distance between the contour and the center of gravity of the cross section from the contour of the toner particle cross section>
The 10% magnetic material ratio is the ratio of the area of the magnetic material existing in the region within 10% of the distance between the contour and the center of gravity of the cross section to the total area occupied by the magnetic material from the contour of the toner particle cross section ( Area%).
The method for calculating the 10% magnetic material ratio is as follows.
In the above TEM image, the contour of the cross section of the toner particles is obtained by the method described later. The cross section of the toner particles to be observed shall exhibit a major axis R (μm) satisfying the relationship of 0.9 ≦ R / D4 ≦ 1.1 with respect to the weight average particle size (D4) of the toner. The contour of the cross section of the toner particles shall be along the surface of the toner particles observed in the TEM image.
Draw a line from the center of gravity of the toner particle cross section to a point on the contour of the toner particle cross section. On the line, the position of 10% of the distance between the contour and the center of gravity of the cross section is specified from the contour.
Then, this operation is performed for one round of the contour of the toner particle cross section, and a boundary line of 10% of the distance between the contour and the center of gravity of the cross section is clearly indicated from the contour of the toner particle cross section.
Based on the TEM image in which the 10% boundary line is clearly shown, the area occupied by the magnetic material (hereinafter referred to as A) in the cross section of one toner particle is measured. Further, the area occupied by the magnetic material (hereinafter referred to as B) existing in the region within 10% of the distance between the contour and the center of gravity of the cross section is measured from the contour of the toner particle cross section in the cross section of one toner particle. ..
For area measurement, the image processing software "Image-Pro Plus (Media)" is used.
(Cybernetics) ”can be used.
Next, the 10% magnetic material ratio in the cross section of one toner particle is calculated by the following formula.
10% magnetic material ratio in the cross section of one toner particle = {"B" / "A"} x 100 (%)
This is performed for the cross sections of 100 toner particles, and the arithmetic mean value thereof is taken as a 10% magnetic material ratio.

<Measurement of ester wax content from toner>
The ester wax content is described as an example because there are the following analysis methods. First, the toner is dissolved in chloroform, and the insoluble matter is removed by using, for example, Myshori Disc H-25-2 (manufactured by Tosoh Corporation). Next, the soluble component is introduced into a preparative HPLC (for example, LC-9130 NEXT preparative column [60 cm] manufactured by Nippon Analytical Industry Co., Ltd.) and fractionated to a molecular weight of less than 5000 and 5000 or more. In general, ester wax has a molecular weight of less than 5000. Therefore, for example, a pyrolyzer JPS-700 (manufactured by Nippon Analytical Industry Co., Ltd.) and GC-MASS (manufactured by Thermo Fisher Scientific) are combined with the above-mentioned preparative component to ester wax. To obtain the composition of. Further, by measuring each preparative component by ¹ H-NMR, the amount of ester wax with respect to the binder resin can be calculated.

<Measurement of peak molecular weight of tetrahydrofuran-soluble component of toner>
The peak molecular weight of the toner is measured by gel permeation chromatography (GPC) as follows.
First, the toner is dissolved in tetrahydrofuran (THF) at room temperature. Then, the obtained solution is filtered through a solvent-resistant membrane filter "Maeshori Disc" (manufactured by Tosoh Corporation) having a pore diameter of 0.2 μm to obtain a sample solution. The sample solution is adjusted so that the concentration of the component soluble in THF is 0.8% by mass. This sample solution is used for measurement under the following conditions.
Equipment: High-speed GPC equipment "HLC-8220GPC" [manufactured by Tosoh Corporation]
Column: LF-604 duplex eluent: THF
Flow velocity: 0.6 ml / min
Oven temperature: 40 ° C
Sample injection volume: 0.020 ml
In calculating the molecular weight of the sample, standard polystyrene resin (for example, trade name "TSK standard polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-" 10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500 ", manufactured by Tosoh Corporation) is used. In the obtained curve, the molecular weight of the maximum peak was defined as the peak molecular weight.

<Measurement of the amount of tetrahydrofuran insoluble in the resin component of toner>
1 g of toner is precisely weighed, charged into a cylindrical filter paper, and extracted with 200 ml of tetrahydrofuran (hereinafter, THF) in Soxhlet for 20 hours. Then, the cylindrical filter paper is taken out, vacuum dried at 40 ° C. for 20 hours, the residual mass is measured, and the tetrahydrofuran (THF) insoluble content of the resin component of the toner is calculated from the following formula.
The resin component of the toner is a component obtained by removing the magnetic powder, the charge control agent, the wax component, the external additive, and the pigment from the toner. At the time of measuring the THF insoluble matter, the THF insoluble matter is calculated based on the resin component in consideration of whether these inclusions are soluble or insoluble in THF.
THF insoluble (%) = (W2-W3) / (W1-W3-W4) x 100
However, W1: Mass of magnetic toner
W2: Residue mass
W3: Mass of components insoluble in THF other than the resin component of the magnetic toner
W4: Mass of THF-soluble components other than the resin component of the magnetic toner

Hereinafter, the present invention will be described in more detail with reference to Production Examples and Examples, but these are not limited to the present invention. Unless otherwise specified, the parts in the following formulations are based on mass.

<Manufacturing process of water-based medium B-1>
40.0 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. The mixture was heated with stirring to bring the temperature to 30 ° C.
Then, 10.0 parts of methyltriethoxysilane was added, and the mixture was stirred for 2 hours to obtain an aqueous medium B-1.

<Manufacturing process of water-based medium B-2>
40.0 parts of ion-exchanged water was weighed in a reaction vessel equipped with a stirrer and a thermometer, and the pH was adjusted to 8.0 with 10% by mass of hydrochloric acid. The mixture was heated with stirring to bring the temperature to 50 ° C.
Then, 10.0 parts of methyltriethoxysilane was added, and the mixture was stirred for 2 hours to obtain an aqueous medium B-2.

<Manufacturing process of water-based medium B-3>
10.0 parts of methyltriethoxysilane and 40.0 parts of ion-exchanged water were mixed to obtain an aqueous medium B-3.

<Production example of magnetic iron oxide>
50 liters of an iron sulfate aqueous solution containing 2.0 mol / L of Fe ²⁺ is mixed and stirred with 55 liters of a 4.0 mol / L sodium hydroxide aqueous solution to prepare a ferrous salt aqueous solution containing a ferrous hydroxide colloid. Obtained. This aqueous solution was kept at 85 ° C. and an oxidation reaction was carried out while blowing air at 20 L / min to obtain a slurry containing core particles.
The obtained slurry was filtered and washed with a filter press, and then the core particles were redispersed in water and reslurryed. To this reslurry liquid, sodium silicate having a silicon equivalent of 0.20 mass% per 100 parts of core particles is added, the pH of the slurry liquid is adjusted to 6.0, and stirring is performed to make magnetic oxidation having a silicon-rich surface. Iron particles were obtained. The obtained slurry was filtered and washed with a filter press, and further reslurryed with ion-exchanged water. 500 g (10% by mass with respect to magnetic iron oxide) of an ion exchange resin SK110 (manufactured by Mitsubishi Chemical) was added to this reslurry solution (solid content 50 g / L), and the mixture was stirred for 2 hours to perform ion exchange. Then, the ion exchange resin was filtered through a mesh to remove it, filtered and washed with a filter press, dried and crushed to obtain magnetic iron oxide having a number average particle size of 0.23 μm.

<Manufacturing of silane compounds>
30 parts of iso-butyltrimethoxysilane was added dropwise to 70 parts of ion-exchanged water with stirring. Then, this aqueous solution was maintained at pH 5.5 and a temperature of 55 ° C., and hydrolyzed by dispersing at a peripheral speed of 0.46 m / s for 120 minutes using a disper blade. Then, the pH of the aqueous solution was adjusted to 7.0, and the solution was cooled to 10 ° C. to stop the hydrolysis reaction. In this way, an aqueous solution containing a silane compound was obtained.

<Manufacturing of magnetic material 1>
100 parts of magnetic iron oxide was placed in a high-speed mixer (LFS-2 type manufactured by EarthTechnica Co., Ltd.), and 8.0 parts of an aqueous solution containing a silane compound was added dropwise over 2 minutes while stirring at a rotation speed of 2000 rpm. Then, it was mixed and stirred for 5 minutes. Then, in order to enhance the stickiness of the silane compound, the mixture was dried at 40 ° C. for 1 hour to reduce the water content, and then the mixture was dried at 110 ° C. for 3 hours to allow the condensation reaction of the silane compound to proceed. Then, it was crushed and passed through a sieve having an opening of 100 μm to obtain a magnetic substance 1.

<Manufacturing of magnetic material 2>
_{1.1 equivalents of caustic soda solution with respect to iron element, P 2} O ₅ with phosphorus element equivalent of 0.12% by mass with respect to iron element, and silicon element with respect to iron element in ferrous sulfate aqueous solution. An aqueous solution containing ferrous hydroxide was prepared by mixing _{SiO 2} in an amount of 0.55% by mass in terms of conversion. Aqueous solution p
H was set to 7.5, and an oxidation reaction was carried out at 85 ° C. while blowing air to prepare a slurry liquid having seed crystals.
Next, a ferrous sulfate aqueous solution was added to this slurry liquid so as to have 1.1 equivalents with respect to the initial alkali amount (sodium component of caustic soda), and then the slurry liquid was maintained at pH 7.6 and air was blown into the slurry liquid. While proceeding with the oxidation reaction, a slurry liquid containing magnetic iron oxide was obtained. After filtering and washing, this water-containing slurry liquid was once taken out. At this time, a small amount of a water content sample was taken and the water content was measured. Next, this water-containing sample is put into another aqueous medium without being dried, and the pH of the redispersion liquid is adjusted to about 4.8 by redispersing with a pin mill while stirring and circulating the slurry. Then, while stirring, 1.5 parts of n-hexyltrimethoxysilane was added to 100 parts of magnetic iron oxide (the amount of magnetic iron oxide was calculated as the value obtained by subtracting the water content from the water content sample), and hydrolysis was performed. rice field. After that, the mixture was sufficiently stirred and dispersed by a pin mill while circulating the slurry, and the pH of the dispersion was adjusted to 8.6 to perform hydrophobization treatment. The obtained hydrophobic magnetic powder is filtered with a filter press, washed with a large amount of water, dried at 100 ° C. for 15 minutes and 90 ° C. for 30 minutes, and the obtained particles are crushed to obtain volume average particles. A magnetic material 2 having a diameter of 0.21 μm was obtained.

<Manufacturing of toner particles 1>
450 parts of 0.1 mol / L-Na ₃ PO ₄ aqueous solution was added to 720 parts of ion-exchanged water and heated to 60 ° C., and then _{67.7 parts of 1.0 mol / L-CaCl 2} aqueous solution was added. , An aqueous medium containing a dispersion stabilizer was obtained.
-Styrene 79.0 parts-n-butyl acrylate 21.0 parts-Divinylbenzene 0.6 parts-Iron complex of monoazo dye (T-77: manufactured by Hodoya Chemical Co., Ltd.) 1.5 parts-Magnetic material 1 90.0 Part-Atypical Saturated Polyester Resin 5.0 parts (Acrystalline saturation obtained by condensation reaction of ethylene oxide (2 mol) adduct of bisphenol A and propylene oxide (2 mol) adduct of bisphenol A with terephthalic acid. Polyester resin; Mw = 9500, acid value = 2.2 mgKOH / g, glass transition temperature =
68 ℃)
The above formulation was treated with Cavitron (manufactured by Eurotech) at a peripheral speed of the rotor at 30 m / s for 1 hour, and uniformly dispersed and mixed to obtain a magnetic material-containing monomer.
15.0 parts of dibehenyl sebacate (ester wax 1) was mixed therewith as an ester wax and dissolved to obtain a monomer composition.
The aqueous medium in the monomer composition was charged in, 60 ° C., and stirred at 12000 rpm 10 min under _{N 2} atmosphere at T.K. homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) and granulated. Then, 5.0 parts of the polymerization initiator t-butylperoxypivalate was added while stirring with a paddle stirring blade, the temperature was raised to 70 ° C., and the reaction was carried out for 4 hours.
After completion of the reaction, a 1N aqueous sodium hydroxide solution was added to the suspension, the pH of the suspension was adjusted to 9.0, and then 40.0 parts of the aqueous medium B-1 was added. Then, after holding the suspension at 70 ° C. for 2 hours, the temperature of the suspension was raised to 100 ° C. and held for 2 hours.
Then, as a cooling step, water at room temperature was added to the suspension, the suspension was cooled from 100 ° C. to 50 ° C. at a rate of 100 ° C./min, and then held at 50 ° C. for 100 minutes.
Then, hydrochloric acid was added to the suspension and the suspension was thoroughly washed to dissolve the dispersion stabilizer, which was then filtered and dried to obtain toner particles 1. The formulations are shown in Table 2, and the physical characteristics of the toner are shown in Table 3.

<Manufacturing of toner particles 2 to 14 and comparison toner particles 1 to 6>
In the production of the toner 1, the type and number of esters wax and hydrocarbon, auxiliary dissolution conditions, cooling conditions, and type and number of aqueous media are changed as shown in Table 2, and the binder resin has a desired molecular weight and the desired molecular weight and number of copies. Toner particles 2 to 14 and comparative toner particles 1 to 6 were produced in the same manner except that the amounts of the initiator and divinylbenzene were changed so as to be insoluble in THF. When a hydrocarbon was used, the hydrocarbon was added at the same time as the ester wax was added.
The obtained toner particles were used as they were as toner. The formulations are shown in Table 2, and the physical characteristics of the toner are shown in Table 3.

<Manufacturing of comparative toner particles 7>
In the production of the comparative toner 6, the ester wax was not added, and the amounts of the initiator and divinylbenzene were changed so that the binder resin had a desired molecular weight and a THF insoluble content. Immediately after the temperature was raised to 70 ° C. and the reaction was carried out for 4 hours, 35 parts of the aqueous medium B-3 was added, and a 1N aqueous sodium hydroxide solution was added to the suspension to adjust the pH of the suspension. Adjusted to 9.0. Then, after holding the suspension at 70 ° C. for 2 hours, the temperature of the suspension was raised to 100 ° C. and held for 2 hours. Comparative toner particles 7 were produced in the same manner except for the above changes.
The obtained toner particles were used as they were as toner. The formulations are shown in Table 2, and the physical characteristics of the toner are shown in Table 3.

<Manufacturing of comparative toner particles 8>
_{450 parts of 0.1 M-Na 3} PO ₄ aqueous solution was added to 720 parts of ion-exchanged water and heated to 60 ° C., and then _{67.7 parts of 1.0 M-CaCl 2} aqueous solution was added to make an aqueous system containing a dispersant. I got the medium.
・ 78.0 parts of styrene ・ 22.0 parts of n-butyl acrylate ・ 0.48 parts of divinylbenzene ・ Iron complex of monoazo dye (T-77: manufactured by Hodoya Chemical Co., Ltd.) 1.5 parts ・ Magnetic material 2 90.0 Part: 5.0 parts of amorphous saturated polyester resin (Atypical saturated polyester resin similar to that used in the production of toner particles 1)
The above formulation was uniformly dispersed and mixed using an attritor (Mitsui Miike Machinery Co., Ltd.) to obtain a monomer composition. This monomer composition is heated to 60 ° C., 15 parts of HNP51 is added and mixed therein, and after dissolution, the polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) 4
.. Five parts were dissolved.
The aqueous medium of the above monomer composition was charged in, 60 ° C., and stirred at 12000 rpm 10 min at TK Homomixer (Tokushu Kika Kogyo Co., Ltd.) under _{N 2} atmosphere and granulated. Then, the polymer dispersion was obtained by reacting at 70 ° C. for 5 hours while stirring with a paddle stirring blade. After that, stirring was stopped, and the polymer dispersion was charged into a carrier gas input pipe, a vent pipe, and a distillation vessel equipped with a condenser for cooling and condensing the gas discharged from the vent pipe. When 100 parts / hr (steam pressure 120 kPa) of pure saturated steam was introduced into the polymer dispersion, 10 minutes after the start of introduction of the saturated steam, distillates began to appear from the vent pipe via the condenser. Steam distillation was performed starting from the time when the distillate began to appear. After continuing the distillation for 5 hours from there, the introduction of pure saturated steam was stopped and the mixture was cooled. Then, after washing by adding hydrochloric acid, it was filtered, crushed and dried to obtain toner particles 8 for comparison.
100 parts of the comparative toner particles 8 and 0.8 parts of hydrophobic silica having an average primary particle size of 12 nm are mixed with a Henshell mixer (Mitsui Miike Machinery Co., Ltd.) to obtain a weight average particle size (D4). A 7.8 μm comparative toner 8 was obtained.
Table 3 shows the physical characteristics of the toner.

表中、ＨＮＰ５１は、日本精蝋株式会社製のパラフィンワックスである。

In the table, HNP51 is a paraffin wax manufactured by Nippon Seiro Co., Ltd.

<Example 1>
(Peel off the tape)
The following evaluation was performed using the toner 1.
FOX RIVER BOND paper (110 g / m ² ) was used as the fixing medium, and LBP3410 (a monochrome laser beam printer manufactured by Canon Inc.) modified to adjust the development bias was used as the image forming apparatus. The evaluation image is a line image. By shaking the development bias and setting the reflection density of the image part high, the amount of toner on the image is increased, and by using thick paper with relatively large surface irregularities, the recesses of the paper and the lower layer part of the toner layer are used in the fixing process. Since the toner is less likely to melt, it can be evaluated strictly against peeling. As for the evaluation environment, it is difficult for the fuser to warm up at low temperatures, resulting in a strict evaluation.

The evaluation procedure is shown below. First, the image forming apparatus was left overnight in a low temperature and low humidity environment (temperature 15 ° C. and humidity 10%). Then, using FOX RIVER BOND paper, a horizontal line image adjusted for development bias is printed so that the line width becomes 180 μm. Further, after leaving it for 1 hour in a low temperature and low humidity environment, a polypropylene tape (Klebeband 19 mm × 10 mm manufactured by tessa) was attached to the horizontal line image and slowly peeled off. The image after peeling was visually observed and observed under a microscope, and evaluated according to the following evaluation criteria. The evaluation results are shown in Table 4.
A; No defect B; Slight defects are visible but not visible
C; There are slight defects that can be visually recognized.
D; There is a visually recognizable defect and there is a break in the line E; There are many breaks in the line

(Durability evaluation)
The LBP-3410 as an image forming apparatus was evaluated by mounting a sleeve having a diameter of 10 mm as a developing sleeve. The above conditions are small for a developing sleeve, and the amount of toner loaded on the developing sleeve is also reduced to about half of the usual amount. All of the above modifications are in the direction of increasing the pressure between the toner and the developing sleeve in the durability development evaluation, and tend to induce fusion to the developing sleeve.
Further, when the toner is stored in a high temperature environment for a long period of time, a crystalline material such as a mold release agent may exude to the surface, and the image quality may change. For this reason, in order to make a strict evaluation, a toner that had been left in advance in an atmosphere of 40 ° C. for 30 days was used. Durability can be strictly evaluated by combining these conditions.
Toner 1 was evaluated using the above LBP-3410. As an evaluation procedure, after leaving the image forming apparatus overnight in a high temperature and high humidity environment (32.5 ° C. 80%), 15,000 horizontal line images with a printing rate of 1% are output in the intermittent mode under the above environment, and further solid. Three images were output. The image quality was evaluated by measuring the densities of the last three solid images at four corners with a Macbeth reflection densitometer and comparing these 12 numerical values with the following criteria. The evaluation results are shown in Table 4.
A: The difference between the maximum and minimum values of image density is less than 0.1 B: The difference between the maximum and minimum values of image density is 0.1 or more and less than 0.2 C: The difference between the maximum and minimum values of image density Is 0.2 or more and less than 0.3 D: The difference between the maximum value and the minimum value of the image density is 0.3 or more

(Fixed film stain)
The fixing film stain was evaluated by observing the fixing film and the image after the durability test. The evaluation results are shown in Table 4.
A: No stain on the fixing film B: Slight fusion is seen on the fixing film C: Slight fusion is seen on the fixing film and slight stain is seen on the back surface of the image D: Fusion is seen on the fixing film There is a visible stain on the back of the image.

<Examples 2 to 14>
An image drawing test was performed in the same manner as in Example 1 except that the toner 1 was changed to toners 2 to 14 in Example 1. The evaluation results are shown in Table 4. In addition, Examples 13 and 14 are Reference Examples 13 and 14, respectively.

<Comparative Examples 1 to 8>
An image drawing test was carried out in the same manner as in Example 1 except that the toner 1 was changed to the comparison toners 1 to 8 in Example 1. The evaluation results are shown in Table 4.

100: Photosensitive drum (image carrier, charged body), 102: Development sleeve (toner carrier), 114: Transfer charging roller (transfer member), 116: Cleaner 117: Primary charging roller (contact charging member), 121 : Laser generator (latent image forming means, exposure device), 124: Register roller, 125: Conveying belt, 126: Fixer, 140: Developer, 141: Stirring member

Claims (6)

A black toner having toner particles containing a binder resin, a crystalline material, and a black colorant.
The load at the bending point of the load displacement curve by the micro-compression measurement of the black toner is 1.0 mN or more and 3.0 mN or less.
The peak molecular weight of the tetrahydrofuran-soluble component of the black toner is 5000 or more and 40,000 or less.
The amount of tetrahydrofuran insoluble in the resin component of the black toner is 3% by mass or more and 50% by mass or less in the resin component of the black toner.
In the cross section of the toner particles observed by a transmission electron microscope,
When the major axis of the cross section of the toner particles is R (μm) and the major axis of the domain of the crystalline material is r (μm),
Regarding the toner particle cross section in which R (μm) satisfies 4 ≦ R ≦ 12, the domain of the crystalline material satisfying the following formula (i) is defined as domain A, and the number of the domains A per one toner particle cross section is determined. A black toner characterized by having 50 or more and 300 or less.
(I) 5.0 × 10 ^-4 ≦ r / R ≦ 7.0 × 10 ^-2 In the micro-compression measurement of the black toner, the ratio of the displacement of the toner particles to the number average diameter D1 of the black toner at a load further 1.0 mN larger than the load at the bending point is 20% or more and 60% or less. Item 1. The black toner according to Item 1. The crystalline material contains at least ester wax and
The black toner according to claim 1 or 2, wherein the ester wax has a melting point of 65.0 ° C. or higher and 85.0 ° C. or lower. The crystalline material contains at least ester wax and
The black toner according to any one of claims 1 to 3 , wherein the content of the ester wax is 3.0 parts by mass or more and 25.0 parts by mass or less with respect to 100 parts by mass of the binder resin. The crystalline material contains at least ester wax and
The black toner according to any one of claims 1 to 4 , wherein the ester wax is a polyfunctional ester wax having two or more ester bonds in the structure. The black toner according to any one of claims 1 to 5 , wherein the black colorant contains a magnetic substance.

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