JP2018040967A - toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner having stable chargeability and high durability even at high speed and when printing a large number of sheets. SOLUTION: The toner has toner particles containing a binder resin, and (1) the number average particle diameter (D1) is 70 nm or more and 200 nm or less, and the roundness is on the surface of the toner particles. Spherical particles having a value of 0.80 or more and (2) hydrotalcite particles are present, and in the toner, the adhesion rate of the hydrotalcite particles is 15% or more and 80% or less, and the toner particles. The friction-charged array of the spherical particles and the hydrotalcite particles is characterized in that the order is the toner particles, the spherical particles, and the hydrotalcite particles from the negative side. [Selection diagram] None

Description

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

In recent years, with the diversification of use environments of electrophotographic apparatuses, there is a demand for apparatuses capable of stably obtaining high-quality images even in environments with different temperatures and humidity. Furthermore, high durability without a deterioration in image quality is required even when copying or printing a large number of sheets in a harsh environment. In order to obtain a stable image quality regardless of the use environment, a toner that exhibits stable chargeability regardless of temperature and humidity is required.
Patent Document 1 discloses that a toner having excellent charging stability can be obtained by externally adding hydrotalcite particles to the toner. In particular, when the toner is a negatively charged toner, the hydrotalcite has a reverse polarity with respect to the toner particles, and the effect of uniformizing the toner charge by the action of microcarriers is shown. Although the above prior art toners have excellent characteristics, they still have room for improvement from the viewpoint of high durability in harsh environments. Specifically, when printing a large number of sheets at high speed, the hydrotalcite particles may be detached from the toner particles, and as a result, the members in the developing device may be contaminated.
In Patent Document 2, hydrotalcite particles surface-treated with oil are adhered onto toner particles having an appropriate particle size distribution, thereby suppressing toner fusion to each member in the image forming apparatus, and A method for suppressing fusion in the regulating member is shown. However, when oil-treated hydrotalcite particles are used, agglomeration of hydrotalcite particles due to oil treatment may occur, and the photoconductor may be contaminated when printing a large number of sheets at high speed. There is. There is still room for improvement from the viewpoint of suppressing the separation and aggregation of the hydrotalcite particles from the toner particles and having high durability at a high speed and no deterioration in image quality even when printing many sheets.
Patent Document 3 discloses a method of suppressing the separation of the hydrotalcite particles from the toner particles by internally adding the hydrotalcite particles to the toner. However, in the method in which other additives such as silica are externally added to the toner particles in which the hydrotalcite particles are internally added, the ratio of the hydrotalcite particles located on the outermost surface of the toner tends to decrease. Moreover, in the method by internal addition, there exists a tendency for the microcarrier action of hydrotalcite particles to be suppressed. As a result, it is difficult to maximize the excellent charging characteristics of hydrotalcite. From the viewpoint of achieving both high charging stability and high durability, it can be said that there is still a problem.

Japanese Patent No. 3684103 Japanese Patent No. 4378235 JP 2009-180870 A

  The present invention aims to solve the above problems. That is, an object of the present invention is to provide a toner having stable chargeability and high durability when printing a large number of sheets at high speed.

As a result of intensive studies, the present inventors have found that the above-described problems can be solved by the following toner.
That is, the toner of the present invention is
A toner having toner particles containing a binder resin,
On the surface of the toner particles,
(1) Spherical particles having a number average particle diameter (D1) of 70 nm to 200 nm and a roundness of 0.80 or more, and
(2) Hydrotalcite particles are present,
In the toner, the fixing rate of the hydrotalcite particles is 15% or more and 80% or less,
In the triboelectric charging train of the toner particles, the spherical particles, and the hydrotalcite particles, the toner particles, the spherical particles, and the hydrotalcite particles are in this order from the negative polarity side.
The toner is characterized by the above.

  According to the present invention, it is possible to provide a toner having stable chargeability and high durability even when printing a large number of sheets at high speed.

1 is a schematic cross-sectional view illustrating an overall configuration of an image forming apparatus. It is a schematic sectional drawing of a process cartridge.

The toner of the present invention is formed on the toner particle surface.
(1) Spherical particles having a number average particle diameter (D1) of 70 nm to 200 nm and a roundness of 0.80 or more, and
(2) Hydrotalcite particles are present,
In the toner, the fixing rate of the hydrotalcite particles is 15% or more and 80% or less,
In the triboelectric charging train of the toner particles, the spherical particles, and the hydrotalcite particles, the toner particles, the spherical particles, and the hydrotalcite particles are in this order from the negative polarity side.
It is characterized by that.

  In the present invention, the combination of the spherical particles and the hydrotalcite particles can achieve both charging stability and high durability at a high level. Specifically, by suppressing desorption without hindering the microcarrier function of the hydrotalcite particles, it is possible to suppress contamination of members in the developing machine while having high charge stability. .

  The mechanism related to the above effect is estimated as follows.

  The present invention is characterized in that the toner particles, the spherical particles, and the hydrotalcite particles are in this order from the negative polarity side in the triboelectric charging train of the toner particles, the spherical particles, and the hydrotalcite particles. To do.

  Since the triboelectric charge train of the spherical particles is located between the toner particles and the hydrotalcite particles, an electrostatic cohesive force acting between the hydrotalcite particles and the spherical particles can cause the hydrotalcite particles and the hydrotalcite particles to This is considered to be smaller than the electrostatic cohesive force acting between the toner particles. Accordingly, it is considered that the aggregation of these materials on the surface of the toner particles can be suppressed without inhibiting the adhesion of the hydrotalcite particles to the toner particles.

  Further, since the triboelectric charge train of the spherical particles is on the negative polarity side of the hydrotalcite particles, an electrostatic adhesive force acts between the hydrotalcite particles and the spherical particles. When the spherical particles and the hydrotalcite particles are appropriately diffused and adhered onto the toner particles, the adhesion force of the hydrotalcite particles to the toner particles is increased by electrostatic contact with the spherical particles. Strengthened by adhesion. As a result, desorption of the hydrotalcite particles from the toner particles is suppressed. By suppressing desorption by electrostatic adhesion, compared to the case where desorption is suppressed by physical embedding, the microcarrier-like function of hydrotalcite particles between toner particles is not inhibited, Good charging characteristics can be obtained. As a result, even when the toner in the developing machine is rubbed vigorously during printing at a high speed and a large number of sheets, the separation of the hydrotalcite particles from the toner particles is suppressed, and a good charging effect is maintained. From the above, it is considered that the above-described high charging stability and high durability can be achieved at the same time.

  The triboelectric charge trains of the toner particles, the spherical particles, and the hydrotalcite particles were obtained by measurement of zero point charge using a standard carrier described later. A larger difference in zero point charge between the toner particles and the hydrotalcite particles is preferable because the adhesion of the hydrotalcite particles to the toner increases. The numerical difference is preferably 35 μC / g or more, and more preferably 42 μC / g or more.

  Hereinafter, the present invention will be specifically described.

  In the present invention, the spherical particles have a number average particle diameter (D1) of 70 nm or more and 200 nm or less.

  When the number average diameter is less than 70 nm, the spherical particles are likely to be embedded in the toner particles, and the durability tends to be poor. Further, when other external additives are included, the interaction between the spherical particles and the hydrotalcite particles tends to be hindered.

  When the number average diameter is larger than 200 nm, the detachment of the spherical particles from the toner particles is likely to occur, and the contamination of the members in the developing device due to the spherical particles and the hydrotalcite particles is likely to occur.

  When the number average particle diameter (D1) of the spherical particles is 70 nm or more and 200 nm or less, the interaction between the spherical particles and the hydrotalcite particles is likely to occur, and the above-described effects can be obtained.

  In the present invention, the roundness of the spherical particles is 0.80 or more.

  When particles with a roundness of less than 0.80 are used, the effect of suppressing member contamination in the developing device cannot be obtained. This is probably because the particles are difficult to diffuse uniformly on the toner particles.

  In the present invention, the fixing rate of the hydrotalcite particles in the toner needs to be 15% or more and 80% or less.

  Although details of the method for measuring the fixing rate of hydrotalcite particles will be described later, the toner is dispersed in an aqueous solution, filtered and washed after centrifugation, and the ratio of hydrotalcite particles remaining in the toner is defined as the fixing rate. Defined.

  When the fixing rate is less than 15%, the hydrotalcite particles are detached from the toner particles, so that member contamination in the developing machine is likely to occur. When the fixing rate is greater than 80%, the charging stability of the toner tends to decrease. This is probably because the microcarrier-like action of the hydrotalcite particles is suppressed.

  The method for controlling the fixing rate of the hydrotalcite particles to the above range is not particularly limited, but when achieved by external addition, it can be achieved by adjusting the power and processing time during the external addition mixing process. it can. The fixing rate can be increased by increasing the power during the external additive mixing process or by increasing the processing time.

  Here, in the toner that does not contain the spherical particles, the effect of the present invention cannot be obtained when the fixing rate of the hydrotalcite particles in the toner is controlled within the aforementioned range. The fixing rate of the hydrotalcite particles defined here is a value in the initial state of the toner. In general, when a load is applied to the toner by stirring or the like at the time of printing at a high speed and a large number of sheets, the adhesion state of the fine particles existing on the toner surface is considered to be different from the initial state. In the present invention, in order to maintain appropriate adhesion of the hydrotalcite particles to the toner particles when printing at a high speed and a large number of sheets, an electrostatic adhesion force between the spherical particles and the hydrotalcite particles is used. Is considered necessary to work.

  In the present invention, the formation of aggregates derived from hydrotalcite particles can be suppressed as described above by controlling the triboelectric charge train of the spherical particles. On the other hand, when the hydrotalcite particles and the spherical particles are added to the toner particle surface by a mixing process, the formation of aggregated particles can be further suppressed by performing the mixing step as follows.

That is, in a mixing step of adding spherical particles and hydrotalcite particles to toner particles, 1) a first mixing step of mixing the toner particles and the spherical particles to obtain a mixture;
2) It is preferable to have a second mixing step of mixing the mixture and the hydrotalcite particles to obtain the toner. Aggregated particle formation can be suppressed by dividing the step of adding spherical particles to the toner particles and the step of adding hydrotalcite particles into two stages. In addition, the spherical particles are added to the toner particles and mixed, and then the hydrotalcite particles are added and mixed to increase the proportion of the hydrotalcite particles located on the outermost surface of the toner. The grant effect can be utilized to the maximum. As a result, a toner having high charging stability can be obtained.

  The spherical particles used in the present invention must be located on the negative polarity side of the hydrotalcite particles and on the positive polarity side of the toner particles on the triboelectric train. The spherical particles satisfying the above relationship are not particularly limited, including organic substances and inorganic substances. Examples of inorganic substances include particles such as silica, titania, and alumina, or composite oxides thereof. As the organic substance, for example, a homopolymer or copolymer of a monomer component used for a binder resin for toner such as styrene, acrylic acid, methyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate can be used.

  Among these, hydrophobized silica particles are preferable from the viewpoint of chargeability. Examples of the silica particles include wet silica produced from water glass and sol-gel silica particles produced by a sol-gel method. A sol-gel silica particle that has been hydrophobized is particularly preferred because of its high circularity and sharp particle size distribution. Examples of the hydrophobizing agent include unmodified silicone varnish, various modified silicone varnishes, unmodified silicone oil, various modified silicone oils, silane compounds, silane coupling agents, other organic silicon compounds, and organic titanium compounds. These treatment agents may be used alone or in combination.

  The addition amount of the spherical particles is 0.01 parts by mass or more and 3.00 parts by mass or less (more preferably 0.03 parts by mass or more and 1.0 parts by mass or less) with respect to 100 parts by mass of the toner particles. When the addition amount is 0.01 parts by mass or more, the effect of the present invention is sufficiently exerted. When the addition amount is 3.00 parts by mass or less, the spherical particles are not detached from the toner particles. Further, the ratio of the amount of the spherical particles to the amount of the hydrotalcite particles added is preferably 0.1 or more and 1.7 or less. In the said range, interaction of a spherical particle and hydrotalcite particle | grains tends to arise, and the effect of this invention is easy to be acquired.

  As hydrotalcite particles used in the present invention, those represented by the following structural formula can be used.

（２価又は３価金属は、少なくとも１種以上存在し、異なる元素を複数含有する固溶体であっても構わない。また、１価の金属を微量含んでも構わない。ただし、０＜ｘ≦０．５、ｙ＝１−ｘ、ｍ≧０、Ｍ²⁺：少なくともＭｇ、Ｚｎ、Ｃａ、Ｂａ、Ｎｉ、Ｓｒ、Ｃｕ、Ｆｅから選ばれる２価の金属イオン、Ｍ³⁺：少なくともＡｌ、Ｂ、Ｇａ、Ｆｅ、Ｃｏ、Ｉｎから選ばれる３価の金属イオン、Ａ^n-：ｎ価のアニオンで、ＣＯ₃ ^2-、ＯＨ^-、Ｃｌ^-、Ｉ^-、Ｆ^-、Ｂｒ^-、ＳＯ₄ ^2-、ＨＣＯ₃ ^2-、ＣＨ₃ＣＯＯ^-、ＮＯ₃ ^-が挙げられる。単独あるいは複数存在しても構わない。）

(The divalent or trivalent metal may be a solid solution containing at least one or more different elements and containing a plurality of different elements. It may also contain a small amount of a monovalent metal. However, 0 <x ≦ 0. .5, y = 1−x, m ≧ 0, M ²⁺ : at least a divalent metal ion selected from Mg, Zn, Ca, Ba, Ni, Sr, Cu, Fe, M ³⁺ : at least Al, B , Ga, Fe, Co, 3-valent metal ion selected from in, a ^n-: in n-valent _{^{anion, CO 3 2-, OH -,}} Cl -, I -, F -, Br -, SO 4 2 _{^{-, HCO 3 2-, CH 3}} COO -, nO 3 -. is mentioned are may be singly or in multiple exist).

The divalent metal ion M ²⁺ preferably contains a large amount of magnesium, and the trivalent metal ion M ³⁺ preferably contains a large amount of aluminum.

  Moreover, it is preferable that the hydrotalcite particle has water in the molecule | numerator, and it is more preferable that it is 0.1 <m <0.6 in General formula (1).

  The number average particle diameter (D1) of the hydrotalcite particles used in the present invention is preferably 0.1 μm or more and 1.00 μm or less, and more preferably 0.2 μm or more and 0.8 μm or less. In the case of 0.1 μm or more, the interaction between the hydrotalcite particles and the spherical particles tends to occur. When it is 1.00 μm or less, the hydrotalcite particles are not excessively detached from the toner particles, and the effects of the present invention can be easily obtained. The number average particle diameter of the hydrotalcite particles is preferably larger than the number average particle diameter of the spherical particles. In this case, it is considered that the effect of suppressing the removal of the hydrotalcite particles by the spherical particles becomes more remarkable.

  The hydrotalcite particles used in the present invention are preferably hydrophobized with a surface treatment agent in order to stabilize the environment. As the surface treatment agent, higher fatty acids, coupling agents, esters, oils such as silicone oil can be used. Of these, higher fatty acids are preferably used, and specific examples include stearic acid, oleic acid, and lauric acid.

  The amount of the hydrotalcite particles added to the toner particles is 0.01 parts by weight or more and 3.00 parts by weight or less (more preferably 0.1 parts by weight or more and 1.0 parts by weight or less) with respect to 100 parts by weight of the toner particles. It is. When the addition amount is 0.01 parts by mass or more, the effect of the present invention is sufficiently exhibited. When the addition amount is 3.00 parts by mass or less, the environmental stability is sufficient.

  In the toner of the present invention, in addition to the spherical particles and hydrotalcite particles, organic or inorganic fine particles generally known as external additives can be added. In this case, the total amount of inorganic fine particles and organic fine particles containing hydrotalcite particles is preferably 0.5 to 5.0 parts by mass with respect to 100 parts by mass of the toner particles. If the total amount of the fine particles is 0.5 parts by mass or more, the fluidity of the toner is good, and if the total amount of the fine particles is 5.0 parts by mass or less, contamination of the member due to the toner and external additives can be suppressed.

  As the inorganic fine particles to be externally added to the toner particles, for example, inorganic fine particles selected from silica, alumina, titania or a composite oxide thereof can be used in addition to the spherical particles and the hydrotalcite particles. Examples of the composite oxide include silica alumina composite oxide, silica titania composite oxide, strontium titanate fine powder, and the like. As these external additives, it is preferable to use the surface after hydrophobizing. Examples of the hydrophobizing treatment include treatment with an organosilicon compound, silicone oil, long chain fatty acid and the like.

  Examples of the organosilicon compound include hexamethyldisilazane, trimethylsilane, trimethylethoxysilane, isobutyltrimethoxysilane, trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, and hexamethyl. Examples thereof include disiloxane. These are used in one kind or a mixture of two or more kinds.

  Examples of the silicone oil include dimethyl silicone oil, methylphenyl silicone oil, α-methylstyrene modified silicone oil, chlorophenyl silicone oil, and fluorine modified silicone oil.

  Further, the toner used in the present invention may further contain other additives, for example, a lubricant powder such as Teflon (registered trademark) powder, zinc stearate powder, and polyvinylidene fluoride powder within a range that does not substantially adversely affect the toner. Abrasives such as cerium oxide powder and silicon carbide powder, anti-caking agents, and organic fine particles can also be used. These additives can also be used after hydrophobizing the surface. Examples of the organic fine particles include a homopolymer or a copolymer of monomer components used in a binder resin for toner such as styrene, acrylic acid, methyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate by, for example, emulsion polymerization or spray drying. Coalescence can be used.

  As a mixer for externally adding an external additive to toner particles, FM mixer (manufactured by Nippon Coke Industry Co., Ltd.), super mixer (manufactured by Kawata Corp.), nobilta (manufactured by Hosokawa Micron Corp.), hybridizer (manufactured by Nara Machinery Co., Ltd.), etc. Is mentioned.

  In addition, as a sieving device used for sieving coarse particles after external addition, Ultrasonic (manufactured by Sakae Sangyo Co., Ltd.); Resona sieve, Gyroshifter (Tokuju Kosakusha Co., Ltd.); Vibrasonic System (manufactured by Dalton Co.); Soni Clean (manufactured by Shinto Kogyo Co., Ltd.); turbo screener (manufactured by Turbo Kogyo Co., Ltd.); micro shifter (manufactured by Hadano Sangyo Co., Ltd.) and the like.

  Examples of the binder resin contained in the toner particles of the present invention include polystyrene; homopolymers of styrene substitution products such as poly-p-chlorostyrene and polyvinyltoluene; styrene-p-chlorostyrene copolymers and styrene-vinyltoluene copolymers. Polymer, styrene-vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene- Styrene such as vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer Copolymer; acrylic resin; Acrylic resins; polyvinyl acetate; silicone resins; polyester resins; polyamide resin; furan resins, epoxy resins, xylene resins. These resins are used alone or in combination.

  As the main component of the binder resin, a polyester resin and / or a styrene copolymer which is a copolymer of styrene and another vinyl monomer is preferable in terms of developability and fixability.

  As a comonomer for the styrene monomer of the styrenic copolymer, acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, Monocarboxylic acid having a double bond such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide or a substituted product thereof; maleic acid, butyl maleate, methyl maleate, Dicarboxylic acids having a double bond such as dimethyl maleate and substituted products thereof; vinyl esters such as vinyl chloride, vinyl acetate and vinyl benzoate; ethylene-based olefins such as ethylene, propylene and butylene Vinyl methyl ketone, vinyl ketones such as vinyl hexyl ketone, vinyl methyl ether, vinyl ethyl ether, vinyl ethers such as vinyl isobutyl ether. These vinyl monomers are used alone or in combination of two or more.

  The styrenic copolymer is preferably crosslinked with a crosslinking agent in order to widen the fixing temperature range of the toner and improve the offset resistance. As the crosslinking agent, a compound having two or more polymerizable double bonds is used. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol dimethacrylate; divinylaniline; And divinyl ether, divinyl sulfide, divinyl sulfone and other divinyl compounds; and compounds having three or more vinyl groups. These are used alone or as a mixture.

  The toner particles of the present invention can be produced by a known production method such as a pulverization method or a polymerization method. For example, a kneading and pulverizing method in which a binder resin, a pigment, and a release agent are mixed and kneaded, pulverized, and classified to obtain toner particles; a binder resin, a pigment, and a release agent are dissolved or dispersed and mixed in an organic solvent. Dissolving suspension method in which particles are granulated in an aqueous medium and then solvent is removed to obtain toner particles; fine particles of a binder resin, a pigment, and a release agent are finely dispersed in an aqueous medium to obtain a toner particle size. Emulsion aggregation method to obtain toner particles by agglomeration: A polymerizable monomer, a pigment, and a release agent are dissolved or dispersed and mixed, granulated in an aqueous medium, and then the polymerizable monomer is polymerized with a polymerization initiator. And suspension polymerization to obtain toner particles. Among them, the toner particles produced by the suspension polymerization method are preferable because they are close to true spheres and have less surface irregularities, so that the spherical particles and hydrotalcite particles of the present invention are easily diffused uniformly on the toner particles.

  Examples of the colorant that can be used in the toner of the present invention include known colorants such as various conventionally known dyes and pigments.

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

  Examples of the color pigment for cyan include C.I. I. Pigment Blue 15, 15: 1, 15: 3 or a copper phthalocyanine pigment in which 1 to 5 phthalimidomethyl groups are substituted on the phthalocyanine skeleton.

  Examples of the color pigment for yellow include C.I. I. Pigment yellow 1, 3, 12, 13, 14, 17, 55, 74, 83, 93, 94, 95, 97, 98, 109, 110, 154, 155, 166, 180, 185.

  As the black colorant, carbon black, aniline black, acetylene black, titanium black, and those which are toned in black using the yellow / magenta / cyan colorant shown above can be used.

The toner of the present invention can also be used as a magnetic toner, and in this case, the following magnetic materials are used. Iron oxide including magnetite, maghemite, ferrite, or other metal oxides; metals such as Fe, Co, Ni, or these metals and Al, Co, Cu, Pb, Mg, Ni, Sn, Alloys with metals such as Zn, Sb, Ca, Mn, Se, Ti, and mixtures thereof. More specifically, iron trioxide (Fe ₃ O ₄ ), iron sesquioxide (γ-Fe ₂ O ₃ ), iron oxide zinc (ZnFe ₂ O ₄ ), copper iron oxide (CuFe ₂ O ₄ ), oxidation Examples thereof include iron neodymium (NdFe ₂ O ₃ ), iron barium oxide (BaFe ₁₂ O ₁₉ ), iron magnesium oxide (MgFe ₂ O ₄ ), and iron manganese oxide (MnFe ₂ O ₄ ). The magnetic materials described above are used alone or in combination of two or more. A particularly suitable magnetic material is a fine powder of triiron tetroxide or γ-iron sesquioxide.

These magnetic materials preferably have an average particle size of 0.1 μm to 2 μm, and more preferably 0.1 μm to 0.3 μm. The magnetic characteristics when 795.8 kA / m (10 k Oersted) is applied are such that the coercive force (Hc) is 1.6 kA / m to 12 kA / m (20 Oersted to 150 Oersted) and the saturation magnetization (σs) is 5 Am ² / kg or more and 200 Am ² / kg or less, preferably 50 Am ² / kg or more and 100 Am ² / kg or less. Residual magnetization (.sigma.r) is, 2Am ² / kg or more 20 Am ² / kg or less being preferred.

  The magnetic body is preferably used in the range of 10 to 200 parts by mass, more preferably 20 to 150 parts by mass, with respect to 100 parts by mass of the binder resin.

  The toner of the present invention may contain a release agent. The release agent includes aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax and paraffin wax; oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax; aliphatic hydrocarbon waxes Block copolymers of these: waxes based on fatty acid esters such as carnauba wax, sazol wax, and montanic acid ester wax; and fatty acid esters such as deoxidized carnauba wax that are partially or fully deoxidized, behenic acid Examples thereof include partially esterified products of fatty acids such as monoglycerides and polyhydric alcohols; methyl ester compounds having a hydroxyl group obtained by hydrogenating vegetable oils and fats.

  As for the molecular weight distribution of the release agent, the main peak is preferably in a region having a molecular weight of 400 or more and 2400 or less, and more preferably in a region of 430 or more and 2000 or less. Thereby, preferable thermal characteristics can be imparted to the toner. The amount of the release agent added is preferably 2.5 parts by mass or more and 40.0 parts by mass or less, and 3.0 parts by mass or more and 15.0 parts by mass or less with respect to 100 parts by mass of the binder resin. More preferably.

  In the toner of the present invention, it is preferable to use a charge control agent in order to keep the toner chargeability stable. The following substances are used for controlling the toner to be negatively charged.

  For example, organometallic compounds and chelate compounds are effective, and there are monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acids, and dicarboxylic acid-based metal compounds. Other examples include aromatic oxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol.

  Furthermore, urea derivatives, metal-containing salicylic acid compounds, metal-containing naphthoic acid compounds, boron compounds, quaternary ammonium salts, calixarene, resin charge control agents, and the like can be given.

  The following substances are used to control the toner to be positively charged.

  Nigrosine-modified products of nigrosine and fatty acid metal salts, etc .; guanidine compounds; imidazole compounds; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and the like Phosphonium salts and other onium salts and their lake pigments; triphenylmethane dyes and their lake pigments (as rake agents, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid Acid, ferricyanide, ferrocyanide, etc.); metal salt of higher fatty acid; diorganotin oxide such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; DOO, dioctyl tin borate, such as diorganotin tin borate such dicyclohexyl tin borate; resin charge control agent and the like. These can be used alone or in combination of two or more.

  In the present invention, the triboelectric row of toner particles needs to be on the negative polarity side of the hydrotalcite particles and toner particles. Since the hydrotalcite particles exhibit a strong positive chargeability, the toner particles are preferably negatively charged in order to satisfy the above relationship.

  In addition, the stronger the negative chargeability of the toner, the higher the electrostatic adhesion between the toner particles and the hydrotalcite particles. In order to increase the negative chargeability of the toner particles while having high environmental stability, it is preferable to use the polymer A having the structure a represented by the following formula (2) as a charge control agent.

（式中、Ｒ¹は、炭素数１以上１８以下のアルキル基、または、炭素数１以上１８以下のアルコキシ基を表し、Ｒ²は、水素原子、ヒドロキシ基、炭素数１以上１８以下のアルキル基、または、炭素数１以上１８以下のアルコキシ基を表し、ｇは１以上３以下の整数を表し、ｈは０以上３以下の整数を表し、ｈが２または３の場合、Ｒ¹はそれぞれ独立して選択でき、＊は重合体Ａにおける結合部位である。）

(In the formula, R ¹ represents an alkyl group having 1 to 18 carbon atoms or an alkoxy group having 1 to 18 carbon atoms, and R ² represents a hydrogen atom, a hydroxy group, or an alkyl group having 1 to 18 carbon atoms. Group represents an alkoxy group having 1 to 18 carbon atoms, g represents an integer of 1 to 3, h represents an integer of 0 to 3, and when h is 2 or 3, R ¹ represents And can be selected independently, * is the binding site in polymer A)

  The main chain structure of the polymer A is not particularly limited as long as the structure a can be linked at the * part. Examples thereof include vinyl polymers, polyester polymers, polyamide polymers, polyurethane polymers, polyether polymers, and the like. Moreover, the hybrid type polymer which combined these 2 or more types is also mentioned. Among these, a polyester polymer or a vinyl polymer is preferable in consideration of manufacturability, cost merit, and affinity with a binder resin. More preferably, it is a vinyl polymer having the structure a as a partial structure represented by the following formula (3).

（式中、Ｒ³は、ヒドロキシ基、カルボキシ基、炭素数１以上１８以下のアルキル基、または、炭素数１以上１８以下のアルコキシ基を表し、Ｒ⁴は、水素原子、ヒドロキシ基、炭素数１以上１８以下のアルキル基、または、炭素数１以上１８以下のアルコキシ基を表し、Ｒ⁵は、水素原子またはメチル基を表し、ｉは１以上３以下の整数を表し、ｊは０以上３以下の整数を表し、ｊが２または３の場合、Ｒ³はそれぞれ独立して選択できる。）

(Wherein R ³ represents a hydroxy group, a carboxy group, an alkyl group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 18 carbon atoms, and R ⁴ represents a hydrogen atom, a hydroxy group, or a carbon number. Represents an alkyl group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 18 carbon atoms, R ⁵ represents a hydrogen atom or a methyl group, i represents an integer of 1 to 3 and j represents 0 to 3; Represents the following integer, and when j is 2 or 3, each R ³ can be independently selected.)

Examples of the alkyl group in R ³ and R ⁴ include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group and the like, and alkoxy group Examples of these include methoxy group, ethoxy group, propoxy group and the like. Thus, since the polymer A is a vinyl polymer, it is easily compatible in the toner particles containing the vinyl resin as a main component. Compatibilization makes it possible to take a more optimal molecular arrangement, and the charging ability of the polymer A is more effectively exhibited. When the toner is produced in an aqueous medium, the effect is further enhanced, and the arrangement of the highly polar polymer A component on the toner particle surface layer proceeds smoothly, so that the particle size distribution is improved.

  As for the molecular weight of the polymer A, the weight average molecular weight calculated by gel permeation chromatography (GPC) is 1,000 or more and 100,000 or less. By setting the weight average molecular weight of the polymer A to 1000 or more, exudation under high temperature and high humidity is suppressed, and good fluidity can be secured. Further, when the weight average molecular weight is 100,000 or less, the toner has good fixability and can suppress uneven distribution among toner particles, resulting in a sharp charge amount distribution. In order to make a weight average molecular weight into the said range, it can control by changing conditions, such as the amount of reagents at the time of manufacturing the polymer A, reaction temperature, and solvent concentration. Moreover, the polymer A of desired molecular weight can be obtained by fractionating by GPC.

  Further, the content of the structure a in the polymer A is preferably 10 μmol / g or more and 1500 μmol / g or less. When the content of the structure a in the polymer A is 10 μmol / g or more, good triboelectric chargeability is exhibited. Moreover, since it is 1500 micromol / g or less, the influence of the hygroscopic property which the structure a has can be suppressed smaller, and favorable fluidity | liquidity is exhibited. The content of the structure “a” in the polymer A can be adjusted by the charging ratio at the time of synthesizing the polymer A and the reaction conditions such as the reaction temperature.

  It does not specifically limit as a manufacturing method of the polymer A, It can manufacture by a well-known method. In the case of a vinyl polymer, for example, a polymerizable monomer (formula (4)) containing a structure a having a structure represented by formula (2) and a vinyl monomer are polymerized as an example. This is a method of copolymerization using an initiator.

（式中、Ｒ⁹は、炭素数１以上１８以下のアルキル基、または、炭素数１以上１８以下のアルコキシ基を表し、Ｒ¹⁰は、水素原子、ヒドロキシ基、炭素数１以上１８以下のアルキル基、または、炭素数１以上１８以下のアルコキシ基を表し、ｍは１以上３以下の整数を表し、ｎは０以上３以下の整数を表し、ｎが２または３の場合、Ｒ⁹はそれぞれ独立して選択できる。）

(In the formula, R ⁹ represents an alkyl group having 1 to 18 carbon atoms or an alkoxy group having 1 to 18 carbon atoms, and R ¹⁰ represents a hydrogen atom, a hydroxy group, or an alkyl group having 1 to 18 carbon atoms. A group or an alkoxy group having 1 to 18 carbon atoms, m represents an integer of 1 to 3, n represents an integer of 0 to 3, and when n is 2 or 3, R ⁹ is Can be selected independently.)

  Specific examples of polymerizable monomers containing structure a are shown in Table 1.

  Moreover, it does not restrict | limit especially as a vinyl-type monomer copolymerized with the polymerizable monomer A containing the structure a. Specifically, styrene and its derivatives such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene; ethylene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; Vinyl halides such as vinyl, vinylidene chloride, vinyl bromide, vinyl fluoride; vinyl ester acids such as vinyl acetate, vinyl propionate, vinyl benzoate; acrylic acid-n-butyl, acrylic acid-2-ethylhexyl, etc. Acrylic acid esters; Methacrylic acid esters obtained by changing the acrylic acid of the acrylic acid esters to methacrylic acid; Methacrylic acid amino esters such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate; Vinyl methyl ether, vinyl ethyl ether Vinyl ethers; vinyl ketones such as vinyl methyl ketone; N-vinyl compounds such as N-vinyl pyrrole; vinyl naphthalenes; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, acrylamide, acrylic acid, methacrylic acid, etc. Can be mentioned. In addition, you may use a vinyl monomer in combination of 2 or more type as needed.

  As a polymerization initiator that can be used when copolymerizing the polymerizable monomer component described above, various substances such as a peroxide polymerization initiator and an azo polymerization initiator can be used. Examples of the peroxide polymerization initiator that can be used include peroxyesters, peroxydicarbonates, dialkyl peroxides, peroxyketals, ketone peroxides, hydroperoxides, and diacyl peroxides. Examples of the inorganic system include persulfate and hydrogen peroxide. Specifically, t-butyl peroxyacetate, t-butyl peroxypivalate, t-butyl peroxyisobutyrate, t-hexyl peroxyacetate, t-hexyl peroxypivalate, t-hexyl peroxyiso Peroxyesters such as butyrate, t-butylperoxyisopropyl monocarbonate, t-butylperoxy 2-ethylhexyl monocarbonate; diacyl peroxides such as benzoyl peroxide; peroxydicarbonates such as diisopropyl peroxydicarbonate; 1 , 1-di-t-hexylperoxycyclohexane and other peroxyketals; di-t-butyl peroxide and other dialkyl peroxides; and other examples include t-butyl peroxyallyl monocarbonate and the like. It is. Examples of the azo polymerization initiator that can be used include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane- 1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile, dimethyl-2,2′-azobis (2-methylpropionate), etc. Illustrated.

  If necessary, two or more of these polymerization initiators can be used simultaneously. It is preferable that the usage-amount of the polymerization initiator used in this case is 0.100 mass part or more and 20.0 mass parts or less with respect to 100 mass parts of polymerizable monomers. As the polymerization method, any method such as solution polymerization, suspension polymerization, emulsion polymerization, dispersion polymerization, precipitation polymerization, bulk polymerization and the like can be used, and it is not particularly limited.

  The weight average particle diameter (D4) of the toner of the present invention is preferably 3.0 μm or more and 15.0 μm or less, more preferably 4.0 μm or more and 12.0 μm or less. The average circularity of the toner is preferably 0.960 or more and 0.995 or less. If it is 0.960 or more, the spherical particles and the hydrotalcite particles are easily diffused on the toner particles, the aggregated particles are not formed at the convex portions, and as a result, the separation of the hydrotalcite particles hardly occurs. If it is 0.995 or less, cleaning deterioration of transfer residual toner remaining on the photosensitive member or the intermediate transfer member does not occur.

  The toner of the present invention can be used in any developing system as a one-component or two-component developer. For example, in the case of a magnetic toner in which a magnetic material is contained in the toner as the one-component developer, there is a method of transporting and charging the magnetic toner using a magnet built in the developing sleeve. In addition, when using a non-magnetic toner that does not contain a magnetic material, there is a method in which a blade or a fur brush is used to frictionally charge the toner to adhere it onto the developing roller.

  When used as a two-component developer, for example, the magnetic carrier to be mixed with the toner is composed of an element selected from iron, copper, zinc, nickel, cobalt, manganese, chromium and the like alone or in a composite ferrite state. The shape of the magnetic carrier used at this time may be spherical, flat, irregular, or the like, and a magnetic carrier whose surface state fine structure (for example, surface irregularity) is appropriately controlled may be used. it can. A resin-coated carrier whose surface is coated with a resin can also be suitably used. The average particle size of the carrier used is preferably 10 μm or more and 100 μm or less, more preferably 20 μm or more and 50 μm or less. Further, when the two-component developer is prepared by mixing these carrier and toner, the toner concentration in the developer is preferably about 2% by mass or more and 15% by mass or less.

  The toner of the present invention can be used in a conventionally known image forming apparatus without particular limitation. Among them, a charging step for charging the photosensitive member, an exposure step for exposing the charged photosensitive member to form an electrostatic latent image, and a developing step for developing the electrostatic latent image with toner to form a toner image. And a transfer step of transferring the toner image onto a transfer material and a cleaning step of removing residual toner remaining on the surface of the photoconductor after transfer. Furthermore, the toner of the present invention is disposed so as to form a contact portion with the toner carrier that carries the toner and develops the electrostatic latent image, and supplies the toner to the toner carrier. An image forming apparatus having a developing chamber having a supply member and a storage portion in which the toner is stored, wherein the rotation direction of the toner carrier and the supply member is the same in each contact surface It is more preferable to use it in an image forming apparatus that is in the direction of moving to the right. By using the toner of the present invention in the image forming apparatus having the above-described configuration, it becomes possible to exhibit stable performance over a longer period.

  The image forming apparatus having the above configuration that can be used in the present invention will be described below. First, the overall configuration of the image forming apparatus will be described.

  FIG. 1 is a schematic sectional view of the image forming apparatus 100. The image forming apparatus 100 is a full-color laser printer that employs an inline method and an intermediate transfer method. The image forming apparatus 100 can form a full-color image on a recording material (for example, recording paper, plastic sheet, cloth, etc.) according to the image information. The image information is input to the image forming apparatus main body 100A from an image reading apparatus connected to the image forming apparatus main body 100A or a host device such as a personal computer connected to the image forming apparatus main body 100A in a communicable manner.

  The image forming apparatus 100 includes, as a plurality of image forming units, first, second, and third images for forming yellow (Y), magenta (M), cyan (C), and black (K) images, respectively. And fourth image forming units SY, SM, SC, and SK.

  The configurations and operations of the first to fourth image forming units SY, SM, SC, and SK are substantially the same except that the colors of the images to be formed are different. Therefore, in the following, unless there is a particular distinction, the subscripts Y, M, C, and K given to the reference numerals to indicate that they are elements provided for any color are omitted, and generally explain.

  The image forming apparatus 100 includes, as a plurality of image carriers, four drum-type electrophotographic photoreceptors, that is, the photoreceptor drums 1 arranged in parallel in a direction intersecting the vertical direction. The photosensitive drum 1 is rotationally driven by a driving means (drive source) (not shown) in the direction indicated by an arrow A (clockwise). Around the photosensitive drum 1, a charging roller 2 as a charging means for uniformly charging the surface of the photosensitive drum 1, a laser is irradiated based on image information, and an electrostatic image (electrostatic) is formed on the photosensitive drum 1. A scanner unit (exposure device) 3 is disposed as exposure means for forming a (latent image). Further, around the photosensitive drum 1, a developing unit (developing device) 4 as developing means for developing an electrostatic image as a toner image, toner remaining on the surface of the photosensitive drum 1 after transfer (transfer residual toner) A cleaning member 6 is disposed as a cleaning means for removing water. Further, an intermediate transfer belt 5 as an intermediate transfer body for transferring the toner image on the photosensitive drum 1 to the recording material 12 is disposed opposite to the four photosensitive drums 1.

  The developing unit 4 uses the toner of the present invention as a developer. The developing unit 4 performs reverse development by bringing a developing roller (described later) as a toner carrier into contact with the photosensitive drum 1. That is, the developing unit 4 is a portion (image portion, exposure portion) in which the charge is attenuated by exposure on the photosensitive drum 1 with toner charged to the same polarity (negative polarity in this embodiment) as the charging polarity of the photosensitive drum 1. ) To develop the electrostatic image.

  The intermediate transfer belt 5 formed of an endless belt as an intermediate transfer member abuts on all the photosensitive drums 1 and circulates (rotates) in the direction of arrow B (counterclockwise) in the figure. The intermediate transfer belt 5 is wound around a driving roller 51, a secondary transfer counter roller 52, and a driven roller 53 as a plurality of support members.

  On the inner peripheral surface side of the intermediate transfer belt 5, four primary transfer rollers 8 as primary transfer means are arranged in parallel so as to face the respective photosensitive drums 1. The primary transfer roller 8 presses the intermediate transfer belt 5 toward the photosensitive drum 1 to form a primary transfer portion N1 where the intermediate transfer belt 5 and the photosensitive drum 1 abut. A bias having a polarity opposite to the normal charging polarity of the toner is applied to the primary transfer roller 8 from a primary transfer bias power source (high voltage power source) as a primary transfer bias applying unit (not shown). As a result, the toner image on the photosensitive drum 1 is transferred (primary transfer) onto the intermediate transfer belt 5.

  In addition, a secondary transfer roller 9 as a secondary transfer unit is disposed at a position facing the secondary transfer counter roller 52 on the outer peripheral surface side of the intermediate transfer belt 5. The secondary transfer roller 9 is pressed against the secondary transfer counter roller 52 via the intermediate transfer belt 5 to form a secondary transfer portion N2 where the intermediate transfer belt 5 and the secondary transfer roller 9 come into contact. A bias having a polarity opposite to the normal charging polarity of the toner is applied to the secondary transfer roller 9 from a secondary transfer bias power source (high voltage power source) as a secondary transfer bias applying unit (not shown). As a result, the toner image on the intermediate transfer belt 5 is transferred (secondary transfer) to the recording material 12.

  More specifically, at the time of image formation, first, the surface of the photosensitive drum 1 is uniformly charged by the charging roller 2. Next, the surface of the charged photosensitive drum 1 is scanned and exposed by laser light corresponding to the image information emitted from the scanner unit 3, and an electrostatic image according to the image information is formed on the photosensitive drum 1. Next, the electrostatic image formed on the photosensitive drum 1 is developed as a toner image by the developing unit 4. The toner image formed on the photosensitive drum 1 is transferred (primary transfer) onto the intermediate transfer belt 5 by the action of the primary transfer roller 8.

  For example, when forming a full-color image, the above-described process is sequentially performed in the first to fourth image forming units SY, SM, SC, and SK, and the toner images of the respective colors are next superimposed on the intermediate transfer belt 5. The primary transfer.

  Thereafter, the recording material 12 is conveyed to the secondary transfer portion N2 in synchronization with the movement of the intermediate transfer belt 5. The four color toner images on the intermediate transfer belt 5 are secondarily transferred onto the recording material 12 collectively by the action of the secondary transfer roller 9 that is in contact with the intermediate transfer belt 5 via the recording material 12.

  The recording material 12 onto which the toner image has been transferred is conveyed to a fixing device 10 as a fixing unit. The toner image is fixed on the recording material 12 by applying heat and pressure to the recording material 12 in the fixing device 10.

  Further, the primary transfer residual toner remaining on the photosensitive drum 1 after the primary transfer process is removed and collected by the cleaning member 6. The secondary transfer residual toner remaining on the intermediate transfer belt 5 after the secondary transfer process is cleaned by the intermediate transfer belt cleaning device 11.

  Note that the image forming apparatus 100 can form a single-color or multi-color image using only one desired image forming unit or using only some (not all) image forming units. It is like that.

[Process cartridge configuration]
Next, the overall configuration of the process cartridge 7 attached to the image forming apparatus 100 will be described. The configuration and operation of the process cartridge 7 for each color are substantially the same except for the type (color) of the toner contained therein.

  FIG. 2 is a schematic cross-sectional view (main cross-sectional view) of the process cartridge 7 as viewed along the longitudinal direction (rotational axis direction) of the photosensitive drum 1. The posture of the process cartridge 7 in FIG. 2 is a posture in a state where the process cartridge 7 is mounted on the image forming apparatus main body. When the positional relationship and direction of each member of the process cartridge are described below, the positional relationship and direction in this posture are described below. Etc.

  The process cartridge 7 is configured by integrating a photosensitive unit 13 including the photosensitive drum 1 and the developing unit 4 including a developing roller 17 and the like.

  The photoconductor unit 13 has a cleaning frame 14 as a frame that supports various elements in the photoconductor unit 13. The photosensitive drum 1 is rotatably attached to the cleaning frame 14 via a bearing (not shown). The photosensitive drum 1 is rotationally driven in the direction of the arrow A (clockwise) in accordance with the image forming operation by transmitting the driving force of a driving motor (not shown) as a driving means (driving source) to the photosensitive unit 13. Is done.

  Further, the cleaning unit 6 and the charging roller 2 are disposed in the photosensitive unit 13 so as to come into contact with the peripheral surface of the photosensitive drum 1. The transfer residual toner removed from the surface of the photosensitive drum 1 by the cleaning member 6 falls and is stored in the cleaning frame 14.

  The charging roller 2 as charging means is driven to rotate by bringing the roller portion of conductive rubber into pressure contact with the photosensitive drum 1.

  Here, as a charging process, a predetermined DC voltage is applied to the core of the charging roller 2 with respect to the photosensitive drum 1, whereby a uniform dark portion potential (Vd) is applied to the surface of the photosensitive drum 1. Is formed. The spot pattern of the laser beam emitted in accordance with the image data by the laser beam from the scanner unit 3 described above exposes the photosensitive drum 1, and the exposed portion is charged on the surface by the carrier from the carrier generation layer. Disappears and the potential drops. As a result, an electrostatic latent image is formed on the photosensitive drum 1 with a predetermined light portion potential (Vl) at an exposed portion and a predetermined dark portion potential (Vd) at an unexposed portion.

  On the other hand, the developing unit 4 has a developing roller 17 as a toner carrier for carrying toner 80 and a developing chamber in which a toner supply roller 20 as a supply member for supplying toner to the developing roller 17 is disposed. ing. Further, the developing unit 4 includes a toner storage chamber 18.

  Further, the toner supply roller 20 rotates with a contact portion N formed between the toner supply roller 20 and the developing roller 17.

  A stirring and conveying member 22 is provided in the toner storage chamber 18. The agitating / conveying member 22 agitates the toner accommodated in the toner accommodating chamber 18 and also conveys the toner toward the upper portion of the toner supply roller 20 in the direction of arrow G in the figure.

  The developing blade 21 is disposed below the developing roller 17 and is in contact with the developing roller at a counter, and regulates the coating amount of toner supplied by the toner supply roller 20 and applies a charge.

  The developing roller 17 and the photosensitive drum 1 rotate so that their surfaces move in the same direction at the facing portion.

  The toner supply roller 20 and the developing roller rotate in a direction in which their surfaces move from the upper end to the lower end of the contact portion N. That is, the toner supply roller 20 rotates in the direction of the arrow E (clockwise) and the developing roller 17 rotates in the direction of arrow D. The toner supply roller 20 is an elastic sponge roller in which a foam layer is formed on the outer periphery of a conductive metal core. The toner supply roller 20 and the developing roller 17 are in contact with each other with a predetermined intrusion amount. The toner supply roller 20 and the developing roller 17 are rotated with a peripheral speed difference in the same direction at the contact portion N. With this operation, the toner supply roller 20 supplies toner to the developing roller 17. Yes. At this time, the toner supply amount to the developing roller can be adjusted by adjusting the potential difference between the toner supply roller and the developing roller.

  The measurement method used in the present invention is described below.

<Measurement method of triboelectric charge train of toner particles, spherical particles and hydrotalcite particles>
The triboelectric charge train of toner particles, spherical particles and hydrotalcite particles was determined by measuring zero point charge using a standard carrier. The standard carrier is a carrier defined by a measuring method based on “Toner Charge Measurement Method Standards (Journal of Imaging Society of Japan 37, 461 (1998))” established by the Japan Imaging Society Technical Committee. Using four types of standard carriers (N-01, N-02, P-01, P-02), the charge amount of each of the toner particles, spherical particles, and hydrotalcite particles was measured using a blow-off method. The charge amount test values of the standard carriers were −34.3, −20.8, 23.9, and 38.4 μC / g in the order of N-01, N-02, P-01, and P-02, respectively.

  The humidity was measured at a temperature of 20 ° C. and a humidity of 50% according to the method described in the standard for measuring toner charge amount. As the mixing conditions, in the case of toner particles, 1 g of toner particles was used with respect to 19 g of a standard carrier. In the case of spherical particles and hydrotalcite particles, 0.2 g of spherical particles and hydrotalcite particles were used with respect to 19.8 g of the standard carrier. As a shaker, an arm swing type shake mixer (YS-8D: Yayoi Co., Ltd.) was used and shaken for 3 minutes at a swing angle of 30 degrees and a shake speed of 150 times / minute. A wire mesh of 20 μm (635 mesh) was used, and suction was performed for 20 seconds with a suction pressure of 2 kPa.

The method for deriving the zero point charge is described below. The charge amount of each particle when each standard carrier is used is plotted against the charge amount test value of each standard carrier and is connected by a straight line. The value of the charge amount test value when the charge amount of each particle becomes zero was defined as zero point charge. The larger the zero point charge value, the stronger the negative polarity. In the present invention, toner particles, spherical particles, and hydrotalcite particles are in order from the one with the highest zero point charge value (that is, negative polarity).

<Measurement method of the fixing rate of hydrotalcite particles>
A toner containing hydrotalcite particles is dispersed in a solution using a water washing method, centrifuged, and the amount of the hydrotalcite particles in the toner before and after the water washing is measured. The residual amount in the inside is calculated and used as the fixing rate.

The amount of the hydrotalcite particles is determined by calculation from the strength of the metal element derived from the hydrotalcite particles in the toner measured with a fluorescent X-ray analyzer (XRF). The fixing rate [A] is obtained from the following formula (5).
Formula (5) Adhesion rate [A] = {1- (P1-P2) / P1} × 100
[In the formula, P1 is the amount of metal element derived from hydrotalcite particles in the initial toner “mass%”, and P2 is the amount of metal element derived from hydrotalcite particles in the toner after water washing by XRF measurement “mass%”. is there. In this example, the content of the hydrotalcite particles in the toner was calculated from the Mg element strength using a separately prepared calibration curve. ]

<Details of measuring method of sticking rate>
(1) Add 160 g of special grade sucrose powder to 100 ml of RO water and dissolve it with a hot water bath to prepare a sucrose solution.
(2) Precise measurement of pH 7 consisting of 24 ml of sucrose solution prepared in (1) in a 50 ml centrifuge tube and “Contaminone N” (nonionic surfactant, anionic surfactant, organic builder as a dispersant) 6m of a 10% by weight aqueous solution of a neutral detergent for washing equipment, manufactured by Wako Pure Chemical Industries, Ltd.)
After 1 l, about 1 g of toner is introduced.
(3) The tube produced in (2) above is set on a shaker and shaken under the conditions of a shaking number of 6 s ⁻¹ and a shaking time of 20 minutes.
(4) The shaken solution prepared in (3) above is placed in a glass tube for a 50 ml swing rotor, and the centrifuge is centrifuged at a rotation speed of 58 s ⁻¹ and a rotation time of 30 minutes to obtain a toner and a solution. And separating hydrotalcite particles.
(5) Since the toner is separated into the uppermost layer, the solution is separated into the middle layer, and the hydrotalcite particles are separated into the lowermost layer, the uppermost layer toner is collected.
(6) The toner collected in (5) above is filtered with a vacuum filter and then dried with a dryer for 1 hour or more.
(7) The amount of metal element derived from hydrotalcite particles in the toner dried in the above (6) (Mg element in this embodiment) and the amount of metal element in the initial toner are measured by a fluorescent X-ray measurement apparatus (XRF). Measure with

<Method for measuring the number average particle diameter (D1) of spherical particles and hydrotalcite particles>
The number average particle diameter (D1) of the spherical particles and hydrotalcite particles in the present invention is measured as follows. 1 part by weight of spherical particles and hydrotalcite particles are added to 100 parts by weight of toner particles, and a photograph of the toner particle surface is taken at a magnification of 100,000 times by FE-SEM S-4800 (manufactured by Hitachi, Ltd.). . Using the enlarged photograph, the particle diameters of 100 or more spherical particles and hydrotalcite particles are measured, and the number average diameter (D1) of the spherical particles and hydrotalcite particles is determined from the arithmetic average. The particle diameter is counted as the particle diameter when the shape is spherical, and when the shape has a major axis and a minor axis, the major axis is counted.

<Method for measuring roundness of spherical particles>
The roundness of the spherical particles was measured using a toner surface observation image taken with a Hitachi ultra-high resolution field emission scanning electron microscope S-4800 (Hitachi High-Technologies Corporation), image analysis software image processing software ImageJ (development). It is calculated by analyzing using the original Wayne Rand. The measurement procedure is shown below.

(1) Sample preparation A conductive paste is thinly applied to a sample table (aluminum sample table 15 mm × 6 mm), and toner is adhered thereon. Using a blower, the excess toner is air blown and then dried sufficiently. Set the sample stage on the sample holder.

(2) S-4800 Observation Conditions Observation conditions are shown below.
Acceleration voltage: 0.8 kV
Emission current: 20μA
Detector: [on SE (U)], [+ BSE (LA.100)]
Probe current: [Normal]
Focus mode: [UHR]
WD: [3.0mm]

(3) Image storage Brightness adjustment is performed in the ABC mode, and a photograph is taken with a size of 640 × 480 pixels and stored. The following analysis is performed using this image file. At this time, a relatively flat portion of the toner surface (a visual field in which the entire observation surface is in focus) is selected to obtain an image. The observation magnification is appropriately adjusted according to the size of the observation target fine particles.

(4) Image Analysis From the obtained SEM observation image, roundness is calculated using image processing software ImageJ (developer Wayne Randhand). The calculation procedure is shown below.
[1] A scale is set by [Analyze]-[Set Scale].
[2] A threshold is set by [Image]-[Adjust]-[Threshold].
(Set to a value that does not leave noise and leaves the inorganic fine particles to be measured)
[3] In [Image]-[Crop], the measured image portion of the inorganic fine particles is selected.
[4] The overlapping particles are erased by image editing.
[5] Invert the monochrome image with [Edit]-[Invert].
[6] [Analyze]-[Set Measurements]-[Area]
Check [Shape Descriptors]. Also,
Set [Redirect to] to [None],
[Decimal Place (0-9)] is set to 3.
[7] In [Analyze]-[Analyze Particle], specify the area of the particle to be 0.0005 μm 2 or more, and execute.
[8] Obtain the circularity value of each particle.
[9] Measurement is performed on 100 or more particles observed, and an arithmetic average value of the obtained roundness is calculated to obtain roundness.

  This measurement can be performed in the same manner for a toner in which a plurality of types of fine particles are contained on the toner particle surface. When the reflected electron image is observed in S-4800, the element of each fine particle can be specified using elemental analysis such as EDAX. Further, it is possible to select the same kind of fine particles from the shape characteristics and the like. By performing the above measurement on the same kind of fine particles, the roundness for each kind of fine particles can be calculated. Similarly, the number average particle diameter (D1) can be calculated for each kind of fine particles.

<Method for Measuring Toner Weight Average Particle Size (D4)>
The weight average particle diameter (D4) of the toner is calculated as follows. As a measuring device, a precise particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) using a pore electrical resistance method equipped with a 100 μm aperture tube is used. For setting the measurement conditions and analyzing the measurement data, the attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) is used. The measurement is performed with 25,000 effective measurement channels. As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

  Prior to measurement and analysis, the dedicated software was set as follows. On the “Change Standard Measurement Method (SOM)” screen of the dedicated software, set the total count in the control mode to 50,000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter Set the value obtained using By pressing the “Threshold / Noise Level Measurement Button”, the threshold and noise level are automatically set. In addition, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the “aperture tube flush after measurement” is checked. In the “Pulse to particle size conversion setting” screen of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set to 2 μm to 60 μm.

The specific measurement method is as follows.
(1) About 200 ml of the electrolytic solution is placed in a glass 250 ml round bottom beaker exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rpm. Then, the dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the dedicated software.
(2) About 30 ml of the electrolytic aqueous solution is put into a glass 100 ml flat bottom beaker. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. About 0.3 ml of a diluted solution obtained by diluting 3) with ion-exchanged water is added.
(3) Two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dissipation System Tetora 150” (manufactured by Nikki Bios Co., Ltd.) having an electrical output of 120 W is prepared. About 3.3 l of ion-exchanged water is placed in the water tank of the ultrasonic disperser, and about 2 ml of Contaminone N is added to the water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. And the height position of a beaker is adjusted so that the resonance state of the liquid level of the electrolyte solution in a beaker may become the maximum.
(5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, about 10 mg of toner is added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.
(6) To the round bottom beaker of (1) installed in the sample stand, the electrolyte solution of (5) in which the toner is dispersed is dropped using a pipette, and the measurement concentration is adjusted to about 5%. . Measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) is calculated. The “average diameter” on the “analysis / volume statistics (arithmetic average)” screen when the graph / volume% is set by the dedicated software is the weight average particle diameter (D4).

<Measuring method of average circularity of toner>
The circularity of the toner in the present invention is measured using a flow type particle image measuring device “FPIA-3000” (manufactured by Sysmex Corporation) under the measurement / analysis conditions during calibration.

  A specific measurement method is as follows. First, about 20 ml of ion-exchanged water from which impure solids are removed in advance is put in a glass container. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. About 0.2 ml of a diluted solution obtained by diluting the solution with ion exchange water about 3 times by mass. Further, about 0.02 g of a measurement sample is added, and dispersion treatment is performed for 2 minutes using an ultrasonic disperser to obtain a dispersion for measurement. In that case, it cools suitably so that the temperature of a dispersion liquid may become 10 to 40 degreeC. As the ultrasonic disperser, a desktop type ultrasonic cleaner disperser (for example, “VS-150” (manufactured by VervoCrea)) having an oscillation frequency of 50 kHz and an electric output of 150 W is used. Ion exchange water is added, and about 2 ml of the above-mentioned Contaminone N is added to this water tank.

  For the measurement, the flow type particle image analyzer equipped with “UPlanApro” (magnification: 10 ×, numerical aperture: 0.40) as an objective lens is used. It was used. The dispersion prepared in accordance with the above procedure is introduced into the flow type particle image analyzer, and 3000 toner particles are measured in the HPF measurement mode and in the total count mode. Then, the binarization threshold at the time of particle analysis is set to 85%, the analysis particle diameter is limited to the equivalent circle diameter of 1.985 μm or more and less than 39.69 μm, and the average circularity is obtained.

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

  In this embodiment, a flow type particle image analyzer that has been issued a calibration certificate issued by Sysmex Corporation was used. Measurement was performed under the measurement and analysis conditions when the calibration certificate was received, except that the analysis particle size was limited to a circle equivalent diameter of 1.985 μm or more and less than 39.69 μm.

  Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to the following examples as long as the gist thereof is not exceeded.

  The toner production method will be described below.

[Preparation of Charge Control Resin 1]
<Synthesis of vinyl monomer>
(Process 1)
100 g of 2,5-dihydroxybenzoic acid and 1441 g of 80% sulfuric acid were heated and mixed at 50 ° C. To this dispersion, 144 g of tert-butyl alcohol was added and stirred at 50 ° C. for 30 minutes. Thereafter, 144 g of tert-butyl alcohol was added to this dispersion and stirring was performed for 30 minutes three times. The reaction solution was cooled to room temperature and poured slowly into 1 kg of ice water. The precipitate was filtered, washed with water, and then washed with hexane. This precipitate was dissolved in 200 mL of methanol and reprecipitated in 3.6 L of water. After filtration, it was dried at 80 ° C. to obtain 74.9 g of a salicylic acid intermediate represented by the following formula (6).

(Process 2)
25.0 g of the obtained salicylic acid intermediate was dissolved in 150 mL of methanol, 36.9 g of potassium carbonate was added, and the mixture was heated to 65 ° C. To this reaction solution, a mixed solution of 18.7 g of 4- (chloromethyl) styrene and 100 mL of methanol was added dropwise, and reacted at 65 ° C. for 3 hours. The reaction solution was cooled and then filtered, and the filtrate was concentrated to obtain a crude product. The crude product was dispersed in 1.5 L of water at pH = 2 and extracted by adding ethyl acetate. Thereafter, it was washed with water and dried over magnesium sulfate, and ethyl acetate was distilled off under reduced pressure to obtain a precipitate. The precipitate was washed with hexane and purified by recrystallization from toluene and ethyl acetate to obtain 20.1 g of vinyl monomer 1a (corresponding to M-3 in Table 1) represented by the following formula (7).

<Synthesis of Charge Control Resin 1>
9.91 g of vinyl monomer 1a represented by formula (7) and 60.1 g of styrene were dissolved in 42.0 ml of toluene, stirred for 1 hour, and then heated to 110 ° C. To this reaction solution, a mixed solution of 4.62 g of tert-butyl peroxyisopropyl monocarbonate (trade name: Perbutyl I, manufactured by NOF Corporation) and 42 ml of toluene was added dropwise. Furthermore, it reacted at 110 degreeC for 4 hours. Then, it cooled and it was dripped at methanol 1L, and the deposit was obtained. The obtained precipitate was dissolved in 120 ml of THF and then added dropwise to 1.80 L of methanol to precipitate a white precipitate, which was filtered and dried at 90 ° C. under reduced pressure to obtain 57.6 g of charge control resin 1. .

[Preparation of Toner Particles 1]
With respect to 100 parts by mass of the styrene monomer, C.I. I. 16.5 parts by mass of Pigment Blue 15: 3 and 3.0 parts by mass of an aluminum compound of di-tertiary butylsalicylic acid [Bontron E88 (manufactured by Orient Chemical Industries)] were prepared. These were introduced into an attritor (manufactured by Nihon Coke Kogyo Co., Ltd.) and stirred at 200 rpm at 25 ° C. for 180 minutes using zirconia beads having a radius of 1.25 mm (140 parts by mass) to prepare a master batch dispersion 1 did.

On the other hand, after adding 450 parts by mass of 0.1 M Na ₃ PO ₄ aqueous solution to 710 parts by mass of ion-exchanged water and heating to 60 ° C., 67.7 parts by mass of 1.0 M CaCl ₂ aqueous solution was gradually added. An aqueous medium containing a calcium phosphate compound was obtained.
Master batch dispersion 1 40 parts by mass Styrene monomer 28 parts by mass n-butyl acrylate monomer 18 parts by mass Hydrocarbon wax 9 parts by mass (Fischer-Tropsch wax, maximum endothermic peak = 78 ° C., Mw = 750)
Charge control resin 1 0.3 parts by mass Polyester resin 5 parts by mass (terephthalic acid: isophthalic acid: propylene oxide modified bisphenol A (2 mol adduct): ethylene oxide modified bisphenol A (2 mol adduct) = 30: 30 : 30:10 polycondensate, acid value 11, Tg = 74 ° C., Mw = 11,000, Mn = 4,000)
The material was warmed to 65 ° C. K. Using a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), it was uniformly dissolved and dispersed at 5,000 rpm. In this, 7.1 mass part of 70% toluene solution of polymerization initiator 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate was dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition was charged into the aqueous medium, and the temperature was 65 ° C. and N ₂ atmosphere. K. The mixture was stirred for 10 minutes at 10,000 rpm with a homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to granulate the polymerizable monomer composition. Thereafter, the temperature was raised to 67 ° C. while stirring with a paddle stirring blade. When the polymerization conversion rate of the polymerizable vinyl monomer reached 90%, a 0.1 mol / liter sodium hydroxide aqueous solution was added. The pH of the aqueous dispersion medium was adjusted to 9. Furthermore, it heated up at 80 degreeC with the temperature increase rate of 40 degreeC / h, and was made to react for 4 hours. After completion of the polymerization reaction, the residual monomer of the replenishing toner particles was distilled off under reduced pressure. After cooling the aqueous medium, hydrochloric acid was added to adjust the pH to 1.4, and the mixture was stirred for 6 hours to dissolve the calcium phosphate salt. The toner particles were separated by filtration and washed with water, and then dried at a temperature of 40 ° C. for 48 hours. The obtained dried product was classified and removed at the same time by a multi-division classifier (elbow jet classifier) manufactured by Nippon Steel Mining Co., Ltd., to obtain cyan toner particles 1. The physical properties of the toner particles 1 are shown in Table 2.

[Preparation of Toner Particles 2]
Toner particles 2 were obtained in the same manner except that the charge control resin 1 was not added in the toner particle 1 production step. Table 2 shows the physical properties of the toner particles 2 obtained.

[Preparation of Toner Particle 3]
Toner particles 3 were prepared in the same manner except that the addition amount of di-tertiary butyl salicylic acid aluminum compound [Bontron E88 (manufactured by Orient Chemical Co., Ltd.)] was changed to 0.5 parts by mass in the toner particle 2 production step. Obtained. Table 2 shows the physical properties of the toner particles 3 obtained.

[Production of Toner 1]
Toner particles 1 (100 parts by mass) and silica (0.2 parts by mass) having a number average particle diameter (D1) of 100 nm produced by the sol-gel method as spherical particles 1 are mixed with an FM mixer (Nippon Coke Industries, Ltd., FM10C). ) And mixed for 1 minute at 4000 rpm (first mixing step). Thereafter, hydrotalcite particles (DHT-4A, manufactured by Kyowa Chemical Co., Ltd.) (0.3 parts by mass) and hydrophobic silica fine particles (specific surface area 380 m ² / g by BET method, number average diameter of primary particles 7 nm, HMDS treatment, Nippon Aerosil Co., Ltd. (1.0 part by mass) was added and mixed at 4000 rpm for 10 minutes (second mixing step) to obtain toner 1. Table 4 shows the production conditions and physical properties of Toner 1.

  In addition, Table 3 shows the physical properties of the spherical particles 1 to 3, the comparative particles 1 to 3, and the hydrotalcite particles used in Examples and Comparative Examples.

[Preparation of Toners 2-3]
Toners 1 to 3 were obtained in the same manner except that the spherical particles 1 were changed to the spherical particles 2 to 3 shown in Table 3 in the production process of the toner 1.

[Preparation of Toner 4]
Toner particles 1 (100 parts by mass) and spherical particles 1 (0.2 parts by mass) were charged into an FM mixer (manufactured by Nippon Coke Industries, Ltd., FM10C) and mixed at 4000 rpm for 1 minute. Thereafter, the above-mentioned hydrophobic silica fine particles (1.0 part by mass) were added and mixed at 4000 rpm for 7 minutes. Thereafter, hydrotalcite particles (DHT-4A, manufactured by Kyowa Chemical Co., Ltd.) (0.3 parts by mass) were added and mixed at 4000 rpm for 3 minutes to obtain toner 4. Table 4 shows the physical properties of Toner 4.

[Preparation of Toner 5]
Toner particles 1 (100 parts by mass) and spherical particles 1 (0.2 parts by mass) were charged into Nobilta 130 (manufactured by Hosokawa Micron Corporation) and mixed for 1 minute at a power of 0.5 kW. Thereafter, hydrotalcite particles (DHT-4A, manufactured by Kyowa Chemical Co., Ltd.) (0.3 parts by mass) were added and mixed at 0.8 kW for 5 minutes. The obtained mixture and the above-mentioned hydrophobic silica fine particles (1.0 part by mass) were put into an FM mixer (manufactured by Nippon Coke Industries, Ltd., FM10C) and mixed at 4000 rpm for 10 minutes to obtain toner 5. . Table 4 shows the physical properties of Toner 5.

[Production of Toners 6 to 11]
Toners 6 to 11 were obtained in the same manner except that the types and addition amounts of toner particles, spherical particles and hydrotalcite particles were changed to the conditions shown in Table 4 in the production process of toner 1. Table 3 shows the physical properties of Toners 6-11.

[Production of Toners 12 to 13]
In the production process of the toner 1, the toner particle 1 was changed to the toner particle 2. Further, toners 12 to 13 were obtained in the same manner except that hydrotalcite particles or spherical particles 1 were not added. Table 4 shows the physical properties of Toners 12-13.

[Preparation of Toner 14]
Toner particles 2 (100 parts by mass) and spherical particles 1 (0.2 parts by mass) were put into an FM mixer (manufactured by Nippon Coke Industries, Ltd., FM10C) and mixed at 4000 rpm for 1 minute. Thereafter, the above-mentioned hydrophobic silica fine particles (1.0 part by mass) were added and mixed at 4000 rpm for 10 minutes. Thereafter, hydrotalcite particles (DHT-4A, manufactured by Kyowa Chemical Co., Ltd.) (0.3 parts by mass) were added and mixed at 3000 rpm for 1 minute to obtain toner 14. Table 4 shows the physical properties of Toner 14.

[Preparation of Toner 15]
Toner particles 2 (100 parts by mass), spherical particles 1 (0.2 parts by mass) and hydrotalcite particles (DHT-4A, manufactured by Kyowa Chemical Co., Ltd.) (0.3 parts by mass) are charged into Nobilta 130. The mixture was mixed for 10 minutes at a power of 1.2 kW. The obtained mixture and the above-described hydrophobic silica fine particles (1.0 part by mass) were charged into an FM mixer (manufactured by Nippon Coke Industries, Ltd., FM10C) and mixed at 4000 rpm for 10 minutes to obtain toner 15. . Table 4 shows the physical properties of Toner 15.

[Production of Toners 16 to 19]
Toners 16 to 19 were obtained in the same manner except that the types and addition amounts of toner particles, spherical particles and hydrotalcite particles were changed to the conditions shown in Table 4 in the production process of toner 1. Table 4 shows the physical properties of Toners 16 to 19.

[Example 1]
The toner 1 obtained by the above process was evaluated according to the following evaluation method. The obtained evaluation results are shown in Table 5.

  The evaluation method and evaluation criteria of the present invention will be specifically described below.

  A color laser beam printer (HP LaserJet Enterprise Color M553dn) manufactured by Hewlett-Packard was used as the image forming apparatus, and the image was modified so that the process speed was 300 mm / sec. An HP 508A genuine LaserJet toner cartridge (cyan) was used as the cartridge.

  The product toner was extracted from the inside of the cartridge, cleaned by air blow, and then filled with 150 g of the toner of the present invention. The toner was evaluated by performing the following durability test using the cartridge.

(1) Toner scattering under high temperature and high humidity environment From the viewpoint of charging stability, a durability test under high temperature and high humidity environment was carried out by the following method.

Printing rate on Canon color laser copier paper (A4: 81.4 g / m ² , this paper will be used unless otherwise specified) in a high temperature and high humidity environment (30 ° C / 80% RH) An endurance test was performed to output 10000 sheets of 0.5% images with an intermittent time of 2 seconds every two sheets. The cartridge was taken out of the printer main body every 1000 sheets printed, and the presence or absence of toner scattering around the developing roller was visually observed. From the result of visual observation, evaluation was performed according to the following evaluation criteria. The results are shown in Table 5. In this endurance test, it is known that when the chargeability of the toner is reduced, the electrostatic adhesion force of the toner to the developing roller is reduced and the toner is scattered around the developing roller.

(Evaluation criteria for toner scattering)
A: Toner scattering does not occur after outputting 10,000 sheets.
B: Very little toner scattering occurs after outputting 10,000 sheets.
C: Toner scattering occurs when the output number is 9000 sheets or less.
D: Toner scattering occurs when the number of output sheets is 1000 sheets or less.

(2) Fusion on Photoconductor and Developing Blade in Low Temperature and Low Humidity Environment In order to evaluate the durability of the toner, a durability test in a low temperature and low humidity environment was performed by the following method.

  In a low-temperature, low-humidity environment (15 ° C./10% RH), an endurance test was performed in which 10,000 images with a printing rate of 0.5% were output every two sheets with an intermittent time of 2 seconds. A solid image and a halftone image were output one by one as evaluation images every 1000 sheets printed. Further, after printing 10,000 sheets, the cartridge was taken out from the printer body, and the fused material on the photoreceptor and the developing blade was visually and microscopically observed. As a microscope, an ultra-deep shape measuring microscope (manufactured by Keyence Corporation) was used. From the evaluation image and the result of visual observation / microscopic observation, the fusion on the photosensitive member and the developing blade was evaluated based on the following criteria. In the case where the evaluation rank is C or less, the number of images in which image defects are confirmed is shown in Table 5. In this endurance test, when desorption of hydrotalcite particles, spherical particles, and other external additives from the toner occurs, a fusion product starting from agglomerates of fine particles grows, resulting in an evaluation result. It is known to get worse.

<Fusion on photoconductor>
A: There is no problem on the image, and no fused material is observed in the microscopic observation.
B: There is no problem in the image, and a slight fusion product is observed by microscopic observation.
C: A slight white spot image is confirmed in a part of the image, and a slight fusion product is observed in visual observation.
D: A fused product is observed by visual observation in which a white spot image of the photosensitive member period is confirmed on the image.

<Fusion on development blade>
A: There is no problem on the image, and no fused material is observed in the microscopic observation.
B: There is no problem in the image, and a slight fusion product is observed by microscopic observation.
C: Slight vertical white streaks are confirmed in a part of the image, and a slight fusion product is observed in visual observation.
D: A fused material is observed in visual observation in which vertical white stripes are confirmed on the image.

[Examples 2 to 11]
For toners 2 to 11, the same evaluation as in Example 1 was performed. The obtained evaluation results are shown in Table 5.

[Comparative Examples 1-8]
For toners 12 to 19, the same evaluation as in Example 1 was performed. The obtained evaluation results are shown in Table 5.

  In Examples 1 to 11, good results were obtained for any of the evaluation items. On the other hand, in Comparative Examples 1-8, it was a result inferior to an Example about either of the said evaluation items.

  From the above results, according to the present invention, it is possible to provide a toner having stable chargeability and high durability even when printing a large number of sheets at high speed.

  DESCRIPTION OF SYMBOLS 1 Photosensitive drum, 4 Developing unit, 7 Process cartridge, 13 Photosensitive unit, 15 Developing chamber, 17 Developing roller, 18 Toner storage chamber, 20 Toner supply roller, 22 Stirring conveyance member, 30 Developing opening, 80 Toner, 100 Image Forming equipment

Claims (6)

A toner having toner particles containing a binder resin,
On the surface of the toner particles,
(1) Spherical particles having a number average particle diameter (D1) of 70 nm to 200 nm and a roundness of 0.80 or more, and
(2) Hydrotalcite particles are present,
In the toner, the fixing rate of the hydrotalcite particles is 15% or more and 80% or less,
In the triboelectric charging train of the toner particles, the spherical particles, and the hydrotalcite particles, the toner particles, the spherical particles, and the hydrotalcite particles are in this order from the negative polarity side.
Toner characterized by the above.   2. The toner according to claim 1, wherein the number average particle diameter (D1) of the hydrotalcite particles contained in the toner is 0.1 μm or more and 1.00 μm or less.   The toner according to claim 1 or 2, wherein the amount of the hydrotalcite particles contained in the toner is 0.01 parts by mass or more and 3.00 parts by mass or less with respect to 100 parts by mass of the toner particles.   The addition amount of the spherical particles contained in the toner is 0.1 or more and 1.7 or less when the addition amount of the hydrotalcite particles is 1. 5. Toner.   The toner according to claim 1, wherein the spherical particles are sol-gel silica particles. 6. The toner particles according to claim 1, wherein the toner particles contain a polymer A having a structure a represented by the following formula (2), and the polymer A has a weight average molecular weight (Mw) of 1,000 to 100,000. The toner according to any one of the above.

(In the formula, R ¹ represents an alkyl group having 1 to 18 carbon atoms or an alkoxy group having 1 to 18 carbon atoms, and R ² represents a hydrogen atom, a hydroxy group, or an alkyl group having 1 to 18 carbon atoms. Group represents an alkoxy group having 1 to 18 carbon atoms, g represents an integer of 1 to 3, h represents an integer of 0 to 3, and when h is 2 or 3, R ¹ represents And can be selected independently, * is the binding site in polymer A)

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