JP7532082B2 - toner - Google Patents

Description

The present invention relates to a toner used in image forming methods such as electrophotography, electrostatic recording, and toner jet methods.

In recent years, there has been a widespread demand for printers and copiers to provide high image quality and durability, while at the same time, in the case of printers in particular, they must be compact and produce less waste.
Printers must be adapted to various business situations, such as network printers used by many people via a network, and personal printers used in SOHO, etc. In addition, in office and SOHO environments, there is a strong demand for maintenance-free printers that do not require waste toner replacement or other waste generation. Therefore, there is still a strong demand for space-saving printers, that is, compact printers and printers that do not produce waste.
In order to reduce the size of a printer, it is effective to reduce the size of the fixing device and the process cartridge. In particular, since the process cartridge occupies most of the volume of the printer, reducing the size of the process cartridge can greatly contribute to reducing the size of the printer.
In order to reduce the size of the process cartridge, it is effective to reduce the size of the developing device and cleaning device. When it comes to reducing the size of the developing device, there are two-component and one-component developing methods for electrophotography, but the one-component developing method is more suitable for miniaturization because it does not use components such as carriers.
Also, when focusing on the cleaning device, a cleanerless system that does not have a cleaning device in the first place is very suitable for miniaturizing the process cartridge. In many printers, the toner (transfer residual toner) remaining on the electrostatic latent image carrier (photoconductor) in the transfer process is scraped off by a cleaning blade or the like, and collected in a cleaning container to become waste toner. On the other hand, a cleanerless system does not have a cleaning blade or a cleaning container, and the transfer residual toner is collected again in the developing device and contributes to development, so the process cartridge can be significantly miniaturized, and no waste toner is generated, which greatly contributes to reducing waste. In a cleanerless system, the performance required of the toner is reduction in fogging. Fogging is an image problem in which a toner with a reduced charge amount develops non-regularly in a non-image area, and the charge stability of the toner is very important for reducing fogging. Patent Document 1 proposes a toner having a surface layer containing an organosilicon polymer in order to improve the charge stability of the toner.

JP 2018-194836 A

In a cleanerless system, for example, fillers and additives such as paper, which is a media, may adhere to the surface of the photoreceptor and be collected in the developing device as foreign matter (charge-inhibiting components). If these charge-inhibiting components are mixed or remain in the process cartridge (hereinafter also referred to as contamination), the toner may not be properly charged, which may lead to fogging. In particular, when paper containing talc is used as the media, when the talc is collected in the developing device, it is likely to adhere or fuse to the toner carrier due to its cleavage property, and at the same time, its charge-inhibiting property makes it easy to reduce the charge amount of the toner, resulting in fogging. This fogging phenomenon is particularly likely to occur under high temperature and high humidity conditions where the charge amount of the toner is relatively low.
According to Japanese Patent Laid-Open No. 2003-233699, the charging stability of the toner is improved and fogging is reduced, but there is still room for improvement depending on the usage environment and the type of paper.
As described above, cleanerless systems are an effective means of making printers smaller and less wasteful. However, there are still issues that need to be resolved with these cleanerless systems, such as limitations on the environments and paper types that they can be used with.
Therefore, an object of the present invention is to provide a toner that is less likely to cause fogging and is suitable for a cleaner-less system that can handle a wider range of usage environments and paper types.

The present invention provides a toner having toner particles each having a core particle and an outer shell covering the core particle,
The outer shell contains an organosilicon polymer and has missing portions, and when the coverage of the outer shell covering the core particle calculated from a backscattered electron image of a scanning electron microscope is X%, the standard deviation of X is Z, and the mass ratio of the outer shell to the core particle calculated from fluorescent X-ray measurement is Y%, the toner is characterized in that X, Y, and Z satisfy the following formula:
Y≦0.04X+0.2 (1)
40≦X≦95 (2)
Z≦5.0 (3)

A toner that is less prone to fogging is provided, making it suitable for cleanerless systems that can handle a wider range of usage environments and paper types.

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

In the present invention, "(meth)acrylic" means "acrylic" and/or "methacrylic".

The toner of the present invention is described in more detail below.

As a result of intensive research aimed at solving the problems of the conventional technology described above, the inventors have discovered that the above problems can be solved by forming a toner having toner particles with a core particle and an outer shell covering the core particle, the outer shell containing an organosilicon polymer being formed on the core particle in a specific state.

That is, the toner of the present invention is a toner having toner particles having a core particle and an outer shell covering the core particle, the outer shell containing an organosilicon polymer and having missing portions, characterized in that when the coverage of the outer shell covering the core particle calculated from a backscattered electron image of a scanning electron microscope is X%, the standard deviation of X is Z, and the mass ratio of the outer shell to the core particle calculated from fluorescent X-ray measurement is Y%, X, Y, and Z satisfy the following formula:
Y≦0.04X+0.2 (1)
40≦X≦95 (2)
Z≦5.0 (3)

Formula (1) means that when a material containing an organosilicon polymer is coated at a specific coverage rate X, its mass Y is coated at 0.04X+0.2 or less. In other words, by satisfying formula (1), the outer shell provides a uniform film with few irregularities. This allows for uniform charging within and between toner particles. Formula (2) indicates that there are missing parts in the outer shell, with the material part containing the organosilicon polymer being X% and the missing parts being (100-X)%. Furthermore, formula (3) indicates that the missing parts are more uniformly scattered. By having the toner particles have such a surface structure, charging inhibition is suppressed even if charging inhibition components are contaminated in the developing machine during printing, and the occurrence of fogging is suppressed.

X is preferably 70 or more and 90 or less. When X is 70 or more, the surface charging uniformity is improved, and fogging is further suppressed in both the presence and absence of charge-inhibiting components. When X is 90 or less, the tolerance for charge-inhibiting component contamination increases, and the print life is extended.

The maximum area of the missing portion of the outer shell is preferably 1.0×10 ⁵ nm ² or less. This is believed to improve the uniformity of charging. In particular, fogging under high temperature and high humidity conditions when a charging inhibiting component is mixed in is suppressed.

The missing portion of the outer shell preferably contains fine particles containing any of the elements of Groups 1 to 13 of the periodic table, such as Ca, Mg, Al, and Na. The electropositive nature of these elements is believed to improve the effect of capturing the charging inhibitors described below. This further suppresses fogging that occurs when charging inhibitors are mixed in.

Based on the above results, the present inventors consider the following regarding the occurrence of fogging due to the inclusion of charge-blocking components and the mechanism by which the toner of the present invention suppresses it. Charge-blocking components have the same charge polarity as the toner particle surface, and when the toner particle surface and charge-blocking components come into contact and peel off, the charge on the toner particle surface is lost. Toner particles with this damaged charge become fogging. In contrast, in the toner of the present invention, it is believed that during the development process, the outer shell containing the organosilicon polymer is charged, and the missing parts are not charged. Since the charge-blocking components have the same charge polarity as the charged outer shell, they are easily captured in the electrically neutral missing parts. For this reason, it is believed that charge inhibition is suppressed by the charge-blocking components being captured in the missing parts of the outer shell on the toner particle surface.

We will explain each component that makes up the toner and how to manufacture the toner.

<Binder resin>
The toner particles contain a binder resin. The content of the binder resin is preferably 50% by mass or more based on the total amount of the resin components in the toner particles.

There are no particular limitations on the binder resin, but examples include styrene-acrylic resin, epoxy resin, polyester resin, polyurethane resin, polyamide resin, cellulose resin, polyether resin, mixed resins or composite resins thereof. Styrene-acrylic resin and polyester resin are preferred because they are inexpensive, easily available, and have excellent low-temperature fixing properties. Furthermore, it is more preferred to include styrene-acrylic resin because they have excellent development durability.

Polyester resins can be obtained by selecting and combining suitable polycarboxylic acids, polyols, hydroxycarboxylic acids, etc., and synthesizing them using a conventional method such as the ester exchange method or polycondensation method.

Polycarboxylic acids are compounds that contain two or more carboxy groups in one molecule. Of these, dicarboxylic acids are compounds that contain two carboxy groups in one molecule and are preferably used.

For example, oxalic acid, succinic acid, glutaric acid, maleic acid, adipic acid, β-methyladipic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, fumaric acid, citraconic acid, diglycolic acid, cyclohexane-3,5-diene-1,2-carboxylic acid, hexahydroterephthalic acid, malonic acid, pimelic acid, suberic acid, phthalic acid, isophthalic acid, terephthalic acid, tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-carboxyphenylacetic acid, p-phenylenediacetic acid, m-phenylenediacetic acid, o-phenylenediacetic acid, diphenylacetic acid, diphenyl-p,p'-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, anthracenedicarboxylic acid, cyclohexanedicarboxylic acid, etc. can be mentioned.

Examples of polycarboxylic acids other than dicarboxylic acids include trimellitic acid, trimesic acid, pyromellitic acid, naphthalene tricarboxylic acid, naphthalene tetracarboxylic acid, pyrene tricarboxylic acid, pyrene tetracarboxylic acid, itaconic acid, glutaconic acid, n-dodecyl succinic acid, n-dodecenyl succinic acid, isododecyl succinic acid, isododecenyl succinic acid, n-octyl succinic acid, and n-octenyl succinic acid. These may be used alone or in combination of two or more.

Polyols are compounds that contain two or more hydroxyl groups in one molecule. Of these, diols are compounds that contain two hydroxyl groups in one molecule and are preferably used.

Specifically, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,14-eicosanedecanediol, diethylene glycol, tridecanediol, tetra ... Examples include polyethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-butenediol, neopentyl glycol, 1,4-cyclohexanediol, polytetramethylene glycol, hydrogenated bisphenol A, bisphenol A, bisphenol F, bisphenol S, and alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adducts of the above bisphenols.

Among these, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and their combination with alkylene glycols having 2 to 12 carbon atoms.

Examples of trihydric or higher alcohols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, hexamethylolmelamine, hexaethylolmelamine, tetramethylolbenzoguanamine, tetraethylolbenzoguanamine, sorbitol, trisphenol PA, phenol novolac, cresol novolac, and alkylene oxide adducts of the above trihydric or higher polyphenols. These may be used alone or in combination of two or more.

Examples of styrene-acrylic resins include homopolymers made of the following polymerizable monomers, copolymers obtained by combining two or more of these, and mixtures thereof.

Styrenic monomers such as styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene and p-phenylstyrene;
(meth)acrylic monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, iso-propyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, tert-butyl (meth)acrylate, n-amyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, dimethyl phosphate ethyl (meth)acrylate, diethyl phosphate ethyl (meth)acrylate, dibutyl phosphate ethyl (meth)acrylate, and 2-benzoyloxyethyl (meth)acrylate, (meth)acrylonitrile, 2-hydroxyethyl (meth)acrylate, (meth)acrylic acid, and maleic acid;
Vinyl ether monomers such as vinyl methyl ether and vinyl isobutyl ether;
Vinyl ketone monomers such as vinyl methyl ketone, vinyl ethyl ketone, and vinyl isopropenyl ketone;
Polyolefins such as ethylene, propylene, and butadiene.

For the styrene acrylic resin, a polyfunctional polymerizable monomer can be used as necessary. Examples of polyfunctional polymerizable monomers include diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 2,2'-bis(4-((meth)acryloxydiethoxy)phenyl)propane, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, divinylbenzene, divinylnaphthalene, and divinyl ether.

It is also possible to further add known chain transfer agents and polymerization inhibitors to control the degree of polymerization.

Polymerization initiators for obtaining styrene-acrylic resin include organic peroxide initiators and azo polymerization initiators.

Organic peroxide initiators include benzoyl peroxide, lauroyl peroxide, di-α-cumyl peroxide, 2,5-dimethyl-2,5-bis(benzoylperoxy)hexane, bis(4-t-butylcyclohexyl)peroxydicarbonate, 1,1-bis(t-butylperoxy)cyclododecane, t-butylperoxymaleic acid, bis(t-butylperoxy)isophthalate, methyl ethyl ketone peroxide, tert-butylperoxy-2-ethylhexanoate, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, and tert-butylperoxypivalate.

Azo polymerization initiators include 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobismethylbutyronitrile, and 2,2'-azobis-(methylisobutyrate).

Redox initiators, which combine an oxidizing substance and a reducing substance, can also be used as polymerization initiators.

Oxidizing substances include inorganic peroxides such as hydrogen peroxide, persulfates (sodium, potassium and ammonium salts) and oxidizing metal salts such as tetravalent cerium salts.

Reducing substances include reducing metal salts (divalent iron salts, monovalent copper salts, and trivalent chromium salts), ammonia, lower amines (amines with 1 to 6 carbon atoms, such as methylamine and ethylamine), amino compounds such as hydroxylamine, reducing sulfur compounds such as sodium thiosulfate, sodium hydrosulfite, sodium hydrogensulfite, sodium sulfite, and sodium formaldehyde sulfoxylate, lower alcohols (with 1 to 6 carbon atoms), ascorbic acid or its salts, and lower aldehydes (with 1 to 6 carbon atoms).

Polymerization initiators are selected with reference to their 10-hour half-life temperatures and are used alone or in combination. The amount of polymerization initiator added varies depending on the desired degree of polymerization, but generally 0.5 to 20.0 parts by mass are added per 100.0 parts by mass of polymerizable monomer.

<Release Agent>
In the toner of the present invention, a known wax can be used as a releasing agent.

Specific examples include petroleum waxes and their derivatives, such as paraffin wax, microcrystalline wax, and petroleum waxes such as petrolactam, montan wax and its derivatives, hydrocarbon waxes and their derivatives produced by the Fischer-Tropsch process, polyolefin waxes and their derivatives, such as polyethylene, and natural waxes and their derivatives, such as carnauba wax and candelilla wax. Derivatives also include oxides, block copolymers with vinyl monomers, and graft modified products.

Other examples include alcohols such as higher aliphatic alcohols; fatty acids such as stearic acid and palmitic acid or their acid amides, esters, and ketones; hydrogenated castor oil and its derivatives, vegetable waxes, and animal waxes. These can be used alone or in combination.

Among these, polyolefins, Fischer-Tropsch hydrocarbon waxes, or petroleum waxes are preferred because they tend to improve developability and transferability. These waxes may contain an antioxidant to the extent that it does not affect the effects of the toner of the present invention.

In terms of phase separation with respect to the binder resin or crystallization temperature, preferred examples include higher fatty acid esters such as behenyl behenate and dibehenyl sebacate.

The content of the release agent is preferably 1.0 parts by mass or more and 30.0 parts by mass or less per 100.0 parts by mass of the binder resin.

The melting point of the release agent is preferably 30°C or higher and 120°C or lower, and more preferably 60°C or higher and 100°C or lower.

By using a release agent that exhibits the thermal properties described above, the release effect is efficiently achieved and a wider fixing area is ensured.

<Plasticizer>
In the toner of the present invention, it is preferable to use a crystalline plasticizer in order to improve the sharp melting property. The plasticizer is not particularly limited, and any of the known plasticizers used in toners such as those described below can be used.

Specifically, esters of monohydric alcohols and aliphatic carboxylic acids, such as behenyl behenate, stearyl stearate, and palmityl palmitate, or esters of monohydric carboxylic acids and aliphatic alcohols; esters of dihydric alcohols and aliphatic carboxylic acids, such as ethylene glycol distearate, dibehenyl sebacate, and hexanediol dibehenate, or esters of dihydric carboxylic acids and aliphatic alcohols; esters of trihydric alcohols and aliphatic carboxylic acids, such as glycerin tribehenate, or esters of trihydric carboxylic acids and aliphatic alcohols; pentaerythritol tetrastearate, Esters of tetrahydric alcohols and aliphatic carboxylic acids, such as stearate and pentaerythritol tetrapalmitate, or esters of tetrahydric carboxylic acids and aliphatic alcohols; esters of hexahydric alcohols and aliphatic carboxylic acids, such as dipentaerythritol hexastearate and dipentaerythritol hexapalmitate, or esters of hexahydric carboxylic acids and aliphatic alcohols; esters of polyhydric alcohols and aliphatic carboxylic acids, such as polyglycerin behenate, or esters of polyhydric carboxylic acids and aliphatic alcohols; natural ester waxes, such as carnauba wax and rice wax. These can be used alone or in combination.

<Coloring Agent>
The toner particles may contain a colorant. Known pigments and dyes can be used as the colorant. Pigments are preferred as the colorant because they have excellent weather resistance.

Cyan colorants include copper phthalocyanine compounds and their derivatives, anthraquinone compounds, and basic dye lake compounds.

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

Examples of magenta colorants include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds.

Specific examples include the following: C.I. Pigment Red 2, 3, 5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221 and 254, and C.I. Pigment Violet 19.

Yellow colorants include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, and allylamide compounds.

Specific examples include the following: C.I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 185, 191 and 194.

Black colorants include carbon black and those toned to black using the above-mentioned yellow, magenta, and cyan colorants.

These colorants can be used alone or in mixtures, or even in the form of solid solutions.

It is preferable to use 1.0 parts by weight or more and 20.0 parts by weight or less of colorant per 100.0 parts by weight of binder resin.

<Charge control agent and charge control resin>
The toner particles may contain a charge control agent or resin.

As the charge control agent, any known charge control agent can be used, and charge control agents that have a high friction charging speed and can stably maintain a constant amount of frictional charge are particularly preferred. Furthermore, when the toner particles are produced by a suspension polymerization method, charge control agents that have low polymerization inhibition properties and are substantially free of solubilized substances in aqueous media are particularly preferred.

There are two types of charge control agents: those that control the toner to be negatively charged and those that control the toner to be positively charged.

Examples of substances that control the toner to be negatively charged include monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic and dicarboxylic acid-based metal compounds, aromatic oxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, phenol derivatives such as bisphenol, urea derivatives, metal-containing salicylic acid compounds, metal-containing naphthoic acid compounds, boron compounds, quaternary ammonium salts, calixarenes, and charge control resins.

Examples of charge control agents that control the toner to be positively charged include the following:

Guanidine compounds; imidazole compounds; quaternary ammonium salts such as tributylbenzylammonium 1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate, and onium salts such as phosphonium salts that are analogues of these, and lake pigments thereof; triphenylmethane dyes and lake pigments thereof (lake agents include phosphotungstic acid, phosphomolybdic acid, phosphotungstomolybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, and ferrocyanide); metal salts of higher fatty acids; charge control resins.

Among these charge control agents, metal-containing salicylic acid compounds are preferred, and those in which the metal is aluminum or zirconium are particularly preferred.

The charge control resin may be a polymer or copolymer having a sulfonic acid group, a sulfonate group, or a sulfonate ester group. As a polymer having a sulfonic acid group, a sulfonate group, or a sulfonate ester group, a polymer containing 2% by mass or more of a sulfonic acid group-containing acrylamide monomer or a sulfonic acid group-containing methacrylamide monomer in a copolymerization ratio is particularly preferred, and a polymer containing 5% by mass or more is more preferred.

The charge control resin preferably has a glass transition temperature (Tg) of 35°C or more and 90°C or less, a peak molecular weight (Mp) of 10,000 or more and 30,000 or less, and a weight average molecular weight (Mw) of 25,000 or more and 50,000 or less. When used, it is possible to impart desirable triboelectric charging properties without affecting the thermal properties required for the toner particles. Furthermore, since the charge control resin contains sulfonic acid groups, for example, the dispersibility of the charge control resin itself in the polymerizable monomer composition and the dispersibility of colorants and the like are improved, and the coloring power, transparency, and triboelectric charging properties can be further improved.

These charge control agents or charge control resins may be added alone or in combination of two or more types.

The amount of charge control agent or charge control resin added is preferably 0.01 parts by mass or more and 20.0 parts by mass or less, and more preferably 0.5 parts by mass or more and 10.0 parts by mass or less, per 100.0 parts by mass of binder resin.

<Carboxy group-containing styrene-based resin>
The carboxyl group-containing styrene-based resin preferably contains, as a copolymer component, styrene and at least one monomer selected from the group consisting of an acrylic acid monomer and a methacrylic acid monomer.

Other copolymerization components include acrylic acid esters and methacrylic acid esters; hydroxyalkyl acrylate esters and hydroxyalkyl methacrylate esters.

The carboxyl group-containing styrene resin is
Styrene,
At least one selected from the group consisting of acrylic acid and methacrylic acid;
At least one member selected from the group consisting of acrylic acid esters, methacrylic acid esters, hydroxyalkyl acrylic esters, and hydroxyalkyl methacrylic esters;
Preferred is a polymer of a monomer comprising:

More preferably, styrene and
At least one selected from the group consisting of acrylic acid and methacrylic acid;
at least one selected from the group consisting of methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, octyl acrylate, octyl methacrylate, dodecyl acrylate, dodecyl methacrylate, stearyl acrylate, stearyl methacrylate, behenyl acrylate, behenyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl acrylate, and 2-hydroxyethyl methacrylate,
It is a polymer of monomers containing:

The acid value of the carboxyl group-containing styrene-based resin can be adjusted to an appropriate value by the amount of at least one acid selected from the group consisting of acrylic acid and methacrylic acid contained in the monomer composition of the carboxyl group-containing styrene-based resin.

The weight average molecular weight of the carboxyl group-containing styrene-based resin is preferably 8,000 to 50,000.

The content of the carboxyl group-containing styrene resin in the binder resin is preferably 5% to 30% by mass.

<Organosilicon Polymer>
In the present invention, the toner particles have an outer shell containing an organosilicon polymer. The organosilicon polymer may be a polymer of an organosilicon compound having a structure represented by the following formula (4).

（式（４）中、Ｒ₁は、炭素数１以上６以下（好ましくは炭素数１以上３以下）の炭化水素基（好ましくはアルキル基）、又は、アリール基を表し、Ｒ₂、Ｒ₃及びＲ₄は、それぞれ独立して、ハロゲン原子、ヒドロキシ基、アセトキシ基、又は、（好ましくは炭素数１以上４以下の）アルコキシ基を表す。）

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

Specific examples of the above formula (4) include the following:

Examples include methyltrimethoxysilane, methyltriethoxysilane, methyltrichlorosilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrichlorosilane, ethyltriacetoxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltrichlorosilane, butyltrimethoxysilane, butyltriethoxysilane, butyltrichlorosilane, butylmethoxydichlorosilane, butylethoxydichlorosilane, hexyltrimethoxysilane, hexyltriethoxysilane, phenyltrimethoxysilane, and phenyltriethoxysilane. These can be used alone or in combination.

More preferably, the organosilicon polymer has a structure represented by formula (5) below.
R-SiO _3/2 ...(5)

Here, R represents a hydrocarbon group (preferably an alkyl group) having 1 to 6 carbon atoms (preferably 1 to 3 carbon atoms) or an aryl group.

A typical example of the production of organosilicon polymers is a method known as the sol-gel process.

It is generally known that in a sol-gel reaction, the bond state of the siloxane bond generated varies depending on the acidity of the reaction medium. Specifically, when the medium is acidic, a hydrogen ion electrophilically adds to the oxygen of one reactive group (e.g., an alkoxy group; -OR group). Next, an oxygen atom in a water molecule coordinates to a silicon atom, and becomes a hydrosilyl group through a substitution reaction. When there is sufficient water, one H ⁺ attacks one oxygen of a reactive group (e.g., an alkoxy group; -OR group), so when the content of H ⁺ in the medium is low, the substitution reaction to a hydroxyl group is slow. Therefore, a condensation polymerization reaction occurs before all of the reactive groups attached to the silane are hydrolyzed, and one-dimensional linear polymers and two-dimensional polymers are relatively easily generated.

On the other hand, when the medium is alkaline, hydroxide ions are added to silicon via a pentacoordinate intermediate. This makes it easier for all reactive groups (e.g., alkoxy groups; -OR groups) to be eliminated and easily substituted with silanol groups. In particular, when a silicon compound having three or more reactive groups on the same silane is used, hydrolysis and condensation polymerization occur three-dimensionally, forming an organosilicon polymer with many three-dimensional cross-linked bonds. The reaction also finishes in a short time.

In addition, the sol-gel method starts with a solution and forms the material by gelling the solution, so it can create a variety of fine structures and shapes. In particular, when the toner particles are produced in an aqueous medium, the hydrophilic properties of hydrophilic groups such as the silanol groups of the organosilicon compound make it easy to have them present on the surface of the toner particles.

Therefore, to form an organosilicon polymer, it is preferable to carry out the sol-gel reaction in an alkaline reaction medium. When producing in an aqueous medium, it is preferable to carry out the reaction at a pH of 8.0 or higher, at a reaction temperature of 50°C or higher, and for a reaction time of 5 hours or more. This allows the formation of an organosilicon polymer with greater strength and excellent durability.

<Toner Manufacturing Method>
The method for producing the toner particles is not particularly limited, and a known method can be used. For example, a melt kneading and grinding method, an emulsion aggregation method, a dissolution suspension method, etc. can be mentioned, and a suspension polymerization method is preferable. By using the suspension polymerization method, it is easy to obtain toner particles having an outer shell that satisfies the above formulas (1) to (3).

In the present invention, the following method is preferred for forming an outer shell containing an organosilicon polymer.

First, an aqueous dispersion of toner core particles carrying an inorganic particulate dispersant on their surfaces is obtained by suspension polymerization. At this time, the size and number of missing parts of the outer shell can be adjusted by adjusting the coating state of the inorganic particulate dispersant. The coating state of the inorganic particulate dispersant can be adjusted by changing the zeta potential, particle size, amount, etc. of the inorganic particulate dispersant. In addition, by having the inorganic particulate dispersant carry elements of Groups 1 to 13 of the periodic table, it is possible to introduce fine particles containing elements of Groups 1 to 13 of the periodic table into the missing parts of the outer shell.

Next, it is preferable to use an organosilicon compound that has been subjected to hydrolysis treatment. For example, the concentration of the hydrolysis feed is preferably 40 to 500 parts by mass of water from which ions have been removed, such as ion-exchanged water or RO water, and more preferably 100 to 400 parts by mass of water, assuming that the amount of the organosilicon compound is 100 parts by mass, and the hydrolysis conditions are preferably a pH of 2 to 7, a temperature of 15°C to 80°C, and a time of 30 to 600 minutes.

Next, the obtained hydrolysis liquid of the organosilicon compound is mixed with the toner core particle dispersion liquid to condense the organosilicon compound and form an outer shell containing an organosilicon polymer on the toner core particles. At this time, in addition to adjusting the coating state of the inorganic fine particle dispersant, it is possible to obtain toner particles having an outer shell that satisfies the above formulas (1) to (3) by further changing the condensation pH of the organosilicon compound, the addition time of the organosilicon compound hydrolysis liquid, and the number of additions.

The aqueous media used in the suspension polymerization method include the following:

Water, alcohols such as methanol, ethanol, and propanol, and mixed solvents of these. Water is preferred.

Dispersion stabilizers used when preparing the aqueous medium may be publicly known inorganic compound dispersion stabilizers and organic compound dispersion stabilizers. Inorganic compound dispersion stabilizers are preferred because of the ease of adjusting the outer shell.

Inorganic dispersion stabilizers include tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, and alumina.

On the other hand, examples of organic dispersion stabilizers include polyvinyl alcohol, gelatin, methyl cellulose, methylhydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, polyacrylic acid and its salts, and starch. The amount of these dispersion stabilizers used is preferably 0.2 parts by mass or more and 20.0 parts by mass or less per 100 parts by mass of the polymerizable monomer.

External additives may be added to the obtained toner particles to impart various properties to the toner. Examples of external additives to improve the fluidity of the toner include inorganic fine particles such as silica fine particles, titanium oxide fine particles, and composite oxide fine particles of these. Among the inorganic fine particles, silica fine particles and titanium oxide fine particles are preferred.

Examples of silica fine particles include dry silica or fumed silica produced by vapor-phase oxidation of silicon halides, and wet silica produced from water glass.

As inorganic fine particles, dry silica is preferred, which has few silanol groups on the surface and inside of the silica fine particles and also has few _Na2O and _SO32- . In addition, the dry silica may be a composite fine particle of silica and other metal oxides, ^which is obtained by using a metal halide compound such as aluminum chloride, titanium chloride, etc. together with a silicon halide compound in the manufacturing process.

By subjecting the surfaces of inorganic fine particles to a hydrophobic treatment using a treatment agent, it is possible to adjust the triboelectric charge of the toner, improve environmental stability, and improve fluidity under high temperature and high humidity conditions, so it is preferable to use inorganic fine particles that have been hydrophobized.

Examples of treatment agents for hydrophobizing inorganic fine particles include unmodified silicone varnish, various modified silicone varnishes, unmodified silicone oil, various modified silicone oils, silicon compounds, silane coupling agents, other organosilicon compounds, and organotitanium compounds. Among these, silicone oil is preferred. These treatment agents may be used alone or in combination.

The total amount of inorganic fine particles added is preferably 1.00 parts by mass or more and 5.00 parts by mass or less, and more preferably 1.00 parts by mass or more and 2.50 parts by mass or less, per 100 parts by mass of toner particles.

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

<Method of measuring the coverage rate X of the outer shell of a toner particle and its standard deviation Z>
A backscattered electron image of the surface of the toner particles was obtained by a scanning electron microscope (SEM).

The SEM equipment and observation conditions are as follows.
Equipment used: ULTRA PLUS manufactured by Carl Zeiss Microscopy Co., Ltd.
Acceleration voltage: 1.0 kV
WD: 2.0 mm
Aperture Size: 30.0μm
Detection signal: EsB (energy selective backscattered electrons)
EsB Grid: 800V
Observation magnification: 50,000 times Contrast: 63.0±5.0% (reference value)
Brightness: 38.0±5.0% (reference value)
Resolution: 1024 x 768
Pretreatment: Toner particles are scattered onto carbon tape (no deposition is performed)

The accelerating voltage and EsB Grid of the present invention are set to achieve the following: obtaining structural information on the outermost surface of the toner particles, preventing charging up of undeposited samples, and selectively detecting high-energy reflected electrons. The observation field is selected to be near the apex where the curvature of the toner particles is smallest.

The coverage rate X is obtained by analyzing the reflected electron image of the surface of the toner particles obtained by the above method using image processing software ImageJ (developed by Wayne Rashand). The procedure is as follows.

First, convert the backscattered electron image to be analyzed to 8-bit from Type in the Image menu. Next, set the Median diameter to 2.0 pixels from Filters in the Process menu to reduce image noise. After excluding the observation condition display section displayed at the bottom of the backscattered electron image, estimate the center of the image and use the Rectangle Tool on the toolbar to select a 1.5 μm square range from the center of the backscattered electron image.

Next, select Threshold from Adjust in the Image menu and click Apply to obtain a binarized image of the areas covered by the shell and the missing areas that are not covered.

Next, use the straight line tool (Straight Line) on the toolbar to select the scale bar in the observation condition display area displayed below the backscattered electron image. In this state, select Set Scale from the Analyze menu to open a new window, and the pixel distance of the selected straight line is entered in the Distance in Pixels field. Enter the value of the scale bar (e.g., 100) in the Known Distance field of the window, enter the unit of the scale bar (e.g., nm) in the Unit of Measurement field, and click OK to complete the scale setting. Next, select Histogram from the Analyze menu, read the Count value and Mode value in the opened window, and perform the following calculations.
Coverage rate X = Mode/Count x 100

The above procedure is carried out for 20 fields of view for the toner particles to be evaluated, and the average value is adopted as the final coverage rate X, and the standard deviation is adopted as Z.

<Method of Measuring Mass Ratio Y of Outer Shell of Toner Particle to Core Particle>
The mass ratio Y of the outer shell of the toner particle to the core particle is measured by the following method.

A wavelength-dispersive X-ray fluorescence analyzer "Axios" (manufactured by PANalytical) and the accompanying dedicated software "SuperQ ver. 4.0F" (manufactured by PANalytical) for setting measurement conditions and analyzing measurement data are used. Rh is used as the anode of the X-ray tube, the measurement atmosphere is vacuum, the measurement diameter (collimator mask diameter) is 27 mm, and the measurement time is 10 seconds. In addition, detection is performed using a proportional counter (PC) when measuring light elements, and a scintillation counter (SC) when measuring heavy elements.

For the measurement sample, 4 g of toner was placed in a special aluminum ring for pressing, flattened, and pressed at 20 MPa for 60 seconds using a tablet molding compression machine "BRE-32" (Maekawa Test Machinery Manufacturing Co., Ltd.) to form a pellet with a thickness of 2 mm and a diameter of 39 mm.

To 100 parts by weight of resin particles not containing an organosilicon polymer, 0.5 parts by weight of silica ( _SiO2 ) fine powder is added and thoroughly mixed using a coffee mill. Similarly, 5.0 parts by weight and 10.0 parts by weight of silica fine powder are mixed with the resin particles, respectively, to prepare samples for the calibration curve.

For each sample, a pellet of the calibration curve sample is prepared as described above using a tablet compression machine, and the count rate (unit: cps) of the Si-Kα ray observed at a diffraction angle (2θ) = 109.08° when PET is used as the analyzing crystal is measured. At this time, the acceleration voltage and current value of the X-ray generator are 24 kV and 100 mA, respectively. The count rate of the obtained X-ray is taken as the vertical axis, and the amount of SiO ₂ added in each calibration curve sample is taken as the horizontal axis to obtain a linear function calibration curve. Next, the toner to be analyzed is pelletized as described above using a tablet compression machine, and the count rate of the Si-Kα ray is measured. Then, the value on the horizontal axis is read from the above calibration curve, and this value is taken as Y.

<Method for measuring maximum area of missing part of outer shell of toner particle>
A binary image of the areas covered with the outer shell and the areas that are not covered is obtained using the same method as the method for measuring the coverage rate X of the outer shell of the toner particles and its standard deviation Z. Select Invert from the Edit menu to invert the black and white of the binary image.

Next, select Analyze Particles from the Analyze menu, set the Size column so that missing parts less than 400 ^nm2 are not counted (for example, 400-Infinity), set the Show column to Outlines, select Display results, Exclude on edges, Clear results, Include holes, and Summarize, and select OK. Read the Area value in the row with the Max Label value in the Results window that appears. The above procedure is performed for 20 fields of view for the toner particles to be evaluated, and the average value is adopted as the final maximum area of missing parts in the outer shell.

<Method of analyzing elements contained in missing parts>
The elements contained in the missing portion were confirmed by element mapping using energy dispersive X-ray analysis (EDS) that can be obtained using a scanning electron microscope (SEM).
The SEM/EDS equipment and observation conditions are as follows.
Equipment used (SEM): ULTRA PLUS manufactured by Carl Zeiss Microscopy Co., Ltd.
Equipment used (EDS): NORAN System 7, Ultra Dry EDS Detector, manufactured by Thermo Fisher Scientific Co., Ltd.
Acceleration voltage: 5.0 kV
WD: 7.0 mm
Aperture Size: 30.0μm
Detection signal: SE2 (secondary electrons)
Observation magnification: 50,000x Mode: Spectral Imaging
Pretreatment: Toner particles are scattered on carbon tape and platinum sputtered.

<Measurement of weight average particle diameter (D4) and number average particle diameter (D1) of toner or toner particles>
The weight average particle size (D4) and number average particle size (D1) of the toner or toner particles are measured using a precision particle size distribution measuring device by a narrow hole electrical resistance method equipped with a 100 μm aperture tube, “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.), and the accompanying dedicated software for setting measurement conditions and analyzing measurement data, “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.), with an effective measurement channel count of 25,000, and the measurement data is analyzed and calculated.

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

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

In the "Change Standard Measurement Method (SOM) Screen" of the dedicated software, set the total count number in control mode to 50,000 particles, the number of measurements to 1, and the Kd value to the value obtained using "Standard Particle 10.0 μm" (manufactured by Beckman Coulter). Press the threshold/noise level measurement button to automatically set the threshold and noise level. Also, set the current to 1600 μA, the gain to 2, the electrolyte to ISOTON II, and check the aperture tube flush after measurement.

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

The specific measurement method is as follows.
(1) Pour about 200 ml of the electrolyte solution into a 250 ml round-bottom glass beaker for use with the Multisizer 3, set it on the sample stand, and stir the stirrer rod counterclockwise at 24 revolutions per second. Then, remove dirt and air bubbles from inside the aperture tube using the "aperture tube flush" function of the dedicated software.
(2) Approximately 30 ml of the aqueous electrolyte solution is placed in a 100 ml flat-bottom glass beaker, and approximately 0.3 ml of a solution prepared by diluting "Contaminon N" (a 10% by weight aqueous solution of a neutral detergent for cleaning precision measuring instruments, consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, having a pH of 7, manufactured by Wako Pure Chemical Industries, Ltd.) three times by weight with ion-exchanged water is added as a dispersant.
(3) A predetermined amount of ion-exchanged water is placed in the water tank of an ultrasonic disperser "Ultrasonic Dispersion System Tetora 150" (manufactured by Nikkaki Bios Co., Ltd.) having two built-in oscillators with an oscillation frequency of 50 kHz and a phase shift of 180 degrees and an electrical output of 120 W, and about 2 ml of the Contaminon N is added to this water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. Then, the height position of the beaker is adjusted so that the resonance state of the liquid surface of the electrolytic solution in the beaker is maximized.
(5) In a state where the electrolyte solution in the beaker in (4) is irradiated with ultrasonic waves, about 10 mg of toner or toner particles is added little by little to the electrolyte solution and dispersed. Then, ultrasonic dispersion treatment is continued for another 60 seconds. During ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted so as to be 10°C or higher and 40°C or lower.
(6) Using a pipette, the electrolytic solution of (5) in which the toner or toner particles are dispersed is dropped into the round-bottom beaker of (1) placed in the sample stand, and the measurement concentration is adjusted to about 5%. Then, the measurement is continued until the number of particles measured reaches 50,000.
(7) The measurement data is analyzed using the dedicated software that comes with the device, and the weight average particle size (D4) is calculated. Note that when the dedicated software is set to graph/volume %, the "average diameter" on the "analysis/volume statistics (arithmetic mean)" screen is the weight average particle size (D4), and when the dedicated software is set to graph/number %, the "average diameter" on the "analysis/number statistics (arithmetic mean)" screen is the number average particle size (D1).

The present invention will be explained in more detail below with reference to examples. The present invention is not limited to the following examples. Note that "parts" in the text are by weight unless otherwise specified.

<Production Example of Carboxy Group-Containing Styrene-Based Resin 1>
300 parts of xylene was placed in the flask, and the inside of the vessel was thoroughly replaced with nitrogen while stirring, and then the temperature was raised to reflux.
・Styrene 92.53 parts・Methyl methacrylate 2.50 parts・2-hydroxyethyl methacrylate 2.50 parts・Methacrylic acid 2.48 parts・Perbutyl D (manufactured by Nippon Oil & Fats) 2.00 parts After adding the above mixed liquid, polymerization was carried out for 5 hours at a polymerization temperature of 175 ° C. and a pressure of 0.10 MPa. Thereafter, a desolvation process was carried out under reduced pressure for 3 hours to remove xylene and pulverize to obtain a carboxyl group-containing styrene-based resin 1. The obtained carboxyl group-containing styrene-based resin 1 had a weight average molecular weight (Mw) of 15000 and an acid value of 15 mg KOH / g.

<Production Example of Polyester Resin 1>
In an autoclave equipped with a pressure reducing device, a water separator, a nitrogen gas inlet device, a temperature measuring device, and a stirrer,
Terephthalic acid 21.0 parts Isophthalic acid 21.0 parts Bisphenol A-propylene oxide 2 mole adduct 89.5 parts Bisphenol A-propylene oxide 3 mole adduct 23.0 parts Potassium oxalate titanate 0.030 parts The polyester monomers were charged and reacted under a nitrogen atmosphere at normal pressure at 220°C for 15 hours, and further reacted under a reduced pressure of 10 to 20 mmHg for 1 hour to obtain polyester resin 1. The glass transition temperature (Tg) of polyester resin 1 was 74.8°C, and the acid value was 8.2 mgKOH/g.

<Production Example of Hydrolyzed Liquid of Organosilicon Compound>
In a reaction vessel equipped with a stirrer and a thermometer, 60.0 parts of ion-exchanged water was weighed, and the pH was adjusted to 3.0 using 10% by weight hydrochloric acid. This was heated with stirring to a temperature of 70°C. Then, 40.0 parts of methyltriethoxysilane, an organosilicon compound for the outer shell, was added and stirred for 2 hours or more to carry out hydrolysis. The end point of hydrolysis was confirmed by visual observation that the oil and water did not separate and became one layer, and the mixture was cooled to obtain a hydrolyzed liquid of the organosilicon compound for the outer shell.

<Production Example of Toner 1>
In a four-necked vessel equipped with a reflux tube, a stirrer, a thermometer, and a _nitrogen inlet tube, 700 parts of ion-exchanged water, 1000 parts of a 0.1 mol/L _Na3PO4 aqueous solution, and 24.0 parts of a 1.0 mol/L HCl aqueous solution were added, and the mixture was stirred at 12,000 rpm using a high-speed stirring device T.K. Homomixer (Tokushu Kika Kogyo Co., Ltd.) while being maintained at 60°C. 85 parts of a 1.0 mol/L _CaCl2 aqueous solution were gradually added thereto to prepare an aqueous dispersion containing a fine poorly water-soluble dispersion stabilizer _Ca3 ( _PO4 ) ₂ .
Styrene monomer 75.0 parts n-Butyl acrylate 25.0 parts Carboxy group-containing styrene resin 1 6.0 parts Hexanediol diacrylate 0.5 parts Copper phthalocyanine pigment (Pigment Blue 15:3) 6.5 parts Polyester resin 1 5.0 parts Charge control agent Bontron E-88 (manufactured by Orient Chemical Co., Ltd.) 0.7 parts Release agent (hydrocarbon wax, melting point: 79°C) 5.0 parts Plasticizer (ethylene glycol distearate) 15.0 parts The above materials were dispersed for 3 hours using an attritor (Mitsui Miike Chemical Engineering Co., Ltd.) to obtain a polymerizable monomer composition, which was then kept at 60°C for 20 minutes. Thereafter, a polymerizable monomer composition obtained by adding 12.0 parts of t-butyl peroxypivalate (40% toluene solution) as a polymerization initiator to the polymerizable monomer composition was charged into the aqueous medium, and granulation was carried out for 10 minutes while maintaining the rotation speed of the high-speed stirrer at 12,000 rpm.

Then, the high-speed stirring device was replaced with a propeller-type stirrer, the internal temperature was raised to 70°C, and the mixture was allowed to react for 5 hours while slowly stirring to obtain toner base (core particles) 1.

Next, the internal temperature of the aqueous dispersion was set to 55°C, the pH was adjusted to 9.0 using an aqueous sodium hydroxide solution, and 15.2 parts of the hydrolyzed solution of the organosilicon compound was added dropwise over 2 hours, followed by a further reaction for 5 hours to form an outer shell. After cooling to 30°C, 10% hydrochloric acid was added to remove the dispersion stabilizer. The mixture was then filtered, washed, and dried to obtain toner particles 1 with a weight average particle size of 6.1 μm. The obtained toner particles 1 were designated as toner 1.

The amount of hydrolysis liquid of the organosilicon compound added for Toner 1 and its physical properties are shown in Table 1.

<Production Examples of Toners 2 to 4 and Comparative Toner 2>
Toners 2 to 4 and Comparative Toner 2 were obtained in the same manner as Toner 1, except that the amount of the hydrolyzed liquid of an organosilicon compound added was changed as shown in Table 1. The amount of the hydrolyzed liquid of an organosilicon compound added and the physical properties of Toners 2 to 4 and Comparative Toner 2 are shown in Table 1.

<Production Example of Toner 5>
Toner 5 was obtained in the same manner as for Toner 1, except that after obtaining the aqueous dispersion of the toner base, 43 parts of a 1.0 mol/L _CaCl2 aqueous solution was gradually added thereto as an additional salt, and the mixture was stirred at 70° C. for 1 hour. The amount of the hydrolyzed liquid of the organosilicon compound, the additional salt, and the physical properties of Toner 5 are shown in Table 1.

<Production Examples of Toners 6 to 8>
Toners 6 to 8 were obtained in the same manner as Toner 5, except that the types of additionally added salts were changed as shown in Table 1. The amounts of the hydrolyzed solution of organosilicon compounds added, the types of additionally added salts, and the physical properties of Toners 6 to 8 are shown in Table 1.

<Production Example of Comparative Toner 1>
An aqueous dispersion of the toner base was obtained in the same manner as in the production example of Toner 1.

Next, the internal temperature was adjusted to 55°C, 24.0 parts of hydrolyzed liquid of an organosilicon compound was added, and the mixture was held for 30 minutes. The pH was then adjusted to 9.0 using an aqueous sodium hydroxide solution, and the mixture was held for another 5 hours to form an outer shell. After cooling to 30°C, 10% hydrochloric acid was added to remove the dispersion stabilizer. The mixture was then filtered, washed, and dried to obtain comparative toner particles 1 with a weight average particle size of 6.3 μm. The obtained comparative toner particles 1 were used as comparative toner 1. The amount of hydrolyzed liquid of an organosilicon compound added and the physical properties of comparative toner 1 are shown in Table 1.

<Production Example of Comparative Toner 3>
"Synthesis of polyester resin 2"
Bisphenol A ethylene oxide 2 mole adduct 9 mol Bisphenol A propylene oxide 2 mole adduct 95 mol Terephthalic acid 50 mol Fumaric acid 30 mol Dodecenyl succinic acid 25 mol The above monomers were charged into a flask equipped with a stirrer, a nitrogen inlet tube, a temperature sensor, and a rectification column, and the temperature was raised to 195°C in 1 hour, and it was confirmed that the reaction system was stirred uniformly. 1.0 part of tin distearate was added to 100 parts of these monomers. The temperature was raised from 195°C to 250°C over 5 hours while distilling off the water produced, and a dehydration condensation reaction was carried out at 250°C for another 2 hours.

As a result, amorphous polyester resin 2 having a glass transition temperature of 60.2°C, an acid value of 13.8 mgKOH/g, a hydroxyl value of 28.2 mgKOH/g, a weight average molecular weight of 14,200, a number average molecular weight of 4,100 and a softening point of 111°C was obtained.
"Synthesis of polyester resin 3"
Bisphenol A-ethylene oxide 2-mol adduct 48 mol parts Bisphenol A-propylene oxide 2-mol adduct 48 mol parts Terephthalic acid 65 mol parts Dodecenyl succinic acid 30 mol parts The above monomers were added to a flask equipped with a stirrer, a nitrogen inlet tube, a temperature sensor, and a distillation column, and the temperature was raised to 195 ° C. in 1 hour, and it was confirmed that the reaction system was uniformly stirred. 0.7 parts of tin distearate were added to 100 parts of these monomers. The temperature was then raised from 195 ° C. to 240 ° C. over 5 hours while distilling off the water produced, and a dehydration condensation reaction was carried out at 240 ° C. for another 2 hours. Next, the temperature was lowered to 190 ° C., and 5 mol parts of trimellitic anhydride were gradually added, and the reaction was continued at 190 ° C. for 1 hour.

As a result, polyester resin 3 having a glass transition temperature of 55.2°C, an acid value of 14.3 mgKOH/g, a hydroxyl value of 24.1 mgKOH/g, a weight average molecular weight of 53,600, a number average molecular weight of 6,000 and a softening point of 108°C was obtained.
"Preparation of Resin Particle Dispersion 1"
Polyester resin 2 100 parts Methyl ethyl ketone 50 parts Isopropyl alcohol 20 parts Methyl ethyl ketone and isopropyl alcohol were added to the container. Then, the above resin was gradually added, stirred, and completely dissolved to obtain a polyester resin 2 solution. The container containing this polyester resin 2 solution was set to 65°C, and while stirring, 10% aqueous ammonia was gradually dropped to a total of 5 parts, and 230 parts of ion-exchanged water were gradually dropped at a rate of 10 ml/min to cause phase inversion emulsification. The pressure was further reduced with an evaporator to remove the solvent, and a resin particle dispersion 1 of polyester resin 2 was obtained. The volume average particle size of this resin particle was 135 nm. In addition, the resin particle solid content was adjusted to 20% with ion-exchanged water.
"Preparation of Resin Particle Dispersion 2"
Polyester resin 3 100 parts Methyl ethyl ketone 50 parts Isopropyl alcohol 20 parts Methyl ethyl ketone and isopropyl alcohol were added to the container. Then, the above materials were gradually added, stirred, and completely dissolved to obtain a polyester resin 3 solution. The container containing this polyester resin 3 solution was set to 40°C, and while stirring, 10% aqueous ammonia was gradually dropped to a total of 3.5 parts, and 230 parts of ion-exchanged water were gradually dropped at a rate of 10 ml/min to cause phase inversion emulsification. The pressure was further reduced to remove the solvent, and a resin particle dispersion 2 of polyester resin 3 was obtained. The volume average particle size of the resin particles was 155 nm. The resin particle solid content was adjusted to 20% with ion-exchanged water.
"Preparation of colorant particle dispersion"
Copper phthalocyanine (Pigment Blue 15:3) 45 parts Ionic surfactant NEOGEN RK (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) 5 parts Ion-exchanged water 190 parts The above components were mixed and dispersed for 10 minutes using a homogenizer (IKA Ultra Turrax), and then dispersed for 20 minutes at a pressure of 250 MPa using an Ultimizer (opposed collision type wet grinder: manufactured by Sugino Machine Ltd.) to obtain a colorant particle dispersion having a volume average particle size of 120 nm and a solid content of 20%.
"Preparation of release agent particle dispersion"
Release agent (hydrocarbon wax, melting point: 79° C.) 15 parts Plasticizer (ethylene glycol distearate) 45 parts Ionic surfactant NEOGEN RK (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 2 parts Ion-exchanged water 240 parts The above was heated to 100° C. and thoroughly dispersed using an Ultra-Turrax T50 manufactured by IKA. The mixture was then heated to 115° C. using a pressure discharge type Gaulin homogenizer and subjected to a dispersion treatment for 1 hour, thereby obtaining a release agent particle dispersion having a volume average particle size of 160 nm and a solid content of 20%.
"Preparation of Comparative Toner Particle 3"
Resin particle dispersion 1 500 parts Resin particle dispersion 2 400 parts Colorant particle dispersion 50 parts Release agent particle dispersion 165 parts After adding 2.2 parts of ionic surfactant Neogen RK to the flask, the above materials were stirred. Next, 1 mol/L nitric acid aqueous solution was dropped to adjust the pH to 3.7, and then 0.35 parts of polyaluminum sulfate was added to it, and dispersion was performed with an IKA Ultra Turrax. The flask was heated to 55°C while stirring in a heating oil bath. It was held at 55°C for 40 minutes.

Next, 40.0 parts of hydrolyzed liquid of an organosilicon compound was added while maintaining the internal temperature at 55°C. After maintaining the mixture as it was for 30 minutes, the pH was adjusted to 9.0 using an aqueous sodium hydroxide solution and maintained for an additional 5 hours to form an outer shell. After cooling to 30°C, the mixture was filtered, washed, and dried to obtain comparative toner particles 3. The obtained comparative toner particles 3 were used as comparative toner 3. The amount of hydrolyzed liquid of an organosilicon compound added and the physical properties of comparative toner 3 are shown in Table 1.

<Production Example of Toner Carrier 1>
The toner carrier 1 was manufactured by the following procedure.

(Synthesis of isocyanate-terminated prepolymer)
Under a nitrogen atmosphere, the following materials were gradually added dropwise to 17.7 parts of tolylene diisocyanate (TDI) (product name: Cosmonate T80; manufactured by Mitsui Chemicals, Inc.) in a reaction vessel while maintaining the temperature inside the reaction vessel at 65°C.
Polypropylene glycol polyol (product name: Exenol 4030; manufactured by Asahi Glass Co., Ltd.) 100.0 g
After the dropwise addition was completed, the mixture was reacted for 2 hours at 65° C. The resulting reaction mixture was cooled to room temperature to obtain an isocyanate-terminated prepolymer having an isocyanate group content of 3.8% by mass. (Synthesis of Amino Compound)
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device and a temperature regulator, 100.0 parts (1.67 moles) of ethylenediamine and 100 parts of pure water were heated to 40°C while stirring. Next, 425.3 parts (7.35 moles) of propylene oxide were gradually dropped over 30 minutes while maintaining the reaction temperature at 40°C or less. The reaction was continued for another hour with stirring to obtain a reaction mixture. The obtained reaction mixture was heated under reduced pressure to distill off water, and 426 g of an amino compound was obtained.

(Preparation of the substrate)
A ground aluminum cylindrical tube having an outer diameter of 10 mm and an arithmetic mean roughness Ra of 0.2 μm was used as a substrate, and a primer (product name: DY35-051; manufactured by Dow Corning Toray Co., Ltd.) was applied and baked.

(Preparation of Elastic Roller)
The substrate prepared above was placed in a mold, and an addition type silicone rubber composition prepared by mixing the following materials was poured into a cavity formed in the mold.
Liquid silicone rubber material (product name: SE6724A/B; manufactured by Dow Corning Toray Co., Ltd.) 100 parts,
Carbon black (product name: Toka Black #4300; manufactured by Tokai Carbon Co., Ltd.) 15 parts,
Silica powder as a heat resistance imparting agent: 0.2 parts
・Platinum catalyst 0.1 part.

The mold was then heated to vulcanize and harden the silicone rubber composition at a temperature of 150°C for 15 minutes. After the base body with the hardened silicone rubber layer formed on its periphery was removed from the mold, the base body was further heated at a temperature of 180°C for 1 hour to complete the hardening reaction of the silicone rubber layer. In this way, an elastic roller was produced in which a silicone rubber elastic layer with a thickness of 0.5 mm and a diameter of 11 mm was formed on the outer periphery of the base body.

(Preparation of surface layer)
The following materials for the surface layer were mixed by stirring.
Isocyanate-terminated prepolymer 617.9 parts,
34.2 parts of amino compound,
Carbon black (product name: MA230; manufactured by Mitsubishi Chemical Corporation) 117.4 parts,
- Urethane resin particles (product name: Art Pearl C-400; manufactured by Negami Chemical Industries, Ltd.)
130.4 parts.

Next, MEK (methyl ethyl ketone) was added so that the total solids ratio was 30% by mass to prepare the paint for forming the surface layer.

Next, the previously prepared elastic roller was masked in the areas without rubber, stood upright, and rotated at 1,500 rpm while the spray gun was lowered at 30 mm/sec to apply the coating. The coating was then cured and dried by heating at 180°C for 20 minutes in a hot air drying oven, yielding a toner carrier 1 with a surface layer of approximately 8 μm thickness on the outer periphery of the elastic layer.

[Toner Evaluation]
For the image output evaluation, a commercially available laser printer LASERJET PRO P1606 (manufactured by Hewlett-Packard Company) was modified and used.

The process cartridge of the above evaluation machine was removed, and the cleaning blade was removed from the cartridge to create a cleanerless system. The toner carrier was then changed to the above toner carrier 1, and installed so that it would develop in contact with the photoreceptor, and the development bias was modified so that only DC could be applied, allowing a bias to be applied from the outside. The following product toner was removed, and 150 g of toner 1 was filled.

<Fog rating 1 (plain paper, N/N)>
The cartridge was left to stand for 24 hours under normal temperature and humidity (N/N, temperature 23° C./humidity 50% RH) and then image output was evaluated. Plain paper (A4 size XEROX 4200 paper, manufactured by XEROX, 75 g/m ² ) was used as the medium.

After passing 6,000 sheets of an image with a printing ratio of 1%, the fog toner on the photoconductor of the solid white image was taped, the taped tape was attached to a blank sheet of paper, and the fog density (%) was calculated as the difference from the tape without taping. Note that a TC-6DS (manufactured by Tokyo Denshoku Co., Ltd.) was used to measure fog, and the fog density (%) was calculated as the average value of 5 points, and was judged according to the following index.
A: Less than 5% B: 5% to less than 10% C: 10% to less than 15% D: 15% to less than 20% E: 20% or more

<Fog Evaluation 2 (talc paper, N/N)>
The cartridge was left to stand for 24 hours under normal temperature and humidity (N/N, temperature 23° C./humidity 50% RH) environment, and then image output evaluation was performed. Talc paper CTM-2 (manufactured by Oji Paper Co., Ltd.) was used as the media.

After 3,000 sheets of an image with a printing ratio of 1%, the fog toner on the photoconductor of a solid white image was taped, the taped tape was attached to a blank sheet of paper, and the fog density (%) was calculated as the difference from the tape without taping. Note that a TC-6DS (manufactured by Tokyo Denshoku Co., Ltd.) was used to measure fog, and the fog density (%) was calculated as the average value of 5 points, and was judged according to the following index.
A: Less than 5% B: 5% to less than 10% C: 10% to less than 15% D: 15% to less than 20% E: 20% or more

<Fog rating: 3 (talc paper, N/N)>
The cartridge was left to stand for 24 hours under normal temperature and humidity (N/N, temperature 23° C./humidity 50% RH) environment, and then image output evaluation was performed. Talc paper CTM-2 (manufactured by Oji Paper Co., Ltd.) was used as the media.

After 6,000 sheets of an image with a printing ratio of 1%, the fog toner on the photoconductor of a solid white image was taped, the taped tape was attached to a blank sheet of paper, and the fog density (%) was calculated as the difference from the tape without taping. Note that a TC-6DS (manufactured by Tokyo Denshoku Co., Ltd.) was used to measure fog, and the fog density (%) was determined by the average value of five points, and was judged according to the following index.
A: Less than 5% B: 5% to less than 10% C: 10% to less than 15% D: 15% to less than 20% E: 20% or more

<Fog rating: 4 (talc paper, H/H)>
The cartridge was left standing for 24 hours in a high temperature and high humidity (H/H, temperature 30° C./humidity 80% RH) environment, and then image output evaluation was performed. Talc paper CTM-2 (manufactured by Oji Paper Co., Ltd.) was used as the media.

The fog toner on the photoconductor of a solid white image after 3,000 sheets of paper were passed through with an image having a printing ratio of 1% was taped, the taped tape was attached to a white paper, and the fog density (%) was calculated as the difference with the tape without taping. Note that, for the fog measurement, a TC-6DS (manufactured by Tokyo Denshoku Co., Ltd.) was used, and the fog density (%) was determined by the average value of 5 points, and was judged according to the following index.
A: Less than 5% B: 5% to less than 10% C: 10% to less than 15% D: 15% to less than 20% E: 20% or more

[Examples 1 to 8]
In Examples 1 to 8, the above-mentioned evaluations were carried out using Toners 1 to 8, respectively. The evaluation results are shown in Table 2.

[Comparative Examples 1 to 3]
In Comparative Examples 1 to 3, the above-mentioned evaluations were carried out using Comparative Toners 1 to 3, respectively. The evaluation results are shown in Table 2.

The numbers in parentheses in the table indicate the fog concentration.

Claims (5)

A toner having toner particles each having a core particle and an outer shell covering the core particle,
The toner is characterized in that the outer shell contains an organosilicon polymer and has missing portions, and when the coverage of the outer shell covering the core particle calculated from a backscattered electron image of a scanning electron microscope is X%, the standard deviation of X is Z, and the mass ratio of the outer shell to the core particle calculated from fluorescent X-ray measurement is Y%, X, Y, and Z satisfy the following formula:
Y≦0.04X+0.2 (1)
40≦X≦95 (2)
Z≦5.0 (3) The toner according to claim 1, wherein X is 70≦X≦90. 3. The toner according to claim 1, wherein the maximum area of the missing portion is 1.0×10 ⁵ nm ² or less. The toner according to any one of claims 1 to 3, wherein the missing portion has fine particles containing an element from any one of groups 1 to 13 of the periodic table. The toner according to any one of claims 1 to 4, wherein the toner is used in a process cartridge of a cleanerless system.