JP2002116574A - Toner and method of manufacturing the same as well as image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide polymerized toners which are little in the amount of color ing agents on particle surfaces and do not give rise to a change in image densi ty, fogging and a change in color tones occurring in the change in electrostatic chargeability and developability even when the toners are subjected to image formation for a long period under the high-humidity environment. SOLUTION: The toners consist of the toner particles obtained by forming resin layers (shells) fused with resin particles by a salting-out/fusing method on the surfaces of colored particles (core particles) containing a resin and coloring agents.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a toner, a method for producing the same, and an image forming method.

[0002]

2. Description of the Related Art Conventionally, a technique for producing a toner for developing an electrostatic latent image by a polymerization method is known. For example, toner particles are obtained by a suspension polymerization method. However, toner particles obtained by the suspension polymerization method are spherical and have a disadvantage that cleaning properties are poor. Thus, a method has been disclosed in which irregular shaped toner particles are obtained by associating resin particles and colorant particles obtained by an emulsion polymerization method (see JP-A-63-186253).

[0003]

However, since the colorant is exposed on the surface of the toner particles obtained in this manner, when the toner is used for a long term image formation in a high humidity environment, for example, The chargeability and developability change. The change in the chargeability and the developability of the toner causes a change (decrease) in image density and the occurrence of fogging, and also causes a change in tint in color image formation.

The present invention has been made based on the above circumstances. A first object of the present invention is to provide a polymerized toner having a small amount of a colorant on the surface of a particle. A second object of the present invention is to provide a polymerized toner which does not cause a change in image density or fog due to a change in chargeability and developability even when subjected to long-term image formation in a high humidity environment. is there. A third object of the present invention is to provide a polymerized toner having a small change in color due to a change in chargeability and developability even when subjected to long-term color image formation in a high humidity environment. A fourth object of the present invention is to provide a method capable of suitably producing the above-mentioned excellent polymerized toner. A fifth object of the present invention is to provide an image forming method using the above-mentioned excellent polymerized toner.

[0005]

Means for Solving the Problems The toner of the present invention comprises a resin layer (fused with resin particles by a salting out / fusion method) on the surface of colored particles (core particles) containing a resin and a colorant. (Shell) is formed of the formed toner particles.

The toner of the present invention comprises a resin particle (B) formed on a surface of a colored particle (core particle) obtained by salting out / fusing the resin particle (A) and the colorant particle by a salting out / fusion method.
Is characterized by comprising toner particles on which a resin layer (shell) formed by fusing is formed.

In the toner of the present invention, the resin particles (A) have a weight average molecular weight (MwA) of 15,000 to 5
000 and the weight average molecular weight (Mw
A) and the weight average molecular weight (Mw) of the resin particles (B).
It is preferable that the following formula be satisfied between the two.

Formula) 0.1 ≦ (MwA / MwB) ≦ 20.0

In the toner of the present invention, the resin fine particles (B) have a weight average molecular weight (Mw) of from 5,000 to 5,000.
Preferably, it contains 20,000 low molecular weight resins.

In the toner of the present invention, it is preferable that at least one of the resin particles (A) and the resin fine particles (B) is a composite resin particle obtained by a multistage polymerization method.

The production method of the present invention comprises a step of forming a resin layer (shell) by fusing the resin particles to the surface of the colored particles (core particles) containing the resin and the colorant by salting out / fusing. It is characterized by including.

In the production method of the present invention, the resin particles (A) and the colorant particles are subjected to salting-out / fusion to form colored particles (core particles).
And a step of fusing the resin particles (B) to the surface of the obtained colored particles (core particles) by salting out / fusion to form a resin layer (shell). .

In the production method of the present invention, it is preferred that the step of forming colored particles (core particles) and the step of forming a resin layer (shell) on the surface of the colored particles are performed continuously.

In the production method of the present invention, colored particles (core particles) having an average circularity of 0.850 to 0.950
It is preferable to include a step of forming a resin layer (shell) on the surface of the substrate.

In the production method of the present invention, the weight average molecular weight (MwA) of the resin particles (A) is 15,000 to
500,000 and the weight average molecular weight (M
wA) and the weight average molecular weight (Mw) of the resin particles (B).
It is preferable that the following formula be satisfied between the two.

Formula) 0.1 ≦ (MwA / MwB) ≦ 20.0

In the production method of the present invention, the resin fine particles (B) have a weight average molecular weight (Mw) of 5,000.
It is preferable that a low molecular weight resin of up to 20,000 is contained.

In the production method of the present invention, it is preferable that at least one, preferably both, of the resin particles (A) and the resin fine particles (B) are composite resin particles obtained by a multistage polymerization method.

The image forming method of the present invention is an image forming method including a fixing step by a contact heating method, and is characterized by using the toner of the present invention.

[0020]

Since the surface of the colored particles (core particles) containing the colorant is covered with a high-resistance resin layer (shell) to constitute the toner particles, the colorant is exposed on the surface of the toner particles. do not do. As a result, even if the image formation is performed for a long time in a high humidity environment, the chargeability and the developability can be stabilized. Further, there is no variation in surface characteristics between toner particles, the charge amount distribution is sharp, and a visible image with good sharpness can be formed for a long time. In addition, low-molecular-weight resin (Mw = 5,000 to 20, 20) is contained in resin fine particles (B) for forming a resin layer (shell).
000), the resin fine particles (B) are excellent in the fusion property and film formability to the surface of the colored particles, and the surface shape of the obtained toner particles can be smoothed. .

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION <Structure of Toner> The toner of the present invention comprises a resin layer (shell) substantially free of a colorant, formed of toner particles formed on the surface of colored particles (core particles). You. Resin layer (shell) constituting toner particles
Is formed by fusing resin particles [resin particles (B)] to the surface of colored particles (core particles) by a salting out / fusion method. Colored particles (core particles) can be produced by salting out / fusing resin particles [resin particles (A)] and colorant particles.

In the present invention, "salting out / fusion" means that salting out (aggregation of fine particles) and fusion (loss of interface between fine particles) occur simultaneously, or that salting out and fusion occur simultaneously. Refers to the act of waking up. In order to carry out salting out and fusion simultaneously, the glass transition temperature (T
g) The particles need to be aggregated under the above temperature conditions.

<Molecular Weight of Toner (Core Particles)> The weight average molecular weight (MwA) of the resin particles (A) constituting the colored particles (core particles) is usually 15,000 to 500,000, preferably 20,000. 2,000 to 200,000, more preferably 25,000 to 150,000.

The resin particles (A) may be composed of a plurality of resin particles having different molecular weights (eg, high-molecular-weight resin particles, intermediate-molecular-weight resin particles, low-molecular-weight resin particles), or may be formed by a multi-stage polymerization method. It may be composed of resin particles (composite resin particles) in which different resins are multilayered (composite). That is, the colored particles (core particles) are formed by salting out / fusing a plurality of resin particles having different molecular weights and the colorant particles, or by salting out / fusing the composite resin particles and the colorant particles. Can be obtained by

The weight average molecular weight (Mw) of the high molecular weight resin particles (high molecular weight component of the composite resin particles) constituting the resin particles (A) is usually from 160,000 to 500,000. By using the resin particles (A) composed of such high molecular weight resin particles (high molecular weight components), it is possible to impart sufficient internal cohesion (offset resistance at high temperatures) to the obtained toner.

The weight average molecular weight (Mw) of the low molecular weight resin particles (low molecular weight component of the composite resin particles) constituting the resin particles (A) is usually from 15,000 to 20,000. By using the resin particles (A) composed of such low-molecular-weight resin particles (low-molecular-weight components), excellent fixability (adhesion to an image-forming support) can be imparted to the obtained toner.

The weight average molecular weight (Mw) of the intermediate molecular weight resin particles (the intermediate molecular weight component of the composite resin particles) constituting the resin particles (A) is usually from 20,001 to 159,999.

<Molecular Weight of Toner (Shell)> The weight average molecular weight (M) of the resin particles (B) constituting the resin layer (shell)
wB) is the weight average molecular weight (MwA) of the resin particles (A)
With respect to the formula): 0.1 ≦ (MwA / MwB) ≦ 20.
It is preferable that the value be in a range where 0 is satisfied. The weight average molecular weight (MwB) of the resin particles (B) is 5,000.
Preferably it is ~ 200,000.

The resin constituting the resin particles (B) has a weight average molecular weight (Mw) of 5, 0 or
It is preferable to contain a low molecular weight resin of from 00 to 20,000. By containing the low molecular weight resin in the resin fine particles (B), the resin fine particles (B) have excellent fusion and film forming properties to the surface of the colored particles, and the surface of the obtained toner particles The shape can be smoothed, and excellent fixability can be imparted to the obtained toner. Among the resins constituting the resin particles (B), the ratio of the low molecular weight resin (Mw = 5,000 to 20,000) is preferably 20 to 80% by mass, and more preferably 30 to 70% by mass. It is said.

A part of the resin constituting the resin particles (B) has a weight average molecular weight (Mw) of 20,000 to 12
It is preferred that it contains a 000 intermediate molecular weight resin.

The resin particles (B) may be composed of a plurality of resin particles having different molecular weights (for example, intermediate molecular weight resin particles and low molecular weight resin particles), or may be formed by multilayering resins having different molecular weights by a multi-stage polymerization method. It may be composed of (composite) resin particles (composite resin particles). That is, the resin layer (shell) can be formed by salting out / fusing a plurality of resin particles having different molecular weights, or by salting out / fusing composite resin particles.

<Measuring method of molecular weight> Weight average molecular weight of resin particles (A) [Individual weight average molecular weight and total weight average molecular weight (M for a plurality of resin particles having different molecular weights)
wA)] and the weight average molecular weight of the resin particles (B) [the individual weight average molecular weights and the total weight average molecular weight (MwB) of a plurality of resin particles having different molecular weights] are GP
It is a molecular weight in terms of styrene measured using C (gel permeation chromatography).

As a method for measuring the molecular weight of the resin by GPC, 0.5 to 5.0 mg (specifically, 1 m
1 g of THF is added to g), and the mixture is sufficiently dissolved by stirring at room temperature using a magnetic stirrer or the like. Next, after treating with a membrane filter having a pore size of 0.45 to 0.50 μm, the mixture is injected into GPC. G
As the PC measurement conditions, the column was stabilized at 40 ° C., THF was flowed at a flow rate of 1 cc per minute, and about 100 μl of a 1 mg / cc concentration sample was injected for measurement. The column is preferably used in combination with a commercially available polystyrene gel column. For example, Showa Denko Sho
dex GPC KF-801,802,803,80
4,805,806,807 and TSKgelG1000H, G2000H, G3000 manufactured by Tosoh Corporation
H, G4000H, G5000H, G6000H, G7
000H, TSKguardcolumn, and the like. It is preferable to use a refractive index detector (IR detector) or a UV detector as the detector. In the measurement of the molecular weight of a sample, the molecular weight distribution of the sample is calculated using a calibration curve measured using monodisperse polystyrene standard particles. It is preferable to use about 10 polystyrenes for the calibration curve measurement.

As the polymerizable monomer for obtaining the resin constituting the toner of the present invention (the resin constituting the resin particles (A) and the resin particles (B)), a radical polymerizable monomer is essential. As a component, a crosslinking agent can be used as needed. Further, "radical polymerizable monomer having an acidic group" and "radical polymerizable monomer having a basic group"
It is preferable to use at least one kind of monomer selected from

(1) Radical polymerizable monomer: The radical polymerizable monomer is not particularly limited, and one or two types of conventionally known monomers may be used depending on required characteristics.
More than one species can be used in combination. As such a radical polymerizable monomer, an aromatic vinyl monomer,
(Meth) acrylate monomers, vinyl ester monomers, vinyl ether monomers, monoolefin monomers, diolefin monomers, halogenated olefin monomers, and the like. it can.

Examples of the aromatic vinyl monomer include styrene, o-methylstyrene, m-methylstyrene and p-methylstyrene.
-Methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, p-ethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octyl Styrene monomers such as styrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, 2,4-dimethylstyrene, and 3,4-dichlorostyrene, and derivatives thereof.

Examples of (meth) acrylate monomers include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, and methacrylic acid. Examples include ethyl, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate.

Examples of the vinyl ester monomer include vinyl acetate, vinyl propionate, vinyl benzoate and the like.

Examples of the vinyl ether monomer include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether and the like.

Examples of the monoolefinic monomer include ethylene, propylene, isobutylene, 1-butene,
-Pentene, 4-methyl-1-pentene and the like.

Examples of the diolefin-based monomer include butadiene, isoprene, chloroprene and the like.

Examples of the halogenated olefin monomer include:
For example, vinyl chloride, vinylidene chloride, vinyl bromide and the like can be mentioned.

(2) Crosslinking agent: As a crosslinking agent for improving the properties of the toner, a radical polymerizable crosslinking agent may be added. Examples of such a radical polymerizable crosslinking agent include compounds having two or more unsaturated bonds such as divinylbenzene, divinylnaphthalene, divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, and diallyl phthalate. The ratio of the radical polymerizable crosslinking agent in the monomer (monomer mixture) used is preferably 0.1 to 10% by mass.

(3) Radical polymerizable monomer having an acidic group: Examples of the radical polymerizable monomer having an acidic group include acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, and maleic acid. Acid monobutyl ester,
Carboxylic acid group-containing monomers such as maleic acid monooctyl ester; styrene sulfonic acid, allyl sulfosuccinic acid,
And sulfonic acid group-containing monomers such as octyl allylsulfosuccinate. All or a part of the radical polymerizable monomer having an acidic group may have a structure of an alkali metal salt such as sodium or potassium or an alkaline earth metal salt such as calcium. The ratio of the radical polymerizable monomer having an acidic group in the monomer (monomer mixture) used is preferably 0.1 to 20% by mass,
More preferably, it is 0.1 to 15% by mass.

(4) Radical polymerizable monomer having a basic group: Examples of the radical polymerizable monomer having a basic group include primary amine, secondary amine, tertiary amine, and quaternary amine.
And amine compounds such as quaternary ammonium salts. Specific examples of such an amine compound include dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and quaternary ammonium salts thereof, 3-dimethylaminophenyl acrylate, 2-hydroxy-3- Methacryloxypropyltrimethylammonium salt, acrylamide, N-
Butylacrylamide, N, N-dibutylacrylamide, piperidylacrylamide, methacrylamide, N
-Butylmethacrylamide, N-octadecylacrylamide; vinylpyridine, vinylpyrrolidone; vinyl N
-Methylpyridinium chloride, vinyl N-ethylpyridinium chloride, N, N-diallylmethylammonium chloride, N, N-diallylethylammonium chloride and the like. The ratio of the radical polymerizable monomer having a basic group to the monomer (monomer mixture) used is preferably 0.1 to 20% by mass, more preferably 0.1 to 15% by mass. %.

[Chain Transfer Agent] For the purpose of adjusting the molecular weight of the resin constituting the toner of the present invention, a chain transfer agent generally used can be used. The chain transfer agent is not particularly limited, and examples thereof include mercaptans such as octyl mercaptan, dodecyl mercaptan, tert-dodecyl mercaptan, and styrene dimers.

[Polymerization Initiator] The radical polymerization initiator for obtaining the resin constituting the toner of the present invention can be appropriately used as long as it is a water-soluble radical polymerization initiator. Specific examples of the radical polymerization initiator include, for example, persulfates (potassium persulfate, ammonium persulfate, etc.), azo compounds (4,4′-azobis-4-cyanovaleric acid and its salts, 2,2′-azobis ( 2-amidinopropane) salts, etc.), peroxide compounds and the like. Furthermore, the above-mentioned radical polymerization initiator can be combined with a reducing agent, if necessary, to form a redox initiator. By using the redox initiator, the polymerization activity is increased, the polymerization temperature can be lowered, and the polymerization time can be further reduced. The polymerization temperature is not particularly limited as long as it is equal to or higher than the minimum radical generation temperature of the polymerization initiator.
Range. However, by using a polymerization initiator that starts at room temperature such as a combination of hydrogen peroxide and a reducing agent (such as ascorbic acid), polymerization can be performed at room temperature or higher.

[Surfactant] The surfactant used for polymerizing the above-mentioned radical polymerizable monomer is not particularly limited, but a sulfonate (sodium dodecylbenzenesulfonate, arylalkyl Sodium polyether sulfonate), sulfates (sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc.), fatty acid salts (sodium oleate, sodium laurate, sodium caprate, sodium caprylate, caproic acid) Suitable examples include ionic surfactants such as sodium, potassium stearate, calcium oleate, and the like. In addition, polyethylene oxide, polypropylene oxide, a combination of polypropylene oxide and polyethylene oxide, an ester of polyethylene glycol and a higher fatty acid, an alkylphenol polyethylene oxide, an ester of a higher fatty acid and a polyethylene glycol, an ester of a higher fatty acid and a polypropylene oxide, and a sorbitan ester Nonionic surfactants such as can be used. These surfactants are used as emulsifiers at the time of emulsion polymerization, but may be used for other steps or purposes.

[Colorant] Examples of the colorant constituting the toner of the present invention include various inorganic pigments, organic pigments and dyes. Conventionally known inorganic pigments can be used. Although any pigment can be used, suitable inorganic pigments are exemplified below. As the black pigment, for example, carbon black such as furnace black, channel black, acetylene black, thermal black and lamp black, and magnetic powder such as magnetite and ferrite are also used. These inorganic pigments can be used alone or in combination of two or more as desired. The content ratio of the inorganic pigment in the toner of the present invention is preferably 2 to 20 parts by weight, more preferably 3 to 15 parts by weight based on 100 parts by weight of the resin component (polymer). The content ratio of magnetite in the magnetic toner is preferably from 20 to 60% by mass from the viewpoint of exhibiting desired magnetic properties.

As the organic pigment, conventionally known organic pigments can be used. Although any pigment can be used, specific organic pigments are exemplified below. Pigments for magenta or red include C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I. Pigment Red 6, C.I. I.
Pigment Red 7, C.I. I. Pigment Red 15,
C. I. Pigment Red 16, C.I. I. Pigment Red 48: 1, C.I. I. Pigment Red 53: 1,
C. I. Pigment Red 57: 1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 123,
C. I. Pigment Red 139, C.I. I. Pigment red 144, C.I. I. Pigment Red 149, C.I.
I. Pigment Red 166, C.I. I. Pigment Red 177, C.I. I. Pigment Red 178, C.I. I.
Pigment Red 222 and the like. Examples of orange or yellow pigments include C.I. I. Pigment Orange 31, C.I. I. Pigment Orange 43, C.I. I.
Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 15, C.I. I. Pigment Yellow 1
7, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 94, C.I. I. Pigment Yellow 13
8, and the like. Green or cyan pigments include C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 1
5: 3, C.I. I. Pigment Blue 16, C.I. I. Pigment Blue 60, C.I. I. Pigment Green 7 and the like.

As the dye, C.I. I. Solvent Red 1, 49, 52, 58, 63, 11
1, 122, C.I. I. Solvent Yellow 19, 4
4, 77, 79, 81, 82, 93, 9
8, 103, 104, 112, 162, C.I.
I. Solvent Blue 25, 36, 60, 7
0, 93, 95, etc., and mixtures thereof can also be used.

These organic pigments and dyes can be used alone or in combination of two or more as desired.

The content of the colorant in the toner of the present invention is 2 to 20 parts by weight based on 100 parts by weight of the resin component (polymer).
Parts by weight, more preferably 3 to 15 parts by weight.
Parts by weight.

The colorant (colorant particles) constituting the toner of the present invention may be surface-modified. Here, as the surface modifier, conventionally known ones can be used,
Specifically, a silane coupling agent, a titanium coupling agent, an aluminum coupling agent, or the like can be preferably used.

Examples of the silane coupling agent include alkoxysilanes such as methyltrimethoxysilane, phenyltrimethoxysilane, methylphenyldimethoxysilane and diphenyldimethoxysilane, siloxanes such as hexamethyldisiloxane, γ-chloropropyltrimethoxysilane, vinyl Trichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane,
γ-ureidopropyltriethoxysilane and the like.

As the titanium coupling agent, for example,
TTS, 9S, 38S, 41B, 46B, 5B, which are commercially available under the trade name "Plenact" manufactured by Ajinomoto Co.
5, 138S, 238S, etc., commercial products A-
1, B-1, TOT, TST, TAA, TAT, TL
A, TOG, TBSTA, A-10, TBT, B-2,
B-4, B-7, B-10, TBSTA-400, TT
S, TOA-30, TSDMA, TTAB, TTOP and the like. As the aluminum coupling agent,
For example, "Plenact AL-M" manufactured by Ajinomoto Co., Inc., and the like can be mentioned.

The addition amount of these surface modifiers is preferably from 0.01 to 20% by mass, more preferably from 0.1 to 5% by mass, based on the colorant.

Examples of the method for modifying the surface of the colorant particles include a method in which a surface modifier is added to a dispersion of the colorant particles, and the system is heated and reacted. The surface-modified colorant particles are collected by filtration, and are dried after repeated washing and filtration with the same solvent.

<Specific Structure of Toner of the Present Invention> The toner of the present invention is obtained by salting out the surface of colored particles (core particles) obtained by salting out / fusing the resin particles (A) and the colorant particles. / Toner particles having a core-shell structure in which a resin layer (shell) formed by fusing the resin particles (B) by a fusing method is formed.

As the toner of the present invention having a core-shell structure, those shown in the following [I] or [II] are preferable.

[I] High molecular weight resin particles (A), intermediate molecular weight resin particles (A), and low molecular weight resin particles (A)
And the colorant particles are salted out / fused to obtain colored particles (core particles), and the surface of the colored particles (core particles) is subjected to salting out / fusion.
By a fusion method, the resin particles (B) having an intermediate molecular weight and the resin particles (B) having a low molecular weight are fused to form a resin layer (shell).
(Toner particles 1Bk to 11Bk in Examples described later).

[II] The resin particles (A) composed of composite resin particles obtained by multilayering (compositing) a high molecular weight resin, an intermediate molecular weight resin, and a low molecular weight resin, and the colorant particles are subjected to salting-out.
Colored particles (core particles) were obtained by fusing, and an intermediate molecular weight resin and a low molecular weight resin were multilayered (composited) on the surface of the colored particles (core particles) by a salting-out / fusion method. Toner particles obtained by fusing resin particles (B) composed of composite resin particles to form a resin layer (shell) (“toner particles 12Bk” in Examples described later).

By using composite resin particles as the resin particles (A) and the resin particles (B), it is possible to prepare a toner having no variation in the composition and the molecular weight of the constituent resin among the toner particles. It is particularly excellent in anti-winding properties, anti-offset properties, and charging properties.

The glass transition temperature (Tg) of the resin particles (A) constituting the core particles is preferably in the range of 45 to 70 ° C., more preferably 50 to 65 ° C. Also,
The softening point of the resin particles (A) is preferably in the range of 100 to 140C. Further, the weight average particle size of the resin particles (A) is preferably in the range of 50 to 500 nm.

The glass transition temperature (Tg) of the resin particles (B) constituting the shell is preferably in the range of 45 to 70 ° C., more preferably 50 to 65 ° C. The softening point of the resin particles (B) is preferably in the range of 100 to 140 ° C. The weight average particle size of the resin particles (B) is preferably in the range of 50 to 500 nm.

Here, the glass transition point (Tg) is defined as DS
It refers to the value measured at C, and the intersection of the baseline and the slope of the endothermic peak is taken as the glass transition point. Specifically, using a differential scanning calorimeter, the temperature is raised to 100 ° C., left at that temperature for 3 minutes, and then cooled to room temperature at a temperature drop of 10 ° C./min. Next, this sample was heated at a rate of 10 ° C./m.
When measured in, the intersection of the extension of the base line below the glass transition point and the tangent line indicating the maximum slope from the peak rising part to the peak apex is shown as the glass transition point. As a measuring device, DSC-7 manufactured by Perkin-Elmer can be used.

The softening point is a value measured using a Koka type flow tester. Specifically, using a Koka type flow tester “CFT-500” (manufactured by Shimadzu Corporation), the diameter of the pores of the die is 1 mm, the length is 1 mm, and the load is 20 k.
g / cm ² , and 1 cm ³ under the conditions of a heating rate of 6 ° C./min.
The temperature corresponding to 1/2 of the height from the outflow start point to the outflow end point when the sample is melted and discharged is indicated as the softening point.

Weight average particle size of resin particles (dispersion particle size)
Is an electrophoretic light scattering photometer ELS-80 manufactured by Otsuka Electronics Co., Ltd.
This is a value measured using 0.

The toner particles constituting the toner of the present invention may contain a release agent. Here, examples of the release agent include various known ones which can be dispersed in water. Specific examples include olefin waxes such as polypropylene and polyethylene, modified products of these olefin waxes, natural waxes such as carnauba wax and rice wax, and amide waxes such as fatty acid bisamide.

As a preferred release agent constituting the toner of the present invention, a release agent composed of a crystalline ester compound represented by the following general formula (1) (hereinafter, referred to as “specific ester compound”) may be mentioned. it can.

[0071]

Embedded image General formula (1): R ¹ — (OCO—R ² ) _n

(In the formula, R ¹ and R ² each represent a hydrocarbon group which may have a substituent and has 1 to 40 carbon atoms, and n is an integer of 1 to 4.)

Formula (1) representing a specific ester compound
In the above, R ¹ and R ² each represent a hydrocarbon group which may have a substituent. The number of carbon atoms in the hydrocarbon radical R ¹ is 1 to 40, preferably 1 to 20, more preferably 2 to 5. Number of carbon atoms in the hydrocarbon group R ² is 1-4
0, preferably 16 to 30, more preferably 18
To 26. In the general formula (1), n is 1
And is preferably an integer of 2 to 4, preferably 2 to 4, more preferably 3 to 4, and particularly preferably 4. The specific ester compound can be suitably synthesized by a dehydration condensation reaction between an alcohol and a carboxylic acid.

Specific examples of the specific ester compound include:
Compounds represented by the following formulas 1) to 22) can be exemplified.

[0075]

Embedded image

[0076]

Embedded image

The method for incorporating the release agent into the toner particles is as follows: (1) In the step of forming colored particles (core particles), a dispersion (wax emulsion) of release agent particles is added, and the resin particles (A ), The colorant particles and the release agent particles, and (2) in the step of forming the color particles (core particles), the release agent-containing resin particles (A) and the colorant particles (3) In the step of forming the resin layer (shell), a dispersion liquid (wax emulsion) of release agent particles is added, and the resin particles (B) and the release agent particles are salted. (4) In the step of forming the resin layer (shell), a method of salting out / fusing the resin particles (B) containing the release agent can be mentioned. The method (4) may be combined.

The content ratio of the release agent in the toner particles is usually from 1 to 30% by mass, preferably from 2 to 2% by mass.
0 mass%, more preferably 3 to 15 mass%.

The toner particles constituting the toner of the present invention may contain various internal additives such as a charge control agent. As the charge control agent contained in the toner particles,
Nigrosine dyes, metal salts of naphthenic acid or higher fatty acids, alkoxylated amines, quaternary ammonium salt compounds, azo metal complexes, salicylic acid metal salts or metal complexes thereof. Methods for incorporating an internal additive such as a charge control agent into toner particles include the methods described in (1) to (1) above.
A method similar to the method of including the release agent shown in (4) can be exemplified.

<Diameter of Toner Particles> The toner of the present invention preferably has a volume average particle diameter of 3 to 9 μm, more preferably 3 to 8 μm. This particle size is
In the method for producing a toner described in detail below, the concentration can be controlled by the concentration of the coagulant (salting agent), the amount of the organic solvent added, the fusing time, and the composition of the polymer. Volume average particle size is 3 ~
When the thickness is 9 μm, in the fixing step, toner particles having a large adhesive force that fly and adhere to the heating member to generate an offset are reduced, and the transfer efficiency is increased to improve the halftone image quality. The image quality of dots and the like is improved.

The volume average particle diameter of the toner is measured with a Coulter Counter TA-II or a Coulter Multisizer (manufactured by Coulter Inc.). In the present invention, an interface (manufactured by Nikkaki) for outputting a particle size distribution and a personal computer were used by using a Coulter Multisizer. The particle size distribution and the average particle size were calculated by measuring the volume distribution of toner having a size of 2 μm or more (for example, 2 to 40 μm) using an aperture of 100 μm in the Coulter Multisizer.

[Measurement Conditions] (1) Aperture: 100 μm (2) Sample preparation method: Electrolyte [ISOTON R-1
1 (manufactured by Coulter Scientific Japan)
An appropriate amount of a surfactant (neutral detergent) is added to 50 to 100 ml, and the mixture is stirred, and 10 to 20 mg of a measurement sample is added thereto. This system is prepared by subjecting it to a dispersion treatment with an ultrasonic disperser for 1 minute.

Further, the toner of the present invention has a thickness of 3 μm
The ratio of the following toner particles is preferably 20% by number or less, and the ratio of the toner particles of 2 μm or less is 10% by number.
It is more preferred that: The amount of such toner particles (fine powder toner) can be measured using an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd.
In order to adjust the particle size distribution in this way, it is preferable to narrow the temperature control in the salting out / fusion step. Specifically, it means raising the temperature as quickly as possible, that is, increasing the heating rate. As this condition, the time until the temperature rise is less than 30 minutes, preferably less than 10 minutes, and the rate of temperature rise is preferably 1 to 15 ° C./min.

<Shape of Toner Particle> The shape of the toner particles constituting the toner of the present invention has an average circularity (average circularity represented by the following formula) of 0.930 to 0.980.
And more preferably 0.940 to
0.975.

[0085]

## EQU1 ## Circularity = (circumferential length of circle obtained from circle equivalent diameter) /
(Perimeter of particle projection image)

By setting the average circularity to 0.930 to 0.980, the shape of the toner can be made somewhat irregular, the heat transfer can be made more efficient, and the fixability can be further improved. be able to. That is, the fixing property can be improved by setting the average circularity to 0.980 or less. Further, by setting the average circularity to 0.930 or more, the degree of irregularity of the particles can be suppressed, and the friability of the particles due to stress during long-term use can be suppressed.

The circularity distribution is preferably sharp, the standard deviation of the circularity is preferably 0.10 or less, and the CV value calculated by the following equation is preferably less than 20%. , More preferably less than 10%.

[0088]

CV value = (standard deviation of circularity / average circularity) × 100

By setting the standard deviation of the circularity to 0.10 or less, a toner having a uniform shape can be obtained, and a difference in fixing performance between toners can be reduced. The effect of preventing the fixing device from being contaminated by reducing the offset resistance is more exhibited. Further, when the CV value is less than 20%, a sharp shape distribution can be similarly obtained, and the effect of improving fixability can be more remarkably exhibited. The method for measuring the average circularity is not limited. For example, a photograph in which toner particles are magnified 500 times with an electron microscope is taken, and the circularity is measured for 500 or more toners using an image analyzer. By calculating the arithmetic average value, the average circularity can be calculated. As a simple measurement method, “FPIA-1000” is used.
(Manufactured by Toa Medical Electronics Co., Ltd.).

As a method for controlling the circularity of the toner particles, in the salting-out / fusion step (the step of forming a resin layer on the surface of the colored particles), the shape and particle diameter of the fused particles (toner particles) are monitored. To determine an appropriate process end time. Specifically, a circularity measuring device is incorporated in-line, and in the salting-out / fusion step, the fused particles are sampled to measure the circularity and particle size, and the desired shape and particle size are obtained. At this point, the fusion reaction is stopped.

Although the monitoring method is not particularly limited, a flow type particle image analyzer “FPIA” is used.
-2000 "(manufactured by Toa Medical Electronics Co., Ltd.). This apparatus can monitor the shape of the fused particles by performing image processing in real time while passing the sample liquid (dispersed liquid of the fused particles). That is, using a pump etc. from the reaction field, constantly monitoring,
The shape is measured, and the reaction is stopped when the desired shape is obtained.

(External Additives) The toner particles described above can constitute the toner of the present invention as it is.
In order to improve the charging property, the cleaning property, and the like, the toner of the present invention may be constituted by adding a so-called external additive to the toner particles. Such external additives are not particularly limited, and include various inorganic fine particles, organic fine particles, and lubricants.

As the inorganic fine particles that can be used as an external additive, conventionally known inorganic fine particles can be exemplified. Specifically, silica fine particles, titanium fine particles, alumina fine particles and the like can be preferably used.

Specific examples of the silica fine particles include commercially available products R-805, R-976, and R-980 manufactured by Nippon Aerosil Co., Ltd.
974, R-972, R-812, R-809, HVK-2150 and H-200 manufactured by Hoechst Co., Ltd., and commercial products TS-720, TS-530, TS manufactured by Cabot Co., Ltd.
-610, H-5, MS-5 and the like.

Specific examples of the titanium fine particles include, for example,
Commercial products T-805 and T-60 manufactured by Nippon Aerosil Co., Ltd.
4. Commercial products MT-100S and MT-1 manufactured by Teika Co., Ltd.
00B, MT-500BS, MT-600, MT-60
0SS, JA-1, commercial product TA- manufactured by Fuji Titanium Co., Ltd.
300SI, TA-500, TAF-130, TAF-
510, TAF-510T, and commercial products IT-S, IT-OA, IT-OB, IT-OC manufactured by Idemitsu Kosan Co., Ltd.

Specific examples of the alumina fine particles include, for example, commercial products RFY-C and C-C manufactured by Nippon Aerosil Co., Ltd.
604, a commercial product TTO-55 manufactured by Ishihara Sangyo Co., Ltd., and the like.

It is preferable that these inorganic fine particles have been subjected to a hydrophobic treatment with a silane coupling agent, a titanium coupling agent or the like. The degree of the hydrophobic treatment is not particularly limited, but a methanol wettability of 40 to 95 is preferable. Methanol wettability is to evaluate the wettability to methanol. In this method, 0.2 g of the inorganic fine particles to be measured is weighed and added to 50 ml of distilled water placed in a 200 ml beaker. Methanol is slowly dropped from a burette whose tip is immersed in the liquid until the entire inorganic fine particles are wet with slow stirring.
When the amount of methanol required to completely wet the inorganic fine particles is a (ml), the degree of hydrophobicity is calculated by the following equation.

[0098]

(Equation 3)

Examples of the organic fine particles that can be used as the external additive include spherical fine particles having a number average primary particle diameter of about 10 to 2000 nm. Examples of the constituent material of the organic fine particles include polystyrene, polymethyl methacrylate, and styrene-methyl methacrylate copolymer.

Examples of the lubricant that can be used as an external additive include metal salts of higher fatty acids. Specific examples of such metal salts of higher fatty acids include metal stearate salts such as zinc stearate, aluminum stearate, copper stearate, magnesium stearate, and calcium stearate; zinc oleate, manganese oleate, iron oleate, and olein. Metal salts of oleic acid such as copper phosphate and magnesium oleate; Metal salts of palmitic acid such as zinc palmitate, copper palmitate, magnesium palmitate and calcium palmitate; Metal salts of linoleic acid such as zinc linoleate and calcium linoleate; Ricinol And metal salts of ricinoleic acid such as zinc acid and calcium ricinoleate.

The addition amount of the external additive is preferably about 0.1 to 5% by mass, more preferably 0.5 to 4% by mass, based on the toner particles.

<Production Method of the Present Invention> The production method of the present invention comprises a step of forming a resin layer (shell) by fusing resin particles to the surface of colored particles (core particles) by salting out / fusion. It has a feature in including. More specifically, a step of salting out / fusing the resin particles (A) and the colorant particles to form colored particles (core particles); Fusing the resin particles (B) by fusion to form a resin layer (shell).

As an example of the production method of the present invention, (1)
A polymerization step for preparing the resin particles (A), (2) a polymerization step for preparing the resin particles (B), and (3) salting out the resin particles (A) and the colorant particles in an aqueous medium. (4) salting out / fusing step of fusing to obtain colored particles (core particles), (4) salting out resin particles (B) on the surface of colored particles (core particles) /
A salting-out / fusing step of forming a resin layer (shell) by fusing to obtain toner particles having a core-shell structure;
(5) a filtration / washing step of filtering the toner particles from a dispersion system (aqueous medium) of the toner particles and removing a surfactant or the like from the toner particles; and (6) drying of the washed toner particles. And (7) a step of adding an external additive to the dried toner particles.

Hereinafter, each step will be described. [Polymerization Step for Preparing Resin Particles (A)] In this polymerization step, basically, a conventionally known polymerization method (emulsion polymerization method,
Suspension polymerization method). As an example of the polymerization method, a radical polymerization initiator is dissolved in an aqueous medium (aqueous solution of a surfactant) and heated, and when a predetermined temperature (polymerization temperature) is reached, a radical polymerizable monomer (monomeric The mixture is heated under stirring, usually under a nitrogen atmosphere. Here, in the monomer mixture,
When at least one of the radical polymerizable monomer having an acidic group and the radical polymerizable monomer having a basic group is 0.1
It is preferably contained in a proportion of up to 20% by mass.
The polymerization temperature and the polymerization time can be appropriately set within a range where the polymerization reaction occurs. The molecular weight of the resin particles (A) is
It can be adjusted by the amount of the polymerization initiator, the reaction temperature, and the addition of the chain transfer agent. When a chain transfer agent is used to adjust the molecular weight of the resin, it is preferable to add the chain transfer agent by mixing it with a radically polymerizable monomer. The particle size of the resin particles (A) thus obtained is preferably in the range of 50 to 500 nm in weight average particle size.

As a preferred method for producing the resin particles (A) having a molecular weight distribution of two or more peaks, resin particles are prepared according to a conventional method such as an emulsion polymerization method, and a radical polymerizable liquid is added to a dispersion liquid of the resin particles. A method of adding a monomer and performing polymerization to form a multilayer (composite) can be given.

More specifically, the resin particles (A)
In order to produce composite resin particles in which a high molecular weight resin, an intermediate molecular weight resin, and a low molecular weight resin are multilayered (composite), a high-molecular weight resin prepared by a polymerization treatment (first-stage polymerization) according to a conventional method is used. A polymerization initiator and a monomer mixture (a polymerizable monomer for obtaining an intermediate molecular weight resin) are added to a dispersion of resin particles composed of a molecular weight resin, and this system is subjected to a polymerization treatment (second stage polymerization). Then, a polymerization initiator and a monomer mixture (a polymerizable monomer for obtaining a low-molecular-weight resin) are added to a dispersion of the obtained composite resin particles (high-molecular-weight resin-intermediate-molecular-weight resin), A method of subjecting this system to a polymerization treatment (third stage polymerization) can be employed.

As a method for producing a resin particle containing a release agent as the resin particle (A), a release agent is dissolved in a monomer, and the obtained monomer solution is dispersed in an aqueous medium. Alternatively, a method of subjecting this system to a polymerization treatment to obtain latex particles can be employed. The resin particles (A) containing the release agent thus obtained preferably have a weight average particle size of 50 to 2000 nm.

Here, the “aqueous medium” refers to water 50 to 10
A medium consisting of 0% by mass and 0 to 50% by mass of a water-soluble organic solvent. Examples of the water-soluble organic solvent include methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran, and an alcohol-based organic solvent that does not dissolve the obtained resin is preferable.

As a preferred polymerization method for obtaining resin particles containing a release agent, a release agent is contained in a monomer in an aqueous medium in which a surfactant having a concentration equal to or lower than the critical micelle concentration is dissolved. A method of preparing a dispersion by dispersing the dissolved monomer solution in oil droplets using mechanical energy, adding a water-soluble polymerization initiator to the obtained dispersion, and subjecting the resulting dispersion to radical polymerization (hereinafter referred to as a radical polymerization). In this specification, "mini-emulsion method"
That. ). Instead of adding the water-soluble polymerization initiator, or together with the addition of the water-soluble polymerization initiator, an oil-soluble polymerization initiator may be added to the monomer solution.

Here, the disperser for performing oil droplet dispersion by mechanical energy is not particularly limited, and a stirrer “CLEARMIX” (M Technic) equipped with a high-speed rotating rotor (Trade name), an ultrasonic disperser, a mechanical homogenizer, a Menton-Gaulin and a pressure homogenizer. Further, the dispersed particle diameter is 10 to 1
000 nm, preferably 30 to 300 nm.

[Polymerization Step for Preparing Resin Particles (B)] In the polymerization step, similarly to the polymerization step for preparing the resin particles (A), conventionally known polymerization methods (emulsion polymerization method, suspension polymerization method, Polymerization method).

The particle size of the resin particles (B) constituting the shell is preferably in the range of 50 to 500 nm in weight average particle size.

As a method for producing resin particles (B) having a molecular weight distribution of two or more peaks, resin particles are prepared according to a conventional method such as an emulsion polymerization method, and a radical polymerizable monomer is added to a dispersion liquid of the resin particles. A method of forming a multilayer (composite) by adding an additional body and performing polymerization can be given.

More specifically, the resin particles (B)
In order to produce composite resin particles in which an intermediate molecular weight resin and a low molecular weight resin are multi-layered (composite), it is necessary to use an intermediate molecular weight resin prepared by a polymerization treatment (first-stage polymerization) according to a conventional method. In a dispersion of resin particles, a polymerization initiator and a monomer mixture (polymerizable monomer for obtaining a low molecular weight resin)
And a method of subjecting this system to a polymerization treatment (second-stage polymerization).

The resin particles (B) containing the release agent can be obtained by the same method (preferably the mini-emulsion method) as the method for obtaining the resin particles (A) containing the release agent. .

[Salt-out / fusion step for obtaining colored particles (core particles)] In the salt-out / fusion step, the resin particles (A) and the colorant particles are salted out / fused in an aqueous medium. This is a step of obtaining irregular (non-spherical) colored particles by causing the particles to undergo salting-out and fusion simultaneously. In this step, together with the resin particles (A) and the colorant particles, internal additive particles (particles having a number average primary particle diameter of about 50 to 500 nm) such as a release agent and a charge control agent are salted out / fused. You may.

The colorant particles may be surface-modified. Here, conventionally known surface modifiers can be used. The colorant particles are subjected to a salting-out / fusion process in a state of being dispersed in an aqueous medium. Examples of the aqueous medium in which the colorant particles are dispersed include an aqueous solution in which a surfactant is dissolved at a concentration equal to or higher than the critical micelle concentration (CMC). Here, as the surfactant, the surfactant used as an emulsifier in the polymerization step can be used. The disperser used for the dispersion treatment of the colorant particles is not particularly limited, but is preferably a stirrer “CLEARMIX” equipped with a high-speed rotating rotor.
(Manufactured by M Technique Co., Ltd.), an ultrasonic disperser, a mechanical disperser such as a mechanical homogenizer, a Menton-Gaulin, a pressure disperser such as a pressure homogenizer, and a medium disperser such as a Getzman mill or a diamond fine mill.

In order to carry out salting-out / fusion of the resin particles (A) and the colorant particles, the salting-out of the resin particles (A) and the colorant particles in a dispersion liquid having a critical aggregation concentration or more is carried out. It is necessary to add an agent (aggregating agent) and to heat the dispersion to a temperature equal to or higher than the glass transition temperature (Tg) of the resin particles (A).

The preferred temperature range for salting out / fusing is (Tg + 10) to (Tg + 50 ° C.), and particularly preferably (Tg + 15) to (Tg + 40 ° C.). Further, in order to effectively perform the fusion, an organic solvent that is infinitely soluble in water may be added to substantially lower the glass transition temperature (Tg) of the resin particles.

Here, examples of the “salting agent” used for salting out / fusing include alkali metal salts and alkaline earth metal salts. Examples of the alkali metal constituting the salting-out agent include lithium, potassium, sodium and the like, and examples of the alkaline earth metal constituting the salting-out agent include magnesium, calcium, strontium, barium and the like. Of these, potassium, sodium, magnesium, calcium, and barium are preferred.
Examples of the counter ion (anion constituting a salt) of the alkali metal or alkaline earth metal include a chloride ion, a bromide ion, an iodide ion, a carbonate ion, and a sulfate ion.

Examples of “organic solvents that are infinitely soluble in water” that can be added during salting out / fusion include methanol,
Examples include ethanol, 1-propanol, 2-propanol, ethylene glycol, glycerin, acetone and the like. Of these, alcohols having 3 or less carbon atoms, such as methanol, ethanol, 1-propanol and 2-propanol, are preferred, and 2-propanol is particularly preferred.

When the salting-out agent is added to the dispersion in which the resin particles (A) and the colorant particles are dispersed, the temperature of the dispersion is determined by the glass transition temperature (Tg) of the resin particles (A).
Or less, specifically, preferably in the range of 5 to 55 ° C, more preferably 10 to 45 ° C.
° C. When the temperature of the dispersion when adding the salting-out agent,
When the temperature is equal to or higher than the glass transition temperature (Tg) of the resin particles (A), it is difficult to control the particle size, and large particles are easily generated.

As described above, in the salting-out / fusion step, when the temperature of the dispersion of the resin particles (A) and the colorant particles is lower than the glass transition temperature (Tg) of the resin particles (A). It is necessary to add a salting-out agent to the dispersion and then immediately start heating the dispersion to make the temperature equal to or higher than the glass transition temperature (Tg) of the resin particles (A).

In order to carry out salting out / fusion, that is, to cause salting out and fusion at the same time, a salting out agent is added to the dispersion in which the resin particles (A) and the colorant particles are dispersed. Thereafter, the interval until the temperature of the dispersion reaches the temperature (the temperature at which fusion can be performed) equal to or higher than the glass transition temperature (Tg) of the resin particles (A) is usually within 120 minutes, and preferably 90 minutes. Within minutes. This interval is 12
When the time exceeds 0 minutes, the aggregation state of the aggregated particles (non-fused particles) due to salting out fluctuates, and the particle size distribution of the colored particles obtained by fusing the particles becomes broad, And the surface properties of the toner particles are changed.

The interval from the addition of the salting-out agent to the dispersion to the start of the heating of the dispersion is as follows:
It is usually within 30 minutes, preferably within 15 minutes, more preferably within 10 minutes. The rate of temperature rise of the dispersion after the addition of the salting-out agent is 0.25 to 15 ° C./min.
And more preferably 1 to 15 ° C./m
in. If the heating rate is too low, it takes a long time to reach the glass transition temperature (Tg) or more,
Salting out and fusion cannot be performed simultaneously. on the other hand,
If the heating rate is too high, it is difficult to control the particle size, and large particles are likely to be generated.

The particle diameter of the colored particles (core particles) obtained as described above is preferably in the range of 2 to 9 μm in terms of volume average particle diameter.

The average circularity of the colored particles (core particles) is preferably from 0.850 to 0.950, and more preferably from 0.860 to 0.940.

If the average circularity of the colored particles is less than 0.850 (the degree of irregularity is excessive), it becomes difficult to form a uniform resin layer (shell) on the surface of the colored particles. On the other hand, the average circularity of the colored particles is 0.950.
When the average particle size exceeds 0.980, the average circularity of the finally obtained toner particles exceeds 0.980, and the fixability may be impaired.

[Salt-out / fusion step for obtaining toner particles (core-shell particles)] In the salt-out / fusion step, the surface of the colored particles (core particles) obtained in the above-mentioned step is coated with a resin. This is a step of forming the resin layer (shell) by fusing the particles (B) by salting out / fusing to obtain amorphous toner particles having a core-shell structure. The salting-out / fusion step is performed by (i) adhering the resin particles (B) to the surfaces of the colored particles (core particles) to grow the particles, and (ii) heating the particles after stopping the particle growth. An aging step of forming a film and controlling the shape of the particles.

In order to fuse the resin particles (B) to the surface of the colored particles (core particles) by salting out / fusing, the resin particles (B) are continuously subjected to the salting out / fusing step for obtaining the colored particles. It is preferable to perform a step (shell forming step). That is, the dispersion liquid of the colored particles obtained in the above step [the glass transition temperature (Tg) of the resin constituting the resin particles (B) containing the salting-out agent and, if necessary, an organic solvent infinitely soluble in water, is contained. The dispersion of the resin particles (B) is added to the dispersion of the colored particles maintained at the above temperature, and the temperature is preferably maintained at or above the glass transition temperature (Tg).
The preferred temperature range for salting out / fusing is (T
g + 10) to (Tg + 50 ° C.), particularly preferably (Tg + 15) to (Tg + 40 ° C.).

The addition amount of the dispersion of the resin particles (B) is such that the resin particles (B) are 1 to 30% by mass of the toner particles.
It is preferable that the amount is such that

The shape of the core-shell structured toner particles obtained as described above (preferably average circularity = 0.9)
30 to 0.980) are the shapes (preferably average circularity = 0.850 to 0.950) of the colored particles as the core particles,
It can be controlled by adjusting the heating conditions in the aging stage of the salting-out / fusion process.

[Filtration / Washing Step] In this filtration / washing step, a filtration treatment for filtering the toner particles from the dispersion system of the toner particles obtained in the above step, Washing treatment for removing extraneous substances such as surfactants and salting-out agents from the aggregates). Here, the filtration method is not particularly limited, such as a centrifugal separation method, a vacuum filtration method using a Nutsche method, a filtration method using a filter press, or the like.

[Drying Step] This step is a step of drying the washed toner particles. Dryers used in this step include spray dryers, vacuum freeze dryers, vacuum dryers and the like, stationary shelf dryers, mobile shelf dryers, fluidized bed dryers, rotary dryers ,
It is preferable to use a stirring dryer or the like. The moisture content of the dried toner particles is preferably 5% by mass or less, more preferably 2% by mass or less.

Incidentally, the dried toner particles are
In the case where the aggregates are aggregated by a weak attraction between particles, the aggregates may be crushed. Here, as the crushing device,
A mechanical pulverizer such as a jet mill, a Henschel mixer, a coffee mill, and a food processor can be used.

[Step of Adding External Additive] This step is a step of adding an external additive to the dried toner particles. Examples of a device used for adding the external additive include various known mixing devices such as a turbular mixer, a Hensiel mixer, a Nauter mixer, and a V-type mixer.

[Developer] The toner of the present invention can be used as a magnetic or non-magnetic one-component developer.
It may be used as a two-component developer by mixing with a carrier. When the toner of the present invention is used as a two-component developer, as the carrier, a conventionally known material such as iron, ferrite, a metal such as magnetite, or an alloy of such a metal with aluminum or a metal such as lead is used. be able to. Particularly, ferrite particles are preferable. The volume average particle size of the carrier is preferably from 15 to 100 μm, more preferably from 25 to 60 μm. The volume average particle size of the carrier is typically measured by a laser diffraction type particle size distribution analyzer “HELOS” equipped with a wet disperser.
(Manufactured by SYMPATEC).

Preferred carriers include a resin-coated carrier in which the surface of magnetic particles is coated with a resin, and a so-called resin-dispersed carrier in which magnetic particles are dispersed in a resin. The resin constituting the resin-coated carrier is not particularly limited, and examples thereof include an olefin resin, a styrene resin, a styrene / acrylic resin, a silicone resin, an ester resin, and a fluorine-containing polymer resin. The resin constituting the resin-dispersed carrier is not particularly limited, and a known resin can be used. For example, styrene acrylic resin, polyester resin, fluorine resin, phenol resin and the like can be used.

(Fixing Process / Conditions) The toner of the present invention has a fixing step by a contact heating method, that is, an image including a step of bringing a toner image transferred to an image support into contact with a heating member such as a hot roll to fix the toner image. It can be suitably used for the forming method (the image forming method of the present invention). Examples of the contact heating method include a heat and pressure fixing method, in particular, a hot roll fixing method and a pressure heat fixing method in which fixing is performed by a rotating pressing member including a fixedly disposed heating element.

Here, in the heat roll fixing method, a heat source is provided inside a metal cylinder made of iron, aluminum, or the like whose surface is coated with tetrafluoroethylene, polytetrafluoroethylene-perfluoroalkoxyvinyl ether copolymer, or the like. Formed from an upper roller and a lower roller formed of silicone rubber or the like. More specifically, it has a linear heater as a heat source and heats the surface temperature of the upper roller to about 120 to 200 ° C. In the fixing section, a pressure is applied between the upper roller and the lower roller to deform the lower roller to form a so-called nip.
The nip width is 1 to 10 mm, preferably 1.5 to 7
mm. The fixing linear velocity is preferably 40 to 600 mm / sec. When the nip is narrow, heat cannot be uniformly applied to the toner, causing uneven fixing. On the other hand, if the nip width is wide, the melting of the resin is promoted, and a problem occurs in that the fixing offset becomes excessive.

If necessary, a fixing cleaning mechanism may be provided. In this case, a method of supplying the silicone oil to the upper roller or the film of the fixing or a method of cleaning with a pad, roller, web or the like impregnated with the silicone oil can be used. As the silicone oil, those having high heat resistance are used, such as polydimethylsiloxane, polymethylphenylsiloxane, polydiphenylsiloxane, and polysiloxane containing fluorine. Since those having low viscosity have a large outflow during use, the viscosity at 20 ° C. is 1,000 to 100,0.
The one with 00 cp is preferably used.

[0142]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples.

[Preparation Example HP-1] In a 5000 ml separable flask equipped with a stirrer, a temperature sensor, a condenser, and a nitrogen introducing device, 7.08 g of an anionic surfactant (sodium dodecyl sulfonate: SDS) was ionized. A surfactant solution (aqueous medium) dissolved in 2760 g of exchanged water was charged, and the internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm in a nitrogen stream. A polymerization initiator (potassium persulfate: KPS) is added to this surfactant solution.
An initiator solution obtained by dissolving 0.45 g in 200 g of ion-exchanged water was added, and the temperature was adjusted to 75 ° C.
A monomer mixture consisting of 5.1 g, 42.0 g of n-butyl acrylate and 10.9 g of methacrylic acid was added dropwise over 1 hour, and the system was heated and stirred at 75 ° C. for 2 hours to give a latex ( A dispersion of high molecular weight resin particles was prepared. This is designated as "latex (HP-1)". The weight average molecular weight (Mw) of the resin particles constituting the latex (HP-1) was 318,000.
The weight average particle size of the resin particles was 105 nm.

[Preparation Example HP-2] A latex (dispersion liquid of high molecular weight resin particles) was prepared in the same manner as in Preparation Example HP-1 except that the reaction temperature was changed to 85 ° C. This is designated as "latex (HP-2)". The weight average molecular weight (M) of the resin particles constituting the latex (HP-2)
w) was 235,000. The weight average particle size of the resin particles was 106 nm.

[Preparation Example HP-3] Polymerization initiator (KPS)
Preparation Example HP except that the amount of
A latex (dispersion liquid of resin particles of high molecular weight) was prepared in the same manner as -1. This is called "latex (HP-3)"
And The weight average molecular weight (Mw) of the resin particles constituting the latex (HP-3) was 262,000. The weight average particle size of the resin particles was 110 nm.

[Preparation Example HP-4] Potassium persulfate (KP
The amount of S) was changed to 0.90 g, and the reaction temperature was increased to 90 ° C.
A latex (dispersion liquid of high molecular weight resin particles) was prepared in the same manner as in Preparation Example HP-1, except that the composition was changed to the following. This is designated as "latex (HP-4)". The weight average molecular weight (Mw) of the resin particles constituting the latex (HP-4) was 195,000. The weight average particle size of the resin particles was 110 nm.

[Preparation Example MP-1] In a flask equipped with a stirrer, a compound represented by the above formula (19)
It is referred to as "exemplary compound (19)." ) 72.0 g, styrene 383.6 g, n-butyl acrylate 140.0
g, 36.4 g of methacrylic acid and 5.6 g of dodecyl mercaptan, and the mixture was heated to 80 ° C. and dissolved to prepare a monomer solution. Meanwhile, a stirrer,
500 equipped with temperature sensor, cooling pipe and nitrogen inlet pipe
A 0 ml separable flask was charged with a surfactant solution (aqueous medium) in which 1.6 g of an anionic surfactant (SDS) was dissolved in 2000 g of ion-exchanged water.
The temperature was raised to ° C. Next, the monomer solution (80 ° C.) is mixed and dispersed in the surfactant solution (80 ° C.) by a mechanical disperser “CLEARMIX” (manufactured by M Technique Co., Ltd.) having a circulation path. A dispersion liquid of emulsified particles (oil droplets) having a uniform dispersed particle diameter was prepared. Next, to this dispersion, an initiator solution obtained by dissolving 19.1 g of a polymerization initiator (KPS) in 240 g of ion-exchanged water and 750 g of ion-exchanged water are added, and the system is heated at 80 ° C. for 3 hours. -Polymerization was carried out by stirring to prepare a latex (a dispersion of resin particles having an intermediate molecular weight and containing the exemplified compound (19)). This is called "latex (MP-
1) ". The weight average molecular weight (Mw) of the resin particles constituting the latex (MP-1) was 93,000. The weight average particle diameter of the resin particles is 105 nm.
Met.

[Preparation Example MP-2] A latex (exemplified compound (19) was prepared in the same manner as in Preparation Example MP-1 except that the amount of dodecyl mercaptan constituting the monomer mixture was changed to 8.3 g. Containing a dispersion of resin particles having an intermediate molecular weight). This is designated as "latex (MP-2)". The weight average molecular weight (Mw) of the resin particles constituting the latex (MP-2) was 85,000. The weight average particle size of the resin particles was 110 nm.

[Preparation Example MP-3] Latex (exemplary compound (MP) was prepared in the same manner as in Preparation Example MP-1 except that the amount of Exemplified Compound (19) added to the monomer mixture was changed to 144.0 g. (19) A dispersion liquid of intermediate molecular weight resin particles containing (19) was prepared. This is designated as "latex (MP-3)". The weight average molecular weight (Mw) of the resin particles constituting the latex (MP-3) was 93,000. The weight average particle size of the resin particles was 110 nm.

[Preparation Example MP-4] In place of Exemplified Compound (19), 72.0 g of a compound represented by the above formula (21) (hereinafter referred to as “Exemplified Compound (21)”) was mixed with a monomer mixture. Latex (dispersion liquid of intermediate molecular weight resin particles containing Exemplified Compound (21)) was prepared in the same manner as in Preparation Example MP-1 except that it was added. This is designated as "latex (MP-4)". The weight average molecular weight (Mw) of the resin particles constituting the latex (MP-4) is 105,
000. The weight average particle size of the resin particles was 110 nm.

[Preparation Example MP-5] In place of Exemplified Compound (19), 72.0 g of a compound represented by the above formula (18) (hereinafter referred to as “Exemplified Compound (18)”) was mixed with a monomer mixture. Latex (dispersion liquid of resin particles of intermediate molecular weight containing Exemplified Compound (18)) was prepared in the same manner as in Preparation Example MP-1, except that it was added. This is designated as “latex (MP-5)”. The weight average molecular weight (Mw) of the resin particles constituting the latex (MP-5) is 105,
000. The weight average particle diameter of the resin particles was 115 nm.

[Preparation Example LP-1] In a flask equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introduction device, 60 g of an anionic surfactant (SDS) was added with ion-exchanged water 5.
A surfactant solution (aqueous medium) dissolved in 000 g was charged, and the internal temperature was raised to 80 ° C. while stirring at a stirring speed of 230 rpm in a nitrogen stream. To this surfactant solution, 22.8 g of a polymerization initiator (KPS) was added with ion-exchanged water 2
The initiator solution dissolved in 00 g was added and the temperature was raised to 80 ° C.
, 850 g of styrene, 252 g of butyl acrylate, 98 g of methacrylic acid and 32 g of t-dodecyl mercaptan are added dropwise over 1 hour, and the system is heated and stirred at 80 ° C. for 2 hours. Latex (dispersion of low molecular weight resin particles)
Was prepared. This is designated as "latex (LP-1)". The weight average molecular weight (Mw) of the resin particles constituting the latex (LP-1) was 18,000. The weight average particle size of the resin particles was 110 nm.

[Preparation Example HML-1] (1) Preparation of core particles (first stage polymerization): 5000 m equipped with a stirrer, a temperature sensor, a cooling pipe, and a nitrogen introducing device.
1 separable flask was charged with a surfactant solution (aqueous medium) in which 7.08 g of an anionic surfactant (sodium dodecyl sulfonate: SDS) was dissolved in 2760 g of ion-exchanged water, and the stirring speed was 230 rpm under a nitrogen stream. While stirring at, the internal temperature was raised to 80 ° C. A polymerization initiator (potassium persulfate: KP) is added to this surfactant solution.
S) An initiator solution obtained by dissolving 0.42 g in 200 g of ion-exchanged water was added, and the temperature was adjusted to 75 ° C.
A monomer mixture consisting of 15.1 g, n-butyl acrylate 42.0 g, and methacrylic acid 10.9 g was added dropwise over 1 hour, and the system was heated and stirred at 75 ° C. for 2 hours to carry out polymerization ( First stage polymerization) was performed to prepare a latex (a dispersion of resin particles composed of a high molecular weight resin). This is designated as “latex (1H)”.

(2) Formation of Intermediate Layer (Second Stage Polymerization): In a flask equipped with a stirrer, styrene 38 was added.
To a monomer mixture consisting of 3.6 g, 140.0 g of n-butyl acrylate, 36.4 g of methacrylic acid, and 5.6 g of n-octyl-3-mercaptopropionate, 72.0 g of Exemplified Compound (19) was added. At 80 ° C. and dissolved to prepare a monomer solution. On the other hand, 1.6 g of anionic surfactant (SDS) was added to 2000 m of ion-exchanged water.
The surfactant solution dissolved in the above solution was heated to 80 ° C., and the surfactant solution was added to the surfactant solution using a mechanical disperser “CLEARMIX” (manufactured by M Technic Co., Ltd.) having a circulation path. A monomer solution of the exemplified compound (19) is mixed and dispersed, and a uniform dispersed particle diameter (110 nm)
A dispersion liquid (emulsion liquid) containing emulsified particles (oil droplets) having the following formula was prepared. On the other hand, 19.1 g of a polymerization initiator (potassium persulfate: KPS) was added to latex (1H) and ion-exchanged water 24
0 ml of an initiator solution dissolved in 0 ml of ion-exchanged water
ml was added and the system was heated to 80 ° C. afterwards,
The emulsion (second stage polymerization) was performed by adding the emulsion to the system and heating and stirring at 80 ° C. for 3 hours.
A latex (a dispersion of resin particles having a structure in which the surface of resin particles made of a high molecular weight resin is coated with an intermediate molecular weight resin) was obtained. This is designated as “latex (1M)”.

(3) Formation of outer layer (third stage polymerization): An initiator obtained by dissolving 22.8 g of a polymerization initiator (KPS) in 200 ml of ion-exchanged water in the latex (1M) obtained as described above. The solution was added, and a monomer mixture consisting of 850 g of styrene, 252 g of n-butyl acrylate, 98 g of methacrylic acid, and 32 g of n-octyl-3-mercaptopropionate was dropped at 80 ° C. over 1 hour. did. After completion of the dropping, polymerization (third stage polymerization) was performed by heating and stirring for 2 hours, and then 30 ° C.
Cooled to a latex (which has a central portion composed of a high-molecular-weight resin, an intermediate layer composed of an intermediate-molecular-weight resin, and an outer layer composed of a low-molecular-weight resin.
(A dispersion liquid of composite resin particles). This latex is referred to as “latex (HMLP-1)”.
The weight average molecular weight (Mw) of the resin particles constituting the latex (HMLP-1) was 8,900. Also,
The weight average particle size of the resin particles was 125 nm.

[Production Example 1Bk] 90 g of sodium n-dodecyl sulfate was dissolved in 1600 ml of ion-exchanged water with stirring. While stirring this solution, 200 g of carbon black “Mogal L” (manufactured by Cabot Corporation) was gradually added.
Next, "Clear Mix" (M Technique Co., Ltd.)
To prepare a dispersion of colorant particles (hereinafter referred to as “colorant dispersion (Bk)”). The particle size of the colorant particles in this colorant dispersion liquid (Bk) was measured by using an electrophoretic light scattering photometer “ELS-800”.
It was 101 nm in weight average particle diameter when measured using (manufactured by Otsuka Electronics Co., Ltd.).

The latex obtained in Preparation Example HP-1 (H
P-1) 3000 g, 2500 g of the latex (MP-1) obtained in Preparation Example MP-1, 6000 g of the latex (LP-1) obtained in Preparation Example LP-1, 2,000 g of ion-exchanged water, and coloring 1800 g of the agent dispersion liquid (Bk) was charged and stirred in a reaction vessel equipped with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a stirring device. After adjusting the internal temperature to 30 ° C., a 5N aqueous sodium hydroxide solution was added to the solution to adjust the pH to 11.0. Next, an aqueous solution in which 526 g of magnesium chloride hexahydrate was dissolved in 720 ml of ion-exchanged water was added over 10 minutes at 30 ° C. with stirring. After standing for 3 minutes, heating was started, and the system was heated to 90 ° C. over 6 minutes (heating rate = 10 ° C. /
Minutes). In that state, "Coulter counter TA-II"
The volume average particle diameter of the fused particles measured by the above becomes 6.5 μm, and the shape measuring device (F
When the average circularity of the fused particles (colored particles) measured by PIA) reached 0.860, Preparation Example MP-1
2000 g of the latex (MP-1) obtained in the above, and 3000 of the latex (LP-1) obtained in Preparation Example LP-1
g of magnesium chloride and 400 g of magnesium chloride.
and an aqueous solution dissolved in ml, and stirred for 30 minutes. Next, an aqueous solution in which 1150 g of sodium chloride was dissolved in 7000 ml of ion-exchanged water was added to stop the particle growth, and fusion was continued by heating and stirring at a liquid temperature of 85 ° C. for 2 hours as an aging treatment.
Thereafter, the mixture was cooled to 30 ° C. under the condition of 8 ° C./min, the pH was adjusted to 2.0 by adding hydrochloric acid, and the stirring was stopped. The generated fused particles are filtered, washed repeatedly with ion-exchanged water,
Thereafter, drying was performed with warm air at 40 ° C. to obtain toner particles. The toner particles thus obtained are referred to as “toner particles 1B
k ”.

[Production Examples 2Bk to 12Bk] According to the recipe shown in Table 1 below, (1) latex (dispersion liquid of resin particles (A)) initially charged in a reaction vessel to form colored particles (core particles) (The amount used is the same), (2)
The type of latex (dispersion liquid of resin particles (B)) added to form the resin layer (shell) (the amount used is the same); (3) Fusing at the time of adding the latex to form the resin layer Average circularity of particles (core particles),
Toner particles were obtained in the same manner as in Production Example 1Bk, except that at least one of (4) aging temperature and (5) aging time was changed. The toner particles thus obtained are referred to as “toner particles 2Bk” to “toner particles 12Bk”.

In Production Example 1Bk, when the volume average particle size of the fused particles became 6.5 μm and the average circularity became 0.860, 2000 g of latex MP-1 and 3000 g of latex LP-1 were added. Production Example 1Bk except that 5000 g of latex LP-1 was used instead of
In the same manner as in the above, toner particles were obtained. The toner particles thus obtained are referred to as “toner particles 13Bk”.

[Comparative Production Example 1bk] According to the recipe shown in Table 1 below, except that no latex ((MP-1) and (LP-1)) for forming a resin layer (shell) was added. Toner particles were obtained in the same manner as in Example 2Bk. The toner particles thus obtained are referred to as “comparative toner particles 1bk”.

[0161]

[Table 1]

[Production Example 1Y] A dye (CI Solvent Yellow 93) 200 g was used instead of carbon black.
Colorant particles using (weight average particle size = 105 nm)
(Hereinafter referred to as “colorant dispersion (Y)”), and prepared in the same manner as in Production Example 1Bk except that the colorant dispersion (Y) was used instead of the colorant dispersion (Bk). Similarly, toner particles were obtained. The toner particles thus obtained are referred to as “toner particles 1Y”.

[Production Example 1M] Instead of carbon black, 200 g of a pigment (CI Pigment Red 122) was used.
Colorant particles using (weight average particle diameter = 110 nm)
(Hereinafter referred to as “colorant dispersion (M)”), and prepared in the same manner as in Production Example 1Bk except that the colorant dispersion (M) was used instead of the colorant dispersion (Bk). Similarly, toner particles were obtained. The toner particles thus obtained are referred to as “toner particles 1M”.

Production Example 1C A pigment (CI pigment blue 15: 3) 200 was used in place of carbon black.
g and colorant particles (weight average particle size = 110 n)
m)) (hereinafter referred to as “colorant dispersion (C)”), except that the colorant dispersion (C) was used in place of the colorant dispersion (Bk). In the same manner as in 1Bk, toner particles were obtained. The toner particles thus obtained are referred to as “toner particles 1C”.

[Comparative Production Example 1y] A dye (CI Solvent Yellow 93) 200 g instead of carbon black
To prepare toner particles in the same manner as in Comparative Production Example 1bk, except that the colorant dispersion liquid (Y) was prepared in place of the colorant dispersion liquid (Bk). Was.
The toner particles thus obtained are referred to as “comparative toner particles 1y”.

[Comparative Production Example 1m] 200 g of a pigment (CI Pigment Red 122) instead of carbon black
Was used to prepare a colorant dispersion (M), and toner particles were obtained in the same manner as in Comparative Production Example 1bk except that the colorant dispersion (M) was used instead of the colorant dispersion (Bk). Was.
The toner particles thus obtained are referred to as “comparative toner particles 1 m”.

[Comparative Production Example 1c] A pigment (CI Pigment Blue 15: 3) 200 was used in place of carbon black.
g) to prepare a colorant dispersion (C), and the toner particles are prepared in the same manner as in Comparative Production Example 1bk except that the colorant dispersion (C) is used instead of the colorant dispersion (Bk). Obtained. The toner particles thus obtained are referred to as “comparative toner particles 1c”.

The toner particles thus obtained (toner particles 1Bk to 13Bk, toner particle 1Y, toner particle 1M, toner particle 1C, comparative toner particle 1bk, comparative toner particle 1y, comparative toner particle 1m, For each of the comparative toner particles 1c), the volume average particle diameter, the average circularity, the standard deviation of the circularity, and the CV value of the circularity were measured.
The results are shown in Table 2 below.

[0169]

[Table 2]

(* The “circularity” is: FPIA-100
0 (made by Toa Medical Electronics Co., Ltd.)
The measurement was performed under the conditions of 0.3 μl and the number of detection particles = 1500 to 5000. )

Each of the toner particles 1Bk to 13Bk, the toner particle 1Y, the toner particle 1M, the toner particle 1C, the comparative toner particle 1bk, the comparative toner particle 1y, the comparative toner particle 1m, and the comparative toner particle 1c has hydrophobicity. Silica (number average primary particle size = 12 nm, hydrophobicity = 68) was added at a ratio of 1.0 mass%, and hydrophobic titanium oxide (number average primary particle size = 20 nm, hydrophobicity = 6).
3) was added at a ratio of 1.2% by mass, and mixed with a Henschel mixer. The shape and particle size of these toner particles do not change depending on the addition of hydrophobic silica and hydrophobic titanium oxide.

Next, each of the toner particles to which the hydrophobic silica and the hydrophobic titanium oxide were added and a ferrite carrier coated with a silicone resin and having a volume average particle diameter of 60 μm were mixed, and a developer having a toner concentration of 6% by mass was mixed. Was prepared. These developers are used as toner particles 1Bk to 13Bk,
Toner particles 1Y, toner particles 1M, toner particles 1C, comparative toner particles 1bk, comparative toner particles 1y, comparative toner particles 1m, and comparative toner particles 1c, developers 1Bk to 13Bk, developer 1Y, Developer 1M, developer 1C, comparative developer 1bk, comparative developer 1y, comparative developer 1m, and comparative developer 1c.

<Examples 1 to 13 and Comparative Example 1 (Test for Actual Photographing of Black Toner)> For each of the developers 1Bk to 13Bk and the comparative developer 1bk, the digital copying machine “7
065 "(manufactured by Konica Corporation) at a temperature of 25 ° C. and a relative humidity of 80% in a normal temperature and high humidity environment.
Perform a live-action test to print 200,000 sheets of originals with% pixel ratio,
Image density and fog density were measured at the beginning of image formation and after 200,000 sheets were formed. Here, "Image density"
Used a solid black image and evaluated its reflection density in absolute density using RD-918 manufactured by Macbeth. "Fog density" was measured using a solid white image, and RD-91 manufactured by Macbeth Co., Ltd.
Using No. 8, the evaluation was made based on the relative density when the reflection density of the paper was "0". The results are shown in Table 3 below.

As a fixing method, a pressure fixing type heat fixing device was used. The specific configuration is as follows. Cylindrical shape (inner diameter = 40 mm, wall thickness = 1.0 mm, full width = 310 m) made of aluminum alloy with a built-in heater in the center
A heating roller (upper roller) is formed by coating the core metal surface of m) with a tube (thickness = 120 μm) made of tetrafluoroethylene-perfluoroalkylvinyl ether copolymer (PFA), and a cylinder made of iron is formed. The surface of the metal core (inner diameter = 40 mm, wall thickness = 2.0 mm) is sponge-like silicone rubber (Asker C hardness = 4).
8, thickness = 2 mm) to form a pressure roller (lower roller), and the heating roller and the pressure roller are brought into contact with each other with a total load of 150 N to obtain 5.8.
A nip having a width of mm was formed. Using this fixing device, the printing linear velocity was set to 250 mm / sec. As a cleaning mechanism of the fixing device, a web-type supply system impregnated with polydiphenyl silicone (having a viscosity of 10 Pa · s at 20 ° C.) was used. The fixing temperature was controlled at 175 ° C. by the surface temperature of the heating roller. The amount of silicone oil applied was 0.1 mg / A4.

[0175]

[Table 3]

Example 14 and Comparative Example 2 (Real-Image Test of Color Toner) A combination of the developer 1Bk, the developer 1Y, the developer 1M and the developer 1C, the comparative developer 1bk, and the comparative developer 1y For each of the combination of the comparative developer 1m and the comparative developer 1c, using a digital color copying machine “Konica 3015” (Konica Corporation) under a normal temperature and high humidity environment of a temperature of 25 ° C. and a relative humidity of 80%. A real-image test for continuously printing 50,000 sheets of a full-color original having a pixel rate of 25% was performed.
For each of the 10,000th image, the color of the solid image portion of the secondary color (red, blue, green) is referred to as “Macbeth Color-Eye 700”.
0 ", and the color difference was calculated using the CMC (2: 1) color difference equation. The results are shown in Table 4 below. CMC (2:
1) If the color difference obtained by the color difference equation is 5 or less, it can be said that the change in the tint of the formed image is acceptable.

As the fixing method, a pressure fixing type heat fixing device was used. The specific configuration is as follows. Cylindrical shape (inner diameter = 40 mm, wall thickness = 1.0 mm, full width = 310 m) made of aluminum alloy with a built-in heater in the center
A heating roller (upper roller) is formed by coating the core metal surface of m) with a tube (thickness = 120 μm) made of tetrafluoroethylene-perfluoroalkylvinyl ether copolymer (PFA), and a cylinder made of iron is formed. The surface of the metal core (inner diameter = 40 mm, wall thickness = 2.0 mm) is sponge-like silicone rubber (Asker C hardness = 4).
8, thickness = 2 mm) to form a pressure roller (lower roller), and the heating roller and the pressure roller are brought into contact with each other with a total load of 150 N to obtain 5.8.
A nip having a width of mm was formed. Using this fixing device, the printing linear velocity was set to 250 mm / sec. As a cleaning mechanism of the fixing device, a web-type supply system impregnated with polydiphenyl silicone (having a viscosity of 10 Pa · s at 20 ° C.) was used. The fixing temperature was controlled at 175 ° C. by the surface temperature of the heating roller. The amount of silicone oil applied was 0.6 mg / A4.

[0178]

[Table 4]

[0179]

(1) In the toner according to the present invention, the amount of the colorant present on the particle surface is small, and the excellent chargeability and developability of the toner are hardly affected by the use environment. (2) According to the toner of the present invention, even when subjected to long-term image formation in a high humidity environment, a change in image density and fogging hardly occur. (3) According to the toner of the present invention, even when subjected to long-term color image formation in a high-humidity environment, a change in tint does not easily occur in the formed image.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Meisho Shirase 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation (72) Inventor Hiroyuki Yamada 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation (72) Invention Person Ken Omura 2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Corporation F-term (reference) 2H005 AA11 AA13 AA15 AB03 AB06 AB07 EA06 EA07 FB01

Claims (13)

[Claims] 1. A toner particle comprising a resin layer (shell) formed by fusing resin particles to the surface of colored particles (core particles) containing a resin and a colorant by a salting out / fusion method. A toner characterized in that: 2. The surface of colored particles (core particles) obtained by salting out / fusing the resin particles (A) and the colorant particles,
A toner comprising toner particles having a resin layer (shell) formed by fusing the resin particles (B) by a salting out / fusion method. 3. The toner according to claim 2, wherein the resin particles (A) have a weight average molecular weight (MwA) of 1.
5,000 to 500,000, and the following equation is satisfied between the weight average molecular weight (MwA) and the weight average molecular weight (MwB) of the resin particles (B). Formula) 0.1 ≦ (MwA / MwB) ≦ 20.0 4. The toner according to claim 2, wherein the resin fine particles (B) contain a low molecular weight resin having a weight average molecular weight (Mw) of 5,000 to 20,000. Toner. 5. The composite resin particle according to claim 2, wherein at least one of the resin particles (A) and the resin fine particles (B) is obtained by a multi-stage polymerization method. A toner characterized in that: 6. A method of forming a resin layer (shell) by fusing resin particles to the surface of colored particles (core particles) containing a resin and a colorant by salting out / fusion. Of producing toner. 7. A step of salting out / fusing the resin particles (A) and the colorant particles to form colored particles (core particles); and forming a salted out / fused surface on the surface of the obtained colored particles (core particles). And fusing the resin particles (B) by adhesion to form a resin layer (shell). 8. The method for producing a toner according to claim 7, wherein a step of forming colored particles (core particles) and a step of forming a resin layer (shell) on the surface of the colored particles are performed continuously. A method for producing a toner. 9. The method for producing a toner according to claim 7, wherein a resin layer (shell) is provided on the surface of the colored particles (core particles) having an average circularity of 0.850 to 0.950. A method for producing a toner, comprising a step of forming. 10. The method for producing a toner according to claim 7, wherein the resin particles (A) have a weight average molecular weight (MwA) of 1 or 2.
5,000 to 500,000, and the following formula is satisfied between the weight average molecular weight (MwA) and the weight average molecular weight (MwB) of the resin particles (B). Production method. Formula) 0.1 ≦ (MwA / MwB) ≦ 20.0 11. The method for producing a toner according to claim 7, wherein the resin fine particles (B) have a weight average molecular weight (Mw) of 5,000 to 20,000. A method for producing a toner, comprising a low molecular weight resin. 12. The method for producing a toner according to claim 7, wherein at least one of the resin particles (A) and the resin fine particles (B) is obtained by a multi-stage polymerization method. A method for producing a toner, which is a composite resin particle. 13. An image forming method including a fixing step by a contact heating method, wherein the toner according to claim 1 is used.