JP2003029459A - Toner for developing electrostatic latent image, image forming method and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide toner for developing electrostatic latent image where an image formation of high image quality can be carried out without generating any fixing failure by having deformation of the toner particles sufficiently comply to ruggedness of paper or ruggedness of the surface of a heat roller even when a heat roller fixing method is used in combination with polymerized method toner where the particle size distribution and form are made uniform, image forming method and image forming apparatus using the method. SOLUTION: In the toner for developing of electrostatic latent image, it is characteristic that the average degree of roundness is from 0.94 to 0.98, the average value of the diameter that is equivalent to one for a circle is from 2.6 to 7.4 μm and the inclination of the degree of roundness against the diameter that is equivalent to one for a circle is from -0.005 to -0.001.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic latent image developing toner, an image forming method using the same, and an image forming apparatus.

[0002]

2. Description of the Related Art In recent years, with the development of digital image processing technology, digital image formation has become the mainstream even in an image forming method based on an electrostatic latent image developing system such as an electrophotographic system.

A digital image forming method is 1200
It is basically based on the visualization of small dot images such as dpi (dots / inch; the number of dots per 2.54 cm), and high image quality technology that faithfully reproduces these small dot images is required.

In order to improve the image quality as described above, the particle size of the electrostatic latent image developing toner (sometimes simply referred to as toner) is being reduced. In the past, in image formation by an electrostatic latent image developing method such as an electrophotographic method, a so-called pulverized toner obtained by classifying toner powder obtained by mixing a binder resin (binder resin) and a pigment, kneading and pulverizing the mixture is used. It has been used mainly. However, the toner obtained through such a manufacturing process has a limitation in reducing the toner particle size and homogenizing the particle size distribution. It is difficult to reduce the toner particle size and achieve uniform particle size distribution and shape.
Therefore, it is difficult to achieve a sufficiently high image quality in an electrophotographic image using such a pulverized toner.

In recent years, so-called polymerization toners obtained by the suspension polymerization method or emulsion polymerization method have been attracting attention as means for achieving a reduction in the particle size of the toner particles and a uniform particle size distribution and shape. The polymerization toner is used as a toner by uniformly dispersing a raw material monomer in an aqueous system and then polymerizing it. There are various methods among these methods, but the most noticeable one is the method of associating (salting out and fusing) the resin particles and the colorant particles obtained by the suspension polymerization method or the emulsion polymerization method. is there. Since it is easy to produce toner particles with a small particle size and a uniform particle size distribution, practical studies are underway, but the manufacturing technology is still in the development stage.

On the other hand, as a method of fixing the toner image formed on the image forming support (transfer material) such as paper, the image forming support on which the toner image is formed is placed between the heating roller and the pressure roller. The heat roller fixing method of passing and fixing is widely adopted.

However, in the heat roller fixing method, when used in combination with a polymerization method toner in which the toner particles have a small particle size and the particle size distribution and the shape are uniform, the toner is used for the unevenness of the paper and the unevenness of the surface of the heat roller. There is a problem that the deformation of the particles cannot be sufficiently tracked and a fixing failure occurs.

[0008]

The present invention has been made to solve the above problems.

That is, even when the heat roller fixing method is used in combination with the polymerization method toner in which the toner particles have a small particle size and the particle size distribution and the shape are uniform, the toner is formed on the unevenness of the paper or the unevenness of the surface of the heat roller. An object of the present invention is to provide an electrostatic latent image developing toner capable of forming a high quality image without sufficiently causing deformation of particles and causing fixing failure, and an image forming method and an image forming apparatus using the toner. .

[0010]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made relatively large toner particles present in a toner having a small particle size and a uniform particle size distribution and shape in a range that does not adversely affect the image quality. , And found that the fixability is significantly improved.

However, the "relatively large toner particles" to be added here, unless their shape and particle size distribution are sufficiently controlled as in the case of the component having a reduced diameter, cause selective development and selective transfer due to the difference in particle size. There's a problem.

That is, in general, with a toner having a constant shape and particle size distribution, the large toner particles are developed and transferred. If the selective development and selective transfer are continued, the toner is scattered around the halftone image, and the resolution is deteriorated. In addition, a small-diameter toner component accumulates in the developing device and fusion occurs on the developing roller, which may cause problems such as fogging due to toner charge inhibition and toner scattering. Further, in the transfer step, problems such as transfer omission and image unevenness due to filming of the photoconductor occur.

Therefore, the "relatively large toner particles" are not perfectly spherical but irregularly shaped, and the toner mainly used for image formation has a particle size and a circular shape so that the toner becomes closer to a spherical shape and has a uniform particle size distribution. The present inventors have found that it is necessary to design so as to have a gradient every degree, and have completed the present invention.

That is, the object of the present invention is achieved by adopting any one of the following configurations. [1] The average circularity is 0.94 to 0.98, the average equivalent circle diameter is 2.6 to 7.4 μm, and the inclination of the circularity with respect to the equivalent circle diameter is −0.005 to −. 0.001
The toner for developing an electrostatic latent image according to claim 1.

[2] The average equivalent circle diameter is 3.4 to 6.
Is 6 μm, and the slope of the circularity with respect to the equivalent circle diameter is −0.
The toner for developing an electrostatic latent image according to [1], which is 004 to -0.002.

[3] Equivalent circle diameter d _{10 at} cumulative 10%
And the equivalent circle diameter d ₉₀ at a cumulative 90%, d ₉₀ / d ₁₀
Is 1.2 to 1.8, the toner for developing an electrostatic latent image according to [1] or [2].

[4] At least a polymerizable monomer is obtained by polymerizing in an aqueous medium, which is characterized by [1] to
The toner for developing an electrostatic latent image according to any one of [3].

[5] At least resin particles are obtained by salting out / fusing in an aqueous medium [1] to
[4] The toner for developing an electrostatic latent image according to any one of [4].

[6] BET specific surface area is 1.1 to 4.0
m ² / g, the surface abundance of silicon atoms measured by ESCA is 6 to 12 area%, and the abundance of carbon atoms is 50 to 75 area%.
The toner for developing an electrostatic latent image according to any one of [1] to [5].

[7] In the image forming method including a step of converting an electrostatic latent image formed on a photoconductor into a visible image, transferring the visible image onto recording paper, and heating and fixing the image, the visible image is converted into [1]. An image forming method comprising: using the toner for developing an electrostatic charge image according to any one of [5] to [5].

[8] An image forming apparatus using the image forming method described in [7], wherein the photosensitive member is irradiated by digital exposure.

The method for producing the toner for developing an electrostatic latent image of the present invention is not particularly limited, but it is a so-called polymerization method, that is, a method in which at least a polymerizable monomer is polymerized in an aqueous medium to obtain toner particles. Is preferred. Further, the toner particles are preferably obtained by salting out / fusing the obtained resin particles in an aqueous medium. This is because it is possible to produce toner particles having a small particle size and a controlled particle size distribution and shape by salting out / fusing resin particles produced by the polymerization method, particularly resin particles in an aqueous medium. is there.

The shape of the toner of the present invention has an average circularity (shape coefficient) represented by the following formula of 0.94 to 0.98, and more preferably 0.93 to 0.97.

Average circularity = (equivalent diameter of circle) / (peripheral length of projected image of particle) As a method of measuring the average circularity, FPIA-
2100 (manufactured by Sysmec) can be used for measurement. At this time, the equivalent circle diameter is defined by the following equation.

Equivalent circle diameter = 2π (sum of particle areas / π) ^{1/2 Further} , the average value of the equivalent circle diameter is 2.6 to 7.4 μm,
The slope of the circularity with respect to the equivalent circle diameter is -0.005 to -0.
It is 001. More preferably, the average equivalent circle diameter is in the range of 3.4 to 6.6 μm, and the slope of the circularity with respect to the equivalent circle diameter is −0.004 to −0.002.

The inclination of the circle equivalent diameter is measured by a flow type particle image analyzer FPIA-2100 for every 10% of the cumulative number of toner particles, and the relationship with the circularity is plotted along the horizontal axis. It may be drawn as equivalent diameter (μm) -vertical axis circularity, and the primary correlation (y = αx + b) may be observed (α is the slope of the circle equivalent diameter).

At this time, R ² is preferably 0.35 to 0.95 from the viewpoint of enhancing the uniformity of charging and the uniformity of halftone. Here, R is represented by the following formula 1.

[0028]

[Equation 1]

Further, in order to produce a toner having an inclination of a circle-equivalent diameter, irregular-shaped toner particles having a slightly larger particle size may be mixed with spherical toner particles having a smaller particle size. Alternatively, in the method of assembling toner particles by associating resin particles described later, after adding an aggregating agent in the associating step, a stirring blade shape is appropriately selected, stirring strength is controlled, and a shearing force is applied to larger particles. As an easy condition, a method of shifting to filtration and drying steps may be used.

It is possible to control to fall within the range of the present invention by preferably adding a terminating agent for stopping salting out / fusion and then growing the toner particles by 0.2 to 1.0 μm.

Further, in the present invention, the surface charge amount of the toner
From the viewpoint of aligning the
Diameter d_TenAnd equivalent circle diameter d at cumulative 90%₉₀Ratio with d₉₀
/ D _TenIs preferably 1.2 to 1.8. This range
If you are in a circle, you can control the scattering of dots,
It is possible to obtain high-quality images with high uniformity in tone.
come.

Further, it is preferable to add silica fine particles as an external additive, in which case the BET specific surface area of the toner is 1.1 to 4 from the viewpoint of suppressing humidity dependence of charging, that is, suppressing fluctuation of image quality due to humidity. .0m ² / g, the surface abundance of silicon atoms measured Te ESCA is 6-12 area%, it is preferable abundance of carbon atoms is 50 to 75 area%.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION In the method for producing a toner of the present invention, as a method for forming particles in an aqueous medium which can be preferably used, for example, JP-A-63-186253 can be used.
No. 63-282749, JP-A-7-146583.
The method described in each of the publications, etc., and the method of salting out / fusing resin particles to form the resin particles can be used.

The resin particles used in the production of the toner of the present invention preferably have a weight average particle diameter of 50 to 2000 nm, and these resin particles can be obtained by any of the granulation polymerization methods such as emulsion polymerization, dispersion polymerization and suspension polymerization. good. Preferably, resin particles obtained by emulsion polymerization are used.

Hereinafter, examples of resin particle materials and manufacturing methods will be described. << Material >> [Monomer] As the polymerizable monomer, a radical-polymerizable monomer is an essential constituent component, and a crosslinking agent can be used if necessary. Further, it is preferable to contain at least one radical-polymerizable monomer having the following acidic group or radical-polymerizable monomer having a basic group.

(1) Radical Polymerizable Monomer The radical polymerizable monomer component is not particularly limited, and conventionally known radical polymerizable monomers can be used. Also, in order to satisfy the required characteristics, 1
One kind or a combination of two or more kinds can be used.

Specifically, aromatic vinyl monomers, (meth) acrylic acid ester monomers, vinyl ester monomers, vinyl ether monomers, monoolefin monomers, diolefin monomers. A monomer, a halogenated olefin-based monomer or the like can be used.

The aromatic vinyl monomer is, for example,
Styrene, o-methylstyrene, m-methylstyrene,
p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, p-ethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n- Examples thereof include styrene-based monomers such as octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, 2,4-dimethylstyrene, and 3,4-dichlorostyrene, and derivatives thereof. .

Examples of the (meth) acrylic acid ester-based monomer include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate. , Butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, γ-aminoacrylate propyl, stearyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate and the like.

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

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

Examples of the mono-olefin type monomer include ethylene, propylene, isobutylene, 1-butene, 1-pentene, 4-methyl-1-pentene and the like.

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

As the halogenated olefin-based monomer,
Examples thereof include vinyl chloride, vinylidene chloride, vinyl bromide and the like.

(2) Crosslinking agent As the crosslinking agent, a radical polymerizable crosslinking agent may be added in order to improve the characteristics of the toner. Radical polymerizable cross-linking agents include divinylbenzene, divinylnaphthalene,
Examples thereof include those having two or more unsaturated bonds such as divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate and diallyl phthalate.

(3) Radical polymerizable monomer having an acidic group or radical polymerizable monomer having a basic group Radical polymerizable monomer having an acidic group or radical polymerizable monomer having a basic group For example, an amine compound such as a carboxyl group-containing monomer, a sulfonic acid group-containing monomer, a primary amine, a secondary amine, a tertiary amine, or a quaternary ammonium salt may be used. it can.

Examples of the radically polymerizable monomer having an acidic group include acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, maleic acid monobutyl ester, and carboxylic acid group-containing monomers. Maleic acid monooctyl ester etc. are mentioned.

Examples of the sulfonic acid group-containing monomer include styrene sulfonic acid, allyl sulfosuccinic acid, octyl allyl sulfosuccinate and the like.

These may have a structure of an alkali metal salt such as sodium or potassium or an alkaline earth metal salt such as calcium.

Examples of the radical polymerizable monomer having a basic group include amine compounds, such as dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and quaternary compounds of the above four compounds. Ammonium salt, 3-dimethylaminophenyl acrylate, 2-hydroxy-3-methacryloxypropyltrimethylammonium salt, acrylamide, N-butylacrylamide, N, N-dibutylacrylamide,
Piperidyl acrylamide, methacrylamide, N-butyl methacrylamide, N-octadecyl acrylamide, vinyl pyridine, vinylpyrrolidone, vinyl N-methylpyridinium chloride, vinyl N-ethylpyridinium chloride, N, N-diallylmethylammonium chloride, N, N- Examples include diallylethylammonium chloride.

As the radical-polymerizable monomer used in the present invention, a radical-polymerizable monomer having an acidic group or a radical-polymerizable monomer having a basic group is contained in an amount of 0.1 to 15 of all monomers. The radical-polymerizable cross-linking agent is preferably used in an amount of 0.1 to 10 mass% with respect to the total radical-polymerizable monomers, although it depends on its characteristics.

[Chain Transfer Agent] A commonly used chain transfer agent can be used for the purpose of adjusting the molecular weight.

The chain transfer agent is not particularly limited, and examples thereof include mercaptans such as octyl mercaptan, dodecyl mercaptan, tert-dodecyl mercaptan, carbon tetrabromide and styrene dimer.

[Polymerization Initiator] The radical polymerization initiator used in the present invention can be appropriately used as long as it is water-soluble.
For example, persulfates (potassium persulfate, ammonium persulfate, etc.), azo compounds (4,4′-azobis-4-cyanovaleric acid and its salts, 2,2′-azobis (2-amidinopropane) salt, etc.), peroxides A compound etc. are mentioned.

As the polymerization temperature, any temperature may be selected as long as it is at least the minimum radical generation temperature of the polymerization initiator, but for example, a range of 50 ° C. to 90 ° C. is used. However, it is also possible to carry out the polymerization at room temperature or higher by using a combination of a polymerization initiator started at room temperature, for example, hydrogen peroxide-reducing agent (ascorbic acid etc.).

[Surfactant] In order to carry out polymerization using the above-mentioned radically polymerizable monomer, it is necessary to disperse oil droplets in an aqueous medium using a surfactant. The surfactant that can be used in this case is not particularly limited, but the following ionic surfactants can be mentioned as suitable examples.

As the ionic surfactant, sulfonates (sodium dodecylbenzene sulfonate, sodium arylalkyl polyether sulfonate, 3,3-
Disulfone diphenylurea-4,4-diazo-bis-amino-8-naphthol-6-sulfonate sodium, ortho-carboxybenzene-azo-dimethylaniline,
2,2,5,5-tetramethyl-triphenylmethane-
4,4-diazo-bis-β-naphthol-6-sulfonate, etc.), sulfuric acid ester salts (sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc.), fatty acid salts (sodium oleate, laurin) Acid sodium salt, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, calcium oleate and the like).

Further, nonionic surfactants can also be used. Specifically, polyethylene oxide, polypropylene oxide, a combination of polypropylene oxide and polyethylene oxide, ester of polyethylene glycol and higher fatty acid, alkylphenol polyethylene oxide, ester of higher fatty acid and polyethylene glycol, ester of higher fatty acid and polypropylene oxide, sorbitan ester. Etc. can be given.

In the present invention, these are mainly used as an emulsifier during emulsion polymerization, but they may be used for other steps or purposes.

[Colorant] Examples of the colorant include inorganic pigments, organic pigments and dyes.

As the inorganic pigment, conventionally known ones can be used. Specific inorganic pigments are exemplified below.

Examples of black pigments include furnace black, channel black, acetylene black,
Carbon black such as 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. Further, the amount of the pigment added is 2 to 20% by mass, preferably 3 to 15% by mass, based on the polymer.

When used as a magnetic toner, the above-mentioned magnetite can be added. In this case, from the viewpoint of imparting a predetermined magnetic characteristic, 20 to 6 is contained in the toner.
It is preferable to add 0% by mass.

Conventional organic pigments and dyes can be used. Specific organic pigments and dyes are exemplified below.

As the pigment for magenta or red,
C. 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. I. Pigment Red 16,
C. I. Pigment Red 48: 1, C.I. I. Pigment Red 53: 1, C.I. I. Pigment Red 57:
1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 123, C.I. I. Pigment Red 139,
C. 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.

Pigments for orange or yellow include C.I. I. Pigment Orange 31, C.I. I. Pigment Orange 43, C.I. I. Pigment Yellow 12,
C. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 15, C.I.
I. Pigment Yellow 17, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 94, C.I. I.
Pigment Yellow 138, C.I. I. Pigment Yellow 180, C.I. I. Pigment Yellow 185, C.I.
I. Pigment Yellow 155, C.I. I. Pigment Yellow 156 and the like.

As the pigment for green or cyan,
C. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 15: 3,
C. 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, 111,
122, C.I. I. Solvent Yellow 19, 44,
77, 79, 81, 82, 93, 98, 103, 104, 112, 162, C.I. I. Solvent Blue 25, 36, 60, 70, 93,
Id. 95 and the like can be used, and a mixture thereof can also be used.

These organic pigments and dyes can be used alone or in combination of two or more as desired. The amount of the pigment added is 2 to 20% by mass with respect to the polymer,
Preferably 3 to 15 mass% is selected.

The colorant may be used after surface modification. As the surface modifier, conventionally known ones can be used, and specifically, a silane coupling agent, a titanium coupling agent, an aluminum coupling agent and the like can be preferably used.

<< Manufacturing Step >> In the manufacturing step of the polymerized toner of the present invention, a step of dispersing a monomer solution in which a releasing agent is dissolved in an aqueous medium and then preparing resin particles containing the releasing agent by a polymerization method, A step of fusing the resin particles in an aqueous medium using the resin particle dispersion, a washing step of removing the obtained particles by filtering the obtained particles from the aqueous medium, a step of drying the obtained particles, Further, it is composed of an external additive adding step of adding an external additive and the like to the particles obtained by further drying. Here, the resin particles may be colored particles. In addition, non-colored particles can also be used as the resin particles. In this case, the colored particles are obtained by adding the colorant particle dispersion liquid or the like to the dispersion liquid of the resin particles and then fusing in an aqueous medium. You can

In particular, as the fusion method, a method of salting out / fusing using the resin particles produced in the polymerization step is preferable. When non-colored resin particles are used, the resin particles and the colorant particles can be salted out / fused in an aqueous medium.

Further, not only the colorant and the release agent, but also the charge control agent which is a constituent element of the toner can be added as particles in this step.

Here, the aqueous medium means that the main component is water, and the content of water is 50% by mass or more. Examples of substances other than water include organic solvents that dissolve in water, such as methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran. It is preferably an organic solvent that does not dissolve the resin,
Alcohol-based organic solvents such as methanol, ethanol, isopropanol and butanol are particularly preferable.

As a preferred polymerization method in the present invention, a monomer solution in which a releasing agent is dissolved in a monomer is dispersed by mechanical energy into oil droplets in an aqueous medium in which a surfactant having a critical micelle concentration or less is dissolved. A method in which a water-soluble polymerization initiator is added to the dispersion to carry out radical polymerization can be mentioned. In this case, an oil-soluble polymerization initiator may be added to the monomer before use.

The disperser for dispersing the oil droplets is not particularly limited, and examples thereof include Clearmix, an ultrasonic disperser, a mechanical homogenizer, a Manton-Gaulin or a pressure homogenizer.

There is a method in which the colorant particles are prepared by dispersing the colorant in an aqueous medium. This dispersion is carried out in water with the surfactant concentration above the critical micelle concentration (CMC).

The disperser at the time of dispersing the pigment is not particularly limited, but preferably a Clearmix, an ultrasonic disperser, a mechanical homogenizer, a pressure disperser such as Manton-Gorin or a pressure homogenizer, a sand grinder, a Getzmann mill or a diamond fine mill. And the like medium-type dispersers.

As the surfactant used here, the above-mentioned surfactant can be used. [Salting-out / fusion step] In the salting-out / fusion step, the salting-out agent is added as a flocculant having a critical flocculation concentration or higher to the water in which the resin particles and the colorant particles are present, and then the resin particles are added. By heating above the glass transition point of (1), salting out proceeds and at the same time fusion is performed.

Here, the salting-out agent includes, as the metal, lithium, potassium, sodium, magnesium, calcium, strontium, barium, aluminum, titanium and the like, and preferably potassium, sodium, magnesium, calcium, barium. . In addition, as a salt, chlorine salt, bromine salt, iodine salt,
Examples thereof include carbonates and sulfates.

When the fusion of the present invention is carried out by salting-out / fusion, the time after the salting-out agent is added and allowed to stand is controlled while monitoring the shape factor, but it is preferably as short as possible. The temperature at which the salting-out agent is added is not particularly limited, but is preferably 80 to 90 ° C.

Further, in the present invention, it is preferable to use a method of raising the temperature of the dispersion liquid of the resin particles as quickly as possible and heating it to the glass transition temperature of the resin particles or higher. The time required to raise the temperature is less than 30 minutes, preferably less than 10 minutes. Further, although it is necessary to raise the temperature quickly, the rate of temperature increase is preferably 1 ° C./minute or more. Although the upper limit is not particularly clear, it is preferably 15 ° C./min or less from the viewpoint of suppressing the generation of coarse particles due to the rapid progress of salting out / fusion. As a particularly preferable form, a method of continuously advancing salting out / fusion even at the time of reaching the glass transition temperature or higher can be mentioned. By using this method, fusion can be effectively progressed with the growth of particles,
The particle strength of the final toner can be increased and the durability can be improved.

The toner of the present invention preferably contains a release agent in its particles. By using a toner obtained by salting out / fusing resin particles containing a release agent, the release agent can be uniformly included in the toner particles, and the release agent is included even in the vicinity of the surface. The formed toner can be formed.

By thus salting out / fusing the resin particles containing the release agent in the resin particles with the colorant particles in the aqueous medium, a toner in which the release agent is finely dispersed can be obtained. You can

The following releasing agents are preferable. ^{R 1 - (OCO-R 2} ) n n is an integer of 1 to 4, preferably 2 to 4, more preferably 3 to 4, particularly preferably 4.

R ¹ and R ² represent a hydrocarbon group which may have a substituent. R ¹ has 1 to 40 carbon atoms, preferably 1 to 2 carbon atoms
0, more preferably 2 to 5, is preferable.

R ² has 1 to 40 carbon atoms, preferably 16 to
It is preferably 30, and more preferably 18 to 26.

Next, typical exemplified compounds will be described.

[0090]

[Chemical 1]

[0091]

[Chemical 2]

The addition amount is from 1 to 30% by mass, preferably from 3 to 25% by mass, based on the whole toner.

In addition to the colorant and the release agent, the toner may be added with a material capable of imparting various functions as a toner material. Specific examples include charge control agents. These components can be added by various methods such as a method of adding the components in the above-mentioned salting-out / fusing step, a method of incorporating them in the toner, a method of adding them to the resin particles themselves.

Similarly, the charge control agents are various known ones,
Moreover, the thing which can be disperse | distributed in water can be used. Specific examples thereof include a quaternary ammonium salt compound, a fluorine compound, an azo metal complex, a salicylic acid metal salt, or a metal complex thereof.

<< External Additives >> The toner of the present invention has fluidity,
A so-called external additive may be added and used for the purpose of improving charging property and cleaning property.
These external additives are not particularly limited, and various inorganic fine particles, organic fine particles and lubricants can be used.

As the inorganic fine particles, conventionally known ones can be used. Specifically, silica, titanium, alumina fine particles and the like can be preferably used. The inorganic fine particles are preferably hydrophobic. Specifically, as the silica fine particles, for example, commercially available products R-805, R-976, R-974, and R-97 manufactured by Nippon Aerosil Co., Ltd.
2, R-812, R-809, Hovst HVK-
2150, H-200, commercial product TS- manufactured by Cabot Corporation
720, TS-530, TS-610, H-5, MS-
5 and the like.

Examples of titanium fine particles include commercial products T-805 and T-604 manufactured by Nippon Aerosil Co., Ltd., and commercial products MT-100S, MT-100B and MT-5 manufactured by Teika.
00BS, MT-600, MT-600SS, JA-
1. Commercial products TA-300SI and TA- manufactured by Fuji Titanium Co., Ltd.
500, TAF-130, TAF-510, TAF-5
10T, commercial products IT-S, IT-OA manufactured by Idemitsu Kosan Co., Ltd.
IT-OB, IT-OC, etc. are mentioned.

Examples of the alumina fine particles include commercial products RFY-C and C-604 manufactured by Nippon Aerosil Co., Ltd., and commercial products TTO-55 manufactured by Ishihara Sangyo Co., Ltd.

As the organic fine particles, spherical organic fine particles having a number average primary particle diameter of about 10 to 2000 nm can be used. As this, a homopolymer such as styrene or methyl methacrylate or a copolymer thereof can be used.

Examples of the lubricant include salts of zinc, aluminum, copper, magnesium and calcium stearic acid, salts of zinc, manganese, iron, copper and magnesium of oleic acid, zinc palmitate, copper, magnesium and calcium. And the like, salts of zinc and calcium of linoleic acid, and metal salts of higher fatty acids such as salts of zinc and calcium of ricinoleic acid.

The addition amount of these external additives is preferably 0.1 to 5 mass% with respect to the toner. As a method of adding the external additive, various known mixing devices such as a Turbuler mixer, a Henschel mixer, a Nauter mixer, and a V-type mixer can be used.

<< Developer >> The toner of the present invention may be used as a one-component developer or a two-component developer.

When used as a one-component developer, a non-magnetic or magnetic one-component developer can be used.

Further, it can be used as a two-component developer by mixing with a carrier. In this case, conventionally known materials such as metals such as iron, ferrite and magnetite and alloys of these metals with metals such as aluminum and lead can be used as the magnetic particles of the carrier. Ferrite particles are particularly preferable. The volume average particle diameter of the magnetic particles is preferably 15 to 100 μm, more preferably 25 to 80 μm.

The volume average particle diameter of the carrier is typically measured by a laser diffraction type particle size distribution measuring apparatus "HELOS" equipped with a wet disperser (SYMPATIC (SYMP).
(Made by ATEC)).

The carrier is preferably one in which magnetic particles are further coated with a resin, or a so-called resin dispersion type carrier in which magnetic particles are dispersed in a resin. The resin composition for coating is not particularly limited, but, for example, an olefin resin, a styrene resin, a styrene-acrylic resin, a silicone resin, an ester resin, a fluorine-containing polymer resin, or the like is used. The resin for forming the resin-dispersed carrier is not particularly limited, and known ones can be used. For example, styrene-acrylic resin, polyester resin, fluorine resin, phenol resin, etc. are used. be able to.

The toner of the present invention is fixed by an image forming method and an image forming apparatus including a fixing step by a heat fixing device.

An example of the image forming method and the image forming apparatus of the present invention will be described first. FIG. 1 is a schematic configuration diagram of an image forming apparatus showing an embodiment of the present invention. Reference numeral 4 denotes a photoconductor, which is a typical example of the electrostatic latent image forming member in the present invention. An organic photoconductor (OPC), which is a photosensitive layer, is formed on the outer peripheral surface of an aluminum drum base, and rotates in the direction of the arrow at a predetermined speed. In this embodiment, the photoconductor 4 has an outer diameter of 60 mm.

In FIG. 1, exposure light is emitted from the semiconductor laser light source 1 based on information read by a document reading device (not shown). This is distributed by the polygon mirror 2 in the direction perpendicular to the paper surface of FIG. 1, and is irradiated onto the surface of the photoconductor through the fθ lens 3 that corrects the image distortion to form an electrostatic latent image. The photoconductor is previously uniformly charged by the charger 5, and starts rotating clockwise in accordance with the timing of image exposure.

The electrostatic latent image on the surface of the photoconductor is developed by the developing device 6, and the formed developed image is transferred by the operation of the transfer device 7 to the recording material 8 which is conveyed at a timing. Further, the photoconductor 4 and the transfer material 8 are separated by a separator (separation pole) 9, but the toner development image is transferred and carried on the transfer material 8 and guided to a fixing device 10 to be fixed.

The untransferred toner and the like remaining on the surface of the photoconductor are
It is cleaned by a cleaning device 11 of a cleaning blade type, the residual charge is removed by pre-charge exposure (PCL) 12, and it is uniformly charged again by the charging device 5 for the next image formation.

The transfer material is typically plain paper,
There is no particular limitation as long as it can transfer an unfixed image after development, and of course, a PET base for OHP and the like are included.

The cleaning blade 13 has a thickness of 1
A rubber-like elastic body of about 30 mm is used, and urethane rubber is most often used as the material. Since this is used in pressure contact with the photoconductor, heat is easily transmitted, and it is desirable to keep it away from the photoconductor when the image forming operation is not performed.

In recent years, in the field of electrophotography in which an electrostatic latent image is formed on a photoconductor and the latent image is developed to obtain a visible image, it is easy to improve the image quality, convert it, edit it, etc. Research and development of an image forming method using a digital method capable of forming an image are actively performed.

As a scanning optical system optically modulated by a digital image signal from a computer or a copy original employed in this image forming method and apparatus, an acousto-optic modulator is interposed in a laser optical system, and the acousto-optic modulator is used to emit light. There are a device for modulating and a device for directly modulating the laser intensity by using a semiconductor laser. A spot-like image is formed by spot exposure on the uniformly charged photoconductor from these scanning optical systems.

The beam emitted from the above-mentioned scanning optical system has a circular or elliptical luminance distribution which approximates a normal distribution in which the skirt spreads to the left and right. For example, in the case of a laser beam, it is usually the main component on the photoconductor. One or both of the scanning direction and the sub-scanning direction is a very small circle or ellipse of 20 to 100 μm.

Further, the image forming apparatus may be configured such that the photoconductor 4 and the process cartridge including at least one of the charging device 5, the developing device 6, the cleaning device 11 and the transfer device 7 are mounted.

FIG. 2 is a sectional view showing an example of a fixing device used in the image forming apparatus using the toner of the present invention. The fixing device shown in FIG. And a roller 20. Note that FIG.
In the figure, T is a toner image formed on the transfer material (image forming support) 8.

The heating roller 21 has a coating layer 22 made of fluororesin or an elastic material formed on the surface of a cored bar 23, and contains a heating member 24 made of a linear heater.

The core metal 23 is made of metal and has an inner diameter of 10 to 70 mm. The metal forming the core 23 is not particularly limited, but examples thereof include metals such as iron, aluminum, and copper, and alloys thereof.

The wall thickness of the cored bar 23 is 0.1 to 15 mm, and is determined in consideration of the balance between the demand for energy saving (thinning) and the strength (depending on the constituent materials). For example,
In order for the core metal made of aluminum to maintain the same strength as the core metal made of iron of 0.57 mm, it is necessary to make the wall thickness 0.8 mm.

Examples of the fluororesin constituting the surface layer of the coating layer 22 include PTFE (polytetrafluoroethylene) and PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer).

The surface layer of the coating layer 22 made of a fluororesin has a thickness of 10 to 500 μm, preferably 20 to 40.
It is set to 0 μm.

When the thickness of the surface layer of the coating layer 22 made of a fluororesin is less than 10 μm, the function as the coating layer cannot be sufficiently exerted, and the durability as a fixing device cannot be secured. On the other hand, there is a problem in that the surface layer of the coating layer having a thickness of more than 500 μm is easily scratched by paper dust, and toner or the like adheres to the scratched portion, resulting in image stain.

As the elastic body forming the coating layer 22, it is preferable to use silicone rubber and silicone sponge rubber having good heat resistance such as LTV, RTV and HTV.

Asker C, which is an elastic material constituting the coating layer 22
The hardness is less than 80 °, preferably less than 60 °.

The thickness of the cover layer 22 made of an elastic material is 0.1 to 30 mm, preferably 0.1 to 20 mm.
It is said that

Asker C, which is an elastic material constituting the coating layer 22
If the hardness exceeds 80 ° and the thickness of the coating layer 22 is less than 0.1 mm, the fixing nip cannot be increased, and the effect of soft fixing (for example, smoothed interface Effect of improving color reproducibility by toner layer)
Can't exert.

As the heating member 24, a halogen heater can be preferably used. The pressure roller 20 is
A coating layer 26 made of an elastic material is formed on the surface of the cored bar 25. The elastic body that constitutes the coating layer 26 is not particularly limited, and various soft rubbers such as urethane rubber and silicone rubber and sponge rubber can be exemplified. The silicone rubbers exemplified as the constituents of the coating layer 26 and It is preferable to use silicone sponge rubber.

Asker C, which is an elastic material constituting the coating layer 26
The hardness is less than 80 °, preferably less than 70 °, and more preferably less than 60 °.

The coating layer 26 has a thickness of 0.1 to 30 m.
m, preferably 0.1 to 20 mm.

Asker C, which is an elastic material constituting the coating layer 26
If the hardness exceeds 80 ° and the thickness of the coating layer 26 is less than 0.1 mm, the fixing nip cannot be increased and the soft fixing effect cannot be exhibited.

The material forming the core metal 25 is not particularly limited, but examples thereof include metals such as aluminum, iron and copper, and alloys thereof.

The contact load (total load) between the heating roller 21 and the pressure roller 20 is usually 40 to 350 N, preferably 50 to 300 N, and more preferably 50.
~ 250N. This contact load is applied to the heating roller 2
It is defined in consideration of the strength of 1 (thickness of the cored bar 23), and for a heating roller having a cored bar made of iron of 0.3 mm, for example, it is preferably 250 N or less.

From the viewpoint of offset resistance and fixing property, the nip width is preferably 4 to 10 mm, and the surface pressure of the nip is 0.6 × 10 ⁵ Pa to 1.5.
It is preferably × 10 ⁵ Pa.

As an example of the fixing conditions by the fixing device shown in FIG. 2, the fixing temperature (surface temperature of the heating roller 21) is 150 to 210 ° C., and the fixing linear velocity is 80 to 640 mm.
/ Sec.

The fixing device used in the present invention may be provided with a cleaning mechanism if necessary. In this case, as a method of supplying silicone oil to the upper roller (heating roller) of the fixing unit, a method of supplying and cleaning with a pad, roller, web, etc. impregnated with silicone oil can be used.

As the silicone oil, one having high heat resistance is used, and polydimethyl silicone, polyphenylmethyl silicone, polydiphenyl silicone or the like is used. Since those having a low viscosity have a large outflow amount at the time of use, those having a viscosity at 20 ° C. of 1 to 100 Pa · s are preferably used.

However, the effect of the present invention is particularly remarkable when the step of forming an image is performed by a fixing device that does not supply silicone oil or the supply amount of silicone oil is extremely low. Therefore, even when the silicone oil is supplied, the supply amount is preferably 2 mg or less per A4 sheet.

Further, it is possible to avoid problems such as deterioration of offset resistance over time due to alteration of silicone oil and contamination of the optical system and the band electrode by silicone oil.

Here, the amount of silicone oil supplied was set to the fixing device (between rollers) heated to a predetermined temperature to transfer paper (A4).
It is calculated by continuously passing 100 sheets of white paper of a size) and measuring the mass change (Δw) of the fixing device before and after passing the paper (Δw / 100).

[0142]

EXAMPLES The present invention will be described in detail below with reference to examples, but it goes without saying that the embodiments of the present invention are not limited thereto. In addition, "part" in a sentence represents a "mass part."

Production Example of Toner Resin Particles [Latex (1HML)] (1) Preparation of Core Particles (First Stage Polymerization) In a 5000 ml separable flask equipped with a stirrer, a temperature sensor, a cooling pipe, and a nitrogen introducing device. 7.08 g of the following anionic surfactant (101) C ₁₀ H ₂₁ (OCH ₂ CH ₂ ) ₂ OSO ₃ Na was added, and a surfactant solution (aqueous medium) dissolved in 3010 g of ion-exchanged water was charged, and a nitrogen stream was introduced. Bottom 2
The temperature inside the flask was raised to 80 ° C. while stirring at a stirring speed of 30 rpm.

9.2 g of a polymerization initiator (potassium persulfate: KPS) was added to 200 g of deionized water in this surfactant solution.
Was added to the solution of the initiator, and the temperature was adjusted to 75 ° C. Then, 70.1 g of styrene and 1 of n-butyl acrylate were added.
A monomer mixture liquid consisting of 9.9 g and methacrylic acid 10.9 g was added dropwise over 1 hour, and this system was heated and stirred at 75 ° C. for 2 hours to perform polymerization (first-stage polymerization), A latex (dispersion of resin particles composed of a high molecular weight resin) was prepared. This is designated as "latex (1H)".

(2) Formation of Intermediate Layer (Second Stage Polymerization) In a flask equipped with a stirrer, styrene 1
Into a monomer mixture consisting of 05.6 g, 30.0 g of n-butyl acrylate, 6.2 g of methacrylic acid and 5.6 g of n-octyl-3-mercaptopropionic acid ester, the above compound 19) was used as a release agent. It is referred to as a represented compound (hereinafter, "Exemplified Compound 19)". ) 98.0 g was added, and the mixture was heated to 90 ° C. and dissolved to prepare a monomer solution.

On the other hand, an anionic surfactant (see the above (10
1)) A surfactant solution prepared by dissolving 1.6 g in 2700 ml of ion-exchanged water is heated to 98 ° C., and the latex (1H), which is a dispersion liquid of core particles, is converted into a solid content in the surfactant solution. After 28 g was added, a monomer solution of the above-exemplified compound 19 was mixed and dispersed for 8 hours by a mechanical disperser having a circulation path "CLEARMIX" (manufactured by M-Technique Co., Ltd.) to obtain emulsified particles (oil). Drops) were prepared.

Then, a polymerization initiator (KP
S) Add an initiator solution prepared by dissolving 5.1 g of deionized water in 240 ml and deionized water of 750 ml. Polymerization (second-stage polymerization) is performed by heating and stirring this system at 98 ° C. for 12 hours to obtain a latex (composite 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). A dispersion) was obtained. This is designated as "latex (1HM)".

(3) Formation of Outer Layer (Third Stage Polymerization) An initiator solution prepared by dissolving 7.4 g of a polymerization initiator (KPS) in 200 ml of deionized water in the latex (1HM) obtained as described above. Was added. Under the temperature condition of 80 ° C., 300 g of styrene and 95 of n-butyl acrylate
g, 15.3 g of methacrylic acid, and 10.4 g of n-octyl-3-mercaptopropionic acid ester were added dropwise over 1 hour. After completion of the dropping, polymerization (third stage polymerization) was carried out by heating and stirring for 2 hours, followed by cooling to 28 ° C. and latex (a central part made of a high molecular weight resin, an intermediate layer made of an intermediate molecular weight resin, and a low layer). A dispersion liquid of composite resin particles having an outer layer made of a molecular weight resin and containing the exemplified compound 19) in the intermediate layer was obtained. This latex is referred to as "latex (1HML)".

The composite resin particles constituting this latex (1HML) are 138,000, 80,000 and 1
Has a peak molecular weight of 3,000, and
The weight average particle diameter of the composite resin particles was 122 nm.

[Latex (2HML)] Instead of the anionic surfactant (101), an anionic surfactant (sodium dodecylbenzene sulfonate: SDS)
Latex (1 HM) except that 7.08 g was used.
In the same manner as in L), a latex (dispersion liquid of composite resin particles having a central portion made of a high molecular weight resin, an intermediate layer made of an intermediate molecular weight resin, and an outer layer made of a low molecular weight resin) was obtained. This latex is referred to as "latex (2HML)".

The composite resin particles constituting this latex (2HML) are 138,000, 80,000 and 1
It has a peak molecular weight of 2,000, and
The weight average particle diameter of the composite resin particles was 110 nm.

[Production of Toner 1] 59.0 g of the anionic surfactant (101) was dissolved in 1600 ml of ion-exchanged water with stirring, and while stirring this solution, carbon black "Regal 330" (manufactured by Cabot Corporation) 420. A dispersion liquid of colorant particles (hereinafter referred to as “colorant dispersion liquid 1”) was prepared by gradually adding 0 g and then performing a dispersion treatment using “CLEARMIX” (manufactured by M-Technique Co., Ltd.). The particle size of the colorant particles in this colorant dispersion was measured using an electrophoretic light scattering photometer "ELS-800" (manufactured by Otsuka Electronics Co., Ltd.), and the weight average particle size was 89.
was nm.

420.7 g of latex (1HML) (in terms of solid content), 900 g of ion-exchanged water, and 1166 g of colorant dispersion 1 were placed in a reaction vessel (a temperature sensor, a cooling pipe, a nitrogen introducing device, and a stirring device). (Four-necked flask)
And stirred. After adjusting the temperature in the container to 30 ° C,
A 5 mol / 1000 ml aqueous sodium hydroxide solution was added to this solution to adjust the pH to 9.0.

Then, magnesium chloride hexahydrate 1
An aqueous solution prepared by dissolving 2.1 g in 1000 ml of ion-exchanged water was added with stirring at 30 ° C. for 10 minutes. Next, after standing for 3 minutes, the temperature rise was started, and the temperature of this system was raised to 70 ° C. over 3 minutes to generate salting out / fused particles. In that state, the circle-equivalent diameter and average circularity particle diameter of the associated particles were measured with FPIA-2100, and when a predetermined value was reached, 2 g of sodium chloride was added to ion-exchanged water 1000
Add an aqueous solution dissolved in ml to suppress particle growth,
Then, it was grown to 0.2 to 1.0 μm to form an inclination of circularity with respect to the equivalent circle diameter. Further, as the aging treatment, the particles were continuously fused by heating and stirring at a liquid temperature of 90 ° C. for 2 minutes (aging step).

Then, the mixture was cooled to 30 ° C., hydrochloric acid was added to adjust the pH to 2.0, and stirring was stopped. The salted-out / fused particles produced were filtered and washed repeatedly with ion-exchanged water at 45 ° C. Then, it was dried with warm air at 40 ° C., 0.8 parts by mass of hydrophobic silica and 1.0 part by mass of hydrophobic titanium oxide were added, and the peripheral speed of the rotary blade of a 10,000 ml Henschel mixer was set to 30 m / s. After setting and mixing for 25 minutes, Toner 1 was obtained.

[Production of Toners 2 to 4] Latex (2HML) was used in place of latex (1HML) in production of Toner 1. When salting out / fusing particles produced a circle equivalent diameter of 2.5 μm and an average circularity of 0.987 in the production of salting out / fusing particles, an aqueous solution prepared by dissolving 8 g of sodium chloride in 1000 ml of ion-exchanged water was added. The grain growth was stopped. Liquid temperature of 90 for aging treatment
By heating and stirring at 20 ° C. for 20 minutes, fusion of particles was continued to obtain a dispersion liquid of colored particles. The obtained dispersion liquid of colored particles is referred to as a dispersion liquid S of colored particles. On the other hand, in the formation of the associated particles, when the equivalent circle diameter of the associated particles reached 7.8 μm and the average circularity of 0.875, an aqueous solution prepared by dissolving 80 g of sodium chloride in 1000 ml of ion-exchanged water was added to stop the particle growth. By performing the same treatment, a colored particle dispersion L was obtained. Next, the colored particle dispersion liquid S and the colored particle dispersion liquid L are mixed by FPIA-2100 while monitoring the equivalent circle diameter of the associated particles and the average circularity particle diameter,
Then, it was cooled to 30 ° C., and hydrochloric acid was added to adjust the pH to 2.
It was adjusted to 0 and stirring was stopped. The associated particles produced were filtered, washed repeatedly with ion-exchanged water at 45 ° C., and then dried with warm air at 40 ° C. to obtain 0.8 parts by mass of hydrophobic silica and 1.0 part by mass of hydrophobic titanium oxide. Added, 10,0
Rotor speed of 00ml Henschel mixer is 30m
/ S and mixed for 25 minutes to obtain toners 2 to 5 shown in Table 1.

[Production of Toner 1 for Comparison] Latex (1
HML) 420.7 g (in terms of solid content), ion-exchanged water 900 g, and colorant dispersion 1 166 g, a reaction container (four-necked flask) equipped with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a stirring device. ) And stirred. After adjusting the temperature in the container to 30 ° C, add 5 mol / 1000 to this solution.
The pH was adjusted to 9.5 by adding ml of sodium hydroxide aqueous solution.

Then, magnesium chloride hexahydrate 1
An aqueous solution prepared by dissolving 2.1 g in 1000 ml of ion-exchanged water was added with stirring at 30 ° C. for 10 minutes. Next, after standing for 3 minutes, the temperature rise was started and the temperature of this system was raised to 90 ° C. over 60 minutes to generate associated particles. In that state, the particle size of the associated particles was measured with "Coulter Counter TA-II", and when the number average particle size reached 3.5 µm, an aqueous solution prepared by dissolving 80.4 g of sodium chloride in 1000 ml of ion-exchanged water. Was added to stop grain growth. Further, as the aging treatment, the particles were fused and the crystalline substance was phase-separated by heating and stirring at a liquid temperature of 98 ° C. for 12 hours (aging step).

Then, the mixture was cooled to 30 ° C., hydrochloric acid was added to adjust the pH to 2.0, and stirring was stopped. The formed associated particles were filtered and repeatedly washed with ion exchanged water at 45 ° C. Then, it was dried with warm air at 40 ° C., 0.8 parts by mass of hydrophobic silica and 1.0 part by mass of hydrophobic titanium oxide were added, and the peripheral speed of the rotary blade of a 10,000 ml Henschel mixer was set to 30 m / s. After setting and mixing for 25 minutes, Comparative Toner 1 was obtained.

Next, the toners for comparison 2 to 4 were prepared by adjusting the temperature of the aging treatment liquid and the treatment time.

Table 1 shows the average circularity, the average equivalent circle diameter, and the inclination of the circularity with respect to the equivalent circle diameter of the toners 1 to 5 and the comparative toners 1 to 4 prepared above.

[0162]

[Table 1]

Manufacture of Carrier Manufacture of Ferrite Core Material 18 mol% MnO, 4 mol% MgO, Fe ₂ O ₃
78 mol% was pulverized with a wet ball mill for 2 hours, mixed and dried, and then temporarily calcined by holding at 900 ° C. for 2 hours, and this was pulverized with a ball mill for 3 hours to form a slurry. A dispersant and a binder were added, the mixture was granulated by a spray dryer, dried, and then main-baked at 1200 ° C. for 3 hours to obtain ferrite core material particles having a resistance value of 4.3 × 10 ⁸ Ω · cm.

Production of Coating Resin First, cyclohexylmethacrylate / cyclohexylmethacrylate was prepared by an emulsion polymerization method in which sodium benzenesulfonate having an alkyl group having 12 carbon atoms was used as a surfactant at a concentration of 0.3% by mass in an aqueous medium. A copolymer of methyl methacrylate (copolymerization ratio 5/5) was synthesized, and the volume average primary particle diameter was 0.1 μmm and the weight average molecular weight (Mw) was 200,00.
0, number average molecular weight (Mn) 91,000, Mw / Mn =
2.2, resin fine particles having a softening point temperature (Tsp) of 230 ° C. and a glass transition temperature (Tg) of 110 ° C. were obtained. The resin fine particles were azeotroped with water in the emulsified state, and the residual monomer amount was 510 ppm.

Next, 100 parts by mass of the ferrite core material particles and 2 parts by mass of the resin fine particles are charged into a high-speed stirring mixer equipped with stirring blades, and stirred and mixed at 120 ° C. for 30 minutes to utilize the action of mechanical impact force. Thus, a resin-coated carrier having a volume average particle diameter of 61 μm was obtained.

Production of Developer Each of the colored particles added with the external additive and the carrier were mixed to prepare a developer having a toner concentration of 6% by mass.

Production of Photosensitive Member P1 The following coating liquid was applied onto a cylindrical conductive support having a length of 380 mm and a diameter of 60 mm.

<Undercoat layer> Titanium chelate compound (TC-750 manufactured by Matsumoto Pharmaceutical Co., Ltd.) 30 g Silane coupling agent (KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.) 17 g 2-Propanol 150 ml Cylindrical conductive support using the above coating liquid. A film thickness of 0.
It was applied so as to have a thickness of 5 μm.

<Charge Generating Layer> Y-type titanyl phthalocyanine (titanyl phthalocyanine having a maximum peak at 27.2 ° of Bragg angle 2θ (± 0.2 °) in Cu-Kα characteristic X-ray diffraction spectrum measurement) 60 g Silicone modified Butyral resin (X-40-1211M: manufactured by Shin-Etsu Chemical Co., Ltd.) 700 g 2-butanone 2000 ml was mixed and dispersed for 10 hours using a sand mill to prepare a charge generation layer coating solution.

This coating solution was applied onto the undercoat layer by a dip coating method to form a charge generation layer having a film thickness of 0.2 μm.

<Charge Transport Layer> Charge Transport Material N- (4-methylphenyl) -N- {4- (β-phenylstyryl) phenyl} -p-toluidine 225 g Polycarbonate (viscosity average molecular weight 30,000) 300 g Antioxidant Agent (Exemplified compound 1-3) 6 g Dichloromethane 2000 ml was mixed and dissolved to prepare a charge transport layer coating solution. This coating solution was applied onto the charge generation layer by a dip coating method to form a charge transport layer having a dry film thickness of 20 μm.

<Protective Layer> Methyltrimethoxysilane 150 g Dimethyldimethoxysilane 30 g Reactive charge transporting compound 15 g Polyvinylidene fluoride particles (volume average particle size 0.2 μm) 10 g Antioxidant 0.75 g 2-Propanol 75 g 3% acetic acid 5 g was mixed to prepare a coating liquid for the resin layer. A resin layer having a thickness of 2 μm is formed on the charge transport layer by a circular amount regulation type coating device on the charge transport layer, and the resin layer is heated and cured at 120 ° C. for 1 hour to form a siloxane resin layer. It was made.

As an evaluation machine, a photoconductor P1 and each developing device are installed in a digital copying machine (corona charging, laser exposure, reversal development, electrostatic transfer, nail separation, cleaning blade) having the image forming process shown in FIG. The agent was mounted and evaluated. The above digital copying machine was evaluated under the following conditions.

Charging conditions Charging device: Scorotron charger, initial charging potential of -750
V exposure condition Set the exposure amount to make the exposed portion potential -50V.

Development conditions DC bias; -550V transfer electrode; corona charging system Further, as a fixing device, iron was used as a core metal, and the surface was made of PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) having a thickness of 25 μm. ) Using a heating roller having a surface roughness Ra of 0.8 μm,
An iron cored bar was used as the pressure roller, and a pressure roller having a surface roughness Ra of 0.8 μm was used in which a 120 μm thick PFA tube was coated on the HTV silicone rubber.
The nip width is 3.8 mm and the linear velocity is 420 mm.
/ Sec.

The fixing device cleaning mechanism and the silicone oil supply mechanism are not attached. The fixing temperature was set at 165 ° C. by controlling the surface temperature of the heating roller.

The copying conditions are low temperature and low humidity environment (10 ° C., 20 ° C.).
% RH), 1 million continuous copies were made, and the following evaluation criteria were used to evaluate the offset resistance of the copied images, stains during image formation, standard glossiness, cleaning properties, and filming of the photoconductor.

For evaluation, an original image in which a character image having a pixel ratio of 7%, a human face photograph image, a solid white image, and a solid black image are equally divided into quarters is copied on A4 neutral paper.
The halftone, solid white image, solid black image, and fine line image were evaluated for every 10,000 sheets.

Offset resistance After 1,000 sheets of continuous printing were made on A4 size transfer paper, white paper was printed, and the appearance of stains on the white paper due to offset and the toner stain on the heat roller surface were visually evaluated.
As the transfer paper used for evaluation, fine paper 200 g /
Using m ² thick paper, paper traveling direction (heat roller circumferential direction)
A line image having a width of 0.3 mm and a length of 150 mm parallel to the image was formed.

⊚: Image offset on white paper and toner stain on heat roller are not observed at all ◯: Image offset on white paper is not confirmed, but toner stain is observed on heat roller ×: Image on white paper The evaluation rank in which the offset is confirmed is ⊚, ◯ is pass, and x is fail.

Evaluation of Fixable Temperature Region A fixed image was prepared while changing the heat roll temperature from 130 ° C. to 240 ° C. in steps of 10 ° C. When outputting a fixed image, A4 size plain paper (basis weight 64 g / m ² )
It was used.

Here, the fixing temperature range is 100
The case where the temperature was not lower than 0 ° C was judged as excellent "A", the case where the temperature was lower than 100 ° C and higher than 70 ° C was judged as good "B", the case where the temperature was lower than 70 ° C and higher than 40 ° C was evaluated as "C", and the case where temperature was lower than 40 ° C was judged as poor "D".

Uniformity of Halftone The uniformity of the halftone image due to the transferability variation after the continuous 1 million copies was evaluated.

The rank was divided into the following and the evaluation was displayed. A: Uniform image without unevenness B: Very thin uneven stripes are present C: There are several thin uneven stripes, but there is no problem in practical use D: Several clear uneven stripes are present Evaluation rank A to C were passed and D was rejected.

A 10% halftone dot image was formed on the entire surface of the fine dot dust image, and dust around the dots was observed with a magnifying glass. “A” indicates that dust could hardly be detected, “O” indicates that there was a slight amount of dust, but it was not noticeable unless attention was paid, and “X” indicates that dust could be clearly detected.

The toner filming on the photosensitive member and the toner filming on the developing roller are the results of observing the surface of the photosensitive member and the surface of the developing roller with the naked eye after every 10,000 copies.

[0187]

[Table 2]

As is clear from Table 2, Examples 1 to 5 in the present invention showed good characteristics in each item, but Comparative Examples 1 to 4 outside the present invention had problems.

[0189]

According to the present invention, the heat roller fixing system is
Even if the toner particles have a small particle size and are used in combination with a polymerization method toner having a uniform particle size distribution and shape, paper unevenness and
Deformation of toner particles sufficiently follows the irregularities on the surface of the heat roller, electrostatic latent image developing toner capable of high-quality image formation without causing fixing failure, and image forming method and image using the same A forming device can be provided.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an example of an image forming method and an image forming apparatus of the present invention.

FIG. 2 is a sectional view showing an example of a fixing device used in the image forming apparatus of the present invention.

[Explanation of symbols]

1 Semiconductor laser light source 2 polygon mirror 3 fθ lens 4 Electrostatic latent image forming body (photoreceptor) 5 charger 6 developer 7 Transfer device 8 recording materials 9 separation poles 10 Fixing device

Continued front page    (72) Inventor Hiroshi Yamazaki             2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica stock             In the company F-term (reference) 2H005 AA15 AB03 AB06 EA05 EA10

Claims (8)

[Claims] 1. The average circularity is 0.94 to 0.98, the average equivalent circle diameter is 2.6 to 7.4 μm, and the inclination of the circularity to the equivalent circle diameter is -0.005. ~-
The toner for developing an electrostatic latent image is 0.001. 2. The average value of equivalent circle diameters is 3.4 to 6.6 μm.
And the slope of the circularity with respect to the equivalent circle diameter is -0.004.
The toner for developing an electrostatic latent image according to claim 1, wherein the toner is from -0.002. 3. A ratio of a circle equivalent diameter d ₁₀ at a cumulative ₁₀ % and a circle equivalent diameter d ₉₀ at a cumulative 90%, d ₉₀ / d ₁₀ is 1.
The toner for developing an electrostatic latent image according to claim 1 or 2, wherein the toner is 2 to 1.8. 4. The toner for electrostatic latent image development according to claim 1, which is obtained by polymerizing at least a polymerizable monomer in an aqueous medium. 5. The toner for electrostatic latent image development according to claim 1, which is obtained by salting out / fusing at least resin particles in an aqueous medium. 6. A BET specific surface area of 1.1 to 4.0 m ² /
g, the surface abundance of silicon atoms measured by ESCA is 6 to 1
The toner for developing an electrostatic latent image according to any one of claims 1 to 5, wherein the toner has a surface area of 2 area% and a carbon atom content of 50 to 75 area%. 7. An image forming method comprising a step of converting an electrostatic latent image formed on a photoconductor into a visible image, transferring the visible image onto a recording sheet, and heating and fixing the visible image. 5. An image forming method, which is carried out using the electrostatic image developing toner according to any one of 5 above. 8. The image forming method according to claim 7,
An image forming apparatus characterized in that the photosensitive member is irradiated by digital exposure.