JP3491224B2 - Electrostatic latent image developing toner, image forming method and image forming apparatus using the same - Google Patents

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, image forming techniques for copying machines, printers, facsimiles and the like have been remarkably developed, and the most widely used one belongs to an electrostatic image forming method represented by an electrophotographic method. Is.

The reason is that the electrostatic image forming method such as the electrophotographic method can obtain a high quality image at a high speed, can form not only monochrome but also a color image, and has durability for long-term use. , It has stability.

However, with the improvement in performance of related technologies such as personal computers, the required performance level is increasing year by year, and further improvement and performance improvement are required to meet the demand.

It is needless to say that it is preferable to reduce the particle size of the electrostatic latent image developing toner (hereinafter also simply referred to as toner) in order to improve the image quality. However, in the case of producing a toner having a small particle diameter, the so-called conventional method of mixing and melting, kneading, and pulverizing a resin and a colorant requires a large amount of energy at the time of pulverization, which requires a great cost. Also, there are problems such as a large amount of classification loss in the classification process after crushing. Therefore, for example, JP-A-63-186253 and JP-A-63-282749
Japanese Patent Application Laid-Open No. 7-146583 discloses a so-called polymerization method toner, in particular, a method of producing a toner by associating resin particles in an aqueous medium. In this method, since the toner particle size can be adjusted in the aqueous medium by the degree of association of the particles, as a method for producing a small particle size toner, the generation of fine powder and a large amount of loss are not produced, and the cost is low. It can be said that this is an effective manufacturing method.

However, since the toner prepared by this method is produced by associating particles with each other, its interface is not composed only of completely fused particles, so that it can be used for a long period of time. In this case, there is a phenomenon in which crushing occurs due to agitation stress inside the developing device and collision energy due to mixing of the toners and mixing with the charging member, and fine particles are generated. When this phenomenon occurs, the fine powder adheres to the charging member or the developing device to lower the chargeability to the toner, and further, the fine powder increases the adhesiveness to the photoconductor, which causes the adhesion to the photoconductor. This causes a problem of causing image defects such as black spots and white spots.

As described above, although the toner prepared by associating the resin particles as the toner having a small particle diameter has the advantage of productivity, it has the above-mentioned problems and is not completely satisfactory in practical use.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art.

That is, the object of the present invention is to improve the stability over a long period when using a toner obtained by fusing resin particles in an aqueous medium, and even for long-term use. Provided are an electrostatic latent image developing toner capable of forming a stable image without a decrease in the maximum density, the occurrence of fog, and the occurrence of image defects, and an image forming method and an image forming apparatus using the same. Especially.

[0010]

Means for Solving the Problems As a result of intensive investigations by the present inventors, in an electrostatic latent image developing toner obtained by fusing resin particles in an aqueous medium, the resin particles constituting the toner are The present invention has been completed by finding that the above problems can be solved by making the particle size and the particle size of the large particle size external additive have a specific relationship.

That is, the above object can be achieved by adopting one of the following configurations.

[1] In a toner for developing an electrostatic latent image, which comprises at least resin particles fused in an aqueous medium and colored particles and an external additive, the external additive has a number average primary particle diameter (An).
m) and the weight average particle size (Bnm) of the resin particles have the following relationship (1) and are represented by the following formula (2) of the toner.
A toner for developing an electrostatic latent image having a shape factor within a range of 1.3 to 2.2 .

(1) 0.1 ≦ B / A ≦ 1.0 B = 50 to 2000 (2) Shape factor = ((maximum diameter / 2) ² × π) / projected area

[3] The toner for developing an electrostatic latent image according to [1], wherein the external additive is a titanic acid compound.

[4] The toner for developing an electrostatic latent image according to [1], wherein the external additive is titanium oxide.

[5] The toner for developing an electrostatic latent image according to [1], wherein the external additive is silica.

[0017] [6] The volume average particle diameter of the toner for developing an electrostatic latent image is 3～9Myuemu, and shape factor of 1.5
The toner for developing an electrostatic latent image according to any one of [1] to [5], wherein the toner particles within the range of 2.0 are 80% by number or more.

[ 7] In an image forming method of transferring an unfixed toner image formed on a photosensitive member through steps of uniform charging, image exposure and development to a recording material and then fixing the toner image, at least resin particles as a developer. A toner for developing an electrostatic latent image comprising colored particles obtained by fusing the above in an aqueous medium and an external additive is used. The number average primary particle diameter (Anm) of the external additive and the weight average particle diameter of the resin particles are used. (Bnm) has the following relationship (1),
The toner has a shape factor represented by the following formula (2) of 1.3 to
An image forming method characterized by being within the range of 2.2 .

(1) 0.1 ≦ B / A ≦ 1.0 B = 50 to 2000 (2) Shape factor = ((maximum diameter / 2) ² × π) / projected area [8] One on the photoreceptor In the image forming apparatus for transferring an unfixed toner image formed through the steps of charging, image exposure and development to a recording material and then fixing the image, colored particles obtained by fusing at least resin particles as a developer in an aqueous medium. A toner for electrostatic latent image development comprising: an external additive, and a number average primary particle diameter (Anm) of the external additive and a weight average particle diameter (B
nm) and the following relationship (1) with respect to
The shape factor represented by equation (2) is within the range of 1.3 to 2.2.
An image forming apparatus characterized in that it is in.

(1) 0.1 ≦ B / A ≦ 1.0 B = 50 to 2000 (2) Shape factor = ((maximum diameter / 2) ² × π) / projected area The present inventors have made diligent studies. As a result, it was found that the relationship between an external additive added to the surface of a toner obtained by fusing resin particles in an aqueous medium and ensuring stability over a long period of time is important. It was found that the relationship with the particle size of the resin particles for fusing with a medium is important, and the present invention has been completed.

The reason for this is not clear, but the present inventors presumed that a problem would occur due to the following reasons. That is, the toner obtained by fusing resin particles in an aqueous medium has fine irregularities formed on its surface. In addition, there may be a portion where the resin particles are not completely fused to each other. When stress is applied to this portion, local stress is likely to be applied to the external additive existing on the convex portion, the external additive is buried in that portion, and the stress on the toner becomes excessive due to the decrease in fluidity. As a result, the phenomenon in which toner is crushed occurs, and the above-mentioned problem occurs. As a result, the chargeability of the toner changes, and the chargeability of the toner decreases due to the burying of the external additive and the chargeability decreases due to the fusion of the generated fine powder to the charging member due to the long-term use. In addition, the phenomenon of increased fog occurs. Further, the generated fine powder adheres to the photoconductor, which causes image defects such as black spots and white spots.

It has been well known so far that in order to suppress the burying phenomenon of the external additive, it can be solved by adding an external additive having a large particle diameter. However, in the toner obtained by fusing resin particles as in the present invention, since there are fine irregularities, the adhesiveness between the external additive having a large particle diameter and the toner itself becomes low, and the detachment thereof is reduced. It often occurs, and the problem of contamination inside the aircraft is likely to occur. Due to this problem, it was not possible to easily add an external additive having a large particle diameter to the toner of the present invention.

As a result of earnest studies, the inventors of the present invention have found a countermeasure against it by estimating the mechanism of desorption of the external additive having a large particle size. In order to effectively retain the large particle size external additive on the toner surface of the present invention, it is necessary to increase the contact probability between the toner surface and the large particle size external additive, and the resin particles configured to increase the probability. It has been found that it is necessary to specify the relationship between the particle size of the external additive and the particle size of the external additive.

The reason why the effect of the present invention is obtained is as follows.
Although not necessarily clear, by using an external additive larger than the constituent resin particles, a plurality of resin particles can come into contact with the large particle size external additive. It is presumed that this makes it possible to hold the external additive between the fine protrusions present on the surface and improve the adhesiveness to the toner, so that detachment can be prevented.

Further, in the present invention, the effect can be more exerted by making the shape of the toner specific.

Further, the number average primary particle diameter of the external additive having a large particle diameter in the present invention is 100 by observation with a transmission electron microscope.
The one measured by image analysis is used after observing it at a magnification of 00 times. In the present invention, those having a wavelength of 50 to 5000 nm, preferably 80 to 2000 nm can be used.

Various inorganic fine particles, organic fine particles and the like can be used as the material constituting the fine particles used as the external additive.

Examples of the inorganic fine particles include various oxides, nitrides and borides. For example, silica, alumina, titania, zirconia, barium titanate, aluminum titanate, strontium titanate,
Magnesium titanate, zinc oxide, chromium oxide, cerium oxide, antimony oxide, tungsten oxide, tin oxide, tellurium oxide, manganese oxide, boron oxide, silicon carbide, boron carbide, titanium carbide, silicon nitride, titanium nitride, boron nitride, etc. can give. Especially titanic acid compounds,
Titanium oxide, silica and the like show excellent characteristics.

Further, the inorganic fine particles may be subjected to a hydrophobic treatment. When the hydrophobic treatment is performed, it is preferable to perform the hydrophobic treatment with a so-called coupling agent such as various titanium coupling agents and silane coupling agents, silicone oil and the like. Further, it is also preferable to carry out a hydrophobizing treatment with a higher fatty acid metal salt such as aluminum stearate, zinc stearate or calcium stearate.

Titanium coupling agents for hydrophobizing include tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzene sulfonyl titanate, bis (dioctyl pyrophosphate) oxyacetate titanate and the like. . Further, as the silane coupling agent, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β- (N
-Vinylbenzylaminoethyl) γ-aminopropyltrimethoxysilane hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane,
Examples thereof include isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane and p-methylphenyltrimethoxysilane.

Examples of the fatty acid and its metal salt include undecyl acid, lauric acid, tridecyl acid, dodecyl acid, myristic acid, palmitic acid, pentadecyl acid, stearic acid, heptadecyl acid, arachidic acid, montanic acid, oleic acid, linol. Examples thereof include long-chain fatty acids such as acids and arachidonic acid, and examples of the metal salts thereof include salts with metals such as zinc, iron, magnesium, aluminum, calcium, sodium and lithium.

Further, examples of the silicone oil include dimethyl silicone oil, methylphenyl silicone oil, amino-modified silicone oil and the like.

These compounds are preferably added in an amount of 1 to 10% by weight with respect to the inorganic fine particles for coating, preferably 3 to 7% by weight. Also, these materials can be used in combination.

Surface treatment with a polysiloxane having an ammonium salt as a functional group is also possible.

Examples of the organic fine particles that can be used in the present invention include organic fine particles made of styrene resin, styrene / acrylic resin, polyester resin, urethane resin and the like.

The method for producing the organic fine particles used in the present invention and the composition thereof are not particularly limited. Generally, vinyl-based organic fine particles are preferable. This is because it can be easily produced by a production method such as an emulsion polymerization method or a suspension polymerization method.

Specifically, styrene, α-methylstyrene, p-chlorostyrene, 3,4-dichlorostyrene,
p-phenylstyrene, p-ethylstyrene, 2,4-
Styrene or styrene derivatives such as dimethyl styrene and pt-butyl styrene, methyl methacrylate,
Methacrylic acid ester derivatives such as ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, 2-ethylhexyl methacrylate, methyl acrylate,
Acrylic ester derivatives such as ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, ethylene,
Olefin such as propylene and isobutylene, vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride, vinyl halide such as vinylidene fluoride, vinyl propionate, vinyl acetate and other vinyl esters, vinyl methyl ether, vinyl ethyl Vinyl ethers such as ethers, vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl hexyl ketone, N-vinyl compounds such as N-vinyl carbazole, N-vinyl indole and N-vinyl pyrrolidone, vinyl naphthalene and vinyl pyridine. Vinyl compounds, acrylonitrile, methacrylonitrile, acrylamide, N-butyl acrylamide, N, N-dibutyl acrylamide, methacrylamide, N-butyl methacrylamide, N-octadecyl acrylamide, etc. Is acrylic acid or methacrylic acid derivatives. These vinyl monomers can also be used alone or in combination.

The resin fine particles can be produced by an emulsion polymerization method or a suspension polymerization method. Emulsion polymerization is a method of adding the above monomer to water containing a surfactant and emulsifying it, and then polymerizing it, and as the surfactant, sodium dodecylbenzene sulfonate, polyvinyl alcohol, ethylene oxide adduct, and higher Any of those used as a surfactant such as sodium alcohol sulfate can be used, and there is no particular limitation.

Further, use of a reactive emulsifier, polymerization of a hydrophilic monomer, for example, a persulfate initiator such as vinyl acetate or methyl acrylate, a method of copolymerizing a water-soluble monomer,
So-called non-emulsion polymerization methods such as a method using a water-soluble resin or an oligomer, a method using a decomposable emulsifier, and a method using a cross-linking emulsifier are also suitable. Examples of reactive emulsifiers include sulfonates of acrylic acid amides and salts of maleic acid derivatives. The emulsion-free polymerization method has no influence of the residual emulsifier and is suitable when organic fine particles are used alone.

The polymerization initiator required for synthesizing the resin fine particles includes peroxides such as benzoyl peroxide and lauryl peroxide, and azo polymerization initiation such as azobisisobutyronitrile and azobisisovaleronitrile. Agent. The addition amount of these is preferably 0.1 to 2% by weight with respect to the monomer. If the amount is less than this amount, the polymerization reaction may be insufficient and the problem of residual monomer itself may occur. Further, if the amount is too large, the decomposition product of the polymerization initiator remains, which affects the charging property, and further, the polymerization reaction is too fast, which may cause a problem that the molecular weight becomes small. Furthermore, in the emulsion polymerization method or the like, potassium persulfate, sodium thiosulfate or the like can be used as a polymerization initiator.

It is preferable to use 0.1 to 5.0% by weight, preferably 0.5 to 3.0% by weight, of the fine particles having a large particle diameter with respect to the toner. If it is less than 0.1% by weight, the effect due to the addition is difficult to be exhibited, and if it is more than 5.0% by weight, the toner is not sufficiently retained on the toner surface, and desorption occurs. There is a possibility that it will end up.

As the external additive, in addition to the external additive having a large particle diameter of the present invention, an external additive having a smaller particle diameter than the external additive having a large particle diameter may be used in combination. In this case, as the external additive having a small particle diameter, those having a number average primary particle diameter of 5 to 40 nm can be used. The material is not particularly limited, and various organic fine particles and inorganic fine particles that can be used as the above-mentioned external additive having a large particle diameter can be used. Inorganic fine particles are preferable. When a large particle diameter and a small particle diameter external additive are used in combination, the present invention achieves the object of the invention by setting the relationship between the large particle diameter external additive and the resin particle diameter within the range of the present invention. be able to. As a ratio of the external additive having a large particle diameter and the external additive having a small particle diameter, a weight ratio of large particle diameter: small particle diameter = 1: 0.1 to 2.0 is preferable. As an effect of the external additive having a small particle diameter, it is considered that not only the fluidity can be imparted, but also the function of effectively holding the external additive having a large particle diameter can be imparted by covering the toner surface. The effect is effectively exhibited within the range of this ratio.

Next, the particle diameter of the toner obtained by fusing according to the present invention is preferably 3 to 9 μm in volume average particle diameter. This toner has a volume average particle diameter of Coulter Counter TA-
II, Coulter Multisizer, SLAD1100 (Laser diffraction type particle size measuring device manufactured by Shimadzu Corporation) and the like can be used for measurement.

In the Coulter Counter TA-II and Coulter Multisizer, the aperture diameter is 100 μm.
The measurement was performed using the aperture of No. 1 and the particle size distribution in the range of 2.0 to 40 μm.

The shape of the toner obtained by fusing has a shape factor represented by the following formula in the range of 1.3 to 2.2 and a shape factor in the range of 1.5 to 2.0. It is preferable that the toner particles are in a number of 80% by number or more.

Shape factor = ((maximum diameter / 2) ² × π) / projected area This shape factor was obtained by taking a photograph of toner particles magnified 500 times by a scanning electron microscope, and based on this photograph, “ SCANNING IMAGE ANALYS
ER "(manufactured by JEOL Ltd.) is used to analyze the photographic image. At this time, the shape factor of the present invention is measured by the above-mentioned calculation formula using 500 toner particles, and the arithmetic mean value thereof is taken as the shape factor.

When the shape factor is less than 1.3, the shape is rounded, so that the adhesiveness of the external additive is deteriorated, and the external additive having a large particle size is liable to be detached. It becomes difficult to exert the effect of. Further, when the shape factor exceeds 2.2, irregularization increases, so even if an external additive having a large particle size is added, crushing under stress such as development is effectively prevented. It becomes impossible to produce fine powder.

Further, when the number of toner particles having a shape factor in the range of 1.5 to 2.0 is 80% by number or more, the shape distribution can be made uniform. The existing state can be made uniform, and the effect of the present invention can be exerted over a long period of time.

The particle size of the resin particles for producing the developing toner particles of the present invention is measured using an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd. using a dispersion liquid of the resin particles. It is the value shown by the weight average particle size. In the present invention, it is 50 to 2000 nm, preferably 80 to 500 nm.

Next, materials, requirements, devices and the like used in the present invention will be further described.

The toner used in the present invention is a toner obtained by fusing resin particles in an aqueous medium.

The toner used in the present invention may be produced by fusing resin particles containing a colorant in an aqueous medium, but the polymerization stability when preparing the resin particles containing the colorant. From the viewpoint of the above problem and stabilization in toner production, a toner obtained by fusing resin particles, colorant particles and release agent particles in an aqueous medium is more preferable. Since the toner has a shape with irregularities on the surface from the time of toner production, and since it fuses in an aqueous medium, there is little difference in shape or surface property between particles, and as a result, the charge amount distribution Is sharp, and it is possible to obtain a finished image with excellent resolution with less toner scattering. In addition, it is as described above that this may largely contribute to the effect of the present invention.

As a method of fusing in an aqueous medium, for example, JP-A-63-186253 and 63-2827.
49, JP-A-7-146583, etc., and a method of salting out / fusing resin particles to form the resin particles.

The resin particles used in the production of the toner of the present invention may be formed by any of the granulation polymerization methods such as emulsion polymerization, suspension polymerization and seed polymerization, but the emulsion polymerization method is most preferably used in the present invention. .

Hereinafter, examples of resin particle materials and manufacturing methods will be described.

<< Material >> [Monomer] As the polymerizable monomer, a radically 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.

As the aromatic vinyl monomer, 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 type 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 the vinyl ether type monomer include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether and the like.

Examples of the monoolefin 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 Acidic Group or Radical Polymerizable Monomer Having Basic Group Radical Polymerizable Monomer Having Acidic Group or Radical Polymerizable Monomer Having 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 and octyl allyl sulfosuccinate.

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, vinyl pyrrolidone; 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 wt.

[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, and styrene dimer.

[Polymerization Initiator] The radical polymerization initiator used in the present invention can be appropriately used if 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.

Further, the above radical polymerization initiator can be used as a redox type initiator in combination with a reducing agent, if necessary. By using the redox type initiator, the polymerization activity can be increased, the polymerization temperature can be lowered, and further shortening of the polymerization time can be expected.

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 polymerize at room temperature or higher by using a combination of a polymerization initiator that starts at room temperature, for example, a combination of hydrogen peroxide and a reducing agent (ascorbic acid, etc.).

[Surfactant] In order to carry out emulsion polymerization using the above radically polymerizable monomer, it is necessary to carry out emulsion polymerization 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 emulsifiers during emulsion polymerization, but they may be used for other steps or purposes.

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

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. The amount of the pigment added is 2 to 20% by weight, preferably 3 to 15% by weight, 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 weight.

Conventionally known organic pigments can be used as the organic pigment. Specific organic pigments 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 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.

These organic pigments can be used alone or in combination of two or more as desired. The amount of the pigment added is 2 to 20% by weight, preferably 3 to 15% by weight, based on the polymer.

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.

<Production Process> The production process of the polymerized toner of the present invention includes a polymerization process of preparing resin particles by emulsion polymerization, a process of fusing resin particles in an aqueous medium using the resin particle dispersion, and A washing step of filtering the obtained particles from an aqueous medium to remove a surfactant and the like, a step of drying the obtained particles, and an external additive addition step of adding an external additive and the like to the particles obtained by further drying Etc. 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 and fusing 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 in an aqueous medium and fused.

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 one containing water as a main component and having a water content of 50% by weight or more. Examples of substances other than water include organic solvents that dissolve in water, and examples thereof include methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran, but preferably organic solvents that do not dissolve the resin. Alcoholic organic solvents such as methanol, ethanol, isopropanol and butanol are particularly preferable.

The colorant itself may be surface-modified before use. The surface modification method of the colorant involves dispersing the colorant in a solvent,
After the surface modifier is added therein, the temperature is raised to carry out the reaction. After completion of the reaction, the pigment is filtered, washed and filtered with the same solvent repeatedly, and dried to obtain a pigment treated with a surface modifier.

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 an ultrasonic disperser, a mechanical homogenizer,
Examples thereof include a pressure disperser such as Manton Gaulin and a pressure homogenizer, and a medium disperser such as a sand grinder, a Getzman mill and a diamond fine mill.

As the surfactant used here, the above-mentioned surfactants can be used.

In the salting-out / fusing step, the salting-out agent consisting of an alkali metal salt, an alkaline earth metal salt or the like in water in which the resin particles and the colorant particles are present is a coagulant having a critical coagulation concentration or more. Is added, and then heated to a temperature not lower than the glass transition point of the resin particles, thereby advancing salting out and simultaneously performing fusion. In this step, a method may be used in which an organic solvent that is infinitely soluble in water is added to substantially lower the glass transition temperature of the resin particles to effectively perform the fusion.

Examples of the alkali metal salts and alkaline earth metal salts which are salting-out agents include lithium, potassium and sodium as alkali metals, and magnesium, calcium, strontium and barium as alkaline earth metals. And preferably potassium, sodium, magnesium, calcium, or barium. Examples of the salt include chlorine salt, bromine salt, iodine salt, carbonate salt, and sulfate salt.

Further, as the organic solvent infinitely soluble in water, methanol, ethanol, 1-propanol,
2-propanol, ethylene glycol, glycerin,
Examples thereof include acetone, but alcohols having 3 or less carbon atoms such as methanol, ethanol, 1-propanol, and 2-propanol are preferable, and 2-propanol is particularly preferable.

When the fusion of the present invention is carried out by salting-out / fusion, it is preferable that the time after leaving the salting-out agent is left as short as possible. Although it is not clear as the reason for this, the agglomeration state of the particles varies depending on the standing time after salting out,
There arise problems that the particle size distribution becomes unstable and the surface property of the fused toner changes. The temperature at which the salting-out agent is added needs to be at least not higher than the glass transition temperature of the resin particles. The reason for this is that if the temperature at which the salting-out agent is added is equal to or higher than the glass transition temperature of the resin particles, salting-out / fusion of the resin particles will proceed promptly, but the particle size cannot be controlled, and thus large There arises a problem that particles having a particle size are generated. The range of this addition temperature may be not higher than the glass transition temperature of the resin, but is generally 5 ° C to 55 ° C, preferably 10 ° C to 45 ° C.

Further, in the present invention, it is preferable to use a method in which the salting-out agent is added at a temperature not higher than the glass transition temperature of the resin particles, and thereafter, the temperature is raised as quickly as possible and the temperature is raised to not lower than the glass transition temperature of the resin particles. The time required to raise the temperature is preferably less than 1 hour. Further, although it is necessary to raise the temperature rapidly, the rate of temperature increase is preferably 0.25 ° C./min or more. The upper limit is not particularly clear, but if the temperature is instantly raised, salting out will proceed rapidly, which makes it difficult to control the particle size, and is preferably 5 ° C./min or less.

[Tonerizing Step] In the tonerizing step, the toner particles obtained above may be used as they are. However, for the purpose of improving, for example, the fluidity, the charging property and the cleaning property, the above-mentioned external additives are used. Agents may be added. As a method for 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.

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 are added by a method in which the dispersion is added during the emulsion polymerization of the resin particles, a method in which the resin particles and the colorant particles are added at the same time as the salting-out / fusion step, and the particles are included in the toner, the resin particles themselves. It can be added by various methods such as a method of adding to. As a preferable method, a method of adding charge control agent particles and / or fixability improving agent particles in a dispersion state at the stage of emulsion polymerizing the above resin particles and the above salting out /
In the fusion step, a method in which charge control agent particles and / or fixability improving agent particles are added simultaneously with the resin particles and the colorant particles in the state of a dispersion and salting out / fusion is performed.

As the releasing agent, it is preferable to use various known releasing agents which can be dispersed in water. Specifically, olefin wax such as polypropylene and polyethylene, modified products thereof, natural wax such as carnauba wax and rice wax,
Examples thereof include amide wax such as fatty acid bisamide. It has already been mentioned that these are added as release agent particles and are preferably salted out / fused with the resin and the colorant.

Similarly, various charge control agents are known,
Moreover, the thing which can be disperse | distributed in water can be used. Specifically, nigrosine dyes, metal salts of naphthenic acid or higher fatty acids, alkoxylated amines,
Examples thereof include secondary ammonium salt compounds, azo-based metal complexes, salicylic acid metal salts or metal complexes thereof.

It is preferable that the particles of the releasing agent or the charge control agent have a number average primary particle diameter of about 10 to 500 nm in a dispersed state.

<< Developer >> The toner used in the present invention is
Although it may be used as a one-component developer or a two-component developer,
A two-component developer is preferred.

When used as a one-component developer, there is a method of using the toner as it is as a non-magnetic one-component developer, but usually, the toner particles contain magnetic particles of about 0.1 to 5 .mu.m. Used as a developer. As a method of containing it, it is common to incorporate it in the non-spherical particles in the same manner as the colorant.

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, alloys of these metals with metals such as aluminum and lead are used as the magnetic particles of the carrier. Ferrite particles are particularly preferable. The volume average particle diameter of the magnetic particles is 15
˜100 μm, more preferably 25 to 60 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 a magnetic particle 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. can be used. You can

<< Image Forming Method >> Next, the image forming method or apparatus of the present invention will be described.

FIG. 1 shows a schematic block diagram of the image forming apparatus of the present invention. Reference numeral 4 denotes a photoconductor drum, which is formed by forming an organic photoconductor (OPC), which is a photoconductor layer, on the outer peripheral surface of a drum base body made of aluminum, and rotates at a predetermined speed in the arrow direction. In this embodiment, the photosensitive drum 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 drum is uniformly charged in advance 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 photosensitive drum 4 and the recording material 8 are separated by a separator (separation pole) 9, but the toner development image is transferred and carried on the recording 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.

Although the recording 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 photoreceptor and the latent image is developed to obtain a visible image, image quality improvement, conversion, editing, etc. are easy and a high quality image is obtained. 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 that is optically modulated by a digital image signal from a computer or a copy manuscript 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 is a device for modulating and a device for directly modulating the laser intensity by using a semiconductor laser. These scanning optical systems perform spot exposure on a uniformly charged photoconductor to form a dot-shaped image.

The beam emitted from the above-mentioned scanning optical system has a circular or elliptical luminance distribution which has a skirt that spreads to the left and right and approximates a normal distribution. For example, in the case of a laser beam, it is usually the main beam 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 above-mentioned image forming apparatus is provided with the photosensitive drum 4
Alternatively, a process cartridge including at least one of the charging device 5, the developing device 6, the cleaning device 11 and the transfer device 7 may be mounted.

When the toner of the present invention is applied to a color image forming system, a system in which a single color image is formed on a photoconductor and sequentially transferred to a recording material (this system is referred to as a sequential transfer system and is shown in FIG. 2), or Examples of the method include a method of developing a single-color image on a photoconductor a plurality of times to form a color image, and then collectively transferring it to a recording material (this is referred to as a collective transfer method, which is shown in FIG. 3).

Here, 4 is a photosensitive drum, 5 is a charger, 6 is a developing device (developing unit), 11 is a cleaning device, 15 is a transfer drum, 16 is a transport unit, 17 is an attraction electrode, and 18 is Transfer pole, 19 is peeling pole, 20
Is a removing electrode, and 21 is a carrying section.

As the developer carrying member used in the present invention, a developing device in which a magnet is incorporated in the carrying member is used, and as the developer carrying member surface, aluminum or the surface is oxidized. Aluminum or stainless steel is used.

The toner image formed on the photoconductor by the various methods described above is transferred to a transfer material such as paper in a transfer process. The transfer method is not particularly limited, and various methods such as so-called corona transfer method and roller transfer method can be adopted.

[0131]

EXAMPLES Next, the embodiments of the present invention will be specifically described, but the present invention is not limited to these embodiments. In addition, "part" in a sentence represents a "weight part."

Example 1 Adeka Hope LS-90 (sodium n-dodecyl sulfate manufactured by Asahi Denka Co., Ltd.) was placed in a resin container having an internal volume of 20 L (liter).
0.90 kg and 10.0 L of pure water are put and dissolved by stirring.
1.20 kg of Regal 330R (carbon black manufactured by Cabot Corp.) is gradually added to this liquid under stirring, and well stirred for 1 hour after the addition. Then, using a sand grinder (medium type disperser), continuous dispersion was carried out for 20 hours.

After the dispersion, the particle size of the above dispersion was measured using an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd., and the weight average diameter was 122 nm. Further, the solid content concentration of the above dispersion liquid measured by a gravimetric method by static drying was 16.6% by weight. This dispersion is referred to as "colorant dispersion 1".

Sodium dodecylbenzenesulfonate (Kanto Chemical Co., Ltd.) 0.055 was placed in a 10 L stainless steel pot.
Kg was added, 4.0 L of ion-exchanged water was added, and dissolved by stirring at room temperature. This is referred to as anionic surfactant solution A.

0.014 kg of Newcol 565C (manufactured by Nippon Emulsifier Co., Ltd.) was placed in a 10 L stainless pot, 4.0 L of ion-exchanged water was added, and the mixture was stirred and dissolved at room temperature. This is referred to as a nonionic surfactant solution B.

223.8 g of potassium persulfate (manufactured by Kanto Chemical Co., Inc.) was placed in a 20 L hollow pot, and ion-exchanged water 1 was added.
Add 2.0 L and dissolve with stirring at room temperature. This is called initiator solution C.

In a 100 L GL (glass lining) reaction kettle equipped with a temperature sensor, a cooling pipe and a nitrogen introducing device, W
3.41 kg of AX emulsion (polypropylene emulsion having a number average molecular weight of 3000: number average primary particle size = 120 nm / solid content concentration = 29.9%), anionic surfactant solution A and nonionic surfactant solution B were put and stirred. To start. Next, 44.0 L of ion-exchanged water is added.

When heating is started and the liquid temperature reaches 75 ° C., the initiator solution C is added. After that, increase the liquid temperature to 75
While controlling the temperature at ± 1 ° C, 12.1 kg of styrene, 2.88 kg of n-butyl acrylate and 1.04 of methacrylic acid.
kg and 548 g of t-dodecyl mercaptan are added.

Further, the liquid temperature was raised to 80 ° C. ± 1 ° C.
The mixture was heated and stirred for an hour.

The liquid temperature is cooled to 40 ° C. or lower and stirring is stopped. Filter with a pole filter and use this latex-
It was set to A.

The resin particles in Latex-A had a glass transition temperature of 57 ° C., a softening point of 121 ° C., a molecular weight distribution of weight average molecular weight = 127,000, and a weight average particle diameter of 12.
It was 0 nm.

Into a new 10 L stainless pot, sodium dodecylbenzenesulfonate (Kanto Chemical Co., Ltd.) was added.
Add 55 kg, add 4.0 L of ion-exchanged pure water, and dissolve with stirring at room temperature. This is referred to as anionic surfactant solution D.

0.14 kg of Newcol 565C (manufactured by Nippon Emulsifier Co., Ltd.) was placed in a 10 L stainless pot, 4.0 L of ion-exchanged pure water was added, and the mixture was stirred and dissolved at room temperature. This is a nonionic surfactant solution E.

200.7 g of potassium persulfate (manufactured by Kanto Chemical Co., Inc.) was placed in a 20 L enamel pot, and ion-exchanged water 1 was added.
Add 2.0 l and dissolve at room temperature with stirring. This is an initiator solution F.

A WAX emulsion (polypropylene emulsion having a number average molecular weight of 3000: number average primary particle diameter = 120 nm) was placed in a 100 L GL reaction kettle equipped with a temperature sensor, a cooling tube, a nitrogen introducing device, and a comb-shaped baffle (the stirring blade is a Fowler blade). / Solid content concentration = 29.9%) 3.41
Then, kg, anionic surfactant solution D and nonionic surfactant solution E are added and stirring is started. Next, 44.0 L of ion-exchanged water is added.

When heating is started and the liquid temperature reaches 70 ° C., the initiator solution F is added. At this time, styrene 1
1.0 kg, n-butyl acrylate 4.00 kg, methacrylic acid 1.04 kg, and t-dodecyl mercaptan 9.
A solution prepared by mixing 02 g with the above is added.

Thereafter, the liquid temperature was controlled at 72 ° C. ± 2 ° C. and the mixture was heated and stirred for 6 hours. Furthermore, the liquid temperature is 80 ℃ ± 2 ℃.
And stirred for 12 hours under heating.

The liquid temperature is cooled to 40 ° C. or lower and stirring is stopped. After filtering through a pole filter, this filtrate was designated as latex-B.

The resin particles in Latex-B had a glass transition temperature of 58 ° C., a softening point of 132 ° C., a molecular weight distribution of weight average molecular weight = 245,000, and a weight average particle diameter of 12.
It was 0 nm.

5.36 kg of sodium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) as a salting-out agent and 20.0 L of ion-exchanged water are put in a 35 L stainless steel pot, and dissolved by stirring. This is designated as sodium chloride solution G.

FC-170C in a 2L glass beaker
(Sumitomo 3M, nonionic surfactant) 1.00
g, add 1.00 L of ion-exchanged water, and dissolve with stirring. This is referred to as a nonionic surfactant solution H.

Two latex-A's prepared above were placed in a 100 L SUS reaction kettle equipped with a temperature sensor, a cooling tube, a nitrogen introducing device, and a comb-shaped baffle (the stirring blade is an anchor blade).
0.0 kg, 5.2 kg of Latex-B, 0.4 kg of Colorant Dispersion Liquid 1 and 20.0 kg of deionized water are added and stirred. Then, the mixture was heated to 40 ° C., sodium chloride solution G, isopropanol (Kanto Chemical Co., Ltd.) 6.00 k
g, and nonionic surfactant solution H are added in this order. Then, after leaving it for 10 minutes, the temperature rise is started and the liquid temperature becomes 8
The temperature is raised to 5 ° C. in 60 minutes. At a liquid temperature of 85 ° C ± 2 ° C,
Heat and stir for 6 hours for salting out / fusion. Then, the temperature is cooled to 40 ° C. or lower and stirring is stopped. The mixture is filtered through a sieve having an opening of 45 μm, and this filtrate is used as an association liquid.

Then, using a Nutsche, wet cake-like non-spherical particles were collected by filtration from the association liquid. Then, it was washed with ion-exchanged water.

The wet cake-shaped non-spherical particles, which have been washed as above, are taken out from the nutsche, and the whole paper vat 5
Spread it while breaking it into pieces. After covering with kraft paper, it was dried for 100 hours by a blow dryer at 40 ° C.

The dried block-shaped non-spherical particles were crushed with a Henschel crusher.

The non-spherical particles thus obtained are referred to as "non-spherical particles 1".

Example 2 In the anionic surfactant solution A of Example 1, the addition amount of sodium dodecylbenzene sulfonate was 0.03.
The non-spherical particles of the present invention were obtained in the same manner except that the amount of Newcoal 565C added was 0.007 kg in the nonionic surfactant solution B.

This is designated as "aspherical particle 2".

Example 3 In the anionic surfactant solution A of Example 1, the addition amount of sodium dodecylbenzene sulfonate was 0.01.
The non-spherical particles of the present invention were obtained in the same manner except that the amount of Newcoal 565C added in the nonionic surfactant solution B was 0.0035 kg.

This is designated as "aspherical particle 3".

Example 4 "Aspherical particle 4" was obtained in the same manner as in Example 1 except that the temperature at the time of association was 95 ° C and the association time was 7 hours.

Example 5 "Aspherical particle 5" was obtained in the same manner as in Example 1 except that the association time was 4 hours.

Example 6 "Aspherical particle 6" was obtained in the same manner as in Example 1 except that the temperature at the time of association was 75 ° C.

Example 7 The following components were added to a 100 L GL reaction kettle (stirring blade was a Faudler blade) equipped with a temperature sensor, a cooling tube, a nitrogen introducing device and a comb-shaped baffle.

Styrene 60 parts Butyl acrylate 40 parts Acrylic acid 8 parts Water 100 parts Nonionic emulsifier (Emulgen 950) 1 part Anion emulsifier (Neogen R) 1.5 parts Potassium persulfate 0.5 parts While stirring the above aqueous solution 70 Polymerization was performed at 8 ° C. for 8 hours to obtain an acidic polar group-containing resin emulsion (latex 4) having a solid content of 50%. The weight average particle size of the resin particles in the latex is 150 nm.

Toner Preparation Latex 4 120 parts Carbon Black (Regal 330R) 5 parts Chromium dye (Bontron-E81) 1 part Water 200 parts The above mixture is dispersed and stirred with a slasher for about 30 parts.
The temperature was kept at 2 ° C for 2 hours. Then, with further stirring, 70 ℃
It was heated to and held for 3 hours. The liquid dispersion obtained by cooling was subjected to Buchner filtration, washed with water, and vacuum dried at 50 ° C. for 10 hours to obtain non-spherical particles.

This is designated as "aspherical particle 7".

In Table 1 below, the above non-spherical particles 1 to 3 and 7 are used.
The weight average particle diameter of the resin particles used in the production of is shown.

[0169]

[Table 1]

Comparative Example 1 Styrene 165 g, n-butyl acrylate 35 g, phthalocyanine blue 10 g, di-t-butyl salicylate metal compound 2 g, styrene / methacrylic acid copolymer 8
60 g of paraffin wax (mp = 70 ° C.)
The mixture was heated to ℃ and uniformly dissolved and dispersed at 12000 rpm with a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), and 10 g of 2,2′-azobis (2,4-valeronitrile) as a polymerization initiator was dissolved therein. Was added and dissolved to prepare a polymerizable monomer composition. Then add 0.1 to 710 g of deionized water.
450 g of an aqueous M sodium phosphate solution was added, and 68 g of 1.0 M calcium chloride was gradually added while stirring at 12000 rpm with a TK homomixer to prepare a suspension in which tricalcium phosphate was dispersed.

The above polymerizable monomer composition was added to this suspension, and the mixture was stirred with a TK homomixer at 10,000 rpm for 20 minutes to granulate the polymerizable monomer composition. Then 8
The reaction was carried out at 0 ° C for 10 hours. The tricalcium phosphate was dissolved and removed with hydrochloric acid, and then filtered, washed and dried to obtain colored particles having a volume average particle diameter of 7.9 μm. This is designated as "Comparative Particle 1".

Comparative Example 2 100 parts of styrene / acrylic resin, carbon black 1
0 parts, low molecular weight polypropylene (number average molecular weight = 300
0) 4 parts are melted, kneaded and pulverized to have a volume average particle size of 6.
Colored particles of 9 μm were obtained. This is "Comparative Particle 2"
And

(Evaluation) First, the volume average particle diameter and shape factor of non-spherical particles are shown.

[0174]

[Table 2]

External additives shown in Tables 3 and 4 below were added to the above non-spherical particles.

[0176]

[Table 3]

[0177]

[Table 4]

Silica A: Hexamethyldisilazane treatment (number average primary particle diameter = 150 nm) Silica B: Hexamethyldisilazane treatment (number average primary particle diameter = 250 nm) Titanium oxide A: Hexyltrimethoxysilane treatment ( Number average primary particle diameter = 150 nm) -Titanium oxide B: octyltrimethoxysilane treatment (number average primary particle diameter = 250 nm) -Strontium titanate A: Number average primary particle diameter = 36
0 nm-Strontium titanate B: number average primary particle size = 85
0 nm P-MMA (organic fine particles A): number average primary particle diameter = 1
200 nm P-MMA (organic fine particles B): number average primary particle size = 6
00 nm Silica C: Hexamethyldisilazane treatment (number average primary particle diameter = 10 nm) Silica D: Dichlorodimethylsilane treatment (number average primary particle diameter = 17 nm) Further, a volume average of these toners and styrene / acrylic resin coated. A ferrite carrier having a particle diameter of 45 μm was mixed to prepare a developer having a toner concentration of 6%, which was used for printing evaluation. These developers correspond to the toners, respectively, "Developer 1 for the present invention" to "Developer 14 for the present invention",
These are referred to as "Comparative developer 1" to "Comparative developer 3".

Evaluation (Contact Development Method) Using a digital copying machine Konica 7033 manufactured by Konica Corporation, the copying speed was further modified to A4, 30 sheets / minute, and the actual copying evaluation was carried out. The conditions are shown below. A laminated organic photoconductor was used as the photoconductor.

(Photoreceptor) As a photoreceptor, a photoreceptor for a Konica 7033 digital copying machine manufactured by Konica Corporation (diameter = 60)
mm photosensitive drum, an aluminum support (base), and an intermediate layer, a charge generation layer, and a charge transport layer in this order).

The constitution of the photoreceptor is shown below.

Subbing; titanium chelate compound TC-750
(Matsumoto Pharmaceutical Co., Ltd.) / Silane coupling agent KBM503
(Shin-Etsu Chemical Co., Ltd.) = 2 / 1.3 propanol solution was applied. The dry film thickness was 1.0 μm.

Charge generation layer: titanyl phthalocyanine / silicone modified butyral (KR5254 manufactured by Shin-Etsu Chemical) =
The dry film thickness was 0.3 μm at a ratio of 1/1.

Charge transport layer; α-phenyl stilbene type charge transport material / polycarbonate Z = 2/3, and the dry film thickness was 28 μm.

Development conditions DC bias: -500V Dsd (distance between photoconductor and developing sleeve); 600 μm developer layer regulation; magnetic H-Cut system developer layer thickness: 700 μm developing sleeve diameter; 40 mm Untransferred toner has a thickness of 3.0 mm
The method of cleaning with the urethane rubber blade of was adopted.

As a recording material to be used, plain paper having a continuous weight of 55 kg was used, and an image was formed in the longitudinal direction. The image forming conditions are low temperature and low humidity environment (10 ° C., 15% RH).
Also, printing evaluation was carried out using the above-mentioned developer under two kinds of environmental conditions of high temperature and high humidity environment (30 ° C., 80% RH). For printing, pixels having a low pixel ratio of 2% were used, and in the intermittent mode, a pause was made for each sheet, and a total of 50,000 sheets were printed. The print quality of the images before and after 50,000 sheets was compared. Further, the presence or absence of image defects in the images after 50,000 sheets were visually determined.

The criteria for judgment are as follows.

Rank A: No image defect Rank B: Less than 5 black spots of 0.5 mm or less exist in solid white image Rank C: 5 or more black spots of 0.5 mm or less exist in solid white image Rank D: Black spots over 0.5 mm are solid white images 5
For the evaluation of the image quality of the presence of more than one image, image density and fog density were compared. RD-918 manufactured by Macbeth was used as the highest image density, and the absolute reflection density was compared. Fog was compared by the relative reflection density when the density of the paper was "0".

The results are shown below.

[0190]

[Table 5]

[0191]

[Table 6]

Developers in the present invention (Developers 1 to 1 for the present invention
It can be seen that all of 4) use good characteristics even after forming 50,000 images.

[0193]

According to the present invention, a toner for developing an electrostatic latent image capable of forming a stable image without a decrease in the maximum density or the occurrence of fog even when used for a long period of time and without the occurrence of image defects, and An image forming method and an image forming apparatus using the same can be provided.

[Brief description of drawings]

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

FIG. 2 is a schematic configuration diagram of a sequential transfer system to which the present invention can be applied.

FIG. 3 is a schematic configuration diagram of a batch transfer system to which the present invention can be applied.

[Explanation of symbols]

1 Semiconductor laser light source 2 polygon mirror 3 fθ lens 4 photoconductor drum 5 charger 6 developer 7 Transfer device 8 recording materials 9 separation poles 10 Fixing device 11 Cleaning device 12 Pre-charge exposure (PCL) 13 Cleaning blade 15 Transfer drum

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroyuki Yamada 2970 Ishikawa-cho, Hachioji-shi, Tokyo Inside Konica Co., Ltd. (56) References JP 10-20552 (JP, A) JP 9-244298 ( JP, A) JP-A-5-100481 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 9/08

Claims (8)

(57) [Claims] 1. A toner for developing an electrostatic latent image, comprising at least colored particles obtained by fusing resin particles in an aqueous medium and an external additive, wherein the external additive has a number average of 50 to 5000 nm. Number average primary particle diameter (Anm) of large particle size external additive having primary particle diameter and weight average particle diameter (Bnm) of the resin particles
And the following relationship (1) between
The shape factor represented by (2) is within the range of 1.3 to 2.2.
A toner for developing an electrostatic latent image, which is characterized by being present. (1) 0.1 ≦ B / A ≦ 1.0 B = 50 to 2000 (2) Shape factor = ((maximum diameter / 2) ² × π) / projected area 2. The toner for developing an electrostatic latent image according to claim 1, wherein the external additive is organic fine particles. 3. The toner for developing an electrostatic latent image according to claim 1, wherein the external additive is a titanate compound. 4. The toner for developing an electrostatic latent image according to claim 1, wherein the external additive is titanium oxide. 5. The toner for developing an electrostatic latent image according to claim 1, wherein the external additive is silica. 6. The toner for developing an electrostatic latent image has a volume average particle diameter of 3 to 9 μm , and the toner having a shape factor of 1.5 to 2.0 is 80% by number or more. The toner for developing an electrostatic latent image according to any one of claims 1 to 5, wherein: 7. An image forming method of transferring an unfixed toner image formed on a photosensitive member through a process of uniform charging, image exposure and development to a recording material and then fixing the toner image, wherein at least resin particles are used as a developer. An electrostatic latent image developing toner comprising colored particles fused in an aqueous medium and an external additive is used, and a large particle diameter external additive having a number average primary particle diameter of 50 to 5000 nm among the external additives is used. The following relationship between the number average primary particle diameter (Anm) of the agent and the weight average particle diameter (Bnm) of the resin particles
(1) and the shape of the toner represented by the following formula (2)
An image forming method, wherein the coefficient is within the range of 1.3 to 2.2 . (1) 0.1 ≦ B / A ≦ 1.0 B = 50 to 2000 (2) Shape factor = ((maximum diameter / 2) ² × π) / projected area 8. An image forming apparatus for transferring an unfixed toner image formed on a photosensitive member through uniform charging, image exposure, and development steps onto a recording material and then post-fixing it, wherein at least resin particles are used as a developer. An electrostatic latent image developing toner comprising colored particles fused in an aqueous medium and an external additive is used, and a large particle diameter external additive having a number average primary particle diameter of 50 to 5000 nm among the external additives is used. The following relationship (1) between the number average primary particle diameter (Anm) of the agent and the weight average particle diameter (Bnm) of the resin particles:
And the shape factor represented by the following formula (2) of the toner is
An image forming apparatus characterized by being in the range of 1.3 to 2.2 . (1) 0.1 ≦ B / A ≦ 1.0 B = 50 to 2000 (2) Shape factor = ((maximum diameter / 2) ² × π) / projected area