JP2002040711A - Toner and image forming method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymerized toner which is excellent in fixation, suppresses the occurrence of odor and has a small-grain size. SOLUTION: It is a feature of this toner that the toner is made at least by salting out and fusing resin particles and colorant, has a volume average grain size of 3-8 μm and has the average value of shape factor of 0.930-0.980 expressed by the following Formula 1 and the resin particles are obtained by means of emulsion polymerization method or mini-emulsion polymerization method using carbon tetrabromide as a chain transfer agent: shape factor = circumferential length calculated from diameter corresponding to circle / circumferential length of particle projection... (Formula 1).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic toner and an image forming method using the same.

[0002]

2. Description of the Related Art In recent years, image forming techniques such as copying machines, printers, and facsimile machines have been remarkably developed, and the most frequently used one belongs to an electrostatic image forming method represented by an electrophotographic system. It is.

[0003] The reason is that an electrostatic image forming method such as an electrophotographic method can obtain a high-quality image at a high speed, can form not only a monochrome image but also a color image, and has a durability that can withstand long-term use. , And stability. However, as the performance of related technologies such as personal computers has improved, the required performance level has been increasing year by year, and further improvement and performance improvement are required to satisfy the demand.

In this electrophotographic method, it is necessary to fix the formed toner image on the surface of a recording material (image support) such as paper. As the fixing method, fixing by pressure and fixing by heat are known. In the fixing method using pressure, it is difficult to improve the adhesiveness to paper or the like.
Poor practicality, so-called hot-melt fixing method, in which toner is fixed by melting the toner by heat, is widely used at present. The thermal fusion fixing method is roughly classified into a flash fixing method which is a non-contact fixing method and a heat roll and heat belt fixing method which is a contact fixing method. A heat roll and a heat belt fixing method are effective for an electrophotographic copier printer or the like that outputs a high-speed image because high heat efficiency can be expected because toner is melted by bringing a heat transfer member into contact with a toner image. Since the heat transfer member is in direct contact with the melted toner image, a part of the toner image adheres to and transfers to the heat transfer member and re-transfers to the next fixing sheet to contaminate the image. There is a disadvantage that.

On the other hand, from the viewpoint of fixability, it is necessary to control the molecular weight distribution of the resin used in the toner. For example, in order to suppress high-temperature offset, it is necessary to improve the elastic modulus at high temperature, and for that purpose, it is preferable to increase the high molecular weight component. Alternatively, in order to improve the adhesiveness to an image forming support such as paper, it is preferable to increase the low molecular weight component. In order to satisfy such contradictory functions with a single resin, it is necessary to expand the molecular weight distribution.

[0006] Further, it is desired to reduce the particle size of the toner from the viewpoint of high image quality. In recent years, as a method for producing a small particle size toner, a toner using a polymerization method has been devised. In this polymerization method toner, a method of preparing an amorphous toner by associating or salting out / fusing resin particles and colorant particles as needed, or dispersing a radical polymerizable monomer and a colorant, Next, there is a method in which droplets are dispersed in an aqueous medium or the like so as to have a desired toner particle diameter, and suspension polymerization is performed.

In the resins prepared by any of the methods,
As described above, it is necessary to control the molecular weight distribution in order to improve the fixing property. As one of methods for controlling the molecular weight distribution, a method of reducing the molecular weight by using a chain transfer agent is known, and mercaptans, particularly dodecyl mercaptan are widely used as a suitable chain transfer agent. . However, this mercaptan-based compound has a peculiar odor, and in particular, causes a problem that the chain transfer agent remaining at the time of heat fixing is volatilized and odor is generated.
This problem of odor has not been particularly regarded as a problem in a so-called pulverization method toner in which a resin and a colorant are melted, kneaded, and pulverized. Improvements are required.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a first object of the present invention is to provide a polymerized toner having a small particle size toner which suppresses generation of odor during heat fixing. A second object is to provide a toner having a small particle size and excellent fixability.

[0009]

The above object of the present invention has been attained by the following constitutions.

[0010] 1. In a toner obtained by salting out / fusing at least resin particles and a colorant, the volume average particle size is 3 to 8
μm, and the average value of the shape factor represented by the formula 1 is 0.930 to 0.980, and the resin particles are emulsion polymerization or miniemulsion polymerization using carbon tetrabromide as a chain transfer agent. A toner characterized in that it is obtained by:

2. An image forming method for thermally fixing a toner image on an image support formed by a toner obtained by salting out / fusing at least resin particles and a colorant, wherein the toner has a volume average particle size of 3 to 8 μm, and The average value of the shape factor represented by the formula 1 is 0.930 to 0.980,
An image forming method, wherein the resin particles are obtained by an emulsion polymerization method or a miniemulsion polymerization method using carbon tetrabromide as a chain transfer agent.

The present inventors have conducted intensive studies on the above problems, and as a result, have clarified the essential difference between the kneading method and the polymerization method of the toner, thereby completing the present invention. . That is, in a so-called pulverization method toner, a resin and a colorant are melt-kneaded, and then pulverized and classified to form a toner. In this step, the resin is heated to a melting temperature or higher, and at the same time, a large share is applied to a kneading device such as a twin screw extruder. As a result, the molecular chains of the resin are cut, and an effect higher than the desired fixing property is obtained.
Further, the chain transfer agent present in the resin is vaporized by the heat at the time of kneading, so that almost no single substance can be present alone in the final toner. On the other hand, in the case of a so-called polymerization toner, when the toner is prepared by a radical polymerization method without going through the melt-kneading step, the boiling point of water is 1 at the maximum.
The heating is limited to about 00 ° C. As a result, it was presumed that a trace amount of the chain transfer agent remained and was vaporized at the temperature at the time of fixing, causing an odor problem. In the present invention, it has been found that the use of a chain transfer agent having a low odor as the chain transfer agent itself is essential for the polymerization method toner.

[Resin particles, toner] In the present invention,
In a toner obtained by salting out / fusing resin particles and a colorant, the toner has a volume average particle diameter of 3 to 8 μm, and the average value of the shape factor represented by the above formula 1 is 0.930 to 0.1. 9
80, wherein the resin particles are obtained by an emulsion polymerization method or a miniemulsion polymerization method using carbon tetrabromide as a chain transfer agent.

First, the resin particles and toner of the present invention will be described. As a method of fusing resin particles in an aqueous medium, for example, methods described in JP-A-63-186253, JP-A-63-282749, JP-A-7-146583, and the like, And a method of forming by fusion / fusion. The resin particles containing a release agent used in the production of the toner of the present invention preferably have a mass average particle size of 50 to 2,000 nm, and the production methods of these resin particles are generally emulsion polymerization, suspension polymerization, and dispersion polymerization. It is possible to use a mixed method, a precipitation polymerization method, an interfacial polymerization method, pulverized fine resin particles after synthesis, and the like, but in the present invention, it is characterized by resin particles obtained by an emulsion polymerization method or a miniemulsion polymerization method. And particularly preferably a miniemulsion polymerization method.

The emulsion polymerization method referred to in the present invention refers to a method of mechanically dispersing a monomer in the presence of an emulsifier (also referred to as a surfactant) at a concentration higher than a critical micelle forming concentration (hereinafter abbreviated as CMC). Emulsification, a water-soluble polymerization initiator is mainly added, polymerization is carried out to form resin fine particles, and then resin particles having a desired size are produced by association. The mini-emulsion polymerization method is a form of the emulsion polymerization method, and is a method of emulsifying at an emulsifier concentration of CMC or less. The polymerization initiator used at this time may be either water-soluble or oil-soluble. For example, an oil-soluble polymerization initiator or a functional compound is allowed to coexist with a polymerizable monomer, and CMC
This is a method of performing dispersion and polymerization in the presence of the following concentration of an emulsifier. In this case, the subsequent association step may be used or omitted. By using this method, molecular diffusion of the functional additive and the like in the monomer particles is suppressed, and the polymerization proceeds only in the monomer oil droplets. Therefore, the fine particles and the desired additive are surely contained in the monomer particles. Can be obtained, which is particularly preferable.

Specifically, in each of the above polymerization methods, a monomer solution in which a chain transfer agent and, if necessary, a release agent are dissolved is dispersed in an aqueous medium, and the molecular weight is adjusted by the chain transfer agent by each polymerization method. Performed, if necessary, a step of preparing resin particles containing a release agent, a step of fusing the resin particles in an aqueous medium using the resin particle dispersion, the resulting particles from the aqueous medium It comprises a washing step of filtering and removing 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 drying. Here, the resin particles may be colored particles. In addition, non-colored particles can also be used as resin particles.In this case, color particles are obtained by adding a colorant particle dispersion or the like to a dispersion of resin particles and then fusing the dispersion in an aqueous medium. Can be.

In particular, one of the features of the present invention is to use a method of salting out / fusion using resin particles produced in the polymerization step. When non-colored resin particles are used, the resin particles and the colorant particles can be salted out / fused in an aqueous medium.

Here, the aqueous medium is composed of water as a main component and has a water content of 50% by mass or more. Examples of the solvent other than water include an organic solvent soluble in water, such as methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran. Preferably an organic solvent that does not dissolve the resin,
Alcohol organic solvents such as methanol, ethanol, isopropanol and butanol are particularly preferred.

The disperser for performing the emulsification and dispersion is not particularly limited, and examples thereof include Clearmix, an ultrasonic disperser, a mechanical homogenizer, a Menton-Gaulin and a pressure homogenizer. .

The colorant itself may be used after surface modification. In the method for modifying the surface of the colorant, the colorant is dispersed in a solvent, the surface modifier is added thereto, and then the temperature is raised and the reaction is performed. After the completion of the reaction, the mixture is filtered, washed with the same solvent, and repeatedly 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 performed in a state where the surfactant concentration in water is equal to or higher than the critical micelle concentration (CMC).

The disperser used for dispersing the pigment is not particularly limited, but is preferably a CLEARMIX, an ultrasonic disperser, a mechanical homogenizer, a pressure disperser such as a Menton-Gaulin or a pressure type homogenizer, a sand grinder, a Getzman mill or a diamond fine. A media type disperser such as a mill may be used.

As the surfactant used here, the above-mentioned surfactants can be used. In the salting-out / fusion step, a salting-out agent composed of an alkali metal salt or an alkaline earth metal salt is added as a coagulant having a critical coagulation concentration or more in water in which resin particles and colorant particles are present. Then, the step of heating the resin particles to a temperature equal to or higher than the glass transition point to promote salting out and simultaneously perform fusion.

Here, the alkali metal salt and alkaline earth metal salt as salting-out agents include lithium, potassium, sodium and the like as alkali metals, and magnesium, calcium, strontium, barium and the like as alkaline earth metals. And preferably potassium, sodium, magnesium, calcium and barium. Examples of the salt include chloride, bromide, iodine, carbonate, sulfate and the like.

When the fusion of the present invention is carried out by salting out / fusing, it is preferable to minimize the time of standing after adding the salting out agent. Although the reason for this is not clear, the aggregation state of the particles fluctuates depending on the standing time after salting out,
There are problems that the particle size distribution becomes unstable and the surface properties of the fused toner fluctuate. The temperature at which the salting-out agent is added is not particularly limited.

Further, in the present invention, it is preferable to use a method in which the temperature of the dispersion of the resin particles is raised as quickly as possible, and the dispersion is heated to the glass transition temperature or higher of the resin particles. The time until the temperature rise is less than 30 minutes, preferably less than 10 minutes. Further, it is necessary to raise the temperature quickly, but the rate of temperature increase is preferably 1 ° C./min or more. The upper limit is not particularly clear, but is preferably 15 ° C./min or less from the viewpoint of suppressing generation of coarse particles due to rapid progress of salting out / fusion. As a particularly preferred embodiment, there can be mentioned a method in which salting-out / fusion is continued even when the temperature exceeds the glass transition temperature. By using this method, the fusion can be effectively advanced together with the growth of the particles, and the durability as a final toner can be improved.

Here, one of the features of the present invention is that the particle size of the toner obtained by fusing according to the present invention is 3 to 8 μm in volume average particle size. These toners have a volume average particle diameter of Coulter Counter TA-II, Coulter Multisizer (all manufactured by Coulter Inc.), SLAD110
0 (Shimadzu Corporation laser diffraction particle size analyzer) or the like. Coulter counter T
In A-II and Coulter Multisizer, an aperture of 100 μm was used as the aperture diameter, and 2.0 μm was used.
The particle size distribution in the range of ４０40 μm can be measured and determined.

Further, as for the toner, the amount of fine powder toner of 3.0 μm or less is preferably 20% by number or less in the number distribution, more preferably 10% by number or less of 2.0 μm or less. This fine powder toner amount is
It can be measured using an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd. In order to adjust the particle size distribution to this range, it is preferable to narrow the temperature control in the salting-out / fusion step. Specifically, it is to raise the temperature as quickly as possible, that is, to increase the temperature.

The shape of the toner obtained by fusing has an average value (average circularity) of the shape factor represented by the above-mentioned formula (1) of 0.930 to 0.980. And preferably 0.940 to 0.975.

It is preferable that the shape factor distribution of the toner is sharp, and the standard deviation of the circularity is 0.10.
The following is preferred, and the CV value calculated by the following formula is preferably less than 20%, more preferably less than 10%.

CV value (%) = (standard deviation of circularity / average circularity) × 100 By setting the average circularity to 0.930 to 0.980, the shape of the toner can be made somewhat irregular. As a result, heat transfer can be made more efficient, and as a result, the fixability can be further improved. That is, the fixing property can be improved by setting the average circularity to 0.980 or less. In addition, by setting the average circularity to 0.930 or more, the degree of irregularity of the particles can be suppressed, and the crushability of the particles due to stress during long-term use can be suppressed.

Further, it is preferable that the distribution of the shape factor is sharp, and the standard deviation of the circularity is set to 0.10 or less to obtain a toner having a uniform shape. Since the number can be reduced, the effect of preventing the fixing device from being contaminated by improving the fixing rate and reducing the offset property is further exhibited. When the CV value is also less than 20%, a sharp shape distribution can be similarly obtained, and the effect of improving the fixing property can be more remarkably exhibited.

The method for measuring the shape factor is not limited. For example, a photograph in which the toner particles are magnified 500 times with an electron microscope is taken, and 500 images are taken using an image analyzer. Shape factor (circularity) of toner
Is measured, and the arithmetic average value is obtained, whereby the average value (average circularity) of the shape coefficients can be calculated. Also,
As a simple measurement method, it can be measured by FPIA-1000 (manufactured by Toa Medical Electronics Co., Ltd.).

[Charge Control Agent] In the toner, besides the colorant and the release agent, a material capable of imparting various functions as a toner material can be added. Specific examples include a charge control agent. These components can be added simultaneously with the resin particles and the colorant particles in the above-mentioned salting-out / fusion step, and can be added by various methods such as a method of including in the toner and a method of adding to the resin particles themselves.

As the charge control agent, various known charge control agents which can be dispersed in water can be used. Specific examples include a nigrosine dye, a metal salt of naphthenic acid or a higher fatty acid, an alkoxylated amine, a quaternary ammonium salt compound, an azo metal complex, a metal salt of salicylic acid, and a metal complex thereof.

[Chain Transfer Agent] The resin particles of the present invention are characterized by being prepared by emulsion polymerization or miniemulsion polymerization using carbon tetrabromide as a chain transfer agent.

The chain transfer agent is generally used for the purpose of adjusting the molecular weight of the resin particles. Conventionally, as the chain transfer agent, for example, octyl mercaptan, dodecyl mercaptan, tert-dodecyl mercaptan, etc. The present invention is characterized in that carbon tetrabromide is used.

By using carbon tetrabromide as the chain transfer agent, the chain transfer agent is uniformly present in the toner, and the carbon tetrabromide itself has a boiling point of 190 ° C., a melting point as high as 80 ° C., and a solid. By exhibiting the function as a plasticizer, the fixability can be improved. The toner has a shape with irregularities on the surface from the time of toner production, and furthermore, because it fuses in an aqueous medium, there is little difference in the shape and surface properties between the particles. Since toner particles tend to be uniform, there is little difference in fixability between toners, and good fixability can be maintained. Further, when the toner has the above-described structure, the volatile components are easily scattered from the surface, and as a result, the odor is more severely restricted. In such a situation, the carbon tetrabromide of the present invention is used. Its use is extremely effective. The amount of carbon tetrabromide used in the present invention is preferably 0.01 to 5% by mass per resin particle.

[Release Agent] The toner used in the present invention comprises:
It is preferable that the toner is obtained by fusing resin particles containing a release agent in an aqueous medium. In this manner, the resin particles in which the release agent is encapsulated in the resin particles are salted out / fused with the colorant particles in an aqueous medium, whereby a toner in which the release agent is finely dispersed can be obtained.

As the release agent, it is preferable to use a compound represented by the following formula. R ^1- (OCO-R ² ) _{n In the} formula, n is an integer of 1 to 4, preferably 2 to 4, more preferably 3 to 4, and particularly preferably 4. R ¹ , R
² represents a hydrocarbon group which may have a substituent. R ¹
Has 1 to 40 carbon atoms, preferably 1 to 20 carbon atoms, and more preferably 2 to 5 carbon atoms. R ² has 1 to 40 carbon atoms, preferably 16 to 30 carbon atoms, and more preferably 18 to 26 carbon atoms.

Next, examples of typical compounds are shown below.

[0041]

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[0042]

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The addition amount of the above compound is 1 to 30% by mass, preferably 2 to 20% by mass, more preferably 3 to 15% by mass based on the whole toner.

The toner of the present invention is preferably prepared by encapsulating the above-mentioned release agent in resin particles by miniemulsion polymerization, salting out and fusing together with the colored particles.

Next, materials of the resin particles and the toner other than those described above will be described. [Monomer] As the polymerizable monomer, a radical polymerizable monomer is an essential component, and a crosslinking agent can be used as necessary. It is preferable that at least one of the following radical polymerizable monomers having an acidic group or a radical polymerizable monomer having a basic group is contained.

(1) Radical polymerizable monomer The radical polymerizable monomer component is not particularly limited, and a conventionally known radical polymerizable monomer can be used. Also, to satisfy the required characteristics,
Species or a combination of two or more can be used.

Specifically, aromatic vinyl monomers, (meth) acrylate monomers, vinyl ester monomers, vinyl ether monomers, monoolefin monomers, diolefin monomers Monomers, halogenated olefin monomers and 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- Styrene-based monomers such as octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, 2,4-dimethylstyrene, and 3,4-dichlorostyrene, and derivatives thereof. .

The (meth) acrylate monomers include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, and ethyl methacrylate. Butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-aminoacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and the like.

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

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

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

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

Examples of the halogenated olefin monomer 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 properties of the toner. Examples of the radical polymerizable crosslinking agent 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, and a quaternary ammonium salt may be used. it can. As the carboxylic acid group-containing monomer, for example, acrylic acid,
Methacrylic acid, fumaric acid, maleic acid, itaconic acid,
Cinnamic acid, monobutyl maleate, monooctyl maleate and the like can be 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 the above four compounds. Quaternary ammonium salt, 3-dimethylaminophenyl acrylate, 2-hydroxy-3-methacryloxypropyltrimethylammonium salt, acrylamide,
N-butylacrylamide, N, N-dibutylacrylamide, piperidylacrylamide, methacrylamide, N-butylmethacrylamide, N-octadecylacrylamide; vinylpyridine, vinylpyrrolidone; vinyl N-methylpyridinium chloride, vinyl N-ethylpyridinium chloride, N , N-diallylmethylammonium chloride, N, N-diallylethylammonium chloride and the like.

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 0.1 to 15% of the whole monomer. The radical polymerizable cross-linking agent is preferably used in an amount of 0.1 to 10% by mass with respect to the total radical polymerizable monomer, although it depends on its properties.

[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 (eg, potassium persulfate, ammonium persulfate, etc.), azo compounds (eg, 4,4 ′)
-Azobis-4-cyanovaleric acid and salts thereof, 2,2'-azobis (2-amidinopropane) salts and the like), peroxide compounds and the like. Further, the above radical polymerization initiator can be used as a redox initiator in combination with a reducing agent, if necessary. The use of a redox initiator is preferable because the polymerization activity is increased, the polymerization temperature can be reduced, and the polymerization time can be further shortened.

As the polymerization temperature, any temperature may be selected as long as it is equal to or higher than the minimum radical generation temperature of the polymerization initiator, but for example, a range of 50 ° C. to 90 ° C. is used. However, by using a polymerization initiator started at room temperature, for example, a combination of hydrogen peroxide and a reducing agent (such as ascorbic acid), polymerization can be performed at room temperature or higher.

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

Examples of the ionic surfactant include sulfonates (sodium dodecylbenzenesulfonate,
Sodium arylalkyl polyether sulfonate,
3,3-disulfonediphenylurea-4,4-diazo-
Sodium bis-amino-8-naphthol-6-sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol -6
Sodium sulfonate), sulfate salts (sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc.),
Fatty acid salts (sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, calcium oleate, etc.) are exemplified.

Further, a nonionic surfactant can also be used. Specifically, for example, polyethylene oxide, polypropylene oxide, a combination of polypropylene oxide and polyethylene oxide, an ester of polyethylene glycol and higher fatty acid, an alkylphenol polyethylene oxide, an ester of higher fatty acid and polyethylene glycol, an ester of higher fatty acid and polypropylene oxide, And sorbitan esters.

In the present invention, these are mainly used as emulsifiers at the time of emulsion polymerization, but they may be used in other steps or for other purposes.

[Molecular Weight of Binder Resin] The binder resin used includes a high molecular weight component having a peak or shoulder in a molecular weight region of 100,000 to 1,000,000,
Resins containing both low molecular weight components having peaks or shoulders in the range of 0 to 20,000 are particularly preferred.

The molecular weight of the resin is preferably measured by GPC (gel permeation chromatography) using THF (tetrahydrofuran) as a solvent. That is, 1.0 ml of THF is added to 0.5 to 5 mg, more specifically, 1 mg of a measurement sample, and the mixture is stirred at room temperature using a magnetic stirrer or the like to be sufficiently dissolved. Then, after treating with a membrane filter having a pore size of 0.45 to 0.50 μm, the mixture is injected into GPC.
GPC measurement conditions were as follows: stabilize the column at 40 ° C,
THF is flowed at a flow rate of 1.0 ml per minute, and about 100 μl of a sample having a concentration of 1 mg / ml is injected to measure. The column is preferably used in combination with a commercially available polystyrene gel column. For example, Showa Denko Sho
dex GPCKF-801, 802, 803, 80
4, 805, 806, 807, and TSKgel G1000H, G2000H, G3000 manufactured by Tosoh Corporation.
H, G4000H, G5000H, G6000H, G7
000H, a combination of TSK guardcolumn and the like. As the detector, a refractive index detector (IR detector) or a UV detector may be used. In measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated using a calibration curve created using monodispersed polystyrene standard particles. It is preferable to use about 10 polystyrenes for preparing a calibration curve.

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

Conventionally known inorganic pigments 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 mass relative to the polymer, preferably 3 to 1%.
5% by weight is selected. When used as a magnetic toner, the above-mentioned magnetite can be added. In this case, from the viewpoint of imparting predetermined magnetic properties, it is preferable to add 20 to 60% by mass to the toner.

Conventionally known organic pigments and dyes can be used. Specific examples of organic pigments and dyes are shown below.

The pigments for magenta or red include:
For example, C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I.
Pigment Red 6, C.I. I. Pigment Red 7,
C. I. Pigment Red 15, C.I. I. Pigment Red 16, C.I. 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. I. Pigment red 144, C.I. I.
Pigment Red 149, C.I. I. Pigment Red 1
66, C.I. I. Pigment Red 177, C.I. I. Pigment Red 178, C.I. I. Pigment Red 222
And the like.

Examples of orange or yellow pigments include C.I. I. Pigment Orange 31, C.I.
I. Pigment Orange 43, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I.
Pigment Yellow 14, C.I. I. Pigment Yellow 15, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 9
4, C.I. I. Pigment yellow 138, C.I. I. Pigment yellow 180, C.I. I. Pigment Yellow 1
85, C.I. I. Pigment yellow 155, C.I. I. Pigment Yellow 156 and the like.

The pigments for green or cyan include:
For example, C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 1
5: 3, C.I. I. Pigment Blue 16, C.I. I. Pigment Blue 60, C.I. I. Pigment Green 7 and the like.

As the dye, for example, C.I. I. Solvent Red 1, 49, 52, 58, 63
111, 122, C.I. I. Solvent Yellow 1
9, 44, 77, 79, 81, 82, 9
3, 98, 103, 104, 112, 16
2, C.I. I. Solvent Blue 25, 36, 60
70, 93, 95, etc., and mixtures thereof can also be used.

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

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

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

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

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

Examples of the alumina fine particles include commercially available products RFY-C and C-604 manufactured by Nippon Aerosil 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, calcium and the like of stearic acid, salts of zinc, manganese, iron, copper and magnesium of oleic acid, and zinc, copper, magnesium and calcium of palmitic acid. Metal salts of higher fatty acids such as salts of linoleic acid such as zinc and calcium, and salts of ricinoleic acid such as zinc and calcium.

The addition amount of these external additives is preferably 0.1 to 5% by mass based on the toner. As a method for adding the external additive, various known mixing devices such as a Turbula mixer, a Hensiel mixer, a Nauta 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 one-component developer or a toner containing magnetic particles of about 0.1 to 0.5 μm in a toner to form a magnetic one-component developer can be used. Can be used.

Further, it can be used as a two-component developer by mixing with a carrier. In this case, as the magnetic particles of the carrier, 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. Particularly, ferrite particles are preferable. The magnetic particles have a volume average particle size of 15 to 100 μm, more preferably 25 to 80 μm.
μm is preferred.

The volume average particle size of the carrier is typically measured by a laser diffraction type particle size distribution analyzer “HELOS” equipped with a wet disperser (SYMPATIC (SYMPIC)
(ATEC)).

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

[Image Forming Method] Next, an image forming method of the present invention and an apparatus used therefor will be described.

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

In FIG. 1, an exposure light is emitted from a semiconductor laser light source 1 based on information read by a document reading device (not shown). This is distributed by a polygon mirror 2 in the direction perpendicular to the plane of the paper of FIG. 1, and is radiated on the photoreceptor surface via an fθ lens 3 for correcting image distortion to form an electrostatic latent image. The photoreceptor is uniformly charged in advance by the charger 5 and starts rotating clockwise in synchronization with the timing of image exposure.

The electrostatic latent image on the surface of the photoreceptor is developed by the developing device 6, and the formed developed image is transferred to the recording material 8 conveyed at a proper timing by the operation of the transfer device 7. Further, the photoconductor 4 and the recording material 8 are separated by a separator (separation pole) 9, and the toner developed image is transferred and carried on the recording material 8, guided to the fixing device 100, and fixed.

The untransferred toner and the like remaining on the photosensitive member surface are
It is cleaned by a cleaning device 25 of a cleaning blade type, and residual charges are removed by a pre-charging exposure (PCL) 26, and is uniformly charged again by the charger 5 for the next image formation.

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

The cleaning blade 27 has a thickness of 1
A rubber-like elastic body of about 30 mm is used, and urethane rubber is most often used as a material. Since this is used while being pressed against the photoconductor, heat is easily transmitted, and it is desirable to keep the photoconductor away from the photoconductor when the image forming operation is not performed.

Next, a fixing device that can be used in the present invention will be described. FIG. 2 is a cross-sectional view showing an example of a fixing device used in the present invention. The fixing device shown in FIG. 2 includes a heating roller 10 and a pressure roller 20 which comes into contact with the heating roller 10.
And In FIG. 2, T is a toner image formed on a recording material (typically a transfer paper, also called an image support).

The heating roller 10 has a coating layer 12 made of a fluororesin formed on the surface of a metal core 11 and includes a heating member 13 made of a linear heater.

The inner diameter of the core metal 11 is set to 10 to 70 mm. The material constituting the metal core is not limited, but examples thereof include metals such as iron, aluminum, and copper, and alloys thereof.

The core metal 11 has a thickness of 0.1 to 2 mm.
It is determined in consideration of the balance between the demand for energy saving (thinning) and the strength (depending on the constituent materials). For example, 0.
In order to maintain the same strength as the iron core of 57 mm with the aluminum core, the wall thickness must be 0.8 mm.
mm.

As the fluororesin constituting the coating layer 12, PTFE (polytetrafluoroethylene) and PF
A (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) and the like.

The thickness of the coating layer 12 is 10 to 500 μm. Preferably it is 20 to 400 μm. 10μ thickness
If it is less than m, the durability of the fixing device cannot be ensured because the fluororesin has no durability. In addition, when the resin layer is thick, there is a problem that the paper powder is easily scratched, toner and the like adhere to the scratched portion, and image stains occur.

As the heating member 13, a halogen heater can be suitably used. In addition, not only one heating member but also a configuration in which a plurality of heating members are included and the heat distribution area can be changed according to the size (width) of the passing paper as shown in FIG. . The heating roller 15 shown in FIG. 3 is provided with a halogen heater 16A for heating a central region of the roller surface, and halogen heaters 16B and 16C for heating end regions of the roller surface. .

According to the heating roller 15 as shown in FIG. 3, when passing narrow paper, only the halogen heater 16A is energized, and when passing wide paper,
Further, the halogen heater 16B and the halogen heater 1
6C may be energized.

Returning to FIG. 2, the pressing roller 20
1 is provided with a coating layer 22 made of rubber on the surface thereof.
The rubber of the coating layer is not particularly limited, and urethane rubber, silicone rubber, and the like can be used, and more preferably, heat-resistant silicone rubber.
As the silicone rubber, for example, HTV (high
mpertature volcanizing), RT
V (room temperature volcan)
izing), LTV (low temperature)
e volcanizing silicone rubber or sponge.

The core metal 21 is not particularly limited, but examples of the material include metals such as aluminum, iron and copper or alloys thereof.

The thickness of the coating layer 22 is 1 to 30 mm, preferably 0.1 to 20 mm. If the thickness is less than 0.1 mm, the fixing nip cannot be increased, and the effect of soft fixing cannot be exhibited. The Asker C hardness of the silicone rubber or rubber constituting the coating layer 22 is less than 80 °, preferably less than 60 °, and silicone sponge rubber can be preferably used. The contact load (total load) between the heating roller 10 and the pressure roller 20 is usually 40 to 350 N, and preferably 50 to 350 N.
00N, more preferably 50-250N. The contact load is defined in consideration of the strength of the heating roller 10 (thickness of the metal core 11). For example, in the case of a heating roller having a core metal made of 0.3 mm iron, the contact load should be 250 N or less. Is preferred.

Further, from the viewpoint of offset resistance and fixability, the nip width is preferably 4 to 10 mm, and the surface pressure of the nip is preferably 0.6 to 1.5 × 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 10) is set to 150 to 210 ° C., and the fixing linear velocity is set to 80 to 640 mm.
/ Sec.

The fixing device used in the present invention may be provided with a cleaning mechanism for the fixing unit, if necessary. In this case, as a method of supplying the silicone oil to the upper roller of the fixing unit, a method of supplying and cleaning with a pad, a roller, a web, or the like impregnated with the silicone oil can be used. As the silicone oil, those having high heat resistance are used, and polydimethyl silicone, polyphenylmethyl silicone, polydiphenyl silicone and the like are used. Since those with low viscosity have a large outflow during use, the viscosity at 20 ° C. is 1 to 100 P
a · s are preferably used. In particular, the present invention is remarkably effective in a system in which silicone oil is not used or hardly required. In this case, the supply amount of the silicone oil is not particularly limited.
It is preferably about g / A4 or less. As a result, the amount of silicone oil adhering to paper or the like after fixing can be reduced, and there is no difficulty in writing an oil-based pen such as a ballpoint pen with the silicone oil adhering to the paper, and on the other hand, as an area where the problem of fixing offset does not occur. preferable. As a method of measuring the supply amount of the silicone oil, 100 sheets of A4 white paper are continuously passed through the fixing device heated to a predetermined temperature, and the supply amount of the silicone oil is obtained by a change in mass (Xmg) before and after the white paper is passed. Can be.

[0110]

EXAMPLES Hereinafter, the effects of the present invention will be described in more detail with reference to examples, but embodiments of the present invention are not limited thereto.

Example 1 << Preparation of Latex >> (Preparation of Latex 1) An anionic activator (sodium dodecylbenzenesulfonate) was previously placed in a 5000 ml separable flask equipped with a stirrer, a temperature sensor, a condenser, and a nitrogen introducing device. : SDS) A solution in which 7.08 g was dissolved in 2760 g of ion-exchanged water was added. While stirring at a stirring speed of 230 rpm under a nitrogen stream, the internal temperature was raised to 80
The temperature was raised to ° C. On the other hand, the exemplary compound (1
9) 72.0 g was added to a monomer composed of 115.1 g of styrene, 42.0 g of n-butyl acrylate, and 10.9 g of methacrylic acid, and heated and dissolved at 80 ° C. to prepare a monomer solution. Here, the above-mentioned heated solutions were mixed and dispersed by a mechanical disperser having a circulation path to produce emulsified particles having a uniform dispersed particle diameter. Then
A solution prepared by dissolving 0.84 g of a polymerization initiator (potassium persulfate: KPS) in 200 g of ion-exchanged water was added, and the mixture was heated at 80 ° C.
For 3 hours to produce latex particles. Subsequently, a solution obtained by dissolving 7.73 g of a polymerization initiator (KPS) in 240 ml of ion-exchanged water was added, and 1
Five minutes later, a mixture of 383.6 g of styrene, 140.0 g of n-butyl acrylate, 36.4 g of methacrylic acid, and 24.7 g of carbon tetrabromide as a chain transfer agent was added at 80 ° C. to 126
Dropped over minutes. After completion of the dropwise addition, the mixture was heated and stirred for 60 minutes, and then cooled to 40 ° C. to obtain latex particles. This latex particle is referred to as Latex 1.

(Preparation of Latex 2) Latex 1
In the preparation of, latex particles were obtained in the same manner except that 120.0 g of the exemplary compound (18) was used instead of the exemplary compound (19) as a release agent. This is designated as latex 2.

(Preparation of Latex 3)
, The amount of carbon tetrabromide, which is a chain transfer agent, is
Latex particles were obtained in the same manner except that the amount was changed from 4.7 g to 34.5 g. This is designated as Latex 3.

(Preparation of Latex 4) Latex 1
Latex particles were obtained in the same manner except that 15.0 g of t-dodecyl mercaptan was used as a chain transfer agent instead of carbon tetrabromide. This is designated as Latex 4.

<< Preparation of Toner >> (Preparation of Colored Particles 1Bk to 4Bk) 9.2 g of sodium n-dodecyl sulfate is stirred and dissolved in 160 ml of ion-exchanged water. To this solution, 20 g of Regal 330R (carbon black manufactured by Cabot Corporation) was gradually added under stirring, and then dispersed using CLEARMIX. The particle diameter of the dispersion was measured using an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd., and as a result, the mass average diameter was 112 nm.
Met. This dispersion is referred to as a colorant dispersion 1Bk.

Next, the prepared latex 1 was mixed with 12
50 g, 2000 ml of ion-exchanged water and colorant dispersion 1
Bk is stirred in a 5-liter four-necked flask equipped with a temperature sensor, a cooling tube, a nitrogen introducing device, and a stirring device. After adjusting to 30 ° C., a 5 mol / L aqueous sodium hydroxide solution was added to the solution to adjust the pH to 10.0. Then, an aqueous solution obtained by dissolving 52.6 g of magnesium chloride hexahydrate in 72 ml of ion-exchanged water was added under stirring to 30 ml.
C. for 10 minutes. Then, after leaving it to stand for 3 minutes, the temperature rise is started and the temperature is raised to 90 ° C. over 6 minutes (rate of temperature rise: 10 ° C./min). In this state, the particle size was measured with a Coulter counter TAII, and the volume average particle size was 6.
At 5 μm, an aqueous solution of 115 g of sodium chloride dissolved in 700 ml of ion-exchanged water was added to stop the particle growth. Further, the mixture is continuously heated and stirred at a liquid temperature of 90 ° C. ± 2 ° C. for 6 hours to cause salting out / fusion. Then 6
Cool to 30 ° C under the condition of ° C / min, add hydrochloric acid,
The pH was adjusted to 2.0 and the stirring was stopped. The generated colored particles were filtered, washed repeatedly with ion-exchanged water, and then dried with warm air at 40 ° C. to obtain colored particles. The colored particles obtained as described above were designated as colored particles 1Bk.

Next, colored particles 2Bk to 4Bk were prepared in the same manner as in the preparation of colored particles 1Bk except that latexes 2 to 4 were used instead of latex 1.

(Preparation of Colored Particles 1Y to 4Y) In the preparation of the colored particles 1Bk to 4Bk, the legal 330R
(Carbon black) instead of C.I. I. Colored particles 1Y to 4Y in the same manner except that Solvent Yellow 93 was used.
Was prepared.

(Preparation of colored particles 1M to 4M) In the preparation of the colored particles 1Bk to 4Bk, the legal 330R
(Carbon black) instead of C.I. I. Pigment Red 122 in the same manner except that Pigment Red 122 is used.
Was prepared.

(Preparation of Colored Particles 1C-4C) In the preparation of the colored particles 1Bk-4Bk, the legal 330R
(Carbon black) instead of C.I. I. Pigment Blue 15: 3 except that Pigment Blue 15: 3 was used.
C was prepared.

Table 1 summarizes the constitution of each of the colored particles prepared as described above.

[0122]

[Table 1]

(Preparation of Colored Particles 5Bk: Suspension Polymerization Method) In a four-necked flask equipped with a high-speed stirrer TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), 710 parts by mass of ion-exchanged water and 0.1 mol / L of trisodium phosphate aqueous solution (450 parts by mass), heated to 65 ° C., and stirred at a rotation speed of 12,000 rpm under a stirring condition of 1.0 mol / L calcium chloride aqueous solution 68.
A mass part was gradually added to prepare an aqueous dispersion medium of a dispersion containing colloidal tricalcium phosphate. Next, 14 parts by mass of Regal 330R (carbon black) was added to 165 parts by mass of the styrene monomer and 35 parts by mass of n-butyl acrylate, and 30 parts by mass of Exemplified Compound (19) as a release agent was added to a dispersion dispersed by a sand grinder. In addition, 80
Dissolved at ° C. Then, 2 parts by mass of carbon tetrabromide and 10 parts by mass of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator were added to the aqueous dispersion medium under stirring conditions at a rotation speed of 12,000 rpm. And a solution containing the monomer was dispersed in water. Then, using a reactor having a stirring blade as shown in FIG. 4, under a nitrogen stream, 65 ° C. and 200 rpm stirring conditions,
The polymerization reaction was performed for 0 hours. At the end of the polymerization reaction, hydrochloric acid was added to remove tricalcium phosphate as a dispersion stabilizer, followed by filtration, washing and drying to prepare colored particles 5Bk. In addition, by monitoring during polymerization and controlling the liquid temperature, the number of rotations of stirring, and the heating time, the variation coefficient of the shape and the shape coefficient are controlled, and further, by the submerged classification, the variation coefficient of the particle diameter and the particle size distribution are controlled. Arbitrarily adjusted.

(Preparation of Colored Particles 6Bk: Suspension Polymerization Method) Colored particles 6Bk were prepared in the same manner as in the preparation of the colored particles 5Bk except that t-dodecylmercaptan was used instead of carbon tetrabromide.

The average value (average circularity) of the shape factor, the standard deviation of the circularity, the circularity CV value, and the volume average particle diameter of the colored particles prepared as described above were measured by the following methods. Table 2 shows the obtained results.

The average circularity was determined by using FPIA-1000, using a sample analysis volume of 0.3 μl and a detected particle count of 150 μl.
The measurement was performed under the condition of 0 to 5000 pieces, and the average value was obtained.

[0127]

[Table 2]

The molecular weight of the peak of the high molecular weight component, the molecular weight of the peak of the low molecular weight component, and the molecular weight of the resin used in each of the prepared colored particle groups were measured by GPC (gel permeation chromatography) described above. Table 3 shows the results.

[0129]

[Table 3]

<< Preparation of Toner >> Next, the prepared colored particles 1Bk / 1Y / 1M / 1C to colored particles 4Bk / 4
Y / 4M / 4C, colored particles 5Bk and colored particles 6Bk
In each, hydrophobic silica (number average primary particle size = 12 nm,
1% by mass of hydrophobicity = 68) and 1% by mass of hydrophobic titanium oxide (number-average primary particle diameter = 20 nm, degree of hydrophobicity = 63), and mixed with a Henschel mixer to form toner 1Bk / 1Y / 1M. / 1C to toner 4Bk / 4Y / 4M
/ 10C, toner 5Bk and toner 6Bk.

The physical properties such as the shape and the particle size are as follows.
It was confirmed that there was no difference between each of the colored particles and each of the obtained toners.

<< Preparation of Developer >> For each of the toners prepared above, a silicone resin-coated volume average particle size of 6
0 μm ferrite carrier is mixed and the toner concentration is 6
% Developer was prepared. These developers correspond to developer 1Bk / 1Y / 1M / 1C to developer 4Bk / 4Y / 4M / 4C, developer 5Bk and developer 6Bk corresponding to the toner used.

<< Evaluation >> (Evaluation Apparatus) Using each of the developers prepared as described above, a digital color copier Konica 3015 in which the fixing device was changed to the following configuration was used to evaluate the actual printing.

As the fixing method, a pressure fixing type heat fixing device as shown in FIG. 2 was used. The specific configuration is as follows.

The surface was treated with PFA (tetrafluoroethylene-
Heat-roller 10 (upper roller) is a column-shaped aluminum alloy having a heater built in the center and having a thickness of 40 mm and an inner diameter of 40 mm, which is coated with a tube of perfluoroalkylvinyl ether copolymer (thickness: 120 μm) and having an inner diameter of 310 mm. ), And a pressure roller 20 (lower roller) having a 2.0 mm thick iron core having an inner diameter of 40 mm and a surface made of sponge-like silicone rubber (Asker C hardness = 48: thickness 2 mm). Have. The nip width is 5.
8 mm. Using this fixing device, the printing linear velocity was set to 250 mm / sec. Note that polydiphenyl silicone (20 ° C.) is used as a cleaning mechanism of the fixing device.
(The viscosity of which is 10 Pa · s) was used. The fixing temperature was controlled by the surface temperature of the upper roll, and was set to 175 ° C. The amount of silicone oil applied was 0.6 mg / A4.

(Evaluation of Fixing Property) The fixing property was evaluated by Y / M
A4 halftone image (image density is 1.0 with relative reflection density when paper density is "0") is printed with / C / Bk each printed in a single color, and fixing rate is It was measured. The fixing ratio is obtained by rubbing the surface of a fixed image with a 10N weight wound with a silk cloth, and calculating the percentage change in image density before and after the rubbing.

Fixing rate (%) = (image density after rubbing / image density before rubbing) × 100 The surface temperature of the heating roller was 175 ° C. as a center value.

(Evaluation of odor) The floor is 5 m × 5 m and the height is 2
m in a closed room at 180 ° C. as the set temperature of the heating roller, and a pixel ratio of 5
A full-color image of 0% and a monochrome image with a pixel ratio of 50% for each of the developers 5 and 6 were continuously printed on 1000 sheets, and the presence or absence of odor was evaluated by sensory evaluation. The rank of the odor was indicated by the number of persons who felt the odor by 10 panelists.

Table 4 shows the results obtained as described above.

[0140]

[Table 4]

As is clear from Table 4, it is found that the use of the developer comprising the toner according to the present invention has excellent fixability and suppresses the odor during image formation.

[0142]

According to the present invention, it is possible to provide a polymerized toner having a small particle diameter which is excellent in fixing property and suppresses generation of odor during heat fixing.

[Brief description of the 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 present invention.

FIG. 3 is an explanatory diagram showing an example of a heat distribution pattern of a heating roller constituting a fixing device used in the present invention.

FIG. 4 is a perspective view showing an example of a reaction apparatus having a stirring blade used in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor laser light source 2 Polygon mirror 3 fθ lens 4 Electrostatic latent image forming body (photoreceptor) 5 Charger 6 Developing device 7 Transfer device 8 Recording material 9 Separation pole 10 Heating roller 11 Core metal 12 Coating layer 13 Heating member 15 Heating Roller 16A Halogen heater 16B Halogen heater 16C Halogen heater 20 Pressure roll 21 Core metal 22 Coating layer 51 Heat exchange jacket 52 Stirrer tank 53 Rotating shaft 54 Lower stirring blade 55 Upper stirring blade 100 Fixing device

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideaki Morita 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation F-term (reference) 2H005 AA15 AB03 AB06 CA30 EA05 FB01

Claims (2)

[Claims] (1) salting out at least resin particles and a colorant;
In the fused toner, the volume average particle size is 3 to 8 μm.
m and the average value of the shape factor represented by the following equation 1 is 0.
930 to 0.980, wherein the resin particles are obtained by an emulsion polymerization method or a miniemulsion polymerization method using carbon tetrabromide as a chain transfer agent. Equation 1 Shape factor = Perimeter of circle obtained from equivalent circle diameter / Perimeter of particle projection 2. Salting out at least resin particles and a colorant.
In an image forming method for thermally fixing a toner image on an image support formed by a fused toner, the toner has a volume average particle diameter of 3 to 8 μm and an average shape factor represented by the following formula 1. An image forming method wherein the resin particles are obtained by an emulsion polymerization method or a mini-emulsion polymerization method using carbon tetrabromide as a chain transfer agent. . Equation 1 Shape factor = Perimeter of circle obtained from equivalent circle diameter / Perimeter of particle projection