JP2748183B2 - Polymerized color toner and image forming method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic image developing toner, and more particularly, to a polymerized color toner for developing an electrostatic image formed in electrophotography and an image forming method. .

[Background Art] As described in U.S. Pat. No. 2,297,691 and the like, a large number of methods are known for electrophotography. Generally, a photoconductor is used by various means using a photoconductive substance. An electric latent image is formed thereon, the latent image is developed using toner, a toner image is transferred to a transfer member such as paper as necessary, and then fixed by heating, pressure, solvent vapor, or the like to obtain a copy. Is a way to get As a method of developing using toner or a method of fixing a toner image, various methods have conventionally been proposed, and a method suitable for each image forming process has been adopted.

In recent years, high-speed copying and high image quality have been demanded for electrophotography, and the demand for color mixing between toners has been increasing with full-color printing. And low melt viscosity are required.

Generally, a toner is produced by melting and mixing colorants such as dyes and pigments, additives such as a charge control agent and a release agent in a thermoplastic resin, and uniformly dispersing the resulting mixture. A method for producing a toner having a desired particle size is known.

In these pulverized toners, it is necessary to use a thermoplastic resin having a low softening point in order to achieve low-temperature fixing, but as a result, a high-temperature offset phenomenon is likely to occur, and the addition of a release agent becomes difficult. Required. However,
Addition of an excessive release agent makes it impossible to perform sufficient melting and mixing necessary for the production of the toner, and even when the amount is adjusted, prevention of high-temperature offset and kneading while maintaining low-temperature fixability. It was practically difficult to satisfy all of the transparency when used as a color toner.

Polymerized toners have been proposed for these pulverized toners. For example, JP-A-56-87051 discloses a method for producing a polymerized toner in which polymerization is carried out in the presence of an offset inhibitor, and JP-A-59-218460 discloses a polymerized toner containing a hydrocarbon compound. JP-A-61-46955 discloses a polymerized color toner. Toners produced by these polymerization methods are generally obtained by subjecting a polymerizable monomer system to suspension polymerization in an aqueous medium, and do not pass through a pulverizing step, so that a large amount of a low softening point substance such as wax can be added. Further, since non-polar substances such as wax cannot exist on the particle surface and are encapsulated, they hardly affect the blocking property. The polymerized toner obtained in this manner has high-temperature offset resistance because wax is added thereto, but the low-temperature fixability and low-temperature offset resistance are still insufficient.

[Problems to be Solved by the Invention] An object of the present invention is to provide a polymerized color toner and an image forming method which solve the above-mentioned problems.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a polymerized color toner excellent in low-temperature fixability and low-temperature offset resistance and having a wide non-offset region, and an image forming method.

An object of the present invention is to provide a polymerized color toner and an image forming method which are excellent in color mixing property and color reproducibility and further excellent in transparency.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a polymerized color toner having high image density, excellent fine line reproducibility, and excellent highlight gradation, and an image forming method.

[Means and Actions for Solving the Problems] Specifically, the present invention provides at least a polymerizable monomer 100
Parts by weight, a polymerization color toner obtained by suspension polymerization of a polymerizable monomer system containing 5 to 30 parts by weight of a release agent and a colorant in an aqueous medium, wherein the release agent has a melting point of 75 ° C. or higher and 140 ° C. or higher. The present invention relates to a polymerized color toner, which is a wax having a melting temperature of 30 ° C. or less and a heat of fusion of less than 30 cal / g, and wherein the polymerized color toner is a toner selected from the group consisting of a polymerized yellow toner, a polymerized cyan toner and a polymerized magenta toner.

Further, the present invention provides a polymerized yellow toner obtained by suspension polymerizing a polymerizable monomer system containing at least 100 parts by weight of a polymerizable monomer, 5 to 30 parts by weight of a release agent and a colorant in an aqueous medium. Wherein the release agent is a wax having a melting point of from 75 ° C to 140 ° C and a wax having a heat of fusion of less than 30 cal / g, at least 100 parts by weight of a polymerizable monomer, and 5 to 30 polymerized parts of a release agent. And a polymerizable cyan toner obtained by suspension polymerization of a polymerizable monomer system containing a colorant in an aqueous medium, wherein the release agent has a melting point of 75 ° C. or more and 140 ° C. or less, and a heat of fusion of less than 30 cal / g. Polymerization obtained by suspension polymerization of a polymerized cyan toner as a wax and a polymerizable monomer system containing at least 100 parts by weight of a polymerizable monomer, 5 to 30 parts by weight of a release agent and a colorant in an aqueous medium. Magenta toner, the release agent having a melting point of 75 ° C. or more and 140 ° C. or less, and a heat of fusion of 30 cal / The present invention relates to an image forming method for forming a color image using a polymerized magenta toner which is a wax having a weight of less than g. Hereinafter, the present invention will be described in detail.

As a result of intensive studies, the present inventors have found that the wax added for imparting high-temperature offset resistance has an effect on low-temperature fixability and low-temperature offset resistance.

That is, a substance having a melting point of 75 ° C. to 140 ° C. functions as a release agent by melting at the time of fixing a toner, and particularly contributes to prevention of high-temperature offset. However, when such a wax is melted, energy as heat of fusion is required. The present inventors have found that the magnitude of the heat of fusion gives low-temperature fixability and low-temperature offset resistance. In other words, it was found that when the heat of fusion was 30 cal / g or more, the low-temperature fixability of the toner was significantly impaired.

On the other hand, when the melting point of the wax is lower than 75 ° C, the blocking resistance and the shape retention of the toner are insufficient, and
If it is larger, the effect of the releasability will be insufficient.

From the above, by using a wax having a melting point of 75 ° C. or more and 140 ° C. or less and a heat of fusion of less than 30 cal / g as a release agent, low-temperature fixing can be achieved while contributing to high-temperature offset resistance.

The melting point of the wax of the present invention was determined from the endothermic peak top by a differential scanning calorimeter (DSC).

The wax usable in the present invention has a melting point of at least 75 ° C.
140 ° C. or lower and any heat of fusion of less than 30 cal / g may be used, for example, grafted paraffin wax, α-
A random copolymer of olefin and ethylene can be used.

Such a release agent is preferably used in an amount of 5 to 30 parts by weight based on 100 parts by weight of the polymerizable monomer.

The polymerized color toner used in the present invention is obtained by the following method. That is, a monomer system in which a mold release agent, a colorant, a charge control agent, a polymerization initiator, and other additives are added to the polymerizable monomer and uniformly dissolved or dispersed by a homogenizer, an ultrasonic disperser, or the like, It is dispersed in an aqueous phase containing a dispersion stabilizer using a conventional stirrer or a homomixer / homogenizer. Preferably, the stirring speed and time are adjusted so that the monomer droplets have the desired toner particle size, generally a particle size of 30 μm or less, and thereafter the particle state is maintained by the action of the dispersion stabilizer, and the particle size is maintained. The stirring may be performed to such an extent that sedimentation is prevented. Polymerization temperature is over 40 ° C,
Generally, polymerization is carried out at a temperature of 50 to 90 ° C. After completion of the reaction, the generated toner particles are collected by washing and filtration, and dried. In the suspension polymerization method, usually, a monomer system 10
It is preferable to use 300 to 3000 parts by weight of water as a dispersion medium with respect to 0 parts by weight.

As the polymerizable monomer that can be used in the above-mentioned polymerized toner,
Styrene, o-methylstyrene, m-methylstyrene,
p-methylstyrene, p-methoxystyrene, styrene monomers such as p-ethylstyrene, methyl acrylate,
Ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-acrylate
Acrylates such as octyl, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-methacrylate Methacrylic esters such as butyl, isobutyl methacrylate, n-octyl methacrylate, dode, methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and others Monomers such as acrylonitrile, methacrylonitrile, acrylamide and the like can be mentioned.

These monomers can be used alone or as a mixture. Among the above-mentioned monomers, it is preferable to use styrene or a styrene derivative alone or in combination with another monomer from the viewpoint of the developing characteristics and durability of the toner.

As the coloring agent used in the present invention, known coloring agents can be used, for example, CI Direct Red 1, CI Direct Red 4, CI Acid Red 1, CI Basic Red 1, CI Modern Red 30, CI Direct Blue 1, CI Direct Blue 2, CI Acid Blue 9, CI Acid Blue 15, CI Basic Blue 3,
CI Basic Blue 5, CI Modern Blue 7, C.I.
I. Direct Green 6, CI Basic Green 4,
Dyes such as CI Basic Green 6, etc., graphite, cadmium yellow, mineral fast yellow, navel yellow, naphthol yellow S, Hanza yellow G, permanent yellow NCG, tartan rake, molybdenum orange, permanent orange GTR, benzidine orange G, cadmium lettuce , Permanent Red 4R, Watching Red Calcium Salt, Brilliant Carmine
3B, Fast Violet B, Methyl Violet Lake, Navy Blue, Cobalt Blue, Alkaline Blue Lake, Victoria Blue Lake, Quinacridone, Rhodamine B,
Pigments such as phthalocyanine blue, fast sky blue, pigment green B, malachite green lake, and final yellow green G are available. In the present invention, in order to obtain a toner using a polymerization method, it is necessary to pay attention to the polymerization inhibitory property and the aqueous phase migration property of the colorant, preferably, surface modification, for example, hydrophobicity by a substance without polymerization inhibition It is better to have a chemical treatment. In particular, attention is required when using dyes, since many of them have polymerization inhibitory properties. Preferred methods for surface treatment of the dye system include:
There is a method of polymerizing a polymerizable monomer in the presence of these dyes in advance, and the obtained colored polymer is added to a monomer system.

In the present invention, it is desirable to add a charge control agent to the toner material in order to control the chargeability of the toner. As these charge control agents, those having little polymerization inhibition and water phase transfer among known ones are used. For example, as positive charge control agents, nigrosine dyes, triphenylmethane dyes, quaternary ammonium salts, amines And polyamine-based compounds. Examples of the negative charge control agent include metal-containing salicylic acid-based compounds, metal-containing monoazo dye-based compounds, styrene-acrylic acid copolymers, and styrene-methacrylic acid copolymers.

The dispersion medium used in the present invention is any suitable stabilizer, for example, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose,
Ethyl cellulose, sodium salt of carboxymethyl cellulose, polyacrylic acid and salts thereof, starch, tricalcium phosphate, aluminum hydroxide, magnesium hydroxide, calcium metasilicate, barium sulfate, bentonite and the like can be used by dispersing them in an aqueous phase. This stabilizer is
It is preferable to use 0.2 to 20 parts by weight based on 100 parts by weight of the polymerizable monomer.

Also, for fine dispersion of these stabilizers, 0.001-0.1
Parts by weight of surfactant may be used. This is to promote the intended action of the dispersion stabilizer, and examples thereof include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate,
Examples include sodium laurate, potassium stearate, calcium oleate and the like.

In the monomer system, a polymer having a polar group as an additive
It is more preferable to carry out polymerization by adding a copolymer. Furthermore, in the present invention, a monomer system to which a polymer / copolymer having a polar group or a cyclized rubber is added is suspended in an aqueous phase in which a dispersant having the opposite polarity with the polar polymer is dispersed. Polymerization is preferred. That is, the cationic or anionic polymer / copolymer contained in the monomer system, or the cyclized rubber is polymerized with the reversely charged anionic or chaotic dispersant dispersed in the aqueous phase. The surface of the particles serving as the toner inside is electrostatically attracted, and the surface of the particles is covered with a dispersant to prevent and stabilize the coalescence of the particles, and the polar polymer added during polymerization collects on the surface layer of the particles serving as the toner. Therefore, it has a kind of shell-like form, and the obtained particles become pseudo capsules. Polar polymer with relatively high molecular weight
By using a copolymer or cyclized rubber, while imparting excellent properties of blocking property and development abrasion resistance to toner particles, by performing polymerization so as to contribute to improvement of fixing properties with a relatively low molecular weight inside. Thus, it is possible to obtain a toner that satisfies conflicting requirements of fixing property and blocking property. The polar polymer / copolymer and the reverse charge dispersant which can be used in the present invention are exemplified below.

(1) Examples of the chaotic polymer include polymers of nitrogen-containing monomers such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate, and copolymers with styrene / unsaturated carboxylic acid esters.

(2) Examples of the anionic polymer include nitrile monomers such as acrylonitrile, halogen-containing monomers such as vinyl chloride, unsaturated carboxylic acids such as acrylic acid and methacrylic acid,
Other examples include unsaturated dibasic acids / unsaturated dibasic acid anhydrides, polymers such as nitro monomers, and copolymers with styrene monomers. Further, a cyclized rubber may be used instead of these polar polymers.

(3) As the anionic dispersant, silica fine powder is preferably used, and in particular, colloidal silica having a BET specific surface area of 200 m ² / g or more is suitable.

(4) As the chaotic dispersant, aminoalkyl-modified colloidal silica (preferably having a BET specific surface area of 200 m ² / g
And the like, and finely divided hydrophilic positively chargeable silica, aluminum hydroxide and the like.

It is preferable to use 0.2 to 20 parts by weight of such a dispersant based on 100 parts by weight of the polymerizable monomer. More preferably, it is 0.3 to 15 parts by weight.

As the polymerization initiator, any suitable polymerization initiator, for example, 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'- Azobis (cyclohexane-1-carbonitrile), 2,
2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azo or diazo polymerization initiators such as azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2, Peroxide-based polymerization initiators such as 4-dichlorobenzoyl peroxide and lauroyl peroxide are exemplified. In general, the amount of these polymerization initiators to be added is 0.5 to 10% by weight of the polymerizable monomer.

The toner according to the present invention is preferably substantially spherical and has fine irregularities on the surface. As a method of obtaining such a toner, it is possible to fuse the fine particles to the surface of the spherical particles by any method, or to make the surface uneven at the stage of forming the spherical particles. Examples of a method for obtaining a toner having unevenness on the surface according to the present invention include the following methods.

1) Mechanochemical method: After the spherical toner particles and the resin fine particles are mixed, the resin fine particles are fused to the surface of the toner particles by the mechanochemical method.

2) Dry heat treatment method: After the spherical toner particles and the resin fine particles are mixed, mixing and heating are performed in a fluidized heating layer to fuse the resin fine particles to the surface of the toner particles.

3) Wet heat treatment method: After the spherical toner particles and the resin fine particles are mixed in a liquid or gas, heat treatment is performed in the liquid to fuse the resin fine particles to the surface of the toner particles.

4) Addition method of resin fine particles at the time of polymerization of toner particles: When toner particles are obtained by a polymerization method, resin fine particles are added to a monomer in advance, or resin fine particles are added in a polymerization process, and resin fine particles or a dispersion system are added. By controlling the physical properties, the resin fine particles are transferred to the toner surface to complete the polymerization.

5) Drying method after swelling: The toner particles are once immersed in a solvent to swell, and then dried in a heated air flow or under reduced pressure.
At this time, a spheroidizing process may be performed.

In the present invention, the resin fine particles used for imparting unevenness have a particle diameter of 1/200 to 1/10 of the spherical toner particles, preferably 1 to 1.
/ 100 to 1/10, and the material is, for example, a styrene-based resin, a styrene-acrylate copolymer, a styrene-methacrylate copolymer, styrene and another vinyl monomer (for example, , Acrylonitrile, butadiene, etc.), polyester resins and epoxy resins. Among these resins, vinyl resins are particularly preferably used because resin fine particles can be easily obtained by emulsion polymerization or the like.

The additive used for imparting various properties used in the present invention preferably has a particle diameter of 1/10 or less of the volume average diameter of the toner particles from the viewpoint of durability when added to the toner.
The particle size of the additive means an average particle size obtained by observing the surface of the toner particles with an electron microscope. As additives for the purpose of imparting these properties, for example, the following are used.

1) Fluidity imparting agent: metal oxide (silicon oxide, aluminum oxide, titanium oxide, etc.), carbon black, carbon fluoride, etc. Those subjected to a hydrophobic treatment are more preferable.

2) Abrasives: metal oxides (strontium titanate, cerium oxide, aluminum oxide, magnesium oxide, chromium oxide, etc.), nitrides (silicon nitride, etc.), carbides (silicon carbide, etc.) metal salts (calcium sulfate, barium sulfate, etc.) Calcium carbonate).

3) Lubricants: fluororesin powder (vinylidene fluoride, polytetrafluoroethylene, etc.), fatty acid metal salts (zinc stearate, calcium stearate, etc.).

4) Charge controllable particles: metal oxides (tin oxide, titanium oxide, zinc oxide, silicon oxide, aluminum oxide, etc.),
Such as carbon black.

These additives are used in an amount of 0.1 to 100 parts by weight of the toner particles.
10 parts by weight are used, preferably 0.1 to 5 parts by weight. These additives may be used alone or in combination of two or more.

The differential scanning calorimetry (DSC) used for measuring the melting point and the heat of the melting point of the release agent in the present invention was performed at a heating rate of 10 ° C./min using DSC-7 (manufactured by PerkinElmer).

 The measurement of the particle size distribution in the present invention will be described.

A Coulter Counter TA-II type (manufactured by Coulter) was used as a measuring device, and an interface (manufactured by Nikkaki) for outputting a number average distribution and a volume average distribution and a CX-1 personal computer (manufactured by Canon) were connected. A 1% aqueous NaCl solution is prepared using primary sodium chloride.

As a measurement method, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the aqueous electrolytic solution, and 0.5 to 50 mg of a measurement sample is further added.

The electrolytic solution in which the sample was suspended was subjected to a dispersion treatment for about 1 to 3 minutes by an ultrasonic disperser, and a 100 μm aperture was used as the aperture by the Coulter Counter TA-II.
The volume average distribution and the number average distribution are determined by measuring the particle size distribution of the particles having a size of 〜40 μm.

The volume average particle size is obtained from the obtained volume average distribution and number average distribution.

EXAMPLES Hereinafter, the present invention will be described in detail based on examples. still,
All parts are parts by weight.

Example 1 0.25 g of γ-aminopropyltrimethoxysilane was added to 1200 ml of ion-exchanged water, and hydrophilic colloidal silica (B
Add 5 g of ET specific surface area 200m ² / g), heat to 80 ° C, and use a TK homomixer M type (manufactured by Tokushu Kika Kogyo) at 10,000 rpm
For 15 minutes. Further, a 1 / 10N-HCl aqueous solution was added to adjust the pH in the system to 6.

The above formulation was heated to 80 ° C. in a container, and dissolved and dispersed using a TK homomixer to obtain a monomer mixture. 80 ° C
Was added and dissolved while adding 10 parts of dimethyl 2,2'-azobisisobutyrate to prepare a monomer composition. Into the two flasks containing the dispersion medium obtained above, the monomer composition was charged, and the mixture was stirred at 12,000 rpm for 60 minutes using a TK homomixer at 80 ° C. under a nitrogen atmosphere. The composition was granulated. Thereafter, polymerization was carried out at 80 ° C. for 20 hours while stirring with a paddle stirring blade. After the completion of the polymerization reaction, the reaction product was cooled, an aqueous NaOH solution was added, the dispersant was dissolved, and the mixture was filtered, washed with water, and dried to obtain spherical particles.

When the particle diameter of the obtained spherical particles was measured with a Coulter counter (aperture diameter 100 μm), the volume average diameter was determined.
It had a sharp particle size distribution at 6.5 μm.

Separately, put 150 parts of ion-exchanged water into a reaction vessel,
And 1 part of a monomer system of styrene / n-butyl methacrylate = 90/10 (parts / part) and 10 parts of a 10% by weight aqueous solution of ammonium persulfate are added under stirring.
Was added dropwise over 3 hours to obtain a seed latex. Then, 10 parts of methacrylic acid were added dropwise, and then polymerization was continued for 3 hours.
After completion of the polymerization, the system was cooled, washed with water, filtered, and dried to obtain spherical resin fine particles having a volume average diameter of 0.5 μm using Coulter N4.

To 50 parts of the spherical particles obtained above, 5 parts of the above resin fine particles were added,
The mixture was dispersed and mixed with a Henschel mixer. Separately, 0.25 g of γ-aminopropyltrimethoxysilane is added to 1200 ml of ion-exchanged water, hydrophilic colloidal silica (BET specific surface area: 200 m ² / g) is added, and a TK homomixer M type (manufactured by Tokushu Kika Kogyo) is added. After dispersion at 10,000 rpm for 15 minutes, a 1 / 10N-HCl aqueous solution was added to adjust the pH in the system to 6. Put this in an autoclave, add the mixed particles, and add
An immobilization treatment was performed at 30 ° C./1.2 Kg / cm ² for 30 minutes while heating and stirring. After the treatment, the dispersion was cooled, and the dispersant was further removed using an alkali, followed by washing, filtration, and drying to obtain spherical particles having irregularities. The volume average diameter of the obtained yellow toner particles measured by a Coulter counter (aperture diameter: 100 μm) was 7.5 μm.

A polymerized yellow toner was obtained by externally adding 0.6 parts of silica fine powder having a specific surface area of 200 m ² / g by the BET method and hydrophobized with hexamethyldisilazane to 100 parts of the spherical particles having irregularities. 90 parts of a styrene-acrylic resin-coated ferrite carrier was mixed with 10 parts of the toner to prepare a developer. Using the thus obtained developer, image formation was performed while changing the fixing temperature of Canon CLC-500, and the fixing property was evaluated.

As an evaluation method, the obtained fixed image was rubbed with silbon paper under a load of 50 g / cm ² , and the temperature at which the image density reduction rate before and after rubbing was 5% or less was defined as the fixing start temperature. Also,
The evaluation of the offset was performed by observing an image. Further OH
Evaluation of the transparency of the P-sheet, process speed 20mm / sec
The fixing was performed at a fixing roller surface temperature of 150 ° C., and the light transmission spectrum was measured with a spectrophotometer U-3400 (manufactured by Hitachi, Ltd.). The amount of toner on the unfixed image is 0.55 ± 0.05mg / c
It was m ^2.

As a result, the fixing start temperature was as low as 110 ° C., the non-offset region was 120 to 190 ° C., and low-temperature fixing was achieved.
The saturation of the fixed image is 74.5, and the transparency of the image on the OHP sheet when fixed at 150 ° C. is particularly good, and the spectral transmittance at 560 nm is 85.
%Met. The results are shown in Table 1. When a running test was performed on 30,000 sheets, the image density was 1.4 or higher, there was no fog, the resolution and gradation were excellent, no toner cleaning failure occurred, and toner scattering in the copying machine was not noticeable. . When the toner before and after the endurance was observed by an electron microscope, no deterioration of the silica particles was observed.

Example 2 0.1 M sodium triphosphate aqueous solution 4 in 650 ml of ion-exchanged water
80 parts were added, the mixture was heated to 80 ° C., and 72 parts of a 1M calcium chloride aqueous solution was added dropwise under high-speed stirring.

The above formulation was heated to 80 ° C. in a container, and dissolved and decomposed using a TK homomixer to obtain a monomer mixture. Another 80
While maintaining the temperature at 10 ° C, 10 parts of dimethyl 2,2'-azobisisobutyrate initiator was added and dissolved to prepare a monomer composition. In the two flasks containing the dispersion medium obtained above,
The monomer composition was charged, and the mixture was stirred at 9000 rpm for 60 minutes using a TK homomixer at 80 ° C. in a nitrogen atmosphere to granulate the monomer composition. Thereafter, polymerization was carried out at 80 ° C. for 20 hours while stirring with a paddle stirring blade. After completion of the polymerization reaction, the reaction product was cooled, an aqueous solution of HCl was added, the dispersant was dissolved, and the mixture was filtered, washed with water and dried to obtain spherical particles.

The volume average diameter of the obtained particles measured by a Coulter counter (aperture diameter: 100 μm) was 8.2 μm.

For 100 parts of the spherical particles, the non-surface area by the BET method is 20.
0 m ² / g, 0.6 parts of silica fine powder hydrophobized with hexamethyldisilazane was externally added to obtain a polymerized cyan toner. 90 parts of a styrene-acrylic resin-coated ferrite carrier was mixed with 10 parts of the toner to prepare a developer.

Using the developer obtained in this manner, manufactured by Canon Inc.
An image was formed by changing the fixing temperature of CLC-500, and the fixing property was evaluated.

When the same evaluation as in Example 1 was performed, the fixing start temperature was as low as 110 ° C., the non-offset region was from 120 to 190 ° C., and low-temperature fixing was achieved. The saturation of the fixed image is 47.2
The transparency of the image on the OHP sheet at the time of fixing at 150 ° C. was particularly good, and the spectral transmittance at 460 nm was 83%. The results are shown in Table 1.

Example 3 A dispersion medium was prepared in the same manner as in Example 2.

Granulation was performed in the same manner as in Example 2 with the above formulation. Further, polymerization was carried out at 80 ° C. for 20 hours while stirring with a paddle stirring blade. After the polymerization was completed, an aqueous HCl solution was further added to dissolve the dispersant, followed by filtration, washing and drying to obtain spherical particles.

The volume average diameter of the obtained particles measured by a Coulter counter (aperture diameter: 100 μm) was 7.9 μm.

The specific surface area of this spherical particle by the BET method is 200 m ² / g
0.6 parts of silica fine powder subjected to hydrophobic treatment with hexamethyldisilazane was externally added to obtain a polymerized magenta toner. 90 parts of a styrene-acrylic resin-coated ferrite carrier was mixed with 10 parts of the toner to prepare a developer. Using the developer thus obtained, CLC-500 manufactured by Canon Inc.
The image was formed by changing the fixing temperature of the toner, and the fixing property was evaluated.

The same evaluation as in Example 1 was performed. As a result, the fixing start temperature was as low as 110 ° C., and the non-offset region was 120 to 180 ° C., thus achieving low-temperature fixing. The chroma of the fixed image was 66.7, the transparency of the image on the OHP sheet at 150 ° C. was particularly good, and the spectral transmittance at 660 nm was 83%. Table 1 shows the results.
Shown in

Example 4 A two-component developer having the polymerized yellow toner and the carrier obtained in Examples 1 to 3, a two-component developer having the polymerized cyan toner and the carrier, and a two-component developer having the polymerized magenta toner and the carrier Made by Canon Inc. using developer
Using CLC-500, three full-color images were formed, and the same fixing test as in Example 1 was performed.

In particular, the saturation of the mixed color portion and the transparency of the OHP sheet were evaluated as a full-color image. As a result, the fixing start temperature was 110 ° C. for each of the red, green and blue image portions.
Thus, the non-offset region was 120 to 180 ° C., and low-temperature fixing was achieved even in a full-color image. The red, green, and blue image sections at 150 ° C have excellent color mixing properties of 55.5, 47.8, and 51.4, respectively. Furthermore, the reflective overhead projector uses an overhead projector to fix the OHP sheet at 150 ° C. The transparency of the image is particularly good, and the red part (660 nm), green part (560 nm) and blue part (460 n)
m), the spectral transmittance of each wavelength is 71% (660 nm), 7
5% (560 nm) and 67% (460 nm). The results are shown in Table 1.

Comparative Example 1 Spherical particles having a volume average diameter of 8.1 μm obtained by a Coulter counter (aperture diameter: 100 μm) were obtained in the same manner as in Example 1 except that the formulation in Example 1 was changed as follows.

A developer was prepared for the spherical particles having irregularities in the same manner as in Example 1, and the fixing property was evaluated.

As a result, the fixing start temperature was 120 ° C., and the non-offset region was 130 to 190 ° C. The saturation of the fixed image is 73.8,
Further, the transparency of the image on the OHP sheet at the time of fixing at 150 ° C. was good, and the spectral transmittance at 560 nm was 59%. The results of the running test of 30,000 sheets were as good as in Example 1.

Comparative Example 2 A cyan developer was obtained in the same manner as in Example 2 except that the grafted paraffin wax in Example 2 was changed to paraffin wax having a melting point of 80 ° C. and a heat of fusion of 38 cal / g. or,
A magenta developer was obtained in the same manner as in Example 3 except that the paraffin wax having a melting point of 70 ° C. was used instead of the high melting point paraffin wax (melting point 90 ° C.) in the toner formulation in Example 3. A three-color full-color image was evaluated in the same manner as in Example 4, using the yellow developer obtained in Comparative Example 1 and the cyan and magenta developers. as a result,
The fixing start temperature was 120 ° C. for each of the red, green and blue image portions, and the non-offset region was 130 to 180 ° C. The saturation of the red, green, and blue image areas at 150 ° C is 53.0, 45.7, and 49.5, respectively, and the color of the image on the OHP sheet when fixed at 150 ° C using a reflective overhead projector can be recognized. Slightly transparent but blackish, with spectral transmittances of 54% (660nm), 56% (560nm), and red (660nm), green (560nm) and blue (460nm) wavelengths, respectively. 52% (46
0 nm). The results are shown in Table 1.

Comparative Example 3 The same operation as in Example 2 was carried out except that the grafted paraffin wax as the release agent was changed to paraffin wax having a melting point of 50 ° C. and a heat of fusion of 37 cal / g, and the volume average diameter was 8.2 μm. Was obtained.

When the same evaluation as in Example 1 was performed, the fixing start temperature was 120 ° C. and the non-offset region was 130 ° C. to 180 ° C.

Further, the obtained image was rough due to a toner having a problem in blocking property and poor fluidity.

[Effects of the Invention] As described above, the toner of the present invention can provide a high-quality image with a wide non-offset region and an image having excellent transparency for OHP.

Continuation of front page (56) References JP-A-63-108359 (JP, A) JP-A-60-198292 (JP, A) JP-A-1-264892 (JP, A)

Claims (2)

(57) [Claims] 1. A polymerized color toner obtained by suspension polymerizing a polymerizable monomer system containing at least 100 parts by weight of a polymerizable monomer, 5 to 30 parts by weight of a release agent and a colorant in an aqueous medium. Yes, the release agent has a melting point of 75 ° C or higher and 140 ° C or lower, and a heat of fusion of 3
A polymerized color toner, which is a wax of less than 0 cal / g, wherein the polymerized color toner is a toner selected from the group consisting of a polymerized yellow toner, a polymerized cyan toner and a polymerized magenta toner. 2. A polymerized yellow toner obtained by suspension-polymerizing a polymerizable monomer system containing at least 100 parts by weight of a polymerizable monomer, 5 to 30 parts by weight of a release agent and a colorant in an aqueous medium. There is a polymerized yellow toner in which the release agent is a wax having a melting point of 75 ° C. or more and 140 ° C. or less and a heat of fusion of less than 30 cal / g, at least 100 parts by weight of a polymerizable monomer, 5 to 30 polymerized parts of a release agent, A polymerized cyan toner obtained by suspension polymerization of a polymerizable monomer system containing a colorant in an aqueous medium, wherein the release agent has a melting point of 75 ° C or higher and 140 ° C or lower, and a wax having a heat of fusion of less than 30 cal / g. And a polymerizable magenta obtained by suspension polymerizing a polymerizable monomer system containing at least 100 parts by weight of a polymerizable monomer, 5 to 30 parts by weight of a release agent and a colorant in an aqueous medium. Toner, and the release agent has a melting point of 75 ° C. or more and 140 ° C. or less, and a heat of fusion of less than 30 cal / g Image forming method and forming a color image using a polymerization magenta toner is a wax.