JP3154073B2 - Suspension polymerization toner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension polymerization toner used in a method for visualizing a latent image.

[0002]

2. Description of the Prior Art Electrophotography is disclosed in U.S. Pat. No. 2,297,6.
As described in, for example, JP-A-91, a number of methods are known. Generally, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means, and then the latent image is formed. The image is developed using toner, and if necessary, the toner image is transferred to a transfer member such as paper, and then fixed by heating, pressure, or solvent vapor to obtain a copy. Further, as a method of developing using toner or a method of fixing a toner image,
Conventionally, various methods have been proposed, and a method suitable for each image forming process has been adopted.

Conventionally, as a toner used for these purposes, a colorant comprising a dye or pigment is generally melt-mixed in a thermoplastic resin and uniformly dispersed, and then has a desired particle size by a fine pulverizer or a classifier. Has been producing toner.

[0004] Although this method can produce fairly good toners, it does have certain limitations, namely the choice of toner materials. For example, the resin colorant dispersion is brittle enough,
It must be able to be comminuted in an economically feasible production equipment. However, if the resin colorant dispersion is made brittle to satisfy these requirements, the particle size range of the particles formed when actually pulverized at high speed tends to be widened, and in particular, a relatively large proportion of fine particles Problem arises. Further, such a highly brittle material is liable to be further pulverized or powdered when used for development in a copying machine or the like. Further, in this method, it is difficult to completely and uniformly disperse solid fine particles such as a colorant in a resin,
Depending on the degree of the dispersion, fog may increase, the image density may decrease, or the color mixing / transparency may be poor. Therefore, care must be taken in the dispersion. Further, exposure of the coloring agent to the fracture surface may cause fluctuations in development characteristics.

On the other hand, in order to overcome the problems of the toner caused by these pulverization methods, Japanese Patent Publication Nos.
Nos. 10799 and 51-14895 propose a method for producing a toner by a suspension polymerization method. In the suspension polymerization method, a polymerizable monomer, a colorant, a polymerization initiator, and, if necessary, a crosslinking agent, a charge control agent, and other additives are uniformly dissolved or dispersed to form a monomer composition. A continuous phase containing the monomer composition containing a dispersion stabilizer,
For example, the toner particles are dispersed in an aqueous phase using a suitable stirrer, and simultaneously undergo a polymerization reaction to obtain toner particles having a desired particle size.

According to this method, since no pulverizing step is included, the toner does not need to be brittle, a soft material can be used, and energy can be saved because the classification step can be omitted. Reduction of time, improvement of process yield, etc.
Great cost reduction effect. Further, there is an advantage that a colorant is not exposed to the surface of the particles and uniform triboelectricity is obtained.

However, in recent years, there has been an increasing demand for higher definition and higher image quality of copiers and printers. In the technical field, attempts have been made to achieve higher image quality by reducing the particle size of toner. . When the particle size of the toner becomes smaller, the surface area per unit weight of the toner increases, and the amount of charge per unit weight of the toner tends to increase.
The image density is low, and the durability of many sheets tends to deteriorate. in addition,
Since the charge amount of the toner is large, the adhesive force between the toners and the like is strong, the fluidity is reduced, and problems are likely to occur in the stability of toner supply and the application of tribo to the supplied toner. In addition, the adhesive force to the photoreceptor is increased, and the transferability is reduced. As a result, image quality is deteriorated and cleaning failure is apt to occur.

[0008] Since the toner obtained by the suspension polymerization method generally has a substantially spherical shape, the adhesive force is strong, and the transferability and the like tend to be remarkable. As means for improving the transferability, it has been proposed in Japanese Patent Application Laid-Open No. 1-113764 or the like to use inorganic fine particles and organic resin particles simultaneously. According to this method, transferability is certainly improved, but in long-term durability, there arises a problem that released organic resin particles contaminate the carrier and the sleeve.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a suspension polymerization toner which has solved the above-mentioned problems.

It is another object of the present invention to provide a suspension polymerization method toner which can obtain a stable image without being affected by environmental changes in temperature and humidity.

It is another object of the present invention to provide a suspension polymerization method toner having clear image characteristics and excellent multi-sheet durability.

[0012]

SUMMARY OF THE INVENTION The present invention relates to a colored suspended resin particle having a practical sphericity of 0.90 to 1.00 of a Wardel containing at least a colorant, a low softening point substance and a charge control agent. , A suspension-polymerized toner having a mixture with an external additive, wherein a) the colored suspended resin particles comprise a polymerizable monomer, a colorant, a wax as a low softening point substance, and a charge control agent. At least the polymerizable monomer system contained therein is obtained by suspension polymerization in an aqueous medium, and b) the content of the low softening point substance in the colored suspended resin particles is:
5 to 30% by weight based on the suspension polymerization toner, and c) having the opposite polarity to the colored suspended resin particles as 100% by weight of the colored suspended resin particles as the external additive. ,
0.1 to 10 parts by weight of resin fine particles having an average particle diameter of 0.01 to 1 μm and a Wardell's practical sphericity of 0.90 to 1.00, and an average particle diameter smaller than that of the resin fine particles. A suspension polymerization method toner using 0.1 to 10 parts by weight of small inorganic fine particles.

The reason that the toner of the present invention can solve the above-mentioned problems and stabilize the charging property and improve the transfer property is not necessarily clear, but is presumed as follows.

In general, toner particles (namely, colored suspension resin particles) obtained by a suspension polymerization method are obtained by suspension polymerization of a polymerizable monomer system in an aqueous medium, so that the toner particles are present on and near the toner surface. Has a tendency that the polar group is localized. The resin fine particles are produced by various polymerization methods such as an emulsion polymerization method and a suspension polymerization method, but for the same reason,
Polar groups tend to be localized on and near the particle surface.

Therefore, the surface of the toner particles and the surface of the resin particles attract each other by the electrostatic interaction between the polar groups,
Since both particles are substantially spherical, both particles have a large adhesive force. For this reason, by suppressing the adverse effects that have conventionally been caused by the release of the resin fine particles from the toner, the chargeability of the toner can be stabilized, and the transferability can be improved.

Further, since the inorganic fine particles are present together with the resin fine particles, the fluidity of the toner is not impaired.

Both the suspension polymerization toner particles and the resin fine particles used in the present invention have a practical sphericity of 0.0.
90 to 1.00. Wardel's practical sphericity is 0.9
When the value is smaller than 0, the adhesion between the toner particles and the resin fine particles described above is weakened, and the resin fine particles are easily released.

As the low softening point substance contained in the toner,
Waxes generally used as mold release agents, such as hydrocarbon compounds, are preferred. Specific examples include paraffin, polyolefin-based waxes and modified products thereof, for example, oxides and grafted products, higher fatty acids, metal salts thereof, and amide waxes.

Particularly preferred are non-polar ones such as paraffin wax. When a non-polar wax is used, the wax localizes at the center of the toner particles and promotes localization of the polar group on the surface of the toner particles. The content is 5 to 30% by weight based on the toner.
When the content is less than 5% by weight, the effect of promoting the localization of the polar group on the surface of the toner particles decreases. When the amount is more than 30% by weight, although the effect of promoting localization is obtained, the blocking resistance of the toner is inferior.

These waxes are used in the ring and ball method (JIS K25).
Those having a softening point (sp) according to 31) of from 40 to 130 ° C, preferably from 50 to 100 ° C, are preferred. If the softening point is less than 40 ° C, the blocking resistance and shape retention of the toner are insufficient, and if it exceeds 130 ° C, the effect of the releasability is insufficient.

The monomers constituting the resin fine particles used in the present invention are not particularly limited, but need to be selected in consideration of the charge amount of the toner. Specific examples of the addition-polymerizable monomer that can be used in the present invention include the following vinyl monomers.

Styrene and its derivatives such as methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene,
Alkyl styrenes such as propyl styrene, butyl styrene, hexyl styrene, heptyl styrene and octyl styrene; halogenated styrenes such as fluoro styrene, chloro styrene, bromo styrene, dibromo styrene and iodo styrene; nitro styrene, acetyl styrene and methoxy styrene .

Further, addition polymerizable unsaturated carboxylic acids may be mentioned. For example, acrylic acid, methacrylic acid, α-
Addition-polymerizable unsaturated aliphatic monocarboxylic acids such as ethyl acrylic acid, crotonic acid, α-methyl crotonic acid, α-ethyl crotonic acid, isocrotonic acid, tiglic acid, ungeric acid, or maleic acid, fumaric acid, itaconic acid, Examples include addition-polymerizable unsaturated aliphatic dicarboxylic acids such as citraconic acid, mesaconic acid, glutaconic acid, and dihydromuconic acid.

Metal chlorination of these carboxylic acids can also be used, and this metal chlorination can be performed after the polymerization is completed.

Esters of the addition-polymerizable unsaturated carboxylic acid with alcohols such as alkyl alcohols, halogenated alkyl alcohols, alkoxyalkyl alcohols, aralkyl alcohols and alkenyl alcohols.

Specific examples of the alcohol include alkyl alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, amyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, dodecyl alcohol, tetradecyl alcohol and hexadecyl alcohol. Halogenated alkyl alcohols obtained by partially halogenating these alkyl alcohols; alkoxyalkyl alcohols such as methoxyethyl alcohol, ethoxyethyl alcohol, ethoxyethoxyethyl alcohol, methoxypropyl alcohol and ethoxypropyl alcohol; benzyl alcohol, phenylethyl alcohol;
Aralkyl alcohols such as phenylpropyl alcohol; alkenyl alcohols such as allyl alcohol and crotonyl alcohol.

Amides and nitriles derived from the above-mentioned addition-polymerizable unsaturated carboxylic acids; aliphatic monoolefins such as ethylene, propylene, butene and isobutylene; vinyl chloride, vinyl bromide, vinyl iodide, 1,2-dichloro Halogenated aliphatics such as ethylene, 1,2-dibromoethylene, 1,2-diiodoethylene, isopropenyl chloride, isopropenyl bromide, allyl chloride, allyl bromide, vinylidene chloride, vinyl fluoride, and vinylidene fluoride Olefin; 1,3-butadiene, 1,3-pentadiene, 2-
Methyl-1,3-butadiene, 2,3-dimethyl-1,
3-butadiene, 2,4-hexadiene, 3-methyl-
Examples thereof include conjugated diene-based aliphatic diolefins such as 2,4-hexadiene.

Further, vinyl acetates and vinyl ethers; and nitrogen-containing vinyl compounds such as vinyl carbazole, vinyl pyridine and vinyl pyrrolidone can be mentioned.

In the present invention, resin particles obtained by polymerizing one or more of these monomers can be used.

The method for producing the resin fine particles used in the present invention includes a suspension polymerization method, an emulsion polymerization method, a soap-free polymerization method,
A seed polymerization method can be used. Among them, a soap-free polymerization method which has no residual emulsifier, does not inhibit the chargeability of the toner, and has little environmental change in the specific electric resistance is preferable.

The average particle size of the resin fine particles is 0.01 to 1 μm.
m. When the particle size is less than 0.01 μm, the resin fine particles are strong in the toner, are easily attached to or embedded in the toner, and easily hinder the effect of the resin fine particles. On the other hand, when it is larger than 1 μm, the dispersion tends to be non-uniform, and the release of the resin fine particles is easily promoted. The addition amount of the resin fine particles is 0.1 to 10 parts by weight based on 100 parts by weight of the toner particles.

The inorganic fine particles used in the present invention are preferable because they have a smaller average particle diameter than the resin fine particles. If the average particle size is large, the fluidity of the toner deteriorates,
The effect of the resin fine particles is also impaired. The amount of the inorganic fine particles is 0.1 to 1 with respect to 100 parts by weight of the toner particles.
0 parts by weight. Specific examples of the inorganic fine particles include metal oxides such as silicon oxide, aluminum oxide, and titanium oxide. Each of them is preferably subjected to a hydrophobic treatment.

The polymerizable monomer constituting the polymerizable monomer system and the toner property imparting agent such as a colorant used in the present invention include the following.

Examples of the polymerizable monomer include styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, and p-ethylstyrene; methyl acrylate, acrylic Ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate and the like Acrylic esters; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, methacryl Phenyl, dimethylaminoethyl methacrylate, methacrylic acid esters such as ethyl methacrylate aminoethyl; other acrylonitrile, methacrylonitrile, and the like monomers acrylamide.

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 a mixture with another monomer, from the viewpoint of the developing characteristics and durability of the toner.

In the present invention, polymerization may be carried out by adding a resin having a polar group to the monomer system. The polar resins that can be used in the present invention are exemplified below. (1) Examples of the cationic polymer include a polymer of a nitrogen-containing monomer such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate, and a copolymer with styrene, an unsaturated carboxylic acid ester, and the like. (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. These polar resins are localized near the surface of the toner, thereby improving the blocking resistance of the toner.

As the colorant used in the present invention, known colorants can be used. For example, carbon black, iron black, C.I. I. Direct Red 1, C.I. I. Direct Red 4, C.I. I. Acid Red 1, C.I. I. Basic Red 1, C.I. I. Modant Red 30, C.I.
I. Direct Blue 1, C.I. I. Direct Blue 2, C.I. I. Acid Blue 9, C.I. I. Acid Blue 15, C.I. I. Basic Blue 3, C.I. I. Basic Blue 5, C.I. I. Modant Blue 7, C.I. I.
Direct Green 6, C.I. I. Basic Green 4, C.I. I. Dyes such as Basic Green 6; graphite, cadmium yellow, mineral fast yellow, navel yellow, naphthol yellow S, Hanza yellow G, permanent yellow NCG, tartrazine lake, molybdenum orange, permanent orange GT
R, benzidine orange G, cadmium red, permanent red 4R, watching red calcium salt,
Brilliant Carmine 3B, Fast Violet B,
Pigments such as methyl violet lake, navy blue, cobalt blue, alkali blue lake, Victoria blue lake, quinacridone, rhodamine lake, phthalocyanine blue, fast sky blue, pigment green B, malachite green lake, final yellow green G, and the like. In the present invention, in order to obtain a toner using a polymerization method, it is necessary to pay attention to the polymerization inhibitory and aqueous phase migration properties of the colorant, preferably, surface modification, for example,
It is better to perform a hydrophobic treatment with a substance that does not inhibit polymerization. In particular, attention must be paid to the use of dyes and carbon black since many of them have polymerization inhibitory properties. As a preferable method for surface-treating the dye system, there is a method in which a polymerizable monomer is polymerized in the presence of these dyes in advance, and the obtained colored polymer is added to the monomer system. Further, regarding carbon black, in addition to the same treatment as the above dye, a grafting treatment with a substance which reacts with the surface functional group of carbon black, for example, polyorganosiloxane or the like may be performed.

In the present invention, a magnetic substance may be added.
This is also preferably used after performing a surface treatment.

In the present invention, a charge control agent is added to the toner material for the purpose of controlling 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 compounds. Examples of the negative charge control agent include metal-containing salicylic acid compounds, metal-containing monoazo dye compounds, styrene-acrylic acid copolymers, and styrene-methacrylic acid copolymers.

As the polymerization initiator, any suitable polymerization initiator, for example, 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1'-azobis (cyclohexane-1-
Azo or diazo polymerization initiators such as carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile and azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide,
Peroxide-based polymerization initiators such as diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, and lauroyl peroxide are exemplified. These polymerization initiators are preferably added in an amount of 0.5 to 20% by weight of the polymerizable monomer.

In the present invention, a crosslinking agent may be added, and the preferable addition amount is 0.001 to 15% by weight.

The aqueous medium used in the present invention includes:
Eventually, an appropriate stabilizer is added. For example, as an inorganic compound, calcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, Examples include silica and alumina. As an organic compound, polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, polyacrylic acid and salts thereof, starch and the like can be used by dispersing them in an aqueous phase. This stabilizer is preferably used in an amount of 0.2 to 20 parts by weight based on 100 parts by weight of the polymerizable monomer.

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

When an inorganic compound is used among these dispersion stabilizers, a commercially available one may be used as it is, but in order to obtain finer particles, the inorganic compound may be formed in an aqueous medium.

For example, in the case of calcium phosphate, an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride may be mixed under high stirring.

The polymerized toner used in the present invention is obtained by the following method. That is, a mold release agent, a coloring agent, a charge control agent, a polymerization initiator and other additives are added to the polymerizable monomer, and a monomer system uniformly dissolved or dispersed by a homogenizer / ultrasonic disperser, It is dispersed in an aqueous medium containing a dispersion stabilizer by a conventional stirrer or a homomixer / homogenizer. Preferably, the granulation is performed by adjusting the stirring speed and time so that the monomer droplets have a desired toner particle size, generally a particle size of 30 μm or less. After that, due to the action of the dispersion stabilizer, the particle state is maintained,
In addition, stirring may be performed to such an extent that settling and floating of particles are prevented. After completion of the reaction, the aqueous medium is distilled off while adding the aqueous medium to the suspension to remove the dispersion stabilizer, and the generated toner particles are collected by washing / filtration and dried. In the suspension polymerization method, water 3 is usually added to 100 parts by weight of the monomer system.
It is preferable to use 00 to 3000 parts by weight as the dispersion medium.

In the above step, the polymerization is carried out at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. Further, the temperature may be raised in the latter half of the polymerization reaction.

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

As a measuring device, Coulter Counter T
A-II type (manufactured by Coulter), number average distribution,
Interface to output volume average distribution (made by Nikkaki)
And CX-1 personal computer (manufactured by Canon)
And the electrolyte is 1% Na using primary grade sodium chloride.
Prepare a Cl aqueous solution.

The measuring method is as follows.
In 50 ml, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant, 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 using an ultrasonic disperser, and the particle size distribution of particles of 2 to 40 μm was measured with the Coulter Counter TA-II using an aperture of 100 μm. Is measured to obtain a volume average distribution and a number average distribution. A weight average particle diameter is obtained from the obtained volume average distribution and number average distribution.

The average particle size of the resin fine particles means the average particle size obtained by observing the surface of the toner particles with an electron microscope.

The practical sphericity of Wardel is a value represented by the following equation.

[0054]

(Equation 1) The Wader's practical sphericity and the average particle size of the resin fine particles are determined from values obtained by measuring at least 50, preferably 100 or more particles.

Hereinafter, the present invention will be described in detail with reference to examples.

[0056]

Example 1 451 g of a 0.1 M Na ₃ PO ₄ aqueous solution was added to 709 g of ion-exchanged water and heated to 60 ° C., and then, using a TK homomixer (manufactured by Tokushu Kika Kogyo) at 12,000 rpm. And stirred. 68 g of 1.0 M CaCl ₂ aqueous solution
Was gradually added to obtain an aqueous medium containing Ca ₃ (PO ₄ ) ₂ .

Styrene 170 g 2-ethylhexyl acrylate 30 g C.I. I. Pigment Blue 15: 3 10 g Paraffin wax (sp. 70 ° C) 60 g Di-tert-butylsalicylic acid metal compound 5 g Styrene-methacrylic acid copolymer 10 g (Mw 50,000, acid value 20 mgKOH / g) The mixture was heated and uniformly dissolved and dispersed at 12,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo). Into this, 10 g of a polymerization initiator, 2,2′-azobis (2,4-dimethylvaleronitrile), was dissolved to prepare a polymerizable monomer system. The polymerizable monomer system was charged into the aqueous medium, and stirred at 10,000 rpm for 20 minutes with a TK homomixer at 60 ° C. in an N ₂ atmosphere to granulate the polymerizable monomer system. Thereafter, the mixture was reacted at 60 ° C. for 3 hours while stirring with a paddle stirring blade, and then the liquid temperature was set to 80 ° C., and the reaction was performed for 10 hours.

After the polymerization reaction was completed, the reaction mixture was cooled, hydrochloric acid was added to dissolve calcium phosphate, and then filtered, washed with water and dried to obtain colored suspended resin particles. The obtained particles had a weight average diameter of 8.3 μm and a sharp particle size distribution. Wardel's practical sphericity was 0.95.

With respect to 100 parts by weight of the obtained particles, BE
Resin fine particles produced by soap-free polymerization from 0.8 parts by weight of hydrophobic silica having a specific surface area of 200 m ² / g by T method and methyl methacrylate (average diameter 0.05 μm,
0.3 parts by weight of Wardell's practical sphericity (0.98) was externally added to obtain a suspension polymerization toner. 93 parts by weight of an acryl-coated ferrite carrier was mixed with 7 parts by weight of this toner to prepare a developer.

Using this developer and externally added toner, image formation evaluation was performed using a modified full-color copying machine CLC-500 manufactured by Canon.

The development contrast was set to 300 V and 2
When an image was formed at 3 ° C./65% RH, the obtained toner image had a high image density of 1.47 and was clear without fog. Further copying of 10,000 sheets was performed, and the image density fluctuation during that time was as small as 0.15, and fog and sharpness were equivalent to those at the initial stage. Under low-temperature and low-humidity conditions (20 ° C./10% RH), image development was performed with the development contrast set at 320 V. As a result, the image density was as high as 1.48, and a very stable and good toner image was obtained. .

When the development contrast was set to 270 V under high temperature and high humidity (30 ° C./80% RH) and an image was formed, the image density was 1.55, and a very stable and good toner image was obtained. Obtained.

Example 2 In Example 1, C.I. I. Pigment Blue 15: 3
To C. I. Pigment Yellow 17
The same operation was performed to obtain colored suspended resin particles. The obtained particles had a weight average diameter of 8.5 μm and a sharp particle size distribution. Wardel's practical sphericity was 0.97.

Thereafter, evaluation of image output was performed in the same manner as in Example 1.

The development contrast was set to 300 V, and 2
When an image was formed at 3 ° C./65% RH, the obtained toner image had a high image density of 1.49 and was clear without fog. Further copying of 10,000 sheets was performed, and the image density fluctuation during that time was as small as 0.12, and fog and sharpness were equivalent to those at the initial stage. Under low-temperature and low-humidity conditions (20 ° C./10% RH), image development was performed with the development contrast set at 320 V. As a result, the image density was as high as 1.47, and a very stable and good toner image was obtained. .

Image development was performed under a high-temperature and high-humidity condition (30 ° C./80% RH) with the development contrast set at 270 V. The image density was 1.60, and a very stable and good toner image was obtained. Obtained.

Example 3 In Example 1, resin fine particles as an external additive were converted into resin fine particles (average diameter 0.08 μm, practical sphericity of Wardel 0.97) produced by soap-free polymerization from styrene-methyl methacrylate. The image output evaluation was performed in the same manner as in Example 1 except for the change.

The developing contrast was set to 300 V, and 2
When an image was formed at 3 ° C./65% RH, the obtained toner image had a high image density of 1.50 and was clear without fog. Further copying of 10,000 sheets was made, and the image density fluctuation during that time was as small as 0.18, and fog and sharpness were equivalent to those at the initial stage. Under low-temperature and low-humidity conditions (20 ° C./10% RH), image development was performed with the development contrast set to 320 V. As a result, the image density was as high as 1.51, and a very stable and good toner image was obtained. .

An image was formed at a development contrast of 270 V under high temperature and high humidity (30 ° C./80% RH). The image density was 1.57, and a very stable and good toner image was obtained. Obtained.

Comparative Example 1 100 parts by weight of a polyester resin (Mw 17,000) obtained by condensing propoxylated bisphenol and fumaric acid I. Pigment Blue 15:34 parts by weight Di-t-butylsalicylate metal compound 2 parts by weight The above materials are sufficiently premixed with a Henschel mixer, melt-kneaded at least twice with a three-roll mill, cooled, and then used with a hammer mill. It was coarsely pulverized to about 1 to 2 mm, and then finely pulverized by an air jet pulverizer. The obtained finely pulverized material is classified to a particle size of 2 to 10 μm.
m were mainly collected to obtain colored resin particles. The weight average diameter was 8.2 μm. Wardel's practical sphericity is 0.
57.

Thereafter, the image formation was evaluated in the same manner as in Example 1.
After 00 sheets, the transferability was reduced, and the image density became light.

Comparative Example 2 An image formation evaluation was performed in the same manner as in Example 1 except that the average particle size of the resin fine particles was 1.2 μm. 10,0
After 00 sheets, the transferability was reduced, and the image density became light.

Comparative Example 3 In Example 1, the average particle size of the resin fine particles was 0.005 μm.
m was evaluated in the same manner as in Example 1 except that the m-type was used.
After 0000 sheets, the transferability was reduced and light image density was generated.

Comparative Example 4 In Example 1, the content of paraffin wax was 35
The image formation was evaluated in the same manner as in Example 1 except that the amount was changed to be% by weight. After 10,000 sheets of durability under high temperature and high humidity, transferability was deteriorated and image quality was deteriorated. .

COMPARATIVE EXAMPLE 5 An image formation evaluation was performed in the same manner as in Example 1 except that the paraffin wax content was changed to 3% by weight. After 10,000 sheets, cleaning failure occurred.

[0076]

According to the present invention, a suspension polymerization toner having stable and clear image characteristics and excellent durability can be obtained without being affected by environmental changes in temperature and humidity.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Makoto Kambayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Tatehiko Chiba 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (56) References JP-A-4-26859 (JP, A) JP-A-2-282268 (JP, A) JP-A-60-31147 (JP, A) JP-A-59-218460 (JP, A A) JP-A-54-45135 (JP, A) JP-B-52-32256 (JP, B1)

Claims (2)

(57) [Claims] At least a colorant, a low softening point substance and a charge
Practical sphericity of Wadel containing an electric control agent is 0.90
1. A suspension polymerization toner having a mixture of 1.00 colored suspension resin particles and an external additive, wherein: a) the colored suspension resin particles are a polymerizable monomer, a colorant,
Less waxes and charge control agents as softening point substances
Polymerizes a polymerizable monomer system containing both in an aqueous medium by suspension polymerization.
Are those obtained by Rukoto, b) the content of the low-softening substance of colored suspension resin particles,
5 to 30% by weight based on the suspension polymerization toner, and c) 100 parts by weight of the colored suspended resin particles as the external additive.
On the other hand, it has the opposite polarity to the colored suspended resin particles,
Resin fine particles having an average particle diameter of 0.01 to 1 μm and a practical sphericity of 0.95 to 1.00 of Wardel
0.1 to 10 parts by weight, and suspension polymerization toner, which comprises using 0.1 to 10 parts by weight of small inorganic particles average particle diameter than the resin particles. 2. The suspension polymerization method toner according to claim 1 , wherein the polymerizable monomer system further contains a resin having a polar group.