JPH0486746A - Electrophotographic color toner - Google Patents

Abstract

PURPOSE:To form an image having a sharp and good tone by using a polyester resin as the main component and specifying its glass transition point and softening point, and its average particle diameter, and the surface roughness of a fixed film when the toner is used for development. CONSTITUTION:The glass transition point and softening point of the main component resin are regulated to >= 40 deg.C and 80 - 150 deg.C, respectively, and the average toner particles have 2 - 12 mum, it is preferred to have such a sharpness that the toner particles being in the range of 0.5 - 2 D amount to >= 80 number % of the total particles, where D is an average particle diameter of the toner particles, and the surface roughness of the fixed film having a thickness of <=10 mum is regulated to 0.2 mum in terms of the center line roughness (Ra), thus permitting development performance of not only single color but also a color mixed with another color to be improved, and therefore the reproduction performance of an intermediate color to be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a color toner. More specifically, the present invention relates to a color toner that is used as a developer in electrophotographic copying machines, laser printers, etc., and is used for the purpose of expressing a color of any hue by superimposing three colors, yellow, cyan, and magenta.

(Prior art) In general, electrophotography involves photoconductive materials (often processed into a drum shape) made of inorganic materials such as selenium, amorphous silicon, and zinc oxide, or organic materials such as diazo compounds and dyes. (: photosensitive drum) is first charged in a negative manner,
Next, an electrostatic latent image is formed by irradiating image-modulated light, and developed by attaching powder to the electrostatic latent image using electrostatic force. After transferring the powder to the surface, it is fixed by applying pressure, heating, or other methods. Electrophotography is currently available in copying machines,
Widely used in laser printers, etc.

In electrophotography, a powder that develops an electrostatic latent image on a photosensitive drum and is ultimately transferred to a base material such as paper or film to form an image is called a toner. These toners usually have carrier particles (=carrier) such as iron powder or ferrite.
It is used as a so-called developer.

Conventionally, color toners used in electrophotographic developers are produced by adding coloring agents, charge control agents, fluidity modifiers, grinding aids, etc. to thermoplastic resins, kneading them, pulverizing them, and then classifying them. Particles produced by a pulverization method are used. In recent years, color toners with smaller particle sizes have been required to improve the quality of copied images.

When manufacturing fine particle size color toner using the pulverization method, coloring agents, charge control agents, fluidity modifiers, pulverization aids, etc. added to the thermoplastic resin, which is the main component, are added to the required particle size in advance. It must be crushed to a size smaller than the diameter, which inevitably increases manufacturing costs. These reasons make it difficult to industrially produce color toners with minute particle sizes by the pulverization method.

Against this background, in recent years, research has been conducted on color toners using emulsion polymerization, suspension polymerization, seed polymerization, and the like. In the emulsion polymerization method, polymerization is carried out in micelles of polymerizable monomers stabilized with a surfactant in water to obtain fine powder particles.

The suspension polymerization method is a method in which particles are obtained by polymerizing polymerizable monomers in a suspension system obtained by stirring water and polymerizable monomers. In the seed polymerization method, for example, particles obtained by other methods such as emulsion polymerization are used as seed particles, the seed particles are swollen with a solvent and a polymerizable monomer, and polymerization is performed within the swollen seed particles. This is a method of growing seed particles to a large size.

(Problems to be Solved by the Invention) Color toners are required to have various chemical or physical properties. However, in the conventional methods for producing color toners, no method has been proposed that satisfies all of these characteristics. Above all, color toner is “color”
Conventional methods do not provide color toners with a satisfactory level of color reproducibility, which is the most important characteristic.

This problem is especially true for over-the-top projectors (OHP).
An image is formed on a transparent film used in
It becomes noticeable when it is projected onto a screen using transmitted light.

In view of this situation, the present inventors have conducted extensive research to obtain a color toner that comprehensively satisfies many of these required characteristics, has excellent image sharpness, and can be industrially produced.As a result, the following invention has been developed. reached.

(Means for Solving the Problems) That is, the present invention provides that the main component resin has a glass transition point of 40°C.
above, the softening point is in the range of 80 to 150°C, the average particle size is 2 to 12 μm, and the toner is 10 μm.
The color toner for electrophotography is characterized in that the surface roughness after fixing with a film thickness of 0.2 μm or less in center line average roughness (Ra) is 0.2 μm or less.

The present invention relates to color toners in which the surface roughness after fixation significantly affects the color reproducibility especially when an image is formed on a transparent film used for OHP etc. and projected onto a screen using transmitted light. This was done as a result of the discovery.

The surface roughness after fixing is determined by the toner particle size distribution, charge amount distribution,
In the particle size distribution of toner, which is affected by the thermal properties of toner resin, when the average particle size is D, particles with a diameter in the range of 0.5D to 2D account for 80% of the total number on average.
It is preferable to have a sharpness that accounts for the above.

The average particle size must be in the range of 2 to 12 μm, preferably in the range of 3 to 8 μm, and more preferably in the range of 4 to 6 μm.
It is preferable to fall within the range of .

If the ratio of particles having a diameter of 0.5D or less, where D is the average particle diameter, is large, the fluidity of the toner may be impaired. Obstruction of fluidity affects the state of triboelectric charging, so that the distribution of toner charge amount becomes wider. The distribution of toner charge amount is a cause of "fogging" as well as variations in the density of a copied image. Furthermore, the toner tends to scatter during cleaning of the photosensitive drum, resulting in significant contamination of the inside of the apparatus. If the proportion of particles with a radius exceeding 2D increases when the average particle diameter is D, an unnecessary gap will be created between the photosensitive drum and paper during transfer from the photosensitive drum to paper, causing fine particles to move outward. It will generate a lot of "dust" that scatters. Furthermore, if there is a large proportion of particles with a diameter outside the range of 0.5D to 2D, where D is the average particle diameter, the thickness distribution of the toner layer transferred onto the paper will be thick ( This causes deterioration of the surface roughness after fixing.

Regarding the amount of charge on the toner, when mixed frictional charging is performed at a ratio where the effective surface area of the toner is smaller than the effective surface area of the carrier, the amount of charge per surface area of the toner is -20 to -200 [μC /TI], and when the average charge amount is Q, particles having a charge amount in the range of 0.5Q to 2Q preferably account for 70% or more of the total number on average. In addition, the average charge amount per toner is in the range of -3 to -15 [fC], and when the average charge amount is Q, the number average number of particles with a charge amount in the range of 0.5Q to 2Q is It is preferable that it occupies 70% or more of the total.

If the average charge amount is outside the preferred range, it will be difficult to match the charge amount of the photosensitive drum. Furthermore, when the average charge amount is Q, if the proportion of particles with a diameter outside the range of 0.5Q to 2Q is large, the thickness distribution of the toner layer transferred onto the paper becomes large, and the fixation This causes deterioration of the surface roughness later.

In the present invention, the main component resin of the color toner is not particularly limited, and styrene/acrylic resins, epoxy resins, polyester resins, etc. can be used. It is preferable to use a polyester resin from the viewpoints of adhesion to paper and film, sharp melting properties, etc.

The glass transition point of the polyester resin in the present invention is 40
℃ or higher. If the glass transition point is lower than this,
It has a tendency to aggregate during handling or storage, which may cause problems with storage stability.

The softening point of the polyester resin in the present invention is 80 to 15
It is in the range of 0°C. Color toners in which the softening temperature of the resin is kept lower than this tend to aggregate during handling or storage, and fluidity may deteriorate significantly, especially during long-term storage. If the softening point is higher than this, fixing performance will be impaired. In addition, since it is necessary to heat the fuser roll to a high temperature, the material of the fuser roll
In addition, the material of the base material to be copied is limited. Above all, if the softening point is outside this range, the surface roughness cannot be kept within the predetermined range.

For electrophotography in the present invention, the main component resin has a glass transition point of 40°C or higher, a softening point of 80 to 150°C, and an average particle size of 2 to 12 μm. In toner, the surface roughness after fixing with a film thickness of 10 μm or less is the center line average roughness (Ra)
As a method for obtaining a color toner having a size of 0°2 [μm or less, for example, an aqueous dispersion containing an ionic group-containing polyester resin as a main component and a vinyl monomer containing a counterion group of the resin in an equivalent ratio An example of a method for manufacturing by polymerizing 0.8 to 2.0 can be exemplified.

Here, the polyester resin mainly consists of a dicarboxylic acid resin and a glycol component. Dicarboxylic acid components include, for example, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, high P, 5-naphthalic acid, and aromatic oxycarboxylic acids such as p-oxybenzoic acid and p-(hydroxyethoxy)benzoic acid. acids, aliphatic dicarboxylic acids such as succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, unsaturated aliphatic acids such as fumaric acid, maleic acid, itaconic acid, hexahydrophthalic acid, tetrahydrophthalic acid, and , alicyclic dicarboxylic acids, etc.

If necessary, a small amount of tri- and tetracarboxylic acids such as trimellitic acid, trimesic acid, and pyromellitic acid may be included.

Glycol components include, for example, ethylene glycol, propylene glycol, 1,3-propanediol, 1,
4-butanediol, 1,5-bentanediol, 1.
6-hexanediol, neohentyl glycol, diethylene glycol, dipropylene glycol, 2,2.
4-) Dimethyl-1,3-bentanediol, 1,4-
Cyclohexane dimetatool, spiroglycol, 1°4-phenylene glycol, ethylene oxide adduct of 1,4-phenylene glycol, diols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide adduct of bisphenol A, and propylene oxide adduct,
Examples include ethylene oxide adducts and propylene oxide adducts of hydrogenated bisphenol A.

If necessary, a small amount of triol and tetraol such as trimethylolethane, trimethylolpropane, chrycerin, and pentanylthritol may be included.

Other examples of polyester polyols include lactone-based polyester polyols obtained by ring-opening polymerization of lactones such as ε-caprolactone.

The ionic groups contained in the polyester resin include anionic groups such as carboxyl groups, sulfonic acid groups, sulfuric acid groups, phosphoric acid groups, or salts thereof, or cationic groups such as primary to tertiary amine groups. and preferably a sulfonic acid metal base.

Examples of aromatic dicarboxylic acids containing sulfonic acid metal bases that can be copolymerized with polyester include sulfoterephthalic acid, 5-
Examples include metal salts of sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7dicarboxylic acid, and 5[4-sulfophenoxyfisophthalic acid. Metal salts include Li, Nas K1Mg1Ca)Cu
) Examples include salts such as Fe. Particularly preferred is 5-sodium sulfoisophthalic acid.

The amount of the aromatic dicarboxylic acid containing a sulfonic acid metal group is not limited as long as the aqueous dispersion can be obtained.
A range of approximately 20 to 500 equivalents/1,000,000 g is appropriate.

In the present invention, the polyester resins can be used alone or in combination of two or more if necessary.

Further, it can be mixed with amino resins, epoxy resin incyanate compounds, etc. in a molten state or a solution state, and furthermore, it can be partially reacted with these compounds. The obtained partial reaction product can also be used as a raw material for an aqueous dispersion.

The aqueous dispersion containing the ionic group-containing polyester resin of the present invention as a main component can be produced by any known method. That is, a polyester resin and a water-soluble organic compound are mixed in advance at 0 to 200°C and water is added to this, or a mixture of a polyester resin and a water-soluble compound is added to water and stirred at 40 to 120°C. Manufactured by Alternatively, by adding polyester resin to a mixed solution of water and a water-soluble organic compound,
It can also be produced by stirring and dispersing at 0°C.

In the present invention, the "vinyl monomer containing a counterionic group" refers to an ionic group opposite to the ionic group contained in the polyester resin (a counterion when the ionic group contained in the polyester resin is an anionic group). The cationic group means a vinyl monomer having a cationic group, and when the ionic group contained in the polyester resin is a cationic group, the counterionic group is an anionic group. Such ionic groups are often necessary to form stable aqueous dispersions of polyester resins.

The amount of counterionic groups in the polymer obtained by polymerizing vinyl polymerizable monomers is 0.8 to 2 in equivalent ratio to the amount of ionic groups in the polyester resin.
．． 01 is preferably in the range of 0.85 to 1.5. If the lower limit of this range is not reached, the growth of the fine particles will not occur.If the upper limit is exceeded, it will not only not contribute to the growth of the fine particles, but may also cause problems such as a decrease in the water resistance of the resin particles.

As the cationic group-containing vinyl monomer, for example, 2
-Aminoethyl (meth)acrylate, 2-N,N-dimethylamineethyl (meth)acrylate, 2-N,N
-diethylaminoethyl (meth)acrylate, 2-N
, N-dipropylamino (meth)acrylate, 2-N
, t-butylaminoethyl (meth)acrylate, 2-
(4-morpholino)-ethyl (meth)acrylate, 2
-vinylpyridine, 4-vinylpyridine, aminostyrene, etc.

In addition, examples of anionic group-containing vinyl heptamers include (meth)acrylic acid, itaconic acid, fluoroic acid, maleic acid,
Monomers containing carboxyl groups or their salts such as fumaric acid, styrenesulfonic acid, vinyltoluenesulfonic acid, vinylethylbenzenesulfonic acid, impropenylbenzenesulfonic acid, 2-chlorostyrenesulfonic acid, 2-methyl-4-chlorostyrene Sulfonic acid groups, such as sulfonic acid, vinyloxybenzenesulfonic acid, vinylsulfonic acid, (meth)allylsulfonic acid, sulfoethyl or sulfopropyl ester of (meth)acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, or Monomers containing the salts Phosphoric acids such as azidophosphoxyethyl (meth)acrylate, azidophosphoxypropyl (meth)acrylate 3-chloro-2-azidophosphoxypropyl methacrylate, bis(meth)acryloxyethyl phosphate, vinyl phosphate, etc. Examples include monomers containing groups or salts thereof.

In order to achieve the object of the present invention, a combination of an anionic group-containing polymer and a cationic group-containing vinyl monomer is more desirable. In addition, there is no problem in appropriately using known nonionic monomers.

There are no particular restrictions on the polymerization initiator used when polymerizing vinyl monomers, and examples include organic peroxides such as benzoyl peroxide and acetyl peroxide, 2,2°-azobisisobutyronitrile, 2,2'- Azo compounds such as azobis(2,4-dimethylvaleronitrile), persulfates, hydrogen peroxide,
Inorganic peroxides such as permanganates, water-soluble redox systems of the inorganic peroxides and reducing agents such as sulfites, bisulfites, metasulfites, hydrosulfites, thiosulfates, iron salts, oxalic acid, etc. Examples include initiators, but water-soluble redox initiators are preferred from safety and industrial viewpoints. The amount of polymerization initiator used is approximately 0.1 per vinyl monomer.
-3% by weight.

Although it is difficult to define the polymerization temperature unambiguously, it is possible to
In order to coalesce and grow into a spherical shape as the vinyl monomer polymerizes, it is desirable to adopt a temperature condition equal to or higher than the glass transition point (Tg) of the polyester resin; conditions below this temperature tend to produce irregularly shaped particles. By using a solvent or a plasticizer for the polyester resin, the apparent glass transition point (or minimum film-forming temperature) of the polyester resin can be lowered, and polymerization can be carried out at a temperature higher than this temperature. The types of such solvents and plasticizers are not limited (they are appropriately selected from known ones depending on the type of polyester resin, as long as they do not inhibit polymerization).

Other polymerization conditions are carried out according to conventional methods, but the method of charging the vinyl monomer in advance into an aqueous dispersion of polyester resin fine particles, and then dropping the polymerization initiator dropwise causes rapid coalescence and aggregation of the polyester resin fine particles. This is preferable because there is no problem.

The obtained aqueous dispersion of polyester resin particles is filtered,
It is extracted as a dry powder using conventional methods such as freeze drying and spray drying.

The method for coloring the color toner for electrophotography in the present invention is not particularly limited, and any known existing coloring agent such as a pigment, dye, or carbon black may be used. In particular, from the viewpoint of spectral transmission characteristics, it is preferable to use a dye. As the dye used for coloring, it is preferable to use a disperse dye, a basic dye, a cationic dye, a dispersed cationic dye, or the like. When obtaining a black color toner, there is no problem in using carbon black or the like. As carbon black, thermal black, acetylene black, channel black, furnace black, lamp black, etc. can be used. As the pigment, azo lake pigments, rhodamine pigments, quinacridone pigments, etc. can be used. These dyes, pigments, carbon black, etc. may be used alone or in combination as necessary.

In the electrophotographic color toner of the present invention, a charge control agent may be used to provide more stable charge. As a charge control agent that positively charges the color toner through friction with carrier particles (=carrier), for example, C
Titanates such as a 1B a, or carbonates,
Alkoxylated amines, polyamide resins such as nylon, pigments with positive zeta potential such as phthalocyanine blue, quinacridone red, azo metal complex green, etc., azine compounds, stearic acid-modified azine compounds, oleic acid-modified azine compounds , azine pigments such as nigrosine, and quaternary ammonium salt compounds. Examples of the charge control agent that imparts a negative charge to the color toner through friction with carrier particles include pigments with a negative zeta potential such as carbon black, halogenated phthalocyanine green, flavanstone yellow, and perylene red, and copper. , metal-containing azo compounds such as zinc, lead, and iron.

In the color toner of the present invention, a fluidity modifier such as fine alumina particles or fine silica particles may be added. The amount added is not particularly limited, but from the viewpoint of imparting appropriate fluidity, it is preferably 0.01 to 5% by weight, more preferably 0.1% by weight based on the color toner.
It is about 2% by weight.

In the case of a color toner knee-component developer that is used without being mixed with carrier particles (carrier), the color toner must have magnetism. In such a case, iron, cobalt, nickel, an alloy mainly composed of these, or an oxide such as ferrite may be included as necessary.

The method of treating the particles with the colorant, charge control agent, fluidity modifier, etc. described above is not particularly limited, and any known existing treatment method can be used. These may, for example, be dispersed in the particles, adsorbed onto the particles, coated on the particles, or implanted into the particle surfaces by, for example, a dry process such as the mechanofusilon method.

Further, the polyester resin used in the color toner of the present invention exhibits good fixing properties because it does not cause fusion or aggregation at room temperature, and its viscosity quickly decreases during fixing. The polyester resin used in the color toner of the present invention has excellent color development in dyeing and also has excellent stability against dyes, so it exhibits good photoresistance.

Since the color toner in the present invention has excellent transparency,
Not only does it produce a single color, but also has good color mixing properties when layered with other colors, so it has excellent reproducibility of intermediate colors.

Furthermore, when an image is formed on a transparent film used in an overhead projector or the like, the image projected onto a screen also exhibits good color tone.

EXAMPLES The present invention will be explained in more detail by way of Examples below, but the present invention is not limited thereto. In addition, the physical properties of the resin in Examples and Comparative Examples were measured by the following method.

・Melting point, glass transition point Temperature increase rate 1 by differential scanning calorimeter (manufactured by Shimabara Seisakusho)
The measurement was carried out at 0 for 7 minutes.

・Softening point Measured according to JIS K2351.

・Number average molecular weight (vapor pressure method) It was measured using a molecular weight measuring device (manufactured by Hitachi).

・Charge amount was measured using East Part Analyzer (manufactured by Micron for wires).

(Example) Example 1 In an autoclave equipped with a thermometer and a stirrer, 94 parts by weight of dimethyl terephthalate, 95 parts by weight of dimethyl isophthalate, 89 parts by weight of ethylene glycol,
80 parts by weight of neopentyl glycol and 0.1 part by weight of tetrabutoxy titanate were added.
The transesterification reaction was carried out by heating at 0°C for 120 minutes. Next, 6.7 parts by weight of 5-sodium sulfoisophthalic acid was added, and 22
Continue the reaction at 0 to 230°C for 60 minutes, and then at 250°C.
After raising the temperature to ℃, the pressure of the system is 1 to 10 mHg
As a result of continuing the reaction for 0 minutes, copolymerized polyester resin (A
1) was obtained.

The molecular weight of the obtained copolymerized polyester resin (A1) is 2
7001 sulfonic acid metal base is 118 equivalents/10000
It was 00g. The amount of sulfonic acid metal base was determined by measuring the sulfur concentration in the copolyester resin. Also,
As a result of NMR analysis, the composition of the copolymerized polyester resin (A1) is as follows: terephthalic acid 48.4M0L%, isophthalic acid 49.1M0L%, 5-sodium sulfoisophthalic acid 2.5M0L%, alcohol component: ethylene glycol. 61.2M0L%, neopentyl glycol 38.8M0L%.

After dissolving 34 parts by weight of the obtained copolymerized polyester resin (Al) and 10 parts by weight of butyl cellosolve at 110°C in a four-necked 1-liter separable flask equipped with a thermometer, condenser, and stirring blade, Aqueous dispersion of copolyester by adding 56 parts by weight of water at 80°C (B1)
I got it.

In a four-necked 1-liter separable flask equipped with a thermometer, condenser, and stirring blade, 834 parts by weight of copolyester aqueous dispersion (Bl), 35 parts by weight of deionized water,
Then, 5.8 parts by weight of dimethylaminoethyl methacrylate was added, and the temperature was raised to 70°C. Next, 100 parts by weight of an aqueous solution containing 0.2 parts by weight of ammonium persulfate was added dropwise over 30 minutes, and the reaction was continued at 70°C for an additional 20 minutes. As a result, the copolymer with a particle size on the submicron order that was present in the aqueous copolyester dispersion grew into particles with an average particle size of 4.8 μm and a particle size in the range of 0.5D to 2D, where 1 diameter is D. Polyester particles (C1) having a 92% occupancy (number) of particles having the following properties were obtained.

Water was added to the obtained polyester particles (C1) for 20
A polyester particle aqueous dispersion (Dl) of % by weight was obtained.

Sumitomo Chemical disperse dye Sumikalon Yellow 5E-5G
Disperse 10 parts by weight of (C, 1, Disperse Yellow 5) in 100 parts by weight of water to obtain a polyester particle dispersion (Di
) 500 parts by weight, heated to 50°C while stirring,
It was held for 60 minutes.

Thereafter, the mixture was cooled, filtered, washed, and dried in vacuum to obtain a yellow color toner (EIY).

Similarly, Sumitomo Chemical disperse dye Sumikalon Red 5E-3
Using BL1 Sumikalon Brilliant Blue 5-GL, magenta color toner (EIM) and cyan color toner (E I C
) was obtained.

One part by weight of each of the obtained colored color toners was mixed with 99 parts by weight of a carrier (spherical reduced iron powder with an average particle size of 80 μm) to obtain a two-component electrophotographic developer. The charge amount of color toner after mixing with carrier is (EIY) -105μ C/g (EIM)
−113 μ C/g (E I C) −1
It was 0.02 μC/g. Using these developers, 5,000 copies were continuously made on paper using an electrophotographic color copying machine using amorphous silicon as a photoreceptor.

The resulting copy was free from fog and fading, and showed a clear and good image. When this developer was used, the resolution was about 16 lines/l.

Using this developer, copies were similarly made on a transparent film for an overhead projector.

The thickness and surface roughness of the toner layer of the obtained copy were measured using a Surfcom surface roughness meter manufactured by Tokyo Seimitsu.

The thickness of the toner layer is 6.2 μm, and the surface roughness is Ra: 0.
It was 18 μm. The obtained copy had excellent spectral transmission characteristics, and the image projected onto the screen by the overhead projector showed a clear color tone without turbidity.

Further, no particular problems were observed in the humidity dependence of charging properties, flow properties, insulation properties, etc., as well as fixing properties, sharp melt properties, anti-offset properties, etc.

Example 2 94 parts by weight of dimethyl terephthalate, 95 parts by weight of dimethyl isophthalate, ethylene glycol
82 parts by weight, neopentyl glycol 98 parts by weight, and tetrabutoxy titanate 0.1 part by weight5
- using 1.2 parts by weight of sodium sulfoisophthalic acid,
Copolymerized polyester resin (
A2) was obtained. The obtained copolymerized polyester resin (A2
) had a molecular weight of 28,001 and the sulfonic acid metal base was 24 equivalents/1,000,000 g. In addition, as a result of NMR analysis, the composition of the copolymerized polyester resin (A2) was determined as follows: terephthalic acid 49.5M0L%, isophthalic acid 50.0M0L%, 5-sodium sulfoisophthalic acid 0.5M0L%, alcohol component as an acid component. Ethylene glycol was 52.5M0L%, and neopentyl glycol was 47.5M0L%.

Next, an aqueous dispersion (B2) of copolymerized polyester was obtained in the same manner as in Example 1, and polyester particles (C2) were further obtained in the same manner. The obtained polyester particles (C
The average particle size of 2) was 4.3 μIN o, and the occupancy rate (number) of particles having a particle size in the range of 5D to 2D was 88%.

The obtained polyester particles (C2) were made into a polyester particle aqueous dispersion (B2) in the same manner as in Example 1, and further dyed in the same manner as in Example 1 to form colored color toners (E2Y) (E2M). (E2C) was obtained.

5 parts by weight of each of the obtained colored toners were mixed with 95 parts by weight of a carrier (spherical reduced iron powder with an average particle size of 80 μm) to obtain a two-component electrophotographic developer. The charge amount of the color toner after mixing with the carrier was (EIY) −97 μC/g (ELM) −85 μC/g (EIC) −91 μC/g. Using these developers, 5,000 copies were continuously made on paper using an electrophotographic color copying machine using an amorphous silicon photoreceptor as in Example 1. The resulting copy was free from fog and fading, and showed a clear and good image.

The resolution was approximately 20 lines/mm.

Using this developer, copies were similarly made onto a transparent film for an Overherad projector.

The thickness and surface roughness of the toner layer of the obtained copy were measured using a Surfcom surface roughness meter manufactured by Tokyo Seimitsu.

The thickness of the toner layer is 4.8 μm, and the surface roughness is Ra: 0.
It was 11 μm. The obtained copy had excellent spectral transmission characteristics, and the image projected onto the screen by the Overherad projector showed a clear color tone without turbidity.

Further, no particular problems were observed in the humidity dependence of charging properties, flow properties, insulation properties, etc., as well as in fixing properties, sharp melt properties, anti-offset properties, etc.

Comparative Example 1 Copolymerized polyester resin (Al
) and 10 parts by weight of an azo yellow pigment, a rhodamine red pigment, and a phthalocyanine blue pigment, respectively, were premixed in a ball mill, melted and mixed in a roll mill, and ground and divided into spheres in a fine grinder. The average particle size is 6.7 μm.
Colored toners (D3Y) (D3M) (D3C) were obtained.

5 parts by weight of each of the obtained colored toners were mixed with 95 parts by weight of a carrier (spherical reduced iron powder with an average particle size of 8 μm) in the same manner as in the example to obtain a two-component electrophotographic developer. The charge amount of the toner after mixing with the carrier was (D3Y) -45Alc/g (D3M) -36 μc/g (D3C) -41 uC/g. Using these developers in the same manner as in Example 1, five consecutive images were printed on paper using an electrophotographic color copying machine using amorphous silicon as a photoreceptor.
000 copies were made.

The resulting copy had many scratches in the fine line areas, and a good image could not be obtained. The resolution was about 10 lines/circle.

Using this developer, copies were similarly made onto a transparent film for an Overherad projector. The thickness and surface roughness of the toner layer of the obtained copy were measured using a Surfcom surface roughness meter manufactured by Tokyo Seimitsu. The thickness of the toner layer is 8.5 μm1
The surface roughness was 0.24 μm in Ra. The resulting copy was projected onto a screen using an Overherad projector and observed. The projected image was extremely cloudy, especially in yellow, which should originally have a bright tone, and it was not possible to obtain an image with a clear tone.

(Effects of the Invention) As described above, the color toner according to the present invention has
It has excellent humidity dependence such as charging characteristics, flow characteristics, and insulation properties, as well as fixing properties, sharp melt properties, anti-offset properties, image sharpness, and color reproducibility during colorization. When viewed by projecting the image onto a screen using a Herad projector, it provides a clear and good image with bright color tone.

Claims (1)

[Claims] (1) A color toner for electrophotography in which the main component resin has a glass transition point of 40°C or higher, a softening point of 80 to 150°C, and an average particle size of 2 to 12 μm, and when the toner is used and fixed. , when the fixing film thickness is 10 μm or less, the surface roughness of the fixing film is 0.2 μm in center line average roughness (Ra).
A color toner for electrophotography characterized by the following: