JPH1073958A - Electrophotographic toner and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems of fog and reduction in image density related to spherical fine particle toner, and provide a toner suitable for electrophotograph of high quality by setting the atomic number ratio of fluorine to carbon on a toner particle surface to a specified value. SOLUTION: In an electrophotographic toner having a spherical toner particle containing at least a binder resin and a coloring agent, the atomic number ratio F/C of fluorine to carbon on the toner particle surface is 1.0%<=F/C<=40.0%. With less than 1.0%, flowability is not sufficiently increased, and with more than 40.0%, control of toner charging quantity is difficult. The ratio is more preferably 2.0%<=F/C<=25.0%, further more preferably 2.0%<=F/C<=20.0%. Further, the volume average particle size Dv of the photographic toner is 0.1μm<=Dv<=6.0μm. From the viewpoint of a higher quality of image, Dv is more preferably 0.1μm<=Dv<=5.0μm and, further more preferably, 0.5μm<=Dv<=4.5μm. Thus, the characteristic suitable for a higher quality of image of a small particle size spherical toner having a narrow particle size distribution can be exhibited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner used in electrophotography and a method for producing the same, and more particularly to a dry electrophotographic toner suitable for high-quality electrophotography and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, the size of toner particles has been reduced in order to faithfully reproduce a latent image. For example, the volume average particle size (D
v) When an image is formed using toner having a size of 10 μm or more, scattering of toner is observed at a boundary between an image portion and a non-image portion, and it is particularly difficult to accurately reproduce a minute dot or a line image as a latent image. By the way, conventional toners are resins, colorants,
After melt-kneading and sufficiently dispersing the charge control agent and other necessary additives, it was generally manufactured by coarse pulverization, fine pulverization, and then classification into a predetermined particle size range. When a small particle size toner is manufactured by this method, it is difficult to narrow the particle size distribution. It is possible to narrow the particle size distribution to some extent by repeatedly performing a classification operation on the small particle size toner obtained by this method, but the yield is extremely deteriorated. Small particle size toners with a wide particle size distribution do not have a great effect on faithful reproduction of latent images,
Fog on non-image parts is likely to occur.

At present, a polymerization method has been proposed as a method for efficiently producing a small particle size toner having a narrow particle size distribution. Specific examples of the polymerization method include an emulsion polymerization method, a suspension polymerization method, and a dispersion polymerization method.

The use of toners manufactured by these methods enables more accurate reproduction of a latent image. The scattering of the toner at the boundary between the image portion and the non-image portion is improved as the toner particle size becomes smaller and as the particle size distribution becomes narrower.

However, the volume average particle diameter (D
If v) is 5 μm or less, the image density is reduced and fogging tends to occur in the non-image area. This tendency becomes smaller as the toner particle size becomes smaller.
In addition, it becomes more remarkable as the particle size distribution becomes narrower. At present, no means has been found which can sufficiently solve this problem.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and provides a toner for electrophotography which can sufficiently exhibit characteristics suitable for high image quality of a small particle size spherical toner having a narrow particle size distribution, and its production. It provides a method.

[0007]

SUMMARY OF THE INVENTION The present invention relates to an electrophotographic toner having spherical toner particles containing at least a binder resin and a colorant, wherein an atomic ratio of fluorine to carbon (F / C) on the surface of the toner particles is obtained. ) Is 1.0% ≦ F / C
≦ 40.0%.

[0008] The present invention also provides a method for dissolving a polymerizable monomer in a solvent in which a polymer dispersion stabilizer is dissolved, and polymerizing the polymerizable monomer dissolved in the solvent. A method for producing a toner for producing spherical toner particles by depositing a polymer polymerized therein, wherein at least one of the polymerizable monomers is a fluorine-based monomer, And a method for producing the same.

In the present invention, the spherical toner particles mean particles having a shape factor (SF-1) of 100 ≦ SF-1 ≦ 140. From the viewpoint of high image quality, more preferably 10
0 ≦ SF−1 ≦ 120.

The shape factor SF-1 used in the present invention is:
10 using Hitachi FE-SEM (S-800)
This is a value obtained by sampling zero toner images at random, introducing the image information into an image analysis device (Luzex3) manufactured by Nicole via an interface, performing analysis, and calculating from the following equation.

[0011]

(Equation 1)

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have conducted a detailed study on the reduction in image density and the fogging problem in a non-image area, which are observed in a spherical toner in a region having a volume average particle diameter (Dv) of 5 μm or less. As a result, it has come to be considered that a decrease in toner fluidity is one of the major causes of this problem.

It is considered that as the particle size of the small particle size toner decreases, the packing between the toner particles tends to become very dense and the fluidity tends to deteriorate. When a toner having poor fluidity is used for electrophotography, it is difficult to uniformly charge all the toner particles during the charging process of the toner. The toner which is charged to be easily generated. The toner charged to the opposite polarity causes fog on the non-image portion. Further, such a non-uniformly charged toner particle group is liable to form aggregates of some toner particles. The toner containing lumps lowers the adhesion between the recording paper and the photoreceptor in the transfer step by a general electrostatic transfer method, so that the transfer efficiency of the toner deteriorates and a sufficient image density cannot be obtained. As described above, one of the causes of the decrease in image density and the fogging problem in the non-image area, which are observed in the spherical toner in the region having a volume average particle diameter (Dv) of 5 μm or less, is the decrease in the fluidity of the toner in this region. It is possible that the degree will be significant.

The present inventors have conducted studies to solve this problem, and as a result, have found that a toner having fluorine atoms on the surface of toner particles is effective. This is presumably because the surface energy of the toner particles was reduced and the frictional force between the toner particles was reduced. Further, such a toner having improved fluidity is preferable without causing clogging of the toner in a transport path in an image forming apparatus having a particularly long transport path. Specifically, when used in a color image forming apparatus having a rotary developing device using a screw, the effect is sufficiently exhibited.

The atomic ratio of fluorine to carbon (F / C) on the surface of the toner particles is preferably 1.0% ≦ F / C ≦ 40.0%. If it is less than 1.0%, the fluidity is not sufficiently increased, and if it is more than 40.0%, it becomes difficult to control the toner charge amount. More preferably, 2.0% ≦ F / C ≦ 25.0.
%, More preferably 2.0% ≦ F / C ≦ 20.0%.

In the present invention, the fluorine concentration on the surface of the toner particles was measured by X-ray photoelectron spectroscopy (XPS).
You may measure by other measuring methods.

The method for introducing fluorine atoms into the toner particle surface in the electrophotographic toner of the present invention is not particularly limited. After producing the polymer particles, a chemical or physical treatment may be performed to introduce fluorine atoms, or the polymer particles may be produced using a binder resin or monomer having a fluorine atom. A preferred method for introducing a fluorine atom is a method for producing polymer particles using a monomer having fluorine as described below.

The volume average particle diameter (Dv) of the electrophotographic toner of the present invention is 0.1 μm ≦ Dv ≦ 6.0 μm. 0.
If it is less than 1 μm, it becomes very difficult to handle the powder, and it is not suitable for an electrophotographic toner. If it is larger than 6.0 μm, the image quality deteriorates and a practically sufficient image cannot be obtained. 0.1 μm ≦ Dv ≦ 5.0 μm from the viewpoint of high image quality
Is more preferred. More preferably, 0.5 μm ≦ Dv ≦
It is 4.5 μm.

In the present invention, the particle size distribution is such that the ratio of the volume average particle size (Dv) to the number average particle size (Dn) is 1.0 ≦ Dv.
/Dn≦1.4. If Dv / Dn is greater than 1.4, toner scatters in the image, and fog or the like in a non-image portion is likely to occur. From the viewpoint of high image quality, more preferably 1.0 ≦ Dv / Dn ≦ 1.2, and still more preferably 1.0 ≦ Dv / Dn ≦ 1.1.

The particle size of the toner used in the present invention is measured by using a laser scan particle size distribution analyzer CIS-100 (manufactured by GALAI) in a state where 0.1 to 0.2 mg of a measurement sample is sufficiently dispersed in about 2 ml of a solvent. Is used to measure the particle size distribution and the like. The average particle diameter of the toner used in the present invention is an average particle diameter calculated on a volume basis. The particle size and the particle size distribution can be measured by a method other than laser scanning, but in the present invention, a method by laser scanning is more preferable.

The method for producing the electrophotographic toner of the present invention is not particularly limited. However, 1.0 ≦ D
Polymerization methods such as emulsion polymerization, suspension polymerization, and dispersion polymerization are required to efficiently produce spherical electrophotographic toners in the range of v / Dn ≦ 1.4 and 0.1 μm ≦ Dv ≦ 6.0 μm. preferable. More preferred are a suspension polymerization method and a dispersion polymerization method. More preferred is a dispersion polymerization method.

The method for producing the electrophotographic toner of the present invention based on the dispersion polymerization method will be described below.

The dispersion polymerization method is a method of polymerizing a monomer which dissolves in a solvent in which a dispersion stabilizer is dissolved but which does not dissolve a polymer to be formed.

In the dispersion polymerization method, a dispersion stabilizer, a solvent,
The particle size and particle size distribution of the produced particles can be controlled by the ratio of the amount of the monomer, the polymerization initiator, and other additives.

As a result of investigations by the present inventors, it has been found that the reproducibility of the particle size and particle size distribution of produced particles is improved when a fluorine-based monomer is used as a part of the monomer. This makes it possible to more stably produce an electrophotographic toner having the same characteristics. This is presumably because the fluoromonomer contributes to the stabilization of the particles in some way, but the detailed reason is not known.

The solvent used in the method for producing an electrophotographic toner of the present invention is determined mainly based on the solubility of the monomer and the polymer. Specifically, for example, water, methyl alcohol, ethyl alcohol, denatured ethyl alcohol, isopropyl alcohol, n-butyl alcohol,
Isobutyl alcohol, tert-butyl alcohol,
alcohols such as sec-butyl alcohol, tert-amyl alcohol, 3-pentanol, octyl alcohol, benzyl alcohol, and cyclohexanol; ether alcohols such as methyl cellosolve, cellosolve, isopropyl cellosolve, butyl cellosolve, and diethylene glycol monobutyl ether; acetone, methyl ethyl ketone And ketones such as methyl isobutyl ketone; esters such as ethyl acetate, butyl acetate, ethyl propionate and cellosolve acetate; hydrocarbons such as hexane, octane, petroleum ether, cyclohexane, benzene, toluene and xylene; carbon tetrachloride; Halogenated hydrocarbons such as trichloroethylene and tetrabromoethane; ethyl ether, dimethyl glycol, trioxane tetrahydrofuran Ethers; methylal, acetal such as diethyl acetal; formic acid, acetic acid, acids such as propionic acid; nitro propene, nitrobenzene,
Sulfur such as dimethylamine, monoethanolamine, pyridine, dimethylsulfoxide, dimethylformamide
It is selected from nitrogen-containing organic compounds and the like. Further, two or more of these solvents may be used in combination. The concentration of the monomer in the solvent is from 1% by weight of the solvent to 80% in the solvent.
%, Preferably from 10% to 65% by weight.

The fluorine-based monomer used in the method for producing an electrophotographic toner of the present invention is a fluorine-containing addition- or condensation-polymerized monomer. Preferably, 1
It is an addition polymerization type or condensation polymerization type monomer having three or more fluorine atoms in the molecule. More preferably, it is an addition polymerization type monomer having three or more fluorine atoms in one molecule. More preferably, it is a styrene-based, acrylic-based, or methacryl-based monomer having three or more fluorine atoms in one molecule. Most preferably, the following general formulas (I), (II) and (II)
Compounds represented by I) and (IV).

[0028]

Embedded image (Wherein, r is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R is an alkyl group having 1 to 16 carbon atoms having 3 or more fluoro groups, and r ′ is an alkyl group having 1 to 12 carbon atoms. And n is an integer of 1 to 6. Here, the alkyl group represents a substituted or unsubstituted one. Examples of the substituent include a halogen atom other than fluorine, an allyl group, a hydroxyl group, and a cycloalkyl group.) The monomer containing no fluorine to be copolymerized is an addition polymerization type or condensation polymerization type monomer. Preferably, it is an addition polymerization type monomer. Specifically, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-methylstyrene
-Chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn
-Hexylstyrene, pn-octylstyrene, p-
n-nonylstyrene, pn-decylstyrene, pn
Styrene such as dodecyl styrene and derivatives thereof; ethylenically unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; unsaturated polyenes such as butadiene and isoprene; vinyl chloride, vinylidene chloride, vinyl bromide, vinyl iodide and the like. Vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, methacrylic acid-2- Α-methylene fatty acid monocarboxylic esters such as ethylhexyl, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, acrylic acid Acrylic acids such as n-butyl acid, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, and phenyl acrylate Esters; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole And N-vinyl compounds such as N-vinylpyrrolidone; vinyl naphthalenes; acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide;

The electrophotographic toner of the present invention may or may not contain a binder resin containing no fluorine.
The binder resin containing no fluorine atom is an addition polymerization type or condensation polymerization type resin.

The concentration of the fluorine-based monomer used in the method for producing an electrophotographic toner of the present invention with respect to all the monomers is 0.1 mol% or more and 30 mol% or less. If it is less than 0.1 mol%, the fluidity of the toner does not sufficiently increase, and if it is more than 30 mol%, it becomes difficult to control the charge amount of the toner. More preferably, it is 0.5 mol% or more and 20 mol% or less, and still more preferably 1.0 mol% or more and 15 mol% or less.

The timing of adding the fluorine-based monomer is not particularly limited. By changing the timing at which the fluorine-based monomer is added, the particle size, particle size distribution, and characteristics of the electrophotographic toner can be controlled.

As the dispersion stabilizer used in the method for producing an electrophotographic toner of the present invention, there may be mentioned known polymer dispersion stabilizers.

Specific examples of the polymer dispersion stabilizer include polystyrene, poly-p-hydroxystyrene, polystyrene derivatives such as polystyrene sulfonic acid, polyacrylic acid, polymethacrylic acid, polyacrylic esters, polymethacrylic esters. , Polyvinyl alcohol, polyvinyl alkyl ethers, polyvinyl acetal, polyvinyl carboxylate, polyacrylamide, polymethacrylamide, polyacrylonitrile, polyvinylpyridine, polyvinylpyrrolidone, polyvinylimidazole, polyethyleneimine, poly-2-alkyl-2
-Oxazolines, polyvinylformamide, polyethylene, polypropylene, polyvinyl chloride, polydimethylsiloxane, polyoxyalkylenes, cellulose derivatives and the like. Two or more polymer dispersion stabilizers may be used simultaneously, or the polymer dispersion stabilizer may be a copolymer. The concentration of the dispersion stabilizer is 0.
1 to 50% by weight is preferred. More preferably 0.1 to 3
0% by weight.

As the polymerization initiator used in the method for producing an electrophotographic toner of the present invention, known polymerization initiators can be mentioned. Specifically, azo compounds such as 2,2-azobisisobutyronitrile and 2,2-azobis (2,4-dimethylvaleronitrile), peroxides such as benzoyl peroxide and methyl ethyl ketone peroxide,
Nucleophiles such as alkali metals, metal hydroxides, Grignard reagents, protonic acids, metal halides, and stable carbonium ions can be used. The concentration of the polymerization initiator is preferably from 0.1 to 20% by weight, more preferably from 0.1 to 10% by weight, based on the monomer.

As the chain transfer agent used in the method for producing an electrophotographic toner of the present invention, known chain transfer agents can be mentioned.

As the colorant used in the toner for electrophotography and the method for producing the toner for electrophotography of the present invention, known colorants can be mentioned. Specifically, carbon black, C.I. I Direct 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 15, C.I. I. Basic Blue 3,
C. 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; Cadmium Yellow, Mineral First Yellow, Navel Yellow, Naphthol Yellow S, Hansa Yellow G, Permanent Yellow NCG, Tartrazine Lake, Molybdenum Orange GTR, Benzidine Orange G, Cadmium Red 4R, Watching Red Calcium Salt , Brilliant Carmine 3B, Fast Violet B, Methyl Violet Lake, Cobalt Blue, Alkaline Blue Lake, Victoria Blue Lake,
Pigments such as quinacridone, rhodamine lake, phthalocyanine blue, fast sky blue, pigment green B, macalite green lake, final yellow green G; I. Solvent Yellow 6, C.I. I.
Solvent Yellow 9, C.I. I. Solvent Yellow 1
7, C.I. I. Solvent Yellow 31, C.I. I. Solvent Yellow 35, C.I. I. Solvent Yellow 10
0, C.I. I. Solvent Yellow 102, C.I. I. Solvent Yellow 103, C.I. I. Solvent Yellow 1
05, C.I. I. Solvent Orange 2, C.I. I. Solvent Orange 7, C.I. I. Solvent Orange 13,
C. I. Solvent Orange 14, C.I. I. Solvent Orange 66, C.I. I. Solvent Red 5, C.I. I.
Solvent Red 16, C.I. I. Solvent Red 1
7, C.I. I. Solvent Red 18, C.I. I. Solvent Red 19, C.I. I. Solvent Red 22, C.I.
I. Solvent Red 23, C.I. I. Solvent Red 143, C.I. I. Solvent Red 145, C.I. I. Solvent Red 146, C.I. I. Solvent Red 14
9, C.I. I. Solvent Red 150, C.I. I. Solvent Red 151, C.I. I. Solvent Red 157,
C. I. Solvent Red 158, C.I. I. Solvent Violet 31, C.I. I. Solvent violet 3
2, C.I. I. Solvent Violet 33, C.I. I. Solvent Violet 37, C.I. I. Solvent Blue 22, C.I. I. Solvent Blue 63, C.I. I. Solvent Blue 78, C.I. I. Solvent Blue 83, C.I.
I. Solvent Blue 84, C.I. I. Solvent Blue 85, C.I. I. Solvent Blue 86, C.I. I. Solvent Blue 104, C.I. I. Solvent blue 191,
C. I. Solvent Blue 194, C.I. I. Solvent Blue 195, C.I. I. Solvent Green 24, C.I.
I. Solvent Green 25, C.I. I. Solvent Brown 3, C.I. I. Dyes such as Solvent Brown 9; Examples of commercially available dyes include, for example, Mitsubishi Kasei's Diaresin Yellow-3G, Yellow-F, Yellow
low-H2G, Yellow-HG, Yellow-
HC, Yellow-HL, Orange-HS, Or
angel-G, Red-GG, Red-S, Red-H
S, Red-A, Red-K, Red-H5B, Vio
let-D, Blue-J, Blue-G, Blue-
N, Blue-K, Blue-P, Blue-H3G,
Blue-4G, Green-C, Brown-A,
Hodogaya Chemical's indigo dye SOT dye Yellow-1, Y
yellow-3, Yellow-4, Orange-
1, Orange-2, Orange-3, Scarl
et-1, Red-1, Red-2, Red-3, Br
own-2, Blue-1, Blue-2, Viole
t-1, Green-1, Green-2, Green
-3, Black-1, Black-4, Black-
6, Black-8, orient black, oil black, oil color Yellow-3G, Yellow
ow-GG-S, Yellow- # 105, Orange
e-PS, Orange-PR, Orange- # 20
1, Scarlet- # 308, Red-5B, Bro
wn-GR, Brown- # 416, Green-B
G, Green- # 502, Blue-BOS, Blue
e-IIN, Black-HBB, Black- # 80
3. Black-EB, Black-EX, Sumiplast Blue GP, Blue OR, Red OR of Sumitomo Chemical
FB, Red-3B, Yellow FL7G, Yellow GC
And Nippon Kayaku Kayaron polyester black EX-
SF300, Kayaset Red B, Blue A-2R, and the like. The concentration of the colorant is preferably 1 to 20% by weight based on the binder resin or monomer. In the method for producing an electrophotographic toner according to the present invention, the colorant may be polymerized in a state in which the colorant is dissolved or dispersed in a solution before polymerization, and the colorant may be contained in the fine particles, or a medium in which the colorant is dissolved or dispersed. Fine particles after polymerization may be dispersed therein and colored.

In the toner for electrophotography and the method for producing the toner for electrophotography of the present invention, a known charge control agent may be used for improving charge stability and developability. For example, as the positive charge control agent, an electron donating substance such as a nigrosine dye, a quaternary ammonium salt, and a resin containing an amino group, and as the negative charge control agent, an electron accepting substance such as a metal complex dye or a salicylic acid metal salt. be able to.

In the toner for electrophotography and the method for producing the toner for electrophotography according to the present invention, the improvement of fluidity, image quality,
Alternatively, a known surface modifier may be externally added for various purposes such as prevention of damage to the photoconductor. For example, vinylidene fluoride fine powder, resin fine powder such as polytetrafluoroethylene fine powder, zinc stearate, calcium stearate, fatty acid metal salts such as lead stearate, aluminum oxide, titanium oxide, metal oxides such as zinc oxide, Examples include finely divided silica such as wet-process silica and dry-process silica, and those obtained by subjecting such silica to a surface treatment with a silane coupling agent, a titanium coupling agent, silicone oil, or the like.

In the toner for electrophotography and the method for producing the toner for electrophotography of the present invention, a magnetic toner can be obtained by adding a magnetic substance to polymer particles.

[0040]

EXAMPLES The present invention will be described below with reference to examples. The present invention is not limited by the embodiments.

Example 1 Toner particles were produced as follows.

90 parts by weight of methanol 10 parts by weight of polyvinylpyrrolidone 1 part by weight of a fluorine-based monomer represented by the following structural formula (a) 1 part by weight of styrene 4 parts by weight of 2-ethylhexyl acrylate 4 parts by weight of azobisisobutyronitrile 2 parts by weight of copper Phthalocyanine pigment 1.5 parts by weight Chromium complex salt of di-tert-butylsalicylic acid 1 part by weight After sufficiently stirring and mixing and dissolving the above materials, a reaction vessel equipped with a thermometer, a stirrer, and a reflux condenser was purged with nitrogen. And heated to 65 ° C. under a nitrogen stream to react for 15 hours.

The obtained reaction product was filtered, and the filtrate was diluted with methanol, stirred sufficiently, and then filtered again. This operation was repeated several times. The obtained residue was sufficiently dried with a vacuum dryer to obtain toner particles.

Example 2 90 parts by weight of methanol 10 parts by weight of polyvinylpyrrolidone 2.5 parts by weight of a fluoromonomer represented by the structural formula (a) 25 parts by weight of styrene 5 parts by weight of 2-ethylhexyl acrylate 5 parts by weight of azobisisobutyronitrile 2 parts by weight Copper phthalocyanine pigment 1.5 parts by weight Chromium complex salt of di-tert-butylsalicylic acid 1 part by weight Toner particles were produced in the same manner as in Example 1 using the above materials.

Example 3 Toner particles were produced as follows.

90 parts by weight of methanol 10 parts by weight of polyvinyl phenol 25 parts by weight of styrene 5 parts by weight of n-butyl acrylate 2 parts by weight of azobisisobutyronitrile 1.5 parts by weight of copper phthalocyanine pigment 1.5 parts by weight of chromium complex salt of di-tert-butylsalicylic acid 1 Part by weight A thermometer, a stirrer, a reflux condenser, and a dropping funnel were attached to the reaction vessel, and the atmosphere was sufficiently replaced with nitrogen. The above-mentioned materials are sufficiently stirred, mixed and dissolved, and placed in a reaction vessel.
Was placed in a dropping funnel. The mixture was heated to 65 ° C. in a nitrogen stream and reacted for 15 hours. When the conversion of styrene reached 60%, the fluorine-based monomer was gradually added to the reaction system. Hereinafter, toner particles were produced in the same manner as in Example 1.

Example 4 90 parts by weight of methanol 10 parts by weight of polyvinylpyrrolidone 15 parts by weight of a fluoromonomer represented by the following structural formula (c) 15 parts by weight of styrene 3 parts by weight of n-butyl acrylate 3 parts by weight of azobisisobutyronitrile 2 Parts by weight Copper phthalocyanine pigment 1.5 parts by weight Chromium complex salt of di-tert-butylsalicylic acid 1 part by weight Using the above materials, toner particles were produced in the same manner as in Example 1.

Example 5 Toner particles were produced as follows.

90 parts by weight of methanol 10 parts by weight of polyvinylphenol 20 parts by weight of styrene 4 parts by weight of n-butyl acrylate 2 parts by weight of azobisisobutyronitrile 1.5 parts by weight of copper phthalocyanine pigment 1.5 parts by weight of chromium complex salt of di-tert-butylsalicylic acid 1 Part by weight A thermometer, a stirrer, a reflux condenser, and a dropping funnel were attached to the reaction vessel, and the atmosphere was sufficiently replaced with nitrogen. The above-mentioned materials are sufficiently stirred, mixed and dissolved, and placed in a reaction vessel.
Was placed in a dropping funnel. The mixture was heated to 65 ° C. in a nitrogen stream and reacted for 15 hours. When the conversion of styrene reached 80%, the fluorine-based monomer was gradually added to the reaction system. Hereinafter, toner particles were produced in the same manner as in Example 1.

Comparative Example 1 90 parts by weight of methanol 10 parts by weight of polyvinyl pyrrolidone 25 parts by weight of styrene 5 parts by weight of 2-ethylhexyl acrylate 2 parts by weight of azobisisobutyronitrile 1.5 parts by weight of copper phthalocyanine pigment 1.5 parts by weight of di-tert-butylsalicylic acid 1 part by weight of chromium complex salt Toner particles were produced in the same manner as in Example 1 using the above materials.

Comparative Example 2 90 parts by weight of methanol 10 parts by weight of polyvinylpyrrolidone 1 part by weight of a fluorine-based monomer represented by the structural formula (c) 30 parts by weight of styrene 6 parts by weight of 2-ethylhexyl acrylate 2 parts by weight of azobisisobutyronitrile Part Copper phthalocyanine pigment 1.5 parts by weight Chromium complex salt of di-tert-butylsalicylic acid 1 part by weight Using the above materials, toner particles were produced in the same manner as in Example 1.

Comparative Example 3 Toner particles were produced as follows.

90 parts by weight of methanol 10 parts by weight of polyvinylphenol 10 parts by weight of styrene 2 parts by weight of 2-ethylhexyl acrylate 2 parts by weight of azobisisobutyronitrile 1.5 parts by weight of copper phthalocyanine pigment 1.5 parts by weight of chromium complex salt of di-tert-butylsalicylic acid 1 Part by weight A thermometer, a stirrer, a reflux condenser, and a dropping funnel were attached to the reaction vessel, and the atmosphere was sufficiently replaced with nitrogen. The above-mentioned materials were sufficiently stirred, mixed and dissolved, and put into a reaction vessel. Then, 25 parts by weight of a fluorine-based monomer represented by the structural formula (c) was put into a dropping funnel. The mixture was heated to 65 ° C. in a nitrogen stream and reacted for 15 hours. When the conversion of styrene reached 60%, the fluorine-based monomer was gradually added to the reaction system. Hereinafter, toner particles were produced in the same manner as in Example 1.

Example 6 Red toner particles were produced by the following method.

90 parts by weight of methanol 5 parts by weight of polyvinylphenol 25 parts by weight of styrene 5 parts by weight of n-butyl acrylate 2 parts by weight of azobisisobutyronitrile 1.5 parts by weight of copper phthalocyanine pigment 1.5 parts by weight of chromium complex salt of di-tert-butylsalicylic acid 1 Parts by weight The polymerization reaction was carried out in the same manner as in Example 1. After the reaction, the colored particles were filtered, washed with methanol and dried. 25 parts by weight of the obtained particles were sodium perfluorovalerate 2
After reacting the respective parts, an ester reaction was carried out with the polyvinyl phenol adhering to the particle surface to introduce fluorine atoms, followed by filtration, washing and drying again to obtain toner particles.

Structural formula

[0057]

Embedded image

<Evaluation> Examples 1 to 6 and Comparative Examples 1 to 3
Was measured for the volume average particle size (Dv) and the particle size distribution (Dv / Dn) of the toner particles. Table 1 shows the results. Particle size measurement: 0.1-0.2mg of measurement sample in about 2ml of solvent
Was carried out using a laser scan particle size distribution analyzer CIS-100 (manufactured by GALAI) in a state of being sufficiently dispersed.

The fluorine concentrations on the toner particle surfaces of Examples 1 to 6 and Comparative Examples 1 to 3 were measured by X-ray photoelectron spectroscopy (XPS). Table 1 shows the results. The measuring apparatus used was ESCA750 manufactured by Shimadzu Corporation, the excitation X-ray was MgKα1,2 (1253.6 eV), and the photoelectron escape angle was 30 °.

The shape factor SF-1 of the toner particles of Examples 1 to 6 and Comparative Examples 1 to 3 was measured. Table 1 shows the results. The measurement was performed using the Hitachi FE-
This was performed using an SEM (S-800) and an image analyzer (Luzex3) manufactured by Nicole.

As a carrier, ferrite particles having an average particle diameter of 25 μm coated with a styrene-acrylic resin were used, and Examples 1 to 6 were used so that the toner concentration was 4.0% by weight.
The mixture was mixed with the toner particles of Comparative Examples 1 to 3 to obtain a two-component developer.

The two-component developer was subjected to image evaluation (image disturbance, fog, image density) using a modified full-color laser copying machine CLC-500 manufactured by Canon. At this time, in the full-color laser copying machine, the distance between the developer carrier (developing sleeve) of the developing device and the developer regulating member (magnetic blade) is 600 μm, and the distance between the developing sleeve and the electrostatic latent image carrier (photosensitive drum) is The distance was 450 μm, the peripheral speed ratio between the developing sleeve and the photosensitive drum was 1.4: 1, the magnetic field of the developing pole of the developing sleeve was 1 kOe, and the developing conditions were an alternating electric field of 1800 V _PP and a frequency of 2000 Hz. Set to.

The evaluation of the disturbance of the image was performed without passing through the fixing step.
A one-dot line image of 00 dpi was formed, and an unfixed image was obtained on recording paper. The disturbance of the edge of the line of this image was visually evaluated using an optical microscope. Those with very little disturbance were rated as ◎, and those with less disturbance were rated as △, Δ, ×. Table 1 shows the results.

The evaluation of fog was performed using a reflectometer TC-
The value obtained by subtracting the reflectance of the recording paper from the reflectance of the white background portion of the output image measured by 6DS (manufactured by Tokyo Denshoku) was used. Evaluation is less than 1.5%: ◎, 1.5% or more and 2.5%
Less than: ○, 2.5% or more and less than 4.0%: Δ, 4% or more:
X. Table 1 shows the results.

For evaluation of image density, a solid image was output, and the image density was measured with a reflection densitometer RD918 (manufactured by Macbeth). Evaluation: 1.4 or more: ◎, 1.35 or more
Less than 40: 、, 1.00 or more and less than 1.35: Δ, 1.0
Less than 0: x. Table 1 shows the results.

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[Table 1]

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The present invention solves the problems of fogging and image density reduction associated with spherical fine particle toner due to the presence of fluorine atoms on the toner particle surface, and provides an electrophotographic toner suitable for high quality electrophotography. An object of the present invention is to provide a manufacturing method thereof.

Claims (13)

[Claims] 1. An electrophotographic toner having spherical toner particles containing at least a binder resin and a colorant, wherein the atomic ratio of fluorine to carbon (F / C) on the surface of the toner particles is 1.0% ≦ F. /C≦40.0%, a toner for electrophotography. 2. The electrophotograph according to claim 1, wherein the atomic ratio of fluorine to carbon (F / C) on the particle surface is 2.0% ≦ F / C ≦ 25.0%. For toner. 3. The electrophotographic toner according to claim 1, wherein the spherical toner particles contain a homopolymer or a copolymer synthesized using a fluorine-based monomer. 4. The toner according to claim 1, wherein said toner has a volume average particle diameter (Dv) of 0.1.
4. The electrophotographic toner according to claim 1, wherein 1 .mu.m.ltoreq.Dv.ltoreq.6.0 .mu.m or less. 5. The toner according to claim 4, wherein the ratio between the volume average particle diameter (Dv) and the number average particle diameter (Dn) of the toner satisfies the following relationship: 1.0 ≦ Dv / Dn ≦ 1.4. The toner for electrophotography according to the above. 6. The toner according to claim 4, wherein the ratio between the volume average particle diameter (Dv) and the number average particle diameter (Dn) of the toner satisfies the following relationship: 1.0 ≦ Dv / Dn ≦ 1.2. The toner for electrophotography according to the above. 7. The method according to claim 1, wherein at least one of the fluorine monomers is
4. The electrophotographic toner according to claim 3, wherein the compound is a compound containing three or more fluorine atoms in one molecule. 8. At least one of the fluorine-based monomers is
The following general formula (I), (II), (III) or (I)
8. The compound represented by V)
The toner for electrophotography according to 1. Embedded image (Wherein, r is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R is an alkyl group having 1 to 16 carbon atoms having 3 or more fluoro groups, and r ′ is an alkyl group having 1 to 12 carbon atoms. And n is an integer of 1 to 6. Here, the alkyl group represents a substituted or unsubstituted one. Examples of the substituent include a halogen atom other than fluorine, an allyl group, a hydroxyl group, and a cycloalkyl group.) 9. The spherical toner particles have an SF-1 of 100.
The electrophotographic toner according to any one of claims 1 to 8, wherein the toner has a shape factor of from 1 to 140. 10. The spherical toner particles have an SF-1 of 10
The electrophotographic toner according to any one of claims 1 to 8, wherein the toner has a shape factor of 0 to 120. 11. A polymerizable monomer is dissolved in a solvent in which a polymer dispersion stabilizer is dissolved, and the polymerizable monomer dissolved in the solvent is polymerized. A method for producing spherical toner particles by precipitating the polymer, wherein at least one of the polymerizable monomers is a fluorine-based monomer. 12. The method according to claim 11, wherein at least one of the fluorine-based monomers is a compound containing three or more fluorine atoms in one molecule. 13. The method according to claim 1, wherein at least one of the fluorine-based monomers has the following general formula (I), (II), (III) or (IV): (Wherein, r is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R is an alkyl group having 1 to 16 carbon atoms having 3 or more fluoro groups, and r ′ is an alkyl group having 1 to 12 carbon atoms. And n is an integer of 1 to 6. Here, the alkyl group represents a substituted or unsubstituted one. Examples of the substituent include a halogen atom other than fluorine, an allyl group, a hydroxyl group, and a cycloalkyl group.) The method for producing an electrophotographic toner according to claim 12, wherein the compound is represented by the following formula: