JPH05119524A - Electrophotographic toner - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic toner excellent in picture image density and resolution, and various physical properties without fogging or splashing by specifying ranges of dimensional coeffts. of toner particles for an electrostatic charge image developing toner containing a polymer, coloring agent, and if necessary, charge controlling agent. CONSTITUTION:In the electrostatic charge image developing toner containing a polymer, coloring agent, and if necessary, charge controlling agent, the dimensional coefft. S of toner particles is 100.5-160.0. More preferably, the toner particles consist of primary particles of a polymer containing acid polarity groups or basic polarity groups and associated particles of secondary particles containing agent particles and if necessary, charge controlling agent. More preferably, the average particle size rm of particles and the min. radious rn of particle surface satisfy the relation of formula I, and the toner contains substantially no particle satisfying rm=rn and have 2.5-12mum volume average particle size.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to electrophotography, electrostatic recording,
The present invention relates to a toner for developing an electrostatic charge image in electrostatic printing or the like.

[0002]

2. Description of the Related Art Conventionally widely used toner
Is a dry-blended styrene / acrylate copolymer powder obtained by suspension polymerization with a charge control agent such as carbon black and / or a magnetic material, and then melt-kneaded with an extruder or the like. , Then crushed and classified. (See JP-A-51-23354).

[0003]

However, the toner obtained by the above-mentioned melt-kneading and pulverization method has a limitation in controlling the particle size of the toner, and thus the toner having a small particle size can be produced with a high yield. In addition to being difficult to use, it has a low resolution when used as a developer due to non-uniform dispersion and the charge amount distribution becomes broad, and avoids the disadvantages of fogging and scattering. There was a problem that I could not do it.

Further, the shape of each individual toner particle is extremely indefinite, and the surface condition is not constant due to the outcrop of the crushed surface and the exposure of pigments such as colorants. Therefore, not only the charge amount distribution of the toner, especially the charge amount distribution relating to the charge amount of individual particles becomes non-uniform, but the above-mentioned problems on the image occur, and the life of the developer is shortened. There was also.

[0005]

SUMMARY OF THE INVENTION The inventor
The resolution is high, and there is no fog or scattering.
As a result of various studies on a toner excellent in life characteristics and stability of charge amount, it was found that a toner having the above drawbacks improved can be obtained.

The toner for developing an electrostatic charge image of the present invention is a toner for developing an electrostatic charge image which comprises a polymer, a colorant and an optional charge control agent, and the shape factor S value of toner particles is
The present invention provides a toner for developing an electrostatic charge image, which is 100.5 to 160.0.

Preferred are associated particles of primary particles and colorant particles of a polymer having an acidic polar group or a basic polar group, and secondary particles containing an optional charge control agent, and having an S value of 100.5. To 160.0, and a toner for developing an electrostatic charge image, more preferably containing primary particles and colorant particles of a polymer having an acidic polar group or a basic polar group, and an optional charge control agent. And associated particles of secondary particles,

The average particle diameter = rm and the minimum value of the radius of curvature of each particle surface = rn are 1.01 ≦ V ≦ 320 V = rm / rn 2.5 ≦ rm ≦ 16 0.05 ≦ rn <rm A toner for developing an electrostatic charge image, characterized in that substantially no particles of rm = rn are present and the volume average particle diameter is 2.5 to 12 μm.

The S value referred to here is the shape factor obtained by dividing the square of the peripheral length of the toner particles by the area. That is,
The planar image of toner particles is processed by an image processor or the like, the perimeter (PM) and the area (A) are calculated, and this is obtained by the following formula.

S value = [(PM) ² ÷ (4Aπ)] × 100

The S value representing the shape factor expresses the feeling of planar unevenness of the particles, and the closer the shape of the toner particles is to a circle (sphere), the closer it is to 100, and the surroundings. The more complicated the shape of, the larger the value.

Further, what is meant by the V value here is that the above-mentioned S value expresses a feeling of planar unevenness, while a three-dimensional expression is applied. The toner for developing an electrostatic image of the present invention is preferably an association of primary particles of a polymer having an acidic polar group or a basic polar group and colorant particles, and secondary particles containing an optional charge control agent. Since it is a particle, the unevenness feeling is the primary particle of the polymer,
This is due to the colorant particles, the charge control agent and their secondary particles.

Therefore, by processing the plane image of each toner with an image processor or the like, the unevenness of the particle surface can be digitized as a radius of curvature, and the relationship with the average particle diameter of each toner can be derived. Thus, it is possible to express the feeling of unevenness of the entire toner particles (particularly as associated particles).

The present invention provides a toner for developing an electrostatic charge image, which solves the above-mentioned problems by defining the S value, preferably the V value, of these shape factors. That is,
When the S value is smaller than 100.5, the toner particles tend to be spherical, and when used as a developer, the charge amount becomes low, and the image density becomes insufficient or fog occurs. It will occur and the life will be shortened.

Further, when it is larger than 160, the surface condition becomes mussels and becomes a non-uniform surface stochastically, so that when used as a developer, the charge amount is not stable and the charge amount distribution becomes uneven. In addition to the above-mentioned problems on the image, the life characteristics are shortened due to the occurrence of differentiation and the like.

The S value in the present invention is set to 100.5 to 160, preferably 102.0 to 155, more preferably 105.0 to 155, further preferably 107.0 to 140, and particularly preferably 110.0 to 135 to solve the above problems. And also V
The value is set to 1.01 to 320, preferably 1.05 to 300, and more preferably 2.00 to 250 to solve the above problems.

The toner for developing an electrostatic charge image of the present invention will be described below. The toner of the present invention is composed of 40 to 98 parts by weight of the polymer and 60 to 2 parts by weight of the colorant as in the conventionally known toner. The above-mentioned polymer is generally produced by an emulsion polymerization method, a suspension polymerization method, a precipitation polymerization method, an interfacial polymerization method, a mechanical pulverization method of synthetic resin pieces, an association method utilizing ζ potential, a coacervation method or the like. , An emulsion polymerization method, a suspension polymerization method, an association method utilizing ζ potential, etc. are preferred, and the toner constituted by them may be produced by any method as long as the characteristics of the toner of the present invention are not impaired. Although it does not matter, an emulsion polymerization method, a suspension polymerization method, an association method utilizing a ζ potential or the like is preferable.

As a preferred embodiment of the present invention, for example, preferred examples of the polymer include styrene alkyl (meth) acrylates and a comonomer having an acidic polar group or a basic polar group (hereinafter referred to as "polar group"). Having a comonomer
That is) a copolymer.

Preferred specific examples of such a copolymer are:
(A) Styrenes 90 to 20 based on the sum of (a) and (b)
% By weight, preferably 88 to 30% by weight and (b) 80 to 10% by weight of alkyl (meth) acrylates based on the sum of (b) and (b), preferably 70 to 12% by weight and , (C)
A copolymer containing 0.05 to 30 parts by weight, preferably 1 to 20 parts by weight, of a comonomer having a polar group when the total of (a) and (b) is 100 parts by weight.

Further, the above-mentioned copolymers are (a), (b), and
In addition to the monomer (c), a comonomer which can be copolymerized to an extent not impairing the performance of the toner of the present invention may be optionally contained. Further, the toner constituted by them may be produced by any method as long as it does not impair the aspect of the present invention, but the surface modification method of the kneading pulverization toner and the emulsion weight Preferred are a method, a suspension polymerization method, and an association method utilizing ζ potential. In addition, as a particularly preferable example, the toner which is an associated particle of primary particles and a colorant particle of a polymer having a basic polar group and secondary particles containing an optional charge control agent is produced. But

The polymer particles are generally produced by an emulsion polymerization method, a suspension polymerization method, a precipitation polymerization method, an interfacial polymerization method, a mechanical pulverization method of synthetic resin pieces, an association method utilizing ζ potential, a coacervation method or the like. However, an emulsion polymerization method, a suspension polymerization method, an association method utilizing a ζ potential or the like is preferable.

The secondary particles constituting the above-mentioned associated particles, which are a preferable example of the present invention, are not in a mode that inhibits the present invention.
The form is not limited, but preferably the primary particles of the polymer and the colorant are ionic bond, hydrogen bond,
The particles are aggregated by a bonding force such as a metal bond or a weak acid-weak base bond.

The aggregated form of the associated particles is not particularly limited as long as the polymer particles and the colorant are aggregated. Generally, ζ is required to generate such associated particles.
An electric potential, a coacervate, an association method such as interfacial polymerization, a method of pulverizing after thermally fusing the interface, and the like can be used,
Among them, the association method is preferably used.

The average particle size of the primary particles of the polymer particles is preferably 0.01 to 10 μm, more preferably 0.01 to 8 μm, further preferably 0.01 to 5 μm, and particularly preferably 0.01 to 3 μm. The average particle size of the secondary particles is preferably 0.05 to 15 μm, more preferably 0.01 to 10 μm, further preferably 0.2 to 8 μm, particularly preferably 0.5 to 5 μm.

The average particle diameter (particle diameter of associated particles) of the toner of the present invention is 0.5 to 25 μm, preferably 1 to 15 μm,
The thickness is more preferably 1 to 13 μm, and particularly preferably 1 to 8 μm.

The styrenes include, for example,
Styrene, n-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-te
rt-Butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-distyrene Examples thereof include chlorostyrene and p-chloromethylstyrene.

Examples of the alkyl (meth) acrylate include methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, and acrylic. Lauryl acid, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, α-methyl chloroacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate,
N-butyl methacrylate, isobutyl methacrylate,
N-octyl methacrylate, dodecyl methacrylate,
Examples thereof include lauryl methacrylate, 2-ethylhexyl methacrylate, and stearyl methacrylate. Among them, those having 1 to 12 carbon atoms are preferable, and 3 to 8
More preferred is an aliphatic alcohol (meth) acrylic acid ester having 4 carbon atoms.

Examples of the above-mentioned comonomer having an acidic polar group include an α, β-ethylenically unsaturated compound having a carboxyl group and an α, β-ethylenically unsaturated compound having a sulfone group. Examples of the α, β ethylenically unsaturated compound having a carboxyl group include acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, maleic acid monobutyl ester, and maleic acid monooctyl. ester,
And metal salts thereof such as sodium and zinc.

Examples of the α, β ethylenically unsaturated compound having a sulfone group include sulfonated ethylene, Na salt thereof, allylsulfosuccinic acid, octyl allylsulfosuccinate, and Na salt thereof.

Examples of the comonomer having a basic polar group include, for example, an amine group or a quaternary ammonium group having 1 to 12 carbon atoms, preferably 2 to 8 carbon atoms, and particularly preferably 2 (carbon atoms). ) Acrylic acid ester, (meth) acrylic acid amide or (meth) acrylic acid amide mono- or di-substituted with an alkyl group having 1 to 18 carbon atoms on N, and also having N as a ring member Mention may be made of vinyl compounds substituted with a heterocyclic group and N, N-diallyl-alkylamines or quaternary ammonium salts thereof. Among them, aliphatic alcohol (meth) acrylic acid ester having an amine group or a quaternary ammonium group is preferably used as a basic comonomer.

Examples of the (meth) acrylic acid ester of an aliphatic alcohol having an amine group or a quaternary ammonium group are, for example, dimethylaminoethyl acrylate.
, Dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, quaternary ammonium salts thereof, 3-dimethylaminophenyl acrylate, 2-hydroxy-3-methacryloxypropyl A trimethylammonium salt etc. can be mentioned.

The above (meth) acrylic acid amide or, optionally on N, an alkyl group having 1 to 18 carbon atoms, which is mono or di-
Examples of the substituted (meth) acrylic acid amide include acrylamide, N-butylacrylamide, N, N-dibutylacrylamide, piperidylacrylamide, methacrylamide, N-butylmethacrylamide, N, N-dimethylacrylamide and N-octadecyl. Examples thereof include acrylamide.

Examples of the vinyl compound substituted with a heterocyclic group having N as a ring member include vinyl pyridine, vinyl pyrrolidone, vinyl N-methylpyridinium chloride and vinyl N-ethyl. Pyridinium chloride etc. can be mentioned. Examples of the N, N-diallyl-alkylamine include N, N-diallylmethylammonium chloride, N, N-diallylethylammonium chloride and the like.

The polar polymer preferably has a glass transition point of −90 to 100 ° C., and −30 to 80 ° C.
C. is more preferable, and −10 to 70 ° C. is further preferable. If the glass transition temperature exceeds 100 ° C, the low-temperature fixability tends to be poor, and if it is less than -90 ° C, the powder fluidity of the toner tends to decrease, which is not preferred.

Further, examples of the polymer having a polar group include polyester resin and epoxy resin. As the polyester resin, for example, a polycondensation polymer of a polyvalent alcohol such as etherified bisphenol A or glycols and a dibasic acid such as terephthalic acid, fumaric acid or maleic acid, Alternatively, three-dimensional or higher order copolymers including trimellitic acid, pyromellitic acid and the like can be mentioned, and their molecular weight is preferably about 2000 to 200,000. Examples of the epoxy resin include a resin obtained by reacting epichlorohydrin with bisphenol A or polyvalent alcohol or a modified product thereof, and the softening point thereof is preferably 90 to 200 ° C.

The degree of polymerization of the above-mentioned polymer is not particularly limited, but is generally 2000 to 4000 in terms of number average degree of polymerization.
00 is preferable, 5000 to 200000 is more preferable, and further 8000
~ 100,000 is preferred. The weight average polymerization degree is 3000
〜800000 is preferable, and 10,000〜400,000 is more preferable.

Considering the stability of the polymer particles as particles, the polar group has an acid value of 2 to 50 and an amine value of 1
It is preferably -15. On the other hand, the colorant has a coloring property such that it can be added to an electrostatic charge image developer to impart a color required as an electrostatic charge image developer, and is a magnetic substance such as magnetite or a charged substance such as nigrosine. Any material other than a colorant such as magnetic property or charge controllability such as a control material may be used.

Examples of the colorant include inorganic pigments, organic pigments, and organic dyes. Inorganic pigments or organic pigments are preferably used, and one or more kinds of pigments and / or one or more kinds of pigments are used. It is also possible to use a combination of the above dyes. As the inorganic pigment,
Examples thereof include metal powder pigments, metal oxide pigments, carbon pigments, sulfide pigments, chromate pigments, and ferrocyanide salt pigments.

Examples of the metal powder pigments include zinc powder, iron powder and copper powder. Examples of the metal oxide pigments include magnetite, ferrite, red iron oxide, titanium oxide, zinc white, silica, chromium oxide, ultramarine, cobalt bull, cerulean bull, milanel violet, and trilead tetraoxide. Can be mentioned.

Examples of the above-mentioned carbon-based pigments include carbon black, thermatomic carbon, and furnace black. Examples of the sulfide-based pigments include zinc sulfide, cadmium red, selenium red, mercury sulfide, and cadmium yellow. Examples of the chromate pigments include molybdenum red, barium yellow, strontium yellow, and chrome yellow. Examples of the ferrocyanide compound-based pigments include mirolible.

Examples of the organic pigments include azo pigments, acid dye pigments and basic dye pigments, mordant dye pigments, phthalocyanine pigments, quinacdrine pigments and dioxane pigments. Examples of the azo pigments include benzidine yellow, benzidine orange, permanent red 4R, pyrazolone red, lisole red, and brilliant scarlet.
G, Bon Maroon light, etc. can be mentioned.

Examples of the acidic dye-based pigments and the basic dye-based pigments include Orange II, Acid Orange R,
A dye obtained by precipitating a dye such as oxine, quinoline yellow, tartrazine yellow, acid green, peacock blue, and alkaline blue with a precipitating agent, or a low dye.
Examples thereof include those obtained by precipitating a dye such as damine, magenta, macalite green, methyl violet and Victoria blue with tannic acid, tartar, PTA, PMA, PTMA and the like.

Examples of the mordant dye-based pigment include metal salts of hydroxyanthraquinones and alizarin mer.
Examples include dark lakes and the like. Examples of the phthalocyanine-based pigment include phthalocyanine blue and sulfonated copper phthalocyanine. The above quinacridone pigment and dioxane pigment,
Examples thereof include quinacridone red, quinacridone violet, and carbazol-dioxane violet.

Other organic pigments include, for example, organic fluorescent pigments, aniline black, nigrosine dye, aniline dye and the like. Further, the toner of the present invention is
If necessary, a charge control agent, a magnetic substance, a fluidizing agent, and a release agent can be added. As the charge control agent, a nigrosine-based electron-donating dye for plus, other, metal salt of naphthenic acid or higher fatty acid, alkoxylated amine, quaternary ammonium salt, alkylamide, chelate
, A pigment, a fluorine treatment activator, and the like. In addition, an electron-accepting organic complex for negative use, other,
Examples thereof include chlorinated paraffin, chlorinated polyester, acid group excess polyester, and sulfonylamine of copper phthalocyanine.

Examples of the fluidizing agent include fine powders of hydrophobic silica, titanium oxide, aluminum oxide and the like. Such a fluidizing agent is preferably added in an amount of 0.01 to 5 parts by weight with respect to 100 parts by weight of toner, 0.1
-1 part by weight is more preferred. Further, as the release agent,
For example, stearic acid Cd, Ba, Ni, Co, St, Cu, Mg,
Ca salt, Zn, Mn, Fe, Co, Cu, Pb, Mg salt of oleic acid, Zn, Co, Cu, Mg, Si, Ca salt of palmitic acid, linoleic acid
Zn, Co, Ca salts, Zn, Cd salts of ricinoleic acid, Caprylic acid
There are metal salts of higher fatty acids such as Pb salts and Pb salts of caproic acid, natural and synthetic paraffins and fatty acid esters or partial saponification products thereof, alkylenebis fatty acid amides, etc., and one or two kinds of these compounds. An appropriate combination of the above is used.

[0046]

Example 1 Preparation of Polymer Containing Acidic Polar Group (1) Styrene Monomer (ST) 82 parts Butyl Acrylate Monomer (BA) 18 parts Acrylic Acid 5 parts or more Water 100 parts Nonionic emulsifier (Emulgen 950 ) 1 part Anionic emulsifier (Neogen R) 1.5 parts was added to an aqueous mixture, and potassium peroxide was used to polymerize for 8 hours at 70 ° C under stirring to give an acidic polar group-containing resin emulsion (1) having a solid content of 50%. Obtained.

Preparation of toner (2) Acid polar group-containing resin emulsion (1) 184 parts Chromium dye (Bontron E-82) 1 part Carbon black (Regal 330R) 7 parts Water 307 parts The above mixture Approximately 30 ° C with dispersion and stirring with a slasher
Held for 2 hours. Then, with further stirring, bring the temperature to 85 ° C for 3
Held for hours.

During this time, the resin particles and
It was confirmed that the Bonblack complex grows to 1.2 Mμm secondary particles and further associates with them to form associated particles, which are toner particles of about 6 μm. The liquid dispersion obtained by cooling was subjected to Buchner filtration, washed with water, and dried under vacuum at 50 ° C. for 10 hours.

The toner thus obtained had an S value of 119.2 and a V value of 5.
It was 75. To 100 parts by weight of the obtained toner, silica (Aerosil R-972 manufactured by Nippon Aerosil Co., Ltd.) was added as a fluidizing agent.
5 parts by weight were added and mixed to obtain a test developer. When this toner was placed in a commercially available copying machine (Mita DC2055) and copying was performed, an image with high density and little fog and very good resolution was obtained. Table 1 shows the physical properties of the obtained toner and the result of the copying test.

[0050]

Example 2 The same procedure as in Example 1 was carried out except that St 85 parts, BA 15 parts, and AA 5 parts were used to obtain a test toner of about 5 μm. Further, Table 1 shows the results of the image processing and the copy test performed in the same manner as in Example 1.

The procedure of Example 1 was repeated except that the amount of St used was 88 parts, 2-ethylhexyl acrylate (2EHA) was 12 parts, and methacrylic acid (MAA) was 6 parts to obtain a test toner of about 7 μm. Further, Table 1 shows the results of the image processing and the copy test performed in the same manner as in Example 1.

In the same manner as in Example 1, the same operation as in Example 1 was carried out except that it was held for 8 hours instead of being held for 3 hours to obtain a test toner of about 7 μm. Further, Table 1 shows the results of the image processing and the copy test performed in the same manner as in Example 1.

The procedure of Example 1 was repeated, except that the temperature was maintained at 65 ° C. instead of at 85 ° C. during the reaction for forming associated particles to obtain a test toner of about 5 μm. Further Example 1
Table 1 shows the results of the image processing and the copying test carried out by the same method as above.

[0054]

Comparative Example 1 100 parts of resin powder obtained by suspension polymerization, washing and drying of 82 parts of styrene monomer and 18 parts of butyl acrylate monomer, and 7 parts of carbon black used in Examples 1 to 7 Chromium dye E-82 (1 part) was kneaded with a Banbury mixer and pulverized to about 9 μm using a jet mill. Table 1 shows the results of image processing and copying test of this powder by the same method as in Example 1.

[0055]

Comparative Example 2 The powder obtained in Comparative Example 1 was spheroidized by a hybridizer (manufactured by Nara Machinery Co., Ltd.), and then subjected to image processing and copying test in exactly the same manner as in Example 1. Is shown in Table 1.

Evaluation method (b) Method for measuring S value and V value The toner thus obtained was subjected to image processing with LUZEX 3U manufactured by Nikon Corporation to determine the S value. At this time, the number of measurements was 10,000, and the average value was taken as the S value. An electron micrograph (10000 times) of the toner particles was applied to the same processing machine as above to determine the V value, and the average value of 1000 measurements was taken as the V value.

(B) Change in particle size In the copy test of Examples and Comparative Examples, the life test (100
The number distribution of toner in the initial developer (% by number of particles of 5 μm or less) was compared with the number distribution of toner in the developer after the life test. When it is 130% or more, scattering occurs and the charge amount becomes unstable, and it is poor, and when it is 110% or less, it is good.

(C) Softening point measuring method 1 g of a resin sample was weighed and measured in a Shimadzu Flow Tester CFT500 under the conditions of nozzle 1 × 10 mm, load 30 kg, and heating rate 3 ° C./min. The temperature at the midpoint of the distance from the end to the end was defined as the softening point.

(D) Glass transition point (Tg) A differential scanning calorimeter, Shimadzu DSC-30, was measured under a H ₂ gas atmosphere at a temperature rising rate of 10 ° C./min, and the shoulder value was taken as Tg. (E) Duplicate image density evaluation method Using a Macbeth reflection densitometer RD-914, the image density (solid black portion of Electrophotographic Society Test Chart NO1-R1975) was measured.

(F) Fog Whiteness is measured using a color difference meter (CR-200) manufactured by Minolta Co., Ltd. Whiteness of natural paper before copying K ₀ = 100-[(100-L) ² + a ² + b ² ] ^1/2 Whiteness of non-image area after copying K = 100-[(( 100-L) ² + a ² + b ² ] ^{1/2 The} fog is calculated by the following formula. Fog (%) = K / K ₀ × 100 The lower the fog, the better, 0.5 or less is good, and 1.0 or more is bad. ..

(G) Reproduction Electrophotographic Society test chart NO1-R1975 was copied and the resolution pattern 8.0 points was magnified 100 times with an optical microscope.
It was visually judged as follows.

5. Fine lines are reproduced and there is almost no fogging between fine lines. 4. Fine lines are reproduced, but some fog is observed between fine lines. Lots of mist 2. Reproducibility of fine lines is large, and fogging between fine lines is also frequent 1. Fine lines are not reproduced, but one line. Higher resolution is better, resolution of 4 or less is good, and 3 or less is bad. Can be judged.

(H) Visual Evaluation In the copy life test (10,000 sheets), the state during life was observed and evaluated. The observation items were (1) cleaning failure, (2) cleaning blade curl, (3) scattering, (4) generation of black / white spots, and (5) fixing offset.

[0064]

[Table 1]

[0065]

The present invention relates to a toner for developing an electrostatic charge image in electrophotography, electrostatic recording, electrostatic printing and the like. The toner obtained by the present invention is a toner having excellent image density and resolution, and excellent physical properties with little fogging and scattering.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Kensuke Okuda 3-16-15 Owada, Chigasaki City, Kanagawa Prefecture (72) Masatoshi Maruyama 13-6 Yuhigaoka, Hiratsuka City, Kanagawa Prefecture

Claims (3)

[Claims] 1. A toner for developing an electrostatic charge image comprising a polymer, a colorant, and an optional charge control agent, wherein the toner particles have a shape factor S value of 100.5 to 160.0. Toner for development. 2. An association particle of secondary particles comprising primary particles and a colorant particle of a polymer having an acidic polar group or a basic polar group and an optional charge control agent, wherein the S value is
The toner for developing an electrostatic charge image according to claim 1, wherein the toner has a thickness of 100.5 to 160.0. 3. An associative particle of secondary particles comprising primary particles and a colorant particle of a polymer having an acidic polar group or a basic polar group, and an optional charge control agent, each of which has an average particle diameter. = Rm and the minimum value of the radius of curvature of each particle surface = rn are 1.01 ≤ V ≤ 320 V = rm / rn 2.5 ≤ rm ≤ 16 0.05 ≤ rn <rm, and substantially rm = rn The toner for developing an electrostatic charge image according to claim 1 or 2, wherein no particles are present and the volume average particle diameter is 2.5 to 12 µm.